1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2002-2009 Luigi Rizzo, Universita` di Pisa 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 /* 32 * The FreeBSD IP packet firewall, main file 33 */ 34 35 #include "opt_ipfw.h" 36 #include "opt_ipdivert.h" 37 #include "opt_inet.h" 38 #ifndef INET 39 #error "IPFIREWALL requires INET" 40 #endif /* INET */ 41 #include "opt_inet6.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/condvar.h> 46 #include <sys/counter.h> 47 #include <sys/eventhandler.h> 48 #include <sys/malloc.h> 49 #include <sys/mbuf.h> 50 #include <sys/kernel.h> 51 #include <sys/lock.h> 52 #include <sys/jail.h> 53 #include <sys/module.h> 54 #include <sys/priv.h> 55 #include <sys/proc.h> 56 #include <sys/rwlock.h> 57 #include <sys/rmlock.h> 58 #include <sys/sdt.h> 59 #include <sys/socket.h> 60 #include <sys/socketvar.h> 61 #include <sys/sysctl.h> 62 #include <sys/syslog.h> 63 #include <sys/ucred.h> 64 #include <net/ethernet.h> /* for ETHERTYPE_IP */ 65 #include <net/if.h> 66 #include <net/if_var.h> 67 #include <net/route.h> 68 #include <net/route/nhop.h> 69 #include <net/pfil.h> 70 #include <net/vnet.h> 71 72 #include <netpfil/pf/pf_mtag.h> 73 74 #include <netinet/in.h> 75 #include <netinet/in_var.h> 76 #include <netinet/in_pcb.h> 77 #include <netinet/ip.h> 78 #include <netinet/ip_var.h> 79 #include <netinet/ip_icmp.h> 80 #include <netinet/ip_fw.h> 81 #include <netinet/ip_carp.h> 82 #include <netinet/pim.h> 83 #include <netinet/tcp_var.h> 84 #include <netinet/udp.h> 85 #include <netinet/udp_var.h> 86 #include <netinet/sctp.h> 87 #include <netinet/sctp_crc32.h> 88 #include <netinet/sctp_header.h> 89 90 #include <netinet/ip6.h> 91 #include <netinet/icmp6.h> 92 #include <netinet/in_fib.h> 93 #ifdef INET6 94 #include <netinet6/in6_fib.h> 95 #include <netinet6/in6_pcb.h> 96 #include <netinet6/scope6_var.h> 97 #include <netinet6/ip6_var.h> 98 #endif 99 100 #include <net/if_gre.h> /* for struct grehdr */ 101 102 #include <netpfil/ipfw/ip_fw_private.h> 103 104 #include <machine/in_cksum.h> /* XXX for in_cksum */ 105 106 #ifdef MAC 107 #include <security/mac/mac_framework.h> 108 #endif 109 110 #define IPFW_PROBE(probe, arg0, arg1, arg2, arg3, arg4, arg5) \ 111 SDT_PROBE6(ipfw, , , probe, arg0, arg1, arg2, arg3, arg4, arg5) 112 113 SDT_PROVIDER_DEFINE(ipfw); 114 SDT_PROBE_DEFINE6(ipfw, , , rule__matched, 115 "int", /* retval */ 116 "int", /* af */ 117 "void *", /* src addr */ 118 "void *", /* dst addr */ 119 "struct ip_fw_args *", /* args */ 120 "struct ip_fw *" /* rule */); 121 122 /* 123 * static variables followed by global ones. 124 * All ipfw global variables are here. 125 */ 126 127 VNET_DEFINE_STATIC(int, fw_deny_unknown_exthdrs); 128 #define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs) 129 130 VNET_DEFINE_STATIC(int, fw_permit_single_frag6) = 1; 131 #define V_fw_permit_single_frag6 VNET(fw_permit_single_frag6) 132 133 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 134 static int default_to_accept = 1; 135 #else 136 static int default_to_accept; 137 #endif 138 139 VNET_DEFINE(int, autoinc_step); 140 VNET_DEFINE(int, fw_one_pass) = 1; 141 142 VNET_DEFINE(unsigned int, fw_tables_max); 143 VNET_DEFINE(unsigned int, fw_tables_sets) = 0; /* Don't use set-aware tables */ 144 /* Use 128 tables by default */ 145 static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT; 146 147 #ifndef LINEAR_SKIPTO 148 static int jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 149 int tablearg, int jump_backwards); 150 #define JUMP(ch, f, num, targ, back) jump_fast(ch, f, num, targ, back) 151 #else 152 static int jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num, 153 int tablearg, int jump_backwards); 154 #define JUMP(ch, f, num, targ, back) jump_linear(ch, f, num, targ, back) 155 #endif 156 157 /* 158 * Each rule belongs to one of 32 different sets (0..31). 159 * The variable set_disable contains one bit per set. 160 * If the bit is set, all rules in the corresponding set 161 * are disabled. Set RESVD_SET(31) is reserved for the default rule 162 * and rules that are not deleted by the flush command, 163 * and CANNOT be disabled. 164 * Rules in set RESVD_SET can only be deleted individually. 165 */ 166 VNET_DEFINE(u_int32_t, set_disable); 167 #define V_set_disable VNET(set_disable) 168 169 VNET_DEFINE(int, fw_verbose); 170 /* counter for ipfw_log(NULL...) */ 171 VNET_DEFINE(u_int64_t, norule_counter); 172 VNET_DEFINE(int, verbose_limit); 173 174 /* layer3_chain contains the list of rules for layer 3 */ 175 VNET_DEFINE(struct ip_fw_chain, layer3_chain); 176 177 /* ipfw_vnet_ready controls when we are open for business */ 178 VNET_DEFINE(int, ipfw_vnet_ready) = 0; 179 180 VNET_DEFINE(int, ipfw_nat_ready) = 0; 181 182 ipfw_nat_t *ipfw_nat_ptr = NULL; 183 struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int); 184 ipfw_nat_cfg_t *ipfw_nat_cfg_ptr; 185 ipfw_nat_cfg_t *ipfw_nat_del_ptr; 186 ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr; 187 ipfw_nat_cfg_t *ipfw_nat_get_log_ptr; 188 189 #ifdef SYSCTL_NODE 190 uint32_t dummy_def = IPFW_DEFAULT_RULE; 191 static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS); 192 static int sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS); 193 194 SYSBEGIN(f3) 195 196 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 197 "Firewall"); 198 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 199 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0, 200 "Only do a single pass through ipfw when using dummynet(4)"); 201 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, 202 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(autoinc_step), 0, 203 "Rule number auto-increment step"); 204 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, 205 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0, 206 "Log matches to ipfw rules"); 207 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, 208 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(verbose_limit), 0, 209 "Set upper limit of matches of ipfw rules logged"); 210 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD, 211 &dummy_def, 0, 212 "The default/max possible rule number."); 213 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_max, 214 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE, 215 0, 0, sysctl_ipfw_table_num, "IU", 216 "Maximum number of concurrently used tables"); 217 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_sets, 218 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE, 219 0, 0, sysctl_ipfw_tables_sets, "IU", 220 "Use per-set namespace for tables"); 221 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN, 222 &default_to_accept, 0, 223 "Make the default rule accept all packets."); 224 TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables); 225 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, 226 CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0, 227 "Number of static rules"); 228 229 #ifdef INET6 230 SYSCTL_DECL(_net_inet6_ip6); 231 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 232 "Firewall"); 233 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs, 234 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE, 235 &VNET_NAME(fw_deny_unknown_exthdrs), 0, 236 "Deny packets with unknown IPv6 Extension Headers"); 237 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6, 238 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE, 239 &VNET_NAME(fw_permit_single_frag6), 0, 240 "Permit single packet IPv6 fragments"); 241 #endif /* INET6 */ 242 243 SYSEND 244 245 #endif /* SYSCTL_NODE */ 246 247 /* 248 * Some macros used in the various matching options. 249 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 250 * Other macros just cast void * into the appropriate type 251 */ 252 #define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 253 #define TCP(p) ((struct tcphdr *)(p)) 254 #define SCTP(p) ((struct sctphdr *)(p)) 255 #define UDP(p) ((struct udphdr *)(p)) 256 #define ICMP(p) ((struct icmphdr *)(p)) 257 #define ICMP6(p) ((struct icmp6_hdr *)(p)) 258 259 static __inline int 260 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 261 { 262 int type = icmp->icmp_type; 263 264 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 265 } 266 267 #define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 268 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 269 270 static int 271 is_icmp_query(struct icmphdr *icmp) 272 { 273 int type = icmp->icmp_type; 274 275 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 276 } 277 #undef TT 278 279 /* 280 * The following checks use two arrays of 8 or 16 bits to store the 281 * bits that we want set or clear, respectively. They are in the 282 * low and high half of cmd->arg1 or cmd->d[0]. 283 * 284 * We scan options and store the bits we find set. We succeed if 285 * 286 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 287 * 288 * The code is sometimes optimized not to store additional variables. 289 */ 290 291 static int 292 flags_match(ipfw_insn *cmd, u_int8_t bits) 293 { 294 u_char want_clear; 295 bits = ~bits; 296 297 if ( ((cmd->arg1 & 0xff) & bits) != 0) 298 return 0; /* some bits we want set were clear */ 299 want_clear = (cmd->arg1 >> 8) & 0xff; 300 if ( (want_clear & bits) != want_clear) 301 return 0; /* some bits we want clear were set */ 302 return 1; 303 } 304 305 static int 306 ipopts_match(struct ip *ip, ipfw_insn *cmd) 307 { 308 int optlen, bits = 0; 309 u_char *cp = (u_char *)(ip + 1); 310 int x = (ip->ip_hl << 2) - sizeof (struct ip); 311 312 for (; x > 0; x -= optlen, cp += optlen) { 313 int opt = cp[IPOPT_OPTVAL]; 314 315 if (opt == IPOPT_EOL) 316 break; 317 if (opt == IPOPT_NOP) 318 optlen = 1; 319 else { 320 optlen = cp[IPOPT_OLEN]; 321 if (optlen <= 0 || optlen > x) 322 return 0; /* invalid or truncated */ 323 } 324 switch (opt) { 325 default: 326 break; 327 328 case IPOPT_LSRR: 329 bits |= IP_FW_IPOPT_LSRR; 330 break; 331 332 case IPOPT_SSRR: 333 bits |= IP_FW_IPOPT_SSRR; 334 break; 335 336 case IPOPT_RR: 337 bits |= IP_FW_IPOPT_RR; 338 break; 339 340 case IPOPT_TS: 341 bits |= IP_FW_IPOPT_TS; 342 break; 343 } 344 } 345 return (flags_match(cmd, bits)); 346 } 347 348 /* 349 * Parse TCP options. The logic copied from tcp_dooptions(). 350 */ 351 static int 352 tcpopts_parse(const struct tcphdr *tcp, uint16_t *mss) 353 { 354 const u_char *cp = (const u_char *)(tcp + 1); 355 int optlen, bits = 0; 356 int cnt = (tcp->th_off << 2) - sizeof(struct tcphdr); 357 358 for (; cnt > 0; cnt -= optlen, cp += optlen) { 359 int opt = cp[0]; 360 if (opt == TCPOPT_EOL) 361 break; 362 if (opt == TCPOPT_NOP) 363 optlen = 1; 364 else { 365 if (cnt < 2) 366 break; 367 optlen = cp[1]; 368 if (optlen < 2 || optlen > cnt) 369 break; 370 } 371 372 switch (opt) { 373 default: 374 break; 375 376 case TCPOPT_MAXSEG: 377 if (optlen != TCPOLEN_MAXSEG) 378 break; 379 bits |= IP_FW_TCPOPT_MSS; 380 if (mss != NULL) 381 *mss = be16dec(cp + 2); 382 break; 383 384 case TCPOPT_WINDOW: 385 if (optlen == TCPOLEN_WINDOW) 386 bits |= IP_FW_TCPOPT_WINDOW; 387 break; 388 389 case TCPOPT_SACK_PERMITTED: 390 if (optlen == TCPOLEN_SACK_PERMITTED) 391 bits |= IP_FW_TCPOPT_SACK; 392 break; 393 394 case TCPOPT_SACK: 395 if (optlen > 2 && (optlen - 2) % TCPOLEN_SACK == 0) 396 bits |= IP_FW_TCPOPT_SACK; 397 break; 398 399 case TCPOPT_TIMESTAMP: 400 if (optlen == TCPOLEN_TIMESTAMP) 401 bits |= IP_FW_TCPOPT_TS; 402 break; 403 } 404 } 405 return (bits); 406 } 407 408 static int 409 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 410 { 411 412 return (flags_match(cmd, tcpopts_parse(tcp, NULL))); 413 } 414 415 static int 416 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain, 417 uint32_t *tablearg) 418 { 419 420 if (ifp == NULL) /* no iface with this packet, match fails */ 421 return (0); 422 423 /* Check by name or by IP address */ 424 if (cmd->name[0] != '\0') { /* match by name */ 425 if (cmd->name[0] == '\1') /* use tablearg to match */ 426 return ipfw_lookup_table(chain, cmd->p.kidx, 0, 427 &ifp->if_index, tablearg); 428 /* Check name */ 429 if (cmd->p.glob) { 430 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 431 return(1); 432 } else { 433 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 434 return(1); 435 } 436 } else { 437 #if !defined(USERSPACE) && defined(__FreeBSD__) /* and OSX too ? */ 438 struct ifaddr *ia; 439 440 NET_EPOCH_ASSERT(); 441 442 CK_STAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 443 if (ia->ifa_addr->sa_family != AF_INET) 444 continue; 445 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 446 (ia->ifa_addr))->sin_addr.s_addr) 447 return (1); /* match */ 448 } 449 #endif /* __FreeBSD__ */ 450 } 451 return(0); /* no match, fail ... */ 452 } 453 454 /* 455 * The verify_path function checks if a route to the src exists and 456 * if it is reachable via ifp (when provided). 457 * 458 * The 'verrevpath' option checks that the interface that an IP packet 459 * arrives on is the same interface that traffic destined for the 460 * packet's source address would be routed out of. 461 * The 'versrcreach' option just checks that the source address is 462 * reachable via any route (except default) in the routing table. 463 * These two are a measure to block forged packets. This is also 464 * commonly known as "anti-spoofing" or Unicast Reverse Path 465 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 466 * is purposely reminiscent of the Cisco IOS command, 467 * 468 * ip verify unicast reverse-path 469 * ip verify unicast source reachable-via any 470 * 471 * which implements the same functionality. But note that the syntax 472 * is misleading, and the check may be performed on all IP packets 473 * whether unicast, multicast, or broadcast. 474 */ 475 static int 476 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib) 477 { 478 #if defined(USERSPACE) || !defined(__FreeBSD__) 479 return 0; 480 #else 481 struct nhop_object *nh; 482 483 nh = fib4_lookup(fib, src, 0, NHR_NONE, 0); 484 if (nh == NULL) 485 return (0); 486 487 /* 488 * If ifp is provided, check for equality with rtentry. 489 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 490 * in order to pass packets injected back by if_simloop(): 491 * routing entry (via lo0) for our own address 492 * may exist, so we need to handle routing assymetry. 493 */ 494 if (ifp != NULL && ifp != nh->nh_aifp) 495 return (0); 496 497 /* if no ifp provided, check if rtentry is not default route */ 498 if (ifp == NULL && (nh->nh_flags & NHF_DEFAULT) != 0) 499 return (0); 500 501 /* or if this is a blackhole/reject route */ 502 if (ifp == NULL && (nh->nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0) 503 return (0); 504 505 /* found valid route */ 506 return 1; 507 #endif /* __FreeBSD__ */ 508 } 509 510 /* 511 * Generate an SCTP packet containing an ABORT chunk. The verification tag 512 * is given by vtag. The T-bit is set in the ABORT chunk if and only if 513 * reflected is not 0. 514 */ 515 516 static struct mbuf * 517 ipfw_send_abort(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t vtag, 518 int reflected) 519 { 520 struct mbuf *m; 521 struct ip *ip; 522 #ifdef INET6 523 struct ip6_hdr *ip6; 524 #endif 525 struct sctphdr *sctp; 526 struct sctp_chunkhdr *chunk; 527 u_int16_t hlen, plen, tlen; 528 529 MGETHDR(m, M_NOWAIT, MT_DATA); 530 if (m == NULL) 531 return (NULL); 532 533 M_SETFIB(m, id->fib); 534 #ifdef MAC 535 if (replyto != NULL) 536 mac_netinet_firewall_reply(replyto, m); 537 else 538 mac_netinet_firewall_send(m); 539 #else 540 (void)replyto; /* don't warn about unused arg */ 541 #endif 542 543 switch (id->addr_type) { 544 case 4: 545 hlen = sizeof(struct ip); 546 break; 547 #ifdef INET6 548 case 6: 549 hlen = sizeof(struct ip6_hdr); 550 break; 551 #endif 552 default: 553 /* XXX: log me?!? */ 554 FREE_PKT(m); 555 return (NULL); 556 } 557 plen = sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr); 558 tlen = hlen + plen; 559 m->m_data += max_linkhdr; 560 m->m_flags |= M_SKIP_FIREWALL; 561 m->m_pkthdr.len = m->m_len = tlen; 562 m->m_pkthdr.rcvif = NULL; 563 bzero(m->m_data, tlen); 564 565 switch (id->addr_type) { 566 case 4: 567 ip = mtod(m, struct ip *); 568 569 ip->ip_v = 4; 570 ip->ip_hl = sizeof(struct ip) >> 2; 571 ip->ip_tos = IPTOS_LOWDELAY; 572 ip->ip_len = htons(tlen); 573 ip->ip_id = htons(0); 574 ip->ip_off = htons(0); 575 ip->ip_ttl = V_ip_defttl; 576 ip->ip_p = IPPROTO_SCTP; 577 ip->ip_sum = 0; 578 ip->ip_src.s_addr = htonl(id->dst_ip); 579 ip->ip_dst.s_addr = htonl(id->src_ip); 580 581 sctp = (struct sctphdr *)(ip + 1); 582 break; 583 #ifdef INET6 584 case 6: 585 ip6 = mtod(m, struct ip6_hdr *); 586 587 ip6->ip6_vfc = IPV6_VERSION; 588 ip6->ip6_plen = htons(plen); 589 ip6->ip6_nxt = IPPROTO_SCTP; 590 ip6->ip6_hlim = IPV6_DEFHLIM; 591 ip6->ip6_src = id->dst_ip6; 592 ip6->ip6_dst = id->src_ip6; 593 594 sctp = (struct sctphdr *)(ip6 + 1); 595 break; 596 #endif 597 } 598 599 sctp->src_port = htons(id->dst_port); 600 sctp->dest_port = htons(id->src_port); 601 sctp->v_tag = htonl(vtag); 602 sctp->checksum = htonl(0); 603 604 chunk = (struct sctp_chunkhdr *)(sctp + 1); 605 chunk->chunk_type = SCTP_ABORT_ASSOCIATION; 606 chunk->chunk_flags = 0; 607 if (reflected != 0) { 608 chunk->chunk_flags |= SCTP_HAD_NO_TCB; 609 } 610 chunk->chunk_length = htons(sizeof(struct sctp_chunkhdr)); 611 612 sctp->checksum = sctp_calculate_cksum(m, hlen); 613 614 return (m); 615 } 616 617 /* 618 * Generate a TCP packet, containing either a RST or a keepalive. 619 * When flags & TH_RST, we are sending a RST packet, because of a 620 * "reset" action matched the packet. 621 * Otherwise we are sending a keepalive, and flags & TH_ 622 * The 'replyto' mbuf is the mbuf being replied to, if any, and is required 623 * so that MAC can label the reply appropriately. 624 */ 625 struct mbuf * 626 ipfw_send_pkt(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t seq, 627 u_int32_t ack, int flags) 628 { 629 struct mbuf *m = NULL; /* stupid compiler */ 630 struct ip *h = NULL; /* stupid compiler */ 631 #ifdef INET6 632 struct ip6_hdr *h6 = NULL; 633 #endif 634 struct tcphdr *th = NULL; 635 int len, dir; 636 637 MGETHDR(m, M_NOWAIT, MT_DATA); 638 if (m == NULL) 639 return (NULL); 640 641 M_SETFIB(m, id->fib); 642 #ifdef MAC 643 if (replyto != NULL) 644 mac_netinet_firewall_reply(replyto, m); 645 else 646 mac_netinet_firewall_send(m); 647 #else 648 (void)replyto; /* don't warn about unused arg */ 649 #endif 650 651 switch (id->addr_type) { 652 case 4: 653 len = sizeof(struct ip) + sizeof(struct tcphdr); 654 break; 655 #ifdef INET6 656 case 6: 657 len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 658 break; 659 #endif 660 default: 661 /* XXX: log me?!? */ 662 FREE_PKT(m); 663 return (NULL); 664 } 665 dir = ((flags & (TH_SYN | TH_RST)) == TH_SYN); 666 667 m->m_data += max_linkhdr; 668 m->m_flags |= M_SKIP_FIREWALL; 669 m->m_pkthdr.len = m->m_len = len; 670 m->m_pkthdr.rcvif = NULL; 671 bzero(m->m_data, len); 672 673 switch (id->addr_type) { 674 case 4: 675 h = mtod(m, struct ip *); 676 677 /* prepare for checksum */ 678 h->ip_p = IPPROTO_TCP; 679 h->ip_len = htons(sizeof(struct tcphdr)); 680 if (dir) { 681 h->ip_src.s_addr = htonl(id->src_ip); 682 h->ip_dst.s_addr = htonl(id->dst_ip); 683 } else { 684 h->ip_src.s_addr = htonl(id->dst_ip); 685 h->ip_dst.s_addr = htonl(id->src_ip); 686 } 687 688 th = (struct tcphdr *)(h + 1); 689 break; 690 #ifdef INET6 691 case 6: 692 h6 = mtod(m, struct ip6_hdr *); 693 694 /* prepare for checksum */ 695 h6->ip6_nxt = IPPROTO_TCP; 696 h6->ip6_plen = htons(sizeof(struct tcphdr)); 697 if (dir) { 698 h6->ip6_src = id->src_ip6; 699 h6->ip6_dst = id->dst_ip6; 700 } else { 701 h6->ip6_src = id->dst_ip6; 702 h6->ip6_dst = id->src_ip6; 703 } 704 705 th = (struct tcphdr *)(h6 + 1); 706 break; 707 #endif 708 } 709 710 if (dir) { 711 th->th_sport = htons(id->src_port); 712 th->th_dport = htons(id->dst_port); 713 } else { 714 th->th_sport = htons(id->dst_port); 715 th->th_dport = htons(id->src_port); 716 } 717 th->th_off = sizeof(struct tcphdr) >> 2; 718 719 if (flags & TH_RST) { 720 if (flags & TH_ACK) { 721 th->th_seq = htonl(ack); 722 th->th_flags = TH_RST; 723 } else { 724 if (flags & TH_SYN) 725 seq++; 726 th->th_ack = htonl(seq); 727 th->th_flags = TH_RST | TH_ACK; 728 } 729 } else { 730 /* 731 * Keepalive - use caller provided sequence numbers 732 */ 733 th->th_seq = htonl(seq); 734 th->th_ack = htonl(ack); 735 th->th_flags = TH_ACK; 736 } 737 738 switch (id->addr_type) { 739 case 4: 740 th->th_sum = in_cksum(m, len); 741 742 /* finish the ip header */ 743 h->ip_v = 4; 744 h->ip_hl = sizeof(*h) >> 2; 745 h->ip_tos = IPTOS_LOWDELAY; 746 h->ip_off = htons(0); 747 h->ip_len = htons(len); 748 h->ip_ttl = V_ip_defttl; 749 h->ip_sum = 0; 750 break; 751 #ifdef INET6 752 case 6: 753 th->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(*h6), 754 sizeof(struct tcphdr)); 755 756 /* finish the ip6 header */ 757 h6->ip6_vfc |= IPV6_VERSION; 758 h6->ip6_hlim = IPV6_DEFHLIM; 759 break; 760 #endif 761 } 762 763 return (m); 764 } 765 766 #ifdef INET6 767 /* 768 * ipv6 specific rules here... 769 */ 770 static __inline int 771 icmp6type_match(int type, ipfw_insn_u32 *cmd) 772 { 773 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 774 } 775 776 static int 777 flow6id_match(int curr_flow, ipfw_insn_u32 *cmd) 778 { 779 int i; 780 for (i=0; i <= cmd->o.arg1; ++i) 781 if (curr_flow == cmd->d[i]) 782 return 1; 783 return 0; 784 } 785 786 /* support for IP6_*_ME opcodes */ 787 static const struct in6_addr lla_mask = {{{ 788 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 789 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff 790 }}}; 791 792 static int 793 ipfw_localip6(struct in6_addr *in6) 794 { 795 struct rm_priotracker in6_ifa_tracker; 796 struct in6_ifaddr *ia; 797 798 if (IN6_IS_ADDR_MULTICAST(in6)) 799 return (0); 800 801 if (!IN6_IS_ADDR_LINKLOCAL(in6)) 802 return (in6_localip(in6)); 803 804 IN6_IFADDR_RLOCK(&in6_ifa_tracker); 805 CK_STAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) { 806 if (!IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) 807 continue; 808 if (IN6_ARE_MASKED_ADDR_EQUAL(&ia->ia_addr.sin6_addr, 809 in6, &lla_mask)) { 810 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 811 return (1); 812 } 813 } 814 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 815 return (0); 816 } 817 818 static int 819 verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib) 820 { 821 struct nhop_object *nh; 822 823 if (IN6_IS_SCOPE_LINKLOCAL(src)) 824 return (1); 825 826 nh = fib6_lookup(fib, src, 0, NHR_NONE, 0); 827 if (nh == NULL) 828 return (0); 829 830 /* If ifp is provided, check for equality with route table. */ 831 if (ifp != NULL && ifp != nh->nh_aifp) 832 return (0); 833 834 /* if no ifp provided, check if rtentry is not default route */ 835 if (ifp == NULL && (nh->nh_flags & NHF_DEFAULT) != 0) 836 return (0); 837 838 /* or if this is a blackhole/reject route */ 839 if (ifp == NULL && (nh->nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0) 840 return (0); 841 842 /* found valid route */ 843 return 1; 844 } 845 846 static int 847 is_icmp6_query(int icmp6_type) 848 { 849 if ((icmp6_type <= ICMP6_MAXTYPE) && 850 (icmp6_type == ICMP6_ECHO_REQUEST || 851 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 852 icmp6_type == ICMP6_WRUREQUEST || 853 icmp6_type == ICMP6_FQDN_QUERY || 854 icmp6_type == ICMP6_NI_QUERY)) 855 return (1); 856 857 return (0); 858 } 859 860 static int 861 map_icmp_unreach(int code) 862 { 863 864 /* RFC 7915 p4.2 */ 865 switch (code) { 866 case ICMP_UNREACH_NET: 867 case ICMP_UNREACH_HOST: 868 case ICMP_UNREACH_SRCFAIL: 869 case ICMP_UNREACH_NET_UNKNOWN: 870 case ICMP_UNREACH_HOST_UNKNOWN: 871 case ICMP_UNREACH_TOSNET: 872 case ICMP_UNREACH_TOSHOST: 873 return (ICMP6_DST_UNREACH_NOROUTE); 874 case ICMP_UNREACH_PORT: 875 return (ICMP6_DST_UNREACH_NOPORT); 876 default: 877 /* 878 * Map the rest of codes into admit prohibited. 879 * XXX: unreach proto should be mapped into ICMPv6 880 * parameter problem, but we use only unreach type. 881 */ 882 return (ICMP6_DST_UNREACH_ADMIN); 883 } 884 } 885 886 static void 887 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 888 { 889 struct mbuf *m; 890 891 m = args->m; 892 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 893 struct tcphdr *tcp; 894 tcp = (struct tcphdr *)((char *)ip6 + hlen); 895 896 if ((tcp->th_flags & TH_RST) == 0) { 897 struct mbuf *m0; 898 m0 = ipfw_send_pkt(args->m, &(args->f_id), 899 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 900 tcp->th_flags | TH_RST); 901 if (m0 != NULL) 902 ip6_output(m0, NULL, NULL, 0, NULL, NULL, 903 NULL); 904 } 905 FREE_PKT(m); 906 } else if (code == ICMP6_UNREACH_ABORT && 907 args->f_id.proto == IPPROTO_SCTP) { 908 struct mbuf *m0; 909 struct sctphdr *sctp; 910 u_int32_t v_tag; 911 int reflected; 912 913 sctp = (struct sctphdr *)((char *)ip6 + hlen); 914 reflected = 1; 915 v_tag = ntohl(sctp->v_tag); 916 /* Investigate the first chunk header if available */ 917 if (m->m_len >= hlen + sizeof(struct sctphdr) + 918 sizeof(struct sctp_chunkhdr)) { 919 struct sctp_chunkhdr *chunk; 920 921 chunk = (struct sctp_chunkhdr *)(sctp + 1); 922 switch (chunk->chunk_type) { 923 case SCTP_INITIATION: 924 /* 925 * Packets containing an INIT chunk MUST have 926 * a zero v-tag. 927 */ 928 if (v_tag != 0) { 929 v_tag = 0; 930 break; 931 } 932 /* INIT chunk MUST NOT be bundled */ 933 if (m->m_pkthdr.len > 934 hlen + sizeof(struct sctphdr) + 935 ntohs(chunk->chunk_length) + 3) { 936 break; 937 } 938 /* Use the initiate tag if available */ 939 if ((m->m_len >= hlen + sizeof(struct sctphdr) + 940 sizeof(struct sctp_chunkhdr) + 941 offsetof(struct sctp_init, a_rwnd))) { 942 struct sctp_init *init; 943 944 init = (struct sctp_init *)(chunk + 1); 945 v_tag = ntohl(init->initiate_tag); 946 reflected = 0; 947 } 948 break; 949 case SCTP_ABORT_ASSOCIATION: 950 /* 951 * If the packet contains an ABORT chunk, don't 952 * reply. 953 * XXX: We should search through all chunks, 954 * but do not do that to avoid attacks. 955 */ 956 v_tag = 0; 957 break; 958 } 959 } 960 if (v_tag == 0) { 961 m0 = NULL; 962 } else { 963 m0 = ipfw_send_abort(args->m, &(args->f_id), v_tag, 964 reflected); 965 } 966 if (m0 != NULL) 967 ip6_output(m0, NULL, NULL, 0, NULL, NULL, NULL); 968 FREE_PKT(m); 969 } else if (code != ICMP6_UNREACH_RST && code != ICMP6_UNREACH_ABORT) { 970 /* Send an ICMPv6 unreach. */ 971 #if 0 972 /* 973 * Unlike above, the mbufs need to line up with the ip6 hdr, 974 * as the contents are read. We need to m_adj() the 975 * needed amount. 976 * The mbuf will however be thrown away so we can adjust it. 977 * Remember we did an m_pullup on it already so we 978 * can make some assumptions about contiguousness. 979 */ 980 if (args->L3offset) 981 m_adj(m, args->L3offset); 982 #endif 983 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 984 } else 985 FREE_PKT(m); 986 987 args->m = NULL; 988 } 989 990 #endif /* INET6 */ 991 992 /* 993 * sends a reject message, consuming the mbuf passed as an argument. 994 */ 995 static void 996 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip) 997 { 998 999 #if 0 1000 /* XXX When ip is not guaranteed to be at mtod() we will 1001 * need to account for this */ 1002 * The mbuf will however be thrown away so we can adjust it. 1003 * Remember we did an m_pullup on it already so we 1004 * can make some assumptions about contiguousness. 1005 */ 1006 if (args->L3offset) 1007 m_adj(m, args->L3offset); 1008 #endif 1009 if (code != ICMP_REJECT_RST && code != ICMP_REJECT_ABORT) { 1010 /* Send an ICMP unreach */ 1011 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 1012 } else if (code == ICMP_REJECT_RST && args->f_id.proto == IPPROTO_TCP) { 1013 struct tcphdr *const tcp = 1014 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 1015 if ( (tcp->th_flags & TH_RST) == 0) { 1016 struct mbuf *m; 1017 m = ipfw_send_pkt(args->m, &(args->f_id), 1018 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 1019 tcp->th_flags | TH_RST); 1020 if (m != NULL) 1021 ip_output(m, NULL, NULL, 0, NULL, NULL); 1022 } 1023 FREE_PKT(args->m); 1024 } else if (code == ICMP_REJECT_ABORT && 1025 args->f_id.proto == IPPROTO_SCTP) { 1026 struct mbuf *m; 1027 struct sctphdr *sctp; 1028 struct sctp_chunkhdr *chunk; 1029 struct sctp_init *init; 1030 u_int32_t v_tag; 1031 int reflected; 1032 1033 sctp = L3HDR(struct sctphdr, mtod(args->m, struct ip *)); 1034 reflected = 1; 1035 v_tag = ntohl(sctp->v_tag); 1036 if (iplen >= (ip->ip_hl << 2) + sizeof(struct sctphdr) + 1037 sizeof(struct sctp_chunkhdr)) { 1038 /* Look at the first chunk header if available */ 1039 chunk = (struct sctp_chunkhdr *)(sctp + 1); 1040 switch (chunk->chunk_type) { 1041 case SCTP_INITIATION: 1042 /* 1043 * Packets containing an INIT chunk MUST have 1044 * a zero v-tag. 1045 */ 1046 if (v_tag != 0) { 1047 v_tag = 0; 1048 break; 1049 } 1050 /* INIT chunk MUST NOT be bundled */ 1051 if (iplen > 1052 (ip->ip_hl << 2) + sizeof(struct sctphdr) + 1053 ntohs(chunk->chunk_length) + 3) { 1054 break; 1055 } 1056 /* Use the initiate tag if available */ 1057 if ((iplen >= (ip->ip_hl << 2) + 1058 sizeof(struct sctphdr) + 1059 sizeof(struct sctp_chunkhdr) + 1060 offsetof(struct sctp_init, a_rwnd))) { 1061 init = (struct sctp_init *)(chunk + 1); 1062 v_tag = ntohl(init->initiate_tag); 1063 reflected = 0; 1064 } 1065 break; 1066 case SCTP_ABORT_ASSOCIATION: 1067 /* 1068 * If the packet contains an ABORT chunk, don't 1069 * reply. 1070 * XXX: We should search through all chunks, 1071 * but do not do that to avoid attacks. 1072 */ 1073 v_tag = 0; 1074 break; 1075 } 1076 } 1077 if (v_tag == 0) { 1078 m = NULL; 1079 } else { 1080 m = ipfw_send_abort(args->m, &(args->f_id), v_tag, 1081 reflected); 1082 } 1083 if (m != NULL) 1084 ip_output(m, NULL, NULL, 0, NULL, NULL); 1085 FREE_PKT(args->m); 1086 } else 1087 FREE_PKT(args->m); 1088 args->m = NULL; 1089 } 1090 1091 /* 1092 * Support for uid/gid/jail lookup. These tests are expensive 1093 * (because we may need to look into the list of active sockets) 1094 * so we cache the results. ugid_lookupp is 0 if we have not 1095 * yet done a lookup, 1 if we succeeded, and -1 if we tried 1096 * and failed. The function always returns the match value. 1097 * We could actually spare the variable and use *uc, setting 1098 * it to '(void *)check_uidgid if we have no info, NULL if 1099 * we tried and failed, or any other value if successful. 1100 */ 1101 static int 1102 check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp, 1103 struct ucred **uc) 1104 { 1105 #if defined(USERSPACE) 1106 return 0; // not supported in userspace 1107 #else 1108 #ifndef __FreeBSD__ 1109 /* XXX */ 1110 return cred_check(insn, proto, oif, 1111 dst_ip, dst_port, src_ip, src_port, 1112 (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb); 1113 #else /* FreeBSD */ 1114 struct in_addr src_ip, dst_ip; 1115 struct inpcbinfo *pi; 1116 struct ipfw_flow_id *id; 1117 struct inpcb *pcb, *inp; 1118 int lookupflags; 1119 int match; 1120 1121 id = &args->f_id; 1122 inp = args->inp; 1123 1124 /* 1125 * Check to see if the UDP or TCP stack supplied us with 1126 * the PCB. If so, rather then holding a lock and looking 1127 * up the PCB, we can use the one that was supplied. 1128 */ 1129 if (inp && *ugid_lookupp == 0) { 1130 INP_LOCK_ASSERT(inp); 1131 if (inp->inp_socket != NULL) { 1132 *uc = crhold(inp->inp_cred); 1133 *ugid_lookupp = 1; 1134 } else 1135 *ugid_lookupp = -1; 1136 } 1137 /* 1138 * If we have already been here and the packet has no 1139 * PCB entry associated with it, then we can safely 1140 * assume that this is a no match. 1141 */ 1142 if (*ugid_lookupp == -1) 1143 return (0); 1144 if (id->proto == IPPROTO_TCP) { 1145 lookupflags = 0; 1146 pi = &V_tcbinfo; 1147 } else if (id->proto == IPPROTO_UDP) { 1148 lookupflags = INPLOOKUP_WILDCARD; 1149 pi = &V_udbinfo; 1150 } else if (id->proto == IPPROTO_UDPLITE) { 1151 lookupflags = INPLOOKUP_WILDCARD; 1152 pi = &V_ulitecbinfo; 1153 } else 1154 return 0; 1155 lookupflags |= INPLOOKUP_RLOCKPCB; 1156 match = 0; 1157 if (*ugid_lookupp == 0) { 1158 if (id->addr_type == 6) { 1159 #ifdef INET6 1160 if (args->flags & IPFW_ARGS_IN) 1161 pcb = in6_pcblookup_mbuf(pi, 1162 &id->src_ip6, htons(id->src_port), 1163 &id->dst_ip6, htons(id->dst_port), 1164 lookupflags, NULL, args->m); 1165 else 1166 pcb = in6_pcblookup_mbuf(pi, 1167 &id->dst_ip6, htons(id->dst_port), 1168 &id->src_ip6, htons(id->src_port), 1169 lookupflags, args->ifp, args->m); 1170 #else 1171 *ugid_lookupp = -1; 1172 return (0); 1173 #endif 1174 } else { 1175 src_ip.s_addr = htonl(id->src_ip); 1176 dst_ip.s_addr = htonl(id->dst_ip); 1177 if (args->flags & IPFW_ARGS_IN) 1178 pcb = in_pcblookup_mbuf(pi, 1179 src_ip, htons(id->src_port), 1180 dst_ip, htons(id->dst_port), 1181 lookupflags, NULL, args->m); 1182 else 1183 pcb = in_pcblookup_mbuf(pi, 1184 dst_ip, htons(id->dst_port), 1185 src_ip, htons(id->src_port), 1186 lookupflags, args->ifp, args->m); 1187 } 1188 if (pcb != NULL) { 1189 INP_RLOCK_ASSERT(pcb); 1190 *uc = crhold(pcb->inp_cred); 1191 *ugid_lookupp = 1; 1192 INP_RUNLOCK(pcb); 1193 } 1194 if (*ugid_lookupp == 0) { 1195 /* 1196 * We tried and failed, set the variable to -1 1197 * so we will not try again on this packet. 1198 */ 1199 *ugid_lookupp = -1; 1200 return (0); 1201 } 1202 } 1203 if (insn->o.opcode == O_UID) 1204 match = ((*uc)->cr_uid == (uid_t)insn->d[0]); 1205 else if (insn->o.opcode == O_GID) 1206 match = groupmember((gid_t)insn->d[0], *uc); 1207 else if (insn->o.opcode == O_JAIL) 1208 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]); 1209 return (match); 1210 #endif /* __FreeBSD__ */ 1211 #endif /* not supported in userspace */ 1212 } 1213 1214 /* 1215 * Helper function to set args with info on the rule after the matching 1216 * one. slot is precise, whereas we guess rule_id as they are 1217 * assigned sequentially. 1218 */ 1219 static inline void 1220 set_match(struct ip_fw_args *args, int slot, 1221 struct ip_fw_chain *chain) 1222 { 1223 args->rule.chain_id = chain->id; 1224 args->rule.slot = slot + 1; /* we use 0 as a marker */ 1225 args->rule.rule_id = 1 + chain->map[slot]->id; 1226 args->rule.rulenum = chain->map[slot]->rulenum; 1227 args->flags |= IPFW_ARGS_REF; 1228 } 1229 1230 #ifndef LINEAR_SKIPTO 1231 /* 1232 * Helper function to enable cached rule lookups using 1233 * cached_id and cached_pos fields in ipfw rule. 1234 */ 1235 static int 1236 jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 1237 int tablearg, int jump_backwards) 1238 { 1239 int f_pos; 1240 1241 /* If possible use cached f_pos (in f->cached_pos), 1242 * whose version is written in f->cached_id 1243 * (horrible hacks to avoid changing the ABI). 1244 */ 1245 if (num != IP_FW_TARG && f->cached_id == chain->id) 1246 f_pos = f->cached_pos; 1247 else { 1248 int i = IP_FW_ARG_TABLEARG(chain, num, skipto); 1249 /* make sure we do not jump backward */ 1250 if (jump_backwards == 0 && i <= f->rulenum) 1251 i = f->rulenum + 1; 1252 if (chain->idxmap != NULL) 1253 f_pos = chain->idxmap[i]; 1254 else 1255 f_pos = ipfw_find_rule(chain, i, 0); 1256 /* update the cache */ 1257 if (num != IP_FW_TARG) { 1258 f->cached_id = chain->id; 1259 f->cached_pos = f_pos; 1260 } 1261 } 1262 1263 return (f_pos); 1264 } 1265 #else 1266 /* 1267 * Helper function to enable real fast rule lookups. 1268 */ 1269 static int 1270 jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num, 1271 int tablearg, int jump_backwards) 1272 { 1273 int f_pos; 1274 1275 num = IP_FW_ARG_TABLEARG(chain, num, skipto); 1276 /* make sure we do not jump backward */ 1277 if (jump_backwards == 0 && num <= f->rulenum) 1278 num = f->rulenum + 1; 1279 f_pos = chain->idxmap[num]; 1280 1281 return (f_pos); 1282 } 1283 #endif 1284 1285 #define TARG(k, f) IP_FW_ARG_TABLEARG(chain, k, f) 1286 /* 1287 * The main check routine for the firewall. 1288 * 1289 * All arguments are in args so we can modify them and return them 1290 * back to the caller. 1291 * 1292 * Parameters: 1293 * 1294 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 1295 * Starts with the IP header. 1296 * args->L3offset Number of bytes bypassed if we came from L2. 1297 * e.g. often sizeof(eh) ** NOTYET ** 1298 * args->ifp Incoming or outgoing interface. 1299 * args->divert_rule (in/out) 1300 * Skip up to the first rule past this rule number; 1301 * upon return, non-zero port number for divert or tee. 1302 * 1303 * args->rule Pointer to the last matching rule (in/out) 1304 * args->next_hop Socket we are forwarding to (out). 1305 * args->next_hop6 IPv6 next hop we are forwarding to (out). 1306 * args->f_id Addresses grabbed from the packet (out) 1307 * args->rule.info a cookie depending on rule action 1308 * 1309 * Return value: 1310 * 1311 * IP_FW_PASS the packet must be accepted 1312 * IP_FW_DENY the packet must be dropped 1313 * IP_FW_DIVERT divert packet, port in m_tag 1314 * IP_FW_TEE tee packet, port in m_tag 1315 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 1316 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 1317 * args->rule contains the matching rule, 1318 * args->rule.info has additional information. 1319 * 1320 */ 1321 int 1322 ipfw_chk(struct ip_fw_args *args) 1323 { 1324 1325 /* 1326 * Local variables holding state while processing a packet: 1327 * 1328 * IMPORTANT NOTE: to speed up the processing of rules, there 1329 * are some assumption on the values of the variables, which 1330 * are documented here. Should you change them, please check 1331 * the implementation of the various instructions to make sure 1332 * that they still work. 1333 * 1334 * m | args->m Pointer to the mbuf, as received from the caller. 1335 * It may change if ipfw_chk() does an m_pullup, or if it 1336 * consumes the packet because it calls send_reject(). 1337 * XXX This has to change, so that ipfw_chk() never modifies 1338 * or consumes the buffer. 1339 * OR 1340 * args->mem Pointer to contigous memory chunk. 1341 * ip Is the beginning of the ip(4 or 6) header. 1342 * eh Ethernet header in case if input is Layer2. 1343 */ 1344 struct mbuf *m; 1345 struct ip *ip; 1346 struct ether_header *eh; 1347 1348 /* 1349 * For rules which contain uid/gid or jail constraints, cache 1350 * a copy of the users credentials after the pcb lookup has been 1351 * executed. This will speed up the processing of rules with 1352 * these types of constraints, as well as decrease contention 1353 * on pcb related locks. 1354 */ 1355 #ifndef __FreeBSD__ 1356 struct bsd_ucred ucred_cache; 1357 #else 1358 struct ucred *ucred_cache = NULL; 1359 #endif 1360 int ucred_lookup = 0; 1361 int f_pos = 0; /* index of current rule in the array */ 1362 int retval = 0; 1363 struct ifnet *oif, *iif; 1364 1365 /* 1366 * hlen The length of the IP header. 1367 */ 1368 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 1369 1370 /* 1371 * offset The offset of a fragment. offset != 0 means that 1372 * we have a fragment at this offset of an IPv4 packet. 1373 * offset == 0 means that (if this is an IPv4 packet) 1374 * this is the first or only fragment. 1375 * For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header 1376 * or there is a single packet fragment (fragment header added 1377 * without needed). We will treat a single packet fragment as if 1378 * there was no fragment header (or log/block depending on the 1379 * V_fw_permit_single_frag6 sysctl setting). 1380 */ 1381 u_short offset = 0; 1382 u_short ip6f_mf = 0; 1383 1384 /* 1385 * Local copies of addresses. They are only valid if we have 1386 * an IP packet. 1387 * 1388 * proto The protocol. Set to 0 for non-ip packets, 1389 * or to the protocol read from the packet otherwise. 1390 * proto != 0 means that we have an IPv4 packet. 1391 * 1392 * src_port, dst_port port numbers, in HOST format. Only 1393 * valid for TCP and UDP packets. 1394 * 1395 * src_ip, dst_ip ip addresses, in NETWORK format. 1396 * Only valid for IPv4 packets. 1397 */ 1398 uint8_t proto; 1399 uint16_t src_port, dst_port; /* NOTE: host format */ 1400 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 1401 int iplen = 0; 1402 int pktlen; 1403 1404 struct ipfw_dyn_info dyn_info; 1405 struct ip_fw *q = NULL; 1406 struct ip_fw_chain *chain = &V_layer3_chain; 1407 1408 /* 1409 * We store in ulp a pointer to the upper layer protocol header. 1410 * In the ipv4 case this is easy to determine from the header, 1411 * but for ipv6 we might have some additional headers in the middle. 1412 * ulp is NULL if not found. 1413 */ 1414 void *ulp = NULL; /* upper layer protocol pointer. */ 1415 1416 /* XXX ipv6 variables */ 1417 int is_ipv6 = 0; 1418 uint8_t icmp6_type = 0; 1419 uint16_t ext_hd = 0; /* bits vector for extension header filtering */ 1420 /* end of ipv6 variables */ 1421 1422 int is_ipv4 = 0; 1423 1424 int done = 0; /* flag to exit the outer loop */ 1425 IPFW_RLOCK_TRACKER; 1426 bool mem; 1427 1428 if ((mem = (args->flags & IPFW_ARGS_LENMASK))) { 1429 if (args->flags & IPFW_ARGS_ETHER) { 1430 eh = (struct ether_header *)args->mem; 1431 if (eh->ether_type == htons(ETHERTYPE_VLAN)) 1432 ip = (struct ip *) 1433 ((struct ether_vlan_header *)eh + 1); 1434 else 1435 ip = (struct ip *)(eh + 1); 1436 } else { 1437 eh = NULL; 1438 ip = (struct ip *)args->mem; 1439 } 1440 pktlen = IPFW_ARGS_LENGTH(args->flags); 1441 args->f_id.fib = args->ifp->if_fib; /* best guess */ 1442 } else { 1443 m = args->m; 1444 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready)) 1445 return (IP_FW_PASS); /* accept */ 1446 if (args->flags & IPFW_ARGS_ETHER) { 1447 /* We need some amount of data to be contiguous. */ 1448 if (m->m_len < min(m->m_pkthdr.len, max_protohdr) && 1449 (args->m = m = m_pullup(m, min(m->m_pkthdr.len, 1450 max_protohdr))) == NULL) 1451 goto pullup_failed; 1452 eh = mtod(m, struct ether_header *); 1453 ip = (struct ip *)(eh + 1); 1454 } else { 1455 eh = NULL; 1456 ip = mtod(m, struct ip *); 1457 } 1458 pktlen = m->m_pkthdr.len; 1459 args->f_id.fib = M_GETFIB(m); /* mbuf not altered */ 1460 } 1461 1462 dst_ip.s_addr = 0; /* make sure it is initialized */ 1463 src_ip.s_addr = 0; /* make sure it is initialized */ 1464 src_port = dst_port = 0; 1465 1466 DYN_INFO_INIT(&dyn_info); 1467 /* 1468 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 1469 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 1470 * pointer might become stale after other pullups (but we never use it 1471 * this way). 1472 */ 1473 #define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T)) 1474 #define EHLEN (eh != NULL ? ((char *)ip - (char *)eh) : 0) 1475 #define _PULLUP_LOCKED(_len, p, T, unlock) \ 1476 do { \ 1477 int x = (_len) + T + EHLEN; \ 1478 if (mem) { \ 1479 if (__predict_false(pktlen < x)) { \ 1480 unlock; \ 1481 goto pullup_failed; \ 1482 } \ 1483 p = (char *)args->mem + (_len) + EHLEN; \ 1484 } else { \ 1485 if (__predict_false((m)->m_len < x)) { \ 1486 args->m = m = m_pullup(m, x); \ 1487 if (m == NULL) { \ 1488 unlock; \ 1489 goto pullup_failed; \ 1490 } \ 1491 } \ 1492 p = mtod(m, char *) + (_len) + EHLEN; \ 1493 } \ 1494 } while (0) 1495 1496 #define PULLUP_LEN(_len, p, T) _PULLUP_LOCKED(_len, p, T, ) 1497 #define PULLUP_LEN_LOCKED(_len, p, T) \ 1498 _PULLUP_LOCKED(_len, p, T, IPFW_PF_RUNLOCK(chain)); \ 1499 UPDATE_POINTERS() 1500 /* 1501 * In case pointers got stale after pullups, update them. 1502 */ 1503 #define UPDATE_POINTERS() \ 1504 do { \ 1505 if (!mem) { \ 1506 if (eh != NULL) { \ 1507 eh = mtod(m, struct ether_header *); \ 1508 ip = (struct ip *)(eh + 1); \ 1509 } else \ 1510 ip = mtod(m, struct ip *); \ 1511 args->m = m; \ 1512 } \ 1513 } while (0) 1514 1515 /* Identify IP packets and fill up variables. */ 1516 if (pktlen >= sizeof(struct ip6_hdr) && 1517 (eh == NULL || eh->ether_type == htons(ETHERTYPE_IPV6)) && 1518 ip->ip_v == 6) { 1519 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 1520 1521 is_ipv6 = 1; 1522 args->flags |= IPFW_ARGS_IP6; 1523 hlen = sizeof(struct ip6_hdr); 1524 proto = ip6->ip6_nxt; 1525 /* Search extension headers to find upper layer protocols */ 1526 while (ulp == NULL && offset == 0) { 1527 switch (proto) { 1528 case IPPROTO_ICMPV6: 1529 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 1530 icmp6_type = ICMP6(ulp)->icmp6_type; 1531 break; 1532 1533 case IPPROTO_TCP: 1534 PULLUP_TO(hlen, ulp, struct tcphdr); 1535 dst_port = TCP(ulp)->th_dport; 1536 src_port = TCP(ulp)->th_sport; 1537 /* save flags for dynamic rules */ 1538 args->f_id._flags = TCP(ulp)->th_flags; 1539 break; 1540 1541 case IPPROTO_SCTP: 1542 if (pktlen >= hlen + sizeof(struct sctphdr) + 1543 sizeof(struct sctp_chunkhdr) + 1544 offsetof(struct sctp_init, a_rwnd)) 1545 PULLUP_LEN(hlen, ulp, 1546 sizeof(struct sctphdr) + 1547 sizeof(struct sctp_chunkhdr) + 1548 offsetof(struct sctp_init, a_rwnd)); 1549 else if (pktlen >= hlen + sizeof(struct sctphdr)) 1550 PULLUP_LEN(hlen, ulp, pktlen - hlen); 1551 else 1552 PULLUP_LEN(hlen, ulp, 1553 sizeof(struct sctphdr)); 1554 src_port = SCTP(ulp)->src_port; 1555 dst_port = SCTP(ulp)->dest_port; 1556 break; 1557 1558 case IPPROTO_UDP: 1559 case IPPROTO_UDPLITE: 1560 PULLUP_TO(hlen, ulp, struct udphdr); 1561 dst_port = UDP(ulp)->uh_dport; 1562 src_port = UDP(ulp)->uh_sport; 1563 break; 1564 1565 case IPPROTO_HOPOPTS: /* RFC 2460 */ 1566 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1567 ext_hd |= EXT_HOPOPTS; 1568 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1569 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1570 ulp = NULL; 1571 break; 1572 1573 case IPPROTO_ROUTING: /* RFC 2460 */ 1574 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 1575 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 1576 case 0: 1577 ext_hd |= EXT_RTHDR0; 1578 break; 1579 case 2: 1580 ext_hd |= EXT_RTHDR2; 1581 break; 1582 default: 1583 if (V_fw_verbose) 1584 printf("IPFW2: IPV6 - Unknown " 1585 "Routing Header type(%d)\n", 1586 ((struct ip6_rthdr *) 1587 ulp)->ip6r_type); 1588 if (V_fw_deny_unknown_exthdrs) 1589 return (IP_FW_DENY); 1590 break; 1591 } 1592 ext_hd |= EXT_ROUTING; 1593 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 1594 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 1595 ulp = NULL; 1596 break; 1597 1598 case IPPROTO_FRAGMENT: /* RFC 2460 */ 1599 PULLUP_TO(hlen, ulp, struct ip6_frag); 1600 ext_hd |= EXT_FRAGMENT; 1601 hlen += sizeof (struct ip6_frag); 1602 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 1603 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 1604 IP6F_OFF_MASK; 1605 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg & 1606 IP6F_MORE_FRAG; 1607 if (V_fw_permit_single_frag6 == 0 && 1608 offset == 0 && ip6f_mf == 0) { 1609 if (V_fw_verbose) 1610 printf("IPFW2: IPV6 - Invalid " 1611 "Fragment Header\n"); 1612 if (V_fw_deny_unknown_exthdrs) 1613 return (IP_FW_DENY); 1614 break; 1615 } 1616 args->f_id.extra = 1617 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 1618 ulp = NULL; 1619 break; 1620 1621 case IPPROTO_DSTOPTS: /* RFC 2460 */ 1622 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1623 ext_hd |= EXT_DSTOPTS; 1624 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1625 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1626 ulp = NULL; 1627 break; 1628 1629 case IPPROTO_AH: /* RFC 2402 */ 1630 PULLUP_TO(hlen, ulp, struct ip6_ext); 1631 ext_hd |= EXT_AH; 1632 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 1633 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 1634 ulp = NULL; 1635 break; 1636 1637 case IPPROTO_ESP: /* RFC 2406 */ 1638 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 1639 /* Anything past Seq# is variable length and 1640 * data past this ext. header is encrypted. */ 1641 ext_hd |= EXT_ESP; 1642 break; 1643 1644 case IPPROTO_NONE: /* RFC 2460 */ 1645 /* 1646 * Packet ends here, and IPv6 header has 1647 * already been pulled up. If ip6e_len!=0 1648 * then octets must be ignored. 1649 */ 1650 ulp = ip; /* non-NULL to get out of loop. */ 1651 break; 1652 1653 case IPPROTO_OSPFIGP: 1654 /* XXX OSPF header check? */ 1655 PULLUP_TO(hlen, ulp, struct ip6_ext); 1656 break; 1657 1658 case IPPROTO_PIM: 1659 /* XXX PIM header check? */ 1660 PULLUP_TO(hlen, ulp, struct pim); 1661 break; 1662 1663 case IPPROTO_GRE: /* RFC 1701 */ 1664 /* XXX GRE header check? */ 1665 PULLUP_TO(hlen, ulp, struct grehdr); 1666 break; 1667 1668 case IPPROTO_CARP: 1669 PULLUP_TO(hlen, ulp, offsetof( 1670 struct carp_header, carp_counter)); 1671 if (CARP_ADVERTISEMENT != 1672 ((struct carp_header *)ulp)->carp_type) 1673 return (IP_FW_DENY); 1674 break; 1675 1676 case IPPROTO_IPV6: /* RFC 2893 */ 1677 PULLUP_TO(hlen, ulp, struct ip6_hdr); 1678 break; 1679 1680 case IPPROTO_IPV4: /* RFC 2893 */ 1681 PULLUP_TO(hlen, ulp, struct ip); 1682 break; 1683 1684 default: 1685 if (V_fw_verbose) 1686 printf("IPFW2: IPV6 - Unknown " 1687 "Extension Header(%d), ext_hd=%x\n", 1688 proto, ext_hd); 1689 if (V_fw_deny_unknown_exthdrs) 1690 return (IP_FW_DENY); 1691 PULLUP_TO(hlen, ulp, struct ip6_ext); 1692 break; 1693 } /*switch */ 1694 } 1695 UPDATE_POINTERS(); 1696 ip6 = (struct ip6_hdr *)ip; 1697 args->f_id.addr_type = 6; 1698 args->f_id.src_ip6 = ip6->ip6_src; 1699 args->f_id.dst_ip6 = ip6->ip6_dst; 1700 args->f_id.flow_id6 = ntohl(ip6->ip6_flow); 1701 iplen = ntohs(ip6->ip6_plen) + sizeof(*ip6); 1702 } else if (pktlen >= sizeof(struct ip) && 1703 (eh == NULL || eh->ether_type == htons(ETHERTYPE_IP)) && 1704 ip->ip_v == 4) { 1705 is_ipv4 = 1; 1706 args->flags |= IPFW_ARGS_IP4; 1707 hlen = ip->ip_hl << 2; 1708 /* 1709 * Collect parameters into local variables for faster 1710 * matching. 1711 */ 1712 proto = ip->ip_p; 1713 src_ip = ip->ip_src; 1714 dst_ip = ip->ip_dst; 1715 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1716 iplen = ntohs(ip->ip_len); 1717 1718 if (offset == 0) { 1719 switch (proto) { 1720 case IPPROTO_TCP: 1721 PULLUP_TO(hlen, ulp, struct tcphdr); 1722 dst_port = TCP(ulp)->th_dport; 1723 src_port = TCP(ulp)->th_sport; 1724 /* save flags for dynamic rules */ 1725 args->f_id._flags = TCP(ulp)->th_flags; 1726 break; 1727 1728 case IPPROTO_SCTP: 1729 if (pktlen >= hlen + sizeof(struct sctphdr) + 1730 sizeof(struct sctp_chunkhdr) + 1731 offsetof(struct sctp_init, a_rwnd)) 1732 PULLUP_LEN(hlen, ulp, 1733 sizeof(struct sctphdr) + 1734 sizeof(struct sctp_chunkhdr) + 1735 offsetof(struct sctp_init, a_rwnd)); 1736 else if (pktlen >= hlen + sizeof(struct sctphdr)) 1737 PULLUP_LEN(hlen, ulp, pktlen - hlen); 1738 else 1739 PULLUP_LEN(hlen, ulp, 1740 sizeof(struct sctphdr)); 1741 src_port = SCTP(ulp)->src_port; 1742 dst_port = SCTP(ulp)->dest_port; 1743 break; 1744 1745 case IPPROTO_UDP: 1746 case IPPROTO_UDPLITE: 1747 PULLUP_TO(hlen, ulp, struct udphdr); 1748 dst_port = UDP(ulp)->uh_dport; 1749 src_port = UDP(ulp)->uh_sport; 1750 break; 1751 1752 case IPPROTO_ICMP: 1753 PULLUP_TO(hlen, ulp, struct icmphdr); 1754 //args->f_id.flags = ICMP(ulp)->icmp_type; 1755 break; 1756 1757 default: 1758 break; 1759 } 1760 } else { 1761 if (offset == 1 && proto == IPPROTO_TCP) { 1762 /* RFC 3128 */ 1763 goto pullup_failed; 1764 } 1765 } 1766 1767 UPDATE_POINTERS(); 1768 args->f_id.addr_type = 4; 1769 args->f_id.src_ip = ntohl(src_ip.s_addr); 1770 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1771 } else { 1772 proto = 0; 1773 dst_ip.s_addr = src_ip.s_addr = 0; 1774 1775 args->f_id.addr_type = 1; /* XXX */ 1776 } 1777 #undef PULLUP_TO 1778 pktlen = iplen < pktlen ? iplen: pktlen; 1779 1780 /* Properly initialize the rest of f_id */ 1781 args->f_id.proto = proto; 1782 args->f_id.src_port = src_port = ntohs(src_port); 1783 args->f_id.dst_port = dst_port = ntohs(dst_port); 1784 1785 IPFW_PF_RLOCK(chain); 1786 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ 1787 IPFW_PF_RUNLOCK(chain); 1788 return (IP_FW_PASS); /* accept */ 1789 } 1790 if (args->flags & IPFW_ARGS_REF) { 1791 /* 1792 * Packet has already been tagged as a result of a previous 1793 * match on rule args->rule aka args->rule_id (PIPE, QUEUE, 1794 * REASS, NETGRAPH, DIVERT/TEE...) 1795 * Validate the slot and continue from the next one 1796 * if still present, otherwise do a lookup. 1797 */ 1798 f_pos = (args->rule.chain_id == chain->id) ? 1799 args->rule.slot : 1800 ipfw_find_rule(chain, args->rule.rulenum, 1801 args->rule.rule_id); 1802 } else { 1803 f_pos = 0; 1804 } 1805 1806 if (args->flags & IPFW_ARGS_IN) { 1807 iif = args->ifp; 1808 oif = NULL; 1809 } else { 1810 MPASS(args->flags & IPFW_ARGS_OUT); 1811 iif = mem ? NULL : m_rcvif(m); 1812 oif = args->ifp; 1813 } 1814 1815 /* 1816 * Now scan the rules, and parse microinstructions for each rule. 1817 * We have two nested loops and an inner switch. Sometimes we 1818 * need to break out of one or both loops, or re-enter one of 1819 * the loops with updated variables. Loop variables are: 1820 * 1821 * f_pos (outer loop) points to the current rule. 1822 * On output it points to the matching rule. 1823 * done (outer loop) is used as a flag to break the loop. 1824 * l (inner loop) residual length of current rule. 1825 * cmd points to the current microinstruction. 1826 * 1827 * We break the inner loop by setting l=0 and possibly 1828 * cmdlen=0 if we don't want to advance cmd. 1829 * We break the outer loop by setting done=1 1830 * We can restart the inner loop by setting l>0 and f_pos, f, cmd 1831 * as needed. 1832 */ 1833 for (; f_pos < chain->n_rules; f_pos++) { 1834 ipfw_insn *cmd; 1835 uint32_t tablearg = 0; 1836 int l, cmdlen, skip_or; /* skip rest of OR block */ 1837 struct ip_fw *f; 1838 1839 f = chain->map[f_pos]; 1840 if (V_set_disable & (1 << f->set) ) 1841 continue; 1842 1843 skip_or = 0; 1844 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 1845 l -= cmdlen, cmd += cmdlen) { 1846 int match; 1847 1848 /* 1849 * check_body is a jump target used when we find a 1850 * CHECK_STATE, and need to jump to the body of 1851 * the target rule. 1852 */ 1853 1854 /* check_body: */ 1855 cmdlen = F_LEN(cmd); 1856 /* 1857 * An OR block (insn_1 || .. || insn_n) has the 1858 * F_OR bit set in all but the last instruction. 1859 * The first match will set "skip_or", and cause 1860 * the following instructions to be skipped until 1861 * past the one with the F_OR bit clear. 1862 */ 1863 if (skip_or) { /* skip this instruction */ 1864 if ((cmd->len & F_OR) == 0) 1865 skip_or = 0; /* next one is good */ 1866 continue; 1867 } 1868 match = 0; /* set to 1 if we succeed */ 1869 1870 switch (cmd->opcode) { 1871 /* 1872 * The first set of opcodes compares the packet's 1873 * fields with some pattern, setting 'match' if a 1874 * match is found. At the end of the loop there is 1875 * logic to deal with F_NOT and F_OR flags associated 1876 * with the opcode. 1877 */ 1878 case O_NOP: 1879 match = 1; 1880 break; 1881 1882 case O_FORWARD_MAC: 1883 printf("ipfw: opcode %d unimplemented\n", 1884 cmd->opcode); 1885 break; 1886 1887 case O_GID: 1888 case O_UID: 1889 case O_JAIL: 1890 /* 1891 * We only check offset == 0 && proto != 0, 1892 * as this ensures that we have a 1893 * packet with the ports info. 1894 */ 1895 if (offset != 0) 1896 break; 1897 if (proto == IPPROTO_TCP || 1898 proto == IPPROTO_UDP || 1899 proto == IPPROTO_UDPLITE) 1900 match = check_uidgid( 1901 (ipfw_insn_u32 *)cmd, 1902 args, &ucred_lookup, 1903 #ifdef __FreeBSD__ 1904 &ucred_cache); 1905 #else 1906 (void *)&ucred_cache); 1907 #endif 1908 break; 1909 1910 case O_RECV: 1911 match = iface_match(iif, (ipfw_insn_if *)cmd, 1912 chain, &tablearg); 1913 break; 1914 1915 case O_XMIT: 1916 match = iface_match(oif, (ipfw_insn_if *)cmd, 1917 chain, &tablearg); 1918 break; 1919 1920 case O_VIA: 1921 match = iface_match(args->ifp, 1922 (ipfw_insn_if *)cmd, chain, &tablearg); 1923 break; 1924 1925 case O_MACADDR2: 1926 if (args->flags & IPFW_ARGS_ETHER) { 1927 u_int32_t *want = (u_int32_t *) 1928 ((ipfw_insn_mac *)cmd)->addr; 1929 u_int32_t *mask = (u_int32_t *) 1930 ((ipfw_insn_mac *)cmd)->mask; 1931 u_int32_t *hdr = (u_int32_t *)eh; 1932 1933 match = 1934 ( want[0] == (hdr[0] & mask[0]) && 1935 want[1] == (hdr[1] & mask[1]) && 1936 want[2] == (hdr[2] & mask[2]) ); 1937 } 1938 break; 1939 1940 case O_MAC_TYPE: 1941 if (args->flags & IPFW_ARGS_ETHER) { 1942 u_int16_t *p = 1943 ((ipfw_insn_u16 *)cmd)->ports; 1944 int i; 1945 1946 for (i = cmdlen - 1; !match && i>0; 1947 i--, p += 2) 1948 match = 1949 (ntohs(eh->ether_type) >= 1950 p[0] && 1951 ntohs(eh->ether_type) <= 1952 p[1]); 1953 } 1954 break; 1955 1956 case O_FRAG: 1957 if (is_ipv4) { 1958 /* 1959 * Since flags_match() works with 1960 * uint8_t we pack ip_off into 8 bits. 1961 * For this match offset is a boolean. 1962 */ 1963 match = flags_match(cmd, 1964 ((ntohs(ip->ip_off) & ~IP_OFFMASK) 1965 >> 8) | (offset != 0)); 1966 } else { 1967 /* 1968 * Compatiblity: historically bare 1969 * "frag" would match IPv6 fragments. 1970 */ 1971 match = (cmd->arg1 == 0x1 && 1972 (offset != 0)); 1973 } 1974 break; 1975 1976 case O_IN: /* "out" is "not in" */ 1977 match = (oif == NULL); 1978 break; 1979 1980 case O_LAYER2: 1981 match = (args->flags & IPFW_ARGS_ETHER); 1982 break; 1983 1984 case O_DIVERTED: 1985 if ((args->flags & IPFW_ARGS_REF) == 0) 1986 break; 1987 /* 1988 * For diverted packets, args->rule.info 1989 * contains the divert port (in host format) 1990 * reason and direction. 1991 */ 1992 match = ((args->rule.info & IPFW_IS_MASK) == 1993 IPFW_IS_DIVERT) && ( 1994 ((args->rule.info & IPFW_INFO_IN) ? 1995 1: 2) & cmd->arg1); 1996 break; 1997 1998 case O_PROTO: 1999 /* 2000 * We do not allow an arg of 0 so the 2001 * check of "proto" only suffices. 2002 */ 2003 match = (proto == cmd->arg1); 2004 break; 2005 2006 case O_IP_SRC: 2007 match = is_ipv4 && 2008 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2009 src_ip.s_addr); 2010 break; 2011 2012 case O_IP_DST_LOOKUP: 2013 { 2014 void *pkey; 2015 uint32_t vidx, key; 2016 uint16_t keylen; 2017 2018 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { 2019 /* Determine lookup key type */ 2020 vidx = ((ipfw_insn_u32 *)cmd)->d[1]; 2021 if (vidx != 4 /* uid */ && 2022 vidx != 5 /* jail */ && 2023 is_ipv6 == 0 && is_ipv4 == 0) 2024 break; 2025 /* Determine key length */ 2026 if (vidx == 0 /* dst-ip */ || 2027 vidx == 1 /* src-ip */) 2028 keylen = is_ipv6 ? 2029 sizeof(struct in6_addr): 2030 sizeof(in_addr_t); 2031 else { 2032 keylen = sizeof(key); 2033 pkey = &key; 2034 } 2035 if (vidx == 0 /* dst-ip */) 2036 pkey = is_ipv4 ? (void *)&dst_ip: 2037 (void *)&args->f_id.dst_ip6; 2038 else if (vidx == 1 /* src-ip */) 2039 pkey = is_ipv4 ? (void *)&src_ip: 2040 (void *)&args->f_id.src_ip6; 2041 else if (vidx == 6 /* dscp */) { 2042 if (is_ipv4) 2043 key = ip->ip_tos >> 2; 2044 else { 2045 key = args->f_id.flow_id6; 2046 key = (key & 0x0f) << 2 | 2047 (key & 0xf000) >> 14; 2048 } 2049 key &= 0x3f; 2050 } else if (vidx == 2 /* dst-port */ || 2051 vidx == 3 /* src-port */) { 2052 /* Skip fragments */ 2053 if (offset != 0) 2054 break; 2055 /* Skip proto without ports */ 2056 if (proto != IPPROTO_TCP && 2057 proto != IPPROTO_UDP && 2058 proto != IPPROTO_UDPLITE && 2059 proto != IPPROTO_SCTP) 2060 break; 2061 if (vidx == 2 /* dst-port */) 2062 key = dst_port; 2063 else 2064 key = src_port; 2065 } 2066 #ifndef USERSPACE 2067 else if (vidx == 4 /* uid */ || 2068 vidx == 5 /* jail */) { 2069 check_uidgid( 2070 (ipfw_insn_u32 *)cmd, 2071 args, &ucred_lookup, 2072 #ifdef __FreeBSD__ 2073 &ucred_cache); 2074 if (vidx == 4 /* uid */) 2075 key = ucred_cache->cr_uid; 2076 else if (vidx == 5 /* jail */) 2077 key = ucred_cache->cr_prison->pr_id; 2078 #else /* !__FreeBSD__ */ 2079 (void *)&ucred_cache); 2080 if (vidx == 4 /* uid */) 2081 key = ucred_cache.uid; 2082 else if (vidx == 5 /* jail */) 2083 key = ucred_cache.xid; 2084 #endif /* !__FreeBSD__ */ 2085 } 2086 #endif /* !USERSPACE */ 2087 else 2088 break; 2089 match = ipfw_lookup_table(chain, 2090 cmd->arg1, keylen, pkey, &vidx); 2091 if (!match) 2092 break; 2093 tablearg = vidx; 2094 break; 2095 } 2096 /* cmdlen =< F_INSN_SIZE(ipfw_insn_u32) */ 2097 /* FALLTHROUGH */ 2098 } 2099 case O_IP_SRC_LOOKUP: 2100 { 2101 void *pkey; 2102 uint32_t vidx; 2103 uint16_t keylen; 2104 2105 if (is_ipv4) { 2106 keylen = sizeof(in_addr_t); 2107 if (cmd->opcode == O_IP_DST_LOOKUP) 2108 pkey = &dst_ip; 2109 else 2110 pkey = &src_ip; 2111 } else if (is_ipv6) { 2112 keylen = sizeof(struct in6_addr); 2113 if (cmd->opcode == O_IP_DST_LOOKUP) 2114 pkey = &args->f_id.dst_ip6; 2115 else 2116 pkey = &args->f_id.src_ip6; 2117 } else 2118 break; 2119 match = ipfw_lookup_table(chain, cmd->arg1, 2120 keylen, pkey, &vidx); 2121 if (!match) 2122 break; 2123 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) { 2124 match = ((ipfw_insn_u32 *)cmd)->d[0] == 2125 TARG_VAL(chain, vidx, tag); 2126 if (!match) 2127 break; 2128 } 2129 tablearg = vidx; 2130 break; 2131 } 2132 2133 case O_IP_FLOW_LOOKUP: 2134 { 2135 uint32_t v = 0; 2136 match = ipfw_lookup_table(chain, 2137 cmd->arg1, 0, &args->f_id, &v); 2138 if (!match) 2139 break; 2140 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 2141 match = ((ipfw_insn_u32 *)cmd)->d[0] == 2142 TARG_VAL(chain, v, tag); 2143 if (match) 2144 tablearg = v; 2145 } 2146 break; 2147 case O_IP_SRC_MASK: 2148 case O_IP_DST_MASK: 2149 if (is_ipv4) { 2150 uint32_t a = 2151 (cmd->opcode == O_IP_DST_MASK) ? 2152 dst_ip.s_addr : src_ip.s_addr; 2153 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 2154 int i = cmdlen-1; 2155 2156 for (; !match && i>0; i-= 2, p+= 2) 2157 match = (p[0] == (a & p[1])); 2158 } 2159 break; 2160 2161 case O_IP_SRC_ME: 2162 if (is_ipv4) { 2163 match = in_localip(src_ip); 2164 break; 2165 } 2166 #ifdef INET6 2167 /* FALLTHROUGH */ 2168 case O_IP6_SRC_ME: 2169 match = is_ipv6 && 2170 ipfw_localip6(&args->f_id.src_ip6); 2171 #endif 2172 break; 2173 2174 case O_IP_DST_SET: 2175 case O_IP_SRC_SET: 2176 if (is_ipv4) { 2177 u_int32_t *d = (u_int32_t *)(cmd+1); 2178 u_int32_t addr = 2179 cmd->opcode == O_IP_DST_SET ? 2180 args->f_id.dst_ip : 2181 args->f_id.src_ip; 2182 2183 if (addr < d[0]) 2184 break; 2185 addr -= d[0]; /* subtract base */ 2186 match = (addr < cmd->arg1) && 2187 ( d[ 1 + (addr>>5)] & 2188 (1<<(addr & 0x1f)) ); 2189 } 2190 break; 2191 2192 case O_IP_DST: 2193 match = is_ipv4 && 2194 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2195 dst_ip.s_addr); 2196 break; 2197 2198 case O_IP_DST_ME: 2199 if (is_ipv4) { 2200 match = in_localip(dst_ip); 2201 break; 2202 } 2203 #ifdef INET6 2204 /* FALLTHROUGH */ 2205 case O_IP6_DST_ME: 2206 match = is_ipv6 && 2207 ipfw_localip6(&args->f_id.dst_ip6); 2208 #endif 2209 break; 2210 2211 case O_IP_SRCPORT: 2212 case O_IP_DSTPORT: 2213 /* 2214 * offset == 0 && proto != 0 is enough 2215 * to guarantee that we have a 2216 * packet with port info. 2217 */ 2218 if ((proto == IPPROTO_UDP || 2219 proto == IPPROTO_UDPLITE || 2220 proto == IPPROTO_TCP || 2221 proto == IPPROTO_SCTP) && offset == 0) { 2222 u_int16_t x = 2223 (cmd->opcode == O_IP_SRCPORT) ? 2224 src_port : dst_port ; 2225 u_int16_t *p = 2226 ((ipfw_insn_u16 *)cmd)->ports; 2227 int i; 2228 2229 for (i = cmdlen - 1; !match && i>0; 2230 i--, p += 2) 2231 match = (x>=p[0] && x<=p[1]); 2232 } 2233 break; 2234 2235 case O_ICMPTYPE: 2236 match = (offset == 0 && proto==IPPROTO_ICMP && 2237 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 2238 break; 2239 2240 #ifdef INET6 2241 case O_ICMP6TYPE: 2242 match = is_ipv6 && offset == 0 && 2243 proto==IPPROTO_ICMPV6 && 2244 icmp6type_match( 2245 ICMP6(ulp)->icmp6_type, 2246 (ipfw_insn_u32 *)cmd); 2247 break; 2248 #endif /* INET6 */ 2249 2250 case O_IPOPT: 2251 match = (is_ipv4 && 2252 ipopts_match(ip, cmd) ); 2253 break; 2254 2255 case O_IPVER: 2256 match = ((is_ipv4 || is_ipv6) && 2257 cmd->arg1 == ip->ip_v); 2258 break; 2259 2260 case O_IPID: 2261 case O_IPTTL: 2262 if (!is_ipv4) 2263 break; 2264 case O_IPLEN: 2265 { /* only for IP packets */ 2266 uint16_t x; 2267 uint16_t *p; 2268 int i; 2269 2270 if (cmd->opcode == O_IPLEN) 2271 x = iplen; 2272 else if (cmd->opcode == O_IPTTL) 2273 x = ip->ip_ttl; 2274 else /* must be IPID */ 2275 x = ntohs(ip->ip_id); 2276 if (cmdlen == 1) { 2277 match = (cmd->arg1 == x); 2278 break; 2279 } 2280 /* otherwise we have ranges */ 2281 p = ((ipfw_insn_u16 *)cmd)->ports; 2282 i = cmdlen - 1; 2283 for (; !match && i>0; i--, p += 2) 2284 match = (x >= p[0] && x <= p[1]); 2285 } 2286 break; 2287 2288 case O_IPPRECEDENCE: 2289 match = (is_ipv4 && 2290 (cmd->arg1 == (ip->ip_tos & 0xe0)) ); 2291 break; 2292 2293 case O_IPTOS: 2294 match = (is_ipv4 && 2295 flags_match(cmd, ip->ip_tos)); 2296 break; 2297 2298 case O_DSCP: 2299 { 2300 uint32_t *p; 2301 uint16_t x; 2302 2303 p = ((ipfw_insn_u32 *)cmd)->d; 2304 2305 if (is_ipv4) 2306 x = ip->ip_tos >> 2; 2307 else if (is_ipv6) { 2308 uint8_t *v; 2309 v = &((struct ip6_hdr *)ip)->ip6_vfc; 2310 x = (*v & 0x0F) << 2; 2311 v++; 2312 x |= *v >> 6; 2313 } else 2314 break; 2315 2316 /* DSCP bitmask is stored as low_u32 high_u32 */ 2317 if (x >= 32) 2318 match = *(p + 1) & (1 << (x - 32)); 2319 else 2320 match = *p & (1 << x); 2321 } 2322 break; 2323 2324 case O_TCPDATALEN: 2325 if (proto == IPPROTO_TCP && offset == 0) { 2326 struct tcphdr *tcp; 2327 uint16_t x; 2328 uint16_t *p; 2329 int i; 2330 #ifdef INET6 2331 if (is_ipv6) { 2332 struct ip6_hdr *ip6; 2333 2334 ip6 = (struct ip6_hdr *)ip; 2335 if (ip6->ip6_plen == 0) { 2336 /* 2337 * Jumbo payload is not 2338 * supported by this 2339 * opcode. 2340 */ 2341 break; 2342 } 2343 x = iplen - hlen; 2344 } else 2345 #endif /* INET6 */ 2346 x = iplen - (ip->ip_hl << 2); 2347 tcp = TCP(ulp); 2348 x -= tcp->th_off << 2; 2349 if (cmdlen == 1) { 2350 match = (cmd->arg1 == x); 2351 break; 2352 } 2353 /* otherwise we have ranges */ 2354 p = ((ipfw_insn_u16 *)cmd)->ports; 2355 i = cmdlen - 1; 2356 for (; !match && i>0; i--, p += 2) 2357 match = (x >= p[0] && x <= p[1]); 2358 } 2359 break; 2360 2361 case O_TCPFLAGS: 2362 match = (proto == IPPROTO_TCP && offset == 0 && 2363 flags_match(cmd, TCP(ulp)->th_flags)); 2364 break; 2365 2366 case O_TCPOPTS: 2367 if (proto == IPPROTO_TCP && offset == 0 && ulp){ 2368 PULLUP_LEN_LOCKED(hlen, ulp, 2369 (TCP(ulp)->th_off << 2)); 2370 match = tcpopts_match(TCP(ulp), cmd); 2371 } 2372 break; 2373 2374 case O_TCPSEQ: 2375 match = (proto == IPPROTO_TCP && offset == 0 && 2376 ((ipfw_insn_u32 *)cmd)->d[0] == 2377 TCP(ulp)->th_seq); 2378 break; 2379 2380 case O_TCPACK: 2381 match = (proto == IPPROTO_TCP && offset == 0 && 2382 ((ipfw_insn_u32 *)cmd)->d[0] == 2383 TCP(ulp)->th_ack); 2384 break; 2385 2386 case O_TCPMSS: 2387 if (proto == IPPROTO_TCP && 2388 (args->f_id._flags & TH_SYN) != 0 && 2389 ulp != NULL) { 2390 uint16_t mss, *p; 2391 int i; 2392 2393 PULLUP_LEN_LOCKED(hlen, ulp, 2394 (TCP(ulp)->th_off << 2)); 2395 if ((tcpopts_parse(TCP(ulp), &mss) & 2396 IP_FW_TCPOPT_MSS) == 0) 2397 break; 2398 if (cmdlen == 1) { 2399 match = (cmd->arg1 == mss); 2400 break; 2401 } 2402 /* Otherwise we have ranges. */ 2403 p = ((ipfw_insn_u16 *)cmd)->ports; 2404 i = cmdlen - 1; 2405 for (; !match && i > 0; i--, p += 2) 2406 match = (mss >= p[0] && 2407 mss <= p[1]); 2408 } 2409 break; 2410 2411 case O_TCPWIN: 2412 if (proto == IPPROTO_TCP && offset == 0) { 2413 uint16_t x; 2414 uint16_t *p; 2415 int i; 2416 2417 x = ntohs(TCP(ulp)->th_win); 2418 if (cmdlen == 1) { 2419 match = (cmd->arg1 == x); 2420 break; 2421 } 2422 /* Otherwise we have ranges. */ 2423 p = ((ipfw_insn_u16 *)cmd)->ports; 2424 i = cmdlen - 1; 2425 for (; !match && i > 0; i--, p += 2) 2426 match = (x >= p[0] && x <= p[1]); 2427 } 2428 break; 2429 2430 case O_ESTAB: 2431 /* reject packets which have SYN only */ 2432 /* XXX should i also check for TH_ACK ? */ 2433 match = (proto == IPPROTO_TCP && offset == 0 && 2434 (TCP(ulp)->th_flags & 2435 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 2436 break; 2437 2438 case O_ALTQ: { 2439 struct pf_mtag *at; 2440 struct m_tag *mtag; 2441 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 2442 2443 /* 2444 * ALTQ uses mbuf tags from another 2445 * packet filtering system - pf(4). 2446 * We allocate a tag in its format 2447 * and fill it in, pretending to be pf(4). 2448 */ 2449 match = 1; 2450 at = pf_find_mtag(m); 2451 if (at != NULL && at->qid != 0) 2452 break; 2453 mtag = m_tag_get(PACKET_TAG_PF, 2454 sizeof(struct pf_mtag), M_NOWAIT | M_ZERO); 2455 if (mtag == NULL) { 2456 /* 2457 * Let the packet fall back to the 2458 * default ALTQ. 2459 */ 2460 break; 2461 } 2462 m_tag_prepend(m, mtag); 2463 at = (struct pf_mtag *)(mtag + 1); 2464 at->qid = altq->qid; 2465 at->hdr = ip; 2466 break; 2467 } 2468 2469 case O_LOG: 2470 ipfw_log(chain, f, hlen, args, 2471 offset | ip6f_mf, tablearg, ip); 2472 match = 1; 2473 break; 2474 2475 case O_PROB: 2476 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 2477 break; 2478 2479 case O_VERREVPATH: 2480 /* Outgoing packets automatically pass/match */ 2481 match = (args->flags & IPFW_ARGS_OUT || 2482 ( 2483 #ifdef INET6 2484 is_ipv6 ? 2485 verify_path6(&(args->f_id.src_ip6), 2486 iif, args->f_id.fib) : 2487 #endif 2488 verify_path(src_ip, iif, args->f_id.fib))); 2489 break; 2490 2491 case O_VERSRCREACH: 2492 /* Outgoing packets automatically pass/match */ 2493 match = (hlen > 0 && ((oif != NULL) || ( 2494 #ifdef INET6 2495 is_ipv6 ? 2496 verify_path6(&(args->f_id.src_ip6), 2497 NULL, args->f_id.fib) : 2498 #endif 2499 verify_path(src_ip, NULL, args->f_id.fib)))); 2500 break; 2501 2502 case O_ANTISPOOF: 2503 /* Outgoing packets automatically pass/match */ 2504 if (oif == NULL && hlen > 0 && 2505 ( (is_ipv4 && in_localaddr(src_ip)) 2506 #ifdef INET6 2507 || (is_ipv6 && 2508 in6_localaddr(&(args->f_id.src_ip6))) 2509 #endif 2510 )) 2511 match = 2512 #ifdef INET6 2513 is_ipv6 ? verify_path6( 2514 &(args->f_id.src_ip6), iif, 2515 args->f_id.fib) : 2516 #endif 2517 verify_path(src_ip, iif, 2518 args->f_id.fib); 2519 else 2520 match = 1; 2521 break; 2522 2523 case O_IPSEC: 2524 match = (m_tag_find(m, 2525 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 2526 /* otherwise no match */ 2527 break; 2528 2529 #ifdef INET6 2530 case O_IP6_SRC: 2531 match = is_ipv6 && 2532 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 2533 &((ipfw_insn_ip6 *)cmd)->addr6); 2534 break; 2535 2536 case O_IP6_DST: 2537 match = is_ipv6 && 2538 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 2539 &((ipfw_insn_ip6 *)cmd)->addr6); 2540 break; 2541 case O_IP6_SRC_MASK: 2542 case O_IP6_DST_MASK: 2543 if (is_ipv6) { 2544 int i = cmdlen - 1; 2545 struct in6_addr p; 2546 struct in6_addr *d = 2547 &((ipfw_insn_ip6 *)cmd)->addr6; 2548 2549 for (; !match && i > 0; d += 2, 2550 i -= F_INSN_SIZE(struct in6_addr) 2551 * 2) { 2552 p = (cmd->opcode == 2553 O_IP6_SRC_MASK) ? 2554 args->f_id.src_ip6: 2555 args->f_id.dst_ip6; 2556 APPLY_MASK(&p, &d[1]); 2557 match = 2558 IN6_ARE_ADDR_EQUAL(&d[0], 2559 &p); 2560 } 2561 } 2562 break; 2563 2564 case O_FLOW6ID: 2565 match = is_ipv6 && 2566 flow6id_match(args->f_id.flow_id6, 2567 (ipfw_insn_u32 *) cmd); 2568 break; 2569 2570 case O_EXT_HDR: 2571 match = is_ipv6 && 2572 (ext_hd & ((ipfw_insn *) cmd)->arg1); 2573 break; 2574 2575 case O_IP6: 2576 match = is_ipv6; 2577 break; 2578 #endif 2579 2580 case O_IP4: 2581 match = is_ipv4; 2582 break; 2583 2584 case O_TAG: { 2585 struct m_tag *mtag; 2586 uint32_t tag = TARG(cmd->arg1, tag); 2587 2588 /* Packet is already tagged with this tag? */ 2589 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 2590 2591 /* We have `untag' action when F_NOT flag is 2592 * present. And we must remove this mtag from 2593 * mbuf and reset `match' to zero (`match' will 2594 * be inversed later). 2595 * Otherwise we should allocate new mtag and 2596 * push it into mbuf. 2597 */ 2598 if (cmd->len & F_NOT) { /* `untag' action */ 2599 if (mtag != NULL) 2600 m_tag_delete(m, mtag); 2601 match = 0; 2602 } else { 2603 if (mtag == NULL) { 2604 mtag = m_tag_alloc( MTAG_IPFW, 2605 tag, 0, M_NOWAIT); 2606 if (mtag != NULL) 2607 m_tag_prepend(m, mtag); 2608 } 2609 match = 1; 2610 } 2611 break; 2612 } 2613 2614 case O_FIB: /* try match the specified fib */ 2615 if (args->f_id.fib == cmd->arg1) 2616 match = 1; 2617 break; 2618 2619 case O_SOCKARG: { 2620 #ifndef USERSPACE /* not supported in userspace */ 2621 struct inpcb *inp = args->inp; 2622 struct inpcbinfo *pi; 2623 bool inp_locked = false; 2624 2625 if (proto == IPPROTO_TCP) 2626 pi = &V_tcbinfo; 2627 else if (proto == IPPROTO_UDP) 2628 pi = &V_udbinfo; 2629 else if (proto == IPPROTO_UDPLITE) 2630 pi = &V_ulitecbinfo; 2631 else 2632 break; 2633 2634 /* 2635 * XXXRW: so_user_cookie should almost 2636 * certainly be inp_user_cookie? 2637 */ 2638 2639 /* 2640 * For incoming packet lookup the inpcb 2641 * using the src/dest ip/port tuple. 2642 */ 2643 if (is_ipv4 && inp == NULL) { 2644 inp = in_pcblookup(pi, 2645 src_ip, htons(src_port), 2646 dst_ip, htons(dst_port), 2647 INPLOOKUP_RLOCKPCB, NULL); 2648 inp_locked = true; 2649 } 2650 #ifdef INET6 2651 if (is_ipv6 && inp == NULL) { 2652 inp = in6_pcblookup(pi, 2653 &args->f_id.src_ip6, 2654 htons(src_port), 2655 &args->f_id.dst_ip6, 2656 htons(dst_port), 2657 INPLOOKUP_RLOCKPCB, NULL); 2658 inp_locked = true; 2659 } 2660 #endif /* INET6 */ 2661 if (inp != NULL) { 2662 if (inp->inp_socket) { 2663 tablearg = 2664 inp->inp_socket->so_user_cookie; 2665 if (tablearg) 2666 match = 1; 2667 } 2668 if (inp_locked) 2669 INP_RUNLOCK(inp); 2670 } 2671 #endif /* !USERSPACE */ 2672 break; 2673 } 2674 2675 case O_TAGGED: { 2676 struct m_tag *mtag; 2677 uint32_t tag = TARG(cmd->arg1, tag); 2678 2679 if (cmdlen == 1) { 2680 match = m_tag_locate(m, MTAG_IPFW, 2681 tag, NULL) != NULL; 2682 break; 2683 } 2684 2685 /* we have ranges */ 2686 for (mtag = m_tag_first(m); 2687 mtag != NULL && !match; 2688 mtag = m_tag_next(m, mtag)) { 2689 uint16_t *p; 2690 int i; 2691 2692 if (mtag->m_tag_cookie != MTAG_IPFW) 2693 continue; 2694 2695 p = ((ipfw_insn_u16 *)cmd)->ports; 2696 i = cmdlen - 1; 2697 for(; !match && i > 0; i--, p += 2) 2698 match = 2699 mtag->m_tag_id >= p[0] && 2700 mtag->m_tag_id <= p[1]; 2701 } 2702 break; 2703 } 2704 2705 /* 2706 * The second set of opcodes represents 'actions', 2707 * i.e. the terminal part of a rule once the packet 2708 * matches all previous patterns. 2709 * Typically there is only one action for each rule, 2710 * and the opcode is stored at the end of the rule 2711 * (but there are exceptions -- see below). 2712 * 2713 * In general, here we set retval and terminate the 2714 * outer loop (would be a 'break 3' in some language, 2715 * but we need to set l=0, done=1) 2716 * 2717 * Exceptions: 2718 * O_COUNT and O_SKIPTO actions: 2719 * instead of terminating, we jump to the next rule 2720 * (setting l=0), or to the SKIPTO target (setting 2721 * f/f_len, cmd and l as needed), respectively. 2722 * 2723 * O_TAG, O_LOG and O_ALTQ action parameters: 2724 * perform some action and set match = 1; 2725 * 2726 * O_LIMIT and O_KEEP_STATE: these opcodes are 2727 * not real 'actions', and are stored right 2728 * before the 'action' part of the rule (one 2729 * exception is O_SKIP_ACTION which could be 2730 * between these opcodes and 'action' one). 2731 * These opcodes try to install an entry in the 2732 * state tables; if successful, we continue with 2733 * the next opcode (match=1; break;), otherwise 2734 * the packet must be dropped (set retval, 2735 * break loops with l=0, done=1) 2736 * 2737 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2738 * cause a lookup of the state table, and a jump 2739 * to the 'action' part of the parent rule 2740 * if an entry is found, or 2741 * (CHECK_STATE only) a jump to the next rule if 2742 * the entry is not found. 2743 * The result of the lookup is cached so that 2744 * further instances of these opcodes become NOPs. 2745 * The jump to the next rule is done by setting 2746 * l=0, cmdlen=0. 2747 * 2748 * O_SKIP_ACTION: this opcode is not a real 'action' 2749 * either, and is stored right before the 'action' 2750 * part of the rule, right after the O_KEEP_STATE 2751 * opcode. It causes match failure so the real 2752 * 'action' could be executed only if the rule 2753 * is checked via dynamic rule from the state 2754 * table, as in such case execution starts 2755 * from the true 'action' opcode directly. 2756 * 2757 */ 2758 case O_LIMIT: 2759 case O_KEEP_STATE: 2760 if (ipfw_dyn_install_state(chain, f, 2761 (ipfw_insn_limit *)cmd, args, ulp, 2762 pktlen, &dyn_info, tablearg)) { 2763 /* error or limit violation */ 2764 retval = IP_FW_DENY; 2765 l = 0; /* exit inner loop */ 2766 done = 1; /* exit outer loop */ 2767 } 2768 match = 1; 2769 break; 2770 2771 case O_PROBE_STATE: 2772 case O_CHECK_STATE: 2773 /* 2774 * dynamic rules are checked at the first 2775 * keep-state or check-state occurrence, 2776 * with the result being stored in dyn_info. 2777 * The compiler introduces a PROBE_STATE 2778 * instruction for us when we have a 2779 * KEEP_STATE (because PROBE_STATE needs 2780 * to be run first). 2781 */ 2782 if (DYN_LOOKUP_NEEDED(&dyn_info, cmd) && 2783 (q = ipfw_dyn_lookup_state(args, ulp, 2784 pktlen, cmd, &dyn_info)) != NULL) { 2785 /* 2786 * Found dynamic entry, jump to the 2787 * 'action' part of the parent rule 2788 * by setting f, cmd, l and clearing 2789 * cmdlen. 2790 */ 2791 f = q; 2792 f_pos = dyn_info.f_pos; 2793 cmd = ACTION_PTR(f); 2794 l = f->cmd_len - f->act_ofs; 2795 cmdlen = 0; 2796 match = 1; 2797 break; 2798 } 2799 /* 2800 * Dynamic entry not found. If CHECK_STATE, 2801 * skip to next rule, if PROBE_STATE just 2802 * ignore and continue with next opcode. 2803 */ 2804 if (cmd->opcode == O_CHECK_STATE) 2805 l = 0; /* exit inner loop */ 2806 match = 1; 2807 break; 2808 2809 case O_SKIP_ACTION: 2810 match = 0; /* skip to the next rule */ 2811 l = 0; /* exit inner loop */ 2812 break; 2813 2814 case O_ACCEPT: 2815 retval = 0; /* accept */ 2816 l = 0; /* exit inner loop */ 2817 done = 1; /* exit outer loop */ 2818 break; 2819 2820 case O_PIPE: 2821 case O_QUEUE: 2822 set_match(args, f_pos, chain); 2823 args->rule.info = TARG(cmd->arg1, pipe); 2824 if (cmd->opcode == O_PIPE) 2825 args->rule.info |= IPFW_IS_PIPE; 2826 if (V_fw_one_pass) 2827 args->rule.info |= IPFW_ONEPASS; 2828 retval = IP_FW_DUMMYNET; 2829 l = 0; /* exit inner loop */ 2830 done = 1; /* exit outer loop */ 2831 break; 2832 2833 case O_DIVERT: 2834 case O_TEE: 2835 if (args->flags & IPFW_ARGS_ETHER) 2836 break; /* not on layer 2 */ 2837 /* otherwise this is terminal */ 2838 l = 0; /* exit inner loop */ 2839 done = 1; /* exit outer loop */ 2840 retval = (cmd->opcode == O_DIVERT) ? 2841 IP_FW_DIVERT : IP_FW_TEE; 2842 set_match(args, f_pos, chain); 2843 args->rule.info = TARG(cmd->arg1, divert); 2844 break; 2845 2846 case O_COUNT: 2847 IPFW_INC_RULE_COUNTER(f, pktlen); 2848 l = 0; /* exit inner loop */ 2849 break; 2850 2851 case O_SKIPTO: 2852 IPFW_INC_RULE_COUNTER(f, pktlen); 2853 f_pos = JUMP(chain, f, cmd->arg1, tablearg, 0); 2854 /* 2855 * Skip disabled rules, and re-enter 2856 * the inner loop with the correct 2857 * f_pos, f, l and cmd. 2858 * Also clear cmdlen and skip_or 2859 */ 2860 for (; f_pos < chain->n_rules - 1 && 2861 (V_set_disable & 2862 (1 << chain->map[f_pos]->set)); 2863 f_pos++) 2864 ; 2865 /* Re-enter the inner loop at the skipto rule. */ 2866 f = chain->map[f_pos]; 2867 l = f->cmd_len; 2868 cmd = f->cmd; 2869 match = 1; 2870 cmdlen = 0; 2871 skip_or = 0; 2872 continue; 2873 break; /* not reached */ 2874 2875 case O_CALLRETURN: { 2876 /* 2877 * Implementation of `subroutine' call/return, 2878 * in the stack carried in an mbuf tag. This 2879 * is different from `skipto' in that any call 2880 * address is possible (`skipto' must prevent 2881 * backward jumps to avoid endless loops). 2882 * We have `return' action when F_NOT flag is 2883 * present. The `m_tag_id' field is used as 2884 * stack pointer. 2885 */ 2886 struct m_tag *mtag; 2887 uint16_t jmpto, *stack; 2888 2889 #define IS_CALL ((cmd->len & F_NOT) == 0) 2890 #define IS_RETURN ((cmd->len & F_NOT) != 0) 2891 /* 2892 * Hand-rolled version of m_tag_locate() with 2893 * wildcard `type'. 2894 * If not already tagged, allocate new tag. 2895 */ 2896 mtag = m_tag_first(m); 2897 while (mtag != NULL) { 2898 if (mtag->m_tag_cookie == 2899 MTAG_IPFW_CALL) 2900 break; 2901 mtag = m_tag_next(m, mtag); 2902 } 2903 if (mtag == NULL && IS_CALL) { 2904 mtag = m_tag_alloc(MTAG_IPFW_CALL, 0, 2905 IPFW_CALLSTACK_SIZE * 2906 sizeof(uint16_t), M_NOWAIT); 2907 if (mtag != NULL) 2908 m_tag_prepend(m, mtag); 2909 } 2910 2911 /* 2912 * On error both `call' and `return' just 2913 * continue with next rule. 2914 */ 2915 if (IS_RETURN && (mtag == NULL || 2916 mtag->m_tag_id == 0)) { 2917 l = 0; /* exit inner loop */ 2918 break; 2919 } 2920 if (IS_CALL && (mtag == NULL || 2921 mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) { 2922 printf("ipfw: call stack error, " 2923 "go to next rule\n"); 2924 l = 0; /* exit inner loop */ 2925 break; 2926 } 2927 2928 IPFW_INC_RULE_COUNTER(f, pktlen); 2929 stack = (uint16_t *)(mtag + 1); 2930 2931 /* 2932 * The `call' action may use cached f_pos 2933 * (in f->next_rule), whose version is written 2934 * in f->next_rule. 2935 * The `return' action, however, doesn't have 2936 * fixed jump address in cmd->arg1 and can't use 2937 * cache. 2938 */ 2939 if (IS_CALL) { 2940 stack[mtag->m_tag_id] = f->rulenum; 2941 mtag->m_tag_id++; 2942 f_pos = JUMP(chain, f, cmd->arg1, 2943 tablearg, 1); 2944 } else { /* `return' action */ 2945 mtag->m_tag_id--; 2946 jmpto = stack[mtag->m_tag_id] + 1; 2947 f_pos = ipfw_find_rule(chain, jmpto, 0); 2948 } 2949 2950 /* 2951 * Skip disabled rules, and re-enter 2952 * the inner loop with the correct 2953 * f_pos, f, l and cmd. 2954 * Also clear cmdlen and skip_or 2955 */ 2956 for (; f_pos < chain->n_rules - 1 && 2957 (V_set_disable & 2958 (1 << chain->map[f_pos]->set)); f_pos++) 2959 ; 2960 /* Re-enter the inner loop at the dest rule. */ 2961 f = chain->map[f_pos]; 2962 l = f->cmd_len; 2963 cmd = f->cmd; 2964 cmdlen = 0; 2965 skip_or = 0; 2966 continue; 2967 break; /* NOTREACHED */ 2968 } 2969 #undef IS_CALL 2970 #undef IS_RETURN 2971 2972 case O_REJECT: 2973 /* 2974 * Drop the packet and send a reject notice 2975 * if the packet is not ICMP (or is an ICMP 2976 * query), and it is not multicast/broadcast. 2977 */ 2978 if (hlen > 0 && is_ipv4 && offset == 0 && 2979 (proto != IPPROTO_ICMP || 2980 is_icmp_query(ICMP(ulp))) && 2981 !(m->m_flags & (M_BCAST|M_MCAST)) && 2982 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 2983 send_reject(args, cmd->arg1, iplen, ip); 2984 m = args->m; 2985 } 2986 /* FALLTHROUGH */ 2987 #ifdef INET6 2988 case O_UNREACH6: 2989 if (hlen > 0 && is_ipv6 && 2990 ((offset & IP6F_OFF_MASK) == 0) && 2991 (proto != IPPROTO_ICMPV6 || 2992 (is_icmp6_query(icmp6_type) == 1)) && 2993 !(m->m_flags & (M_BCAST|M_MCAST)) && 2994 !IN6_IS_ADDR_MULTICAST( 2995 &args->f_id.dst_ip6)) { 2996 send_reject6(args, 2997 cmd->opcode == O_REJECT ? 2998 map_icmp_unreach(cmd->arg1): 2999 cmd->arg1, hlen, 3000 (struct ip6_hdr *)ip); 3001 m = args->m; 3002 } 3003 /* FALLTHROUGH */ 3004 #endif 3005 case O_DENY: 3006 retval = IP_FW_DENY; 3007 l = 0; /* exit inner loop */ 3008 done = 1; /* exit outer loop */ 3009 break; 3010 3011 case O_FORWARD_IP: 3012 if (args->flags & IPFW_ARGS_ETHER) 3013 break; /* not valid on layer2 pkts */ 3014 if (q != f || 3015 dyn_info.direction == MATCH_FORWARD) { 3016 struct sockaddr_in *sa; 3017 3018 sa = &(((ipfw_insn_sa *)cmd)->sa); 3019 if (sa->sin_addr.s_addr == INADDR_ANY) { 3020 #ifdef INET6 3021 /* 3022 * We use O_FORWARD_IP opcode for 3023 * fwd rule with tablearg, but tables 3024 * now support IPv6 addresses. And 3025 * when we are inspecting IPv6 packet, 3026 * we can use nh6 field from 3027 * table_value as next_hop6 address. 3028 */ 3029 if (is_ipv6) { 3030 struct ip_fw_nh6 *nh6; 3031 3032 args->flags |= IPFW_ARGS_NH6; 3033 nh6 = &args->hopstore6; 3034 nh6->sin6_addr = TARG_VAL( 3035 chain, tablearg, nh6); 3036 nh6->sin6_port = sa->sin_port; 3037 nh6->sin6_scope_id = TARG_VAL( 3038 chain, tablearg, zoneid); 3039 } else 3040 #endif 3041 { 3042 args->flags |= IPFW_ARGS_NH4; 3043 args->hopstore.sin_port = 3044 sa->sin_port; 3045 sa = &args->hopstore; 3046 sa->sin_family = AF_INET; 3047 sa->sin_len = sizeof(*sa); 3048 sa->sin_addr.s_addr = htonl( 3049 TARG_VAL(chain, tablearg, 3050 nh4)); 3051 } 3052 } else { 3053 args->flags |= IPFW_ARGS_NH4PTR; 3054 args->next_hop = sa; 3055 } 3056 } 3057 retval = IP_FW_PASS; 3058 l = 0; /* exit inner loop */ 3059 done = 1; /* exit outer loop */ 3060 break; 3061 3062 #ifdef INET6 3063 case O_FORWARD_IP6: 3064 if (args->flags & IPFW_ARGS_ETHER) 3065 break; /* not valid on layer2 pkts */ 3066 if (q != f || 3067 dyn_info.direction == MATCH_FORWARD) { 3068 struct sockaddr_in6 *sin6; 3069 3070 sin6 = &(((ipfw_insn_sa6 *)cmd)->sa); 3071 args->flags |= IPFW_ARGS_NH6PTR; 3072 args->next_hop6 = sin6; 3073 } 3074 retval = IP_FW_PASS; 3075 l = 0; /* exit inner loop */ 3076 done = 1; /* exit outer loop */ 3077 break; 3078 #endif 3079 3080 case O_NETGRAPH: 3081 case O_NGTEE: 3082 set_match(args, f_pos, chain); 3083 args->rule.info = TARG(cmd->arg1, netgraph); 3084 if (V_fw_one_pass) 3085 args->rule.info |= IPFW_ONEPASS; 3086 retval = (cmd->opcode == O_NETGRAPH) ? 3087 IP_FW_NETGRAPH : IP_FW_NGTEE; 3088 l = 0; /* exit inner loop */ 3089 done = 1; /* exit outer loop */ 3090 break; 3091 3092 case O_SETFIB: { 3093 uint32_t fib; 3094 3095 IPFW_INC_RULE_COUNTER(f, pktlen); 3096 fib = TARG(cmd->arg1, fib) & 0x7FFF; 3097 if (fib >= rt_numfibs) 3098 fib = 0; 3099 M_SETFIB(m, fib); 3100 args->f_id.fib = fib; /* XXX */ 3101 l = 0; /* exit inner loop */ 3102 break; 3103 } 3104 3105 case O_SETDSCP: { 3106 uint16_t code; 3107 3108 code = TARG(cmd->arg1, dscp) & 0x3F; 3109 l = 0; /* exit inner loop */ 3110 if (is_ipv4) { 3111 uint16_t old; 3112 3113 old = *(uint16_t *)ip; 3114 ip->ip_tos = (code << 2) | 3115 (ip->ip_tos & 0x03); 3116 ip->ip_sum = cksum_adjust(ip->ip_sum, 3117 old, *(uint16_t *)ip); 3118 } else if (is_ipv6) { 3119 uint8_t *v; 3120 3121 v = &((struct ip6_hdr *)ip)->ip6_vfc; 3122 *v = (*v & 0xF0) | (code >> 2); 3123 v++; 3124 *v = (*v & 0x3F) | ((code & 0x03) << 6); 3125 } else 3126 break; 3127 3128 IPFW_INC_RULE_COUNTER(f, pktlen); 3129 break; 3130 } 3131 3132 case O_NAT: 3133 l = 0; /* exit inner loop */ 3134 done = 1; /* exit outer loop */ 3135 /* 3136 * Ensure that we do not invoke NAT handler for 3137 * non IPv4 packets. Libalias expects only IPv4. 3138 */ 3139 if (!is_ipv4 || !IPFW_NAT_LOADED) { 3140 retval = IP_FW_DENY; 3141 break; 3142 } 3143 3144 struct cfg_nat *t; 3145 int nat_id; 3146 3147 args->rule.info = 0; 3148 set_match(args, f_pos, chain); 3149 /* Check if this is 'global' nat rule */ 3150 if (cmd->arg1 == IP_FW_NAT44_GLOBAL) { 3151 retval = ipfw_nat_ptr(args, NULL, m); 3152 break; 3153 } 3154 t = ((ipfw_insn_nat *)cmd)->nat; 3155 if (t == NULL) { 3156 nat_id = TARG(cmd->arg1, nat); 3157 t = (*lookup_nat_ptr)(&chain->nat, nat_id); 3158 3159 if (t == NULL) { 3160 retval = IP_FW_DENY; 3161 break; 3162 } 3163 if (cmd->arg1 != IP_FW_TARG) 3164 ((ipfw_insn_nat *)cmd)->nat = t; 3165 } 3166 retval = ipfw_nat_ptr(args, t, m); 3167 break; 3168 3169 case O_REASS: { 3170 int ip_off; 3171 3172 l = 0; /* in any case exit inner loop */ 3173 if (is_ipv6) /* IPv6 is not supported yet */ 3174 break; 3175 IPFW_INC_RULE_COUNTER(f, pktlen); 3176 ip_off = ntohs(ip->ip_off); 3177 3178 /* if not fragmented, go to next rule */ 3179 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0) 3180 break; 3181 3182 args->m = m = ip_reass(m); 3183 3184 /* 3185 * do IP header checksum fixup. 3186 */ 3187 if (m == NULL) { /* fragment got swallowed */ 3188 retval = IP_FW_DENY; 3189 } else { /* good, packet complete */ 3190 int hlen; 3191 3192 ip = mtod(m, struct ip *); 3193 hlen = ip->ip_hl << 2; 3194 ip->ip_sum = 0; 3195 if (hlen == sizeof(struct ip)) 3196 ip->ip_sum = in_cksum_hdr(ip); 3197 else 3198 ip->ip_sum = in_cksum(m, hlen); 3199 retval = IP_FW_REASS; 3200 args->rule.info = 0; 3201 set_match(args, f_pos, chain); 3202 } 3203 done = 1; /* exit outer loop */ 3204 break; 3205 } 3206 case O_EXTERNAL_ACTION: 3207 l = 0; /* in any case exit inner loop */ 3208 retval = ipfw_run_eaction(chain, args, 3209 cmd, &done); 3210 /* 3211 * If both @retval and @done are zero, 3212 * consider this as rule matching and 3213 * update counters. 3214 */ 3215 if (retval == 0 && done == 0) { 3216 IPFW_INC_RULE_COUNTER(f, pktlen); 3217 /* 3218 * Reset the result of the last 3219 * dynamic state lookup. 3220 * External action can change 3221 * @args content, and it may be 3222 * used for new state lookup later. 3223 */ 3224 DYN_INFO_INIT(&dyn_info); 3225 } 3226 break; 3227 3228 default: 3229 panic("-- unknown opcode %d\n", cmd->opcode); 3230 } /* end of switch() on opcodes */ 3231 /* 3232 * if we get here with l=0, then match is irrelevant. 3233 */ 3234 3235 if (cmd->len & F_NOT) 3236 match = !match; 3237 3238 if (match) { 3239 if (cmd->len & F_OR) 3240 skip_or = 1; 3241 } else { 3242 if (!(cmd->len & F_OR)) /* not an OR block, */ 3243 break; /* try next rule */ 3244 } 3245 3246 } /* end of inner loop, scan opcodes */ 3247 #undef PULLUP_LEN 3248 #undef PULLUP_LEN_LOCKED 3249 3250 if (done) 3251 break; 3252 3253 /* next_rule:; */ /* try next rule */ 3254 3255 } /* end of outer for, scan rules */ 3256 3257 if (done) { 3258 struct ip_fw *rule = chain->map[f_pos]; 3259 /* Update statistics */ 3260 IPFW_INC_RULE_COUNTER(rule, pktlen); 3261 IPFW_PROBE(rule__matched, retval, 3262 is_ipv4 ? AF_INET : AF_INET6, 3263 is_ipv4 ? (uintptr_t)&src_ip : 3264 (uintptr_t)&args->f_id.src_ip6, 3265 is_ipv4 ? (uintptr_t)&dst_ip : 3266 (uintptr_t)&args->f_id.dst_ip6, 3267 args, rule); 3268 } else { 3269 retval = IP_FW_DENY; 3270 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 3271 } 3272 IPFW_PF_RUNLOCK(chain); 3273 #ifdef __FreeBSD__ 3274 if (ucred_cache != NULL) 3275 crfree(ucred_cache); 3276 #endif 3277 return (retval); 3278 3279 pullup_failed: 3280 if (V_fw_verbose) 3281 printf("ipfw: pullup failed\n"); 3282 return (IP_FW_DENY); 3283 } 3284 3285 /* 3286 * Set maximum number of tables that can be used in given VNET ipfw instance. 3287 */ 3288 #ifdef SYSCTL_NODE 3289 static int 3290 sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS) 3291 { 3292 int error; 3293 unsigned int ntables; 3294 3295 ntables = V_fw_tables_max; 3296 3297 error = sysctl_handle_int(oidp, &ntables, 0, req); 3298 /* Read operation or some error */ 3299 if ((error != 0) || (req->newptr == NULL)) 3300 return (error); 3301 3302 return (ipfw_resize_tables(&V_layer3_chain, ntables)); 3303 } 3304 3305 /* 3306 * Switches table namespace between global and per-set. 3307 */ 3308 static int 3309 sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS) 3310 { 3311 int error; 3312 unsigned int sets; 3313 3314 sets = V_fw_tables_sets; 3315 3316 error = sysctl_handle_int(oidp, &sets, 0, req); 3317 /* Read operation or some error */ 3318 if ((error != 0) || (req->newptr == NULL)) 3319 return (error); 3320 3321 return (ipfw_switch_tables_namespace(&V_layer3_chain, sets)); 3322 } 3323 #endif 3324 3325 /* 3326 * Module and VNET glue 3327 */ 3328 3329 /* 3330 * Stuff that must be initialised only on boot or module load 3331 */ 3332 static int 3333 ipfw_init(void) 3334 { 3335 int error = 0; 3336 3337 /* 3338 * Only print out this stuff the first time around, 3339 * when called from the sysinit code. 3340 */ 3341 printf("ipfw2 " 3342 #ifdef INET6 3343 "(+ipv6) " 3344 #endif 3345 "initialized, divert %s, nat %s, " 3346 "default to %s, logging ", 3347 #ifdef IPDIVERT 3348 "enabled", 3349 #else 3350 "loadable", 3351 #endif 3352 #ifdef IPFIREWALL_NAT 3353 "enabled", 3354 #else 3355 "loadable", 3356 #endif 3357 default_to_accept ? "accept" : "deny"); 3358 3359 /* 3360 * Note: V_xxx variables can be accessed here but the vnet specific 3361 * initializer may not have been called yet for the VIMAGE case. 3362 * Tuneables will have been processed. We will print out values for 3363 * the default vnet. 3364 * XXX This should all be rationalized AFTER 8.0 3365 */ 3366 if (V_fw_verbose == 0) 3367 printf("disabled\n"); 3368 else if (V_verbose_limit == 0) 3369 printf("unlimited\n"); 3370 else 3371 printf("limited to %d packets/entry by default\n", 3372 V_verbose_limit); 3373 3374 /* Check user-supplied table count for validness */ 3375 if (default_fw_tables > IPFW_TABLES_MAX) 3376 default_fw_tables = IPFW_TABLES_MAX; 3377 3378 ipfw_init_sopt_handler(); 3379 ipfw_init_obj_rewriter(); 3380 ipfw_iface_init(); 3381 return (error); 3382 } 3383 3384 /* 3385 * Called for the removal of the last instance only on module unload. 3386 */ 3387 static void 3388 ipfw_destroy(void) 3389 { 3390 3391 ipfw_iface_destroy(); 3392 ipfw_destroy_sopt_handler(); 3393 ipfw_destroy_obj_rewriter(); 3394 printf("IP firewall unloaded\n"); 3395 } 3396 3397 /* 3398 * Stuff that must be initialized for every instance 3399 * (including the first of course). 3400 */ 3401 static int 3402 vnet_ipfw_init(const void *unused) 3403 { 3404 int error, first; 3405 struct ip_fw *rule = NULL; 3406 struct ip_fw_chain *chain; 3407 3408 chain = &V_layer3_chain; 3409 3410 first = IS_DEFAULT_VNET(curvnet) ? 1 : 0; 3411 3412 /* First set up some values that are compile time options */ 3413 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 3414 V_fw_deny_unknown_exthdrs = 1; 3415 #ifdef IPFIREWALL_VERBOSE 3416 V_fw_verbose = 1; 3417 #endif 3418 #ifdef IPFIREWALL_VERBOSE_LIMIT 3419 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 3420 #endif 3421 #ifdef IPFIREWALL_NAT 3422 LIST_INIT(&chain->nat); 3423 #endif 3424 3425 /* Init shared services hash table */ 3426 ipfw_init_srv(chain); 3427 3428 ipfw_init_counters(); 3429 /* Set initial number of tables */ 3430 V_fw_tables_max = default_fw_tables; 3431 error = ipfw_init_tables(chain, first); 3432 if (error) { 3433 printf("ipfw2: setting up tables failed\n"); 3434 free(chain->map, M_IPFW); 3435 free(rule, M_IPFW); 3436 return (ENOSPC); 3437 } 3438 3439 IPFW_LOCK_INIT(chain); 3440 3441 /* fill and insert the default rule */ 3442 rule = ipfw_alloc_rule(chain, sizeof(struct ip_fw)); 3443 rule->flags |= IPFW_RULE_NOOPT; 3444 rule->cmd_len = 1; 3445 rule->cmd[0].len = 1; 3446 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY; 3447 chain->default_rule = rule; 3448 ipfw_add_protected_rule(chain, rule, 0); 3449 3450 ipfw_dyn_init(chain); 3451 ipfw_eaction_init(chain, first); 3452 #ifdef LINEAR_SKIPTO 3453 ipfw_init_skipto_cache(chain); 3454 #endif 3455 ipfw_bpf_init(first); 3456 3457 /* First set up some values that are compile time options */ 3458 V_ipfw_vnet_ready = 1; /* Open for business */ 3459 3460 /* 3461 * Hook the sockopt handler and pfil hooks for ipv4 and ipv6. 3462 * Even if the latter two fail we still keep the module alive 3463 * because the sockopt and layer2 paths are still useful. 3464 * ipfw[6]_hook return 0 on success, ENOENT on failure, 3465 * so we can ignore the exact return value and just set a flag. 3466 * 3467 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so 3468 * changes in the underlying (per-vnet) variables trigger 3469 * immediate hook()/unhook() calls. 3470 * In layer2 we have the same behaviour, except that V_ether_ipfw 3471 * is checked on each packet because there are no pfil hooks. 3472 */ 3473 V_ip_fw_ctl_ptr = ipfw_ctl3; 3474 error = ipfw_attach_hooks(); 3475 return (error); 3476 } 3477 3478 /* 3479 * Called for the removal of each instance. 3480 */ 3481 static int 3482 vnet_ipfw_uninit(const void *unused) 3483 { 3484 struct ip_fw *reap; 3485 struct ip_fw_chain *chain = &V_layer3_chain; 3486 int i, last; 3487 3488 V_ipfw_vnet_ready = 0; /* tell new callers to go away */ 3489 /* 3490 * disconnect from ipv4, ipv6, layer2 and sockopt. 3491 * Then grab, release and grab again the WLOCK so we make 3492 * sure the update is propagated and nobody will be in. 3493 */ 3494 ipfw_detach_hooks(); 3495 V_ip_fw_ctl_ptr = NULL; 3496 3497 last = IS_DEFAULT_VNET(curvnet) ? 1 : 0; 3498 3499 IPFW_UH_WLOCK(chain); 3500 IPFW_UH_WUNLOCK(chain); 3501 3502 ipfw_dyn_uninit(0); /* run the callout_drain */ 3503 3504 IPFW_UH_WLOCK(chain); 3505 3506 reap = NULL; 3507 IPFW_WLOCK(chain); 3508 for (i = 0; i < chain->n_rules; i++) 3509 ipfw_reap_add(chain, &reap, chain->map[i]); 3510 free(chain->map, M_IPFW); 3511 #ifdef LINEAR_SKIPTO 3512 ipfw_destroy_skipto_cache(chain); 3513 #endif 3514 IPFW_WUNLOCK(chain); 3515 IPFW_UH_WUNLOCK(chain); 3516 ipfw_destroy_tables(chain, last); 3517 ipfw_eaction_uninit(chain, last); 3518 if (reap != NULL) 3519 ipfw_reap_rules(reap); 3520 vnet_ipfw_iface_destroy(chain); 3521 ipfw_destroy_srv(chain); 3522 IPFW_LOCK_DESTROY(chain); 3523 ipfw_dyn_uninit(1); /* free the remaining parts */ 3524 ipfw_destroy_counters(); 3525 ipfw_bpf_uninit(last); 3526 return (0); 3527 } 3528 3529 /* 3530 * Module event handler. 3531 * In general we have the choice of handling most of these events by the 3532 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to 3533 * use the SYSINIT handlers as they are more capable of expressing the 3534 * flow of control during module and vnet operations, so this is just 3535 * a skeleton. Note there is no SYSINIT equivalent of the module 3536 * SHUTDOWN handler, but we don't have anything to do in that case anyhow. 3537 */ 3538 static int 3539 ipfw_modevent(module_t mod, int type, void *unused) 3540 { 3541 int err = 0; 3542 3543 switch (type) { 3544 case MOD_LOAD: 3545 /* Called once at module load or 3546 * system boot if compiled in. */ 3547 break; 3548 case MOD_QUIESCE: 3549 /* Called before unload. May veto unloading. */ 3550 break; 3551 case MOD_UNLOAD: 3552 /* Called during unload. */ 3553 break; 3554 case MOD_SHUTDOWN: 3555 /* Called during system shutdown. */ 3556 break; 3557 default: 3558 err = EOPNOTSUPP; 3559 break; 3560 } 3561 return err; 3562 } 3563 3564 static moduledata_t ipfwmod = { 3565 "ipfw", 3566 ipfw_modevent, 3567 0 3568 }; 3569 3570 /* Define startup order. */ 3571 #define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_FIREWALL 3572 #define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */ 3573 #define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */ 3574 #define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */ 3575 3576 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER); 3577 FEATURE(ipfw_ctl3, "ipfw new sockopt calls"); 3578 MODULE_VERSION(ipfw, 3); 3579 /* should declare some dependencies here */ 3580 3581 /* 3582 * Starting up. Done in order after ipfwmod() has been called. 3583 * VNET_SYSINIT is also called for each existing vnet and each new vnet. 3584 */ 3585 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 3586 ipfw_init, NULL); 3587 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 3588 vnet_ipfw_init, NULL); 3589 3590 /* 3591 * Closing up shop. These are done in REVERSE ORDER, but still 3592 * after ipfwmod() has been called. Not called on reboot. 3593 * VNET_SYSUNINIT is also called for each exiting vnet as it exits. 3594 * or when the module is unloaded. 3595 */ 3596 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 3597 ipfw_destroy, NULL); 3598 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 3599 vnet_ipfw_uninit, NULL); 3600 /* end of file */ 3601