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/counter.h> 46 #include <sys/eventhandler.h> 47 #include <sys/malloc.h> 48 #include <sys/mbuf.h> 49 #include <sys/kernel.h> 50 #include <sys/lock.h> 51 #include <sys/jail.h> 52 #include <sys/module.h> 53 #include <sys/priv.h> 54 #include <sys/proc.h> 55 #include <sys/rwlock.h> 56 #include <sys/rmlock.h> 57 #include <sys/socket.h> 58 #include <sys/socketvar.h> 59 #include <sys/sysctl.h> 60 #include <sys/syslog.h> 61 #include <sys/ucred.h> 62 #include <net/ethernet.h> /* for ETHERTYPE_IP */ 63 #include <net/if.h> 64 #include <net/if_var.h> 65 #include <net/route.h> 66 #include <net/pfil.h> 67 #include <net/vnet.h> 68 69 #include <netpfil/pf/pf_mtag.h> 70 71 #include <netinet/in.h> 72 #include <netinet/in_var.h> 73 #include <netinet/in_pcb.h> 74 #include <netinet/ip.h> 75 #include <netinet/ip_var.h> 76 #include <netinet/ip_icmp.h> 77 #include <netinet/ip_fw.h> 78 #include <netinet/ip_carp.h> 79 #include <netinet/pim.h> 80 #include <netinet/tcp_var.h> 81 #include <netinet/udp.h> 82 #include <netinet/udp_var.h> 83 #include <netinet/sctp.h> 84 85 #include <netinet/ip6.h> 86 #include <netinet/icmp6.h> 87 #include <netinet/in_fib.h> 88 #ifdef INET6 89 #include <netinet6/in6_fib.h> 90 #include <netinet6/in6_pcb.h> 91 #include <netinet6/scope6_var.h> 92 #include <netinet6/ip6_var.h> 93 #endif 94 95 #include <netpfil/ipfw/ip_fw_private.h> 96 97 #include <machine/in_cksum.h> /* XXX for in_cksum */ 98 99 #ifdef MAC 100 #include <security/mac/mac_framework.h> 101 #endif 102 103 /* 104 * static variables followed by global ones. 105 * All ipfw global variables are here. 106 */ 107 108 static VNET_DEFINE(int, fw_deny_unknown_exthdrs); 109 #define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs) 110 111 static VNET_DEFINE(int, fw_permit_single_frag6) = 1; 112 #define V_fw_permit_single_frag6 VNET(fw_permit_single_frag6) 113 114 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 115 static int default_to_accept = 1; 116 #else 117 static int default_to_accept; 118 #endif 119 120 VNET_DEFINE(int, autoinc_step); 121 VNET_DEFINE(int, fw_one_pass) = 1; 122 123 VNET_DEFINE(unsigned int, fw_tables_max); 124 VNET_DEFINE(unsigned int, fw_tables_sets) = 0; /* Don't use set-aware tables */ 125 /* Use 128 tables by default */ 126 static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT; 127 128 #ifndef LINEAR_SKIPTO 129 static int jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 130 int tablearg, int jump_backwards); 131 #define JUMP(ch, f, num, targ, back) jump_fast(ch, f, num, targ, back) 132 #else 133 static int jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num, 134 int tablearg, int jump_backwards); 135 #define JUMP(ch, f, num, targ, back) jump_linear(ch, f, num, targ, back) 136 #endif 137 138 /* 139 * Each rule belongs to one of 32 different sets (0..31). 140 * The variable set_disable contains one bit per set. 141 * If the bit is set, all rules in the corresponding set 142 * are disabled. Set RESVD_SET(31) is reserved for the default rule 143 * and rules that are not deleted by the flush command, 144 * and CANNOT be disabled. 145 * Rules in set RESVD_SET can only be deleted individually. 146 */ 147 VNET_DEFINE(u_int32_t, set_disable); 148 #define V_set_disable VNET(set_disable) 149 150 VNET_DEFINE(int, fw_verbose); 151 /* counter for ipfw_log(NULL...) */ 152 VNET_DEFINE(u_int64_t, norule_counter); 153 VNET_DEFINE(int, verbose_limit); 154 155 /* layer3_chain contains the list of rules for layer 3 */ 156 VNET_DEFINE(struct ip_fw_chain, layer3_chain); 157 158 /* ipfw_vnet_ready controls when we are open for business */ 159 VNET_DEFINE(int, ipfw_vnet_ready) = 0; 160 161 VNET_DEFINE(int, ipfw_nat_ready) = 0; 162 163 ipfw_nat_t *ipfw_nat_ptr = NULL; 164 struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int); 165 ipfw_nat_cfg_t *ipfw_nat_cfg_ptr; 166 ipfw_nat_cfg_t *ipfw_nat_del_ptr; 167 ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr; 168 ipfw_nat_cfg_t *ipfw_nat_get_log_ptr; 169 170 #ifdef SYSCTL_NODE 171 uint32_t dummy_def = IPFW_DEFAULT_RULE; 172 static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS); 173 static int sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS); 174 175 SYSBEGIN(f3) 176 177 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 178 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 179 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0, 180 "Only do a single pass through ipfw when using dummynet(4)"); 181 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, 182 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(autoinc_step), 0, 183 "Rule number auto-increment step"); 184 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, 185 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0, 186 "Log matches to ipfw rules"); 187 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, 188 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(verbose_limit), 0, 189 "Set upper limit of matches of ipfw rules logged"); 190 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD, 191 &dummy_def, 0, 192 "The default/max possible rule number."); 193 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_max, 194 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, 0, 0, sysctl_ipfw_table_num, "IU", 195 "Maximum number of concurrently used tables"); 196 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_sets, 197 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, 198 0, 0, sysctl_ipfw_tables_sets, "IU", 199 "Use per-set namespace for tables"); 200 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN, 201 &default_to_accept, 0, 202 "Make the default rule accept all packets."); 203 TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables); 204 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, 205 CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0, 206 "Number of static rules"); 207 208 #ifdef INET6 209 SYSCTL_DECL(_net_inet6_ip6); 210 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 211 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs, 212 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE, 213 &VNET_NAME(fw_deny_unknown_exthdrs), 0, 214 "Deny packets with unknown IPv6 Extension Headers"); 215 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6, 216 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE, 217 &VNET_NAME(fw_permit_single_frag6), 0, 218 "Permit single packet IPv6 fragments"); 219 #endif /* INET6 */ 220 221 SYSEND 222 223 #endif /* SYSCTL_NODE */ 224 225 226 /* 227 * Some macros used in the various matching options. 228 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 229 * Other macros just cast void * into the appropriate type 230 */ 231 #define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 232 #define TCP(p) ((struct tcphdr *)(p)) 233 #define SCTP(p) ((struct sctphdr *)(p)) 234 #define UDP(p) ((struct udphdr *)(p)) 235 #define ICMP(p) ((struct icmphdr *)(p)) 236 #define ICMP6(p) ((struct icmp6_hdr *)(p)) 237 238 static __inline int 239 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 240 { 241 int type = icmp->icmp_type; 242 243 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 244 } 245 246 #define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 247 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 248 249 static int 250 is_icmp_query(struct icmphdr *icmp) 251 { 252 int type = icmp->icmp_type; 253 254 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 255 } 256 #undef TT 257 258 /* 259 * The following checks use two arrays of 8 or 16 bits to store the 260 * bits that we want set or clear, respectively. They are in the 261 * low and high half of cmd->arg1 or cmd->d[0]. 262 * 263 * We scan options and store the bits we find set. We succeed if 264 * 265 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 266 * 267 * The code is sometimes optimized not to store additional variables. 268 */ 269 270 static int 271 flags_match(ipfw_insn *cmd, u_int8_t bits) 272 { 273 u_char want_clear; 274 bits = ~bits; 275 276 if ( ((cmd->arg1 & 0xff) & bits) != 0) 277 return 0; /* some bits we want set were clear */ 278 want_clear = (cmd->arg1 >> 8) & 0xff; 279 if ( (want_clear & bits) != want_clear) 280 return 0; /* some bits we want clear were set */ 281 return 1; 282 } 283 284 static int 285 ipopts_match(struct ip *ip, ipfw_insn *cmd) 286 { 287 int optlen, bits = 0; 288 u_char *cp = (u_char *)(ip + 1); 289 int x = (ip->ip_hl << 2) - sizeof (struct ip); 290 291 for (; x > 0; x -= optlen, cp += optlen) { 292 int opt = cp[IPOPT_OPTVAL]; 293 294 if (opt == IPOPT_EOL) 295 break; 296 if (opt == IPOPT_NOP) 297 optlen = 1; 298 else { 299 optlen = cp[IPOPT_OLEN]; 300 if (optlen <= 0 || optlen > x) 301 return 0; /* invalid or truncated */ 302 } 303 switch (opt) { 304 305 default: 306 break; 307 308 case IPOPT_LSRR: 309 bits |= IP_FW_IPOPT_LSRR; 310 break; 311 312 case IPOPT_SSRR: 313 bits |= IP_FW_IPOPT_SSRR; 314 break; 315 316 case IPOPT_RR: 317 bits |= IP_FW_IPOPT_RR; 318 break; 319 320 case IPOPT_TS: 321 bits |= IP_FW_IPOPT_TS; 322 break; 323 } 324 } 325 return (flags_match(cmd, bits)); 326 } 327 328 static int 329 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 330 { 331 int optlen, bits = 0; 332 u_char *cp = (u_char *)(tcp + 1); 333 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 334 335 for (; x > 0; x -= optlen, cp += optlen) { 336 int opt = cp[0]; 337 if (opt == TCPOPT_EOL) 338 break; 339 if (opt == TCPOPT_NOP) 340 optlen = 1; 341 else { 342 optlen = cp[1]; 343 if (optlen <= 0) 344 break; 345 } 346 347 switch (opt) { 348 349 default: 350 break; 351 352 case TCPOPT_MAXSEG: 353 bits |= IP_FW_TCPOPT_MSS; 354 break; 355 356 case TCPOPT_WINDOW: 357 bits |= IP_FW_TCPOPT_WINDOW; 358 break; 359 360 case TCPOPT_SACK_PERMITTED: 361 case TCPOPT_SACK: 362 bits |= IP_FW_TCPOPT_SACK; 363 break; 364 365 case TCPOPT_TIMESTAMP: 366 bits |= IP_FW_TCPOPT_TS; 367 break; 368 369 } 370 } 371 return (flags_match(cmd, bits)); 372 } 373 374 static int 375 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain, 376 uint32_t *tablearg) 377 { 378 379 if (ifp == NULL) /* no iface with this packet, match fails */ 380 return (0); 381 382 /* Check by name or by IP address */ 383 if (cmd->name[0] != '\0') { /* match by name */ 384 if (cmd->name[0] == '\1') /* use tablearg to match */ 385 return ipfw_lookup_table_extended(chain, cmd->p.kidx, 0, 386 &ifp->if_index, tablearg); 387 /* Check name */ 388 if (cmd->p.glob) { 389 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 390 return(1); 391 } else { 392 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 393 return(1); 394 } 395 } else { 396 #if !defined(USERSPACE) && defined(__FreeBSD__) /* and OSX too ? */ 397 struct ifaddr *ia; 398 399 if_addr_rlock(ifp); 400 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 401 if (ia->ifa_addr->sa_family != AF_INET) 402 continue; 403 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 404 (ia->ifa_addr))->sin_addr.s_addr) { 405 if_addr_runlock(ifp); 406 return(1); /* match */ 407 } 408 } 409 if_addr_runlock(ifp); 410 #endif /* __FreeBSD__ */ 411 } 412 return(0); /* no match, fail ... */ 413 } 414 415 /* 416 * The verify_path function checks if a route to the src exists and 417 * if it is reachable via ifp (when provided). 418 * 419 * The 'verrevpath' option checks that the interface that an IP packet 420 * arrives on is the same interface that traffic destined for the 421 * packet's source address would be routed out of. 422 * The 'versrcreach' option just checks that the source address is 423 * reachable via any route (except default) in the routing table. 424 * These two are a measure to block forged packets. This is also 425 * commonly known as "anti-spoofing" or Unicast Reverse Path 426 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 427 * is purposely reminiscent of the Cisco IOS command, 428 * 429 * ip verify unicast reverse-path 430 * ip verify unicast source reachable-via any 431 * 432 * which implements the same functionality. But note that the syntax 433 * is misleading, and the check may be performed on all IP packets 434 * whether unicast, multicast, or broadcast. 435 */ 436 static int 437 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib) 438 { 439 #if defined(USERSPACE) || !defined(__FreeBSD__) 440 return 0; 441 #else 442 struct nhop4_basic nh4; 443 444 if (fib4_lookup_nh_basic(fib, src, NHR_IFAIF, 0, &nh4) != 0) 445 return (0); 446 447 /* 448 * If ifp is provided, check for equality with rtentry. 449 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 450 * in order to pass packets injected back by if_simloop(): 451 * routing entry (via lo0) for our own address 452 * may exist, so we need to handle routing assymetry. 453 */ 454 if (ifp != NULL && ifp != nh4.nh_ifp) 455 return (0); 456 457 /* if no ifp provided, check if rtentry is not default route */ 458 if (ifp == NULL && (nh4.nh_flags & NHF_DEFAULT) != 0) 459 return (0); 460 461 /* or if this is a blackhole/reject route */ 462 if (ifp == NULL && (nh4.nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0) 463 return (0); 464 465 /* found valid route */ 466 return 1; 467 #endif /* __FreeBSD__ */ 468 } 469 470 #ifdef INET6 471 /* 472 * ipv6 specific rules here... 473 */ 474 static __inline int 475 icmp6type_match (int type, ipfw_insn_u32 *cmd) 476 { 477 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 478 } 479 480 static int 481 flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 482 { 483 int i; 484 for (i=0; i <= cmd->o.arg1; ++i ) 485 if (curr_flow == cmd->d[i] ) 486 return 1; 487 return 0; 488 } 489 490 /* support for IP6_*_ME opcodes */ 491 static const struct in6_addr lla_mask = {{{ 492 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 493 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff 494 }}}; 495 496 static int 497 ipfw_localip6(struct in6_addr *in6) 498 { 499 struct rm_priotracker in6_ifa_tracker; 500 struct in6_ifaddr *ia; 501 502 if (IN6_IS_ADDR_MULTICAST(in6)) 503 return (0); 504 505 if (!IN6_IS_ADDR_LINKLOCAL(in6)) 506 return (in6_localip(in6)); 507 508 IN6_IFADDR_RLOCK(&in6_ifa_tracker); 509 TAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) { 510 if (!IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) 511 continue; 512 if (IN6_ARE_MASKED_ADDR_EQUAL(&ia->ia_addr.sin6_addr, 513 in6, &lla_mask)) { 514 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 515 return (1); 516 } 517 } 518 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 519 return (0); 520 } 521 522 static int 523 verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib) 524 { 525 struct nhop6_basic nh6; 526 527 if (IN6_IS_SCOPE_LINKLOCAL(src)) 528 return (1); 529 530 if (fib6_lookup_nh_basic(fib, src, 0, NHR_IFAIF, 0, &nh6) != 0) 531 return (0); 532 533 /* If ifp is provided, check for equality with route table. */ 534 if (ifp != NULL && ifp != nh6.nh_ifp) 535 return (0); 536 537 /* if no ifp provided, check if rtentry is not default route */ 538 if (ifp == NULL && (nh6.nh_flags & NHF_DEFAULT) != 0) 539 return (0); 540 541 /* or if this is a blackhole/reject route */ 542 if (ifp == NULL && (nh6.nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0) 543 return (0); 544 545 /* found valid route */ 546 return 1; 547 } 548 549 static int 550 is_icmp6_query(int icmp6_type) 551 { 552 if ((icmp6_type <= ICMP6_MAXTYPE) && 553 (icmp6_type == ICMP6_ECHO_REQUEST || 554 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 555 icmp6_type == ICMP6_WRUREQUEST || 556 icmp6_type == ICMP6_FQDN_QUERY || 557 icmp6_type == ICMP6_NI_QUERY)) 558 return (1); 559 560 return (0); 561 } 562 563 static void 564 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 565 { 566 struct mbuf *m; 567 568 m = args->m; 569 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 570 struct tcphdr *tcp; 571 tcp = (struct tcphdr *)((char *)ip6 + hlen); 572 573 if ((tcp->th_flags & TH_RST) == 0) { 574 struct mbuf *m0; 575 m0 = ipfw_send_pkt(args->m, &(args->f_id), 576 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 577 tcp->th_flags | TH_RST); 578 if (m0 != NULL) 579 ip6_output(m0, NULL, NULL, 0, NULL, NULL, 580 NULL); 581 } 582 FREE_PKT(m); 583 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */ 584 #if 0 585 /* 586 * Unlike above, the mbufs need to line up with the ip6 hdr, 587 * as the contents are read. We need to m_adj() the 588 * needed amount. 589 * The mbuf will however be thrown away so we can adjust it. 590 * Remember we did an m_pullup on it already so we 591 * can make some assumptions about contiguousness. 592 */ 593 if (args->L3offset) 594 m_adj(m, args->L3offset); 595 #endif 596 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 597 } else 598 FREE_PKT(m); 599 600 args->m = NULL; 601 } 602 603 #endif /* INET6 */ 604 605 606 /* 607 * sends a reject message, consuming the mbuf passed as an argument. 608 */ 609 static void 610 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip) 611 { 612 613 #if 0 614 /* XXX When ip is not guaranteed to be at mtod() we will 615 * need to account for this */ 616 * The mbuf will however be thrown away so we can adjust it. 617 * Remember we did an m_pullup on it already so we 618 * can make some assumptions about contiguousness. 619 */ 620 if (args->L3offset) 621 m_adj(m, args->L3offset); 622 #endif 623 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */ 624 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 625 } else if (args->f_id.proto == IPPROTO_TCP) { 626 struct tcphdr *const tcp = 627 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 628 if ( (tcp->th_flags & TH_RST) == 0) { 629 struct mbuf *m; 630 m = ipfw_send_pkt(args->m, &(args->f_id), 631 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 632 tcp->th_flags | TH_RST); 633 if (m != NULL) 634 ip_output(m, NULL, NULL, 0, NULL, NULL); 635 } 636 FREE_PKT(args->m); 637 } else 638 FREE_PKT(args->m); 639 args->m = NULL; 640 } 641 642 /* 643 * Support for uid/gid/jail lookup. These tests are expensive 644 * (because we may need to look into the list of active sockets) 645 * so we cache the results. ugid_lookupp is 0 if we have not 646 * yet done a lookup, 1 if we succeeded, and -1 if we tried 647 * and failed. The function always returns the match value. 648 * We could actually spare the variable and use *uc, setting 649 * it to '(void *)check_uidgid if we have no info, NULL if 650 * we tried and failed, or any other value if successful. 651 */ 652 static int 653 check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp, 654 struct ucred **uc) 655 { 656 #if defined(USERSPACE) 657 return 0; // not supported in userspace 658 #else 659 #ifndef __FreeBSD__ 660 /* XXX */ 661 return cred_check(insn, proto, oif, 662 dst_ip, dst_port, src_ip, src_port, 663 (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb); 664 #else /* FreeBSD */ 665 struct in_addr src_ip, dst_ip; 666 struct inpcbinfo *pi; 667 struct ipfw_flow_id *id; 668 struct inpcb *pcb, *inp; 669 struct ifnet *oif; 670 int lookupflags; 671 int match; 672 673 id = &args->f_id; 674 inp = args->inp; 675 oif = args->oif; 676 677 /* 678 * Check to see if the UDP or TCP stack supplied us with 679 * the PCB. If so, rather then holding a lock and looking 680 * up the PCB, we can use the one that was supplied. 681 */ 682 if (inp && *ugid_lookupp == 0) { 683 INP_LOCK_ASSERT(inp); 684 if (inp->inp_socket != NULL) { 685 *uc = crhold(inp->inp_cred); 686 *ugid_lookupp = 1; 687 } else 688 *ugid_lookupp = -1; 689 } 690 /* 691 * If we have already been here and the packet has no 692 * PCB entry associated with it, then we can safely 693 * assume that this is a no match. 694 */ 695 if (*ugid_lookupp == -1) 696 return (0); 697 if (id->proto == IPPROTO_TCP) { 698 lookupflags = 0; 699 pi = &V_tcbinfo; 700 } else if (id->proto == IPPROTO_UDP) { 701 lookupflags = INPLOOKUP_WILDCARD; 702 pi = &V_udbinfo; 703 } else 704 return 0; 705 lookupflags |= INPLOOKUP_RLOCKPCB; 706 match = 0; 707 if (*ugid_lookupp == 0) { 708 if (id->addr_type == 6) { 709 #ifdef INET6 710 if (oif == NULL) 711 pcb = in6_pcblookup_mbuf(pi, 712 &id->src_ip6, htons(id->src_port), 713 &id->dst_ip6, htons(id->dst_port), 714 lookupflags, oif, args->m); 715 else 716 pcb = in6_pcblookup_mbuf(pi, 717 &id->dst_ip6, htons(id->dst_port), 718 &id->src_ip6, htons(id->src_port), 719 lookupflags, oif, args->m); 720 #else 721 *ugid_lookupp = -1; 722 return (0); 723 #endif 724 } else { 725 src_ip.s_addr = htonl(id->src_ip); 726 dst_ip.s_addr = htonl(id->dst_ip); 727 if (oif == NULL) 728 pcb = in_pcblookup_mbuf(pi, 729 src_ip, htons(id->src_port), 730 dst_ip, htons(id->dst_port), 731 lookupflags, oif, args->m); 732 else 733 pcb = in_pcblookup_mbuf(pi, 734 dst_ip, htons(id->dst_port), 735 src_ip, htons(id->src_port), 736 lookupflags, oif, args->m); 737 } 738 if (pcb != NULL) { 739 INP_RLOCK_ASSERT(pcb); 740 *uc = crhold(pcb->inp_cred); 741 *ugid_lookupp = 1; 742 INP_RUNLOCK(pcb); 743 } 744 if (*ugid_lookupp == 0) { 745 /* 746 * We tried and failed, set the variable to -1 747 * so we will not try again on this packet. 748 */ 749 *ugid_lookupp = -1; 750 return (0); 751 } 752 } 753 if (insn->o.opcode == O_UID) 754 match = ((*uc)->cr_uid == (uid_t)insn->d[0]); 755 else if (insn->o.opcode == O_GID) 756 match = groupmember((gid_t)insn->d[0], *uc); 757 else if (insn->o.opcode == O_JAIL) 758 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]); 759 return (match); 760 #endif /* __FreeBSD__ */ 761 #endif /* not supported in userspace */ 762 } 763 764 /* 765 * Helper function to set args with info on the rule after the matching 766 * one. slot is precise, whereas we guess rule_id as they are 767 * assigned sequentially. 768 */ 769 static inline void 770 set_match(struct ip_fw_args *args, int slot, 771 struct ip_fw_chain *chain) 772 { 773 args->rule.chain_id = chain->id; 774 args->rule.slot = slot + 1; /* we use 0 as a marker */ 775 args->rule.rule_id = 1 + chain->map[slot]->id; 776 args->rule.rulenum = chain->map[slot]->rulenum; 777 } 778 779 #ifndef LINEAR_SKIPTO 780 /* 781 * Helper function to enable cached rule lookups using 782 * cached_id and cached_pos fields in ipfw rule. 783 */ 784 static int 785 jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 786 int tablearg, int jump_backwards) 787 { 788 int f_pos; 789 790 /* If possible use cached f_pos (in f->cached_pos), 791 * whose version is written in f->cached_id 792 * (horrible hacks to avoid changing the ABI). 793 */ 794 if (num != IP_FW_TARG && f->cached_id == chain->id) 795 f_pos = f->cached_pos; 796 else { 797 int i = IP_FW_ARG_TABLEARG(chain, num, skipto); 798 /* make sure we do not jump backward */ 799 if (jump_backwards == 0 && i <= f->rulenum) 800 i = f->rulenum + 1; 801 if (chain->idxmap != NULL) 802 f_pos = chain->idxmap[i]; 803 else 804 f_pos = ipfw_find_rule(chain, i, 0); 805 /* update the cache */ 806 if (num != IP_FW_TARG) { 807 f->cached_id = chain->id; 808 f->cached_pos = f_pos; 809 } 810 } 811 812 return (f_pos); 813 } 814 #else 815 /* 816 * Helper function to enable real fast rule lookups. 817 */ 818 static int 819 jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num, 820 int tablearg, int jump_backwards) 821 { 822 int f_pos; 823 824 num = IP_FW_ARG_TABLEARG(chain, num, skipto); 825 /* make sure we do not jump backward */ 826 if (jump_backwards == 0 && num <= f->rulenum) 827 num = f->rulenum + 1; 828 f_pos = chain->idxmap[num]; 829 830 return (f_pos); 831 } 832 #endif 833 834 #define TARG(k, f) IP_FW_ARG_TABLEARG(chain, k, f) 835 /* 836 * The main check routine for the firewall. 837 * 838 * All arguments are in args so we can modify them and return them 839 * back to the caller. 840 * 841 * Parameters: 842 * 843 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 844 * Starts with the IP header. 845 * args->eh (in) Mac header if present, NULL for layer3 packet. 846 * args->L3offset Number of bytes bypassed if we came from L2. 847 * e.g. often sizeof(eh) ** NOTYET ** 848 * args->oif Outgoing interface, NULL if packet is incoming. 849 * The incoming interface is in the mbuf. (in) 850 * args->divert_rule (in/out) 851 * Skip up to the first rule past this rule number; 852 * upon return, non-zero port number for divert or tee. 853 * 854 * args->rule Pointer to the last matching rule (in/out) 855 * args->next_hop Socket we are forwarding to (out). 856 * args->next_hop6 IPv6 next hop we are forwarding to (out). 857 * args->f_id Addresses grabbed from the packet (out) 858 * args->rule.info a cookie depending on rule action 859 * 860 * Return value: 861 * 862 * IP_FW_PASS the packet must be accepted 863 * IP_FW_DENY the packet must be dropped 864 * IP_FW_DIVERT divert packet, port in m_tag 865 * IP_FW_TEE tee packet, port in m_tag 866 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 867 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 868 * args->rule contains the matching rule, 869 * args->rule.info has additional information. 870 * 871 */ 872 int 873 ipfw_chk(struct ip_fw_args *args) 874 { 875 876 /* 877 * Local variables holding state while processing a packet: 878 * 879 * IMPORTANT NOTE: to speed up the processing of rules, there 880 * are some assumption on the values of the variables, which 881 * are documented here. Should you change them, please check 882 * the implementation of the various instructions to make sure 883 * that they still work. 884 * 885 * args->eh The MAC header. It is non-null for a layer2 886 * packet, it is NULL for a layer-3 packet. 887 * **notyet** 888 * args->L3offset Offset in the packet to the L3 (IP or equiv.) header. 889 * 890 * m | args->m Pointer to the mbuf, as received from the caller. 891 * It may change if ipfw_chk() does an m_pullup, or if it 892 * consumes the packet because it calls send_reject(). 893 * XXX This has to change, so that ipfw_chk() never modifies 894 * or consumes the buffer. 895 * ip is the beginning of the ip(4 or 6) header. 896 * Calculated by adding the L3offset to the start of data. 897 * (Until we start using L3offset, the packet is 898 * supposed to start with the ip header). 899 */ 900 struct mbuf *m = args->m; 901 struct ip *ip = mtod(m, struct ip *); 902 903 /* 904 * For rules which contain uid/gid or jail constraints, cache 905 * a copy of the users credentials after the pcb lookup has been 906 * executed. This will speed up the processing of rules with 907 * these types of constraints, as well as decrease contention 908 * on pcb related locks. 909 */ 910 #ifndef __FreeBSD__ 911 struct bsd_ucred ucred_cache; 912 #else 913 struct ucred *ucred_cache = NULL; 914 #endif 915 int ucred_lookup = 0; 916 917 /* 918 * oif | args->oif If NULL, ipfw_chk has been called on the 919 * inbound path (ether_input, ip_input). 920 * If non-NULL, ipfw_chk has been called on the outbound path 921 * (ether_output, ip_output). 922 */ 923 struct ifnet *oif = args->oif; 924 925 int f_pos = 0; /* index of current rule in the array */ 926 int retval = 0; 927 928 /* 929 * hlen The length of the IP header. 930 */ 931 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 932 933 /* 934 * offset The offset of a fragment. offset != 0 means that 935 * we have a fragment at this offset of an IPv4 packet. 936 * offset == 0 means that (if this is an IPv4 packet) 937 * this is the first or only fragment. 938 * For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header 939 * or there is a single packet fragment (fragment header added 940 * without needed). We will treat a single packet fragment as if 941 * there was no fragment header (or log/block depending on the 942 * V_fw_permit_single_frag6 sysctl setting). 943 */ 944 u_short offset = 0; 945 u_short ip6f_mf = 0; 946 947 /* 948 * Local copies of addresses. They are only valid if we have 949 * an IP packet. 950 * 951 * proto The protocol. Set to 0 for non-ip packets, 952 * or to the protocol read from the packet otherwise. 953 * proto != 0 means that we have an IPv4 packet. 954 * 955 * src_port, dst_port port numbers, in HOST format. Only 956 * valid for TCP and UDP packets. 957 * 958 * src_ip, dst_ip ip addresses, in NETWORK format. 959 * Only valid for IPv4 packets. 960 */ 961 uint8_t proto; 962 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 963 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 964 uint16_t iplen=0; 965 int pktlen; 966 uint16_t etype = 0; /* Host order stored ether type */ 967 968 /* 969 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 970 * MATCH_NONE when checked and not matched (q = NULL), 971 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) 972 */ 973 int dyn_dir = MATCH_UNKNOWN; 974 uint16_t dyn_name = 0; 975 ipfw_dyn_rule *q = NULL; 976 struct ip_fw_chain *chain = &V_layer3_chain; 977 978 /* 979 * We store in ulp a pointer to the upper layer protocol header. 980 * In the ipv4 case this is easy to determine from the header, 981 * but for ipv6 we might have some additional headers in the middle. 982 * ulp is NULL if not found. 983 */ 984 void *ulp = NULL; /* upper layer protocol pointer. */ 985 986 /* XXX ipv6 variables */ 987 int is_ipv6 = 0; 988 uint8_t icmp6_type = 0; 989 uint16_t ext_hd = 0; /* bits vector for extension header filtering */ 990 /* end of ipv6 variables */ 991 992 int is_ipv4 = 0; 993 994 int done = 0; /* flag to exit the outer loop */ 995 IPFW_RLOCK_TRACKER; 996 997 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready)) 998 return (IP_FW_PASS); /* accept */ 999 1000 dst_ip.s_addr = 0; /* make sure it is initialized */ 1001 src_ip.s_addr = 0; /* make sure it is initialized */ 1002 pktlen = m->m_pkthdr.len; 1003 args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */ 1004 proto = args->f_id.proto = 0; /* mark f_id invalid */ 1005 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ 1006 1007 /* 1008 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 1009 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 1010 * pointer might become stale after other pullups (but we never use it 1011 * this way). 1012 */ 1013 #define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T)) 1014 #define PULLUP_LEN(_len, p, T) \ 1015 do { \ 1016 int x = (_len) + T; \ 1017 if ((m)->m_len < x) { \ 1018 args->m = m = m_pullup(m, x); \ 1019 if (m == NULL) \ 1020 goto pullup_failed; \ 1021 } \ 1022 p = (mtod(m, char *) + (_len)); \ 1023 } while (0) 1024 1025 /* 1026 * if we have an ether header, 1027 */ 1028 if (args->eh) 1029 etype = ntohs(args->eh->ether_type); 1030 1031 /* Identify IP packets and fill up variables. */ 1032 if (pktlen >= sizeof(struct ip6_hdr) && 1033 (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) { 1034 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 1035 is_ipv6 = 1; 1036 args->f_id.addr_type = 6; 1037 hlen = sizeof(struct ip6_hdr); 1038 proto = ip6->ip6_nxt; 1039 1040 /* Search extension headers to find upper layer protocols */ 1041 while (ulp == NULL && offset == 0) { 1042 switch (proto) { 1043 case IPPROTO_ICMPV6: 1044 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 1045 icmp6_type = ICMP6(ulp)->icmp6_type; 1046 break; 1047 1048 case IPPROTO_TCP: 1049 PULLUP_TO(hlen, ulp, struct tcphdr); 1050 dst_port = TCP(ulp)->th_dport; 1051 src_port = TCP(ulp)->th_sport; 1052 /* save flags for dynamic rules */ 1053 args->f_id._flags = TCP(ulp)->th_flags; 1054 break; 1055 1056 case IPPROTO_SCTP: 1057 PULLUP_TO(hlen, ulp, struct sctphdr); 1058 src_port = SCTP(ulp)->src_port; 1059 dst_port = SCTP(ulp)->dest_port; 1060 break; 1061 1062 case IPPROTO_UDP: 1063 PULLUP_TO(hlen, ulp, struct udphdr); 1064 dst_port = UDP(ulp)->uh_dport; 1065 src_port = UDP(ulp)->uh_sport; 1066 break; 1067 1068 case IPPROTO_HOPOPTS: /* RFC 2460 */ 1069 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1070 ext_hd |= EXT_HOPOPTS; 1071 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1072 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1073 ulp = NULL; 1074 break; 1075 1076 case IPPROTO_ROUTING: /* RFC 2460 */ 1077 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 1078 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 1079 case 0: 1080 ext_hd |= EXT_RTHDR0; 1081 break; 1082 case 2: 1083 ext_hd |= EXT_RTHDR2; 1084 break; 1085 default: 1086 if (V_fw_verbose) 1087 printf("IPFW2: IPV6 - Unknown " 1088 "Routing Header type(%d)\n", 1089 ((struct ip6_rthdr *) 1090 ulp)->ip6r_type); 1091 if (V_fw_deny_unknown_exthdrs) 1092 return (IP_FW_DENY); 1093 break; 1094 } 1095 ext_hd |= EXT_ROUTING; 1096 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 1097 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 1098 ulp = NULL; 1099 break; 1100 1101 case IPPROTO_FRAGMENT: /* RFC 2460 */ 1102 PULLUP_TO(hlen, ulp, struct ip6_frag); 1103 ext_hd |= EXT_FRAGMENT; 1104 hlen += sizeof (struct ip6_frag); 1105 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 1106 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 1107 IP6F_OFF_MASK; 1108 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg & 1109 IP6F_MORE_FRAG; 1110 if (V_fw_permit_single_frag6 == 0 && 1111 offset == 0 && ip6f_mf == 0) { 1112 if (V_fw_verbose) 1113 printf("IPFW2: IPV6 - Invalid " 1114 "Fragment Header\n"); 1115 if (V_fw_deny_unknown_exthdrs) 1116 return (IP_FW_DENY); 1117 break; 1118 } 1119 args->f_id.extra = 1120 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 1121 ulp = NULL; 1122 break; 1123 1124 case IPPROTO_DSTOPTS: /* RFC 2460 */ 1125 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1126 ext_hd |= EXT_DSTOPTS; 1127 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1128 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1129 ulp = NULL; 1130 break; 1131 1132 case IPPROTO_AH: /* RFC 2402 */ 1133 PULLUP_TO(hlen, ulp, struct ip6_ext); 1134 ext_hd |= EXT_AH; 1135 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 1136 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 1137 ulp = NULL; 1138 break; 1139 1140 case IPPROTO_ESP: /* RFC 2406 */ 1141 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 1142 /* Anything past Seq# is variable length and 1143 * data past this ext. header is encrypted. */ 1144 ext_hd |= EXT_ESP; 1145 break; 1146 1147 case IPPROTO_NONE: /* RFC 2460 */ 1148 /* 1149 * Packet ends here, and IPv6 header has 1150 * already been pulled up. If ip6e_len!=0 1151 * then octets must be ignored. 1152 */ 1153 ulp = ip; /* non-NULL to get out of loop. */ 1154 break; 1155 1156 case IPPROTO_OSPFIGP: 1157 /* XXX OSPF header check? */ 1158 PULLUP_TO(hlen, ulp, struct ip6_ext); 1159 break; 1160 1161 case IPPROTO_PIM: 1162 /* XXX PIM header check? */ 1163 PULLUP_TO(hlen, ulp, struct pim); 1164 break; 1165 1166 case IPPROTO_CARP: 1167 PULLUP_TO(hlen, ulp, struct carp_header); 1168 if (((struct carp_header *)ulp)->carp_version != 1169 CARP_VERSION) 1170 return (IP_FW_DENY); 1171 if (((struct carp_header *)ulp)->carp_type != 1172 CARP_ADVERTISEMENT) 1173 return (IP_FW_DENY); 1174 break; 1175 1176 case IPPROTO_IPV6: /* RFC 2893 */ 1177 PULLUP_TO(hlen, ulp, struct ip6_hdr); 1178 break; 1179 1180 case IPPROTO_IPV4: /* RFC 2893 */ 1181 PULLUP_TO(hlen, ulp, struct ip); 1182 break; 1183 1184 default: 1185 if (V_fw_verbose) 1186 printf("IPFW2: IPV6 - Unknown " 1187 "Extension Header(%d), ext_hd=%x\n", 1188 proto, ext_hd); 1189 if (V_fw_deny_unknown_exthdrs) 1190 return (IP_FW_DENY); 1191 PULLUP_TO(hlen, ulp, struct ip6_ext); 1192 break; 1193 } /*switch */ 1194 } 1195 ip = mtod(m, struct ip *); 1196 ip6 = (struct ip6_hdr *)ip; 1197 args->f_id.src_ip6 = ip6->ip6_src; 1198 args->f_id.dst_ip6 = ip6->ip6_dst; 1199 args->f_id.src_ip = 0; 1200 args->f_id.dst_ip = 0; 1201 args->f_id.flow_id6 = ntohl(ip6->ip6_flow); 1202 } else if (pktlen >= sizeof(struct ip) && 1203 (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) { 1204 is_ipv4 = 1; 1205 hlen = ip->ip_hl << 2; 1206 args->f_id.addr_type = 4; 1207 1208 /* 1209 * Collect parameters into local variables for faster matching. 1210 */ 1211 proto = ip->ip_p; 1212 src_ip = ip->ip_src; 1213 dst_ip = ip->ip_dst; 1214 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1215 iplen = ntohs(ip->ip_len); 1216 pktlen = iplen < pktlen ? iplen : pktlen; 1217 1218 if (offset == 0) { 1219 switch (proto) { 1220 case IPPROTO_TCP: 1221 PULLUP_TO(hlen, ulp, struct tcphdr); 1222 dst_port = TCP(ulp)->th_dport; 1223 src_port = TCP(ulp)->th_sport; 1224 /* save flags for dynamic rules */ 1225 args->f_id._flags = TCP(ulp)->th_flags; 1226 break; 1227 1228 case IPPROTO_SCTP: 1229 PULLUP_TO(hlen, ulp, struct sctphdr); 1230 src_port = SCTP(ulp)->src_port; 1231 dst_port = SCTP(ulp)->dest_port; 1232 break; 1233 1234 case IPPROTO_UDP: 1235 PULLUP_TO(hlen, ulp, struct udphdr); 1236 dst_port = UDP(ulp)->uh_dport; 1237 src_port = UDP(ulp)->uh_sport; 1238 break; 1239 1240 case IPPROTO_ICMP: 1241 PULLUP_TO(hlen, ulp, struct icmphdr); 1242 //args->f_id.flags = ICMP(ulp)->icmp_type; 1243 break; 1244 1245 default: 1246 break; 1247 } 1248 } 1249 1250 ip = mtod(m, struct ip *); 1251 args->f_id.src_ip = ntohl(src_ip.s_addr); 1252 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1253 } 1254 #undef PULLUP_TO 1255 if (proto) { /* we may have port numbers, store them */ 1256 args->f_id.proto = proto; 1257 args->f_id.src_port = src_port = ntohs(src_port); 1258 args->f_id.dst_port = dst_port = ntohs(dst_port); 1259 } 1260 1261 IPFW_PF_RLOCK(chain); 1262 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ 1263 IPFW_PF_RUNLOCK(chain); 1264 return (IP_FW_PASS); /* accept */ 1265 } 1266 if (args->rule.slot) { 1267 /* 1268 * Packet has already been tagged as a result of a previous 1269 * match on rule args->rule aka args->rule_id (PIPE, QUEUE, 1270 * REASS, NETGRAPH, DIVERT/TEE...) 1271 * Validate the slot and continue from the next one 1272 * if still present, otherwise do a lookup. 1273 */ 1274 f_pos = (args->rule.chain_id == chain->id) ? 1275 args->rule.slot : 1276 ipfw_find_rule(chain, args->rule.rulenum, 1277 args->rule.rule_id); 1278 } else { 1279 f_pos = 0; 1280 } 1281 1282 /* 1283 * Now scan the rules, and parse microinstructions for each rule. 1284 * We have two nested loops and an inner switch. Sometimes we 1285 * need to break out of one or both loops, or re-enter one of 1286 * the loops with updated variables. Loop variables are: 1287 * 1288 * f_pos (outer loop) points to the current rule. 1289 * On output it points to the matching rule. 1290 * done (outer loop) is used as a flag to break the loop. 1291 * l (inner loop) residual length of current rule. 1292 * cmd points to the current microinstruction. 1293 * 1294 * We break the inner loop by setting l=0 and possibly 1295 * cmdlen=0 if we don't want to advance cmd. 1296 * We break the outer loop by setting done=1 1297 * We can restart the inner loop by setting l>0 and f_pos, f, cmd 1298 * as needed. 1299 */ 1300 for (; f_pos < chain->n_rules; f_pos++) { 1301 ipfw_insn *cmd; 1302 uint32_t tablearg = 0; 1303 int l, cmdlen, skip_or; /* skip rest of OR block */ 1304 struct ip_fw *f; 1305 1306 f = chain->map[f_pos]; 1307 if (V_set_disable & (1 << f->set) ) 1308 continue; 1309 1310 skip_or = 0; 1311 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 1312 l -= cmdlen, cmd += cmdlen) { 1313 int match; 1314 1315 /* 1316 * check_body is a jump target used when we find a 1317 * CHECK_STATE, and need to jump to the body of 1318 * the target rule. 1319 */ 1320 1321 /* check_body: */ 1322 cmdlen = F_LEN(cmd); 1323 /* 1324 * An OR block (insn_1 || .. || insn_n) has the 1325 * F_OR bit set in all but the last instruction. 1326 * The first match will set "skip_or", and cause 1327 * the following instructions to be skipped until 1328 * past the one with the F_OR bit clear. 1329 */ 1330 if (skip_or) { /* skip this instruction */ 1331 if ((cmd->len & F_OR) == 0) 1332 skip_or = 0; /* next one is good */ 1333 continue; 1334 } 1335 match = 0; /* set to 1 if we succeed */ 1336 1337 switch (cmd->opcode) { 1338 /* 1339 * The first set of opcodes compares the packet's 1340 * fields with some pattern, setting 'match' if a 1341 * match is found. At the end of the loop there is 1342 * logic to deal with F_NOT and F_OR flags associated 1343 * with the opcode. 1344 */ 1345 case O_NOP: 1346 match = 1; 1347 break; 1348 1349 case O_FORWARD_MAC: 1350 printf("ipfw: opcode %d unimplemented\n", 1351 cmd->opcode); 1352 break; 1353 1354 case O_GID: 1355 case O_UID: 1356 case O_JAIL: 1357 /* 1358 * We only check offset == 0 && proto != 0, 1359 * as this ensures that we have a 1360 * packet with the ports info. 1361 */ 1362 if (offset != 0) 1363 break; 1364 if (proto == IPPROTO_TCP || 1365 proto == IPPROTO_UDP) 1366 match = check_uidgid( 1367 (ipfw_insn_u32 *)cmd, 1368 args, &ucred_lookup, 1369 #ifdef __FreeBSD__ 1370 &ucred_cache); 1371 #else 1372 (void *)&ucred_cache); 1373 #endif 1374 break; 1375 1376 case O_RECV: 1377 match = iface_match(m->m_pkthdr.rcvif, 1378 (ipfw_insn_if *)cmd, chain, &tablearg); 1379 break; 1380 1381 case O_XMIT: 1382 match = iface_match(oif, (ipfw_insn_if *)cmd, 1383 chain, &tablearg); 1384 break; 1385 1386 case O_VIA: 1387 match = iface_match(oif ? oif : 1388 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd, 1389 chain, &tablearg); 1390 break; 1391 1392 case O_MACADDR2: 1393 if (args->eh != NULL) { /* have MAC header */ 1394 u_int32_t *want = (u_int32_t *) 1395 ((ipfw_insn_mac *)cmd)->addr; 1396 u_int32_t *mask = (u_int32_t *) 1397 ((ipfw_insn_mac *)cmd)->mask; 1398 u_int32_t *hdr = (u_int32_t *)args->eh; 1399 1400 match = 1401 ( want[0] == (hdr[0] & mask[0]) && 1402 want[1] == (hdr[1] & mask[1]) && 1403 want[2] == (hdr[2] & mask[2]) ); 1404 } 1405 break; 1406 1407 case O_MAC_TYPE: 1408 if (args->eh != NULL) { 1409 u_int16_t *p = 1410 ((ipfw_insn_u16 *)cmd)->ports; 1411 int i; 1412 1413 for (i = cmdlen - 1; !match && i>0; 1414 i--, p += 2) 1415 match = (etype >= p[0] && 1416 etype <= p[1]); 1417 } 1418 break; 1419 1420 case O_FRAG: 1421 match = (offset != 0); 1422 break; 1423 1424 case O_IN: /* "out" is "not in" */ 1425 match = (oif == NULL); 1426 break; 1427 1428 case O_LAYER2: 1429 match = (args->eh != NULL); 1430 break; 1431 1432 case O_DIVERTED: 1433 { 1434 /* For diverted packets, args->rule.info 1435 * contains the divert port (in host format) 1436 * reason and direction. 1437 */ 1438 uint32_t i = args->rule.info; 1439 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT && 1440 cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2); 1441 } 1442 break; 1443 1444 case O_PROTO: 1445 /* 1446 * We do not allow an arg of 0 so the 1447 * check of "proto" only suffices. 1448 */ 1449 match = (proto == cmd->arg1); 1450 break; 1451 1452 case O_IP_SRC: 1453 match = is_ipv4 && 1454 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1455 src_ip.s_addr); 1456 break; 1457 1458 case O_IP_SRC_LOOKUP: 1459 case O_IP_DST_LOOKUP: 1460 if (is_ipv4) { 1461 uint32_t key = 1462 (cmd->opcode == O_IP_DST_LOOKUP) ? 1463 dst_ip.s_addr : src_ip.s_addr; 1464 uint32_t v = 0; 1465 1466 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { 1467 /* generic lookup. The key must be 1468 * in 32bit big-endian format. 1469 */ 1470 v = ((ipfw_insn_u32 *)cmd)->d[1]; 1471 if (v == 0) 1472 key = dst_ip.s_addr; 1473 else if (v == 1) 1474 key = src_ip.s_addr; 1475 else if (v == 6) /* dscp */ 1476 key = (ip->ip_tos >> 2) & 0x3f; 1477 else if (offset != 0) 1478 break; 1479 else if (proto != IPPROTO_TCP && 1480 proto != IPPROTO_UDP) 1481 break; 1482 else if (v == 2) 1483 key = dst_port; 1484 else if (v == 3) 1485 key = src_port; 1486 #ifndef USERSPACE 1487 else if (v == 4 || v == 5) { 1488 check_uidgid( 1489 (ipfw_insn_u32 *)cmd, 1490 args, &ucred_lookup, 1491 #ifdef __FreeBSD__ 1492 &ucred_cache); 1493 if (v == 4 /* O_UID */) 1494 key = ucred_cache->cr_uid; 1495 else if (v == 5 /* O_JAIL */) 1496 key = ucred_cache->cr_prison->pr_id; 1497 #else /* !__FreeBSD__ */ 1498 (void *)&ucred_cache); 1499 if (v ==4 /* O_UID */) 1500 key = ucred_cache.uid; 1501 else if (v == 5 /* O_JAIL */) 1502 key = ucred_cache.xid; 1503 #endif /* !__FreeBSD__ */ 1504 } 1505 #endif /* !USERSPACE */ 1506 else 1507 break; 1508 } 1509 match = ipfw_lookup_table(chain, 1510 cmd->arg1, key, &v); 1511 if (!match) 1512 break; 1513 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1514 match = 1515 ((ipfw_insn_u32 *)cmd)->d[0] == v; 1516 else 1517 tablearg = v; 1518 } else if (is_ipv6) { 1519 uint32_t v = 0; 1520 void *pkey = (cmd->opcode == O_IP_DST_LOOKUP) ? 1521 &args->f_id.dst_ip6: &args->f_id.src_ip6; 1522 match = ipfw_lookup_table_extended(chain, 1523 cmd->arg1, 1524 sizeof(struct in6_addr), 1525 pkey, &v); 1526 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1527 match = ((ipfw_insn_u32 *)cmd)->d[0] == v; 1528 if (match) 1529 tablearg = v; 1530 } 1531 break; 1532 1533 case O_IP_FLOW_LOOKUP: 1534 { 1535 uint32_t v = 0; 1536 match = ipfw_lookup_table_extended(chain, 1537 cmd->arg1, 0, &args->f_id, &v); 1538 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1539 match = ((ipfw_insn_u32 *)cmd)->d[0] == v; 1540 if (match) 1541 tablearg = v; 1542 } 1543 break; 1544 case O_IP_SRC_MASK: 1545 case O_IP_DST_MASK: 1546 if (is_ipv4) { 1547 uint32_t a = 1548 (cmd->opcode == O_IP_DST_MASK) ? 1549 dst_ip.s_addr : src_ip.s_addr; 1550 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 1551 int i = cmdlen-1; 1552 1553 for (; !match && i>0; i-= 2, p+= 2) 1554 match = (p[0] == (a & p[1])); 1555 } 1556 break; 1557 1558 case O_IP_SRC_ME: 1559 if (is_ipv4) { 1560 struct ifnet *tif; 1561 1562 INADDR_TO_IFP(src_ip, tif); 1563 match = (tif != NULL); 1564 break; 1565 } 1566 #ifdef INET6 1567 /* FALLTHROUGH */ 1568 case O_IP6_SRC_ME: 1569 match= is_ipv6 && ipfw_localip6(&args->f_id.src_ip6); 1570 #endif 1571 break; 1572 1573 case O_IP_DST_SET: 1574 case O_IP_SRC_SET: 1575 if (is_ipv4) { 1576 u_int32_t *d = (u_int32_t *)(cmd+1); 1577 u_int32_t addr = 1578 cmd->opcode == O_IP_DST_SET ? 1579 args->f_id.dst_ip : 1580 args->f_id.src_ip; 1581 1582 if (addr < d[0]) 1583 break; 1584 addr -= d[0]; /* subtract base */ 1585 match = (addr < cmd->arg1) && 1586 ( d[ 1 + (addr>>5)] & 1587 (1<<(addr & 0x1f)) ); 1588 } 1589 break; 1590 1591 case O_IP_DST: 1592 match = is_ipv4 && 1593 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1594 dst_ip.s_addr); 1595 break; 1596 1597 case O_IP_DST_ME: 1598 if (is_ipv4) { 1599 struct ifnet *tif; 1600 1601 INADDR_TO_IFP(dst_ip, tif); 1602 match = (tif != NULL); 1603 break; 1604 } 1605 #ifdef INET6 1606 /* FALLTHROUGH */ 1607 case O_IP6_DST_ME: 1608 match= is_ipv6 && ipfw_localip6(&args->f_id.dst_ip6); 1609 #endif 1610 break; 1611 1612 1613 case O_IP_SRCPORT: 1614 case O_IP_DSTPORT: 1615 /* 1616 * offset == 0 && proto != 0 is enough 1617 * to guarantee that we have a 1618 * packet with port info. 1619 */ 1620 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP) 1621 && offset == 0) { 1622 u_int16_t x = 1623 (cmd->opcode == O_IP_SRCPORT) ? 1624 src_port : dst_port ; 1625 u_int16_t *p = 1626 ((ipfw_insn_u16 *)cmd)->ports; 1627 int i; 1628 1629 for (i = cmdlen - 1; !match && i>0; 1630 i--, p += 2) 1631 match = (x>=p[0] && x<=p[1]); 1632 } 1633 break; 1634 1635 case O_ICMPTYPE: 1636 match = (offset == 0 && proto==IPPROTO_ICMP && 1637 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 1638 break; 1639 1640 #ifdef INET6 1641 case O_ICMP6TYPE: 1642 match = is_ipv6 && offset == 0 && 1643 proto==IPPROTO_ICMPV6 && 1644 icmp6type_match( 1645 ICMP6(ulp)->icmp6_type, 1646 (ipfw_insn_u32 *)cmd); 1647 break; 1648 #endif /* INET6 */ 1649 1650 case O_IPOPT: 1651 match = (is_ipv4 && 1652 ipopts_match(ip, cmd) ); 1653 break; 1654 1655 case O_IPVER: 1656 match = (is_ipv4 && 1657 cmd->arg1 == ip->ip_v); 1658 break; 1659 1660 case O_IPID: 1661 case O_IPLEN: 1662 case O_IPTTL: 1663 if (is_ipv4) { /* only for IP packets */ 1664 uint16_t x; 1665 uint16_t *p; 1666 int i; 1667 1668 if (cmd->opcode == O_IPLEN) 1669 x = iplen; 1670 else if (cmd->opcode == O_IPTTL) 1671 x = ip->ip_ttl; 1672 else /* must be IPID */ 1673 x = ntohs(ip->ip_id); 1674 if (cmdlen == 1) { 1675 match = (cmd->arg1 == x); 1676 break; 1677 } 1678 /* otherwise we have ranges */ 1679 p = ((ipfw_insn_u16 *)cmd)->ports; 1680 i = cmdlen - 1; 1681 for (; !match && i>0; i--, p += 2) 1682 match = (x >= p[0] && x <= p[1]); 1683 } 1684 break; 1685 1686 case O_IPPRECEDENCE: 1687 match = (is_ipv4 && 1688 (cmd->arg1 == (ip->ip_tos & 0xe0)) ); 1689 break; 1690 1691 case O_IPTOS: 1692 match = (is_ipv4 && 1693 flags_match(cmd, ip->ip_tos)); 1694 break; 1695 1696 case O_DSCP: 1697 { 1698 uint32_t *p; 1699 uint16_t x; 1700 1701 p = ((ipfw_insn_u32 *)cmd)->d; 1702 1703 if (is_ipv4) 1704 x = ip->ip_tos >> 2; 1705 else if (is_ipv6) { 1706 uint8_t *v; 1707 v = &((struct ip6_hdr *)ip)->ip6_vfc; 1708 x = (*v & 0x0F) << 2; 1709 v++; 1710 x |= *v >> 6; 1711 } else 1712 break; 1713 1714 /* DSCP bitmask is stored as low_u32 high_u32 */ 1715 if (x >= 32) 1716 match = *(p + 1) & (1 << (x - 32)); 1717 else 1718 match = *p & (1 << x); 1719 } 1720 break; 1721 1722 case O_TCPDATALEN: 1723 if (proto == IPPROTO_TCP && offset == 0) { 1724 struct tcphdr *tcp; 1725 uint16_t x; 1726 uint16_t *p; 1727 int i; 1728 1729 tcp = TCP(ulp); 1730 x = iplen - 1731 ((ip->ip_hl + tcp->th_off) << 2); 1732 if (cmdlen == 1) { 1733 match = (cmd->arg1 == x); 1734 break; 1735 } 1736 /* otherwise we have ranges */ 1737 p = ((ipfw_insn_u16 *)cmd)->ports; 1738 i = cmdlen - 1; 1739 for (; !match && i>0; i--, p += 2) 1740 match = (x >= p[0] && x <= p[1]); 1741 } 1742 break; 1743 1744 case O_TCPFLAGS: 1745 match = (proto == IPPROTO_TCP && offset == 0 && 1746 flags_match(cmd, TCP(ulp)->th_flags)); 1747 break; 1748 1749 case O_TCPOPTS: 1750 if (proto == IPPROTO_TCP && offset == 0 && ulp){ 1751 PULLUP_LEN(hlen, ulp, 1752 (TCP(ulp)->th_off << 2)); 1753 match = tcpopts_match(TCP(ulp), cmd); 1754 } 1755 break; 1756 1757 case O_TCPSEQ: 1758 match = (proto == IPPROTO_TCP && offset == 0 && 1759 ((ipfw_insn_u32 *)cmd)->d[0] == 1760 TCP(ulp)->th_seq); 1761 break; 1762 1763 case O_TCPACK: 1764 match = (proto == IPPROTO_TCP && offset == 0 && 1765 ((ipfw_insn_u32 *)cmd)->d[0] == 1766 TCP(ulp)->th_ack); 1767 break; 1768 1769 case O_TCPWIN: 1770 if (proto == IPPROTO_TCP && offset == 0) { 1771 uint16_t x; 1772 uint16_t *p; 1773 int i; 1774 1775 x = ntohs(TCP(ulp)->th_win); 1776 if (cmdlen == 1) { 1777 match = (cmd->arg1 == x); 1778 break; 1779 } 1780 /* Otherwise we have ranges. */ 1781 p = ((ipfw_insn_u16 *)cmd)->ports; 1782 i = cmdlen - 1; 1783 for (; !match && i > 0; i--, p += 2) 1784 match = (x >= p[0] && x <= p[1]); 1785 } 1786 break; 1787 1788 case O_ESTAB: 1789 /* reject packets which have SYN only */ 1790 /* XXX should i also check for TH_ACK ? */ 1791 match = (proto == IPPROTO_TCP && offset == 0 && 1792 (TCP(ulp)->th_flags & 1793 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 1794 break; 1795 1796 case O_ALTQ: { 1797 struct pf_mtag *at; 1798 struct m_tag *mtag; 1799 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 1800 1801 /* 1802 * ALTQ uses mbuf tags from another 1803 * packet filtering system - pf(4). 1804 * We allocate a tag in its format 1805 * and fill it in, pretending to be pf(4). 1806 */ 1807 match = 1; 1808 at = pf_find_mtag(m); 1809 if (at != NULL && at->qid != 0) 1810 break; 1811 mtag = m_tag_get(PACKET_TAG_PF, 1812 sizeof(struct pf_mtag), M_NOWAIT | M_ZERO); 1813 if (mtag == NULL) { 1814 /* 1815 * Let the packet fall back to the 1816 * default ALTQ. 1817 */ 1818 break; 1819 } 1820 m_tag_prepend(m, mtag); 1821 at = (struct pf_mtag *)(mtag + 1); 1822 at->qid = altq->qid; 1823 at->hdr = ip; 1824 break; 1825 } 1826 1827 case O_LOG: 1828 ipfw_log(chain, f, hlen, args, m, 1829 oif, offset | ip6f_mf, tablearg, ip); 1830 match = 1; 1831 break; 1832 1833 case O_PROB: 1834 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 1835 break; 1836 1837 case O_VERREVPATH: 1838 /* Outgoing packets automatically pass/match */ 1839 match = ((oif != NULL) || 1840 (m->m_pkthdr.rcvif == NULL) || 1841 ( 1842 #ifdef INET6 1843 is_ipv6 ? 1844 verify_path6(&(args->f_id.src_ip6), 1845 m->m_pkthdr.rcvif, args->f_id.fib) : 1846 #endif 1847 verify_path(src_ip, m->m_pkthdr.rcvif, 1848 args->f_id.fib))); 1849 break; 1850 1851 case O_VERSRCREACH: 1852 /* Outgoing packets automatically pass/match */ 1853 match = (hlen > 0 && ((oif != NULL) || 1854 #ifdef INET6 1855 is_ipv6 ? 1856 verify_path6(&(args->f_id.src_ip6), 1857 NULL, args->f_id.fib) : 1858 #endif 1859 verify_path(src_ip, NULL, args->f_id.fib))); 1860 break; 1861 1862 case O_ANTISPOOF: 1863 /* Outgoing packets automatically pass/match */ 1864 if (oif == NULL && hlen > 0 && 1865 ( (is_ipv4 && in_localaddr(src_ip)) 1866 #ifdef INET6 1867 || (is_ipv6 && 1868 in6_localaddr(&(args->f_id.src_ip6))) 1869 #endif 1870 )) 1871 match = 1872 #ifdef INET6 1873 is_ipv6 ? verify_path6( 1874 &(args->f_id.src_ip6), 1875 m->m_pkthdr.rcvif, 1876 args->f_id.fib) : 1877 #endif 1878 verify_path(src_ip, 1879 m->m_pkthdr.rcvif, 1880 args->f_id.fib); 1881 else 1882 match = 1; 1883 break; 1884 1885 case O_IPSEC: 1886 #ifdef IPSEC 1887 match = (m_tag_find(m, 1888 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 1889 #endif 1890 /* otherwise no match */ 1891 break; 1892 1893 #ifdef INET6 1894 case O_IP6_SRC: 1895 match = is_ipv6 && 1896 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 1897 &((ipfw_insn_ip6 *)cmd)->addr6); 1898 break; 1899 1900 case O_IP6_DST: 1901 match = is_ipv6 && 1902 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 1903 &((ipfw_insn_ip6 *)cmd)->addr6); 1904 break; 1905 case O_IP6_SRC_MASK: 1906 case O_IP6_DST_MASK: 1907 if (is_ipv6) { 1908 int i = cmdlen - 1; 1909 struct in6_addr p; 1910 struct in6_addr *d = 1911 &((ipfw_insn_ip6 *)cmd)->addr6; 1912 1913 for (; !match && i > 0; d += 2, 1914 i -= F_INSN_SIZE(struct in6_addr) 1915 * 2) { 1916 p = (cmd->opcode == 1917 O_IP6_SRC_MASK) ? 1918 args->f_id.src_ip6: 1919 args->f_id.dst_ip6; 1920 APPLY_MASK(&p, &d[1]); 1921 match = 1922 IN6_ARE_ADDR_EQUAL(&d[0], 1923 &p); 1924 } 1925 } 1926 break; 1927 1928 case O_FLOW6ID: 1929 match = is_ipv6 && 1930 flow6id_match(args->f_id.flow_id6, 1931 (ipfw_insn_u32 *) cmd); 1932 break; 1933 1934 case O_EXT_HDR: 1935 match = is_ipv6 && 1936 (ext_hd & ((ipfw_insn *) cmd)->arg1); 1937 break; 1938 1939 case O_IP6: 1940 match = is_ipv6; 1941 break; 1942 #endif 1943 1944 case O_IP4: 1945 match = is_ipv4; 1946 break; 1947 1948 case O_TAG: { 1949 struct m_tag *mtag; 1950 uint32_t tag = TARG(cmd->arg1, tag); 1951 1952 /* Packet is already tagged with this tag? */ 1953 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 1954 1955 /* We have `untag' action when F_NOT flag is 1956 * present. And we must remove this mtag from 1957 * mbuf and reset `match' to zero (`match' will 1958 * be inversed later). 1959 * Otherwise we should allocate new mtag and 1960 * push it into mbuf. 1961 */ 1962 if (cmd->len & F_NOT) { /* `untag' action */ 1963 if (mtag != NULL) 1964 m_tag_delete(m, mtag); 1965 match = 0; 1966 } else { 1967 if (mtag == NULL) { 1968 mtag = m_tag_alloc( MTAG_IPFW, 1969 tag, 0, M_NOWAIT); 1970 if (mtag != NULL) 1971 m_tag_prepend(m, mtag); 1972 } 1973 match = 1; 1974 } 1975 break; 1976 } 1977 1978 case O_FIB: /* try match the specified fib */ 1979 if (args->f_id.fib == cmd->arg1) 1980 match = 1; 1981 break; 1982 1983 case O_SOCKARG: { 1984 #ifndef USERSPACE /* not supported in userspace */ 1985 struct inpcb *inp = args->inp; 1986 struct inpcbinfo *pi; 1987 1988 if (is_ipv6) /* XXX can we remove this ? */ 1989 break; 1990 1991 if (proto == IPPROTO_TCP) 1992 pi = &V_tcbinfo; 1993 else if (proto == IPPROTO_UDP) 1994 pi = &V_udbinfo; 1995 else 1996 break; 1997 1998 /* 1999 * XXXRW: so_user_cookie should almost 2000 * certainly be inp_user_cookie? 2001 */ 2002 2003 /* For incoming packet, lookup up the 2004 inpcb using the src/dest ip/port tuple */ 2005 if (inp == NULL) { 2006 inp = in_pcblookup(pi, 2007 src_ip, htons(src_port), 2008 dst_ip, htons(dst_port), 2009 INPLOOKUP_RLOCKPCB, NULL); 2010 if (inp != NULL) { 2011 tablearg = 2012 inp->inp_socket->so_user_cookie; 2013 if (tablearg) 2014 match = 1; 2015 INP_RUNLOCK(inp); 2016 } 2017 } else { 2018 if (inp->inp_socket) { 2019 tablearg = 2020 inp->inp_socket->so_user_cookie; 2021 if (tablearg) 2022 match = 1; 2023 } 2024 } 2025 #endif /* !USERSPACE */ 2026 break; 2027 } 2028 2029 case O_TAGGED: { 2030 struct m_tag *mtag; 2031 uint32_t tag = TARG(cmd->arg1, tag); 2032 2033 if (cmdlen == 1) { 2034 match = m_tag_locate(m, MTAG_IPFW, 2035 tag, NULL) != NULL; 2036 break; 2037 } 2038 2039 /* we have ranges */ 2040 for (mtag = m_tag_first(m); 2041 mtag != NULL && !match; 2042 mtag = m_tag_next(m, mtag)) { 2043 uint16_t *p; 2044 int i; 2045 2046 if (mtag->m_tag_cookie != MTAG_IPFW) 2047 continue; 2048 2049 p = ((ipfw_insn_u16 *)cmd)->ports; 2050 i = cmdlen - 1; 2051 for(; !match && i > 0; i--, p += 2) 2052 match = 2053 mtag->m_tag_id >= p[0] && 2054 mtag->m_tag_id <= p[1]; 2055 } 2056 break; 2057 } 2058 2059 /* 2060 * The second set of opcodes represents 'actions', 2061 * i.e. the terminal part of a rule once the packet 2062 * matches all previous patterns. 2063 * Typically there is only one action for each rule, 2064 * and the opcode is stored at the end of the rule 2065 * (but there are exceptions -- see below). 2066 * 2067 * In general, here we set retval and terminate the 2068 * outer loop (would be a 'break 3' in some language, 2069 * but we need to set l=0, done=1) 2070 * 2071 * Exceptions: 2072 * O_COUNT and O_SKIPTO actions: 2073 * instead of terminating, we jump to the next rule 2074 * (setting l=0), or to the SKIPTO target (setting 2075 * f/f_len, cmd and l as needed), respectively. 2076 * 2077 * O_TAG, O_LOG and O_ALTQ action parameters: 2078 * perform some action and set match = 1; 2079 * 2080 * O_LIMIT and O_KEEP_STATE: these opcodes are 2081 * not real 'actions', and are stored right 2082 * before the 'action' part of the rule. 2083 * These opcodes try to install an entry in the 2084 * state tables; if successful, we continue with 2085 * the next opcode (match=1; break;), otherwise 2086 * the packet must be dropped (set retval, 2087 * break loops with l=0, done=1) 2088 * 2089 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2090 * cause a lookup of the state table, and a jump 2091 * to the 'action' part of the parent rule 2092 * if an entry is found, or 2093 * (CHECK_STATE only) a jump to the next rule if 2094 * the entry is not found. 2095 * The result of the lookup is cached so that 2096 * further instances of these opcodes become NOPs. 2097 * The jump to the next rule is done by setting 2098 * l=0, cmdlen=0. 2099 */ 2100 case O_LIMIT: 2101 case O_KEEP_STATE: 2102 if (ipfw_install_state(chain, f, 2103 (ipfw_insn_limit *)cmd, args, tablearg)) { 2104 /* error or limit violation */ 2105 retval = IP_FW_DENY; 2106 l = 0; /* exit inner loop */ 2107 done = 1; /* exit outer loop */ 2108 } 2109 match = 1; 2110 break; 2111 2112 case O_PROBE_STATE: 2113 case O_CHECK_STATE: 2114 /* 2115 * dynamic rules are checked at the first 2116 * keep-state or check-state occurrence, 2117 * with the result being stored in dyn_dir 2118 * and dyn_name. 2119 * The compiler introduces a PROBE_STATE 2120 * instruction for us when we have a 2121 * KEEP_STATE (because PROBE_STATE needs 2122 * to be run first). 2123 * 2124 * (dyn_dir == MATCH_UNKNOWN) means this is 2125 * first lookup for such f_id. Do lookup. 2126 * 2127 * (dyn_dir != MATCH_UNKNOWN && 2128 * dyn_name != 0 && dyn_name != cmd->arg1) 2129 * means previous lookup didn't find dynamic 2130 * rule for specific state name and current 2131 * lookup will search rule with another state 2132 * name. Redo lookup. 2133 * 2134 * (dyn_dir != MATCH_UNKNOWN && dyn_name == 0) 2135 * means previous lookup was for `any' name 2136 * and it didn't find rule. No need to do 2137 * lookup again. 2138 */ 2139 if ((dyn_dir == MATCH_UNKNOWN || 2140 (dyn_name != 0 && 2141 dyn_name != cmd->arg1)) && 2142 (q = ipfw_lookup_dyn_rule(&args->f_id, 2143 &dyn_dir, proto == IPPROTO_TCP ? 2144 TCP(ulp): NULL, 2145 (dyn_name = cmd->arg1))) != NULL) { 2146 /* 2147 * Found dynamic entry, update stats 2148 * and jump to the 'action' part of 2149 * the parent rule by setting 2150 * f, cmd, l and clearing cmdlen. 2151 */ 2152 IPFW_INC_DYN_COUNTER(q, pktlen); 2153 /* XXX we would like to have f_pos 2154 * readily accessible in the dynamic 2155 * rule, instead of having to 2156 * lookup q->rule. 2157 */ 2158 f = q->rule; 2159 f_pos = ipfw_find_rule(chain, 2160 f->rulenum, f->id); 2161 cmd = ACTION_PTR(f); 2162 l = f->cmd_len - f->act_ofs; 2163 ipfw_dyn_unlock(q); 2164 cmdlen = 0; 2165 match = 1; 2166 break; 2167 } 2168 /* 2169 * Dynamic entry not found. If CHECK_STATE, 2170 * skip to next rule, if PROBE_STATE just 2171 * ignore and continue with next opcode. 2172 */ 2173 if (cmd->opcode == O_CHECK_STATE) 2174 l = 0; /* exit inner loop */ 2175 match = 1; 2176 break; 2177 2178 case O_ACCEPT: 2179 retval = 0; /* accept */ 2180 l = 0; /* exit inner loop */ 2181 done = 1; /* exit outer loop */ 2182 break; 2183 2184 case O_PIPE: 2185 case O_QUEUE: 2186 set_match(args, f_pos, chain); 2187 args->rule.info = TARG(cmd->arg1, pipe); 2188 if (cmd->opcode == O_PIPE) 2189 args->rule.info |= IPFW_IS_PIPE; 2190 if (V_fw_one_pass) 2191 args->rule.info |= IPFW_ONEPASS; 2192 retval = IP_FW_DUMMYNET; 2193 l = 0; /* exit inner loop */ 2194 done = 1; /* exit outer loop */ 2195 break; 2196 2197 case O_DIVERT: 2198 case O_TEE: 2199 if (args->eh) /* not on layer 2 */ 2200 break; 2201 /* otherwise this is terminal */ 2202 l = 0; /* exit inner loop */ 2203 done = 1; /* exit outer loop */ 2204 retval = (cmd->opcode == O_DIVERT) ? 2205 IP_FW_DIVERT : IP_FW_TEE; 2206 set_match(args, f_pos, chain); 2207 args->rule.info = TARG(cmd->arg1, divert); 2208 break; 2209 2210 case O_COUNT: 2211 IPFW_INC_RULE_COUNTER(f, pktlen); 2212 l = 0; /* exit inner loop */ 2213 break; 2214 2215 case O_SKIPTO: 2216 IPFW_INC_RULE_COUNTER(f, pktlen); 2217 f_pos = JUMP(chain, f, cmd->arg1, tablearg, 0); 2218 /* 2219 * Skip disabled rules, and re-enter 2220 * the inner loop with the correct 2221 * f_pos, f, l and cmd. 2222 * Also clear cmdlen and skip_or 2223 */ 2224 for (; f_pos < chain->n_rules - 1 && 2225 (V_set_disable & 2226 (1 << chain->map[f_pos]->set)); 2227 f_pos++) 2228 ; 2229 /* Re-enter the inner loop at the skipto rule. */ 2230 f = chain->map[f_pos]; 2231 l = f->cmd_len; 2232 cmd = f->cmd; 2233 match = 1; 2234 cmdlen = 0; 2235 skip_or = 0; 2236 continue; 2237 break; /* not reached */ 2238 2239 case O_CALLRETURN: { 2240 /* 2241 * Implementation of `subroutine' call/return, 2242 * in the stack carried in an mbuf tag. This 2243 * is different from `skipto' in that any call 2244 * address is possible (`skipto' must prevent 2245 * backward jumps to avoid endless loops). 2246 * We have `return' action when F_NOT flag is 2247 * present. The `m_tag_id' field is used as 2248 * stack pointer. 2249 */ 2250 struct m_tag *mtag; 2251 uint16_t jmpto, *stack; 2252 2253 #define IS_CALL ((cmd->len & F_NOT) == 0) 2254 #define IS_RETURN ((cmd->len & F_NOT) != 0) 2255 /* 2256 * Hand-rolled version of m_tag_locate() with 2257 * wildcard `type'. 2258 * If not already tagged, allocate new tag. 2259 */ 2260 mtag = m_tag_first(m); 2261 while (mtag != NULL) { 2262 if (mtag->m_tag_cookie == 2263 MTAG_IPFW_CALL) 2264 break; 2265 mtag = m_tag_next(m, mtag); 2266 } 2267 if (mtag == NULL && IS_CALL) { 2268 mtag = m_tag_alloc(MTAG_IPFW_CALL, 0, 2269 IPFW_CALLSTACK_SIZE * 2270 sizeof(uint16_t), M_NOWAIT); 2271 if (mtag != NULL) 2272 m_tag_prepend(m, mtag); 2273 } 2274 2275 /* 2276 * On error both `call' and `return' just 2277 * continue with next rule. 2278 */ 2279 if (IS_RETURN && (mtag == NULL || 2280 mtag->m_tag_id == 0)) { 2281 l = 0; /* exit inner loop */ 2282 break; 2283 } 2284 if (IS_CALL && (mtag == NULL || 2285 mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) { 2286 printf("ipfw: call stack error, " 2287 "go to next rule\n"); 2288 l = 0; /* exit inner loop */ 2289 break; 2290 } 2291 2292 IPFW_INC_RULE_COUNTER(f, pktlen); 2293 stack = (uint16_t *)(mtag + 1); 2294 2295 /* 2296 * The `call' action may use cached f_pos 2297 * (in f->next_rule), whose version is written 2298 * in f->next_rule. 2299 * The `return' action, however, doesn't have 2300 * fixed jump address in cmd->arg1 and can't use 2301 * cache. 2302 */ 2303 if (IS_CALL) { 2304 stack[mtag->m_tag_id] = f->rulenum; 2305 mtag->m_tag_id++; 2306 f_pos = JUMP(chain, f, cmd->arg1, 2307 tablearg, 1); 2308 } else { /* `return' action */ 2309 mtag->m_tag_id--; 2310 jmpto = stack[mtag->m_tag_id] + 1; 2311 f_pos = ipfw_find_rule(chain, jmpto, 0); 2312 } 2313 2314 /* 2315 * Skip disabled rules, and re-enter 2316 * the inner loop with the correct 2317 * f_pos, f, l and cmd. 2318 * Also clear cmdlen and skip_or 2319 */ 2320 for (; f_pos < chain->n_rules - 1 && 2321 (V_set_disable & 2322 (1 << chain->map[f_pos]->set)); f_pos++) 2323 ; 2324 /* Re-enter the inner loop at the dest rule. */ 2325 f = chain->map[f_pos]; 2326 l = f->cmd_len; 2327 cmd = f->cmd; 2328 cmdlen = 0; 2329 skip_or = 0; 2330 continue; 2331 break; /* NOTREACHED */ 2332 } 2333 #undef IS_CALL 2334 #undef IS_RETURN 2335 2336 case O_REJECT: 2337 /* 2338 * Drop the packet and send a reject notice 2339 * if the packet is not ICMP (or is an ICMP 2340 * query), and it is not multicast/broadcast. 2341 */ 2342 if (hlen > 0 && is_ipv4 && offset == 0 && 2343 (proto != IPPROTO_ICMP || 2344 is_icmp_query(ICMP(ulp))) && 2345 !(m->m_flags & (M_BCAST|M_MCAST)) && 2346 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 2347 send_reject(args, cmd->arg1, iplen, ip); 2348 m = args->m; 2349 } 2350 /* FALLTHROUGH */ 2351 #ifdef INET6 2352 case O_UNREACH6: 2353 if (hlen > 0 && is_ipv6 && 2354 ((offset & IP6F_OFF_MASK) == 0) && 2355 (proto != IPPROTO_ICMPV6 || 2356 (is_icmp6_query(icmp6_type) == 1)) && 2357 !(m->m_flags & (M_BCAST|M_MCAST)) && 2358 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 2359 send_reject6( 2360 args, cmd->arg1, hlen, 2361 (struct ip6_hdr *)ip); 2362 m = args->m; 2363 } 2364 /* FALLTHROUGH */ 2365 #endif 2366 case O_DENY: 2367 retval = IP_FW_DENY; 2368 l = 0; /* exit inner loop */ 2369 done = 1; /* exit outer loop */ 2370 break; 2371 2372 case O_FORWARD_IP: 2373 if (args->eh) /* not valid on layer2 pkts */ 2374 break; 2375 if (q == NULL || q->rule != f || 2376 dyn_dir == MATCH_FORWARD) { 2377 struct sockaddr_in *sa; 2378 2379 sa = &(((ipfw_insn_sa *)cmd)->sa); 2380 if (sa->sin_addr.s_addr == INADDR_ANY) { 2381 #ifdef INET6 2382 /* 2383 * We use O_FORWARD_IP opcode for 2384 * fwd rule with tablearg, but tables 2385 * now support IPv6 addresses. And 2386 * when we are inspecting IPv6 packet, 2387 * we can use nh6 field from 2388 * table_value as next_hop6 address. 2389 */ 2390 if (is_ipv6) { 2391 struct sockaddr_in6 *sa6; 2392 2393 sa6 = args->next_hop6 = 2394 &args->hopstore6; 2395 sa6->sin6_family = AF_INET6; 2396 sa6->sin6_len = sizeof(*sa6); 2397 sa6->sin6_addr = TARG_VAL( 2398 chain, tablearg, nh6); 2399 /* 2400 * Set sin6_scope_id only for 2401 * link-local unicast addresses. 2402 */ 2403 if (IN6_IS_ADDR_LINKLOCAL( 2404 &sa6->sin6_addr)) 2405 sa6->sin6_scope_id = 2406 TARG_VAL(chain, 2407 tablearg, 2408 zoneid); 2409 } else 2410 #endif 2411 { 2412 sa = args->next_hop = 2413 &args->hopstore; 2414 sa->sin_family = AF_INET; 2415 sa->sin_len = sizeof(*sa); 2416 sa->sin_addr.s_addr = htonl( 2417 TARG_VAL(chain, tablearg, 2418 nh4)); 2419 } 2420 } else { 2421 args->next_hop = sa; 2422 } 2423 } 2424 retval = IP_FW_PASS; 2425 l = 0; /* exit inner loop */ 2426 done = 1; /* exit outer loop */ 2427 break; 2428 2429 #ifdef INET6 2430 case O_FORWARD_IP6: 2431 if (args->eh) /* not valid on layer2 pkts */ 2432 break; 2433 if (q == NULL || q->rule != f || 2434 dyn_dir == MATCH_FORWARD) { 2435 struct sockaddr_in6 *sin6; 2436 2437 sin6 = &(((ipfw_insn_sa6 *)cmd)->sa); 2438 args->next_hop6 = sin6; 2439 } 2440 retval = IP_FW_PASS; 2441 l = 0; /* exit inner loop */ 2442 done = 1; /* exit outer loop */ 2443 break; 2444 #endif 2445 2446 case O_NETGRAPH: 2447 case O_NGTEE: 2448 set_match(args, f_pos, chain); 2449 args->rule.info = TARG(cmd->arg1, netgraph); 2450 if (V_fw_one_pass) 2451 args->rule.info |= IPFW_ONEPASS; 2452 retval = (cmd->opcode == O_NETGRAPH) ? 2453 IP_FW_NETGRAPH : IP_FW_NGTEE; 2454 l = 0; /* exit inner loop */ 2455 done = 1; /* exit outer loop */ 2456 break; 2457 2458 case O_SETFIB: { 2459 uint32_t fib; 2460 2461 IPFW_INC_RULE_COUNTER(f, pktlen); 2462 fib = TARG(cmd->arg1, fib) & 0x7FFF; 2463 if (fib >= rt_numfibs) 2464 fib = 0; 2465 M_SETFIB(m, fib); 2466 args->f_id.fib = fib; 2467 l = 0; /* exit inner loop */ 2468 break; 2469 } 2470 2471 case O_SETDSCP: { 2472 uint16_t code; 2473 2474 code = TARG(cmd->arg1, dscp) & 0x3F; 2475 l = 0; /* exit inner loop */ 2476 if (is_ipv4) { 2477 uint16_t old; 2478 2479 old = *(uint16_t *)ip; 2480 ip->ip_tos = (code << 2) | 2481 (ip->ip_tos & 0x03); 2482 ip->ip_sum = cksum_adjust(ip->ip_sum, 2483 old, *(uint16_t *)ip); 2484 } else if (is_ipv6) { 2485 uint8_t *v; 2486 2487 v = &((struct ip6_hdr *)ip)->ip6_vfc; 2488 *v = (*v & 0xF0) | (code >> 2); 2489 v++; 2490 *v = (*v & 0x3F) | ((code & 0x03) << 6); 2491 } else 2492 break; 2493 2494 IPFW_INC_RULE_COUNTER(f, pktlen); 2495 break; 2496 } 2497 2498 case O_NAT: 2499 l = 0; /* exit inner loop */ 2500 done = 1; /* exit outer loop */ 2501 if (!IPFW_NAT_LOADED) { 2502 retval = IP_FW_DENY; 2503 break; 2504 } 2505 2506 struct cfg_nat *t; 2507 int nat_id; 2508 2509 set_match(args, f_pos, chain); 2510 /* Check if this is 'global' nat rule */ 2511 if (cmd->arg1 == IP_FW_NAT44_GLOBAL) { 2512 retval = ipfw_nat_ptr(args, NULL, m); 2513 break; 2514 } 2515 t = ((ipfw_insn_nat *)cmd)->nat; 2516 if (t == NULL) { 2517 nat_id = TARG(cmd->arg1, nat); 2518 t = (*lookup_nat_ptr)(&chain->nat, nat_id); 2519 2520 if (t == NULL) { 2521 retval = IP_FW_DENY; 2522 break; 2523 } 2524 if (cmd->arg1 != IP_FW_TARG) 2525 ((ipfw_insn_nat *)cmd)->nat = t; 2526 } 2527 retval = ipfw_nat_ptr(args, t, m); 2528 break; 2529 2530 case O_REASS: { 2531 int ip_off; 2532 2533 IPFW_INC_RULE_COUNTER(f, pktlen); 2534 l = 0; /* in any case exit inner loop */ 2535 ip_off = ntohs(ip->ip_off); 2536 2537 /* if not fragmented, go to next rule */ 2538 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0) 2539 break; 2540 2541 args->m = m = ip_reass(m); 2542 2543 /* 2544 * do IP header checksum fixup. 2545 */ 2546 if (m == NULL) { /* fragment got swallowed */ 2547 retval = IP_FW_DENY; 2548 } else { /* good, packet complete */ 2549 int hlen; 2550 2551 ip = mtod(m, struct ip *); 2552 hlen = ip->ip_hl << 2; 2553 ip->ip_sum = 0; 2554 if (hlen == sizeof(struct ip)) 2555 ip->ip_sum = in_cksum_hdr(ip); 2556 else 2557 ip->ip_sum = in_cksum(m, hlen); 2558 retval = IP_FW_REASS; 2559 set_match(args, f_pos, chain); 2560 } 2561 done = 1; /* exit outer loop */ 2562 break; 2563 } 2564 case O_EXTERNAL_ACTION: 2565 l = 0; /* in any case exit inner loop */ 2566 retval = ipfw_run_eaction(chain, args, 2567 cmd, &done); 2568 break; 2569 2570 default: 2571 panic("-- unknown opcode %d\n", cmd->opcode); 2572 } /* end of switch() on opcodes */ 2573 /* 2574 * if we get here with l=0, then match is irrelevant. 2575 */ 2576 2577 if (cmd->len & F_NOT) 2578 match = !match; 2579 2580 if (match) { 2581 if (cmd->len & F_OR) 2582 skip_or = 1; 2583 } else { 2584 if (!(cmd->len & F_OR)) /* not an OR block, */ 2585 break; /* try next rule */ 2586 } 2587 2588 } /* end of inner loop, scan opcodes */ 2589 #undef PULLUP_LEN 2590 2591 if (done) 2592 break; 2593 2594 /* next_rule:; */ /* try next rule */ 2595 2596 } /* end of outer for, scan rules */ 2597 2598 if (done) { 2599 struct ip_fw *rule = chain->map[f_pos]; 2600 /* Update statistics */ 2601 IPFW_INC_RULE_COUNTER(rule, pktlen); 2602 } else { 2603 retval = IP_FW_DENY; 2604 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 2605 } 2606 IPFW_PF_RUNLOCK(chain); 2607 #ifdef __FreeBSD__ 2608 if (ucred_cache != NULL) 2609 crfree(ucred_cache); 2610 #endif 2611 return (retval); 2612 2613 pullup_failed: 2614 if (V_fw_verbose) 2615 printf("ipfw: pullup failed\n"); 2616 return (IP_FW_DENY); 2617 } 2618 2619 /* 2620 * Set maximum number of tables that can be used in given VNET ipfw instance. 2621 */ 2622 #ifdef SYSCTL_NODE 2623 static int 2624 sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS) 2625 { 2626 int error; 2627 unsigned int ntables; 2628 2629 ntables = V_fw_tables_max; 2630 2631 error = sysctl_handle_int(oidp, &ntables, 0, req); 2632 /* Read operation or some error */ 2633 if ((error != 0) || (req->newptr == NULL)) 2634 return (error); 2635 2636 return (ipfw_resize_tables(&V_layer3_chain, ntables)); 2637 } 2638 2639 /* 2640 * Switches table namespace between global and per-set. 2641 */ 2642 static int 2643 sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS) 2644 { 2645 int error; 2646 unsigned int sets; 2647 2648 sets = V_fw_tables_sets; 2649 2650 error = sysctl_handle_int(oidp, &sets, 0, req); 2651 /* Read operation or some error */ 2652 if ((error != 0) || (req->newptr == NULL)) 2653 return (error); 2654 2655 return (ipfw_switch_tables_namespace(&V_layer3_chain, sets)); 2656 } 2657 #endif 2658 2659 /* 2660 * Module and VNET glue 2661 */ 2662 2663 /* 2664 * Stuff that must be initialised only on boot or module load 2665 */ 2666 static int 2667 ipfw_init(void) 2668 { 2669 int error = 0; 2670 2671 /* 2672 * Only print out this stuff the first time around, 2673 * when called from the sysinit code. 2674 */ 2675 printf("ipfw2 " 2676 #ifdef INET6 2677 "(+ipv6) " 2678 #endif 2679 "initialized, divert %s, nat %s, " 2680 "default to %s, logging ", 2681 #ifdef IPDIVERT 2682 "enabled", 2683 #else 2684 "loadable", 2685 #endif 2686 #ifdef IPFIREWALL_NAT 2687 "enabled", 2688 #else 2689 "loadable", 2690 #endif 2691 default_to_accept ? "accept" : "deny"); 2692 2693 /* 2694 * Note: V_xxx variables can be accessed here but the vnet specific 2695 * initializer may not have been called yet for the VIMAGE case. 2696 * Tuneables will have been processed. We will print out values for 2697 * the default vnet. 2698 * XXX This should all be rationalized AFTER 8.0 2699 */ 2700 if (V_fw_verbose == 0) 2701 printf("disabled\n"); 2702 else if (V_verbose_limit == 0) 2703 printf("unlimited\n"); 2704 else 2705 printf("limited to %d packets/entry by default\n", 2706 V_verbose_limit); 2707 2708 /* Check user-supplied table count for validness */ 2709 if (default_fw_tables > IPFW_TABLES_MAX) 2710 default_fw_tables = IPFW_TABLES_MAX; 2711 2712 ipfw_init_sopt_handler(); 2713 ipfw_init_obj_rewriter(); 2714 ipfw_iface_init(); 2715 return (error); 2716 } 2717 2718 /* 2719 * Called for the removal of the last instance only on module unload. 2720 */ 2721 static void 2722 ipfw_destroy(void) 2723 { 2724 2725 ipfw_iface_destroy(); 2726 ipfw_destroy_sopt_handler(); 2727 ipfw_destroy_obj_rewriter(); 2728 printf("IP firewall unloaded\n"); 2729 } 2730 2731 /* 2732 * Stuff that must be initialized for every instance 2733 * (including the first of course). 2734 */ 2735 static int 2736 vnet_ipfw_init(const void *unused) 2737 { 2738 int error, first; 2739 struct ip_fw *rule = NULL; 2740 struct ip_fw_chain *chain; 2741 2742 chain = &V_layer3_chain; 2743 2744 first = IS_DEFAULT_VNET(curvnet) ? 1 : 0; 2745 2746 /* First set up some values that are compile time options */ 2747 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 2748 V_fw_deny_unknown_exthdrs = 1; 2749 #ifdef IPFIREWALL_VERBOSE 2750 V_fw_verbose = 1; 2751 #endif 2752 #ifdef IPFIREWALL_VERBOSE_LIMIT 2753 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 2754 #endif 2755 #ifdef IPFIREWALL_NAT 2756 LIST_INIT(&chain->nat); 2757 #endif 2758 2759 /* Init shared services hash table */ 2760 ipfw_init_srv(chain); 2761 2762 ipfw_init_counters(); 2763 /* insert the default rule and create the initial map */ 2764 chain->n_rules = 1; 2765 chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_WAITOK | M_ZERO); 2766 rule = ipfw_alloc_rule(chain, sizeof(struct ip_fw)); 2767 2768 /* Set initial number of tables */ 2769 V_fw_tables_max = default_fw_tables; 2770 error = ipfw_init_tables(chain, first); 2771 if (error) { 2772 printf("ipfw2: setting up tables failed\n"); 2773 free(chain->map, M_IPFW); 2774 free(rule, M_IPFW); 2775 return (ENOSPC); 2776 } 2777 2778 /* fill and insert the default rule */ 2779 rule->act_ofs = 0; 2780 rule->rulenum = IPFW_DEFAULT_RULE; 2781 rule->cmd_len = 1; 2782 rule->set = RESVD_SET; 2783 rule->cmd[0].len = 1; 2784 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY; 2785 chain->default_rule = chain->map[0] = rule; 2786 chain->id = rule->id = 1; 2787 /* Pre-calculate rules length for legacy dump format */ 2788 chain->static_len = sizeof(struct ip_fw_rule0); 2789 2790 IPFW_LOCK_INIT(chain); 2791 ipfw_dyn_init(chain); 2792 ipfw_eaction_init(chain, first); 2793 #ifdef LINEAR_SKIPTO 2794 ipfw_init_skipto_cache(chain); 2795 #endif 2796 ipfw_bpf_init(first); 2797 2798 /* First set up some values that are compile time options */ 2799 V_ipfw_vnet_ready = 1; /* Open for business */ 2800 2801 /* 2802 * Hook the sockopt handler and pfil hooks for ipv4 and ipv6. 2803 * Even if the latter two fail we still keep the module alive 2804 * because the sockopt and layer2 paths are still useful. 2805 * ipfw[6]_hook return 0 on success, ENOENT on failure, 2806 * so we can ignore the exact return value and just set a flag. 2807 * 2808 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so 2809 * changes in the underlying (per-vnet) variables trigger 2810 * immediate hook()/unhook() calls. 2811 * In layer2 we have the same behaviour, except that V_ether_ipfw 2812 * is checked on each packet because there are no pfil hooks. 2813 */ 2814 V_ip_fw_ctl_ptr = ipfw_ctl3; 2815 error = ipfw_attach_hooks(1); 2816 return (error); 2817 } 2818 2819 /* 2820 * Called for the removal of each instance. 2821 */ 2822 static int 2823 vnet_ipfw_uninit(const void *unused) 2824 { 2825 struct ip_fw *reap; 2826 struct ip_fw_chain *chain = &V_layer3_chain; 2827 int i, last; 2828 2829 V_ipfw_vnet_ready = 0; /* tell new callers to go away */ 2830 /* 2831 * disconnect from ipv4, ipv6, layer2 and sockopt. 2832 * Then grab, release and grab again the WLOCK so we make 2833 * sure the update is propagated and nobody will be in. 2834 */ 2835 (void)ipfw_attach_hooks(0 /* detach */); 2836 V_ip_fw_ctl_ptr = NULL; 2837 2838 last = IS_DEFAULT_VNET(curvnet) ? 1 : 0; 2839 2840 IPFW_UH_WLOCK(chain); 2841 IPFW_UH_WUNLOCK(chain); 2842 2843 ipfw_dyn_uninit(0); /* run the callout_drain */ 2844 2845 IPFW_UH_WLOCK(chain); 2846 2847 reap = NULL; 2848 IPFW_WLOCK(chain); 2849 for (i = 0; i < chain->n_rules; i++) 2850 ipfw_reap_add(chain, &reap, chain->map[i]); 2851 free(chain->map, M_IPFW); 2852 #ifdef LINEAR_SKIPTO 2853 ipfw_destroy_skipto_cache(chain); 2854 #endif 2855 IPFW_WUNLOCK(chain); 2856 IPFW_UH_WUNLOCK(chain); 2857 ipfw_destroy_tables(chain, last); 2858 ipfw_eaction_uninit(chain, last); 2859 if (reap != NULL) 2860 ipfw_reap_rules(reap); 2861 vnet_ipfw_iface_destroy(chain); 2862 ipfw_destroy_srv(chain); 2863 IPFW_LOCK_DESTROY(chain); 2864 ipfw_dyn_uninit(1); /* free the remaining parts */ 2865 ipfw_destroy_counters(); 2866 ipfw_bpf_uninit(last); 2867 return (0); 2868 } 2869 2870 /* 2871 * Module event handler. 2872 * In general we have the choice of handling most of these events by the 2873 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to 2874 * use the SYSINIT handlers as they are more capable of expressing the 2875 * flow of control during module and vnet operations, so this is just 2876 * a skeleton. Note there is no SYSINIT equivalent of the module 2877 * SHUTDOWN handler, but we don't have anything to do in that case anyhow. 2878 */ 2879 static int 2880 ipfw_modevent(module_t mod, int type, void *unused) 2881 { 2882 int err = 0; 2883 2884 switch (type) { 2885 case MOD_LOAD: 2886 /* Called once at module load or 2887 * system boot if compiled in. */ 2888 break; 2889 case MOD_QUIESCE: 2890 /* Called before unload. May veto unloading. */ 2891 break; 2892 case MOD_UNLOAD: 2893 /* Called during unload. */ 2894 break; 2895 case MOD_SHUTDOWN: 2896 /* Called during system shutdown. */ 2897 break; 2898 default: 2899 err = EOPNOTSUPP; 2900 break; 2901 } 2902 return err; 2903 } 2904 2905 static moduledata_t ipfwmod = { 2906 "ipfw", 2907 ipfw_modevent, 2908 0 2909 }; 2910 2911 /* Define startup order. */ 2912 #define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_FIREWALL 2913 #define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */ 2914 #define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */ 2915 #define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */ 2916 2917 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER); 2918 FEATURE(ipfw_ctl3, "ipfw new sockopt calls"); 2919 MODULE_VERSION(ipfw, 3); 2920 /* should declare some dependencies here */ 2921 2922 /* 2923 * Starting up. Done in order after ipfwmod() has been called. 2924 * VNET_SYSINIT is also called for each existing vnet and each new vnet. 2925 */ 2926 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 2927 ipfw_init, NULL); 2928 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 2929 vnet_ipfw_init, NULL); 2930 2931 /* 2932 * Closing up shop. These are done in REVERSE ORDER, but still 2933 * after ipfwmod() has been called. Not called on reboot. 2934 * VNET_SYSUNINIT is also called for each exiting vnet as it exits. 2935 * or when the module is unloaded. 2936 */ 2937 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 2938 ipfw_destroy, NULL); 2939 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 2940 vnet_ipfw_uninit, NULL); 2941 /* end of file */ 2942