1 /*- 2 * Copyright (c) 2002-2009 Luigi Rizzo, Universita` di Pisa 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 26 #include <sys/cdefs.h> 27 __FBSDID("$FreeBSD$"); 28 29 /* 30 * The FreeBSD IP packet firewall, main file 31 */ 32 33 #include "opt_ipfw.h" 34 #include "opt_ipdivert.h" 35 #include "opt_inet.h" 36 #ifndef INET 37 #error "IPFIREWALL requires INET" 38 #endif /* INET */ 39 #include "opt_inet6.h" 40 #include "opt_ipsec.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/condvar.h> 45 #include <sys/eventhandler.h> 46 #include <sys/malloc.h> 47 #include <sys/mbuf.h> 48 #include <sys/kernel.h> 49 #include <sys/lock.h> 50 #include <sys/jail.h> 51 #include <sys/module.h> 52 #include <sys/priv.h> 53 #include <sys/proc.h> 54 #include <sys/rwlock.h> 55 #include <sys/socket.h> 56 #include <sys/socketvar.h> 57 #include <sys/sysctl.h> 58 #include <sys/syslog.h> 59 #include <sys/ucred.h> 60 #include <net/ethernet.h> /* for ETHERTYPE_IP */ 61 #include <net/if.h> 62 #include <net/route.h> 63 #include <net/pf_mtag.h> 64 #include <net/pfil.h> 65 #include <net/vnet.h> 66 67 #include <netinet/in.h> 68 #include <netinet/in_var.h> 69 #include <netinet/in_pcb.h> 70 #include <netinet/ip.h> 71 #include <netinet/ip_var.h> 72 #include <netinet/ip_icmp.h> 73 #include <netinet/ip_fw.h> 74 #include <netinet/ip_carp.h> 75 #include <netinet/pim.h> 76 #include <netinet/tcp_var.h> 77 #include <netinet/udp.h> 78 #include <netinet/udp_var.h> 79 #include <netinet/sctp.h> 80 81 #include <netinet/ip6.h> 82 #include <netinet/icmp6.h> 83 #ifdef INET6 84 #include <netinet6/in6_pcb.h> 85 #include <netinet6/scope6_var.h> 86 #include <netinet6/ip6_var.h> 87 #endif 88 89 #include <netpfil/ipfw/ip_fw_private.h> 90 91 #include <machine/in_cksum.h> /* XXX for in_cksum */ 92 93 #ifdef MAC 94 #include <security/mac/mac_framework.h> 95 #endif 96 97 /* 98 * static variables followed by global ones. 99 * All ipfw global variables are here. 100 */ 101 102 /* ipfw_vnet_ready controls when we are open for business */ 103 static VNET_DEFINE(int, ipfw_vnet_ready) = 0; 104 #define V_ipfw_vnet_ready VNET(ipfw_vnet_ready) 105 106 static VNET_DEFINE(int, fw_deny_unknown_exthdrs); 107 #define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs) 108 109 static VNET_DEFINE(int, fw_permit_single_frag6) = 1; 110 #define V_fw_permit_single_frag6 VNET(fw_permit_single_frag6) 111 112 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 113 static int default_to_accept = 1; 114 #else 115 static int default_to_accept; 116 #endif 117 118 VNET_DEFINE(int, autoinc_step); 119 VNET_DEFINE(int, fw_one_pass) = 1; 120 121 VNET_DEFINE(unsigned int, fw_tables_max); 122 /* Use 128 tables by default */ 123 static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT; 124 125 /* 126 * Each rule belongs to one of 32 different sets (0..31). 127 * The variable set_disable contains one bit per set. 128 * If the bit is set, all rules in the corresponding set 129 * are disabled. Set RESVD_SET(31) is reserved for the default rule 130 * and rules that are not deleted by the flush command, 131 * and CANNOT be disabled. 132 * Rules in set RESVD_SET can only be deleted individually. 133 */ 134 VNET_DEFINE(u_int32_t, set_disable); 135 #define V_set_disable VNET(set_disable) 136 137 VNET_DEFINE(int, fw_verbose); 138 /* counter for ipfw_log(NULL...) */ 139 VNET_DEFINE(u_int64_t, norule_counter); 140 VNET_DEFINE(int, verbose_limit); 141 142 /* layer3_chain contains the list of rules for layer 3 */ 143 VNET_DEFINE(struct ip_fw_chain, layer3_chain); 144 145 VNET_DEFINE(int, ipfw_nat_ready) = 0; 146 147 ipfw_nat_t *ipfw_nat_ptr = NULL; 148 struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int); 149 ipfw_nat_cfg_t *ipfw_nat_cfg_ptr; 150 ipfw_nat_cfg_t *ipfw_nat_del_ptr; 151 ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr; 152 ipfw_nat_cfg_t *ipfw_nat_get_log_ptr; 153 154 #ifdef SYSCTL_NODE 155 uint32_t dummy_def = IPFW_DEFAULT_RULE; 156 static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS); 157 158 SYSBEGIN(f3) 159 160 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 161 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 162 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0, 163 "Only do a single pass through ipfw when using dummynet(4)"); 164 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, 165 CTLFLAG_RW, &VNET_NAME(autoinc_step), 0, 166 "Rule number auto-increment step"); 167 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose, 168 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0, 169 "Log matches to ipfw rules"); 170 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, 171 CTLFLAG_RW, &VNET_NAME(verbose_limit), 0, 172 "Set upper limit of matches of ipfw rules logged"); 173 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD, 174 &dummy_def, 0, 175 "The default/max possible rule number."); 176 SYSCTL_VNET_PROC(_net_inet_ip_fw, OID_AUTO, tables_max, 177 CTLTYPE_UINT|CTLFLAG_RW, 0, 0, sysctl_ipfw_table_num, "IU", 178 "Maximum number of tables"); 179 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN, 180 &default_to_accept, 0, 181 "Make the default rule accept all packets."); 182 TUNABLE_INT("net.inet.ip.fw.default_to_accept", &default_to_accept); 183 TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables); 184 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, static_count, 185 CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0, 186 "Number of static rules"); 187 188 #ifdef INET6 189 SYSCTL_DECL(_net_inet6_ip6); 190 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 191 SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs, 192 CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_deny_unknown_exthdrs), 0, 193 "Deny packets with unknown IPv6 Extension Headers"); 194 SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6, 195 CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_permit_single_frag6), 0, 196 "Permit single packet IPv6 fragments"); 197 #endif /* INET6 */ 198 199 SYSEND 200 201 #endif /* SYSCTL_NODE */ 202 203 204 /* 205 * Some macros used in the various matching options. 206 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 207 * Other macros just cast void * into the appropriate type 208 */ 209 #define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 210 #define TCP(p) ((struct tcphdr *)(p)) 211 #define SCTP(p) ((struct sctphdr *)(p)) 212 #define UDP(p) ((struct udphdr *)(p)) 213 #define ICMP(p) ((struct icmphdr *)(p)) 214 #define ICMP6(p) ((struct icmp6_hdr *)(p)) 215 216 static __inline int 217 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 218 { 219 int type = icmp->icmp_type; 220 221 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 222 } 223 224 #define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 225 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 226 227 static int 228 is_icmp_query(struct icmphdr *icmp) 229 { 230 int type = icmp->icmp_type; 231 232 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 233 } 234 #undef TT 235 236 /* 237 * The following checks use two arrays of 8 or 16 bits to store the 238 * bits that we want set or clear, respectively. They are in the 239 * low and high half of cmd->arg1 or cmd->d[0]. 240 * 241 * We scan options and store the bits we find set. We succeed if 242 * 243 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 244 * 245 * The code is sometimes optimized not to store additional variables. 246 */ 247 248 static int 249 flags_match(ipfw_insn *cmd, u_int8_t bits) 250 { 251 u_char want_clear; 252 bits = ~bits; 253 254 if ( ((cmd->arg1 & 0xff) & bits) != 0) 255 return 0; /* some bits we want set were clear */ 256 want_clear = (cmd->arg1 >> 8) & 0xff; 257 if ( (want_clear & bits) != want_clear) 258 return 0; /* some bits we want clear were set */ 259 return 1; 260 } 261 262 static int 263 ipopts_match(struct ip *ip, ipfw_insn *cmd) 264 { 265 int optlen, bits = 0; 266 u_char *cp = (u_char *)(ip + 1); 267 int x = (ip->ip_hl << 2) - sizeof (struct ip); 268 269 for (; x > 0; x -= optlen, cp += optlen) { 270 int opt = cp[IPOPT_OPTVAL]; 271 272 if (opt == IPOPT_EOL) 273 break; 274 if (opt == IPOPT_NOP) 275 optlen = 1; 276 else { 277 optlen = cp[IPOPT_OLEN]; 278 if (optlen <= 0 || optlen > x) 279 return 0; /* invalid or truncated */ 280 } 281 switch (opt) { 282 283 default: 284 break; 285 286 case IPOPT_LSRR: 287 bits |= IP_FW_IPOPT_LSRR; 288 break; 289 290 case IPOPT_SSRR: 291 bits |= IP_FW_IPOPT_SSRR; 292 break; 293 294 case IPOPT_RR: 295 bits |= IP_FW_IPOPT_RR; 296 break; 297 298 case IPOPT_TS: 299 bits |= IP_FW_IPOPT_TS; 300 break; 301 } 302 } 303 return (flags_match(cmd, bits)); 304 } 305 306 static int 307 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 308 { 309 int optlen, bits = 0; 310 u_char *cp = (u_char *)(tcp + 1); 311 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 312 313 for (; x > 0; x -= optlen, cp += optlen) { 314 int opt = cp[0]; 315 if (opt == TCPOPT_EOL) 316 break; 317 if (opt == TCPOPT_NOP) 318 optlen = 1; 319 else { 320 optlen = cp[1]; 321 if (optlen <= 0) 322 break; 323 } 324 325 switch (opt) { 326 327 default: 328 break; 329 330 case TCPOPT_MAXSEG: 331 bits |= IP_FW_TCPOPT_MSS; 332 break; 333 334 case TCPOPT_WINDOW: 335 bits |= IP_FW_TCPOPT_WINDOW; 336 break; 337 338 case TCPOPT_SACK_PERMITTED: 339 case TCPOPT_SACK: 340 bits |= IP_FW_TCPOPT_SACK; 341 break; 342 343 case TCPOPT_TIMESTAMP: 344 bits |= IP_FW_TCPOPT_TS; 345 break; 346 347 } 348 } 349 return (flags_match(cmd, bits)); 350 } 351 352 static int 353 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain, uint32_t *tablearg) 354 { 355 if (ifp == NULL) /* no iface with this packet, match fails */ 356 return 0; 357 /* Check by name or by IP address */ 358 if (cmd->name[0] != '\0') { /* match by name */ 359 if (cmd->name[0] == '\1') /* use tablearg to match */ 360 return ipfw_lookup_table_extended(chain, cmd->p.glob, 361 ifp->if_xname, tablearg, IPFW_TABLE_INTERFACE); 362 /* Check name */ 363 if (cmd->p.glob) { 364 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 365 return(1); 366 } else { 367 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 368 return(1); 369 } 370 } else { 371 #ifdef __FreeBSD__ /* and OSX too ? */ 372 struct ifaddr *ia; 373 374 if_addr_rlock(ifp); 375 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 376 if (ia->ifa_addr->sa_family != AF_INET) 377 continue; 378 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 379 (ia->ifa_addr))->sin_addr.s_addr) { 380 if_addr_runlock(ifp); 381 return(1); /* match */ 382 } 383 } 384 if_addr_runlock(ifp); 385 #endif /* __FreeBSD__ */ 386 } 387 return(0); /* no match, fail ... */ 388 } 389 390 /* 391 * The verify_path function checks if a route to the src exists and 392 * if it is reachable via ifp (when provided). 393 * 394 * The 'verrevpath' option checks that the interface that an IP packet 395 * arrives on is the same interface that traffic destined for the 396 * packet's source address would be routed out of. 397 * The 'versrcreach' option just checks that the source address is 398 * reachable via any route (except default) in the routing table. 399 * These two are a measure to block forged packets. This is also 400 * commonly known as "anti-spoofing" or Unicast Reverse Path 401 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 402 * is purposely reminiscent of the Cisco IOS command, 403 * 404 * ip verify unicast reverse-path 405 * ip verify unicast source reachable-via any 406 * 407 * which implements the same functionality. But note that the syntax 408 * is misleading, and the check may be performed on all IP packets 409 * whether unicast, multicast, or broadcast. 410 */ 411 static int 412 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib) 413 { 414 #ifndef __FreeBSD__ 415 return 0; 416 #else 417 struct route ro; 418 struct sockaddr_in *dst; 419 420 bzero(&ro, sizeof(ro)); 421 422 dst = (struct sockaddr_in *)&(ro.ro_dst); 423 dst->sin_family = AF_INET; 424 dst->sin_len = sizeof(*dst); 425 dst->sin_addr = src; 426 in_rtalloc_ign(&ro, 0, fib); 427 428 if (ro.ro_rt == NULL) 429 return 0; 430 431 /* 432 * If ifp is provided, check for equality with rtentry. 433 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 434 * in order to pass packets injected back by if_simloop(): 435 * if useloopback == 1 routing entry (via lo0) for our own address 436 * may exist, so we need to handle routing assymetry. 437 */ 438 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 439 RTFREE(ro.ro_rt); 440 return 0; 441 } 442 443 /* if no ifp provided, check if rtentry is not default route */ 444 if (ifp == NULL && 445 satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) { 446 RTFREE(ro.ro_rt); 447 return 0; 448 } 449 450 /* or if this is a blackhole/reject route */ 451 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 452 RTFREE(ro.ro_rt); 453 return 0; 454 } 455 456 /* found valid route */ 457 RTFREE(ro.ro_rt); 458 return 1; 459 #endif /* __FreeBSD__ */ 460 } 461 462 #ifdef INET6 463 /* 464 * ipv6 specific rules here... 465 */ 466 static __inline int 467 icmp6type_match (int type, ipfw_insn_u32 *cmd) 468 { 469 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 470 } 471 472 static int 473 flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 474 { 475 int i; 476 for (i=0; i <= cmd->o.arg1; ++i ) 477 if (curr_flow == cmd->d[i] ) 478 return 1; 479 return 0; 480 } 481 482 /* support for IP6_*_ME opcodes */ 483 static int 484 search_ip6_addr_net (struct in6_addr * ip6_addr) 485 { 486 struct ifnet *mdc; 487 struct ifaddr *mdc2; 488 struct in6_ifaddr *fdm; 489 struct in6_addr copia; 490 491 TAILQ_FOREACH(mdc, &V_ifnet, if_link) { 492 if_addr_rlock(mdc); 493 TAILQ_FOREACH(mdc2, &mdc->if_addrhead, ifa_link) { 494 if (mdc2->ifa_addr->sa_family == AF_INET6) { 495 fdm = (struct in6_ifaddr *)mdc2; 496 copia = fdm->ia_addr.sin6_addr; 497 /* need for leaving scope_id in the sock_addr */ 498 in6_clearscope(&copia); 499 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) { 500 if_addr_runlock(mdc); 501 return 1; 502 } 503 } 504 } 505 if_addr_runlock(mdc); 506 } 507 return 0; 508 } 509 510 static int 511 verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib) 512 { 513 struct route_in6 ro; 514 struct sockaddr_in6 *dst; 515 516 bzero(&ro, sizeof(ro)); 517 518 dst = (struct sockaddr_in6 * )&(ro.ro_dst); 519 dst->sin6_family = AF_INET6; 520 dst->sin6_len = sizeof(*dst); 521 dst->sin6_addr = *src; 522 523 in6_rtalloc_ign(&ro, 0, fib); 524 if (ro.ro_rt == NULL) 525 return 0; 526 527 /* 528 * if ifp is provided, check for equality with rtentry 529 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 530 * to support the case of sending packets to an address of our own. 531 * (where the former interface is the first argument of if_simloop() 532 * (=ifp), the latter is lo0) 533 */ 534 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 535 RTFREE(ro.ro_rt); 536 return 0; 537 } 538 539 /* if no ifp provided, check if rtentry is not default route */ 540 if (ifp == NULL && 541 IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) { 542 RTFREE(ro.ro_rt); 543 return 0; 544 } 545 546 /* or if this is a blackhole/reject route */ 547 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 548 RTFREE(ro.ro_rt); 549 return 0; 550 } 551 552 /* found valid route */ 553 RTFREE(ro.ro_rt); 554 return 1; 555 556 } 557 558 static int 559 is_icmp6_query(int icmp6_type) 560 { 561 if ((icmp6_type <= ICMP6_MAXTYPE) && 562 (icmp6_type == ICMP6_ECHO_REQUEST || 563 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 564 icmp6_type == ICMP6_WRUREQUEST || 565 icmp6_type == ICMP6_FQDN_QUERY || 566 icmp6_type == ICMP6_NI_QUERY)) 567 return (1); 568 569 return (0); 570 } 571 572 static void 573 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 574 { 575 struct mbuf *m; 576 577 m = args->m; 578 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 579 struct tcphdr *tcp; 580 tcp = (struct tcphdr *)((char *)ip6 + hlen); 581 582 if ((tcp->th_flags & TH_RST) == 0) { 583 struct mbuf *m0; 584 m0 = ipfw_send_pkt(args->m, &(args->f_id), 585 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 586 tcp->th_flags | TH_RST); 587 if (m0 != NULL) 588 ip6_output(m0, NULL, NULL, 0, NULL, NULL, 589 NULL); 590 } 591 FREE_PKT(m); 592 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */ 593 #if 0 594 /* 595 * Unlike above, the mbufs need to line up with the ip6 hdr, 596 * as the contents are read. We need to m_adj() the 597 * needed amount. 598 * The mbuf will however be thrown away so we can adjust it. 599 * Remember we did an m_pullup on it already so we 600 * can make some assumptions about contiguousness. 601 */ 602 if (args->L3offset) 603 m_adj(m, args->L3offset); 604 #endif 605 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 606 } else 607 FREE_PKT(m); 608 609 args->m = NULL; 610 } 611 612 #endif /* INET6 */ 613 614 615 /* 616 * sends a reject message, consuming the mbuf passed as an argument. 617 */ 618 static void 619 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip) 620 { 621 622 #if 0 623 /* XXX When ip is not guaranteed to be at mtod() we will 624 * need to account for this */ 625 * The mbuf will however be thrown away so we can adjust it. 626 * Remember we did an m_pullup on it already so we 627 * can make some assumptions about contiguousness. 628 */ 629 if (args->L3offset) 630 m_adj(m, args->L3offset); 631 #endif 632 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */ 633 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 634 } else if (args->f_id.proto == IPPROTO_TCP) { 635 struct tcphdr *const tcp = 636 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 637 if ( (tcp->th_flags & TH_RST) == 0) { 638 struct mbuf *m; 639 m = ipfw_send_pkt(args->m, &(args->f_id), 640 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 641 tcp->th_flags | TH_RST); 642 if (m != NULL) 643 ip_output(m, NULL, NULL, 0, NULL, NULL); 644 } 645 FREE_PKT(args->m); 646 } else 647 FREE_PKT(args->m); 648 args->m = NULL; 649 } 650 651 /* 652 * Support for uid/gid/jail lookup. These tests are expensive 653 * (because we may need to look into the list of active sockets) 654 * so we cache the results. ugid_lookupp is 0 if we have not 655 * yet done a lookup, 1 if we succeeded, and -1 if we tried 656 * and failed. The function always returns the match value. 657 * We could actually spare the variable and use *uc, setting 658 * it to '(void *)check_uidgid if we have no info, NULL if 659 * we tried and failed, or any other value if successful. 660 */ 661 static int 662 check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp, 663 struct ucred **uc) 664 { 665 #ifndef __FreeBSD__ 666 /* XXX */ 667 return cred_check(insn, proto, oif, 668 dst_ip, dst_port, src_ip, src_port, 669 (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb); 670 #else /* FreeBSD */ 671 struct in_addr src_ip, dst_ip; 672 struct inpcbinfo *pi; 673 struct ipfw_flow_id *id; 674 struct inpcb *pcb, *inp; 675 struct ifnet *oif; 676 int lookupflags; 677 int match; 678 679 id = &args->f_id; 680 inp = args->inp; 681 oif = args->oif; 682 683 /* 684 * Check to see if the UDP or TCP stack supplied us with 685 * the PCB. If so, rather then holding a lock and looking 686 * up the PCB, we can use the one that was supplied. 687 */ 688 if (inp && *ugid_lookupp == 0) { 689 INP_LOCK_ASSERT(inp); 690 if (inp->inp_socket != NULL) { 691 *uc = crhold(inp->inp_cred); 692 *ugid_lookupp = 1; 693 } else 694 *ugid_lookupp = -1; 695 } 696 /* 697 * If we have already been here and the packet has no 698 * PCB entry associated with it, then we can safely 699 * assume that this is a no match. 700 */ 701 if (*ugid_lookupp == -1) 702 return (0); 703 if (id->proto == IPPROTO_TCP) { 704 lookupflags = 0; 705 pi = &V_tcbinfo; 706 } else if (id->proto == IPPROTO_UDP) { 707 lookupflags = INPLOOKUP_WILDCARD; 708 pi = &V_udbinfo; 709 } else 710 return 0; 711 lookupflags |= INPLOOKUP_RLOCKPCB; 712 match = 0; 713 if (*ugid_lookupp == 0) { 714 if (id->addr_type == 6) { 715 #ifdef INET6 716 if (oif == NULL) 717 pcb = in6_pcblookup_mbuf(pi, 718 &id->src_ip6, htons(id->src_port), 719 &id->dst_ip6, htons(id->dst_port), 720 lookupflags, oif, args->m); 721 else 722 pcb = in6_pcblookup_mbuf(pi, 723 &id->dst_ip6, htons(id->dst_port), 724 &id->src_ip6, htons(id->src_port), 725 lookupflags, oif, args->m); 726 #else 727 *ugid_lookupp = -1; 728 return (0); 729 #endif 730 } else { 731 src_ip.s_addr = htonl(id->src_ip); 732 dst_ip.s_addr = htonl(id->dst_ip); 733 if (oif == NULL) 734 pcb = in_pcblookup_mbuf(pi, 735 src_ip, htons(id->src_port), 736 dst_ip, htons(id->dst_port), 737 lookupflags, oif, args->m); 738 else 739 pcb = in_pcblookup_mbuf(pi, 740 dst_ip, htons(id->dst_port), 741 src_ip, htons(id->src_port), 742 lookupflags, oif, args->m); 743 } 744 if (pcb != NULL) { 745 INP_RLOCK_ASSERT(pcb); 746 *uc = crhold(pcb->inp_cred); 747 *ugid_lookupp = 1; 748 INP_RUNLOCK(pcb); 749 } 750 if (*ugid_lookupp == 0) { 751 /* 752 * We tried and failed, set the variable to -1 753 * so we will not try again on this packet. 754 */ 755 *ugid_lookupp = -1; 756 return (0); 757 } 758 } 759 if (insn->o.opcode == O_UID) 760 match = ((*uc)->cr_uid == (uid_t)insn->d[0]); 761 else if (insn->o.opcode == O_GID) 762 match = groupmember((gid_t)insn->d[0], *uc); 763 else if (insn->o.opcode == O_JAIL) 764 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]); 765 return (match); 766 #endif /* __FreeBSD__ */ 767 } 768 769 /* 770 * Helper function to set args with info on the rule after the matching 771 * one. slot is precise, whereas we guess rule_id as they are 772 * assigned sequentially. 773 */ 774 static inline void 775 set_match(struct ip_fw_args *args, int slot, 776 struct ip_fw_chain *chain) 777 { 778 args->rule.chain_id = chain->id; 779 args->rule.slot = slot + 1; /* we use 0 as a marker */ 780 args->rule.rule_id = 1 + chain->map[slot]->id; 781 args->rule.rulenum = chain->map[slot]->rulenum; 782 } 783 784 /* 785 * Helper function to enable cached rule lookups using 786 * x_next and next_rule fields in ipfw rule. 787 */ 788 static int 789 jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 790 int tablearg, int jump_backwards) 791 { 792 int f_pos; 793 794 /* If possible use cached f_pos (in f->next_rule), 795 * whose version is written in f->next_rule 796 * (horrible hacks to avoid changing the ABI). 797 */ 798 if (num != IP_FW_TABLEARG && (uintptr_t)f->x_next == chain->id) 799 f_pos = (uintptr_t)f->next_rule; 800 else { 801 int i = IP_FW_ARG_TABLEARG(num); 802 /* make sure we do not jump backward */ 803 if (jump_backwards == 0 && i <= f->rulenum) 804 i = f->rulenum + 1; 805 f_pos = ipfw_find_rule(chain, i, 0); 806 /* update the cache */ 807 if (num != IP_FW_TABLEARG) { 808 f->next_rule = (void *)(uintptr_t)f_pos; 809 f->x_next = (void *)(uintptr_t)chain->id; 810 } 811 } 812 813 return (f_pos); 814 } 815 816 /* 817 * The main check routine for the firewall. 818 * 819 * All arguments are in args so we can modify them and return them 820 * back to the caller. 821 * 822 * Parameters: 823 * 824 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 825 * Starts with the IP header. 826 * args->eh (in) Mac header if present, NULL for layer3 packet. 827 * args->L3offset Number of bytes bypassed if we came from L2. 828 * e.g. often sizeof(eh) ** NOTYET ** 829 * args->oif Outgoing interface, NULL if packet is incoming. 830 * The incoming interface is in the mbuf. (in) 831 * args->divert_rule (in/out) 832 * Skip up to the first rule past this rule number; 833 * upon return, non-zero port number for divert or tee. 834 * 835 * args->rule Pointer to the last matching rule (in/out) 836 * args->next_hop Socket we are forwarding to (out). 837 * args->next_hop6 IPv6 next hop we are forwarding to (out). 838 * args->f_id Addresses grabbed from the packet (out) 839 * args->rule.info a cookie depending on rule action 840 * 841 * Return value: 842 * 843 * IP_FW_PASS the packet must be accepted 844 * IP_FW_DENY the packet must be dropped 845 * IP_FW_DIVERT divert packet, port in m_tag 846 * IP_FW_TEE tee packet, port in m_tag 847 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 848 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 849 * args->rule contains the matching rule, 850 * args->rule.info has additional information. 851 * 852 */ 853 int 854 ipfw_chk(struct ip_fw_args *args) 855 { 856 857 /* 858 * Local variables holding state while processing a packet: 859 * 860 * IMPORTANT NOTE: to speed up the processing of rules, there 861 * are some assumption on the values of the variables, which 862 * are documented here. Should you change them, please check 863 * the implementation of the various instructions to make sure 864 * that they still work. 865 * 866 * args->eh The MAC header. It is non-null for a layer2 867 * packet, it is NULL for a layer-3 packet. 868 * **notyet** 869 * args->L3offset Offset in the packet to the L3 (IP or equiv.) header. 870 * 871 * m | args->m Pointer to the mbuf, as received from the caller. 872 * It may change if ipfw_chk() does an m_pullup, or if it 873 * consumes the packet because it calls send_reject(). 874 * XXX This has to change, so that ipfw_chk() never modifies 875 * or consumes the buffer. 876 * ip is the beginning of the ip(4 or 6) header. 877 * Calculated by adding the L3offset to the start of data. 878 * (Until we start using L3offset, the packet is 879 * supposed to start with the ip header). 880 */ 881 struct mbuf *m = args->m; 882 struct ip *ip = mtod(m, struct ip *); 883 884 /* 885 * For rules which contain uid/gid or jail constraints, cache 886 * a copy of the users credentials after the pcb lookup has been 887 * executed. This will speed up the processing of rules with 888 * these types of constraints, as well as decrease contention 889 * on pcb related locks. 890 */ 891 #ifndef __FreeBSD__ 892 struct bsd_ucred ucred_cache; 893 #else 894 struct ucred *ucred_cache = NULL; 895 #endif 896 int ucred_lookup = 0; 897 898 /* 899 * oif | args->oif If NULL, ipfw_chk has been called on the 900 * inbound path (ether_input, ip_input). 901 * If non-NULL, ipfw_chk has been called on the outbound path 902 * (ether_output, ip_output). 903 */ 904 struct ifnet *oif = args->oif; 905 906 int f_pos = 0; /* index of current rule in the array */ 907 int retval = 0; 908 909 /* 910 * hlen The length of the IP header. 911 */ 912 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 913 914 /* 915 * offset The offset of a fragment. offset != 0 means that 916 * we have a fragment at this offset of an IPv4 packet. 917 * offset == 0 means that (if this is an IPv4 packet) 918 * this is the first or only fragment. 919 * For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header 920 * or there is a single packet fragement (fragement header added 921 * without needed). We will treat a single packet fragment as if 922 * there was no fragment header (or log/block depending on the 923 * V_fw_permit_single_frag6 sysctl setting). 924 */ 925 u_short offset = 0; 926 u_short ip6f_mf = 0; 927 928 /* 929 * Local copies of addresses. They are only valid if we have 930 * an IP packet. 931 * 932 * proto The protocol. Set to 0 for non-ip packets, 933 * or to the protocol read from the packet otherwise. 934 * proto != 0 means that we have an IPv4 packet. 935 * 936 * src_port, dst_port port numbers, in HOST format. Only 937 * valid for TCP and UDP packets. 938 * 939 * src_ip, dst_ip ip addresses, in NETWORK format. 940 * Only valid for IPv4 packets. 941 */ 942 uint8_t proto; 943 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 944 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 945 uint16_t iplen=0; 946 int pktlen; 947 uint16_t etype = 0; /* Host order stored ether type */ 948 949 /* 950 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 951 * MATCH_NONE when checked and not matched (q = NULL), 952 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) 953 */ 954 int dyn_dir = MATCH_UNKNOWN; 955 ipfw_dyn_rule *q = NULL; 956 struct ip_fw_chain *chain = &V_layer3_chain; 957 958 /* 959 * We store in ulp a pointer to the upper layer protocol header. 960 * In the ipv4 case this is easy to determine from the header, 961 * but for ipv6 we might have some additional headers in the middle. 962 * ulp is NULL if not found. 963 */ 964 void *ulp = NULL; /* upper layer protocol pointer. */ 965 966 /* XXX ipv6 variables */ 967 int is_ipv6 = 0; 968 uint8_t icmp6_type = 0; 969 uint16_t ext_hd = 0; /* bits vector for extension header filtering */ 970 /* end of ipv6 variables */ 971 972 int is_ipv4 = 0; 973 974 int done = 0; /* flag to exit the outer loop */ 975 976 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready)) 977 return (IP_FW_PASS); /* accept */ 978 979 dst_ip.s_addr = 0; /* make sure it is initialized */ 980 src_ip.s_addr = 0; /* make sure it is initialized */ 981 pktlen = m->m_pkthdr.len; 982 args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */ 983 proto = args->f_id.proto = 0; /* mark f_id invalid */ 984 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ 985 986 /* 987 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 988 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 989 * pointer might become stale after other pullups (but we never use it 990 * this way). 991 */ 992 #define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T)) 993 #define PULLUP_LEN(_len, p, T) \ 994 do { \ 995 int x = (_len) + T; \ 996 if ((m)->m_len < x) { \ 997 args->m = m = m_pullup(m, x); \ 998 if (m == NULL) \ 999 goto pullup_failed; \ 1000 } \ 1001 p = (mtod(m, char *) + (_len)); \ 1002 } while (0) 1003 1004 /* 1005 * if we have an ether header, 1006 */ 1007 if (args->eh) 1008 etype = ntohs(args->eh->ether_type); 1009 1010 /* Identify IP packets and fill up variables. */ 1011 if (pktlen >= sizeof(struct ip6_hdr) && 1012 (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) { 1013 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 1014 is_ipv6 = 1; 1015 args->f_id.addr_type = 6; 1016 hlen = sizeof(struct ip6_hdr); 1017 proto = ip6->ip6_nxt; 1018 1019 /* Search extension headers to find upper layer protocols */ 1020 while (ulp == NULL && offset == 0) { 1021 switch (proto) { 1022 case IPPROTO_ICMPV6: 1023 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 1024 icmp6_type = ICMP6(ulp)->icmp6_type; 1025 break; 1026 1027 case IPPROTO_TCP: 1028 PULLUP_TO(hlen, ulp, struct tcphdr); 1029 dst_port = TCP(ulp)->th_dport; 1030 src_port = TCP(ulp)->th_sport; 1031 /* save flags for dynamic rules */ 1032 args->f_id._flags = TCP(ulp)->th_flags; 1033 break; 1034 1035 case IPPROTO_SCTP: 1036 PULLUP_TO(hlen, ulp, struct sctphdr); 1037 src_port = SCTP(ulp)->src_port; 1038 dst_port = SCTP(ulp)->dest_port; 1039 break; 1040 1041 case IPPROTO_UDP: 1042 PULLUP_TO(hlen, ulp, struct udphdr); 1043 dst_port = UDP(ulp)->uh_dport; 1044 src_port = UDP(ulp)->uh_sport; 1045 break; 1046 1047 case IPPROTO_HOPOPTS: /* RFC 2460 */ 1048 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1049 ext_hd |= EXT_HOPOPTS; 1050 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1051 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1052 ulp = NULL; 1053 break; 1054 1055 case IPPROTO_ROUTING: /* RFC 2460 */ 1056 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 1057 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 1058 case 0: 1059 ext_hd |= EXT_RTHDR0; 1060 break; 1061 case 2: 1062 ext_hd |= EXT_RTHDR2; 1063 break; 1064 default: 1065 if (V_fw_verbose) 1066 printf("IPFW2: IPV6 - Unknown " 1067 "Routing Header type(%d)\n", 1068 ((struct ip6_rthdr *) 1069 ulp)->ip6r_type); 1070 if (V_fw_deny_unknown_exthdrs) 1071 return (IP_FW_DENY); 1072 break; 1073 } 1074 ext_hd |= EXT_ROUTING; 1075 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 1076 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 1077 ulp = NULL; 1078 break; 1079 1080 case IPPROTO_FRAGMENT: /* RFC 2460 */ 1081 PULLUP_TO(hlen, ulp, struct ip6_frag); 1082 ext_hd |= EXT_FRAGMENT; 1083 hlen += sizeof (struct ip6_frag); 1084 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 1085 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 1086 IP6F_OFF_MASK; 1087 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg & 1088 IP6F_MORE_FRAG; 1089 if (V_fw_permit_single_frag6 == 0 && 1090 offset == 0 && ip6f_mf == 0) { 1091 if (V_fw_verbose) 1092 printf("IPFW2: IPV6 - Invalid " 1093 "Fragment Header\n"); 1094 if (V_fw_deny_unknown_exthdrs) 1095 return (IP_FW_DENY); 1096 break; 1097 } 1098 args->f_id.extra = 1099 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 1100 ulp = NULL; 1101 break; 1102 1103 case IPPROTO_DSTOPTS: /* RFC 2460 */ 1104 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1105 ext_hd |= EXT_DSTOPTS; 1106 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1107 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1108 ulp = NULL; 1109 break; 1110 1111 case IPPROTO_AH: /* RFC 2402 */ 1112 PULLUP_TO(hlen, ulp, struct ip6_ext); 1113 ext_hd |= EXT_AH; 1114 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 1115 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 1116 ulp = NULL; 1117 break; 1118 1119 case IPPROTO_ESP: /* RFC 2406 */ 1120 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 1121 /* Anything past Seq# is variable length and 1122 * data past this ext. header is encrypted. */ 1123 ext_hd |= EXT_ESP; 1124 break; 1125 1126 case IPPROTO_NONE: /* RFC 2460 */ 1127 /* 1128 * Packet ends here, and IPv6 header has 1129 * already been pulled up. If ip6e_len!=0 1130 * then octets must be ignored. 1131 */ 1132 ulp = ip; /* non-NULL to get out of loop. */ 1133 break; 1134 1135 case IPPROTO_OSPFIGP: 1136 /* XXX OSPF header check? */ 1137 PULLUP_TO(hlen, ulp, struct ip6_ext); 1138 break; 1139 1140 case IPPROTO_PIM: 1141 /* XXX PIM header check? */ 1142 PULLUP_TO(hlen, ulp, struct pim); 1143 break; 1144 1145 case IPPROTO_CARP: 1146 PULLUP_TO(hlen, ulp, struct carp_header); 1147 if (((struct carp_header *)ulp)->carp_version != 1148 CARP_VERSION) 1149 return (IP_FW_DENY); 1150 if (((struct carp_header *)ulp)->carp_type != 1151 CARP_ADVERTISEMENT) 1152 return (IP_FW_DENY); 1153 break; 1154 1155 case IPPROTO_IPV6: /* RFC 2893 */ 1156 PULLUP_TO(hlen, ulp, struct ip6_hdr); 1157 break; 1158 1159 case IPPROTO_IPV4: /* RFC 2893 */ 1160 PULLUP_TO(hlen, ulp, struct ip); 1161 break; 1162 1163 default: 1164 if (V_fw_verbose) 1165 printf("IPFW2: IPV6 - Unknown " 1166 "Extension Header(%d), ext_hd=%x\n", 1167 proto, ext_hd); 1168 if (V_fw_deny_unknown_exthdrs) 1169 return (IP_FW_DENY); 1170 PULLUP_TO(hlen, ulp, struct ip6_ext); 1171 break; 1172 } /*switch */ 1173 } 1174 ip = mtod(m, struct ip *); 1175 ip6 = (struct ip6_hdr *)ip; 1176 args->f_id.src_ip6 = ip6->ip6_src; 1177 args->f_id.dst_ip6 = ip6->ip6_dst; 1178 args->f_id.src_ip = 0; 1179 args->f_id.dst_ip = 0; 1180 args->f_id.flow_id6 = ntohl(ip6->ip6_flow); 1181 } else if (pktlen >= sizeof(struct ip) && 1182 (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) { 1183 is_ipv4 = 1; 1184 hlen = ip->ip_hl << 2; 1185 args->f_id.addr_type = 4; 1186 1187 /* 1188 * Collect parameters into local variables for faster matching. 1189 */ 1190 proto = ip->ip_p; 1191 src_ip = ip->ip_src; 1192 dst_ip = ip->ip_dst; 1193 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1194 iplen = ntohs(ip->ip_len); 1195 pktlen = iplen < pktlen ? iplen : pktlen; 1196 1197 if (offset == 0) { 1198 switch (proto) { 1199 case IPPROTO_TCP: 1200 PULLUP_TO(hlen, ulp, struct tcphdr); 1201 dst_port = TCP(ulp)->th_dport; 1202 src_port = TCP(ulp)->th_sport; 1203 /* save flags for dynamic rules */ 1204 args->f_id._flags = TCP(ulp)->th_flags; 1205 break; 1206 1207 case IPPROTO_SCTP: 1208 PULLUP_TO(hlen, ulp, struct sctphdr); 1209 src_port = SCTP(ulp)->src_port; 1210 dst_port = SCTP(ulp)->dest_port; 1211 break; 1212 1213 case IPPROTO_UDP: 1214 PULLUP_TO(hlen, ulp, struct udphdr); 1215 dst_port = UDP(ulp)->uh_dport; 1216 src_port = UDP(ulp)->uh_sport; 1217 break; 1218 1219 case IPPROTO_ICMP: 1220 PULLUP_TO(hlen, ulp, struct icmphdr); 1221 //args->f_id.flags = ICMP(ulp)->icmp_type; 1222 break; 1223 1224 default: 1225 break; 1226 } 1227 } 1228 1229 ip = mtod(m, struct ip *); 1230 args->f_id.src_ip = ntohl(src_ip.s_addr); 1231 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1232 } 1233 #undef PULLUP_TO 1234 if (proto) { /* we may have port numbers, store them */ 1235 args->f_id.proto = proto; 1236 args->f_id.src_port = src_port = ntohs(src_port); 1237 args->f_id.dst_port = dst_port = ntohs(dst_port); 1238 } 1239 1240 IPFW_PF_RLOCK(chain); 1241 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ 1242 IPFW_PF_RUNLOCK(chain); 1243 return (IP_FW_PASS); /* accept */ 1244 } 1245 if (args->rule.slot) { 1246 /* 1247 * Packet has already been tagged as a result of a previous 1248 * match on rule args->rule aka args->rule_id (PIPE, QUEUE, 1249 * REASS, NETGRAPH, DIVERT/TEE...) 1250 * Validate the slot and continue from the next one 1251 * if still present, otherwise do a lookup. 1252 */ 1253 f_pos = (args->rule.chain_id == chain->id) ? 1254 args->rule.slot : 1255 ipfw_find_rule(chain, args->rule.rulenum, 1256 args->rule.rule_id); 1257 } else { 1258 f_pos = 0; 1259 } 1260 1261 /* 1262 * Now scan the rules, and parse microinstructions for each rule. 1263 * We have two nested loops and an inner switch. Sometimes we 1264 * need to break out of one or both loops, or re-enter one of 1265 * the loops with updated variables. Loop variables are: 1266 * 1267 * f_pos (outer loop) points to the current rule. 1268 * On output it points to the matching rule. 1269 * done (outer loop) is used as a flag to break the loop. 1270 * l (inner loop) residual length of current rule. 1271 * cmd points to the current microinstruction. 1272 * 1273 * We break the inner loop by setting l=0 and possibly 1274 * cmdlen=0 if we don't want to advance cmd. 1275 * We break the outer loop by setting done=1 1276 * We can restart the inner loop by setting l>0 and f_pos, f, cmd 1277 * as needed. 1278 */ 1279 for (; f_pos < chain->n_rules; f_pos++) { 1280 ipfw_insn *cmd; 1281 uint32_t tablearg = 0; 1282 int l, cmdlen, skip_or; /* skip rest of OR block */ 1283 struct ip_fw *f; 1284 1285 f = chain->map[f_pos]; 1286 if (V_set_disable & (1 << f->set) ) 1287 continue; 1288 1289 skip_or = 0; 1290 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 1291 l -= cmdlen, cmd += cmdlen) { 1292 int match; 1293 1294 /* 1295 * check_body is a jump target used when we find a 1296 * CHECK_STATE, and need to jump to the body of 1297 * the target rule. 1298 */ 1299 1300 /* check_body: */ 1301 cmdlen = F_LEN(cmd); 1302 /* 1303 * An OR block (insn_1 || .. || insn_n) has the 1304 * F_OR bit set in all but the last instruction. 1305 * The first match will set "skip_or", and cause 1306 * the following instructions to be skipped until 1307 * past the one with the F_OR bit clear. 1308 */ 1309 if (skip_or) { /* skip this instruction */ 1310 if ((cmd->len & F_OR) == 0) 1311 skip_or = 0; /* next one is good */ 1312 continue; 1313 } 1314 match = 0; /* set to 1 if we succeed */ 1315 1316 switch (cmd->opcode) { 1317 /* 1318 * The first set of opcodes compares the packet's 1319 * fields with some pattern, setting 'match' if a 1320 * match is found. At the end of the loop there is 1321 * logic to deal with F_NOT and F_OR flags associated 1322 * with the opcode. 1323 */ 1324 case O_NOP: 1325 match = 1; 1326 break; 1327 1328 case O_FORWARD_MAC: 1329 printf("ipfw: opcode %d unimplemented\n", 1330 cmd->opcode); 1331 break; 1332 1333 case O_GID: 1334 case O_UID: 1335 case O_JAIL: 1336 /* 1337 * We only check offset == 0 && proto != 0, 1338 * as this ensures that we have a 1339 * packet with the ports info. 1340 */ 1341 if (offset != 0) 1342 break; 1343 if (proto == IPPROTO_TCP || 1344 proto == IPPROTO_UDP) 1345 match = check_uidgid( 1346 (ipfw_insn_u32 *)cmd, 1347 args, &ucred_lookup, 1348 #ifdef __FreeBSD__ 1349 &ucred_cache); 1350 #else 1351 (void *)&ucred_cache); 1352 #endif 1353 break; 1354 1355 case O_RECV: 1356 match = iface_match(m->m_pkthdr.rcvif, 1357 (ipfw_insn_if *)cmd, chain, &tablearg); 1358 break; 1359 1360 case O_XMIT: 1361 match = iface_match(oif, (ipfw_insn_if *)cmd, 1362 chain, &tablearg); 1363 break; 1364 1365 case O_VIA: 1366 match = iface_match(oif ? oif : 1367 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd, 1368 chain, &tablearg); 1369 break; 1370 1371 case O_MACADDR2: 1372 if (args->eh != NULL) { /* have MAC header */ 1373 u_int32_t *want = (u_int32_t *) 1374 ((ipfw_insn_mac *)cmd)->addr; 1375 u_int32_t *mask = (u_int32_t *) 1376 ((ipfw_insn_mac *)cmd)->mask; 1377 u_int32_t *hdr = (u_int32_t *)args->eh; 1378 1379 match = 1380 ( want[0] == (hdr[0] & mask[0]) && 1381 want[1] == (hdr[1] & mask[1]) && 1382 want[2] == (hdr[2] & mask[2]) ); 1383 } 1384 break; 1385 1386 case O_MAC_TYPE: 1387 if (args->eh != NULL) { 1388 u_int16_t *p = 1389 ((ipfw_insn_u16 *)cmd)->ports; 1390 int i; 1391 1392 for (i = cmdlen - 1; !match && i>0; 1393 i--, p += 2) 1394 match = (etype >= p[0] && 1395 etype <= p[1]); 1396 } 1397 break; 1398 1399 case O_FRAG: 1400 match = (offset != 0); 1401 break; 1402 1403 case O_IN: /* "out" is "not in" */ 1404 match = (oif == NULL); 1405 break; 1406 1407 case O_LAYER2: 1408 match = (args->eh != NULL); 1409 break; 1410 1411 case O_DIVERTED: 1412 { 1413 /* For diverted packets, args->rule.info 1414 * contains the divert port (in host format) 1415 * reason and direction. 1416 */ 1417 uint32_t i = args->rule.info; 1418 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT && 1419 cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2); 1420 } 1421 break; 1422 1423 case O_PROTO: 1424 /* 1425 * We do not allow an arg of 0 so the 1426 * check of "proto" only suffices. 1427 */ 1428 match = (proto == cmd->arg1); 1429 break; 1430 1431 case O_IP_SRC: 1432 match = is_ipv4 && 1433 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1434 src_ip.s_addr); 1435 break; 1436 1437 case O_IP_SRC_LOOKUP: 1438 case O_IP_DST_LOOKUP: 1439 if (is_ipv4) { 1440 uint32_t key = 1441 (cmd->opcode == O_IP_DST_LOOKUP) ? 1442 dst_ip.s_addr : src_ip.s_addr; 1443 uint32_t v = 0; 1444 1445 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { 1446 /* generic lookup. The key must be 1447 * in 32bit big-endian format. 1448 */ 1449 v = ((ipfw_insn_u32 *)cmd)->d[1]; 1450 if (v == 0) 1451 key = dst_ip.s_addr; 1452 else if (v == 1) 1453 key = src_ip.s_addr; 1454 else if (v == 6) /* dscp */ 1455 key = (ip->ip_tos >> 2) & 0x3f; 1456 else if (offset != 0) 1457 break; 1458 else if (proto != IPPROTO_TCP && 1459 proto != IPPROTO_UDP) 1460 break; 1461 else if (v == 2) 1462 key = htonl(dst_port); 1463 else if (v == 3) 1464 key = htonl(src_port); 1465 else if (v == 4 || v == 5) { 1466 check_uidgid( 1467 (ipfw_insn_u32 *)cmd, 1468 args, &ucred_lookup, 1469 #ifdef __FreeBSD__ 1470 &ucred_cache); 1471 if (v == 4 /* O_UID */) 1472 key = ucred_cache->cr_uid; 1473 else if (v == 5 /* O_JAIL */) 1474 key = ucred_cache->cr_prison->pr_id; 1475 #else /* !__FreeBSD__ */ 1476 (void *)&ucred_cache); 1477 if (v ==4 /* O_UID */) 1478 key = ucred_cache.uid; 1479 else if (v == 5 /* O_JAIL */) 1480 key = ucred_cache.xid; 1481 #endif /* !__FreeBSD__ */ 1482 key = htonl(key); 1483 } else 1484 break; 1485 } 1486 match = ipfw_lookup_table(chain, 1487 cmd->arg1, key, &v); 1488 if (!match) 1489 break; 1490 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1491 match = 1492 ((ipfw_insn_u32 *)cmd)->d[0] == v; 1493 else 1494 tablearg = v; 1495 } else if (is_ipv6) { 1496 uint32_t v = 0; 1497 void *pkey = (cmd->opcode == O_IP_DST_LOOKUP) ? 1498 &args->f_id.dst_ip6: &args->f_id.src_ip6; 1499 match = ipfw_lookup_table_extended(chain, 1500 cmd->arg1, pkey, &v, 1501 IPFW_TABLE_CIDR); 1502 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1503 match = ((ipfw_insn_u32 *)cmd)->d[0] == v; 1504 if (match) 1505 tablearg = v; 1506 } 1507 break; 1508 1509 case O_IP_SRC_MASK: 1510 case O_IP_DST_MASK: 1511 if (is_ipv4) { 1512 uint32_t a = 1513 (cmd->opcode == O_IP_DST_MASK) ? 1514 dst_ip.s_addr : src_ip.s_addr; 1515 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 1516 int i = cmdlen-1; 1517 1518 for (; !match && i>0; i-= 2, p+= 2) 1519 match = (p[0] == (a & p[1])); 1520 } 1521 break; 1522 1523 case O_IP_SRC_ME: 1524 if (is_ipv4) { 1525 struct ifnet *tif; 1526 1527 INADDR_TO_IFP(src_ip, tif); 1528 match = (tif != NULL); 1529 break; 1530 } 1531 #ifdef INET6 1532 /* FALLTHROUGH */ 1533 case O_IP6_SRC_ME: 1534 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6); 1535 #endif 1536 break; 1537 1538 case O_IP_DST_SET: 1539 case O_IP_SRC_SET: 1540 if (is_ipv4) { 1541 u_int32_t *d = (u_int32_t *)(cmd+1); 1542 u_int32_t addr = 1543 cmd->opcode == O_IP_DST_SET ? 1544 args->f_id.dst_ip : 1545 args->f_id.src_ip; 1546 1547 if (addr < d[0]) 1548 break; 1549 addr -= d[0]; /* subtract base */ 1550 match = (addr < cmd->arg1) && 1551 ( d[ 1 + (addr>>5)] & 1552 (1<<(addr & 0x1f)) ); 1553 } 1554 break; 1555 1556 case O_IP_DST: 1557 match = is_ipv4 && 1558 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1559 dst_ip.s_addr); 1560 break; 1561 1562 case O_IP_DST_ME: 1563 if (is_ipv4) { 1564 struct ifnet *tif; 1565 1566 INADDR_TO_IFP(dst_ip, tif); 1567 match = (tif != NULL); 1568 break; 1569 } 1570 #ifdef INET6 1571 /* FALLTHROUGH */ 1572 case O_IP6_DST_ME: 1573 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6); 1574 #endif 1575 break; 1576 1577 1578 case O_IP_SRCPORT: 1579 case O_IP_DSTPORT: 1580 /* 1581 * offset == 0 && proto != 0 is enough 1582 * to guarantee that we have a 1583 * packet with port info. 1584 */ 1585 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP) 1586 && offset == 0) { 1587 u_int16_t x = 1588 (cmd->opcode == O_IP_SRCPORT) ? 1589 src_port : dst_port ; 1590 u_int16_t *p = 1591 ((ipfw_insn_u16 *)cmd)->ports; 1592 int i; 1593 1594 for (i = cmdlen - 1; !match && i>0; 1595 i--, p += 2) 1596 match = (x>=p[0] && x<=p[1]); 1597 } 1598 break; 1599 1600 case O_ICMPTYPE: 1601 match = (offset == 0 && proto==IPPROTO_ICMP && 1602 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 1603 break; 1604 1605 #ifdef INET6 1606 case O_ICMP6TYPE: 1607 match = is_ipv6 && offset == 0 && 1608 proto==IPPROTO_ICMPV6 && 1609 icmp6type_match( 1610 ICMP6(ulp)->icmp6_type, 1611 (ipfw_insn_u32 *)cmd); 1612 break; 1613 #endif /* INET6 */ 1614 1615 case O_IPOPT: 1616 match = (is_ipv4 && 1617 ipopts_match(ip, cmd) ); 1618 break; 1619 1620 case O_IPVER: 1621 match = (is_ipv4 && 1622 cmd->arg1 == ip->ip_v); 1623 break; 1624 1625 case O_IPID: 1626 case O_IPLEN: 1627 case O_IPTTL: 1628 if (is_ipv4) { /* only for IP packets */ 1629 uint16_t x; 1630 uint16_t *p; 1631 int i; 1632 1633 if (cmd->opcode == O_IPLEN) 1634 x = iplen; 1635 else if (cmd->opcode == O_IPTTL) 1636 x = ip->ip_ttl; 1637 else /* must be IPID */ 1638 x = ntohs(ip->ip_id); 1639 if (cmdlen == 1) { 1640 match = (cmd->arg1 == x); 1641 break; 1642 } 1643 /* otherwise we have ranges */ 1644 p = ((ipfw_insn_u16 *)cmd)->ports; 1645 i = cmdlen - 1; 1646 for (; !match && i>0; i--, p += 2) 1647 match = (x >= p[0] && x <= p[1]); 1648 } 1649 break; 1650 1651 case O_IPPRECEDENCE: 1652 match = (is_ipv4 && 1653 (cmd->arg1 == (ip->ip_tos & 0xe0)) ); 1654 break; 1655 1656 case O_IPTOS: 1657 match = (is_ipv4 && 1658 flags_match(cmd, ip->ip_tos)); 1659 break; 1660 1661 case O_DSCP: 1662 { 1663 uint32_t *p; 1664 uint16_t x; 1665 1666 p = ((ipfw_insn_u32 *)cmd)->d; 1667 1668 if (is_ipv4) 1669 x = ip->ip_tos >> 2; 1670 else if (is_ipv6) { 1671 uint8_t *v; 1672 v = &((struct ip6_hdr *)ip)->ip6_vfc; 1673 x = (*v & 0x0F) << 2; 1674 v++; 1675 x |= *v >> 6; 1676 } else 1677 break; 1678 1679 /* DSCP bitmask is stored as low_u32 high_u32 */ 1680 if (x > 32) 1681 match = *(p + 1) & (1 << (x - 32)); 1682 else 1683 match = *p & (1 << x); 1684 } 1685 break; 1686 1687 case O_TCPDATALEN: 1688 if (proto == IPPROTO_TCP && offset == 0) { 1689 struct tcphdr *tcp; 1690 uint16_t x; 1691 uint16_t *p; 1692 int i; 1693 1694 tcp = TCP(ulp); 1695 x = iplen - 1696 ((ip->ip_hl + tcp->th_off) << 2); 1697 if (cmdlen == 1) { 1698 match = (cmd->arg1 == x); 1699 break; 1700 } 1701 /* otherwise we have ranges */ 1702 p = ((ipfw_insn_u16 *)cmd)->ports; 1703 i = cmdlen - 1; 1704 for (; !match && i>0; i--, p += 2) 1705 match = (x >= p[0] && x <= p[1]); 1706 } 1707 break; 1708 1709 case O_TCPFLAGS: 1710 match = (proto == IPPROTO_TCP && offset == 0 && 1711 flags_match(cmd, TCP(ulp)->th_flags)); 1712 break; 1713 1714 case O_TCPOPTS: 1715 PULLUP_LEN(hlen, ulp, (TCP(ulp)->th_off << 2)); 1716 match = (proto == IPPROTO_TCP && offset == 0 && 1717 tcpopts_match(TCP(ulp), cmd)); 1718 break; 1719 1720 case O_TCPSEQ: 1721 match = (proto == IPPROTO_TCP && offset == 0 && 1722 ((ipfw_insn_u32 *)cmd)->d[0] == 1723 TCP(ulp)->th_seq); 1724 break; 1725 1726 case O_TCPACK: 1727 match = (proto == IPPROTO_TCP && offset == 0 && 1728 ((ipfw_insn_u32 *)cmd)->d[0] == 1729 TCP(ulp)->th_ack); 1730 break; 1731 1732 case O_TCPWIN: 1733 if (proto == IPPROTO_TCP && offset == 0) { 1734 uint16_t x; 1735 uint16_t *p; 1736 int i; 1737 1738 x = ntohs(TCP(ulp)->th_win); 1739 if (cmdlen == 1) { 1740 match = (cmd->arg1 == x); 1741 break; 1742 } 1743 /* Otherwise we have ranges. */ 1744 p = ((ipfw_insn_u16 *)cmd)->ports; 1745 i = cmdlen - 1; 1746 for (; !match && i > 0; i--, p += 2) 1747 match = (x >= p[0] && x <= p[1]); 1748 } 1749 break; 1750 1751 case O_ESTAB: 1752 /* reject packets which have SYN only */ 1753 /* XXX should i also check for TH_ACK ? */ 1754 match = (proto == IPPROTO_TCP && offset == 0 && 1755 (TCP(ulp)->th_flags & 1756 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 1757 break; 1758 1759 case O_ALTQ: { 1760 struct pf_mtag *at; 1761 struct m_tag *mtag; 1762 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 1763 1764 /* 1765 * ALTQ uses mbuf tags from another 1766 * packet filtering system - pf(4). 1767 * We allocate a tag in its format 1768 * and fill it in, pretending to be pf(4). 1769 */ 1770 match = 1; 1771 at = pf_find_mtag(m); 1772 if (at != NULL && at->qid != 0) 1773 break; 1774 mtag = m_tag_get(PACKET_TAG_PF, 1775 sizeof(struct pf_mtag), M_NOWAIT | M_ZERO); 1776 if (mtag == NULL) { 1777 /* 1778 * Let the packet fall back to the 1779 * default ALTQ. 1780 */ 1781 break; 1782 } 1783 m_tag_prepend(m, mtag); 1784 at = (struct pf_mtag *)(mtag + 1); 1785 at->qid = altq->qid; 1786 at->hdr = ip; 1787 break; 1788 } 1789 1790 case O_LOG: 1791 ipfw_log(f, hlen, args, m, 1792 oif, offset | ip6f_mf, tablearg, ip); 1793 match = 1; 1794 break; 1795 1796 case O_PROB: 1797 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 1798 break; 1799 1800 case O_VERREVPATH: 1801 /* Outgoing packets automatically pass/match */ 1802 match = ((oif != NULL) || 1803 (m->m_pkthdr.rcvif == NULL) || 1804 ( 1805 #ifdef INET6 1806 is_ipv6 ? 1807 verify_path6(&(args->f_id.src_ip6), 1808 m->m_pkthdr.rcvif, args->f_id.fib) : 1809 #endif 1810 verify_path(src_ip, m->m_pkthdr.rcvif, 1811 args->f_id.fib))); 1812 break; 1813 1814 case O_VERSRCREACH: 1815 /* Outgoing packets automatically pass/match */ 1816 match = (hlen > 0 && ((oif != NULL) || 1817 #ifdef INET6 1818 is_ipv6 ? 1819 verify_path6(&(args->f_id.src_ip6), 1820 NULL, args->f_id.fib) : 1821 #endif 1822 verify_path(src_ip, NULL, args->f_id.fib))); 1823 break; 1824 1825 case O_ANTISPOOF: 1826 /* Outgoing packets automatically pass/match */ 1827 if (oif == NULL && hlen > 0 && 1828 ( (is_ipv4 && in_localaddr(src_ip)) 1829 #ifdef INET6 1830 || (is_ipv6 && 1831 in6_localaddr(&(args->f_id.src_ip6))) 1832 #endif 1833 )) 1834 match = 1835 #ifdef INET6 1836 is_ipv6 ? verify_path6( 1837 &(args->f_id.src_ip6), 1838 m->m_pkthdr.rcvif, 1839 args->f_id.fib) : 1840 #endif 1841 verify_path(src_ip, 1842 m->m_pkthdr.rcvif, 1843 args->f_id.fib); 1844 else 1845 match = 1; 1846 break; 1847 1848 case O_IPSEC: 1849 #ifdef IPSEC 1850 match = (m_tag_find(m, 1851 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 1852 #endif 1853 /* otherwise no match */ 1854 break; 1855 1856 #ifdef INET6 1857 case O_IP6_SRC: 1858 match = is_ipv6 && 1859 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 1860 &((ipfw_insn_ip6 *)cmd)->addr6); 1861 break; 1862 1863 case O_IP6_DST: 1864 match = is_ipv6 && 1865 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 1866 &((ipfw_insn_ip6 *)cmd)->addr6); 1867 break; 1868 case O_IP6_SRC_MASK: 1869 case O_IP6_DST_MASK: 1870 if (is_ipv6) { 1871 int i = cmdlen - 1; 1872 struct in6_addr p; 1873 struct in6_addr *d = 1874 &((ipfw_insn_ip6 *)cmd)->addr6; 1875 1876 for (; !match && i > 0; d += 2, 1877 i -= F_INSN_SIZE(struct in6_addr) 1878 * 2) { 1879 p = (cmd->opcode == 1880 O_IP6_SRC_MASK) ? 1881 args->f_id.src_ip6: 1882 args->f_id.dst_ip6; 1883 APPLY_MASK(&p, &d[1]); 1884 match = 1885 IN6_ARE_ADDR_EQUAL(&d[0], 1886 &p); 1887 } 1888 } 1889 break; 1890 1891 case O_FLOW6ID: 1892 match = is_ipv6 && 1893 flow6id_match(args->f_id.flow_id6, 1894 (ipfw_insn_u32 *) cmd); 1895 break; 1896 1897 case O_EXT_HDR: 1898 match = is_ipv6 && 1899 (ext_hd & ((ipfw_insn *) cmd)->arg1); 1900 break; 1901 1902 case O_IP6: 1903 match = is_ipv6; 1904 break; 1905 #endif 1906 1907 case O_IP4: 1908 match = is_ipv4; 1909 break; 1910 1911 case O_TAG: { 1912 struct m_tag *mtag; 1913 uint32_t tag = IP_FW_ARG_TABLEARG(cmd->arg1); 1914 1915 /* Packet is already tagged with this tag? */ 1916 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 1917 1918 /* We have `untag' action when F_NOT flag is 1919 * present. And we must remove this mtag from 1920 * mbuf and reset `match' to zero (`match' will 1921 * be inversed later). 1922 * Otherwise we should allocate new mtag and 1923 * push it into mbuf. 1924 */ 1925 if (cmd->len & F_NOT) { /* `untag' action */ 1926 if (mtag != NULL) 1927 m_tag_delete(m, mtag); 1928 match = 0; 1929 } else { 1930 if (mtag == NULL) { 1931 mtag = m_tag_alloc( MTAG_IPFW, 1932 tag, 0, M_NOWAIT); 1933 if (mtag != NULL) 1934 m_tag_prepend(m, mtag); 1935 } 1936 match = 1; 1937 } 1938 break; 1939 } 1940 1941 case O_FIB: /* try match the specified fib */ 1942 if (args->f_id.fib == cmd->arg1) 1943 match = 1; 1944 break; 1945 1946 case O_SOCKARG: { 1947 struct inpcb *inp = args->inp; 1948 struct inpcbinfo *pi; 1949 1950 if (is_ipv6) /* XXX can we remove this ? */ 1951 break; 1952 1953 if (proto == IPPROTO_TCP) 1954 pi = &V_tcbinfo; 1955 else if (proto == IPPROTO_UDP) 1956 pi = &V_udbinfo; 1957 else 1958 break; 1959 1960 /* 1961 * XXXRW: so_user_cookie should almost 1962 * certainly be inp_user_cookie? 1963 */ 1964 1965 /* For incomming packet, lookup up the 1966 inpcb using the src/dest ip/port tuple */ 1967 if (inp == NULL) { 1968 inp = in_pcblookup(pi, 1969 src_ip, htons(src_port), 1970 dst_ip, htons(dst_port), 1971 INPLOOKUP_RLOCKPCB, NULL); 1972 if (inp != NULL) { 1973 tablearg = 1974 inp->inp_socket->so_user_cookie; 1975 if (tablearg) 1976 match = 1; 1977 INP_RUNLOCK(inp); 1978 } 1979 } else { 1980 if (inp->inp_socket) { 1981 tablearg = 1982 inp->inp_socket->so_user_cookie; 1983 if (tablearg) 1984 match = 1; 1985 } 1986 } 1987 break; 1988 } 1989 1990 case O_TAGGED: { 1991 struct m_tag *mtag; 1992 uint32_t tag = IP_FW_ARG_TABLEARG(cmd->arg1); 1993 1994 if (cmdlen == 1) { 1995 match = m_tag_locate(m, MTAG_IPFW, 1996 tag, NULL) != NULL; 1997 break; 1998 } 1999 2000 /* we have ranges */ 2001 for (mtag = m_tag_first(m); 2002 mtag != NULL && !match; 2003 mtag = m_tag_next(m, mtag)) { 2004 uint16_t *p; 2005 int i; 2006 2007 if (mtag->m_tag_cookie != MTAG_IPFW) 2008 continue; 2009 2010 p = ((ipfw_insn_u16 *)cmd)->ports; 2011 i = cmdlen - 1; 2012 for(; !match && i > 0; i--, p += 2) 2013 match = 2014 mtag->m_tag_id >= p[0] && 2015 mtag->m_tag_id <= p[1]; 2016 } 2017 break; 2018 } 2019 2020 /* 2021 * The second set of opcodes represents 'actions', 2022 * i.e. the terminal part of a rule once the packet 2023 * matches all previous patterns. 2024 * Typically there is only one action for each rule, 2025 * and the opcode is stored at the end of the rule 2026 * (but there are exceptions -- see below). 2027 * 2028 * In general, here we set retval and terminate the 2029 * outer loop (would be a 'break 3' in some language, 2030 * but we need to set l=0, done=1) 2031 * 2032 * Exceptions: 2033 * O_COUNT and O_SKIPTO actions: 2034 * instead of terminating, we jump to the next rule 2035 * (setting l=0), or to the SKIPTO target (setting 2036 * f/f_len, cmd and l as needed), respectively. 2037 * 2038 * O_TAG, O_LOG and O_ALTQ action parameters: 2039 * perform some action and set match = 1; 2040 * 2041 * O_LIMIT and O_KEEP_STATE: these opcodes are 2042 * not real 'actions', and are stored right 2043 * before the 'action' part of the rule. 2044 * These opcodes try to install an entry in the 2045 * state tables; if successful, we continue with 2046 * the next opcode (match=1; break;), otherwise 2047 * the packet must be dropped (set retval, 2048 * break loops with l=0, done=1) 2049 * 2050 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2051 * cause a lookup of the state table, and a jump 2052 * to the 'action' part of the parent rule 2053 * if an entry is found, or 2054 * (CHECK_STATE only) a jump to the next rule if 2055 * the entry is not found. 2056 * The result of the lookup is cached so that 2057 * further instances of these opcodes become NOPs. 2058 * The jump to the next rule is done by setting 2059 * l=0, cmdlen=0. 2060 */ 2061 case O_LIMIT: 2062 case O_KEEP_STATE: 2063 if (ipfw_install_state(f, 2064 (ipfw_insn_limit *)cmd, args, tablearg)) { 2065 /* error or limit violation */ 2066 retval = IP_FW_DENY; 2067 l = 0; /* exit inner loop */ 2068 done = 1; /* exit outer loop */ 2069 } 2070 match = 1; 2071 break; 2072 2073 case O_PROBE_STATE: 2074 case O_CHECK_STATE: 2075 /* 2076 * dynamic rules are checked at the first 2077 * keep-state or check-state occurrence, 2078 * with the result being stored in dyn_dir. 2079 * The compiler introduces a PROBE_STATE 2080 * instruction for us when we have a 2081 * KEEP_STATE (because PROBE_STATE needs 2082 * to be run first). 2083 */ 2084 if (dyn_dir == MATCH_UNKNOWN && 2085 (q = ipfw_lookup_dyn_rule(&args->f_id, 2086 &dyn_dir, proto == IPPROTO_TCP ? 2087 TCP(ulp) : NULL)) 2088 != NULL) { 2089 /* 2090 * Found dynamic entry, update stats 2091 * and jump to the 'action' part of 2092 * the parent rule by setting 2093 * f, cmd, l and clearing cmdlen. 2094 */ 2095 IPFW_INC_DYN_COUNTER(q, pktlen); 2096 /* XXX we would like to have f_pos 2097 * readily accessible in the dynamic 2098 * rule, instead of having to 2099 * lookup q->rule. 2100 */ 2101 f = q->rule; 2102 f_pos = ipfw_find_rule(chain, 2103 f->rulenum, f->id); 2104 cmd = ACTION_PTR(f); 2105 l = f->cmd_len - f->act_ofs; 2106 ipfw_dyn_unlock(q); 2107 cmdlen = 0; 2108 match = 1; 2109 break; 2110 } 2111 /* 2112 * Dynamic entry not found. If CHECK_STATE, 2113 * skip to next rule, if PROBE_STATE just 2114 * ignore and continue with next opcode. 2115 */ 2116 if (cmd->opcode == O_CHECK_STATE) 2117 l = 0; /* exit inner loop */ 2118 match = 1; 2119 break; 2120 2121 case O_ACCEPT: 2122 retval = 0; /* accept */ 2123 l = 0; /* exit inner loop */ 2124 done = 1; /* exit outer loop */ 2125 break; 2126 2127 case O_PIPE: 2128 case O_QUEUE: 2129 set_match(args, f_pos, chain); 2130 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1); 2131 if (cmd->opcode == O_PIPE) 2132 args->rule.info |= IPFW_IS_PIPE; 2133 if (V_fw_one_pass) 2134 args->rule.info |= IPFW_ONEPASS; 2135 retval = IP_FW_DUMMYNET; 2136 l = 0; /* exit inner loop */ 2137 done = 1; /* exit outer loop */ 2138 break; 2139 2140 case O_DIVERT: 2141 case O_TEE: 2142 if (args->eh) /* not on layer 2 */ 2143 break; 2144 /* otherwise this is terminal */ 2145 l = 0; /* exit inner loop */ 2146 done = 1; /* exit outer loop */ 2147 retval = (cmd->opcode == O_DIVERT) ? 2148 IP_FW_DIVERT : IP_FW_TEE; 2149 set_match(args, f_pos, chain); 2150 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1); 2151 break; 2152 2153 case O_COUNT: 2154 IPFW_INC_RULE_COUNTER(f, pktlen); 2155 l = 0; /* exit inner loop */ 2156 break; 2157 2158 case O_SKIPTO: 2159 IPFW_INC_RULE_COUNTER(f, pktlen); 2160 f_pos = jump_fast(chain, f, cmd->arg1, tablearg, 0); 2161 /* 2162 * Skip disabled rules, and re-enter 2163 * the inner loop with the correct 2164 * f_pos, f, l and cmd. 2165 * Also clear cmdlen and skip_or 2166 */ 2167 for (; f_pos < chain->n_rules - 1 && 2168 (V_set_disable & 2169 (1 << chain->map[f_pos]->set)); 2170 f_pos++) 2171 ; 2172 /* Re-enter the inner loop at the skipto rule. */ 2173 f = chain->map[f_pos]; 2174 l = f->cmd_len; 2175 cmd = f->cmd; 2176 match = 1; 2177 cmdlen = 0; 2178 skip_or = 0; 2179 continue; 2180 break; /* not reached */ 2181 2182 case O_CALLRETURN: { 2183 /* 2184 * Implementation of `subroutine' call/return, 2185 * in the stack carried in an mbuf tag. This 2186 * is different from `skipto' in that any call 2187 * address is possible (`skipto' must prevent 2188 * backward jumps to avoid endless loops). 2189 * We have `return' action when F_NOT flag is 2190 * present. The `m_tag_id' field is used as 2191 * stack pointer. 2192 */ 2193 struct m_tag *mtag; 2194 uint16_t jmpto, *stack; 2195 2196 #define IS_CALL ((cmd->len & F_NOT) == 0) 2197 #define IS_RETURN ((cmd->len & F_NOT) != 0) 2198 /* 2199 * Hand-rolled version of m_tag_locate() with 2200 * wildcard `type'. 2201 * If not already tagged, allocate new tag. 2202 */ 2203 mtag = m_tag_first(m); 2204 while (mtag != NULL) { 2205 if (mtag->m_tag_cookie == 2206 MTAG_IPFW_CALL) 2207 break; 2208 mtag = m_tag_next(m, mtag); 2209 } 2210 if (mtag == NULL && IS_CALL) { 2211 mtag = m_tag_alloc(MTAG_IPFW_CALL, 0, 2212 IPFW_CALLSTACK_SIZE * 2213 sizeof(uint16_t), M_NOWAIT); 2214 if (mtag != NULL) 2215 m_tag_prepend(m, mtag); 2216 } 2217 2218 /* 2219 * On error both `call' and `return' just 2220 * continue with next rule. 2221 */ 2222 if (IS_RETURN && (mtag == NULL || 2223 mtag->m_tag_id == 0)) { 2224 l = 0; /* exit inner loop */ 2225 break; 2226 } 2227 if (IS_CALL && (mtag == NULL || 2228 mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) { 2229 printf("ipfw: call stack error, " 2230 "go to next rule\n"); 2231 l = 0; /* exit inner loop */ 2232 break; 2233 } 2234 2235 IPFW_INC_RULE_COUNTER(f, pktlen); 2236 stack = (uint16_t *)(mtag + 1); 2237 2238 /* 2239 * The `call' action may use cached f_pos 2240 * (in f->next_rule), whose version is written 2241 * in f->next_rule. 2242 * The `return' action, however, doesn't have 2243 * fixed jump address in cmd->arg1 and can't use 2244 * cache. 2245 */ 2246 if (IS_CALL) { 2247 stack[mtag->m_tag_id] = f->rulenum; 2248 mtag->m_tag_id++; 2249 f_pos = jump_fast(chain, f, cmd->arg1, 2250 tablearg, 1); 2251 } else { /* `return' action */ 2252 mtag->m_tag_id--; 2253 jmpto = stack[mtag->m_tag_id] + 1; 2254 f_pos = ipfw_find_rule(chain, jmpto, 0); 2255 } 2256 2257 /* 2258 * Skip disabled rules, and re-enter 2259 * the inner loop with the correct 2260 * f_pos, f, l and cmd. 2261 * Also clear cmdlen and skip_or 2262 */ 2263 for (; f_pos < chain->n_rules - 1 && 2264 (V_set_disable & 2265 (1 << chain->map[f_pos]->set)); f_pos++) 2266 ; 2267 /* Re-enter the inner loop at the dest rule. */ 2268 f = chain->map[f_pos]; 2269 l = f->cmd_len; 2270 cmd = f->cmd; 2271 cmdlen = 0; 2272 skip_or = 0; 2273 continue; 2274 break; /* NOTREACHED */ 2275 } 2276 #undef IS_CALL 2277 #undef IS_RETURN 2278 2279 case O_REJECT: 2280 /* 2281 * Drop the packet and send a reject notice 2282 * if the packet is not ICMP (or is an ICMP 2283 * query), and it is not multicast/broadcast. 2284 */ 2285 if (hlen > 0 && is_ipv4 && offset == 0 && 2286 (proto != IPPROTO_ICMP || 2287 is_icmp_query(ICMP(ulp))) && 2288 !(m->m_flags & (M_BCAST|M_MCAST)) && 2289 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 2290 send_reject(args, cmd->arg1, iplen, ip); 2291 m = args->m; 2292 } 2293 /* FALLTHROUGH */ 2294 #ifdef INET6 2295 case O_UNREACH6: 2296 if (hlen > 0 && is_ipv6 && 2297 ((offset & IP6F_OFF_MASK) == 0) && 2298 (proto != IPPROTO_ICMPV6 || 2299 (is_icmp6_query(icmp6_type) == 1)) && 2300 !(m->m_flags & (M_BCAST|M_MCAST)) && 2301 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 2302 send_reject6( 2303 args, cmd->arg1, hlen, 2304 (struct ip6_hdr *)ip); 2305 m = args->m; 2306 } 2307 /* FALLTHROUGH */ 2308 #endif 2309 case O_DENY: 2310 retval = IP_FW_DENY; 2311 l = 0; /* exit inner loop */ 2312 done = 1; /* exit outer loop */ 2313 break; 2314 2315 case O_FORWARD_IP: 2316 if (args->eh) /* not valid on layer2 pkts */ 2317 break; 2318 if (q == NULL || q->rule != f || 2319 dyn_dir == MATCH_FORWARD) { 2320 struct sockaddr_in *sa; 2321 sa = &(((ipfw_insn_sa *)cmd)->sa); 2322 if (sa->sin_addr.s_addr == INADDR_ANY) { 2323 bcopy(sa, &args->hopstore, 2324 sizeof(*sa)); 2325 args->hopstore.sin_addr.s_addr = 2326 htonl(tablearg); 2327 args->next_hop = &args->hopstore; 2328 } else { 2329 args->next_hop = sa; 2330 } 2331 } 2332 retval = IP_FW_PASS; 2333 l = 0; /* exit inner loop */ 2334 done = 1; /* exit outer loop */ 2335 break; 2336 2337 #ifdef INET6 2338 case O_FORWARD_IP6: 2339 if (args->eh) /* not valid on layer2 pkts */ 2340 break; 2341 if (q == NULL || q->rule != f || 2342 dyn_dir == MATCH_FORWARD) { 2343 struct sockaddr_in6 *sin6; 2344 2345 sin6 = &(((ipfw_insn_sa6 *)cmd)->sa); 2346 args->next_hop6 = sin6; 2347 } 2348 retval = IP_FW_PASS; 2349 l = 0; /* exit inner loop */ 2350 done = 1; /* exit outer loop */ 2351 break; 2352 #endif 2353 2354 case O_NETGRAPH: 2355 case O_NGTEE: 2356 set_match(args, f_pos, chain); 2357 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1); 2358 if (V_fw_one_pass) 2359 args->rule.info |= IPFW_ONEPASS; 2360 retval = (cmd->opcode == O_NETGRAPH) ? 2361 IP_FW_NETGRAPH : IP_FW_NGTEE; 2362 l = 0; /* exit inner loop */ 2363 done = 1; /* exit outer loop */ 2364 break; 2365 2366 case O_SETFIB: { 2367 uint32_t fib; 2368 2369 IPFW_INC_RULE_COUNTER(f, pktlen); 2370 fib = IP_FW_ARG_TABLEARG(cmd->arg1); 2371 if (fib >= rt_numfibs) 2372 fib = 0; 2373 M_SETFIB(m, fib); 2374 args->f_id.fib = fib; 2375 l = 0; /* exit inner loop */ 2376 break; 2377 } 2378 2379 case O_SETDSCP: { 2380 uint16_t code; 2381 2382 code = IP_FW_ARG_TABLEARG(cmd->arg1) & 0x3F; 2383 l = 0; /* exit inner loop */ 2384 if (is_ipv4) { 2385 uint16_t a; 2386 2387 a = ip->ip_tos; 2388 ip->ip_tos = (code << 2) | (ip->ip_tos & 0x03); 2389 a += ntohs(ip->ip_sum) - ip->ip_tos; 2390 ip->ip_sum = htons(a); 2391 } else if (is_ipv6) { 2392 uint8_t *v; 2393 2394 v = &((struct ip6_hdr *)ip)->ip6_vfc; 2395 *v = (*v & 0xF0) | (code >> 2); 2396 v++; 2397 *v = (*v & 0x3F) | ((code & 0x03) << 6); 2398 } else 2399 break; 2400 2401 IPFW_INC_RULE_COUNTER(f, pktlen); 2402 break; 2403 } 2404 2405 case O_NAT: 2406 if (!IPFW_NAT_LOADED) { 2407 retval = IP_FW_DENY; 2408 } else { 2409 struct cfg_nat *t; 2410 int nat_id; 2411 2412 set_match(args, f_pos, chain); 2413 /* Check if this is 'global' nat rule */ 2414 if (cmd->arg1 == 0) { 2415 retval = ipfw_nat_ptr(args, NULL, m); 2416 l = 0; 2417 done = 1; 2418 break; 2419 } 2420 t = ((ipfw_insn_nat *)cmd)->nat; 2421 if (t == NULL) { 2422 nat_id = IP_FW_ARG_TABLEARG(cmd->arg1); 2423 t = (*lookup_nat_ptr)(&chain->nat, nat_id); 2424 2425 if (t == NULL) { 2426 retval = IP_FW_DENY; 2427 l = 0; /* exit inner loop */ 2428 done = 1; /* exit outer loop */ 2429 break; 2430 } 2431 if (cmd->arg1 != IP_FW_TABLEARG) 2432 ((ipfw_insn_nat *)cmd)->nat = t; 2433 } 2434 retval = ipfw_nat_ptr(args, t, m); 2435 } 2436 l = 0; /* exit inner loop */ 2437 done = 1; /* exit outer loop */ 2438 break; 2439 2440 case O_REASS: { 2441 int ip_off; 2442 2443 IPFW_INC_RULE_COUNTER(f, pktlen); 2444 l = 0; /* in any case exit inner loop */ 2445 ip_off = ntohs(ip->ip_off); 2446 2447 /* if not fragmented, go to next rule */ 2448 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0) 2449 break; 2450 2451 args->m = m = ip_reass(m); 2452 2453 /* 2454 * do IP header checksum fixup. 2455 */ 2456 if (m == NULL) { /* fragment got swallowed */ 2457 retval = IP_FW_DENY; 2458 } else { /* good, packet complete */ 2459 int hlen; 2460 2461 ip = mtod(m, struct ip *); 2462 hlen = ip->ip_hl << 2; 2463 ip->ip_sum = 0; 2464 if (hlen == sizeof(struct ip)) 2465 ip->ip_sum = in_cksum_hdr(ip); 2466 else 2467 ip->ip_sum = in_cksum(m, hlen); 2468 retval = IP_FW_REASS; 2469 set_match(args, f_pos, chain); 2470 } 2471 done = 1; /* exit outer loop */ 2472 break; 2473 } 2474 2475 default: 2476 panic("-- unknown opcode %d\n", cmd->opcode); 2477 } /* end of switch() on opcodes */ 2478 /* 2479 * if we get here with l=0, then match is irrelevant. 2480 */ 2481 2482 if (cmd->len & F_NOT) 2483 match = !match; 2484 2485 if (match) { 2486 if (cmd->len & F_OR) 2487 skip_or = 1; 2488 } else { 2489 if (!(cmd->len & F_OR)) /* not an OR block, */ 2490 break; /* try next rule */ 2491 } 2492 2493 } /* end of inner loop, scan opcodes */ 2494 #undef PULLUP_LEN 2495 2496 if (done) 2497 break; 2498 2499 /* next_rule:; */ /* try next rule */ 2500 2501 } /* end of outer for, scan rules */ 2502 2503 if (done) { 2504 struct ip_fw *rule = chain->map[f_pos]; 2505 /* Update statistics */ 2506 IPFW_INC_RULE_COUNTER(rule, pktlen); 2507 } else { 2508 retval = IP_FW_DENY; 2509 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 2510 } 2511 IPFW_PF_RUNLOCK(chain); 2512 #ifdef __FreeBSD__ 2513 if (ucred_cache != NULL) 2514 crfree(ucred_cache); 2515 #endif 2516 return (retval); 2517 2518 pullup_failed: 2519 if (V_fw_verbose) 2520 printf("ipfw: pullup failed\n"); 2521 return (IP_FW_DENY); 2522 } 2523 2524 /* 2525 * Set maximum number of tables that can be used in given VNET ipfw instance. 2526 */ 2527 #ifdef SYSCTL_NODE 2528 static int 2529 sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS) 2530 { 2531 int error; 2532 unsigned int ntables; 2533 2534 ntables = V_fw_tables_max; 2535 2536 error = sysctl_handle_int(oidp, &ntables, 0, req); 2537 /* Read operation or some error */ 2538 if ((error != 0) || (req->newptr == NULL)) 2539 return (error); 2540 2541 return (ipfw_resize_tables(&V_layer3_chain, ntables)); 2542 } 2543 #endif 2544 /* 2545 * Module and VNET glue 2546 */ 2547 2548 /* 2549 * Stuff that must be initialised only on boot or module load 2550 */ 2551 static int 2552 ipfw_init(void) 2553 { 2554 int error = 0; 2555 2556 /* 2557 * Only print out this stuff the first time around, 2558 * when called from the sysinit code. 2559 */ 2560 printf("ipfw2 " 2561 #ifdef INET6 2562 "(+ipv6) " 2563 #endif 2564 "initialized, divert %s, nat %s, " 2565 "default to %s, logging ", 2566 #ifdef IPDIVERT 2567 "enabled", 2568 #else 2569 "loadable", 2570 #endif 2571 #ifdef IPFIREWALL_NAT 2572 "enabled", 2573 #else 2574 "loadable", 2575 #endif 2576 default_to_accept ? "accept" : "deny"); 2577 2578 /* 2579 * Note: V_xxx variables can be accessed here but the vnet specific 2580 * initializer may not have been called yet for the VIMAGE case. 2581 * Tuneables will have been processed. We will print out values for 2582 * the default vnet. 2583 * XXX This should all be rationalized AFTER 8.0 2584 */ 2585 if (V_fw_verbose == 0) 2586 printf("disabled\n"); 2587 else if (V_verbose_limit == 0) 2588 printf("unlimited\n"); 2589 else 2590 printf("limited to %d packets/entry by default\n", 2591 V_verbose_limit); 2592 2593 /* Check user-supplied table count for validness */ 2594 if (default_fw_tables > IPFW_TABLES_MAX) 2595 default_fw_tables = IPFW_TABLES_MAX; 2596 2597 ipfw_log_bpf(1); /* init */ 2598 return (error); 2599 } 2600 2601 /* 2602 * Called for the removal of the last instance only on module unload. 2603 */ 2604 static void 2605 ipfw_destroy(void) 2606 { 2607 2608 ipfw_log_bpf(0); /* uninit */ 2609 printf("IP firewall unloaded\n"); 2610 } 2611 2612 /* 2613 * Stuff that must be initialized for every instance 2614 * (including the first of course). 2615 */ 2616 static int 2617 vnet_ipfw_init(const void *unused) 2618 { 2619 int error; 2620 struct ip_fw *rule = NULL; 2621 struct ip_fw_chain *chain; 2622 2623 chain = &V_layer3_chain; 2624 2625 /* First set up some values that are compile time options */ 2626 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 2627 V_fw_deny_unknown_exthdrs = 1; 2628 #ifdef IPFIREWALL_VERBOSE 2629 V_fw_verbose = 1; 2630 #endif 2631 #ifdef IPFIREWALL_VERBOSE_LIMIT 2632 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 2633 #endif 2634 #ifdef IPFIREWALL_NAT 2635 LIST_INIT(&chain->nat); 2636 #endif 2637 2638 /* insert the default rule and create the initial map */ 2639 chain->n_rules = 1; 2640 chain->static_len = sizeof(struct ip_fw); 2641 chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_WAITOK | M_ZERO); 2642 if (chain->map) 2643 rule = malloc(chain->static_len, M_IPFW, M_WAITOK | M_ZERO); 2644 2645 /* Set initial number of tables */ 2646 V_fw_tables_max = default_fw_tables; 2647 error = ipfw_init_tables(chain); 2648 if (error) { 2649 printf("ipfw2: setting up tables failed\n"); 2650 free(chain->map, M_IPFW); 2651 free(rule, M_IPFW); 2652 return (ENOSPC); 2653 } 2654 2655 /* fill and insert the default rule */ 2656 rule->act_ofs = 0; 2657 rule->rulenum = IPFW_DEFAULT_RULE; 2658 rule->cmd_len = 1; 2659 rule->set = RESVD_SET; 2660 rule->cmd[0].len = 1; 2661 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY; 2662 chain->rules = chain->default_rule = chain->map[0] = rule; 2663 chain->id = rule->id = 1; 2664 2665 IPFW_LOCK_INIT(chain); 2666 ipfw_dyn_init(chain); 2667 2668 /* First set up some values that are compile time options */ 2669 V_ipfw_vnet_ready = 1; /* Open for business */ 2670 2671 /* 2672 * Hook the sockopt handler and pfil hooks for ipv4 and ipv6. 2673 * Even if the latter two fail we still keep the module alive 2674 * because the sockopt and layer2 paths are still useful. 2675 * ipfw[6]_hook return 0 on success, ENOENT on failure, 2676 * so we can ignore the exact return value and just set a flag. 2677 * 2678 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so 2679 * changes in the underlying (per-vnet) variables trigger 2680 * immediate hook()/unhook() calls. 2681 * In layer2 we have the same behaviour, except that V_ether_ipfw 2682 * is checked on each packet because there are no pfil hooks. 2683 */ 2684 V_ip_fw_ctl_ptr = ipfw_ctl; 2685 error = ipfw_attach_hooks(1); 2686 return (error); 2687 } 2688 2689 /* 2690 * Called for the removal of each instance. 2691 */ 2692 static int 2693 vnet_ipfw_uninit(const void *unused) 2694 { 2695 struct ip_fw *reap, *rule; 2696 struct ip_fw_chain *chain = &V_layer3_chain; 2697 int i; 2698 2699 V_ipfw_vnet_ready = 0; /* tell new callers to go away */ 2700 /* 2701 * disconnect from ipv4, ipv6, layer2 and sockopt. 2702 * Then grab, release and grab again the WLOCK so we make 2703 * sure the update is propagated and nobody will be in. 2704 */ 2705 (void)ipfw_attach_hooks(0 /* detach */); 2706 V_ip_fw_ctl_ptr = NULL; 2707 IPFW_UH_WLOCK(chain); 2708 IPFW_UH_WUNLOCK(chain); 2709 IPFW_UH_WLOCK(chain); 2710 2711 IPFW_WLOCK(chain); 2712 ipfw_dyn_uninit(0); /* run the callout_drain */ 2713 IPFW_WUNLOCK(chain); 2714 2715 ipfw_destroy_tables(chain); 2716 reap = NULL; 2717 IPFW_WLOCK(chain); 2718 for (i = 0; i < chain->n_rules; i++) { 2719 rule = chain->map[i]; 2720 rule->x_next = reap; 2721 reap = rule; 2722 } 2723 if (chain->map) 2724 free(chain->map, M_IPFW); 2725 IPFW_WUNLOCK(chain); 2726 IPFW_UH_WUNLOCK(chain); 2727 if (reap != NULL) 2728 ipfw_reap_rules(reap); 2729 IPFW_LOCK_DESTROY(chain); 2730 ipfw_dyn_uninit(1); /* free the remaining parts */ 2731 return 0; 2732 } 2733 2734 /* 2735 * Module event handler. 2736 * In general we have the choice of handling most of these events by the 2737 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to 2738 * use the SYSINIT handlers as they are more capable of expressing the 2739 * flow of control during module and vnet operations, so this is just 2740 * a skeleton. Note there is no SYSINIT equivalent of the module 2741 * SHUTDOWN handler, but we don't have anything to do in that case anyhow. 2742 */ 2743 static int 2744 ipfw_modevent(module_t mod, int type, void *unused) 2745 { 2746 int err = 0; 2747 2748 switch (type) { 2749 case MOD_LOAD: 2750 /* Called once at module load or 2751 * system boot if compiled in. */ 2752 break; 2753 case MOD_QUIESCE: 2754 /* Called before unload. May veto unloading. */ 2755 break; 2756 case MOD_UNLOAD: 2757 /* Called during unload. */ 2758 break; 2759 case MOD_SHUTDOWN: 2760 /* Called during system shutdown. */ 2761 break; 2762 default: 2763 err = EOPNOTSUPP; 2764 break; 2765 } 2766 return err; 2767 } 2768 2769 static moduledata_t ipfwmod = { 2770 "ipfw", 2771 ipfw_modevent, 2772 0 2773 }; 2774 2775 /* Define startup order. */ 2776 #define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_IFATTACHDOMAIN 2777 #define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */ 2778 #define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */ 2779 #define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */ 2780 2781 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER); 2782 MODULE_VERSION(ipfw, 2); 2783 /* should declare some dependencies here */ 2784 2785 /* 2786 * Starting up. Done in order after ipfwmod() has been called. 2787 * VNET_SYSINIT is also called for each existing vnet and each new vnet. 2788 */ 2789 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 2790 ipfw_init, NULL); 2791 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 2792 vnet_ipfw_init, NULL); 2793 2794 /* 2795 * Closing up shop. These are done in REVERSE ORDER, but still 2796 * after ipfwmod() has been called. Not called on reboot. 2797 * VNET_SYSUNINIT is also called for each exiting vnet as it exits. 2798 * or when the module is unloaded. 2799 */ 2800 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 2801 ipfw_destroy, NULL); 2802 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 2803 vnet_ipfw_uninit, NULL); 2804 /* end of file */ 2805