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/if_var.h> 63 #include <net/route.h> 64 #include <net/pfil.h> 65 #include <net/vnet.h> 66 67 #include <netpfil/pf/pf_mtag.h> 68 69 #include <netinet/in.h> 70 #include <netinet/in_var.h> 71 #include <netinet/in_pcb.h> 72 #include <netinet/ip.h> 73 #include <netinet/ip_var.h> 74 #include <netinet/ip_icmp.h> 75 #include <netinet/ip_fw.h> 76 #include <netinet/ip_carp.h> 77 #include <netinet/pim.h> 78 #include <netinet/tcp_var.h> 79 #include <netinet/udp.h> 80 #include <netinet/udp_var.h> 81 #include <netinet/sctp.h> 82 83 #include <netinet/ip6.h> 84 #include <netinet/icmp6.h> 85 #ifdef INET6 86 #include <netinet6/in6_pcb.h> 87 #include <netinet6/scope6_var.h> 88 #include <netinet6/ip6_var.h> 89 #endif 90 91 #include <netpfil/ipfw/ip_fw_private.h> 92 93 #include <machine/in_cksum.h> /* XXX for in_cksum */ 94 95 #ifdef MAC 96 #include <security/mac/mac_framework.h> 97 #endif 98 99 /* 100 * static variables followed by global ones. 101 * All ipfw global variables are here. 102 */ 103 104 /* ipfw_vnet_ready controls when we are open for business */ 105 static VNET_DEFINE(int, ipfw_vnet_ready) = 0; 106 #define V_ipfw_vnet_ready VNET(ipfw_vnet_ready) 107 108 static VNET_DEFINE(int, fw_deny_unknown_exthdrs); 109 #define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs) 110 111 static VNET_DEFINE(int, fw_permit_single_frag6) = 1; 112 #define V_fw_permit_single_frag6 VNET(fw_permit_single_frag6) 113 114 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 115 static int default_to_accept = 1; 116 #else 117 static int default_to_accept; 118 #endif 119 120 VNET_DEFINE(int, autoinc_step); 121 VNET_DEFINE(int, fw_one_pass) = 1; 122 123 VNET_DEFINE(unsigned int, fw_tables_max); 124 /* Use 128 tables by default */ 125 static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT; 126 127 /* 128 * Each rule belongs to one of 32 different sets (0..31). 129 * The variable set_disable contains one bit per set. 130 * If the bit is set, all rules in the corresponding set 131 * are disabled. Set RESVD_SET(31) is reserved for the default rule 132 * and rules that are not deleted by the flush command, 133 * and CANNOT be disabled. 134 * Rules in set RESVD_SET can only be deleted individually. 135 */ 136 VNET_DEFINE(u_int32_t, set_disable); 137 #define V_set_disable VNET(set_disable) 138 139 VNET_DEFINE(int, fw_verbose); 140 /* counter for ipfw_log(NULL...) */ 141 VNET_DEFINE(u_int64_t, norule_counter); 142 VNET_DEFINE(int, verbose_limit); 143 144 /* layer3_chain contains the list of rules for layer 3 */ 145 VNET_DEFINE(struct ip_fw_chain, layer3_chain); 146 147 VNET_DEFINE(int, ipfw_nat_ready) = 0; 148 149 ipfw_nat_t *ipfw_nat_ptr = NULL; 150 struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int); 151 ipfw_nat_cfg_t *ipfw_nat_cfg_ptr; 152 ipfw_nat_cfg_t *ipfw_nat_del_ptr; 153 ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr; 154 ipfw_nat_cfg_t *ipfw_nat_get_log_ptr; 155 156 #ifdef SYSCTL_NODE 157 uint32_t dummy_def = IPFW_DEFAULT_RULE; 158 static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS); 159 160 SYSBEGIN(f3) 161 162 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 163 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 164 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0, 165 "Only do a single pass through ipfw when using dummynet(4)"); 166 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, 167 CTLFLAG_RW, &VNET_NAME(autoinc_step), 0, 168 "Rule number auto-increment step"); 169 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose, 170 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0, 171 "Log matches to ipfw rules"); 172 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, 173 CTLFLAG_RW, &VNET_NAME(verbose_limit), 0, 174 "Set upper limit of matches of ipfw rules logged"); 175 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD, 176 &dummy_def, 0, 177 "The default/max possible rule number."); 178 SYSCTL_VNET_PROC(_net_inet_ip_fw, OID_AUTO, tables_max, 179 CTLTYPE_UINT|CTLFLAG_RW, 0, 0, sysctl_ipfw_table_num, "IU", 180 "Maximum number of tables"); 181 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN, 182 &default_to_accept, 0, 183 "Make the default rule accept all packets."); 184 TUNABLE_INT("net.inet.ip.fw.default_to_accept", &default_to_accept); 185 TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables); 186 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, static_count, 187 CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0, 188 "Number of static rules"); 189 190 #ifdef INET6 191 SYSCTL_DECL(_net_inet6_ip6); 192 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 193 SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs, 194 CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_deny_unknown_exthdrs), 0, 195 "Deny packets with unknown IPv6 Extension Headers"); 196 SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6, 197 CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_permit_single_frag6), 0, 198 "Permit single packet IPv6 fragments"); 199 #endif /* INET6 */ 200 201 SYSEND 202 203 #endif /* SYSCTL_NODE */ 204 205 206 /* 207 * Some macros used in the various matching options. 208 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 209 * Other macros just cast void * into the appropriate type 210 */ 211 #define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 212 #define TCP(p) ((struct tcphdr *)(p)) 213 #define SCTP(p) ((struct sctphdr *)(p)) 214 #define UDP(p) ((struct udphdr *)(p)) 215 #define ICMP(p) ((struct icmphdr *)(p)) 216 #define ICMP6(p) ((struct icmp6_hdr *)(p)) 217 218 static __inline int 219 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 220 { 221 int type = icmp->icmp_type; 222 223 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 224 } 225 226 #define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 227 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 228 229 static int 230 is_icmp_query(struct icmphdr *icmp) 231 { 232 int type = icmp->icmp_type; 233 234 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 235 } 236 #undef TT 237 238 /* 239 * The following checks use two arrays of 8 or 16 bits to store the 240 * bits that we want set or clear, respectively. They are in the 241 * low and high half of cmd->arg1 or cmd->d[0]. 242 * 243 * We scan options and store the bits we find set. We succeed if 244 * 245 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 246 * 247 * The code is sometimes optimized not to store additional variables. 248 */ 249 250 static int 251 flags_match(ipfw_insn *cmd, u_int8_t bits) 252 { 253 u_char want_clear; 254 bits = ~bits; 255 256 if ( ((cmd->arg1 & 0xff) & bits) != 0) 257 return 0; /* some bits we want set were clear */ 258 want_clear = (cmd->arg1 >> 8) & 0xff; 259 if ( (want_clear & bits) != want_clear) 260 return 0; /* some bits we want clear were set */ 261 return 1; 262 } 263 264 static int 265 ipopts_match(struct ip *ip, ipfw_insn *cmd) 266 { 267 int optlen, bits = 0; 268 u_char *cp = (u_char *)(ip + 1); 269 int x = (ip->ip_hl << 2) - sizeof (struct ip); 270 271 for (; x > 0; x -= optlen, cp += optlen) { 272 int opt = cp[IPOPT_OPTVAL]; 273 274 if (opt == IPOPT_EOL) 275 break; 276 if (opt == IPOPT_NOP) 277 optlen = 1; 278 else { 279 optlen = cp[IPOPT_OLEN]; 280 if (optlen <= 0 || optlen > x) 281 return 0; /* invalid or truncated */ 282 } 283 switch (opt) { 284 285 default: 286 break; 287 288 case IPOPT_LSRR: 289 bits |= IP_FW_IPOPT_LSRR; 290 break; 291 292 case IPOPT_SSRR: 293 bits |= IP_FW_IPOPT_SSRR; 294 break; 295 296 case IPOPT_RR: 297 bits |= IP_FW_IPOPT_RR; 298 break; 299 300 case IPOPT_TS: 301 bits |= IP_FW_IPOPT_TS; 302 break; 303 } 304 } 305 return (flags_match(cmd, bits)); 306 } 307 308 static int 309 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 310 { 311 int optlen, bits = 0; 312 u_char *cp = (u_char *)(tcp + 1); 313 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 314 315 for (; x > 0; x -= optlen, cp += optlen) { 316 int opt = cp[0]; 317 if (opt == TCPOPT_EOL) 318 break; 319 if (opt == TCPOPT_NOP) 320 optlen = 1; 321 else { 322 optlen = cp[1]; 323 if (optlen <= 0) 324 break; 325 } 326 327 switch (opt) { 328 329 default: 330 break; 331 332 case TCPOPT_MAXSEG: 333 bits |= IP_FW_TCPOPT_MSS; 334 break; 335 336 case TCPOPT_WINDOW: 337 bits |= IP_FW_TCPOPT_WINDOW; 338 break; 339 340 case TCPOPT_SACK_PERMITTED: 341 case TCPOPT_SACK: 342 bits |= IP_FW_TCPOPT_SACK; 343 break; 344 345 case TCPOPT_TIMESTAMP: 346 bits |= IP_FW_TCPOPT_TS; 347 break; 348 349 } 350 } 351 return (flags_match(cmd, bits)); 352 } 353 354 static int 355 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain, uint32_t *tablearg) 356 { 357 if (ifp == NULL) /* no iface with this packet, match fails */ 358 return 0; 359 /* Check by name or by IP address */ 360 if (cmd->name[0] != '\0') { /* match by name */ 361 if (cmd->name[0] == '\1') /* use tablearg to match */ 362 return ipfw_lookup_table_extended(chain, cmd->p.glob, 363 ifp->if_xname, tablearg, IPFW_TABLE_INTERFACE); 364 /* Check name */ 365 if (cmd->p.glob) { 366 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 367 return(1); 368 } else { 369 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 370 return(1); 371 } 372 } else { 373 #ifdef __FreeBSD__ /* and OSX too ? */ 374 struct ifaddr *ia; 375 376 if_addr_rlock(ifp); 377 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 378 if (ia->ifa_addr->sa_family != AF_INET) 379 continue; 380 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 381 (ia->ifa_addr))->sin_addr.s_addr) { 382 if_addr_runlock(ifp); 383 return(1); /* match */ 384 } 385 } 386 if_addr_runlock(ifp); 387 #endif /* __FreeBSD__ */ 388 } 389 return(0); /* no match, fail ... */ 390 } 391 392 /* 393 * The verify_path function checks if a route to the src exists and 394 * if it is reachable via ifp (when provided). 395 * 396 * The 'verrevpath' option checks that the interface that an IP packet 397 * arrives on is the same interface that traffic destined for the 398 * packet's source address would be routed out of. 399 * The 'versrcreach' option just checks that the source address is 400 * reachable via any route (except default) in the routing table. 401 * These two are a measure to block forged packets. This is also 402 * commonly known as "anti-spoofing" or Unicast Reverse Path 403 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 404 * is purposely reminiscent of the Cisco IOS command, 405 * 406 * ip verify unicast reverse-path 407 * ip verify unicast source reachable-via any 408 * 409 * which implements the same functionality. But note that the syntax 410 * is misleading, and the check may be performed on all IP packets 411 * whether unicast, multicast, or broadcast. 412 */ 413 static int 414 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib) 415 { 416 #ifndef __FreeBSD__ 417 return 0; 418 #else 419 struct route ro; 420 struct sockaddr_in *dst; 421 422 bzero(&ro, sizeof(ro)); 423 424 dst = (struct sockaddr_in *)&(ro.ro_dst); 425 dst->sin_family = AF_INET; 426 dst->sin_len = sizeof(*dst); 427 dst->sin_addr = src; 428 in_rtalloc_ign(&ro, 0, fib); 429 430 if (ro.ro_rt == NULL) 431 return 0; 432 433 /* 434 * If ifp is provided, check for equality with rtentry. 435 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 436 * in order to pass packets injected back by if_simloop(): 437 * if useloopback == 1 routing entry (via lo0) for our own address 438 * may exist, so we need to handle routing assymetry. 439 */ 440 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 441 RTFREE(ro.ro_rt); 442 return 0; 443 } 444 445 /* if no ifp provided, check if rtentry is not default route */ 446 if (ifp == NULL && 447 satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) { 448 RTFREE(ro.ro_rt); 449 return 0; 450 } 451 452 /* or if this is a blackhole/reject route */ 453 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 454 RTFREE(ro.ro_rt); 455 return 0; 456 } 457 458 /* found valid route */ 459 RTFREE(ro.ro_rt); 460 return 1; 461 #endif /* __FreeBSD__ */ 462 } 463 464 #ifdef INET6 465 /* 466 * ipv6 specific rules here... 467 */ 468 static __inline int 469 icmp6type_match (int type, ipfw_insn_u32 *cmd) 470 { 471 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 472 } 473 474 static int 475 flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 476 { 477 int i; 478 for (i=0; i <= cmd->o.arg1; ++i ) 479 if (curr_flow == cmd->d[i] ) 480 return 1; 481 return 0; 482 } 483 484 /* support for IP6_*_ME opcodes */ 485 static int 486 search_ip6_addr_net (struct in6_addr * ip6_addr) 487 { 488 struct ifnet *mdc; 489 struct ifaddr *mdc2; 490 struct in6_ifaddr *fdm; 491 struct in6_addr copia; 492 493 TAILQ_FOREACH(mdc, &V_ifnet, if_link) { 494 if_addr_rlock(mdc); 495 TAILQ_FOREACH(mdc2, &mdc->if_addrhead, ifa_link) { 496 if (mdc2->ifa_addr->sa_family == AF_INET6) { 497 fdm = (struct in6_ifaddr *)mdc2; 498 copia = fdm->ia_addr.sin6_addr; 499 /* need for leaving scope_id in the sock_addr */ 500 in6_clearscope(&copia); 501 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) { 502 if_addr_runlock(mdc); 503 return 1; 504 } 505 } 506 } 507 if_addr_runlock(mdc); 508 } 509 return 0; 510 } 511 512 static int 513 verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib) 514 { 515 struct route_in6 ro; 516 struct sockaddr_in6 *dst; 517 518 bzero(&ro, sizeof(ro)); 519 520 dst = (struct sockaddr_in6 * )&(ro.ro_dst); 521 dst->sin6_family = AF_INET6; 522 dst->sin6_len = sizeof(*dst); 523 dst->sin6_addr = *src; 524 525 in6_rtalloc_ign(&ro, 0, fib); 526 if (ro.ro_rt == NULL) 527 return 0; 528 529 /* 530 * if ifp is provided, check for equality with rtentry 531 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 532 * to support the case of sending packets to an address of our own. 533 * (where the former interface is the first argument of if_simloop() 534 * (=ifp), the latter is lo0) 535 */ 536 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 537 RTFREE(ro.ro_rt); 538 return 0; 539 } 540 541 /* if no ifp provided, check if rtentry is not default route */ 542 if (ifp == NULL && 543 IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) { 544 RTFREE(ro.ro_rt); 545 return 0; 546 } 547 548 /* or if this is a blackhole/reject route */ 549 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 550 RTFREE(ro.ro_rt); 551 return 0; 552 } 553 554 /* found valid route */ 555 RTFREE(ro.ro_rt); 556 return 1; 557 558 } 559 560 static int 561 is_icmp6_query(int icmp6_type) 562 { 563 if ((icmp6_type <= ICMP6_MAXTYPE) && 564 (icmp6_type == ICMP6_ECHO_REQUEST || 565 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 566 icmp6_type == ICMP6_WRUREQUEST || 567 icmp6_type == ICMP6_FQDN_QUERY || 568 icmp6_type == ICMP6_NI_QUERY)) 569 return (1); 570 571 return (0); 572 } 573 574 static void 575 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 576 { 577 struct mbuf *m; 578 579 m = args->m; 580 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 581 struct tcphdr *tcp; 582 tcp = (struct tcphdr *)((char *)ip6 + hlen); 583 584 if ((tcp->th_flags & TH_RST) == 0) { 585 struct mbuf *m0; 586 m0 = ipfw_send_pkt(args->m, &(args->f_id), 587 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 588 tcp->th_flags | TH_RST); 589 if (m0 != NULL) 590 ip6_output(m0, NULL, NULL, 0, NULL, NULL, 591 NULL); 592 } 593 FREE_PKT(m); 594 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */ 595 #if 0 596 /* 597 * Unlike above, the mbufs need to line up with the ip6 hdr, 598 * as the contents are read. We need to m_adj() the 599 * needed amount. 600 * The mbuf will however be thrown away so we can adjust it. 601 * Remember we did an m_pullup on it already so we 602 * can make some assumptions about contiguousness. 603 */ 604 if (args->L3offset) 605 m_adj(m, args->L3offset); 606 #endif 607 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 608 } else 609 FREE_PKT(m); 610 611 args->m = NULL; 612 } 613 614 #endif /* INET6 */ 615 616 617 /* 618 * sends a reject message, consuming the mbuf passed as an argument. 619 */ 620 static void 621 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip) 622 { 623 624 #if 0 625 /* XXX When ip is not guaranteed to be at mtod() we will 626 * need to account for this */ 627 * The mbuf will however be thrown away so we can adjust it. 628 * Remember we did an m_pullup on it already so we 629 * can make some assumptions about contiguousness. 630 */ 631 if (args->L3offset) 632 m_adj(m, args->L3offset); 633 #endif 634 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */ 635 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 636 } else if (args->f_id.proto == IPPROTO_TCP) { 637 struct tcphdr *const tcp = 638 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 639 if ( (tcp->th_flags & TH_RST) == 0) { 640 struct mbuf *m; 641 m = ipfw_send_pkt(args->m, &(args->f_id), 642 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 643 tcp->th_flags | TH_RST); 644 if (m != NULL) 645 ip_output(m, NULL, NULL, 0, NULL, NULL); 646 } 647 FREE_PKT(args->m); 648 } else 649 FREE_PKT(args->m); 650 args->m = NULL; 651 } 652 653 /* 654 * Support for uid/gid/jail lookup. These tests are expensive 655 * (because we may need to look into the list of active sockets) 656 * so we cache the results. ugid_lookupp is 0 if we have not 657 * yet done a lookup, 1 if we succeeded, and -1 if we tried 658 * and failed. The function always returns the match value. 659 * We could actually spare the variable and use *uc, setting 660 * it to '(void *)check_uidgid if we have no info, NULL if 661 * we tried and failed, or any other value if successful. 662 */ 663 static int 664 check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp, 665 struct ucred **uc) 666 { 667 #ifndef __FreeBSD__ 668 /* XXX */ 669 return cred_check(insn, proto, oif, 670 dst_ip, dst_port, src_ip, src_port, 671 (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb); 672 #else /* FreeBSD */ 673 struct in_addr src_ip, dst_ip; 674 struct inpcbinfo *pi; 675 struct ipfw_flow_id *id; 676 struct inpcb *pcb, *inp; 677 struct ifnet *oif; 678 int lookupflags; 679 int match; 680 681 id = &args->f_id; 682 inp = args->inp; 683 oif = args->oif; 684 685 /* 686 * Check to see if the UDP or TCP stack supplied us with 687 * the PCB. If so, rather then holding a lock and looking 688 * up the PCB, we can use the one that was supplied. 689 */ 690 if (inp && *ugid_lookupp == 0) { 691 INP_LOCK_ASSERT(inp); 692 if (inp->inp_socket != NULL) { 693 *uc = crhold(inp->inp_cred); 694 *ugid_lookupp = 1; 695 } else 696 *ugid_lookupp = -1; 697 } 698 /* 699 * If we have already been here and the packet has no 700 * PCB entry associated with it, then we can safely 701 * assume that this is a no match. 702 */ 703 if (*ugid_lookupp == -1) 704 return (0); 705 if (id->proto == IPPROTO_TCP) { 706 lookupflags = 0; 707 pi = &V_tcbinfo; 708 } else if (id->proto == IPPROTO_UDP) { 709 lookupflags = INPLOOKUP_WILDCARD; 710 pi = &V_udbinfo; 711 } else 712 return 0; 713 lookupflags |= INPLOOKUP_RLOCKPCB; 714 match = 0; 715 if (*ugid_lookupp == 0) { 716 if (id->addr_type == 6) { 717 #ifdef INET6 718 if (oif == NULL) 719 pcb = in6_pcblookup_mbuf(pi, 720 &id->src_ip6, htons(id->src_port), 721 &id->dst_ip6, htons(id->dst_port), 722 lookupflags, oif, args->m); 723 else 724 pcb = in6_pcblookup_mbuf(pi, 725 &id->dst_ip6, htons(id->dst_port), 726 &id->src_ip6, htons(id->src_port), 727 lookupflags, oif, args->m); 728 #else 729 *ugid_lookupp = -1; 730 return (0); 731 #endif 732 } else { 733 src_ip.s_addr = htonl(id->src_ip); 734 dst_ip.s_addr = htonl(id->dst_ip); 735 if (oif == NULL) 736 pcb = in_pcblookup_mbuf(pi, 737 src_ip, htons(id->src_port), 738 dst_ip, htons(id->dst_port), 739 lookupflags, oif, args->m); 740 else 741 pcb = in_pcblookup_mbuf(pi, 742 dst_ip, htons(id->dst_port), 743 src_ip, htons(id->src_port), 744 lookupflags, oif, args->m); 745 } 746 if (pcb != NULL) { 747 INP_RLOCK_ASSERT(pcb); 748 *uc = crhold(pcb->inp_cred); 749 *ugid_lookupp = 1; 750 INP_RUNLOCK(pcb); 751 } 752 if (*ugid_lookupp == 0) { 753 /* 754 * We tried and failed, set the variable to -1 755 * so we will not try again on this packet. 756 */ 757 *ugid_lookupp = -1; 758 return (0); 759 } 760 } 761 if (insn->o.opcode == O_UID) 762 match = ((*uc)->cr_uid == (uid_t)insn->d[0]); 763 else if (insn->o.opcode == O_GID) 764 match = groupmember((gid_t)insn->d[0], *uc); 765 else if (insn->o.opcode == O_JAIL) 766 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]); 767 return (match); 768 #endif /* __FreeBSD__ */ 769 } 770 771 /* 772 * Helper function to set args with info on the rule after the matching 773 * one. slot is precise, whereas we guess rule_id as they are 774 * assigned sequentially. 775 */ 776 static inline void 777 set_match(struct ip_fw_args *args, int slot, 778 struct ip_fw_chain *chain) 779 { 780 args->rule.chain_id = chain->id; 781 args->rule.slot = slot + 1; /* we use 0 as a marker */ 782 args->rule.rule_id = 1 + chain->map[slot]->id; 783 args->rule.rulenum = chain->map[slot]->rulenum; 784 } 785 786 /* 787 * Helper function to enable cached rule lookups using 788 * x_next and next_rule fields in ipfw rule. 789 */ 790 static int 791 jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 792 int tablearg, int jump_backwards) 793 { 794 int f_pos; 795 796 /* If possible use cached f_pos (in f->next_rule), 797 * whose version is written in f->next_rule 798 * (horrible hacks to avoid changing the ABI). 799 */ 800 if (num != IP_FW_TABLEARG && (uintptr_t)f->x_next == chain->id) 801 f_pos = (uintptr_t)f->next_rule; 802 else { 803 int i = IP_FW_ARG_TABLEARG(num); 804 /* make sure we do not jump backward */ 805 if (jump_backwards == 0 && i <= f->rulenum) 806 i = f->rulenum + 1; 807 f_pos = ipfw_find_rule(chain, i, 0); 808 /* update the cache */ 809 if (num != IP_FW_TABLEARG) { 810 f->next_rule = (void *)(uintptr_t)f_pos; 811 f->x_next = (void *)(uintptr_t)chain->id; 812 } 813 } 814 815 return (f_pos); 816 } 817 818 /* 819 * The main check routine for the firewall. 820 * 821 * All arguments are in args so we can modify them and return them 822 * back to the caller. 823 * 824 * Parameters: 825 * 826 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 827 * Starts with the IP header. 828 * args->eh (in) Mac header if present, NULL for layer3 packet. 829 * args->L3offset Number of bytes bypassed if we came from L2. 830 * e.g. often sizeof(eh) ** NOTYET ** 831 * args->oif Outgoing interface, NULL if packet is incoming. 832 * The incoming interface is in the mbuf. (in) 833 * args->divert_rule (in/out) 834 * Skip up to the first rule past this rule number; 835 * upon return, non-zero port number for divert or tee. 836 * 837 * args->rule Pointer to the last matching rule (in/out) 838 * args->next_hop Socket we are forwarding to (out). 839 * args->next_hop6 IPv6 next hop we are forwarding to (out). 840 * args->f_id Addresses grabbed from the packet (out) 841 * args->rule.info a cookie depending on rule action 842 * 843 * Return value: 844 * 845 * IP_FW_PASS the packet must be accepted 846 * IP_FW_DENY the packet must be dropped 847 * IP_FW_DIVERT divert packet, port in m_tag 848 * IP_FW_TEE tee packet, port in m_tag 849 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 850 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 851 * args->rule contains the matching rule, 852 * args->rule.info has additional information. 853 * 854 */ 855 int 856 ipfw_chk(struct ip_fw_args *args) 857 { 858 859 /* 860 * Local variables holding state while processing a packet: 861 * 862 * IMPORTANT NOTE: to speed up the processing of rules, there 863 * are some assumption on the values of the variables, which 864 * are documented here. Should you change them, please check 865 * the implementation of the various instructions to make sure 866 * that they still work. 867 * 868 * args->eh The MAC header. It is non-null for a layer2 869 * packet, it is NULL for a layer-3 packet. 870 * **notyet** 871 * args->L3offset Offset in the packet to the L3 (IP or equiv.) header. 872 * 873 * m | args->m Pointer to the mbuf, as received from the caller. 874 * It may change if ipfw_chk() does an m_pullup, or if it 875 * consumes the packet because it calls send_reject(). 876 * XXX This has to change, so that ipfw_chk() never modifies 877 * or consumes the buffer. 878 * ip is the beginning of the ip(4 or 6) header. 879 * Calculated by adding the L3offset to the start of data. 880 * (Until we start using L3offset, the packet is 881 * supposed to start with the ip header). 882 */ 883 struct mbuf *m = args->m; 884 struct ip *ip = mtod(m, struct ip *); 885 886 /* 887 * For rules which contain uid/gid or jail constraints, cache 888 * a copy of the users credentials after the pcb lookup has been 889 * executed. This will speed up the processing of rules with 890 * these types of constraints, as well as decrease contention 891 * on pcb related locks. 892 */ 893 #ifndef __FreeBSD__ 894 struct bsd_ucred ucred_cache; 895 #else 896 struct ucred *ucred_cache = NULL; 897 #endif 898 int ucred_lookup = 0; 899 900 /* 901 * oif | args->oif If NULL, ipfw_chk has been called on the 902 * inbound path (ether_input, ip_input). 903 * If non-NULL, ipfw_chk has been called on the outbound path 904 * (ether_output, ip_output). 905 */ 906 struct ifnet *oif = args->oif; 907 908 int f_pos = 0; /* index of current rule in the array */ 909 int retval = 0; 910 911 /* 912 * hlen The length of the IP header. 913 */ 914 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 915 916 /* 917 * offset The offset of a fragment. offset != 0 means that 918 * we have a fragment at this offset of an IPv4 packet. 919 * offset == 0 means that (if this is an IPv4 packet) 920 * this is the first or only fragment. 921 * For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header 922 * or there is a single packet fragement (fragement header added 923 * without needed). We will treat a single packet fragment as if 924 * there was no fragment header (or log/block depending on the 925 * V_fw_permit_single_frag6 sysctl setting). 926 */ 927 u_short offset = 0; 928 u_short ip6f_mf = 0; 929 930 /* 931 * Local copies of addresses. They are only valid if we have 932 * an IP packet. 933 * 934 * proto The protocol. Set to 0 for non-ip packets, 935 * or to the protocol read from the packet otherwise. 936 * proto != 0 means that we have an IPv4 packet. 937 * 938 * src_port, dst_port port numbers, in HOST format. Only 939 * valid for TCP and UDP packets. 940 * 941 * src_ip, dst_ip ip addresses, in NETWORK format. 942 * Only valid for IPv4 packets. 943 */ 944 uint8_t proto; 945 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 946 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 947 uint16_t iplen=0; 948 int pktlen; 949 uint16_t etype = 0; /* Host order stored ether type */ 950 951 /* 952 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 953 * MATCH_NONE when checked and not matched (q = NULL), 954 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) 955 */ 956 int dyn_dir = MATCH_UNKNOWN; 957 ipfw_dyn_rule *q = NULL; 958 struct ip_fw_chain *chain = &V_layer3_chain; 959 960 /* 961 * We store in ulp a pointer to the upper layer protocol header. 962 * In the ipv4 case this is easy to determine from the header, 963 * but for ipv6 we might have some additional headers in the middle. 964 * ulp is NULL if not found. 965 */ 966 void *ulp = NULL; /* upper layer protocol pointer. */ 967 968 /* XXX ipv6 variables */ 969 int is_ipv6 = 0; 970 uint8_t icmp6_type = 0; 971 uint16_t ext_hd = 0; /* bits vector for extension header filtering */ 972 /* end of ipv6 variables */ 973 974 int is_ipv4 = 0; 975 976 int done = 0; /* flag to exit the outer loop */ 977 978 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready)) 979 return (IP_FW_PASS); /* accept */ 980 981 dst_ip.s_addr = 0; /* make sure it is initialized */ 982 src_ip.s_addr = 0; /* make sure it is initialized */ 983 pktlen = m->m_pkthdr.len; 984 args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */ 985 proto = args->f_id.proto = 0; /* mark f_id invalid */ 986 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ 987 988 /* 989 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 990 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 991 * pointer might become stale after other pullups (but we never use it 992 * this way). 993 */ 994 #define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T)) 995 #define PULLUP_LEN(_len, p, T) \ 996 do { \ 997 int x = (_len) + T; \ 998 if ((m)->m_len < x) { \ 999 args->m = m = m_pullup(m, x); \ 1000 if (m == NULL) \ 1001 goto pullup_failed; \ 1002 } \ 1003 p = (mtod(m, char *) + (_len)); \ 1004 } while (0) 1005 1006 /* 1007 * if we have an ether header, 1008 */ 1009 if (args->eh) 1010 etype = ntohs(args->eh->ether_type); 1011 1012 /* Identify IP packets and fill up variables. */ 1013 if (pktlen >= sizeof(struct ip6_hdr) && 1014 (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) { 1015 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 1016 is_ipv6 = 1; 1017 args->f_id.addr_type = 6; 1018 hlen = sizeof(struct ip6_hdr); 1019 proto = ip6->ip6_nxt; 1020 1021 /* Search extension headers to find upper layer protocols */ 1022 while (ulp == NULL && offset == 0) { 1023 switch (proto) { 1024 case IPPROTO_ICMPV6: 1025 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 1026 icmp6_type = ICMP6(ulp)->icmp6_type; 1027 break; 1028 1029 case IPPROTO_TCP: 1030 PULLUP_TO(hlen, ulp, struct tcphdr); 1031 dst_port = TCP(ulp)->th_dport; 1032 src_port = TCP(ulp)->th_sport; 1033 /* save flags for dynamic rules */ 1034 args->f_id._flags = TCP(ulp)->th_flags; 1035 break; 1036 1037 case IPPROTO_SCTP: 1038 PULLUP_TO(hlen, ulp, struct sctphdr); 1039 src_port = SCTP(ulp)->src_port; 1040 dst_port = SCTP(ulp)->dest_port; 1041 break; 1042 1043 case IPPROTO_UDP: 1044 PULLUP_TO(hlen, ulp, struct udphdr); 1045 dst_port = UDP(ulp)->uh_dport; 1046 src_port = UDP(ulp)->uh_sport; 1047 break; 1048 1049 case IPPROTO_HOPOPTS: /* RFC 2460 */ 1050 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1051 ext_hd |= EXT_HOPOPTS; 1052 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1053 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1054 ulp = NULL; 1055 break; 1056 1057 case IPPROTO_ROUTING: /* RFC 2460 */ 1058 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 1059 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 1060 case 0: 1061 ext_hd |= EXT_RTHDR0; 1062 break; 1063 case 2: 1064 ext_hd |= EXT_RTHDR2; 1065 break; 1066 default: 1067 if (V_fw_verbose) 1068 printf("IPFW2: IPV6 - Unknown " 1069 "Routing Header type(%d)\n", 1070 ((struct ip6_rthdr *) 1071 ulp)->ip6r_type); 1072 if (V_fw_deny_unknown_exthdrs) 1073 return (IP_FW_DENY); 1074 break; 1075 } 1076 ext_hd |= EXT_ROUTING; 1077 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 1078 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 1079 ulp = NULL; 1080 break; 1081 1082 case IPPROTO_FRAGMENT: /* RFC 2460 */ 1083 PULLUP_TO(hlen, ulp, struct ip6_frag); 1084 ext_hd |= EXT_FRAGMENT; 1085 hlen += sizeof (struct ip6_frag); 1086 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 1087 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 1088 IP6F_OFF_MASK; 1089 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg & 1090 IP6F_MORE_FRAG; 1091 if (V_fw_permit_single_frag6 == 0 && 1092 offset == 0 && ip6f_mf == 0) { 1093 if (V_fw_verbose) 1094 printf("IPFW2: IPV6 - Invalid " 1095 "Fragment Header\n"); 1096 if (V_fw_deny_unknown_exthdrs) 1097 return (IP_FW_DENY); 1098 break; 1099 } 1100 args->f_id.extra = 1101 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 1102 ulp = NULL; 1103 break; 1104 1105 case IPPROTO_DSTOPTS: /* RFC 2460 */ 1106 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1107 ext_hd |= EXT_DSTOPTS; 1108 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1109 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1110 ulp = NULL; 1111 break; 1112 1113 case IPPROTO_AH: /* RFC 2402 */ 1114 PULLUP_TO(hlen, ulp, struct ip6_ext); 1115 ext_hd |= EXT_AH; 1116 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 1117 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 1118 ulp = NULL; 1119 break; 1120 1121 case IPPROTO_ESP: /* RFC 2406 */ 1122 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 1123 /* Anything past Seq# is variable length and 1124 * data past this ext. header is encrypted. */ 1125 ext_hd |= EXT_ESP; 1126 break; 1127 1128 case IPPROTO_NONE: /* RFC 2460 */ 1129 /* 1130 * Packet ends here, and IPv6 header has 1131 * already been pulled up. If ip6e_len!=0 1132 * then octets must be ignored. 1133 */ 1134 ulp = ip; /* non-NULL to get out of loop. */ 1135 break; 1136 1137 case IPPROTO_OSPFIGP: 1138 /* XXX OSPF header check? */ 1139 PULLUP_TO(hlen, ulp, struct ip6_ext); 1140 break; 1141 1142 case IPPROTO_PIM: 1143 /* XXX PIM header check? */ 1144 PULLUP_TO(hlen, ulp, struct pim); 1145 break; 1146 1147 case IPPROTO_CARP: 1148 PULLUP_TO(hlen, ulp, struct carp_header); 1149 if (((struct carp_header *)ulp)->carp_version != 1150 CARP_VERSION) 1151 return (IP_FW_DENY); 1152 if (((struct carp_header *)ulp)->carp_type != 1153 CARP_ADVERTISEMENT) 1154 return (IP_FW_DENY); 1155 break; 1156 1157 case IPPROTO_IPV6: /* RFC 2893 */ 1158 PULLUP_TO(hlen, ulp, struct ip6_hdr); 1159 break; 1160 1161 case IPPROTO_IPV4: /* RFC 2893 */ 1162 PULLUP_TO(hlen, ulp, struct ip); 1163 break; 1164 1165 default: 1166 if (V_fw_verbose) 1167 printf("IPFW2: IPV6 - Unknown " 1168 "Extension Header(%d), ext_hd=%x\n", 1169 proto, ext_hd); 1170 if (V_fw_deny_unknown_exthdrs) 1171 return (IP_FW_DENY); 1172 PULLUP_TO(hlen, ulp, struct ip6_ext); 1173 break; 1174 } /*switch */ 1175 } 1176 ip = mtod(m, struct ip *); 1177 ip6 = (struct ip6_hdr *)ip; 1178 args->f_id.src_ip6 = ip6->ip6_src; 1179 args->f_id.dst_ip6 = ip6->ip6_dst; 1180 args->f_id.src_ip = 0; 1181 args->f_id.dst_ip = 0; 1182 args->f_id.flow_id6 = ntohl(ip6->ip6_flow); 1183 } else if (pktlen >= sizeof(struct ip) && 1184 (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) { 1185 is_ipv4 = 1; 1186 hlen = ip->ip_hl << 2; 1187 args->f_id.addr_type = 4; 1188 1189 /* 1190 * Collect parameters into local variables for faster matching. 1191 */ 1192 proto = ip->ip_p; 1193 src_ip = ip->ip_src; 1194 dst_ip = ip->ip_dst; 1195 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1196 iplen = ntohs(ip->ip_len); 1197 pktlen = iplen < pktlen ? iplen : pktlen; 1198 1199 if (offset == 0) { 1200 switch (proto) { 1201 case IPPROTO_TCP: 1202 PULLUP_TO(hlen, ulp, struct tcphdr); 1203 dst_port = TCP(ulp)->th_dport; 1204 src_port = TCP(ulp)->th_sport; 1205 /* save flags for dynamic rules */ 1206 args->f_id._flags = TCP(ulp)->th_flags; 1207 break; 1208 1209 case IPPROTO_SCTP: 1210 PULLUP_TO(hlen, ulp, struct sctphdr); 1211 src_port = SCTP(ulp)->src_port; 1212 dst_port = SCTP(ulp)->dest_port; 1213 break; 1214 1215 case IPPROTO_UDP: 1216 PULLUP_TO(hlen, ulp, struct udphdr); 1217 dst_port = UDP(ulp)->uh_dport; 1218 src_port = UDP(ulp)->uh_sport; 1219 break; 1220 1221 case IPPROTO_ICMP: 1222 PULLUP_TO(hlen, ulp, struct icmphdr); 1223 //args->f_id.flags = ICMP(ulp)->icmp_type; 1224 break; 1225 1226 default: 1227 break; 1228 } 1229 } 1230 1231 ip = mtod(m, struct ip *); 1232 args->f_id.src_ip = ntohl(src_ip.s_addr); 1233 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1234 } 1235 #undef PULLUP_TO 1236 if (proto) { /* we may have port numbers, store them */ 1237 args->f_id.proto = proto; 1238 args->f_id.src_port = src_port = ntohs(src_port); 1239 args->f_id.dst_port = dst_port = ntohs(dst_port); 1240 } 1241 1242 IPFW_PF_RLOCK(chain); 1243 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ 1244 IPFW_PF_RUNLOCK(chain); 1245 return (IP_FW_PASS); /* accept */ 1246 } 1247 if (args->rule.slot) { 1248 /* 1249 * Packet has already been tagged as a result of a previous 1250 * match on rule args->rule aka args->rule_id (PIPE, QUEUE, 1251 * REASS, NETGRAPH, DIVERT/TEE...) 1252 * Validate the slot and continue from the next one 1253 * if still present, otherwise do a lookup. 1254 */ 1255 f_pos = (args->rule.chain_id == chain->id) ? 1256 args->rule.slot : 1257 ipfw_find_rule(chain, args->rule.rulenum, 1258 args->rule.rule_id); 1259 } else { 1260 f_pos = 0; 1261 } 1262 1263 /* 1264 * Now scan the rules, and parse microinstructions for each rule. 1265 * We have two nested loops and an inner switch. Sometimes we 1266 * need to break out of one or both loops, or re-enter one of 1267 * the loops with updated variables. Loop variables are: 1268 * 1269 * f_pos (outer loop) points to the current rule. 1270 * On output it points to the matching rule. 1271 * done (outer loop) is used as a flag to break the loop. 1272 * l (inner loop) residual length of current rule. 1273 * cmd points to the current microinstruction. 1274 * 1275 * We break the inner loop by setting l=0 and possibly 1276 * cmdlen=0 if we don't want to advance cmd. 1277 * We break the outer loop by setting done=1 1278 * We can restart the inner loop by setting l>0 and f_pos, f, cmd 1279 * as needed. 1280 */ 1281 for (; f_pos < chain->n_rules; f_pos++) { 1282 ipfw_insn *cmd; 1283 uint32_t tablearg = 0; 1284 int l, cmdlen, skip_or; /* skip rest of OR block */ 1285 struct ip_fw *f; 1286 1287 f = chain->map[f_pos]; 1288 if (V_set_disable & (1 << f->set) ) 1289 continue; 1290 1291 skip_or = 0; 1292 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 1293 l -= cmdlen, cmd += cmdlen) { 1294 int match; 1295 1296 /* 1297 * check_body is a jump target used when we find a 1298 * CHECK_STATE, and need to jump to the body of 1299 * the target rule. 1300 */ 1301 1302 /* check_body: */ 1303 cmdlen = F_LEN(cmd); 1304 /* 1305 * An OR block (insn_1 || .. || insn_n) has the 1306 * F_OR bit set in all but the last instruction. 1307 * The first match will set "skip_or", and cause 1308 * the following instructions to be skipped until 1309 * past the one with the F_OR bit clear. 1310 */ 1311 if (skip_or) { /* skip this instruction */ 1312 if ((cmd->len & F_OR) == 0) 1313 skip_or = 0; /* next one is good */ 1314 continue; 1315 } 1316 match = 0; /* set to 1 if we succeed */ 1317 1318 switch (cmd->opcode) { 1319 /* 1320 * The first set of opcodes compares the packet's 1321 * fields with some pattern, setting 'match' if a 1322 * match is found. At the end of the loop there is 1323 * logic to deal with F_NOT and F_OR flags associated 1324 * with the opcode. 1325 */ 1326 case O_NOP: 1327 match = 1; 1328 break; 1329 1330 case O_FORWARD_MAC: 1331 printf("ipfw: opcode %d unimplemented\n", 1332 cmd->opcode); 1333 break; 1334 1335 case O_GID: 1336 case O_UID: 1337 case O_JAIL: 1338 /* 1339 * We only check offset == 0 && proto != 0, 1340 * as this ensures that we have a 1341 * packet with the ports info. 1342 */ 1343 if (offset != 0) 1344 break; 1345 if (proto == IPPROTO_TCP || 1346 proto == IPPROTO_UDP) 1347 match = check_uidgid( 1348 (ipfw_insn_u32 *)cmd, 1349 args, &ucred_lookup, 1350 #ifdef __FreeBSD__ 1351 &ucred_cache); 1352 #else 1353 (void *)&ucred_cache); 1354 #endif 1355 break; 1356 1357 case O_RECV: 1358 match = iface_match(m->m_pkthdr.rcvif, 1359 (ipfw_insn_if *)cmd, chain, &tablearg); 1360 break; 1361 1362 case O_XMIT: 1363 match = iface_match(oif, (ipfw_insn_if *)cmd, 1364 chain, &tablearg); 1365 break; 1366 1367 case O_VIA: 1368 match = iface_match(oif ? oif : 1369 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd, 1370 chain, &tablearg); 1371 break; 1372 1373 case O_MACADDR2: 1374 if (args->eh != NULL) { /* have MAC header */ 1375 u_int32_t *want = (u_int32_t *) 1376 ((ipfw_insn_mac *)cmd)->addr; 1377 u_int32_t *mask = (u_int32_t *) 1378 ((ipfw_insn_mac *)cmd)->mask; 1379 u_int32_t *hdr = (u_int32_t *)args->eh; 1380 1381 match = 1382 ( want[0] == (hdr[0] & mask[0]) && 1383 want[1] == (hdr[1] & mask[1]) && 1384 want[2] == (hdr[2] & mask[2]) ); 1385 } 1386 break; 1387 1388 case O_MAC_TYPE: 1389 if (args->eh != NULL) { 1390 u_int16_t *p = 1391 ((ipfw_insn_u16 *)cmd)->ports; 1392 int i; 1393 1394 for (i = cmdlen - 1; !match && i>0; 1395 i--, p += 2) 1396 match = (etype >= p[0] && 1397 etype <= p[1]); 1398 } 1399 break; 1400 1401 case O_FRAG: 1402 match = (offset != 0); 1403 break; 1404 1405 case O_IN: /* "out" is "not in" */ 1406 match = (oif == NULL); 1407 break; 1408 1409 case O_LAYER2: 1410 match = (args->eh != NULL); 1411 break; 1412 1413 case O_DIVERTED: 1414 { 1415 /* For diverted packets, args->rule.info 1416 * contains the divert port (in host format) 1417 * reason and direction. 1418 */ 1419 uint32_t i = args->rule.info; 1420 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT && 1421 cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2); 1422 } 1423 break; 1424 1425 case O_PROTO: 1426 /* 1427 * We do not allow an arg of 0 so the 1428 * check of "proto" only suffices. 1429 */ 1430 match = (proto == cmd->arg1); 1431 break; 1432 1433 case O_IP_SRC: 1434 match = is_ipv4 && 1435 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1436 src_ip.s_addr); 1437 break; 1438 1439 case O_IP_SRC_LOOKUP: 1440 case O_IP_DST_LOOKUP: 1441 if (is_ipv4) { 1442 uint32_t key = 1443 (cmd->opcode == O_IP_DST_LOOKUP) ? 1444 dst_ip.s_addr : src_ip.s_addr; 1445 uint32_t v = 0; 1446 1447 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { 1448 /* generic lookup. The key must be 1449 * in 32bit big-endian format. 1450 */ 1451 v = ((ipfw_insn_u32 *)cmd)->d[1]; 1452 if (v == 0) 1453 key = dst_ip.s_addr; 1454 else if (v == 1) 1455 key = src_ip.s_addr; 1456 else if (v == 6) /* dscp */ 1457 key = (ip->ip_tos >> 2) & 0x3f; 1458 else if (offset != 0) 1459 break; 1460 else if (proto != IPPROTO_TCP && 1461 proto != IPPROTO_UDP) 1462 break; 1463 else if (v == 2) 1464 key = htonl(dst_port); 1465 else if (v == 3) 1466 key = htonl(src_port); 1467 else if (v == 4 || v == 5) { 1468 check_uidgid( 1469 (ipfw_insn_u32 *)cmd, 1470 args, &ucred_lookup, 1471 #ifdef __FreeBSD__ 1472 &ucred_cache); 1473 if (v == 4 /* O_UID */) 1474 key = ucred_cache->cr_uid; 1475 else if (v == 5 /* O_JAIL */) 1476 key = ucred_cache->cr_prison->pr_id; 1477 #else /* !__FreeBSD__ */ 1478 (void *)&ucred_cache); 1479 if (v ==4 /* O_UID */) 1480 key = ucred_cache.uid; 1481 else if (v == 5 /* O_JAIL */) 1482 key = ucred_cache.xid; 1483 #endif /* !__FreeBSD__ */ 1484 key = htonl(key); 1485 } else 1486 break; 1487 } 1488 match = ipfw_lookup_table(chain, 1489 cmd->arg1, key, &v); 1490 if (!match) 1491 break; 1492 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1493 match = 1494 ((ipfw_insn_u32 *)cmd)->d[0] == v; 1495 else 1496 tablearg = v; 1497 } else if (is_ipv6) { 1498 uint32_t v = 0; 1499 void *pkey = (cmd->opcode == O_IP_DST_LOOKUP) ? 1500 &args->f_id.dst_ip6: &args->f_id.src_ip6; 1501 match = ipfw_lookup_table_extended(chain, 1502 cmd->arg1, pkey, &v, 1503 IPFW_TABLE_CIDR); 1504 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1505 match = ((ipfw_insn_u32 *)cmd)->d[0] == v; 1506 if (match) 1507 tablearg = v; 1508 } 1509 break; 1510 1511 case O_IP_SRC_MASK: 1512 case O_IP_DST_MASK: 1513 if (is_ipv4) { 1514 uint32_t a = 1515 (cmd->opcode == O_IP_DST_MASK) ? 1516 dst_ip.s_addr : src_ip.s_addr; 1517 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 1518 int i = cmdlen-1; 1519 1520 for (; !match && i>0; i-= 2, p+= 2) 1521 match = (p[0] == (a & p[1])); 1522 } 1523 break; 1524 1525 case O_IP_SRC_ME: 1526 if (is_ipv4) { 1527 struct ifnet *tif; 1528 1529 INADDR_TO_IFP(src_ip, tif); 1530 match = (tif != NULL); 1531 break; 1532 } 1533 #ifdef INET6 1534 /* FALLTHROUGH */ 1535 case O_IP6_SRC_ME: 1536 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6); 1537 #endif 1538 break; 1539 1540 case O_IP_DST_SET: 1541 case O_IP_SRC_SET: 1542 if (is_ipv4) { 1543 u_int32_t *d = (u_int32_t *)(cmd+1); 1544 u_int32_t addr = 1545 cmd->opcode == O_IP_DST_SET ? 1546 args->f_id.dst_ip : 1547 args->f_id.src_ip; 1548 1549 if (addr < d[0]) 1550 break; 1551 addr -= d[0]; /* subtract base */ 1552 match = (addr < cmd->arg1) && 1553 ( d[ 1 + (addr>>5)] & 1554 (1<<(addr & 0x1f)) ); 1555 } 1556 break; 1557 1558 case O_IP_DST: 1559 match = is_ipv4 && 1560 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1561 dst_ip.s_addr); 1562 break; 1563 1564 case O_IP_DST_ME: 1565 if (is_ipv4) { 1566 struct ifnet *tif; 1567 1568 INADDR_TO_IFP(dst_ip, tif); 1569 match = (tif != NULL); 1570 break; 1571 } 1572 #ifdef INET6 1573 /* FALLTHROUGH */ 1574 case O_IP6_DST_ME: 1575 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6); 1576 #endif 1577 break; 1578 1579 1580 case O_IP_SRCPORT: 1581 case O_IP_DSTPORT: 1582 /* 1583 * offset == 0 && proto != 0 is enough 1584 * to guarantee that we have a 1585 * packet with port info. 1586 */ 1587 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP) 1588 && offset == 0) { 1589 u_int16_t x = 1590 (cmd->opcode == O_IP_SRCPORT) ? 1591 src_port : dst_port ; 1592 u_int16_t *p = 1593 ((ipfw_insn_u16 *)cmd)->ports; 1594 int i; 1595 1596 for (i = cmdlen - 1; !match && i>0; 1597 i--, p += 2) 1598 match = (x>=p[0] && x<=p[1]); 1599 } 1600 break; 1601 1602 case O_ICMPTYPE: 1603 match = (offset == 0 && proto==IPPROTO_ICMP && 1604 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 1605 break; 1606 1607 #ifdef INET6 1608 case O_ICMP6TYPE: 1609 match = is_ipv6 && offset == 0 && 1610 proto==IPPROTO_ICMPV6 && 1611 icmp6type_match( 1612 ICMP6(ulp)->icmp6_type, 1613 (ipfw_insn_u32 *)cmd); 1614 break; 1615 #endif /* INET6 */ 1616 1617 case O_IPOPT: 1618 match = (is_ipv4 && 1619 ipopts_match(ip, cmd) ); 1620 break; 1621 1622 case O_IPVER: 1623 match = (is_ipv4 && 1624 cmd->arg1 == ip->ip_v); 1625 break; 1626 1627 case O_IPID: 1628 case O_IPLEN: 1629 case O_IPTTL: 1630 if (is_ipv4) { /* only for IP packets */ 1631 uint16_t x; 1632 uint16_t *p; 1633 int i; 1634 1635 if (cmd->opcode == O_IPLEN) 1636 x = iplen; 1637 else if (cmd->opcode == O_IPTTL) 1638 x = ip->ip_ttl; 1639 else /* must be IPID */ 1640 x = ntohs(ip->ip_id); 1641 if (cmdlen == 1) { 1642 match = (cmd->arg1 == x); 1643 break; 1644 } 1645 /* otherwise we have ranges */ 1646 p = ((ipfw_insn_u16 *)cmd)->ports; 1647 i = cmdlen - 1; 1648 for (; !match && i>0; i--, p += 2) 1649 match = (x >= p[0] && x <= p[1]); 1650 } 1651 break; 1652 1653 case O_IPPRECEDENCE: 1654 match = (is_ipv4 && 1655 (cmd->arg1 == (ip->ip_tos & 0xe0)) ); 1656 break; 1657 1658 case O_IPTOS: 1659 match = (is_ipv4 && 1660 flags_match(cmd, ip->ip_tos)); 1661 break; 1662 1663 case O_DSCP: 1664 { 1665 uint32_t *p; 1666 uint16_t x; 1667 1668 p = ((ipfw_insn_u32 *)cmd)->d; 1669 1670 if (is_ipv4) 1671 x = ip->ip_tos >> 2; 1672 else if (is_ipv6) { 1673 uint8_t *v; 1674 v = &((struct ip6_hdr *)ip)->ip6_vfc; 1675 x = (*v & 0x0F) << 2; 1676 v++; 1677 x |= *v >> 6; 1678 } else 1679 break; 1680 1681 /* DSCP bitmask is stored as low_u32 high_u32 */ 1682 if (x > 32) 1683 match = *(p + 1) & (1 << (x - 32)); 1684 else 1685 match = *p & (1 << x); 1686 } 1687 break; 1688 1689 case O_TCPDATALEN: 1690 if (proto == IPPROTO_TCP && offset == 0) { 1691 struct tcphdr *tcp; 1692 uint16_t x; 1693 uint16_t *p; 1694 int i; 1695 1696 tcp = TCP(ulp); 1697 x = iplen - 1698 ((ip->ip_hl + tcp->th_off) << 2); 1699 if (cmdlen == 1) { 1700 match = (cmd->arg1 == x); 1701 break; 1702 } 1703 /* otherwise we have ranges */ 1704 p = ((ipfw_insn_u16 *)cmd)->ports; 1705 i = cmdlen - 1; 1706 for (; !match && i>0; i--, p += 2) 1707 match = (x >= p[0] && x <= p[1]); 1708 } 1709 break; 1710 1711 case O_TCPFLAGS: 1712 match = (proto == IPPROTO_TCP && offset == 0 && 1713 flags_match(cmd, TCP(ulp)->th_flags)); 1714 break; 1715 1716 case O_TCPOPTS: 1717 PULLUP_LEN(hlen, ulp, (TCP(ulp)->th_off << 2)); 1718 match = (proto == IPPROTO_TCP && offset == 0 && 1719 tcpopts_match(TCP(ulp), cmd)); 1720 break; 1721 1722 case O_TCPSEQ: 1723 match = (proto == IPPROTO_TCP && offset == 0 && 1724 ((ipfw_insn_u32 *)cmd)->d[0] == 1725 TCP(ulp)->th_seq); 1726 break; 1727 1728 case O_TCPACK: 1729 match = (proto == IPPROTO_TCP && offset == 0 && 1730 ((ipfw_insn_u32 *)cmd)->d[0] == 1731 TCP(ulp)->th_ack); 1732 break; 1733 1734 case O_TCPWIN: 1735 if (proto == IPPROTO_TCP && offset == 0) { 1736 uint16_t x; 1737 uint16_t *p; 1738 int i; 1739 1740 x = ntohs(TCP(ulp)->th_win); 1741 if (cmdlen == 1) { 1742 match = (cmd->arg1 == x); 1743 break; 1744 } 1745 /* Otherwise we have ranges. */ 1746 p = ((ipfw_insn_u16 *)cmd)->ports; 1747 i = cmdlen - 1; 1748 for (; !match && i > 0; i--, p += 2) 1749 match = (x >= p[0] && x <= p[1]); 1750 } 1751 break; 1752 1753 case O_ESTAB: 1754 /* reject packets which have SYN only */ 1755 /* XXX should i also check for TH_ACK ? */ 1756 match = (proto == IPPROTO_TCP && offset == 0 && 1757 (TCP(ulp)->th_flags & 1758 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 1759 break; 1760 1761 case O_ALTQ: { 1762 struct pf_mtag *at; 1763 struct m_tag *mtag; 1764 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 1765 1766 /* 1767 * ALTQ uses mbuf tags from another 1768 * packet filtering system - pf(4). 1769 * We allocate a tag in its format 1770 * and fill it in, pretending to be pf(4). 1771 */ 1772 match = 1; 1773 at = pf_find_mtag(m); 1774 if (at != NULL && at->qid != 0) 1775 break; 1776 mtag = m_tag_get(PACKET_TAG_PF, 1777 sizeof(struct pf_mtag), M_NOWAIT | M_ZERO); 1778 if (mtag == NULL) { 1779 /* 1780 * Let the packet fall back to the 1781 * default ALTQ. 1782 */ 1783 break; 1784 } 1785 m_tag_prepend(m, mtag); 1786 at = (struct pf_mtag *)(mtag + 1); 1787 at->qid = altq->qid; 1788 at->hdr = ip; 1789 break; 1790 } 1791 1792 case O_LOG: 1793 ipfw_log(f, hlen, args, m, 1794 oif, offset | ip6f_mf, tablearg, ip); 1795 match = 1; 1796 break; 1797 1798 case O_PROB: 1799 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 1800 break; 1801 1802 case O_VERREVPATH: 1803 /* Outgoing packets automatically pass/match */ 1804 match = ((oif != NULL) || 1805 (m->m_pkthdr.rcvif == NULL) || 1806 ( 1807 #ifdef INET6 1808 is_ipv6 ? 1809 verify_path6(&(args->f_id.src_ip6), 1810 m->m_pkthdr.rcvif, args->f_id.fib) : 1811 #endif 1812 verify_path(src_ip, m->m_pkthdr.rcvif, 1813 args->f_id.fib))); 1814 break; 1815 1816 case O_VERSRCREACH: 1817 /* Outgoing packets automatically pass/match */ 1818 match = (hlen > 0 && ((oif != NULL) || 1819 #ifdef INET6 1820 is_ipv6 ? 1821 verify_path6(&(args->f_id.src_ip6), 1822 NULL, args->f_id.fib) : 1823 #endif 1824 verify_path(src_ip, NULL, args->f_id.fib))); 1825 break; 1826 1827 case O_ANTISPOOF: 1828 /* Outgoing packets automatically pass/match */ 1829 if (oif == NULL && hlen > 0 && 1830 ( (is_ipv4 && in_localaddr(src_ip)) 1831 #ifdef INET6 1832 || (is_ipv6 && 1833 in6_localaddr(&(args->f_id.src_ip6))) 1834 #endif 1835 )) 1836 match = 1837 #ifdef INET6 1838 is_ipv6 ? verify_path6( 1839 &(args->f_id.src_ip6), 1840 m->m_pkthdr.rcvif, 1841 args->f_id.fib) : 1842 #endif 1843 verify_path(src_ip, 1844 m->m_pkthdr.rcvif, 1845 args->f_id.fib); 1846 else 1847 match = 1; 1848 break; 1849 1850 case O_IPSEC: 1851 #ifdef IPSEC 1852 match = (m_tag_find(m, 1853 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 1854 #endif 1855 /* otherwise no match */ 1856 break; 1857 1858 #ifdef INET6 1859 case O_IP6_SRC: 1860 match = is_ipv6 && 1861 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 1862 &((ipfw_insn_ip6 *)cmd)->addr6); 1863 break; 1864 1865 case O_IP6_DST: 1866 match = is_ipv6 && 1867 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 1868 &((ipfw_insn_ip6 *)cmd)->addr6); 1869 break; 1870 case O_IP6_SRC_MASK: 1871 case O_IP6_DST_MASK: 1872 if (is_ipv6) { 1873 int i = cmdlen - 1; 1874 struct in6_addr p; 1875 struct in6_addr *d = 1876 &((ipfw_insn_ip6 *)cmd)->addr6; 1877 1878 for (; !match && i > 0; d += 2, 1879 i -= F_INSN_SIZE(struct in6_addr) 1880 * 2) { 1881 p = (cmd->opcode == 1882 O_IP6_SRC_MASK) ? 1883 args->f_id.src_ip6: 1884 args->f_id.dst_ip6; 1885 APPLY_MASK(&p, &d[1]); 1886 match = 1887 IN6_ARE_ADDR_EQUAL(&d[0], 1888 &p); 1889 } 1890 } 1891 break; 1892 1893 case O_FLOW6ID: 1894 match = is_ipv6 && 1895 flow6id_match(args->f_id.flow_id6, 1896 (ipfw_insn_u32 *) cmd); 1897 break; 1898 1899 case O_EXT_HDR: 1900 match = is_ipv6 && 1901 (ext_hd & ((ipfw_insn *) cmd)->arg1); 1902 break; 1903 1904 case O_IP6: 1905 match = is_ipv6; 1906 break; 1907 #endif 1908 1909 case O_IP4: 1910 match = is_ipv4; 1911 break; 1912 1913 case O_TAG: { 1914 struct m_tag *mtag; 1915 uint32_t tag = IP_FW_ARG_TABLEARG(cmd->arg1); 1916 1917 /* Packet is already tagged with this tag? */ 1918 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 1919 1920 /* We have `untag' action when F_NOT flag is 1921 * present. And we must remove this mtag from 1922 * mbuf and reset `match' to zero (`match' will 1923 * be inversed later). 1924 * Otherwise we should allocate new mtag and 1925 * push it into mbuf. 1926 */ 1927 if (cmd->len & F_NOT) { /* `untag' action */ 1928 if (mtag != NULL) 1929 m_tag_delete(m, mtag); 1930 match = 0; 1931 } else { 1932 if (mtag == NULL) { 1933 mtag = m_tag_alloc( MTAG_IPFW, 1934 tag, 0, M_NOWAIT); 1935 if (mtag != NULL) 1936 m_tag_prepend(m, mtag); 1937 } 1938 match = 1; 1939 } 1940 break; 1941 } 1942 1943 case O_FIB: /* try match the specified fib */ 1944 if (args->f_id.fib == cmd->arg1) 1945 match = 1; 1946 break; 1947 1948 case O_SOCKARG: { 1949 struct inpcb *inp = args->inp; 1950 struct inpcbinfo *pi; 1951 1952 if (is_ipv6) /* XXX can we remove this ? */ 1953 break; 1954 1955 if (proto == IPPROTO_TCP) 1956 pi = &V_tcbinfo; 1957 else if (proto == IPPROTO_UDP) 1958 pi = &V_udbinfo; 1959 else 1960 break; 1961 1962 /* 1963 * XXXRW: so_user_cookie should almost 1964 * certainly be inp_user_cookie? 1965 */ 1966 1967 /* For incomming packet, lookup up the 1968 inpcb using the src/dest ip/port tuple */ 1969 if (inp == NULL) { 1970 inp = in_pcblookup(pi, 1971 src_ip, htons(src_port), 1972 dst_ip, htons(dst_port), 1973 INPLOOKUP_RLOCKPCB, NULL); 1974 if (inp != NULL) { 1975 tablearg = 1976 inp->inp_socket->so_user_cookie; 1977 if (tablearg) 1978 match = 1; 1979 INP_RUNLOCK(inp); 1980 } 1981 } else { 1982 if (inp->inp_socket) { 1983 tablearg = 1984 inp->inp_socket->so_user_cookie; 1985 if (tablearg) 1986 match = 1; 1987 } 1988 } 1989 break; 1990 } 1991 1992 case O_TAGGED: { 1993 struct m_tag *mtag; 1994 uint32_t tag = IP_FW_ARG_TABLEARG(cmd->arg1); 1995 1996 if (cmdlen == 1) { 1997 match = m_tag_locate(m, MTAG_IPFW, 1998 tag, NULL) != NULL; 1999 break; 2000 } 2001 2002 /* we have ranges */ 2003 for (mtag = m_tag_first(m); 2004 mtag != NULL && !match; 2005 mtag = m_tag_next(m, mtag)) { 2006 uint16_t *p; 2007 int i; 2008 2009 if (mtag->m_tag_cookie != MTAG_IPFW) 2010 continue; 2011 2012 p = ((ipfw_insn_u16 *)cmd)->ports; 2013 i = cmdlen - 1; 2014 for(; !match && i > 0; i--, p += 2) 2015 match = 2016 mtag->m_tag_id >= p[0] && 2017 mtag->m_tag_id <= p[1]; 2018 } 2019 break; 2020 } 2021 2022 /* 2023 * The second set of opcodes represents 'actions', 2024 * i.e. the terminal part of a rule once the packet 2025 * matches all previous patterns. 2026 * Typically there is only one action for each rule, 2027 * and the opcode is stored at the end of the rule 2028 * (but there are exceptions -- see below). 2029 * 2030 * In general, here we set retval and terminate the 2031 * outer loop (would be a 'break 3' in some language, 2032 * but we need to set l=0, done=1) 2033 * 2034 * Exceptions: 2035 * O_COUNT and O_SKIPTO actions: 2036 * instead of terminating, we jump to the next rule 2037 * (setting l=0), or to the SKIPTO target (setting 2038 * f/f_len, cmd and l as needed), respectively. 2039 * 2040 * O_TAG, O_LOG and O_ALTQ action parameters: 2041 * perform some action and set match = 1; 2042 * 2043 * O_LIMIT and O_KEEP_STATE: these opcodes are 2044 * not real 'actions', and are stored right 2045 * before the 'action' part of the rule. 2046 * These opcodes try to install an entry in the 2047 * state tables; if successful, we continue with 2048 * the next opcode (match=1; break;), otherwise 2049 * the packet must be dropped (set retval, 2050 * break loops with l=0, done=1) 2051 * 2052 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2053 * cause a lookup of the state table, and a jump 2054 * to the 'action' part of the parent rule 2055 * if an entry is found, or 2056 * (CHECK_STATE only) a jump to the next rule if 2057 * the entry is not found. 2058 * The result of the lookup is cached so that 2059 * further instances of these opcodes become NOPs. 2060 * The jump to the next rule is done by setting 2061 * l=0, cmdlen=0. 2062 */ 2063 case O_LIMIT: 2064 case O_KEEP_STATE: 2065 if (ipfw_install_state(f, 2066 (ipfw_insn_limit *)cmd, args, tablearg)) { 2067 /* error or limit violation */ 2068 retval = IP_FW_DENY; 2069 l = 0; /* exit inner loop */ 2070 done = 1; /* exit outer loop */ 2071 } 2072 match = 1; 2073 break; 2074 2075 case O_PROBE_STATE: 2076 case O_CHECK_STATE: 2077 /* 2078 * dynamic rules are checked at the first 2079 * keep-state or check-state occurrence, 2080 * with the result being stored in dyn_dir. 2081 * The compiler introduces a PROBE_STATE 2082 * instruction for us when we have a 2083 * KEEP_STATE (because PROBE_STATE needs 2084 * to be run first). 2085 */ 2086 if (dyn_dir == MATCH_UNKNOWN && 2087 (q = ipfw_lookup_dyn_rule(&args->f_id, 2088 &dyn_dir, proto == IPPROTO_TCP ? 2089 TCP(ulp) : NULL)) 2090 != NULL) { 2091 /* 2092 * Found dynamic entry, update stats 2093 * and jump to the 'action' part of 2094 * the parent rule by setting 2095 * f, cmd, l and clearing cmdlen. 2096 */ 2097 IPFW_INC_DYN_COUNTER(q, pktlen); 2098 /* XXX we would like to have f_pos 2099 * readily accessible in the dynamic 2100 * rule, instead of having to 2101 * lookup q->rule. 2102 */ 2103 f = q->rule; 2104 f_pos = ipfw_find_rule(chain, 2105 f->rulenum, f->id); 2106 cmd = ACTION_PTR(f); 2107 l = f->cmd_len - f->act_ofs; 2108 ipfw_dyn_unlock(q); 2109 cmdlen = 0; 2110 match = 1; 2111 break; 2112 } 2113 /* 2114 * Dynamic entry not found. If CHECK_STATE, 2115 * skip to next rule, if PROBE_STATE just 2116 * ignore and continue with next opcode. 2117 */ 2118 if (cmd->opcode == O_CHECK_STATE) 2119 l = 0; /* exit inner loop */ 2120 match = 1; 2121 break; 2122 2123 case O_ACCEPT: 2124 retval = 0; /* accept */ 2125 l = 0; /* exit inner loop */ 2126 done = 1; /* exit outer loop */ 2127 break; 2128 2129 case O_PIPE: 2130 case O_QUEUE: 2131 set_match(args, f_pos, chain); 2132 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1); 2133 if (cmd->opcode == O_PIPE) 2134 args->rule.info |= IPFW_IS_PIPE; 2135 if (V_fw_one_pass) 2136 args->rule.info |= IPFW_ONEPASS; 2137 retval = IP_FW_DUMMYNET; 2138 l = 0; /* exit inner loop */ 2139 done = 1; /* exit outer loop */ 2140 break; 2141 2142 case O_DIVERT: 2143 case O_TEE: 2144 if (args->eh) /* not on layer 2 */ 2145 break; 2146 /* otherwise this is terminal */ 2147 l = 0; /* exit inner loop */ 2148 done = 1; /* exit outer loop */ 2149 retval = (cmd->opcode == O_DIVERT) ? 2150 IP_FW_DIVERT : IP_FW_TEE; 2151 set_match(args, f_pos, chain); 2152 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1); 2153 break; 2154 2155 case O_COUNT: 2156 IPFW_INC_RULE_COUNTER(f, pktlen); 2157 l = 0; /* exit inner loop */ 2158 break; 2159 2160 case O_SKIPTO: 2161 IPFW_INC_RULE_COUNTER(f, pktlen); 2162 f_pos = jump_fast(chain, f, cmd->arg1, tablearg, 0); 2163 /* 2164 * Skip disabled rules, and re-enter 2165 * the inner loop with the correct 2166 * f_pos, f, l and cmd. 2167 * Also clear cmdlen and skip_or 2168 */ 2169 for (; f_pos < chain->n_rules - 1 && 2170 (V_set_disable & 2171 (1 << chain->map[f_pos]->set)); 2172 f_pos++) 2173 ; 2174 /* Re-enter the inner loop at the skipto rule. */ 2175 f = chain->map[f_pos]; 2176 l = f->cmd_len; 2177 cmd = f->cmd; 2178 match = 1; 2179 cmdlen = 0; 2180 skip_or = 0; 2181 continue; 2182 break; /* not reached */ 2183 2184 case O_CALLRETURN: { 2185 /* 2186 * Implementation of `subroutine' call/return, 2187 * in the stack carried in an mbuf tag. This 2188 * is different from `skipto' in that any call 2189 * address is possible (`skipto' must prevent 2190 * backward jumps to avoid endless loops). 2191 * We have `return' action when F_NOT flag is 2192 * present. The `m_tag_id' field is used as 2193 * stack pointer. 2194 */ 2195 struct m_tag *mtag; 2196 uint16_t jmpto, *stack; 2197 2198 #define IS_CALL ((cmd->len & F_NOT) == 0) 2199 #define IS_RETURN ((cmd->len & F_NOT) != 0) 2200 /* 2201 * Hand-rolled version of m_tag_locate() with 2202 * wildcard `type'. 2203 * If not already tagged, allocate new tag. 2204 */ 2205 mtag = m_tag_first(m); 2206 while (mtag != NULL) { 2207 if (mtag->m_tag_cookie == 2208 MTAG_IPFW_CALL) 2209 break; 2210 mtag = m_tag_next(m, mtag); 2211 } 2212 if (mtag == NULL && IS_CALL) { 2213 mtag = m_tag_alloc(MTAG_IPFW_CALL, 0, 2214 IPFW_CALLSTACK_SIZE * 2215 sizeof(uint16_t), M_NOWAIT); 2216 if (mtag != NULL) 2217 m_tag_prepend(m, mtag); 2218 } 2219 2220 /* 2221 * On error both `call' and `return' just 2222 * continue with next rule. 2223 */ 2224 if (IS_RETURN && (mtag == NULL || 2225 mtag->m_tag_id == 0)) { 2226 l = 0; /* exit inner loop */ 2227 break; 2228 } 2229 if (IS_CALL && (mtag == NULL || 2230 mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) { 2231 printf("ipfw: call stack error, " 2232 "go to next rule\n"); 2233 l = 0; /* exit inner loop */ 2234 break; 2235 } 2236 2237 IPFW_INC_RULE_COUNTER(f, pktlen); 2238 stack = (uint16_t *)(mtag + 1); 2239 2240 /* 2241 * The `call' action may use cached f_pos 2242 * (in f->next_rule), whose version is written 2243 * in f->next_rule. 2244 * The `return' action, however, doesn't have 2245 * fixed jump address in cmd->arg1 and can't use 2246 * cache. 2247 */ 2248 if (IS_CALL) { 2249 stack[mtag->m_tag_id] = f->rulenum; 2250 mtag->m_tag_id++; 2251 f_pos = jump_fast(chain, f, cmd->arg1, 2252 tablearg, 1); 2253 } else { /* `return' action */ 2254 mtag->m_tag_id--; 2255 jmpto = stack[mtag->m_tag_id] + 1; 2256 f_pos = ipfw_find_rule(chain, jmpto, 0); 2257 } 2258 2259 /* 2260 * Skip disabled rules, and re-enter 2261 * the inner loop with the correct 2262 * f_pos, f, l and cmd. 2263 * Also clear cmdlen and skip_or 2264 */ 2265 for (; f_pos < chain->n_rules - 1 && 2266 (V_set_disable & 2267 (1 << chain->map[f_pos]->set)); f_pos++) 2268 ; 2269 /* Re-enter the inner loop at the dest rule. */ 2270 f = chain->map[f_pos]; 2271 l = f->cmd_len; 2272 cmd = f->cmd; 2273 cmdlen = 0; 2274 skip_or = 0; 2275 continue; 2276 break; /* NOTREACHED */ 2277 } 2278 #undef IS_CALL 2279 #undef IS_RETURN 2280 2281 case O_REJECT: 2282 /* 2283 * Drop the packet and send a reject notice 2284 * if the packet is not ICMP (or is an ICMP 2285 * query), and it is not multicast/broadcast. 2286 */ 2287 if (hlen > 0 && is_ipv4 && offset == 0 && 2288 (proto != IPPROTO_ICMP || 2289 is_icmp_query(ICMP(ulp))) && 2290 !(m->m_flags & (M_BCAST|M_MCAST)) && 2291 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 2292 send_reject(args, cmd->arg1, iplen, ip); 2293 m = args->m; 2294 } 2295 /* FALLTHROUGH */ 2296 #ifdef INET6 2297 case O_UNREACH6: 2298 if (hlen > 0 && is_ipv6 && 2299 ((offset & IP6F_OFF_MASK) == 0) && 2300 (proto != IPPROTO_ICMPV6 || 2301 (is_icmp6_query(icmp6_type) == 1)) && 2302 !(m->m_flags & (M_BCAST|M_MCAST)) && 2303 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 2304 send_reject6( 2305 args, cmd->arg1, hlen, 2306 (struct ip6_hdr *)ip); 2307 m = args->m; 2308 } 2309 /* FALLTHROUGH */ 2310 #endif 2311 case O_DENY: 2312 retval = IP_FW_DENY; 2313 l = 0; /* exit inner loop */ 2314 done = 1; /* exit outer loop */ 2315 break; 2316 2317 case O_FORWARD_IP: 2318 if (args->eh) /* not valid on layer2 pkts */ 2319 break; 2320 if (q == NULL || q->rule != f || 2321 dyn_dir == MATCH_FORWARD) { 2322 struct sockaddr_in *sa; 2323 sa = &(((ipfw_insn_sa *)cmd)->sa); 2324 if (sa->sin_addr.s_addr == INADDR_ANY) { 2325 bcopy(sa, &args->hopstore, 2326 sizeof(*sa)); 2327 args->hopstore.sin_addr.s_addr = 2328 htonl(tablearg); 2329 args->next_hop = &args->hopstore; 2330 } else { 2331 args->next_hop = sa; 2332 } 2333 } 2334 retval = IP_FW_PASS; 2335 l = 0; /* exit inner loop */ 2336 done = 1; /* exit outer loop */ 2337 break; 2338 2339 #ifdef INET6 2340 case O_FORWARD_IP6: 2341 if (args->eh) /* not valid on layer2 pkts */ 2342 break; 2343 if (q == NULL || q->rule != f || 2344 dyn_dir == MATCH_FORWARD) { 2345 struct sockaddr_in6 *sin6; 2346 2347 sin6 = &(((ipfw_insn_sa6 *)cmd)->sa); 2348 args->next_hop6 = sin6; 2349 } 2350 retval = IP_FW_PASS; 2351 l = 0; /* exit inner loop */ 2352 done = 1; /* exit outer loop */ 2353 break; 2354 #endif 2355 2356 case O_NETGRAPH: 2357 case O_NGTEE: 2358 set_match(args, f_pos, chain); 2359 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1); 2360 if (V_fw_one_pass) 2361 args->rule.info |= IPFW_ONEPASS; 2362 retval = (cmd->opcode == O_NETGRAPH) ? 2363 IP_FW_NETGRAPH : IP_FW_NGTEE; 2364 l = 0; /* exit inner loop */ 2365 done = 1; /* exit outer loop */ 2366 break; 2367 2368 case O_SETFIB: { 2369 uint32_t fib; 2370 2371 IPFW_INC_RULE_COUNTER(f, pktlen); 2372 fib = IP_FW_ARG_TABLEARG(cmd->arg1); 2373 if (fib >= rt_numfibs) 2374 fib = 0; 2375 M_SETFIB(m, fib); 2376 args->f_id.fib = fib; 2377 l = 0; /* exit inner loop */ 2378 break; 2379 } 2380 2381 case O_SETDSCP: { 2382 uint16_t code; 2383 2384 code = IP_FW_ARG_TABLEARG(cmd->arg1) & 0x3F; 2385 l = 0; /* exit inner loop */ 2386 if (is_ipv4) { 2387 uint16_t a; 2388 2389 a = ip->ip_tos; 2390 ip->ip_tos = (code << 2) | (ip->ip_tos & 0x03); 2391 a += ntohs(ip->ip_sum) - ip->ip_tos; 2392 ip->ip_sum = htons(a); 2393 } else if (is_ipv6) { 2394 uint8_t *v; 2395 2396 v = &((struct ip6_hdr *)ip)->ip6_vfc; 2397 *v = (*v & 0xF0) | (code >> 2); 2398 v++; 2399 *v = (*v & 0x3F) | ((code & 0x03) << 6); 2400 } else 2401 break; 2402 2403 IPFW_INC_RULE_COUNTER(f, pktlen); 2404 break; 2405 } 2406 2407 case O_NAT: 2408 if (!IPFW_NAT_LOADED) { 2409 retval = IP_FW_DENY; 2410 } else { 2411 struct cfg_nat *t; 2412 int nat_id; 2413 2414 set_match(args, f_pos, chain); 2415 /* Check if this is 'global' nat rule */ 2416 if (cmd->arg1 == 0) { 2417 retval = ipfw_nat_ptr(args, NULL, m); 2418 l = 0; 2419 done = 1; 2420 break; 2421 } 2422 t = ((ipfw_insn_nat *)cmd)->nat; 2423 if (t == NULL) { 2424 nat_id = IP_FW_ARG_TABLEARG(cmd->arg1); 2425 t = (*lookup_nat_ptr)(&chain->nat, nat_id); 2426 2427 if (t == NULL) { 2428 retval = IP_FW_DENY; 2429 l = 0; /* exit inner loop */ 2430 done = 1; /* exit outer loop */ 2431 break; 2432 } 2433 if (cmd->arg1 != IP_FW_TABLEARG) 2434 ((ipfw_insn_nat *)cmd)->nat = t; 2435 } 2436 retval = ipfw_nat_ptr(args, t, m); 2437 } 2438 l = 0; /* exit inner loop */ 2439 done = 1; /* exit outer loop */ 2440 break; 2441 2442 case O_REASS: { 2443 int ip_off; 2444 2445 IPFW_INC_RULE_COUNTER(f, pktlen); 2446 l = 0; /* in any case exit inner loop */ 2447 ip_off = ntohs(ip->ip_off); 2448 2449 /* if not fragmented, go to next rule */ 2450 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0) 2451 break; 2452 2453 args->m = m = ip_reass(m); 2454 2455 /* 2456 * do IP header checksum fixup. 2457 */ 2458 if (m == NULL) { /* fragment got swallowed */ 2459 retval = IP_FW_DENY; 2460 } else { /* good, packet complete */ 2461 int hlen; 2462 2463 ip = mtod(m, struct ip *); 2464 hlen = ip->ip_hl << 2; 2465 ip->ip_sum = 0; 2466 if (hlen == sizeof(struct ip)) 2467 ip->ip_sum = in_cksum_hdr(ip); 2468 else 2469 ip->ip_sum = in_cksum(m, hlen); 2470 retval = IP_FW_REASS; 2471 set_match(args, f_pos, chain); 2472 } 2473 done = 1; /* exit outer loop */ 2474 break; 2475 } 2476 2477 default: 2478 panic("-- unknown opcode %d\n", cmd->opcode); 2479 } /* end of switch() on opcodes */ 2480 /* 2481 * if we get here with l=0, then match is irrelevant. 2482 */ 2483 2484 if (cmd->len & F_NOT) 2485 match = !match; 2486 2487 if (match) { 2488 if (cmd->len & F_OR) 2489 skip_or = 1; 2490 } else { 2491 if (!(cmd->len & F_OR)) /* not an OR block, */ 2492 break; /* try next rule */ 2493 } 2494 2495 } /* end of inner loop, scan opcodes */ 2496 #undef PULLUP_LEN 2497 2498 if (done) 2499 break; 2500 2501 /* next_rule:; */ /* try next rule */ 2502 2503 } /* end of outer for, scan rules */ 2504 2505 if (done) { 2506 struct ip_fw *rule = chain->map[f_pos]; 2507 /* Update statistics */ 2508 IPFW_INC_RULE_COUNTER(rule, pktlen); 2509 } else { 2510 retval = IP_FW_DENY; 2511 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 2512 } 2513 IPFW_PF_RUNLOCK(chain); 2514 #ifdef __FreeBSD__ 2515 if (ucred_cache != NULL) 2516 crfree(ucred_cache); 2517 #endif 2518 return (retval); 2519 2520 pullup_failed: 2521 if (V_fw_verbose) 2522 printf("ipfw: pullup failed\n"); 2523 return (IP_FW_DENY); 2524 } 2525 2526 /* 2527 * Set maximum number of tables that can be used in given VNET ipfw instance. 2528 */ 2529 #ifdef SYSCTL_NODE 2530 static int 2531 sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS) 2532 { 2533 int error; 2534 unsigned int ntables; 2535 2536 ntables = V_fw_tables_max; 2537 2538 error = sysctl_handle_int(oidp, &ntables, 0, req); 2539 /* Read operation or some error */ 2540 if ((error != 0) || (req->newptr == NULL)) 2541 return (error); 2542 2543 return (ipfw_resize_tables(&V_layer3_chain, ntables)); 2544 } 2545 #endif 2546 /* 2547 * Module and VNET glue 2548 */ 2549 2550 /* 2551 * Stuff that must be initialised only on boot or module load 2552 */ 2553 static int 2554 ipfw_init(void) 2555 { 2556 int error = 0; 2557 2558 /* 2559 * Only print out this stuff the first time around, 2560 * when called from the sysinit code. 2561 */ 2562 printf("ipfw2 " 2563 #ifdef INET6 2564 "(+ipv6) " 2565 #endif 2566 "initialized, divert %s, nat %s, " 2567 "default to %s, logging ", 2568 #ifdef IPDIVERT 2569 "enabled", 2570 #else 2571 "loadable", 2572 #endif 2573 #ifdef IPFIREWALL_NAT 2574 "enabled", 2575 #else 2576 "loadable", 2577 #endif 2578 default_to_accept ? "accept" : "deny"); 2579 2580 /* 2581 * Note: V_xxx variables can be accessed here but the vnet specific 2582 * initializer may not have been called yet for the VIMAGE case. 2583 * Tuneables will have been processed. We will print out values for 2584 * the default vnet. 2585 * XXX This should all be rationalized AFTER 8.0 2586 */ 2587 if (V_fw_verbose == 0) 2588 printf("disabled\n"); 2589 else if (V_verbose_limit == 0) 2590 printf("unlimited\n"); 2591 else 2592 printf("limited to %d packets/entry by default\n", 2593 V_verbose_limit); 2594 2595 /* Check user-supplied table count for validness */ 2596 if (default_fw_tables > IPFW_TABLES_MAX) 2597 default_fw_tables = IPFW_TABLES_MAX; 2598 2599 ipfw_log_bpf(1); /* init */ 2600 return (error); 2601 } 2602 2603 /* 2604 * Called for the removal of the last instance only on module unload. 2605 */ 2606 static void 2607 ipfw_destroy(void) 2608 { 2609 2610 ipfw_log_bpf(0); /* uninit */ 2611 printf("IP firewall unloaded\n"); 2612 } 2613 2614 /* 2615 * Stuff that must be initialized for every instance 2616 * (including the first of course). 2617 */ 2618 static int 2619 vnet_ipfw_init(const void *unused) 2620 { 2621 int error; 2622 struct ip_fw *rule = NULL; 2623 struct ip_fw_chain *chain; 2624 2625 chain = &V_layer3_chain; 2626 2627 /* First set up some values that are compile time options */ 2628 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 2629 V_fw_deny_unknown_exthdrs = 1; 2630 #ifdef IPFIREWALL_VERBOSE 2631 V_fw_verbose = 1; 2632 #endif 2633 #ifdef IPFIREWALL_VERBOSE_LIMIT 2634 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 2635 #endif 2636 #ifdef IPFIREWALL_NAT 2637 LIST_INIT(&chain->nat); 2638 #endif 2639 2640 /* insert the default rule and create the initial map */ 2641 chain->n_rules = 1; 2642 chain->static_len = sizeof(struct ip_fw); 2643 chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_WAITOK | M_ZERO); 2644 if (chain->map) 2645 rule = malloc(chain->static_len, M_IPFW, M_WAITOK | M_ZERO); 2646 2647 /* Set initial number of tables */ 2648 V_fw_tables_max = default_fw_tables; 2649 error = ipfw_init_tables(chain); 2650 if (error) { 2651 printf("ipfw2: setting up tables failed\n"); 2652 free(chain->map, M_IPFW); 2653 free(rule, M_IPFW); 2654 return (ENOSPC); 2655 } 2656 2657 /* fill and insert the default rule */ 2658 rule->act_ofs = 0; 2659 rule->rulenum = IPFW_DEFAULT_RULE; 2660 rule->cmd_len = 1; 2661 rule->set = RESVD_SET; 2662 rule->cmd[0].len = 1; 2663 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY; 2664 chain->rules = chain->default_rule = chain->map[0] = rule; 2665 chain->id = rule->id = 1; 2666 2667 IPFW_LOCK_INIT(chain); 2668 ipfw_dyn_init(chain); 2669 2670 /* First set up some values that are compile time options */ 2671 V_ipfw_vnet_ready = 1; /* Open for business */ 2672 2673 /* 2674 * Hook the sockopt handler and pfil hooks for ipv4 and ipv6. 2675 * Even if the latter two fail we still keep the module alive 2676 * because the sockopt and layer2 paths are still useful. 2677 * ipfw[6]_hook return 0 on success, ENOENT on failure, 2678 * so we can ignore the exact return value and just set a flag. 2679 * 2680 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so 2681 * changes in the underlying (per-vnet) variables trigger 2682 * immediate hook()/unhook() calls. 2683 * In layer2 we have the same behaviour, except that V_ether_ipfw 2684 * is checked on each packet because there are no pfil hooks. 2685 */ 2686 V_ip_fw_ctl_ptr = ipfw_ctl; 2687 error = ipfw_attach_hooks(1); 2688 return (error); 2689 } 2690 2691 /* 2692 * Called for the removal of each instance. 2693 */ 2694 static int 2695 vnet_ipfw_uninit(const void *unused) 2696 { 2697 struct ip_fw *reap, *rule; 2698 struct ip_fw_chain *chain = &V_layer3_chain; 2699 int i; 2700 2701 V_ipfw_vnet_ready = 0; /* tell new callers to go away */ 2702 /* 2703 * disconnect from ipv4, ipv6, layer2 and sockopt. 2704 * Then grab, release and grab again the WLOCK so we make 2705 * sure the update is propagated and nobody will be in. 2706 */ 2707 (void)ipfw_attach_hooks(0 /* detach */); 2708 V_ip_fw_ctl_ptr = NULL; 2709 IPFW_UH_WLOCK(chain); 2710 IPFW_UH_WUNLOCK(chain); 2711 IPFW_UH_WLOCK(chain); 2712 2713 IPFW_WLOCK(chain); 2714 ipfw_dyn_uninit(0); /* run the callout_drain */ 2715 IPFW_WUNLOCK(chain); 2716 2717 ipfw_destroy_tables(chain); 2718 reap = NULL; 2719 IPFW_WLOCK(chain); 2720 for (i = 0; i < chain->n_rules; i++) { 2721 rule = chain->map[i]; 2722 rule->x_next = reap; 2723 reap = rule; 2724 } 2725 if (chain->map) 2726 free(chain->map, M_IPFW); 2727 IPFW_WUNLOCK(chain); 2728 IPFW_UH_WUNLOCK(chain); 2729 if (reap != NULL) 2730 ipfw_reap_rules(reap); 2731 IPFW_LOCK_DESTROY(chain); 2732 ipfw_dyn_uninit(1); /* free the remaining parts */ 2733 return 0; 2734 } 2735 2736 /* 2737 * Module event handler. 2738 * In general we have the choice of handling most of these events by the 2739 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to 2740 * use the SYSINIT handlers as they are more capable of expressing the 2741 * flow of control during module and vnet operations, so this is just 2742 * a skeleton. Note there is no SYSINIT equivalent of the module 2743 * SHUTDOWN handler, but we don't have anything to do in that case anyhow. 2744 */ 2745 static int 2746 ipfw_modevent(module_t mod, int type, void *unused) 2747 { 2748 int err = 0; 2749 2750 switch (type) { 2751 case MOD_LOAD: 2752 /* Called once at module load or 2753 * system boot if compiled in. */ 2754 break; 2755 case MOD_QUIESCE: 2756 /* Called before unload. May veto unloading. */ 2757 break; 2758 case MOD_UNLOAD: 2759 /* Called during unload. */ 2760 break; 2761 case MOD_SHUTDOWN: 2762 /* Called during system shutdown. */ 2763 break; 2764 default: 2765 err = EOPNOTSUPP; 2766 break; 2767 } 2768 return err; 2769 } 2770 2771 static moduledata_t ipfwmod = { 2772 "ipfw", 2773 ipfw_modevent, 2774 0 2775 }; 2776 2777 /* Define startup order. */ 2778 #define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_IFATTACHDOMAIN 2779 #define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */ 2780 #define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */ 2781 #define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */ 2782 2783 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER); 2784 MODULE_VERSION(ipfw, 2); 2785 /* should declare some dependencies here */ 2786 2787 /* 2788 * Starting up. Done in order after ipfwmod() has been called. 2789 * VNET_SYSINIT is also called for each existing vnet and each new vnet. 2790 */ 2791 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 2792 ipfw_init, NULL); 2793 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 2794 vnet_ipfw_init, NULL); 2795 2796 /* 2797 * Closing up shop. These are done in REVERSE ORDER, but still 2798 * after ipfwmod() has been called. Not called on reboot. 2799 * VNET_SYSUNINIT is also called for each exiting vnet as it exits. 2800 * or when the module is unloaded. 2801 */ 2802 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 2803 ipfw_destroy, NULL); 2804 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 2805 vnet_ipfw_uninit, NULL); 2806 /* end of file */ 2807