f4880aada2
Fix libpcap issue #893: check for invalid IPv4 addresses. This fixes errors such as: tcpdump -i lagg0 net 999.999.999.999 This was originally discovered on a Red Hat 7.7 server and verified to also be a bug on FreeBSD. Obtained from: https://github.com/the-tcpdump-group/libpcap/commit/ \ 07070918d5e81a515315b395f334e52589fe0fb Fixed by: https://github.com/guyharris MFC after: 2 weeks
9999 lines
257 KiB
C
9999 lines
257 KiB
C
/*#define CHASE_CHAIN*/
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/*
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* Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that: (1) source code distributions
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* retain the above copyright notice and this paragraph in its entirety, (2)
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* distributions including binary code include the above copyright notice and
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* this paragraph in its entirety in the documentation or other materials
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* provided with the distribution, and (3) all advertising materials mentioning
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* features or use of this software display the following acknowledgement:
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* ``This product includes software developed by the University of California,
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* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
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* the University nor the names of its contributors may be used to endorse
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* or promote products derived from this software without specific prior
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* written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*/
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif
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#include <pcap-types.h>
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#ifdef _WIN32
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#include <ws2tcpip.h>
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#else
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#include <sys/socket.h>
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#ifdef __NetBSD__
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#include <sys/param.h>
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#endif
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#endif /* _WIN32 */
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#include <stdlib.h>
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#include <string.h>
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#include <memory.h>
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#include <setjmp.h>
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#include <stdarg.h>
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#ifdef MSDOS
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#include "pcap-dos.h"
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#endif
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#include "pcap-int.h"
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#include "extract.h"
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#include "ethertype.h"
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#include "nlpid.h"
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#include "llc.h"
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#include "gencode.h"
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#include "ieee80211.h"
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#include "atmuni31.h"
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#include "sunatmpos.h"
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#include "ppp.h"
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#include "pcap/sll.h"
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#include "pcap/ipnet.h"
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#include "arcnet.h"
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#include "grammar.h"
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#include "scanner.h"
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#if defined(linux) && defined(PF_PACKET) && defined(SO_ATTACH_FILTER)
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#include <linux/types.h>
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#include <linux/if_packet.h>
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#include <linux/filter.h>
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#endif
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#ifdef HAVE_NET_PFVAR_H
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#include <sys/socket.h>
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#include <net/if.h>
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#include <net/pfvar.h>
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#include <net/if_pflog.h>
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#endif
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#ifndef offsetof
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#define offsetof(s, e) ((size_t)&((s *)0)->e)
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#endif
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#ifdef _WIN32
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#ifdef INET6
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#if defined(__MINGW32__) && defined(DEFINE_ADDITIONAL_IPV6_STUFF)
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/* IPv6 address */
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struct in6_addr
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{
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union
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{
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uint8_t u6_addr8[16];
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uint16_t u6_addr16[8];
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uint32_t u6_addr32[4];
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} in6_u;
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#define s6_addr in6_u.u6_addr8
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#define s6_addr16 in6_u.u6_addr16
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#define s6_addr32 in6_u.u6_addr32
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#define s6_addr64 in6_u.u6_addr64
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};
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typedef unsigned short sa_family_t;
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#define __SOCKADDR_COMMON(sa_prefix) \
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sa_family_t sa_prefix##family
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/* Ditto, for IPv6. */
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struct sockaddr_in6
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{
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__SOCKADDR_COMMON (sin6_);
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uint16_t sin6_port; /* Transport layer port # */
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uint32_t sin6_flowinfo; /* IPv6 flow information */
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struct in6_addr sin6_addr; /* IPv6 address */
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};
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#ifndef EAI_ADDRFAMILY
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struct addrinfo {
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int ai_flags; /* AI_PASSIVE, AI_CANONNAME */
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int ai_family; /* PF_xxx */
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int ai_socktype; /* SOCK_xxx */
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int ai_protocol; /* 0 or IPPROTO_xxx for IPv4 and IPv6 */
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size_t ai_addrlen; /* length of ai_addr */
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char *ai_canonname; /* canonical name for hostname */
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struct sockaddr *ai_addr; /* binary address */
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struct addrinfo *ai_next; /* next structure in linked list */
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};
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#endif /* EAI_ADDRFAMILY */
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#endif /* defined(__MINGW32__) && defined(DEFINE_ADDITIONAL_IPV6_STUFF) */
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#endif /* INET6 */
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#else /* _WIN32 */
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#include <netdb.h> /* for "struct addrinfo" */
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#endif /* _WIN32 */
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#include <pcap/namedb.h>
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#include "nametoaddr.h"
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#define ETHERMTU 1500
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#ifndef ETHERTYPE_TEB
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#define ETHERTYPE_TEB 0x6558
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#endif
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#ifndef IPPROTO_HOPOPTS
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#define IPPROTO_HOPOPTS 0
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#endif
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#ifndef IPPROTO_ROUTING
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#define IPPROTO_ROUTING 43
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#endif
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#ifndef IPPROTO_FRAGMENT
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#define IPPROTO_FRAGMENT 44
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#endif
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#ifndef IPPROTO_DSTOPTS
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#define IPPROTO_DSTOPTS 60
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#endif
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#ifndef IPPROTO_SCTP
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#define IPPROTO_SCTP 132
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#endif
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#define GENEVE_PORT 6081
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#ifdef HAVE_OS_PROTO_H
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#include "os-proto.h"
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#endif
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#define JMP(c) ((c)|BPF_JMP|BPF_K)
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/*
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* "Push" the current value of the link-layer header type and link-layer
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* header offset onto a "stack", and set a new value. (It's not a
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* full-blown stack; we keep only the top two items.)
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*/
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#define PUSH_LINKHDR(cs, new_linktype, new_is_variable, new_constant_part, new_reg) \
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{ \
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(cs)->prevlinktype = (cs)->linktype; \
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(cs)->off_prevlinkhdr = (cs)->off_linkhdr; \
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(cs)->linktype = (new_linktype); \
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(cs)->off_linkhdr.is_variable = (new_is_variable); \
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(cs)->off_linkhdr.constant_part = (new_constant_part); \
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(cs)->off_linkhdr.reg = (new_reg); \
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(cs)->is_geneve = 0; \
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}
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/*
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* Offset "not set" value.
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*/
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#define OFFSET_NOT_SET 0xffffffffU
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/*
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* Absolute offsets, which are offsets from the beginning of the raw
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* packet data, are, in the general case, the sum of a variable value
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* and a constant value; the variable value may be absent, in which
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* case the offset is only the constant value, and the constant value
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* may be zero, in which case the offset is only the variable value.
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*
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* bpf_abs_offset is a structure containing all that information:
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*
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* is_variable is 1 if there's a variable part.
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*
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* constant_part is the constant part of the value, possibly zero;
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*
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* if is_variable is 1, reg is the register number for a register
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* containing the variable value if the register has been assigned,
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* and -1 otherwise.
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*/
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typedef struct {
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int is_variable;
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u_int constant_part;
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int reg;
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} bpf_abs_offset;
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/*
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* Value passed to gen_load_a() to indicate what the offset argument
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* is relative to the beginning of.
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*/
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enum e_offrel {
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OR_PACKET, /* full packet data */
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OR_LINKHDR, /* link-layer header */
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OR_PREVLINKHDR, /* previous link-layer header */
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OR_LLC, /* 802.2 LLC header */
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OR_PREVMPLSHDR, /* previous MPLS header */
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OR_LINKTYPE, /* link-layer type */
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OR_LINKPL, /* link-layer payload */
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OR_LINKPL_NOSNAP, /* link-layer payload, with no SNAP header at the link layer */
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OR_TRAN_IPV4, /* transport-layer header, with IPv4 network layer */
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OR_TRAN_IPV6 /* transport-layer header, with IPv6 network layer */
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};
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/*
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* We divy out chunks of memory rather than call malloc each time so
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* we don't have to worry about leaking memory. It's probably
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* not a big deal if all this memory was wasted but if this ever
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* goes into a library that would probably not be a good idea.
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*
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* XXX - this *is* in a library....
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*/
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#define NCHUNKS 16
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#define CHUNK0SIZE 1024
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struct chunk {
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size_t n_left;
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void *m;
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};
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/* Code generator state */
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struct _compiler_state {
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jmp_buf top_ctx;
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pcap_t *bpf_pcap;
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struct icode ic;
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int snaplen;
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int linktype;
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int prevlinktype;
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int outermostlinktype;
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bpf_u_int32 netmask;
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int no_optimize;
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/* Hack for handling VLAN and MPLS stacks. */
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u_int label_stack_depth;
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u_int vlan_stack_depth;
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/* XXX */
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u_int pcap_fddipad;
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/*
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* As errors are handled by a longjmp, anything allocated must
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* be freed in the longjmp handler, so it must be reachable
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* from that handler.
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*
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* One thing that's allocated is the result of pcap_nametoaddrinfo();
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* it must be freed with freeaddrinfo(). This variable points to
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* any addrinfo structure that would need to be freed.
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*/
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struct addrinfo *ai;
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/*
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* Another thing that's allocated is the result of pcap_ether_aton();
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* it must be freed with free(). This variable points to any
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* address that would need to be freed.
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*/
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u_char *e;
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/*
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* Various code constructs need to know the layout of the packet.
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* These values give the necessary offsets from the beginning
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* of the packet data.
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*/
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/*
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* Absolute offset of the beginning of the link-layer header.
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*/
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bpf_abs_offset off_linkhdr;
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/*
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* If we're checking a link-layer header for a packet encapsulated
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* in another protocol layer, this is the equivalent information
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* for the previous layers' link-layer header from the beginning
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* of the raw packet data.
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*/
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bpf_abs_offset off_prevlinkhdr;
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/*
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* This is the equivalent information for the outermost layers'
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* link-layer header.
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*/
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bpf_abs_offset off_outermostlinkhdr;
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/*
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* Absolute offset of the beginning of the link-layer payload.
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*/
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bpf_abs_offset off_linkpl;
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/*
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* "off_linktype" is the offset to information in the link-layer
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* header giving the packet type. This is an absolute offset
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* from the beginning of the packet.
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*
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* For Ethernet, it's the offset of the Ethernet type field; this
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* means that it must have a value that skips VLAN tags.
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*
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* For link-layer types that always use 802.2 headers, it's the
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* offset of the LLC header; this means that it must have a value
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* that skips VLAN tags.
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*
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* For PPP, it's the offset of the PPP type field.
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*
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* For Cisco HDLC, it's the offset of the CHDLC type field.
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*
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* For BSD loopback, it's the offset of the AF_ value.
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*
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* For Linux cooked sockets, it's the offset of the type field.
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*
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* off_linktype.constant_part is set to OFFSET_NOT_SET for no
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* encapsulation, in which case, IP is assumed.
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*/
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bpf_abs_offset off_linktype;
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/*
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* TRUE if the link layer includes an ATM pseudo-header.
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*/
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int is_atm;
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/*
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* TRUE if "geneve" appeared in the filter; it causes us to
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* generate code that checks for a Geneve header and assume
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* that later filters apply to the encapsulated payload.
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*/
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int is_geneve;
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/*
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* TRUE if we need variable length part of VLAN offset
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*/
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int is_vlan_vloffset;
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/*
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* These are offsets for the ATM pseudo-header.
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*/
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u_int off_vpi;
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u_int off_vci;
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u_int off_proto;
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/*
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* These are offsets for the MTP2 fields.
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*/
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u_int off_li;
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u_int off_li_hsl;
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/*
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* These are offsets for the MTP3 fields.
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*/
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u_int off_sio;
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u_int off_opc;
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u_int off_dpc;
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u_int off_sls;
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/*
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* This is the offset of the first byte after the ATM pseudo_header,
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* or -1 if there is no ATM pseudo-header.
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*/
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u_int off_payload;
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/*
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* These are offsets to the beginning of the network-layer header.
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* They are relative to the beginning of the link-layer payload
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* (i.e., they don't include off_linkhdr.constant_part or
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* off_linkpl.constant_part).
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*
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* If the link layer never uses 802.2 LLC:
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*
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* "off_nl" and "off_nl_nosnap" are the same.
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*
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* If the link layer always uses 802.2 LLC:
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*
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* "off_nl" is the offset if there's a SNAP header following
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* the 802.2 header;
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*
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* "off_nl_nosnap" is the offset if there's no SNAP header.
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*
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* If the link layer is Ethernet:
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*
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* "off_nl" is the offset if the packet is an Ethernet II packet
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* (we assume no 802.3+802.2+SNAP);
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*
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* "off_nl_nosnap" is the offset if the packet is an 802.3 packet
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* with an 802.2 header following it.
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*/
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u_int off_nl;
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u_int off_nl_nosnap;
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/*
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* Here we handle simple allocation of the scratch registers.
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* If too many registers are alloc'd, the allocator punts.
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*/
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int regused[BPF_MEMWORDS];
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int curreg;
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/*
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* Memory chunks.
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*/
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struct chunk chunks[NCHUNKS];
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int cur_chunk;
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};
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/*
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* For use by routines outside this file.
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*/
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/* VARARGS */
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void
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bpf_set_error(compiler_state_t *cstate, const char *fmt, ...)
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{
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va_list ap;
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va_start(ap, fmt);
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(void)pcap_vsnprintf(cstate->bpf_pcap->errbuf, PCAP_ERRBUF_SIZE,
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fmt, ap);
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va_end(ap);
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}
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/*
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* For use *ONLY* in routines in this file.
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*/
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static void PCAP_NORETURN bpf_error(compiler_state_t *, const char *, ...)
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PCAP_PRINTFLIKE(2, 3);
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/* VARARGS */
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static void PCAP_NORETURN
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bpf_error(compiler_state_t *cstate, const char *fmt, ...)
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{
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va_list ap;
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va_start(ap, fmt);
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(void)pcap_vsnprintf(cstate->bpf_pcap->errbuf, PCAP_ERRBUF_SIZE,
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fmt, ap);
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va_end(ap);
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longjmp(cstate->top_ctx, 1);
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/*NOTREACHED*/
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}
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static int init_linktype(compiler_state_t *, pcap_t *);
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static void init_regs(compiler_state_t *);
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static int alloc_reg(compiler_state_t *);
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static void free_reg(compiler_state_t *, int);
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static void initchunks(compiler_state_t *cstate);
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static void *newchunk_nolongjmp(compiler_state_t *cstate, size_t);
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static void *newchunk(compiler_state_t *cstate, size_t);
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static void freechunks(compiler_state_t *cstate);
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static inline struct block *new_block(compiler_state_t *cstate, int);
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static inline struct slist *new_stmt(compiler_state_t *cstate, int);
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static struct block *gen_retblk(compiler_state_t *cstate, int);
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static inline void syntax(compiler_state_t *cstate);
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static void backpatch(struct block *, struct block *);
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static void merge(struct block *, struct block *);
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static struct block *gen_cmp(compiler_state_t *, enum e_offrel, u_int,
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u_int, bpf_int32);
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static struct block *gen_cmp_gt(compiler_state_t *, enum e_offrel, u_int,
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u_int, bpf_int32);
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static struct block *gen_cmp_ge(compiler_state_t *, enum e_offrel, u_int,
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u_int, bpf_int32);
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static struct block *gen_cmp_lt(compiler_state_t *, enum e_offrel, u_int,
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u_int, bpf_int32);
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static struct block *gen_cmp_le(compiler_state_t *, enum e_offrel, u_int,
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u_int, bpf_int32);
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static struct block *gen_mcmp(compiler_state_t *, enum e_offrel, u_int,
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u_int, bpf_int32, bpf_u_int32);
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static struct block *gen_bcmp(compiler_state_t *, enum e_offrel, u_int,
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u_int, const u_char *);
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static struct block *gen_ncmp(compiler_state_t *, enum e_offrel, bpf_u_int32,
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bpf_u_int32, bpf_u_int32, bpf_u_int32, int, bpf_int32);
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static struct slist *gen_load_absoffsetrel(compiler_state_t *, bpf_abs_offset *,
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u_int, u_int);
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static struct slist *gen_load_a(compiler_state_t *, enum e_offrel, u_int,
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u_int);
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static struct slist *gen_loadx_iphdrlen(compiler_state_t *);
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static struct block *gen_uncond(compiler_state_t *, int);
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static inline struct block *gen_true(compiler_state_t *);
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static inline struct block *gen_false(compiler_state_t *);
|
|
static struct block *gen_ether_linktype(compiler_state_t *, int);
|
|
static struct block *gen_ipnet_linktype(compiler_state_t *, int);
|
|
static struct block *gen_linux_sll_linktype(compiler_state_t *, int);
|
|
static struct slist *gen_load_prism_llprefixlen(compiler_state_t *);
|
|
static struct slist *gen_load_avs_llprefixlen(compiler_state_t *);
|
|
static struct slist *gen_load_radiotap_llprefixlen(compiler_state_t *);
|
|
static struct slist *gen_load_ppi_llprefixlen(compiler_state_t *);
|
|
static void insert_compute_vloffsets(compiler_state_t *, struct block *);
|
|
static struct slist *gen_abs_offset_varpart(compiler_state_t *,
|
|
bpf_abs_offset *);
|
|
static int ethertype_to_ppptype(int);
|
|
static struct block *gen_linktype(compiler_state_t *, int);
|
|
static struct block *gen_snap(compiler_state_t *, bpf_u_int32, bpf_u_int32);
|
|
static struct block *gen_llc_linktype(compiler_state_t *, int);
|
|
static struct block *gen_hostop(compiler_state_t *, bpf_u_int32, bpf_u_int32,
|
|
int, int, u_int, u_int);
|
|
#ifdef INET6
|
|
static struct block *gen_hostop6(compiler_state_t *, struct in6_addr *,
|
|
struct in6_addr *, int, int, u_int, u_int);
|
|
#endif
|
|
static struct block *gen_ahostop(compiler_state_t *, const u_char *, int);
|
|
static struct block *gen_ehostop(compiler_state_t *, const u_char *, int);
|
|
static struct block *gen_fhostop(compiler_state_t *, const u_char *, int);
|
|
static struct block *gen_thostop(compiler_state_t *, const u_char *, int);
|
|
static struct block *gen_wlanhostop(compiler_state_t *, const u_char *, int);
|
|
static struct block *gen_ipfchostop(compiler_state_t *, const u_char *, int);
|
|
static struct block *gen_dnhostop(compiler_state_t *, bpf_u_int32, int);
|
|
static struct block *gen_mpls_linktype(compiler_state_t *, int);
|
|
static struct block *gen_host(compiler_state_t *, bpf_u_int32, bpf_u_int32,
|
|
int, int, int);
|
|
#ifdef INET6
|
|
static struct block *gen_host6(compiler_state_t *, struct in6_addr *,
|
|
struct in6_addr *, int, int, int);
|
|
#endif
|
|
#ifndef INET6
|
|
static struct block *gen_gateway(compiler_state_t *, const u_char *,
|
|
struct addrinfo *, int, int);
|
|
#endif
|
|
static struct block *gen_ipfrag(compiler_state_t *);
|
|
static struct block *gen_portatom(compiler_state_t *, int, bpf_int32);
|
|
static struct block *gen_portrangeatom(compiler_state_t *, int, bpf_int32,
|
|
bpf_int32);
|
|
static struct block *gen_portatom6(compiler_state_t *, int, bpf_int32);
|
|
static struct block *gen_portrangeatom6(compiler_state_t *, int, bpf_int32,
|
|
bpf_int32);
|
|
struct block *gen_portop(compiler_state_t *, int, int, int);
|
|
static struct block *gen_port(compiler_state_t *, int, int, int);
|
|
struct block *gen_portrangeop(compiler_state_t *, int, int, int, int);
|
|
static struct block *gen_portrange(compiler_state_t *, int, int, int, int);
|
|
struct block *gen_portop6(compiler_state_t *, int, int, int);
|
|
static struct block *gen_port6(compiler_state_t *, int, int, int);
|
|
struct block *gen_portrangeop6(compiler_state_t *, int, int, int, int);
|
|
static struct block *gen_portrange6(compiler_state_t *, int, int, int, int);
|
|
static int lookup_proto(compiler_state_t *, const char *, int);
|
|
static struct block *gen_protochain(compiler_state_t *, int, int, int);
|
|
static struct block *gen_proto(compiler_state_t *, int, int, int);
|
|
static struct slist *xfer_to_x(compiler_state_t *, struct arth *);
|
|
static struct slist *xfer_to_a(compiler_state_t *, struct arth *);
|
|
static struct block *gen_mac_multicast(compiler_state_t *, int);
|
|
static struct block *gen_len(compiler_state_t *, int, int);
|
|
static struct block *gen_check_802_11_data_frame(compiler_state_t *);
|
|
static struct block *gen_geneve_ll_check(compiler_state_t *cstate);
|
|
|
|
static struct block *gen_ppi_dlt_check(compiler_state_t *);
|
|
static struct block *gen_atmfield_code_internal(compiler_state_t *, int,
|
|
bpf_int32, bpf_u_int32, int);
|
|
static struct block *gen_atmtype_llc(compiler_state_t *);
|
|
static struct block *gen_msg_abbrev(compiler_state_t *, int type);
|
|
|
|
static void
|
|
initchunks(compiler_state_t *cstate)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < NCHUNKS; i++) {
|
|
cstate->chunks[i].n_left = 0;
|
|
cstate->chunks[i].m = NULL;
|
|
}
|
|
cstate->cur_chunk = 0;
|
|
}
|
|
|
|
static void *
|
|
newchunk_nolongjmp(compiler_state_t *cstate, size_t n)
|
|
{
|
|
struct chunk *cp;
|
|
int k;
|
|
size_t size;
|
|
|
|
#ifndef __NetBSD__
|
|
/* XXX Round up to nearest long. */
|
|
n = (n + sizeof(long) - 1) & ~(sizeof(long) - 1);
|
|
#else
|
|
/* XXX Round up to structure boundary. */
|
|
n = ALIGN(n);
|
|
#endif
|
|
|
|
cp = &cstate->chunks[cstate->cur_chunk];
|
|
if (n > cp->n_left) {
|
|
++cp;
|
|
k = ++cstate->cur_chunk;
|
|
if (k >= NCHUNKS) {
|
|
bpf_set_error(cstate, "out of memory");
|
|
return (NULL);
|
|
}
|
|
size = CHUNK0SIZE << k;
|
|
cp->m = (void *)malloc(size);
|
|
if (cp->m == NULL) {
|
|
bpf_set_error(cstate, "out of memory");
|
|
return (NULL);
|
|
}
|
|
memset((char *)cp->m, 0, size);
|
|
cp->n_left = size;
|
|
if (n > size) {
|
|
bpf_set_error(cstate, "out of memory");
|
|
return (NULL);
|
|
}
|
|
}
|
|
cp->n_left -= n;
|
|
return (void *)((char *)cp->m + cp->n_left);
|
|
}
|
|
|
|
static void *
|
|
newchunk(compiler_state_t *cstate, size_t n)
|
|
{
|
|
void *p;
|
|
|
|
p = newchunk_nolongjmp(cstate, n);
|
|
if (p == NULL) {
|
|
longjmp(cstate->top_ctx, 1);
|
|
/*NOTREACHED*/
|
|
}
|
|
return (p);
|
|
}
|
|
|
|
static void
|
|
freechunks(compiler_state_t *cstate)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < NCHUNKS; ++i)
|
|
if (cstate->chunks[i].m != NULL)
|
|
free(cstate->chunks[i].m);
|
|
}
|
|
|
|
/*
|
|
* A strdup whose allocations are freed after code generation is over.
|
|
* This is used by the lexical analyzer, so it can't longjmp; it just
|
|
* returns NULL on an allocation error, and the callers must check
|
|
* for it.
|
|
*/
|
|
char *
|
|
sdup(compiler_state_t *cstate, const char *s)
|
|
{
|
|
size_t n = strlen(s) + 1;
|
|
char *cp = newchunk_nolongjmp(cstate, n);
|
|
|
|
if (cp == NULL)
|
|
return (NULL);
|
|
pcap_strlcpy(cp, s, n);
|
|
return (cp);
|
|
}
|
|
|
|
static inline struct block *
|
|
new_block(compiler_state_t *cstate, int code)
|
|
{
|
|
struct block *p;
|
|
|
|
p = (struct block *)newchunk(cstate, sizeof(*p));
|
|
p->s.code = code;
|
|
p->head = p;
|
|
|
|
return p;
|
|
}
|
|
|
|
static inline struct slist *
|
|
new_stmt(compiler_state_t *cstate, int code)
|
|
{
|
|
struct slist *p;
|
|
|
|
p = (struct slist *)newchunk(cstate, sizeof(*p));
|
|
p->s.code = code;
|
|
|
|
return p;
|
|
}
|
|
|
|
static struct block *
|
|
gen_retblk(compiler_state_t *cstate, int v)
|
|
{
|
|
struct block *b = new_block(cstate, BPF_RET|BPF_K);
|
|
|
|
b->s.k = v;
|
|
return b;
|
|
}
|
|
|
|
static inline PCAP_NORETURN_DEF void
|
|
syntax(compiler_state_t *cstate)
|
|
{
|
|
bpf_error(cstate, "syntax error in filter expression");
|
|
}
|
|
|
|
int
|
|
pcap_compile(pcap_t *p, struct bpf_program *program,
|
|
const char *buf, int optimize, bpf_u_int32 mask)
|
|
{
|
|
#ifdef _WIN32
|
|
static int done = 0;
|
|
#endif
|
|
compiler_state_t cstate;
|
|
const char * volatile xbuf = buf;
|
|
yyscan_t scanner = NULL;
|
|
volatile YY_BUFFER_STATE in_buffer = NULL;
|
|
u_int len;
|
|
int rc;
|
|
|
|
/*
|
|
* If this pcap_t hasn't been activated, it doesn't have a
|
|
* link-layer type, so we can't use it.
|
|
*/
|
|
if (!p->activated) {
|
|
pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
"not-yet-activated pcap_t passed to pcap_compile");
|
|
return (-1);
|
|
}
|
|
|
|
#ifdef _WIN32
|
|
if (!done)
|
|
pcap_wsockinit();
|
|
done = 1;
|
|
#endif
|
|
|
|
#ifdef ENABLE_REMOTE
|
|
/*
|
|
* If the device on which we're capturing need to be notified
|
|
* that a new filter is being compiled, do so.
|
|
*
|
|
* This allows them to save a copy of it, in case, for example,
|
|
* they're implementing a form of remote packet capture, and
|
|
* want the remote machine to filter out the packets in which
|
|
* it's sending the packets it's captured.
|
|
*
|
|
* XXX - the fact that we happen to be compiling a filter
|
|
* doesn't necessarily mean we'll be installing it as the
|
|
* filter for this pcap_t; we might be running it from userland
|
|
* on captured packets to do packet classification. We really
|
|
* need a better way of handling this, but this is all that
|
|
* the WinPcap remote capture code did.
|
|
*/
|
|
if (p->save_current_filter_op != NULL)
|
|
(p->save_current_filter_op)(p, buf);
|
|
#endif
|
|
|
|
initchunks(&cstate);
|
|
cstate.no_optimize = 0;
|
|
#ifdef INET6
|
|
cstate.ai = NULL;
|
|
#endif
|
|
cstate.e = NULL;
|
|
cstate.ic.root = NULL;
|
|
cstate.ic.cur_mark = 0;
|
|
cstate.bpf_pcap = p;
|
|
init_regs(&cstate);
|
|
|
|
cstate.netmask = mask;
|
|
|
|
cstate.snaplen = pcap_snapshot(p);
|
|
if (cstate.snaplen == 0) {
|
|
pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
"snaplen of 0 rejects all packets");
|
|
rc = -1;
|
|
goto quit;
|
|
}
|
|
|
|
if (pcap_lex_init(&scanner) != 0)
|
|
pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
errno, "can't initialize scanner");
|
|
in_buffer = pcap__scan_string(xbuf ? xbuf : "", scanner);
|
|
|
|
/*
|
|
* Associate the compiler state with the lexical analyzer
|
|
* state.
|
|
*/
|
|
pcap_set_extra(&cstate, scanner);
|
|
|
|
if (init_linktype(&cstate, p) == -1) {
|
|
rc = -1;
|
|
goto quit;
|
|
}
|
|
if (pcap_parse(scanner, &cstate) != 0) {
|
|
#ifdef INET6
|
|
if (cstate.ai != NULL)
|
|
freeaddrinfo(cstate.ai);
|
|
#endif
|
|
if (cstate.e != NULL)
|
|
free(cstate.e);
|
|
rc = -1;
|
|
goto quit;
|
|
}
|
|
|
|
if (cstate.ic.root == NULL) {
|
|
/*
|
|
* Catch errors reported by gen_retblk().
|
|
*/
|
|
if (setjmp(cstate.top_ctx)) {
|
|
rc = -1;
|
|
goto quit;
|
|
}
|
|
cstate.ic.root = gen_retblk(&cstate, cstate.snaplen);
|
|
}
|
|
|
|
if (optimize && !cstate.no_optimize) {
|
|
if (bpf_optimize(&cstate.ic, p->errbuf) == -1) {
|
|
/* Failure */
|
|
rc = -1;
|
|
goto quit;
|
|
}
|
|
if (cstate.ic.root == NULL ||
|
|
(cstate.ic.root->s.code == (BPF_RET|BPF_K) && cstate.ic.root->s.k == 0)) {
|
|
(void)pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
"expression rejects all packets");
|
|
rc = -1;
|
|
goto quit;
|
|
}
|
|
}
|
|
program->bf_insns = icode_to_fcode(&cstate.ic,
|
|
cstate.ic.root, &len, p->errbuf);
|
|
if (program->bf_insns == NULL) {
|
|
/* Failure */
|
|
rc = -1;
|
|
goto quit;
|
|
}
|
|
program->bf_len = len;
|
|
|
|
rc = 0; /* We're all okay */
|
|
|
|
quit:
|
|
/*
|
|
* Clean up everything for the lexical analyzer.
|
|
*/
|
|
if (in_buffer != NULL)
|
|
pcap__delete_buffer(in_buffer, scanner);
|
|
if (scanner != NULL)
|
|
pcap_lex_destroy(scanner);
|
|
|
|
/*
|
|
* Clean up our own allocated memory.
|
|
*/
|
|
freechunks(&cstate);
|
|
|
|
return (rc);
|
|
}
|
|
|
|
/*
|
|
* entry point for using the compiler with no pcap open
|
|
* pass in all the stuff that is needed explicitly instead.
|
|
*/
|
|
int
|
|
pcap_compile_nopcap(int snaplen_arg, int linktype_arg,
|
|
struct bpf_program *program,
|
|
const char *buf, int optimize, bpf_u_int32 mask)
|
|
{
|
|
pcap_t *p;
|
|
int ret;
|
|
|
|
p = pcap_open_dead(linktype_arg, snaplen_arg);
|
|
if (p == NULL)
|
|
return (-1);
|
|
ret = pcap_compile(p, program, buf, optimize, mask);
|
|
pcap_close(p);
|
|
return (ret);
|
|
}
|
|
|
|
/*
|
|
* Clean up a "struct bpf_program" by freeing all the memory allocated
|
|
* in it.
|
|
*/
|
|
void
|
|
pcap_freecode(struct bpf_program *program)
|
|
{
|
|
program->bf_len = 0;
|
|
if (program->bf_insns != NULL) {
|
|
free((char *)program->bf_insns);
|
|
program->bf_insns = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Backpatch the blocks in 'list' to 'target'. The 'sense' field indicates
|
|
* which of the jt and jf fields has been resolved and which is a pointer
|
|
* back to another unresolved block (or nil). At least one of the fields
|
|
* in each block is already resolved.
|
|
*/
|
|
static void
|
|
backpatch(struct block *list, struct block *target)
|
|
{
|
|
struct block *next;
|
|
|
|
while (list) {
|
|
if (!list->sense) {
|
|
next = JT(list);
|
|
JT(list) = target;
|
|
} else {
|
|
next = JF(list);
|
|
JF(list) = target;
|
|
}
|
|
list = next;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Merge the lists in b0 and b1, using the 'sense' field to indicate
|
|
* which of jt and jf is the link.
|
|
*/
|
|
static void
|
|
merge(struct block *b0, struct block *b1)
|
|
{
|
|
register struct block **p = &b0;
|
|
|
|
/* Find end of list. */
|
|
while (*p)
|
|
p = !((*p)->sense) ? &JT(*p) : &JF(*p);
|
|
|
|
/* Concatenate the lists. */
|
|
*p = b1;
|
|
}
|
|
|
|
int
|
|
finish_parse(compiler_state_t *cstate, struct block *p)
|
|
{
|
|
struct block *ppi_dlt_check;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return -1
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (-1);
|
|
|
|
/*
|
|
* Insert before the statements of the first (root) block any
|
|
* statements needed to load the lengths of any variable-length
|
|
* headers into registers.
|
|
*
|
|
* XXX - a fancier strategy would be to insert those before the
|
|
* statements of all blocks that use those lengths and that
|
|
* have no predecessors that use them, so that we only compute
|
|
* the lengths if we need them. There might be even better
|
|
* approaches than that.
|
|
*
|
|
* However, those strategies would be more complicated, and
|
|
* as we don't generate code to compute a length if the
|
|
* program has no tests that use the length, and as most
|
|
* tests will probably use those lengths, we would just
|
|
* postpone computing the lengths so that it's not done
|
|
* for tests that fail early, and it's not clear that's
|
|
* worth the effort.
|
|
*/
|
|
insert_compute_vloffsets(cstate, p->head);
|
|
|
|
/*
|
|
* For DLT_PPI captures, generate a check of the per-packet
|
|
* DLT value to make sure it's DLT_IEEE802_11.
|
|
*
|
|
* XXX - TurboCap cards use DLT_PPI for Ethernet.
|
|
* Can we just define some DLT_ETHERNET_WITH_PHDR pseudo-header
|
|
* with appropriate Ethernet information and use that rather
|
|
* than using something such as DLT_PPI where you don't know
|
|
* the link-layer header type until runtime, which, in the
|
|
* general case, would force us to generate both Ethernet *and*
|
|
* 802.11 code (*and* anything else for which PPI is used)
|
|
* and choose between them early in the BPF program?
|
|
*/
|
|
ppi_dlt_check = gen_ppi_dlt_check(cstate);
|
|
if (ppi_dlt_check != NULL)
|
|
gen_and(ppi_dlt_check, p);
|
|
|
|
backpatch(p, gen_retblk(cstate, cstate->snaplen));
|
|
p->sense = !p->sense;
|
|
backpatch(p, gen_retblk(cstate, 0));
|
|
cstate->ic.root = p->head;
|
|
return (0);
|
|
}
|
|
|
|
void
|
|
gen_and(struct block *b0, struct block *b1)
|
|
{
|
|
backpatch(b0, b1->head);
|
|
b0->sense = !b0->sense;
|
|
b1->sense = !b1->sense;
|
|
merge(b1, b0);
|
|
b1->sense = !b1->sense;
|
|
b1->head = b0->head;
|
|
}
|
|
|
|
void
|
|
gen_or(struct block *b0, struct block *b1)
|
|
{
|
|
b0->sense = !b0->sense;
|
|
backpatch(b0, b1->head);
|
|
b0->sense = !b0->sense;
|
|
merge(b1, b0);
|
|
b1->head = b0->head;
|
|
}
|
|
|
|
void
|
|
gen_not(struct block *b)
|
|
{
|
|
b->sense = !b->sense;
|
|
}
|
|
|
|
static struct block *
|
|
gen_cmp(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
|
|
u_int size, bpf_int32 v)
|
|
{
|
|
return gen_ncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JEQ, 0, v);
|
|
}
|
|
|
|
static struct block *
|
|
gen_cmp_gt(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
|
|
u_int size, bpf_int32 v)
|
|
{
|
|
return gen_ncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JGT, 0, v);
|
|
}
|
|
|
|
static struct block *
|
|
gen_cmp_ge(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
|
|
u_int size, bpf_int32 v)
|
|
{
|
|
return gen_ncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JGE, 0, v);
|
|
}
|
|
|
|
static struct block *
|
|
gen_cmp_lt(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
|
|
u_int size, bpf_int32 v)
|
|
{
|
|
return gen_ncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JGE, 1, v);
|
|
}
|
|
|
|
static struct block *
|
|
gen_cmp_le(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
|
|
u_int size, bpf_int32 v)
|
|
{
|
|
return gen_ncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JGT, 1, v);
|
|
}
|
|
|
|
static struct block *
|
|
gen_mcmp(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
|
|
u_int size, bpf_int32 v, bpf_u_int32 mask)
|
|
{
|
|
return gen_ncmp(cstate, offrel, offset, size, mask, BPF_JEQ, 0, v);
|
|
}
|
|
|
|
static struct block *
|
|
gen_bcmp(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
|
|
u_int size, const u_char *v)
|
|
{
|
|
register struct block *b, *tmp;
|
|
|
|
/*
|
|
* XXX - the actual *instructions* do unsigned comparisons on
|
|
* most platforms, and the load instructions don't do sign
|
|
* extension, so gen_cmp() should really take an unsigned
|
|
* value argument.
|
|
*
|
|
* As the load instructons also don't do sign-extension, we
|
|
* fetch the values from the byte array as unsigned. We don't
|
|
* want to use the signed versions of the extract calls.
|
|
*/
|
|
b = NULL;
|
|
while (size >= 4) {
|
|
register const u_char *p = &v[size - 4];
|
|
|
|
tmp = gen_cmp(cstate, offrel, offset + size - 4, BPF_W,
|
|
(bpf_int32)EXTRACT_32BITS(p));
|
|
if (b != NULL)
|
|
gen_and(b, tmp);
|
|
b = tmp;
|
|
size -= 4;
|
|
}
|
|
while (size >= 2) {
|
|
register const u_char *p = &v[size - 2];
|
|
|
|
tmp = gen_cmp(cstate, offrel, offset + size - 2, BPF_H,
|
|
(bpf_int32)EXTRACT_16BITS(p));
|
|
if (b != NULL)
|
|
gen_and(b, tmp);
|
|
b = tmp;
|
|
size -= 2;
|
|
}
|
|
if (size > 0) {
|
|
tmp = gen_cmp(cstate, offrel, offset, BPF_B, (bpf_int32)v[0]);
|
|
if (b != NULL)
|
|
gen_and(b, tmp);
|
|
b = tmp;
|
|
}
|
|
return b;
|
|
}
|
|
|
|
/*
|
|
* AND the field of size "size" at offset "offset" relative to the header
|
|
* specified by "offrel" with "mask", and compare it with the value "v"
|
|
* with the test specified by "jtype"; if "reverse" is true, the test
|
|
* should test the opposite of "jtype".
|
|
*/
|
|
static struct block *
|
|
gen_ncmp(compiler_state_t *cstate, enum e_offrel offrel, bpf_u_int32 offset,
|
|
bpf_u_int32 size, bpf_u_int32 mask, bpf_u_int32 jtype, int reverse,
|
|
bpf_int32 v)
|
|
{
|
|
struct slist *s, *s2;
|
|
struct block *b;
|
|
|
|
s = gen_load_a(cstate, offrel, offset, size);
|
|
|
|
if (mask != 0xffffffff) {
|
|
s2 = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_K);
|
|
s2->s.k = mask;
|
|
sappend(s, s2);
|
|
}
|
|
|
|
b = new_block(cstate, JMP(jtype));
|
|
b->stmts = s;
|
|
b->s.k = v;
|
|
if (reverse && (jtype == BPF_JGT || jtype == BPF_JGE))
|
|
gen_not(b);
|
|
return b;
|
|
}
|
|
|
|
static int
|
|
init_linktype(compiler_state_t *cstate, pcap_t *p)
|
|
{
|
|
cstate->pcap_fddipad = p->fddipad;
|
|
|
|
/*
|
|
* We start out with only one link-layer header.
|
|
*/
|
|
cstate->outermostlinktype = pcap_datalink(p);
|
|
cstate->off_outermostlinkhdr.constant_part = 0;
|
|
cstate->off_outermostlinkhdr.is_variable = 0;
|
|
cstate->off_outermostlinkhdr.reg = -1;
|
|
|
|
cstate->prevlinktype = cstate->outermostlinktype;
|
|
cstate->off_prevlinkhdr.constant_part = 0;
|
|
cstate->off_prevlinkhdr.is_variable = 0;
|
|
cstate->off_prevlinkhdr.reg = -1;
|
|
|
|
cstate->linktype = cstate->outermostlinktype;
|
|
cstate->off_linkhdr.constant_part = 0;
|
|
cstate->off_linkhdr.is_variable = 0;
|
|
cstate->off_linkhdr.reg = -1;
|
|
|
|
/*
|
|
* XXX
|
|
*/
|
|
cstate->off_linkpl.constant_part = 0;
|
|
cstate->off_linkpl.is_variable = 0;
|
|
cstate->off_linkpl.reg = -1;
|
|
|
|
cstate->off_linktype.constant_part = 0;
|
|
cstate->off_linktype.is_variable = 0;
|
|
cstate->off_linktype.reg = -1;
|
|
|
|
/*
|
|
* Assume it's not raw ATM with a pseudo-header, for now.
|
|
*/
|
|
cstate->is_atm = 0;
|
|
cstate->off_vpi = OFFSET_NOT_SET;
|
|
cstate->off_vci = OFFSET_NOT_SET;
|
|
cstate->off_proto = OFFSET_NOT_SET;
|
|
cstate->off_payload = OFFSET_NOT_SET;
|
|
|
|
/*
|
|
* And not Geneve.
|
|
*/
|
|
cstate->is_geneve = 0;
|
|
|
|
/*
|
|
* No variable length VLAN offset by default
|
|
*/
|
|
cstate->is_vlan_vloffset = 0;
|
|
|
|
/*
|
|
* And assume we're not doing SS7.
|
|
*/
|
|
cstate->off_li = OFFSET_NOT_SET;
|
|
cstate->off_li_hsl = OFFSET_NOT_SET;
|
|
cstate->off_sio = OFFSET_NOT_SET;
|
|
cstate->off_opc = OFFSET_NOT_SET;
|
|
cstate->off_dpc = OFFSET_NOT_SET;
|
|
cstate->off_sls = OFFSET_NOT_SET;
|
|
|
|
cstate->label_stack_depth = 0;
|
|
cstate->vlan_stack_depth = 0;
|
|
|
|
switch (cstate->linktype) {
|
|
|
|
case DLT_ARCNET:
|
|
cstate->off_linktype.constant_part = 2;
|
|
cstate->off_linkpl.constant_part = 6;
|
|
cstate->off_nl = 0; /* XXX in reality, variable! */
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_ARCNET_LINUX:
|
|
cstate->off_linktype.constant_part = 4;
|
|
cstate->off_linkpl.constant_part = 8;
|
|
cstate->off_nl = 0; /* XXX in reality, variable! */
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_EN10MB:
|
|
cstate->off_linktype.constant_part = 12;
|
|
cstate->off_linkpl.constant_part = 14; /* Ethernet header length */
|
|
cstate->off_nl = 0; /* Ethernet II */
|
|
cstate->off_nl_nosnap = 3; /* 802.3+802.2 */
|
|
break;
|
|
|
|
case DLT_SLIP:
|
|
/*
|
|
* SLIP doesn't have a link level type. The 16 byte
|
|
* header is hacked into our SLIP driver.
|
|
*/
|
|
cstate->off_linktype.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_linkpl.constant_part = 16;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_SLIP_BSDOS:
|
|
/* XXX this may be the same as the DLT_PPP_BSDOS case */
|
|
cstate->off_linktype.constant_part = OFFSET_NOT_SET;
|
|
/* XXX end */
|
|
cstate->off_linkpl.constant_part = 24;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_NULL:
|
|
case DLT_LOOP:
|
|
cstate->off_linktype.constant_part = 0;
|
|
cstate->off_linkpl.constant_part = 4;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_ENC:
|
|
cstate->off_linktype.constant_part = 0;
|
|
cstate->off_linkpl.constant_part = 12;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_PPP:
|
|
case DLT_PPP_PPPD:
|
|
case DLT_C_HDLC: /* BSD/OS Cisco HDLC */
|
|
case DLT_PPP_SERIAL: /* NetBSD sync/async serial PPP */
|
|
cstate->off_linktype.constant_part = 2; /* skip HDLC-like framing */
|
|
cstate->off_linkpl.constant_part = 4; /* skip HDLC-like framing and protocol field */
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_PPP_ETHER:
|
|
/*
|
|
* This does no include the Ethernet header, and
|
|
* only covers session state.
|
|
*/
|
|
cstate->off_linktype.constant_part = 6;
|
|
cstate->off_linkpl.constant_part = 8;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_PPP_BSDOS:
|
|
cstate->off_linktype.constant_part = 5;
|
|
cstate->off_linkpl.constant_part = 24;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_FDDI:
|
|
/*
|
|
* FDDI doesn't really have a link-level type field.
|
|
* We set "off_linktype" to the offset of the LLC header.
|
|
*
|
|
* To check for Ethernet types, we assume that SSAP = SNAP
|
|
* is being used and pick out the encapsulated Ethernet type.
|
|
* XXX - should we generate code to check for SNAP?
|
|
*/
|
|
cstate->off_linktype.constant_part = 13;
|
|
cstate->off_linktype.constant_part += cstate->pcap_fddipad;
|
|
cstate->off_linkpl.constant_part = 13; /* FDDI MAC header length */
|
|
cstate->off_linkpl.constant_part += cstate->pcap_fddipad;
|
|
cstate->off_nl = 8; /* 802.2+SNAP */
|
|
cstate->off_nl_nosnap = 3; /* 802.2 */
|
|
break;
|
|
|
|
case DLT_IEEE802:
|
|
/*
|
|
* Token Ring doesn't really have a link-level type field.
|
|
* We set "off_linktype" to the offset of the LLC header.
|
|
*
|
|
* To check for Ethernet types, we assume that SSAP = SNAP
|
|
* is being used and pick out the encapsulated Ethernet type.
|
|
* XXX - should we generate code to check for SNAP?
|
|
*
|
|
* XXX - the header is actually variable-length.
|
|
* Some various Linux patched versions gave 38
|
|
* as "off_linktype" and 40 as "off_nl"; however,
|
|
* if a token ring packet has *no* routing
|
|
* information, i.e. is not source-routed, the correct
|
|
* values are 20 and 22, as they are in the vanilla code.
|
|
*
|
|
* A packet is source-routed iff the uppermost bit
|
|
* of the first byte of the source address, at an
|
|
* offset of 8, has the uppermost bit set. If the
|
|
* packet is source-routed, the total number of bytes
|
|
* of routing information is 2 plus bits 0x1F00 of
|
|
* the 16-bit value at an offset of 14 (shifted right
|
|
* 8 - figure out which byte that is).
|
|
*/
|
|
cstate->off_linktype.constant_part = 14;
|
|
cstate->off_linkpl.constant_part = 14; /* Token Ring MAC header length */
|
|
cstate->off_nl = 8; /* 802.2+SNAP */
|
|
cstate->off_nl_nosnap = 3; /* 802.2 */
|
|
break;
|
|
|
|
case DLT_PRISM_HEADER:
|
|
case DLT_IEEE802_11_RADIO_AVS:
|
|
case DLT_IEEE802_11_RADIO:
|
|
cstate->off_linkhdr.is_variable = 1;
|
|
/* Fall through, 802.11 doesn't have a variable link
|
|
* prefix but is otherwise the same. */
|
|
/* FALLTHROUGH */
|
|
|
|
case DLT_IEEE802_11:
|
|
/*
|
|
* 802.11 doesn't really have a link-level type field.
|
|
* We set "off_linktype.constant_part" to the offset of
|
|
* the LLC header.
|
|
*
|
|
* To check for Ethernet types, we assume that SSAP = SNAP
|
|
* is being used and pick out the encapsulated Ethernet type.
|
|
* XXX - should we generate code to check for SNAP?
|
|
*
|
|
* We also handle variable-length radio headers here.
|
|
* The Prism header is in theory variable-length, but in
|
|
* practice it's always 144 bytes long. However, some
|
|
* drivers on Linux use ARPHRD_IEEE80211_PRISM, but
|
|
* sometimes or always supply an AVS header, so we
|
|
* have to check whether the radio header is a Prism
|
|
* header or an AVS header, so, in practice, it's
|
|
* variable-length.
|
|
*/
|
|
cstate->off_linktype.constant_part = 24;
|
|
cstate->off_linkpl.constant_part = 0; /* link-layer header is variable-length */
|
|
cstate->off_linkpl.is_variable = 1;
|
|
cstate->off_nl = 8; /* 802.2+SNAP */
|
|
cstate->off_nl_nosnap = 3; /* 802.2 */
|
|
break;
|
|
|
|
case DLT_PPI:
|
|
/*
|
|
* At the moment we treat PPI the same way that we treat
|
|
* normal Radiotap encoded packets. The difference is in
|
|
* the function that generates the code at the beginning
|
|
* to compute the header length. Since this code generator
|
|
* of PPI supports bare 802.11 encapsulation only (i.e.
|
|
* the encapsulated DLT should be DLT_IEEE802_11) we
|
|
* generate code to check for this too.
|
|
*/
|
|
cstate->off_linktype.constant_part = 24;
|
|
cstate->off_linkpl.constant_part = 0; /* link-layer header is variable-length */
|
|
cstate->off_linkpl.is_variable = 1;
|
|
cstate->off_linkhdr.is_variable = 1;
|
|
cstate->off_nl = 8; /* 802.2+SNAP */
|
|
cstate->off_nl_nosnap = 3; /* 802.2 */
|
|
break;
|
|
|
|
case DLT_ATM_RFC1483:
|
|
case DLT_ATM_CLIP: /* Linux ATM defines this */
|
|
/*
|
|
* assume routed, non-ISO PDUs
|
|
* (i.e., LLC = 0xAA-AA-03, OUT = 0x00-00-00)
|
|
*
|
|
* XXX - what about ISO PDUs, e.g. CLNP, ISIS, ESIS,
|
|
* or PPP with the PPP NLPID (e.g., PPPoA)? The
|
|
* latter would presumably be treated the way PPPoE
|
|
* should be, so you can do "pppoe and udp port 2049"
|
|
* or "pppoa and tcp port 80" and have it check for
|
|
* PPPo{A,E} and a PPP protocol of IP and....
|
|
*/
|
|
cstate->off_linktype.constant_part = 0;
|
|
cstate->off_linkpl.constant_part = 0; /* packet begins with LLC header */
|
|
cstate->off_nl = 8; /* 802.2+SNAP */
|
|
cstate->off_nl_nosnap = 3; /* 802.2 */
|
|
break;
|
|
|
|
case DLT_SUNATM:
|
|
/*
|
|
* Full Frontal ATM; you get AALn PDUs with an ATM
|
|
* pseudo-header.
|
|
*/
|
|
cstate->is_atm = 1;
|
|
cstate->off_vpi = SUNATM_VPI_POS;
|
|
cstate->off_vci = SUNATM_VCI_POS;
|
|
cstate->off_proto = PROTO_POS;
|
|
cstate->off_payload = SUNATM_PKT_BEGIN_POS;
|
|
cstate->off_linktype.constant_part = cstate->off_payload;
|
|
cstate->off_linkpl.constant_part = cstate->off_payload; /* if LLC-encapsulated */
|
|
cstate->off_nl = 8; /* 802.2+SNAP */
|
|
cstate->off_nl_nosnap = 3; /* 802.2 */
|
|
break;
|
|
|
|
case DLT_RAW:
|
|
case DLT_IPV4:
|
|
case DLT_IPV6:
|
|
cstate->off_linktype.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_linkpl.constant_part = 0;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_LINUX_SLL: /* fake header for Linux cooked socket v1 */
|
|
cstate->off_linktype.constant_part = 14;
|
|
cstate->off_linkpl.constant_part = 16;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_LINUX_SLL2: /* fake header for Linux cooked socket v2 */
|
|
cstate->off_linktype.constant_part = 0;
|
|
cstate->off_linkpl.constant_part = 20;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_LTALK:
|
|
/*
|
|
* LocalTalk does have a 1-byte type field in the LLAP header,
|
|
* but really it just indicates whether there is a "short" or
|
|
* "long" DDP packet following.
|
|
*/
|
|
cstate->off_linktype.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_linkpl.constant_part = 0;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_IP_OVER_FC:
|
|
/*
|
|
* RFC 2625 IP-over-Fibre-Channel doesn't really have a
|
|
* link-level type field. We set "off_linktype" to the
|
|
* offset of the LLC header.
|
|
*
|
|
* To check for Ethernet types, we assume that SSAP = SNAP
|
|
* is being used and pick out the encapsulated Ethernet type.
|
|
* XXX - should we generate code to check for SNAP? RFC
|
|
* 2625 says SNAP should be used.
|
|
*/
|
|
cstate->off_linktype.constant_part = 16;
|
|
cstate->off_linkpl.constant_part = 16;
|
|
cstate->off_nl = 8; /* 802.2+SNAP */
|
|
cstate->off_nl_nosnap = 3; /* 802.2 */
|
|
break;
|
|
|
|
case DLT_FRELAY:
|
|
/*
|
|
* XXX - we should set this to handle SNAP-encapsulated
|
|
* frames (NLPID of 0x80).
|
|
*/
|
|
cstate->off_linktype.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_linkpl.constant_part = 0;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
break;
|
|
|
|
/*
|
|
* the only BPF-interesting FRF.16 frames are non-control frames;
|
|
* Frame Relay has a variable length link-layer
|
|
* so lets start with offset 4 for now and increments later on (FIXME);
|
|
*/
|
|
case DLT_MFR:
|
|
cstate->off_linktype.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_linkpl.constant_part = 0;
|
|
cstate->off_nl = 4;
|
|
cstate->off_nl_nosnap = 0; /* XXX - for now -> no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_APPLE_IP_OVER_IEEE1394:
|
|
cstate->off_linktype.constant_part = 16;
|
|
cstate->off_linkpl.constant_part = 18;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_SYMANTEC_FIREWALL:
|
|
cstate->off_linktype.constant_part = 6;
|
|
cstate->off_linkpl.constant_part = 44;
|
|
cstate->off_nl = 0; /* Ethernet II */
|
|
cstate->off_nl_nosnap = 0; /* XXX - what does it do with 802.3 packets? */
|
|
break;
|
|
|
|
#ifdef HAVE_NET_PFVAR_H
|
|
case DLT_PFLOG:
|
|
cstate->off_linktype.constant_part = 0;
|
|
cstate->off_linkpl.constant_part = PFLOG_HDRLEN;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
break;
|
|
#endif
|
|
|
|
case DLT_JUNIPER_MFR:
|
|
case DLT_JUNIPER_MLFR:
|
|
case DLT_JUNIPER_MLPPP:
|
|
case DLT_JUNIPER_PPP:
|
|
case DLT_JUNIPER_CHDLC:
|
|
case DLT_JUNIPER_FRELAY:
|
|
cstate->off_linktype.constant_part = 4;
|
|
cstate->off_linkpl.constant_part = 4;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_JUNIPER_ATM1:
|
|
cstate->off_linktype.constant_part = 4; /* in reality variable between 4-8 */
|
|
cstate->off_linkpl.constant_part = 4; /* in reality variable between 4-8 */
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 10;
|
|
break;
|
|
|
|
case DLT_JUNIPER_ATM2:
|
|
cstate->off_linktype.constant_part = 8; /* in reality variable between 8-12 */
|
|
cstate->off_linkpl.constant_part = 8; /* in reality variable between 8-12 */
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 10;
|
|
break;
|
|
|
|
/* frames captured on a Juniper PPPoE service PIC
|
|
* contain raw ethernet frames */
|
|
case DLT_JUNIPER_PPPOE:
|
|
case DLT_JUNIPER_ETHER:
|
|
cstate->off_linkpl.constant_part = 14;
|
|
cstate->off_linktype.constant_part = 16;
|
|
cstate->off_nl = 18; /* Ethernet II */
|
|
cstate->off_nl_nosnap = 21; /* 802.3+802.2 */
|
|
break;
|
|
|
|
case DLT_JUNIPER_PPPOE_ATM:
|
|
cstate->off_linktype.constant_part = 4;
|
|
cstate->off_linkpl.constant_part = 6;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_JUNIPER_GGSN:
|
|
cstate->off_linktype.constant_part = 6;
|
|
cstate->off_linkpl.constant_part = 12;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_JUNIPER_ES:
|
|
cstate->off_linktype.constant_part = 6;
|
|
cstate->off_linkpl.constant_part = OFFSET_NOT_SET; /* not really a network layer but raw IP addresses */
|
|
cstate->off_nl = OFFSET_NOT_SET; /* not really a network layer but raw IP addresses */
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_JUNIPER_MONITOR:
|
|
cstate->off_linktype.constant_part = 12;
|
|
cstate->off_linkpl.constant_part = 12;
|
|
cstate->off_nl = 0; /* raw IP/IP6 header */
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_BACNET_MS_TP:
|
|
cstate->off_linktype.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_nl = OFFSET_NOT_SET;
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET;
|
|
break;
|
|
|
|
case DLT_JUNIPER_SERVICES:
|
|
cstate->off_linktype.constant_part = 12;
|
|
cstate->off_linkpl.constant_part = OFFSET_NOT_SET; /* L3 proto location dep. on cookie type */
|
|
cstate->off_nl = OFFSET_NOT_SET; /* L3 proto location dep. on cookie type */
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_JUNIPER_VP:
|
|
cstate->off_linktype.constant_part = 18;
|
|
cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_nl = OFFSET_NOT_SET;
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET;
|
|
break;
|
|
|
|
case DLT_JUNIPER_ST:
|
|
cstate->off_linktype.constant_part = 18;
|
|
cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_nl = OFFSET_NOT_SET;
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET;
|
|
break;
|
|
|
|
case DLT_JUNIPER_ISM:
|
|
cstate->off_linktype.constant_part = 8;
|
|
cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_nl = OFFSET_NOT_SET;
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET;
|
|
break;
|
|
|
|
case DLT_JUNIPER_VS:
|
|
case DLT_JUNIPER_SRX_E2E:
|
|
case DLT_JUNIPER_FIBRECHANNEL:
|
|
case DLT_JUNIPER_ATM_CEMIC:
|
|
cstate->off_linktype.constant_part = 8;
|
|
cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_nl = OFFSET_NOT_SET;
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET;
|
|
break;
|
|
|
|
case DLT_MTP2:
|
|
cstate->off_li = 2;
|
|
cstate->off_li_hsl = 4;
|
|
cstate->off_sio = 3;
|
|
cstate->off_opc = 4;
|
|
cstate->off_dpc = 4;
|
|
cstate->off_sls = 7;
|
|
cstate->off_linktype.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_nl = OFFSET_NOT_SET;
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET;
|
|
break;
|
|
|
|
case DLT_MTP2_WITH_PHDR:
|
|
cstate->off_li = 6;
|
|
cstate->off_li_hsl = 8;
|
|
cstate->off_sio = 7;
|
|
cstate->off_opc = 8;
|
|
cstate->off_dpc = 8;
|
|
cstate->off_sls = 11;
|
|
cstate->off_linktype.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_nl = OFFSET_NOT_SET;
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET;
|
|
break;
|
|
|
|
case DLT_ERF:
|
|
cstate->off_li = 22;
|
|
cstate->off_li_hsl = 24;
|
|
cstate->off_sio = 23;
|
|
cstate->off_opc = 24;
|
|
cstate->off_dpc = 24;
|
|
cstate->off_sls = 27;
|
|
cstate->off_linktype.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_nl = OFFSET_NOT_SET;
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET;
|
|
break;
|
|
|
|
case DLT_PFSYNC:
|
|
cstate->off_linktype.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_linkpl.constant_part = 4;
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 0;
|
|
break;
|
|
|
|
case DLT_AX25_KISS:
|
|
/*
|
|
* Currently, only raw "link[N:M]" filtering is supported.
|
|
*/
|
|
cstate->off_linktype.constant_part = OFFSET_NOT_SET; /* variable, min 15, max 71 steps of 7 */
|
|
cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_nl = OFFSET_NOT_SET; /* variable, min 16, max 71 steps of 7 */
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET; /* no 802.2 LLC */
|
|
break;
|
|
|
|
case DLT_IPNET:
|
|
cstate->off_linktype.constant_part = 1;
|
|
cstate->off_linkpl.constant_part = 24; /* ipnet header length */
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET;
|
|
break;
|
|
|
|
case DLT_NETANALYZER:
|
|
cstate->off_linkhdr.constant_part = 4; /* Ethernet header is past 4-byte pseudo-header */
|
|
cstate->off_linktype.constant_part = cstate->off_linkhdr.constant_part + 12;
|
|
cstate->off_linkpl.constant_part = cstate->off_linkhdr.constant_part + 14; /* pseudo-header+Ethernet header length */
|
|
cstate->off_nl = 0; /* Ethernet II */
|
|
cstate->off_nl_nosnap = 3; /* 802.3+802.2 */
|
|
break;
|
|
|
|
case DLT_NETANALYZER_TRANSPARENT:
|
|
cstate->off_linkhdr.constant_part = 12; /* MAC header is past 4-byte pseudo-header, preamble, and SFD */
|
|
cstate->off_linktype.constant_part = cstate->off_linkhdr.constant_part + 12;
|
|
cstate->off_linkpl.constant_part = cstate->off_linkhdr.constant_part + 14; /* pseudo-header+preamble+SFD+Ethernet header length */
|
|
cstate->off_nl = 0; /* Ethernet II */
|
|
cstate->off_nl_nosnap = 3; /* 802.3+802.2 */
|
|
break;
|
|
|
|
default:
|
|
/*
|
|
* For values in the range in which we've assigned new
|
|
* DLT_ values, only raw "link[N:M]" filtering is supported.
|
|
*/
|
|
if (cstate->linktype >= DLT_MATCHING_MIN &&
|
|
cstate->linktype <= DLT_MATCHING_MAX) {
|
|
cstate->off_linktype.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_linkpl.constant_part = OFFSET_NOT_SET;
|
|
cstate->off_nl = OFFSET_NOT_SET;
|
|
cstate->off_nl_nosnap = OFFSET_NOT_SET;
|
|
} else {
|
|
bpf_set_error(cstate, "unknown data link type %d", cstate->linktype);
|
|
return (-1);
|
|
}
|
|
break;
|
|
}
|
|
|
|
cstate->off_outermostlinkhdr = cstate->off_prevlinkhdr = cstate->off_linkhdr;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Load a value relative to the specified absolute offset.
|
|
*/
|
|
static struct slist *
|
|
gen_load_absoffsetrel(compiler_state_t *cstate, bpf_abs_offset *abs_offset,
|
|
u_int offset, u_int size)
|
|
{
|
|
struct slist *s, *s2;
|
|
|
|
s = gen_abs_offset_varpart(cstate, abs_offset);
|
|
|
|
/*
|
|
* If "s" is non-null, it has code to arrange that the X register
|
|
* contains the variable part of the absolute offset, so we
|
|
* generate a load relative to that, with an offset of
|
|
* abs_offset->constant_part + offset.
|
|
*
|
|
* Otherwise, we can do an absolute load with an offset of
|
|
* abs_offset->constant_part + offset.
|
|
*/
|
|
if (s != NULL) {
|
|
/*
|
|
* "s" points to a list of statements that puts the
|
|
* variable part of the absolute offset into the X register.
|
|
* Do an indirect load, to use the X register as an offset.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_LD|BPF_IND|size);
|
|
s2->s.k = abs_offset->constant_part + offset;
|
|
sappend(s, s2);
|
|
} else {
|
|
/*
|
|
* There is no variable part of the absolute offset, so
|
|
* just do an absolute load.
|
|
*/
|
|
s = new_stmt(cstate, BPF_LD|BPF_ABS|size);
|
|
s->s.k = abs_offset->constant_part + offset;
|
|
}
|
|
return s;
|
|
}
|
|
|
|
/*
|
|
* Load a value relative to the beginning of the specified header.
|
|
*/
|
|
static struct slist *
|
|
gen_load_a(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
|
|
u_int size)
|
|
{
|
|
struct slist *s, *s2;
|
|
|
|
/*
|
|
* Squelch warnings from compilers that *don't* assume that
|
|
* offrel always has a valid enum value and therefore don't
|
|
* assume that we'll always go through one of the case arms.
|
|
*
|
|
* If we have a default case, compilers that *do* assume that
|
|
* will then complain about the default case code being
|
|
* unreachable.
|
|
*
|
|
* Damned if you do, damned if you don't.
|
|
*/
|
|
s = NULL;
|
|
|
|
switch (offrel) {
|
|
|
|
case OR_PACKET:
|
|
s = new_stmt(cstate, BPF_LD|BPF_ABS|size);
|
|
s->s.k = offset;
|
|
break;
|
|
|
|
case OR_LINKHDR:
|
|
s = gen_load_absoffsetrel(cstate, &cstate->off_linkhdr, offset, size);
|
|
break;
|
|
|
|
case OR_PREVLINKHDR:
|
|
s = gen_load_absoffsetrel(cstate, &cstate->off_prevlinkhdr, offset, size);
|
|
break;
|
|
|
|
case OR_LLC:
|
|
s = gen_load_absoffsetrel(cstate, &cstate->off_linkpl, offset, size);
|
|
break;
|
|
|
|
case OR_PREVMPLSHDR:
|
|
s = gen_load_absoffsetrel(cstate, &cstate->off_linkpl, cstate->off_nl - 4 + offset, size);
|
|
break;
|
|
|
|
case OR_LINKPL:
|
|
s = gen_load_absoffsetrel(cstate, &cstate->off_linkpl, cstate->off_nl + offset, size);
|
|
break;
|
|
|
|
case OR_LINKPL_NOSNAP:
|
|
s = gen_load_absoffsetrel(cstate, &cstate->off_linkpl, cstate->off_nl_nosnap + offset, size);
|
|
break;
|
|
|
|
case OR_LINKTYPE:
|
|
s = gen_load_absoffsetrel(cstate, &cstate->off_linktype, offset, size);
|
|
break;
|
|
|
|
case OR_TRAN_IPV4:
|
|
/*
|
|
* Load the X register with the length of the IPv4 header
|
|
* (plus the offset of the link-layer header, if it's
|
|
* preceded by a variable-length header such as a radio
|
|
* header), in bytes.
|
|
*/
|
|
s = gen_loadx_iphdrlen(cstate);
|
|
|
|
/*
|
|
* Load the item at {offset of the link-layer payload} +
|
|
* {offset, relative to the start of the link-layer
|
|
* paylod, of the IPv4 header} + {length of the IPv4 header} +
|
|
* {specified offset}.
|
|
*
|
|
* If the offset of the link-layer payload is variable,
|
|
* the variable part of that offset is included in the
|
|
* value in the X register, and we include the constant
|
|
* part in the offset of the load.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_LD|BPF_IND|size);
|
|
s2->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + offset;
|
|
sappend(s, s2);
|
|
break;
|
|
|
|
case OR_TRAN_IPV6:
|
|
s = gen_load_absoffsetrel(cstate, &cstate->off_linkpl, cstate->off_nl + 40 + offset, size);
|
|
break;
|
|
}
|
|
return s;
|
|
}
|
|
|
|
/*
|
|
* Generate code to load into the X register the sum of the length of
|
|
* the IPv4 header and the variable part of the offset of the link-layer
|
|
* payload.
|
|
*/
|
|
static struct slist *
|
|
gen_loadx_iphdrlen(compiler_state_t *cstate)
|
|
{
|
|
struct slist *s, *s2;
|
|
|
|
s = gen_abs_offset_varpart(cstate, &cstate->off_linkpl);
|
|
if (s != NULL) {
|
|
/*
|
|
* The offset of the link-layer payload has a variable
|
|
* part. "s" points to a list of statements that put
|
|
* the variable part of that offset into the X register.
|
|
*
|
|
* The 4*([k]&0xf) addressing mode can't be used, as we
|
|
* don't have a constant offset, so we have to load the
|
|
* value in question into the A register and add to it
|
|
* the value from the X register.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B);
|
|
s2->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
|
|
sappend(s, s2);
|
|
s2 = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_K);
|
|
s2->s.k = 0xf;
|
|
sappend(s, s2);
|
|
s2 = new_stmt(cstate, BPF_ALU|BPF_LSH|BPF_K);
|
|
s2->s.k = 2;
|
|
sappend(s, s2);
|
|
|
|
/*
|
|
* The A register now contains the length of the IP header.
|
|
* We need to add to it the variable part of the offset of
|
|
* the link-layer payload, which is still in the X
|
|
* register, and move the result into the X register.
|
|
*/
|
|
sappend(s, new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X));
|
|
sappend(s, new_stmt(cstate, BPF_MISC|BPF_TAX));
|
|
} else {
|
|
/*
|
|
* The offset of the link-layer payload is a constant,
|
|
* so no code was generated to load the (non-existent)
|
|
* variable part of that offset.
|
|
*
|
|
* This means we can use the 4*([k]&0xf) addressing
|
|
* mode. Load the length of the IPv4 header, which
|
|
* is at an offset of cstate->off_nl from the beginning of
|
|
* the link-layer payload, and thus at an offset of
|
|
* cstate->off_linkpl.constant_part + cstate->off_nl from the beginning
|
|
* of the raw packet data, using that addressing mode.
|
|
*/
|
|
s = new_stmt(cstate, BPF_LDX|BPF_MSH|BPF_B);
|
|
s->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
|
|
}
|
|
return s;
|
|
}
|
|
|
|
|
|
static struct block *
|
|
gen_uncond(compiler_state_t *cstate, int rsense)
|
|
{
|
|
struct block *b;
|
|
struct slist *s;
|
|
|
|
s = new_stmt(cstate, BPF_LD|BPF_IMM);
|
|
s->s.k = !rsense;
|
|
b = new_block(cstate, JMP(BPF_JEQ));
|
|
b->stmts = s;
|
|
|
|
return b;
|
|
}
|
|
|
|
static inline struct block *
|
|
gen_true(compiler_state_t *cstate)
|
|
{
|
|
return gen_uncond(cstate, 1);
|
|
}
|
|
|
|
static inline struct block *
|
|
gen_false(compiler_state_t *cstate)
|
|
{
|
|
return gen_uncond(cstate, 0);
|
|
}
|
|
|
|
/*
|
|
* Byte-swap a 32-bit number.
|
|
* ("htonl()" or "ntohl()" won't work - we want to byte-swap even on
|
|
* big-endian platforms.)
|
|
*/
|
|
#define SWAPLONG(y) \
|
|
((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
|
|
|
|
/*
|
|
* Generate code to match a particular packet type.
|
|
*
|
|
* "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
|
|
* value, if <= ETHERMTU. We use that to determine whether to
|
|
* match the type/length field or to check the type/length field for
|
|
* a value <= ETHERMTU to see whether it's a type field and then do
|
|
* the appropriate test.
|
|
*/
|
|
static struct block *
|
|
gen_ether_linktype(compiler_state_t *cstate, int proto)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
switch (proto) {
|
|
|
|
case LLCSAP_ISONS:
|
|
case LLCSAP_IP:
|
|
case LLCSAP_NETBEUI:
|
|
/*
|
|
* OSI protocols and NetBEUI always use 802.2 encapsulation,
|
|
* so we check the DSAP and SSAP.
|
|
*
|
|
* LLCSAP_IP checks for IP-over-802.2, rather
|
|
* than IP-over-Ethernet or IP-over-SNAP.
|
|
*
|
|
* XXX - should we check both the DSAP and the
|
|
* SSAP, like this, or should we check just the
|
|
* DSAP, as we do for other types <= ETHERMTU
|
|
* (i.e., other SAP values)?
|
|
*/
|
|
b0 = gen_cmp_gt(cstate, OR_LINKTYPE, 0, BPF_H, ETHERMTU);
|
|
gen_not(b0);
|
|
b1 = gen_cmp(cstate, OR_LLC, 0, BPF_H, (bpf_int32)
|
|
((proto << 8) | proto));
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case LLCSAP_IPX:
|
|
/*
|
|
* Check for;
|
|
*
|
|
* Ethernet_II frames, which are Ethernet
|
|
* frames with a frame type of ETHERTYPE_IPX;
|
|
*
|
|
* Ethernet_802.3 frames, which are 802.3
|
|
* frames (i.e., the type/length field is
|
|
* a length field, <= ETHERMTU, rather than
|
|
* a type field) with the first two bytes
|
|
* after the Ethernet/802.3 header being
|
|
* 0xFFFF;
|
|
*
|
|
* Ethernet_802.2 frames, which are 802.3
|
|
* frames with an 802.2 LLC header and
|
|
* with the IPX LSAP as the DSAP in the LLC
|
|
* header;
|
|
*
|
|
* Ethernet_SNAP frames, which are 802.3
|
|
* frames with an LLC header and a SNAP
|
|
* header and with an OUI of 0x000000
|
|
* (encapsulated Ethernet) and a protocol
|
|
* ID of ETHERTYPE_IPX in the SNAP header.
|
|
*
|
|
* XXX - should we generate the same code both
|
|
* for tests for LLCSAP_IPX and for ETHERTYPE_IPX?
|
|
*/
|
|
|
|
/*
|
|
* This generates code to check both for the
|
|
* IPX LSAP (Ethernet_802.2) and for Ethernet_802.3.
|
|
*/
|
|
b0 = gen_cmp(cstate, OR_LLC, 0, BPF_B, (bpf_int32)LLCSAP_IPX);
|
|
b1 = gen_cmp(cstate, OR_LLC, 0, BPF_H, (bpf_int32)0xFFFF);
|
|
gen_or(b0, b1);
|
|
|
|
/*
|
|
* Now we add code to check for SNAP frames with
|
|
* ETHERTYPE_IPX, i.e. Ethernet_SNAP.
|
|
*/
|
|
b0 = gen_snap(cstate, 0x000000, ETHERTYPE_IPX);
|
|
gen_or(b0, b1);
|
|
|
|
/*
|
|
* Now we generate code to check for 802.3
|
|
* frames in general.
|
|
*/
|
|
b0 = gen_cmp_gt(cstate, OR_LINKTYPE, 0, BPF_H, ETHERMTU);
|
|
gen_not(b0);
|
|
|
|
/*
|
|
* Now add the check for 802.3 frames before the
|
|
* check for Ethernet_802.2 and Ethernet_802.3,
|
|
* as those checks should only be done on 802.3
|
|
* frames, not on Ethernet frames.
|
|
*/
|
|
gen_and(b0, b1);
|
|
|
|
/*
|
|
* Now add the check for Ethernet_II frames, and
|
|
* do that before checking for the other frame
|
|
* types.
|
|
*/
|
|
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)ETHERTYPE_IPX);
|
|
gen_or(b0, b1);
|
|
return b1;
|
|
|
|
case ETHERTYPE_ATALK:
|
|
case ETHERTYPE_AARP:
|
|
/*
|
|
* EtherTalk (AppleTalk protocols on Ethernet link
|
|
* layer) may use 802.2 encapsulation.
|
|
*/
|
|
|
|
/*
|
|
* Check for 802.2 encapsulation (EtherTalk phase 2?);
|
|
* we check for an Ethernet type field less than
|
|
* 1500, which means it's an 802.3 length field.
|
|
*/
|
|
b0 = gen_cmp_gt(cstate, OR_LINKTYPE, 0, BPF_H, ETHERMTU);
|
|
gen_not(b0);
|
|
|
|
/*
|
|
* 802.2-encapsulated ETHERTYPE_ATALK packets are
|
|
* SNAP packets with an organization code of
|
|
* 0x080007 (Apple, for Appletalk) and a protocol
|
|
* type of ETHERTYPE_ATALK (Appletalk).
|
|
*
|
|
* 802.2-encapsulated ETHERTYPE_AARP packets are
|
|
* SNAP packets with an organization code of
|
|
* 0x000000 (encapsulated Ethernet) and a protocol
|
|
* type of ETHERTYPE_AARP (Appletalk ARP).
|
|
*/
|
|
if (proto == ETHERTYPE_ATALK)
|
|
b1 = gen_snap(cstate, 0x080007, ETHERTYPE_ATALK);
|
|
else /* proto == ETHERTYPE_AARP */
|
|
b1 = gen_snap(cstate, 0x000000, ETHERTYPE_AARP);
|
|
gen_and(b0, b1);
|
|
|
|
/*
|
|
* Check for Ethernet encapsulation (Ethertalk
|
|
* phase 1?); we just check for the Ethernet
|
|
* protocol type.
|
|
*/
|
|
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
|
|
|
|
gen_or(b0, b1);
|
|
return b1;
|
|
|
|
default:
|
|
if (proto <= ETHERMTU) {
|
|
/*
|
|
* This is an LLC SAP value, so the frames
|
|
* that match would be 802.2 frames.
|
|
* Check that the frame is an 802.2 frame
|
|
* (i.e., that the length/type field is
|
|
* a length field, <= ETHERMTU) and
|
|
* then check the DSAP.
|
|
*/
|
|
b0 = gen_cmp_gt(cstate, OR_LINKTYPE, 0, BPF_H, ETHERMTU);
|
|
gen_not(b0);
|
|
b1 = gen_cmp(cstate, OR_LINKTYPE, 2, BPF_B, (bpf_int32)proto);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
} else {
|
|
/*
|
|
* This is an Ethernet type, so compare
|
|
* the length/type field with it (if
|
|
* the frame is an 802.2 frame, the length
|
|
* field will be <= ETHERMTU, and, as
|
|
* "proto" is > ETHERMTU, this test
|
|
* will fail and the frame won't match,
|
|
* which is what we want).
|
|
*/
|
|
return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H,
|
|
(bpf_int32)proto);
|
|
}
|
|
}
|
|
}
|
|
|
|
static struct block *
|
|
gen_loopback_linktype(compiler_state_t *cstate, int proto)
|
|
{
|
|
/*
|
|
* For DLT_NULL, the link-layer header is a 32-bit word
|
|
* containing an AF_ value in *host* byte order, and for
|
|
* DLT_ENC, the link-layer header begins with a 32-bit
|
|
* word containing an AF_ value in host byte order.
|
|
*
|
|
* In addition, if we're reading a saved capture file,
|
|
* the host byte order in the capture may not be the
|
|
* same as the host byte order on this machine.
|
|
*
|
|
* For DLT_LOOP, the link-layer header is a 32-bit
|
|
* word containing an AF_ value in *network* byte order.
|
|
*/
|
|
if (cstate->linktype == DLT_NULL || cstate->linktype == DLT_ENC) {
|
|
/*
|
|
* The AF_ value is in host byte order, but the BPF
|
|
* interpreter will convert it to network byte order.
|
|
*
|
|
* If this is a save file, and it's from a machine
|
|
* with the opposite byte order to ours, we byte-swap
|
|
* the AF_ value.
|
|
*
|
|
* Then we run it through "htonl()", and generate
|
|
* code to compare against the result.
|
|
*/
|
|
if (cstate->bpf_pcap->rfile != NULL && cstate->bpf_pcap->swapped)
|
|
proto = SWAPLONG(proto);
|
|
proto = htonl(proto);
|
|
}
|
|
return (gen_cmp(cstate, OR_LINKHDR, 0, BPF_W, (bpf_int32)proto));
|
|
}
|
|
|
|
/*
|
|
* "proto" is an Ethernet type value and for IPNET, if it is not IPv4
|
|
* or IPv6 then we have an error.
|
|
*/
|
|
static struct block *
|
|
gen_ipnet_linktype(compiler_state_t *cstate, int proto)
|
|
{
|
|
switch (proto) {
|
|
|
|
case ETHERTYPE_IP:
|
|
return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B, (bpf_int32)IPH_AF_INET);
|
|
/*NOTREACHED*/
|
|
|
|
case ETHERTYPE_IPV6:
|
|
return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
|
|
(bpf_int32)IPH_AF_INET6);
|
|
/*NOTREACHED*/
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return gen_false(cstate);
|
|
}
|
|
|
|
/*
|
|
* Generate code to match a particular packet type.
|
|
*
|
|
* "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
|
|
* value, if <= ETHERMTU. We use that to determine whether to
|
|
* match the type field or to check the type field for the special
|
|
* LINUX_SLL_P_802_2 value and then do the appropriate test.
|
|
*/
|
|
static struct block *
|
|
gen_linux_sll_linktype(compiler_state_t *cstate, int proto)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
switch (proto) {
|
|
|
|
case LLCSAP_ISONS:
|
|
case LLCSAP_IP:
|
|
case LLCSAP_NETBEUI:
|
|
/*
|
|
* OSI protocols and NetBEUI always use 802.2 encapsulation,
|
|
* so we check the DSAP and SSAP.
|
|
*
|
|
* LLCSAP_IP checks for IP-over-802.2, rather
|
|
* than IP-over-Ethernet or IP-over-SNAP.
|
|
*
|
|
* XXX - should we check both the DSAP and the
|
|
* SSAP, like this, or should we check just the
|
|
* DSAP, as we do for other types <= ETHERMTU
|
|
* (i.e., other SAP values)?
|
|
*/
|
|
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2);
|
|
b1 = gen_cmp(cstate, OR_LLC, 0, BPF_H, (bpf_int32)
|
|
((proto << 8) | proto));
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case LLCSAP_IPX:
|
|
/*
|
|
* Ethernet_II frames, which are Ethernet
|
|
* frames with a frame type of ETHERTYPE_IPX;
|
|
*
|
|
* Ethernet_802.3 frames, which have a frame
|
|
* type of LINUX_SLL_P_802_3;
|
|
*
|
|
* Ethernet_802.2 frames, which are 802.3
|
|
* frames with an 802.2 LLC header (i.e, have
|
|
* a frame type of LINUX_SLL_P_802_2) and
|
|
* with the IPX LSAP as the DSAP in the LLC
|
|
* header;
|
|
*
|
|
* Ethernet_SNAP frames, which are 802.3
|
|
* frames with an LLC header and a SNAP
|
|
* header and with an OUI of 0x000000
|
|
* (encapsulated Ethernet) and a protocol
|
|
* ID of ETHERTYPE_IPX in the SNAP header.
|
|
*
|
|
* First, do the checks on LINUX_SLL_P_802_2
|
|
* frames; generate the check for either
|
|
* Ethernet_802.2 or Ethernet_SNAP frames, and
|
|
* then put a check for LINUX_SLL_P_802_2 frames
|
|
* before it.
|
|
*/
|
|
b0 = gen_cmp(cstate, OR_LLC, 0, BPF_B, (bpf_int32)LLCSAP_IPX);
|
|
b1 = gen_snap(cstate, 0x000000, ETHERTYPE_IPX);
|
|
gen_or(b0, b1);
|
|
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2);
|
|
gen_and(b0, b1);
|
|
|
|
/*
|
|
* Now check for 802.3 frames and OR that with
|
|
* the previous test.
|
|
*/
|
|
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_3);
|
|
gen_or(b0, b1);
|
|
|
|
/*
|
|
* Now add the check for Ethernet_II frames, and
|
|
* do that before checking for the other frame
|
|
* types.
|
|
*/
|
|
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)ETHERTYPE_IPX);
|
|
gen_or(b0, b1);
|
|
return b1;
|
|
|
|
case ETHERTYPE_ATALK:
|
|
case ETHERTYPE_AARP:
|
|
/*
|
|
* EtherTalk (AppleTalk protocols on Ethernet link
|
|
* layer) may use 802.2 encapsulation.
|
|
*/
|
|
|
|
/*
|
|
* Check for 802.2 encapsulation (EtherTalk phase 2?);
|
|
* we check for the 802.2 protocol type in the
|
|
* "Ethernet type" field.
|
|
*/
|
|
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2);
|
|
|
|
/*
|
|
* 802.2-encapsulated ETHERTYPE_ATALK packets are
|
|
* SNAP packets with an organization code of
|
|
* 0x080007 (Apple, for Appletalk) and a protocol
|
|
* type of ETHERTYPE_ATALK (Appletalk).
|
|
*
|
|
* 802.2-encapsulated ETHERTYPE_AARP packets are
|
|
* SNAP packets with an organization code of
|
|
* 0x000000 (encapsulated Ethernet) and a protocol
|
|
* type of ETHERTYPE_AARP (Appletalk ARP).
|
|
*/
|
|
if (proto == ETHERTYPE_ATALK)
|
|
b1 = gen_snap(cstate, 0x080007, ETHERTYPE_ATALK);
|
|
else /* proto == ETHERTYPE_AARP */
|
|
b1 = gen_snap(cstate, 0x000000, ETHERTYPE_AARP);
|
|
gen_and(b0, b1);
|
|
|
|
/*
|
|
* Check for Ethernet encapsulation (Ethertalk
|
|
* phase 1?); we just check for the Ethernet
|
|
* protocol type.
|
|
*/
|
|
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
|
|
|
|
gen_or(b0, b1);
|
|
return b1;
|
|
|
|
default:
|
|
if (proto <= ETHERMTU) {
|
|
/*
|
|
* This is an LLC SAP value, so the frames
|
|
* that match would be 802.2 frames.
|
|
* Check for the 802.2 protocol type
|
|
* in the "Ethernet type" field, and
|
|
* then check the DSAP.
|
|
*/
|
|
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2);
|
|
b1 = gen_cmp(cstate, OR_LINKHDR, cstate->off_linkpl.constant_part, BPF_B,
|
|
(bpf_int32)proto);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
} else {
|
|
/*
|
|
* This is an Ethernet type, so compare
|
|
* the length/type field with it (if
|
|
* the frame is an 802.2 frame, the length
|
|
* field will be <= ETHERMTU, and, as
|
|
* "proto" is > ETHERMTU, this test
|
|
* will fail and the frame won't match,
|
|
* which is what we want).
|
|
*/
|
|
return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
|
|
}
|
|
}
|
|
}
|
|
|
|
static struct slist *
|
|
gen_load_prism_llprefixlen(compiler_state_t *cstate)
|
|
{
|
|
struct slist *s1, *s2;
|
|
struct slist *sjeq_avs_cookie;
|
|
struct slist *sjcommon;
|
|
|
|
/*
|
|
* This code is not compatible with the optimizer, as
|
|
* we are generating jmp instructions within a normal
|
|
* slist of instructions
|
|
*/
|
|
cstate->no_optimize = 1;
|
|
|
|
/*
|
|
* Generate code to load the length of the radio header into
|
|
* the register assigned to hold that length, if one has been
|
|
* assigned. (If one hasn't been assigned, no code we've
|
|
* generated uses that prefix, so we don't need to generate any
|
|
* code to load it.)
|
|
*
|
|
* Some Linux drivers use ARPHRD_IEEE80211_PRISM but sometimes
|
|
* or always use the AVS header rather than the Prism header.
|
|
* We load a 4-byte big-endian value at the beginning of the
|
|
* raw packet data, and see whether, when masked with 0xFFFFF000,
|
|
* it's equal to 0x80211000. If so, that indicates that it's
|
|
* an AVS header (the masked-out bits are the version number).
|
|
* Otherwise, it's a Prism header.
|
|
*
|
|
* XXX - the Prism header is also, in theory, variable-length,
|
|
* but no known software generates headers that aren't 144
|
|
* bytes long.
|
|
*/
|
|
if (cstate->off_linkhdr.reg != -1) {
|
|
/*
|
|
* Load the cookie.
|
|
*/
|
|
s1 = new_stmt(cstate, BPF_LD|BPF_W|BPF_ABS);
|
|
s1->s.k = 0;
|
|
|
|
/*
|
|
* AND it with 0xFFFFF000.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_K);
|
|
s2->s.k = 0xFFFFF000;
|
|
sappend(s1, s2);
|
|
|
|
/*
|
|
* Compare with 0x80211000.
|
|
*/
|
|
sjeq_avs_cookie = new_stmt(cstate, JMP(BPF_JEQ));
|
|
sjeq_avs_cookie->s.k = 0x80211000;
|
|
sappend(s1, sjeq_avs_cookie);
|
|
|
|
/*
|
|
* If it's AVS:
|
|
*
|
|
* The 4 bytes at an offset of 4 from the beginning of
|
|
* the AVS header are the length of the AVS header.
|
|
* That field is big-endian.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_LD|BPF_W|BPF_ABS);
|
|
s2->s.k = 4;
|
|
sappend(s1, s2);
|
|
sjeq_avs_cookie->s.jt = s2;
|
|
|
|
/*
|
|
* Now jump to the code to allocate a register
|
|
* into which to save the header length and
|
|
* store the length there. (The "jump always"
|
|
* instruction needs to have the k field set;
|
|
* it's added to the PC, so, as we're jumping
|
|
* over a single instruction, it should be 1.)
|
|
*/
|
|
sjcommon = new_stmt(cstate, JMP(BPF_JA));
|
|
sjcommon->s.k = 1;
|
|
sappend(s1, sjcommon);
|
|
|
|
/*
|
|
* Now for the code that handles the Prism header.
|
|
* Just load the length of the Prism header (144)
|
|
* into the A register. Have the test for an AVS
|
|
* header branch here if we don't have an AVS header.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_LD|BPF_W|BPF_IMM);
|
|
s2->s.k = 144;
|
|
sappend(s1, s2);
|
|
sjeq_avs_cookie->s.jf = s2;
|
|
|
|
/*
|
|
* Now allocate a register to hold that value and store
|
|
* it. The code for the AVS header will jump here after
|
|
* loading the length of the AVS header.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_ST);
|
|
s2->s.k = cstate->off_linkhdr.reg;
|
|
sappend(s1, s2);
|
|
sjcommon->s.jf = s2;
|
|
|
|
/*
|
|
* Now move it into the X register.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_MISC|BPF_TAX);
|
|
sappend(s1, s2);
|
|
|
|
return (s1);
|
|
} else
|
|
return (NULL);
|
|
}
|
|
|
|
static struct slist *
|
|
gen_load_avs_llprefixlen(compiler_state_t *cstate)
|
|
{
|
|
struct slist *s1, *s2;
|
|
|
|
/*
|
|
* Generate code to load the length of the AVS header into
|
|
* the register assigned to hold that length, if one has been
|
|
* assigned. (If one hasn't been assigned, no code we've
|
|
* generated uses that prefix, so we don't need to generate any
|
|
* code to load it.)
|
|
*/
|
|
if (cstate->off_linkhdr.reg != -1) {
|
|
/*
|
|
* The 4 bytes at an offset of 4 from the beginning of
|
|
* the AVS header are the length of the AVS header.
|
|
* That field is big-endian.
|
|
*/
|
|
s1 = new_stmt(cstate, BPF_LD|BPF_W|BPF_ABS);
|
|
s1->s.k = 4;
|
|
|
|
/*
|
|
* Now allocate a register to hold that value and store
|
|
* it.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_ST);
|
|
s2->s.k = cstate->off_linkhdr.reg;
|
|
sappend(s1, s2);
|
|
|
|
/*
|
|
* Now move it into the X register.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_MISC|BPF_TAX);
|
|
sappend(s1, s2);
|
|
|
|
return (s1);
|
|
} else
|
|
return (NULL);
|
|
}
|
|
|
|
static struct slist *
|
|
gen_load_radiotap_llprefixlen(compiler_state_t *cstate)
|
|
{
|
|
struct slist *s1, *s2;
|
|
|
|
/*
|
|
* Generate code to load the length of the radiotap header into
|
|
* the register assigned to hold that length, if one has been
|
|
* assigned. (If one hasn't been assigned, no code we've
|
|
* generated uses that prefix, so we don't need to generate any
|
|
* code to load it.)
|
|
*/
|
|
if (cstate->off_linkhdr.reg != -1) {
|
|
/*
|
|
* The 2 bytes at offsets of 2 and 3 from the beginning
|
|
* of the radiotap header are the length of the radiotap
|
|
* header; unfortunately, it's little-endian, so we have
|
|
* to load it a byte at a time and construct the value.
|
|
*/
|
|
|
|
/*
|
|
* Load the high-order byte, at an offset of 3, shift it
|
|
* left a byte, and put the result in the X register.
|
|
*/
|
|
s1 = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS);
|
|
s1->s.k = 3;
|
|
s2 = new_stmt(cstate, BPF_ALU|BPF_LSH|BPF_K);
|
|
sappend(s1, s2);
|
|
s2->s.k = 8;
|
|
s2 = new_stmt(cstate, BPF_MISC|BPF_TAX);
|
|
sappend(s1, s2);
|
|
|
|
/*
|
|
* Load the next byte, at an offset of 2, and OR the
|
|
* value from the X register into it.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS);
|
|
sappend(s1, s2);
|
|
s2->s.k = 2;
|
|
s2 = new_stmt(cstate, BPF_ALU|BPF_OR|BPF_X);
|
|
sappend(s1, s2);
|
|
|
|
/*
|
|
* Now allocate a register to hold that value and store
|
|
* it.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_ST);
|
|
s2->s.k = cstate->off_linkhdr.reg;
|
|
sappend(s1, s2);
|
|
|
|
/*
|
|
* Now move it into the X register.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_MISC|BPF_TAX);
|
|
sappend(s1, s2);
|
|
|
|
return (s1);
|
|
} else
|
|
return (NULL);
|
|
}
|
|
|
|
/*
|
|
* At the moment we treat PPI as normal Radiotap encoded
|
|
* packets. The difference is in the function that generates
|
|
* the code at the beginning to compute the header length.
|
|
* Since this code generator of PPI supports bare 802.11
|
|
* encapsulation only (i.e. the encapsulated DLT should be
|
|
* DLT_IEEE802_11) we generate code to check for this too;
|
|
* that's done in finish_parse().
|
|
*/
|
|
static struct slist *
|
|
gen_load_ppi_llprefixlen(compiler_state_t *cstate)
|
|
{
|
|
struct slist *s1, *s2;
|
|
|
|
/*
|
|
* Generate code to load the length of the radiotap header
|
|
* into the register assigned to hold that length, if one has
|
|
* been assigned.
|
|
*/
|
|
if (cstate->off_linkhdr.reg != -1) {
|
|
/*
|
|
* The 2 bytes at offsets of 2 and 3 from the beginning
|
|
* of the radiotap header are the length of the radiotap
|
|
* header; unfortunately, it's little-endian, so we have
|
|
* to load it a byte at a time and construct the value.
|
|
*/
|
|
|
|
/*
|
|
* Load the high-order byte, at an offset of 3, shift it
|
|
* left a byte, and put the result in the X register.
|
|
*/
|
|
s1 = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS);
|
|
s1->s.k = 3;
|
|
s2 = new_stmt(cstate, BPF_ALU|BPF_LSH|BPF_K);
|
|
sappend(s1, s2);
|
|
s2->s.k = 8;
|
|
s2 = new_stmt(cstate, BPF_MISC|BPF_TAX);
|
|
sappend(s1, s2);
|
|
|
|
/*
|
|
* Load the next byte, at an offset of 2, and OR the
|
|
* value from the X register into it.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS);
|
|
sappend(s1, s2);
|
|
s2->s.k = 2;
|
|
s2 = new_stmt(cstate, BPF_ALU|BPF_OR|BPF_X);
|
|
sappend(s1, s2);
|
|
|
|
/*
|
|
* Now allocate a register to hold that value and store
|
|
* it.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_ST);
|
|
s2->s.k = cstate->off_linkhdr.reg;
|
|
sappend(s1, s2);
|
|
|
|
/*
|
|
* Now move it into the X register.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_MISC|BPF_TAX);
|
|
sappend(s1, s2);
|
|
|
|
return (s1);
|
|
} else
|
|
return (NULL);
|
|
}
|
|
|
|
/*
|
|
* Load a value relative to the beginning of the link-layer header after the 802.11
|
|
* header, i.e. LLC_SNAP.
|
|
* The link-layer header doesn't necessarily begin at the beginning
|
|
* of the packet data; there might be a variable-length prefix containing
|
|
* radio information.
|
|
*/
|
|
static struct slist *
|
|
gen_load_802_11_header_len(compiler_state_t *cstate, struct slist *s, struct slist *snext)
|
|
{
|
|
struct slist *s2;
|
|
struct slist *sjset_data_frame_1;
|
|
struct slist *sjset_data_frame_2;
|
|
struct slist *sjset_qos;
|
|
struct slist *sjset_radiotap_flags_present;
|
|
struct slist *sjset_radiotap_ext_present;
|
|
struct slist *sjset_radiotap_tsft_present;
|
|
struct slist *sjset_tsft_datapad, *sjset_notsft_datapad;
|
|
struct slist *s_roundup;
|
|
|
|
if (cstate->off_linkpl.reg == -1) {
|
|
/*
|
|
* No register has been assigned to the offset of
|
|
* the link-layer payload, which means nobody needs
|
|
* it; don't bother computing it - just return
|
|
* what we already have.
|
|
*/
|
|
return (s);
|
|
}
|
|
|
|
/*
|
|
* This code is not compatible with the optimizer, as
|
|
* we are generating jmp instructions within a normal
|
|
* slist of instructions
|
|
*/
|
|
cstate->no_optimize = 1;
|
|
|
|
/*
|
|
* If "s" is non-null, it has code to arrange that the X register
|
|
* contains the length of the prefix preceding the link-layer
|
|
* header.
|
|
*
|
|
* Otherwise, the length of the prefix preceding the link-layer
|
|
* header is "off_outermostlinkhdr.constant_part".
|
|
*/
|
|
if (s == NULL) {
|
|
/*
|
|
* There is no variable-length header preceding the
|
|
* link-layer header.
|
|
*
|
|
* Load the length of the fixed-length prefix preceding
|
|
* the link-layer header (if any) into the X register,
|
|
* and store it in the cstate->off_linkpl.reg register.
|
|
* That length is off_outermostlinkhdr.constant_part.
|
|
*/
|
|
s = new_stmt(cstate, BPF_LDX|BPF_IMM);
|
|
s->s.k = cstate->off_outermostlinkhdr.constant_part;
|
|
}
|
|
|
|
/*
|
|
* The X register contains the offset of the beginning of the
|
|
* link-layer header; add 24, which is the minimum length
|
|
* of the MAC header for a data frame, to that, and store it
|
|
* in cstate->off_linkpl.reg, and then load the Frame Control field,
|
|
* which is at the offset in the X register, with an indexed load.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_MISC|BPF_TXA);
|
|
sappend(s, s2);
|
|
s2 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
|
|
s2->s.k = 24;
|
|
sappend(s, s2);
|
|
s2 = new_stmt(cstate, BPF_ST);
|
|
s2->s.k = cstate->off_linkpl.reg;
|
|
sappend(s, s2);
|
|
|
|
s2 = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B);
|
|
s2->s.k = 0;
|
|
sappend(s, s2);
|
|
|
|
/*
|
|
* Check the Frame Control field to see if this is a data frame;
|
|
* a data frame has the 0x08 bit (b3) in that field set and the
|
|
* 0x04 bit (b2) clear.
|
|
*/
|
|
sjset_data_frame_1 = new_stmt(cstate, JMP(BPF_JSET));
|
|
sjset_data_frame_1->s.k = 0x08;
|
|
sappend(s, sjset_data_frame_1);
|
|
|
|
/*
|
|
* If b3 is set, test b2, otherwise go to the first statement of
|
|
* the rest of the program.
|
|
*/
|
|
sjset_data_frame_1->s.jt = sjset_data_frame_2 = new_stmt(cstate, JMP(BPF_JSET));
|
|
sjset_data_frame_2->s.k = 0x04;
|
|
sappend(s, sjset_data_frame_2);
|
|
sjset_data_frame_1->s.jf = snext;
|
|
|
|
/*
|
|
* If b2 is not set, this is a data frame; test the QoS bit.
|
|
* Otherwise, go to the first statement of the rest of the
|
|
* program.
|
|
*/
|
|
sjset_data_frame_2->s.jt = snext;
|
|
sjset_data_frame_2->s.jf = sjset_qos = new_stmt(cstate, JMP(BPF_JSET));
|
|
sjset_qos->s.k = 0x80; /* QoS bit */
|
|
sappend(s, sjset_qos);
|
|
|
|
/*
|
|
* If it's set, add 2 to cstate->off_linkpl.reg, to skip the QoS
|
|
* field.
|
|
* Otherwise, go to the first statement of the rest of the
|
|
* program.
|
|
*/
|
|
sjset_qos->s.jt = s2 = new_stmt(cstate, BPF_LD|BPF_MEM);
|
|
s2->s.k = cstate->off_linkpl.reg;
|
|
sappend(s, s2);
|
|
s2 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_IMM);
|
|
s2->s.k = 2;
|
|
sappend(s, s2);
|
|
s2 = new_stmt(cstate, BPF_ST);
|
|
s2->s.k = cstate->off_linkpl.reg;
|
|
sappend(s, s2);
|
|
|
|
/*
|
|
* If we have a radiotap header, look at it to see whether
|
|
* there's Atheros padding between the MAC-layer header
|
|
* and the payload.
|
|
*
|
|
* Note: all of the fields in the radiotap header are
|
|
* little-endian, so we byte-swap all of the values
|
|
* we test against, as they will be loaded as big-endian
|
|
* values.
|
|
*
|
|
* XXX - in the general case, we would have to scan through
|
|
* *all* the presence bits, if there's more than one word of
|
|
* presence bits. That would require a loop, meaning that
|
|
* we wouldn't be able to run the filter in the kernel.
|
|
*
|
|
* We assume here that the Atheros adapters that insert the
|
|
* annoying padding don't have multiple antennae and therefore
|
|
* do not generate radiotap headers with multiple presence words.
|
|
*/
|
|
if (cstate->linktype == DLT_IEEE802_11_RADIO) {
|
|
/*
|
|
* Is the IEEE80211_RADIOTAP_FLAGS bit (0x0000002) set
|
|
* in the first presence flag word?
|
|
*/
|
|
sjset_qos->s.jf = s2 = new_stmt(cstate, BPF_LD|BPF_ABS|BPF_W);
|
|
s2->s.k = 4;
|
|
sappend(s, s2);
|
|
|
|
sjset_radiotap_flags_present = new_stmt(cstate, JMP(BPF_JSET));
|
|
sjset_radiotap_flags_present->s.k = SWAPLONG(0x00000002);
|
|
sappend(s, sjset_radiotap_flags_present);
|
|
|
|
/*
|
|
* If not, skip all of this.
|
|
*/
|
|
sjset_radiotap_flags_present->s.jf = snext;
|
|
|
|
/*
|
|
* Otherwise, is the "extension" bit set in that word?
|
|
*/
|
|
sjset_radiotap_ext_present = new_stmt(cstate, JMP(BPF_JSET));
|
|
sjset_radiotap_ext_present->s.k = SWAPLONG(0x80000000);
|
|
sappend(s, sjset_radiotap_ext_present);
|
|
sjset_radiotap_flags_present->s.jt = sjset_radiotap_ext_present;
|
|
|
|
/*
|
|
* If so, skip all of this.
|
|
*/
|
|
sjset_radiotap_ext_present->s.jt = snext;
|
|
|
|
/*
|
|
* Otherwise, is the IEEE80211_RADIOTAP_TSFT bit set?
|
|
*/
|
|
sjset_radiotap_tsft_present = new_stmt(cstate, JMP(BPF_JSET));
|
|
sjset_radiotap_tsft_present->s.k = SWAPLONG(0x00000001);
|
|
sappend(s, sjset_radiotap_tsft_present);
|
|
sjset_radiotap_ext_present->s.jf = sjset_radiotap_tsft_present;
|
|
|
|
/*
|
|
* If IEEE80211_RADIOTAP_TSFT is set, the flags field is
|
|
* at an offset of 16 from the beginning of the raw packet
|
|
* data (8 bytes for the radiotap header and 8 bytes for
|
|
* the TSFT field).
|
|
*
|
|
* Test whether the IEEE80211_RADIOTAP_F_DATAPAD bit (0x20)
|
|
* is set.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_LD|BPF_ABS|BPF_B);
|
|
s2->s.k = 16;
|
|
sappend(s, s2);
|
|
sjset_radiotap_tsft_present->s.jt = s2;
|
|
|
|
sjset_tsft_datapad = new_stmt(cstate, JMP(BPF_JSET));
|
|
sjset_tsft_datapad->s.k = 0x20;
|
|
sappend(s, sjset_tsft_datapad);
|
|
|
|
/*
|
|
* If IEEE80211_RADIOTAP_TSFT is not set, the flags field is
|
|
* at an offset of 8 from the beginning of the raw packet
|
|
* data (8 bytes for the radiotap header).
|
|
*
|
|
* Test whether the IEEE80211_RADIOTAP_F_DATAPAD bit (0x20)
|
|
* is set.
|
|
*/
|
|
s2 = new_stmt(cstate, BPF_LD|BPF_ABS|BPF_B);
|
|
s2->s.k = 8;
|
|
sappend(s, s2);
|
|
sjset_radiotap_tsft_present->s.jf = s2;
|
|
|
|
sjset_notsft_datapad = new_stmt(cstate, JMP(BPF_JSET));
|
|
sjset_notsft_datapad->s.k = 0x20;
|
|
sappend(s, sjset_notsft_datapad);
|
|
|
|
/*
|
|
* In either case, if IEEE80211_RADIOTAP_F_DATAPAD is
|
|
* set, round the length of the 802.11 header to
|
|
* a multiple of 4. Do that by adding 3 and then
|
|
* dividing by and multiplying by 4, which we do by
|
|
* ANDing with ~3.
|
|
*/
|
|
s_roundup = new_stmt(cstate, BPF_LD|BPF_MEM);
|
|
s_roundup->s.k = cstate->off_linkpl.reg;
|
|
sappend(s, s_roundup);
|
|
s2 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_IMM);
|
|
s2->s.k = 3;
|
|
sappend(s, s2);
|
|
s2 = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_IMM);
|
|
s2->s.k = ~3;
|
|
sappend(s, s2);
|
|
s2 = new_stmt(cstate, BPF_ST);
|
|
s2->s.k = cstate->off_linkpl.reg;
|
|
sappend(s, s2);
|
|
|
|
sjset_tsft_datapad->s.jt = s_roundup;
|
|
sjset_tsft_datapad->s.jf = snext;
|
|
sjset_notsft_datapad->s.jt = s_roundup;
|
|
sjset_notsft_datapad->s.jf = snext;
|
|
} else
|
|
sjset_qos->s.jf = snext;
|
|
|
|
return s;
|
|
}
|
|
|
|
static void
|
|
insert_compute_vloffsets(compiler_state_t *cstate, struct block *b)
|
|
{
|
|
struct slist *s;
|
|
|
|
/* There is an implicit dependency between the link
|
|
* payload and link header since the payload computation
|
|
* includes the variable part of the header. Therefore,
|
|
* if nobody else has allocated a register for the link
|
|
* header and we need it, do it now. */
|
|
if (cstate->off_linkpl.reg != -1 && cstate->off_linkhdr.is_variable &&
|
|
cstate->off_linkhdr.reg == -1)
|
|
cstate->off_linkhdr.reg = alloc_reg(cstate);
|
|
|
|
/*
|
|
* For link-layer types that have a variable-length header
|
|
* preceding the link-layer header, generate code to load
|
|
* the offset of the link-layer header into the register
|
|
* assigned to that offset, if any.
|
|
*
|
|
* XXX - this, and the next switch statement, won't handle
|
|
* encapsulation of 802.11 or 802.11+radio information in
|
|
* some other protocol stack. That's significantly more
|
|
* complicated.
|
|
*/
|
|
switch (cstate->outermostlinktype) {
|
|
|
|
case DLT_PRISM_HEADER:
|
|
s = gen_load_prism_llprefixlen(cstate);
|
|
break;
|
|
|
|
case DLT_IEEE802_11_RADIO_AVS:
|
|
s = gen_load_avs_llprefixlen(cstate);
|
|
break;
|
|
|
|
case DLT_IEEE802_11_RADIO:
|
|
s = gen_load_radiotap_llprefixlen(cstate);
|
|
break;
|
|
|
|
case DLT_PPI:
|
|
s = gen_load_ppi_llprefixlen(cstate);
|
|
break;
|
|
|
|
default:
|
|
s = NULL;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* For link-layer types that have a variable-length link-layer
|
|
* header, generate code to load the offset of the link-layer
|
|
* payload into the register assigned to that offset, if any.
|
|
*/
|
|
switch (cstate->outermostlinktype) {
|
|
|
|
case DLT_IEEE802_11:
|
|
case DLT_PRISM_HEADER:
|
|
case DLT_IEEE802_11_RADIO_AVS:
|
|
case DLT_IEEE802_11_RADIO:
|
|
case DLT_PPI:
|
|
s = gen_load_802_11_header_len(cstate, s, b->stmts);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* If there there is no initialization yet and we need variable
|
|
* length offsets for VLAN, initialize them to zero
|
|
*/
|
|
if (s == NULL && cstate->is_vlan_vloffset) {
|
|
struct slist *s2;
|
|
|
|
if (cstate->off_linkpl.reg == -1)
|
|
cstate->off_linkpl.reg = alloc_reg(cstate);
|
|
if (cstate->off_linktype.reg == -1)
|
|
cstate->off_linktype.reg = alloc_reg(cstate);
|
|
|
|
s = new_stmt(cstate, BPF_LD|BPF_W|BPF_IMM);
|
|
s->s.k = 0;
|
|
s2 = new_stmt(cstate, BPF_ST);
|
|
s2->s.k = cstate->off_linkpl.reg;
|
|
sappend(s, s2);
|
|
s2 = new_stmt(cstate, BPF_ST);
|
|
s2->s.k = cstate->off_linktype.reg;
|
|
sappend(s, s2);
|
|
}
|
|
|
|
/*
|
|
* If we have any offset-loading code, append all the
|
|
* existing statements in the block to those statements,
|
|
* and make the resulting list the list of statements
|
|
* for the block.
|
|
*/
|
|
if (s != NULL) {
|
|
sappend(s, b->stmts);
|
|
b->stmts = s;
|
|
}
|
|
}
|
|
|
|
static struct block *
|
|
gen_ppi_dlt_check(compiler_state_t *cstate)
|
|
{
|
|
struct slist *s_load_dlt;
|
|
struct block *b;
|
|
|
|
if (cstate->linktype == DLT_PPI)
|
|
{
|
|
/* Create the statements that check for the DLT
|
|
*/
|
|
s_load_dlt = new_stmt(cstate, BPF_LD|BPF_W|BPF_ABS);
|
|
s_load_dlt->s.k = 4;
|
|
|
|
b = new_block(cstate, JMP(BPF_JEQ));
|
|
|
|
b->stmts = s_load_dlt;
|
|
b->s.k = SWAPLONG(DLT_IEEE802_11);
|
|
}
|
|
else
|
|
{
|
|
b = NULL;
|
|
}
|
|
|
|
return b;
|
|
}
|
|
|
|
/*
|
|
* Take an absolute offset, and:
|
|
*
|
|
* if it has no variable part, return NULL;
|
|
*
|
|
* if it has a variable part, generate code to load the register
|
|
* containing that variable part into the X register, returning
|
|
* a pointer to that code - if no register for that offset has
|
|
* been allocated, allocate it first.
|
|
*
|
|
* (The code to set that register will be generated later, but will
|
|
* be placed earlier in the code sequence.)
|
|
*/
|
|
static struct slist *
|
|
gen_abs_offset_varpart(compiler_state_t *cstate, bpf_abs_offset *off)
|
|
{
|
|
struct slist *s;
|
|
|
|
if (off->is_variable) {
|
|
if (off->reg == -1) {
|
|
/*
|
|
* We haven't yet assigned a register for the
|
|
* variable part of the offset of the link-layer
|
|
* header; allocate one.
|
|
*/
|
|
off->reg = alloc_reg(cstate);
|
|
}
|
|
|
|
/*
|
|
* Load the register containing the variable part of the
|
|
* offset of the link-layer header into the X register.
|
|
*/
|
|
s = new_stmt(cstate, BPF_LDX|BPF_MEM);
|
|
s->s.k = off->reg;
|
|
return s;
|
|
} else {
|
|
/*
|
|
* That offset isn't variable, there's no variable part,
|
|
* so we don't need to generate any code.
|
|
*/
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Map an Ethernet type to the equivalent PPP type.
|
|
*/
|
|
static int
|
|
ethertype_to_ppptype(int proto)
|
|
{
|
|
switch (proto) {
|
|
|
|
case ETHERTYPE_IP:
|
|
proto = PPP_IP;
|
|
break;
|
|
|
|
case ETHERTYPE_IPV6:
|
|
proto = PPP_IPV6;
|
|
break;
|
|
|
|
case ETHERTYPE_DN:
|
|
proto = PPP_DECNET;
|
|
break;
|
|
|
|
case ETHERTYPE_ATALK:
|
|
proto = PPP_APPLE;
|
|
break;
|
|
|
|
case ETHERTYPE_NS:
|
|
proto = PPP_NS;
|
|
break;
|
|
|
|
case LLCSAP_ISONS:
|
|
proto = PPP_OSI;
|
|
break;
|
|
|
|
case LLCSAP_8021D:
|
|
/*
|
|
* I'm assuming the "Bridging PDU"s that go
|
|
* over PPP are Spanning Tree Protocol
|
|
* Bridging PDUs.
|
|
*/
|
|
proto = PPP_BRPDU;
|
|
break;
|
|
|
|
case LLCSAP_IPX:
|
|
proto = PPP_IPX;
|
|
break;
|
|
}
|
|
return (proto);
|
|
}
|
|
|
|
/*
|
|
* Generate any tests that, for encapsulation of a link-layer packet
|
|
* inside another protocol stack, need to be done to check for those
|
|
* link-layer packets (and that haven't already been done by a check
|
|
* for that encapsulation).
|
|
*/
|
|
static struct block *
|
|
gen_prevlinkhdr_check(compiler_state_t *cstate)
|
|
{
|
|
struct block *b0;
|
|
|
|
if (cstate->is_geneve)
|
|
return gen_geneve_ll_check(cstate);
|
|
|
|
switch (cstate->prevlinktype) {
|
|
|
|
case DLT_SUNATM:
|
|
/*
|
|
* This is LANE-encapsulated Ethernet; check that the LANE
|
|
* packet doesn't begin with an LE Control marker, i.e.
|
|
* that it's data, not a control message.
|
|
*
|
|
* (We've already generated a test for LANE.)
|
|
*/
|
|
b0 = gen_cmp(cstate, OR_PREVLINKHDR, SUNATM_PKT_BEGIN_POS, BPF_H, 0xFF00);
|
|
gen_not(b0);
|
|
return b0;
|
|
|
|
default:
|
|
/*
|
|
* No such tests are necessary.
|
|
*/
|
|
return NULL;
|
|
}
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
/*
|
|
* The three different values we should check for when checking for an
|
|
* IPv6 packet with DLT_NULL.
|
|
*/
|
|
#define BSD_AFNUM_INET6_BSD 24 /* NetBSD, OpenBSD, BSD/OS, Npcap */
|
|
#define BSD_AFNUM_INET6_FREEBSD 28 /* FreeBSD */
|
|
#define BSD_AFNUM_INET6_DARWIN 30 /* macOS, iOS, other Darwin-based OSes */
|
|
|
|
/*
|
|
* Generate code to match a particular packet type by matching the
|
|
* link-layer type field or fields in the 802.2 LLC header.
|
|
*
|
|
* "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
|
|
* value, if <= ETHERMTU.
|
|
*/
|
|
static struct block *
|
|
gen_linktype(compiler_state_t *cstate, int proto)
|
|
{
|
|
struct block *b0, *b1, *b2;
|
|
const char *description;
|
|
|
|
/* are we checking MPLS-encapsulated packets? */
|
|
if (cstate->label_stack_depth > 0) {
|
|
switch (proto) {
|
|
case ETHERTYPE_IP:
|
|
case PPP_IP:
|
|
/* FIXME add other L3 proto IDs */
|
|
return gen_mpls_linktype(cstate, Q_IP);
|
|
|
|
case ETHERTYPE_IPV6:
|
|
case PPP_IPV6:
|
|
/* FIXME add other L3 proto IDs */
|
|
return gen_mpls_linktype(cstate, Q_IPV6);
|
|
|
|
default:
|
|
bpf_error(cstate, "unsupported protocol over mpls");
|
|
/*NOTREACHED*/
|
|
}
|
|
}
|
|
|
|
switch (cstate->linktype) {
|
|
|
|
case DLT_EN10MB:
|
|
case DLT_NETANALYZER:
|
|
case DLT_NETANALYZER_TRANSPARENT:
|
|
/* Geneve has an EtherType regardless of whether there is an
|
|
* L2 header. */
|
|
if (!cstate->is_geneve)
|
|
b0 = gen_prevlinkhdr_check(cstate);
|
|
else
|
|
b0 = NULL;
|
|
|
|
b1 = gen_ether_linktype(cstate, proto);
|
|
if (b0 != NULL)
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
/*NOTREACHED*/
|
|
|
|
case DLT_C_HDLC:
|
|
switch (proto) {
|
|
|
|
case LLCSAP_ISONS:
|
|
proto = (proto << 8 | LLCSAP_ISONS);
|
|
/* fall through */
|
|
|
|
default:
|
|
return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
case DLT_IEEE802_11:
|
|
case DLT_PRISM_HEADER:
|
|
case DLT_IEEE802_11_RADIO_AVS:
|
|
case DLT_IEEE802_11_RADIO:
|
|
case DLT_PPI:
|
|
/*
|
|
* Check that we have a data frame.
|
|
*/
|
|
b0 = gen_check_802_11_data_frame(cstate);
|
|
|
|
/*
|
|
* Now check for the specified link-layer type.
|
|
*/
|
|
b1 = gen_llc_linktype(cstate, proto);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
/*NOTREACHED*/
|
|
|
|
case DLT_FDDI:
|
|
/*
|
|
* XXX - check for LLC frames.
|
|
*/
|
|
return gen_llc_linktype(cstate, proto);
|
|
/*NOTREACHED*/
|
|
|
|
case DLT_IEEE802:
|
|
/*
|
|
* XXX - check for LLC PDUs, as per IEEE 802.5.
|
|
*/
|
|
return gen_llc_linktype(cstate, proto);
|
|
/*NOTREACHED*/
|
|
|
|
case DLT_ATM_RFC1483:
|
|
case DLT_ATM_CLIP:
|
|
case DLT_IP_OVER_FC:
|
|
return gen_llc_linktype(cstate, proto);
|
|
/*NOTREACHED*/
|
|
|
|
case DLT_SUNATM:
|
|
/*
|
|
* Check for an LLC-encapsulated version of this protocol;
|
|
* if we were checking for LANE, linktype would no longer
|
|
* be DLT_SUNATM.
|
|
*
|
|
* Check for LLC encapsulation and then check the protocol.
|
|
*/
|
|
b0 = gen_atmfield_code_internal(cstate, A_PROTOTYPE, PT_LLC, BPF_JEQ, 0);
|
|
b1 = gen_llc_linktype(cstate, proto);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
/*NOTREACHED*/
|
|
|
|
case DLT_LINUX_SLL:
|
|
return gen_linux_sll_linktype(cstate, proto);
|
|
/*NOTREACHED*/
|
|
|
|
case DLT_SLIP:
|
|
case DLT_SLIP_BSDOS:
|
|
case DLT_RAW:
|
|
/*
|
|
* These types don't provide any type field; packets
|
|
* are always IPv4 or IPv6.
|
|
*
|
|
* XXX - for IPv4, check for a version number of 4, and,
|
|
* for IPv6, check for a version number of 6?
|
|
*/
|
|
switch (proto) {
|
|
|
|
case ETHERTYPE_IP:
|
|
/* Check for a version number of 4. */
|
|
return gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, 0x40, 0xF0);
|
|
|
|
case ETHERTYPE_IPV6:
|
|
/* Check for a version number of 6. */
|
|
return gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, 0x60, 0xF0);
|
|
|
|
default:
|
|
return gen_false(cstate); /* always false */
|
|
}
|
|
/*NOTREACHED*/
|
|
|
|
case DLT_IPV4:
|
|
/*
|
|
* Raw IPv4, so no type field.
|
|
*/
|
|
if (proto == ETHERTYPE_IP)
|
|
return gen_true(cstate); /* always true */
|
|
|
|
/* Checking for something other than IPv4; always false */
|
|
return gen_false(cstate);
|
|
/*NOTREACHED*/
|
|
|
|
case DLT_IPV6:
|
|
/*
|
|
* Raw IPv6, so no type field.
|
|
*/
|
|
if (proto == ETHERTYPE_IPV6)
|
|
return gen_true(cstate); /* always true */
|
|
|
|
/* Checking for something other than IPv6; always false */
|
|
return gen_false(cstate);
|
|
/*NOTREACHED*/
|
|
|
|
case DLT_PPP:
|
|
case DLT_PPP_PPPD:
|
|
case DLT_PPP_SERIAL:
|
|
case DLT_PPP_ETHER:
|
|
/*
|
|
* We use Ethernet protocol types inside libpcap;
|
|
* map them to the corresponding PPP protocol types.
|
|
*/
|
|
proto = ethertype_to_ppptype(proto);
|
|
return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
|
|
/*NOTREACHED*/
|
|
|
|
case DLT_PPP_BSDOS:
|
|
/*
|
|
* We use Ethernet protocol types inside libpcap;
|
|
* map them to the corresponding PPP protocol types.
|
|
*/
|
|
switch (proto) {
|
|
|
|
case ETHERTYPE_IP:
|
|
/*
|
|
* Also check for Van Jacobson-compressed IP.
|
|
* XXX - do this for other forms of PPP?
|
|
*/
|
|
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, PPP_IP);
|
|
b1 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, PPP_VJC);
|
|
gen_or(b0, b1);
|
|
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, PPP_VJNC);
|
|
gen_or(b1, b0);
|
|
return b0;
|
|
|
|
default:
|
|
proto = ethertype_to_ppptype(proto);
|
|
return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H,
|
|
(bpf_int32)proto);
|
|
}
|
|
/*NOTREACHED*/
|
|
|
|
case DLT_NULL:
|
|
case DLT_LOOP:
|
|
case DLT_ENC:
|
|
switch (proto) {
|
|
|
|
case ETHERTYPE_IP:
|
|
return (gen_loopback_linktype(cstate, AF_INET));
|
|
|
|
case ETHERTYPE_IPV6:
|
|
/*
|
|
* AF_ values may, unfortunately, be platform-
|
|
* dependent; AF_INET isn't, because everybody
|
|
* used 4.2BSD's value, but AF_INET6 is, because
|
|
* 4.2BSD didn't have a value for it (given that
|
|
* IPv6 didn't exist back in the early 1980's),
|
|
* and they all picked their own values.
|
|
*
|
|
* This means that, if we're reading from a
|
|
* savefile, we need to check for all the
|
|
* possible values.
|
|
*
|
|
* If we're doing a live capture, we only need
|
|
* to check for this platform's value; however,
|
|
* Npcap uses 24, which isn't Windows's AF_INET6
|
|
* value. (Given the multiple different values,
|
|
* programs that read pcap files shouldn't be
|
|
* checking for their platform's AF_INET6 value
|
|
* anyway, they should check for all of the
|
|
* possible values. and they might as well do
|
|
* that even for live captures.)
|
|
*/
|
|
if (cstate->bpf_pcap->rfile != NULL) {
|
|
/*
|
|
* Savefile - check for all three
|
|
* possible IPv6 values.
|
|
*/
|
|
b0 = gen_loopback_linktype(cstate, BSD_AFNUM_INET6_BSD);
|
|
b1 = gen_loopback_linktype(cstate, BSD_AFNUM_INET6_FREEBSD);
|
|
gen_or(b0, b1);
|
|
b0 = gen_loopback_linktype(cstate, BSD_AFNUM_INET6_DARWIN);
|
|
gen_or(b0, b1);
|
|
return (b1);
|
|
} else {
|
|
/*
|
|
* Live capture, so we only need to
|
|
* check for the value used on this
|
|
* platform.
|
|
*/
|
|
#ifdef _WIN32
|
|
/*
|
|
* Npcap doesn't use Windows's AF_INET6,
|
|
* as that collides with AF_IPX on
|
|
* some BSDs (both have the value 23).
|
|
* Instead, it uses 24.
|
|
*/
|
|
return (gen_loopback_linktype(cstate, 24));
|
|
#else /* _WIN32 */
|
|
#ifdef AF_INET6
|
|
return (gen_loopback_linktype(cstate, AF_INET6));
|
|
#else /* AF_INET6 */
|
|
/*
|
|
* I guess this platform doesn't support
|
|
* IPv6, so we just reject all packets.
|
|
*/
|
|
return gen_false(cstate);
|
|
#endif /* AF_INET6 */
|
|
#endif /* _WIN32 */
|
|
}
|
|
|
|
default:
|
|
/*
|
|
* Not a type on which we support filtering.
|
|
* XXX - support those that have AF_ values
|
|
* #defined on this platform, at least?
|
|
*/
|
|
return gen_false(cstate);
|
|
}
|
|
|
|
#ifdef HAVE_NET_PFVAR_H
|
|
case DLT_PFLOG:
|
|
/*
|
|
* af field is host byte order in contrast to the rest of
|
|
* the packet.
|
|
*/
|
|
if (proto == ETHERTYPE_IP)
|
|
return (gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, af),
|
|
BPF_B, (bpf_int32)AF_INET));
|
|
else if (proto == ETHERTYPE_IPV6)
|
|
return (gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, af),
|
|
BPF_B, (bpf_int32)AF_INET6));
|
|
else
|
|
return gen_false(cstate);
|
|
/*NOTREACHED*/
|
|
#endif /* HAVE_NET_PFVAR_H */
|
|
|
|
case DLT_ARCNET:
|
|
case DLT_ARCNET_LINUX:
|
|
/*
|
|
* XXX should we check for first fragment if the protocol
|
|
* uses PHDS?
|
|
*/
|
|
switch (proto) {
|
|
|
|
default:
|
|
return gen_false(cstate);
|
|
|
|
case ETHERTYPE_IPV6:
|
|
return (gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
|
|
(bpf_int32)ARCTYPE_INET6));
|
|
|
|
case ETHERTYPE_IP:
|
|
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
|
|
(bpf_int32)ARCTYPE_IP);
|
|
b1 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
|
|
(bpf_int32)ARCTYPE_IP_OLD);
|
|
gen_or(b0, b1);
|
|
return (b1);
|
|
|
|
case ETHERTYPE_ARP:
|
|
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
|
|
(bpf_int32)ARCTYPE_ARP);
|
|
b1 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
|
|
(bpf_int32)ARCTYPE_ARP_OLD);
|
|
gen_or(b0, b1);
|
|
return (b1);
|
|
|
|
case ETHERTYPE_REVARP:
|
|
return (gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
|
|
(bpf_int32)ARCTYPE_REVARP));
|
|
|
|
case ETHERTYPE_ATALK:
|
|
return (gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
|
|
(bpf_int32)ARCTYPE_ATALK));
|
|
}
|
|
/*NOTREACHED*/
|
|
|
|
case DLT_LTALK:
|
|
switch (proto) {
|
|
case ETHERTYPE_ATALK:
|
|
return gen_true(cstate);
|
|
default:
|
|
return gen_false(cstate);
|
|
}
|
|
/*NOTREACHED*/
|
|
|
|
case DLT_FRELAY:
|
|
/*
|
|
* XXX - assumes a 2-byte Frame Relay header with
|
|
* DLCI and flags. What if the address is longer?
|
|
*/
|
|
switch (proto) {
|
|
|
|
case ETHERTYPE_IP:
|
|
/*
|
|
* Check for the special NLPID for IP.
|
|
*/
|
|
return gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | 0xcc);
|
|
|
|
case ETHERTYPE_IPV6:
|
|
/*
|
|
* Check for the special NLPID for IPv6.
|
|
*/
|
|
return gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | 0x8e);
|
|
|
|
case LLCSAP_ISONS:
|
|
/*
|
|
* Check for several OSI protocols.
|
|
*
|
|
* Frame Relay packets typically have an OSI
|
|
* NLPID at the beginning; we check for each
|
|
* of them.
|
|
*
|
|
* What we check for is the NLPID and a frame
|
|
* control field of UI, i.e. 0x03 followed
|
|
* by the NLPID.
|
|
*/
|
|
b0 = gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | ISO8473_CLNP);
|
|
b1 = gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | ISO9542_ESIS);
|
|
b2 = gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | ISO10589_ISIS);
|
|
gen_or(b1, b2);
|
|
gen_or(b0, b2);
|
|
return b2;
|
|
|
|
default:
|
|
return gen_false(cstate);
|
|
}
|
|
/*NOTREACHED*/
|
|
|
|
case DLT_MFR:
|
|
bpf_error(cstate, "Multi-link Frame Relay link-layer type filtering not implemented");
|
|
|
|
case DLT_JUNIPER_MFR:
|
|
case DLT_JUNIPER_MLFR:
|
|
case DLT_JUNIPER_MLPPP:
|
|
case DLT_JUNIPER_ATM1:
|
|
case DLT_JUNIPER_ATM2:
|
|
case DLT_JUNIPER_PPPOE:
|
|
case DLT_JUNIPER_PPPOE_ATM:
|
|
case DLT_JUNIPER_GGSN:
|
|
case DLT_JUNIPER_ES:
|
|
case DLT_JUNIPER_MONITOR:
|
|
case DLT_JUNIPER_SERVICES:
|
|
case DLT_JUNIPER_ETHER:
|
|
case DLT_JUNIPER_PPP:
|
|
case DLT_JUNIPER_FRELAY:
|
|
case DLT_JUNIPER_CHDLC:
|
|
case DLT_JUNIPER_VP:
|
|
case DLT_JUNIPER_ST:
|
|
case DLT_JUNIPER_ISM:
|
|
case DLT_JUNIPER_VS:
|
|
case DLT_JUNIPER_SRX_E2E:
|
|
case DLT_JUNIPER_FIBRECHANNEL:
|
|
case DLT_JUNIPER_ATM_CEMIC:
|
|
|
|
/* just lets verify the magic number for now -
|
|
* on ATM we may have up to 6 different encapsulations on the wire
|
|
* and need a lot of heuristics to figure out that the payload
|
|
* might be;
|
|
*
|
|
* FIXME encapsulation specific BPF_ filters
|
|
*/
|
|
return gen_mcmp(cstate, OR_LINKHDR, 0, BPF_W, 0x4d474300, 0xffffff00); /* compare the magic number */
|
|
|
|
case DLT_BACNET_MS_TP:
|
|
return gen_mcmp(cstate, OR_LINKHDR, 0, BPF_W, 0x55FF0000, 0xffff0000);
|
|
|
|
case DLT_IPNET:
|
|
return gen_ipnet_linktype(cstate, proto);
|
|
|
|
case DLT_LINUX_IRDA:
|
|
bpf_error(cstate, "IrDA link-layer type filtering not implemented");
|
|
|
|
case DLT_DOCSIS:
|
|
bpf_error(cstate, "DOCSIS link-layer type filtering not implemented");
|
|
|
|
case DLT_MTP2:
|
|
case DLT_MTP2_WITH_PHDR:
|
|
bpf_error(cstate, "MTP2 link-layer type filtering not implemented");
|
|
|
|
case DLT_ERF:
|
|
bpf_error(cstate, "ERF link-layer type filtering not implemented");
|
|
|
|
case DLT_PFSYNC:
|
|
bpf_error(cstate, "PFSYNC link-layer type filtering not implemented");
|
|
|
|
case DLT_LINUX_LAPD:
|
|
bpf_error(cstate, "LAPD link-layer type filtering not implemented");
|
|
|
|
case DLT_USB_FREEBSD:
|
|
case DLT_USB_LINUX:
|
|
case DLT_USB_LINUX_MMAPPED:
|
|
case DLT_USBPCAP:
|
|
bpf_error(cstate, "USB link-layer type filtering not implemented");
|
|
|
|
case DLT_BLUETOOTH_HCI_H4:
|
|
case DLT_BLUETOOTH_HCI_H4_WITH_PHDR:
|
|
bpf_error(cstate, "Bluetooth link-layer type filtering not implemented");
|
|
|
|
case DLT_CAN20B:
|
|
case DLT_CAN_SOCKETCAN:
|
|
bpf_error(cstate, "CAN link-layer type filtering not implemented");
|
|
|
|
case DLT_IEEE802_15_4:
|
|
case DLT_IEEE802_15_4_LINUX:
|
|
case DLT_IEEE802_15_4_NONASK_PHY:
|
|
case DLT_IEEE802_15_4_NOFCS:
|
|
bpf_error(cstate, "IEEE 802.15.4 link-layer type filtering not implemented");
|
|
|
|
case DLT_IEEE802_16_MAC_CPS_RADIO:
|
|
bpf_error(cstate, "IEEE 802.16 link-layer type filtering not implemented");
|
|
|
|
case DLT_SITA:
|
|
bpf_error(cstate, "SITA link-layer type filtering not implemented");
|
|
|
|
case DLT_RAIF1:
|
|
bpf_error(cstate, "RAIF1 link-layer type filtering not implemented");
|
|
|
|
case DLT_IPMB_KONTRON:
|
|
case DLT_IPMB_LINUX:
|
|
bpf_error(cstate, "IPMB link-layer type filtering not implemented");
|
|
|
|
case DLT_AX25_KISS:
|
|
bpf_error(cstate, "AX.25 link-layer type filtering not implemented");
|
|
|
|
case DLT_NFLOG:
|
|
/* Using the fixed-size NFLOG header it is possible to tell only
|
|
* the address family of the packet, other meaningful data is
|
|
* either missing or behind TLVs.
|
|
*/
|
|
bpf_error(cstate, "NFLOG link-layer type filtering not implemented");
|
|
|
|
default:
|
|
/*
|
|
* Does this link-layer header type have a field
|
|
* indicating the type of the next protocol? If
|
|
* so, off_linktype.constant_part will be the offset of that
|
|
* field in the packet; if not, it will be OFFSET_NOT_SET.
|
|
*/
|
|
if (cstate->off_linktype.constant_part != OFFSET_NOT_SET) {
|
|
/*
|
|
* Yes; assume it's an Ethernet type. (If
|
|
* it's not, it needs to be handled specially
|
|
* above.)
|
|
*/
|
|
return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
|
|
/*NOTREACHED */
|
|
} else {
|
|
/*
|
|
* No; report an error.
|
|
*/
|
|
description = pcap_datalink_val_to_description_or_dlt(cstate->linktype);
|
|
bpf_error(cstate, "%s link-layer type filtering not implemented",
|
|
description);
|
|
/*NOTREACHED */
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Check for an LLC SNAP packet with a given organization code and
|
|
* protocol type; we check the entire contents of the 802.2 LLC and
|
|
* snap headers, checking for DSAP and SSAP of SNAP and a control
|
|
* field of 0x03 in the LLC header, and for the specified organization
|
|
* code and protocol type in the SNAP header.
|
|
*/
|
|
static struct block *
|
|
gen_snap(compiler_state_t *cstate, bpf_u_int32 orgcode, bpf_u_int32 ptype)
|
|
{
|
|
u_char snapblock[8];
|
|
|
|
snapblock[0] = LLCSAP_SNAP; /* DSAP = SNAP */
|
|
snapblock[1] = LLCSAP_SNAP; /* SSAP = SNAP */
|
|
snapblock[2] = 0x03; /* control = UI */
|
|
snapblock[3] = (u_char)(orgcode >> 16); /* upper 8 bits of organization code */
|
|
snapblock[4] = (u_char)(orgcode >> 8); /* middle 8 bits of organization code */
|
|
snapblock[5] = (u_char)(orgcode >> 0); /* lower 8 bits of organization code */
|
|
snapblock[6] = (u_char)(ptype >> 8); /* upper 8 bits of protocol type */
|
|
snapblock[7] = (u_char)(ptype >> 0); /* lower 8 bits of protocol type */
|
|
return gen_bcmp(cstate, OR_LLC, 0, 8, snapblock);
|
|
}
|
|
|
|
/*
|
|
* Generate code to match frames with an LLC header.
|
|
*/
|
|
static struct block *
|
|
gen_llc_internal(compiler_state_t *cstate)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
switch (cstate->linktype) {
|
|
|
|
case DLT_EN10MB:
|
|
/*
|
|
* We check for an Ethernet type field less than
|
|
* 1500, which means it's an 802.3 length field.
|
|
*/
|
|
b0 = gen_cmp_gt(cstate, OR_LINKTYPE, 0, BPF_H, ETHERMTU);
|
|
gen_not(b0);
|
|
|
|
/*
|
|
* Now check for the purported DSAP and SSAP not being
|
|
* 0xFF, to rule out NetWare-over-802.3.
|
|
*/
|
|
b1 = gen_cmp(cstate, OR_LLC, 0, BPF_H, (bpf_int32)0xFFFF);
|
|
gen_not(b1);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case DLT_SUNATM:
|
|
/*
|
|
* We check for LLC traffic.
|
|
*/
|
|
b0 = gen_atmtype_llc(cstate);
|
|
return b0;
|
|
|
|
case DLT_IEEE802: /* Token Ring */
|
|
/*
|
|
* XXX - check for LLC frames.
|
|
*/
|
|
return gen_true(cstate);
|
|
|
|
case DLT_FDDI:
|
|
/*
|
|
* XXX - check for LLC frames.
|
|
*/
|
|
return gen_true(cstate);
|
|
|
|
case DLT_ATM_RFC1483:
|
|
/*
|
|
* For LLC encapsulation, these are defined to have an
|
|
* 802.2 LLC header.
|
|
*
|
|
* For VC encapsulation, they don't, but there's no
|
|
* way to check for that; the protocol used on the VC
|
|
* is negotiated out of band.
|
|
*/
|
|
return gen_true(cstate);
|
|
|
|
case DLT_IEEE802_11:
|
|
case DLT_PRISM_HEADER:
|
|
case DLT_IEEE802_11_RADIO:
|
|
case DLT_IEEE802_11_RADIO_AVS:
|
|
case DLT_PPI:
|
|
/*
|
|
* Check that we have a data frame.
|
|
*/
|
|
b0 = gen_check_802_11_data_frame(cstate);
|
|
return b0;
|
|
|
|
default:
|
|
bpf_error(cstate, "'llc' not supported for %s",
|
|
pcap_datalink_val_to_description_or_dlt(cstate->linktype));
|
|
/*NOTREACHED*/
|
|
}
|
|
}
|
|
|
|
struct block *
|
|
gen_llc(compiler_state_t *cstate)
|
|
{
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
return gen_llc_internal(cstate);
|
|
}
|
|
|
|
struct block *
|
|
gen_llc_i(compiler_state_t *cstate)
|
|
{
|
|
struct block *b0, *b1;
|
|
struct slist *s;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
/*
|
|
* Check whether this is an LLC frame.
|
|
*/
|
|
b0 = gen_llc_internal(cstate);
|
|
|
|
/*
|
|
* Load the control byte and test the low-order bit; it must
|
|
* be clear for I frames.
|
|
*/
|
|
s = gen_load_a(cstate, OR_LLC, 2, BPF_B);
|
|
b1 = new_block(cstate, JMP(BPF_JSET));
|
|
b1->s.k = 0x01;
|
|
b1->stmts = s;
|
|
gen_not(b1);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
|
|
struct block *
|
|
gen_llc_s(compiler_state_t *cstate)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
/*
|
|
* Check whether this is an LLC frame.
|
|
*/
|
|
b0 = gen_llc_internal(cstate);
|
|
|
|
/*
|
|
* Now compare the low-order 2 bit of the control byte against
|
|
* the appropriate value for S frames.
|
|
*/
|
|
b1 = gen_mcmp(cstate, OR_LLC, 2, BPF_B, LLC_S_FMT, 0x03);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
|
|
struct block *
|
|
gen_llc_u(compiler_state_t *cstate)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
/*
|
|
* Check whether this is an LLC frame.
|
|
*/
|
|
b0 = gen_llc_internal(cstate);
|
|
|
|
/*
|
|
* Now compare the low-order 2 bit of the control byte against
|
|
* the appropriate value for U frames.
|
|
*/
|
|
b1 = gen_mcmp(cstate, OR_LLC, 2, BPF_B, LLC_U_FMT, 0x03);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
|
|
struct block *
|
|
gen_llc_s_subtype(compiler_state_t *cstate, bpf_u_int32 subtype)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
/*
|
|
* Check whether this is an LLC frame.
|
|
*/
|
|
b0 = gen_llc_internal(cstate);
|
|
|
|
/*
|
|
* Now check for an S frame with the appropriate type.
|
|
*/
|
|
b1 = gen_mcmp(cstate, OR_LLC, 2, BPF_B, subtype, LLC_S_CMD_MASK);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
|
|
struct block *
|
|
gen_llc_u_subtype(compiler_state_t *cstate, bpf_u_int32 subtype)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
/*
|
|
* Check whether this is an LLC frame.
|
|
*/
|
|
b0 = gen_llc_internal(cstate);
|
|
|
|
/*
|
|
* Now check for a U frame with the appropriate type.
|
|
*/
|
|
b1 = gen_mcmp(cstate, OR_LLC, 2, BPF_B, subtype, LLC_U_CMD_MASK);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
|
|
/*
|
|
* Generate code to match a particular packet type, for link-layer types
|
|
* using 802.2 LLC headers.
|
|
*
|
|
* This is *NOT* used for Ethernet; "gen_ether_linktype()" is used
|
|
* for that - it handles the D/I/X Ethernet vs. 802.3+802.2 issues.
|
|
*
|
|
* "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
|
|
* value, if <= ETHERMTU. We use that to determine whether to
|
|
* match the DSAP or both DSAP and LSAP or to check the OUI and
|
|
* protocol ID in a SNAP header.
|
|
*/
|
|
static struct block *
|
|
gen_llc_linktype(compiler_state_t *cstate, int proto)
|
|
{
|
|
/*
|
|
* XXX - handle token-ring variable-length header.
|
|
*/
|
|
switch (proto) {
|
|
|
|
case LLCSAP_IP:
|
|
case LLCSAP_ISONS:
|
|
case LLCSAP_NETBEUI:
|
|
/*
|
|
* XXX - should we check both the DSAP and the
|
|
* SSAP, like this, or should we check just the
|
|
* DSAP, as we do for other SAP values?
|
|
*/
|
|
return gen_cmp(cstate, OR_LLC, 0, BPF_H, (bpf_u_int32)
|
|
((proto << 8) | proto));
|
|
|
|
case LLCSAP_IPX:
|
|
/*
|
|
* XXX - are there ever SNAP frames for IPX on
|
|
* non-Ethernet 802.x networks?
|
|
*/
|
|
return gen_cmp(cstate, OR_LLC, 0, BPF_B,
|
|
(bpf_int32)LLCSAP_IPX);
|
|
|
|
case ETHERTYPE_ATALK:
|
|
/*
|
|
* 802.2-encapsulated ETHERTYPE_ATALK packets are
|
|
* SNAP packets with an organization code of
|
|
* 0x080007 (Apple, for Appletalk) and a protocol
|
|
* type of ETHERTYPE_ATALK (Appletalk).
|
|
*
|
|
* XXX - check for an organization code of
|
|
* encapsulated Ethernet as well?
|
|
*/
|
|
return gen_snap(cstate, 0x080007, ETHERTYPE_ATALK);
|
|
|
|
default:
|
|
/*
|
|
* XXX - we don't have to check for IPX 802.3
|
|
* here, but should we check for the IPX Ethertype?
|
|
*/
|
|
if (proto <= ETHERMTU) {
|
|
/*
|
|
* This is an LLC SAP value, so check
|
|
* the DSAP.
|
|
*/
|
|
return gen_cmp(cstate, OR_LLC, 0, BPF_B, (bpf_int32)proto);
|
|
} else {
|
|
/*
|
|
* This is an Ethernet type; we assume that it's
|
|
* unlikely that it'll appear in the right place
|
|
* at random, and therefore check only the
|
|
* location that would hold the Ethernet type
|
|
* in a SNAP frame with an organization code of
|
|
* 0x000000 (encapsulated Ethernet).
|
|
*
|
|
* XXX - if we were to check for the SNAP DSAP and
|
|
* LSAP, as per XXX, and were also to check for an
|
|
* organization code of 0x000000 (encapsulated
|
|
* Ethernet), we'd do
|
|
*
|
|
* return gen_snap(cstate, 0x000000, proto);
|
|
*
|
|
* here; for now, we don't, as per the above.
|
|
* I don't know whether it's worth the extra CPU
|
|
* time to do the right check or not.
|
|
*/
|
|
return gen_cmp(cstate, OR_LLC, 6, BPF_H, (bpf_int32)proto);
|
|
}
|
|
}
|
|
}
|
|
|
|
static struct block *
|
|
gen_hostop(compiler_state_t *cstate, bpf_u_int32 addr, bpf_u_int32 mask,
|
|
int dir, int proto, u_int src_off, u_int dst_off)
|
|
{
|
|
struct block *b0, *b1;
|
|
u_int offset;
|
|
|
|
switch (dir) {
|
|
|
|
case Q_SRC:
|
|
offset = src_off;
|
|
break;
|
|
|
|
case Q_DST:
|
|
offset = dst_off;
|
|
break;
|
|
|
|
case Q_AND:
|
|
b0 = gen_hostop(cstate, addr, mask, Q_SRC, proto, src_off, dst_off);
|
|
b1 = gen_hostop(cstate, addr, mask, Q_DST, proto, src_off, dst_off);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case Q_DEFAULT:
|
|
case Q_OR:
|
|
b0 = gen_hostop(cstate, addr, mask, Q_SRC, proto, src_off, dst_off);
|
|
b1 = gen_hostop(cstate, addr, mask, Q_DST, proto, src_off, dst_off);
|
|
gen_or(b0, b1);
|
|
return b1;
|
|
|
|
case Q_ADDR1:
|
|
bpf_error(cstate, "'addr1' and 'address1' are not valid qualifiers for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR2:
|
|
bpf_error(cstate, "'addr2' and 'address2' are not valid qualifiers for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR3:
|
|
bpf_error(cstate, "'addr3' and 'address3' are not valid qualifiers for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR4:
|
|
bpf_error(cstate, "'addr4' and 'address4' are not valid qualifiers for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_RA:
|
|
bpf_error(cstate, "'ra' is not a valid qualifier for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_TA:
|
|
bpf_error(cstate, "'ta' is not a valid qualifier for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
default:
|
|
abort();
|
|
/*NOTREACHED*/
|
|
}
|
|
b0 = gen_linktype(cstate, proto);
|
|
b1 = gen_mcmp(cstate, OR_LINKPL, offset, BPF_W, (bpf_int32)addr, mask);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
|
|
#ifdef INET6
|
|
static struct block *
|
|
gen_hostop6(compiler_state_t *cstate, struct in6_addr *addr,
|
|
struct in6_addr *mask, int dir, int proto, u_int src_off, u_int dst_off)
|
|
{
|
|
struct block *b0, *b1;
|
|
u_int offset;
|
|
uint32_t *a, *m;
|
|
|
|
switch (dir) {
|
|
|
|
case Q_SRC:
|
|
offset = src_off;
|
|
break;
|
|
|
|
case Q_DST:
|
|
offset = dst_off;
|
|
break;
|
|
|
|
case Q_AND:
|
|
b0 = gen_hostop6(cstate, addr, mask, Q_SRC, proto, src_off, dst_off);
|
|
b1 = gen_hostop6(cstate, addr, mask, Q_DST, proto, src_off, dst_off);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case Q_DEFAULT:
|
|
case Q_OR:
|
|
b0 = gen_hostop6(cstate, addr, mask, Q_SRC, proto, src_off, dst_off);
|
|
b1 = gen_hostop6(cstate, addr, mask, Q_DST, proto, src_off, dst_off);
|
|
gen_or(b0, b1);
|
|
return b1;
|
|
|
|
case Q_ADDR1:
|
|
bpf_error(cstate, "'addr1' and 'address1' are not valid qualifiers for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR2:
|
|
bpf_error(cstate, "'addr2' and 'address2' are not valid qualifiers for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR3:
|
|
bpf_error(cstate, "'addr3' and 'address3' are not valid qualifiers for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR4:
|
|
bpf_error(cstate, "'addr4' and 'address4' are not valid qualifiers for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_RA:
|
|
bpf_error(cstate, "'ra' is not a valid qualifier for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_TA:
|
|
bpf_error(cstate, "'ta' is not a valid qualifier for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
default:
|
|
abort();
|
|
/*NOTREACHED*/
|
|
}
|
|
/* this order is important */
|
|
a = (uint32_t *)addr;
|
|
m = (uint32_t *)mask;
|
|
b1 = gen_mcmp(cstate, OR_LINKPL, offset + 12, BPF_W, ntohl(a[3]), ntohl(m[3]));
|
|
b0 = gen_mcmp(cstate, OR_LINKPL, offset + 8, BPF_W, ntohl(a[2]), ntohl(m[2]));
|
|
gen_and(b0, b1);
|
|
b0 = gen_mcmp(cstate, OR_LINKPL, offset + 4, BPF_W, ntohl(a[1]), ntohl(m[1]));
|
|
gen_and(b0, b1);
|
|
b0 = gen_mcmp(cstate, OR_LINKPL, offset + 0, BPF_W, ntohl(a[0]), ntohl(m[0]));
|
|
gen_and(b0, b1);
|
|
b0 = gen_linktype(cstate, proto);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
#endif
|
|
|
|
static struct block *
|
|
gen_ehostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
|
|
{
|
|
register struct block *b0, *b1;
|
|
|
|
switch (dir) {
|
|
case Q_SRC:
|
|
return gen_bcmp(cstate, OR_LINKHDR, 6, 6, eaddr);
|
|
|
|
case Q_DST:
|
|
return gen_bcmp(cstate, OR_LINKHDR, 0, 6, eaddr);
|
|
|
|
case Q_AND:
|
|
b0 = gen_ehostop(cstate, eaddr, Q_SRC);
|
|
b1 = gen_ehostop(cstate, eaddr, Q_DST);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case Q_DEFAULT:
|
|
case Q_OR:
|
|
b0 = gen_ehostop(cstate, eaddr, Q_SRC);
|
|
b1 = gen_ehostop(cstate, eaddr, Q_DST);
|
|
gen_or(b0, b1);
|
|
return b1;
|
|
|
|
case Q_ADDR1:
|
|
bpf_error(cstate, "'addr1' and 'address1' are only supported on 802.11 with 802.11 headers");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR2:
|
|
bpf_error(cstate, "'addr2' and 'address2' are only supported on 802.11 with 802.11 headers");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR3:
|
|
bpf_error(cstate, "'addr3' and 'address3' are only supported on 802.11 with 802.11 headers");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR4:
|
|
bpf_error(cstate, "'addr4' and 'address4' are only supported on 802.11 with 802.11 headers");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_RA:
|
|
bpf_error(cstate, "'ra' is only supported on 802.11 with 802.11 headers");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_TA:
|
|
bpf_error(cstate, "'ta' is only supported on 802.11 with 802.11 headers");
|
|
/*NOTREACHED*/
|
|
}
|
|
abort();
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
/*
|
|
* Like gen_ehostop, but for DLT_FDDI
|
|
*/
|
|
static struct block *
|
|
gen_fhostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
switch (dir) {
|
|
case Q_SRC:
|
|
return gen_bcmp(cstate, OR_LINKHDR, 6 + 1 + cstate->pcap_fddipad, 6, eaddr);
|
|
|
|
case Q_DST:
|
|
return gen_bcmp(cstate, OR_LINKHDR, 0 + 1 + cstate->pcap_fddipad, 6, eaddr);
|
|
|
|
case Q_AND:
|
|
b0 = gen_fhostop(cstate, eaddr, Q_SRC);
|
|
b1 = gen_fhostop(cstate, eaddr, Q_DST);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case Q_DEFAULT:
|
|
case Q_OR:
|
|
b0 = gen_fhostop(cstate, eaddr, Q_SRC);
|
|
b1 = gen_fhostop(cstate, eaddr, Q_DST);
|
|
gen_or(b0, b1);
|
|
return b1;
|
|
|
|
case Q_ADDR1:
|
|
bpf_error(cstate, "'addr1' and 'address1' are only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR2:
|
|
bpf_error(cstate, "'addr2' and 'address2' are only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR3:
|
|
bpf_error(cstate, "'addr3' and 'address3' are only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR4:
|
|
bpf_error(cstate, "'addr4' and 'address4' are only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_RA:
|
|
bpf_error(cstate, "'ra' is only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_TA:
|
|
bpf_error(cstate, "'ta' is only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
}
|
|
abort();
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
/*
|
|
* Like gen_ehostop, but for DLT_IEEE802 (Token Ring)
|
|
*/
|
|
static struct block *
|
|
gen_thostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
|
|
{
|
|
register struct block *b0, *b1;
|
|
|
|
switch (dir) {
|
|
case Q_SRC:
|
|
return gen_bcmp(cstate, OR_LINKHDR, 8, 6, eaddr);
|
|
|
|
case Q_DST:
|
|
return gen_bcmp(cstate, OR_LINKHDR, 2, 6, eaddr);
|
|
|
|
case Q_AND:
|
|
b0 = gen_thostop(cstate, eaddr, Q_SRC);
|
|
b1 = gen_thostop(cstate, eaddr, Q_DST);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case Q_DEFAULT:
|
|
case Q_OR:
|
|
b0 = gen_thostop(cstate, eaddr, Q_SRC);
|
|
b1 = gen_thostop(cstate, eaddr, Q_DST);
|
|
gen_or(b0, b1);
|
|
return b1;
|
|
|
|
case Q_ADDR1:
|
|
bpf_error(cstate, "'addr1' and 'address1' are only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR2:
|
|
bpf_error(cstate, "'addr2' and 'address2' are only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR3:
|
|
bpf_error(cstate, "'addr3' and 'address3' are only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR4:
|
|
bpf_error(cstate, "'addr4' and 'address4' are only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_RA:
|
|
bpf_error(cstate, "'ra' is only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_TA:
|
|
bpf_error(cstate, "'ta' is only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
}
|
|
abort();
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
/*
|
|
* Like gen_ehostop, but for DLT_IEEE802_11 (802.11 wireless LAN) and
|
|
* various 802.11 + radio headers.
|
|
*/
|
|
static struct block *
|
|
gen_wlanhostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
|
|
{
|
|
register struct block *b0, *b1, *b2;
|
|
register struct slist *s;
|
|
|
|
#ifdef ENABLE_WLAN_FILTERING_PATCH
|
|
/*
|
|
* TODO GV 20070613
|
|
* We need to disable the optimizer because the optimizer is buggy
|
|
* and wipes out some LD instructions generated by the below
|
|
* code to validate the Frame Control bits
|
|
*/
|
|
cstate->no_optimize = 1;
|
|
#endif /* ENABLE_WLAN_FILTERING_PATCH */
|
|
|
|
switch (dir) {
|
|
case Q_SRC:
|
|
/*
|
|
* Oh, yuk.
|
|
*
|
|
* For control frames, there is no SA.
|
|
*
|
|
* For management frames, SA is at an
|
|
* offset of 10 from the beginning of
|
|
* the packet.
|
|
*
|
|
* For data frames, SA is at an offset
|
|
* of 10 from the beginning of the packet
|
|
* if From DS is clear, at an offset of
|
|
* 16 from the beginning of the packet
|
|
* if From DS is set and To DS is clear,
|
|
* and an offset of 24 from the beginning
|
|
* of the packet if From DS is set and To DS
|
|
* is set.
|
|
*/
|
|
|
|
/*
|
|
* Generate the tests to be done for data frames
|
|
* with From DS set.
|
|
*
|
|
* First, check for To DS set, i.e. check "link[1] & 0x01".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B);
|
|
b1 = new_block(cstate, JMP(BPF_JSET));
|
|
b1->s.k = 0x01; /* To DS */
|
|
b1->stmts = s;
|
|
|
|
/*
|
|
* If To DS is set, the SA is at 24.
|
|
*/
|
|
b0 = gen_bcmp(cstate, OR_LINKHDR, 24, 6, eaddr);
|
|
gen_and(b1, b0);
|
|
|
|
/*
|
|
* Now, check for To DS not set, i.e. check
|
|
* "!(link[1] & 0x01)".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B);
|
|
b2 = new_block(cstate, JMP(BPF_JSET));
|
|
b2->s.k = 0x01; /* To DS */
|
|
b2->stmts = s;
|
|
gen_not(b2);
|
|
|
|
/*
|
|
* If To DS is not set, the SA is at 16.
|
|
*/
|
|
b1 = gen_bcmp(cstate, OR_LINKHDR, 16, 6, eaddr);
|
|
gen_and(b2, b1);
|
|
|
|
/*
|
|
* Now OR together the last two checks. That gives
|
|
* the complete set of checks for data frames with
|
|
* From DS set.
|
|
*/
|
|
gen_or(b1, b0);
|
|
|
|
/*
|
|
* Now check for From DS being set, and AND that with
|
|
* the ORed-together checks.
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B);
|
|
b1 = new_block(cstate, JMP(BPF_JSET));
|
|
b1->s.k = 0x02; /* From DS */
|
|
b1->stmts = s;
|
|
gen_and(b1, b0);
|
|
|
|
/*
|
|
* Now check for data frames with From DS not set.
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B);
|
|
b2 = new_block(cstate, JMP(BPF_JSET));
|
|
b2->s.k = 0x02; /* From DS */
|
|
b2->stmts = s;
|
|
gen_not(b2);
|
|
|
|
/*
|
|
* If From DS isn't set, the SA is at 10.
|
|
*/
|
|
b1 = gen_bcmp(cstate, OR_LINKHDR, 10, 6, eaddr);
|
|
gen_and(b2, b1);
|
|
|
|
/*
|
|
* Now OR together the checks for data frames with
|
|
* From DS not set and for data frames with From DS
|
|
* set; that gives the checks done for data frames.
|
|
*/
|
|
gen_or(b1, b0);
|
|
|
|
/*
|
|
* Now check for a data frame.
|
|
* I.e, check "link[0] & 0x08".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
|
|
b1 = new_block(cstate, JMP(BPF_JSET));
|
|
b1->s.k = 0x08;
|
|
b1->stmts = s;
|
|
|
|
/*
|
|
* AND that with the checks done for data frames.
|
|
*/
|
|
gen_and(b1, b0);
|
|
|
|
/*
|
|
* If the high-order bit of the type value is 0, this
|
|
* is a management frame.
|
|
* I.e, check "!(link[0] & 0x08)".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
|
|
b2 = new_block(cstate, JMP(BPF_JSET));
|
|
b2->s.k = 0x08;
|
|
b2->stmts = s;
|
|
gen_not(b2);
|
|
|
|
/*
|
|
* For management frames, the SA is at 10.
|
|
*/
|
|
b1 = gen_bcmp(cstate, OR_LINKHDR, 10, 6, eaddr);
|
|
gen_and(b2, b1);
|
|
|
|
/*
|
|
* OR that with the checks done for data frames.
|
|
* That gives the checks done for management and
|
|
* data frames.
|
|
*/
|
|
gen_or(b1, b0);
|
|
|
|
/*
|
|
* If the low-order bit of the type value is 1,
|
|
* this is either a control frame or a frame
|
|
* with a reserved type, and thus not a
|
|
* frame with an SA.
|
|
*
|
|
* I.e., check "!(link[0] & 0x04)".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
|
|
b1 = new_block(cstate, JMP(BPF_JSET));
|
|
b1->s.k = 0x04;
|
|
b1->stmts = s;
|
|
gen_not(b1);
|
|
|
|
/*
|
|
* AND that with the checks for data and management
|
|
* frames.
|
|
*/
|
|
gen_and(b1, b0);
|
|
return b0;
|
|
|
|
case Q_DST:
|
|
/*
|
|
* Oh, yuk.
|
|
*
|
|
* For control frames, there is no DA.
|
|
*
|
|
* For management frames, DA is at an
|
|
* offset of 4 from the beginning of
|
|
* the packet.
|
|
*
|
|
* For data frames, DA is at an offset
|
|
* of 4 from the beginning of the packet
|
|
* if To DS is clear and at an offset of
|
|
* 16 from the beginning of the packet
|
|
* if To DS is set.
|
|
*/
|
|
|
|
/*
|
|
* Generate the tests to be done for data frames.
|
|
*
|
|
* First, check for To DS set, i.e. "link[1] & 0x01".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B);
|
|
b1 = new_block(cstate, JMP(BPF_JSET));
|
|
b1->s.k = 0x01; /* To DS */
|
|
b1->stmts = s;
|
|
|
|
/*
|
|
* If To DS is set, the DA is at 16.
|
|
*/
|
|
b0 = gen_bcmp(cstate, OR_LINKHDR, 16, 6, eaddr);
|
|
gen_and(b1, b0);
|
|
|
|
/*
|
|
* Now, check for To DS not set, i.e. check
|
|
* "!(link[1] & 0x01)".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B);
|
|
b2 = new_block(cstate, JMP(BPF_JSET));
|
|
b2->s.k = 0x01; /* To DS */
|
|
b2->stmts = s;
|
|
gen_not(b2);
|
|
|
|
/*
|
|
* If To DS is not set, the DA is at 4.
|
|
*/
|
|
b1 = gen_bcmp(cstate, OR_LINKHDR, 4, 6, eaddr);
|
|
gen_and(b2, b1);
|
|
|
|
/*
|
|
* Now OR together the last two checks. That gives
|
|
* the complete set of checks for data frames.
|
|
*/
|
|
gen_or(b1, b0);
|
|
|
|
/*
|
|
* Now check for a data frame.
|
|
* I.e, check "link[0] & 0x08".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
|
|
b1 = new_block(cstate, JMP(BPF_JSET));
|
|
b1->s.k = 0x08;
|
|
b1->stmts = s;
|
|
|
|
/*
|
|
* AND that with the checks done for data frames.
|
|
*/
|
|
gen_and(b1, b0);
|
|
|
|
/*
|
|
* If the high-order bit of the type value is 0, this
|
|
* is a management frame.
|
|
* I.e, check "!(link[0] & 0x08)".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
|
|
b2 = new_block(cstate, JMP(BPF_JSET));
|
|
b2->s.k = 0x08;
|
|
b2->stmts = s;
|
|
gen_not(b2);
|
|
|
|
/*
|
|
* For management frames, the DA is at 4.
|
|
*/
|
|
b1 = gen_bcmp(cstate, OR_LINKHDR, 4, 6, eaddr);
|
|
gen_and(b2, b1);
|
|
|
|
/*
|
|
* OR that with the checks done for data frames.
|
|
* That gives the checks done for management and
|
|
* data frames.
|
|
*/
|
|
gen_or(b1, b0);
|
|
|
|
/*
|
|
* If the low-order bit of the type value is 1,
|
|
* this is either a control frame or a frame
|
|
* with a reserved type, and thus not a
|
|
* frame with an SA.
|
|
*
|
|
* I.e., check "!(link[0] & 0x04)".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
|
|
b1 = new_block(cstate, JMP(BPF_JSET));
|
|
b1->s.k = 0x04;
|
|
b1->stmts = s;
|
|
gen_not(b1);
|
|
|
|
/*
|
|
* AND that with the checks for data and management
|
|
* frames.
|
|
*/
|
|
gen_and(b1, b0);
|
|
return b0;
|
|
|
|
case Q_AND:
|
|
b0 = gen_wlanhostop(cstate, eaddr, Q_SRC);
|
|
b1 = gen_wlanhostop(cstate, eaddr, Q_DST);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case Q_DEFAULT:
|
|
case Q_OR:
|
|
b0 = gen_wlanhostop(cstate, eaddr, Q_SRC);
|
|
b1 = gen_wlanhostop(cstate, eaddr, Q_DST);
|
|
gen_or(b0, b1);
|
|
return b1;
|
|
|
|
/*
|
|
* XXX - add BSSID keyword?
|
|
*/
|
|
case Q_ADDR1:
|
|
return (gen_bcmp(cstate, OR_LINKHDR, 4, 6, eaddr));
|
|
|
|
case Q_ADDR2:
|
|
/*
|
|
* Not present in CTS or ACK control frames.
|
|
*/
|
|
b0 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_TYPE_CTL,
|
|
IEEE80211_FC0_TYPE_MASK);
|
|
gen_not(b0);
|
|
b1 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_SUBTYPE_CTS,
|
|
IEEE80211_FC0_SUBTYPE_MASK);
|
|
gen_not(b1);
|
|
b2 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_SUBTYPE_ACK,
|
|
IEEE80211_FC0_SUBTYPE_MASK);
|
|
gen_not(b2);
|
|
gen_and(b1, b2);
|
|
gen_or(b0, b2);
|
|
b1 = gen_bcmp(cstate, OR_LINKHDR, 10, 6, eaddr);
|
|
gen_and(b2, b1);
|
|
return b1;
|
|
|
|
case Q_ADDR3:
|
|
/*
|
|
* Not present in control frames.
|
|
*/
|
|
b0 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_TYPE_CTL,
|
|
IEEE80211_FC0_TYPE_MASK);
|
|
gen_not(b0);
|
|
b1 = gen_bcmp(cstate, OR_LINKHDR, 16, 6, eaddr);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case Q_ADDR4:
|
|
/*
|
|
* Present only if the direction mask has both "From DS"
|
|
* and "To DS" set. Neither control frames nor management
|
|
* frames should have both of those set, so we don't
|
|
* check the frame type.
|
|
*/
|
|
b0 = gen_mcmp(cstate, OR_LINKHDR, 1, BPF_B,
|
|
IEEE80211_FC1_DIR_DSTODS, IEEE80211_FC1_DIR_MASK);
|
|
b1 = gen_bcmp(cstate, OR_LINKHDR, 24, 6, eaddr);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case Q_RA:
|
|
/*
|
|
* Not present in management frames; addr1 in other
|
|
* frames.
|
|
*/
|
|
|
|
/*
|
|
* If the high-order bit of the type value is 0, this
|
|
* is a management frame.
|
|
* I.e, check "(link[0] & 0x08)".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
|
|
b1 = new_block(cstate, JMP(BPF_JSET));
|
|
b1->s.k = 0x08;
|
|
b1->stmts = s;
|
|
|
|
/*
|
|
* Check addr1.
|
|
*/
|
|
b0 = gen_bcmp(cstate, OR_LINKHDR, 4, 6, eaddr);
|
|
|
|
/*
|
|
* AND that with the check of addr1.
|
|
*/
|
|
gen_and(b1, b0);
|
|
return (b0);
|
|
|
|
case Q_TA:
|
|
/*
|
|
* Not present in management frames; addr2, if present,
|
|
* in other frames.
|
|
*/
|
|
|
|
/*
|
|
* Not present in CTS or ACK control frames.
|
|
*/
|
|
b0 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_TYPE_CTL,
|
|
IEEE80211_FC0_TYPE_MASK);
|
|
gen_not(b0);
|
|
b1 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_SUBTYPE_CTS,
|
|
IEEE80211_FC0_SUBTYPE_MASK);
|
|
gen_not(b1);
|
|
b2 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_SUBTYPE_ACK,
|
|
IEEE80211_FC0_SUBTYPE_MASK);
|
|
gen_not(b2);
|
|
gen_and(b1, b2);
|
|
gen_or(b0, b2);
|
|
|
|
/*
|
|
* If the high-order bit of the type value is 0, this
|
|
* is a management frame.
|
|
* I.e, check "(link[0] & 0x08)".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
|
|
b1 = new_block(cstate, JMP(BPF_JSET));
|
|
b1->s.k = 0x08;
|
|
b1->stmts = s;
|
|
|
|
/*
|
|
* AND that with the check for frames other than
|
|
* CTS and ACK frames.
|
|
*/
|
|
gen_and(b1, b2);
|
|
|
|
/*
|
|
* Check addr2.
|
|
*/
|
|
b1 = gen_bcmp(cstate, OR_LINKHDR, 10, 6, eaddr);
|
|
gen_and(b2, b1);
|
|
return b1;
|
|
}
|
|
abort();
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
/*
|
|
* Like gen_ehostop, but for RFC 2625 IP-over-Fibre-Channel.
|
|
* (We assume that the addresses are IEEE 48-bit MAC addresses,
|
|
* as the RFC states.)
|
|
*/
|
|
static struct block *
|
|
gen_ipfchostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
|
|
{
|
|
register struct block *b0, *b1;
|
|
|
|
switch (dir) {
|
|
case Q_SRC:
|
|
return gen_bcmp(cstate, OR_LINKHDR, 10, 6, eaddr);
|
|
|
|
case Q_DST:
|
|
return gen_bcmp(cstate, OR_LINKHDR, 2, 6, eaddr);
|
|
|
|
case Q_AND:
|
|
b0 = gen_ipfchostop(cstate, eaddr, Q_SRC);
|
|
b1 = gen_ipfchostop(cstate, eaddr, Q_DST);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case Q_DEFAULT:
|
|
case Q_OR:
|
|
b0 = gen_ipfchostop(cstate, eaddr, Q_SRC);
|
|
b1 = gen_ipfchostop(cstate, eaddr, Q_DST);
|
|
gen_or(b0, b1);
|
|
return b1;
|
|
|
|
case Q_ADDR1:
|
|
bpf_error(cstate, "'addr1' and 'address1' are only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR2:
|
|
bpf_error(cstate, "'addr2' and 'address2' are only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR3:
|
|
bpf_error(cstate, "'addr3' and 'address3' are only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR4:
|
|
bpf_error(cstate, "'addr4' and 'address4' are only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_RA:
|
|
bpf_error(cstate, "'ra' is only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_TA:
|
|
bpf_error(cstate, "'ta' is only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
}
|
|
abort();
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
/*
|
|
* This is quite tricky because there may be pad bytes in front of the
|
|
* DECNET header, and then there are two possible data packet formats that
|
|
* carry both src and dst addresses, plus 5 packet types in a format that
|
|
* carries only the src node, plus 2 types that use a different format and
|
|
* also carry just the src node.
|
|
*
|
|
* Yuck.
|
|
*
|
|
* Instead of doing those all right, we just look for data packets with
|
|
* 0 or 1 bytes of padding. If you want to look at other packets, that
|
|
* will require a lot more hacking.
|
|
*
|
|
* To add support for filtering on DECNET "areas" (network numbers)
|
|
* one would want to add a "mask" argument to this routine. That would
|
|
* make the filter even more inefficient, although one could be clever
|
|
* and not generate masking instructions if the mask is 0xFFFF.
|
|
*/
|
|
static struct block *
|
|
gen_dnhostop(compiler_state_t *cstate, bpf_u_int32 addr, int dir)
|
|
{
|
|
struct block *b0, *b1, *b2, *tmp;
|
|
u_int offset_lh; /* offset if long header is received */
|
|
u_int offset_sh; /* offset if short header is received */
|
|
|
|
switch (dir) {
|
|
|
|
case Q_DST:
|
|
offset_sh = 1; /* follows flags */
|
|
offset_lh = 7; /* flgs,darea,dsubarea,HIORD */
|
|
break;
|
|
|
|
case Q_SRC:
|
|
offset_sh = 3; /* follows flags, dstnode */
|
|
offset_lh = 15; /* flgs,darea,dsubarea,did,sarea,ssub,HIORD */
|
|
break;
|
|
|
|
case Q_AND:
|
|
/* Inefficient because we do our Calvinball dance twice */
|
|
b0 = gen_dnhostop(cstate, addr, Q_SRC);
|
|
b1 = gen_dnhostop(cstate, addr, Q_DST);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case Q_DEFAULT:
|
|
case Q_OR:
|
|
/* Inefficient because we do our Calvinball dance twice */
|
|
b0 = gen_dnhostop(cstate, addr, Q_SRC);
|
|
b1 = gen_dnhostop(cstate, addr, Q_DST);
|
|
gen_or(b0, b1);
|
|
return b1;
|
|
|
|
case Q_ADDR1:
|
|
bpf_error(cstate, "'addr1' and 'address1' are not valid qualifiers for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR2:
|
|
bpf_error(cstate, "'addr2' and 'address2' are not valid qualifiers for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR3:
|
|
bpf_error(cstate, "'addr3' and 'address3' are not valid qualifiers for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR4:
|
|
bpf_error(cstate, "'addr4' and 'address4' are not valid qualifiers for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_RA:
|
|
bpf_error(cstate, "'ra' is not a valid qualifier for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_TA:
|
|
bpf_error(cstate, "'ta' is not a valid qualifier for addresses other than 802.11 MAC addresses");
|
|
/*NOTREACHED*/
|
|
|
|
default:
|
|
abort();
|
|
/*NOTREACHED*/
|
|
}
|
|
b0 = gen_linktype(cstate, ETHERTYPE_DN);
|
|
/* Check for pad = 1, long header case */
|
|
tmp = gen_mcmp(cstate, OR_LINKPL, 2, BPF_H,
|
|
(bpf_int32)ntohs(0x0681), (bpf_int32)ntohs(0x07FF));
|
|
b1 = gen_cmp(cstate, OR_LINKPL, 2 + 1 + offset_lh,
|
|
BPF_H, (bpf_int32)ntohs((u_short)addr));
|
|
gen_and(tmp, b1);
|
|
/* Check for pad = 0, long header case */
|
|
tmp = gen_mcmp(cstate, OR_LINKPL, 2, BPF_B, (bpf_int32)0x06, (bpf_int32)0x7);
|
|
b2 = gen_cmp(cstate, OR_LINKPL, 2 + offset_lh, BPF_H, (bpf_int32)ntohs((u_short)addr));
|
|
gen_and(tmp, b2);
|
|
gen_or(b2, b1);
|
|
/* Check for pad = 1, short header case */
|
|
tmp = gen_mcmp(cstate, OR_LINKPL, 2, BPF_H,
|
|
(bpf_int32)ntohs(0x0281), (bpf_int32)ntohs(0x07FF));
|
|
b2 = gen_cmp(cstate, OR_LINKPL, 2 + 1 + offset_sh, BPF_H, (bpf_int32)ntohs((u_short)addr));
|
|
gen_and(tmp, b2);
|
|
gen_or(b2, b1);
|
|
/* Check for pad = 0, short header case */
|
|
tmp = gen_mcmp(cstate, OR_LINKPL, 2, BPF_B, (bpf_int32)0x02, (bpf_int32)0x7);
|
|
b2 = gen_cmp(cstate, OR_LINKPL, 2 + offset_sh, BPF_H, (bpf_int32)ntohs((u_short)addr));
|
|
gen_and(tmp, b2);
|
|
gen_or(b2, b1);
|
|
|
|
/* Combine with test for cstate->linktype */
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
|
|
/*
|
|
* Generate a check for IPv4 or IPv6 for MPLS-encapsulated packets;
|
|
* test the bottom-of-stack bit, and then check the version number
|
|
* field in the IP header.
|
|
*/
|
|
static struct block *
|
|
gen_mpls_linktype(compiler_state_t *cstate, int proto)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
switch (proto) {
|
|
|
|
case Q_IP:
|
|
/* match the bottom-of-stack bit */
|
|
b0 = gen_mcmp(cstate, OR_LINKPL, (u_int)-2, BPF_B, 0x01, 0x01);
|
|
/* match the IPv4 version number */
|
|
b1 = gen_mcmp(cstate, OR_LINKPL, 0, BPF_B, 0x40, 0xf0);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case Q_IPV6:
|
|
/* match the bottom-of-stack bit */
|
|
b0 = gen_mcmp(cstate, OR_LINKPL, (u_int)-2, BPF_B, 0x01, 0x01);
|
|
/* match the IPv4 version number */
|
|
b1 = gen_mcmp(cstate, OR_LINKPL, 0, BPF_B, 0x60, 0xf0);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
}
|
|
|
|
static struct block *
|
|
gen_host(compiler_state_t *cstate, bpf_u_int32 addr, bpf_u_int32 mask,
|
|
int proto, int dir, int type)
|
|
{
|
|
struct block *b0, *b1;
|
|
const char *typestr;
|
|
|
|
if (type == Q_NET)
|
|
typestr = "net";
|
|
else
|
|
typestr = "host";
|
|
|
|
switch (proto) {
|
|
|
|
case Q_DEFAULT:
|
|
b0 = gen_host(cstate, addr, mask, Q_IP, dir, type);
|
|
/*
|
|
* Only check for non-IPv4 addresses if we're not
|
|
* checking MPLS-encapsulated packets.
|
|
*/
|
|
if (cstate->label_stack_depth == 0) {
|
|
b1 = gen_host(cstate, addr, mask, Q_ARP, dir, type);
|
|
gen_or(b0, b1);
|
|
b0 = gen_host(cstate, addr, mask, Q_RARP, dir, type);
|
|
gen_or(b1, b0);
|
|
}
|
|
return b0;
|
|
|
|
case Q_LINK:
|
|
bpf_error(cstate, "link-layer modifier applied to %s", typestr);
|
|
|
|
case Q_IP:
|
|
return gen_hostop(cstate, addr, mask, dir, ETHERTYPE_IP, 12, 16);
|
|
|
|
case Q_RARP:
|
|
return gen_hostop(cstate, addr, mask, dir, ETHERTYPE_REVARP, 14, 24);
|
|
|
|
case Q_ARP:
|
|
return gen_hostop(cstate, addr, mask, dir, ETHERTYPE_ARP, 14, 24);
|
|
|
|
case Q_SCTP:
|
|
bpf_error(cstate, "'sctp' modifier applied to %s", typestr);
|
|
|
|
case Q_TCP:
|
|
bpf_error(cstate, "'tcp' modifier applied to %s", typestr);
|
|
|
|
case Q_UDP:
|
|
bpf_error(cstate, "'udp' modifier applied to %s", typestr);
|
|
|
|
case Q_ICMP:
|
|
bpf_error(cstate, "'icmp' modifier applied to %s", typestr);
|
|
|
|
case Q_IGMP:
|
|
bpf_error(cstate, "'igmp' modifier applied to %s", typestr);
|
|
|
|
case Q_IGRP:
|
|
bpf_error(cstate, "'igrp' modifier applied to %s", typestr);
|
|
|
|
case Q_ATALK:
|
|
bpf_error(cstate, "AppleTalk host filtering not implemented");
|
|
|
|
case Q_DECNET:
|
|
return gen_dnhostop(cstate, addr, dir);
|
|
|
|
case Q_LAT:
|
|
bpf_error(cstate, "LAT host filtering not implemented");
|
|
|
|
case Q_SCA:
|
|
bpf_error(cstate, "SCA host filtering not implemented");
|
|
|
|
case Q_MOPRC:
|
|
bpf_error(cstate, "MOPRC host filtering not implemented");
|
|
|
|
case Q_MOPDL:
|
|
bpf_error(cstate, "MOPDL host filtering not implemented");
|
|
|
|
case Q_IPV6:
|
|
bpf_error(cstate, "'ip6' modifier applied to ip host");
|
|
|
|
case Q_ICMPV6:
|
|
bpf_error(cstate, "'icmp6' modifier applied to %s", typestr);
|
|
|
|
case Q_AH:
|
|
bpf_error(cstate, "'ah' modifier applied to %s", typestr);
|
|
|
|
case Q_ESP:
|
|
bpf_error(cstate, "'esp' modifier applied to %s", typestr);
|
|
|
|
case Q_PIM:
|
|
bpf_error(cstate, "'pim' modifier applied to %s", typestr);
|
|
|
|
case Q_VRRP:
|
|
bpf_error(cstate, "'vrrp' modifier applied to %s", typestr);
|
|
|
|
case Q_AARP:
|
|
bpf_error(cstate, "AARP host filtering not implemented");
|
|
|
|
case Q_ISO:
|
|
bpf_error(cstate, "ISO host filtering not implemented");
|
|
|
|
case Q_ESIS:
|
|
bpf_error(cstate, "'esis' modifier applied to %s", typestr);
|
|
|
|
case Q_ISIS:
|
|
bpf_error(cstate, "'isis' modifier applied to %s", typestr);
|
|
|
|
case Q_CLNP:
|
|
bpf_error(cstate, "'clnp' modifier applied to %s", typestr);
|
|
|
|
case Q_STP:
|
|
bpf_error(cstate, "'stp' modifier applied to %s", typestr);
|
|
|
|
case Q_IPX:
|
|
bpf_error(cstate, "IPX host filtering not implemented");
|
|
|
|
case Q_NETBEUI:
|
|
bpf_error(cstate, "'netbeui' modifier applied to %s", typestr);
|
|
|
|
case Q_ISIS_L1:
|
|
bpf_error(cstate, "'l1' modifier applied to %s", typestr);
|
|
|
|
case Q_ISIS_L2:
|
|
bpf_error(cstate, "'l2' modifier applied to %s", typestr);
|
|
|
|
case Q_ISIS_IIH:
|
|
bpf_error(cstate, "'iih' modifier applied to %s", typestr);
|
|
|
|
case Q_ISIS_SNP:
|
|
bpf_error(cstate, "'snp' modifier applied to %s", typestr);
|
|
|
|
case Q_ISIS_CSNP:
|
|
bpf_error(cstate, "'csnp' modifier applied to %s", typestr);
|
|
|
|
case Q_ISIS_PSNP:
|
|
bpf_error(cstate, "'psnp' modifier applied to %s", typestr);
|
|
|
|
case Q_ISIS_LSP:
|
|
bpf_error(cstate, "'lsp' modifier applied to %s", typestr);
|
|
|
|
case Q_RADIO:
|
|
bpf_error(cstate, "'radio' modifier applied to %s", typestr);
|
|
|
|
case Q_CARP:
|
|
bpf_error(cstate, "'carp' modifier applied to %s", typestr);
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
#ifdef INET6
|
|
static struct block *
|
|
gen_host6(compiler_state_t *cstate, struct in6_addr *addr,
|
|
struct in6_addr *mask, int proto, int dir, int type)
|
|
{
|
|
const char *typestr;
|
|
|
|
if (type == Q_NET)
|
|
typestr = "net";
|
|
else
|
|
typestr = "host";
|
|
|
|
switch (proto) {
|
|
|
|
case Q_DEFAULT:
|
|
return gen_host6(cstate, addr, mask, Q_IPV6, dir, type);
|
|
|
|
case Q_LINK:
|
|
bpf_error(cstate, "link-layer modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_IP:
|
|
bpf_error(cstate, "'ip' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_RARP:
|
|
bpf_error(cstate, "'rarp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_ARP:
|
|
bpf_error(cstate, "'arp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_SCTP:
|
|
bpf_error(cstate, "'sctp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_TCP:
|
|
bpf_error(cstate, "'tcp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_UDP:
|
|
bpf_error(cstate, "'udp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_ICMP:
|
|
bpf_error(cstate, "'icmp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_IGMP:
|
|
bpf_error(cstate, "'igmp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_IGRP:
|
|
bpf_error(cstate, "'igrp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_ATALK:
|
|
bpf_error(cstate, "AppleTalk modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_DECNET:
|
|
bpf_error(cstate, "'decnet' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_LAT:
|
|
bpf_error(cstate, "'lat' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_SCA:
|
|
bpf_error(cstate, "'sca' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_MOPRC:
|
|
bpf_error(cstate, "'moprc' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_MOPDL:
|
|
bpf_error(cstate, "'mopdl' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_IPV6:
|
|
return gen_hostop6(cstate, addr, mask, dir, ETHERTYPE_IPV6, 8, 24);
|
|
|
|
case Q_ICMPV6:
|
|
bpf_error(cstate, "'icmp6' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_AH:
|
|
bpf_error(cstate, "'ah' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_ESP:
|
|
bpf_error(cstate, "'esp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_PIM:
|
|
bpf_error(cstate, "'pim' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_VRRP:
|
|
bpf_error(cstate, "'vrrp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_AARP:
|
|
bpf_error(cstate, "'aarp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_ISO:
|
|
bpf_error(cstate, "'iso' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_ESIS:
|
|
bpf_error(cstate, "'esis' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_ISIS:
|
|
bpf_error(cstate, "'isis' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_CLNP:
|
|
bpf_error(cstate, "'clnp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_STP:
|
|
bpf_error(cstate, "'stp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_IPX:
|
|
bpf_error(cstate, "'ipx' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_NETBEUI:
|
|
bpf_error(cstate, "'netbeui' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_ISIS_L1:
|
|
bpf_error(cstate, "'l1' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_ISIS_L2:
|
|
bpf_error(cstate, "'l2' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_ISIS_IIH:
|
|
bpf_error(cstate, "'iih' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_ISIS_SNP:
|
|
bpf_error(cstate, "'snp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_ISIS_CSNP:
|
|
bpf_error(cstate, "'csnp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_ISIS_PSNP:
|
|
bpf_error(cstate, "'psnp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_ISIS_LSP:
|
|
bpf_error(cstate, "'lsp' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_RADIO:
|
|
bpf_error(cstate, "'radio' modifier applied to ip6 %s", typestr);
|
|
|
|
case Q_CARP:
|
|
bpf_error(cstate, "'carp' modifier applied to ip6 %s", typestr);
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
/*NOTREACHED*/
|
|
}
|
|
#endif
|
|
|
|
#ifndef INET6
|
|
static struct block *
|
|
gen_gateway(compiler_state_t *cstate, const u_char *eaddr,
|
|
struct addrinfo *alist, int proto, int dir)
|
|
{
|
|
struct block *b0, *b1, *tmp;
|
|
struct addrinfo *ai;
|
|
struct sockaddr_in *sin;
|
|
|
|
if (dir != 0)
|
|
bpf_error(cstate, "direction applied to 'gateway'");
|
|
|
|
switch (proto) {
|
|
case Q_DEFAULT:
|
|
case Q_IP:
|
|
case Q_ARP:
|
|
case Q_RARP:
|
|
switch (cstate->linktype) {
|
|
case DLT_EN10MB:
|
|
case DLT_NETANALYZER:
|
|
case DLT_NETANALYZER_TRANSPARENT:
|
|
b1 = gen_prevlinkhdr_check(cstate);
|
|
b0 = gen_ehostop(cstate, eaddr, Q_OR);
|
|
if (b1 != NULL)
|
|
gen_and(b1, b0);
|
|
break;
|
|
case DLT_FDDI:
|
|
b0 = gen_fhostop(cstate, eaddr, Q_OR);
|
|
break;
|
|
case DLT_IEEE802:
|
|
b0 = gen_thostop(cstate, eaddr, Q_OR);
|
|
break;
|
|
case DLT_IEEE802_11:
|
|
case DLT_PRISM_HEADER:
|
|
case DLT_IEEE802_11_RADIO_AVS:
|
|
case DLT_IEEE802_11_RADIO:
|
|
case DLT_PPI:
|
|
b0 = gen_wlanhostop(cstate, eaddr, Q_OR);
|
|
break;
|
|
case DLT_SUNATM:
|
|
/*
|
|
* This is LLC-multiplexed traffic; if it were
|
|
* LANE, cstate->linktype would have been set to
|
|
* DLT_EN10MB.
|
|
*/
|
|
bpf_error(cstate,
|
|
"'gateway' supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
|
|
break;
|
|
case DLT_IP_OVER_FC:
|
|
b0 = gen_ipfchostop(cstate, eaddr, Q_OR);
|
|
break;
|
|
default:
|
|
bpf_error(cstate,
|
|
"'gateway' supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
|
|
}
|
|
b1 = NULL;
|
|
for (ai = alist; ai != NULL; ai = ai->ai_next) {
|
|
/*
|
|
* Does it have an address?
|
|
*/
|
|
if (ai->ai_addr != NULL) {
|
|
/*
|
|
* Yes. Is it an IPv4 address?
|
|
*/
|
|
if (ai->ai_addr->sa_family == AF_INET) {
|
|
/*
|
|
* Generate an entry for it.
|
|
*/
|
|
sin = (struct sockaddr_in *)ai->ai_addr;
|
|
tmp = gen_host(cstate,
|
|
ntohl(sin->sin_addr.s_addr),
|
|
0xffffffff, proto, Q_OR, Q_HOST);
|
|
/*
|
|
* Is it the *first* IPv4 address?
|
|
*/
|
|
if (b1 == NULL) {
|
|
/*
|
|
* Yes, so start with it.
|
|
*/
|
|
b1 = tmp;
|
|
} else {
|
|
/*
|
|
* No, so OR it into the
|
|
* existing set of
|
|
* addresses.
|
|
*/
|
|
gen_or(b1, tmp);
|
|
b1 = tmp;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (b1 == NULL) {
|
|
/*
|
|
* No IPv4 addresses found.
|
|
*/
|
|
return (NULL);
|
|
}
|
|
gen_not(b1);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
bpf_error(cstate, "illegal modifier of 'gateway'");
|
|
/*NOTREACHED*/
|
|
}
|
|
#endif
|
|
|
|
static struct block *
|
|
gen_proto_abbrev_internal(compiler_state_t *cstate, int proto)
|
|
{
|
|
struct block *b0;
|
|
struct block *b1;
|
|
|
|
switch (proto) {
|
|
|
|
case Q_SCTP:
|
|
b1 = gen_proto(cstate, IPPROTO_SCTP, Q_IP, Q_DEFAULT);
|
|
b0 = gen_proto(cstate, IPPROTO_SCTP, Q_IPV6, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
break;
|
|
|
|
case Q_TCP:
|
|
b1 = gen_proto(cstate, IPPROTO_TCP, Q_IP, Q_DEFAULT);
|
|
b0 = gen_proto(cstate, IPPROTO_TCP, Q_IPV6, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
break;
|
|
|
|
case Q_UDP:
|
|
b1 = gen_proto(cstate, IPPROTO_UDP, Q_IP, Q_DEFAULT);
|
|
b0 = gen_proto(cstate, IPPROTO_UDP, Q_IPV6, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
break;
|
|
|
|
case Q_ICMP:
|
|
b1 = gen_proto(cstate, IPPROTO_ICMP, Q_IP, Q_DEFAULT);
|
|
break;
|
|
|
|
#ifndef IPPROTO_IGMP
|
|
#define IPPROTO_IGMP 2
|
|
#endif
|
|
|
|
case Q_IGMP:
|
|
b1 = gen_proto(cstate, IPPROTO_IGMP, Q_IP, Q_DEFAULT);
|
|
break;
|
|
|
|
#ifndef IPPROTO_IGRP
|
|
#define IPPROTO_IGRP 9
|
|
#endif
|
|
case Q_IGRP:
|
|
b1 = gen_proto(cstate, IPPROTO_IGRP, Q_IP, Q_DEFAULT);
|
|
break;
|
|
|
|
#ifndef IPPROTO_PIM
|
|
#define IPPROTO_PIM 103
|
|
#endif
|
|
|
|
case Q_PIM:
|
|
b1 = gen_proto(cstate, IPPROTO_PIM, Q_IP, Q_DEFAULT);
|
|
b0 = gen_proto(cstate, IPPROTO_PIM, Q_IPV6, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
break;
|
|
|
|
#ifndef IPPROTO_VRRP
|
|
#define IPPROTO_VRRP 112
|
|
#endif
|
|
|
|
case Q_VRRP:
|
|
b1 = gen_proto(cstate, IPPROTO_VRRP, Q_IP, Q_DEFAULT);
|
|
break;
|
|
|
|
#ifndef IPPROTO_CARP
|
|
#define IPPROTO_CARP 112
|
|
#endif
|
|
|
|
case Q_CARP:
|
|
b1 = gen_proto(cstate, IPPROTO_CARP, Q_IP, Q_DEFAULT);
|
|
break;
|
|
|
|
case Q_IP:
|
|
b1 = gen_linktype(cstate, ETHERTYPE_IP);
|
|
break;
|
|
|
|
case Q_ARP:
|
|
b1 = gen_linktype(cstate, ETHERTYPE_ARP);
|
|
break;
|
|
|
|
case Q_RARP:
|
|
b1 = gen_linktype(cstate, ETHERTYPE_REVARP);
|
|
break;
|
|
|
|
case Q_LINK:
|
|
bpf_error(cstate, "link layer applied in wrong context");
|
|
|
|
case Q_ATALK:
|
|
b1 = gen_linktype(cstate, ETHERTYPE_ATALK);
|
|
break;
|
|
|
|
case Q_AARP:
|
|
b1 = gen_linktype(cstate, ETHERTYPE_AARP);
|
|
break;
|
|
|
|
case Q_DECNET:
|
|
b1 = gen_linktype(cstate, ETHERTYPE_DN);
|
|
break;
|
|
|
|
case Q_SCA:
|
|
b1 = gen_linktype(cstate, ETHERTYPE_SCA);
|
|
break;
|
|
|
|
case Q_LAT:
|
|
b1 = gen_linktype(cstate, ETHERTYPE_LAT);
|
|
break;
|
|
|
|
case Q_MOPDL:
|
|
b1 = gen_linktype(cstate, ETHERTYPE_MOPDL);
|
|
break;
|
|
|
|
case Q_MOPRC:
|
|
b1 = gen_linktype(cstate, ETHERTYPE_MOPRC);
|
|
break;
|
|
|
|
case Q_IPV6:
|
|
b1 = gen_linktype(cstate, ETHERTYPE_IPV6);
|
|
break;
|
|
|
|
#ifndef IPPROTO_ICMPV6
|
|
#define IPPROTO_ICMPV6 58
|
|
#endif
|
|
case Q_ICMPV6:
|
|
b1 = gen_proto(cstate, IPPROTO_ICMPV6, Q_IPV6, Q_DEFAULT);
|
|
break;
|
|
|
|
#ifndef IPPROTO_AH
|
|
#define IPPROTO_AH 51
|
|
#endif
|
|
case Q_AH:
|
|
b1 = gen_proto(cstate, IPPROTO_AH, Q_IP, Q_DEFAULT);
|
|
b0 = gen_proto(cstate, IPPROTO_AH, Q_IPV6, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
break;
|
|
|
|
#ifndef IPPROTO_ESP
|
|
#define IPPROTO_ESP 50
|
|
#endif
|
|
case Q_ESP:
|
|
b1 = gen_proto(cstate, IPPROTO_ESP, Q_IP, Q_DEFAULT);
|
|
b0 = gen_proto(cstate, IPPROTO_ESP, Q_IPV6, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
break;
|
|
|
|
case Q_ISO:
|
|
b1 = gen_linktype(cstate, LLCSAP_ISONS);
|
|
break;
|
|
|
|
case Q_ESIS:
|
|
b1 = gen_proto(cstate, ISO9542_ESIS, Q_ISO, Q_DEFAULT);
|
|
break;
|
|
|
|
case Q_ISIS:
|
|
b1 = gen_proto(cstate, ISO10589_ISIS, Q_ISO, Q_DEFAULT);
|
|
break;
|
|
|
|
case Q_ISIS_L1: /* all IS-IS Level1 PDU-Types */
|
|
b0 = gen_proto(cstate, ISIS_L1_LAN_IIH, Q_ISIS, Q_DEFAULT);
|
|
b1 = gen_proto(cstate, ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT); /* FIXME extract the circuit-type bits */
|
|
gen_or(b0, b1);
|
|
b0 = gen_proto(cstate, ISIS_L1_LSP, Q_ISIS, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
b0 = gen_proto(cstate, ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
b0 = gen_proto(cstate, ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
break;
|
|
|
|
case Q_ISIS_L2: /* all IS-IS Level2 PDU-Types */
|
|
b0 = gen_proto(cstate, ISIS_L2_LAN_IIH, Q_ISIS, Q_DEFAULT);
|
|
b1 = gen_proto(cstate, ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT); /* FIXME extract the circuit-type bits */
|
|
gen_or(b0, b1);
|
|
b0 = gen_proto(cstate, ISIS_L2_LSP, Q_ISIS, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
b0 = gen_proto(cstate, ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
b0 = gen_proto(cstate, ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
break;
|
|
|
|
case Q_ISIS_IIH: /* all IS-IS Hello PDU-Types */
|
|
b0 = gen_proto(cstate, ISIS_L1_LAN_IIH, Q_ISIS, Q_DEFAULT);
|
|
b1 = gen_proto(cstate, ISIS_L2_LAN_IIH, Q_ISIS, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
b0 = gen_proto(cstate, ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
break;
|
|
|
|
case Q_ISIS_LSP:
|
|
b0 = gen_proto(cstate, ISIS_L1_LSP, Q_ISIS, Q_DEFAULT);
|
|
b1 = gen_proto(cstate, ISIS_L2_LSP, Q_ISIS, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
break;
|
|
|
|
case Q_ISIS_SNP:
|
|
b0 = gen_proto(cstate, ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT);
|
|
b1 = gen_proto(cstate, ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
b0 = gen_proto(cstate, ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
b0 = gen_proto(cstate, ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
break;
|
|
|
|
case Q_ISIS_CSNP:
|
|
b0 = gen_proto(cstate, ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT);
|
|
b1 = gen_proto(cstate, ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
break;
|
|
|
|
case Q_ISIS_PSNP:
|
|
b0 = gen_proto(cstate, ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT);
|
|
b1 = gen_proto(cstate, ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT);
|
|
gen_or(b0, b1);
|
|
break;
|
|
|
|
case Q_CLNP:
|
|
b1 = gen_proto(cstate, ISO8473_CLNP, Q_ISO, Q_DEFAULT);
|
|
break;
|
|
|
|
case Q_STP:
|
|
b1 = gen_linktype(cstate, LLCSAP_8021D);
|
|
break;
|
|
|
|
case Q_IPX:
|
|
b1 = gen_linktype(cstate, LLCSAP_IPX);
|
|
break;
|
|
|
|
case Q_NETBEUI:
|
|
b1 = gen_linktype(cstate, LLCSAP_NETBEUI);
|
|
break;
|
|
|
|
case Q_RADIO:
|
|
bpf_error(cstate, "'radio' is not a valid protocol type");
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
return b1;
|
|
}
|
|
|
|
struct block *
|
|
gen_proto_abbrev(compiler_state_t *cstate, int proto)
|
|
{
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
return gen_proto_abbrev_internal(cstate, proto);
|
|
}
|
|
|
|
static struct block *
|
|
gen_ipfrag(compiler_state_t *cstate)
|
|
{
|
|
struct slist *s;
|
|
struct block *b;
|
|
|
|
/* not IPv4 frag other than the first frag */
|
|
s = gen_load_a(cstate, OR_LINKPL, 6, BPF_H);
|
|
b = new_block(cstate, JMP(BPF_JSET));
|
|
b->s.k = 0x1fff;
|
|
b->stmts = s;
|
|
gen_not(b);
|
|
|
|
return b;
|
|
}
|
|
|
|
/*
|
|
* Generate a comparison to a port value in the transport-layer header
|
|
* at the specified offset from the beginning of that header.
|
|
*
|
|
* XXX - this handles a variable-length prefix preceding the link-layer
|
|
* header, such as the radiotap or AVS radio prefix, but doesn't handle
|
|
* variable-length link-layer headers (such as Token Ring or 802.11
|
|
* headers).
|
|
*/
|
|
static struct block *
|
|
gen_portatom(compiler_state_t *cstate, int off, bpf_int32 v)
|
|
{
|
|
return gen_cmp(cstate, OR_TRAN_IPV4, off, BPF_H, v);
|
|
}
|
|
|
|
static struct block *
|
|
gen_portatom6(compiler_state_t *cstate, int off, bpf_int32 v)
|
|
{
|
|
return gen_cmp(cstate, OR_TRAN_IPV6, off, BPF_H, v);
|
|
}
|
|
|
|
struct block *
|
|
gen_portop(compiler_state_t *cstate, int port, int proto, int dir)
|
|
{
|
|
struct block *b0, *b1, *tmp;
|
|
|
|
/* ip proto 'proto' and not a fragment other than the first fragment */
|
|
tmp = gen_cmp(cstate, OR_LINKPL, 9, BPF_B, (bpf_int32)proto);
|
|
b0 = gen_ipfrag(cstate);
|
|
gen_and(tmp, b0);
|
|
|
|
switch (dir) {
|
|
case Q_SRC:
|
|
b1 = gen_portatom(cstate, 0, (bpf_int32)port);
|
|
break;
|
|
|
|
case Q_DST:
|
|
b1 = gen_portatom(cstate, 2, (bpf_int32)port);
|
|
break;
|
|
|
|
case Q_AND:
|
|
tmp = gen_portatom(cstate, 0, (bpf_int32)port);
|
|
b1 = gen_portatom(cstate, 2, (bpf_int32)port);
|
|
gen_and(tmp, b1);
|
|
break;
|
|
|
|
case Q_DEFAULT:
|
|
case Q_OR:
|
|
tmp = gen_portatom(cstate, 0, (bpf_int32)port);
|
|
b1 = gen_portatom(cstate, 2, (bpf_int32)port);
|
|
gen_or(tmp, b1);
|
|
break;
|
|
|
|
case Q_ADDR1:
|
|
bpf_error(cstate, "'addr1' and 'address1' are not valid qualifiers for ports");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR2:
|
|
bpf_error(cstate, "'addr2' and 'address2' are not valid qualifiers for ports");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR3:
|
|
bpf_error(cstate, "'addr3' and 'address3' are not valid qualifiers for ports");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR4:
|
|
bpf_error(cstate, "'addr4' and 'address4' are not valid qualifiers for ports");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_RA:
|
|
bpf_error(cstate, "'ra' is not a valid qualifier for ports");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_TA:
|
|
bpf_error(cstate, "'ta' is not a valid qualifier for ports");
|
|
/*NOTREACHED*/
|
|
|
|
default:
|
|
abort();
|
|
/*NOTREACHED*/
|
|
}
|
|
gen_and(b0, b1);
|
|
|
|
return b1;
|
|
}
|
|
|
|
static struct block *
|
|
gen_port(compiler_state_t *cstate, int port, int ip_proto, int dir)
|
|
{
|
|
struct block *b0, *b1, *tmp;
|
|
|
|
/*
|
|
* ether proto ip
|
|
*
|
|
* For FDDI, RFC 1188 says that SNAP encapsulation is used,
|
|
* not LLC encapsulation with LLCSAP_IP.
|
|
*
|
|
* For IEEE 802 networks - which includes 802.5 token ring
|
|
* (which is what DLT_IEEE802 means) and 802.11 - RFC 1042
|
|
* says that SNAP encapsulation is used, not LLC encapsulation
|
|
* with LLCSAP_IP.
|
|
*
|
|
* For LLC-encapsulated ATM/"Classical IP", RFC 1483 and
|
|
* RFC 2225 say that SNAP encapsulation is used, not LLC
|
|
* encapsulation with LLCSAP_IP.
|
|
*
|
|
* So we always check for ETHERTYPE_IP.
|
|
*/
|
|
b0 = gen_linktype(cstate, ETHERTYPE_IP);
|
|
|
|
switch (ip_proto) {
|
|
case IPPROTO_UDP:
|
|
case IPPROTO_TCP:
|
|
case IPPROTO_SCTP:
|
|
b1 = gen_portop(cstate, port, ip_proto, dir);
|
|
break;
|
|
|
|
case PROTO_UNDEF:
|
|
tmp = gen_portop(cstate, port, IPPROTO_TCP, dir);
|
|
b1 = gen_portop(cstate, port, IPPROTO_UDP, dir);
|
|
gen_or(tmp, b1);
|
|
tmp = gen_portop(cstate, port, IPPROTO_SCTP, dir);
|
|
gen_or(tmp, b1);
|
|
break;
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
|
|
struct block *
|
|
gen_portop6(compiler_state_t *cstate, int port, int proto, int dir)
|
|
{
|
|
struct block *b0, *b1, *tmp;
|
|
|
|
/* ip6 proto 'proto' */
|
|
/* XXX - catch the first fragment of a fragmented packet? */
|
|
b0 = gen_cmp(cstate, OR_LINKPL, 6, BPF_B, (bpf_int32)proto);
|
|
|
|
switch (dir) {
|
|
case Q_SRC:
|
|
b1 = gen_portatom6(cstate, 0, (bpf_int32)port);
|
|
break;
|
|
|
|
case Q_DST:
|
|
b1 = gen_portatom6(cstate, 2, (bpf_int32)port);
|
|
break;
|
|
|
|
case Q_AND:
|
|
tmp = gen_portatom6(cstate, 0, (bpf_int32)port);
|
|
b1 = gen_portatom6(cstate, 2, (bpf_int32)port);
|
|
gen_and(tmp, b1);
|
|
break;
|
|
|
|
case Q_DEFAULT:
|
|
case Q_OR:
|
|
tmp = gen_portatom6(cstate, 0, (bpf_int32)port);
|
|
b1 = gen_portatom6(cstate, 2, (bpf_int32)port);
|
|
gen_or(tmp, b1);
|
|
break;
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
gen_and(b0, b1);
|
|
|
|
return b1;
|
|
}
|
|
|
|
static struct block *
|
|
gen_port6(compiler_state_t *cstate, int port, int ip_proto, int dir)
|
|
{
|
|
struct block *b0, *b1, *tmp;
|
|
|
|
/* link proto ip6 */
|
|
b0 = gen_linktype(cstate, ETHERTYPE_IPV6);
|
|
|
|
switch (ip_proto) {
|
|
case IPPROTO_UDP:
|
|
case IPPROTO_TCP:
|
|
case IPPROTO_SCTP:
|
|
b1 = gen_portop6(cstate, port, ip_proto, dir);
|
|
break;
|
|
|
|
case PROTO_UNDEF:
|
|
tmp = gen_portop6(cstate, port, IPPROTO_TCP, dir);
|
|
b1 = gen_portop6(cstate, port, IPPROTO_UDP, dir);
|
|
gen_or(tmp, b1);
|
|
tmp = gen_portop6(cstate, port, IPPROTO_SCTP, dir);
|
|
gen_or(tmp, b1);
|
|
break;
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
|
|
/* gen_portrange code */
|
|
static struct block *
|
|
gen_portrangeatom(compiler_state_t *cstate, int off, bpf_int32 v1,
|
|
bpf_int32 v2)
|
|
{
|
|
struct block *b1, *b2;
|
|
|
|
if (v1 > v2) {
|
|
/*
|
|
* Reverse the order of the ports, so v1 is the lower one.
|
|
*/
|
|
bpf_int32 vtemp;
|
|
|
|
vtemp = v1;
|
|
v1 = v2;
|
|
v2 = vtemp;
|
|
}
|
|
|
|
b1 = gen_cmp_ge(cstate, OR_TRAN_IPV4, off, BPF_H, v1);
|
|
b2 = gen_cmp_le(cstate, OR_TRAN_IPV4, off, BPF_H, v2);
|
|
|
|
gen_and(b1, b2);
|
|
|
|
return b2;
|
|
}
|
|
|
|
struct block *
|
|
gen_portrangeop(compiler_state_t *cstate, int port1, int port2, int proto,
|
|
int dir)
|
|
{
|
|
struct block *b0, *b1, *tmp;
|
|
|
|
/* ip proto 'proto' and not a fragment other than the first fragment */
|
|
tmp = gen_cmp(cstate, OR_LINKPL, 9, BPF_B, (bpf_int32)proto);
|
|
b0 = gen_ipfrag(cstate);
|
|
gen_and(tmp, b0);
|
|
|
|
switch (dir) {
|
|
case Q_SRC:
|
|
b1 = gen_portrangeatom(cstate, 0, (bpf_int32)port1, (bpf_int32)port2);
|
|
break;
|
|
|
|
case Q_DST:
|
|
b1 = gen_portrangeatom(cstate, 2, (bpf_int32)port1, (bpf_int32)port2);
|
|
break;
|
|
|
|
case Q_AND:
|
|
tmp = gen_portrangeatom(cstate, 0, (bpf_int32)port1, (bpf_int32)port2);
|
|
b1 = gen_portrangeatom(cstate, 2, (bpf_int32)port1, (bpf_int32)port2);
|
|
gen_and(tmp, b1);
|
|
break;
|
|
|
|
case Q_DEFAULT:
|
|
case Q_OR:
|
|
tmp = gen_portrangeatom(cstate, 0, (bpf_int32)port1, (bpf_int32)port2);
|
|
b1 = gen_portrangeatom(cstate, 2, (bpf_int32)port1, (bpf_int32)port2);
|
|
gen_or(tmp, b1);
|
|
break;
|
|
|
|
case Q_ADDR1:
|
|
bpf_error(cstate, "'addr1' and 'address1' are not valid qualifiers for port ranges");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR2:
|
|
bpf_error(cstate, "'addr2' and 'address2' are not valid qualifiers for port ranges");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR3:
|
|
bpf_error(cstate, "'addr3' and 'address3' are not valid qualifiers for port ranges");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR4:
|
|
bpf_error(cstate, "'addr4' and 'address4' are not valid qualifiers for port ranges");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_RA:
|
|
bpf_error(cstate, "'ra' is not a valid qualifier for port ranges");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_TA:
|
|
bpf_error(cstate, "'ta' is not a valid qualifier for port ranges");
|
|
/*NOTREACHED*/
|
|
|
|
default:
|
|
abort();
|
|
/*NOTREACHED*/
|
|
}
|
|
gen_and(b0, b1);
|
|
|
|
return b1;
|
|
}
|
|
|
|
static struct block *
|
|
gen_portrange(compiler_state_t *cstate, int port1, int port2, int ip_proto,
|
|
int dir)
|
|
{
|
|
struct block *b0, *b1, *tmp;
|
|
|
|
/* link proto ip */
|
|
b0 = gen_linktype(cstate, ETHERTYPE_IP);
|
|
|
|
switch (ip_proto) {
|
|
case IPPROTO_UDP:
|
|
case IPPROTO_TCP:
|
|
case IPPROTO_SCTP:
|
|
b1 = gen_portrangeop(cstate, port1, port2, ip_proto, dir);
|
|
break;
|
|
|
|
case PROTO_UNDEF:
|
|
tmp = gen_portrangeop(cstate, port1, port2, IPPROTO_TCP, dir);
|
|
b1 = gen_portrangeop(cstate, port1, port2, IPPROTO_UDP, dir);
|
|
gen_or(tmp, b1);
|
|
tmp = gen_portrangeop(cstate, port1, port2, IPPROTO_SCTP, dir);
|
|
gen_or(tmp, b1);
|
|
break;
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
|
|
static struct block *
|
|
gen_portrangeatom6(compiler_state_t *cstate, int off, bpf_int32 v1,
|
|
bpf_int32 v2)
|
|
{
|
|
struct block *b1, *b2;
|
|
|
|
if (v1 > v2) {
|
|
/*
|
|
* Reverse the order of the ports, so v1 is the lower one.
|
|
*/
|
|
bpf_int32 vtemp;
|
|
|
|
vtemp = v1;
|
|
v1 = v2;
|
|
v2 = vtemp;
|
|
}
|
|
|
|
b1 = gen_cmp_ge(cstate, OR_TRAN_IPV6, off, BPF_H, v1);
|
|
b2 = gen_cmp_le(cstate, OR_TRAN_IPV6, off, BPF_H, v2);
|
|
|
|
gen_and(b1, b2);
|
|
|
|
return b2;
|
|
}
|
|
|
|
struct block *
|
|
gen_portrangeop6(compiler_state_t *cstate, int port1, int port2, int proto,
|
|
int dir)
|
|
{
|
|
struct block *b0, *b1, *tmp;
|
|
|
|
/* ip6 proto 'proto' */
|
|
/* XXX - catch the first fragment of a fragmented packet? */
|
|
b0 = gen_cmp(cstate, OR_LINKPL, 6, BPF_B, (bpf_int32)proto);
|
|
|
|
switch (dir) {
|
|
case Q_SRC:
|
|
b1 = gen_portrangeatom6(cstate, 0, (bpf_int32)port1, (bpf_int32)port2);
|
|
break;
|
|
|
|
case Q_DST:
|
|
b1 = gen_portrangeatom6(cstate, 2, (bpf_int32)port1, (bpf_int32)port2);
|
|
break;
|
|
|
|
case Q_AND:
|
|
tmp = gen_portrangeatom6(cstate, 0, (bpf_int32)port1, (bpf_int32)port2);
|
|
b1 = gen_portrangeatom6(cstate, 2, (bpf_int32)port1, (bpf_int32)port2);
|
|
gen_and(tmp, b1);
|
|
break;
|
|
|
|
case Q_DEFAULT:
|
|
case Q_OR:
|
|
tmp = gen_portrangeatom6(cstate, 0, (bpf_int32)port1, (bpf_int32)port2);
|
|
b1 = gen_portrangeatom6(cstate, 2, (bpf_int32)port1, (bpf_int32)port2);
|
|
gen_or(tmp, b1);
|
|
break;
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
gen_and(b0, b1);
|
|
|
|
return b1;
|
|
}
|
|
|
|
static struct block *
|
|
gen_portrange6(compiler_state_t *cstate, int port1, int port2, int ip_proto,
|
|
int dir)
|
|
{
|
|
struct block *b0, *b1, *tmp;
|
|
|
|
/* link proto ip6 */
|
|
b0 = gen_linktype(cstate, ETHERTYPE_IPV6);
|
|
|
|
switch (ip_proto) {
|
|
case IPPROTO_UDP:
|
|
case IPPROTO_TCP:
|
|
case IPPROTO_SCTP:
|
|
b1 = gen_portrangeop6(cstate, port1, port2, ip_proto, dir);
|
|
break;
|
|
|
|
case PROTO_UNDEF:
|
|
tmp = gen_portrangeop6(cstate, port1, port2, IPPROTO_TCP, dir);
|
|
b1 = gen_portrangeop6(cstate, port1, port2, IPPROTO_UDP, dir);
|
|
gen_or(tmp, b1);
|
|
tmp = gen_portrangeop6(cstate, port1, port2, IPPROTO_SCTP, dir);
|
|
gen_or(tmp, b1);
|
|
break;
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
|
|
static int
|
|
lookup_proto(compiler_state_t *cstate, const char *name, int proto)
|
|
{
|
|
register int v;
|
|
|
|
switch (proto) {
|
|
|
|
case Q_DEFAULT:
|
|
case Q_IP:
|
|
case Q_IPV6:
|
|
v = pcap_nametoproto(name);
|
|
if (v == PROTO_UNDEF)
|
|
bpf_error(cstate, "unknown ip proto '%s'", name);
|
|
break;
|
|
|
|
case Q_LINK:
|
|
/* XXX should look up h/w protocol type based on cstate->linktype */
|
|
v = pcap_nametoeproto(name);
|
|
if (v == PROTO_UNDEF) {
|
|
v = pcap_nametollc(name);
|
|
if (v == PROTO_UNDEF)
|
|
bpf_error(cstate, "unknown ether proto '%s'", name);
|
|
}
|
|
break;
|
|
|
|
case Q_ISO:
|
|
if (strcmp(name, "esis") == 0)
|
|
v = ISO9542_ESIS;
|
|
else if (strcmp(name, "isis") == 0)
|
|
v = ISO10589_ISIS;
|
|
else if (strcmp(name, "clnp") == 0)
|
|
v = ISO8473_CLNP;
|
|
else
|
|
bpf_error(cstate, "unknown osi proto '%s'", name);
|
|
break;
|
|
|
|
default:
|
|
v = PROTO_UNDEF;
|
|
break;
|
|
}
|
|
return v;
|
|
}
|
|
|
|
#if 0
|
|
struct stmt *
|
|
gen_joinsp(struct stmt **s, int n)
|
|
{
|
|
return NULL;
|
|
}
|
|
#endif
|
|
|
|
static struct block *
|
|
gen_protochain(compiler_state_t *cstate, int v, int proto, int dir)
|
|
{
|
|
#ifdef NO_PROTOCHAIN
|
|
return gen_proto(cstate, v, proto, dir);
|
|
#else
|
|
struct block *b0, *b;
|
|
struct slist *s[100];
|
|
int fix2, fix3, fix4, fix5;
|
|
int ahcheck, again, end;
|
|
int i, max;
|
|
int reg2 = alloc_reg(cstate);
|
|
|
|
memset(s, 0, sizeof(s));
|
|
fix3 = fix4 = fix5 = 0;
|
|
|
|
switch (proto) {
|
|
case Q_IP:
|
|
case Q_IPV6:
|
|
break;
|
|
case Q_DEFAULT:
|
|
b0 = gen_protochain(cstate, v, Q_IP, dir);
|
|
b = gen_protochain(cstate, v, Q_IPV6, dir);
|
|
gen_or(b0, b);
|
|
return b;
|
|
default:
|
|
bpf_error(cstate, "bad protocol applied for 'protochain'");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
/*
|
|
* We don't handle variable-length prefixes before the link-layer
|
|
* header, or variable-length link-layer headers, here yet.
|
|
* We might want to add BPF instructions to do the protochain
|
|
* work, to simplify that and, on platforms that have a BPF
|
|
* interpreter with the new instructions, let the filtering
|
|
* be done in the kernel. (We already require a modified BPF
|
|
* engine to do the protochain stuff, to support backward
|
|
* branches, and backward branch support is unlikely to appear
|
|
* in kernel BPF engines.)
|
|
*/
|
|
if (cstate->off_linkpl.is_variable)
|
|
bpf_error(cstate, "'protochain' not supported with variable length headers");
|
|
|
|
cstate->no_optimize = 1; /* this code is not compatible with optimizer yet */
|
|
|
|
/*
|
|
* s[0] is a dummy entry to protect other BPF insn from damage
|
|
* by s[fix] = foo with uninitialized variable "fix". It is somewhat
|
|
* hard to find interdependency made by jump table fixup.
|
|
*/
|
|
i = 0;
|
|
s[i] = new_stmt(cstate, 0); /*dummy*/
|
|
i++;
|
|
|
|
switch (proto) {
|
|
case Q_IP:
|
|
b0 = gen_linktype(cstate, ETHERTYPE_IP);
|
|
|
|
/* A = ip->ip_p */
|
|
s[i] = new_stmt(cstate, BPF_LD|BPF_ABS|BPF_B);
|
|
s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + 9;
|
|
i++;
|
|
/* X = ip->ip_hl << 2 */
|
|
s[i] = new_stmt(cstate, BPF_LDX|BPF_MSH|BPF_B);
|
|
s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
|
|
i++;
|
|
break;
|
|
|
|
case Q_IPV6:
|
|
b0 = gen_linktype(cstate, ETHERTYPE_IPV6);
|
|
|
|
/* A = ip6->ip_nxt */
|
|
s[i] = new_stmt(cstate, BPF_LD|BPF_ABS|BPF_B);
|
|
s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + 6;
|
|
i++;
|
|
/* X = sizeof(struct ip6_hdr) */
|
|
s[i] = new_stmt(cstate, BPF_LDX|BPF_IMM);
|
|
s[i]->s.k = 40;
|
|
i++;
|
|
break;
|
|
|
|
default:
|
|
bpf_error(cstate, "unsupported proto to gen_protochain");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
/* again: if (A == v) goto end; else fall through; */
|
|
again = i;
|
|
s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K);
|
|
s[i]->s.k = v;
|
|
s[i]->s.jt = NULL; /*later*/
|
|
s[i]->s.jf = NULL; /*update in next stmt*/
|
|
fix5 = i;
|
|
i++;
|
|
|
|
#ifndef IPPROTO_NONE
|
|
#define IPPROTO_NONE 59
|
|
#endif
|
|
/* if (A == IPPROTO_NONE) goto end */
|
|
s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K);
|
|
s[i]->s.jt = NULL; /*later*/
|
|
s[i]->s.jf = NULL; /*update in next stmt*/
|
|
s[i]->s.k = IPPROTO_NONE;
|
|
s[fix5]->s.jf = s[i];
|
|
fix2 = i;
|
|
i++;
|
|
|
|
if (proto == Q_IPV6) {
|
|
int v6start, v6end, v6advance, j;
|
|
|
|
v6start = i;
|
|
/* if (A == IPPROTO_HOPOPTS) goto v6advance */
|
|
s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K);
|
|
s[i]->s.jt = NULL; /*later*/
|
|
s[i]->s.jf = NULL; /*update in next stmt*/
|
|
s[i]->s.k = IPPROTO_HOPOPTS;
|
|
s[fix2]->s.jf = s[i];
|
|
i++;
|
|
/* if (A == IPPROTO_DSTOPTS) goto v6advance */
|
|
s[i - 1]->s.jf = s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K);
|
|
s[i]->s.jt = NULL; /*later*/
|
|
s[i]->s.jf = NULL; /*update in next stmt*/
|
|
s[i]->s.k = IPPROTO_DSTOPTS;
|
|
i++;
|
|
/* if (A == IPPROTO_ROUTING) goto v6advance */
|
|
s[i - 1]->s.jf = s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K);
|
|
s[i]->s.jt = NULL; /*later*/
|
|
s[i]->s.jf = NULL; /*update in next stmt*/
|
|
s[i]->s.k = IPPROTO_ROUTING;
|
|
i++;
|
|
/* if (A == IPPROTO_FRAGMENT) goto v6advance; else goto ahcheck; */
|
|
s[i - 1]->s.jf = s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K);
|
|
s[i]->s.jt = NULL; /*later*/
|
|
s[i]->s.jf = NULL; /*later*/
|
|
s[i]->s.k = IPPROTO_FRAGMENT;
|
|
fix3 = i;
|
|
v6end = i;
|
|
i++;
|
|
|
|
/* v6advance: */
|
|
v6advance = i;
|
|
|
|
/*
|
|
* in short,
|
|
* A = P[X + packet head];
|
|
* X = X + (P[X + packet head + 1] + 1) * 8;
|
|
*/
|
|
/* A = P[X + packet head] */
|
|
s[i] = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B);
|
|
s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
|
|
i++;
|
|
/* MEM[reg2] = A */
|
|
s[i] = new_stmt(cstate, BPF_ST);
|
|
s[i]->s.k = reg2;
|
|
i++;
|
|
/* A = P[X + packet head + 1]; */
|
|
s[i] = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B);
|
|
s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + 1;
|
|
i++;
|
|
/* A += 1 */
|
|
s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
|
|
s[i]->s.k = 1;
|
|
i++;
|
|
/* A *= 8 */
|
|
s[i] = new_stmt(cstate, BPF_ALU|BPF_MUL|BPF_K);
|
|
s[i]->s.k = 8;
|
|
i++;
|
|
/* A += X */
|
|
s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X);
|
|
s[i]->s.k = 0;
|
|
i++;
|
|
/* X = A; */
|
|
s[i] = new_stmt(cstate, BPF_MISC|BPF_TAX);
|
|
i++;
|
|
/* A = MEM[reg2] */
|
|
s[i] = new_stmt(cstate, BPF_LD|BPF_MEM);
|
|
s[i]->s.k = reg2;
|
|
i++;
|
|
|
|
/* goto again; (must use BPF_JA for backward jump) */
|
|
s[i] = new_stmt(cstate, BPF_JMP|BPF_JA);
|
|
s[i]->s.k = again - i - 1;
|
|
s[i - 1]->s.jf = s[i];
|
|
i++;
|
|
|
|
/* fixup */
|
|
for (j = v6start; j <= v6end; j++)
|
|
s[j]->s.jt = s[v6advance];
|
|
} else {
|
|
/* nop */
|
|
s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
|
|
s[i]->s.k = 0;
|
|
s[fix2]->s.jf = s[i];
|
|
i++;
|
|
}
|
|
|
|
/* ahcheck: */
|
|
ahcheck = i;
|
|
/* if (A == IPPROTO_AH) then fall through; else goto end; */
|
|
s[i] = new_stmt(cstate, BPF_JMP|BPF_JEQ|BPF_K);
|
|
s[i]->s.jt = NULL; /*later*/
|
|
s[i]->s.jf = NULL; /*later*/
|
|
s[i]->s.k = IPPROTO_AH;
|
|
if (fix3)
|
|
s[fix3]->s.jf = s[ahcheck];
|
|
fix4 = i;
|
|
i++;
|
|
|
|
/*
|
|
* in short,
|
|
* A = P[X];
|
|
* X = X + (P[X + 1] + 2) * 4;
|
|
*/
|
|
/* A = X */
|
|
s[i - 1]->s.jt = s[i] = new_stmt(cstate, BPF_MISC|BPF_TXA);
|
|
i++;
|
|
/* A = P[X + packet head]; */
|
|
s[i] = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B);
|
|
s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
|
|
i++;
|
|
/* MEM[reg2] = A */
|
|
s[i] = new_stmt(cstate, BPF_ST);
|
|
s[i]->s.k = reg2;
|
|
i++;
|
|
/* A = X */
|
|
s[i - 1]->s.jt = s[i] = new_stmt(cstate, BPF_MISC|BPF_TXA);
|
|
i++;
|
|
/* A += 1 */
|
|
s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
|
|
s[i]->s.k = 1;
|
|
i++;
|
|
/* X = A */
|
|
s[i] = new_stmt(cstate, BPF_MISC|BPF_TAX);
|
|
i++;
|
|
/* A = P[X + packet head] */
|
|
s[i] = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B);
|
|
s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
|
|
i++;
|
|
/* A += 2 */
|
|
s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
|
|
s[i]->s.k = 2;
|
|
i++;
|
|
/* A *= 4 */
|
|
s[i] = new_stmt(cstate, BPF_ALU|BPF_MUL|BPF_K);
|
|
s[i]->s.k = 4;
|
|
i++;
|
|
/* X = A; */
|
|
s[i] = new_stmt(cstate, BPF_MISC|BPF_TAX);
|
|
i++;
|
|
/* A = MEM[reg2] */
|
|
s[i] = new_stmt(cstate, BPF_LD|BPF_MEM);
|
|
s[i]->s.k = reg2;
|
|
i++;
|
|
|
|
/* goto again; (must use BPF_JA for backward jump) */
|
|
s[i] = new_stmt(cstate, BPF_JMP|BPF_JA);
|
|
s[i]->s.k = again - i - 1;
|
|
i++;
|
|
|
|
/* end: nop */
|
|
end = i;
|
|
s[i] = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
|
|
s[i]->s.k = 0;
|
|
s[fix2]->s.jt = s[end];
|
|
s[fix4]->s.jf = s[end];
|
|
s[fix5]->s.jt = s[end];
|
|
i++;
|
|
|
|
/*
|
|
* make slist chain
|
|
*/
|
|
max = i;
|
|
for (i = 0; i < max - 1; i++)
|
|
s[i]->next = s[i + 1];
|
|
s[max - 1]->next = NULL;
|
|
|
|
/*
|
|
* emit final check
|
|
*/
|
|
b = new_block(cstate, JMP(BPF_JEQ));
|
|
b->stmts = s[1]; /*remember, s[0] is dummy*/
|
|
b->s.k = v;
|
|
|
|
free_reg(cstate, reg2);
|
|
|
|
gen_and(b0, b);
|
|
return b;
|
|
#endif
|
|
}
|
|
|
|
static struct block *
|
|
gen_check_802_11_data_frame(compiler_state_t *cstate)
|
|
{
|
|
struct slist *s;
|
|
struct block *b0, *b1;
|
|
|
|
/*
|
|
* A data frame has the 0x08 bit (b3) in the frame control field set
|
|
* and the 0x04 bit (b2) clear.
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
|
|
b0 = new_block(cstate, JMP(BPF_JSET));
|
|
b0->s.k = 0x08;
|
|
b0->stmts = s;
|
|
|
|
s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
|
|
b1 = new_block(cstate, JMP(BPF_JSET));
|
|
b1->s.k = 0x04;
|
|
b1->stmts = s;
|
|
gen_not(b1);
|
|
|
|
gen_and(b1, b0);
|
|
|
|
return b0;
|
|
}
|
|
|
|
/*
|
|
* Generate code that checks whether the packet is a packet for protocol
|
|
* <proto> and whether the type field in that protocol's header has
|
|
* the value <v>, e.g. if <proto> is Q_IP, it checks whether it's an
|
|
* IP packet and checks the protocol number in the IP header against <v>.
|
|
*
|
|
* If <proto> is Q_DEFAULT, i.e. just "proto" was specified, it checks
|
|
* against Q_IP and Q_IPV6.
|
|
*/
|
|
static struct block *
|
|
gen_proto(compiler_state_t *cstate, int v, int proto, int dir)
|
|
{
|
|
struct block *b0, *b1;
|
|
#ifndef CHASE_CHAIN
|
|
struct block *b2;
|
|
#endif
|
|
|
|
if (dir != Q_DEFAULT)
|
|
bpf_error(cstate, "direction applied to 'proto'");
|
|
|
|
switch (proto) {
|
|
case Q_DEFAULT:
|
|
b0 = gen_proto(cstate, v, Q_IP, dir);
|
|
b1 = gen_proto(cstate, v, Q_IPV6, dir);
|
|
gen_or(b0, b1);
|
|
return b1;
|
|
|
|
case Q_LINK:
|
|
return gen_linktype(cstate, v);
|
|
|
|
case Q_IP:
|
|
/*
|
|
* For FDDI, RFC 1188 says that SNAP encapsulation is used,
|
|
* not LLC encapsulation with LLCSAP_IP.
|
|
*
|
|
* For IEEE 802 networks - which includes 802.5 token ring
|
|
* (which is what DLT_IEEE802 means) and 802.11 - RFC 1042
|
|
* says that SNAP encapsulation is used, not LLC encapsulation
|
|
* with LLCSAP_IP.
|
|
*
|
|
* For LLC-encapsulated ATM/"Classical IP", RFC 1483 and
|
|
* RFC 2225 say that SNAP encapsulation is used, not LLC
|
|
* encapsulation with LLCSAP_IP.
|
|
*
|
|
* So we always check for ETHERTYPE_IP.
|
|
*/
|
|
b0 = gen_linktype(cstate, ETHERTYPE_IP);
|
|
#ifndef CHASE_CHAIN
|
|
b1 = gen_cmp(cstate, OR_LINKPL, 9, BPF_B, (bpf_int32)v);
|
|
#else
|
|
b1 = gen_protochain(cstate, v, Q_IP);
|
|
#endif
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case Q_ARP:
|
|
bpf_error(cstate, "arp does not encapsulate another protocol");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_RARP:
|
|
bpf_error(cstate, "rarp does not encapsulate another protocol");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_SCTP:
|
|
bpf_error(cstate, "'sctp proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_TCP:
|
|
bpf_error(cstate, "'tcp proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_UDP:
|
|
bpf_error(cstate, "'udp proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ICMP:
|
|
bpf_error(cstate, "'icmp proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_IGMP:
|
|
bpf_error(cstate, "'igmp proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_IGRP:
|
|
bpf_error(cstate, "'igrp proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ATALK:
|
|
bpf_error(cstate, "AppleTalk encapsulation is not specifiable");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_DECNET:
|
|
bpf_error(cstate, "DECNET encapsulation is not specifiable");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_LAT:
|
|
bpf_error(cstate, "LAT does not encapsulate another protocol");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_SCA:
|
|
bpf_error(cstate, "SCA does not encapsulate another protocol");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_MOPRC:
|
|
bpf_error(cstate, "MOPRC does not encapsulate another protocol");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_MOPDL:
|
|
bpf_error(cstate, "MOPDL does not encapsulate another protocol");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_IPV6:
|
|
b0 = gen_linktype(cstate, ETHERTYPE_IPV6);
|
|
#ifndef CHASE_CHAIN
|
|
/*
|
|
* Also check for a fragment header before the final
|
|
* header.
|
|
*/
|
|
b2 = gen_cmp(cstate, OR_LINKPL, 6, BPF_B, IPPROTO_FRAGMENT);
|
|
b1 = gen_cmp(cstate, OR_LINKPL, 40, BPF_B, (bpf_int32)v);
|
|
gen_and(b2, b1);
|
|
b2 = gen_cmp(cstate, OR_LINKPL, 6, BPF_B, (bpf_int32)v);
|
|
gen_or(b2, b1);
|
|
#else
|
|
b1 = gen_protochain(cstate, v, Q_IPV6);
|
|
#endif
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case Q_ICMPV6:
|
|
bpf_error(cstate, "'icmp6 proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_AH:
|
|
bpf_error(cstate, "'ah proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ESP:
|
|
bpf_error(cstate, "'ah proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_PIM:
|
|
bpf_error(cstate, "'pim proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_VRRP:
|
|
bpf_error(cstate, "'vrrp proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_AARP:
|
|
bpf_error(cstate, "'aarp proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ISO:
|
|
switch (cstate->linktype) {
|
|
|
|
case DLT_FRELAY:
|
|
/*
|
|
* Frame Relay packets typically have an OSI
|
|
* NLPID at the beginning; "gen_linktype(cstate, LLCSAP_ISONS)"
|
|
* generates code to check for all the OSI
|
|
* NLPIDs, so calling it and then adding a check
|
|
* for the particular NLPID for which we're
|
|
* looking is bogus, as we can just check for
|
|
* the NLPID.
|
|
*
|
|
* What we check for is the NLPID and a frame
|
|
* control field value of UI, i.e. 0x03 followed
|
|
* by the NLPID.
|
|
*
|
|
* XXX - assumes a 2-byte Frame Relay header with
|
|
* DLCI and flags. What if the address is longer?
|
|
*
|
|
* XXX - what about SNAP-encapsulated frames?
|
|
*/
|
|
return gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, (0x03<<8) | v);
|
|
/*NOTREACHED*/
|
|
|
|
case DLT_C_HDLC:
|
|
/*
|
|
* Cisco uses an Ethertype lookalike - for OSI,
|
|
* it's 0xfefe.
|
|
*/
|
|
b0 = gen_linktype(cstate, LLCSAP_ISONS<<8 | LLCSAP_ISONS);
|
|
/* OSI in C-HDLC is stuffed with a fudge byte */
|
|
b1 = gen_cmp(cstate, OR_LINKPL_NOSNAP, 1, BPF_B, (long)v);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
default:
|
|
b0 = gen_linktype(cstate, LLCSAP_ISONS);
|
|
b1 = gen_cmp(cstate, OR_LINKPL_NOSNAP, 0, BPF_B, (long)v);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
|
|
case Q_ESIS:
|
|
bpf_error(cstate, "'esis proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ISIS:
|
|
b0 = gen_proto(cstate, ISO10589_ISIS, Q_ISO, Q_DEFAULT);
|
|
/*
|
|
* 4 is the offset of the PDU type relative to the IS-IS
|
|
* header.
|
|
*/
|
|
b1 = gen_cmp(cstate, OR_LINKPL_NOSNAP, 4, BPF_B, (long)v);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case Q_CLNP:
|
|
bpf_error(cstate, "'clnp proto' is not supported");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_STP:
|
|
bpf_error(cstate, "'stp proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_IPX:
|
|
bpf_error(cstate, "'ipx proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_NETBEUI:
|
|
bpf_error(cstate, "'netbeui proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ISIS_L1:
|
|
bpf_error(cstate, "'l1 proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ISIS_L2:
|
|
bpf_error(cstate, "'l2 proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ISIS_IIH:
|
|
bpf_error(cstate, "'iih proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ISIS_SNP:
|
|
bpf_error(cstate, "'snp proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ISIS_CSNP:
|
|
bpf_error(cstate, "'csnp proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ISIS_PSNP:
|
|
bpf_error(cstate, "'psnp proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ISIS_LSP:
|
|
bpf_error(cstate, "'lsp proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_RADIO:
|
|
bpf_error(cstate, "'radio proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_CARP:
|
|
bpf_error(cstate, "'carp proto' is bogus");
|
|
/*NOTREACHED*/
|
|
|
|
default:
|
|
abort();
|
|
/*NOTREACHED*/
|
|
}
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
struct block *
|
|
gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
|
|
{
|
|
int proto = q.proto;
|
|
int dir = q.dir;
|
|
int tproto;
|
|
u_char *eaddr;
|
|
bpf_u_int32 mask, addr;
|
|
struct addrinfo *res, *res0;
|
|
struct sockaddr_in *sin4;
|
|
#ifdef INET6
|
|
int tproto6;
|
|
struct sockaddr_in6 *sin6;
|
|
struct in6_addr mask128;
|
|
#endif /*INET6*/
|
|
struct block *b, *tmp;
|
|
int port, real_proto;
|
|
int port1, port2;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
switch (q.addr) {
|
|
|
|
case Q_NET:
|
|
addr = pcap_nametonetaddr(name);
|
|
if (addr == 0)
|
|
bpf_error(cstate, "unknown network '%s'", name);
|
|
/* Left justify network addr and calculate its network mask */
|
|
mask = 0xffffffff;
|
|
while (addr && (addr & 0xff000000) == 0) {
|
|
addr <<= 8;
|
|
mask <<= 8;
|
|
}
|
|
return gen_host(cstate, addr, mask, proto, dir, q.addr);
|
|
|
|
case Q_DEFAULT:
|
|
case Q_HOST:
|
|
if (proto == Q_LINK) {
|
|
switch (cstate->linktype) {
|
|
|
|
case DLT_EN10MB:
|
|
case DLT_NETANALYZER:
|
|
case DLT_NETANALYZER_TRANSPARENT:
|
|
eaddr = pcap_ether_hostton(name);
|
|
if (eaddr == NULL)
|
|
bpf_error(cstate,
|
|
"unknown ether host '%s'", name);
|
|
tmp = gen_prevlinkhdr_check(cstate);
|
|
b = gen_ehostop(cstate, eaddr, dir);
|
|
if (tmp != NULL)
|
|
gen_and(tmp, b);
|
|
free(eaddr);
|
|
return b;
|
|
|
|
case DLT_FDDI:
|
|
eaddr = pcap_ether_hostton(name);
|
|
if (eaddr == NULL)
|
|
bpf_error(cstate,
|
|
"unknown FDDI host '%s'", name);
|
|
b = gen_fhostop(cstate, eaddr, dir);
|
|
free(eaddr);
|
|
return b;
|
|
|
|
case DLT_IEEE802:
|
|
eaddr = pcap_ether_hostton(name);
|
|
if (eaddr == NULL)
|
|
bpf_error(cstate,
|
|
"unknown token ring host '%s'", name);
|
|
b = gen_thostop(cstate, eaddr, dir);
|
|
free(eaddr);
|
|
return b;
|
|
|
|
case DLT_IEEE802_11:
|
|
case DLT_PRISM_HEADER:
|
|
case DLT_IEEE802_11_RADIO_AVS:
|
|
case DLT_IEEE802_11_RADIO:
|
|
case DLT_PPI:
|
|
eaddr = pcap_ether_hostton(name);
|
|
if (eaddr == NULL)
|
|
bpf_error(cstate,
|
|
"unknown 802.11 host '%s'", name);
|
|
b = gen_wlanhostop(cstate, eaddr, dir);
|
|
free(eaddr);
|
|
return b;
|
|
|
|
case DLT_IP_OVER_FC:
|
|
eaddr = pcap_ether_hostton(name);
|
|
if (eaddr == NULL)
|
|
bpf_error(cstate,
|
|
"unknown Fibre Channel host '%s'", name);
|
|
b = gen_ipfchostop(cstate, eaddr, dir);
|
|
free(eaddr);
|
|
return b;
|
|
}
|
|
|
|
bpf_error(cstate, "only ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel supports link-level host name");
|
|
} else if (proto == Q_DECNET) {
|
|
unsigned short dn_addr;
|
|
|
|
if (!__pcap_nametodnaddr(name, &dn_addr)) {
|
|
#ifdef DECNETLIB
|
|
bpf_error(cstate, "unknown decnet host name '%s'\n", name);
|
|
#else
|
|
bpf_error(cstate, "decnet name support not included, '%s' cannot be translated\n",
|
|
name);
|
|
#endif
|
|
}
|
|
/*
|
|
* I don't think DECNET hosts can be multihomed, so
|
|
* there is no need to build up a list of addresses
|
|
*/
|
|
return (gen_host(cstate, dn_addr, 0, proto, dir, q.addr));
|
|
} else {
|
|
#ifdef INET6
|
|
memset(&mask128, 0xff, sizeof(mask128));
|
|
#endif
|
|
res0 = res = pcap_nametoaddrinfo(name);
|
|
if (res == NULL)
|
|
bpf_error(cstate, "unknown host '%s'", name);
|
|
cstate->ai = res;
|
|
b = tmp = NULL;
|
|
tproto = proto;
|
|
#ifdef INET6
|
|
tproto6 = proto;
|
|
#endif
|
|
if (cstate->off_linktype.constant_part == OFFSET_NOT_SET &&
|
|
tproto == Q_DEFAULT) {
|
|
tproto = Q_IP;
|
|
#ifdef INET6
|
|
tproto6 = Q_IPV6;
|
|
#endif
|
|
}
|
|
for (res = res0; res; res = res->ai_next) {
|
|
switch (res->ai_family) {
|
|
case AF_INET:
|
|
#ifdef INET6
|
|
if (tproto == Q_IPV6)
|
|
continue;
|
|
#endif
|
|
|
|
sin4 = (struct sockaddr_in *)
|
|
res->ai_addr;
|
|
tmp = gen_host(cstate, ntohl(sin4->sin_addr.s_addr),
|
|
0xffffffff, tproto, dir, q.addr);
|
|
break;
|
|
#ifdef INET6
|
|
case AF_INET6:
|
|
if (tproto6 == Q_IP)
|
|
continue;
|
|
|
|
sin6 = (struct sockaddr_in6 *)
|
|
res->ai_addr;
|
|
tmp = gen_host6(cstate, &sin6->sin6_addr,
|
|
&mask128, tproto6, dir, q.addr);
|
|
break;
|
|
#endif
|
|
default:
|
|
continue;
|
|
}
|
|
if (b)
|
|
gen_or(b, tmp);
|
|
b = tmp;
|
|
}
|
|
cstate->ai = NULL;
|
|
freeaddrinfo(res0);
|
|
if (b == NULL) {
|
|
bpf_error(cstate, "unknown host '%s'%s", name,
|
|
(proto == Q_DEFAULT)
|
|
? ""
|
|
: " for specified address family");
|
|
}
|
|
return b;
|
|
}
|
|
|
|
case Q_PORT:
|
|
if (proto != Q_DEFAULT &&
|
|
proto != Q_UDP && proto != Q_TCP && proto != Q_SCTP)
|
|
bpf_error(cstate, "illegal qualifier of 'port'");
|
|
if (pcap_nametoport(name, &port, &real_proto) == 0)
|
|
bpf_error(cstate, "unknown port '%s'", name);
|
|
if (proto == Q_UDP) {
|
|
if (real_proto == IPPROTO_TCP)
|
|
bpf_error(cstate, "port '%s' is tcp", name);
|
|
else if (real_proto == IPPROTO_SCTP)
|
|
bpf_error(cstate, "port '%s' is sctp", name);
|
|
else
|
|
/* override PROTO_UNDEF */
|
|
real_proto = IPPROTO_UDP;
|
|
}
|
|
if (proto == Q_TCP) {
|
|
if (real_proto == IPPROTO_UDP)
|
|
bpf_error(cstate, "port '%s' is udp", name);
|
|
|
|
else if (real_proto == IPPROTO_SCTP)
|
|
bpf_error(cstate, "port '%s' is sctp", name);
|
|
else
|
|
/* override PROTO_UNDEF */
|
|
real_proto = IPPROTO_TCP;
|
|
}
|
|
if (proto == Q_SCTP) {
|
|
if (real_proto == IPPROTO_UDP)
|
|
bpf_error(cstate, "port '%s' is udp", name);
|
|
|
|
else if (real_proto == IPPROTO_TCP)
|
|
bpf_error(cstate, "port '%s' is tcp", name);
|
|
else
|
|
/* override PROTO_UNDEF */
|
|
real_proto = IPPROTO_SCTP;
|
|
}
|
|
if (port < 0)
|
|
bpf_error(cstate, "illegal port number %d < 0", port);
|
|
if (port > 65535)
|
|
bpf_error(cstate, "illegal port number %d > 65535", port);
|
|
b = gen_port(cstate, port, real_proto, dir);
|
|
gen_or(gen_port6(cstate, port, real_proto, dir), b);
|
|
return b;
|
|
|
|
case Q_PORTRANGE:
|
|
if (proto != Q_DEFAULT &&
|
|
proto != Q_UDP && proto != Q_TCP && proto != Q_SCTP)
|
|
bpf_error(cstate, "illegal qualifier of 'portrange'");
|
|
if (pcap_nametoportrange(name, &port1, &port2, &real_proto) == 0)
|
|
bpf_error(cstate, "unknown port in range '%s'", name);
|
|
if (proto == Q_UDP) {
|
|
if (real_proto == IPPROTO_TCP)
|
|
bpf_error(cstate, "port in range '%s' is tcp", name);
|
|
else if (real_proto == IPPROTO_SCTP)
|
|
bpf_error(cstate, "port in range '%s' is sctp", name);
|
|
else
|
|
/* override PROTO_UNDEF */
|
|
real_proto = IPPROTO_UDP;
|
|
}
|
|
if (proto == Q_TCP) {
|
|
if (real_proto == IPPROTO_UDP)
|
|
bpf_error(cstate, "port in range '%s' is udp", name);
|
|
else if (real_proto == IPPROTO_SCTP)
|
|
bpf_error(cstate, "port in range '%s' is sctp", name);
|
|
else
|
|
/* override PROTO_UNDEF */
|
|
real_proto = IPPROTO_TCP;
|
|
}
|
|
if (proto == Q_SCTP) {
|
|
if (real_proto == IPPROTO_UDP)
|
|
bpf_error(cstate, "port in range '%s' is udp", name);
|
|
else if (real_proto == IPPROTO_TCP)
|
|
bpf_error(cstate, "port in range '%s' is tcp", name);
|
|
else
|
|
/* override PROTO_UNDEF */
|
|
real_proto = IPPROTO_SCTP;
|
|
}
|
|
if (port1 < 0)
|
|
bpf_error(cstate, "illegal port number %d < 0", port1);
|
|
if (port1 > 65535)
|
|
bpf_error(cstate, "illegal port number %d > 65535", port1);
|
|
if (port2 < 0)
|
|
bpf_error(cstate, "illegal port number %d < 0", port2);
|
|
if (port2 > 65535)
|
|
bpf_error(cstate, "illegal port number %d > 65535", port2);
|
|
|
|
b = gen_portrange(cstate, port1, port2, real_proto, dir);
|
|
gen_or(gen_portrange6(cstate, port1, port2, real_proto, dir), b);
|
|
return b;
|
|
|
|
case Q_GATEWAY:
|
|
#ifndef INET6
|
|
eaddr = pcap_ether_hostton(name);
|
|
if (eaddr == NULL)
|
|
bpf_error(cstate, "unknown ether host: %s", name);
|
|
|
|
res = pcap_nametoaddrinfo(name);
|
|
cstate->ai = res;
|
|
if (res == NULL)
|
|
bpf_error(cstate, "unknown host '%s'", name);
|
|
b = gen_gateway(cstate, eaddr, res, proto, dir);
|
|
cstate->ai = NULL;
|
|
freeaddrinfo(res);
|
|
if (b == NULL)
|
|
bpf_error(cstate, "unknown host '%s'", name);
|
|
return b;
|
|
#else
|
|
bpf_error(cstate, "'gateway' not supported in this configuration");
|
|
#endif /*INET6*/
|
|
|
|
case Q_PROTO:
|
|
real_proto = lookup_proto(cstate, name, proto);
|
|
if (real_proto >= 0)
|
|
return gen_proto(cstate, real_proto, proto, dir);
|
|
else
|
|
bpf_error(cstate, "unknown protocol: %s", name);
|
|
|
|
case Q_PROTOCHAIN:
|
|
real_proto = lookup_proto(cstate, name, proto);
|
|
if (real_proto >= 0)
|
|
return gen_protochain(cstate, real_proto, proto, dir);
|
|
else
|
|
bpf_error(cstate, "unknown protocol: %s", name);
|
|
|
|
case Q_UNDEF:
|
|
syntax(cstate);
|
|
/*NOTREACHED*/
|
|
}
|
|
abort();
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
struct block *
|
|
gen_mcode(compiler_state_t *cstate, const char *s1, const char *s2,
|
|
unsigned int masklen, struct qual q)
|
|
{
|
|
register int nlen, mlen;
|
|
bpf_u_int32 n, m;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
nlen = __pcap_atoin(s1, &n);
|
|
if (nlen < 0)
|
|
bpf_error(cstate, "invalid IPv4 address '%s'", s1);
|
|
/* Promote short ipaddr */
|
|
n <<= 32 - nlen;
|
|
|
|
if (s2 != NULL) {
|
|
mlen = __pcap_atoin(s2, &m);
|
|
if (mlen < 0)
|
|
bpf_error(cstate, "invalid IPv4 address '%s'", s2);
|
|
/* Promote short ipaddr */
|
|
m <<= 32 - mlen;
|
|
if ((n & ~m) != 0)
|
|
bpf_error(cstate, "non-network bits set in \"%s mask %s\"",
|
|
s1, s2);
|
|
} else {
|
|
/* Convert mask len to mask */
|
|
if (masklen > 32)
|
|
bpf_error(cstate, "mask length must be <= 32");
|
|
if (masklen == 0) {
|
|
/*
|
|
* X << 32 is not guaranteed by C to be 0; it's
|
|
* undefined.
|
|
*/
|
|
m = 0;
|
|
} else
|
|
m = 0xffffffff << (32 - masklen);
|
|
if ((n & ~m) != 0)
|
|
bpf_error(cstate, "non-network bits set in \"%s/%d\"",
|
|
s1, masklen);
|
|
}
|
|
|
|
switch (q.addr) {
|
|
|
|
case Q_NET:
|
|
return gen_host(cstate, n, m, q.proto, q.dir, q.addr);
|
|
|
|
default:
|
|
bpf_error(cstate, "Mask syntax for networks only");
|
|
/*NOTREACHED*/
|
|
}
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
struct block *
|
|
gen_ncode(compiler_state_t *cstate, const char *s, bpf_u_int32 v, struct qual q)
|
|
{
|
|
bpf_u_int32 mask;
|
|
int proto;
|
|
int dir;
|
|
register int vlen;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
proto = q.proto;
|
|
dir = q.dir;
|
|
if (s == NULL)
|
|
vlen = 32;
|
|
else if (q.proto == Q_DECNET) {
|
|
vlen = __pcap_atodn(s, &v);
|
|
if (vlen == 0)
|
|
bpf_error(cstate, "malformed decnet address '%s'", s);
|
|
} else {
|
|
vlen = __pcap_atoin(s, &v);
|
|
if (vlen < 0)
|
|
bpf_error(cstate, "invalid IPv4 address '%s'", s);
|
|
}
|
|
|
|
switch (q.addr) {
|
|
|
|
case Q_DEFAULT:
|
|
case Q_HOST:
|
|
case Q_NET:
|
|
if (proto == Q_DECNET)
|
|
return gen_host(cstate, v, 0, proto, dir, q.addr);
|
|
else if (proto == Q_LINK) {
|
|
bpf_error(cstate, "illegal link layer address");
|
|
} else {
|
|
mask = 0xffffffff;
|
|
if (s == NULL && q.addr == Q_NET) {
|
|
/* Promote short net number */
|
|
while (v && (v & 0xff000000) == 0) {
|
|
v <<= 8;
|
|
mask <<= 8;
|
|
}
|
|
} else {
|
|
/* Promote short ipaddr */
|
|
v <<= 32 - vlen;
|
|
mask <<= 32 - vlen ;
|
|
}
|
|
return gen_host(cstate, v, mask, proto, dir, q.addr);
|
|
}
|
|
|
|
case Q_PORT:
|
|
if (proto == Q_UDP)
|
|
proto = IPPROTO_UDP;
|
|
else if (proto == Q_TCP)
|
|
proto = IPPROTO_TCP;
|
|
else if (proto == Q_SCTP)
|
|
proto = IPPROTO_SCTP;
|
|
else if (proto == Q_DEFAULT)
|
|
proto = PROTO_UNDEF;
|
|
else
|
|
bpf_error(cstate, "illegal qualifier of 'port'");
|
|
|
|
if (v > 65535)
|
|
bpf_error(cstate, "illegal port number %u > 65535", v);
|
|
|
|
{
|
|
struct block *b;
|
|
b = gen_port(cstate, (int)v, proto, dir);
|
|
gen_or(gen_port6(cstate, (int)v, proto, dir), b);
|
|
return b;
|
|
}
|
|
|
|
case Q_PORTRANGE:
|
|
if (proto == Q_UDP)
|
|
proto = IPPROTO_UDP;
|
|
else if (proto == Q_TCP)
|
|
proto = IPPROTO_TCP;
|
|
else if (proto == Q_SCTP)
|
|
proto = IPPROTO_SCTP;
|
|
else if (proto == Q_DEFAULT)
|
|
proto = PROTO_UNDEF;
|
|
else
|
|
bpf_error(cstate, "illegal qualifier of 'portrange'");
|
|
|
|
if (v > 65535)
|
|
bpf_error(cstate, "illegal port number %u > 65535", v);
|
|
|
|
{
|
|
struct block *b;
|
|
b = gen_portrange(cstate, (int)v, (int)v, proto, dir);
|
|
gen_or(gen_portrange6(cstate, (int)v, (int)v, proto, dir), b);
|
|
return b;
|
|
}
|
|
|
|
case Q_GATEWAY:
|
|
bpf_error(cstate, "'gateway' requires a name");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_PROTO:
|
|
return gen_proto(cstate, (int)v, proto, dir);
|
|
|
|
case Q_PROTOCHAIN:
|
|
return gen_protochain(cstate, (int)v, proto, dir);
|
|
|
|
case Q_UNDEF:
|
|
syntax(cstate);
|
|
/*NOTREACHED*/
|
|
|
|
default:
|
|
abort();
|
|
/*NOTREACHED*/
|
|
}
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
#ifdef INET6
|
|
struct block *
|
|
gen_mcode6(compiler_state_t *cstate, const char *s1, const char *s2,
|
|
unsigned int masklen, struct qual q)
|
|
{
|
|
struct addrinfo *res;
|
|
struct in6_addr *addr;
|
|
struct in6_addr mask;
|
|
struct block *b;
|
|
uint32_t *a, *m;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
if (s2)
|
|
bpf_error(cstate, "no mask %s supported", s2);
|
|
|
|
res = pcap_nametoaddrinfo(s1);
|
|
if (!res)
|
|
bpf_error(cstate, "invalid ip6 address %s", s1);
|
|
cstate->ai = res;
|
|
if (res->ai_next)
|
|
bpf_error(cstate, "%s resolved to multiple address", s1);
|
|
addr = &((struct sockaddr_in6 *)res->ai_addr)->sin6_addr;
|
|
|
|
if (sizeof(mask) * 8 < masklen)
|
|
bpf_error(cstate, "mask length must be <= %u", (unsigned int)(sizeof(mask) * 8));
|
|
memset(&mask, 0, sizeof(mask));
|
|
memset(&mask, 0xff, masklen / 8);
|
|
if (masklen % 8) {
|
|
mask.s6_addr[masklen / 8] =
|
|
(0xff << (8 - masklen % 8)) & 0xff;
|
|
}
|
|
|
|
a = (uint32_t *)addr;
|
|
m = (uint32_t *)&mask;
|
|
if ((a[0] & ~m[0]) || (a[1] & ~m[1])
|
|
|| (a[2] & ~m[2]) || (a[3] & ~m[3])) {
|
|
bpf_error(cstate, "non-network bits set in \"%s/%d\"", s1, masklen);
|
|
}
|
|
|
|
switch (q.addr) {
|
|
|
|
case Q_DEFAULT:
|
|
case Q_HOST:
|
|
if (masklen != 128)
|
|
bpf_error(cstate, "Mask syntax for networks only");
|
|
/* FALLTHROUGH */
|
|
|
|
case Q_NET:
|
|
b = gen_host6(cstate, addr, &mask, q.proto, q.dir, q.addr);
|
|
cstate->ai = NULL;
|
|
freeaddrinfo(res);
|
|
return b;
|
|
|
|
default:
|
|
bpf_error(cstate, "invalid qualifier against IPv6 address");
|
|
/*NOTREACHED*/
|
|
}
|
|
}
|
|
#endif /*INET6*/
|
|
|
|
struct block *
|
|
gen_ecode(compiler_state_t *cstate, const char *s, struct qual q)
|
|
{
|
|
struct block *b, *tmp;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) {
|
|
cstate->e = pcap_ether_aton(s);
|
|
if (cstate->e == NULL)
|
|
bpf_error(cstate, "malloc");
|
|
switch (cstate->linktype) {
|
|
case DLT_EN10MB:
|
|
case DLT_NETANALYZER:
|
|
case DLT_NETANALYZER_TRANSPARENT:
|
|
tmp = gen_prevlinkhdr_check(cstate);
|
|
b = gen_ehostop(cstate, cstate->e, (int)q.dir);
|
|
if (tmp != NULL)
|
|
gen_and(tmp, b);
|
|
break;
|
|
case DLT_FDDI:
|
|
b = gen_fhostop(cstate, cstate->e, (int)q.dir);
|
|
break;
|
|
case DLT_IEEE802:
|
|
b = gen_thostop(cstate, cstate->e, (int)q.dir);
|
|
break;
|
|
case DLT_IEEE802_11:
|
|
case DLT_PRISM_HEADER:
|
|
case DLT_IEEE802_11_RADIO_AVS:
|
|
case DLT_IEEE802_11_RADIO:
|
|
case DLT_PPI:
|
|
b = gen_wlanhostop(cstate, cstate->e, (int)q.dir);
|
|
break;
|
|
case DLT_IP_OVER_FC:
|
|
b = gen_ipfchostop(cstate, cstate->e, (int)q.dir);
|
|
break;
|
|
default:
|
|
free(cstate->e);
|
|
cstate->e = NULL;
|
|
bpf_error(cstate, "ethernet addresses supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
|
|
/*NOTREACHED*/
|
|
}
|
|
free(cstate->e);
|
|
cstate->e = NULL;
|
|
return (b);
|
|
}
|
|
bpf_error(cstate, "ethernet address used in non-ether expression");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
void
|
|
sappend(struct slist *s0, struct slist *s1)
|
|
{
|
|
/*
|
|
* This is definitely not the best way to do this, but the
|
|
* lists will rarely get long.
|
|
*/
|
|
while (s0->next)
|
|
s0 = s0->next;
|
|
s0->next = s1;
|
|
}
|
|
|
|
static struct slist *
|
|
xfer_to_x(compiler_state_t *cstate, struct arth *a)
|
|
{
|
|
struct slist *s;
|
|
|
|
s = new_stmt(cstate, BPF_LDX|BPF_MEM);
|
|
s->s.k = a->regno;
|
|
return s;
|
|
}
|
|
|
|
static struct slist *
|
|
xfer_to_a(compiler_state_t *cstate, struct arth *a)
|
|
{
|
|
struct slist *s;
|
|
|
|
s = new_stmt(cstate, BPF_LD|BPF_MEM);
|
|
s->s.k = a->regno;
|
|
return s;
|
|
}
|
|
|
|
/*
|
|
* Modify "index" to use the value stored into its register as an
|
|
* offset relative to the beginning of the header for the protocol
|
|
* "proto", and allocate a register and put an item "size" bytes long
|
|
* (1, 2, or 4) at that offset into that register, making it the register
|
|
* for "index".
|
|
*/
|
|
static struct arth *
|
|
gen_load_internal(compiler_state_t *cstate, int proto, struct arth *inst, int size)
|
|
{
|
|
struct slist *s, *tmp;
|
|
struct block *b;
|
|
int regno = alloc_reg(cstate);
|
|
|
|
free_reg(cstate, inst->regno);
|
|
switch (size) {
|
|
|
|
default:
|
|
bpf_error(cstate, "data size must be 1, 2, or 4");
|
|
|
|
case 1:
|
|
size = BPF_B;
|
|
break;
|
|
|
|
case 2:
|
|
size = BPF_H;
|
|
break;
|
|
|
|
case 4:
|
|
size = BPF_W;
|
|
break;
|
|
}
|
|
switch (proto) {
|
|
default:
|
|
bpf_error(cstate, "unsupported index operation");
|
|
|
|
case Q_RADIO:
|
|
/*
|
|
* The offset is relative to the beginning of the packet
|
|
* data, if we have a radio header. (If we don't, this
|
|
* is an error.)
|
|
*/
|
|
if (cstate->linktype != DLT_IEEE802_11_RADIO_AVS &&
|
|
cstate->linktype != DLT_IEEE802_11_RADIO &&
|
|
cstate->linktype != DLT_PRISM_HEADER)
|
|
bpf_error(cstate, "radio information not present in capture");
|
|
|
|
/*
|
|
* Load into the X register the offset computed into the
|
|
* register specified by "index".
|
|
*/
|
|
s = xfer_to_x(cstate, inst);
|
|
|
|
/*
|
|
* Load the item at that offset.
|
|
*/
|
|
tmp = new_stmt(cstate, BPF_LD|BPF_IND|size);
|
|
sappend(s, tmp);
|
|
sappend(inst->s, s);
|
|
break;
|
|
|
|
case Q_LINK:
|
|
/*
|
|
* The offset is relative to the beginning of
|
|
* the link-layer header.
|
|
*
|
|
* XXX - what about ATM LANE? Should the index be
|
|
* relative to the beginning of the AAL5 frame, so
|
|
* that 0 refers to the beginning of the LE Control
|
|
* field, or relative to the beginning of the LAN
|
|
* frame, so that 0 refers, for Ethernet LANE, to
|
|
* the beginning of the destination address?
|
|
*/
|
|
s = gen_abs_offset_varpart(cstate, &cstate->off_linkhdr);
|
|
|
|
/*
|
|
* If "s" is non-null, it has code to arrange that the
|
|
* X register contains the length of the prefix preceding
|
|
* the link-layer header. Add to it the offset computed
|
|
* into the register specified by "index", and move that
|
|
* into the X register. Otherwise, just load into the X
|
|
* register the offset computed into the register specified
|
|
* by "index".
|
|
*/
|
|
if (s != NULL) {
|
|
sappend(s, xfer_to_a(cstate, inst));
|
|
sappend(s, new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X));
|
|
sappend(s, new_stmt(cstate, BPF_MISC|BPF_TAX));
|
|
} else
|
|
s = xfer_to_x(cstate, inst);
|
|
|
|
/*
|
|
* Load the item at the sum of the offset we've put in the
|
|
* X register and the offset of the start of the link
|
|
* layer header (which is 0 if the radio header is
|
|
* variable-length; that header length is what we put
|
|
* into the X register and then added to the index).
|
|
*/
|
|
tmp = new_stmt(cstate, BPF_LD|BPF_IND|size);
|
|
tmp->s.k = cstate->off_linkhdr.constant_part;
|
|
sappend(s, tmp);
|
|
sappend(inst->s, s);
|
|
break;
|
|
|
|
case Q_IP:
|
|
case Q_ARP:
|
|
case Q_RARP:
|
|
case Q_ATALK:
|
|
case Q_DECNET:
|
|
case Q_SCA:
|
|
case Q_LAT:
|
|
case Q_MOPRC:
|
|
case Q_MOPDL:
|
|
case Q_IPV6:
|
|
/*
|
|
* The offset is relative to the beginning of
|
|
* the network-layer header.
|
|
* XXX - are there any cases where we want
|
|
* cstate->off_nl_nosnap?
|
|
*/
|
|
s = gen_abs_offset_varpart(cstate, &cstate->off_linkpl);
|
|
|
|
/*
|
|
* If "s" is non-null, it has code to arrange that the
|
|
* X register contains the variable part of the offset
|
|
* of the link-layer payload. Add to it the offset
|
|
* computed into the register specified by "index",
|
|
* and move that into the X register. Otherwise, just
|
|
* load into the X register the offset computed into
|
|
* the register specified by "index".
|
|
*/
|
|
if (s != NULL) {
|
|
sappend(s, xfer_to_a(cstate, inst));
|
|
sappend(s, new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X));
|
|
sappend(s, new_stmt(cstate, BPF_MISC|BPF_TAX));
|
|
} else
|
|
s = xfer_to_x(cstate, inst);
|
|
|
|
/*
|
|
* Load the item at the sum of the offset we've put in the
|
|
* X register, the offset of the start of the network
|
|
* layer header from the beginning of the link-layer
|
|
* payload, and the constant part of the offset of the
|
|
* start of the link-layer payload.
|
|
*/
|
|
tmp = new_stmt(cstate, BPF_LD|BPF_IND|size);
|
|
tmp->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
|
|
sappend(s, tmp);
|
|
sappend(inst->s, s);
|
|
|
|
/*
|
|
* Do the computation only if the packet contains
|
|
* the protocol in question.
|
|
*/
|
|
b = gen_proto_abbrev_internal(cstate, proto);
|
|
if (inst->b)
|
|
gen_and(inst->b, b);
|
|
inst->b = b;
|
|
break;
|
|
|
|
case Q_SCTP:
|
|
case Q_TCP:
|
|
case Q_UDP:
|
|
case Q_ICMP:
|
|
case Q_IGMP:
|
|
case Q_IGRP:
|
|
case Q_PIM:
|
|
case Q_VRRP:
|
|
case Q_CARP:
|
|
/*
|
|
* The offset is relative to the beginning of
|
|
* the transport-layer header.
|
|
*
|
|
* Load the X register with the length of the IPv4 header
|
|
* (plus the offset of the link-layer header, if it's
|
|
* a variable-length header), in bytes.
|
|
*
|
|
* XXX - are there any cases where we want
|
|
* cstate->off_nl_nosnap?
|
|
* XXX - we should, if we're built with
|
|
* IPv6 support, generate code to load either
|
|
* IPv4, IPv6, or both, as appropriate.
|
|
*/
|
|
s = gen_loadx_iphdrlen(cstate);
|
|
|
|
/*
|
|
* The X register now contains the sum of the variable
|
|
* part of the offset of the link-layer payload and the
|
|
* length of the network-layer header.
|
|
*
|
|
* Load into the A register the offset relative to
|
|
* the beginning of the transport layer header,
|
|
* add the X register to that, move that to the
|
|
* X register, and load with an offset from the
|
|
* X register equal to the sum of the constant part of
|
|
* the offset of the link-layer payload and the offset,
|
|
* relative to the beginning of the link-layer payload,
|
|
* of the network-layer header.
|
|
*/
|
|
sappend(s, xfer_to_a(cstate, inst));
|
|
sappend(s, new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X));
|
|
sappend(s, new_stmt(cstate, BPF_MISC|BPF_TAX));
|
|
sappend(s, tmp = new_stmt(cstate, BPF_LD|BPF_IND|size));
|
|
tmp->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
|
|
sappend(inst->s, s);
|
|
|
|
/*
|
|
* Do the computation only if the packet contains
|
|
* the protocol in question - which is true only
|
|
* if this is an IP datagram and is the first or
|
|
* only fragment of that datagram.
|
|
*/
|
|
gen_and(gen_proto_abbrev_internal(cstate, proto), b = gen_ipfrag(cstate));
|
|
if (inst->b)
|
|
gen_and(inst->b, b);
|
|
gen_and(gen_proto_abbrev_internal(cstate, Q_IP), b);
|
|
inst->b = b;
|
|
break;
|
|
case Q_ICMPV6:
|
|
/*
|
|
* Do the computation only if the packet contains
|
|
* the protocol in question.
|
|
*/
|
|
b = gen_proto_abbrev_internal(cstate, Q_IPV6);
|
|
if (inst->b) {
|
|
gen_and(inst->b, b);
|
|
}
|
|
inst->b = b;
|
|
|
|
/*
|
|
* Check if we have an icmp6 next header
|
|
*/
|
|
b = gen_cmp(cstate, OR_LINKPL, 6, BPF_B, 58);
|
|
if (inst->b) {
|
|
gen_and(inst->b, b);
|
|
}
|
|
inst->b = b;
|
|
|
|
|
|
s = gen_abs_offset_varpart(cstate, &cstate->off_linkpl);
|
|
/*
|
|
* If "s" is non-null, it has code to arrange that the
|
|
* X register contains the variable part of the offset
|
|
* of the link-layer payload. Add to it the offset
|
|
* computed into the register specified by "index",
|
|
* and move that into the X register. Otherwise, just
|
|
* load into the X register the offset computed into
|
|
* the register specified by "index".
|
|
*/
|
|
if (s != NULL) {
|
|
sappend(s, xfer_to_a(cstate, inst));
|
|
sappend(s, new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X));
|
|
sappend(s, new_stmt(cstate, BPF_MISC|BPF_TAX));
|
|
} else {
|
|
s = xfer_to_x(cstate, inst);
|
|
}
|
|
|
|
/*
|
|
* Load the item at the sum of the offset we've put in the
|
|
* X register, the offset of the start of the network
|
|
* layer header from the beginning of the link-layer
|
|
* payload, and the constant part of the offset of the
|
|
* start of the link-layer payload.
|
|
*/
|
|
tmp = new_stmt(cstate, BPF_LD|BPF_IND|size);
|
|
tmp->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + 40;
|
|
|
|
sappend(s, tmp);
|
|
sappend(inst->s, s);
|
|
|
|
break;
|
|
}
|
|
inst->regno = regno;
|
|
s = new_stmt(cstate, BPF_ST);
|
|
s->s.k = regno;
|
|
sappend(inst->s, s);
|
|
|
|
return inst;
|
|
}
|
|
|
|
struct arth *
|
|
gen_load(compiler_state_t *cstate, int proto, struct arth *inst, int size)
|
|
{
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
return gen_load_internal(cstate, proto, inst, size);
|
|
}
|
|
|
|
static struct block *
|
|
gen_relation_internal(compiler_state_t *cstate, int code, struct arth *a0,
|
|
struct arth *a1, int reversed)
|
|
{
|
|
struct slist *s0, *s1, *s2;
|
|
struct block *b, *tmp;
|
|
|
|
s0 = xfer_to_x(cstate, a1);
|
|
s1 = xfer_to_a(cstate, a0);
|
|
if (code == BPF_JEQ) {
|
|
s2 = new_stmt(cstate, BPF_ALU|BPF_SUB|BPF_X);
|
|
b = new_block(cstate, JMP(code));
|
|
sappend(s1, s2);
|
|
}
|
|
else
|
|
b = new_block(cstate, BPF_JMP|code|BPF_X);
|
|
if (reversed)
|
|
gen_not(b);
|
|
|
|
sappend(s0, s1);
|
|
sappend(a1->s, s0);
|
|
sappend(a0->s, a1->s);
|
|
|
|
b->stmts = a0->s;
|
|
|
|
free_reg(cstate, a0->regno);
|
|
free_reg(cstate, a1->regno);
|
|
|
|
/* 'and' together protocol checks */
|
|
if (a0->b) {
|
|
if (a1->b) {
|
|
gen_and(a0->b, tmp = a1->b);
|
|
}
|
|
else
|
|
tmp = a0->b;
|
|
} else
|
|
tmp = a1->b;
|
|
|
|
if (tmp)
|
|
gen_and(tmp, b);
|
|
|
|
return b;
|
|
}
|
|
|
|
struct block *
|
|
gen_relation(compiler_state_t *cstate, int code, struct arth *a0,
|
|
struct arth *a1, int reversed)
|
|
{
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
return gen_relation_internal(cstate, code, a0, a1, reversed);
|
|
}
|
|
|
|
struct arth *
|
|
gen_loadlen(compiler_state_t *cstate)
|
|
{
|
|
int regno;
|
|
struct arth *a;
|
|
struct slist *s;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
regno = alloc_reg(cstate);
|
|
a = (struct arth *)newchunk(cstate, sizeof(*a));
|
|
s = new_stmt(cstate, BPF_LD|BPF_LEN);
|
|
s->next = new_stmt(cstate, BPF_ST);
|
|
s->next->s.k = regno;
|
|
a->s = s;
|
|
a->regno = regno;
|
|
|
|
return a;
|
|
}
|
|
|
|
static struct arth *
|
|
gen_loadi_internal(compiler_state_t *cstate, int val)
|
|
{
|
|
struct arth *a;
|
|
struct slist *s;
|
|
int reg;
|
|
|
|
a = (struct arth *)newchunk(cstate, sizeof(*a));
|
|
|
|
reg = alloc_reg(cstate);
|
|
|
|
s = new_stmt(cstate, BPF_LD|BPF_IMM);
|
|
s->s.k = val;
|
|
s->next = new_stmt(cstate, BPF_ST);
|
|
s->next->s.k = reg;
|
|
a->s = s;
|
|
a->regno = reg;
|
|
|
|
return a;
|
|
}
|
|
|
|
struct arth *
|
|
gen_loadi(compiler_state_t *cstate, int val)
|
|
{
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
return gen_loadi_internal(cstate, val);
|
|
}
|
|
|
|
/*
|
|
* The a_arg dance is to avoid annoying whining by compilers that
|
|
* a might be clobbered by longjmp - yeah, it might, but *WHO CARES*?
|
|
* It's not *used* after setjmp returns.
|
|
*/
|
|
struct arth *
|
|
gen_neg(compiler_state_t *cstate, struct arth *a_arg)
|
|
{
|
|
struct arth *a = a_arg;
|
|
struct slist *s;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
s = xfer_to_a(cstate, a);
|
|
sappend(a->s, s);
|
|
s = new_stmt(cstate, BPF_ALU|BPF_NEG);
|
|
s->s.k = 0;
|
|
sappend(a->s, s);
|
|
s = new_stmt(cstate, BPF_ST);
|
|
s->s.k = a->regno;
|
|
sappend(a->s, s);
|
|
|
|
return a;
|
|
}
|
|
|
|
/*
|
|
* The a0_arg dance is to avoid annoying whining by compilers that
|
|
* a0 might be clobbered by longjmp - yeah, it might, but *WHO CARES*?
|
|
* It's not *used* after setjmp returns.
|
|
*/
|
|
struct arth *
|
|
gen_arth(compiler_state_t *cstate, int code, struct arth *a0_arg,
|
|
struct arth *a1)
|
|
{
|
|
struct arth *a0 = a0_arg;
|
|
struct slist *s0, *s1, *s2;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
/*
|
|
* Disallow division by, or modulus by, zero; we do this here
|
|
* so that it gets done even if the optimizer is disabled.
|
|
*
|
|
* Also disallow shifts by a value greater than 31; we do this
|
|
* here, for the same reason.
|
|
*/
|
|
if (code == BPF_DIV) {
|
|
if (a1->s->s.code == (BPF_LD|BPF_IMM) && a1->s->s.k == 0)
|
|
bpf_error(cstate, "division by zero");
|
|
} else if (code == BPF_MOD) {
|
|
if (a1->s->s.code == (BPF_LD|BPF_IMM) && a1->s->s.k == 0)
|
|
bpf_error(cstate, "modulus by zero");
|
|
} else if (code == BPF_LSH || code == BPF_RSH) {
|
|
/*
|
|
* XXX - we need to make up our minds as to what integers
|
|
* are signed and what integers are unsigned in BPF programs
|
|
* and in our IR.
|
|
*/
|
|
if (a1->s->s.code == (BPF_LD|BPF_IMM) &&
|
|
(a1->s->s.k < 0 || a1->s->s.k > 31))
|
|
bpf_error(cstate, "shift by more than 31 bits");
|
|
}
|
|
s0 = xfer_to_x(cstate, a1);
|
|
s1 = xfer_to_a(cstate, a0);
|
|
s2 = new_stmt(cstate, BPF_ALU|BPF_X|code);
|
|
|
|
sappend(s1, s2);
|
|
sappend(s0, s1);
|
|
sappend(a1->s, s0);
|
|
sappend(a0->s, a1->s);
|
|
|
|
free_reg(cstate, a0->regno);
|
|
free_reg(cstate, a1->regno);
|
|
|
|
s0 = new_stmt(cstate, BPF_ST);
|
|
a0->regno = s0->s.k = alloc_reg(cstate);
|
|
sappend(a0->s, s0);
|
|
|
|
return a0;
|
|
}
|
|
|
|
/*
|
|
* Initialize the table of used registers and the current register.
|
|
*/
|
|
static void
|
|
init_regs(compiler_state_t *cstate)
|
|
{
|
|
cstate->curreg = 0;
|
|
memset(cstate->regused, 0, sizeof cstate->regused);
|
|
}
|
|
|
|
/*
|
|
* Return the next free register.
|
|
*/
|
|
static int
|
|
alloc_reg(compiler_state_t *cstate)
|
|
{
|
|
int n = BPF_MEMWORDS;
|
|
|
|
while (--n >= 0) {
|
|
if (cstate->regused[cstate->curreg])
|
|
cstate->curreg = (cstate->curreg + 1) % BPF_MEMWORDS;
|
|
else {
|
|
cstate->regused[cstate->curreg] = 1;
|
|
return cstate->curreg;
|
|
}
|
|
}
|
|
bpf_error(cstate, "too many registers needed to evaluate expression");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
/*
|
|
* Return a register to the table so it can
|
|
* be used later.
|
|
*/
|
|
static void
|
|
free_reg(compiler_state_t *cstate, int n)
|
|
{
|
|
cstate->regused[n] = 0;
|
|
}
|
|
|
|
static struct block *
|
|
gen_len(compiler_state_t *cstate, int jmp, int n)
|
|
{
|
|
struct slist *s;
|
|
struct block *b;
|
|
|
|
s = new_stmt(cstate, BPF_LD|BPF_LEN);
|
|
b = new_block(cstate, JMP(jmp));
|
|
b->stmts = s;
|
|
b->s.k = n;
|
|
|
|
return b;
|
|
}
|
|
|
|
struct block *
|
|
gen_greater(compiler_state_t *cstate, int n)
|
|
{
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
return gen_len(cstate, BPF_JGE, n);
|
|
}
|
|
|
|
/*
|
|
* Actually, this is less than or equal.
|
|
*/
|
|
struct block *
|
|
gen_less(compiler_state_t *cstate, int n)
|
|
{
|
|
struct block *b;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
b = gen_len(cstate, BPF_JGT, n);
|
|
gen_not(b);
|
|
|
|
return b;
|
|
}
|
|
|
|
/*
|
|
* This is for "byte {idx} {op} {val}"; "idx" is treated as relative to
|
|
* the beginning of the link-layer header.
|
|
* XXX - that means you can't test values in the radiotap header, but
|
|
* as that header is difficult if not impossible to parse generally
|
|
* without a loop, that might not be a severe problem. A new keyword
|
|
* "radio" could be added for that, although what you'd really want
|
|
* would be a way of testing particular radio header values, which
|
|
* would generate code appropriate to the radio header in question.
|
|
*/
|
|
struct block *
|
|
gen_byteop(compiler_state_t *cstate, int op, int idx, int val)
|
|
{
|
|
struct block *b;
|
|
struct slist *s;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
switch (op) {
|
|
default:
|
|
abort();
|
|
|
|
case '=':
|
|
return gen_cmp(cstate, OR_LINKHDR, (u_int)idx, BPF_B, (bpf_int32)val);
|
|
|
|
case '<':
|
|
b = gen_cmp_lt(cstate, OR_LINKHDR, (u_int)idx, BPF_B, (bpf_int32)val);
|
|
return b;
|
|
|
|
case '>':
|
|
b = gen_cmp_gt(cstate, OR_LINKHDR, (u_int)idx, BPF_B, (bpf_int32)val);
|
|
return b;
|
|
|
|
case '|':
|
|
s = new_stmt(cstate, BPF_ALU|BPF_OR|BPF_K);
|
|
break;
|
|
|
|
case '&':
|
|
s = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_K);
|
|
break;
|
|
}
|
|
s->s.k = val;
|
|
b = new_block(cstate, JMP(BPF_JEQ));
|
|
b->stmts = s;
|
|
gen_not(b);
|
|
|
|
return b;
|
|
}
|
|
|
|
static const u_char abroadcast[] = { 0x0 };
|
|
|
|
struct block *
|
|
gen_broadcast(compiler_state_t *cstate, int proto)
|
|
{
|
|
bpf_u_int32 hostmask;
|
|
struct block *b0, *b1, *b2;
|
|
static const u_char ebroadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
switch (proto) {
|
|
|
|
case Q_DEFAULT:
|
|
case Q_LINK:
|
|
switch (cstate->linktype) {
|
|
case DLT_ARCNET:
|
|
case DLT_ARCNET_LINUX:
|
|
return gen_ahostop(cstate, abroadcast, Q_DST);
|
|
case DLT_EN10MB:
|
|
case DLT_NETANALYZER:
|
|
case DLT_NETANALYZER_TRANSPARENT:
|
|
b1 = gen_prevlinkhdr_check(cstate);
|
|
b0 = gen_ehostop(cstate, ebroadcast, Q_DST);
|
|
if (b1 != NULL)
|
|
gen_and(b1, b0);
|
|
return b0;
|
|
case DLT_FDDI:
|
|
return gen_fhostop(cstate, ebroadcast, Q_DST);
|
|
case DLT_IEEE802:
|
|
return gen_thostop(cstate, ebroadcast, Q_DST);
|
|
case DLT_IEEE802_11:
|
|
case DLT_PRISM_HEADER:
|
|
case DLT_IEEE802_11_RADIO_AVS:
|
|
case DLT_IEEE802_11_RADIO:
|
|
case DLT_PPI:
|
|
return gen_wlanhostop(cstate, ebroadcast, Q_DST);
|
|
case DLT_IP_OVER_FC:
|
|
return gen_ipfchostop(cstate, ebroadcast, Q_DST);
|
|
default:
|
|
bpf_error(cstate, "not a broadcast link");
|
|
}
|
|
/*NOTREACHED*/
|
|
|
|
case Q_IP:
|
|
/*
|
|
* We treat a netmask of PCAP_NETMASK_UNKNOWN (0xffffffff)
|
|
* as an indication that we don't know the netmask, and fail
|
|
* in that case.
|
|
*/
|
|
if (cstate->netmask == PCAP_NETMASK_UNKNOWN)
|
|
bpf_error(cstate, "netmask not known, so 'ip broadcast' not supported");
|
|
b0 = gen_linktype(cstate, ETHERTYPE_IP);
|
|
hostmask = ~cstate->netmask;
|
|
b1 = gen_mcmp(cstate, OR_LINKPL, 16, BPF_W, (bpf_int32)0, hostmask);
|
|
b2 = gen_mcmp(cstate, OR_LINKPL, 16, BPF_W,
|
|
(bpf_int32)(~0 & hostmask), hostmask);
|
|
gen_or(b1, b2);
|
|
gen_and(b0, b2);
|
|
return b2;
|
|
}
|
|
bpf_error(cstate, "only link-layer/IP broadcast filters supported");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
/*
|
|
* Generate code to test the low-order bit of a MAC address (that's
|
|
* the bottom bit of the *first* byte).
|
|
*/
|
|
static struct block *
|
|
gen_mac_multicast(compiler_state_t *cstate, int offset)
|
|
{
|
|
register struct block *b0;
|
|
register struct slist *s;
|
|
|
|
/* link[offset] & 1 != 0 */
|
|
s = gen_load_a(cstate, OR_LINKHDR, offset, BPF_B);
|
|
b0 = new_block(cstate, JMP(BPF_JSET));
|
|
b0->s.k = 1;
|
|
b0->stmts = s;
|
|
return b0;
|
|
}
|
|
|
|
struct block *
|
|
gen_multicast(compiler_state_t *cstate, int proto)
|
|
{
|
|
register struct block *b0, *b1, *b2;
|
|
register struct slist *s;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
switch (proto) {
|
|
|
|
case Q_DEFAULT:
|
|
case Q_LINK:
|
|
switch (cstate->linktype) {
|
|
case DLT_ARCNET:
|
|
case DLT_ARCNET_LINUX:
|
|
/* all ARCnet multicasts use the same address */
|
|
return gen_ahostop(cstate, abroadcast, Q_DST);
|
|
case DLT_EN10MB:
|
|
case DLT_NETANALYZER:
|
|
case DLT_NETANALYZER_TRANSPARENT:
|
|
b1 = gen_prevlinkhdr_check(cstate);
|
|
/* ether[0] & 1 != 0 */
|
|
b0 = gen_mac_multicast(cstate, 0);
|
|
if (b1 != NULL)
|
|
gen_and(b1, b0);
|
|
return b0;
|
|
case DLT_FDDI:
|
|
/*
|
|
* XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX
|
|
*
|
|
* XXX - was that referring to bit-order issues?
|
|
*/
|
|
/* fddi[1] & 1 != 0 */
|
|
return gen_mac_multicast(cstate, 1);
|
|
case DLT_IEEE802:
|
|
/* tr[2] & 1 != 0 */
|
|
return gen_mac_multicast(cstate, 2);
|
|
case DLT_IEEE802_11:
|
|
case DLT_PRISM_HEADER:
|
|
case DLT_IEEE802_11_RADIO_AVS:
|
|
case DLT_IEEE802_11_RADIO:
|
|
case DLT_PPI:
|
|
/*
|
|
* Oh, yuk.
|
|
*
|
|
* For control frames, there is no DA.
|
|
*
|
|
* For management frames, DA is at an
|
|
* offset of 4 from the beginning of
|
|
* the packet.
|
|
*
|
|
* For data frames, DA is at an offset
|
|
* of 4 from the beginning of the packet
|
|
* if To DS is clear and at an offset of
|
|
* 16 from the beginning of the packet
|
|
* if To DS is set.
|
|
*/
|
|
|
|
/*
|
|
* Generate the tests to be done for data frames.
|
|
*
|
|
* First, check for To DS set, i.e. "link[1] & 0x01".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B);
|
|
b1 = new_block(cstate, JMP(BPF_JSET));
|
|
b1->s.k = 0x01; /* To DS */
|
|
b1->stmts = s;
|
|
|
|
/*
|
|
* If To DS is set, the DA is at 16.
|
|
*/
|
|
b0 = gen_mac_multicast(cstate, 16);
|
|
gen_and(b1, b0);
|
|
|
|
/*
|
|
* Now, check for To DS not set, i.e. check
|
|
* "!(link[1] & 0x01)".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 1, BPF_B);
|
|
b2 = new_block(cstate, JMP(BPF_JSET));
|
|
b2->s.k = 0x01; /* To DS */
|
|
b2->stmts = s;
|
|
gen_not(b2);
|
|
|
|
/*
|
|
* If To DS is not set, the DA is at 4.
|
|
*/
|
|
b1 = gen_mac_multicast(cstate, 4);
|
|
gen_and(b2, b1);
|
|
|
|
/*
|
|
* Now OR together the last two checks. That gives
|
|
* the complete set of checks for data frames.
|
|
*/
|
|
gen_or(b1, b0);
|
|
|
|
/*
|
|
* Now check for a data frame.
|
|
* I.e, check "link[0] & 0x08".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
|
|
b1 = new_block(cstate, JMP(BPF_JSET));
|
|
b1->s.k = 0x08;
|
|
b1->stmts = s;
|
|
|
|
/*
|
|
* AND that with the checks done for data frames.
|
|
*/
|
|
gen_and(b1, b0);
|
|
|
|
/*
|
|
* If the high-order bit of the type value is 0, this
|
|
* is a management frame.
|
|
* I.e, check "!(link[0] & 0x08)".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
|
|
b2 = new_block(cstate, JMP(BPF_JSET));
|
|
b2->s.k = 0x08;
|
|
b2->stmts = s;
|
|
gen_not(b2);
|
|
|
|
/*
|
|
* For management frames, the DA is at 4.
|
|
*/
|
|
b1 = gen_mac_multicast(cstate, 4);
|
|
gen_and(b2, b1);
|
|
|
|
/*
|
|
* OR that with the checks done for data frames.
|
|
* That gives the checks done for management and
|
|
* data frames.
|
|
*/
|
|
gen_or(b1, b0);
|
|
|
|
/*
|
|
* If the low-order bit of the type value is 1,
|
|
* this is either a control frame or a frame
|
|
* with a reserved type, and thus not a
|
|
* frame with an SA.
|
|
*
|
|
* I.e., check "!(link[0] & 0x04)".
|
|
*/
|
|
s = gen_load_a(cstate, OR_LINKHDR, 0, BPF_B);
|
|
b1 = new_block(cstate, JMP(BPF_JSET));
|
|
b1->s.k = 0x04;
|
|
b1->stmts = s;
|
|
gen_not(b1);
|
|
|
|
/*
|
|
* AND that with the checks for data and management
|
|
* frames.
|
|
*/
|
|
gen_and(b1, b0);
|
|
return b0;
|
|
case DLT_IP_OVER_FC:
|
|
b0 = gen_mac_multicast(cstate, 2);
|
|
return b0;
|
|
default:
|
|
break;
|
|
}
|
|
/* Link not known to support multicasts */
|
|
break;
|
|
|
|
case Q_IP:
|
|
b0 = gen_linktype(cstate, ETHERTYPE_IP);
|
|
b1 = gen_cmp_ge(cstate, OR_LINKPL, 16, BPF_B, (bpf_int32)224);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case Q_IPV6:
|
|
b0 = gen_linktype(cstate, ETHERTYPE_IPV6);
|
|
b1 = gen_cmp(cstate, OR_LINKPL, 24, BPF_B, (bpf_int32)255);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
bpf_error(cstate, "link-layer multicast filters supported only on ethernet/FDDI/token ring/ARCNET/802.11/ATM LANE/Fibre Channel");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
/*
|
|
* Filter on inbound (dir == 0) or outbound (dir == 1) traffic.
|
|
* Outbound traffic is sent by this machine, while inbound traffic is
|
|
* sent by a remote machine (and may include packets destined for a
|
|
* unicast or multicast link-layer address we are not subscribing to).
|
|
* These are the same definitions implemented by pcap_setdirection().
|
|
* Capturing only unicast traffic destined for this host is probably
|
|
* better accomplished using a higher-layer filter.
|
|
*/
|
|
struct block *
|
|
gen_inbound(compiler_state_t *cstate, int dir)
|
|
{
|
|
register struct block *b0;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
/*
|
|
* Only some data link types support inbound/outbound qualifiers.
|
|
*/
|
|
switch (cstate->linktype) {
|
|
case DLT_SLIP:
|
|
b0 = gen_relation_internal(cstate, BPF_JEQ,
|
|
gen_load_internal(cstate, Q_LINK, gen_loadi_internal(cstate, 0), 1),
|
|
gen_loadi_internal(cstate, 0),
|
|
dir);
|
|
break;
|
|
|
|
case DLT_IPNET:
|
|
if (dir) {
|
|
/* match outgoing packets */
|
|
b0 = gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, IPNET_OUTBOUND);
|
|
} else {
|
|
/* match incoming packets */
|
|
b0 = gen_cmp(cstate, OR_LINKHDR, 2, BPF_H, IPNET_INBOUND);
|
|
}
|
|
break;
|
|
|
|
case DLT_LINUX_SLL:
|
|
/* match outgoing packets */
|
|
b0 = gen_cmp(cstate, OR_LINKHDR, 0, BPF_H, LINUX_SLL_OUTGOING);
|
|
if (!dir) {
|
|
/* to filter on inbound traffic, invert the match */
|
|
gen_not(b0);
|
|
}
|
|
break;
|
|
|
|
case DLT_LINUX_SLL2:
|
|
/* match outgoing packets */
|
|
b0 = gen_cmp(cstate, OR_LINKHDR, 10, BPF_B, LINUX_SLL_OUTGOING);
|
|
if (!dir) {
|
|
/* to filter on inbound traffic, invert the match */
|
|
gen_not(b0);
|
|
}
|
|
break;
|
|
|
|
#ifdef HAVE_NET_PFVAR_H
|
|
case DLT_PFLOG:
|
|
b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, dir), BPF_B,
|
|
(bpf_int32)((dir == 0) ? PF_IN : PF_OUT));
|
|
break;
|
|
#endif
|
|
|
|
case DLT_PPP_PPPD:
|
|
if (dir) {
|
|
/* match outgoing packets */
|
|
b0 = gen_cmp(cstate, OR_LINKHDR, 0, BPF_B, PPP_PPPD_OUT);
|
|
} else {
|
|
/* match incoming packets */
|
|
b0 = gen_cmp(cstate, OR_LINKHDR, 0, BPF_B, PPP_PPPD_IN);
|
|
}
|
|
break;
|
|
|
|
case DLT_JUNIPER_MFR:
|
|
case DLT_JUNIPER_MLFR:
|
|
case DLT_JUNIPER_MLPPP:
|
|
case DLT_JUNIPER_ATM1:
|
|
case DLT_JUNIPER_ATM2:
|
|
case DLT_JUNIPER_PPPOE:
|
|
case DLT_JUNIPER_PPPOE_ATM:
|
|
case DLT_JUNIPER_GGSN:
|
|
case DLT_JUNIPER_ES:
|
|
case DLT_JUNIPER_MONITOR:
|
|
case DLT_JUNIPER_SERVICES:
|
|
case DLT_JUNIPER_ETHER:
|
|
case DLT_JUNIPER_PPP:
|
|
case DLT_JUNIPER_FRELAY:
|
|
case DLT_JUNIPER_CHDLC:
|
|
case DLT_JUNIPER_VP:
|
|
case DLT_JUNIPER_ST:
|
|
case DLT_JUNIPER_ISM:
|
|
case DLT_JUNIPER_VS:
|
|
case DLT_JUNIPER_SRX_E2E:
|
|
case DLT_JUNIPER_FIBRECHANNEL:
|
|
case DLT_JUNIPER_ATM_CEMIC:
|
|
|
|
/* juniper flags (including direction) are stored
|
|
* the byte after the 3-byte magic number */
|
|
if (dir) {
|
|
/* match outgoing packets */
|
|
b0 = gen_mcmp(cstate, OR_LINKHDR, 3, BPF_B, 0, 0x01);
|
|
} else {
|
|
/* match incoming packets */
|
|
b0 = gen_mcmp(cstate, OR_LINKHDR, 3, BPF_B, 1, 0x01);
|
|
}
|
|
break;
|
|
|
|
default:
|
|
/*
|
|
* If we have packet meta-data indicating a direction,
|
|
* and that metadata can be checked by BPF code, check
|
|
* it. Otherwise, give up, as this link-layer type has
|
|
* nothing in the packet data.
|
|
*
|
|
* Currently, the only platform where a BPF filter can
|
|
* check that metadata is Linux with the in-kernel
|
|
* BPF interpreter. If other packet capture mechanisms
|
|
* and BPF filters also supported this, it would be
|
|
* nice. It would be even better if they made that
|
|
* metadata available so that we could provide it
|
|
* with newer capture APIs, allowing it to be saved
|
|
* in pcapng files.
|
|
*/
|
|
#if defined(linux) && defined(PF_PACKET) && defined(SO_ATTACH_FILTER)
|
|
/*
|
|
* This is Linux with PF_PACKET support.
|
|
* If this is a *live* capture, we can look at
|
|
* special meta-data in the filter expression;
|
|
* if it's a savefile, we can't.
|
|
*/
|
|
if (cstate->bpf_pcap->rfile != NULL) {
|
|
/* We have a FILE *, so this is a savefile */
|
|
bpf_error(cstate, "inbound/outbound not supported on %s when reading savefiles",
|
|
pcap_datalink_val_to_description_or_dlt(cstate->linktype));
|
|
b0 = NULL;
|
|
/*NOTREACHED*/
|
|
}
|
|
/* match outgoing packets */
|
|
b0 = gen_cmp(cstate, OR_LINKHDR, SKF_AD_OFF + SKF_AD_PKTTYPE, BPF_H,
|
|
PACKET_OUTGOING);
|
|
if (!dir) {
|
|
/* to filter on inbound traffic, invert the match */
|
|
gen_not(b0);
|
|
}
|
|
#else /* defined(linux) && defined(PF_PACKET) && defined(SO_ATTACH_FILTER) */
|
|
bpf_error(cstate, "inbound/outbound not supported on %s",
|
|
pcap_datalink_val_to_description_or_dlt(cstate->linktype));
|
|
/*NOTREACHED*/
|
|
#endif /* defined(linux) && defined(PF_PACKET) && defined(SO_ATTACH_FILTER) */
|
|
}
|
|
return (b0);
|
|
}
|
|
|
|
#ifdef HAVE_NET_PFVAR_H
|
|
/* PF firewall log matched interface */
|
|
struct block *
|
|
gen_pf_ifname(compiler_state_t *cstate, const char *ifname)
|
|
{
|
|
struct block *b0;
|
|
u_int len, off;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
if (cstate->linktype != DLT_PFLOG) {
|
|
bpf_error(cstate, "ifname supported only on PF linktype");
|
|
/*NOTREACHED*/
|
|
}
|
|
len = sizeof(((struct pfloghdr *)0)->ifname);
|
|
off = offsetof(struct pfloghdr, ifname);
|
|
if (strlen(ifname) >= len) {
|
|
bpf_error(cstate, "ifname interface names can only be %d characters",
|
|
len-1);
|
|
/*NOTREACHED*/
|
|
}
|
|
b0 = gen_bcmp(cstate, OR_LINKHDR, off, (u_int)strlen(ifname),
|
|
(const u_char *)ifname);
|
|
return (b0);
|
|
}
|
|
|
|
/* PF firewall log ruleset name */
|
|
struct block *
|
|
gen_pf_ruleset(compiler_state_t *cstate, char *ruleset)
|
|
{
|
|
struct block *b0;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
if (cstate->linktype != DLT_PFLOG) {
|
|
bpf_error(cstate, "ruleset supported only on PF linktype");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
if (strlen(ruleset) >= sizeof(((struct pfloghdr *)0)->ruleset)) {
|
|
bpf_error(cstate, "ruleset names can only be %ld characters",
|
|
(long)(sizeof(((struct pfloghdr *)0)->ruleset) - 1));
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
b0 = gen_bcmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, ruleset),
|
|
(u_int)strlen(ruleset), (const u_char *)ruleset);
|
|
return (b0);
|
|
}
|
|
|
|
/* PF firewall log rule number */
|
|
struct block *
|
|
gen_pf_rnr(compiler_state_t *cstate, int rnr)
|
|
{
|
|
struct block *b0;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
if (cstate->linktype != DLT_PFLOG) {
|
|
bpf_error(cstate, "rnr supported only on PF linktype");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, rulenr), BPF_W,
|
|
(bpf_int32)rnr);
|
|
return (b0);
|
|
}
|
|
|
|
/* PF firewall log sub-rule number */
|
|
struct block *
|
|
gen_pf_srnr(compiler_state_t *cstate, int srnr)
|
|
{
|
|
struct block *b0;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
if (cstate->linktype != DLT_PFLOG) {
|
|
bpf_error(cstate, "srnr supported only on PF linktype");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, subrulenr), BPF_W,
|
|
(bpf_int32)srnr);
|
|
return (b0);
|
|
}
|
|
|
|
/* PF firewall log reason code */
|
|
struct block *
|
|
gen_pf_reason(compiler_state_t *cstate, int reason)
|
|
{
|
|
struct block *b0;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
if (cstate->linktype != DLT_PFLOG) {
|
|
bpf_error(cstate, "reason supported only on PF linktype");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, reason), BPF_B,
|
|
(bpf_int32)reason);
|
|
return (b0);
|
|
}
|
|
|
|
/* PF firewall log action */
|
|
struct block *
|
|
gen_pf_action(compiler_state_t *cstate, int action)
|
|
{
|
|
struct block *b0;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
if (cstate->linktype != DLT_PFLOG) {
|
|
bpf_error(cstate, "action supported only on PF linktype");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, action), BPF_B,
|
|
(bpf_int32)action);
|
|
return (b0);
|
|
}
|
|
#else /* !HAVE_NET_PFVAR_H */
|
|
struct block *
|
|
gen_pf_ifname(compiler_state_t *cstate, const char *ifname _U_)
|
|
{
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
bpf_error(cstate, "libpcap was compiled without pf support");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
struct block *
|
|
gen_pf_ruleset(compiler_state_t *cstate, char *ruleset _U_)
|
|
{
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
bpf_error(cstate, "libpcap was compiled on a machine without pf support");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
struct block *
|
|
gen_pf_rnr(compiler_state_t *cstate, int rnr _U_)
|
|
{
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
bpf_error(cstate, "libpcap was compiled on a machine without pf support");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
struct block *
|
|
gen_pf_srnr(compiler_state_t *cstate, int srnr _U_)
|
|
{
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
bpf_error(cstate, "libpcap was compiled on a machine without pf support");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
struct block *
|
|
gen_pf_reason(compiler_state_t *cstate, int reason _U_)
|
|
{
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
bpf_error(cstate, "libpcap was compiled on a machine without pf support");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
struct block *
|
|
gen_pf_action(compiler_state_t *cstate, int action _U_)
|
|
{
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
bpf_error(cstate, "libpcap was compiled on a machine without pf support");
|
|
/*NOTREACHED*/
|
|
}
|
|
#endif /* HAVE_NET_PFVAR_H */
|
|
|
|
/* IEEE 802.11 wireless header */
|
|
struct block *
|
|
gen_p80211_type(compiler_state_t *cstate, int type, int mask)
|
|
{
|
|
struct block *b0;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
switch (cstate->linktype) {
|
|
|
|
case DLT_IEEE802_11:
|
|
case DLT_PRISM_HEADER:
|
|
case DLT_IEEE802_11_RADIO_AVS:
|
|
case DLT_IEEE802_11_RADIO:
|
|
b0 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, (bpf_int32)type,
|
|
(bpf_int32)mask);
|
|
break;
|
|
|
|
default:
|
|
bpf_error(cstate, "802.11 link-layer types supported only on 802.11");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
return (b0);
|
|
}
|
|
|
|
struct block *
|
|
gen_p80211_fcdir(compiler_state_t *cstate, int fcdir)
|
|
{
|
|
struct block *b0;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
switch (cstate->linktype) {
|
|
|
|
case DLT_IEEE802_11:
|
|
case DLT_PRISM_HEADER:
|
|
case DLT_IEEE802_11_RADIO_AVS:
|
|
case DLT_IEEE802_11_RADIO:
|
|
break;
|
|
|
|
default:
|
|
bpf_error(cstate, "frame direction supported only with 802.11 headers");
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
b0 = gen_mcmp(cstate, OR_LINKHDR, 1, BPF_B, (bpf_int32)fcdir,
|
|
(bpf_u_int32)IEEE80211_FC1_DIR_MASK);
|
|
|
|
return (b0);
|
|
}
|
|
|
|
struct block *
|
|
gen_acode(compiler_state_t *cstate, const char *s, struct qual q)
|
|
{
|
|
struct block *b;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
switch (cstate->linktype) {
|
|
|
|
case DLT_ARCNET:
|
|
case DLT_ARCNET_LINUX:
|
|
if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) &&
|
|
q.proto == Q_LINK) {
|
|
cstate->e = pcap_ether_aton(s);
|
|
if (cstate->e == NULL)
|
|
bpf_error(cstate, "malloc");
|
|
b = gen_ahostop(cstate, cstate->e, (int)q.dir);
|
|
free(cstate->e);
|
|
cstate->e = NULL;
|
|
return (b);
|
|
} else
|
|
bpf_error(cstate, "ARCnet address used in non-arc expression");
|
|
/*NOTREACHED*/
|
|
|
|
default:
|
|
bpf_error(cstate, "aid supported only on ARCnet");
|
|
/*NOTREACHED*/
|
|
}
|
|
}
|
|
|
|
static struct block *
|
|
gen_ahostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
|
|
{
|
|
register struct block *b0, *b1;
|
|
|
|
switch (dir) {
|
|
/* src comes first, different from Ethernet */
|
|
case Q_SRC:
|
|
return gen_bcmp(cstate, OR_LINKHDR, 0, 1, eaddr);
|
|
|
|
case Q_DST:
|
|
return gen_bcmp(cstate, OR_LINKHDR, 1, 1, eaddr);
|
|
|
|
case Q_AND:
|
|
b0 = gen_ahostop(cstate, eaddr, Q_SRC);
|
|
b1 = gen_ahostop(cstate, eaddr, Q_DST);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
|
|
case Q_DEFAULT:
|
|
case Q_OR:
|
|
b0 = gen_ahostop(cstate, eaddr, Q_SRC);
|
|
b1 = gen_ahostop(cstate, eaddr, Q_DST);
|
|
gen_or(b0, b1);
|
|
return b1;
|
|
|
|
case Q_ADDR1:
|
|
bpf_error(cstate, "'addr1' and 'address1' are only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR2:
|
|
bpf_error(cstate, "'addr2' and 'address2' are only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR3:
|
|
bpf_error(cstate, "'addr3' and 'address3' are only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_ADDR4:
|
|
bpf_error(cstate, "'addr4' and 'address4' are only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_RA:
|
|
bpf_error(cstate, "'ra' is only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
|
|
case Q_TA:
|
|
bpf_error(cstate, "'ta' is only supported on 802.11");
|
|
/*NOTREACHED*/
|
|
}
|
|
abort();
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
static struct block *
|
|
gen_vlan_tpid_test(compiler_state_t *cstate)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
/* check for VLAN, including QinQ */
|
|
b0 = gen_linktype(cstate, ETHERTYPE_8021Q);
|
|
b1 = gen_linktype(cstate, ETHERTYPE_8021AD);
|
|
gen_or(b0,b1);
|
|
b0 = b1;
|
|
b1 = gen_linktype(cstate, ETHERTYPE_8021QINQ);
|
|
gen_or(b0,b1);
|
|
|
|
return b1;
|
|
}
|
|
|
|
static struct block *
|
|
gen_vlan_vid_test(compiler_state_t *cstate, bpf_u_int32 vlan_num)
|
|
{
|
|
if (vlan_num > 0x0fff) {
|
|
bpf_error(cstate, "VLAN tag %u greater than maximum %u",
|
|
vlan_num, 0x0fff);
|
|
}
|
|
return gen_mcmp(cstate, OR_LINKPL, 0, BPF_H, (bpf_int32)vlan_num, 0x0fff);
|
|
}
|
|
|
|
static struct block *
|
|
gen_vlan_no_bpf_extensions(compiler_state_t *cstate, bpf_u_int32 vlan_num,
|
|
int has_vlan_tag)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
b0 = gen_vlan_tpid_test(cstate);
|
|
|
|
if (has_vlan_tag) {
|
|
b1 = gen_vlan_vid_test(cstate, vlan_num);
|
|
gen_and(b0, b1);
|
|
b0 = b1;
|
|
}
|
|
|
|
/*
|
|
* Both payload and link header type follow the VLAN tags so that
|
|
* both need to be updated.
|
|
*/
|
|
cstate->off_linkpl.constant_part += 4;
|
|
cstate->off_linktype.constant_part += 4;
|
|
|
|
return b0;
|
|
}
|
|
|
|
#if defined(SKF_AD_VLAN_TAG_PRESENT)
|
|
/* add v to variable part of off */
|
|
static void
|
|
gen_vlan_vloffset_add(compiler_state_t *cstate, bpf_abs_offset *off, int v, struct slist *s)
|
|
{
|
|
struct slist *s2;
|
|
|
|
if (!off->is_variable)
|
|
off->is_variable = 1;
|
|
if (off->reg == -1)
|
|
off->reg = alloc_reg(cstate);
|
|
|
|
s2 = new_stmt(cstate, BPF_LD|BPF_MEM);
|
|
s2->s.k = off->reg;
|
|
sappend(s, s2);
|
|
s2 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_IMM);
|
|
s2->s.k = v;
|
|
sappend(s, s2);
|
|
s2 = new_stmt(cstate, BPF_ST);
|
|
s2->s.k = off->reg;
|
|
sappend(s, s2);
|
|
}
|
|
|
|
/*
|
|
* patch block b_tpid (VLAN TPID test) to update variable parts of link payload
|
|
* and link type offsets first
|
|
*/
|
|
static void
|
|
gen_vlan_patch_tpid_test(compiler_state_t *cstate, struct block *b_tpid)
|
|
{
|
|
struct slist s;
|
|
|
|
/* offset determined at run time, shift variable part */
|
|
s.next = NULL;
|
|
cstate->is_vlan_vloffset = 1;
|
|
gen_vlan_vloffset_add(cstate, &cstate->off_linkpl, 4, &s);
|
|
gen_vlan_vloffset_add(cstate, &cstate->off_linktype, 4, &s);
|
|
|
|
/* we get a pointer to a chain of or-ed blocks, patch first of them */
|
|
sappend(s.next, b_tpid->head->stmts);
|
|
b_tpid->head->stmts = s.next;
|
|
}
|
|
|
|
/*
|
|
* patch block b_vid (VLAN id test) to load VID value either from packet
|
|
* metadata (using BPF extensions) if SKF_AD_VLAN_TAG_PRESENT is true
|
|
*/
|
|
static void
|
|
gen_vlan_patch_vid_test(compiler_state_t *cstate, struct block *b_vid)
|
|
{
|
|
struct slist *s, *s2, *sjeq;
|
|
unsigned cnt;
|
|
|
|
s = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS);
|
|
s->s.k = SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT;
|
|
|
|
/* true -> next instructions, false -> beginning of b_vid */
|
|
sjeq = new_stmt(cstate, JMP(BPF_JEQ));
|
|
sjeq->s.k = 1;
|
|
sjeq->s.jf = b_vid->stmts;
|
|
sappend(s, sjeq);
|
|
|
|
s2 = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS);
|
|
s2->s.k = SKF_AD_OFF + SKF_AD_VLAN_TAG;
|
|
sappend(s, s2);
|
|
sjeq->s.jt = s2;
|
|
|
|
/* Jump to the test in b_vid. We need to jump one instruction before
|
|
* the end of the b_vid block so that we only skip loading the TCI
|
|
* from packet data and not the 'and' instruction extractging VID.
|
|
*/
|
|
cnt = 0;
|
|
for (s2 = b_vid->stmts; s2; s2 = s2->next)
|
|
cnt++;
|
|
s2 = new_stmt(cstate, JMP(BPF_JA));
|
|
s2->s.k = cnt - 1;
|
|
sappend(s, s2);
|
|
|
|
/* insert our statements at the beginning of b_vid */
|
|
sappend(s, b_vid->stmts);
|
|
b_vid->stmts = s;
|
|
}
|
|
|
|
/*
|
|
* Generate check for "vlan" or "vlan <id>" on systems with support for BPF
|
|
* extensions. Even if kernel supports VLAN BPF extensions, (outermost) VLAN
|
|
* tag can be either in metadata or in packet data; therefore if the
|
|
* SKF_AD_VLAN_TAG_PRESENT test is negative, we need to check link
|
|
* header for VLAN tag. As the decision is done at run time, we need
|
|
* update variable part of the offsets
|
|
*/
|
|
static struct block *
|
|
gen_vlan_bpf_extensions(compiler_state_t *cstate, bpf_u_int32 vlan_num,
|
|
int has_vlan_tag)
|
|
{
|
|
struct block *b0, *b_tpid, *b_vid = NULL;
|
|
struct slist *s;
|
|
|
|
/* generate new filter code based on extracting packet
|
|
* metadata */
|
|
s = new_stmt(cstate, BPF_LD|BPF_B|BPF_ABS);
|
|
s->s.k = SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT;
|
|
|
|
b0 = new_block(cstate, JMP(BPF_JEQ));
|
|
b0->stmts = s;
|
|
b0->s.k = 1;
|
|
|
|
/*
|
|
* This is tricky. We need to insert the statements updating variable
|
|
* parts of offsets before the the traditional TPID and VID tests so
|
|
* that they are called whenever SKF_AD_VLAN_TAG_PRESENT fails but
|
|
* we do not want this update to affect those checks. That's why we
|
|
* generate both test blocks first and insert the statements updating
|
|
* variable parts of both offsets after that. This wouldn't work if
|
|
* there already were variable length link header when entering this
|
|
* function but gen_vlan_bpf_extensions() isn't called in that case.
|
|
*/
|
|
b_tpid = gen_vlan_tpid_test(cstate);
|
|
if (has_vlan_tag)
|
|
b_vid = gen_vlan_vid_test(cstate, vlan_num);
|
|
|
|
gen_vlan_patch_tpid_test(cstate, b_tpid);
|
|
gen_or(b0, b_tpid);
|
|
b0 = b_tpid;
|
|
|
|
if (has_vlan_tag) {
|
|
gen_vlan_patch_vid_test(cstate, b_vid);
|
|
gen_and(b0, b_vid);
|
|
b0 = b_vid;
|
|
}
|
|
|
|
return b0;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* support IEEE 802.1Q VLAN trunk over ethernet
|
|
*/
|
|
struct block *
|
|
gen_vlan(compiler_state_t *cstate, bpf_u_int32 vlan_num, int has_vlan_tag)
|
|
{
|
|
struct block *b0;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
/* can't check for VLAN-encapsulated packets inside MPLS */
|
|
if (cstate->label_stack_depth > 0)
|
|
bpf_error(cstate, "no VLAN match after MPLS");
|
|
|
|
/*
|
|
* Check for a VLAN packet, and then change the offsets to point
|
|
* to the type and data fields within the VLAN packet. Just
|
|
* increment the offsets, so that we can support a hierarchy, e.g.
|
|
* "vlan 300 && vlan 200" to capture VLAN 200 encapsulated within
|
|
* VLAN 100.
|
|
*
|
|
* XXX - this is a bit of a kludge. If we were to split the
|
|
* compiler into a parser that parses an expression and
|
|
* generates an expression tree, and a code generator that
|
|
* takes an expression tree (which could come from our
|
|
* parser or from some other parser) and generates BPF code,
|
|
* we could perhaps make the offsets parameters of routines
|
|
* and, in the handler for an "AND" node, pass to subnodes
|
|
* other than the VLAN node the adjusted offsets.
|
|
*
|
|
* This would mean that "vlan" would, instead of changing the
|
|
* behavior of *all* tests after it, change only the behavior
|
|
* of tests ANDed with it. That would change the documented
|
|
* semantics of "vlan", which might break some expressions.
|
|
* However, it would mean that "(vlan and ip) or ip" would check
|
|
* both for VLAN-encapsulated IP and IP-over-Ethernet, rather than
|
|
* checking only for VLAN-encapsulated IP, so that could still
|
|
* be considered worth doing; it wouldn't break expressions
|
|
* that are of the form "vlan and ..." or "vlan N and ...",
|
|
* which I suspect are the most common expressions involving
|
|
* "vlan". "vlan or ..." doesn't necessarily do what the user
|
|
* would really want, now, as all the "or ..." tests would
|
|
* be done assuming a VLAN, even though the "or" could be viewed
|
|
* as meaning "or, if this isn't a VLAN packet...".
|
|
*/
|
|
switch (cstate->linktype) {
|
|
|
|
case DLT_EN10MB:
|
|
case DLT_NETANALYZER:
|
|
case DLT_NETANALYZER_TRANSPARENT:
|
|
#if defined(SKF_AD_VLAN_TAG_PRESENT)
|
|
/* Verify that this is the outer part of the packet and
|
|
* not encapsulated somehow. */
|
|
if (cstate->vlan_stack_depth == 0 && !cstate->off_linkhdr.is_variable &&
|
|
cstate->off_linkhdr.constant_part ==
|
|
cstate->off_outermostlinkhdr.constant_part) {
|
|
/*
|
|
* Do we need special VLAN handling?
|
|
*/
|
|
if (cstate->bpf_pcap->bpf_codegen_flags & BPF_SPECIAL_VLAN_HANDLING)
|
|
b0 = gen_vlan_bpf_extensions(cstate, vlan_num,
|
|
has_vlan_tag);
|
|
else
|
|
b0 = gen_vlan_no_bpf_extensions(cstate,
|
|
vlan_num, has_vlan_tag);
|
|
} else
|
|
#endif
|
|
b0 = gen_vlan_no_bpf_extensions(cstate, vlan_num,
|
|
has_vlan_tag);
|
|
break;
|
|
|
|
case DLT_IEEE802_11:
|
|
case DLT_PRISM_HEADER:
|
|
case DLT_IEEE802_11_RADIO_AVS:
|
|
case DLT_IEEE802_11_RADIO:
|
|
b0 = gen_vlan_no_bpf_extensions(cstate, vlan_num, has_vlan_tag);
|
|
break;
|
|
|
|
default:
|
|
bpf_error(cstate, "no VLAN support for %s",
|
|
pcap_datalink_val_to_description_or_dlt(cstate->linktype));
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
cstate->vlan_stack_depth++;
|
|
|
|
return (b0);
|
|
}
|
|
|
|
/*
|
|
* support for MPLS
|
|
*
|
|
* The label_num_arg dance is to avoid annoying whining by compilers that
|
|
* label_num might be clobbered by longjmp - yeah, it might, but *WHO CARES*?
|
|
* It's not *used* after setjmp returns.
|
|
*/
|
|
struct block *
|
|
gen_mpls(compiler_state_t *cstate, bpf_u_int32 label_num_arg,
|
|
int has_label_num)
|
|
{
|
|
volatile bpf_u_int32 label_num = label_num_arg;
|
|
struct block *b0, *b1;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
if (cstate->label_stack_depth > 0) {
|
|
/* just match the bottom-of-stack bit clear */
|
|
b0 = gen_mcmp(cstate, OR_PREVMPLSHDR, 2, BPF_B, 0, 0x01);
|
|
} else {
|
|
/*
|
|
* We're not in an MPLS stack yet, so check the link-layer
|
|
* type against MPLS.
|
|
*/
|
|
switch (cstate->linktype) {
|
|
|
|
case DLT_C_HDLC: /* fall through */
|
|
case DLT_EN10MB:
|
|
case DLT_NETANALYZER:
|
|
case DLT_NETANALYZER_TRANSPARENT:
|
|
b0 = gen_linktype(cstate, ETHERTYPE_MPLS);
|
|
break;
|
|
|
|
case DLT_PPP:
|
|
b0 = gen_linktype(cstate, PPP_MPLS_UCAST);
|
|
break;
|
|
|
|
/* FIXME add other DLT_s ...
|
|
* for Frame-Relay/and ATM this may get messy due to SNAP headers
|
|
* leave it for now */
|
|
|
|
default:
|
|
bpf_error(cstate, "no MPLS support for %s",
|
|
pcap_datalink_val_to_description_or_dlt(cstate->linktype));
|
|
/*NOTREACHED*/
|
|
}
|
|
}
|
|
|
|
/* If a specific MPLS label is requested, check it */
|
|
if (has_label_num) {
|
|
if (label_num > 0xFFFFF) {
|
|
bpf_error(cstate, "MPLS label %u greater than maximum %u",
|
|
label_num, 0xFFFFF);
|
|
}
|
|
label_num = label_num << 12; /* label is shifted 12 bits on the wire */
|
|
b1 = gen_mcmp(cstate, OR_LINKPL, 0, BPF_W, (bpf_int32)label_num,
|
|
0xfffff000); /* only compare the first 20 bits */
|
|
gen_and(b0, b1);
|
|
b0 = b1;
|
|
}
|
|
|
|
/*
|
|
* Change the offsets to point to the type and data fields within
|
|
* the MPLS packet. Just increment the offsets, so that we
|
|
* can support a hierarchy, e.g. "mpls 100000 && mpls 1024" to
|
|
* capture packets with an outer label of 100000 and an inner
|
|
* label of 1024.
|
|
*
|
|
* Increment the MPLS stack depth as well; this indicates that
|
|
* we're checking MPLS-encapsulated headers, to make sure higher
|
|
* level code generators don't try to match against IP-related
|
|
* protocols such as Q_ARP, Q_RARP etc.
|
|
*
|
|
* XXX - this is a bit of a kludge. See comments in gen_vlan().
|
|
*/
|
|
cstate->off_nl_nosnap += 4;
|
|
cstate->off_nl += 4;
|
|
cstate->label_stack_depth++;
|
|
return (b0);
|
|
}
|
|
|
|
/*
|
|
* Support PPPOE discovery and session.
|
|
*/
|
|
struct block *
|
|
gen_pppoed(compiler_state_t *cstate)
|
|
{
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
/* check for PPPoE discovery */
|
|
return gen_linktype(cstate, (bpf_int32)ETHERTYPE_PPPOED);
|
|
}
|
|
|
|
struct block *
|
|
gen_pppoes(compiler_state_t *cstate, bpf_u_int32 sess_num, int has_sess_num)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
/*
|
|
* Test against the PPPoE session link-layer type.
|
|
*/
|
|
b0 = gen_linktype(cstate, (bpf_int32)ETHERTYPE_PPPOES);
|
|
|
|
/* If a specific session is requested, check PPPoE session id */
|
|
if (has_sess_num) {
|
|
if (sess_num > 0x0000ffff) {
|
|
bpf_error(cstate, "PPPoE session number %u greater than maximum %u",
|
|
sess_num, 0x0000ffff);
|
|
}
|
|
b1 = gen_mcmp(cstate, OR_LINKPL, 0, BPF_W,
|
|
(bpf_int32)sess_num, 0x0000ffff);
|
|
gen_and(b0, b1);
|
|
b0 = b1;
|
|
}
|
|
|
|
/*
|
|
* Change the offsets to point to the type and data fields within
|
|
* the PPP packet, and note that this is PPPoE rather than
|
|
* raw PPP.
|
|
*
|
|
* XXX - this is a bit of a kludge. See the comments in
|
|
* gen_vlan().
|
|
*
|
|
* The "network-layer" protocol is PPPoE, which has a 6-byte
|
|
* PPPoE header, followed by a PPP packet.
|
|
*
|
|
* There is no HDLC encapsulation for the PPP packet (it's
|
|
* encapsulated in PPPoES instead), so the link-layer type
|
|
* starts at the first byte of the PPP packet. For PPPoE,
|
|
* that offset is relative to the beginning of the total
|
|
* link-layer payload, including any 802.2 LLC header, so
|
|
* it's 6 bytes past cstate->off_nl.
|
|
*/
|
|
PUSH_LINKHDR(cstate, DLT_PPP, cstate->off_linkpl.is_variable,
|
|
cstate->off_linkpl.constant_part + cstate->off_nl + 6, /* 6 bytes past the PPPoE header */
|
|
cstate->off_linkpl.reg);
|
|
|
|
cstate->off_linktype = cstate->off_linkhdr;
|
|
cstate->off_linkpl.constant_part = cstate->off_linkhdr.constant_part + 2;
|
|
|
|
cstate->off_nl = 0;
|
|
cstate->off_nl_nosnap = 0; /* no 802.2 LLC */
|
|
|
|
return b0;
|
|
}
|
|
|
|
/* Check that this is Geneve and the VNI is correct if
|
|
* specified. Parameterized to handle both IPv4 and IPv6. */
|
|
static struct block *
|
|
gen_geneve_check(compiler_state_t *cstate,
|
|
struct block *(*gen_portfn)(compiler_state_t *, int, int, int),
|
|
enum e_offrel offrel, bpf_u_int32 vni, int has_vni)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
b0 = gen_portfn(cstate, GENEVE_PORT, IPPROTO_UDP, Q_DST);
|
|
|
|
/* Check that we are operating on version 0. Otherwise, we
|
|
* can't decode the rest of the fields. The version is 2 bits
|
|
* in the first byte of the Geneve header. */
|
|
b1 = gen_mcmp(cstate, offrel, 8, BPF_B, (bpf_int32)0, 0xc0);
|
|
gen_and(b0, b1);
|
|
b0 = b1;
|
|
|
|
if (has_vni) {
|
|
if (vni > 0xffffff) {
|
|
bpf_error(cstate, "Geneve VNI %u greater than maximum %u",
|
|
vni, 0xffffff);
|
|
}
|
|
vni <<= 8; /* VNI is in the upper 3 bytes */
|
|
b1 = gen_mcmp(cstate, offrel, 12, BPF_W, (bpf_int32)vni,
|
|
0xffffff00);
|
|
gen_and(b0, b1);
|
|
b0 = b1;
|
|
}
|
|
|
|
return b0;
|
|
}
|
|
|
|
/* The IPv4 and IPv6 Geneve checks need to do two things:
|
|
* - Verify that this actually is Geneve with the right VNI.
|
|
* - Place the IP header length (plus variable link prefix if
|
|
* needed) into register A to be used later to compute
|
|
* the inner packet offsets. */
|
|
static struct block *
|
|
gen_geneve4(compiler_state_t *cstate, bpf_u_int32 vni, int has_vni)
|
|
{
|
|
struct block *b0, *b1;
|
|
struct slist *s, *s1;
|
|
|
|
b0 = gen_geneve_check(cstate, gen_port, OR_TRAN_IPV4, vni, has_vni);
|
|
|
|
/* Load the IP header length into A. */
|
|
s = gen_loadx_iphdrlen(cstate);
|
|
|
|
s1 = new_stmt(cstate, BPF_MISC|BPF_TXA);
|
|
sappend(s, s1);
|
|
|
|
/* Forcibly append these statements to the true condition
|
|
* of the protocol check by creating a new block that is
|
|
* always true and ANDing them. */
|
|
b1 = new_block(cstate, BPF_JMP|BPF_JEQ|BPF_X);
|
|
b1->stmts = s;
|
|
b1->s.k = 0;
|
|
|
|
gen_and(b0, b1);
|
|
|
|
return b1;
|
|
}
|
|
|
|
static struct block *
|
|
gen_geneve6(compiler_state_t *cstate, bpf_u_int32 vni, int has_vni)
|
|
{
|
|
struct block *b0, *b1;
|
|
struct slist *s, *s1;
|
|
|
|
b0 = gen_geneve_check(cstate, gen_port6, OR_TRAN_IPV6, vni, has_vni);
|
|
|
|
/* Load the IP header length. We need to account for a
|
|
* variable length link prefix if there is one. */
|
|
s = gen_abs_offset_varpart(cstate, &cstate->off_linkpl);
|
|
if (s) {
|
|
s1 = new_stmt(cstate, BPF_LD|BPF_IMM);
|
|
s1->s.k = 40;
|
|
sappend(s, s1);
|
|
|
|
s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X);
|
|
s1->s.k = 0;
|
|
sappend(s, s1);
|
|
} else {
|
|
s = new_stmt(cstate, BPF_LD|BPF_IMM);
|
|
s->s.k = 40;
|
|
}
|
|
|
|
/* Forcibly append these statements to the true condition
|
|
* of the protocol check by creating a new block that is
|
|
* always true and ANDing them. */
|
|
s1 = new_stmt(cstate, BPF_MISC|BPF_TAX);
|
|
sappend(s, s1);
|
|
|
|
b1 = new_block(cstate, BPF_JMP|BPF_JEQ|BPF_X);
|
|
b1->stmts = s;
|
|
b1->s.k = 0;
|
|
|
|
gen_and(b0, b1);
|
|
|
|
return b1;
|
|
}
|
|
|
|
/* We need to store three values based on the Geneve header::
|
|
* - The offset of the linktype.
|
|
* - The offset of the end of the Geneve header.
|
|
* - The offset of the end of the encapsulated MAC header. */
|
|
static struct slist *
|
|
gen_geneve_offsets(compiler_state_t *cstate)
|
|
{
|
|
struct slist *s, *s1, *s_proto;
|
|
|
|
/* First we need to calculate the offset of the Geneve header
|
|
* itself. This is composed of the IP header previously calculated
|
|
* (include any variable link prefix) and stored in A plus the
|
|
* fixed sized headers (fixed link prefix, MAC length, and UDP
|
|
* header). */
|
|
s = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
|
|
s->s.k = cstate->off_linkpl.constant_part + cstate->off_nl + 8;
|
|
|
|
/* Stash this in X since we'll need it later. */
|
|
s1 = new_stmt(cstate, BPF_MISC|BPF_TAX);
|
|
sappend(s, s1);
|
|
|
|
/* The EtherType in Geneve is 2 bytes in. Calculate this and
|
|
* store it. */
|
|
s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
|
|
s1->s.k = 2;
|
|
sappend(s, s1);
|
|
|
|
cstate->off_linktype.reg = alloc_reg(cstate);
|
|
cstate->off_linktype.is_variable = 1;
|
|
cstate->off_linktype.constant_part = 0;
|
|
|
|
s1 = new_stmt(cstate, BPF_ST);
|
|
s1->s.k = cstate->off_linktype.reg;
|
|
sappend(s, s1);
|
|
|
|
/* Load the Geneve option length and mask and shift to get the
|
|
* number of bytes. It is stored in the first byte of the Geneve
|
|
* header. */
|
|
s1 = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B);
|
|
s1->s.k = 0;
|
|
sappend(s, s1);
|
|
|
|
s1 = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_K);
|
|
s1->s.k = 0x3f;
|
|
sappend(s, s1);
|
|
|
|
s1 = new_stmt(cstate, BPF_ALU|BPF_MUL|BPF_K);
|
|
s1->s.k = 4;
|
|
sappend(s, s1);
|
|
|
|
/* Add in the rest of the Geneve base header. */
|
|
s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
|
|
s1->s.k = 8;
|
|
sappend(s, s1);
|
|
|
|
/* Add the Geneve header length to its offset and store. */
|
|
s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_X);
|
|
s1->s.k = 0;
|
|
sappend(s, s1);
|
|
|
|
/* Set the encapsulated type as Ethernet. Even though we may
|
|
* not actually have Ethernet inside there are two reasons this
|
|
* is useful:
|
|
* - The linktype field is always in EtherType format regardless
|
|
* of whether it is in Geneve or an inner Ethernet frame.
|
|
* - The only link layer that we have specific support for is
|
|
* Ethernet. We will confirm that the packet actually is
|
|
* Ethernet at runtime before executing these checks. */
|
|
PUSH_LINKHDR(cstate, DLT_EN10MB, 1, 0, alloc_reg(cstate));
|
|
|
|
s1 = new_stmt(cstate, BPF_ST);
|
|
s1->s.k = cstate->off_linkhdr.reg;
|
|
sappend(s, s1);
|
|
|
|
/* Calculate whether we have an Ethernet header or just raw IP/
|
|
* MPLS/etc. If we have Ethernet, advance the end of the MAC offset
|
|
* and linktype by 14 bytes so that the network header can be found
|
|
* seamlessly. Otherwise, keep what we've calculated already. */
|
|
|
|
/* We have a bare jmp so we can't use the optimizer. */
|
|
cstate->no_optimize = 1;
|
|
|
|
/* Load the EtherType in the Geneve header, 2 bytes in. */
|
|
s1 = new_stmt(cstate, BPF_LD|BPF_IND|BPF_H);
|
|
s1->s.k = 2;
|
|
sappend(s, s1);
|
|
|
|
/* Load X with the end of the Geneve header. */
|
|
s1 = new_stmt(cstate, BPF_LDX|BPF_MEM);
|
|
s1->s.k = cstate->off_linkhdr.reg;
|
|
sappend(s, s1);
|
|
|
|
/* Check if the EtherType is Transparent Ethernet Bridging. At the
|
|
* end of this check, we should have the total length in X. In
|
|
* the non-Ethernet case, it's already there. */
|
|
s_proto = new_stmt(cstate, JMP(BPF_JEQ));
|
|
s_proto->s.k = ETHERTYPE_TEB;
|
|
sappend(s, s_proto);
|
|
|
|
s1 = new_stmt(cstate, BPF_MISC|BPF_TXA);
|
|
sappend(s, s1);
|
|
s_proto->s.jt = s1;
|
|
|
|
/* Since this is Ethernet, use the EtherType of the payload
|
|
* directly as the linktype. Overwrite what we already have. */
|
|
s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
|
|
s1->s.k = 12;
|
|
sappend(s, s1);
|
|
|
|
s1 = new_stmt(cstate, BPF_ST);
|
|
s1->s.k = cstate->off_linktype.reg;
|
|
sappend(s, s1);
|
|
|
|
/* Advance two bytes further to get the end of the Ethernet
|
|
* header. */
|
|
s1 = new_stmt(cstate, BPF_ALU|BPF_ADD|BPF_K);
|
|
s1->s.k = 2;
|
|
sappend(s, s1);
|
|
|
|
/* Move the result to X. */
|
|
s1 = new_stmt(cstate, BPF_MISC|BPF_TAX);
|
|
sappend(s, s1);
|
|
|
|
/* Store the final result of our linkpl calculation. */
|
|
cstate->off_linkpl.reg = alloc_reg(cstate);
|
|
cstate->off_linkpl.is_variable = 1;
|
|
cstate->off_linkpl.constant_part = 0;
|
|
|
|
s1 = new_stmt(cstate, BPF_STX);
|
|
s1->s.k = cstate->off_linkpl.reg;
|
|
sappend(s, s1);
|
|
s_proto->s.jf = s1;
|
|
|
|
cstate->off_nl = 0;
|
|
|
|
return s;
|
|
}
|
|
|
|
/* Check to see if this is a Geneve packet. */
|
|
struct block *
|
|
gen_geneve(compiler_state_t *cstate, bpf_u_int32 vni, int has_vni)
|
|
{
|
|
struct block *b0, *b1;
|
|
struct slist *s;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
b0 = gen_geneve4(cstate, vni, has_vni);
|
|
b1 = gen_geneve6(cstate, vni, has_vni);
|
|
|
|
gen_or(b0, b1);
|
|
b0 = b1;
|
|
|
|
/* Later filters should act on the payload of the Geneve frame,
|
|
* update all of the header pointers. Attach this code so that
|
|
* it gets executed in the event that the Geneve filter matches. */
|
|
s = gen_geneve_offsets(cstate);
|
|
|
|
b1 = gen_true(cstate);
|
|
sappend(s, b1->stmts);
|
|
b1->stmts = s;
|
|
|
|
gen_and(b0, b1);
|
|
|
|
cstate->is_geneve = 1;
|
|
|
|
return b1;
|
|
}
|
|
|
|
/* Check that the encapsulated frame has a link layer header
|
|
* for Ethernet filters. */
|
|
static struct block *
|
|
gen_geneve_ll_check(compiler_state_t *cstate)
|
|
{
|
|
struct block *b0;
|
|
struct slist *s, *s1;
|
|
|
|
/* The easiest way to see if there is a link layer present
|
|
* is to check if the link layer header and payload are not
|
|
* the same. */
|
|
|
|
/* Geneve always generates pure variable offsets so we can
|
|
* compare only the registers. */
|
|
s = new_stmt(cstate, BPF_LD|BPF_MEM);
|
|
s->s.k = cstate->off_linkhdr.reg;
|
|
|
|
s1 = new_stmt(cstate, BPF_LDX|BPF_MEM);
|
|
s1->s.k = cstate->off_linkpl.reg;
|
|
sappend(s, s1);
|
|
|
|
b0 = new_block(cstate, BPF_JMP|BPF_JEQ|BPF_X);
|
|
b0->stmts = s;
|
|
b0->s.k = 0;
|
|
gen_not(b0);
|
|
|
|
return b0;
|
|
}
|
|
|
|
static struct block *
|
|
gen_atmfield_code_internal(compiler_state_t *cstate, int atmfield,
|
|
bpf_int32 jvalue, bpf_u_int32 jtype, int reverse)
|
|
{
|
|
struct block *b0;
|
|
|
|
switch (atmfield) {
|
|
|
|
case A_VPI:
|
|
if (!cstate->is_atm)
|
|
bpf_error(cstate, "'vpi' supported only on raw ATM");
|
|
if (cstate->off_vpi == OFFSET_NOT_SET)
|
|
abort();
|
|
b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_vpi, BPF_B, 0xffffffff, jtype,
|
|
reverse, jvalue);
|
|
break;
|
|
|
|
case A_VCI:
|
|
if (!cstate->is_atm)
|
|
bpf_error(cstate, "'vci' supported only on raw ATM");
|
|
if (cstate->off_vci == OFFSET_NOT_SET)
|
|
abort();
|
|
b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_vci, BPF_H, 0xffffffff, jtype,
|
|
reverse, jvalue);
|
|
break;
|
|
|
|
case A_PROTOTYPE:
|
|
if (cstate->off_proto == OFFSET_NOT_SET)
|
|
abort(); /* XXX - this isn't on FreeBSD */
|
|
b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_proto, BPF_B, 0x0f, jtype,
|
|
reverse, jvalue);
|
|
break;
|
|
|
|
case A_MSGTYPE:
|
|
if (cstate->off_payload == OFFSET_NOT_SET)
|
|
abort();
|
|
b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_payload + MSG_TYPE_POS, BPF_B,
|
|
0xffffffff, jtype, reverse, jvalue);
|
|
break;
|
|
|
|
case A_CALLREFTYPE:
|
|
if (!cstate->is_atm)
|
|
bpf_error(cstate, "'callref' supported only on raw ATM");
|
|
if (cstate->off_proto == OFFSET_NOT_SET)
|
|
abort();
|
|
b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_proto, BPF_B, 0xffffffff,
|
|
jtype, reverse, jvalue);
|
|
break;
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
return b0;
|
|
}
|
|
|
|
static struct block *
|
|
gen_atmtype_metac(compiler_state_t *cstate)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0);
|
|
b1 = gen_atmfield_code_internal(cstate, A_VCI, 1, BPF_JEQ, 0);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
|
|
static struct block *
|
|
gen_atmtype_sc(compiler_state_t *cstate)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0);
|
|
b1 = gen_atmfield_code_internal(cstate, A_VCI, 5, BPF_JEQ, 0);
|
|
gen_and(b0, b1);
|
|
return b1;
|
|
}
|
|
|
|
static struct block *
|
|
gen_atmtype_llc(compiler_state_t *cstate)
|
|
{
|
|
struct block *b0;
|
|
|
|
b0 = gen_atmfield_code_internal(cstate, A_PROTOTYPE, PT_LLC, BPF_JEQ, 0);
|
|
cstate->linktype = cstate->prevlinktype;
|
|
return b0;
|
|
}
|
|
|
|
struct block *
|
|
gen_atmfield_code(compiler_state_t *cstate, int atmfield,
|
|
bpf_int32 jvalue, bpf_u_int32 jtype, int reverse)
|
|
{
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
return gen_atmfield_code_internal(cstate, atmfield, jvalue, jtype,
|
|
reverse);
|
|
}
|
|
|
|
struct block *
|
|
gen_atmtype_abbrev(compiler_state_t *cstate, int type)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
switch (type) {
|
|
|
|
case A_METAC:
|
|
/* Get all packets in Meta signalling Circuit */
|
|
if (!cstate->is_atm)
|
|
bpf_error(cstate, "'metac' supported only on raw ATM");
|
|
b1 = gen_atmtype_metac(cstate);
|
|
break;
|
|
|
|
case A_BCC:
|
|
/* Get all packets in Broadcast Circuit*/
|
|
if (!cstate->is_atm)
|
|
bpf_error(cstate, "'bcc' supported only on raw ATM");
|
|
b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0);
|
|
b1 = gen_atmfield_code_internal(cstate, A_VCI, 2, BPF_JEQ, 0);
|
|
gen_and(b0, b1);
|
|
break;
|
|
|
|
case A_OAMF4SC:
|
|
/* Get all cells in Segment OAM F4 circuit*/
|
|
if (!cstate->is_atm)
|
|
bpf_error(cstate, "'oam4sc' supported only on raw ATM");
|
|
b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0);
|
|
b1 = gen_atmfield_code_internal(cstate, A_VCI, 3, BPF_JEQ, 0);
|
|
gen_and(b0, b1);
|
|
break;
|
|
|
|
case A_OAMF4EC:
|
|
/* Get all cells in End-to-End OAM F4 Circuit*/
|
|
if (!cstate->is_atm)
|
|
bpf_error(cstate, "'oam4ec' supported only on raw ATM");
|
|
b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0);
|
|
b1 = gen_atmfield_code_internal(cstate, A_VCI, 4, BPF_JEQ, 0);
|
|
gen_and(b0, b1);
|
|
break;
|
|
|
|
case A_SC:
|
|
/* Get all packets in connection Signalling Circuit */
|
|
if (!cstate->is_atm)
|
|
bpf_error(cstate, "'sc' supported only on raw ATM");
|
|
b1 = gen_atmtype_sc(cstate);
|
|
break;
|
|
|
|
case A_ILMIC:
|
|
/* Get all packets in ILMI Circuit */
|
|
if (!cstate->is_atm)
|
|
bpf_error(cstate, "'ilmic' supported only on raw ATM");
|
|
b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0);
|
|
b1 = gen_atmfield_code_internal(cstate, A_VCI, 16, BPF_JEQ, 0);
|
|
gen_and(b0, b1);
|
|
break;
|
|
|
|
case A_LANE:
|
|
/* Get all LANE packets */
|
|
if (!cstate->is_atm)
|
|
bpf_error(cstate, "'lane' supported only on raw ATM");
|
|
b1 = gen_atmfield_code_internal(cstate, A_PROTOTYPE, PT_LANE, BPF_JEQ, 0);
|
|
|
|
/*
|
|
* Arrange that all subsequent tests assume LANE
|
|
* rather than LLC-encapsulated packets, and set
|
|
* the offsets appropriately for LANE-encapsulated
|
|
* Ethernet.
|
|
*
|
|
* We assume LANE means Ethernet, not Token Ring.
|
|
*/
|
|
PUSH_LINKHDR(cstate, DLT_EN10MB, 0,
|
|
cstate->off_payload + 2, /* Ethernet header */
|
|
-1);
|
|
cstate->off_linktype.constant_part = cstate->off_linkhdr.constant_part + 12;
|
|
cstate->off_linkpl.constant_part = cstate->off_linkhdr.constant_part + 14; /* Ethernet */
|
|
cstate->off_nl = 0; /* Ethernet II */
|
|
cstate->off_nl_nosnap = 3; /* 802.3+802.2 */
|
|
break;
|
|
|
|
case A_LLC:
|
|
/* Get all LLC-encapsulated packets */
|
|
if (!cstate->is_atm)
|
|
bpf_error(cstate, "'llc' supported only on raw ATM");
|
|
b1 = gen_atmtype_llc(cstate);
|
|
break;
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
return b1;
|
|
}
|
|
|
|
/*
|
|
* Filtering for MTP2 messages based on li value
|
|
* FISU, length is null
|
|
* LSSU, length is 1 or 2
|
|
* MSU, length is 3 or more
|
|
* For MTP2_HSL, sequences are on 2 bytes, and length on 9 bits
|
|
*/
|
|
struct block *
|
|
gen_mtp2type_abbrev(compiler_state_t *cstate, int type)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
switch (type) {
|
|
|
|
case M_FISU:
|
|
if ( (cstate->linktype != DLT_MTP2) &&
|
|
(cstate->linktype != DLT_ERF) &&
|
|
(cstate->linktype != DLT_MTP2_WITH_PHDR) )
|
|
bpf_error(cstate, "'fisu' supported only on MTP2");
|
|
/* gen_ncmp(cstate, offrel, offset, size, mask, jtype, reverse, value) */
|
|
b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B, 0x3f, BPF_JEQ, 0, 0);
|
|
break;
|
|
|
|
case M_LSSU:
|
|
if ( (cstate->linktype != DLT_MTP2) &&
|
|
(cstate->linktype != DLT_ERF) &&
|
|
(cstate->linktype != DLT_MTP2_WITH_PHDR) )
|
|
bpf_error(cstate, "'lssu' supported only on MTP2");
|
|
b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B, 0x3f, BPF_JGT, 1, 2);
|
|
b1 = gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B, 0x3f, BPF_JGT, 0, 0);
|
|
gen_and(b1, b0);
|
|
break;
|
|
|
|
case M_MSU:
|
|
if ( (cstate->linktype != DLT_MTP2) &&
|
|
(cstate->linktype != DLT_ERF) &&
|
|
(cstate->linktype != DLT_MTP2_WITH_PHDR) )
|
|
bpf_error(cstate, "'msu' supported only on MTP2");
|
|
b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B, 0x3f, BPF_JGT, 0, 2);
|
|
break;
|
|
|
|
case MH_FISU:
|
|
if ( (cstate->linktype != DLT_MTP2) &&
|
|
(cstate->linktype != DLT_ERF) &&
|
|
(cstate->linktype != DLT_MTP2_WITH_PHDR) )
|
|
bpf_error(cstate, "'hfisu' supported only on MTP2_HSL");
|
|
/* gen_ncmp(cstate, offrel, offset, size, mask, jtype, reverse, value) */
|
|
b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H, 0xff80, BPF_JEQ, 0, 0);
|
|
break;
|
|
|
|
case MH_LSSU:
|
|
if ( (cstate->linktype != DLT_MTP2) &&
|
|
(cstate->linktype != DLT_ERF) &&
|
|
(cstate->linktype != DLT_MTP2_WITH_PHDR) )
|
|
bpf_error(cstate, "'hlssu' supported only on MTP2_HSL");
|
|
b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H, 0xff80, BPF_JGT, 1, 0x0100);
|
|
b1 = gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H, 0xff80, BPF_JGT, 0, 0);
|
|
gen_and(b1, b0);
|
|
break;
|
|
|
|
case MH_MSU:
|
|
if ( (cstate->linktype != DLT_MTP2) &&
|
|
(cstate->linktype != DLT_ERF) &&
|
|
(cstate->linktype != DLT_MTP2_WITH_PHDR) )
|
|
bpf_error(cstate, "'hmsu' supported only on MTP2_HSL");
|
|
b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H, 0xff80, BPF_JGT, 0, 0x0100);
|
|
break;
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
return b0;
|
|
}
|
|
|
|
/*
|
|
* The jvalue_arg dance is to avoid annoying whining by compilers that
|
|
* jvalue might be clobbered by longjmp - yeah, it might, but *WHO CARES*?
|
|
* It's not *used* after setjmp returns.
|
|
*/
|
|
struct block *
|
|
gen_mtp3field_code(compiler_state_t *cstate, int mtp3field,
|
|
bpf_u_int32 jvalue_arg, bpf_u_int32 jtype, int reverse)
|
|
{
|
|
volatile bpf_u_int32 jvalue = jvalue_arg;
|
|
struct block *b0;
|
|
bpf_u_int32 val1 , val2 , val3;
|
|
u_int newoff_sio;
|
|
u_int newoff_opc;
|
|
u_int newoff_dpc;
|
|
u_int newoff_sls;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
newoff_sio = cstate->off_sio;
|
|
newoff_opc = cstate->off_opc;
|
|
newoff_dpc = cstate->off_dpc;
|
|
newoff_sls = cstate->off_sls;
|
|
switch (mtp3field) {
|
|
|
|
case MH_SIO:
|
|
newoff_sio += 3; /* offset for MTP2_HSL */
|
|
/* FALLTHROUGH */
|
|
|
|
case M_SIO:
|
|
if (cstate->off_sio == OFFSET_NOT_SET)
|
|
bpf_error(cstate, "'sio' supported only on SS7");
|
|
/* sio coded on 1 byte so max value 255 */
|
|
if(jvalue > 255)
|
|
bpf_error(cstate, "sio value %u too big; max value = 255",
|
|
jvalue);
|
|
b0 = gen_ncmp(cstate, OR_PACKET, newoff_sio, BPF_B, 0xffffffff,
|
|
(u_int)jtype, reverse, (u_int)jvalue);
|
|
break;
|
|
|
|
case MH_OPC:
|
|
newoff_opc += 3;
|
|
|
|
/* FALLTHROUGH */
|
|
case M_OPC:
|
|
if (cstate->off_opc == OFFSET_NOT_SET)
|
|
bpf_error(cstate, "'opc' supported only on SS7");
|
|
/* opc coded on 14 bits so max value 16383 */
|
|
if (jvalue > 16383)
|
|
bpf_error(cstate, "opc value %u too big; max value = 16383",
|
|
jvalue);
|
|
/* the following instructions are made to convert jvalue
|
|
* to the form used to write opc in an ss7 message*/
|
|
val1 = jvalue & 0x00003c00;
|
|
val1 = val1 >>10;
|
|
val2 = jvalue & 0x000003fc;
|
|
val2 = val2 <<6;
|
|
val3 = jvalue & 0x00000003;
|
|
val3 = val3 <<22;
|
|
jvalue = val1 + val2 + val3;
|
|
b0 = gen_ncmp(cstate, OR_PACKET, newoff_opc, BPF_W, 0x00c0ff0f,
|
|
(u_int)jtype, reverse, (u_int)jvalue);
|
|
break;
|
|
|
|
case MH_DPC:
|
|
newoff_dpc += 3;
|
|
/* FALLTHROUGH */
|
|
|
|
case M_DPC:
|
|
if (cstate->off_dpc == OFFSET_NOT_SET)
|
|
bpf_error(cstate, "'dpc' supported only on SS7");
|
|
/* dpc coded on 14 bits so max value 16383 */
|
|
if (jvalue > 16383)
|
|
bpf_error(cstate, "dpc value %u too big; max value = 16383",
|
|
jvalue);
|
|
/* the following instructions are made to convert jvalue
|
|
* to the forme used to write dpc in an ss7 message*/
|
|
val1 = jvalue & 0x000000ff;
|
|
val1 = val1 << 24;
|
|
val2 = jvalue & 0x00003f00;
|
|
val2 = val2 << 8;
|
|
jvalue = val1 + val2;
|
|
b0 = gen_ncmp(cstate, OR_PACKET, newoff_dpc, BPF_W, 0xff3f0000,
|
|
(u_int)jtype, reverse, (u_int)jvalue);
|
|
break;
|
|
|
|
case MH_SLS:
|
|
newoff_sls += 3;
|
|
/* FALLTHROUGH */
|
|
|
|
case M_SLS:
|
|
if (cstate->off_sls == OFFSET_NOT_SET)
|
|
bpf_error(cstate, "'sls' supported only on SS7");
|
|
/* sls coded on 4 bits so max value 15 */
|
|
if (jvalue > 15)
|
|
bpf_error(cstate, "sls value %u too big; max value = 15",
|
|
jvalue);
|
|
/* the following instruction is made to convert jvalue
|
|
* to the forme used to write sls in an ss7 message*/
|
|
jvalue = jvalue << 4;
|
|
b0 = gen_ncmp(cstate, OR_PACKET, newoff_sls, BPF_B, 0xf0,
|
|
(u_int)jtype,reverse, (u_int)jvalue);
|
|
break;
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
return b0;
|
|
}
|
|
|
|
static struct block *
|
|
gen_msg_abbrev(compiler_state_t *cstate, int type)
|
|
{
|
|
struct block *b1;
|
|
|
|
/*
|
|
* Q.2931 signalling protocol messages for handling virtual circuits
|
|
* establishment and teardown
|
|
*/
|
|
switch (type) {
|
|
|
|
case A_SETUP:
|
|
b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, SETUP, BPF_JEQ, 0);
|
|
break;
|
|
|
|
case A_CALLPROCEED:
|
|
b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, CALL_PROCEED, BPF_JEQ, 0);
|
|
break;
|
|
|
|
case A_CONNECT:
|
|
b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, CONNECT, BPF_JEQ, 0);
|
|
break;
|
|
|
|
case A_CONNECTACK:
|
|
b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, CONNECT_ACK, BPF_JEQ, 0);
|
|
break;
|
|
|
|
case A_RELEASE:
|
|
b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, RELEASE, BPF_JEQ, 0);
|
|
break;
|
|
|
|
case A_RELEASE_DONE:
|
|
b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, RELEASE_DONE, BPF_JEQ, 0);
|
|
break;
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
return b1;
|
|
}
|
|
|
|
struct block *
|
|
gen_atmmulti_abbrev(compiler_state_t *cstate, int type)
|
|
{
|
|
struct block *b0, *b1;
|
|
|
|
/*
|
|
* Catch errors reported by us and routines below us, and return NULL
|
|
* on an error.
|
|
*/
|
|
if (setjmp(cstate->top_ctx))
|
|
return (NULL);
|
|
|
|
switch (type) {
|
|
|
|
case A_OAM:
|
|
if (!cstate->is_atm)
|
|
bpf_error(cstate, "'oam' supported only on raw ATM");
|
|
/* OAM F4 type */
|
|
b0 = gen_atmfield_code_internal(cstate, A_VCI, 3, BPF_JEQ, 0);
|
|
b1 = gen_atmfield_code_internal(cstate, A_VCI, 4, BPF_JEQ, 0);
|
|
gen_or(b0, b1);
|
|
b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0);
|
|
gen_and(b0, b1);
|
|
break;
|
|
|
|
case A_OAMF4:
|
|
if (!cstate->is_atm)
|
|
bpf_error(cstate, "'oamf4' supported only on raw ATM");
|
|
/* OAM F4 type */
|
|
b0 = gen_atmfield_code_internal(cstate, A_VCI, 3, BPF_JEQ, 0);
|
|
b1 = gen_atmfield_code_internal(cstate, A_VCI, 4, BPF_JEQ, 0);
|
|
gen_or(b0, b1);
|
|
b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0);
|
|
gen_and(b0, b1);
|
|
break;
|
|
|
|
case A_CONNECTMSG:
|
|
/*
|
|
* Get Q.2931 signalling messages for switched
|
|
* virtual connection
|
|
*/
|
|
if (!cstate->is_atm)
|
|
bpf_error(cstate, "'connectmsg' supported only on raw ATM");
|
|
b0 = gen_msg_abbrev(cstate, A_SETUP);
|
|
b1 = gen_msg_abbrev(cstate, A_CALLPROCEED);
|
|
gen_or(b0, b1);
|
|
b0 = gen_msg_abbrev(cstate, A_CONNECT);
|
|
gen_or(b0, b1);
|
|
b0 = gen_msg_abbrev(cstate, A_CONNECTACK);
|
|
gen_or(b0, b1);
|
|
b0 = gen_msg_abbrev(cstate, A_RELEASE);
|
|
gen_or(b0, b1);
|
|
b0 = gen_msg_abbrev(cstate, A_RELEASE_DONE);
|
|
gen_or(b0, b1);
|
|
b0 = gen_atmtype_sc(cstate);
|
|
gen_and(b0, b1);
|
|
break;
|
|
|
|
case A_METACONNECT:
|
|
if (!cstate->is_atm)
|
|
bpf_error(cstate, "'metaconnect' supported only on raw ATM");
|
|
b0 = gen_msg_abbrev(cstate, A_SETUP);
|
|
b1 = gen_msg_abbrev(cstate, A_CALLPROCEED);
|
|
gen_or(b0, b1);
|
|
b0 = gen_msg_abbrev(cstate, A_CONNECT);
|
|
gen_or(b0, b1);
|
|
b0 = gen_msg_abbrev(cstate, A_RELEASE);
|
|
gen_or(b0, b1);
|
|
b0 = gen_msg_abbrev(cstate, A_RELEASE_DONE);
|
|
gen_or(b0, b1);
|
|
b0 = gen_atmtype_metac(cstate);
|
|
gen_and(b0, b1);
|
|
break;
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
return b1;
|
|
}
|