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/socket.h> 59 #include <sys/socketvar.h> 60 #include <sys/sysctl.h> 61 #include <sys/syslog.h> 62 #include <sys/ucred.h> 63 #include <net/ethernet.h> /* for ETHERTYPE_IP */ 64 #include <net/if.h> 65 #include <net/if_var.h> 66 #include <net/route.h> 67 #include <net/pfil.h> 68 #include <net/vnet.h> 69 70 #include <netpfil/pf/pf_mtag.h> 71 72 #include <netinet/in.h> 73 #include <netinet/in_var.h> 74 #include <netinet/in_pcb.h> 75 #include <netinet/ip.h> 76 #include <netinet/ip_var.h> 77 #include <netinet/ip_icmp.h> 78 #include <netinet/ip_fw.h> 79 #include <netinet/ip_carp.h> 80 #include <netinet/pim.h> 81 #include <netinet/tcp_var.h> 82 #include <netinet/udp.h> 83 #include <netinet/udp_var.h> 84 #include <netinet/sctp.h> 85 #include <netinet/sctp_crc32.h> 86 #include <netinet/sctp_header.h> 87 88 #include <netinet/ip6.h> 89 #include <netinet/icmp6.h> 90 #include <netinet/in_fib.h> 91 #ifdef INET6 92 #include <netinet6/in6_fib.h> 93 #include <netinet6/in6_pcb.h> 94 #include <netinet6/scope6_var.h> 95 #include <netinet6/ip6_var.h> 96 #endif 97 98 #include <net/if_gre.h> /* for struct grehdr */ 99 100 #include <netpfil/ipfw/ip_fw_private.h> 101 102 #include <machine/in_cksum.h> /* XXX for in_cksum */ 103 104 #ifdef MAC 105 #include <security/mac/mac_framework.h> 106 #endif 107 108 /* 109 * static variables followed by global ones. 110 * All ipfw global variables are here. 111 */ 112 113 static VNET_DEFINE(int, fw_deny_unknown_exthdrs); 114 #define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs) 115 116 static VNET_DEFINE(int, fw_permit_single_frag6) = 1; 117 #define V_fw_permit_single_frag6 VNET(fw_permit_single_frag6) 118 119 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 120 static int default_to_accept = 1; 121 #else 122 static int default_to_accept; 123 #endif 124 125 VNET_DEFINE(int, autoinc_step); 126 VNET_DEFINE(int, fw_one_pass) = 1; 127 128 VNET_DEFINE(unsigned int, fw_tables_max); 129 VNET_DEFINE(unsigned int, fw_tables_sets) = 0; /* Don't use set-aware tables */ 130 /* Use 128 tables by default */ 131 static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT; 132 133 #ifndef LINEAR_SKIPTO 134 static int jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 135 int tablearg, int jump_backwards); 136 #define JUMP(ch, f, num, targ, back) jump_fast(ch, f, num, targ, back) 137 #else 138 static int jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num, 139 int tablearg, int jump_backwards); 140 #define JUMP(ch, f, num, targ, back) jump_linear(ch, f, num, targ, back) 141 #endif 142 143 /* 144 * Each rule belongs to one of 32 different sets (0..31). 145 * The variable set_disable contains one bit per set. 146 * If the bit is set, all rules in the corresponding set 147 * are disabled. Set RESVD_SET(31) is reserved for the default rule 148 * and rules that are not deleted by the flush command, 149 * and CANNOT be disabled. 150 * Rules in set RESVD_SET can only be deleted individually. 151 */ 152 VNET_DEFINE(u_int32_t, set_disable); 153 #define V_set_disable VNET(set_disable) 154 155 VNET_DEFINE(int, fw_verbose); 156 /* counter for ipfw_log(NULL...) */ 157 VNET_DEFINE(u_int64_t, norule_counter); 158 VNET_DEFINE(int, verbose_limit); 159 160 /* layer3_chain contains the list of rules for layer 3 */ 161 VNET_DEFINE(struct ip_fw_chain, layer3_chain); 162 163 /* ipfw_vnet_ready controls when we are open for business */ 164 VNET_DEFINE(int, ipfw_vnet_ready) = 0; 165 166 VNET_DEFINE(int, ipfw_nat_ready) = 0; 167 168 ipfw_nat_t *ipfw_nat_ptr = NULL; 169 struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int); 170 ipfw_nat_cfg_t *ipfw_nat_cfg_ptr; 171 ipfw_nat_cfg_t *ipfw_nat_del_ptr; 172 ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr; 173 ipfw_nat_cfg_t *ipfw_nat_get_log_ptr; 174 175 #ifdef SYSCTL_NODE 176 uint32_t dummy_def = IPFW_DEFAULT_RULE; 177 static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS); 178 static int sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS); 179 180 SYSBEGIN(f3) 181 182 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 183 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 184 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0, 185 "Only do a single pass through ipfw when using dummynet(4)"); 186 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, 187 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(autoinc_step), 0, 188 "Rule number auto-increment step"); 189 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, 190 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0, 191 "Log matches to ipfw rules"); 192 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, 193 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(verbose_limit), 0, 194 "Set upper limit of matches of ipfw rules logged"); 195 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD, 196 &dummy_def, 0, 197 "The default/max possible rule number."); 198 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_max, 199 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, 0, 0, sysctl_ipfw_table_num, "IU", 200 "Maximum number of concurrently used tables"); 201 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_sets, 202 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, 203 0, 0, sysctl_ipfw_tables_sets, "IU", 204 "Use per-set namespace for tables"); 205 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN, 206 &default_to_accept, 0, 207 "Make the default rule accept all packets."); 208 TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables); 209 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, 210 CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0, 211 "Number of static rules"); 212 213 #ifdef INET6 214 SYSCTL_DECL(_net_inet6_ip6); 215 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 216 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs, 217 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE, 218 &VNET_NAME(fw_deny_unknown_exthdrs), 0, 219 "Deny packets with unknown IPv6 Extension Headers"); 220 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6, 221 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE, 222 &VNET_NAME(fw_permit_single_frag6), 0, 223 "Permit single packet IPv6 fragments"); 224 #endif /* INET6 */ 225 226 SYSEND 227 228 #endif /* SYSCTL_NODE */ 229 230 231 /* 232 * Some macros used in the various matching options. 233 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 234 * Other macros just cast void * into the appropriate type 235 */ 236 #define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 237 #define TCP(p) ((struct tcphdr *)(p)) 238 #define SCTP(p) ((struct sctphdr *)(p)) 239 #define UDP(p) ((struct udphdr *)(p)) 240 #define ICMP(p) ((struct icmphdr *)(p)) 241 #define ICMP6(p) ((struct icmp6_hdr *)(p)) 242 243 static __inline int 244 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 245 { 246 int type = icmp->icmp_type; 247 248 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 249 } 250 251 #define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 252 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 253 254 static int 255 is_icmp_query(struct icmphdr *icmp) 256 { 257 int type = icmp->icmp_type; 258 259 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 260 } 261 #undef TT 262 263 /* 264 * The following checks use two arrays of 8 or 16 bits to store the 265 * bits that we want set or clear, respectively. They are in the 266 * low and high half of cmd->arg1 or cmd->d[0]. 267 * 268 * We scan options and store the bits we find set. We succeed if 269 * 270 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 271 * 272 * The code is sometimes optimized not to store additional variables. 273 */ 274 275 static int 276 flags_match(ipfw_insn *cmd, u_int8_t bits) 277 { 278 u_char want_clear; 279 bits = ~bits; 280 281 if ( ((cmd->arg1 & 0xff) & bits) != 0) 282 return 0; /* some bits we want set were clear */ 283 want_clear = (cmd->arg1 >> 8) & 0xff; 284 if ( (want_clear & bits) != want_clear) 285 return 0; /* some bits we want clear were set */ 286 return 1; 287 } 288 289 static int 290 ipopts_match(struct ip *ip, ipfw_insn *cmd) 291 { 292 int optlen, bits = 0; 293 u_char *cp = (u_char *)(ip + 1); 294 int x = (ip->ip_hl << 2) - sizeof (struct ip); 295 296 for (; x > 0; x -= optlen, cp += optlen) { 297 int opt = cp[IPOPT_OPTVAL]; 298 299 if (opt == IPOPT_EOL) 300 break; 301 if (opt == IPOPT_NOP) 302 optlen = 1; 303 else { 304 optlen = cp[IPOPT_OLEN]; 305 if (optlen <= 0 || optlen > x) 306 return 0; /* invalid or truncated */ 307 } 308 switch (opt) { 309 310 default: 311 break; 312 313 case IPOPT_LSRR: 314 bits |= IP_FW_IPOPT_LSRR; 315 break; 316 317 case IPOPT_SSRR: 318 bits |= IP_FW_IPOPT_SSRR; 319 break; 320 321 case IPOPT_RR: 322 bits |= IP_FW_IPOPT_RR; 323 break; 324 325 case IPOPT_TS: 326 bits |= IP_FW_IPOPT_TS; 327 break; 328 } 329 } 330 return (flags_match(cmd, bits)); 331 } 332 333 static int 334 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 335 { 336 int optlen, bits = 0; 337 u_char *cp = (u_char *)(tcp + 1); 338 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 339 340 for (; x > 0; x -= optlen, cp += optlen) { 341 int opt = cp[0]; 342 if (opt == TCPOPT_EOL) 343 break; 344 if (opt == TCPOPT_NOP) 345 optlen = 1; 346 else { 347 optlen = cp[1]; 348 if (optlen <= 0) 349 break; 350 } 351 352 switch (opt) { 353 354 default: 355 break; 356 357 case TCPOPT_MAXSEG: 358 bits |= IP_FW_TCPOPT_MSS; 359 break; 360 361 case TCPOPT_WINDOW: 362 bits |= IP_FW_TCPOPT_WINDOW; 363 break; 364 365 case TCPOPT_SACK_PERMITTED: 366 case TCPOPT_SACK: 367 bits |= IP_FW_TCPOPT_SACK; 368 break; 369 370 case TCPOPT_TIMESTAMP: 371 bits |= IP_FW_TCPOPT_TS; 372 break; 373 374 } 375 } 376 return (flags_match(cmd, bits)); 377 } 378 379 static int 380 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain, 381 uint32_t *tablearg) 382 { 383 384 if (ifp == NULL) /* no iface with this packet, match fails */ 385 return (0); 386 387 /* Check by name or by IP address */ 388 if (cmd->name[0] != '\0') { /* match by name */ 389 if (cmd->name[0] == '\1') /* use tablearg to match */ 390 return ipfw_lookup_table(chain, cmd->p.kidx, 0, 391 &ifp->if_index, tablearg); 392 /* Check name */ 393 if (cmd->p.glob) { 394 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 395 return(1); 396 } else { 397 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 398 return(1); 399 } 400 } else { 401 #if !defined(USERSPACE) && defined(__FreeBSD__) /* and OSX too ? */ 402 struct ifaddr *ia; 403 404 if_addr_rlock(ifp); 405 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 406 if (ia->ifa_addr->sa_family != AF_INET) 407 continue; 408 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 409 (ia->ifa_addr))->sin_addr.s_addr) { 410 if_addr_runlock(ifp); 411 return(1); /* match */ 412 } 413 } 414 if_addr_runlock(ifp); 415 #endif /* __FreeBSD__ */ 416 } 417 return(0); /* no match, fail ... */ 418 } 419 420 /* 421 * The verify_path function checks if a route to the src exists and 422 * if it is reachable via ifp (when provided). 423 * 424 * The 'verrevpath' option checks that the interface that an IP packet 425 * arrives on is the same interface that traffic destined for the 426 * packet's source address would be routed out of. 427 * The 'versrcreach' option just checks that the source address is 428 * reachable via any route (except default) in the routing table. 429 * These two are a measure to block forged packets. This is also 430 * commonly known as "anti-spoofing" or Unicast Reverse Path 431 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 432 * is purposely reminiscent of the Cisco IOS command, 433 * 434 * ip verify unicast reverse-path 435 * ip verify unicast source reachable-via any 436 * 437 * which implements the same functionality. But note that the syntax 438 * is misleading, and the check may be performed on all IP packets 439 * whether unicast, multicast, or broadcast. 440 */ 441 static int 442 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib) 443 { 444 #if defined(USERSPACE) || !defined(__FreeBSD__) 445 return 0; 446 #else 447 struct nhop4_basic nh4; 448 449 if (fib4_lookup_nh_basic(fib, src, NHR_IFAIF, 0, &nh4) != 0) 450 return (0); 451 452 /* 453 * If ifp is provided, check for equality with rtentry. 454 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 455 * in order to pass packets injected back by if_simloop(): 456 * routing entry (via lo0) for our own address 457 * may exist, so we need to handle routing assymetry. 458 */ 459 if (ifp != NULL && ifp != nh4.nh_ifp) 460 return (0); 461 462 /* if no ifp provided, check if rtentry is not default route */ 463 if (ifp == NULL && (nh4.nh_flags & NHF_DEFAULT) != 0) 464 return (0); 465 466 /* or if this is a blackhole/reject route */ 467 if (ifp == NULL && (nh4.nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0) 468 return (0); 469 470 /* found valid route */ 471 return 1; 472 #endif /* __FreeBSD__ */ 473 } 474 475 /* 476 * Generate an SCTP packet containing an ABORT chunk. The verification tag 477 * is given by vtag. The T-bit is set in the ABORT chunk if and only if 478 * reflected is not 0. 479 */ 480 481 static struct mbuf * 482 ipfw_send_abort(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t vtag, 483 int reflected) 484 { 485 struct mbuf *m; 486 struct ip *ip; 487 #ifdef INET6 488 struct ip6_hdr *ip6; 489 #endif 490 struct sctphdr *sctp; 491 struct sctp_chunkhdr *chunk; 492 u_int16_t hlen, plen, tlen; 493 494 MGETHDR(m, M_NOWAIT, MT_DATA); 495 if (m == NULL) 496 return (NULL); 497 498 M_SETFIB(m, id->fib); 499 #ifdef MAC 500 if (replyto != NULL) 501 mac_netinet_firewall_reply(replyto, m); 502 else 503 mac_netinet_firewall_send(m); 504 #else 505 (void)replyto; /* don't warn about unused arg */ 506 #endif 507 508 switch (id->addr_type) { 509 case 4: 510 hlen = sizeof(struct ip); 511 break; 512 #ifdef INET6 513 case 6: 514 hlen = sizeof(struct ip6_hdr); 515 break; 516 #endif 517 default: 518 /* XXX: log me?!? */ 519 FREE_PKT(m); 520 return (NULL); 521 } 522 plen = sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr); 523 tlen = hlen + plen; 524 m->m_data += max_linkhdr; 525 m->m_flags |= M_SKIP_FIREWALL; 526 m->m_pkthdr.len = m->m_len = tlen; 527 m->m_pkthdr.rcvif = NULL; 528 bzero(m->m_data, tlen); 529 530 switch (id->addr_type) { 531 case 4: 532 ip = mtod(m, struct ip *); 533 534 ip->ip_v = 4; 535 ip->ip_hl = sizeof(struct ip) >> 2; 536 ip->ip_tos = IPTOS_LOWDELAY; 537 ip->ip_len = htons(tlen); 538 ip->ip_id = htons(0); 539 ip->ip_off = htons(0); 540 ip->ip_ttl = V_ip_defttl; 541 ip->ip_p = IPPROTO_SCTP; 542 ip->ip_sum = 0; 543 ip->ip_src.s_addr = htonl(id->dst_ip); 544 ip->ip_dst.s_addr = htonl(id->src_ip); 545 546 sctp = (struct sctphdr *)(ip + 1); 547 break; 548 #ifdef INET6 549 case 6: 550 ip6 = mtod(m, struct ip6_hdr *); 551 552 ip6->ip6_vfc = IPV6_VERSION; 553 ip6->ip6_plen = htons(plen); 554 ip6->ip6_nxt = IPPROTO_SCTP; 555 ip6->ip6_hlim = IPV6_DEFHLIM; 556 ip6->ip6_src = id->dst_ip6; 557 ip6->ip6_dst = id->src_ip6; 558 559 sctp = (struct sctphdr *)(ip6 + 1); 560 break; 561 #endif 562 } 563 564 sctp->src_port = htons(id->dst_port); 565 sctp->dest_port = htons(id->src_port); 566 sctp->v_tag = htonl(vtag); 567 sctp->checksum = htonl(0); 568 569 chunk = (struct sctp_chunkhdr *)(sctp + 1); 570 chunk->chunk_type = SCTP_ABORT_ASSOCIATION; 571 chunk->chunk_flags = 0; 572 if (reflected != 0) { 573 chunk->chunk_flags |= SCTP_HAD_NO_TCB; 574 } 575 chunk->chunk_length = htons(sizeof(struct sctp_chunkhdr)); 576 577 sctp->checksum = sctp_calculate_cksum(m, hlen); 578 579 return (m); 580 } 581 582 /* 583 * Generate a TCP packet, containing either a RST or a keepalive. 584 * When flags & TH_RST, we are sending a RST packet, because of a 585 * "reset" action matched the packet. 586 * Otherwise we are sending a keepalive, and flags & TH_ 587 * The 'replyto' mbuf is the mbuf being replied to, if any, and is required 588 * so that MAC can label the reply appropriately. 589 */ 590 struct mbuf * 591 ipfw_send_pkt(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t seq, 592 u_int32_t ack, int flags) 593 { 594 struct mbuf *m = NULL; /* stupid compiler */ 595 struct ip *h = NULL; /* stupid compiler */ 596 #ifdef INET6 597 struct ip6_hdr *h6 = NULL; 598 #endif 599 struct tcphdr *th = NULL; 600 int len, dir; 601 602 MGETHDR(m, M_NOWAIT, MT_DATA); 603 if (m == NULL) 604 return (NULL); 605 606 M_SETFIB(m, id->fib); 607 #ifdef MAC 608 if (replyto != NULL) 609 mac_netinet_firewall_reply(replyto, m); 610 else 611 mac_netinet_firewall_send(m); 612 #else 613 (void)replyto; /* don't warn about unused arg */ 614 #endif 615 616 switch (id->addr_type) { 617 case 4: 618 len = sizeof(struct ip) + sizeof(struct tcphdr); 619 break; 620 #ifdef INET6 621 case 6: 622 len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 623 break; 624 #endif 625 default: 626 /* XXX: log me?!? */ 627 FREE_PKT(m); 628 return (NULL); 629 } 630 dir = ((flags & (TH_SYN | TH_RST)) == TH_SYN); 631 632 m->m_data += max_linkhdr; 633 m->m_flags |= M_SKIP_FIREWALL; 634 m->m_pkthdr.len = m->m_len = len; 635 m->m_pkthdr.rcvif = NULL; 636 bzero(m->m_data, len); 637 638 switch (id->addr_type) { 639 case 4: 640 h = mtod(m, struct ip *); 641 642 /* prepare for checksum */ 643 h->ip_p = IPPROTO_TCP; 644 h->ip_len = htons(sizeof(struct tcphdr)); 645 if (dir) { 646 h->ip_src.s_addr = htonl(id->src_ip); 647 h->ip_dst.s_addr = htonl(id->dst_ip); 648 } else { 649 h->ip_src.s_addr = htonl(id->dst_ip); 650 h->ip_dst.s_addr = htonl(id->src_ip); 651 } 652 653 th = (struct tcphdr *)(h + 1); 654 break; 655 #ifdef INET6 656 case 6: 657 h6 = mtod(m, struct ip6_hdr *); 658 659 /* prepare for checksum */ 660 h6->ip6_nxt = IPPROTO_TCP; 661 h6->ip6_plen = htons(sizeof(struct tcphdr)); 662 if (dir) { 663 h6->ip6_src = id->src_ip6; 664 h6->ip6_dst = id->dst_ip6; 665 } else { 666 h6->ip6_src = id->dst_ip6; 667 h6->ip6_dst = id->src_ip6; 668 } 669 670 th = (struct tcphdr *)(h6 + 1); 671 break; 672 #endif 673 } 674 675 if (dir) { 676 th->th_sport = htons(id->src_port); 677 th->th_dport = htons(id->dst_port); 678 } else { 679 th->th_sport = htons(id->dst_port); 680 th->th_dport = htons(id->src_port); 681 } 682 th->th_off = sizeof(struct tcphdr) >> 2; 683 684 if (flags & TH_RST) { 685 if (flags & TH_ACK) { 686 th->th_seq = htonl(ack); 687 th->th_flags = TH_RST; 688 } else { 689 if (flags & TH_SYN) 690 seq++; 691 th->th_ack = htonl(seq); 692 th->th_flags = TH_RST | TH_ACK; 693 } 694 } else { 695 /* 696 * Keepalive - use caller provided sequence numbers 697 */ 698 th->th_seq = htonl(seq); 699 th->th_ack = htonl(ack); 700 th->th_flags = TH_ACK; 701 } 702 703 switch (id->addr_type) { 704 case 4: 705 th->th_sum = in_cksum(m, len); 706 707 /* finish the ip header */ 708 h->ip_v = 4; 709 h->ip_hl = sizeof(*h) >> 2; 710 h->ip_tos = IPTOS_LOWDELAY; 711 h->ip_off = htons(0); 712 h->ip_len = htons(len); 713 h->ip_ttl = V_ip_defttl; 714 h->ip_sum = 0; 715 break; 716 #ifdef INET6 717 case 6: 718 th->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(*h6), 719 sizeof(struct tcphdr)); 720 721 /* finish the ip6 header */ 722 h6->ip6_vfc |= IPV6_VERSION; 723 h6->ip6_hlim = IPV6_DEFHLIM; 724 break; 725 #endif 726 } 727 728 return (m); 729 } 730 731 #ifdef INET6 732 /* 733 * ipv6 specific rules here... 734 */ 735 static __inline int 736 icmp6type_match (int type, ipfw_insn_u32 *cmd) 737 { 738 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 739 } 740 741 static int 742 flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 743 { 744 int i; 745 for (i=0; i <= cmd->o.arg1; ++i ) 746 if (curr_flow == cmd->d[i] ) 747 return 1; 748 return 0; 749 } 750 751 /* support for IP6_*_ME opcodes */ 752 static const struct in6_addr lla_mask = {{{ 753 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 754 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff 755 }}}; 756 757 static int 758 ipfw_localip6(struct in6_addr *in6) 759 { 760 struct rm_priotracker in6_ifa_tracker; 761 struct in6_ifaddr *ia; 762 763 if (IN6_IS_ADDR_MULTICAST(in6)) 764 return (0); 765 766 if (!IN6_IS_ADDR_LINKLOCAL(in6)) 767 return (in6_localip(in6)); 768 769 IN6_IFADDR_RLOCK(&in6_ifa_tracker); 770 TAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) { 771 if (!IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) 772 continue; 773 if (IN6_ARE_MASKED_ADDR_EQUAL(&ia->ia_addr.sin6_addr, 774 in6, &lla_mask)) { 775 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 776 return (1); 777 } 778 } 779 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 780 return (0); 781 } 782 783 static int 784 verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib) 785 { 786 struct nhop6_basic nh6; 787 788 if (IN6_IS_SCOPE_LINKLOCAL(src)) 789 return (1); 790 791 if (fib6_lookup_nh_basic(fib, src, 0, NHR_IFAIF, 0, &nh6) != 0) 792 return (0); 793 794 /* If ifp is provided, check for equality with route table. */ 795 if (ifp != NULL && ifp != nh6.nh_ifp) 796 return (0); 797 798 /* if no ifp provided, check if rtentry is not default route */ 799 if (ifp == NULL && (nh6.nh_flags & NHF_DEFAULT) != 0) 800 return (0); 801 802 /* or if this is a blackhole/reject route */ 803 if (ifp == NULL && (nh6.nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0) 804 return (0); 805 806 /* found valid route */ 807 return 1; 808 } 809 810 static int 811 is_icmp6_query(int icmp6_type) 812 { 813 if ((icmp6_type <= ICMP6_MAXTYPE) && 814 (icmp6_type == ICMP6_ECHO_REQUEST || 815 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 816 icmp6_type == ICMP6_WRUREQUEST || 817 icmp6_type == ICMP6_FQDN_QUERY || 818 icmp6_type == ICMP6_NI_QUERY)) 819 return (1); 820 821 return (0); 822 } 823 824 static void 825 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 826 { 827 struct mbuf *m; 828 829 m = args->m; 830 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 831 struct tcphdr *tcp; 832 tcp = (struct tcphdr *)((char *)ip6 + hlen); 833 834 if ((tcp->th_flags & TH_RST) == 0) { 835 struct mbuf *m0; 836 m0 = ipfw_send_pkt(args->m, &(args->f_id), 837 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 838 tcp->th_flags | TH_RST); 839 if (m0 != NULL) 840 ip6_output(m0, NULL, NULL, 0, NULL, NULL, 841 NULL); 842 } 843 FREE_PKT(m); 844 } else if (code == ICMP6_UNREACH_ABORT && 845 args->f_id.proto == IPPROTO_SCTP) { 846 struct mbuf *m0; 847 struct sctphdr *sctp; 848 u_int32_t v_tag; 849 int reflected; 850 851 sctp = (struct sctphdr *)((char *)ip6 + hlen); 852 reflected = 1; 853 v_tag = ntohl(sctp->v_tag); 854 /* Investigate the first chunk header if available */ 855 if (m->m_len >= hlen + sizeof(struct sctphdr) + 856 sizeof(struct sctp_chunkhdr)) { 857 struct sctp_chunkhdr *chunk; 858 859 chunk = (struct sctp_chunkhdr *)(sctp + 1); 860 switch (chunk->chunk_type) { 861 case SCTP_INITIATION: 862 /* 863 * Packets containing an INIT chunk MUST have 864 * a zero v-tag. 865 */ 866 if (v_tag != 0) { 867 v_tag = 0; 868 break; 869 } 870 /* INIT chunk MUST NOT be bundled */ 871 if (m->m_pkthdr.len > 872 hlen + sizeof(struct sctphdr) + 873 ntohs(chunk->chunk_length) + 3) { 874 break; 875 } 876 /* Use the initiate tag if available */ 877 if ((m->m_len >= hlen + sizeof(struct sctphdr) + 878 sizeof(struct sctp_chunkhdr) + 879 offsetof(struct sctp_init, a_rwnd))) { 880 struct sctp_init *init; 881 882 init = (struct sctp_init *)(chunk + 1); 883 v_tag = ntohl(init->initiate_tag); 884 reflected = 0; 885 } 886 break; 887 case SCTP_ABORT_ASSOCIATION: 888 /* 889 * If the packet contains an ABORT chunk, don't 890 * reply. 891 * XXX: We should search through all chunks, 892 * but don't do to avoid attacks. 893 */ 894 v_tag = 0; 895 break; 896 } 897 } 898 if (v_tag == 0) { 899 m0 = NULL; 900 } else { 901 m0 = ipfw_send_abort(args->m, &(args->f_id), v_tag, 902 reflected); 903 } 904 if (m0 != NULL) 905 ip6_output(m0, NULL, NULL, 0, NULL, NULL, NULL); 906 FREE_PKT(m); 907 } else if (code != ICMP6_UNREACH_RST && code != ICMP6_UNREACH_ABORT) { 908 /* Send an ICMPv6 unreach. */ 909 #if 0 910 /* 911 * Unlike above, the mbufs need to line up with the ip6 hdr, 912 * as the contents are read. We need to m_adj() the 913 * needed amount. 914 * The mbuf will however be thrown away so we can adjust it. 915 * Remember we did an m_pullup on it already so we 916 * can make some assumptions about contiguousness. 917 */ 918 if (args->L3offset) 919 m_adj(m, args->L3offset); 920 #endif 921 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 922 } else 923 FREE_PKT(m); 924 925 args->m = NULL; 926 } 927 928 #endif /* INET6 */ 929 930 931 /* 932 * sends a reject message, consuming the mbuf passed as an argument. 933 */ 934 static void 935 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip) 936 { 937 938 #if 0 939 /* XXX When ip is not guaranteed to be at mtod() we will 940 * need to account for this */ 941 * The mbuf will however be thrown away so we can adjust it. 942 * Remember we did an m_pullup on it already so we 943 * can make some assumptions about contiguousness. 944 */ 945 if (args->L3offset) 946 m_adj(m, args->L3offset); 947 #endif 948 if (code != ICMP_REJECT_RST && code != ICMP_REJECT_ABORT) { 949 /* Send an ICMP unreach */ 950 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 951 } else if (code == ICMP_REJECT_RST && args->f_id.proto == IPPROTO_TCP) { 952 struct tcphdr *const tcp = 953 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 954 if ( (tcp->th_flags & TH_RST) == 0) { 955 struct mbuf *m; 956 m = ipfw_send_pkt(args->m, &(args->f_id), 957 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 958 tcp->th_flags | TH_RST); 959 if (m != NULL) 960 ip_output(m, NULL, NULL, 0, NULL, NULL); 961 } 962 FREE_PKT(args->m); 963 } else if (code == ICMP_REJECT_ABORT && 964 args->f_id.proto == IPPROTO_SCTP) { 965 struct mbuf *m; 966 struct sctphdr *sctp; 967 struct sctp_chunkhdr *chunk; 968 struct sctp_init *init; 969 u_int32_t v_tag; 970 int reflected; 971 972 sctp = L3HDR(struct sctphdr, mtod(args->m, struct ip *)); 973 reflected = 1; 974 v_tag = ntohl(sctp->v_tag); 975 if (iplen >= (ip->ip_hl << 2) + sizeof(struct sctphdr) + 976 sizeof(struct sctp_chunkhdr)) { 977 /* Look at the first chunk header if available */ 978 chunk = (struct sctp_chunkhdr *)(sctp + 1); 979 switch (chunk->chunk_type) { 980 case SCTP_INITIATION: 981 /* 982 * Packets containing an INIT chunk MUST have 983 * a zero v-tag. 984 */ 985 if (v_tag != 0) { 986 v_tag = 0; 987 break; 988 } 989 /* INIT chunk MUST NOT be bundled */ 990 if (iplen > 991 (ip->ip_hl << 2) + sizeof(struct sctphdr) + 992 ntohs(chunk->chunk_length) + 3) { 993 break; 994 } 995 /* Use the initiate tag if available */ 996 if ((iplen >= (ip->ip_hl << 2) + 997 sizeof(struct sctphdr) + 998 sizeof(struct sctp_chunkhdr) + 999 offsetof(struct sctp_init, a_rwnd))) { 1000 init = (struct sctp_init *)(chunk + 1); 1001 v_tag = ntohl(init->initiate_tag); 1002 reflected = 0; 1003 } 1004 break; 1005 case SCTP_ABORT_ASSOCIATION: 1006 /* 1007 * If the packet contains an ABORT chunk, don't 1008 * reply. 1009 * XXX: We should search through all chunks, 1010 * but don't do to avoid attacks. 1011 */ 1012 v_tag = 0; 1013 break; 1014 } 1015 } 1016 if (v_tag == 0) { 1017 m = NULL; 1018 } else { 1019 m = ipfw_send_abort(args->m, &(args->f_id), v_tag, 1020 reflected); 1021 } 1022 if (m != NULL) 1023 ip_output(m, NULL, NULL, 0, NULL, NULL); 1024 FREE_PKT(args->m); 1025 } else 1026 FREE_PKT(args->m); 1027 args->m = NULL; 1028 } 1029 1030 /* 1031 * Support for uid/gid/jail lookup. These tests are expensive 1032 * (because we may need to look into the list of active sockets) 1033 * so we cache the results. ugid_lookupp is 0 if we have not 1034 * yet done a lookup, 1 if we succeeded, and -1 if we tried 1035 * and failed. The function always returns the match value. 1036 * We could actually spare the variable and use *uc, setting 1037 * it to '(void *)check_uidgid if we have no info, NULL if 1038 * we tried and failed, or any other value if successful. 1039 */ 1040 static int 1041 check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp, 1042 struct ucred **uc) 1043 { 1044 #if defined(USERSPACE) 1045 return 0; // not supported in userspace 1046 #else 1047 #ifndef __FreeBSD__ 1048 /* XXX */ 1049 return cred_check(insn, proto, oif, 1050 dst_ip, dst_port, src_ip, src_port, 1051 (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb); 1052 #else /* FreeBSD */ 1053 struct in_addr src_ip, dst_ip; 1054 struct inpcbinfo *pi; 1055 struct ipfw_flow_id *id; 1056 struct inpcb *pcb, *inp; 1057 struct ifnet *oif; 1058 int lookupflags; 1059 int match; 1060 1061 id = &args->f_id; 1062 inp = args->inp; 1063 oif = args->oif; 1064 1065 /* 1066 * Check to see if the UDP or TCP stack supplied us with 1067 * the PCB. If so, rather then holding a lock and looking 1068 * up the PCB, we can use the one that was supplied. 1069 */ 1070 if (inp && *ugid_lookupp == 0) { 1071 INP_LOCK_ASSERT(inp); 1072 if (inp->inp_socket != NULL) { 1073 *uc = crhold(inp->inp_cred); 1074 *ugid_lookupp = 1; 1075 } else 1076 *ugid_lookupp = -1; 1077 } 1078 /* 1079 * If we have already been here and the packet has no 1080 * PCB entry associated with it, then we can safely 1081 * assume that this is a no match. 1082 */ 1083 if (*ugid_lookupp == -1) 1084 return (0); 1085 if (id->proto == IPPROTO_TCP) { 1086 lookupflags = 0; 1087 pi = &V_tcbinfo; 1088 } else if (id->proto == IPPROTO_UDP) { 1089 lookupflags = INPLOOKUP_WILDCARD; 1090 pi = &V_udbinfo; 1091 } else if (id->proto == IPPROTO_UDPLITE) { 1092 lookupflags = INPLOOKUP_WILDCARD; 1093 pi = &V_ulitecbinfo; 1094 } else 1095 return 0; 1096 lookupflags |= INPLOOKUP_RLOCKPCB; 1097 match = 0; 1098 if (*ugid_lookupp == 0) { 1099 if (id->addr_type == 6) { 1100 #ifdef INET6 1101 if (oif == NULL) 1102 pcb = in6_pcblookup_mbuf(pi, 1103 &id->src_ip6, htons(id->src_port), 1104 &id->dst_ip6, htons(id->dst_port), 1105 lookupflags, oif, args->m); 1106 else 1107 pcb = in6_pcblookup_mbuf(pi, 1108 &id->dst_ip6, htons(id->dst_port), 1109 &id->src_ip6, htons(id->src_port), 1110 lookupflags, oif, args->m); 1111 #else 1112 *ugid_lookupp = -1; 1113 return (0); 1114 #endif 1115 } else { 1116 src_ip.s_addr = htonl(id->src_ip); 1117 dst_ip.s_addr = htonl(id->dst_ip); 1118 if (oif == NULL) 1119 pcb = in_pcblookup_mbuf(pi, 1120 src_ip, htons(id->src_port), 1121 dst_ip, htons(id->dst_port), 1122 lookupflags, oif, args->m); 1123 else 1124 pcb = in_pcblookup_mbuf(pi, 1125 dst_ip, htons(id->dst_port), 1126 src_ip, htons(id->src_port), 1127 lookupflags, oif, args->m); 1128 } 1129 if (pcb != NULL) { 1130 INP_RLOCK_ASSERT(pcb); 1131 *uc = crhold(pcb->inp_cred); 1132 *ugid_lookupp = 1; 1133 INP_RUNLOCK(pcb); 1134 } 1135 if (*ugid_lookupp == 0) { 1136 /* 1137 * We tried and failed, set the variable to -1 1138 * so we will not try again on this packet. 1139 */ 1140 *ugid_lookupp = -1; 1141 return (0); 1142 } 1143 } 1144 if (insn->o.opcode == O_UID) 1145 match = ((*uc)->cr_uid == (uid_t)insn->d[0]); 1146 else if (insn->o.opcode == O_GID) 1147 match = groupmember((gid_t)insn->d[0], *uc); 1148 else if (insn->o.opcode == O_JAIL) 1149 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]); 1150 return (match); 1151 #endif /* __FreeBSD__ */ 1152 #endif /* not supported in userspace */ 1153 } 1154 1155 /* 1156 * Helper function to set args with info on the rule after the matching 1157 * one. slot is precise, whereas we guess rule_id as they are 1158 * assigned sequentially. 1159 */ 1160 static inline void 1161 set_match(struct ip_fw_args *args, int slot, 1162 struct ip_fw_chain *chain) 1163 { 1164 args->rule.chain_id = chain->id; 1165 args->rule.slot = slot + 1; /* we use 0 as a marker */ 1166 args->rule.rule_id = 1 + chain->map[slot]->id; 1167 args->rule.rulenum = chain->map[slot]->rulenum; 1168 } 1169 1170 #ifndef LINEAR_SKIPTO 1171 /* 1172 * Helper function to enable cached rule lookups using 1173 * cached_id and cached_pos fields in ipfw rule. 1174 */ 1175 static int 1176 jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 1177 int tablearg, int jump_backwards) 1178 { 1179 int f_pos; 1180 1181 /* If possible use cached f_pos (in f->cached_pos), 1182 * whose version is written in f->cached_id 1183 * (horrible hacks to avoid changing the ABI). 1184 */ 1185 if (num != IP_FW_TARG && f->cached_id == chain->id) 1186 f_pos = f->cached_pos; 1187 else { 1188 int i = IP_FW_ARG_TABLEARG(chain, num, skipto); 1189 /* make sure we do not jump backward */ 1190 if (jump_backwards == 0 && i <= f->rulenum) 1191 i = f->rulenum + 1; 1192 if (chain->idxmap != NULL) 1193 f_pos = chain->idxmap[i]; 1194 else 1195 f_pos = ipfw_find_rule(chain, i, 0); 1196 /* update the cache */ 1197 if (num != IP_FW_TARG) { 1198 f->cached_id = chain->id; 1199 f->cached_pos = f_pos; 1200 } 1201 } 1202 1203 return (f_pos); 1204 } 1205 #else 1206 /* 1207 * Helper function to enable real fast rule lookups. 1208 */ 1209 static int 1210 jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num, 1211 int tablearg, int jump_backwards) 1212 { 1213 int f_pos; 1214 1215 num = IP_FW_ARG_TABLEARG(chain, num, skipto); 1216 /* make sure we do not jump backward */ 1217 if (jump_backwards == 0 && num <= f->rulenum) 1218 num = f->rulenum + 1; 1219 f_pos = chain->idxmap[num]; 1220 1221 return (f_pos); 1222 } 1223 #endif 1224 1225 #define TARG(k, f) IP_FW_ARG_TABLEARG(chain, k, f) 1226 /* 1227 * The main check routine for the firewall. 1228 * 1229 * All arguments are in args so we can modify them and return them 1230 * back to the caller. 1231 * 1232 * Parameters: 1233 * 1234 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 1235 * Starts with the IP header. 1236 * args->eh (in) Mac header if present, NULL for layer3 packet. 1237 * args->L3offset Number of bytes bypassed if we came from L2. 1238 * e.g. often sizeof(eh) ** NOTYET ** 1239 * args->oif Outgoing interface, NULL if packet is incoming. 1240 * The incoming interface is in the mbuf. (in) 1241 * args->divert_rule (in/out) 1242 * Skip up to the first rule past this rule number; 1243 * upon return, non-zero port number for divert or tee. 1244 * 1245 * args->rule Pointer to the last matching rule (in/out) 1246 * args->next_hop Socket we are forwarding to (out). 1247 * args->next_hop6 IPv6 next hop we are forwarding to (out). 1248 * args->f_id Addresses grabbed from the packet (out) 1249 * args->rule.info a cookie depending on rule action 1250 * 1251 * Return value: 1252 * 1253 * IP_FW_PASS the packet must be accepted 1254 * IP_FW_DENY the packet must be dropped 1255 * IP_FW_DIVERT divert packet, port in m_tag 1256 * IP_FW_TEE tee packet, port in m_tag 1257 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 1258 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 1259 * args->rule contains the matching rule, 1260 * args->rule.info has additional information. 1261 * 1262 */ 1263 int 1264 ipfw_chk(struct ip_fw_args *args) 1265 { 1266 1267 /* 1268 * Local variables holding state while processing a packet: 1269 * 1270 * IMPORTANT NOTE: to speed up the processing of rules, there 1271 * are some assumption on the values of the variables, which 1272 * are documented here. Should you change them, please check 1273 * the implementation of the various instructions to make sure 1274 * that they still work. 1275 * 1276 * args->eh The MAC header. It is non-null for a layer2 1277 * packet, it is NULL for a layer-3 packet. 1278 * **notyet** 1279 * args->L3offset Offset in the packet to the L3 (IP or equiv.) header. 1280 * 1281 * m | args->m Pointer to the mbuf, as received from the caller. 1282 * It may change if ipfw_chk() does an m_pullup, or if it 1283 * consumes the packet because it calls send_reject(). 1284 * XXX This has to change, so that ipfw_chk() never modifies 1285 * or consumes the buffer. 1286 * ip is the beginning of the ip(4 or 6) header. 1287 * Calculated by adding the L3offset to the start of data. 1288 * (Until we start using L3offset, the packet is 1289 * supposed to start with the ip header). 1290 */ 1291 struct mbuf *m = args->m; 1292 struct ip *ip = mtod(m, struct ip *); 1293 1294 /* 1295 * For rules which contain uid/gid or jail constraints, cache 1296 * a copy of the users credentials after the pcb lookup has been 1297 * executed. This will speed up the processing of rules with 1298 * these types of constraints, as well as decrease contention 1299 * on pcb related locks. 1300 */ 1301 #ifndef __FreeBSD__ 1302 struct bsd_ucred ucred_cache; 1303 #else 1304 struct ucred *ucred_cache = NULL; 1305 #endif 1306 int ucred_lookup = 0; 1307 1308 /* 1309 * oif | args->oif If NULL, ipfw_chk has been called on the 1310 * inbound path (ether_input, ip_input). 1311 * If non-NULL, ipfw_chk has been called on the outbound path 1312 * (ether_output, ip_output). 1313 */ 1314 struct ifnet *oif = args->oif; 1315 1316 int f_pos = 0; /* index of current rule in the array */ 1317 int retval = 0; 1318 1319 /* 1320 * hlen The length of the IP header. 1321 */ 1322 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 1323 1324 /* 1325 * offset The offset of a fragment. offset != 0 means that 1326 * we have a fragment at this offset of an IPv4 packet. 1327 * offset == 0 means that (if this is an IPv4 packet) 1328 * this is the first or only fragment. 1329 * For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header 1330 * or there is a single packet fragment (fragment header added 1331 * without needed). We will treat a single packet fragment as if 1332 * there was no fragment header (or log/block depending on the 1333 * V_fw_permit_single_frag6 sysctl setting). 1334 */ 1335 u_short offset = 0; 1336 u_short ip6f_mf = 0; 1337 1338 /* 1339 * Local copies of addresses. They are only valid if we have 1340 * an IP packet. 1341 * 1342 * proto The protocol. Set to 0 for non-ip packets, 1343 * or to the protocol read from the packet otherwise. 1344 * proto != 0 means that we have an IPv4 packet. 1345 * 1346 * src_port, dst_port port numbers, in HOST format. Only 1347 * valid for TCP and UDP packets. 1348 * 1349 * src_ip, dst_ip ip addresses, in NETWORK format. 1350 * Only valid for IPv4 packets. 1351 */ 1352 uint8_t proto; 1353 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 1354 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 1355 int iplen = 0; 1356 int pktlen; 1357 uint16_t etype = 0; /* Host order stored ether type */ 1358 1359 /* 1360 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 1361 * MATCH_NONE when checked and not matched (q = NULL), 1362 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) 1363 */ 1364 int dyn_dir = MATCH_UNKNOWN; 1365 uint16_t dyn_name = 0; 1366 struct ip_fw *q = NULL; 1367 struct ip_fw_chain *chain = &V_layer3_chain; 1368 1369 /* 1370 * We store in ulp a pointer to the upper layer protocol header. 1371 * In the ipv4 case this is easy to determine from the header, 1372 * but for ipv6 we might have some additional headers in the middle. 1373 * ulp is NULL if not found. 1374 */ 1375 void *ulp = NULL; /* upper layer protocol pointer. */ 1376 1377 /* XXX ipv6 variables */ 1378 int is_ipv6 = 0; 1379 uint8_t icmp6_type = 0; 1380 uint16_t ext_hd = 0; /* bits vector for extension header filtering */ 1381 /* end of ipv6 variables */ 1382 1383 int is_ipv4 = 0; 1384 1385 int done = 0; /* flag to exit the outer loop */ 1386 1387 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready)) 1388 return (IP_FW_PASS); /* accept */ 1389 1390 dst_ip.s_addr = 0; /* make sure it is initialized */ 1391 src_ip.s_addr = 0; /* make sure it is initialized */ 1392 pktlen = m->m_pkthdr.len; 1393 args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */ 1394 proto = args->f_id.proto = 0; /* mark f_id invalid */ 1395 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ 1396 1397 /* 1398 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 1399 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 1400 * pointer might become stale after other pullups (but we never use it 1401 * this way). 1402 */ 1403 #define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T)) 1404 #define PULLUP_LEN(_len, p, T) \ 1405 do { \ 1406 int x = (_len) + T; \ 1407 if ((m)->m_len < x) { \ 1408 args->m = m = m_pullup(m, x); \ 1409 if (m == NULL) \ 1410 goto pullup_failed; \ 1411 } \ 1412 p = (mtod(m, char *) + (_len)); \ 1413 } while (0) 1414 1415 /* 1416 * if we have an ether header, 1417 */ 1418 if (args->eh) 1419 etype = ntohs(args->eh->ether_type); 1420 1421 /* Identify IP packets and fill up variables. */ 1422 if (pktlen >= sizeof(struct ip6_hdr) && 1423 (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) { 1424 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 1425 is_ipv6 = 1; 1426 args->f_id.addr_type = 6; 1427 hlen = sizeof(struct ip6_hdr); 1428 proto = ip6->ip6_nxt; 1429 1430 /* Search extension headers to find upper layer protocols */ 1431 while (ulp == NULL && offset == 0) { 1432 switch (proto) { 1433 case IPPROTO_ICMPV6: 1434 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 1435 icmp6_type = ICMP6(ulp)->icmp6_type; 1436 break; 1437 1438 case IPPROTO_TCP: 1439 PULLUP_TO(hlen, ulp, struct tcphdr); 1440 dst_port = TCP(ulp)->th_dport; 1441 src_port = TCP(ulp)->th_sport; 1442 /* save flags for dynamic rules */ 1443 args->f_id._flags = TCP(ulp)->th_flags; 1444 break; 1445 1446 case IPPROTO_SCTP: 1447 if (pktlen >= hlen + sizeof(struct sctphdr) + 1448 sizeof(struct sctp_chunkhdr) + 1449 offsetof(struct sctp_init, a_rwnd)) 1450 PULLUP_LEN(hlen, ulp, 1451 sizeof(struct sctphdr) + 1452 sizeof(struct sctp_chunkhdr) + 1453 offsetof(struct sctp_init, a_rwnd)); 1454 else if (pktlen >= hlen + sizeof(struct sctphdr)) 1455 PULLUP_LEN(hlen, ulp, pktlen - hlen); 1456 else 1457 PULLUP_LEN(hlen, ulp, 1458 sizeof(struct sctphdr)); 1459 src_port = SCTP(ulp)->src_port; 1460 dst_port = SCTP(ulp)->dest_port; 1461 break; 1462 1463 case IPPROTO_UDP: 1464 case IPPROTO_UDPLITE: 1465 PULLUP_TO(hlen, ulp, struct udphdr); 1466 dst_port = UDP(ulp)->uh_dport; 1467 src_port = UDP(ulp)->uh_sport; 1468 break; 1469 1470 case IPPROTO_HOPOPTS: /* RFC 2460 */ 1471 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1472 ext_hd |= EXT_HOPOPTS; 1473 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1474 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1475 ulp = NULL; 1476 break; 1477 1478 case IPPROTO_ROUTING: /* RFC 2460 */ 1479 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 1480 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 1481 case 0: 1482 ext_hd |= EXT_RTHDR0; 1483 break; 1484 case 2: 1485 ext_hd |= EXT_RTHDR2; 1486 break; 1487 default: 1488 if (V_fw_verbose) 1489 printf("IPFW2: IPV6 - Unknown " 1490 "Routing Header type(%d)\n", 1491 ((struct ip6_rthdr *) 1492 ulp)->ip6r_type); 1493 if (V_fw_deny_unknown_exthdrs) 1494 return (IP_FW_DENY); 1495 break; 1496 } 1497 ext_hd |= EXT_ROUTING; 1498 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 1499 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 1500 ulp = NULL; 1501 break; 1502 1503 case IPPROTO_FRAGMENT: /* RFC 2460 */ 1504 PULLUP_TO(hlen, ulp, struct ip6_frag); 1505 ext_hd |= EXT_FRAGMENT; 1506 hlen += sizeof (struct ip6_frag); 1507 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 1508 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 1509 IP6F_OFF_MASK; 1510 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg & 1511 IP6F_MORE_FRAG; 1512 if (V_fw_permit_single_frag6 == 0 && 1513 offset == 0 && ip6f_mf == 0) { 1514 if (V_fw_verbose) 1515 printf("IPFW2: IPV6 - Invalid " 1516 "Fragment Header\n"); 1517 if (V_fw_deny_unknown_exthdrs) 1518 return (IP_FW_DENY); 1519 break; 1520 } 1521 args->f_id.extra = 1522 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 1523 ulp = NULL; 1524 break; 1525 1526 case IPPROTO_DSTOPTS: /* RFC 2460 */ 1527 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1528 ext_hd |= EXT_DSTOPTS; 1529 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1530 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1531 ulp = NULL; 1532 break; 1533 1534 case IPPROTO_AH: /* RFC 2402 */ 1535 PULLUP_TO(hlen, ulp, struct ip6_ext); 1536 ext_hd |= EXT_AH; 1537 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 1538 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 1539 ulp = NULL; 1540 break; 1541 1542 case IPPROTO_ESP: /* RFC 2406 */ 1543 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 1544 /* Anything past Seq# is variable length and 1545 * data past this ext. header is encrypted. */ 1546 ext_hd |= EXT_ESP; 1547 break; 1548 1549 case IPPROTO_NONE: /* RFC 2460 */ 1550 /* 1551 * Packet ends here, and IPv6 header has 1552 * already been pulled up. If ip6e_len!=0 1553 * then octets must be ignored. 1554 */ 1555 ulp = ip; /* non-NULL to get out of loop. */ 1556 break; 1557 1558 case IPPROTO_OSPFIGP: 1559 /* XXX OSPF header check? */ 1560 PULLUP_TO(hlen, ulp, struct ip6_ext); 1561 break; 1562 1563 case IPPROTO_PIM: 1564 /* XXX PIM header check? */ 1565 PULLUP_TO(hlen, ulp, struct pim); 1566 break; 1567 1568 case IPPROTO_GRE: /* RFC 1701 */ 1569 /* XXX GRE header check? */ 1570 PULLUP_TO(hlen, ulp, struct grehdr); 1571 break; 1572 1573 case IPPROTO_CARP: 1574 PULLUP_TO(hlen, ulp, struct carp_header); 1575 if (((struct carp_header *)ulp)->carp_version != 1576 CARP_VERSION) 1577 return (IP_FW_DENY); 1578 if (((struct carp_header *)ulp)->carp_type != 1579 CARP_ADVERTISEMENT) 1580 return (IP_FW_DENY); 1581 break; 1582 1583 case IPPROTO_IPV6: /* RFC 2893 */ 1584 PULLUP_TO(hlen, ulp, struct ip6_hdr); 1585 break; 1586 1587 case IPPROTO_IPV4: /* RFC 2893 */ 1588 PULLUP_TO(hlen, ulp, struct ip); 1589 break; 1590 1591 default: 1592 if (V_fw_verbose) 1593 printf("IPFW2: IPV6 - Unknown " 1594 "Extension Header(%d), ext_hd=%x\n", 1595 proto, ext_hd); 1596 if (V_fw_deny_unknown_exthdrs) 1597 return (IP_FW_DENY); 1598 PULLUP_TO(hlen, ulp, struct ip6_ext); 1599 break; 1600 } /*switch */ 1601 } 1602 ip = mtod(m, struct ip *); 1603 ip6 = (struct ip6_hdr *)ip; 1604 args->f_id.src_ip6 = ip6->ip6_src; 1605 args->f_id.dst_ip6 = ip6->ip6_dst; 1606 args->f_id.src_ip = 0; 1607 args->f_id.dst_ip = 0; 1608 args->f_id.flow_id6 = ntohl(ip6->ip6_flow); 1609 iplen = ntohs(ip6->ip6_plen) + sizeof(*ip6); 1610 } else if (pktlen >= sizeof(struct ip) && 1611 (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) { 1612 is_ipv4 = 1; 1613 hlen = ip->ip_hl << 2; 1614 args->f_id.addr_type = 4; 1615 1616 /* 1617 * Collect parameters into local variables for faster matching. 1618 */ 1619 proto = ip->ip_p; 1620 src_ip = ip->ip_src; 1621 dst_ip = ip->ip_dst; 1622 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1623 iplen = ntohs(ip->ip_len); 1624 1625 if (offset == 0) { 1626 switch (proto) { 1627 case IPPROTO_TCP: 1628 PULLUP_TO(hlen, ulp, struct tcphdr); 1629 dst_port = TCP(ulp)->th_dport; 1630 src_port = TCP(ulp)->th_sport; 1631 /* save flags for dynamic rules */ 1632 args->f_id._flags = TCP(ulp)->th_flags; 1633 break; 1634 1635 case IPPROTO_SCTP: 1636 if (pktlen >= hlen + sizeof(struct sctphdr) + 1637 sizeof(struct sctp_chunkhdr) + 1638 offsetof(struct sctp_init, a_rwnd)) 1639 PULLUP_LEN(hlen, ulp, 1640 sizeof(struct sctphdr) + 1641 sizeof(struct sctp_chunkhdr) + 1642 offsetof(struct sctp_init, a_rwnd)); 1643 else if (pktlen >= hlen + sizeof(struct sctphdr)) 1644 PULLUP_LEN(hlen, ulp, pktlen - hlen); 1645 else 1646 PULLUP_LEN(hlen, ulp, 1647 sizeof(struct sctphdr)); 1648 src_port = SCTP(ulp)->src_port; 1649 dst_port = SCTP(ulp)->dest_port; 1650 break; 1651 1652 case IPPROTO_UDP: 1653 case IPPROTO_UDPLITE: 1654 PULLUP_TO(hlen, ulp, struct udphdr); 1655 dst_port = UDP(ulp)->uh_dport; 1656 src_port = UDP(ulp)->uh_sport; 1657 break; 1658 1659 case IPPROTO_ICMP: 1660 PULLUP_TO(hlen, ulp, struct icmphdr); 1661 //args->f_id.flags = ICMP(ulp)->icmp_type; 1662 break; 1663 1664 default: 1665 break; 1666 } 1667 } 1668 1669 ip = mtod(m, struct ip *); 1670 args->f_id.src_ip = ntohl(src_ip.s_addr); 1671 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1672 } 1673 #undef PULLUP_TO 1674 pktlen = iplen < pktlen ? iplen: pktlen; 1675 if (proto) { /* we may have port numbers, store them */ 1676 args->f_id.proto = proto; 1677 args->f_id.src_port = src_port = ntohs(src_port); 1678 args->f_id.dst_port = dst_port = ntohs(dst_port); 1679 } 1680 1681 IPFW_PF_RLOCK(chain); 1682 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ 1683 IPFW_PF_RUNLOCK(chain); 1684 return (IP_FW_PASS); /* accept */ 1685 } 1686 if (args->rule.slot) { 1687 /* 1688 * Packet has already been tagged as a result of a previous 1689 * match on rule args->rule aka args->rule_id (PIPE, QUEUE, 1690 * REASS, NETGRAPH, DIVERT/TEE...) 1691 * Validate the slot and continue from the next one 1692 * if still present, otherwise do a lookup. 1693 */ 1694 f_pos = (args->rule.chain_id == chain->id) ? 1695 args->rule.slot : 1696 ipfw_find_rule(chain, args->rule.rulenum, 1697 args->rule.rule_id); 1698 } else { 1699 f_pos = 0; 1700 } 1701 1702 /* 1703 * Now scan the rules, and parse microinstructions for each rule. 1704 * We have two nested loops and an inner switch. Sometimes we 1705 * need to break out of one or both loops, or re-enter one of 1706 * the loops with updated variables. Loop variables are: 1707 * 1708 * f_pos (outer loop) points to the current rule. 1709 * On output it points to the matching rule. 1710 * done (outer loop) is used as a flag to break the loop. 1711 * l (inner loop) residual length of current rule. 1712 * cmd points to the current microinstruction. 1713 * 1714 * We break the inner loop by setting l=0 and possibly 1715 * cmdlen=0 if we don't want to advance cmd. 1716 * We break the outer loop by setting done=1 1717 * We can restart the inner loop by setting l>0 and f_pos, f, cmd 1718 * as needed. 1719 */ 1720 for (; f_pos < chain->n_rules; f_pos++) { 1721 ipfw_insn *cmd; 1722 uint32_t tablearg = 0; 1723 int l, cmdlen, skip_or; /* skip rest of OR block */ 1724 struct ip_fw *f; 1725 1726 f = chain->map[f_pos]; 1727 if (V_set_disable & (1 << f->set) ) 1728 continue; 1729 1730 skip_or = 0; 1731 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 1732 l -= cmdlen, cmd += cmdlen) { 1733 int match; 1734 1735 /* 1736 * check_body is a jump target used when we find a 1737 * CHECK_STATE, and need to jump to the body of 1738 * the target rule. 1739 */ 1740 1741 /* check_body: */ 1742 cmdlen = F_LEN(cmd); 1743 /* 1744 * An OR block (insn_1 || .. || insn_n) has the 1745 * F_OR bit set in all but the last instruction. 1746 * The first match will set "skip_or", and cause 1747 * the following instructions to be skipped until 1748 * past the one with the F_OR bit clear. 1749 */ 1750 if (skip_or) { /* skip this instruction */ 1751 if ((cmd->len & F_OR) == 0) 1752 skip_or = 0; /* next one is good */ 1753 continue; 1754 } 1755 match = 0; /* set to 1 if we succeed */ 1756 1757 switch (cmd->opcode) { 1758 /* 1759 * The first set of opcodes compares the packet's 1760 * fields with some pattern, setting 'match' if a 1761 * match is found. At the end of the loop there is 1762 * logic to deal with F_NOT and F_OR flags associated 1763 * with the opcode. 1764 */ 1765 case O_NOP: 1766 match = 1; 1767 break; 1768 1769 case O_FORWARD_MAC: 1770 printf("ipfw: opcode %d unimplemented\n", 1771 cmd->opcode); 1772 break; 1773 1774 case O_GID: 1775 case O_UID: 1776 case O_JAIL: 1777 /* 1778 * We only check offset == 0 && proto != 0, 1779 * as this ensures that we have a 1780 * packet with the ports info. 1781 */ 1782 if (offset != 0) 1783 break; 1784 if (proto == IPPROTO_TCP || 1785 proto == IPPROTO_UDP || 1786 proto == IPPROTO_UDPLITE) 1787 match = check_uidgid( 1788 (ipfw_insn_u32 *)cmd, 1789 args, &ucred_lookup, 1790 #ifdef __FreeBSD__ 1791 &ucred_cache); 1792 #else 1793 (void *)&ucred_cache); 1794 #endif 1795 break; 1796 1797 case O_RECV: 1798 match = iface_match(m->m_pkthdr.rcvif, 1799 (ipfw_insn_if *)cmd, chain, &tablearg); 1800 break; 1801 1802 case O_XMIT: 1803 match = iface_match(oif, (ipfw_insn_if *)cmd, 1804 chain, &tablearg); 1805 break; 1806 1807 case O_VIA: 1808 match = iface_match(oif ? oif : 1809 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd, 1810 chain, &tablearg); 1811 break; 1812 1813 case O_MACADDR2: 1814 if (args->eh != NULL) { /* have MAC header */ 1815 u_int32_t *want = (u_int32_t *) 1816 ((ipfw_insn_mac *)cmd)->addr; 1817 u_int32_t *mask = (u_int32_t *) 1818 ((ipfw_insn_mac *)cmd)->mask; 1819 u_int32_t *hdr = (u_int32_t *)args->eh; 1820 1821 match = 1822 ( want[0] == (hdr[0] & mask[0]) && 1823 want[1] == (hdr[1] & mask[1]) && 1824 want[2] == (hdr[2] & mask[2]) ); 1825 } 1826 break; 1827 1828 case O_MAC_TYPE: 1829 if (args->eh != NULL) { 1830 u_int16_t *p = 1831 ((ipfw_insn_u16 *)cmd)->ports; 1832 int i; 1833 1834 for (i = cmdlen - 1; !match && i>0; 1835 i--, p += 2) 1836 match = (etype >= p[0] && 1837 etype <= p[1]); 1838 } 1839 break; 1840 1841 case O_FRAG: 1842 match = (offset != 0); 1843 break; 1844 1845 case O_IN: /* "out" is "not in" */ 1846 match = (oif == NULL); 1847 break; 1848 1849 case O_LAYER2: 1850 match = (args->eh != NULL); 1851 break; 1852 1853 case O_DIVERTED: 1854 { 1855 /* For diverted packets, args->rule.info 1856 * contains the divert port (in host format) 1857 * reason and direction. 1858 */ 1859 uint32_t i = args->rule.info; 1860 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT && 1861 cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2); 1862 } 1863 break; 1864 1865 case O_PROTO: 1866 /* 1867 * We do not allow an arg of 0 so the 1868 * check of "proto" only suffices. 1869 */ 1870 match = (proto == cmd->arg1); 1871 break; 1872 1873 case O_IP_SRC: 1874 match = is_ipv4 && 1875 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1876 src_ip.s_addr); 1877 break; 1878 1879 case O_IP_DST_LOOKUP: 1880 { 1881 void *pkey; 1882 uint32_t vidx, key; 1883 uint16_t keylen; 1884 1885 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { 1886 /* Determine lookup key type */ 1887 vidx = ((ipfw_insn_u32 *)cmd)->d[1]; 1888 if (vidx != 4 /* uid */ && 1889 vidx != 5 /* jail */ && 1890 is_ipv6 == 0 && is_ipv4 == 0) 1891 break; 1892 /* Determine key length */ 1893 if (vidx == 0 /* dst-ip */ || 1894 vidx == 1 /* src-ip */) 1895 keylen = is_ipv6 ? 1896 sizeof(struct in6_addr): 1897 sizeof(in_addr_t); 1898 else { 1899 keylen = sizeof(key); 1900 pkey = &key; 1901 } 1902 if (vidx == 0 /* dst-ip */) 1903 pkey = is_ipv4 ? (void *)&dst_ip: 1904 (void *)&args->f_id.dst_ip6; 1905 else if (vidx == 1 /* src-ip */) 1906 pkey = is_ipv4 ? (void *)&src_ip: 1907 (void *)&args->f_id.src_ip6; 1908 else if (vidx == 6 /* dscp */) { 1909 if (is_ipv4) 1910 key = ip->ip_tos >> 2; 1911 else { 1912 key = args->f_id.flow_id6; 1913 key = (key & 0x0f) << 2 | 1914 (key & 0xf000) >> 14; 1915 } 1916 key &= 0x3f; 1917 } else if (vidx == 2 /* dst-port */ || 1918 vidx == 3 /* src-port */) { 1919 /* Skip fragments */ 1920 if (offset != 0) 1921 break; 1922 /* Skip proto without ports */ 1923 if (proto != IPPROTO_TCP && 1924 proto != IPPROTO_UDP && 1925 proto != IPPROTO_UDPLITE && 1926 proto != IPPROTO_SCTP) 1927 break; 1928 if (vidx == 2 /* dst-port */) 1929 key = dst_port; 1930 else 1931 key = src_port; 1932 } 1933 #ifndef USERSPACE 1934 else if (vidx == 4 /* uid */ || 1935 vidx == 5 /* jail */) { 1936 check_uidgid( 1937 (ipfw_insn_u32 *)cmd, 1938 args, &ucred_lookup, 1939 #ifdef __FreeBSD__ 1940 &ucred_cache); 1941 if (vidx == 4 /* uid */) 1942 key = ucred_cache->cr_uid; 1943 else if (vidx == 5 /* jail */) 1944 key = ucred_cache->cr_prison->pr_id; 1945 #else /* !__FreeBSD__ */ 1946 (void *)&ucred_cache); 1947 if (vidx == 4 /* uid */) 1948 key = ucred_cache.uid; 1949 else if (vidx == 5 /* jail */) 1950 key = ucred_cache.xid; 1951 #endif /* !__FreeBSD__ */ 1952 } 1953 #endif /* !USERSPACE */ 1954 else 1955 break; 1956 match = ipfw_lookup_table(chain, 1957 cmd->arg1, keylen, pkey, &vidx); 1958 if (!match) 1959 break; 1960 tablearg = vidx; 1961 break; 1962 } 1963 /* cmdlen =< F_INSN_SIZE(ipfw_insn_u32) */ 1964 /* FALLTHROUGH */ 1965 } 1966 case O_IP_SRC_LOOKUP: 1967 { 1968 void *pkey; 1969 uint32_t vidx; 1970 uint16_t keylen; 1971 1972 if (is_ipv4) { 1973 keylen = sizeof(in_addr_t); 1974 if (cmd->opcode == O_IP_DST_LOOKUP) 1975 pkey = &dst_ip; 1976 else 1977 pkey = &src_ip; 1978 } else if (is_ipv6) { 1979 keylen = sizeof(struct in6_addr); 1980 if (cmd->opcode == O_IP_DST_LOOKUP) 1981 pkey = &args->f_id.dst_ip6; 1982 else 1983 pkey = &args->f_id.src_ip6; 1984 } else 1985 break; 1986 match = ipfw_lookup_table(chain, cmd->arg1, 1987 keylen, pkey, &vidx); 1988 if (!match) 1989 break; 1990 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) { 1991 match = ((ipfw_insn_u32 *)cmd)->d[0] == 1992 TARG_VAL(chain, vidx, tag); 1993 if (!match) 1994 break; 1995 } 1996 tablearg = vidx; 1997 break; 1998 } 1999 2000 case O_IP_FLOW_LOOKUP: 2001 { 2002 uint32_t v = 0; 2003 match = ipfw_lookup_table(chain, 2004 cmd->arg1, 0, &args->f_id, &v); 2005 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 2006 match = ((ipfw_insn_u32 *)cmd)->d[0] == 2007 TARG_VAL(chain, v, tag); 2008 if (match) 2009 tablearg = v; 2010 } 2011 break; 2012 case O_IP_SRC_MASK: 2013 case O_IP_DST_MASK: 2014 if (is_ipv4) { 2015 uint32_t a = 2016 (cmd->opcode == O_IP_DST_MASK) ? 2017 dst_ip.s_addr : src_ip.s_addr; 2018 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 2019 int i = cmdlen-1; 2020 2021 for (; !match && i>0; i-= 2, p+= 2) 2022 match = (p[0] == (a & p[1])); 2023 } 2024 break; 2025 2026 case O_IP_SRC_ME: 2027 if (is_ipv4) { 2028 match = in_localip(src_ip); 2029 break; 2030 } 2031 #ifdef INET6 2032 /* FALLTHROUGH */ 2033 case O_IP6_SRC_ME: 2034 match= is_ipv6 && ipfw_localip6(&args->f_id.src_ip6); 2035 #endif 2036 break; 2037 2038 case O_IP_DST_SET: 2039 case O_IP_SRC_SET: 2040 if (is_ipv4) { 2041 u_int32_t *d = (u_int32_t *)(cmd+1); 2042 u_int32_t addr = 2043 cmd->opcode == O_IP_DST_SET ? 2044 args->f_id.dst_ip : 2045 args->f_id.src_ip; 2046 2047 if (addr < d[0]) 2048 break; 2049 addr -= d[0]; /* subtract base */ 2050 match = (addr < cmd->arg1) && 2051 ( d[ 1 + (addr>>5)] & 2052 (1<<(addr & 0x1f)) ); 2053 } 2054 break; 2055 2056 case O_IP_DST: 2057 match = is_ipv4 && 2058 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2059 dst_ip.s_addr); 2060 break; 2061 2062 case O_IP_DST_ME: 2063 if (is_ipv4) { 2064 match = in_localip(dst_ip); 2065 break; 2066 } 2067 #ifdef INET6 2068 /* FALLTHROUGH */ 2069 case O_IP6_DST_ME: 2070 match= is_ipv6 && ipfw_localip6(&args->f_id.dst_ip6); 2071 #endif 2072 break; 2073 2074 2075 case O_IP_SRCPORT: 2076 case O_IP_DSTPORT: 2077 /* 2078 * offset == 0 && proto != 0 is enough 2079 * to guarantee that we have a 2080 * packet with port info. 2081 */ 2082 if ((proto == IPPROTO_UDP || 2083 proto == IPPROTO_UDPLITE || 2084 proto == IPPROTO_TCP || 2085 proto == IPPROTO_SCTP) && offset == 0) { 2086 u_int16_t x = 2087 (cmd->opcode == O_IP_SRCPORT) ? 2088 src_port : dst_port ; 2089 u_int16_t *p = 2090 ((ipfw_insn_u16 *)cmd)->ports; 2091 int i; 2092 2093 for (i = cmdlen - 1; !match && i>0; 2094 i--, p += 2) 2095 match = (x>=p[0] && x<=p[1]); 2096 } 2097 break; 2098 2099 case O_ICMPTYPE: 2100 match = (offset == 0 && proto==IPPROTO_ICMP && 2101 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 2102 break; 2103 2104 #ifdef INET6 2105 case O_ICMP6TYPE: 2106 match = is_ipv6 && offset == 0 && 2107 proto==IPPROTO_ICMPV6 && 2108 icmp6type_match( 2109 ICMP6(ulp)->icmp6_type, 2110 (ipfw_insn_u32 *)cmd); 2111 break; 2112 #endif /* INET6 */ 2113 2114 case O_IPOPT: 2115 match = (is_ipv4 && 2116 ipopts_match(ip, cmd) ); 2117 break; 2118 2119 case O_IPVER: 2120 match = (is_ipv4 && 2121 cmd->arg1 == ip->ip_v); 2122 break; 2123 2124 case O_IPID: 2125 case O_IPLEN: 2126 case O_IPTTL: 2127 if (is_ipv4) { /* only for IP packets */ 2128 uint16_t x; 2129 uint16_t *p; 2130 int i; 2131 2132 if (cmd->opcode == O_IPLEN) 2133 x = iplen; 2134 else if (cmd->opcode == O_IPTTL) 2135 x = ip->ip_ttl; 2136 else /* must be IPID */ 2137 x = ntohs(ip->ip_id); 2138 if (cmdlen == 1) { 2139 match = (cmd->arg1 == x); 2140 break; 2141 } 2142 /* otherwise we have ranges */ 2143 p = ((ipfw_insn_u16 *)cmd)->ports; 2144 i = cmdlen - 1; 2145 for (; !match && i>0; i--, p += 2) 2146 match = (x >= p[0] && x <= p[1]); 2147 } 2148 break; 2149 2150 case O_IPPRECEDENCE: 2151 match = (is_ipv4 && 2152 (cmd->arg1 == (ip->ip_tos & 0xe0)) ); 2153 break; 2154 2155 case O_IPTOS: 2156 match = (is_ipv4 && 2157 flags_match(cmd, ip->ip_tos)); 2158 break; 2159 2160 case O_DSCP: 2161 { 2162 uint32_t *p; 2163 uint16_t x; 2164 2165 p = ((ipfw_insn_u32 *)cmd)->d; 2166 2167 if (is_ipv4) 2168 x = ip->ip_tos >> 2; 2169 else if (is_ipv6) { 2170 uint8_t *v; 2171 v = &((struct ip6_hdr *)ip)->ip6_vfc; 2172 x = (*v & 0x0F) << 2; 2173 v++; 2174 x |= *v >> 6; 2175 } else 2176 break; 2177 2178 /* DSCP bitmask is stored as low_u32 high_u32 */ 2179 if (x >= 32) 2180 match = *(p + 1) & (1 << (x - 32)); 2181 else 2182 match = *p & (1 << x); 2183 } 2184 break; 2185 2186 case O_TCPDATALEN: 2187 if (proto == IPPROTO_TCP && offset == 0) { 2188 struct tcphdr *tcp; 2189 uint16_t x; 2190 uint16_t *p; 2191 int i; 2192 #ifdef INET6 2193 if (is_ipv6) { 2194 struct ip6_hdr *ip6; 2195 2196 ip6 = (struct ip6_hdr *)ip; 2197 if (ip6->ip6_plen == 0) { 2198 /* 2199 * Jumbo payload is not 2200 * supported by this 2201 * opcode. 2202 */ 2203 break; 2204 } 2205 x = iplen - hlen; 2206 } else 2207 #endif /* INET6 */ 2208 x = iplen - (ip->ip_hl << 2); 2209 tcp = TCP(ulp); 2210 x -= tcp->th_off << 2; 2211 if (cmdlen == 1) { 2212 match = (cmd->arg1 == x); 2213 break; 2214 } 2215 /* otherwise we have ranges */ 2216 p = ((ipfw_insn_u16 *)cmd)->ports; 2217 i = cmdlen - 1; 2218 for (; !match && i>0; i--, p += 2) 2219 match = (x >= p[0] && x <= p[1]); 2220 } 2221 break; 2222 2223 case O_TCPFLAGS: 2224 match = (proto == IPPROTO_TCP && offset == 0 && 2225 flags_match(cmd, TCP(ulp)->th_flags)); 2226 break; 2227 2228 case O_TCPOPTS: 2229 if (proto == IPPROTO_TCP && offset == 0 && ulp){ 2230 PULLUP_LEN(hlen, ulp, 2231 (TCP(ulp)->th_off << 2)); 2232 match = tcpopts_match(TCP(ulp), cmd); 2233 } 2234 break; 2235 2236 case O_TCPSEQ: 2237 match = (proto == IPPROTO_TCP && offset == 0 && 2238 ((ipfw_insn_u32 *)cmd)->d[0] == 2239 TCP(ulp)->th_seq); 2240 break; 2241 2242 case O_TCPACK: 2243 match = (proto == IPPROTO_TCP && offset == 0 && 2244 ((ipfw_insn_u32 *)cmd)->d[0] == 2245 TCP(ulp)->th_ack); 2246 break; 2247 2248 case O_TCPWIN: 2249 if (proto == IPPROTO_TCP && offset == 0) { 2250 uint16_t x; 2251 uint16_t *p; 2252 int i; 2253 2254 x = ntohs(TCP(ulp)->th_win); 2255 if (cmdlen == 1) { 2256 match = (cmd->arg1 == x); 2257 break; 2258 } 2259 /* Otherwise we have ranges. */ 2260 p = ((ipfw_insn_u16 *)cmd)->ports; 2261 i = cmdlen - 1; 2262 for (; !match && i > 0; i--, p += 2) 2263 match = (x >= p[0] && x <= p[1]); 2264 } 2265 break; 2266 2267 case O_ESTAB: 2268 /* reject packets which have SYN only */ 2269 /* XXX should i also check for TH_ACK ? */ 2270 match = (proto == IPPROTO_TCP && offset == 0 && 2271 (TCP(ulp)->th_flags & 2272 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 2273 break; 2274 2275 case O_ALTQ: { 2276 struct pf_mtag *at; 2277 struct m_tag *mtag; 2278 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 2279 2280 /* 2281 * ALTQ uses mbuf tags from another 2282 * packet filtering system - pf(4). 2283 * We allocate a tag in its format 2284 * and fill it in, pretending to be pf(4). 2285 */ 2286 match = 1; 2287 at = pf_find_mtag(m); 2288 if (at != NULL && at->qid != 0) 2289 break; 2290 mtag = m_tag_get(PACKET_TAG_PF, 2291 sizeof(struct pf_mtag), M_NOWAIT | M_ZERO); 2292 if (mtag == NULL) { 2293 /* 2294 * Let the packet fall back to the 2295 * default ALTQ. 2296 */ 2297 break; 2298 } 2299 m_tag_prepend(m, mtag); 2300 at = (struct pf_mtag *)(mtag + 1); 2301 at->qid = altq->qid; 2302 at->hdr = ip; 2303 break; 2304 } 2305 2306 case O_LOG: 2307 ipfw_log(chain, f, hlen, args, m, 2308 oif, offset | ip6f_mf, tablearg, ip); 2309 match = 1; 2310 break; 2311 2312 case O_PROB: 2313 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 2314 break; 2315 2316 case O_VERREVPATH: 2317 /* Outgoing packets automatically pass/match */ 2318 match = ((oif != NULL) || 2319 (m->m_pkthdr.rcvif == NULL) || 2320 ( 2321 #ifdef INET6 2322 is_ipv6 ? 2323 verify_path6(&(args->f_id.src_ip6), 2324 m->m_pkthdr.rcvif, args->f_id.fib) : 2325 #endif 2326 verify_path(src_ip, m->m_pkthdr.rcvif, 2327 args->f_id.fib))); 2328 break; 2329 2330 case O_VERSRCREACH: 2331 /* Outgoing packets automatically pass/match */ 2332 match = (hlen > 0 && ((oif != NULL) || 2333 #ifdef INET6 2334 is_ipv6 ? 2335 verify_path6(&(args->f_id.src_ip6), 2336 NULL, args->f_id.fib) : 2337 #endif 2338 verify_path(src_ip, NULL, args->f_id.fib))); 2339 break; 2340 2341 case O_ANTISPOOF: 2342 /* Outgoing packets automatically pass/match */ 2343 if (oif == NULL && hlen > 0 && 2344 ( (is_ipv4 && in_localaddr(src_ip)) 2345 #ifdef INET6 2346 || (is_ipv6 && 2347 in6_localaddr(&(args->f_id.src_ip6))) 2348 #endif 2349 )) 2350 match = 2351 #ifdef INET6 2352 is_ipv6 ? verify_path6( 2353 &(args->f_id.src_ip6), 2354 m->m_pkthdr.rcvif, 2355 args->f_id.fib) : 2356 #endif 2357 verify_path(src_ip, 2358 m->m_pkthdr.rcvif, 2359 args->f_id.fib); 2360 else 2361 match = 1; 2362 break; 2363 2364 case O_IPSEC: 2365 match = (m_tag_find(m, 2366 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 2367 /* otherwise no match */ 2368 break; 2369 2370 #ifdef INET6 2371 case O_IP6_SRC: 2372 match = is_ipv6 && 2373 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 2374 &((ipfw_insn_ip6 *)cmd)->addr6); 2375 break; 2376 2377 case O_IP6_DST: 2378 match = is_ipv6 && 2379 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 2380 &((ipfw_insn_ip6 *)cmd)->addr6); 2381 break; 2382 case O_IP6_SRC_MASK: 2383 case O_IP6_DST_MASK: 2384 if (is_ipv6) { 2385 int i = cmdlen - 1; 2386 struct in6_addr p; 2387 struct in6_addr *d = 2388 &((ipfw_insn_ip6 *)cmd)->addr6; 2389 2390 for (; !match && i > 0; d += 2, 2391 i -= F_INSN_SIZE(struct in6_addr) 2392 * 2) { 2393 p = (cmd->opcode == 2394 O_IP6_SRC_MASK) ? 2395 args->f_id.src_ip6: 2396 args->f_id.dst_ip6; 2397 APPLY_MASK(&p, &d[1]); 2398 match = 2399 IN6_ARE_ADDR_EQUAL(&d[0], 2400 &p); 2401 } 2402 } 2403 break; 2404 2405 case O_FLOW6ID: 2406 match = is_ipv6 && 2407 flow6id_match(args->f_id.flow_id6, 2408 (ipfw_insn_u32 *) cmd); 2409 break; 2410 2411 case O_EXT_HDR: 2412 match = is_ipv6 && 2413 (ext_hd & ((ipfw_insn *) cmd)->arg1); 2414 break; 2415 2416 case O_IP6: 2417 match = is_ipv6; 2418 break; 2419 #endif 2420 2421 case O_IP4: 2422 match = is_ipv4; 2423 break; 2424 2425 case O_TAG: { 2426 struct m_tag *mtag; 2427 uint32_t tag = TARG(cmd->arg1, tag); 2428 2429 /* Packet is already tagged with this tag? */ 2430 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 2431 2432 /* We have `untag' action when F_NOT flag is 2433 * present. And we must remove this mtag from 2434 * mbuf and reset `match' to zero (`match' will 2435 * be inversed later). 2436 * Otherwise we should allocate new mtag and 2437 * push it into mbuf. 2438 */ 2439 if (cmd->len & F_NOT) { /* `untag' action */ 2440 if (mtag != NULL) 2441 m_tag_delete(m, mtag); 2442 match = 0; 2443 } else { 2444 if (mtag == NULL) { 2445 mtag = m_tag_alloc( MTAG_IPFW, 2446 tag, 0, M_NOWAIT); 2447 if (mtag != NULL) 2448 m_tag_prepend(m, mtag); 2449 } 2450 match = 1; 2451 } 2452 break; 2453 } 2454 2455 case O_FIB: /* try match the specified fib */ 2456 if (args->f_id.fib == cmd->arg1) 2457 match = 1; 2458 break; 2459 2460 case O_SOCKARG: { 2461 #ifndef USERSPACE /* not supported in userspace */ 2462 struct inpcb *inp = args->inp; 2463 struct inpcbinfo *pi; 2464 2465 if (is_ipv6) /* XXX can we remove this ? */ 2466 break; 2467 2468 if (proto == IPPROTO_TCP) 2469 pi = &V_tcbinfo; 2470 else if (proto == IPPROTO_UDP) 2471 pi = &V_udbinfo; 2472 else if (proto == IPPROTO_UDPLITE) 2473 pi = &V_ulitecbinfo; 2474 else 2475 break; 2476 2477 /* 2478 * XXXRW: so_user_cookie should almost 2479 * certainly be inp_user_cookie? 2480 */ 2481 2482 /* For incoming packet, lookup up the 2483 inpcb using the src/dest ip/port tuple */ 2484 if (inp == NULL) { 2485 inp = in_pcblookup(pi, 2486 src_ip, htons(src_port), 2487 dst_ip, htons(dst_port), 2488 INPLOOKUP_RLOCKPCB, NULL); 2489 if (inp != NULL) { 2490 tablearg = 2491 inp->inp_socket->so_user_cookie; 2492 if (tablearg) 2493 match = 1; 2494 INP_RUNLOCK(inp); 2495 } 2496 } else { 2497 if (inp->inp_socket) { 2498 tablearg = 2499 inp->inp_socket->so_user_cookie; 2500 if (tablearg) 2501 match = 1; 2502 } 2503 } 2504 #endif /* !USERSPACE */ 2505 break; 2506 } 2507 2508 case O_TAGGED: { 2509 struct m_tag *mtag; 2510 uint32_t tag = TARG(cmd->arg1, tag); 2511 2512 if (cmdlen == 1) { 2513 match = m_tag_locate(m, MTAG_IPFW, 2514 tag, NULL) != NULL; 2515 break; 2516 } 2517 2518 /* we have ranges */ 2519 for (mtag = m_tag_first(m); 2520 mtag != NULL && !match; 2521 mtag = m_tag_next(m, mtag)) { 2522 uint16_t *p; 2523 int i; 2524 2525 if (mtag->m_tag_cookie != MTAG_IPFW) 2526 continue; 2527 2528 p = ((ipfw_insn_u16 *)cmd)->ports; 2529 i = cmdlen - 1; 2530 for(; !match && i > 0; i--, p += 2) 2531 match = 2532 mtag->m_tag_id >= p[0] && 2533 mtag->m_tag_id <= p[1]; 2534 } 2535 break; 2536 } 2537 2538 /* 2539 * The second set of opcodes represents 'actions', 2540 * i.e. the terminal part of a rule once the packet 2541 * matches all previous patterns. 2542 * Typically there is only one action for each rule, 2543 * and the opcode is stored at the end of the rule 2544 * (but there are exceptions -- see below). 2545 * 2546 * In general, here we set retval and terminate the 2547 * outer loop (would be a 'break 3' in some language, 2548 * but we need to set l=0, done=1) 2549 * 2550 * Exceptions: 2551 * O_COUNT and O_SKIPTO actions: 2552 * instead of terminating, we jump to the next rule 2553 * (setting l=0), or to the SKIPTO target (setting 2554 * f/f_len, cmd and l as needed), respectively. 2555 * 2556 * O_TAG, O_LOG and O_ALTQ action parameters: 2557 * perform some action and set match = 1; 2558 * 2559 * O_LIMIT and O_KEEP_STATE: these opcodes are 2560 * not real 'actions', and are stored right 2561 * before the 'action' part of the rule. 2562 * These opcodes try to install an entry in the 2563 * state tables; if successful, we continue with 2564 * the next opcode (match=1; break;), otherwise 2565 * the packet must be dropped (set retval, 2566 * break loops with l=0, done=1) 2567 * 2568 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2569 * cause a lookup of the state table, and a jump 2570 * to the 'action' part of the parent rule 2571 * if an entry is found, or 2572 * (CHECK_STATE only) a jump to the next rule if 2573 * the entry is not found. 2574 * The result of the lookup is cached so that 2575 * further instances of these opcodes become NOPs. 2576 * The jump to the next rule is done by setting 2577 * l=0, cmdlen=0. 2578 */ 2579 case O_LIMIT: 2580 case O_KEEP_STATE: 2581 if (ipfw_dyn_install_state(chain, f, 2582 (ipfw_insn_limit *)cmd, args, tablearg)) { 2583 /* error or limit violation */ 2584 retval = IP_FW_DENY; 2585 l = 0; /* exit inner loop */ 2586 done = 1; /* exit outer loop */ 2587 } 2588 match = 1; 2589 break; 2590 2591 case O_PROBE_STATE: 2592 case O_CHECK_STATE: 2593 /* 2594 * dynamic rules are checked at the first 2595 * keep-state or check-state occurrence, 2596 * with the result being stored in dyn_dir 2597 * and dyn_name. 2598 * The compiler introduces a PROBE_STATE 2599 * instruction for us when we have a 2600 * KEEP_STATE (because PROBE_STATE needs 2601 * to be run first). 2602 * 2603 * (dyn_dir == MATCH_UNKNOWN) means this is 2604 * first lookup for such f_id. Do lookup. 2605 * 2606 * (dyn_dir != MATCH_UNKNOWN && 2607 * dyn_name != 0 && dyn_name != cmd->arg1) 2608 * means previous lookup didn't find dynamic 2609 * rule for specific state name and current 2610 * lookup will search rule with another state 2611 * name. Redo lookup. 2612 * 2613 * (dyn_dir != MATCH_UNKNOWN && dyn_name == 0) 2614 * means previous lookup was for `any' name 2615 * and it didn't find rule. No need to do 2616 * lookup again. 2617 */ 2618 if ((dyn_dir == MATCH_UNKNOWN || 2619 (dyn_name != 0 && 2620 dyn_name != cmd->arg1)) && 2621 (q = ipfw_dyn_lookup_state(&args->f_id, 2622 ulp, pktlen, &dyn_dir, 2623 (dyn_name = cmd->arg1))) != NULL) { 2624 /* 2625 * Found dynamic entry, jump to the 2626 * 'action' part of the parent rule 2627 * by setting f, cmd, l and clearing 2628 * cmdlen. 2629 */ 2630 f = q; 2631 /* XXX we would like to have f_pos 2632 * readily accessible in the dynamic 2633 * rule, instead of having to 2634 * lookup q->rule. 2635 */ 2636 f_pos = ipfw_find_rule(chain, 2637 f->rulenum, f->id); 2638 cmd = ACTION_PTR(f); 2639 l = f->cmd_len - f->act_ofs; 2640 cmdlen = 0; 2641 match = 1; 2642 break; 2643 } 2644 /* 2645 * Dynamic entry not found. If CHECK_STATE, 2646 * skip to next rule, if PROBE_STATE just 2647 * ignore and continue with next opcode. 2648 */ 2649 if (cmd->opcode == O_CHECK_STATE) 2650 l = 0; /* exit inner loop */ 2651 match = 1; 2652 break; 2653 2654 case O_ACCEPT: 2655 retval = 0; /* accept */ 2656 l = 0; /* exit inner loop */ 2657 done = 1; /* exit outer loop */ 2658 break; 2659 2660 case O_PIPE: 2661 case O_QUEUE: 2662 set_match(args, f_pos, chain); 2663 args->rule.info = TARG(cmd->arg1, pipe); 2664 if (cmd->opcode == O_PIPE) 2665 args->rule.info |= IPFW_IS_PIPE; 2666 if (V_fw_one_pass) 2667 args->rule.info |= IPFW_ONEPASS; 2668 retval = IP_FW_DUMMYNET; 2669 l = 0; /* exit inner loop */ 2670 done = 1; /* exit outer loop */ 2671 break; 2672 2673 case O_DIVERT: 2674 case O_TEE: 2675 if (args->eh) /* not on layer 2 */ 2676 break; 2677 /* otherwise this is terminal */ 2678 l = 0; /* exit inner loop */ 2679 done = 1; /* exit outer loop */ 2680 retval = (cmd->opcode == O_DIVERT) ? 2681 IP_FW_DIVERT : IP_FW_TEE; 2682 set_match(args, f_pos, chain); 2683 args->rule.info = TARG(cmd->arg1, divert); 2684 break; 2685 2686 case O_COUNT: 2687 IPFW_INC_RULE_COUNTER(f, pktlen); 2688 l = 0; /* exit inner loop */ 2689 break; 2690 2691 case O_SKIPTO: 2692 IPFW_INC_RULE_COUNTER(f, pktlen); 2693 f_pos = JUMP(chain, f, cmd->arg1, tablearg, 0); 2694 /* 2695 * Skip disabled rules, and re-enter 2696 * the inner loop with the correct 2697 * f_pos, f, l and cmd. 2698 * Also clear cmdlen and skip_or 2699 */ 2700 for (; f_pos < chain->n_rules - 1 && 2701 (V_set_disable & 2702 (1 << chain->map[f_pos]->set)); 2703 f_pos++) 2704 ; 2705 /* Re-enter the inner loop at the skipto rule. */ 2706 f = chain->map[f_pos]; 2707 l = f->cmd_len; 2708 cmd = f->cmd; 2709 match = 1; 2710 cmdlen = 0; 2711 skip_or = 0; 2712 continue; 2713 break; /* not reached */ 2714 2715 case O_CALLRETURN: { 2716 /* 2717 * Implementation of `subroutine' call/return, 2718 * in the stack carried in an mbuf tag. This 2719 * is different from `skipto' in that any call 2720 * address is possible (`skipto' must prevent 2721 * backward jumps to avoid endless loops). 2722 * We have `return' action when F_NOT flag is 2723 * present. The `m_tag_id' field is used as 2724 * stack pointer. 2725 */ 2726 struct m_tag *mtag; 2727 uint16_t jmpto, *stack; 2728 2729 #define IS_CALL ((cmd->len & F_NOT) == 0) 2730 #define IS_RETURN ((cmd->len & F_NOT) != 0) 2731 /* 2732 * Hand-rolled version of m_tag_locate() with 2733 * wildcard `type'. 2734 * If not already tagged, allocate new tag. 2735 */ 2736 mtag = m_tag_first(m); 2737 while (mtag != NULL) { 2738 if (mtag->m_tag_cookie == 2739 MTAG_IPFW_CALL) 2740 break; 2741 mtag = m_tag_next(m, mtag); 2742 } 2743 if (mtag == NULL && IS_CALL) { 2744 mtag = m_tag_alloc(MTAG_IPFW_CALL, 0, 2745 IPFW_CALLSTACK_SIZE * 2746 sizeof(uint16_t), M_NOWAIT); 2747 if (mtag != NULL) 2748 m_tag_prepend(m, mtag); 2749 } 2750 2751 /* 2752 * On error both `call' and `return' just 2753 * continue with next rule. 2754 */ 2755 if (IS_RETURN && (mtag == NULL || 2756 mtag->m_tag_id == 0)) { 2757 l = 0; /* exit inner loop */ 2758 break; 2759 } 2760 if (IS_CALL && (mtag == NULL || 2761 mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) { 2762 printf("ipfw: call stack error, " 2763 "go to next rule\n"); 2764 l = 0; /* exit inner loop */ 2765 break; 2766 } 2767 2768 IPFW_INC_RULE_COUNTER(f, pktlen); 2769 stack = (uint16_t *)(mtag + 1); 2770 2771 /* 2772 * The `call' action may use cached f_pos 2773 * (in f->next_rule), whose version is written 2774 * in f->next_rule. 2775 * The `return' action, however, doesn't have 2776 * fixed jump address in cmd->arg1 and can't use 2777 * cache. 2778 */ 2779 if (IS_CALL) { 2780 stack[mtag->m_tag_id] = f->rulenum; 2781 mtag->m_tag_id++; 2782 f_pos = JUMP(chain, f, cmd->arg1, 2783 tablearg, 1); 2784 } else { /* `return' action */ 2785 mtag->m_tag_id--; 2786 jmpto = stack[mtag->m_tag_id] + 1; 2787 f_pos = ipfw_find_rule(chain, jmpto, 0); 2788 } 2789 2790 /* 2791 * Skip disabled rules, and re-enter 2792 * the inner loop with the correct 2793 * f_pos, f, l and cmd. 2794 * Also clear cmdlen and skip_or 2795 */ 2796 for (; f_pos < chain->n_rules - 1 && 2797 (V_set_disable & 2798 (1 << chain->map[f_pos]->set)); f_pos++) 2799 ; 2800 /* Re-enter the inner loop at the dest rule. */ 2801 f = chain->map[f_pos]; 2802 l = f->cmd_len; 2803 cmd = f->cmd; 2804 cmdlen = 0; 2805 skip_or = 0; 2806 continue; 2807 break; /* NOTREACHED */ 2808 } 2809 #undef IS_CALL 2810 #undef IS_RETURN 2811 2812 case O_REJECT: 2813 /* 2814 * Drop the packet and send a reject notice 2815 * if the packet is not ICMP (or is an ICMP 2816 * query), and it is not multicast/broadcast. 2817 */ 2818 if (hlen > 0 && is_ipv4 && offset == 0 && 2819 (proto != IPPROTO_ICMP || 2820 is_icmp_query(ICMP(ulp))) && 2821 !(m->m_flags & (M_BCAST|M_MCAST)) && 2822 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 2823 send_reject(args, cmd->arg1, iplen, ip); 2824 m = args->m; 2825 } 2826 /* FALLTHROUGH */ 2827 #ifdef INET6 2828 case O_UNREACH6: 2829 if (hlen > 0 && is_ipv6 && 2830 ((offset & IP6F_OFF_MASK) == 0) && 2831 (proto != IPPROTO_ICMPV6 || 2832 (is_icmp6_query(icmp6_type) == 1)) && 2833 !(m->m_flags & (M_BCAST|M_MCAST)) && 2834 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 2835 send_reject6( 2836 args, cmd->arg1, hlen, 2837 (struct ip6_hdr *)ip); 2838 m = args->m; 2839 } 2840 /* FALLTHROUGH */ 2841 #endif 2842 case O_DENY: 2843 retval = IP_FW_DENY; 2844 l = 0; /* exit inner loop */ 2845 done = 1; /* exit outer loop */ 2846 break; 2847 2848 case O_FORWARD_IP: 2849 if (args->eh) /* not valid on layer2 pkts */ 2850 break; 2851 if (q != f || dyn_dir == MATCH_FORWARD) { 2852 struct sockaddr_in *sa; 2853 2854 sa = &(((ipfw_insn_sa *)cmd)->sa); 2855 if (sa->sin_addr.s_addr == INADDR_ANY) { 2856 #ifdef INET6 2857 /* 2858 * We use O_FORWARD_IP opcode for 2859 * fwd rule with tablearg, but tables 2860 * now support IPv6 addresses. And 2861 * when we are inspecting IPv6 packet, 2862 * we can use nh6 field from 2863 * table_value as next_hop6 address. 2864 */ 2865 if (is_ipv6) { 2866 struct sockaddr_in6 *sa6; 2867 2868 sa6 = args->next_hop6 = 2869 &args->hopstore6; 2870 sa6->sin6_family = AF_INET6; 2871 sa6->sin6_len = sizeof(*sa6); 2872 sa6->sin6_addr = TARG_VAL( 2873 chain, tablearg, nh6); 2874 sa6->sin6_port = sa->sin_port; 2875 /* 2876 * Set sin6_scope_id only for 2877 * link-local unicast addresses. 2878 */ 2879 if (IN6_IS_ADDR_LINKLOCAL( 2880 &sa6->sin6_addr)) 2881 sa6->sin6_scope_id = 2882 TARG_VAL(chain, 2883 tablearg, 2884 zoneid); 2885 } else 2886 #endif 2887 { 2888 args->hopstore.sin_port = 2889 sa->sin_port; 2890 sa = args->next_hop = 2891 &args->hopstore; 2892 sa->sin_family = AF_INET; 2893 sa->sin_len = sizeof(*sa); 2894 sa->sin_addr.s_addr = htonl( 2895 TARG_VAL(chain, tablearg, 2896 nh4)); 2897 } 2898 } else { 2899 args->next_hop = sa; 2900 } 2901 } 2902 retval = IP_FW_PASS; 2903 l = 0; /* exit inner loop */ 2904 done = 1; /* exit outer loop */ 2905 break; 2906 2907 #ifdef INET6 2908 case O_FORWARD_IP6: 2909 if (args->eh) /* not valid on layer2 pkts */ 2910 break; 2911 if (q != f || dyn_dir == MATCH_FORWARD) { 2912 struct sockaddr_in6 *sin6; 2913 2914 sin6 = &(((ipfw_insn_sa6 *)cmd)->sa); 2915 args->next_hop6 = sin6; 2916 } 2917 retval = IP_FW_PASS; 2918 l = 0; /* exit inner loop */ 2919 done = 1; /* exit outer loop */ 2920 break; 2921 #endif 2922 2923 case O_NETGRAPH: 2924 case O_NGTEE: 2925 set_match(args, f_pos, chain); 2926 args->rule.info = TARG(cmd->arg1, netgraph); 2927 if (V_fw_one_pass) 2928 args->rule.info |= IPFW_ONEPASS; 2929 retval = (cmd->opcode == O_NETGRAPH) ? 2930 IP_FW_NETGRAPH : IP_FW_NGTEE; 2931 l = 0; /* exit inner loop */ 2932 done = 1; /* exit outer loop */ 2933 break; 2934 2935 case O_SETFIB: { 2936 uint32_t fib; 2937 2938 IPFW_INC_RULE_COUNTER(f, pktlen); 2939 fib = TARG(cmd->arg1, fib) & 0x7FFF; 2940 if (fib >= rt_numfibs) 2941 fib = 0; 2942 M_SETFIB(m, fib); 2943 args->f_id.fib = fib; 2944 l = 0; /* exit inner loop */ 2945 break; 2946 } 2947 2948 case O_SETDSCP: { 2949 uint16_t code; 2950 2951 code = TARG(cmd->arg1, dscp) & 0x3F; 2952 l = 0; /* exit inner loop */ 2953 if (is_ipv4) { 2954 uint16_t old; 2955 2956 old = *(uint16_t *)ip; 2957 ip->ip_tos = (code << 2) | 2958 (ip->ip_tos & 0x03); 2959 ip->ip_sum = cksum_adjust(ip->ip_sum, 2960 old, *(uint16_t *)ip); 2961 } else if (is_ipv6) { 2962 uint8_t *v; 2963 2964 v = &((struct ip6_hdr *)ip)->ip6_vfc; 2965 *v = (*v & 0xF0) | (code >> 2); 2966 v++; 2967 *v = (*v & 0x3F) | ((code & 0x03) << 6); 2968 } else 2969 break; 2970 2971 IPFW_INC_RULE_COUNTER(f, pktlen); 2972 break; 2973 } 2974 2975 case O_NAT: 2976 l = 0; /* exit inner loop */ 2977 done = 1; /* exit outer loop */ 2978 /* 2979 * Ensure that we do not invoke NAT handler for 2980 * non IPv4 packets. Libalias expects only IPv4. 2981 */ 2982 if (!is_ipv4 || !IPFW_NAT_LOADED) { 2983 retval = IP_FW_DENY; 2984 break; 2985 } 2986 2987 struct cfg_nat *t; 2988 int nat_id; 2989 2990 set_match(args, f_pos, chain); 2991 /* Check if this is 'global' nat rule */ 2992 if (cmd->arg1 == IP_FW_NAT44_GLOBAL) { 2993 retval = ipfw_nat_ptr(args, NULL, m); 2994 break; 2995 } 2996 t = ((ipfw_insn_nat *)cmd)->nat; 2997 if (t == NULL) { 2998 nat_id = TARG(cmd->arg1, nat); 2999 t = (*lookup_nat_ptr)(&chain->nat, nat_id); 3000 3001 if (t == NULL) { 3002 retval = IP_FW_DENY; 3003 break; 3004 } 3005 if (cmd->arg1 != IP_FW_TARG) 3006 ((ipfw_insn_nat *)cmd)->nat = t; 3007 } 3008 retval = ipfw_nat_ptr(args, t, m); 3009 break; 3010 3011 case O_REASS: { 3012 int ip_off; 3013 3014 IPFW_INC_RULE_COUNTER(f, pktlen); 3015 l = 0; /* in any case exit inner loop */ 3016 ip_off = ntohs(ip->ip_off); 3017 3018 /* if not fragmented, go to next rule */ 3019 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0) 3020 break; 3021 3022 args->m = m = ip_reass(m); 3023 3024 /* 3025 * do IP header checksum fixup. 3026 */ 3027 if (m == NULL) { /* fragment got swallowed */ 3028 retval = IP_FW_DENY; 3029 } else { /* good, packet complete */ 3030 int hlen; 3031 3032 ip = mtod(m, struct ip *); 3033 hlen = ip->ip_hl << 2; 3034 ip->ip_sum = 0; 3035 if (hlen == sizeof(struct ip)) 3036 ip->ip_sum = in_cksum_hdr(ip); 3037 else 3038 ip->ip_sum = in_cksum(m, hlen); 3039 retval = IP_FW_REASS; 3040 set_match(args, f_pos, chain); 3041 } 3042 done = 1; /* exit outer loop */ 3043 break; 3044 } 3045 case O_EXTERNAL_ACTION: 3046 l = 0; /* in any case exit inner loop */ 3047 retval = ipfw_run_eaction(chain, args, 3048 cmd, &done); 3049 /* 3050 * If both @retval and @done are zero, 3051 * consider this as rule matching and 3052 * update counters. 3053 */ 3054 if (retval == 0 && done == 0) { 3055 IPFW_INC_RULE_COUNTER(f, pktlen); 3056 /* 3057 * Reset the result of the last 3058 * dynamic state lookup. 3059 * External action can change 3060 * @args content, and it may be 3061 * used for new state lookup later. 3062 */ 3063 dyn_dir = MATCH_UNKNOWN; 3064 } 3065 break; 3066 3067 default: 3068 panic("-- unknown opcode %d\n", cmd->opcode); 3069 } /* end of switch() on opcodes */ 3070 /* 3071 * if we get here with l=0, then match is irrelevant. 3072 */ 3073 3074 if (cmd->len & F_NOT) 3075 match = !match; 3076 3077 if (match) { 3078 if (cmd->len & F_OR) 3079 skip_or = 1; 3080 } else { 3081 if (!(cmd->len & F_OR)) /* not an OR block, */ 3082 break; /* try next rule */ 3083 } 3084 3085 } /* end of inner loop, scan opcodes */ 3086 #undef PULLUP_LEN 3087 3088 if (done) 3089 break; 3090 3091 /* next_rule:; */ /* try next rule */ 3092 3093 } /* end of outer for, scan rules */ 3094 3095 if (done) { 3096 struct ip_fw *rule = chain->map[f_pos]; 3097 /* Update statistics */ 3098 IPFW_INC_RULE_COUNTER(rule, pktlen); 3099 } else { 3100 retval = IP_FW_DENY; 3101 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 3102 } 3103 IPFW_PF_RUNLOCK(chain); 3104 #ifdef __FreeBSD__ 3105 if (ucred_cache != NULL) 3106 crfree(ucred_cache); 3107 #endif 3108 return (retval); 3109 3110 pullup_failed: 3111 if (V_fw_verbose) 3112 printf("ipfw: pullup failed\n"); 3113 return (IP_FW_DENY); 3114 } 3115 3116 /* 3117 * Set maximum number of tables that can be used in given VNET ipfw instance. 3118 */ 3119 #ifdef SYSCTL_NODE 3120 static int 3121 sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS) 3122 { 3123 int error; 3124 unsigned int ntables; 3125 3126 ntables = V_fw_tables_max; 3127 3128 error = sysctl_handle_int(oidp, &ntables, 0, req); 3129 /* Read operation or some error */ 3130 if ((error != 0) || (req->newptr == NULL)) 3131 return (error); 3132 3133 return (ipfw_resize_tables(&V_layer3_chain, ntables)); 3134 } 3135 3136 /* 3137 * Switches table namespace between global and per-set. 3138 */ 3139 static int 3140 sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS) 3141 { 3142 int error; 3143 unsigned int sets; 3144 3145 sets = V_fw_tables_sets; 3146 3147 error = sysctl_handle_int(oidp, &sets, 0, req); 3148 /* Read operation or some error */ 3149 if ((error != 0) || (req->newptr == NULL)) 3150 return (error); 3151 3152 return (ipfw_switch_tables_namespace(&V_layer3_chain, sets)); 3153 } 3154 #endif 3155 3156 /* 3157 * Module and VNET glue 3158 */ 3159 3160 /* 3161 * Stuff that must be initialised only on boot or module load 3162 */ 3163 static int 3164 ipfw_init(void) 3165 { 3166 int error = 0; 3167 3168 /* 3169 * Only print out this stuff the first time around, 3170 * when called from the sysinit code. 3171 */ 3172 printf("ipfw2 " 3173 #ifdef INET6 3174 "(+ipv6) " 3175 #endif 3176 "initialized, divert %s, nat %s, " 3177 "default to %s, logging ", 3178 #ifdef IPDIVERT 3179 "enabled", 3180 #else 3181 "loadable", 3182 #endif 3183 #ifdef IPFIREWALL_NAT 3184 "enabled", 3185 #else 3186 "loadable", 3187 #endif 3188 default_to_accept ? "accept" : "deny"); 3189 3190 /* 3191 * Note: V_xxx variables can be accessed here but the vnet specific 3192 * initializer may not have been called yet for the VIMAGE case. 3193 * Tuneables will have been processed. We will print out values for 3194 * the default vnet. 3195 * XXX This should all be rationalized AFTER 8.0 3196 */ 3197 if (V_fw_verbose == 0) 3198 printf("disabled\n"); 3199 else if (V_verbose_limit == 0) 3200 printf("unlimited\n"); 3201 else 3202 printf("limited to %d packets/entry by default\n", 3203 V_verbose_limit); 3204 3205 /* Check user-supplied table count for validness */ 3206 if (default_fw_tables > IPFW_TABLES_MAX) 3207 default_fw_tables = IPFW_TABLES_MAX; 3208 3209 ipfw_init_sopt_handler(); 3210 ipfw_init_obj_rewriter(); 3211 ipfw_iface_init(); 3212 return (error); 3213 } 3214 3215 /* 3216 * Called for the removal of the last instance only on module unload. 3217 */ 3218 static void 3219 ipfw_destroy(void) 3220 { 3221 3222 ipfw_iface_destroy(); 3223 ipfw_destroy_sopt_handler(); 3224 ipfw_destroy_obj_rewriter(); 3225 printf("IP firewall unloaded\n"); 3226 } 3227 3228 /* 3229 * Stuff that must be initialized for every instance 3230 * (including the first of course). 3231 */ 3232 static int 3233 vnet_ipfw_init(const void *unused) 3234 { 3235 int error, first; 3236 struct ip_fw *rule = NULL; 3237 struct ip_fw_chain *chain; 3238 3239 chain = &V_layer3_chain; 3240 3241 first = IS_DEFAULT_VNET(curvnet) ? 1 : 0; 3242 3243 /* First set up some values that are compile time options */ 3244 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 3245 V_fw_deny_unknown_exthdrs = 1; 3246 #ifdef IPFIREWALL_VERBOSE 3247 V_fw_verbose = 1; 3248 #endif 3249 #ifdef IPFIREWALL_VERBOSE_LIMIT 3250 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 3251 #endif 3252 #ifdef IPFIREWALL_NAT 3253 LIST_INIT(&chain->nat); 3254 #endif 3255 3256 /* Init shared services hash table */ 3257 ipfw_init_srv(chain); 3258 3259 ipfw_init_counters(); 3260 /* Set initial number of tables */ 3261 V_fw_tables_max = default_fw_tables; 3262 error = ipfw_init_tables(chain, first); 3263 if (error) { 3264 printf("ipfw2: setting up tables failed\n"); 3265 free(chain->map, M_IPFW); 3266 free(rule, M_IPFW); 3267 return (ENOSPC); 3268 } 3269 3270 IPFW_LOCK_INIT(chain); 3271 3272 /* fill and insert the default rule */ 3273 rule = ipfw_alloc_rule(chain, sizeof(struct ip_fw)); 3274 rule->cmd_len = 1; 3275 rule->cmd[0].len = 1; 3276 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY; 3277 chain->default_rule = rule; 3278 ipfw_add_protected_rule(chain, rule, 0); 3279 3280 ipfw_dyn_init(chain); 3281 ipfw_eaction_init(chain, first); 3282 #ifdef LINEAR_SKIPTO 3283 ipfw_init_skipto_cache(chain); 3284 #endif 3285 ipfw_bpf_init(first); 3286 3287 /* First set up some values that are compile time options */ 3288 V_ipfw_vnet_ready = 1; /* Open for business */ 3289 3290 /* 3291 * Hook the sockopt handler and pfil hooks for ipv4 and ipv6. 3292 * Even if the latter two fail we still keep the module alive 3293 * because the sockopt and layer2 paths are still useful. 3294 * ipfw[6]_hook return 0 on success, ENOENT on failure, 3295 * so we can ignore the exact return value and just set a flag. 3296 * 3297 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so 3298 * changes in the underlying (per-vnet) variables trigger 3299 * immediate hook()/unhook() calls. 3300 * In layer2 we have the same behaviour, except that V_ether_ipfw 3301 * is checked on each packet because there are no pfil hooks. 3302 */ 3303 V_ip_fw_ctl_ptr = ipfw_ctl3; 3304 error = ipfw_attach_hooks(1); 3305 return (error); 3306 } 3307 3308 /* 3309 * Called for the removal of each instance. 3310 */ 3311 static int 3312 vnet_ipfw_uninit(const void *unused) 3313 { 3314 struct ip_fw *reap; 3315 struct ip_fw_chain *chain = &V_layer3_chain; 3316 int i, last; 3317 3318 V_ipfw_vnet_ready = 0; /* tell new callers to go away */ 3319 /* 3320 * disconnect from ipv4, ipv6, layer2 and sockopt. 3321 * Then grab, release and grab again the WLOCK so we make 3322 * sure the update is propagated and nobody will be in. 3323 */ 3324 (void)ipfw_attach_hooks(0 /* detach */); 3325 V_ip_fw_ctl_ptr = NULL; 3326 3327 last = IS_DEFAULT_VNET(curvnet) ? 1 : 0; 3328 3329 IPFW_UH_WLOCK(chain); 3330 IPFW_UH_WUNLOCK(chain); 3331 3332 ipfw_dyn_uninit(0); /* run the callout_drain */ 3333 3334 IPFW_UH_WLOCK(chain); 3335 3336 reap = NULL; 3337 IPFW_WLOCK(chain); 3338 for (i = 0; i < chain->n_rules; i++) 3339 ipfw_reap_add(chain, &reap, chain->map[i]); 3340 free(chain->map, M_IPFW); 3341 #ifdef LINEAR_SKIPTO 3342 ipfw_destroy_skipto_cache(chain); 3343 #endif 3344 IPFW_WUNLOCK(chain); 3345 IPFW_UH_WUNLOCK(chain); 3346 ipfw_destroy_tables(chain, last); 3347 ipfw_eaction_uninit(chain, last); 3348 if (reap != NULL) 3349 ipfw_reap_rules(reap); 3350 vnet_ipfw_iface_destroy(chain); 3351 ipfw_destroy_srv(chain); 3352 IPFW_LOCK_DESTROY(chain); 3353 ipfw_dyn_uninit(1); /* free the remaining parts */ 3354 ipfw_destroy_counters(); 3355 ipfw_bpf_uninit(last); 3356 return (0); 3357 } 3358 3359 /* 3360 * Module event handler. 3361 * In general we have the choice of handling most of these events by the 3362 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to 3363 * use the SYSINIT handlers as they are more capable of expressing the 3364 * flow of control during module and vnet operations, so this is just 3365 * a skeleton. Note there is no SYSINIT equivalent of the module 3366 * SHUTDOWN handler, but we don't have anything to do in that case anyhow. 3367 */ 3368 static int 3369 ipfw_modevent(module_t mod, int type, void *unused) 3370 { 3371 int err = 0; 3372 3373 switch (type) { 3374 case MOD_LOAD: 3375 /* Called once at module load or 3376 * system boot if compiled in. */ 3377 break; 3378 case MOD_QUIESCE: 3379 /* Called before unload. May veto unloading. */ 3380 break; 3381 case MOD_UNLOAD: 3382 /* Called during unload. */ 3383 break; 3384 case MOD_SHUTDOWN: 3385 /* Called during system shutdown. */ 3386 break; 3387 default: 3388 err = EOPNOTSUPP; 3389 break; 3390 } 3391 return err; 3392 } 3393 3394 static moduledata_t ipfwmod = { 3395 "ipfw", 3396 ipfw_modevent, 3397 0 3398 }; 3399 3400 /* Define startup order. */ 3401 #define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_FIREWALL 3402 #define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */ 3403 #define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */ 3404 #define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */ 3405 3406 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER); 3407 FEATURE(ipfw_ctl3, "ipfw new sockopt calls"); 3408 MODULE_VERSION(ipfw, 3); 3409 /* should declare some dependencies here */ 3410 3411 /* 3412 * Starting up. Done in order after ipfwmod() has been called. 3413 * VNET_SYSINIT is also called for each existing vnet and each new vnet. 3414 */ 3415 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 3416 ipfw_init, NULL); 3417 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 3418 vnet_ipfw_init, NULL); 3419 3420 /* 3421 * Closing up shop. These are done in REVERSE ORDER, but still 3422 * after ipfwmod() has been called. Not called on reboot. 3423 * VNET_SYSUNINIT is also called for each exiting vnet as it exits. 3424 * or when the module is unloaded. 3425 */ 3426 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 3427 ipfw_destroy, NULL); 3428 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 3429 vnet_ipfw_uninit, NULL); 3430 /* end of file */ 3431