sys/netpfil/ipfw/ip_fw2.c

   1 /*-
   2  * Copyright (c) 2002-2009 Luigi Rizzo, Universita` di Pisa
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  23  * SUCH DAMAGE.
  24  */
  25
  26 #include <sys/cdefs.h>
  27 __FBSDID("$FreeBSD$");
  28
  29 /*
  30  * The FreeBSD IP packet firewall, main file
  31  */
  32
  33 #include "opt_ipfw.h"
  34 #include "opt_ipdivert.h"
  35 #include "opt_inet.h"
  36 #ifndef INET
  37 #error "IPFIREWALL requires INET"
  38 #endif /* INET */
  39 #include "opt_inet6.h"
  40 #include "opt_ipsec.h"
  41
  42 #include <sys/param.h>
  43 #include <sys/systm.h>
  44 #include <sys/condvar.h>
  45 #include <sys/eventhandler.h>
  46 #include <sys/malloc.h>
  47 #include <sys/mbuf.h>
  48 #include <sys/kernel.h>
  49 #include <sys/lock.h>
  50 #include <sys/jail.h>
  51 #include <sys/module.h>
  52 #include <sys/priv.h>
  53 #include <sys/proc.h>
  54 #include <sys/rwlock.h>
  55 #include <sys/socket.h>
  56 #include <sys/socketvar.h>
  57 #include <sys/sysctl.h>
  58 #include <sys/syslog.h>
  59 #include <sys/ucred.h>
  60 #include <net/ethernet.h> /* for ETHERTYPE_IP */
  61 #include <net/if.h>
  62 #include <net/route.h>
  63 #include <net/pfil.h>
  64 #include <net/vnet.h>
  65
  66 #include <netpfil/pf/pf_mtag.h>
  67
  68 #include <netinet/in.h>
  69 #include <netinet/in_var.h>
  70 #include <netinet/in_pcb.h>
  71 #include <netinet/ip.h>
  72 #include <netinet/ip_var.h>
  73 #include <netinet/ip_icmp.h>
  74 #include <netinet/ip_fw.h>
  75 #include <netinet/ip_carp.h>
  76 #include <netinet/pim.h>
  77 #include <netinet/tcp_var.h>
  78 #include <netinet/udp.h>
  79 #include <netinet/udp_var.h>
  80 #include <netinet/sctp.h>
  81
  82 #include <netinet/ip6.h>
  83 #include <netinet/icmp6.h>
  84 #ifdef INET6
  85 #include <netinet6/in6_pcb.h>
  86 #include <netinet6/scope6_var.h>
  87 #include <netinet6/ip6_var.h>
  88 #endif
  89
  90 #include <netpfil/ipfw/ip_fw_private.h>
  91
  92 #include <machine/in_cksum.h>   /* XXX for in_cksum */
  93
  94 #ifdef MAC
  95 #include <security/mac/mac_framework.h>
  96 #endif
  97
  98 /*
  99  * static variables followed by global ones.
 100  * All ipfw global variables are here.
 101  */
 102
 103 /* ipfw_vnet_ready controls when we are open for business */
 104 static VNET_DEFINE(int, ipfw_vnet_ready) = 0;
 105 #define V_ipfw_vnet_ready       VNET(ipfw_vnet_ready)
 106
 107 static VNET_DEFINE(int, fw_deny_unknown_exthdrs);
 108 #define V_fw_deny_unknown_exthdrs       VNET(fw_deny_unknown_exthdrs)
 109
 110 static VNET_DEFINE(int, fw_permit_single_frag6) = 1;
 111 #define V_fw_permit_single_frag6        VNET(fw_permit_single_frag6)
 112
 113 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
 114 static int default_to_accept = 1;
 115 #else
 116 static int default_to_accept;
 117 #endif
 118
 119 VNET_DEFINE(int, autoinc_step);
 120 VNET_DEFINE(int, fw_one_pass) = 1;
 121
 122 VNET_DEFINE(unsigned int, fw_tables_max);
 123 /* Use 128 tables by default */
 124 static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT;
 125
 126 /*
 127  * Each rule belongs to one of 32 different sets (0..31).
 128  * The variable set_disable contains one bit per set.
 129  * If the bit is set, all rules in the corresponding set
 130  * are disabled. Set RESVD_SET(31) is reserved for the default rule
 131  * and rules that are not deleted by the flush command,
 132  * and CANNOT be disabled.
 133  * Rules in set RESVD_SET can only be deleted individually.
 134  */
 135 VNET_DEFINE(u_int32_t, set_disable);
 136 #define V_set_disable                   VNET(set_disable)
 137
 138 VNET_DEFINE(int, fw_verbose);
 139 /* counter for ipfw_log(NULL...) */
 140 VNET_DEFINE(u_int64_t, norule_counter);
 141 VNET_DEFINE(int, verbose_limit);
 142
 143 /* layer3_chain contains the list of rules for layer 3 */
 144 VNET_DEFINE(struct ip_fw_chain, layer3_chain);
 145
 146 VNET_DEFINE(int, ipfw_nat_ready) = 0;
 147
 148 ipfw_nat_t *ipfw_nat_ptr = NULL;
 149 struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int);
 150 ipfw_nat_cfg_t *ipfw_nat_cfg_ptr;
 151 ipfw_nat_cfg_t *ipfw_nat_del_ptr;
 152 ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr;
 153 ipfw_nat_cfg_t *ipfw_nat_get_log_ptr;
 154
 155 #ifdef SYSCTL_NODE
 156 uint32_t dummy_def = IPFW_DEFAULT_RULE;
 157 static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS);
 158
 159 SYSBEGIN(f3)
 160
 161 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
 162 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, one_pass,
 163     CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0,
 164     "Only do a single pass through ipfw when using dummynet(4)");
 165 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step,
 166     CTLFLAG_RW, &VNET_NAME(autoinc_step), 0,
 167     "Rule number auto-increment step");
 168 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose,
 169     CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0,
 170     "Log matches to ipfw rules");
 171 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit,
 172     CTLFLAG_RW, &VNET_NAME(verbose_limit), 0,
 173     "Set upper limit of matches of ipfw rules logged");
 174 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD,
 175     &dummy_def, 0,
 176     "The default/max possible rule number.");
 177 SYSCTL_VNET_PROC(_net_inet_ip_fw, OID_AUTO, tables_max,
 178     CTLTYPE_UINT|CTLFLAG_RW, 0, 0, sysctl_ipfw_table_num, "IU",
 179     "Maximum number of tables");
 180 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN,
 181     &default_to_accept, 0,
 182     "Make the default rule accept all packets.");
 183 TUNABLE_INT("net.inet.ip.fw.default_to_accept", &default_to_accept);
 184 TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables);
 185 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, static_count,
 186     CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0,
 187     "Number of static rules");
 188
 189 #ifdef INET6
 190 SYSCTL_DECL(_net_inet6_ip6);
 191 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
 192 SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs,
 193     CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_deny_unknown_exthdrs), 0,
 194     "Deny packets with unknown IPv6 Extension Headers");
 195 SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6,
 196     CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_permit_single_frag6), 0,
 197     "Permit single packet IPv6 fragments");
 198 #endif /* INET6 */
 199
 200 SYSEND
 201
 202 #endif /* SYSCTL_NODE */
 203
 204
 205 /*
 206  * Some macros used in the various matching options.
 207  * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T
 208  * Other macros just cast void * into the appropriate type
 209  */
 210 #define L3HDR(T, ip)    ((T *)((u_int32_t *)(ip) + (ip)->ip_hl))
 211 #define TCP(p)          ((struct tcphdr *)(p))
 212 #define SCTP(p)         ((struct sctphdr *)(p))
 213 #define UDP(p)          ((struct udphdr *)(p))
 214 #define ICMP(p)         ((struct icmphdr *)(p))
 215 #define ICMP6(p)        ((struct icmp6_hdr *)(p))
 216
 217 static __inline int
 218 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd)
 219 {
 220         int type = icmp->icmp_type;
 221
 222         return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) );
 223 }
 224
 225 #define TT      ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \
 226     (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) )
 227
 228 static int
 229 is_icmp_query(struct icmphdr *icmp)
 230 {
 231         int type = icmp->icmp_type;
 232
 233         return (type <= ICMP_MAXTYPE && (TT & (1<<type)) );
 234 }
 235 #undef TT
 236
 237 /*
 238  * The following checks use two arrays of 8 or 16 bits to store the
 239  * bits that we want set or clear, respectively. They are in the
 240  * low and high half of cmd->arg1 or cmd->d[0].
 241  *
 242  * We scan options and store the bits we find set. We succeed if
 243  *
 244  *      (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear
 245  *
 246  * The code is sometimes optimized not to store additional variables.
 247  */
 248
 249 static int
 250 flags_match(ipfw_insn *cmd, u_int8_t bits)
 251 {
 252         u_char want_clear;
 253         bits = ~bits;
 254
 255         if ( ((cmd->arg1 & 0xff) & bits) != 0)
 256                 return 0; /* some bits we want set were clear */
 257         want_clear = (cmd->arg1 >> 8) & 0xff;
 258         if ( (want_clear & bits) != want_clear)
 259                 return 0; /* some bits we want clear were set */
 260         return 1;
 261 }
 262
 263 static int
 264 ipopts_match(struct ip *ip, ipfw_insn *cmd)
 265 {
 266         int optlen, bits = 0;
 267         u_char *cp = (u_char *)(ip + 1);
 268         int x = (ip->ip_hl << 2) - sizeof (struct ip);
 269
 270         for (; x > 0; x -= optlen, cp += optlen) {
 271                 int opt = cp[IPOPT_OPTVAL];
 272
 273                 if (opt == IPOPT_EOL)
 274                         break;
 275                 if (opt == IPOPT_NOP)
 276                         optlen = 1;
 277                 else {
 278                         optlen = cp[IPOPT_OLEN];
 279                         if (optlen <= 0 || optlen > x)
 280                                 return 0; /* invalid or truncated */
 281                 }
 282                 switch (opt) {
 283
 284                 default:
 285                         break;
 286
 287                 case IPOPT_LSRR:
 288                         bits |= IP_FW_IPOPT_LSRR;
 289                         break;
 290
 291                 case IPOPT_SSRR:
 292                         bits |= IP_FW_IPOPT_SSRR;
 293                         break;
 294
 295                 case IPOPT_RR:
 296                         bits |= IP_FW_IPOPT_RR;
 297                         break;
 298
 299                 case IPOPT_TS:
 300                         bits |= IP_FW_IPOPT_TS;
 301                         break;
 302                 }
 303         }
 304         return (flags_match(cmd, bits));
 305 }
 306
 307 static int
 308 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd)
 309 {
 310         int optlen, bits = 0;
 311         u_char *cp = (u_char *)(tcp + 1);
 312         int x = (tcp->th_off << 2) - sizeof(struct tcphdr);
 313
 314         for (; x > 0; x -= optlen, cp += optlen) {
 315                 int opt = cp[0];
 316                 if (opt == TCPOPT_EOL)
 317                         break;
 318                 if (opt == TCPOPT_NOP)
 319                         optlen = 1;
 320                 else {
 321                         optlen = cp[1];
 322                         if (optlen <= 0)
 323                                 break;
 324                 }
 325
 326                 switch (opt) {
 327
 328                 default:
 329                         break;
 330
 331                 case TCPOPT_MAXSEG:
 332                         bits |= IP_FW_TCPOPT_MSS;
 333                         break;
 334
 335                 case TCPOPT_WINDOW:
 336                         bits |= IP_FW_TCPOPT_WINDOW;
 337                         break;
 338
 339                 case TCPOPT_SACK_PERMITTED:
 340                 case TCPOPT_SACK:
 341                         bits |= IP_FW_TCPOPT_SACK;
 342                         break;
 343
 344                 case TCPOPT_TIMESTAMP:
 345                         bits |= IP_FW_TCPOPT_TS;
 346                         break;
 347
 348                 }
 349         }
 350         return (flags_match(cmd, bits));
 351 }
 352
 353 static int
 354 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain, uint32_t *tablearg)
 355 {
 356         if (ifp == NULL)        /* no iface with this packet, match fails */
 357                 return 0;
 358         /* Check by name or by IP address */
 359         if (cmd->name[0] != '\0') { /* match by name */
 360                 if (cmd->name[0] == '\1') /* use tablearg to match */
 361                         return ipfw_lookup_table_extended(chain, cmd->p.glob,
 362                                 ifp->if_xname, tablearg, IPFW_TABLE_INTERFACE);
 363                 /* Check name */
 364                 if (cmd->p.glob) {
 365                         if (fnmatch(cmd->name, ifp->if_xname, 0) == 0)
 366                                 return(1);
 367                 } else {
 368                         if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0)
 369                                 return(1);
 370                 }
 371         } else {
 372 #ifdef __FreeBSD__      /* and OSX too ? */
 373                 struct ifaddr *ia;
 374
 375                 if_addr_rlock(ifp);
 376                 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
 377                         if (ia->ifa_addr->sa_family != AF_INET)
 378                                 continue;
 379                         if (cmd->p.ip.s_addr == ((struct sockaddr_in *)
 380                             (ia->ifa_addr))->sin_addr.s_addr) {
 381                                 if_addr_runlock(ifp);
 382                                 return(1);      /* match */
 383                         }
 384                 }
 385                 if_addr_runlock(ifp);
 386 #endif /* __FreeBSD__ */
 387         }
 388         return(0);      /* no match, fail ... */
 389 }
 390
 391 /*
 392  * The verify_path function checks if a route to the src exists and
 393  * if it is reachable via ifp (when provided).
 394  *
 395  * The 'verrevpath' option checks that the interface that an IP packet
 396  * arrives on is the same interface that traffic destined for the
 397  * packet's source address would be routed out of.
 398  * The 'versrcreach' option just checks that the source address is
 399  * reachable via any route (except default) in the routing table.
 400  * These two are a measure to block forged packets. This is also
 401  * commonly known as "anti-spoofing" or Unicast Reverse Path
 402  * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs
 403  * is purposely reminiscent of the Cisco IOS command,
 404  *
 405  *   ip verify unicast reverse-path
 406  *   ip verify unicast source reachable-via any
 407  *
 408  * which implements the same functionality. But note that the syntax
 409  * is misleading, and the check may be performed on all IP packets
 410  * whether unicast, multicast, or broadcast.
 411  */
 412 static int
 413 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib)
 414 {
 415 #ifndef __FreeBSD__
 416         return 0;
 417 #else
 418         struct route ro;
 419         struct sockaddr_in *dst;
 420
 421         bzero(&ro, sizeof(ro));
 422
 423         dst = (struct sockaddr_in *)&(ro.ro_dst);
 424         dst->sin_family = AF_INET;
 425         dst->sin_len = sizeof(*dst);
 426         dst->sin_addr = src;
 427         in_rtalloc_ign(&ro, 0, fib);
 428
 429         if (ro.ro_rt == NULL)
 430                 return 0;
 431
 432         /*
 433          * If ifp is provided, check for equality with rtentry.
 434          * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
 435          * in order to pass packets injected back by if_simloop():
 436          * if useloopback == 1 routing entry (via lo0) for our own address
 437          * may exist, so we need to handle routing assymetry.
 438          */
 439         if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) {
 440                 RTFREE(ro.ro_rt);
 441                 return 0;
 442         }
 443
 444         /* if no ifp provided, check if rtentry is not default route */
 445         if (ifp == NULL &&
 446              satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) {
 447                 RTFREE(ro.ro_rt);
 448                 return 0;
 449         }
 450
 451         /* or if this is a blackhole/reject route */
 452         if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
 453                 RTFREE(ro.ro_rt);
 454                 return 0;
 455         }
 456
 457         /* found valid route */
 458         RTFREE(ro.ro_rt);
 459         return 1;
 460 #endif /* __FreeBSD__ */
 461 }
 462
 463 #ifdef INET6
 464 /*
 465  * ipv6 specific rules here...
 466  */
 467 static __inline int
 468 icmp6type_match (int type, ipfw_insn_u32 *cmd)
 469 {
 470         return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) );
 471 }
 472
 473 static int
 474 flow6id_match( int curr_flow, ipfw_insn_u32 *cmd )
 475 {
 476         int i;
 477         for (i=0; i <= cmd->o.arg1; ++i )
 478                 if (curr_flow == cmd->d[i] )
 479                         return 1;
 480         return 0;
 481 }
 482
 483 /* support for IP6_*_ME opcodes */
 484 static int
 485 search_ip6_addr_net (struct in6_addr * ip6_addr)
 486 {
 487         struct ifnet *mdc;
 488         struct ifaddr *mdc2;
 489         struct in6_ifaddr *fdm;
 490         struct in6_addr copia;
 491
 492         TAILQ_FOREACH(mdc, &V_ifnet, if_link) {
 493                 if_addr_rlock(mdc);
 494                 TAILQ_FOREACH(mdc2, &mdc->if_addrhead, ifa_link) {
 495                         if (mdc2->ifa_addr->sa_family == AF_INET6) {
 496                                 fdm = (struct in6_ifaddr *)mdc2;
 497                                 copia = fdm->ia_addr.sin6_addr;
 498                                 /* need for leaving scope_id in the sock_addr */
 499                                 in6_clearscope(&copia);
 500                                 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) {
 501                                         if_addr_runlock(mdc);
 502                                         return 1;
 503                                 }
 504                         }
 505                 }
 506                 if_addr_runlock(mdc);
 507         }
 508         return 0;
 509 }
 510
 511 static int
 512 verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib)
 513 {
 514         struct route_in6 ro;
 515         struct sockaddr_in6 *dst;
 516
 517         bzero(&ro, sizeof(ro));
 518
 519         dst = (struct sockaddr_in6 * )&(ro.ro_dst);
 520         dst->sin6_family = AF_INET6;
 521         dst->sin6_len = sizeof(*dst);
 522         dst->sin6_addr = *src;
 523
 524         in6_rtalloc_ign(&ro, 0, fib);
 525         if (ro.ro_rt == NULL)
 526                 return 0;
 527
 528         /*
 529          * if ifp is provided, check for equality with rtentry
 530          * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
 531          * to support the case of sending packets to an address of our own.
 532          * (where the former interface is the first argument of if_simloop()
 533          *  (=ifp), the latter is lo0)
 534          */
 535         if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) {
 536                 RTFREE(ro.ro_rt);
 537                 return 0;
 538         }
 539
 540         /* if no ifp provided, check if rtentry is not default route */
 541         if (ifp == NULL &&
 542             IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) {
 543                 RTFREE(ro.ro_rt);
 544                 return 0;
 545         }
 546
 547         /* or if this is a blackhole/reject route */
 548         if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
 549                 RTFREE(ro.ro_rt);
 550                 return 0;
 551         }
 552
 553         /* found valid route */
 554         RTFREE(ro.ro_rt);
 555         return 1;
 556
 557 }
 558
 559 static int
 560 is_icmp6_query(int icmp6_type)
 561 {
 562         if ((icmp6_type <= ICMP6_MAXTYPE) &&
 563             (icmp6_type == ICMP6_ECHO_REQUEST ||
 564             icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
 565             icmp6_type == ICMP6_WRUREQUEST ||
 566             icmp6_type == ICMP6_FQDN_QUERY ||
 567             icmp6_type == ICMP6_NI_QUERY))
 568                 return (1);
 569
 570         return (0);
 571 }
 572
 573 static void
 574 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6)
 575 {
 576         struct mbuf *m;
 577
 578         m = args->m;
 579         if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) {
 580                 struct tcphdr *tcp;
 581                 tcp = (struct tcphdr *)((char *)ip6 + hlen);
 582
 583                 if ((tcp->th_flags & TH_RST) == 0) {
 584                         struct mbuf *m0;
 585                         m0 = ipfw_send_pkt(args->m, &(args->f_id),
 586                             ntohl(tcp->th_seq), ntohl(tcp->th_ack),
 587                             tcp->th_flags | TH_RST);
 588                         if (m0 != NULL)
 589                                 ip6_output(m0, NULL, NULL, 0, NULL, NULL,
 590                                     NULL);
 591                 }
 592                 FREE_PKT(m);
 593         } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */
 594 #if 0
 595                 /*
 596                  * Unlike above, the mbufs need to line up with the ip6 hdr,
 597                  * as the contents are read. We need to m_adj() the
 598                  * needed amount.
 599                  * The mbuf will however be thrown away so we can adjust it.
 600                  * Remember we did an m_pullup on it already so we
 601                  * can make some assumptions about contiguousness.
 602                  */
 603                 if (args->L3offset)
 604                         m_adj(m, args->L3offset);
 605 #endif
 606                 icmp6_error(m, ICMP6_DST_UNREACH, code, 0);
 607         } else
 608                 FREE_PKT(m);
 609
 610         args->m = NULL;
 611 }
 612
 613 #endif /* INET6 */
 614
 615
 616 /*
 617  * sends a reject message, consuming the mbuf passed as an argument.
 618  */
 619 static void
 620 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip)
 621 {
 622
 623 #if 0
 624         /* XXX When ip is not guaranteed to be at mtod() we will
 625          * need to account for this */
 626          * The mbuf will however be thrown away so we can adjust it.
 627          * Remember we did an m_pullup on it already so we
 628          * can make some assumptions about contiguousness.
 629          */
 630         if (args->L3offset)
 631                 m_adj(m, args->L3offset);
 632 #endif
 633         if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */
 634                 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
 635         } else if (args->f_id.proto == IPPROTO_TCP) {
 636                 struct tcphdr *const tcp =
 637                     L3HDR(struct tcphdr, mtod(args->m, struct ip *));
 638                 if ( (tcp->th_flags & TH_RST) == 0) {
 639                         struct mbuf *m;
 640                         m = ipfw_send_pkt(args->m, &(args->f_id),
 641                                 ntohl(tcp->th_seq), ntohl(tcp->th_ack),
 642                                 tcp->th_flags | TH_RST);
 643                         if (m != NULL)
 644                                 ip_output(m, NULL, NULL, 0, NULL, NULL);
 645                 }
 646                 FREE_PKT(args->m);
 647         } else
 648                 FREE_PKT(args->m);
 649         args->m = NULL;
 650 }
 651
 652 /*
 653  * Support for uid/gid/jail lookup. These tests are expensive
 654  * (because we may need to look into the list of active sockets)
 655  * so we cache the results. ugid_lookupp is 0 if we have not
 656  * yet done a lookup, 1 if we succeeded, and -1 if we tried
 657  * and failed. The function always returns the match value.
 658  * We could actually spare the variable and use *uc, setting
 659  * it to '(void *)check_uidgid if we have no info, NULL if
 660  * we tried and failed, or any other value if successful.
 661  */
 662 static int
 663 check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp,
 664     struct ucred **uc)
 665 {
 666 #ifndef __FreeBSD__
 667         /* XXX */
 668         return cred_check(insn, proto, oif,
 669             dst_ip, dst_port, src_ip, src_port,
 670             (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb);
 671 #else  /* FreeBSD */
 672         struct in_addr src_ip, dst_ip;
 673         struct inpcbinfo *pi;
 674         struct ipfw_flow_id *id;
 675         struct inpcb *pcb, *inp;
 676         struct ifnet *oif;
 677         int lookupflags;
 678         int match;
 679
 680         id = &args->f_id;
 681         inp = args->inp;
 682         oif = args->oif;
 683
 684         /*
 685          * Check to see if the UDP or TCP stack supplied us with
 686          * the PCB. If so, rather then holding a lock and looking
 687          * up the PCB, we can use the one that was supplied.
 688          */
 689         if (inp && *ugid_lookupp == 0) {
 690                 INP_LOCK_ASSERT(inp);
 691                 if (inp->inp_socket != NULL) {
 692                         *uc = crhold(inp->inp_cred);
 693                         *ugid_lookupp = 1;
 694                 } else
 695                         *ugid_lookupp = -1;
 696         }
 697         /*
 698          * If we have already been here and the packet has no
 699          * PCB entry associated with it, then we can safely
 700          * assume that this is a no match.
 701          */
 702         if (*ugid_lookupp == -1)
 703                 return (0);
 704         if (id->proto == IPPROTO_TCP) {
 705                 lookupflags = 0;
 706                 pi = &V_tcbinfo;
 707         } else if (id->proto == IPPROTO_UDP) {
 708                 lookupflags = INPLOOKUP_WILDCARD;
 709                 pi = &V_udbinfo;
 710         } else
 711                 return 0;
 712         lookupflags |= INPLOOKUP_RLOCKPCB;
 713         match = 0;
 714         if (*ugid_lookupp == 0) {
 715                 if (id->addr_type == 6) {
 716 #ifdef INET6
 717                         if (oif == NULL)
 718                                 pcb = in6_pcblookup_mbuf(pi,
 719                                     &id->src_ip6, htons(id->src_port),
 720                                     &id->dst_ip6, htons(id->dst_port),
 721                                     lookupflags, oif, args->m);
 722                         else
 723                                 pcb = in6_pcblookup_mbuf(pi,
 724                                     &id->dst_ip6, htons(id->dst_port),
 725                                     &id->src_ip6, htons(id->src_port),
 726                                     lookupflags, oif, args->m);
 727 #else
 728                         *ugid_lookupp = -1;
 729                         return (0);
 730 #endif
 731                 } else {
 732                         src_ip.s_addr = htonl(id->src_ip);
 733                         dst_ip.s_addr = htonl(id->dst_ip);
 734                         if (oif == NULL)
 735                                 pcb = in_pcblookup_mbuf(pi,
 736                                     src_ip, htons(id->src_port),
 737                                     dst_ip, htons(id->dst_port),
 738                                     lookupflags, oif, args->m);
 739                         else
 740                                 pcb = in_pcblookup_mbuf(pi,
 741                                     dst_ip, htons(id->dst_port),
 742                                     src_ip, htons(id->src_port),
 743                                     lookupflags, oif, args->m);
 744                 }
 745                 if (pcb != NULL) {
 746                         INP_RLOCK_ASSERT(pcb);
 747                         *uc = crhold(pcb->inp_cred);
 748                         *ugid_lookupp = 1;
 749                         INP_RUNLOCK(pcb);
 750                 }
 751                 if (*ugid_lookupp == 0) {
 752                         /*
 753                          * We tried and failed, set the variable to -1
 754                          * so we will not try again on this packet.
 755                          */
 756                         *ugid_lookupp = -1;
 757                         return (0);
 758                 }
 759         }
 760         if (insn->o.opcode == O_UID)
 761                 match = ((*uc)->cr_uid == (uid_t)insn->d[0]);
 762         else if (insn->o.opcode == O_GID)
 763                 match = groupmember((gid_t)insn->d[0], *uc);
 764         else if (insn->o.opcode == O_JAIL)
 765                 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]);
 766         return (match);
 767 #endif /* __FreeBSD__ */
 768 }
 769
 770 /*
 771  * Helper function to set args with info on the rule after the matching
 772  * one. slot is precise, whereas we guess rule_id as they are
 773  * assigned sequentially.
 774  */
 775 static inline void
 776 set_match(struct ip_fw_args *args, int slot,
 777         struct ip_fw_chain *chain)
 778 {
 779         args->rule.chain_id = chain->id;
 780         args->rule.slot = slot + 1; /* we use 0 as a marker */
 781         args->rule.rule_id = 1 + chain->map[slot]->id;
 782         args->rule.rulenum = chain->map[slot]->rulenum;
 783 }
 784
 785 /*
 786  * Helper function to enable cached rule lookups using
 787  * x_next and next_rule fields in ipfw rule.
 788  */
 789 static int
 790 jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num,
 791     int tablearg, int jump_backwards)
 792 {
 793         int f_pos;
 794
 795         /* If possible use cached f_pos (in f->next_rule),
 796          * whose version is written in f->next_rule
 797          * (horrible hacks to avoid changing the ABI).
 798          */
 799         if (num != IP_FW_TABLEARG && (uintptr_t)f->x_next == chain->id)
 800                 f_pos = (uintptr_t)f->next_rule;
 801         else {
 802                 int i = IP_FW_ARG_TABLEARG(num);
 803                 /* make sure we do not jump backward */
 804                 if (jump_backwards == 0 && i <= f->rulenum)
 805                         i = f->rulenum + 1;
 806                 f_pos = ipfw_find_rule(chain, i, 0);
 807                 /* update the cache */
 808                 if (num != IP_FW_TABLEARG) {
 809                         f->next_rule = (void *)(uintptr_t)f_pos;
 810                         f->x_next = (void *)(uintptr_t)chain->id;
 811                 }
 812         }
 813
 814         return (f_pos);
 815 }
 816
 817 /*
 818  * The main check routine for the firewall.
 819  *
 820  * All arguments are in args so we can modify them and return them
 821  * back to the caller.
 822  *
 823  * Parameters:
 824  *
 825  *      args->m (in/out) The packet; we set to NULL when/if we nuke it.
 826  *              Starts with the IP header.
 827  *      args->eh (in)   Mac header if present, NULL for layer3 packet.
 828  *      args->L3offset  Number of bytes bypassed if we came from L2.
 829  *                      e.g. often sizeof(eh)  ** NOTYET **
 830  *      args->oif       Outgoing interface, NULL if packet is incoming.
 831  *              The incoming interface is in the mbuf. (in)
 832  *      args->divert_rule (in/out)
 833  *              Skip up to the first rule past this rule number;
 834  *              upon return, non-zero port number for divert or tee.
 835  *
 836  *      args->rule      Pointer to the last matching rule (in/out)
 837  *      args->next_hop  Socket we are forwarding to (out).
 838  *      args->next_hop6 IPv6 next hop we are forwarding to (out).
 839  *      args->f_id      Addresses grabbed from the packet (out)
 840  *      args->rule.info a cookie depending on rule action
 841  *
 842  * Return value:
 843  *
 844  *      IP_FW_PASS      the packet must be accepted
 845  *      IP_FW_DENY      the packet must be dropped
 846  *      IP_FW_DIVERT    divert packet, port in m_tag
 847  *      IP_FW_TEE       tee packet, port in m_tag
 848  *      IP_FW_DUMMYNET  to dummynet, pipe in args->cookie
 849  *      IP_FW_NETGRAPH  into netgraph, cookie args->cookie
 850  *              args->rule contains the matching rule,
 851  *              args->rule.info has additional information.
 852  *
 853  */
 854 int
 855 ipfw_chk(struct ip_fw_args *args)
 856 {
 857
 858         /*
 859          * Local variables holding state while processing a packet:
 860          *
 861          * IMPORTANT NOTE: to speed up the processing of rules, there
 862          * are some assumption on the values of the variables, which
 863          * are documented here. Should you change them, please check
 864          * the implementation of the various instructions to make sure
 865          * that they still work.
 866          *
 867          * args->eh     The MAC header. It is non-null for a layer2
 868          *      packet, it is NULL for a layer-3 packet.
 869          * **notyet**
 870          * args->L3offset Offset in the packet to the L3 (IP or equiv.) header.
 871          *
 872          * m | args->m  Pointer to the mbuf, as received from the caller.
 873          *      It may change if ipfw_chk() does an m_pullup, or if it
 874          *      consumes the packet because it calls send_reject().
 875          *      XXX This has to change, so that ipfw_chk() never modifies
 876          *      or consumes the buffer.
 877          * ip   is the beginning of the ip(4 or 6) header.
 878          *      Calculated by adding the L3offset to the start of data.
 879          *      (Until we start using L3offset, the packet is
 880          *      supposed to start with the ip header).
 881          */
 882         struct mbuf *m = args->m;
 883         struct ip *ip = mtod(m, struct ip *);
 884
 885         /*
 886          * For rules which contain uid/gid or jail constraints, cache
 887          * a copy of the users credentials after the pcb lookup has been
 888          * executed. This will speed up the processing of rules with
 889          * these types of constraints, as well as decrease contention
 890          * on pcb related locks.
 891          */
 892 #ifndef __FreeBSD__
 893         struct bsd_ucred ucred_cache;
 894 #else
 895         struct ucred *ucred_cache = NULL;
 896 #endif
 897         int ucred_lookup = 0;
 898
 899         /*
 900          * oif | args->oif      If NULL, ipfw_chk has been called on the
 901          *      inbound path (ether_input, ip_input).
 902          *      If non-NULL, ipfw_chk has been called on the outbound path
 903          *      (ether_output, ip_output).
 904          */
 905         struct ifnet *oif = args->oif;
 906
 907         int f_pos = 0;          /* index of current rule in the array */
 908         int retval = 0;
 909
 910         /*
 911          * hlen The length of the IP header.
 912          */
 913         u_int hlen = 0;         /* hlen >0 means we have an IP pkt */
 914
 915         /*
 916          * offset       The offset of a fragment. offset != 0 means that
 917          *      we have a fragment at this offset of an IPv4 packet.
 918          *      offset == 0 means that (if this is an IPv4 packet)
 919          *      this is the first or only fragment.
 920          *      For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header
 921          *      or there is a single packet fragement (fragement header added
 922          *      without needed).  We will treat a single packet fragment as if
 923          *      there was no fragment header (or log/block depending on the
 924          *      V_fw_permit_single_frag6 sysctl setting).
 925          */
 926         u_short offset = 0;
 927         u_short ip6f_mf = 0;
 928
 929         /*
 930          * Local copies of addresses. They are only valid if we have
 931          * an IP packet.
 932          *
 933          * proto        The protocol. Set to 0 for non-ip packets,
 934          *      or to the protocol read from the packet otherwise.
 935          *      proto != 0 means that we have an IPv4 packet.
 936          *
 937          * src_port, dst_port   port numbers, in HOST format. Only
 938          *      valid for TCP and UDP packets.
 939          *
 940          * src_ip, dst_ip       ip addresses, in NETWORK format.
 941          *      Only valid for IPv4 packets.
 942          */
 943         uint8_t proto;
 944         uint16_t src_port = 0, dst_port = 0;    /* NOTE: host format    */
 945         struct in_addr src_ip, dst_ip;          /* NOTE: network format */
 946         uint16_t iplen=0;
 947         int pktlen;
 948         uint16_t        etype = 0;      /* Host order stored ether type */
 949
 950         /*
 951          * dyn_dir = MATCH_UNKNOWN when rules unchecked,
 952          *      MATCH_NONE when checked and not matched (q = NULL),
 953          *      MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL)
 954          */
 955         int dyn_dir = MATCH_UNKNOWN;
 956         ipfw_dyn_rule *q = NULL;
 957         struct ip_fw_chain *chain = &V_layer3_chain;
 958
 959         /*
 960          * We store in ulp a pointer to the upper layer protocol header.
 961          * In the ipv4 case this is easy to determine from the header,
 962          * but for ipv6 we might have some additional headers in the middle.
 963          * ulp is NULL if not found.
 964          */
 965         void *ulp = NULL;               /* upper layer protocol pointer. */
 966
 967         /* XXX ipv6 variables */
 968         int is_ipv6 = 0;
 969         uint8_t icmp6_type = 0;
 970         uint16_t ext_hd = 0;    /* bits vector for extension header filtering */
 971         /* end of ipv6 variables */
 972
 973         int is_ipv4 = 0;
 974
 975         int done = 0;           /* flag to exit the outer loop */
 976
 977         if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready))
 978                 return (IP_FW_PASS);    /* accept */
 979
 980         dst_ip.s_addr = 0;              /* make sure it is initialized */
 981         src_ip.s_addr = 0;              /* make sure it is initialized */
 982         pktlen = m->m_pkthdr.len;
 983         args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */
 984         proto = args->f_id.proto = 0;   /* mark f_id invalid */
 985                 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */
 986
 987 /*
 988  * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous,
 989  * then it sets p to point at the offset "len" in the mbuf. WARNING: the
 990  * pointer might become stale after other pullups (but we never use it
 991  * this way).
 992  */
 993 #define PULLUP_TO(_len, p, T)   PULLUP_LEN(_len, p, sizeof(T))
 994 #define PULLUP_LEN(_len, p, T)                                  \
 995 do {                                                            \
 996         int x = (_len) + T;                                     \
 997         if ((m)->m_len < x) {                                   \
 998                 args->m = m = m_pullup(m, x);                   \
 999                 if (m == NULL)                                  \
1000                         goto pullup_failed;                     \
1001         }                                                       \
1002         p = (mtod(m, char *) + (_len));                         \
1003 } while (0)
1004
1005         /*
1006          * if we have an ether header,
1007          */
1008         if (args->eh)
1009                 etype = ntohs(args->eh->ether_type);
1010
1011         /* Identify IP packets and fill up variables. */
1012         if (pktlen >= sizeof(struct ip6_hdr) &&
1013             (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) {
1014                 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip;
1015                 is_ipv6 = 1;
1016                 args->f_id.addr_type = 6;
1017                 hlen = sizeof(struct ip6_hdr);
1018                 proto = ip6->ip6_nxt;
1019
1020                 /* Search extension headers to find upper layer protocols */
1021                 while (ulp == NULL && offset == 0) {
1022                         switch (proto) {
1023                         case IPPROTO_ICMPV6:
1024                                 PULLUP_TO(hlen, ulp, struct icmp6_hdr);
1025                                 icmp6_type = ICMP6(ulp)->icmp6_type;
1026                                 break;
1027
1028                         case IPPROTO_TCP:
1029                                 PULLUP_TO(hlen, ulp, struct tcphdr);
1030                                 dst_port = TCP(ulp)->th_dport;
1031                                 src_port = TCP(ulp)->th_sport;
1032                                 /* save flags for dynamic rules */
1033                                 args->f_id._flags = TCP(ulp)->th_flags;
1034                                 break;
1035
1036                         case IPPROTO_SCTP:
1037                                 PULLUP_TO(hlen, ulp, struct sctphdr);
1038                                 src_port = SCTP(ulp)->src_port;
1039                                 dst_port = SCTP(ulp)->dest_port;
1040                                 break;
1041
1042                         case IPPROTO_UDP:
1043                                 PULLUP_TO(hlen, ulp, struct udphdr);
1044                                 dst_port = UDP(ulp)->uh_dport;
1045                                 src_port = UDP(ulp)->uh_sport;
1046                                 break;
1047
1048                         case IPPROTO_HOPOPTS:   /* RFC 2460 */
1049                                 PULLUP_TO(hlen, ulp, struct ip6_hbh);
1050                                 ext_hd |= EXT_HOPOPTS;
1051                                 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
1052                                 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
1053                                 ulp = NULL;
1054                                 break;
1055
1056                         case IPPROTO_ROUTING:   /* RFC 2460 */
1057                                 PULLUP_TO(hlen, ulp, struct ip6_rthdr);
1058                                 switch (((struct ip6_rthdr *)ulp)->ip6r_type) {
1059                                 case 0:
1060                                         ext_hd |= EXT_RTHDR0;
1061                                         break;
1062                                 case 2:
1063                                         ext_hd |= EXT_RTHDR2;
1064                                         break;
1065                                 default:
1066                                         if (V_fw_verbose)
1067                                                 printf("IPFW2: IPV6 - Unknown "
1068                                                     "Routing Header type(%d)\n",
1069                                                     ((struct ip6_rthdr *)
1070                                                     ulp)->ip6r_type);
1071                                         if (V_fw_deny_unknown_exthdrs)
1072                                             return (IP_FW_DENY);
1073                                         break;
1074                                 }
1075                                 ext_hd |= EXT_ROUTING;
1076                                 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3;
1077                                 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt;
1078                                 ulp = NULL;
1079                                 break;
1080
1081                         case IPPROTO_FRAGMENT:  /* RFC 2460 */
1082                                 PULLUP_TO(hlen, ulp, struct ip6_frag);
1083                                 ext_hd |= EXT_FRAGMENT;
1084                                 hlen += sizeof (struct ip6_frag);
1085                                 proto = ((struct ip6_frag *)ulp)->ip6f_nxt;
1086                                 offset = ((struct ip6_frag *)ulp)->ip6f_offlg &
1087                                         IP6F_OFF_MASK;
1088                                 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg &
1089                                         IP6F_MORE_FRAG;
1090                                 if (V_fw_permit_single_frag6 == 0 &&
1091                                     offset == 0 && ip6f_mf == 0) {
1092                                         if (V_fw_verbose)
1093                                                 printf("IPFW2: IPV6 - Invalid "
1094                                                     "Fragment Header\n");
1095                                         if (V_fw_deny_unknown_exthdrs)
1096                                             return (IP_FW_DENY);
1097                                         break;
1098                                 }
1099                                 args->f_id.extra =
1100                                     ntohl(((struct ip6_frag *)ulp)->ip6f_ident);
1101                                 ulp = NULL;
1102                                 break;
1103
1104                         case IPPROTO_DSTOPTS:   /* RFC 2460 */
1105                                 PULLUP_TO(hlen, ulp, struct ip6_hbh);
1106                                 ext_hd |= EXT_DSTOPTS;
1107                                 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
1108                                 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
1109                                 ulp = NULL;
1110                                 break;
1111
1112                         case IPPROTO_AH:        /* RFC 2402 */
1113                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
1114                                 ext_hd |= EXT_AH;
1115                                 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2;
1116                                 proto = ((struct ip6_ext *)ulp)->ip6e_nxt;
1117                                 ulp = NULL;
1118                                 break;
1119
1120                         case IPPROTO_ESP:       /* RFC 2406 */
1121                                 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */
1122                                 /* Anything past Seq# is variable length and
1123                                  * data past this ext. header is encrypted. */
1124                                 ext_hd |= EXT_ESP;
1125                                 break;
1126
1127                         case IPPROTO_NONE:      /* RFC 2460 */
1128                                 /*
1129                                  * Packet ends here, and IPv6 header has
1130                                  * already been pulled up. If ip6e_len!=0
1131                                  * then octets must be ignored.
1132                                  */
1133                                 ulp = ip; /* non-NULL to get out of loop. */
1134                                 break;
1135
1136                         case IPPROTO_OSPFIGP:
1137                                 /* XXX OSPF header check? */
1138                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
1139                                 break;
1140
1141                         case IPPROTO_PIM:
1142                                 /* XXX PIM header check? */
1143                                 PULLUP_TO(hlen, ulp, struct pim);
1144                                 break;
1145
1146                         case IPPROTO_CARP:
1147                                 PULLUP_TO(hlen, ulp, struct carp_header);
1148                                 if (((struct carp_header *)ulp)->carp_version !=
1149                                     CARP_VERSION)
1150                                         return (IP_FW_DENY);
1151                                 if (((struct carp_header *)ulp)->carp_type !=
1152                                     CARP_ADVERTISEMENT)
1153                                         return (IP_FW_DENY);
1154                                 break;
1155
1156                         case IPPROTO_IPV6:      /* RFC 2893 */
1157                                 PULLUP_TO(hlen, ulp, struct ip6_hdr);
1158                                 break;
1159
1160                         case IPPROTO_IPV4:      /* RFC 2893 */
1161                                 PULLUP_TO(hlen, ulp, struct ip);
1162                                 break;
1163
1164                         default:
1165                                 if (V_fw_verbose)
1166                                         printf("IPFW2: IPV6 - Unknown "
1167                                             "Extension Header(%d), ext_hd=%x\n",
1168                                              proto, ext_hd);
1169                                 if (V_fw_deny_unknown_exthdrs)
1170                                     return (IP_FW_DENY);
1171                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
1172                                 break;
1173                         } /*switch */
1174                 }
1175                 ip = mtod(m, struct ip *);
1176                 ip6 = (struct ip6_hdr *)ip;
1177                 args->f_id.src_ip6 = ip6->ip6_src;
1178                 args->f_id.dst_ip6 = ip6->ip6_dst;
1179                 args->f_id.src_ip = 0;
1180                 args->f_id.dst_ip = 0;
1181                 args->f_id.flow_id6 = ntohl(ip6->ip6_flow);
1182         } else if (pktlen >= sizeof(struct ip) &&
1183             (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) {
1184                 is_ipv4 = 1;
1185                 hlen = ip->ip_hl << 2;
1186                 args->f_id.addr_type = 4;
1187
1188                 /*
1189                  * Collect parameters into local variables for faster matching.
1190                  */
1191                 proto = ip->ip_p;
1192                 src_ip = ip->ip_src;
1193                 dst_ip = ip->ip_dst;
1194                 offset = ntohs(ip->ip_off) & IP_OFFMASK;
1195                 iplen = ntohs(ip->ip_len);
1196                 pktlen = iplen < pktlen ? iplen : pktlen;
1197
1198                 if (offset == 0) {
1199                         switch (proto) {
1200                         case IPPROTO_TCP:
1201                                 PULLUP_TO(hlen, ulp, struct tcphdr);
1202                                 dst_port = TCP(ulp)->th_dport;
1203                                 src_port = TCP(ulp)->th_sport;
1204                                 /* save flags for dynamic rules */
1205                                 args->f_id._flags = TCP(ulp)->th_flags;
1206                                 break;
1207
1208                         case IPPROTO_SCTP:
1209                                 PULLUP_TO(hlen, ulp, struct sctphdr);
1210                                 src_port = SCTP(ulp)->src_port;
1211                                 dst_port = SCTP(ulp)->dest_port;
1212                                 break;
1213
1214                         case IPPROTO_UDP:
1215                                 PULLUP_TO(hlen, ulp, struct udphdr);
1216                                 dst_port = UDP(ulp)->uh_dport;
1217                                 src_port = UDP(ulp)->uh_sport;
1218                                 break;
1219
1220                         case IPPROTO_ICMP:
1221                                 PULLUP_TO(hlen, ulp, struct icmphdr);
1222                                 //args->f_id.flags = ICMP(ulp)->icmp_type;
1223                                 break;
1224
1225                         default:
1226                                 break;
1227                         }
1228                 }
1229
1230                 ip = mtod(m, struct ip *);
1231                 args->f_id.src_ip = ntohl(src_ip.s_addr);
1232                 args->f_id.dst_ip = ntohl(dst_ip.s_addr);
1233         }
1234 #undef PULLUP_TO
1235         if (proto) { /* we may have port numbers, store them */
1236                 args->f_id.proto = proto;
1237                 args->f_id.src_port = src_port = ntohs(src_port);
1238                 args->f_id.dst_port = dst_port = ntohs(dst_port);
1239         }
1240
1241         IPFW_PF_RLOCK(chain);
1242         if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */
1243                 IPFW_PF_RUNLOCK(chain);
1244                 return (IP_FW_PASS);    /* accept */
1245         }
1246         if (args->rule.slot) {
1247                 /*
1248                  * Packet has already been tagged as a result of a previous
1249                  * match on rule args->rule aka args->rule_id (PIPE, QUEUE,
1250                  * REASS, NETGRAPH, DIVERT/TEE...)
1251                  * Validate the slot and continue from the next one
1252                  * if still present, otherwise do a lookup.
1253                  */
1254                 f_pos = (args->rule.chain_id == chain->id) ?
1255                     args->rule.slot :
1256                     ipfw_find_rule(chain, args->rule.rulenum,
1257                         args->rule.rule_id);
1258         } else {
1259                 f_pos = 0;
1260         }
1261
1262         /*
1263          * Now scan the rules, and parse microinstructions for each rule.
1264          * We have two nested loops and an inner switch. Sometimes we
1265          * need to break out of one or both loops, or re-enter one of
1266          * the loops with updated variables. Loop variables are:
1267          *
1268          *      f_pos (outer loop) points to the current rule.
1269          *              On output it points to the matching rule.
1270          *      done (outer loop) is used as a flag to break the loop.
1271          *      l (inner loop)  residual length of current rule.
1272          *              cmd points to the current microinstruction.
1273          *
1274          * We break the inner loop by setting l=0 and possibly
1275          * cmdlen=0 if we don't want to advance cmd.
1276          * We break the outer loop by setting done=1
1277          * We can restart the inner loop by setting l>0 and f_pos, f, cmd
1278          * as needed.
1279          */
1280         for (; f_pos < chain->n_rules; f_pos++) {
1281                 ipfw_insn *cmd;
1282                 uint32_t tablearg = 0;
1283                 int l, cmdlen, skip_or; /* skip rest of OR block */
1284                 struct ip_fw *f;
1285
1286                 f = chain->map[f_pos];
1287                 if (V_set_disable & (1 << f->set) )
1288                         continue;
1289
1290                 skip_or = 0;
1291                 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ;
1292                     l -= cmdlen, cmd += cmdlen) {
1293                         int match;
1294
1295                         /*
1296                          * check_body is a jump target used when we find a
1297                          * CHECK_STATE, and need to jump to the body of
1298                          * the target rule.
1299                          */
1300
1301 /* check_body: */
1302                         cmdlen = F_LEN(cmd);
1303                         /*
1304                          * An OR block (insn_1 || .. || insn_n) has the
1305                          * F_OR bit set in all but the last instruction.
1306                          * The first match will set "skip_or", and cause
1307                          * the following instructions to be skipped until
1308                          * past the one with the F_OR bit clear.
1309                          */
1310                         if (skip_or) {          /* skip this instruction */
1311                                 if ((cmd->len & F_OR) == 0)
1312                                         skip_or = 0;    /* next one is good */
1313                                 continue;
1314                         }
1315                         match = 0; /* set to 1 if we succeed */
1316
1317                         switch (cmd->opcode) {
1318                         /*
1319                          * The first set of opcodes compares the packet's
1320                          * fields with some pattern, setting 'match' if a
1321                          * match is found. At the end of the loop there is
1322                          * logic to deal with F_NOT and F_OR flags associated
1323                          * with the opcode.
1324                          */
1325                         case O_NOP:
1326                                 match = 1;
1327                                 break;
1328
1329                         case O_FORWARD_MAC:
1330                                 printf("ipfw: opcode %d unimplemented\n",
1331                                     cmd->opcode);
1332                                 break;
1333
1334                         case O_GID:
1335                         case O_UID:
1336                         case O_JAIL:
1337                                 /*
1338                                  * We only check offset == 0 && proto != 0,
1339                                  * as this ensures that we have a
1340                                  * packet with the ports info.
1341                                  */
1342                                 if (offset != 0)
1343                                         break;
1344                                 if (proto == IPPROTO_TCP ||
1345                                     proto == IPPROTO_UDP)
1346                                         match = check_uidgid(
1347                                                     (ipfw_insn_u32 *)cmd,
1348                                                     args, &ucred_lookup,
1349 #ifdef __FreeBSD__
1350                                                     &ucred_cache);
1351 #else
1352                                                     (void *)&ucred_cache);
1353 #endif
1354                                 break;
1355
1356                         case O_RECV:
1357                                 match = iface_match(m->m_pkthdr.rcvif,
1358                                     (ipfw_insn_if *)cmd, chain, &tablearg);
1359                                 break;
1360
1361                         case O_XMIT:
1362                                 match = iface_match(oif, (ipfw_insn_if *)cmd,
1363                                     chain, &tablearg);
1364                                 break;
1365
1366                         case O_VIA:
1367                                 match = iface_match(oif ? oif :
1368                                     m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd,
1369                                     chain, &tablearg);
1370                                 break;
1371
1372                         case O_MACADDR2:
1373                                 if (args->eh != NULL) { /* have MAC header */
1374                                         u_int32_t *want = (u_int32_t *)
1375                                                 ((ipfw_insn_mac *)cmd)->addr;
1376                                         u_int32_t *mask = (u_int32_t *)
1377                                                 ((ipfw_insn_mac *)cmd)->mask;
1378                                         u_int32_t *hdr = (u_int32_t *)args->eh;
1379
1380                                         match =
1381                                             ( want[0] == (hdr[0] & mask[0]) &&
1382                                               want[1] == (hdr[1] & mask[1]) &&
1383                                               want[2] == (hdr[2] & mask[2]) );
1384                                 }
1385                                 break;
1386
1387                         case O_MAC_TYPE:
1388                                 if (args->eh != NULL) {
1389                                         u_int16_t *p =
1390                                             ((ipfw_insn_u16 *)cmd)->ports;
1391                                         int i;
1392
1393                                         for (i = cmdlen - 1; !match && i>0;
1394                                             i--, p += 2)
1395                                                 match = (etype >= p[0] &&
1396                                                     etype <= p[1]);
1397                                 }
1398                                 break;
1399
1400                         case O_FRAG:
1401                                 match = (offset != 0);
1402                                 break;
1403
1404                         case O_IN:      /* "out" is "not in" */
1405                                 match = (oif == NULL);
1406                                 break;
1407
1408                         case O_LAYER2:
1409                                 match = (args->eh != NULL);
1410                                 break;
1411
1412                         case O_DIVERTED:
1413                             {
1414                                 /* For diverted packets, args->rule.info
1415                                  * contains the divert port (in host format)
1416                                  * reason and direction.
1417                                  */
1418                                 uint32_t i = args->rule.info;
1419                                 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT &&
1420                                     cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2);
1421                             }
1422                                 break;
1423
1424                         case O_PROTO:
1425                                 /*
1426                                  * We do not allow an arg of 0 so the
1427                                  * check of "proto" only suffices.
1428                                  */
1429                                 match = (proto == cmd->arg1);
1430                                 break;
1431
1432                         case O_IP_SRC:
1433                                 match = is_ipv4 &&
1434                                     (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1435                                     src_ip.s_addr);
1436                                 break;
1437
1438                         case O_IP_SRC_LOOKUP:
1439                         case O_IP_DST_LOOKUP:
1440                                 if (is_ipv4) {
1441                                     uint32_t key =
1442                                         (cmd->opcode == O_IP_DST_LOOKUP) ?
1443                                             dst_ip.s_addr : src_ip.s_addr;
1444                                     uint32_t v = 0;
1445
1446                                     if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) {
1447                                         /* generic lookup. The key must be
1448                                          * in 32bit big-endian format.
1449                                          */
1450                                         v = ((ipfw_insn_u32 *)cmd)->d[1];
1451                                         if (v == 0)
1452                                             key = dst_ip.s_addr;
1453                                         else if (v == 1)
1454                                             key = src_ip.s_addr;
1455                                         else if (v == 6) /* dscp */
1456                                             key = (ip->ip_tos >> 2) & 0x3f;
1457                                         else if (offset != 0)
1458                                             break;
1459                                         else if (proto != IPPROTO_TCP &&
1460                                                 proto != IPPROTO_UDP)
1461                                             break;
1462                                         else if (v == 2)
1463                                             key = htonl(dst_port);
1464                                         else if (v == 3)
1465                                             key = htonl(src_port);
1466                                         else if (v == 4 || v == 5) {
1467                                             check_uidgid(
1468                                                 (ipfw_insn_u32 *)cmd,
1469                                                 args, &ucred_lookup,
1470 #ifdef __FreeBSD__
1471                                                 &ucred_cache);
1472                                             if (v == 4 /* O_UID */)
1473                                                 key = ucred_cache->cr_uid;
1474                                             else if (v == 5 /* O_JAIL */)
1475                                                 key = ucred_cache->cr_prison->pr_id;
1476 #else /* !__FreeBSD__ */
1477                                                 (void *)&ucred_cache);
1478                                             if (v ==4 /* O_UID */)
1479                                                 key = ucred_cache.uid;
1480                                             else if (v == 5 /* O_JAIL */)
1481                                                 key = ucred_cache.xid;
1482 #endif /* !__FreeBSD__ */
1483                                             key = htonl(key);
1484                                         } else
1485                                             break;
1486                                     }
1487                                     match = ipfw_lookup_table(chain,
1488                                         cmd->arg1, key, &v);
1489                                     if (!match)
1490                                         break;
1491                                     if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
1492                                         match =
1493                                             ((ipfw_insn_u32 *)cmd)->d[0] == v;
1494                                     else
1495                                         tablearg = v;
1496                                 } else if (is_ipv6) {
1497                                         uint32_t v = 0;
1498                                         void *pkey = (cmd->opcode == O_IP_DST_LOOKUP) ?
1499                                                 &args->f_id.dst_ip6: &args->f_id.src_ip6;
1500                                         match = ipfw_lookup_table_extended(chain,
1501                                                         cmd->arg1, pkey, &v,
1502                                                         IPFW_TABLE_CIDR);
1503                                         if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
1504                                                 match = ((ipfw_insn_u32 *)cmd)->d[0] == v;
1505                                         if (match)
1506                                                 tablearg = v;
1507                                 }
1508                                 break;
1509
1510                         case O_IP_SRC_MASK:
1511                         case O_IP_DST_MASK:
1512                                 if (is_ipv4) {
1513                                     uint32_t a =
1514                                         (cmd->opcode == O_IP_DST_MASK) ?
1515                                             dst_ip.s_addr : src_ip.s_addr;
1516                                     uint32_t *p = ((ipfw_insn_u32 *)cmd)->d;
1517                                     int i = cmdlen-1;
1518
1519                                     for (; !match && i>0; i-= 2, p+= 2)
1520                                         match = (p[0] == (a & p[1]));
1521                                 }
1522                                 break;
1523
1524                         case O_IP_SRC_ME:
1525                                 if (is_ipv4) {
1526                                         struct ifnet *tif;
1527
1528                                         INADDR_TO_IFP(src_ip, tif);
1529                                         match = (tif != NULL);
1530                                         break;
1531                                 }
1532 #ifdef INET6
1533                                 /* FALLTHROUGH */
1534                         case O_IP6_SRC_ME:
1535                                 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6);
1536 #endif
1537                                 break;
1538
1539                         case O_IP_DST_SET:
1540                         case O_IP_SRC_SET:
1541                                 if (is_ipv4) {
1542                                         u_int32_t *d = (u_int32_t *)(cmd+1);
1543                                         u_int32_t addr =
1544                                             cmd->opcode == O_IP_DST_SET ?
1545                                                 args->f_id.dst_ip :
1546                                                 args->f_id.src_ip;
1547
1548                                             if (addr < d[0])
1549                                                     break;
1550                                             addr -= d[0]; /* subtract base */
1551                                             match = (addr < cmd->arg1) &&
1552                                                 ( d[ 1 + (addr>>5)] &
1553                                                   (1<<(addr & 0x1f)) );
1554                                 }
1555                                 break;
1556
1557                         case O_IP_DST:
1558                                 match = is_ipv4 &&
1559                                     (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1560                                     dst_ip.s_addr);
1561                                 break;
1562
1563                         case O_IP_DST_ME:
1564                                 if (is_ipv4) {
1565                                         struct ifnet *tif;
1566
1567                                         INADDR_TO_IFP(dst_ip, tif);
1568                                         match = (tif != NULL);
1569                                         break;
1570                                 }
1571 #ifdef INET6
1572                                 /* FALLTHROUGH */
1573                         case O_IP6_DST_ME:
1574                                 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6);
1575 #endif
1576                                 break;
1577
1578
1579                         case O_IP_SRCPORT:
1580                         case O_IP_DSTPORT:
1581                                 /*
1582                                  * offset == 0 && proto != 0 is enough
1583                                  * to guarantee that we have a
1584                                  * packet with port info.
1585                                  */
1586                                 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP)
1587                                     && offset == 0) {
1588                                         u_int16_t x =
1589                                             (cmd->opcode == O_IP_SRCPORT) ?
1590                                                 src_port : dst_port ;
1591                                         u_int16_t *p =
1592                                             ((ipfw_insn_u16 *)cmd)->ports;
1593                                         int i;
1594
1595                                         for (i = cmdlen - 1; !match && i>0;
1596                                             i--, p += 2)
1597                                                 match = (x>=p[0] && x<=p[1]);
1598                                 }
1599                                 break;
1600
1601                         case O_ICMPTYPE:
1602                                 match = (offset == 0 && proto==IPPROTO_ICMP &&
1603                                     icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) );
1604                                 break;
1605
1606 #ifdef INET6
1607                         case O_ICMP6TYPE:
1608                                 match = is_ipv6 && offset == 0 &&
1609                                     proto==IPPROTO_ICMPV6 &&
1610                                     icmp6type_match(
1611                                         ICMP6(ulp)->icmp6_type,
1612                                         (ipfw_insn_u32 *)cmd);
1613                                 break;
1614 #endif /* INET6 */
1615
1616                         case O_IPOPT:
1617                                 match = (is_ipv4 &&
1618                                     ipopts_match(ip, cmd) );
1619                                 break;
1620
1621                         case O_IPVER:
1622                                 match = (is_ipv4 &&
1623                                     cmd->arg1 == ip->ip_v);
1624                                 break;
1625
1626                         case O_IPID:
1627                         case O_IPLEN:
1628                         case O_IPTTL:
1629                                 if (is_ipv4) {  /* only for IP packets */
1630                                     uint16_t x;
1631                                     uint16_t *p;
1632                                     int i;
1633
1634                                     if (cmd->opcode == O_IPLEN)
1635                                         x = iplen;
1636                                     else if (cmd->opcode == O_IPTTL)
1637                                         x = ip->ip_ttl;
1638                                     else /* must be IPID */
1639                                         x = ntohs(ip->ip_id);
1640                                     if (cmdlen == 1) {
1641                                         match = (cmd->arg1 == x);
1642                                         break;
1643                                     }
1644                                     /* otherwise we have ranges */
1645                                     p = ((ipfw_insn_u16 *)cmd)->ports;
1646                                     i = cmdlen - 1;
1647                                     for (; !match && i>0; i--, p += 2)
1648                                         match = (x >= p[0] && x <= p[1]);
1649                                 }
1650                                 break;
1651
1652                         case O_IPPRECEDENCE:
1653                                 match = (is_ipv4 &&
1654                                     (cmd->arg1 == (ip->ip_tos & 0xe0)) );
1655                                 break;
1656
1657                         case O_IPTOS:
1658                                 match = (is_ipv4 &&
1659                                     flags_match(cmd, ip->ip_tos));
1660                                 break;
1661
1662                         case O_DSCP:
1663                             {
1664                                 uint32_t *p;
1665                                 uint16_t x;
1666
1667                                 p = ((ipfw_insn_u32 *)cmd)->d;
1668
1669                                 if (is_ipv4)
1670                                         x = ip->ip_tos >> 2;
1671                                 else if (is_ipv6) {
1672                                         uint8_t *v;
1673                                         v = &((struct ip6_hdr *)ip)->ip6_vfc;
1674                                         x = (*v & 0x0F) << 2;
1675                                         v++;
1676                                         x |= *v >> 6;
1677                                 } else
1678                                         break;
1679
1680                                 /* DSCP bitmask is stored as low_u32 high_u32 */
1681                                 if (x > 32)
1682                                         match = *(p + 1) & (1 << (x - 32));
1683                                 else
1684                                         match = *p & (1 << x);
1685                             }
1686                                 break;
1687
1688                         case O_TCPDATALEN:
1689                                 if (proto == IPPROTO_TCP && offset == 0) {
1690                                     struct tcphdr *tcp;
1691                                     uint16_t x;
1692                                     uint16_t *p;
1693                                     int i;
1694
1695                                     tcp = TCP(ulp);
1696                                     x = iplen -
1697                                         ((ip->ip_hl + tcp->th_off) << 2);
1698                                     if (cmdlen == 1) {
1699                                         match = (cmd->arg1 == x);
1700                                         break;
1701                                     }
1702                                     /* otherwise we have ranges */
1703                                     p = ((ipfw_insn_u16 *)cmd)->ports;
1704                                     i = cmdlen - 1;
1705                                     for (; !match && i>0; i--, p += 2)
1706                                         match = (x >= p[0] && x <= p[1]);
1707                                 }
1708                                 break;
1709
1710                         case O_TCPFLAGS:
1711                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1712                                     flags_match(cmd, TCP(ulp)->th_flags));
1713                                 break;
1714
1715                         case O_TCPOPTS:
1716                                 PULLUP_LEN(hlen, ulp, (TCP(ulp)->th_off << 2));
1717                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1718                                     tcpopts_match(TCP(ulp), cmd));
1719                                 break;
1720
1721                         case O_TCPSEQ:
1722                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1723                                     ((ipfw_insn_u32 *)cmd)->d[0] ==
1724                                         TCP(ulp)->th_seq);
1725                                 break;
1726
1727                         case O_TCPACK:
1728                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1729                                     ((ipfw_insn_u32 *)cmd)->d[0] ==
1730                                         TCP(ulp)->th_ack);
1731                                 break;
1732
1733                         case O_TCPWIN:
1734                                 if (proto == IPPROTO_TCP && offset == 0) {
1735                                     uint16_t x;
1736                                     uint16_t *p;
1737                                     int i;
1738
1739                                     x = ntohs(TCP(ulp)->th_win);
1740                                     if (cmdlen == 1) {
1741                                         match = (cmd->arg1 == x);
1742                                         break;
1743                                     }
1744                                     /* Otherwise we have ranges. */
1745                                     p = ((ipfw_insn_u16 *)cmd)->ports;
1746                                     i = cmdlen - 1;
1747                                     for (; !match && i > 0; i--, p += 2)
1748                                         match = (x >= p[0] && x <= p[1]);
1749                                 }
1750                                 break;
1751
1752                         case O_ESTAB:
1753                                 /* reject packets which have SYN only */
1754                                 /* XXX should i also check for TH_ACK ? */
1755                                 match = (proto == IPPROTO_TCP && offset == 0 &&
1756                                     (TCP(ulp)->th_flags &
1757                                      (TH_RST | TH_ACK | TH_SYN)) != TH_SYN);
1758                                 break;
1759
1760                         case O_ALTQ: {
1761                                 struct pf_mtag *at;
1762                                 struct m_tag *mtag;
1763                                 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd;
1764
1765                                 /*
1766                                  * ALTQ uses mbuf tags from another
1767                                  * packet filtering system - pf(4).
1768                                  * We allocate a tag in its format
1769                                  * and fill it in, pretending to be pf(4).
1770                                  */
1771                                 match = 1;
1772                                 at = pf_find_mtag(m);
1773                                 if (at != NULL && at->qid != 0)
1774                                         break;
1775                                 mtag = m_tag_get(PACKET_TAG_PF,
1776                                     sizeof(struct pf_mtag), M_NOWAIT | M_ZERO);
1777                                 if (mtag == NULL) {
1778                                         /*
1779                                          * Let the packet fall back to the
1780                                          * default ALTQ.
1781                                          */
1782                                         break;
1783                                 }
1784                                 m_tag_prepend(m, mtag);
1785                                 at = (struct pf_mtag *)(mtag + 1);
1786                                 at->qid = altq->qid;
1787                                 at->hdr = ip;
1788                                 break;
1789                         }
1790
1791                         case O_LOG:
1792                                 ipfw_log(f, hlen, args, m,
1793                                     oif, offset | ip6f_mf, tablearg, ip);
1794                                 match = 1;
1795                                 break;
1796
1797                         case O_PROB:
1798                                 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]);
1799                                 break;
1800
1801                         case O_VERREVPATH:
1802                                 /* Outgoing packets automatically pass/match */
1803                                 match = ((oif != NULL) ||
1804                                     (m->m_pkthdr.rcvif == NULL) ||
1805                                     (
1806 #ifdef INET6
1807                                     is_ipv6 ?
1808                                         verify_path6(&(args->f_id.src_ip6),
1809                                             m->m_pkthdr.rcvif, args->f_id.fib) :
1810 #endif
1811                                     verify_path(src_ip, m->m_pkthdr.rcvif,
1812                                         args->f_id.fib)));
1813                                 break;
1814
1815                         case O_VERSRCREACH:
1816                                 /* Outgoing packets automatically pass/match */
1817                                 match = (hlen > 0 && ((oif != NULL) ||
1818 #ifdef INET6
1819                                     is_ipv6 ?
1820                                         verify_path6(&(args->f_id.src_ip6),
1821                                             NULL, args->f_id.fib) :
1822 #endif
1823                                     verify_path(src_ip, NULL, args->f_id.fib)));
1824                                 break;
1825
1826                         case O_ANTISPOOF:
1827                                 /* Outgoing packets automatically pass/match */
1828                                 if (oif == NULL && hlen > 0 &&
1829                                     (  (is_ipv4 && in_localaddr(src_ip))
1830 #ifdef INET6
1831                                     || (is_ipv6 &&
1832                                         in6_localaddr(&(args->f_id.src_ip6)))
1833 #endif
1834                                     ))
1835                                         match =
1836 #ifdef INET6
1837                                             is_ipv6 ? verify_path6(
1838                                                 &(args->f_id.src_ip6),
1839                                                 m->m_pkthdr.rcvif,
1840                                                 args->f_id.fib) :
1841 #endif
1842                                             verify_path(src_ip,
1843                                                 m->m_pkthdr.rcvif,
1844                                                 args->f_id.fib);
1845                                 else
1846                                         match = 1;
1847                                 break;
1848
1849                         case O_IPSEC:
1850 #ifdef IPSEC
1851                                 match = (m_tag_find(m,
1852                                     PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL);
1853 #endif
1854                                 /* otherwise no match */
1855                                 break;
1856
1857 #ifdef INET6
1858                         case O_IP6_SRC:
1859                                 match = is_ipv6 &&
1860                                     IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6,
1861                                     &((ipfw_insn_ip6 *)cmd)->addr6);
1862                                 break;
1863
1864                         case O_IP6_DST:
1865                                 match = is_ipv6 &&
1866                                 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6,
1867                                     &((ipfw_insn_ip6 *)cmd)->addr6);
1868                                 break;
1869                         case O_IP6_SRC_MASK:
1870                         case O_IP6_DST_MASK:
1871                                 if (is_ipv6) {
1872                                         int i = cmdlen - 1;
1873                                         struct in6_addr p;
1874                                         struct in6_addr *d =
1875                                             &((ipfw_insn_ip6 *)cmd)->addr6;
1876
1877                                         for (; !match && i > 0; d += 2,
1878                                             i -= F_INSN_SIZE(struct in6_addr)
1879                                             * 2) {
1880                                                 p = (cmd->opcode ==
1881                                                     O_IP6_SRC_MASK) ?
1882                                                     args->f_id.src_ip6:
1883                                                     args->f_id.dst_ip6;
1884                                                 APPLY_MASK(&p, &d[1]);
1885                                                 match =
1886                                                     IN6_ARE_ADDR_EQUAL(&d[0],
1887                                                     &p);
1888                                         }
1889                                 }
1890                                 break;
1891
1892                         case O_FLOW6ID:
1893                                 match = is_ipv6 &&
1894                                     flow6id_match(args->f_id.flow_id6,
1895                                     (ipfw_insn_u32 *) cmd);
1896                                 break;
1897
1898                         case O_EXT_HDR:
1899                                 match = is_ipv6 &&
1900                                     (ext_hd & ((ipfw_insn *) cmd)->arg1);
1901                                 break;
1902
1903                         case O_IP6:
1904                                 match = is_ipv6;
1905                                 break;
1906 #endif
1907
1908                         case O_IP4:
1909                                 match = is_ipv4;
1910                                 break;
1911
1912                         case O_TAG: {
1913                                 struct m_tag *mtag;
1914                                 uint32_t tag = IP_FW_ARG_TABLEARG(cmd->arg1);
1915
1916                                 /* Packet is already tagged with this tag? */
1917                                 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL);
1918
1919                                 /* We have `untag' action when F_NOT flag is
1920                                  * present. And we must remove this mtag from
1921                                  * mbuf and reset `match' to zero (`match' will
1922                                  * be inversed later).
1923                                  * Otherwise we should allocate new mtag and
1924                                  * push it into mbuf.
1925                                  */
1926                                 if (cmd->len & F_NOT) { /* `untag' action */
1927                                         if (mtag != NULL)
1928                                                 m_tag_delete(m, mtag);
1929                                         match = 0;
1930                                 } else {
1931                                         if (mtag == NULL) {
1932                                                 mtag = m_tag_alloc( MTAG_IPFW,
1933                                                     tag, 0, M_NOWAIT);
1934                                                 if (mtag != NULL)
1935                                                         m_tag_prepend(m, mtag);
1936                                         }
1937                                         match = 1;
1938                                 }
1939                                 break;
1940                         }
1941
1942                         case O_FIB: /* try match the specified fib */
1943                                 if (args->f_id.fib == cmd->arg1)
1944                                         match = 1;
1945                                 break;
1946
1947                         case O_SOCKARG: {
1948                                 struct inpcb *inp = args->inp;
1949                                 struct inpcbinfo *pi;
1950
1951                                 if (is_ipv6) /* XXX can we remove this ? */
1952                                         break;
1953
1954                                 if (proto == IPPROTO_TCP)
1955                                         pi = &V_tcbinfo;
1956                                 else if (proto == IPPROTO_UDP)
1957                                         pi = &V_udbinfo;
1958                                 else
1959                                         break;
1960
1961                                 /*
1962                                  * XXXRW: so_user_cookie should almost
1963                                  * certainly be inp_user_cookie?
1964                                  */
1965
1966                                 /* For incomming packet, lookup up the
1967                                 inpcb using the src/dest ip/port tuple */
1968                                 if (inp == NULL) {
1969                                         inp = in_pcblookup(pi,
1970                                                 src_ip, htons(src_port),
1971                                                 dst_ip, htons(dst_port),
1972                                                 INPLOOKUP_RLOCKPCB, NULL);
1973                                         if (inp != NULL) {
1974                                                 tablearg =
1975                                                     inp->inp_socket->so_user_cookie;
1976                                                 if (tablearg)
1977                                                         match = 1;
1978                                                 INP_RUNLOCK(inp);
1979                                         }
1980                                 } else {
1981                                         if (inp->inp_socket) {
1982                                                 tablearg =
1983                                                     inp->inp_socket->so_user_cookie;
1984                                                 if (tablearg)
1985                                                         match = 1;
1986                                         }
1987                                 }
1988                                 break;
1989                         }
1990
1991                         case O_TAGGED: {
1992                                 struct m_tag *mtag;
1993                                 uint32_t tag = IP_FW_ARG_TABLEARG(cmd->arg1);
1994
1995                                 if (cmdlen == 1) {
1996                                         match = m_tag_locate(m, MTAG_IPFW,
1997                                             tag, NULL) != NULL;
1998                                         break;
1999                                 }
2000
2001                                 /* we have ranges */
2002                                 for (mtag = m_tag_first(m);
2003                                     mtag != NULL && !match;
2004                                     mtag = m_tag_next(m, mtag)) {
2005                                         uint16_t *p;
2006                                         int i;
2007
2008                                         if (mtag->m_tag_cookie != MTAG_IPFW)
2009                                                 continue;
2010
2011                                         p = ((ipfw_insn_u16 *)cmd)->ports;
2012                                         i = cmdlen - 1;
2013                                         for(; !match && i > 0; i--, p += 2)
2014                                                 match =
2015                                                     mtag->m_tag_id >= p[0] &&
2016                                                     mtag->m_tag_id <= p[1];
2017                                 }
2018                                 break;
2019                         }
2020
2021                         /*
2022                          * The second set of opcodes represents 'actions',
2023                          * i.e. the terminal part of a rule once the packet
2024                          * matches all previous patterns.
2025                          * Typically there is only one action for each rule,
2026                          * and the opcode is stored at the end of the rule
2027                          * (but there are exceptions -- see below).
2028                          *
2029                          * In general, here we set retval and terminate the
2030                          * outer loop (would be a 'break 3' in some language,
2031                          * but we need to set l=0, done=1)
2032                          *
2033                          * Exceptions:
2034                          * O_COUNT and O_SKIPTO actions:
2035                          *   instead of terminating, we jump to the next rule
2036                          *   (setting l=0), or to the SKIPTO target (setting
2037                          *   f/f_len, cmd and l as needed), respectively.
2038                          *
2039                          * O_TAG, O_LOG and O_ALTQ action parameters:
2040                          *   perform some action and set match = 1;
2041                          *
2042                          * O_LIMIT and O_KEEP_STATE: these opcodes are
2043                          *   not real 'actions', and are stored right
2044                          *   before the 'action' part of the rule.
2045                          *   These opcodes try to install an entry in the
2046                          *   state tables; if successful, we continue with
2047                          *   the next opcode (match=1; break;), otherwise
2048                          *   the packet must be dropped (set retval,
2049                          *   break loops with l=0, done=1)
2050                          *
2051                          * O_PROBE_STATE and O_CHECK_STATE: these opcodes
2052                          *   cause a lookup of the state table, and a jump
2053                          *   to the 'action' part of the parent rule
2054                          *   if an entry is found, or
2055                          *   (CHECK_STATE only) a jump to the next rule if
2056                          *   the entry is not found.
2057                          *   The result of the lookup is cached so that
2058                          *   further instances of these opcodes become NOPs.
2059                          *   The jump to the next rule is done by setting
2060                          *   l=0, cmdlen=0.
2061                          */
2062                         case O_LIMIT:
2063                         case O_KEEP_STATE:
2064                                 if (ipfw_install_state(f,
2065                                     (ipfw_insn_limit *)cmd, args, tablearg)) {
2066                                         /* error or limit violation */
2067                                         retval = IP_FW_DENY;
2068                                         l = 0;  /* exit inner loop */
2069                                         done = 1; /* exit outer loop */
2070                                 }
2071                                 match = 1;
2072                                 break;
2073
2074                         case O_PROBE_STATE:
2075                         case O_CHECK_STATE:
2076                                 /*
2077                                  * dynamic rules are checked at the first
2078                                  * keep-state or check-state occurrence,
2079                                  * with the result being stored in dyn_dir.
2080                                  * The compiler introduces a PROBE_STATE
2081                                  * instruction for us when we have a
2082                                  * KEEP_STATE (because PROBE_STATE needs
2083                                  * to be run first).
2084                                  */
2085                                 if (dyn_dir == MATCH_UNKNOWN &&
2086                                     (q = ipfw_lookup_dyn_rule(&args->f_id,
2087                                      &dyn_dir, proto == IPPROTO_TCP ?
2088                                         TCP(ulp) : NULL))
2089                                         != NULL) {
2090                                         /*
2091                                          * Found dynamic entry, update stats
2092                                          * and jump to the 'action' part of
2093                                          * the parent rule by setting
2094                                          * f, cmd, l and clearing cmdlen.
2095                                          */
2096                                         IPFW_INC_DYN_COUNTER(q, pktlen);
2097                                         /* XXX we would like to have f_pos
2098                                          * readily accessible in the dynamic
2099                                          * rule, instead of having to
2100                                          * lookup q->rule.
2101                                          */
2102                                         f = q->rule;
2103                                         f_pos = ipfw_find_rule(chain,
2104                                                 f->rulenum, f->id);
2105                                         cmd = ACTION_PTR(f);
2106                                         l = f->cmd_len - f->act_ofs;
2107                                         ipfw_dyn_unlock(q);
2108                                         cmdlen = 0;
2109                                         match = 1;
2110                                         break;
2111                                 }
2112                                 /*
2113                                  * Dynamic entry not found. If CHECK_STATE,
2114                                  * skip to next rule, if PROBE_STATE just
2115                                  * ignore and continue with next opcode.
2116                                  */
2117                                 if (cmd->opcode == O_CHECK_STATE)
2118                                         l = 0;  /* exit inner loop */
2119                                 match = 1;
2120                                 break;
2121
2122                         case O_ACCEPT:
2123                                 retval = 0;     /* accept */
2124                                 l = 0;          /* exit inner loop */
2125                                 done = 1;       /* exit outer loop */
2126                                 break;
2127
2128                         case O_PIPE:
2129                         case O_QUEUE:
2130                                 set_match(args, f_pos, chain);
2131                                 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1);
2132                                 if (cmd->opcode == O_PIPE)
2133                                         args->rule.info |= IPFW_IS_PIPE;
2134                                 if (V_fw_one_pass)
2135                                         args->rule.info |= IPFW_ONEPASS;
2136                                 retval = IP_FW_DUMMYNET;
2137                                 l = 0;          /* exit inner loop */
2138                                 done = 1;       /* exit outer loop */
2139                                 break;
2140
2141                         case O_DIVERT:
2142                         case O_TEE:
2143                                 if (args->eh) /* not on layer 2 */
2144                                     break;
2145                                 /* otherwise this is terminal */
2146                                 l = 0;          /* exit inner loop */
2147                                 done = 1;       /* exit outer loop */
2148                                 retval = (cmd->opcode == O_DIVERT) ?
2149                                         IP_FW_DIVERT : IP_FW_TEE;
2150                                 set_match(args, f_pos, chain);
2151                                 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1);
2152                                 break;
2153
2154                         case O_COUNT:
2155                                 IPFW_INC_RULE_COUNTER(f, pktlen);
2156                                 l = 0;          /* exit inner loop */
2157                                 break;
2158
2159                         case O_SKIPTO:
2160                             IPFW_INC_RULE_COUNTER(f, pktlen);
2161                             f_pos = jump_fast(chain, f, cmd->arg1, tablearg, 0);
2162                             /*
2163                              * Skip disabled rules, and re-enter
2164                              * the inner loop with the correct
2165                              * f_pos, f, l and cmd.
2166                              * Also clear cmdlen and skip_or
2167                              */
2168                             for (; f_pos < chain->n_rules - 1 &&
2169                                     (V_set_disable &
2170                                      (1 << chain->map[f_pos]->set));
2171                                     f_pos++)
2172                                 ;
2173                             /* Re-enter the inner loop at the skipto rule. */
2174                             f = chain->map[f_pos];
2175                             l = f->cmd_len;
2176                             cmd = f->cmd;
2177                             match = 1;
2178                             cmdlen = 0;
2179                             skip_or = 0;
2180                             continue;
2181                             break;      /* not reached */
2182
2183                         case O_CALLRETURN: {
2184                                 /*
2185                                  * Implementation of `subroutine' call/return,
2186                                  * in the stack carried in an mbuf tag. This
2187                                  * is different from `skipto' in that any call
2188                                  * address is possible (`skipto' must prevent
2189                                  * backward jumps to avoid endless loops).
2190                                  * We have `return' action when F_NOT flag is
2191                                  * present. The `m_tag_id' field is used as
2192                                  * stack pointer.
2193                                  */
2194                                 struct m_tag *mtag;
2195                                 uint16_t jmpto, *stack;
2196
2197 #define IS_CALL         ((cmd->len & F_NOT) == 0)
2198 #define IS_RETURN       ((cmd->len & F_NOT) != 0)
2199                                 /*
2200                                  * Hand-rolled version of m_tag_locate() with
2201                                  * wildcard `type'.
2202                                  * If not already tagged, allocate new tag.
2203                                  */
2204                                 mtag = m_tag_first(m);
2205                                 while (mtag != NULL) {
2206                                         if (mtag->m_tag_cookie ==
2207                                             MTAG_IPFW_CALL)
2208                                                 break;
2209                                         mtag = m_tag_next(m, mtag);
2210                                 }
2211                                 if (mtag == NULL && IS_CALL) {
2212                                         mtag = m_tag_alloc(MTAG_IPFW_CALL, 0,
2213                                             IPFW_CALLSTACK_SIZE *
2214                                             sizeof(uint16_t), M_NOWAIT);
2215                                         if (mtag != NULL)
2216                                                 m_tag_prepend(m, mtag);
2217                                 }
2218
2219                                 /*
2220                                  * On error both `call' and `return' just
2221                                  * continue with next rule.
2222                                  */
2223                                 if (IS_RETURN && (mtag == NULL ||
2224                                     mtag->m_tag_id == 0)) {
2225                                         l = 0;          /* exit inner loop */
2226                                         break;
2227                                 }
2228                                 if (IS_CALL && (mtag == NULL ||
2229                                     mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) {
2230                                         printf("ipfw: call stack error, "
2231                                             "go to next rule\n");
2232                                         l = 0;          /* exit inner loop */
2233                                         break;
2234                                 }
2235
2236                                 IPFW_INC_RULE_COUNTER(f, pktlen);
2237                                 stack = (uint16_t *)(mtag + 1);
2238
2239                                 /*
2240                                  * The `call' action may use cached f_pos
2241                                  * (in f->next_rule), whose version is written
2242                                  * in f->next_rule.
2243                                  * The `return' action, however, doesn't have
2244                                  * fixed jump address in cmd->arg1 and can't use
2245                                  * cache.
2246                                  */
2247                                 if (IS_CALL) {
2248                                         stack[mtag->m_tag_id] = f->rulenum;
2249                                         mtag->m_tag_id++;
2250                                         f_pos = jump_fast(chain, f, cmd->arg1,
2251                                             tablearg, 1);
2252                                 } else {        /* `return' action */
2253                                         mtag->m_tag_id--;
2254                                         jmpto = stack[mtag->m_tag_id] + 1;
2255                                         f_pos = ipfw_find_rule(chain, jmpto, 0);
2256                                 }
2257
2258                                 /*
2259                                  * Skip disabled rules, and re-enter
2260                                  * the inner loop with the correct
2261                                  * f_pos, f, l and cmd.
2262                                  * Also clear cmdlen and skip_or
2263                                  */
2264                                 for (; f_pos < chain->n_rules - 1 &&
2265                                     (V_set_disable &
2266                                     (1 << chain->map[f_pos]->set)); f_pos++)
2267                                         ;
2268                                 /* Re-enter the inner loop at the dest rule. */
2269                                 f = chain->map[f_pos];
2270                                 l = f->cmd_len;
2271                                 cmd = f->cmd;
2272                                 cmdlen = 0;
2273                                 skip_or = 0;
2274                                 continue;
2275                                 break;  /* NOTREACHED */
2276                         }
2277 #undef IS_CALL
2278 #undef IS_RETURN
2279
2280                         case O_REJECT:
2281                                 /*
2282                                  * Drop the packet and send a reject notice
2283                                  * if the packet is not ICMP (or is an ICMP
2284                                  * query), and it is not multicast/broadcast.
2285                                  */
2286                                 if (hlen > 0 && is_ipv4 && offset == 0 &&
2287                                     (proto != IPPROTO_ICMP ||
2288                                      is_icmp_query(ICMP(ulp))) &&
2289                                     !(m->m_flags & (M_BCAST|M_MCAST)) &&
2290                                     !IN_MULTICAST(ntohl(dst_ip.s_addr))) {
2291                                         send_reject(args, cmd->arg1, iplen, ip);
2292                                         m = args->m;
2293                                 }
2294                                 /* FALLTHROUGH */
2295 #ifdef INET6
2296                         case O_UNREACH6:
2297                                 if (hlen > 0 && is_ipv6 &&
2298                                     ((offset & IP6F_OFF_MASK) == 0) &&
2299                                     (proto != IPPROTO_ICMPV6 ||
2300                                      (is_icmp6_query(icmp6_type) == 1)) &&
2301                                     !(m->m_flags & (M_BCAST|M_MCAST)) &&
2302                                     !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) {
2303                                         send_reject6(
2304                                             args, cmd->arg1, hlen,
2305                                             (struct ip6_hdr *)ip);
2306                                         m = args->m;
2307                                 }
2308                                 /* FALLTHROUGH */
2309 #endif
2310                         case O_DENY:
2311                                 retval = IP_FW_DENY;
2312                                 l = 0;          /* exit inner loop */
2313                                 done = 1;       /* exit outer loop */
2314                                 break;
2315
2316                         case O_FORWARD_IP:
2317                                 if (args->eh)   /* not valid on layer2 pkts */
2318                                         break;
2319                                 if (q == NULL || q->rule != f ||
2320                                     dyn_dir == MATCH_FORWARD) {
2321                                     struct sockaddr_in *sa;
2322                                     sa = &(((ipfw_insn_sa *)cmd)->sa);
2323                                     if (sa->sin_addr.s_addr == INADDR_ANY) {
2324                                         bcopy(sa, &args->hopstore,
2325                                                         sizeof(*sa));
2326                                         args->hopstore.sin_addr.s_addr =
2327                                                     htonl(tablearg);
2328                                         args->next_hop = &args->hopstore;
2329                                     } else {
2330                                         args->next_hop = sa;
2331                                     }
2332                                 }
2333                                 retval = IP_FW_PASS;
2334                                 l = 0;          /* exit inner loop */
2335                                 done = 1;       /* exit outer loop */
2336                                 break;
2337
2338 #ifdef INET6
2339                         case O_FORWARD_IP6:
2340                                 if (args->eh)   /* not valid on layer2 pkts */
2341                                         break;
2342                                 if (q == NULL || q->rule != f ||
2343                                     dyn_dir == MATCH_FORWARD) {
2344                                         struct sockaddr_in6 *sin6;
2345
2346                                         sin6 = &(((ipfw_insn_sa6 *)cmd)->sa);
2347                                         args->next_hop6 = sin6;
2348                                 }
2349                                 retval = IP_FW_PASS;
2350                                 l = 0;          /* exit inner loop */
2351                                 done = 1;       /* exit outer loop */
2352                                 break;
2353 #endif
2354
2355                         case O_NETGRAPH:
2356                         case O_NGTEE:
2357                                 set_match(args, f_pos, chain);
2358                                 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1);
2359                                 if (V_fw_one_pass)
2360                                         args->rule.info |= IPFW_ONEPASS;
2361                                 retval = (cmd->opcode == O_NETGRAPH) ?
2362                                     IP_FW_NETGRAPH : IP_FW_NGTEE;
2363                                 l = 0;          /* exit inner loop */
2364                                 done = 1;       /* exit outer loop */
2365                                 break;
2366
2367                         case O_SETFIB: {
2368                                 uint32_t fib;
2369
2370                                 IPFW_INC_RULE_COUNTER(f, pktlen);
2371                                 fib = IP_FW_ARG_TABLEARG(cmd->arg1);
2372                                 if (fib >= rt_numfibs)
2373                                         fib = 0;
2374                                 M_SETFIB(m, fib);
2375                                 args->f_id.fib = fib;
2376                                 l = 0;          /* exit inner loop */
2377                                 break;
2378                         }
2379
2380                         case O_SETDSCP: {
2381                                 uint16_t code;
2382
2383                                 code = IP_FW_ARG_TABLEARG(cmd->arg1) & 0x3F;
2384                                 l = 0;          /* exit inner loop */
2385                                 if (is_ipv4) {
2386                                         uint16_t a;
2387
2388                                         a = ip->ip_tos;
2389                                         ip->ip_tos = (code << 2) | (ip->ip_tos & 0x03);
2390                                         a += ntohs(ip->ip_sum) - ip->ip_tos;
2391                                         ip->ip_sum = htons(a);
2392                                 } else if (is_ipv6) {
2393                                         uint8_t *v;
2394
2395                                         v = &((struct ip6_hdr *)ip)->ip6_vfc;
2396                                         *v = (*v & 0xF0) | (code >> 2);
2397                                         v++;
2398                                         *v = (*v & 0x3F) | ((code & 0x03) << 6);
2399                                 } else
2400                                         break;
2401
2402                                 IPFW_INC_RULE_COUNTER(f, pktlen);
2403                                 break;
2404                         }
2405
2406                         case O_NAT:
2407                                 l = 0;          /* exit inner loop */
2408                                 done = 1;       /* exit outer loop */
2409                                 if (!IPFW_NAT_LOADED) {
2410                                     retval = IP_FW_DENY;
2411                                     break;
2412                                 }
2413
2414                                 struct cfg_nat *t;
2415                                 int nat_id;
2416
2417                                 set_match(args, f_pos, chain);
2418                                 /* Check if this is 'global' nat rule */
2419                                 if (cmd->arg1 == 0) {
2420                                         retval = ipfw_nat_ptr(args, NULL, m);
2421                                         break;
2422                                 }
2423                                 t = ((ipfw_insn_nat *)cmd)->nat;
2424                                 if (t == NULL) {
2425                                         nat_id = IP_FW_ARG_TABLEARG(cmd->arg1);
2426                                         t = (*lookup_nat_ptr)(&chain->nat, nat_id);
2427
2428                                         if (t == NULL) {
2429                                             retval = IP_FW_DENY;
2430                                             break;
2431                                         }
2432                                         if (cmd->arg1 != IP_FW_TABLEARG)
2433                                             ((ipfw_insn_nat *)cmd)->nat = t;
2434                                 }
2435                                 retval = ipfw_nat_ptr(args, t, m);
2436                                 break;
2437
2438                         case O_REASS: {
2439                                 int ip_off;
2440
2441                                 IPFW_INC_RULE_COUNTER(f, pktlen);
2442                                 l = 0;  /* in any case exit inner loop */
2443                                 ip_off = ntohs(ip->ip_off);
2444
2445                                 /* if not fragmented, go to next rule */
2446                                 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0)
2447                                     break;
2448
2449                                 args->m = m = ip_reass(m);
2450
2451                                 /*
2452                                  * do IP header checksum fixup.
2453                                  */
2454                                 if (m == NULL) { /* fragment got swallowed */
2455                                     retval = IP_FW_DENY;
2456                                 } else { /* good, packet complete */
2457                                     int hlen;
2458
2459                                     ip = mtod(m, struct ip *);
2460                                     hlen = ip->ip_hl << 2;
2461                                     ip->ip_sum = 0;
2462                                     if (hlen == sizeof(struct ip))
2463                                         ip->ip_sum = in_cksum_hdr(ip);
2464                                     else
2465                                         ip->ip_sum = in_cksum(m, hlen);
2466                                     retval = IP_FW_REASS;
2467                                     set_match(args, f_pos, chain);
2468                                 }
2469                                 done = 1;       /* exit outer loop */
2470                                 break;
2471                         }
2472
2473                         default:
2474                                 panic("-- unknown opcode %d\n", cmd->opcode);
2475                         } /* end of switch() on opcodes */
2476                         /*
2477                          * if we get here with l=0, then match is irrelevant.
2478                          */
2479
2480                         if (cmd->len & F_NOT)
2481                                 match = !match;
2482
2483                         if (match) {
2484                                 if (cmd->len & F_OR)
2485                                         skip_or = 1;
2486                         } else {
2487                                 if (!(cmd->len & F_OR)) /* not an OR block, */
2488                                         break;          /* try next rule    */
2489                         }
2490
2491                 }       /* end of inner loop, scan opcodes */
2492 #undef PULLUP_LEN
2493
2494                 if (done)
2495                         break;
2496
2497 /* next_rule:; */       /* try next rule                */
2498
2499         }               /* end of outer for, scan rules */
2500
2501         if (done) {
2502                 struct ip_fw *rule = chain->map[f_pos];
2503                 /* Update statistics */
2504                 IPFW_INC_RULE_COUNTER(rule, pktlen);
2505         } else {
2506                 retval = IP_FW_DENY;
2507                 printf("ipfw: ouch!, skip past end of rules, denying packet\n");
2508         }
2509         IPFW_PF_RUNLOCK(chain);
2510 #ifdef __FreeBSD__
2511         if (ucred_cache != NULL)
2512                 crfree(ucred_cache);
2513 #endif
2514         return (retval);
2515
2516 pullup_failed:
2517         if (V_fw_verbose)
2518                 printf("ipfw: pullup failed\n");
2519         return (IP_FW_DENY);
2520 }
2521
2522 /*
2523  * Set maximum number of tables that can be used in given VNET ipfw instance.
2524  */
2525 #ifdef SYSCTL_NODE
2526 static int
2527 sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS)
2528 {
2529         int error;
2530         unsigned int ntables;
2531
2532         ntables = V_fw_tables_max;
2533
2534         error = sysctl_handle_int(oidp, &ntables, 0, req);
2535         /* Read operation or some error */
2536         if ((error != 0) || (req->newptr == NULL))
2537                 return (error);
2538
2539         return (ipfw_resize_tables(&V_layer3_chain, ntables));
2540 }
2541 #endif
2542 /*
2543  * Module and VNET glue
2544  */
2545
2546 /*
2547  * Stuff that must be initialised only on boot or module load
2548  */
2549 static int
2550 ipfw_init(void)
2551 {
2552         int error = 0;
2553
2554         /*
2555          * Only print out this stuff the first time around,
2556          * when called from the sysinit code.
2557          */
2558         printf("ipfw2 "
2559 #ifdef INET6
2560                 "(+ipv6) "
2561 #endif
2562                 "initialized, divert %s, nat %s, "
2563                 "default to %s, logging ",
2564 #ifdef IPDIVERT
2565                 "enabled",
2566 #else
2567                 "loadable",
2568 #endif
2569 #ifdef IPFIREWALL_NAT
2570                 "enabled",
2571 #else
2572                 "loadable",
2573 #endif
2574                 default_to_accept ? "accept" : "deny");
2575
2576         /*
2577          * Note: V_xxx variables can be accessed here but the vnet specific
2578          * initializer may not have been called yet for the VIMAGE case.
2579          * Tuneables will have been processed. We will print out values for
2580          * the default vnet.
2581          * XXX This should all be rationalized AFTER 8.0
2582          */
2583         if (V_fw_verbose == 0)
2584                 printf("disabled\n");
2585         else if (V_verbose_limit == 0)
2586                 printf("unlimited\n");
2587         else
2588                 printf("limited to %d packets/entry by default\n",
2589                     V_verbose_limit);
2590
2591         /* Check user-supplied table count for validness */
2592         if (default_fw_tables > IPFW_TABLES_MAX)
2593           default_fw_tables = IPFW_TABLES_MAX;
2594
2595         ipfw_log_bpf(1); /* init */
2596         return (error);
2597 }
2598
2599 /*
2600  * Called for the removal of the last instance only on module unload.
2601  */
2602 static void
2603 ipfw_destroy(void)
2604 {
2605
2606         ipfw_log_bpf(0); /* uninit */
2607         printf("IP firewall unloaded\n");
2608 }
2609
2610 /*
2611  * Stuff that must be initialized for every instance
2612  * (including the first of course).
2613  */
2614 static int
2615 vnet_ipfw_init(const void *unused)
2616 {
2617         int error;
2618         struct ip_fw *rule = NULL;
2619         struct ip_fw_chain *chain;
2620
2621         chain = &V_layer3_chain;
2622
2623         /* First set up some values that are compile time options */
2624         V_autoinc_step = 100;   /* bounded to 1..1000 in add_rule() */
2625         V_fw_deny_unknown_exthdrs = 1;
2626 #ifdef IPFIREWALL_VERBOSE
2627         V_fw_verbose = 1;
2628 #endif
2629 #ifdef IPFIREWALL_VERBOSE_LIMIT
2630         V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
2631 #endif
2632 #ifdef IPFIREWALL_NAT
2633         LIST_INIT(&chain->nat);
2634 #endif
2635
2636         /* insert the default rule and create the initial map */
2637         chain->n_rules = 1;
2638         chain->static_len = sizeof(struct ip_fw);
2639         chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_WAITOK | M_ZERO);
2640         if (chain->map)
2641                 rule = malloc(chain->static_len, M_IPFW, M_WAITOK | M_ZERO);
2642
2643         /* Set initial number of tables */
2644         V_fw_tables_max = default_fw_tables;
2645         error = ipfw_init_tables(chain);
2646         if (error) {
2647                 printf("ipfw2: setting up tables failed\n");
2648                 free(chain->map, M_IPFW);
2649                 free(rule, M_IPFW);
2650                 return (ENOSPC);
2651         }
2652
2653         /* fill and insert the default rule */
2654         rule->act_ofs = 0;
2655         rule->rulenum = IPFW_DEFAULT_RULE;
2656         rule->cmd_len = 1;
2657         rule->set = RESVD_SET;
2658         rule->cmd[0].len = 1;
2659         rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY;
2660         chain->default_rule = chain->map[0] = rule;
2661         chain->id = rule->id = 1;
2662
2663         IPFW_LOCK_INIT(chain);
2664         ipfw_dyn_init(chain);
2665
2666         /* First set up some values that are compile time options */
2667         V_ipfw_vnet_ready = 1;          /* Open for business */
2668
2669         /*
2670          * Hook the sockopt handler and pfil hooks for ipv4 and ipv6.
2671          * Even if the latter two fail we still keep the module alive
2672          * because the sockopt and layer2 paths are still useful.
2673          * ipfw[6]_hook return 0 on success, ENOENT on failure,
2674          * so we can ignore the exact return value and just set a flag.
2675          *
2676          * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so
2677          * changes in the underlying (per-vnet) variables trigger
2678          * immediate hook()/unhook() calls.
2679          * In layer2 we have the same behaviour, except that V_ether_ipfw
2680          * is checked on each packet because there are no pfil hooks.
2681          */
2682         V_ip_fw_ctl_ptr = ipfw_ctl;
2683         error = ipfw_attach_hooks(1);
2684         return (error);
2685 }
2686
2687 /*
2688  * Called for the removal of each instance.
2689  */
2690 static int
2691 vnet_ipfw_uninit(const void *unused)
2692 {
2693         struct ip_fw *reap, *rule;
2694         struct ip_fw_chain *chain = &V_layer3_chain;
2695         int i;
2696
2697         V_ipfw_vnet_ready = 0; /* tell new callers to go away */
2698         /*
2699          * disconnect from ipv4, ipv6, layer2 and sockopt.
2700          * Then grab, release and grab again the WLOCK so we make
2701          * sure the update is propagated and nobody will be in.
2702          */
2703         (void)ipfw_attach_hooks(0 /* detach */);
2704         V_ip_fw_ctl_ptr = NULL;
2705         IPFW_UH_WLOCK(chain);
2706         IPFW_UH_WUNLOCK(chain);
2707         IPFW_UH_WLOCK(chain);
2708
2709         IPFW_WLOCK(chain);
2710         ipfw_dyn_uninit(0);     /* run the callout_drain */
2711         IPFW_WUNLOCK(chain);
2712
2713         ipfw_destroy_tables(chain);
2714         reap = NULL;
2715         IPFW_WLOCK(chain);
2716         for (i = 0; i < chain->n_rules; i++) {
2717                 rule = chain->map[i];
2718                 rule->x_next = reap;
2719                 reap = rule;
2720         }
2721         if (chain->map)
2722                 free(chain->map, M_IPFW);
2723         IPFW_WUNLOCK(chain);
2724         IPFW_UH_WUNLOCK(chain);
2725         if (reap != NULL)
2726                 ipfw_reap_rules(reap);
2727         IPFW_LOCK_DESTROY(chain);
2728         ipfw_dyn_uninit(1);     /* free the remaining parts */
2729         return 0;
2730 }
2731
2732 /*
2733  * Module event handler.
2734  * In general we have the choice of handling most of these events by the
2735  * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to
2736  * use the SYSINIT handlers as they are more capable of expressing the
2737  * flow of control during module and vnet operations, so this is just
2738  * a skeleton. Note there is no SYSINIT equivalent of the module
2739  * SHUTDOWN handler, but we don't have anything to do in that case anyhow.
2740  */
2741 static int
2742 ipfw_modevent(module_t mod, int type, void *unused)
2743 {
2744         int err = 0;
2745
2746         switch (type) {
2747         case MOD_LOAD:
2748                 /* Called once at module load or
2749                  * system boot if compiled in. */
2750                 break;
2751         case MOD_QUIESCE:
2752                 /* Called before unload. May veto unloading. */
2753                 break;
2754         case MOD_UNLOAD:
2755                 /* Called during unload. */
2756                 break;
2757         case MOD_SHUTDOWN:
2758                 /* Called during system shutdown. */
2759                 break;
2760         default:
2761                 err = EOPNOTSUPP;
2762                 break;
2763         }
2764         return err;
2765 }
2766
2767 static moduledata_t ipfwmod = {
2768         "ipfw",
2769         ipfw_modevent,
2770         0
2771 };
2772
2773 /* Define startup order. */
2774 #define IPFW_SI_SUB_FIREWALL    SI_SUB_PROTO_IFATTACHDOMAIN
2775 #define IPFW_MODEVENT_ORDER     (SI_ORDER_ANY - 255) /* On boot slot in here. */
2776 #define IPFW_MODULE_ORDER       (IPFW_MODEVENT_ORDER + 1) /* A little later. */
2777 #define IPFW_VNET_ORDER         (IPFW_MODEVENT_ORDER + 2) /* Later still. */
2778
2779 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER);
2780 MODULE_VERSION(ipfw, 2);
2781 /* should declare some dependencies here */
2782
2783 /*
2784  * Starting up. Done in order after ipfwmod() has been called.
2785  * VNET_SYSINIT is also called for each existing vnet and each new vnet.
2786  */
2787 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
2788             ipfw_init, NULL);
2789 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
2790             vnet_ipfw_init, NULL);
2791
2792 /*
2793  * Closing up shop. These are done in REVERSE ORDER, but still
2794  * after ipfwmod() has been called. Not called on reboot.
2795  * VNET_SYSUNINIT is also called for each exiting vnet as it exits.
2796  * or when the module is unloaded.
2797  */
2798 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
2799             ipfw_destroy, NULL);
2800 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
2801             vnet_ipfw_uninit, NULL);
2802 /* end of file */