ip_fw2.c revision 155201
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 155201 2006-02-02 03:13:16Z csjp $ 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_ip6fw.h" 38#include "opt_ipdn.h" 39#include "opt_inet.h" 40#ifndef INET 41#error IPFIREWALL requires INET. 42#endif /* INET */ 43#endif 44#include "opt_inet6.h" 45#include "opt_ipsec.h" 46 47#include <sys/param.h> 48#include <sys/systm.h> 49#include <sys/condvar.h> 50#include <sys/malloc.h> 51#include <sys/mbuf.h> 52#include <sys/kernel.h> 53#include <sys/lock.h> 54#include <sys/jail.h> 55#include <sys/module.h> 56#include <sys/proc.h> 57#include <sys/rwlock.h> 58#include <sys/socket.h> 59#include <sys/socketvar.h> 60#include <sys/sysctl.h> 61#include <sys/syslog.h> 62#include <sys/ucred.h> 63#include <net/if.h> 64#include <net/radix.h> 65#include <net/route.h> 66#include <netinet/in.h> 67#include <netinet/in_systm.h> 68#include <netinet/in_var.h> 69#include <netinet/in_pcb.h> 70#include <netinet/ip.h> 71#include <netinet/ip_var.h> 72#include <netinet/ip_icmp.h> 73#include <netinet/ip_fw.h> 74#include <netinet/ip_divert.h> 75#include <netinet/ip_dummynet.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(rw, 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() */ 167 168#ifdef SYSCTL_NODE 169SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 170SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, enable, 171 CTLFLAG_RW | CTLFLAG_SECURE3, 172 &fw_enable, 0, "Enable ipfw"); 173SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, CTLFLAG_RW, 174 &autoinc_step, 0, "Rule number autincrement step"); 175SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 176 CTLFLAG_RW | CTLFLAG_SECURE3, 177 &fw_one_pass, 0, 178 "Only do a single pass through ipfw when using dummynet(4)"); 179SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW, 180 &fw_debug, 0, "Enable printing of debug ip_fw statements"); 181SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, 182 CTLFLAG_RW | CTLFLAG_SECURE3, 183 &fw_verbose, 0, "Log matches to ipfw rules"); 184SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, 185 &verbose_limit, 0, "Set upper limit of matches of ipfw rules logged"); 186 187/* 188 * Description of dynamic rules. 189 * 190 * Dynamic rules are stored in lists accessed through a hash table 191 * (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can 192 * be modified through the sysctl variable dyn_buckets which is 193 * updated when the table becomes empty. 194 * 195 * XXX currently there is only one list, ipfw_dyn. 196 * 197 * When a packet is received, its address fields are first masked 198 * with the mask defined for the rule, then hashed, then matched 199 * against the entries in the corresponding list. 200 * Dynamic rules can be used for different purposes: 201 * + stateful rules; 202 * + enforcing limits on the number of sessions; 203 * + in-kernel NAT (not implemented yet) 204 * 205 * The lifetime of dynamic rules is regulated by dyn_*_lifetime, 206 * measured in seconds and depending on the flags. 207 * 208 * The total number of dynamic rules is stored in dyn_count. 209 * The max number of dynamic rules is dyn_max. When we reach 210 * the maximum number of rules we do not create anymore. This is 211 * done to avoid consuming too much memory, but also too much 212 * time when searching on each packet (ideally, we should try instead 213 * to put a limit on the length of the list on each bucket...). 214 * 215 * Each dynamic rule holds a pointer to the parent ipfw rule so 216 * we know what action to perform. Dynamic rules are removed when 217 * the parent rule is deleted. XXX we should make them survive. 218 * 219 * There are some limitations with dynamic rules -- we do not 220 * obey the 'randomized match', and we do not do multiple 221 * passes through the firewall. XXX check the latter!!! 222 */ 223static ipfw_dyn_rule **ipfw_dyn_v = NULL; 224static u_int32_t dyn_buckets = 256; /* must be power of 2 */ 225static u_int32_t curr_dyn_buckets = 256; /* must be power of 2 */ 226 227static struct mtx ipfw_dyn_mtx; /* mutex guarding dynamic rules */ 228#define IPFW_DYN_LOCK_INIT() \ 229 mtx_init(&ipfw_dyn_mtx, "IPFW dynamic rules", NULL, MTX_DEF) 230#define IPFW_DYN_LOCK_DESTROY() mtx_destroy(&ipfw_dyn_mtx) 231#define IPFW_DYN_LOCK() mtx_lock(&ipfw_dyn_mtx) 232#define IPFW_DYN_UNLOCK() mtx_unlock(&ipfw_dyn_mtx) 233#define IPFW_DYN_LOCK_ASSERT() mtx_assert(&ipfw_dyn_mtx, MA_OWNED) 234 235/* 236 * Timeouts for various events in handing dynamic rules. 237 */ 238static u_int32_t dyn_ack_lifetime = 300; 239static u_int32_t dyn_syn_lifetime = 20; 240static u_int32_t dyn_fin_lifetime = 1; 241static u_int32_t dyn_rst_lifetime = 1; 242static u_int32_t dyn_udp_lifetime = 10; 243static u_int32_t dyn_short_lifetime = 5; 244 245/* 246 * Keepalives are sent if dyn_keepalive is set. They are sent every 247 * dyn_keepalive_period seconds, in the last dyn_keepalive_interval 248 * seconds of lifetime of a rule. 249 * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower 250 * than dyn_keepalive_period. 251 */ 252 253static u_int32_t dyn_keepalive_interval = 20; 254static u_int32_t dyn_keepalive_period = 5; 255static u_int32_t dyn_keepalive = 1; /* do send keepalives */ 256 257static u_int32_t static_count; /* # of static rules */ 258static u_int32_t static_len; /* size in bytes of static rules */ 259static u_int32_t dyn_count; /* # of dynamic rules */ 260static u_int32_t dyn_max = 4096; /* max # of dynamic rules */ 261 262SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLFLAG_RW, 263 &dyn_buckets, 0, "Number of dyn. buckets"); 264SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_RD, 265 &curr_dyn_buckets, 0, "Current Number of dyn. buckets"); 266SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_RD, 267 &dyn_count, 0, "Number of dyn. rules"); 268SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_RW, 269 &dyn_max, 0, "Max number of dyn. rules"); 270SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, CTLFLAG_RD, 271 &static_count, 0, "Number of static rules"); 272SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_RW, 273 &dyn_ack_lifetime, 0, "Lifetime of dyn. rules for acks"); 274SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_RW, 275 &dyn_syn_lifetime, 0, "Lifetime of dyn. rules for syn"); 276SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, CTLFLAG_RW, 277 &dyn_fin_lifetime, 0, "Lifetime of dyn. rules for fin"); 278SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, CTLFLAG_RW, 279 &dyn_rst_lifetime, 0, "Lifetime of dyn. rules for rst"); 280SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime, CTLFLAG_RW, 281 &dyn_udp_lifetime, 0, "Lifetime of dyn. rules for UDP"); 282SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_RW, 283 &dyn_short_lifetime, 0, "Lifetime of dyn. rules for other situations"); 284SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_keepalive, CTLFLAG_RW, 285 &dyn_keepalive, 0, "Enable keepalives for dyn. rules"); 286 287#ifdef INET6 288/* 289 * IPv6 specific variables 290 */ 291SYSCTL_DECL(_net_inet6_ip6); 292 293static struct sysctl_ctx_list ip6_fw_sysctl_ctx; 294static struct sysctl_oid *ip6_fw_sysctl_tree; 295#endif /* INET6 */ 296#endif /* SYSCTL_NODE */ 297 298static int fw_deny_unknown_exthdrs = 1; 299 300 301/* 302 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 303 * Other macros just cast void * into the appropriate type 304 */ 305#define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 306#define TCP(p) ((struct tcphdr *)(p)) 307#define UDP(p) ((struct udphdr *)(p)) 308#define ICMP(p) ((struct icmphdr *)(p)) 309#define ICMP6(p) ((struct icmp6_hdr *)(p)) 310 311static __inline int 312icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 313{ 314 int type = icmp->icmp_type; 315 316 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 317} 318 319#define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 320 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 321 322static int 323is_icmp_query(struct icmphdr *icmp) 324{ 325 int type = icmp->icmp_type; 326 327 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 328} 329#undef TT 330 331/* 332 * The following checks use two arrays of 8 or 16 bits to store the 333 * bits that we want set or clear, respectively. They are in the 334 * low and high half of cmd->arg1 or cmd->d[0]. 335 * 336 * We scan options and store the bits we find set. We succeed if 337 * 338 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 339 * 340 * The code is sometimes optimized not to store additional variables. 341 */ 342 343static int 344flags_match(ipfw_insn *cmd, u_int8_t bits) 345{ 346 u_char want_clear; 347 bits = ~bits; 348 349 if ( ((cmd->arg1 & 0xff) & bits) != 0) 350 return 0; /* some bits we want set were clear */ 351 want_clear = (cmd->arg1 >> 8) & 0xff; 352 if ( (want_clear & bits) != want_clear) 353 return 0; /* some bits we want clear were set */ 354 return 1; 355} 356 357static int 358ipopts_match(struct ip *ip, ipfw_insn *cmd) 359{ 360 int optlen, bits = 0; 361 u_char *cp = (u_char *)(ip + 1); 362 int x = (ip->ip_hl << 2) - sizeof (struct ip); 363 364 for (; x > 0; x -= optlen, cp += optlen) { 365 int opt = cp[IPOPT_OPTVAL]; 366 367 if (opt == IPOPT_EOL) 368 break; 369 if (opt == IPOPT_NOP) 370 optlen = 1; 371 else { 372 optlen = cp[IPOPT_OLEN]; 373 if (optlen <= 0 || optlen > x) 374 return 0; /* invalid or truncated */ 375 } 376 switch (opt) { 377 378 default: 379 break; 380 381 case IPOPT_LSRR: 382 bits |= IP_FW_IPOPT_LSRR; 383 break; 384 385 case IPOPT_SSRR: 386 bits |= IP_FW_IPOPT_SSRR; 387 break; 388 389 case IPOPT_RR: 390 bits |= IP_FW_IPOPT_RR; 391 break; 392 393 case IPOPT_TS: 394 bits |= IP_FW_IPOPT_TS; 395 break; 396 } 397 } 398 return (flags_match(cmd, bits)); 399} 400 401static int 402tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 403{ 404 int optlen, bits = 0; 405 u_char *cp = (u_char *)(tcp + 1); 406 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 407 408 for (; x > 0; x -= optlen, cp += optlen) { 409 int opt = cp[0]; 410 if (opt == TCPOPT_EOL) 411 break; 412 if (opt == TCPOPT_NOP) 413 optlen = 1; 414 else { 415 optlen = cp[1]; 416 if (optlen <= 0) 417 break; 418 } 419 420 switch (opt) { 421 422 default: 423 break; 424 425 case TCPOPT_MAXSEG: 426 bits |= IP_FW_TCPOPT_MSS; 427 break; 428 429 case TCPOPT_WINDOW: 430 bits |= IP_FW_TCPOPT_WINDOW; 431 break; 432 433 case TCPOPT_SACK_PERMITTED: 434 case TCPOPT_SACK: 435 bits |= IP_FW_TCPOPT_SACK; 436 break; 437 438 case TCPOPT_TIMESTAMP: 439 bits |= IP_FW_TCPOPT_TS; 440 break; 441 442 } 443 } 444 return (flags_match(cmd, bits)); 445} 446 447static int 448iface_match(struct ifnet *ifp, ipfw_insn_if *cmd) 449{ 450 if (ifp == NULL) /* no iface with this packet, match fails */ 451 return 0; 452 /* Check by name or by IP address */ 453 if (cmd->name[0] != '\0') { /* match by name */ 454 /* Check name */ 455 if (cmd->p.glob) { 456 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 457 return(1); 458 } else { 459 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 460 return(1); 461 } 462 } else { 463 struct ifaddr *ia; 464 465 /* XXX lock? */ 466 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 467 if (ia->ifa_addr == NULL) 468 continue; 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 for (mdc2 = mdc->if_addrlist.tqh_first; mdc2; 577 mdc2 = mdc2->ifa_list.tqe_next) { 578 if (!mdc2->ifa_addr) 579 continue; 580 if (mdc2->ifa_addr->sa_family == AF_INET6) { 581 fdm = (struct in6_ifaddr *)mdc2; 582 copia = fdm->ia_addr.sin6_addr; 583 /* need for leaving scope_id in the sock_addr */ 584 in6_clearscope(&copia); 585 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) 586 return 1; 587 } 588 } 589 return 0; 590} 591 592static int 593verify_path6(struct in6_addr *src, struct ifnet *ifp) 594{ 595 struct route_in6 ro; 596 struct sockaddr_in6 *dst; 597 598 bzero(&ro, sizeof(ro)); 599 600 dst = (struct sockaddr_in6 * )&(ro.ro_dst); 601 dst->sin6_family = AF_INET6; 602 dst->sin6_len = sizeof(*dst); 603 dst->sin6_addr = *src; 604 rtalloc_ign((struct route *)&ro, RTF_CLONING); 605 606 if (ro.ro_rt == NULL) 607 return 0; 608 609 /* 610 * if ifp is provided, check for equality with rtentry 611 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 612 * to support the case of sending packets to an address of our own. 613 * (where the former interface is the first argument of if_simloop() 614 * (=ifp), the latter is lo0) 615 */ 616 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 617 RTFREE(ro.ro_rt); 618 return 0; 619 } 620 621 /* if no ifp provided, check if rtentry is not default route */ 622 if (ifp == NULL && 623 IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) { 624 RTFREE(ro.ro_rt); 625 return 0; 626 } 627 628 /* or if this is a blackhole/reject route */ 629 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 630 RTFREE(ro.ro_rt); 631 return 0; 632 } 633 634 /* found valid route */ 635 RTFREE(ro.ro_rt); 636 return 1; 637 638} 639static __inline int 640hash_packet6(struct ipfw_flow_id *id) 641{ 642 u_int32_t i; 643 i = (id->dst_ip6.__u6_addr.__u6_addr32[0]) ^ 644 (id->dst_ip6.__u6_addr.__u6_addr32[1]) ^ 645 (id->dst_ip6.__u6_addr.__u6_addr32[2]) ^ 646 (id->dst_ip6.__u6_addr.__u6_addr32[3]) ^ 647 (id->dst_port) ^ (id->src_port) ^ (id->flow_id6); 648 return i; 649} 650 651static int 652is_icmp6_query(int icmp6_type) 653{ 654 if ((icmp6_type <= ICMP6_MAXTYPE) && 655 (icmp6_type == ICMP6_ECHO_REQUEST || 656 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 657 icmp6_type == ICMP6_WRUREQUEST || 658 icmp6_type == ICMP6_FQDN_QUERY || 659 icmp6_type == ICMP6_NI_QUERY)) 660 return (1); 661 662 return (0); 663} 664 665static void 666send_reject6(struct ip_fw_args *args, int code, u_short offset, u_int hlen) 667{ 668 if (code == ICMP6_UNREACH_RST && offset == 0 && 669 args->f_id.proto == IPPROTO_TCP) { 670 struct ip6_hdr *ip6; 671 struct tcphdr *tcp; 672 tcp_seq ack, seq; 673 int flags; 674 struct { 675 struct ip6_hdr ip6; 676 struct tcphdr th; 677 } ti; 678 679 if (args->m->m_len < (hlen+sizeof(struct tcphdr))) { 680 args->m = m_pullup(args->m, hlen+sizeof(struct tcphdr)); 681 if (args->m == NULL) 682 return; 683 } 684 685 ip6 = mtod(args->m, struct ip6_hdr *); 686 tcp = (struct tcphdr *)(mtod(args->m, char *) + hlen); 687 688 if ((tcp->th_flags & TH_RST) != 0) { 689 m_freem(args->m); 690 return; 691 } 692 693 ti.ip6 = *ip6; 694 ti.th = *tcp; 695 ti.th.th_seq = ntohl(ti.th.th_seq); 696 ti.th.th_ack = ntohl(ti.th.th_ack); 697 ti.ip6.ip6_nxt = IPPROTO_TCP; 698 699 if (ti.th.th_flags & TH_ACK) { 700 ack = 0; 701 seq = ti.th.th_ack; 702 flags = TH_RST; 703 } else { 704 ack = ti.th.th_seq; 705 if (((args->m)->m_flags & M_PKTHDR) != 0) { 706 ack += (args->m)->m_pkthdr.len - hlen 707 - (ti.th.th_off << 2); 708 } else if (ip6->ip6_plen) { 709 ack += ntohs(ip6->ip6_plen) + sizeof(*ip6) 710 - hlen - (ti.th.th_off << 2); 711 } else { 712 m_freem(args->m); 713 return; 714 } 715 if (tcp->th_flags & TH_SYN) 716 ack++; 717 seq = 0; 718 flags = TH_RST|TH_ACK; 719 } 720 bcopy(&ti, ip6, sizeof(ti)); 721 tcp_respond(NULL, ip6, (struct tcphdr *)(ip6 + 1), 722 args->m, ack, seq, flags); 723 724 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */ 725 icmp6_error(args->m, ICMP6_DST_UNREACH, code, 0); 726 727 } else 728 m_freem(args->m); 729 730 args->m = NULL; 731} 732 733#endif /* INET6 */ 734 735static u_int64_t norule_counter; /* counter for ipfw_log(NULL...) */ 736 737#define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0 738#define SNP(buf) buf, sizeof(buf) 739 740/* 741 * We enter here when we have a rule with O_LOG. 742 * XXX this function alone takes about 2Kbytes of code! 743 */ 744static void 745ipfw_log(struct ip_fw *f, u_int hlen, struct ip_fw_args *args, 746 struct mbuf *m, struct ifnet *oif, u_short offset) 747{ 748 struct ether_header *eh = args->eh; 749 char *action; 750 int limit_reached = 0; 751 char action2[40], proto[128], fragment[32]; 752 753 fragment[0] = '\0'; 754 proto[0] = '\0'; 755 756 if (f == NULL) { /* bogus pkt */ 757 if (verbose_limit != 0 && norule_counter >= verbose_limit) 758 return; 759 norule_counter++; 760 if (norule_counter == verbose_limit) 761 limit_reached = verbose_limit; 762 action = "Refuse"; 763 } else { /* O_LOG is the first action, find the real one */ 764 ipfw_insn *cmd = ACTION_PTR(f); 765 ipfw_insn_log *l = (ipfw_insn_log *)cmd; 766 767 if (l->max_log != 0 && l->log_left == 0) 768 return; 769 l->log_left--; 770 if (l->log_left == 0) 771 limit_reached = l->max_log; 772 cmd += F_LEN(cmd); /* point to first action */ 773 if (cmd->opcode == O_ALTQ) { 774 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 775 776 snprintf(SNPARGS(action2, 0), "Altq %d", 777 altq->qid); 778 cmd += F_LEN(cmd); 779 } 780 if (cmd->opcode == O_PROB) 781 cmd += F_LEN(cmd); 782 783 action = action2; 784 switch (cmd->opcode) { 785 case O_DENY: 786 action = "Deny"; 787 break; 788 789 case O_REJECT: 790 if (cmd->arg1==ICMP_REJECT_RST) 791 action = "Reset"; 792 else if (cmd->arg1==ICMP_UNREACH_HOST) 793 action = "Reject"; 794 else 795 snprintf(SNPARGS(action2, 0), "Unreach %d", 796 cmd->arg1); 797 break; 798 799 case O_UNREACH6: 800 if (cmd->arg1==ICMP6_UNREACH_RST) 801 action = "Reset"; 802 else 803 snprintf(SNPARGS(action2, 0), "Unreach %d", 804 cmd->arg1); 805 break; 806 807 case O_ACCEPT: 808 action = "Accept"; 809 break; 810 case O_COUNT: 811 action = "Count"; 812 break; 813 case O_DIVERT: 814 snprintf(SNPARGS(action2, 0), "Divert %d", 815 cmd->arg1); 816 break; 817 case O_TEE: 818 snprintf(SNPARGS(action2, 0), "Tee %d", 819 cmd->arg1); 820 break; 821 case O_SKIPTO: 822 snprintf(SNPARGS(action2, 0), "SkipTo %d", 823 cmd->arg1); 824 break; 825 case O_PIPE: 826 snprintf(SNPARGS(action2, 0), "Pipe %d", 827 cmd->arg1); 828 break; 829 case O_QUEUE: 830 snprintf(SNPARGS(action2, 0), "Queue %d", 831 cmd->arg1); 832 break; 833 case O_FORWARD_IP: { 834 ipfw_insn_sa *sa = (ipfw_insn_sa *)cmd; 835 int len; 836 837 len = snprintf(SNPARGS(action2, 0), "Forward to %s", 838 inet_ntoa(sa->sa.sin_addr)); 839 if (sa->sa.sin_port) 840 snprintf(SNPARGS(action2, len), ":%d", 841 sa->sa.sin_port); 842 } 843 break; 844 case O_NETGRAPH: 845 snprintf(SNPARGS(action2, 0), "Netgraph %d", 846 cmd->arg1); 847 break; 848 case O_NGTEE: 849 snprintf(SNPARGS(action2, 0), "Ngtee %d", 850 cmd->arg1); 851 break; 852 default: 853 action = "UNKNOWN"; 854 break; 855 } 856 } 857 858 if (hlen == 0) { /* non-ip */ 859 snprintf(SNPARGS(proto, 0), "MAC"); 860 861 } else { 862 int len; 863 char src[48], dst[48]; 864 struct icmphdr *icmp; 865 struct tcphdr *tcp; 866 struct udphdr *udp; 867 /* Initialize to make compiler happy. */ 868 struct ip *ip = NULL; 869#ifdef INET6 870 struct ip6_hdr *ip6 = NULL; 871 struct icmp6_hdr *icmp6; 872#endif 873 src[0] = '\0'; 874 dst[0] = '\0'; 875#ifdef INET6 876 if (args->f_id.addr_type == 6) { 877 snprintf(src, sizeof(src), "[%s]", 878 ip6_sprintf(&args->f_id.src_ip6)); 879 snprintf(dst, sizeof(dst), "[%s]", 880 ip6_sprintf(&args->f_id.dst_ip6)); 881 882 ip6 = (struct ip6_hdr *)mtod(m, struct ip6_hdr *); 883 tcp = (struct tcphdr *)(mtod(args->m, char *) + hlen); 884 udp = (struct udphdr *)(mtod(args->m, char *) + hlen); 885 } else 886#endif 887 { 888 ip = mtod(m, struct ip *); 889 tcp = L3HDR(struct tcphdr, ip); 890 udp = L3HDR(struct udphdr, ip); 891 892 inet_ntoa_r(ip->ip_src, src); 893 inet_ntoa_r(ip->ip_dst, dst); 894 } 895 896 switch (args->f_id.proto) { 897 case IPPROTO_TCP: 898 len = snprintf(SNPARGS(proto, 0), "TCP %s", src); 899 if (offset == 0) 900 snprintf(SNPARGS(proto, len), ":%d %s:%d", 901 ntohs(tcp->th_sport), 902 dst, 903 ntohs(tcp->th_dport)); 904 else 905 snprintf(SNPARGS(proto, len), " %s", dst); 906 break; 907 908 case IPPROTO_UDP: 909 len = snprintf(SNPARGS(proto, 0), "UDP %s", src); 910 if (offset == 0) 911 snprintf(SNPARGS(proto, len), ":%d %s:%d", 912 ntohs(udp->uh_sport), 913 dst, 914 ntohs(udp->uh_dport)); 915 else 916 snprintf(SNPARGS(proto, len), " %s", dst); 917 break; 918 919 case IPPROTO_ICMP: 920 icmp = L3HDR(struct icmphdr, ip); 921 if (offset == 0) 922 len = snprintf(SNPARGS(proto, 0), 923 "ICMP:%u.%u ", 924 icmp->icmp_type, icmp->icmp_code); 925 else 926 len = snprintf(SNPARGS(proto, 0), "ICMP "); 927 len += snprintf(SNPARGS(proto, len), "%s", src); 928 snprintf(SNPARGS(proto, len), " %s", dst); 929 break; 930#ifdef INET6 931 case IPPROTO_ICMPV6: 932 icmp6 = (struct icmp6_hdr *)(mtod(args->m, char *) + hlen); 933 if (offset == 0) 934 len = snprintf(SNPARGS(proto, 0), 935 "ICMPv6:%u.%u ", 936 icmp6->icmp6_type, icmp6->icmp6_code); 937 else 938 len = snprintf(SNPARGS(proto, 0), "ICMPv6 "); 939 len += snprintf(SNPARGS(proto, len), "%s", src); 940 snprintf(SNPARGS(proto, len), " %s", dst); 941 break; 942#endif 943 default: 944 len = snprintf(SNPARGS(proto, 0), "P:%d %s", 945 args->f_id.proto, src); 946 snprintf(SNPARGS(proto, len), " %s", dst); 947 break; 948 } 949 950#ifdef INET6 951 if (args->f_id.addr_type == 6) { 952 if (offset & (IP6F_OFF_MASK | IP6F_MORE_FRAG)) 953 snprintf(SNPARGS(fragment, 0), 954 " (frag %08x:%d@%d%s)", 955 args->f_id.frag_id6, 956 ntohs(ip6->ip6_plen) - hlen, 957 ntohs(offset & IP6F_OFF_MASK) << 3, 958 (offset & IP6F_MORE_FRAG) ? "+" : ""); 959 } else 960#endif 961 { 962 int ip_off, ip_len; 963 if (eh != NULL) { /* layer 2 packets are as on the wire */ 964 ip_off = ntohs(ip->ip_off); 965 ip_len = ntohs(ip->ip_len); 966 } else { 967 ip_off = ip->ip_off; 968 ip_len = ip->ip_len; 969 } 970 if (ip_off & (IP_MF | IP_OFFMASK)) 971 snprintf(SNPARGS(fragment, 0), 972 " (frag %d:%d@%d%s)", 973 ntohs(ip->ip_id), ip_len - (ip->ip_hl << 2), 974 offset << 3, 975 (ip_off & IP_MF) ? "+" : ""); 976 } 977 } 978 if (oif || m->m_pkthdr.rcvif) 979 log(LOG_SECURITY | LOG_INFO, 980 "ipfw: %d %s %s %s via %s%s\n", 981 f ? f->rulenum : -1, 982 action, proto, oif ? "out" : "in", 983 oif ? oif->if_xname : m->m_pkthdr.rcvif->if_xname, 984 fragment); 985 else 986 log(LOG_SECURITY | LOG_INFO, 987 "ipfw: %d %s %s [no if info]%s\n", 988 f ? f->rulenum : -1, 989 action, proto, fragment); 990 if (limit_reached) 991 log(LOG_SECURITY | LOG_NOTICE, 992 "ipfw: limit %d reached on entry %d\n", 993 limit_reached, f ? f->rulenum : -1); 994} 995 996/* 997 * IMPORTANT: the hash function for dynamic rules must be commutative 998 * in source and destination (ip,port), because rules are bidirectional 999 * and we want to find both in the same bucket. 1000 */ 1001static __inline int 1002hash_packet(struct ipfw_flow_id *id) 1003{ 1004 u_int32_t i; 1005 1006#ifdef INET6 1007 if (IS_IP6_FLOW_ID(id)) 1008 i = hash_packet6(id); 1009 else 1010#endif /* INET6 */ 1011 i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port); 1012 i &= (curr_dyn_buckets - 1); 1013 return i; 1014} 1015 1016/** 1017 * unlink a dynamic rule from a chain. prev is a pointer to 1018 * the previous one, q is a pointer to the rule to delete, 1019 * head is a pointer to the head of the queue. 1020 * Modifies q and potentially also head. 1021 */ 1022#define UNLINK_DYN_RULE(prev, head, q) { \ 1023 ipfw_dyn_rule *old_q = q; \ 1024 \ 1025 /* remove a refcount to the parent */ \ 1026 if (q->dyn_type == O_LIMIT) \ 1027 q->parent->count--; \ 1028 DEB(printf("ipfw: unlink entry 0x%08x %d -> 0x%08x %d, %d left\n",\ 1029 (q->id.src_ip), (q->id.src_port), \ 1030 (q->id.dst_ip), (q->id.dst_port), dyn_count-1 ); ) \ 1031 if (prev != NULL) \ 1032 prev->next = q = q->next; \ 1033 else \ 1034 head = q = q->next; \ 1035 dyn_count--; \ 1036 uma_zfree(ipfw_dyn_rule_zone, old_q); } 1037 1038#define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0) 1039 1040/** 1041 * Remove dynamic rules pointing to "rule", or all of them if rule == NULL. 1042 * 1043 * If keep_me == NULL, rules are deleted even if not expired, 1044 * otherwise only expired rules are removed. 1045 * 1046 * The value of the second parameter is also used to point to identify 1047 * a rule we absolutely do not want to remove (e.g. because we are 1048 * holding a reference to it -- this is the case with O_LIMIT_PARENT 1049 * rules). The pointer is only used for comparison, so any non-null 1050 * value will do. 1051 */ 1052static void 1053remove_dyn_rule(struct ip_fw *rule, ipfw_dyn_rule *keep_me) 1054{ 1055 static u_int32_t last_remove = 0; 1056 1057#define FORCE (keep_me == NULL) 1058 1059 ipfw_dyn_rule *prev, *q; 1060 int i, pass = 0, max_pass = 0; 1061 1062 IPFW_DYN_LOCK_ASSERT(); 1063 1064 if (ipfw_dyn_v == NULL || dyn_count == 0) 1065 return; 1066 /* do not expire more than once per second, it is useless */ 1067 if (!FORCE && last_remove == time_uptime) 1068 return; 1069 last_remove = time_uptime; 1070 1071 /* 1072 * because O_LIMIT refer to parent rules, during the first pass only 1073 * remove child and mark any pending LIMIT_PARENT, and remove 1074 * them in a second pass. 1075 */ 1076next_pass: 1077 for (i = 0 ; i < curr_dyn_buckets ; i++) { 1078 for (prev=NULL, q = ipfw_dyn_v[i] ; q ; ) { 1079 /* 1080 * Logic can become complex here, so we split tests. 1081 */ 1082 if (q == keep_me) 1083 goto next; 1084 if (rule != NULL && rule != q->rule) 1085 goto next; /* not the one we are looking for */ 1086 if (q->dyn_type == O_LIMIT_PARENT) { 1087 /* 1088 * handle parent in the second pass, 1089 * record we need one. 1090 */ 1091 max_pass = 1; 1092 if (pass == 0) 1093 goto next; 1094 if (FORCE && q->count != 0 ) { 1095 /* XXX should not happen! */ 1096 printf("ipfw: OUCH! cannot remove rule," 1097 " count %d\n", q->count); 1098 } 1099 } else { 1100 if (!FORCE && 1101 !TIME_LEQ( q->expire, time_uptime )) 1102 goto next; 1103 } 1104 if (q->dyn_type != O_LIMIT_PARENT || !q->count) { 1105 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q); 1106 continue; 1107 } 1108next: 1109 prev=q; 1110 q=q->next; 1111 } 1112 } 1113 if (pass++ < max_pass) 1114 goto next_pass; 1115} 1116 1117 1118/** 1119 * lookup a dynamic rule. 1120 */ 1121static ipfw_dyn_rule * 1122lookup_dyn_rule_locked(struct ipfw_flow_id *pkt, int *match_direction, 1123 struct tcphdr *tcp) 1124{ 1125 /* 1126 * stateful ipfw extensions. 1127 * Lookup into dynamic session queue 1128 */ 1129#define MATCH_REVERSE 0 1130#define MATCH_FORWARD 1 1131#define MATCH_NONE 2 1132#define MATCH_UNKNOWN 3 1133 int i, dir = MATCH_NONE; 1134 ipfw_dyn_rule *prev, *q=NULL; 1135 1136 IPFW_DYN_LOCK_ASSERT(); 1137 1138 if (ipfw_dyn_v == NULL) 1139 goto done; /* not found */ 1140 i = hash_packet( pkt ); 1141 for (prev=NULL, q = ipfw_dyn_v[i] ; q != NULL ; ) { 1142 if (q->dyn_type == O_LIMIT_PARENT && q->count) 1143 goto next; 1144 if (TIME_LEQ( q->expire, time_uptime)) { /* expire entry */ 1145 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q); 1146 continue; 1147 } 1148 if (pkt->proto == q->id.proto && 1149 q->dyn_type != O_LIMIT_PARENT) { 1150 if (IS_IP6_FLOW_ID(pkt)) { 1151 if (IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1152 &(q->id.src_ip6)) && 1153 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1154 &(q->id.dst_ip6)) && 1155 pkt->src_port == q->id.src_port && 1156 pkt->dst_port == q->id.dst_port ) { 1157 dir = MATCH_FORWARD; 1158 break; 1159 } 1160 if (IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1161 &(q->id.dst_ip6)) && 1162 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1163 &(q->id.src_ip6)) && 1164 pkt->src_port == q->id.dst_port && 1165 pkt->dst_port == q->id.src_port ) { 1166 dir = MATCH_REVERSE; 1167 break; 1168 } 1169 } else { 1170 if (pkt->src_ip == q->id.src_ip && 1171 pkt->dst_ip == q->id.dst_ip && 1172 pkt->src_port == q->id.src_port && 1173 pkt->dst_port == q->id.dst_port ) { 1174 dir = MATCH_FORWARD; 1175 break; 1176 } 1177 if (pkt->src_ip == q->id.dst_ip && 1178 pkt->dst_ip == q->id.src_ip && 1179 pkt->src_port == q->id.dst_port && 1180 pkt->dst_port == q->id.src_port ) { 1181 dir = MATCH_REVERSE; 1182 break; 1183 } 1184 } 1185 } 1186next: 1187 prev = q; 1188 q = q->next; 1189 } 1190 if (q == NULL) 1191 goto done; /* q = NULL, not found */ 1192 1193 if ( prev != NULL) { /* found and not in front */ 1194 prev->next = q->next; 1195 q->next = ipfw_dyn_v[i]; 1196 ipfw_dyn_v[i] = q; 1197 } 1198 if (pkt->proto == IPPROTO_TCP) { /* update state according to flags */ 1199 u_char flags = pkt->flags & (TH_FIN|TH_SYN|TH_RST); 1200 1201#define BOTH_SYN (TH_SYN | (TH_SYN << 8)) 1202#define BOTH_FIN (TH_FIN | (TH_FIN << 8)) 1203 q->state |= (dir == MATCH_FORWARD ) ? flags : (flags << 8); 1204 switch (q->state) { 1205 case TH_SYN: /* opening */ 1206 q->expire = time_uptime + dyn_syn_lifetime; 1207 break; 1208 1209 case BOTH_SYN: /* move to established */ 1210 case BOTH_SYN | TH_FIN : /* one side tries to close */ 1211 case BOTH_SYN | (TH_FIN << 8) : 1212 if (tcp) { 1213#define _SEQ_GE(a,b) ((int)(a) - (int)(b) >= 0) 1214 u_int32_t ack = ntohl(tcp->th_ack); 1215 if (dir == MATCH_FORWARD) { 1216 if (q->ack_fwd == 0 || _SEQ_GE(ack, q->ack_fwd)) 1217 q->ack_fwd = ack; 1218 else { /* ignore out-of-sequence */ 1219 break; 1220 } 1221 } else { 1222 if (q->ack_rev == 0 || _SEQ_GE(ack, q->ack_rev)) 1223 q->ack_rev = ack; 1224 else { /* ignore out-of-sequence */ 1225 break; 1226 } 1227 } 1228 } 1229 q->expire = time_uptime + dyn_ack_lifetime; 1230 break; 1231 1232 case BOTH_SYN | BOTH_FIN: /* both sides closed */ 1233 if (dyn_fin_lifetime >= dyn_keepalive_period) 1234 dyn_fin_lifetime = dyn_keepalive_period - 1; 1235 q->expire = time_uptime + dyn_fin_lifetime; 1236 break; 1237 1238 default: 1239#if 0 1240 /* 1241 * reset or some invalid combination, but can also 1242 * occur if we use keep-state the wrong way. 1243 */ 1244 if ( (q->state & ((TH_RST << 8)|TH_RST)) == 0) 1245 printf("invalid state: 0x%x\n", q->state); 1246#endif 1247 if (dyn_rst_lifetime >= dyn_keepalive_period) 1248 dyn_rst_lifetime = dyn_keepalive_period - 1; 1249 q->expire = time_uptime + dyn_rst_lifetime; 1250 break; 1251 } 1252 } else if (pkt->proto == IPPROTO_UDP) { 1253 q->expire = time_uptime + dyn_udp_lifetime; 1254 } else { 1255 /* other protocols */ 1256 q->expire = time_uptime + dyn_short_lifetime; 1257 } 1258done: 1259 if (match_direction) 1260 *match_direction = dir; 1261 return q; 1262} 1263 1264static ipfw_dyn_rule * 1265lookup_dyn_rule(struct ipfw_flow_id *pkt, int *match_direction, 1266 struct tcphdr *tcp) 1267{ 1268 ipfw_dyn_rule *q; 1269 1270 IPFW_DYN_LOCK(); 1271 q = lookup_dyn_rule_locked(pkt, match_direction, tcp); 1272 if (q == NULL) 1273 IPFW_DYN_UNLOCK(); 1274 /* NB: return table locked when q is not NULL */ 1275 return q; 1276} 1277 1278static void 1279realloc_dynamic_table(void) 1280{ 1281 IPFW_DYN_LOCK_ASSERT(); 1282 1283 /* 1284 * Try reallocation, make sure we have a power of 2 and do 1285 * not allow more than 64k entries. In case of overflow, 1286 * default to 1024. 1287 */ 1288 1289 if (dyn_buckets > 65536) 1290 dyn_buckets = 1024; 1291 if ((dyn_buckets & (dyn_buckets-1)) != 0) { /* not a power of 2 */ 1292 dyn_buckets = curr_dyn_buckets; /* reset */ 1293 return; 1294 } 1295 curr_dyn_buckets = dyn_buckets; 1296 if (ipfw_dyn_v != NULL) 1297 free(ipfw_dyn_v, M_IPFW); 1298 for (;;) { 1299 ipfw_dyn_v = malloc(curr_dyn_buckets * sizeof(ipfw_dyn_rule *), 1300 M_IPFW, M_NOWAIT | M_ZERO); 1301 if (ipfw_dyn_v != NULL || curr_dyn_buckets <= 2) 1302 break; 1303 curr_dyn_buckets /= 2; 1304 } 1305} 1306 1307/** 1308 * Install state of type 'type' for a dynamic session. 1309 * The hash table contains two type of rules: 1310 * - regular rules (O_KEEP_STATE) 1311 * - rules for sessions with limited number of sess per user 1312 * (O_LIMIT). When they are created, the parent is 1313 * increased by 1, and decreased on delete. In this case, 1314 * the third parameter is the parent rule and not the chain. 1315 * - "parent" rules for the above (O_LIMIT_PARENT). 1316 */ 1317static ipfw_dyn_rule * 1318add_dyn_rule(struct ipfw_flow_id *id, u_int8_t dyn_type, struct ip_fw *rule) 1319{ 1320 ipfw_dyn_rule *r; 1321 int i; 1322 1323 IPFW_DYN_LOCK_ASSERT(); 1324 1325 if (ipfw_dyn_v == NULL || 1326 (dyn_count == 0 && dyn_buckets != curr_dyn_buckets)) { 1327 realloc_dynamic_table(); 1328 if (ipfw_dyn_v == NULL) 1329 return NULL; /* failed ! */ 1330 } 1331 i = hash_packet(id); 1332 1333 r = uma_zalloc(ipfw_dyn_rule_zone, M_NOWAIT | M_ZERO); 1334 if (r == NULL) { 1335 printf ("ipfw: sorry cannot allocate state\n"); 1336 return NULL; 1337 } 1338 1339 /* increase refcount on parent, and set pointer */ 1340 if (dyn_type == O_LIMIT) { 1341 ipfw_dyn_rule *parent = (ipfw_dyn_rule *)rule; 1342 if ( parent->dyn_type != O_LIMIT_PARENT) 1343 panic("invalid parent"); 1344 parent->count++; 1345 r->parent = parent; 1346 rule = parent->rule; 1347 } 1348 1349 r->id = *id; 1350 r->expire = time_uptime + dyn_syn_lifetime; 1351 r->rule = rule; 1352 r->dyn_type = dyn_type; 1353 r->pcnt = r->bcnt = 0; 1354 r->count = 0; 1355 1356 r->bucket = i; 1357 r->next = ipfw_dyn_v[i]; 1358 ipfw_dyn_v[i] = r; 1359 dyn_count++; 1360 DEB(printf("ipfw: add dyn entry ty %d 0x%08x %d -> 0x%08x %d, total %d\n", 1361 dyn_type, 1362 (r->id.src_ip), (r->id.src_port), 1363 (r->id.dst_ip), (r->id.dst_port), 1364 dyn_count ); ) 1365 return r; 1366} 1367 1368/** 1369 * lookup dynamic parent rule using pkt and rule as search keys. 1370 * If the lookup fails, then install one. 1371 */ 1372static ipfw_dyn_rule * 1373lookup_dyn_parent(struct ipfw_flow_id *pkt, struct ip_fw *rule) 1374{ 1375 ipfw_dyn_rule *q; 1376 int i; 1377 1378 IPFW_DYN_LOCK_ASSERT(); 1379 1380 if (ipfw_dyn_v) { 1381 int is_v6 = IS_IP6_FLOW_ID(pkt); 1382 i = hash_packet( pkt ); 1383 for (q = ipfw_dyn_v[i] ; q != NULL ; q=q->next) 1384 if (q->dyn_type == O_LIMIT_PARENT && 1385 rule== q->rule && 1386 pkt->proto == q->id.proto && 1387 pkt->src_port == q->id.src_port && 1388 pkt->dst_port == q->id.dst_port && 1389 ( 1390 (is_v6 && 1391 IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1392 &(q->id.src_ip6)) && 1393 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1394 &(q->id.dst_ip6))) || 1395 (!is_v6 && 1396 pkt->src_ip == q->id.src_ip && 1397 pkt->dst_ip == q->id.dst_ip) 1398 ) 1399 ) { 1400 q->expire = time_uptime + dyn_short_lifetime; 1401 DEB(printf("ipfw: lookup_dyn_parent found 0x%p\n",q);) 1402 return q; 1403 } 1404 } 1405 return add_dyn_rule(pkt, O_LIMIT_PARENT, rule); 1406} 1407 1408/** 1409 * Install dynamic state for rule type cmd->o.opcode 1410 * 1411 * Returns 1 (failure) if state is not installed because of errors or because 1412 * session limitations are enforced. 1413 */ 1414static int 1415install_state(struct ip_fw *rule, ipfw_insn_limit *cmd, 1416 struct ip_fw_args *args) 1417{ 1418 static int last_log; 1419 1420 ipfw_dyn_rule *q; 1421 1422 DEB(printf("ipfw: install state type %d 0x%08x %u -> 0x%08x %u\n", 1423 cmd->o.opcode, 1424 (args->f_id.src_ip), (args->f_id.src_port), 1425 (args->f_id.dst_ip), (args->f_id.dst_port) );) 1426 1427 IPFW_DYN_LOCK(); 1428 1429 q = lookup_dyn_rule_locked(&args->f_id, NULL, NULL); 1430 1431 if (q != NULL) { /* should never occur */ 1432 if (last_log != time_uptime) { 1433 last_log = time_uptime; 1434 printf("ipfw: install_state: entry already present, done\n"); 1435 } 1436 IPFW_DYN_UNLOCK(); 1437 return 0; 1438 } 1439 1440 if (dyn_count >= dyn_max) 1441 /* 1442 * Run out of slots, try to remove any expired rule. 1443 */ 1444 remove_dyn_rule(NULL, (ipfw_dyn_rule *)1); 1445 1446 if (dyn_count >= dyn_max) { 1447 if (last_log != time_uptime) { 1448 last_log = time_uptime; 1449 printf("ipfw: install_state: Too many dynamic rules\n"); 1450 } 1451 IPFW_DYN_UNLOCK(); 1452 return 1; /* cannot install, notify caller */ 1453 } 1454 1455 switch (cmd->o.opcode) { 1456 case O_KEEP_STATE: /* bidir rule */ 1457 add_dyn_rule(&args->f_id, O_KEEP_STATE, rule); 1458 break; 1459 1460 case O_LIMIT: /* limit number of sessions */ 1461 { 1462 u_int16_t limit_mask = cmd->limit_mask; 1463 struct ipfw_flow_id id; 1464 ipfw_dyn_rule *parent; 1465 1466 DEB(printf("ipfw: installing dyn-limit rule %d\n", 1467 cmd->conn_limit);) 1468 1469 id.dst_ip = id.src_ip = 0; 1470 id.dst_port = id.src_port = 0; 1471 id.proto = args->f_id.proto; 1472 1473 if (IS_IP6_FLOW_ID (&(args->f_id))) { 1474 if (limit_mask & DYN_SRC_ADDR) 1475 id.src_ip6 = args->f_id.src_ip6; 1476 if (limit_mask & DYN_DST_ADDR) 1477 id.dst_ip6 = args->f_id.dst_ip6; 1478 } else { 1479 if (limit_mask & DYN_SRC_ADDR) 1480 id.src_ip = args->f_id.src_ip; 1481 if (limit_mask & DYN_DST_ADDR) 1482 id.dst_ip = args->f_id.dst_ip; 1483 } 1484 if (limit_mask & DYN_SRC_PORT) 1485 id.src_port = args->f_id.src_port; 1486 if (limit_mask & DYN_DST_PORT) 1487 id.dst_port = args->f_id.dst_port; 1488 parent = lookup_dyn_parent(&id, rule); 1489 if (parent == NULL) { 1490 printf("ipfw: add parent failed\n"); 1491 IPFW_DYN_UNLOCK(); 1492 return 1; 1493 } 1494 if (parent->count >= cmd->conn_limit) { 1495 /* 1496 * See if we can remove some expired rule. 1497 */ 1498 remove_dyn_rule(rule, parent); 1499 if (parent->count >= cmd->conn_limit) { 1500 if (fw_verbose && last_log != time_uptime) { 1501 last_log = time_uptime; 1502 log(LOG_SECURITY | LOG_DEBUG, 1503 "drop session, too many entries\n"); 1504 } 1505 IPFW_DYN_UNLOCK(); 1506 return 1; 1507 } 1508 } 1509 add_dyn_rule(&args->f_id, O_LIMIT, (struct ip_fw *)parent); 1510 } 1511 break; 1512 default: 1513 printf("ipfw: unknown dynamic rule type %u\n", cmd->o.opcode); 1514 IPFW_DYN_UNLOCK(); 1515 return 1; 1516 } 1517 lookup_dyn_rule_locked(&args->f_id, NULL, NULL); /* XXX just set lifetime */ 1518 IPFW_DYN_UNLOCK(); 1519 return 0; 1520} 1521 1522/* 1523 * Generate a TCP packet, containing either a RST or a keepalive. 1524 * When flags & TH_RST, we are sending a RST packet, because of a 1525 * "reset" action matched the packet. 1526 * Otherwise we are sending a keepalive, and flags & TH_ 1527 */ 1528static struct mbuf * 1529send_pkt(struct ipfw_flow_id *id, u_int32_t seq, u_int32_t ack, int flags) 1530{ 1531 struct mbuf *m; 1532 struct ip *ip; 1533 struct tcphdr *tcp; 1534 1535 MGETHDR(m, M_DONTWAIT, MT_DATA); 1536 if (m == 0) 1537 return (NULL); 1538 m->m_pkthdr.rcvif = (struct ifnet *)0; 1539 m->m_pkthdr.len = m->m_len = sizeof(struct ip) + sizeof(struct tcphdr); 1540 m->m_data += max_linkhdr; 1541 1542 ip = mtod(m, struct ip *); 1543 bzero(ip, m->m_len); 1544 tcp = (struct tcphdr *)(ip + 1); /* no IP options */ 1545 ip->ip_p = IPPROTO_TCP; 1546 tcp->th_off = 5; 1547 /* 1548 * Assume we are sending a RST (or a keepalive in the reverse 1549 * direction), swap src and destination addresses and ports. 1550 */ 1551 ip->ip_src.s_addr = htonl(id->dst_ip); 1552 ip->ip_dst.s_addr = htonl(id->src_ip); 1553 tcp->th_sport = htons(id->dst_port); 1554 tcp->th_dport = htons(id->src_port); 1555 if (flags & TH_RST) { /* we are sending a RST */ 1556 if (flags & TH_ACK) { 1557 tcp->th_seq = htonl(ack); 1558 tcp->th_ack = htonl(0); 1559 tcp->th_flags = TH_RST; 1560 } else { 1561 if (flags & TH_SYN) 1562 seq++; 1563 tcp->th_seq = htonl(0); 1564 tcp->th_ack = htonl(seq); 1565 tcp->th_flags = TH_RST | TH_ACK; 1566 } 1567 } else { 1568 /* 1569 * We are sending a keepalive. flags & TH_SYN determines 1570 * the direction, forward if set, reverse if clear. 1571 * NOTE: seq and ack are always assumed to be correct 1572 * as set by the caller. This may be confusing... 1573 */ 1574 if (flags & TH_SYN) { 1575 /* 1576 * we have to rewrite the correct addresses! 1577 */ 1578 ip->ip_dst.s_addr = htonl(id->dst_ip); 1579 ip->ip_src.s_addr = htonl(id->src_ip); 1580 tcp->th_dport = htons(id->dst_port); 1581 tcp->th_sport = htons(id->src_port); 1582 } 1583 tcp->th_seq = htonl(seq); 1584 tcp->th_ack = htonl(ack); 1585 tcp->th_flags = TH_ACK; 1586 } 1587 /* 1588 * set ip_len to the payload size so we can compute 1589 * the tcp checksum on the pseudoheader 1590 * XXX check this, could save a couple of words ? 1591 */ 1592 ip->ip_len = htons(sizeof(struct tcphdr)); 1593 tcp->th_sum = in_cksum(m, m->m_pkthdr.len); 1594 /* 1595 * now fill fields left out earlier 1596 */ 1597 ip->ip_ttl = ip_defttl; 1598 ip->ip_len = m->m_pkthdr.len; 1599 m->m_flags |= M_SKIP_FIREWALL; 1600 return (m); 1601} 1602 1603/* 1604 * sends a reject message, consuming the mbuf passed as an argument. 1605 */ 1606static void 1607send_reject(struct ip_fw_args *args, int code, u_short offset, int ip_len) 1608{ 1609 1610 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */ 1611 /* We need the IP header in host order for icmp_error(). */ 1612 if (args->eh != NULL) { 1613 struct ip *ip = mtod(args->m, struct ip *); 1614 ip->ip_len = ntohs(ip->ip_len); 1615 ip->ip_off = ntohs(ip->ip_off); 1616 } 1617 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 1618 } else if (offset == 0 && args->f_id.proto == IPPROTO_TCP) { 1619 struct tcphdr *const tcp = 1620 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 1621 if ( (tcp->th_flags & TH_RST) == 0) { 1622 struct mbuf *m; 1623 m = send_pkt(&(args->f_id), ntohl(tcp->th_seq), 1624 ntohl(tcp->th_ack), 1625 tcp->th_flags | TH_RST); 1626 if (m != NULL) 1627 ip_output(m, NULL, NULL, 0, NULL, NULL); 1628 } 1629 m_freem(args->m); 1630 } else 1631 m_freem(args->m); 1632 args->m = NULL; 1633} 1634 1635/** 1636 * 1637 * Given an ip_fw *, lookup_next_rule will return a pointer 1638 * to the next rule, which can be either the jump 1639 * target (for skipto instructions) or the next one in the list (in 1640 * all other cases including a missing jump target). 1641 * The result is also written in the "next_rule" field of the rule. 1642 * Backward jumps are not allowed, so start looking from the next 1643 * rule... 1644 * 1645 * This never returns NULL -- in case we do not have an exact match, 1646 * the next rule is returned. When the ruleset is changed, 1647 * pointers are flushed so we are always correct. 1648 */ 1649 1650static struct ip_fw * 1651lookup_next_rule(struct ip_fw *me) 1652{ 1653 struct ip_fw *rule = NULL; 1654 ipfw_insn *cmd; 1655 1656 /* look for action, in case it is a skipto */ 1657 cmd = ACTION_PTR(me); 1658 if (cmd->opcode == O_LOG) 1659 cmd += F_LEN(cmd); 1660 if (cmd->opcode == O_ALTQ) 1661 cmd += F_LEN(cmd); 1662 if ( cmd->opcode == O_SKIPTO ) 1663 for (rule = me->next; rule ; rule = rule->next) 1664 if (rule->rulenum >= cmd->arg1) 1665 break; 1666 if (rule == NULL) /* failure or not a skipto */ 1667 rule = me->next; 1668 me->next_rule = rule; 1669 return rule; 1670} 1671 1672static int 1673add_table_entry(struct ip_fw_chain *ch, uint16_t tbl, in_addr_t addr, 1674 uint8_t mlen, uint32_t value) 1675{ 1676 struct radix_node_head *rnh; 1677 struct table_entry *ent; 1678 1679 if (tbl >= IPFW_TABLES_MAX) 1680 return (EINVAL); 1681 rnh = ch->tables[tbl]; 1682 ent = malloc(sizeof(*ent), M_IPFW_TBL, M_NOWAIT | M_ZERO); 1683 if (ent == NULL) 1684 return (ENOMEM); 1685 ent->value = value; 1686 ent->addr.sin_len = ent->mask.sin_len = 8; 1687 ent->mask.sin_addr.s_addr = htonl(mlen ? ~((1 << (32 - mlen)) - 1) : 0); 1688 ent->addr.sin_addr.s_addr = addr & ent->mask.sin_addr.s_addr; 1689 IPFW_WLOCK(&layer3_chain); 1690 if (rnh->rnh_addaddr(&ent->addr, &ent->mask, rnh, (void *)ent) == 1691 NULL) { 1692 IPFW_WUNLOCK(&layer3_chain); 1693 free(ent, M_IPFW_TBL); 1694 return (EEXIST); 1695 } 1696 IPFW_WUNLOCK(&layer3_chain); 1697 return (0); 1698} 1699 1700static int 1701del_table_entry(struct ip_fw_chain *ch, uint16_t tbl, in_addr_t addr, 1702 uint8_t mlen) 1703{ 1704 struct radix_node_head *rnh; 1705 struct table_entry *ent; 1706 struct sockaddr_in sa, mask; 1707 1708 if (tbl >= IPFW_TABLES_MAX) 1709 return (EINVAL); 1710 rnh = ch->tables[tbl]; 1711 sa.sin_len = mask.sin_len = 8; 1712 mask.sin_addr.s_addr = htonl(mlen ? ~((1 << (32 - mlen)) - 1) : 0); 1713 sa.sin_addr.s_addr = addr & mask.sin_addr.s_addr; 1714 IPFW_WLOCK(ch); 1715 ent = (struct table_entry *)rnh->rnh_deladdr(&sa, &mask, rnh); 1716 if (ent == NULL) { 1717 IPFW_WUNLOCK(ch); 1718 return (ESRCH); 1719 } 1720 IPFW_WUNLOCK(ch); 1721 free(ent, M_IPFW_TBL); 1722 return (0); 1723} 1724 1725static int 1726flush_table_entry(struct radix_node *rn, void *arg) 1727{ 1728 struct radix_node_head * const rnh = arg; 1729 struct table_entry *ent; 1730 1731 ent = (struct table_entry *) 1732 rnh->rnh_deladdr(rn->rn_key, rn->rn_mask, rnh); 1733 if (ent != NULL) 1734 free(ent, M_IPFW_TBL); 1735 return (0); 1736} 1737 1738static int 1739flush_table(struct ip_fw_chain *ch, uint16_t tbl) 1740{ 1741 struct radix_node_head *rnh; 1742 1743 IPFW_WLOCK_ASSERT(ch); 1744 1745 if (tbl >= IPFW_TABLES_MAX) 1746 return (EINVAL); 1747 rnh = ch->tables[tbl]; 1748 KASSERT(rnh != NULL, ("NULL IPFW table")); 1749 rnh->rnh_walktree(rnh, flush_table_entry, rnh); 1750 return (0); 1751} 1752 1753static void 1754flush_tables(struct ip_fw_chain *ch) 1755{ 1756 uint16_t tbl; 1757 1758 IPFW_WLOCK_ASSERT(ch); 1759 1760 for (tbl = 0; tbl < IPFW_TABLES_MAX; tbl++) 1761 flush_table(ch, tbl); 1762} 1763 1764static int 1765init_tables(struct ip_fw_chain *ch) 1766{ 1767 int i; 1768 uint16_t j; 1769 1770 for (i = 0; i < IPFW_TABLES_MAX; i++) { 1771 if (!rn_inithead((void **)&ch->tables[i], 32)) { 1772 for (j = 0; j < i; j++) { 1773 (void) flush_table(ch, j); 1774 } 1775 return (ENOMEM); 1776 } 1777 } 1778 return (0); 1779} 1780 1781static int 1782lookup_table(struct ip_fw_chain *ch, uint16_t tbl, in_addr_t addr, 1783 uint32_t *val) 1784{ 1785 struct radix_node_head *rnh; 1786 struct table_entry *ent; 1787 struct sockaddr_in sa; 1788 1789 if (tbl >= IPFW_TABLES_MAX) 1790 return (0); 1791 rnh = ch->tables[tbl]; 1792 sa.sin_len = 8; 1793 sa.sin_addr.s_addr = addr; 1794 ent = (struct table_entry *)(rnh->rnh_lookup(&sa, NULL, rnh)); 1795 if (ent != NULL) { 1796 *val = ent->value; 1797 return (1); 1798 } 1799 return (0); 1800} 1801 1802static int 1803count_table_entry(struct radix_node *rn, void *arg) 1804{ 1805 u_int32_t * const cnt = arg; 1806 1807 (*cnt)++; 1808 return (0); 1809} 1810 1811static int 1812count_table(struct ip_fw_chain *ch, uint32_t tbl, uint32_t *cnt) 1813{ 1814 struct radix_node_head *rnh; 1815 1816 if (tbl >= IPFW_TABLES_MAX) 1817 return (EINVAL); 1818 rnh = ch->tables[tbl]; 1819 *cnt = 0; 1820 rnh->rnh_walktree(rnh, count_table_entry, cnt); 1821 return (0); 1822} 1823 1824static int 1825dump_table_entry(struct radix_node *rn, void *arg) 1826{ 1827 struct table_entry * const n = (struct table_entry *)rn; 1828 ipfw_table * const tbl = arg; 1829 ipfw_table_entry *ent; 1830 1831 if (tbl->cnt == tbl->size) 1832 return (1); 1833 ent = &tbl->ent[tbl->cnt]; 1834 ent->tbl = tbl->tbl; 1835 if (in_nullhost(n->mask.sin_addr)) 1836 ent->masklen = 0; 1837 else 1838 ent->masklen = 33 - ffs(ntohl(n->mask.sin_addr.s_addr)); 1839 ent->addr = n->addr.sin_addr.s_addr; 1840 ent->value = n->value; 1841 tbl->cnt++; 1842 return (0); 1843} 1844 1845static int 1846dump_table(struct ip_fw_chain *ch, ipfw_table *tbl) 1847{ 1848 struct radix_node_head *rnh; 1849 1850 IPFW_WLOCK_ASSERT(ch); 1851 1852 if (tbl->tbl >= IPFW_TABLES_MAX) 1853 return (EINVAL); 1854 rnh = ch->tables[tbl->tbl]; 1855 tbl->cnt = 0; 1856 rnh->rnh_walktree(rnh, dump_table_entry, tbl); 1857 return (0); 1858} 1859 1860static void 1861fill_ugid_cache(struct inpcb *inp, struct ip_fw_ugid *ugp) 1862{ 1863 struct ucred *cr; 1864 1865 if (inp->inp_socket != NULL) { 1866 cr = inp->inp_socket->so_cred; 1867 ugp->fw_prid = jailed(cr) ? 1868 cr->cr_prison->pr_id : -1; 1869 ugp->fw_uid = cr->cr_uid; 1870 ugp->fw_ngroups = cr->cr_ngroups; 1871 bcopy(cr->cr_groups, ugp->fw_groups, 1872 sizeof(ugp->fw_groups)); 1873 } 1874} 1875 1876static int 1877check_uidgid(ipfw_insn_u32 *insn, 1878 int proto, struct ifnet *oif, 1879 struct in_addr dst_ip, u_int16_t dst_port, 1880 struct in_addr src_ip, u_int16_t src_port, 1881 struct ip_fw_ugid *ugp, int *lookup, struct inpcb *inp) 1882{ 1883 struct inpcbinfo *pi; 1884 int wildcard; 1885 struct inpcb *pcb; 1886 int match; 1887 gid_t *gp; 1888 1889 /* 1890 * Check to see if the UDP or TCP stack supplied us with 1891 * the PCB. If so, rather then holding a lock and looking 1892 * up the PCB, we can use the one that was supplied. 1893 */ 1894 if (inp && *lookup == 0) { 1895 INP_LOCK_ASSERT(inp); 1896 if (inp->inp_socket != NULL) { 1897 fill_ugid_cache(inp, ugp); 1898 *lookup = 1; 1899 } 1900 } 1901 /* 1902 * If we have already been here and the packet has no 1903 * PCB entry associated with it, then we can safely 1904 * assume that this is a no match. 1905 */ 1906 if (*lookup == -1) 1907 return (0); 1908 if (proto == IPPROTO_TCP) { 1909 wildcard = 0; 1910 pi = &tcbinfo; 1911 } else if (proto == IPPROTO_UDP) { 1912 wildcard = 1; 1913 pi = &udbinfo; 1914 } else 1915 return 0; 1916 match = 0; 1917 if (*lookup == 0) { 1918 INP_INFO_RLOCK(pi); 1919 pcb = (oif) ? 1920 in_pcblookup_hash(pi, 1921 dst_ip, htons(dst_port), 1922 src_ip, htons(src_port), 1923 wildcard, oif) : 1924 in_pcblookup_hash(pi, 1925 src_ip, htons(src_port), 1926 dst_ip, htons(dst_port), 1927 wildcard, NULL); 1928 if (pcb != NULL) { 1929 INP_LOCK(pcb); 1930 if (pcb->inp_socket != NULL) { 1931 fill_ugid_cache(pcb, ugp); 1932 *lookup = 1; 1933 } 1934 INP_UNLOCK(pcb); 1935 } 1936 INP_INFO_RUNLOCK(pi); 1937 if (*lookup == 0) { 1938 /* 1939 * If the lookup did not yield any results, there 1940 * is no sense in coming back and trying again. So 1941 * we can set lookup to -1 and ensure that we wont 1942 * bother the pcb system again. 1943 */ 1944 *lookup = -1; 1945 return (0); 1946 } 1947 } 1948 if (insn->o.opcode == O_UID) 1949 match = (ugp->fw_uid == (uid_t)insn->d[0]); 1950 else if (insn->o.opcode == O_GID) { 1951 for (gp = ugp->fw_groups; 1952 gp < &ugp->fw_groups[ugp->fw_ngroups]; gp++) 1953 if (*gp == (gid_t)insn->d[0]) { 1954 match = 1; 1955 break; 1956 } 1957 } else if (insn->o.opcode == O_JAIL) 1958 match = (ugp->fw_prid == (int)insn->d[0]); 1959 return match; 1960} 1961 1962/* 1963 * The main check routine for the firewall. 1964 * 1965 * All arguments are in args so we can modify them and return them 1966 * back to the caller. 1967 * 1968 * Parameters: 1969 * 1970 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 1971 * Starts with the IP header. 1972 * args->eh (in) Mac header if present, or NULL for layer3 packet. 1973 * args->oif Outgoing interface, or NULL if packet is incoming. 1974 * The incoming interface is in the mbuf. (in) 1975 * args->divert_rule (in/out) 1976 * Skip up to the first rule past this rule number; 1977 * upon return, non-zero port number for divert or tee. 1978 * 1979 * args->rule Pointer to the last matching rule (in/out) 1980 * args->next_hop Socket we are forwarding to (out). 1981 * args->f_id Addresses grabbed from the packet (out) 1982 * args->cookie a cookie depending on rule action 1983 * 1984 * Return value: 1985 * 1986 * IP_FW_PASS the packet must be accepted 1987 * IP_FW_DENY the packet must be dropped 1988 * IP_FW_DIVERT divert packet, port in m_tag 1989 * IP_FW_TEE tee packet, port in m_tag 1990 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 1991 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 1992 * 1993 */ 1994 1995int 1996ipfw_chk(struct ip_fw_args *args) 1997{ 1998 /* 1999 * Local variables hold state during the processing of a packet. 2000 * 2001 * IMPORTANT NOTE: to speed up the processing of rules, there 2002 * are some assumption on the values of the variables, which 2003 * are documented here. Should you change them, please check 2004 * the implementation of the various instructions to make sure 2005 * that they still work. 2006 * 2007 * args->eh The MAC header. It is non-null for a layer2 2008 * packet, it is NULL for a layer-3 packet. 2009 * 2010 * m | args->m Pointer to the mbuf, as received from the caller. 2011 * It may change if ipfw_chk() does an m_pullup, or if it 2012 * consumes the packet because it calls send_reject(). 2013 * XXX This has to change, so that ipfw_chk() never modifies 2014 * or consumes the buffer. 2015 * ip is simply an alias of the value of m, and it is kept 2016 * in sync with it (the packet is supposed to start with 2017 * the ip header). 2018 */ 2019 struct mbuf *m = args->m; 2020 struct ip *ip = mtod(m, struct ip *); 2021 2022 /* 2023 * For rules which contain uid/gid or jail constraints, cache 2024 * a copy of the users credentials after the pcb lookup has been 2025 * executed. This will speed up the processing of rules with 2026 * these types of constraints, as well as decrease contention 2027 * on pcb related locks. 2028 */ 2029 struct ip_fw_ugid fw_ugid_cache; 2030 int ugid_lookup = 0; 2031 2032 /* 2033 * divinput_flags If non-zero, set to the IP_FW_DIVERT_*_FLAG 2034 * associated with a packet input on a divert socket. This 2035 * will allow to distinguish traffic and its direction when 2036 * it originates from a divert socket. 2037 */ 2038 u_int divinput_flags = 0; 2039 2040 /* 2041 * oif | args->oif If NULL, ipfw_chk has been called on the 2042 * inbound path (ether_input, ip_input). 2043 * If non-NULL, ipfw_chk has been called on the outbound path 2044 * (ether_output, ip_output). 2045 */ 2046 struct ifnet *oif = args->oif; 2047 2048 struct ip_fw *f = NULL; /* matching rule */ 2049 int retval = 0; 2050 2051 /* 2052 * hlen The length of the IP header. 2053 */ 2054 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 2055 2056 /* 2057 * offset The offset of a fragment. offset != 0 means that 2058 * we have a fragment at this offset of an IPv4 packet. 2059 * offset == 0 means that (if this is an IPv4 packet) 2060 * this is the first or only fragment. 2061 * For IPv6 offset == 0 means there is no Fragment Header. 2062 * If offset != 0 for IPv6 always use correct mask to 2063 * get the correct offset because we add IP6F_MORE_FRAG 2064 * to be able to dectect the first fragment which would 2065 * otherwise have offset = 0. 2066 */ 2067 u_short offset = 0; 2068 2069 /* 2070 * Local copies of addresses. They are only valid if we have 2071 * an IP packet. 2072 * 2073 * proto The protocol. Set to 0 for non-ip packets, 2074 * or to the protocol read from the packet otherwise. 2075 * proto != 0 means that we have an IPv4 packet. 2076 * 2077 * src_port, dst_port port numbers, in HOST format. Only 2078 * valid for TCP and UDP packets. 2079 * 2080 * src_ip, dst_ip ip addresses, in NETWORK format. 2081 * Only valid for IPv4 packets. 2082 */ 2083 u_int8_t proto; 2084 u_int16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 2085 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 2086 u_int16_t ip_len=0; 2087 int pktlen; 2088 2089 /* 2090 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 2091 * MATCH_NONE when checked and not matched (q = NULL), 2092 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) 2093 */ 2094 int dyn_dir = MATCH_UNKNOWN; 2095 ipfw_dyn_rule *q = NULL; 2096 struct ip_fw_chain *chain = &layer3_chain; 2097 struct m_tag *mtag; 2098 2099 /* 2100 * We store in ulp a pointer to the upper layer protocol header. 2101 * In the ipv4 case this is easy to determine from the header, 2102 * but for ipv6 we might have some additional headers in the middle. 2103 * ulp is NULL if not found. 2104 */ 2105 void *ulp = NULL; /* upper layer protocol pointer. */ 2106 /* XXX ipv6 variables */ 2107 int is_ipv6 = 0; 2108 u_int16_t ext_hd = 0; /* bits vector for extension header filtering */ 2109 /* end of ipv6 variables */ 2110 int is_ipv4 = 0; 2111 2112 if (m->m_flags & M_SKIP_FIREWALL) 2113 return (IP_FW_PASS); /* accept */ 2114 2115 pktlen = m->m_pkthdr.len; 2116 proto = args->f_id.proto = 0; /* mark f_id invalid */ 2117 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ 2118 2119/* 2120 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 2121 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 2122 * pointer might become stale after other pullups (but we never use it 2123 * this way). 2124 */ 2125#define PULLUP_TO(len, p, T) \ 2126do { \ 2127 int x = (len) + sizeof(T); \ 2128 if ((m)->m_len < x) { \ 2129 args->m = m = m_pullup(m, x); \ 2130 if (m == NULL) \ 2131 goto pullup_failed; \ 2132 } \ 2133 p = (mtod(m, char *) + (len)); \ 2134} while (0) 2135 2136 /* Identify IP packets and fill up variables. */ 2137 if (pktlen >= sizeof(struct ip6_hdr) && 2138 (args->eh == NULL || ntohs(args->eh->ether_type)==ETHERTYPE_IPV6) && 2139 mtod(m, struct ip *)->ip_v == 6) { 2140 is_ipv6 = 1; 2141 args->f_id.addr_type = 6; 2142 hlen = sizeof(struct ip6_hdr); 2143 proto = mtod(m, struct ip6_hdr *)->ip6_nxt; 2144 2145 /* Search extension headers to find upper layer protocols */ 2146 while (ulp == NULL) { 2147 switch (proto) { 2148 case IPPROTO_ICMPV6: 2149 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 2150 args->f_id.flags = ICMP6(ulp)->icmp6_type; 2151 break; 2152 2153 case IPPROTO_TCP: 2154 PULLUP_TO(hlen, ulp, struct tcphdr); 2155 dst_port = TCP(ulp)->th_dport; 2156 src_port = TCP(ulp)->th_sport; 2157 args->f_id.flags = TCP(ulp)->th_flags; 2158 break; 2159 2160 case IPPROTO_UDP: 2161 PULLUP_TO(hlen, ulp, struct udphdr); 2162 dst_port = UDP(ulp)->uh_dport; 2163 src_port = UDP(ulp)->uh_sport; 2164 break; 2165 2166 case IPPROTO_HOPOPTS: /* RFC 2460 */ 2167 PULLUP_TO(hlen, ulp, struct ip6_hbh); 2168 ext_hd |= EXT_HOPOPTS; 2169 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 2170 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 2171 ulp = NULL; 2172 break; 2173 2174 case IPPROTO_ROUTING: /* RFC 2460 */ 2175 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 2176 if (((struct ip6_rthdr *)ulp)->ip6r_type != 0) { 2177 printf("IPFW2: IPV6 - Unknown Routing " 2178 "Header type(%d)\n", 2179 ((struct ip6_rthdr *)ulp)->ip6r_type); 2180 if (fw_deny_unknown_exthdrs) 2181 return (IP_FW_DENY); 2182 break; 2183 } 2184 ext_hd |= EXT_ROUTING; 2185 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 2186 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 2187 ulp = NULL; 2188 break; 2189 2190 case IPPROTO_FRAGMENT: /* RFC 2460 */ 2191 PULLUP_TO(hlen, ulp, struct ip6_frag); 2192 ext_hd |= EXT_FRAGMENT; 2193 hlen += sizeof (struct ip6_frag); 2194 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 2195 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 2196 IP6F_OFF_MASK; 2197 /* Add IP6F_MORE_FRAG for offset of first 2198 * fragment to be != 0. */ 2199 offset |= ((struct ip6_frag *)ulp)->ip6f_offlg & 2200 IP6F_MORE_FRAG; 2201 if (offset == 0) { 2202 printf("IPFW2: IPV6 - Invalid Fragment " 2203 "Header\n"); 2204 if (fw_deny_unknown_exthdrs) 2205 return (IP_FW_DENY); 2206 break; 2207 } 2208 args->f_id.frag_id6 = 2209 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 2210 ulp = NULL; 2211 break; 2212 2213 case IPPROTO_DSTOPTS: /* RFC 2460 */ 2214 PULLUP_TO(hlen, ulp, struct ip6_hbh); 2215 ext_hd |= EXT_DSTOPTS; 2216 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 2217 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 2218 ulp = NULL; 2219 break; 2220 2221 case IPPROTO_AH: /* RFC 2402 */ 2222 PULLUP_TO(hlen, ulp, struct ip6_ext); 2223 ext_hd |= EXT_AH; 2224 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 2225 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 2226 ulp = NULL; 2227 break; 2228 2229 case IPPROTO_ESP: /* RFC 2406 */ 2230 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 2231 /* Anything past Seq# is variable length and 2232 * data past this ext. header is encrypted. */ 2233 ext_hd |= EXT_ESP; 2234 break; 2235 2236 case IPPROTO_NONE: /* RFC 2460 */ 2237 PULLUP_TO(hlen, ulp, struct ip6_ext); 2238 /* Packet ends here. if ip6e_len!=0 octets 2239 * must be ignored. */ 2240 break; 2241 2242 case IPPROTO_OSPFIGP: 2243 /* XXX OSPF header check? */ 2244 PULLUP_TO(hlen, ulp, struct ip6_ext); 2245 break; 2246 2247 default: 2248 printf("IPFW2: IPV6 - Unknown Extension " 2249 "Header(%d), ext_hd=%x\n", proto, ext_hd); 2250 if (fw_deny_unknown_exthdrs) 2251 return (IP_FW_DENY); 2252 break; 2253 } /*switch */ 2254 } 2255 args->f_id.src_ip6 = mtod(m,struct ip6_hdr *)->ip6_src; 2256 args->f_id.dst_ip6 = mtod(m,struct ip6_hdr *)->ip6_dst; 2257 args->f_id.src_ip = 0; 2258 args->f_id.dst_ip = 0; 2259 args->f_id.flow_id6 = ntohl(mtod(m, struct ip6_hdr *)->ip6_flow); 2260 } else if (pktlen >= sizeof(struct ip) && 2261 (args->eh == NULL || ntohs(args->eh->ether_type) == ETHERTYPE_IP) && 2262 mtod(m, struct ip *)->ip_v == 4) { 2263 is_ipv4 = 1; 2264 ip = mtod(m, struct ip *); 2265 hlen = ip->ip_hl << 2; 2266 args->f_id.addr_type = 4; 2267 2268 /* 2269 * Collect parameters into local variables for faster matching. 2270 */ 2271 proto = ip->ip_p; 2272 src_ip = ip->ip_src; 2273 dst_ip = ip->ip_dst; 2274 if (args->eh != NULL) { /* layer 2 packets are as on the wire */ 2275 offset = ntohs(ip->ip_off) & IP_OFFMASK; 2276 ip_len = ntohs(ip->ip_len); 2277 } else { 2278 offset = ip->ip_off & IP_OFFMASK; 2279 ip_len = ip->ip_len; 2280 } 2281 pktlen = ip_len < pktlen ? ip_len : pktlen; 2282 2283 if (offset == 0) { 2284 switch (proto) { 2285 case IPPROTO_TCP: 2286 PULLUP_TO(hlen, ulp, struct tcphdr); 2287 dst_port = TCP(ulp)->th_dport; 2288 src_port = TCP(ulp)->th_sport; 2289 args->f_id.flags = TCP(ulp)->th_flags; 2290 break; 2291 2292 case IPPROTO_UDP: 2293 PULLUP_TO(hlen, ulp, struct udphdr); 2294 dst_port = UDP(ulp)->uh_dport; 2295 src_port = UDP(ulp)->uh_sport; 2296 break; 2297 2298 case IPPROTO_ICMP: 2299 PULLUP_TO(hlen, ulp, struct icmphdr); 2300 args->f_id.flags = ICMP(ulp)->icmp_type; 2301 break; 2302 2303 default: 2304 break; 2305 } 2306 } 2307 2308 args->f_id.src_ip = ntohl(src_ip.s_addr); 2309 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 2310 } 2311#undef PULLUP_TO 2312 if (proto) { /* we may have port numbers, store them */ 2313 args->f_id.proto = proto; 2314 args->f_id.src_port = src_port = ntohs(src_port); 2315 args->f_id.dst_port = dst_port = ntohs(dst_port); 2316 } 2317 2318 IPFW_RLOCK(chain); 2319 mtag = m_tag_find(m, PACKET_TAG_DIVERT, NULL); 2320 if (args->rule) { 2321 /* 2322 * Packet has already been tagged. Look for the next rule 2323 * to restart processing. 2324 * 2325 * If fw_one_pass != 0 then just accept it. 2326 * XXX should not happen here, but optimized out in 2327 * the caller. 2328 */ 2329 if (fw_one_pass) { 2330 IPFW_RUNLOCK(chain); 2331 return (IP_FW_PASS); 2332 } 2333 2334 f = args->rule->next_rule; 2335 if (f == NULL) 2336 f = lookup_next_rule(args->rule); 2337 } else { 2338 /* 2339 * Find the starting rule. It can be either the first 2340 * one, or the one after divert_rule if asked so. 2341 */ 2342 int skipto = mtag ? divert_cookie(mtag) : 0; 2343 2344 f = chain->rules; 2345 if (args->eh == NULL && skipto != 0) { 2346 if (skipto >= IPFW_DEFAULT_RULE) { 2347 IPFW_RUNLOCK(chain); 2348 return (IP_FW_DENY); /* invalid */ 2349 } 2350 while (f && f->rulenum <= skipto) 2351 f = f->next; 2352 if (f == NULL) { /* drop packet */ 2353 IPFW_RUNLOCK(chain); 2354 return (IP_FW_DENY); 2355 } 2356 } 2357 } 2358 /* reset divert rule to avoid confusion later */ 2359 if (mtag) { 2360 divinput_flags = divert_info(mtag) & 2361 (IP_FW_DIVERT_OUTPUT_FLAG | IP_FW_DIVERT_LOOPBACK_FLAG); 2362 m_tag_delete(m, mtag); 2363 } 2364 2365 /* 2366 * Now scan the rules, and parse microinstructions for each rule. 2367 */ 2368 for (; f; f = f->next) { 2369 ipfw_insn *cmd; 2370 uint32_t tablearg = 0; 2371 int l, cmdlen, skip_or; /* skip rest of OR block */ 2372 2373again: 2374 if (set_disable & (1 << f->set) ) 2375 continue; 2376 2377 skip_or = 0; 2378 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 2379 l -= cmdlen, cmd += cmdlen) { 2380 int match; 2381 2382 /* 2383 * check_body is a jump target used when we find a 2384 * CHECK_STATE, and need to jump to the body of 2385 * the target rule. 2386 */ 2387 2388check_body: 2389 cmdlen = F_LEN(cmd); 2390 /* 2391 * An OR block (insn_1 || .. || insn_n) has the 2392 * F_OR bit set in all but the last instruction. 2393 * The first match will set "skip_or", and cause 2394 * the following instructions to be skipped until 2395 * past the one with the F_OR bit clear. 2396 */ 2397 if (skip_or) { /* skip this instruction */ 2398 if ((cmd->len & F_OR) == 0) 2399 skip_or = 0; /* next one is good */ 2400 continue; 2401 } 2402 match = 0; /* set to 1 if we succeed */ 2403 2404 switch (cmd->opcode) { 2405 /* 2406 * The first set of opcodes compares the packet's 2407 * fields with some pattern, setting 'match' if a 2408 * match is found. At the end of the loop there is 2409 * logic to deal with F_NOT and F_OR flags associated 2410 * with the opcode. 2411 */ 2412 case O_NOP: 2413 match = 1; 2414 break; 2415 2416 case O_FORWARD_MAC: 2417 printf("ipfw: opcode %d unimplemented\n", 2418 cmd->opcode); 2419 break; 2420 2421 case O_GID: 2422 case O_UID: 2423 case O_JAIL: 2424 /* 2425 * We only check offset == 0 && proto != 0, 2426 * as this ensures that we have a 2427 * packet with the ports info. 2428 */ 2429 if (offset!=0) 2430 break; 2431 if (is_ipv6) /* XXX to be fixed later */ 2432 break; 2433 if (proto == IPPROTO_TCP || 2434 proto == IPPROTO_UDP) 2435 match = check_uidgid( 2436 (ipfw_insn_u32 *)cmd, 2437 proto, oif, 2438 dst_ip, dst_port, 2439 src_ip, src_port, &fw_ugid_cache, 2440 &ugid_lookup, args->inp); 2441 break; 2442 2443 case O_RECV: 2444 match = iface_match(m->m_pkthdr.rcvif, 2445 (ipfw_insn_if *)cmd); 2446 break; 2447 2448 case O_XMIT: 2449 match = iface_match(oif, (ipfw_insn_if *)cmd); 2450 break; 2451 2452 case O_VIA: 2453 match = iface_match(oif ? oif : 2454 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd); 2455 break; 2456 2457 case O_MACADDR2: 2458 if (args->eh != NULL) { /* have MAC header */ 2459 u_int32_t *want = (u_int32_t *) 2460 ((ipfw_insn_mac *)cmd)->addr; 2461 u_int32_t *mask = (u_int32_t *) 2462 ((ipfw_insn_mac *)cmd)->mask; 2463 u_int32_t *hdr = (u_int32_t *)args->eh; 2464 2465 match = 2466 ( want[0] == (hdr[0] & mask[0]) && 2467 want[1] == (hdr[1] & mask[1]) && 2468 want[2] == (hdr[2] & mask[2]) ); 2469 } 2470 break; 2471 2472 case O_MAC_TYPE: 2473 if (args->eh != NULL) { 2474 u_int16_t t = 2475 ntohs(args->eh->ether_type); 2476 u_int16_t *p = 2477 ((ipfw_insn_u16 *)cmd)->ports; 2478 int i; 2479 2480 for (i = cmdlen - 1; !match && i>0; 2481 i--, p += 2) 2482 match = (t>=p[0] && t<=p[1]); 2483 } 2484 break; 2485 2486 case O_FRAG: 2487 match = (offset != 0); 2488 break; 2489 2490 case O_IN: /* "out" is "not in" */ 2491 match = (oif == NULL); 2492 break; 2493 2494 case O_LAYER2: 2495 match = (args->eh != NULL); 2496 break; 2497 2498 case O_DIVERTED: 2499 match = (cmd->arg1 & 1 && divinput_flags & 2500 IP_FW_DIVERT_LOOPBACK_FLAG) || 2501 (cmd->arg1 & 2 && divinput_flags & 2502 IP_FW_DIVERT_OUTPUT_FLAG); 2503 break; 2504 2505 case O_PROTO: 2506 /* 2507 * We do not allow an arg of 0 so the 2508 * check of "proto" only suffices. 2509 */ 2510 match = (proto == cmd->arg1); 2511 break; 2512 2513 case O_IP_SRC: 2514 match = is_ipv4 && 2515 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2516 src_ip.s_addr); 2517 break; 2518 2519 case O_IP_SRC_LOOKUP: 2520 case O_IP_DST_LOOKUP: 2521 if (is_ipv4) { 2522 uint32_t a = 2523 (cmd->opcode == O_IP_DST_LOOKUP) ? 2524 dst_ip.s_addr : src_ip.s_addr; 2525 uint32_t v; 2526 2527 match = lookup_table(chain, cmd->arg1, a, 2528 &v); 2529 if (!match) 2530 break; 2531 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 2532 match = 2533 ((ipfw_insn_u32 *)cmd)->d[0] == v; 2534 else 2535 tablearg = v; 2536 } 2537 break; 2538 2539 case O_IP_SRC_MASK: 2540 case O_IP_DST_MASK: 2541 if (is_ipv4) { 2542 uint32_t a = 2543 (cmd->opcode == O_IP_DST_MASK) ? 2544 dst_ip.s_addr : src_ip.s_addr; 2545 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 2546 int i = cmdlen-1; 2547 2548 for (; !match && i>0; i-= 2, p+= 2) 2549 match = (p[0] == (a & p[1])); 2550 } 2551 break; 2552 2553 case O_IP_SRC_ME: 2554 if (is_ipv4) { 2555 struct ifnet *tif; 2556 2557 INADDR_TO_IFP(src_ip, tif); 2558 match = (tif != NULL); 2559 } 2560 break; 2561 2562 case O_IP_DST_SET: 2563 case O_IP_SRC_SET: 2564 if (is_ipv4) { 2565 u_int32_t *d = (u_int32_t *)(cmd+1); 2566 u_int32_t addr = 2567 cmd->opcode == O_IP_DST_SET ? 2568 args->f_id.dst_ip : 2569 args->f_id.src_ip; 2570 2571 if (addr < d[0]) 2572 break; 2573 addr -= d[0]; /* subtract base */ 2574 match = (addr < cmd->arg1) && 2575 ( d[ 1 + (addr>>5)] & 2576 (1<<(addr & 0x1f)) ); 2577 } 2578 break; 2579 2580 case O_IP_DST: 2581 match = is_ipv4 && 2582 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2583 dst_ip.s_addr); 2584 break; 2585 2586 case O_IP_DST_ME: 2587 if (is_ipv4) { 2588 struct ifnet *tif; 2589 2590 INADDR_TO_IFP(dst_ip, tif); 2591 match = (tif != NULL); 2592 } 2593 break; 2594 2595 case O_IP_SRCPORT: 2596 case O_IP_DSTPORT: 2597 /* 2598 * offset == 0 && proto != 0 is enough 2599 * to guarantee that we have a 2600 * packet with port info. 2601 */ 2602 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP) 2603 && offset == 0) { 2604 u_int16_t x = 2605 (cmd->opcode == O_IP_SRCPORT) ? 2606 src_port : dst_port ; 2607 u_int16_t *p = 2608 ((ipfw_insn_u16 *)cmd)->ports; 2609 int i; 2610 2611 for (i = cmdlen - 1; !match && i>0; 2612 i--, p += 2) 2613 match = (x>=p[0] && x<=p[1]); 2614 } 2615 break; 2616 2617 case O_ICMPTYPE: 2618 match = (offset == 0 && proto==IPPROTO_ICMP && 2619 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 2620 break; 2621 2622#ifdef INET6 2623 case O_ICMP6TYPE: 2624 match = is_ipv6 && offset == 0 && 2625 proto==IPPROTO_ICMPV6 && 2626 icmp6type_match( 2627 ICMP6(ulp)->icmp6_type, 2628 (ipfw_insn_u32 *)cmd); 2629 break; 2630#endif /* INET6 */ 2631 2632 case O_IPOPT: 2633 match = (is_ipv4 && 2634 ipopts_match(mtod(m, struct ip *), cmd) ); 2635 break; 2636 2637 case O_IPVER: 2638 match = (is_ipv4 && 2639 cmd->arg1 == mtod(m, struct ip *)->ip_v); 2640 break; 2641 2642 case O_IPID: 2643 case O_IPLEN: 2644 case O_IPTTL: 2645 if (is_ipv4) { /* only for IP packets */ 2646 uint16_t x; 2647 uint16_t *p; 2648 int i; 2649 2650 if (cmd->opcode == O_IPLEN) 2651 x = ip_len; 2652 else if (cmd->opcode == O_IPTTL) 2653 x = mtod(m, struct ip *)->ip_ttl; 2654 else /* must be IPID */ 2655 x = ntohs(mtod(m, struct ip *)->ip_id); 2656 if (cmdlen == 1) { 2657 match = (cmd->arg1 == x); 2658 break; 2659 } 2660 /* otherwise we have ranges */ 2661 p = ((ipfw_insn_u16 *)cmd)->ports; 2662 i = cmdlen - 1; 2663 for (; !match && i>0; i--, p += 2) 2664 match = (x >= p[0] && x <= p[1]); 2665 } 2666 break; 2667 2668 case O_IPPRECEDENCE: 2669 match = (is_ipv4 && 2670 (cmd->arg1 == (mtod(m, struct ip *)->ip_tos & 0xe0)) ); 2671 break; 2672 2673 case O_IPTOS: 2674 match = (is_ipv4 && 2675 flags_match(cmd, mtod(m, struct ip *)->ip_tos)); 2676 break; 2677 2678 case O_TCPDATALEN: 2679 if (proto == IPPROTO_TCP && offset == 0) { 2680 struct tcphdr *tcp; 2681 uint16_t x; 2682 uint16_t *p; 2683 int i; 2684 2685 tcp = TCP(ulp); 2686 x = ip_len - 2687 ((ip->ip_hl + tcp->th_off) << 2); 2688 if (cmdlen == 1) { 2689 match = (cmd->arg1 == x); 2690 break; 2691 } 2692 /* otherwise we have ranges */ 2693 p = ((ipfw_insn_u16 *)cmd)->ports; 2694 i = cmdlen - 1; 2695 for (; !match && i>0; i--, p += 2) 2696 match = (x >= p[0] && x <= p[1]); 2697 } 2698 break; 2699 2700 case O_TCPFLAGS: 2701 match = (proto == IPPROTO_TCP && offset == 0 && 2702 flags_match(cmd, TCP(ulp)->th_flags)); 2703 break; 2704 2705 case O_TCPOPTS: 2706 match = (proto == IPPROTO_TCP && offset == 0 && 2707 tcpopts_match(TCP(ulp), cmd)); 2708 break; 2709 2710 case O_TCPSEQ: 2711 match = (proto == IPPROTO_TCP && offset == 0 && 2712 ((ipfw_insn_u32 *)cmd)->d[0] == 2713 TCP(ulp)->th_seq); 2714 break; 2715 2716 case O_TCPACK: 2717 match = (proto == IPPROTO_TCP && offset == 0 && 2718 ((ipfw_insn_u32 *)cmd)->d[0] == 2719 TCP(ulp)->th_ack); 2720 break; 2721 2722 case O_TCPWIN: 2723 match = (proto == IPPROTO_TCP && offset == 0 && 2724 cmd->arg1 == TCP(ulp)->th_win); 2725 break; 2726 2727 case O_ESTAB: 2728 /* reject packets which have SYN only */ 2729 /* XXX should i also check for TH_ACK ? */ 2730 match = (proto == IPPROTO_TCP && offset == 0 && 2731 (TCP(ulp)->th_flags & 2732 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 2733 break; 2734 2735 case O_ALTQ: { 2736 struct altq_tag *at; 2737 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 2738 2739 match = 1; 2740 mtag = m_tag_find(m, PACKET_TAG_PF_QID, NULL); 2741 if (mtag != NULL) 2742 break; 2743 mtag = m_tag_get(PACKET_TAG_PF_QID, 2744 sizeof(struct altq_tag), 2745 M_NOWAIT); 2746 if (mtag == NULL) { 2747 /* 2748 * Let the packet fall back to the 2749 * default ALTQ. 2750 */ 2751 break; 2752 } 2753 at = (struct altq_tag *)(mtag+1); 2754 at->qid = altq->qid; 2755 if (is_ipv4) 2756 at->af = AF_INET; 2757 else 2758 at->af = AF_LINK; 2759 at->hdr = ip; 2760 m_tag_prepend(m, mtag); 2761 break; 2762 } 2763 2764 case O_LOG: 2765 if (fw_verbose) 2766 ipfw_log(f, hlen, args, m, oif, offset); 2767 match = 1; 2768 break; 2769 2770 case O_PROB: 2771 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 2772 break; 2773 2774 case O_VERREVPATH: 2775 /* Outgoing packets automatically pass/match */ 2776 match = ((oif != NULL) || 2777 (m->m_pkthdr.rcvif == NULL) || 2778 ( 2779#ifdef INET6 2780 is_ipv6 ? 2781 verify_path6(&(args->f_id.src_ip6), 2782 m->m_pkthdr.rcvif) : 2783#endif 2784 verify_path(src_ip, m->m_pkthdr.rcvif))); 2785 break; 2786 2787 case O_VERSRCREACH: 2788 /* Outgoing packets automatically pass/match */ 2789 match = (hlen > 0 && ((oif != NULL) || 2790#ifdef INET6 2791 is_ipv6 ? 2792 verify_path6(&(args->f_id.src_ip6), 2793 NULL) : 2794#endif 2795 verify_path(src_ip, NULL))); 2796 break; 2797 2798 case O_ANTISPOOF: 2799 /* Outgoing packets automatically pass/match */ 2800 if (oif == NULL && hlen > 0 && 2801 ( (is_ipv4 && in_localaddr(src_ip)) 2802#ifdef INET6 2803 || (is_ipv6 && 2804 in6_localaddr(&(args->f_id.src_ip6))) 2805#endif 2806 )) 2807 match = 2808#ifdef INET6 2809 is_ipv6 ? verify_path6( 2810 &(args->f_id.src_ip6), 2811 m->m_pkthdr.rcvif) : 2812#endif 2813 verify_path(src_ip, 2814 m->m_pkthdr.rcvif); 2815 else 2816 match = 1; 2817 break; 2818 2819 case O_IPSEC: 2820#ifdef FAST_IPSEC 2821 match = (m_tag_find(m, 2822 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 2823#endif 2824#ifdef IPSEC 2825 match = (ipsec_getnhist(m) != 0); 2826#endif 2827 /* otherwise no match */ 2828 break; 2829 2830#ifdef INET6 2831 case O_IP6_SRC: 2832 match = is_ipv6 && 2833 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 2834 &((ipfw_insn_ip6 *)cmd)->addr6); 2835 break; 2836 2837 case O_IP6_DST: 2838 match = is_ipv6 && 2839 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 2840 &((ipfw_insn_ip6 *)cmd)->addr6); 2841 break; 2842 case O_IP6_SRC_MASK: 2843 if (is_ipv6) { 2844 ipfw_insn_ip6 *te = (ipfw_insn_ip6 *)cmd; 2845 struct in6_addr p = args->f_id.src_ip6; 2846 2847 APPLY_MASK(&p, &te->mask6); 2848 match = IN6_ARE_ADDR_EQUAL(&te->addr6, &p); 2849 } 2850 break; 2851 2852 case O_IP6_DST_MASK: 2853 if (is_ipv6) { 2854 ipfw_insn_ip6 *te = (ipfw_insn_ip6 *)cmd; 2855 struct in6_addr p = args->f_id.dst_ip6; 2856 2857 APPLY_MASK(&p, &te->mask6); 2858 match = IN6_ARE_ADDR_EQUAL(&te->addr6, &p); 2859 } 2860 break; 2861 2862 case O_IP6_SRC_ME: 2863 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6); 2864 break; 2865 2866 case O_IP6_DST_ME: 2867 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6); 2868 break; 2869 2870 case O_FLOW6ID: 2871 match = is_ipv6 && 2872 flow6id_match(args->f_id.flow_id6, 2873 (ipfw_insn_u32 *) cmd); 2874 break; 2875 2876 case O_EXT_HDR: 2877 match = is_ipv6 && 2878 (ext_hd & ((ipfw_insn *) cmd)->arg1); 2879 break; 2880 2881 case O_IP6: 2882 match = is_ipv6; 2883 break; 2884#endif 2885 2886 case O_IP4: 2887 match = is_ipv4; 2888 break; 2889 2890 /* 2891 * The second set of opcodes represents 'actions', 2892 * i.e. the terminal part of a rule once the packet 2893 * matches all previous patterns. 2894 * Typically there is only one action for each rule, 2895 * and the opcode is stored at the end of the rule 2896 * (but there are exceptions -- see below). 2897 * 2898 * In general, here we set retval and terminate the 2899 * outer loop (would be a 'break 3' in some language, 2900 * but we need to do a 'goto done'). 2901 * 2902 * Exceptions: 2903 * O_COUNT and O_SKIPTO actions: 2904 * instead of terminating, we jump to the next rule 2905 * ('goto next_rule', equivalent to a 'break 2'), 2906 * or to the SKIPTO target ('goto again' after 2907 * having set f, cmd and l), respectively. 2908 * 2909 * O_LOG and O_ALTQ action parameters: 2910 * perform some action and set match = 1; 2911 * 2912 * O_LIMIT and O_KEEP_STATE: these opcodes are 2913 * not real 'actions', and are stored right 2914 * before the 'action' part of the rule. 2915 * These opcodes try to install an entry in the 2916 * state tables; if successful, we continue with 2917 * the next opcode (match=1; break;), otherwise 2918 * the packet * must be dropped 2919 * ('goto done' after setting retval); 2920 * 2921 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2922 * cause a lookup of the state table, and a jump 2923 * to the 'action' part of the parent rule 2924 * ('goto check_body') if an entry is found, or 2925 * (CHECK_STATE only) a jump to the next rule if 2926 * the entry is not found ('goto next_rule'). 2927 * The result of the lookup is cached to make 2928 * further instances of these opcodes are 2929 * effectively NOPs. 2930 */ 2931 case O_LIMIT: 2932 case O_KEEP_STATE: 2933 if (install_state(f, 2934 (ipfw_insn_limit *)cmd, args)) { 2935 retval = IP_FW_DENY; 2936 goto done; /* error/limit violation */ 2937 } 2938 match = 1; 2939 break; 2940 2941 case O_PROBE_STATE: 2942 case O_CHECK_STATE: 2943 /* 2944 * dynamic rules are checked at the first 2945 * keep-state or check-state occurrence, 2946 * with the result being stored in dyn_dir. 2947 * The compiler introduces a PROBE_STATE 2948 * instruction for us when we have a 2949 * KEEP_STATE (because PROBE_STATE needs 2950 * to be run first). 2951 */ 2952 if (dyn_dir == MATCH_UNKNOWN && 2953 (q = lookup_dyn_rule(&args->f_id, 2954 &dyn_dir, proto == IPPROTO_TCP ? 2955 TCP(ulp) : NULL)) 2956 != NULL) { 2957 /* 2958 * Found dynamic entry, update stats 2959 * and jump to the 'action' part of 2960 * the parent rule. 2961 */ 2962 q->pcnt++; 2963 q->bcnt += pktlen; 2964 f = q->rule; 2965 cmd = ACTION_PTR(f); 2966 l = f->cmd_len - f->act_ofs; 2967 IPFW_DYN_UNLOCK(); 2968 goto check_body; 2969 } 2970 /* 2971 * Dynamic entry not found. If CHECK_STATE, 2972 * skip to next rule, if PROBE_STATE just 2973 * ignore and continue with next opcode. 2974 */ 2975 if (cmd->opcode == O_CHECK_STATE) 2976 goto next_rule; 2977 match = 1; 2978 break; 2979 2980 case O_ACCEPT: 2981 retval = 0; /* accept */ 2982 goto done; 2983 2984 case O_PIPE: 2985 case O_QUEUE: 2986 args->rule = f; /* report matching rule */ 2987 if (cmd->arg1 == IP_FW_TABLEARG) 2988 args->cookie = tablearg; 2989 else 2990 args->cookie = cmd->arg1; 2991 retval = IP_FW_DUMMYNET; 2992 goto done; 2993 2994 case O_DIVERT: 2995 case O_TEE: { 2996 struct divert_tag *dt; 2997 2998 if (args->eh) /* not on layer 2 */ 2999 break; 3000 mtag = m_tag_get(PACKET_TAG_DIVERT, 3001 sizeof(struct divert_tag), 3002 M_NOWAIT); 3003 if (mtag == NULL) { 3004 /* XXX statistic */ 3005 /* drop packet */ 3006 IPFW_RUNLOCK(chain); 3007 return (IP_FW_DENY); 3008 } 3009 dt = (struct divert_tag *)(mtag+1); 3010 dt->cookie = f->rulenum; 3011 if (cmd->arg1 == IP_FW_TABLEARG) 3012 dt->info = tablearg; 3013 else 3014 dt->info = cmd->arg1; 3015 m_tag_prepend(m, mtag); 3016 retval = (cmd->opcode == O_DIVERT) ? 3017 IP_FW_DIVERT : IP_FW_TEE; 3018 goto done; 3019 } 3020 3021 case O_COUNT: 3022 case O_SKIPTO: 3023 f->pcnt++; /* update stats */ 3024 f->bcnt += pktlen; 3025 f->timestamp = time_uptime; 3026 if (cmd->opcode == O_COUNT) 3027 goto next_rule; 3028 /* handle skipto */ 3029 if (f->next_rule == NULL) 3030 lookup_next_rule(f); 3031 f = f->next_rule; 3032 goto again; 3033 3034 case O_REJECT: 3035 /* 3036 * Drop the packet and send a reject notice 3037 * if the packet is not ICMP (or is an ICMP 3038 * query), and it is not multicast/broadcast. 3039 */ 3040 if (hlen > 0 && is_ipv4 && offset == 0 && 3041 (proto != IPPROTO_ICMP || 3042 is_icmp_query(ICMP(ulp))) && 3043 !(m->m_flags & (M_BCAST|M_MCAST)) && 3044 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 3045 send_reject(args, cmd->arg1, 3046 offset,ip_len); 3047 m = args->m; 3048 } 3049 /* FALLTHROUGH */ 3050#ifdef INET6 3051 case O_UNREACH6: 3052 if (hlen > 0 && is_ipv6 && 3053 (proto != IPPROTO_ICMPV6 || 3054 (is_icmp6_query(args->f_id.flags) == 1)) && 3055 !(m->m_flags & (M_BCAST|M_MCAST)) && 3056 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 3057 send_reject6(args, cmd->arg1, 3058 offset, hlen); 3059 m = args->m; 3060 } 3061 /* FALLTHROUGH */ 3062#endif 3063 case O_DENY: 3064 retval = IP_FW_DENY; 3065 goto done; 3066 3067 case O_FORWARD_IP: 3068 if (args->eh) /* not valid on layer2 pkts */ 3069 break; 3070 if (!q || dyn_dir == MATCH_FORWARD) 3071 args->next_hop = 3072 &((ipfw_insn_sa *)cmd)->sa; 3073 retval = IP_FW_PASS; 3074 goto done; 3075 3076 case O_NETGRAPH: 3077 case O_NGTEE: 3078 args->rule = f; /* report matching rule */ 3079 if (cmd->arg1 == IP_FW_TABLEARG) 3080 args->cookie = tablearg; 3081 else 3082 args->cookie = cmd->arg1; 3083 retval = (cmd->opcode == O_NETGRAPH) ? 3084 IP_FW_NETGRAPH : IP_FW_NGTEE; 3085 goto done; 3086 3087 default: 3088 panic("-- unknown opcode %d\n", cmd->opcode); 3089 } /* end of switch() on opcodes */ 3090 3091 if (cmd->len & F_NOT) 3092 match = !match; 3093 3094 if (match) { 3095 if (cmd->len & F_OR) 3096 skip_or = 1; 3097 } else { 3098 if (!(cmd->len & F_OR)) /* not an OR block, */ 3099 break; /* try next rule */ 3100 } 3101 3102 } /* end of inner for, scan opcodes */ 3103 3104next_rule:; /* try next rule */ 3105 3106 } /* end of outer for, scan rules */ 3107 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 3108 IPFW_RUNLOCK(chain); 3109 return (IP_FW_DENY); 3110 3111done: 3112 /* Update statistics */ 3113 f->pcnt++; 3114 f->bcnt += pktlen; 3115 f->timestamp = time_uptime; 3116 IPFW_RUNLOCK(chain); 3117 return (retval); 3118 3119pullup_failed: 3120 if (fw_verbose) 3121 printf("ipfw: pullup failed\n"); 3122 return (IP_FW_DENY); 3123} 3124 3125/* 3126 * When a rule is added/deleted, clear the next_rule pointers in all rules. 3127 * These will be reconstructed on the fly as packets are matched. 3128 */ 3129static void 3130flush_rule_ptrs(struct ip_fw_chain *chain) 3131{ 3132 struct ip_fw *rule; 3133 3134 IPFW_WLOCK_ASSERT(chain); 3135 3136 for (rule = chain->rules; rule; rule = rule->next) 3137 rule->next_rule = NULL; 3138} 3139 3140/* 3141 * Add a new rule to the list. Copy the rule into a malloc'ed area, then 3142 * possibly create a rule number and add the rule to the list. 3143 * Update the rule_number in the input struct so the caller knows it as well. 3144 */ 3145static int 3146add_rule(struct ip_fw_chain *chain, struct ip_fw *input_rule) 3147{ 3148 struct ip_fw *rule, *f, *prev; 3149 int l = RULESIZE(input_rule); 3150 3151 if (chain->rules == NULL && input_rule->rulenum != IPFW_DEFAULT_RULE) 3152 return (EINVAL); 3153 3154 rule = malloc(l, M_IPFW, M_NOWAIT | M_ZERO); 3155 if (rule == NULL) 3156 return (ENOSPC); 3157 3158 bcopy(input_rule, rule, l); 3159 3160 rule->next = NULL; 3161 rule->next_rule = NULL; 3162 3163 rule->pcnt = 0; 3164 rule->bcnt = 0; 3165 rule->timestamp = 0; 3166 3167 IPFW_WLOCK(chain); 3168 3169 if (chain->rules == NULL) { /* default rule */ 3170 chain->rules = rule; 3171 goto done; 3172 } 3173 3174 /* 3175 * If rulenum is 0, find highest numbered rule before the 3176 * default rule, and add autoinc_step 3177 */ 3178 if (autoinc_step < 1) 3179 autoinc_step = 1; 3180 else if (autoinc_step > 1000) 3181 autoinc_step = 1000; 3182 if (rule->rulenum == 0) { 3183 /* 3184 * locate the highest numbered rule before default 3185 */ 3186 for (f = chain->rules; f; f = f->next) { 3187 if (f->rulenum == IPFW_DEFAULT_RULE) 3188 break; 3189 rule->rulenum = f->rulenum; 3190 } 3191 if (rule->rulenum < IPFW_DEFAULT_RULE - autoinc_step) 3192 rule->rulenum += autoinc_step; 3193 input_rule->rulenum = rule->rulenum; 3194 } 3195 3196 /* 3197 * Now insert the new rule in the right place in the sorted list. 3198 */ 3199 for (prev = NULL, f = chain->rules; f; prev = f, f = f->next) { 3200 if (f->rulenum > rule->rulenum) { /* found the location */ 3201 if (prev) { 3202 rule->next = f; 3203 prev->next = rule; 3204 } else { /* head insert */ 3205 rule->next = chain->rules; 3206 chain->rules = rule; 3207 } 3208 break; 3209 } 3210 } 3211 flush_rule_ptrs(chain); 3212done: 3213 static_count++; 3214 static_len += l; 3215 IPFW_WUNLOCK(chain); 3216 DEB(printf("ipfw: installed rule %d, static count now %d\n", 3217 rule->rulenum, static_count);) 3218 return (0); 3219} 3220 3221/** 3222 * Remove a static rule (including derived * dynamic rules) 3223 * and place it on the ``reap list'' for later reclamation. 3224 * The caller is in charge of clearing rule pointers to avoid 3225 * dangling pointers. 3226 * @return a pointer to the next entry. 3227 * Arguments are not checked, so they better be correct. 3228 */ 3229static struct ip_fw * 3230remove_rule(struct ip_fw_chain *chain, struct ip_fw *rule, struct ip_fw *prev) 3231{ 3232 struct ip_fw *n; 3233 int l = RULESIZE(rule); 3234 3235 IPFW_WLOCK_ASSERT(chain); 3236 3237 n = rule->next; 3238 IPFW_DYN_LOCK(); 3239 remove_dyn_rule(rule, NULL /* force removal */); 3240 IPFW_DYN_UNLOCK(); 3241 if (prev == NULL) 3242 chain->rules = n; 3243 else 3244 prev->next = n; 3245 static_count--; 3246 static_len -= l; 3247 3248 rule->next = chain->reap; 3249 chain->reap = rule; 3250 3251 return n; 3252} 3253 3254/** 3255 * Reclaim storage associated with a list of rules. This is 3256 * typically the list created using remove_rule. 3257 */ 3258static void 3259reap_rules(struct ip_fw *head) 3260{ 3261 struct ip_fw *rule; 3262 3263 while ((rule = head) != NULL) { 3264 head = head->next; 3265 if (DUMMYNET_LOADED) 3266 ip_dn_ruledel_ptr(rule); 3267 free(rule, M_IPFW); 3268 } 3269} 3270 3271/* 3272 * Remove all rules from a chain (except rules in set RESVD_SET 3273 * unless kill_default = 1). The caller is responsible for 3274 * reclaiming storage for the rules left in chain->reap. 3275 */ 3276static void 3277free_chain(struct ip_fw_chain *chain, int kill_default) 3278{ 3279 struct ip_fw *prev, *rule; 3280 3281 IPFW_WLOCK_ASSERT(chain); 3282 3283 flush_rule_ptrs(chain); /* more efficient to do outside the loop */ 3284 for (prev = NULL, rule = chain->rules; rule ; ) 3285 if (kill_default || rule->set != RESVD_SET) 3286 rule = remove_rule(chain, rule, prev); 3287 else { 3288 prev = rule; 3289 rule = rule->next; 3290 } 3291} 3292 3293/** 3294 * Remove all rules with given number, and also do set manipulation. 3295 * Assumes chain != NULL && *chain != NULL. 3296 * 3297 * The argument is an u_int32_t. The low 16 bit are the rule or set number, 3298 * the next 8 bits are the new set, the top 8 bits are the command: 3299 * 3300 * 0 delete rules with given number 3301 * 1 delete rules with given set number 3302 * 2 move rules with given number to new set 3303 * 3 move rules with given set number to new set 3304 * 4 swap sets with given numbers 3305 */ 3306static int 3307del_entry(struct ip_fw_chain *chain, u_int32_t arg) 3308{ 3309 struct ip_fw *prev = NULL, *rule; 3310 u_int16_t rulenum; /* rule or old_set */ 3311 u_int8_t cmd, new_set; 3312 3313 rulenum = arg & 0xffff; 3314 cmd = (arg >> 24) & 0xff; 3315 new_set = (arg >> 16) & 0xff; 3316 3317 if (cmd > 4) 3318 return EINVAL; 3319 if (new_set > RESVD_SET) 3320 return EINVAL; 3321 if (cmd == 0 || cmd == 2) { 3322 if (rulenum >= IPFW_DEFAULT_RULE) 3323 return EINVAL; 3324 } else { 3325 if (rulenum > RESVD_SET) /* old_set */ 3326 return EINVAL; 3327 } 3328 3329 IPFW_WLOCK(chain); 3330 rule = chain->rules; 3331 chain->reap = NULL; 3332 switch (cmd) { 3333 case 0: /* delete rules with given number */ 3334 /* 3335 * locate first rule to delete 3336 */ 3337 for (; rule->rulenum < rulenum; prev = rule, rule = rule->next) 3338 ; 3339 if (rule->rulenum != rulenum) { 3340 IPFW_WUNLOCK(chain); 3341 return EINVAL; 3342 } 3343 3344 /* 3345 * flush pointers outside the loop, then delete all matching 3346 * rules. prev remains the same throughout the cycle. 3347 */ 3348 flush_rule_ptrs(chain); 3349 while (rule->rulenum == rulenum) 3350 rule = remove_rule(chain, rule, prev); 3351 break; 3352 3353 case 1: /* delete all rules with given set number */ 3354 flush_rule_ptrs(chain); 3355 rule = chain->rules; 3356 while (rule->rulenum < IPFW_DEFAULT_RULE) 3357 if (rule->set == rulenum) 3358 rule = remove_rule(chain, rule, prev); 3359 else { 3360 prev = rule; 3361 rule = rule->next; 3362 } 3363 break; 3364 3365 case 2: /* move rules with given number to new set */ 3366 rule = chain->rules; 3367 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3368 if (rule->rulenum == rulenum) 3369 rule->set = new_set; 3370 break; 3371 3372 case 3: /* move rules with given set number to new set */ 3373 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3374 if (rule->set == rulenum) 3375 rule->set = new_set; 3376 break; 3377 3378 case 4: /* swap two sets */ 3379 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3380 if (rule->set == rulenum) 3381 rule->set = new_set; 3382 else if (rule->set == new_set) 3383 rule->set = rulenum; 3384 break; 3385 } 3386 /* 3387 * Look for rules to reclaim. We grab the list before 3388 * releasing the lock then reclaim them w/o the lock to 3389 * avoid a LOR with dummynet. 3390 */ 3391 rule = chain->reap; 3392 chain->reap = NULL; 3393 IPFW_WUNLOCK(chain); 3394 if (rule) 3395 reap_rules(rule); 3396 return 0; 3397} 3398 3399/* 3400 * Clear counters for a specific rule. 3401 * The enclosing "table" is assumed locked. 3402 */ 3403static void 3404clear_counters(struct ip_fw *rule, int log_only) 3405{ 3406 ipfw_insn_log *l = (ipfw_insn_log *)ACTION_PTR(rule); 3407 3408 if (log_only == 0) { 3409 rule->bcnt = rule->pcnt = 0; 3410 rule->timestamp = 0; 3411 } 3412 if (l->o.opcode == O_LOG) 3413 l->log_left = l->max_log; 3414} 3415 3416/** 3417 * Reset some or all counters on firewall rules. 3418 * @arg frwl is null to clear all entries, or contains a specific 3419 * rule number. 3420 * @arg log_only is 1 if we only want to reset logs, zero otherwise. 3421 */ 3422static int 3423zero_entry(struct ip_fw_chain *chain, int rulenum, int log_only) 3424{ 3425 struct ip_fw *rule; 3426 char *msg; 3427 3428 IPFW_WLOCK(chain); 3429 if (rulenum == 0) { 3430 norule_counter = 0; 3431 for (rule = chain->rules; rule; rule = rule->next) 3432 clear_counters(rule, log_only); 3433 msg = log_only ? "ipfw: All logging counts reset.\n" : 3434 "ipfw: Accounting cleared.\n"; 3435 } else { 3436 int cleared = 0; 3437 /* 3438 * We can have multiple rules with the same number, so we 3439 * need to clear them all. 3440 */ 3441 for (rule = chain->rules; rule; rule = rule->next) 3442 if (rule->rulenum == rulenum) { 3443 while (rule && rule->rulenum == rulenum) { 3444 clear_counters(rule, log_only); 3445 rule = rule->next; 3446 } 3447 cleared = 1; 3448 break; 3449 } 3450 if (!cleared) { /* we did not find any matching rules */ 3451 IPFW_WUNLOCK(chain); 3452 return (EINVAL); 3453 } 3454 msg = log_only ? "ipfw: Entry %d logging count reset.\n" : 3455 "ipfw: Entry %d cleared.\n"; 3456 } 3457 IPFW_WUNLOCK(chain); 3458 3459 if (fw_verbose) 3460 log(LOG_SECURITY | LOG_NOTICE, msg, rulenum); 3461 return (0); 3462} 3463 3464/* 3465 * Check validity of the structure before insert. 3466 * Fortunately rules are simple, so this mostly need to check rule sizes. 3467 */ 3468static int 3469check_ipfw_struct(struct ip_fw *rule, int size) 3470{ 3471 int l, cmdlen = 0; 3472 int have_action=0; 3473 ipfw_insn *cmd; 3474 3475 if (size < sizeof(*rule)) { 3476 printf("ipfw: rule too short\n"); 3477 return (EINVAL); 3478 } 3479 /* first, check for valid size */ 3480 l = RULESIZE(rule); 3481 if (l != size) { 3482 printf("ipfw: size mismatch (have %d want %d)\n", size, l); 3483 return (EINVAL); 3484 } 3485 if (rule->act_ofs >= rule->cmd_len) { 3486 printf("ipfw: bogus action offset (%u > %u)\n", 3487 rule->act_ofs, rule->cmd_len - 1); 3488 return (EINVAL); 3489 } 3490 /* 3491 * Now go for the individual checks. Very simple ones, basically only 3492 * instruction sizes. 3493 */ 3494 for (l = rule->cmd_len, cmd = rule->cmd ; 3495 l > 0 ; l -= cmdlen, cmd += cmdlen) { 3496 cmdlen = F_LEN(cmd); 3497 if (cmdlen > l) { 3498 printf("ipfw: opcode %d size truncated\n", 3499 cmd->opcode); 3500 return EINVAL; 3501 } 3502 DEB(printf("ipfw: opcode %d\n", cmd->opcode);) 3503 switch (cmd->opcode) { 3504 case O_PROBE_STATE: 3505 case O_KEEP_STATE: 3506 case O_PROTO: 3507 case O_IP_SRC_ME: 3508 case O_IP_DST_ME: 3509 case O_LAYER2: 3510 case O_IN: 3511 case O_FRAG: 3512 case O_DIVERTED: 3513 case O_IPOPT: 3514 case O_IPTOS: 3515 case O_IPPRECEDENCE: 3516 case O_IPVER: 3517 case O_TCPWIN: 3518 case O_TCPFLAGS: 3519 case O_TCPOPTS: 3520 case O_ESTAB: 3521 case O_VERREVPATH: 3522 case O_VERSRCREACH: 3523 case O_ANTISPOOF: 3524 case O_IPSEC: 3525#ifdef INET6 3526 case O_IP6_SRC_ME: 3527 case O_IP6_DST_ME: 3528 case O_EXT_HDR: 3529 case O_IP6: 3530#endif 3531 case O_IP4: 3532 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 3533 goto bad_size; 3534 break; 3535 3536 case O_UID: 3537 case O_GID: 3538 case O_JAIL: 3539 case O_IP_SRC: 3540 case O_IP_DST: 3541 case O_TCPSEQ: 3542 case O_TCPACK: 3543 case O_PROB: 3544 case O_ICMPTYPE: 3545 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32)) 3546 goto bad_size; 3547 break; 3548 3549 case O_LIMIT: 3550 if (cmdlen != F_INSN_SIZE(ipfw_insn_limit)) 3551 goto bad_size; 3552 break; 3553 3554 case O_LOG: 3555 if (cmdlen != F_INSN_SIZE(ipfw_insn_log)) 3556 goto bad_size; 3557 3558 ((ipfw_insn_log *)cmd)->log_left = 3559 ((ipfw_insn_log *)cmd)->max_log; 3560 3561 break; 3562 3563 case O_IP_SRC_MASK: 3564 case O_IP_DST_MASK: 3565 /* only odd command lengths */ 3566 if ( !(cmdlen & 1) || cmdlen > 31) 3567 goto bad_size; 3568 break; 3569 3570 case O_IP_SRC_SET: 3571 case O_IP_DST_SET: 3572 if (cmd->arg1 == 0 || cmd->arg1 > 256) { 3573 printf("ipfw: invalid set size %d\n", 3574 cmd->arg1); 3575 return EINVAL; 3576 } 3577 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) + 3578 (cmd->arg1+31)/32 ) 3579 goto bad_size; 3580 break; 3581 3582 case O_IP_SRC_LOOKUP: 3583 case O_IP_DST_LOOKUP: 3584 if (cmd->arg1 >= IPFW_TABLES_MAX) { 3585 printf("ipfw: invalid table number %d\n", 3586 cmd->arg1); 3587 return (EINVAL); 3588 } 3589 if (cmdlen != F_INSN_SIZE(ipfw_insn) && 3590 cmdlen != F_INSN_SIZE(ipfw_insn_u32)) 3591 goto bad_size; 3592 break; 3593 3594 case O_MACADDR2: 3595 if (cmdlen != F_INSN_SIZE(ipfw_insn_mac)) 3596 goto bad_size; 3597 break; 3598 3599 case O_NOP: 3600 case O_IPID: 3601 case O_IPTTL: 3602 case O_IPLEN: 3603 case O_TCPDATALEN: 3604 if (cmdlen < 1 || cmdlen > 31) 3605 goto bad_size; 3606 break; 3607 3608 case O_MAC_TYPE: 3609 case O_IP_SRCPORT: 3610 case O_IP_DSTPORT: /* XXX artificial limit, 30 port pairs */ 3611 if (cmdlen < 2 || cmdlen > 31) 3612 goto bad_size; 3613 break; 3614 3615 case O_RECV: 3616 case O_XMIT: 3617 case O_VIA: 3618 if (cmdlen != F_INSN_SIZE(ipfw_insn_if)) 3619 goto bad_size; 3620 break; 3621 3622 case O_ALTQ: 3623 if (cmdlen != F_INSN_SIZE(ipfw_insn_altq)) 3624 goto bad_size; 3625 break; 3626 3627 case O_PIPE: 3628 case O_QUEUE: 3629 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 3630 goto bad_size; 3631 goto check_action; 3632 3633 case O_FORWARD_IP: 3634#ifdef IPFIREWALL_FORWARD 3635 if (cmdlen != F_INSN_SIZE(ipfw_insn_sa)) 3636 goto bad_size; 3637 goto check_action; 3638#else 3639 return EINVAL; 3640#endif 3641 3642 case O_DIVERT: 3643 case O_TEE: 3644 if (ip_divert_ptr == NULL) 3645 return EINVAL; 3646 else 3647 goto check_size; 3648 case O_NETGRAPH: 3649 case O_NGTEE: 3650 if (!NG_IPFW_LOADED) 3651 return EINVAL; 3652 else 3653 goto check_size; 3654 case O_FORWARD_MAC: /* XXX not implemented yet */ 3655 case O_CHECK_STATE: 3656 case O_COUNT: 3657 case O_ACCEPT: 3658 case O_DENY: 3659 case O_REJECT: 3660#ifdef INET6 3661 case O_UNREACH6: 3662#endif 3663 case O_SKIPTO: 3664check_size: 3665 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 3666 goto bad_size; 3667check_action: 3668 if (have_action) { 3669 printf("ipfw: opcode %d, multiple actions" 3670 " not allowed\n", 3671 cmd->opcode); 3672 return EINVAL; 3673 } 3674 have_action = 1; 3675 if (l != cmdlen) { 3676 printf("ipfw: opcode %d, action must be" 3677 " last opcode\n", 3678 cmd->opcode); 3679 return EINVAL; 3680 } 3681 break; 3682#ifdef INET6 3683 case O_IP6_SRC: 3684 case O_IP6_DST: 3685 if (cmdlen != F_INSN_SIZE(struct in6_addr) + 3686 F_INSN_SIZE(ipfw_insn)) 3687 goto bad_size; 3688 break; 3689 3690 case O_FLOW6ID: 3691 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) + 3692 ((ipfw_insn_u32 *)cmd)->o.arg1) 3693 goto bad_size; 3694 break; 3695 3696 case O_IP6_SRC_MASK: 3697 case O_IP6_DST_MASK: 3698 if ( !(cmdlen & 1) || cmdlen > 127) 3699 goto bad_size; 3700 break; 3701 case O_ICMP6TYPE: 3702 if( cmdlen != F_INSN_SIZE( ipfw_insn_icmp6 ) ) 3703 goto bad_size; 3704 break; 3705#endif 3706 3707 default: 3708 switch (cmd->opcode) { 3709#ifndef INET6 3710 case O_IP6_SRC_ME: 3711 case O_IP6_DST_ME: 3712 case O_EXT_HDR: 3713 case O_IP6: 3714 case O_UNREACH6: 3715 case O_IP6_SRC: 3716 case O_IP6_DST: 3717 case O_FLOW6ID: 3718 case O_IP6_SRC_MASK: 3719 case O_IP6_DST_MASK: 3720 case O_ICMP6TYPE: 3721 printf("ipfw: no IPv6 support in kernel\n"); 3722 return EPROTONOSUPPORT; 3723#endif 3724 default: 3725 printf("ipfw: opcode %d, unknown opcode\n", 3726 cmd->opcode); 3727 return EINVAL; 3728 } 3729 } 3730 } 3731 if (have_action == 0) { 3732 printf("ipfw: missing action\n"); 3733 return EINVAL; 3734 } 3735 return 0; 3736 3737bad_size: 3738 printf("ipfw: opcode %d size %d wrong\n", 3739 cmd->opcode, cmdlen); 3740 return EINVAL; 3741} 3742 3743/* 3744 * Copy the static and dynamic rules to the supplied buffer 3745 * and return the amount of space actually used. 3746 */ 3747static size_t 3748ipfw_getrules(struct ip_fw_chain *chain, void *buf, size_t space) 3749{ 3750 char *bp = buf; 3751 char *ep = bp + space; 3752 struct ip_fw *rule; 3753 int i; 3754 3755 /* XXX this can take a long time and locking will block packet flow */ 3756 IPFW_RLOCK(chain); 3757 for (rule = chain->rules; rule ; rule = rule->next) { 3758 /* 3759 * Verify the entry fits in the buffer in case the 3760 * rules changed between calculating buffer space and 3761 * now. This would be better done using a generation 3762 * number but should suffice for now. 3763 */ 3764 i = RULESIZE(rule); 3765 if (bp + i <= ep) { 3766 bcopy(rule, bp, i); 3767 bcopy(&set_disable, &(((struct ip_fw *)bp)->next_rule), 3768 sizeof(set_disable)); 3769 bp += i; 3770 } 3771 } 3772 IPFW_RUNLOCK(chain); 3773 if (ipfw_dyn_v) { 3774 ipfw_dyn_rule *p, *last = NULL; 3775 3776 IPFW_DYN_LOCK(); 3777 for (i = 0 ; i < curr_dyn_buckets; i++) 3778 for (p = ipfw_dyn_v[i] ; p != NULL; p = p->next) { 3779 if (bp + sizeof *p <= ep) { 3780 ipfw_dyn_rule *dst = 3781 (ipfw_dyn_rule *)bp; 3782 bcopy(p, dst, sizeof *p); 3783 bcopy(&(p->rule->rulenum), &(dst->rule), 3784 sizeof(p->rule->rulenum)); 3785 /* 3786 * store a non-null value in "next". 3787 * The userland code will interpret a 3788 * NULL here as a marker 3789 * for the last dynamic rule. 3790 */ 3791 bcopy(&dst, &dst->next, sizeof(dst)); 3792 last = dst; 3793 dst->expire = 3794 TIME_LEQ(dst->expire, time_uptime) ? 3795 0 : dst->expire - time_uptime ; 3796 bp += sizeof(ipfw_dyn_rule); 3797 } 3798 } 3799 IPFW_DYN_UNLOCK(); 3800 if (last != NULL) /* mark last dynamic rule */ 3801 bzero(&last->next, sizeof(last)); 3802 } 3803 return (bp - (char *)buf); 3804} 3805 3806 3807/** 3808 * {set|get}sockopt parser. 3809 */ 3810static int 3811ipfw_ctl(struct sockopt *sopt) 3812{ 3813#define RULE_MAXSIZE (256*sizeof(u_int32_t)) 3814 int error, rule_num; 3815 size_t size; 3816 struct ip_fw *buf, *rule; 3817 u_int32_t rulenum[2]; 3818 3819 error = suser(sopt->sopt_td); 3820 if (error) 3821 return (error); 3822 3823 /* 3824 * Disallow modifications in really-really secure mode, but still allow 3825 * the logging counters to be reset. 3826 */ 3827 if (sopt->sopt_name == IP_FW_ADD || 3828 (sopt->sopt_dir == SOPT_SET && sopt->sopt_name != IP_FW_RESETLOG)) { 3829 error = securelevel_ge(sopt->sopt_td->td_ucred, 3); 3830 if (error) 3831 return (error); 3832 } 3833 3834 error = 0; 3835 3836 switch (sopt->sopt_name) { 3837 case IP_FW_GET: 3838 /* 3839 * pass up a copy of the current rules. Static rules 3840 * come first (the last of which has number IPFW_DEFAULT_RULE), 3841 * followed by a possibly empty list of dynamic rule. 3842 * The last dynamic rule has NULL in the "next" field. 3843 * 3844 * Note that the calculated size is used to bound the 3845 * amount of data returned to the user. The rule set may 3846 * change between calculating the size and returning the 3847 * data in which case we'll just return what fits. 3848 */ 3849 size = static_len; /* size of static rules */ 3850 if (ipfw_dyn_v) /* add size of dyn.rules */ 3851 size += (dyn_count * sizeof(ipfw_dyn_rule)); 3852 3853 /* 3854 * XXX todo: if the user passes a short length just to know 3855 * how much room is needed, do not bother filling up the 3856 * buffer, just jump to the sooptcopyout. 3857 */ 3858 buf = malloc(size, M_TEMP, M_WAITOK); 3859 error = sooptcopyout(sopt, buf, 3860 ipfw_getrules(&layer3_chain, buf, size)); 3861 free(buf, M_TEMP); 3862 break; 3863 3864 case IP_FW_FLUSH: 3865 /* 3866 * Normally we cannot release the lock on each iteration. 3867 * We could do it here only because we start from the head all 3868 * the times so there is no risk of missing some entries. 3869 * On the other hand, the risk is that we end up with 3870 * a very inconsistent ruleset, so better keep the lock 3871 * around the whole cycle. 3872 * 3873 * XXX this code can be improved by resetting the head of 3874 * the list to point to the default rule, and then freeing 3875 * the old list without the need for a lock. 3876 */ 3877 3878 IPFW_WLOCK(&layer3_chain); 3879 layer3_chain.reap = NULL; 3880 free_chain(&layer3_chain, 0 /* keep default rule */); 3881 rule = layer3_chain.reap, layer3_chain.reap = NULL; 3882 IPFW_WUNLOCK(&layer3_chain); 3883 if (layer3_chain.reap != NULL) 3884 reap_rules(rule); 3885 break; 3886 3887 case IP_FW_ADD: 3888 rule = malloc(RULE_MAXSIZE, M_TEMP, M_WAITOK); 3889 error = sooptcopyin(sopt, rule, RULE_MAXSIZE, 3890 sizeof(struct ip_fw) ); 3891 if (error == 0) 3892 error = check_ipfw_struct(rule, sopt->sopt_valsize); 3893 if (error == 0) { 3894 error = add_rule(&layer3_chain, rule); 3895 size = RULESIZE(rule); 3896 if (!error && sopt->sopt_dir == SOPT_GET) 3897 error = sooptcopyout(sopt, rule, size); 3898 } 3899 free(rule, M_TEMP); 3900 break; 3901 3902 case IP_FW_DEL: 3903 /* 3904 * IP_FW_DEL is used for deleting single rules or sets, 3905 * and (ab)used to atomically manipulate sets. Argument size 3906 * is used to distinguish between the two: 3907 * sizeof(u_int32_t) 3908 * delete single rule or set of rules, 3909 * or reassign rules (or sets) to a different set. 3910 * 2*sizeof(u_int32_t) 3911 * atomic disable/enable sets. 3912 * first u_int32_t contains sets to be disabled, 3913 * second u_int32_t contains sets to be enabled. 3914 */ 3915 error = sooptcopyin(sopt, rulenum, 3916 2*sizeof(u_int32_t), sizeof(u_int32_t)); 3917 if (error) 3918 break; 3919 size = sopt->sopt_valsize; 3920 if (size == sizeof(u_int32_t)) /* delete or reassign */ 3921 error = del_entry(&layer3_chain, rulenum[0]); 3922 else if (size == 2*sizeof(u_int32_t)) /* set enable/disable */ 3923 set_disable = 3924 (set_disable | rulenum[0]) & ~rulenum[1] & 3925 ~(1<<RESVD_SET); /* set RESVD_SET always enabled */ 3926 else 3927 error = EINVAL; 3928 break; 3929 3930 case IP_FW_ZERO: 3931 case IP_FW_RESETLOG: /* argument is an int, the rule number */ 3932 rule_num = 0; 3933 if (sopt->sopt_val != 0) { 3934 error = sooptcopyin(sopt, &rule_num, 3935 sizeof(int), sizeof(int)); 3936 if (error) 3937 break; 3938 } 3939 error = zero_entry(&layer3_chain, rule_num, 3940 sopt->sopt_name == IP_FW_RESETLOG); 3941 break; 3942 3943 case IP_FW_TABLE_ADD: 3944 { 3945 ipfw_table_entry ent; 3946 3947 error = sooptcopyin(sopt, &ent, 3948 sizeof(ent), sizeof(ent)); 3949 if (error) 3950 break; 3951 error = add_table_entry(&layer3_chain, ent.tbl, 3952 ent.addr, ent.masklen, ent.value); 3953 } 3954 break; 3955 3956 case IP_FW_TABLE_DEL: 3957 { 3958 ipfw_table_entry ent; 3959 3960 error = sooptcopyin(sopt, &ent, 3961 sizeof(ent), sizeof(ent)); 3962 if (error) 3963 break; 3964 error = del_table_entry(&layer3_chain, ent.tbl, 3965 ent.addr, ent.masklen); 3966 } 3967 break; 3968 3969 case IP_FW_TABLE_FLUSH: 3970 { 3971 u_int16_t tbl; 3972 3973 error = sooptcopyin(sopt, &tbl, 3974 sizeof(tbl), sizeof(tbl)); 3975 if (error) 3976 break; 3977 IPFW_WLOCK(&layer3_chain); 3978 error = flush_table(&layer3_chain, tbl); 3979 IPFW_WUNLOCK(&layer3_chain); 3980 } 3981 break; 3982 3983 case IP_FW_TABLE_GETSIZE: 3984 { 3985 u_int32_t tbl, cnt; 3986 3987 if ((error = sooptcopyin(sopt, &tbl, sizeof(tbl), 3988 sizeof(tbl)))) 3989 break; 3990 IPFW_RLOCK(&layer3_chain); 3991 if ((error = count_table(&layer3_chain, tbl, &cnt))) 3992 break; 3993 IPFW_RUNLOCK(&layer3_chain); 3994 error = sooptcopyout(sopt, &cnt, sizeof(cnt)); 3995 } 3996 break; 3997 3998 case IP_FW_TABLE_LIST: 3999 { 4000 ipfw_table *tbl; 4001 4002 if (sopt->sopt_valsize < sizeof(*tbl)) { 4003 error = EINVAL; 4004 break; 4005 } 4006 size = sopt->sopt_valsize; 4007 tbl = malloc(size, M_TEMP, M_WAITOK); 4008 if (tbl == NULL) { 4009 error = ENOMEM; 4010 break; 4011 } 4012 error = sooptcopyin(sopt, tbl, size, sizeof(*tbl)); 4013 if (error) { 4014 free(tbl, M_TEMP); 4015 break; 4016 } 4017 tbl->size = (size - sizeof(*tbl)) / 4018 sizeof(ipfw_table_entry); 4019 IPFW_WLOCK(&layer3_chain); 4020 error = dump_table(&layer3_chain, tbl); 4021 if (error) { 4022 IPFW_WUNLOCK(&layer3_chain); 4023 free(tbl, M_TEMP); 4024 break; 4025 } 4026 IPFW_WUNLOCK(&layer3_chain); 4027 error = sooptcopyout(sopt, tbl, size); 4028 free(tbl, M_TEMP); 4029 } 4030 break; 4031 4032 default: 4033 printf("ipfw: ipfw_ctl invalid option %d\n", sopt->sopt_name); 4034 error = EINVAL; 4035 } 4036 4037 return (error); 4038#undef RULE_MAXSIZE 4039} 4040 4041/** 4042 * dummynet needs a reference to the default rule, because rules can be 4043 * deleted while packets hold a reference to them. When this happens, 4044 * dummynet changes the reference to the default rule (it could well be a 4045 * NULL pointer, but this way we do not need to check for the special 4046 * case, plus here he have info on the default behaviour). 4047 */ 4048struct ip_fw *ip_fw_default_rule; 4049 4050/* 4051 * This procedure is only used to handle keepalives. It is invoked 4052 * every dyn_keepalive_period 4053 */ 4054static void 4055ipfw_tick(void * __unused unused) 4056{ 4057 struct mbuf *m0, *m, *mnext, **mtailp; 4058 int i; 4059 ipfw_dyn_rule *q; 4060 4061 if (dyn_keepalive == 0 || ipfw_dyn_v == NULL || dyn_count == 0) 4062 goto done; 4063 4064 /* 4065 * We make a chain of packets to go out here -- not deferring 4066 * until after we drop the IPFW dynamic rule lock would result 4067 * in a lock order reversal with the normal packet input -> ipfw 4068 * call stack. 4069 */ 4070 m0 = NULL; 4071 mtailp = &m0; 4072 IPFW_DYN_LOCK(); 4073 for (i = 0 ; i < curr_dyn_buckets ; i++) { 4074 for (q = ipfw_dyn_v[i] ; q ; q = q->next ) { 4075 if (q->dyn_type == O_LIMIT_PARENT) 4076 continue; 4077 if (q->id.proto != IPPROTO_TCP) 4078 continue; 4079 if ( (q->state & BOTH_SYN) != BOTH_SYN) 4080 continue; 4081 if (TIME_LEQ( time_uptime+dyn_keepalive_interval, 4082 q->expire)) 4083 continue; /* too early */ 4084 if (TIME_LEQ(q->expire, time_uptime)) 4085 continue; /* too late, rule expired */ 4086 4087 *mtailp = send_pkt(&(q->id), q->ack_rev - 1, 4088 q->ack_fwd, TH_SYN); 4089 if (*mtailp != NULL) 4090 mtailp = &(*mtailp)->m_nextpkt; 4091 *mtailp = send_pkt(&(q->id), q->ack_fwd - 1, 4092 q->ack_rev, 0); 4093 if (*mtailp != NULL) 4094 mtailp = &(*mtailp)->m_nextpkt; 4095 } 4096 } 4097 IPFW_DYN_UNLOCK(); 4098 for (m = mnext = m0; m != NULL; m = mnext) { 4099 mnext = m->m_nextpkt; 4100 m->m_nextpkt = NULL; 4101 ip_output(m, NULL, NULL, 0, NULL, NULL); 4102 } 4103done: 4104 callout_reset(&ipfw_timeout, dyn_keepalive_period*hz, ipfw_tick, NULL); 4105} 4106 4107int 4108ipfw_init(void) 4109{ 4110 struct ip_fw default_rule; 4111 int error; 4112 4113#ifdef INET6 4114 /* Setup IPv6 fw sysctl tree. */ 4115 sysctl_ctx_init(&ip6_fw_sysctl_ctx); 4116 ip6_fw_sysctl_tree = SYSCTL_ADD_NODE(&ip6_fw_sysctl_ctx, 4117 SYSCTL_STATIC_CHILDREN(_net_inet6_ip6), OID_AUTO, "fw", 4118 CTLFLAG_RW | CTLFLAG_SECURE, 0, "Firewall"); 4119 SYSCTL_ADD_INT(&ip6_fw_sysctl_ctx, SYSCTL_CHILDREN(ip6_fw_sysctl_tree), 4120 OID_AUTO, "deny_unknown_exthdrs", CTLFLAG_RW | CTLFLAG_SECURE, 4121 &fw_deny_unknown_exthdrs, 0, 4122 "Deny packets with unknown IPv6 Extension Headers"); 4123#endif 4124 4125 layer3_chain.rules = NULL; 4126 IPFW_LOCK_INIT(&layer3_chain); 4127 ipfw_dyn_rule_zone = uma_zcreate("IPFW dynamic rule zone", 4128 sizeof(ipfw_dyn_rule), NULL, NULL, NULL, NULL, 4129 UMA_ALIGN_PTR, 0); 4130 IPFW_DYN_LOCK_INIT(); 4131 callout_init(&ipfw_timeout, NET_CALLOUT_MPSAFE); 4132 4133 bzero(&default_rule, sizeof default_rule); 4134 4135 default_rule.act_ofs = 0; 4136 default_rule.rulenum = IPFW_DEFAULT_RULE; 4137 default_rule.cmd_len = 1; 4138 default_rule.set = RESVD_SET; 4139 4140 default_rule.cmd[0].len = 1; 4141 default_rule.cmd[0].opcode = 4142#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 4143 1 ? O_ACCEPT : 4144#endif 4145 O_DENY; 4146 4147 error = add_rule(&layer3_chain, &default_rule); 4148 if (error != 0) { 4149 printf("ipfw2: error %u initializing default rule " 4150 "(support disabled)\n", error); 4151 IPFW_DYN_LOCK_DESTROY(); 4152 IPFW_LOCK_DESTROY(&layer3_chain); 4153 uma_zdestroy(ipfw_dyn_rule_zone); 4154 return (error); 4155 } 4156 4157 ip_fw_default_rule = layer3_chain.rules; 4158 printf("ipfw2 (+ipv6) initialized, divert %s, " 4159 "rule-based forwarding " 4160#ifdef IPFIREWALL_FORWARD 4161 "enabled, " 4162#else 4163 "disabled, " 4164#endif 4165 "default to %s, logging ", 4166#ifdef IPDIVERT 4167 "enabled", 4168#else 4169 "loadable", 4170#endif 4171 default_rule.cmd[0].opcode == O_ACCEPT ? "accept" : "deny"); 4172 4173#ifdef IPFIREWALL_VERBOSE 4174 fw_verbose = 1; 4175#endif 4176#ifdef IPFIREWALL_VERBOSE_LIMIT 4177 verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 4178#endif 4179 if (fw_verbose == 0) 4180 printf("disabled\n"); 4181 else if (verbose_limit == 0) 4182 printf("unlimited\n"); 4183 else 4184 printf("limited to %d packets/entry by default\n", 4185 verbose_limit); 4186 4187 error = init_tables(&layer3_chain); 4188 if (error) { 4189 IPFW_DYN_LOCK_DESTROY(); 4190 IPFW_LOCK_DESTROY(&layer3_chain); 4191 uma_zdestroy(ipfw_dyn_rule_zone); 4192 return (error); 4193 } 4194 ip_fw_ctl_ptr = ipfw_ctl; 4195 ip_fw_chk_ptr = ipfw_chk; 4196 callout_reset(&ipfw_timeout, hz, ipfw_tick, NULL); 4197 4198 return (0); 4199} 4200 4201void 4202ipfw_destroy(void) 4203{ 4204 struct ip_fw *reap; 4205 4206 ip_fw_chk_ptr = NULL; 4207 ip_fw_ctl_ptr = NULL; 4208 callout_drain(&ipfw_timeout); 4209 IPFW_WLOCK(&layer3_chain); 4210 flush_tables(&layer3_chain); 4211 layer3_chain.reap = NULL; 4212 free_chain(&layer3_chain, 1 /* kill default rule */); 4213 reap = layer3_chain.reap, layer3_chain.reap = NULL; 4214 IPFW_WUNLOCK(&layer3_chain); 4215 if (reap != NULL) 4216 reap_rules(reap); 4217 IPFW_DYN_LOCK_DESTROY(); 4218 uma_zdestroy(ipfw_dyn_rule_zone); 4219 IPFW_LOCK_DESTROY(&layer3_chain); 4220 4221#ifdef INET6 4222 /* Free IPv6 fw sysctl tree. */ 4223 sysctl_ctx_free(&ip6_fw_sysctl_ctx); 4224#endif 4225 4226 printf("IP firewall unloaded\n"); 4227} 4228