sys/netpfil/ipfw/ip_fw2.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2002-2009 Luigi Rizzo, Universita` di Pisa
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  */
  27
  28 #include <sys/cdefs.h>
  29 __FBSDID("$FreeBSD$");
  30
  31 /*
  32  * The FreeBSD IP packet firewall, main file
  33  */
  34
  35 #include "opt_ipfw.h"
  36 #include "opt_ipdivert.h"
  37 #include "opt_inet.h"
  38 #ifndef INET
  39 #error "IPFIREWALL requires INET"
  40 #endif /* INET */
  41 #include "opt_inet6.h"
  42
  43 #include <sys/param.h>
  44 #include <sys/systm.h>
  45 #include <sys/condvar.h>
  46 #include <sys/counter.h>
  47 #include <sys/eventhandler.h>
  48 #include <sys/malloc.h>
  49 #include <sys/mbuf.h>
  50 #include <sys/kernel.h>
  51 #include <sys/lock.h>
  52 #include <sys/jail.h>
  53 #include <sys/module.h>
  54 #include <sys/priv.h>
  55 #include <sys/proc.h>
  56 #include <sys/rwlock.h>
  57 #include <sys/rmlock.h>
  58 #include <sys/sdt.h>
  59 #include <sys/socket.h>
  60 #include <sys/socketvar.h>
  61 #include <sys/sysctl.h>
  62 #include <sys/syslog.h>
  63 #include <sys/ucred.h>
  64 #include <net/ethernet.h> /* for ETHERTYPE_IP */
  65 #include <net/if.h>
  66 #include <net/if_var.h>
  67 #include <net/route.h>
  68 #include <net/route/nhop.h>
  69 #include <net/pfil.h>
  70 #include <net/vnet.h>
  71
  72 #include <netpfil/pf/pf_mtag.h>
  73
  74 #include <netinet/in.h>
  75 #include <netinet/in_var.h>
  76 #include <netinet/in_pcb.h>
  77 #include <netinet/ip.h>
  78 #include <netinet/ip_var.h>
  79 #include <netinet/ip_icmp.h>
  80 #include <netinet/ip_fw.h>
  81 #include <netinet/ip_carp.h>
  82 #include <netinet/pim.h>
  83 #include <netinet/tcp_var.h>
  84 #include <netinet/udp.h>
  85 #include <netinet/udp_var.h>
  86 #include <netinet/sctp.h>
  87 #include <netinet/sctp_crc32.h>
  88 #include <netinet/sctp_header.h>
  89
  90 #include <netinet/ip6.h>
  91 #include <netinet/icmp6.h>
  92 #include <netinet/in_fib.h>
  93 #ifdef INET6
  94 #include <netinet6/in6_fib.h>
  95 #include <netinet6/in6_pcb.h>
  96 #include <netinet6/scope6_var.h>
  97 #include <netinet6/ip6_var.h>
  98 #endif
  99
 100 #include <net/if_gre.h> /* for struct grehdr */
 101
 102 #include <netpfil/ipfw/ip_fw_private.h>
 103
 104 #include <machine/in_cksum.h>   /* XXX for in_cksum */
 105
 106 #ifdef MAC
 107 #include <security/mac/mac_framework.h>
 108 #endif
 109
 110 #define IPFW_PROBE(probe, arg0, arg1, arg2, arg3, arg4, arg5)           \
 111     SDT_PROBE6(ipfw, , , probe, arg0, arg1, arg2, arg3, arg4, arg5)
 112
 113 SDT_PROVIDER_DEFINE(ipfw);
 114 SDT_PROBE_DEFINE6(ipfw, , , rule__matched,
 115     "int",                      /* retval */
 116     "int",                      /* af */
 117     "void *",                   /* src addr */
 118     "void *",                   /* dst addr */
 119     "struct ip_fw_args *",      /* args */
 120     "struct ip_fw *"            /* rule */);
 121
 122 /*
 123  * static variables followed by global ones.
 124  * All ipfw global variables are here.
 125  */
 126
 127 VNET_DEFINE_STATIC(int, fw_deny_unknown_exthdrs);
 128 #define V_fw_deny_unknown_exthdrs       VNET(fw_deny_unknown_exthdrs)
 129
 130 VNET_DEFINE_STATIC(int, fw_permit_single_frag6) = 1;
 131 #define V_fw_permit_single_frag6        VNET(fw_permit_single_frag6)
 132
 133 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
 134 static int default_to_accept = 1;
 135 #else
 136 static int default_to_accept;
 137 #endif
 138
 139 VNET_DEFINE(int, autoinc_step);
 140 VNET_DEFINE(int, fw_one_pass) = 1;
 141
 142 VNET_DEFINE(unsigned int, fw_tables_max);
 143 VNET_DEFINE(unsigned int, fw_tables_sets) = 0;  /* Don't use set-aware tables */
 144 /* Use 128 tables by default */
 145 static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT;
 146
 147 #ifndef LINEAR_SKIPTO
 148 static int jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num,
 149     int tablearg, int jump_backwards);
 150 #define JUMP(ch, f, num, targ, back)    jump_fast(ch, f, num, targ, back)
 151 #else
 152 static int jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num,
 153     int tablearg, int jump_backwards);
 154 #define JUMP(ch, f, num, targ, back)    jump_linear(ch, f, num, targ, back)
 155 #endif
 156
 157 /*
 158  * Each rule belongs to one of 32 different sets (0..31).
 159  * The variable set_disable contains one bit per set.
 160  * If the bit is set, all rules in the corresponding set
 161  * are disabled. Set RESVD_SET(31) is reserved for the default rule
 162  * and rules that are not deleted by the flush command,
 163  * and CANNOT be disabled.
 164  * Rules in set RESVD_SET can only be deleted individually.
 165  */
 166 VNET_DEFINE(u_int32_t, set_disable);
 167 #define V_set_disable                   VNET(set_disable)
 168
 169 VNET_DEFINE(int, fw_verbose);
 170 /* counter for ipfw_log(NULL...) */
 171 VNET_DEFINE(u_int64_t, norule_counter);
 172 VNET_DEFINE(int, verbose_limit);
 173
 174 /* layer3_chain contains the list of rules for layer 3 */
 175 VNET_DEFINE(struct ip_fw_chain, layer3_chain);
 176
 177 /* ipfw_vnet_ready controls when we are open for business */
 178 VNET_DEFINE(int, ipfw_vnet_ready) = 0;
 179
 180 VNET_DEFINE(int, ipfw_nat_ready) = 0;
 181
 182 ipfw_nat_t *ipfw_nat_ptr = NULL;
 183 struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int);
 184 ipfw_nat_cfg_t *ipfw_nat_cfg_ptr;
 185 ipfw_nat_cfg_t *ipfw_nat_del_ptr;
 186 ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr;
 187 ipfw_nat_cfg_t *ipfw_nat_get_log_ptr;
 188
 189 #ifdef SYSCTL_NODE
 190 uint32_t dummy_def = IPFW_DEFAULT_RULE;
 191 static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS);
 192 static int sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS);
 193
 194 SYSBEGIN(f3)
 195
 196 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
 197     "Firewall");
 198 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass,
 199     CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0,
 200     "Only do a single pass through ipfw when using dummynet(4)");
 201 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step,
 202     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(autoinc_step), 0,
 203     "Rule number auto-increment step");
 204 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose,
 205     CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0,
 206     "Log matches to ipfw rules");
 207 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit,
 208     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(verbose_limit), 0,
 209     "Set upper limit of matches of ipfw rules logged");
 210 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD,
 211     &dummy_def, 0,
 212     "The default/max possible rule number.");
 213 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_max,
 214     CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
 215     0, 0, sysctl_ipfw_table_num, "IU",
 216     "Maximum number of concurrently used tables");
 217 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_sets,
 218     CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
 219     0, 0, sysctl_ipfw_tables_sets, "IU",
 220     "Use per-set namespace for tables");
 221 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN,
 222     &default_to_accept, 0,
 223     "Make the default rule accept all packets.");
 224 TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables);
 225 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count,
 226     CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0,
 227     "Number of static rules");
 228
 229 #ifdef INET6
 230 SYSCTL_DECL(_net_inet6_ip6);
 231 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
 232     "Firewall");
 233 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs,
 234     CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE,
 235     &VNET_NAME(fw_deny_unknown_exthdrs), 0,
 236     "Deny packets with unknown IPv6 Extension Headers");
 237 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6,
 238     CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE,
 239     &VNET_NAME(fw_permit_single_frag6), 0,
 240     "Permit single packet IPv6 fragments");
 241 #endif /* INET6 */
 242
 243 SYSEND
 244
 245 #endif /* SYSCTL_NODE */
 246
 247 /*
 248  * Some macros used in the various matching options.
 249  * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T
 250  * Other macros just cast void * into the appropriate type
 251  */
 252 #define L3HDR(T, ip)    ((T *)((u_int32_t *)(ip) + (ip)->ip_hl))
 253 #define TCP(p)          ((struct tcphdr *)(p))
 254 #define SCTP(p)         ((struct sctphdr *)(p))
 255 #define UDP(p)          ((struct udphdr *)(p))
 256 #define ICMP(p)         ((struct icmphdr *)(p))
 257 #define ICMP6(p)        ((struct icmp6_hdr *)(p))
 258
 259 static __inline int
 260 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd)
 261 {
 262         int type = icmp->icmp_type;
 263
 264         return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) );
 265 }
 266
 267 #define TT      ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \
 268     (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) )
 269
 270 static int
 271 is_icmp_query(struct icmphdr *icmp)
 272 {
 273         int type = icmp->icmp_type;
 274
 275         return (type <= ICMP_MAXTYPE && (TT & (1<<type)) );
 276 }
 277 #undef TT
 278
 279 /*
 280  * The following checks use two arrays of 8 or 16 bits to store the
 281  * bits that we want set or clear, respectively. They are in the
 282  * low and high half of cmd->arg1 or cmd->d[0].
 283  *
 284  * We scan options and store the bits we find set. We succeed if
 285  *
 286  *      (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear
 287  *
 288  * The code is sometimes optimized not to store additional variables.
 289  */
 290
 291 static int
 292 flags_match(ipfw_insn *cmd, u_int8_t bits)
 293 {
 294         u_char want_clear;
 295         bits = ~bits;
 296
 297         if ( ((cmd->arg1 & 0xff) & bits) != 0)
 298                 return 0; /* some bits we want set were clear */
 299         want_clear = (cmd->arg1 >> 8) & 0xff;
 300         if ( (want_clear & bits) != want_clear)
 301                 return 0; /* some bits we want clear were set */
 302         return 1;
 303 }
 304
 305 static int
 306 ipopts_match(struct ip *ip, ipfw_insn *cmd)
 307 {
 308         int optlen, bits = 0;
 309         u_char *cp = (u_char *)(ip + 1);
 310         int x = (ip->ip_hl << 2) - sizeof (struct ip);
 311
 312         for (; x > 0; x -= optlen, cp += optlen) {
 313                 int opt = cp[IPOPT_OPTVAL];
 314
 315                 if (opt == IPOPT_EOL)
 316                         break;
 317                 if (opt == IPOPT_NOP)
 318                         optlen = 1;
 319                 else {
 320                         optlen = cp[IPOPT_OLEN];
 321                         if (optlen <= 0 || optlen > x)
 322                                 return 0; /* invalid or truncated */
 323                 }
 324                 switch (opt) {
 325                 default:
 326                         break;
 327
 328                 case IPOPT_LSRR:
 329                         bits |= IP_FW_IPOPT_LSRR;
 330                         break;
 331
 332                 case IPOPT_SSRR:
 333                         bits |= IP_FW_IPOPT_SSRR;
 334                         break;
 335
 336                 case IPOPT_RR:
 337                         bits |= IP_FW_IPOPT_RR;
 338                         break;
 339
 340                 case IPOPT_TS:
 341                         bits |= IP_FW_IPOPT_TS;
 342                         break;
 343                 }
 344         }
 345         return (flags_match(cmd, bits));
 346 }
 347
 348 /*
 349  * Parse TCP options. The logic copied from tcp_dooptions().
 350  */
 351 static int
 352 tcpopts_parse(const struct tcphdr *tcp, uint16_t *mss)
 353 {
 354         const u_char *cp = (const u_char *)(tcp + 1);
 355         int optlen, bits = 0;
 356         int cnt = (tcp->th_off << 2) - sizeof(struct tcphdr);
 357
 358         for (; cnt > 0; cnt -= optlen, cp += optlen) {
 359                 int opt = cp[0];
 360                 if (opt == TCPOPT_EOL)
 361                         break;
 362                 if (opt == TCPOPT_NOP)
 363                         optlen = 1;
 364                 else {
 365                         if (cnt < 2)
 366                                 break;
 367                         optlen = cp[1];
 368                         if (optlen < 2 || optlen > cnt)
 369                                 break;
 370                 }
 371
 372                 switch (opt) {
 373                 default:
 374                         break;
 375
 376                 case TCPOPT_MAXSEG:
 377                         if (optlen != TCPOLEN_MAXSEG)
 378                                 break;
 379                         bits |= IP_FW_TCPOPT_MSS;
 380                         if (mss != NULL)
 381                                 *mss = be16dec(cp + 2);
 382                         break;
 383
 384                 case TCPOPT_WINDOW:
 385                         if (optlen == TCPOLEN_WINDOW)
 386                                 bits |= IP_FW_TCPOPT_WINDOW;
 387                         break;
 388
 389                 case TCPOPT_SACK_PERMITTED:
 390                         if (optlen == TCPOLEN_SACK_PERMITTED)
 391                                 bits |= IP_FW_TCPOPT_SACK;
 392                         break;
 393
 394                 case TCPOPT_SACK:
 395                         if (optlen > 2 && (optlen - 2) % TCPOLEN_SACK == 0)
 396                                 bits |= IP_FW_TCPOPT_SACK;
 397                         break;
 398
 399                 case TCPOPT_TIMESTAMP:
 400                         if (optlen == TCPOLEN_TIMESTAMP)
 401                                 bits |= IP_FW_TCPOPT_TS;
 402                         break;
 403                 }
 404         }
 405         return (bits);
 406 }
 407
 408 static int
 409 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd)
 410 {
 411
 412         return (flags_match(cmd, tcpopts_parse(tcp, NULL)));
 413 }
 414
 415 static int
 416 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain,
 417     uint32_t *tablearg)
 418 {
 419
 420         if (ifp == NULL)        /* no iface with this packet, match fails */
 421                 return (0);
 422
 423         /* Check by name or by IP address */
 424         if (cmd->name[0] != '\0') { /* match by name */
 425                 if (cmd->name[0] == '\1') /* use tablearg to match */
 426                         return ipfw_lookup_table(chain, cmd->p.kidx, 0,
 427                             &ifp->if_index, tablearg);
 428                 /* Check name */
 429                 if (cmd->p.glob) {
 430                         if (fnmatch(cmd->name, ifp->if_xname, 0) == 0)
 431                                 return(1);
 432                 } else {
 433                         if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0)
 434                                 return(1);
 435                 }
 436         } else {
 437 #if !defined(USERSPACE) && defined(__FreeBSD__) /* and OSX too ? */
 438                 struct ifaddr *ia;
 439
 440                 NET_EPOCH_ASSERT();
 441
 442                 CK_STAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
 443                         if (ia->ifa_addr->sa_family != AF_INET)
 444                                 continue;
 445                         if (cmd->p.ip.s_addr == ((struct sockaddr_in *)
 446                             (ia->ifa_addr))->sin_addr.s_addr)
 447                                 return (1);     /* match */
 448                 }
 449 #endif /* __FreeBSD__ */
 450         }
 451         return(0);      /* no match, fail ... */
 452 }
 453
 454 /*
 455  * The verify_path function checks if a route to the src exists and
 456  * if it is reachable via ifp (when provided).
 457  *
 458  * The 'verrevpath' option checks that the interface that an IP packet
 459  * arrives on is the same interface that traffic destined for the
 460  * packet's source address would be routed out of.
 461  * The 'versrcreach' option just checks that the source address is
 462  * reachable via any route (except default) in the routing table.
 463  * These two are a measure to block forged packets. This is also
 464  * commonly known as "anti-spoofing" or Unicast Reverse Path
 465  * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs
 466  * is purposely reminiscent of the Cisco IOS command,
 467  *
 468  *   ip verify unicast reverse-path
 469  *   ip verify unicast source reachable-via any
 470  *
 471  * which implements the same functionality. But note that the syntax
 472  * is misleading, and the check may be performed on all IP packets
 473  * whether unicast, multicast, or broadcast.
 474  */
 475 static int
 476 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib)
 477 {
 478 #if defined(USERSPACE) || !defined(__FreeBSD__)
 479         return 0;
 480 #else
 481         struct nhop_object *nh;
 482
 483         nh = fib4_lookup(fib, src, 0, NHR_NONE, 0);
 484         if (nh == NULL)
 485                 return (0);
 486
 487         /*
 488          * If ifp is provided, check for equality with rtentry.
 489          * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
 490          * in order to pass packets injected back by if_simloop():
 491          * routing entry (via lo0) for our own address
 492          * may exist, so we need to handle routing assymetry.
 493          */
 494         if (ifp != NULL && ifp != nh->nh_aifp)
 495                 return (0);
 496
 497         /* if no ifp provided, check if rtentry is not default route */
 498         if (ifp == NULL && (nh->nh_flags & NHF_DEFAULT) != 0)
 499                 return (0);
 500
 501         /* or if this is a blackhole/reject route */
 502         if (ifp == NULL && (nh->nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0)
 503                 return (0);
 504
 505         /* found valid route */
 506         return 1;
 507 #endif /* __FreeBSD__ */
 508 }
 509
 510 /*
 511  * Generate an SCTP packet containing an ABORT chunk. The verification tag
 512  * is given by vtag. The T-bit is set in the ABORT chunk if and only if
 513  * reflected is not 0.
 514  */
 515
 516 static struct mbuf *
 517 ipfw_send_abort(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t vtag,
 518     int reflected)
 519 {
 520         struct mbuf *m;
 521         struct ip *ip;
 522 #ifdef INET6
 523         struct ip6_hdr *ip6;
 524 #endif
 525         struct sctphdr *sctp;
 526         struct sctp_chunkhdr *chunk;
 527         u_int16_t hlen, plen, tlen;
 528
 529         MGETHDR(m, M_NOWAIT, MT_DATA);
 530         if (m == NULL)
 531                 return (NULL);
 532
 533         M_SETFIB(m, id->fib);
 534 #ifdef MAC
 535         if (replyto != NULL)
 536                 mac_netinet_firewall_reply(replyto, m);
 537         else
 538                 mac_netinet_firewall_send(m);
 539 #else
 540         (void)replyto;          /* don't warn about unused arg */
 541 #endif
 542
 543         switch (id->addr_type) {
 544         case 4:
 545                 hlen = sizeof(struct ip);
 546                 break;
 547 #ifdef INET6
 548         case 6:
 549                 hlen = sizeof(struct ip6_hdr);
 550                 break;
 551 #endif
 552         default:
 553                 /* XXX: log me?!? */
 554                 FREE_PKT(m);
 555                 return (NULL);
 556         }
 557         plen = sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr);
 558         tlen = hlen + plen;
 559         m->m_data += max_linkhdr;
 560         m->m_flags |= M_SKIP_FIREWALL;
 561         m->m_pkthdr.len = m->m_len = tlen;
 562         m->m_pkthdr.rcvif = NULL;
 563         bzero(m->m_data, tlen);
 564
 565         switch (id->addr_type) {
 566         case 4:
 567                 ip = mtod(m, struct ip *);
 568
 569                 ip->ip_v = 4;
 570                 ip->ip_hl = sizeof(struct ip) >> 2;
 571                 ip->ip_tos = IPTOS_LOWDELAY;
 572                 ip->ip_len = htons(tlen);
 573                 ip->ip_id = htons(0);
 574                 ip->ip_off = htons(0);
 575                 ip->ip_ttl = V_ip_defttl;
 576                 ip->ip_p = IPPROTO_SCTP;
 577                 ip->ip_sum = 0;
 578                 ip->ip_src.s_addr = htonl(id->dst_ip);
 579                 ip->ip_dst.s_addr = htonl(id->src_ip);
 580
 581                 sctp = (struct sctphdr *)(ip + 1);
 582                 break;
 583 #ifdef INET6
 584         case 6:
 585                 ip6 = mtod(m, struct ip6_hdr *);
 586
 587                 ip6->ip6_vfc = IPV6_VERSION;
 588                 ip6->ip6_plen = htons(plen);
 589                 ip6->ip6_nxt = IPPROTO_SCTP;
 590                 ip6->ip6_hlim = IPV6_DEFHLIM;
 591                 ip6->ip6_src = id->dst_ip6;
 592                 ip6->ip6_dst = id->src_ip6;
 593
 594                 sctp = (struct sctphdr *)(ip6 + 1);
 595                 break;
 596 #endif
 597         }
 598
 599         sctp->src_port = htons(id->dst_port);
 600         sctp->dest_port = htons(id->src_port);
 601         sctp->v_tag = htonl(vtag);
 602         sctp->checksum = htonl(0);
 603
 604         chunk = (struct sctp_chunkhdr *)(sctp + 1);
 605         chunk->chunk_type = SCTP_ABORT_ASSOCIATION;
 606         chunk->chunk_flags = 0;
 607         if (reflected != 0) {
 608                 chunk->chunk_flags |= SCTP_HAD_NO_TCB;
 609         }
 610         chunk->chunk_length = htons(sizeof(struct sctp_chunkhdr));
 611
 612         sctp->checksum = sctp_calculate_cksum(m, hlen);
 613
 614         return (m);
 615 }
 616
 617 /*
 618  * Generate a TCP packet, containing either a RST or a keepalive.
 619  * When flags & TH_RST, we are sending a RST packet, because of a
 620  * "reset" action matched the packet.
 621  * Otherwise we are sending a keepalive, and flags & TH_
 622  * The 'replyto' mbuf is the mbuf being replied to, if any, and is required
 623  * so that MAC can label the reply appropriately.
 624  */
 625 struct mbuf *
 626 ipfw_send_pkt(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t seq,
 627     u_int32_t ack, int flags)
 628 {
 629         struct mbuf *m = NULL;          /* stupid compiler */
 630         struct ip *h = NULL;            /* stupid compiler */
 631 #ifdef INET6
 632         struct ip6_hdr *h6 = NULL;
 633 #endif
 634         struct tcphdr *th = NULL;
 635         int len, dir;
 636
 637         MGETHDR(m, M_NOWAIT, MT_DATA);
 638         if (m == NULL)
 639                 return (NULL);
 640
 641         M_SETFIB(m, id->fib);
 642 #ifdef MAC
 643         if (replyto != NULL)
 644                 mac_netinet_firewall_reply(replyto, m);
 645         else
 646                 mac_netinet_firewall_send(m);
 647 #else
 648         (void)replyto;          /* don't warn about unused arg */
 649 #endif
 650
 651         switch (id->addr_type) {
 652         case 4:
 653                 len = sizeof(struct ip) + sizeof(struct tcphdr);
 654                 break;
 655 #ifdef INET6
 656         case 6:
 657                 len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
 658                 break;
 659 #endif
 660         default:
 661                 /* XXX: log me?!? */
 662                 FREE_PKT(m);
 663                 return (NULL);
 664         }
 665         dir = ((flags & (TH_SYN | TH_RST)) == TH_SYN);
 666
 667         m->m_data += max_linkhdr;
 668         m->m_flags |= M_SKIP_FIREWALL;
 669         m->m_pkthdr.len = m->m_len = len;
 670         m->m_pkthdr.rcvif = NULL;
 671         bzero(m->m_data, len);
 672
 673         switch (id->addr_type) {
 674         case 4:
 675                 h = mtod(m, struct ip *);
 676
 677                 /* prepare for checksum */
 678                 h->ip_p = IPPROTO_TCP;
 679                 h->ip_len = htons(sizeof(struct tcphdr));
 680                 if (dir) {
 681                         h->ip_src.s_addr = htonl(id->src_ip);
 682                         h->ip_dst.s_addr = htonl(id->dst_ip);
 683                 } else {
 684                         h->ip_src.s_addr = htonl(id->dst_ip);
 685                         h->ip_dst.s_addr = htonl(id->src_ip);
 686                 }
 687
 688                 th = (struct tcphdr *)(h + 1);
 689                 break;
 690 #ifdef INET6
 691         case 6:
 692                 h6 = mtod(m, struct ip6_hdr *);
 693
 694                 /* prepare for checksum */
 695                 h6->ip6_nxt = IPPROTO_TCP;
 696                 h6->ip6_plen = htons(sizeof(struct tcphdr));
 697                 if (dir) {
 698                         h6->ip6_src = id->src_ip6;
 699                         h6->ip6_dst = id->dst_ip6;
 700                 } else {
 701                         h6->ip6_src = id->dst_ip6;
 702                         h6->ip6_dst = id->src_ip6;
 703                 }
 704
 705                 th = (struct tcphdr *)(h6 + 1);
 706                 break;
 707 #endif
 708         }
 709
 710         if (dir) {
 711                 th->th_sport = htons(id->src_port);
 712                 th->th_dport = htons(id->dst_port);
 713         } else {
 714                 th->th_sport = htons(id->dst_port);
 715                 th->th_dport = htons(id->src_port);
 716         }
 717         th->th_off = sizeof(struct tcphdr) >> 2;
 718
 719         if (flags & TH_RST) {
 720                 if (flags & TH_ACK) {
 721                         th->th_seq = htonl(ack);
 722                         th->th_flags = TH_RST;
 723                 } else {
 724                         if (flags & TH_SYN)
 725                                 seq++;
 726                         th->th_ack = htonl(seq);
 727                         th->th_flags = TH_RST | TH_ACK;
 728                 }
 729         } else {
 730                 /*
 731                  * Keepalive - use caller provided sequence numbers
 732                  */
 733                 th->th_seq = htonl(seq);
 734                 th->th_ack = htonl(ack);
 735                 th->th_flags = TH_ACK;
 736         }
 737
 738         switch (id->addr_type) {
 739         case 4:
 740                 th->th_sum = in_cksum(m, len);
 741
 742                 /* finish the ip header */
 743                 h->ip_v = 4;
 744                 h->ip_hl = sizeof(*h) >> 2;
 745                 h->ip_tos = IPTOS_LOWDELAY;
 746                 h->ip_off = htons(0);
 747                 h->ip_len = htons(len);
 748                 h->ip_ttl = V_ip_defttl;
 749                 h->ip_sum = 0;
 750                 break;
 751 #ifdef INET6
 752         case 6:
 753                 th->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(*h6),
 754                     sizeof(struct tcphdr));
 755
 756                 /* finish the ip6 header */
 757                 h6->ip6_vfc |= IPV6_VERSION;
 758                 h6->ip6_hlim = IPV6_DEFHLIM;
 759                 break;
 760 #endif
 761         }
 762
 763         return (m);
 764 }
 765
 766 #ifdef INET6
 767 /*
 768  * ipv6 specific rules here...
 769  */
 770 static __inline int
 771 icmp6type_match(int type, ipfw_insn_u32 *cmd)
 772 {
 773         return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) );
 774 }
 775
 776 static int
 777 flow6id_match(int curr_flow, ipfw_insn_u32 *cmd)
 778 {
 779         int i;
 780         for (i=0; i <= cmd->o.arg1; ++i)
 781                 if (curr_flow == cmd->d[i])
 782                         return 1;
 783         return 0;
 784 }
 785
 786 /* support for IP6_*_ME opcodes */
 787 static const struct in6_addr lla_mask = {{{
 788         0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff,
 789         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
 790 }}};
 791
 792 static int
 793 ipfw_localip6(struct in6_addr *in6)
 794 {
 795         struct rm_priotracker in6_ifa_tracker;
 796         struct in6_ifaddr *ia;
 797
 798         if (IN6_IS_ADDR_MULTICAST(in6))
 799                 return (0);
 800
 801         if (!IN6_IS_ADDR_LINKLOCAL(in6))
 802                 return (in6_localip(in6));
 803
 804         IN6_IFADDR_RLOCK(&in6_ifa_tracker);
 805         CK_STAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) {
 806                 if (!IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr))
 807                         continue;
 808                 if (IN6_ARE_MASKED_ADDR_EQUAL(&ia->ia_addr.sin6_addr,
 809                     in6, &lla_mask)) {
 810                         IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
 811                         return (1);
 812                 }
 813         }
 814         IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
 815         return (0);
 816 }
 817
 818 static int
 819 verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib)
 820 {
 821         struct nhop_object *nh;
 822
 823         if (IN6_IS_SCOPE_LINKLOCAL(src))
 824                 return (1);
 825
 826         nh = fib6_lookup(fib, src, 0, NHR_NONE, 0);
 827         if (nh == NULL)
 828                 return (0);
 829
 830         /* If ifp is provided, check for equality with route table. */
 831         if (ifp != NULL && ifp != nh->nh_aifp)
 832                 return (0);
 833
 834         /* if no ifp provided, check if rtentry is not default route */
 835         if (ifp == NULL && (nh->nh_flags & NHF_DEFAULT) != 0)
 836                 return (0);
 837
 838         /* or if this is a blackhole/reject route */
 839         if (ifp == NULL && (nh->nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0)
 840                 return (0);
 841
 842         /* found valid route */
 843         return 1;
 844 }
 845
 846 static int
 847 is_icmp6_query(int icmp6_type)
 848 {
 849         if ((icmp6_type <= ICMP6_MAXTYPE) &&
 850             (icmp6_type == ICMP6_ECHO_REQUEST ||
 851             icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
 852             icmp6_type == ICMP6_WRUREQUEST ||
 853             icmp6_type == ICMP6_FQDN_QUERY ||
 854             icmp6_type == ICMP6_NI_QUERY))
 855                 return (1);
 856
 857         return (0);
 858 }
 859
 860 static int
 861 map_icmp_unreach(int code)
 862 {
 863
 864         /* RFC 7915 p4.2 */
 865         switch (code) {
 866         case ICMP_UNREACH_NET:
 867         case ICMP_UNREACH_HOST:
 868         case ICMP_UNREACH_SRCFAIL:
 869         case ICMP_UNREACH_NET_UNKNOWN:
 870         case ICMP_UNREACH_HOST_UNKNOWN:
 871         case ICMP_UNREACH_TOSNET:
 872         case ICMP_UNREACH_TOSHOST:
 873                 return (ICMP6_DST_UNREACH_NOROUTE);
 874         case ICMP_UNREACH_PORT:
 875                 return (ICMP6_DST_UNREACH_NOPORT);
 876         default:
 877                 /*
 878                  * Map the rest of codes into admit prohibited.
 879                  * XXX: unreach proto should be mapped into ICMPv6
 880                  * parameter problem, but we use only unreach type.
 881                  */
 882                 return (ICMP6_DST_UNREACH_ADMIN);
 883         }
 884 }
 885
 886 static void
 887 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6)
 888 {
 889         struct mbuf *m;
 890
 891         m = args->m;
 892         if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) {
 893                 struct tcphdr *tcp;
 894                 tcp = (struct tcphdr *)((char *)ip6 + hlen);
 895
 896                 if ((tcp->th_flags & TH_RST) == 0) {
 897                         struct mbuf *m0;
 898                         m0 = ipfw_send_pkt(args->m, &(args->f_id),
 899                             ntohl(tcp->th_seq), ntohl(tcp->th_ack),
 900                             tcp->th_flags | TH_RST);
 901                         if (m0 != NULL)
 902                                 ip6_output(m0, NULL, NULL, 0, NULL, NULL,
 903                                     NULL);
 904                 }
 905                 FREE_PKT(m);
 906         } else if (code == ICMP6_UNREACH_ABORT &&
 907             args->f_id.proto == IPPROTO_SCTP) {
 908                 struct mbuf *m0;
 909                 struct sctphdr *sctp;
 910                 u_int32_t v_tag;
 911                 int reflected;
 912
 913                 sctp = (struct sctphdr *)((char *)ip6 + hlen);
 914                 reflected = 1;
 915                 v_tag = ntohl(sctp->v_tag);
 916                 /* Investigate the first chunk header if available */
 917                 if (m->m_len >= hlen + sizeof(struct sctphdr) +
 918                     sizeof(struct sctp_chunkhdr)) {
 919                         struct sctp_chunkhdr *chunk;
 920
 921                         chunk = (struct sctp_chunkhdr *)(sctp + 1);
 922                         switch (chunk->chunk_type) {
 923                         case SCTP_INITIATION:
 924                                 /*
 925                                  * Packets containing an INIT chunk MUST have
 926                                  * a zero v-tag.
 927                                  */
 928                                 if (v_tag != 0) {
 929                                         v_tag = 0;
 930                                         break;
 931                                 }
 932                                 /* INIT chunk MUST NOT be bundled */
 933                                 if (m->m_pkthdr.len >
 934                                     hlen + sizeof(struct sctphdr) +
 935                                     ntohs(chunk->chunk_length) + 3) {
 936                                         break;
 937                                 }
 938                                 /* Use the initiate tag if available */
 939                                 if ((m->m_len >= hlen + sizeof(struct sctphdr) +
 940                                     sizeof(struct sctp_chunkhdr) +
 941                                     offsetof(struct sctp_init, a_rwnd))) {
 942                                         struct sctp_init *init;
 943
 944                                         init = (struct sctp_init *)(chunk + 1);
 945                                         v_tag = ntohl(init->initiate_tag);
 946                                         reflected = 0;
 947                                 }
 948                                 break;
 949                         case SCTP_ABORT_ASSOCIATION:
 950                                 /*
 951                                  * If the packet contains an ABORT chunk, don't
 952                                  * reply.
 953                                  * XXX: We should search through all chunks,
 954                                  * but do not do that to avoid attacks.
 955                                  */
 956                                 v_tag = 0;
 957                                 break;
 958                         }
 959                 }
 960                 if (v_tag == 0) {
 961                         m0 = NULL;
 962                 } else {
 963                         m0 = ipfw_send_abort(args->m, &(args->f_id), v_tag,
 964                             reflected);
 965                 }
 966                 if (m0 != NULL)
 967                         ip6_output(m0, NULL, NULL, 0, NULL, NULL, NULL);
 968                 FREE_PKT(m);
 969         } else if (code != ICMP6_UNREACH_RST && code != ICMP6_UNREACH_ABORT) {
 970                 /* Send an ICMPv6 unreach. */
 971 #if 0
 972                 /*
 973                  * Unlike above, the mbufs need to line up with the ip6 hdr,
 974                  * as the contents are read. We need to m_adj() the
 975                  * needed amount.
 976                  * The mbuf will however be thrown away so we can adjust it.
 977                  * Remember we did an m_pullup on it already so we
 978                  * can make some assumptions about contiguousness.
 979                  */
 980                 if (args->L3offset)
 981                         m_adj(m, args->L3offset);
 982 #endif
 983                 icmp6_error(m, ICMP6_DST_UNREACH, code, 0);
 984         } else
 985                 FREE_PKT(m);
 986
 987         args->m = NULL;
 988 }
 989
 990 #endif /* INET6 */
 991
 992 /*
 993  * sends a reject message, consuming the mbuf passed as an argument.
 994  */
 995 static void
 996 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip)
 997 {
 998
 999 #if 0
1000         /* XXX When ip is not guaranteed to be at mtod() we will
1001          * need to account for this */
1002          * The mbuf will however be thrown away so we can adjust it.
1003          * Remember we did an m_pullup on it already so we
1004          * can make some assumptions about contiguousness.
1005          */
1006         if (args->L3offset)
1007                 m_adj(m, args->L3offset);
1008 #endif
1009         if (code != ICMP_REJECT_RST && code != ICMP_REJECT_ABORT) {
1010                 /* Send an ICMP unreach */
1011                 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
1012         } else if (code == ICMP_REJECT_RST && args->f_id.proto == IPPROTO_TCP) {
1013                 struct tcphdr *const tcp =
1014                     L3HDR(struct tcphdr, mtod(args->m, struct ip *));
1015                 if ( (tcp->th_flags & TH_RST) == 0) {
1016                         struct mbuf *m;
1017                         m = ipfw_send_pkt(args->m, &(args->f_id),
1018                                 ntohl(tcp->th_seq), ntohl(tcp->th_ack),
1019                                 tcp->th_flags | TH_RST);
1020                         if (m != NULL)
1021                                 ip_output(m, NULL, NULL, 0, NULL, NULL);
1022                 }
1023                 FREE_PKT(args->m);
1024         } else if (code == ICMP_REJECT_ABORT &&
1025             args->f_id.proto == IPPROTO_SCTP) {
1026                 struct mbuf *m;
1027                 struct sctphdr *sctp;
1028                 struct sctp_chunkhdr *chunk;
1029                 struct sctp_init *init;
1030                 u_int32_t v_tag;
1031                 int reflected;
1032
1033                 sctp = L3HDR(struct sctphdr, mtod(args->m, struct ip *));
1034                 reflected = 1;
1035                 v_tag = ntohl(sctp->v_tag);
1036                 if (iplen >= (ip->ip_hl << 2) + sizeof(struct sctphdr) +
1037                     sizeof(struct sctp_chunkhdr)) {
1038                         /* Look at the first chunk header if available */
1039                         chunk = (struct sctp_chunkhdr *)(sctp + 1);
1040                         switch (chunk->chunk_type) {
1041                         case SCTP_INITIATION:
1042                                 /*
1043                                  * Packets containing an INIT chunk MUST have
1044                                  * a zero v-tag.
1045                                  */
1046                                 if (v_tag != 0) {
1047                                         v_tag = 0;
1048                                         break;
1049                                 }
1050                                 /* INIT chunk MUST NOT be bundled */
1051                                 if (iplen >
1052                                     (ip->ip_hl << 2) + sizeof(struct sctphdr) +
1053                                     ntohs(chunk->chunk_length) + 3) {
1054                                         break;
1055                                 }
1056                                 /* Use the initiate tag if available */
1057                                 if ((iplen >= (ip->ip_hl << 2) +
1058                                     sizeof(struct sctphdr) +
1059                                     sizeof(struct sctp_chunkhdr) +
1060                                     offsetof(struct sctp_init, a_rwnd))) {
1061                                         init = (struct sctp_init *)(chunk + 1);
1062                                         v_tag = ntohl(init->initiate_tag);
1063                                         reflected = 0;
1064                                 }
1065                                 break;
1066                         case SCTP_ABORT_ASSOCIATION:
1067                                 /*
1068                                  * If the packet contains an ABORT chunk, don't
1069                                  * reply.
1070                                  * XXX: We should search through all chunks,
1071                                  * but do not do that to avoid attacks.
1072                                  */
1073                                 v_tag = 0;
1074                                 break;
1075                         }
1076                 }
1077                 if (v_tag == 0) {
1078                         m = NULL;
1079                 } else {
1080                         m = ipfw_send_abort(args->m, &(args->f_id), v_tag,
1081                             reflected);
1082                 }
1083                 if (m != NULL)
1084                         ip_output(m, NULL, NULL, 0, NULL, NULL);
1085                 FREE_PKT(args->m);
1086         } else
1087                 FREE_PKT(args->m);
1088         args->m = NULL;
1089 }
1090
1091 /*
1092  * Support for uid/gid/jail lookup. These tests are expensive
1093  * (because we may need to look into the list of active sockets)
1094  * so we cache the results. ugid_lookupp is 0 if we have not
1095  * yet done a lookup, 1 if we succeeded, and -1 if we tried
1096  * and failed. The function always returns the match value.
1097  * We could actually spare the variable and use *uc, setting
1098  * it to '(void *)check_uidgid if we have no info, NULL if
1099  * we tried and failed, or any other value if successful.
1100  */
1101 static int
1102 check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp,
1103     struct ucred **uc)
1104 {
1105 #if defined(USERSPACE)
1106         return 0;       // not supported in userspace
1107 #else
1108 #ifndef __FreeBSD__
1109         /* XXX */
1110         return cred_check(insn, proto, oif,
1111             dst_ip, dst_port, src_ip, src_port,
1112             (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb);
1113 #else  /* FreeBSD */
1114         struct in_addr src_ip, dst_ip;
1115         struct inpcbinfo *pi;
1116         struct ipfw_flow_id *id;
1117         struct inpcb *pcb, *inp;
1118         int lookupflags;
1119         int match;
1120
1121         id = &args->f_id;
1122         inp = args->inp;
1123
1124         /*
1125          * Check to see if the UDP or TCP stack supplied us with
1126          * the PCB. If so, rather then holding a lock and looking
1127          * up the PCB, we can use the one that was supplied.
1128          */
1129         if (inp && *ugid_lookupp == 0) {
1130                 INP_LOCK_ASSERT(inp);
1131                 if (inp->inp_socket != NULL) {
1132                         *uc = crhold(inp->inp_cred);
1133                         *ugid_lookupp = 1;
1134                 } else
1135                         *ugid_lookupp = -1;
1136         }
1137         /*
1138          * If we have already been here and the packet has no
1139          * PCB entry associated with it, then we can safely
1140          * assume that this is a no match.
1141          */
1142         if (*ugid_lookupp == -1)
1143                 return (0);
1144         if (id->proto == IPPROTO_TCP) {
1145                 lookupflags = 0;
1146                 pi = &V_tcbinfo;
1147         } else if (id->proto == IPPROTO_UDP) {
1148                 lookupflags = INPLOOKUP_WILDCARD;
1149                 pi = &V_udbinfo;
1150         } else if (id->proto == IPPROTO_UDPLITE) {
1151                 lookupflags = INPLOOKUP_WILDCARD;
1152                 pi = &V_ulitecbinfo;
1153         } else
1154                 return 0;
1155         lookupflags |= INPLOOKUP_RLOCKPCB;
1156         match = 0;
1157         if (*ugid_lookupp == 0) {
1158                 if (id->addr_type == 6) {
1159 #ifdef INET6
1160                         if (args->flags & IPFW_ARGS_IN)
1161                                 pcb = in6_pcblookup_mbuf(pi,
1162                                     &id->src_ip6, htons(id->src_port),
1163                                     &id->dst_ip6, htons(id->dst_port),
1164                                     lookupflags, NULL, args->m);
1165                         else
1166                                 pcb = in6_pcblookup_mbuf(pi,
1167                                     &id->dst_ip6, htons(id->dst_port),
1168                                     &id->src_ip6, htons(id->src_port),
1169                                     lookupflags, args->ifp, args->m);
1170 #else
1171                         *ugid_lookupp = -1;
1172                         return (0);
1173 #endif
1174                 } else {
1175                         src_ip.s_addr = htonl(id->src_ip);
1176                         dst_ip.s_addr = htonl(id->dst_ip);
1177                         if (args->flags & IPFW_ARGS_IN)
1178                                 pcb = in_pcblookup_mbuf(pi,
1179                                     src_ip, htons(id->src_port),
1180                                     dst_ip, htons(id->dst_port),
1181                                     lookupflags, NULL, args->m);
1182                         else
1183                                 pcb = in_pcblookup_mbuf(pi,
1184                                     dst_ip, htons(id->dst_port),
1185                                     src_ip, htons(id->src_port),
1186                                     lookupflags, args->ifp, args->m);
1187                 }
1188                 if (pcb != NULL) {
1189                         INP_RLOCK_ASSERT(pcb);
1190                         *uc = crhold(pcb->inp_cred);
1191                         *ugid_lookupp = 1;
1192                         INP_RUNLOCK(pcb);
1193                 }
1194                 if (*ugid_lookupp == 0) {
1195                         /*
1196                          * We tried and failed, set the variable to -1
1197                          * so we will not try again on this packet.
1198                          */
1199                         *ugid_lookupp = -1;
1200                         return (0);
1201                 }
1202         }
1203         if (insn->o.opcode == O_UID)
1204                 match = ((*uc)->cr_uid == (uid_t)insn->d[0]);
1205         else if (insn->o.opcode == O_GID)
1206                 match = groupmember((gid_t)insn->d[0], *uc);
1207         else if (insn->o.opcode == O_JAIL)
1208                 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]);
1209         return (match);
1210 #endif /* __FreeBSD__ */
1211 #endif /* not supported in userspace */
1212 }
1213
1214 /*
1215  * Helper function to set args with info on the rule after the matching
1216  * one. slot is precise, whereas we guess rule_id as they are
1217  * assigned sequentially.
1218  */
1219 static inline void
1220 set_match(struct ip_fw_args *args, int slot,
1221         struct ip_fw_chain *chain)
1222 {
1223         args->rule.chain_id = chain->id;
1224         args->rule.slot = slot + 1; /* we use 0 as a marker */
1225         args->rule.rule_id = 1 + chain->map[slot]->id;
1226         args->rule.rulenum = chain->map[slot]->rulenum;
1227         args->flags |= IPFW_ARGS_REF;
1228 }
1229
1230 #ifndef LINEAR_SKIPTO
1231 /*
1232  * Helper function to enable cached rule lookups using
1233  * cached_id and cached_pos fields in ipfw rule.
1234  */
1235 static int
1236 jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num,
1237     int tablearg, int jump_backwards)
1238 {
1239         int f_pos;
1240
1241         /* If possible use cached f_pos (in f->cached_pos),
1242          * whose version is written in f->cached_id
1243          * (horrible hacks to avoid changing the ABI).
1244          */
1245         if (num != IP_FW_TARG && f->cached_id == chain->id)
1246                 f_pos = f->cached_pos;
1247         else {
1248                 int i = IP_FW_ARG_TABLEARG(chain, num, skipto);
1249                 /* make sure we do not jump backward */
1250                 if (jump_backwards == 0 && i <= f->rulenum)
1251                         i = f->rulenum + 1;
1252                 if (chain->idxmap != NULL)
1253                         f_pos = chain->idxmap[i];
1254                 else
1255                         f_pos = ipfw_find_rule(chain, i, 0);
1256                 /* update the cache */
1257                 if (num != IP_FW_TARG) {
1258                         f->cached_id = chain->id;
1259                         f->cached_pos = f_pos;
1260                 }
1261         }
1262
1263         return (f_pos);
1264 }
1265 #else
1266 /*
1267  * Helper function to enable real fast rule lookups.
1268  */
1269 static int
1270 jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num,
1271     int tablearg, int jump_backwards)
1272 {
1273         int f_pos;
1274
1275         num = IP_FW_ARG_TABLEARG(chain, num, skipto);
1276         /* make sure we do not jump backward */
1277         if (jump_backwards == 0 && num <= f->rulenum)
1278                 num = f->rulenum + 1;
1279         f_pos = chain->idxmap[num];
1280
1281         return (f_pos);
1282 }
1283 #endif
1284
1285 #define TARG(k, f)      IP_FW_ARG_TABLEARG(chain, k, f)
1286 /*
1287  * The main check routine for the firewall.
1288  *
1289  * All arguments are in args so we can modify them and return them
1290  * back to the caller.
1291  *
1292  * Parameters:
1293  *
1294  *      args->m (in/out) The packet; we set to NULL when/if we nuke it.
1295  *              Starts with the IP header.
1296  *      args->L3offset  Number of bytes bypassed if we came from L2.
1297  *                      e.g. often sizeof(eh)  ** NOTYET **
1298  *      args->ifp       Incoming or outgoing interface.
1299  *      args->divert_rule (in/out)
1300  *              Skip up to the first rule past this rule number;
1301  *              upon return, non-zero port number for divert or tee.
1302  *
1303  *      args->rule      Pointer to the last matching rule (in/out)
1304  *      args->next_hop  Socket we are forwarding to (out).
1305  *      args->next_hop6 IPv6 next hop we are forwarding to (out).
1306  *      args->f_id      Addresses grabbed from the packet (out)
1307  *      args->rule.info a cookie depending on rule action
1308  *
1309  * Return value:
1310  *
1311  *      IP_FW_PASS      the packet must be accepted
1312  *      IP_FW_DENY      the packet must be dropped
1313  *      IP_FW_DIVERT    divert packet, port in m_tag
1314  *      IP_FW_TEE       tee packet, port in m_tag
1315  *      IP_FW_DUMMYNET  to dummynet, pipe in args->cookie
1316  *      IP_FW_NETGRAPH  into netgraph, cookie args->cookie
1317  *              args->rule contains the matching rule,
1318  *              args->rule.info has additional information.
1319  *
1320  */
1321 int
1322 ipfw_chk(struct ip_fw_args *args)
1323 {
1324
1325         /*
1326          * Local variables holding state while processing a packet:
1327          *
1328          * IMPORTANT NOTE: to speed up the processing of rules, there
1329          * are some assumption on the values of the variables, which
1330          * are documented here. Should you change them, please check
1331          * the implementation of the various instructions to make sure
1332          * that they still work.
1333          *
1334          * m | args->m  Pointer to the mbuf, as received from the caller.
1335          *      It may change if ipfw_chk() does an m_pullup, or if it
1336          *      consumes the packet because it calls send_reject().
1337          *      XXX This has to change, so that ipfw_chk() never modifies
1338          *      or consumes the buffer.
1339          *      OR
1340          * args->mem    Pointer to contigous memory chunk.
1341          * ip   Is the beginning of the ip(4 or 6) header.
1342          * eh   Ethernet header in case if input is Layer2.
1343          */
1344         struct mbuf *m;
1345         struct ip *ip;
1346         struct ether_header *eh;
1347
1348         /*
1349          * For rules which contain uid/gid or jail constraints, cache
1350          * a copy of the users credentials after the pcb lookup has been
1351          * executed. This will speed up the processing of rules with
1352          * these types of constraints, as well as decrease contention
1353          * on pcb related locks.
1354          */
1355 #ifndef __FreeBSD__
1356         struct bsd_ucred ucred_cache;
1357 #else
1358         struct ucred *ucred_cache = NULL;
1359 #endif
1360         int ucred_lookup = 0;
1361         int f_pos = 0;          /* index of current rule in the array */
1362         int retval = 0;
1363         struct ifnet *oif, *iif;
1364
1365         /*
1366          * hlen The length of the IP header.
1367          */
1368         u_int hlen = 0;         /* hlen >0 means we have an IP pkt */
1369
1370         /*
1371          * offset       The offset of a fragment. offset != 0 means that
1372          *      we have a fragment at this offset of an IPv4 packet.
1373          *      offset == 0 means that (if this is an IPv4 packet)
1374          *      this is the first or only fragment.
1375          *      For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header
1376          *      or there is a single packet fragment (fragment header added
1377          *      without needed).  We will treat a single packet fragment as if
1378          *      there was no fragment header (or log/block depending on the
1379          *      V_fw_permit_single_frag6 sysctl setting).
1380          */
1381         u_short offset = 0;
1382         u_short ip6f_mf = 0;
1383
1384         /*
1385          * Local copies of addresses. They are only valid if we have
1386          * an IP packet.
1387          *
1388          * proto        The protocol. Set to 0 for non-ip packets,
1389          *      or to the protocol read from the packet otherwise.
1390          *      proto != 0 means that we have an IPv4 packet.
1391          *
1392          * src_port, dst_port   port numbers, in HOST format. Only
1393          *      valid for TCP and UDP packets.
1394          *
1395          * src_ip, dst_ip       ip addresses, in NETWORK format.
1396          *      Only valid for IPv4 packets.
1397          */
1398         uint8_t proto;
1399         uint16_t src_port, dst_port;            /* NOTE: host format    */
1400         struct in_addr src_ip, dst_ip;          /* NOTE: network format */
1401         int iplen = 0;
1402         int pktlen;
1403
1404         struct ipfw_dyn_info dyn_info;
1405         struct ip_fw *q = NULL;
1406         struct ip_fw_chain *chain = &V_layer3_chain;
1407
1408         /*
1409          * We store in ulp a pointer to the upper layer protocol header.
1410          * In the ipv4 case this is easy to determine from the header,
1411          * but for ipv6 we might have some additional headers in the middle.
1412          * ulp is NULL if not found.
1413          */
1414         void *ulp = NULL;               /* upper layer protocol pointer. */
1415
1416         /* XXX ipv6 variables */
1417         int is_ipv6 = 0;
1418         uint8_t icmp6_type = 0;
1419         uint16_t ext_hd = 0;    /* bits vector for extension header filtering */
1420         /* end of ipv6 variables */
1421
1422         int is_ipv4 = 0;
1423
1424         int done = 0;           /* flag to exit the outer loop */
1425         IPFW_RLOCK_TRACKER;
1426         bool mem;
1427
1428         if ((mem = (args->flags & IPFW_ARGS_LENMASK))) {
1429                 if (args->flags & IPFW_ARGS_ETHER) {
1430                         eh = (struct ether_header *)args->mem;
1431                         if (eh->ether_type == htons(ETHERTYPE_VLAN))
1432                                 ip = (struct ip *)
1433                                     ((struct ether_vlan_header *)eh + 1);
1434                         else
1435                                 ip = (struct ip *)(eh + 1);
1436                 } else {
1437                         eh = NULL;
1438                         ip = (struct ip *)args->mem;
1439                 }
1440                 pktlen = IPFW_ARGS_LENGTH(args->flags);
1441                 args->f_id.fib = args->ifp->if_fib;     /* best guess */
1442         } else {
1443                 m = args->m;
1444                 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready))
1445                         return (IP_FW_PASS);    /* accept */
1446                 if (args->flags & IPFW_ARGS_ETHER) {
1447                         /* We need some amount of data to be contiguous. */
1448                         if (m->m_len < min(m->m_pkthdr.len, max_protohdr) &&
1449                             (args->m = m = m_pullup(m, min(m->m_pkthdr.len,
1450                             max_protohdr))) == NULL)
1451                                 goto pullup_failed;
1452                         eh = mtod(m, struct ether_header *);
1453                         ip = (struct ip *)(eh + 1);
1454                 } else {
1455                         eh = NULL;
1456                         ip = mtod(m, struct ip *);
1457                 }
1458                 pktlen = m->m_pkthdr.len;
1459                 args->f_id.fib = M_GETFIB(m); /* mbuf not altered */
1460         }
1461
1462         dst_ip.s_addr = 0;              /* make sure it is initialized */
1463         src_ip.s_addr = 0;              /* make sure it is initialized */
1464         src_port = dst_port = 0;
1465
1466         DYN_INFO_INIT(&dyn_info);
1467 /*
1468  * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous,
1469  * then it sets p to point at the offset "len" in the mbuf. WARNING: the
1470  * pointer might become stale after other pullups (but we never use it
1471  * this way).
1472  */
1473 #define PULLUP_TO(_len, p, T)   PULLUP_LEN(_len, p, sizeof(T))
1474 #define EHLEN   (eh != NULL ? ((char *)ip - (char *)eh) : 0)
1475 #define _PULLUP_LOCKED(_len, p, T, unlock)                      \
1476 do {                                                            \
1477         int x = (_len) + T + EHLEN;                             \
1478         if (mem) {                                              \
1479                 if (__predict_false(pktlen < x)) {              \
1480                         unlock;                                 \
1481                         goto pullup_failed;                     \
1482                 }                                               \
1483                 p = (char *)args->mem + (_len) + EHLEN;         \
1484         } else {                                                \
1485                 if (__predict_false((m)->m_len < x)) {          \
1486                         args->m = m = m_pullup(m, x);           \
1487                         if (m == NULL) {                        \
1488                                 unlock;                         \
1489                                 goto pullup_failed;             \
1490                         }                                       \
1491                 }                                               \
1492                 p = mtod(m, char *) + (_len) + EHLEN;           \
1493         }                                                       \
1494 } while (0)
1495
1496 #define PULLUP_LEN(_len, p, T)  _PULLUP_LOCKED(_len, p, T, )
1497 #define PULLUP_LEN_LOCKED(_len, p, T)   \
1498     _PULLUP_LOCKED(_len, p, T, IPFW_PF_RUNLOCK(chain)); \
1499     UPDATE_POINTERS()
1500 /*
1501  * In case pointers got stale after pullups, update them.
1502  */
1503 #define UPDATE_POINTERS()                                       \
1504 do {                                                            \
1505         if (!mem) {                                             \
1506                 if (eh != NULL) {                               \
1507                         eh = mtod(m, struct ether_header *);    \
1508                         ip = (struct ip *)(eh + 1);             \
1509                 } else                                          \
1510                         ip = mtod(m, struct ip *);              \
1511                 args->m = m;                                    \
1512         }                                                       \
1513 } while (0)
1514
1515         /* Identify IP packets and fill up variables. */
1516         if (pktlen >= sizeof(struct ip6_hdr) &&
1517             (eh == NULL || eh->ether_type == htons(ETHERTYPE_IPV6)) &&
1518             ip->ip_v == 6) {
1519                 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip;
1520
1521                 is_ipv6 = 1;
1522                 args->flags |= IPFW_ARGS_IP6;
1523                 hlen = sizeof(struct ip6_hdr);
1524                 proto = ip6->ip6_nxt;
1525                 /* Search extension headers to find upper layer protocols */
1526                 while (ulp == NULL && offset == 0) {
1527                         switch (proto) {
1528                         case IPPROTO_ICMPV6:
1529                                 PULLUP_TO(hlen, ulp, struct icmp6_hdr);
1530                                 icmp6_type = ICMP6(ulp)->icmp6_type;
1531                                 break;
1532
1533                         case IPPROTO_TCP:
1534                                 PULLUP_TO(hlen, ulp, struct tcphdr);
1535                                 dst_port = TCP(ulp)->th_dport;
1536                                 src_port = TCP(ulp)->th_sport;
1537                                 /* save flags for dynamic rules */
1538                                 args->f_id._flags = TCP(ulp)->th_flags;
1539                                 break;
1540
1541                         case IPPROTO_SCTP:
1542                                 if (pktlen >= hlen + sizeof(struct sctphdr) +
1543                                     sizeof(struct sctp_chunkhdr) +
1544                                     offsetof(struct sctp_init, a_rwnd))
1545                                         PULLUP_LEN(hlen, ulp,
1546                                             sizeof(struct sctphdr) +
1547                                             sizeof(struct sctp_chunkhdr) +
1548                                             offsetof(struct sctp_init, a_rwnd));
1549                                 else if (pktlen >= hlen + sizeof(struct sctphdr))
1550                                         PULLUP_LEN(hlen, ulp, pktlen - hlen);
1551                                 else
1552                                         PULLUP_LEN(hlen, ulp,
1553                                             sizeof(struct sctphdr));
1554                                 src_port = SCTP(ulp)->src_port;
1555                                 dst_port = SCTP(ulp)->dest_port;
1556                                 break;
1557
1558                         case IPPROTO_UDP:
1559                         case IPPROTO_UDPLITE:
1560                                 PULLUP_TO(hlen, ulp, struct udphdr);
1561                                 dst_port = UDP(ulp)->uh_dport;
1562                                 src_port = UDP(ulp)->uh_sport;
1563                                 break;
1564
1565                         case IPPROTO_HOPOPTS:   /* RFC 2460 */
1566                                 PULLUP_TO(hlen, ulp, struct ip6_hbh);
1567                                 ext_hd |= EXT_HOPOPTS;
1568                                 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
1569                                 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
1570                                 ulp = NULL;
1571                                 break;
1572
1573                         case IPPROTO_ROUTING:   /* RFC 2460 */
1574                                 PULLUP_TO(hlen, ulp, struct ip6_rthdr);
1575                                 switch (((struct ip6_rthdr *)ulp)->ip6r_type) {
1576                                 case 0:
1577                                         ext_hd |= EXT_RTHDR0;
1578                                         break;
1579                                 case 2:
1580                                         ext_hd |= EXT_RTHDR2;
1581                                         break;
1582                                 default:
1583                                         if (V_fw_verbose)
1584                                                 printf("IPFW2: IPV6 - Unknown "
1585                                                     "Routing Header type(%d)\n",
1586                                                     ((struct ip6_rthdr *)
1587                                                     ulp)->ip6r_type);
1588                                         if (V_fw_deny_unknown_exthdrs)
1589                                             return (IP_FW_DENY);
1590                                         break;
1591                                 }
1592                                 ext_hd |= EXT_ROUTING;
1593                                 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3;
1594                                 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt;
1595                                 ulp = NULL;
1596                                 break;
1597
1598                         case IPPROTO_FRAGMENT:  /* RFC 2460 */
1599                                 PULLUP_TO(hlen, ulp, struct ip6_frag);
1600                                 ext_hd |= EXT_FRAGMENT;
1601                                 hlen += sizeof (struct ip6_frag);
1602                                 proto = ((struct ip6_frag *)ulp)->ip6f_nxt;
1603                                 offset = ((struct ip6_frag *)ulp)->ip6f_offlg &
1604                                         IP6F_OFF_MASK;
1605                                 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg &
1606                                         IP6F_MORE_FRAG;
1607                                 if (V_fw_permit_single_frag6 == 0 &&
1608                                     offset == 0 && ip6f_mf == 0) {
1609                                         if (V_fw_verbose)
1610                                                 printf("IPFW2: IPV6 - Invalid "
1611                                                     "Fragment Header\n");
1612                                         if (V_fw_deny_unknown_exthdrs)
1613                                             return (IP_FW_DENY);
1614                                         break;
1615                                 }
1616                                 args->f_id.extra =
1617                                     ntohl(((struct ip6_frag *)ulp)->ip6f_ident);
1618                                 ulp = NULL;
1619                                 break;
1620
1621                         case IPPROTO_DSTOPTS:   /* RFC 2460 */
1622                                 PULLUP_TO(hlen, ulp, struct ip6_hbh);
1623                                 ext_hd |= EXT_DSTOPTS;
1624                                 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
1625                                 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
1626                                 ulp = NULL;
1627                                 break;
1628
1629                         case IPPROTO_AH:        /* RFC 2402 */
1630                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
1631                                 ext_hd |= EXT_AH;
1632                                 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2;
1633                                 proto = ((struct ip6_ext *)ulp)->ip6e_nxt;
1634                                 ulp = NULL;
1635                                 break;
1636
1637                         case IPPROTO_ESP:       /* RFC 2406 */
1638                                 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */
1639                                 /* Anything past Seq# is variable length and
1640                                  * data past this ext. header is encrypted. */
1641                                 ext_hd |= EXT_ESP;
1642                                 break;
1643
1644                         case IPPROTO_NONE:      /* RFC 2460 */
1645                                 /*
1646                                  * Packet ends here, and IPv6 header has
1647                                  * already been pulled up. If ip6e_len!=0
1648                                  * then octets must be ignored.
1649                                  */
1650                                 ulp = ip; /* non-NULL to get out of loop. */
1651                                 break;
1652
1653                         case IPPROTO_OSPFIGP:
1654                                 /* XXX OSPF header check? */
1655                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
1656                                 break;
1657
1658                         case IPPROTO_PIM:
1659                                 /* XXX PIM header check? */
1660                                 PULLUP_TO(hlen, ulp, struct pim);
1661                                 break;
1662
1663                         case IPPROTO_GRE:       /* RFC 1701 */
1664                                 /* XXX GRE header check? */
1665                                 PULLUP_TO(hlen, ulp, struct grehdr);
1666                                 break;
1667
1668                         case IPPROTO_CARP:
1669                                 PULLUP_TO(hlen, ulp, offsetof(
1670                                     struct carp_header, carp_counter));
1671                                 if (CARP_ADVERTISEMENT !=
1672                                     ((struct carp_header *)ulp)->carp_type)
1673                                         return (IP_FW_DENY);
1674                                 break;
1675
1676                         case IPPROTO_IPV6:      /* RFC 2893 */
1677                                 PULLUP_TO(hlen, ulp, struct ip6_hdr);
1678                                 break;
1679
1680                         case IPPROTO_IPV4:      /* RFC 2893 */
1681                                 PULLUP_TO(hlen, ulp, struct ip);
1682                                 break;
1683
1684                         default:
1685                                 if (V_fw_verbose)
1686                                         printf("IPFW2: IPV6 - Unknown "
1687                                             "Extension Header(%d), ext_hd=%x\n",
1688                                              proto, ext_hd);
1689                                 if (V_fw_deny_unknown_exthdrs)
1690                                     return (IP_FW_DENY);
1691                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
1692                                 break;
1693                         } /*switch */
1694                 }
1695                 UPDATE_POINTERS();
1696                 ip6 = (struct ip6_hdr *)ip;
1697                 args->f_id.addr_type = 6;
1698                 args->f_id.src_ip6 = ip6->ip6_src;
1699                 args->f_id.dst_ip6 = ip6->ip6_dst;
1700                 args->f_id.flow_id6 = ntohl(ip6->ip6_flow);
1701                 iplen = ntohs(ip6->ip6_plen) + sizeof(*ip6);
1702         } else if (pktlen >= sizeof(struct ip) &&
1703             (eh == NULL || eh->ether_type == htons(ETHERTYPE_IP)) &&
1704             ip->ip_v == 4) {
1705                 is_ipv4 = 1;
1706                 args->flags |= IPFW_ARGS_IP4;
1707                 hlen = ip->ip_hl << 2;
1708                 /*
1709                  * Collect parameters into local variables for faster
1710                  * matching.
1711                  */
1712                 proto = ip->ip_p;
1713                 src_ip = ip->ip_src;
1714                 dst_ip = ip->ip_dst;
1715                 offset = ntohs(ip->ip_off) & IP_OFFMASK;
1716                 iplen = ntohs(ip->ip_len);
1717
1718                 if (offset == 0) {
1719                         switch (proto) {
1720                         case IPPROTO_TCP:
1721                                 PULLUP_TO(hlen, ulp, struct tcphdr);
1722                                 dst_port = TCP(ulp)->th_dport;
1723                                 src_port = TCP(ulp)->th_sport;
1724                                 /* save flags for dynamic rules */
1725                                 args->f_id._flags = TCP(ulp)->th_flags;
1726                                 break;
1727
1728                         case IPPROTO_SCTP:
1729                                 if (pktlen >= hlen + sizeof(struct sctphdr) +
1730                                     sizeof(struct sctp_chunkhdr) +
1731                                     offsetof(struct sctp_init, a_rwnd))
1732                                         PULLUP_LEN(hlen, ulp,
1733                                             sizeof(struct sctphdr) +
1734                                             sizeof(struct sctp_chunkhdr) +
1735                                             offsetof(struct sctp_init, a_rwnd));
1736                                 else if (pktlen >= hlen + sizeof(struct sctphdr))
1737                                         PULLUP_LEN(hlen, ulp, pktlen - hlen);
1738                                 else
1739                                         PULLUP_LEN(hlen, ulp,
1740                                             sizeof(struct sctphdr));
1741                                 src_port = SCTP(ulp)->src_port;
1742                                 dst_port = SCTP(ulp)->dest_port;
1743                                 break;
1744
1745                         case IPPROTO_UDP:
1746                         case IPPROTO_UDPLITE:
1747                                 PULLUP_TO(hlen, ulp, struct udphdr);
1748                                 dst_port = UDP(ulp)->uh_dport;
1749                                 src_port = UDP(ulp)->uh_sport;
1750                                 break;
1751
1752                         case IPPROTO_ICMP:
1753                                 PULLUP_TO(hlen, ulp, struct icmphdr);
1754                                 //args->f_id.flags = ICMP(ulp)->icmp_type;
1755                                 break;
1756
1757                         default:
1758                                 break;
1759                         }
1760                 } else {
1761                         if (offset == 1 && proto == IPPROTO_TCP) {
1762                                 /* RFC 3128 */
1763                                 goto pullup_failed;
1764                         }
1765                 }
1766
1767                 UPDATE_POINTERS();
1768                 args->f_id.addr_type = 4;
1769                 args->f_id.src_ip = ntohl(src_ip.s_addr);
1770                 args->f_id.dst_ip = ntohl(dst_ip.s_addr);
1771         } else {
1772                 proto = 0;
1773                 dst_ip.s_addr = src_ip.s_addr = 0;
1774
1775                 args->f_id.addr_type = 1; /* XXX */
1776         }
1777 #undef PULLUP_TO
1778         pktlen = iplen < pktlen ? iplen: pktlen;
1779
1780         /* Properly initialize the rest of f_id */
1781         args->f_id.proto = proto;
1782         args->f_id.src_port = src_port = ntohs(src_port);
1783         args->f_id.dst_port = dst_port = ntohs(dst_port);
1784
1785         IPFW_PF_RLOCK(chain);
1786         if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */
1787                 IPFW_PF_RUNLOCK(chain);
1788                 return (IP_FW_PASS);    /* accept */
1789         }
1790         if (args->flags & IPFW_ARGS_REF) {
1791                 /*
1792                  * Packet has already been tagged as a result of a previous
1793                  * match on rule args->rule aka args->rule_id (PIPE, QUEUE,
1794                  * REASS, NETGRAPH, DIVERT/TEE...)
1795                  * Validate the slot and continue from the next one
1796                  * if still present, otherwise do a lookup.
1797                  */
1798                 f_pos = (args->rule.chain_id == chain->id) ?
1799                     args->rule.slot :
1800                     ipfw_find_rule(chain, args->rule.rulenum,
1801                         args->rule.rule_id);
1802         } else {
1803                 f_pos = 0;
1804         }
1805
1806         if (args->flags & IPFW_ARGS_IN) {
1807                 iif = args->ifp;
1808                 oif = NULL;
1809         } else {
1810                 MPASS(args->flags & IPFW_ARGS_OUT);
1811                 iif = mem ? NULL : m_rcvif(m);
1812                 oif = args->ifp;
1813         }
1814
1815         /*
1816          * Now scan the rules, and parse microinstructions for each rule.
1817          * We have two nested loops and an inner switch. Sometimes we
1818          * need to break out of one or both loops, or re-enter one of
1819          * the loops with updated variables. Loop variables are:
1820          *
1821          *      f_pos (outer loop) points to the current rule.
1822          *              On output it points to the matching rule.
1823          *      done (outer loop) is used as a flag to break the loop.
1824          *      l (inner loop)  residual length of current rule.
1825          *              cmd points to the current microinstruction.
1826          *
1827          * We break the inner loop by setting l=0 and possibly
1828          * cmdlen=0 if we don't want to advance cmd.
1829          * We break the outer loop by setting done=1
1830          * We can restart the inner loop by setting l>0 and f_pos, f, cmd
1831          * as needed.
1832          */
1833         for (; f_pos < chain->n_rules; f_pos++) {
1834                 ipfw_insn *cmd;
1835                 uint32_t tablearg = 0;
1836                 int l, cmdlen, skip_or; /* skip rest of OR block */
1837                 struct ip_fw *f;
1838
1839                 f = chain->map[f_pos];
1840                 if (V_set_disable & (1 << f->set) )
1841                         continue;
1842
1843                 skip_or = 0;
1844                 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ;
1845                     l -= cmdlen, cmd += cmdlen) {
1846                         int match;
1847
1848                         /*
1849                          * check_body is a jump target used when we find a
1850                          * CHECK_STATE, and need to jump to the body of
1851                          * the target rule.
1852                          */
1853
1854 /* check_body: */
1855                         cmdlen = F_LEN(cmd);
1856                         /*
1857                          * An OR block (insn_1 || .. || insn_n) has the
1858                          * F_OR bit set in all but the last instruction.
1859                          * The first match will set "skip_or", and cause
1860                          * the following instructions to be skipped until
1861                          * past the one with the F_OR bit clear.
1862                          */
1863                         if (skip_or) {          /* skip this instruction */
1864                                 if ((cmd->len & F_OR) == 0)
1865                                         skip_or = 0;    /* next one is good */
1866                                 continue;
1867                         }
1868                         match = 0; /* set to 1 if we succeed */
1869
1870                         switch (cmd->opcode) {
1871                         /*
1872                          * The first set of opcodes compares the packet's
1873                          * fields with some pattern, setting 'match' if a
1874                          * match is found. At the end of the loop there is
1875                          * logic to deal with F_NOT and F_OR flags associated
1876                          * with the opcode.
1877                          */
1878                         case O_NOP:
1879                                 match = 1;
1880                                 break;
1881
1882                         case O_FORWARD_MAC:
1883                                 printf("ipfw: opcode %d unimplemented\n",
1884                                     cmd->opcode);
1885                                 break;
1886
1887                         case O_GID:
1888                         case O_UID:
1889                         case O_JAIL:
1890                                 /*
1891                                  * We only check offset == 0 && proto != 0,
1892                                  * as this ensures that we have a
1893                                  * packet with the ports info.
1894                                  */
1895                                 if (offset != 0)
1896                                         break;
1897                                 if (proto == IPPROTO_TCP ||
1898                                     proto == IPPROTO_UDP ||
1899                                     proto == IPPROTO_UDPLITE)
1900                                         match = check_uidgid(
1901                                                     (ipfw_insn_u32 *)cmd,
1902                                                     args, &ucred_lookup,
1903 #ifdef __FreeBSD__
1904                                                     &ucred_cache);
1905 #else
1906                                                     (void *)&ucred_cache);
1907 #endif
1908                                 break;
1909
1910                         case O_RECV:
1911                                 match = iface_match(iif, (ipfw_insn_if *)cmd,
1912                                     chain, &tablearg);
1913                                 break;
1914
1915                         case O_XMIT:
1916                                 match = iface_match(oif, (ipfw_insn_if *)cmd,
1917                                     chain, &tablearg);
1918                                 break;
1919
1920                         case O_VIA:
1921                                 match = iface_match(args->ifp,
1922                                     (ipfw_insn_if *)cmd, chain, &tablearg);
1923                                 break;
1924
1925                         case O_MACADDR2:
1926                                 if (args->flags & IPFW_ARGS_ETHER) {
1927                                         u_int32_t *want = (u_int32_t *)
1928                                                 ((ipfw_insn_mac *)cmd)->addr;
1929                                         u_int32_t *mask = (u_int32_t *)
1930                                                 ((ipfw_insn_mac *)cmd)->mask;
1931                                         u_int32_t *hdr = (u_int32_t *)eh;
1932
1933                                         match =
1934                                             ( want[0] == (hdr[0] & mask[0]) &&
1935                                               want[1] == (hdr[1] & mask[1]) &&
1936                                               want[2] == (hdr[2] & mask[2]) );
1937                                 }
1938                                 break;
1939
1940                         case O_MAC_TYPE:
1941                                 if (args->flags & IPFW_ARGS_ETHER) {
1942                                         u_int16_t *p =
1943                                             ((ipfw_insn_u16 *)cmd)->ports;
1944                                         int i;
1945
1946                                         for (i = cmdlen - 1; !match && i>0;
1947                                             i--, p += 2)
1948                                                 match =
1949                                                     (ntohs(eh->ether_type) >=
1950                                                     p[0] &&
1951                                                     ntohs(eh->ether_type) <=
1952                                                     p[1]);
1953                                 }
1954                                 break;
1955
1956                         case O_FRAG:
1957                                 if (is_ipv4) {
1958                                         /*
1959                                          * Since flags_match() works with
1960                                          * uint8_t we pack ip_off into 8 bits.
1961                                          * For this match offset is a boolean.
1962                                          */
1963                                         match = flags_match(cmd,
1964                                             ((ntohs(ip->ip_off) & ~IP_OFFMASK)
1965                                             >> 8) | (offset != 0));
1966                                 } else {
1967                                         /*
1968                                          * Compatiblity: historically bare
1969                                          * "frag" would match IPv6 fragments.
1970                                          */
1971                                         match = (cmd->arg1 == 0x1 &&
1972                                             (offset != 0));
1973                                 }
1974                                 break;
1975
1976                         case O_IN:      /* "out" is "not in" */
1977                                 match = (oif == NULL);
1978                                 break;
1979
1980                         case O_LAYER2:
1981                                 match = (args->flags & IPFW_ARGS_ETHER);
1982                                 break;
1983
1984                         case O_DIVERTED:
1985                                 if ((args->flags & IPFW_ARGS_REF) == 0)
1986                                         break;
1987                                 /*
1988                                  * For diverted packets, args->rule.info
1989                                  * contains the divert port (in host format)
1990                                  * reason and direction.
1991                                  */
1992                                 match = ((args->rule.info & IPFW_IS_MASK) ==
1993                                     IPFW_IS_DIVERT) && (
1994                                     ((args->rule.info & IPFW_INFO_IN) ?
1995                                         1: 2) & cmd->arg1);
1996                                 break;
1997
1998                         case O_PROTO:
1999                                 /*
2000                                  * We do not allow an arg of 0 so the
2001                                  * check of "proto" only suffices.
2002                                  */
2003                                 match = (proto == cmd->arg1);
2004                                 break;
2005
2006                         case O_IP_SRC:
2007                                 match = is_ipv4 &&
2008                                     (((ipfw_insn_ip *)cmd)->addr.s_addr ==
2009                                     src_ip.s_addr);
2010                                 break;
2011
2012                         case O_IP_DST_LOOKUP:
2013                         {
2014                                 void *pkey;
2015                                 uint32_t vidx, key;
2016                                 uint16_t keylen;
2017
2018                                 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) {
2019                                         /* Determine lookup key type */
2020                                         vidx = ((ipfw_insn_u32 *)cmd)->d[1];
2021                                         if (vidx != 4 /* uid */ &&
2022                                             vidx != 5 /* jail */ &&
2023                                             is_ipv6 == 0 && is_ipv4 == 0)
2024                                                 break;
2025                                         /* Determine key length */
2026                                         if (vidx == 0 /* dst-ip */ ||
2027                                             vidx == 1 /* src-ip */)
2028                                                 keylen = is_ipv6 ?
2029                                                     sizeof(struct in6_addr):
2030                                                     sizeof(in_addr_t);
2031                                         else {
2032                                                 keylen = sizeof(key);
2033                                                 pkey = &key;
2034                                         }
2035                                         if (vidx == 0 /* dst-ip */)
2036                                                 pkey = is_ipv4 ? (void *)&dst_ip:
2037                                                     (void *)&args->f_id.dst_ip6;
2038                                         else if (vidx == 1 /* src-ip */)
2039                                                 pkey = is_ipv4 ? (void *)&src_ip:
2040                                                     (void *)&args->f_id.src_ip6;
2041                                         else if (vidx == 6 /* dscp */) {
2042                                                 if (is_ipv4)
2043                                                         key = ip->ip_tos >> 2;
2044                                                 else {
2045                                                         key = args->f_id.flow_id6;
2046                                                         key = (key & 0x0f) << 2 |
2047                                                             (key & 0xf000) >> 14;
2048                                                 }
2049                                                 key &= 0x3f;
2050                                         } else if (vidx == 2 /* dst-port */ ||
2051                                             vidx == 3 /* src-port */) {
2052                                                 /* Skip fragments */
2053                                                 if (offset != 0)
2054                                                         break;
2055                                                 /* Skip proto without ports */
2056                                                 if (proto != IPPROTO_TCP &&
2057                                                     proto != IPPROTO_UDP &&
2058                                                     proto != IPPROTO_UDPLITE &&
2059                                                     proto != IPPROTO_SCTP)
2060                                                         break;
2061                                                 if (vidx == 2 /* dst-port */)
2062                                                         key = dst_port;
2063                                                 else
2064                                                         key = src_port;
2065                                         }
2066 #ifndef USERSPACE
2067                                         else if (vidx == 4 /* uid */ ||
2068                                             vidx == 5 /* jail */) {
2069                                                 check_uidgid(
2070                                                     (ipfw_insn_u32 *)cmd,
2071                                                     args, &ucred_lookup,
2072 #ifdef __FreeBSD__
2073                                                     &ucred_cache);
2074                                                 if (vidx == 4 /* uid */)
2075                                                         key = ucred_cache->cr_uid;
2076                                                 else if (vidx == 5 /* jail */)
2077                                                         key = ucred_cache->cr_prison->pr_id;
2078 #else /* !__FreeBSD__ */
2079                                                     (void *)&ucred_cache);
2080                                                 if (vidx == 4 /* uid */)
2081                                                         key = ucred_cache.uid;
2082                                                 else if (vidx == 5 /* jail */)
2083                                                         key = ucred_cache.xid;
2084 #endif /* !__FreeBSD__ */
2085                                         }
2086 #endif /* !USERSPACE */
2087                                         else
2088                                                 break;
2089                                         match = ipfw_lookup_table(chain,
2090                                             cmd->arg1, keylen, pkey, &vidx);
2091                                         if (!match)
2092                                                 break;
2093                                         tablearg = vidx;
2094                                         break;
2095                                 }
2096                                 /* cmdlen =< F_INSN_SIZE(ipfw_insn_u32) */
2097                                 /* FALLTHROUGH */
2098                         }
2099                         case O_IP_SRC_LOOKUP:
2100                         {
2101                                 void *pkey;
2102                                 uint32_t vidx;
2103                                 uint16_t keylen;
2104
2105                                 if (is_ipv4) {
2106                                         keylen = sizeof(in_addr_t);
2107                                         if (cmd->opcode == O_IP_DST_LOOKUP)
2108                                                 pkey = &dst_ip;
2109                                         else
2110                                                 pkey = &src_ip;
2111                                 } else if (is_ipv6) {
2112                                         keylen = sizeof(struct in6_addr);
2113                                         if (cmd->opcode == O_IP_DST_LOOKUP)
2114                                                 pkey = &args->f_id.dst_ip6;
2115                                         else
2116                                                 pkey = &args->f_id.src_ip6;
2117                                 } else
2118                                         break;
2119                                 match = ipfw_lookup_table(chain, cmd->arg1,
2120                                     keylen, pkey, &vidx);
2121                                 if (!match)
2122                                         break;
2123                                 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) {
2124                                         match = ((ipfw_insn_u32 *)cmd)->d[0] ==
2125                                             TARG_VAL(chain, vidx, tag);
2126                                         if (!match)
2127                                                 break;
2128                                 }
2129                                 tablearg = vidx;
2130                                 break;
2131                         }
2132
2133                         case O_IP_FLOW_LOOKUP:
2134                                 {
2135                                         uint32_t v = 0;
2136                                         match = ipfw_lookup_table(chain,
2137                                             cmd->arg1, 0, &args->f_id, &v);
2138                                         if (!match)
2139                                                 break;
2140                                         if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
2141                                                 match = ((ipfw_insn_u32 *)cmd)->d[0] ==
2142                                                     TARG_VAL(chain, v, tag);
2143                                         if (match)
2144                                                 tablearg = v;
2145                                 }
2146                                 break;
2147                         case O_IP_SRC_MASK:
2148                         case O_IP_DST_MASK:
2149                                 if (is_ipv4) {
2150                                     uint32_t a =
2151                                         (cmd->opcode == O_IP_DST_MASK) ?
2152                                             dst_ip.s_addr : src_ip.s_addr;
2153                                     uint32_t *p = ((ipfw_insn_u32 *)cmd)->d;
2154                                     int i = cmdlen-1;
2155
2156                                     for (; !match && i>0; i-= 2, p+= 2)
2157                                         match = (p[0] == (a & p[1]));
2158                                 }
2159                                 break;
2160
2161                         case O_IP_SRC_ME:
2162                                 if (is_ipv4) {
2163                                         match = in_localip(src_ip);
2164                                         break;
2165                                 }
2166 #ifdef INET6
2167                                 /* FALLTHROUGH */
2168                         case O_IP6_SRC_ME:
2169                                 match = is_ipv6 &&
2170                                     ipfw_localip6(&args->f_id.src_ip6);
2171 #endif
2172                                 break;
2173
2174                         case O_IP_DST_SET:
2175                         case O_IP_SRC_SET:
2176                                 if (is_ipv4) {
2177                                         u_int32_t *d = (u_int32_t *)(cmd+1);
2178                                         u_int32_t addr =
2179                                             cmd->opcode == O_IP_DST_SET ?
2180                                                 args->f_id.dst_ip :
2181                                                 args->f_id.src_ip;
2182
2183                                             if (addr < d[0])
2184                                                     break;
2185                                             addr -= d[0]; /* subtract base */
2186                                             match = (addr < cmd->arg1) &&
2187                                                 ( d[ 1 + (addr>>5)] &
2188                                                   (1<<(addr & 0x1f)) );
2189                                 }
2190                                 break;
2191
2192                         case O_IP_DST:
2193                                 match = is_ipv4 &&
2194                                     (((ipfw_insn_ip *)cmd)->addr.s_addr ==
2195                                     dst_ip.s_addr);
2196                                 break;
2197
2198                         case O_IP_DST_ME:
2199                                 if (is_ipv4) {
2200                                         match = in_localip(dst_ip);
2201                                         break;
2202                                 }
2203 #ifdef INET6
2204                                 /* FALLTHROUGH */
2205                         case O_IP6_DST_ME:
2206                                 match = is_ipv6 &&
2207                                     ipfw_localip6(&args->f_id.dst_ip6);
2208 #endif
2209                                 break;
2210
2211                         case O_IP_SRCPORT:
2212                         case O_IP_DSTPORT:
2213                                 /*
2214                                  * offset == 0 && proto != 0 is enough
2215                                  * to guarantee that we have a
2216                                  * packet with port info.
2217                                  */
2218                                 if ((proto == IPPROTO_UDP ||
2219                                     proto == IPPROTO_UDPLITE ||
2220                                     proto == IPPROTO_TCP ||
2221                                     proto == IPPROTO_SCTP) && offset == 0) {
2222                                         u_int16_t x =
2223                                             (cmd->opcode == O_IP_SRCPORT) ?
2224                                                 src_port : dst_port ;
2225                                         u_int16_t *p =
2226                                             ((ipfw_insn_u16 *)cmd)->ports;
2227                                         int i;
2228
2229                                         for (i = cmdlen - 1; !match && i>0;
2230                                             i--, p += 2)
2231                                                 match = (x>=p[0] && x<=p[1]);
2232                                 }
2233                                 break;
2234
2235                         case O_ICMPTYPE:
2236                                 match = (offset == 0 && proto==IPPROTO_ICMP &&
2237                                     icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) );
2238                                 break;
2239
2240 #ifdef INET6
2241                         case O_ICMP6TYPE:
2242                                 match = is_ipv6 && offset == 0 &&
2243                                     proto==IPPROTO_ICMPV6 &&
2244                                     icmp6type_match(
2245                                         ICMP6(ulp)->icmp6_type,
2246                                         (ipfw_insn_u32 *)cmd);
2247                                 break;
2248 #endif /* INET6 */
2249
2250                         case O_IPOPT:
2251                                 match = (is_ipv4 &&
2252                                     ipopts_match(ip, cmd) );
2253                                 break;
2254
2255                         case O_IPVER:
2256                                 match = ((is_ipv4 || is_ipv6) &&
2257                                     cmd->arg1 == ip->ip_v);
2258                                 break;
2259
2260                         case O_IPID:
2261                         case O_IPTTL:
2262                                 if (!is_ipv4)
2263                                         break;
2264                         case O_IPLEN:
2265                                 {       /* only for IP packets */
2266                                     uint16_t x;
2267                                     uint16_t *p;
2268                                     int i;
2269
2270                                     if (cmd->opcode == O_IPLEN)
2271                                         x = iplen;
2272                                     else if (cmd->opcode == O_IPTTL)
2273                                         x = ip->ip_ttl;
2274                                     else /* must be IPID */
2275                                         x = ntohs(ip->ip_id);
2276                                     if (cmdlen == 1) {
2277                                         match = (cmd->arg1 == x);
2278                                         break;
2279                                     }
2280                                     /* otherwise we have ranges */
2281                                     p = ((ipfw_insn_u16 *)cmd)->ports;
2282                                     i = cmdlen - 1;
2283                                     for (; !match && i>0; i--, p += 2)
2284                                         match = (x >= p[0] && x <= p[1]);
2285                                 }
2286                                 break;
2287
2288                         case O_IPPRECEDENCE:
2289                                 match = (is_ipv4 &&
2290                                     (cmd->arg1 == (ip->ip_tos & 0xe0)) );
2291                                 break;
2292
2293                         case O_IPTOS:
2294                                 match = (is_ipv4 &&
2295                                     flags_match(cmd, ip->ip_tos));
2296                                 break;
2297
2298                         case O_DSCP:
2299                             {
2300                                 uint32_t *p;
2301                                 uint16_t x;
2302
2303                                 p = ((ipfw_insn_u32 *)cmd)->d;
2304
2305                                 if (is_ipv4)
2306                                         x = ip->ip_tos >> 2;
2307                                 else if (is_ipv6) {
2308                                         uint8_t *v;
2309                                         v = &((struct ip6_hdr *)ip)->ip6_vfc;
2310                                         x = (*v & 0x0F) << 2;
2311                                         v++;
2312                                         x |= *v >> 6;
2313                                 } else
2314                                         break;
2315
2316                                 /* DSCP bitmask is stored as low_u32 high_u32 */
2317                                 if (x >= 32)
2318                                         match = *(p + 1) & (1 << (x - 32));
2319                                 else
2320                                         match = *p & (1 << x);
2321                             }
2322                                 break;
2323
2324                         case O_TCPDATALEN:
2325                                 if (proto == IPPROTO_TCP && offset == 0) {
2326                                     struct tcphdr *tcp;
2327                                     uint16_t x;
2328                                     uint16_t *p;
2329                                     int i;
2330 #ifdef INET6
2331                                     if (is_ipv6) {
2332                                             struct ip6_hdr *ip6;
2333
2334                                             ip6 = (struct ip6_hdr *)ip;
2335                                             if (ip6->ip6_plen == 0) {
2336                                                     /*
2337                                                      * Jumbo payload is not
2338                                                      * supported by this
2339                                                      * opcode.
2340                                                      */
2341                                                     break;
2342                                             }
2343                                             x = iplen - hlen;
2344                                     } else
2345 #endif /* INET6 */
2346                                             x = iplen - (ip->ip_hl << 2);
2347                                     tcp = TCP(ulp);
2348                                     x -= tcp->th_off << 2;
2349                                     if (cmdlen == 1) {
2350                                         match = (cmd->arg1 == x);
2351                                         break;
2352                                     }
2353                                     /* otherwise we have ranges */
2354                                     p = ((ipfw_insn_u16 *)cmd)->ports;
2355                                     i = cmdlen - 1;
2356                                     for (; !match && i>0; i--, p += 2)
2357                                         match = (x >= p[0] && x <= p[1]);
2358                                 }
2359                                 break;
2360
2361                         case O_TCPFLAGS:
2362                                 match = (proto == IPPROTO_TCP && offset == 0 &&
2363                                     flags_match(cmd, TCP(ulp)->th_flags));
2364                                 break;
2365
2366                         case O_TCPOPTS:
2367                                 if (proto == IPPROTO_TCP && offset == 0 && ulp){
2368                                         PULLUP_LEN_LOCKED(hlen, ulp,
2369                                             (TCP(ulp)->th_off << 2));
2370                                         match = tcpopts_match(TCP(ulp), cmd);
2371                                 }
2372                                 break;
2373
2374                         case O_TCPSEQ:
2375                                 match = (proto == IPPROTO_TCP && offset == 0 &&
2376                                     ((ipfw_insn_u32 *)cmd)->d[0] ==
2377                                         TCP(ulp)->th_seq);
2378                                 break;
2379
2380                         case O_TCPACK:
2381                                 match = (proto == IPPROTO_TCP && offset == 0 &&
2382                                     ((ipfw_insn_u32 *)cmd)->d[0] ==
2383                                         TCP(ulp)->th_ack);
2384                                 break;
2385
2386                         case O_TCPMSS:
2387                                 if (proto == IPPROTO_TCP &&
2388                                     (args->f_id._flags & TH_SYN) != 0 &&
2389                                     ulp != NULL) {
2390                                         uint16_t mss, *p;
2391                                         int i;
2392
2393                                         PULLUP_LEN_LOCKED(hlen, ulp,
2394                                             (TCP(ulp)->th_off << 2));
2395                                         if ((tcpopts_parse(TCP(ulp), &mss) &
2396                                             IP_FW_TCPOPT_MSS) == 0)
2397                                                 break;
2398                                         if (cmdlen == 1) {
2399                                                 match = (cmd->arg1 == mss);
2400                                                 break;
2401                                         }
2402                                         /* Otherwise we have ranges. */
2403                                         p = ((ipfw_insn_u16 *)cmd)->ports;
2404                                         i = cmdlen - 1;
2405                                         for (; !match && i > 0; i--, p += 2)
2406                                                 match = (mss >= p[0] &&
2407                                                     mss <= p[1]);
2408                                 }
2409                                 break;
2410
2411                         case O_TCPWIN:
2412                                 if (proto == IPPROTO_TCP && offset == 0) {
2413                                     uint16_t x;
2414                                     uint16_t *p;
2415                                     int i;
2416
2417                                     x = ntohs(TCP(ulp)->th_win);
2418                                     if (cmdlen == 1) {
2419                                         match = (cmd->arg1 == x);
2420                                         break;
2421                                     }
2422                                     /* Otherwise we have ranges. */
2423                                     p = ((ipfw_insn_u16 *)cmd)->ports;
2424                                     i = cmdlen - 1;
2425                                     for (; !match && i > 0; i--, p += 2)
2426                                         match = (x >= p[0] && x <= p[1]);
2427                                 }
2428                                 break;
2429
2430                         case O_ESTAB:
2431                                 /* reject packets which have SYN only */
2432                                 /* XXX should i also check for TH_ACK ? */
2433                                 match = (proto == IPPROTO_TCP && offset == 0 &&
2434                                     (TCP(ulp)->th_flags &
2435                                      (TH_RST | TH_ACK | TH_SYN)) != TH_SYN);
2436                                 break;
2437
2438                         case O_ALTQ: {
2439                                 struct pf_mtag *at;
2440                                 struct m_tag *mtag;
2441                                 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd;
2442
2443                                 /*
2444                                  * ALTQ uses mbuf tags from another
2445                                  * packet filtering system - pf(4).
2446                                  * We allocate a tag in its format
2447                                  * and fill it in, pretending to be pf(4).
2448                                  */
2449                                 match = 1;
2450                                 at = pf_find_mtag(m);
2451                                 if (at != NULL && at->qid != 0)
2452                                         break;
2453                                 mtag = m_tag_get(PACKET_TAG_PF,
2454                                     sizeof(struct pf_mtag), M_NOWAIT | M_ZERO);
2455                                 if (mtag == NULL) {
2456                                         /*
2457                                          * Let the packet fall back to the
2458                                          * default ALTQ.
2459                                          */
2460                                         break;
2461                                 }
2462                                 m_tag_prepend(m, mtag);
2463                                 at = (struct pf_mtag *)(mtag + 1);
2464                                 at->qid = altq->qid;
2465                                 at->hdr = ip;
2466                                 break;
2467                         }
2468
2469                         case O_LOG:
2470                                 ipfw_log(chain, f, hlen, args,
2471                                     offset | ip6f_mf, tablearg, ip);
2472                                 match = 1;
2473                                 break;
2474
2475                         case O_PROB:
2476                                 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]);
2477                                 break;
2478
2479                         case O_VERREVPATH:
2480                                 /* Outgoing packets automatically pass/match */
2481                                 match = (args->flags & IPFW_ARGS_OUT ||
2482                                     (
2483 #ifdef INET6
2484                                     is_ipv6 ?
2485                                         verify_path6(&(args->f_id.src_ip6),
2486                                             iif, args->f_id.fib) :
2487 #endif
2488                                     verify_path(src_ip, iif, args->f_id.fib)));
2489                                 break;
2490
2491                         case O_VERSRCREACH:
2492                                 /* Outgoing packets automatically pass/match */
2493                                 match = (hlen > 0 && ((oif != NULL) || (
2494 #ifdef INET6
2495                                     is_ipv6 ?
2496                                         verify_path6(&(args->f_id.src_ip6),
2497                                             NULL, args->f_id.fib) :
2498 #endif
2499                                     verify_path(src_ip, NULL, args->f_id.fib))));
2500                                 break;
2501
2502                         case O_ANTISPOOF:
2503                                 /* Outgoing packets automatically pass/match */
2504                                 if (oif == NULL && hlen > 0 &&
2505                                     (  (is_ipv4 && in_localaddr(src_ip))
2506 #ifdef INET6
2507                                     || (is_ipv6 &&
2508                                         in6_localaddr(&(args->f_id.src_ip6)))
2509 #endif
2510                                     ))
2511                                         match =
2512 #ifdef INET6
2513                                             is_ipv6 ? verify_path6(
2514                                                 &(args->f_id.src_ip6), iif,
2515                                                 args->f_id.fib) :
2516 #endif
2517                                             verify_path(src_ip, iif,
2518                                                 args->f_id.fib);
2519                                 else
2520                                         match = 1;
2521                                 break;
2522
2523                         case O_IPSEC:
2524                                 match = (m_tag_find(m,
2525                                     PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL);
2526                                 /* otherwise no match */
2527                                 break;
2528
2529 #ifdef INET6
2530                         case O_IP6_SRC:
2531                                 match = is_ipv6 &&
2532                                     IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6,
2533                                     &((ipfw_insn_ip6 *)cmd)->addr6);
2534                                 break;
2535
2536                         case O_IP6_DST:
2537                                 match = is_ipv6 &&
2538                                 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6,
2539                                     &((ipfw_insn_ip6 *)cmd)->addr6);
2540                                 break;
2541                         case O_IP6_SRC_MASK:
2542                         case O_IP6_DST_MASK:
2543                                 if (is_ipv6) {
2544                                         int i = cmdlen - 1;
2545                                         struct in6_addr p;
2546                                         struct in6_addr *d =
2547                                             &((ipfw_insn_ip6 *)cmd)->addr6;
2548
2549                                         for (; !match && i > 0; d += 2,
2550                                             i -= F_INSN_SIZE(struct in6_addr)
2551                                             * 2) {
2552                                                 p = (cmd->opcode ==
2553                                                     O_IP6_SRC_MASK) ?
2554                                                     args->f_id.src_ip6:
2555                                                     args->f_id.dst_ip6;
2556                                                 APPLY_MASK(&p, &d[1]);
2557                                                 match =
2558                                                     IN6_ARE_ADDR_EQUAL(&d[0],
2559                                                     &p);
2560                                         }
2561                                 }
2562                                 break;
2563
2564                         case O_FLOW6ID:
2565                                 match = is_ipv6 &&
2566                                     flow6id_match(args->f_id.flow_id6,
2567                                     (ipfw_insn_u32 *) cmd);
2568                                 break;
2569
2570                         case O_EXT_HDR:
2571                                 match = is_ipv6 &&
2572                                     (ext_hd & ((ipfw_insn *) cmd)->arg1);
2573                                 break;
2574
2575                         case O_IP6:
2576                                 match = is_ipv6;
2577                                 break;
2578 #endif
2579
2580                         case O_IP4:
2581                                 match = is_ipv4;
2582                                 break;
2583
2584                         case O_TAG: {
2585                                 struct m_tag *mtag;
2586                                 uint32_t tag = TARG(cmd->arg1, tag);
2587
2588                                 /* Packet is already tagged with this tag? */
2589                                 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL);
2590
2591                                 /* We have `untag' action when F_NOT flag is
2592                                  * present. And we must remove this mtag from
2593                                  * mbuf and reset `match' to zero (`match' will
2594                                  * be inversed later).
2595                                  * Otherwise we should allocate new mtag and
2596                                  * push it into mbuf.
2597                                  */
2598                                 if (cmd->len & F_NOT) { /* `untag' action */
2599                                         if (mtag != NULL)
2600                                                 m_tag_delete(m, mtag);
2601                                         match = 0;
2602                                 } else {
2603                                         if (mtag == NULL) {
2604                                                 mtag = m_tag_alloc( MTAG_IPFW,
2605                                                     tag, 0, M_NOWAIT);
2606                                                 if (mtag != NULL)
2607                                                         m_tag_prepend(m, mtag);
2608                                         }
2609                                         match = 1;
2610                                 }
2611                                 break;
2612                         }
2613
2614                         case O_FIB: /* try match the specified fib */
2615                                 if (args->f_id.fib == cmd->arg1)
2616                                         match = 1;
2617                                 break;
2618
2619                         case O_SOCKARG: {
2620 #ifndef USERSPACE       /* not supported in userspace */
2621                                 struct inpcb *inp = args->inp;
2622                                 struct inpcbinfo *pi;
2623
2624                                 if (is_ipv6) /* XXX can we remove this ? */
2625                                         break;
2626
2627                                 if (proto == IPPROTO_TCP)
2628                                         pi = &V_tcbinfo;
2629                                 else if (proto == IPPROTO_UDP)
2630                                         pi = &V_udbinfo;
2631                                 else if (proto == IPPROTO_UDPLITE)
2632                                         pi = &V_ulitecbinfo;
2633                                 else
2634                                         break;
2635
2636                                 /*
2637                                  * XXXRW: so_user_cookie should almost
2638                                  * certainly be inp_user_cookie?
2639                                  */
2640
2641                                 /* For incoming packet, lookup up the
2642                                 inpcb using the src/dest ip/port tuple */
2643                                 if (inp == NULL) {
2644                                         inp = in_pcblookup(pi,
2645                                                 src_ip, htons(src_port),
2646                                                 dst_ip, htons(dst_port),
2647                                                 INPLOOKUP_RLOCKPCB, NULL);
2648                                         if (inp != NULL) {
2649                                                 tablearg =
2650                                                     inp->inp_socket->so_user_cookie;
2651                                                 if (tablearg)
2652                                                         match = 1;
2653                                                 INP_RUNLOCK(inp);
2654                                         }
2655                                 } else {
2656                                         if (inp->inp_socket) {
2657                                                 tablearg =
2658                                                     inp->inp_socket->so_user_cookie;
2659                                                 if (tablearg)
2660                                                         match = 1;
2661                                         }
2662                                 }
2663 #endif /* !USERSPACE */
2664                                 break;
2665                         }
2666
2667                         case O_TAGGED: {
2668                                 struct m_tag *mtag;
2669                                 uint32_t tag = TARG(cmd->arg1, tag);
2670
2671                                 if (cmdlen == 1) {
2672                                         match = m_tag_locate(m, MTAG_IPFW,
2673                                             tag, NULL) != NULL;
2674                                         break;
2675                                 }
2676
2677                                 /* we have ranges */
2678                                 for (mtag = m_tag_first(m);
2679                                     mtag != NULL && !match;
2680                                     mtag = m_tag_next(m, mtag)) {
2681                                         uint16_t *p;
2682                                         int i;
2683
2684                                         if (mtag->m_tag_cookie != MTAG_IPFW)
2685                                                 continue;
2686
2687                                         p = ((ipfw_insn_u16 *)cmd)->ports;
2688                                         i = cmdlen - 1;
2689                                         for(; !match && i > 0; i--, p += 2)
2690                                                 match =
2691                                                     mtag->m_tag_id >= p[0] &&
2692                                                     mtag->m_tag_id <= p[1];
2693                                 }
2694                                 break;
2695                         }
2696
2697                         /*
2698                          * The second set of opcodes represents 'actions',
2699                          * i.e. the terminal part of a rule once the packet
2700                          * matches all previous patterns.
2701                          * Typically there is only one action for each rule,
2702                          * and the opcode is stored at the end of the rule
2703                          * (but there are exceptions -- see below).
2704                          *
2705                          * In general, here we set retval and terminate the
2706                          * outer loop (would be a 'break 3' in some language,
2707                          * but we need to set l=0, done=1)
2708                          *
2709                          * Exceptions:
2710                          * O_COUNT and O_SKIPTO actions:
2711                          *   instead of terminating, we jump to the next rule
2712                          *   (setting l=0), or to the SKIPTO target (setting
2713                          *   f/f_len, cmd and l as needed), respectively.
2714                          *
2715                          * O_TAG, O_LOG and O_ALTQ action parameters:
2716                          *   perform some action and set match = 1;
2717                          *
2718                          * O_LIMIT and O_KEEP_STATE: these opcodes are
2719                          *   not real 'actions', and are stored right
2720                          *   before the 'action' part of the rule (one
2721                          *   exception is O_SKIP_ACTION which could be
2722                          *   between these opcodes and 'action' one).
2723                          *   These opcodes try to install an entry in the
2724                          *   state tables; if successful, we continue with
2725                          *   the next opcode (match=1; break;), otherwise
2726                          *   the packet must be dropped (set retval,
2727                          *   break loops with l=0, done=1)
2728                          *
2729                          * O_PROBE_STATE and O_CHECK_STATE: these opcodes
2730                          *   cause a lookup of the state table, and a jump
2731                          *   to the 'action' part of the parent rule
2732                          *   if an entry is found, or
2733                          *   (CHECK_STATE only) a jump to the next rule if
2734                          *   the entry is not found.
2735                          *   The result of the lookup is cached so that
2736                          *   further instances of these opcodes become NOPs.
2737                          *   The jump to the next rule is done by setting
2738                          *   l=0, cmdlen=0.
2739                          *
2740                          * O_SKIP_ACTION: this opcode is not a real 'action'
2741                          *  either, and is stored right before the 'action'
2742                          *  part of the rule, right after the O_KEEP_STATE
2743                          *  opcode. It causes match failure so the real
2744                          *  'action' could be executed only if the rule
2745                          *  is checked via dynamic rule from the state
2746                          *  table, as in such case execution starts
2747                          *  from the true 'action' opcode directly.
2748                          *
2749                          */
2750                         case O_LIMIT:
2751                         case O_KEEP_STATE:
2752                                 if (ipfw_dyn_install_state(chain, f,
2753                                     (ipfw_insn_limit *)cmd, args, ulp,
2754                                     pktlen, &dyn_info, tablearg)) {
2755                                         /* error or limit violation */
2756                                         retval = IP_FW_DENY;
2757                                         l = 0;  /* exit inner loop */
2758                                         done = 1; /* exit outer loop */
2759                                 }
2760                                 match = 1;
2761                                 break;
2762
2763                         case O_PROBE_STATE:
2764                         case O_CHECK_STATE:
2765                                 /*
2766                                  * dynamic rules are checked at the first
2767                                  * keep-state or check-state occurrence,
2768                                  * with the result being stored in dyn_info.
2769                                  * The compiler introduces a PROBE_STATE
2770                                  * instruction for us when we have a
2771                                  * KEEP_STATE (because PROBE_STATE needs
2772                                  * to be run first).
2773                                  */
2774                                 if (DYN_LOOKUP_NEEDED(&dyn_info, cmd) &&
2775                                     (q = ipfw_dyn_lookup_state(args, ulp,
2776                                     pktlen, cmd, &dyn_info)) != NULL) {
2777                                         /*
2778                                          * Found dynamic entry, jump to the
2779                                          * 'action' part of the parent rule
2780                                          * by setting f, cmd, l and clearing
2781                                          * cmdlen.
2782                                          */
2783                                         f = q;
2784                                         f_pos = dyn_info.f_pos;
2785                                         cmd = ACTION_PTR(f);
2786                                         l = f->cmd_len - f->act_ofs;
2787                                         cmdlen = 0;
2788                                         match = 1;
2789                                         break;
2790                                 }
2791                                 /*
2792                                  * Dynamic entry not found. If CHECK_STATE,
2793                                  * skip to next rule, if PROBE_STATE just
2794                                  * ignore and continue with next opcode.
2795                                  */
2796                                 if (cmd->opcode == O_CHECK_STATE)
2797                                         l = 0;  /* exit inner loop */
2798                                 match = 1;
2799                                 break;
2800
2801                         case O_SKIP_ACTION:
2802                                 match = 0;      /* skip to the next rule */
2803                                 l = 0;          /* exit inner loop */
2804                                 break;
2805
2806                         case O_ACCEPT:
2807                                 retval = 0;     /* accept */
2808                                 l = 0;          /* exit inner loop */
2809                                 done = 1;       /* exit outer loop */
2810                                 break;
2811
2812                         case O_PIPE:
2813                         case O_QUEUE:
2814                                 set_match(args, f_pos, chain);
2815                                 args->rule.info = TARG(cmd->arg1, pipe);
2816                                 if (cmd->opcode == O_PIPE)
2817                                         args->rule.info |= IPFW_IS_PIPE;
2818                                 if (V_fw_one_pass)
2819                                         args->rule.info |= IPFW_ONEPASS;
2820                                 retval = IP_FW_DUMMYNET;
2821                                 l = 0;          /* exit inner loop */
2822                                 done = 1;       /* exit outer loop */
2823                                 break;
2824
2825                         case O_DIVERT:
2826                         case O_TEE:
2827                                 if (args->flags & IPFW_ARGS_ETHER)
2828                                         break;  /* not on layer 2 */
2829                                 /* otherwise this is terminal */
2830                                 l = 0;          /* exit inner loop */
2831                                 done = 1;       /* exit outer loop */
2832                                 retval = (cmd->opcode == O_DIVERT) ?
2833                                         IP_FW_DIVERT : IP_FW_TEE;
2834                                 set_match(args, f_pos, chain);
2835                                 args->rule.info = TARG(cmd->arg1, divert);
2836                                 break;
2837
2838                         case O_COUNT:
2839                                 IPFW_INC_RULE_COUNTER(f, pktlen);
2840                                 l = 0;          /* exit inner loop */
2841                                 break;
2842
2843                         case O_SKIPTO:
2844                             IPFW_INC_RULE_COUNTER(f, pktlen);
2845                             f_pos = JUMP(chain, f, cmd->arg1, tablearg, 0);
2846                             /*
2847                              * Skip disabled rules, and re-enter
2848                              * the inner loop with the correct
2849                              * f_pos, f, l and cmd.
2850                              * Also clear cmdlen and skip_or
2851                              */
2852                             for (; f_pos < chain->n_rules - 1 &&
2853                                     (V_set_disable &
2854                                      (1 << chain->map[f_pos]->set));
2855                                     f_pos++)
2856                                 ;
2857                             /* Re-enter the inner loop at the skipto rule. */
2858                             f = chain->map[f_pos];
2859                             l = f->cmd_len;
2860                             cmd = f->cmd;
2861                             match = 1;
2862                             cmdlen = 0;
2863                             skip_or = 0;
2864                             continue;
2865                             break;      /* not reached */
2866
2867                         case O_CALLRETURN: {
2868                                 /*
2869                                  * Implementation of `subroutine' call/return,
2870                                  * in the stack carried in an mbuf tag. This
2871                                  * is different from `skipto' in that any call
2872                                  * address is possible (`skipto' must prevent
2873                                  * backward jumps to avoid endless loops).
2874                                  * We have `return' action when F_NOT flag is
2875                                  * present. The `m_tag_id' field is used as
2876                                  * stack pointer.
2877                                  */
2878                                 struct m_tag *mtag;
2879                                 uint16_t jmpto, *stack;
2880
2881 #define IS_CALL         ((cmd->len & F_NOT) == 0)
2882 #define IS_RETURN       ((cmd->len & F_NOT) != 0)
2883                                 /*
2884                                  * Hand-rolled version of m_tag_locate() with
2885                                  * wildcard `type'.
2886                                  * If not already tagged, allocate new tag.
2887                                  */
2888                                 mtag = m_tag_first(m);
2889                                 while (mtag != NULL) {
2890                                         if (mtag->m_tag_cookie ==
2891                                             MTAG_IPFW_CALL)
2892                                                 break;
2893                                         mtag = m_tag_next(m, mtag);
2894                                 }
2895                                 if (mtag == NULL && IS_CALL) {
2896                                         mtag = m_tag_alloc(MTAG_IPFW_CALL, 0,
2897                                             IPFW_CALLSTACK_SIZE *
2898                                             sizeof(uint16_t), M_NOWAIT);
2899                                         if (mtag != NULL)
2900                                                 m_tag_prepend(m, mtag);
2901                                 }
2902
2903                                 /*
2904                                  * On error both `call' and `return' just
2905                                  * continue with next rule.
2906                                  */
2907                                 if (IS_RETURN && (mtag == NULL ||
2908                                     mtag->m_tag_id == 0)) {
2909                                         l = 0;          /* exit inner loop */
2910                                         break;
2911                                 }
2912                                 if (IS_CALL && (mtag == NULL ||
2913                                     mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) {
2914                                         printf("ipfw: call stack error, "
2915                                             "go to next rule\n");
2916                                         l = 0;          /* exit inner loop */
2917                                         break;
2918                                 }
2919
2920                                 IPFW_INC_RULE_COUNTER(f, pktlen);
2921                                 stack = (uint16_t *)(mtag + 1);
2922
2923                                 /*
2924                                  * The `call' action may use cached f_pos
2925                                  * (in f->next_rule), whose version is written
2926                                  * in f->next_rule.
2927                                  * The `return' action, however, doesn't have
2928                                  * fixed jump address in cmd->arg1 and can't use
2929                                  * cache.
2930                                  */
2931                                 if (IS_CALL) {
2932                                         stack[mtag->m_tag_id] = f->rulenum;
2933                                         mtag->m_tag_id++;
2934                                         f_pos = JUMP(chain, f, cmd->arg1,
2935                                             tablearg, 1);
2936                                 } else {        /* `return' action */
2937                                         mtag->m_tag_id--;
2938                                         jmpto = stack[mtag->m_tag_id] + 1;
2939                                         f_pos = ipfw_find_rule(chain, jmpto, 0);
2940                                 }
2941
2942                                 /*
2943                                  * Skip disabled rules, and re-enter
2944                                  * the inner loop with the correct
2945                                  * f_pos, f, l and cmd.
2946                                  * Also clear cmdlen and skip_or
2947                                  */
2948                                 for (; f_pos < chain->n_rules - 1 &&
2949                                     (V_set_disable &
2950                                     (1 << chain->map[f_pos]->set)); f_pos++)
2951                                         ;
2952                                 /* Re-enter the inner loop at the dest rule. */
2953                                 f = chain->map[f_pos];
2954                                 l = f->cmd_len;
2955                                 cmd = f->cmd;
2956                                 cmdlen = 0;
2957                                 skip_or = 0;
2958                                 continue;
2959                                 break;  /* NOTREACHED */
2960                         }
2961 #undef IS_CALL
2962 #undef IS_RETURN
2963
2964                         case O_REJECT:
2965                                 /*
2966                                  * Drop the packet and send a reject notice
2967                                  * if the packet is not ICMP (or is an ICMP
2968                                  * query), and it is not multicast/broadcast.
2969                                  */
2970                                 if (hlen > 0 && is_ipv4 && offset == 0 &&
2971                                     (proto != IPPROTO_ICMP ||
2972                                      is_icmp_query(ICMP(ulp))) &&
2973                                     !(m->m_flags & (M_BCAST|M_MCAST)) &&
2974                                     !IN_MULTICAST(ntohl(dst_ip.s_addr))) {
2975                                         send_reject(args, cmd->arg1, iplen, ip);
2976                                         m = args->m;
2977                                 }
2978                                 /* FALLTHROUGH */
2979 #ifdef INET6
2980                         case O_UNREACH6:
2981                                 if (hlen > 0 && is_ipv6 &&
2982                                     ((offset & IP6F_OFF_MASK) == 0) &&
2983                                     (proto != IPPROTO_ICMPV6 ||
2984                                      (is_icmp6_query(icmp6_type) == 1)) &&
2985                                     !(m->m_flags & (M_BCAST|M_MCAST)) &&
2986                                     !IN6_IS_ADDR_MULTICAST(
2987                                         &args->f_id.dst_ip6)) {
2988                                         send_reject6(args,
2989                                             cmd->opcode == O_REJECT ?
2990                                             map_icmp_unreach(cmd->arg1):
2991                                             cmd->arg1, hlen,
2992                                             (struct ip6_hdr *)ip);
2993                                         m = args->m;
2994                                 }
2995                                 /* FALLTHROUGH */
2996 #endif
2997                         case O_DENY:
2998                                 retval = IP_FW_DENY;
2999                                 l = 0;          /* exit inner loop */
3000                                 done = 1;       /* exit outer loop */
3001                                 break;
3002
3003                         case O_FORWARD_IP:
3004                                 if (args->flags & IPFW_ARGS_ETHER)
3005                                         break;  /* not valid on layer2 pkts */
3006                                 if (q != f ||
3007                                     dyn_info.direction == MATCH_FORWARD) {
3008                                     struct sockaddr_in *sa;
3009
3010                                     sa = &(((ipfw_insn_sa *)cmd)->sa);
3011                                     if (sa->sin_addr.s_addr == INADDR_ANY) {
3012 #ifdef INET6
3013                                         /*
3014                                          * We use O_FORWARD_IP opcode for
3015                                          * fwd rule with tablearg, but tables
3016                                          * now support IPv6 addresses. And
3017                                          * when we are inspecting IPv6 packet,
3018                                          * we can use nh6 field from
3019                                          * table_value as next_hop6 address.
3020                                          */
3021                                         if (is_ipv6) {
3022                                                 struct ip_fw_nh6 *nh6;
3023
3024                                                 args->flags |= IPFW_ARGS_NH6;
3025                                                 nh6 = &args->hopstore6;
3026                                                 nh6->sin6_addr = TARG_VAL(
3027                                                     chain, tablearg, nh6);
3028                                                 nh6->sin6_port = sa->sin_port;
3029                                                 nh6->sin6_scope_id = TARG_VAL(
3030                                                     chain, tablearg, zoneid);
3031                                         } else
3032 #endif
3033                                         {
3034                                                 args->flags |= IPFW_ARGS_NH4;
3035                                                 args->hopstore.sin_port =
3036                                                     sa->sin_port;
3037                                                 sa = &args->hopstore;
3038                                                 sa->sin_family = AF_INET;
3039                                                 sa->sin_len = sizeof(*sa);
3040                                                 sa->sin_addr.s_addr = htonl(
3041                                                     TARG_VAL(chain, tablearg,
3042                                                     nh4));
3043                                         }
3044                                     } else {
3045                                             args->flags |= IPFW_ARGS_NH4PTR;
3046                                             args->next_hop = sa;
3047                                     }
3048                                 }
3049                                 retval = IP_FW_PASS;
3050                                 l = 0;          /* exit inner loop */
3051                                 done = 1;       /* exit outer loop */
3052                                 break;
3053
3054 #ifdef INET6
3055                         case O_FORWARD_IP6:
3056                                 if (args->flags & IPFW_ARGS_ETHER)
3057                                         break;  /* not valid on layer2 pkts */
3058                                 if (q != f ||
3059                                     dyn_info.direction == MATCH_FORWARD) {
3060                                         struct sockaddr_in6 *sin6;
3061
3062                                         sin6 = &(((ipfw_insn_sa6 *)cmd)->sa);
3063                                         args->flags |= IPFW_ARGS_NH6PTR;
3064                                         args->next_hop6 = sin6;
3065                                 }
3066                                 retval = IP_FW_PASS;
3067                                 l = 0;          /* exit inner loop */
3068                                 done = 1;       /* exit outer loop */
3069                                 break;
3070 #endif
3071
3072                         case O_NETGRAPH:
3073                         case O_NGTEE:
3074                                 set_match(args, f_pos, chain);
3075                                 args->rule.info = TARG(cmd->arg1, netgraph);
3076                                 if (V_fw_one_pass)
3077                                         args->rule.info |= IPFW_ONEPASS;
3078                                 retval = (cmd->opcode == O_NETGRAPH) ?
3079                                     IP_FW_NETGRAPH : IP_FW_NGTEE;
3080                                 l = 0;          /* exit inner loop */
3081                                 done = 1;       /* exit outer loop */
3082                                 break;
3083
3084                         case O_SETFIB: {
3085                                 uint32_t fib;
3086
3087                                 IPFW_INC_RULE_COUNTER(f, pktlen);
3088                                 fib = TARG(cmd->arg1, fib) & 0x7FFF;
3089                                 if (fib >= rt_numfibs)
3090                                         fib = 0;
3091                                 M_SETFIB(m, fib);
3092                                 args->f_id.fib = fib; /* XXX */
3093                                 l = 0;          /* exit inner loop */
3094                                 break;
3095                         }
3096
3097                         case O_SETDSCP: {
3098                                 uint16_t code;
3099
3100                                 code = TARG(cmd->arg1, dscp) & 0x3F;
3101                                 l = 0;          /* exit inner loop */
3102                                 if (is_ipv4) {
3103                                         uint16_t old;
3104
3105                                         old = *(uint16_t *)ip;
3106                                         ip->ip_tos = (code << 2) |
3107                                             (ip->ip_tos & 0x03);
3108                                         ip->ip_sum = cksum_adjust(ip->ip_sum,
3109                                             old, *(uint16_t *)ip);
3110                                 } else if (is_ipv6) {
3111                                         uint8_t *v;
3112
3113                                         v = &((struct ip6_hdr *)ip)->ip6_vfc;
3114                                         *v = (*v & 0xF0) | (code >> 2);
3115                                         v++;
3116                                         *v = (*v & 0x3F) | ((code & 0x03) << 6);
3117                                 } else
3118                                         break;
3119
3120                                 IPFW_INC_RULE_COUNTER(f, pktlen);
3121                                 break;
3122                         }
3123
3124                         case O_NAT:
3125                                 l = 0;          /* exit inner loop */
3126                                 done = 1;       /* exit outer loop */
3127                                 /*
3128                                  * Ensure that we do not invoke NAT handler for
3129                                  * non IPv4 packets. Libalias expects only IPv4.
3130                                  */
3131                                 if (!is_ipv4 || !IPFW_NAT_LOADED) {
3132                                     retval = IP_FW_DENY;
3133                                     break;
3134                                 }
3135
3136                                 struct cfg_nat *t;
3137                                 int nat_id;
3138
3139                                 args->rule.info = 0;
3140                                 set_match(args, f_pos, chain);
3141                                 /* Check if this is 'global' nat rule */
3142                                 if (cmd->arg1 == IP_FW_NAT44_GLOBAL) {
3143                                         retval = ipfw_nat_ptr(args, NULL, m);
3144                                         break;
3145                                 }
3146                                 t = ((ipfw_insn_nat *)cmd)->nat;
3147                                 if (t == NULL) {
3148                                         nat_id = TARG(cmd->arg1, nat);
3149                                         t = (*lookup_nat_ptr)(&chain->nat, nat_id);
3150
3151                                         if (t == NULL) {
3152                                             retval = IP_FW_DENY;
3153                                             break;
3154                                         }
3155                                         if (cmd->arg1 != IP_FW_TARG)
3156                                             ((ipfw_insn_nat *)cmd)->nat = t;
3157                                 }
3158                                 retval = ipfw_nat_ptr(args, t, m);
3159                                 break;
3160
3161                         case O_REASS: {
3162                                 int ip_off;
3163
3164                                 l = 0;  /* in any case exit inner loop */
3165                                 if (is_ipv6) /* IPv6 is not supported yet */
3166                                         break;
3167                                 IPFW_INC_RULE_COUNTER(f, pktlen);
3168                                 ip_off = ntohs(ip->ip_off);
3169
3170                                 /* if not fragmented, go to next rule */
3171                                 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0)
3172                                     break;
3173
3174                                 args->m = m = ip_reass(m);
3175
3176                                 /*
3177                                  * do IP header checksum fixup.
3178                                  */
3179                                 if (m == NULL) { /* fragment got swallowed */
3180                                     retval = IP_FW_DENY;
3181                                 } else { /* good, packet complete */
3182                                     int hlen;
3183
3184                                     ip = mtod(m, struct ip *);
3185                                     hlen = ip->ip_hl << 2;
3186                                     ip->ip_sum = 0;
3187                                     if (hlen == sizeof(struct ip))
3188                                         ip->ip_sum = in_cksum_hdr(ip);
3189                                     else
3190                                         ip->ip_sum = in_cksum(m, hlen);
3191                                     retval = IP_FW_REASS;
3192                                     args->rule.info = 0;
3193                                     set_match(args, f_pos, chain);
3194                                 }
3195                                 done = 1;       /* exit outer loop */
3196                                 break;
3197                         }
3198                         case O_EXTERNAL_ACTION:
3199                                 l = 0; /* in any case exit inner loop */
3200                                 retval = ipfw_run_eaction(chain, args,
3201                                     cmd, &done);
3202                                 /*
3203                                  * If both @retval and @done are zero,
3204                                  * consider this as rule matching and
3205                                  * update counters.
3206                                  */
3207                                 if (retval == 0 && done == 0) {
3208                                         IPFW_INC_RULE_COUNTER(f, pktlen);
3209                                         /*
3210                                          * Reset the result of the last
3211                                          * dynamic state lookup.
3212                                          * External action can change
3213                                          * @args content, and it may be
3214                                          * used for new state lookup later.
3215                                          */
3216                                         DYN_INFO_INIT(&dyn_info);
3217                                 }
3218                                 break;
3219
3220                         default:
3221                                 panic("-- unknown opcode %d\n", cmd->opcode);
3222                         } /* end of switch() on opcodes */
3223                         /*
3224                          * if we get here with l=0, then match is irrelevant.
3225                          */
3226
3227                         if (cmd->len & F_NOT)
3228                                 match = !match;
3229
3230                         if (match) {
3231                                 if (cmd->len & F_OR)
3232                                         skip_or = 1;
3233                         } else {
3234                                 if (!(cmd->len & F_OR)) /* not an OR block, */
3235                                         break;          /* try next rule    */
3236                         }
3237
3238                 }       /* end of inner loop, scan opcodes */
3239 #undef PULLUP_LEN
3240 #undef PULLUP_LEN_LOCKED
3241
3242                 if (done)
3243                         break;
3244
3245 /* next_rule:; */       /* try next rule                */
3246
3247         }               /* end of outer for, scan rules */
3248
3249         if (done) {
3250                 struct ip_fw *rule = chain->map[f_pos];
3251                 /* Update statistics */
3252                 IPFW_INC_RULE_COUNTER(rule, pktlen);
3253                 IPFW_PROBE(rule__matched, retval,
3254                     is_ipv4 ? AF_INET : AF_INET6,
3255                     is_ipv4 ? (uintptr_t)&src_ip :
3256                         (uintptr_t)&args->f_id.src_ip6,
3257                     is_ipv4 ? (uintptr_t)&dst_ip :
3258                         (uintptr_t)&args->f_id.dst_ip6,
3259                     args, rule);
3260         } else {
3261                 retval = IP_FW_DENY;
3262                 printf("ipfw: ouch!, skip past end of rules, denying packet\n");
3263         }
3264         IPFW_PF_RUNLOCK(chain);
3265 #ifdef __FreeBSD__
3266         if (ucred_cache != NULL)
3267                 crfree(ucred_cache);
3268 #endif
3269         return (retval);
3270
3271 pullup_failed:
3272         if (V_fw_verbose)
3273                 printf("ipfw: pullup failed\n");
3274         return (IP_FW_DENY);
3275 }
3276
3277 /*
3278  * Set maximum number of tables that can be used in given VNET ipfw instance.
3279  */
3280 #ifdef SYSCTL_NODE
3281 static int
3282 sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS)
3283 {
3284         int error;
3285         unsigned int ntables;
3286
3287         ntables = V_fw_tables_max;
3288
3289         error = sysctl_handle_int(oidp, &ntables, 0, req);
3290         /* Read operation or some error */
3291         if ((error != 0) || (req->newptr == NULL))
3292                 return (error);
3293
3294         return (ipfw_resize_tables(&V_layer3_chain, ntables));
3295 }
3296
3297 /*
3298  * Switches table namespace between global and per-set.
3299  */
3300 static int
3301 sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS)
3302 {
3303         int error;
3304         unsigned int sets;
3305
3306         sets = V_fw_tables_sets;
3307
3308         error = sysctl_handle_int(oidp, &sets, 0, req);
3309         /* Read operation or some error */
3310         if ((error != 0) || (req->newptr == NULL))
3311                 return (error);
3312
3313         return (ipfw_switch_tables_namespace(&V_layer3_chain, sets));
3314 }
3315 #endif
3316
3317 /*
3318  * Module and VNET glue
3319  */
3320
3321 /*
3322  * Stuff that must be initialised only on boot or module load
3323  */
3324 static int
3325 ipfw_init(void)
3326 {
3327         int error = 0;
3328
3329         /*
3330          * Only print out this stuff the first time around,
3331          * when called from the sysinit code.
3332          */
3333         printf("ipfw2 "
3334 #ifdef INET6
3335                 "(+ipv6) "
3336 #endif
3337                 "initialized, divert %s, nat %s, "
3338                 "default to %s, logging ",
3339 #ifdef IPDIVERT
3340                 "enabled",
3341 #else
3342                 "loadable",
3343 #endif
3344 #ifdef IPFIREWALL_NAT
3345                 "enabled",
3346 #else
3347                 "loadable",
3348 #endif
3349                 default_to_accept ? "accept" : "deny");
3350
3351         /*
3352          * Note: V_xxx variables can be accessed here but the vnet specific
3353          * initializer may not have been called yet for the VIMAGE case.
3354          * Tuneables will have been processed. We will print out values for
3355          * the default vnet.
3356          * XXX This should all be rationalized AFTER 8.0
3357          */
3358         if (V_fw_verbose == 0)
3359                 printf("disabled\n");
3360         else if (V_verbose_limit == 0)
3361                 printf("unlimited\n");
3362         else
3363                 printf("limited to %d packets/entry by default\n",
3364                     V_verbose_limit);
3365
3366         /* Check user-supplied table count for validness */
3367         if (default_fw_tables > IPFW_TABLES_MAX)
3368           default_fw_tables = IPFW_TABLES_MAX;
3369
3370         ipfw_init_sopt_handler();
3371         ipfw_init_obj_rewriter();
3372         ipfw_iface_init();
3373         return (error);
3374 }
3375
3376 /*
3377  * Called for the removal of the last instance only on module unload.
3378  */
3379 static void
3380 ipfw_destroy(void)
3381 {
3382
3383         ipfw_iface_destroy();
3384         ipfw_destroy_sopt_handler();
3385         ipfw_destroy_obj_rewriter();
3386         printf("IP firewall unloaded\n");
3387 }
3388
3389 /*
3390  * Stuff that must be initialized for every instance
3391  * (including the first of course).
3392  */
3393 static int
3394 vnet_ipfw_init(const void *unused)
3395 {
3396         int error, first;
3397         struct ip_fw *rule = NULL;
3398         struct ip_fw_chain *chain;
3399
3400         chain = &V_layer3_chain;
3401
3402         first = IS_DEFAULT_VNET(curvnet) ? 1 : 0;
3403
3404         /* First set up some values that are compile time options */
3405         V_autoinc_step = 100;   /* bounded to 1..1000 in add_rule() */
3406         V_fw_deny_unknown_exthdrs = 1;
3407 #ifdef IPFIREWALL_VERBOSE
3408         V_fw_verbose = 1;
3409 #endif
3410 #ifdef IPFIREWALL_VERBOSE_LIMIT
3411         V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
3412 #endif
3413 #ifdef IPFIREWALL_NAT
3414         LIST_INIT(&chain->nat);
3415 #endif
3416
3417         /* Init shared services hash table */
3418         ipfw_init_srv(chain);
3419
3420         ipfw_init_counters();
3421         /* Set initial number of tables */
3422         V_fw_tables_max = default_fw_tables;
3423         error = ipfw_init_tables(chain, first);
3424         if (error) {
3425                 printf("ipfw2: setting up tables failed\n");
3426                 free(chain->map, M_IPFW);
3427                 free(rule, M_IPFW);
3428                 return (ENOSPC);
3429         }
3430
3431         IPFW_LOCK_INIT(chain);
3432
3433         /* fill and insert the default rule */
3434         rule = ipfw_alloc_rule(chain, sizeof(struct ip_fw));
3435         rule->flags |= IPFW_RULE_NOOPT;
3436         rule->cmd_len = 1;
3437         rule->cmd[0].len = 1;
3438         rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY;
3439         chain->default_rule = rule;
3440         ipfw_add_protected_rule(chain, rule, 0);
3441
3442         ipfw_dyn_init(chain);
3443         ipfw_eaction_init(chain, first);
3444 #ifdef LINEAR_SKIPTO
3445         ipfw_init_skipto_cache(chain);
3446 #endif
3447         ipfw_bpf_init(first);
3448
3449         /* First set up some values that are compile time options */
3450         V_ipfw_vnet_ready = 1;          /* Open for business */
3451
3452         /*
3453          * Hook the sockopt handler and pfil hooks for ipv4 and ipv6.
3454          * Even if the latter two fail we still keep the module alive
3455          * because the sockopt and layer2 paths are still useful.
3456          * ipfw[6]_hook return 0 on success, ENOENT on failure,
3457          * so we can ignore the exact return value and just set a flag.
3458          *
3459          * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so
3460          * changes in the underlying (per-vnet) variables trigger
3461          * immediate hook()/unhook() calls.
3462          * In layer2 we have the same behaviour, except that V_ether_ipfw
3463          * is checked on each packet because there are no pfil hooks.
3464          */
3465         V_ip_fw_ctl_ptr = ipfw_ctl3;
3466         error = ipfw_attach_hooks();
3467         return (error);
3468 }
3469
3470 /*
3471  * Called for the removal of each instance.
3472  */
3473 static int
3474 vnet_ipfw_uninit(const void *unused)
3475 {
3476         struct ip_fw *reap;
3477         struct ip_fw_chain *chain = &V_layer3_chain;
3478         int i, last;
3479
3480         V_ipfw_vnet_ready = 0; /* tell new callers to go away */
3481         /*
3482          * disconnect from ipv4, ipv6, layer2 and sockopt.
3483          * Then grab, release and grab again the WLOCK so we make
3484          * sure the update is propagated and nobody will be in.
3485          */
3486         ipfw_detach_hooks();
3487         V_ip_fw_ctl_ptr = NULL;
3488
3489         last = IS_DEFAULT_VNET(curvnet) ? 1 : 0;
3490
3491         IPFW_UH_WLOCK(chain);
3492         IPFW_UH_WUNLOCK(chain);
3493
3494         ipfw_dyn_uninit(0);     /* run the callout_drain */
3495
3496         IPFW_UH_WLOCK(chain);
3497
3498         reap = NULL;
3499         IPFW_WLOCK(chain);
3500         for (i = 0; i < chain->n_rules; i++)
3501                 ipfw_reap_add(chain, &reap, chain->map[i]);
3502         free(chain->map, M_IPFW);
3503 #ifdef LINEAR_SKIPTO
3504         ipfw_destroy_skipto_cache(chain);
3505 #endif
3506         IPFW_WUNLOCK(chain);
3507         IPFW_UH_WUNLOCK(chain);
3508         ipfw_destroy_tables(chain, last);
3509         ipfw_eaction_uninit(chain, last);
3510         if (reap != NULL)
3511                 ipfw_reap_rules(reap);
3512         vnet_ipfw_iface_destroy(chain);
3513         ipfw_destroy_srv(chain);
3514         IPFW_LOCK_DESTROY(chain);
3515         ipfw_dyn_uninit(1);     /* free the remaining parts */
3516         ipfw_destroy_counters();
3517         ipfw_bpf_uninit(last);
3518         return (0);
3519 }
3520
3521 /*
3522  * Module event handler.
3523  * In general we have the choice of handling most of these events by the
3524  * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to
3525  * use the SYSINIT handlers as they are more capable of expressing the
3526  * flow of control during module and vnet operations, so this is just
3527  * a skeleton. Note there is no SYSINIT equivalent of the module
3528  * SHUTDOWN handler, but we don't have anything to do in that case anyhow.
3529  */
3530 static int
3531 ipfw_modevent(module_t mod, int type, void *unused)
3532 {
3533         int err = 0;
3534
3535         switch (type) {
3536         case MOD_LOAD:
3537                 /* Called once at module load or
3538                  * system boot if compiled in. */
3539                 break;
3540         case MOD_QUIESCE:
3541                 /* Called before unload. May veto unloading. */
3542                 break;
3543         case MOD_UNLOAD:
3544                 /* Called during unload. */
3545                 break;
3546         case MOD_SHUTDOWN:
3547                 /* Called during system shutdown. */
3548                 break;
3549         default:
3550                 err = EOPNOTSUPP;
3551                 break;
3552         }
3553         return err;
3554 }
3555
3556 static moduledata_t ipfwmod = {
3557         "ipfw",
3558         ipfw_modevent,
3559         0
3560 };
3561
3562 /* Define startup order. */
3563 #define IPFW_SI_SUB_FIREWALL    SI_SUB_PROTO_FIREWALL
3564 #define IPFW_MODEVENT_ORDER     (SI_ORDER_ANY - 255) /* On boot slot in here. */
3565 #define IPFW_MODULE_ORDER       (IPFW_MODEVENT_ORDER + 1) /* A little later. */
3566 #define IPFW_VNET_ORDER         (IPFW_MODEVENT_ORDER + 2) /* Later still. */
3567
3568 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER);
3569 FEATURE(ipfw_ctl3, "ipfw new sockopt calls");
3570 MODULE_VERSION(ipfw, 3);
3571 /* should declare some dependencies here */
3572
3573 /*
3574  * Starting up. Done in order after ipfwmod() has been called.
3575  * VNET_SYSINIT is also called for each existing vnet and each new vnet.
3576  */
3577 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
3578             ipfw_init, NULL);
3579 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
3580             vnet_ipfw_init, NULL);
3581
3582 /*
3583  * Closing up shop. These are done in REVERSE ORDER, but still
3584  * after ipfwmod() has been called. Not called on reboot.
3585  * VNET_SYSUNINIT is also called for each exiting vnet as it exits.
3586  * or when the module is unloaded.
3587  */
3588 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
3589             ipfw_destroy, NULL);
3590 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
3591             vnet_ipfw_uninit, NULL);
3592 /* end of file */