2792 lines
73 KiB
C
2792 lines
73 KiB
C
/*-
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* Copyright (c) 2002-2009 Luigi Rizzo, Universita` di Pisa
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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 the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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/*
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* The FreeBSD IP packet firewall, main file
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*/
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#include "opt_ipfw.h"
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#include "opt_ipdivert.h"
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#include "opt_inet.h"
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#ifndef INET
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#error "IPFIREWALL requires INET"
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#endif /* INET */
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#include "opt_inet6.h"
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#include "opt_ipsec.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/condvar.h>
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#include <sys/eventhandler.h>
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#include <sys/malloc.h>
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#include <sys/mbuf.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/jail.h>
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#include <sys/module.h>
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#include <sys/priv.h>
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#include <sys/proc.h>
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#include <sys/rwlock.h>
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#include <sys/socket.h>
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#include <sys/socketvar.h>
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#include <sys/sysctl.h>
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#include <sys/syslog.h>
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#include <sys/ucred.h>
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#include <net/ethernet.h> /* for ETHERTYPE_IP */
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#include <net/if.h>
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#include <net/route.h>
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#include <net/pf_mtag.h>
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#include <net/vnet.h>
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#include <netinet/in.h>
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#include <netinet/in_var.h>
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#include <netinet/in_pcb.h>
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#include <netinet/ip.h>
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#include <netinet/ip_var.h>
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#include <netinet/ip_icmp.h>
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#include <netinet/ip_fw.h>
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#include <netinet/ip_carp.h>
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#include <netinet/pim.h>
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#include <netinet/tcp_var.h>
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#include <netinet/udp.h>
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#include <netinet/udp_var.h>
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#include <netinet/sctp.h>
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#include <netinet/ip6.h>
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#include <netinet/icmp6.h>
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#ifdef INET6
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#include <netinet6/in6_pcb.h>
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#include <netinet6/scope6_var.h>
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#include <netinet6/ip6_var.h>
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#endif
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#include <netpfil/ipfw/ip_fw_private.h>
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#include <machine/in_cksum.h> /* XXX for in_cksum */
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#ifdef MAC
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#include <security/mac/mac_framework.h>
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#endif
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/*
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* static variables followed by global ones.
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* All ipfw global variables are here.
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*/
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/* ipfw_vnet_ready controls when we are open for business */
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static VNET_DEFINE(int, ipfw_vnet_ready) = 0;
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#define V_ipfw_vnet_ready VNET(ipfw_vnet_ready)
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static VNET_DEFINE(int, fw_deny_unknown_exthdrs);
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#define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs)
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static VNET_DEFINE(int, fw_permit_single_frag6) = 1;
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#define V_fw_permit_single_frag6 VNET(fw_permit_single_frag6)
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#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
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static int default_to_accept = 1;
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#else
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static int default_to_accept;
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#endif
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VNET_DEFINE(int, autoinc_step);
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VNET_DEFINE(int, fw_one_pass) = 1;
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VNET_DEFINE(unsigned int, fw_tables_max);
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/* Use 128 tables by default */
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static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT;
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/*
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* Each rule belongs to one of 32 different sets (0..31).
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* The variable set_disable contains one bit per set.
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* If the bit is set, all rules in the corresponding set
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* are disabled. Set RESVD_SET(31) is reserved for the default rule
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* and rules that are not deleted by the flush command,
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* and CANNOT be disabled.
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* Rules in set RESVD_SET can only be deleted individually.
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*/
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VNET_DEFINE(u_int32_t, set_disable);
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#define V_set_disable VNET(set_disable)
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VNET_DEFINE(int, fw_verbose);
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/* counter for ipfw_log(NULL...) */
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VNET_DEFINE(u_int64_t, norule_counter);
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VNET_DEFINE(int, verbose_limit);
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/* layer3_chain contains the list of rules for layer 3 */
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VNET_DEFINE(struct ip_fw_chain, layer3_chain);
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ipfw_nat_t *ipfw_nat_ptr = NULL;
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struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int);
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ipfw_nat_cfg_t *ipfw_nat_cfg_ptr;
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ipfw_nat_cfg_t *ipfw_nat_del_ptr;
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ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr;
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ipfw_nat_cfg_t *ipfw_nat_get_log_ptr;
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#ifdef SYSCTL_NODE
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uint32_t dummy_def = IPFW_DEFAULT_RULE;
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static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS);
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SYSBEGIN(f3)
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SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
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SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, one_pass,
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CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0,
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"Only do a single pass through ipfw when using dummynet(4)");
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SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step,
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CTLFLAG_RW, &VNET_NAME(autoinc_step), 0,
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"Rule number auto-increment step");
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SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose,
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CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0,
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"Log matches to ipfw rules");
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SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit,
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CTLFLAG_RW, &VNET_NAME(verbose_limit), 0,
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"Set upper limit of matches of ipfw rules logged");
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SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD,
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&dummy_def, 0,
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"The default/max possible rule number.");
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SYSCTL_VNET_PROC(_net_inet_ip_fw, OID_AUTO, tables_max,
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CTLTYPE_UINT|CTLFLAG_RW, 0, 0, sysctl_ipfw_table_num, "IU",
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"Maximum number of tables");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN,
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&default_to_accept, 0,
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"Make the default rule accept all packets.");
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TUNABLE_INT("net.inet.ip.fw.default_to_accept", &default_to_accept);
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TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables);
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SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, static_count,
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CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0,
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"Number of static rules");
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#ifdef INET6
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SYSCTL_DECL(_net_inet6_ip6);
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SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
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SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs,
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CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_deny_unknown_exthdrs), 0,
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"Deny packets with unknown IPv6 Extension Headers");
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SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6,
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CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_permit_single_frag6), 0,
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"Permit single packet IPv6 fragments");
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#endif /* INET6 */
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SYSEND
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#endif /* SYSCTL_NODE */
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/*
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* Some macros used in the various matching options.
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* L3HDR maps an ipv4 pointer into a layer3 header pointer of type T
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* Other macros just cast void * into the appropriate type
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*/
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#define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl))
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#define TCP(p) ((struct tcphdr *)(p))
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#define SCTP(p) ((struct sctphdr *)(p))
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#define UDP(p) ((struct udphdr *)(p))
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#define ICMP(p) ((struct icmphdr *)(p))
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#define ICMP6(p) ((struct icmp6_hdr *)(p))
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static __inline int
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icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd)
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{
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int type = icmp->icmp_type;
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return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) );
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}
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#define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \
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(1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) )
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static int
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is_icmp_query(struct icmphdr *icmp)
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{
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int type = icmp->icmp_type;
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return (type <= ICMP_MAXTYPE && (TT & (1<<type)) );
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}
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#undef TT
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/*
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* The following checks use two arrays of 8 or 16 bits to store the
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* bits that we want set or clear, respectively. They are in the
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* low and high half of cmd->arg1 or cmd->d[0].
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*
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* We scan options and store the bits we find set. We succeed if
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*
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* (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear
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*
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* The code is sometimes optimized not to store additional variables.
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*/
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static int
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flags_match(ipfw_insn *cmd, u_int8_t bits)
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{
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u_char want_clear;
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bits = ~bits;
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if ( ((cmd->arg1 & 0xff) & bits) != 0)
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return 0; /* some bits we want set were clear */
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want_clear = (cmd->arg1 >> 8) & 0xff;
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if ( (want_clear & bits) != want_clear)
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return 0; /* some bits we want clear were set */
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return 1;
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}
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static int
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ipopts_match(struct ip *ip, ipfw_insn *cmd)
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{
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int optlen, bits = 0;
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u_char *cp = (u_char *)(ip + 1);
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int x = (ip->ip_hl << 2) - sizeof (struct ip);
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for (; x > 0; x -= optlen, cp += optlen) {
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int opt = cp[IPOPT_OPTVAL];
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if (opt == IPOPT_EOL)
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break;
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if (opt == IPOPT_NOP)
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optlen = 1;
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else {
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optlen = cp[IPOPT_OLEN];
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if (optlen <= 0 || optlen > x)
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return 0; /* invalid or truncated */
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}
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switch (opt) {
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default:
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break;
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case IPOPT_LSRR:
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bits |= IP_FW_IPOPT_LSRR;
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break;
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case IPOPT_SSRR:
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bits |= IP_FW_IPOPT_SSRR;
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break;
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case IPOPT_RR:
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bits |= IP_FW_IPOPT_RR;
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break;
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case IPOPT_TS:
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bits |= IP_FW_IPOPT_TS;
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break;
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}
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}
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return (flags_match(cmd, bits));
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}
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static int
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tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd)
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{
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int optlen, bits = 0;
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u_char *cp = (u_char *)(tcp + 1);
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int x = (tcp->th_off << 2) - sizeof(struct tcphdr);
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for (; x > 0; x -= optlen, cp += optlen) {
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int opt = cp[0];
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if (opt == TCPOPT_EOL)
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break;
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if (opt == TCPOPT_NOP)
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optlen = 1;
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else {
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optlen = cp[1];
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if (optlen <= 0)
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break;
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}
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switch (opt) {
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default:
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break;
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case TCPOPT_MAXSEG:
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bits |= IP_FW_TCPOPT_MSS;
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break;
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case TCPOPT_WINDOW:
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bits |= IP_FW_TCPOPT_WINDOW;
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break;
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case TCPOPT_SACK_PERMITTED:
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case TCPOPT_SACK:
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bits |= IP_FW_TCPOPT_SACK;
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break;
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case TCPOPT_TIMESTAMP:
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bits |= IP_FW_TCPOPT_TS;
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break;
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}
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}
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return (flags_match(cmd, bits));
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}
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static int
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iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain, uint32_t *tablearg)
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{
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if (ifp == NULL) /* no iface with this packet, match fails */
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return 0;
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/* Check by name or by IP address */
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if (cmd->name[0] != '\0') { /* match by name */
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if (cmd->name[0] == '\1') /* use tablearg to match */
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return ipfw_lookup_table_extended(chain, cmd->p.glob,
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ifp->if_xname, tablearg, IPFW_TABLE_INTERFACE);
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/* Check name */
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if (cmd->p.glob) {
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if (fnmatch(cmd->name, ifp->if_xname, 0) == 0)
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return(1);
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} else {
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if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0)
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return(1);
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}
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} else {
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#ifdef __FreeBSD__ /* and OSX too ? */
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struct ifaddr *ia;
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if_addr_rlock(ifp);
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TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
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if (ia->ifa_addr->sa_family != AF_INET)
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continue;
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if (cmd->p.ip.s_addr == ((struct sockaddr_in *)
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(ia->ifa_addr))->sin_addr.s_addr) {
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if_addr_runlock(ifp);
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return(1); /* match */
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}
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}
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if_addr_runlock(ifp);
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#endif /* __FreeBSD__ */
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}
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return(0); /* no match, fail ... */
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}
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/*
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* The verify_path function checks if a route to the src exists and
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* if it is reachable via ifp (when provided).
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*
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* The 'verrevpath' option checks that the interface that an IP packet
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* arrives on is the same interface that traffic destined for the
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* packet's source address would be routed out of.
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* The 'versrcreach' option just checks that the source address is
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* reachable via any route (except default) in the routing table.
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* These two are a measure to block forged packets. This is also
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* commonly known as "anti-spoofing" or Unicast Reverse Path
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* Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs
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* is purposely reminiscent of the Cisco IOS command,
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*
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* ip verify unicast reverse-path
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* ip verify unicast source reachable-via any
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*
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* which implements the same functionality. But note that the syntax
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* is misleading, and the check may be performed on all IP packets
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* whether unicast, multicast, or broadcast.
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*/
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static int
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verify_path(struct in_addr src, struct ifnet *ifp, u_int fib)
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{
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#ifndef __FreeBSD__
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return 0;
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#else
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struct route ro;
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struct sockaddr_in *dst;
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bzero(&ro, sizeof(ro));
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dst = (struct sockaddr_in *)&(ro.ro_dst);
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dst->sin_family = AF_INET;
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dst->sin_len = sizeof(*dst);
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dst->sin_addr = src;
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in_rtalloc_ign(&ro, 0, fib);
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if (ro.ro_rt == NULL)
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return 0;
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/*
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* If ifp is provided, check for equality with rtentry.
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* We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
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* in order to pass packets injected back by if_simloop():
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* if useloopback == 1 routing entry (via lo0) for our own address
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* may exist, so we need to handle routing assymetry.
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*/
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if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) {
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RTFREE(ro.ro_rt);
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return 0;
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}
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/* if no ifp provided, check if rtentry is not default route */
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if (ifp == NULL &&
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satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) {
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RTFREE(ro.ro_rt);
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return 0;
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}
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/* or if this is a blackhole/reject route */
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if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
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RTFREE(ro.ro_rt);
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return 0;
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}
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/* found valid route */
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RTFREE(ro.ro_rt);
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return 1;
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#endif /* __FreeBSD__ */
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}
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#ifdef INET6
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/*
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* ipv6 specific rules here...
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*/
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static __inline int
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icmp6type_match (int type, ipfw_insn_u32 *cmd)
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{
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return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) );
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}
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static int
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flow6id_match( int curr_flow, ipfw_insn_u32 *cmd )
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{
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int i;
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for (i=0; i <= cmd->o.arg1; ++i )
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if (curr_flow == cmd->d[i] )
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return 1;
|
|
return 0;
|
|
}
|
|
|
|
/* support for IP6_*_ME opcodes */
|
|
static int
|
|
search_ip6_addr_net (struct in6_addr * ip6_addr)
|
|
{
|
|
struct ifnet *mdc;
|
|
struct ifaddr *mdc2;
|
|
struct in6_ifaddr *fdm;
|
|
struct in6_addr copia;
|
|
|
|
TAILQ_FOREACH(mdc, &V_ifnet, if_link) {
|
|
if_addr_rlock(mdc);
|
|
TAILQ_FOREACH(mdc2, &mdc->if_addrhead, ifa_link) {
|
|
if (mdc2->ifa_addr->sa_family == AF_INET6) {
|
|
fdm = (struct in6_ifaddr *)mdc2;
|
|
copia = fdm->ia_addr.sin6_addr;
|
|
/* need for leaving scope_id in the sock_addr */
|
|
in6_clearscope(&copia);
|
|
if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) {
|
|
if_addr_runlock(mdc);
|
|
return 1;
|
|
}
|
|
}
|
|
}
|
|
if_addr_runlock(mdc);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib)
|
|
{
|
|
struct route_in6 ro;
|
|
struct sockaddr_in6 *dst;
|
|
|
|
bzero(&ro, sizeof(ro));
|
|
|
|
dst = (struct sockaddr_in6 * )&(ro.ro_dst);
|
|
dst->sin6_family = AF_INET6;
|
|
dst->sin6_len = sizeof(*dst);
|
|
dst->sin6_addr = *src;
|
|
|
|
in6_rtalloc_ign(&ro, 0, fib);
|
|
if (ro.ro_rt == NULL)
|
|
return 0;
|
|
|
|
/*
|
|
* if ifp is provided, check for equality with rtentry
|
|
* We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
|
|
* to support the case of sending packets to an address of our own.
|
|
* (where the former interface is the first argument of if_simloop()
|
|
* (=ifp), the latter is lo0)
|
|
*/
|
|
if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) {
|
|
RTFREE(ro.ro_rt);
|
|
return 0;
|
|
}
|
|
|
|
/* if no ifp provided, check if rtentry is not default route */
|
|
if (ifp == NULL &&
|
|
IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) {
|
|
RTFREE(ro.ro_rt);
|
|
return 0;
|
|
}
|
|
|
|
/* or if this is a blackhole/reject route */
|
|
if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
|
|
RTFREE(ro.ro_rt);
|
|
return 0;
|
|
}
|
|
|
|
/* found valid route */
|
|
RTFREE(ro.ro_rt);
|
|
return 1;
|
|
|
|
}
|
|
|
|
static int
|
|
is_icmp6_query(int icmp6_type)
|
|
{
|
|
if ((icmp6_type <= ICMP6_MAXTYPE) &&
|
|
(icmp6_type == ICMP6_ECHO_REQUEST ||
|
|
icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
|
|
icmp6_type == ICMP6_WRUREQUEST ||
|
|
icmp6_type == ICMP6_FQDN_QUERY ||
|
|
icmp6_type == ICMP6_NI_QUERY))
|
|
return (1);
|
|
|
|
return (0);
|
|
}
|
|
|
|
static void
|
|
send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6)
|
|
{
|
|
struct mbuf *m;
|
|
|
|
m = args->m;
|
|
if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) {
|
|
struct tcphdr *tcp;
|
|
tcp = (struct tcphdr *)((char *)ip6 + hlen);
|
|
|
|
if ((tcp->th_flags & TH_RST) == 0) {
|
|
struct mbuf *m0;
|
|
m0 = ipfw_send_pkt(args->m, &(args->f_id),
|
|
ntohl(tcp->th_seq), ntohl(tcp->th_ack),
|
|
tcp->th_flags | TH_RST);
|
|
if (m0 != NULL)
|
|
ip6_output(m0, NULL, NULL, 0, NULL, NULL,
|
|
NULL);
|
|
}
|
|
FREE_PKT(m);
|
|
} else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */
|
|
#if 0
|
|
/*
|
|
* Unlike above, the mbufs need to line up with the ip6 hdr,
|
|
* as the contents are read. We need to m_adj() the
|
|
* needed amount.
|
|
* The mbuf will however be thrown away so we can adjust it.
|
|
* Remember we did an m_pullup on it already so we
|
|
* can make some assumptions about contiguousness.
|
|
*/
|
|
if (args->L3offset)
|
|
m_adj(m, args->L3offset);
|
|
#endif
|
|
icmp6_error(m, ICMP6_DST_UNREACH, code, 0);
|
|
} else
|
|
FREE_PKT(m);
|
|
|
|
args->m = NULL;
|
|
}
|
|
|
|
#endif /* INET6 */
|
|
|
|
|
|
/*
|
|
* sends a reject message, consuming the mbuf passed as an argument.
|
|
*/
|
|
static void
|
|
send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip)
|
|
{
|
|
|
|
#if 0
|
|
/* XXX When ip is not guaranteed to be at mtod() we will
|
|
* need to account for this */
|
|
* The mbuf will however be thrown away so we can adjust it.
|
|
* Remember we did an m_pullup on it already so we
|
|
* can make some assumptions about contiguousness.
|
|
*/
|
|
if (args->L3offset)
|
|
m_adj(m, args->L3offset);
|
|
#endif
|
|
if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */
|
|
/* We need the IP header in host order for icmp_error(). */
|
|
SET_HOST_IPLEN(ip);
|
|
icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
|
|
} else if (args->f_id.proto == IPPROTO_TCP) {
|
|
struct tcphdr *const tcp =
|
|
L3HDR(struct tcphdr, mtod(args->m, struct ip *));
|
|
if ( (tcp->th_flags & TH_RST) == 0) {
|
|
struct mbuf *m;
|
|
m = ipfw_send_pkt(args->m, &(args->f_id),
|
|
ntohl(tcp->th_seq), ntohl(tcp->th_ack),
|
|
tcp->th_flags | TH_RST);
|
|
if (m != NULL)
|
|
ip_output(m, NULL, NULL, 0, NULL, NULL);
|
|
}
|
|
FREE_PKT(args->m);
|
|
} else
|
|
FREE_PKT(args->m);
|
|
args->m = NULL;
|
|
}
|
|
|
|
/*
|
|
* Support for uid/gid/jail lookup. These tests are expensive
|
|
* (because we may need to look into the list of active sockets)
|
|
* so we cache the results. ugid_lookupp is 0 if we have not
|
|
* yet done a lookup, 1 if we succeeded, and -1 if we tried
|
|
* and failed. The function always returns the match value.
|
|
* We could actually spare the variable and use *uc, setting
|
|
* it to '(void *)check_uidgid if we have no info, NULL if
|
|
* we tried and failed, or any other value if successful.
|
|
*/
|
|
static int
|
|
check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp,
|
|
struct ucred **uc)
|
|
{
|
|
#ifndef __FreeBSD__
|
|
/* XXX */
|
|
return cred_check(insn, proto, oif,
|
|
dst_ip, dst_port, src_ip, src_port,
|
|
(struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb);
|
|
#else /* FreeBSD */
|
|
struct in_addr src_ip, dst_ip;
|
|
struct inpcbinfo *pi;
|
|
struct ipfw_flow_id *id;
|
|
struct inpcb *pcb, *inp;
|
|
struct ifnet *oif;
|
|
int lookupflags;
|
|
int match;
|
|
|
|
id = &args->f_id;
|
|
inp = args->inp;
|
|
oif = args->oif;
|
|
|
|
/*
|
|
* Check to see if the UDP or TCP stack supplied us with
|
|
* the PCB. If so, rather then holding a lock and looking
|
|
* up the PCB, we can use the one that was supplied.
|
|
*/
|
|
if (inp && *ugid_lookupp == 0) {
|
|
INP_LOCK_ASSERT(inp);
|
|
if (inp->inp_socket != NULL) {
|
|
*uc = crhold(inp->inp_cred);
|
|
*ugid_lookupp = 1;
|
|
} else
|
|
*ugid_lookupp = -1;
|
|
}
|
|
/*
|
|
* If we have already been here and the packet has no
|
|
* PCB entry associated with it, then we can safely
|
|
* assume that this is a no match.
|
|
*/
|
|
if (*ugid_lookupp == -1)
|
|
return (0);
|
|
if (id->proto == IPPROTO_TCP) {
|
|
lookupflags = 0;
|
|
pi = &V_tcbinfo;
|
|
} else if (id->proto == IPPROTO_UDP) {
|
|
lookupflags = INPLOOKUP_WILDCARD;
|
|
pi = &V_udbinfo;
|
|
} else
|
|
return 0;
|
|
lookupflags |= INPLOOKUP_RLOCKPCB;
|
|
match = 0;
|
|
if (*ugid_lookupp == 0) {
|
|
if (id->addr_type == 6) {
|
|
#ifdef INET6
|
|
if (oif == NULL)
|
|
pcb = in6_pcblookup_mbuf(pi,
|
|
&id->src_ip6, htons(id->src_port),
|
|
&id->dst_ip6, htons(id->dst_port),
|
|
lookupflags, oif, args->m);
|
|
else
|
|
pcb = in6_pcblookup_mbuf(pi,
|
|
&id->dst_ip6, htons(id->dst_port),
|
|
&id->src_ip6, htons(id->src_port),
|
|
lookupflags, oif, args->m);
|
|
#else
|
|
*ugid_lookupp = -1;
|
|
return (0);
|
|
#endif
|
|
} else {
|
|
src_ip.s_addr = htonl(id->src_ip);
|
|
dst_ip.s_addr = htonl(id->dst_ip);
|
|
if (oif == NULL)
|
|
pcb = in_pcblookup_mbuf(pi,
|
|
src_ip, htons(id->src_port),
|
|
dst_ip, htons(id->dst_port),
|
|
lookupflags, oif, args->m);
|
|
else
|
|
pcb = in_pcblookup_mbuf(pi,
|
|
dst_ip, htons(id->dst_port),
|
|
src_ip, htons(id->src_port),
|
|
lookupflags, oif, args->m);
|
|
}
|
|
if (pcb != NULL) {
|
|
INP_RLOCK_ASSERT(pcb);
|
|
*uc = crhold(pcb->inp_cred);
|
|
*ugid_lookupp = 1;
|
|
INP_RUNLOCK(pcb);
|
|
}
|
|
if (*ugid_lookupp == 0) {
|
|
/*
|
|
* We tried and failed, set the variable to -1
|
|
* so we will not try again on this packet.
|
|
*/
|
|
*ugid_lookupp = -1;
|
|
return (0);
|
|
}
|
|
}
|
|
if (insn->o.opcode == O_UID)
|
|
match = ((*uc)->cr_uid == (uid_t)insn->d[0]);
|
|
else if (insn->o.opcode == O_GID)
|
|
match = groupmember((gid_t)insn->d[0], *uc);
|
|
else if (insn->o.opcode == O_JAIL)
|
|
match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]);
|
|
return (match);
|
|
#endif /* __FreeBSD__ */
|
|
}
|
|
|
|
/*
|
|
* Helper function to set args with info on the rule after the matching
|
|
* one. slot is precise, whereas we guess rule_id as they are
|
|
* assigned sequentially.
|
|
*/
|
|
static inline void
|
|
set_match(struct ip_fw_args *args, int slot,
|
|
struct ip_fw_chain *chain)
|
|
{
|
|
args->rule.chain_id = chain->id;
|
|
args->rule.slot = slot + 1; /* we use 0 as a marker */
|
|
args->rule.rule_id = 1 + chain->map[slot]->id;
|
|
args->rule.rulenum = chain->map[slot]->rulenum;
|
|
}
|
|
|
|
/*
|
|
* The main check routine for the firewall.
|
|
*
|
|
* All arguments are in args so we can modify them and return them
|
|
* back to the caller.
|
|
*
|
|
* Parameters:
|
|
*
|
|
* args->m (in/out) The packet; we set to NULL when/if we nuke it.
|
|
* Starts with the IP header.
|
|
* args->eh (in) Mac header if present, NULL for layer3 packet.
|
|
* args->L3offset Number of bytes bypassed if we came from L2.
|
|
* e.g. often sizeof(eh) ** NOTYET **
|
|
* args->oif Outgoing interface, NULL if packet is incoming.
|
|
* The incoming interface is in the mbuf. (in)
|
|
* args->divert_rule (in/out)
|
|
* Skip up to the first rule past this rule number;
|
|
* upon return, non-zero port number for divert or tee.
|
|
*
|
|
* args->rule Pointer to the last matching rule (in/out)
|
|
* args->next_hop Socket we are forwarding to (out).
|
|
* args->next_hop6 IPv6 next hop we are forwarding to (out).
|
|
* args->f_id Addresses grabbed from the packet (out)
|
|
* args->rule.info a cookie depending on rule action
|
|
*
|
|
* Return value:
|
|
*
|
|
* IP_FW_PASS the packet must be accepted
|
|
* IP_FW_DENY the packet must be dropped
|
|
* IP_FW_DIVERT divert packet, port in m_tag
|
|
* IP_FW_TEE tee packet, port in m_tag
|
|
* IP_FW_DUMMYNET to dummynet, pipe in args->cookie
|
|
* IP_FW_NETGRAPH into netgraph, cookie args->cookie
|
|
* args->rule contains the matching rule,
|
|
* args->rule.info has additional information.
|
|
*
|
|
*/
|
|
int
|
|
ipfw_chk(struct ip_fw_args *args)
|
|
{
|
|
|
|
/*
|
|
* Local variables holding state while processing a packet:
|
|
*
|
|
* IMPORTANT NOTE: to speed up the processing of rules, there
|
|
* are some assumption on the values of the variables, which
|
|
* are documented here. Should you change them, please check
|
|
* the implementation of the various instructions to make sure
|
|
* that they still work.
|
|
*
|
|
* args->eh The MAC header. It is non-null for a layer2
|
|
* packet, it is NULL for a layer-3 packet.
|
|
* **notyet**
|
|
* args->L3offset Offset in the packet to the L3 (IP or equiv.) header.
|
|
*
|
|
* m | args->m Pointer to the mbuf, as received from the caller.
|
|
* It may change if ipfw_chk() does an m_pullup, or if it
|
|
* consumes the packet because it calls send_reject().
|
|
* XXX This has to change, so that ipfw_chk() never modifies
|
|
* or consumes the buffer.
|
|
* ip is the beginning of the ip(4 or 6) header.
|
|
* Calculated by adding the L3offset to the start of data.
|
|
* (Until we start using L3offset, the packet is
|
|
* supposed to start with the ip header).
|
|
*/
|
|
struct mbuf *m = args->m;
|
|
struct ip *ip = mtod(m, struct ip *);
|
|
|
|
/*
|
|
* For rules which contain uid/gid or jail constraints, cache
|
|
* a copy of the users credentials after the pcb lookup has been
|
|
* executed. This will speed up the processing of rules with
|
|
* these types of constraints, as well as decrease contention
|
|
* on pcb related locks.
|
|
*/
|
|
#ifndef __FreeBSD__
|
|
struct bsd_ucred ucred_cache;
|
|
#else
|
|
struct ucred *ucred_cache = NULL;
|
|
#endif
|
|
int ucred_lookup = 0;
|
|
|
|
/*
|
|
* oif | args->oif If NULL, ipfw_chk has been called on the
|
|
* inbound path (ether_input, ip_input).
|
|
* If non-NULL, ipfw_chk has been called on the outbound path
|
|
* (ether_output, ip_output).
|
|
*/
|
|
struct ifnet *oif = args->oif;
|
|
|
|
int f_pos = 0; /* index of current rule in the array */
|
|
int retval = 0;
|
|
|
|
/*
|
|
* hlen The length of the IP header.
|
|
*/
|
|
u_int hlen = 0; /* hlen >0 means we have an IP pkt */
|
|
|
|
/*
|
|
* offset The offset of a fragment. offset != 0 means that
|
|
* we have a fragment at this offset of an IPv4 packet.
|
|
* offset == 0 means that (if this is an IPv4 packet)
|
|
* this is the first or only fragment.
|
|
* For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header
|
|
* or there is a single packet fragement (fragement header added
|
|
* without needed). We will treat a single packet fragment as if
|
|
* there was no fragment header (or log/block depending on the
|
|
* V_fw_permit_single_frag6 sysctl setting).
|
|
*/
|
|
u_short offset = 0;
|
|
u_short ip6f_mf = 0;
|
|
|
|
/*
|
|
* Local copies of addresses. They are only valid if we have
|
|
* an IP packet.
|
|
*
|
|
* proto The protocol. Set to 0 for non-ip packets,
|
|
* or to the protocol read from the packet otherwise.
|
|
* proto != 0 means that we have an IPv4 packet.
|
|
*
|
|
* src_port, dst_port port numbers, in HOST format. Only
|
|
* valid for TCP and UDP packets.
|
|
*
|
|
* src_ip, dst_ip ip addresses, in NETWORK format.
|
|
* Only valid for IPv4 packets.
|
|
*/
|
|
uint8_t proto;
|
|
uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */
|
|
struct in_addr src_ip, dst_ip; /* NOTE: network format */
|
|
uint16_t iplen=0;
|
|
int pktlen;
|
|
uint16_t etype = 0; /* Host order stored ether type */
|
|
|
|
/*
|
|
* dyn_dir = MATCH_UNKNOWN when rules unchecked,
|
|
* MATCH_NONE when checked and not matched (q = NULL),
|
|
* MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL)
|
|
*/
|
|
int dyn_dir = MATCH_UNKNOWN;
|
|
ipfw_dyn_rule *q = NULL;
|
|
struct ip_fw_chain *chain = &V_layer3_chain;
|
|
|
|
/*
|
|
* We store in ulp a pointer to the upper layer protocol header.
|
|
* In the ipv4 case this is easy to determine from the header,
|
|
* but for ipv6 we might have some additional headers in the middle.
|
|
* ulp is NULL if not found.
|
|
*/
|
|
void *ulp = NULL; /* upper layer protocol pointer. */
|
|
|
|
/* XXX ipv6 variables */
|
|
int is_ipv6 = 0;
|
|
uint8_t icmp6_type = 0;
|
|
uint16_t ext_hd = 0; /* bits vector for extension header filtering */
|
|
/* end of ipv6 variables */
|
|
|
|
int is_ipv4 = 0;
|
|
|
|
int done = 0; /* flag to exit the outer loop */
|
|
|
|
if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready))
|
|
return (IP_FW_PASS); /* accept */
|
|
|
|
dst_ip.s_addr = 0; /* make sure it is initialized */
|
|
src_ip.s_addr = 0; /* make sure it is initialized */
|
|
pktlen = m->m_pkthdr.len;
|
|
args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */
|
|
proto = args->f_id.proto = 0; /* mark f_id invalid */
|
|
/* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */
|
|
|
|
/*
|
|
* PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous,
|
|
* then it sets p to point at the offset "len" in the mbuf. WARNING: the
|
|
* pointer might become stale after other pullups (but we never use it
|
|
* this way).
|
|
*/
|
|
#define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T))
|
|
#define PULLUP_LEN(_len, p, T) \
|
|
do { \
|
|
int x = (_len) + T; \
|
|
if ((m)->m_len < x) { \
|
|
args->m = m = m_pullup(m, x); \
|
|
if (m == NULL) \
|
|
goto pullup_failed; \
|
|
} \
|
|
p = (mtod(m, char *) + (_len)); \
|
|
} while (0)
|
|
|
|
/*
|
|
* if we have an ether header,
|
|
*/
|
|
if (args->eh)
|
|
etype = ntohs(args->eh->ether_type);
|
|
|
|
/* Identify IP packets and fill up variables. */
|
|
if (pktlen >= sizeof(struct ip6_hdr) &&
|
|
(args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) {
|
|
struct ip6_hdr *ip6 = (struct ip6_hdr *)ip;
|
|
is_ipv6 = 1;
|
|
args->f_id.addr_type = 6;
|
|
hlen = sizeof(struct ip6_hdr);
|
|
proto = ip6->ip6_nxt;
|
|
|
|
/* Search extension headers to find upper layer protocols */
|
|
while (ulp == NULL && offset == 0) {
|
|
switch (proto) {
|
|
case IPPROTO_ICMPV6:
|
|
PULLUP_TO(hlen, ulp, struct icmp6_hdr);
|
|
icmp6_type = ICMP6(ulp)->icmp6_type;
|
|
break;
|
|
|
|
case IPPROTO_TCP:
|
|
PULLUP_TO(hlen, ulp, struct tcphdr);
|
|
dst_port = TCP(ulp)->th_dport;
|
|
src_port = TCP(ulp)->th_sport;
|
|
/* save flags for dynamic rules */
|
|
args->f_id._flags = TCP(ulp)->th_flags;
|
|
break;
|
|
|
|
case IPPROTO_SCTP:
|
|
PULLUP_TO(hlen, ulp, struct sctphdr);
|
|
src_port = SCTP(ulp)->src_port;
|
|
dst_port = SCTP(ulp)->dest_port;
|
|
break;
|
|
|
|
case IPPROTO_UDP:
|
|
PULLUP_TO(hlen, ulp, struct udphdr);
|
|
dst_port = UDP(ulp)->uh_dport;
|
|
src_port = UDP(ulp)->uh_sport;
|
|
break;
|
|
|
|
case IPPROTO_HOPOPTS: /* RFC 2460 */
|
|
PULLUP_TO(hlen, ulp, struct ip6_hbh);
|
|
ext_hd |= EXT_HOPOPTS;
|
|
hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
|
|
proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
|
|
ulp = NULL;
|
|
break;
|
|
|
|
case IPPROTO_ROUTING: /* RFC 2460 */
|
|
PULLUP_TO(hlen, ulp, struct ip6_rthdr);
|
|
switch (((struct ip6_rthdr *)ulp)->ip6r_type) {
|
|
case 0:
|
|
ext_hd |= EXT_RTHDR0;
|
|
break;
|
|
case 2:
|
|
ext_hd |= EXT_RTHDR2;
|
|
break;
|
|
default:
|
|
if (V_fw_verbose)
|
|
printf("IPFW2: IPV6 - Unknown "
|
|
"Routing Header type(%d)\n",
|
|
((struct ip6_rthdr *)
|
|
ulp)->ip6r_type);
|
|
if (V_fw_deny_unknown_exthdrs)
|
|
return (IP_FW_DENY);
|
|
break;
|
|
}
|
|
ext_hd |= EXT_ROUTING;
|
|
hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3;
|
|
proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt;
|
|
ulp = NULL;
|
|
break;
|
|
|
|
case IPPROTO_FRAGMENT: /* RFC 2460 */
|
|
PULLUP_TO(hlen, ulp, struct ip6_frag);
|
|
ext_hd |= EXT_FRAGMENT;
|
|
hlen += sizeof (struct ip6_frag);
|
|
proto = ((struct ip6_frag *)ulp)->ip6f_nxt;
|
|
offset = ((struct ip6_frag *)ulp)->ip6f_offlg &
|
|
IP6F_OFF_MASK;
|
|
ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg &
|
|
IP6F_MORE_FRAG;
|
|
if (V_fw_permit_single_frag6 == 0 &&
|
|
offset == 0 && ip6f_mf == 0) {
|
|
if (V_fw_verbose)
|
|
printf("IPFW2: IPV6 - Invalid "
|
|
"Fragment Header\n");
|
|
if (V_fw_deny_unknown_exthdrs)
|
|
return (IP_FW_DENY);
|
|
break;
|
|
}
|
|
args->f_id.extra =
|
|
ntohl(((struct ip6_frag *)ulp)->ip6f_ident);
|
|
ulp = NULL;
|
|
break;
|
|
|
|
case IPPROTO_DSTOPTS: /* RFC 2460 */
|
|
PULLUP_TO(hlen, ulp, struct ip6_hbh);
|
|
ext_hd |= EXT_DSTOPTS;
|
|
hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
|
|
proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
|
|
ulp = NULL;
|
|
break;
|
|
|
|
case IPPROTO_AH: /* RFC 2402 */
|
|
PULLUP_TO(hlen, ulp, struct ip6_ext);
|
|
ext_hd |= EXT_AH;
|
|
hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2;
|
|
proto = ((struct ip6_ext *)ulp)->ip6e_nxt;
|
|
ulp = NULL;
|
|
break;
|
|
|
|
case IPPROTO_ESP: /* RFC 2406 */
|
|
PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */
|
|
/* Anything past Seq# is variable length and
|
|
* data past this ext. header is encrypted. */
|
|
ext_hd |= EXT_ESP;
|
|
break;
|
|
|
|
case IPPROTO_NONE: /* RFC 2460 */
|
|
/*
|
|
* Packet ends here, and IPv6 header has
|
|
* already been pulled up. If ip6e_len!=0
|
|
* then octets must be ignored.
|
|
*/
|
|
ulp = ip; /* non-NULL to get out of loop. */
|
|
break;
|
|
|
|
case IPPROTO_OSPFIGP:
|
|
/* XXX OSPF header check? */
|
|
PULLUP_TO(hlen, ulp, struct ip6_ext);
|
|
break;
|
|
|
|
case IPPROTO_PIM:
|
|
/* XXX PIM header check? */
|
|
PULLUP_TO(hlen, ulp, struct pim);
|
|
break;
|
|
|
|
case IPPROTO_CARP:
|
|
PULLUP_TO(hlen, ulp, struct carp_header);
|
|
if (((struct carp_header *)ulp)->carp_version !=
|
|
CARP_VERSION)
|
|
return (IP_FW_DENY);
|
|
if (((struct carp_header *)ulp)->carp_type !=
|
|
CARP_ADVERTISEMENT)
|
|
return (IP_FW_DENY);
|
|
break;
|
|
|
|
case IPPROTO_IPV6: /* RFC 2893 */
|
|
PULLUP_TO(hlen, ulp, struct ip6_hdr);
|
|
break;
|
|
|
|
case IPPROTO_IPV4: /* RFC 2893 */
|
|
PULLUP_TO(hlen, ulp, struct ip);
|
|
break;
|
|
|
|
default:
|
|
if (V_fw_verbose)
|
|
printf("IPFW2: IPV6 - Unknown "
|
|
"Extension Header(%d), ext_hd=%x\n",
|
|
proto, ext_hd);
|
|
if (V_fw_deny_unknown_exthdrs)
|
|
return (IP_FW_DENY);
|
|
PULLUP_TO(hlen, ulp, struct ip6_ext);
|
|
break;
|
|
} /*switch */
|
|
}
|
|
ip = mtod(m, struct ip *);
|
|
ip6 = (struct ip6_hdr *)ip;
|
|
args->f_id.src_ip6 = ip6->ip6_src;
|
|
args->f_id.dst_ip6 = ip6->ip6_dst;
|
|
args->f_id.src_ip = 0;
|
|
args->f_id.dst_ip = 0;
|
|
args->f_id.flow_id6 = ntohl(ip6->ip6_flow);
|
|
} else if (pktlen >= sizeof(struct ip) &&
|
|
(args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) {
|
|
is_ipv4 = 1;
|
|
hlen = ip->ip_hl << 2;
|
|
args->f_id.addr_type = 4;
|
|
|
|
/*
|
|
* Collect parameters into local variables for faster matching.
|
|
*/
|
|
proto = ip->ip_p;
|
|
src_ip = ip->ip_src;
|
|
dst_ip = ip->ip_dst;
|
|
offset = ntohs(ip->ip_off) & IP_OFFMASK;
|
|
iplen = ntohs(ip->ip_len);
|
|
pktlen = iplen < pktlen ? iplen : pktlen;
|
|
|
|
if (offset == 0) {
|
|
switch (proto) {
|
|
case IPPROTO_TCP:
|
|
PULLUP_TO(hlen, ulp, struct tcphdr);
|
|
dst_port = TCP(ulp)->th_dport;
|
|
src_port = TCP(ulp)->th_sport;
|
|
/* save flags for dynamic rules */
|
|
args->f_id._flags = TCP(ulp)->th_flags;
|
|
break;
|
|
|
|
case IPPROTO_SCTP:
|
|
PULLUP_TO(hlen, ulp, struct sctphdr);
|
|
src_port = SCTP(ulp)->src_port;
|
|
dst_port = SCTP(ulp)->dest_port;
|
|
break;
|
|
|
|
case IPPROTO_UDP:
|
|
PULLUP_TO(hlen, ulp, struct udphdr);
|
|
dst_port = UDP(ulp)->uh_dport;
|
|
src_port = UDP(ulp)->uh_sport;
|
|
break;
|
|
|
|
case IPPROTO_ICMP:
|
|
PULLUP_TO(hlen, ulp, struct icmphdr);
|
|
//args->f_id.flags = ICMP(ulp)->icmp_type;
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
ip = mtod(m, struct ip *);
|
|
args->f_id.src_ip = ntohl(src_ip.s_addr);
|
|
args->f_id.dst_ip = ntohl(dst_ip.s_addr);
|
|
}
|
|
#undef PULLUP_TO
|
|
if (proto) { /* we may have port numbers, store them */
|
|
args->f_id.proto = proto;
|
|
args->f_id.src_port = src_port = ntohs(src_port);
|
|
args->f_id.dst_port = dst_port = ntohs(dst_port);
|
|
}
|
|
|
|
IPFW_RLOCK(chain);
|
|
if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */
|
|
IPFW_RUNLOCK(chain);
|
|
return (IP_FW_PASS); /* accept */
|
|
}
|
|
if (args->rule.slot) {
|
|
/*
|
|
* Packet has already been tagged as a result of a previous
|
|
* match on rule args->rule aka args->rule_id (PIPE, QUEUE,
|
|
* REASS, NETGRAPH, DIVERT/TEE...)
|
|
* Validate the slot and continue from the next one
|
|
* if still present, otherwise do a lookup.
|
|
*/
|
|
f_pos = (args->rule.chain_id == chain->id) ?
|
|
args->rule.slot :
|
|
ipfw_find_rule(chain, args->rule.rulenum,
|
|
args->rule.rule_id);
|
|
} else {
|
|
f_pos = 0;
|
|
}
|
|
|
|
/*
|
|
* Now scan the rules, and parse microinstructions for each rule.
|
|
* We have two nested loops and an inner switch. Sometimes we
|
|
* need to break out of one or both loops, or re-enter one of
|
|
* the loops with updated variables. Loop variables are:
|
|
*
|
|
* f_pos (outer loop) points to the current rule.
|
|
* On output it points to the matching rule.
|
|
* done (outer loop) is used as a flag to break the loop.
|
|
* l (inner loop) residual length of current rule.
|
|
* cmd points to the current microinstruction.
|
|
*
|
|
* We break the inner loop by setting l=0 and possibly
|
|
* cmdlen=0 if we don't want to advance cmd.
|
|
* We break the outer loop by setting done=1
|
|
* We can restart the inner loop by setting l>0 and f_pos, f, cmd
|
|
* as needed.
|
|
*/
|
|
for (; f_pos < chain->n_rules; f_pos++) {
|
|
ipfw_insn *cmd;
|
|
uint32_t tablearg = 0;
|
|
int l, cmdlen, skip_or; /* skip rest of OR block */
|
|
struct ip_fw *f;
|
|
|
|
f = chain->map[f_pos];
|
|
if (V_set_disable & (1 << f->set) )
|
|
continue;
|
|
|
|
skip_or = 0;
|
|
for (l = f->cmd_len, cmd = f->cmd ; l > 0 ;
|
|
l -= cmdlen, cmd += cmdlen) {
|
|
int match;
|
|
|
|
/*
|
|
* check_body is a jump target used when we find a
|
|
* CHECK_STATE, and need to jump to the body of
|
|
* the target rule.
|
|
*/
|
|
|
|
/* check_body: */
|
|
cmdlen = F_LEN(cmd);
|
|
/*
|
|
* An OR block (insn_1 || .. || insn_n) has the
|
|
* F_OR bit set in all but the last instruction.
|
|
* The first match will set "skip_or", and cause
|
|
* the following instructions to be skipped until
|
|
* past the one with the F_OR bit clear.
|
|
*/
|
|
if (skip_or) { /* skip this instruction */
|
|
if ((cmd->len & F_OR) == 0)
|
|
skip_or = 0; /* next one is good */
|
|
continue;
|
|
}
|
|
match = 0; /* set to 1 if we succeed */
|
|
|
|
switch (cmd->opcode) {
|
|
/*
|
|
* The first set of opcodes compares the packet's
|
|
* fields with some pattern, setting 'match' if a
|
|
* match is found. At the end of the loop there is
|
|
* logic to deal with F_NOT and F_OR flags associated
|
|
* with the opcode.
|
|
*/
|
|
case O_NOP:
|
|
match = 1;
|
|
break;
|
|
|
|
case O_FORWARD_MAC:
|
|
printf("ipfw: opcode %d unimplemented\n",
|
|
cmd->opcode);
|
|
break;
|
|
|
|
case O_GID:
|
|
case O_UID:
|
|
case O_JAIL:
|
|
/*
|
|
* We only check offset == 0 && proto != 0,
|
|
* as this ensures that we have a
|
|
* packet with the ports info.
|
|
*/
|
|
if (offset != 0)
|
|
break;
|
|
if (proto == IPPROTO_TCP ||
|
|
proto == IPPROTO_UDP)
|
|
match = check_uidgid(
|
|
(ipfw_insn_u32 *)cmd,
|
|
args, &ucred_lookup,
|
|
#ifdef __FreeBSD__
|
|
&ucred_cache);
|
|
#else
|
|
(void *)&ucred_cache);
|
|
#endif
|
|
break;
|
|
|
|
case O_RECV:
|
|
match = iface_match(m->m_pkthdr.rcvif,
|
|
(ipfw_insn_if *)cmd, chain, &tablearg);
|
|
break;
|
|
|
|
case O_XMIT:
|
|
match = iface_match(oif, (ipfw_insn_if *)cmd,
|
|
chain, &tablearg);
|
|
break;
|
|
|
|
case O_VIA:
|
|
match = iface_match(oif ? oif :
|
|
m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd,
|
|
chain, &tablearg);
|
|
break;
|
|
|
|
case O_MACADDR2:
|
|
if (args->eh != NULL) { /* have MAC header */
|
|
u_int32_t *want = (u_int32_t *)
|
|
((ipfw_insn_mac *)cmd)->addr;
|
|
u_int32_t *mask = (u_int32_t *)
|
|
((ipfw_insn_mac *)cmd)->mask;
|
|
u_int32_t *hdr = (u_int32_t *)args->eh;
|
|
|
|
match =
|
|
( want[0] == (hdr[0] & mask[0]) &&
|
|
want[1] == (hdr[1] & mask[1]) &&
|
|
want[2] == (hdr[2] & mask[2]) );
|
|
}
|
|
break;
|
|
|
|
case O_MAC_TYPE:
|
|
if (args->eh != NULL) {
|
|
u_int16_t *p =
|
|
((ipfw_insn_u16 *)cmd)->ports;
|
|
int i;
|
|
|
|
for (i = cmdlen - 1; !match && i>0;
|
|
i--, p += 2)
|
|
match = (etype >= p[0] &&
|
|
etype <= p[1]);
|
|
}
|
|
break;
|
|
|
|
case O_FRAG:
|
|
match = (offset != 0);
|
|
break;
|
|
|
|
case O_IN: /* "out" is "not in" */
|
|
match = (oif == NULL);
|
|
break;
|
|
|
|
case O_LAYER2:
|
|
match = (args->eh != NULL);
|
|
break;
|
|
|
|
case O_DIVERTED:
|
|
{
|
|
/* For diverted packets, args->rule.info
|
|
* contains the divert port (in host format)
|
|
* reason and direction.
|
|
*/
|
|
uint32_t i = args->rule.info;
|
|
match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT &&
|
|
cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2);
|
|
}
|
|
break;
|
|
|
|
case O_PROTO:
|
|
/*
|
|
* We do not allow an arg of 0 so the
|
|
* check of "proto" only suffices.
|
|
*/
|
|
match = (proto == cmd->arg1);
|
|
break;
|
|
|
|
case O_IP_SRC:
|
|
match = is_ipv4 &&
|
|
(((ipfw_insn_ip *)cmd)->addr.s_addr ==
|
|
src_ip.s_addr);
|
|
break;
|
|
|
|
case O_IP_SRC_LOOKUP:
|
|
case O_IP_DST_LOOKUP:
|
|
if (is_ipv4) {
|
|
uint32_t key =
|
|
(cmd->opcode == O_IP_DST_LOOKUP) ?
|
|
dst_ip.s_addr : src_ip.s_addr;
|
|
uint32_t v = 0;
|
|
|
|
if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) {
|
|
/* generic lookup. The key must be
|
|
* in 32bit big-endian format.
|
|
*/
|
|
v = ((ipfw_insn_u32 *)cmd)->d[1];
|
|
if (v == 0)
|
|
key = dst_ip.s_addr;
|
|
else if (v == 1)
|
|
key = src_ip.s_addr;
|
|
else if (v == 6) /* dscp */
|
|
key = (ip->ip_tos >> 2) & 0x3f;
|
|
else if (offset != 0)
|
|
break;
|
|
else if (proto != IPPROTO_TCP &&
|
|
proto != IPPROTO_UDP)
|
|
break;
|
|
else if (v == 2)
|
|
key = htonl(dst_port);
|
|
else if (v == 3)
|
|
key = htonl(src_port);
|
|
else if (v == 4 || v == 5) {
|
|
check_uidgid(
|
|
(ipfw_insn_u32 *)cmd,
|
|
args, &ucred_lookup,
|
|
#ifdef __FreeBSD__
|
|
&ucred_cache);
|
|
if (v == 4 /* O_UID */)
|
|
key = ucred_cache->cr_uid;
|
|
else if (v == 5 /* O_JAIL */)
|
|
key = ucred_cache->cr_prison->pr_id;
|
|
#else /* !__FreeBSD__ */
|
|
(void *)&ucred_cache);
|
|
if (v ==4 /* O_UID */)
|
|
key = ucred_cache.uid;
|
|
else if (v == 5 /* O_JAIL */)
|
|
key = ucred_cache.xid;
|
|
#endif /* !__FreeBSD__ */
|
|
key = htonl(key);
|
|
} else
|
|
break;
|
|
}
|
|
match = ipfw_lookup_table(chain,
|
|
cmd->arg1, key, &v);
|
|
if (!match)
|
|
break;
|
|
if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
|
|
match =
|
|
((ipfw_insn_u32 *)cmd)->d[0] == v;
|
|
else
|
|
tablearg = v;
|
|
} else if (is_ipv6) {
|
|
uint32_t v = 0;
|
|
void *pkey = (cmd->opcode == O_IP_DST_LOOKUP) ?
|
|
&args->f_id.dst_ip6: &args->f_id.src_ip6;
|
|
match = ipfw_lookup_table_extended(chain,
|
|
cmd->arg1, pkey, &v,
|
|
IPFW_TABLE_CIDR);
|
|
if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
|
|
match = ((ipfw_insn_u32 *)cmd)->d[0] == v;
|
|
if (match)
|
|
tablearg = v;
|
|
}
|
|
break;
|
|
|
|
case O_IP_SRC_MASK:
|
|
case O_IP_DST_MASK:
|
|
if (is_ipv4) {
|
|
uint32_t a =
|
|
(cmd->opcode == O_IP_DST_MASK) ?
|
|
dst_ip.s_addr : src_ip.s_addr;
|
|
uint32_t *p = ((ipfw_insn_u32 *)cmd)->d;
|
|
int i = cmdlen-1;
|
|
|
|
for (; !match && i>0; i-= 2, p+= 2)
|
|
match = (p[0] == (a & p[1]));
|
|
}
|
|
break;
|
|
|
|
case O_IP_SRC_ME:
|
|
if (is_ipv4) {
|
|
struct ifnet *tif;
|
|
|
|
INADDR_TO_IFP(src_ip, tif);
|
|
match = (tif != NULL);
|
|
break;
|
|
}
|
|
#ifdef INET6
|
|
/* FALLTHROUGH */
|
|
case O_IP6_SRC_ME:
|
|
match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6);
|
|
#endif
|
|
break;
|
|
|
|
case O_IP_DST_SET:
|
|
case O_IP_SRC_SET:
|
|
if (is_ipv4) {
|
|
u_int32_t *d = (u_int32_t *)(cmd+1);
|
|
u_int32_t addr =
|
|
cmd->opcode == O_IP_DST_SET ?
|
|
args->f_id.dst_ip :
|
|
args->f_id.src_ip;
|
|
|
|
if (addr < d[0])
|
|
break;
|
|
addr -= d[0]; /* subtract base */
|
|
match = (addr < cmd->arg1) &&
|
|
( d[ 1 + (addr>>5)] &
|
|
(1<<(addr & 0x1f)) );
|
|
}
|
|
break;
|
|
|
|
case O_IP_DST:
|
|
match = is_ipv4 &&
|
|
(((ipfw_insn_ip *)cmd)->addr.s_addr ==
|
|
dst_ip.s_addr);
|
|
break;
|
|
|
|
case O_IP_DST_ME:
|
|
if (is_ipv4) {
|
|
struct ifnet *tif;
|
|
|
|
INADDR_TO_IFP(dst_ip, tif);
|
|
match = (tif != NULL);
|
|
break;
|
|
}
|
|
#ifdef INET6
|
|
/* FALLTHROUGH */
|
|
case O_IP6_DST_ME:
|
|
match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6);
|
|
#endif
|
|
break;
|
|
|
|
|
|
case O_IP_SRCPORT:
|
|
case O_IP_DSTPORT:
|
|
/*
|
|
* offset == 0 && proto != 0 is enough
|
|
* to guarantee that we have a
|
|
* packet with port info.
|
|
*/
|
|
if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP)
|
|
&& offset == 0) {
|
|
u_int16_t x =
|
|
(cmd->opcode == O_IP_SRCPORT) ?
|
|
src_port : dst_port ;
|
|
u_int16_t *p =
|
|
((ipfw_insn_u16 *)cmd)->ports;
|
|
int i;
|
|
|
|
for (i = cmdlen - 1; !match && i>0;
|
|
i--, p += 2)
|
|
match = (x>=p[0] && x<=p[1]);
|
|
}
|
|
break;
|
|
|
|
case O_ICMPTYPE:
|
|
match = (offset == 0 && proto==IPPROTO_ICMP &&
|
|
icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) );
|
|
break;
|
|
|
|
#ifdef INET6
|
|
case O_ICMP6TYPE:
|
|
match = is_ipv6 && offset == 0 &&
|
|
proto==IPPROTO_ICMPV6 &&
|
|
icmp6type_match(
|
|
ICMP6(ulp)->icmp6_type,
|
|
(ipfw_insn_u32 *)cmd);
|
|
break;
|
|
#endif /* INET6 */
|
|
|
|
case O_IPOPT:
|
|
match = (is_ipv4 &&
|
|
ipopts_match(ip, cmd) );
|
|
break;
|
|
|
|
case O_IPVER:
|
|
match = (is_ipv4 &&
|
|
cmd->arg1 == ip->ip_v);
|
|
break;
|
|
|
|
case O_IPID:
|
|
case O_IPLEN:
|
|
case O_IPTTL:
|
|
if (is_ipv4) { /* only for IP packets */
|
|
uint16_t x;
|
|
uint16_t *p;
|
|
int i;
|
|
|
|
if (cmd->opcode == O_IPLEN)
|
|
x = iplen;
|
|
else if (cmd->opcode == O_IPTTL)
|
|
x = ip->ip_ttl;
|
|
else /* must be IPID */
|
|
x = ntohs(ip->ip_id);
|
|
if (cmdlen == 1) {
|
|
match = (cmd->arg1 == x);
|
|
break;
|
|
}
|
|
/* otherwise we have ranges */
|
|
p = ((ipfw_insn_u16 *)cmd)->ports;
|
|
i = cmdlen - 1;
|
|
for (; !match && i>0; i--, p += 2)
|
|
match = (x >= p[0] && x <= p[1]);
|
|
}
|
|
break;
|
|
|
|
case O_IPPRECEDENCE:
|
|
match = (is_ipv4 &&
|
|
(cmd->arg1 == (ip->ip_tos & 0xe0)) );
|
|
break;
|
|
|
|
case O_IPTOS:
|
|
match = (is_ipv4 &&
|
|
flags_match(cmd, ip->ip_tos));
|
|
break;
|
|
|
|
case O_TCPDATALEN:
|
|
if (proto == IPPROTO_TCP && offset == 0) {
|
|
struct tcphdr *tcp;
|
|
uint16_t x;
|
|
uint16_t *p;
|
|
int i;
|
|
|
|
tcp = TCP(ulp);
|
|
x = iplen -
|
|
((ip->ip_hl + tcp->th_off) << 2);
|
|
if (cmdlen == 1) {
|
|
match = (cmd->arg1 == x);
|
|
break;
|
|
}
|
|
/* otherwise we have ranges */
|
|
p = ((ipfw_insn_u16 *)cmd)->ports;
|
|
i = cmdlen - 1;
|
|
for (; !match && i>0; i--, p += 2)
|
|
match = (x >= p[0] && x <= p[1]);
|
|
}
|
|
break;
|
|
|
|
case O_TCPFLAGS:
|
|
match = (proto == IPPROTO_TCP && offset == 0 &&
|
|
flags_match(cmd, TCP(ulp)->th_flags));
|
|
break;
|
|
|
|
case O_TCPOPTS:
|
|
PULLUP_LEN(hlen, ulp, (TCP(ulp)->th_off << 2));
|
|
match = (proto == IPPROTO_TCP && offset == 0 &&
|
|
tcpopts_match(TCP(ulp), cmd));
|
|
break;
|
|
|
|
case O_TCPSEQ:
|
|
match = (proto == IPPROTO_TCP && offset == 0 &&
|
|
((ipfw_insn_u32 *)cmd)->d[0] ==
|
|
TCP(ulp)->th_seq);
|
|
break;
|
|
|
|
case O_TCPACK:
|
|
match = (proto == IPPROTO_TCP && offset == 0 &&
|
|
((ipfw_insn_u32 *)cmd)->d[0] ==
|
|
TCP(ulp)->th_ack);
|
|
break;
|
|
|
|
case O_TCPWIN:
|
|
if (proto == IPPROTO_TCP && offset == 0) {
|
|
uint16_t x;
|
|
uint16_t *p;
|
|
int i;
|
|
|
|
x = ntohs(TCP(ulp)->th_win);
|
|
if (cmdlen == 1) {
|
|
match = (cmd->arg1 == x);
|
|
break;
|
|
}
|
|
/* Otherwise we have ranges. */
|
|
p = ((ipfw_insn_u16 *)cmd)->ports;
|
|
i = cmdlen - 1;
|
|
for (; !match && i > 0; i--, p += 2)
|
|
match = (x >= p[0] && x <= p[1]);
|
|
}
|
|
break;
|
|
|
|
case O_ESTAB:
|
|
/* reject packets which have SYN only */
|
|
/* XXX should i also check for TH_ACK ? */
|
|
match = (proto == IPPROTO_TCP && offset == 0 &&
|
|
(TCP(ulp)->th_flags &
|
|
(TH_RST | TH_ACK | TH_SYN)) != TH_SYN);
|
|
break;
|
|
|
|
case O_ALTQ: {
|
|
struct pf_mtag *at;
|
|
struct m_tag *mtag;
|
|
ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd;
|
|
|
|
/*
|
|
* ALTQ uses mbuf tags from another
|
|
* packet filtering system - pf(4).
|
|
* We allocate a tag in its format
|
|
* and fill it in, pretending to be pf(4).
|
|
*/
|
|
match = 1;
|
|
at = pf_find_mtag(m);
|
|
if (at != NULL && at->qid != 0)
|
|
break;
|
|
mtag = m_tag_get(PACKET_TAG_PF,
|
|
sizeof(struct pf_mtag), M_NOWAIT | M_ZERO);
|
|
if (mtag == NULL) {
|
|
/*
|
|
* Let the packet fall back to the
|
|
* default ALTQ.
|
|
*/
|
|
break;
|
|
}
|
|
m_tag_prepend(m, mtag);
|
|
at = (struct pf_mtag *)(mtag + 1);
|
|
at->qid = altq->qid;
|
|
at->hdr = ip;
|
|
break;
|
|
}
|
|
|
|
case O_LOG:
|
|
ipfw_log(f, hlen, args, m,
|
|
oif, offset | ip6f_mf, tablearg, ip);
|
|
match = 1;
|
|
break;
|
|
|
|
case O_PROB:
|
|
match = (random()<((ipfw_insn_u32 *)cmd)->d[0]);
|
|
break;
|
|
|
|
case O_VERREVPATH:
|
|
/* Outgoing packets automatically pass/match */
|
|
match = ((oif != NULL) ||
|
|
(m->m_pkthdr.rcvif == NULL) ||
|
|
(
|
|
#ifdef INET6
|
|
is_ipv6 ?
|
|
verify_path6(&(args->f_id.src_ip6),
|
|
m->m_pkthdr.rcvif, args->f_id.fib) :
|
|
#endif
|
|
verify_path(src_ip, m->m_pkthdr.rcvif,
|
|
args->f_id.fib)));
|
|
break;
|
|
|
|
case O_VERSRCREACH:
|
|
/* Outgoing packets automatically pass/match */
|
|
match = (hlen > 0 && ((oif != NULL) ||
|
|
#ifdef INET6
|
|
is_ipv6 ?
|
|
verify_path6(&(args->f_id.src_ip6),
|
|
NULL, args->f_id.fib) :
|
|
#endif
|
|
verify_path(src_ip, NULL, args->f_id.fib)));
|
|
break;
|
|
|
|
case O_ANTISPOOF:
|
|
/* Outgoing packets automatically pass/match */
|
|
if (oif == NULL && hlen > 0 &&
|
|
( (is_ipv4 && in_localaddr(src_ip))
|
|
#ifdef INET6
|
|
|| (is_ipv6 &&
|
|
in6_localaddr(&(args->f_id.src_ip6)))
|
|
#endif
|
|
))
|
|
match =
|
|
#ifdef INET6
|
|
is_ipv6 ? verify_path6(
|
|
&(args->f_id.src_ip6),
|
|
m->m_pkthdr.rcvif,
|
|
args->f_id.fib) :
|
|
#endif
|
|
verify_path(src_ip,
|
|
m->m_pkthdr.rcvif,
|
|
args->f_id.fib);
|
|
else
|
|
match = 1;
|
|
break;
|
|
|
|
case O_IPSEC:
|
|
#ifdef IPSEC
|
|
match = (m_tag_find(m,
|
|
PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL);
|
|
#endif
|
|
/* otherwise no match */
|
|
break;
|
|
|
|
#ifdef INET6
|
|
case O_IP6_SRC:
|
|
match = is_ipv6 &&
|
|
IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6,
|
|
&((ipfw_insn_ip6 *)cmd)->addr6);
|
|
break;
|
|
|
|
case O_IP6_DST:
|
|
match = is_ipv6 &&
|
|
IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6,
|
|
&((ipfw_insn_ip6 *)cmd)->addr6);
|
|
break;
|
|
case O_IP6_SRC_MASK:
|
|
case O_IP6_DST_MASK:
|
|
if (is_ipv6) {
|
|
int i = cmdlen - 1;
|
|
struct in6_addr p;
|
|
struct in6_addr *d =
|
|
&((ipfw_insn_ip6 *)cmd)->addr6;
|
|
|
|
for (; !match && i > 0; d += 2,
|
|
i -= F_INSN_SIZE(struct in6_addr)
|
|
* 2) {
|
|
p = (cmd->opcode ==
|
|
O_IP6_SRC_MASK) ?
|
|
args->f_id.src_ip6:
|
|
args->f_id.dst_ip6;
|
|
APPLY_MASK(&p, &d[1]);
|
|
match =
|
|
IN6_ARE_ADDR_EQUAL(&d[0],
|
|
&p);
|
|
}
|
|
}
|
|
break;
|
|
|
|
case O_FLOW6ID:
|
|
match = is_ipv6 &&
|
|
flow6id_match(args->f_id.flow_id6,
|
|
(ipfw_insn_u32 *) cmd);
|
|
break;
|
|
|
|
case O_EXT_HDR:
|
|
match = is_ipv6 &&
|
|
(ext_hd & ((ipfw_insn *) cmd)->arg1);
|
|
break;
|
|
|
|
case O_IP6:
|
|
match = is_ipv6;
|
|
break;
|
|
#endif
|
|
|
|
case O_IP4:
|
|
match = is_ipv4;
|
|
break;
|
|
|
|
case O_TAG: {
|
|
struct m_tag *mtag;
|
|
uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ?
|
|
tablearg : cmd->arg1;
|
|
|
|
/* Packet is already tagged with this tag? */
|
|
mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL);
|
|
|
|
/* We have `untag' action when F_NOT flag is
|
|
* present. And we must remove this mtag from
|
|
* mbuf and reset `match' to zero (`match' will
|
|
* be inversed later).
|
|
* Otherwise we should allocate new mtag and
|
|
* push it into mbuf.
|
|
*/
|
|
if (cmd->len & F_NOT) { /* `untag' action */
|
|
if (mtag != NULL)
|
|
m_tag_delete(m, mtag);
|
|
match = 0;
|
|
} else {
|
|
if (mtag == NULL) {
|
|
mtag = m_tag_alloc( MTAG_IPFW,
|
|
tag, 0, M_NOWAIT);
|
|
if (mtag != NULL)
|
|
m_tag_prepend(m, mtag);
|
|
}
|
|
match = 1;
|
|
}
|
|
break;
|
|
}
|
|
|
|
case O_FIB: /* try match the specified fib */
|
|
if (args->f_id.fib == cmd->arg1)
|
|
match = 1;
|
|
break;
|
|
|
|
case O_SOCKARG: {
|
|
struct inpcb *inp = args->inp;
|
|
struct inpcbinfo *pi;
|
|
|
|
if (is_ipv6) /* XXX can we remove this ? */
|
|
break;
|
|
|
|
if (proto == IPPROTO_TCP)
|
|
pi = &V_tcbinfo;
|
|
else if (proto == IPPROTO_UDP)
|
|
pi = &V_udbinfo;
|
|
else
|
|
break;
|
|
|
|
/*
|
|
* XXXRW: so_user_cookie should almost
|
|
* certainly be inp_user_cookie?
|
|
*/
|
|
|
|
/* For incomming packet, lookup up the
|
|
inpcb using the src/dest ip/port tuple */
|
|
if (inp == NULL) {
|
|
inp = in_pcblookup(pi,
|
|
src_ip, htons(src_port),
|
|
dst_ip, htons(dst_port),
|
|
INPLOOKUP_RLOCKPCB, NULL);
|
|
if (inp != NULL) {
|
|
tablearg =
|
|
inp->inp_socket->so_user_cookie;
|
|
if (tablearg)
|
|
match = 1;
|
|
INP_RUNLOCK(inp);
|
|
}
|
|
} else {
|
|
if (inp->inp_socket) {
|
|
tablearg =
|
|
inp->inp_socket->so_user_cookie;
|
|
if (tablearg)
|
|
match = 1;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
case O_TAGGED: {
|
|
struct m_tag *mtag;
|
|
uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ?
|
|
tablearg : cmd->arg1;
|
|
|
|
if (cmdlen == 1) {
|
|
match = m_tag_locate(m, MTAG_IPFW,
|
|
tag, NULL) != NULL;
|
|
break;
|
|
}
|
|
|
|
/* we have ranges */
|
|
for (mtag = m_tag_first(m);
|
|
mtag != NULL && !match;
|
|
mtag = m_tag_next(m, mtag)) {
|
|
uint16_t *p;
|
|
int i;
|
|
|
|
if (mtag->m_tag_cookie != MTAG_IPFW)
|
|
continue;
|
|
|
|
p = ((ipfw_insn_u16 *)cmd)->ports;
|
|
i = cmdlen - 1;
|
|
for(; !match && i > 0; i--, p += 2)
|
|
match =
|
|
mtag->m_tag_id >= p[0] &&
|
|
mtag->m_tag_id <= p[1];
|
|
}
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* The second set of opcodes represents 'actions',
|
|
* i.e. the terminal part of a rule once the packet
|
|
* matches all previous patterns.
|
|
* Typically there is only one action for each rule,
|
|
* and the opcode is stored at the end of the rule
|
|
* (but there are exceptions -- see below).
|
|
*
|
|
* In general, here we set retval and terminate the
|
|
* outer loop (would be a 'break 3' in some language,
|
|
* but we need to set l=0, done=1)
|
|
*
|
|
* Exceptions:
|
|
* O_COUNT and O_SKIPTO actions:
|
|
* instead of terminating, we jump to the next rule
|
|
* (setting l=0), or to the SKIPTO target (setting
|
|
* f/f_len, cmd and l as needed), respectively.
|
|
*
|
|
* O_TAG, O_LOG and O_ALTQ action parameters:
|
|
* perform some action and set match = 1;
|
|
*
|
|
* O_LIMIT and O_KEEP_STATE: these opcodes are
|
|
* not real 'actions', and are stored right
|
|
* before the 'action' part of the rule.
|
|
* These opcodes try to install an entry in the
|
|
* state tables; if successful, we continue with
|
|
* the next opcode (match=1; break;), otherwise
|
|
* the packet must be dropped (set retval,
|
|
* break loops with l=0, done=1)
|
|
*
|
|
* O_PROBE_STATE and O_CHECK_STATE: these opcodes
|
|
* cause a lookup of the state table, and a jump
|
|
* to the 'action' part of the parent rule
|
|
* if an entry is found, or
|
|
* (CHECK_STATE only) a jump to the next rule if
|
|
* the entry is not found.
|
|
* The result of the lookup is cached so that
|
|
* further instances of these opcodes become NOPs.
|
|
* The jump to the next rule is done by setting
|
|
* l=0, cmdlen=0.
|
|
*/
|
|
case O_LIMIT:
|
|
case O_KEEP_STATE:
|
|
if (ipfw_install_state(f,
|
|
(ipfw_insn_limit *)cmd, args, tablearg)) {
|
|
/* error or limit violation */
|
|
retval = IP_FW_DENY;
|
|
l = 0; /* exit inner loop */
|
|
done = 1; /* exit outer loop */
|
|
}
|
|
match = 1;
|
|
break;
|
|
|
|
case O_PROBE_STATE:
|
|
case O_CHECK_STATE:
|
|
/*
|
|
* dynamic rules are checked at the first
|
|
* keep-state or check-state occurrence,
|
|
* with the result being stored in dyn_dir.
|
|
* The compiler introduces a PROBE_STATE
|
|
* instruction for us when we have a
|
|
* KEEP_STATE (because PROBE_STATE needs
|
|
* to be run first).
|
|
*/
|
|
if (dyn_dir == MATCH_UNKNOWN &&
|
|
(q = ipfw_lookup_dyn_rule(&args->f_id,
|
|
&dyn_dir, proto == IPPROTO_TCP ?
|
|
TCP(ulp) : NULL))
|
|
!= NULL) {
|
|
/*
|
|
* Found dynamic entry, update stats
|
|
* and jump to the 'action' part of
|
|
* the parent rule by setting
|
|
* f, cmd, l and clearing cmdlen.
|
|
*/
|
|
q->pcnt++;
|
|
q->bcnt += pktlen;
|
|
/* XXX we would like to have f_pos
|
|
* readily accessible in the dynamic
|
|
* rule, instead of having to
|
|
* lookup q->rule.
|
|
*/
|
|
f = q->rule;
|
|
f_pos = ipfw_find_rule(chain,
|
|
f->rulenum, f->id);
|
|
cmd = ACTION_PTR(f);
|
|
l = f->cmd_len - f->act_ofs;
|
|
ipfw_dyn_unlock();
|
|
cmdlen = 0;
|
|
match = 1;
|
|
break;
|
|
}
|
|
/*
|
|
* Dynamic entry not found. If CHECK_STATE,
|
|
* skip to next rule, if PROBE_STATE just
|
|
* ignore and continue with next opcode.
|
|
*/
|
|
if (cmd->opcode == O_CHECK_STATE)
|
|
l = 0; /* exit inner loop */
|
|
match = 1;
|
|
break;
|
|
|
|
case O_ACCEPT:
|
|
retval = 0; /* accept */
|
|
l = 0; /* exit inner loop */
|
|
done = 1; /* exit outer loop */
|
|
break;
|
|
|
|
case O_PIPE:
|
|
case O_QUEUE:
|
|
set_match(args, f_pos, chain);
|
|
args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ?
|
|
tablearg : cmd->arg1;
|
|
if (cmd->opcode == O_PIPE)
|
|
args->rule.info |= IPFW_IS_PIPE;
|
|
if (V_fw_one_pass)
|
|
args->rule.info |= IPFW_ONEPASS;
|
|
retval = IP_FW_DUMMYNET;
|
|
l = 0; /* exit inner loop */
|
|
done = 1; /* exit outer loop */
|
|
break;
|
|
|
|
case O_DIVERT:
|
|
case O_TEE:
|
|
if (args->eh) /* not on layer 2 */
|
|
break;
|
|
/* otherwise this is terminal */
|
|
l = 0; /* exit inner loop */
|
|
done = 1; /* exit outer loop */
|
|
retval = (cmd->opcode == O_DIVERT) ?
|
|
IP_FW_DIVERT : IP_FW_TEE;
|
|
set_match(args, f_pos, chain);
|
|
args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ?
|
|
tablearg : cmd->arg1;
|
|
break;
|
|
|
|
case O_COUNT:
|
|
f->pcnt++; /* update stats */
|
|
f->bcnt += pktlen;
|
|
f->timestamp = time_uptime;
|
|
l = 0; /* exit inner loop */
|
|
break;
|
|
|
|
case O_SKIPTO:
|
|
f->pcnt++; /* update stats */
|
|
f->bcnt += pktlen;
|
|
f->timestamp = time_uptime;
|
|
/* If possible use cached f_pos (in f->next_rule),
|
|
* whose version is written in f->next_rule
|
|
* (horrible hacks to avoid changing the ABI).
|
|
*/
|
|
if (cmd->arg1 != IP_FW_TABLEARG &&
|
|
(uintptr_t)f->x_next == chain->id) {
|
|
f_pos = (uintptr_t)f->next_rule;
|
|
} else {
|
|
int i = (cmd->arg1 == IP_FW_TABLEARG) ?
|
|
tablearg : cmd->arg1;
|
|
/* make sure we do not jump backward */
|
|
if (i <= f->rulenum)
|
|
i = f->rulenum + 1;
|
|
f_pos = ipfw_find_rule(chain, i, 0);
|
|
/* update the cache */
|
|
if (cmd->arg1 != IP_FW_TABLEARG) {
|
|
f->next_rule =
|
|
(void *)(uintptr_t)f_pos;
|
|
f->x_next =
|
|
(void *)(uintptr_t)chain->id;
|
|
}
|
|
}
|
|
/*
|
|
* Skip disabled rules, and re-enter
|
|
* the inner loop with the correct
|
|
* f_pos, f, l and cmd.
|
|
* Also clear cmdlen and skip_or
|
|
*/
|
|
for (; f_pos < chain->n_rules - 1 &&
|
|
(V_set_disable &
|
|
(1 << chain->map[f_pos]->set));
|
|
f_pos++)
|
|
;
|
|
/* Re-enter the inner loop at the skipto rule. */
|
|
f = chain->map[f_pos];
|
|
l = f->cmd_len;
|
|
cmd = f->cmd;
|
|
match = 1;
|
|
cmdlen = 0;
|
|
skip_or = 0;
|
|
continue;
|
|
break; /* not reached */
|
|
|
|
case O_CALLRETURN: {
|
|
/*
|
|
* Implementation of `subroutine' call/return,
|
|
* in the stack carried in an mbuf tag. This
|
|
* is different from `skipto' in that any call
|
|
* address is possible (`skipto' must prevent
|
|
* backward jumps to avoid endless loops).
|
|
* We have `return' action when F_NOT flag is
|
|
* present. The `m_tag_id' field is used as
|
|
* stack pointer.
|
|
*/
|
|
struct m_tag *mtag;
|
|
uint16_t jmpto, *stack;
|
|
|
|
#define IS_CALL ((cmd->len & F_NOT) == 0)
|
|
#define IS_RETURN ((cmd->len & F_NOT) != 0)
|
|
/*
|
|
* Hand-rolled version of m_tag_locate() with
|
|
* wildcard `type'.
|
|
* If not already tagged, allocate new tag.
|
|
*/
|
|
mtag = m_tag_first(m);
|
|
while (mtag != NULL) {
|
|
if (mtag->m_tag_cookie ==
|
|
MTAG_IPFW_CALL)
|
|
break;
|
|
mtag = m_tag_next(m, mtag);
|
|
}
|
|
if (mtag == NULL && IS_CALL) {
|
|
mtag = m_tag_alloc(MTAG_IPFW_CALL, 0,
|
|
IPFW_CALLSTACK_SIZE *
|
|
sizeof(uint16_t), M_NOWAIT);
|
|
if (mtag != NULL)
|
|
m_tag_prepend(m, mtag);
|
|
}
|
|
|
|
/*
|
|
* On error both `call' and `return' just
|
|
* continue with next rule.
|
|
*/
|
|
if (IS_RETURN && (mtag == NULL ||
|
|
mtag->m_tag_id == 0)) {
|
|
l = 0; /* exit inner loop */
|
|
break;
|
|
}
|
|
if (IS_CALL && (mtag == NULL ||
|
|
mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) {
|
|
printf("ipfw: call stack error, "
|
|
"go to next rule\n");
|
|
l = 0; /* exit inner loop */
|
|
break;
|
|
}
|
|
|
|
f->pcnt++; /* update stats */
|
|
f->bcnt += pktlen;
|
|
f->timestamp = time_uptime;
|
|
stack = (uint16_t *)(mtag + 1);
|
|
|
|
/*
|
|
* The `call' action may use cached f_pos
|
|
* (in f->next_rule), whose version is written
|
|
* in f->next_rule.
|
|
* The `return' action, however, doesn't have
|
|
* fixed jump address in cmd->arg1 and can't use
|
|
* cache.
|
|
*/
|
|
if (IS_CALL) {
|
|
stack[mtag->m_tag_id] = f->rulenum;
|
|
mtag->m_tag_id++;
|
|
if (cmd->arg1 != IP_FW_TABLEARG &&
|
|
(uintptr_t)f->x_next == chain->id) {
|
|
f_pos = (uintptr_t)f->next_rule;
|
|
} else {
|
|
jmpto = (cmd->arg1 ==
|
|
IP_FW_TABLEARG) ? tablearg:
|
|
cmd->arg1;
|
|
f_pos = ipfw_find_rule(chain,
|
|
jmpto, 0);
|
|
/* update the cache */
|
|
if (cmd->arg1 !=
|
|
IP_FW_TABLEARG) {
|
|
f->next_rule =
|
|
(void *)(uintptr_t)
|
|
f_pos;
|
|
f->x_next =
|
|
(void *)(uintptr_t)
|
|
chain->id;
|
|
}
|
|
}
|
|
} else { /* `return' action */
|
|
mtag->m_tag_id--;
|
|
jmpto = stack[mtag->m_tag_id] + 1;
|
|
f_pos = ipfw_find_rule(chain, jmpto, 0);
|
|
}
|
|
|
|
/*
|
|
* Skip disabled rules, and re-enter
|
|
* the inner loop with the correct
|
|
* f_pos, f, l and cmd.
|
|
* Also clear cmdlen and skip_or
|
|
*/
|
|
for (; f_pos < chain->n_rules - 1 &&
|
|
(V_set_disable &
|
|
(1 << chain->map[f_pos]->set)); f_pos++)
|
|
;
|
|
/* Re-enter the inner loop at the dest rule. */
|
|
f = chain->map[f_pos];
|
|
l = f->cmd_len;
|
|
cmd = f->cmd;
|
|
cmdlen = 0;
|
|
skip_or = 0;
|
|
continue;
|
|
break; /* NOTREACHED */
|
|
}
|
|
#undef IS_CALL
|
|
#undef IS_RETURN
|
|
|
|
case O_REJECT:
|
|
/*
|
|
* Drop the packet and send a reject notice
|
|
* if the packet is not ICMP (or is an ICMP
|
|
* query), and it is not multicast/broadcast.
|
|
*/
|
|
if (hlen > 0 && is_ipv4 && offset == 0 &&
|
|
(proto != IPPROTO_ICMP ||
|
|
is_icmp_query(ICMP(ulp))) &&
|
|
!(m->m_flags & (M_BCAST|M_MCAST)) &&
|
|
!IN_MULTICAST(ntohl(dst_ip.s_addr))) {
|
|
send_reject(args, cmd->arg1, iplen, ip);
|
|
m = args->m;
|
|
}
|
|
/* FALLTHROUGH */
|
|
#ifdef INET6
|
|
case O_UNREACH6:
|
|
if (hlen > 0 && is_ipv6 &&
|
|
((offset & IP6F_OFF_MASK) == 0) &&
|
|
(proto != IPPROTO_ICMPV6 ||
|
|
(is_icmp6_query(icmp6_type) == 1)) &&
|
|
!(m->m_flags & (M_BCAST|M_MCAST)) &&
|
|
!IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) {
|
|
send_reject6(
|
|
args, cmd->arg1, hlen,
|
|
(struct ip6_hdr *)ip);
|
|
m = args->m;
|
|
}
|
|
/* FALLTHROUGH */
|
|
#endif
|
|
case O_DENY:
|
|
retval = IP_FW_DENY;
|
|
l = 0; /* exit inner loop */
|
|
done = 1; /* exit outer loop */
|
|
break;
|
|
|
|
case O_FORWARD_IP:
|
|
if (args->eh) /* not valid on layer2 pkts */
|
|
break;
|
|
if (q == NULL || q->rule != f ||
|
|
dyn_dir == MATCH_FORWARD) {
|
|
struct sockaddr_in *sa;
|
|
sa = &(((ipfw_insn_sa *)cmd)->sa);
|
|
if (sa->sin_addr.s_addr == INADDR_ANY) {
|
|
bcopy(sa, &args->hopstore,
|
|
sizeof(*sa));
|
|
args->hopstore.sin_addr.s_addr =
|
|
htonl(tablearg);
|
|
args->next_hop = &args->hopstore;
|
|
} else {
|
|
args->next_hop = sa;
|
|
}
|
|
}
|
|
retval = IP_FW_PASS;
|
|
l = 0; /* exit inner loop */
|
|
done = 1; /* exit outer loop */
|
|
break;
|
|
|
|
#ifdef INET6
|
|
case O_FORWARD_IP6:
|
|
if (args->eh) /* not valid on layer2 pkts */
|
|
break;
|
|
if (q == NULL || q->rule != f ||
|
|
dyn_dir == MATCH_FORWARD) {
|
|
struct sockaddr_in6 *sin6;
|
|
|
|
sin6 = &(((ipfw_insn_sa6 *)cmd)->sa);
|
|
args->next_hop6 = sin6;
|
|
}
|
|
retval = IP_FW_PASS;
|
|
l = 0; /* exit inner loop */
|
|
done = 1; /* exit outer loop */
|
|
break;
|
|
#endif
|
|
|
|
case O_NETGRAPH:
|
|
case O_NGTEE:
|
|
set_match(args, f_pos, chain);
|
|
args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ?
|
|
tablearg : cmd->arg1;
|
|
if (V_fw_one_pass)
|
|
args->rule.info |= IPFW_ONEPASS;
|
|
retval = (cmd->opcode == O_NETGRAPH) ?
|
|
IP_FW_NETGRAPH : IP_FW_NGTEE;
|
|
l = 0; /* exit inner loop */
|
|
done = 1; /* exit outer loop */
|
|
break;
|
|
|
|
case O_SETFIB: {
|
|
uint32_t fib;
|
|
|
|
f->pcnt++; /* update stats */
|
|
f->bcnt += pktlen;
|
|
f->timestamp = time_uptime;
|
|
fib = (cmd->arg1 == IP_FW_TABLEARG) ? tablearg:
|
|
cmd->arg1;
|
|
if (fib >= rt_numfibs)
|
|
fib = 0;
|
|
M_SETFIB(m, fib);
|
|
args->f_id.fib = fib;
|
|
l = 0; /* exit inner loop */
|
|
break;
|
|
}
|
|
|
|
case O_NAT:
|
|
if (!IPFW_NAT_LOADED) {
|
|
retval = IP_FW_DENY;
|
|
} else {
|
|
struct cfg_nat *t;
|
|
int nat_id;
|
|
|
|
set_match(args, f_pos, chain);
|
|
/* Check if this is 'global' nat rule */
|
|
if (cmd->arg1 == 0) {
|
|
retval = ipfw_nat_ptr(args, NULL, m);
|
|
l = 0;
|
|
done = 1;
|
|
break;
|
|
}
|
|
t = ((ipfw_insn_nat *)cmd)->nat;
|
|
if (t == NULL) {
|
|
nat_id = (cmd->arg1 == IP_FW_TABLEARG) ?
|
|
tablearg : cmd->arg1;
|
|
t = (*lookup_nat_ptr)(&chain->nat, nat_id);
|
|
|
|
if (t == NULL) {
|
|
retval = IP_FW_DENY;
|
|
l = 0; /* exit inner loop */
|
|
done = 1; /* exit outer loop */
|
|
break;
|
|
}
|
|
if (cmd->arg1 != IP_FW_TABLEARG)
|
|
((ipfw_insn_nat *)cmd)->nat = t;
|
|
}
|
|
retval = ipfw_nat_ptr(args, t, m);
|
|
}
|
|
l = 0; /* exit inner loop */
|
|
done = 1; /* exit outer loop */
|
|
break;
|
|
|
|
case O_REASS: {
|
|
int ip_off;
|
|
|
|
f->pcnt++;
|
|
f->bcnt += pktlen;
|
|
l = 0; /* in any case exit inner loop */
|
|
ip_off = ntohs(ip->ip_off);
|
|
|
|
/* if not fragmented, go to next rule */
|
|
if ((ip_off & (IP_MF | IP_OFFMASK)) == 0)
|
|
break;
|
|
/*
|
|
* ip_reass() expects len & off in host
|
|
* byte order.
|
|
*/
|
|
SET_HOST_IPLEN(ip);
|
|
|
|
args->m = m = ip_reass(m);
|
|
|
|
/*
|
|
* do IP header checksum fixup.
|
|
*/
|
|
if (m == NULL) { /* fragment got swallowed */
|
|
retval = IP_FW_DENY;
|
|
} else { /* good, packet complete */
|
|
int hlen;
|
|
|
|
ip = mtod(m, struct ip *);
|
|
hlen = ip->ip_hl << 2;
|
|
SET_NET_IPLEN(ip);
|
|
ip->ip_sum = 0;
|
|
if (hlen == sizeof(struct ip))
|
|
ip->ip_sum = in_cksum_hdr(ip);
|
|
else
|
|
ip->ip_sum = in_cksum(m, hlen);
|
|
retval = IP_FW_REASS;
|
|
set_match(args, f_pos, chain);
|
|
}
|
|
done = 1; /* exit outer loop */
|
|
break;
|
|
}
|
|
|
|
default:
|
|
panic("-- unknown opcode %d\n", cmd->opcode);
|
|
} /* end of switch() on opcodes */
|
|
/*
|
|
* if we get here with l=0, then match is irrelevant.
|
|
*/
|
|
|
|
if (cmd->len & F_NOT)
|
|
match = !match;
|
|
|
|
if (match) {
|
|
if (cmd->len & F_OR)
|
|
skip_or = 1;
|
|
} else {
|
|
if (!(cmd->len & F_OR)) /* not an OR block, */
|
|
break; /* try next rule */
|
|
}
|
|
|
|
} /* end of inner loop, scan opcodes */
|
|
#undef PULLUP_LEN
|
|
|
|
if (done)
|
|
break;
|
|
|
|
/* next_rule:; */ /* try next rule */
|
|
|
|
} /* end of outer for, scan rules */
|
|
|
|
if (done) {
|
|
struct ip_fw *rule = chain->map[f_pos];
|
|
/* Update statistics */
|
|
rule->pcnt++;
|
|
rule->bcnt += pktlen;
|
|
rule->timestamp = time_uptime;
|
|
} else {
|
|
retval = IP_FW_DENY;
|
|
printf("ipfw: ouch!, skip past end of rules, denying packet\n");
|
|
}
|
|
IPFW_RUNLOCK(chain);
|
|
#ifdef __FreeBSD__
|
|
if (ucred_cache != NULL)
|
|
crfree(ucred_cache);
|
|
#endif
|
|
return (retval);
|
|
|
|
pullup_failed:
|
|
if (V_fw_verbose)
|
|
printf("ipfw: pullup failed\n");
|
|
return (IP_FW_DENY);
|
|
}
|
|
|
|
/*
|
|
* Set maximum number of tables that can be used in given VNET ipfw instance.
|
|
*/
|
|
#ifdef SYSCTL_NODE
|
|
static int
|
|
sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
int error;
|
|
unsigned int ntables;
|
|
|
|
ntables = V_fw_tables_max;
|
|
|
|
error = sysctl_handle_int(oidp, &ntables, 0, req);
|
|
/* Read operation or some error */
|
|
if ((error != 0) || (req->newptr == NULL))
|
|
return (error);
|
|
|
|
return (ipfw_resize_tables(&V_layer3_chain, ntables));
|
|
}
|
|
#endif
|
|
/*
|
|
* Module and VNET glue
|
|
*/
|
|
|
|
/*
|
|
* Stuff that must be initialised only on boot or module load
|
|
*/
|
|
static int
|
|
ipfw_init(void)
|
|
{
|
|
int error = 0;
|
|
|
|
ipfw_dyn_attach();
|
|
/*
|
|
* Only print out this stuff the first time around,
|
|
* when called from the sysinit code.
|
|
*/
|
|
printf("ipfw2 "
|
|
#ifdef INET6
|
|
"(+ipv6) "
|
|
#endif
|
|
"initialized, divert %s, nat %s, "
|
|
"rule-based forwarding "
|
|
#ifdef IPFIREWALL_FORWARD
|
|
"enabled, "
|
|
#else
|
|
"disabled, "
|
|
#endif
|
|
"default to %s, logging ",
|
|
#ifdef IPDIVERT
|
|
"enabled",
|
|
#else
|
|
"loadable",
|
|
#endif
|
|
#ifdef IPFIREWALL_NAT
|
|
"enabled",
|
|
#else
|
|
"loadable",
|
|
#endif
|
|
default_to_accept ? "accept" : "deny");
|
|
|
|
/*
|
|
* Note: V_xxx variables can be accessed here but the vnet specific
|
|
* initializer may not have been called yet for the VIMAGE case.
|
|
* Tuneables will have been processed. We will print out values for
|
|
* the default vnet.
|
|
* XXX This should all be rationalized AFTER 8.0
|
|
*/
|
|
if (V_fw_verbose == 0)
|
|
printf("disabled\n");
|
|
else if (V_verbose_limit == 0)
|
|
printf("unlimited\n");
|
|
else
|
|
printf("limited to %d packets/entry by default\n",
|
|
V_verbose_limit);
|
|
|
|
/* Check user-supplied table count for validness */
|
|
if (default_fw_tables > IPFW_TABLES_MAX)
|
|
default_fw_tables = IPFW_TABLES_MAX;
|
|
|
|
ipfw_log_bpf(1); /* init */
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Called for the removal of the last instance only on module unload.
|
|
*/
|
|
static void
|
|
ipfw_destroy(void)
|
|
{
|
|
|
|
ipfw_log_bpf(0); /* uninit */
|
|
ipfw_dyn_detach();
|
|
printf("IP firewall unloaded\n");
|
|
}
|
|
|
|
/*
|
|
* Stuff that must be initialized for every instance
|
|
* (including the first of course).
|
|
*/
|
|
static int
|
|
vnet_ipfw_init(const void *unused)
|
|
{
|
|
int error;
|
|
struct ip_fw *rule = NULL;
|
|
struct ip_fw_chain *chain;
|
|
|
|
chain = &V_layer3_chain;
|
|
|
|
/* First set up some values that are compile time options */
|
|
V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */
|
|
V_fw_deny_unknown_exthdrs = 1;
|
|
#ifdef IPFIREWALL_VERBOSE
|
|
V_fw_verbose = 1;
|
|
#endif
|
|
#ifdef IPFIREWALL_VERBOSE_LIMIT
|
|
V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
|
|
#endif
|
|
#ifdef IPFIREWALL_NAT
|
|
LIST_INIT(&chain->nat);
|
|
#endif
|
|
|
|
/* insert the default rule and create the initial map */
|
|
chain->n_rules = 1;
|
|
chain->static_len = sizeof(struct ip_fw);
|
|
chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_WAITOK | M_ZERO);
|
|
if (chain->map)
|
|
rule = malloc(chain->static_len, M_IPFW, M_WAITOK | M_ZERO);
|
|
|
|
/* Set initial number of tables */
|
|
V_fw_tables_max = default_fw_tables;
|
|
error = ipfw_init_tables(chain);
|
|
if (error) {
|
|
printf("ipfw2: setting up tables failed\n");
|
|
free(chain->map, M_IPFW);
|
|
free(rule, M_IPFW);
|
|
return (ENOSPC);
|
|
}
|
|
|
|
/* fill and insert the default rule */
|
|
rule->act_ofs = 0;
|
|
rule->rulenum = IPFW_DEFAULT_RULE;
|
|
rule->cmd_len = 1;
|
|
rule->set = RESVD_SET;
|
|
rule->cmd[0].len = 1;
|
|
rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY;
|
|
chain->rules = chain->default_rule = chain->map[0] = rule;
|
|
chain->id = rule->id = 1;
|
|
|
|
IPFW_LOCK_INIT(chain);
|
|
ipfw_dyn_init();
|
|
|
|
/* First set up some values that are compile time options */
|
|
V_ipfw_vnet_ready = 1; /* Open for business */
|
|
|
|
/*
|
|
* Hook the sockopt handler and pfil hooks for ipv4 and ipv6.
|
|
* Even if the latter two fail we still keep the module alive
|
|
* because the sockopt and layer2 paths are still useful.
|
|
* ipfw[6]_hook return 0 on success, ENOENT on failure,
|
|
* so we can ignore the exact return value and just set a flag.
|
|
*
|
|
* Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so
|
|
* changes in the underlying (per-vnet) variables trigger
|
|
* immediate hook()/unhook() calls.
|
|
* In layer2 we have the same behaviour, except that V_ether_ipfw
|
|
* is checked on each packet because there are no pfil hooks.
|
|
*/
|
|
V_ip_fw_ctl_ptr = ipfw_ctl;
|
|
error = ipfw_attach_hooks(1);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Called for the removal of each instance.
|
|
*/
|
|
static int
|
|
vnet_ipfw_uninit(const void *unused)
|
|
{
|
|
struct ip_fw *reap, *rule;
|
|
struct ip_fw_chain *chain = &V_layer3_chain;
|
|
int i;
|
|
|
|
V_ipfw_vnet_ready = 0; /* tell new callers to go away */
|
|
/*
|
|
* disconnect from ipv4, ipv6, layer2 and sockopt.
|
|
* Then grab, release and grab again the WLOCK so we make
|
|
* sure the update is propagated and nobody will be in.
|
|
*/
|
|
(void)ipfw_attach_hooks(0 /* detach */);
|
|
V_ip_fw_ctl_ptr = NULL;
|
|
IPFW_UH_WLOCK(chain);
|
|
IPFW_UH_WUNLOCK(chain);
|
|
IPFW_UH_WLOCK(chain);
|
|
|
|
IPFW_WLOCK(chain);
|
|
ipfw_dyn_uninit(0); /* run the callout_drain */
|
|
IPFW_WUNLOCK(chain);
|
|
|
|
ipfw_destroy_tables(chain);
|
|
reap = NULL;
|
|
IPFW_WLOCK(chain);
|
|
for (i = 0; i < chain->n_rules; i++) {
|
|
rule = chain->map[i];
|
|
rule->x_next = reap;
|
|
reap = rule;
|
|
}
|
|
if (chain->map)
|
|
free(chain->map, M_IPFW);
|
|
IPFW_WUNLOCK(chain);
|
|
IPFW_UH_WUNLOCK(chain);
|
|
if (reap != NULL)
|
|
ipfw_reap_rules(reap);
|
|
IPFW_LOCK_DESTROY(chain);
|
|
ipfw_dyn_uninit(1); /* free the remaining parts */
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Module event handler.
|
|
* In general we have the choice of handling most of these events by the
|
|
* event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to
|
|
* use the SYSINIT handlers as they are more capable of expressing the
|
|
* flow of control during module and vnet operations, so this is just
|
|
* a skeleton. Note there is no SYSINIT equivalent of the module
|
|
* SHUTDOWN handler, but we don't have anything to do in that case anyhow.
|
|
*/
|
|
static int
|
|
ipfw_modevent(module_t mod, int type, void *unused)
|
|
{
|
|
int err = 0;
|
|
|
|
switch (type) {
|
|
case MOD_LOAD:
|
|
/* Called once at module load or
|
|
* system boot if compiled in. */
|
|
break;
|
|
case MOD_QUIESCE:
|
|
/* Called before unload. May veto unloading. */
|
|
break;
|
|
case MOD_UNLOAD:
|
|
/* Called during unload. */
|
|
break;
|
|
case MOD_SHUTDOWN:
|
|
/* Called during system shutdown. */
|
|
break;
|
|
default:
|
|
err = EOPNOTSUPP;
|
|
break;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static moduledata_t ipfwmod = {
|
|
"ipfw",
|
|
ipfw_modevent,
|
|
NULL
|
|
};
|
|
|
|
/* Define startup order. */
|
|
#define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_IFATTACHDOMAIN
|
|
#define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */
|
|
#define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */
|
|
#define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */
|
|
|
|
DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER);
|
|
MODULE_VERSION(ipfw, 2);
|
|
/* should declare some dependencies here */
|
|
|
|
/*
|
|
* Starting up. Done in order after ipfwmod() has been called.
|
|
* VNET_SYSINIT is also called for each existing vnet and each new vnet.
|
|
*/
|
|
SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
|
|
ipfw_init, NULL);
|
|
VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
|
|
vnet_ipfw_init, NULL);
|
|
|
|
/*
|
|
* Closing up shop. These are done in REVERSE ORDER, but still
|
|
* after ipfwmod() has been called. Not called on reboot.
|
|
* VNET_SYSUNINIT is also called for each exiting vnet as it exits.
|
|
* or when the module is unloaded.
|
|
*/
|
|
SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
|
|
ipfw_destroy, NULL);
|
|
VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
|
|
vnet_ipfw_uninit, NULL);
|
|
/* end of file */
|