1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2002-2009 Luigi Rizzo, Universita` di Pisa 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 /* 32 * The FreeBSD IP packet firewall, main file 33 */ 34 35 #include "opt_ipfw.h" 36 #include "opt_ipdivert.h" 37 #include "opt_inet.h" 38 #ifndef INET 39 #error "IPFIREWALL requires INET" 40 #endif /* INET */ 41 #include "opt_inet6.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/condvar.h> 46 #include <sys/counter.h> 47 #include <sys/eventhandler.h> 48 #include <sys/malloc.h> 49 #include <sys/mbuf.h> 50 #include <sys/kernel.h> 51 #include <sys/lock.h> 52 #include <sys/jail.h> 53 #include <sys/module.h> 54 #include <sys/priv.h> 55 #include <sys/proc.h> 56 #include <sys/rwlock.h> 57 #include <sys/rmlock.h> 58 #include <sys/socket.h> 59 #include <sys/socketvar.h> 60 #include <sys/sysctl.h> 61 #include <sys/syslog.h> 62 #include <sys/ucred.h> 63 #include <net/ethernet.h> /* for ETHERTYPE_IP */ 64 #include <net/if.h> 65 #include <net/if_var.h> 66 #include <net/route.h> 67 #include <net/pfil.h> 68 #include <net/vnet.h> 69 70 #include <netpfil/pf/pf_mtag.h> 71 72 #include <netinet/in.h> 73 #include <netinet/in_var.h> 74 #include <netinet/in_pcb.h> 75 #include <netinet/ip.h> 76 #include <netinet/ip_var.h> 77 #include <netinet/ip_icmp.h> 78 #include <netinet/ip_fw.h> 79 #include <netinet/ip_carp.h> 80 #include <netinet/pim.h> 81 #include <netinet/tcp_var.h> 82 #include <netinet/udp.h> 83 #include <netinet/udp_var.h> 84 #include <netinet/sctp.h> 85 #include <netinet/sctp_crc32.h> 86 #include <netinet/sctp_header.h> 87 88 #include <netinet/ip6.h> 89 #include <netinet/icmp6.h> 90 #include <netinet/in_fib.h> 91 #ifdef INET6 92 #include <netinet6/in6_fib.h> 93 #include <netinet6/in6_pcb.h> 94 #include <netinet6/scope6_var.h> 95 #include <netinet6/ip6_var.h> 96 #endif 97 98 #include <net/if_gre.h> /* for struct grehdr */ 99 100 #include <netpfil/ipfw/ip_fw_private.h> 101 102 #include <machine/in_cksum.h> /* XXX for in_cksum */ 103 104 #ifdef MAC 105 #include <security/mac/mac_framework.h> 106 #endif 107 108 /* 109 * static variables followed by global ones. 110 * All ipfw global variables are here. 111 */ 112 113 static VNET_DEFINE(int, fw_deny_unknown_exthdrs); 114 #define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs) 115 116 static VNET_DEFINE(int, fw_permit_single_frag6) = 1; 117 #define V_fw_permit_single_frag6 VNET(fw_permit_single_frag6) 118 119 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 120 static int default_to_accept = 1; 121 #else 122 static int default_to_accept; 123 #endif 124 125 VNET_DEFINE(int, autoinc_step); 126 VNET_DEFINE(int, fw_one_pass) = 1; 127 128 VNET_DEFINE(unsigned int, fw_tables_max); 129 VNET_DEFINE(unsigned int, fw_tables_sets) = 0; /* Don't use set-aware tables */ 130 /* Use 128 tables by default */ 131 static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT; 132 133 #ifndef LINEAR_SKIPTO 134 static int jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 135 int tablearg, int jump_backwards); 136 #define JUMP(ch, f, num, targ, back) jump_fast(ch, f, num, targ, back) 137 #else 138 static int jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num, 139 int tablearg, int jump_backwards); 140 #define JUMP(ch, f, num, targ, back) jump_linear(ch, f, num, targ, back) 141 #endif 142 143 /* 144 * Each rule belongs to one of 32 different sets (0..31). 145 * The variable set_disable contains one bit per set. 146 * If the bit is set, all rules in the corresponding set 147 * are disabled. Set RESVD_SET(31) is reserved for the default rule 148 * and rules that are not deleted by the flush command, 149 * and CANNOT be disabled. 150 * Rules in set RESVD_SET can only be deleted individually. 151 */ 152 VNET_DEFINE(u_int32_t, set_disable); 153 #define V_set_disable VNET(set_disable) 154 155 VNET_DEFINE(int, fw_verbose); 156 /* counter for ipfw_log(NULL...) */ 157 VNET_DEFINE(u_int64_t, norule_counter); 158 VNET_DEFINE(int, verbose_limit); 159 160 /* layer3_chain contains the list of rules for layer 3 */ 161 VNET_DEFINE(struct ip_fw_chain, layer3_chain); 162 163 /* ipfw_vnet_ready controls when we are open for business */ 164 VNET_DEFINE(int, ipfw_vnet_ready) = 0; 165 166 VNET_DEFINE(int, ipfw_nat_ready) = 0; 167 168 ipfw_nat_t *ipfw_nat_ptr = NULL; 169 struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int); 170 ipfw_nat_cfg_t *ipfw_nat_cfg_ptr; 171 ipfw_nat_cfg_t *ipfw_nat_del_ptr; 172 ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr; 173 ipfw_nat_cfg_t *ipfw_nat_get_log_ptr; 174 175 #ifdef SYSCTL_NODE 176 uint32_t dummy_def = IPFW_DEFAULT_RULE; 177 static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS); 178 static int sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS); 179 180 SYSBEGIN(f3) 181 182 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 183 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 184 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0, 185 "Only do a single pass through ipfw when using dummynet(4)"); 186 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, 187 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(autoinc_step), 0, 188 "Rule number auto-increment step"); 189 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, 190 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0, 191 "Log matches to ipfw rules"); 192 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, 193 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(verbose_limit), 0, 194 "Set upper limit of matches of ipfw rules logged"); 195 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD, 196 &dummy_def, 0, 197 "The default/max possible rule number."); 198 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_max, 199 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, 0, 0, sysctl_ipfw_table_num, "IU", 200 "Maximum number of concurrently used tables"); 201 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_sets, 202 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, 203 0, 0, sysctl_ipfw_tables_sets, "IU", 204 "Use per-set namespace for tables"); 205 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN, 206 &default_to_accept, 0, 207 "Make the default rule accept all packets."); 208 TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables); 209 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, 210 CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0, 211 "Number of static rules"); 212 213 #ifdef INET6 214 SYSCTL_DECL(_net_inet6_ip6); 215 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 216 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs, 217 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE, 218 &VNET_NAME(fw_deny_unknown_exthdrs), 0, 219 "Deny packets with unknown IPv6 Extension Headers"); 220 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6, 221 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE, 222 &VNET_NAME(fw_permit_single_frag6), 0, 223 "Permit single packet IPv6 fragments"); 224 #endif /* INET6 */ 225 226 SYSEND 227 228 #endif /* SYSCTL_NODE */ 229 230 231 /* 232 * Some macros used in the various matching options. 233 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 234 * Other macros just cast void * into the appropriate type 235 */ 236 #define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 237 #define TCP(p) ((struct tcphdr *)(p)) 238 #define SCTP(p) ((struct sctphdr *)(p)) 239 #define UDP(p) ((struct udphdr *)(p)) 240 #define ICMP(p) ((struct icmphdr *)(p)) 241 #define ICMP6(p) ((struct icmp6_hdr *)(p)) 242 243 static __inline int 244 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 245 { 246 int type = icmp->icmp_type; 247 248 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 249 } 250 251 #define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 252 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 253 254 static int 255 is_icmp_query(struct icmphdr *icmp) 256 { 257 int type = icmp->icmp_type; 258 259 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 260 } 261 #undef TT 262 263 /* 264 * The following checks use two arrays of 8 or 16 bits to store the 265 * bits that we want set or clear, respectively. They are in the 266 * low and high half of cmd->arg1 or cmd->d[0]. 267 * 268 * We scan options and store the bits we find set. We succeed if 269 * 270 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 271 * 272 * The code is sometimes optimized not to store additional variables. 273 */ 274 275 static int 276 flags_match(ipfw_insn *cmd, u_int8_t bits) 277 { 278 u_char want_clear; 279 bits = ~bits; 280 281 if ( ((cmd->arg1 & 0xff) & bits) != 0) 282 return 0; /* some bits we want set were clear */ 283 want_clear = (cmd->arg1 >> 8) & 0xff; 284 if ( (want_clear & bits) != want_clear) 285 return 0; /* some bits we want clear were set */ 286 return 1; 287 } 288 289 static int 290 ipopts_match(struct ip *ip, ipfw_insn *cmd) 291 { 292 int optlen, bits = 0; 293 u_char *cp = (u_char *)(ip + 1); 294 int x = (ip->ip_hl << 2) - sizeof (struct ip); 295 296 for (; x > 0; x -= optlen, cp += optlen) { 297 int opt = cp[IPOPT_OPTVAL]; 298 299 if (opt == IPOPT_EOL) 300 break; 301 if (opt == IPOPT_NOP) 302 optlen = 1; 303 else { 304 optlen = cp[IPOPT_OLEN]; 305 if (optlen <= 0 || optlen > x) 306 return 0; /* invalid or truncated */ 307 } 308 switch (opt) { 309 310 default: 311 break; 312 313 case IPOPT_LSRR: 314 bits |= IP_FW_IPOPT_LSRR; 315 break; 316 317 case IPOPT_SSRR: 318 bits |= IP_FW_IPOPT_SSRR; 319 break; 320 321 case IPOPT_RR: 322 bits |= IP_FW_IPOPT_RR; 323 break; 324 325 case IPOPT_TS: 326 bits |= IP_FW_IPOPT_TS; 327 break; 328 } 329 } 330 return (flags_match(cmd, bits)); 331 } 332 333 static int 334 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 335 { 336 int optlen, bits = 0; 337 u_char *cp = (u_char *)(tcp + 1); 338 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 339 340 for (; x > 0; x -= optlen, cp += optlen) { 341 int opt = cp[0]; 342 if (opt == TCPOPT_EOL) 343 break; 344 if (opt == TCPOPT_NOP) 345 optlen = 1; 346 else { 347 optlen = cp[1]; 348 if (optlen <= 0) 349 break; 350 } 351 352 switch (opt) { 353 354 default: 355 break; 356 357 case TCPOPT_MAXSEG: 358 bits |= IP_FW_TCPOPT_MSS; 359 break; 360 361 case TCPOPT_WINDOW: 362 bits |= IP_FW_TCPOPT_WINDOW; 363 break; 364 365 case TCPOPT_SACK_PERMITTED: 366 case TCPOPT_SACK: 367 bits |= IP_FW_TCPOPT_SACK; 368 break; 369 370 case TCPOPT_TIMESTAMP: 371 bits |= IP_FW_TCPOPT_TS; 372 break; 373 374 } 375 } 376 return (flags_match(cmd, bits)); 377 } 378 379 static int 380 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain, 381 uint32_t *tablearg) 382 { 383 384 if (ifp == NULL) /* no iface with this packet, match fails */ 385 return (0); 386 387 /* Check by name or by IP address */ 388 if (cmd->name[0] != '\0') { /* match by name */ 389 if (cmd->name[0] == '\1') /* use tablearg to match */ 390 return ipfw_lookup_table(chain, cmd->p.kidx, 0, 391 &ifp->if_index, tablearg); 392 /* Check name */ 393 if (cmd->p.glob) { 394 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 395 return(1); 396 } else { 397 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 398 return(1); 399 } 400 } else { 401 #if !defined(USERSPACE) && defined(__FreeBSD__) /* and OSX too ? */ 402 struct ifaddr *ia; 403 404 if_addr_rlock(ifp); 405 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 406 if (ia->ifa_addr->sa_family != AF_INET) 407 continue; 408 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 409 (ia->ifa_addr))->sin_addr.s_addr) { 410 if_addr_runlock(ifp); 411 return(1); /* match */ 412 } 413 } 414 if_addr_runlock(ifp); 415 #endif /* __FreeBSD__ */ 416 } 417 return(0); /* no match, fail ... */ 418 } 419 420 /* 421 * The verify_path function checks if a route to the src exists and 422 * if it is reachable via ifp (when provided). 423 * 424 * The 'verrevpath' option checks that the interface that an IP packet 425 * arrives on is the same interface that traffic destined for the 426 * packet's source address would be routed out of. 427 * The 'versrcreach' option just checks that the source address is 428 * reachable via any route (except default) in the routing table. 429 * These two are a measure to block forged packets. This is also 430 * commonly known as "anti-spoofing" or Unicast Reverse Path 431 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 432 * is purposely reminiscent of the Cisco IOS command, 433 * 434 * ip verify unicast reverse-path 435 * ip verify unicast source reachable-via any 436 * 437 * which implements the same functionality. But note that the syntax 438 * is misleading, and the check may be performed on all IP packets 439 * whether unicast, multicast, or broadcast. 440 */ 441 static int 442 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib) 443 { 444 #if defined(USERSPACE) || !defined(__FreeBSD__) 445 return 0; 446 #else 447 struct nhop4_basic nh4; 448 449 if (fib4_lookup_nh_basic(fib, src, NHR_IFAIF, 0, &nh4) != 0) 450 return (0); 451 452 /* 453 * If ifp is provided, check for equality with rtentry. 454 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 455 * in order to pass packets injected back by if_simloop(): 456 * routing entry (via lo0) for our own address 457 * may exist, so we need to handle routing assymetry. 458 */ 459 if (ifp != NULL && ifp != nh4.nh_ifp) 460 return (0); 461 462 /* if no ifp provided, check if rtentry is not default route */ 463 if (ifp == NULL && (nh4.nh_flags & NHF_DEFAULT) != 0) 464 return (0); 465 466 /* or if this is a blackhole/reject route */ 467 if (ifp == NULL && (nh4.nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0) 468 return (0); 469 470 /* found valid route */ 471 return 1; 472 #endif /* __FreeBSD__ */ 473 } 474 475 /* 476 * Generate an SCTP packet containing an ABORT chunk. The verification tag 477 * is given by vtag. The T-bit is set in the ABORT chunk if and only if 478 * reflected is not 0. 479 */ 480 481 static struct mbuf * 482 ipfw_send_abort(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t vtag, 483 int reflected) 484 { 485 struct mbuf *m; 486 struct ip *ip; 487 #ifdef INET6 488 struct ip6_hdr *ip6; 489 #endif 490 struct sctphdr *sctp; 491 struct sctp_chunkhdr *chunk; 492 u_int16_t hlen, plen, tlen; 493 494 MGETHDR(m, M_NOWAIT, MT_DATA); 495 if (m == NULL) 496 return (NULL); 497 498 M_SETFIB(m, id->fib); 499 #ifdef MAC 500 if (replyto != NULL) 501 mac_netinet_firewall_reply(replyto, m); 502 else 503 mac_netinet_firewall_send(m); 504 #else 505 (void)replyto; /* don't warn about unused arg */ 506 #endif 507 508 switch (id->addr_type) { 509 case 4: 510 hlen = sizeof(struct ip); 511 break; 512 #ifdef INET6 513 case 6: 514 hlen = sizeof(struct ip6_hdr); 515 break; 516 #endif 517 default: 518 /* XXX: log me?!? */ 519 FREE_PKT(m); 520 return (NULL); 521 } 522 plen = sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr); 523 tlen = hlen + plen; 524 m->m_data += max_linkhdr; 525 m->m_flags |= M_SKIP_FIREWALL; 526 m->m_pkthdr.len = m->m_len = tlen; 527 m->m_pkthdr.rcvif = NULL; 528 bzero(m->m_data, tlen); 529 530 switch (id->addr_type) { 531 case 4: 532 ip = mtod(m, struct ip *); 533 534 ip->ip_v = 4; 535 ip->ip_hl = sizeof(struct ip) >> 2; 536 ip->ip_tos = IPTOS_LOWDELAY; 537 ip->ip_len = htons(tlen); 538 ip->ip_id = htons(0); 539 ip->ip_off = htons(0); 540 ip->ip_ttl = V_ip_defttl; 541 ip->ip_p = IPPROTO_SCTP; 542 ip->ip_sum = 0; 543 ip->ip_src.s_addr = htonl(id->dst_ip); 544 ip->ip_dst.s_addr = htonl(id->src_ip); 545 546 sctp = (struct sctphdr *)(ip + 1); 547 break; 548 #ifdef INET6 549 case 6: 550 ip6 = mtod(m, struct ip6_hdr *); 551 552 ip6->ip6_vfc = IPV6_VERSION; 553 ip6->ip6_plen = htons(plen); 554 ip6->ip6_nxt = IPPROTO_SCTP; 555 ip6->ip6_hlim = IPV6_DEFHLIM; 556 ip6->ip6_src = id->dst_ip6; 557 ip6->ip6_dst = id->src_ip6; 558 559 sctp = (struct sctphdr *)(ip6 + 1); 560 break; 561 #endif 562 } 563 564 sctp->src_port = htons(id->dst_port); 565 sctp->dest_port = htons(id->src_port); 566 sctp->v_tag = htonl(vtag); 567 sctp->checksum = htonl(0); 568 569 chunk = (struct sctp_chunkhdr *)(sctp + 1); 570 chunk->chunk_type = SCTP_ABORT_ASSOCIATION; 571 chunk->chunk_flags = 0; 572 if (reflected != 0) { 573 chunk->chunk_flags |= SCTP_HAD_NO_TCB; 574 } 575 chunk->chunk_length = htons(sizeof(struct sctp_chunkhdr)); 576 577 sctp->checksum = sctp_calculate_cksum(m, hlen); 578 579 return (m); 580 } 581 582 /* 583 * Generate a TCP packet, containing either a RST or a keepalive. 584 * When flags & TH_RST, we are sending a RST packet, because of a 585 * "reset" action matched the packet. 586 * Otherwise we are sending a keepalive, and flags & TH_ 587 * The 'replyto' mbuf is the mbuf being replied to, if any, and is required 588 * so that MAC can label the reply appropriately. 589 */ 590 struct mbuf * 591 ipfw_send_pkt(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t seq, 592 u_int32_t ack, int flags) 593 { 594 struct mbuf *m = NULL; /* stupid compiler */ 595 struct ip *h = NULL; /* stupid compiler */ 596 #ifdef INET6 597 struct ip6_hdr *h6 = NULL; 598 #endif 599 struct tcphdr *th = NULL; 600 int len, dir; 601 602 MGETHDR(m, M_NOWAIT, MT_DATA); 603 if (m == NULL) 604 return (NULL); 605 606 M_SETFIB(m, id->fib); 607 #ifdef MAC 608 if (replyto != NULL) 609 mac_netinet_firewall_reply(replyto, m); 610 else 611 mac_netinet_firewall_send(m); 612 #else 613 (void)replyto; /* don't warn about unused arg */ 614 #endif 615 616 switch (id->addr_type) { 617 case 4: 618 len = sizeof(struct ip) + sizeof(struct tcphdr); 619 break; 620 #ifdef INET6 621 case 6: 622 len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 623 break; 624 #endif 625 default: 626 /* XXX: log me?!? */ 627 FREE_PKT(m); 628 return (NULL); 629 } 630 dir = ((flags & (TH_SYN | TH_RST)) == TH_SYN); 631 632 m->m_data += max_linkhdr; 633 m->m_flags |= M_SKIP_FIREWALL; 634 m->m_pkthdr.len = m->m_len = len; 635 m->m_pkthdr.rcvif = NULL; 636 bzero(m->m_data, len); 637 638 switch (id->addr_type) { 639 case 4: 640 h = mtod(m, struct ip *); 641 642 /* prepare for checksum */ 643 h->ip_p = IPPROTO_TCP; 644 h->ip_len = htons(sizeof(struct tcphdr)); 645 if (dir) { 646 h->ip_src.s_addr = htonl(id->src_ip); 647 h->ip_dst.s_addr = htonl(id->dst_ip); 648 } else { 649 h->ip_src.s_addr = htonl(id->dst_ip); 650 h->ip_dst.s_addr = htonl(id->src_ip); 651 } 652 653 th = (struct tcphdr *)(h + 1); 654 break; 655 #ifdef INET6 656 case 6: 657 h6 = mtod(m, struct ip6_hdr *); 658 659 /* prepare for checksum */ 660 h6->ip6_nxt = IPPROTO_TCP; 661 h6->ip6_plen = htons(sizeof(struct tcphdr)); 662 if (dir) { 663 h6->ip6_src = id->src_ip6; 664 h6->ip6_dst = id->dst_ip6; 665 } else { 666 h6->ip6_src = id->dst_ip6; 667 h6->ip6_dst = id->src_ip6; 668 } 669 670 th = (struct tcphdr *)(h6 + 1); 671 break; 672 #endif 673 } 674 675 if (dir) { 676 th->th_sport = htons(id->src_port); 677 th->th_dport = htons(id->dst_port); 678 } else { 679 th->th_sport = htons(id->dst_port); 680 th->th_dport = htons(id->src_port); 681 } 682 th->th_off = sizeof(struct tcphdr) >> 2; 683 684 if (flags & TH_RST) { 685 if (flags & TH_ACK) { 686 th->th_seq = htonl(ack); 687 th->th_flags = TH_RST; 688 } else { 689 if (flags & TH_SYN) 690 seq++; 691 th->th_ack = htonl(seq); 692 th->th_flags = TH_RST | TH_ACK; 693 } 694 } else { 695 /* 696 * Keepalive - use caller provided sequence numbers 697 */ 698 th->th_seq = htonl(seq); 699 th->th_ack = htonl(ack); 700 th->th_flags = TH_ACK; 701 } 702 703 switch (id->addr_type) { 704 case 4: 705 th->th_sum = in_cksum(m, len); 706 707 /* finish the ip header */ 708 h->ip_v = 4; 709 h->ip_hl = sizeof(*h) >> 2; 710 h->ip_tos = IPTOS_LOWDELAY; 711 h->ip_off = htons(0); 712 h->ip_len = htons(len); 713 h->ip_ttl = V_ip_defttl; 714 h->ip_sum = 0; 715 break; 716 #ifdef INET6 717 case 6: 718 th->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(*h6), 719 sizeof(struct tcphdr)); 720 721 /* finish the ip6 header */ 722 h6->ip6_vfc |= IPV6_VERSION; 723 h6->ip6_hlim = IPV6_DEFHLIM; 724 break; 725 #endif 726 } 727 728 return (m); 729 } 730 731 #ifdef INET6 732 /* 733 * ipv6 specific rules here... 734 */ 735 static __inline int 736 icmp6type_match (int type, ipfw_insn_u32 *cmd) 737 { 738 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 739 } 740 741 static int 742 flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 743 { 744 int i; 745 for (i=0; i <= cmd->o.arg1; ++i ) 746 if (curr_flow == cmd->d[i] ) 747 return 1; 748 return 0; 749 } 750 751 /* support for IP6_*_ME opcodes */ 752 static const struct in6_addr lla_mask = {{{ 753 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 754 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff 755 }}}; 756 757 static int 758 ipfw_localip6(struct in6_addr *in6) 759 { 760 struct rm_priotracker in6_ifa_tracker; 761 struct in6_ifaddr *ia; 762 763 if (IN6_IS_ADDR_MULTICAST(in6)) 764 return (0); 765 766 if (!IN6_IS_ADDR_LINKLOCAL(in6)) 767 return (in6_localip(in6)); 768 769 IN6_IFADDR_RLOCK(&in6_ifa_tracker); 770 TAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) { 771 if (!IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) 772 continue; 773 if (IN6_ARE_MASKED_ADDR_EQUAL(&ia->ia_addr.sin6_addr, 774 in6, &lla_mask)) { 775 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 776 return (1); 777 } 778 } 779 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 780 return (0); 781 } 782 783 static int 784 verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib) 785 { 786 struct nhop6_basic nh6; 787 788 if (IN6_IS_SCOPE_LINKLOCAL(src)) 789 return (1); 790 791 if (fib6_lookup_nh_basic(fib, src, 0, NHR_IFAIF, 0, &nh6) != 0) 792 return (0); 793 794 /* If ifp is provided, check for equality with route table. */ 795 if (ifp != NULL && ifp != nh6.nh_ifp) 796 return (0); 797 798 /* if no ifp provided, check if rtentry is not default route */ 799 if (ifp == NULL && (nh6.nh_flags & NHF_DEFAULT) != 0) 800 return (0); 801 802 /* or if this is a blackhole/reject route */ 803 if (ifp == NULL && (nh6.nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0) 804 return (0); 805 806 /* found valid route */ 807 return 1; 808 } 809 810 static int 811 is_icmp6_query(int icmp6_type) 812 { 813 if ((icmp6_type <= ICMP6_MAXTYPE) && 814 (icmp6_type == ICMP6_ECHO_REQUEST || 815 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 816 icmp6_type == ICMP6_WRUREQUEST || 817 icmp6_type == ICMP6_FQDN_QUERY || 818 icmp6_type == ICMP6_NI_QUERY)) 819 return (1); 820 821 return (0); 822 } 823 824 static int 825 map_icmp_unreach(int code) 826 { 827 828 /* RFC 7915 p4.2 */ 829 switch (code) { 830 case ICMP_UNREACH_NET: 831 case ICMP_UNREACH_HOST: 832 case ICMP_UNREACH_SRCFAIL: 833 case ICMP_UNREACH_NET_UNKNOWN: 834 case ICMP_UNREACH_HOST_UNKNOWN: 835 case ICMP_UNREACH_TOSNET: 836 case ICMP_UNREACH_TOSHOST: 837 return (ICMP6_DST_UNREACH_NOROUTE); 838 case ICMP_UNREACH_PORT: 839 return (ICMP6_DST_UNREACH_NOPORT); 840 default: 841 /* 842 * Map the rest of codes into admit prohibited. 843 * XXX: unreach proto should be mapped into ICMPv6 844 * parameter problem, but we use only unreach type. 845 */ 846 return (ICMP6_DST_UNREACH_ADMIN); 847 } 848 } 849 850 static void 851 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 852 { 853 struct mbuf *m; 854 855 m = args->m; 856 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 857 struct tcphdr *tcp; 858 tcp = (struct tcphdr *)((char *)ip6 + hlen); 859 860 if ((tcp->th_flags & TH_RST) == 0) { 861 struct mbuf *m0; 862 m0 = ipfw_send_pkt(args->m, &(args->f_id), 863 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 864 tcp->th_flags | TH_RST); 865 if (m0 != NULL) 866 ip6_output(m0, NULL, NULL, 0, NULL, NULL, 867 NULL); 868 } 869 FREE_PKT(m); 870 } else if (code == ICMP6_UNREACH_ABORT && 871 args->f_id.proto == IPPROTO_SCTP) { 872 struct mbuf *m0; 873 struct sctphdr *sctp; 874 u_int32_t v_tag; 875 int reflected; 876 877 sctp = (struct sctphdr *)((char *)ip6 + hlen); 878 reflected = 1; 879 v_tag = ntohl(sctp->v_tag); 880 /* Investigate the first chunk header if available */ 881 if (m->m_len >= hlen + sizeof(struct sctphdr) + 882 sizeof(struct sctp_chunkhdr)) { 883 struct sctp_chunkhdr *chunk; 884 885 chunk = (struct sctp_chunkhdr *)(sctp + 1); 886 switch (chunk->chunk_type) { 887 case SCTP_INITIATION: 888 /* 889 * Packets containing an INIT chunk MUST have 890 * a zero v-tag. 891 */ 892 if (v_tag != 0) { 893 v_tag = 0; 894 break; 895 } 896 /* INIT chunk MUST NOT be bundled */ 897 if (m->m_pkthdr.len > 898 hlen + sizeof(struct sctphdr) + 899 ntohs(chunk->chunk_length) + 3) { 900 break; 901 } 902 /* Use the initiate tag if available */ 903 if ((m->m_len >= hlen + sizeof(struct sctphdr) + 904 sizeof(struct sctp_chunkhdr) + 905 offsetof(struct sctp_init, a_rwnd))) { 906 struct sctp_init *init; 907 908 init = (struct sctp_init *)(chunk + 1); 909 v_tag = ntohl(init->initiate_tag); 910 reflected = 0; 911 } 912 break; 913 case SCTP_ABORT_ASSOCIATION: 914 /* 915 * If the packet contains an ABORT chunk, don't 916 * reply. 917 * XXX: We should search through all chunks, 918 * but don't do to avoid attacks. 919 */ 920 v_tag = 0; 921 break; 922 } 923 } 924 if (v_tag == 0) { 925 m0 = NULL; 926 } else { 927 m0 = ipfw_send_abort(args->m, &(args->f_id), v_tag, 928 reflected); 929 } 930 if (m0 != NULL) 931 ip6_output(m0, NULL, NULL, 0, NULL, NULL, NULL); 932 FREE_PKT(m); 933 } else if (code != ICMP6_UNREACH_RST && code != ICMP6_UNREACH_ABORT) { 934 /* Send an ICMPv6 unreach. */ 935 #if 0 936 /* 937 * Unlike above, the mbufs need to line up with the ip6 hdr, 938 * as the contents are read. We need to m_adj() the 939 * needed amount. 940 * The mbuf will however be thrown away so we can adjust it. 941 * Remember we did an m_pullup on it already so we 942 * can make some assumptions about contiguousness. 943 */ 944 if (args->L3offset) 945 m_adj(m, args->L3offset); 946 #endif 947 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 948 } else 949 FREE_PKT(m); 950 951 args->m = NULL; 952 } 953 954 #endif /* INET6 */ 955 956 957 /* 958 * sends a reject message, consuming the mbuf passed as an argument. 959 */ 960 static void 961 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip) 962 { 963 964 #if 0 965 /* XXX When ip is not guaranteed to be at mtod() we will 966 * need to account for this */ 967 * The mbuf will however be thrown away so we can adjust it. 968 * Remember we did an m_pullup on it already so we 969 * can make some assumptions about contiguousness. 970 */ 971 if (args->L3offset) 972 m_adj(m, args->L3offset); 973 #endif 974 if (code != ICMP_REJECT_RST && code != ICMP_REJECT_ABORT) { 975 /* Send an ICMP unreach */ 976 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 977 } else if (code == ICMP_REJECT_RST && args->f_id.proto == IPPROTO_TCP) { 978 struct tcphdr *const tcp = 979 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 980 if ( (tcp->th_flags & TH_RST) == 0) { 981 struct mbuf *m; 982 m = ipfw_send_pkt(args->m, &(args->f_id), 983 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 984 tcp->th_flags | TH_RST); 985 if (m != NULL) 986 ip_output(m, NULL, NULL, 0, NULL, NULL); 987 } 988 FREE_PKT(args->m); 989 } else if (code == ICMP_REJECT_ABORT && 990 args->f_id.proto == IPPROTO_SCTP) { 991 struct mbuf *m; 992 struct sctphdr *sctp; 993 struct sctp_chunkhdr *chunk; 994 struct sctp_init *init; 995 u_int32_t v_tag; 996 int reflected; 997 998 sctp = L3HDR(struct sctphdr, mtod(args->m, struct ip *)); 999 reflected = 1; 1000 v_tag = ntohl(sctp->v_tag); 1001 if (iplen >= (ip->ip_hl << 2) + sizeof(struct sctphdr) + 1002 sizeof(struct sctp_chunkhdr)) { 1003 /* Look at the first chunk header if available */ 1004 chunk = (struct sctp_chunkhdr *)(sctp + 1); 1005 switch (chunk->chunk_type) { 1006 case SCTP_INITIATION: 1007 /* 1008 * Packets containing an INIT chunk MUST have 1009 * a zero v-tag. 1010 */ 1011 if (v_tag != 0) { 1012 v_tag = 0; 1013 break; 1014 } 1015 /* INIT chunk MUST NOT be bundled */ 1016 if (iplen > 1017 (ip->ip_hl << 2) + sizeof(struct sctphdr) + 1018 ntohs(chunk->chunk_length) + 3) { 1019 break; 1020 } 1021 /* Use the initiate tag if available */ 1022 if ((iplen >= (ip->ip_hl << 2) + 1023 sizeof(struct sctphdr) + 1024 sizeof(struct sctp_chunkhdr) + 1025 offsetof(struct sctp_init, a_rwnd))) { 1026 init = (struct sctp_init *)(chunk + 1); 1027 v_tag = ntohl(init->initiate_tag); 1028 reflected = 0; 1029 } 1030 break; 1031 case SCTP_ABORT_ASSOCIATION: 1032 /* 1033 * If the packet contains an ABORT chunk, don't 1034 * reply. 1035 * XXX: We should search through all chunks, 1036 * but don't do to avoid attacks. 1037 */ 1038 v_tag = 0; 1039 break; 1040 } 1041 } 1042 if (v_tag == 0) { 1043 m = NULL; 1044 } else { 1045 m = ipfw_send_abort(args->m, &(args->f_id), v_tag, 1046 reflected); 1047 } 1048 if (m != NULL) 1049 ip_output(m, NULL, NULL, 0, NULL, NULL); 1050 FREE_PKT(args->m); 1051 } else 1052 FREE_PKT(args->m); 1053 args->m = NULL; 1054 } 1055 1056 /* 1057 * Support for uid/gid/jail lookup. These tests are expensive 1058 * (because we may need to look into the list of active sockets) 1059 * so we cache the results. ugid_lookupp is 0 if we have not 1060 * yet done a lookup, 1 if we succeeded, and -1 if we tried 1061 * and failed. The function always returns the match value. 1062 * We could actually spare the variable and use *uc, setting 1063 * it to '(void *)check_uidgid if we have no info, NULL if 1064 * we tried and failed, or any other value if successful. 1065 */ 1066 static int 1067 check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp, 1068 struct ucred **uc) 1069 { 1070 #if defined(USERSPACE) 1071 return 0; // not supported in userspace 1072 #else 1073 #ifndef __FreeBSD__ 1074 /* XXX */ 1075 return cred_check(insn, proto, oif, 1076 dst_ip, dst_port, src_ip, src_port, 1077 (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb); 1078 #else /* FreeBSD */ 1079 struct in_addr src_ip, dst_ip; 1080 struct inpcbinfo *pi; 1081 struct ipfw_flow_id *id; 1082 struct inpcb *pcb, *inp; 1083 struct ifnet *oif; 1084 int lookupflags; 1085 int match; 1086 1087 id = &args->f_id; 1088 inp = args->inp; 1089 oif = args->oif; 1090 1091 /* 1092 * Check to see if the UDP or TCP stack supplied us with 1093 * the PCB. If so, rather then holding a lock and looking 1094 * up the PCB, we can use the one that was supplied. 1095 */ 1096 if (inp && *ugid_lookupp == 0) { 1097 INP_LOCK_ASSERT(inp); 1098 if (inp->inp_socket != NULL) { 1099 *uc = crhold(inp->inp_cred); 1100 *ugid_lookupp = 1; 1101 } else 1102 *ugid_lookupp = -1; 1103 } 1104 /* 1105 * If we have already been here and the packet has no 1106 * PCB entry associated with it, then we can safely 1107 * assume that this is a no match. 1108 */ 1109 if (*ugid_lookupp == -1) 1110 return (0); 1111 if (id->proto == IPPROTO_TCP) { 1112 lookupflags = 0; 1113 pi = &V_tcbinfo; 1114 } else if (id->proto == IPPROTO_UDP) { 1115 lookupflags = INPLOOKUP_WILDCARD; 1116 pi = &V_udbinfo; 1117 } else if (id->proto == IPPROTO_UDPLITE) { 1118 lookupflags = INPLOOKUP_WILDCARD; 1119 pi = &V_ulitecbinfo; 1120 } else 1121 return 0; 1122 lookupflags |= INPLOOKUP_RLOCKPCB; 1123 match = 0; 1124 if (*ugid_lookupp == 0) { 1125 if (id->addr_type == 6) { 1126 #ifdef INET6 1127 if (oif == NULL) 1128 pcb = in6_pcblookup_mbuf(pi, 1129 &id->src_ip6, htons(id->src_port), 1130 &id->dst_ip6, htons(id->dst_port), 1131 lookupflags, oif, args->m); 1132 else 1133 pcb = in6_pcblookup_mbuf(pi, 1134 &id->dst_ip6, htons(id->dst_port), 1135 &id->src_ip6, htons(id->src_port), 1136 lookupflags, oif, args->m); 1137 #else 1138 *ugid_lookupp = -1; 1139 return (0); 1140 #endif 1141 } else { 1142 src_ip.s_addr = htonl(id->src_ip); 1143 dst_ip.s_addr = htonl(id->dst_ip); 1144 if (oif == NULL) 1145 pcb = in_pcblookup_mbuf(pi, 1146 src_ip, htons(id->src_port), 1147 dst_ip, htons(id->dst_port), 1148 lookupflags, oif, args->m); 1149 else 1150 pcb = in_pcblookup_mbuf(pi, 1151 dst_ip, htons(id->dst_port), 1152 src_ip, htons(id->src_port), 1153 lookupflags, oif, args->m); 1154 } 1155 if (pcb != NULL) { 1156 INP_RLOCK_ASSERT(pcb); 1157 *uc = crhold(pcb->inp_cred); 1158 *ugid_lookupp = 1; 1159 INP_RUNLOCK(pcb); 1160 } 1161 if (*ugid_lookupp == 0) { 1162 /* 1163 * We tried and failed, set the variable to -1 1164 * so we will not try again on this packet. 1165 */ 1166 *ugid_lookupp = -1; 1167 return (0); 1168 } 1169 } 1170 if (insn->o.opcode == O_UID) 1171 match = ((*uc)->cr_uid == (uid_t)insn->d[0]); 1172 else if (insn->o.opcode == O_GID) 1173 match = groupmember((gid_t)insn->d[0], *uc); 1174 else if (insn->o.opcode == O_JAIL) 1175 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]); 1176 return (match); 1177 #endif /* __FreeBSD__ */ 1178 #endif /* not supported in userspace */ 1179 } 1180 1181 /* 1182 * Helper function to set args with info on the rule after the matching 1183 * one. slot is precise, whereas we guess rule_id as they are 1184 * assigned sequentially. 1185 */ 1186 static inline void 1187 set_match(struct ip_fw_args *args, int slot, 1188 struct ip_fw_chain *chain) 1189 { 1190 args->rule.chain_id = chain->id; 1191 args->rule.slot = slot + 1; /* we use 0 as a marker */ 1192 args->rule.rule_id = 1 + chain->map[slot]->id; 1193 args->rule.rulenum = chain->map[slot]->rulenum; 1194 } 1195 1196 #ifndef LINEAR_SKIPTO 1197 /* 1198 * Helper function to enable cached rule lookups using 1199 * cached_id and cached_pos fields in ipfw rule. 1200 */ 1201 static int 1202 jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 1203 int tablearg, int jump_backwards) 1204 { 1205 int f_pos; 1206 1207 /* If possible use cached f_pos (in f->cached_pos), 1208 * whose version is written in f->cached_id 1209 * (horrible hacks to avoid changing the ABI). 1210 */ 1211 if (num != IP_FW_TARG && f->cached_id == chain->id) 1212 f_pos = f->cached_pos; 1213 else { 1214 int i = IP_FW_ARG_TABLEARG(chain, num, skipto); 1215 /* make sure we do not jump backward */ 1216 if (jump_backwards == 0 && i <= f->rulenum) 1217 i = f->rulenum + 1; 1218 if (chain->idxmap != NULL) 1219 f_pos = chain->idxmap[i]; 1220 else 1221 f_pos = ipfw_find_rule(chain, i, 0); 1222 /* update the cache */ 1223 if (num != IP_FW_TARG) { 1224 f->cached_id = chain->id; 1225 f->cached_pos = f_pos; 1226 } 1227 } 1228 1229 return (f_pos); 1230 } 1231 #else 1232 /* 1233 * Helper function to enable real fast rule lookups. 1234 */ 1235 static int 1236 jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num, 1237 int tablearg, int jump_backwards) 1238 { 1239 int f_pos; 1240 1241 num = IP_FW_ARG_TABLEARG(chain, num, skipto); 1242 /* make sure we do not jump backward */ 1243 if (jump_backwards == 0 && num <= f->rulenum) 1244 num = f->rulenum + 1; 1245 f_pos = chain->idxmap[num]; 1246 1247 return (f_pos); 1248 } 1249 #endif 1250 1251 #define TARG(k, f) IP_FW_ARG_TABLEARG(chain, k, f) 1252 /* 1253 * The main check routine for the firewall. 1254 * 1255 * All arguments are in args so we can modify them and return them 1256 * back to the caller. 1257 * 1258 * Parameters: 1259 * 1260 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 1261 * Starts with the IP header. 1262 * args->eh (in) Mac header if present, NULL for layer3 packet. 1263 * args->L3offset Number of bytes bypassed if we came from L2. 1264 * e.g. often sizeof(eh) ** NOTYET ** 1265 * args->oif Outgoing interface, NULL if packet is incoming. 1266 * The incoming interface is in the mbuf. (in) 1267 * args->divert_rule (in/out) 1268 * Skip up to the first rule past this rule number; 1269 * upon return, non-zero port number for divert or tee. 1270 * 1271 * args->rule Pointer to the last matching rule (in/out) 1272 * args->next_hop Socket we are forwarding to (out). 1273 * args->next_hop6 IPv6 next hop we are forwarding to (out). 1274 * args->f_id Addresses grabbed from the packet (out) 1275 * args->rule.info a cookie depending on rule action 1276 * 1277 * Return value: 1278 * 1279 * IP_FW_PASS the packet must be accepted 1280 * IP_FW_DENY the packet must be dropped 1281 * IP_FW_DIVERT divert packet, port in m_tag 1282 * IP_FW_TEE tee packet, port in m_tag 1283 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 1284 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 1285 * args->rule contains the matching rule, 1286 * args->rule.info has additional information. 1287 * 1288 */ 1289 int 1290 ipfw_chk(struct ip_fw_args *args) 1291 { 1292 1293 /* 1294 * Local variables holding state while processing a packet: 1295 * 1296 * IMPORTANT NOTE: to speed up the processing of rules, there 1297 * are some assumption on the values of the variables, which 1298 * are documented here. Should you change them, please check 1299 * the implementation of the various instructions to make sure 1300 * that they still work. 1301 * 1302 * args->eh The MAC header. It is non-null for a layer2 1303 * packet, it is NULL for a layer-3 packet. 1304 * **notyet** 1305 * args->L3offset Offset in the packet to the L3 (IP or equiv.) header. 1306 * 1307 * m | args->m Pointer to the mbuf, as received from the caller. 1308 * It may change if ipfw_chk() does an m_pullup, or if it 1309 * consumes the packet because it calls send_reject(). 1310 * XXX This has to change, so that ipfw_chk() never modifies 1311 * or consumes the buffer. 1312 * ip is the beginning of the ip(4 or 6) header. 1313 * Calculated by adding the L3offset to the start of data. 1314 * (Until we start using L3offset, the packet is 1315 * supposed to start with the ip header). 1316 */ 1317 struct mbuf *m = args->m; 1318 struct ip *ip = mtod(m, struct ip *); 1319 1320 /* 1321 * For rules which contain uid/gid or jail constraints, cache 1322 * a copy of the users credentials after the pcb lookup has been 1323 * executed. This will speed up the processing of rules with 1324 * these types of constraints, as well as decrease contention 1325 * on pcb related locks. 1326 */ 1327 #ifndef __FreeBSD__ 1328 struct bsd_ucred ucred_cache; 1329 #else 1330 struct ucred *ucred_cache = NULL; 1331 #endif 1332 int ucred_lookup = 0; 1333 1334 /* 1335 * oif | args->oif If NULL, ipfw_chk has been called on the 1336 * inbound path (ether_input, ip_input). 1337 * If non-NULL, ipfw_chk has been called on the outbound path 1338 * (ether_output, ip_output). 1339 */ 1340 struct ifnet *oif = args->oif; 1341 1342 int f_pos = 0; /* index of current rule in the array */ 1343 int retval = 0; 1344 1345 /* 1346 * hlen The length of the IP header. 1347 */ 1348 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 1349 1350 /* 1351 * offset The offset of a fragment. offset != 0 means that 1352 * we have a fragment at this offset of an IPv4 packet. 1353 * offset == 0 means that (if this is an IPv4 packet) 1354 * this is the first or only fragment. 1355 * For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header 1356 * or there is a single packet fragment (fragment header added 1357 * without needed). We will treat a single packet fragment as if 1358 * there was no fragment header (or log/block depending on the 1359 * V_fw_permit_single_frag6 sysctl setting). 1360 */ 1361 u_short offset = 0; 1362 u_short ip6f_mf = 0; 1363 1364 /* 1365 * Local copies of addresses. They are only valid if we have 1366 * an IP packet. 1367 * 1368 * proto The protocol. Set to 0 for non-ip packets, 1369 * or to the protocol read from the packet otherwise. 1370 * proto != 0 means that we have an IPv4 packet. 1371 * 1372 * src_port, dst_port port numbers, in HOST format. Only 1373 * valid for TCP and UDP packets. 1374 * 1375 * src_ip, dst_ip ip addresses, in NETWORK format. 1376 * Only valid for IPv4 packets. 1377 */ 1378 uint8_t proto; 1379 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 1380 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 1381 int iplen = 0; 1382 int pktlen; 1383 uint16_t etype = 0; /* Host order stored ether type */ 1384 1385 /* 1386 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 1387 * MATCH_NONE when checked and not matched (q = NULL), 1388 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) 1389 */ 1390 struct ipfw_dyn_info dyn_info; 1391 struct ip_fw *q = NULL; 1392 struct ip_fw_chain *chain = &V_layer3_chain; 1393 1394 /* 1395 * We store in ulp a pointer to the upper layer protocol header. 1396 * In the ipv4 case this is easy to determine from the header, 1397 * but for ipv6 we might have some additional headers in the middle. 1398 * ulp is NULL if not found. 1399 */ 1400 void *ulp = NULL; /* upper layer protocol pointer. */ 1401 1402 /* XXX ipv6 variables */ 1403 int is_ipv6 = 0; 1404 uint8_t icmp6_type = 0; 1405 uint16_t ext_hd = 0; /* bits vector for extension header filtering */ 1406 /* end of ipv6 variables */ 1407 1408 int is_ipv4 = 0; 1409 1410 int done = 0; /* flag to exit the outer loop */ 1411 1412 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready)) 1413 return (IP_FW_PASS); /* accept */ 1414 1415 dst_ip.s_addr = 0; /* make sure it is initialized */ 1416 src_ip.s_addr = 0; /* make sure it is initialized */ 1417 pktlen = m->m_pkthdr.len; 1418 args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */ 1419 proto = args->f_id.proto = 0; /* mark f_id invalid */ 1420 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ 1421 1422 DYN_INFO_INIT(&dyn_info); 1423 /* 1424 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 1425 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 1426 * pointer might become stale after other pullups (but we never use it 1427 * this way). 1428 */ 1429 #define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T)) 1430 #define PULLUP_LEN(_len, p, T) \ 1431 do { \ 1432 int x = (_len) + T; \ 1433 if ((m)->m_len < x) { \ 1434 args->m = m = m_pullup(m, x); \ 1435 if (m == NULL) \ 1436 goto pullup_failed; \ 1437 } \ 1438 p = (mtod(m, char *) + (_len)); \ 1439 } while (0) 1440 1441 /* 1442 * if we have an ether header, 1443 */ 1444 if (args->eh) 1445 etype = ntohs(args->eh->ether_type); 1446 1447 /* Identify IP packets and fill up variables. */ 1448 if (pktlen >= sizeof(struct ip6_hdr) && 1449 (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) { 1450 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 1451 is_ipv6 = 1; 1452 args->f_id.addr_type = 6; 1453 hlen = sizeof(struct ip6_hdr); 1454 proto = ip6->ip6_nxt; 1455 1456 /* Search extension headers to find upper layer protocols */ 1457 while (ulp == NULL && offset == 0) { 1458 switch (proto) { 1459 case IPPROTO_ICMPV6: 1460 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 1461 icmp6_type = ICMP6(ulp)->icmp6_type; 1462 break; 1463 1464 case IPPROTO_TCP: 1465 PULLUP_TO(hlen, ulp, struct tcphdr); 1466 dst_port = TCP(ulp)->th_dport; 1467 src_port = TCP(ulp)->th_sport; 1468 /* save flags for dynamic rules */ 1469 args->f_id._flags = TCP(ulp)->th_flags; 1470 break; 1471 1472 case IPPROTO_SCTP: 1473 if (pktlen >= hlen + sizeof(struct sctphdr) + 1474 sizeof(struct sctp_chunkhdr) + 1475 offsetof(struct sctp_init, a_rwnd)) 1476 PULLUP_LEN(hlen, ulp, 1477 sizeof(struct sctphdr) + 1478 sizeof(struct sctp_chunkhdr) + 1479 offsetof(struct sctp_init, a_rwnd)); 1480 else if (pktlen >= hlen + sizeof(struct sctphdr)) 1481 PULLUP_LEN(hlen, ulp, pktlen - hlen); 1482 else 1483 PULLUP_LEN(hlen, ulp, 1484 sizeof(struct sctphdr)); 1485 src_port = SCTP(ulp)->src_port; 1486 dst_port = SCTP(ulp)->dest_port; 1487 break; 1488 1489 case IPPROTO_UDP: 1490 case IPPROTO_UDPLITE: 1491 PULLUP_TO(hlen, ulp, struct udphdr); 1492 dst_port = UDP(ulp)->uh_dport; 1493 src_port = UDP(ulp)->uh_sport; 1494 break; 1495 1496 case IPPROTO_HOPOPTS: /* RFC 2460 */ 1497 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1498 ext_hd |= EXT_HOPOPTS; 1499 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1500 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1501 ulp = NULL; 1502 break; 1503 1504 case IPPROTO_ROUTING: /* RFC 2460 */ 1505 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 1506 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 1507 case 0: 1508 ext_hd |= EXT_RTHDR0; 1509 break; 1510 case 2: 1511 ext_hd |= EXT_RTHDR2; 1512 break; 1513 default: 1514 if (V_fw_verbose) 1515 printf("IPFW2: IPV6 - Unknown " 1516 "Routing Header type(%d)\n", 1517 ((struct ip6_rthdr *) 1518 ulp)->ip6r_type); 1519 if (V_fw_deny_unknown_exthdrs) 1520 return (IP_FW_DENY); 1521 break; 1522 } 1523 ext_hd |= EXT_ROUTING; 1524 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 1525 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 1526 ulp = NULL; 1527 break; 1528 1529 case IPPROTO_FRAGMENT: /* RFC 2460 */ 1530 PULLUP_TO(hlen, ulp, struct ip6_frag); 1531 ext_hd |= EXT_FRAGMENT; 1532 hlen += sizeof (struct ip6_frag); 1533 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 1534 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 1535 IP6F_OFF_MASK; 1536 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg & 1537 IP6F_MORE_FRAG; 1538 if (V_fw_permit_single_frag6 == 0 && 1539 offset == 0 && ip6f_mf == 0) { 1540 if (V_fw_verbose) 1541 printf("IPFW2: IPV6 - Invalid " 1542 "Fragment Header\n"); 1543 if (V_fw_deny_unknown_exthdrs) 1544 return (IP_FW_DENY); 1545 break; 1546 } 1547 args->f_id.extra = 1548 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 1549 ulp = NULL; 1550 break; 1551 1552 case IPPROTO_DSTOPTS: /* RFC 2460 */ 1553 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1554 ext_hd |= EXT_DSTOPTS; 1555 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1556 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1557 ulp = NULL; 1558 break; 1559 1560 case IPPROTO_AH: /* RFC 2402 */ 1561 PULLUP_TO(hlen, ulp, struct ip6_ext); 1562 ext_hd |= EXT_AH; 1563 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 1564 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 1565 ulp = NULL; 1566 break; 1567 1568 case IPPROTO_ESP: /* RFC 2406 */ 1569 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 1570 /* Anything past Seq# is variable length and 1571 * data past this ext. header is encrypted. */ 1572 ext_hd |= EXT_ESP; 1573 break; 1574 1575 case IPPROTO_NONE: /* RFC 2460 */ 1576 /* 1577 * Packet ends here, and IPv6 header has 1578 * already been pulled up. If ip6e_len!=0 1579 * then octets must be ignored. 1580 */ 1581 ulp = ip; /* non-NULL to get out of loop. */ 1582 break; 1583 1584 case IPPROTO_OSPFIGP: 1585 /* XXX OSPF header check? */ 1586 PULLUP_TO(hlen, ulp, struct ip6_ext); 1587 break; 1588 1589 case IPPROTO_PIM: 1590 /* XXX PIM header check? */ 1591 PULLUP_TO(hlen, ulp, struct pim); 1592 break; 1593 1594 case IPPROTO_GRE: /* RFC 1701 */ 1595 /* XXX GRE header check? */ 1596 PULLUP_TO(hlen, ulp, struct grehdr); 1597 break; 1598 1599 case IPPROTO_CARP: 1600 PULLUP_TO(hlen, ulp, struct carp_header); 1601 if (((struct carp_header *)ulp)->carp_version != 1602 CARP_VERSION) 1603 return (IP_FW_DENY); 1604 if (((struct carp_header *)ulp)->carp_type != 1605 CARP_ADVERTISEMENT) 1606 return (IP_FW_DENY); 1607 break; 1608 1609 case IPPROTO_IPV6: /* RFC 2893 */ 1610 PULLUP_TO(hlen, ulp, struct ip6_hdr); 1611 break; 1612 1613 case IPPROTO_IPV4: /* RFC 2893 */ 1614 PULLUP_TO(hlen, ulp, struct ip); 1615 break; 1616 1617 default: 1618 if (V_fw_verbose) 1619 printf("IPFW2: IPV6 - Unknown " 1620 "Extension Header(%d), ext_hd=%x\n", 1621 proto, ext_hd); 1622 if (V_fw_deny_unknown_exthdrs) 1623 return (IP_FW_DENY); 1624 PULLUP_TO(hlen, ulp, struct ip6_ext); 1625 break; 1626 } /*switch */ 1627 } 1628 ip = mtod(m, struct ip *); 1629 ip6 = (struct ip6_hdr *)ip; 1630 args->f_id.src_ip6 = ip6->ip6_src; 1631 args->f_id.dst_ip6 = ip6->ip6_dst; 1632 args->f_id.src_ip = 0; 1633 args->f_id.dst_ip = 0; 1634 args->f_id.flow_id6 = ntohl(ip6->ip6_flow); 1635 iplen = ntohs(ip6->ip6_plen) + sizeof(*ip6); 1636 } else if (pktlen >= sizeof(struct ip) && 1637 (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) { 1638 is_ipv4 = 1; 1639 hlen = ip->ip_hl << 2; 1640 args->f_id.addr_type = 4; 1641 1642 /* 1643 * Collect parameters into local variables for faster matching. 1644 */ 1645 proto = ip->ip_p; 1646 src_ip = ip->ip_src; 1647 dst_ip = ip->ip_dst; 1648 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1649 iplen = ntohs(ip->ip_len); 1650 1651 if (offset == 0) { 1652 switch (proto) { 1653 case IPPROTO_TCP: 1654 PULLUP_TO(hlen, ulp, struct tcphdr); 1655 dst_port = TCP(ulp)->th_dport; 1656 src_port = TCP(ulp)->th_sport; 1657 /* save flags for dynamic rules */ 1658 args->f_id._flags = TCP(ulp)->th_flags; 1659 break; 1660 1661 case IPPROTO_SCTP: 1662 if (pktlen >= hlen + sizeof(struct sctphdr) + 1663 sizeof(struct sctp_chunkhdr) + 1664 offsetof(struct sctp_init, a_rwnd)) 1665 PULLUP_LEN(hlen, ulp, 1666 sizeof(struct sctphdr) + 1667 sizeof(struct sctp_chunkhdr) + 1668 offsetof(struct sctp_init, a_rwnd)); 1669 else if (pktlen >= hlen + sizeof(struct sctphdr)) 1670 PULLUP_LEN(hlen, ulp, pktlen - hlen); 1671 else 1672 PULLUP_LEN(hlen, ulp, 1673 sizeof(struct sctphdr)); 1674 src_port = SCTP(ulp)->src_port; 1675 dst_port = SCTP(ulp)->dest_port; 1676 break; 1677 1678 case IPPROTO_UDP: 1679 case IPPROTO_UDPLITE: 1680 PULLUP_TO(hlen, ulp, struct udphdr); 1681 dst_port = UDP(ulp)->uh_dport; 1682 src_port = UDP(ulp)->uh_sport; 1683 break; 1684 1685 case IPPROTO_ICMP: 1686 PULLUP_TO(hlen, ulp, struct icmphdr); 1687 //args->f_id.flags = ICMP(ulp)->icmp_type; 1688 break; 1689 1690 default: 1691 break; 1692 } 1693 } 1694 1695 ip = mtod(m, struct ip *); 1696 args->f_id.src_ip = ntohl(src_ip.s_addr); 1697 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1698 } 1699 #undef PULLUP_TO 1700 pktlen = iplen < pktlen ? iplen: pktlen; 1701 if (proto) { /* we may have port numbers, store them */ 1702 args->f_id.proto = proto; 1703 args->f_id.src_port = src_port = ntohs(src_port); 1704 args->f_id.dst_port = dst_port = ntohs(dst_port); 1705 } 1706 1707 IPFW_PF_RLOCK(chain); 1708 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ 1709 IPFW_PF_RUNLOCK(chain); 1710 return (IP_FW_PASS); /* accept */ 1711 } 1712 if (args->rule.slot) { 1713 /* 1714 * Packet has already been tagged as a result of a previous 1715 * match on rule args->rule aka args->rule_id (PIPE, QUEUE, 1716 * REASS, NETGRAPH, DIVERT/TEE...) 1717 * Validate the slot and continue from the next one 1718 * if still present, otherwise do a lookup. 1719 */ 1720 f_pos = (args->rule.chain_id == chain->id) ? 1721 args->rule.slot : 1722 ipfw_find_rule(chain, args->rule.rulenum, 1723 args->rule.rule_id); 1724 } else { 1725 f_pos = 0; 1726 } 1727 1728 /* 1729 * Now scan the rules, and parse microinstructions for each rule. 1730 * We have two nested loops and an inner switch. Sometimes we 1731 * need to break out of one or both loops, or re-enter one of 1732 * the loops with updated variables. Loop variables are: 1733 * 1734 * f_pos (outer loop) points to the current rule. 1735 * On output it points to the matching rule. 1736 * done (outer loop) is used as a flag to break the loop. 1737 * l (inner loop) residual length of current rule. 1738 * cmd points to the current microinstruction. 1739 * 1740 * We break the inner loop by setting l=0 and possibly 1741 * cmdlen=0 if we don't want to advance cmd. 1742 * We break the outer loop by setting done=1 1743 * We can restart the inner loop by setting l>0 and f_pos, f, cmd 1744 * as needed. 1745 */ 1746 for (; f_pos < chain->n_rules; f_pos++) { 1747 ipfw_insn *cmd; 1748 uint32_t tablearg = 0; 1749 int l, cmdlen, skip_or; /* skip rest of OR block */ 1750 struct ip_fw *f; 1751 1752 f = chain->map[f_pos]; 1753 if (V_set_disable & (1 << f->set) ) 1754 continue; 1755 1756 skip_or = 0; 1757 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 1758 l -= cmdlen, cmd += cmdlen) { 1759 int match; 1760 1761 /* 1762 * check_body is a jump target used when we find a 1763 * CHECK_STATE, and need to jump to the body of 1764 * the target rule. 1765 */ 1766 1767 /* check_body: */ 1768 cmdlen = F_LEN(cmd); 1769 /* 1770 * An OR block (insn_1 || .. || insn_n) has the 1771 * F_OR bit set in all but the last instruction. 1772 * The first match will set "skip_or", and cause 1773 * the following instructions to be skipped until 1774 * past the one with the F_OR bit clear. 1775 */ 1776 if (skip_or) { /* skip this instruction */ 1777 if ((cmd->len & F_OR) == 0) 1778 skip_or = 0; /* next one is good */ 1779 continue; 1780 } 1781 match = 0; /* set to 1 if we succeed */ 1782 1783 switch (cmd->opcode) { 1784 /* 1785 * The first set of opcodes compares the packet's 1786 * fields with some pattern, setting 'match' if a 1787 * match is found. At the end of the loop there is 1788 * logic to deal with F_NOT and F_OR flags associated 1789 * with the opcode. 1790 */ 1791 case O_NOP: 1792 match = 1; 1793 break; 1794 1795 case O_FORWARD_MAC: 1796 printf("ipfw: opcode %d unimplemented\n", 1797 cmd->opcode); 1798 break; 1799 1800 case O_GID: 1801 case O_UID: 1802 case O_JAIL: 1803 /* 1804 * We only check offset == 0 && proto != 0, 1805 * as this ensures that we have a 1806 * packet with the ports info. 1807 */ 1808 if (offset != 0) 1809 break; 1810 if (proto == IPPROTO_TCP || 1811 proto == IPPROTO_UDP || 1812 proto == IPPROTO_UDPLITE) 1813 match = check_uidgid( 1814 (ipfw_insn_u32 *)cmd, 1815 args, &ucred_lookup, 1816 #ifdef __FreeBSD__ 1817 &ucred_cache); 1818 #else 1819 (void *)&ucred_cache); 1820 #endif 1821 break; 1822 1823 case O_RECV: 1824 match = iface_match(m->m_pkthdr.rcvif, 1825 (ipfw_insn_if *)cmd, chain, &tablearg); 1826 break; 1827 1828 case O_XMIT: 1829 match = iface_match(oif, (ipfw_insn_if *)cmd, 1830 chain, &tablearg); 1831 break; 1832 1833 case O_VIA: 1834 match = iface_match(oif ? oif : 1835 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd, 1836 chain, &tablearg); 1837 break; 1838 1839 case O_MACADDR2: 1840 if (args->eh != NULL) { /* have MAC header */ 1841 u_int32_t *want = (u_int32_t *) 1842 ((ipfw_insn_mac *)cmd)->addr; 1843 u_int32_t *mask = (u_int32_t *) 1844 ((ipfw_insn_mac *)cmd)->mask; 1845 u_int32_t *hdr = (u_int32_t *)args->eh; 1846 1847 match = 1848 ( want[0] == (hdr[0] & mask[0]) && 1849 want[1] == (hdr[1] & mask[1]) && 1850 want[2] == (hdr[2] & mask[2]) ); 1851 } 1852 break; 1853 1854 case O_MAC_TYPE: 1855 if (args->eh != NULL) { 1856 u_int16_t *p = 1857 ((ipfw_insn_u16 *)cmd)->ports; 1858 int i; 1859 1860 for (i = cmdlen - 1; !match && i>0; 1861 i--, p += 2) 1862 match = (etype >= p[0] && 1863 etype <= p[1]); 1864 } 1865 break; 1866 1867 case O_FRAG: 1868 match = (offset != 0); 1869 break; 1870 1871 case O_IN: /* "out" is "not in" */ 1872 match = (oif == NULL); 1873 break; 1874 1875 case O_LAYER2: 1876 match = (args->eh != NULL); 1877 break; 1878 1879 case O_DIVERTED: 1880 { 1881 /* For diverted packets, args->rule.info 1882 * contains the divert port (in host format) 1883 * reason and direction. 1884 */ 1885 uint32_t i = args->rule.info; 1886 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT && 1887 cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2); 1888 } 1889 break; 1890 1891 case O_PROTO: 1892 /* 1893 * We do not allow an arg of 0 so the 1894 * check of "proto" only suffices. 1895 */ 1896 match = (proto == cmd->arg1); 1897 break; 1898 1899 case O_IP_SRC: 1900 match = is_ipv4 && 1901 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1902 src_ip.s_addr); 1903 break; 1904 1905 case O_IP_DST_LOOKUP: 1906 { 1907 void *pkey; 1908 uint32_t vidx, key; 1909 uint16_t keylen; 1910 1911 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { 1912 /* Determine lookup key type */ 1913 vidx = ((ipfw_insn_u32 *)cmd)->d[1]; 1914 if (vidx != 4 /* uid */ && 1915 vidx != 5 /* jail */ && 1916 is_ipv6 == 0 && is_ipv4 == 0) 1917 break; 1918 /* Determine key length */ 1919 if (vidx == 0 /* dst-ip */ || 1920 vidx == 1 /* src-ip */) 1921 keylen = is_ipv6 ? 1922 sizeof(struct in6_addr): 1923 sizeof(in_addr_t); 1924 else { 1925 keylen = sizeof(key); 1926 pkey = &key; 1927 } 1928 if (vidx == 0 /* dst-ip */) 1929 pkey = is_ipv4 ? (void *)&dst_ip: 1930 (void *)&args->f_id.dst_ip6; 1931 else if (vidx == 1 /* src-ip */) 1932 pkey = is_ipv4 ? (void *)&src_ip: 1933 (void *)&args->f_id.src_ip6; 1934 else if (vidx == 6 /* dscp */) { 1935 if (is_ipv4) 1936 key = ip->ip_tos >> 2; 1937 else { 1938 key = args->f_id.flow_id6; 1939 key = (key & 0x0f) << 2 | 1940 (key & 0xf000) >> 14; 1941 } 1942 key &= 0x3f; 1943 } else if (vidx == 2 /* dst-port */ || 1944 vidx == 3 /* src-port */) { 1945 /* Skip fragments */ 1946 if (offset != 0) 1947 break; 1948 /* Skip proto without ports */ 1949 if (proto != IPPROTO_TCP && 1950 proto != IPPROTO_UDP && 1951 proto != IPPROTO_UDPLITE && 1952 proto != IPPROTO_SCTP) 1953 break; 1954 if (vidx == 2 /* dst-port */) 1955 key = dst_port; 1956 else 1957 key = src_port; 1958 } 1959 #ifndef USERSPACE 1960 else if (vidx == 4 /* uid */ || 1961 vidx == 5 /* jail */) { 1962 check_uidgid( 1963 (ipfw_insn_u32 *)cmd, 1964 args, &ucred_lookup, 1965 #ifdef __FreeBSD__ 1966 &ucred_cache); 1967 if (vidx == 4 /* uid */) 1968 key = ucred_cache->cr_uid; 1969 else if (vidx == 5 /* jail */) 1970 key = ucred_cache->cr_prison->pr_id; 1971 #else /* !__FreeBSD__ */ 1972 (void *)&ucred_cache); 1973 if (vidx == 4 /* uid */) 1974 key = ucred_cache.uid; 1975 else if (vidx == 5 /* jail */) 1976 key = ucred_cache.xid; 1977 #endif /* !__FreeBSD__ */ 1978 } 1979 #endif /* !USERSPACE */ 1980 else 1981 break; 1982 match = ipfw_lookup_table(chain, 1983 cmd->arg1, keylen, pkey, &vidx); 1984 if (!match) 1985 break; 1986 tablearg = vidx; 1987 break; 1988 } 1989 /* cmdlen =< F_INSN_SIZE(ipfw_insn_u32) */ 1990 /* FALLTHROUGH */ 1991 } 1992 case O_IP_SRC_LOOKUP: 1993 { 1994 void *pkey; 1995 uint32_t vidx; 1996 uint16_t keylen; 1997 1998 if (is_ipv4) { 1999 keylen = sizeof(in_addr_t); 2000 if (cmd->opcode == O_IP_DST_LOOKUP) 2001 pkey = &dst_ip; 2002 else 2003 pkey = &src_ip; 2004 } else if (is_ipv6) { 2005 keylen = sizeof(struct in6_addr); 2006 if (cmd->opcode == O_IP_DST_LOOKUP) 2007 pkey = &args->f_id.dst_ip6; 2008 else 2009 pkey = &args->f_id.src_ip6; 2010 } else 2011 break; 2012 match = ipfw_lookup_table(chain, cmd->arg1, 2013 keylen, pkey, &vidx); 2014 if (!match) 2015 break; 2016 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) { 2017 match = ((ipfw_insn_u32 *)cmd)->d[0] == 2018 TARG_VAL(chain, vidx, tag); 2019 if (!match) 2020 break; 2021 } 2022 tablearg = vidx; 2023 break; 2024 } 2025 2026 case O_IP_FLOW_LOOKUP: 2027 { 2028 uint32_t v = 0; 2029 match = ipfw_lookup_table(chain, 2030 cmd->arg1, 0, &args->f_id, &v); 2031 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 2032 match = ((ipfw_insn_u32 *)cmd)->d[0] == 2033 TARG_VAL(chain, v, tag); 2034 if (match) 2035 tablearg = v; 2036 } 2037 break; 2038 case O_IP_SRC_MASK: 2039 case O_IP_DST_MASK: 2040 if (is_ipv4) { 2041 uint32_t a = 2042 (cmd->opcode == O_IP_DST_MASK) ? 2043 dst_ip.s_addr : src_ip.s_addr; 2044 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 2045 int i = cmdlen-1; 2046 2047 for (; !match && i>0; i-= 2, p+= 2) 2048 match = (p[0] == (a & p[1])); 2049 } 2050 break; 2051 2052 case O_IP_SRC_ME: 2053 if (is_ipv4) { 2054 match = in_localip(src_ip); 2055 break; 2056 } 2057 #ifdef INET6 2058 /* FALLTHROUGH */ 2059 case O_IP6_SRC_ME: 2060 match= is_ipv6 && ipfw_localip6(&args->f_id.src_ip6); 2061 #endif 2062 break; 2063 2064 case O_IP_DST_SET: 2065 case O_IP_SRC_SET: 2066 if (is_ipv4) { 2067 u_int32_t *d = (u_int32_t *)(cmd+1); 2068 u_int32_t addr = 2069 cmd->opcode == O_IP_DST_SET ? 2070 args->f_id.dst_ip : 2071 args->f_id.src_ip; 2072 2073 if (addr < d[0]) 2074 break; 2075 addr -= d[0]; /* subtract base */ 2076 match = (addr < cmd->arg1) && 2077 ( d[ 1 + (addr>>5)] & 2078 (1<<(addr & 0x1f)) ); 2079 } 2080 break; 2081 2082 case O_IP_DST: 2083 match = is_ipv4 && 2084 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2085 dst_ip.s_addr); 2086 break; 2087 2088 case O_IP_DST_ME: 2089 if (is_ipv4) { 2090 match = in_localip(dst_ip); 2091 break; 2092 } 2093 #ifdef INET6 2094 /* FALLTHROUGH */ 2095 case O_IP6_DST_ME: 2096 match= is_ipv6 && ipfw_localip6(&args->f_id.dst_ip6); 2097 #endif 2098 break; 2099 2100 2101 case O_IP_SRCPORT: 2102 case O_IP_DSTPORT: 2103 /* 2104 * offset == 0 && proto != 0 is enough 2105 * to guarantee that we have a 2106 * packet with port info. 2107 */ 2108 if ((proto == IPPROTO_UDP || 2109 proto == IPPROTO_UDPLITE || 2110 proto == IPPROTO_TCP || 2111 proto == IPPROTO_SCTP) && offset == 0) { 2112 u_int16_t x = 2113 (cmd->opcode == O_IP_SRCPORT) ? 2114 src_port : dst_port ; 2115 u_int16_t *p = 2116 ((ipfw_insn_u16 *)cmd)->ports; 2117 int i; 2118 2119 for (i = cmdlen - 1; !match && i>0; 2120 i--, p += 2) 2121 match = (x>=p[0] && x<=p[1]); 2122 } 2123 break; 2124 2125 case O_ICMPTYPE: 2126 match = (offset == 0 && proto==IPPROTO_ICMP && 2127 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 2128 break; 2129 2130 #ifdef INET6 2131 case O_ICMP6TYPE: 2132 match = is_ipv6 && offset == 0 && 2133 proto==IPPROTO_ICMPV6 && 2134 icmp6type_match( 2135 ICMP6(ulp)->icmp6_type, 2136 (ipfw_insn_u32 *)cmd); 2137 break; 2138 #endif /* INET6 */ 2139 2140 case O_IPOPT: 2141 match = (is_ipv4 && 2142 ipopts_match(ip, cmd) ); 2143 break; 2144 2145 case O_IPVER: 2146 match = (is_ipv4 && 2147 cmd->arg1 == ip->ip_v); 2148 break; 2149 2150 case O_IPID: 2151 case O_IPLEN: 2152 case O_IPTTL: 2153 if (is_ipv4) { /* only for IP packets */ 2154 uint16_t x; 2155 uint16_t *p; 2156 int i; 2157 2158 if (cmd->opcode == O_IPLEN) 2159 x = iplen; 2160 else if (cmd->opcode == O_IPTTL) 2161 x = ip->ip_ttl; 2162 else /* must be IPID */ 2163 x = ntohs(ip->ip_id); 2164 if (cmdlen == 1) { 2165 match = (cmd->arg1 == x); 2166 break; 2167 } 2168 /* otherwise we have ranges */ 2169 p = ((ipfw_insn_u16 *)cmd)->ports; 2170 i = cmdlen - 1; 2171 for (; !match && i>0; i--, p += 2) 2172 match = (x >= p[0] && x <= p[1]); 2173 } 2174 break; 2175 2176 case O_IPPRECEDENCE: 2177 match = (is_ipv4 && 2178 (cmd->arg1 == (ip->ip_tos & 0xe0)) ); 2179 break; 2180 2181 case O_IPTOS: 2182 match = (is_ipv4 && 2183 flags_match(cmd, ip->ip_tos)); 2184 break; 2185 2186 case O_DSCP: 2187 { 2188 uint32_t *p; 2189 uint16_t x; 2190 2191 p = ((ipfw_insn_u32 *)cmd)->d; 2192 2193 if (is_ipv4) 2194 x = ip->ip_tos >> 2; 2195 else if (is_ipv6) { 2196 uint8_t *v; 2197 v = &((struct ip6_hdr *)ip)->ip6_vfc; 2198 x = (*v & 0x0F) << 2; 2199 v++; 2200 x |= *v >> 6; 2201 } else 2202 break; 2203 2204 /* DSCP bitmask is stored as low_u32 high_u32 */ 2205 if (x >= 32) 2206 match = *(p + 1) & (1 << (x - 32)); 2207 else 2208 match = *p & (1 << x); 2209 } 2210 break; 2211 2212 case O_TCPDATALEN: 2213 if (proto == IPPROTO_TCP && offset == 0) { 2214 struct tcphdr *tcp; 2215 uint16_t x; 2216 uint16_t *p; 2217 int i; 2218 #ifdef INET6 2219 if (is_ipv6) { 2220 struct ip6_hdr *ip6; 2221 2222 ip6 = (struct ip6_hdr *)ip; 2223 if (ip6->ip6_plen == 0) { 2224 /* 2225 * Jumbo payload is not 2226 * supported by this 2227 * opcode. 2228 */ 2229 break; 2230 } 2231 x = iplen - hlen; 2232 } else 2233 #endif /* INET6 */ 2234 x = iplen - (ip->ip_hl << 2); 2235 tcp = TCP(ulp); 2236 x -= tcp->th_off << 2; 2237 if (cmdlen == 1) { 2238 match = (cmd->arg1 == x); 2239 break; 2240 } 2241 /* otherwise we have ranges */ 2242 p = ((ipfw_insn_u16 *)cmd)->ports; 2243 i = cmdlen - 1; 2244 for (; !match && i>0; i--, p += 2) 2245 match = (x >= p[0] && x <= p[1]); 2246 } 2247 break; 2248 2249 case O_TCPFLAGS: 2250 match = (proto == IPPROTO_TCP && offset == 0 && 2251 flags_match(cmd, TCP(ulp)->th_flags)); 2252 break; 2253 2254 case O_TCPOPTS: 2255 if (proto == IPPROTO_TCP && offset == 0 && ulp){ 2256 PULLUP_LEN(hlen, ulp, 2257 (TCP(ulp)->th_off << 2)); 2258 match = tcpopts_match(TCP(ulp), cmd); 2259 } 2260 break; 2261 2262 case O_TCPSEQ: 2263 match = (proto == IPPROTO_TCP && offset == 0 && 2264 ((ipfw_insn_u32 *)cmd)->d[0] == 2265 TCP(ulp)->th_seq); 2266 break; 2267 2268 case O_TCPACK: 2269 match = (proto == IPPROTO_TCP && offset == 0 && 2270 ((ipfw_insn_u32 *)cmd)->d[0] == 2271 TCP(ulp)->th_ack); 2272 break; 2273 2274 case O_TCPWIN: 2275 if (proto == IPPROTO_TCP && offset == 0) { 2276 uint16_t x; 2277 uint16_t *p; 2278 int i; 2279 2280 x = ntohs(TCP(ulp)->th_win); 2281 if (cmdlen == 1) { 2282 match = (cmd->arg1 == x); 2283 break; 2284 } 2285 /* Otherwise we have ranges. */ 2286 p = ((ipfw_insn_u16 *)cmd)->ports; 2287 i = cmdlen - 1; 2288 for (; !match && i > 0; i--, p += 2) 2289 match = (x >= p[0] && x <= p[1]); 2290 } 2291 break; 2292 2293 case O_ESTAB: 2294 /* reject packets which have SYN only */ 2295 /* XXX should i also check for TH_ACK ? */ 2296 match = (proto == IPPROTO_TCP && offset == 0 && 2297 (TCP(ulp)->th_flags & 2298 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 2299 break; 2300 2301 case O_ALTQ: { 2302 struct pf_mtag *at; 2303 struct m_tag *mtag; 2304 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 2305 2306 /* 2307 * ALTQ uses mbuf tags from another 2308 * packet filtering system - pf(4). 2309 * We allocate a tag in its format 2310 * and fill it in, pretending to be pf(4). 2311 */ 2312 match = 1; 2313 at = pf_find_mtag(m); 2314 if (at != NULL && at->qid != 0) 2315 break; 2316 mtag = m_tag_get(PACKET_TAG_PF, 2317 sizeof(struct pf_mtag), M_NOWAIT | M_ZERO); 2318 if (mtag == NULL) { 2319 /* 2320 * Let the packet fall back to the 2321 * default ALTQ. 2322 */ 2323 break; 2324 } 2325 m_tag_prepend(m, mtag); 2326 at = (struct pf_mtag *)(mtag + 1); 2327 at->qid = altq->qid; 2328 at->hdr = ip; 2329 break; 2330 } 2331 2332 case O_LOG: 2333 ipfw_log(chain, f, hlen, args, m, 2334 oif, offset | ip6f_mf, tablearg, ip); 2335 match = 1; 2336 break; 2337 2338 case O_PROB: 2339 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 2340 break; 2341 2342 case O_VERREVPATH: 2343 /* Outgoing packets automatically pass/match */ 2344 match = ((oif != NULL) || 2345 (m->m_pkthdr.rcvif == NULL) || 2346 ( 2347 #ifdef INET6 2348 is_ipv6 ? 2349 verify_path6(&(args->f_id.src_ip6), 2350 m->m_pkthdr.rcvif, args->f_id.fib) : 2351 #endif 2352 verify_path(src_ip, m->m_pkthdr.rcvif, 2353 args->f_id.fib))); 2354 break; 2355 2356 case O_VERSRCREACH: 2357 /* Outgoing packets automatically pass/match */ 2358 match = (hlen > 0 && ((oif != NULL) || 2359 #ifdef INET6 2360 is_ipv6 ? 2361 verify_path6(&(args->f_id.src_ip6), 2362 NULL, args->f_id.fib) : 2363 #endif 2364 verify_path(src_ip, NULL, args->f_id.fib))); 2365 break; 2366 2367 case O_ANTISPOOF: 2368 /* Outgoing packets automatically pass/match */ 2369 if (oif == NULL && hlen > 0 && 2370 ( (is_ipv4 && in_localaddr(src_ip)) 2371 #ifdef INET6 2372 || (is_ipv6 && 2373 in6_localaddr(&(args->f_id.src_ip6))) 2374 #endif 2375 )) 2376 match = 2377 #ifdef INET6 2378 is_ipv6 ? verify_path6( 2379 &(args->f_id.src_ip6), 2380 m->m_pkthdr.rcvif, 2381 args->f_id.fib) : 2382 #endif 2383 verify_path(src_ip, 2384 m->m_pkthdr.rcvif, 2385 args->f_id.fib); 2386 else 2387 match = 1; 2388 break; 2389 2390 case O_IPSEC: 2391 match = (m_tag_find(m, 2392 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 2393 /* otherwise no match */ 2394 break; 2395 2396 #ifdef INET6 2397 case O_IP6_SRC: 2398 match = is_ipv6 && 2399 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 2400 &((ipfw_insn_ip6 *)cmd)->addr6); 2401 break; 2402 2403 case O_IP6_DST: 2404 match = is_ipv6 && 2405 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 2406 &((ipfw_insn_ip6 *)cmd)->addr6); 2407 break; 2408 case O_IP6_SRC_MASK: 2409 case O_IP6_DST_MASK: 2410 if (is_ipv6) { 2411 int i = cmdlen - 1; 2412 struct in6_addr p; 2413 struct in6_addr *d = 2414 &((ipfw_insn_ip6 *)cmd)->addr6; 2415 2416 for (; !match && i > 0; d += 2, 2417 i -= F_INSN_SIZE(struct in6_addr) 2418 * 2) { 2419 p = (cmd->opcode == 2420 O_IP6_SRC_MASK) ? 2421 args->f_id.src_ip6: 2422 args->f_id.dst_ip6; 2423 APPLY_MASK(&p, &d[1]); 2424 match = 2425 IN6_ARE_ADDR_EQUAL(&d[0], 2426 &p); 2427 } 2428 } 2429 break; 2430 2431 case O_FLOW6ID: 2432 match = is_ipv6 && 2433 flow6id_match(args->f_id.flow_id6, 2434 (ipfw_insn_u32 *) cmd); 2435 break; 2436 2437 case O_EXT_HDR: 2438 match = is_ipv6 && 2439 (ext_hd & ((ipfw_insn *) cmd)->arg1); 2440 break; 2441 2442 case O_IP6: 2443 match = is_ipv6; 2444 break; 2445 #endif 2446 2447 case O_IP4: 2448 match = is_ipv4; 2449 break; 2450 2451 case O_TAG: { 2452 struct m_tag *mtag; 2453 uint32_t tag = TARG(cmd->arg1, tag); 2454 2455 /* Packet is already tagged with this tag? */ 2456 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 2457 2458 /* We have `untag' action when F_NOT flag is 2459 * present. And we must remove this mtag from 2460 * mbuf and reset `match' to zero (`match' will 2461 * be inversed later). 2462 * Otherwise we should allocate new mtag and 2463 * push it into mbuf. 2464 */ 2465 if (cmd->len & F_NOT) { /* `untag' action */ 2466 if (mtag != NULL) 2467 m_tag_delete(m, mtag); 2468 match = 0; 2469 } else { 2470 if (mtag == NULL) { 2471 mtag = m_tag_alloc( MTAG_IPFW, 2472 tag, 0, M_NOWAIT); 2473 if (mtag != NULL) 2474 m_tag_prepend(m, mtag); 2475 } 2476 match = 1; 2477 } 2478 break; 2479 } 2480 2481 case O_FIB: /* try match the specified fib */ 2482 if (args->f_id.fib == cmd->arg1) 2483 match = 1; 2484 break; 2485 2486 case O_SOCKARG: { 2487 #ifndef USERSPACE /* not supported in userspace */ 2488 struct inpcb *inp = args->inp; 2489 struct inpcbinfo *pi; 2490 2491 if (is_ipv6) /* XXX can we remove this ? */ 2492 break; 2493 2494 if (proto == IPPROTO_TCP) 2495 pi = &V_tcbinfo; 2496 else if (proto == IPPROTO_UDP) 2497 pi = &V_udbinfo; 2498 else if (proto == IPPROTO_UDPLITE) 2499 pi = &V_ulitecbinfo; 2500 else 2501 break; 2502 2503 /* 2504 * XXXRW: so_user_cookie should almost 2505 * certainly be inp_user_cookie? 2506 */ 2507 2508 /* For incoming packet, lookup up the 2509 inpcb using the src/dest ip/port tuple */ 2510 if (inp == NULL) { 2511 inp = in_pcblookup(pi, 2512 src_ip, htons(src_port), 2513 dst_ip, htons(dst_port), 2514 INPLOOKUP_RLOCKPCB, NULL); 2515 if (inp != NULL) { 2516 tablearg = 2517 inp->inp_socket->so_user_cookie; 2518 if (tablearg) 2519 match = 1; 2520 INP_RUNLOCK(inp); 2521 } 2522 } else { 2523 if (inp->inp_socket) { 2524 tablearg = 2525 inp->inp_socket->so_user_cookie; 2526 if (tablearg) 2527 match = 1; 2528 } 2529 } 2530 #endif /* !USERSPACE */ 2531 break; 2532 } 2533 2534 case O_TAGGED: { 2535 struct m_tag *mtag; 2536 uint32_t tag = TARG(cmd->arg1, tag); 2537 2538 if (cmdlen == 1) { 2539 match = m_tag_locate(m, MTAG_IPFW, 2540 tag, NULL) != NULL; 2541 break; 2542 } 2543 2544 /* we have ranges */ 2545 for (mtag = m_tag_first(m); 2546 mtag != NULL && !match; 2547 mtag = m_tag_next(m, mtag)) { 2548 uint16_t *p; 2549 int i; 2550 2551 if (mtag->m_tag_cookie != MTAG_IPFW) 2552 continue; 2553 2554 p = ((ipfw_insn_u16 *)cmd)->ports; 2555 i = cmdlen - 1; 2556 for(; !match && i > 0; i--, p += 2) 2557 match = 2558 mtag->m_tag_id >= p[0] && 2559 mtag->m_tag_id <= p[1]; 2560 } 2561 break; 2562 } 2563 2564 /* 2565 * The second set of opcodes represents 'actions', 2566 * i.e. the terminal part of a rule once the packet 2567 * matches all previous patterns. 2568 * Typically there is only one action for each rule, 2569 * and the opcode is stored at the end of the rule 2570 * (but there are exceptions -- see below). 2571 * 2572 * In general, here we set retval and terminate the 2573 * outer loop (would be a 'break 3' in some language, 2574 * but we need to set l=0, done=1) 2575 * 2576 * Exceptions: 2577 * O_COUNT and O_SKIPTO actions: 2578 * instead of terminating, we jump to the next rule 2579 * (setting l=0), or to the SKIPTO target (setting 2580 * f/f_len, cmd and l as needed), respectively. 2581 * 2582 * O_TAG, O_LOG and O_ALTQ action parameters: 2583 * perform some action and set match = 1; 2584 * 2585 * O_LIMIT and O_KEEP_STATE: these opcodes are 2586 * not real 'actions', and are stored right 2587 * before the 'action' part of the rule. 2588 * These opcodes try to install an entry in the 2589 * state tables; if successful, we continue with 2590 * the next opcode (match=1; break;), otherwise 2591 * the packet must be dropped (set retval, 2592 * break loops with l=0, done=1) 2593 * 2594 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2595 * cause a lookup of the state table, and a jump 2596 * to the 'action' part of the parent rule 2597 * if an entry is found, or 2598 * (CHECK_STATE only) a jump to the next rule if 2599 * the entry is not found. 2600 * The result of the lookup is cached so that 2601 * further instances of these opcodes become NOPs. 2602 * The jump to the next rule is done by setting 2603 * l=0, cmdlen=0. 2604 */ 2605 case O_LIMIT: 2606 case O_KEEP_STATE: 2607 if (ipfw_dyn_install_state(chain, f, 2608 (ipfw_insn_limit *)cmd, args, ulp, 2609 pktlen, &dyn_info, tablearg)) { 2610 /* error or limit violation */ 2611 retval = IP_FW_DENY; 2612 l = 0; /* exit inner loop */ 2613 done = 1; /* exit outer loop */ 2614 } 2615 match = 1; 2616 break; 2617 2618 case O_PROBE_STATE: 2619 case O_CHECK_STATE: 2620 /* 2621 * dynamic rules are checked at the first 2622 * keep-state or check-state occurrence, 2623 * with the result being stored in dyn_info. 2624 * The compiler introduces a PROBE_STATE 2625 * instruction for us when we have a 2626 * KEEP_STATE (because PROBE_STATE needs 2627 * to be run first). 2628 */ 2629 if (DYN_LOOKUP_NEEDED(&dyn_info, cmd) && 2630 (q = ipfw_dyn_lookup_state(args, ulp, 2631 pktlen, cmd, &dyn_info)) != NULL) { 2632 /* 2633 * Found dynamic entry, jump to the 2634 * 'action' part of the parent rule 2635 * by setting f, cmd, l and clearing 2636 * cmdlen. 2637 */ 2638 f = q; 2639 f_pos = dyn_info.f_pos; 2640 cmd = ACTION_PTR(f); 2641 l = f->cmd_len - f->act_ofs; 2642 cmdlen = 0; 2643 match = 1; 2644 break; 2645 } 2646 /* 2647 * Dynamic entry not found. If CHECK_STATE, 2648 * skip to next rule, if PROBE_STATE just 2649 * ignore and continue with next opcode. 2650 */ 2651 if (cmd->opcode == O_CHECK_STATE) 2652 l = 0; /* exit inner loop */ 2653 match = 1; 2654 break; 2655 2656 case O_ACCEPT: 2657 retval = 0; /* accept */ 2658 l = 0; /* exit inner loop */ 2659 done = 1; /* exit outer loop */ 2660 break; 2661 2662 case O_PIPE: 2663 case O_QUEUE: 2664 set_match(args, f_pos, chain); 2665 args->rule.info = TARG(cmd->arg1, pipe); 2666 if (cmd->opcode == O_PIPE) 2667 args->rule.info |= IPFW_IS_PIPE; 2668 if (V_fw_one_pass) 2669 args->rule.info |= IPFW_ONEPASS; 2670 retval = IP_FW_DUMMYNET; 2671 l = 0; /* exit inner loop */ 2672 done = 1; /* exit outer loop */ 2673 break; 2674 2675 case O_DIVERT: 2676 case O_TEE: 2677 if (args->eh) /* not on layer 2 */ 2678 break; 2679 /* otherwise this is terminal */ 2680 l = 0; /* exit inner loop */ 2681 done = 1; /* exit outer loop */ 2682 retval = (cmd->opcode == O_DIVERT) ? 2683 IP_FW_DIVERT : IP_FW_TEE; 2684 set_match(args, f_pos, chain); 2685 args->rule.info = TARG(cmd->arg1, divert); 2686 break; 2687 2688 case O_COUNT: 2689 IPFW_INC_RULE_COUNTER(f, pktlen); 2690 l = 0; /* exit inner loop */ 2691 break; 2692 2693 case O_SKIPTO: 2694 IPFW_INC_RULE_COUNTER(f, pktlen); 2695 f_pos = JUMP(chain, f, cmd->arg1, tablearg, 0); 2696 /* 2697 * Skip disabled rules, and re-enter 2698 * the inner loop with the correct 2699 * f_pos, f, l and cmd. 2700 * Also clear cmdlen and skip_or 2701 */ 2702 for (; f_pos < chain->n_rules - 1 && 2703 (V_set_disable & 2704 (1 << chain->map[f_pos]->set)); 2705 f_pos++) 2706 ; 2707 /* Re-enter the inner loop at the skipto rule. */ 2708 f = chain->map[f_pos]; 2709 l = f->cmd_len; 2710 cmd = f->cmd; 2711 match = 1; 2712 cmdlen = 0; 2713 skip_or = 0; 2714 continue; 2715 break; /* not reached */ 2716 2717 case O_CALLRETURN: { 2718 /* 2719 * Implementation of `subroutine' call/return, 2720 * in the stack carried in an mbuf tag. This 2721 * is different from `skipto' in that any call 2722 * address is possible (`skipto' must prevent 2723 * backward jumps to avoid endless loops). 2724 * We have `return' action when F_NOT flag is 2725 * present. The `m_tag_id' field is used as 2726 * stack pointer. 2727 */ 2728 struct m_tag *mtag; 2729 uint16_t jmpto, *stack; 2730 2731 #define IS_CALL ((cmd->len & F_NOT) == 0) 2732 #define IS_RETURN ((cmd->len & F_NOT) != 0) 2733 /* 2734 * Hand-rolled version of m_tag_locate() with 2735 * wildcard `type'. 2736 * If not already tagged, allocate new tag. 2737 */ 2738 mtag = m_tag_first(m); 2739 while (mtag != NULL) { 2740 if (mtag->m_tag_cookie == 2741 MTAG_IPFW_CALL) 2742 break; 2743 mtag = m_tag_next(m, mtag); 2744 } 2745 if (mtag == NULL && IS_CALL) { 2746 mtag = m_tag_alloc(MTAG_IPFW_CALL, 0, 2747 IPFW_CALLSTACK_SIZE * 2748 sizeof(uint16_t), M_NOWAIT); 2749 if (mtag != NULL) 2750 m_tag_prepend(m, mtag); 2751 } 2752 2753 /* 2754 * On error both `call' and `return' just 2755 * continue with next rule. 2756 */ 2757 if (IS_RETURN && (mtag == NULL || 2758 mtag->m_tag_id == 0)) { 2759 l = 0; /* exit inner loop */ 2760 break; 2761 } 2762 if (IS_CALL && (mtag == NULL || 2763 mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) { 2764 printf("ipfw: call stack error, " 2765 "go to next rule\n"); 2766 l = 0; /* exit inner loop */ 2767 break; 2768 } 2769 2770 IPFW_INC_RULE_COUNTER(f, pktlen); 2771 stack = (uint16_t *)(mtag + 1); 2772 2773 /* 2774 * The `call' action may use cached f_pos 2775 * (in f->next_rule), whose version is written 2776 * in f->next_rule. 2777 * The `return' action, however, doesn't have 2778 * fixed jump address in cmd->arg1 and can't use 2779 * cache. 2780 */ 2781 if (IS_CALL) { 2782 stack[mtag->m_tag_id] = f->rulenum; 2783 mtag->m_tag_id++; 2784 f_pos = JUMP(chain, f, cmd->arg1, 2785 tablearg, 1); 2786 } else { /* `return' action */ 2787 mtag->m_tag_id--; 2788 jmpto = stack[mtag->m_tag_id] + 1; 2789 f_pos = ipfw_find_rule(chain, jmpto, 0); 2790 } 2791 2792 /* 2793 * Skip disabled rules, and re-enter 2794 * the inner loop with the correct 2795 * f_pos, f, l and cmd. 2796 * Also clear cmdlen and skip_or 2797 */ 2798 for (; f_pos < chain->n_rules - 1 && 2799 (V_set_disable & 2800 (1 << chain->map[f_pos]->set)); f_pos++) 2801 ; 2802 /* Re-enter the inner loop at the dest rule. */ 2803 f = chain->map[f_pos]; 2804 l = f->cmd_len; 2805 cmd = f->cmd; 2806 cmdlen = 0; 2807 skip_or = 0; 2808 continue; 2809 break; /* NOTREACHED */ 2810 } 2811 #undef IS_CALL 2812 #undef IS_RETURN 2813 2814 case O_REJECT: 2815 /* 2816 * Drop the packet and send a reject notice 2817 * if the packet is not ICMP (or is an ICMP 2818 * query), and it is not multicast/broadcast. 2819 */ 2820 if (hlen > 0 && is_ipv4 && offset == 0 && 2821 (proto != IPPROTO_ICMP || 2822 is_icmp_query(ICMP(ulp))) && 2823 !(m->m_flags & (M_BCAST|M_MCAST)) && 2824 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 2825 send_reject(args, cmd->arg1, iplen, ip); 2826 m = args->m; 2827 } 2828 /* FALLTHROUGH */ 2829 #ifdef INET6 2830 case O_UNREACH6: 2831 if (hlen > 0 && is_ipv6 && 2832 ((offset & IP6F_OFF_MASK) == 0) && 2833 (proto != IPPROTO_ICMPV6 || 2834 (is_icmp6_query(icmp6_type) == 1)) && 2835 !(m->m_flags & (M_BCAST|M_MCAST)) && 2836 !IN6_IS_ADDR_MULTICAST( 2837 &args->f_id.dst_ip6)) { 2838 send_reject6(args, 2839 cmd->opcode == O_REJECT ? 2840 map_icmp_unreach(cmd->arg1): 2841 cmd->arg1, hlen, 2842 (struct ip6_hdr *)ip); 2843 m = args->m; 2844 } 2845 /* FALLTHROUGH */ 2846 #endif 2847 case O_DENY: 2848 retval = IP_FW_DENY; 2849 l = 0; /* exit inner loop */ 2850 done = 1; /* exit outer loop */ 2851 break; 2852 2853 case O_FORWARD_IP: 2854 if (args->eh) /* not valid on layer2 pkts */ 2855 break; 2856 if (q != f || 2857 dyn_info.direction == MATCH_FORWARD) { 2858 struct sockaddr_in *sa; 2859 2860 sa = &(((ipfw_insn_sa *)cmd)->sa); 2861 if (sa->sin_addr.s_addr == INADDR_ANY) { 2862 #ifdef INET6 2863 /* 2864 * We use O_FORWARD_IP opcode for 2865 * fwd rule with tablearg, but tables 2866 * now support IPv6 addresses. And 2867 * when we are inspecting IPv6 packet, 2868 * we can use nh6 field from 2869 * table_value as next_hop6 address. 2870 */ 2871 if (is_ipv6) { 2872 struct sockaddr_in6 *sa6; 2873 2874 sa6 = args->next_hop6 = 2875 &args->hopstore6; 2876 sa6->sin6_family = AF_INET6; 2877 sa6->sin6_len = sizeof(*sa6); 2878 sa6->sin6_addr = TARG_VAL( 2879 chain, tablearg, nh6); 2880 sa6->sin6_port = sa->sin_port; 2881 /* 2882 * Set sin6_scope_id only for 2883 * link-local unicast addresses. 2884 */ 2885 if (IN6_IS_ADDR_LINKLOCAL( 2886 &sa6->sin6_addr)) 2887 sa6->sin6_scope_id = 2888 TARG_VAL(chain, 2889 tablearg, 2890 zoneid); 2891 } else 2892 #endif 2893 { 2894 args->hopstore.sin_port = 2895 sa->sin_port; 2896 sa = args->next_hop = 2897 &args->hopstore; 2898 sa->sin_family = AF_INET; 2899 sa->sin_len = sizeof(*sa); 2900 sa->sin_addr.s_addr = htonl( 2901 TARG_VAL(chain, tablearg, 2902 nh4)); 2903 } 2904 } else { 2905 args->next_hop = sa; 2906 } 2907 } 2908 retval = IP_FW_PASS; 2909 l = 0; /* exit inner loop */ 2910 done = 1; /* exit outer loop */ 2911 break; 2912 2913 #ifdef INET6 2914 case O_FORWARD_IP6: 2915 if (args->eh) /* not valid on layer2 pkts */ 2916 break; 2917 if (q != f || 2918 dyn_info.direction == MATCH_FORWARD) { 2919 struct sockaddr_in6 *sin6; 2920 2921 sin6 = &(((ipfw_insn_sa6 *)cmd)->sa); 2922 args->next_hop6 = sin6; 2923 } 2924 retval = IP_FW_PASS; 2925 l = 0; /* exit inner loop */ 2926 done = 1; /* exit outer loop */ 2927 break; 2928 #endif 2929 2930 case O_NETGRAPH: 2931 case O_NGTEE: 2932 set_match(args, f_pos, chain); 2933 args->rule.info = TARG(cmd->arg1, netgraph); 2934 if (V_fw_one_pass) 2935 args->rule.info |= IPFW_ONEPASS; 2936 retval = (cmd->opcode == O_NETGRAPH) ? 2937 IP_FW_NETGRAPH : IP_FW_NGTEE; 2938 l = 0; /* exit inner loop */ 2939 done = 1; /* exit outer loop */ 2940 break; 2941 2942 case O_SETFIB: { 2943 uint32_t fib; 2944 2945 IPFW_INC_RULE_COUNTER(f, pktlen); 2946 fib = TARG(cmd->arg1, fib) & 0x7FFF; 2947 if (fib >= rt_numfibs) 2948 fib = 0; 2949 M_SETFIB(m, fib); 2950 args->f_id.fib = fib; 2951 l = 0; /* exit inner loop */ 2952 break; 2953 } 2954 2955 case O_SETDSCP: { 2956 uint16_t code; 2957 2958 code = TARG(cmd->arg1, dscp) & 0x3F; 2959 l = 0; /* exit inner loop */ 2960 if (is_ipv4) { 2961 uint16_t old; 2962 2963 old = *(uint16_t *)ip; 2964 ip->ip_tos = (code << 2) | 2965 (ip->ip_tos & 0x03); 2966 ip->ip_sum = cksum_adjust(ip->ip_sum, 2967 old, *(uint16_t *)ip); 2968 } else if (is_ipv6) { 2969 uint8_t *v; 2970 2971 v = &((struct ip6_hdr *)ip)->ip6_vfc; 2972 *v = (*v & 0xF0) | (code >> 2); 2973 v++; 2974 *v = (*v & 0x3F) | ((code & 0x03) << 6); 2975 } else 2976 break; 2977 2978 IPFW_INC_RULE_COUNTER(f, pktlen); 2979 break; 2980 } 2981 2982 case O_NAT: 2983 l = 0; /* exit inner loop */ 2984 done = 1; /* exit outer loop */ 2985 /* 2986 * Ensure that we do not invoke NAT handler for 2987 * non IPv4 packets. Libalias expects only IPv4. 2988 */ 2989 if (!is_ipv4 || !IPFW_NAT_LOADED) { 2990 retval = IP_FW_DENY; 2991 break; 2992 } 2993 2994 struct cfg_nat *t; 2995 int nat_id; 2996 2997 set_match(args, f_pos, chain); 2998 /* Check if this is 'global' nat rule */ 2999 if (cmd->arg1 == IP_FW_NAT44_GLOBAL) { 3000 retval = ipfw_nat_ptr(args, NULL, m); 3001 break; 3002 } 3003 t = ((ipfw_insn_nat *)cmd)->nat; 3004 if (t == NULL) { 3005 nat_id = TARG(cmd->arg1, nat); 3006 t = (*lookup_nat_ptr)(&chain->nat, nat_id); 3007 3008 if (t == NULL) { 3009 retval = IP_FW_DENY; 3010 break; 3011 } 3012 if (cmd->arg1 != IP_FW_TARG) 3013 ((ipfw_insn_nat *)cmd)->nat = t; 3014 } 3015 retval = ipfw_nat_ptr(args, t, m); 3016 break; 3017 3018 case O_REASS: { 3019 int ip_off; 3020 3021 l = 0; /* in any case exit inner loop */ 3022 if (is_ipv6) /* IPv6 is not supported yet */ 3023 break; 3024 IPFW_INC_RULE_COUNTER(f, pktlen); 3025 ip_off = ntohs(ip->ip_off); 3026 3027 /* if not fragmented, go to next rule */ 3028 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0) 3029 break; 3030 3031 args->m = m = ip_reass(m); 3032 3033 /* 3034 * do IP header checksum fixup. 3035 */ 3036 if (m == NULL) { /* fragment got swallowed */ 3037 retval = IP_FW_DENY; 3038 } else { /* good, packet complete */ 3039 int hlen; 3040 3041 ip = mtod(m, struct ip *); 3042 hlen = ip->ip_hl << 2; 3043 ip->ip_sum = 0; 3044 if (hlen == sizeof(struct ip)) 3045 ip->ip_sum = in_cksum_hdr(ip); 3046 else 3047 ip->ip_sum = in_cksum(m, hlen); 3048 retval = IP_FW_REASS; 3049 set_match(args, f_pos, chain); 3050 } 3051 done = 1; /* exit outer loop */ 3052 break; 3053 } 3054 case O_EXTERNAL_ACTION: 3055 l = 0; /* in any case exit inner loop */ 3056 retval = ipfw_run_eaction(chain, args, 3057 cmd, &done); 3058 /* 3059 * If both @retval and @done are zero, 3060 * consider this as rule matching and 3061 * update counters. 3062 */ 3063 if (retval == 0 && done == 0) { 3064 IPFW_INC_RULE_COUNTER(f, pktlen); 3065 /* 3066 * Reset the result of the last 3067 * dynamic state lookup. 3068 * External action can change 3069 * @args content, and it may be 3070 * used for new state lookup later. 3071 */ 3072 DYN_INFO_INIT(&dyn_info); 3073 } 3074 break; 3075 3076 default: 3077 panic("-- unknown opcode %d\n", cmd->opcode); 3078 } /* end of switch() on opcodes */ 3079 /* 3080 * if we get here with l=0, then match is irrelevant. 3081 */ 3082 3083 if (cmd->len & F_NOT) 3084 match = !match; 3085 3086 if (match) { 3087 if (cmd->len & F_OR) 3088 skip_or = 1; 3089 } else { 3090 if (!(cmd->len & F_OR)) /* not an OR block, */ 3091 break; /* try next rule */ 3092 } 3093 3094 } /* end of inner loop, scan opcodes */ 3095 #undef PULLUP_LEN 3096 3097 if (done) 3098 break; 3099 3100 /* next_rule:; */ /* try next rule */ 3101 3102 } /* end of outer for, scan rules */ 3103 3104 if (done) { 3105 struct ip_fw *rule = chain->map[f_pos]; 3106 /* Update statistics */ 3107 IPFW_INC_RULE_COUNTER(rule, pktlen); 3108 } else { 3109 retval = IP_FW_DENY; 3110 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 3111 } 3112 IPFW_PF_RUNLOCK(chain); 3113 #ifdef __FreeBSD__ 3114 if (ucred_cache != NULL) 3115 crfree(ucred_cache); 3116 #endif 3117 return (retval); 3118 3119 pullup_failed: 3120 if (V_fw_verbose) 3121 printf("ipfw: pullup failed\n"); 3122 return (IP_FW_DENY); 3123 } 3124 3125 /* 3126 * Set maximum number of tables that can be used in given VNET ipfw instance. 3127 */ 3128 #ifdef SYSCTL_NODE 3129 static int 3130 sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS) 3131 { 3132 int error; 3133 unsigned int ntables; 3134 3135 ntables = V_fw_tables_max; 3136 3137 error = sysctl_handle_int(oidp, &ntables, 0, req); 3138 /* Read operation or some error */ 3139 if ((error != 0) || (req->newptr == NULL)) 3140 return (error); 3141 3142 return (ipfw_resize_tables(&V_layer3_chain, ntables)); 3143 } 3144 3145 /* 3146 * Switches table namespace between global and per-set. 3147 */ 3148 static int 3149 sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS) 3150 { 3151 int error; 3152 unsigned int sets; 3153 3154 sets = V_fw_tables_sets; 3155 3156 error = sysctl_handle_int(oidp, &sets, 0, req); 3157 /* Read operation or some error */ 3158 if ((error != 0) || (req->newptr == NULL)) 3159 return (error); 3160 3161 return (ipfw_switch_tables_namespace(&V_layer3_chain, sets)); 3162 } 3163 #endif 3164 3165 /* 3166 * Module and VNET glue 3167 */ 3168 3169 /* 3170 * Stuff that must be initialised only on boot or module load 3171 */ 3172 static int 3173 ipfw_init(void) 3174 { 3175 int error = 0; 3176 3177 /* 3178 * Only print out this stuff the first time around, 3179 * when called from the sysinit code. 3180 */ 3181 printf("ipfw2 " 3182 #ifdef INET6 3183 "(+ipv6) " 3184 #endif 3185 "initialized, divert %s, nat %s, " 3186 "default to %s, logging ", 3187 #ifdef IPDIVERT 3188 "enabled", 3189 #else 3190 "loadable", 3191 #endif 3192 #ifdef IPFIREWALL_NAT 3193 "enabled", 3194 #else 3195 "loadable", 3196 #endif 3197 default_to_accept ? "accept" : "deny"); 3198 3199 /* 3200 * Note: V_xxx variables can be accessed here but the vnet specific 3201 * initializer may not have been called yet for the VIMAGE case. 3202 * Tuneables will have been processed. We will print out values for 3203 * the default vnet. 3204 * XXX This should all be rationalized AFTER 8.0 3205 */ 3206 if (V_fw_verbose == 0) 3207 printf("disabled\n"); 3208 else if (V_verbose_limit == 0) 3209 printf("unlimited\n"); 3210 else 3211 printf("limited to %d packets/entry by default\n", 3212 V_verbose_limit); 3213 3214 /* Check user-supplied table count for validness */ 3215 if (default_fw_tables > IPFW_TABLES_MAX) 3216 default_fw_tables = IPFW_TABLES_MAX; 3217 3218 ipfw_init_sopt_handler(); 3219 ipfw_init_obj_rewriter(); 3220 ipfw_iface_init(); 3221 return (error); 3222 } 3223 3224 /* 3225 * Called for the removal of the last instance only on module unload. 3226 */ 3227 static void 3228 ipfw_destroy(void) 3229 { 3230 3231 ipfw_iface_destroy(); 3232 ipfw_destroy_sopt_handler(); 3233 ipfw_destroy_obj_rewriter(); 3234 printf("IP firewall unloaded\n"); 3235 } 3236 3237 /* 3238 * Stuff that must be initialized for every instance 3239 * (including the first of course). 3240 */ 3241 static int 3242 vnet_ipfw_init(const void *unused) 3243 { 3244 int error, first; 3245 struct ip_fw *rule = NULL; 3246 struct ip_fw_chain *chain; 3247 3248 chain = &V_layer3_chain; 3249 3250 first = IS_DEFAULT_VNET(curvnet) ? 1 : 0; 3251 3252 /* First set up some values that are compile time options */ 3253 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 3254 V_fw_deny_unknown_exthdrs = 1; 3255 #ifdef IPFIREWALL_VERBOSE 3256 V_fw_verbose = 1; 3257 #endif 3258 #ifdef IPFIREWALL_VERBOSE_LIMIT 3259 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 3260 #endif 3261 #ifdef IPFIREWALL_NAT 3262 LIST_INIT(&chain->nat); 3263 #endif 3264 3265 /* Init shared services hash table */ 3266 ipfw_init_srv(chain); 3267 3268 ipfw_init_counters(); 3269 /* Set initial number of tables */ 3270 V_fw_tables_max = default_fw_tables; 3271 error = ipfw_init_tables(chain, first); 3272 if (error) { 3273 printf("ipfw2: setting up tables failed\n"); 3274 free(chain->map, M_IPFW); 3275 free(rule, M_IPFW); 3276 return (ENOSPC); 3277 } 3278 3279 IPFW_LOCK_INIT(chain); 3280 3281 /* fill and insert the default rule */ 3282 rule = ipfw_alloc_rule(chain, sizeof(struct ip_fw)); 3283 rule->cmd_len = 1; 3284 rule->cmd[0].len = 1; 3285 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY; 3286 chain->default_rule = rule; 3287 ipfw_add_protected_rule(chain, rule, 0); 3288 3289 ipfw_dyn_init(chain); 3290 ipfw_eaction_init(chain, first); 3291 #ifdef LINEAR_SKIPTO 3292 ipfw_init_skipto_cache(chain); 3293 #endif 3294 ipfw_bpf_init(first); 3295 3296 /* First set up some values that are compile time options */ 3297 V_ipfw_vnet_ready = 1; /* Open for business */ 3298 3299 /* 3300 * Hook the sockopt handler and pfil hooks for ipv4 and ipv6. 3301 * Even if the latter two fail we still keep the module alive 3302 * because the sockopt and layer2 paths are still useful. 3303 * ipfw[6]_hook return 0 on success, ENOENT on failure, 3304 * so we can ignore the exact return value and just set a flag. 3305 * 3306 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so 3307 * changes in the underlying (per-vnet) variables trigger 3308 * immediate hook()/unhook() calls. 3309 * In layer2 we have the same behaviour, except that V_ether_ipfw 3310 * is checked on each packet because there are no pfil hooks. 3311 */ 3312 V_ip_fw_ctl_ptr = ipfw_ctl3; 3313 error = ipfw_attach_hooks(1); 3314 return (error); 3315 } 3316 3317 /* 3318 * Called for the removal of each instance. 3319 */ 3320 static int 3321 vnet_ipfw_uninit(const void *unused) 3322 { 3323 struct ip_fw *reap; 3324 struct ip_fw_chain *chain = &V_layer3_chain; 3325 int i, last; 3326 3327 V_ipfw_vnet_ready = 0; /* tell new callers to go away */ 3328 /* 3329 * disconnect from ipv4, ipv6, layer2 and sockopt. 3330 * Then grab, release and grab again the WLOCK so we make 3331 * sure the update is propagated and nobody will be in. 3332 */ 3333 (void)ipfw_attach_hooks(0 /* detach */); 3334 V_ip_fw_ctl_ptr = NULL; 3335 3336 last = IS_DEFAULT_VNET(curvnet) ? 1 : 0; 3337 3338 IPFW_UH_WLOCK(chain); 3339 IPFW_UH_WUNLOCK(chain); 3340 3341 ipfw_dyn_uninit(0); /* run the callout_drain */ 3342 3343 IPFW_UH_WLOCK(chain); 3344 3345 reap = NULL; 3346 IPFW_WLOCK(chain); 3347 for (i = 0; i < chain->n_rules; i++) 3348 ipfw_reap_add(chain, &reap, chain->map[i]); 3349 free(chain->map, M_IPFW); 3350 #ifdef LINEAR_SKIPTO 3351 ipfw_destroy_skipto_cache(chain); 3352 #endif 3353 IPFW_WUNLOCK(chain); 3354 IPFW_UH_WUNLOCK(chain); 3355 ipfw_destroy_tables(chain, last); 3356 ipfw_eaction_uninit(chain, last); 3357 if (reap != NULL) 3358 ipfw_reap_rules(reap); 3359 vnet_ipfw_iface_destroy(chain); 3360 ipfw_destroy_srv(chain); 3361 IPFW_LOCK_DESTROY(chain); 3362 ipfw_dyn_uninit(1); /* free the remaining parts */ 3363 ipfw_destroy_counters(); 3364 ipfw_bpf_uninit(last); 3365 return (0); 3366 } 3367 3368 /* 3369 * Module event handler. 3370 * In general we have the choice of handling most of these events by the 3371 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to 3372 * use the SYSINIT handlers as they are more capable of expressing the 3373 * flow of control during module and vnet operations, so this is just 3374 * a skeleton. Note there is no SYSINIT equivalent of the module 3375 * SHUTDOWN handler, but we don't have anything to do in that case anyhow. 3376 */ 3377 static int 3378 ipfw_modevent(module_t mod, int type, void *unused) 3379 { 3380 int err = 0; 3381 3382 switch (type) { 3383 case MOD_LOAD: 3384 /* Called once at module load or 3385 * system boot if compiled in. */ 3386 break; 3387 case MOD_QUIESCE: 3388 /* Called before unload. May veto unloading. */ 3389 break; 3390 case MOD_UNLOAD: 3391 /* Called during unload. */ 3392 break; 3393 case MOD_SHUTDOWN: 3394 /* Called during system shutdown. */ 3395 break; 3396 default: 3397 err = EOPNOTSUPP; 3398 break; 3399 } 3400 return err; 3401 } 3402 3403 static moduledata_t ipfwmod = { 3404 "ipfw", 3405 ipfw_modevent, 3406 0 3407 }; 3408 3409 /* Define startup order. */ 3410 #define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_FIREWALL 3411 #define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */ 3412 #define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */ 3413 #define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */ 3414 3415 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER); 3416 FEATURE(ipfw_ctl3, "ipfw new sockopt calls"); 3417 MODULE_VERSION(ipfw, 3); 3418 /* should declare some dependencies here */ 3419 3420 /* 3421 * Starting up. Done in order after ipfwmod() has been called. 3422 * VNET_SYSINIT is also called for each existing vnet and each new vnet. 3423 */ 3424 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 3425 ipfw_init, NULL); 3426 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 3427 vnet_ipfw_init, NULL); 3428 3429 /* 3430 * Closing up shop. These are done in REVERSE ORDER, but still 3431 * after ipfwmod() has been called. Not called on reboot. 3432 * VNET_SYSUNINIT is also called for each exiting vnet as it exits. 3433 * or when the module is unloaded. 3434 */ 3435 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 3436 ipfw_destroy, NULL); 3437 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 3438 vnet_ipfw_uninit, NULL); 3439 /* end of file */ 3440