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sys/netpfil/ipfw/ip_fw2.c
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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: releng/10.1/sys/netpfil/ipfw/ip_fw2.c 265700 2014-05-08 19:11:41Z melifaro $"); 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/pfil.h> 64 #include <net/vnet.h> 65 66 #include <netpfil/pf/pf_mtag.h> 67 68 #include <netinet/in.h> 69 #include <netinet/in_var.h> 70 #include <netinet/in_pcb.h> 71 #include <netinet/ip.h> 72 #include <netinet/ip_var.h> 73 #include <netinet/ip_icmp.h> 74 #include <netinet/ip_fw.h> 75 #include <netinet/ip_carp.h> 76 #include <netinet/pim.h> 77 #include <netinet/tcp_var.h> 78 #include <netinet/udp.h> 79 #include <netinet/udp_var.h> 80 #include <netinet/sctp.h> 81 82 #include <netinet/ip6.h> 83 #include <netinet/icmp6.h> 84 #ifdef INET6 85 #include <netinet6/in6_pcb.h> 86 #include <netinet6/scope6_var.h> 87 #include <netinet6/ip6_var.h> 88 #endif 89 90 #include <netpfil/ipfw/ip_fw_private.h> 91 92 #include <machine/in_cksum.h> /* XXX for in_cksum */ 93 94 #ifdef MAC 95 #include <security/mac/mac_framework.h> 96 #endif 97 98 /* 99 * static variables followed by global ones. 100 * All ipfw global variables are here. 101 */ 102 103 /* ipfw_vnet_ready controls when we are open for business */ 104 static VNET_DEFINE(int, ipfw_vnet_ready) = 0; 105 #define V_ipfw_vnet_ready VNET(ipfw_vnet_ready) 106 107 static VNET_DEFINE(int, fw_deny_unknown_exthdrs); 108 #define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs) 109 110 static VNET_DEFINE(int, fw_permit_single_frag6) = 1; 111 #define V_fw_permit_single_frag6 VNET(fw_permit_single_frag6) 112 113 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 114 static int default_to_accept = 1; 115 #else 116 static int default_to_accept; 117 #endif 118 119 VNET_DEFINE(int, autoinc_step); 120 VNET_DEFINE(int, fw_one_pass) = 1; 121 122 VNET_DEFINE(unsigned int, fw_tables_max); 123 /* Use 128 tables by default */ 124 static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT; 125 126 /* 127 * Each rule belongs to one of 32 different sets (0..31). 128 * The variable set_disable contains one bit per set. 129 * If the bit is set, all rules in the corresponding set 130 * are disabled. Set RESVD_SET(31) is reserved for the default rule 131 * and rules that are not deleted by the flush command, 132 * and CANNOT be disabled. 133 * Rules in set RESVD_SET can only be deleted individually. 134 */ 135 VNET_DEFINE(u_int32_t, set_disable); 136 #define V_set_disable VNET(set_disable) 137 138 VNET_DEFINE(int, fw_verbose); 139 /* counter for ipfw_log(NULL...) */ 140 VNET_DEFINE(u_int64_t, norule_counter); 141 VNET_DEFINE(int, verbose_limit); 142 143 /* layer3_chain contains the list of rules for layer 3 */ 144 VNET_DEFINE(struct ip_fw_chain, layer3_chain); 145 146 VNET_DEFINE(int, ipfw_nat_ready) = 0; 147 148 ipfw_nat_t *ipfw_nat_ptr = NULL; 149 struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int); 150 ipfw_nat_cfg_t *ipfw_nat_cfg_ptr; 151 ipfw_nat_cfg_t *ipfw_nat_del_ptr; 152 ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr; 153 ipfw_nat_cfg_t *ipfw_nat_get_log_ptr; 154 155 #ifdef SYSCTL_NODE 156 uint32_t dummy_def = IPFW_DEFAULT_RULE; 157 static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS); 158 159 SYSBEGIN(f3) 160 161 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 162 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 163 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0, 164 "Only do a single pass through ipfw when using dummynet(4)"); 165 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, 166 CTLFLAG_RW, &VNET_NAME(autoinc_step), 0, 167 "Rule number auto-increment step"); 168 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose, 169 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0, 170 "Log matches to ipfw rules"); 171 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, 172 CTLFLAG_RW, &VNET_NAME(verbose_limit), 0, 173 "Set upper limit of matches of ipfw rules logged"); 174 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD, 175 &dummy_def, 0, 176 "The default/max possible rule number."); 177 SYSCTL_VNET_PROC(_net_inet_ip_fw, OID_AUTO, tables_max, 178 CTLTYPE_UINT|CTLFLAG_RW, 0, 0, sysctl_ipfw_table_num, "IU", 179 "Maximum number of tables"); 180 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN, 181 &default_to_accept, 0, 182 "Make the default rule accept all packets."); 183 TUNABLE_INT("net.inet.ip.fw.default_to_accept", &default_to_accept); 184 TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables); 185 SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, static_count, 186 CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0, 187 "Number of static rules"); 188 189 #ifdef INET6 190 SYSCTL_DECL(_net_inet6_ip6); 191 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 192 SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs, 193 CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_deny_unknown_exthdrs), 0, 194 "Deny packets with unknown IPv6 Extension Headers"); 195 SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6, 196 CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_permit_single_frag6), 0, 197 "Permit single packet IPv6 fragments"); 198 #endif /* INET6 */ 199 200 SYSEND 201 202 #endif /* SYSCTL_NODE */ 203 204 205 /* 206 * Some macros used in the various matching options. 207 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 208 * Other macros just cast void * into the appropriate type 209 */ 210 #define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 211 #define TCP(p) ((struct tcphdr *)(p)) 212 #define SCTP(p) ((struct sctphdr *)(p)) 213 #define UDP(p) ((struct udphdr *)(p)) 214 #define ICMP(p) ((struct icmphdr *)(p)) 215 #define ICMP6(p) ((struct icmp6_hdr *)(p)) 216 217 static __inline int 218 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 219 { 220 int type = icmp->icmp_type; 221 222 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 223 } 224 225 #define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 226 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 227 228 static int 229 is_icmp_query(struct icmphdr *icmp) 230 { 231 int type = icmp->icmp_type; 232 233 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 234 } 235 #undef TT 236 237 /* 238 * The following checks use two arrays of 8 or 16 bits to store the 239 * bits that we want set or clear, respectively. They are in the 240 * low and high half of cmd->arg1 or cmd->d[0]. 241 * 242 * We scan options and store the bits we find set. We succeed if 243 * 244 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 245 * 246 * The code is sometimes optimized not to store additional variables. 247 */ 248 249 static int 250 flags_match(ipfw_insn *cmd, u_int8_t bits) 251 { 252 u_char want_clear; 253 bits = ~bits; 254 255 if ( ((cmd->arg1 & 0xff) & bits) != 0) 256 return 0; /* some bits we want set were clear */ 257 want_clear = (cmd->arg1 >> 8) & 0xff; 258 if ( (want_clear & bits) != want_clear) 259 return 0; /* some bits we want clear were set */ 260 return 1; 261 } 262 263 static int 264 ipopts_match(struct ip *ip, ipfw_insn *cmd) 265 { 266 int optlen, bits = 0; 267 u_char *cp = (u_char *)(ip + 1); 268 int x = (ip->ip_hl << 2) - sizeof (struct ip); 269 270 for (; x > 0; x -= optlen, cp += optlen) { 271 int opt = cp[IPOPT_OPTVAL]; 272 273 if (opt == IPOPT_EOL) 274 break; 275 if (opt == IPOPT_NOP) 276 optlen = 1; 277 else { 278 optlen = cp[IPOPT_OLEN]; 279 if (optlen <= 0 || optlen > x) 280 return 0; /* invalid or truncated */ 281 } 282 switch (opt) { 283 284 default: 285 break; 286 287 case IPOPT_LSRR: 288 bits |= IP_FW_IPOPT_LSRR; 289 break; 290 291 case IPOPT_SSRR: 292 bits |= IP_FW_IPOPT_SSRR; 293 break; 294 295 case IPOPT_RR: 296 bits |= IP_FW_IPOPT_RR; 297 break; 298 299 case IPOPT_TS: 300 bits |= IP_FW_IPOPT_TS; 301 break; 302 } 303 } 304 return (flags_match(cmd, bits)); 305 } 306 307 static int 308 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 309 { 310 int optlen, bits = 0; 311 u_char *cp = (u_char *)(tcp + 1); 312 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 313 314 for (; x > 0; x -= optlen, cp += optlen) { 315 int opt = cp[0]; 316 if (opt == TCPOPT_EOL) 317 break; 318 if (opt == TCPOPT_NOP) 319 optlen = 1; 320 else { 321 optlen = cp[1]; 322 if (optlen <= 0) 323 break; 324 } 325 326 switch (opt) { 327 328 default: 329 break; 330 331 case TCPOPT_MAXSEG: 332 bits |= IP_FW_TCPOPT_MSS; 333 break; 334 335 case TCPOPT_WINDOW: 336 bits |= IP_FW_TCPOPT_WINDOW; 337 break; 338 339 case TCPOPT_SACK_PERMITTED: 340 case TCPOPT_SACK: 341 bits |= IP_FW_TCPOPT_SACK; 342 break; 343 344 case TCPOPT_TIMESTAMP: 345 bits |= IP_FW_TCPOPT_TS; 346 break; 347 348 } 349 } 350 return (flags_match(cmd, bits)); 351 } 352 353 static int 354 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain, uint32_t *tablearg) 355 { 356 if (ifp == NULL) /* no iface with this packet, match fails */ 357 return 0; 358 /* Check by name or by IP address */ 359 if (cmd->name[0] != '\0') { /* match by name */ 360 if (cmd->name[0] == '\1') /* use tablearg to match */ 361 return ipfw_lookup_table_extended(chain, cmd->p.glob, 362 ifp->if_xname, tablearg, IPFW_TABLE_INTERFACE); 363 /* Check name */ 364 if (cmd->p.glob) { 365 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 366 return(1); 367 } else { 368 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 369 return(1); 370 } 371 } else { 372 #ifdef __FreeBSD__ /* and OSX too ? */ 373 struct ifaddr *ia; 374 375 if_addr_rlock(ifp); 376 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 377 if (ia->ifa_addr->sa_family != AF_INET) 378 continue; 379 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 380 (ia->ifa_addr))->sin_addr.s_addr) { 381 if_addr_runlock(ifp); 382 return(1); /* match */ 383 } 384 } 385 if_addr_runlock(ifp); 386 #endif /* __FreeBSD__ */ 387 } 388 return(0); /* no match, fail ... */ 389 } 390 391 /* 392 * The verify_path function checks if a route to the src exists and 393 * if it is reachable via ifp (when provided). 394 * 395 * The 'verrevpath' option checks that the interface that an IP packet 396 * arrives on is the same interface that traffic destined for the 397 * packet's source address would be routed out of. 398 * The 'versrcreach' option just checks that the source address is 399 * reachable via any route (except default) in the routing table. 400 * These two are a measure to block forged packets. This is also 401 * commonly known as "anti-spoofing" or Unicast Reverse Path 402 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 403 * is purposely reminiscent of the Cisco IOS command, 404 * 405 * ip verify unicast reverse-path 406 * ip verify unicast source reachable-via any 407 * 408 * which implements the same functionality. But note that the syntax 409 * is misleading, and the check may be performed on all IP packets 410 * whether unicast, multicast, or broadcast. 411 */ 412 static int 413 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib) 414 { 415 #ifndef __FreeBSD__ 416 return 0; 417 #else 418 struct route ro; 419 struct sockaddr_in *dst; 420 421 bzero(&ro, sizeof(ro)); 422 423 dst = (struct sockaddr_in *)&(ro.ro_dst); 424 dst->sin_family = AF_INET; 425 dst->sin_len = sizeof(*dst); 426 dst->sin_addr = src; 427 in_rtalloc_ign(&ro, 0, fib); 428 429 if (ro.ro_rt == NULL) 430 return 0; 431 432 /* 433 * If ifp is provided, check for equality with rtentry. 434 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 435 * in order to pass packets injected back by if_simloop(): 436 * if useloopback == 1 routing entry (via lo0) for our own address 437 * may exist, so we need to handle routing assymetry. 438 */ 439 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 440 RTFREE(ro.ro_rt); 441 return 0; 442 } 443 444 /* if no ifp provided, check if rtentry is not default route */ 445 if (ifp == NULL && 446 satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) { 447 RTFREE(ro.ro_rt); 448 return 0; 449 } 450 451 /* or if this is a blackhole/reject route */ 452 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 453 RTFREE(ro.ro_rt); 454 return 0; 455 } 456 457 /* found valid route */ 458 RTFREE(ro.ro_rt); 459 return 1; 460 #endif /* __FreeBSD__ */ 461 } 462 463 #ifdef INET6 464 /* 465 * ipv6 specific rules here... 466 */ 467 static __inline int 468 icmp6type_match (int type, ipfw_insn_u32 *cmd) 469 { 470 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 471 } 472 473 static int 474 flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 475 { 476 int i; 477 for (i=0; i <= cmd->o.arg1; ++i ) 478 if (curr_flow == cmd->d[i] ) 479 return 1; 480 return 0; 481 } 482 483 /* support for IP6_*_ME opcodes */ 484 static int 485 search_ip6_addr_net (struct in6_addr * ip6_addr) 486 { 487 struct ifnet *mdc; 488 struct ifaddr *mdc2; 489 struct in6_ifaddr *fdm; 490 struct in6_addr copia; 491 492 TAILQ_FOREACH(mdc, &V_ifnet, if_link) { 493 if_addr_rlock(mdc); 494 TAILQ_FOREACH(mdc2, &mdc->if_addrhead, ifa_link) { 495 if (mdc2->ifa_addr->sa_family == AF_INET6) { 496 fdm = (struct in6_ifaddr *)mdc2; 497 copia = fdm->ia_addr.sin6_addr; 498 /* need for leaving scope_id in the sock_addr */ 499 in6_clearscope(&copia); 500 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) { 501 if_addr_runlock(mdc); 502 return 1; 503 } 504 } 505 } 506 if_addr_runlock(mdc); 507 } 508 return 0; 509 } 510 511 static int 512 verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib) 513 { 514 struct route_in6 ro; 515 struct sockaddr_in6 *dst; 516 517 bzero(&ro, sizeof(ro)); 518 519 dst = (struct sockaddr_in6 * )&(ro.ro_dst); 520 dst->sin6_family = AF_INET6; 521 dst->sin6_len = sizeof(*dst); 522 dst->sin6_addr = *src; 523 524 in6_rtalloc_ign(&ro, 0, fib); 525 if (ro.ro_rt == NULL) 526 return 0; 527 528 /* 529 * if ifp is provided, check for equality with rtentry 530 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 531 * to support the case of sending packets to an address of our own. 532 * (where the former interface is the first argument of if_simloop() 533 * (=ifp), the latter is lo0) 534 */ 535 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 536 RTFREE(ro.ro_rt); 537 return 0; 538 } 539 540 /* if no ifp provided, check if rtentry is not default route */ 541 if (ifp == NULL && 542 IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) { 543 RTFREE(ro.ro_rt); 544 return 0; 545 } 546 547 /* or if this is a blackhole/reject route */ 548 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 549 RTFREE(ro.ro_rt); 550 return 0; 551 } 552 553 /* found valid route */ 554 RTFREE(ro.ro_rt); 555 return 1; 556 557 } 558 559 static int 560 is_icmp6_query(int icmp6_type) 561 { 562 if ((icmp6_type <= ICMP6_MAXTYPE) && 563 (icmp6_type == ICMP6_ECHO_REQUEST || 564 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 565 icmp6_type == ICMP6_WRUREQUEST || 566 icmp6_type == ICMP6_FQDN_QUERY || 567 icmp6_type == ICMP6_NI_QUERY)) 568 return (1); 569 570 return (0); 571 } 572 573 static void 574 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 575 { 576 struct mbuf *m; 577 578 m = args->m; 579 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 580 struct tcphdr *tcp; 581 tcp = (struct tcphdr *)((char *)ip6 + hlen); 582 583 if ((tcp->th_flags & TH_RST) == 0) { 584 struct mbuf *m0; 585 m0 = ipfw_send_pkt(args->m, &(args->f_id), 586 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 587 tcp->th_flags | TH_RST); 588 if (m0 != NULL) 589 ip6_output(m0, NULL, NULL, 0, NULL, NULL, 590 NULL); 591 } 592 FREE_PKT(m); 593 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */ 594 #if 0 595 /* 596 * Unlike above, the mbufs need to line up with the ip6 hdr, 597 * as the contents are read. We need to m_adj() the 598 * needed amount. 599 * The mbuf will however be thrown away so we can adjust it. 600 * Remember we did an m_pullup on it already so we 601 * can make some assumptions about contiguousness. 602 */ 603 if (args->L3offset) 604 m_adj(m, args->L3offset); 605 #endif 606 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 607 } else 608 FREE_PKT(m); 609 610 args->m = NULL; 611 } 612 613 #endif /* INET6 */ 614 615 616 /* 617 * sends a reject message, consuming the mbuf passed as an argument. 618 */ 619 static void 620 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip) 621 { 622 623 #if 0 624 /* XXX When ip is not guaranteed to be at mtod() we will 625 * need to account for this */ 626 * The mbuf will however be thrown away so we can adjust it. 627 * Remember we did an m_pullup on it already so we 628 * can make some assumptions about contiguousness. 629 */ 630 if (args->L3offset) 631 m_adj(m, args->L3offset); 632 #endif 633 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */ 634 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 635 } else if (args->f_id.proto == IPPROTO_TCP) { 636 struct tcphdr *const tcp = 637 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 638 if ( (tcp->th_flags & TH_RST) == 0) { 639 struct mbuf *m; 640 m = ipfw_send_pkt(args->m, &(args->f_id), 641 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 642 tcp->th_flags | TH_RST); 643 if (m != NULL) 644 ip_output(m, NULL, NULL, 0, NULL, NULL); 645 } 646 FREE_PKT(args->m); 647 } else 648 FREE_PKT(args->m); 649 args->m = NULL; 650 } 651 652 /* 653 * Support for uid/gid/jail lookup. These tests are expensive 654 * (because we may need to look into the list of active sockets) 655 * so we cache the results. ugid_lookupp is 0 if we have not 656 * yet done a lookup, 1 if we succeeded, and -1 if we tried 657 * and failed. The function always returns the match value. 658 * We could actually spare the variable and use *uc, setting 659 * it to '(void *)check_uidgid if we have no info, NULL if 660 * we tried and failed, or any other value if successful. 661 */ 662 static int 663 check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp, 664 struct ucred **uc) 665 { 666 #ifndef __FreeBSD__ 667 /* XXX */ 668 return cred_check(insn, proto, oif, 669 dst_ip, dst_port, src_ip, src_port, 670 (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb); 671 #else /* FreeBSD */ 672 struct in_addr src_ip, dst_ip; 673 struct inpcbinfo *pi; 674 struct ipfw_flow_id *id; 675 struct inpcb *pcb, *inp; 676 struct ifnet *oif; 677 int lookupflags; 678 int match; 679 680 id = &args->f_id; 681 inp = args->inp; 682 oif = args->oif; 683 684 /* 685 * Check to see if the UDP or TCP stack supplied us with 686 * the PCB. If so, rather then holding a lock and looking 687 * up the PCB, we can use the one that was supplied. 688 */ 689 if (inp && *ugid_lookupp == 0) { 690 INP_LOCK_ASSERT(inp); 691 if (inp->inp_socket != NULL) { 692 *uc = crhold(inp->inp_cred); 693 *ugid_lookupp = 1; 694 } else 695 *ugid_lookupp = -1; 696 } 697 /* 698 * If we have already been here and the packet has no 699 * PCB entry associated with it, then we can safely 700 * assume that this is a no match. 701 */ 702 if (*ugid_lookupp == -1) 703 return (0); 704 if (id->proto == IPPROTO_TCP) { 705 lookupflags = 0; 706 pi = &V_tcbinfo; 707 } else if (id->proto == IPPROTO_UDP) { 708 lookupflags = INPLOOKUP_WILDCARD; 709 pi = &V_udbinfo; 710 } else 711 return 0; 712 lookupflags |= INPLOOKUP_RLOCKPCB; 713 match = 0; 714 if (*ugid_lookupp == 0) { 715 if (id->addr_type == 6) { 716 #ifdef INET6 717 if (oif == NULL) 718 pcb = in6_pcblookup_mbuf(pi, 719 &id->src_ip6, htons(id->src_port), 720 &id->dst_ip6, htons(id->dst_port), 721 lookupflags, oif, args->m); 722 else 723 pcb = in6_pcblookup_mbuf(pi, 724 &id->dst_ip6, htons(id->dst_port), 725 &id->src_ip6, htons(id->src_port), 726 lookupflags, oif, args->m); 727 #else 728 *ugid_lookupp = -1; 729 return (0); 730 #endif 731 } else { 732 src_ip.s_addr = htonl(id->src_ip); 733 dst_ip.s_addr = htonl(id->dst_ip); 734 if (oif == NULL) 735 pcb = in_pcblookup_mbuf(pi, 736 src_ip, htons(id->src_port), 737 dst_ip, htons(id->dst_port), 738 lookupflags, oif, args->m); 739 else 740 pcb = in_pcblookup_mbuf(pi, 741 dst_ip, htons(id->dst_port), 742 src_ip, htons(id->src_port), 743 lookupflags, oif, args->m); 744 } 745 if (pcb != NULL) { 746 INP_RLOCK_ASSERT(pcb); 747 *uc = crhold(pcb->inp_cred); 748 *ugid_lookupp = 1; 749 INP_RUNLOCK(pcb); 750 } 751 if (*ugid_lookupp == 0) { 752 /* 753 * We tried and failed, set the variable to -1 754 * so we will not try again on this packet. 755 */ 756 *ugid_lookupp = -1; 757 return (0); 758 } 759 } 760 if (insn->o.opcode == O_UID) 761 match = ((*uc)->cr_uid == (uid_t)insn->d[0]); 762 else if (insn->o.opcode == O_GID) 763 match = groupmember((gid_t)insn->d[0], *uc); 764 else if (insn->o.opcode == O_JAIL) 765 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]); 766 return (match); 767 #endif /* __FreeBSD__ */ 768 } 769 770 /* 771 * Helper function to set args with info on the rule after the matching 772 * one. slot is precise, whereas we guess rule_id as they are 773 * assigned sequentially. 774 */ 775 static inline void 776 set_match(struct ip_fw_args *args, int slot, 777 struct ip_fw_chain *chain) 778 { 779 args->rule.chain_id = chain->id; 780 args->rule.slot = slot + 1; /* we use 0 as a marker */ 781 args->rule.rule_id = 1 + chain->map[slot]->id; 782 args->rule.rulenum = chain->map[slot]->rulenum; 783 } 784 785 /* 786 * Helper function to enable cached rule lookups using 787 * x_next and next_rule fields in ipfw rule. 788 */ 789 static int 790 jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 791 int tablearg, int jump_backwards) 792 { 793 int f_pos; 794 795 /* If possible use cached f_pos (in f->next_rule), 796 * whose version is written in f->next_rule 797 * (horrible hacks to avoid changing the ABI). 798 */ 799 if (num != IP_FW_TABLEARG && (uintptr_t)f->x_next == chain->id) 800 f_pos = (uintptr_t)f->next_rule; 801 else { 802 int i = IP_FW_ARG_TABLEARG(num); 803 /* make sure we do not jump backward */ 804 if (jump_backwards == 0 && i <= f->rulenum) 805 i = f->rulenum + 1; 806 f_pos = ipfw_find_rule(chain, i, 0); 807 /* update the cache */ 808 if (num != IP_FW_TABLEARG) { 809 f->next_rule = (void *)(uintptr_t)f_pos; 810 f->x_next = (void *)(uintptr_t)chain->id; 811 } 812 } 813 814 return (f_pos); 815 } 816 817 /* 818 * The main check routine for the firewall. 819 * 820 * All arguments are in args so we can modify them and return them 821 * back to the caller. 822 * 823 * Parameters: 824 * 825 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 826 * Starts with the IP header. 827 * args->eh (in) Mac header if present, NULL for layer3 packet. 828 * args->L3offset Number of bytes bypassed if we came from L2. 829 * e.g. often sizeof(eh) ** NOTYET ** 830 * args->oif Outgoing interface, NULL if packet is incoming. 831 * The incoming interface is in the mbuf. (in) 832 * args->divert_rule (in/out) 833 * Skip up to the first rule past this rule number; 834 * upon return, non-zero port number for divert or tee. 835 * 836 * args->rule Pointer to the last matching rule (in/out) 837 * args->next_hop Socket we are forwarding to (out). 838 * args->next_hop6 IPv6 next hop we are forwarding to (out). 839 * args->f_id Addresses grabbed from the packet (out) 840 * args->rule.info a cookie depending on rule action 841 * 842 * Return value: 843 * 844 * IP_FW_PASS the packet must be accepted 845 * IP_FW_DENY the packet must be dropped 846 * IP_FW_DIVERT divert packet, port in m_tag 847 * IP_FW_TEE tee packet, port in m_tag 848 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 849 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 850 * args->rule contains the matching rule, 851 * args->rule.info has additional information. 852 * 853 */ 854 int 855 ipfw_chk(struct ip_fw_args *args) 856 { 857 858 /* 859 * Local variables holding state while processing a packet: 860 * 861 * IMPORTANT NOTE: to speed up the processing of rules, there 862 * are some assumption on the values of the variables, which 863 * are documented here. Should you change them, please check 864 * the implementation of the various instructions to make sure 865 * that they still work. 866 * 867 * args->eh The MAC header. It is non-null for a layer2 868 * packet, it is NULL for a layer-3 packet. 869 * **notyet** 870 * args->L3offset Offset in the packet to the L3 (IP or equiv.) header. 871 * 872 * m | args->m Pointer to the mbuf, as received from the caller. 873 * It may change if ipfw_chk() does an m_pullup, or if it 874 * consumes the packet because it calls send_reject(). 875 * XXX This has to change, so that ipfw_chk() never modifies 876 * or consumes the buffer. 877 * ip is the beginning of the ip(4 or 6) header. 878 * Calculated by adding the L3offset to the start of data. 879 * (Until we start using L3offset, the packet is 880 * supposed to start with the ip header). 881 */ 882 struct mbuf *m = args->m; 883 struct ip *ip = mtod(m, struct ip *); 884 885 /* 886 * For rules which contain uid/gid or jail constraints, cache 887 * a copy of the users credentials after the pcb lookup has been 888 * executed. This will speed up the processing of rules with 889 * these types of constraints, as well as decrease contention 890 * on pcb related locks. 891 */ 892 #ifndef __FreeBSD__ 893 struct bsd_ucred ucred_cache; 894 #else 895 struct ucred *ucred_cache = NULL; 896 #endif 897 int ucred_lookup = 0; 898 899 /* 900 * oif | args->oif If NULL, ipfw_chk has been called on the 901 * inbound path (ether_input, ip_input). 902 * If non-NULL, ipfw_chk has been called on the outbound path 903 * (ether_output, ip_output). 904 */ 905 struct ifnet *oif = args->oif; 906 907 int f_pos = 0; /* index of current rule in the array */ 908 int retval = 0; 909 910 /* 911 * hlen The length of the IP header. 912 */ 913 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 914 915 /* 916 * offset The offset of a fragment. offset != 0 means that 917 * we have a fragment at this offset of an IPv4 packet. 918 * offset == 0 means that (if this is an IPv4 packet) 919 * this is the first or only fragment. 920 * For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header 921 * or there is a single packet fragement (fragement header added 922 * without needed). We will treat a single packet fragment as if 923 * there was no fragment header (or log/block depending on the 924 * V_fw_permit_single_frag6 sysctl setting). 925 */ 926 u_short offset = 0; 927 u_short ip6f_mf = 0; 928 929 /* 930 * Local copies of addresses. They are only valid if we have 931 * an IP packet. 932 * 933 * proto The protocol. Set to 0 for non-ip packets, 934 * or to the protocol read from the packet otherwise. 935 * proto != 0 means that we have an IPv4 packet. 936 * 937 * src_port, dst_port port numbers, in HOST format. Only 938 * valid for TCP and UDP packets. 939 * 940 * src_ip, dst_ip ip addresses, in NETWORK format. 941 * Only valid for IPv4 packets. 942 */ 943 uint8_t proto; 944 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 945 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 946 uint16_t iplen=0; 947 int pktlen; 948 uint16_t etype = 0; /* Host order stored ether type */ 949 950 /* 951 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 952 * MATCH_NONE when checked and not matched (q = NULL), 953 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) 954 */ 955 int dyn_dir = MATCH_UNKNOWN; 956 ipfw_dyn_rule *q = NULL; 957 struct ip_fw_chain *chain = &V_layer3_chain; 958 959 /* 960 * We store in ulp a pointer to the upper layer protocol header. 961 * In the ipv4 case this is easy to determine from the header, 962 * but for ipv6 we might have some additional headers in the middle. 963 * ulp is NULL if not found. 964 */ 965 void *ulp = NULL; /* upper layer protocol pointer. */ 966 967 /* XXX ipv6 variables */ 968 int is_ipv6 = 0; 969 uint8_t icmp6_type = 0; 970 uint16_t ext_hd = 0; /* bits vector for extension header filtering */ 971 /* end of ipv6 variables */ 972 973 int is_ipv4 = 0; 974 975 int done = 0; /* flag to exit the outer loop */ 976 977 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready)) 978 return (IP_FW_PASS); /* accept */ 979 980 dst_ip.s_addr = 0; /* make sure it is initialized */ 981 src_ip.s_addr = 0; /* make sure it is initialized */ 982 pktlen = m->m_pkthdr.len; 983 args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */ 984 proto = args->f_id.proto = 0; /* mark f_id invalid */ 985 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ 986 987 /* 988 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 989 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 990 * pointer might become stale after other pullups (but we never use it 991 * this way). 992 */ 993 #define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T)) 994 #define PULLUP_LEN(_len, p, T) \ 995 do { \ 996 int x = (_len) + T; \ 997 if ((m)->m_len < x) { \ 998 args->m = m = m_pullup(m, x); \ 999 if (m == NULL) \ 1000 goto pullup_failed; \ 1001 } \ 1002 p = (mtod(m, char *) + (_len)); \ 1003 } while (0) 1004 1005 /* 1006 * if we have an ether header, 1007 */ 1008 if (args->eh) 1009 etype = ntohs(args->eh->ether_type); 1010 1011 /* Identify IP packets and fill up variables. */ 1012 if (pktlen >= sizeof(struct ip6_hdr) && 1013 (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) { 1014 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 1015 is_ipv6 = 1; 1016 args->f_id.addr_type = 6; 1017 hlen = sizeof(struct ip6_hdr); 1018 proto = ip6->ip6_nxt; 1019 1020 /* Search extension headers to find upper layer protocols */ 1021 while (ulp == NULL && offset == 0) { 1022 switch (proto) { 1023 case IPPROTO_ICMPV6: 1024 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 1025 icmp6_type = ICMP6(ulp)->icmp6_type; 1026 break; 1027 1028 case IPPROTO_TCP: 1029 PULLUP_TO(hlen, ulp, struct tcphdr); 1030 dst_port = TCP(ulp)->th_dport; 1031 src_port = TCP(ulp)->th_sport; 1032 /* save flags for dynamic rules */ 1033 args->f_id._flags = TCP(ulp)->th_flags; 1034 break; 1035 1036 case IPPROTO_SCTP: 1037 PULLUP_TO(hlen, ulp, struct sctphdr); 1038 src_port = SCTP(ulp)->src_port; 1039 dst_port = SCTP(ulp)->dest_port; 1040 break; 1041 1042 case IPPROTO_UDP: 1043 PULLUP_TO(hlen, ulp, struct udphdr); 1044 dst_port = UDP(ulp)->uh_dport; 1045 src_port = UDP(ulp)->uh_sport; 1046 break; 1047 1048 case IPPROTO_HOPOPTS: /* RFC 2460 */ 1049 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1050 ext_hd |= EXT_HOPOPTS; 1051 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1052 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1053 ulp = NULL; 1054 break; 1055 1056 case IPPROTO_ROUTING: /* RFC 2460 */ 1057 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 1058 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 1059 case 0: 1060 ext_hd |= EXT_RTHDR0; 1061 break; 1062 case 2: 1063 ext_hd |= EXT_RTHDR2; 1064 break; 1065 default: 1066 if (V_fw_verbose) 1067 printf("IPFW2: IPV6 - Unknown " 1068 "Routing Header type(%d)\n", 1069 ((struct ip6_rthdr *) 1070 ulp)->ip6r_type); 1071 if (V_fw_deny_unknown_exthdrs) 1072 return (IP_FW_DENY); 1073 break; 1074 } 1075 ext_hd |= EXT_ROUTING; 1076 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 1077 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 1078 ulp = NULL; 1079 break; 1080 1081 case IPPROTO_FRAGMENT: /* RFC 2460 */ 1082 PULLUP_TO(hlen, ulp, struct ip6_frag); 1083 ext_hd |= EXT_FRAGMENT; 1084 hlen += sizeof (struct ip6_frag); 1085 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 1086 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 1087 IP6F_OFF_MASK; 1088 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg & 1089 IP6F_MORE_FRAG; 1090 if (V_fw_permit_single_frag6 == 0 && 1091 offset == 0 && ip6f_mf == 0) { 1092 if (V_fw_verbose) 1093 printf("IPFW2: IPV6 - Invalid " 1094 "Fragment Header\n"); 1095 if (V_fw_deny_unknown_exthdrs) 1096 return (IP_FW_DENY); 1097 break; 1098 } 1099 args->f_id.extra = 1100 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 1101 ulp = NULL; 1102 break; 1103 1104 case IPPROTO_DSTOPTS: /* RFC 2460 */ 1105 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1106 ext_hd |= EXT_DSTOPTS; 1107 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1108 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1109 ulp = NULL; 1110 break; 1111 1112 case IPPROTO_AH: /* RFC 2402 */ 1113 PULLUP_TO(hlen, ulp, struct ip6_ext); 1114 ext_hd |= EXT_AH; 1115 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 1116 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 1117 ulp = NULL; 1118 break; 1119 1120 case IPPROTO_ESP: /* RFC 2406 */ 1121 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 1122 /* Anything past Seq# is variable length and 1123 * data past this ext. header is encrypted. */ 1124 ext_hd |= EXT_ESP; 1125 break; 1126 1127 case IPPROTO_NONE: /* RFC 2460 */ 1128 /* 1129 * Packet ends here, and IPv6 header has 1130 * already been pulled up. If ip6e_len!=0 1131 * then octets must be ignored. 1132 */ 1133 ulp = ip; /* non-NULL to get out of loop. */ 1134 break; 1135 1136 case IPPROTO_OSPFIGP: 1137 /* XXX OSPF header check? */ 1138 PULLUP_TO(hlen, ulp, struct ip6_ext); 1139 break; 1140 1141 case IPPROTO_PIM: 1142 /* XXX PIM header check? */ 1143 PULLUP_TO(hlen, ulp, struct pim); 1144 break; 1145 1146 case IPPROTO_CARP: 1147 PULLUP_TO(hlen, ulp, struct carp_header); 1148 if (((struct carp_header *)ulp)->carp_version != 1149 CARP_VERSION) 1150 return (IP_FW_DENY); 1151 if (((struct carp_header *)ulp)->carp_type != 1152 CARP_ADVERTISEMENT) 1153 return (IP_FW_DENY); 1154 break; 1155 1156 case IPPROTO_IPV6: /* RFC 2893 */ 1157 PULLUP_TO(hlen, ulp, struct ip6_hdr); 1158 break; 1159 1160 case IPPROTO_IPV4: /* RFC 2893 */ 1161 PULLUP_TO(hlen, ulp, struct ip); 1162 break; 1163 1164 default: 1165 if (V_fw_verbose) 1166 printf("IPFW2: IPV6 - Unknown " 1167 "Extension Header(%d), ext_hd=%x\n", 1168 proto, ext_hd); 1169 if (V_fw_deny_unknown_exthdrs) 1170 return (IP_FW_DENY); 1171 PULLUP_TO(hlen, ulp, struct ip6_ext); 1172 break; 1173 } /*switch */ 1174 } 1175 ip = mtod(m, struct ip *); 1176 ip6 = (struct ip6_hdr *)ip; 1177 args->f_id.src_ip6 = ip6->ip6_src; 1178 args->f_id.dst_ip6 = ip6->ip6_dst; 1179 args->f_id.src_ip = 0; 1180 args->f_id.dst_ip = 0; 1181 args->f_id.flow_id6 = ntohl(ip6->ip6_flow); 1182 } else if (pktlen >= sizeof(struct ip) && 1183 (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) { 1184 is_ipv4 = 1; 1185 hlen = ip->ip_hl << 2; 1186 args->f_id.addr_type = 4; 1187 1188 /* 1189 * Collect parameters into local variables for faster matching. 1190 */ 1191 proto = ip->ip_p; 1192 src_ip = ip->ip_src; 1193 dst_ip = ip->ip_dst; 1194 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1195 iplen = ntohs(ip->ip_len); 1196 pktlen = iplen < pktlen ? iplen : pktlen; 1197 1198 if (offset == 0) { 1199 switch (proto) { 1200 case IPPROTO_TCP: 1201 PULLUP_TO(hlen, ulp, struct tcphdr); 1202 dst_port = TCP(ulp)->th_dport; 1203 src_port = TCP(ulp)->th_sport; 1204 /* save flags for dynamic rules */ 1205 args->f_id._flags = TCP(ulp)->th_flags; 1206 break; 1207 1208 case IPPROTO_SCTP: 1209 PULLUP_TO(hlen, ulp, struct sctphdr); 1210 src_port = SCTP(ulp)->src_port; 1211 dst_port = SCTP(ulp)->dest_port; 1212 break; 1213 1214 case IPPROTO_UDP: 1215 PULLUP_TO(hlen, ulp, struct udphdr); 1216 dst_port = UDP(ulp)->uh_dport; 1217 src_port = UDP(ulp)->uh_sport; 1218 break; 1219 1220 case IPPROTO_ICMP: 1221 PULLUP_TO(hlen, ulp, struct icmphdr); 1222 //args->f_id.flags = ICMP(ulp)->icmp_type; 1223 break; 1224 1225 default: 1226 break; 1227 } 1228 } 1229 1230 ip = mtod(m, struct ip *); 1231 args->f_id.src_ip = ntohl(src_ip.s_addr); 1232 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1233 } 1234 #undef PULLUP_TO 1235 if (proto) { /* we may have port numbers, store them */ 1236 args->f_id.proto = proto; 1237 args->f_id.src_port = src_port = ntohs(src_port); 1238 args->f_id.dst_port = dst_port = ntohs(dst_port); 1239 } 1240 1241 IPFW_PF_RLOCK(chain); 1242 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ 1243 IPFW_PF_RUNLOCK(chain); 1244 return (IP_FW_PASS); /* accept */ 1245 } 1246 if (args->rule.slot) { 1247 /* 1248 * Packet has already been tagged as a result of a previous 1249 * match on rule args->rule aka args->rule_id (PIPE, QUEUE, 1250 * REASS, NETGRAPH, DIVERT/TEE...) 1251 * Validate the slot and continue from the next one 1252 * if still present, otherwise do a lookup. 1253 */ 1254 f_pos = (args->rule.chain_id == chain->id) ? 1255 args->rule.slot : 1256 ipfw_find_rule(chain, args->rule.rulenum, 1257 args->rule.rule_id); 1258 } else { 1259 f_pos = 0; 1260 } 1261 1262 /* 1263 * Now scan the rules, and parse microinstructions for each rule. 1264 * We have two nested loops and an inner switch. Sometimes we 1265 * need to break out of one or both loops, or re-enter one of 1266 * the loops with updated variables. Loop variables are: 1267 * 1268 * f_pos (outer loop) points to the current rule. 1269 * On output it points to the matching rule. 1270 * done (outer loop) is used as a flag to break the loop. 1271 * l (inner loop) residual length of current rule. 1272 * cmd points to the current microinstruction. 1273 * 1274 * We break the inner loop by setting l=0 and possibly 1275 * cmdlen=0 if we don't want to advance cmd. 1276 * We break the outer loop by setting done=1 1277 * We can restart the inner loop by setting l>0 and f_pos, f, cmd 1278 * as needed. 1279 */ 1280 for (; f_pos < chain->n_rules; f_pos++) { 1281 ipfw_insn *cmd; 1282 uint32_t tablearg = 0; 1283 int l, cmdlen, skip_or; /* skip rest of OR block */ 1284 struct ip_fw *f; 1285 1286 f = chain->map[f_pos]; 1287 if (V_set_disable & (1 << f->set) ) 1288 continue; 1289 1290 skip_or = 0; 1291 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 1292 l -= cmdlen, cmd += cmdlen) { 1293 int match; 1294 1295 /* 1296 * check_body is a jump target used when we find a 1297 * CHECK_STATE, and need to jump to the body of 1298 * the target rule. 1299 */ 1300 1301 /* check_body: */ 1302 cmdlen = F_LEN(cmd); 1303 /* 1304 * An OR block (insn_1 || .. || insn_n) has the 1305 * F_OR bit set in all but the last instruction. 1306 * The first match will set "skip_or", and cause 1307 * the following instructions to be skipped until 1308 * past the one with the F_OR bit clear. 1309 */ 1310 if (skip_or) { /* skip this instruction */ 1311 if ((cmd->len & F_OR) == 0) 1312 skip_or = 0; /* next one is good */ 1313 continue; 1314 } 1315 match = 0; /* set to 1 if we succeed */ 1316 1317 switch (cmd->opcode) { 1318 /* 1319 * The first set of opcodes compares the packet's 1320 * fields with some pattern, setting 'match' if a 1321 * match is found. At the end of the loop there is 1322 * logic to deal with F_NOT and F_OR flags associated 1323 * with the opcode. 1324 */ 1325 case O_NOP: 1326 match = 1; 1327 break; 1328 1329 case O_FORWARD_MAC: 1330 printf("ipfw: opcode %d unimplemented\n", 1331 cmd->opcode); 1332 break; 1333 1334 case O_GID: 1335 case O_UID: 1336 case O_JAIL: 1337 /* 1338 * We only check offset == 0 && proto != 0, 1339 * as this ensures that we have a 1340 * packet with the ports info. 1341 */ 1342 if (offset != 0) 1343 break; 1344 if (proto == IPPROTO_TCP || 1345 proto == IPPROTO_UDP) 1346 match = check_uidgid( 1347 (ipfw_insn_u32 *)cmd, 1348 args, &ucred_lookup, 1349 #ifdef __FreeBSD__ 1350 &ucred_cache); 1351 #else 1352 (void *)&ucred_cache); 1353 #endif 1354 break; 1355 1356 case O_RECV: 1357 match = iface_match(m->m_pkthdr.rcvif, 1358 (ipfw_insn_if *)cmd, chain, &tablearg); 1359 break; 1360 1361 case O_XMIT: 1362 match = iface_match(oif, (ipfw_insn_if *)cmd, 1363 chain, &tablearg); 1364 break; 1365 1366 case O_VIA: 1367 match = iface_match(oif ? oif : 1368 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd, 1369 chain, &tablearg); 1370 break; 1371 1372 case O_MACADDR2: 1373 if (args->eh != NULL) { /* have MAC header */ 1374 u_int32_t *want = (u_int32_t *) 1375 ((ipfw_insn_mac *)cmd)->addr; 1376 u_int32_t *mask = (u_int32_t *) 1377 ((ipfw_insn_mac *)cmd)->mask; 1378 u_int32_t *hdr = (u_int32_t *)args->eh; 1379 1380 match = 1381 ( want[0] == (hdr[0] & mask[0]) && 1382 want[1] == (hdr[1] & mask[1]) && 1383 want[2] == (hdr[2] & mask[2]) ); 1384 } 1385 break; 1386 1387 case O_MAC_TYPE: 1388 if (args->eh != NULL) { 1389 u_int16_t *p = 1390 ((ipfw_insn_u16 *)cmd)->ports; 1391 int i; 1392 1393 for (i = cmdlen - 1; !match && i>0; 1394 i--, p += 2) 1395 match = (etype >= p[0] && 1396 etype <= p[1]); 1397 } 1398 break; 1399 1400 case O_FRAG: 1401 match = (offset != 0); 1402 break; 1403 1404 case O_IN: /* "out" is "not in" */ 1405 match = (oif == NULL); 1406 break; 1407 1408 case O_LAYER2: 1409 match = (args->eh != NULL); 1410 break; 1411 1412 case O_DIVERTED: 1413 { 1414 /* For diverted packets, args->rule.info 1415 * contains the divert port (in host format) 1416 * reason and direction. 1417 */ 1418 uint32_t i = args->rule.info; 1419 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT && 1420 cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2); 1421 } 1422 break; 1423 1424 case O_PROTO: 1425 /* 1426 * We do not allow an arg of 0 so the 1427 * check of "proto" only suffices. 1428 */ 1429 match = (proto == cmd->arg1); 1430 break; 1431 1432 case O_IP_SRC: 1433 match = is_ipv4 && 1434 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1435 src_ip.s_addr); 1436 break; 1437 1438 case O_IP_SRC_LOOKUP: 1439 case O_IP_DST_LOOKUP: 1440 if (is_ipv4) { 1441 uint32_t key = 1442 (cmd->opcode == O_IP_DST_LOOKUP) ? 1443 dst_ip.s_addr : src_ip.s_addr; 1444 uint32_t v = 0; 1445 1446 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { 1447 /* generic lookup. The key must be 1448 * in 32bit big-endian format. 1449 */ 1450 v = ((ipfw_insn_u32 *)cmd)->d[1]; 1451 if (v == 0) 1452 key = dst_ip.s_addr; 1453 else if (v == 1) 1454 key = src_ip.s_addr; 1455 else if (v == 6) /* dscp */ 1456 key = (ip->ip_tos >> 2) & 0x3f; 1457 else if (offset != 0) 1458 break; 1459 else if (proto != IPPROTO_TCP && 1460 proto != IPPROTO_UDP) 1461 break; 1462 else if (v == 2) 1463 key = htonl(dst_port); 1464 else if (v == 3) 1465 key = htonl(src_port); 1466 else if (v == 4 || v == 5) { 1467 check_uidgid( 1468 (ipfw_insn_u32 *)cmd, 1469 args, &ucred_lookup, 1470 #ifdef __FreeBSD__ 1471 &ucred_cache); 1472 if (v == 4 /* O_UID */) 1473 key = ucred_cache->cr_uid; 1474 else if (v == 5 /* O_JAIL */) 1475 key = ucred_cache->cr_prison->pr_id; 1476 #else /* !__FreeBSD__ */ 1477 (void *)&ucred_cache); 1478 if (v ==4 /* O_UID */) 1479 key = ucred_cache.uid; 1480 else if (v == 5 /* O_JAIL */) 1481 key = ucred_cache.xid; 1482 #endif /* !__FreeBSD__ */ 1483 key = htonl(key); 1484 } else 1485 break; 1486 } 1487 match = ipfw_lookup_table(chain, 1488 cmd->arg1, key, &v); 1489 if (!match) 1490 break; 1491 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1492 match = 1493 ((ipfw_insn_u32 *)cmd)->d[0] == v; 1494 else 1495 tablearg = v; 1496 } else if (is_ipv6) { 1497 uint32_t v = 0; 1498 void *pkey = (cmd->opcode == O_IP_DST_LOOKUP) ? 1499 &args->f_id.dst_ip6: &args->f_id.src_ip6; 1500 match = ipfw_lookup_table_extended(chain, 1501 cmd->arg1, pkey, &v, 1502 IPFW_TABLE_CIDR); 1503 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1504 match = ((ipfw_insn_u32 *)cmd)->d[0] == v; 1505 if (match) 1506 tablearg = v; 1507 } 1508 break; 1509 1510 case O_IP_SRC_MASK: 1511 case O_IP_DST_MASK: 1512 if (is_ipv4) { 1513 uint32_t a = 1514 (cmd->opcode == O_IP_DST_MASK) ? 1515 dst_ip.s_addr : src_ip.s_addr; 1516 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 1517 int i = cmdlen-1; 1518 1519 for (; !match && i>0; i-= 2, p+= 2) 1520 match = (p[0] == (a & p[1])); 1521 } 1522 break; 1523 1524 case O_IP_SRC_ME: 1525 if (is_ipv4) { 1526 struct ifnet *tif; 1527 1528 INADDR_TO_IFP(src_ip, tif); 1529 match = (tif != NULL); 1530 break; 1531 } 1532 #ifdef INET6 1533 /* FALLTHROUGH */ 1534 case O_IP6_SRC_ME: 1535 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6); 1536 #endif 1537 break; 1538 1539 case O_IP_DST_SET: 1540 case O_IP_SRC_SET: 1541 if (is_ipv4) { 1542 u_int32_t *d = (u_int32_t *)(cmd+1); 1543 u_int32_t addr = 1544 cmd->opcode == O_IP_DST_SET ? 1545 args->f_id.dst_ip : 1546 args->f_id.src_ip; 1547 1548 if (addr < d[0]) 1549 break; 1550 addr -= d[0]; /* subtract base */ 1551 match = (addr < cmd->arg1) && 1552 ( d[ 1 + (addr>>5)] & 1553 (1<<(addr & 0x1f)) ); 1554 } 1555 break; 1556 1557 case O_IP_DST: 1558 match = is_ipv4 && 1559 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1560 dst_ip.s_addr); 1561 break; 1562 1563 case O_IP_DST_ME: 1564 if (is_ipv4) { 1565 struct ifnet *tif; 1566 1567 INADDR_TO_IFP(dst_ip, tif); 1568 match = (tif != NULL); 1569 break; 1570 } 1571 #ifdef INET6 1572 /* FALLTHROUGH */ 1573 case O_IP6_DST_ME: 1574 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6); 1575 #endif 1576 break; 1577 1578 1579 case O_IP_SRCPORT: 1580 case O_IP_DSTPORT: 1581 /* 1582 * offset == 0 && proto != 0 is enough 1583 * to guarantee that we have a 1584 * packet with port info. 1585 */ 1586 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP) 1587 && offset == 0) { 1588 u_int16_t x = 1589 (cmd->opcode == O_IP_SRCPORT) ? 1590 src_port : dst_port ; 1591 u_int16_t *p = 1592 ((ipfw_insn_u16 *)cmd)->ports; 1593 int i; 1594 1595 for (i = cmdlen - 1; !match && i>0; 1596 i--, p += 2) 1597 match = (x>=p[0] && x<=p[1]); 1598 } 1599 break; 1600 1601 case O_ICMPTYPE: 1602 match = (offset == 0 && proto==IPPROTO_ICMP && 1603 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 1604 break; 1605 1606 #ifdef INET6 1607 case O_ICMP6TYPE: 1608 match = is_ipv6 && offset == 0 && 1609 proto==IPPROTO_ICMPV6 && 1610 icmp6type_match( 1611 ICMP6(ulp)->icmp6_type, 1612 (ipfw_insn_u32 *)cmd); 1613 break; 1614 #endif /* INET6 */ 1615 1616 case O_IPOPT: 1617 match = (is_ipv4 && 1618 ipopts_match(ip, cmd) ); 1619 break; 1620 1621 case O_IPVER: 1622 match = (is_ipv4 && 1623 cmd->arg1 == ip->ip_v); 1624 break; 1625 1626 case O_IPID: 1627 case O_IPLEN: 1628 case O_IPTTL: 1629 if (is_ipv4) { /* only for IP packets */ 1630 uint16_t x; 1631 uint16_t *p; 1632 int i; 1633 1634 if (cmd->opcode == O_IPLEN) 1635 x = iplen; 1636 else if (cmd->opcode == O_IPTTL) 1637 x = ip->ip_ttl; 1638 else /* must be IPID */ 1639 x = ntohs(ip->ip_id); 1640 if (cmdlen == 1) { 1641 match = (cmd->arg1 == x); 1642 break; 1643 } 1644 /* otherwise we have ranges */ 1645 p = ((ipfw_insn_u16 *)cmd)->ports; 1646 i = cmdlen - 1; 1647 for (; !match && i>0; i--, p += 2) 1648 match = (x >= p[0] && x <= p[1]); 1649 } 1650 break; 1651 1652 case O_IPPRECEDENCE: 1653 match = (is_ipv4 && 1654 (cmd->arg1 == (ip->ip_tos & 0xe0)) ); 1655 break; 1656 1657 case O_IPTOS: 1658 match = (is_ipv4 && 1659 flags_match(cmd, ip->ip_tos)); 1660 break; 1661 1662 case O_DSCP: 1663 { 1664 uint32_t *p; 1665 uint16_t x; 1666 1667 p = ((ipfw_insn_u32 *)cmd)->d; 1668 1669 if (is_ipv4) 1670 x = ip->ip_tos >> 2; 1671 else if (is_ipv6) { 1672 uint8_t *v; 1673 v = &((struct ip6_hdr *)ip)->ip6_vfc; 1674 x = (*v & 0x0F) << 2; 1675 v++; 1676 x |= *v >> 6; 1677 } else 1678 break; 1679 1680 /* DSCP bitmask is stored as low_u32 high_u32 */ 1681 if (x > 32) 1682 match = *(p + 1) & (1 << (x - 32)); 1683 else 1684 match = *p & (1 << x); 1685 } 1686 break; 1687 1688 case O_TCPDATALEN: 1689 if (proto == IPPROTO_TCP && offset == 0) { 1690 struct tcphdr *tcp; 1691 uint16_t x; 1692 uint16_t *p; 1693 int i; 1694 1695 tcp = TCP(ulp); 1696 x = iplen - 1697 ((ip->ip_hl + tcp->th_off) << 2); 1698 if (cmdlen == 1) { 1699 match = (cmd->arg1 == x); 1700 break; 1701 } 1702 /* otherwise we have ranges */ 1703 p = ((ipfw_insn_u16 *)cmd)->ports; 1704 i = cmdlen - 1; 1705 for (; !match && i>0; i--, p += 2) 1706 match = (x >= p[0] && x <= p[1]); 1707 } 1708 break; 1709 1710 case O_TCPFLAGS: 1711 match = (proto == IPPROTO_TCP && offset == 0 && 1712 flags_match(cmd, TCP(ulp)->th_flags)); 1713 break; 1714 1715 case O_TCPOPTS: 1716 PULLUP_LEN(hlen, ulp, (TCP(ulp)->th_off << 2)); 1717 match = (proto == IPPROTO_TCP && offset == 0 && 1718 tcpopts_match(TCP(ulp), cmd)); 1719 break; 1720 1721 case O_TCPSEQ: 1722 match = (proto == IPPROTO_TCP && offset == 0 && 1723 ((ipfw_insn_u32 *)cmd)->d[0] == 1724 TCP(ulp)->th_seq); 1725 break; 1726 1727 case O_TCPACK: 1728 match = (proto == IPPROTO_TCP && offset == 0 && 1729 ((ipfw_insn_u32 *)cmd)->d[0] == 1730 TCP(ulp)->th_ack); 1731 break; 1732 1733 case O_TCPWIN: 1734 if (proto == IPPROTO_TCP && offset == 0) { 1735 uint16_t x; 1736 uint16_t *p; 1737 int i; 1738 1739 x = ntohs(TCP(ulp)->th_win); 1740 if (cmdlen == 1) { 1741 match = (cmd->arg1 == x); 1742 break; 1743 } 1744 /* Otherwise we have ranges. */ 1745 p = ((ipfw_insn_u16 *)cmd)->ports; 1746 i = cmdlen - 1; 1747 for (; !match && i > 0; i--, p += 2) 1748 match = (x >= p[0] && x <= p[1]); 1749 } 1750 break; 1751 1752 case O_ESTAB: 1753 /* reject packets which have SYN only */ 1754 /* XXX should i also check for TH_ACK ? */ 1755 match = (proto == IPPROTO_TCP && offset == 0 && 1756 (TCP(ulp)->th_flags & 1757 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 1758 break; 1759 1760 case O_ALTQ: { 1761 struct pf_mtag *at; 1762 struct m_tag *mtag; 1763 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 1764 1765 /* 1766 * ALTQ uses mbuf tags from another 1767 * packet filtering system - pf(4). 1768 * We allocate a tag in its format 1769 * and fill it in, pretending to be pf(4). 1770 */ 1771 match = 1; 1772 at = pf_find_mtag(m); 1773 if (at != NULL && at->qid != 0) 1774 break; 1775 mtag = m_tag_get(PACKET_TAG_PF, 1776 sizeof(struct pf_mtag), M_NOWAIT | M_ZERO); 1777 if (mtag == NULL) { 1778 /* 1779 * Let the packet fall back to the 1780 * default ALTQ. 1781 */ 1782 break; 1783 } 1784 m_tag_prepend(m, mtag); 1785 at = (struct pf_mtag *)(mtag + 1); 1786 at->qid = altq->qid; 1787 at->hdr = ip; 1788 break; 1789 } 1790 1791 case O_LOG: 1792 ipfw_log(f, hlen, args, m, 1793 oif, offset | ip6f_mf, tablearg, ip); 1794 match = 1; 1795 break; 1796 1797 case O_PROB: 1798 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 1799 break; 1800 1801 case O_VERREVPATH: 1802 /* Outgoing packets automatically pass/match */ 1803 match = ((oif != NULL) || 1804 (m->m_pkthdr.rcvif == NULL) || 1805 ( 1806 #ifdef INET6 1807 is_ipv6 ? 1808 verify_path6(&(args->f_id.src_ip6), 1809 m->m_pkthdr.rcvif, args->f_id.fib) : 1810 #endif 1811 verify_path(src_ip, m->m_pkthdr.rcvif, 1812 args->f_id.fib))); 1813 break; 1814 1815 case O_VERSRCREACH: 1816 /* Outgoing packets automatically pass/match */ 1817 match = (hlen > 0 && ((oif != NULL) || 1818 #ifdef INET6 1819 is_ipv6 ? 1820 verify_path6(&(args->f_id.src_ip6), 1821 NULL, args->f_id.fib) : 1822 #endif 1823 verify_path(src_ip, NULL, args->f_id.fib))); 1824 break; 1825 1826 case O_ANTISPOOF: 1827 /* Outgoing packets automatically pass/match */ 1828 if (oif == NULL && hlen > 0 && 1829 ( (is_ipv4 && in_localaddr(src_ip)) 1830 #ifdef INET6 1831 || (is_ipv6 && 1832 in6_localaddr(&(args->f_id.src_ip6))) 1833 #endif 1834 )) 1835 match = 1836 #ifdef INET6 1837 is_ipv6 ? verify_path6( 1838 &(args->f_id.src_ip6), 1839 m->m_pkthdr.rcvif, 1840 args->f_id.fib) : 1841 #endif 1842 verify_path(src_ip, 1843 m->m_pkthdr.rcvif, 1844 args->f_id.fib); 1845 else 1846 match = 1; 1847 break; 1848 1849 case O_IPSEC: 1850 #ifdef IPSEC 1851 match = (m_tag_find(m, 1852 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 1853 #endif 1854 /* otherwise no match */ 1855 break; 1856 1857 #ifdef INET6 1858 case O_IP6_SRC: 1859 match = is_ipv6 && 1860 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 1861 &((ipfw_insn_ip6 *)cmd)->addr6); 1862 break; 1863 1864 case O_IP6_DST: 1865 match = is_ipv6 && 1866 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 1867 &((ipfw_insn_ip6 *)cmd)->addr6); 1868 break; 1869 case O_IP6_SRC_MASK: 1870 case O_IP6_DST_MASK: 1871 if (is_ipv6) { 1872 int i = cmdlen - 1; 1873 struct in6_addr p; 1874 struct in6_addr *d = 1875 &((ipfw_insn_ip6 *)cmd)->addr6; 1876 1877 for (; !match && i > 0; d += 2, 1878 i -= F_INSN_SIZE(struct in6_addr) 1879 * 2) { 1880 p = (cmd->opcode == 1881 O_IP6_SRC_MASK) ? 1882 args->f_id.src_ip6: 1883 args->f_id.dst_ip6; 1884 APPLY_MASK(&p, &d[1]); 1885 match = 1886 IN6_ARE_ADDR_EQUAL(&d[0], 1887 &p); 1888 } 1889 } 1890 break; 1891 1892 case O_FLOW6ID: 1893 match = is_ipv6 && 1894 flow6id_match(args->f_id.flow_id6, 1895 (ipfw_insn_u32 *) cmd); 1896 break; 1897 1898 case O_EXT_HDR: 1899 match = is_ipv6 && 1900 (ext_hd & ((ipfw_insn *) cmd)->arg1); 1901 break; 1902 1903 case O_IP6: 1904 match = is_ipv6; 1905 break; 1906 #endif 1907 1908 case O_IP4: 1909 match = is_ipv4; 1910 break; 1911 1912 case O_TAG: { 1913 struct m_tag *mtag; 1914 uint32_t tag = IP_FW_ARG_TABLEARG(cmd->arg1); 1915 1916 /* Packet is already tagged with this tag? */ 1917 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 1918 1919 /* We have `untag' action when F_NOT flag is 1920 * present. And we must remove this mtag from 1921 * mbuf and reset `match' to zero (`match' will 1922 * be inversed later). 1923 * Otherwise we should allocate new mtag and 1924 * push it into mbuf. 1925 */ 1926 if (cmd->len & F_NOT) { /* `untag' action */ 1927 if (mtag != NULL) 1928 m_tag_delete(m, mtag); 1929 match = 0; 1930 } else { 1931 if (mtag == NULL) { 1932 mtag = m_tag_alloc( MTAG_IPFW, 1933 tag, 0, M_NOWAIT); 1934 if (mtag != NULL) 1935 m_tag_prepend(m, mtag); 1936 } 1937 match = 1; 1938 } 1939 break; 1940 } 1941 1942 case O_FIB: /* try match the specified fib */ 1943 if (args->f_id.fib == cmd->arg1) 1944 match = 1; 1945 break; 1946 1947 case O_SOCKARG: { 1948 struct inpcb *inp = args->inp; 1949 struct inpcbinfo *pi; 1950 1951 if (is_ipv6) /* XXX can we remove this ? */ 1952 break; 1953 1954 if (proto == IPPROTO_TCP) 1955 pi = &V_tcbinfo; 1956 else if (proto == IPPROTO_UDP) 1957 pi = &V_udbinfo; 1958 else 1959 break; 1960 1961 /* 1962 * XXXRW: so_user_cookie should almost 1963 * certainly be inp_user_cookie? 1964 */ 1965 1966 /* For incomming packet, lookup up the 1967 inpcb using the src/dest ip/port tuple */ 1968 if (inp == NULL) { 1969 inp = in_pcblookup(pi, 1970 src_ip, htons(src_port), 1971 dst_ip, htons(dst_port), 1972 INPLOOKUP_RLOCKPCB, NULL); 1973 if (inp != NULL) { 1974 tablearg = 1975 inp->inp_socket->so_user_cookie; 1976 if (tablearg) 1977 match = 1; 1978 INP_RUNLOCK(inp); 1979 } 1980 } else { 1981 if (inp->inp_socket) { 1982 tablearg = 1983 inp->inp_socket->so_user_cookie; 1984 if (tablearg) 1985 match = 1; 1986 } 1987 } 1988 break; 1989 } 1990 1991 case O_TAGGED: { 1992 struct m_tag *mtag; 1993 uint32_t tag = IP_FW_ARG_TABLEARG(cmd->arg1); 1994 1995 if (cmdlen == 1) { 1996 match = m_tag_locate(m, MTAG_IPFW, 1997 tag, NULL) != NULL; 1998 break; 1999 } 2000 2001 /* we have ranges */ 2002 for (mtag = m_tag_first(m); 2003 mtag != NULL && !match; 2004 mtag = m_tag_next(m, mtag)) { 2005 uint16_t *p; 2006 int i; 2007 2008 if (mtag->m_tag_cookie != MTAG_IPFW) 2009 continue; 2010 2011 p = ((ipfw_insn_u16 *)cmd)->ports; 2012 i = cmdlen - 1; 2013 for(; !match && i > 0; i--, p += 2) 2014 match = 2015 mtag->m_tag_id >= p[0] && 2016 mtag->m_tag_id <= p[1]; 2017 } 2018 break; 2019 } 2020 2021 /* 2022 * The second set of opcodes represents 'actions', 2023 * i.e. the terminal part of a rule once the packet 2024 * matches all previous patterns. 2025 * Typically there is only one action for each rule, 2026 * and the opcode is stored at the end of the rule 2027 * (but there are exceptions -- see below). 2028 * 2029 * In general, here we set retval and terminate the 2030 * outer loop (would be a 'break 3' in some language, 2031 * but we need to set l=0, done=1) 2032 * 2033 * Exceptions: 2034 * O_COUNT and O_SKIPTO actions: 2035 * instead of terminating, we jump to the next rule 2036 * (setting l=0), or to the SKIPTO target (setting 2037 * f/f_len, cmd and l as needed), respectively. 2038 * 2039 * O_TAG, O_LOG and O_ALTQ action parameters: 2040 * perform some action and set match = 1; 2041 * 2042 * O_LIMIT and O_KEEP_STATE: these opcodes are 2043 * not real 'actions', and are stored right 2044 * before the 'action' part of the rule. 2045 * These opcodes try to install an entry in the 2046 * state tables; if successful, we continue with 2047 * the next opcode (match=1; break;), otherwise 2048 * the packet must be dropped (set retval, 2049 * break loops with l=0, done=1) 2050 * 2051 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2052 * cause a lookup of the state table, and a jump 2053 * to the 'action' part of the parent rule 2054 * if an entry is found, or 2055 * (CHECK_STATE only) a jump to the next rule if 2056 * the entry is not found. 2057 * The result of the lookup is cached so that 2058 * further instances of these opcodes become NOPs. 2059 * The jump to the next rule is done by setting 2060 * l=0, cmdlen=0. 2061 */ 2062 case O_LIMIT: 2063 case O_KEEP_STATE: 2064 if (ipfw_install_state(f, 2065 (ipfw_insn_limit *)cmd, args, tablearg)) { 2066 /* error or limit violation */ 2067 retval = IP_FW_DENY; 2068 l = 0; /* exit inner loop */ 2069 done = 1; /* exit outer loop */ 2070 } 2071 match = 1; 2072 break; 2073 2074 case O_PROBE_STATE: 2075 case O_CHECK_STATE: 2076 /* 2077 * dynamic rules are checked at the first 2078 * keep-state or check-state occurrence, 2079 * with the result being stored in dyn_dir. 2080 * The compiler introduces a PROBE_STATE 2081 * instruction for us when we have a 2082 * KEEP_STATE (because PROBE_STATE needs 2083 * to be run first). 2084 */ 2085 if (dyn_dir == MATCH_UNKNOWN && 2086 (q = ipfw_lookup_dyn_rule(&args->f_id, 2087 &dyn_dir, proto == IPPROTO_TCP ? 2088 TCP(ulp) : NULL)) 2089 != NULL) { 2090 /* 2091 * Found dynamic entry, update stats 2092 * and jump to the 'action' part of 2093 * the parent rule by setting 2094 * f, cmd, l and clearing cmdlen. 2095 */ 2096 IPFW_INC_DYN_COUNTER(q, pktlen); 2097 /* XXX we would like to have f_pos 2098 * readily accessible in the dynamic 2099 * rule, instead of having to 2100 * lookup q->rule. 2101 */ 2102 f = q->rule; 2103 f_pos = ipfw_find_rule(chain, 2104 f->rulenum, f->id); 2105 cmd = ACTION_PTR(f); 2106 l = f->cmd_len - f->act_ofs; 2107 ipfw_dyn_unlock(q); 2108 cmdlen = 0; 2109 match = 1; 2110 break; 2111 } 2112 /* 2113 * Dynamic entry not found. If CHECK_STATE, 2114 * skip to next rule, if PROBE_STATE just 2115 * ignore and continue with next opcode. 2116 */ 2117 if (cmd->opcode == O_CHECK_STATE) 2118 l = 0; /* exit inner loop */ 2119 match = 1; 2120 break; 2121 2122 case O_ACCEPT: 2123 retval = 0; /* accept */ 2124 l = 0; /* exit inner loop */ 2125 done = 1; /* exit outer loop */ 2126 break; 2127 2128 case O_PIPE: 2129 case O_QUEUE: 2130 set_match(args, f_pos, chain); 2131 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1); 2132 if (cmd->opcode == O_PIPE) 2133 args->rule.info |= IPFW_IS_PIPE; 2134 if (V_fw_one_pass) 2135 args->rule.info |= IPFW_ONEPASS; 2136 retval = IP_FW_DUMMYNET; 2137 l = 0; /* exit inner loop */ 2138 done = 1; /* exit outer loop */ 2139 break; 2140 2141 case O_DIVERT: 2142 case O_TEE: 2143 if (args->eh) /* not on layer 2 */ 2144 break; 2145 /* otherwise this is terminal */ 2146 l = 0; /* exit inner loop */ 2147 done = 1; /* exit outer loop */ 2148 retval = (cmd->opcode == O_DIVERT) ? 2149 IP_FW_DIVERT : IP_FW_TEE; 2150 set_match(args, f_pos, chain); 2151 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1); 2152 break; 2153 2154 case O_COUNT: 2155 IPFW_INC_RULE_COUNTER(f, pktlen); 2156 l = 0; /* exit inner loop */ 2157 break; 2158 2159 case O_SKIPTO: 2160 IPFW_INC_RULE_COUNTER(f, pktlen); 2161 f_pos = jump_fast(chain, f, cmd->arg1, tablearg, 0); 2162 /* 2163 * Skip disabled rules, and re-enter 2164 * the inner loop with the correct 2165 * f_pos, f, l and cmd. 2166 * Also clear cmdlen and skip_or 2167 */ 2168 for (; f_pos < chain->n_rules - 1 && 2169 (V_set_disable & 2170 (1 << chain->map[f_pos]->set)); 2171 f_pos++) 2172 ; 2173 /* Re-enter the inner loop at the skipto rule. */ 2174 f = chain->map[f_pos]; 2175 l = f->cmd_len; 2176 cmd = f->cmd; 2177 match = 1; 2178 cmdlen = 0; 2179 skip_or = 0; 2180 continue; 2181 break; /* not reached */ 2182 2183 case O_CALLRETURN: { 2184 /* 2185 * Implementation of `subroutine' call/return, 2186 * in the stack carried in an mbuf tag. This 2187 * is different from `skipto' in that any call 2188 * address is possible (`skipto' must prevent 2189 * backward jumps to avoid endless loops). 2190 * We have `return' action when F_NOT flag is 2191 * present. The `m_tag_id' field is used as 2192 * stack pointer. 2193 */ 2194 struct m_tag *mtag; 2195 uint16_t jmpto, *stack; 2196 2197 #define IS_CALL ((cmd->len & F_NOT) == 0) 2198 #define IS_RETURN ((cmd->len & F_NOT) != 0) 2199 /* 2200 * Hand-rolled version of m_tag_locate() with 2201 * wildcard `type'. 2202 * If not already tagged, allocate new tag. 2203 */ 2204 mtag = m_tag_first(m); 2205 while (mtag != NULL) { 2206 if (mtag->m_tag_cookie == 2207 MTAG_IPFW_CALL) 2208 break; 2209 mtag = m_tag_next(m, mtag); 2210 } 2211 if (mtag == NULL && IS_CALL) { 2212 mtag = m_tag_alloc(MTAG_IPFW_CALL, 0, 2213 IPFW_CALLSTACK_SIZE * 2214 sizeof(uint16_t), M_NOWAIT); 2215 if (mtag != NULL) 2216 m_tag_prepend(m, mtag); 2217 } 2218 2219 /* 2220 * On error both `call' and `return' just 2221 * continue with next rule. 2222 */ 2223 if (IS_RETURN && (mtag == NULL || 2224 mtag->m_tag_id == 0)) { 2225 l = 0; /* exit inner loop */ 2226 break; 2227 } 2228 if (IS_CALL && (mtag == NULL || 2229 mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) { 2230 printf("ipfw: call stack error, " 2231 "go to next rule\n"); 2232 l = 0; /* exit inner loop */ 2233 break; 2234 } 2235 2236 IPFW_INC_RULE_COUNTER(f, pktlen); 2237 stack = (uint16_t *)(mtag + 1); 2238 2239 /* 2240 * The `call' action may use cached f_pos 2241 * (in f->next_rule), whose version is written 2242 * in f->next_rule. 2243 * The `return' action, however, doesn't have 2244 * fixed jump address in cmd->arg1 and can't use 2245 * cache. 2246 */ 2247 if (IS_CALL) { 2248 stack[mtag->m_tag_id] = f->rulenum; 2249 mtag->m_tag_id++; 2250 f_pos = jump_fast(chain, f, cmd->arg1, 2251 tablearg, 1); 2252 } else { /* `return' action */ 2253 mtag->m_tag_id--; 2254 jmpto = stack[mtag->m_tag_id] + 1; 2255 f_pos = ipfw_find_rule(chain, jmpto, 0); 2256 } 2257 2258 /* 2259 * Skip disabled rules, and re-enter 2260 * the inner loop with the correct 2261 * f_pos, f, l and cmd. 2262 * Also clear cmdlen and skip_or 2263 */ 2264 for (; f_pos < chain->n_rules - 1 && 2265 (V_set_disable & 2266 (1 << chain->map[f_pos]->set)); f_pos++) 2267 ; 2268 /* Re-enter the inner loop at the dest rule. */ 2269 f = chain->map[f_pos]; 2270 l = f->cmd_len; 2271 cmd = f->cmd; 2272 cmdlen = 0; 2273 skip_or = 0; 2274 continue; 2275 break; /* NOTREACHED */ 2276 } 2277 #undef IS_CALL 2278 #undef IS_RETURN 2279 2280 case O_REJECT: 2281 /* 2282 * Drop the packet and send a reject notice 2283 * if the packet is not ICMP (or is an ICMP 2284 * query), and it is not multicast/broadcast. 2285 */ 2286 if (hlen > 0 && is_ipv4 && offset == 0 && 2287 (proto != IPPROTO_ICMP || 2288 is_icmp_query(ICMP(ulp))) && 2289 !(m->m_flags & (M_BCAST|M_MCAST)) && 2290 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 2291 send_reject(args, cmd->arg1, iplen, ip); 2292 m = args->m; 2293 } 2294 /* FALLTHROUGH */ 2295 #ifdef INET6 2296 case O_UNREACH6: 2297 if (hlen > 0 && is_ipv6 && 2298 ((offset & IP6F_OFF_MASK) == 0) && 2299 (proto != IPPROTO_ICMPV6 || 2300 (is_icmp6_query(icmp6_type) == 1)) && 2301 !(m->m_flags & (M_BCAST|M_MCAST)) && 2302 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 2303 send_reject6( 2304 args, cmd->arg1, hlen, 2305 (struct ip6_hdr *)ip); 2306 m = args->m; 2307 } 2308 /* FALLTHROUGH */ 2309 #endif 2310 case O_DENY: 2311 retval = IP_FW_DENY; 2312 l = 0; /* exit inner loop */ 2313 done = 1; /* exit outer loop */ 2314 break; 2315 2316 case O_FORWARD_IP: 2317 if (args->eh) /* not valid on layer2 pkts */ 2318 break; 2319 if (q == NULL || q->rule != f || 2320 dyn_dir == MATCH_FORWARD) { 2321 struct sockaddr_in *sa; 2322 sa = &(((ipfw_insn_sa *)cmd)->sa); 2323 if (sa->sin_addr.s_addr == INADDR_ANY) { 2324 bcopy(sa, &args->hopstore, 2325 sizeof(*sa)); 2326 args->hopstore.sin_addr.s_addr = 2327 htonl(tablearg); 2328 args->next_hop = &args->hopstore; 2329 } else { 2330 args->next_hop = sa; 2331 } 2332 } 2333 retval = IP_FW_PASS; 2334 l = 0; /* exit inner loop */ 2335 done = 1; /* exit outer loop */ 2336 break; 2337 2338 #ifdef INET6 2339 case O_FORWARD_IP6: 2340 if (args->eh) /* not valid on layer2 pkts */ 2341 break; 2342 if (q == NULL || q->rule != f || 2343 dyn_dir == MATCH_FORWARD) { 2344 struct sockaddr_in6 *sin6; 2345 2346 sin6 = &(((ipfw_insn_sa6 *)cmd)->sa); 2347 args->next_hop6 = sin6; 2348 } 2349 retval = IP_FW_PASS; 2350 l = 0; /* exit inner loop */ 2351 done = 1; /* exit outer loop */ 2352 break; 2353 #endif 2354 2355 case O_NETGRAPH: 2356 case O_NGTEE: 2357 set_match(args, f_pos, chain); 2358 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1); 2359 if (V_fw_one_pass) 2360 args->rule.info |= IPFW_ONEPASS; 2361 retval = (cmd->opcode == O_NETGRAPH) ? 2362 IP_FW_NETGRAPH : IP_FW_NGTEE; 2363 l = 0; /* exit inner loop */ 2364 done = 1; /* exit outer loop */ 2365 break; 2366 2367 case O_SETFIB: { 2368 uint32_t fib; 2369 2370 IPFW_INC_RULE_COUNTER(f, pktlen); 2371 fib = IP_FW_ARG_TABLEARG(cmd->arg1); 2372 if (fib >= rt_numfibs) 2373 fib = 0; 2374 M_SETFIB(m, fib); 2375 args->f_id.fib = fib; 2376 l = 0; /* exit inner loop */ 2377 break; 2378 } 2379 2380 case O_SETDSCP: { 2381 uint16_t code; 2382 2383 code = IP_FW_ARG_TABLEARG(cmd->arg1) & 0x3F; 2384 l = 0; /* exit inner loop */ 2385 if (is_ipv4) { 2386 uint16_t a; 2387 2388 a = ip->ip_tos; 2389 ip->ip_tos = (code << 2) | (ip->ip_tos & 0x03); 2390 a += ntohs(ip->ip_sum) - ip->ip_tos; 2391 ip->ip_sum = htons(a); 2392 } else if (is_ipv6) { 2393 uint8_t *v; 2394 2395 v = &((struct ip6_hdr *)ip)->ip6_vfc; 2396 *v = (*v & 0xF0) | (code >> 2); 2397 v++; 2398 *v = (*v & 0x3F) | ((code & 0x03) << 6); 2399 } else 2400 break; 2401 2402 IPFW_INC_RULE_COUNTER(f, pktlen); 2403 break; 2404 } 2405 2406 case O_NAT: 2407 l = 0; /* exit inner loop */ 2408 done = 1; /* exit outer loop */ 2409 if (!IPFW_NAT_LOADED) { 2410 retval = IP_FW_DENY; 2411 break; 2412 } 2413 2414 struct cfg_nat *t; 2415 int nat_id; 2416 2417 set_match(args, f_pos, chain); 2418 /* Check if this is 'global' nat rule */ 2419 if (cmd->arg1 == 0) { 2420 retval = ipfw_nat_ptr(args, NULL, m); 2421 break; 2422 } 2423 t = ((ipfw_insn_nat *)cmd)->nat; 2424 if (t == NULL) { 2425 nat_id = IP_FW_ARG_TABLEARG(cmd->arg1); 2426 t = (*lookup_nat_ptr)(&chain->nat, nat_id); 2427 2428 if (t == NULL) { 2429 retval = IP_FW_DENY; 2430 break; 2431 } 2432 if (cmd->arg1 != IP_FW_TABLEARG) 2433 ((ipfw_insn_nat *)cmd)->nat = t; 2434 } 2435 retval = ipfw_nat_ptr(args, t, m); 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->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 */
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