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 VNET_DEFINE_STATIC(int, fw_deny_unknown_exthdrs); 114 #define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs) 115 116 VNET_DEFINE_STATIC(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_parse(struct tcphdr *tcp, uint16_t *mss) 335 { 336 u_char *cp = (u_char *)(tcp + 1); 337 int optlen, bits = 0; 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 default: 354 break; 355 356 case TCPOPT_MAXSEG: 357 bits |= IP_FW_TCPOPT_MSS; 358 if (mss != NULL) 359 *mss = be16dec(cp + 2); 360 break; 361 362 case TCPOPT_WINDOW: 363 bits |= IP_FW_TCPOPT_WINDOW; 364 break; 365 366 case TCPOPT_SACK_PERMITTED: 367 case TCPOPT_SACK: 368 bits |= IP_FW_TCPOPT_SACK; 369 break; 370 371 case TCPOPT_TIMESTAMP: 372 bits |= IP_FW_TCPOPT_TS; 373 break; 374 } 375 } 376 return (bits); 377 } 378 379 static int 380 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 381 { 382 383 return (flags_match(cmd, tcpopts_parse(tcp, NULL))); 384 } 385 386 static int 387 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain, 388 uint32_t *tablearg) 389 { 390 391 if (ifp == NULL) /* no iface with this packet, match fails */ 392 return (0); 393 394 /* Check by name or by IP address */ 395 if (cmd->name[0] != '\0') { /* match by name */ 396 if (cmd->name[0] == '\1') /* use tablearg to match */ 397 return ipfw_lookup_table(chain, cmd->p.kidx, 0, 398 &ifp->if_index, tablearg); 399 /* Check name */ 400 if (cmd->p.glob) { 401 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 402 return(1); 403 } else { 404 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 405 return(1); 406 } 407 } else { 408 #if !defined(USERSPACE) && defined(__FreeBSD__) /* and OSX too ? */ 409 struct ifaddr *ia; 410 411 NET_EPOCH_ASSERT(); 412 413 CK_STAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 414 if (ia->ifa_addr->sa_family != AF_INET) 415 continue; 416 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 417 (ia->ifa_addr))->sin_addr.s_addr) 418 return (1); /* match */ 419 } 420 #endif /* __FreeBSD__ */ 421 } 422 return(0); /* no match, fail ... */ 423 } 424 425 /* 426 * The verify_path function checks if a route to the src exists and 427 * if it is reachable via ifp (when provided). 428 * 429 * The 'verrevpath' option checks that the interface that an IP packet 430 * arrives on is the same interface that traffic destined for the 431 * packet's source address would be routed out of. 432 * The 'versrcreach' option just checks that the source address is 433 * reachable via any route (except default) in the routing table. 434 * These two are a measure to block forged packets. This is also 435 * commonly known as "anti-spoofing" or Unicast Reverse Path 436 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 437 * is purposely reminiscent of the Cisco IOS command, 438 * 439 * ip verify unicast reverse-path 440 * ip verify unicast source reachable-via any 441 * 442 * which implements the same functionality. But note that the syntax 443 * is misleading, and the check may be performed on all IP packets 444 * whether unicast, multicast, or broadcast. 445 */ 446 static int 447 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib) 448 { 449 #if defined(USERSPACE) || !defined(__FreeBSD__) 450 return 0; 451 #else 452 struct nhop4_basic nh4; 453 454 if (fib4_lookup_nh_basic(fib, src, NHR_IFAIF, 0, &nh4) != 0) 455 return (0); 456 457 /* 458 * If ifp is provided, check for equality with rtentry. 459 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 460 * in order to pass packets injected back by if_simloop(): 461 * routing entry (via lo0) for our own address 462 * may exist, so we need to handle routing assymetry. 463 */ 464 if (ifp != NULL && ifp != nh4.nh_ifp) 465 return (0); 466 467 /* if no ifp provided, check if rtentry is not default route */ 468 if (ifp == NULL && (nh4.nh_flags & NHF_DEFAULT) != 0) 469 return (0); 470 471 /* or if this is a blackhole/reject route */ 472 if (ifp == NULL && (nh4.nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0) 473 return (0); 474 475 /* found valid route */ 476 return 1; 477 #endif /* __FreeBSD__ */ 478 } 479 480 /* 481 * Generate an SCTP packet containing an ABORT chunk. The verification tag 482 * is given by vtag. The T-bit is set in the ABORT chunk if and only if 483 * reflected is not 0. 484 */ 485 486 static struct mbuf * 487 ipfw_send_abort(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t vtag, 488 int reflected) 489 { 490 struct mbuf *m; 491 struct ip *ip; 492 #ifdef INET6 493 struct ip6_hdr *ip6; 494 #endif 495 struct sctphdr *sctp; 496 struct sctp_chunkhdr *chunk; 497 u_int16_t hlen, plen, tlen; 498 499 MGETHDR(m, M_NOWAIT, MT_DATA); 500 if (m == NULL) 501 return (NULL); 502 503 M_SETFIB(m, id->fib); 504 #ifdef MAC 505 if (replyto != NULL) 506 mac_netinet_firewall_reply(replyto, m); 507 else 508 mac_netinet_firewall_send(m); 509 #else 510 (void)replyto; /* don't warn about unused arg */ 511 #endif 512 513 switch (id->addr_type) { 514 case 4: 515 hlen = sizeof(struct ip); 516 break; 517 #ifdef INET6 518 case 6: 519 hlen = sizeof(struct ip6_hdr); 520 break; 521 #endif 522 default: 523 /* XXX: log me?!? */ 524 FREE_PKT(m); 525 return (NULL); 526 } 527 plen = sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr); 528 tlen = hlen + plen; 529 m->m_data += max_linkhdr; 530 m->m_flags |= M_SKIP_FIREWALL; 531 m->m_pkthdr.len = m->m_len = tlen; 532 m->m_pkthdr.rcvif = NULL; 533 bzero(m->m_data, tlen); 534 535 switch (id->addr_type) { 536 case 4: 537 ip = mtod(m, struct ip *); 538 539 ip->ip_v = 4; 540 ip->ip_hl = sizeof(struct ip) >> 2; 541 ip->ip_tos = IPTOS_LOWDELAY; 542 ip->ip_len = htons(tlen); 543 ip->ip_id = htons(0); 544 ip->ip_off = htons(0); 545 ip->ip_ttl = V_ip_defttl; 546 ip->ip_p = IPPROTO_SCTP; 547 ip->ip_sum = 0; 548 ip->ip_src.s_addr = htonl(id->dst_ip); 549 ip->ip_dst.s_addr = htonl(id->src_ip); 550 551 sctp = (struct sctphdr *)(ip + 1); 552 break; 553 #ifdef INET6 554 case 6: 555 ip6 = mtod(m, struct ip6_hdr *); 556 557 ip6->ip6_vfc = IPV6_VERSION; 558 ip6->ip6_plen = htons(plen); 559 ip6->ip6_nxt = IPPROTO_SCTP; 560 ip6->ip6_hlim = IPV6_DEFHLIM; 561 ip6->ip6_src = id->dst_ip6; 562 ip6->ip6_dst = id->src_ip6; 563 564 sctp = (struct sctphdr *)(ip6 + 1); 565 break; 566 #endif 567 } 568 569 sctp->src_port = htons(id->dst_port); 570 sctp->dest_port = htons(id->src_port); 571 sctp->v_tag = htonl(vtag); 572 sctp->checksum = htonl(0); 573 574 chunk = (struct sctp_chunkhdr *)(sctp + 1); 575 chunk->chunk_type = SCTP_ABORT_ASSOCIATION; 576 chunk->chunk_flags = 0; 577 if (reflected != 0) { 578 chunk->chunk_flags |= SCTP_HAD_NO_TCB; 579 } 580 chunk->chunk_length = htons(sizeof(struct sctp_chunkhdr)); 581 582 sctp->checksum = sctp_calculate_cksum(m, hlen); 583 584 return (m); 585 } 586 587 /* 588 * Generate a TCP packet, containing either a RST or a keepalive. 589 * When flags & TH_RST, we are sending a RST packet, because of a 590 * "reset" action matched the packet. 591 * Otherwise we are sending a keepalive, and flags & TH_ 592 * The 'replyto' mbuf is the mbuf being replied to, if any, and is required 593 * so that MAC can label the reply appropriately. 594 */ 595 struct mbuf * 596 ipfw_send_pkt(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t seq, 597 u_int32_t ack, int flags) 598 { 599 struct mbuf *m = NULL; /* stupid compiler */ 600 struct ip *h = NULL; /* stupid compiler */ 601 #ifdef INET6 602 struct ip6_hdr *h6 = NULL; 603 #endif 604 struct tcphdr *th = NULL; 605 int len, dir; 606 607 MGETHDR(m, M_NOWAIT, MT_DATA); 608 if (m == NULL) 609 return (NULL); 610 611 M_SETFIB(m, id->fib); 612 #ifdef MAC 613 if (replyto != NULL) 614 mac_netinet_firewall_reply(replyto, m); 615 else 616 mac_netinet_firewall_send(m); 617 #else 618 (void)replyto; /* don't warn about unused arg */ 619 #endif 620 621 switch (id->addr_type) { 622 case 4: 623 len = sizeof(struct ip) + sizeof(struct tcphdr); 624 break; 625 #ifdef INET6 626 case 6: 627 len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 628 break; 629 #endif 630 default: 631 /* XXX: log me?!? */ 632 FREE_PKT(m); 633 return (NULL); 634 } 635 dir = ((flags & (TH_SYN | TH_RST)) == TH_SYN); 636 637 m->m_data += max_linkhdr; 638 m->m_flags |= M_SKIP_FIREWALL; 639 m->m_pkthdr.len = m->m_len = len; 640 m->m_pkthdr.rcvif = NULL; 641 bzero(m->m_data, len); 642 643 switch (id->addr_type) { 644 case 4: 645 h = mtod(m, struct ip *); 646 647 /* prepare for checksum */ 648 h->ip_p = IPPROTO_TCP; 649 h->ip_len = htons(sizeof(struct tcphdr)); 650 if (dir) { 651 h->ip_src.s_addr = htonl(id->src_ip); 652 h->ip_dst.s_addr = htonl(id->dst_ip); 653 } else { 654 h->ip_src.s_addr = htonl(id->dst_ip); 655 h->ip_dst.s_addr = htonl(id->src_ip); 656 } 657 658 th = (struct tcphdr *)(h + 1); 659 break; 660 #ifdef INET6 661 case 6: 662 h6 = mtod(m, struct ip6_hdr *); 663 664 /* prepare for checksum */ 665 h6->ip6_nxt = IPPROTO_TCP; 666 h6->ip6_plen = htons(sizeof(struct tcphdr)); 667 if (dir) { 668 h6->ip6_src = id->src_ip6; 669 h6->ip6_dst = id->dst_ip6; 670 } else { 671 h6->ip6_src = id->dst_ip6; 672 h6->ip6_dst = id->src_ip6; 673 } 674 675 th = (struct tcphdr *)(h6 + 1); 676 break; 677 #endif 678 } 679 680 if (dir) { 681 th->th_sport = htons(id->src_port); 682 th->th_dport = htons(id->dst_port); 683 } else { 684 th->th_sport = htons(id->dst_port); 685 th->th_dport = htons(id->src_port); 686 } 687 th->th_off = sizeof(struct tcphdr) >> 2; 688 689 if (flags & TH_RST) { 690 if (flags & TH_ACK) { 691 th->th_seq = htonl(ack); 692 th->th_flags = TH_RST; 693 } else { 694 if (flags & TH_SYN) 695 seq++; 696 th->th_ack = htonl(seq); 697 th->th_flags = TH_RST | TH_ACK; 698 } 699 } else { 700 /* 701 * Keepalive - use caller provided sequence numbers 702 */ 703 th->th_seq = htonl(seq); 704 th->th_ack = htonl(ack); 705 th->th_flags = TH_ACK; 706 } 707 708 switch (id->addr_type) { 709 case 4: 710 th->th_sum = in_cksum(m, len); 711 712 /* finish the ip header */ 713 h->ip_v = 4; 714 h->ip_hl = sizeof(*h) >> 2; 715 h->ip_tos = IPTOS_LOWDELAY; 716 h->ip_off = htons(0); 717 h->ip_len = htons(len); 718 h->ip_ttl = V_ip_defttl; 719 h->ip_sum = 0; 720 break; 721 #ifdef INET6 722 case 6: 723 th->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(*h6), 724 sizeof(struct tcphdr)); 725 726 /* finish the ip6 header */ 727 h6->ip6_vfc |= IPV6_VERSION; 728 h6->ip6_hlim = IPV6_DEFHLIM; 729 break; 730 #endif 731 } 732 733 return (m); 734 } 735 736 #ifdef INET6 737 /* 738 * ipv6 specific rules here... 739 */ 740 static __inline int 741 icmp6type_match (int type, ipfw_insn_u32 *cmd) 742 { 743 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 744 } 745 746 static int 747 flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 748 { 749 int i; 750 for (i=0; i <= cmd->o.arg1; ++i ) 751 if (curr_flow == cmd->d[i] ) 752 return 1; 753 return 0; 754 } 755 756 /* support for IP6_*_ME opcodes */ 757 static const struct in6_addr lla_mask = {{{ 758 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 759 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff 760 }}}; 761 762 static int 763 ipfw_localip6(struct in6_addr *in6) 764 { 765 struct rm_priotracker in6_ifa_tracker; 766 struct in6_ifaddr *ia; 767 768 if (IN6_IS_ADDR_MULTICAST(in6)) 769 return (0); 770 771 if (!IN6_IS_ADDR_LINKLOCAL(in6)) 772 return (in6_localip(in6)); 773 774 IN6_IFADDR_RLOCK(&in6_ifa_tracker); 775 CK_STAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) { 776 if (!IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) 777 continue; 778 if (IN6_ARE_MASKED_ADDR_EQUAL(&ia->ia_addr.sin6_addr, 779 in6, &lla_mask)) { 780 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 781 return (1); 782 } 783 } 784 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 785 return (0); 786 } 787 788 static int 789 verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib) 790 { 791 struct nhop6_basic nh6; 792 793 if (IN6_IS_SCOPE_LINKLOCAL(src)) 794 return (1); 795 796 if (fib6_lookup_nh_basic(fib, src, 0, NHR_IFAIF, 0, &nh6) != 0) 797 return (0); 798 799 /* If ifp is provided, check for equality with route table. */ 800 if (ifp != NULL && ifp != nh6.nh_ifp) 801 return (0); 802 803 /* if no ifp provided, check if rtentry is not default route */ 804 if (ifp == NULL && (nh6.nh_flags & NHF_DEFAULT) != 0) 805 return (0); 806 807 /* or if this is a blackhole/reject route */ 808 if (ifp == NULL && (nh6.nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0) 809 return (0); 810 811 /* found valid route */ 812 return 1; 813 } 814 815 static int 816 is_icmp6_query(int icmp6_type) 817 { 818 if ((icmp6_type <= ICMP6_MAXTYPE) && 819 (icmp6_type == ICMP6_ECHO_REQUEST || 820 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 821 icmp6_type == ICMP6_WRUREQUEST || 822 icmp6_type == ICMP6_FQDN_QUERY || 823 icmp6_type == ICMP6_NI_QUERY)) 824 return (1); 825 826 return (0); 827 } 828 829 static int 830 map_icmp_unreach(int code) 831 { 832 833 /* RFC 7915 p4.2 */ 834 switch (code) { 835 case ICMP_UNREACH_NET: 836 case ICMP_UNREACH_HOST: 837 case ICMP_UNREACH_SRCFAIL: 838 case ICMP_UNREACH_NET_UNKNOWN: 839 case ICMP_UNREACH_HOST_UNKNOWN: 840 case ICMP_UNREACH_TOSNET: 841 case ICMP_UNREACH_TOSHOST: 842 return (ICMP6_DST_UNREACH_NOROUTE); 843 case ICMP_UNREACH_PORT: 844 return (ICMP6_DST_UNREACH_NOPORT); 845 default: 846 /* 847 * Map the rest of codes into admit prohibited. 848 * XXX: unreach proto should be mapped into ICMPv6 849 * parameter problem, but we use only unreach type. 850 */ 851 return (ICMP6_DST_UNREACH_ADMIN); 852 } 853 } 854 855 static void 856 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 857 { 858 struct mbuf *m; 859 860 m = args->m; 861 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 862 struct tcphdr *tcp; 863 tcp = (struct tcphdr *)((char *)ip6 + hlen); 864 865 if ((tcp->th_flags & TH_RST) == 0) { 866 struct mbuf *m0; 867 m0 = ipfw_send_pkt(args->m, &(args->f_id), 868 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 869 tcp->th_flags | TH_RST); 870 if (m0 != NULL) 871 ip6_output(m0, NULL, NULL, 0, NULL, NULL, 872 NULL); 873 } 874 FREE_PKT(m); 875 } else if (code == ICMP6_UNREACH_ABORT && 876 args->f_id.proto == IPPROTO_SCTP) { 877 struct mbuf *m0; 878 struct sctphdr *sctp; 879 u_int32_t v_tag; 880 int reflected; 881 882 sctp = (struct sctphdr *)((char *)ip6 + hlen); 883 reflected = 1; 884 v_tag = ntohl(sctp->v_tag); 885 /* Investigate the first chunk header if available */ 886 if (m->m_len >= hlen + sizeof(struct sctphdr) + 887 sizeof(struct sctp_chunkhdr)) { 888 struct sctp_chunkhdr *chunk; 889 890 chunk = (struct sctp_chunkhdr *)(sctp + 1); 891 switch (chunk->chunk_type) { 892 case SCTP_INITIATION: 893 /* 894 * Packets containing an INIT chunk MUST have 895 * a zero v-tag. 896 */ 897 if (v_tag != 0) { 898 v_tag = 0; 899 break; 900 } 901 /* INIT chunk MUST NOT be bundled */ 902 if (m->m_pkthdr.len > 903 hlen + sizeof(struct sctphdr) + 904 ntohs(chunk->chunk_length) + 3) { 905 break; 906 } 907 /* Use the initiate tag if available */ 908 if ((m->m_len >= hlen + sizeof(struct sctphdr) + 909 sizeof(struct sctp_chunkhdr) + 910 offsetof(struct sctp_init, a_rwnd))) { 911 struct sctp_init *init; 912 913 init = (struct sctp_init *)(chunk + 1); 914 v_tag = ntohl(init->initiate_tag); 915 reflected = 0; 916 } 917 break; 918 case SCTP_ABORT_ASSOCIATION: 919 /* 920 * If the packet contains an ABORT chunk, don't 921 * reply. 922 * XXX: We should search through all chunks, 923 * but don't do to avoid attacks. 924 */ 925 v_tag = 0; 926 break; 927 } 928 } 929 if (v_tag == 0) { 930 m0 = NULL; 931 } else { 932 m0 = ipfw_send_abort(args->m, &(args->f_id), v_tag, 933 reflected); 934 } 935 if (m0 != NULL) 936 ip6_output(m0, NULL, NULL, 0, NULL, NULL, NULL); 937 FREE_PKT(m); 938 } else if (code != ICMP6_UNREACH_RST && code != ICMP6_UNREACH_ABORT) { 939 /* Send an ICMPv6 unreach. */ 940 #if 0 941 /* 942 * Unlike above, the mbufs need to line up with the ip6 hdr, 943 * as the contents are read. We need to m_adj() the 944 * needed amount. 945 * The mbuf will however be thrown away so we can adjust it. 946 * Remember we did an m_pullup on it already so we 947 * can make some assumptions about contiguousness. 948 */ 949 if (args->L3offset) 950 m_adj(m, args->L3offset); 951 #endif 952 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 953 } else 954 FREE_PKT(m); 955 956 args->m = NULL; 957 } 958 959 #endif /* INET6 */ 960 961 962 /* 963 * sends a reject message, consuming the mbuf passed as an argument. 964 */ 965 static void 966 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip) 967 { 968 969 #if 0 970 /* XXX When ip is not guaranteed to be at mtod() we will 971 * need to account for this */ 972 * The mbuf will however be thrown away so we can adjust it. 973 * Remember we did an m_pullup on it already so we 974 * can make some assumptions about contiguousness. 975 */ 976 if (args->L3offset) 977 m_adj(m, args->L3offset); 978 #endif 979 if (code != ICMP_REJECT_RST && code != ICMP_REJECT_ABORT) { 980 /* Send an ICMP unreach */ 981 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 982 } else if (code == ICMP_REJECT_RST && args->f_id.proto == IPPROTO_TCP) { 983 struct tcphdr *const tcp = 984 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 985 if ( (tcp->th_flags & TH_RST) == 0) { 986 struct mbuf *m; 987 m = ipfw_send_pkt(args->m, &(args->f_id), 988 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 989 tcp->th_flags | TH_RST); 990 if (m != NULL) 991 ip_output(m, NULL, NULL, 0, NULL, NULL); 992 } 993 FREE_PKT(args->m); 994 } else if (code == ICMP_REJECT_ABORT && 995 args->f_id.proto == IPPROTO_SCTP) { 996 struct mbuf *m; 997 struct sctphdr *sctp; 998 struct sctp_chunkhdr *chunk; 999 struct sctp_init *init; 1000 u_int32_t v_tag; 1001 int reflected; 1002 1003 sctp = L3HDR(struct sctphdr, mtod(args->m, struct ip *)); 1004 reflected = 1; 1005 v_tag = ntohl(sctp->v_tag); 1006 if (iplen >= (ip->ip_hl << 2) + sizeof(struct sctphdr) + 1007 sizeof(struct sctp_chunkhdr)) { 1008 /* Look at the first chunk header if available */ 1009 chunk = (struct sctp_chunkhdr *)(sctp + 1); 1010 switch (chunk->chunk_type) { 1011 case SCTP_INITIATION: 1012 /* 1013 * Packets containing an INIT chunk MUST have 1014 * a zero v-tag. 1015 */ 1016 if (v_tag != 0) { 1017 v_tag = 0; 1018 break; 1019 } 1020 /* INIT chunk MUST NOT be bundled */ 1021 if (iplen > 1022 (ip->ip_hl << 2) + sizeof(struct sctphdr) + 1023 ntohs(chunk->chunk_length) + 3) { 1024 break; 1025 } 1026 /* Use the initiate tag if available */ 1027 if ((iplen >= (ip->ip_hl << 2) + 1028 sizeof(struct sctphdr) + 1029 sizeof(struct sctp_chunkhdr) + 1030 offsetof(struct sctp_init, a_rwnd))) { 1031 init = (struct sctp_init *)(chunk + 1); 1032 v_tag = ntohl(init->initiate_tag); 1033 reflected = 0; 1034 } 1035 break; 1036 case SCTP_ABORT_ASSOCIATION: 1037 /* 1038 * If the packet contains an ABORT chunk, don't 1039 * reply. 1040 * XXX: We should search through all chunks, 1041 * but don't do to avoid attacks. 1042 */ 1043 v_tag = 0; 1044 break; 1045 } 1046 } 1047 if (v_tag == 0) { 1048 m = NULL; 1049 } else { 1050 m = ipfw_send_abort(args->m, &(args->f_id), v_tag, 1051 reflected); 1052 } 1053 if (m != NULL) 1054 ip_output(m, NULL, NULL, 0, NULL, NULL); 1055 FREE_PKT(args->m); 1056 } else 1057 FREE_PKT(args->m); 1058 args->m = NULL; 1059 } 1060 1061 /* 1062 * Support for uid/gid/jail lookup. These tests are expensive 1063 * (because we may need to look into the list of active sockets) 1064 * so we cache the results. ugid_lookupp is 0 if we have not 1065 * yet done a lookup, 1 if we succeeded, and -1 if we tried 1066 * and failed. The function always returns the match value. 1067 * We could actually spare the variable and use *uc, setting 1068 * it to '(void *)check_uidgid if we have no info, NULL if 1069 * we tried and failed, or any other value if successful. 1070 */ 1071 static int 1072 check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp, 1073 struct ucred **uc) 1074 { 1075 #if defined(USERSPACE) 1076 return 0; // not supported in userspace 1077 #else 1078 #ifndef __FreeBSD__ 1079 /* XXX */ 1080 return cred_check(insn, proto, oif, 1081 dst_ip, dst_port, src_ip, src_port, 1082 (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb); 1083 #else /* FreeBSD */ 1084 struct in_addr src_ip, dst_ip; 1085 struct inpcbinfo *pi; 1086 struct ipfw_flow_id *id; 1087 struct inpcb *pcb, *inp; 1088 int lookupflags; 1089 int match; 1090 1091 id = &args->f_id; 1092 inp = args->inp; 1093 1094 /* 1095 * Check to see if the UDP or TCP stack supplied us with 1096 * the PCB. If so, rather then holding a lock and looking 1097 * up the PCB, we can use the one that was supplied. 1098 */ 1099 if (inp && *ugid_lookupp == 0) { 1100 INP_LOCK_ASSERT(inp); 1101 if (inp->inp_socket != NULL) { 1102 *uc = crhold(inp->inp_cred); 1103 *ugid_lookupp = 1; 1104 } else 1105 *ugid_lookupp = -1; 1106 } 1107 /* 1108 * If we have already been here and the packet has no 1109 * PCB entry associated with it, then we can safely 1110 * assume that this is a no match. 1111 */ 1112 if (*ugid_lookupp == -1) 1113 return (0); 1114 if (id->proto == IPPROTO_TCP) { 1115 lookupflags = 0; 1116 pi = &V_tcbinfo; 1117 } else if (id->proto == IPPROTO_UDP) { 1118 lookupflags = INPLOOKUP_WILDCARD; 1119 pi = &V_udbinfo; 1120 } else if (id->proto == IPPROTO_UDPLITE) { 1121 lookupflags = INPLOOKUP_WILDCARD; 1122 pi = &V_ulitecbinfo; 1123 } else 1124 return 0; 1125 lookupflags |= INPLOOKUP_RLOCKPCB; 1126 match = 0; 1127 if (*ugid_lookupp == 0) { 1128 if (id->addr_type == 6) { 1129 #ifdef INET6 1130 if (args->flags & IPFW_ARGS_IN) 1131 pcb = in6_pcblookup_mbuf(pi, 1132 &id->src_ip6, htons(id->src_port), 1133 &id->dst_ip6, htons(id->dst_port), 1134 lookupflags, NULL, args->m); 1135 else 1136 pcb = in6_pcblookup_mbuf(pi, 1137 &id->dst_ip6, htons(id->dst_port), 1138 &id->src_ip6, htons(id->src_port), 1139 lookupflags, args->ifp, args->m); 1140 #else 1141 *ugid_lookupp = -1; 1142 return (0); 1143 #endif 1144 } else { 1145 src_ip.s_addr = htonl(id->src_ip); 1146 dst_ip.s_addr = htonl(id->dst_ip); 1147 if (args->flags & IPFW_ARGS_IN) 1148 pcb = in_pcblookup_mbuf(pi, 1149 src_ip, htons(id->src_port), 1150 dst_ip, htons(id->dst_port), 1151 lookupflags, NULL, args->m); 1152 else 1153 pcb = in_pcblookup_mbuf(pi, 1154 dst_ip, htons(id->dst_port), 1155 src_ip, htons(id->src_port), 1156 lookupflags, args->ifp, args->m); 1157 } 1158 if (pcb != NULL) { 1159 INP_RLOCK_ASSERT(pcb); 1160 *uc = crhold(pcb->inp_cred); 1161 *ugid_lookupp = 1; 1162 INP_RUNLOCK(pcb); 1163 } 1164 if (*ugid_lookupp == 0) { 1165 /* 1166 * We tried and failed, set the variable to -1 1167 * so we will not try again on this packet. 1168 */ 1169 *ugid_lookupp = -1; 1170 return (0); 1171 } 1172 } 1173 if (insn->o.opcode == O_UID) 1174 match = ((*uc)->cr_uid == (uid_t)insn->d[0]); 1175 else if (insn->o.opcode == O_GID) 1176 match = groupmember((gid_t)insn->d[0], *uc); 1177 else if (insn->o.opcode == O_JAIL) 1178 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]); 1179 return (match); 1180 #endif /* __FreeBSD__ */ 1181 #endif /* not supported in userspace */ 1182 } 1183 1184 /* 1185 * Helper function to set args with info on the rule after the matching 1186 * one. slot is precise, whereas we guess rule_id as they are 1187 * assigned sequentially. 1188 */ 1189 static inline void 1190 set_match(struct ip_fw_args *args, int slot, 1191 struct ip_fw_chain *chain) 1192 { 1193 args->rule.chain_id = chain->id; 1194 args->rule.slot = slot + 1; /* we use 0 as a marker */ 1195 args->rule.rule_id = 1 + chain->map[slot]->id; 1196 args->rule.rulenum = chain->map[slot]->rulenum; 1197 args->flags |= IPFW_ARGS_REF; 1198 } 1199 1200 #ifndef LINEAR_SKIPTO 1201 /* 1202 * Helper function to enable cached rule lookups using 1203 * cached_id and cached_pos fields in ipfw rule. 1204 */ 1205 static int 1206 jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 1207 int tablearg, int jump_backwards) 1208 { 1209 int f_pos; 1210 1211 /* If possible use cached f_pos (in f->cached_pos), 1212 * whose version is written in f->cached_id 1213 * (horrible hacks to avoid changing the ABI). 1214 */ 1215 if (num != IP_FW_TARG && f->cached_id == chain->id) 1216 f_pos = f->cached_pos; 1217 else { 1218 int i = IP_FW_ARG_TABLEARG(chain, num, skipto); 1219 /* make sure we do not jump backward */ 1220 if (jump_backwards == 0 && i <= f->rulenum) 1221 i = f->rulenum + 1; 1222 if (chain->idxmap != NULL) 1223 f_pos = chain->idxmap[i]; 1224 else 1225 f_pos = ipfw_find_rule(chain, i, 0); 1226 /* update the cache */ 1227 if (num != IP_FW_TARG) { 1228 f->cached_id = chain->id; 1229 f->cached_pos = f_pos; 1230 } 1231 } 1232 1233 return (f_pos); 1234 } 1235 #else 1236 /* 1237 * Helper function to enable real fast rule lookups. 1238 */ 1239 static int 1240 jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num, 1241 int tablearg, int jump_backwards) 1242 { 1243 int f_pos; 1244 1245 num = IP_FW_ARG_TABLEARG(chain, num, skipto); 1246 /* make sure we do not jump backward */ 1247 if (jump_backwards == 0 && num <= f->rulenum) 1248 num = f->rulenum + 1; 1249 f_pos = chain->idxmap[num]; 1250 1251 return (f_pos); 1252 } 1253 #endif 1254 1255 #define TARG(k, f) IP_FW_ARG_TABLEARG(chain, k, f) 1256 /* 1257 * The main check routine for the firewall. 1258 * 1259 * All arguments are in args so we can modify them and return them 1260 * back to the caller. 1261 * 1262 * Parameters: 1263 * 1264 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 1265 * Starts with the IP header. 1266 * args->L3offset Number of bytes bypassed if we came from L2. 1267 * e.g. often sizeof(eh) ** NOTYET ** 1268 * args->ifp Incoming or outgoing interface. 1269 * args->divert_rule (in/out) 1270 * Skip up to the first rule past this rule number; 1271 * upon return, non-zero port number for divert or tee. 1272 * 1273 * args->rule Pointer to the last matching rule (in/out) 1274 * args->next_hop Socket we are forwarding to (out). 1275 * args->next_hop6 IPv6 next hop we are forwarding to (out). 1276 * args->f_id Addresses grabbed from the packet (out) 1277 * args->rule.info a cookie depending on rule action 1278 * 1279 * Return value: 1280 * 1281 * IP_FW_PASS the packet must be accepted 1282 * IP_FW_DENY the packet must be dropped 1283 * IP_FW_DIVERT divert packet, port in m_tag 1284 * IP_FW_TEE tee packet, port in m_tag 1285 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 1286 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 1287 * args->rule contains the matching rule, 1288 * args->rule.info has additional information. 1289 * 1290 */ 1291 int 1292 ipfw_chk(struct ip_fw_args *args) 1293 { 1294 1295 /* 1296 * Local variables holding state while processing a packet: 1297 * 1298 * IMPORTANT NOTE: to speed up the processing of rules, there 1299 * are some assumption on the values of the variables, which 1300 * are documented here. Should you change them, please check 1301 * the implementation of the various instructions to make sure 1302 * that they still work. 1303 * 1304 * m | args->m Pointer to the mbuf, as received from the caller. 1305 * It may change if ipfw_chk() does an m_pullup, or if it 1306 * consumes the packet because it calls send_reject(). 1307 * XXX This has to change, so that ipfw_chk() never modifies 1308 * or consumes the buffer. 1309 * OR 1310 * args->mem Pointer to contigous memory chunk. 1311 * ip Is the beginning of the ip(4 or 6) header. 1312 * eh Ethernet header in case if input is Layer2. 1313 */ 1314 struct mbuf *m; 1315 struct ip *ip; 1316 struct ether_header *eh; 1317 1318 /* 1319 * For rules which contain uid/gid or jail constraints, cache 1320 * a copy of the users credentials after the pcb lookup has been 1321 * executed. This will speed up the processing of rules with 1322 * these types of constraints, as well as decrease contention 1323 * on pcb related locks. 1324 */ 1325 #ifndef __FreeBSD__ 1326 struct bsd_ucred ucred_cache; 1327 #else 1328 struct ucred *ucred_cache = NULL; 1329 #endif 1330 int ucred_lookup = 0; 1331 int f_pos = 0; /* index of current rule in the array */ 1332 int retval = 0; 1333 struct ifnet *oif, *iif; 1334 1335 /* 1336 * hlen The length of the IP header. 1337 */ 1338 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 1339 1340 /* 1341 * offset The offset of a fragment. offset != 0 means that 1342 * we have a fragment at this offset of an IPv4 packet. 1343 * offset == 0 means that (if this is an IPv4 packet) 1344 * this is the first or only fragment. 1345 * For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header 1346 * or there is a single packet fragment (fragment header added 1347 * without needed). We will treat a single packet fragment as if 1348 * there was no fragment header (or log/block depending on the 1349 * V_fw_permit_single_frag6 sysctl setting). 1350 */ 1351 u_short offset = 0; 1352 u_short ip6f_mf = 0; 1353 1354 /* 1355 * Local copies of addresses. They are only valid if we have 1356 * an IP packet. 1357 * 1358 * proto The protocol. Set to 0 for non-ip packets, 1359 * or to the protocol read from the packet otherwise. 1360 * proto != 0 means that we have an IPv4 packet. 1361 * 1362 * src_port, dst_port port numbers, in HOST format. Only 1363 * valid for TCP and UDP packets. 1364 * 1365 * src_ip, dst_ip ip addresses, in NETWORK format. 1366 * Only valid for IPv4 packets. 1367 */ 1368 uint8_t proto; 1369 uint16_t src_port, dst_port; /* NOTE: host format */ 1370 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 1371 int iplen = 0; 1372 int pktlen; 1373 1374 struct ipfw_dyn_info dyn_info; 1375 struct ip_fw *q = NULL; 1376 struct ip_fw_chain *chain = &V_layer3_chain; 1377 1378 /* 1379 * We store in ulp a pointer to the upper layer protocol header. 1380 * In the ipv4 case this is easy to determine from the header, 1381 * but for ipv6 we might have some additional headers in the middle. 1382 * ulp is NULL if not found. 1383 */ 1384 void *ulp = NULL; /* upper layer protocol pointer. */ 1385 1386 /* XXX ipv6 variables */ 1387 int is_ipv6 = 0; 1388 uint8_t icmp6_type = 0; 1389 uint16_t ext_hd = 0; /* bits vector for extension header filtering */ 1390 /* end of ipv6 variables */ 1391 1392 int is_ipv4 = 0; 1393 1394 int done = 0; /* flag to exit the outer loop */ 1395 IPFW_RLOCK_TRACKER; 1396 bool mem; 1397 1398 if ((mem = (args->flags & IPFW_ARGS_LENMASK))) { 1399 if (args->flags & IPFW_ARGS_ETHER) { 1400 eh = (struct ether_header *)args->mem; 1401 if (eh->ether_type == htons(ETHERTYPE_VLAN)) 1402 ip = (struct ip *) 1403 ((struct ether_vlan_header *)eh + 1); 1404 else 1405 ip = (struct ip *)(eh + 1); 1406 } else { 1407 eh = NULL; 1408 ip = (struct ip *)args->mem; 1409 } 1410 pktlen = IPFW_ARGS_LENGTH(args->flags); 1411 args->f_id.fib = args->ifp->if_fib; /* best guess */ 1412 } else { 1413 m = args->m; 1414 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready)) 1415 return (IP_FW_PASS); /* accept */ 1416 if (args->flags & IPFW_ARGS_ETHER) { 1417 /* We need some amount of data to be contiguous. */ 1418 if (m->m_len < min(m->m_pkthdr.len, max_protohdr) && 1419 (args->m = m = m_pullup(m, min(m->m_pkthdr.len, 1420 max_protohdr))) == NULL) 1421 goto pullup_failed; 1422 eh = mtod(m, struct ether_header *); 1423 ip = (struct ip *)(eh + 1); 1424 } else { 1425 eh = NULL; 1426 ip = mtod(m, struct ip *); 1427 } 1428 pktlen = m->m_pkthdr.len; 1429 args->f_id.fib = M_GETFIB(m); /* mbuf not altered */ 1430 } 1431 1432 dst_ip.s_addr = 0; /* make sure it is initialized */ 1433 src_ip.s_addr = 0; /* make sure it is initialized */ 1434 src_port = dst_port = 0; 1435 1436 DYN_INFO_INIT(&dyn_info); 1437 /* 1438 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 1439 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 1440 * pointer might become stale after other pullups (but we never use it 1441 * this way). 1442 */ 1443 #define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T)) 1444 #define EHLEN (eh != NULL ? ((char *)ip - (char *)eh) : 0) 1445 #define _PULLUP_LOCKED(_len, p, T, unlock) \ 1446 do { \ 1447 int x = (_len) + T + EHLEN; \ 1448 if (mem) { \ 1449 if (__predict_false(pktlen < x)) { \ 1450 unlock; \ 1451 goto pullup_failed; \ 1452 } \ 1453 p = (char *)args->mem + (_len) + EHLEN; \ 1454 } else { \ 1455 if (__predict_false((m)->m_len < x)) { \ 1456 args->m = m = m_pullup(m, x); \ 1457 if (m == NULL) { \ 1458 unlock; \ 1459 goto pullup_failed; \ 1460 } \ 1461 } \ 1462 p = mtod(m, char *) + (_len) + EHLEN; \ 1463 } \ 1464 } while (0) 1465 1466 #define PULLUP_LEN(_len, p, T) _PULLUP_LOCKED(_len, p, T, ) 1467 #define PULLUP_LEN_LOCKED(_len, p, T) \ 1468 _PULLUP_LOCKED(_len, p, T, IPFW_PF_RUNLOCK(chain)) 1469 /* 1470 * In case pointers got stale after pullups, update them. 1471 */ 1472 #define UPDATE_POINTERS() \ 1473 do { \ 1474 if (!mem) { \ 1475 if (eh != NULL) { \ 1476 eh = mtod(m, struct ether_header *); \ 1477 ip = (struct ip *)(eh + 1); \ 1478 } else \ 1479 ip = mtod(m, struct ip *); \ 1480 args->m = m; \ 1481 } \ 1482 } while (0) 1483 1484 /* Identify IP packets and fill up variables. */ 1485 if (pktlen >= sizeof(struct ip6_hdr) && 1486 (eh == NULL || eh->ether_type == htons(ETHERTYPE_IPV6)) && 1487 ip->ip_v == 6) { 1488 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 1489 1490 is_ipv6 = 1; 1491 args->flags |= IPFW_ARGS_IP6; 1492 hlen = sizeof(struct ip6_hdr); 1493 proto = ip6->ip6_nxt; 1494 /* Search extension headers to find upper layer protocols */ 1495 while (ulp == NULL && offset == 0) { 1496 switch (proto) { 1497 case IPPROTO_ICMPV6: 1498 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 1499 icmp6_type = ICMP6(ulp)->icmp6_type; 1500 break; 1501 1502 case IPPROTO_TCP: 1503 PULLUP_TO(hlen, ulp, struct tcphdr); 1504 dst_port = TCP(ulp)->th_dport; 1505 src_port = TCP(ulp)->th_sport; 1506 /* save flags for dynamic rules */ 1507 args->f_id._flags = TCP(ulp)->th_flags; 1508 break; 1509 1510 case IPPROTO_SCTP: 1511 if (pktlen >= hlen + sizeof(struct sctphdr) + 1512 sizeof(struct sctp_chunkhdr) + 1513 offsetof(struct sctp_init, a_rwnd)) 1514 PULLUP_LEN(hlen, ulp, 1515 sizeof(struct sctphdr) + 1516 sizeof(struct sctp_chunkhdr) + 1517 offsetof(struct sctp_init, a_rwnd)); 1518 else if (pktlen >= hlen + sizeof(struct sctphdr)) 1519 PULLUP_LEN(hlen, ulp, pktlen - hlen); 1520 else 1521 PULLUP_LEN(hlen, ulp, 1522 sizeof(struct sctphdr)); 1523 src_port = SCTP(ulp)->src_port; 1524 dst_port = SCTP(ulp)->dest_port; 1525 break; 1526 1527 case IPPROTO_UDP: 1528 case IPPROTO_UDPLITE: 1529 PULLUP_TO(hlen, ulp, struct udphdr); 1530 dst_port = UDP(ulp)->uh_dport; 1531 src_port = UDP(ulp)->uh_sport; 1532 break; 1533 1534 case IPPROTO_HOPOPTS: /* RFC 2460 */ 1535 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1536 ext_hd |= EXT_HOPOPTS; 1537 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1538 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1539 ulp = NULL; 1540 break; 1541 1542 case IPPROTO_ROUTING: /* RFC 2460 */ 1543 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 1544 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 1545 case 0: 1546 ext_hd |= EXT_RTHDR0; 1547 break; 1548 case 2: 1549 ext_hd |= EXT_RTHDR2; 1550 break; 1551 default: 1552 if (V_fw_verbose) 1553 printf("IPFW2: IPV6 - Unknown " 1554 "Routing Header type(%d)\n", 1555 ((struct ip6_rthdr *) 1556 ulp)->ip6r_type); 1557 if (V_fw_deny_unknown_exthdrs) 1558 return (IP_FW_DENY); 1559 break; 1560 } 1561 ext_hd |= EXT_ROUTING; 1562 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 1563 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 1564 ulp = NULL; 1565 break; 1566 1567 case IPPROTO_FRAGMENT: /* RFC 2460 */ 1568 PULLUP_TO(hlen, ulp, struct ip6_frag); 1569 ext_hd |= EXT_FRAGMENT; 1570 hlen += sizeof (struct ip6_frag); 1571 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 1572 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 1573 IP6F_OFF_MASK; 1574 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg & 1575 IP6F_MORE_FRAG; 1576 if (V_fw_permit_single_frag6 == 0 && 1577 offset == 0 && ip6f_mf == 0) { 1578 if (V_fw_verbose) 1579 printf("IPFW2: IPV6 - Invalid " 1580 "Fragment Header\n"); 1581 if (V_fw_deny_unknown_exthdrs) 1582 return (IP_FW_DENY); 1583 break; 1584 } 1585 args->f_id.extra = 1586 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 1587 ulp = NULL; 1588 break; 1589 1590 case IPPROTO_DSTOPTS: /* RFC 2460 */ 1591 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1592 ext_hd |= EXT_DSTOPTS; 1593 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1594 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1595 ulp = NULL; 1596 break; 1597 1598 case IPPROTO_AH: /* RFC 2402 */ 1599 PULLUP_TO(hlen, ulp, struct ip6_ext); 1600 ext_hd |= EXT_AH; 1601 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 1602 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 1603 ulp = NULL; 1604 break; 1605 1606 case IPPROTO_ESP: /* RFC 2406 */ 1607 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 1608 /* Anything past Seq# is variable length and 1609 * data past this ext. header is encrypted. */ 1610 ext_hd |= EXT_ESP; 1611 break; 1612 1613 case IPPROTO_NONE: /* RFC 2460 */ 1614 /* 1615 * Packet ends here, and IPv6 header has 1616 * already been pulled up. If ip6e_len!=0 1617 * then octets must be ignored. 1618 */ 1619 ulp = ip; /* non-NULL to get out of loop. */ 1620 break; 1621 1622 case IPPROTO_OSPFIGP: 1623 /* XXX OSPF header check? */ 1624 PULLUP_TO(hlen, ulp, struct ip6_ext); 1625 break; 1626 1627 case IPPROTO_PIM: 1628 /* XXX PIM header check? */ 1629 PULLUP_TO(hlen, ulp, struct pim); 1630 break; 1631 1632 case IPPROTO_GRE: /* RFC 1701 */ 1633 /* XXX GRE header check? */ 1634 PULLUP_TO(hlen, ulp, struct grehdr); 1635 break; 1636 1637 case IPPROTO_CARP: 1638 PULLUP_TO(hlen, ulp, offsetof( 1639 struct carp_header, carp_counter)); 1640 if (CARP_ADVERTISEMENT != 1641 ((struct carp_header *)ulp)->carp_type) 1642 return (IP_FW_DENY); 1643 break; 1644 1645 case IPPROTO_IPV6: /* RFC 2893 */ 1646 PULLUP_TO(hlen, ulp, struct ip6_hdr); 1647 break; 1648 1649 case IPPROTO_IPV4: /* RFC 2893 */ 1650 PULLUP_TO(hlen, ulp, struct ip); 1651 break; 1652 1653 default: 1654 if (V_fw_verbose) 1655 printf("IPFW2: IPV6 - Unknown " 1656 "Extension Header(%d), ext_hd=%x\n", 1657 proto, ext_hd); 1658 if (V_fw_deny_unknown_exthdrs) 1659 return (IP_FW_DENY); 1660 PULLUP_TO(hlen, ulp, struct ip6_ext); 1661 break; 1662 } /*switch */ 1663 } 1664 UPDATE_POINTERS(); 1665 ip6 = (struct ip6_hdr *)ip; 1666 args->f_id.addr_type = 6; 1667 args->f_id.src_ip6 = ip6->ip6_src; 1668 args->f_id.dst_ip6 = ip6->ip6_dst; 1669 args->f_id.flow_id6 = ntohl(ip6->ip6_flow); 1670 iplen = ntohs(ip6->ip6_plen) + sizeof(*ip6); 1671 } else if (pktlen >= sizeof(struct ip) && 1672 (eh == NULL || eh->ether_type == htons(ETHERTYPE_IP)) && 1673 ip->ip_v == 4) { 1674 is_ipv4 = 1; 1675 args->flags |= IPFW_ARGS_IP4; 1676 hlen = ip->ip_hl << 2; 1677 /* 1678 * Collect parameters into local variables for faster 1679 * matching. 1680 */ 1681 proto = ip->ip_p; 1682 src_ip = ip->ip_src; 1683 dst_ip = ip->ip_dst; 1684 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1685 iplen = ntohs(ip->ip_len); 1686 1687 if (offset == 0) { 1688 switch (proto) { 1689 case IPPROTO_TCP: 1690 PULLUP_TO(hlen, ulp, struct tcphdr); 1691 dst_port = TCP(ulp)->th_dport; 1692 src_port = TCP(ulp)->th_sport; 1693 /* save flags for dynamic rules */ 1694 args->f_id._flags = TCP(ulp)->th_flags; 1695 break; 1696 1697 case IPPROTO_SCTP: 1698 if (pktlen >= hlen + sizeof(struct sctphdr) + 1699 sizeof(struct sctp_chunkhdr) + 1700 offsetof(struct sctp_init, a_rwnd)) 1701 PULLUP_LEN(hlen, ulp, 1702 sizeof(struct sctphdr) + 1703 sizeof(struct sctp_chunkhdr) + 1704 offsetof(struct sctp_init, a_rwnd)); 1705 else if (pktlen >= hlen + sizeof(struct sctphdr)) 1706 PULLUP_LEN(hlen, ulp, pktlen - hlen); 1707 else 1708 PULLUP_LEN(hlen, ulp, 1709 sizeof(struct sctphdr)); 1710 src_port = SCTP(ulp)->src_port; 1711 dst_port = SCTP(ulp)->dest_port; 1712 break; 1713 1714 case IPPROTO_UDP: 1715 case IPPROTO_UDPLITE: 1716 PULLUP_TO(hlen, ulp, struct udphdr); 1717 dst_port = UDP(ulp)->uh_dport; 1718 src_port = UDP(ulp)->uh_sport; 1719 break; 1720 1721 case IPPROTO_ICMP: 1722 PULLUP_TO(hlen, ulp, struct icmphdr); 1723 //args->f_id.flags = ICMP(ulp)->icmp_type; 1724 break; 1725 1726 default: 1727 break; 1728 } 1729 } else { 1730 if (offset == 1 && proto == IPPROTO_TCP) { 1731 /* RFC 3128 */ 1732 goto pullup_failed; 1733 } 1734 } 1735 1736 UPDATE_POINTERS(); 1737 args->f_id.addr_type = 4; 1738 args->f_id.src_ip = ntohl(src_ip.s_addr); 1739 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1740 } else { 1741 proto = 0; 1742 dst_ip.s_addr = src_ip.s_addr = 0; 1743 1744 args->f_id.addr_type = 1; /* XXX */ 1745 } 1746 #undef PULLUP_TO 1747 pktlen = iplen < pktlen ? iplen: pktlen; 1748 1749 /* Properly initialize the rest of f_id */ 1750 args->f_id.proto = proto; 1751 args->f_id.src_port = src_port = ntohs(src_port); 1752 args->f_id.dst_port = dst_port = ntohs(dst_port); 1753 1754 IPFW_PF_RLOCK(chain); 1755 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ 1756 IPFW_PF_RUNLOCK(chain); 1757 return (IP_FW_PASS); /* accept */ 1758 } 1759 if (args->flags & IPFW_ARGS_REF) { 1760 /* 1761 * Packet has already been tagged as a result of a previous 1762 * match on rule args->rule aka args->rule_id (PIPE, QUEUE, 1763 * REASS, NETGRAPH, DIVERT/TEE...) 1764 * Validate the slot and continue from the next one 1765 * if still present, otherwise do a lookup. 1766 */ 1767 f_pos = (args->rule.chain_id == chain->id) ? 1768 args->rule.slot : 1769 ipfw_find_rule(chain, args->rule.rulenum, 1770 args->rule.rule_id); 1771 } else { 1772 f_pos = 0; 1773 } 1774 1775 if (args->flags & IPFW_ARGS_IN) { 1776 iif = args->ifp; 1777 oif = NULL; 1778 } else { 1779 MPASS(args->flags & IPFW_ARGS_OUT); 1780 iif = mem ? NULL : m_rcvif(m); 1781 oif = args->ifp; 1782 } 1783 1784 /* 1785 * Now scan the rules, and parse microinstructions for each rule. 1786 * We have two nested loops and an inner switch. Sometimes we 1787 * need to break out of one or both loops, or re-enter one of 1788 * the loops with updated variables. Loop variables are: 1789 * 1790 * f_pos (outer loop) points to the current rule. 1791 * On output it points to the matching rule. 1792 * done (outer loop) is used as a flag to break the loop. 1793 * l (inner loop) residual length of current rule. 1794 * cmd points to the current microinstruction. 1795 * 1796 * We break the inner loop by setting l=0 and possibly 1797 * cmdlen=0 if we don't want to advance cmd. 1798 * We break the outer loop by setting done=1 1799 * We can restart the inner loop by setting l>0 and f_pos, f, cmd 1800 * as needed. 1801 */ 1802 for (; f_pos < chain->n_rules; f_pos++) { 1803 ipfw_insn *cmd; 1804 uint32_t tablearg = 0; 1805 int l, cmdlen, skip_or; /* skip rest of OR block */ 1806 struct ip_fw *f; 1807 1808 f = chain->map[f_pos]; 1809 if (V_set_disable & (1 << f->set) ) 1810 continue; 1811 1812 skip_or = 0; 1813 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 1814 l -= cmdlen, cmd += cmdlen) { 1815 int match; 1816 1817 /* 1818 * check_body is a jump target used when we find a 1819 * CHECK_STATE, and need to jump to the body of 1820 * the target rule. 1821 */ 1822 1823 /* check_body: */ 1824 cmdlen = F_LEN(cmd); 1825 /* 1826 * An OR block (insn_1 || .. || insn_n) has the 1827 * F_OR bit set in all but the last instruction. 1828 * The first match will set "skip_or", and cause 1829 * the following instructions to be skipped until 1830 * past the one with the F_OR bit clear. 1831 */ 1832 if (skip_or) { /* skip this instruction */ 1833 if ((cmd->len & F_OR) == 0) 1834 skip_or = 0; /* next one is good */ 1835 continue; 1836 } 1837 match = 0; /* set to 1 if we succeed */ 1838 1839 switch (cmd->opcode) { 1840 /* 1841 * The first set of opcodes compares the packet's 1842 * fields with some pattern, setting 'match' if a 1843 * match is found. At the end of the loop there is 1844 * logic to deal with F_NOT and F_OR flags associated 1845 * with the opcode. 1846 */ 1847 case O_NOP: 1848 match = 1; 1849 break; 1850 1851 case O_FORWARD_MAC: 1852 printf("ipfw: opcode %d unimplemented\n", 1853 cmd->opcode); 1854 break; 1855 1856 case O_GID: 1857 case O_UID: 1858 case O_JAIL: 1859 /* 1860 * We only check offset == 0 && proto != 0, 1861 * as this ensures that we have a 1862 * packet with the ports info. 1863 */ 1864 if (offset != 0) 1865 break; 1866 if (proto == IPPROTO_TCP || 1867 proto == IPPROTO_UDP || 1868 proto == IPPROTO_UDPLITE) 1869 match = check_uidgid( 1870 (ipfw_insn_u32 *)cmd, 1871 args, &ucred_lookup, 1872 #ifdef __FreeBSD__ 1873 &ucred_cache); 1874 #else 1875 (void *)&ucred_cache); 1876 #endif 1877 break; 1878 1879 case O_RECV: 1880 match = iface_match(iif, (ipfw_insn_if *)cmd, 1881 chain, &tablearg); 1882 break; 1883 1884 case O_XMIT: 1885 match = iface_match(oif, (ipfw_insn_if *)cmd, 1886 chain, &tablearg); 1887 break; 1888 1889 case O_VIA: 1890 match = iface_match(args->ifp, 1891 (ipfw_insn_if *)cmd, chain, &tablearg); 1892 break; 1893 1894 case O_MACADDR2: 1895 if (args->flags & IPFW_ARGS_ETHER) { 1896 u_int32_t *want = (u_int32_t *) 1897 ((ipfw_insn_mac *)cmd)->addr; 1898 u_int32_t *mask = (u_int32_t *) 1899 ((ipfw_insn_mac *)cmd)->mask; 1900 u_int32_t *hdr = (u_int32_t *)eh; 1901 1902 match = 1903 ( want[0] == (hdr[0] & mask[0]) && 1904 want[1] == (hdr[1] & mask[1]) && 1905 want[2] == (hdr[2] & mask[2]) ); 1906 } 1907 break; 1908 1909 case O_MAC_TYPE: 1910 if (args->flags & IPFW_ARGS_ETHER) { 1911 u_int16_t *p = 1912 ((ipfw_insn_u16 *)cmd)->ports; 1913 int i; 1914 1915 for (i = cmdlen - 1; !match && i>0; 1916 i--, p += 2) 1917 match = 1918 (ntohs(eh->ether_type) >= 1919 p[0] && 1920 ntohs(eh->ether_type) <= 1921 p[1]); 1922 } 1923 break; 1924 1925 case O_FRAG: 1926 match = (offset != 0); 1927 break; 1928 1929 case O_IN: /* "out" is "not in" */ 1930 match = (oif == NULL); 1931 break; 1932 1933 case O_LAYER2: 1934 match = (args->flags & IPFW_ARGS_ETHER); 1935 break; 1936 1937 case O_DIVERTED: 1938 if ((args->flags & IPFW_ARGS_REF) == 0) 1939 break; 1940 /* 1941 * For diverted packets, args->rule.info 1942 * contains the divert port (in host format) 1943 * reason and direction. 1944 */ 1945 match = ((args->rule.info & IPFW_IS_MASK) == 1946 IPFW_IS_DIVERT) && ( 1947 ((args->rule.info & IPFW_INFO_IN) ? 1948 1: 2) & cmd->arg1); 1949 break; 1950 1951 case O_PROTO: 1952 /* 1953 * We do not allow an arg of 0 so the 1954 * check of "proto" only suffices. 1955 */ 1956 match = (proto == cmd->arg1); 1957 break; 1958 1959 case O_IP_SRC: 1960 match = is_ipv4 && 1961 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1962 src_ip.s_addr); 1963 break; 1964 1965 case O_IP_DST_LOOKUP: 1966 { 1967 void *pkey; 1968 uint32_t vidx, key; 1969 uint16_t keylen; 1970 1971 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { 1972 /* Determine lookup key type */ 1973 vidx = ((ipfw_insn_u32 *)cmd)->d[1]; 1974 if (vidx != 4 /* uid */ && 1975 vidx != 5 /* jail */ && 1976 is_ipv6 == 0 && is_ipv4 == 0) 1977 break; 1978 /* Determine key length */ 1979 if (vidx == 0 /* dst-ip */ || 1980 vidx == 1 /* src-ip */) 1981 keylen = is_ipv6 ? 1982 sizeof(struct in6_addr): 1983 sizeof(in_addr_t); 1984 else { 1985 keylen = sizeof(key); 1986 pkey = &key; 1987 } 1988 if (vidx == 0 /* dst-ip */) 1989 pkey = is_ipv4 ? (void *)&dst_ip: 1990 (void *)&args->f_id.dst_ip6; 1991 else if (vidx == 1 /* src-ip */) 1992 pkey = is_ipv4 ? (void *)&src_ip: 1993 (void *)&args->f_id.src_ip6; 1994 else if (vidx == 6 /* dscp */) { 1995 if (is_ipv4) 1996 key = ip->ip_tos >> 2; 1997 else { 1998 key = args->f_id.flow_id6; 1999 key = (key & 0x0f) << 2 | 2000 (key & 0xf000) >> 14; 2001 } 2002 key &= 0x3f; 2003 } else if (vidx == 2 /* dst-port */ || 2004 vidx == 3 /* src-port */) { 2005 /* Skip fragments */ 2006 if (offset != 0) 2007 break; 2008 /* Skip proto without ports */ 2009 if (proto != IPPROTO_TCP && 2010 proto != IPPROTO_UDP && 2011 proto != IPPROTO_UDPLITE && 2012 proto != IPPROTO_SCTP) 2013 break; 2014 if (vidx == 2 /* dst-port */) 2015 key = dst_port; 2016 else 2017 key = src_port; 2018 } 2019 #ifndef USERSPACE 2020 else if (vidx == 4 /* uid */ || 2021 vidx == 5 /* jail */) { 2022 check_uidgid( 2023 (ipfw_insn_u32 *)cmd, 2024 args, &ucred_lookup, 2025 #ifdef __FreeBSD__ 2026 &ucred_cache); 2027 if (vidx == 4 /* uid */) 2028 key = ucred_cache->cr_uid; 2029 else if (vidx == 5 /* jail */) 2030 key = ucred_cache->cr_prison->pr_id; 2031 #else /* !__FreeBSD__ */ 2032 (void *)&ucred_cache); 2033 if (vidx == 4 /* uid */) 2034 key = ucred_cache.uid; 2035 else if (vidx == 5 /* jail */) 2036 key = ucred_cache.xid; 2037 #endif /* !__FreeBSD__ */ 2038 } 2039 #endif /* !USERSPACE */ 2040 else 2041 break; 2042 match = ipfw_lookup_table(chain, 2043 cmd->arg1, keylen, pkey, &vidx); 2044 if (!match) 2045 break; 2046 tablearg = vidx; 2047 break; 2048 } 2049 /* cmdlen =< F_INSN_SIZE(ipfw_insn_u32) */ 2050 /* FALLTHROUGH */ 2051 } 2052 case O_IP_SRC_LOOKUP: 2053 { 2054 void *pkey; 2055 uint32_t vidx; 2056 uint16_t keylen; 2057 2058 if (is_ipv4) { 2059 keylen = sizeof(in_addr_t); 2060 if (cmd->opcode == O_IP_DST_LOOKUP) 2061 pkey = &dst_ip; 2062 else 2063 pkey = &src_ip; 2064 } else if (is_ipv6) { 2065 keylen = sizeof(struct in6_addr); 2066 if (cmd->opcode == O_IP_DST_LOOKUP) 2067 pkey = &args->f_id.dst_ip6; 2068 else 2069 pkey = &args->f_id.src_ip6; 2070 } else 2071 break; 2072 match = ipfw_lookup_table(chain, cmd->arg1, 2073 keylen, pkey, &vidx); 2074 if (!match) 2075 break; 2076 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) { 2077 match = ((ipfw_insn_u32 *)cmd)->d[0] == 2078 TARG_VAL(chain, vidx, tag); 2079 if (!match) 2080 break; 2081 } 2082 tablearg = vidx; 2083 break; 2084 } 2085 2086 case O_IP_FLOW_LOOKUP: 2087 { 2088 uint32_t v = 0; 2089 match = ipfw_lookup_table(chain, 2090 cmd->arg1, 0, &args->f_id, &v); 2091 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 2092 match = ((ipfw_insn_u32 *)cmd)->d[0] == 2093 TARG_VAL(chain, v, tag); 2094 if (match) 2095 tablearg = v; 2096 } 2097 break; 2098 case O_IP_SRC_MASK: 2099 case O_IP_DST_MASK: 2100 if (is_ipv4) { 2101 uint32_t a = 2102 (cmd->opcode == O_IP_DST_MASK) ? 2103 dst_ip.s_addr : src_ip.s_addr; 2104 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 2105 int i = cmdlen-1; 2106 2107 for (; !match && i>0; i-= 2, p+= 2) 2108 match = (p[0] == (a & p[1])); 2109 } 2110 break; 2111 2112 case O_IP_SRC_ME: 2113 if (is_ipv4) { 2114 match = in_localip(src_ip); 2115 break; 2116 } 2117 #ifdef INET6 2118 /* FALLTHROUGH */ 2119 case O_IP6_SRC_ME: 2120 match = is_ipv6 && 2121 ipfw_localip6(&args->f_id.src_ip6); 2122 #endif 2123 break; 2124 2125 case O_IP_DST_SET: 2126 case O_IP_SRC_SET: 2127 if (is_ipv4) { 2128 u_int32_t *d = (u_int32_t *)(cmd+1); 2129 u_int32_t addr = 2130 cmd->opcode == O_IP_DST_SET ? 2131 args->f_id.dst_ip : 2132 args->f_id.src_ip; 2133 2134 if (addr < d[0]) 2135 break; 2136 addr -= d[0]; /* subtract base */ 2137 match = (addr < cmd->arg1) && 2138 ( d[ 1 + (addr>>5)] & 2139 (1<<(addr & 0x1f)) ); 2140 } 2141 break; 2142 2143 case O_IP_DST: 2144 match = is_ipv4 && 2145 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2146 dst_ip.s_addr); 2147 break; 2148 2149 case O_IP_DST_ME: 2150 if (is_ipv4) { 2151 match = in_localip(dst_ip); 2152 break; 2153 } 2154 #ifdef INET6 2155 /* FALLTHROUGH */ 2156 case O_IP6_DST_ME: 2157 match = is_ipv6 && 2158 ipfw_localip6(&args->f_id.dst_ip6); 2159 #endif 2160 break; 2161 2162 2163 case O_IP_SRCPORT: 2164 case O_IP_DSTPORT: 2165 /* 2166 * offset == 0 && proto != 0 is enough 2167 * to guarantee that we have a 2168 * packet with port info. 2169 */ 2170 if ((proto == IPPROTO_UDP || 2171 proto == IPPROTO_UDPLITE || 2172 proto == IPPROTO_TCP || 2173 proto == IPPROTO_SCTP) && offset == 0) { 2174 u_int16_t x = 2175 (cmd->opcode == O_IP_SRCPORT) ? 2176 src_port : dst_port ; 2177 u_int16_t *p = 2178 ((ipfw_insn_u16 *)cmd)->ports; 2179 int i; 2180 2181 for (i = cmdlen - 1; !match && i>0; 2182 i--, p += 2) 2183 match = (x>=p[0] && x<=p[1]); 2184 } 2185 break; 2186 2187 case O_ICMPTYPE: 2188 match = (offset == 0 && proto==IPPROTO_ICMP && 2189 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 2190 break; 2191 2192 #ifdef INET6 2193 case O_ICMP6TYPE: 2194 match = is_ipv6 && offset == 0 && 2195 proto==IPPROTO_ICMPV6 && 2196 icmp6type_match( 2197 ICMP6(ulp)->icmp6_type, 2198 (ipfw_insn_u32 *)cmd); 2199 break; 2200 #endif /* INET6 */ 2201 2202 case O_IPOPT: 2203 match = (is_ipv4 && 2204 ipopts_match(ip, cmd) ); 2205 break; 2206 2207 case O_IPVER: 2208 match = (is_ipv4 && 2209 cmd->arg1 == ip->ip_v); 2210 break; 2211 2212 case O_IPID: 2213 case O_IPTTL: 2214 if (!is_ipv4) 2215 break; 2216 case O_IPLEN: 2217 { /* only for IP packets */ 2218 uint16_t x; 2219 uint16_t *p; 2220 int i; 2221 2222 if (cmd->opcode == O_IPLEN) 2223 x = iplen; 2224 else if (cmd->opcode == O_IPTTL) 2225 x = ip->ip_ttl; 2226 else /* must be IPID */ 2227 x = ntohs(ip->ip_id); 2228 if (cmdlen == 1) { 2229 match = (cmd->arg1 == x); 2230 break; 2231 } 2232 /* otherwise we have ranges */ 2233 p = ((ipfw_insn_u16 *)cmd)->ports; 2234 i = cmdlen - 1; 2235 for (; !match && i>0; i--, p += 2) 2236 match = (x >= p[0] && x <= p[1]); 2237 } 2238 break; 2239 2240 case O_IPPRECEDENCE: 2241 match = (is_ipv4 && 2242 (cmd->arg1 == (ip->ip_tos & 0xe0)) ); 2243 break; 2244 2245 case O_IPTOS: 2246 match = (is_ipv4 && 2247 flags_match(cmd, ip->ip_tos)); 2248 break; 2249 2250 case O_DSCP: 2251 { 2252 uint32_t *p; 2253 uint16_t x; 2254 2255 p = ((ipfw_insn_u32 *)cmd)->d; 2256 2257 if (is_ipv4) 2258 x = ip->ip_tos >> 2; 2259 else if (is_ipv6) { 2260 uint8_t *v; 2261 v = &((struct ip6_hdr *)ip)->ip6_vfc; 2262 x = (*v & 0x0F) << 2; 2263 v++; 2264 x |= *v >> 6; 2265 } else 2266 break; 2267 2268 /* DSCP bitmask is stored as low_u32 high_u32 */ 2269 if (x >= 32) 2270 match = *(p + 1) & (1 << (x - 32)); 2271 else 2272 match = *p & (1 << x); 2273 } 2274 break; 2275 2276 case O_TCPDATALEN: 2277 if (proto == IPPROTO_TCP && offset == 0) { 2278 struct tcphdr *tcp; 2279 uint16_t x; 2280 uint16_t *p; 2281 int i; 2282 #ifdef INET6 2283 if (is_ipv6) { 2284 struct ip6_hdr *ip6; 2285 2286 ip6 = (struct ip6_hdr *)ip; 2287 if (ip6->ip6_plen == 0) { 2288 /* 2289 * Jumbo payload is not 2290 * supported by this 2291 * opcode. 2292 */ 2293 break; 2294 } 2295 x = iplen - hlen; 2296 } else 2297 #endif /* INET6 */ 2298 x = iplen - (ip->ip_hl << 2); 2299 tcp = TCP(ulp); 2300 x -= tcp->th_off << 2; 2301 if (cmdlen == 1) { 2302 match = (cmd->arg1 == x); 2303 break; 2304 } 2305 /* otherwise we have ranges */ 2306 p = ((ipfw_insn_u16 *)cmd)->ports; 2307 i = cmdlen - 1; 2308 for (; !match && i>0; i--, p += 2) 2309 match = (x >= p[0] && x <= p[1]); 2310 } 2311 break; 2312 2313 case O_TCPFLAGS: 2314 match = (proto == IPPROTO_TCP && offset == 0 && 2315 flags_match(cmd, TCP(ulp)->th_flags)); 2316 break; 2317 2318 case O_TCPOPTS: 2319 if (proto == IPPROTO_TCP && offset == 0 && ulp){ 2320 PULLUP_LEN_LOCKED(hlen, ulp, 2321 (TCP(ulp)->th_off << 2)); 2322 match = tcpopts_match(TCP(ulp), cmd); 2323 } 2324 break; 2325 2326 case O_TCPSEQ: 2327 match = (proto == IPPROTO_TCP && offset == 0 && 2328 ((ipfw_insn_u32 *)cmd)->d[0] == 2329 TCP(ulp)->th_seq); 2330 break; 2331 2332 case O_TCPACK: 2333 match = (proto == IPPROTO_TCP && offset == 0 && 2334 ((ipfw_insn_u32 *)cmd)->d[0] == 2335 TCP(ulp)->th_ack); 2336 break; 2337 2338 case O_TCPMSS: 2339 if (proto == IPPROTO_TCP && 2340 (args->f_id._flags & TH_SYN) != 0 && 2341 ulp != NULL) { 2342 uint16_t mss, *p; 2343 int i; 2344 2345 PULLUP_LEN_LOCKED(hlen, ulp, 2346 (TCP(ulp)->th_off << 2)); 2347 if ((tcpopts_parse(TCP(ulp), &mss) & 2348 IP_FW_TCPOPT_MSS) == 0) 2349 break; 2350 if (cmdlen == 1) { 2351 match = (cmd->arg1 == mss); 2352 break; 2353 } 2354 /* Otherwise we have ranges. */ 2355 p = ((ipfw_insn_u16 *)cmd)->ports; 2356 i = cmdlen - 1; 2357 for (; !match && i > 0; i--, p += 2) 2358 match = (mss >= p[0] && 2359 mss <= p[1]); 2360 } 2361 break; 2362 2363 case O_TCPWIN: 2364 if (proto == IPPROTO_TCP && offset == 0) { 2365 uint16_t x; 2366 uint16_t *p; 2367 int i; 2368 2369 x = ntohs(TCP(ulp)->th_win); 2370 if (cmdlen == 1) { 2371 match = (cmd->arg1 == x); 2372 break; 2373 } 2374 /* Otherwise we have ranges. */ 2375 p = ((ipfw_insn_u16 *)cmd)->ports; 2376 i = cmdlen - 1; 2377 for (; !match && i > 0; i--, p += 2) 2378 match = (x >= p[0] && x <= p[1]); 2379 } 2380 break; 2381 2382 case O_ESTAB: 2383 /* reject packets which have SYN only */ 2384 /* XXX should i also check for TH_ACK ? */ 2385 match = (proto == IPPROTO_TCP && offset == 0 && 2386 (TCP(ulp)->th_flags & 2387 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 2388 break; 2389 2390 case O_ALTQ: { 2391 struct pf_mtag *at; 2392 struct m_tag *mtag; 2393 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 2394 2395 /* 2396 * ALTQ uses mbuf tags from another 2397 * packet filtering system - pf(4). 2398 * We allocate a tag in its format 2399 * and fill it in, pretending to be pf(4). 2400 */ 2401 match = 1; 2402 at = pf_find_mtag(m); 2403 if (at != NULL && at->qid != 0) 2404 break; 2405 mtag = m_tag_get(PACKET_TAG_PF, 2406 sizeof(struct pf_mtag), M_NOWAIT | M_ZERO); 2407 if (mtag == NULL) { 2408 /* 2409 * Let the packet fall back to the 2410 * default ALTQ. 2411 */ 2412 break; 2413 } 2414 m_tag_prepend(m, mtag); 2415 at = (struct pf_mtag *)(mtag + 1); 2416 at->qid = altq->qid; 2417 at->hdr = ip; 2418 break; 2419 } 2420 2421 case O_LOG: 2422 ipfw_log(chain, f, hlen, args, 2423 offset | ip6f_mf, tablearg, ip); 2424 match = 1; 2425 break; 2426 2427 case O_PROB: 2428 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 2429 break; 2430 2431 case O_VERREVPATH: 2432 /* Outgoing packets automatically pass/match */ 2433 match = (args->flags & IPFW_ARGS_OUT || 2434 ( 2435 #ifdef INET6 2436 is_ipv6 ? 2437 verify_path6(&(args->f_id.src_ip6), 2438 iif, args->f_id.fib) : 2439 #endif 2440 verify_path(src_ip, iif, args->f_id.fib))); 2441 break; 2442 2443 case O_VERSRCREACH: 2444 /* Outgoing packets automatically pass/match */ 2445 match = (hlen > 0 && ((oif != NULL) || ( 2446 #ifdef INET6 2447 is_ipv6 ? 2448 verify_path6(&(args->f_id.src_ip6), 2449 NULL, args->f_id.fib) : 2450 #endif 2451 verify_path(src_ip, NULL, args->f_id.fib)))); 2452 break; 2453 2454 case O_ANTISPOOF: 2455 /* Outgoing packets automatically pass/match */ 2456 if (oif == NULL && hlen > 0 && 2457 ( (is_ipv4 && in_localaddr(src_ip)) 2458 #ifdef INET6 2459 || (is_ipv6 && 2460 in6_localaddr(&(args->f_id.src_ip6))) 2461 #endif 2462 )) 2463 match = 2464 #ifdef INET6 2465 is_ipv6 ? verify_path6( 2466 &(args->f_id.src_ip6), iif, 2467 args->f_id.fib) : 2468 #endif 2469 verify_path(src_ip, iif, 2470 args->f_id.fib); 2471 else 2472 match = 1; 2473 break; 2474 2475 case O_IPSEC: 2476 match = (m_tag_find(m, 2477 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 2478 /* otherwise no match */ 2479 break; 2480 2481 #ifdef INET6 2482 case O_IP6_SRC: 2483 match = is_ipv6 && 2484 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 2485 &((ipfw_insn_ip6 *)cmd)->addr6); 2486 break; 2487 2488 case O_IP6_DST: 2489 match = is_ipv6 && 2490 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 2491 &((ipfw_insn_ip6 *)cmd)->addr6); 2492 break; 2493 case O_IP6_SRC_MASK: 2494 case O_IP6_DST_MASK: 2495 if (is_ipv6) { 2496 int i = cmdlen - 1; 2497 struct in6_addr p; 2498 struct in6_addr *d = 2499 &((ipfw_insn_ip6 *)cmd)->addr6; 2500 2501 for (; !match && i > 0; d += 2, 2502 i -= F_INSN_SIZE(struct in6_addr) 2503 * 2) { 2504 p = (cmd->opcode == 2505 O_IP6_SRC_MASK) ? 2506 args->f_id.src_ip6: 2507 args->f_id.dst_ip6; 2508 APPLY_MASK(&p, &d[1]); 2509 match = 2510 IN6_ARE_ADDR_EQUAL(&d[0], 2511 &p); 2512 } 2513 } 2514 break; 2515 2516 case O_FLOW6ID: 2517 match = is_ipv6 && 2518 flow6id_match(args->f_id.flow_id6, 2519 (ipfw_insn_u32 *) cmd); 2520 break; 2521 2522 case O_EXT_HDR: 2523 match = is_ipv6 && 2524 (ext_hd & ((ipfw_insn *) cmd)->arg1); 2525 break; 2526 2527 case O_IP6: 2528 match = is_ipv6; 2529 break; 2530 #endif 2531 2532 case O_IP4: 2533 match = is_ipv4; 2534 break; 2535 2536 case O_TAG: { 2537 struct m_tag *mtag; 2538 uint32_t tag = TARG(cmd->arg1, tag); 2539 2540 /* Packet is already tagged with this tag? */ 2541 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 2542 2543 /* We have `untag' action when F_NOT flag is 2544 * present. And we must remove this mtag from 2545 * mbuf and reset `match' to zero (`match' will 2546 * be inversed later). 2547 * Otherwise we should allocate new mtag and 2548 * push it into mbuf. 2549 */ 2550 if (cmd->len & F_NOT) { /* `untag' action */ 2551 if (mtag != NULL) 2552 m_tag_delete(m, mtag); 2553 match = 0; 2554 } else { 2555 if (mtag == NULL) { 2556 mtag = m_tag_alloc( MTAG_IPFW, 2557 tag, 0, M_NOWAIT); 2558 if (mtag != NULL) 2559 m_tag_prepend(m, mtag); 2560 } 2561 match = 1; 2562 } 2563 break; 2564 } 2565 2566 case O_FIB: /* try match the specified fib */ 2567 if (args->f_id.fib == cmd->arg1) 2568 match = 1; 2569 break; 2570 2571 case O_SOCKARG: { 2572 #ifndef USERSPACE /* not supported in userspace */ 2573 struct inpcb *inp = args->inp; 2574 struct inpcbinfo *pi; 2575 2576 if (is_ipv6) /* XXX can we remove this ? */ 2577 break; 2578 2579 if (proto == IPPROTO_TCP) 2580 pi = &V_tcbinfo; 2581 else if (proto == IPPROTO_UDP) 2582 pi = &V_udbinfo; 2583 else if (proto == IPPROTO_UDPLITE) 2584 pi = &V_ulitecbinfo; 2585 else 2586 break; 2587 2588 /* 2589 * XXXRW: so_user_cookie should almost 2590 * certainly be inp_user_cookie? 2591 */ 2592 2593 /* For incoming packet, lookup up the 2594 inpcb using the src/dest ip/port tuple */ 2595 if (inp == NULL) { 2596 inp = in_pcblookup(pi, 2597 src_ip, htons(src_port), 2598 dst_ip, htons(dst_port), 2599 INPLOOKUP_RLOCKPCB, NULL); 2600 if (inp != NULL) { 2601 tablearg = 2602 inp->inp_socket->so_user_cookie; 2603 if (tablearg) 2604 match = 1; 2605 INP_RUNLOCK(inp); 2606 } 2607 } else { 2608 if (inp->inp_socket) { 2609 tablearg = 2610 inp->inp_socket->so_user_cookie; 2611 if (tablearg) 2612 match = 1; 2613 } 2614 } 2615 #endif /* !USERSPACE */ 2616 break; 2617 } 2618 2619 case O_TAGGED: { 2620 struct m_tag *mtag; 2621 uint32_t tag = TARG(cmd->arg1, tag); 2622 2623 if (cmdlen == 1) { 2624 match = m_tag_locate(m, MTAG_IPFW, 2625 tag, NULL) != NULL; 2626 break; 2627 } 2628 2629 /* we have ranges */ 2630 for (mtag = m_tag_first(m); 2631 mtag != NULL && !match; 2632 mtag = m_tag_next(m, mtag)) { 2633 uint16_t *p; 2634 int i; 2635 2636 if (mtag->m_tag_cookie != MTAG_IPFW) 2637 continue; 2638 2639 p = ((ipfw_insn_u16 *)cmd)->ports; 2640 i = cmdlen - 1; 2641 for(; !match && i > 0; i--, p += 2) 2642 match = 2643 mtag->m_tag_id >= p[0] && 2644 mtag->m_tag_id <= p[1]; 2645 } 2646 break; 2647 } 2648 2649 /* 2650 * The second set of opcodes represents 'actions', 2651 * i.e. the terminal part of a rule once the packet 2652 * matches all previous patterns. 2653 * Typically there is only one action for each rule, 2654 * and the opcode is stored at the end of the rule 2655 * (but there are exceptions -- see below). 2656 * 2657 * In general, here we set retval and terminate the 2658 * outer loop (would be a 'break 3' in some language, 2659 * but we need to set l=0, done=1) 2660 * 2661 * Exceptions: 2662 * O_COUNT and O_SKIPTO actions: 2663 * instead of terminating, we jump to the next rule 2664 * (setting l=0), or to the SKIPTO target (setting 2665 * f/f_len, cmd and l as needed), respectively. 2666 * 2667 * O_TAG, O_LOG and O_ALTQ action parameters: 2668 * perform some action and set match = 1; 2669 * 2670 * O_LIMIT and O_KEEP_STATE: these opcodes are 2671 * not real 'actions', and are stored right 2672 * before the 'action' part of the rule (one 2673 * exception is O_SKIP_ACTION which could be 2674 * between these opcodes and 'action' one). 2675 * These opcodes try to install an entry in the 2676 * state tables; if successful, we continue with 2677 * the next opcode (match=1; break;), otherwise 2678 * the packet must be dropped (set retval, 2679 * break loops with l=0, done=1) 2680 * 2681 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2682 * cause a lookup of the state table, and a jump 2683 * to the 'action' part of the parent rule 2684 * if an entry is found, or 2685 * (CHECK_STATE only) a jump to the next rule if 2686 * the entry is not found. 2687 * The result of the lookup is cached so that 2688 * further instances of these opcodes become NOPs. 2689 * The jump to the next rule is done by setting 2690 * l=0, cmdlen=0. 2691 * 2692 * O_SKIP_ACTION: this opcode is not a real 'action' 2693 * either, and is stored right before the 'action' 2694 * part of the rule, right after the O_KEEP_STATE 2695 * opcode. It causes match failure so the real 2696 * 'action' could be executed only if the rule 2697 * is checked via dynamic rule from the state 2698 * table, as in such case execution starts 2699 * from the true 'action' opcode directly. 2700 * 2701 */ 2702 case O_LIMIT: 2703 case O_KEEP_STATE: 2704 if (ipfw_dyn_install_state(chain, f, 2705 (ipfw_insn_limit *)cmd, args, ulp, 2706 pktlen, &dyn_info, tablearg)) { 2707 /* error or limit violation */ 2708 retval = IP_FW_DENY; 2709 l = 0; /* exit inner loop */ 2710 done = 1; /* exit outer loop */ 2711 } 2712 match = 1; 2713 break; 2714 2715 case O_PROBE_STATE: 2716 case O_CHECK_STATE: 2717 /* 2718 * dynamic rules are checked at the first 2719 * keep-state or check-state occurrence, 2720 * with the result being stored in dyn_info. 2721 * The compiler introduces a PROBE_STATE 2722 * instruction for us when we have a 2723 * KEEP_STATE (because PROBE_STATE needs 2724 * to be run first). 2725 */ 2726 if (DYN_LOOKUP_NEEDED(&dyn_info, cmd) && 2727 (q = ipfw_dyn_lookup_state(args, ulp, 2728 pktlen, cmd, &dyn_info)) != NULL) { 2729 /* 2730 * Found dynamic entry, jump to the 2731 * 'action' part of the parent rule 2732 * by setting f, cmd, l and clearing 2733 * cmdlen. 2734 */ 2735 f = q; 2736 f_pos = dyn_info.f_pos; 2737 cmd = ACTION_PTR(f); 2738 l = f->cmd_len - f->act_ofs; 2739 cmdlen = 0; 2740 match = 1; 2741 break; 2742 } 2743 /* 2744 * Dynamic entry not found. If CHECK_STATE, 2745 * skip to next rule, if PROBE_STATE just 2746 * ignore and continue with next opcode. 2747 */ 2748 if (cmd->opcode == O_CHECK_STATE) 2749 l = 0; /* exit inner loop */ 2750 match = 1; 2751 break; 2752 2753 case O_SKIP_ACTION: 2754 match = 0; /* skip to the next rule */ 2755 l = 0; /* exit inner loop */ 2756 break; 2757 2758 case O_ACCEPT: 2759 retval = 0; /* accept */ 2760 l = 0; /* exit inner loop */ 2761 done = 1; /* exit outer loop */ 2762 break; 2763 2764 case O_PIPE: 2765 case O_QUEUE: 2766 set_match(args, f_pos, chain); 2767 args->rule.info = TARG(cmd->arg1, pipe); 2768 if (cmd->opcode == O_PIPE) 2769 args->rule.info |= IPFW_IS_PIPE; 2770 if (V_fw_one_pass) 2771 args->rule.info |= IPFW_ONEPASS; 2772 retval = IP_FW_DUMMYNET; 2773 l = 0; /* exit inner loop */ 2774 done = 1; /* exit outer loop */ 2775 break; 2776 2777 case O_DIVERT: 2778 case O_TEE: 2779 if (args->flags & IPFW_ARGS_ETHER) 2780 break; /* not on layer 2 */ 2781 /* otherwise this is terminal */ 2782 l = 0; /* exit inner loop */ 2783 done = 1; /* exit outer loop */ 2784 retval = (cmd->opcode == O_DIVERT) ? 2785 IP_FW_DIVERT : IP_FW_TEE; 2786 set_match(args, f_pos, chain); 2787 args->rule.info = TARG(cmd->arg1, divert); 2788 break; 2789 2790 case O_COUNT: 2791 IPFW_INC_RULE_COUNTER(f, pktlen); 2792 l = 0; /* exit inner loop */ 2793 break; 2794 2795 case O_SKIPTO: 2796 IPFW_INC_RULE_COUNTER(f, pktlen); 2797 f_pos = JUMP(chain, f, cmd->arg1, tablearg, 0); 2798 /* 2799 * Skip disabled rules, and re-enter 2800 * the inner loop with the correct 2801 * f_pos, f, l and cmd. 2802 * Also clear cmdlen and skip_or 2803 */ 2804 for (; f_pos < chain->n_rules - 1 && 2805 (V_set_disable & 2806 (1 << chain->map[f_pos]->set)); 2807 f_pos++) 2808 ; 2809 /* Re-enter the inner loop at the skipto rule. */ 2810 f = chain->map[f_pos]; 2811 l = f->cmd_len; 2812 cmd = f->cmd; 2813 match = 1; 2814 cmdlen = 0; 2815 skip_or = 0; 2816 continue; 2817 break; /* not reached */ 2818 2819 case O_CALLRETURN: { 2820 /* 2821 * Implementation of `subroutine' call/return, 2822 * in the stack carried in an mbuf tag. This 2823 * is different from `skipto' in that any call 2824 * address is possible (`skipto' must prevent 2825 * backward jumps to avoid endless loops). 2826 * We have `return' action when F_NOT flag is 2827 * present. The `m_tag_id' field is used as 2828 * stack pointer. 2829 */ 2830 struct m_tag *mtag; 2831 uint16_t jmpto, *stack; 2832 2833 #define IS_CALL ((cmd->len & F_NOT) == 0) 2834 #define IS_RETURN ((cmd->len & F_NOT) != 0) 2835 /* 2836 * Hand-rolled version of m_tag_locate() with 2837 * wildcard `type'. 2838 * If not already tagged, allocate new tag. 2839 */ 2840 mtag = m_tag_first(m); 2841 while (mtag != NULL) { 2842 if (mtag->m_tag_cookie == 2843 MTAG_IPFW_CALL) 2844 break; 2845 mtag = m_tag_next(m, mtag); 2846 } 2847 if (mtag == NULL && IS_CALL) { 2848 mtag = m_tag_alloc(MTAG_IPFW_CALL, 0, 2849 IPFW_CALLSTACK_SIZE * 2850 sizeof(uint16_t), M_NOWAIT); 2851 if (mtag != NULL) 2852 m_tag_prepend(m, mtag); 2853 } 2854 2855 /* 2856 * On error both `call' and `return' just 2857 * continue with next rule. 2858 */ 2859 if (IS_RETURN && (mtag == NULL || 2860 mtag->m_tag_id == 0)) { 2861 l = 0; /* exit inner loop */ 2862 break; 2863 } 2864 if (IS_CALL && (mtag == NULL || 2865 mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) { 2866 printf("ipfw: call stack error, " 2867 "go to next rule\n"); 2868 l = 0; /* exit inner loop */ 2869 break; 2870 } 2871 2872 IPFW_INC_RULE_COUNTER(f, pktlen); 2873 stack = (uint16_t *)(mtag + 1); 2874 2875 /* 2876 * The `call' action may use cached f_pos 2877 * (in f->next_rule), whose version is written 2878 * in f->next_rule. 2879 * The `return' action, however, doesn't have 2880 * fixed jump address in cmd->arg1 and can't use 2881 * cache. 2882 */ 2883 if (IS_CALL) { 2884 stack[mtag->m_tag_id] = f->rulenum; 2885 mtag->m_tag_id++; 2886 f_pos = JUMP(chain, f, cmd->arg1, 2887 tablearg, 1); 2888 } else { /* `return' action */ 2889 mtag->m_tag_id--; 2890 jmpto = stack[mtag->m_tag_id] + 1; 2891 f_pos = ipfw_find_rule(chain, jmpto, 0); 2892 } 2893 2894 /* 2895 * Skip disabled rules, and re-enter 2896 * the inner loop with the correct 2897 * f_pos, f, l and cmd. 2898 * Also clear cmdlen and skip_or 2899 */ 2900 for (; f_pos < chain->n_rules - 1 && 2901 (V_set_disable & 2902 (1 << chain->map[f_pos]->set)); f_pos++) 2903 ; 2904 /* Re-enter the inner loop at the dest rule. */ 2905 f = chain->map[f_pos]; 2906 l = f->cmd_len; 2907 cmd = f->cmd; 2908 cmdlen = 0; 2909 skip_or = 0; 2910 continue; 2911 break; /* NOTREACHED */ 2912 } 2913 #undef IS_CALL 2914 #undef IS_RETURN 2915 2916 case O_REJECT: 2917 /* 2918 * Drop the packet and send a reject notice 2919 * if the packet is not ICMP (or is an ICMP 2920 * query), and it is not multicast/broadcast. 2921 */ 2922 if (hlen > 0 && is_ipv4 && offset == 0 && 2923 (proto != IPPROTO_ICMP || 2924 is_icmp_query(ICMP(ulp))) && 2925 !(m->m_flags & (M_BCAST|M_MCAST)) && 2926 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 2927 send_reject(args, cmd->arg1, iplen, ip); 2928 m = args->m; 2929 } 2930 /* FALLTHROUGH */ 2931 #ifdef INET6 2932 case O_UNREACH6: 2933 if (hlen > 0 && is_ipv6 && 2934 ((offset & IP6F_OFF_MASK) == 0) && 2935 (proto != IPPROTO_ICMPV6 || 2936 (is_icmp6_query(icmp6_type) == 1)) && 2937 !(m->m_flags & (M_BCAST|M_MCAST)) && 2938 !IN6_IS_ADDR_MULTICAST( 2939 &args->f_id.dst_ip6)) { 2940 send_reject6(args, 2941 cmd->opcode == O_REJECT ? 2942 map_icmp_unreach(cmd->arg1): 2943 cmd->arg1, hlen, 2944 (struct ip6_hdr *)ip); 2945 m = args->m; 2946 } 2947 /* FALLTHROUGH */ 2948 #endif 2949 case O_DENY: 2950 retval = IP_FW_DENY; 2951 l = 0; /* exit inner loop */ 2952 done = 1; /* exit outer loop */ 2953 break; 2954 2955 case O_FORWARD_IP: 2956 if (args->flags & IPFW_ARGS_ETHER) 2957 break; /* not valid on layer2 pkts */ 2958 if (q != f || 2959 dyn_info.direction == MATCH_FORWARD) { 2960 struct sockaddr_in *sa; 2961 2962 sa = &(((ipfw_insn_sa *)cmd)->sa); 2963 if (sa->sin_addr.s_addr == INADDR_ANY) { 2964 #ifdef INET6 2965 /* 2966 * We use O_FORWARD_IP opcode for 2967 * fwd rule with tablearg, but tables 2968 * now support IPv6 addresses. And 2969 * when we are inspecting IPv6 packet, 2970 * we can use nh6 field from 2971 * table_value as next_hop6 address. 2972 */ 2973 if (is_ipv6) { 2974 struct ip_fw_nh6 *nh6; 2975 2976 args->flags |= IPFW_ARGS_NH6; 2977 nh6 = &args->hopstore6; 2978 nh6->sin6_addr = TARG_VAL( 2979 chain, tablearg, nh6); 2980 nh6->sin6_port = sa->sin_port; 2981 nh6->sin6_scope_id = TARG_VAL( 2982 chain, tablearg, zoneid); 2983 } else 2984 #endif 2985 { 2986 args->flags |= IPFW_ARGS_NH4; 2987 args->hopstore.sin_port = 2988 sa->sin_port; 2989 sa = &args->hopstore; 2990 sa->sin_family = AF_INET; 2991 sa->sin_len = sizeof(*sa); 2992 sa->sin_addr.s_addr = htonl( 2993 TARG_VAL(chain, tablearg, 2994 nh4)); 2995 } 2996 } else { 2997 args->flags |= IPFW_ARGS_NH4PTR; 2998 args->next_hop = sa; 2999 } 3000 } 3001 retval = IP_FW_PASS; 3002 l = 0; /* exit inner loop */ 3003 done = 1; /* exit outer loop */ 3004 break; 3005 3006 #ifdef INET6 3007 case O_FORWARD_IP6: 3008 if (args->flags & IPFW_ARGS_ETHER) 3009 break; /* not valid on layer2 pkts */ 3010 if (q != f || 3011 dyn_info.direction == MATCH_FORWARD) { 3012 struct sockaddr_in6 *sin6; 3013 3014 sin6 = &(((ipfw_insn_sa6 *)cmd)->sa); 3015 args->flags |= IPFW_ARGS_NH6PTR; 3016 args->next_hop6 = sin6; 3017 } 3018 retval = IP_FW_PASS; 3019 l = 0; /* exit inner loop */ 3020 done = 1; /* exit outer loop */ 3021 break; 3022 #endif 3023 3024 case O_NETGRAPH: 3025 case O_NGTEE: 3026 set_match(args, f_pos, chain); 3027 args->rule.info = TARG(cmd->arg1, netgraph); 3028 if (V_fw_one_pass) 3029 args->rule.info |= IPFW_ONEPASS; 3030 retval = (cmd->opcode == O_NETGRAPH) ? 3031 IP_FW_NETGRAPH : IP_FW_NGTEE; 3032 l = 0; /* exit inner loop */ 3033 done = 1; /* exit outer loop */ 3034 break; 3035 3036 case O_SETFIB: { 3037 uint32_t fib; 3038 3039 IPFW_INC_RULE_COUNTER(f, pktlen); 3040 fib = TARG(cmd->arg1, fib) & 0x7FFF; 3041 if (fib >= rt_numfibs) 3042 fib = 0; 3043 M_SETFIB(m, fib); 3044 args->f_id.fib = fib; /* XXX */ 3045 l = 0; /* exit inner loop */ 3046 break; 3047 } 3048 3049 case O_SETDSCP: { 3050 uint16_t code; 3051 3052 code = TARG(cmd->arg1, dscp) & 0x3F; 3053 l = 0; /* exit inner loop */ 3054 if (is_ipv4) { 3055 uint16_t old; 3056 3057 old = *(uint16_t *)ip; 3058 ip->ip_tos = (code << 2) | 3059 (ip->ip_tos & 0x03); 3060 ip->ip_sum = cksum_adjust(ip->ip_sum, 3061 old, *(uint16_t *)ip); 3062 } else if (is_ipv6) { 3063 uint8_t *v; 3064 3065 v = &((struct ip6_hdr *)ip)->ip6_vfc; 3066 *v = (*v & 0xF0) | (code >> 2); 3067 v++; 3068 *v = (*v & 0x3F) | ((code & 0x03) << 6); 3069 } else 3070 break; 3071 3072 IPFW_INC_RULE_COUNTER(f, pktlen); 3073 break; 3074 } 3075 3076 case O_NAT: 3077 l = 0; /* exit inner loop */ 3078 done = 1; /* exit outer loop */ 3079 /* 3080 * Ensure that we do not invoke NAT handler for 3081 * non IPv4 packets. Libalias expects only IPv4. 3082 */ 3083 if (!is_ipv4 || !IPFW_NAT_LOADED) { 3084 retval = IP_FW_DENY; 3085 break; 3086 } 3087 3088 struct cfg_nat *t; 3089 int nat_id; 3090 3091 args->rule.info = 0; 3092 set_match(args, f_pos, chain); 3093 /* Check if this is 'global' nat rule */ 3094 if (cmd->arg1 == IP_FW_NAT44_GLOBAL) { 3095 retval = ipfw_nat_ptr(args, NULL, m); 3096 break; 3097 } 3098 t = ((ipfw_insn_nat *)cmd)->nat; 3099 if (t == NULL) { 3100 nat_id = TARG(cmd->arg1, nat); 3101 t = (*lookup_nat_ptr)(&chain->nat, nat_id); 3102 3103 if (t == NULL) { 3104 retval = IP_FW_DENY; 3105 break; 3106 } 3107 if (cmd->arg1 != IP_FW_TARG) 3108 ((ipfw_insn_nat *)cmd)->nat = t; 3109 } 3110 retval = ipfw_nat_ptr(args, t, m); 3111 break; 3112 3113 case O_REASS: { 3114 int ip_off; 3115 3116 l = 0; /* in any case exit inner loop */ 3117 if (is_ipv6) /* IPv6 is not supported yet */ 3118 break; 3119 IPFW_INC_RULE_COUNTER(f, pktlen); 3120 ip_off = ntohs(ip->ip_off); 3121 3122 /* if not fragmented, go to next rule */ 3123 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0) 3124 break; 3125 3126 args->m = m = ip_reass(m); 3127 3128 /* 3129 * do IP header checksum fixup. 3130 */ 3131 if (m == NULL) { /* fragment got swallowed */ 3132 retval = IP_FW_DENY; 3133 } else { /* good, packet complete */ 3134 int hlen; 3135 3136 ip = mtod(m, struct ip *); 3137 hlen = ip->ip_hl << 2; 3138 ip->ip_sum = 0; 3139 if (hlen == sizeof(struct ip)) 3140 ip->ip_sum = in_cksum_hdr(ip); 3141 else 3142 ip->ip_sum = in_cksum(m, hlen); 3143 retval = IP_FW_REASS; 3144 args->rule.info = 0; 3145 set_match(args, f_pos, chain); 3146 } 3147 done = 1; /* exit outer loop */ 3148 break; 3149 } 3150 case O_EXTERNAL_ACTION: 3151 l = 0; /* in any case exit inner loop */ 3152 retval = ipfw_run_eaction(chain, args, 3153 cmd, &done); 3154 /* 3155 * If both @retval and @done are zero, 3156 * consider this as rule matching and 3157 * update counters. 3158 */ 3159 if (retval == 0 && done == 0) { 3160 IPFW_INC_RULE_COUNTER(f, pktlen); 3161 /* 3162 * Reset the result of the last 3163 * dynamic state lookup. 3164 * External action can change 3165 * @args content, and it may be 3166 * used for new state lookup later. 3167 */ 3168 DYN_INFO_INIT(&dyn_info); 3169 } 3170 break; 3171 3172 default: 3173 panic("-- unknown opcode %d\n", cmd->opcode); 3174 } /* end of switch() on opcodes */ 3175 /* 3176 * if we get here with l=0, then match is irrelevant. 3177 */ 3178 3179 if (cmd->len & F_NOT) 3180 match = !match; 3181 3182 if (match) { 3183 if (cmd->len & F_OR) 3184 skip_or = 1; 3185 } else { 3186 if (!(cmd->len & F_OR)) /* not an OR block, */ 3187 break; /* try next rule */ 3188 } 3189 3190 } /* end of inner loop, scan opcodes */ 3191 #undef PULLUP_LEN 3192 #undef PULLUP_LEN_LOCKED 3193 3194 if (done) 3195 break; 3196 3197 /* next_rule:; */ /* try next rule */ 3198 3199 } /* end of outer for, scan rules */ 3200 3201 if (done) { 3202 struct ip_fw *rule = chain->map[f_pos]; 3203 /* Update statistics */ 3204 IPFW_INC_RULE_COUNTER(rule, pktlen); 3205 } else { 3206 retval = IP_FW_DENY; 3207 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 3208 } 3209 IPFW_PF_RUNLOCK(chain); 3210 #ifdef __FreeBSD__ 3211 if (ucred_cache != NULL) 3212 crfree(ucred_cache); 3213 #endif 3214 return (retval); 3215 3216 pullup_failed: 3217 if (V_fw_verbose) 3218 printf("ipfw: pullup failed\n"); 3219 return (IP_FW_DENY); 3220 } 3221 3222 /* 3223 * Set maximum number of tables that can be used in given VNET ipfw instance. 3224 */ 3225 #ifdef SYSCTL_NODE 3226 static int 3227 sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS) 3228 { 3229 int error; 3230 unsigned int ntables; 3231 3232 ntables = V_fw_tables_max; 3233 3234 error = sysctl_handle_int(oidp, &ntables, 0, req); 3235 /* Read operation or some error */ 3236 if ((error != 0) || (req->newptr == NULL)) 3237 return (error); 3238 3239 return (ipfw_resize_tables(&V_layer3_chain, ntables)); 3240 } 3241 3242 /* 3243 * Switches table namespace between global and per-set. 3244 */ 3245 static int 3246 sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS) 3247 { 3248 int error; 3249 unsigned int sets; 3250 3251 sets = V_fw_tables_sets; 3252 3253 error = sysctl_handle_int(oidp, &sets, 0, req); 3254 /* Read operation or some error */ 3255 if ((error != 0) || (req->newptr == NULL)) 3256 return (error); 3257 3258 return (ipfw_switch_tables_namespace(&V_layer3_chain, sets)); 3259 } 3260 #endif 3261 3262 /* 3263 * Module and VNET glue 3264 */ 3265 3266 /* 3267 * Stuff that must be initialised only on boot or module load 3268 */ 3269 static int 3270 ipfw_init(void) 3271 { 3272 int error = 0; 3273 3274 /* 3275 * Only print out this stuff the first time around, 3276 * when called from the sysinit code. 3277 */ 3278 printf("ipfw2 " 3279 #ifdef INET6 3280 "(+ipv6) " 3281 #endif 3282 "initialized, divert %s, nat %s, " 3283 "default to %s, logging ", 3284 #ifdef IPDIVERT 3285 "enabled", 3286 #else 3287 "loadable", 3288 #endif 3289 #ifdef IPFIREWALL_NAT 3290 "enabled", 3291 #else 3292 "loadable", 3293 #endif 3294 default_to_accept ? "accept" : "deny"); 3295 3296 /* 3297 * Note: V_xxx variables can be accessed here but the vnet specific 3298 * initializer may not have been called yet for the VIMAGE case. 3299 * Tuneables will have been processed. We will print out values for 3300 * the default vnet. 3301 * XXX This should all be rationalized AFTER 8.0 3302 */ 3303 if (V_fw_verbose == 0) 3304 printf("disabled\n"); 3305 else if (V_verbose_limit == 0) 3306 printf("unlimited\n"); 3307 else 3308 printf("limited to %d packets/entry by default\n", 3309 V_verbose_limit); 3310 3311 /* Check user-supplied table count for validness */ 3312 if (default_fw_tables > IPFW_TABLES_MAX) 3313 default_fw_tables = IPFW_TABLES_MAX; 3314 3315 ipfw_init_sopt_handler(); 3316 ipfw_init_obj_rewriter(); 3317 ipfw_iface_init(); 3318 return (error); 3319 } 3320 3321 /* 3322 * Called for the removal of the last instance only on module unload. 3323 */ 3324 static void 3325 ipfw_destroy(void) 3326 { 3327 3328 ipfw_iface_destroy(); 3329 ipfw_destroy_sopt_handler(); 3330 ipfw_destroy_obj_rewriter(); 3331 printf("IP firewall unloaded\n"); 3332 } 3333 3334 /* 3335 * Stuff that must be initialized for every instance 3336 * (including the first of course). 3337 */ 3338 static int 3339 vnet_ipfw_init(const void *unused) 3340 { 3341 int error, first; 3342 struct ip_fw *rule = NULL; 3343 struct ip_fw_chain *chain; 3344 3345 chain = &V_layer3_chain; 3346 3347 first = IS_DEFAULT_VNET(curvnet) ? 1 : 0; 3348 3349 /* First set up some values that are compile time options */ 3350 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 3351 V_fw_deny_unknown_exthdrs = 1; 3352 #ifdef IPFIREWALL_VERBOSE 3353 V_fw_verbose = 1; 3354 #endif 3355 #ifdef IPFIREWALL_VERBOSE_LIMIT 3356 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 3357 #endif 3358 #ifdef IPFIREWALL_NAT 3359 LIST_INIT(&chain->nat); 3360 #endif 3361 3362 /* Init shared services hash table */ 3363 ipfw_init_srv(chain); 3364 3365 ipfw_init_counters(); 3366 /* Set initial number of tables */ 3367 V_fw_tables_max = default_fw_tables; 3368 error = ipfw_init_tables(chain, first); 3369 if (error) { 3370 printf("ipfw2: setting up tables failed\n"); 3371 free(chain->map, M_IPFW); 3372 free(rule, M_IPFW); 3373 return (ENOSPC); 3374 } 3375 3376 IPFW_LOCK_INIT(chain); 3377 3378 /* fill and insert the default rule */ 3379 rule = ipfw_alloc_rule(chain, sizeof(struct ip_fw)); 3380 rule->flags |= IPFW_RULE_NOOPT; 3381 rule->cmd_len = 1; 3382 rule->cmd[0].len = 1; 3383 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY; 3384 chain->default_rule = rule; 3385 ipfw_add_protected_rule(chain, rule, 0); 3386 3387 ipfw_dyn_init(chain); 3388 ipfw_eaction_init(chain, first); 3389 #ifdef LINEAR_SKIPTO 3390 ipfw_init_skipto_cache(chain); 3391 #endif 3392 ipfw_bpf_init(first); 3393 3394 /* First set up some values that are compile time options */ 3395 V_ipfw_vnet_ready = 1; /* Open for business */ 3396 3397 /* 3398 * Hook the sockopt handler and pfil hooks for ipv4 and ipv6. 3399 * Even if the latter two fail we still keep the module alive 3400 * because the sockopt and layer2 paths are still useful. 3401 * ipfw[6]_hook return 0 on success, ENOENT on failure, 3402 * so we can ignore the exact return value and just set a flag. 3403 * 3404 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so 3405 * changes in the underlying (per-vnet) variables trigger 3406 * immediate hook()/unhook() calls. 3407 * In layer2 we have the same behaviour, except that V_ether_ipfw 3408 * is checked on each packet because there are no pfil hooks. 3409 */ 3410 V_ip_fw_ctl_ptr = ipfw_ctl3; 3411 error = ipfw_attach_hooks(); 3412 return (error); 3413 } 3414 3415 /* 3416 * Called for the removal of each instance. 3417 */ 3418 static int 3419 vnet_ipfw_uninit(const void *unused) 3420 { 3421 struct ip_fw *reap; 3422 struct ip_fw_chain *chain = &V_layer3_chain; 3423 int i, last; 3424 3425 V_ipfw_vnet_ready = 0; /* tell new callers to go away */ 3426 /* 3427 * disconnect from ipv4, ipv6, layer2 and sockopt. 3428 * Then grab, release and grab again the WLOCK so we make 3429 * sure the update is propagated and nobody will be in. 3430 */ 3431 ipfw_detach_hooks(); 3432 V_ip_fw_ctl_ptr = NULL; 3433 3434 last = IS_DEFAULT_VNET(curvnet) ? 1 : 0; 3435 3436 IPFW_UH_WLOCK(chain); 3437 IPFW_UH_WUNLOCK(chain); 3438 3439 ipfw_dyn_uninit(0); /* run the callout_drain */ 3440 3441 IPFW_UH_WLOCK(chain); 3442 3443 reap = NULL; 3444 IPFW_WLOCK(chain); 3445 for (i = 0; i < chain->n_rules; i++) 3446 ipfw_reap_add(chain, &reap, chain->map[i]); 3447 free(chain->map, M_IPFW); 3448 #ifdef LINEAR_SKIPTO 3449 ipfw_destroy_skipto_cache(chain); 3450 #endif 3451 IPFW_WUNLOCK(chain); 3452 IPFW_UH_WUNLOCK(chain); 3453 ipfw_destroy_tables(chain, last); 3454 ipfw_eaction_uninit(chain, last); 3455 if (reap != NULL) 3456 ipfw_reap_rules(reap); 3457 vnet_ipfw_iface_destroy(chain); 3458 ipfw_destroy_srv(chain); 3459 IPFW_LOCK_DESTROY(chain); 3460 ipfw_dyn_uninit(1); /* free the remaining parts */ 3461 ipfw_destroy_counters(); 3462 ipfw_bpf_uninit(last); 3463 return (0); 3464 } 3465 3466 /* 3467 * Module event handler. 3468 * In general we have the choice of handling most of these events by the 3469 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to 3470 * use the SYSINIT handlers as they are more capable of expressing the 3471 * flow of control during module and vnet operations, so this is just 3472 * a skeleton. Note there is no SYSINIT equivalent of the module 3473 * SHUTDOWN handler, but we don't have anything to do in that case anyhow. 3474 */ 3475 static int 3476 ipfw_modevent(module_t mod, int type, void *unused) 3477 { 3478 int err = 0; 3479 3480 switch (type) { 3481 case MOD_LOAD: 3482 /* Called once at module load or 3483 * system boot if compiled in. */ 3484 break; 3485 case MOD_QUIESCE: 3486 /* Called before unload. May veto unloading. */ 3487 break; 3488 case MOD_UNLOAD: 3489 /* Called during unload. */ 3490 break; 3491 case MOD_SHUTDOWN: 3492 /* Called during system shutdown. */ 3493 break; 3494 default: 3495 err = EOPNOTSUPP; 3496 break; 3497 } 3498 return err; 3499 } 3500 3501 static moduledata_t ipfwmod = { 3502 "ipfw", 3503 ipfw_modevent, 3504 0 3505 }; 3506 3507 /* Define startup order. */ 3508 #define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_FIREWALL 3509 #define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */ 3510 #define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */ 3511 #define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */ 3512 3513 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER); 3514 FEATURE(ipfw_ctl3, "ipfw new sockopt calls"); 3515 MODULE_VERSION(ipfw, 3); 3516 /* should declare some dependencies here */ 3517 3518 /* 3519 * Starting up. Done in order after ipfwmod() has been called. 3520 * VNET_SYSINIT is also called for each existing vnet and each new vnet. 3521 */ 3522 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 3523 ipfw_init, NULL); 3524 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 3525 vnet_ipfw_init, NULL); 3526 3527 /* 3528 * Closing up shop. These are done in REVERSE ORDER, but still 3529 * after ipfwmod() has been called. Not called on reboot. 3530 * VNET_SYSUNINIT is also called for each exiting vnet as it exits. 3531 * or when the module is unloaded. 3532 */ 3533 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 3534 ipfw_destroy, NULL); 3535 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 3536 vnet_ipfw_uninit, NULL); 3537 /* end of file */ 3538