1 /*- 2 * Copyright (c) 2002-2009 Luigi Rizzo, Universita` di Pisa 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 26 #include <sys/cdefs.h> 27 __FBSDID("$FreeBSD$"); 28 29 /* 30 * The FreeBSD IP packet firewall, main file 31 */ 32 33 #include "opt_ipfw.h" 34 #include "opt_ipdivert.h" 35 #include "opt_inet.h" 36 #ifndef INET 37 #error "IPFIREWALL requires INET" 38 #endif /* INET */ 39 #include "opt_inet6.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/condvar.h> 44 #include <sys/counter.h> 45 #include <sys/eventhandler.h> 46 #include <sys/malloc.h> 47 #include <sys/mbuf.h> 48 #include <sys/kernel.h> 49 #include <sys/lock.h> 50 #include <sys/jail.h> 51 #include <sys/module.h> 52 #include <sys/priv.h> 53 #include <sys/proc.h> 54 #include <sys/rwlock.h> 55 #include <sys/rmlock.h> 56 #include <sys/socket.h> 57 #include <sys/socketvar.h> 58 #include <sys/sysctl.h> 59 #include <sys/syslog.h> 60 #include <sys/ucred.h> 61 #include <net/ethernet.h> /* for ETHERTYPE_IP */ 62 #include <net/if.h> 63 #include <net/if_var.h> 64 #include <net/route.h> 65 #include <net/pfil.h> 66 #include <net/vnet.h> 67 68 #include <netpfil/pf/pf_mtag.h> 69 70 #include <netinet/in.h> 71 #include <netinet/in_var.h> 72 #include <netinet/in_pcb.h> 73 #include <netinet/ip.h> 74 #include <netinet/ip_var.h> 75 #include <netinet/ip_icmp.h> 76 #include <netinet/ip_fw.h> 77 #include <netinet/ip_carp.h> 78 #include <netinet/pim.h> 79 #include <netinet/tcp_var.h> 80 #include <netinet/udp.h> 81 #include <netinet/udp_var.h> 82 #include <netinet/sctp.h> 83 #include <netinet/sctp_crc32.h> 84 #include <netinet/sctp_header.h> 85 86 #include <netinet/ip6.h> 87 #include <netinet/icmp6.h> 88 #include <netinet/in_fib.h> 89 #ifdef INET6 90 #include <netinet6/in6_fib.h> 91 #include <netinet6/in6_pcb.h> 92 #include <netinet6/scope6_var.h> 93 #include <netinet6/ip6_var.h> 94 #endif 95 96 #include <net/if_gre.h> /* for struct grehdr */ 97 98 #include <netpfil/ipfw/ip_fw_private.h> 99 100 #include <machine/in_cksum.h> /* XXX for in_cksum */ 101 102 #ifdef MAC 103 #include <security/mac/mac_framework.h> 104 #endif 105 106 /* 107 * static variables followed by global ones. 108 * All ipfw global variables are here. 109 */ 110 111 static VNET_DEFINE(int, fw_deny_unknown_exthdrs); 112 #define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs) 113 114 static VNET_DEFINE(int, fw_permit_single_frag6) = 1; 115 #define V_fw_permit_single_frag6 VNET(fw_permit_single_frag6) 116 117 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 118 static int default_to_accept = 1; 119 #else 120 static int default_to_accept; 121 #endif 122 123 VNET_DEFINE(int, autoinc_step); 124 VNET_DEFINE(int, fw_one_pass) = 1; 125 126 VNET_DEFINE(unsigned int, fw_tables_max); 127 VNET_DEFINE(unsigned int, fw_tables_sets) = 0; /* Don't use set-aware tables */ 128 /* Use 128 tables by default */ 129 static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT; 130 131 #ifndef LINEAR_SKIPTO 132 static int jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 133 int tablearg, int jump_backwards); 134 #define JUMP(ch, f, num, targ, back) jump_fast(ch, f, num, targ, back) 135 #else 136 static int jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num, 137 int tablearg, int jump_backwards); 138 #define JUMP(ch, f, num, targ, back) jump_linear(ch, f, num, targ, back) 139 #endif 140 141 /* 142 * Each rule belongs to one of 32 different sets (0..31). 143 * The variable set_disable contains one bit per set. 144 * If the bit is set, all rules in the corresponding set 145 * are disabled. Set RESVD_SET(31) is reserved for the default rule 146 * and rules that are not deleted by the flush command, 147 * and CANNOT be disabled. 148 * Rules in set RESVD_SET can only be deleted individually. 149 */ 150 VNET_DEFINE(u_int32_t, set_disable); 151 #define V_set_disable VNET(set_disable) 152 153 VNET_DEFINE(int, fw_verbose); 154 /* counter for ipfw_log(NULL...) */ 155 VNET_DEFINE(u_int64_t, norule_counter); 156 VNET_DEFINE(int, verbose_limit); 157 158 /* layer3_chain contains the list of rules for layer 3 */ 159 VNET_DEFINE(struct ip_fw_chain, layer3_chain); 160 161 /* ipfw_vnet_ready controls when we are open for business */ 162 VNET_DEFINE(int, ipfw_vnet_ready) = 0; 163 164 VNET_DEFINE(int, ipfw_nat_ready) = 0; 165 166 ipfw_nat_t *ipfw_nat_ptr = NULL; 167 struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int); 168 ipfw_nat_cfg_t *ipfw_nat_cfg_ptr; 169 ipfw_nat_cfg_t *ipfw_nat_del_ptr; 170 ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr; 171 ipfw_nat_cfg_t *ipfw_nat_get_log_ptr; 172 173 #ifdef SYSCTL_NODE 174 uint32_t dummy_def = IPFW_DEFAULT_RULE; 175 static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS); 176 static int sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS); 177 178 SYSBEGIN(f3) 179 180 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 181 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 182 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0, 183 "Only do a single pass through ipfw when using dummynet(4)"); 184 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, 185 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(autoinc_step), 0, 186 "Rule number auto-increment step"); 187 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, 188 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0, 189 "Log matches to ipfw rules"); 190 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, 191 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(verbose_limit), 0, 192 "Set upper limit of matches of ipfw rules logged"); 193 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD, 194 &dummy_def, 0, 195 "The default/max possible rule number."); 196 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_max, 197 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, 0, 0, sysctl_ipfw_table_num, "IU", 198 "Maximum number of concurrently used tables"); 199 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_sets, 200 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, 201 0, 0, sysctl_ipfw_tables_sets, "IU", 202 "Use per-set namespace for tables"); 203 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN, 204 &default_to_accept, 0, 205 "Make the default rule accept all packets."); 206 TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables); 207 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, 208 CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0, 209 "Number of static rules"); 210 211 #ifdef INET6 212 SYSCTL_DECL(_net_inet6_ip6); 213 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 214 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs, 215 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE, 216 &VNET_NAME(fw_deny_unknown_exthdrs), 0, 217 "Deny packets with unknown IPv6 Extension Headers"); 218 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6, 219 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE, 220 &VNET_NAME(fw_permit_single_frag6), 0, 221 "Permit single packet IPv6 fragments"); 222 #endif /* INET6 */ 223 224 SYSEND 225 226 #endif /* SYSCTL_NODE */ 227 228 229 /* 230 * Some macros used in the various matching options. 231 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 232 * Other macros just cast void * into the appropriate type 233 */ 234 #define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 235 #define TCP(p) ((struct tcphdr *)(p)) 236 #define SCTP(p) ((struct sctphdr *)(p)) 237 #define UDP(p) ((struct udphdr *)(p)) 238 #define ICMP(p) ((struct icmphdr *)(p)) 239 #define ICMP6(p) ((struct icmp6_hdr *)(p)) 240 241 static __inline int 242 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 243 { 244 int type = icmp->icmp_type; 245 246 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 247 } 248 249 #define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 250 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 251 252 static int 253 is_icmp_query(struct icmphdr *icmp) 254 { 255 int type = icmp->icmp_type; 256 257 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 258 } 259 #undef TT 260 261 /* 262 * The following checks use two arrays of 8 or 16 bits to store the 263 * bits that we want set or clear, respectively. They are in the 264 * low and high half of cmd->arg1 or cmd->d[0]. 265 * 266 * We scan options and store the bits we find set. We succeed if 267 * 268 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 269 * 270 * The code is sometimes optimized not to store additional variables. 271 */ 272 273 static int 274 flags_match(ipfw_insn *cmd, u_int8_t bits) 275 { 276 u_char want_clear; 277 bits = ~bits; 278 279 if ( ((cmd->arg1 & 0xff) & bits) != 0) 280 return 0; /* some bits we want set were clear */ 281 want_clear = (cmd->arg1 >> 8) & 0xff; 282 if ( (want_clear & bits) != want_clear) 283 return 0; /* some bits we want clear were set */ 284 return 1; 285 } 286 287 static int 288 ipopts_match(struct ip *ip, ipfw_insn *cmd) 289 { 290 int optlen, bits = 0; 291 u_char *cp = (u_char *)(ip + 1); 292 int x = (ip->ip_hl << 2) - sizeof (struct ip); 293 294 for (; x > 0; x -= optlen, cp += optlen) { 295 int opt = cp[IPOPT_OPTVAL]; 296 297 if (opt == IPOPT_EOL) 298 break; 299 if (opt == IPOPT_NOP) 300 optlen = 1; 301 else { 302 optlen = cp[IPOPT_OLEN]; 303 if (optlen <= 0 || optlen > x) 304 return 0; /* invalid or truncated */ 305 } 306 switch (opt) { 307 308 default: 309 break; 310 311 case IPOPT_LSRR: 312 bits |= IP_FW_IPOPT_LSRR; 313 break; 314 315 case IPOPT_SSRR: 316 bits |= IP_FW_IPOPT_SSRR; 317 break; 318 319 case IPOPT_RR: 320 bits |= IP_FW_IPOPT_RR; 321 break; 322 323 case IPOPT_TS: 324 bits |= IP_FW_IPOPT_TS; 325 break; 326 } 327 } 328 return (flags_match(cmd, bits)); 329 } 330 331 static int 332 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 333 { 334 int optlen, bits = 0; 335 u_char *cp = (u_char *)(tcp + 1); 336 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 337 338 for (; x > 0; x -= optlen, cp += optlen) { 339 int opt = cp[0]; 340 if (opt == TCPOPT_EOL) 341 break; 342 if (opt == TCPOPT_NOP) 343 optlen = 1; 344 else { 345 optlen = cp[1]; 346 if (optlen <= 0) 347 break; 348 } 349 350 switch (opt) { 351 352 default: 353 break; 354 355 case TCPOPT_MAXSEG: 356 bits |= IP_FW_TCPOPT_MSS; 357 break; 358 359 case TCPOPT_WINDOW: 360 bits |= IP_FW_TCPOPT_WINDOW; 361 break; 362 363 case TCPOPT_SACK_PERMITTED: 364 case TCPOPT_SACK: 365 bits |= IP_FW_TCPOPT_SACK; 366 break; 367 368 case TCPOPT_TIMESTAMP: 369 bits |= IP_FW_TCPOPT_TS; 370 break; 371 372 } 373 } 374 return (flags_match(cmd, bits)); 375 } 376 377 static int 378 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain, 379 uint32_t *tablearg) 380 { 381 382 if (ifp == NULL) /* no iface with this packet, match fails */ 383 return (0); 384 385 /* Check by name or by IP address */ 386 if (cmd->name[0] != '\0') { /* match by name */ 387 if (cmd->name[0] == '\1') /* use tablearg to match */ 388 return ipfw_lookup_table(chain, cmd->p.kidx, 0, 389 &ifp->if_index, tablearg); 390 /* Check name */ 391 if (cmd->p.glob) { 392 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 393 return(1); 394 } else { 395 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 396 return(1); 397 } 398 } else { 399 #if !defined(USERSPACE) && defined(__FreeBSD__) /* and OSX too ? */ 400 struct ifaddr *ia; 401 402 if_addr_rlock(ifp); 403 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 404 if (ia->ifa_addr->sa_family != AF_INET) 405 continue; 406 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 407 (ia->ifa_addr))->sin_addr.s_addr) { 408 if_addr_runlock(ifp); 409 return(1); /* match */ 410 } 411 } 412 if_addr_runlock(ifp); 413 #endif /* __FreeBSD__ */ 414 } 415 return(0); /* no match, fail ... */ 416 } 417 418 /* 419 * The verify_path function checks if a route to the src exists and 420 * if it is reachable via ifp (when provided). 421 * 422 * The 'verrevpath' option checks that the interface that an IP packet 423 * arrives on is the same interface that traffic destined for the 424 * packet's source address would be routed out of. 425 * The 'versrcreach' option just checks that the source address is 426 * reachable via any route (except default) in the routing table. 427 * These two are a measure to block forged packets. This is also 428 * commonly known as "anti-spoofing" or Unicast Reverse Path 429 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 430 * is purposely reminiscent of the Cisco IOS command, 431 * 432 * ip verify unicast reverse-path 433 * ip verify unicast source reachable-via any 434 * 435 * which implements the same functionality. But note that the syntax 436 * is misleading, and the check may be performed on all IP packets 437 * whether unicast, multicast, or broadcast. 438 */ 439 static int 440 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib) 441 { 442 #if defined(USERSPACE) || !defined(__FreeBSD__) 443 return 0; 444 #else 445 struct nhop4_basic nh4; 446 447 if (fib4_lookup_nh_basic(fib, src, NHR_IFAIF, 0, &nh4) != 0) 448 return (0); 449 450 /* 451 * If ifp is provided, check for equality with rtentry. 452 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 453 * in order to pass packets injected back by if_simloop(): 454 * routing entry (via lo0) for our own address 455 * may exist, so we need to handle routing assymetry. 456 */ 457 if (ifp != NULL && ifp != nh4.nh_ifp) 458 return (0); 459 460 /* if no ifp provided, check if rtentry is not default route */ 461 if (ifp == NULL && (nh4.nh_flags & NHF_DEFAULT) != 0) 462 return (0); 463 464 /* or if this is a blackhole/reject route */ 465 if (ifp == NULL && (nh4.nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0) 466 return (0); 467 468 /* found valid route */ 469 return 1; 470 #endif /* __FreeBSD__ */ 471 } 472 473 /* 474 * Generate an SCTP packet containing an ABORT chunk. The verification tag 475 * is given by vtag. The T-bit is set in the ABORT chunk if and only if 476 * reflected is not 0. 477 */ 478 479 static struct mbuf * 480 ipfw_send_abort(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t vtag, 481 int reflected) 482 { 483 struct mbuf *m; 484 struct ip *ip; 485 #ifdef INET6 486 struct ip6_hdr *ip6; 487 #endif 488 struct sctphdr *sctp; 489 struct sctp_chunkhdr *chunk; 490 u_int16_t hlen, plen, tlen; 491 492 MGETHDR(m, M_NOWAIT, MT_DATA); 493 if (m == NULL) 494 return (NULL); 495 496 M_SETFIB(m, id->fib); 497 #ifdef MAC 498 if (replyto != NULL) 499 mac_netinet_firewall_reply(replyto, m); 500 else 501 mac_netinet_firewall_send(m); 502 #else 503 (void)replyto; /* don't warn about unused arg */ 504 #endif 505 506 switch (id->addr_type) { 507 case 4: 508 hlen = sizeof(struct ip); 509 break; 510 #ifdef INET6 511 case 6: 512 hlen = sizeof(struct ip6_hdr); 513 break; 514 #endif 515 default: 516 /* XXX: log me?!? */ 517 FREE_PKT(m); 518 return (NULL); 519 } 520 plen = sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr); 521 tlen = hlen + plen; 522 m->m_data += max_linkhdr; 523 m->m_flags |= M_SKIP_FIREWALL; 524 m->m_pkthdr.len = m->m_len = tlen; 525 m->m_pkthdr.rcvif = NULL; 526 bzero(m->m_data, tlen); 527 528 switch (id->addr_type) { 529 case 4: 530 ip = mtod(m, struct ip *); 531 532 ip->ip_v = 4; 533 ip->ip_hl = sizeof(struct ip) >> 2; 534 ip->ip_tos = IPTOS_LOWDELAY; 535 ip->ip_len = htons(tlen); 536 ip->ip_id = htons(0); 537 ip->ip_off = htons(0); 538 ip->ip_ttl = V_ip_defttl; 539 ip->ip_p = IPPROTO_SCTP; 540 ip->ip_sum = 0; 541 ip->ip_src.s_addr = htonl(id->dst_ip); 542 ip->ip_dst.s_addr = htonl(id->src_ip); 543 544 sctp = (struct sctphdr *)(ip + 1); 545 break; 546 #ifdef INET6 547 case 6: 548 ip6 = mtod(m, struct ip6_hdr *); 549 550 ip6->ip6_vfc = IPV6_VERSION; 551 ip6->ip6_plen = htons(plen); 552 ip6->ip6_nxt = IPPROTO_SCTP; 553 ip6->ip6_hlim = IPV6_DEFHLIM; 554 ip6->ip6_src = id->dst_ip6; 555 ip6->ip6_dst = id->src_ip6; 556 557 sctp = (struct sctphdr *)(ip6 + 1); 558 break; 559 #endif 560 } 561 562 sctp->src_port = htons(id->dst_port); 563 sctp->dest_port = htons(id->src_port); 564 sctp->v_tag = htonl(vtag); 565 sctp->checksum = htonl(0); 566 567 chunk = (struct sctp_chunkhdr *)(sctp + 1); 568 chunk->chunk_type = SCTP_ABORT_ASSOCIATION; 569 chunk->chunk_flags = 0; 570 if (reflected != 0) { 571 chunk->chunk_flags |= SCTP_HAD_NO_TCB; 572 } 573 chunk->chunk_length = htons(sizeof(struct sctp_chunkhdr)); 574 575 sctp->checksum = sctp_calculate_cksum(m, hlen); 576 577 return (m); 578 } 579 580 /* 581 * Generate a TCP packet, containing either a RST or a keepalive. 582 * When flags & TH_RST, we are sending a RST packet, because of a 583 * "reset" action matched the packet. 584 * Otherwise we are sending a keepalive, and flags & TH_ 585 * The 'replyto' mbuf is the mbuf being replied to, if any, and is required 586 * so that MAC can label the reply appropriately. 587 */ 588 struct mbuf * 589 ipfw_send_pkt(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t seq, 590 u_int32_t ack, int flags) 591 { 592 struct mbuf *m = NULL; /* stupid compiler */ 593 struct ip *h = NULL; /* stupid compiler */ 594 #ifdef INET6 595 struct ip6_hdr *h6 = NULL; 596 #endif 597 struct tcphdr *th = NULL; 598 int len, dir; 599 600 MGETHDR(m, M_NOWAIT, MT_DATA); 601 if (m == NULL) 602 return (NULL); 603 604 M_SETFIB(m, id->fib); 605 #ifdef MAC 606 if (replyto != NULL) 607 mac_netinet_firewall_reply(replyto, m); 608 else 609 mac_netinet_firewall_send(m); 610 #else 611 (void)replyto; /* don't warn about unused arg */ 612 #endif 613 614 switch (id->addr_type) { 615 case 4: 616 len = sizeof(struct ip) + sizeof(struct tcphdr); 617 break; 618 #ifdef INET6 619 case 6: 620 len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 621 break; 622 #endif 623 default: 624 /* XXX: log me?!? */ 625 FREE_PKT(m); 626 return (NULL); 627 } 628 dir = ((flags & (TH_SYN | TH_RST)) == TH_SYN); 629 630 m->m_data += max_linkhdr; 631 m->m_flags |= M_SKIP_FIREWALL; 632 m->m_pkthdr.len = m->m_len = len; 633 m->m_pkthdr.rcvif = NULL; 634 bzero(m->m_data, len); 635 636 switch (id->addr_type) { 637 case 4: 638 h = mtod(m, struct ip *); 639 640 /* prepare for checksum */ 641 h->ip_p = IPPROTO_TCP; 642 h->ip_len = htons(sizeof(struct tcphdr)); 643 if (dir) { 644 h->ip_src.s_addr = htonl(id->src_ip); 645 h->ip_dst.s_addr = htonl(id->dst_ip); 646 } else { 647 h->ip_src.s_addr = htonl(id->dst_ip); 648 h->ip_dst.s_addr = htonl(id->src_ip); 649 } 650 651 th = (struct tcphdr *)(h + 1); 652 break; 653 #ifdef INET6 654 case 6: 655 h6 = mtod(m, struct ip6_hdr *); 656 657 /* prepare for checksum */ 658 h6->ip6_nxt = IPPROTO_TCP; 659 h6->ip6_plen = htons(sizeof(struct tcphdr)); 660 if (dir) { 661 h6->ip6_src = id->src_ip6; 662 h6->ip6_dst = id->dst_ip6; 663 } else { 664 h6->ip6_src = id->dst_ip6; 665 h6->ip6_dst = id->src_ip6; 666 } 667 668 th = (struct tcphdr *)(h6 + 1); 669 break; 670 #endif 671 } 672 673 if (dir) { 674 th->th_sport = htons(id->src_port); 675 th->th_dport = htons(id->dst_port); 676 } else { 677 th->th_sport = htons(id->dst_port); 678 th->th_dport = htons(id->src_port); 679 } 680 th->th_off = sizeof(struct tcphdr) >> 2; 681 682 if (flags & TH_RST) { 683 if (flags & TH_ACK) { 684 th->th_seq = htonl(ack); 685 th->th_flags = TH_RST; 686 } else { 687 if (flags & TH_SYN) 688 seq++; 689 th->th_ack = htonl(seq); 690 th->th_flags = TH_RST | TH_ACK; 691 } 692 } else { 693 /* 694 * Keepalive - use caller provided sequence numbers 695 */ 696 th->th_seq = htonl(seq); 697 th->th_ack = htonl(ack); 698 th->th_flags = TH_ACK; 699 } 700 701 switch (id->addr_type) { 702 case 4: 703 th->th_sum = in_cksum(m, len); 704 705 /* finish the ip header */ 706 h->ip_v = 4; 707 h->ip_hl = sizeof(*h) >> 2; 708 h->ip_tos = IPTOS_LOWDELAY; 709 h->ip_off = htons(0); 710 h->ip_len = htons(len); 711 h->ip_ttl = V_ip_defttl; 712 h->ip_sum = 0; 713 break; 714 #ifdef INET6 715 case 6: 716 th->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(*h6), 717 sizeof(struct tcphdr)); 718 719 /* finish the ip6 header */ 720 h6->ip6_vfc |= IPV6_VERSION; 721 h6->ip6_hlim = IPV6_DEFHLIM; 722 break; 723 #endif 724 } 725 726 return (m); 727 } 728 729 #ifdef INET6 730 /* 731 * ipv6 specific rules here... 732 */ 733 static __inline int 734 icmp6type_match (int type, ipfw_insn_u32 *cmd) 735 { 736 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 737 } 738 739 static int 740 flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 741 { 742 int i; 743 for (i=0; i <= cmd->o.arg1; ++i ) 744 if (curr_flow == cmd->d[i] ) 745 return 1; 746 return 0; 747 } 748 749 /* support for IP6_*_ME opcodes */ 750 static const struct in6_addr lla_mask = {{{ 751 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 752 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff 753 }}}; 754 755 static int 756 ipfw_localip6(struct in6_addr *in6) 757 { 758 struct rm_priotracker in6_ifa_tracker; 759 struct in6_ifaddr *ia; 760 761 if (IN6_IS_ADDR_MULTICAST(in6)) 762 return (0); 763 764 if (!IN6_IS_ADDR_LINKLOCAL(in6)) 765 return (in6_localip(in6)); 766 767 IN6_IFADDR_RLOCK(&in6_ifa_tracker); 768 TAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) { 769 if (!IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) 770 continue; 771 if (IN6_ARE_MASKED_ADDR_EQUAL(&ia->ia_addr.sin6_addr, 772 in6, &lla_mask)) { 773 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 774 return (1); 775 } 776 } 777 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 778 return (0); 779 } 780 781 static int 782 verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib) 783 { 784 struct nhop6_basic nh6; 785 786 if (IN6_IS_SCOPE_LINKLOCAL(src)) 787 return (1); 788 789 if (fib6_lookup_nh_basic(fib, src, 0, NHR_IFAIF, 0, &nh6) != 0) 790 return (0); 791 792 /* If ifp is provided, check for equality with route table. */ 793 if (ifp != NULL && ifp != nh6.nh_ifp) 794 return (0); 795 796 /* if no ifp provided, check if rtentry is not default route */ 797 if (ifp == NULL && (nh6.nh_flags & NHF_DEFAULT) != 0) 798 return (0); 799 800 /* or if this is a blackhole/reject route */ 801 if (ifp == NULL && (nh6.nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0) 802 return (0); 803 804 /* found valid route */ 805 return 1; 806 } 807 808 static int 809 is_icmp6_query(int icmp6_type) 810 { 811 if ((icmp6_type <= ICMP6_MAXTYPE) && 812 (icmp6_type == ICMP6_ECHO_REQUEST || 813 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 814 icmp6_type == ICMP6_WRUREQUEST || 815 icmp6_type == ICMP6_FQDN_QUERY || 816 icmp6_type == ICMP6_NI_QUERY)) 817 return (1); 818 819 return (0); 820 } 821 822 static void 823 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 824 { 825 struct mbuf *m; 826 827 m = args->m; 828 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 829 struct tcphdr *tcp; 830 tcp = (struct tcphdr *)((char *)ip6 + hlen); 831 832 if ((tcp->th_flags & TH_RST) == 0) { 833 struct mbuf *m0; 834 m0 = ipfw_send_pkt(args->m, &(args->f_id), 835 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 836 tcp->th_flags | TH_RST); 837 if (m0 != NULL) 838 ip6_output(m0, NULL, NULL, 0, NULL, NULL, 839 NULL); 840 } 841 FREE_PKT(m); 842 } else if (code == ICMP6_UNREACH_ABORT && 843 args->f_id.proto == IPPROTO_SCTP) { 844 struct mbuf *m0; 845 struct sctphdr *sctp; 846 u_int32_t v_tag; 847 int reflected; 848 849 sctp = (struct sctphdr *)((char *)ip6 + hlen); 850 reflected = 1; 851 v_tag = ntohl(sctp->v_tag); 852 /* Investigate the first chunk header if available */ 853 if (m->m_len >= hlen + sizeof(struct sctphdr) + 854 sizeof(struct sctp_chunkhdr)) { 855 struct sctp_chunkhdr *chunk; 856 857 chunk = (struct sctp_chunkhdr *)(sctp + 1); 858 switch (chunk->chunk_type) { 859 case SCTP_INITIATION: 860 /* 861 * Packets containing an INIT chunk MUST have 862 * a zero v-tag. 863 */ 864 if (v_tag != 0) { 865 v_tag = 0; 866 break; 867 } 868 /* INIT chunk MUST NOT be bundled */ 869 if (m->m_pkthdr.len > 870 hlen + sizeof(struct sctphdr) + 871 ntohs(chunk->chunk_length) + 3) { 872 break; 873 } 874 /* Use the initiate tag if available */ 875 if ((m->m_len >= hlen + sizeof(struct sctphdr) + 876 sizeof(struct sctp_chunkhdr) + 877 offsetof(struct sctp_init, a_rwnd))) { 878 struct sctp_init *init; 879 880 init = (struct sctp_init *)(chunk + 1); 881 v_tag = ntohl(init->initiate_tag); 882 reflected = 0; 883 } 884 break; 885 case SCTP_ABORT_ASSOCIATION: 886 /* 887 * If the packet contains an ABORT chunk, don't 888 * reply. 889 * XXX: We should search through all chunks, 890 * but don't do to avoid attacks. 891 */ 892 v_tag = 0; 893 break; 894 } 895 } 896 if (v_tag == 0) { 897 m0 = NULL; 898 } else { 899 m0 = ipfw_send_abort(args->m, &(args->f_id), v_tag, 900 reflected); 901 } 902 if (m0 != NULL) 903 ip6_output(m0, NULL, NULL, 0, NULL, NULL, NULL); 904 FREE_PKT(m); 905 } else if (code != ICMP6_UNREACH_RST && code != ICMP6_UNREACH_ABORT) { 906 /* Send an ICMPv6 unreach. */ 907 #if 0 908 /* 909 * Unlike above, the mbufs need to line up with the ip6 hdr, 910 * as the contents are read. We need to m_adj() the 911 * needed amount. 912 * The mbuf will however be thrown away so we can adjust it. 913 * Remember we did an m_pullup on it already so we 914 * can make some assumptions about contiguousness. 915 */ 916 if (args->L3offset) 917 m_adj(m, args->L3offset); 918 #endif 919 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 920 } else 921 FREE_PKT(m); 922 923 args->m = NULL; 924 } 925 926 #endif /* INET6 */ 927 928 929 /* 930 * sends a reject message, consuming the mbuf passed as an argument. 931 */ 932 static void 933 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip) 934 { 935 936 #if 0 937 /* XXX When ip is not guaranteed to be at mtod() we will 938 * need to account for this */ 939 * The mbuf will however be thrown away so we can adjust it. 940 * Remember we did an m_pullup on it already so we 941 * can make some assumptions about contiguousness. 942 */ 943 if (args->L3offset) 944 m_adj(m, args->L3offset); 945 #endif 946 if (code != ICMP_REJECT_RST && code != ICMP_REJECT_ABORT) { 947 /* Send an ICMP unreach */ 948 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 949 } else if (code == ICMP_REJECT_RST && args->f_id.proto == IPPROTO_TCP) { 950 struct tcphdr *const tcp = 951 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 952 if ( (tcp->th_flags & TH_RST) == 0) { 953 struct mbuf *m; 954 m = ipfw_send_pkt(args->m, &(args->f_id), 955 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 956 tcp->th_flags | TH_RST); 957 if (m != NULL) 958 ip_output(m, NULL, NULL, 0, NULL, NULL); 959 } 960 FREE_PKT(args->m); 961 } else if (code == ICMP_REJECT_ABORT && 962 args->f_id.proto == IPPROTO_SCTP) { 963 struct mbuf *m; 964 struct sctphdr *sctp; 965 struct sctp_chunkhdr *chunk; 966 struct sctp_init *init; 967 u_int32_t v_tag; 968 int reflected; 969 970 sctp = L3HDR(struct sctphdr, mtod(args->m, struct ip *)); 971 reflected = 1; 972 v_tag = ntohl(sctp->v_tag); 973 if (iplen >= (ip->ip_hl << 2) + sizeof(struct sctphdr) + 974 sizeof(struct sctp_chunkhdr)) { 975 /* Look at the first chunk header if available */ 976 chunk = (struct sctp_chunkhdr *)(sctp + 1); 977 switch (chunk->chunk_type) { 978 case SCTP_INITIATION: 979 /* 980 * Packets containing an INIT chunk MUST have 981 * a zero v-tag. 982 */ 983 if (v_tag != 0) { 984 v_tag = 0; 985 break; 986 } 987 /* INIT chunk MUST NOT be bundled */ 988 if (iplen > 989 (ip->ip_hl << 2) + sizeof(struct sctphdr) + 990 ntohs(chunk->chunk_length) + 3) { 991 break; 992 } 993 /* Use the initiate tag if available */ 994 if ((iplen >= (ip->ip_hl << 2) + 995 sizeof(struct sctphdr) + 996 sizeof(struct sctp_chunkhdr) + 997 offsetof(struct sctp_init, a_rwnd))) { 998 init = (struct sctp_init *)(chunk + 1); 999 v_tag = ntohl(init->initiate_tag); 1000 reflected = 0; 1001 } 1002 break; 1003 case SCTP_ABORT_ASSOCIATION: 1004 /* 1005 * If the packet contains an ABORT chunk, don't 1006 * reply. 1007 * XXX: We should search through all chunks, 1008 * but don't do to avoid attacks. 1009 */ 1010 v_tag = 0; 1011 break; 1012 } 1013 } 1014 if (v_tag == 0) { 1015 m = NULL; 1016 } else { 1017 m = ipfw_send_abort(args->m, &(args->f_id), v_tag, 1018 reflected); 1019 } 1020 if (m != NULL) 1021 ip_output(m, NULL, NULL, 0, NULL, NULL); 1022 FREE_PKT(args->m); 1023 } else 1024 FREE_PKT(args->m); 1025 args->m = NULL; 1026 } 1027 1028 /* 1029 * Support for uid/gid/jail lookup. These tests are expensive 1030 * (because we may need to look into the list of active sockets) 1031 * so we cache the results. ugid_lookupp is 0 if we have not 1032 * yet done a lookup, 1 if we succeeded, and -1 if we tried 1033 * and failed. The function always returns the match value. 1034 * We could actually spare the variable and use *uc, setting 1035 * it to '(void *)check_uidgid if we have no info, NULL if 1036 * we tried and failed, or any other value if successful. 1037 */ 1038 static int 1039 check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp, 1040 struct ucred **uc) 1041 { 1042 #if defined(USERSPACE) 1043 return 0; // not supported in userspace 1044 #else 1045 #ifndef __FreeBSD__ 1046 /* XXX */ 1047 return cred_check(insn, proto, oif, 1048 dst_ip, dst_port, src_ip, src_port, 1049 (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb); 1050 #else /* FreeBSD */ 1051 struct in_addr src_ip, dst_ip; 1052 struct inpcbinfo *pi; 1053 struct ipfw_flow_id *id; 1054 struct inpcb *pcb, *inp; 1055 struct ifnet *oif; 1056 int lookupflags; 1057 int match; 1058 1059 id = &args->f_id; 1060 inp = args->inp; 1061 oif = args->oif; 1062 1063 /* 1064 * Check to see if the UDP or TCP stack supplied us with 1065 * the PCB. If so, rather then holding a lock and looking 1066 * up the PCB, we can use the one that was supplied. 1067 */ 1068 if (inp && *ugid_lookupp == 0) { 1069 INP_LOCK_ASSERT(inp); 1070 if (inp->inp_socket != NULL) { 1071 *uc = crhold(inp->inp_cred); 1072 *ugid_lookupp = 1; 1073 } else 1074 *ugid_lookupp = -1; 1075 } 1076 /* 1077 * If we have already been here and the packet has no 1078 * PCB entry associated with it, then we can safely 1079 * assume that this is a no match. 1080 */ 1081 if (*ugid_lookupp == -1) 1082 return (0); 1083 if (id->proto == IPPROTO_TCP) { 1084 lookupflags = 0; 1085 pi = &V_tcbinfo; 1086 } else if (id->proto == IPPROTO_UDP) { 1087 lookupflags = INPLOOKUP_WILDCARD; 1088 pi = &V_udbinfo; 1089 } else 1090 return 0; 1091 lookupflags |= INPLOOKUP_RLOCKPCB; 1092 match = 0; 1093 if (*ugid_lookupp == 0) { 1094 if (id->addr_type == 6) { 1095 #ifdef INET6 1096 if (oif == NULL) 1097 pcb = in6_pcblookup_mbuf(pi, 1098 &id->src_ip6, htons(id->src_port), 1099 &id->dst_ip6, htons(id->dst_port), 1100 lookupflags, oif, args->m); 1101 else 1102 pcb = in6_pcblookup_mbuf(pi, 1103 &id->dst_ip6, htons(id->dst_port), 1104 &id->src_ip6, htons(id->src_port), 1105 lookupflags, oif, args->m); 1106 #else 1107 *ugid_lookupp = -1; 1108 return (0); 1109 #endif 1110 } else { 1111 src_ip.s_addr = htonl(id->src_ip); 1112 dst_ip.s_addr = htonl(id->dst_ip); 1113 if (oif == NULL) 1114 pcb = in_pcblookup_mbuf(pi, 1115 src_ip, htons(id->src_port), 1116 dst_ip, htons(id->dst_port), 1117 lookupflags, oif, args->m); 1118 else 1119 pcb = in_pcblookup_mbuf(pi, 1120 dst_ip, htons(id->dst_port), 1121 src_ip, htons(id->src_port), 1122 lookupflags, oif, args->m); 1123 } 1124 if (pcb != NULL) { 1125 INP_RLOCK_ASSERT(pcb); 1126 *uc = crhold(pcb->inp_cred); 1127 *ugid_lookupp = 1; 1128 INP_RUNLOCK(pcb); 1129 } 1130 if (*ugid_lookupp == 0) { 1131 /* 1132 * We tried and failed, set the variable to -1 1133 * so we will not try again on this packet. 1134 */ 1135 *ugid_lookupp = -1; 1136 return (0); 1137 } 1138 } 1139 if (insn->o.opcode == O_UID) 1140 match = ((*uc)->cr_uid == (uid_t)insn->d[0]); 1141 else if (insn->o.opcode == O_GID) 1142 match = groupmember((gid_t)insn->d[0], *uc); 1143 else if (insn->o.opcode == O_JAIL) 1144 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]); 1145 return (match); 1146 #endif /* __FreeBSD__ */ 1147 #endif /* not supported in userspace */ 1148 } 1149 1150 /* 1151 * Helper function to set args with info on the rule after the matching 1152 * one. slot is precise, whereas we guess rule_id as they are 1153 * assigned sequentially. 1154 */ 1155 static inline void 1156 set_match(struct ip_fw_args *args, int slot, 1157 struct ip_fw_chain *chain) 1158 { 1159 args->rule.chain_id = chain->id; 1160 args->rule.slot = slot + 1; /* we use 0 as a marker */ 1161 args->rule.rule_id = 1 + chain->map[slot]->id; 1162 args->rule.rulenum = chain->map[slot]->rulenum; 1163 } 1164 1165 #ifndef LINEAR_SKIPTO 1166 /* 1167 * Helper function to enable cached rule lookups using 1168 * cached_id and cached_pos fields in ipfw rule. 1169 */ 1170 static int 1171 jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 1172 int tablearg, int jump_backwards) 1173 { 1174 int f_pos; 1175 1176 /* If possible use cached f_pos (in f->cached_pos), 1177 * whose version is written in f->cached_id 1178 * (horrible hacks to avoid changing the ABI). 1179 */ 1180 if (num != IP_FW_TARG && f->cached_id == chain->id) 1181 f_pos = f->cached_pos; 1182 else { 1183 int i = IP_FW_ARG_TABLEARG(chain, num, skipto); 1184 /* make sure we do not jump backward */ 1185 if (jump_backwards == 0 && i <= f->rulenum) 1186 i = f->rulenum + 1; 1187 if (chain->idxmap != NULL) 1188 f_pos = chain->idxmap[i]; 1189 else 1190 f_pos = ipfw_find_rule(chain, i, 0); 1191 /* update the cache */ 1192 if (num != IP_FW_TARG) { 1193 f->cached_id = chain->id; 1194 f->cached_pos = f_pos; 1195 } 1196 } 1197 1198 return (f_pos); 1199 } 1200 #else 1201 /* 1202 * Helper function to enable real fast rule lookups. 1203 */ 1204 static int 1205 jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num, 1206 int tablearg, int jump_backwards) 1207 { 1208 int f_pos; 1209 1210 num = IP_FW_ARG_TABLEARG(chain, num, skipto); 1211 /* make sure we do not jump backward */ 1212 if (jump_backwards == 0 && num <= f->rulenum) 1213 num = f->rulenum + 1; 1214 f_pos = chain->idxmap[num]; 1215 1216 return (f_pos); 1217 } 1218 #endif 1219 1220 #define TARG(k, f) IP_FW_ARG_TABLEARG(chain, k, f) 1221 /* 1222 * The main check routine for the firewall. 1223 * 1224 * All arguments are in args so we can modify them and return them 1225 * back to the caller. 1226 * 1227 * Parameters: 1228 * 1229 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 1230 * Starts with the IP header. 1231 * args->eh (in) Mac header if present, NULL for layer3 packet. 1232 * args->L3offset Number of bytes bypassed if we came from L2. 1233 * e.g. often sizeof(eh) ** NOTYET ** 1234 * args->oif Outgoing interface, NULL if packet is incoming. 1235 * The incoming interface is in the mbuf. (in) 1236 * args->divert_rule (in/out) 1237 * Skip up to the first rule past this rule number; 1238 * upon return, non-zero port number for divert or tee. 1239 * 1240 * args->rule Pointer to the last matching rule (in/out) 1241 * args->next_hop Socket we are forwarding to (out). 1242 * args->next_hop6 IPv6 next hop we are forwarding to (out). 1243 * args->f_id Addresses grabbed from the packet (out) 1244 * args->rule.info a cookie depending on rule action 1245 * 1246 * Return value: 1247 * 1248 * IP_FW_PASS the packet must be accepted 1249 * IP_FW_DENY the packet must be dropped 1250 * IP_FW_DIVERT divert packet, port in m_tag 1251 * IP_FW_TEE tee packet, port in m_tag 1252 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 1253 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 1254 * args->rule contains the matching rule, 1255 * args->rule.info has additional information. 1256 * 1257 */ 1258 int 1259 ipfw_chk(struct ip_fw_args *args) 1260 { 1261 1262 /* 1263 * Local variables holding state while processing a packet: 1264 * 1265 * IMPORTANT NOTE: to speed up the processing of rules, there 1266 * are some assumption on the values of the variables, which 1267 * are documented here. Should you change them, please check 1268 * the implementation of the various instructions to make sure 1269 * that they still work. 1270 * 1271 * args->eh The MAC header. It is non-null for a layer2 1272 * packet, it is NULL for a layer-3 packet. 1273 * **notyet** 1274 * args->L3offset Offset in the packet to the L3 (IP or equiv.) header. 1275 * 1276 * m | args->m Pointer to the mbuf, as received from the caller. 1277 * It may change if ipfw_chk() does an m_pullup, or if it 1278 * consumes the packet because it calls send_reject(). 1279 * XXX This has to change, so that ipfw_chk() never modifies 1280 * or consumes the buffer. 1281 * ip is the beginning of the ip(4 or 6) header. 1282 * Calculated by adding the L3offset to the start of data. 1283 * (Until we start using L3offset, the packet is 1284 * supposed to start with the ip header). 1285 */ 1286 struct mbuf *m = args->m; 1287 struct ip *ip = mtod(m, struct ip *); 1288 1289 /* 1290 * For rules which contain uid/gid or jail constraints, cache 1291 * a copy of the users credentials after the pcb lookup has been 1292 * executed. This will speed up the processing of rules with 1293 * these types of constraints, as well as decrease contention 1294 * on pcb related locks. 1295 */ 1296 #ifndef __FreeBSD__ 1297 struct bsd_ucred ucred_cache; 1298 #else 1299 struct ucred *ucred_cache = NULL; 1300 #endif 1301 int ucred_lookup = 0; 1302 1303 /* 1304 * oif | args->oif If NULL, ipfw_chk has been called on the 1305 * inbound path (ether_input, ip_input). 1306 * If non-NULL, ipfw_chk has been called on the outbound path 1307 * (ether_output, ip_output). 1308 */ 1309 struct ifnet *oif = args->oif; 1310 1311 int f_pos = 0; /* index of current rule in the array */ 1312 int retval = 0; 1313 1314 /* 1315 * hlen The length of the IP header. 1316 */ 1317 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 1318 1319 /* 1320 * offset The offset of a fragment. offset != 0 means that 1321 * we have a fragment at this offset of an IPv4 packet. 1322 * offset == 0 means that (if this is an IPv4 packet) 1323 * this is the first or only fragment. 1324 * For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header 1325 * or there is a single packet fragment (fragment header added 1326 * without needed). We will treat a single packet fragment as if 1327 * there was no fragment header (or log/block depending on the 1328 * V_fw_permit_single_frag6 sysctl setting). 1329 */ 1330 u_short offset = 0; 1331 u_short ip6f_mf = 0; 1332 1333 /* 1334 * Local copies of addresses. They are only valid if we have 1335 * an IP packet. 1336 * 1337 * proto The protocol. Set to 0 for non-ip packets, 1338 * or to the protocol read from the packet otherwise. 1339 * proto != 0 means that we have an IPv4 packet. 1340 * 1341 * src_port, dst_port port numbers, in HOST format. Only 1342 * valid for TCP and UDP packets. 1343 * 1344 * src_ip, dst_ip ip addresses, in NETWORK format. 1345 * Only valid for IPv4 packets. 1346 */ 1347 uint8_t proto; 1348 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 1349 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 1350 int iplen = 0; 1351 int pktlen; 1352 uint16_t etype = 0; /* Host order stored ether type */ 1353 1354 /* 1355 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 1356 * MATCH_NONE when checked and not matched (q = NULL), 1357 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) 1358 */ 1359 int dyn_dir = MATCH_UNKNOWN; 1360 uint16_t dyn_name = 0; 1361 struct ip_fw *q = NULL; 1362 struct ip_fw_chain *chain = &V_layer3_chain; 1363 1364 /* 1365 * We store in ulp a pointer to the upper layer protocol header. 1366 * In the ipv4 case this is easy to determine from the header, 1367 * but for ipv6 we might have some additional headers in the middle. 1368 * ulp is NULL if not found. 1369 */ 1370 void *ulp = NULL; /* upper layer protocol pointer. */ 1371 1372 /* XXX ipv6 variables */ 1373 int is_ipv6 = 0; 1374 uint8_t icmp6_type = 0; 1375 uint16_t ext_hd = 0; /* bits vector for extension header filtering */ 1376 /* end of ipv6 variables */ 1377 1378 int is_ipv4 = 0; 1379 1380 int done = 0; /* flag to exit the outer loop */ 1381 1382 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready)) 1383 return (IP_FW_PASS); /* accept */ 1384 1385 dst_ip.s_addr = 0; /* make sure it is initialized */ 1386 src_ip.s_addr = 0; /* make sure it is initialized */ 1387 pktlen = m->m_pkthdr.len; 1388 args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */ 1389 proto = args->f_id.proto = 0; /* mark f_id invalid */ 1390 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ 1391 1392 /* 1393 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 1394 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 1395 * pointer might become stale after other pullups (but we never use it 1396 * this way). 1397 */ 1398 #define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T)) 1399 #define PULLUP_LEN(_len, p, T) \ 1400 do { \ 1401 int x = (_len) + T; \ 1402 if ((m)->m_len < x) { \ 1403 args->m = m = m_pullup(m, x); \ 1404 if (m == NULL) \ 1405 goto pullup_failed; \ 1406 } \ 1407 p = (mtod(m, char *) + (_len)); \ 1408 } while (0) 1409 1410 /* 1411 * if we have an ether header, 1412 */ 1413 if (args->eh) 1414 etype = ntohs(args->eh->ether_type); 1415 1416 /* Identify IP packets and fill up variables. */ 1417 if (pktlen >= sizeof(struct ip6_hdr) && 1418 (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) { 1419 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 1420 is_ipv6 = 1; 1421 args->f_id.addr_type = 6; 1422 hlen = sizeof(struct ip6_hdr); 1423 proto = ip6->ip6_nxt; 1424 1425 /* Search extension headers to find upper layer protocols */ 1426 while (ulp == NULL && offset == 0) { 1427 switch (proto) { 1428 case IPPROTO_ICMPV6: 1429 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 1430 icmp6_type = ICMP6(ulp)->icmp6_type; 1431 break; 1432 1433 case IPPROTO_TCP: 1434 PULLUP_TO(hlen, ulp, struct tcphdr); 1435 dst_port = TCP(ulp)->th_dport; 1436 src_port = TCP(ulp)->th_sport; 1437 /* save flags for dynamic rules */ 1438 args->f_id._flags = TCP(ulp)->th_flags; 1439 break; 1440 1441 case IPPROTO_SCTP: 1442 if (pktlen >= hlen + sizeof(struct sctphdr) + 1443 sizeof(struct sctp_chunkhdr) + 1444 offsetof(struct sctp_init, a_rwnd)) 1445 PULLUP_LEN(hlen, ulp, 1446 sizeof(struct sctphdr) + 1447 sizeof(struct sctp_chunkhdr) + 1448 offsetof(struct sctp_init, a_rwnd)); 1449 else if (pktlen >= hlen + sizeof(struct sctphdr)) 1450 PULLUP_LEN(hlen, ulp, pktlen - hlen); 1451 else 1452 PULLUP_LEN(hlen, ulp, 1453 sizeof(struct sctphdr)); 1454 src_port = SCTP(ulp)->src_port; 1455 dst_port = SCTP(ulp)->dest_port; 1456 break; 1457 1458 case IPPROTO_UDP: 1459 PULLUP_TO(hlen, ulp, struct udphdr); 1460 dst_port = UDP(ulp)->uh_dport; 1461 src_port = UDP(ulp)->uh_sport; 1462 break; 1463 1464 case IPPROTO_HOPOPTS: /* RFC 2460 */ 1465 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1466 ext_hd |= EXT_HOPOPTS; 1467 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1468 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1469 ulp = NULL; 1470 break; 1471 1472 case IPPROTO_ROUTING: /* RFC 2460 */ 1473 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 1474 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 1475 case 0: 1476 ext_hd |= EXT_RTHDR0; 1477 break; 1478 case 2: 1479 ext_hd |= EXT_RTHDR2; 1480 break; 1481 default: 1482 if (V_fw_verbose) 1483 printf("IPFW2: IPV6 - Unknown " 1484 "Routing Header type(%d)\n", 1485 ((struct ip6_rthdr *) 1486 ulp)->ip6r_type); 1487 if (V_fw_deny_unknown_exthdrs) 1488 return (IP_FW_DENY); 1489 break; 1490 } 1491 ext_hd |= EXT_ROUTING; 1492 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 1493 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 1494 ulp = NULL; 1495 break; 1496 1497 case IPPROTO_FRAGMENT: /* RFC 2460 */ 1498 PULLUP_TO(hlen, ulp, struct ip6_frag); 1499 ext_hd |= EXT_FRAGMENT; 1500 hlen += sizeof (struct ip6_frag); 1501 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 1502 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 1503 IP6F_OFF_MASK; 1504 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg & 1505 IP6F_MORE_FRAG; 1506 if (V_fw_permit_single_frag6 == 0 && 1507 offset == 0 && ip6f_mf == 0) { 1508 if (V_fw_verbose) 1509 printf("IPFW2: IPV6 - Invalid " 1510 "Fragment Header\n"); 1511 if (V_fw_deny_unknown_exthdrs) 1512 return (IP_FW_DENY); 1513 break; 1514 } 1515 args->f_id.extra = 1516 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 1517 ulp = NULL; 1518 break; 1519 1520 case IPPROTO_DSTOPTS: /* RFC 2460 */ 1521 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1522 ext_hd |= EXT_DSTOPTS; 1523 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1524 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1525 ulp = NULL; 1526 break; 1527 1528 case IPPROTO_AH: /* RFC 2402 */ 1529 PULLUP_TO(hlen, ulp, struct ip6_ext); 1530 ext_hd |= EXT_AH; 1531 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 1532 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 1533 ulp = NULL; 1534 break; 1535 1536 case IPPROTO_ESP: /* RFC 2406 */ 1537 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 1538 /* Anything past Seq# is variable length and 1539 * data past this ext. header is encrypted. */ 1540 ext_hd |= EXT_ESP; 1541 break; 1542 1543 case IPPROTO_NONE: /* RFC 2460 */ 1544 /* 1545 * Packet ends here, and IPv6 header has 1546 * already been pulled up. If ip6e_len!=0 1547 * then octets must be ignored. 1548 */ 1549 ulp = ip; /* non-NULL to get out of loop. */ 1550 break; 1551 1552 case IPPROTO_OSPFIGP: 1553 /* XXX OSPF header check? */ 1554 PULLUP_TO(hlen, ulp, struct ip6_ext); 1555 break; 1556 1557 case IPPROTO_PIM: 1558 /* XXX PIM header check? */ 1559 PULLUP_TO(hlen, ulp, struct pim); 1560 break; 1561 1562 case IPPROTO_GRE: /* RFC 1701 */ 1563 /* XXX GRE header check? */ 1564 PULLUP_TO(hlen, ulp, struct grehdr); 1565 break; 1566 1567 case IPPROTO_CARP: 1568 PULLUP_TO(hlen, ulp, struct carp_header); 1569 if (((struct carp_header *)ulp)->carp_version != 1570 CARP_VERSION) 1571 return (IP_FW_DENY); 1572 if (((struct carp_header *)ulp)->carp_type != 1573 CARP_ADVERTISEMENT) 1574 return (IP_FW_DENY); 1575 break; 1576 1577 case IPPROTO_IPV6: /* RFC 2893 */ 1578 PULLUP_TO(hlen, ulp, struct ip6_hdr); 1579 break; 1580 1581 case IPPROTO_IPV4: /* RFC 2893 */ 1582 PULLUP_TO(hlen, ulp, struct ip); 1583 break; 1584 1585 default: 1586 if (V_fw_verbose) 1587 printf("IPFW2: IPV6 - Unknown " 1588 "Extension Header(%d), ext_hd=%x\n", 1589 proto, ext_hd); 1590 if (V_fw_deny_unknown_exthdrs) 1591 return (IP_FW_DENY); 1592 PULLUP_TO(hlen, ulp, struct ip6_ext); 1593 break; 1594 } /*switch */ 1595 } 1596 ip = mtod(m, struct ip *); 1597 ip6 = (struct ip6_hdr *)ip; 1598 args->f_id.src_ip6 = ip6->ip6_src; 1599 args->f_id.dst_ip6 = ip6->ip6_dst; 1600 args->f_id.src_ip = 0; 1601 args->f_id.dst_ip = 0; 1602 args->f_id.flow_id6 = ntohl(ip6->ip6_flow); 1603 iplen = ntohs(ip6->ip6_plen) + sizeof(*ip6); 1604 } else if (pktlen >= sizeof(struct ip) && 1605 (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) { 1606 is_ipv4 = 1; 1607 hlen = ip->ip_hl << 2; 1608 args->f_id.addr_type = 4; 1609 1610 /* 1611 * Collect parameters into local variables for faster matching. 1612 */ 1613 proto = ip->ip_p; 1614 src_ip = ip->ip_src; 1615 dst_ip = ip->ip_dst; 1616 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1617 iplen = ntohs(ip->ip_len); 1618 1619 if (offset == 0) { 1620 switch (proto) { 1621 case IPPROTO_TCP: 1622 PULLUP_TO(hlen, ulp, struct tcphdr); 1623 dst_port = TCP(ulp)->th_dport; 1624 src_port = TCP(ulp)->th_sport; 1625 /* save flags for dynamic rules */ 1626 args->f_id._flags = TCP(ulp)->th_flags; 1627 break; 1628 1629 case IPPROTO_SCTP: 1630 if (pktlen >= hlen + sizeof(struct sctphdr) + 1631 sizeof(struct sctp_chunkhdr) + 1632 offsetof(struct sctp_init, a_rwnd)) 1633 PULLUP_LEN(hlen, ulp, 1634 sizeof(struct sctphdr) + 1635 sizeof(struct sctp_chunkhdr) + 1636 offsetof(struct sctp_init, a_rwnd)); 1637 else if (pktlen >= hlen + sizeof(struct sctphdr)) 1638 PULLUP_LEN(hlen, ulp, pktlen - hlen); 1639 else 1640 PULLUP_LEN(hlen, ulp, 1641 sizeof(struct sctphdr)); 1642 src_port = SCTP(ulp)->src_port; 1643 dst_port = SCTP(ulp)->dest_port; 1644 break; 1645 1646 case IPPROTO_UDP: 1647 PULLUP_TO(hlen, ulp, struct udphdr); 1648 dst_port = UDP(ulp)->uh_dport; 1649 src_port = UDP(ulp)->uh_sport; 1650 break; 1651 1652 case IPPROTO_ICMP: 1653 PULLUP_TO(hlen, ulp, struct icmphdr); 1654 //args->f_id.flags = ICMP(ulp)->icmp_type; 1655 break; 1656 1657 default: 1658 break; 1659 } 1660 } 1661 1662 ip = mtod(m, struct ip *); 1663 args->f_id.src_ip = ntohl(src_ip.s_addr); 1664 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1665 } 1666 #undef PULLUP_TO 1667 pktlen = iplen < pktlen ? iplen: pktlen; 1668 if (proto) { /* we may have port numbers, store them */ 1669 args->f_id.proto = proto; 1670 args->f_id.src_port = src_port = ntohs(src_port); 1671 args->f_id.dst_port = dst_port = ntohs(dst_port); 1672 } 1673 1674 IPFW_PF_RLOCK(chain); 1675 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ 1676 IPFW_PF_RUNLOCK(chain); 1677 return (IP_FW_PASS); /* accept */ 1678 } 1679 if (args->rule.slot) { 1680 /* 1681 * Packet has already been tagged as a result of a previous 1682 * match on rule args->rule aka args->rule_id (PIPE, QUEUE, 1683 * REASS, NETGRAPH, DIVERT/TEE...) 1684 * Validate the slot and continue from the next one 1685 * if still present, otherwise do a lookup. 1686 */ 1687 f_pos = (args->rule.chain_id == chain->id) ? 1688 args->rule.slot : 1689 ipfw_find_rule(chain, args->rule.rulenum, 1690 args->rule.rule_id); 1691 } else { 1692 f_pos = 0; 1693 } 1694 1695 /* 1696 * Now scan the rules, and parse microinstructions for each rule. 1697 * We have two nested loops and an inner switch. Sometimes we 1698 * need to break out of one or both loops, or re-enter one of 1699 * the loops with updated variables. Loop variables are: 1700 * 1701 * f_pos (outer loop) points to the current rule. 1702 * On output it points to the matching rule. 1703 * done (outer loop) is used as a flag to break the loop. 1704 * l (inner loop) residual length of current rule. 1705 * cmd points to the current microinstruction. 1706 * 1707 * We break the inner loop by setting l=0 and possibly 1708 * cmdlen=0 if we don't want to advance cmd. 1709 * We break the outer loop by setting done=1 1710 * We can restart the inner loop by setting l>0 and f_pos, f, cmd 1711 * as needed. 1712 */ 1713 for (; f_pos < chain->n_rules; f_pos++) { 1714 ipfw_insn *cmd; 1715 uint32_t tablearg = 0; 1716 int l, cmdlen, skip_or; /* skip rest of OR block */ 1717 struct ip_fw *f; 1718 1719 f = chain->map[f_pos]; 1720 if (V_set_disable & (1 << f->set) ) 1721 continue; 1722 1723 skip_or = 0; 1724 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 1725 l -= cmdlen, cmd += cmdlen) { 1726 int match; 1727 1728 /* 1729 * check_body is a jump target used when we find a 1730 * CHECK_STATE, and need to jump to the body of 1731 * the target rule. 1732 */ 1733 1734 /* check_body: */ 1735 cmdlen = F_LEN(cmd); 1736 /* 1737 * An OR block (insn_1 || .. || insn_n) has the 1738 * F_OR bit set in all but the last instruction. 1739 * The first match will set "skip_or", and cause 1740 * the following instructions to be skipped until 1741 * past the one with the F_OR bit clear. 1742 */ 1743 if (skip_or) { /* skip this instruction */ 1744 if ((cmd->len & F_OR) == 0) 1745 skip_or = 0; /* next one is good */ 1746 continue; 1747 } 1748 match = 0; /* set to 1 if we succeed */ 1749 1750 switch (cmd->opcode) { 1751 /* 1752 * The first set of opcodes compares the packet's 1753 * fields with some pattern, setting 'match' if a 1754 * match is found. At the end of the loop there is 1755 * logic to deal with F_NOT and F_OR flags associated 1756 * with the opcode. 1757 */ 1758 case O_NOP: 1759 match = 1; 1760 break; 1761 1762 case O_FORWARD_MAC: 1763 printf("ipfw: opcode %d unimplemented\n", 1764 cmd->opcode); 1765 break; 1766 1767 case O_GID: 1768 case O_UID: 1769 case O_JAIL: 1770 /* 1771 * We only check offset == 0 && proto != 0, 1772 * as this ensures that we have a 1773 * packet with the ports info. 1774 */ 1775 if (offset != 0) 1776 break; 1777 if (proto == IPPROTO_TCP || 1778 proto == IPPROTO_UDP) 1779 match = check_uidgid( 1780 (ipfw_insn_u32 *)cmd, 1781 args, &ucred_lookup, 1782 #ifdef __FreeBSD__ 1783 &ucred_cache); 1784 #else 1785 (void *)&ucred_cache); 1786 #endif 1787 break; 1788 1789 case O_RECV: 1790 match = iface_match(m->m_pkthdr.rcvif, 1791 (ipfw_insn_if *)cmd, chain, &tablearg); 1792 break; 1793 1794 case O_XMIT: 1795 match = iface_match(oif, (ipfw_insn_if *)cmd, 1796 chain, &tablearg); 1797 break; 1798 1799 case O_VIA: 1800 match = iface_match(oif ? oif : 1801 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd, 1802 chain, &tablearg); 1803 break; 1804 1805 case O_MACADDR2: 1806 if (args->eh != NULL) { /* have MAC header */ 1807 u_int32_t *want = (u_int32_t *) 1808 ((ipfw_insn_mac *)cmd)->addr; 1809 u_int32_t *mask = (u_int32_t *) 1810 ((ipfw_insn_mac *)cmd)->mask; 1811 u_int32_t *hdr = (u_int32_t *)args->eh; 1812 1813 match = 1814 ( want[0] == (hdr[0] & mask[0]) && 1815 want[1] == (hdr[1] & mask[1]) && 1816 want[2] == (hdr[2] & mask[2]) ); 1817 } 1818 break; 1819 1820 case O_MAC_TYPE: 1821 if (args->eh != NULL) { 1822 u_int16_t *p = 1823 ((ipfw_insn_u16 *)cmd)->ports; 1824 int i; 1825 1826 for (i = cmdlen - 1; !match && i>0; 1827 i--, p += 2) 1828 match = (etype >= p[0] && 1829 etype <= p[1]); 1830 } 1831 break; 1832 1833 case O_FRAG: 1834 match = (offset != 0); 1835 break; 1836 1837 case O_IN: /* "out" is "not in" */ 1838 match = (oif == NULL); 1839 break; 1840 1841 case O_LAYER2: 1842 match = (args->eh != NULL); 1843 break; 1844 1845 case O_DIVERTED: 1846 { 1847 /* For diverted packets, args->rule.info 1848 * contains the divert port (in host format) 1849 * reason and direction. 1850 */ 1851 uint32_t i = args->rule.info; 1852 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT && 1853 cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2); 1854 } 1855 break; 1856 1857 case O_PROTO: 1858 /* 1859 * We do not allow an arg of 0 so the 1860 * check of "proto" only suffices. 1861 */ 1862 match = (proto == cmd->arg1); 1863 break; 1864 1865 case O_IP_SRC: 1866 match = is_ipv4 && 1867 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1868 src_ip.s_addr); 1869 break; 1870 1871 case O_IP_DST_LOOKUP: 1872 { 1873 void *pkey; 1874 uint32_t vidx, key; 1875 uint16_t keylen; 1876 1877 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { 1878 /* Determine lookup key type */ 1879 vidx = ((ipfw_insn_u32 *)cmd)->d[1]; 1880 if (vidx != 4 /* uid */ && 1881 vidx != 5 /* jail */ && 1882 is_ipv6 == 0 && is_ipv4 == 0) 1883 break; 1884 /* Determine key length */ 1885 if (vidx == 0 /* dst-ip */ || 1886 vidx == 1 /* src-ip */) 1887 keylen = is_ipv6 ? 1888 sizeof(struct in6_addr): 1889 sizeof(in_addr_t); 1890 else { 1891 keylen = sizeof(key); 1892 pkey = &key; 1893 } 1894 if (vidx == 0 /* dst-ip */) 1895 pkey = is_ipv4 ? (void *)&dst_ip: 1896 (void *)&args->f_id.dst_ip6; 1897 else if (vidx == 1 /* src-ip */) 1898 pkey = is_ipv4 ? (void *)&src_ip: 1899 (void *)&args->f_id.src_ip6; 1900 else if (vidx == 6 /* dscp */) { 1901 if (is_ipv4) 1902 key = ip->ip_tos >> 2; 1903 else { 1904 key = args->f_id.flow_id6; 1905 key = (key & 0x0f) << 2 | 1906 (key & 0xf000) >> 14; 1907 } 1908 key &= 0x3f; 1909 } else if (vidx == 2 /* dst-port */ || 1910 vidx == 3 /* src-port */) { 1911 /* Skip fragments */ 1912 if (offset != 0) 1913 break; 1914 /* Skip proto without ports */ 1915 if (proto != IPPROTO_TCP && 1916 proto != IPPROTO_UDP && 1917 proto != IPPROTO_SCTP) 1918 break; 1919 if (vidx == 2 /* dst-port */) 1920 key = dst_port; 1921 else 1922 key = src_port; 1923 } 1924 #ifndef USERSPACE 1925 else if (vidx == 4 /* uid */ || 1926 vidx == 5 /* jail */) { 1927 check_uidgid( 1928 (ipfw_insn_u32 *)cmd, 1929 args, &ucred_lookup, 1930 #ifdef __FreeBSD__ 1931 &ucred_cache); 1932 if (vidx == 4 /* uid */) 1933 key = ucred_cache->cr_uid; 1934 else if (vidx == 5 /* jail */) 1935 key = ucred_cache->cr_prison->pr_id; 1936 #else /* !__FreeBSD__ */ 1937 (void *)&ucred_cache); 1938 if (vidx == 4 /* uid */) 1939 key = ucred_cache.uid; 1940 else if (vidx == 5 /* jail */) 1941 key = ucred_cache.xid; 1942 #endif /* !__FreeBSD__ */ 1943 } 1944 #endif /* !USERSPACE */ 1945 else 1946 break; 1947 match = ipfw_lookup_table(chain, 1948 cmd->arg1, keylen, pkey, &vidx); 1949 if (!match) 1950 break; 1951 tablearg = vidx; 1952 break; 1953 } 1954 /* cmdlen =< F_INSN_SIZE(ipfw_insn_u32) */ 1955 /* FALLTHROUGH */ 1956 } 1957 case O_IP_SRC_LOOKUP: 1958 { 1959 void *pkey; 1960 uint32_t vidx; 1961 uint16_t keylen; 1962 1963 if (is_ipv4) { 1964 keylen = sizeof(in_addr_t); 1965 if (cmd->opcode == O_IP_DST_LOOKUP) 1966 pkey = &dst_ip; 1967 else 1968 pkey = &src_ip; 1969 } else if (is_ipv6) { 1970 keylen = sizeof(struct in6_addr); 1971 if (cmd->opcode == O_IP_DST_LOOKUP) 1972 pkey = &args->f_id.dst_ip6; 1973 else 1974 pkey = &args->f_id.src_ip6; 1975 } else 1976 break; 1977 match = ipfw_lookup_table(chain, cmd->arg1, 1978 keylen, pkey, &vidx); 1979 if (!match) 1980 break; 1981 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) { 1982 match = ((ipfw_insn_u32 *)cmd)->d[0] == 1983 TARG_VAL(chain, vidx, tag); 1984 if (!match) 1985 break; 1986 } 1987 tablearg = vidx; 1988 break; 1989 } 1990 1991 case O_IP_FLOW_LOOKUP: 1992 { 1993 uint32_t v = 0; 1994 match = ipfw_lookup_table(chain, 1995 cmd->arg1, 0, &args->f_id, &v); 1996 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1997 match = ((ipfw_insn_u32 *)cmd)->d[0] == 1998 TARG_VAL(chain, v, tag); 1999 if (match) 2000 tablearg = v; 2001 } 2002 break; 2003 case O_IP_SRC_MASK: 2004 case O_IP_DST_MASK: 2005 if (is_ipv4) { 2006 uint32_t a = 2007 (cmd->opcode == O_IP_DST_MASK) ? 2008 dst_ip.s_addr : src_ip.s_addr; 2009 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 2010 int i = cmdlen-1; 2011 2012 for (; !match && i>0; i-= 2, p+= 2) 2013 match = (p[0] == (a & p[1])); 2014 } 2015 break; 2016 2017 case O_IP_SRC_ME: 2018 if (is_ipv4) { 2019 match = in_localip(src_ip); 2020 break; 2021 } 2022 #ifdef INET6 2023 /* FALLTHROUGH */ 2024 case O_IP6_SRC_ME: 2025 match= is_ipv6 && ipfw_localip6(&args->f_id.src_ip6); 2026 #endif 2027 break; 2028 2029 case O_IP_DST_SET: 2030 case O_IP_SRC_SET: 2031 if (is_ipv4) { 2032 u_int32_t *d = (u_int32_t *)(cmd+1); 2033 u_int32_t addr = 2034 cmd->opcode == O_IP_DST_SET ? 2035 args->f_id.dst_ip : 2036 args->f_id.src_ip; 2037 2038 if (addr < d[0]) 2039 break; 2040 addr -= d[0]; /* subtract base */ 2041 match = (addr < cmd->arg1) && 2042 ( d[ 1 + (addr>>5)] & 2043 (1<<(addr & 0x1f)) ); 2044 } 2045 break; 2046 2047 case O_IP_DST: 2048 match = is_ipv4 && 2049 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2050 dst_ip.s_addr); 2051 break; 2052 2053 case O_IP_DST_ME: 2054 if (is_ipv4) { 2055 match = in_localip(dst_ip); 2056 break; 2057 } 2058 #ifdef INET6 2059 /* FALLTHROUGH */ 2060 case O_IP6_DST_ME: 2061 match= is_ipv6 && ipfw_localip6(&args->f_id.dst_ip6); 2062 #endif 2063 break; 2064 2065 2066 case O_IP_SRCPORT: 2067 case O_IP_DSTPORT: 2068 /* 2069 * offset == 0 && proto != 0 is enough 2070 * to guarantee that we have a 2071 * packet with port info. 2072 */ 2073 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP || 2074 proto==IPPROTO_SCTP) && offset == 0) { 2075 u_int16_t x = 2076 (cmd->opcode == O_IP_SRCPORT) ? 2077 src_port : dst_port ; 2078 u_int16_t *p = 2079 ((ipfw_insn_u16 *)cmd)->ports; 2080 int i; 2081 2082 for (i = cmdlen - 1; !match && i>0; 2083 i--, p += 2) 2084 match = (x>=p[0] && x<=p[1]); 2085 } 2086 break; 2087 2088 case O_ICMPTYPE: 2089 match = (offset == 0 && proto==IPPROTO_ICMP && 2090 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 2091 break; 2092 2093 #ifdef INET6 2094 case O_ICMP6TYPE: 2095 match = is_ipv6 && offset == 0 && 2096 proto==IPPROTO_ICMPV6 && 2097 icmp6type_match( 2098 ICMP6(ulp)->icmp6_type, 2099 (ipfw_insn_u32 *)cmd); 2100 break; 2101 #endif /* INET6 */ 2102 2103 case O_IPOPT: 2104 match = (is_ipv4 && 2105 ipopts_match(ip, cmd) ); 2106 break; 2107 2108 case O_IPVER: 2109 match = (is_ipv4 && 2110 cmd->arg1 == ip->ip_v); 2111 break; 2112 2113 case O_IPID: 2114 case O_IPLEN: 2115 case O_IPTTL: 2116 if (is_ipv4) { /* only for IP packets */ 2117 uint16_t x; 2118 uint16_t *p; 2119 int i; 2120 2121 if (cmd->opcode == O_IPLEN) 2122 x = iplen; 2123 else if (cmd->opcode == O_IPTTL) 2124 x = ip->ip_ttl; 2125 else /* must be IPID */ 2126 x = ntohs(ip->ip_id); 2127 if (cmdlen == 1) { 2128 match = (cmd->arg1 == x); 2129 break; 2130 } 2131 /* otherwise we have ranges */ 2132 p = ((ipfw_insn_u16 *)cmd)->ports; 2133 i = cmdlen - 1; 2134 for (; !match && i>0; i--, p += 2) 2135 match = (x >= p[0] && x <= p[1]); 2136 } 2137 break; 2138 2139 case O_IPPRECEDENCE: 2140 match = (is_ipv4 && 2141 (cmd->arg1 == (ip->ip_tos & 0xe0)) ); 2142 break; 2143 2144 case O_IPTOS: 2145 match = (is_ipv4 && 2146 flags_match(cmd, ip->ip_tos)); 2147 break; 2148 2149 case O_DSCP: 2150 { 2151 uint32_t *p; 2152 uint16_t x; 2153 2154 p = ((ipfw_insn_u32 *)cmd)->d; 2155 2156 if (is_ipv4) 2157 x = ip->ip_tos >> 2; 2158 else if (is_ipv6) { 2159 uint8_t *v; 2160 v = &((struct ip6_hdr *)ip)->ip6_vfc; 2161 x = (*v & 0x0F) << 2; 2162 v++; 2163 x |= *v >> 6; 2164 } else 2165 break; 2166 2167 /* DSCP bitmask is stored as low_u32 high_u32 */ 2168 if (x >= 32) 2169 match = *(p + 1) & (1 << (x - 32)); 2170 else 2171 match = *p & (1 << x); 2172 } 2173 break; 2174 2175 case O_TCPDATALEN: 2176 if (proto == IPPROTO_TCP && offset == 0) { 2177 struct tcphdr *tcp; 2178 uint16_t x; 2179 uint16_t *p; 2180 int i; 2181 #ifdef INET6 2182 if (is_ipv6) { 2183 struct ip6_hdr *ip6; 2184 2185 ip6 = (struct ip6_hdr *)ip; 2186 if (ip6->ip6_plen == 0) { 2187 /* 2188 * Jumbo payload is not 2189 * supported by this 2190 * opcode. 2191 */ 2192 break; 2193 } 2194 x = iplen - hlen; 2195 } else 2196 #endif /* INET6 */ 2197 x = iplen - (ip->ip_hl << 2); 2198 tcp = TCP(ulp); 2199 x -= tcp->th_off << 2; 2200 if (cmdlen == 1) { 2201 match = (cmd->arg1 == x); 2202 break; 2203 } 2204 /* otherwise we have ranges */ 2205 p = ((ipfw_insn_u16 *)cmd)->ports; 2206 i = cmdlen - 1; 2207 for (; !match && i>0; i--, p += 2) 2208 match = (x >= p[0] && x <= p[1]); 2209 } 2210 break; 2211 2212 case O_TCPFLAGS: 2213 match = (proto == IPPROTO_TCP && offset == 0 && 2214 flags_match(cmd, TCP(ulp)->th_flags)); 2215 break; 2216 2217 case O_TCPOPTS: 2218 if (proto == IPPROTO_TCP && offset == 0 && ulp){ 2219 PULLUP_LEN(hlen, ulp, 2220 (TCP(ulp)->th_off << 2)); 2221 match = tcpopts_match(TCP(ulp), cmd); 2222 } 2223 break; 2224 2225 case O_TCPSEQ: 2226 match = (proto == IPPROTO_TCP && offset == 0 && 2227 ((ipfw_insn_u32 *)cmd)->d[0] == 2228 TCP(ulp)->th_seq); 2229 break; 2230 2231 case O_TCPACK: 2232 match = (proto == IPPROTO_TCP && offset == 0 && 2233 ((ipfw_insn_u32 *)cmd)->d[0] == 2234 TCP(ulp)->th_ack); 2235 break; 2236 2237 case O_TCPWIN: 2238 if (proto == IPPROTO_TCP && offset == 0) { 2239 uint16_t x; 2240 uint16_t *p; 2241 int i; 2242 2243 x = ntohs(TCP(ulp)->th_win); 2244 if (cmdlen == 1) { 2245 match = (cmd->arg1 == x); 2246 break; 2247 } 2248 /* Otherwise we have ranges. */ 2249 p = ((ipfw_insn_u16 *)cmd)->ports; 2250 i = cmdlen - 1; 2251 for (; !match && i > 0; i--, p += 2) 2252 match = (x >= p[0] && x <= p[1]); 2253 } 2254 break; 2255 2256 case O_ESTAB: 2257 /* reject packets which have SYN only */ 2258 /* XXX should i also check for TH_ACK ? */ 2259 match = (proto == IPPROTO_TCP && offset == 0 && 2260 (TCP(ulp)->th_flags & 2261 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 2262 break; 2263 2264 case O_ALTQ: { 2265 struct pf_mtag *at; 2266 struct m_tag *mtag; 2267 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 2268 2269 /* 2270 * ALTQ uses mbuf tags from another 2271 * packet filtering system - pf(4). 2272 * We allocate a tag in its format 2273 * and fill it in, pretending to be pf(4). 2274 */ 2275 match = 1; 2276 at = pf_find_mtag(m); 2277 if (at != NULL && at->qid != 0) 2278 break; 2279 mtag = m_tag_get(PACKET_TAG_PF, 2280 sizeof(struct pf_mtag), M_NOWAIT | M_ZERO); 2281 if (mtag == NULL) { 2282 /* 2283 * Let the packet fall back to the 2284 * default ALTQ. 2285 */ 2286 break; 2287 } 2288 m_tag_prepend(m, mtag); 2289 at = (struct pf_mtag *)(mtag + 1); 2290 at->qid = altq->qid; 2291 at->hdr = ip; 2292 break; 2293 } 2294 2295 case O_LOG: 2296 ipfw_log(chain, f, hlen, args, m, 2297 oif, offset | ip6f_mf, tablearg, ip); 2298 match = 1; 2299 break; 2300 2301 case O_PROB: 2302 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 2303 break; 2304 2305 case O_VERREVPATH: 2306 /* Outgoing packets automatically pass/match */ 2307 match = ((oif != NULL) || 2308 (m->m_pkthdr.rcvif == NULL) || 2309 ( 2310 #ifdef INET6 2311 is_ipv6 ? 2312 verify_path6(&(args->f_id.src_ip6), 2313 m->m_pkthdr.rcvif, args->f_id.fib) : 2314 #endif 2315 verify_path(src_ip, m->m_pkthdr.rcvif, 2316 args->f_id.fib))); 2317 break; 2318 2319 case O_VERSRCREACH: 2320 /* Outgoing packets automatically pass/match */ 2321 match = (hlen > 0 && ((oif != NULL) || 2322 #ifdef INET6 2323 is_ipv6 ? 2324 verify_path6(&(args->f_id.src_ip6), 2325 NULL, args->f_id.fib) : 2326 #endif 2327 verify_path(src_ip, NULL, args->f_id.fib))); 2328 break; 2329 2330 case O_ANTISPOOF: 2331 /* Outgoing packets automatically pass/match */ 2332 if (oif == NULL && hlen > 0 && 2333 ( (is_ipv4 && in_localaddr(src_ip)) 2334 #ifdef INET6 2335 || (is_ipv6 && 2336 in6_localaddr(&(args->f_id.src_ip6))) 2337 #endif 2338 )) 2339 match = 2340 #ifdef INET6 2341 is_ipv6 ? verify_path6( 2342 &(args->f_id.src_ip6), 2343 m->m_pkthdr.rcvif, 2344 args->f_id.fib) : 2345 #endif 2346 verify_path(src_ip, 2347 m->m_pkthdr.rcvif, 2348 args->f_id.fib); 2349 else 2350 match = 1; 2351 break; 2352 2353 case O_IPSEC: 2354 match = (m_tag_find(m, 2355 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 2356 /* otherwise no match */ 2357 break; 2358 2359 #ifdef INET6 2360 case O_IP6_SRC: 2361 match = is_ipv6 && 2362 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 2363 &((ipfw_insn_ip6 *)cmd)->addr6); 2364 break; 2365 2366 case O_IP6_DST: 2367 match = is_ipv6 && 2368 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 2369 &((ipfw_insn_ip6 *)cmd)->addr6); 2370 break; 2371 case O_IP6_SRC_MASK: 2372 case O_IP6_DST_MASK: 2373 if (is_ipv6) { 2374 int i = cmdlen - 1; 2375 struct in6_addr p; 2376 struct in6_addr *d = 2377 &((ipfw_insn_ip6 *)cmd)->addr6; 2378 2379 for (; !match && i > 0; d += 2, 2380 i -= F_INSN_SIZE(struct in6_addr) 2381 * 2) { 2382 p = (cmd->opcode == 2383 O_IP6_SRC_MASK) ? 2384 args->f_id.src_ip6: 2385 args->f_id.dst_ip6; 2386 APPLY_MASK(&p, &d[1]); 2387 match = 2388 IN6_ARE_ADDR_EQUAL(&d[0], 2389 &p); 2390 } 2391 } 2392 break; 2393 2394 case O_FLOW6ID: 2395 match = is_ipv6 && 2396 flow6id_match(args->f_id.flow_id6, 2397 (ipfw_insn_u32 *) cmd); 2398 break; 2399 2400 case O_EXT_HDR: 2401 match = is_ipv6 && 2402 (ext_hd & ((ipfw_insn *) cmd)->arg1); 2403 break; 2404 2405 case O_IP6: 2406 match = is_ipv6; 2407 break; 2408 #endif 2409 2410 case O_IP4: 2411 match = is_ipv4; 2412 break; 2413 2414 case O_TAG: { 2415 struct m_tag *mtag; 2416 uint32_t tag = TARG(cmd->arg1, tag); 2417 2418 /* Packet is already tagged with this tag? */ 2419 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 2420 2421 /* We have `untag' action when F_NOT flag is 2422 * present. And we must remove this mtag from 2423 * mbuf and reset `match' to zero (`match' will 2424 * be inversed later). 2425 * Otherwise we should allocate new mtag and 2426 * push it into mbuf. 2427 */ 2428 if (cmd->len & F_NOT) { /* `untag' action */ 2429 if (mtag != NULL) 2430 m_tag_delete(m, mtag); 2431 match = 0; 2432 } else { 2433 if (mtag == NULL) { 2434 mtag = m_tag_alloc( MTAG_IPFW, 2435 tag, 0, M_NOWAIT); 2436 if (mtag != NULL) 2437 m_tag_prepend(m, mtag); 2438 } 2439 match = 1; 2440 } 2441 break; 2442 } 2443 2444 case O_FIB: /* try match the specified fib */ 2445 if (args->f_id.fib == cmd->arg1) 2446 match = 1; 2447 break; 2448 2449 case O_SOCKARG: { 2450 #ifndef USERSPACE /* not supported in userspace */ 2451 struct inpcb *inp = args->inp; 2452 struct inpcbinfo *pi; 2453 2454 if (is_ipv6) /* XXX can we remove this ? */ 2455 break; 2456 2457 if (proto == IPPROTO_TCP) 2458 pi = &V_tcbinfo; 2459 else if (proto == IPPROTO_UDP) 2460 pi = &V_udbinfo; 2461 else 2462 break; 2463 2464 /* 2465 * XXXRW: so_user_cookie should almost 2466 * certainly be inp_user_cookie? 2467 */ 2468 2469 /* For incoming packet, lookup up the 2470 inpcb using the src/dest ip/port tuple */ 2471 if (inp == NULL) { 2472 inp = in_pcblookup(pi, 2473 src_ip, htons(src_port), 2474 dst_ip, htons(dst_port), 2475 INPLOOKUP_RLOCKPCB, NULL); 2476 if (inp != NULL) { 2477 tablearg = 2478 inp->inp_socket->so_user_cookie; 2479 if (tablearg) 2480 match = 1; 2481 INP_RUNLOCK(inp); 2482 } 2483 } else { 2484 if (inp->inp_socket) { 2485 tablearg = 2486 inp->inp_socket->so_user_cookie; 2487 if (tablearg) 2488 match = 1; 2489 } 2490 } 2491 #endif /* !USERSPACE */ 2492 break; 2493 } 2494 2495 case O_TAGGED: { 2496 struct m_tag *mtag; 2497 uint32_t tag = TARG(cmd->arg1, tag); 2498 2499 if (cmdlen == 1) { 2500 match = m_tag_locate(m, MTAG_IPFW, 2501 tag, NULL) != NULL; 2502 break; 2503 } 2504 2505 /* we have ranges */ 2506 for (mtag = m_tag_first(m); 2507 mtag != NULL && !match; 2508 mtag = m_tag_next(m, mtag)) { 2509 uint16_t *p; 2510 int i; 2511 2512 if (mtag->m_tag_cookie != MTAG_IPFW) 2513 continue; 2514 2515 p = ((ipfw_insn_u16 *)cmd)->ports; 2516 i = cmdlen - 1; 2517 for(; !match && i > 0; i--, p += 2) 2518 match = 2519 mtag->m_tag_id >= p[0] && 2520 mtag->m_tag_id <= p[1]; 2521 } 2522 break; 2523 } 2524 2525 /* 2526 * The second set of opcodes represents 'actions', 2527 * i.e. the terminal part of a rule once the packet 2528 * matches all previous patterns. 2529 * Typically there is only one action for each rule, 2530 * and the opcode is stored at the end of the rule 2531 * (but there are exceptions -- see below). 2532 * 2533 * In general, here we set retval and terminate the 2534 * outer loop (would be a 'break 3' in some language, 2535 * but we need to set l=0, done=1) 2536 * 2537 * Exceptions: 2538 * O_COUNT and O_SKIPTO actions: 2539 * instead of terminating, we jump to the next rule 2540 * (setting l=0), or to the SKIPTO target (setting 2541 * f/f_len, cmd and l as needed), respectively. 2542 * 2543 * O_TAG, O_LOG and O_ALTQ action parameters: 2544 * perform some action and set match = 1; 2545 * 2546 * O_LIMIT and O_KEEP_STATE: these opcodes are 2547 * not real 'actions', and are stored right 2548 * before the 'action' part of the rule. 2549 * These opcodes try to install an entry in the 2550 * state tables; if successful, we continue with 2551 * the next opcode (match=1; break;), otherwise 2552 * the packet must be dropped (set retval, 2553 * break loops with l=0, done=1) 2554 * 2555 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2556 * cause a lookup of the state table, and a jump 2557 * to the 'action' part of the parent rule 2558 * if an entry is found, or 2559 * (CHECK_STATE only) a jump to the next rule if 2560 * the entry is not found. 2561 * The result of the lookup is cached so that 2562 * further instances of these opcodes become NOPs. 2563 * The jump to the next rule is done by setting 2564 * l=0, cmdlen=0. 2565 */ 2566 case O_LIMIT: 2567 case O_KEEP_STATE: 2568 if (ipfw_dyn_install_state(chain, f, 2569 (ipfw_insn_limit *)cmd, args, tablearg)) { 2570 /* error or limit violation */ 2571 retval = IP_FW_DENY; 2572 l = 0; /* exit inner loop */ 2573 done = 1; /* exit outer loop */ 2574 } 2575 match = 1; 2576 break; 2577 2578 case O_PROBE_STATE: 2579 case O_CHECK_STATE: 2580 /* 2581 * dynamic rules are checked at the first 2582 * keep-state or check-state occurrence, 2583 * with the result being stored in dyn_dir 2584 * and dyn_name. 2585 * The compiler introduces a PROBE_STATE 2586 * instruction for us when we have a 2587 * KEEP_STATE (because PROBE_STATE needs 2588 * to be run first). 2589 * 2590 * (dyn_dir == MATCH_UNKNOWN) means this is 2591 * first lookup for such f_id. Do lookup. 2592 * 2593 * (dyn_dir != MATCH_UNKNOWN && 2594 * dyn_name != 0 && dyn_name != cmd->arg1) 2595 * means previous lookup didn't find dynamic 2596 * rule for specific state name and current 2597 * lookup will search rule with another state 2598 * name. Redo lookup. 2599 * 2600 * (dyn_dir != MATCH_UNKNOWN && dyn_name == 0) 2601 * means previous lookup was for `any' name 2602 * and it didn't find rule. No need to do 2603 * lookup again. 2604 */ 2605 if ((dyn_dir == MATCH_UNKNOWN || 2606 (dyn_name != 0 && 2607 dyn_name != cmd->arg1)) && 2608 (q = ipfw_dyn_lookup_state(&args->f_id, 2609 ulp, pktlen, &dyn_dir, 2610 (dyn_name = cmd->arg1))) != NULL) { 2611 /* 2612 * Found dynamic entry, jump to the 2613 * 'action' part of the parent rule 2614 * by setting f, cmd, l and clearing 2615 * cmdlen. 2616 */ 2617 f = q; 2618 /* XXX we would like to have f_pos 2619 * readily accessible in the dynamic 2620 * rule, instead of having to 2621 * lookup q->rule. 2622 */ 2623 f_pos = ipfw_find_rule(chain, 2624 f->rulenum, f->id); 2625 cmd = ACTION_PTR(f); 2626 l = f->cmd_len - f->act_ofs; 2627 cmdlen = 0; 2628 match = 1; 2629 break; 2630 } 2631 /* 2632 * Dynamic entry not found. If CHECK_STATE, 2633 * skip to next rule, if PROBE_STATE just 2634 * ignore and continue with next opcode. 2635 */ 2636 if (cmd->opcode == O_CHECK_STATE) 2637 l = 0; /* exit inner loop */ 2638 match = 1; 2639 break; 2640 2641 case O_ACCEPT: 2642 retval = 0; /* accept */ 2643 l = 0; /* exit inner loop */ 2644 done = 1; /* exit outer loop */ 2645 break; 2646 2647 case O_PIPE: 2648 case O_QUEUE: 2649 set_match(args, f_pos, chain); 2650 args->rule.info = TARG(cmd->arg1, pipe); 2651 if (cmd->opcode == O_PIPE) 2652 args->rule.info |= IPFW_IS_PIPE; 2653 if (V_fw_one_pass) 2654 args->rule.info |= IPFW_ONEPASS; 2655 retval = IP_FW_DUMMYNET; 2656 l = 0; /* exit inner loop */ 2657 done = 1; /* exit outer loop */ 2658 break; 2659 2660 case O_DIVERT: 2661 case O_TEE: 2662 if (args->eh) /* not on layer 2 */ 2663 break; 2664 /* otherwise this is terminal */ 2665 l = 0; /* exit inner loop */ 2666 done = 1; /* exit outer loop */ 2667 retval = (cmd->opcode == O_DIVERT) ? 2668 IP_FW_DIVERT : IP_FW_TEE; 2669 set_match(args, f_pos, chain); 2670 args->rule.info = TARG(cmd->arg1, divert); 2671 break; 2672 2673 case O_COUNT: 2674 IPFW_INC_RULE_COUNTER(f, pktlen); 2675 l = 0; /* exit inner loop */ 2676 break; 2677 2678 case O_SKIPTO: 2679 IPFW_INC_RULE_COUNTER(f, pktlen); 2680 f_pos = JUMP(chain, f, cmd->arg1, tablearg, 0); 2681 /* 2682 * Skip disabled rules, and re-enter 2683 * the inner loop with the correct 2684 * f_pos, f, l and cmd. 2685 * Also clear cmdlen and skip_or 2686 */ 2687 for (; f_pos < chain->n_rules - 1 && 2688 (V_set_disable & 2689 (1 << chain->map[f_pos]->set)); 2690 f_pos++) 2691 ; 2692 /* Re-enter the inner loop at the skipto rule. */ 2693 f = chain->map[f_pos]; 2694 l = f->cmd_len; 2695 cmd = f->cmd; 2696 match = 1; 2697 cmdlen = 0; 2698 skip_or = 0; 2699 continue; 2700 break; /* not reached */ 2701 2702 case O_CALLRETURN: { 2703 /* 2704 * Implementation of `subroutine' call/return, 2705 * in the stack carried in an mbuf tag. This 2706 * is different from `skipto' in that any call 2707 * address is possible (`skipto' must prevent 2708 * backward jumps to avoid endless loops). 2709 * We have `return' action when F_NOT flag is 2710 * present. The `m_tag_id' field is used as 2711 * stack pointer. 2712 */ 2713 struct m_tag *mtag; 2714 uint16_t jmpto, *stack; 2715 2716 #define IS_CALL ((cmd->len & F_NOT) == 0) 2717 #define IS_RETURN ((cmd->len & F_NOT) != 0) 2718 /* 2719 * Hand-rolled version of m_tag_locate() with 2720 * wildcard `type'. 2721 * If not already tagged, allocate new tag. 2722 */ 2723 mtag = m_tag_first(m); 2724 while (mtag != NULL) { 2725 if (mtag->m_tag_cookie == 2726 MTAG_IPFW_CALL) 2727 break; 2728 mtag = m_tag_next(m, mtag); 2729 } 2730 if (mtag == NULL && IS_CALL) { 2731 mtag = m_tag_alloc(MTAG_IPFW_CALL, 0, 2732 IPFW_CALLSTACK_SIZE * 2733 sizeof(uint16_t), M_NOWAIT); 2734 if (mtag != NULL) 2735 m_tag_prepend(m, mtag); 2736 } 2737 2738 /* 2739 * On error both `call' and `return' just 2740 * continue with next rule. 2741 */ 2742 if (IS_RETURN && (mtag == NULL || 2743 mtag->m_tag_id == 0)) { 2744 l = 0; /* exit inner loop */ 2745 break; 2746 } 2747 if (IS_CALL && (mtag == NULL || 2748 mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) { 2749 printf("ipfw: call stack error, " 2750 "go to next rule\n"); 2751 l = 0; /* exit inner loop */ 2752 break; 2753 } 2754 2755 IPFW_INC_RULE_COUNTER(f, pktlen); 2756 stack = (uint16_t *)(mtag + 1); 2757 2758 /* 2759 * The `call' action may use cached f_pos 2760 * (in f->next_rule), whose version is written 2761 * in f->next_rule. 2762 * The `return' action, however, doesn't have 2763 * fixed jump address in cmd->arg1 and can't use 2764 * cache. 2765 */ 2766 if (IS_CALL) { 2767 stack[mtag->m_tag_id] = f->rulenum; 2768 mtag->m_tag_id++; 2769 f_pos = JUMP(chain, f, cmd->arg1, 2770 tablearg, 1); 2771 } else { /* `return' action */ 2772 mtag->m_tag_id--; 2773 jmpto = stack[mtag->m_tag_id] + 1; 2774 f_pos = ipfw_find_rule(chain, jmpto, 0); 2775 } 2776 2777 /* 2778 * Skip disabled rules, and re-enter 2779 * the inner loop with the correct 2780 * f_pos, f, l and cmd. 2781 * Also clear cmdlen and skip_or 2782 */ 2783 for (; f_pos < chain->n_rules - 1 && 2784 (V_set_disable & 2785 (1 << chain->map[f_pos]->set)); f_pos++) 2786 ; 2787 /* Re-enter the inner loop at the dest rule. */ 2788 f = chain->map[f_pos]; 2789 l = f->cmd_len; 2790 cmd = f->cmd; 2791 cmdlen = 0; 2792 skip_or = 0; 2793 continue; 2794 break; /* NOTREACHED */ 2795 } 2796 #undef IS_CALL 2797 #undef IS_RETURN 2798 2799 case O_REJECT: 2800 /* 2801 * Drop the packet and send a reject notice 2802 * if the packet is not ICMP (or is an ICMP 2803 * query), and it is not multicast/broadcast. 2804 */ 2805 if (hlen > 0 && is_ipv4 && offset == 0 && 2806 (proto != IPPROTO_ICMP || 2807 is_icmp_query(ICMP(ulp))) && 2808 !(m->m_flags & (M_BCAST|M_MCAST)) && 2809 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 2810 send_reject(args, cmd->arg1, iplen, ip); 2811 m = args->m; 2812 } 2813 /* FALLTHROUGH */ 2814 #ifdef INET6 2815 case O_UNREACH6: 2816 if (hlen > 0 && is_ipv6 && 2817 ((offset & IP6F_OFF_MASK) == 0) && 2818 (proto != IPPROTO_ICMPV6 || 2819 (is_icmp6_query(icmp6_type) == 1)) && 2820 !(m->m_flags & (M_BCAST|M_MCAST)) && 2821 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 2822 send_reject6( 2823 args, cmd->arg1, hlen, 2824 (struct ip6_hdr *)ip); 2825 m = args->m; 2826 } 2827 /* FALLTHROUGH */ 2828 #endif 2829 case O_DENY: 2830 retval = IP_FW_DENY; 2831 l = 0; /* exit inner loop */ 2832 done = 1; /* exit outer loop */ 2833 break; 2834 2835 case O_FORWARD_IP: 2836 if (args->eh) /* not valid on layer2 pkts */ 2837 break; 2838 if (q != f || dyn_dir == MATCH_FORWARD) { 2839 struct sockaddr_in *sa; 2840 2841 sa = &(((ipfw_insn_sa *)cmd)->sa); 2842 if (sa->sin_addr.s_addr == INADDR_ANY) { 2843 #ifdef INET6 2844 /* 2845 * We use O_FORWARD_IP opcode for 2846 * fwd rule with tablearg, but tables 2847 * now support IPv6 addresses. And 2848 * when we are inspecting IPv6 packet, 2849 * we can use nh6 field from 2850 * table_value as next_hop6 address. 2851 */ 2852 if (is_ipv6) { 2853 struct sockaddr_in6 *sa6; 2854 2855 sa6 = args->next_hop6 = 2856 &args->hopstore6; 2857 sa6->sin6_family = AF_INET6; 2858 sa6->sin6_len = sizeof(*sa6); 2859 sa6->sin6_addr = TARG_VAL( 2860 chain, tablearg, nh6); 2861 sa6->sin6_port = sa->sin_port; 2862 /* 2863 * Set sin6_scope_id only for 2864 * link-local unicast addresses. 2865 */ 2866 if (IN6_IS_ADDR_LINKLOCAL( 2867 &sa6->sin6_addr)) 2868 sa6->sin6_scope_id = 2869 TARG_VAL(chain, 2870 tablearg, 2871 zoneid); 2872 } else 2873 #endif 2874 { 2875 args->hopstore.sin_port = 2876 sa->sin_port; 2877 sa = args->next_hop = 2878 &args->hopstore; 2879 sa->sin_family = AF_INET; 2880 sa->sin_len = sizeof(*sa); 2881 sa->sin_addr.s_addr = htonl( 2882 TARG_VAL(chain, tablearg, 2883 nh4)); 2884 } 2885 } else { 2886 args->next_hop = sa; 2887 } 2888 } 2889 retval = IP_FW_PASS; 2890 l = 0; /* exit inner loop */ 2891 done = 1; /* exit outer loop */ 2892 break; 2893 2894 #ifdef INET6 2895 case O_FORWARD_IP6: 2896 if (args->eh) /* not valid on layer2 pkts */ 2897 break; 2898 if (q != f || dyn_dir == MATCH_FORWARD) { 2899 struct sockaddr_in6 *sin6; 2900 2901 sin6 = &(((ipfw_insn_sa6 *)cmd)->sa); 2902 args->next_hop6 = sin6; 2903 } 2904 retval = IP_FW_PASS; 2905 l = 0; /* exit inner loop */ 2906 done = 1; /* exit outer loop */ 2907 break; 2908 #endif 2909 2910 case O_NETGRAPH: 2911 case O_NGTEE: 2912 set_match(args, f_pos, chain); 2913 args->rule.info = TARG(cmd->arg1, netgraph); 2914 if (V_fw_one_pass) 2915 args->rule.info |= IPFW_ONEPASS; 2916 retval = (cmd->opcode == O_NETGRAPH) ? 2917 IP_FW_NETGRAPH : IP_FW_NGTEE; 2918 l = 0; /* exit inner loop */ 2919 done = 1; /* exit outer loop */ 2920 break; 2921 2922 case O_SETFIB: { 2923 uint32_t fib; 2924 2925 IPFW_INC_RULE_COUNTER(f, pktlen); 2926 fib = TARG(cmd->arg1, fib) & 0x7FFF; 2927 if (fib >= rt_numfibs) 2928 fib = 0; 2929 M_SETFIB(m, fib); 2930 args->f_id.fib = fib; 2931 l = 0; /* exit inner loop */ 2932 break; 2933 } 2934 2935 case O_SETDSCP: { 2936 uint16_t code; 2937 2938 code = TARG(cmd->arg1, dscp) & 0x3F; 2939 l = 0; /* exit inner loop */ 2940 if (is_ipv4) { 2941 uint16_t old; 2942 2943 old = *(uint16_t *)ip; 2944 ip->ip_tos = (code << 2) | 2945 (ip->ip_tos & 0x03); 2946 ip->ip_sum = cksum_adjust(ip->ip_sum, 2947 old, *(uint16_t *)ip); 2948 } else if (is_ipv6) { 2949 uint8_t *v; 2950 2951 v = &((struct ip6_hdr *)ip)->ip6_vfc; 2952 *v = (*v & 0xF0) | (code >> 2); 2953 v++; 2954 *v = (*v & 0x3F) | ((code & 0x03) << 6); 2955 } else 2956 break; 2957 2958 IPFW_INC_RULE_COUNTER(f, pktlen); 2959 break; 2960 } 2961 2962 case O_NAT: 2963 l = 0; /* exit inner loop */ 2964 done = 1; /* exit outer loop */ 2965 /* 2966 * Ensure that we do not invoke NAT handler for 2967 * non IPv4 packets. Libalias expects only IPv4. 2968 */ 2969 if (!is_ipv4 || !IPFW_NAT_LOADED) { 2970 retval = IP_FW_DENY; 2971 break; 2972 } 2973 2974 struct cfg_nat *t; 2975 int nat_id; 2976 2977 set_match(args, f_pos, chain); 2978 /* Check if this is 'global' nat rule */ 2979 if (cmd->arg1 == IP_FW_NAT44_GLOBAL) { 2980 retval = ipfw_nat_ptr(args, NULL, m); 2981 break; 2982 } 2983 t = ((ipfw_insn_nat *)cmd)->nat; 2984 if (t == NULL) { 2985 nat_id = TARG(cmd->arg1, nat); 2986 t = (*lookup_nat_ptr)(&chain->nat, nat_id); 2987 2988 if (t == NULL) { 2989 retval = IP_FW_DENY; 2990 break; 2991 } 2992 if (cmd->arg1 != IP_FW_TARG) 2993 ((ipfw_insn_nat *)cmd)->nat = t; 2994 } 2995 retval = ipfw_nat_ptr(args, t, m); 2996 break; 2997 2998 case O_REASS: { 2999 int ip_off; 3000 3001 IPFW_INC_RULE_COUNTER(f, pktlen); 3002 l = 0; /* in any case exit inner loop */ 3003 ip_off = ntohs(ip->ip_off); 3004 3005 /* if not fragmented, go to next rule */ 3006 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0) 3007 break; 3008 3009 args->m = m = ip_reass(m); 3010 3011 /* 3012 * do IP header checksum fixup. 3013 */ 3014 if (m == NULL) { /* fragment got swallowed */ 3015 retval = IP_FW_DENY; 3016 } else { /* good, packet complete */ 3017 int hlen; 3018 3019 ip = mtod(m, struct ip *); 3020 hlen = ip->ip_hl << 2; 3021 ip->ip_sum = 0; 3022 if (hlen == sizeof(struct ip)) 3023 ip->ip_sum = in_cksum_hdr(ip); 3024 else 3025 ip->ip_sum = in_cksum(m, hlen); 3026 retval = IP_FW_REASS; 3027 set_match(args, f_pos, chain); 3028 } 3029 done = 1; /* exit outer loop */ 3030 break; 3031 } 3032 case O_EXTERNAL_ACTION: 3033 l = 0; /* in any case exit inner loop */ 3034 retval = ipfw_run_eaction(chain, args, 3035 cmd, &done); 3036 /* 3037 * If both @retval and @done are zero, 3038 * consider this as rule matching and 3039 * update counters. 3040 */ 3041 if (retval == 0 && done == 0) { 3042 IPFW_INC_RULE_COUNTER(f, pktlen); 3043 /* 3044 * Reset the result of the last 3045 * dynamic state lookup. 3046 * External action can change 3047 * @args content, and it may be 3048 * used for new state lookup later. 3049 */ 3050 dyn_dir = MATCH_UNKNOWN; 3051 } 3052 break; 3053 3054 default: 3055 panic("-- unknown opcode %d\n", cmd->opcode); 3056 } /* end of switch() on opcodes */ 3057 /* 3058 * if we get here with l=0, then match is irrelevant. 3059 */ 3060 3061 if (cmd->len & F_NOT) 3062 match = !match; 3063 3064 if (match) { 3065 if (cmd->len & F_OR) 3066 skip_or = 1; 3067 } else { 3068 if (!(cmd->len & F_OR)) /* not an OR block, */ 3069 break; /* try next rule */ 3070 } 3071 3072 } /* end of inner loop, scan opcodes */ 3073 #undef PULLUP_LEN 3074 3075 if (done) 3076 break; 3077 3078 /* next_rule:; */ /* try next rule */ 3079 3080 } /* end of outer for, scan rules */ 3081 3082 if (done) { 3083 struct ip_fw *rule = chain->map[f_pos]; 3084 /* Update statistics */ 3085 IPFW_INC_RULE_COUNTER(rule, pktlen); 3086 } else { 3087 retval = IP_FW_DENY; 3088 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 3089 } 3090 IPFW_PF_RUNLOCK(chain); 3091 #ifdef __FreeBSD__ 3092 if (ucred_cache != NULL) 3093 crfree(ucred_cache); 3094 #endif 3095 return (retval); 3096 3097 pullup_failed: 3098 if (V_fw_verbose) 3099 printf("ipfw: pullup failed\n"); 3100 return (IP_FW_DENY); 3101 } 3102 3103 /* 3104 * Set maximum number of tables that can be used in given VNET ipfw instance. 3105 */ 3106 #ifdef SYSCTL_NODE 3107 static int 3108 sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS) 3109 { 3110 int error; 3111 unsigned int ntables; 3112 3113 ntables = V_fw_tables_max; 3114 3115 error = sysctl_handle_int(oidp, &ntables, 0, req); 3116 /* Read operation or some error */ 3117 if ((error != 0) || (req->newptr == NULL)) 3118 return (error); 3119 3120 return (ipfw_resize_tables(&V_layer3_chain, ntables)); 3121 } 3122 3123 /* 3124 * Switches table namespace between global and per-set. 3125 */ 3126 static int 3127 sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS) 3128 { 3129 int error; 3130 unsigned int sets; 3131 3132 sets = V_fw_tables_sets; 3133 3134 error = sysctl_handle_int(oidp, &sets, 0, req); 3135 /* Read operation or some error */ 3136 if ((error != 0) || (req->newptr == NULL)) 3137 return (error); 3138 3139 return (ipfw_switch_tables_namespace(&V_layer3_chain, sets)); 3140 } 3141 #endif 3142 3143 /* 3144 * Module and VNET glue 3145 */ 3146 3147 /* 3148 * Stuff that must be initialised only on boot or module load 3149 */ 3150 static int 3151 ipfw_init(void) 3152 { 3153 int error = 0; 3154 3155 /* 3156 * Only print out this stuff the first time around, 3157 * when called from the sysinit code. 3158 */ 3159 printf("ipfw2 " 3160 #ifdef INET6 3161 "(+ipv6) " 3162 #endif 3163 "initialized, divert %s, nat %s, " 3164 "default to %s, logging ", 3165 #ifdef IPDIVERT 3166 "enabled", 3167 #else 3168 "loadable", 3169 #endif 3170 #ifdef IPFIREWALL_NAT 3171 "enabled", 3172 #else 3173 "loadable", 3174 #endif 3175 default_to_accept ? "accept" : "deny"); 3176 3177 /* 3178 * Note: V_xxx variables can be accessed here but the vnet specific 3179 * initializer may not have been called yet for the VIMAGE case. 3180 * Tuneables will have been processed. We will print out values for 3181 * the default vnet. 3182 * XXX This should all be rationalized AFTER 8.0 3183 */ 3184 if (V_fw_verbose == 0) 3185 printf("disabled\n"); 3186 else if (V_verbose_limit == 0) 3187 printf("unlimited\n"); 3188 else 3189 printf("limited to %d packets/entry by default\n", 3190 V_verbose_limit); 3191 3192 /* Check user-supplied table count for validness */ 3193 if (default_fw_tables > IPFW_TABLES_MAX) 3194 default_fw_tables = IPFW_TABLES_MAX; 3195 3196 ipfw_init_sopt_handler(); 3197 ipfw_init_obj_rewriter(); 3198 ipfw_iface_init(); 3199 return (error); 3200 } 3201 3202 /* 3203 * Called for the removal of the last instance only on module unload. 3204 */ 3205 static void 3206 ipfw_destroy(void) 3207 { 3208 3209 ipfw_iface_destroy(); 3210 ipfw_destroy_sopt_handler(); 3211 ipfw_destroy_obj_rewriter(); 3212 printf("IP firewall unloaded\n"); 3213 } 3214 3215 /* 3216 * Stuff that must be initialized for every instance 3217 * (including the first of course). 3218 */ 3219 static int 3220 vnet_ipfw_init(const void *unused) 3221 { 3222 int error, first; 3223 struct ip_fw *rule = NULL; 3224 struct ip_fw_chain *chain; 3225 3226 chain = &V_layer3_chain; 3227 3228 first = IS_DEFAULT_VNET(curvnet) ? 1 : 0; 3229 3230 /* First set up some values that are compile time options */ 3231 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 3232 V_fw_deny_unknown_exthdrs = 1; 3233 #ifdef IPFIREWALL_VERBOSE 3234 V_fw_verbose = 1; 3235 #endif 3236 #ifdef IPFIREWALL_VERBOSE_LIMIT 3237 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 3238 #endif 3239 #ifdef IPFIREWALL_NAT 3240 LIST_INIT(&chain->nat); 3241 #endif 3242 3243 /* Init shared services hash table */ 3244 ipfw_init_srv(chain); 3245 3246 ipfw_init_counters(); 3247 /* Set initial number of tables */ 3248 V_fw_tables_max = default_fw_tables; 3249 error = ipfw_init_tables(chain, first); 3250 if (error) { 3251 printf("ipfw2: setting up tables failed\n"); 3252 free(chain->map, M_IPFW); 3253 free(rule, M_IPFW); 3254 return (ENOSPC); 3255 } 3256 3257 IPFW_LOCK_INIT(chain); 3258 3259 /* fill and insert the default rule */ 3260 rule = ipfw_alloc_rule(chain, sizeof(struct ip_fw)); 3261 rule->cmd_len = 1; 3262 rule->cmd[0].len = 1; 3263 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY; 3264 chain->default_rule = rule; 3265 ipfw_add_protected_rule(chain, rule, 0); 3266 3267 ipfw_dyn_init(chain); 3268 ipfw_eaction_init(chain, first); 3269 #ifdef LINEAR_SKIPTO 3270 ipfw_init_skipto_cache(chain); 3271 #endif 3272 ipfw_bpf_init(first); 3273 3274 /* First set up some values that are compile time options */ 3275 V_ipfw_vnet_ready = 1; /* Open for business */ 3276 3277 /* 3278 * Hook the sockopt handler and pfil hooks for ipv4 and ipv6. 3279 * Even if the latter two fail we still keep the module alive 3280 * because the sockopt and layer2 paths are still useful. 3281 * ipfw[6]_hook return 0 on success, ENOENT on failure, 3282 * so we can ignore the exact return value and just set a flag. 3283 * 3284 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so 3285 * changes in the underlying (per-vnet) variables trigger 3286 * immediate hook()/unhook() calls. 3287 * In layer2 we have the same behaviour, except that V_ether_ipfw 3288 * is checked on each packet because there are no pfil hooks. 3289 */ 3290 V_ip_fw_ctl_ptr = ipfw_ctl3; 3291 error = ipfw_attach_hooks(1); 3292 return (error); 3293 } 3294 3295 /* 3296 * Called for the removal of each instance. 3297 */ 3298 static int 3299 vnet_ipfw_uninit(const void *unused) 3300 { 3301 struct ip_fw *reap; 3302 struct ip_fw_chain *chain = &V_layer3_chain; 3303 int i, last; 3304 3305 V_ipfw_vnet_ready = 0; /* tell new callers to go away */ 3306 /* 3307 * disconnect from ipv4, ipv6, layer2 and sockopt. 3308 * Then grab, release and grab again the WLOCK so we make 3309 * sure the update is propagated and nobody will be in. 3310 */ 3311 (void)ipfw_attach_hooks(0 /* detach */); 3312 V_ip_fw_ctl_ptr = NULL; 3313 3314 last = IS_DEFAULT_VNET(curvnet) ? 1 : 0; 3315 3316 IPFW_UH_WLOCK(chain); 3317 IPFW_UH_WUNLOCK(chain); 3318 3319 ipfw_dyn_uninit(0); /* run the callout_drain */ 3320 3321 IPFW_UH_WLOCK(chain); 3322 3323 reap = NULL; 3324 IPFW_WLOCK(chain); 3325 for (i = 0; i < chain->n_rules; i++) 3326 ipfw_reap_add(chain, &reap, chain->map[i]); 3327 free(chain->map, M_IPFW); 3328 #ifdef LINEAR_SKIPTO 3329 ipfw_destroy_skipto_cache(chain); 3330 #endif 3331 IPFW_WUNLOCK(chain); 3332 IPFW_UH_WUNLOCK(chain); 3333 ipfw_destroy_tables(chain, last); 3334 ipfw_eaction_uninit(chain, last); 3335 if (reap != NULL) 3336 ipfw_reap_rules(reap); 3337 vnet_ipfw_iface_destroy(chain); 3338 ipfw_destroy_srv(chain); 3339 IPFW_LOCK_DESTROY(chain); 3340 ipfw_dyn_uninit(1); /* free the remaining parts */ 3341 ipfw_destroy_counters(); 3342 ipfw_bpf_uninit(last); 3343 return (0); 3344 } 3345 3346 /* 3347 * Module event handler. 3348 * In general we have the choice of handling most of these events by the 3349 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to 3350 * use the SYSINIT handlers as they are more capable of expressing the 3351 * flow of control during module and vnet operations, so this is just 3352 * a skeleton. Note there is no SYSINIT equivalent of the module 3353 * SHUTDOWN handler, but we don't have anything to do in that case anyhow. 3354 */ 3355 static int 3356 ipfw_modevent(module_t mod, int type, void *unused) 3357 { 3358 int err = 0; 3359 3360 switch (type) { 3361 case MOD_LOAD: 3362 /* Called once at module load or 3363 * system boot if compiled in. */ 3364 break; 3365 case MOD_QUIESCE: 3366 /* Called before unload. May veto unloading. */ 3367 break; 3368 case MOD_UNLOAD: 3369 /* Called during unload. */ 3370 break; 3371 case MOD_SHUTDOWN: 3372 /* Called during system shutdown. */ 3373 break; 3374 default: 3375 err = EOPNOTSUPP; 3376 break; 3377 } 3378 return err; 3379 } 3380 3381 static moduledata_t ipfwmod = { 3382 "ipfw", 3383 ipfw_modevent, 3384 0 3385 }; 3386 3387 /* Define startup order. */ 3388 #define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_FIREWALL 3389 #define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */ 3390 #define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */ 3391 #define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */ 3392 3393 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER); 3394 FEATURE(ipfw_ctl3, "ipfw new sockopt calls"); 3395 MODULE_VERSION(ipfw, 3); 3396 /* should declare some dependencies here */ 3397 3398 /* 3399 * Starting up. Done in order after ipfwmod() has been called. 3400 * VNET_SYSINIT is also called for each existing vnet and each new vnet. 3401 */ 3402 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 3403 ipfw_init, NULL); 3404 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 3405 vnet_ipfw_init, NULL); 3406 3407 /* 3408 * Closing up shop. These are done in REVERSE ORDER, but still 3409 * after ipfwmod() has been called. Not called on reboot. 3410 * VNET_SYSUNINIT is also called for each exiting vnet as it exits. 3411 * or when the module is unloaded. 3412 */ 3413 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 3414 ipfw_destroy, NULL); 3415 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 3416 vnet_ipfw_uninit, NULL); 3417 /* end of file */ 3418