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 UPDATE_POINTERS() 1470 /* 1471 * In case pointers got stale after pullups, update them. 1472 */ 1473 #define UPDATE_POINTERS() \ 1474 do { \ 1475 if (!mem) { \ 1476 if (eh != NULL) { \ 1477 eh = mtod(m, struct ether_header *); \ 1478 ip = (struct ip *)(eh + 1); \ 1479 } else \ 1480 ip = mtod(m, struct ip *); \ 1481 args->m = m; \ 1482 } \ 1483 } while (0) 1484 1485 /* Identify IP packets and fill up variables. */ 1486 if (pktlen >= sizeof(struct ip6_hdr) && 1487 (eh == NULL || eh->ether_type == htons(ETHERTYPE_IPV6)) && 1488 ip->ip_v == 6) { 1489 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 1490 1491 is_ipv6 = 1; 1492 args->flags |= IPFW_ARGS_IP6; 1493 hlen = sizeof(struct ip6_hdr); 1494 proto = ip6->ip6_nxt; 1495 /* Search extension headers to find upper layer protocols */ 1496 while (ulp == NULL && offset == 0) { 1497 switch (proto) { 1498 case IPPROTO_ICMPV6: 1499 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 1500 icmp6_type = ICMP6(ulp)->icmp6_type; 1501 break; 1502 1503 case IPPROTO_TCP: 1504 PULLUP_TO(hlen, ulp, struct tcphdr); 1505 dst_port = TCP(ulp)->th_dport; 1506 src_port = TCP(ulp)->th_sport; 1507 /* save flags for dynamic rules */ 1508 args->f_id._flags = TCP(ulp)->th_flags; 1509 break; 1510 1511 case IPPROTO_SCTP: 1512 if (pktlen >= hlen + sizeof(struct sctphdr) + 1513 sizeof(struct sctp_chunkhdr) + 1514 offsetof(struct sctp_init, a_rwnd)) 1515 PULLUP_LEN(hlen, ulp, 1516 sizeof(struct sctphdr) + 1517 sizeof(struct sctp_chunkhdr) + 1518 offsetof(struct sctp_init, a_rwnd)); 1519 else if (pktlen >= hlen + sizeof(struct sctphdr)) 1520 PULLUP_LEN(hlen, ulp, pktlen - hlen); 1521 else 1522 PULLUP_LEN(hlen, ulp, 1523 sizeof(struct sctphdr)); 1524 src_port = SCTP(ulp)->src_port; 1525 dst_port = SCTP(ulp)->dest_port; 1526 break; 1527 1528 case IPPROTO_UDP: 1529 case IPPROTO_UDPLITE: 1530 PULLUP_TO(hlen, ulp, struct udphdr); 1531 dst_port = UDP(ulp)->uh_dport; 1532 src_port = UDP(ulp)->uh_sport; 1533 break; 1534 1535 case IPPROTO_HOPOPTS: /* RFC 2460 */ 1536 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1537 ext_hd |= EXT_HOPOPTS; 1538 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1539 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1540 ulp = NULL; 1541 break; 1542 1543 case IPPROTO_ROUTING: /* RFC 2460 */ 1544 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 1545 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 1546 case 0: 1547 ext_hd |= EXT_RTHDR0; 1548 break; 1549 case 2: 1550 ext_hd |= EXT_RTHDR2; 1551 break; 1552 default: 1553 if (V_fw_verbose) 1554 printf("IPFW2: IPV6 - Unknown " 1555 "Routing Header type(%d)\n", 1556 ((struct ip6_rthdr *) 1557 ulp)->ip6r_type); 1558 if (V_fw_deny_unknown_exthdrs) 1559 return (IP_FW_DENY); 1560 break; 1561 } 1562 ext_hd |= EXT_ROUTING; 1563 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 1564 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 1565 ulp = NULL; 1566 break; 1567 1568 case IPPROTO_FRAGMENT: /* RFC 2460 */ 1569 PULLUP_TO(hlen, ulp, struct ip6_frag); 1570 ext_hd |= EXT_FRAGMENT; 1571 hlen += sizeof (struct ip6_frag); 1572 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 1573 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 1574 IP6F_OFF_MASK; 1575 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg & 1576 IP6F_MORE_FRAG; 1577 if (V_fw_permit_single_frag6 == 0 && 1578 offset == 0 && ip6f_mf == 0) { 1579 if (V_fw_verbose) 1580 printf("IPFW2: IPV6 - Invalid " 1581 "Fragment Header\n"); 1582 if (V_fw_deny_unknown_exthdrs) 1583 return (IP_FW_DENY); 1584 break; 1585 } 1586 args->f_id.extra = 1587 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 1588 ulp = NULL; 1589 break; 1590 1591 case IPPROTO_DSTOPTS: /* RFC 2460 */ 1592 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1593 ext_hd |= EXT_DSTOPTS; 1594 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1595 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1596 ulp = NULL; 1597 break; 1598 1599 case IPPROTO_AH: /* RFC 2402 */ 1600 PULLUP_TO(hlen, ulp, struct ip6_ext); 1601 ext_hd |= EXT_AH; 1602 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 1603 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 1604 ulp = NULL; 1605 break; 1606 1607 case IPPROTO_ESP: /* RFC 2406 */ 1608 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 1609 /* Anything past Seq# is variable length and 1610 * data past this ext. header is encrypted. */ 1611 ext_hd |= EXT_ESP; 1612 break; 1613 1614 case IPPROTO_NONE: /* RFC 2460 */ 1615 /* 1616 * Packet ends here, and IPv6 header has 1617 * already been pulled up. If ip6e_len!=0 1618 * then octets must be ignored. 1619 */ 1620 ulp = ip; /* non-NULL to get out of loop. */ 1621 break; 1622 1623 case IPPROTO_OSPFIGP: 1624 /* XXX OSPF header check? */ 1625 PULLUP_TO(hlen, ulp, struct ip6_ext); 1626 break; 1627 1628 case IPPROTO_PIM: 1629 /* XXX PIM header check? */ 1630 PULLUP_TO(hlen, ulp, struct pim); 1631 break; 1632 1633 case IPPROTO_GRE: /* RFC 1701 */ 1634 /* XXX GRE header check? */ 1635 PULLUP_TO(hlen, ulp, struct grehdr); 1636 break; 1637 1638 case IPPROTO_CARP: 1639 PULLUP_TO(hlen, ulp, offsetof( 1640 struct carp_header, carp_counter)); 1641 if (CARP_ADVERTISEMENT != 1642 ((struct carp_header *)ulp)->carp_type) 1643 return (IP_FW_DENY); 1644 break; 1645 1646 case IPPROTO_IPV6: /* RFC 2893 */ 1647 PULLUP_TO(hlen, ulp, struct ip6_hdr); 1648 break; 1649 1650 case IPPROTO_IPV4: /* RFC 2893 */ 1651 PULLUP_TO(hlen, ulp, struct ip); 1652 break; 1653 1654 default: 1655 if (V_fw_verbose) 1656 printf("IPFW2: IPV6 - Unknown " 1657 "Extension Header(%d), ext_hd=%x\n", 1658 proto, ext_hd); 1659 if (V_fw_deny_unknown_exthdrs) 1660 return (IP_FW_DENY); 1661 PULLUP_TO(hlen, ulp, struct ip6_ext); 1662 break; 1663 } /*switch */ 1664 } 1665 UPDATE_POINTERS(); 1666 ip6 = (struct ip6_hdr *)ip; 1667 args->f_id.addr_type = 6; 1668 args->f_id.src_ip6 = ip6->ip6_src; 1669 args->f_id.dst_ip6 = ip6->ip6_dst; 1670 args->f_id.flow_id6 = ntohl(ip6->ip6_flow); 1671 iplen = ntohs(ip6->ip6_plen) + sizeof(*ip6); 1672 } else if (pktlen >= sizeof(struct ip) && 1673 (eh == NULL || eh->ether_type == htons(ETHERTYPE_IP)) && 1674 ip->ip_v == 4) { 1675 is_ipv4 = 1; 1676 args->flags |= IPFW_ARGS_IP4; 1677 hlen = ip->ip_hl << 2; 1678 /* 1679 * Collect parameters into local variables for faster 1680 * matching. 1681 */ 1682 proto = ip->ip_p; 1683 src_ip = ip->ip_src; 1684 dst_ip = ip->ip_dst; 1685 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1686 iplen = ntohs(ip->ip_len); 1687 1688 if (offset == 0) { 1689 switch (proto) { 1690 case IPPROTO_TCP: 1691 PULLUP_TO(hlen, ulp, struct tcphdr); 1692 dst_port = TCP(ulp)->th_dport; 1693 src_port = TCP(ulp)->th_sport; 1694 /* save flags for dynamic rules */ 1695 args->f_id._flags = TCP(ulp)->th_flags; 1696 break; 1697 1698 case IPPROTO_SCTP: 1699 if (pktlen >= hlen + sizeof(struct sctphdr) + 1700 sizeof(struct sctp_chunkhdr) + 1701 offsetof(struct sctp_init, a_rwnd)) 1702 PULLUP_LEN(hlen, ulp, 1703 sizeof(struct sctphdr) + 1704 sizeof(struct sctp_chunkhdr) + 1705 offsetof(struct sctp_init, a_rwnd)); 1706 else if (pktlen >= hlen + sizeof(struct sctphdr)) 1707 PULLUP_LEN(hlen, ulp, pktlen - hlen); 1708 else 1709 PULLUP_LEN(hlen, ulp, 1710 sizeof(struct sctphdr)); 1711 src_port = SCTP(ulp)->src_port; 1712 dst_port = SCTP(ulp)->dest_port; 1713 break; 1714 1715 case IPPROTO_UDP: 1716 case IPPROTO_UDPLITE: 1717 PULLUP_TO(hlen, ulp, struct udphdr); 1718 dst_port = UDP(ulp)->uh_dport; 1719 src_port = UDP(ulp)->uh_sport; 1720 break; 1721 1722 case IPPROTO_ICMP: 1723 PULLUP_TO(hlen, ulp, struct icmphdr); 1724 //args->f_id.flags = ICMP(ulp)->icmp_type; 1725 break; 1726 1727 default: 1728 break; 1729 } 1730 } else { 1731 if (offset == 1 && proto == IPPROTO_TCP) { 1732 /* RFC 3128 */ 1733 goto pullup_failed; 1734 } 1735 } 1736 1737 UPDATE_POINTERS(); 1738 args->f_id.addr_type = 4; 1739 args->f_id.src_ip = ntohl(src_ip.s_addr); 1740 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1741 } else { 1742 proto = 0; 1743 dst_ip.s_addr = src_ip.s_addr = 0; 1744 1745 args->f_id.addr_type = 1; /* XXX */ 1746 } 1747 #undef PULLUP_TO 1748 pktlen = iplen < pktlen ? iplen: pktlen; 1749 1750 /* Properly initialize the rest of f_id */ 1751 args->f_id.proto = proto; 1752 args->f_id.src_port = src_port = ntohs(src_port); 1753 args->f_id.dst_port = dst_port = ntohs(dst_port); 1754 1755 IPFW_PF_RLOCK(chain); 1756 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ 1757 IPFW_PF_RUNLOCK(chain); 1758 return (IP_FW_PASS); /* accept */ 1759 } 1760 if (args->flags & IPFW_ARGS_REF) { 1761 /* 1762 * Packet has already been tagged as a result of a previous 1763 * match on rule args->rule aka args->rule_id (PIPE, QUEUE, 1764 * REASS, NETGRAPH, DIVERT/TEE...) 1765 * Validate the slot and continue from the next one 1766 * if still present, otherwise do a lookup. 1767 */ 1768 f_pos = (args->rule.chain_id == chain->id) ? 1769 args->rule.slot : 1770 ipfw_find_rule(chain, args->rule.rulenum, 1771 args->rule.rule_id); 1772 } else { 1773 f_pos = 0; 1774 } 1775 1776 if (args->flags & IPFW_ARGS_IN) { 1777 iif = args->ifp; 1778 oif = NULL; 1779 } else { 1780 MPASS(args->flags & IPFW_ARGS_OUT); 1781 iif = mem ? NULL : m_rcvif(m); 1782 oif = args->ifp; 1783 } 1784 1785 /* 1786 * Now scan the rules, and parse microinstructions for each rule. 1787 * We have two nested loops and an inner switch. Sometimes we 1788 * need to break out of one or both loops, or re-enter one of 1789 * the loops with updated variables. Loop variables are: 1790 * 1791 * f_pos (outer loop) points to the current rule. 1792 * On output it points to the matching rule. 1793 * done (outer loop) is used as a flag to break the loop. 1794 * l (inner loop) residual length of current rule. 1795 * cmd points to the current microinstruction. 1796 * 1797 * We break the inner loop by setting l=0 and possibly 1798 * cmdlen=0 if we don't want to advance cmd. 1799 * We break the outer loop by setting done=1 1800 * We can restart the inner loop by setting l>0 and f_pos, f, cmd 1801 * as needed. 1802 */ 1803 for (; f_pos < chain->n_rules; f_pos++) { 1804 ipfw_insn *cmd; 1805 uint32_t tablearg = 0; 1806 int l, cmdlen, skip_or; /* skip rest of OR block */ 1807 struct ip_fw *f; 1808 1809 f = chain->map[f_pos]; 1810 if (V_set_disable & (1 << f->set) ) 1811 continue; 1812 1813 skip_or = 0; 1814 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 1815 l -= cmdlen, cmd += cmdlen) { 1816 int match; 1817 1818 /* 1819 * check_body is a jump target used when we find a 1820 * CHECK_STATE, and need to jump to the body of 1821 * the target rule. 1822 */ 1823 1824 /* check_body: */ 1825 cmdlen = F_LEN(cmd); 1826 /* 1827 * An OR block (insn_1 || .. || insn_n) has the 1828 * F_OR bit set in all but the last instruction. 1829 * The first match will set "skip_or", and cause 1830 * the following instructions to be skipped until 1831 * past the one with the F_OR bit clear. 1832 */ 1833 if (skip_or) { /* skip this instruction */ 1834 if ((cmd->len & F_OR) == 0) 1835 skip_or = 0; /* next one is good */ 1836 continue; 1837 } 1838 match = 0; /* set to 1 if we succeed */ 1839 1840 switch (cmd->opcode) { 1841 /* 1842 * The first set of opcodes compares the packet's 1843 * fields with some pattern, setting 'match' if a 1844 * match is found. At the end of the loop there is 1845 * logic to deal with F_NOT and F_OR flags associated 1846 * with the opcode. 1847 */ 1848 case O_NOP: 1849 match = 1; 1850 break; 1851 1852 case O_FORWARD_MAC: 1853 printf("ipfw: opcode %d unimplemented\n", 1854 cmd->opcode); 1855 break; 1856 1857 case O_GID: 1858 case O_UID: 1859 case O_JAIL: 1860 /* 1861 * We only check offset == 0 && proto != 0, 1862 * as this ensures that we have a 1863 * packet with the ports info. 1864 */ 1865 if (offset != 0) 1866 break; 1867 if (proto == IPPROTO_TCP || 1868 proto == IPPROTO_UDP || 1869 proto == IPPROTO_UDPLITE) 1870 match = check_uidgid( 1871 (ipfw_insn_u32 *)cmd, 1872 args, &ucred_lookup, 1873 #ifdef __FreeBSD__ 1874 &ucred_cache); 1875 #else 1876 (void *)&ucred_cache); 1877 #endif 1878 break; 1879 1880 case O_RECV: 1881 match = iface_match(iif, (ipfw_insn_if *)cmd, 1882 chain, &tablearg); 1883 break; 1884 1885 case O_XMIT: 1886 match = iface_match(oif, (ipfw_insn_if *)cmd, 1887 chain, &tablearg); 1888 break; 1889 1890 case O_VIA: 1891 match = iface_match(args->ifp, 1892 (ipfw_insn_if *)cmd, chain, &tablearg); 1893 break; 1894 1895 case O_MACADDR2: 1896 if (args->flags & IPFW_ARGS_ETHER) { 1897 u_int32_t *want = (u_int32_t *) 1898 ((ipfw_insn_mac *)cmd)->addr; 1899 u_int32_t *mask = (u_int32_t *) 1900 ((ipfw_insn_mac *)cmd)->mask; 1901 u_int32_t *hdr = (u_int32_t *)eh; 1902 1903 match = 1904 ( want[0] == (hdr[0] & mask[0]) && 1905 want[1] == (hdr[1] & mask[1]) && 1906 want[2] == (hdr[2] & mask[2]) ); 1907 } 1908 break; 1909 1910 case O_MAC_TYPE: 1911 if (args->flags & IPFW_ARGS_ETHER) { 1912 u_int16_t *p = 1913 ((ipfw_insn_u16 *)cmd)->ports; 1914 int i; 1915 1916 for (i = cmdlen - 1; !match && i>0; 1917 i--, p += 2) 1918 match = 1919 (ntohs(eh->ether_type) >= 1920 p[0] && 1921 ntohs(eh->ether_type) <= 1922 p[1]); 1923 } 1924 break; 1925 1926 case O_FRAG: 1927 match = (offset != 0); 1928 break; 1929 1930 case O_IN: /* "out" is "not in" */ 1931 match = (oif == NULL); 1932 break; 1933 1934 case O_LAYER2: 1935 match = (args->flags & IPFW_ARGS_ETHER); 1936 break; 1937 1938 case O_DIVERTED: 1939 if ((args->flags & IPFW_ARGS_REF) == 0) 1940 break; 1941 /* 1942 * For diverted packets, args->rule.info 1943 * contains the divert port (in host format) 1944 * reason and direction. 1945 */ 1946 match = ((args->rule.info & IPFW_IS_MASK) == 1947 IPFW_IS_DIVERT) && ( 1948 ((args->rule.info & IPFW_INFO_IN) ? 1949 1: 2) & cmd->arg1); 1950 break; 1951 1952 case O_PROTO: 1953 /* 1954 * We do not allow an arg of 0 so the 1955 * check of "proto" only suffices. 1956 */ 1957 match = (proto == cmd->arg1); 1958 break; 1959 1960 case O_IP_SRC: 1961 match = is_ipv4 && 1962 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1963 src_ip.s_addr); 1964 break; 1965 1966 case O_IP_DST_LOOKUP: 1967 { 1968 void *pkey; 1969 uint32_t vidx, key; 1970 uint16_t keylen; 1971 1972 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { 1973 /* Determine lookup key type */ 1974 vidx = ((ipfw_insn_u32 *)cmd)->d[1]; 1975 if (vidx != 4 /* uid */ && 1976 vidx != 5 /* jail */ && 1977 is_ipv6 == 0 && is_ipv4 == 0) 1978 break; 1979 /* Determine key length */ 1980 if (vidx == 0 /* dst-ip */ || 1981 vidx == 1 /* src-ip */) 1982 keylen = is_ipv6 ? 1983 sizeof(struct in6_addr): 1984 sizeof(in_addr_t); 1985 else { 1986 keylen = sizeof(key); 1987 pkey = &key; 1988 } 1989 if (vidx == 0 /* dst-ip */) 1990 pkey = is_ipv4 ? (void *)&dst_ip: 1991 (void *)&args->f_id.dst_ip6; 1992 else if (vidx == 1 /* src-ip */) 1993 pkey = is_ipv4 ? (void *)&src_ip: 1994 (void *)&args->f_id.src_ip6; 1995 else if (vidx == 6 /* dscp */) { 1996 if (is_ipv4) 1997 key = ip->ip_tos >> 2; 1998 else { 1999 key = args->f_id.flow_id6; 2000 key = (key & 0x0f) << 2 | 2001 (key & 0xf000) >> 14; 2002 } 2003 key &= 0x3f; 2004 } else if (vidx == 2 /* dst-port */ || 2005 vidx == 3 /* src-port */) { 2006 /* Skip fragments */ 2007 if (offset != 0) 2008 break; 2009 /* Skip proto without ports */ 2010 if (proto != IPPROTO_TCP && 2011 proto != IPPROTO_UDP && 2012 proto != IPPROTO_UDPLITE && 2013 proto != IPPROTO_SCTP) 2014 break; 2015 if (vidx == 2 /* dst-port */) 2016 key = dst_port; 2017 else 2018 key = src_port; 2019 } 2020 #ifndef USERSPACE 2021 else if (vidx == 4 /* uid */ || 2022 vidx == 5 /* jail */) { 2023 check_uidgid( 2024 (ipfw_insn_u32 *)cmd, 2025 args, &ucred_lookup, 2026 #ifdef __FreeBSD__ 2027 &ucred_cache); 2028 if (vidx == 4 /* uid */) 2029 key = ucred_cache->cr_uid; 2030 else if (vidx == 5 /* jail */) 2031 key = ucred_cache->cr_prison->pr_id; 2032 #else /* !__FreeBSD__ */ 2033 (void *)&ucred_cache); 2034 if (vidx == 4 /* uid */) 2035 key = ucred_cache.uid; 2036 else if (vidx == 5 /* jail */) 2037 key = ucred_cache.xid; 2038 #endif /* !__FreeBSD__ */ 2039 } 2040 #endif /* !USERSPACE */ 2041 else 2042 break; 2043 match = ipfw_lookup_table(chain, 2044 cmd->arg1, keylen, pkey, &vidx); 2045 if (!match) 2046 break; 2047 tablearg = vidx; 2048 break; 2049 } 2050 /* cmdlen =< F_INSN_SIZE(ipfw_insn_u32) */ 2051 /* FALLTHROUGH */ 2052 } 2053 case O_IP_SRC_LOOKUP: 2054 { 2055 void *pkey; 2056 uint32_t vidx; 2057 uint16_t keylen; 2058 2059 if (is_ipv4) { 2060 keylen = sizeof(in_addr_t); 2061 if (cmd->opcode == O_IP_DST_LOOKUP) 2062 pkey = &dst_ip; 2063 else 2064 pkey = &src_ip; 2065 } else if (is_ipv6) { 2066 keylen = sizeof(struct in6_addr); 2067 if (cmd->opcode == O_IP_DST_LOOKUP) 2068 pkey = &args->f_id.dst_ip6; 2069 else 2070 pkey = &args->f_id.src_ip6; 2071 } else 2072 break; 2073 match = ipfw_lookup_table(chain, cmd->arg1, 2074 keylen, pkey, &vidx); 2075 if (!match) 2076 break; 2077 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) { 2078 match = ((ipfw_insn_u32 *)cmd)->d[0] == 2079 TARG_VAL(chain, vidx, tag); 2080 if (!match) 2081 break; 2082 } 2083 tablearg = vidx; 2084 break; 2085 } 2086 2087 case O_IP_FLOW_LOOKUP: 2088 { 2089 uint32_t v = 0; 2090 match = ipfw_lookup_table(chain, 2091 cmd->arg1, 0, &args->f_id, &v); 2092 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 2093 match = ((ipfw_insn_u32 *)cmd)->d[0] == 2094 TARG_VAL(chain, v, tag); 2095 if (match) 2096 tablearg = v; 2097 } 2098 break; 2099 case O_IP_SRC_MASK: 2100 case O_IP_DST_MASK: 2101 if (is_ipv4) { 2102 uint32_t a = 2103 (cmd->opcode == O_IP_DST_MASK) ? 2104 dst_ip.s_addr : src_ip.s_addr; 2105 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 2106 int i = cmdlen-1; 2107 2108 for (; !match && i>0; i-= 2, p+= 2) 2109 match = (p[0] == (a & p[1])); 2110 } 2111 break; 2112 2113 case O_IP_SRC_ME: 2114 if (is_ipv4) { 2115 match = in_localip(src_ip); 2116 break; 2117 } 2118 #ifdef INET6 2119 /* FALLTHROUGH */ 2120 case O_IP6_SRC_ME: 2121 match = is_ipv6 && 2122 ipfw_localip6(&args->f_id.src_ip6); 2123 #endif 2124 break; 2125 2126 case O_IP_DST_SET: 2127 case O_IP_SRC_SET: 2128 if (is_ipv4) { 2129 u_int32_t *d = (u_int32_t *)(cmd+1); 2130 u_int32_t addr = 2131 cmd->opcode == O_IP_DST_SET ? 2132 args->f_id.dst_ip : 2133 args->f_id.src_ip; 2134 2135 if (addr < d[0]) 2136 break; 2137 addr -= d[0]; /* subtract base */ 2138 match = (addr < cmd->arg1) && 2139 ( d[ 1 + (addr>>5)] & 2140 (1<<(addr & 0x1f)) ); 2141 } 2142 break; 2143 2144 case O_IP_DST: 2145 match = is_ipv4 && 2146 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2147 dst_ip.s_addr); 2148 break; 2149 2150 case O_IP_DST_ME: 2151 if (is_ipv4) { 2152 match = in_localip(dst_ip); 2153 break; 2154 } 2155 #ifdef INET6 2156 /* FALLTHROUGH */ 2157 case O_IP6_DST_ME: 2158 match = is_ipv6 && 2159 ipfw_localip6(&args->f_id.dst_ip6); 2160 #endif 2161 break; 2162 2163 2164 case O_IP_SRCPORT: 2165 case O_IP_DSTPORT: 2166 /* 2167 * offset == 0 && proto != 0 is enough 2168 * to guarantee that we have a 2169 * packet with port info. 2170 */ 2171 if ((proto == IPPROTO_UDP || 2172 proto == IPPROTO_UDPLITE || 2173 proto == IPPROTO_TCP || 2174 proto == IPPROTO_SCTP) && offset == 0) { 2175 u_int16_t x = 2176 (cmd->opcode == O_IP_SRCPORT) ? 2177 src_port : dst_port ; 2178 u_int16_t *p = 2179 ((ipfw_insn_u16 *)cmd)->ports; 2180 int i; 2181 2182 for (i = cmdlen - 1; !match && i>0; 2183 i--, p += 2) 2184 match = (x>=p[0] && x<=p[1]); 2185 } 2186 break; 2187 2188 case O_ICMPTYPE: 2189 match = (offset == 0 && proto==IPPROTO_ICMP && 2190 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 2191 break; 2192 2193 #ifdef INET6 2194 case O_ICMP6TYPE: 2195 match = is_ipv6 && offset == 0 && 2196 proto==IPPROTO_ICMPV6 && 2197 icmp6type_match( 2198 ICMP6(ulp)->icmp6_type, 2199 (ipfw_insn_u32 *)cmd); 2200 break; 2201 #endif /* INET6 */ 2202 2203 case O_IPOPT: 2204 match = (is_ipv4 && 2205 ipopts_match(ip, cmd) ); 2206 break; 2207 2208 case O_IPVER: 2209 match = (is_ipv4 && 2210 cmd->arg1 == ip->ip_v); 2211 break; 2212 2213 case O_IPID: 2214 case O_IPTTL: 2215 if (!is_ipv4) 2216 break; 2217 case O_IPLEN: 2218 { /* only for IP packets */ 2219 uint16_t x; 2220 uint16_t *p; 2221 int i; 2222 2223 if (cmd->opcode == O_IPLEN) 2224 x = iplen; 2225 else if (cmd->opcode == O_IPTTL) 2226 x = ip->ip_ttl; 2227 else /* must be IPID */ 2228 x = ntohs(ip->ip_id); 2229 if (cmdlen == 1) { 2230 match = (cmd->arg1 == x); 2231 break; 2232 } 2233 /* otherwise we have ranges */ 2234 p = ((ipfw_insn_u16 *)cmd)->ports; 2235 i = cmdlen - 1; 2236 for (; !match && i>0; i--, p += 2) 2237 match = (x >= p[0] && x <= p[1]); 2238 } 2239 break; 2240 2241 case O_IPPRECEDENCE: 2242 match = (is_ipv4 && 2243 (cmd->arg1 == (ip->ip_tos & 0xe0)) ); 2244 break; 2245 2246 case O_IPTOS: 2247 match = (is_ipv4 && 2248 flags_match(cmd, ip->ip_tos)); 2249 break; 2250 2251 case O_DSCP: 2252 { 2253 uint32_t *p; 2254 uint16_t x; 2255 2256 p = ((ipfw_insn_u32 *)cmd)->d; 2257 2258 if (is_ipv4) 2259 x = ip->ip_tos >> 2; 2260 else if (is_ipv6) { 2261 uint8_t *v; 2262 v = &((struct ip6_hdr *)ip)->ip6_vfc; 2263 x = (*v & 0x0F) << 2; 2264 v++; 2265 x |= *v >> 6; 2266 } else 2267 break; 2268 2269 /* DSCP bitmask is stored as low_u32 high_u32 */ 2270 if (x >= 32) 2271 match = *(p + 1) & (1 << (x - 32)); 2272 else 2273 match = *p & (1 << x); 2274 } 2275 break; 2276 2277 case O_TCPDATALEN: 2278 if (proto == IPPROTO_TCP && offset == 0) { 2279 struct tcphdr *tcp; 2280 uint16_t x; 2281 uint16_t *p; 2282 int i; 2283 #ifdef INET6 2284 if (is_ipv6) { 2285 struct ip6_hdr *ip6; 2286 2287 ip6 = (struct ip6_hdr *)ip; 2288 if (ip6->ip6_plen == 0) { 2289 /* 2290 * Jumbo payload is not 2291 * supported by this 2292 * opcode. 2293 */ 2294 break; 2295 } 2296 x = iplen - hlen; 2297 } else 2298 #endif /* INET6 */ 2299 x = iplen - (ip->ip_hl << 2); 2300 tcp = TCP(ulp); 2301 x -= tcp->th_off << 2; 2302 if (cmdlen == 1) { 2303 match = (cmd->arg1 == x); 2304 break; 2305 } 2306 /* otherwise we have ranges */ 2307 p = ((ipfw_insn_u16 *)cmd)->ports; 2308 i = cmdlen - 1; 2309 for (; !match && i>0; i--, p += 2) 2310 match = (x >= p[0] && x <= p[1]); 2311 } 2312 break; 2313 2314 case O_TCPFLAGS: 2315 match = (proto == IPPROTO_TCP && offset == 0 && 2316 flags_match(cmd, TCP(ulp)->th_flags)); 2317 break; 2318 2319 case O_TCPOPTS: 2320 if (proto == IPPROTO_TCP && offset == 0 && ulp){ 2321 PULLUP_LEN_LOCKED(hlen, ulp, 2322 (TCP(ulp)->th_off << 2)); 2323 match = tcpopts_match(TCP(ulp), cmd); 2324 } 2325 break; 2326 2327 case O_TCPSEQ: 2328 match = (proto == IPPROTO_TCP && offset == 0 && 2329 ((ipfw_insn_u32 *)cmd)->d[0] == 2330 TCP(ulp)->th_seq); 2331 break; 2332 2333 case O_TCPACK: 2334 match = (proto == IPPROTO_TCP && offset == 0 && 2335 ((ipfw_insn_u32 *)cmd)->d[0] == 2336 TCP(ulp)->th_ack); 2337 break; 2338 2339 case O_TCPMSS: 2340 if (proto == IPPROTO_TCP && 2341 (args->f_id._flags & TH_SYN) != 0 && 2342 ulp != NULL) { 2343 uint16_t mss, *p; 2344 int i; 2345 2346 PULLUP_LEN_LOCKED(hlen, ulp, 2347 (TCP(ulp)->th_off << 2)); 2348 if ((tcpopts_parse(TCP(ulp), &mss) & 2349 IP_FW_TCPOPT_MSS) == 0) 2350 break; 2351 if (cmdlen == 1) { 2352 match = (cmd->arg1 == mss); 2353 break; 2354 } 2355 /* Otherwise we have ranges. */ 2356 p = ((ipfw_insn_u16 *)cmd)->ports; 2357 i = cmdlen - 1; 2358 for (; !match && i > 0; i--, p += 2) 2359 match = (mss >= p[0] && 2360 mss <= p[1]); 2361 } 2362 break; 2363 2364 case O_TCPWIN: 2365 if (proto == IPPROTO_TCP && offset == 0) { 2366 uint16_t x; 2367 uint16_t *p; 2368 int i; 2369 2370 x = ntohs(TCP(ulp)->th_win); 2371 if (cmdlen == 1) { 2372 match = (cmd->arg1 == x); 2373 break; 2374 } 2375 /* Otherwise we have ranges. */ 2376 p = ((ipfw_insn_u16 *)cmd)->ports; 2377 i = cmdlen - 1; 2378 for (; !match && i > 0; i--, p += 2) 2379 match = (x >= p[0] && x <= p[1]); 2380 } 2381 break; 2382 2383 case O_ESTAB: 2384 /* reject packets which have SYN only */ 2385 /* XXX should i also check for TH_ACK ? */ 2386 match = (proto == IPPROTO_TCP && offset == 0 && 2387 (TCP(ulp)->th_flags & 2388 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 2389 break; 2390 2391 case O_ALTQ: { 2392 struct pf_mtag *at; 2393 struct m_tag *mtag; 2394 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 2395 2396 /* 2397 * ALTQ uses mbuf tags from another 2398 * packet filtering system - pf(4). 2399 * We allocate a tag in its format 2400 * and fill it in, pretending to be pf(4). 2401 */ 2402 match = 1; 2403 at = pf_find_mtag(m); 2404 if (at != NULL && at->qid != 0) 2405 break; 2406 mtag = m_tag_get(PACKET_TAG_PF, 2407 sizeof(struct pf_mtag), M_NOWAIT | M_ZERO); 2408 if (mtag == NULL) { 2409 /* 2410 * Let the packet fall back to the 2411 * default ALTQ. 2412 */ 2413 break; 2414 } 2415 m_tag_prepend(m, mtag); 2416 at = (struct pf_mtag *)(mtag + 1); 2417 at->qid = altq->qid; 2418 at->hdr = ip; 2419 break; 2420 } 2421 2422 case O_LOG: 2423 ipfw_log(chain, f, hlen, args, 2424 offset | ip6f_mf, tablearg, ip); 2425 match = 1; 2426 break; 2427 2428 case O_PROB: 2429 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 2430 break; 2431 2432 case O_VERREVPATH: 2433 /* Outgoing packets automatically pass/match */ 2434 match = (args->flags & IPFW_ARGS_OUT || 2435 ( 2436 #ifdef INET6 2437 is_ipv6 ? 2438 verify_path6(&(args->f_id.src_ip6), 2439 iif, args->f_id.fib) : 2440 #endif 2441 verify_path(src_ip, iif, args->f_id.fib))); 2442 break; 2443 2444 case O_VERSRCREACH: 2445 /* Outgoing packets automatically pass/match */ 2446 match = (hlen > 0 && ((oif != NULL) || ( 2447 #ifdef INET6 2448 is_ipv6 ? 2449 verify_path6(&(args->f_id.src_ip6), 2450 NULL, args->f_id.fib) : 2451 #endif 2452 verify_path(src_ip, NULL, args->f_id.fib)))); 2453 break; 2454 2455 case O_ANTISPOOF: 2456 /* Outgoing packets automatically pass/match */ 2457 if (oif == NULL && hlen > 0 && 2458 ( (is_ipv4 && in_localaddr(src_ip)) 2459 #ifdef INET6 2460 || (is_ipv6 && 2461 in6_localaddr(&(args->f_id.src_ip6))) 2462 #endif 2463 )) 2464 match = 2465 #ifdef INET6 2466 is_ipv6 ? verify_path6( 2467 &(args->f_id.src_ip6), iif, 2468 args->f_id.fib) : 2469 #endif 2470 verify_path(src_ip, iif, 2471 args->f_id.fib); 2472 else 2473 match = 1; 2474 break; 2475 2476 case O_IPSEC: 2477 match = (m_tag_find(m, 2478 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 2479 /* otherwise no match */ 2480 break; 2481 2482 #ifdef INET6 2483 case O_IP6_SRC: 2484 match = is_ipv6 && 2485 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 2486 &((ipfw_insn_ip6 *)cmd)->addr6); 2487 break; 2488 2489 case O_IP6_DST: 2490 match = is_ipv6 && 2491 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 2492 &((ipfw_insn_ip6 *)cmd)->addr6); 2493 break; 2494 case O_IP6_SRC_MASK: 2495 case O_IP6_DST_MASK: 2496 if (is_ipv6) { 2497 int i = cmdlen - 1; 2498 struct in6_addr p; 2499 struct in6_addr *d = 2500 &((ipfw_insn_ip6 *)cmd)->addr6; 2501 2502 for (; !match && i > 0; d += 2, 2503 i -= F_INSN_SIZE(struct in6_addr) 2504 * 2) { 2505 p = (cmd->opcode == 2506 O_IP6_SRC_MASK) ? 2507 args->f_id.src_ip6: 2508 args->f_id.dst_ip6; 2509 APPLY_MASK(&p, &d[1]); 2510 match = 2511 IN6_ARE_ADDR_EQUAL(&d[0], 2512 &p); 2513 } 2514 } 2515 break; 2516 2517 case O_FLOW6ID: 2518 match = is_ipv6 && 2519 flow6id_match(args->f_id.flow_id6, 2520 (ipfw_insn_u32 *) cmd); 2521 break; 2522 2523 case O_EXT_HDR: 2524 match = is_ipv6 && 2525 (ext_hd & ((ipfw_insn *) cmd)->arg1); 2526 break; 2527 2528 case O_IP6: 2529 match = is_ipv6; 2530 break; 2531 #endif 2532 2533 case O_IP4: 2534 match = is_ipv4; 2535 break; 2536 2537 case O_TAG: { 2538 struct m_tag *mtag; 2539 uint32_t tag = TARG(cmd->arg1, tag); 2540 2541 /* Packet is already tagged with this tag? */ 2542 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 2543 2544 /* We have `untag' action when F_NOT flag is 2545 * present. And we must remove this mtag from 2546 * mbuf and reset `match' to zero (`match' will 2547 * be inversed later). 2548 * Otherwise we should allocate new mtag and 2549 * push it into mbuf. 2550 */ 2551 if (cmd->len & F_NOT) { /* `untag' action */ 2552 if (mtag != NULL) 2553 m_tag_delete(m, mtag); 2554 match = 0; 2555 } else { 2556 if (mtag == NULL) { 2557 mtag = m_tag_alloc( MTAG_IPFW, 2558 tag, 0, M_NOWAIT); 2559 if (mtag != NULL) 2560 m_tag_prepend(m, mtag); 2561 } 2562 match = 1; 2563 } 2564 break; 2565 } 2566 2567 case O_FIB: /* try match the specified fib */ 2568 if (args->f_id.fib == cmd->arg1) 2569 match = 1; 2570 break; 2571 2572 case O_SOCKARG: { 2573 #ifndef USERSPACE /* not supported in userspace */ 2574 struct inpcb *inp = args->inp; 2575 struct inpcbinfo *pi; 2576 2577 if (is_ipv6) /* XXX can we remove this ? */ 2578 break; 2579 2580 if (proto == IPPROTO_TCP) 2581 pi = &V_tcbinfo; 2582 else if (proto == IPPROTO_UDP) 2583 pi = &V_udbinfo; 2584 else if (proto == IPPROTO_UDPLITE) 2585 pi = &V_ulitecbinfo; 2586 else 2587 break; 2588 2589 /* 2590 * XXXRW: so_user_cookie should almost 2591 * certainly be inp_user_cookie? 2592 */ 2593 2594 /* For incoming packet, lookup up the 2595 inpcb using the src/dest ip/port tuple */ 2596 if (inp == NULL) { 2597 inp = in_pcblookup(pi, 2598 src_ip, htons(src_port), 2599 dst_ip, htons(dst_port), 2600 INPLOOKUP_RLOCKPCB, NULL); 2601 if (inp != NULL) { 2602 tablearg = 2603 inp->inp_socket->so_user_cookie; 2604 if (tablearg) 2605 match = 1; 2606 INP_RUNLOCK(inp); 2607 } 2608 } else { 2609 if (inp->inp_socket) { 2610 tablearg = 2611 inp->inp_socket->so_user_cookie; 2612 if (tablearg) 2613 match = 1; 2614 } 2615 } 2616 #endif /* !USERSPACE */ 2617 break; 2618 } 2619 2620 case O_TAGGED: { 2621 struct m_tag *mtag; 2622 uint32_t tag = TARG(cmd->arg1, tag); 2623 2624 if (cmdlen == 1) { 2625 match = m_tag_locate(m, MTAG_IPFW, 2626 tag, NULL) != NULL; 2627 break; 2628 } 2629 2630 /* we have ranges */ 2631 for (mtag = m_tag_first(m); 2632 mtag != NULL && !match; 2633 mtag = m_tag_next(m, mtag)) { 2634 uint16_t *p; 2635 int i; 2636 2637 if (mtag->m_tag_cookie != MTAG_IPFW) 2638 continue; 2639 2640 p = ((ipfw_insn_u16 *)cmd)->ports; 2641 i = cmdlen - 1; 2642 for(; !match && i > 0; i--, p += 2) 2643 match = 2644 mtag->m_tag_id >= p[0] && 2645 mtag->m_tag_id <= p[1]; 2646 } 2647 break; 2648 } 2649 2650 /* 2651 * The second set of opcodes represents 'actions', 2652 * i.e. the terminal part of a rule once the packet 2653 * matches all previous patterns. 2654 * Typically there is only one action for each rule, 2655 * and the opcode is stored at the end of the rule 2656 * (but there are exceptions -- see below). 2657 * 2658 * In general, here we set retval and terminate the 2659 * outer loop (would be a 'break 3' in some language, 2660 * but we need to set l=0, done=1) 2661 * 2662 * Exceptions: 2663 * O_COUNT and O_SKIPTO actions: 2664 * instead of terminating, we jump to the next rule 2665 * (setting l=0), or to the SKIPTO target (setting 2666 * f/f_len, cmd and l as needed), respectively. 2667 * 2668 * O_TAG, O_LOG and O_ALTQ action parameters: 2669 * perform some action and set match = 1; 2670 * 2671 * O_LIMIT and O_KEEP_STATE: these opcodes are 2672 * not real 'actions', and are stored right 2673 * before the 'action' part of the rule (one 2674 * exception is O_SKIP_ACTION which could be 2675 * between these opcodes and 'action' one). 2676 * These opcodes try to install an entry in the 2677 * state tables; if successful, we continue with 2678 * the next opcode (match=1; break;), otherwise 2679 * the packet must be dropped (set retval, 2680 * break loops with l=0, done=1) 2681 * 2682 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2683 * cause a lookup of the state table, and a jump 2684 * to the 'action' part of the parent rule 2685 * if an entry is found, or 2686 * (CHECK_STATE only) a jump to the next rule if 2687 * the entry is not found. 2688 * The result of the lookup is cached so that 2689 * further instances of these opcodes become NOPs. 2690 * The jump to the next rule is done by setting 2691 * l=0, cmdlen=0. 2692 * 2693 * O_SKIP_ACTION: this opcode is not a real 'action' 2694 * either, and is stored right before the 'action' 2695 * part of the rule, right after the O_KEEP_STATE 2696 * opcode. It causes match failure so the real 2697 * 'action' could be executed only if the rule 2698 * is checked via dynamic rule from the state 2699 * table, as in such case execution starts 2700 * from the true 'action' opcode directly. 2701 * 2702 */ 2703 case O_LIMIT: 2704 case O_KEEP_STATE: 2705 if (ipfw_dyn_install_state(chain, f, 2706 (ipfw_insn_limit *)cmd, args, ulp, 2707 pktlen, &dyn_info, tablearg)) { 2708 /* error or limit violation */ 2709 retval = IP_FW_DENY; 2710 l = 0; /* exit inner loop */ 2711 done = 1; /* exit outer loop */ 2712 } 2713 match = 1; 2714 break; 2715 2716 case O_PROBE_STATE: 2717 case O_CHECK_STATE: 2718 /* 2719 * dynamic rules are checked at the first 2720 * keep-state or check-state occurrence, 2721 * with the result being stored in dyn_info. 2722 * The compiler introduces a PROBE_STATE 2723 * instruction for us when we have a 2724 * KEEP_STATE (because PROBE_STATE needs 2725 * to be run first). 2726 */ 2727 if (DYN_LOOKUP_NEEDED(&dyn_info, cmd) && 2728 (q = ipfw_dyn_lookup_state(args, ulp, 2729 pktlen, cmd, &dyn_info)) != NULL) { 2730 /* 2731 * Found dynamic entry, jump to the 2732 * 'action' part of the parent rule 2733 * by setting f, cmd, l and clearing 2734 * cmdlen. 2735 */ 2736 f = q; 2737 f_pos = dyn_info.f_pos; 2738 cmd = ACTION_PTR(f); 2739 l = f->cmd_len - f->act_ofs; 2740 cmdlen = 0; 2741 match = 1; 2742 break; 2743 } 2744 /* 2745 * Dynamic entry not found. If CHECK_STATE, 2746 * skip to next rule, if PROBE_STATE just 2747 * ignore and continue with next opcode. 2748 */ 2749 if (cmd->opcode == O_CHECK_STATE) 2750 l = 0; /* exit inner loop */ 2751 match = 1; 2752 break; 2753 2754 case O_SKIP_ACTION: 2755 match = 0; /* skip to the next rule */ 2756 l = 0; /* exit inner loop */ 2757 break; 2758 2759 case O_ACCEPT: 2760 retval = 0; /* accept */ 2761 l = 0; /* exit inner loop */ 2762 done = 1; /* exit outer loop */ 2763 break; 2764 2765 case O_PIPE: 2766 case O_QUEUE: 2767 set_match(args, f_pos, chain); 2768 args->rule.info = TARG(cmd->arg1, pipe); 2769 if (cmd->opcode == O_PIPE) 2770 args->rule.info |= IPFW_IS_PIPE; 2771 if (V_fw_one_pass) 2772 args->rule.info |= IPFW_ONEPASS; 2773 retval = IP_FW_DUMMYNET; 2774 l = 0; /* exit inner loop */ 2775 done = 1; /* exit outer loop */ 2776 break; 2777 2778 case O_DIVERT: 2779 case O_TEE: 2780 if (args->flags & IPFW_ARGS_ETHER) 2781 break; /* not on layer 2 */ 2782 /* otherwise this is terminal */ 2783 l = 0; /* exit inner loop */ 2784 done = 1; /* exit outer loop */ 2785 retval = (cmd->opcode == O_DIVERT) ? 2786 IP_FW_DIVERT : IP_FW_TEE; 2787 set_match(args, f_pos, chain); 2788 args->rule.info = TARG(cmd->arg1, divert); 2789 break; 2790 2791 case O_COUNT: 2792 IPFW_INC_RULE_COUNTER(f, pktlen); 2793 l = 0; /* exit inner loop */ 2794 break; 2795 2796 case O_SKIPTO: 2797 IPFW_INC_RULE_COUNTER(f, pktlen); 2798 f_pos = JUMP(chain, f, cmd->arg1, tablearg, 0); 2799 /* 2800 * Skip disabled rules, and re-enter 2801 * the inner loop with the correct 2802 * f_pos, f, l and cmd. 2803 * Also clear cmdlen and skip_or 2804 */ 2805 for (; f_pos < chain->n_rules - 1 && 2806 (V_set_disable & 2807 (1 << chain->map[f_pos]->set)); 2808 f_pos++) 2809 ; 2810 /* Re-enter the inner loop at the skipto rule. */ 2811 f = chain->map[f_pos]; 2812 l = f->cmd_len; 2813 cmd = f->cmd; 2814 match = 1; 2815 cmdlen = 0; 2816 skip_or = 0; 2817 continue; 2818 break; /* not reached */ 2819 2820 case O_CALLRETURN: { 2821 /* 2822 * Implementation of `subroutine' call/return, 2823 * in the stack carried in an mbuf tag. This 2824 * is different from `skipto' in that any call 2825 * address is possible (`skipto' must prevent 2826 * backward jumps to avoid endless loops). 2827 * We have `return' action when F_NOT flag is 2828 * present. The `m_tag_id' field is used as 2829 * stack pointer. 2830 */ 2831 struct m_tag *mtag; 2832 uint16_t jmpto, *stack; 2833 2834 #define IS_CALL ((cmd->len & F_NOT) == 0) 2835 #define IS_RETURN ((cmd->len & F_NOT) != 0) 2836 /* 2837 * Hand-rolled version of m_tag_locate() with 2838 * wildcard `type'. 2839 * If not already tagged, allocate new tag. 2840 */ 2841 mtag = m_tag_first(m); 2842 while (mtag != NULL) { 2843 if (mtag->m_tag_cookie == 2844 MTAG_IPFW_CALL) 2845 break; 2846 mtag = m_tag_next(m, mtag); 2847 } 2848 if (mtag == NULL && IS_CALL) { 2849 mtag = m_tag_alloc(MTAG_IPFW_CALL, 0, 2850 IPFW_CALLSTACK_SIZE * 2851 sizeof(uint16_t), M_NOWAIT); 2852 if (mtag != NULL) 2853 m_tag_prepend(m, mtag); 2854 } 2855 2856 /* 2857 * On error both `call' and `return' just 2858 * continue with next rule. 2859 */ 2860 if (IS_RETURN && (mtag == NULL || 2861 mtag->m_tag_id == 0)) { 2862 l = 0; /* exit inner loop */ 2863 break; 2864 } 2865 if (IS_CALL && (mtag == NULL || 2866 mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) { 2867 printf("ipfw: call stack error, " 2868 "go to next rule\n"); 2869 l = 0; /* exit inner loop */ 2870 break; 2871 } 2872 2873 IPFW_INC_RULE_COUNTER(f, pktlen); 2874 stack = (uint16_t *)(mtag + 1); 2875 2876 /* 2877 * The `call' action may use cached f_pos 2878 * (in f->next_rule), whose version is written 2879 * in f->next_rule. 2880 * The `return' action, however, doesn't have 2881 * fixed jump address in cmd->arg1 and can't use 2882 * cache. 2883 */ 2884 if (IS_CALL) { 2885 stack[mtag->m_tag_id] = f->rulenum; 2886 mtag->m_tag_id++; 2887 f_pos = JUMP(chain, f, cmd->arg1, 2888 tablearg, 1); 2889 } else { /* `return' action */ 2890 mtag->m_tag_id--; 2891 jmpto = stack[mtag->m_tag_id] + 1; 2892 f_pos = ipfw_find_rule(chain, jmpto, 0); 2893 } 2894 2895 /* 2896 * Skip disabled rules, and re-enter 2897 * the inner loop with the correct 2898 * f_pos, f, l and cmd. 2899 * Also clear cmdlen and skip_or 2900 */ 2901 for (; f_pos < chain->n_rules - 1 && 2902 (V_set_disable & 2903 (1 << chain->map[f_pos]->set)); f_pos++) 2904 ; 2905 /* Re-enter the inner loop at the dest rule. */ 2906 f = chain->map[f_pos]; 2907 l = f->cmd_len; 2908 cmd = f->cmd; 2909 cmdlen = 0; 2910 skip_or = 0; 2911 continue; 2912 break; /* NOTREACHED */ 2913 } 2914 #undef IS_CALL 2915 #undef IS_RETURN 2916 2917 case O_REJECT: 2918 /* 2919 * Drop the packet and send a reject notice 2920 * if the packet is not ICMP (or is an ICMP 2921 * query), and it is not multicast/broadcast. 2922 */ 2923 if (hlen > 0 && is_ipv4 && offset == 0 && 2924 (proto != IPPROTO_ICMP || 2925 is_icmp_query(ICMP(ulp))) && 2926 !(m->m_flags & (M_BCAST|M_MCAST)) && 2927 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 2928 send_reject(args, cmd->arg1, iplen, ip); 2929 m = args->m; 2930 } 2931 /* FALLTHROUGH */ 2932 #ifdef INET6 2933 case O_UNREACH6: 2934 if (hlen > 0 && is_ipv6 && 2935 ((offset & IP6F_OFF_MASK) == 0) && 2936 (proto != IPPROTO_ICMPV6 || 2937 (is_icmp6_query(icmp6_type) == 1)) && 2938 !(m->m_flags & (M_BCAST|M_MCAST)) && 2939 !IN6_IS_ADDR_MULTICAST( 2940 &args->f_id.dst_ip6)) { 2941 send_reject6(args, 2942 cmd->opcode == O_REJECT ? 2943 map_icmp_unreach(cmd->arg1): 2944 cmd->arg1, hlen, 2945 (struct ip6_hdr *)ip); 2946 m = args->m; 2947 } 2948 /* FALLTHROUGH */ 2949 #endif 2950 case O_DENY: 2951 retval = IP_FW_DENY; 2952 l = 0; /* exit inner loop */ 2953 done = 1; /* exit outer loop */ 2954 break; 2955 2956 case O_FORWARD_IP: 2957 if (args->flags & IPFW_ARGS_ETHER) 2958 break; /* not valid on layer2 pkts */ 2959 if (q != f || 2960 dyn_info.direction == MATCH_FORWARD) { 2961 struct sockaddr_in *sa; 2962 2963 sa = &(((ipfw_insn_sa *)cmd)->sa); 2964 if (sa->sin_addr.s_addr == INADDR_ANY) { 2965 #ifdef INET6 2966 /* 2967 * We use O_FORWARD_IP opcode for 2968 * fwd rule with tablearg, but tables 2969 * now support IPv6 addresses. And 2970 * when we are inspecting IPv6 packet, 2971 * we can use nh6 field from 2972 * table_value as next_hop6 address. 2973 */ 2974 if (is_ipv6) { 2975 struct ip_fw_nh6 *nh6; 2976 2977 args->flags |= IPFW_ARGS_NH6; 2978 nh6 = &args->hopstore6; 2979 nh6->sin6_addr = TARG_VAL( 2980 chain, tablearg, nh6); 2981 nh6->sin6_port = sa->sin_port; 2982 nh6->sin6_scope_id = TARG_VAL( 2983 chain, tablearg, zoneid); 2984 } else 2985 #endif 2986 { 2987 args->flags |= IPFW_ARGS_NH4; 2988 args->hopstore.sin_port = 2989 sa->sin_port; 2990 sa = &args->hopstore; 2991 sa->sin_family = AF_INET; 2992 sa->sin_len = sizeof(*sa); 2993 sa->sin_addr.s_addr = htonl( 2994 TARG_VAL(chain, tablearg, 2995 nh4)); 2996 } 2997 } else { 2998 args->flags |= IPFW_ARGS_NH4PTR; 2999 args->next_hop = sa; 3000 } 3001 } 3002 retval = IP_FW_PASS; 3003 l = 0; /* exit inner loop */ 3004 done = 1; /* exit outer loop */ 3005 break; 3006 3007 #ifdef INET6 3008 case O_FORWARD_IP6: 3009 if (args->flags & IPFW_ARGS_ETHER) 3010 break; /* not valid on layer2 pkts */ 3011 if (q != f || 3012 dyn_info.direction == MATCH_FORWARD) { 3013 struct sockaddr_in6 *sin6; 3014 3015 sin6 = &(((ipfw_insn_sa6 *)cmd)->sa); 3016 args->flags |= IPFW_ARGS_NH6PTR; 3017 args->next_hop6 = sin6; 3018 } 3019 retval = IP_FW_PASS; 3020 l = 0; /* exit inner loop */ 3021 done = 1; /* exit outer loop */ 3022 break; 3023 #endif 3024 3025 case O_NETGRAPH: 3026 case O_NGTEE: 3027 set_match(args, f_pos, chain); 3028 args->rule.info = TARG(cmd->arg1, netgraph); 3029 if (V_fw_one_pass) 3030 args->rule.info |= IPFW_ONEPASS; 3031 retval = (cmd->opcode == O_NETGRAPH) ? 3032 IP_FW_NETGRAPH : IP_FW_NGTEE; 3033 l = 0; /* exit inner loop */ 3034 done = 1; /* exit outer loop */ 3035 break; 3036 3037 case O_SETFIB: { 3038 uint32_t fib; 3039 3040 IPFW_INC_RULE_COUNTER(f, pktlen); 3041 fib = TARG(cmd->arg1, fib) & 0x7FFF; 3042 if (fib >= rt_numfibs) 3043 fib = 0; 3044 M_SETFIB(m, fib); 3045 args->f_id.fib = fib; /* XXX */ 3046 l = 0; /* exit inner loop */ 3047 break; 3048 } 3049 3050 case O_SETDSCP: { 3051 uint16_t code; 3052 3053 code = TARG(cmd->arg1, dscp) & 0x3F; 3054 l = 0; /* exit inner loop */ 3055 if (is_ipv4) { 3056 uint16_t old; 3057 3058 old = *(uint16_t *)ip; 3059 ip->ip_tos = (code << 2) | 3060 (ip->ip_tos & 0x03); 3061 ip->ip_sum = cksum_adjust(ip->ip_sum, 3062 old, *(uint16_t *)ip); 3063 } else if (is_ipv6) { 3064 uint8_t *v; 3065 3066 v = &((struct ip6_hdr *)ip)->ip6_vfc; 3067 *v = (*v & 0xF0) | (code >> 2); 3068 v++; 3069 *v = (*v & 0x3F) | ((code & 0x03) << 6); 3070 } else 3071 break; 3072 3073 IPFW_INC_RULE_COUNTER(f, pktlen); 3074 break; 3075 } 3076 3077 case O_NAT: 3078 l = 0; /* exit inner loop */ 3079 done = 1; /* exit outer loop */ 3080 /* 3081 * Ensure that we do not invoke NAT handler for 3082 * non IPv4 packets. Libalias expects only IPv4. 3083 */ 3084 if (!is_ipv4 || !IPFW_NAT_LOADED) { 3085 retval = IP_FW_DENY; 3086 break; 3087 } 3088 3089 struct cfg_nat *t; 3090 int nat_id; 3091 3092 args->rule.info = 0; 3093 set_match(args, f_pos, chain); 3094 /* Check if this is 'global' nat rule */ 3095 if (cmd->arg1 == IP_FW_NAT44_GLOBAL) { 3096 retval = ipfw_nat_ptr(args, NULL, m); 3097 break; 3098 } 3099 t = ((ipfw_insn_nat *)cmd)->nat; 3100 if (t == NULL) { 3101 nat_id = TARG(cmd->arg1, nat); 3102 t = (*lookup_nat_ptr)(&chain->nat, nat_id); 3103 3104 if (t == NULL) { 3105 retval = IP_FW_DENY; 3106 break; 3107 } 3108 if (cmd->arg1 != IP_FW_TARG) 3109 ((ipfw_insn_nat *)cmd)->nat = t; 3110 } 3111 retval = ipfw_nat_ptr(args, t, m); 3112 break; 3113 3114 case O_REASS: { 3115 int ip_off; 3116 3117 l = 0; /* in any case exit inner loop */ 3118 if (is_ipv6) /* IPv6 is not supported yet */ 3119 break; 3120 IPFW_INC_RULE_COUNTER(f, pktlen); 3121 ip_off = ntohs(ip->ip_off); 3122 3123 /* if not fragmented, go to next rule */ 3124 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0) 3125 break; 3126 3127 args->m = m = ip_reass(m); 3128 3129 /* 3130 * do IP header checksum fixup. 3131 */ 3132 if (m == NULL) { /* fragment got swallowed */ 3133 retval = IP_FW_DENY; 3134 } else { /* good, packet complete */ 3135 int hlen; 3136 3137 ip = mtod(m, struct ip *); 3138 hlen = ip->ip_hl << 2; 3139 ip->ip_sum = 0; 3140 if (hlen == sizeof(struct ip)) 3141 ip->ip_sum = in_cksum_hdr(ip); 3142 else 3143 ip->ip_sum = in_cksum(m, hlen); 3144 retval = IP_FW_REASS; 3145 args->rule.info = 0; 3146 set_match(args, f_pos, chain); 3147 } 3148 done = 1; /* exit outer loop */ 3149 break; 3150 } 3151 case O_EXTERNAL_ACTION: 3152 l = 0; /* in any case exit inner loop */ 3153 retval = ipfw_run_eaction(chain, args, 3154 cmd, &done); 3155 /* 3156 * If both @retval and @done are zero, 3157 * consider this as rule matching and 3158 * update counters. 3159 */ 3160 if (retval == 0 && done == 0) { 3161 IPFW_INC_RULE_COUNTER(f, pktlen); 3162 /* 3163 * Reset the result of the last 3164 * dynamic state lookup. 3165 * External action can change 3166 * @args content, and it may be 3167 * used for new state lookup later. 3168 */ 3169 DYN_INFO_INIT(&dyn_info); 3170 } 3171 break; 3172 3173 default: 3174 panic("-- unknown opcode %d\n", cmd->opcode); 3175 } /* end of switch() on opcodes */ 3176 /* 3177 * if we get here with l=0, then match is irrelevant. 3178 */ 3179 3180 if (cmd->len & F_NOT) 3181 match = !match; 3182 3183 if (match) { 3184 if (cmd->len & F_OR) 3185 skip_or = 1; 3186 } else { 3187 if (!(cmd->len & F_OR)) /* not an OR block, */ 3188 break; /* try next rule */ 3189 } 3190 3191 } /* end of inner loop, scan opcodes */ 3192 #undef PULLUP_LEN 3193 #undef PULLUP_LEN_LOCKED 3194 3195 if (done) 3196 break; 3197 3198 /* next_rule:; */ /* try next rule */ 3199 3200 } /* end of outer for, scan rules */ 3201 3202 if (done) { 3203 struct ip_fw *rule = chain->map[f_pos]; 3204 /* Update statistics */ 3205 IPFW_INC_RULE_COUNTER(rule, pktlen); 3206 } else { 3207 retval = IP_FW_DENY; 3208 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 3209 } 3210 IPFW_PF_RUNLOCK(chain); 3211 #ifdef __FreeBSD__ 3212 if (ucred_cache != NULL) 3213 crfree(ucred_cache); 3214 #endif 3215 return (retval); 3216 3217 pullup_failed: 3218 if (V_fw_verbose) 3219 printf("ipfw: pullup failed\n"); 3220 return (IP_FW_DENY); 3221 } 3222 3223 /* 3224 * Set maximum number of tables that can be used in given VNET ipfw instance. 3225 */ 3226 #ifdef SYSCTL_NODE 3227 static int 3228 sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS) 3229 { 3230 int error; 3231 unsigned int ntables; 3232 3233 ntables = V_fw_tables_max; 3234 3235 error = sysctl_handle_int(oidp, &ntables, 0, req); 3236 /* Read operation or some error */ 3237 if ((error != 0) || (req->newptr == NULL)) 3238 return (error); 3239 3240 return (ipfw_resize_tables(&V_layer3_chain, ntables)); 3241 } 3242 3243 /* 3244 * Switches table namespace between global and per-set. 3245 */ 3246 static int 3247 sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS) 3248 { 3249 int error; 3250 unsigned int sets; 3251 3252 sets = V_fw_tables_sets; 3253 3254 error = sysctl_handle_int(oidp, &sets, 0, req); 3255 /* Read operation or some error */ 3256 if ((error != 0) || (req->newptr == NULL)) 3257 return (error); 3258 3259 return (ipfw_switch_tables_namespace(&V_layer3_chain, sets)); 3260 } 3261 #endif 3262 3263 /* 3264 * Module and VNET glue 3265 */ 3266 3267 /* 3268 * Stuff that must be initialised only on boot or module load 3269 */ 3270 static int 3271 ipfw_init(void) 3272 { 3273 int error = 0; 3274 3275 /* 3276 * Only print out this stuff the first time around, 3277 * when called from the sysinit code. 3278 */ 3279 printf("ipfw2 " 3280 #ifdef INET6 3281 "(+ipv6) " 3282 #endif 3283 "initialized, divert %s, nat %s, " 3284 "default to %s, logging ", 3285 #ifdef IPDIVERT 3286 "enabled", 3287 #else 3288 "loadable", 3289 #endif 3290 #ifdef IPFIREWALL_NAT 3291 "enabled", 3292 #else 3293 "loadable", 3294 #endif 3295 default_to_accept ? "accept" : "deny"); 3296 3297 /* 3298 * Note: V_xxx variables can be accessed here but the vnet specific 3299 * initializer may not have been called yet for the VIMAGE case. 3300 * Tuneables will have been processed. We will print out values for 3301 * the default vnet. 3302 * XXX This should all be rationalized AFTER 8.0 3303 */ 3304 if (V_fw_verbose == 0) 3305 printf("disabled\n"); 3306 else if (V_verbose_limit == 0) 3307 printf("unlimited\n"); 3308 else 3309 printf("limited to %d packets/entry by default\n", 3310 V_verbose_limit); 3311 3312 /* Check user-supplied table count for validness */ 3313 if (default_fw_tables > IPFW_TABLES_MAX) 3314 default_fw_tables = IPFW_TABLES_MAX; 3315 3316 ipfw_init_sopt_handler(); 3317 ipfw_init_obj_rewriter(); 3318 ipfw_iface_init(); 3319 return (error); 3320 } 3321 3322 /* 3323 * Called for the removal of the last instance only on module unload. 3324 */ 3325 static void 3326 ipfw_destroy(void) 3327 { 3328 3329 ipfw_iface_destroy(); 3330 ipfw_destroy_sopt_handler(); 3331 ipfw_destroy_obj_rewriter(); 3332 printf("IP firewall unloaded\n"); 3333 } 3334 3335 /* 3336 * Stuff that must be initialized for every instance 3337 * (including the first of course). 3338 */ 3339 static int 3340 vnet_ipfw_init(const void *unused) 3341 { 3342 int error, first; 3343 struct ip_fw *rule = NULL; 3344 struct ip_fw_chain *chain; 3345 3346 chain = &V_layer3_chain; 3347 3348 first = IS_DEFAULT_VNET(curvnet) ? 1 : 0; 3349 3350 /* First set up some values that are compile time options */ 3351 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 3352 V_fw_deny_unknown_exthdrs = 1; 3353 #ifdef IPFIREWALL_VERBOSE 3354 V_fw_verbose = 1; 3355 #endif 3356 #ifdef IPFIREWALL_VERBOSE_LIMIT 3357 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 3358 #endif 3359 #ifdef IPFIREWALL_NAT 3360 LIST_INIT(&chain->nat); 3361 #endif 3362 3363 /* Init shared services hash table */ 3364 ipfw_init_srv(chain); 3365 3366 ipfw_init_counters(); 3367 /* Set initial number of tables */ 3368 V_fw_tables_max = default_fw_tables; 3369 error = ipfw_init_tables(chain, first); 3370 if (error) { 3371 printf("ipfw2: setting up tables failed\n"); 3372 free(chain->map, M_IPFW); 3373 free(rule, M_IPFW); 3374 return (ENOSPC); 3375 } 3376 3377 IPFW_LOCK_INIT(chain); 3378 3379 /* fill and insert the default rule */ 3380 rule = ipfw_alloc_rule(chain, sizeof(struct ip_fw)); 3381 rule->flags |= IPFW_RULE_NOOPT; 3382 rule->cmd_len = 1; 3383 rule->cmd[0].len = 1; 3384 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY; 3385 chain->default_rule = rule; 3386 ipfw_add_protected_rule(chain, rule, 0); 3387 3388 ipfw_dyn_init(chain); 3389 ipfw_eaction_init(chain, first); 3390 #ifdef LINEAR_SKIPTO 3391 ipfw_init_skipto_cache(chain); 3392 #endif 3393 ipfw_bpf_init(first); 3394 3395 /* First set up some values that are compile time options */ 3396 V_ipfw_vnet_ready = 1; /* Open for business */ 3397 3398 /* 3399 * Hook the sockopt handler and pfil hooks for ipv4 and ipv6. 3400 * Even if the latter two fail we still keep the module alive 3401 * because the sockopt and layer2 paths are still useful. 3402 * ipfw[6]_hook return 0 on success, ENOENT on failure, 3403 * so we can ignore the exact return value and just set a flag. 3404 * 3405 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so 3406 * changes in the underlying (per-vnet) variables trigger 3407 * immediate hook()/unhook() calls. 3408 * In layer2 we have the same behaviour, except that V_ether_ipfw 3409 * is checked on each packet because there are no pfil hooks. 3410 */ 3411 V_ip_fw_ctl_ptr = ipfw_ctl3; 3412 error = ipfw_attach_hooks(); 3413 return (error); 3414 } 3415 3416 /* 3417 * Called for the removal of each instance. 3418 */ 3419 static int 3420 vnet_ipfw_uninit(const void *unused) 3421 { 3422 struct ip_fw *reap; 3423 struct ip_fw_chain *chain = &V_layer3_chain; 3424 int i, last; 3425 3426 V_ipfw_vnet_ready = 0; /* tell new callers to go away */ 3427 /* 3428 * disconnect from ipv4, ipv6, layer2 and sockopt. 3429 * Then grab, release and grab again the WLOCK so we make 3430 * sure the update is propagated and nobody will be in. 3431 */ 3432 ipfw_detach_hooks(); 3433 V_ip_fw_ctl_ptr = NULL; 3434 3435 last = IS_DEFAULT_VNET(curvnet) ? 1 : 0; 3436 3437 IPFW_UH_WLOCK(chain); 3438 IPFW_UH_WUNLOCK(chain); 3439 3440 ipfw_dyn_uninit(0); /* run the callout_drain */ 3441 3442 IPFW_UH_WLOCK(chain); 3443 3444 reap = NULL; 3445 IPFW_WLOCK(chain); 3446 for (i = 0; i < chain->n_rules; i++) 3447 ipfw_reap_add(chain, &reap, chain->map[i]); 3448 free(chain->map, M_IPFW); 3449 #ifdef LINEAR_SKIPTO 3450 ipfw_destroy_skipto_cache(chain); 3451 #endif 3452 IPFW_WUNLOCK(chain); 3453 IPFW_UH_WUNLOCK(chain); 3454 ipfw_destroy_tables(chain, last); 3455 ipfw_eaction_uninit(chain, last); 3456 if (reap != NULL) 3457 ipfw_reap_rules(reap); 3458 vnet_ipfw_iface_destroy(chain); 3459 ipfw_destroy_srv(chain); 3460 IPFW_LOCK_DESTROY(chain); 3461 ipfw_dyn_uninit(1); /* free the remaining parts */ 3462 ipfw_destroy_counters(); 3463 ipfw_bpf_uninit(last); 3464 return (0); 3465 } 3466 3467 /* 3468 * Module event handler. 3469 * In general we have the choice of handling most of these events by the 3470 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to 3471 * use the SYSINIT handlers as they are more capable of expressing the 3472 * flow of control during module and vnet operations, so this is just 3473 * a skeleton. Note there is no SYSINIT equivalent of the module 3474 * SHUTDOWN handler, but we don't have anything to do in that case anyhow. 3475 */ 3476 static int 3477 ipfw_modevent(module_t mod, int type, void *unused) 3478 { 3479 int err = 0; 3480 3481 switch (type) { 3482 case MOD_LOAD: 3483 /* Called once at module load or 3484 * system boot if compiled in. */ 3485 break; 3486 case MOD_QUIESCE: 3487 /* Called before unload. May veto unloading. */ 3488 break; 3489 case MOD_UNLOAD: 3490 /* Called during unload. */ 3491 break; 3492 case MOD_SHUTDOWN: 3493 /* Called during system shutdown. */ 3494 break; 3495 default: 3496 err = EOPNOTSUPP; 3497 break; 3498 } 3499 return err; 3500 } 3501 3502 static moduledata_t ipfwmod = { 3503 "ipfw", 3504 ipfw_modevent, 3505 0 3506 }; 3507 3508 /* Define startup order. */ 3509 #define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_FIREWALL 3510 #define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */ 3511 #define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */ 3512 #define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */ 3513 3514 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER); 3515 FEATURE(ipfw_ctl3, "ipfw new sockopt calls"); 3516 MODULE_VERSION(ipfw, 3); 3517 /* should declare some dependencies here */ 3518 3519 /* 3520 * Starting up. Done in order after ipfwmod() has been called. 3521 * VNET_SYSINIT is also called for each existing vnet and each new vnet. 3522 */ 3523 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 3524 ipfw_init, NULL); 3525 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 3526 vnet_ipfw_init, NULL); 3527 3528 /* 3529 * Closing up shop. These are done in REVERSE ORDER, but still 3530 * after ipfwmod() has been called. Not called on reboot. 3531 * VNET_SYSUNINIT is also called for each exiting vnet as it exits. 3532 * or when the module is unloaded. 3533 */ 3534 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 3535 ipfw_destroy, NULL); 3536 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 3537 vnet_ipfw_uninit, NULL); 3538 /* end of file */ 3539