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