dummynet2/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: head/sys/netinet/ipfw/ip_fw2.c 200601 2009-12-16 10:48:40Z luigi $");
  28
  29 /*
  30  * The FreeBSD IP packet firewall, main file
  31  */
  32
  33 #if !defined(KLD_MODULE)
  34 #include "opt_ipfw.h"
  35 #include "opt_ipdivert.h"
  36 #include "opt_ipdn.h"
  37 #include "opt_inet.h"
  38 #ifndef INET
  39 #error IPFIREWALL requires INET.
  40 #endif /* INET */
  41 #endif
  42 #include "opt_inet6.h"
  43 #include "opt_ipsec.h"
  44
  45 #include <sys/param.h>
  46 #include <sys/systm.h>
  47 #include <sys/condvar.h>
  48 #include <sys/eventhandler.h>
  49 #include <sys/malloc.h>
  50 #include <sys/mbuf.h>
  51 #include <sys/kernel.h>
  52 #include <sys/lock.h>
  53 #include <sys/jail.h>
  54 #include <sys/module.h>
  55 #include <sys/priv.h>
  56 #include <sys/proc.h>
  57 #include <sys/rwlock.h>
  58 #include <sys/socket.h>
  59 #include <sys/socketvar.h>
  60 #include <sys/sysctl.h>
  61 #include <sys/syslog.h>
  62 #include <sys/ucred.h>
  63 #include <net/ethernet.h> /* for ETHERTYPE_IP */
  64 #include <net/if.h>
  65 #include <net/route.h>
  66 #include <net/pf_mtag.h>
  67 #include <net/vnet.h>
  68
  69 #include <netinet/in.h>
  70 #include <netinet/in_var.h>
  71 #include <netinet/in_pcb.h>
  72 #include <netinet/ip.h>
  73 #include <netinet/ip_var.h>
  74 #include <netinet/ip_icmp.h>
  75 #include <netinet/ip_fw.h>
  76 #include <netinet/ipfw/ip_fw_private.h>
  77 #include <netinet/ip_carp.h>
  78 #include <netinet/pim.h>
  79 #include <netinet/tcp_var.h>
  80 #include <netinet/udp.h>
  81 #include <netinet/udp_var.h>
  82 #include <netinet/sctp.h>
  83
  84 #include <netinet/ip6.h>
  85 #include <netinet/icmp6.h>
  86 #ifdef INET6
  87 #include <netinet6/scope6_var.h>
  88 #include <netinet6/ip6_var.h>
  89 #endif
  90
  91 #include <machine/in_cksum.h>   /* XXX for in_cksum */
  92
  93 #ifdef MAC
  94 #include <security/mac/mac_framework.h>
  95 #endif
  96
  97 /*
  98  * static variables followed by global ones.
  99  * All ipfw global variables are here.
 100  */
 101
 102 /* ipfw_vnet_ready controls when we are open for business */
 103 static VNET_DEFINE(int, ipfw_vnet_ready) = 0;
 104 #define V_ipfw_vnet_ready       VNET(ipfw_vnet_ready)
 105
 106 static VNET_DEFINE(int, fw_deny_unknown_exthdrs);
 107 #define V_fw_deny_unknown_exthdrs       VNET(fw_deny_unknown_exthdrs)
 108
 109 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
 110 static int default_to_accept = 1;
 111 #else
 112 static int default_to_accept;
 113 #endif
 114
 115 VNET_DEFINE(int, autoinc_step);
 116
 117 /*
 118  * Each rule belongs to one of 32 different sets (0..31).
 119  * The variable set_disable contains one bit per set.
 120  * If the bit is set, all rules in the corresponding set
 121  * are disabled. Set RESVD_SET(31) is reserved for the default rule
 122  * and rules that are not deleted by the flush command,
 123  * and CANNOT be disabled.
 124  * Rules in set RESVD_SET can only be deleted individually.
 125  */
 126 VNET_DEFINE(u_int32_t, set_disable);
 127 #define V_set_disable                   VNET(set_disable)
 128
 129 VNET_DEFINE(int, fw_verbose);
 130 /* counter for ipfw_log(NULL...) */
 131 VNET_DEFINE(u_int64_t, norule_counter);
 132 VNET_DEFINE(int, verbose_limit);
 133
 134 /* layer3_chain contains the list of rules for layer 3 */
 135 VNET_DEFINE(struct ip_fw_chain, layer3_chain);
 136
 137 ipfw_nat_t *ipfw_nat_ptr = NULL;
 138 struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int);
 139 ipfw_nat_cfg_t *ipfw_nat_cfg_ptr;
 140 ipfw_nat_cfg_t *ipfw_nat_del_ptr;
 141 ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr;
 142 ipfw_nat_cfg_t *ipfw_nat_get_log_ptr;
 143
 144 #ifdef SYSCTL_NODE
 145 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
 146 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, one_pass,
 147     CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0,
 148     "Only do a single pass through ipfw when using dummynet(4)");
 149 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step,
 150     CTLFLAG_RW, &VNET_NAME(autoinc_step), 0,
 151     "Rule number auto-increment step");
 152 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose,
 153     CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0,
 154     "Log matches to ipfw rules");
 155 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit,
 156     CTLFLAG_RW, &VNET_NAME(verbose_limit), 0,
 157     "Set upper limit of matches of ipfw rules logged");
 158 uint32_t dummy_def = IPFW_DEFAULT_RULE;
 159 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD,
 160     &dummy_def, 0,
 161     "The default/max possible rule number.");
 162 uint32_t dummy_tables_max = IPFW_TABLES_MAX;
 163 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, tables_max, CTLFLAG_RD,
 164     &dummy_tables_max, 0,
 165     "The maximum number of tables.");
 166 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN,
 167     &default_to_accept, 0,
 168     "Make the default rule accept all packets.");
 169 TUNABLE_INT("net.inet.ip.fw.default_to_accept", &default_to_accept);
 170 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, static_count,
 171     CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0,
 172     "Number of static rules");
 173
 174 #ifdef INET6
 175 SYSCTL_DECL(_net_inet6_ip6);
 176 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
 177 SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs,
 178     CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_deny_unknown_exthdrs), 0,
 179     "Deny packets with unknown IPv6 Extension Headers");
 180 #endif /* INET6 */
 181
 182 #endif /* SYSCTL_NODE */
 183
 184
 185 /*
 186  * Some macros used in the various matching options.
 187  * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T
 188  * Other macros just cast void * into the appropriate type
 189  */
 190 #define L3HDR(T, ip)    ((T *)((u_int32_t *)(ip) + (ip)->ip_hl))
 191 #define TCP(p)          ((struct tcphdr *)(p))
 192 #define SCTP(p)         ((struct sctphdr *)(p))
 193 #define UDP(p)          ((struct udphdr *)(p))
 194 #define ICMP(p)         ((struct icmphdr *)(p))
 195 #define ICMP6(p)        ((struct icmp6_hdr *)(p))
 196
 197 static __inline int
 198 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd)
 199 {
 200         int type = icmp->icmp_type;
 201
 202         return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) );
 203 }
 204
 205 #define TT      ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \
 206     (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) )
 207
 208 static int
 209 is_icmp_query(struct icmphdr *icmp)
 210 {
 211         int type = icmp->icmp_type;
 212
 213         return (type <= ICMP_MAXTYPE && (TT & (1<<type)) );
 214 }
 215 #undef TT
 216
 217 /*
 218  * The following checks use two arrays of 8 or 16 bits to store the
 219  * bits that we want set or clear, respectively. They are in the
 220  * low and high half of cmd->arg1 or cmd->d[0].
 221  *
 222  * We scan options and store the bits we find set. We succeed if
 223  *
 224  *      (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear
 225  *
 226  * The code is sometimes optimized not to store additional variables.
 227  */
 228
 229 static int
 230 flags_match(ipfw_insn *cmd, u_int8_t bits)
 231 {
 232         u_char want_clear;
 233         bits = ~bits;
 234
 235         if ( ((cmd->arg1 & 0xff) & bits) != 0)
 236                 return 0; /* some bits we want set were clear */
 237         want_clear = (cmd->arg1 >> 8) & 0xff;
 238         if ( (want_clear & bits) != want_clear)
 239                 return 0; /* some bits we want clear were set */
 240         return 1;
 241 }
 242
 243 static int
 244 ipopts_match(struct ip *ip, ipfw_insn *cmd)
 245 {
 246         int optlen, bits = 0;
 247         u_char *cp = (u_char *)(ip + 1);
 248         int x = (ip->ip_hl << 2) - sizeof (struct ip);
 249
 250         for (; x > 0; x -= optlen, cp += optlen) {
 251                 int opt = cp[IPOPT_OPTVAL];
 252
 253                 if (opt == IPOPT_EOL)
 254                         break;
 255                 if (opt == IPOPT_NOP)
 256                         optlen = 1;
 257                 else {
 258                         optlen = cp[IPOPT_OLEN];
 259                         if (optlen <= 0 || optlen > x)
 260                                 return 0; /* invalid or truncated */
 261                 }
 262                 switch (opt) {
 263
 264                 default:
 265                         break;
 266
 267                 case IPOPT_LSRR:
 268                         bits |= IP_FW_IPOPT_LSRR;
 269                         break;
 270
 271                 case IPOPT_SSRR:
 272                         bits |= IP_FW_IPOPT_SSRR;
 273                         break;
 274
 275                 case IPOPT_RR:
 276                         bits |= IP_FW_IPOPT_RR;
 277                         break;
 278
 279                 case IPOPT_TS:
 280                         bits |= IP_FW_IPOPT_TS;
 281                         break;
 282                 }
 283         }
 284         return (flags_match(cmd, bits));
 285 }
 286
 287 static int
 288 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd)
 289 {
 290         int optlen, bits = 0;
 291         u_char *cp = (u_char *)(tcp + 1);
 292         int x = (tcp->th_off << 2) - sizeof(struct tcphdr);
 293
 294         for (; x > 0; x -= optlen, cp += optlen) {
 295                 int opt = cp[0];
 296                 if (opt == TCPOPT_EOL)
 297                         break;
 298                 if (opt == TCPOPT_NOP)
 299                         optlen = 1;
 300                 else {
 301                         optlen = cp[1];
 302                         if (optlen <= 0)
 303                                 break;
 304                 }
 305
 306                 switch (opt) {
 307
 308                 default:
 309                         break;
 310
 311                 case TCPOPT_MAXSEG:
 312                         bits |= IP_FW_TCPOPT_MSS;
 313                         break;
 314
 315                 case TCPOPT_WINDOW:
 316                         bits |= IP_FW_TCPOPT_WINDOW;
 317                         break;
 318
 319                 case TCPOPT_SACK_PERMITTED:
 320                 case TCPOPT_SACK:
 321                         bits |= IP_FW_TCPOPT_SACK;
 322                         break;
 323
 324                 case TCPOPT_TIMESTAMP:
 325                         bits |= IP_FW_TCPOPT_TS;
 326                         break;
 327
 328                 }
 329         }
 330         return (flags_match(cmd, bits));
 331 }
 332
 333 static int
 334 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd)
 335 {
 336         if (ifp == NULL)        /* no iface with this packet, match fails */
 337                 return 0;
 338         /* Check by name or by IP address */
 339         if (cmd->name[0] != '\0') { /* match by name */
 340                 /* Check name */
 341                 if (cmd->p.glob) {
 342                         if (fnmatch(cmd->name, ifp->if_xname, 0) == 0)
 343                                 return(1);
 344                 } else {
 345                         if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0)
 346                                 return(1);
 347                 }
 348         } else {
 349 #if !defined( __linux__ ) && !defined( _WIN32 )
 350                 struct ifaddr *ia;
 351
 352                 if_addr_rlock(ifp);
 353                 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
 354                         if (ia->ifa_addr->sa_family != AF_INET)
 355                                 continue;
 356                         if (cmd->p.ip.s_addr == ((struct sockaddr_in *)
 357                             (ia->ifa_addr))->sin_addr.s_addr) {
 358                                 if_addr_runlock(ifp);
 359                                 return(1);      /* match */
 360                         }
 361                 }
 362                 if_addr_runlock(ifp);
 363 #endif
 364         }
 365         return(0);      /* no match, fail ... */
 366 }
 367
 368 /*
 369  * The verify_path function checks if a route to the src exists and
 370  * if it is reachable via ifp (when provided).
 371  *
 372  * The 'verrevpath' option checks that the interface that an IP packet
 373  * arrives on is the same interface that traffic destined for the
 374  * packet's source address would be routed out of.
 375  * The 'versrcreach' option just checks that the source address is
 376  * reachable via any route (except default) in the routing table.
 377  * These two are a measure to block forged packets. This is also
 378  * commonly known as "anti-spoofing" or Unicast Reverse Path
 379  * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs
 380  * is purposely reminiscent of the Cisco IOS command,
 381  *
 382  *   ip verify unicast reverse-path
 383  *   ip verify unicast source reachable-via any
 384  *
 385  * which implements the same functionality. But note that the syntax
 386  * is misleading, and the check may be performed on all IP packets
 387  * whether unicast, multicast, or broadcast.
 388  */
 389 static int
 390 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib)
 391 {
 392 #if defined( __linux__ ) || defined( _WIN32 )
 393         return 0;
 394 #else
 395         struct route ro;
 396         struct sockaddr_in *dst;
 397
 398         bzero(&ro, sizeof(ro));
 399
 400         dst = (struct sockaddr_in *)&(ro.ro_dst);
 401         dst->sin_family = AF_INET;
 402         dst->sin_len = sizeof(*dst);
 403         dst->sin_addr = src;
 404         in_rtalloc_ign(&ro, 0, fib);
 405
 406         if (ro.ro_rt == NULL)
 407                 return 0;
 408
 409         /*
 410          * If ifp is provided, check for equality with rtentry.
 411          * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
 412          * in order to pass packets injected back by if_simloop():
 413          * if useloopback == 1 routing entry (via lo0) for our own address
 414          * may exist, so we need to handle routing assymetry.
 415          */
 416         if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) {
 417                 RTFREE(ro.ro_rt);
 418                 return 0;
 419         }
 420
 421         /* if no ifp provided, check if rtentry is not default route */
 422         if (ifp == NULL &&
 423              satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) {
 424                 RTFREE(ro.ro_rt);
 425                 return 0;
 426         }
 427
 428         /* or if this is a blackhole/reject route */
 429         if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
 430                 RTFREE(ro.ro_rt);
 431                 return 0;
 432         }
 433
 434         /* found valid route */
 435         RTFREE(ro.ro_rt);
 436         return 1;
 437 #endif
 438 }
 439
 440 #ifdef INET6
 441 /*
 442  * ipv6 specific rules here...
 443  */
 444 static __inline int
 445 icmp6type_match (int type, ipfw_insn_u32 *cmd)
 446 {
 447         return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) );
 448 }
 449
 450 static int
 451 flow6id_match( int curr_flow, ipfw_insn_u32 *cmd )
 452 {
 453         int i;
 454         for (i=0; i <= cmd->o.arg1; ++i )
 455                 if (curr_flow == cmd->d[i] )
 456                         return 1;
 457         return 0;
 458 }
 459
 460 /* support for IP6_*_ME opcodes */
 461 static int
 462 search_ip6_addr_net (struct in6_addr * ip6_addr)
 463 {
 464         struct ifnet *mdc;
 465         struct ifaddr *mdc2;
 466         struct in6_ifaddr *fdm;
 467         struct in6_addr copia;
 468
 469         TAILQ_FOREACH(mdc, &V_ifnet, if_link) {
 470                 if_addr_rlock(mdc);
 471                 TAILQ_FOREACH(mdc2, &mdc->if_addrhead, ifa_link) {
 472                         if (mdc2->ifa_addr->sa_family == AF_INET6) {
 473                                 fdm = (struct in6_ifaddr *)mdc2;
 474                                 copia = fdm->ia_addr.sin6_addr;
 475                                 /* need for leaving scope_id in the sock_addr */
 476                                 in6_clearscope(&copia);
 477                                 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) {
 478                                         if_addr_runlock(mdc);
 479                                         return 1;
 480                                 }
 481                         }
 482                 }
 483                 if_addr_runlock(mdc);
 484         }
 485         return 0;
 486 }
 487
 488 static int
 489 verify_path6(struct in6_addr *src, struct ifnet *ifp)
 490 {
 491         struct route_in6 ro;
 492         struct sockaddr_in6 *dst;
 493
 494         bzero(&ro, sizeof(ro));
 495
 496         dst = (struct sockaddr_in6 * )&(ro.ro_dst);
 497         dst->sin6_family = AF_INET6;
 498         dst->sin6_len = sizeof(*dst);
 499         dst->sin6_addr = *src;
 500         /* XXX MRT 0 for ipv6 at this time */
 501         rtalloc_ign((struct route *)&ro, 0);
 502
 503         if (ro.ro_rt == NULL)
 504                 return 0;
 505
 506         /*
 507          * if ifp is provided, check for equality with rtentry
 508          * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
 509          * to support the case of sending packets to an address of our own.
 510          * (where the former interface is the first argument of if_simloop()
 511          *  (=ifp), the latter is lo0)
 512          */
 513         if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) {
 514                 RTFREE(ro.ro_rt);
 515                 return 0;
 516         }
 517
 518         /* if no ifp provided, check if rtentry is not default route */
 519         if (ifp == NULL &&
 520             IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) {
 521                 RTFREE(ro.ro_rt);
 522                 return 0;
 523         }
 524
 525         /* or if this is a blackhole/reject route */
 526         if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
 527                 RTFREE(ro.ro_rt);
 528                 return 0;
 529         }
 530
 531         /* found valid route */
 532         RTFREE(ro.ro_rt);
 533         return 1;
 534
 535 }
 536
 537 static int
 538 is_icmp6_query(int icmp6_type)
 539 {
 540         if ((icmp6_type <= ICMP6_MAXTYPE) &&
 541             (icmp6_type == ICMP6_ECHO_REQUEST ||
 542             icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
 543             icmp6_type == ICMP6_WRUREQUEST ||
 544             icmp6_type == ICMP6_FQDN_QUERY ||
 545             icmp6_type == ICMP6_NI_QUERY))
 546                 return (1);
 547
 548         return (0);
 549 }
 550
 551 static void
 552 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6)
 553 {
 554         struct mbuf *m;
 555
 556         m = args->m;
 557         if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) {
 558                 struct tcphdr *tcp;
 559                 tcp = (struct tcphdr *)((char *)ip6 + hlen);
 560
 561                 if ((tcp->th_flags & TH_RST) == 0) {
 562                         struct mbuf *m0;
 563                         m0 = ipfw_send_pkt(args->m, &(args->f_id),
 564                             ntohl(tcp->th_seq), ntohl(tcp->th_ack),
 565                             tcp->th_flags | TH_RST);
 566                         if (m0 != NULL)
 567                                 ip6_output(m0, NULL, NULL, 0, NULL, NULL,
 568                                     NULL);
 569                 }
 570                 FREE_PKT(m);
 571         } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */
 572 #if 0
 573                 /*
 574                  * Unlike above, the mbufs need to line up with the ip6 hdr,
 575                  * as the contents are read. We need to m_adj() the
 576                  * needed amount.
 577                  * The mbuf will however be thrown away so we can adjust it.
 578                  * Remember we did an m_pullup on it already so we
 579                  * can make some assumptions about contiguousness.
 580                  */
 581                 if (args->L3offset)
 582                         m_adj(m, args->L3offset);
 583 #endif
 584                 icmp6_error(m, ICMP6_DST_UNREACH, code, 0);
 585         } else
 586                 FREE_PKT(m);
 587
 588         args->m = NULL;
 589 }
 590
 591 #endif /* INET6 */
 592
 593
 594 /*
 595  * sends a reject message, consuming the mbuf passed as an argument.
 596  */
 597 static void
 598 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip)
 599 {
 600
 601 #if 0
 602         /* XXX When ip is not guaranteed to be at mtod() we will
 603          * need to account for this */
 604          * The mbuf will however be thrown away so we can adjust it.
 605          * Remember we did an m_pullup on it already so we
 606          * can make some assumptions about contiguousness.
 607          */
 608         if (args->L3offset)
 609                 m_adj(m, args->L3offset);
 610 #endif
 611         if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */
 612                 /* We need the IP header in host order for icmp_error(). */
 613                 SET_HOST_IPLEN(ip);
 614                 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
 615         } else if (args->f_id.proto == IPPROTO_TCP) {
 616                 struct tcphdr *const tcp =
 617                     L3HDR(struct tcphdr, mtod(args->m, struct ip *));
 618                 if ( (tcp->th_flags & TH_RST) == 0) {
 619                         struct mbuf *m;
 620                         m = ipfw_send_pkt(args->m, &(args->f_id),
 621                                 ntohl(tcp->th_seq), ntohl(tcp->th_ack),
 622                                 tcp->th_flags | TH_RST);
 623                         if (m != NULL)
 624                                 ip_output(m, NULL, NULL, 0, NULL, NULL);
 625                 }
 626                 FREE_PKT(args->m);
 627         } else
 628                 FREE_PKT(args->m);
 629         args->m = NULL;
 630 }
 631
 632 /*
 633  * Support for uid/gid/jail lookup. These tests are expensive
 634  * (because we may need to look into the list of active sockets)
 635  * so we cache the results. ugid_lookupp is 0 if we have not
 636  * yet done a lookup, 1 if we succeeded, and -1 if we tried
 637  * and failed. The function always returns the match value.
 638  * We could actually spare the variable and use *uc, setting
 639  * it to '(void *)check_uidgid if we have no info, NULL if
 640  * we tried and failed, or any other value if successful.
 641  */
 642 static int
 643 check_uidgid(ipfw_insn_u32 *insn, int proto, struct ifnet *oif,
 644     struct in_addr dst_ip, u_int16_t dst_port, struct in_addr src_ip,
 645     u_int16_t src_port, struct ucred **uc, int *ugid_lookupp,
 646     struct inpcb *inp)
 647 {
 648 #ifdef __linux__
 649         return cred_check(insn, proto, oif,
 650         dst_ip, dst_port, src_ip, src_port,
 651         (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb);
 652 #else  /* FreeBSD */
 653         struct inpcbinfo *pi;
 654         int wildcard;
 655         struct inpcb *pcb;
 656         int match;
 657
 658         /*
 659          * Check to see if the UDP or TCP stack supplied us with
 660          * the PCB. If so, rather then holding a lock and looking
 661          * up the PCB, we can use the one that was supplied.
 662          */
 663         if (inp && *ugid_lookupp == 0) {
 664                 INP_LOCK_ASSERT(inp);
 665                 if (inp->inp_socket != NULL) {
 666                         *uc = crhold(inp->inp_cred);
 667                         *ugid_lookupp = 1;
 668                 } else
 669                         *ugid_lookupp = -1;
 670         }
 671         /*
 672          * If we have already been here and the packet has no
 673          * PCB entry associated with it, then we can safely
 674          * assume that this is a no match.
 675          */
 676         if (*ugid_lookupp == -1)
 677                 return (0);
 678         if (proto == IPPROTO_TCP) {
 679                 wildcard = 0;
 680                 pi = &V_tcbinfo;
 681         } else if (proto == IPPROTO_UDP) {
 682                 wildcard = INPLOOKUP_WILDCARD;
 683                 pi = &V_udbinfo;
 684         } else
 685                 return 0;
 686         match = 0;
 687         if (*ugid_lookupp == 0) {
 688                 INP_INFO_RLOCK(pi);
 689                 pcb =  (oif) ?
 690                         in_pcblookup_hash(pi,
 691                                 dst_ip, htons(dst_port),
 692                                 src_ip, htons(src_port),
 693                                 wildcard, oif) :
 694                         in_pcblookup_hash(pi,
 695                                 src_ip, htons(src_port),
 696                                 dst_ip, htons(dst_port),
 697                                 wildcard, NULL);
 698                 if (pcb != NULL) {
 699                         *uc = crhold(pcb->inp_cred);
 700                         *ugid_lookupp = 1;
 701                 }
 702                 INP_INFO_RUNLOCK(pi);
 703                 if (*ugid_lookupp == 0) {
 704                         /*
 705                          * We tried and failed, set the variable to -1
 706                          * so we will not try again on this packet.
 707                          */
 708                         *ugid_lookupp = -1;
 709                         return (0);
 710                 }
 711         }
 712         if (insn->o.opcode == O_UID)
 713                 match = ((*uc)->cr_uid == (uid_t)insn->d[0]);
 714         else if (insn->o.opcode == O_GID)
 715                 match = groupmember((gid_t)insn->d[0], *uc);
 716         else if (insn->o.opcode == O_JAIL)
 717                 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]);
 718         return match;
 719 #endif
 720 }
 721
 722 /*
 723  * Helper function to set args with info on the rule after the matching
 724  * one. slot is precise, whereas we guess rule_id as they are
 725  * assigned sequentially.
 726  */
 727 static inline void
 728 set_match(struct ip_fw_args *args, int slot,
 729         struct ip_fw_chain *chain)
 730 {
 731         args->rule.chain_id = chain->id;
 732         args->rule.slot = slot + 1; /* we use 0 as a marker */
 733         args->rule.rule_id = 1 + chain->map[slot]->id;
 734         args->rule.rulenum = chain->map[slot]->rulenum;
 735 }
 736
 737 /*
 738  * The main check routine for the firewall.
 739  *
 740  * All arguments are in args so we can modify them and return them
 741  * back to the caller.
 742  *
 743  * Parameters:
 744  *
 745  *      args->m (in/out) The packet; we set to NULL when/if we nuke it.
 746  *              Starts with the IP header.
 747  *      args->eh (in)   Mac header if present, NULL for layer3 packet.
 748  *      args->L3offset  Number of bytes bypassed if we came from L2.
 749  *                      e.g. often sizeof(eh)  ** NOTYET **
 750  *      args->oif       Outgoing interface, NULL if packet is incoming.
 751  *              The incoming interface is in the mbuf. (in)
 752  *      args->divert_rule (in/out)
 753  *              Skip up to the first rule past this rule number;
 754  *              upon return, non-zero port number for divert or tee.
 755  *
 756  *      args->rule      Pointer to the last matching rule (in/out)
 757  *      args->next_hop  Socket we are forwarding to (out).
 758  *      args->f_id      Addresses grabbed from the packet (out)
 759  *      args->rule.info a cookie depending on rule action
 760  *
 761  * Return value:
 762  *
 763  *      IP_FW_PASS      the packet must be accepted
 764  *      IP_FW_DENY      the packet must be dropped
 765  *      IP_FW_DIVERT    divert packet, port in m_tag
 766  *      IP_FW_TEE       tee packet, port in m_tag
 767  *      IP_FW_DUMMYNET  to dummynet, pipe in args->cookie
 768  *      IP_FW_NETGRAPH  into netgraph, cookie args->cookie
 769  *              args->rule contains the matching rule,
 770  *              args->rule.info has additional information.
 771  *
 772  */
 773 int
 774 ipfw_chk(struct ip_fw_args *args)
 775 {
 776
 777         /*
 778          * Local variables holding state while processing a packet:
 779          *
 780          * IMPORTANT NOTE: to speed up the processing of rules, there
 781          * are some assumption on the values of the variables, which
 782          * are documented here. Should you change them, please check
 783          * the implementation of the various instructions to make sure
 784          * that they still work.
 785          *
 786          * args->eh     The MAC header. It is non-null for a layer2
 787          *      packet, it is NULL for a layer-3 packet.
 788          * **notyet**
 789          * args->L3offset Offset in the packet to the L3 (IP or equiv.) header.
 790          *
 791          * m | args->m  Pointer to the mbuf, as received from the caller.
 792          *      It may change if ipfw_chk() does an m_pullup, or if it
 793          *      consumes the packet because it calls send_reject().
 794          *      XXX This has to change, so that ipfw_chk() never modifies
 795          *      or consumes the buffer.
 796          * ip   is the beginning of the ip(4 or 6) header.
 797          *      Calculated by adding the L3offset to the start of data.
 798          *      (Until we start using L3offset, the packet is
 799          *      supposed to start with the ip header).
 800          */
 801         struct mbuf *m = args->m;
 802         struct ip *ip = mtod(m, struct ip *);
 803
 804         /*
 805          * For rules which contain uid/gid or jail constraints, cache
 806          * a copy of the users credentials after the pcb lookup has been
 807          * executed. This will speed up the processing of rules with
 808          * these types of constraints, as well as decrease contention
 809          * on pcb related locks.
 810          */
 811 #ifdef __linux__
 812         struct bsd_ucred ucred_cache;
 813 #else
 814         struct ucred *ucred_cache = NULL;
 815 #endif
 816         int ucred_lookup = 0;
 817
 818         /*
 819          * oif | args->oif      If NULL, ipfw_chk has been called on the
 820          *      inbound path (ether_input, ip_input).
 821          *      If non-NULL, ipfw_chk has been called on the outbound path
 822          *      (ether_output, ip_output).
 823          */
 824         struct ifnet *oif = args->oif;
 825
 826         int f_pos = 0;          /* index of current rule in the array */
 827         int retval = 0;
 828
 829         /*
 830          * hlen The length of the IP header.
 831          */
 832         u_int hlen = 0;         /* hlen >0 means we have an IP pkt */
 833
 834         /*
 835          * offset       The offset of a fragment. offset != 0 means that
 836          *      we have a fragment at this offset of an IPv4 packet.
 837          *      offset == 0 means that (if this is an IPv4 packet)
 838          *      this is the first or only fragment.
 839          *      For IPv6 offset == 0 means there is no Fragment Header.
 840          *      If offset != 0 for IPv6 always use correct mask to
 841          *      get the correct offset because we add IP6F_MORE_FRAG
 842          *      to be able to dectect the first fragment which would
 843          *      otherwise have offset = 0.
 844          */
 845         u_short offset = 0;
 846
 847         /*
 848          * Local copies of addresses. They are only valid if we have
 849          * an IP packet.
 850          *
 851          * proto        The protocol. Set to 0 for non-ip packets,
 852          *      or to the protocol read from the packet otherwise.
 853          *      proto != 0 means that we have an IPv4 packet.
 854          *
 855          * src_port, dst_port   port numbers, in HOST format. Only
 856          *      valid for TCP and UDP packets.
 857          *
 858          * src_ip, dst_ip       ip addresses, in NETWORK format.
 859          *      Only valid for IPv4 packets.
 860          */
 861         uint8_t proto;
 862         uint16_t src_port = 0, dst_port = 0;    /* NOTE: host format    */
 863         struct in_addr src_ip, dst_ip;          /* NOTE: network format */
 864         uint16_t iplen=0;
 865         int pktlen;
 866         uint16_t        etype = 0;      /* Host order stored ether type */
 867
 868         /*
 869          * dyn_dir = MATCH_UNKNOWN when rules unchecked,
 870          *      MATCH_NONE when checked and not matched (q = NULL),
 871          *      MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL)
 872          */
 873         int dyn_dir = MATCH_UNKNOWN;
 874         ipfw_dyn_rule *q = NULL;
 875         struct ip_fw_chain *chain = &V_layer3_chain;
 876
 877         /*
 878          * We store in ulp a pointer to the upper layer protocol header.
 879          * In the ipv4 case this is easy to determine from the header,
 880          * but for ipv6 we might have some additional headers in the middle.
 881          * ulp is NULL if not found.
 882          */
 883         void *ulp = NULL;               /* upper layer protocol pointer. */
 884         /* XXX ipv6 variables */
 885         int is_ipv6 = 0;
 886         u_int16_t ext_hd = 0;   /* bits vector for extension header filtering */
 887         /* end of ipv6 variables */
 888         int is_ipv4 = 0;
 889
 890         int done = 0;           /* flag to exit the outer loop */
 891
 892         if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready))
 893                 return (IP_FW_PASS);    /* accept */
 894
 895         dst_ip.s_addr = 0;              /* make sure it is initialized */
 896         src_ip.s_addr = 0;              /* make sure it is initialized */
 897         pktlen = m->m_pkthdr.len;
 898         args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */
 899         proto = args->f_id.proto = 0;   /* mark f_id invalid */
 900                 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */
 901
 902 /*
 903  * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous,
 904  * then it sets p to point at the offset "len" in the mbuf. WARNING: the
 905  * pointer might become stale after other pullups (but we never use it
 906  * this way).
 907  */
 908 #define PULLUP_TO(_len, p, T)                                   \
 909 do {                                                            \
 910         int x = (_len) + sizeof(T);                             \
 911         if ((m)->m_len < x) {                                   \
 912                 args->m = m = m_pullup(m, x);                   \
 913                 if (m == NULL)                                  \
 914                         goto pullup_failed;                     \
 915         }                                                       \
 916         p = (mtod(m, char *) + (_len));                         \
 917 } while (0)
 918
 919         /*
 920          * if we have an ether header,
 921          */
 922         if (args->eh)
 923                 etype = ntohs(args->eh->ether_type);
 924
 925         /* Identify IP packets and fill up variables. */
 926         if (pktlen >= sizeof(struct ip6_hdr) &&
 927             (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) {
 928                 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip;
 929                 is_ipv6 = 1;
 930                 args->f_id.addr_type = 6;
 931                 hlen = sizeof(struct ip6_hdr);
 932                 proto = ip6->ip6_nxt;
 933
 934                 /* Search extension headers to find upper layer protocols */
 935                 while (ulp == NULL) {
 936                         switch (proto) {
 937                         case IPPROTO_ICMPV6:
 938                                 PULLUP_TO(hlen, ulp, struct icmp6_hdr);
 939                                 args->f_id.flags = ICMP6(ulp)->icmp6_type;
 940                                 break;
 941
 942                         case IPPROTO_TCP:
 943                                 PULLUP_TO(hlen, ulp, struct tcphdr);
 944                                 dst_port = TCP(ulp)->th_dport;
 945                                 src_port = TCP(ulp)->th_sport;
 946                                 args->f_id.flags = TCP(ulp)->th_flags;
 947                                 break;
 948
 949                         case IPPROTO_SCTP:
 950                                 PULLUP_TO(hlen, ulp, struct sctphdr);
 951                                 src_port = SCTP(ulp)->src_port;
 952                                 dst_port = SCTP(ulp)->dest_port;
 953                                 break;
 954
 955                         case IPPROTO_UDP:
 956                                 PULLUP_TO(hlen, ulp, struct udphdr);
 957                                 dst_port = UDP(ulp)->uh_dport;
 958                                 src_port = UDP(ulp)->uh_sport;
 959                                 break;
 960
 961                         case IPPROTO_HOPOPTS:   /* RFC 2460 */
 962                                 PULLUP_TO(hlen, ulp, struct ip6_hbh);
 963                                 ext_hd |= EXT_HOPOPTS;
 964                                 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
 965                                 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
 966                                 ulp = NULL;
 967                                 break;
 968
 969                         case IPPROTO_ROUTING:   /* RFC 2460 */
 970                                 PULLUP_TO(hlen, ulp, struct ip6_rthdr);
 971                                 switch (((struct ip6_rthdr *)ulp)->ip6r_type) {
 972                                 case 0:
 973                                         ext_hd |= EXT_RTHDR0;
 974                                         break;
 975                                 case 2:
 976                                         ext_hd |= EXT_RTHDR2;
 977                                         break;
 978                                 default:
 979                                         printf("IPFW2: IPV6 - Unknown Routing "
 980                                             "Header type(%d)\n",
 981                                             ((struct ip6_rthdr *)ulp)->ip6r_type);
 982                                         if (V_fw_deny_unknown_exthdrs)
 983                                             return (IP_FW_DENY);
 984                                         break;
 985                                 }
 986                                 ext_hd |= EXT_ROUTING;
 987                                 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3;
 988                                 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt;
 989                                 ulp = NULL;
 990                                 break;
 991
 992                         case IPPROTO_FRAGMENT:  /* RFC 2460 */
 993                                 PULLUP_TO(hlen, ulp, struct ip6_frag);
 994                                 ext_hd |= EXT_FRAGMENT;
 995                                 hlen += sizeof (struct ip6_frag);
 996                                 proto = ((struct ip6_frag *)ulp)->ip6f_nxt;
 997                                 offset = ((struct ip6_frag *)ulp)->ip6f_offlg &
 998                                         IP6F_OFF_MASK;
 999                                 /* Add IP6F_MORE_FRAG for offset of first
1000                                  * fragment to be != 0. */
1001                                 offset |= ((struct ip6_frag *)ulp)->ip6f_offlg &
1002                                         IP6F_MORE_FRAG;
1003                                 if (offset == 0) {
1004                                         printf("IPFW2: IPV6 - Invalid Fragment "
1005                                             "Header\n");
1006                                         if (V_fw_deny_unknown_exthdrs)
1007                                             return (IP_FW_DENY);
1008                                         break;
1009                                 }
1010                                 args->f_id.frag_id6 =
1011                                     ntohl(((struct ip6_frag *)ulp)->ip6f_ident);
1012                                 ulp = NULL;
1013                                 break;
1014
1015                         case IPPROTO_DSTOPTS:   /* RFC 2460 */
1016                                 PULLUP_TO(hlen, ulp, struct ip6_hbh);
1017                                 ext_hd |= EXT_DSTOPTS;
1018                                 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
1019                                 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
1020                                 ulp = NULL;
1021                                 break;
1022
1023                         case IPPROTO_AH:        /* RFC 2402 */
1024                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
1025                                 ext_hd |= EXT_AH;
1026                                 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2;
1027                                 proto = ((struct ip6_ext *)ulp)->ip6e_nxt;
1028                                 ulp = NULL;
1029                                 break;
1030
1031                         case IPPROTO_ESP:       /* RFC 2406 */
1032                                 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */
1033                                 /* Anything past Seq# is variable length and
1034                                  * data past this ext. header is encrypted. */
1035                                 ext_hd |= EXT_ESP;
1036                                 break;
1037
1038                         case IPPROTO_NONE:      /* RFC 2460 */
1039                                 /*
1040                                  * Packet ends here, and IPv6 header has
1041                                  * already been pulled up. If ip6e_len!=0
1042                                  * then octets must be ignored.
1043                                  */
1044                                 ulp = ip; /* non-NULL to get out of loop. */
1045                                 break;
1046
1047                         case IPPROTO_OSPFIGP:
1048                                 /* XXX OSPF header check? */
1049                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
1050                                 break;
1051
1052                         case IPPROTO_PIM:
1053                                 /* XXX PIM header check? */
1054                                 PULLUP_TO(hlen, ulp, struct pim);
1055                                 break;
1056
1057                         case IPPROTO_CARP:
1058                                 PULLUP_TO(hlen, ulp, struct carp_header);
1059                                 if (((struct carp_header *)ulp)->carp_version !=
1060                                     CARP_VERSION)
1061                                         return (IP_FW_DENY);
1062                                 if (((struct carp_header *)ulp)->carp_type !=
1063                                     CARP_ADVERTISEMENT)
1064                                         return (IP_FW_DENY);
1065                                 break;
1066
1067                         case IPPROTO_IPV6:      /* RFC 2893 */
1068                                 PULLUP_TO(hlen, ulp, struct ip6_hdr);
1069                                 break;
1070
1071                         case IPPROTO_IPV4:      /* RFC 2893 */
1072                                 PULLUP_TO(hlen, ulp, struct ip);
1073                                 break;
1074
1075                         default:
1076                                 printf("IPFW2: IPV6 - Unknown Extension "
1077                                     "Header(%d), ext_hd=%x\n", proto, ext_hd);
1078                                 if (V_fw_deny_unknown_exthdrs)
1079                                     return (IP_FW_DENY);
1080                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
1081                                 break;
1082                         } /*switch */
1083                 }
1084                 ip = mtod(m, struct ip *);
1085                 ip6 = (struct ip6_hdr *)ip;
1086                 args->f_id.src_ip6 = ip6->ip6_src;
1087                 args->f_id.dst_ip6 = ip6->ip6_dst;
1088                 args->f_id.src_ip = 0;
1089                 args->f_id.dst_ip = 0;
1090                 args->f_id.flow_id6 = ntohl(ip6->ip6_flow);
1091         } else if (pktlen >= sizeof(struct ip) &&
1092             (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) {
1093                 is_ipv4 = 1;
1094                 hlen = ip->ip_hl << 2;
1095                 args->f_id.addr_type = 4;
1096
1097                 /*
1098                  * Collect parameters into local variables for faster matching.
1099                  */
1100                 proto = ip->ip_p;
1101                 src_ip = ip->ip_src;
1102                 dst_ip = ip->ip_dst;
1103                 offset = ntohs(ip->ip_off) & IP_OFFMASK;
1104                 iplen = ntohs(ip->ip_len);
1105                 pktlen = iplen < pktlen ? iplen : pktlen;
1106
1107                 if (offset == 0) {
1108                         switch (proto) {
1109                         case IPPROTO_TCP:
1110                                 PULLUP_TO(hlen, ulp, struct tcphdr);
1111                                 dst_port = TCP(ulp)->th_dport;
1112                                 src_port = TCP(ulp)->th_sport;
1113                                 args->f_id.flags = TCP(ulp)->th_flags;
1114                                 break;
1115
1116                         case IPPROTO_UDP:
1117                                 PULLUP_TO(hlen, ulp, struct udphdr);
1118                                 dst_port = UDP(ulp)->uh_dport;
1119                                 src_port = UDP(ulp)->uh_sport;
1120                                 break;
1121
1122                         case IPPROTO_ICMP:
1123                                 PULLUP_TO(hlen, ulp, struct icmphdr);
1124                                 args->f_id.flags = ICMP(ulp)->icmp_type;
1125                                 break;
1126
1127                         default:
1128                                 break;
1129                         }
1130                 }
1131
1132                 ip = mtod(m, struct ip *);
1133                 args->f_id.src_ip = ntohl(src_ip.s_addr);
1134                 args->f_id.dst_ip = ntohl(dst_ip.s_addr);
1135         }
1136 #undef PULLUP_TO
1137         if (proto) { /* we may have port numbers, store them */
1138                 args->f_id.proto = proto;
1139                 args->f_id.src_port = src_port = ntohs(src_port);
1140                 args->f_id.dst_port = dst_port = ntohs(dst_port);
1141         }
1142
1143         IPFW_RLOCK(chain);
1144         if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */
1145                 IPFW_RUNLOCK(chain);
1146                 return (IP_FW_PASS);    /* accept */
1147         }
1148         if (args->rule.slot) {
1149                 /*
1150                  * Packet has already been tagged as a result of a previous
1151                  * match on rule args->rule aka args->rule_id (PIPE, QUEUE,
1152                  * REASS, NETGRAPH, DIVERT/TEE...)
1153                  * Validate the slot and continue from the next one
1154                  * if still present, otherwise do a lookup.
1155                  */
1156                 f_pos = (args->rule.chain_id == chain->id) ?
1157                     args->rule.slot :
1158                     ipfw_find_rule(chain, args->rule.rulenum,
1159                         args->rule.rule_id);
1160         } else {
1161                 f_pos = 0;
1162         }
1163
1164         /*
1165          * Now scan the rules, and parse microinstructions for each rule.
1166          * We have two nested loops and an inner switch. Sometimes we
1167          * need to break out of one or both loops, or re-enter one of
1168          * the loops with updated variables. Loop variables are:
1169          *
1170          *      f_pos (outer loop) points to the current rule.
1171          *              On output it points to the matching rule.
1172          *      done (outer loop) is used as a flag to break the loop.
1173          *      l (inner loop)  residual length of current rule.
1174          *              cmd points to the current microinstruction.
1175          *
1176          * We break the inner loop by setting l=0 and possibly
1177          * cmdlen=0 if we don't want to advance cmd.
1178          * We break the outer loop by setting done=1
1179          * We can restart the inner loop by setting l>0 and f_pos, f, cmd
1180          * as needed.
1181          */
1182         for (; f_pos < chain->n_rules; f_pos++) {
1183                 ipfw_insn *cmd;
1184                 uint32_t tablearg = 0;
1185                 int l, cmdlen, skip_or; /* skip rest of OR block */
1186                 struct ip_fw *f;
1187
1188                 f = chain->map[f_pos];
1189                 if (V_set_disable & (1 << f->set) )
1190                         continue;
1191
1192                 skip_or = 0;
1193                 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ;
1194                     l -= cmdlen, cmd += cmdlen) {
1195                         int match;
1196
1197                         /*
1198                          * check_body is a jump target used when we find a
1199                          * CHECK_STATE, and need to jump to the body of
1200                          * the target rule.
1201                          */
1202
1203 /* check_body: */
1204                         cmdlen = F_LEN(cmd);
1205                         /*
1206                          * An OR block (insn_1 || .. || insn_n) has the
1207                          * F_OR bit set in all but the last instruction.
1208                          * The first match will set "skip_or", and cause
1209                          * the following instructions to be skipped until
1210                          * past the one with the F_OR bit clear.
1211                          */
1212                         if (skip_or) {          /* skip this instruction */
1213                                 if ((cmd->len & F_OR) == 0)
1214                                         skip_or = 0;    /* next one is good */
1215                                 continue;
1216                         }
1217                         match = 0; /* set to 1 if we succeed */
1218
1219                         switch (cmd->opcode) {
1220                         /*
1221                          * The first set of opcodes compares the packet's
1222                          * fields with some pattern, setting 'match' if a
1223                          * match is found. At the end of the loop there is
1224                          * logic to deal with F_NOT and F_OR flags associated
1225                          * with the opcode.
1226                          */
1227                         case O_NOP:
1228                                 match = 1;
1229                                 break;
1230
1231                         case O_FORWARD_MAC:
1232                                 printf("ipfw: opcode %d unimplemented\n",
1233                                     cmd->opcode);
1234                                 break;
1235
1236                         case O_GID:
1237                         case O_UID:
1238                         case O_JAIL:
1239                                 /*
1240                                  * We only check offset == 0 && proto != 0,
1241                                  * as this ensures that we have a
1242                                  * packet with the ports info.
1243                                  */
1244                                 if (offset!=0)
1245                                         break;
1246                                 if (is_ipv6) /* XXX to be fixed later */
1247                                         break;
1248                                 if (proto == IPPROTO_TCP ||
1249                                     proto == IPPROTO_UDP)
1250                                         match = check_uidgid(
1251                                                     (ipfw_insn_u32 *)cmd,
1252                                                     proto, oif,
1253                                                     dst_ip, dst_port,
1254                                                     src_ip, src_port, (void *)&ucred_cache,
1255                                                     &ucred_lookup, (struct inpcb *)args->m);
1256                                 break;
1257
1258                         case O_RECV:
1259                                 match = iface_match(m->m_pkthdr.rcvif,
1260                                     (ipfw_insn_if *)cmd);
1261                                 break;
1262
1263                         case O_XMIT:
1264                                 match = iface_match(oif, (ipfw_insn_if *)cmd);
1265                                 break;
1266
1267                         case O_VIA:
1268                                 match = iface_match(oif ? oif :
1269                                     m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd);
1270                                 break;
1271
1272                         case O_MACADDR2:
1273                                 if (args->eh != NULL) { /* have MAC header */
1274                                         u_int32_t *want = (u_int32_t *)
1275                                                 ((ipfw_insn_mac *)cmd)->addr;
1276                                         u_int32_t *mask = (u_int32_t *)
1277                                                 ((ipfw_insn_mac *)cmd)->mask;
1278                                         u_int32_t *hdr = (u_int32_t *)args->eh;
1279
1280                                         match =
1281                                             ( want[0] == (hdr[0] & mask[0]) &&
1282                                               want[1] == (hdr[1] & mask[1]) &&
1283                                               want[2] == (hdr[2] & mask[2]) );
1284                                 }
1285                                 break;
1286
1287                         case O_MAC_TYPE:
1288                                 if (args->eh != NULL) {
1289                                         u_int16_t *p =
1290                                             ((ipfw_insn_u16 *)cmd)->ports;
1291                                         int i;
1292
1293                                         for (i = cmdlen - 1; !match && i>0;
1294                                             i--, p += 2)
1295                                                 match = (etype >= p[0] &&
1296                                                     etype <= p[1]);
1297                                 }
1298                                 break;
1299
1300                         case O_FRAG:
1301                                 match = (offset != 0);
1302                                 break;
1303
1304                         case O_IN:      /* "out" is "not in" */
1305                                 match = (oif == NULL);
1306                                 break;
1307
1308                         case O_LAYER2:
1309                                 match = (args->eh != NULL);
1310                                 break;
1311
1312                         case O_DIVERTED:
1313                             {
1314                                 /* For diverted packets, args->rule.info
1315                                  * contains the divert port (in host format)
1316                                  * reason and direction.
1317                                  */
1318                                 uint32_t i = args->rule.info;
1319                                 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT &&
1320                                     cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2);
1321                             }
1322                                 break;
1323
1324                         case O_PROTO:
1325                                 /*
1326                                  * We do not allow an arg of 0 so the
1327                                  * check of "proto" only suffices.
1328                                  */
1329                                 match = (proto == cmd->arg1);
1330                                 break;
1331
1332                         case O_IP_SRC:
1333                                 match = is_ipv4 &&
1334                                     (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1335                                     src_ip.s_addr);
1336                                 break;
1337
1338                         case O_IP_SRC_LOOKUP:
1339                         case O_IP_DST_LOOKUP:
1340                                 if (is_ipv4) {
1341                                     uint32_t key =
1342                                         (cmd->opcode == O_IP_DST_LOOKUP) ?
1343                                             dst_ip.s_addr : src_ip.s_addr;
1344                                     uint32_t v = 0;
1345
1346                                     if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) {
1347                                         /* generic lookup. The key must be
1348                                          * in 32bit big-endian format.
1349                                          */
1350                                         v = ((ipfw_insn_u32 *)cmd)->d[1];
1351                                         if (v == 0)
1352                                             key = dst_ip.s_addr;
1353                                         else if (v == 1)
1354                                             key = src_ip.s_addr;
1355                                         else if (offset != 0)
1356                                             break;
1357                                         else if (proto != IPPROTO_TCP &&
1358                                                 proto != IPPROTO_UDP)
1359                                             break;
1360                                         else if (v == 2)
1361                                             key = htonl(dst_port);
1362                                         else if (v == 3)
1363                                             key = htonl(src_port);
1364                                         else if (v == 4 || v == 5) {
1365                                             check_uidgid(
1366                                                 (ipfw_insn_u32 *)cmd,
1367                                                 proto, oif,
1368                                                 dst_ip, dst_port,
1369                                                 src_ip, src_port, (void *)&ucred_cache,
1370                                                 &ucred_lookup, (struct inpcb *)args->m);
1371 #ifdef __linux__
1372                                             if (v ==4 /* O_UID */)
1373                                                 key = ucred_cache.uid;
1374                                             else if (v == 5 /* O_JAIL */)
1375                                                 key = ucred_cache.xid;
1376 #else
1377                                             if (v == 4 /* O_UID */)
1378                                                 key = ucred_cache->cr_uid;
1379                                             else if (v == 5 /* O_JAIL */)
1380                                                 key = ucred_cache->cr_prison->pr_id;
1381 #endif
1382                                             key = htonl(key);
1383                                         } else
1384                                             break;
1385                                     }
1386                                     match = ipfw_lookup_table(chain,
1387                                         cmd->arg1, key, &v);
1388                                     if (!match)
1389                                         break;
1390                                     if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
1391                                         match =
1392                                             ((ipfw_insn_u32 *)cmd)->d[0] == v;
1393                                     else
1394                                         tablearg = v;
1395                                 }
1396                                 break;
1397
1398                         case O_IP_SRC_MASK:
1399                         case O_IP_DST_MASK:
1400                                 if (is_ipv4) {
1401                                     uint32_t a =
1402                                         (cmd->opcode == O_IP_DST_MASK) ?
1403                                             dst_ip.s_addr : src_ip.s_addr;
1404                                     uint32_t *p = ((ipfw_insn_u32 *)cmd)->d;
1405                                     int i = cmdlen-1;
1406
1407                                     for (; !match && i>0; i-= 2, p+= 2)
1408                                         match = (p[0] == (a & p[1]));
1409                                 }
1410                                 break;
1411
1412                         case O_IP_SRC_ME:
1413                                 if (is_ipv4) {
1414                                         struct ifnet *tif;
1415
1416                                         INADDR_TO_IFP(src_ip, tif);
1417                                         match = (tif != NULL);
1418                                 }
1419                                 break;
1420
1421                         case O_IP_DST_SET:
1422                         case O_IP_SRC_SET:
1423                                 if (is_ipv4) {
1424                                         u_int32_t *d = (u_int32_t *)(cmd+1);
1425                                         u_int32_t addr =
1426                                             cmd->opcode == O_IP_DST_SET ?
1427                                                 args->f_id.dst_ip :
1428                                                 args->f_id.src_ip;
1429
1430                                             if (addr < d[0])
1431                                                     break;
1432                                             addr -= d[0]; /* subtract base */
1433                                             match = (addr < cmd->arg1) &&
1434                                                 ( d[ 1 + (addr>>5)] &
1435                                                   (1<<(addr & 0x1f)) );
1436                                 }
1437                                 break;
1438
1439                         case O_IP_DST:
1440                                 match = is_ipv4 &&
1441                                     (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1442                                     dst_ip.s_addr);
1443                                 break;
1444
1445                         case O_IP_DST_ME:
1446                                 if (is_ipv4) {
1447                                         struct ifnet *tif;
1448
1449                                         INADDR_TO_IFP(dst_ip, tif);
1450                                         match = (tif != NULL);
1451                                 }
1452                                 break;
1453
1454                         case O_IP_SRCPORT:
1455                         case O_IP_DSTPORT:
1456                                 /*
1457                                  * offset == 0 && proto != 0 is enough
1458                                  * to guarantee that we have a
1459                                  * packet with port info.
1460                                  */
1461                                 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP)
1462                                     && offset == 0) {
1463                                         u_int16_t x =
1464                                             (cmd->opcode == O_IP_SRCPORT) ?
1465                                                 src_port : dst_port ;
1466                                         u_int16_t *p =
1467                                             ((ipfw_insn_u16 *)cmd)->ports;
1468                                         int i;
1469
1470                                         for (i = cmdlen - 1; !match && i>0;
1471                                             i--, p += 2)
1472                                                 match = (x>=p[0] && x<=p[1]);
1473                                 }
1474                                 break;
1475
1476                         case O_ICMPTYPE:
1477                                 match = (offset == 0 && proto==IPPROTO_ICMP &&
1478                                     icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) );
1479                                 break;
1480
1481 #ifdef INET6
1482                         case O_ICMP6TYPE:
1483                                 match = is_ipv6 && offset == 0 &&
1484                                     proto==IPPROTO_ICMPV6 &&
1485                                     icmp6type_match(
1486                                         ICMP6(ulp)->icmp6_type,
1487                                         (ipfw_insn_u32 *)cmd);
1488                                 break;
1489 #endif /* INET6 */
1490
1491                         case O_IPOPT:
1492                                 match = (is_ipv4 &&
1493                                     ipopts_match(ip, cmd) );
1494                                 break;
1495
1496                         case O_IPVER:
1497                                 match = (is_ipv4 &&
1498                                     cmd->arg1 == ip->ip_v);
1499                                 break;
1500
1501                         case O_IPID:
1502                         case O_IPLEN:
1503                         case O_IPTTL:
1504                                 if (is_ipv4) {  /* only for IP packets */
1505                                     uint16_t x;
1506                                     uint16_t *p;
1507                                     int i;
1508
1509                                     if (cmd->opcode == O_IPLEN)
1510                                         x = iplen;
1511                                     else if (cmd->opcode == O_IPTTL)
1512                                         x = ip->ip_ttl;
1513                                     else /* must be IPID */
1514                                         x = ntohs(ip->ip_id);
1515                                     if (cmdlen == 1) {
1516                                         match = (cmd->arg1 == x);
1517                                         break;
1518                                     }
1519                                     /* otherwise we have ranges */
1520                                     p = ((ipfw_insn_u16 *)cmd)->ports;
1521                                     i = cmdlen - 1;
1522                                     for (; !match && i>0; i--, p += 2)
1523                                         match = (x >= p[0] && x <= p[1]);
1524                                 }
1525                                 break;
1526
1527                         case O_IPPRECEDENCE:
1528                                 match = (is_ipv4 &&
1529                                     (cmd->arg1 == (ip->ip_tos & 0xe0)) );
1530                                 break;
1531
1532                         case O_IPTOS:
1533                                 match = (is_ipv4 &&
1534                                     flags_match(cmd, ip->ip_tos));
1535                                 break;
1536
1537                         case O_TCPDATALEN:
1538                                 if (proto == IPPROTO_TCP && offset == 0) {
1539                                     struct tcphdr *tcp;
1540                                     uint16_t x;
1541                                     uint16_t *p;
1542                                     int i;
1543
1544                                     tcp = TCP(ulp);
1545                                     x = iplen -
1546                                         ((ip->ip_hl + tcp->th_off) << 2);
1547                                     if (cmdlen == 1) {
1548                                         match = (cmd->arg1 == x);
1549                                         break;
1550                                     }
1551                                     /* otherwise we have ranges */
1552                                     p = ((ipfw_insn_u16 *)cmd)->ports;
1553                                     i = cmdlen - 1;
1554                                     for (; !match && i>0; i--, p += 2)
1555                                         match = (x >= p[0] && x <= p[1]);
1556                                 }
1557                                 break;
1558
1559                         case O_TCPFLAGS:
1560                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1561                                     flags_match(cmd, TCP(ulp)->th_flags));
1562                                 break;
1563
1564                         case O_TCPOPTS:
1565                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1566                                     tcpopts_match(TCP(ulp), cmd));
1567                                 break;
1568
1569                         case O_TCPSEQ:
1570                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1571                                     ((ipfw_insn_u32 *)cmd)->d[0] ==
1572                                         TCP(ulp)->th_seq);
1573                                 break;
1574
1575                         case O_TCPACK:
1576                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1577                                     ((ipfw_insn_u32 *)cmd)->d[0] ==
1578                                         TCP(ulp)->th_ack);
1579                                 break;
1580
1581                         case O_TCPWIN:
1582                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1583                                     cmd->arg1 == TCP(ulp)->th_win);
1584                                 break;
1585
1586                         case O_ESTAB:
1587                                 /* reject packets which have SYN only */
1588                                 /* XXX should i also check for TH_ACK ? */
1589                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1590                                     (TCP(ulp)->th_flags &
1591                                      (TH_RST | TH_ACK | TH_SYN)) != TH_SYN);
1592                                 break;
1593
1594                         case O_ALTQ: {
1595                                 struct pf_mtag *at;
1596                                 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd;
1597
1598                                 match = 1;
1599                                 at = pf_find_mtag(m);
1600                                 if (at != NULL && at->qid != 0)
1601                                         break;
1602                                 at = pf_get_mtag(m);
1603                                 if (at == NULL) {
1604                                         /*
1605                                          * Let the packet fall back to the
1606                                          * default ALTQ.
1607                                          */
1608                                         break;
1609                                 }
1610                                 at->qid = altq->qid;
1611                                 if (is_ipv4)
1612                                         at->af = AF_INET;
1613                                 else
1614                                         at->af = AF_LINK;
1615                                 at->hdr = ip;
1616                                 break;
1617                         }
1618
1619                         case O_LOG:
1620                                         ipfw_log(f, hlen, args, m,
1621                                             oif, offset, tablearg, ip);
1622                                 match = 1;
1623                                 break;
1624
1625                         case O_PROB:
1626                                 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]);
1627                                 break;
1628
1629                         case O_VERREVPATH:
1630                                 /* Outgoing packets automatically pass/match */
1631                                 match = ((oif != NULL) ||
1632                                     (m->m_pkthdr.rcvif == NULL) ||
1633                                     (
1634 #ifdef INET6
1635                                     is_ipv6 ?
1636                                         verify_path6(&(args->f_id.src_ip6),
1637                                             m->m_pkthdr.rcvif) :
1638 #endif
1639                                     verify_path(src_ip, m->m_pkthdr.rcvif,
1640                                         args->f_id.fib)));
1641                                 break;
1642
1643                         case O_VERSRCREACH:
1644                                 /* Outgoing packets automatically pass/match */
1645                                 match = (hlen > 0 && ((oif != NULL) ||
1646 #ifdef INET6
1647                                     is_ipv6 ?
1648                                         verify_path6(&(args->f_id.src_ip6),
1649                                             NULL) :
1650 #endif
1651                                     verify_path(src_ip, NULL, args->f_id.fib)));
1652                                 break;
1653
1654                         case O_ANTISPOOF:
1655                                 /* Outgoing packets automatically pass/match */
1656                                 if (oif == NULL && hlen > 0 &&
1657                                     (  (is_ipv4 && in_localaddr(src_ip))
1658 #ifdef INET6
1659                                     || (is_ipv6 &&
1660                                         in6_localaddr(&(args->f_id.src_ip6)))
1661 #endif
1662                                     ))
1663                                         match =
1664 #ifdef INET6
1665                                             is_ipv6 ? verify_path6(
1666                                                 &(args->f_id.src_ip6),
1667                                                 m->m_pkthdr.rcvif) :
1668 #endif
1669                                             verify_path(src_ip,
1670                                                 m->m_pkthdr.rcvif,
1671                                                 args->f_id.fib);
1672                                 else
1673                                         match = 1;
1674                                 break;
1675
1676                         case O_IPSEC:
1677 #ifdef IPSEC
1678                                 match = (m_tag_find(m,
1679                                     PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL);
1680 #endif
1681                                 /* otherwise no match */
1682                                 break;
1683
1684 #ifdef INET6
1685                         case O_IP6_SRC:
1686                                 match = is_ipv6 &&
1687                                     IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6,
1688                                     &((ipfw_insn_ip6 *)cmd)->addr6);
1689                                 break;
1690
1691                         case O_IP6_DST:
1692                                 match = is_ipv6 &&
1693                                 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6,
1694                                     &((ipfw_insn_ip6 *)cmd)->addr6);
1695                                 break;
1696                         case O_IP6_SRC_MASK:
1697                         case O_IP6_DST_MASK:
1698                                 if (is_ipv6) {
1699                                         int i = cmdlen - 1;
1700                                         struct in6_addr p;
1701                                         struct in6_addr *d =
1702                                             &((ipfw_insn_ip6 *)cmd)->addr6;
1703
1704                                         for (; !match && i > 0; d += 2,
1705                                             i -= F_INSN_SIZE(struct in6_addr)
1706                                             * 2) {
1707                                                 p = (cmd->opcode ==
1708                                                     O_IP6_SRC_MASK) ?
1709                                                     args->f_id.src_ip6:
1710                                                     args->f_id.dst_ip6;
1711                                                 APPLY_MASK(&p, &d[1]);
1712                                                 match =
1713                                                     IN6_ARE_ADDR_EQUAL(&d[0],
1714                                                     &p);
1715                                         }
1716                                 }
1717                                 break;
1718
1719                         case O_IP6_SRC_ME:
1720                                 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6);
1721                                 break;
1722
1723                         case O_IP6_DST_ME:
1724                                 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6);
1725                                 break;
1726
1727                         case O_FLOW6ID:
1728                                 match = is_ipv6 &&
1729                                     flow6id_match(args->f_id.flow_id6,
1730                                     (ipfw_insn_u32 *) cmd);
1731                                 break;
1732
1733                         case O_EXT_HDR:
1734                                 match = is_ipv6 &&
1735                                     (ext_hd & ((ipfw_insn *) cmd)->arg1);
1736                                 break;
1737
1738                         case O_IP6:
1739                                 match = is_ipv6;
1740                                 break;
1741 #endif
1742
1743                         case O_IP4:
1744                                 match = is_ipv4;
1745                                 break;
1746
1747                         case O_TAG: {
1748                                 struct m_tag *mtag;
1749                                 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ?
1750                                     tablearg : cmd->arg1;
1751
1752                                 /* Packet is already tagged with this tag? */
1753                                 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL);
1754
1755                                 /* We have `untag' action when F_NOT flag is
1756                                  * present. And we must remove this mtag from
1757                                  * mbuf and reset `match' to zero (`match' will
1758                                  * be inversed later).
1759                                  * Otherwise we should allocate new mtag and
1760                                  * push it into mbuf.
1761                                  */
1762                                 if (cmd->len & F_NOT) { /* `untag' action */
1763                                         if (mtag != NULL)
1764                                                 m_tag_delete(m, mtag);
1765                                         match = 0;
1766                                 } else if (mtag == NULL) {
1767                                         if ((mtag = m_tag_alloc(MTAG_IPFW,
1768                                             tag, 0, M_NOWAIT)) != NULL)
1769                                                 m_tag_prepend(m, mtag);
1770                                         match = 1;
1771                                 }
1772                                 break;
1773                         }
1774
1775                         case O_FIB: /* try match the specified fib */
1776                                 if (args->f_id.fib == cmd->arg1)
1777                                         match = 1;
1778                                 break;
1779
1780                         case O_TAGGED: {
1781                                 struct m_tag *mtag;
1782                                 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ?
1783                                     tablearg : cmd->arg1;
1784
1785                                 if (cmdlen == 1) {
1786                                         match = m_tag_locate(m, MTAG_IPFW,
1787                                             tag, NULL) != NULL;
1788                                         break;
1789                                 }
1790
1791                                 /* we have ranges */
1792                                 for (mtag = m_tag_first(m);
1793                                     mtag != NULL && !match;
1794                                     mtag = m_tag_next(m, mtag)) {
1795                                         uint16_t *p;
1796                                         int i;
1797
1798                                         if (mtag->m_tag_cookie != MTAG_IPFW)
1799                                                 continue;
1800
1801                                         p = ((ipfw_insn_u16 *)cmd)->ports;
1802                                         i = cmdlen - 1;
1803                                         for(; !match && i > 0; i--, p += 2)
1804                                                 match =
1805                                                     mtag->m_tag_id >= p[0] &&
1806                                                     mtag->m_tag_id <= p[1];
1807                                 }
1808                                 break;
1809                         }
1810
1811                         /*
1812                          * The second set of opcodes represents 'actions',
1813                          * i.e. the terminal part of a rule once the packet
1814                          * matches all previous patterns.
1815                          * Typically there is only one action for each rule,
1816                          * and the opcode is stored at the end of the rule
1817                          * (but there are exceptions -- see below).
1818                          *
1819                          * In general, here we set retval and terminate the
1820                          * outer loop (would be a 'break 3' in some language,
1821                          * but we need to set l=0, done=1)
1822                          *
1823                          * Exceptions:
1824                          * O_COUNT and O_SKIPTO actions:
1825                          *   instead of terminating, we jump to the next rule
1826                          *   (setting l=0), or to the SKIPTO target (setting
1827                          *   f/f_len, cmd and l as needed), respectively.
1828                          *
1829                          * O_TAG, O_LOG and O_ALTQ action parameters:
1830                          *   perform some action and set match = 1;
1831                          *
1832                          * O_LIMIT and O_KEEP_STATE: these opcodes are
1833                          *   not real 'actions', and are stored right
1834                          *   before the 'action' part of the rule.
1835                          *   These opcodes try to install an entry in the
1836                          *   state tables; if successful, we continue with
1837                          *   the next opcode (match=1; break;), otherwise
1838                          *   the packet must be dropped (set retval,
1839                          *   break loops with l=0, done=1)
1840                          *
1841                          * O_PROBE_STATE and O_CHECK_STATE: these opcodes
1842                          *   cause a lookup of the state table, and a jump
1843                          *   to the 'action' part of the parent rule
1844                          *   if an entry is found, or
1845                          *   (CHECK_STATE only) a jump to the next rule if
1846                          *   the entry is not found.
1847                          *   The result of the lookup is cached so that
1848                          *   further instances of these opcodes become NOPs.
1849                          *   The jump to the next rule is done by setting
1850                          *   l=0, cmdlen=0.
1851                          */
1852                         case O_LIMIT:
1853                         case O_KEEP_STATE:
1854                                 if (ipfw_install_state(f,
1855                                     (ipfw_insn_limit *)cmd, args, tablearg)) {
1856                                         /* error or limit violation */
1857                                         retval = IP_FW_DENY;
1858                                         l = 0;  /* exit inner loop */
1859                                         done = 1; /* exit outer loop */
1860                                 }
1861                                 match = 1;
1862                                 break;
1863
1864                         case O_PROBE_STATE:
1865                         case O_CHECK_STATE:
1866                                 /*
1867                                  * dynamic rules are checked at the first
1868                                  * keep-state or check-state occurrence,
1869                                  * with the result being stored in dyn_dir.
1870                                  * The compiler introduces a PROBE_STATE
1871                                  * instruction for us when we have a
1872                                  * KEEP_STATE (because PROBE_STATE needs
1873                                  * to be run first).
1874                                  */
1875                                 if (dyn_dir == MATCH_UNKNOWN &&
1876                                     (q = ipfw_lookup_dyn_rule(&args->f_id,
1877                                      &dyn_dir, proto == IPPROTO_TCP ?
1878                                         TCP(ulp) : NULL))
1879                                         != NULL) {
1880                                         /*
1881                                          * Found dynamic entry, update stats
1882                                          * and jump to the 'action' part of
1883                                          * the parent rule by setting
1884                                          * f, cmd, l and clearing cmdlen.
1885                                          */
1886                                         q->pcnt++;
1887                                         q->bcnt += pktlen;
1888                                         /* XXX we would like to have f_pos
1889                                          * readily accessible in the dynamic
1890                                          * rule, instead of having to
1891                                          * lookup q->rule.
1892                                          */
1893                                         f = q->rule;
1894                                         f_pos = ipfw_find_rule(chain,
1895                                                 f->rulenum, f->id);
1896                                         cmd = ACTION_PTR(f);
1897                                         l = f->cmd_len - f->act_ofs;
1898                                         ipfw_dyn_unlock();
1899                                         cmdlen = 0;
1900                                         match = 1;
1901                                         break;
1902                                 }
1903                                 /*
1904                                  * Dynamic entry not found. If CHECK_STATE,
1905                                  * skip to next rule, if PROBE_STATE just
1906                                  * ignore and continue with next opcode.
1907                                  */
1908                                 if (cmd->opcode == O_CHECK_STATE)
1909                                         l = 0;  /* exit inner loop */
1910                                 match = 1;
1911                                 break;
1912
1913                         case O_ACCEPT:
1914                                 retval = 0;     /* accept */
1915                                 l = 0;          /* exit inner loop */
1916                                 done = 1;       /* exit outer loop */
1917                                 break;
1918
1919                         case O_PIPE:
1920                         case O_QUEUE:
1921                                 set_match(args, f_pos, chain);
1922                                 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ?
1923                                         tablearg : cmd->arg1;
1924                                 if (cmd->opcode == O_PIPE)
1925                                         args->rule.info |= IPFW_IS_PIPE;
1926                                 if (V_fw_one_pass)
1927                                         args->rule.info |= IPFW_ONEPASS;
1928                                 retval = IP_FW_DUMMYNET;
1929                                 l = 0;          /* exit inner loop */
1930                                 done = 1;       /* exit outer loop */
1931                                 break;
1932
1933                         case O_DIVERT:
1934                         case O_TEE:
1935                                 if (args->eh) /* not on layer 2 */
1936                                     break;
1937                                 /* otherwise this is terminal */
1938                                 l = 0;          /* exit inner loop */
1939                                 done = 1;       /* exit outer loop */
1940                                 retval = (cmd->opcode == O_DIVERT) ?
1941                                         IP_FW_DIVERT : IP_FW_TEE;
1942                                 set_match(args, f_pos, chain);
1943                                 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ?
1944                                     tablearg : cmd->arg1;
1945                                 break;
1946
1947                         case O_COUNT:
1948                                 f->pcnt++;      /* update stats */
1949                                 f->bcnt += pktlen;
1950                                 f->timestamp = time_uptime;
1951                                 l = 0;          /* exit inner loop */
1952                                 break;
1953
1954                         case O_SKIPTO:
1955                                 f->pcnt++;      /* update stats */
1956                                 f->bcnt += pktlen;
1957                                 f->timestamp = time_uptime;
1958                             /* If possible use cached f_pos (in f->next_rule),
1959                              * whose version is written in f->next_rule
1960                              * (horrible hacks to avoid changing the ABI).
1961                              */
1962                             if (cmd->arg1 != IP_FW_TABLEARG &&
1963                                     (uintptr_t)f->x_next == chain->id) {
1964                                 f_pos = (uintptr_t)f->next_rule;
1965                                 } else {
1966                                 int i = (cmd->arg1 == IP_FW_TABLEARG) ?
1967                                         tablearg : cmd->arg1;
1968                                 /* make sure we do not jump backward */
1969                                 if (i <= f->rulenum)
1970                                     i = f->rulenum + 1;
1971                                 f_pos = ipfw_find_rule(chain, i, 0);
1972                                 /* update the cache */
1973                                 if (cmd->arg1 != IP_FW_TABLEARG) {
1974                                     f->next_rule =
1975                                         (void *)(uintptr_t)f_pos;
1976                                     f->x_next =
1977                                         (void *)(uintptr_t)chain->id;
1978                                 }
1979                                 }
1980                                 /*
1981                              * Skip disabled rules, and re-enter
1982                              * the inner loop with the correct
1983                              * f_pos, f, l and cmd.
1984                                  * Also clear cmdlen and skip_or
1985                                  */
1986                             for (; f_pos < chain->n_rules - 1 &&
1987                                     (V_set_disable &
1988                                      (1 << chain->map[f_pos]->set));
1989                                     f_pos++)
1990                                 ;
1991                             /* prepare to enter the inner loop */
1992                             f = chain->map[f_pos];
1993                                         l = f->cmd_len;
1994                                         cmd = f->cmd;
1995                                 match = 1;
1996                                 cmdlen = 0;
1997                                 skip_or = 0;
1998                                 break;
1999
2000                         case O_REJECT:
2001                                 /*
2002                                  * Drop the packet and send a reject notice
2003                                  * if the packet is not ICMP (or is an ICMP
2004                                  * query), and it is not multicast/broadcast.
2005                                  */
2006                                 if (hlen > 0 && is_ipv4 && offset == 0 &&
2007                                     (proto != IPPROTO_ICMP ||
2008                                      is_icmp_query(ICMP(ulp))) &&
2009                                     !(m->m_flags & (M_BCAST|M_MCAST)) &&
2010                                     !IN_MULTICAST(ntohl(dst_ip.s_addr))) {
2011                                         send_reject(args, cmd->arg1, iplen, ip);
2012                                         m = args->m;
2013                                 }
2014                                 /* FALLTHROUGH */
2015 #ifdef INET6
2016                         case O_UNREACH6:
2017                                 if (hlen > 0 && is_ipv6 &&
2018                                     ((offset & IP6F_OFF_MASK) == 0) &&
2019                                     (proto != IPPROTO_ICMPV6 ||
2020                                      (is_icmp6_query(args->f_id.flags) == 1)) &&
2021                                     !(m->m_flags & (M_BCAST|M_MCAST)) &&
2022                                     !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) {
2023                                         send_reject6(
2024                                             args, cmd->arg1, hlen,
2025                                             (struct ip6_hdr *)ip);
2026                                         m = args->m;
2027                                 }
2028                                 /* FALLTHROUGH */
2029 #endif
2030                         case O_DENY:
2031                                 retval = IP_FW_DENY;
2032                                 l = 0;          /* exit inner loop */
2033                                 done = 1;       /* exit outer loop */
2034                                 break;
2035
2036                         case O_FORWARD_IP:
2037                                 if (args->eh)   /* not valid on layer2 pkts */
2038                                         break;
2039                                 if (!q || dyn_dir == MATCH_FORWARD) {
2040                                     struct sockaddr_in *sa;
2041                                     sa = &(((ipfw_insn_sa *)cmd)->sa);
2042                                     if (sa->sin_addr.s_addr == INADDR_ANY) {
2043                                         bcopy(sa, &args->hopstore,
2044                                                         sizeof(*sa));
2045                                         args->hopstore.sin_addr.s_addr =
2046                                                     htonl(tablearg);
2047                                         args->next_hop = &args->hopstore;
2048                                     } else {
2049                                         args->next_hop = sa;
2050                                     }
2051                                 }
2052                                 retval = IP_FW_PASS;
2053                                 l = 0;          /* exit inner loop */
2054                                 done = 1;       /* exit outer loop */
2055                                 break;
2056
2057                         case O_NETGRAPH:
2058                         case O_NGTEE:
2059                                 set_match(args, f_pos, chain);
2060                                 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ?
2061                                         tablearg : cmd->arg1;
2062                                 retval = (cmd->opcode == O_NETGRAPH) ?
2063                                     IP_FW_NETGRAPH : IP_FW_NGTEE;
2064                                 l = 0;          /* exit inner loop */
2065                                 done = 1;       /* exit outer loop */
2066                                 break;
2067
2068                         case O_SETFIB:
2069                                 f->pcnt++;      /* update stats */
2070                                 f->bcnt += pktlen;
2071                                 f->timestamp = time_uptime;
2072                                 M_SETFIB(m, cmd->arg1);
2073                                 args->f_id.fib = cmd->arg1;
2074                                 l = 0;          /* exit inner loop */
2075                                 break;
2076
2077                         case O_NAT:
2078                                 if (!IPFW_NAT_LOADED) {
2079                                     retval = IP_FW_DENY;
2080                                 } else {
2081                                     struct cfg_nat *t;
2082                                     int nat_id;
2083
2084                                     set_match(args, f_pos, chain);
2085                                     t = ((ipfw_insn_nat *)cmd)->nat;
2086                                     if (t == NULL) {
2087                                         nat_id = (cmd->arg1 == IP_FW_TABLEARG) ?
2088                                                 tablearg : cmd->arg1;
2089                                         t = (*lookup_nat_ptr)(&chain->nat, nat_id);
2090
2091                                         if (t == NULL) {
2092                                             retval = IP_FW_DENY;
2093                                             l = 0;      /* exit inner loop */
2094                                             done = 1;   /* exit outer loop */
2095                                             break;
2096                                         }
2097                                         if (cmd->arg1 != IP_FW_TABLEARG)
2098                                             ((ipfw_insn_nat *)cmd)->nat = t;
2099                                     }
2100                                     retval = ipfw_nat_ptr(args, t, m);
2101                                 }
2102                                 l = 0;          /* exit inner loop */
2103                                 done = 1;       /* exit outer loop */
2104                                 break;
2105
2106                         case O_REASS: {
2107                                 int ip_off;
2108
2109                                 f->pcnt++;
2110                                 f->bcnt += pktlen;
2111                                 l = 0;  /* in any case exit inner loop */
2112                                 ip_off = ntohs(ip->ip_off);
2113
2114                                 /* if not fragmented, go to next rule */
2115                                 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0)
2116                                     break;
2117                                 /*
2118                                  * ip_reass() expects len & off in host
2119                                  * byte order.
2120                                  */
2121                                 SET_HOST_IPLEN(ip);
2122
2123                                 args->m = m = ip_reass(m);
2124
2125                                 /*
2126                                  * do IP header checksum fixup.
2127                                  */
2128                                 if (m == NULL) { /* fragment got swallowed */
2129                                     retval = IP_FW_DENY;
2130                                 } else { /* good, packet complete */
2131                                     int hlen;
2132
2133                                     ip = mtod(m, struct ip *);
2134                                     hlen = ip->ip_hl << 2;
2135                                     SET_NET_IPLEN(ip);
2136                                     ip->ip_sum = 0;
2137                                     if (hlen == sizeof(struct ip))
2138                                         ip->ip_sum = in_cksum_hdr(ip);
2139                                     else
2140                                         ip->ip_sum = in_cksum(m, hlen);
2141                                     retval = IP_FW_REASS;
2142                                     set_match(args, f_pos, chain);
2143                                 }
2144                                 done = 1;       /* exit outer loop */
2145                                 break;
2146                         }
2147
2148                         default:
2149                                 panic("-- unknown opcode %d\n", cmd->opcode);
2150                         } /* end of switch() on opcodes */
2151                         /*
2152                          * if we get here with l=0, then match is irrelevant.
2153                          */
2154
2155                         if (cmd->len & F_NOT)
2156                                 match = !match;
2157
2158                         if (match) {
2159                                 if (cmd->len & F_OR)
2160                                         skip_or = 1;
2161                         } else {
2162                                 if (!(cmd->len & F_OR)) /* not an OR block, */
2163                                         break;          /* try next rule    */
2164                         }
2165
2166                 }       /* end of inner loop, scan opcodes */
2167
2168                 if (done)
2169                         break;
2170
2171 /* next_rule:; */       /* try next rule                */
2172
2173         }               /* end of outer for, scan rules */
2174
2175         if (done) {
2176                 struct ip_fw *rule = chain->map[f_pos];
2177                 /* Update statistics */
2178                 rule->pcnt++;
2179                 rule->bcnt += pktlen;
2180                 rule->timestamp = time_uptime;
2181         } else {
2182                 retval = IP_FW_DENY;
2183                 printf("ipfw: ouch!, skip past end of rules, denying packet\n");
2184         }
2185         IPFW_RUNLOCK(chain);
2186 #ifndef __linux__
2187         if (ucred_cache != NULL)
2188                 crfree(ucred_cache);
2189 #endif
2190         return (retval);
2191
2192 pullup_failed:
2193         if (V_fw_verbose)
2194                 printf("ipfw: pullup failed\n");
2195         return (IP_FW_DENY);
2196 }
2197
2198 /*
2199  * Module and VNET glue
2200  */
2201
2202 /*
2203  * Stuff that must be initialised only on boot or module load
2204  */
2205 static int
2206 ipfw_init(void)
2207 {
2208         int error = 0;
2209
2210         ipfw_dyn_attach();
2211         /*
2212          * Only print out this stuff the first time around,
2213          * when called from the sysinit code.
2214          */
2215         printf("ipfw2 "
2216 #ifdef INET6
2217                 "(+ipv6) "
2218 #endif
2219                 "initialized, divert %s, nat %s, "
2220                 "rule-based forwarding "
2221 #ifdef IPFIREWALL_FORWARD
2222                 "enabled, "
2223 #else
2224                 "disabled, "
2225 #endif
2226                 "default to %s, logging ",
2227 #ifdef IPDIVERT
2228                 "enabled",
2229 #else
2230                 "loadable",
2231 #endif
2232 #ifdef IPFIREWALL_NAT
2233                 "enabled",
2234 #else
2235                 "loadable",
2236 #endif
2237                 default_to_accept ? "accept" : "deny");
2238
2239         /*
2240          * Note: V_xxx variables can be accessed here but the vnet specific
2241          * initializer may not have been called yet for the VIMAGE case.
2242          * Tuneables will have been processed. We will print out values for
2243          * the default vnet.
2244          * XXX This should all be rationalized AFTER 8.0
2245          */
2246         if (V_fw_verbose == 0)
2247                 printf("disabled\n");
2248         else if (V_verbose_limit == 0)
2249                 printf("unlimited\n");
2250         else
2251                 printf("limited to %d packets/entry by default\n",
2252                     V_verbose_limit);
2253
2254         ipfw_log_bpf(1); /* init */
2255         return (error);
2256 }
2257
2258 /*
2259  * Called for the removal of the last instance only on module unload.
2260  */
2261 static void
2262 ipfw_destroy(void)
2263 {
2264
2265         ipfw_log_bpf(0); /* uninit */
2266         ipfw_dyn_detach();
2267         printf("IP firewall unloaded\n");
2268 }
2269
2270 /*
2271  * Stuff that must be initialized for every instance
2272  * (including the first of course).
2273  */
2274 static int
2275 vnet_ipfw_init(const void *unused)
2276 {
2277         int error;
2278         struct ip_fw *rule = NULL;
2279         struct ip_fw_chain *chain;
2280
2281         chain = &V_layer3_chain;
2282
2283         /* First set up some values that are compile time options */
2284         V_autoinc_step = 100;   /* bounded to 1..1000 in add_rule() */
2285         V_fw_deny_unknown_exthdrs = 1;
2286 #ifdef IPFIREWALL_VERBOSE
2287         V_fw_verbose = 1;
2288 #endif
2289 #ifdef IPFIREWALL_VERBOSE_LIMIT
2290         V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
2291 #endif
2292 #ifdef IPFIREWALL_NAT
2293         LIST_INIT(&chain->nat);
2294 #endif
2295
2296         /* insert the default rule and create the initial map */
2297         chain->n_rules = 1;
2298         chain->static_len = sizeof(struct ip_fw);
2299         chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_NOWAIT | M_ZERO);
2300         if (chain->map)
2301                 rule = malloc(chain->static_len, M_IPFW, M_NOWAIT | M_ZERO);
2302         if (rule == NULL) {
2303                 if (chain->map)
2304                         free(chain->map, M_IPFW);
2305                 printf("ipfw2: ENOSPC initializing default rule "
2306                         "(support disabled)\n");
2307                 return (ENOSPC);
2308         }
2309         error = ipfw_init_tables(chain);
2310         if (error) {
2311                 panic("init_tables"); /* XXX Marko fix this ! */
2312         }
2313
2314         /* fill and insert the default rule */
2315         rule->act_ofs = 0;
2316         rule->rulenum = IPFW_DEFAULT_RULE;
2317         rule->cmd_len = 1;
2318         rule->set = RESVD_SET;
2319         rule->cmd[0].len = 1;
2320         rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY;
2321         chain->rules = chain->default_rule = chain->map[0] = rule;
2322         chain->id = rule->id = 1;
2323
2324         IPFW_LOCK_INIT(chain);
2325         ipfw_dyn_init();
2326
2327         /* First set up some values that are compile time options */
2328         V_ipfw_vnet_ready = 1;          /* Open for business */
2329
2330         /*
2331          * Hook the sockopt handler, and the layer2 (V_ip_fw_chk_ptr)
2332          * and pfil hooks for ipv4 and ipv6. Even if the latter two fail
2333          * we still keep the module alive because the sockopt and
2334          * layer2 paths are still useful.
2335          * ipfw[6]_hook return 0 on success, ENOENT on failure,
2336          * so we can ignore the exact return value and just set a flag.
2337          *
2338          * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so
2339          * changes in the underlying (per-vnet) variables trigger
2340          * immediate hook()/unhook() calls.
2341          * In layer2 we have the same behaviour, except that V_ether_ipfw
2342          * is checked on each packet because there are no pfil hooks.
2343          */
2344         V_ip_fw_ctl_ptr = ipfw_ctl;
2345         V_ip_fw_chk_ptr = ipfw_chk;
2346         error = ipfw_attach_hooks(1);
2347         return (error);
2348 }
2349
2350 /*
2351  * Called for the removal of each instance.
2352  */
2353 static int
2354 vnet_ipfw_uninit(const void *unused)
2355 {
2356         struct ip_fw *reap, *rule;
2357         struct ip_fw_chain *chain = &V_layer3_chain;
2358         int i;
2359
2360         V_ipfw_vnet_ready = 0; /* tell new callers to go away */
2361         /*
2362          * disconnect from ipv4, ipv6, layer2 and sockopt.
2363          * Then grab, release and grab again the WLOCK so we make
2364          * sure the update is propagated and nobody will be in.
2365          */
2366         (void)ipfw_attach_hooks(0 /* detach */);
2367         V_ip_fw_chk_ptr = NULL;
2368         V_ip_fw_ctl_ptr = NULL;
2369         IPFW_UH_WLOCK(chain);
2370         IPFW_UH_WUNLOCK(chain);
2371         IPFW_UH_WLOCK(chain);
2372
2373         IPFW_WLOCK(chain);
2374         IPFW_WUNLOCK(chain);
2375         IPFW_WLOCK(chain);
2376
2377         ipfw_dyn_uninit(0);     /* run the callout_drain */
2378         ipfw_flush_tables(chain);
2379         reap = NULL;
2380         for (i = 0; i < chain->n_rules; i++) {
2381                 rule = chain->map[i];
2382                 rule->x_next = reap;
2383                 reap = rule;
2384         }
2385         if (chain->map)
2386                 free(chain->map, M_IPFW);
2387         IPFW_WUNLOCK(chain);
2388         IPFW_UH_WUNLOCK(chain);
2389         if (reap != NULL)
2390                 ipfw_reap_rules(reap);
2391         IPFW_LOCK_DESTROY(chain);
2392         ipfw_dyn_uninit(1);     /* free the remaining parts */
2393         return 0;
2394 }
2395
2396 /*
2397  * Module event handler.
2398  * In general we have the choice of handling most of these events by the
2399  * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to
2400  * use the SYSINIT handlers as they are more capable of expressing the
2401  * flow of control during module and vnet operations, so this is just
2402  * a skeleton. Note there is no SYSINIT equivalent of the module
2403  * SHUTDOWN handler, but we don't have anything to do in that case anyhow.
2404  */
2405 static int
2406 ipfw_modevent(module_t mod, int type, void *unused)
2407 {
2408         int err = 0;
2409
2410         switch (type) {
2411         case MOD_LOAD:
2412                 /* Called once at module load or
2413                  * system boot if compiled in. */
2414                 break;
2415         case MOD_QUIESCE:
2416                 /* Called before unload. May veto unloading. */
2417                 break;
2418         case MOD_UNLOAD:
2419                 /* Called during unload. */
2420                 break;
2421         case MOD_SHUTDOWN:
2422                 /* Called during system shutdown. */
2423                 break;
2424         default:
2425                 err = EOPNOTSUPP;
2426                 break;
2427         }
2428         return err;
2429 }
2430
2431 static moduledata_t ipfwmod = {
2432         "ipfw",
2433         ipfw_modevent,
2434         0
2435 };
2436
2437 /* Define startup order. */
2438 #define IPFW_SI_SUB_FIREWALL    SI_SUB_PROTO_IFATTACHDOMAIN
2439 #define IPFW_MODEVENT_ORDER     (SI_ORDER_ANY - 255) /* On boot slot in here. */
2440 #define IPFW_MODULE_ORDER       (IPFW_MODEVENT_ORDER + 1) /* A little later. */
2441 #define IPFW_VNET_ORDER         (IPFW_MODEVENT_ORDER + 2) /* Later still. */
2442
2443 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER);
2444 MODULE_VERSION(ipfw, 2);
2445 /* should declare some dependencies here */
2446
2447 /*
2448  * Starting up. Done in order after ipfwmod() has been called.
2449  * VNET_SYSINIT is also called for each existing vnet and each new vnet.
2450  */
2451 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
2452             ipfw_init, NULL);
2453 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
2454             vnet_ipfw_init, NULL);
2455
2456 /*
2457  * Closing up shop. These are done in REVERSE ORDER, but still
2458  * after ipfwmod() has been called. Not called on reboot.
2459  * VNET_SYSUNINIT is also called for each exiting vnet as it exits.
2460  * or when the module is unloaded.
2461  */
2462 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
2463             ipfw_destroy, NULL);
2464 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
2465             vnet_ipfw_uninit, NULL);
2466 /* end of file */