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