ip_fw2.c revision 161767
1/*- 2 * Copyright (c) 2002 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 * $FreeBSD: head/sys/netinet/ip_fw2.c 161767 2006-08-31 16:56:45Z jhay $ 26 */ 27 28#define DEB(x) 29#define DDB(x) x 30 31/* 32 * Implement IP packet firewall (new version) 33 */ 34 35#if !defined(KLD_MODULE) 36#include "opt_ipfw.h" 37#include "opt_ipdn.h" 38#include "opt_inet.h" 39#ifndef INET 40#error IPFIREWALL requires INET. 41#endif /* INET */ 42#endif 43#include "opt_inet6.h" 44#include "opt_ipsec.h" 45 46#include <sys/param.h> 47#include <sys/systm.h> 48#include <sys/condvar.h> 49#include <sys/malloc.h> 50#include <sys/mbuf.h> 51#include <sys/kernel.h> 52#include <sys/lock.h> 53#include <sys/jail.h> 54#include <sys/module.h> 55#include <sys/proc.h> 56#include <sys/rwlock.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/if.h> 63#include <net/radix.h> 64#include <net/route.h> 65#include <netinet/in.h> 66#include <netinet/in_systm.h> 67#include <netinet/in_var.h> 68#include <netinet/in_pcb.h> 69#include <netinet/ip.h> 70#include <netinet/ip_var.h> 71#include <netinet/ip_icmp.h> 72#include <netinet/ip_fw.h> 73#include <netinet/ip_divert.h> 74#include <netinet/ip_dummynet.h> 75#include <netinet/pim.h> 76#include <netinet/tcp.h> 77#include <netinet/tcp_timer.h> 78#include <netinet/tcp_var.h> 79#include <netinet/tcpip.h> 80#include <netinet/udp.h> 81#include <netinet/udp_var.h> 82 83#include <netgraph/ng_ipfw.h> 84 85#include <altq/if_altq.h> 86 87#ifdef IPSEC 88#include <netinet6/ipsec.h> 89#endif 90 91#include <netinet/ip6.h> 92#include <netinet/icmp6.h> 93#ifdef INET6 94#include <netinet6/scope6_var.h> 95#endif 96 97#include <netinet/if_ether.h> /* XXX for ETHERTYPE_IP */ 98 99#include <machine/in_cksum.h> /* XXX for in_cksum */ 100 101/* 102 * set_disable contains one bit per set value (0..31). 103 * If the bit is set, all rules with the corresponding set 104 * are disabled. Set RESVD_SET(31) is reserved for the default rule 105 * and rules that are not deleted by the flush command, 106 * and CANNOT be disabled. 107 * Rules in set RESVD_SET can only be deleted explicitly. 108 */ 109static u_int32_t set_disable; 110 111static int fw_verbose; 112static int verbose_limit; 113 114static struct callout ipfw_timeout; 115static uma_zone_t ipfw_dyn_rule_zone; 116#define IPFW_DEFAULT_RULE 65535 117 118/* 119 * Data structure to cache our ucred related 120 * information. This structure only gets used if 121 * the user specified UID/GID based constraints in 122 * a firewall rule. 123 */ 124struct ip_fw_ugid { 125 gid_t fw_groups[NGROUPS]; 126 int fw_ngroups; 127 uid_t fw_uid; 128 int fw_prid; 129}; 130 131#define IPFW_TABLES_MAX 128 132struct ip_fw_chain { 133 struct ip_fw *rules; /* list of rules */ 134 struct ip_fw *reap; /* list of rules to reap */ 135 struct radix_node_head *tables[IPFW_TABLES_MAX]; 136 struct rwlock rwmtx; 137}; 138#define IPFW_LOCK_INIT(_chain) \ 139 rw_init(&(_chain)->rwmtx, "IPFW static rules") 140#define IPFW_LOCK_DESTROY(_chain) rw_destroy(&(_chain)->rwmtx) 141#define IPFW_WLOCK_ASSERT(_chain) do { \ 142 rw_assert(&(_chain)->rwmtx, RA_WLOCKED); \ 143 NET_ASSERT_GIANT(); \ 144} while (0) 145 146#define IPFW_RLOCK(p) rw_rlock(&(p)->rwmtx) 147#define IPFW_RUNLOCK(p) rw_runlock(&(p)->rwmtx) 148#define IPFW_WLOCK(p) rw_wlock(&(p)->rwmtx) 149#define IPFW_WUNLOCK(p) rw_wunlock(&(p)->rwmtx) 150 151/* 152 * list of rules for layer 3 153 */ 154static struct ip_fw_chain layer3_chain; 155 156MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's"); 157MALLOC_DEFINE(M_IPFW_TBL, "ipfw_tbl", "IpFw tables"); 158 159struct table_entry { 160 struct radix_node rn[2]; 161 struct sockaddr_in addr, mask; 162 u_int32_t value; 163}; 164 165static int fw_debug = 1; 166static int autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 167 168extern int ipfw_chg_hook(SYSCTL_HANDLER_ARGS); 169 170#ifdef SYSCTL_NODE 171SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 172SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, enable, 173 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3, &fw_enable, 0, 174 ipfw_chg_hook, "I", "Enable ipfw"); 175SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, CTLFLAG_RW, 176 &autoinc_step, 0, "Rule number autincrement step"); 177SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 178 CTLFLAG_RW | CTLFLAG_SECURE3, 179 &fw_one_pass, 0, 180 "Only do a single pass through ipfw when using dummynet(4)"); 181SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW, 182 &fw_debug, 0, "Enable printing of debug ip_fw statements"); 183SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, 184 CTLFLAG_RW | CTLFLAG_SECURE3, 185 &fw_verbose, 0, "Log matches to ipfw rules"); 186SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, 187 &verbose_limit, 0, "Set upper limit of matches of ipfw rules logged"); 188 189/* 190 * Description of dynamic rules. 191 * 192 * Dynamic rules are stored in lists accessed through a hash table 193 * (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can 194 * be modified through the sysctl variable dyn_buckets which is 195 * updated when the table becomes empty. 196 * 197 * XXX currently there is only one list, ipfw_dyn. 198 * 199 * When a packet is received, its address fields are first masked 200 * with the mask defined for the rule, then hashed, then matched 201 * against the entries in the corresponding list. 202 * Dynamic rules can be used for different purposes: 203 * + stateful rules; 204 * + enforcing limits on the number of sessions; 205 * + in-kernel NAT (not implemented yet) 206 * 207 * The lifetime of dynamic rules is regulated by dyn_*_lifetime, 208 * measured in seconds and depending on the flags. 209 * 210 * The total number of dynamic rules is stored in dyn_count. 211 * The max number of dynamic rules is dyn_max. When we reach 212 * the maximum number of rules we do not create anymore. This is 213 * done to avoid consuming too much memory, but also too much 214 * time when searching on each packet (ideally, we should try instead 215 * to put a limit on the length of the list on each bucket...). 216 * 217 * Each dynamic rule holds a pointer to the parent ipfw rule so 218 * we know what action to perform. Dynamic rules are removed when 219 * the parent rule is deleted. XXX we should make them survive. 220 * 221 * There are some limitations with dynamic rules -- we do not 222 * obey the 'randomized match', and we do not do multiple 223 * passes through the firewall. XXX check the latter!!! 224 */ 225static ipfw_dyn_rule **ipfw_dyn_v = NULL; 226static u_int32_t dyn_buckets = 256; /* must be power of 2 */ 227static u_int32_t curr_dyn_buckets = 256; /* must be power of 2 */ 228 229static struct mtx ipfw_dyn_mtx; /* mutex guarding dynamic rules */ 230#define IPFW_DYN_LOCK_INIT() \ 231 mtx_init(&ipfw_dyn_mtx, "IPFW dynamic rules", NULL, MTX_DEF) 232#define IPFW_DYN_LOCK_DESTROY() mtx_destroy(&ipfw_dyn_mtx) 233#define IPFW_DYN_LOCK() mtx_lock(&ipfw_dyn_mtx) 234#define IPFW_DYN_UNLOCK() mtx_unlock(&ipfw_dyn_mtx) 235#define IPFW_DYN_LOCK_ASSERT() mtx_assert(&ipfw_dyn_mtx, MA_OWNED) 236 237/* 238 * Timeouts for various events in handing dynamic rules. 239 */ 240static u_int32_t dyn_ack_lifetime = 300; 241static u_int32_t dyn_syn_lifetime = 20; 242static u_int32_t dyn_fin_lifetime = 1; 243static u_int32_t dyn_rst_lifetime = 1; 244static u_int32_t dyn_udp_lifetime = 10; 245static u_int32_t dyn_short_lifetime = 5; 246 247/* 248 * Keepalives are sent if dyn_keepalive is set. They are sent every 249 * dyn_keepalive_period seconds, in the last dyn_keepalive_interval 250 * seconds of lifetime of a rule. 251 * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower 252 * than dyn_keepalive_period. 253 */ 254 255static u_int32_t dyn_keepalive_interval = 20; 256static u_int32_t dyn_keepalive_period = 5; 257static u_int32_t dyn_keepalive = 1; /* do send keepalives */ 258 259static u_int32_t static_count; /* # of static rules */ 260static u_int32_t static_len; /* size in bytes of static rules */ 261static u_int32_t dyn_count; /* # of dynamic rules */ 262static u_int32_t dyn_max = 4096; /* max # of dynamic rules */ 263 264SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLFLAG_RW, 265 &dyn_buckets, 0, "Number of dyn. buckets"); 266SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_RD, 267 &curr_dyn_buckets, 0, "Current Number of dyn. buckets"); 268SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_RD, 269 &dyn_count, 0, "Number of dyn. rules"); 270SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_RW, 271 &dyn_max, 0, "Max number of dyn. rules"); 272SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, CTLFLAG_RD, 273 &static_count, 0, "Number of static rules"); 274SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_RW, 275 &dyn_ack_lifetime, 0, "Lifetime of dyn. rules for acks"); 276SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_RW, 277 &dyn_syn_lifetime, 0, "Lifetime of dyn. rules for syn"); 278SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, CTLFLAG_RW, 279 &dyn_fin_lifetime, 0, "Lifetime of dyn. rules for fin"); 280SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, CTLFLAG_RW, 281 &dyn_rst_lifetime, 0, "Lifetime of dyn. rules for rst"); 282SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime, CTLFLAG_RW, 283 &dyn_udp_lifetime, 0, "Lifetime of dyn. rules for UDP"); 284SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_RW, 285 &dyn_short_lifetime, 0, "Lifetime of dyn. rules for other situations"); 286SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_keepalive, CTLFLAG_RW, 287 &dyn_keepalive, 0, "Enable keepalives for dyn. rules"); 288 289#ifdef INET6 290/* 291 * IPv6 specific variables 292 */ 293SYSCTL_DECL(_net_inet6_ip6); 294 295static struct sysctl_ctx_list ip6_fw_sysctl_ctx; 296static struct sysctl_oid *ip6_fw_sysctl_tree; 297#endif /* INET6 */ 298#endif /* SYSCTL_NODE */ 299 300static int fw_deny_unknown_exthdrs = 1; 301 302 303/* 304 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 305 * Other macros just cast void * into the appropriate type 306 */ 307#define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 308#define TCP(p) ((struct tcphdr *)(p)) 309#define UDP(p) ((struct udphdr *)(p)) 310#define ICMP(p) ((struct icmphdr *)(p)) 311#define ICMP6(p) ((struct icmp6_hdr *)(p)) 312 313static __inline int 314icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 315{ 316 int type = icmp->icmp_type; 317 318 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 319} 320 321#define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 322 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 323 324static int 325is_icmp_query(struct icmphdr *icmp) 326{ 327 int type = icmp->icmp_type; 328 329 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 330} 331#undef TT 332 333/* 334 * The following checks use two arrays of 8 or 16 bits to store the 335 * bits that we want set or clear, respectively. They are in the 336 * low and high half of cmd->arg1 or cmd->d[0]. 337 * 338 * We scan options and store the bits we find set. We succeed if 339 * 340 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 341 * 342 * The code is sometimes optimized not to store additional variables. 343 */ 344 345static int 346flags_match(ipfw_insn *cmd, u_int8_t bits) 347{ 348 u_char want_clear; 349 bits = ~bits; 350 351 if ( ((cmd->arg1 & 0xff) & bits) != 0) 352 return 0; /* some bits we want set were clear */ 353 want_clear = (cmd->arg1 >> 8) & 0xff; 354 if ( (want_clear & bits) != want_clear) 355 return 0; /* some bits we want clear were set */ 356 return 1; 357} 358 359static int 360ipopts_match(struct ip *ip, ipfw_insn *cmd) 361{ 362 int optlen, bits = 0; 363 u_char *cp = (u_char *)(ip + 1); 364 int x = (ip->ip_hl << 2) - sizeof (struct ip); 365 366 for (; x > 0; x -= optlen, cp += optlen) { 367 int opt = cp[IPOPT_OPTVAL]; 368 369 if (opt == IPOPT_EOL) 370 break; 371 if (opt == IPOPT_NOP) 372 optlen = 1; 373 else { 374 optlen = cp[IPOPT_OLEN]; 375 if (optlen <= 0 || optlen > x) 376 return 0; /* invalid or truncated */ 377 } 378 switch (opt) { 379 380 default: 381 break; 382 383 case IPOPT_LSRR: 384 bits |= IP_FW_IPOPT_LSRR; 385 break; 386 387 case IPOPT_SSRR: 388 bits |= IP_FW_IPOPT_SSRR; 389 break; 390 391 case IPOPT_RR: 392 bits |= IP_FW_IPOPT_RR; 393 break; 394 395 case IPOPT_TS: 396 bits |= IP_FW_IPOPT_TS; 397 break; 398 } 399 } 400 return (flags_match(cmd, bits)); 401} 402 403static int 404tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 405{ 406 int optlen, bits = 0; 407 u_char *cp = (u_char *)(tcp + 1); 408 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 409 410 for (; x > 0; x -= optlen, cp += optlen) { 411 int opt = cp[0]; 412 if (opt == TCPOPT_EOL) 413 break; 414 if (opt == TCPOPT_NOP) 415 optlen = 1; 416 else { 417 optlen = cp[1]; 418 if (optlen <= 0) 419 break; 420 } 421 422 switch (opt) { 423 424 default: 425 break; 426 427 case TCPOPT_MAXSEG: 428 bits |= IP_FW_TCPOPT_MSS; 429 break; 430 431 case TCPOPT_WINDOW: 432 bits |= IP_FW_TCPOPT_WINDOW; 433 break; 434 435 case TCPOPT_SACK_PERMITTED: 436 case TCPOPT_SACK: 437 bits |= IP_FW_TCPOPT_SACK; 438 break; 439 440 case TCPOPT_TIMESTAMP: 441 bits |= IP_FW_TCPOPT_TS; 442 break; 443 444 } 445 } 446 return (flags_match(cmd, bits)); 447} 448 449static int 450iface_match(struct ifnet *ifp, ipfw_insn_if *cmd) 451{ 452 if (ifp == NULL) /* no iface with this packet, match fails */ 453 return 0; 454 /* Check by name or by IP address */ 455 if (cmd->name[0] != '\0') { /* match by name */ 456 /* Check name */ 457 if (cmd->p.glob) { 458 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 459 return(1); 460 } else { 461 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 462 return(1); 463 } 464 } else { 465 struct ifaddr *ia; 466 467 /* XXX lock? */ 468 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 469 if (ia->ifa_addr->sa_family != AF_INET) 470 continue; 471 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 472 (ia->ifa_addr))->sin_addr.s_addr) 473 return(1); /* match */ 474 } 475 } 476 return(0); /* no match, fail ... */ 477} 478 479/* 480 * The verify_path function checks if a route to the src exists and 481 * if it is reachable via ifp (when provided). 482 * 483 * The 'verrevpath' option checks that the interface that an IP packet 484 * arrives on is the same interface that traffic destined for the 485 * packet's source address would be routed out of. The 'versrcreach' 486 * option just checks that the source address is reachable via any route 487 * (except default) in the routing table. These two are a measure to block 488 * forged packets. This is also commonly known as "anti-spoofing" or Unicast 489 * Reverse Path Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 490 * is purposely reminiscent of the Cisco IOS command, 491 * 492 * ip verify unicast reverse-path 493 * ip verify unicast source reachable-via any 494 * 495 * which implements the same functionality. But note that syntax is 496 * misleading. The check may be performed on all IP packets whether unicast, 497 * multicast, or broadcast. 498 */ 499static int 500verify_path(struct in_addr src, struct ifnet *ifp) 501{ 502 struct route ro; 503 struct sockaddr_in *dst; 504 505 bzero(&ro, sizeof(ro)); 506 507 dst = (struct sockaddr_in *)&(ro.ro_dst); 508 dst->sin_family = AF_INET; 509 dst->sin_len = sizeof(*dst); 510 dst->sin_addr = src; 511 rtalloc_ign(&ro, RTF_CLONING); 512 513 if (ro.ro_rt == NULL) 514 return 0; 515 516 /* 517 * If ifp is provided, check for equality with rtentry. 518 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 519 * in order to pass packets injected back by if_simloop(): 520 * if useloopback == 1 routing entry (via lo0) for our own address 521 * may exist, so we need to handle routing assymetry. 522 */ 523 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 524 RTFREE(ro.ro_rt); 525 return 0; 526 } 527 528 /* if no ifp provided, check if rtentry is not default route */ 529 if (ifp == NULL && 530 satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) { 531 RTFREE(ro.ro_rt); 532 return 0; 533 } 534 535 /* or if this is a blackhole/reject route */ 536 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 537 RTFREE(ro.ro_rt); 538 return 0; 539 } 540 541 /* found valid route */ 542 RTFREE(ro.ro_rt); 543 return 1; 544} 545 546#ifdef INET6 547/* 548 * ipv6 specific rules here... 549 */ 550static __inline int 551icmp6type_match (int type, ipfw_insn_u32 *cmd) 552{ 553 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 554} 555 556static int 557flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 558{ 559 int i; 560 for (i=0; i <= cmd->o.arg1; ++i ) 561 if (curr_flow == cmd->d[i] ) 562 return 1; 563 return 0; 564} 565 566/* support for IP6_*_ME opcodes */ 567static int 568search_ip6_addr_net (struct in6_addr * ip6_addr) 569{ 570 struct ifnet *mdc; 571 struct ifaddr *mdc2; 572 struct in6_ifaddr *fdm; 573 struct in6_addr copia; 574 575 TAILQ_FOREACH(mdc, &ifnet, if_link) 576 TAILQ_FOREACH(mdc2, &mdc->if_addrlist, ifa_list) { 577 if (mdc2->ifa_addr->sa_family == AF_INET6) { 578 fdm = (struct in6_ifaddr *)mdc2; 579 copia = fdm->ia_addr.sin6_addr; 580 /* need for leaving scope_id in the sock_addr */ 581 in6_clearscope(&copia); 582 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) 583 return 1; 584 } 585 } 586 return 0; 587} 588 589static int 590verify_path6(struct in6_addr *src, struct ifnet *ifp) 591{ 592 struct route_in6 ro; 593 struct sockaddr_in6 *dst; 594 595 bzero(&ro, sizeof(ro)); 596 597 dst = (struct sockaddr_in6 * )&(ro.ro_dst); 598 dst->sin6_family = AF_INET6; 599 dst->sin6_len = sizeof(*dst); 600 dst->sin6_addr = *src; 601 rtalloc_ign((struct route *)&ro, RTF_CLONING); 602 603 if (ro.ro_rt == NULL) 604 return 0; 605 606 /* 607 * if ifp is provided, check for equality with rtentry 608 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 609 * to support the case of sending packets to an address of our own. 610 * (where the former interface is the first argument of if_simloop() 611 * (=ifp), the latter is lo0) 612 */ 613 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 614 RTFREE(ro.ro_rt); 615 return 0; 616 } 617 618 /* if no ifp provided, check if rtentry is not default route */ 619 if (ifp == NULL && 620 IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) { 621 RTFREE(ro.ro_rt); 622 return 0; 623 } 624 625 /* or if this is a blackhole/reject route */ 626 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 627 RTFREE(ro.ro_rt); 628 return 0; 629 } 630 631 /* found valid route */ 632 RTFREE(ro.ro_rt); 633 return 1; 634 635} 636static __inline int 637hash_packet6(struct ipfw_flow_id *id) 638{ 639 u_int32_t i; 640 i = (id->dst_ip6.__u6_addr.__u6_addr32[2]) ^ 641 (id->dst_ip6.__u6_addr.__u6_addr32[3]) ^ 642 (id->src_ip6.__u6_addr.__u6_addr32[2]) ^ 643 (id->src_ip6.__u6_addr.__u6_addr32[3]) ^ 644 (id->dst_port) ^ (id->src_port); 645 return i; 646} 647 648static int 649is_icmp6_query(int icmp6_type) 650{ 651 if ((icmp6_type <= ICMP6_MAXTYPE) && 652 (icmp6_type == ICMP6_ECHO_REQUEST || 653 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 654 icmp6_type == ICMP6_WRUREQUEST || 655 icmp6_type == ICMP6_FQDN_QUERY || 656 icmp6_type == ICMP6_NI_QUERY)) 657 return (1); 658 659 return (0); 660} 661 662static void 663send_reject6(struct ip_fw_args *args, int code, u_int hlen) 664{ 665 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 666 struct ip6_hdr *ip6; 667 struct tcphdr *tcp; 668 tcp_seq ack, seq; 669 int flags; 670 struct { 671 struct ip6_hdr ip6; 672 struct tcphdr th; 673 } ti; 674 675 if (args->m->m_len < (hlen+sizeof(struct tcphdr))) { 676 args->m = m_pullup(args->m, hlen+sizeof(struct tcphdr)); 677 if (args->m == NULL) 678 return; 679 } 680 681 ip6 = mtod(args->m, struct ip6_hdr *); 682 tcp = (struct tcphdr *)(mtod(args->m, char *) + hlen); 683 684 if ((tcp->th_flags & TH_RST) != 0) { 685 m_freem(args->m); 686 return; 687 } 688 689 ti.ip6 = *ip6; 690 ti.th = *tcp; 691 ti.th.th_seq = ntohl(ti.th.th_seq); 692 ti.th.th_ack = ntohl(ti.th.th_ack); 693 ti.ip6.ip6_nxt = IPPROTO_TCP; 694 695 if (ti.th.th_flags & TH_ACK) { 696 ack = 0; 697 seq = ti.th.th_ack; 698 flags = TH_RST; 699 } else { 700 ack = ti.th.th_seq; 701 if (((args->m)->m_flags & M_PKTHDR) != 0) { 702 ack += (args->m)->m_pkthdr.len - hlen 703 - (ti.th.th_off << 2); 704 } else if (ip6->ip6_plen) { 705 ack += ntohs(ip6->ip6_plen) + sizeof(*ip6) 706 - hlen - (ti.th.th_off << 2); 707 } else { 708 m_freem(args->m); 709 return; 710 } 711 if (tcp->th_flags & TH_SYN) 712 ack++; 713 seq = 0; 714 flags = TH_RST|TH_ACK; 715 } 716 bcopy(&ti, ip6, sizeof(ti)); 717 tcp_respond(NULL, ip6, (struct tcphdr *)(ip6 + 1), 718 args->m, ack, seq, flags); 719 720 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */ 721 icmp6_error(args->m, ICMP6_DST_UNREACH, code, 0); 722 723 } else 724 m_freem(args->m); 725 726 args->m = NULL; 727} 728 729#endif /* INET6 */ 730 731static u_int64_t norule_counter; /* counter for ipfw_log(NULL...) */ 732 733#define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0 734#define SNP(buf) buf, sizeof(buf) 735 736/* 737 * We enter here when we have a rule with O_LOG. 738 * XXX this function alone takes about 2Kbytes of code! 739 */ 740static void 741ipfw_log(struct ip_fw *f, u_int hlen, struct ip_fw_args *args, 742 struct mbuf *m, struct ifnet *oif, u_short offset, uint32_t tablearg) 743{ 744 struct ether_header *eh = args->eh; 745 char *action; 746 int limit_reached = 0; 747 char action2[40], proto[128], fragment[32]; 748 749 fragment[0] = '\0'; 750 proto[0] = '\0'; 751 752 if (f == NULL) { /* bogus pkt */ 753 if (verbose_limit != 0 && norule_counter >= verbose_limit) 754 return; 755 norule_counter++; 756 if (norule_counter == verbose_limit) 757 limit_reached = verbose_limit; 758 action = "Refuse"; 759 } else { /* O_LOG is the first action, find the real one */ 760 ipfw_insn *cmd = ACTION_PTR(f); 761 ipfw_insn_log *l = (ipfw_insn_log *)cmd; 762 763 if (l->max_log != 0 && l->log_left == 0) 764 return; 765 l->log_left--; 766 if (l->log_left == 0) 767 limit_reached = l->max_log; 768 cmd += F_LEN(cmd); /* point to first action */ 769 if (cmd->opcode == O_ALTQ) { 770 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 771 772 snprintf(SNPARGS(action2, 0), "Altq %d", 773 altq->qid); 774 cmd += F_LEN(cmd); 775 } 776 if (cmd->opcode == O_PROB) 777 cmd += F_LEN(cmd); 778 779 if (cmd->opcode == O_TAG) 780 cmd += F_LEN(cmd); 781 782 action = action2; 783 switch (cmd->opcode) { 784 case O_DENY: 785 action = "Deny"; 786 break; 787 788 case O_REJECT: 789 if (cmd->arg1==ICMP_REJECT_RST) 790 action = "Reset"; 791 else if (cmd->arg1==ICMP_UNREACH_HOST) 792 action = "Reject"; 793 else 794 snprintf(SNPARGS(action2, 0), "Unreach %d", 795 cmd->arg1); 796 break; 797 798 case O_UNREACH6: 799 if (cmd->arg1==ICMP6_UNREACH_RST) 800 action = "Reset"; 801 else 802 snprintf(SNPARGS(action2, 0), "Unreach %d", 803 cmd->arg1); 804 break; 805 806 case O_ACCEPT: 807 action = "Accept"; 808 break; 809 case O_COUNT: 810 action = "Count"; 811 break; 812 case O_DIVERT: 813 snprintf(SNPARGS(action2, 0), "Divert %d", 814 cmd->arg1); 815 break; 816 case O_TEE: 817 snprintf(SNPARGS(action2, 0), "Tee %d", 818 cmd->arg1); 819 break; 820 case O_SKIPTO: 821 snprintf(SNPARGS(action2, 0), "SkipTo %d", 822 cmd->arg1); 823 break; 824 case O_PIPE: 825 snprintf(SNPARGS(action2, 0), "Pipe %d", 826 cmd->arg1); 827 break; 828 case O_QUEUE: 829 snprintf(SNPARGS(action2, 0), "Queue %d", 830 cmd->arg1); 831 break; 832 case O_FORWARD_IP: { 833 ipfw_insn_sa *sa = (ipfw_insn_sa *)cmd; 834 int len; 835 struct in_addr dummyaddr; 836 if (sa->sa.sin_addr.s_addr == INADDR_ANY) 837 dummyaddr.s_addr = htonl(tablearg); 838 else 839 dummyaddr.s_addr = sa->sa.sin_addr.s_addr; 840 841 len = snprintf(SNPARGS(action2, 0), "Forward to %s", 842 inet_ntoa(dummyaddr)); 843 844 if (sa->sa.sin_port) 845 snprintf(SNPARGS(action2, len), ":%d", 846 sa->sa.sin_port); 847 } 848 break; 849 case O_NETGRAPH: 850 snprintf(SNPARGS(action2, 0), "Netgraph %d", 851 cmd->arg1); 852 break; 853 case O_NGTEE: 854 snprintf(SNPARGS(action2, 0), "Ngtee %d", 855 cmd->arg1); 856 break; 857 default: 858 action = "UNKNOWN"; 859 break; 860 } 861 } 862 863 if (hlen == 0) { /* non-ip */ 864 snprintf(SNPARGS(proto, 0), "MAC"); 865 866 } else { 867 int len; 868 char src[48], dst[48]; 869 struct icmphdr *icmp; 870 struct tcphdr *tcp; 871 struct udphdr *udp; 872 /* Initialize to make compiler happy. */ 873 struct ip *ip = NULL; 874#ifdef INET6 875 struct ip6_hdr *ip6 = NULL; 876 struct icmp6_hdr *icmp6; 877#endif 878 src[0] = '\0'; 879 dst[0] = '\0'; 880#ifdef INET6 881 if (args->f_id.addr_type == 6) { 882 snprintf(src, sizeof(src), "[%s]", 883 ip6_sprintf(&args->f_id.src_ip6)); 884 snprintf(dst, sizeof(dst), "[%s]", 885 ip6_sprintf(&args->f_id.dst_ip6)); 886 887 ip6 = (struct ip6_hdr *)mtod(m, struct ip6_hdr *); 888 tcp = (struct tcphdr *)(mtod(args->m, char *) + hlen); 889 udp = (struct udphdr *)(mtod(args->m, char *) + hlen); 890 } else 891#endif 892 { 893 ip = mtod(m, struct ip *); 894 tcp = L3HDR(struct tcphdr, ip); 895 udp = L3HDR(struct udphdr, ip); 896 897 inet_ntoa_r(ip->ip_src, src); 898 inet_ntoa_r(ip->ip_dst, dst); 899 } 900 901 switch (args->f_id.proto) { 902 case IPPROTO_TCP: 903 len = snprintf(SNPARGS(proto, 0), "TCP %s", src); 904 if (offset == 0) 905 snprintf(SNPARGS(proto, len), ":%d %s:%d", 906 ntohs(tcp->th_sport), 907 dst, 908 ntohs(tcp->th_dport)); 909 else 910 snprintf(SNPARGS(proto, len), " %s", dst); 911 break; 912 913 case IPPROTO_UDP: 914 len = snprintf(SNPARGS(proto, 0), "UDP %s", src); 915 if (offset == 0) 916 snprintf(SNPARGS(proto, len), ":%d %s:%d", 917 ntohs(udp->uh_sport), 918 dst, 919 ntohs(udp->uh_dport)); 920 else 921 snprintf(SNPARGS(proto, len), " %s", dst); 922 break; 923 924 case IPPROTO_ICMP: 925 icmp = L3HDR(struct icmphdr, ip); 926 if (offset == 0) 927 len = snprintf(SNPARGS(proto, 0), 928 "ICMP:%u.%u ", 929 icmp->icmp_type, icmp->icmp_code); 930 else 931 len = snprintf(SNPARGS(proto, 0), "ICMP "); 932 len += snprintf(SNPARGS(proto, len), "%s", src); 933 snprintf(SNPARGS(proto, len), " %s", dst); 934 break; 935#ifdef INET6 936 case IPPROTO_ICMPV6: 937 icmp6 = (struct icmp6_hdr *)(mtod(args->m, char *) + hlen); 938 if (offset == 0) 939 len = snprintf(SNPARGS(proto, 0), 940 "ICMPv6:%u.%u ", 941 icmp6->icmp6_type, icmp6->icmp6_code); 942 else 943 len = snprintf(SNPARGS(proto, 0), "ICMPv6 "); 944 len += snprintf(SNPARGS(proto, len), "%s", src); 945 snprintf(SNPARGS(proto, len), " %s", dst); 946 break; 947#endif 948 default: 949 len = snprintf(SNPARGS(proto, 0), "P:%d %s", 950 args->f_id.proto, src); 951 snprintf(SNPARGS(proto, len), " %s", dst); 952 break; 953 } 954 955#ifdef INET6 956 if (args->f_id.addr_type == 6) { 957 if (offset & (IP6F_OFF_MASK | IP6F_MORE_FRAG)) 958 snprintf(SNPARGS(fragment, 0), 959 " (frag %08x:%d@%d%s)", 960 args->f_id.frag_id6, 961 ntohs(ip6->ip6_plen) - hlen, 962 ntohs(offset & IP6F_OFF_MASK) << 3, 963 (offset & IP6F_MORE_FRAG) ? "+" : ""); 964 } else 965#endif 966 { 967 int ip_off, ip_len; 968 if (eh != NULL) { /* layer 2 packets are as on the wire */ 969 ip_off = ntohs(ip->ip_off); 970 ip_len = ntohs(ip->ip_len); 971 } else { 972 ip_off = ip->ip_off; 973 ip_len = ip->ip_len; 974 } 975 if (ip_off & (IP_MF | IP_OFFMASK)) 976 snprintf(SNPARGS(fragment, 0), 977 " (frag %d:%d@%d%s)", 978 ntohs(ip->ip_id), ip_len - (ip->ip_hl << 2), 979 offset << 3, 980 (ip_off & IP_MF) ? "+" : ""); 981 } 982 } 983 if (oif || m->m_pkthdr.rcvif) 984 log(LOG_SECURITY | LOG_INFO, 985 "ipfw: %d %s %s %s via %s%s\n", 986 f ? f->rulenum : -1, 987 action, proto, oif ? "out" : "in", 988 oif ? oif->if_xname : m->m_pkthdr.rcvif->if_xname, 989 fragment); 990 else 991 log(LOG_SECURITY | LOG_INFO, 992 "ipfw: %d %s %s [no if info]%s\n", 993 f ? f->rulenum : -1, 994 action, proto, fragment); 995 if (limit_reached) 996 log(LOG_SECURITY | LOG_NOTICE, 997 "ipfw: limit %d reached on entry %d\n", 998 limit_reached, f ? f->rulenum : -1); 999} 1000 1001/* 1002 * IMPORTANT: the hash function for dynamic rules must be commutative 1003 * in source and destination (ip,port), because rules are bidirectional 1004 * and we want to find both in the same bucket. 1005 */ 1006static __inline int 1007hash_packet(struct ipfw_flow_id *id) 1008{ 1009 u_int32_t i; 1010 1011#ifdef INET6 1012 if (IS_IP6_FLOW_ID(id)) 1013 i = hash_packet6(id); 1014 else 1015#endif /* INET6 */ 1016 i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port); 1017 i &= (curr_dyn_buckets - 1); 1018 return i; 1019} 1020 1021/** 1022 * unlink a dynamic rule from a chain. prev is a pointer to 1023 * the previous one, q is a pointer to the rule to delete, 1024 * head is a pointer to the head of the queue. 1025 * Modifies q and potentially also head. 1026 */ 1027#define UNLINK_DYN_RULE(prev, head, q) { \ 1028 ipfw_dyn_rule *old_q = q; \ 1029 \ 1030 /* remove a refcount to the parent */ \ 1031 if (q->dyn_type == O_LIMIT) \ 1032 q->parent->count--; \ 1033 DEB(printf("ipfw: unlink entry 0x%08x %d -> 0x%08x %d, %d left\n",\ 1034 (q->id.src_ip), (q->id.src_port), \ 1035 (q->id.dst_ip), (q->id.dst_port), dyn_count-1 ); ) \ 1036 if (prev != NULL) \ 1037 prev->next = q = q->next; \ 1038 else \ 1039 head = q = q->next; \ 1040 dyn_count--; \ 1041 uma_zfree(ipfw_dyn_rule_zone, old_q); } 1042 1043#define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0) 1044 1045/** 1046 * Remove dynamic rules pointing to "rule", or all of them if rule == NULL. 1047 * 1048 * If keep_me == NULL, rules are deleted even if not expired, 1049 * otherwise only expired rules are removed. 1050 * 1051 * The value of the second parameter is also used to point to identify 1052 * a rule we absolutely do not want to remove (e.g. because we are 1053 * holding a reference to it -- this is the case with O_LIMIT_PARENT 1054 * rules). The pointer is only used for comparison, so any non-null 1055 * value will do. 1056 */ 1057static void 1058remove_dyn_rule(struct ip_fw *rule, ipfw_dyn_rule *keep_me) 1059{ 1060 static u_int32_t last_remove = 0; 1061 1062#define FORCE (keep_me == NULL) 1063 1064 ipfw_dyn_rule *prev, *q; 1065 int i, pass = 0, max_pass = 0; 1066 1067 IPFW_DYN_LOCK_ASSERT(); 1068 1069 if (ipfw_dyn_v == NULL || dyn_count == 0) 1070 return; 1071 /* do not expire more than once per second, it is useless */ 1072 if (!FORCE && last_remove == time_uptime) 1073 return; 1074 last_remove = time_uptime; 1075 1076 /* 1077 * because O_LIMIT refer to parent rules, during the first pass only 1078 * remove child and mark any pending LIMIT_PARENT, and remove 1079 * them in a second pass. 1080 */ 1081next_pass: 1082 for (i = 0 ; i < curr_dyn_buckets ; i++) { 1083 for (prev=NULL, q = ipfw_dyn_v[i] ; q ; ) { 1084 /* 1085 * Logic can become complex here, so we split tests. 1086 */ 1087 if (q == keep_me) 1088 goto next; 1089 if (rule != NULL && rule != q->rule) 1090 goto next; /* not the one we are looking for */ 1091 if (q->dyn_type == O_LIMIT_PARENT) { 1092 /* 1093 * handle parent in the second pass, 1094 * record we need one. 1095 */ 1096 max_pass = 1; 1097 if (pass == 0) 1098 goto next; 1099 if (FORCE && q->count != 0 ) { 1100 /* XXX should not happen! */ 1101 printf("ipfw: OUCH! cannot remove rule," 1102 " count %d\n", q->count); 1103 } 1104 } else { 1105 if (!FORCE && 1106 !TIME_LEQ( q->expire, time_uptime )) 1107 goto next; 1108 } 1109 if (q->dyn_type != O_LIMIT_PARENT || !q->count) { 1110 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q); 1111 continue; 1112 } 1113next: 1114 prev=q; 1115 q=q->next; 1116 } 1117 } 1118 if (pass++ < max_pass) 1119 goto next_pass; 1120} 1121 1122 1123/** 1124 * lookup a dynamic rule. 1125 */ 1126static ipfw_dyn_rule * 1127lookup_dyn_rule_locked(struct ipfw_flow_id *pkt, int *match_direction, 1128 struct tcphdr *tcp) 1129{ 1130 /* 1131 * stateful ipfw extensions. 1132 * Lookup into dynamic session queue 1133 */ 1134#define MATCH_REVERSE 0 1135#define MATCH_FORWARD 1 1136#define MATCH_NONE 2 1137#define MATCH_UNKNOWN 3 1138 int i, dir = MATCH_NONE; 1139 ipfw_dyn_rule *prev, *q=NULL; 1140 1141 IPFW_DYN_LOCK_ASSERT(); 1142 1143 if (ipfw_dyn_v == NULL) 1144 goto done; /* not found */ 1145 i = hash_packet( pkt ); 1146 for (prev=NULL, q = ipfw_dyn_v[i] ; q != NULL ; ) { 1147 if (q->dyn_type == O_LIMIT_PARENT && q->count) 1148 goto next; 1149 if (TIME_LEQ( q->expire, time_uptime)) { /* expire entry */ 1150 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q); 1151 continue; 1152 } 1153 if (pkt->proto == q->id.proto && 1154 q->dyn_type != O_LIMIT_PARENT) { 1155 if (IS_IP6_FLOW_ID(pkt)) { 1156 if (IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1157 &(q->id.src_ip6)) && 1158 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1159 &(q->id.dst_ip6)) && 1160 pkt->src_port == q->id.src_port && 1161 pkt->dst_port == q->id.dst_port ) { 1162 dir = MATCH_FORWARD; 1163 break; 1164 } 1165 if (IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1166 &(q->id.dst_ip6)) && 1167 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1168 &(q->id.src_ip6)) && 1169 pkt->src_port == q->id.dst_port && 1170 pkt->dst_port == q->id.src_port ) { 1171 dir = MATCH_REVERSE; 1172 break; 1173 } 1174 } else { 1175 if (pkt->src_ip == q->id.src_ip && 1176 pkt->dst_ip == q->id.dst_ip && 1177 pkt->src_port == q->id.src_port && 1178 pkt->dst_port == q->id.dst_port ) { 1179 dir = MATCH_FORWARD; 1180 break; 1181 } 1182 if (pkt->src_ip == q->id.dst_ip && 1183 pkt->dst_ip == q->id.src_ip && 1184 pkt->src_port == q->id.dst_port && 1185 pkt->dst_port == q->id.src_port ) { 1186 dir = MATCH_REVERSE; 1187 break; 1188 } 1189 } 1190 } 1191next: 1192 prev = q; 1193 q = q->next; 1194 } 1195 if (q == NULL) 1196 goto done; /* q = NULL, not found */ 1197 1198 if ( prev != NULL) { /* found and not in front */ 1199 prev->next = q->next; 1200 q->next = ipfw_dyn_v[i]; 1201 ipfw_dyn_v[i] = q; 1202 } 1203 if (pkt->proto == IPPROTO_TCP) { /* update state according to flags */ 1204 u_char flags = pkt->flags & (TH_FIN|TH_SYN|TH_RST); 1205 1206#define BOTH_SYN (TH_SYN | (TH_SYN << 8)) 1207#define BOTH_FIN (TH_FIN | (TH_FIN << 8)) 1208 q->state |= (dir == MATCH_FORWARD ) ? flags : (flags << 8); 1209 switch (q->state) { 1210 case TH_SYN: /* opening */ 1211 q->expire = time_uptime + dyn_syn_lifetime; 1212 break; 1213 1214 case BOTH_SYN: /* move to established */ 1215 case BOTH_SYN | TH_FIN : /* one side tries to close */ 1216 case BOTH_SYN | (TH_FIN << 8) : 1217 if (tcp) { 1218#define _SEQ_GE(a,b) ((int)(a) - (int)(b) >= 0) 1219 u_int32_t ack = ntohl(tcp->th_ack); 1220 if (dir == MATCH_FORWARD) { 1221 if (q->ack_fwd == 0 || _SEQ_GE(ack, q->ack_fwd)) 1222 q->ack_fwd = ack; 1223 else { /* ignore out-of-sequence */ 1224 break; 1225 } 1226 } else { 1227 if (q->ack_rev == 0 || _SEQ_GE(ack, q->ack_rev)) 1228 q->ack_rev = ack; 1229 else { /* ignore out-of-sequence */ 1230 break; 1231 } 1232 } 1233 } 1234 q->expire = time_uptime + dyn_ack_lifetime; 1235 break; 1236 1237 case BOTH_SYN | BOTH_FIN: /* both sides closed */ 1238 if (dyn_fin_lifetime >= dyn_keepalive_period) 1239 dyn_fin_lifetime = dyn_keepalive_period - 1; 1240 q->expire = time_uptime + dyn_fin_lifetime; 1241 break; 1242 1243 default: 1244#if 0 1245 /* 1246 * reset or some invalid combination, but can also 1247 * occur if we use keep-state the wrong way. 1248 */ 1249 if ( (q->state & ((TH_RST << 8)|TH_RST)) == 0) 1250 printf("invalid state: 0x%x\n", q->state); 1251#endif 1252 if (dyn_rst_lifetime >= dyn_keepalive_period) 1253 dyn_rst_lifetime = dyn_keepalive_period - 1; 1254 q->expire = time_uptime + dyn_rst_lifetime; 1255 break; 1256 } 1257 } else if (pkt->proto == IPPROTO_UDP) { 1258 q->expire = time_uptime + dyn_udp_lifetime; 1259 } else { 1260 /* other protocols */ 1261 q->expire = time_uptime + dyn_short_lifetime; 1262 } 1263done: 1264 if (match_direction) 1265 *match_direction = dir; 1266 return q; 1267} 1268 1269static ipfw_dyn_rule * 1270lookup_dyn_rule(struct ipfw_flow_id *pkt, int *match_direction, 1271 struct tcphdr *tcp) 1272{ 1273 ipfw_dyn_rule *q; 1274 1275 IPFW_DYN_LOCK(); 1276 q = lookup_dyn_rule_locked(pkt, match_direction, tcp); 1277 if (q == NULL) 1278 IPFW_DYN_UNLOCK(); 1279 /* NB: return table locked when q is not NULL */ 1280 return q; 1281} 1282 1283static void 1284realloc_dynamic_table(void) 1285{ 1286 IPFW_DYN_LOCK_ASSERT(); 1287 1288 /* 1289 * Try reallocation, make sure we have a power of 2 and do 1290 * not allow more than 64k entries. In case of overflow, 1291 * default to 1024. 1292 */ 1293 1294 if (dyn_buckets > 65536) 1295 dyn_buckets = 1024; 1296 if ((dyn_buckets & (dyn_buckets-1)) != 0) { /* not a power of 2 */ 1297 dyn_buckets = curr_dyn_buckets; /* reset */ 1298 return; 1299 } 1300 curr_dyn_buckets = dyn_buckets; 1301 if (ipfw_dyn_v != NULL) 1302 free(ipfw_dyn_v, M_IPFW); 1303 for (;;) { 1304 ipfw_dyn_v = malloc(curr_dyn_buckets * sizeof(ipfw_dyn_rule *), 1305 M_IPFW, M_NOWAIT | M_ZERO); 1306 if (ipfw_dyn_v != NULL || curr_dyn_buckets <= 2) 1307 break; 1308 curr_dyn_buckets /= 2; 1309 } 1310} 1311 1312/** 1313 * Install state of type 'type' for a dynamic session. 1314 * The hash table contains two type of rules: 1315 * - regular rules (O_KEEP_STATE) 1316 * - rules for sessions with limited number of sess per user 1317 * (O_LIMIT). When they are created, the parent is 1318 * increased by 1, and decreased on delete. In this case, 1319 * the third parameter is the parent rule and not the chain. 1320 * - "parent" rules for the above (O_LIMIT_PARENT). 1321 */ 1322static ipfw_dyn_rule * 1323add_dyn_rule(struct ipfw_flow_id *id, u_int8_t dyn_type, struct ip_fw *rule) 1324{ 1325 ipfw_dyn_rule *r; 1326 int i; 1327 1328 IPFW_DYN_LOCK_ASSERT(); 1329 1330 if (ipfw_dyn_v == NULL || 1331 (dyn_count == 0 && dyn_buckets != curr_dyn_buckets)) { 1332 realloc_dynamic_table(); 1333 if (ipfw_dyn_v == NULL) 1334 return NULL; /* failed ! */ 1335 } 1336 i = hash_packet(id); 1337 1338 r = uma_zalloc(ipfw_dyn_rule_zone, M_NOWAIT | M_ZERO); 1339 if (r == NULL) { 1340 printf ("ipfw: sorry cannot allocate state\n"); 1341 return NULL; 1342 } 1343 1344 /* increase refcount on parent, and set pointer */ 1345 if (dyn_type == O_LIMIT) { 1346 ipfw_dyn_rule *parent = (ipfw_dyn_rule *)rule; 1347 if ( parent->dyn_type != O_LIMIT_PARENT) 1348 panic("invalid parent"); 1349 parent->count++; 1350 r->parent = parent; 1351 rule = parent->rule; 1352 } 1353 1354 r->id = *id; 1355 r->expire = time_uptime + dyn_syn_lifetime; 1356 r->rule = rule; 1357 r->dyn_type = dyn_type; 1358 r->pcnt = r->bcnt = 0; 1359 r->count = 0; 1360 1361 r->bucket = i; 1362 r->next = ipfw_dyn_v[i]; 1363 ipfw_dyn_v[i] = r; 1364 dyn_count++; 1365 DEB(printf("ipfw: add dyn entry ty %d 0x%08x %d -> 0x%08x %d, total %d\n", 1366 dyn_type, 1367 (r->id.src_ip), (r->id.src_port), 1368 (r->id.dst_ip), (r->id.dst_port), 1369 dyn_count ); ) 1370 return r; 1371} 1372 1373/** 1374 * lookup dynamic parent rule using pkt and rule as search keys. 1375 * If the lookup fails, then install one. 1376 */ 1377static ipfw_dyn_rule * 1378lookup_dyn_parent(struct ipfw_flow_id *pkt, struct ip_fw *rule) 1379{ 1380 ipfw_dyn_rule *q; 1381 int i; 1382 1383 IPFW_DYN_LOCK_ASSERT(); 1384 1385 if (ipfw_dyn_v) { 1386 int is_v6 = IS_IP6_FLOW_ID(pkt); 1387 i = hash_packet( pkt ); 1388 for (q = ipfw_dyn_v[i] ; q != NULL ; q=q->next) 1389 if (q->dyn_type == O_LIMIT_PARENT && 1390 rule== q->rule && 1391 pkt->proto == q->id.proto && 1392 pkt->src_port == q->id.src_port && 1393 pkt->dst_port == q->id.dst_port && 1394 ( 1395 (is_v6 && 1396 IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1397 &(q->id.src_ip6)) && 1398 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1399 &(q->id.dst_ip6))) || 1400 (!is_v6 && 1401 pkt->src_ip == q->id.src_ip && 1402 pkt->dst_ip == q->id.dst_ip) 1403 ) 1404 ) { 1405 q->expire = time_uptime + dyn_short_lifetime; 1406 DEB(printf("ipfw: lookup_dyn_parent found 0x%p\n",q);) 1407 return q; 1408 } 1409 } 1410 return add_dyn_rule(pkt, O_LIMIT_PARENT, rule); 1411} 1412 1413/** 1414 * Install dynamic state for rule type cmd->o.opcode 1415 * 1416 * Returns 1 (failure) if state is not installed because of errors or because 1417 * session limitations are enforced. 1418 */ 1419static int 1420install_state(struct ip_fw *rule, ipfw_insn_limit *cmd, 1421 struct ip_fw_args *args, uint32_t tablearg) 1422{ 1423 static int last_log; 1424 1425 ipfw_dyn_rule *q; 1426 1427 DEB( 1428 printf("ipfw: %s: type %d 0x%08x %u -> 0x%08x %u\n", 1429 __func__, cmd->o.opcode, 1430 (args->f_id.src_ip), (args->f_id.src_port), 1431 (args->f_id.dst_ip), (args->f_id.dst_port)); 1432 ) 1433 1434 IPFW_DYN_LOCK(); 1435 1436 q = lookup_dyn_rule_locked(&args->f_id, NULL, NULL); 1437 1438 if (q != NULL) { /* should never occur */ 1439 if (last_log != time_uptime) { 1440 last_log = time_uptime; 1441 printf("ipfw: %s: entry already present, done\n", 1442 __func__); 1443 } 1444 IPFW_DYN_UNLOCK(); 1445 return (0); 1446 } 1447 1448 if (dyn_count >= dyn_max) 1449 /* Run out of slots, try to remove any expired rule. */ 1450 remove_dyn_rule(NULL, (ipfw_dyn_rule *)1); 1451 1452 if (dyn_count >= dyn_max) { 1453 if (last_log != time_uptime) { 1454 last_log = time_uptime; 1455 printf("ipfw: %s: Too many dynamic rules\n", __func__); 1456 } 1457 IPFW_DYN_UNLOCK(); 1458 return (1); /* cannot install, notify caller */ 1459 } 1460 1461 switch (cmd->o.opcode) { 1462 case O_KEEP_STATE: /* bidir rule */ 1463 add_dyn_rule(&args->f_id, O_KEEP_STATE, rule); 1464 break; 1465 1466 case O_LIMIT: { /* limit number of sessions */ 1467 struct ipfw_flow_id id; 1468 ipfw_dyn_rule *parent; 1469 uint32_t conn_limit; 1470 uint16_t limit_mask = cmd->limit_mask; 1471 1472 conn_limit = (cmd->conn_limit == IP_FW_TABLEARG) ? 1473 tablearg : cmd->conn_limit; 1474 1475 DEB( 1476 if (cmd->conn_limit == IP_FW_TABLEARG) 1477 printf("ipfw: %s: O_LIMIT rule, conn_limit: %u " 1478 "(tablearg)\n", __func__, conn_limit); 1479 else 1480 printf("ipfw: %s: O_LIMIT rule, conn_limit: %u\n", 1481 __func__, conn_limit); 1482 ) 1483 1484 id.dst_ip = id.src_ip = id.dst_port = id.src_port = 0; 1485 id.proto = args->f_id.proto; 1486 id.addr_type = args->f_id.addr_type; 1487 1488 if (IS_IP6_FLOW_ID (&(args->f_id))) { 1489 if (limit_mask & DYN_SRC_ADDR) 1490 id.src_ip6 = args->f_id.src_ip6; 1491 if (limit_mask & DYN_DST_ADDR) 1492 id.dst_ip6 = args->f_id.dst_ip6; 1493 } else { 1494 if (limit_mask & DYN_SRC_ADDR) 1495 id.src_ip = args->f_id.src_ip; 1496 if (limit_mask & DYN_DST_ADDR) 1497 id.dst_ip = args->f_id.dst_ip; 1498 } 1499 if (limit_mask & DYN_SRC_PORT) 1500 id.src_port = args->f_id.src_port; 1501 if (limit_mask & DYN_DST_PORT) 1502 id.dst_port = args->f_id.dst_port; 1503 if ((parent = lookup_dyn_parent(&id, rule)) == NULL) { 1504 printf("ipfw: %s: add parent failed\n", __func__); 1505 IPFW_DYN_UNLOCK(); 1506 return (1); 1507 } 1508 1509 if (parent->count >= conn_limit) { 1510 /* See if we can remove some expired rule. */ 1511 remove_dyn_rule(rule, parent); 1512 if (parent->count >= conn_limit) { 1513 if (fw_verbose && last_log != time_uptime) { 1514 last_log = time_uptime; 1515 log(LOG_SECURITY | LOG_DEBUG, 1516 "drop session, too many entries\n"); 1517 } 1518 IPFW_DYN_UNLOCK(); 1519 return (1); 1520 } 1521 } 1522 add_dyn_rule(&args->f_id, O_LIMIT, (struct ip_fw *)parent); 1523 break; 1524 } 1525 default: 1526 printf("ipfw: %s: unknown dynamic rule type %u\n", 1527 __func__, cmd->o.opcode); 1528 IPFW_DYN_UNLOCK(); 1529 return (1); 1530 } 1531 1532 /* XXX just set lifetime */ 1533 lookup_dyn_rule_locked(&args->f_id, NULL, NULL); 1534 1535 IPFW_DYN_UNLOCK(); 1536 return (0); 1537} 1538 1539/* 1540 * Generate a TCP packet, containing either a RST or a keepalive. 1541 * When flags & TH_RST, we are sending a RST packet, because of a 1542 * "reset" action matched the packet. 1543 * Otherwise we are sending a keepalive, and flags & TH_ 1544 */ 1545static struct mbuf * 1546send_pkt(struct ipfw_flow_id *id, u_int32_t seq, u_int32_t ack, int flags) 1547{ 1548 struct mbuf *m; 1549 struct ip *ip; 1550 struct tcphdr *tcp; 1551 1552 MGETHDR(m, M_DONTWAIT, MT_DATA); 1553 if (m == 0) 1554 return (NULL); 1555 m->m_pkthdr.rcvif = (struct ifnet *)0; 1556 m->m_pkthdr.len = m->m_len = sizeof(struct ip) + sizeof(struct tcphdr); 1557 m->m_data += max_linkhdr; 1558 1559 ip = mtod(m, struct ip *); 1560 bzero(ip, m->m_len); 1561 tcp = (struct tcphdr *)(ip + 1); /* no IP options */ 1562 ip->ip_p = IPPROTO_TCP; 1563 tcp->th_off = 5; 1564 /* 1565 * Assume we are sending a RST (or a keepalive in the reverse 1566 * direction), swap src and destination addresses and ports. 1567 */ 1568 ip->ip_src.s_addr = htonl(id->dst_ip); 1569 ip->ip_dst.s_addr = htonl(id->src_ip); 1570 tcp->th_sport = htons(id->dst_port); 1571 tcp->th_dport = htons(id->src_port); 1572 if (flags & TH_RST) { /* we are sending a RST */ 1573 if (flags & TH_ACK) { 1574 tcp->th_seq = htonl(ack); 1575 tcp->th_ack = htonl(0); 1576 tcp->th_flags = TH_RST; 1577 } else { 1578 if (flags & TH_SYN) 1579 seq++; 1580 tcp->th_seq = htonl(0); 1581 tcp->th_ack = htonl(seq); 1582 tcp->th_flags = TH_RST | TH_ACK; 1583 } 1584 } else { 1585 /* 1586 * We are sending a keepalive. flags & TH_SYN determines 1587 * the direction, forward if set, reverse if clear. 1588 * NOTE: seq and ack are always assumed to be correct 1589 * as set by the caller. This may be confusing... 1590 */ 1591 if (flags & TH_SYN) { 1592 /* 1593 * we have to rewrite the correct addresses! 1594 */ 1595 ip->ip_dst.s_addr = htonl(id->dst_ip); 1596 ip->ip_src.s_addr = htonl(id->src_ip); 1597 tcp->th_dport = htons(id->dst_port); 1598 tcp->th_sport = htons(id->src_port); 1599 } 1600 tcp->th_seq = htonl(seq); 1601 tcp->th_ack = htonl(ack); 1602 tcp->th_flags = TH_ACK; 1603 } 1604 /* 1605 * set ip_len to the payload size so we can compute 1606 * the tcp checksum on the pseudoheader 1607 * XXX check this, could save a couple of words ? 1608 */ 1609 ip->ip_len = htons(sizeof(struct tcphdr)); 1610 tcp->th_sum = in_cksum(m, m->m_pkthdr.len); 1611 /* 1612 * now fill fields left out earlier 1613 */ 1614 ip->ip_ttl = ip_defttl; 1615 ip->ip_len = m->m_pkthdr.len; 1616 m->m_flags |= M_SKIP_FIREWALL; 1617 return (m); 1618} 1619 1620/* 1621 * sends a reject message, consuming the mbuf passed as an argument. 1622 */ 1623static void 1624send_reject(struct ip_fw_args *args, int code, int ip_len) 1625{ 1626 1627 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */ 1628 /* We need the IP header in host order for icmp_error(). */ 1629 if (args->eh != NULL) { 1630 struct ip *ip = mtod(args->m, struct ip *); 1631 ip->ip_len = ntohs(ip->ip_len); 1632 ip->ip_off = ntohs(ip->ip_off); 1633 } 1634 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 1635 } else if (args->f_id.proto == IPPROTO_TCP) { 1636 struct tcphdr *const tcp = 1637 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 1638 if ( (tcp->th_flags & TH_RST) == 0) { 1639 struct mbuf *m; 1640 m = send_pkt(&(args->f_id), ntohl(tcp->th_seq), 1641 ntohl(tcp->th_ack), 1642 tcp->th_flags | TH_RST); 1643 if (m != NULL) 1644 ip_output(m, NULL, NULL, 0, NULL, NULL); 1645 } 1646 m_freem(args->m); 1647 } else 1648 m_freem(args->m); 1649 args->m = NULL; 1650} 1651 1652/** 1653 * 1654 * Given an ip_fw *, lookup_next_rule will return a pointer 1655 * to the next rule, which can be either the jump 1656 * target (for skipto instructions) or the next one in the list (in 1657 * all other cases including a missing jump target). 1658 * The result is also written in the "next_rule" field of the rule. 1659 * Backward jumps are not allowed, so start looking from the next 1660 * rule... 1661 * 1662 * This never returns NULL -- in case we do not have an exact match, 1663 * the next rule is returned. When the ruleset is changed, 1664 * pointers are flushed so we are always correct. 1665 */ 1666 1667static struct ip_fw * 1668lookup_next_rule(struct ip_fw *me) 1669{ 1670 struct ip_fw *rule = NULL; 1671 ipfw_insn *cmd; 1672 1673 /* look for action, in case it is a skipto */ 1674 cmd = ACTION_PTR(me); 1675 if (cmd->opcode == O_LOG) 1676 cmd += F_LEN(cmd); 1677 if (cmd->opcode == O_ALTQ) 1678 cmd += F_LEN(cmd); 1679 if (cmd->opcode == O_TAG) 1680 cmd += F_LEN(cmd); 1681 if ( cmd->opcode == O_SKIPTO ) 1682 for (rule = me->next; rule ; rule = rule->next) 1683 if (rule->rulenum >= cmd->arg1) 1684 break; 1685 if (rule == NULL) /* failure or not a skipto */ 1686 rule = me->next; 1687 me->next_rule = rule; 1688 return rule; 1689} 1690 1691static int 1692add_table_entry(struct ip_fw_chain *ch, uint16_t tbl, in_addr_t addr, 1693 uint8_t mlen, uint32_t value) 1694{ 1695 struct radix_node_head *rnh; 1696 struct table_entry *ent; 1697 1698 if (tbl >= IPFW_TABLES_MAX) 1699 return (EINVAL); 1700 rnh = ch->tables[tbl]; 1701 ent = malloc(sizeof(*ent), M_IPFW_TBL, M_NOWAIT | M_ZERO); 1702 if (ent == NULL) 1703 return (ENOMEM); 1704 ent->value = value; 1705 ent->addr.sin_len = ent->mask.sin_len = 8; 1706 ent->mask.sin_addr.s_addr = htonl(mlen ? ~((1 << (32 - mlen)) - 1) : 0); 1707 ent->addr.sin_addr.s_addr = addr & ent->mask.sin_addr.s_addr; 1708 IPFW_WLOCK(&layer3_chain); 1709 if (rnh->rnh_addaddr(&ent->addr, &ent->mask, rnh, (void *)ent) == 1710 NULL) { 1711 IPFW_WUNLOCK(&layer3_chain); 1712 free(ent, M_IPFW_TBL); 1713 return (EEXIST); 1714 } 1715 IPFW_WUNLOCK(&layer3_chain); 1716 return (0); 1717} 1718 1719static int 1720del_table_entry(struct ip_fw_chain *ch, uint16_t tbl, in_addr_t addr, 1721 uint8_t mlen) 1722{ 1723 struct radix_node_head *rnh; 1724 struct table_entry *ent; 1725 struct sockaddr_in sa, mask; 1726 1727 if (tbl >= IPFW_TABLES_MAX) 1728 return (EINVAL); 1729 rnh = ch->tables[tbl]; 1730 sa.sin_len = mask.sin_len = 8; 1731 mask.sin_addr.s_addr = htonl(mlen ? ~((1 << (32 - mlen)) - 1) : 0); 1732 sa.sin_addr.s_addr = addr & mask.sin_addr.s_addr; 1733 IPFW_WLOCK(ch); 1734 ent = (struct table_entry *)rnh->rnh_deladdr(&sa, &mask, rnh); 1735 if (ent == NULL) { 1736 IPFW_WUNLOCK(ch); 1737 return (ESRCH); 1738 } 1739 IPFW_WUNLOCK(ch); 1740 free(ent, M_IPFW_TBL); 1741 return (0); 1742} 1743 1744static int 1745flush_table_entry(struct radix_node *rn, void *arg) 1746{ 1747 struct radix_node_head * const rnh = arg; 1748 struct table_entry *ent; 1749 1750 ent = (struct table_entry *) 1751 rnh->rnh_deladdr(rn->rn_key, rn->rn_mask, rnh); 1752 if (ent != NULL) 1753 free(ent, M_IPFW_TBL); 1754 return (0); 1755} 1756 1757static int 1758flush_table(struct ip_fw_chain *ch, uint16_t tbl) 1759{ 1760 struct radix_node_head *rnh; 1761 1762 IPFW_WLOCK_ASSERT(ch); 1763 1764 if (tbl >= IPFW_TABLES_MAX) 1765 return (EINVAL); 1766 rnh = ch->tables[tbl]; 1767 KASSERT(rnh != NULL, ("NULL IPFW table")); 1768 rnh->rnh_walktree(rnh, flush_table_entry, rnh); 1769 return (0); 1770} 1771 1772static void 1773flush_tables(struct ip_fw_chain *ch) 1774{ 1775 uint16_t tbl; 1776 1777 IPFW_WLOCK_ASSERT(ch); 1778 1779 for (tbl = 0; tbl < IPFW_TABLES_MAX; tbl++) 1780 flush_table(ch, tbl); 1781} 1782 1783static int 1784init_tables(struct ip_fw_chain *ch) 1785{ 1786 int i; 1787 uint16_t j; 1788 1789 for (i = 0; i < IPFW_TABLES_MAX; i++) { 1790 if (!rn_inithead((void **)&ch->tables[i], 32)) { 1791 for (j = 0; j < i; j++) { 1792 (void) flush_table(ch, j); 1793 } 1794 return (ENOMEM); 1795 } 1796 } 1797 return (0); 1798} 1799 1800static int 1801lookup_table(struct ip_fw_chain *ch, uint16_t tbl, in_addr_t addr, 1802 uint32_t *val) 1803{ 1804 struct radix_node_head *rnh; 1805 struct table_entry *ent; 1806 struct sockaddr_in sa; 1807 1808 if (tbl >= IPFW_TABLES_MAX) 1809 return (0); 1810 rnh = ch->tables[tbl]; 1811 sa.sin_len = 8; 1812 sa.sin_addr.s_addr = addr; 1813 ent = (struct table_entry *)(rnh->rnh_lookup(&sa, NULL, rnh)); 1814 if (ent != NULL) { 1815 *val = ent->value; 1816 return (1); 1817 } 1818 return (0); 1819} 1820 1821static int 1822count_table_entry(struct radix_node *rn, void *arg) 1823{ 1824 u_int32_t * const cnt = arg; 1825 1826 (*cnt)++; 1827 return (0); 1828} 1829 1830static int 1831count_table(struct ip_fw_chain *ch, uint32_t tbl, uint32_t *cnt) 1832{ 1833 struct radix_node_head *rnh; 1834 1835 if (tbl >= IPFW_TABLES_MAX) 1836 return (EINVAL); 1837 rnh = ch->tables[tbl]; 1838 *cnt = 0; 1839 rnh->rnh_walktree(rnh, count_table_entry, cnt); 1840 return (0); 1841} 1842 1843static int 1844dump_table_entry(struct radix_node *rn, void *arg) 1845{ 1846 struct table_entry * const n = (struct table_entry *)rn; 1847 ipfw_table * const tbl = arg; 1848 ipfw_table_entry *ent; 1849 1850 if (tbl->cnt == tbl->size) 1851 return (1); 1852 ent = &tbl->ent[tbl->cnt]; 1853 ent->tbl = tbl->tbl; 1854 if (in_nullhost(n->mask.sin_addr)) 1855 ent->masklen = 0; 1856 else 1857 ent->masklen = 33 - ffs(ntohl(n->mask.sin_addr.s_addr)); 1858 ent->addr = n->addr.sin_addr.s_addr; 1859 ent->value = n->value; 1860 tbl->cnt++; 1861 return (0); 1862} 1863 1864static int 1865dump_table(struct ip_fw_chain *ch, ipfw_table *tbl) 1866{ 1867 struct radix_node_head *rnh; 1868 1869 if (tbl->tbl >= IPFW_TABLES_MAX) 1870 return (EINVAL); 1871 rnh = ch->tables[tbl->tbl]; 1872 tbl->cnt = 0; 1873 rnh->rnh_walktree(rnh, dump_table_entry, tbl); 1874 return (0); 1875} 1876 1877static void 1878fill_ugid_cache(struct inpcb *inp, struct ip_fw_ugid *ugp) 1879{ 1880 struct ucred *cr; 1881 1882 if (inp->inp_socket != NULL) { 1883 cr = inp->inp_socket->so_cred; 1884 ugp->fw_prid = jailed(cr) ? 1885 cr->cr_prison->pr_id : -1; 1886 ugp->fw_uid = cr->cr_uid; 1887 ugp->fw_ngroups = cr->cr_ngroups; 1888 bcopy(cr->cr_groups, ugp->fw_groups, 1889 sizeof(ugp->fw_groups)); 1890 } 1891} 1892 1893static int 1894check_uidgid(ipfw_insn_u32 *insn, 1895 int proto, struct ifnet *oif, 1896 struct in_addr dst_ip, u_int16_t dst_port, 1897 struct in_addr src_ip, u_int16_t src_port, 1898 struct ip_fw_ugid *ugp, int *lookup, struct inpcb *inp) 1899{ 1900 struct inpcbinfo *pi; 1901 int wildcard; 1902 struct inpcb *pcb; 1903 int match; 1904 gid_t *gp; 1905 1906 /* 1907 * Check to see if the UDP or TCP stack supplied us with 1908 * the PCB. If so, rather then holding a lock and looking 1909 * up the PCB, we can use the one that was supplied. 1910 */ 1911 if (inp && *lookup == 0) { 1912 INP_LOCK_ASSERT(inp); 1913 if (inp->inp_socket != NULL) { 1914 fill_ugid_cache(inp, ugp); 1915 *lookup = 1; 1916 } 1917 } 1918 /* 1919 * If we have already been here and the packet has no 1920 * PCB entry associated with it, then we can safely 1921 * assume that this is a no match. 1922 */ 1923 if (*lookup == -1) 1924 return (0); 1925 if (proto == IPPROTO_TCP) { 1926 wildcard = 0; 1927 pi = &tcbinfo; 1928 } else if (proto == IPPROTO_UDP) { 1929 wildcard = INPLOOKUP_WILDCARD; 1930 pi = &udbinfo; 1931 } else 1932 return 0; 1933 match = 0; 1934 if (*lookup == 0) { 1935 INP_INFO_RLOCK(pi); 1936 pcb = (oif) ? 1937 in_pcblookup_hash(pi, 1938 dst_ip, htons(dst_port), 1939 src_ip, htons(src_port), 1940 wildcard, oif) : 1941 in_pcblookup_hash(pi, 1942 src_ip, htons(src_port), 1943 dst_ip, htons(dst_port), 1944 wildcard, NULL); 1945 if (pcb != NULL) { 1946 INP_LOCK(pcb); 1947 if (pcb->inp_socket != NULL) { 1948 fill_ugid_cache(pcb, ugp); 1949 *lookup = 1; 1950 } 1951 INP_UNLOCK(pcb); 1952 } 1953 INP_INFO_RUNLOCK(pi); 1954 if (*lookup == 0) { 1955 /* 1956 * If the lookup did not yield any results, there 1957 * is no sense in coming back and trying again. So 1958 * we can set lookup to -1 and ensure that we wont 1959 * bother the pcb system again. 1960 */ 1961 *lookup = -1; 1962 return (0); 1963 } 1964 } 1965 if (insn->o.opcode == O_UID) 1966 match = (ugp->fw_uid == (uid_t)insn->d[0]); 1967 else if (insn->o.opcode == O_GID) { 1968 for (gp = ugp->fw_groups; 1969 gp < &ugp->fw_groups[ugp->fw_ngroups]; gp++) 1970 if (*gp == (gid_t)insn->d[0]) { 1971 match = 1; 1972 break; 1973 } 1974 } else if (insn->o.opcode == O_JAIL) 1975 match = (ugp->fw_prid == (int)insn->d[0]); 1976 return match; 1977} 1978 1979/* 1980 * The main check routine for the firewall. 1981 * 1982 * All arguments are in args so we can modify them and return them 1983 * back to the caller. 1984 * 1985 * Parameters: 1986 * 1987 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 1988 * Starts with the IP header. 1989 * args->eh (in) Mac header if present, or NULL for layer3 packet. 1990 * args->oif Outgoing interface, or NULL if packet is incoming. 1991 * The incoming interface is in the mbuf. (in) 1992 * args->divert_rule (in/out) 1993 * Skip up to the first rule past this rule number; 1994 * upon return, non-zero port number for divert or tee. 1995 * 1996 * args->rule Pointer to the last matching rule (in/out) 1997 * args->next_hop Socket we are forwarding to (out). 1998 * args->f_id Addresses grabbed from the packet (out) 1999 * args->cookie a cookie depending on rule action 2000 * 2001 * Return value: 2002 * 2003 * IP_FW_PASS the packet must be accepted 2004 * IP_FW_DENY the packet must be dropped 2005 * IP_FW_DIVERT divert packet, port in m_tag 2006 * IP_FW_TEE tee packet, port in m_tag 2007 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 2008 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 2009 * 2010 */ 2011 2012int 2013ipfw_chk(struct ip_fw_args *args) 2014{ 2015 /* 2016 * Local variables hold state during the processing of a packet. 2017 * 2018 * IMPORTANT NOTE: to speed up the processing of rules, there 2019 * are some assumption on the values of the variables, which 2020 * are documented here. Should you change them, please check 2021 * the implementation of the various instructions to make sure 2022 * that they still work. 2023 * 2024 * args->eh The MAC header. It is non-null for a layer2 2025 * packet, it is NULL for a layer-3 packet. 2026 * 2027 * m | args->m Pointer to the mbuf, as received from the caller. 2028 * It may change if ipfw_chk() does an m_pullup, or if it 2029 * consumes the packet because it calls send_reject(). 2030 * XXX This has to change, so that ipfw_chk() never modifies 2031 * or consumes the buffer. 2032 * ip is simply an alias of the value of m, and it is kept 2033 * in sync with it (the packet is supposed to start with 2034 * the ip header). 2035 */ 2036 struct mbuf *m = args->m; 2037 struct ip *ip = mtod(m, struct ip *); 2038 2039 /* 2040 * For rules which contain uid/gid or jail constraints, cache 2041 * a copy of the users credentials after the pcb lookup has been 2042 * executed. This will speed up the processing of rules with 2043 * these types of constraints, as well as decrease contention 2044 * on pcb related locks. 2045 */ 2046 struct ip_fw_ugid fw_ugid_cache; 2047 int ugid_lookup = 0; 2048 2049 /* 2050 * divinput_flags If non-zero, set to the IP_FW_DIVERT_*_FLAG 2051 * associated with a packet input on a divert socket. This 2052 * will allow to distinguish traffic and its direction when 2053 * it originates from a divert socket. 2054 */ 2055 u_int divinput_flags = 0; 2056 2057 /* 2058 * oif | args->oif If NULL, ipfw_chk has been called on the 2059 * inbound path (ether_input, ip_input). 2060 * If non-NULL, ipfw_chk has been called on the outbound path 2061 * (ether_output, ip_output). 2062 */ 2063 struct ifnet *oif = args->oif; 2064 2065 struct ip_fw *f = NULL; /* matching rule */ 2066 int retval = 0; 2067 2068 /* 2069 * hlen The length of the IP header. 2070 */ 2071 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 2072 2073 /* 2074 * offset The offset of a fragment. offset != 0 means that 2075 * we have a fragment at this offset of an IPv4 packet. 2076 * offset == 0 means that (if this is an IPv4 packet) 2077 * this is the first or only fragment. 2078 * For IPv6 offset == 0 means there is no Fragment Header. 2079 * If offset != 0 for IPv6 always use correct mask to 2080 * get the correct offset because we add IP6F_MORE_FRAG 2081 * to be able to dectect the first fragment which would 2082 * otherwise have offset = 0. 2083 */ 2084 u_short offset = 0; 2085 2086 /* 2087 * Local copies of addresses. They are only valid if we have 2088 * an IP packet. 2089 * 2090 * proto The protocol. Set to 0 for non-ip packets, 2091 * or to the protocol read from the packet otherwise. 2092 * proto != 0 means that we have an IPv4 packet. 2093 * 2094 * src_port, dst_port port numbers, in HOST format. Only 2095 * valid for TCP and UDP packets. 2096 * 2097 * src_ip, dst_ip ip addresses, in NETWORK format. 2098 * Only valid for IPv4 packets. 2099 */ 2100 u_int8_t proto; 2101 u_int16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 2102 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 2103 u_int16_t ip_len=0; 2104 int pktlen; 2105 2106 /* 2107 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 2108 * MATCH_NONE when checked and not matched (q = NULL), 2109 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) 2110 */ 2111 int dyn_dir = MATCH_UNKNOWN; 2112 ipfw_dyn_rule *q = NULL; 2113 struct ip_fw_chain *chain = &layer3_chain; 2114 struct m_tag *mtag; 2115 2116 /* 2117 * We store in ulp a pointer to the upper layer protocol header. 2118 * In the ipv4 case this is easy to determine from the header, 2119 * but for ipv6 we might have some additional headers in the middle. 2120 * ulp is NULL if not found. 2121 */ 2122 void *ulp = NULL; /* upper layer protocol pointer. */ 2123 /* XXX ipv6 variables */ 2124 int is_ipv6 = 0; 2125 u_int16_t ext_hd = 0; /* bits vector for extension header filtering */ 2126 /* end of ipv6 variables */ 2127 int is_ipv4 = 0; 2128 2129 if (m->m_flags & M_SKIP_FIREWALL) 2130 return (IP_FW_PASS); /* accept */ 2131 2132 pktlen = m->m_pkthdr.len; 2133 proto = args->f_id.proto = 0; /* mark f_id invalid */ 2134 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ 2135 2136/* 2137 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 2138 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 2139 * pointer might become stale after other pullups (but we never use it 2140 * this way). 2141 */ 2142#define PULLUP_TO(len, p, T) \ 2143do { \ 2144 int x = (len) + sizeof(T); \ 2145 if ((m)->m_len < x) { \ 2146 args->m = m = m_pullup(m, x); \ 2147 if (m == NULL) \ 2148 goto pullup_failed; \ 2149 } \ 2150 p = (mtod(m, char *) + (len)); \ 2151} while (0) 2152 2153 /* Identify IP packets and fill up variables. */ 2154 if (pktlen >= sizeof(struct ip6_hdr) && 2155 (args->eh == NULL || ntohs(args->eh->ether_type)==ETHERTYPE_IPV6) && 2156 mtod(m, struct ip *)->ip_v == 6) { 2157 is_ipv6 = 1; 2158 args->f_id.addr_type = 6; 2159 hlen = sizeof(struct ip6_hdr); 2160 proto = mtod(m, struct ip6_hdr *)->ip6_nxt; 2161 2162 /* Search extension headers to find upper layer protocols */ 2163 while (ulp == NULL) { 2164 switch (proto) { 2165 case IPPROTO_ICMPV6: 2166 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 2167 args->f_id.flags = ICMP6(ulp)->icmp6_type; 2168 break; 2169 2170 case IPPROTO_TCP: 2171 PULLUP_TO(hlen, ulp, struct tcphdr); 2172 dst_port = TCP(ulp)->th_dport; 2173 src_port = TCP(ulp)->th_sport; 2174 args->f_id.flags = TCP(ulp)->th_flags; 2175 break; 2176 2177 case IPPROTO_UDP: 2178 PULLUP_TO(hlen, ulp, struct udphdr); 2179 dst_port = UDP(ulp)->uh_dport; 2180 src_port = UDP(ulp)->uh_sport; 2181 break; 2182 2183 case IPPROTO_HOPOPTS: /* RFC 2460 */ 2184 PULLUP_TO(hlen, ulp, struct ip6_hbh); 2185 ext_hd |= EXT_HOPOPTS; 2186 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 2187 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 2188 ulp = NULL; 2189 break; 2190 2191 case IPPROTO_ROUTING: /* RFC 2460 */ 2192 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 2193 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 2194 case 0: 2195 break; 2196 default: 2197 printf("IPFW2: IPV6 - Unknown Routing " 2198 "Header type(%d)\n", 2199 ((struct ip6_rthdr *)ulp)->ip6r_type); 2200 if (fw_deny_unknown_exthdrs) 2201 return (IP_FW_DENY); 2202 break; 2203 } 2204 ext_hd |= EXT_ROUTING; 2205 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 2206 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 2207 ulp = NULL; 2208 break; 2209 2210 case IPPROTO_FRAGMENT: /* RFC 2460 */ 2211 PULLUP_TO(hlen, ulp, struct ip6_frag); 2212 ext_hd |= EXT_FRAGMENT; 2213 hlen += sizeof (struct ip6_frag); 2214 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 2215 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 2216 IP6F_OFF_MASK; 2217 /* Add IP6F_MORE_FRAG for offset of first 2218 * fragment to be != 0. */ 2219 offset |= ((struct ip6_frag *)ulp)->ip6f_offlg & 2220 IP6F_MORE_FRAG; 2221 if (offset == 0) { 2222 printf("IPFW2: IPV6 - Invalid Fragment " 2223 "Header\n"); 2224 if (fw_deny_unknown_exthdrs) 2225 return (IP_FW_DENY); 2226 break; 2227 } 2228 args->f_id.frag_id6 = 2229 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 2230 ulp = NULL; 2231 break; 2232 2233 case IPPROTO_DSTOPTS: /* RFC 2460 */ 2234 PULLUP_TO(hlen, ulp, struct ip6_hbh); 2235 ext_hd |= EXT_DSTOPTS; 2236 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 2237 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 2238 ulp = NULL; 2239 break; 2240 2241 case IPPROTO_AH: /* RFC 2402 */ 2242 PULLUP_TO(hlen, ulp, struct ip6_ext); 2243 ext_hd |= EXT_AH; 2244 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 2245 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 2246 ulp = NULL; 2247 break; 2248 2249 case IPPROTO_ESP: /* RFC 2406 */ 2250 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 2251 /* Anything past Seq# is variable length and 2252 * data past this ext. header is encrypted. */ 2253 ext_hd |= EXT_ESP; 2254 break; 2255 2256 case IPPROTO_NONE: /* RFC 2460 */ 2257 PULLUP_TO(hlen, ulp, struct ip6_ext); 2258 /* Packet ends here. if ip6e_len!=0 octets 2259 * must be ignored. */ 2260 break; 2261 2262 case IPPROTO_OSPFIGP: 2263 /* XXX OSPF header check? */ 2264 PULLUP_TO(hlen, ulp, struct ip6_ext); 2265 break; 2266 2267 case IPPROTO_PIM: 2268 /* XXX PIM header check? */ 2269 PULLUP_TO(hlen, ulp, struct pim); 2270 break; 2271 2272 case IPPROTO_IPV6: /* RFC 2893 */ 2273 PULLUP_TO(hlen, ulp, struct ip6_hdr); 2274 break; 2275 2276 case IPPROTO_IPV4: /* RFC 2893 */ 2277 PULLUP_TO(hlen, ulp, struct ip); 2278 break; 2279 2280 default: 2281 printf("IPFW2: IPV6 - Unknown Extension " 2282 "Header(%d), ext_hd=%x\n", proto, ext_hd); 2283 if (fw_deny_unknown_exthdrs) 2284 return (IP_FW_DENY); 2285 PULLUP_TO(hlen, ulp, struct ip6_ext); 2286 break; 2287 } /*switch */ 2288 } 2289 args->f_id.src_ip6 = mtod(m,struct ip6_hdr *)->ip6_src; 2290 args->f_id.dst_ip6 = mtod(m,struct ip6_hdr *)->ip6_dst; 2291 args->f_id.src_ip = 0; 2292 args->f_id.dst_ip = 0; 2293 args->f_id.flow_id6 = ntohl(mtod(m, struct ip6_hdr *)->ip6_flow); 2294 } else if (pktlen >= sizeof(struct ip) && 2295 (args->eh == NULL || ntohs(args->eh->ether_type) == ETHERTYPE_IP) && 2296 mtod(m, struct ip *)->ip_v == 4) { 2297 is_ipv4 = 1; 2298 ip = mtod(m, struct ip *); 2299 hlen = ip->ip_hl << 2; 2300 args->f_id.addr_type = 4; 2301 2302 /* 2303 * Collect parameters into local variables for faster matching. 2304 */ 2305 proto = ip->ip_p; 2306 src_ip = ip->ip_src; 2307 dst_ip = ip->ip_dst; 2308 if (args->eh != NULL) { /* layer 2 packets are as on the wire */ 2309 offset = ntohs(ip->ip_off) & IP_OFFMASK; 2310 ip_len = ntohs(ip->ip_len); 2311 } else { 2312 offset = ip->ip_off & IP_OFFMASK; 2313 ip_len = ip->ip_len; 2314 } 2315 pktlen = ip_len < pktlen ? ip_len : pktlen; 2316 2317 if (offset == 0) { 2318 switch (proto) { 2319 case IPPROTO_TCP: 2320 PULLUP_TO(hlen, ulp, struct tcphdr); 2321 dst_port = TCP(ulp)->th_dport; 2322 src_port = TCP(ulp)->th_sport; 2323 args->f_id.flags = TCP(ulp)->th_flags; 2324 break; 2325 2326 case IPPROTO_UDP: 2327 PULLUP_TO(hlen, ulp, struct udphdr); 2328 dst_port = UDP(ulp)->uh_dport; 2329 src_port = UDP(ulp)->uh_sport; 2330 break; 2331 2332 case IPPROTO_ICMP: 2333 PULLUP_TO(hlen, ulp, struct icmphdr); 2334 args->f_id.flags = ICMP(ulp)->icmp_type; 2335 break; 2336 2337 default: 2338 break; 2339 } 2340 } 2341 2342 args->f_id.src_ip = ntohl(src_ip.s_addr); 2343 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 2344 } 2345#undef PULLUP_TO 2346 if (proto) { /* we may have port numbers, store them */ 2347 args->f_id.proto = proto; 2348 args->f_id.src_port = src_port = ntohs(src_port); 2349 args->f_id.dst_port = dst_port = ntohs(dst_port); 2350 } 2351 2352 IPFW_RLOCK(chain); 2353 mtag = m_tag_find(m, PACKET_TAG_DIVERT, NULL); 2354 if (args->rule) { 2355 /* 2356 * Packet has already been tagged. Look for the next rule 2357 * to restart processing. 2358 * 2359 * If fw_one_pass != 0 then just accept it. 2360 * XXX should not happen here, but optimized out in 2361 * the caller. 2362 */ 2363 if (fw_one_pass) { 2364 IPFW_RUNLOCK(chain); 2365 return (IP_FW_PASS); 2366 } 2367 2368 f = args->rule->next_rule; 2369 if (f == NULL) 2370 f = lookup_next_rule(args->rule); 2371 } else { 2372 /* 2373 * Find the starting rule. It can be either the first 2374 * one, or the one after divert_rule if asked so. 2375 */ 2376 int skipto = mtag ? divert_cookie(mtag) : 0; 2377 2378 f = chain->rules; 2379 if (args->eh == NULL && skipto != 0) { 2380 if (skipto >= IPFW_DEFAULT_RULE) { 2381 IPFW_RUNLOCK(chain); 2382 return (IP_FW_DENY); /* invalid */ 2383 } 2384 while (f && f->rulenum <= skipto) 2385 f = f->next; 2386 if (f == NULL) { /* drop packet */ 2387 IPFW_RUNLOCK(chain); 2388 return (IP_FW_DENY); 2389 } 2390 } 2391 } 2392 /* reset divert rule to avoid confusion later */ 2393 if (mtag) { 2394 divinput_flags = divert_info(mtag) & 2395 (IP_FW_DIVERT_OUTPUT_FLAG | IP_FW_DIVERT_LOOPBACK_FLAG); 2396 m_tag_delete(m, mtag); 2397 } 2398 2399 /* 2400 * Now scan the rules, and parse microinstructions for each rule. 2401 */ 2402 for (; f; f = f->next) { 2403 ipfw_insn *cmd; 2404 uint32_t tablearg = 0; 2405 int l, cmdlen, skip_or; /* skip rest of OR block */ 2406 2407again: 2408 if (set_disable & (1 << f->set) ) 2409 continue; 2410 2411 skip_or = 0; 2412 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 2413 l -= cmdlen, cmd += cmdlen) { 2414 int match; 2415 2416 /* 2417 * check_body is a jump target used when we find a 2418 * CHECK_STATE, and need to jump to the body of 2419 * the target rule. 2420 */ 2421 2422check_body: 2423 cmdlen = F_LEN(cmd); 2424 /* 2425 * An OR block (insn_1 || .. || insn_n) has the 2426 * F_OR bit set in all but the last instruction. 2427 * The first match will set "skip_or", and cause 2428 * the following instructions to be skipped until 2429 * past the one with the F_OR bit clear. 2430 */ 2431 if (skip_or) { /* skip this instruction */ 2432 if ((cmd->len & F_OR) == 0) 2433 skip_or = 0; /* next one is good */ 2434 continue; 2435 } 2436 match = 0; /* set to 1 if we succeed */ 2437 2438 switch (cmd->opcode) { 2439 /* 2440 * The first set of opcodes compares the packet's 2441 * fields with some pattern, setting 'match' if a 2442 * match is found. At the end of the loop there is 2443 * logic to deal with F_NOT and F_OR flags associated 2444 * with the opcode. 2445 */ 2446 case O_NOP: 2447 match = 1; 2448 break; 2449 2450 case O_FORWARD_MAC: 2451 printf("ipfw: opcode %d unimplemented\n", 2452 cmd->opcode); 2453 break; 2454 2455 case O_GID: 2456 case O_UID: 2457 case O_JAIL: 2458 /* 2459 * We only check offset == 0 && proto != 0, 2460 * as this ensures that we have a 2461 * packet with the ports info. 2462 */ 2463 if (offset!=0) 2464 break; 2465 if (is_ipv6) /* XXX to be fixed later */ 2466 break; 2467 if (proto == IPPROTO_TCP || 2468 proto == IPPROTO_UDP) 2469 match = check_uidgid( 2470 (ipfw_insn_u32 *)cmd, 2471 proto, oif, 2472 dst_ip, dst_port, 2473 src_ip, src_port, &fw_ugid_cache, 2474 &ugid_lookup, args->inp); 2475 break; 2476 2477 case O_RECV: 2478 match = iface_match(m->m_pkthdr.rcvif, 2479 (ipfw_insn_if *)cmd); 2480 break; 2481 2482 case O_XMIT: 2483 match = iface_match(oif, (ipfw_insn_if *)cmd); 2484 break; 2485 2486 case O_VIA: 2487 match = iface_match(oif ? oif : 2488 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd); 2489 break; 2490 2491 case O_MACADDR2: 2492 if (args->eh != NULL) { /* have MAC header */ 2493 u_int32_t *want = (u_int32_t *) 2494 ((ipfw_insn_mac *)cmd)->addr; 2495 u_int32_t *mask = (u_int32_t *) 2496 ((ipfw_insn_mac *)cmd)->mask; 2497 u_int32_t *hdr = (u_int32_t *)args->eh; 2498 2499 match = 2500 ( want[0] == (hdr[0] & mask[0]) && 2501 want[1] == (hdr[1] & mask[1]) && 2502 want[2] == (hdr[2] & mask[2]) ); 2503 } 2504 break; 2505 2506 case O_MAC_TYPE: 2507 if (args->eh != NULL) { 2508 u_int16_t t = 2509 ntohs(args->eh->ether_type); 2510 u_int16_t *p = 2511 ((ipfw_insn_u16 *)cmd)->ports; 2512 int i; 2513 2514 for (i = cmdlen - 1; !match && i>0; 2515 i--, p += 2) 2516 match = (t>=p[0] && t<=p[1]); 2517 } 2518 break; 2519 2520 case O_FRAG: 2521 match = (offset != 0); 2522 break; 2523 2524 case O_IN: /* "out" is "not in" */ 2525 match = (oif == NULL); 2526 break; 2527 2528 case O_LAYER2: 2529 match = (args->eh != NULL); 2530 break; 2531 2532 case O_DIVERTED: 2533 match = (cmd->arg1 & 1 && divinput_flags & 2534 IP_FW_DIVERT_LOOPBACK_FLAG) || 2535 (cmd->arg1 & 2 && divinput_flags & 2536 IP_FW_DIVERT_OUTPUT_FLAG); 2537 break; 2538 2539 case O_PROTO: 2540 /* 2541 * We do not allow an arg of 0 so the 2542 * check of "proto" only suffices. 2543 */ 2544 match = (proto == cmd->arg1); 2545 break; 2546 2547 case O_IP_SRC: 2548 match = is_ipv4 && 2549 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2550 src_ip.s_addr); 2551 break; 2552 2553 case O_IP_SRC_LOOKUP: 2554 case O_IP_DST_LOOKUP: 2555 if (is_ipv4) { 2556 uint32_t a = 2557 (cmd->opcode == O_IP_DST_LOOKUP) ? 2558 dst_ip.s_addr : src_ip.s_addr; 2559 uint32_t v; 2560 2561 match = lookup_table(chain, cmd->arg1, a, 2562 &v); 2563 if (!match) 2564 break; 2565 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 2566 match = 2567 ((ipfw_insn_u32 *)cmd)->d[0] == v; 2568 else 2569 tablearg = v; 2570 } 2571 break; 2572 2573 case O_IP_SRC_MASK: 2574 case O_IP_DST_MASK: 2575 if (is_ipv4) { 2576 uint32_t a = 2577 (cmd->opcode == O_IP_DST_MASK) ? 2578 dst_ip.s_addr : src_ip.s_addr; 2579 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 2580 int i = cmdlen-1; 2581 2582 for (; !match && i>0; i-= 2, p+= 2) 2583 match = (p[0] == (a & p[1])); 2584 } 2585 break; 2586 2587 case O_IP_SRC_ME: 2588 if (is_ipv4) { 2589 struct ifnet *tif; 2590 2591 INADDR_TO_IFP(src_ip, tif); 2592 match = (tif != NULL); 2593 } 2594 break; 2595 2596 case O_IP_DST_SET: 2597 case O_IP_SRC_SET: 2598 if (is_ipv4) { 2599 u_int32_t *d = (u_int32_t *)(cmd+1); 2600 u_int32_t addr = 2601 cmd->opcode == O_IP_DST_SET ? 2602 args->f_id.dst_ip : 2603 args->f_id.src_ip; 2604 2605 if (addr < d[0]) 2606 break; 2607 addr -= d[0]; /* subtract base */ 2608 match = (addr < cmd->arg1) && 2609 ( d[ 1 + (addr>>5)] & 2610 (1<<(addr & 0x1f)) ); 2611 } 2612 break; 2613 2614 case O_IP_DST: 2615 match = is_ipv4 && 2616 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2617 dst_ip.s_addr); 2618 break; 2619 2620 case O_IP_DST_ME: 2621 if (is_ipv4) { 2622 struct ifnet *tif; 2623 2624 INADDR_TO_IFP(dst_ip, tif); 2625 match = (tif != NULL); 2626 } 2627 break; 2628 2629 case O_IP_SRCPORT: 2630 case O_IP_DSTPORT: 2631 /* 2632 * offset == 0 && proto != 0 is enough 2633 * to guarantee that we have a 2634 * packet with port info. 2635 */ 2636 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP) 2637 && offset == 0) { 2638 u_int16_t x = 2639 (cmd->opcode == O_IP_SRCPORT) ? 2640 src_port : dst_port ; 2641 u_int16_t *p = 2642 ((ipfw_insn_u16 *)cmd)->ports; 2643 int i; 2644 2645 for (i = cmdlen - 1; !match && i>0; 2646 i--, p += 2) 2647 match = (x>=p[0] && x<=p[1]); 2648 } 2649 break; 2650 2651 case O_ICMPTYPE: 2652 match = (offset == 0 && proto==IPPROTO_ICMP && 2653 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 2654 break; 2655 2656#ifdef INET6 2657 case O_ICMP6TYPE: 2658 match = is_ipv6 && offset == 0 && 2659 proto==IPPROTO_ICMPV6 && 2660 icmp6type_match( 2661 ICMP6(ulp)->icmp6_type, 2662 (ipfw_insn_u32 *)cmd); 2663 break; 2664#endif /* INET6 */ 2665 2666 case O_IPOPT: 2667 match = (is_ipv4 && 2668 ipopts_match(mtod(m, struct ip *), cmd) ); 2669 break; 2670 2671 case O_IPVER: 2672 match = (is_ipv4 && 2673 cmd->arg1 == mtod(m, struct ip *)->ip_v); 2674 break; 2675 2676 case O_IPID: 2677 case O_IPLEN: 2678 case O_IPTTL: 2679 if (is_ipv4) { /* only for IP packets */ 2680 uint16_t x; 2681 uint16_t *p; 2682 int i; 2683 2684 if (cmd->opcode == O_IPLEN) 2685 x = ip_len; 2686 else if (cmd->opcode == O_IPTTL) 2687 x = mtod(m, struct ip *)->ip_ttl; 2688 else /* must be IPID */ 2689 x = ntohs(mtod(m, struct ip *)->ip_id); 2690 if (cmdlen == 1) { 2691 match = (cmd->arg1 == x); 2692 break; 2693 } 2694 /* otherwise we have ranges */ 2695 p = ((ipfw_insn_u16 *)cmd)->ports; 2696 i = cmdlen - 1; 2697 for (; !match && i>0; i--, p += 2) 2698 match = (x >= p[0] && x <= p[1]); 2699 } 2700 break; 2701 2702 case O_IPPRECEDENCE: 2703 match = (is_ipv4 && 2704 (cmd->arg1 == (mtod(m, struct ip *)->ip_tos & 0xe0)) ); 2705 break; 2706 2707 case O_IPTOS: 2708 match = (is_ipv4 && 2709 flags_match(cmd, mtod(m, struct ip *)->ip_tos)); 2710 break; 2711 2712 case O_TCPDATALEN: 2713 if (proto == IPPROTO_TCP && offset == 0) { 2714 struct tcphdr *tcp; 2715 uint16_t x; 2716 uint16_t *p; 2717 int i; 2718 2719 tcp = TCP(ulp); 2720 x = ip_len - 2721 ((ip->ip_hl + tcp->th_off) << 2); 2722 if (cmdlen == 1) { 2723 match = (cmd->arg1 == x); 2724 break; 2725 } 2726 /* otherwise we have ranges */ 2727 p = ((ipfw_insn_u16 *)cmd)->ports; 2728 i = cmdlen - 1; 2729 for (; !match && i>0; i--, p += 2) 2730 match = (x >= p[0] && x <= p[1]); 2731 } 2732 break; 2733 2734 case O_TCPFLAGS: 2735 match = (proto == IPPROTO_TCP && offset == 0 && 2736 flags_match(cmd, TCP(ulp)->th_flags)); 2737 break; 2738 2739 case O_TCPOPTS: 2740 match = (proto == IPPROTO_TCP && offset == 0 && 2741 tcpopts_match(TCP(ulp), cmd)); 2742 break; 2743 2744 case O_TCPSEQ: 2745 match = (proto == IPPROTO_TCP && offset == 0 && 2746 ((ipfw_insn_u32 *)cmd)->d[0] == 2747 TCP(ulp)->th_seq); 2748 break; 2749 2750 case O_TCPACK: 2751 match = (proto == IPPROTO_TCP && offset == 0 && 2752 ((ipfw_insn_u32 *)cmd)->d[0] == 2753 TCP(ulp)->th_ack); 2754 break; 2755 2756 case O_TCPWIN: 2757 match = (proto == IPPROTO_TCP && offset == 0 && 2758 cmd->arg1 == TCP(ulp)->th_win); 2759 break; 2760 2761 case O_ESTAB: 2762 /* reject packets which have SYN only */ 2763 /* XXX should i also check for TH_ACK ? */ 2764 match = (proto == IPPROTO_TCP && offset == 0 && 2765 (TCP(ulp)->th_flags & 2766 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 2767 break; 2768 2769 case O_ALTQ: { 2770 struct altq_tag *at; 2771 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 2772 2773 match = 1; 2774 mtag = m_tag_find(m, PACKET_TAG_PF_QID, NULL); 2775 if (mtag != NULL) 2776 break; 2777 mtag = m_tag_get(PACKET_TAG_PF_QID, 2778 sizeof(struct altq_tag), 2779 M_NOWAIT); 2780 if (mtag == NULL) { 2781 /* 2782 * Let the packet fall back to the 2783 * default ALTQ. 2784 */ 2785 break; 2786 } 2787 at = (struct altq_tag *)(mtag+1); 2788 at->qid = altq->qid; 2789 if (is_ipv4) 2790 at->af = AF_INET; 2791 else 2792 at->af = AF_LINK; 2793 at->hdr = ip; 2794 m_tag_prepend(m, mtag); 2795 break; 2796 } 2797 2798 case O_LOG: 2799 if (fw_verbose) 2800 ipfw_log(f, hlen, args, m, 2801 oif, offset, tablearg); 2802 match = 1; 2803 break; 2804 2805 case O_PROB: 2806 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 2807 break; 2808 2809 case O_VERREVPATH: 2810 /* Outgoing packets automatically pass/match */ 2811 match = ((oif != NULL) || 2812 (m->m_pkthdr.rcvif == NULL) || 2813 ( 2814#ifdef INET6 2815 is_ipv6 ? 2816 verify_path6(&(args->f_id.src_ip6), 2817 m->m_pkthdr.rcvif) : 2818#endif 2819 verify_path(src_ip, m->m_pkthdr.rcvif))); 2820 break; 2821 2822 case O_VERSRCREACH: 2823 /* Outgoing packets automatically pass/match */ 2824 match = (hlen > 0 && ((oif != NULL) || 2825#ifdef INET6 2826 is_ipv6 ? 2827 verify_path6(&(args->f_id.src_ip6), 2828 NULL) : 2829#endif 2830 verify_path(src_ip, NULL))); 2831 break; 2832 2833 case O_ANTISPOOF: 2834 /* Outgoing packets automatically pass/match */ 2835 if (oif == NULL && hlen > 0 && 2836 ( (is_ipv4 && in_localaddr(src_ip)) 2837#ifdef INET6 2838 || (is_ipv6 && 2839 in6_localaddr(&(args->f_id.src_ip6))) 2840#endif 2841 )) 2842 match = 2843#ifdef INET6 2844 is_ipv6 ? verify_path6( 2845 &(args->f_id.src_ip6), 2846 m->m_pkthdr.rcvif) : 2847#endif 2848 verify_path(src_ip, 2849 m->m_pkthdr.rcvif); 2850 else 2851 match = 1; 2852 break; 2853 2854 case O_IPSEC: 2855#ifdef FAST_IPSEC 2856 match = (m_tag_find(m, 2857 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 2858#endif 2859#ifdef IPSEC 2860 match = (ipsec_getnhist(m) != 0); 2861#endif 2862 /* otherwise no match */ 2863 break; 2864 2865#ifdef INET6 2866 case O_IP6_SRC: 2867 match = is_ipv6 && 2868 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 2869 &((ipfw_insn_ip6 *)cmd)->addr6); 2870 break; 2871 2872 case O_IP6_DST: 2873 match = is_ipv6 && 2874 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 2875 &((ipfw_insn_ip6 *)cmd)->addr6); 2876 break; 2877 case O_IP6_SRC_MASK: 2878 if (is_ipv6) { 2879 ipfw_insn_ip6 *te = (ipfw_insn_ip6 *)cmd; 2880 struct in6_addr p = args->f_id.src_ip6; 2881 2882 APPLY_MASK(&p, &te->mask6); 2883 match = IN6_ARE_ADDR_EQUAL(&te->addr6, &p); 2884 } 2885 break; 2886 2887 case O_IP6_DST_MASK: 2888 if (is_ipv6) { 2889 ipfw_insn_ip6 *te = (ipfw_insn_ip6 *)cmd; 2890 struct in6_addr p = args->f_id.dst_ip6; 2891 2892 APPLY_MASK(&p, &te->mask6); 2893 match = IN6_ARE_ADDR_EQUAL(&te->addr6, &p); 2894 } 2895 break; 2896 2897 case O_IP6_SRC_ME: 2898 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6); 2899 break; 2900 2901 case O_IP6_DST_ME: 2902 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6); 2903 break; 2904 2905 case O_FLOW6ID: 2906 match = is_ipv6 && 2907 flow6id_match(args->f_id.flow_id6, 2908 (ipfw_insn_u32 *) cmd); 2909 break; 2910 2911 case O_EXT_HDR: 2912 match = is_ipv6 && 2913 (ext_hd & ((ipfw_insn *) cmd)->arg1); 2914 break; 2915 2916 case O_IP6: 2917 match = is_ipv6; 2918 break; 2919#endif 2920 2921 case O_IP4: 2922 match = is_ipv4; 2923 break; 2924 2925 case O_TAG: { 2926 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ? 2927 tablearg : cmd->arg1; 2928 2929 /* Packet is already tagged with this tag? */ 2930 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 2931 2932 /* We have `untag' action when F_NOT flag is 2933 * present. And we must remove this mtag from 2934 * mbuf and reset `match' to zero (`match' will 2935 * be inversed later). 2936 * Otherwise we should allocate new mtag and 2937 * push it into mbuf. 2938 */ 2939 if (cmd->len & F_NOT) { /* `untag' action */ 2940 if (mtag != NULL) 2941 m_tag_delete(m, mtag); 2942 } else if (mtag == NULL) { 2943 if ((mtag = m_tag_alloc(MTAG_IPFW, 2944 tag, 0, M_NOWAIT)) != NULL) 2945 m_tag_prepend(m, mtag); 2946 } 2947 match = (cmd->len & F_NOT) ? 0: 1; 2948 break; 2949 } 2950 2951 case O_TAGGED: { 2952 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ? 2953 tablearg : cmd->arg1; 2954 2955 if (cmdlen == 1) { 2956 match = m_tag_locate(m, MTAG_IPFW, 2957 tag, NULL) != NULL; 2958 break; 2959 } 2960 2961 /* we have ranges */ 2962 for (mtag = m_tag_first(m); 2963 mtag != NULL && !match; 2964 mtag = m_tag_next(m, mtag)) { 2965 uint16_t *p; 2966 int i; 2967 2968 if (mtag->m_tag_cookie != MTAG_IPFW) 2969 continue; 2970 2971 p = ((ipfw_insn_u16 *)cmd)->ports; 2972 i = cmdlen - 1; 2973 for(; !match && i > 0; i--, p += 2) 2974 match = 2975 mtag->m_tag_id >= p[0] && 2976 mtag->m_tag_id <= p[1]; 2977 } 2978 break; 2979 } 2980 2981 /* 2982 * The second set of opcodes represents 'actions', 2983 * i.e. the terminal part of a rule once the packet 2984 * matches all previous patterns. 2985 * Typically there is only one action for each rule, 2986 * and the opcode is stored at the end of the rule 2987 * (but there are exceptions -- see below). 2988 * 2989 * In general, here we set retval and terminate the 2990 * outer loop (would be a 'break 3' in some language, 2991 * but we need to do a 'goto done'). 2992 * 2993 * Exceptions: 2994 * O_COUNT and O_SKIPTO actions: 2995 * instead of terminating, we jump to the next rule 2996 * ('goto next_rule', equivalent to a 'break 2'), 2997 * or to the SKIPTO target ('goto again' after 2998 * having set f, cmd and l), respectively. 2999 * 3000 * O_TAG, O_LOG and O_ALTQ action parameters: 3001 * perform some action and set match = 1; 3002 * 3003 * O_LIMIT and O_KEEP_STATE: these opcodes are 3004 * not real 'actions', and are stored right 3005 * before the 'action' part of the rule. 3006 * These opcodes try to install an entry in the 3007 * state tables; if successful, we continue with 3008 * the next opcode (match=1; break;), otherwise 3009 * the packet * must be dropped 3010 * ('goto done' after setting retval); 3011 * 3012 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 3013 * cause a lookup of the state table, and a jump 3014 * to the 'action' part of the parent rule 3015 * ('goto check_body') if an entry is found, or 3016 * (CHECK_STATE only) a jump to the next rule if 3017 * the entry is not found ('goto next_rule'). 3018 * The result of the lookup is cached to make 3019 * further instances of these opcodes are 3020 * effectively NOPs. 3021 */ 3022 case O_LIMIT: 3023 case O_KEEP_STATE: 3024 if (install_state(f, 3025 (ipfw_insn_limit *)cmd, args, tablearg)) { 3026 retval = IP_FW_DENY; 3027 goto done; /* error/limit violation */ 3028 } 3029 match = 1; 3030 break; 3031 3032 case O_PROBE_STATE: 3033 case O_CHECK_STATE: 3034 /* 3035 * dynamic rules are checked at the first 3036 * keep-state or check-state occurrence, 3037 * with the result being stored in dyn_dir. 3038 * The compiler introduces a PROBE_STATE 3039 * instruction for us when we have a 3040 * KEEP_STATE (because PROBE_STATE needs 3041 * to be run first). 3042 */ 3043 if (dyn_dir == MATCH_UNKNOWN && 3044 (q = lookup_dyn_rule(&args->f_id, 3045 &dyn_dir, proto == IPPROTO_TCP ? 3046 TCP(ulp) : NULL)) 3047 != NULL) { 3048 /* 3049 * Found dynamic entry, update stats 3050 * and jump to the 'action' part of 3051 * the parent rule. 3052 */ 3053 q->pcnt++; 3054 q->bcnt += pktlen; 3055 f = q->rule; 3056 cmd = ACTION_PTR(f); 3057 l = f->cmd_len - f->act_ofs; 3058 IPFW_DYN_UNLOCK(); 3059 goto check_body; 3060 } 3061 /* 3062 * Dynamic entry not found. If CHECK_STATE, 3063 * skip to next rule, if PROBE_STATE just 3064 * ignore and continue with next opcode. 3065 */ 3066 if (cmd->opcode == O_CHECK_STATE) 3067 goto next_rule; 3068 match = 1; 3069 break; 3070 3071 case O_ACCEPT: 3072 retval = 0; /* accept */ 3073 goto done; 3074 3075 case O_PIPE: 3076 case O_QUEUE: 3077 args->rule = f; /* report matching rule */ 3078 if (cmd->arg1 == IP_FW_TABLEARG) 3079 args->cookie = tablearg; 3080 else 3081 args->cookie = cmd->arg1; 3082 retval = IP_FW_DUMMYNET; 3083 goto done; 3084 3085 case O_DIVERT: 3086 case O_TEE: { 3087 struct divert_tag *dt; 3088 3089 if (args->eh) /* not on layer 2 */ 3090 break; 3091 mtag = m_tag_get(PACKET_TAG_DIVERT, 3092 sizeof(struct divert_tag), 3093 M_NOWAIT); 3094 if (mtag == NULL) { 3095 /* XXX statistic */ 3096 /* drop packet */ 3097 IPFW_RUNLOCK(chain); 3098 return (IP_FW_DENY); 3099 } 3100 dt = (struct divert_tag *)(mtag+1); 3101 dt->cookie = f->rulenum; 3102 if (cmd->arg1 == IP_FW_TABLEARG) 3103 dt->info = tablearg; 3104 else 3105 dt->info = cmd->arg1; 3106 m_tag_prepend(m, mtag); 3107 retval = (cmd->opcode == O_DIVERT) ? 3108 IP_FW_DIVERT : IP_FW_TEE; 3109 goto done; 3110 } 3111 3112 case O_COUNT: 3113 case O_SKIPTO: 3114 f->pcnt++; /* update stats */ 3115 f->bcnt += pktlen; 3116 f->timestamp = time_uptime; 3117 if (cmd->opcode == O_COUNT) 3118 goto next_rule; 3119 /* handle skipto */ 3120 if (f->next_rule == NULL) 3121 lookup_next_rule(f); 3122 f = f->next_rule; 3123 goto again; 3124 3125 case O_REJECT: 3126 /* 3127 * Drop the packet and send a reject notice 3128 * if the packet is not ICMP (or is an ICMP 3129 * query), and it is not multicast/broadcast. 3130 */ 3131 if (hlen > 0 && is_ipv4 && offset == 0 && 3132 (proto != IPPROTO_ICMP || 3133 is_icmp_query(ICMP(ulp))) && 3134 !(m->m_flags & (M_BCAST|M_MCAST)) && 3135 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 3136 send_reject(args, cmd->arg1, ip_len); 3137 m = args->m; 3138 } 3139 /* FALLTHROUGH */ 3140#ifdef INET6 3141 case O_UNREACH6: 3142 if (hlen > 0 && is_ipv6 && 3143 ((offset & IP6F_OFF_MASK) == 0) && 3144 (proto != IPPROTO_ICMPV6 || 3145 (is_icmp6_query(args->f_id.flags) == 1)) && 3146 !(m->m_flags & (M_BCAST|M_MCAST)) && 3147 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 3148 send_reject6(args, cmd->arg1, hlen); 3149 m = args->m; 3150 } 3151 /* FALLTHROUGH */ 3152#endif 3153 case O_DENY: 3154 retval = IP_FW_DENY; 3155 goto done; 3156 3157 case O_FORWARD_IP: { 3158 struct sockaddr_in *sa; 3159 sa = &(((ipfw_insn_sa *)cmd)->sa); 3160 if (args->eh) /* not valid on layer2 pkts */ 3161 break; 3162 if (!q || dyn_dir == MATCH_FORWARD) { 3163 if (sa->sin_addr.s_addr == INADDR_ANY) { 3164 bcopy(sa, &args->hopstore, 3165 sizeof(*sa)); 3166 args->hopstore.sin_addr.s_addr = 3167 htonl(tablearg); 3168 args->next_hop = 3169 &args->hopstore; 3170 } else { 3171 args->next_hop = sa; 3172 } 3173 } 3174 retval = IP_FW_PASS; 3175 } 3176 goto done; 3177 3178 case O_NETGRAPH: 3179 case O_NGTEE: 3180 args->rule = f; /* report matching rule */ 3181 if (cmd->arg1 == IP_FW_TABLEARG) 3182 args->cookie = tablearg; 3183 else 3184 args->cookie = cmd->arg1; 3185 retval = (cmd->opcode == O_NETGRAPH) ? 3186 IP_FW_NETGRAPH : IP_FW_NGTEE; 3187 goto done; 3188 3189 default: 3190 panic("-- unknown opcode %d\n", cmd->opcode); 3191 } /* end of switch() on opcodes */ 3192 3193 if (cmd->len & F_NOT) 3194 match = !match; 3195 3196 if (match) { 3197 if (cmd->len & F_OR) 3198 skip_or = 1; 3199 } else { 3200 if (!(cmd->len & F_OR)) /* not an OR block, */ 3201 break; /* try next rule */ 3202 } 3203 3204 } /* end of inner for, scan opcodes */ 3205 3206next_rule:; /* try next rule */ 3207 3208 } /* end of outer for, scan rules */ 3209 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 3210 IPFW_RUNLOCK(chain); 3211 return (IP_FW_DENY); 3212 3213done: 3214 /* Update statistics */ 3215 f->pcnt++; 3216 f->bcnt += pktlen; 3217 f->timestamp = time_uptime; 3218 IPFW_RUNLOCK(chain); 3219 return (retval); 3220 3221pullup_failed: 3222 if (fw_verbose) 3223 printf("ipfw: pullup failed\n"); 3224 return (IP_FW_DENY); 3225} 3226 3227/* 3228 * When a rule is added/deleted, clear the next_rule pointers in all rules. 3229 * These will be reconstructed on the fly as packets are matched. 3230 */ 3231static void 3232flush_rule_ptrs(struct ip_fw_chain *chain) 3233{ 3234 struct ip_fw *rule; 3235 3236 IPFW_WLOCK_ASSERT(chain); 3237 3238 for (rule = chain->rules; rule; rule = rule->next) 3239 rule->next_rule = NULL; 3240} 3241 3242/* 3243 * Add a new rule to the list. Copy the rule into a malloc'ed area, then 3244 * possibly create a rule number and add the rule to the list. 3245 * Update the rule_number in the input struct so the caller knows it as well. 3246 */ 3247static int 3248add_rule(struct ip_fw_chain *chain, struct ip_fw *input_rule) 3249{ 3250 struct ip_fw *rule, *f, *prev; 3251 int l = RULESIZE(input_rule); 3252 3253 if (chain->rules == NULL && input_rule->rulenum != IPFW_DEFAULT_RULE) 3254 return (EINVAL); 3255 3256 rule = malloc(l, M_IPFW, M_NOWAIT | M_ZERO); 3257 if (rule == NULL) 3258 return (ENOSPC); 3259 3260 bcopy(input_rule, rule, l); 3261 3262 rule->next = NULL; 3263 rule->next_rule = NULL; 3264 3265 rule->pcnt = 0; 3266 rule->bcnt = 0; 3267 rule->timestamp = 0; 3268 3269 IPFW_WLOCK(chain); 3270 3271 if (chain->rules == NULL) { /* default rule */ 3272 chain->rules = rule; 3273 goto done; 3274 } 3275 3276 /* 3277 * If rulenum is 0, find highest numbered rule before the 3278 * default rule, and add autoinc_step 3279 */ 3280 if (autoinc_step < 1) 3281 autoinc_step = 1; 3282 else if (autoinc_step > 1000) 3283 autoinc_step = 1000; 3284 if (rule->rulenum == 0) { 3285 /* 3286 * locate the highest numbered rule before default 3287 */ 3288 for (f = chain->rules; f; f = f->next) { 3289 if (f->rulenum == IPFW_DEFAULT_RULE) 3290 break; 3291 rule->rulenum = f->rulenum; 3292 } 3293 if (rule->rulenum < IPFW_DEFAULT_RULE - autoinc_step) 3294 rule->rulenum += autoinc_step; 3295 input_rule->rulenum = rule->rulenum; 3296 } 3297 3298 /* 3299 * Now insert the new rule in the right place in the sorted list. 3300 */ 3301 for (prev = NULL, f = chain->rules; f; prev = f, f = f->next) { 3302 if (f->rulenum > rule->rulenum) { /* found the location */ 3303 if (prev) { 3304 rule->next = f; 3305 prev->next = rule; 3306 } else { /* head insert */ 3307 rule->next = chain->rules; 3308 chain->rules = rule; 3309 } 3310 break; 3311 } 3312 } 3313 flush_rule_ptrs(chain); 3314done: 3315 static_count++; 3316 static_len += l; 3317 IPFW_WUNLOCK(chain); 3318 DEB(printf("ipfw: installed rule %d, static count now %d\n", 3319 rule->rulenum, static_count);) 3320 return (0); 3321} 3322 3323/** 3324 * Remove a static rule (including derived * dynamic rules) 3325 * and place it on the ``reap list'' for later reclamation. 3326 * The caller is in charge of clearing rule pointers to avoid 3327 * dangling pointers. 3328 * @return a pointer to the next entry. 3329 * Arguments are not checked, so they better be correct. 3330 */ 3331static struct ip_fw * 3332remove_rule(struct ip_fw_chain *chain, struct ip_fw *rule, struct ip_fw *prev) 3333{ 3334 struct ip_fw *n; 3335 int l = RULESIZE(rule); 3336 3337 IPFW_WLOCK_ASSERT(chain); 3338 3339 n = rule->next; 3340 IPFW_DYN_LOCK(); 3341 remove_dyn_rule(rule, NULL /* force removal */); 3342 IPFW_DYN_UNLOCK(); 3343 if (prev == NULL) 3344 chain->rules = n; 3345 else 3346 prev->next = n; 3347 static_count--; 3348 static_len -= l; 3349 3350 rule->next = chain->reap; 3351 chain->reap = rule; 3352 3353 return n; 3354} 3355 3356/** 3357 * Reclaim storage associated with a list of rules. This is 3358 * typically the list created using remove_rule. 3359 */ 3360static void 3361reap_rules(struct ip_fw *head) 3362{ 3363 struct ip_fw *rule; 3364 3365 while ((rule = head) != NULL) { 3366 head = head->next; 3367 if (DUMMYNET_LOADED) 3368 ip_dn_ruledel_ptr(rule); 3369 free(rule, M_IPFW); 3370 } 3371} 3372 3373/* 3374 * Remove all rules from a chain (except rules in set RESVD_SET 3375 * unless kill_default = 1). The caller is responsible for 3376 * reclaiming storage for the rules left in chain->reap. 3377 */ 3378static void 3379free_chain(struct ip_fw_chain *chain, int kill_default) 3380{ 3381 struct ip_fw *prev, *rule; 3382 3383 IPFW_WLOCK_ASSERT(chain); 3384 3385 flush_rule_ptrs(chain); /* more efficient to do outside the loop */ 3386 for (prev = NULL, rule = chain->rules; rule ; ) 3387 if (kill_default || rule->set != RESVD_SET) 3388 rule = remove_rule(chain, rule, prev); 3389 else { 3390 prev = rule; 3391 rule = rule->next; 3392 } 3393} 3394 3395/** 3396 * Remove all rules with given number, and also do set manipulation. 3397 * Assumes chain != NULL && *chain != NULL. 3398 * 3399 * The argument is an u_int32_t. The low 16 bit are the rule or set number, 3400 * the next 8 bits are the new set, the top 8 bits are the command: 3401 * 3402 * 0 delete rules with given number 3403 * 1 delete rules with given set number 3404 * 2 move rules with given number to new set 3405 * 3 move rules with given set number to new set 3406 * 4 swap sets with given numbers 3407 */ 3408static int 3409del_entry(struct ip_fw_chain *chain, u_int32_t arg) 3410{ 3411 struct ip_fw *prev = NULL, *rule; 3412 u_int16_t rulenum; /* rule or old_set */ 3413 u_int8_t cmd, new_set; 3414 3415 rulenum = arg & 0xffff; 3416 cmd = (arg >> 24) & 0xff; 3417 new_set = (arg >> 16) & 0xff; 3418 3419 if (cmd > 4) 3420 return EINVAL; 3421 if (new_set > RESVD_SET) 3422 return EINVAL; 3423 if (cmd == 0 || cmd == 2) { 3424 if (rulenum >= IPFW_DEFAULT_RULE) 3425 return EINVAL; 3426 } else { 3427 if (rulenum > RESVD_SET) /* old_set */ 3428 return EINVAL; 3429 } 3430 3431 IPFW_WLOCK(chain); 3432 rule = chain->rules; 3433 chain->reap = NULL; 3434 switch (cmd) { 3435 case 0: /* delete rules with given number */ 3436 /* 3437 * locate first rule to delete 3438 */ 3439 for (; rule->rulenum < rulenum; prev = rule, rule = rule->next) 3440 ; 3441 if (rule->rulenum != rulenum) { 3442 IPFW_WUNLOCK(chain); 3443 return EINVAL; 3444 } 3445 3446 /* 3447 * flush pointers outside the loop, then delete all matching 3448 * rules. prev remains the same throughout the cycle. 3449 */ 3450 flush_rule_ptrs(chain); 3451 while (rule->rulenum == rulenum) 3452 rule = remove_rule(chain, rule, prev); 3453 break; 3454 3455 case 1: /* delete all rules with given set number */ 3456 flush_rule_ptrs(chain); 3457 rule = chain->rules; 3458 while (rule->rulenum < IPFW_DEFAULT_RULE) 3459 if (rule->set == rulenum) 3460 rule = remove_rule(chain, rule, prev); 3461 else { 3462 prev = rule; 3463 rule = rule->next; 3464 } 3465 break; 3466 3467 case 2: /* move rules with given number to new set */ 3468 rule = chain->rules; 3469 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3470 if (rule->rulenum == rulenum) 3471 rule->set = new_set; 3472 break; 3473 3474 case 3: /* move rules with given set number to new set */ 3475 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3476 if (rule->set == rulenum) 3477 rule->set = new_set; 3478 break; 3479 3480 case 4: /* swap two sets */ 3481 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3482 if (rule->set == rulenum) 3483 rule->set = new_set; 3484 else if (rule->set == new_set) 3485 rule->set = rulenum; 3486 break; 3487 } 3488 /* 3489 * Look for rules to reclaim. We grab the list before 3490 * releasing the lock then reclaim them w/o the lock to 3491 * avoid a LOR with dummynet. 3492 */ 3493 rule = chain->reap; 3494 chain->reap = NULL; 3495 IPFW_WUNLOCK(chain); 3496 if (rule) 3497 reap_rules(rule); 3498 return 0; 3499} 3500 3501/* 3502 * Clear counters for a specific rule. 3503 * The enclosing "table" is assumed locked. 3504 */ 3505static void 3506clear_counters(struct ip_fw *rule, int log_only) 3507{ 3508 ipfw_insn_log *l = (ipfw_insn_log *)ACTION_PTR(rule); 3509 3510 if (log_only == 0) { 3511 rule->bcnt = rule->pcnt = 0; 3512 rule->timestamp = 0; 3513 } 3514 if (l->o.opcode == O_LOG) 3515 l->log_left = l->max_log; 3516} 3517 3518/** 3519 * Reset some or all counters on firewall rules. 3520 * @arg frwl is null to clear all entries, or contains a specific 3521 * rule number. 3522 * @arg log_only is 1 if we only want to reset logs, zero otherwise. 3523 */ 3524static int 3525zero_entry(struct ip_fw_chain *chain, int rulenum, int log_only) 3526{ 3527 struct ip_fw *rule; 3528 char *msg; 3529 3530 IPFW_WLOCK(chain); 3531 if (rulenum == 0) { 3532 norule_counter = 0; 3533 for (rule = chain->rules; rule; rule = rule->next) 3534 clear_counters(rule, log_only); 3535 msg = log_only ? "ipfw: All logging counts reset.\n" : 3536 "ipfw: Accounting cleared.\n"; 3537 } else { 3538 int cleared = 0; 3539 /* 3540 * We can have multiple rules with the same number, so we 3541 * need to clear them all. 3542 */ 3543 for (rule = chain->rules; rule; rule = rule->next) 3544 if (rule->rulenum == rulenum) { 3545 while (rule && rule->rulenum == rulenum) { 3546 clear_counters(rule, log_only); 3547 rule = rule->next; 3548 } 3549 cleared = 1; 3550 break; 3551 } 3552 if (!cleared) { /* we did not find any matching rules */ 3553 IPFW_WUNLOCK(chain); 3554 return (EINVAL); 3555 } 3556 msg = log_only ? "ipfw: Entry %d logging count reset.\n" : 3557 "ipfw: Entry %d cleared.\n"; 3558 } 3559 IPFW_WUNLOCK(chain); 3560 3561 if (fw_verbose) 3562 log(LOG_SECURITY | LOG_NOTICE, msg, rulenum); 3563 return (0); 3564} 3565 3566/* 3567 * Check validity of the structure before insert. 3568 * Fortunately rules are simple, so this mostly need to check rule sizes. 3569 */ 3570static int 3571check_ipfw_struct(struct ip_fw *rule, int size) 3572{ 3573 int l, cmdlen = 0; 3574 int have_action=0; 3575 ipfw_insn *cmd; 3576 3577 if (size < sizeof(*rule)) { 3578 printf("ipfw: rule too short\n"); 3579 return (EINVAL); 3580 } 3581 /* first, check for valid size */ 3582 l = RULESIZE(rule); 3583 if (l != size) { 3584 printf("ipfw: size mismatch (have %d want %d)\n", size, l); 3585 return (EINVAL); 3586 } 3587 if (rule->act_ofs >= rule->cmd_len) { 3588 printf("ipfw: bogus action offset (%u > %u)\n", 3589 rule->act_ofs, rule->cmd_len - 1); 3590 return (EINVAL); 3591 } 3592 /* 3593 * Now go for the individual checks. Very simple ones, basically only 3594 * instruction sizes. 3595 */ 3596 for (l = rule->cmd_len, cmd = rule->cmd ; 3597 l > 0 ; l -= cmdlen, cmd += cmdlen) { 3598 cmdlen = F_LEN(cmd); 3599 if (cmdlen > l) { 3600 printf("ipfw: opcode %d size truncated\n", 3601 cmd->opcode); 3602 return EINVAL; 3603 } 3604 DEB(printf("ipfw: opcode %d\n", cmd->opcode);) 3605 switch (cmd->opcode) { 3606 case O_PROBE_STATE: 3607 case O_KEEP_STATE: 3608 case O_PROTO: 3609 case O_IP_SRC_ME: 3610 case O_IP_DST_ME: 3611 case O_LAYER2: 3612 case O_IN: 3613 case O_FRAG: 3614 case O_DIVERTED: 3615 case O_IPOPT: 3616 case O_IPTOS: 3617 case O_IPPRECEDENCE: 3618 case O_IPVER: 3619 case O_TCPWIN: 3620 case O_TCPFLAGS: 3621 case O_TCPOPTS: 3622 case O_ESTAB: 3623 case O_VERREVPATH: 3624 case O_VERSRCREACH: 3625 case O_ANTISPOOF: 3626 case O_IPSEC: 3627#ifdef INET6 3628 case O_IP6_SRC_ME: 3629 case O_IP6_DST_ME: 3630 case O_EXT_HDR: 3631 case O_IP6: 3632#endif 3633 case O_IP4: 3634 case O_TAG: 3635 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 3636 goto bad_size; 3637 break; 3638 3639 case O_UID: 3640 case O_GID: 3641 case O_JAIL: 3642 case O_IP_SRC: 3643 case O_IP_DST: 3644 case O_TCPSEQ: 3645 case O_TCPACK: 3646 case O_PROB: 3647 case O_ICMPTYPE: 3648 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32)) 3649 goto bad_size; 3650 break; 3651 3652 case O_LIMIT: 3653 if (cmdlen != F_INSN_SIZE(ipfw_insn_limit)) 3654 goto bad_size; 3655 break; 3656 3657 case O_LOG: 3658 if (cmdlen != F_INSN_SIZE(ipfw_insn_log)) 3659 goto bad_size; 3660 3661 ((ipfw_insn_log *)cmd)->log_left = 3662 ((ipfw_insn_log *)cmd)->max_log; 3663 3664 break; 3665 3666 case O_IP_SRC_MASK: 3667 case O_IP_DST_MASK: 3668 /* only odd command lengths */ 3669 if ( !(cmdlen & 1) || cmdlen > 31) 3670 goto bad_size; 3671 break; 3672 3673 case O_IP_SRC_SET: 3674 case O_IP_DST_SET: 3675 if (cmd->arg1 == 0 || cmd->arg1 > 256) { 3676 printf("ipfw: invalid set size %d\n", 3677 cmd->arg1); 3678 return EINVAL; 3679 } 3680 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) + 3681 (cmd->arg1+31)/32 ) 3682 goto bad_size; 3683 break; 3684 3685 case O_IP_SRC_LOOKUP: 3686 case O_IP_DST_LOOKUP: 3687 if (cmd->arg1 >= IPFW_TABLES_MAX) { 3688 printf("ipfw: invalid table number %d\n", 3689 cmd->arg1); 3690 return (EINVAL); 3691 } 3692 if (cmdlen != F_INSN_SIZE(ipfw_insn) && 3693 cmdlen != F_INSN_SIZE(ipfw_insn_u32)) 3694 goto bad_size; 3695 break; 3696 3697 case O_MACADDR2: 3698 if (cmdlen != F_INSN_SIZE(ipfw_insn_mac)) 3699 goto bad_size; 3700 break; 3701 3702 case O_NOP: 3703 case O_IPID: 3704 case O_IPTTL: 3705 case O_IPLEN: 3706 case O_TCPDATALEN: 3707 case O_TAGGED: 3708 if (cmdlen < 1 || cmdlen > 31) 3709 goto bad_size; 3710 break; 3711 3712 case O_MAC_TYPE: 3713 case O_IP_SRCPORT: 3714 case O_IP_DSTPORT: /* XXX artificial limit, 30 port pairs */ 3715 if (cmdlen < 2 || cmdlen > 31) 3716 goto bad_size; 3717 break; 3718 3719 case O_RECV: 3720 case O_XMIT: 3721 case O_VIA: 3722 if (cmdlen != F_INSN_SIZE(ipfw_insn_if)) 3723 goto bad_size; 3724 break; 3725 3726 case O_ALTQ: 3727 if (cmdlen != F_INSN_SIZE(ipfw_insn_altq)) 3728 goto bad_size; 3729 break; 3730 3731 case O_PIPE: 3732 case O_QUEUE: 3733 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 3734 goto bad_size; 3735 goto check_action; 3736 3737 case O_FORWARD_IP: 3738#ifdef IPFIREWALL_FORWARD 3739 if (cmdlen != F_INSN_SIZE(ipfw_insn_sa)) 3740 goto bad_size; 3741 goto check_action; 3742#else 3743 return EINVAL; 3744#endif 3745 3746 case O_DIVERT: 3747 case O_TEE: 3748 if (ip_divert_ptr == NULL) 3749 return EINVAL; 3750 else 3751 goto check_size; 3752 case O_NETGRAPH: 3753 case O_NGTEE: 3754 if (!NG_IPFW_LOADED) 3755 return EINVAL; 3756 else 3757 goto check_size; 3758 case O_FORWARD_MAC: /* XXX not implemented yet */ 3759 case O_CHECK_STATE: 3760 case O_COUNT: 3761 case O_ACCEPT: 3762 case O_DENY: 3763 case O_REJECT: 3764#ifdef INET6 3765 case O_UNREACH6: 3766#endif 3767 case O_SKIPTO: 3768check_size: 3769 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 3770 goto bad_size; 3771check_action: 3772 if (have_action) { 3773 printf("ipfw: opcode %d, multiple actions" 3774 " not allowed\n", 3775 cmd->opcode); 3776 return EINVAL; 3777 } 3778 have_action = 1; 3779 if (l != cmdlen) { 3780 printf("ipfw: opcode %d, action must be" 3781 " last opcode\n", 3782 cmd->opcode); 3783 return EINVAL; 3784 } 3785 break; 3786#ifdef INET6 3787 case O_IP6_SRC: 3788 case O_IP6_DST: 3789 if (cmdlen != F_INSN_SIZE(struct in6_addr) + 3790 F_INSN_SIZE(ipfw_insn)) 3791 goto bad_size; 3792 break; 3793 3794 case O_FLOW6ID: 3795 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) + 3796 ((ipfw_insn_u32 *)cmd)->o.arg1) 3797 goto bad_size; 3798 break; 3799 3800 case O_IP6_SRC_MASK: 3801 case O_IP6_DST_MASK: 3802 if ( !(cmdlen & 1) || cmdlen > 127) 3803 goto bad_size; 3804 break; 3805 case O_ICMP6TYPE: 3806 if( cmdlen != F_INSN_SIZE( ipfw_insn_icmp6 ) ) 3807 goto bad_size; 3808 break; 3809#endif 3810 3811 default: 3812 switch (cmd->opcode) { 3813#ifndef INET6 3814 case O_IP6_SRC_ME: 3815 case O_IP6_DST_ME: 3816 case O_EXT_HDR: 3817 case O_IP6: 3818 case O_UNREACH6: 3819 case O_IP6_SRC: 3820 case O_IP6_DST: 3821 case O_FLOW6ID: 3822 case O_IP6_SRC_MASK: 3823 case O_IP6_DST_MASK: 3824 case O_ICMP6TYPE: 3825 printf("ipfw: no IPv6 support in kernel\n"); 3826 return EPROTONOSUPPORT; 3827#endif 3828 default: 3829 printf("ipfw: opcode %d, unknown opcode\n", 3830 cmd->opcode); 3831 return EINVAL; 3832 } 3833 } 3834 } 3835 if (have_action == 0) { 3836 printf("ipfw: missing action\n"); 3837 return EINVAL; 3838 } 3839 return 0; 3840 3841bad_size: 3842 printf("ipfw: opcode %d size %d wrong\n", 3843 cmd->opcode, cmdlen); 3844 return EINVAL; 3845} 3846 3847/* 3848 * Copy the static and dynamic rules to the supplied buffer 3849 * and return the amount of space actually used. 3850 */ 3851static size_t 3852ipfw_getrules(struct ip_fw_chain *chain, void *buf, size_t space) 3853{ 3854 char *bp = buf; 3855 char *ep = bp + space; 3856 struct ip_fw *rule; 3857 int i; 3858 3859 /* XXX this can take a long time and locking will block packet flow */ 3860 IPFW_RLOCK(chain); 3861 for (rule = chain->rules; rule ; rule = rule->next) { 3862 /* 3863 * Verify the entry fits in the buffer in case the 3864 * rules changed between calculating buffer space and 3865 * now. This would be better done using a generation 3866 * number but should suffice for now. 3867 */ 3868 i = RULESIZE(rule); 3869 if (bp + i <= ep) { 3870 bcopy(rule, bp, i); 3871 bcopy(&set_disable, &(((struct ip_fw *)bp)->next_rule), 3872 sizeof(set_disable)); 3873 bp += i; 3874 } 3875 } 3876 IPFW_RUNLOCK(chain); 3877 if (ipfw_dyn_v) { 3878 ipfw_dyn_rule *p, *last = NULL; 3879 3880 IPFW_DYN_LOCK(); 3881 for (i = 0 ; i < curr_dyn_buckets; i++) 3882 for (p = ipfw_dyn_v[i] ; p != NULL; p = p->next) { 3883 if (bp + sizeof *p <= ep) { 3884 ipfw_dyn_rule *dst = 3885 (ipfw_dyn_rule *)bp; 3886 bcopy(p, dst, sizeof *p); 3887 bcopy(&(p->rule->rulenum), &(dst->rule), 3888 sizeof(p->rule->rulenum)); 3889 /* 3890 * store a non-null value in "next". 3891 * The userland code will interpret a 3892 * NULL here as a marker 3893 * for the last dynamic rule. 3894 */ 3895 bcopy(&dst, &dst->next, sizeof(dst)); 3896 last = dst; 3897 dst->expire = 3898 TIME_LEQ(dst->expire, time_uptime) ? 3899 0 : dst->expire - time_uptime ; 3900 bp += sizeof(ipfw_dyn_rule); 3901 } 3902 } 3903 IPFW_DYN_UNLOCK(); 3904 if (last != NULL) /* mark last dynamic rule */ 3905 bzero(&last->next, sizeof(last)); 3906 } 3907 return (bp - (char *)buf); 3908} 3909 3910 3911/** 3912 * {set|get}sockopt parser. 3913 */ 3914static int 3915ipfw_ctl(struct sockopt *sopt) 3916{ 3917#define RULE_MAXSIZE (256*sizeof(u_int32_t)) 3918 int error, rule_num; 3919 size_t size; 3920 struct ip_fw *buf, *rule; 3921 u_int32_t rulenum[2]; 3922 3923 error = suser(sopt->sopt_td); 3924 if (error) 3925 return (error); 3926 3927 /* 3928 * Disallow modifications in really-really secure mode, but still allow 3929 * the logging counters to be reset. 3930 */ 3931 if (sopt->sopt_name == IP_FW_ADD || 3932 (sopt->sopt_dir == SOPT_SET && sopt->sopt_name != IP_FW_RESETLOG)) { 3933 error = securelevel_ge(sopt->sopt_td->td_ucred, 3); 3934 if (error) 3935 return (error); 3936 } 3937 3938 error = 0; 3939 3940 switch (sopt->sopt_name) { 3941 case IP_FW_GET: 3942 /* 3943 * pass up a copy of the current rules. Static rules 3944 * come first (the last of which has number IPFW_DEFAULT_RULE), 3945 * followed by a possibly empty list of dynamic rule. 3946 * The last dynamic rule has NULL in the "next" field. 3947 * 3948 * Note that the calculated size is used to bound the 3949 * amount of data returned to the user. The rule set may 3950 * change between calculating the size and returning the 3951 * data in which case we'll just return what fits. 3952 */ 3953 size = static_len; /* size of static rules */ 3954 if (ipfw_dyn_v) /* add size of dyn.rules */ 3955 size += (dyn_count * sizeof(ipfw_dyn_rule)); 3956 3957 /* 3958 * XXX todo: if the user passes a short length just to know 3959 * how much room is needed, do not bother filling up the 3960 * buffer, just jump to the sooptcopyout. 3961 */ 3962 buf = malloc(size, M_TEMP, M_WAITOK); 3963 error = sooptcopyout(sopt, buf, 3964 ipfw_getrules(&layer3_chain, buf, size)); 3965 free(buf, M_TEMP); 3966 break; 3967 3968 case IP_FW_FLUSH: 3969 /* 3970 * Normally we cannot release the lock on each iteration. 3971 * We could do it here only because we start from the head all 3972 * the times so there is no risk of missing some entries. 3973 * On the other hand, the risk is that we end up with 3974 * a very inconsistent ruleset, so better keep the lock 3975 * around the whole cycle. 3976 * 3977 * XXX this code can be improved by resetting the head of 3978 * the list to point to the default rule, and then freeing 3979 * the old list without the need for a lock. 3980 */ 3981 3982 IPFW_WLOCK(&layer3_chain); 3983 layer3_chain.reap = NULL; 3984 free_chain(&layer3_chain, 0 /* keep default rule */); 3985 rule = layer3_chain.reap; 3986 layer3_chain.reap = NULL; 3987 IPFW_WUNLOCK(&layer3_chain); 3988 if (rule != NULL) 3989 reap_rules(rule); 3990 break; 3991 3992 case IP_FW_ADD: 3993 rule = malloc(RULE_MAXSIZE, M_TEMP, M_WAITOK); 3994 error = sooptcopyin(sopt, rule, RULE_MAXSIZE, 3995 sizeof(struct ip_fw) ); 3996 if (error == 0) 3997 error = check_ipfw_struct(rule, sopt->sopt_valsize); 3998 if (error == 0) { 3999 error = add_rule(&layer3_chain, rule); 4000 size = RULESIZE(rule); 4001 if (!error && sopt->sopt_dir == SOPT_GET) 4002 error = sooptcopyout(sopt, rule, size); 4003 } 4004 free(rule, M_TEMP); 4005 break; 4006 4007 case IP_FW_DEL: 4008 /* 4009 * IP_FW_DEL is used for deleting single rules or sets, 4010 * and (ab)used to atomically manipulate sets. Argument size 4011 * is used to distinguish between the two: 4012 * sizeof(u_int32_t) 4013 * delete single rule or set of rules, 4014 * or reassign rules (or sets) to a different set. 4015 * 2*sizeof(u_int32_t) 4016 * atomic disable/enable sets. 4017 * first u_int32_t contains sets to be disabled, 4018 * second u_int32_t contains sets to be enabled. 4019 */ 4020 error = sooptcopyin(sopt, rulenum, 4021 2*sizeof(u_int32_t), sizeof(u_int32_t)); 4022 if (error) 4023 break; 4024 size = sopt->sopt_valsize; 4025 if (size == sizeof(u_int32_t)) /* delete or reassign */ 4026 error = del_entry(&layer3_chain, rulenum[0]); 4027 else if (size == 2*sizeof(u_int32_t)) /* set enable/disable */ 4028 set_disable = 4029 (set_disable | rulenum[0]) & ~rulenum[1] & 4030 ~(1<<RESVD_SET); /* set RESVD_SET always enabled */ 4031 else 4032 error = EINVAL; 4033 break; 4034 4035 case IP_FW_ZERO: 4036 case IP_FW_RESETLOG: /* argument is an int, the rule number */ 4037 rule_num = 0; 4038 if (sopt->sopt_val != 0) { 4039 error = sooptcopyin(sopt, &rule_num, 4040 sizeof(int), sizeof(int)); 4041 if (error) 4042 break; 4043 } 4044 error = zero_entry(&layer3_chain, rule_num, 4045 sopt->sopt_name == IP_FW_RESETLOG); 4046 break; 4047 4048 case IP_FW_TABLE_ADD: 4049 { 4050 ipfw_table_entry ent; 4051 4052 error = sooptcopyin(sopt, &ent, 4053 sizeof(ent), sizeof(ent)); 4054 if (error) 4055 break; 4056 error = add_table_entry(&layer3_chain, ent.tbl, 4057 ent.addr, ent.masklen, ent.value); 4058 } 4059 break; 4060 4061 case IP_FW_TABLE_DEL: 4062 { 4063 ipfw_table_entry ent; 4064 4065 error = sooptcopyin(sopt, &ent, 4066 sizeof(ent), sizeof(ent)); 4067 if (error) 4068 break; 4069 error = del_table_entry(&layer3_chain, ent.tbl, 4070 ent.addr, ent.masklen); 4071 } 4072 break; 4073 4074 case IP_FW_TABLE_FLUSH: 4075 { 4076 u_int16_t tbl; 4077 4078 error = sooptcopyin(sopt, &tbl, 4079 sizeof(tbl), sizeof(tbl)); 4080 if (error) 4081 break; 4082 IPFW_WLOCK(&layer3_chain); 4083 error = flush_table(&layer3_chain, tbl); 4084 IPFW_WUNLOCK(&layer3_chain); 4085 } 4086 break; 4087 4088 case IP_FW_TABLE_GETSIZE: 4089 { 4090 u_int32_t tbl, cnt; 4091 4092 if ((error = sooptcopyin(sopt, &tbl, sizeof(tbl), 4093 sizeof(tbl)))) 4094 break; 4095 IPFW_RLOCK(&layer3_chain); 4096 error = count_table(&layer3_chain, tbl, &cnt); 4097 IPFW_RUNLOCK(&layer3_chain); 4098 if (error) 4099 break; 4100 error = sooptcopyout(sopt, &cnt, sizeof(cnt)); 4101 } 4102 break; 4103 4104 case IP_FW_TABLE_LIST: 4105 { 4106 ipfw_table *tbl; 4107 4108 if (sopt->sopt_valsize < sizeof(*tbl)) { 4109 error = EINVAL; 4110 break; 4111 } 4112 size = sopt->sopt_valsize; 4113 tbl = malloc(size, M_TEMP, M_WAITOK); 4114 error = sooptcopyin(sopt, tbl, size, sizeof(*tbl)); 4115 if (error) { 4116 free(tbl, M_TEMP); 4117 break; 4118 } 4119 tbl->size = (size - sizeof(*tbl)) / 4120 sizeof(ipfw_table_entry); 4121 IPFW_RLOCK(&layer3_chain); 4122 error = dump_table(&layer3_chain, tbl); 4123 IPFW_RUNLOCK(&layer3_chain); 4124 if (error) { 4125 free(tbl, M_TEMP); 4126 break; 4127 } 4128 error = sooptcopyout(sopt, tbl, size); 4129 free(tbl, M_TEMP); 4130 } 4131 break; 4132 4133 default: 4134 printf("ipfw: ipfw_ctl invalid option %d\n", sopt->sopt_name); 4135 error = EINVAL; 4136 } 4137 4138 return (error); 4139#undef RULE_MAXSIZE 4140} 4141 4142/** 4143 * dummynet needs a reference to the default rule, because rules can be 4144 * deleted while packets hold a reference to them. When this happens, 4145 * dummynet changes the reference to the default rule (it could well be a 4146 * NULL pointer, but this way we do not need to check for the special 4147 * case, plus here he have info on the default behaviour). 4148 */ 4149struct ip_fw *ip_fw_default_rule; 4150 4151/* 4152 * This procedure is only used to handle keepalives. It is invoked 4153 * every dyn_keepalive_period 4154 */ 4155static void 4156ipfw_tick(void * __unused unused) 4157{ 4158 struct mbuf *m0, *m, *mnext, **mtailp; 4159 int i; 4160 ipfw_dyn_rule *q; 4161 4162 if (dyn_keepalive == 0 || ipfw_dyn_v == NULL || dyn_count == 0) 4163 goto done; 4164 4165 /* 4166 * We make a chain of packets to go out here -- not deferring 4167 * until after we drop the IPFW dynamic rule lock would result 4168 * in a lock order reversal with the normal packet input -> ipfw 4169 * call stack. 4170 */ 4171 m0 = NULL; 4172 mtailp = &m0; 4173 IPFW_DYN_LOCK(); 4174 for (i = 0 ; i < curr_dyn_buckets ; i++) { 4175 for (q = ipfw_dyn_v[i] ; q ; q = q->next ) { 4176 if (q->dyn_type == O_LIMIT_PARENT) 4177 continue; 4178 if (q->id.proto != IPPROTO_TCP) 4179 continue; 4180 if ( (q->state & BOTH_SYN) != BOTH_SYN) 4181 continue; 4182 if (TIME_LEQ( time_uptime+dyn_keepalive_interval, 4183 q->expire)) 4184 continue; /* too early */ 4185 if (TIME_LEQ(q->expire, time_uptime)) 4186 continue; /* too late, rule expired */ 4187 4188 *mtailp = send_pkt(&(q->id), q->ack_rev - 1, 4189 q->ack_fwd, TH_SYN); 4190 if (*mtailp != NULL) 4191 mtailp = &(*mtailp)->m_nextpkt; 4192 *mtailp = send_pkt(&(q->id), q->ack_fwd - 1, 4193 q->ack_rev, 0); 4194 if (*mtailp != NULL) 4195 mtailp = &(*mtailp)->m_nextpkt; 4196 } 4197 } 4198 IPFW_DYN_UNLOCK(); 4199 for (m = mnext = m0; m != NULL; m = mnext) { 4200 mnext = m->m_nextpkt; 4201 m->m_nextpkt = NULL; 4202 ip_output(m, NULL, NULL, 0, NULL, NULL); 4203 } 4204done: 4205 callout_reset(&ipfw_timeout, dyn_keepalive_period*hz, ipfw_tick, NULL); 4206} 4207 4208int 4209ipfw_init(void) 4210{ 4211 struct ip_fw default_rule; 4212 int error; 4213 4214#ifdef INET6 4215 /* Setup IPv6 fw sysctl tree. */ 4216 sysctl_ctx_init(&ip6_fw_sysctl_ctx); 4217 ip6_fw_sysctl_tree = SYSCTL_ADD_NODE(&ip6_fw_sysctl_ctx, 4218 SYSCTL_STATIC_CHILDREN(_net_inet6_ip6), OID_AUTO, "fw", 4219 CTLFLAG_RW | CTLFLAG_SECURE, 0, "Firewall"); 4220 SYSCTL_ADD_PROC(&ip6_fw_sysctl_ctx, SYSCTL_CHILDREN(ip6_fw_sysctl_tree), 4221 OID_AUTO, "enable", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3, 4222 &fw6_enable, 0, ipfw_chg_hook, "I", "Enable ipfw+6"); 4223 SYSCTL_ADD_INT(&ip6_fw_sysctl_ctx, SYSCTL_CHILDREN(ip6_fw_sysctl_tree), 4224 OID_AUTO, "deny_unknown_exthdrs", CTLFLAG_RW | CTLFLAG_SECURE, 4225 &fw_deny_unknown_exthdrs, 0, 4226 "Deny packets with unknown IPv6 Extension Headers"); 4227#endif 4228 4229 layer3_chain.rules = NULL; 4230 IPFW_LOCK_INIT(&layer3_chain); 4231 ipfw_dyn_rule_zone = uma_zcreate("IPFW dynamic rule zone", 4232 sizeof(ipfw_dyn_rule), NULL, NULL, NULL, NULL, 4233 UMA_ALIGN_PTR, 0); 4234 IPFW_DYN_LOCK_INIT(); 4235 callout_init(&ipfw_timeout, NET_CALLOUT_MPSAFE); 4236 4237 bzero(&default_rule, sizeof default_rule); 4238 4239 default_rule.act_ofs = 0; 4240 default_rule.rulenum = IPFW_DEFAULT_RULE; 4241 default_rule.cmd_len = 1; 4242 default_rule.set = RESVD_SET; 4243 4244 default_rule.cmd[0].len = 1; 4245 default_rule.cmd[0].opcode = 4246#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 4247 1 ? O_ACCEPT : 4248#endif 4249 O_DENY; 4250 4251 error = add_rule(&layer3_chain, &default_rule); 4252 if (error != 0) { 4253 printf("ipfw2: error %u initializing default rule " 4254 "(support disabled)\n", error); 4255 IPFW_DYN_LOCK_DESTROY(); 4256 IPFW_LOCK_DESTROY(&layer3_chain); 4257 uma_zdestroy(ipfw_dyn_rule_zone); 4258 return (error); 4259 } 4260 4261 ip_fw_default_rule = layer3_chain.rules; 4262 printf("ipfw2 " 4263#ifdef INET6 4264 "(+ipv6) " 4265#endif 4266 "initialized, divert %s, " 4267 "rule-based forwarding " 4268#ifdef IPFIREWALL_FORWARD 4269 "enabled, " 4270#else 4271 "disabled, " 4272#endif 4273 "default to %s, logging ", 4274#ifdef IPDIVERT 4275 "enabled", 4276#else 4277 "loadable", 4278#endif 4279 default_rule.cmd[0].opcode == O_ACCEPT ? "accept" : "deny"); 4280 4281#ifdef IPFIREWALL_VERBOSE 4282 fw_verbose = 1; 4283#endif 4284#ifdef IPFIREWALL_VERBOSE_LIMIT 4285 verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 4286#endif 4287 if (fw_verbose == 0) 4288 printf("disabled\n"); 4289 else if (verbose_limit == 0) 4290 printf("unlimited\n"); 4291 else 4292 printf("limited to %d packets/entry by default\n", 4293 verbose_limit); 4294 4295 error = init_tables(&layer3_chain); 4296 if (error) { 4297 IPFW_DYN_LOCK_DESTROY(); 4298 IPFW_LOCK_DESTROY(&layer3_chain); 4299 uma_zdestroy(ipfw_dyn_rule_zone); 4300 return (error); 4301 } 4302 ip_fw_ctl_ptr = ipfw_ctl; 4303 ip_fw_chk_ptr = ipfw_chk; 4304 callout_reset(&ipfw_timeout, hz, ipfw_tick, NULL); 4305 4306 return (0); 4307} 4308 4309void 4310ipfw_destroy(void) 4311{ 4312 struct ip_fw *reap; 4313 4314 ip_fw_chk_ptr = NULL; 4315 ip_fw_ctl_ptr = NULL; 4316 callout_drain(&ipfw_timeout); 4317 IPFW_WLOCK(&layer3_chain); 4318 flush_tables(&layer3_chain); 4319 layer3_chain.reap = NULL; 4320 free_chain(&layer3_chain, 1 /* kill default rule */); 4321 reap = layer3_chain.reap, layer3_chain.reap = NULL; 4322 IPFW_WUNLOCK(&layer3_chain); 4323 if (reap != NULL) 4324 reap_rules(reap); 4325 IPFW_DYN_LOCK_DESTROY(); 4326 uma_zdestroy(ipfw_dyn_rule_zone); 4327 IPFW_LOCK_DESTROY(&layer3_chain); 4328 4329#ifdef INET6 4330 /* Free IPv6 fw sysctl tree. */ 4331 sysctl_ctx_free(&ip6_fw_sysctl_ctx); 4332#endif 4333 4334 printf("IP firewall unloaded\n"); 4335} 4336