sys/netinet/ipfw/ip_fw2.c

   1 /*-
   2  * Copyright (c) 2002-2009 Luigi Rizzo, Universita` di Pisa
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  23  * SUCH DAMAGE.
  24  */
  25
  26 #include <sys/cdefs.h>
  27 __FBSDID("$FreeBSD$");
  28
  29 /*
  30  * The FreeBSD IP packet firewall, main file
  31  */
  32
  33 #include "opt_ipfw.h"
  34 #include "opt_ipdivert.h"
  35 #include "opt_inet.h"
  36 #ifndef INET
  37 #error IPFIREWALL requires INET.
  38 #endif /* INET */
  39 #include "opt_inet6.h"
  40 #include "opt_ipsec.h"
  41
  42 #include <sys/param.h>
  43 #include <sys/systm.h>
  44 #include <sys/condvar.h>
  45 #include <sys/eventhandler.h>
  46 #include <sys/malloc.h>
  47 #include <sys/mbuf.h>
  48 #include <sys/kernel.h>
  49 #include <sys/lock.h>
  50 #include <sys/jail.h>
  51 #include <sys/module.h>
  52 #include <sys/priv.h>
  53 #include <sys/proc.h>
  54 #include <sys/rwlock.h>
  55 #include <sys/socket.h>
  56 #include <sys/socketvar.h>
  57 #include <sys/sysctl.h>
  58 #include <sys/syslog.h>
  59 #include <sys/ucred.h>
  60 #include <net/ethernet.h> /* for ETHERTYPE_IP */
  61 #include <net/if.h>
  62 #include <net/route.h>
  63 #include <net/pf_mtag.h>
  64 #include <net/vnet.h>
  65
  66 #include <netinet/in.h>
  67 #include <netinet/in_var.h>
  68 #include <netinet/in_pcb.h>
  69 #include <netinet/ip.h>
  70 #include <netinet/ip_var.h>
  71 #include <netinet/ip_icmp.h>
  72 #include <netinet/ip_fw.h>
  73 #include <netinet/ipfw/ip_fw_private.h>
  74 #include <netinet/ip_carp.h>
  75 #include <netinet/pim.h>
  76 #include <netinet/tcp_var.h>
  77 #include <netinet/udp.h>
  78 #include <netinet/udp_var.h>
  79 #include <netinet/sctp.h>
  80
  81 #include <netinet/ip6.h>
  82 #include <netinet/icmp6.h>
  83 #ifdef INET6
  84 #include <netinet6/in6_pcb.h>
  85 #include <netinet6/scope6_var.h>
  86 #include <netinet6/ip6_var.h>
  87 #endif
  88
  89 #include <machine/in_cksum.h>   /* XXX for in_cksum */
  90
  91 #ifdef MAC
  92 #include <security/mac/mac_framework.h>
  93 #endif
  94
  95 /*
  96  * static variables followed by global ones.
  97  * All ipfw global variables are here.
  98  */
  99
 100 /* ipfw_vnet_ready controls when we are open for business */
 101 static VNET_DEFINE(int, ipfw_vnet_ready) = 0;
 102 #define V_ipfw_vnet_ready       VNET(ipfw_vnet_ready)
 103
 104 static VNET_DEFINE(int, fw_deny_unknown_exthdrs);
 105 #define V_fw_deny_unknown_exthdrs       VNET(fw_deny_unknown_exthdrs)
 106
 107 static VNET_DEFINE(int, fw_permit_single_frag6) = 1;
 108 #define V_fw_permit_single_frag6        VNET(fw_permit_single_frag6)
 109
 110 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
 111 static int default_to_accept = 1;
 112 #else
 113 static int default_to_accept;
 114 #endif
 115
 116 VNET_DEFINE(int, autoinc_step);
 117 VNET_DEFINE(int, fw_one_pass) = 1;
 118
 119 /*
 120  * Each rule belongs to one of 32 different sets (0..31).
 121  * The variable set_disable contains one bit per set.
 122  * If the bit is set, all rules in the corresponding set
 123  * are disabled. Set RESVD_SET(31) is reserved for the default rule
 124  * and rules that are not deleted by the flush command,
 125  * and CANNOT be disabled.
 126  * Rules in set RESVD_SET can only be deleted individually.
 127  */
 128 VNET_DEFINE(u_int32_t, set_disable);
 129 #define V_set_disable                   VNET(set_disable)
 130
 131 VNET_DEFINE(int, fw_verbose);
 132 /* counter for ipfw_log(NULL...) */
 133 VNET_DEFINE(u_int64_t, norule_counter);
 134 VNET_DEFINE(int, verbose_limit);
 135
 136 /* layer3_chain contains the list of rules for layer 3 */
 137 VNET_DEFINE(struct ip_fw_chain, layer3_chain);
 138
 139 ipfw_nat_t *ipfw_nat_ptr = NULL;
 140 struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int);
 141 ipfw_nat_cfg_t *ipfw_nat_cfg_ptr;
 142 ipfw_nat_cfg_t *ipfw_nat_del_ptr;
 143 ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr;
 144 ipfw_nat_cfg_t *ipfw_nat_get_log_ptr;
 145
 146 #ifdef SYSCTL_NODE
 147 uint32_t dummy_def = IPFW_DEFAULT_RULE;
 148 uint32_t dummy_tables_max = IPFW_TABLES_MAX;
 149
 150 SYSBEGIN(f3)
 151
 152 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
 153 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, one_pass,
 154     CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0,
 155     "Only do a single pass through ipfw when using dummynet(4)");
 156 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step,
 157     CTLFLAG_RW, &VNET_NAME(autoinc_step), 0,
 158     "Rule number auto-increment step");
 159 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose,
 160     CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0,
 161     "Log matches to ipfw rules");
 162 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit,
 163     CTLFLAG_RW, &VNET_NAME(verbose_limit), 0,
 164     "Set upper limit of matches of ipfw rules logged");
 165 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD,
 166     &dummy_def, 0,
 167     "The default/max possible rule number.");
 168 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, tables_max, CTLFLAG_RD,
 169     &dummy_tables_max, 0,
 170     "The maximum number of tables.");
 171 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN,
 172     &default_to_accept, 0,
 173     "Make the default rule accept all packets.");
 174 TUNABLE_INT("net.inet.ip.fw.default_to_accept", &default_to_accept);
 175 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, static_count,
 176     CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0,
 177     "Number of static rules");
 178
 179 #ifdef INET6
 180 SYSCTL_DECL(_net_inet6_ip6);
 181 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
 182 SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs,
 183     CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_deny_unknown_exthdrs), 0,
 184     "Deny packets with unknown IPv6 Extension Headers");
 185 SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6,
 186     CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_permit_single_frag6), 0,
 187     "Permit single packet IPv6 fragments");
 188 #endif /* INET6 */
 189
 190 SYSEND
 191
 192 #endif /* SYSCTL_NODE */
 193
 194
 195 /*
 196  * Some macros used in the various matching options.
 197  * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T
 198  * Other macros just cast void * into the appropriate type
 199  */
 200 #define L3HDR(T, ip)    ((T *)((u_int32_t *)(ip) + (ip)->ip_hl))
 201 #define TCP(p)          ((struct tcphdr *)(p))
 202 #define SCTP(p)         ((struct sctphdr *)(p))
 203 #define UDP(p)          ((struct udphdr *)(p))
 204 #define ICMP(p)         ((struct icmphdr *)(p))
 205 #define ICMP6(p)        ((struct icmp6_hdr *)(p))
 206
 207 static __inline int
 208 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd)
 209 {
 210         int type = icmp->icmp_type;
 211
 212         return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) );
 213 }
 214
 215 #define TT      ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \
 216     (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) )
 217
 218 static int
 219 is_icmp_query(struct icmphdr *icmp)
 220 {
 221         int type = icmp->icmp_type;
 222
 223         return (type <= ICMP_MAXTYPE && (TT & (1<<type)) );
 224 }
 225 #undef TT
 226
 227 /*
 228  * The following checks use two arrays of 8 or 16 bits to store the
 229  * bits that we want set or clear, respectively. They are in the
 230  * low and high half of cmd->arg1 or cmd->d[0].
 231  *
 232  * We scan options and store the bits we find set. We succeed if
 233  *
 234  *      (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear
 235  *
 236  * The code is sometimes optimized not to store additional variables.
 237  */
 238
 239 static int
 240 flags_match(ipfw_insn *cmd, u_int8_t bits)
 241 {
 242         u_char want_clear;
 243         bits = ~bits;
 244
 245         if ( ((cmd->arg1 & 0xff) & bits) != 0)
 246                 return 0; /* some bits we want set were clear */
 247         want_clear = (cmd->arg1 >> 8) & 0xff;
 248         if ( (want_clear & bits) != want_clear)
 249                 return 0; /* some bits we want clear were set */
 250         return 1;
 251 }
 252
 253 static int
 254 ipopts_match(struct ip *ip, ipfw_insn *cmd)
 255 {
 256         int optlen, bits = 0;
 257         u_char *cp = (u_char *)(ip + 1);
 258         int x = (ip->ip_hl << 2) - sizeof (struct ip);
 259
 260         for (; x > 0; x -= optlen, cp += optlen) {
 261                 int opt = cp[IPOPT_OPTVAL];
 262
 263                 if (opt == IPOPT_EOL)
 264                         break;
 265                 if (opt == IPOPT_NOP)
 266                         optlen = 1;
 267                 else {
 268                         optlen = cp[IPOPT_OLEN];
 269                         if (optlen <= 0 || optlen > x)
 270                                 return 0; /* invalid or truncated */
 271                 }
 272                 switch (opt) {
 273
 274                 default:
 275                         break;
 276
 277                 case IPOPT_LSRR:
 278                         bits |= IP_FW_IPOPT_LSRR;
 279                         break;
 280
 281                 case IPOPT_SSRR:
 282                         bits |= IP_FW_IPOPT_SSRR;
 283                         break;
 284
 285                 case IPOPT_RR:
 286                         bits |= IP_FW_IPOPT_RR;
 287                         break;
 288
 289                 case IPOPT_TS:
 290                         bits |= IP_FW_IPOPT_TS;
 291                         break;
 292                 }
 293         }
 294         return (flags_match(cmd, bits));
 295 }
 296
 297 static int
 298 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd)
 299 {
 300         int optlen, bits = 0;
 301         u_char *cp = (u_char *)(tcp + 1);
 302         int x = (tcp->th_off << 2) - sizeof(struct tcphdr);
 303
 304         for (; x > 0; x -= optlen, cp += optlen) {
 305                 int opt = cp[0];
 306                 if (opt == TCPOPT_EOL)
 307                         break;
 308                 if (opt == TCPOPT_NOP)
 309                         optlen = 1;
 310                 else {
 311                         optlen = cp[1];
 312                         if (optlen <= 0)
 313                                 break;
 314                 }
 315
 316                 switch (opt) {
 317
 318                 default:
 319                         break;
 320
 321                 case TCPOPT_MAXSEG:
 322                         bits |= IP_FW_TCPOPT_MSS;
 323                         break;
 324
 325                 case TCPOPT_WINDOW:
 326                         bits |= IP_FW_TCPOPT_WINDOW;
 327                         break;
 328
 329                 case TCPOPT_SACK_PERMITTED:
 330                 case TCPOPT_SACK:
 331                         bits |= IP_FW_TCPOPT_SACK;
 332                         break;
 333
 334                 case TCPOPT_TIMESTAMP:
 335                         bits |= IP_FW_TCPOPT_TS;
 336                         break;
 337
 338                 }
 339         }
 340         return (flags_match(cmd, bits));
 341 }
 342
 343 static int
 344 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd)
 345 {
 346         if (ifp == NULL)        /* no iface with this packet, match fails */
 347                 return 0;
 348         /* Check by name or by IP address */
 349         if (cmd->name[0] != '\0') { /* match by name */
 350                 /* Check name */
 351                 if (cmd->p.glob) {
 352                         if (fnmatch(cmd->name, ifp->if_xname, 0) == 0)
 353                                 return(1);
 354                 } else {
 355                         if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0)
 356                                 return(1);
 357                 }
 358         } else {
 359 #ifdef __FreeBSD__      /* and OSX too ? */
 360                 struct ifaddr *ia;
 361
 362                 if_addr_rlock(ifp);
 363                 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
 364                         if (ia->ifa_addr->sa_family != AF_INET)
 365                                 continue;
 366                         if (cmd->p.ip.s_addr == ((struct sockaddr_in *)
 367                             (ia->ifa_addr))->sin_addr.s_addr) {
 368                                 if_addr_runlock(ifp);
 369                                 return(1);      /* match */
 370                         }
 371                 }
 372                 if_addr_runlock(ifp);
 373 #endif /* __FreeBSD__ */
 374         }
 375         return(0);      /* no match, fail ... */
 376 }
 377
 378 /*
 379  * The verify_path function checks if a route to the src exists and
 380  * if it is reachable via ifp (when provided).
 381  *
 382  * The 'verrevpath' option checks that the interface that an IP packet
 383  * arrives on is the same interface that traffic destined for the
 384  * packet's source address would be routed out of.
 385  * The 'versrcreach' option just checks that the source address is
 386  * reachable via any route (except default) in the routing table.
 387  * These two are a measure to block forged packets. This is also
 388  * commonly known as "anti-spoofing" or Unicast Reverse Path
 389  * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs
 390  * is purposely reminiscent of the Cisco IOS command,
 391  *
 392  *   ip verify unicast reverse-path
 393  *   ip verify unicast source reachable-via any
 394  *
 395  * which implements the same functionality. But note that the syntax
 396  * is misleading, and the check may be performed on all IP packets
 397  * whether unicast, multicast, or broadcast.
 398  */
 399 static int
 400 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib)
 401 {
 402 #ifndef __FreeBSD__
 403         return 0;
 404 #else
 405         struct route ro;
 406         struct sockaddr_in *dst;
 407
 408         bzero(&ro, sizeof(ro));
 409
 410         dst = (struct sockaddr_in *)&(ro.ro_dst);
 411         dst->sin_family = AF_INET;
 412         dst->sin_len = sizeof(*dst);
 413         dst->sin_addr = src;
 414         in_rtalloc_ign(&ro, 0, fib);
 415
 416         if (ro.ro_rt == NULL)
 417                 return 0;
 418
 419         /*
 420          * If ifp is provided, check for equality with rtentry.
 421          * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
 422          * in order to pass packets injected back by if_simloop():
 423          * if useloopback == 1 routing entry (via lo0) for our own address
 424          * may exist, so we need to handle routing assymetry.
 425          */
 426         if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) {
 427                 RTFREE(ro.ro_rt);
 428                 return 0;
 429         }
 430
 431         /* if no ifp provided, check if rtentry is not default route */
 432         if (ifp == NULL &&
 433              satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) {
 434                 RTFREE(ro.ro_rt);
 435                 return 0;
 436         }
 437
 438         /* or if this is a blackhole/reject route */
 439         if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
 440                 RTFREE(ro.ro_rt);
 441                 return 0;
 442         }
 443
 444         /* found valid route */
 445         RTFREE(ro.ro_rt);
 446         return 1;
 447 #endif /* __FreeBSD__ */
 448 }
 449
 450 #ifdef INET6
 451 /*
 452  * ipv6 specific rules here...
 453  */
 454 static __inline int
 455 icmp6type_match (int type, ipfw_insn_u32 *cmd)
 456 {
 457         return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) );
 458 }
 459
 460 static int
 461 flow6id_match( int curr_flow, ipfw_insn_u32 *cmd )
 462 {
 463         int i;
 464         for (i=0; i <= cmd->o.arg1; ++i )
 465                 if (curr_flow == cmd->d[i] )
 466                         return 1;
 467         return 0;
 468 }
 469
 470 /* support for IP6_*_ME opcodes */
 471 static int
 472 search_ip6_addr_net (struct in6_addr * ip6_addr)
 473 {
 474         struct ifnet *mdc;
 475         struct ifaddr *mdc2;
 476         struct in6_ifaddr *fdm;
 477         struct in6_addr copia;
 478
 479         TAILQ_FOREACH(mdc, &V_ifnet, if_link) {
 480                 if_addr_rlock(mdc);
 481                 TAILQ_FOREACH(mdc2, &mdc->if_addrhead, ifa_link) {
 482                         if (mdc2->ifa_addr->sa_family == AF_INET6) {
 483                                 fdm = (struct in6_ifaddr *)mdc2;
 484                                 copia = fdm->ia_addr.sin6_addr;
 485                                 /* need for leaving scope_id in the sock_addr */
 486                                 in6_clearscope(&copia);
 487                                 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) {
 488                                         if_addr_runlock(mdc);
 489                                         return 1;
 490                                 }
 491                         }
 492                 }
 493                 if_addr_runlock(mdc);
 494         }
 495         return 0;
 496 }
 497
 498 static int
 499 verify_path6(struct in6_addr *src, struct ifnet *ifp)
 500 {
 501         struct route_in6 ro;
 502         struct sockaddr_in6 *dst;
 503
 504         bzero(&ro, sizeof(ro));
 505
 506         dst = (struct sockaddr_in6 * )&(ro.ro_dst);
 507         dst->sin6_family = AF_INET6;
 508         dst->sin6_len = sizeof(*dst);
 509         dst->sin6_addr = *src;
 510         /* XXX MRT 0 for ipv6 at this time */
 511         rtalloc_ign((struct route *)&ro, 0);
 512
 513         if (ro.ro_rt == NULL)
 514                 return 0;
 515
 516         /*
 517          * if ifp is provided, check for equality with rtentry
 518          * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
 519          * to support the case of sending packets to an address of our own.
 520          * (where the former interface is the first argument of if_simloop()
 521          *  (=ifp), the latter is lo0)
 522          */
 523         if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) {
 524                 RTFREE(ro.ro_rt);
 525                 return 0;
 526         }
 527
 528         /* if no ifp provided, check if rtentry is not default route */
 529         if (ifp == NULL &&
 530             IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) {
 531                 RTFREE(ro.ro_rt);
 532                 return 0;
 533         }
 534
 535         /* or if this is a blackhole/reject route */
 536         if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
 537                 RTFREE(ro.ro_rt);
 538                 return 0;
 539         }
 540
 541         /* found valid route */
 542         RTFREE(ro.ro_rt);
 543         return 1;
 544
 545 }
 546
 547 static int
 548 is_icmp6_query(int icmp6_type)
 549 {
 550         if ((icmp6_type <= ICMP6_MAXTYPE) &&
 551             (icmp6_type == ICMP6_ECHO_REQUEST ||
 552             icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
 553             icmp6_type == ICMP6_WRUREQUEST ||
 554             icmp6_type == ICMP6_FQDN_QUERY ||
 555             icmp6_type == ICMP6_NI_QUERY))
 556                 return (1);
 557
 558         return (0);
 559 }
 560
 561 static void
 562 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6)
 563 {
 564         struct mbuf *m;
 565
 566         m = args->m;
 567         if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) {
 568                 struct tcphdr *tcp;
 569                 tcp = (struct tcphdr *)((char *)ip6 + hlen);
 570
 571                 if ((tcp->th_flags & TH_RST) == 0) {
 572                         struct mbuf *m0;
 573                         m0 = ipfw_send_pkt(args->m, &(args->f_id),
 574                             ntohl(tcp->th_seq), ntohl(tcp->th_ack),
 575                             tcp->th_flags | TH_RST);
 576                         if (m0 != NULL)
 577                                 ip6_output(m0, NULL, NULL, 0, NULL, NULL,
 578                                     NULL);
 579                 }
 580                 FREE_PKT(m);
 581         } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */
 582 #if 0
 583                 /*
 584                  * Unlike above, the mbufs need to line up with the ip6 hdr,
 585                  * as the contents are read. We need to m_adj() the
 586                  * needed amount.
 587                  * The mbuf will however be thrown away so we can adjust it.
 588                  * Remember we did an m_pullup on it already so we
 589                  * can make some assumptions about contiguousness.
 590                  */
 591                 if (args->L3offset)
 592                         m_adj(m, args->L3offset);
 593 #endif
 594                 icmp6_error(m, ICMP6_DST_UNREACH, code, 0);
 595         } else
 596                 FREE_PKT(m);
 597
 598         args->m = NULL;
 599 }
 600
 601 #endif /* INET6 */
 602
 603
 604 /*
 605  * sends a reject message, consuming the mbuf passed as an argument.
 606  */
 607 static void
 608 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip)
 609 {
 610
 611 #if 0
 612         /* XXX When ip is not guaranteed to be at mtod() we will
 613          * need to account for this */
 614          * The mbuf will however be thrown away so we can adjust it.
 615          * Remember we did an m_pullup on it already so we
 616          * can make some assumptions about contiguousness.
 617          */
 618         if (args->L3offset)
 619                 m_adj(m, args->L3offset);
 620 #endif
 621         if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */
 622                 /* We need the IP header in host order for icmp_error(). */
 623                 SET_HOST_IPLEN(ip);
 624                 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
 625         } else if (args->f_id.proto == IPPROTO_TCP) {
 626                 struct tcphdr *const tcp =
 627                     L3HDR(struct tcphdr, mtod(args->m, struct ip *));
 628                 if ( (tcp->th_flags & TH_RST) == 0) {
 629                         struct mbuf *m;
 630                         m = ipfw_send_pkt(args->m, &(args->f_id),
 631                                 ntohl(tcp->th_seq), ntohl(tcp->th_ack),
 632                                 tcp->th_flags | TH_RST);
 633                         if (m != NULL)
 634                                 ip_output(m, NULL, NULL, 0, NULL, NULL);
 635                 }
 636                 FREE_PKT(args->m);
 637         } else
 638                 FREE_PKT(args->m);
 639         args->m = NULL;
 640 }
 641
 642 /*
 643  * Support for uid/gid/jail lookup. These tests are expensive
 644  * (because we may need to look into the list of active sockets)
 645  * so we cache the results. ugid_lookupp is 0 if we have not
 646  * yet done a lookup, 1 if we succeeded, and -1 if we tried
 647  * and failed. The function always returns the match value.
 648  * We could actually spare the variable and use *uc, setting
 649  * it to '(void *)check_uidgid if we have no info, NULL if
 650  * we tried and failed, or any other value if successful.
 651  */
 652 static int
 653 check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp,
 654     struct ucred **uc)
 655 {
 656 #ifndef __FreeBSD__
 657         /* XXX */
 658         return cred_check(insn, proto, oif,
 659             dst_ip, dst_port, src_ip, src_port,
 660             (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb);
 661 #else  /* FreeBSD */
 662         struct in_addr src_ip, dst_ip;
 663         struct inpcbinfo *pi;
 664         struct ipfw_flow_id *id;
 665         struct inpcb *pcb, *inp;
 666         struct ifnet *oif;
 667         int lookupflags;
 668         int match;
 669
 670         id = &args->f_id;
 671         inp = args->inp;
 672         oif = args->oif;
 673
 674         /*
 675          * Check to see if the UDP or TCP stack supplied us with
 676          * the PCB. If so, rather then holding a lock and looking
 677          * up the PCB, we can use the one that was supplied.
 678          */
 679         if (inp && *ugid_lookupp == 0) {
 680                 INP_LOCK_ASSERT(inp);
 681                 if (inp->inp_socket != NULL) {
 682                         *uc = crhold(inp->inp_cred);
 683                         *ugid_lookupp = 1;
 684                 } else
 685                         *ugid_lookupp = -1;
 686         }
 687         /*
 688          * If we have already been here and the packet has no
 689          * PCB entry associated with it, then we can safely
 690          * assume that this is a no match.
 691          */
 692         if (*ugid_lookupp == -1)
 693                 return (0);
 694         if (id->proto == IPPROTO_TCP) {
 695                 lookupflags = 0;
 696                 pi = &V_tcbinfo;
 697         } else if (id->proto == IPPROTO_UDP) {
 698                 lookupflags = INPLOOKUP_WILDCARD;
 699                 pi = &V_udbinfo;
 700         } else
 701                 return 0;
 702         lookupflags |= INPLOOKUP_RLOCKPCB;
 703         match = 0;
 704         if (*ugid_lookupp == 0) {
 705                 if (id->addr_type == 6) {
 706 #ifdef INET6
 707                         if (oif == NULL)
 708                                 pcb = in6_pcblookup_mbuf(pi,
 709                                     &id->src_ip6, htons(id->src_port),
 710                                     &id->dst_ip6, htons(id->dst_port),
 711                                     lookupflags, oif, args->m);
 712                         else
 713                                 pcb = in6_pcblookup_mbuf(pi,
 714                                     &id->dst_ip6, htons(id->dst_port),
 715                                     &id->src_ip6, htons(id->src_port),
 716                                     lookupflags, oif, args->m);
 717 #else
 718                         *ugid_lookupp = -1;
 719                         return (0);
 720 #endif
 721                 } else {
 722                         src_ip.s_addr = htonl(id->src_ip);
 723                         dst_ip.s_addr = htonl(id->dst_ip);
 724                         if (oif == NULL)
 725                                 pcb = in_pcblookup_mbuf(pi,
 726                                     src_ip, htons(id->src_port),
 727                                     dst_ip, htons(id->dst_port),
 728                                     lookupflags, oif, args->m);
 729                         else
 730                                 pcb = in_pcblookup_mbuf(pi,
 731                                     dst_ip, htons(id->dst_port),
 732                                     src_ip, htons(id->src_port),
 733                                     lookupflags, oif, args->m);
 734                 }
 735                 if (pcb != NULL) {
 736                         INP_RLOCK_ASSERT(pcb);
 737                         *uc = crhold(pcb->inp_cred);
 738                         *ugid_lookupp = 1;
 739                         INP_RUNLOCK(pcb);
 740                 }
 741                 if (*ugid_lookupp == 0) {
 742                         /*
 743                          * We tried and failed, set the variable to -1
 744                          * so we will not try again on this packet.
 745                          */
 746                         *ugid_lookupp = -1;
 747                         return (0);
 748                 }
 749         }
 750         if (insn->o.opcode == O_UID)
 751                 match = ((*uc)->cr_uid == (uid_t)insn->d[0]);
 752         else if (insn->o.opcode == O_GID)
 753                 match = groupmember((gid_t)insn->d[0], *uc);
 754         else if (insn->o.opcode == O_JAIL)
 755                 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]);
 756         return (match);
 757 #endif /* __FreeBSD__ */
 758 }
 759
 760 /*
 761  * Helper function to set args with info on the rule after the matching
 762  * one. slot is precise, whereas we guess rule_id as they are
 763  * assigned sequentially.
 764  */
 765 static inline void
 766 set_match(struct ip_fw_args *args, int slot,
 767         struct ip_fw_chain *chain)
 768 {
 769         args->rule.chain_id = chain->id;
 770         args->rule.slot = slot + 1; /* we use 0 as a marker */
 771         args->rule.rule_id = 1 + chain->map[slot]->id;
 772         args->rule.rulenum = chain->map[slot]->rulenum;
 773 }
 774
 775 /*
 776  * The main check routine for the firewall.
 777  *
 778  * All arguments are in args so we can modify them and return them
 779  * back to the caller.
 780  *
 781  * Parameters:
 782  *
 783  *      args->m (in/out) The packet; we set to NULL when/if we nuke it.
 784  *              Starts with the IP header.
 785  *      args->eh (in)   Mac header if present, NULL for layer3 packet.
 786  *      args->L3offset  Number of bytes bypassed if we came from L2.
 787  *                      e.g. often sizeof(eh)  ** NOTYET **
 788  *      args->oif       Outgoing interface, NULL if packet is incoming.
 789  *              The incoming interface is in the mbuf. (in)
 790  *      args->divert_rule (in/out)
 791  *              Skip up to the first rule past this rule number;
 792  *              upon return, non-zero port number for divert or tee.
 793  *
 794  *      args->rule      Pointer to the last matching rule (in/out)
 795  *      args->next_hop  Socket we are forwarding to (out).
 796  *      args->next_hop6 IPv6 next hop we are forwarding to (out).
 797  *      args->f_id      Addresses grabbed from the packet (out)
 798  *      args->rule.info a cookie depending on rule action
 799  *
 800  * Return value:
 801  *
 802  *      IP_FW_PASS      the packet must be accepted
 803  *      IP_FW_DENY      the packet must be dropped
 804  *      IP_FW_DIVERT    divert packet, port in m_tag
 805  *      IP_FW_TEE       tee packet, port in m_tag
 806  *      IP_FW_DUMMYNET  to dummynet, pipe in args->cookie
 807  *      IP_FW_NETGRAPH  into netgraph, cookie args->cookie
 808  *              args->rule contains the matching rule,
 809  *              args->rule.info has additional information.
 810  *
 811  */
 812 int
 813 ipfw_chk(struct ip_fw_args *args)
 814 {
 815
 816         /*
 817          * Local variables holding state while processing a packet:
 818          *
 819          * IMPORTANT NOTE: to speed up the processing of rules, there
 820          * are some assumption on the values of the variables, which
 821          * are documented here. Should you change them, please check
 822          * the implementation of the various instructions to make sure
 823          * that they still work.
 824          *
 825          * args->eh     The MAC header. It is non-null for a layer2
 826          *      packet, it is NULL for a layer-3 packet.
 827          * **notyet**
 828          * args->L3offset Offset in the packet to the L3 (IP or equiv.) header.
 829          *
 830          * m | args->m  Pointer to the mbuf, as received from the caller.
 831          *      It may change if ipfw_chk() does an m_pullup, or if it
 832          *      consumes the packet because it calls send_reject().
 833          *      XXX This has to change, so that ipfw_chk() never modifies
 834          *      or consumes the buffer.
 835          * ip   is the beginning of the ip(4 or 6) header.
 836          *      Calculated by adding the L3offset to the start of data.
 837          *      (Until we start using L3offset, the packet is
 838          *      supposed to start with the ip header).
 839          */
 840         struct mbuf *m = args->m;
 841         struct ip *ip = mtod(m, struct ip *);
 842
 843         /*
 844          * For rules which contain uid/gid or jail constraints, cache
 845          * a copy of the users credentials after the pcb lookup has been
 846          * executed. This will speed up the processing of rules with
 847          * these types of constraints, as well as decrease contention
 848          * on pcb related locks.
 849          */
 850 #ifndef __FreeBSD__
 851         struct bsd_ucred ucred_cache;
 852 #else
 853         struct ucred *ucred_cache = NULL;
 854 #endif
 855         int ucred_lookup = 0;
 856
 857         /*
 858          * oif | args->oif      If NULL, ipfw_chk has been called on the
 859          *      inbound path (ether_input, ip_input).
 860          *      If non-NULL, ipfw_chk has been called on the outbound path
 861          *      (ether_output, ip_output).
 862          */
 863         struct ifnet *oif = args->oif;
 864
 865         int f_pos = 0;          /* index of current rule in the array */
 866         int retval = 0;
 867
 868         /*
 869          * hlen The length of the IP header.
 870          */
 871         u_int hlen = 0;         /* hlen >0 means we have an IP pkt */
 872
 873         /*
 874          * offset       The offset of a fragment. offset != 0 means that
 875          *      we have a fragment at this offset of an IPv4 packet.
 876          *      offset == 0 means that (if this is an IPv4 packet)
 877          *      this is the first or only fragment.
 878          *      For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header
 879          *      or there is a single packet fragement (fragement header added
 880          *      without needed).  We will treat a single packet fragment as if
 881          *      there was no fragment header (or log/block depending on the
 882          *      V_fw_permit_single_frag6 sysctl setting).
 883          */
 884         u_short offset = 0;
 885         u_short ip6f_mf = 0;
 886
 887         /*
 888          * Local copies of addresses. They are only valid if we have
 889          * an IP packet.
 890          *
 891          * proto        The protocol. Set to 0 for non-ip packets,
 892          *      or to the protocol read from the packet otherwise.
 893          *      proto != 0 means that we have an IPv4 packet.
 894          *
 895          * src_port, dst_port   port numbers, in HOST format. Only
 896          *      valid for TCP and UDP packets.
 897          *
 898          * src_ip, dst_ip       ip addresses, in NETWORK format.
 899          *      Only valid for IPv4 packets.
 900          */
 901         uint8_t proto;
 902         uint16_t src_port = 0, dst_port = 0;    /* NOTE: host format    */
 903         struct in_addr src_ip, dst_ip;          /* NOTE: network format */
 904         uint16_t iplen=0;
 905         int pktlen;
 906         uint16_t        etype = 0;      /* Host order stored ether type */
 907
 908         /*
 909          * dyn_dir = MATCH_UNKNOWN when rules unchecked,
 910          *      MATCH_NONE when checked and not matched (q = NULL),
 911          *      MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL)
 912          */
 913         int dyn_dir = MATCH_UNKNOWN;
 914         ipfw_dyn_rule *q = NULL;
 915         struct ip_fw_chain *chain = &V_layer3_chain;
 916
 917         /*
 918          * We store in ulp a pointer to the upper layer protocol header.
 919          * In the ipv4 case this is easy to determine from the header,
 920          * but for ipv6 we might have some additional headers in the middle.
 921          * ulp is NULL if not found.
 922          */
 923         void *ulp = NULL;               /* upper layer protocol pointer. */
 924
 925         /* XXX ipv6 variables */
 926         int is_ipv6 = 0;
 927         uint8_t icmp6_type = 0;
 928         uint16_t ext_hd = 0;    /* bits vector for extension header filtering */
 929         /* end of ipv6 variables */
 930
 931         int is_ipv4 = 0;
 932
 933         int done = 0;           /* flag to exit the outer loop */
 934
 935         if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready))
 936                 return (IP_FW_PASS);    /* accept */
 937
 938         dst_ip.s_addr = 0;              /* make sure it is initialized */
 939         src_ip.s_addr = 0;              /* make sure it is initialized */
 940         pktlen = m->m_pkthdr.len;
 941         args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */
 942         proto = args->f_id.proto = 0;   /* mark f_id invalid */
 943                 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */
 944
 945 /*
 946  * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous,
 947  * then it sets p to point at the offset "len" in the mbuf. WARNING: the
 948  * pointer might become stale after other pullups (but we never use it
 949  * this way).
 950  */
 951 #define PULLUP_TO(_len, p, T)   PULLUP_LEN(_len, p, sizeof(T))
 952 #define PULLUP_LEN(_len, p, T)                                  \
 953 do {                                                            \
 954         int x = (_len) + T;                                     \
 955         if ((m)->m_len < x) {                                   \
 956                 args->m = m = m_pullup(m, x);                   \
 957                 if (m == NULL)                                  \
 958                         goto pullup_failed;                     \
 959         }                                                       \
 960         p = (mtod(m, char *) + (_len));                         \
 961 } while (0)
 962
 963         /*
 964          * if we have an ether header,
 965          */
 966         if (args->eh)
 967                 etype = ntohs(args->eh->ether_type);
 968
 969         /* Identify IP packets and fill up variables. */
 970         if (pktlen >= sizeof(struct ip6_hdr) &&
 971             (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) {
 972                 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip;
 973                 is_ipv6 = 1;
 974                 args->f_id.addr_type = 6;
 975                 hlen = sizeof(struct ip6_hdr);
 976                 proto = ip6->ip6_nxt;
 977
 978                 /* Search extension headers to find upper layer protocols */
 979                 while (ulp == NULL && offset == 0) {
 980                         switch (proto) {
 981                         case IPPROTO_ICMPV6:
 982                                 PULLUP_TO(hlen, ulp, struct icmp6_hdr);
 983                                 icmp6_type = ICMP6(ulp)->icmp6_type;
 984                                 break;
 985
 986                         case IPPROTO_TCP:
 987                                 PULLUP_TO(hlen, ulp, struct tcphdr);
 988                                 dst_port = TCP(ulp)->th_dport;
 989                                 src_port = TCP(ulp)->th_sport;
 990                                 /* save flags for dynamic rules */
 991                                 args->f_id._flags = TCP(ulp)->th_flags;
 992                                 break;
 993
 994                         case IPPROTO_SCTP:
 995                                 PULLUP_TO(hlen, ulp, struct sctphdr);
 996                                 src_port = SCTP(ulp)->src_port;
 997                                 dst_port = SCTP(ulp)->dest_port;
 998                                 break;
 999
1000                         case IPPROTO_UDP:
1001                                 PULLUP_TO(hlen, ulp, struct udphdr);
1002                                 dst_port = UDP(ulp)->uh_dport;
1003                                 src_port = UDP(ulp)->uh_sport;
1004                                 break;
1005
1006                         case IPPROTO_HOPOPTS:   /* RFC 2460 */
1007                                 PULLUP_TO(hlen, ulp, struct ip6_hbh);
1008                                 ext_hd |= EXT_HOPOPTS;
1009                                 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
1010                                 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
1011                                 ulp = NULL;
1012                                 break;
1013
1014                         case IPPROTO_ROUTING:   /* RFC 2460 */
1015                                 PULLUP_TO(hlen, ulp, struct ip6_rthdr);
1016                                 switch (((struct ip6_rthdr *)ulp)->ip6r_type) {
1017                                 case 0:
1018                                         ext_hd |= EXT_RTHDR0;
1019                                         break;
1020                                 case 2:
1021                                         ext_hd |= EXT_RTHDR2;
1022                                         break;
1023                                 default:
1024                                         if (V_fw_verbose)
1025                                                 printf("IPFW2: IPV6 - Unknown "
1026                                                     "Routing Header type(%d)\n",
1027                                                     ((struct ip6_rthdr *)
1028                                                     ulp)->ip6r_type);
1029                                         if (V_fw_deny_unknown_exthdrs)
1030                                             return (IP_FW_DENY);
1031                                         break;
1032                                 }
1033                                 ext_hd |= EXT_ROUTING;
1034                                 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3;
1035                                 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt;
1036                                 ulp = NULL;
1037                                 break;
1038
1039                         case IPPROTO_FRAGMENT:  /* RFC 2460 */
1040                                 PULLUP_TO(hlen, ulp, struct ip6_frag);
1041                                 ext_hd |= EXT_FRAGMENT;
1042                                 hlen += sizeof (struct ip6_frag);
1043                                 proto = ((struct ip6_frag *)ulp)->ip6f_nxt;
1044                                 offset = ((struct ip6_frag *)ulp)->ip6f_offlg &
1045                                         IP6F_OFF_MASK;
1046                                 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg &
1047                                         IP6F_MORE_FRAG;
1048                                 if (V_fw_permit_single_frag6 == 0 &&
1049                                     offset == 0 && ip6f_mf == 0) {
1050                                         if (V_fw_verbose)
1051                                                 printf("IPFW2: IPV6 - Invalid "
1052                                                     "Fragment Header\n");
1053                                         if (V_fw_deny_unknown_exthdrs)
1054                                             return (IP_FW_DENY);
1055                                         break;
1056                                 }
1057                                 args->f_id.extra =
1058                                     ntohl(((struct ip6_frag *)ulp)->ip6f_ident);
1059                                 ulp = NULL;
1060                                 break;
1061
1062                         case IPPROTO_DSTOPTS:   /* RFC 2460 */
1063                                 PULLUP_TO(hlen, ulp, struct ip6_hbh);
1064                                 ext_hd |= EXT_DSTOPTS;
1065                                 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
1066                                 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
1067                                 ulp = NULL;
1068                                 break;
1069
1070                         case IPPROTO_AH:        /* RFC 2402 */
1071                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
1072                                 ext_hd |= EXT_AH;
1073                                 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2;
1074                                 proto = ((struct ip6_ext *)ulp)->ip6e_nxt;
1075                                 ulp = NULL;
1076                                 break;
1077
1078                         case IPPROTO_ESP:       /* RFC 2406 */
1079                                 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */
1080                                 /* Anything past Seq# is variable length and
1081                                  * data past this ext. header is encrypted. */
1082                                 ext_hd |= EXT_ESP;
1083                                 break;
1084
1085                         case IPPROTO_NONE:      /* RFC 2460 */
1086                                 /*
1087                                  * Packet ends here, and IPv6 header has
1088                                  * already been pulled up. If ip6e_len!=0
1089                                  * then octets must be ignored.
1090                                  */
1091                                 ulp = ip; /* non-NULL to get out of loop. */
1092                                 break;
1093
1094                         case IPPROTO_OSPFIGP:
1095                                 /* XXX OSPF header check? */
1096                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
1097                                 break;
1098
1099                         case IPPROTO_PIM:
1100                                 /* XXX PIM header check? */
1101                                 PULLUP_TO(hlen, ulp, struct pim);
1102                                 break;
1103
1104                         case IPPROTO_CARP:
1105                                 PULLUP_TO(hlen, ulp, struct carp_header);
1106                                 if (((struct carp_header *)ulp)->carp_version !=
1107                                     CARP_VERSION)
1108                                         return (IP_FW_DENY);
1109                                 if (((struct carp_header *)ulp)->carp_type !=
1110                                     CARP_ADVERTISEMENT)
1111                                         return (IP_FW_DENY);
1112                                 break;
1113
1114                         case IPPROTO_IPV6:      /* RFC 2893 */
1115                                 PULLUP_TO(hlen, ulp, struct ip6_hdr);
1116                                 break;
1117
1118                         case IPPROTO_IPV4:      /* RFC 2893 */
1119                                 PULLUP_TO(hlen, ulp, struct ip);
1120                                 break;
1121
1122                         default:
1123                                 if (V_fw_verbose)
1124                                         printf("IPFW2: IPV6 - Unknown "
1125                                             "Extension Header(%d), ext_hd=%x\n",
1126                                              proto, ext_hd);
1127                                 if (V_fw_deny_unknown_exthdrs)
1128                                     return (IP_FW_DENY);
1129                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
1130                                 break;
1131                         } /*switch */
1132                 }
1133                 ip = mtod(m, struct ip *);
1134                 ip6 = (struct ip6_hdr *)ip;
1135                 args->f_id.src_ip6 = ip6->ip6_src;
1136                 args->f_id.dst_ip6 = ip6->ip6_dst;
1137                 args->f_id.src_ip = 0;
1138                 args->f_id.dst_ip = 0;
1139                 args->f_id.flow_id6 = ntohl(ip6->ip6_flow);
1140         } else if (pktlen >= sizeof(struct ip) &&
1141             (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) {
1142                 is_ipv4 = 1;
1143                 hlen = ip->ip_hl << 2;
1144                 args->f_id.addr_type = 4;
1145
1146                 /*
1147                  * Collect parameters into local variables for faster matching.
1148                  */
1149                 proto = ip->ip_p;
1150                 src_ip = ip->ip_src;
1151                 dst_ip = ip->ip_dst;
1152                 offset = ntohs(ip->ip_off) & IP_OFFMASK;
1153                 iplen = ntohs(ip->ip_len);
1154                 pktlen = iplen < pktlen ? iplen : pktlen;
1155
1156                 if (offset == 0) {
1157                         switch (proto) {
1158                         case IPPROTO_TCP:
1159                                 PULLUP_TO(hlen, ulp, struct tcphdr);
1160                                 dst_port = TCP(ulp)->th_dport;
1161                                 src_port = TCP(ulp)->th_sport;
1162                                 /* save flags for dynamic rules */
1163                                 args->f_id._flags = TCP(ulp)->th_flags;
1164                                 break;
1165
1166                         case IPPROTO_SCTP:
1167                                 PULLUP_TO(hlen, ulp, struct sctphdr);
1168                                 src_port = SCTP(ulp)->src_port;
1169                                 dst_port = SCTP(ulp)->dest_port;
1170                                 break;
1171
1172                         case IPPROTO_UDP:
1173                                 PULLUP_TO(hlen, ulp, struct udphdr);
1174                                 dst_port = UDP(ulp)->uh_dport;
1175                                 src_port = UDP(ulp)->uh_sport;
1176                                 break;
1177
1178                         case IPPROTO_ICMP:
1179                                 PULLUP_TO(hlen, ulp, struct icmphdr);
1180                                 //args->f_id.flags = ICMP(ulp)->icmp_type;
1181                                 break;
1182
1183                         default:
1184                                 break;
1185                         }
1186                 }
1187
1188                 ip = mtod(m, struct ip *);
1189                 args->f_id.src_ip = ntohl(src_ip.s_addr);
1190                 args->f_id.dst_ip = ntohl(dst_ip.s_addr);
1191         }
1192 #undef PULLUP_TO
1193         if (proto) { /* we may have port numbers, store them */
1194                 args->f_id.proto = proto;
1195                 args->f_id.src_port = src_port = ntohs(src_port);
1196                 args->f_id.dst_port = dst_port = ntohs(dst_port);
1197         }
1198
1199         IPFW_RLOCK(chain);
1200         if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */
1201                 IPFW_RUNLOCK(chain);
1202                 return (IP_FW_PASS);    /* accept */
1203         }
1204         if (args->rule.slot) {
1205                 /*
1206                  * Packet has already been tagged as a result of a previous
1207                  * match on rule args->rule aka args->rule_id (PIPE, QUEUE,
1208                  * REASS, NETGRAPH, DIVERT/TEE...)
1209                  * Validate the slot and continue from the next one
1210                  * if still present, otherwise do a lookup.
1211                  */
1212                 f_pos = (args->rule.chain_id == chain->id) ?
1213                     args->rule.slot :
1214                     ipfw_find_rule(chain, args->rule.rulenum,
1215                         args->rule.rule_id);
1216         } else {
1217                 f_pos = 0;
1218         }
1219
1220         /*
1221          * Now scan the rules, and parse microinstructions for each rule.
1222          * We have two nested loops and an inner switch. Sometimes we
1223          * need to break out of one or both loops, or re-enter one of
1224          * the loops with updated variables. Loop variables are:
1225          *
1226          *      f_pos (outer loop) points to the current rule.
1227          *              On output it points to the matching rule.
1228          *      done (outer loop) is used as a flag to break the loop.
1229          *      l (inner loop)  residual length of current rule.
1230          *              cmd points to the current microinstruction.
1231          *
1232          * We break the inner loop by setting l=0 and possibly
1233          * cmdlen=0 if we don't want to advance cmd.
1234          * We break the outer loop by setting done=1
1235          * We can restart the inner loop by setting l>0 and f_pos, f, cmd
1236          * as needed.
1237          */
1238         for (; f_pos < chain->n_rules; f_pos++) {
1239                 ipfw_insn *cmd;
1240                 uint32_t tablearg = 0;
1241                 int l, cmdlen, skip_or; /* skip rest of OR block */
1242                 struct ip_fw *f;
1243
1244                 f = chain->map[f_pos];
1245                 if (V_set_disable & (1 << f->set) )
1246                         continue;
1247
1248                 skip_or = 0;
1249                 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ;
1250                     l -= cmdlen, cmd += cmdlen) {
1251                         int match;
1252
1253                         /*
1254                          * check_body is a jump target used when we find a
1255                          * CHECK_STATE, and need to jump to the body of
1256                          * the target rule.
1257                          */
1258
1259 /* check_body: */
1260                         cmdlen = F_LEN(cmd);
1261                         /*
1262                          * An OR block (insn_1 || .. || insn_n) has the
1263                          * F_OR bit set in all but the last instruction.
1264                          * The first match will set "skip_or", and cause
1265                          * the following instructions to be skipped until
1266                          * past the one with the F_OR bit clear.
1267                          */
1268                         if (skip_or) {          /* skip this instruction */
1269                                 if ((cmd->len & F_OR) == 0)
1270                                         skip_or = 0;    /* next one is good */
1271                                 continue;
1272                         }
1273                         match = 0; /* set to 1 if we succeed */
1274
1275                         switch (cmd->opcode) {
1276                         /*
1277                          * The first set of opcodes compares the packet's
1278                          * fields with some pattern, setting 'match' if a
1279                          * match is found. At the end of the loop there is
1280                          * logic to deal with F_NOT and F_OR flags associated
1281                          * with the opcode.
1282                          */
1283                         case O_NOP:
1284                                 match = 1;
1285                                 break;
1286
1287                         case O_FORWARD_MAC:
1288                                 printf("ipfw: opcode %d unimplemented\n",
1289                                     cmd->opcode);
1290                                 break;
1291
1292                         case O_GID:
1293                         case O_UID:
1294                         case O_JAIL:
1295                                 /*
1296                                  * We only check offset == 0 && proto != 0,
1297                                  * as this ensures that we have a
1298                                  * packet with the ports info.
1299                                  */
1300                                 if (offset != 0)
1301                                         break;
1302                                 if (proto == IPPROTO_TCP ||
1303                                     proto == IPPROTO_UDP)
1304                                         match = check_uidgid(
1305                                                     (ipfw_insn_u32 *)cmd,
1306                                                     args, &ucred_lookup,
1307 #ifdef __FreeBSD__
1308                                                     &ucred_cache);
1309 #else
1310                                                     (void *)&ucred_cache);
1311 #endif
1312                                 break;
1313
1314                         case O_RECV:
1315                                 match = iface_match(m->m_pkthdr.rcvif,
1316                                     (ipfw_insn_if *)cmd);
1317                                 break;
1318
1319                         case O_XMIT:
1320                                 match = iface_match(oif, (ipfw_insn_if *)cmd);
1321                                 break;
1322
1323                         case O_VIA:
1324                                 match = iface_match(oif ? oif :
1325                                     m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd);
1326                                 break;
1327
1328                         case O_MACADDR2:
1329                                 if (args->eh != NULL) { /* have MAC header */
1330                                         u_int32_t *want = (u_int32_t *)
1331                                                 ((ipfw_insn_mac *)cmd)->addr;
1332                                         u_int32_t *mask = (u_int32_t *)
1333                                                 ((ipfw_insn_mac *)cmd)->mask;
1334                                         u_int32_t *hdr = (u_int32_t *)args->eh;
1335
1336                                         match =
1337                                             ( want[0] == (hdr[0] & mask[0]) &&
1338                                               want[1] == (hdr[1] & mask[1]) &&
1339                                               want[2] == (hdr[2] & mask[2]) );
1340                                 }
1341                                 break;
1342
1343                         case O_MAC_TYPE:
1344                                 if (args->eh != NULL) {
1345                                         u_int16_t *p =
1346                                             ((ipfw_insn_u16 *)cmd)->ports;
1347                                         int i;
1348
1349                                         for (i = cmdlen - 1; !match && i>0;
1350                                             i--, p += 2)
1351                                                 match = (etype >= p[0] &&
1352                                                     etype <= p[1]);
1353                                 }
1354                                 break;
1355
1356                         case O_FRAG:
1357                                 match = (offset != 0);
1358                                 break;
1359
1360                         case O_IN:      /* "out" is "not in" */
1361                                 match = (oif == NULL);
1362                                 break;
1363
1364                         case O_LAYER2:
1365                                 match = (args->eh != NULL);
1366                                 break;
1367
1368                         case O_DIVERTED:
1369                             {
1370                                 /* For diverted packets, args->rule.info
1371                                  * contains the divert port (in host format)
1372                                  * reason and direction.
1373                                  */
1374                                 uint32_t i = args->rule.info;
1375                                 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT &&
1376                                     cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2);
1377                             }
1378                                 break;
1379
1380                         case O_PROTO:
1381                                 /*
1382                                  * We do not allow an arg of 0 so the
1383                                  * check of "proto" only suffices.
1384                                  */
1385                                 match = (proto == cmd->arg1);
1386                                 break;
1387
1388                         case O_IP_SRC:
1389                                 match = is_ipv4 &&
1390                                     (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1391                                     src_ip.s_addr);
1392                                 break;
1393
1394                         case O_IP_SRC_LOOKUP:
1395                         case O_IP_DST_LOOKUP:
1396                                 if (is_ipv4) {
1397                                     uint32_t key =
1398                                         (cmd->opcode == O_IP_DST_LOOKUP) ?
1399                                             dst_ip.s_addr : src_ip.s_addr;
1400                                     uint32_t v = 0;
1401
1402                                     if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) {
1403                                         /* generic lookup. The key must be
1404                                          * in 32bit big-endian format.
1405                                          */
1406                                         v = ((ipfw_insn_u32 *)cmd)->d[1];
1407                                         if (v == 0)
1408                                             key = dst_ip.s_addr;
1409                                         else if (v == 1)
1410                                             key = src_ip.s_addr;
1411                                         else if (v == 6) /* dscp */
1412                                             key = (ip->ip_tos >> 2) & 0x3f;
1413                                         else if (offset != 0)
1414                                             break;
1415                                         else if (proto != IPPROTO_TCP &&
1416                                                 proto != IPPROTO_UDP)
1417                                             break;
1418                                         else if (v == 2)
1419                                             key = htonl(dst_port);
1420                                         else if (v == 3)
1421                                             key = htonl(src_port);
1422                                         else if (v == 4 || v == 5) {
1423                                             check_uidgid(
1424                                                 (ipfw_insn_u32 *)cmd,
1425                                                 args, &ucred_lookup,
1426 #ifdef __FreeBSD__
1427                                                 &ucred_cache);
1428                                             if (v == 4 /* O_UID */)
1429                                                 key = ucred_cache->cr_uid;
1430                                             else if (v == 5 /* O_JAIL */)
1431                                                 key = ucred_cache->cr_prison->pr_id;
1432 #else /* !__FreeBSD__ */
1433                                                 (void *)&ucred_cache);
1434                                             if (v ==4 /* O_UID */)
1435                                                 key = ucred_cache.uid;
1436                                             else if (v == 5 /* O_JAIL */)
1437                                                 key = ucred_cache.xid;
1438 #endif /* !__FreeBSD__ */
1439                                             key = htonl(key);
1440                                         } else
1441                                             break;
1442                                     }
1443                                     match = ipfw_lookup_table(chain,
1444                                         cmd->arg1, key, &v);
1445                                     if (!match)
1446                                         break;
1447                                     if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
1448                                         match =
1449                                             ((ipfw_insn_u32 *)cmd)->d[0] == v;
1450                                     else
1451                                         tablearg = v;
1452                                 }
1453                                 break;
1454
1455                         case O_IP_SRC_MASK:
1456                         case O_IP_DST_MASK:
1457                                 if (is_ipv4) {
1458                                     uint32_t a =
1459                                         (cmd->opcode == O_IP_DST_MASK) ?
1460                                             dst_ip.s_addr : src_ip.s_addr;
1461                                     uint32_t *p = ((ipfw_insn_u32 *)cmd)->d;
1462                                     int i = cmdlen-1;
1463
1464                                     for (; !match && i>0; i-= 2, p+= 2)
1465                                         match = (p[0] == (a & p[1]));
1466                                 }
1467                                 break;
1468
1469                         case O_IP_SRC_ME:
1470                                 if (is_ipv4) {
1471                                         struct ifnet *tif;
1472
1473                                         INADDR_TO_IFP(src_ip, tif);
1474                                         match = (tif != NULL);
1475                                         break;
1476                                 }
1477 #ifdef INET6
1478                                 /* FALLTHROUGH */
1479                         case O_IP6_SRC_ME:
1480                                 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6);
1481 #endif
1482                                 break;
1483
1484                         case O_IP_DST_SET:
1485                         case O_IP_SRC_SET:
1486                                 if (is_ipv4) {
1487                                         u_int32_t *d = (u_int32_t *)(cmd+1);
1488                                         u_int32_t addr =
1489                                             cmd->opcode == O_IP_DST_SET ?
1490                                                 args->f_id.dst_ip :
1491                                                 args->f_id.src_ip;
1492
1493                                             if (addr < d[0])
1494                                                     break;
1495                                             addr -= d[0]; /* subtract base */
1496                                             match = (addr < cmd->arg1) &&
1497                                                 ( d[ 1 + (addr>>5)] &
1498                                                   (1<<(addr & 0x1f)) );
1499                                 }
1500                                 break;
1501
1502                         case O_IP_DST:
1503                                 match = is_ipv4 &&
1504                                     (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1505                                     dst_ip.s_addr);
1506                                 break;
1507
1508                         case O_IP_DST_ME:
1509                                 if (is_ipv4) {
1510                                         struct ifnet *tif;
1511
1512                                         INADDR_TO_IFP(dst_ip, tif);
1513                                         match = (tif != NULL);
1514                                         break;
1515                                 }
1516 #ifdef INET6
1517                                 /* FALLTHROUGH */
1518                         case O_IP6_DST_ME:
1519                                 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6);
1520 #endif
1521                                 break;
1522
1523
1524                         case O_IP_SRCPORT:
1525                         case O_IP_DSTPORT:
1526                                 /*
1527                                  * offset == 0 && proto != 0 is enough
1528                                  * to guarantee that we have a
1529                                  * packet with port info.
1530                                  */
1531                                 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP)
1532                                     && offset == 0) {
1533                                         u_int16_t x =
1534                                             (cmd->opcode == O_IP_SRCPORT) ?
1535                                                 src_port : dst_port ;
1536                                         u_int16_t *p =
1537                                             ((ipfw_insn_u16 *)cmd)->ports;
1538                                         int i;
1539
1540                                         for (i = cmdlen - 1; !match && i>0;
1541                                             i--, p += 2)
1542                                                 match = (x>=p[0] && x<=p[1]);
1543                                 }
1544                                 break;
1545
1546                         case O_ICMPTYPE:
1547                                 match = (offset == 0 && proto==IPPROTO_ICMP &&
1548                                     icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) );
1549                                 break;
1550
1551 #ifdef INET6
1552                         case O_ICMP6TYPE:
1553                                 match = is_ipv6 && offset == 0 &&
1554                                     proto==IPPROTO_ICMPV6 &&
1555                                     icmp6type_match(
1556                                         ICMP6(ulp)->icmp6_type,
1557                                         (ipfw_insn_u32 *)cmd);
1558                                 break;
1559 #endif /* INET6 */
1560
1561                         case O_IPOPT:
1562                                 match = (is_ipv4 &&
1563                                     ipopts_match(ip, cmd) );
1564                                 break;
1565
1566                         case O_IPVER:
1567                                 match = (is_ipv4 &&
1568                                     cmd->arg1 == ip->ip_v);
1569                                 break;
1570
1571                         case O_IPID:
1572                         case O_IPLEN:
1573                         case O_IPTTL:
1574                                 if (is_ipv4) {  /* only for IP packets */
1575                                     uint16_t x;
1576                                     uint16_t *p;
1577                                     int i;
1578
1579                                     if (cmd->opcode == O_IPLEN)
1580                                         x = iplen;
1581                                     else if (cmd->opcode == O_IPTTL)
1582                                         x = ip->ip_ttl;
1583                                     else /* must be IPID */
1584                                         x = ntohs(ip->ip_id);
1585                                     if (cmdlen == 1) {
1586                                         match = (cmd->arg1 == x);
1587                                         break;
1588                                     }
1589                                     /* otherwise we have ranges */
1590                                     p = ((ipfw_insn_u16 *)cmd)->ports;
1591                                     i = cmdlen - 1;
1592                                     for (; !match && i>0; i--, p += 2)
1593                                         match = (x >= p[0] && x <= p[1]);
1594                                 }
1595                                 break;
1596
1597                         case O_IPPRECEDENCE:
1598                                 match = (is_ipv4 &&
1599                                     (cmd->arg1 == (ip->ip_tos & 0xe0)) );
1600                                 break;
1601
1602                         case O_IPTOS:
1603                                 match = (is_ipv4 &&
1604                                     flags_match(cmd, ip->ip_tos));
1605                                 break;
1606
1607                         case O_TCPDATALEN:
1608                                 if (proto == IPPROTO_TCP && offset == 0) {
1609                                     struct tcphdr *tcp;
1610                                     uint16_t x;
1611                                     uint16_t *p;
1612                                     int i;
1613
1614                                     tcp = TCP(ulp);
1615                                     x = iplen -
1616                                         ((ip->ip_hl + tcp->th_off) << 2);
1617                                     if (cmdlen == 1) {
1618                                         match = (cmd->arg1 == x);
1619                                         break;
1620                                     }
1621                                     /* otherwise we have ranges */
1622                                     p = ((ipfw_insn_u16 *)cmd)->ports;
1623                                     i = cmdlen - 1;
1624                                     for (; !match && i>0; i--, p += 2)
1625                                         match = (x >= p[0] && x <= p[1]);
1626                                 }
1627                                 break;
1628
1629                         case O_TCPFLAGS:
1630                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1631                                     flags_match(cmd, TCP(ulp)->th_flags));
1632                                 break;
1633
1634                         case O_TCPOPTS:
1635                                 PULLUP_LEN(hlen, ulp, (TCP(ulp)->th_off << 2));
1636                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1637                                     tcpopts_match(TCP(ulp), cmd));
1638                                 break;
1639
1640                         case O_TCPSEQ:
1641                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1642                                     ((ipfw_insn_u32 *)cmd)->d[0] ==
1643                                         TCP(ulp)->th_seq);
1644                                 break;
1645
1646                         case O_TCPACK:
1647                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1648                                     ((ipfw_insn_u32 *)cmd)->d[0] ==
1649                                         TCP(ulp)->th_ack);
1650                                 break;
1651
1652                         case O_TCPWIN:
1653                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1654                                     cmd->arg1 == TCP(ulp)->th_win);
1655                                 break;
1656
1657                         case O_ESTAB:
1658                                 /* reject packets which have SYN only */
1659                                 /* XXX should i also check for TH_ACK ? */
1660                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1661                                     (TCP(ulp)->th_flags &
1662                                      (TH_RST | TH_ACK | TH_SYN)) != TH_SYN);
1663                                 break;
1664
1665                         case O_ALTQ: {
1666                                 struct pf_mtag *at;
1667                                 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd;
1668
1669                                 match = 1;
1670                                 at = pf_find_mtag(m);
1671                                 if (at != NULL && at->qid != 0)
1672                                         break;
1673                                 at = pf_get_mtag(m);
1674                                 if (at == NULL) {
1675                                         /*
1676                                          * Let the packet fall back to the
1677                                          * default ALTQ.
1678                                          */
1679                                         break;
1680                                 }
1681                                 at->qid = altq->qid;
1682                                 at->hdr = ip;
1683                                 break;
1684                         }
1685
1686                         case O_LOG:
1687                                 ipfw_log(f, hlen, args, m,
1688                                     oif, offset | ip6f_mf, tablearg, ip);
1689                                 match = 1;
1690                                 break;
1691
1692                         case O_PROB:
1693                                 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]);
1694                                 break;
1695
1696                         case O_VERREVPATH:
1697                                 /* Outgoing packets automatically pass/match */
1698                                 match = ((oif != NULL) ||
1699                                     (m->m_pkthdr.rcvif == NULL) ||
1700                                     (
1701 #ifdef INET6
1702                                     is_ipv6 ?
1703                                         verify_path6(&(args->f_id.src_ip6),
1704                                             m->m_pkthdr.rcvif) :
1705 #endif
1706                                     verify_path(src_ip, m->m_pkthdr.rcvif,
1707                                         args->f_id.fib)));
1708                                 break;
1709
1710                         case O_VERSRCREACH:
1711                                 /* Outgoing packets automatically pass/match */
1712                                 match = (hlen > 0 && ((oif != NULL) ||
1713 #ifdef INET6
1714                                     is_ipv6 ?
1715                                         verify_path6(&(args->f_id.src_ip6),
1716                                             NULL) :
1717 #endif
1718                                     verify_path(src_ip, NULL, args->f_id.fib)));
1719                                 break;
1720
1721                         case O_ANTISPOOF:
1722                                 /* Outgoing packets automatically pass/match */
1723                                 if (oif == NULL && hlen > 0 &&
1724                                     (  (is_ipv4 && in_localaddr(src_ip))
1725 #ifdef INET6
1726                                     || (is_ipv6 &&
1727                                         in6_localaddr(&(args->f_id.src_ip6)))
1728 #endif
1729                                     ))
1730                                         match =
1731 #ifdef INET6
1732                                             is_ipv6 ? verify_path6(
1733                                                 &(args->f_id.src_ip6),
1734                                                 m->m_pkthdr.rcvif) :
1735 #endif
1736                                             verify_path(src_ip,
1737                                                 m->m_pkthdr.rcvif,
1738                                                 args->f_id.fib);
1739                                 else
1740                                         match = 1;
1741                                 break;
1742
1743                         case O_IPSEC:
1744 #ifdef IPSEC
1745                                 match = (m_tag_find(m,
1746                                     PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL);
1747 #endif
1748                                 /* otherwise no match */
1749                                 break;
1750
1751 #ifdef INET6
1752                         case O_IP6_SRC:
1753                                 match = is_ipv6 &&
1754                                     IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6,
1755                                     &((ipfw_insn_ip6 *)cmd)->addr6);
1756                                 break;
1757
1758                         case O_IP6_DST:
1759                                 match = is_ipv6 &&
1760                                 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6,
1761                                     &((ipfw_insn_ip6 *)cmd)->addr6);
1762                                 break;
1763                         case O_IP6_SRC_MASK:
1764                         case O_IP6_DST_MASK:
1765                                 if (is_ipv6) {
1766                                         int i = cmdlen - 1;
1767                                         struct in6_addr p;
1768                                         struct in6_addr *d =
1769                                             &((ipfw_insn_ip6 *)cmd)->addr6;
1770
1771                                         for (; !match && i > 0; d += 2,
1772                                             i -= F_INSN_SIZE(struct in6_addr)
1773                                             * 2) {
1774                                                 p = (cmd->opcode ==
1775                                                     O_IP6_SRC_MASK) ?
1776                                                     args->f_id.src_ip6:
1777                                                     args->f_id.dst_ip6;
1778                                                 APPLY_MASK(&p, &d[1]);
1779                                                 match =
1780                                                     IN6_ARE_ADDR_EQUAL(&d[0],
1781                                                     &p);
1782                                         }
1783                                 }
1784                                 break;
1785
1786                         case O_FLOW6ID:
1787                                 match = is_ipv6 &&
1788                                     flow6id_match(args->f_id.flow_id6,
1789                                     (ipfw_insn_u32 *) cmd);
1790                                 break;
1791
1792                         case O_EXT_HDR:
1793                                 match = is_ipv6 &&
1794                                     (ext_hd & ((ipfw_insn *) cmd)->arg1);
1795                                 break;
1796
1797                         case O_IP6:
1798                                 match = is_ipv6;
1799                                 break;
1800 #endif
1801
1802                         case O_IP4:
1803                                 match = is_ipv4;
1804                                 break;
1805
1806                         case O_TAG: {
1807                                 struct m_tag *mtag;
1808                                 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ?
1809                                     tablearg : cmd->arg1;
1810
1811                                 /* Packet is already tagged with this tag? */
1812                                 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL);
1813
1814                                 /* We have `untag' action when F_NOT flag is
1815                                  * present. And we must remove this mtag from
1816                                  * mbuf and reset `match' to zero (`match' will
1817                                  * be inversed later).
1818                                  * Otherwise we should allocate new mtag and
1819                                  * push it into mbuf.
1820                                  */
1821                                 if (cmd->len & F_NOT) { /* `untag' action */
1822                                         if (mtag != NULL)
1823                                                 m_tag_delete(m, mtag);
1824                                         match = 0;
1825                                 } else {
1826                                         if (mtag == NULL) {
1827                                                 mtag = m_tag_alloc( MTAG_IPFW,
1828                                                     tag, 0, M_NOWAIT);
1829                                                 if (mtag != NULL)
1830                                                         m_tag_prepend(m, mtag);
1831                                         }
1832                                         match = 1;
1833                                 }
1834                                 break;
1835                         }
1836
1837                         case O_FIB: /* try match the specified fib */
1838                                 if (args->f_id.fib == cmd->arg1)
1839                                         match = 1;
1840                                 break;
1841
1842                         case O_SOCKARG: {
1843                                 struct inpcb *inp = args->inp;
1844                                 struct inpcbinfo *pi;
1845
1846                                 if (is_ipv6) /* XXX can we remove this ? */
1847                                         break;
1848
1849                                 if (proto == IPPROTO_TCP)
1850                                         pi = &V_tcbinfo;
1851                                 else if (proto == IPPROTO_UDP)
1852                                         pi = &V_udbinfo;
1853                                 else
1854                                         break;
1855
1856                                 /*
1857                                  * XXXRW: so_user_cookie should almost
1858                                  * certainly be inp_user_cookie?
1859                                  */
1860
1861                                 /* For incomming packet, lookup up the
1862                                 inpcb using the src/dest ip/port tuple */
1863                                 if (inp == NULL) {
1864                                         inp = in_pcblookup(pi,
1865                                                 src_ip, htons(src_port),
1866                                                 dst_ip, htons(dst_port),
1867                                                 INPLOOKUP_RLOCKPCB, NULL);
1868                                         if (inp != NULL) {
1869                                                 tablearg =
1870                                                     inp->inp_socket->so_user_cookie;
1871                                                 if (tablearg)
1872                                                         match = 1;
1873                                                 INP_RUNLOCK(inp);
1874                                         }
1875                                 } else {
1876                                         if (inp->inp_socket) {
1877                                                 tablearg =
1878                                                     inp->inp_socket->so_user_cookie;
1879                                                 if (tablearg)
1880                                                         match = 1;
1881                                         }
1882                                 }
1883                                 break;
1884                         }
1885
1886                         case O_TAGGED: {
1887                                 struct m_tag *mtag;
1888                                 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ?
1889                                     tablearg : cmd->arg1;
1890
1891                                 if (cmdlen == 1) {
1892                                         match = m_tag_locate(m, MTAG_IPFW,
1893                                             tag, NULL) != NULL;
1894                                         break;
1895                                 }
1896
1897                                 /* we have ranges */
1898                                 for (mtag = m_tag_first(m);
1899                                     mtag != NULL && !match;
1900                                     mtag = m_tag_next(m, mtag)) {
1901                                         uint16_t *p;
1902                                         int i;
1903
1904                                         if (mtag->m_tag_cookie != MTAG_IPFW)
1905                                                 continue;
1906
1907                                         p = ((ipfw_insn_u16 *)cmd)->ports;
1908                                         i = cmdlen - 1;
1909                                         for(; !match && i > 0; i--, p += 2)
1910                                                 match =
1911                                                     mtag->m_tag_id >= p[0] &&
1912                                                     mtag->m_tag_id <= p[1];
1913                                 }
1914                                 break;
1915                         }
1916
1917                         /*
1918                          * The second set of opcodes represents 'actions',
1919                          * i.e. the terminal part of a rule once the packet
1920                          * matches all previous patterns.
1921                          * Typically there is only one action for each rule,
1922                          * and the opcode is stored at the end of the rule
1923                          * (but there are exceptions -- see below).
1924                          *
1925                          * In general, here we set retval and terminate the
1926                          * outer loop (would be a 'break 3' in some language,
1927                          * but we need to set l=0, done=1)
1928                          *
1929                          * Exceptions:
1930                          * O_COUNT and O_SKIPTO actions:
1931                          *   instead of terminating, we jump to the next rule
1932                          *   (setting l=0), or to the SKIPTO target (setting
1933                          *   f/f_len, cmd and l as needed), respectively.
1934                          *
1935                          * O_TAG, O_LOG and O_ALTQ action parameters:
1936                          *   perform some action and set match = 1;
1937                          *
1938                          * O_LIMIT and O_KEEP_STATE: these opcodes are
1939                          *   not real 'actions', and are stored right
1940                          *   before the 'action' part of the rule.
1941                          *   These opcodes try to install an entry in the
1942                          *   state tables; if successful, we continue with
1943                          *   the next opcode (match=1; break;), otherwise
1944                          *   the packet must be dropped (set retval,
1945                          *   break loops with l=0, done=1)
1946                          *
1947                          * O_PROBE_STATE and O_CHECK_STATE: these opcodes
1948                          *   cause a lookup of the state table, and a jump
1949                          *   to the 'action' part of the parent rule
1950                          *   if an entry is found, or
1951                          *   (CHECK_STATE only) a jump to the next rule if
1952                          *   the entry is not found.
1953                          *   The result of the lookup is cached so that
1954                          *   further instances of these opcodes become NOPs.
1955                          *   The jump to the next rule is done by setting
1956                          *   l=0, cmdlen=0.
1957                          */
1958                         case O_LIMIT:
1959                         case O_KEEP_STATE:
1960                                 if (ipfw_install_state(f,
1961                                     (ipfw_insn_limit *)cmd, args, tablearg)) {
1962                                         /* error or limit violation */
1963                                         retval = IP_FW_DENY;
1964                                         l = 0;  /* exit inner loop */
1965                                         done = 1; /* exit outer loop */
1966                                 }
1967                                 match = 1;
1968                                 break;
1969
1970                         case O_PROBE_STATE:
1971                         case O_CHECK_STATE:
1972                                 /*
1973                                  * dynamic rules are checked at the first
1974                                  * keep-state or check-state occurrence,
1975                                  * with the result being stored in dyn_dir.
1976                                  * The compiler introduces a PROBE_STATE
1977                                  * instruction for us when we have a
1978                                  * KEEP_STATE (because PROBE_STATE needs
1979                                  * to be run first).
1980                                  */
1981                                 if (dyn_dir == MATCH_UNKNOWN &&
1982                                     (q = ipfw_lookup_dyn_rule(&args->f_id,
1983                                      &dyn_dir, proto == IPPROTO_TCP ?
1984                                         TCP(ulp) : NULL))
1985                                         != NULL) {
1986                                         /*
1987                                          * Found dynamic entry, update stats
1988                                          * and jump to the 'action' part of
1989                                          * the parent rule by setting
1990                                          * f, cmd, l and clearing cmdlen.
1991                                          */
1992                                         q->pcnt++;
1993                                         q->bcnt += pktlen;
1994                                         /* XXX we would like to have f_pos
1995                                          * readily accessible in the dynamic
1996                                          * rule, instead of having to
1997                                          * lookup q->rule.
1998                                          */
1999                                         f = q->rule;
2000                                         f_pos = ipfw_find_rule(chain,
2001                                                 f->rulenum, f->id);
2002                                         cmd = ACTION_PTR(f);
2003                                         l = f->cmd_len - f->act_ofs;
2004                                         ipfw_dyn_unlock();
2005                                         cmdlen = 0;
2006                                         match = 1;
2007                                         break;
2008                                 }
2009                                 /*
2010                                  * Dynamic entry not found. If CHECK_STATE,
2011                                  * skip to next rule, if PROBE_STATE just
2012                                  * ignore and continue with next opcode.
2013                                  */
2014                                 if (cmd->opcode == O_CHECK_STATE)
2015                                         l = 0;  /* exit inner loop */
2016                                 match = 1;
2017                                 break;
2018
2019                         case O_ACCEPT:
2020                                 retval = 0;     /* accept */
2021                                 l = 0;          /* exit inner loop */
2022                                 done = 1;       /* exit outer loop */
2023                                 break;
2024
2025                         case O_PIPE:
2026                         case O_QUEUE:
2027                                 set_match(args, f_pos, chain);
2028                                 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ?
2029                                         tablearg : cmd->arg1;
2030                                 if (cmd->opcode == O_PIPE)
2031                                         args->rule.info |= IPFW_IS_PIPE;
2032                                 if (V_fw_one_pass)
2033                                         args->rule.info |= IPFW_ONEPASS;
2034                                 retval = IP_FW_DUMMYNET;
2035                                 l = 0;          /* exit inner loop */
2036                                 done = 1;       /* exit outer loop */
2037                                 break;
2038
2039                         case O_DIVERT:
2040                         case O_TEE:
2041                                 if (args->eh) /* not on layer 2 */
2042                                     break;
2043                                 /* otherwise this is terminal */
2044                                 l = 0;          /* exit inner loop */
2045                                 done = 1;       /* exit outer loop */
2046                                 retval = (cmd->opcode == O_DIVERT) ?
2047                                         IP_FW_DIVERT : IP_FW_TEE;
2048                                 set_match(args, f_pos, chain);
2049                                 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ?
2050                                     tablearg : cmd->arg1;
2051                                 break;
2052
2053                         case O_COUNT:
2054                                 f->pcnt++;      /* update stats */
2055                                 f->bcnt += pktlen;
2056                                 f->timestamp = time_uptime;
2057                                 l = 0;          /* exit inner loop */
2058                                 break;
2059
2060                         case O_SKIPTO:
2061                             f->pcnt++;  /* update stats */
2062                             f->bcnt += pktlen;
2063                             f->timestamp = time_uptime;
2064                             /* If possible use cached f_pos (in f->next_rule),
2065                              * whose version is written in f->next_rule
2066                              * (horrible hacks to avoid changing the ABI).
2067                              */
2068                             if (cmd->arg1 != IP_FW_TABLEARG &&
2069                                     (uintptr_t)f->x_next == chain->id) {
2070                                 f_pos = (uintptr_t)f->next_rule;
2071                             } else {
2072                                 int i = (cmd->arg1 == IP_FW_TABLEARG) ?
2073                                         tablearg : cmd->arg1;
2074                                 /* make sure we do not jump backward */
2075                                 if (i <= f->rulenum)
2076                                     i = f->rulenum + 1;
2077                                 f_pos = ipfw_find_rule(chain, i, 0);
2078                                 /* update the cache */
2079                                 if (cmd->arg1 != IP_FW_TABLEARG) {
2080                                     f->next_rule =
2081                                         (void *)(uintptr_t)f_pos;
2082                                     f->x_next =
2083                                         (void *)(uintptr_t)chain->id;
2084                                 }
2085                             }
2086                             /*
2087                              * Skip disabled rules, and re-enter
2088                              * the inner loop with the correct
2089                              * f_pos, f, l and cmd.
2090                              * Also clear cmdlen and skip_or
2091                              */
2092                             for (; f_pos < chain->n_rules - 1 &&
2093                                     (V_set_disable &
2094                                      (1 << chain->map[f_pos]->set));
2095                                     f_pos++)
2096                                 ;
2097                             /* Re-enter the inner loop at the skipto rule. */
2098                             f = chain->map[f_pos];
2099                             l = f->cmd_len;
2100                             cmd = f->cmd;
2101                             match = 1;
2102                             cmdlen = 0;
2103                             skip_or = 0;
2104                             continue;
2105                             break;      /* not reached */
2106
2107                         case O_CALLRETURN: {
2108                                 /*
2109                                  * Implementation of `subroutine' call/return,
2110                                  * in the stack carried in an mbuf tag. This
2111                                  * is different from `skipto' in that any call
2112                                  * address is possible (`skipto' must prevent
2113                                  * backward jumps to avoid endless loops).
2114                                  * We have `return' action when F_NOT flag is
2115                                  * present. The `m_tag_id' field is used as
2116                                  * stack pointer.
2117                                  */
2118                                 struct m_tag *mtag;
2119                                 uint16_t jmpto, *stack;
2120
2121 #define IS_CALL         ((cmd->len & F_NOT) == 0)
2122 #define IS_RETURN       ((cmd->len & F_NOT) != 0)
2123                                 /*
2124                                  * Hand-rolled version of m_tag_locate() with
2125                                  * wildcard `type'.
2126                                  * If not already tagged, allocate new tag.
2127                                  */
2128                                 mtag = m_tag_first(m);
2129                                 while (mtag != NULL) {
2130                                         if (mtag->m_tag_cookie ==
2131                                             MTAG_IPFW_CALL)
2132                                                 break;
2133                                         mtag = m_tag_next(m, mtag);
2134                                 }
2135                                 if (mtag == NULL && IS_CALL) {
2136                                         mtag = m_tag_alloc(MTAG_IPFW_CALL, 0,
2137                                             IPFW_CALLSTACK_SIZE *
2138                                             sizeof(uint16_t), M_NOWAIT);
2139                                         if (mtag != NULL)
2140                                                 m_tag_prepend(m, mtag);
2141                                 }
2142
2143                                 /*
2144                                  * On error both `call' and `return' just
2145                                  * continue with next rule.
2146                                  */
2147                                 if (IS_RETURN && (mtag == NULL ||
2148                                     mtag->m_tag_id == 0)) {
2149                                         l = 0;          /* exit inner loop */
2150                                         break;
2151                                 }
2152                                 if (IS_CALL && (mtag == NULL ||
2153                                     mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) {
2154                                         printf("ipfw: call stack error, "
2155                                             "go to next rule\n");
2156                                         l = 0;          /* exit inner loop */
2157                                         break;
2158                                 }
2159
2160                                 f->pcnt++;      /* update stats */
2161                                 f->bcnt += pktlen;
2162                                 f->timestamp = time_uptime;
2163                                 stack = (uint16_t *)(mtag + 1);
2164
2165                                 /*
2166                                  * The `call' action may use cached f_pos
2167                                  * (in f->next_rule), whose version is written
2168                                  * in f->next_rule.
2169                                  * The `return' action, however, doesn't have
2170                                  * fixed jump address in cmd->arg1 and can't use
2171                                  * cache.
2172                                  */
2173                                 if (IS_CALL) {
2174                                         stack[mtag->m_tag_id] = f->rulenum;
2175                                         mtag->m_tag_id++;
2176                                         if (cmd->arg1 != IP_FW_TABLEARG &&
2177                                             (uintptr_t)f->x_next == chain->id) {
2178                                                 f_pos = (uintptr_t)f->next_rule;
2179                                         } else {
2180                                                 jmpto = (cmd->arg1 ==
2181                                                     IP_FW_TABLEARG) ? tablearg:
2182                                                     cmd->arg1;
2183                                                 f_pos = ipfw_find_rule(chain,
2184                                                     jmpto, 0);
2185                                                 /* update the cache */
2186                                                 if (cmd->arg1 !=
2187                                                     IP_FW_TABLEARG) {
2188                                                         f->next_rule =
2189                                                             (void *)(uintptr_t)
2190                                                             f_pos;
2191                                                         f->x_next =
2192                                                             (void *)(uintptr_t)
2193                                                             chain->id;
2194                                                 }
2195                                         }
2196                                 } else {        /* `return' action */
2197                                         mtag->m_tag_id--;
2198                                         jmpto = stack[mtag->m_tag_id] + 1;
2199                                         f_pos = ipfw_find_rule(chain, jmpto, 0);
2200                                 }
2201
2202                                 /*
2203                                  * Skip disabled rules, and re-enter
2204                                  * the inner loop with the correct
2205                                  * f_pos, f, l and cmd.
2206                                  * Also clear cmdlen and skip_or
2207                                  */
2208                                 for (; f_pos < chain->n_rules - 1 &&
2209                                     (V_set_disable &
2210                                     (1 << chain->map[f_pos]->set)); f_pos++)
2211                                         ;
2212                                 /* Re-enter the inner loop at the dest rule. */
2213                                 f = chain->map[f_pos];
2214                                 l = f->cmd_len;
2215                                 cmd = f->cmd;
2216                                 cmdlen = 0;
2217                                 skip_or = 0;
2218                                 continue;
2219                                 break;  /* NOTREACHED */
2220                         }
2221 #undef IS_CALL
2222 #undef IS_RETURN
2223
2224                         case O_REJECT:
2225                                 /*
2226                                  * Drop the packet and send a reject notice
2227                                  * if the packet is not ICMP (or is an ICMP
2228                                  * query), and it is not multicast/broadcast.
2229                                  */
2230                                 if (hlen > 0 && is_ipv4 && offset == 0 &&
2231                                     (proto != IPPROTO_ICMP ||
2232                                      is_icmp_query(ICMP(ulp))) &&
2233                                     !(m->m_flags & (M_BCAST|M_MCAST)) &&
2234                                     !IN_MULTICAST(ntohl(dst_ip.s_addr))) {
2235                                         send_reject(args, cmd->arg1, iplen, ip);
2236                                         m = args->m;
2237                                 }
2238                                 /* FALLTHROUGH */
2239 #ifdef INET6
2240                         case O_UNREACH6:
2241                                 if (hlen > 0 && is_ipv6 &&
2242                                     ((offset & IP6F_OFF_MASK) == 0) &&
2243                                     (proto != IPPROTO_ICMPV6 ||
2244                                      (is_icmp6_query(icmp6_type) == 1)) &&
2245                                     !(m->m_flags & (M_BCAST|M_MCAST)) &&
2246                                     !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) {
2247                                         send_reject6(
2248                                             args, cmd->arg1, hlen,
2249                                             (struct ip6_hdr *)ip);
2250                                         m = args->m;
2251                                 }
2252                                 /* FALLTHROUGH */
2253 #endif
2254                         case O_DENY:
2255                                 retval = IP_FW_DENY;
2256                                 l = 0;          /* exit inner loop */
2257                                 done = 1;       /* exit outer loop */
2258                                 break;
2259
2260                         case O_FORWARD_IP:
2261                                 if (args->eh)   /* not valid on layer2 pkts */
2262                                         break;
2263                                 if (q == NULL || q->rule != f ||
2264                                     dyn_dir == MATCH_FORWARD) {
2265                                     struct sockaddr_in *sa;
2266                                     sa = &(((ipfw_insn_sa *)cmd)->sa);
2267                                     if (sa->sin_addr.s_addr == INADDR_ANY) {
2268                                         bcopy(sa, &args->hopstore,
2269                                                         sizeof(*sa));
2270                                         args->hopstore.sin_addr.s_addr =
2271                                                     htonl(tablearg);
2272                                         args->next_hop = &args->hopstore;
2273                                     } else {
2274                                         args->next_hop = sa;
2275                                     }
2276                                 }
2277                                 retval = IP_FW_PASS;
2278                                 l = 0;          /* exit inner loop */
2279                                 done = 1;       /* exit outer loop */
2280                                 break;
2281
2282 #ifdef INET6
2283                         case O_FORWARD_IP6:
2284                                 if (args->eh)   /* not valid on layer2 pkts */
2285                                         break;
2286                                 if (q == NULL || q->rule != f ||
2287                                     dyn_dir == MATCH_FORWARD) {
2288                                         struct sockaddr_in6 *sin6;
2289
2290                                         sin6 = &(((ipfw_insn_sa6 *)cmd)->sa);
2291                                         args->next_hop6 = sin6;
2292                                 }
2293                                 retval = IP_FW_PASS;
2294                                 l = 0;          /* exit inner loop */
2295                                 done = 1;       /* exit outer loop */
2296                                 break;
2297 #endif
2298
2299                         case O_NETGRAPH:
2300                         case O_NGTEE:
2301                                 set_match(args, f_pos, chain);
2302                                 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ?
2303                                         tablearg : cmd->arg1;
2304                                 if (V_fw_one_pass)
2305                                         args->rule.info |= IPFW_ONEPASS;
2306                                 retval = (cmd->opcode == O_NETGRAPH) ?
2307                                     IP_FW_NETGRAPH : IP_FW_NGTEE;
2308                                 l = 0;          /* exit inner loop */
2309                                 done = 1;       /* exit outer loop */
2310                                 break;
2311
2312                         case O_SETFIB: {
2313                                 uint32_t fib;
2314
2315                                 f->pcnt++;      /* update stats */
2316                                 f->bcnt += pktlen;
2317                                 f->timestamp = time_uptime;
2318                                 fib = (cmd->arg1 == IP_FW_TABLEARG) ? tablearg:
2319                                     cmd->arg1;
2320                                 if (fib >= rt_numfibs)
2321                                         fib = 0;
2322                                 M_SETFIB(m, fib);
2323                                 args->f_id.fib = fib;
2324                                 l = 0;          /* exit inner loop */
2325                                 break;
2326                         }
2327
2328                         case O_NAT:
2329                                 if (!IPFW_NAT_LOADED) {
2330                                     retval = IP_FW_DENY;
2331                                 } else {
2332                                     struct cfg_nat *t;
2333                                     int nat_id;
2334
2335                                     set_match(args, f_pos, chain);
2336                                     /* Check if this is 'global' nat rule */
2337                                     if (cmd->arg1 == 0) {
2338                                             retval = ipfw_nat_ptr(args, NULL, m);
2339                                             l = 0;
2340                                             done = 1;
2341                                             break;
2342                                     }
2343                                     t = ((ipfw_insn_nat *)cmd)->nat;
2344                                     if (t == NULL) {
2345                                         nat_id = (cmd->arg1 == IP_FW_TABLEARG) ?
2346                                                 tablearg : cmd->arg1;
2347                                         t = (*lookup_nat_ptr)(&chain->nat, nat_id);
2348
2349                                         if (t == NULL) {
2350                                             retval = IP_FW_DENY;
2351                                             l = 0;      /* exit inner loop */
2352                                             done = 1;   /* exit outer loop */
2353                                             break;
2354                                         }
2355                                         if (cmd->arg1 != IP_FW_TABLEARG)
2356                                             ((ipfw_insn_nat *)cmd)->nat = t;
2357                                     }
2358                                     retval = ipfw_nat_ptr(args, t, m);
2359                                 }
2360                                 l = 0;          /* exit inner loop */
2361                                 done = 1;       /* exit outer loop */
2362                                 break;
2363
2364                         case O_REASS: {
2365                                 int ip_off;
2366
2367                                 f->pcnt++;
2368                                 f->bcnt += pktlen;
2369                                 l = 0;  /* in any case exit inner loop */
2370                                 ip_off = ntohs(ip->ip_off);
2371
2372                                 /* if not fragmented, go to next rule */
2373                                 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0)
2374                                     break;
2375                                 /*
2376                                  * ip_reass() expects len & off in host
2377                                  * byte order.
2378                                  */
2379                                 SET_HOST_IPLEN(ip);
2380
2381                                 args->m = m = ip_reass(m);
2382
2383                                 /*
2384                                  * do IP header checksum fixup.
2385                                  */
2386                                 if (m == NULL) { /* fragment got swallowed */
2387                                     retval = IP_FW_DENY;
2388                                 } else { /* good, packet complete */
2389                                     int hlen;
2390
2391                                     ip = mtod(m, struct ip *);
2392                                     hlen = ip->ip_hl << 2;
2393                                     SET_NET_IPLEN(ip);
2394                                     ip->ip_sum = 0;
2395                                     if (hlen == sizeof(struct ip))
2396                                         ip->ip_sum = in_cksum_hdr(ip);
2397                                     else
2398                                         ip->ip_sum = in_cksum(m, hlen);
2399                                     retval = IP_FW_REASS;
2400                                     set_match(args, f_pos, chain);
2401                                 }
2402                                 done = 1;       /* exit outer loop */
2403                                 break;
2404                         }
2405
2406                         default:
2407                                 panic("-- unknown opcode %d\n", cmd->opcode);
2408                         } /* end of switch() on opcodes */
2409                         /*
2410                          * if we get here with l=0, then match is irrelevant.
2411                          */
2412
2413                         if (cmd->len & F_NOT)
2414                                 match = !match;
2415
2416                         if (match) {
2417                                 if (cmd->len & F_OR)
2418                                         skip_or = 1;
2419                         } else {
2420                                 if (!(cmd->len & F_OR)) /* not an OR block, */
2421                                         break;          /* try next rule    */
2422                         }
2423
2424                 }       /* end of inner loop, scan opcodes */
2425 #undef PULLUP_LEN
2426
2427                 if (done)
2428                         break;
2429
2430 /* next_rule:; */       /* try next rule                */
2431
2432         }               /* end of outer for, scan rules */
2433
2434         if (done) {
2435                 struct ip_fw *rule = chain->map[f_pos];
2436                 /* Update statistics */
2437                 rule->pcnt++;
2438                 rule->bcnt += pktlen;
2439                 rule->timestamp = time_uptime;
2440         } else {
2441                 retval = IP_FW_DENY;
2442                 printf("ipfw: ouch!, skip past end of rules, denying packet\n");
2443         }
2444         IPFW_RUNLOCK(chain);
2445 #ifdef __FreeBSD__
2446         if (ucred_cache != NULL)
2447                 crfree(ucred_cache);
2448 #endif
2449         return (retval);
2450
2451 pullup_failed:
2452         if (V_fw_verbose)
2453                 printf("ipfw: pullup failed\n");
2454         return (IP_FW_DENY);
2455 }
2456
2457 /*
2458  * Module and VNET glue
2459  */
2460
2461 /*
2462  * Stuff that must be initialised only on boot or module load
2463  */
2464 static int
2465 ipfw_init(void)
2466 {
2467         int error = 0;
2468
2469         ipfw_dyn_attach();
2470         /*
2471          * Only print out this stuff the first time around,
2472          * when called from the sysinit code.
2473          */
2474         printf("ipfw2 "
2475 #ifdef INET6
2476                 "(+ipv6) "
2477 #endif
2478                 "initialized, divert %s, nat %s, "
2479                 "rule-based forwarding "
2480 #ifdef IPFIREWALL_FORWARD
2481                 "enabled, "
2482 #else
2483                 "disabled, "
2484 #endif
2485                 "default to %s, logging ",
2486 #ifdef IPDIVERT
2487                 "enabled",
2488 #else
2489                 "loadable",
2490 #endif
2491 #ifdef IPFIREWALL_NAT
2492                 "enabled",
2493 #else
2494                 "loadable",
2495 #endif
2496                 default_to_accept ? "accept" : "deny");
2497
2498         /*
2499          * Note: V_xxx variables can be accessed here but the vnet specific
2500          * initializer may not have been called yet for the VIMAGE case.
2501          * Tuneables will have been processed. We will print out values for
2502          * the default vnet.
2503          * XXX This should all be rationalized AFTER 8.0
2504          */
2505         if (V_fw_verbose == 0)
2506                 printf("disabled\n");
2507         else if (V_verbose_limit == 0)
2508                 printf("unlimited\n");
2509         else
2510                 printf("limited to %d packets/entry by default\n",
2511                     V_verbose_limit);
2512
2513         ipfw_log_bpf(1); /* init */
2514         return (error);
2515 }
2516
2517 /*
2518  * Called for the removal of the last instance only on module unload.
2519  */
2520 static void
2521 ipfw_destroy(void)
2522 {
2523
2524         ipfw_log_bpf(0); /* uninit */
2525         ipfw_dyn_detach();
2526         printf("IP firewall unloaded\n");
2527 }
2528
2529 /*
2530  * Stuff that must be initialized for every instance
2531  * (including the first of course).
2532  */
2533 static int
2534 vnet_ipfw_init(const void *unused)
2535 {
2536         int error;
2537         struct ip_fw *rule = NULL;
2538         struct ip_fw_chain *chain;
2539
2540         chain = &V_layer3_chain;
2541
2542         /* First set up some values that are compile time options */
2543         V_autoinc_step = 100;   /* bounded to 1..1000 in add_rule() */
2544         V_fw_deny_unknown_exthdrs = 1;
2545 #ifdef IPFIREWALL_VERBOSE
2546         V_fw_verbose = 1;
2547 #endif
2548 #ifdef IPFIREWALL_VERBOSE_LIMIT
2549         V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
2550 #endif
2551 #ifdef IPFIREWALL_NAT
2552         LIST_INIT(&chain->nat);
2553 #endif
2554
2555         /* insert the default rule and create the initial map */
2556         chain->n_rules = 1;
2557         chain->static_len = sizeof(struct ip_fw);
2558         chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_NOWAIT | M_ZERO);
2559         if (chain->map)
2560                 rule = malloc(chain->static_len, M_IPFW, M_NOWAIT | M_ZERO);
2561         if (rule == NULL) {
2562                 if (chain->map)
2563                         free(chain->map, M_IPFW);
2564                 printf("ipfw2: ENOSPC initializing default rule "
2565                         "(support disabled)\n");
2566                 return (ENOSPC);
2567         }
2568         error = ipfw_init_tables(chain);
2569         if (error) {
2570                 panic("init_tables"); /* XXX Marko fix this ! */
2571         }
2572
2573         /* fill and insert the default rule */
2574         rule->act_ofs = 0;
2575         rule->rulenum = IPFW_DEFAULT_RULE;
2576         rule->cmd_len = 1;
2577         rule->set = RESVD_SET;
2578         rule->cmd[0].len = 1;
2579         rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY;
2580         chain->rules = chain->default_rule = chain->map[0] = rule;
2581         chain->id = rule->id = 1;
2582
2583         IPFW_LOCK_INIT(chain);
2584         ipfw_dyn_init();
2585
2586         /* First set up some values that are compile time options */
2587         V_ipfw_vnet_ready = 1;          /* Open for business */
2588
2589         /*
2590          * Hook the sockopt handler, and the layer2 (V_ip_fw_chk_ptr)
2591          * and pfil hooks for ipv4 and ipv6. Even if the latter two fail
2592          * we still keep the module alive because the sockopt and
2593          * layer2 paths are still useful.
2594          * ipfw[6]_hook return 0 on success, ENOENT on failure,
2595          * so we can ignore the exact return value and just set a flag.
2596          *
2597          * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so
2598          * changes in the underlying (per-vnet) variables trigger
2599          * immediate hook()/unhook() calls.
2600          * In layer2 we have the same behaviour, except that V_ether_ipfw
2601          * is checked on each packet because there are no pfil hooks.
2602          */
2603         V_ip_fw_ctl_ptr = ipfw_ctl;
2604         V_ip_fw_chk_ptr = ipfw_chk;
2605         error = ipfw_attach_hooks(1);
2606         return (error);
2607 }
2608
2609 /*
2610  * Called for the removal of each instance.
2611  */
2612 static int
2613 vnet_ipfw_uninit(const void *unused)
2614 {
2615         struct ip_fw *reap, *rule;
2616         struct ip_fw_chain *chain = &V_layer3_chain;
2617         int i;
2618
2619         V_ipfw_vnet_ready = 0; /* tell new callers to go away */
2620         /*
2621          * disconnect from ipv4, ipv6, layer2 and sockopt.
2622          * Then grab, release and grab again the WLOCK so we make
2623          * sure the update is propagated and nobody will be in.
2624          */
2625         (void)ipfw_attach_hooks(0 /* detach */);
2626         V_ip_fw_chk_ptr = NULL;
2627         V_ip_fw_ctl_ptr = NULL;
2628         IPFW_UH_WLOCK(chain);
2629         IPFW_UH_WUNLOCK(chain);
2630         IPFW_UH_WLOCK(chain);
2631
2632         IPFW_WLOCK(chain);
2633         IPFW_WUNLOCK(chain);
2634         IPFW_WLOCK(chain);
2635
2636         ipfw_dyn_uninit(0);     /* run the callout_drain */
2637         ipfw_destroy_tables(chain);
2638         reap = NULL;
2639         for (i = 0; i < chain->n_rules; i++) {
2640                 rule = chain->map[i];
2641                 rule->x_next = reap;
2642                 reap = rule;
2643         }
2644         if (chain->map)
2645                 free(chain->map, M_IPFW);
2646         IPFW_WUNLOCK(chain);
2647         IPFW_UH_WUNLOCK(chain);
2648         if (reap != NULL)
2649                 ipfw_reap_rules(reap);
2650         IPFW_LOCK_DESTROY(chain);
2651         ipfw_dyn_uninit(1);     /* free the remaining parts */
2652         return 0;
2653 }
2654
2655 /*
2656  * Module event handler.
2657  * In general we have the choice of handling most of these events by the
2658  * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to
2659  * use the SYSINIT handlers as they are more capable of expressing the
2660  * flow of control during module and vnet operations, so this is just
2661  * a skeleton. Note there is no SYSINIT equivalent of the module
2662  * SHUTDOWN handler, but we don't have anything to do in that case anyhow.
2663  */
2664 static int
2665 ipfw_modevent(module_t mod, int type, void *unused)
2666 {
2667         int err = 0;
2668
2669         switch (type) {
2670         case MOD_LOAD:
2671                 /* Called once at module load or
2672                  * system boot if compiled in. */
2673                 break;
2674         case MOD_QUIESCE:
2675                 /* Called before unload. May veto unloading. */
2676                 break;
2677         case MOD_UNLOAD:
2678                 /* Called during unload. */
2679                 break;
2680         case MOD_SHUTDOWN:
2681                 /* Called during system shutdown. */
2682                 break;
2683         default:
2684                 err = EOPNOTSUPP;
2685                 break;
2686         }
2687         return err;
2688 }
2689
2690 static moduledata_t ipfwmod = {
2691         "ipfw",
2692         ipfw_modevent,
2693         0
2694 };
2695
2696 /* Define startup order. */
2697 #define IPFW_SI_SUB_FIREWALL    SI_SUB_PROTO_IFATTACHDOMAIN
2698 #define IPFW_MODEVENT_ORDER     (SI_ORDER_ANY - 255) /* On boot slot in here. */
2699 #define IPFW_MODULE_ORDER       (IPFW_MODEVENT_ORDER + 1) /* A little later. */
2700 #define IPFW_VNET_ORDER         (IPFW_MODEVENT_ORDER + 2) /* Later still. */
2701
2702 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER);
2703 MODULE_VERSION(ipfw, 2);
2704 /* should declare some dependencies here */
2705
2706 /*
2707  * Starting up. Done in order after ipfwmod() has been called.
2708  * VNET_SYSINIT is also called for each existing vnet and each new vnet.
2709  */
2710 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
2711             ipfw_init, NULL);
2712 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
2713             vnet_ipfw_init, NULL);
2714
2715 /*
2716  * Closing up shop. These are done in REVERSE ORDER, but still
2717  * after ipfwmod() has been called. Not called on reboot.
2718  * VNET_SYSUNINIT is also called for each exiting vnet as it exits.
2719  * or when the module is unloaded.
2720  */
2721 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
2722             ipfw_destroy, NULL);
2723 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
2724             vnet_ipfw_uninit, NULL);
2725 /* end of file */