sys/netpfil/ipfw/ip_fw2.c

   1 /*-
   2  * Copyright (c) 2002-2009 Luigi Rizzo, Universita` di Pisa
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  23  * SUCH DAMAGE.
  24  */
  25
  26 #include <sys/cdefs.h>
  27 __FBSDID("$FreeBSD$");
  28
  29 /*
  30  * The FreeBSD IP packet firewall, main file
  31  */
  32
  33 #include "opt_ipfw.h"
  34 #include "opt_ipdivert.h"
  35 #include "opt_inet.h"
  36 #ifndef INET
  37 #error "IPFIREWALL requires INET"
  38 #endif /* INET */
  39 #include "opt_inet6.h"
  40 #include "opt_ipsec.h"
  41
  42 #include <sys/param.h>
  43 #include <sys/systm.h>
  44 #include <sys/condvar.h>
  45 #include <sys/counter.h>
  46 #include <sys/eventhandler.h>
  47 #include <sys/malloc.h>
  48 #include <sys/mbuf.h>
  49 #include <sys/kernel.h>
  50 #include <sys/lock.h>
  51 #include <sys/jail.h>
  52 #include <sys/module.h>
  53 #include <sys/priv.h>
  54 #include <sys/proc.h>
  55 #include <sys/rwlock.h>
  56 #include <sys/rmlock.h>
  57 #include <sys/socket.h>
  58 #include <sys/socketvar.h>
  59 #include <sys/sysctl.h>
  60 #include <sys/syslog.h>
  61 #include <sys/ucred.h>
  62 #include <net/ethernet.h> /* for ETHERTYPE_IP */
  63 #include <net/if.h>
  64 #include <net/if_var.h>
  65 #include <net/route.h>
  66 #include <net/pfil.h>
  67 #include <net/vnet.h>
  68
  69 #include <netpfil/pf/pf_mtag.h>
  70
  71 #include <netinet/in.h>
  72 #include <netinet/in_var.h>
  73 #include <netinet/in_pcb.h>
  74 #include <netinet/ip.h>
  75 #include <netinet/ip_var.h>
  76 #include <netinet/ip_icmp.h>
  77 #include <netinet/ip_fw.h>
  78 #include <netinet/ip_carp.h>
  79 #include <netinet/pim.h>
  80 #include <netinet/tcp_var.h>
  81 #include <netinet/udp.h>
  82 #include <netinet/udp_var.h>
  83 #include <netinet/sctp.h>
  84
  85 #include <netinet/ip6.h>
  86 #include <netinet/icmp6.h>
  87 #include <netinet/in_fib.h>
  88 #ifdef INET6
  89 #include <netinet6/in6_fib.h>
  90 #include <netinet6/in6_pcb.h>
  91 #include <netinet6/scope6_var.h>
  92 #include <netinet6/ip6_var.h>
  93 #endif
  94
  95 #include <netpfil/ipfw/ip_fw_private.h>
  96
  97 #include <machine/in_cksum.h>   /* XXX for in_cksum */
  98
  99 #ifdef MAC
 100 #include <security/mac/mac_framework.h>
 101 #endif
 102
 103 /*
 104  * static variables followed by global ones.
 105  * All ipfw global variables are here.
 106  */
 107
 108 static VNET_DEFINE(int, fw_deny_unknown_exthdrs);
 109 #define V_fw_deny_unknown_exthdrs       VNET(fw_deny_unknown_exthdrs)
 110
 111 static VNET_DEFINE(int, fw_permit_single_frag6) = 1;
 112 #define V_fw_permit_single_frag6        VNET(fw_permit_single_frag6)
 113
 114 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
 115 static int default_to_accept = 1;
 116 #else
 117 static int default_to_accept;
 118 #endif
 119
 120 VNET_DEFINE(int, autoinc_step);
 121 VNET_DEFINE(int, fw_one_pass) = 1;
 122
 123 VNET_DEFINE(unsigned int, fw_tables_max);
 124 VNET_DEFINE(unsigned int, fw_tables_sets) = 0;  /* Don't use set-aware tables */
 125 /* Use 128 tables by default */
 126 static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT;
 127
 128 #ifndef LINEAR_SKIPTO
 129 static int jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num,
 130     int tablearg, int jump_backwards);
 131 #define JUMP(ch, f, num, targ, back)    jump_fast(ch, f, num, targ, back)
 132 #else
 133 static int jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num,
 134     int tablearg, int jump_backwards);
 135 #define JUMP(ch, f, num, targ, back)    jump_linear(ch, f, num, targ, back)
 136 #endif
 137
 138 /*
 139  * Each rule belongs to one of 32 different sets (0..31).
 140  * The variable set_disable contains one bit per set.
 141  * If the bit is set, all rules in the corresponding set
 142  * are disabled. Set RESVD_SET(31) is reserved for the default rule
 143  * and rules that are not deleted by the flush command,
 144  * and CANNOT be disabled.
 145  * Rules in set RESVD_SET can only be deleted individually.
 146  */
 147 VNET_DEFINE(u_int32_t, set_disable);
 148 #define V_set_disable                   VNET(set_disable)
 149
 150 VNET_DEFINE(int, fw_verbose);
 151 /* counter for ipfw_log(NULL...) */
 152 VNET_DEFINE(u_int64_t, norule_counter);
 153 VNET_DEFINE(int, verbose_limit);
 154
 155 /* layer3_chain contains the list of rules for layer 3 */
 156 VNET_DEFINE(struct ip_fw_chain, layer3_chain);
 157
 158 /* ipfw_vnet_ready controls when we are open for business */
 159 VNET_DEFINE(int, ipfw_vnet_ready) = 0;
 160
 161 VNET_DEFINE(int, ipfw_nat_ready) = 0;
 162
 163 ipfw_nat_t *ipfw_nat_ptr = NULL;
 164 struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int);
 165 ipfw_nat_cfg_t *ipfw_nat_cfg_ptr;
 166 ipfw_nat_cfg_t *ipfw_nat_del_ptr;
 167 ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr;
 168 ipfw_nat_cfg_t *ipfw_nat_get_log_ptr;
 169
 170 #ifdef SYSCTL_NODE
 171 uint32_t dummy_def = IPFW_DEFAULT_RULE;
 172 static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS);
 173 static int sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS);
 174
 175 SYSBEGIN(f3)
 176
 177 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
 178 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass,
 179     CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0,
 180     "Only do a single pass through ipfw when using dummynet(4)");
 181 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step,
 182     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(autoinc_step), 0,
 183     "Rule number auto-increment step");
 184 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose,
 185     CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0,
 186     "Log matches to ipfw rules");
 187 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit,
 188     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(verbose_limit), 0,
 189     "Set upper limit of matches of ipfw rules logged");
 190 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD,
 191     &dummy_def, 0,
 192     "The default/max possible rule number.");
 193 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_max,
 194     CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, 0, 0, sysctl_ipfw_table_num, "IU",
 195     "Maximum number of concurrently used tables");
 196 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_sets,
 197     CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW,
 198     0, 0, sysctl_ipfw_tables_sets, "IU",
 199     "Use per-set namespace for tables");
 200 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN,
 201     &default_to_accept, 0,
 202     "Make the default rule accept all packets.");
 203 TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables);
 204 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count,
 205     CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0,
 206     "Number of static rules");
 207
 208 #ifdef INET6
 209 SYSCTL_DECL(_net_inet6_ip6);
 210 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
 211 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs,
 212     CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE,
 213     &VNET_NAME(fw_deny_unknown_exthdrs), 0,
 214     "Deny packets with unknown IPv6 Extension Headers");
 215 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6,
 216     CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE,
 217     &VNET_NAME(fw_permit_single_frag6), 0,
 218     "Permit single packet IPv6 fragments");
 219 #endif /* INET6 */
 220
 221 SYSEND
 222
 223 #endif /* SYSCTL_NODE */
 224
 225
 226 /*
 227  * Some macros used in the various matching options.
 228  * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T
 229  * Other macros just cast void * into the appropriate type
 230  */
 231 #define L3HDR(T, ip)    ((T *)((u_int32_t *)(ip) + (ip)->ip_hl))
 232 #define TCP(p)          ((struct tcphdr *)(p))
 233 #define SCTP(p)         ((struct sctphdr *)(p))
 234 #define UDP(p)          ((struct udphdr *)(p))
 235 #define ICMP(p)         ((struct icmphdr *)(p))
 236 #define ICMP6(p)        ((struct icmp6_hdr *)(p))
 237
 238 static __inline int
 239 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd)
 240 {
 241         int type = icmp->icmp_type;
 242
 243         return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) );
 244 }
 245
 246 #define TT      ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \
 247     (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) )
 248
 249 static int
 250 is_icmp_query(struct icmphdr *icmp)
 251 {
 252         int type = icmp->icmp_type;
 253
 254         return (type <= ICMP_MAXTYPE && (TT & (1<<type)) );
 255 }
 256 #undef TT
 257
 258 /*
 259  * The following checks use two arrays of 8 or 16 bits to store the
 260  * bits that we want set or clear, respectively. They are in the
 261  * low and high half of cmd->arg1 or cmd->d[0].
 262  *
 263  * We scan options and store the bits we find set. We succeed if
 264  *
 265  *      (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear
 266  *
 267  * The code is sometimes optimized not to store additional variables.
 268  */
 269
 270 static int
 271 flags_match(ipfw_insn *cmd, u_int8_t bits)
 272 {
 273         u_char want_clear;
 274         bits = ~bits;
 275
 276         if ( ((cmd->arg1 & 0xff) & bits) != 0)
 277                 return 0; /* some bits we want set were clear */
 278         want_clear = (cmd->arg1 >> 8) & 0xff;
 279         if ( (want_clear & bits) != want_clear)
 280                 return 0; /* some bits we want clear were set */
 281         return 1;
 282 }
 283
 284 static int
 285 ipopts_match(struct ip *ip, ipfw_insn *cmd)
 286 {
 287         int optlen, bits = 0;
 288         u_char *cp = (u_char *)(ip + 1);
 289         int x = (ip->ip_hl << 2) - sizeof (struct ip);
 290
 291         for (; x > 0; x -= optlen, cp += optlen) {
 292                 int opt = cp[IPOPT_OPTVAL];
 293
 294                 if (opt == IPOPT_EOL)
 295                         break;
 296                 if (opt == IPOPT_NOP)
 297                         optlen = 1;
 298                 else {
 299                         optlen = cp[IPOPT_OLEN];
 300                         if (optlen <= 0 || optlen > x)
 301                                 return 0; /* invalid or truncated */
 302                 }
 303                 switch (opt) {
 304
 305                 default:
 306                         break;
 307
 308                 case IPOPT_LSRR:
 309                         bits |= IP_FW_IPOPT_LSRR;
 310                         break;
 311
 312                 case IPOPT_SSRR:
 313                         bits |= IP_FW_IPOPT_SSRR;
 314                         break;
 315
 316                 case IPOPT_RR:
 317                         bits |= IP_FW_IPOPT_RR;
 318                         break;
 319
 320                 case IPOPT_TS:
 321                         bits |= IP_FW_IPOPT_TS;
 322                         break;
 323                 }
 324         }
 325         return (flags_match(cmd, bits));
 326 }
 327
 328 static int
 329 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd)
 330 {
 331         int optlen, bits = 0;
 332         u_char *cp = (u_char *)(tcp + 1);
 333         int x = (tcp->th_off << 2) - sizeof(struct tcphdr);
 334
 335         for (; x > 0; x -= optlen, cp += optlen) {
 336                 int opt = cp[0];
 337                 if (opt == TCPOPT_EOL)
 338                         break;
 339                 if (opt == TCPOPT_NOP)
 340                         optlen = 1;
 341                 else {
 342                         optlen = cp[1];
 343                         if (optlen <= 0)
 344                                 break;
 345                 }
 346
 347                 switch (opt) {
 348
 349                 default:
 350                         break;
 351
 352                 case TCPOPT_MAXSEG:
 353                         bits |= IP_FW_TCPOPT_MSS;
 354                         break;
 355
 356                 case TCPOPT_WINDOW:
 357                         bits |= IP_FW_TCPOPT_WINDOW;
 358                         break;
 359
 360                 case TCPOPT_SACK_PERMITTED:
 361                 case TCPOPT_SACK:
 362                         bits |= IP_FW_TCPOPT_SACK;
 363                         break;
 364
 365                 case TCPOPT_TIMESTAMP:
 366                         bits |= IP_FW_TCPOPT_TS;
 367                         break;
 368
 369                 }
 370         }
 371         return (flags_match(cmd, bits));
 372 }
 373
 374 static int
 375 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain,
 376     uint32_t *tablearg)
 377 {
 378
 379         if (ifp == NULL)        /* no iface with this packet, match fails */
 380                 return (0);
 381
 382         /* Check by name or by IP address */
 383         if (cmd->name[0] != '\0') { /* match by name */
 384                 if (cmd->name[0] == '\1') /* use tablearg to match */
 385                         return ipfw_lookup_table_extended(chain, cmd->p.kidx, 0,
 386                                 &ifp->if_index, tablearg);
 387                 /* Check name */
 388                 if (cmd->p.glob) {
 389                         if (fnmatch(cmd->name, ifp->if_xname, 0) == 0)
 390                                 return(1);
 391                 } else {
 392                         if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0)
 393                                 return(1);
 394                 }
 395         } else {
 396 #if !defined(USERSPACE) && defined(__FreeBSD__) /* and OSX too ? */
 397                 struct ifaddr *ia;
 398
 399                 if_addr_rlock(ifp);
 400                 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
 401                         if (ia->ifa_addr->sa_family != AF_INET)
 402                                 continue;
 403                         if (cmd->p.ip.s_addr == ((struct sockaddr_in *)
 404                             (ia->ifa_addr))->sin_addr.s_addr) {
 405                                 if_addr_runlock(ifp);
 406                                 return(1);      /* match */
 407                         }
 408                 }
 409                 if_addr_runlock(ifp);
 410 #endif /* __FreeBSD__ */
 411         }
 412         return(0);      /* no match, fail ... */
 413 }
 414
 415 /*
 416  * The verify_path function checks if a route to the src exists and
 417  * if it is reachable via ifp (when provided).
 418  *
 419  * The 'verrevpath' option checks that the interface that an IP packet
 420  * arrives on is the same interface that traffic destined for the
 421  * packet's source address would be routed out of.
 422  * The 'versrcreach' option just checks that the source address is
 423  * reachable via any route (except default) in the routing table.
 424  * These two are a measure to block forged packets. This is also
 425  * commonly known as "anti-spoofing" or Unicast Reverse Path
 426  * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs
 427  * is purposely reminiscent of the Cisco IOS command,
 428  *
 429  *   ip verify unicast reverse-path
 430  *   ip verify unicast source reachable-via any
 431  *
 432  * which implements the same functionality. But note that the syntax
 433  * is misleading, and the check may be performed on all IP packets
 434  * whether unicast, multicast, or broadcast.
 435  */
 436 static int
 437 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib)
 438 {
 439 #if defined(USERSPACE) || !defined(__FreeBSD__)
 440         return 0;
 441 #else
 442         struct nhop4_basic nh4;
 443
 444         if (fib4_lookup_nh_basic(fib, src, NHR_IFAIF, 0, &nh4) != 0)
 445                 return (0);
 446
 447         /*
 448          * If ifp is provided, check for equality with rtentry.
 449          * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
 450          * in order to pass packets injected back by if_simloop():
 451          * routing entry (via lo0) for our own address
 452          * may exist, so we need to handle routing assymetry.
 453          */
 454         if (ifp != NULL && ifp != nh4.nh_ifp)
 455                 return (0);
 456
 457         /* if no ifp provided, check if rtentry is not default route */
 458         if (ifp == NULL && (nh4.nh_flags & NHF_DEFAULT) != 0)
 459                 return (0);
 460
 461         /* or if this is a blackhole/reject route */
 462         if (ifp == NULL && (nh4.nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0)
 463                 return (0);
 464
 465         /* found valid route */
 466         return 1;
 467 #endif /* __FreeBSD__ */
 468 }
 469
 470 #ifdef INET6
 471 /*
 472  * ipv6 specific rules here...
 473  */
 474 static __inline int
 475 icmp6type_match (int type, ipfw_insn_u32 *cmd)
 476 {
 477         return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) );
 478 }
 479
 480 static int
 481 flow6id_match( int curr_flow, ipfw_insn_u32 *cmd )
 482 {
 483         int i;
 484         for (i=0; i <= cmd->o.arg1; ++i )
 485                 if (curr_flow == cmd->d[i] )
 486                         return 1;
 487         return 0;
 488 }
 489
 490 /* support for IP6_*_ME opcodes */
 491 static const struct in6_addr lla_mask = {{{
 492         0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff,
 493         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
 494 }}};
 495
 496 static int
 497 ipfw_localip6(struct in6_addr *in6)
 498 {
 499         struct rm_priotracker in6_ifa_tracker;
 500         struct in6_ifaddr *ia;
 501
 502         if (IN6_IS_ADDR_MULTICAST(in6))
 503                 return (0);
 504
 505         if (!IN6_IS_ADDR_LINKLOCAL(in6))
 506                 return (in6_localip(in6));
 507
 508         IN6_IFADDR_RLOCK(&in6_ifa_tracker);
 509         TAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) {
 510                 if (!IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr))
 511                         continue;
 512                 if (IN6_ARE_MASKED_ADDR_EQUAL(&ia->ia_addr.sin6_addr,
 513                     in6, &lla_mask)) {
 514                         IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
 515                         return (1);
 516                 }
 517         }
 518         IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
 519         return (0);
 520 }
 521
 522 static int
 523 verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib)
 524 {
 525         struct nhop6_basic nh6;
 526
 527         if (IN6_IS_SCOPE_LINKLOCAL(src))
 528                 return (1);
 529
 530         if (fib6_lookup_nh_basic(fib, src, 0, NHR_IFAIF, 0, &nh6) != 0)
 531                 return (0);
 532
 533         /* If ifp is provided, check for equality with route table. */
 534         if (ifp != NULL && ifp != nh6.nh_ifp)
 535                 return (0);
 536
 537         /* if no ifp provided, check if rtentry is not default route */
 538         if (ifp == NULL && (nh6.nh_flags & NHF_DEFAULT) != 0)
 539                 return (0);
 540
 541         /* or if this is a blackhole/reject route */
 542         if (ifp == NULL && (nh6.nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0)
 543                 return (0);
 544
 545         /* found valid route */
 546         return 1;
 547 }
 548
 549 static int
 550 is_icmp6_query(int icmp6_type)
 551 {
 552         if ((icmp6_type <= ICMP6_MAXTYPE) &&
 553             (icmp6_type == ICMP6_ECHO_REQUEST ||
 554             icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
 555             icmp6_type == ICMP6_WRUREQUEST ||
 556             icmp6_type == ICMP6_FQDN_QUERY ||
 557             icmp6_type == ICMP6_NI_QUERY))
 558                 return (1);
 559
 560         return (0);
 561 }
 562
 563 static void
 564 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6)
 565 {
 566         struct mbuf *m;
 567
 568         m = args->m;
 569         if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) {
 570                 struct tcphdr *tcp;
 571                 tcp = (struct tcphdr *)((char *)ip6 + hlen);
 572
 573                 if ((tcp->th_flags & TH_RST) == 0) {
 574                         struct mbuf *m0;
 575                         m0 = ipfw_send_pkt(args->m, &(args->f_id),
 576                             ntohl(tcp->th_seq), ntohl(tcp->th_ack),
 577                             tcp->th_flags | TH_RST);
 578                         if (m0 != NULL)
 579                                 ip6_output(m0, NULL, NULL, 0, NULL, NULL,
 580                                     NULL);
 581                 }
 582                 FREE_PKT(m);
 583         } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */
 584 #if 0
 585                 /*
 586                  * Unlike above, the mbufs need to line up with the ip6 hdr,
 587                  * as the contents are read. We need to m_adj() the
 588                  * needed amount.
 589                  * The mbuf will however be thrown away so we can adjust it.
 590                  * Remember we did an m_pullup on it already so we
 591                  * can make some assumptions about contiguousness.
 592                  */
 593                 if (args->L3offset)
 594                         m_adj(m, args->L3offset);
 595 #endif
 596                 icmp6_error(m, ICMP6_DST_UNREACH, code, 0);
 597         } else
 598                 FREE_PKT(m);
 599
 600         args->m = NULL;
 601 }
 602
 603 #endif /* INET6 */
 604
 605
 606 /*
 607  * sends a reject message, consuming the mbuf passed as an argument.
 608  */
 609 static void
 610 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip)
 611 {
 612
 613 #if 0
 614         /* XXX When ip is not guaranteed to be at mtod() we will
 615          * need to account for this */
 616          * The mbuf will however be thrown away so we can adjust it.
 617          * Remember we did an m_pullup on it already so we
 618          * can make some assumptions about contiguousness.
 619          */
 620         if (args->L3offset)
 621                 m_adj(m, args->L3offset);
 622 #endif
 623         if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */
 624                 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
 625         } else if (args->f_id.proto == IPPROTO_TCP) {
 626                 struct tcphdr *const tcp =
 627                     L3HDR(struct tcphdr, mtod(args->m, struct ip *));
 628                 if ( (tcp->th_flags & TH_RST) == 0) {
 629                         struct mbuf *m;
 630                         m = ipfw_send_pkt(args->m, &(args->f_id),
 631                                 ntohl(tcp->th_seq), ntohl(tcp->th_ack),
 632                                 tcp->th_flags | TH_RST);
 633                         if (m != NULL)
 634                                 ip_output(m, NULL, NULL, 0, NULL, NULL);
 635                 }
 636                 FREE_PKT(args->m);
 637         } else
 638                 FREE_PKT(args->m);
 639         args->m = NULL;
 640 }
 641
 642 /*
 643  * Support for uid/gid/jail lookup. These tests are expensive
 644  * (because we may need to look into the list of active sockets)
 645  * so we cache the results. ugid_lookupp is 0 if we have not
 646  * yet done a lookup, 1 if we succeeded, and -1 if we tried
 647  * and failed. The function always returns the match value.
 648  * We could actually spare the variable and use *uc, setting
 649  * it to '(void *)check_uidgid if we have no info, NULL if
 650  * we tried and failed, or any other value if successful.
 651  */
 652 static int
 653 check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp,
 654     struct ucred **uc)
 655 {
 656 #if defined(USERSPACE)
 657         return 0;       // not supported in userspace
 658 #else
 659 #ifndef __FreeBSD__
 660         /* XXX */
 661         return cred_check(insn, proto, oif,
 662             dst_ip, dst_port, src_ip, src_port,
 663             (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb);
 664 #else  /* FreeBSD */
 665         struct in_addr src_ip, dst_ip;
 666         struct inpcbinfo *pi;
 667         struct ipfw_flow_id *id;
 668         struct inpcb *pcb, *inp;
 669         struct ifnet *oif;
 670         int lookupflags;
 671         int match;
 672
 673         id = &args->f_id;
 674         inp = args->inp;
 675         oif = args->oif;
 676
 677         /*
 678          * Check to see if the UDP or TCP stack supplied us with
 679          * the PCB. If so, rather then holding a lock and looking
 680          * up the PCB, we can use the one that was supplied.
 681          */
 682         if (inp && *ugid_lookupp == 0) {
 683                 INP_LOCK_ASSERT(inp);
 684                 if (inp->inp_socket != NULL) {
 685                         *uc = crhold(inp->inp_cred);
 686                         *ugid_lookupp = 1;
 687                 } else
 688                         *ugid_lookupp = -1;
 689         }
 690         /*
 691          * If we have already been here and the packet has no
 692          * PCB entry associated with it, then we can safely
 693          * assume that this is a no match.
 694          */
 695         if (*ugid_lookupp == -1)
 696                 return (0);
 697         if (id->proto == IPPROTO_TCP) {
 698                 lookupflags = 0;
 699                 pi = &V_tcbinfo;
 700         } else if (id->proto == IPPROTO_UDP) {
 701                 lookupflags = INPLOOKUP_WILDCARD;
 702                 pi = &V_udbinfo;
 703         } else
 704                 return 0;
 705         lookupflags |= INPLOOKUP_RLOCKPCB;
 706         match = 0;
 707         if (*ugid_lookupp == 0) {
 708                 if (id->addr_type == 6) {
 709 #ifdef INET6
 710                         if (oif == NULL)
 711                                 pcb = in6_pcblookup_mbuf(pi,
 712                                     &id->src_ip6, htons(id->src_port),
 713                                     &id->dst_ip6, htons(id->dst_port),
 714                                     lookupflags, oif, args->m);
 715                         else
 716                                 pcb = in6_pcblookup_mbuf(pi,
 717                                     &id->dst_ip6, htons(id->dst_port),
 718                                     &id->src_ip6, htons(id->src_port),
 719                                     lookupflags, oif, args->m);
 720 #else
 721                         *ugid_lookupp = -1;
 722                         return (0);
 723 #endif
 724                 } else {
 725                         src_ip.s_addr = htonl(id->src_ip);
 726                         dst_ip.s_addr = htonl(id->dst_ip);
 727                         if (oif == NULL)
 728                                 pcb = in_pcblookup_mbuf(pi,
 729                                     src_ip, htons(id->src_port),
 730                                     dst_ip, htons(id->dst_port),
 731                                     lookupflags, oif, args->m);
 732                         else
 733                                 pcb = in_pcblookup_mbuf(pi,
 734                                     dst_ip, htons(id->dst_port),
 735                                     src_ip, htons(id->src_port),
 736                                     lookupflags, oif, args->m);
 737                 }
 738                 if (pcb != NULL) {
 739                         INP_RLOCK_ASSERT(pcb);
 740                         *uc = crhold(pcb->inp_cred);
 741                         *ugid_lookupp = 1;
 742                         INP_RUNLOCK(pcb);
 743                 }
 744                 if (*ugid_lookupp == 0) {
 745                         /*
 746                          * We tried and failed, set the variable to -1
 747                          * so we will not try again on this packet.
 748                          */
 749                         *ugid_lookupp = -1;
 750                         return (0);
 751                 }
 752         }
 753         if (insn->o.opcode == O_UID)
 754                 match = ((*uc)->cr_uid == (uid_t)insn->d[0]);
 755         else if (insn->o.opcode == O_GID)
 756                 match = groupmember((gid_t)insn->d[0], *uc);
 757         else if (insn->o.opcode == O_JAIL)
 758                 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]);
 759         return (match);
 760 #endif /* __FreeBSD__ */
 761 #endif /* not supported in userspace */
 762 }
 763
 764 /*
 765  * Helper function to set args with info on the rule after the matching
 766  * one. slot is precise, whereas we guess rule_id as they are
 767  * assigned sequentially.
 768  */
 769 static inline void
 770 set_match(struct ip_fw_args *args, int slot,
 771         struct ip_fw_chain *chain)
 772 {
 773         args->rule.chain_id = chain->id;
 774         args->rule.slot = slot + 1; /* we use 0 as a marker */
 775         args->rule.rule_id = 1 + chain->map[slot]->id;
 776         args->rule.rulenum = chain->map[slot]->rulenum;
 777 }
 778
 779 #ifndef LINEAR_SKIPTO
 780 /*
 781  * Helper function to enable cached rule lookups using
 782  * cached_id and cached_pos fields in ipfw rule.
 783  */
 784 static int
 785 jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num,
 786     int tablearg, int jump_backwards)
 787 {
 788         int f_pos;
 789
 790         /* If possible use cached f_pos (in f->cached_pos),
 791          * whose version is written in f->cached_id
 792          * (horrible hacks to avoid changing the ABI).
 793          */
 794         if (num != IP_FW_TARG && f->cached_id == chain->id)
 795                 f_pos = f->cached_pos;
 796         else {
 797                 int i = IP_FW_ARG_TABLEARG(chain, num, skipto);
 798                 /* make sure we do not jump backward */
 799                 if (jump_backwards == 0 && i <= f->rulenum)
 800                         i = f->rulenum + 1;
 801                 if (chain->idxmap != NULL)
 802                         f_pos = chain->idxmap[i];
 803                 else
 804                         f_pos = ipfw_find_rule(chain, i, 0);
 805                 /* update the cache */
 806                 if (num != IP_FW_TARG) {
 807                         f->cached_id = chain->id;
 808                         f->cached_pos = f_pos;
 809                 }
 810         }
 811
 812         return (f_pos);
 813 }
 814 #else
 815 /*
 816  * Helper function to enable real fast rule lookups.
 817  */
 818 static int
 819 jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num,
 820     int tablearg, int jump_backwards)
 821 {
 822         int f_pos;
 823
 824         num = IP_FW_ARG_TABLEARG(chain, num, skipto);
 825         /* make sure we do not jump backward */
 826         if (jump_backwards == 0 && num <= f->rulenum)
 827                 num = f->rulenum + 1;
 828         f_pos = chain->idxmap[num];
 829
 830         return (f_pos);
 831 }
 832 #endif
 833
 834 #define TARG(k, f)      IP_FW_ARG_TABLEARG(chain, k, f)
 835 /*
 836  * The main check routine for the firewall.
 837  *
 838  * All arguments are in args so we can modify them and return them
 839  * back to the caller.
 840  *
 841  * Parameters:
 842  *
 843  *      args->m (in/out) The packet; we set to NULL when/if we nuke it.
 844  *              Starts with the IP header.
 845  *      args->eh (in)   Mac header if present, NULL for layer3 packet.
 846  *      args->L3offset  Number of bytes bypassed if we came from L2.
 847  *                      e.g. often sizeof(eh)  ** NOTYET **
 848  *      args->oif       Outgoing interface, NULL if packet is incoming.
 849  *              The incoming interface is in the mbuf. (in)
 850  *      args->divert_rule (in/out)
 851  *              Skip up to the first rule past this rule number;
 852  *              upon return, non-zero port number for divert or tee.
 853  *
 854  *      args->rule      Pointer to the last matching rule (in/out)
 855  *      args->next_hop  Socket we are forwarding to (out).
 856  *      args->next_hop6 IPv6 next hop we are forwarding to (out).
 857  *      args->f_id      Addresses grabbed from the packet (out)
 858  *      args->rule.info a cookie depending on rule action
 859  *
 860  * Return value:
 861  *
 862  *      IP_FW_PASS      the packet must be accepted
 863  *      IP_FW_DENY      the packet must be dropped
 864  *      IP_FW_DIVERT    divert packet, port in m_tag
 865  *      IP_FW_TEE       tee packet, port in m_tag
 866  *      IP_FW_DUMMYNET  to dummynet, pipe in args->cookie
 867  *      IP_FW_NETGRAPH  into netgraph, cookie args->cookie
 868  *              args->rule contains the matching rule,
 869  *              args->rule.info has additional information.
 870  *
 871  */
 872 int
 873 ipfw_chk(struct ip_fw_args *args)
 874 {
 875
 876         /*
 877          * Local variables holding state while processing a packet:
 878          *
 879          * IMPORTANT NOTE: to speed up the processing of rules, there
 880          * are some assumption on the values of the variables, which
 881          * are documented here. Should you change them, please check
 882          * the implementation of the various instructions to make sure
 883          * that they still work.
 884          *
 885          * args->eh     The MAC header. It is non-null for a layer2
 886          *      packet, it is NULL for a layer-3 packet.
 887          * **notyet**
 888          * args->L3offset Offset in the packet to the L3 (IP or equiv.) header.
 889          *
 890          * m | args->m  Pointer to the mbuf, as received from the caller.
 891          *      It may change if ipfw_chk() does an m_pullup, or if it
 892          *      consumes the packet because it calls send_reject().
 893          *      XXX This has to change, so that ipfw_chk() never modifies
 894          *      or consumes the buffer.
 895          * ip   is the beginning of the ip(4 or 6) header.
 896          *      Calculated by adding the L3offset to the start of data.
 897          *      (Until we start using L3offset, the packet is
 898          *      supposed to start with the ip header).
 899          */
 900         struct mbuf *m = args->m;
 901         struct ip *ip = mtod(m, struct ip *);
 902
 903         /*
 904          * For rules which contain uid/gid or jail constraints, cache
 905          * a copy of the users credentials after the pcb lookup has been
 906          * executed. This will speed up the processing of rules with
 907          * these types of constraints, as well as decrease contention
 908          * on pcb related locks.
 909          */
 910 #ifndef __FreeBSD__
 911         struct bsd_ucred ucred_cache;
 912 #else
 913         struct ucred *ucred_cache = NULL;
 914 #endif
 915         int ucred_lookup = 0;
 916
 917         /*
 918          * oif | args->oif      If NULL, ipfw_chk has been called on the
 919          *      inbound path (ether_input, ip_input).
 920          *      If non-NULL, ipfw_chk has been called on the outbound path
 921          *      (ether_output, ip_output).
 922          */
 923         struct ifnet *oif = args->oif;
 924
 925         int f_pos = 0;          /* index of current rule in the array */
 926         int retval = 0;
 927
 928         /*
 929          * hlen The length of the IP header.
 930          */
 931         u_int hlen = 0;         /* hlen >0 means we have an IP pkt */
 932
 933         /*
 934          * offset       The offset of a fragment. offset != 0 means that
 935          *      we have a fragment at this offset of an IPv4 packet.
 936          *      offset == 0 means that (if this is an IPv4 packet)
 937          *      this is the first or only fragment.
 938          *      For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header
 939          *      or there is a single packet fragment (fragment header added
 940          *      without needed).  We will treat a single packet fragment as if
 941          *      there was no fragment header (or log/block depending on the
 942          *      V_fw_permit_single_frag6 sysctl setting).
 943          */
 944         u_short offset = 0;
 945         u_short ip6f_mf = 0;
 946
 947         /*
 948          * Local copies of addresses. They are only valid if we have
 949          * an IP packet.
 950          *
 951          * proto        The protocol. Set to 0 for non-ip packets,
 952          *      or to the protocol read from the packet otherwise.
 953          *      proto != 0 means that we have an IPv4 packet.
 954          *
 955          * src_port, dst_port   port numbers, in HOST format. Only
 956          *      valid for TCP and UDP packets.
 957          *
 958          * src_ip, dst_ip       ip addresses, in NETWORK format.
 959          *      Only valid for IPv4 packets.
 960          */
 961         uint8_t proto;
 962         uint16_t src_port = 0, dst_port = 0;    /* NOTE: host format    */
 963         struct in_addr src_ip, dst_ip;          /* NOTE: network format */
 964         uint16_t iplen=0;
 965         int pktlen;
 966         uint16_t        etype = 0;      /* Host order stored ether type */
 967
 968         /*
 969          * dyn_dir = MATCH_UNKNOWN when rules unchecked,
 970          *      MATCH_NONE when checked and not matched (q = NULL),
 971          *      MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL)
 972          */
 973         int dyn_dir = MATCH_UNKNOWN;
 974         ipfw_dyn_rule *q = NULL;
 975         struct ip_fw_chain *chain = &V_layer3_chain;
 976
 977         /*
 978          * We store in ulp a pointer to the upper layer protocol header.
 979          * In the ipv4 case this is easy to determine from the header,
 980          * but for ipv6 we might have some additional headers in the middle.
 981          * ulp is NULL if not found.
 982          */
 983         void *ulp = NULL;               /* upper layer protocol pointer. */
 984
 985         /* XXX ipv6 variables */
 986         int is_ipv6 = 0;
 987         uint8_t icmp6_type = 0;
 988         uint16_t ext_hd = 0;    /* bits vector for extension header filtering */
 989         /* end of ipv6 variables */
 990
 991         int is_ipv4 = 0;
 992
 993         int done = 0;           /* flag to exit the outer loop */
 994         IPFW_RLOCK_TRACKER;
 995
 996         if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready))
 997                 return (IP_FW_PASS);    /* accept */
 998
 999         dst_ip.s_addr = 0;              /* make sure it is initialized */
1000         src_ip.s_addr = 0;              /* make sure it is initialized */
1001         pktlen = m->m_pkthdr.len;
1002         args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */
1003         proto = args->f_id.proto = 0;   /* mark f_id invalid */
1004                 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */
1005
1006 /*
1007  * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous,
1008  * then it sets p to point at the offset "len" in the mbuf. WARNING: the
1009  * pointer might become stale after other pullups (but we never use it
1010  * this way).
1011  */
1012 #define PULLUP_TO(_len, p, T)   PULLUP_LEN(_len, p, sizeof(T))
1013 #define PULLUP_LEN(_len, p, T)                                  \
1014 do {                                                            \
1015         int x = (_len) + T;                                     \
1016         if ((m)->m_len < x) {                                   \
1017                 args->m = m = m_pullup(m, x);                   \
1018                 if (m == NULL)                                  \
1019                         goto pullup_failed;                     \
1020         }                                                       \
1021         p = (mtod(m, char *) + (_len));                         \
1022 } while (0)
1023
1024         /*
1025          * if we have an ether header,
1026          */
1027         if (args->eh)
1028                 etype = ntohs(args->eh->ether_type);
1029
1030         /* Identify IP packets and fill up variables. */
1031         if (pktlen >= sizeof(struct ip6_hdr) &&
1032             (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) {
1033                 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip;
1034                 is_ipv6 = 1;
1035                 args->f_id.addr_type = 6;
1036                 hlen = sizeof(struct ip6_hdr);
1037                 proto = ip6->ip6_nxt;
1038
1039                 /* Search extension headers to find upper layer protocols */
1040                 while (ulp == NULL && offset == 0) {
1041                         switch (proto) {
1042                         case IPPROTO_ICMPV6:
1043                                 PULLUP_TO(hlen, ulp, struct icmp6_hdr);
1044                                 icmp6_type = ICMP6(ulp)->icmp6_type;
1045                                 break;
1046
1047                         case IPPROTO_TCP:
1048                                 PULLUP_TO(hlen, ulp, struct tcphdr);
1049                                 dst_port = TCP(ulp)->th_dport;
1050                                 src_port = TCP(ulp)->th_sport;
1051                                 /* save flags for dynamic rules */
1052                                 args->f_id._flags = TCP(ulp)->th_flags;
1053                                 break;
1054
1055                         case IPPROTO_SCTP:
1056                                 PULLUP_TO(hlen, ulp, struct sctphdr);
1057                                 src_port = SCTP(ulp)->src_port;
1058                                 dst_port = SCTP(ulp)->dest_port;
1059                                 break;
1060
1061                         case IPPROTO_UDP:
1062                                 PULLUP_TO(hlen, ulp, struct udphdr);
1063                                 dst_port = UDP(ulp)->uh_dport;
1064                                 src_port = UDP(ulp)->uh_sport;
1065                                 break;
1066
1067                         case IPPROTO_HOPOPTS:   /* RFC 2460 */
1068                                 PULLUP_TO(hlen, ulp, struct ip6_hbh);
1069                                 ext_hd |= EXT_HOPOPTS;
1070                                 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
1071                                 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
1072                                 ulp = NULL;
1073                                 break;
1074
1075                         case IPPROTO_ROUTING:   /* RFC 2460 */
1076                                 PULLUP_TO(hlen, ulp, struct ip6_rthdr);
1077                                 switch (((struct ip6_rthdr *)ulp)->ip6r_type) {
1078                                 case 0:
1079                                         ext_hd |= EXT_RTHDR0;
1080                                         break;
1081                                 case 2:
1082                                         ext_hd |= EXT_RTHDR2;
1083                                         break;
1084                                 default:
1085                                         if (V_fw_verbose)
1086                                                 printf("IPFW2: IPV6 - Unknown "
1087                                                     "Routing Header type(%d)\n",
1088                                                     ((struct ip6_rthdr *)
1089                                                     ulp)->ip6r_type);
1090                                         if (V_fw_deny_unknown_exthdrs)
1091                                             return (IP_FW_DENY);
1092                                         break;
1093                                 }
1094                                 ext_hd |= EXT_ROUTING;
1095                                 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3;
1096                                 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt;
1097                                 ulp = NULL;
1098                                 break;
1099
1100                         case IPPROTO_FRAGMENT:  /* RFC 2460 */
1101                                 PULLUP_TO(hlen, ulp, struct ip6_frag);
1102                                 ext_hd |= EXT_FRAGMENT;
1103                                 hlen += sizeof (struct ip6_frag);
1104                                 proto = ((struct ip6_frag *)ulp)->ip6f_nxt;
1105                                 offset = ((struct ip6_frag *)ulp)->ip6f_offlg &
1106                                         IP6F_OFF_MASK;
1107                                 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg &
1108                                         IP6F_MORE_FRAG;
1109                                 if (V_fw_permit_single_frag6 == 0 &&
1110                                     offset == 0 && ip6f_mf == 0) {
1111                                         if (V_fw_verbose)
1112                                                 printf("IPFW2: IPV6 - Invalid "
1113                                                     "Fragment Header\n");
1114                                         if (V_fw_deny_unknown_exthdrs)
1115                                             return (IP_FW_DENY);
1116                                         break;
1117                                 }
1118                                 args->f_id.extra =
1119                                     ntohl(((struct ip6_frag *)ulp)->ip6f_ident);
1120                                 ulp = NULL;
1121                                 break;
1122
1123                         case IPPROTO_DSTOPTS:   /* RFC 2460 */
1124                                 PULLUP_TO(hlen, ulp, struct ip6_hbh);
1125                                 ext_hd |= EXT_DSTOPTS;
1126                                 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
1127                                 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
1128                                 ulp = NULL;
1129                                 break;
1130
1131                         case IPPROTO_AH:        /* RFC 2402 */
1132                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
1133                                 ext_hd |= EXT_AH;
1134                                 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2;
1135                                 proto = ((struct ip6_ext *)ulp)->ip6e_nxt;
1136                                 ulp = NULL;
1137                                 break;
1138
1139                         case IPPROTO_ESP:       /* RFC 2406 */
1140                                 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */
1141                                 /* Anything past Seq# is variable length and
1142                                  * data past this ext. header is encrypted. */
1143                                 ext_hd |= EXT_ESP;
1144                                 break;
1145
1146                         case IPPROTO_NONE:      /* RFC 2460 */
1147                                 /*
1148                                  * Packet ends here, and IPv6 header has
1149                                  * already been pulled up. If ip6e_len!=0
1150                                  * then octets must be ignored.
1151                                  */
1152                                 ulp = ip; /* non-NULL to get out of loop. */
1153                                 break;
1154
1155                         case IPPROTO_OSPFIGP:
1156                                 /* XXX OSPF header check? */
1157                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
1158                                 break;
1159
1160                         case IPPROTO_PIM:
1161                                 /* XXX PIM header check? */
1162                                 PULLUP_TO(hlen, ulp, struct pim);
1163                                 break;
1164
1165                         case IPPROTO_CARP:
1166                                 PULLUP_TO(hlen, ulp, struct carp_header);
1167                                 if (((struct carp_header *)ulp)->carp_version !=
1168                                     CARP_VERSION)
1169                                         return (IP_FW_DENY);
1170                                 if (((struct carp_header *)ulp)->carp_type !=
1171                                     CARP_ADVERTISEMENT)
1172                                         return (IP_FW_DENY);
1173                                 break;
1174
1175                         case IPPROTO_IPV6:      /* RFC 2893 */
1176                                 PULLUP_TO(hlen, ulp, struct ip6_hdr);
1177                                 break;
1178
1179                         case IPPROTO_IPV4:      /* RFC 2893 */
1180                                 PULLUP_TO(hlen, ulp, struct ip);
1181                                 break;
1182
1183                         default:
1184                                 if (V_fw_verbose)
1185                                         printf("IPFW2: IPV6 - Unknown "
1186                                             "Extension Header(%d), ext_hd=%x\n",
1187                                              proto, ext_hd);
1188                                 if (V_fw_deny_unknown_exthdrs)
1189                                     return (IP_FW_DENY);
1190                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
1191                                 break;
1192                         } /*switch */
1193                 }
1194                 ip = mtod(m, struct ip *);
1195                 ip6 = (struct ip6_hdr *)ip;
1196                 args->f_id.src_ip6 = ip6->ip6_src;
1197                 args->f_id.dst_ip6 = ip6->ip6_dst;
1198                 args->f_id.src_ip = 0;
1199                 args->f_id.dst_ip = 0;
1200                 args->f_id.flow_id6 = ntohl(ip6->ip6_flow);
1201         } else if (pktlen >= sizeof(struct ip) &&
1202             (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) {
1203                 is_ipv4 = 1;
1204                 hlen = ip->ip_hl << 2;
1205                 args->f_id.addr_type = 4;
1206
1207                 /*
1208                  * Collect parameters into local variables for faster matching.
1209                  */
1210                 proto = ip->ip_p;
1211                 src_ip = ip->ip_src;
1212                 dst_ip = ip->ip_dst;
1213                 offset = ntohs(ip->ip_off) & IP_OFFMASK;
1214                 iplen = ntohs(ip->ip_len);
1215                 pktlen = iplen < pktlen ? iplen : pktlen;
1216
1217                 if (offset == 0) {
1218                         switch (proto) {
1219                         case IPPROTO_TCP:
1220                                 PULLUP_TO(hlen, ulp, struct tcphdr);
1221                                 dst_port = TCP(ulp)->th_dport;
1222                                 src_port = TCP(ulp)->th_sport;
1223                                 /* save flags for dynamic rules */
1224                                 args->f_id._flags = TCP(ulp)->th_flags;
1225                                 break;
1226
1227                         case IPPROTO_SCTP:
1228                                 PULLUP_TO(hlen, ulp, struct sctphdr);
1229                                 src_port = SCTP(ulp)->src_port;
1230                                 dst_port = SCTP(ulp)->dest_port;
1231                                 break;
1232
1233                         case IPPROTO_UDP:
1234                                 PULLUP_TO(hlen, ulp, struct udphdr);
1235                                 dst_port = UDP(ulp)->uh_dport;
1236                                 src_port = UDP(ulp)->uh_sport;
1237                                 break;
1238
1239                         case IPPROTO_ICMP:
1240                                 PULLUP_TO(hlen, ulp, struct icmphdr);
1241                                 //args->f_id.flags = ICMP(ulp)->icmp_type;
1242                                 break;
1243
1244                         default:
1245                                 break;
1246                         }
1247                 }
1248
1249                 ip = mtod(m, struct ip *);
1250                 args->f_id.src_ip = ntohl(src_ip.s_addr);
1251                 args->f_id.dst_ip = ntohl(dst_ip.s_addr);
1252         }
1253 #undef PULLUP_TO
1254         if (proto) { /* we may have port numbers, store them */
1255                 args->f_id.proto = proto;
1256                 args->f_id.src_port = src_port = ntohs(src_port);
1257                 args->f_id.dst_port = dst_port = ntohs(dst_port);
1258         }
1259
1260         IPFW_PF_RLOCK(chain);
1261         if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */
1262                 IPFW_PF_RUNLOCK(chain);
1263                 return (IP_FW_PASS);    /* accept */
1264         }
1265         if (args->rule.slot) {
1266                 /*
1267                  * Packet has already been tagged as a result of a previous
1268                  * match on rule args->rule aka args->rule_id (PIPE, QUEUE,
1269                  * REASS, NETGRAPH, DIVERT/TEE...)
1270                  * Validate the slot and continue from the next one
1271                  * if still present, otherwise do a lookup.
1272                  */
1273                 f_pos = (args->rule.chain_id == chain->id) ?
1274                     args->rule.slot :
1275                     ipfw_find_rule(chain, args->rule.rulenum,
1276                         args->rule.rule_id);
1277         } else {
1278                 f_pos = 0;
1279         }
1280
1281         /*
1282          * Now scan the rules, and parse microinstructions for each rule.
1283          * We have two nested loops and an inner switch. Sometimes we
1284          * need to break out of one or both loops, or re-enter one of
1285          * the loops with updated variables. Loop variables are:
1286          *
1287          *      f_pos (outer loop) points to the current rule.
1288          *              On output it points to the matching rule.
1289          *      done (outer loop) is used as a flag to break the loop.
1290          *      l (inner loop)  residual length of current rule.
1291          *              cmd points to the current microinstruction.
1292          *
1293          * We break the inner loop by setting l=0 and possibly
1294          * cmdlen=0 if we don't want to advance cmd.
1295          * We break the outer loop by setting done=1
1296          * We can restart the inner loop by setting l>0 and f_pos, f, cmd
1297          * as needed.
1298          */
1299         for (; f_pos < chain->n_rules; f_pos++) {
1300                 ipfw_insn *cmd;
1301                 uint32_t tablearg = 0;
1302                 int l, cmdlen, skip_or; /* skip rest of OR block */
1303                 struct ip_fw *f;
1304
1305                 f = chain->map[f_pos];
1306                 if (V_set_disable & (1 << f->set) )
1307                         continue;
1308
1309                 skip_or = 0;
1310                 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ;
1311                     l -= cmdlen, cmd += cmdlen) {
1312                         int match;
1313
1314                         /*
1315                          * check_body is a jump target used when we find a
1316                          * CHECK_STATE, and need to jump to the body of
1317                          * the target rule.
1318                          */
1319
1320 /* check_body: */
1321                         cmdlen = F_LEN(cmd);
1322                         /*
1323                          * An OR block (insn_1 || .. || insn_n) has the
1324                          * F_OR bit set in all but the last instruction.
1325                          * The first match will set "skip_or", and cause
1326                          * the following instructions to be skipped until
1327                          * past the one with the F_OR bit clear.
1328                          */
1329                         if (skip_or) {          /* skip this instruction */
1330                                 if ((cmd->len & F_OR) == 0)
1331                                         skip_or = 0;    /* next one is good */
1332                                 continue;
1333                         }
1334                         match = 0; /* set to 1 if we succeed */
1335
1336                         switch (cmd->opcode) {
1337                         /*
1338                          * The first set of opcodes compares the packet's
1339                          * fields with some pattern, setting 'match' if a
1340                          * match is found. At the end of the loop there is
1341                          * logic to deal with F_NOT and F_OR flags associated
1342                          * with the opcode.
1343                          */
1344                         case O_NOP:
1345                                 match = 1;
1346                                 break;
1347
1348                         case O_FORWARD_MAC:
1349                                 printf("ipfw: opcode %d unimplemented\n",
1350                                     cmd->opcode);
1351                                 break;
1352
1353                         case O_GID:
1354                         case O_UID:
1355                         case O_JAIL:
1356                                 /*
1357                                  * We only check offset == 0 && proto != 0,
1358                                  * as this ensures that we have a
1359                                  * packet with the ports info.
1360                                  */
1361                                 if (offset != 0)
1362                                         break;
1363                                 if (proto == IPPROTO_TCP ||
1364                                     proto == IPPROTO_UDP)
1365                                         match = check_uidgid(
1366                                                     (ipfw_insn_u32 *)cmd,
1367                                                     args, &ucred_lookup,
1368 #ifdef __FreeBSD__
1369                                                     &ucred_cache);
1370 #else
1371                                                     (void *)&ucred_cache);
1372 #endif
1373                                 break;
1374
1375                         case O_RECV:
1376                                 match = iface_match(m->m_pkthdr.rcvif,
1377                                     (ipfw_insn_if *)cmd, chain, &tablearg);
1378                                 break;
1379
1380                         case O_XMIT:
1381                                 match = iface_match(oif, (ipfw_insn_if *)cmd,
1382                                     chain, &tablearg);
1383                                 break;
1384
1385                         case O_VIA:
1386                                 match = iface_match(oif ? oif :
1387                                     m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd,
1388                                     chain, &tablearg);
1389                                 break;
1390
1391                         case O_MACADDR2:
1392                                 if (args->eh != NULL) { /* have MAC header */
1393                                         u_int32_t *want = (u_int32_t *)
1394                                                 ((ipfw_insn_mac *)cmd)->addr;
1395                                         u_int32_t *mask = (u_int32_t *)
1396                                                 ((ipfw_insn_mac *)cmd)->mask;
1397                                         u_int32_t *hdr = (u_int32_t *)args->eh;
1398
1399                                         match =
1400                                             ( want[0] == (hdr[0] & mask[0]) &&
1401                                               want[1] == (hdr[1] & mask[1]) &&
1402                                               want[2] == (hdr[2] & mask[2]) );
1403                                 }
1404                                 break;
1405
1406                         case O_MAC_TYPE:
1407                                 if (args->eh != NULL) {
1408                                         u_int16_t *p =
1409                                             ((ipfw_insn_u16 *)cmd)->ports;
1410                                         int i;
1411
1412                                         for (i = cmdlen - 1; !match && i>0;
1413                                             i--, p += 2)
1414                                                 match = (etype >= p[0] &&
1415                                                     etype <= p[1]);
1416                                 }
1417                                 break;
1418
1419                         case O_FRAG:
1420                                 match = (offset != 0);
1421                                 break;
1422
1423                         case O_IN:      /* "out" is "not in" */
1424                                 match = (oif == NULL);
1425                                 break;
1426
1427                         case O_LAYER2:
1428                                 match = (args->eh != NULL);
1429                                 break;
1430
1431                         case O_DIVERTED:
1432                             {
1433                                 /* For diverted packets, args->rule.info
1434                                  * contains the divert port (in host format)
1435                                  * reason and direction.
1436                                  */
1437                                 uint32_t i = args->rule.info;
1438                                 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT &&
1439                                     cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2);
1440                             }
1441                                 break;
1442
1443                         case O_PROTO:
1444                                 /*
1445                                  * We do not allow an arg of 0 so the
1446                                  * check of "proto" only suffices.
1447                                  */
1448                                 match = (proto == cmd->arg1);
1449                                 break;
1450
1451                         case O_IP_SRC:
1452                                 match = is_ipv4 &&
1453                                     (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1454                                     src_ip.s_addr);
1455                                 break;
1456
1457                         case O_IP_SRC_LOOKUP:
1458                         case O_IP_DST_LOOKUP:
1459                                 if (is_ipv4) {
1460                                     uint32_t key =
1461                                         (cmd->opcode == O_IP_DST_LOOKUP) ?
1462                                             dst_ip.s_addr : src_ip.s_addr;
1463                                     uint32_t v = 0;
1464
1465                                     if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) {
1466                                         /* generic lookup. The key must be
1467                                          * in 32bit big-endian format.
1468                                          */
1469                                         v = ((ipfw_insn_u32 *)cmd)->d[1];
1470                                         if (v == 0)
1471                                             key = dst_ip.s_addr;
1472                                         else if (v == 1)
1473                                             key = src_ip.s_addr;
1474                                         else if (v == 6) /* dscp */
1475                                             key = (ip->ip_tos >> 2) & 0x3f;
1476                                         else if (offset != 0)
1477                                             break;
1478                                         else if (proto != IPPROTO_TCP &&
1479                                                 proto != IPPROTO_UDP)
1480                                             break;
1481                                         else if (v == 2)
1482                                             key = dst_port;
1483                                         else if (v == 3)
1484                                             key = src_port;
1485 #ifndef USERSPACE
1486                                         else if (v == 4 || v == 5) {
1487                                             check_uidgid(
1488                                                 (ipfw_insn_u32 *)cmd,
1489                                                 args, &ucred_lookup,
1490 #ifdef __FreeBSD__
1491                                                 &ucred_cache);
1492                                             if (v == 4 /* O_UID */)
1493                                                 key = ucred_cache->cr_uid;
1494                                             else if (v == 5 /* O_JAIL */)
1495                                                 key = ucred_cache->cr_prison->pr_id;
1496 #else /* !__FreeBSD__ */
1497                                                 (void *)&ucred_cache);
1498                                             if (v ==4 /* O_UID */)
1499                                                 key = ucred_cache.uid;
1500                                             else if (v == 5 /* O_JAIL */)
1501                                                 key = ucred_cache.xid;
1502 #endif /* !__FreeBSD__ */
1503                                         }
1504 #endif /* !USERSPACE */
1505                                         else
1506                                             break;
1507                                     }
1508                                     match = ipfw_lookup_table(chain,
1509                                         cmd->arg1, key, &v);
1510                                     if (!match)
1511                                         break;
1512                                     if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
1513                                         match =
1514                                             ((ipfw_insn_u32 *)cmd)->d[0] == v;
1515                                     else
1516                                         tablearg = v;
1517                                 } else if (is_ipv6) {
1518                                         uint32_t v = 0;
1519                                         void *pkey = (cmd->opcode == O_IP_DST_LOOKUP) ?
1520                                                 &args->f_id.dst_ip6: &args->f_id.src_ip6;
1521                                         match = ipfw_lookup_table_extended(chain,
1522                                                         cmd->arg1,
1523                                                         sizeof(struct in6_addr),
1524                                                         pkey, &v);
1525                                         if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
1526                                                 match = ((ipfw_insn_u32 *)cmd)->d[0] == v;
1527                                         if (match)
1528                                                 tablearg = v;
1529                                 }
1530                                 break;
1531
1532                         case O_IP_FLOW_LOOKUP:
1533                                 {
1534                                         uint32_t v = 0;
1535                                         match = ipfw_lookup_table_extended(chain,
1536                                             cmd->arg1, 0, &args->f_id, &v);
1537                                         if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
1538                                                 match = ((ipfw_insn_u32 *)cmd)->d[0] == v;
1539                                         if (match)
1540                                                 tablearg = v;
1541                                 }
1542                                 break;
1543                         case O_IP_SRC_MASK:
1544                         case O_IP_DST_MASK:
1545                                 if (is_ipv4) {
1546                                     uint32_t a =
1547                                         (cmd->opcode == O_IP_DST_MASK) ?
1548                                             dst_ip.s_addr : src_ip.s_addr;
1549                                     uint32_t *p = ((ipfw_insn_u32 *)cmd)->d;
1550                                     int i = cmdlen-1;
1551
1552                                     for (; !match && i>0; i-= 2, p+= 2)
1553                                         match = (p[0] == (a & p[1]));
1554                                 }
1555                                 break;
1556
1557                         case O_IP_SRC_ME:
1558                                 if (is_ipv4) {
1559                                         struct ifnet *tif;
1560
1561                                         INADDR_TO_IFP(src_ip, tif);
1562                                         match = (tif != NULL);
1563                                         break;
1564                                 }
1565 #ifdef INET6
1566                                 /* FALLTHROUGH */
1567                         case O_IP6_SRC_ME:
1568                                 match= is_ipv6 && ipfw_localip6(&args->f_id.src_ip6);
1569 #endif
1570                                 break;
1571
1572                         case O_IP_DST_SET:
1573                         case O_IP_SRC_SET:
1574                                 if (is_ipv4) {
1575                                         u_int32_t *d = (u_int32_t *)(cmd+1);
1576                                         u_int32_t addr =
1577                                             cmd->opcode == O_IP_DST_SET ?
1578                                                 args->f_id.dst_ip :
1579                                                 args->f_id.src_ip;
1580
1581                                             if (addr < d[0])
1582                                                     break;
1583                                             addr -= d[0]; /* subtract base */
1584                                             match = (addr < cmd->arg1) &&
1585                                                 ( d[ 1 + (addr>>5)] &
1586                                                   (1<<(addr & 0x1f)) );
1587                                 }
1588                                 break;
1589
1590                         case O_IP_DST:
1591                                 match = is_ipv4 &&
1592                                     (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1593                                     dst_ip.s_addr);
1594                                 break;
1595
1596                         case O_IP_DST_ME:
1597                                 if (is_ipv4) {
1598                                         struct ifnet *tif;
1599
1600                                         INADDR_TO_IFP(dst_ip, tif);
1601                                         match = (tif != NULL);
1602                                         break;
1603                                 }
1604 #ifdef INET6
1605                                 /* FALLTHROUGH */
1606                         case O_IP6_DST_ME:
1607                                 match= is_ipv6 && ipfw_localip6(&args->f_id.dst_ip6);
1608 #endif
1609                                 break;
1610
1611
1612                         case O_IP_SRCPORT:
1613                         case O_IP_DSTPORT:
1614                                 /*
1615                                  * offset == 0 && proto != 0 is enough
1616                                  * to guarantee that we have a
1617                                  * packet with port info.
1618                                  */
1619                                 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP)
1620                                     && offset == 0) {
1621                                         u_int16_t x =
1622                                             (cmd->opcode == O_IP_SRCPORT) ?
1623                                                 src_port : dst_port ;
1624                                         u_int16_t *p =
1625                                             ((ipfw_insn_u16 *)cmd)->ports;
1626                                         int i;
1627
1628                                         for (i = cmdlen - 1; !match && i>0;
1629                                             i--, p += 2)
1630                                                 match = (x>=p[0] && x<=p[1]);
1631                                 }
1632                                 break;
1633
1634                         case O_ICMPTYPE:
1635                                 match = (offset == 0 && proto==IPPROTO_ICMP &&
1636                                     icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) );
1637                                 break;
1638
1639 #ifdef INET6
1640                         case O_ICMP6TYPE:
1641                                 match = is_ipv6 && offset == 0 &&
1642                                     proto==IPPROTO_ICMPV6 &&
1643                                     icmp6type_match(
1644                                         ICMP6(ulp)->icmp6_type,
1645                                         (ipfw_insn_u32 *)cmd);
1646                                 break;
1647 #endif /* INET6 */
1648
1649                         case O_IPOPT:
1650                                 match = (is_ipv4 &&
1651                                     ipopts_match(ip, cmd) );
1652                                 break;
1653
1654                         case O_IPVER:
1655                                 match = (is_ipv4 &&
1656                                     cmd->arg1 == ip->ip_v);
1657                                 break;
1658
1659                         case O_IPID:
1660                         case O_IPLEN:
1661                         case O_IPTTL:
1662                                 if (is_ipv4) {  /* only for IP packets */
1663                                     uint16_t x;
1664                                     uint16_t *p;
1665                                     int i;
1666
1667                                     if (cmd->opcode == O_IPLEN)
1668                                         x = iplen;
1669                                     else if (cmd->opcode == O_IPTTL)
1670                                         x = ip->ip_ttl;
1671                                     else /* must be IPID */
1672                                         x = ntohs(ip->ip_id);
1673                                     if (cmdlen == 1) {
1674                                         match = (cmd->arg1 == x);
1675                                         break;
1676                                     }
1677                                     /* otherwise we have ranges */
1678                                     p = ((ipfw_insn_u16 *)cmd)->ports;
1679                                     i = cmdlen - 1;
1680                                     for (; !match && i>0; i--, p += 2)
1681                                         match = (x >= p[0] && x <= p[1]);
1682                                 }
1683                                 break;
1684
1685                         case O_IPPRECEDENCE:
1686                                 match = (is_ipv4 &&
1687                                     (cmd->arg1 == (ip->ip_tos & 0xe0)) );
1688                                 break;
1689
1690                         case O_IPTOS:
1691                                 match = (is_ipv4 &&
1692                                     flags_match(cmd, ip->ip_tos));
1693                                 break;
1694
1695                         case O_DSCP:
1696                             {
1697                                 uint32_t *p;
1698                                 uint16_t x;
1699
1700                                 p = ((ipfw_insn_u32 *)cmd)->d;
1701
1702                                 if (is_ipv4)
1703                                         x = ip->ip_tos >> 2;
1704                                 else if (is_ipv6) {
1705                                         uint8_t *v;
1706                                         v = &((struct ip6_hdr *)ip)->ip6_vfc;
1707                                         x = (*v & 0x0F) << 2;
1708                                         v++;
1709                                         x |= *v >> 6;
1710                                 } else
1711                                         break;
1712
1713                                 /* DSCP bitmask is stored as low_u32 high_u32 */
1714                                 if (x >= 32)
1715                                         match = *(p + 1) & (1 << (x - 32));
1716                                 else
1717                                         match = *p & (1 << x);
1718                             }
1719                                 break;
1720
1721                         case O_TCPDATALEN:
1722                                 if (proto == IPPROTO_TCP && offset == 0) {
1723                                     struct tcphdr *tcp;
1724                                     uint16_t x;
1725                                     uint16_t *p;
1726                                     int i;
1727
1728                                     tcp = TCP(ulp);
1729                                     x = iplen -
1730                                         ((ip->ip_hl + tcp->th_off) << 2);
1731                                     if (cmdlen == 1) {
1732                                         match = (cmd->arg1 == x);
1733                                         break;
1734                                     }
1735                                     /* otherwise we have ranges */
1736                                     p = ((ipfw_insn_u16 *)cmd)->ports;
1737                                     i = cmdlen - 1;
1738                                     for (; !match && i>0; i--, p += 2)
1739                                         match = (x >= p[0] && x <= p[1]);
1740                                 }
1741                                 break;
1742
1743                         case O_TCPFLAGS:
1744                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1745                                     flags_match(cmd, TCP(ulp)->th_flags));
1746                                 break;
1747
1748                         case O_TCPOPTS:
1749                                 if (proto == IPPROTO_TCP && offset == 0 && ulp){
1750                                         PULLUP_LEN(hlen, ulp,
1751                                             (TCP(ulp)->th_off << 2));
1752                                         match = tcpopts_match(TCP(ulp), cmd);
1753                                 }
1754                                 break;
1755
1756                         case O_TCPSEQ:
1757                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1758                                     ((ipfw_insn_u32 *)cmd)->d[0] ==
1759                                         TCP(ulp)->th_seq);
1760                                 break;
1761
1762                         case O_TCPACK:
1763                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1764                                     ((ipfw_insn_u32 *)cmd)->d[0] ==
1765                                         TCP(ulp)->th_ack);
1766                                 break;
1767
1768                         case O_TCPWIN:
1769                                 if (proto == IPPROTO_TCP && offset == 0) {
1770                                     uint16_t x;
1771                                     uint16_t *p;
1772                                     int i;
1773
1774                                     x = ntohs(TCP(ulp)->th_win);
1775                                     if (cmdlen == 1) {
1776                                         match = (cmd->arg1 == x);
1777                                         break;
1778                                     }
1779                                     /* Otherwise we have ranges. */
1780                                     p = ((ipfw_insn_u16 *)cmd)->ports;
1781                                     i = cmdlen - 1;
1782                                     for (; !match && i > 0; i--, p += 2)
1783                                         match = (x >= p[0] && x <= p[1]);
1784                                 }
1785                                 break;
1786
1787                         case O_ESTAB:
1788                                 /* reject packets which have SYN only */
1789                                 /* XXX should i also check for TH_ACK ? */
1790                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1791                                     (TCP(ulp)->th_flags &
1792                                      (TH_RST | TH_ACK | TH_SYN)) != TH_SYN);
1793                                 break;
1794
1795                         case O_ALTQ: {
1796                                 struct pf_mtag *at;
1797                                 struct m_tag *mtag;
1798                                 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd;
1799
1800                                 /*
1801                                  * ALTQ uses mbuf tags from another
1802                                  * packet filtering system - pf(4).
1803                                  * We allocate a tag in its format
1804                                  * and fill it in, pretending to be pf(4).
1805                                  */
1806                                 match = 1;
1807                                 at = pf_find_mtag(m);
1808                                 if (at != NULL && at->qid != 0)
1809                                         break;
1810                                 mtag = m_tag_get(PACKET_TAG_PF,
1811                                     sizeof(struct pf_mtag), M_NOWAIT | M_ZERO);
1812                                 if (mtag == NULL) {
1813                                         /*
1814                                          * Let the packet fall back to the
1815                                          * default ALTQ.
1816                                          */
1817                                         break;
1818                                 }
1819                                 m_tag_prepend(m, mtag);
1820                                 at = (struct pf_mtag *)(mtag + 1);
1821                                 at->qid = altq->qid;
1822                                 at->hdr = ip;
1823                                 break;
1824                         }
1825
1826                         case O_LOG:
1827                                 ipfw_log(chain, f, hlen, args, m,
1828                                     oif, offset | ip6f_mf, tablearg, ip);
1829                                 match = 1;
1830                                 break;
1831
1832                         case O_PROB:
1833                                 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]);
1834                                 break;
1835
1836                         case O_VERREVPATH:
1837                                 /* Outgoing packets automatically pass/match */
1838                                 match = ((oif != NULL) ||
1839                                     (m->m_pkthdr.rcvif == NULL) ||
1840                                     (
1841 #ifdef INET6
1842                                     is_ipv6 ?
1843                                         verify_path6(&(args->f_id.src_ip6),
1844                                             m->m_pkthdr.rcvif, args->f_id.fib) :
1845 #endif
1846                                     verify_path(src_ip, m->m_pkthdr.rcvif,
1847                                         args->f_id.fib)));
1848                                 break;
1849
1850                         case O_VERSRCREACH:
1851                                 /* Outgoing packets automatically pass/match */
1852                                 match = (hlen > 0 && ((oif != NULL) ||
1853 #ifdef INET6
1854                                     is_ipv6 ?
1855                                         verify_path6(&(args->f_id.src_ip6),
1856                                             NULL, args->f_id.fib) :
1857 #endif
1858                                     verify_path(src_ip, NULL, args->f_id.fib)));
1859                                 break;
1860
1861                         case O_ANTISPOOF:
1862                                 /* Outgoing packets automatically pass/match */
1863                                 if (oif == NULL && hlen > 0 &&
1864                                     (  (is_ipv4 && in_localaddr(src_ip))
1865 #ifdef INET6
1866                                     || (is_ipv6 &&
1867                                         in6_localaddr(&(args->f_id.src_ip6)))
1868 #endif
1869                                     ))
1870                                         match =
1871 #ifdef INET6
1872                                             is_ipv6 ? verify_path6(
1873                                                 &(args->f_id.src_ip6),
1874                                                 m->m_pkthdr.rcvif,
1875                                                 args->f_id.fib) :
1876 #endif
1877                                             verify_path(src_ip,
1878                                                 m->m_pkthdr.rcvif,
1879                                                 args->f_id.fib);
1880                                 else
1881                                         match = 1;
1882                                 break;
1883
1884                         case O_IPSEC:
1885 #ifdef IPSEC
1886                                 match = (m_tag_find(m,
1887                                     PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL);
1888 #endif
1889                                 /* otherwise no match */
1890                                 break;
1891
1892 #ifdef INET6
1893                         case O_IP6_SRC:
1894                                 match = is_ipv6 &&
1895                                     IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6,
1896                                     &((ipfw_insn_ip6 *)cmd)->addr6);
1897                                 break;
1898
1899                         case O_IP6_DST:
1900                                 match = is_ipv6 &&
1901                                 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6,
1902                                     &((ipfw_insn_ip6 *)cmd)->addr6);
1903                                 break;
1904                         case O_IP6_SRC_MASK:
1905                         case O_IP6_DST_MASK:
1906                                 if (is_ipv6) {
1907                                         int i = cmdlen - 1;
1908                                         struct in6_addr p;
1909                                         struct in6_addr *d =
1910                                             &((ipfw_insn_ip6 *)cmd)->addr6;
1911
1912                                         for (; !match && i > 0; d += 2,
1913                                             i -= F_INSN_SIZE(struct in6_addr)
1914                                             * 2) {
1915                                                 p = (cmd->opcode ==
1916                                                     O_IP6_SRC_MASK) ?
1917                                                     args->f_id.src_ip6:
1918                                                     args->f_id.dst_ip6;
1919                                                 APPLY_MASK(&p, &d[1]);
1920                                                 match =
1921                                                     IN6_ARE_ADDR_EQUAL(&d[0],
1922                                                     &p);
1923                                         }
1924                                 }
1925                                 break;
1926
1927                         case O_FLOW6ID:
1928                                 match = is_ipv6 &&
1929                                     flow6id_match(args->f_id.flow_id6,
1930                                     (ipfw_insn_u32 *) cmd);
1931                                 break;
1932
1933                         case O_EXT_HDR:
1934                                 match = is_ipv6 &&
1935                                     (ext_hd & ((ipfw_insn *) cmd)->arg1);
1936                                 break;
1937
1938                         case O_IP6:
1939                                 match = is_ipv6;
1940                                 break;
1941 #endif
1942
1943                         case O_IP4:
1944                                 match = is_ipv4;
1945                                 break;
1946
1947                         case O_TAG: {
1948                                 struct m_tag *mtag;
1949                                 uint32_t tag = TARG(cmd->arg1, tag);
1950
1951                                 /* Packet is already tagged with this tag? */
1952                                 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL);
1953
1954                                 /* We have `untag' action when F_NOT flag is
1955                                  * present. And we must remove this mtag from
1956                                  * mbuf and reset `match' to zero (`match' will
1957                                  * be inversed later).
1958                                  * Otherwise we should allocate new mtag and
1959                                  * push it into mbuf.
1960                                  */
1961                                 if (cmd->len & F_NOT) { /* `untag' action */
1962                                         if (mtag != NULL)
1963                                                 m_tag_delete(m, mtag);
1964                                         match = 0;
1965                                 } else {
1966                                         if (mtag == NULL) {
1967                                                 mtag = m_tag_alloc( MTAG_IPFW,
1968                                                     tag, 0, M_NOWAIT);
1969                                                 if (mtag != NULL)
1970                                                         m_tag_prepend(m, mtag);
1971                                         }
1972                                         match = 1;
1973                                 }
1974                                 break;
1975                         }
1976
1977                         case O_FIB: /* try match the specified fib */
1978                                 if (args->f_id.fib == cmd->arg1)
1979                                         match = 1;
1980                                 break;
1981
1982                         case O_SOCKARG: {
1983 #ifndef USERSPACE       /* not supported in userspace */
1984                                 struct inpcb *inp = args->inp;
1985                                 struct inpcbinfo *pi;
1986
1987                                 if (is_ipv6) /* XXX can we remove this ? */
1988                                         break;
1989
1990                                 if (proto == IPPROTO_TCP)
1991                                         pi = &V_tcbinfo;
1992                                 else if (proto == IPPROTO_UDP)
1993                                         pi = &V_udbinfo;
1994                                 else
1995                                         break;
1996
1997                                 /*
1998                                  * XXXRW: so_user_cookie should almost
1999                                  * certainly be inp_user_cookie?
2000                                  */
2001
2002                                 /* For incoming packet, lookup up the
2003                                 inpcb using the src/dest ip/port tuple */
2004                                 if (inp == NULL) {
2005                                         inp = in_pcblookup(pi,
2006                                                 src_ip, htons(src_port),
2007                                                 dst_ip, htons(dst_port),
2008                                                 INPLOOKUP_RLOCKPCB, NULL);
2009                                         if (inp != NULL) {
2010                                                 tablearg =
2011                                                     inp->inp_socket->so_user_cookie;
2012                                                 if (tablearg)
2013                                                         match = 1;
2014                                                 INP_RUNLOCK(inp);
2015                                         }
2016                                 } else {
2017                                         if (inp->inp_socket) {
2018                                                 tablearg =
2019                                                     inp->inp_socket->so_user_cookie;
2020                                                 if (tablearg)
2021                                                         match = 1;
2022                                         }
2023                                 }
2024 #endif /* !USERSPACE */
2025                                 break;
2026                         }
2027
2028                         case O_TAGGED: {
2029                                 struct m_tag *mtag;
2030                                 uint32_t tag = TARG(cmd->arg1, tag);
2031
2032                                 if (cmdlen == 1) {
2033                                         match = m_tag_locate(m, MTAG_IPFW,
2034                                             tag, NULL) != NULL;
2035                                         break;
2036                                 }
2037
2038                                 /* we have ranges */
2039                                 for (mtag = m_tag_first(m);
2040                                     mtag != NULL && !match;
2041                                     mtag = m_tag_next(m, mtag)) {
2042                                         uint16_t *p;
2043                                         int i;
2044
2045                                         if (mtag->m_tag_cookie != MTAG_IPFW)
2046                                                 continue;
2047
2048                                         p = ((ipfw_insn_u16 *)cmd)->ports;
2049                                         i = cmdlen - 1;
2050                                         for(; !match && i > 0; i--, p += 2)
2051                                                 match =
2052                                                     mtag->m_tag_id >= p[0] &&
2053                                                     mtag->m_tag_id <= p[1];
2054                                 }
2055                                 break;
2056                         }
2057
2058                         /*
2059                          * The second set of opcodes represents 'actions',
2060                          * i.e. the terminal part of a rule once the packet
2061                          * matches all previous patterns.
2062                          * Typically there is only one action for each rule,
2063                          * and the opcode is stored at the end of the rule
2064                          * (but there are exceptions -- see below).
2065                          *
2066                          * In general, here we set retval and terminate the
2067                          * outer loop (would be a 'break 3' in some language,
2068                          * but we need to set l=0, done=1)
2069                          *
2070                          * Exceptions:
2071                          * O_COUNT and O_SKIPTO actions:
2072                          *   instead of terminating, we jump to the next rule
2073                          *   (setting l=0), or to the SKIPTO target (setting
2074                          *   f/f_len, cmd and l as needed), respectively.
2075                          *
2076                          * O_TAG, O_LOG and O_ALTQ action parameters:
2077                          *   perform some action and set match = 1;
2078                          *
2079                          * O_LIMIT and O_KEEP_STATE: these opcodes are
2080                          *   not real 'actions', and are stored right
2081                          *   before the 'action' part of the rule.
2082                          *   These opcodes try to install an entry in the
2083                          *   state tables; if successful, we continue with
2084                          *   the next opcode (match=1; break;), otherwise
2085                          *   the packet must be dropped (set retval,
2086                          *   break loops with l=0, done=1)
2087                          *
2088                          * O_PROBE_STATE and O_CHECK_STATE: these opcodes
2089                          *   cause a lookup of the state table, and a jump
2090                          *   to the 'action' part of the parent rule
2091                          *   if an entry is found, or
2092                          *   (CHECK_STATE only) a jump to the next rule if
2093                          *   the entry is not found.
2094                          *   The result of the lookup is cached so that
2095                          *   further instances of these opcodes become NOPs.
2096                          *   The jump to the next rule is done by setting
2097                          *   l=0, cmdlen=0.
2098                          */
2099                         case O_LIMIT:
2100                         case O_KEEP_STATE:
2101                                 if (ipfw_install_state(chain, f,
2102                                     (ipfw_insn_limit *)cmd, args, tablearg)) {
2103                                         /* error or limit violation */
2104                                         retval = IP_FW_DENY;
2105                                         l = 0;  /* exit inner loop */
2106                                         done = 1; /* exit outer loop */
2107                                 }
2108                                 match = 1;
2109                                 break;
2110
2111                         case O_PROBE_STATE:
2112                         case O_CHECK_STATE:
2113                                 /*
2114                                  * dynamic rules are checked at the first
2115                                  * keep-state or check-state occurrence,
2116                                  * with the result being stored in dyn_dir.
2117                                  * The compiler introduces a PROBE_STATE
2118                                  * instruction for us when we have a
2119                                  * KEEP_STATE (because PROBE_STATE needs
2120                                  * to be run first).
2121                                  */
2122                                 if (dyn_dir == MATCH_UNKNOWN &&
2123                                     (q = ipfw_lookup_dyn_rule(&args->f_id,
2124                                      &dyn_dir, proto == IPPROTO_TCP ?
2125                                         TCP(ulp) : NULL))
2126                                         != NULL) {
2127                                         /*
2128                                          * Found dynamic entry, update stats
2129                                          * and jump to the 'action' part of
2130                                          * the parent rule by setting
2131                                          * f, cmd, l and clearing cmdlen.
2132                                          */
2133                                         IPFW_INC_DYN_COUNTER(q, pktlen);
2134                                         /* XXX we would like to have f_pos
2135                                          * readily accessible in the dynamic
2136                                          * rule, instead of having to
2137                                          * lookup q->rule.
2138                                          */
2139                                         f = q->rule;
2140                                         f_pos = ipfw_find_rule(chain,
2141                                                 f->rulenum, f->id);
2142                                         cmd = ACTION_PTR(f);
2143                                         l = f->cmd_len - f->act_ofs;
2144                                         ipfw_dyn_unlock(q);
2145                                         cmdlen = 0;
2146                                         match = 1;
2147                                         break;
2148                                 }
2149                                 /*
2150                                  * Dynamic entry not found. If CHECK_STATE,
2151                                  * skip to next rule, if PROBE_STATE just
2152                                  * ignore and continue with next opcode.
2153                                  */
2154                                 if (cmd->opcode == O_CHECK_STATE)
2155                                         l = 0;  /* exit inner loop */
2156                                 match = 1;
2157                                 break;
2158
2159                         case O_ACCEPT:
2160                                 retval = 0;     /* accept */
2161                                 l = 0;          /* exit inner loop */
2162                                 done = 1;       /* exit outer loop */
2163                                 break;
2164
2165                         case O_PIPE:
2166                         case O_QUEUE:
2167                                 set_match(args, f_pos, chain);
2168                                 args->rule.info = TARG(cmd->arg1, pipe);
2169                                 if (cmd->opcode == O_PIPE)
2170                                         args->rule.info |= IPFW_IS_PIPE;
2171                                 if (V_fw_one_pass)
2172                                         args->rule.info |= IPFW_ONEPASS;
2173                                 retval = IP_FW_DUMMYNET;
2174                                 l = 0;          /* exit inner loop */
2175                                 done = 1;       /* exit outer loop */
2176                                 break;
2177
2178                         case O_DIVERT:
2179                         case O_TEE:
2180                                 if (args->eh) /* not on layer 2 */
2181                                     break;
2182                                 /* otherwise this is terminal */
2183                                 l = 0;          /* exit inner loop */
2184                                 done = 1;       /* exit outer loop */
2185                                 retval = (cmd->opcode == O_DIVERT) ?
2186                                         IP_FW_DIVERT : IP_FW_TEE;
2187                                 set_match(args, f_pos, chain);
2188                                 args->rule.info = TARG(cmd->arg1, divert);
2189                                 break;
2190
2191                         case O_COUNT:
2192                                 IPFW_INC_RULE_COUNTER(f, pktlen);
2193                                 l = 0;          /* exit inner loop */
2194                                 break;
2195
2196                         case O_SKIPTO:
2197                             IPFW_INC_RULE_COUNTER(f, pktlen);
2198                             f_pos = JUMP(chain, f, cmd->arg1, tablearg, 0);
2199                             /*
2200                              * Skip disabled rules, and re-enter
2201                              * the inner loop with the correct
2202                              * f_pos, f, l and cmd.
2203                              * Also clear cmdlen and skip_or
2204                              */
2205                             for (; f_pos < chain->n_rules - 1 &&
2206                                     (V_set_disable &
2207                                      (1 << chain->map[f_pos]->set));
2208                                     f_pos++)
2209                                 ;
2210                             /* Re-enter the inner loop at the skipto rule. */
2211                             f = chain->map[f_pos];
2212                             l = f->cmd_len;
2213                             cmd = f->cmd;
2214                             match = 1;
2215                             cmdlen = 0;
2216                             skip_or = 0;
2217                             continue;
2218                             break;      /* not reached */
2219
2220                         case O_CALLRETURN: {
2221                                 /*
2222                                  * Implementation of `subroutine' call/return,
2223                                  * in the stack carried in an mbuf tag. This
2224                                  * is different from `skipto' in that any call
2225                                  * address is possible (`skipto' must prevent
2226                                  * backward jumps to avoid endless loops).
2227                                  * We have `return' action when F_NOT flag is
2228                                  * present. The `m_tag_id' field is used as
2229                                  * stack pointer.
2230                                  */
2231                                 struct m_tag *mtag;
2232                                 uint16_t jmpto, *stack;
2233
2234 #define IS_CALL         ((cmd->len & F_NOT) == 0)
2235 #define IS_RETURN       ((cmd->len & F_NOT) != 0)
2236                                 /*
2237                                  * Hand-rolled version of m_tag_locate() with
2238                                  * wildcard `type'.
2239                                  * If not already tagged, allocate new tag.
2240                                  */
2241                                 mtag = m_tag_first(m);
2242                                 while (mtag != NULL) {
2243                                         if (mtag->m_tag_cookie ==
2244                                             MTAG_IPFW_CALL)
2245                                                 break;
2246                                         mtag = m_tag_next(m, mtag);
2247                                 }
2248                                 if (mtag == NULL && IS_CALL) {
2249                                         mtag = m_tag_alloc(MTAG_IPFW_CALL, 0,
2250                                             IPFW_CALLSTACK_SIZE *
2251                                             sizeof(uint16_t), M_NOWAIT);
2252                                         if (mtag != NULL)
2253                                                 m_tag_prepend(m, mtag);
2254                                 }
2255
2256                                 /*
2257                                  * On error both `call' and `return' just
2258                                  * continue with next rule.
2259                                  */
2260                                 if (IS_RETURN && (mtag == NULL ||
2261                                     mtag->m_tag_id == 0)) {
2262                                         l = 0;          /* exit inner loop */
2263                                         break;
2264                                 }
2265                                 if (IS_CALL && (mtag == NULL ||
2266                                     mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) {
2267                                         printf("ipfw: call stack error, "
2268                                             "go to next rule\n");
2269                                         l = 0;          /* exit inner loop */
2270                                         break;
2271                                 }
2272
2273                                 IPFW_INC_RULE_COUNTER(f, pktlen);
2274                                 stack = (uint16_t *)(mtag + 1);
2275
2276                                 /*
2277                                  * The `call' action may use cached f_pos
2278                                  * (in f->next_rule), whose version is written
2279                                  * in f->next_rule.
2280                                  * The `return' action, however, doesn't have
2281                                  * fixed jump address in cmd->arg1 and can't use
2282                                  * cache.
2283                                  */
2284                                 if (IS_CALL) {
2285                                         stack[mtag->m_tag_id] = f->rulenum;
2286                                         mtag->m_tag_id++;
2287                                         f_pos = JUMP(chain, f, cmd->arg1,
2288                                             tablearg, 1);
2289                                 } else {        /* `return' action */
2290                                         mtag->m_tag_id--;
2291                                         jmpto = stack[mtag->m_tag_id] + 1;
2292                                         f_pos = ipfw_find_rule(chain, jmpto, 0);
2293                                 }
2294
2295                                 /*
2296                                  * Skip disabled rules, and re-enter
2297                                  * the inner loop with the correct
2298                                  * f_pos, f, l and cmd.
2299                                  * Also clear cmdlen and skip_or
2300                                  */
2301                                 for (; f_pos < chain->n_rules - 1 &&
2302                                     (V_set_disable &
2303                                     (1 << chain->map[f_pos]->set)); f_pos++)
2304                                         ;
2305                                 /* Re-enter the inner loop at the dest rule. */
2306                                 f = chain->map[f_pos];
2307                                 l = f->cmd_len;
2308                                 cmd = f->cmd;
2309                                 cmdlen = 0;
2310                                 skip_or = 0;
2311                                 continue;
2312                                 break;  /* NOTREACHED */
2313                         }
2314 #undef IS_CALL
2315 #undef IS_RETURN
2316
2317                         case O_REJECT:
2318                                 /*
2319                                  * Drop the packet and send a reject notice
2320                                  * if the packet is not ICMP (or is an ICMP
2321                                  * query), and it is not multicast/broadcast.
2322                                  */
2323                                 if (hlen > 0 && is_ipv4 && offset == 0 &&
2324                                     (proto != IPPROTO_ICMP ||
2325                                      is_icmp_query(ICMP(ulp))) &&
2326                                     !(m->m_flags & (M_BCAST|M_MCAST)) &&
2327                                     !IN_MULTICAST(ntohl(dst_ip.s_addr))) {
2328                                         send_reject(args, cmd->arg1, iplen, ip);
2329                                         m = args->m;
2330                                 }
2331                                 /* FALLTHROUGH */
2332 #ifdef INET6
2333                         case O_UNREACH6:
2334                                 if (hlen > 0 && is_ipv6 &&
2335                                     ((offset & IP6F_OFF_MASK) == 0) &&
2336                                     (proto != IPPROTO_ICMPV6 ||
2337                                      (is_icmp6_query(icmp6_type) == 1)) &&
2338                                     !(m->m_flags & (M_BCAST|M_MCAST)) &&
2339                                     !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) {
2340                                         send_reject6(
2341                                             args, cmd->arg1, hlen,
2342                                             (struct ip6_hdr *)ip);
2343                                         m = args->m;
2344                                 }
2345                                 /* FALLTHROUGH */
2346 #endif
2347                         case O_DENY:
2348                                 retval = IP_FW_DENY;
2349                                 l = 0;          /* exit inner loop */
2350                                 done = 1;       /* exit outer loop */
2351                                 break;
2352
2353                         case O_FORWARD_IP:
2354                                 if (args->eh)   /* not valid on layer2 pkts */
2355                                         break;
2356                                 if (q == NULL || q->rule != f ||
2357                                     dyn_dir == MATCH_FORWARD) {
2358                                     struct sockaddr_in *sa;
2359
2360                                     sa = &(((ipfw_insn_sa *)cmd)->sa);
2361                                     if (sa->sin_addr.s_addr == INADDR_ANY) {
2362 #ifdef INET6
2363                                         /*
2364                                          * We use O_FORWARD_IP opcode for
2365                                          * fwd rule with tablearg, but tables
2366                                          * now support IPv6 addresses. And
2367                                          * when we are inspecting IPv6 packet,
2368                                          * we can use nh6 field from
2369                                          * table_value as next_hop6 address.
2370                                          */
2371                                         if (is_ipv6) {
2372                                                 struct sockaddr_in6 *sa6;
2373
2374                                                 sa6 = args->next_hop6 =
2375                                                     &args->hopstore6;
2376                                                 sa6->sin6_family = AF_INET6;
2377                                                 sa6->sin6_len = sizeof(*sa6);
2378                                                 sa6->sin6_addr = TARG_VAL(
2379                                                     chain, tablearg, nh6);
2380                                                 /*
2381                                                  * Set sin6_scope_id only for
2382                                                  * link-local unicast addresses.
2383                                                  */
2384                                                 if (IN6_IS_ADDR_LINKLOCAL(
2385                                                     &sa6->sin6_addr))
2386                                                         sa6->sin6_scope_id =
2387                                                             TARG_VAL(chain,
2388                                                                 tablearg,
2389                                                                 zoneid);
2390                                         } else
2391 #endif
2392                                         {
2393                                                 sa = args->next_hop =
2394                                                     &args->hopstore;
2395                                                 sa->sin_family = AF_INET;
2396                                                 sa->sin_len = sizeof(*sa);
2397                                                 sa->sin_addr.s_addr = htonl(
2398                                                     TARG_VAL(chain, tablearg,
2399                                                     nh4));
2400                                         }
2401                                     } else {
2402                                         args->next_hop = sa;
2403                                     }
2404                                 }
2405                                 retval = IP_FW_PASS;
2406                                 l = 0;          /* exit inner loop */
2407                                 done = 1;       /* exit outer loop */
2408                                 break;
2409
2410 #ifdef INET6
2411                         case O_FORWARD_IP6:
2412                                 if (args->eh)   /* not valid on layer2 pkts */
2413                                         break;
2414                                 if (q == NULL || q->rule != f ||
2415                                     dyn_dir == MATCH_FORWARD) {
2416                                         struct sockaddr_in6 *sin6;
2417
2418                                         sin6 = &(((ipfw_insn_sa6 *)cmd)->sa);
2419                                         args->next_hop6 = sin6;
2420                                 }
2421                                 retval = IP_FW_PASS;
2422                                 l = 0;          /* exit inner loop */
2423                                 done = 1;       /* exit outer loop */
2424                                 break;
2425 #endif
2426
2427                         case O_NETGRAPH:
2428                         case O_NGTEE:
2429                                 set_match(args, f_pos, chain);
2430                                 args->rule.info = TARG(cmd->arg1, netgraph);
2431                                 if (V_fw_one_pass)
2432                                         args->rule.info |= IPFW_ONEPASS;
2433                                 retval = (cmd->opcode == O_NETGRAPH) ?
2434                                     IP_FW_NETGRAPH : IP_FW_NGTEE;
2435                                 l = 0;          /* exit inner loop */
2436                                 done = 1;       /* exit outer loop */
2437                                 break;
2438
2439                         case O_SETFIB: {
2440                                 uint32_t fib;
2441
2442                                 IPFW_INC_RULE_COUNTER(f, pktlen);
2443                                 fib = TARG(cmd->arg1, fib) & 0x7FFF;
2444                                 if (fib >= rt_numfibs)
2445                                         fib = 0;
2446                                 M_SETFIB(m, fib);
2447                                 args->f_id.fib = fib;
2448                                 l = 0;          /* exit inner loop */
2449                                 break;
2450                         }
2451
2452                         case O_SETDSCP: {
2453                                 uint16_t code;
2454
2455                                 code = TARG(cmd->arg1, dscp) & 0x3F;
2456                                 l = 0;          /* exit inner loop */
2457                                 if (is_ipv4) {
2458                                         uint16_t old;
2459
2460                                         old = *(uint16_t *)ip;
2461                                         ip->ip_tos = (code << 2) |
2462                                             (ip->ip_tos & 0x03);
2463                                         ip->ip_sum = cksum_adjust(ip->ip_sum,
2464                                             old, *(uint16_t *)ip);
2465                                 } else if (is_ipv6) {
2466                                         uint8_t *v;
2467
2468                                         v = &((struct ip6_hdr *)ip)->ip6_vfc;
2469                                         *v = (*v & 0xF0) | (code >> 2);
2470                                         v++;
2471                                         *v = (*v & 0x3F) | ((code & 0x03) << 6);
2472                                 } else
2473                                         break;
2474
2475                                 IPFW_INC_RULE_COUNTER(f, pktlen);
2476                                 break;
2477                         }
2478
2479                         case O_NAT:
2480                                 l = 0;          /* exit inner loop */
2481                                 done = 1;       /* exit outer loop */
2482                                 if (!IPFW_NAT_LOADED) {
2483                                     retval = IP_FW_DENY;
2484                                     break;
2485                                 }
2486
2487                                 struct cfg_nat *t;
2488                                 int nat_id;
2489
2490                                 set_match(args, f_pos, chain);
2491                                 /* Check if this is 'global' nat rule */
2492                                 if (cmd->arg1 == 0) {
2493                                         retval = ipfw_nat_ptr(args, NULL, m);
2494                                         break;
2495                                 }
2496                                 t = ((ipfw_insn_nat *)cmd)->nat;
2497                                 if (t == NULL) {
2498                                         nat_id = TARG(cmd->arg1, nat);
2499                                         t = (*lookup_nat_ptr)(&chain->nat, nat_id);
2500
2501                                         if (t == NULL) {
2502                                             retval = IP_FW_DENY;
2503                                             break;
2504                                         }
2505                                         if (cmd->arg1 != IP_FW_TARG)
2506                                             ((ipfw_insn_nat *)cmd)->nat = t;
2507                                 }
2508                                 retval = ipfw_nat_ptr(args, t, m);
2509                                 break;
2510
2511                         case O_REASS: {
2512                                 int ip_off;
2513
2514                                 IPFW_INC_RULE_COUNTER(f, pktlen);
2515                                 l = 0;  /* in any case exit inner loop */
2516                                 ip_off = ntohs(ip->ip_off);
2517
2518                                 /* if not fragmented, go to next rule */
2519                                 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0)
2520                                     break;
2521
2522                                 args->m = m = ip_reass(m);
2523
2524                                 /*
2525                                  * do IP header checksum fixup.
2526                                  */
2527                                 if (m == NULL) { /* fragment got swallowed */
2528                                     retval = IP_FW_DENY;
2529                                 } else { /* good, packet complete */
2530                                     int hlen;
2531
2532                                     ip = mtod(m, struct ip *);
2533                                     hlen = ip->ip_hl << 2;
2534                                     ip->ip_sum = 0;
2535                                     if (hlen == sizeof(struct ip))
2536                                         ip->ip_sum = in_cksum_hdr(ip);
2537                                     else
2538                                         ip->ip_sum = in_cksum(m, hlen);
2539                                     retval = IP_FW_REASS;
2540                                     set_match(args, f_pos, chain);
2541                                 }
2542                                 done = 1;       /* exit outer loop */
2543                                 break;
2544                         }
2545                         case O_EXTERNAL_ACTION:
2546                                 l = 0; /* in any case exit inner loop */
2547                                 retval = ipfw_run_eaction(chain, args,
2548                                     cmd, &done);
2549                                 break;
2550
2551                         default:
2552                                 panic("-- unknown opcode %d\n", cmd->opcode);
2553                         } /* end of switch() on opcodes */
2554                         /*
2555                          * if we get here with l=0, then match is irrelevant.
2556                          */
2557
2558                         if (cmd->len & F_NOT)
2559                                 match = !match;
2560
2561                         if (match) {
2562                                 if (cmd->len & F_OR)
2563                                         skip_or = 1;
2564                         } else {
2565                                 if (!(cmd->len & F_OR)) /* not an OR block, */
2566                                         break;          /* try next rule    */
2567                         }
2568
2569                 }       /* end of inner loop, scan opcodes */
2570 #undef PULLUP_LEN
2571
2572                 if (done)
2573                         break;
2574
2575 /* next_rule:; */       /* try next rule                */
2576
2577         }               /* end of outer for, scan rules */
2578
2579         if (done) {
2580                 struct ip_fw *rule = chain->map[f_pos];
2581                 /* Update statistics */
2582                 IPFW_INC_RULE_COUNTER(rule, pktlen);
2583         } else {
2584                 retval = IP_FW_DENY;
2585                 printf("ipfw: ouch!, skip past end of rules, denying packet\n");
2586         }
2587         IPFW_PF_RUNLOCK(chain);
2588 #ifdef __FreeBSD__
2589         if (ucred_cache != NULL)
2590                 crfree(ucred_cache);
2591 #endif
2592         return (retval);
2593
2594 pullup_failed:
2595         if (V_fw_verbose)
2596                 printf("ipfw: pullup failed\n");
2597         return (IP_FW_DENY);
2598 }
2599
2600 /*
2601  * Set maximum number of tables that can be used in given VNET ipfw instance.
2602  */
2603 #ifdef SYSCTL_NODE
2604 static int
2605 sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS)
2606 {
2607         int error;
2608         unsigned int ntables;
2609
2610         ntables = V_fw_tables_max;
2611
2612         error = sysctl_handle_int(oidp, &ntables, 0, req);
2613         /* Read operation or some error */
2614         if ((error != 0) || (req->newptr == NULL))
2615                 return (error);
2616
2617         return (ipfw_resize_tables(&V_layer3_chain, ntables));
2618 }
2619
2620 /*
2621  * Switches table namespace between global and per-set.
2622  */
2623 static int
2624 sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS)
2625 {
2626         int error;
2627         unsigned int sets;
2628
2629         sets = V_fw_tables_sets;
2630
2631         error = sysctl_handle_int(oidp, &sets, 0, req);
2632         /* Read operation or some error */
2633         if ((error != 0) || (req->newptr == NULL))
2634                 return (error);
2635
2636         return (ipfw_switch_tables_namespace(&V_layer3_chain, sets));
2637 }
2638 #endif
2639
2640 /*
2641  * Module and VNET glue
2642  */
2643
2644 /*
2645  * Stuff that must be initialised only on boot or module load
2646  */
2647 static int
2648 ipfw_init(void)
2649 {
2650         int error = 0;
2651
2652         /*
2653          * Only print out this stuff the first time around,
2654          * when called from the sysinit code.
2655          */
2656         printf("ipfw2 "
2657 #ifdef INET6
2658                 "(+ipv6) "
2659 #endif
2660                 "initialized, divert %s, nat %s, "
2661                 "default to %s, logging ",
2662 #ifdef IPDIVERT
2663                 "enabled",
2664 #else
2665                 "loadable",
2666 #endif
2667 #ifdef IPFIREWALL_NAT
2668                 "enabled",
2669 #else
2670                 "loadable",
2671 #endif
2672                 default_to_accept ? "accept" : "deny");
2673
2674         /*
2675          * Note: V_xxx variables can be accessed here but the vnet specific
2676          * initializer may not have been called yet for the VIMAGE case.
2677          * Tuneables will have been processed. We will print out values for
2678          * the default vnet.
2679          * XXX This should all be rationalized AFTER 8.0
2680          */
2681         if (V_fw_verbose == 0)
2682                 printf("disabled\n");
2683         else if (V_verbose_limit == 0)
2684                 printf("unlimited\n");
2685         else
2686                 printf("limited to %d packets/entry by default\n",
2687                     V_verbose_limit);
2688
2689         /* Check user-supplied table count for validness */
2690         if (default_fw_tables > IPFW_TABLES_MAX)
2691           default_fw_tables = IPFW_TABLES_MAX;
2692
2693         ipfw_init_sopt_handler();
2694         ipfw_log_bpf(1); /* init */
2695         ipfw_iface_init();
2696         return (error);
2697 }
2698
2699 /*
2700  * Called for the removal of the last instance only on module unload.
2701  */
2702 static void
2703 ipfw_destroy(void)
2704 {
2705
2706         ipfw_iface_destroy();
2707         ipfw_log_bpf(0); /* uninit */
2708         ipfw_destroy_sopt_handler();
2709         printf("IP firewall unloaded\n");
2710 }
2711
2712 /*
2713  * Stuff that must be initialized for every instance
2714  * (including the first of course).
2715  */
2716 static int
2717 vnet_ipfw_init(const void *unused)
2718 {
2719         int error, first;
2720         struct ip_fw *rule = NULL;
2721         struct ip_fw_chain *chain;
2722
2723         chain = &V_layer3_chain;
2724
2725         first = IS_DEFAULT_VNET(curvnet) ? 1 : 0;
2726
2727         /* First set up some values that are compile time options */
2728         V_autoinc_step = 100;   /* bounded to 1..1000 in add_rule() */
2729         V_fw_deny_unknown_exthdrs = 1;
2730 #ifdef IPFIREWALL_VERBOSE
2731         V_fw_verbose = 1;
2732 #endif
2733 #ifdef IPFIREWALL_VERBOSE_LIMIT
2734         V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
2735 #endif
2736 #ifdef IPFIREWALL_NAT
2737         LIST_INIT(&chain->nat);
2738 #endif
2739
2740         /* Init shared services hash table */
2741         ipfw_init_srv(chain);
2742
2743         ipfw_init_obj_rewriter();
2744         ipfw_init_counters();
2745         /* insert the default rule and create the initial map */
2746         chain->n_rules = 1;
2747         chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_WAITOK | M_ZERO);
2748         rule = ipfw_alloc_rule(chain, sizeof(struct ip_fw));
2749
2750         /* Set initial number of tables */
2751         V_fw_tables_max = default_fw_tables;
2752         error = ipfw_init_tables(chain, first);
2753         if (error) {
2754                 printf("ipfw2: setting up tables failed\n");
2755                 free(chain->map, M_IPFW);
2756                 free(rule, M_IPFW);
2757                 return (ENOSPC);
2758         }
2759
2760         /* fill and insert the default rule */
2761         rule->act_ofs = 0;
2762         rule->rulenum = IPFW_DEFAULT_RULE;
2763         rule->cmd_len = 1;
2764         rule->set = RESVD_SET;
2765         rule->cmd[0].len = 1;
2766         rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY;
2767         chain->default_rule = chain->map[0] = rule;
2768         chain->id = rule->id = 1;
2769         /* Pre-calculate rules length for legacy dump format */
2770         chain->static_len = sizeof(struct ip_fw_rule0);
2771
2772         IPFW_LOCK_INIT(chain);
2773         ipfw_dyn_init(chain);
2774         ipfw_eaction_init(chain, first);
2775 #ifdef LINEAR_SKIPTO
2776         ipfw_init_skipto_cache(chain);
2777 #endif
2778
2779         /* First set up some values that are compile time options */
2780         V_ipfw_vnet_ready = 1;          /* Open for business */
2781
2782         /*
2783          * Hook the sockopt handler and pfil hooks for ipv4 and ipv6.
2784          * Even if the latter two fail we still keep the module alive
2785          * because the sockopt and layer2 paths are still useful.
2786          * ipfw[6]_hook return 0 on success, ENOENT on failure,
2787          * so we can ignore the exact return value and just set a flag.
2788          *
2789          * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so
2790          * changes in the underlying (per-vnet) variables trigger
2791          * immediate hook()/unhook() calls.
2792          * In layer2 we have the same behaviour, except that V_ether_ipfw
2793          * is checked on each packet because there are no pfil hooks.
2794          */
2795         V_ip_fw_ctl_ptr = ipfw_ctl3;
2796         error = ipfw_attach_hooks(1);
2797         return (error);
2798 }
2799
2800 /*
2801  * Called for the removal of each instance.
2802  */
2803 static int
2804 vnet_ipfw_uninit(const void *unused)
2805 {
2806         struct ip_fw *reap;
2807         struct ip_fw_chain *chain = &V_layer3_chain;
2808         int i, last;
2809
2810         V_ipfw_vnet_ready = 0; /* tell new callers to go away */
2811         /*
2812          * disconnect from ipv4, ipv6, layer2 and sockopt.
2813          * Then grab, release and grab again the WLOCK so we make
2814          * sure the update is propagated and nobody will be in.
2815          */
2816         (void)ipfw_attach_hooks(0 /* detach */);
2817         V_ip_fw_ctl_ptr = NULL;
2818
2819         last = IS_DEFAULT_VNET(curvnet) ? 1 : 0;
2820
2821         IPFW_UH_WLOCK(chain);
2822         IPFW_UH_WUNLOCK(chain);
2823
2824         ipfw_dyn_uninit(0);     /* run the callout_drain */
2825
2826         IPFW_UH_WLOCK(chain);
2827
2828         reap = NULL;
2829         IPFW_WLOCK(chain);
2830         for (i = 0; i < chain->n_rules; i++)
2831                 ipfw_reap_add(chain, &reap, chain->map[i]);
2832         free(chain->map, M_IPFW);
2833 #ifdef LINEAR_SKIPTO
2834         ipfw_destroy_skipto_cache(chain);
2835 #endif
2836         IPFW_WUNLOCK(chain);
2837         IPFW_UH_WUNLOCK(chain);
2838         ipfw_destroy_tables(chain, last);
2839         ipfw_eaction_uninit(chain, last);
2840         if (reap != NULL)
2841                 ipfw_reap_rules(reap);
2842         vnet_ipfw_iface_destroy(chain);
2843         ipfw_destroy_srv(chain);
2844         IPFW_LOCK_DESTROY(chain);
2845         ipfw_dyn_uninit(1);     /* free the remaining parts */
2846         ipfw_destroy_counters();
2847         ipfw_destroy_obj_rewriter();
2848         return (0);
2849 }
2850
2851 /*
2852  * Module event handler.
2853  * In general we have the choice of handling most of these events by the
2854  * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to
2855  * use the SYSINIT handlers as they are more capable of expressing the
2856  * flow of control during module and vnet operations, so this is just
2857  * a skeleton. Note there is no SYSINIT equivalent of the module
2858  * SHUTDOWN handler, but we don't have anything to do in that case anyhow.
2859  */
2860 static int
2861 ipfw_modevent(module_t mod, int type, void *unused)
2862 {
2863         int err = 0;
2864
2865         switch (type) {
2866         case MOD_LOAD:
2867                 /* Called once at module load or
2868                  * system boot if compiled in. */
2869                 break;
2870         case MOD_QUIESCE:
2871                 /* Called before unload. May veto unloading. */
2872                 break;
2873         case MOD_UNLOAD:
2874                 /* Called during unload. */
2875                 break;
2876         case MOD_SHUTDOWN:
2877                 /* Called during system shutdown. */
2878                 break;
2879         default:
2880                 err = EOPNOTSUPP;
2881                 break;
2882         }
2883         return err;
2884 }
2885
2886 static moduledata_t ipfwmod = {
2887         "ipfw",
2888         ipfw_modevent,
2889         0
2890 };
2891
2892 /* Define startup order. */
2893 #define IPFW_SI_SUB_FIREWALL    SI_SUB_PROTO_FIREWALL
2894 #define IPFW_MODEVENT_ORDER     (SI_ORDER_ANY - 255) /* On boot slot in here. */
2895 #define IPFW_MODULE_ORDER       (IPFW_MODEVENT_ORDER + 1) /* A little later. */
2896 #define IPFW_VNET_ORDER         (IPFW_MODEVENT_ORDER + 2) /* Later still. */
2897
2898 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER);
2899 FEATURE(ipfw_ctl3, "ipfw new sockopt calls");
2900 MODULE_VERSION(ipfw, 3);
2901 /* should declare some dependencies here */
2902
2903 /*
2904  * Starting up. Done in order after ipfwmod() has been called.
2905  * VNET_SYSINIT is also called for each existing vnet and each new vnet.
2906  */
2907 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
2908             ipfw_init, NULL);
2909 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
2910             vnet_ipfw_init, NULL);
2911
2912 /*
2913  * Closing up shop. These are done in REVERSE ORDER, but still
2914  * after ipfwmod() has been called. Not called on reboot.
2915  * VNET_SYSUNINIT is also called for each exiting vnet as it exits.
2916  * or when the module is unloaded.
2917  */
2918 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
2919             ipfw_destroy, NULL);
2920 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
2921             vnet_ipfw_uninit, NULL);
2922 /* end of file */