freebsd-skq/sys/netinet/ip_var.h
Jonathan T. Looney 2157f3c36a Add some additional length checks to the IPv4 fragmentation code.
Specifically, block 0-length fragments, even when the MF bit is clear.
Also, ensure that every fragment with the MF bit clear ends at the same
offset and that no subsequently-received fragments exceed that offset.

Reviewed by:	glebius, markj
MFC after:	3 days
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D17922
2018-11-16 18:32:48 +00:00

304 lines
12 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1982, 1986, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)ip_var.h 8.2 (Berkeley) 1/9/95
* $FreeBSD$
*/
#ifndef _NETINET_IP_VAR_H_
#define _NETINET_IP_VAR_H_
#include <sys/queue.h>
#include <sys/epoch.h>
/*
* Overlay for ip header used by other protocols (tcp, udp).
*/
struct ipovly {
u_char ih_x1[9]; /* (unused) */
u_char ih_pr; /* protocol */
u_short ih_len; /* protocol length */
struct in_addr ih_src; /* source internet address */
struct in_addr ih_dst; /* destination internet address */
};
#ifdef _KERNEL
/*
* Ip reassembly queue structure. Each fragment
* being reassembled is attached to one of these structures.
* They are timed out after ipq_ttl drops to 0, and may also
* be reclaimed if memory becomes tight.
*/
struct ipq {
TAILQ_ENTRY(ipq) ipq_list; /* to other reass headers */
u_char ipq_ttl; /* time for reass q to live */
u_char ipq_p; /* protocol of this fragment */
u_short ipq_id; /* sequence id for reassembly */
int ipq_maxoff; /* total length of packet */
struct mbuf *ipq_frags; /* to ip headers of fragments */
struct in_addr ipq_src,ipq_dst;
u_char ipq_nfrags; /* # frags in this packet */
struct label *ipq_label; /* MAC label */
};
#endif /* _KERNEL */
/*
* Structure stored in mbuf in inpcb.ip_options
* and passed to ip_output when ip options are in use.
* The actual length of the options (including ipopt_dst)
* is in m_len.
*/
#define MAX_IPOPTLEN 40
struct ipoption {
struct in_addr ipopt_dst; /* first-hop dst if source routed */
char ipopt_list[MAX_IPOPTLEN]; /* options proper */
};
/*
* Structure attached to inpcb.ip_moptions and
* passed to ip_output when IP multicast options are in use.
* This structure is lazy-allocated.
*/
struct ip_moptions {
struct ifnet *imo_multicast_ifp; /* ifp for outgoing multicasts */
struct in_addr imo_multicast_addr; /* ifindex/addr on MULTICAST_IF */
u_long imo_multicast_vif; /* vif num outgoing multicasts */
u_char imo_multicast_ttl; /* TTL for outgoing multicasts */
u_char imo_multicast_loop; /* 1 => hear sends if a member */
u_short imo_num_memberships; /* no. memberships this socket */
u_short imo_max_memberships; /* max memberships this socket */
struct in_multi **imo_membership; /* group memberships */
struct in_mfilter *imo_mfilters; /* source filters */
struct epoch_context imo_epoch_ctx;
};
struct ipstat {
uint64_t ips_total; /* total packets received */
uint64_t ips_badsum; /* checksum bad */
uint64_t ips_tooshort; /* packet too short */
uint64_t ips_toosmall; /* not enough data */
uint64_t ips_badhlen; /* ip header length < data size */
uint64_t ips_badlen; /* ip length < ip header length */
uint64_t ips_fragments; /* fragments received */
uint64_t ips_fragdropped; /* frags dropped (dups, out of space) */
uint64_t ips_fragtimeout; /* fragments timed out */
uint64_t ips_forward; /* packets forwarded */
uint64_t ips_fastforward; /* packets fast forwarded */
uint64_t ips_cantforward; /* packets rcvd for unreachable dest */
uint64_t ips_redirectsent; /* packets forwarded on same net */
uint64_t ips_noproto; /* unknown or unsupported protocol */
uint64_t ips_delivered; /* datagrams delivered to upper level*/
uint64_t ips_localout; /* total ip packets generated here */
uint64_t ips_odropped; /* lost packets due to nobufs, etc. */
uint64_t ips_reassembled; /* total packets reassembled ok */
uint64_t ips_fragmented; /* datagrams successfully fragmented */
uint64_t ips_ofragments; /* output fragments created */
uint64_t ips_cantfrag; /* don't fragment flag was set, etc. */
uint64_t ips_badoptions; /* error in option processing */
uint64_t ips_noroute; /* packets discarded due to no route */
uint64_t ips_badvers; /* ip version != 4 */
uint64_t ips_rawout; /* total raw ip packets generated */
uint64_t ips_toolong; /* ip length > max ip packet size */
uint64_t ips_notmember; /* multicasts for unregistered grps */
uint64_t ips_nogif; /* no match gif found */
uint64_t ips_badaddr; /* invalid address on header */
};
#ifdef _KERNEL
#include <sys/counter.h>
#include <net/vnet.h>
VNET_PCPUSTAT_DECLARE(struct ipstat, ipstat);
/*
* In-kernel consumers can use these accessor macros directly to update
* stats.
*/
#define IPSTAT_ADD(name, val) \
VNET_PCPUSTAT_ADD(struct ipstat, ipstat, name, (val))
#define IPSTAT_SUB(name, val) IPSTAT_ADD(name, -(val))
#define IPSTAT_INC(name) IPSTAT_ADD(name, 1)
#define IPSTAT_DEC(name) IPSTAT_SUB(name, 1)
/*
* Kernel module consumers must use this accessor macro.
*/
void kmod_ipstat_inc(int statnum);
#define KMOD_IPSTAT_INC(name) \
kmod_ipstat_inc(offsetof(struct ipstat, name) / sizeof(uint64_t))
void kmod_ipstat_dec(int statnum);
#define KMOD_IPSTAT_DEC(name) \
kmod_ipstat_dec(offsetof(struct ipstat, name) / sizeof(uint64_t))
/* flags passed to ip_output as last parameter */
#define IP_FORWARDING 0x1 /* most of ip header exists */
#define IP_RAWOUTPUT 0x2 /* raw ip header exists */
#define IP_SENDONES 0x4 /* send all-ones broadcast */
#define IP_SENDTOIF 0x8 /* send on specific ifnet */
#define IP_ROUTETOIF SO_DONTROUTE /* 0x10 bypass routing tables */
#define IP_ALLOWBROADCAST SO_BROADCAST /* 0x20 can send broadcast packets */
#define IP_NODEFAULTFLOWID 0x40 /* Don't set the flowid from inp */
#ifdef __NO_STRICT_ALIGNMENT
#define IP_HDR_ALIGNED_P(ip) 1
#else
#define IP_HDR_ALIGNED_P(ip) ((((intptr_t) (ip)) & 3) == 0)
#endif
struct ip;
struct inpcb;
struct route;
struct sockopt;
struct inpcbinfo;
VNET_DECLARE(int, ip_defttl); /* default IP ttl */
VNET_DECLARE(int, ipforwarding); /* ip forwarding */
#ifdef IPSTEALTH
VNET_DECLARE(int, ipstealth); /* stealth forwarding */
#endif
extern u_char ip_protox[];
VNET_DECLARE(struct socket *, ip_rsvpd); /* reservation protocol daemon*/
VNET_DECLARE(struct socket *, ip_mrouter); /* multicast routing daemon */
extern int (*legal_vif_num)(int);
extern u_long (*ip_mcast_src)(int);
VNET_DECLARE(int, rsvp_on);
VNET_DECLARE(int, drop_redirect);
extern struct pr_usrreqs rip_usrreqs;
#define V_ip_id VNET(ip_id)
#define V_ip_defttl VNET(ip_defttl)
#define V_ipforwarding VNET(ipforwarding)
#ifdef IPSTEALTH
#define V_ipstealth VNET(ipstealth)
#endif
#define V_ip_rsvpd VNET(ip_rsvpd)
#define V_ip_mrouter VNET(ip_mrouter)
#define V_rsvp_on VNET(rsvp_on)
#define V_drop_redirect VNET(drop_redirect)
void inp_freemoptions(struct ip_moptions *);
int inp_getmoptions(struct inpcb *, struct sockopt *);
int inp_setmoptions(struct inpcb *, struct sockopt *);
int ip_ctloutput(struct socket *, struct sockopt *sopt);
void ip_drain(void);
int ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
u_long if_hwassist_flags);
void ip_forward(struct mbuf *m, int srcrt);
void ip_init(void);
extern int
(*ip_mforward)(struct ip *, struct ifnet *, struct mbuf *,
struct ip_moptions *);
int ip_output(struct mbuf *,
struct mbuf *, struct route *, int, struct ip_moptions *,
struct inpcb *);
int ipproto_register(short);
int ipproto_unregister(short);
struct mbuf *
ip_reass(struct mbuf *);
void ip_savecontrol(struct inpcb *, struct mbuf **, struct ip *,
struct mbuf *);
void ip_slowtimo(void);
void ip_fillid(struct ip *);
int rip_ctloutput(struct socket *, struct sockopt *);
void rip_ctlinput(int, struct sockaddr *, void *);
void rip_init(void);
int rip_input(struct mbuf **, int *, int);
int rip_output(struct mbuf *, struct socket *, ...);
int ipip_input(struct mbuf **, int *, int);
int rsvp_input(struct mbuf **, int *, int);
int ip_rsvp_init(struct socket *);
int ip_rsvp_done(void);
extern int (*ip_rsvp_vif)(struct socket *, struct sockopt *);
extern void (*ip_rsvp_force_done)(struct socket *);
extern int (*rsvp_input_p)(struct mbuf **, int *, int);
VNET_DECLARE(struct pfil_head, inet_pfil_hook); /* packet filter hooks */
#define V_inet_pfil_hook VNET(inet_pfil_hook)
void in_delayed_cksum(struct mbuf *m);
/* Hooks for ipfw, dummynet, divert etc. Most are declared in raw_ip.c */
/*
* Reference to an ipfw or packet filter rule that can be carried
* outside critical sections.
* A rule is identified by rulenum:rule_id which is ordered.
* In version chain_id the rule can be found in slot 'slot', so
* we don't need a lookup if chain_id == chain->id.
*
* On exit from the firewall this structure refers to the rule after
* the matching one (slot points to the new rule; rulenum:rule_id-1
* is the matching rule), and additional info (e.g. info often contains
* the insn argument or tablearg in the low 16 bits, in host format).
* On entry, the structure is valid if slot>0, and refers to the starting
* rules. 'info' contains the reason for reinject, e.g. divert port,
* divert direction, and so on.
*/
struct ipfw_rule_ref {
uint32_t slot; /* slot for matching rule */
uint32_t rulenum; /* matching rule number */
uint32_t rule_id; /* matching rule id */
uint32_t chain_id; /* ruleset id */
uint32_t info; /* see below */
};
enum {
IPFW_INFO_MASK = 0x0000ffff,
IPFW_INFO_OUT = 0x00000000, /* outgoing, just for convenience */
IPFW_INFO_IN = 0x80000000, /* incoming, overloads dir */
IPFW_ONEPASS = 0x40000000, /* One-pass, do not reinject */
IPFW_IS_MASK = 0x30000000, /* which source ? */
IPFW_IS_DIVERT = 0x20000000,
IPFW_IS_DUMMYNET =0x10000000,
IPFW_IS_PIPE = 0x08000000, /* pipe=1, queue = 0 */
};
#define MTAG_IPFW 1148380143 /* IPFW-tagged cookie */
#define MTAG_IPFW_RULE 1262273568 /* rule reference */
#define MTAG_IPFW_CALL 1308397630 /* call stack */
struct ip_fw_args;
typedef int (*ip_fw_chk_ptr_t)(struct ip_fw_args *args);
typedef int (*ip_fw_ctl_ptr_t)(struct sockopt *);
VNET_DECLARE(ip_fw_ctl_ptr_t, ip_fw_ctl_ptr);
#define V_ip_fw_ctl_ptr VNET(ip_fw_ctl_ptr)
/* Divert hooks. */
extern void (*ip_divert_ptr)(struct mbuf *m, int incoming);
/* ng_ipfw hooks -- XXX make it the same as divert and dummynet */
extern int (*ng_ipfw_input_p)(struct mbuf **, int,
struct ip_fw_args *, int);
extern int (*ip_dn_ctl_ptr)(struct sockopt *);
extern int (*ip_dn_io_ptr)(struct mbuf **, int, struct ip_fw_args *);
#endif /* _KERNEL */
#endif /* !_NETINET_IP_VAR_H_ */