ip_fw2.c revision 150122
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 150122 2005-09-14 07:53:54Z bz $ 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#include "opt_inet6.h" 41#include "opt_ipsec.h" 42#ifndef INET 43#error IPFIREWALL requires INET. 44#endif /* INET */ 45#endif 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/jail.h> 54#include <sys/module.h> 55#include <sys/proc.h> 56#include <sys/socket.h> 57#include <sys/socketvar.h> 58#include <sys/sysctl.h> 59#include <sys/syslog.h> 60#include <sys/ucred.h> 61#include <net/if.h> 62#include <net/radix.h> 63#include <net/route.h> 64#include <netinet/in.h> 65#include <netinet/in_systm.h> 66#include <netinet/in_var.h> 67#include <netinet/in_pcb.h> 68#include <netinet/ip.h> 69#include <netinet/ip_var.h> 70#include <netinet/ip_icmp.h> 71#include <netinet/ip_fw.h> 72#include <netinet/ip_divert.h> 73#include <netinet/ip_dummynet.h> 74#include <netinet/tcp.h> 75#include <netinet/tcp_timer.h> 76#include <netinet/tcp_var.h> 77#include <netinet/tcpip.h> 78#include <netinet/udp.h> 79#include <netinet/udp_var.h> 80 81#include <netgraph/ng_ipfw.h> 82 83#include <altq/if_altq.h> 84 85#ifdef IPSEC 86#include <netinet6/ipsec.h> 87#endif 88 89#include <netinet/ip6.h> 90#include <netinet/icmp6.h> 91#ifdef INET6 92#include <netinet6/scope6_var.h> 93#endif 94 95#include <netinet/if_ether.h> /* XXX for ETHERTYPE_IP */ 96 97#include <machine/in_cksum.h> /* XXX for in_cksum */ 98 99/* 100 * set_disable contains one bit per set value (0..31). 101 * If the bit is set, all rules with the corresponding set 102 * are disabled. Set RESVD_SET(31) is reserved for the default rule 103 * and rules that are not deleted by the flush command, 104 * and CANNOT be disabled. 105 * Rules in set RESVD_SET can only be deleted explicitly. 106 */ 107static u_int32_t set_disable; 108 109static int fw_verbose; 110static int verbose_limit; 111 112static struct callout ipfw_timeout; 113static uma_zone_t ipfw_dyn_rule_zone; 114#define IPFW_DEFAULT_RULE 65535 115 116/* 117 * Data structure to cache our ucred related 118 * information. This structure only gets used if 119 * the user specified UID/GID based constraints in 120 * a firewall rule. 121 */ 122struct ip_fw_ugid { 123 gid_t fw_groups[NGROUPS]; 124 int fw_ngroups; 125 uid_t fw_uid; 126 int fw_prid; 127}; 128 129struct ip_fw_chain { 130 struct ip_fw *rules; /* list of rules */ 131 struct ip_fw *reap; /* list of rules to reap */ 132 struct mtx mtx; /* lock guarding rule list */ 133 int busy_count; /* busy count for rw locks */ 134 int want_write; 135 struct cv cv; 136}; 137#define IPFW_LOCK_INIT(_chain) \ 138 mtx_init(&(_chain)->mtx, "IPFW static rules", NULL, \ 139 MTX_DEF | MTX_RECURSE) 140#define IPFW_LOCK_DESTROY(_chain) mtx_destroy(&(_chain)->mtx) 141#define IPFW_WLOCK_ASSERT(_chain) do { \ 142 mtx_assert(&(_chain)->mtx, MA_OWNED); \ 143 NET_ASSERT_GIANT(); \ 144} while (0) 145 146static __inline void 147IPFW_RLOCK(struct ip_fw_chain *chain) 148{ 149 mtx_lock(&chain->mtx); 150 chain->busy_count++; 151 mtx_unlock(&chain->mtx); 152} 153 154static __inline void 155IPFW_RUNLOCK(struct ip_fw_chain *chain) 156{ 157 mtx_lock(&chain->mtx); 158 chain->busy_count--; 159 if (chain->busy_count == 0 && chain->want_write) 160 cv_signal(&chain->cv); 161 mtx_unlock(&chain->mtx); 162} 163 164static __inline void 165IPFW_WLOCK(struct ip_fw_chain *chain) 166{ 167 mtx_lock(&chain->mtx); 168 chain->want_write++; 169 while (chain->busy_count > 0) 170 cv_wait(&chain->cv, &chain->mtx); 171} 172 173static __inline void 174IPFW_WUNLOCK(struct ip_fw_chain *chain) 175{ 176 chain->want_write--; 177 cv_signal(&chain->cv); 178 mtx_unlock(&chain->mtx); 179} 180 181/* 182 * list of rules for layer 3 183 */ 184static struct ip_fw_chain layer3_chain; 185 186MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's"); 187MALLOC_DEFINE(M_IPFW_TBL, "ipfw_tbl", "IpFw tables"); 188 189struct table_entry { 190 struct radix_node rn[2]; 191 struct sockaddr_in addr, mask; 192 u_int32_t value; 193}; 194 195#define IPFW_TABLES_MAX 128 196static struct ip_fw_table { 197 struct radix_node_head *rnh; 198 int modified; 199 in_addr_t last_addr; 200 int last_match; 201 u_int32_t last_value; 202} ipfw_tables[IPFW_TABLES_MAX]; 203 204static int fw_debug = 1; 205static int autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 206 207#ifdef SYSCTL_NODE 208SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 209SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, enable, 210 CTLFLAG_RW | CTLFLAG_SECURE3, 211 &fw_enable, 0, "Enable ipfw"); 212SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, CTLFLAG_RW, 213 &autoinc_step, 0, "Rule number autincrement step"); 214SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 215 CTLFLAG_RW | CTLFLAG_SECURE3, 216 &fw_one_pass, 0, 217 "Only do a single pass through ipfw when using dummynet(4)"); 218SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW, 219 &fw_debug, 0, "Enable printing of debug ip_fw statements"); 220SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, 221 CTLFLAG_RW | CTLFLAG_SECURE3, 222 &fw_verbose, 0, "Log matches to ipfw rules"); 223SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, 224 &verbose_limit, 0, "Set upper limit of matches of ipfw rules logged"); 225 226/* 227 * Description of dynamic rules. 228 * 229 * Dynamic rules are stored in lists accessed through a hash table 230 * (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can 231 * be modified through the sysctl variable dyn_buckets which is 232 * updated when the table becomes empty. 233 * 234 * XXX currently there is only one list, ipfw_dyn. 235 * 236 * When a packet is received, its address fields are first masked 237 * with the mask defined for the rule, then hashed, then matched 238 * against the entries in the corresponding list. 239 * Dynamic rules can be used for different purposes: 240 * + stateful rules; 241 * + enforcing limits on the number of sessions; 242 * + in-kernel NAT (not implemented yet) 243 * 244 * The lifetime of dynamic rules is regulated by dyn_*_lifetime, 245 * measured in seconds and depending on the flags. 246 * 247 * The total number of dynamic rules is stored in dyn_count. 248 * The max number of dynamic rules is dyn_max. When we reach 249 * the maximum number of rules we do not create anymore. This is 250 * done to avoid consuming too much memory, but also too much 251 * time when searching on each packet (ideally, we should try instead 252 * to put a limit on the length of the list on each bucket...). 253 * 254 * Each dynamic rule holds a pointer to the parent ipfw rule so 255 * we know what action to perform. Dynamic rules are removed when 256 * the parent rule is deleted. XXX we should make them survive. 257 * 258 * There are some limitations with dynamic rules -- we do not 259 * obey the 'randomized match', and we do not do multiple 260 * passes through the firewall. XXX check the latter!!! 261 */ 262static ipfw_dyn_rule **ipfw_dyn_v = NULL; 263static u_int32_t dyn_buckets = 256; /* must be power of 2 */ 264static u_int32_t curr_dyn_buckets = 256; /* must be power of 2 */ 265 266static struct mtx ipfw_dyn_mtx; /* mutex guarding dynamic rules */ 267#define IPFW_DYN_LOCK_INIT() \ 268 mtx_init(&ipfw_dyn_mtx, "IPFW dynamic rules", NULL, MTX_DEF) 269#define IPFW_DYN_LOCK_DESTROY() mtx_destroy(&ipfw_dyn_mtx) 270#define IPFW_DYN_LOCK() mtx_lock(&ipfw_dyn_mtx) 271#define IPFW_DYN_UNLOCK() mtx_unlock(&ipfw_dyn_mtx) 272#define IPFW_DYN_LOCK_ASSERT() mtx_assert(&ipfw_dyn_mtx, MA_OWNED) 273 274/* 275 * Timeouts for various events in handing dynamic rules. 276 */ 277static u_int32_t dyn_ack_lifetime = 300; 278static u_int32_t dyn_syn_lifetime = 20; 279static u_int32_t dyn_fin_lifetime = 1; 280static u_int32_t dyn_rst_lifetime = 1; 281static u_int32_t dyn_udp_lifetime = 10; 282static u_int32_t dyn_short_lifetime = 5; 283 284/* 285 * Keepalives are sent if dyn_keepalive is set. They are sent every 286 * dyn_keepalive_period seconds, in the last dyn_keepalive_interval 287 * seconds of lifetime of a rule. 288 * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower 289 * than dyn_keepalive_period. 290 */ 291 292static u_int32_t dyn_keepalive_interval = 20; 293static u_int32_t dyn_keepalive_period = 5; 294static u_int32_t dyn_keepalive = 1; /* do send keepalives */ 295 296static u_int32_t static_count; /* # of static rules */ 297static u_int32_t static_len; /* size in bytes of static rules */ 298static u_int32_t dyn_count; /* # of dynamic rules */ 299static u_int32_t dyn_max = 4096; /* max # of dynamic rules */ 300 301SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLFLAG_RW, 302 &dyn_buckets, 0, "Number of dyn. buckets"); 303SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_RD, 304 &curr_dyn_buckets, 0, "Current Number of dyn. buckets"); 305SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_RD, 306 &dyn_count, 0, "Number of dyn. rules"); 307SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_RW, 308 &dyn_max, 0, "Max number of dyn. rules"); 309SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, CTLFLAG_RD, 310 &static_count, 0, "Number of static rules"); 311SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_RW, 312 &dyn_ack_lifetime, 0, "Lifetime of dyn. rules for acks"); 313SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_RW, 314 &dyn_syn_lifetime, 0, "Lifetime of dyn. rules for syn"); 315SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, CTLFLAG_RW, 316 &dyn_fin_lifetime, 0, "Lifetime of dyn. rules for fin"); 317SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, CTLFLAG_RW, 318 &dyn_rst_lifetime, 0, "Lifetime of dyn. rules for rst"); 319SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime, CTLFLAG_RW, 320 &dyn_udp_lifetime, 0, "Lifetime of dyn. rules for UDP"); 321SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_RW, 322 &dyn_short_lifetime, 0, "Lifetime of dyn. rules for other situations"); 323SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_keepalive, CTLFLAG_RW, 324 &dyn_keepalive, 0, "Enable keepalives for dyn. rules"); 325 326#ifdef INET6 327/* 328 * IPv6 specific variables 329 */ 330SYSCTL_DECL(_net_inet6_ip6); 331 332static struct sysctl_ctx_list ip6_fw_sysctl_ctx; 333static struct sysctl_oid *ip6_fw_sysctl_tree; 334#endif /* INET6 */ 335#endif /* SYSCTL_NODE */ 336 337static int fw_deny_unknown_exthdrs = 1; 338 339 340/* 341 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 342 * Other macros just cast void * into the appropriate type 343 */ 344#define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 345#define TCP(p) ((struct tcphdr *)(p)) 346#define UDP(p) ((struct udphdr *)(p)) 347#define ICMP(p) ((struct icmphdr *)(p)) 348#define ICMP6(p) ((struct icmp6_hdr *)(p)) 349 350static __inline int 351icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 352{ 353 int type = icmp->icmp_type; 354 355 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 356} 357 358#define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 359 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 360 361static int 362is_icmp_query(struct icmphdr *icmp) 363{ 364 int type = icmp->icmp_type; 365 366 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 367} 368#undef TT 369 370/* 371 * The following checks use two arrays of 8 or 16 bits to store the 372 * bits that we want set or clear, respectively. They are in the 373 * low and high half of cmd->arg1 or cmd->d[0]. 374 * 375 * We scan options and store the bits we find set. We succeed if 376 * 377 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 378 * 379 * The code is sometimes optimized not to store additional variables. 380 */ 381 382static int 383flags_match(ipfw_insn *cmd, u_int8_t bits) 384{ 385 u_char want_clear; 386 bits = ~bits; 387 388 if ( ((cmd->arg1 & 0xff) & bits) != 0) 389 return 0; /* some bits we want set were clear */ 390 want_clear = (cmd->arg1 >> 8) & 0xff; 391 if ( (want_clear & bits) != want_clear) 392 return 0; /* some bits we want clear were set */ 393 return 1; 394} 395 396static int 397ipopts_match(struct ip *ip, ipfw_insn *cmd) 398{ 399 int optlen, bits = 0; 400 u_char *cp = (u_char *)(ip + 1); 401 int x = (ip->ip_hl << 2) - sizeof (struct ip); 402 403 for (; x > 0; x -= optlen, cp += optlen) { 404 int opt = cp[IPOPT_OPTVAL]; 405 406 if (opt == IPOPT_EOL) 407 break; 408 if (opt == IPOPT_NOP) 409 optlen = 1; 410 else { 411 optlen = cp[IPOPT_OLEN]; 412 if (optlen <= 0 || optlen > x) 413 return 0; /* invalid or truncated */ 414 } 415 switch (opt) { 416 417 default: 418 break; 419 420 case IPOPT_LSRR: 421 bits |= IP_FW_IPOPT_LSRR; 422 break; 423 424 case IPOPT_SSRR: 425 bits |= IP_FW_IPOPT_SSRR; 426 break; 427 428 case IPOPT_RR: 429 bits |= IP_FW_IPOPT_RR; 430 break; 431 432 case IPOPT_TS: 433 bits |= IP_FW_IPOPT_TS; 434 break; 435 } 436 } 437 return (flags_match(cmd, bits)); 438} 439 440static int 441tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 442{ 443 int optlen, bits = 0; 444 u_char *cp = (u_char *)(tcp + 1); 445 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 446 447 for (; x > 0; x -= optlen, cp += optlen) { 448 int opt = cp[0]; 449 if (opt == TCPOPT_EOL) 450 break; 451 if (opt == TCPOPT_NOP) 452 optlen = 1; 453 else { 454 optlen = cp[1]; 455 if (optlen <= 0) 456 break; 457 } 458 459 switch (opt) { 460 461 default: 462 break; 463 464 case TCPOPT_MAXSEG: 465 bits |= IP_FW_TCPOPT_MSS; 466 break; 467 468 case TCPOPT_WINDOW: 469 bits |= IP_FW_TCPOPT_WINDOW; 470 break; 471 472 case TCPOPT_SACK_PERMITTED: 473 case TCPOPT_SACK: 474 bits |= IP_FW_TCPOPT_SACK; 475 break; 476 477 case TCPOPT_TIMESTAMP: 478 bits |= IP_FW_TCPOPT_TS; 479 break; 480 481 } 482 } 483 return (flags_match(cmd, bits)); 484} 485 486static int 487iface_match(struct ifnet *ifp, ipfw_insn_if *cmd) 488{ 489 if (ifp == NULL) /* no iface with this packet, match fails */ 490 return 0; 491 /* Check by name or by IP address */ 492 if (cmd->name[0] != '\0') { /* match by name */ 493 /* Check name */ 494 if (cmd->p.glob) { 495 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 496 return(1); 497 } else { 498 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 499 return(1); 500 } 501 } else { 502 struct ifaddr *ia; 503 504 /* XXX lock? */ 505 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 506 if (ia->ifa_addr == NULL) 507 continue; 508 if (ia->ifa_addr->sa_family != AF_INET) 509 continue; 510 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 511 (ia->ifa_addr))->sin_addr.s_addr) 512 return(1); /* match */ 513 } 514 } 515 return(0); /* no match, fail ... */ 516} 517 518/* 519 * The verify_path function checks if a route to the src exists and 520 * if it is reachable via ifp (when provided). 521 * 522 * The 'verrevpath' option checks that the interface that an IP packet 523 * arrives on is the same interface that traffic destined for the 524 * packet's source address would be routed out of. The 'versrcreach' 525 * option just checks that the source address is reachable via any route 526 * (except default) in the routing table. These two are a measure to block 527 * forged packets. This is also commonly known as "anti-spoofing" or Unicast 528 * Reverse Path Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 529 * is purposely reminiscent of the Cisco IOS command, 530 * 531 * ip verify unicast reverse-path 532 * ip verify unicast source reachable-via any 533 * 534 * which implements the same functionality. But note that syntax is 535 * misleading. The check may be performed on all IP packets whether unicast, 536 * multicast, or broadcast. 537 */ 538static int 539verify_path(struct in_addr src, struct ifnet *ifp) 540{ 541 struct route ro; 542 struct sockaddr_in *dst; 543 544 bzero(&ro, sizeof(ro)); 545 546 dst = (struct sockaddr_in *)&(ro.ro_dst); 547 dst->sin_family = AF_INET; 548 dst->sin_len = sizeof(*dst); 549 dst->sin_addr = src; 550 rtalloc_ign(&ro, RTF_CLONING); 551 552 if (ro.ro_rt == NULL) 553 return 0; 554 555 /* if ifp is provided, check for equality with rtentry */ 556 if (ifp != NULL && ro.ro_rt->rt_ifp != ifp) { 557 RTFREE(ro.ro_rt); 558 return 0; 559 } 560 561 /* if no ifp provided, check if rtentry is not default route */ 562 if (ifp == NULL && 563 satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) { 564 RTFREE(ro.ro_rt); 565 return 0; 566 } 567 568 /* or if this is a blackhole/reject route */ 569 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 570 RTFREE(ro.ro_rt); 571 return 0; 572 } 573 574 /* found valid route */ 575 RTFREE(ro.ro_rt); 576 return 1; 577} 578 579#ifdef INET6 580/* 581 * ipv6 specific rules here... 582 */ 583static __inline int 584icmp6type_match (int type, ipfw_insn_u32 *cmd) 585{ 586 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 587} 588 589static int 590flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 591{ 592 int i; 593 for (i=0; i <= cmd->o.arg1; ++i ) 594 if (curr_flow == cmd->d[i] ) 595 return 1; 596 return 0; 597} 598 599/* support for IP6_*_ME opcodes */ 600static int 601search_ip6_addr_net (struct in6_addr * ip6_addr) 602{ 603 struct ifnet *mdc; 604 struct ifaddr *mdc2; 605 struct in6_ifaddr *fdm; 606 struct in6_addr copia; 607 608 TAILQ_FOREACH(mdc, &ifnet, if_link) 609 for (mdc2 = mdc->if_addrlist.tqh_first; mdc2; 610 mdc2 = mdc2->ifa_list.tqe_next) { 611 if (!mdc2->ifa_addr) 612 continue; 613 if (mdc2->ifa_addr->sa_family == AF_INET6) { 614 fdm = (struct in6_ifaddr *)mdc2; 615 copia = fdm->ia_addr.sin6_addr; 616 /* need for leaving scope_id in the sock_addr */ 617 in6_clearscope(&copia); 618 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) 619 return 1; 620 } 621 } 622 return 0; 623} 624 625static int 626verify_path6(struct in6_addr *src, struct ifnet *ifp) 627{ 628 struct route_in6 ro; 629 struct sockaddr_in6 *dst; 630 631 bzero(&ro, sizeof(ro)); 632 633 dst = (struct sockaddr_in6 * )&(ro.ro_dst); 634 dst->sin6_family = AF_INET6; 635 dst->sin6_len = sizeof(*dst); 636 dst->sin6_addr = *src; 637 rtalloc_ign((struct route *)&ro, RTF_CLONING); 638 639 if (ro.ro_rt == NULL) 640 return 0; 641 642 /* if ifp is provided, check for equality with rtentry */ 643 if (ifp != NULL && ro.ro_rt->rt_ifp != ifp) { 644 RTFREE(ro.ro_rt); 645 return 0; 646 } 647 648 /* if no ifp provided, check if rtentry is not default route */ 649 if (ifp == NULL && 650 IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) { 651 RTFREE(ro.ro_rt); 652 return 0; 653 } 654 655 /* or if this is a blackhole/reject route */ 656 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 657 RTFREE(ro.ro_rt); 658 return 0; 659 } 660 661 /* found valid route */ 662 RTFREE(ro.ro_rt); 663 return 1; 664 665} 666static __inline int 667hash_packet6(struct ipfw_flow_id *id) 668{ 669 u_int32_t i; 670 i = (id->dst_ip6.__u6_addr.__u6_addr32[0]) ^ 671 (id->dst_ip6.__u6_addr.__u6_addr32[1]) ^ 672 (id->dst_ip6.__u6_addr.__u6_addr32[2]) ^ 673 (id->dst_ip6.__u6_addr.__u6_addr32[3]) ^ 674 (id->dst_port) ^ (id->src_port) ^ (id->flow_id6); 675 return i; 676} 677 678static int 679is_icmp6_query(int icmp6_type) 680{ 681 if ((icmp6_type <= ICMP6_MAXTYPE) && 682 (icmp6_type == ICMP6_ECHO_REQUEST || 683 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 684 icmp6_type == ICMP6_WRUREQUEST || 685 icmp6_type == ICMP6_FQDN_QUERY || 686 icmp6_type == ICMP6_NI_QUERY)) 687 return (1); 688 689 return (0); 690} 691 692static void 693send_reject6(struct ip_fw_args *args, int code, u_short offset, u_int hlen) 694{ 695 if (code == ICMP6_UNREACH_RST && offset == 0 && 696 args->f_id.proto == IPPROTO_TCP) { 697 struct ip6_hdr *ip6; 698 struct tcphdr *tcp; 699 tcp_seq ack, seq; 700 int flags; 701 struct { 702 struct ip6_hdr ip6; 703 struct tcphdr th; 704 } ti; 705 706 if (args->m->m_len < (hlen+sizeof(struct tcphdr))) { 707 args->m = m_pullup(args->m, hlen+sizeof(struct tcphdr)); 708 if (args->m == NULL) 709 return; 710 } 711 712 ip6 = mtod(args->m, struct ip6_hdr *); 713 tcp = (struct tcphdr *)(mtod(args->m, char *) + hlen); 714 715 if ((tcp->th_flags & TH_RST) != 0) { 716 m_freem(args->m); 717 return; 718 } 719 720 ti.ip6 = *ip6; 721 ti.th = *tcp; 722 ti.th.th_seq = ntohl(ti.th.th_seq); 723 ti.th.th_ack = ntohl(ti.th.th_ack); 724 ti.ip6.ip6_nxt = IPPROTO_TCP; 725 726 if (ti.th.th_flags & TH_ACK) { 727 ack = 0; 728 seq = ti.th.th_ack; 729 flags = TH_RST; 730 } else { 731 ack = ti.th.th_seq; 732 if (((args->m)->m_flags & M_PKTHDR) != 0) { 733 ack += (args->m)->m_pkthdr.len - hlen 734 - (ti.th.th_off << 2); 735 } else if (ip6->ip6_plen) { 736 ack += ntohs(ip6->ip6_plen) + sizeof(*ip6) 737 - hlen - (ti.th.th_off << 2); 738 } else { 739 m_freem(args->m); 740 return; 741 } 742 if (tcp->th_flags & TH_SYN) 743 ack++; 744 seq = 0; 745 flags = TH_RST|TH_ACK; 746 } 747 bcopy(&ti, ip6, sizeof(ti)); 748 tcp_respond(NULL, ip6, (struct tcphdr *)(ip6 + 1), 749 args->m, ack, seq, flags); 750 751 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */ 752 icmp6_error(args->m, ICMP6_DST_UNREACH, code, 0); 753 754 } else 755 m_freem(args->m); 756 757 args->m = NULL; 758} 759 760#endif /* INET6 */ 761 762static u_int64_t norule_counter; /* counter for ipfw_log(NULL...) */ 763 764#define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0 765#define SNP(buf) buf, sizeof(buf) 766 767/* 768 * We enter here when we have a rule with O_LOG. 769 * XXX this function alone takes about 2Kbytes of code! 770 */ 771static void 772ipfw_log(struct ip_fw *f, u_int hlen, struct ip_fw_args *args, 773 struct mbuf *m, struct ifnet *oif, u_short offset) 774{ 775 struct ether_header *eh = args->eh; 776 char *action; 777 int limit_reached = 0; 778 char action2[40], proto[128], fragment[32]; 779 780 fragment[0] = '\0'; 781 proto[0] = '\0'; 782 783 if (f == NULL) { /* bogus pkt */ 784 if (verbose_limit != 0 && norule_counter >= verbose_limit) 785 return; 786 norule_counter++; 787 if (norule_counter == verbose_limit) 788 limit_reached = verbose_limit; 789 action = "Refuse"; 790 } else { /* O_LOG is the first action, find the real one */ 791 ipfw_insn *cmd = ACTION_PTR(f); 792 ipfw_insn_log *l = (ipfw_insn_log *)cmd; 793 794 if (l->max_log != 0 && l->log_left == 0) 795 return; 796 l->log_left--; 797 if (l->log_left == 0) 798 limit_reached = l->max_log; 799 cmd += F_LEN(cmd); /* point to first action */ 800 if (cmd->opcode == O_ALTQ) { 801 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 802 803 snprintf(SNPARGS(action2, 0), "Altq %d", 804 altq->qid); 805 cmd += F_LEN(cmd); 806 } 807 if (cmd->opcode == O_PROB) 808 cmd += F_LEN(cmd); 809 810 action = action2; 811 switch (cmd->opcode) { 812 case O_DENY: 813 action = "Deny"; 814 break; 815 816 case O_REJECT: 817 if (cmd->arg1==ICMP_REJECT_RST) 818 action = "Reset"; 819 else if (cmd->arg1==ICMP_UNREACH_HOST) 820 action = "Reject"; 821 else 822 snprintf(SNPARGS(action2, 0), "Unreach %d", 823 cmd->arg1); 824 break; 825 826 case O_UNREACH6: 827 if (cmd->arg1==ICMP6_UNREACH_RST) 828 action = "Reset"; 829 else 830 snprintf(SNPARGS(action2, 0), "Unreach %d", 831 cmd->arg1); 832 break; 833 834 case O_ACCEPT: 835 action = "Accept"; 836 break; 837 case O_COUNT: 838 action = "Count"; 839 break; 840 case O_DIVERT: 841 snprintf(SNPARGS(action2, 0), "Divert %d", 842 cmd->arg1); 843 break; 844 case O_TEE: 845 snprintf(SNPARGS(action2, 0), "Tee %d", 846 cmd->arg1); 847 break; 848 case O_SKIPTO: 849 snprintf(SNPARGS(action2, 0), "SkipTo %d", 850 cmd->arg1); 851 break; 852 case O_PIPE: 853 snprintf(SNPARGS(action2, 0), "Pipe %d", 854 cmd->arg1); 855 break; 856 case O_QUEUE: 857 snprintf(SNPARGS(action2, 0), "Queue %d", 858 cmd->arg1); 859 break; 860 case O_FORWARD_IP: { 861 ipfw_insn_sa *sa = (ipfw_insn_sa *)cmd; 862 int len; 863 864 len = snprintf(SNPARGS(action2, 0), "Forward to %s", 865 inet_ntoa(sa->sa.sin_addr)); 866 if (sa->sa.sin_port) 867 snprintf(SNPARGS(action2, len), ":%d", 868 sa->sa.sin_port); 869 } 870 break; 871 case O_NETGRAPH: 872 snprintf(SNPARGS(action2, 0), "Netgraph %d", 873 cmd->arg1); 874 break; 875 case O_NGTEE: 876 snprintf(SNPARGS(action2, 0), "Ngtee %d", 877 cmd->arg1); 878 break; 879 default: 880 action = "UNKNOWN"; 881 break; 882 } 883 } 884 885 if (hlen == 0) { /* non-ip */ 886 snprintf(SNPARGS(proto, 0), "MAC"); 887 888 } else { 889 int len; 890 char src[48], dst[48]; 891 struct icmphdr *icmp; 892 struct tcphdr *tcp; 893 struct udphdr *udp; 894 /* Initialize to make compiler happy. */ 895 struct ip *ip = NULL; 896#ifdef INET6 897 struct ip6_hdr *ip6 = NULL; 898 struct icmp6_hdr *icmp6; 899#endif 900 src[0] = '\0'; 901 dst[0] = '\0'; 902#ifdef INET6 903 if (args->f_id.addr_type == 6) { 904 snprintf(src, sizeof(src), "[%s]", 905 ip6_sprintf(&args->f_id.src_ip6)); 906 snprintf(dst, sizeof(dst), "[%s]", 907 ip6_sprintf(&args->f_id.dst_ip6)); 908 909 ip6 = (struct ip6_hdr *)mtod(m, struct ip6_hdr *); 910 tcp = (struct tcphdr *)(mtod(args->m, char *) + hlen); 911 udp = (struct udphdr *)(mtod(args->m, char *) + hlen); 912 } else 913#endif 914 { 915 ip = mtod(m, struct ip *); 916 tcp = L3HDR(struct tcphdr, ip); 917 udp = L3HDR(struct udphdr, ip); 918 919 inet_ntoa_r(ip->ip_src, src); 920 inet_ntoa_r(ip->ip_dst, dst); 921 } 922 923 switch (args->f_id.proto) { 924 case IPPROTO_TCP: 925 len = snprintf(SNPARGS(proto, 0), "TCP %s", src); 926 if (offset == 0) 927 snprintf(SNPARGS(proto, len), ":%d %s:%d", 928 ntohs(tcp->th_sport), 929 dst, 930 ntohs(tcp->th_dport)); 931 else 932 snprintf(SNPARGS(proto, len), " %s", dst); 933 break; 934 935 case IPPROTO_UDP: 936 len = snprintf(SNPARGS(proto, 0), "UDP %s", src); 937 if (offset == 0) 938 snprintf(SNPARGS(proto, len), ":%d %s:%d", 939 ntohs(udp->uh_sport), 940 dst, 941 ntohs(udp->uh_dport)); 942 else 943 snprintf(SNPARGS(proto, len), " %s", dst); 944 break; 945 946 case IPPROTO_ICMP: 947 icmp = L3HDR(struct icmphdr, ip); 948 if (offset == 0) 949 len = snprintf(SNPARGS(proto, 0), 950 "ICMP:%u.%u ", 951 icmp->icmp_type, icmp->icmp_code); 952 else 953 len = snprintf(SNPARGS(proto, 0), "ICMP "); 954 len += snprintf(SNPARGS(proto, len), "%s", src); 955 snprintf(SNPARGS(proto, len), " %s", dst); 956 break; 957#ifdef INET6 958 case IPPROTO_ICMPV6: 959 icmp6 = (struct icmp6_hdr *)(mtod(args->m, char *) + hlen); 960 if (offset == 0) 961 len = snprintf(SNPARGS(proto, 0), 962 "ICMPv6:%u.%u ", 963 icmp6->icmp6_type, icmp6->icmp6_code); 964 else 965 len = snprintf(SNPARGS(proto, 0), "ICMPv6 "); 966 len += snprintf(SNPARGS(proto, len), "%s", src); 967 snprintf(SNPARGS(proto, len), " %s", dst); 968 break; 969#endif 970 default: 971 len = snprintf(SNPARGS(proto, 0), "P:%d %s", 972 args->f_id.proto, src); 973 snprintf(SNPARGS(proto, len), " %s", dst); 974 break; 975 } 976 977#ifdef INET6 978 if (args->f_id.addr_type == 6) { 979 if (offset & (IP6F_OFF_MASK | IP6F_MORE_FRAG)) 980 snprintf(SNPARGS(fragment, 0), 981 " (frag %08x:%d@%d%s)", 982 args->f_id.frag_id6, 983 ntohs(ip6->ip6_plen) - hlen, 984 ntohs(offset & IP6F_OFF_MASK) << 3, 985 (offset & IP6F_MORE_FRAG) ? "+" : ""); 986 } else 987#endif 988 { 989 int ip_off, ip_len; 990 if (eh != NULL) { /* layer 2 packets are as on the wire */ 991 ip_off = ntohs(ip->ip_off); 992 ip_len = ntohs(ip->ip_len); 993 } else { 994 ip_off = ip->ip_off; 995 ip_len = ip->ip_len; 996 } 997 if (ip_off & (IP_MF | IP_OFFMASK)) 998 snprintf(SNPARGS(fragment, 0), 999 " (frag %d:%d@%d%s)", 1000 ntohs(ip->ip_id), ip_len - (ip->ip_hl << 2), 1001 offset << 3, 1002 (ip_off & IP_MF) ? "+" : ""); 1003 } 1004 } 1005 if (oif || m->m_pkthdr.rcvif) 1006 log(LOG_SECURITY | LOG_INFO, 1007 "ipfw: %d %s %s %s via %s%s\n", 1008 f ? f->rulenum : -1, 1009 action, proto, oif ? "out" : "in", 1010 oif ? oif->if_xname : m->m_pkthdr.rcvif->if_xname, 1011 fragment); 1012 else 1013 log(LOG_SECURITY | LOG_INFO, 1014 "ipfw: %d %s %s [no if info]%s\n", 1015 f ? f->rulenum : -1, 1016 action, proto, fragment); 1017 if (limit_reached) 1018 log(LOG_SECURITY | LOG_NOTICE, 1019 "ipfw: limit %d reached on entry %d\n", 1020 limit_reached, f ? f->rulenum : -1); 1021} 1022 1023/* 1024 * IMPORTANT: the hash function for dynamic rules must be commutative 1025 * in source and destination (ip,port), because rules are bidirectional 1026 * and we want to find both in the same bucket. 1027 */ 1028static __inline int 1029hash_packet(struct ipfw_flow_id *id) 1030{ 1031 u_int32_t i; 1032 1033#ifdef INET6 1034 if (IS_IP6_FLOW_ID(id)) 1035 i = hash_packet6(id); 1036 else 1037#endif /* INET6 */ 1038 i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port); 1039 i &= (curr_dyn_buckets - 1); 1040 return i; 1041} 1042 1043/** 1044 * unlink a dynamic rule from a chain. prev is a pointer to 1045 * the previous one, q is a pointer to the rule to delete, 1046 * head is a pointer to the head of the queue. 1047 * Modifies q and potentially also head. 1048 */ 1049#define UNLINK_DYN_RULE(prev, head, q) { \ 1050 ipfw_dyn_rule *old_q = q; \ 1051 \ 1052 /* remove a refcount to the parent */ \ 1053 if (q->dyn_type == O_LIMIT) \ 1054 q->parent->count--; \ 1055 DEB(printf("ipfw: unlink entry 0x%08x %d -> 0x%08x %d, %d left\n",\ 1056 (q->id.src_ip), (q->id.src_port), \ 1057 (q->id.dst_ip), (q->id.dst_port), dyn_count-1 ); ) \ 1058 if (prev != NULL) \ 1059 prev->next = q = q->next; \ 1060 else \ 1061 head = q = q->next; \ 1062 dyn_count--; \ 1063 uma_zfree(ipfw_dyn_rule_zone, old_q); } 1064 1065#define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0) 1066 1067/** 1068 * Remove dynamic rules pointing to "rule", or all of them if rule == NULL. 1069 * 1070 * If keep_me == NULL, rules are deleted even if not expired, 1071 * otherwise only expired rules are removed. 1072 * 1073 * The value of the second parameter is also used to point to identify 1074 * a rule we absolutely do not want to remove (e.g. because we are 1075 * holding a reference to it -- this is the case with O_LIMIT_PARENT 1076 * rules). The pointer is only used for comparison, so any non-null 1077 * value will do. 1078 */ 1079static void 1080remove_dyn_rule(struct ip_fw *rule, ipfw_dyn_rule *keep_me) 1081{ 1082 static u_int32_t last_remove = 0; 1083 1084#define FORCE (keep_me == NULL) 1085 1086 ipfw_dyn_rule *prev, *q; 1087 int i, pass = 0, max_pass = 0; 1088 1089 IPFW_DYN_LOCK_ASSERT(); 1090 1091 if (ipfw_dyn_v == NULL || dyn_count == 0) 1092 return; 1093 /* do not expire more than once per second, it is useless */ 1094 if (!FORCE && last_remove == time_second) 1095 return; 1096 last_remove = time_second; 1097 1098 /* 1099 * because O_LIMIT refer to parent rules, during the first pass only 1100 * remove child and mark any pending LIMIT_PARENT, and remove 1101 * them in a second pass. 1102 */ 1103next_pass: 1104 for (i = 0 ; i < curr_dyn_buckets ; i++) { 1105 for (prev=NULL, q = ipfw_dyn_v[i] ; q ; ) { 1106 /* 1107 * Logic can become complex here, so we split tests. 1108 */ 1109 if (q == keep_me) 1110 goto next; 1111 if (rule != NULL && rule != q->rule) 1112 goto next; /* not the one we are looking for */ 1113 if (q->dyn_type == O_LIMIT_PARENT) { 1114 /* 1115 * handle parent in the second pass, 1116 * record we need one. 1117 */ 1118 max_pass = 1; 1119 if (pass == 0) 1120 goto next; 1121 if (FORCE && q->count != 0 ) { 1122 /* XXX should not happen! */ 1123 printf("ipfw: OUCH! cannot remove rule," 1124 " count %d\n", q->count); 1125 } 1126 } else { 1127 if (!FORCE && 1128 !TIME_LEQ( q->expire, time_second )) 1129 goto next; 1130 } 1131 if (q->dyn_type != O_LIMIT_PARENT || !q->count) { 1132 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q); 1133 continue; 1134 } 1135next: 1136 prev=q; 1137 q=q->next; 1138 } 1139 } 1140 if (pass++ < max_pass) 1141 goto next_pass; 1142} 1143 1144 1145/** 1146 * lookup a dynamic rule. 1147 */ 1148static ipfw_dyn_rule * 1149lookup_dyn_rule_locked(struct ipfw_flow_id *pkt, int *match_direction, 1150 struct tcphdr *tcp) 1151{ 1152 /* 1153 * stateful ipfw extensions. 1154 * Lookup into dynamic session queue 1155 */ 1156#define MATCH_REVERSE 0 1157#define MATCH_FORWARD 1 1158#define MATCH_NONE 2 1159#define MATCH_UNKNOWN 3 1160 int i, dir = MATCH_NONE; 1161 ipfw_dyn_rule *prev, *q=NULL; 1162 1163 IPFW_DYN_LOCK_ASSERT(); 1164 1165 if (ipfw_dyn_v == NULL) 1166 goto done; /* not found */ 1167 i = hash_packet( pkt ); 1168 for (prev=NULL, q = ipfw_dyn_v[i] ; q != NULL ; ) { 1169 if (q->dyn_type == O_LIMIT_PARENT && q->count) 1170 goto next; 1171 if (TIME_LEQ( q->expire, time_second)) { /* expire entry */ 1172 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q); 1173 continue; 1174 } 1175 if (pkt->proto == q->id.proto && 1176 q->dyn_type != O_LIMIT_PARENT) { 1177 if (IS_IP6_FLOW_ID(pkt)) { 1178 if (IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1179 &(q->id.src_ip6)) && 1180 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1181 &(q->id.dst_ip6)) && 1182 pkt->src_port == q->id.src_port && 1183 pkt->dst_port == q->id.dst_port ) { 1184 dir = MATCH_FORWARD; 1185 break; 1186 } 1187 if (IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1188 &(q->id.dst_ip6)) && 1189 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1190 &(q->id.src_ip6)) && 1191 pkt->src_port == q->id.dst_port && 1192 pkt->dst_port == q->id.src_port ) { 1193 dir = MATCH_REVERSE; 1194 break; 1195 } 1196 } else { 1197 if (pkt->src_ip == q->id.src_ip && 1198 pkt->dst_ip == q->id.dst_ip && 1199 pkt->src_port == q->id.src_port && 1200 pkt->dst_port == q->id.dst_port ) { 1201 dir = MATCH_FORWARD; 1202 break; 1203 } 1204 if (pkt->src_ip == q->id.dst_ip && 1205 pkt->dst_ip == q->id.src_ip && 1206 pkt->src_port == q->id.dst_port && 1207 pkt->dst_port == q->id.src_port ) { 1208 dir = MATCH_REVERSE; 1209 break; 1210 } 1211 } 1212 } 1213next: 1214 prev = q; 1215 q = q->next; 1216 } 1217 if (q == NULL) 1218 goto done; /* q = NULL, not found */ 1219 1220 if ( prev != NULL) { /* found and not in front */ 1221 prev->next = q->next; 1222 q->next = ipfw_dyn_v[i]; 1223 ipfw_dyn_v[i] = q; 1224 } 1225 if (pkt->proto == IPPROTO_TCP) { /* update state according to flags */ 1226 u_char flags = pkt->flags & (TH_FIN|TH_SYN|TH_RST); 1227 1228#define BOTH_SYN (TH_SYN | (TH_SYN << 8)) 1229#define BOTH_FIN (TH_FIN | (TH_FIN << 8)) 1230 q->state |= (dir == MATCH_FORWARD ) ? flags : (flags << 8); 1231 switch (q->state) { 1232 case TH_SYN: /* opening */ 1233 q->expire = time_second + dyn_syn_lifetime; 1234 break; 1235 1236 case BOTH_SYN: /* move to established */ 1237 case BOTH_SYN | TH_FIN : /* one side tries to close */ 1238 case BOTH_SYN | (TH_FIN << 8) : 1239 if (tcp) { 1240#define _SEQ_GE(a,b) ((int)(a) - (int)(b) >= 0) 1241 u_int32_t ack = ntohl(tcp->th_ack); 1242 if (dir == MATCH_FORWARD) { 1243 if (q->ack_fwd == 0 || _SEQ_GE(ack, q->ack_fwd)) 1244 q->ack_fwd = ack; 1245 else { /* ignore out-of-sequence */ 1246 break; 1247 } 1248 } else { 1249 if (q->ack_rev == 0 || _SEQ_GE(ack, q->ack_rev)) 1250 q->ack_rev = ack; 1251 else { /* ignore out-of-sequence */ 1252 break; 1253 } 1254 } 1255 } 1256 q->expire = time_second + dyn_ack_lifetime; 1257 break; 1258 1259 case BOTH_SYN | BOTH_FIN: /* both sides closed */ 1260 if (dyn_fin_lifetime >= dyn_keepalive_period) 1261 dyn_fin_lifetime = dyn_keepalive_period - 1; 1262 q->expire = time_second + dyn_fin_lifetime; 1263 break; 1264 1265 default: 1266#if 0 1267 /* 1268 * reset or some invalid combination, but can also 1269 * occur if we use keep-state the wrong way. 1270 */ 1271 if ( (q->state & ((TH_RST << 8)|TH_RST)) == 0) 1272 printf("invalid state: 0x%x\n", q->state); 1273#endif 1274 if (dyn_rst_lifetime >= dyn_keepalive_period) 1275 dyn_rst_lifetime = dyn_keepalive_period - 1; 1276 q->expire = time_second + dyn_rst_lifetime; 1277 break; 1278 } 1279 } else if (pkt->proto == IPPROTO_UDP) { 1280 q->expire = time_second + dyn_udp_lifetime; 1281 } else { 1282 /* other protocols */ 1283 q->expire = time_second + dyn_short_lifetime; 1284 } 1285done: 1286 if (match_direction) 1287 *match_direction = dir; 1288 return q; 1289} 1290 1291static ipfw_dyn_rule * 1292lookup_dyn_rule(struct ipfw_flow_id *pkt, int *match_direction, 1293 struct tcphdr *tcp) 1294{ 1295 ipfw_dyn_rule *q; 1296 1297 IPFW_DYN_LOCK(); 1298 q = lookup_dyn_rule_locked(pkt, match_direction, tcp); 1299 if (q == NULL) 1300 IPFW_DYN_UNLOCK(); 1301 /* NB: return table locked when q is not NULL */ 1302 return q; 1303} 1304 1305static void 1306realloc_dynamic_table(void) 1307{ 1308 IPFW_DYN_LOCK_ASSERT(); 1309 1310 /* 1311 * Try reallocation, make sure we have a power of 2 and do 1312 * not allow more than 64k entries. In case of overflow, 1313 * default to 1024. 1314 */ 1315 1316 if (dyn_buckets > 65536) 1317 dyn_buckets = 1024; 1318 if ((dyn_buckets & (dyn_buckets-1)) != 0) { /* not a power of 2 */ 1319 dyn_buckets = curr_dyn_buckets; /* reset */ 1320 return; 1321 } 1322 curr_dyn_buckets = dyn_buckets; 1323 if (ipfw_dyn_v != NULL) 1324 free(ipfw_dyn_v, M_IPFW); 1325 for (;;) { 1326 ipfw_dyn_v = malloc(curr_dyn_buckets * sizeof(ipfw_dyn_rule *), 1327 M_IPFW, M_NOWAIT | M_ZERO); 1328 if (ipfw_dyn_v != NULL || curr_dyn_buckets <= 2) 1329 break; 1330 curr_dyn_buckets /= 2; 1331 } 1332} 1333 1334/** 1335 * Install state of type 'type' for a dynamic session. 1336 * The hash table contains two type of rules: 1337 * - regular rules (O_KEEP_STATE) 1338 * - rules for sessions with limited number of sess per user 1339 * (O_LIMIT). When they are created, the parent is 1340 * increased by 1, and decreased on delete. In this case, 1341 * the third parameter is the parent rule and not the chain. 1342 * - "parent" rules for the above (O_LIMIT_PARENT). 1343 */ 1344static ipfw_dyn_rule * 1345add_dyn_rule(struct ipfw_flow_id *id, u_int8_t dyn_type, struct ip_fw *rule) 1346{ 1347 ipfw_dyn_rule *r; 1348 int i; 1349 1350 IPFW_DYN_LOCK_ASSERT(); 1351 1352 if (ipfw_dyn_v == NULL || 1353 (dyn_count == 0 && dyn_buckets != curr_dyn_buckets)) { 1354 realloc_dynamic_table(); 1355 if (ipfw_dyn_v == NULL) 1356 return NULL; /* failed ! */ 1357 } 1358 i = hash_packet(id); 1359 1360 r = uma_zalloc(ipfw_dyn_rule_zone, M_NOWAIT | M_ZERO); 1361 if (r == NULL) { 1362 printf ("ipfw: sorry cannot allocate state\n"); 1363 return NULL; 1364 } 1365 1366 /* increase refcount on parent, and set pointer */ 1367 if (dyn_type == O_LIMIT) { 1368 ipfw_dyn_rule *parent = (ipfw_dyn_rule *)rule; 1369 if ( parent->dyn_type != O_LIMIT_PARENT) 1370 panic("invalid parent"); 1371 parent->count++; 1372 r->parent = parent; 1373 rule = parent->rule; 1374 } 1375 1376 r->id = *id; 1377 r->expire = time_second + dyn_syn_lifetime; 1378 r->rule = rule; 1379 r->dyn_type = dyn_type; 1380 r->pcnt = r->bcnt = 0; 1381 r->count = 0; 1382 1383 r->bucket = i; 1384 r->next = ipfw_dyn_v[i]; 1385 ipfw_dyn_v[i] = r; 1386 dyn_count++; 1387 DEB(printf("ipfw: add dyn entry ty %d 0x%08x %d -> 0x%08x %d, total %d\n", 1388 dyn_type, 1389 (r->id.src_ip), (r->id.src_port), 1390 (r->id.dst_ip), (r->id.dst_port), 1391 dyn_count ); ) 1392 return r; 1393} 1394 1395/** 1396 * lookup dynamic parent rule using pkt and rule as search keys. 1397 * If the lookup fails, then install one. 1398 */ 1399static ipfw_dyn_rule * 1400lookup_dyn_parent(struct ipfw_flow_id *pkt, struct ip_fw *rule) 1401{ 1402 ipfw_dyn_rule *q; 1403 int i; 1404 1405 IPFW_DYN_LOCK_ASSERT(); 1406 1407 if (ipfw_dyn_v) { 1408 int is_v6 = IS_IP6_FLOW_ID(pkt); 1409 i = hash_packet( pkt ); 1410 for (q = ipfw_dyn_v[i] ; q != NULL ; q=q->next) 1411 if (q->dyn_type == O_LIMIT_PARENT && 1412 rule== q->rule && 1413 pkt->proto == q->id.proto && 1414 pkt->src_port == q->id.src_port && 1415 pkt->dst_port == q->id.dst_port && 1416 ( 1417 (is_v6 && 1418 IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1419 &(q->id.src_ip6)) && 1420 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1421 &(q->id.dst_ip6))) || 1422 (!is_v6 && 1423 pkt->src_ip == q->id.src_ip && 1424 pkt->dst_ip == q->id.dst_ip) 1425 ) 1426 ) { 1427 q->expire = time_second + dyn_short_lifetime; 1428 DEB(printf("ipfw: lookup_dyn_parent found 0x%p\n",q);) 1429 return q; 1430 } 1431 } 1432 return add_dyn_rule(pkt, O_LIMIT_PARENT, rule); 1433} 1434 1435/** 1436 * Install dynamic state for rule type cmd->o.opcode 1437 * 1438 * Returns 1 (failure) if state is not installed because of errors or because 1439 * session limitations are enforced. 1440 */ 1441static int 1442install_state(struct ip_fw *rule, ipfw_insn_limit *cmd, 1443 struct ip_fw_args *args) 1444{ 1445 static int last_log; 1446 1447 ipfw_dyn_rule *q; 1448 1449 DEB(printf("ipfw: install state type %d 0x%08x %u -> 0x%08x %u\n", 1450 cmd->o.opcode, 1451 (args->f_id.src_ip), (args->f_id.src_port), 1452 (args->f_id.dst_ip), (args->f_id.dst_port) );) 1453 1454 IPFW_DYN_LOCK(); 1455 1456 q = lookup_dyn_rule_locked(&args->f_id, NULL, NULL); 1457 1458 if (q != NULL) { /* should never occur */ 1459 if (last_log != time_second) { 1460 last_log = time_second; 1461 printf("ipfw: install_state: entry already present, done\n"); 1462 } 1463 IPFW_DYN_UNLOCK(); 1464 return 0; 1465 } 1466 1467 if (dyn_count >= dyn_max) 1468 /* 1469 * Run out of slots, try to remove any expired rule. 1470 */ 1471 remove_dyn_rule(NULL, (ipfw_dyn_rule *)1); 1472 1473 if (dyn_count >= dyn_max) { 1474 if (last_log != time_second) { 1475 last_log = time_second; 1476 printf("ipfw: install_state: Too many dynamic rules\n"); 1477 } 1478 IPFW_DYN_UNLOCK(); 1479 return 1; /* cannot install, notify caller */ 1480 } 1481 1482 switch (cmd->o.opcode) { 1483 case O_KEEP_STATE: /* bidir rule */ 1484 add_dyn_rule(&args->f_id, O_KEEP_STATE, rule); 1485 break; 1486 1487 case O_LIMIT: /* limit number of sessions */ 1488 { 1489 u_int16_t limit_mask = cmd->limit_mask; 1490 struct ipfw_flow_id id; 1491 ipfw_dyn_rule *parent; 1492 1493 DEB(printf("ipfw: installing dyn-limit rule %d\n", 1494 cmd->conn_limit);) 1495 1496 id.dst_ip = id.src_ip = 0; 1497 id.dst_port = id.src_port = 0; 1498 id.proto = args->f_id.proto; 1499 1500 if (IS_IP6_FLOW_ID (&(args->f_id))) { 1501 if (limit_mask & DYN_SRC_ADDR) 1502 id.src_ip6 = args->f_id.src_ip6; 1503 if (limit_mask & DYN_DST_ADDR) 1504 id.dst_ip6 = args->f_id.dst_ip6; 1505 } else { 1506 if (limit_mask & DYN_SRC_ADDR) 1507 id.src_ip = args->f_id.src_ip; 1508 if (limit_mask & DYN_DST_ADDR) 1509 id.dst_ip = args->f_id.dst_ip; 1510 } 1511 if (limit_mask & DYN_SRC_PORT) 1512 id.src_port = args->f_id.src_port; 1513 if (limit_mask & DYN_DST_PORT) 1514 id.dst_port = args->f_id.dst_port; 1515 parent = lookup_dyn_parent(&id, rule); 1516 if (parent == NULL) { 1517 printf("ipfw: add parent failed\n"); 1518 IPFW_DYN_UNLOCK(); 1519 return 1; 1520 } 1521 if (parent->count >= cmd->conn_limit) { 1522 /* 1523 * See if we can remove some expired rule. 1524 */ 1525 remove_dyn_rule(rule, parent); 1526 if (parent->count >= cmd->conn_limit) { 1527 if (fw_verbose && last_log != time_second) { 1528 last_log = time_second; 1529 log(LOG_SECURITY | LOG_DEBUG, 1530 "drop session, too many entries\n"); 1531 } 1532 IPFW_DYN_UNLOCK(); 1533 return 1; 1534 } 1535 } 1536 add_dyn_rule(&args->f_id, O_LIMIT, (struct ip_fw *)parent); 1537 } 1538 break; 1539 default: 1540 printf("ipfw: unknown dynamic rule type %u\n", cmd->o.opcode); 1541 IPFW_DYN_UNLOCK(); 1542 return 1; 1543 } 1544 lookup_dyn_rule_locked(&args->f_id, NULL, NULL); /* XXX just set lifetime */ 1545 IPFW_DYN_UNLOCK(); 1546 return 0; 1547} 1548 1549/* 1550 * Generate a TCP packet, containing either a RST or a keepalive. 1551 * When flags & TH_RST, we are sending a RST packet, because of a 1552 * "reset" action matched the packet. 1553 * Otherwise we are sending a keepalive, and flags & TH_ 1554 */ 1555static struct mbuf * 1556send_pkt(struct ipfw_flow_id *id, u_int32_t seq, u_int32_t ack, int flags) 1557{ 1558 struct mbuf *m; 1559 struct ip *ip; 1560 struct tcphdr *tcp; 1561 1562 MGETHDR(m, M_DONTWAIT, MT_HEADER); 1563 if (m == 0) 1564 return (NULL); 1565 m->m_pkthdr.rcvif = (struct ifnet *)0; 1566 m->m_pkthdr.len = m->m_len = sizeof(struct ip) + sizeof(struct tcphdr); 1567 m->m_data += max_linkhdr; 1568 1569 ip = mtod(m, struct ip *); 1570 bzero(ip, m->m_len); 1571 tcp = (struct tcphdr *)(ip + 1); /* no IP options */ 1572 ip->ip_p = IPPROTO_TCP; 1573 tcp->th_off = 5; 1574 /* 1575 * Assume we are sending a RST (or a keepalive in the reverse 1576 * direction), swap src and destination addresses and ports. 1577 */ 1578 ip->ip_src.s_addr = htonl(id->dst_ip); 1579 ip->ip_dst.s_addr = htonl(id->src_ip); 1580 tcp->th_sport = htons(id->dst_port); 1581 tcp->th_dport = htons(id->src_port); 1582 if (flags & TH_RST) { /* we are sending a RST */ 1583 if (flags & TH_ACK) { 1584 tcp->th_seq = htonl(ack); 1585 tcp->th_ack = htonl(0); 1586 tcp->th_flags = TH_RST; 1587 } else { 1588 if (flags & TH_SYN) 1589 seq++; 1590 tcp->th_seq = htonl(0); 1591 tcp->th_ack = htonl(seq); 1592 tcp->th_flags = TH_RST | TH_ACK; 1593 } 1594 } else { 1595 /* 1596 * We are sending a keepalive. flags & TH_SYN determines 1597 * the direction, forward if set, reverse if clear. 1598 * NOTE: seq and ack are always assumed to be correct 1599 * as set by the caller. This may be confusing... 1600 */ 1601 if (flags & TH_SYN) { 1602 /* 1603 * we have to rewrite the correct addresses! 1604 */ 1605 ip->ip_dst.s_addr = htonl(id->dst_ip); 1606 ip->ip_src.s_addr = htonl(id->src_ip); 1607 tcp->th_dport = htons(id->dst_port); 1608 tcp->th_sport = htons(id->src_port); 1609 } 1610 tcp->th_seq = htonl(seq); 1611 tcp->th_ack = htonl(ack); 1612 tcp->th_flags = TH_ACK; 1613 } 1614 /* 1615 * set ip_len to the payload size so we can compute 1616 * the tcp checksum on the pseudoheader 1617 * XXX check this, could save a couple of words ? 1618 */ 1619 ip->ip_len = htons(sizeof(struct tcphdr)); 1620 tcp->th_sum = in_cksum(m, m->m_pkthdr.len); 1621 /* 1622 * now fill fields left out earlier 1623 */ 1624 ip->ip_ttl = ip_defttl; 1625 ip->ip_len = m->m_pkthdr.len; 1626 m->m_flags |= M_SKIP_FIREWALL; 1627 return (m); 1628} 1629 1630/* 1631 * sends a reject message, consuming the mbuf passed as an argument. 1632 */ 1633static void 1634send_reject(struct ip_fw_args *args, int code, u_short offset, int ip_len) 1635{ 1636 1637 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */ 1638 /* We need the IP header in host order for icmp_error(). */ 1639 if (args->eh != NULL) { 1640 struct ip *ip = mtod(args->m, struct ip *); 1641 ip->ip_len = ntohs(ip->ip_len); 1642 ip->ip_off = ntohs(ip->ip_off); 1643 } 1644 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 1645 } else if (offset == 0 && args->f_id.proto == IPPROTO_TCP) { 1646 struct tcphdr *const tcp = 1647 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 1648 if ( (tcp->th_flags & TH_RST) == 0) { 1649 struct mbuf *m; 1650 m = send_pkt(&(args->f_id), ntohl(tcp->th_seq), 1651 ntohl(tcp->th_ack), 1652 tcp->th_flags | TH_RST); 1653 if (m != NULL) 1654 ip_output(m, NULL, NULL, 0, NULL, NULL); 1655 } 1656 m_freem(args->m); 1657 } else 1658 m_freem(args->m); 1659 args->m = NULL; 1660} 1661 1662/** 1663 * 1664 * Given an ip_fw *, lookup_next_rule will return a pointer 1665 * to the next rule, which can be either the jump 1666 * target (for skipto instructions) or the next one in the list (in 1667 * all other cases including a missing jump target). 1668 * The result is also written in the "next_rule" field of the rule. 1669 * Backward jumps are not allowed, so start looking from the next 1670 * rule... 1671 * 1672 * This never returns NULL -- in case we do not have an exact match, 1673 * the next rule is returned. When the ruleset is changed, 1674 * pointers are flushed so we are always correct. 1675 */ 1676 1677static struct ip_fw * 1678lookup_next_rule(struct ip_fw *me) 1679{ 1680 struct ip_fw *rule = NULL; 1681 ipfw_insn *cmd; 1682 1683 /* look for action, in case it is a skipto */ 1684 cmd = ACTION_PTR(me); 1685 if (cmd->opcode == O_LOG) 1686 cmd += F_LEN(cmd); 1687 if (cmd->opcode == O_ALTQ) 1688 cmd += F_LEN(cmd); 1689 if ( cmd->opcode == O_SKIPTO ) 1690 for (rule = me->next; rule ; rule = rule->next) 1691 if (rule->rulenum >= cmd->arg1) 1692 break; 1693 if (rule == NULL) /* failure or not a skipto */ 1694 rule = me->next; 1695 me->next_rule = rule; 1696 return rule; 1697} 1698 1699static void 1700init_tables(void) 1701{ 1702 int i; 1703 1704 for (i = 0; i < IPFW_TABLES_MAX; i++) { 1705 rn_inithead((void **)&ipfw_tables[i].rnh, 32); 1706 ipfw_tables[i].modified = 1; 1707 } 1708} 1709 1710static int 1711add_table_entry(u_int16_t tbl, in_addr_t addr, u_int8_t mlen, u_int32_t value) 1712{ 1713 struct radix_node_head *rnh; 1714 struct table_entry *ent; 1715 1716 if (tbl >= IPFW_TABLES_MAX) 1717 return (EINVAL); 1718 rnh = ipfw_tables[tbl].rnh; 1719 ent = malloc(sizeof(*ent), M_IPFW_TBL, M_NOWAIT | M_ZERO); 1720 if (ent == NULL) 1721 return (ENOMEM); 1722 ent->value = value; 1723 ent->addr.sin_len = ent->mask.sin_len = 8; 1724 ent->mask.sin_addr.s_addr = htonl(mlen ? ~((1 << (32 - mlen)) - 1) : 0); 1725 ent->addr.sin_addr.s_addr = addr & ent->mask.sin_addr.s_addr; 1726 RADIX_NODE_HEAD_LOCK(rnh); 1727 if (rnh->rnh_addaddr(&ent->addr, &ent->mask, rnh, (void *)ent) == 1728 NULL) { 1729 RADIX_NODE_HEAD_UNLOCK(rnh); 1730 free(ent, M_IPFW_TBL); 1731 return (EEXIST); 1732 } 1733 ipfw_tables[tbl].modified = 1; 1734 RADIX_NODE_HEAD_UNLOCK(rnh); 1735 return (0); 1736} 1737 1738static int 1739del_table_entry(u_int16_t tbl, in_addr_t addr, u_int8_t mlen) 1740{ 1741 struct radix_node_head *rnh; 1742 struct table_entry *ent; 1743 struct sockaddr_in sa, mask; 1744 1745 if (tbl >= IPFW_TABLES_MAX) 1746 return (EINVAL); 1747 rnh = ipfw_tables[tbl].rnh; 1748 sa.sin_len = mask.sin_len = 8; 1749 mask.sin_addr.s_addr = htonl(mlen ? ~((1 << (32 - mlen)) - 1) : 0); 1750 sa.sin_addr.s_addr = addr & mask.sin_addr.s_addr; 1751 RADIX_NODE_HEAD_LOCK(rnh); 1752 ent = (struct table_entry *)rnh->rnh_deladdr(&sa, &mask, rnh); 1753 if (ent == NULL) { 1754 RADIX_NODE_HEAD_UNLOCK(rnh); 1755 return (ESRCH); 1756 } 1757 ipfw_tables[tbl].modified = 1; 1758 RADIX_NODE_HEAD_UNLOCK(rnh); 1759 free(ent, M_IPFW_TBL); 1760 return (0); 1761} 1762 1763static int 1764flush_table_entry(struct radix_node *rn, void *arg) 1765{ 1766 struct radix_node_head * const rnh = arg; 1767 struct table_entry *ent; 1768 1769 ent = (struct table_entry *) 1770 rnh->rnh_deladdr(rn->rn_key, rn->rn_mask, rnh); 1771 if (ent != NULL) 1772 free(ent, M_IPFW_TBL); 1773 return (0); 1774} 1775 1776static int 1777flush_table(u_int16_t tbl) 1778{ 1779 struct radix_node_head *rnh; 1780 1781 if (tbl >= IPFW_TABLES_MAX) 1782 return (EINVAL); 1783 rnh = ipfw_tables[tbl].rnh; 1784 RADIX_NODE_HEAD_LOCK(rnh); 1785 rnh->rnh_walktree(rnh, flush_table_entry, rnh); 1786 ipfw_tables[tbl].modified = 1; 1787 RADIX_NODE_HEAD_UNLOCK(rnh); 1788 return (0); 1789} 1790 1791static void 1792flush_tables(void) 1793{ 1794 u_int16_t tbl; 1795 1796 for (tbl = 0; tbl < IPFW_TABLES_MAX; tbl++) 1797 flush_table(tbl); 1798} 1799 1800static int 1801lookup_table(u_int16_t tbl, in_addr_t addr, u_int32_t *val) 1802{ 1803 struct radix_node_head *rnh; 1804 struct ip_fw_table *table; 1805 struct table_entry *ent; 1806 struct sockaddr_in sa; 1807 int last_match; 1808 1809 if (tbl >= IPFW_TABLES_MAX) 1810 return (0); 1811 table = &ipfw_tables[tbl]; 1812 rnh = table->rnh; 1813 RADIX_NODE_HEAD_LOCK(rnh); 1814 if (addr == table->last_addr && !table->modified) { 1815 last_match = table->last_match; 1816 if (last_match) 1817 *val = table->last_value; 1818 RADIX_NODE_HEAD_UNLOCK(rnh); 1819 return (last_match); 1820 } 1821 table->modified = 0; 1822 sa.sin_len = 8; 1823 sa.sin_addr.s_addr = addr; 1824 ent = (struct table_entry *)(rnh->rnh_lookup(&sa, NULL, rnh)); 1825 table->last_addr = addr; 1826 if (ent != NULL) { 1827 table->last_value = *val = ent->value; 1828 table->last_match = 1; 1829 RADIX_NODE_HEAD_UNLOCK(rnh); 1830 return (1); 1831 } 1832 table->last_match = 0; 1833 RADIX_NODE_HEAD_UNLOCK(rnh); 1834 return (0); 1835} 1836 1837static int 1838count_table_entry(struct radix_node *rn, void *arg) 1839{ 1840 u_int32_t * const cnt = arg; 1841 1842 (*cnt)++; 1843 return (0); 1844} 1845 1846static int 1847count_table(u_int32_t tbl, u_int32_t *cnt) 1848{ 1849 struct radix_node_head *rnh; 1850 1851 if (tbl >= IPFW_TABLES_MAX) 1852 return (EINVAL); 1853 rnh = ipfw_tables[tbl].rnh; 1854 *cnt = 0; 1855 RADIX_NODE_HEAD_LOCK(rnh); 1856 rnh->rnh_walktree(rnh, count_table_entry, cnt); 1857 RADIX_NODE_HEAD_UNLOCK(rnh); 1858 return (0); 1859} 1860 1861static int 1862dump_table_entry(struct radix_node *rn, void *arg) 1863{ 1864 struct table_entry * const n = (struct table_entry *)rn; 1865 ipfw_table * const tbl = arg; 1866 ipfw_table_entry *ent; 1867 1868 if (tbl->cnt == tbl->size) 1869 return (1); 1870 ent = &tbl->ent[tbl->cnt]; 1871 ent->tbl = tbl->tbl; 1872 if (in_nullhost(n->mask.sin_addr)) 1873 ent->masklen = 0; 1874 else 1875 ent->masklen = 33 - ffs(ntohl(n->mask.sin_addr.s_addr)); 1876 ent->addr = n->addr.sin_addr.s_addr; 1877 ent->value = n->value; 1878 tbl->cnt++; 1879 return (0); 1880} 1881 1882static int 1883dump_table(ipfw_table *tbl) 1884{ 1885 struct radix_node_head *rnh; 1886 1887 if (tbl->tbl >= IPFW_TABLES_MAX) 1888 return (EINVAL); 1889 rnh = ipfw_tables[tbl->tbl].rnh; 1890 tbl->cnt = 0; 1891 RADIX_NODE_HEAD_LOCK(rnh); 1892 rnh->rnh_walktree(rnh, dump_table_entry, tbl); 1893 RADIX_NODE_HEAD_UNLOCK(rnh); 1894 return (0); 1895} 1896 1897static void 1898fill_ugid_cache(struct inpcb *inp, struct ip_fw_ugid *ugp) 1899{ 1900 struct ucred *cr; 1901 1902 if (inp->inp_socket != NULL) { 1903 cr = inp->inp_socket->so_cred; 1904 ugp->fw_prid = jailed(cr) ? 1905 cr->cr_prison->pr_id : -1; 1906 ugp->fw_uid = cr->cr_uid; 1907 ugp->fw_ngroups = cr->cr_ngroups; 1908 bcopy(cr->cr_groups, ugp->fw_groups, 1909 sizeof(ugp->fw_groups)); 1910 } 1911} 1912 1913static int 1914check_uidgid(ipfw_insn_u32 *insn, 1915 int proto, struct ifnet *oif, 1916 struct in_addr dst_ip, u_int16_t dst_port, 1917 struct in_addr src_ip, u_int16_t src_port, 1918 struct ip_fw_ugid *ugp, int *lookup, struct inpcb *inp) 1919{ 1920 struct inpcbinfo *pi; 1921 int wildcard; 1922 struct inpcb *pcb; 1923 int match; 1924 gid_t *gp; 1925 1926 /* 1927 * Check to see if the UDP or TCP stack supplied us with 1928 * the PCB. If so, rather then holding a lock and looking 1929 * up the PCB, we can use the one that was supplied. 1930 */ 1931 if (inp && *lookup == 0) { 1932 INP_LOCK_ASSERT(inp); 1933 if (inp->inp_socket != NULL) { 1934 fill_ugid_cache(inp, ugp); 1935 *lookup = 1; 1936 } 1937 } 1938 /* 1939 * If we have already been here and the packet has no 1940 * PCB entry associated with it, then we can safely 1941 * assume that this is a no match. 1942 */ 1943 if (*lookup == -1) 1944 return (0); 1945 if (proto == IPPROTO_TCP) { 1946 wildcard = 0; 1947 pi = &tcbinfo; 1948 } else if (proto == IPPROTO_UDP) { 1949 wildcard = 1; 1950 pi = &udbinfo; 1951 } else 1952 return 0; 1953 match = 0; 1954 if (*lookup == 0) { 1955 INP_INFO_RLOCK(pi); 1956 pcb = (oif) ? 1957 in_pcblookup_hash(pi, 1958 dst_ip, htons(dst_port), 1959 src_ip, htons(src_port), 1960 wildcard, oif) : 1961 in_pcblookup_hash(pi, 1962 src_ip, htons(src_port), 1963 dst_ip, htons(dst_port), 1964 wildcard, NULL); 1965 if (pcb != NULL) { 1966 INP_LOCK(pcb); 1967 if (pcb->inp_socket != NULL) { 1968 fill_ugid_cache(pcb, ugp); 1969 *lookup = 1; 1970 } 1971 INP_UNLOCK(pcb); 1972 } 1973 INP_INFO_RUNLOCK(pi); 1974 if (*lookup == 0) { 1975 /* 1976 * If the lookup did not yield any results, there 1977 * is no sense in coming back and trying again. So 1978 * we can set lookup to -1 and ensure that we wont 1979 * bother the pcb system again. 1980 */ 1981 *lookup = -1; 1982 return (0); 1983 } 1984 } 1985 if (insn->o.opcode == O_UID) 1986 match = (ugp->fw_uid == (uid_t)insn->d[0]); 1987 else if (insn->o.opcode == O_GID) { 1988 for (gp = ugp->fw_groups; 1989 gp < &ugp->fw_groups[ugp->fw_ngroups]; gp++) 1990 if (*gp == (gid_t)insn->d[0]) { 1991 match = 1; 1992 break; 1993 } 1994 } else if (insn->o.opcode == O_JAIL) 1995 match = (ugp->fw_prid == (int)insn->d[0]); 1996 return match; 1997} 1998 1999/* 2000 * The main check routine for the firewall. 2001 * 2002 * All arguments are in args so we can modify them and return them 2003 * back to the caller. 2004 * 2005 * Parameters: 2006 * 2007 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 2008 * Starts with the IP header. 2009 * args->eh (in) Mac header if present, or NULL for layer3 packet. 2010 * args->oif Outgoing interface, or NULL if packet is incoming. 2011 * The incoming interface is in the mbuf. (in) 2012 * args->divert_rule (in/out) 2013 * Skip up to the first rule past this rule number; 2014 * upon return, non-zero port number for divert or tee. 2015 * 2016 * args->rule Pointer to the last matching rule (in/out) 2017 * args->next_hop Socket we are forwarding to (out). 2018 * args->f_id Addresses grabbed from the packet (out) 2019 * args->cookie a cookie depending on rule action 2020 * 2021 * Return value: 2022 * 2023 * IP_FW_PASS the packet must be accepted 2024 * IP_FW_DENY the packet must be dropped 2025 * IP_FW_DIVERT divert packet, port in m_tag 2026 * IP_FW_TEE tee packet, port in m_tag 2027 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 2028 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 2029 * 2030 */ 2031 2032int 2033ipfw_chk(struct ip_fw_args *args) 2034{ 2035 /* 2036 * Local variables hold state during the processing of a packet. 2037 * 2038 * IMPORTANT NOTE: to speed up the processing of rules, there 2039 * are some assumption on the values of the variables, which 2040 * are documented here. Should you change them, please check 2041 * the implementation of the various instructions to make sure 2042 * that they still work. 2043 * 2044 * args->eh The MAC header. It is non-null for a layer2 2045 * packet, it is NULL for a layer-3 packet. 2046 * 2047 * m | args->m Pointer to the mbuf, as received from the caller. 2048 * It may change if ipfw_chk() does an m_pullup, or if it 2049 * consumes the packet because it calls send_reject(). 2050 * XXX This has to change, so that ipfw_chk() never modifies 2051 * or consumes the buffer. 2052 * ip is simply an alias of the value of m, and it is kept 2053 * in sync with it (the packet is supposed to start with 2054 * the ip header). 2055 */ 2056 struct mbuf *m = args->m; 2057 struct ip *ip = mtod(m, struct ip *); 2058 2059 /* 2060 * For rules which contain uid/gid or jail constraints, cache 2061 * a copy of the users credentials after the pcb lookup has been 2062 * executed. This will speed up the processing of rules with 2063 * these types of constraints, as well as decrease contention 2064 * on pcb related locks. 2065 */ 2066 struct ip_fw_ugid fw_ugid_cache; 2067 int ugid_lookup = 0; 2068 2069 /* 2070 * divinput_flags If non-zero, set to the IP_FW_DIVERT_*_FLAG 2071 * associated with a packet input on a divert socket. This 2072 * will allow to distinguish traffic and its direction when 2073 * it originates from a divert socket. 2074 */ 2075 u_int divinput_flags = 0; 2076 2077 /* 2078 * oif | args->oif If NULL, ipfw_chk has been called on the 2079 * inbound path (ether_input, bdg_forward, ip_input). 2080 * If non-NULL, ipfw_chk has been called on the outbound path 2081 * (ether_output, ip_output). 2082 */ 2083 struct ifnet *oif = args->oif; 2084 2085 struct ip_fw *f = NULL; /* matching rule */ 2086 int retval = 0; 2087 2088 /* 2089 * hlen The length of the IP header. 2090 */ 2091 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 2092 2093 /* 2094 * offset The offset of a fragment. offset != 0 means that 2095 * we have a fragment at this offset of an IPv4 packet. 2096 * offset == 0 means that (if this is an IPv4 packet) 2097 * this is the first or only fragment. 2098 * For IPv6 offset == 0 means there is no Fragment Header. 2099 * If offset != 0 for IPv6 always use correct mask to 2100 * get the correct offset because we add IP6F_MORE_FRAG 2101 * to be able to dectect the first fragment which would 2102 * otherwise have offset = 0. 2103 */ 2104 u_short offset = 0; 2105 2106 /* 2107 * Local copies of addresses. They are only valid if we have 2108 * an IP packet. 2109 * 2110 * proto The protocol. Set to 0 for non-ip packets, 2111 * or to the protocol read from the packet otherwise. 2112 * proto != 0 means that we have an IPv4 packet. 2113 * 2114 * src_port, dst_port port numbers, in HOST format. Only 2115 * valid for TCP and UDP packets. 2116 * 2117 * src_ip, dst_ip ip addresses, in NETWORK format. 2118 * Only valid for IPv4 packets. 2119 */ 2120 u_int8_t proto; 2121 u_int16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 2122 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 2123 u_int16_t ip_len=0; 2124 int pktlen; 2125 2126 /* 2127 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 2128 * MATCH_NONE when checked and not matched (q = NULL), 2129 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) 2130 */ 2131 int dyn_dir = MATCH_UNKNOWN; 2132 ipfw_dyn_rule *q = NULL; 2133 struct ip_fw_chain *chain = &layer3_chain; 2134 struct m_tag *mtag; 2135 2136 /* 2137 * We store in ulp a pointer to the upper layer protocol header. 2138 * In the ipv4 case this is easy to determine from the header, 2139 * but for ipv6 we might have some additional headers in the middle. 2140 * ulp is NULL if not found. 2141 */ 2142 void *ulp = NULL; /* upper layer protocol pointer. */ 2143 /* XXX ipv6 variables */ 2144 int is_ipv6 = 0; 2145 u_int16_t ext_hd = 0; /* bits vector for extension header filtering */ 2146 /* end of ipv6 variables */ 2147 int is_ipv4 = 0; 2148 2149 if (m->m_flags & M_SKIP_FIREWALL) 2150 return (IP_FW_PASS); /* accept */ 2151 2152 pktlen = m->m_pkthdr.len; 2153 proto = args->f_id.proto = 0; /* mark f_id invalid */ 2154 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ 2155 2156/* 2157 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 2158 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 2159 * pointer might become stale after other pullups (but we never use it 2160 * this way). 2161 */ 2162#define PULLUP_TO(len, p, T) \ 2163do { \ 2164 int x = (len) + sizeof(T); \ 2165 if ((m)->m_len < x) { \ 2166 args->m = m = m_pullup(m, x); \ 2167 if (m == NULL) \ 2168 goto pullup_failed; \ 2169 } \ 2170 p = (mtod(m, char *) + (len)); \ 2171} while (0) 2172 2173 /* Identify IP packets and fill up variables. */ 2174 if (pktlen >= sizeof(struct ip6_hdr) && 2175 (args->eh == NULL || ntohs(args->eh->ether_type)==ETHERTYPE_IPV6) && 2176 mtod(m, struct ip *)->ip_v == 6) { 2177 is_ipv6 = 1; 2178 args->f_id.addr_type = 6; 2179 hlen = sizeof(struct ip6_hdr); 2180 proto = mtod(m, struct ip6_hdr *)->ip6_nxt; 2181 2182 /* Search extension headers to find upper layer protocols */ 2183 while (ulp == NULL) { 2184 switch (proto) { 2185 case IPPROTO_ICMPV6: 2186 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 2187 args->f_id.flags = ICMP6(ulp)->icmp6_type; 2188 break; 2189 2190 case IPPROTO_TCP: 2191 PULLUP_TO(hlen, ulp, struct tcphdr); 2192 dst_port = TCP(ulp)->th_dport; 2193 src_port = TCP(ulp)->th_sport; 2194 args->f_id.flags = TCP(ulp)->th_flags; 2195 break; 2196 2197 case IPPROTO_UDP: 2198 PULLUP_TO(hlen, ulp, struct udphdr); 2199 dst_port = UDP(ulp)->uh_dport; 2200 src_port = UDP(ulp)->uh_sport; 2201 break; 2202 2203 case IPPROTO_HOPOPTS: /* RFC 2460 */ 2204 PULLUP_TO(hlen, ulp, struct ip6_hbh); 2205 ext_hd |= EXT_HOPOPTS; 2206 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 2207 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 2208 ulp = NULL; 2209 break; 2210 2211 case IPPROTO_ROUTING: /* RFC 2460 */ 2212 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 2213 if (((struct ip6_rthdr *)ulp)->ip6r_type != 0) { 2214 printf("IPFW2: IPV6 - Unknown Routing " 2215 "Header type(%d)\n", 2216 ((struct ip6_rthdr *)ulp)->ip6r_type); 2217 if (fw_deny_unknown_exthdrs) 2218 return (IP_FW_DENY); 2219 break; 2220 } 2221 ext_hd |= EXT_ROUTING; 2222 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 2223 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 2224 ulp = NULL; 2225 break; 2226 2227 case IPPROTO_FRAGMENT: /* RFC 2460 */ 2228 PULLUP_TO(hlen, ulp, struct ip6_frag); 2229 ext_hd |= EXT_FRAGMENT; 2230 hlen += sizeof (struct ip6_frag); 2231 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 2232 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 2233 IP6F_OFF_MASK; 2234 /* Add IP6F_MORE_FRAG for offset of first 2235 * fragment to be != 0. */ 2236 offset |= ((struct ip6_frag *)ulp)->ip6f_offlg & 2237 IP6F_MORE_FRAG; 2238 if (offset == 0) { 2239 printf("IPFW2: IPV6 - Invalid Fragment " 2240 "Header\n"); 2241 if (fw_deny_unknown_exthdrs) 2242 return (IP_FW_DENY); 2243 break; 2244 } 2245 args->f_id.frag_id6 = 2246 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 2247 ulp = NULL; 2248 break; 2249 2250 case IPPROTO_DSTOPTS: /* RFC 2460 */ 2251 PULLUP_TO(hlen, ulp, struct ip6_hbh); 2252 ext_hd |= EXT_DSTOPTS; 2253 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 2254 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 2255 ulp = NULL; 2256 break; 2257 2258 case IPPROTO_AH: /* RFC 2402 */ 2259 PULLUP_TO(hlen, ulp, struct ip6_ext); 2260 ext_hd |= EXT_AH; 2261 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 2262 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 2263 ulp = NULL; 2264 break; 2265 2266 case IPPROTO_ESP: /* RFC 2406 */ 2267 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 2268 /* Anything past Seq# is variable length and 2269 * data past this ext. header is encrypted. */ 2270 ext_hd |= EXT_ESP; 2271 break; 2272 2273 case IPPROTO_NONE: /* RFC 2460 */ 2274 PULLUP_TO(hlen, ulp, struct ip6_ext); 2275 /* Packet ends here. if ip6e_len!=0 octets 2276 * must be ignored. */ 2277 break; 2278 2279 case IPPROTO_OSPFIGP: 2280 /* XXX OSPF header check? */ 2281 PULLUP_TO(hlen, ulp, struct ip6_ext); 2282 break; 2283 2284 default: 2285 printf("IPFW2: IPV6 - Unknown Extension " 2286 "Header(%d), ext_hd=%x\n", proto, ext_hd); 2287 if (fw_deny_unknown_exthdrs) 2288 return (IP_FW_DENY); 2289 break; 2290 } /*switch */ 2291 } 2292 args->f_id.src_ip6 = mtod(m,struct ip6_hdr *)->ip6_src; 2293 args->f_id.dst_ip6 = mtod(m,struct ip6_hdr *)->ip6_dst; 2294 args->f_id.src_ip = 0; 2295 args->f_id.dst_ip = 0; 2296 args->f_id.flow_id6 = ntohl(mtod(m, struct ip6_hdr *)->ip6_flow); 2297 } else if (pktlen >= sizeof(struct ip) && 2298 (args->eh == NULL || ntohs(args->eh->ether_type) == ETHERTYPE_IP) && 2299 mtod(m, struct ip *)->ip_v == 4) { 2300 is_ipv4 = 1; 2301 ip = mtod(m, struct ip *); 2302 hlen = ip->ip_hl << 2; 2303 args->f_id.addr_type = 4; 2304 2305 /* 2306 * Collect parameters into local variables for faster matching. 2307 */ 2308 proto = ip->ip_p; 2309 src_ip = ip->ip_src; 2310 dst_ip = ip->ip_dst; 2311 if (args->eh != NULL) { /* layer 2 packets are as on the wire */ 2312 offset = ntohs(ip->ip_off) & IP_OFFMASK; 2313 ip_len = ntohs(ip->ip_len); 2314 } else { 2315 offset = ip->ip_off & IP_OFFMASK; 2316 ip_len = ip->ip_len; 2317 } 2318 pktlen = ip_len < pktlen ? ip_len : pktlen; 2319 2320 if (offset == 0) { 2321 switch (proto) { 2322 case IPPROTO_TCP: 2323 PULLUP_TO(hlen, ulp, struct tcphdr); 2324 dst_port = TCP(ulp)->th_dport; 2325 src_port = TCP(ulp)->th_sport; 2326 args->f_id.flags = TCP(ulp)->th_flags; 2327 break; 2328 2329 case IPPROTO_UDP: 2330 PULLUP_TO(hlen, ulp, struct udphdr); 2331 dst_port = UDP(ulp)->uh_dport; 2332 src_port = UDP(ulp)->uh_sport; 2333 break; 2334 2335 case IPPROTO_ICMP: 2336 PULLUP_TO(hlen, ulp, struct icmphdr); 2337 args->f_id.flags = ICMP(ulp)->icmp_type; 2338 break; 2339 2340 default: 2341 break; 2342 } 2343 } 2344 2345 args->f_id.src_ip = ntohl(src_ip.s_addr); 2346 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 2347 } 2348#undef PULLUP_TO 2349 if (proto) { /* we may have port numbers, store them */ 2350 args->f_id.proto = proto; 2351 args->f_id.src_port = src_port = ntohs(src_port); 2352 args->f_id.dst_port = dst_port = ntohs(dst_port); 2353 } 2354 2355 IPFW_RLOCK(chain); 2356 mtag = m_tag_find(m, PACKET_TAG_DIVERT, NULL); 2357 if (args->rule) { 2358 /* 2359 * Packet has already been tagged. Look for the next rule 2360 * to restart processing. 2361 * 2362 * If fw_one_pass != 0 then just accept it. 2363 * XXX should not happen here, but optimized out in 2364 * the caller. 2365 */ 2366 if (fw_one_pass) { 2367 IPFW_RUNLOCK(chain); 2368 return (IP_FW_PASS); 2369 } 2370 2371 f = args->rule->next_rule; 2372 if (f == NULL) 2373 f = lookup_next_rule(args->rule); 2374 } else { 2375 /* 2376 * Find the starting rule. It can be either the first 2377 * one, or the one after divert_rule if asked so. 2378 */ 2379 int skipto = mtag ? divert_cookie(mtag) : 0; 2380 2381 f = chain->rules; 2382 if (args->eh == NULL && skipto != 0) { 2383 if (skipto >= IPFW_DEFAULT_RULE) { 2384 IPFW_RUNLOCK(chain); 2385 return (IP_FW_DENY); /* invalid */ 2386 } 2387 while (f && f->rulenum <= skipto) 2388 f = f->next; 2389 if (f == NULL) { /* drop packet */ 2390 IPFW_RUNLOCK(chain); 2391 return (IP_FW_DENY); 2392 } 2393 } 2394 } 2395 /* reset divert rule to avoid confusion later */ 2396 if (mtag) { 2397 divinput_flags = divert_info(mtag) & 2398 (IP_FW_DIVERT_OUTPUT_FLAG | IP_FW_DIVERT_LOOPBACK_FLAG); 2399 m_tag_delete(m, mtag); 2400 } 2401 2402 /* 2403 * Now scan the rules, and parse microinstructions for each rule. 2404 */ 2405 for (; f; f = f->next) { 2406 int l, cmdlen; 2407 ipfw_insn *cmd; 2408 int skip_or; /* skip rest of OR block */ 2409 2410again: 2411 if (set_disable & (1 << f->set) ) 2412 continue; 2413 2414 skip_or = 0; 2415 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 2416 l -= cmdlen, cmd += cmdlen) { 2417 int match; 2418 2419 /* 2420 * check_body is a jump target used when we find a 2421 * CHECK_STATE, and need to jump to the body of 2422 * the target rule. 2423 */ 2424 2425check_body: 2426 cmdlen = F_LEN(cmd); 2427 /* 2428 * An OR block (insn_1 || .. || insn_n) has the 2429 * F_OR bit set in all but the last instruction. 2430 * The first match will set "skip_or", and cause 2431 * the following instructions to be skipped until 2432 * past the one with the F_OR bit clear. 2433 */ 2434 if (skip_or) { /* skip this instruction */ 2435 if ((cmd->len & F_OR) == 0) 2436 skip_or = 0; /* next one is good */ 2437 continue; 2438 } 2439 match = 0; /* set to 1 if we succeed */ 2440 2441 switch (cmd->opcode) { 2442 /* 2443 * The first set of opcodes compares the packet's 2444 * fields with some pattern, setting 'match' if a 2445 * match is found. At the end of the loop there is 2446 * logic to deal with F_NOT and F_OR flags associated 2447 * with the opcode. 2448 */ 2449 case O_NOP: 2450 match = 1; 2451 break; 2452 2453 case O_FORWARD_MAC: 2454 printf("ipfw: opcode %d unimplemented\n", 2455 cmd->opcode); 2456 break; 2457 2458 case O_GID: 2459 case O_UID: 2460 case O_JAIL: 2461 /* 2462 * We only check offset == 0 && proto != 0, 2463 * as this ensures that we have a 2464 * packet with the ports info. 2465 */ 2466 if (offset!=0) 2467 break; 2468 if (is_ipv6) /* XXX to be fixed later */ 2469 break; 2470 if (proto == IPPROTO_TCP || 2471 proto == IPPROTO_UDP) 2472 match = check_uidgid( 2473 (ipfw_insn_u32 *)cmd, 2474 proto, oif, 2475 dst_ip, dst_port, 2476 src_ip, src_port, &fw_ugid_cache, 2477 &ugid_lookup, args->inp); 2478 break; 2479 2480 case O_RECV: 2481 match = iface_match(m->m_pkthdr.rcvif, 2482 (ipfw_insn_if *)cmd); 2483 break; 2484 2485 case O_XMIT: 2486 match = iface_match(oif, (ipfw_insn_if *)cmd); 2487 break; 2488 2489 case O_VIA: 2490 match = iface_match(oif ? oif : 2491 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd); 2492 break; 2493 2494 case O_MACADDR2: 2495 if (args->eh != NULL) { /* have MAC header */ 2496 u_int32_t *want = (u_int32_t *) 2497 ((ipfw_insn_mac *)cmd)->addr; 2498 u_int32_t *mask = (u_int32_t *) 2499 ((ipfw_insn_mac *)cmd)->mask; 2500 u_int32_t *hdr = (u_int32_t *)args->eh; 2501 2502 match = 2503 ( want[0] == (hdr[0] & mask[0]) && 2504 want[1] == (hdr[1] & mask[1]) && 2505 want[2] == (hdr[2] & mask[2]) ); 2506 } 2507 break; 2508 2509 case O_MAC_TYPE: 2510 if (args->eh != NULL) { 2511 u_int16_t t = 2512 ntohs(args->eh->ether_type); 2513 u_int16_t *p = 2514 ((ipfw_insn_u16 *)cmd)->ports; 2515 int i; 2516 2517 for (i = cmdlen - 1; !match && i>0; 2518 i--, p += 2) 2519 match = (t>=p[0] && t<=p[1]); 2520 } 2521 break; 2522 2523 case O_FRAG: 2524 match = (offset != 0); 2525 break; 2526 2527 case O_IN: /* "out" is "not in" */ 2528 match = (oif == NULL); 2529 break; 2530 2531 case O_LAYER2: 2532 match = (args->eh != NULL); 2533 break; 2534 2535 case O_DIVERTED: 2536 match = (cmd->arg1 & 1 && divinput_flags & 2537 IP_FW_DIVERT_LOOPBACK_FLAG) || 2538 (cmd->arg1 & 2 && divinput_flags & 2539 IP_FW_DIVERT_OUTPUT_FLAG); 2540 break; 2541 2542 case O_PROTO: 2543 /* 2544 * We do not allow an arg of 0 so the 2545 * check of "proto" only suffices. 2546 */ 2547 match = (proto == cmd->arg1); 2548 break; 2549 2550 case O_IP_SRC: 2551 match = is_ipv4 && 2552 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2553 src_ip.s_addr); 2554 break; 2555 2556 case O_IP_SRC_LOOKUP: 2557 case O_IP_DST_LOOKUP: 2558 if (is_ipv4) { 2559 uint32_t a = 2560 (cmd->opcode == O_IP_DST_LOOKUP) ? 2561 dst_ip.s_addr : src_ip.s_addr; 2562 uint32_t v; 2563 2564 match = lookup_table(cmd->arg1, a, &v); 2565 if (!match) 2566 break; 2567 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 2568 match = 2569 ((ipfw_insn_u32 *)cmd)->d[0] == v; 2570 } 2571 break; 2572 2573 case O_IP_SRC_MASK: 2574 case O_IP_DST_MASK: 2575 if (is_ipv4) { 2576 uint32_t a = 2577 (cmd->opcode == O_IP_DST_MASK) ? 2578 dst_ip.s_addr : src_ip.s_addr; 2579 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 2580 int i = cmdlen-1; 2581 2582 for (; !match && i>0; i-= 2, p+= 2) 2583 match = (p[0] == (a & p[1])); 2584 } 2585 break; 2586 2587 case O_IP_SRC_ME: 2588 if (is_ipv4) { 2589 struct ifnet *tif; 2590 2591 INADDR_TO_IFP(src_ip, tif); 2592 match = (tif != NULL); 2593 } 2594 break; 2595 2596 case O_IP_DST_SET: 2597 case O_IP_SRC_SET: 2598 if (is_ipv4) { 2599 u_int32_t *d = (u_int32_t *)(cmd+1); 2600 u_int32_t addr = 2601 cmd->opcode == O_IP_DST_SET ? 2602 args->f_id.dst_ip : 2603 args->f_id.src_ip; 2604 2605 if (addr < d[0]) 2606 break; 2607 addr -= d[0]; /* subtract base */ 2608 match = (addr < cmd->arg1) && 2609 ( d[ 1 + (addr>>5)] & 2610 (1<<(addr & 0x1f)) ); 2611 } 2612 break; 2613 2614 case O_IP_DST: 2615 match = is_ipv4 && 2616 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2617 dst_ip.s_addr); 2618 break; 2619 2620 case O_IP_DST_ME: 2621 if (is_ipv4) { 2622 struct ifnet *tif; 2623 2624 INADDR_TO_IFP(dst_ip, tif); 2625 match = (tif != NULL); 2626 } 2627 break; 2628 2629 case O_IP_SRCPORT: 2630 case O_IP_DSTPORT: 2631 /* 2632 * offset == 0 && proto != 0 is enough 2633 * to guarantee that we have a 2634 * packet with port info. 2635 */ 2636 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP) 2637 && offset == 0) { 2638 u_int16_t x = 2639 (cmd->opcode == O_IP_SRCPORT) ? 2640 src_port : dst_port ; 2641 u_int16_t *p = 2642 ((ipfw_insn_u16 *)cmd)->ports; 2643 int i; 2644 2645 for (i = cmdlen - 1; !match && i>0; 2646 i--, p += 2) 2647 match = (x>=p[0] && x<=p[1]); 2648 } 2649 break; 2650 2651 case O_ICMPTYPE: 2652 match = (offset == 0 && proto==IPPROTO_ICMP && 2653 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 2654 break; 2655 2656#ifdef INET6 2657 case O_ICMP6TYPE: 2658 match = is_ipv6 && offset == 0 && 2659 proto==IPPROTO_ICMPV6 && 2660 icmp6type_match( 2661 ICMP6(ulp)->icmp6_type, 2662 (ipfw_insn_u32 *)cmd); 2663 break; 2664#endif /* INET6 */ 2665 2666 case O_IPOPT: 2667 match = (is_ipv4 && 2668 ipopts_match(mtod(m, struct ip *), cmd) ); 2669 break; 2670 2671 case O_IPVER: 2672 match = (is_ipv4 && 2673 cmd->arg1 == mtod(m, struct ip *)->ip_v); 2674 break; 2675 2676 case O_IPID: 2677 case O_IPLEN: 2678 case O_IPTTL: 2679 if (is_ipv4) { /* only for IP packets */ 2680 uint16_t x; 2681 uint16_t *p; 2682 int i; 2683 2684 if (cmd->opcode == O_IPLEN) 2685 x = ip_len; 2686 else if (cmd->opcode == O_IPTTL) 2687 x = mtod(m, struct ip *)->ip_ttl; 2688 else /* must be IPID */ 2689 x = ntohs(mtod(m, struct ip *)->ip_id); 2690 if (cmdlen == 1) { 2691 match = (cmd->arg1 == x); 2692 break; 2693 } 2694 /* otherwise we have ranges */ 2695 p = ((ipfw_insn_u16 *)cmd)->ports; 2696 i = cmdlen - 1; 2697 for (; !match && i>0; i--, p += 2) 2698 match = (x >= p[0] && x <= p[1]); 2699 } 2700 break; 2701 2702 case O_IPPRECEDENCE: 2703 match = (is_ipv4 && 2704 (cmd->arg1 == (mtod(m, struct ip *)->ip_tos & 0xe0)) ); 2705 break; 2706 2707 case O_IPTOS: 2708 match = (is_ipv4 && 2709 flags_match(cmd, mtod(m, struct ip *)->ip_tos)); 2710 break; 2711 2712 case O_TCPDATALEN: 2713 if (proto == IPPROTO_TCP && offset == 0) { 2714 struct tcphdr *tcp; 2715 uint16_t x; 2716 uint16_t *p; 2717 int i; 2718 2719 tcp = TCP(ulp); 2720 x = ip_len - 2721 ((ip->ip_hl + tcp->th_off) << 2); 2722 if (cmdlen == 1) { 2723 match = (cmd->arg1 == x); 2724 break; 2725 } 2726 /* otherwise we have ranges */ 2727 p = ((ipfw_insn_u16 *)cmd)->ports; 2728 i = cmdlen - 1; 2729 for (; !match && i>0; i--, p += 2) 2730 match = (x >= p[0] && x <= p[1]); 2731 } 2732 break; 2733 2734 case O_TCPFLAGS: 2735 match = (proto == IPPROTO_TCP && offset == 0 && 2736 flags_match(cmd, TCP(ulp)->th_flags)); 2737 break; 2738 2739 case O_TCPOPTS: 2740 match = (proto == IPPROTO_TCP && offset == 0 && 2741 tcpopts_match(TCP(ulp), cmd)); 2742 break; 2743 2744 case O_TCPSEQ: 2745 match = (proto == IPPROTO_TCP && offset == 0 && 2746 ((ipfw_insn_u32 *)cmd)->d[0] == 2747 TCP(ulp)->th_seq); 2748 break; 2749 2750 case O_TCPACK: 2751 match = (proto == IPPROTO_TCP && offset == 0 && 2752 ((ipfw_insn_u32 *)cmd)->d[0] == 2753 TCP(ulp)->th_ack); 2754 break; 2755 2756 case O_TCPWIN: 2757 match = (proto == IPPROTO_TCP && offset == 0 && 2758 cmd->arg1 == TCP(ulp)->th_win); 2759 break; 2760 2761 case O_ESTAB: 2762 /* reject packets which have SYN only */ 2763 /* XXX should i also check for TH_ACK ? */ 2764 match = (proto == IPPROTO_TCP && offset == 0 && 2765 (TCP(ulp)->th_flags & 2766 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 2767 break; 2768 2769 case O_ALTQ: { 2770 struct altq_tag *at; 2771 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 2772 2773 match = 1; 2774 mtag = m_tag_find(m, PACKET_TAG_PF_QID, NULL); 2775 if (mtag != NULL) 2776 break; 2777 mtag = m_tag_get(PACKET_TAG_PF_QID, 2778 sizeof(struct altq_tag), 2779 M_NOWAIT); 2780 if (mtag == NULL) { 2781 /* 2782 * Let the packet fall back to the 2783 * default ALTQ. 2784 */ 2785 break; 2786 } 2787 at = (struct altq_tag *)(mtag+1); 2788 at->qid = altq->qid; 2789 if (is_ipv4) 2790 at->af = AF_INET; 2791 else 2792 at->af = AF_LINK; 2793 at->hdr = ip; 2794 m_tag_prepend(m, mtag); 2795 break; 2796 } 2797 2798 case O_LOG: 2799 if (fw_verbose) 2800 ipfw_log(f, hlen, args, m, oif, offset); 2801 match = 1; 2802 break; 2803 2804 case O_PROB: 2805 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 2806 break; 2807 2808 case O_VERREVPATH: 2809 /* Outgoing packets automatically pass/match */ 2810 match = ((oif != NULL) || 2811 (m->m_pkthdr.rcvif == NULL) || 2812 ( 2813#ifdef INET6 2814 is_ipv6 ? 2815 verify_path6(&(args->f_id.src_ip6), 2816 m->m_pkthdr.rcvif) : 2817#endif 2818 verify_path(src_ip, m->m_pkthdr.rcvif))); 2819 break; 2820 2821 case O_VERSRCREACH: 2822 /* Outgoing packets automatically pass/match */ 2823 match = (hlen > 0 && ((oif != NULL) || 2824#ifdef INET6 2825 is_ipv6 ? 2826 verify_path6(&(args->f_id.src_ip6), 2827 NULL) : 2828#endif 2829 verify_path(src_ip, NULL))); 2830 break; 2831 2832 case O_ANTISPOOF: 2833 /* Outgoing packets automatically pass/match */ 2834 if (oif == NULL && hlen > 0 && 2835 ( (is_ipv4 && in_localaddr(src_ip)) 2836#ifdef INET6 2837 || (is_ipv6 && 2838 in6_localaddr(&(args->f_id.src_ip6))) 2839#endif 2840 )) 2841 match = 2842#ifdef INET6 2843 is_ipv6 ? verify_path6( 2844 &(args->f_id.src_ip6), 2845 m->m_pkthdr.rcvif) : 2846#endif 2847 verify_path(src_ip, 2848 m->m_pkthdr.rcvif); 2849 else 2850 match = 1; 2851 break; 2852 2853 case O_IPSEC: 2854#ifdef FAST_IPSEC 2855 match = (m_tag_find(m, 2856 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 2857#endif 2858#ifdef IPSEC 2859 match = (ipsec_getnhist(m) != 0); 2860#endif 2861 /* otherwise no match */ 2862 break; 2863 2864#ifdef INET6 2865 case O_IP6_SRC: 2866 match = is_ipv6 && 2867 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 2868 &((ipfw_insn_ip6 *)cmd)->addr6); 2869 break; 2870 2871 case O_IP6_DST: 2872 match = is_ipv6 && 2873 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 2874 &((ipfw_insn_ip6 *)cmd)->addr6); 2875 break; 2876 case O_IP6_SRC_MASK: 2877 if (is_ipv6) { 2878 ipfw_insn_ip6 *te = (ipfw_insn_ip6 *)cmd; 2879 struct in6_addr p = args->f_id.src_ip6; 2880 2881 APPLY_MASK(&p, &te->mask6); 2882 match = IN6_ARE_ADDR_EQUAL(&te->addr6, &p); 2883 } 2884 break; 2885 2886 case O_IP6_DST_MASK: 2887 if (is_ipv6) { 2888 ipfw_insn_ip6 *te = (ipfw_insn_ip6 *)cmd; 2889 struct in6_addr p = args->f_id.dst_ip6; 2890 2891 APPLY_MASK(&p, &te->mask6); 2892 match = IN6_ARE_ADDR_EQUAL(&te->addr6, &p); 2893 } 2894 break; 2895 2896 case O_IP6_SRC_ME: 2897 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6); 2898 break; 2899 2900 case O_IP6_DST_ME: 2901 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6); 2902 break; 2903 2904 case O_FLOW6ID: 2905 match = is_ipv6 && 2906 flow6id_match(args->f_id.flow_id6, 2907 (ipfw_insn_u32 *) cmd); 2908 break; 2909 2910 case O_EXT_HDR: 2911 match = is_ipv6 && 2912 (ext_hd & ((ipfw_insn *) cmd)->arg1); 2913 break; 2914 2915 case O_IP6: 2916 match = is_ipv6; 2917 break; 2918#endif 2919 2920 case O_IP4: 2921 match = is_ipv4; 2922 break; 2923 2924 /* 2925 * The second set of opcodes represents 'actions', 2926 * i.e. the terminal part of a rule once the packet 2927 * matches all previous patterns. 2928 * Typically there is only one action for each rule, 2929 * and the opcode is stored at the end of the rule 2930 * (but there are exceptions -- see below). 2931 * 2932 * In general, here we set retval and terminate the 2933 * outer loop (would be a 'break 3' in some language, 2934 * but we need to do a 'goto done'). 2935 * 2936 * Exceptions: 2937 * O_COUNT and O_SKIPTO actions: 2938 * instead of terminating, we jump to the next rule 2939 * ('goto next_rule', equivalent to a 'break 2'), 2940 * or to the SKIPTO target ('goto again' after 2941 * having set f, cmd and l), respectively. 2942 * 2943 * O_LOG and O_ALTQ action parameters: 2944 * perform some action and set match = 1; 2945 * 2946 * O_LIMIT and O_KEEP_STATE: these opcodes are 2947 * not real 'actions', and are stored right 2948 * before the 'action' part of the rule. 2949 * These opcodes try to install an entry in the 2950 * state tables; if successful, we continue with 2951 * the next opcode (match=1; break;), otherwise 2952 * the packet * must be dropped 2953 * ('goto done' after setting retval); 2954 * 2955 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2956 * cause a lookup of the state table, and a jump 2957 * to the 'action' part of the parent rule 2958 * ('goto check_body') if an entry is found, or 2959 * (CHECK_STATE only) a jump to the next rule if 2960 * the entry is not found ('goto next_rule'). 2961 * The result of the lookup is cached to make 2962 * further instances of these opcodes are 2963 * effectively NOPs. 2964 */ 2965 case O_LIMIT: 2966 case O_KEEP_STATE: 2967 if (install_state(f, 2968 (ipfw_insn_limit *)cmd, args)) { 2969 retval = IP_FW_DENY; 2970 goto done; /* error/limit violation */ 2971 } 2972 match = 1; 2973 break; 2974 2975 case O_PROBE_STATE: 2976 case O_CHECK_STATE: 2977 /* 2978 * dynamic rules are checked at the first 2979 * keep-state or check-state occurrence, 2980 * with the result being stored in dyn_dir. 2981 * The compiler introduces a PROBE_STATE 2982 * instruction for us when we have a 2983 * KEEP_STATE (because PROBE_STATE needs 2984 * to be run first). 2985 */ 2986 if (dyn_dir == MATCH_UNKNOWN && 2987 (q = lookup_dyn_rule(&args->f_id, 2988 &dyn_dir, proto == IPPROTO_TCP ? 2989 TCP(ulp) : NULL)) 2990 != NULL) { 2991 /* 2992 * Found dynamic entry, update stats 2993 * and jump to the 'action' part of 2994 * the parent rule. 2995 */ 2996 q->pcnt++; 2997 q->bcnt += pktlen; 2998 f = q->rule; 2999 cmd = ACTION_PTR(f); 3000 l = f->cmd_len - f->act_ofs; 3001 IPFW_DYN_UNLOCK(); 3002 goto check_body; 3003 } 3004 /* 3005 * Dynamic entry not found. If CHECK_STATE, 3006 * skip to next rule, if PROBE_STATE just 3007 * ignore and continue with next opcode. 3008 */ 3009 if (cmd->opcode == O_CHECK_STATE) 3010 goto next_rule; 3011 match = 1; 3012 break; 3013 3014 case O_ACCEPT: 3015 retval = 0; /* accept */ 3016 goto done; 3017 3018 case O_PIPE: 3019 case O_QUEUE: 3020 args->rule = f; /* report matching rule */ 3021 args->cookie = cmd->arg1; 3022 retval = IP_FW_DUMMYNET; 3023 goto done; 3024 3025 case O_DIVERT: 3026 case O_TEE: { 3027 struct divert_tag *dt; 3028 3029 if (args->eh) /* not on layer 2 */ 3030 break; 3031 mtag = m_tag_get(PACKET_TAG_DIVERT, 3032 sizeof(struct divert_tag), 3033 M_NOWAIT); 3034 if (mtag == NULL) { 3035 /* XXX statistic */ 3036 /* drop packet */ 3037 IPFW_RUNLOCK(chain); 3038 return (IP_FW_DENY); 3039 } 3040 dt = (struct divert_tag *)(mtag+1); 3041 dt->cookie = f->rulenum; 3042 dt->info = cmd->arg1; 3043 m_tag_prepend(m, mtag); 3044 retval = (cmd->opcode == O_DIVERT) ? 3045 IP_FW_DIVERT : IP_FW_TEE; 3046 goto done; 3047 } 3048 3049 case O_COUNT: 3050 case O_SKIPTO: 3051 f->pcnt++; /* update stats */ 3052 f->bcnt += pktlen; 3053 f->timestamp = time_second; 3054 if (cmd->opcode == O_COUNT) 3055 goto next_rule; 3056 /* handle skipto */ 3057 if (f->next_rule == NULL) 3058 lookup_next_rule(f); 3059 f = f->next_rule; 3060 goto again; 3061 3062 case O_REJECT: 3063 /* 3064 * Drop the packet and send a reject notice 3065 * if the packet is not ICMP (or is an ICMP 3066 * query), and it is not multicast/broadcast. 3067 */ 3068 if (hlen > 0 && is_ipv4 && 3069 (proto != IPPROTO_ICMP || 3070 is_icmp_query(ICMP(ulp))) && 3071 !(m->m_flags & (M_BCAST|M_MCAST)) && 3072 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 3073 send_reject(args, cmd->arg1, 3074 offset,ip_len); 3075 m = args->m; 3076 } 3077 /* FALLTHROUGH */ 3078#ifdef INET6 3079 case O_UNREACH6: 3080 if (hlen > 0 && is_ipv6 && 3081 (proto != IPPROTO_ICMPV6 || 3082 (is_icmp6_query(args->f_id.flags) == 1)) && 3083 !(m->m_flags & (M_BCAST|M_MCAST)) && 3084 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 3085 send_reject6(args, cmd->arg1, 3086 offset, hlen); 3087 m = args->m; 3088 } 3089 /* FALLTHROUGH */ 3090#endif 3091 case O_DENY: 3092 retval = IP_FW_DENY; 3093 goto done; 3094 3095 case O_FORWARD_IP: 3096 if (args->eh) /* not valid on layer2 pkts */ 3097 break; 3098 if (!q || dyn_dir == MATCH_FORWARD) 3099 args->next_hop = 3100 &((ipfw_insn_sa *)cmd)->sa; 3101 retval = IP_FW_PASS; 3102 goto done; 3103 3104 case O_NETGRAPH: 3105 case O_NGTEE: 3106 args->rule = f; /* report matching rule */ 3107 args->cookie = cmd->arg1; 3108 retval = (cmd->opcode == O_NETGRAPH) ? 3109 IP_FW_NETGRAPH : IP_FW_NGTEE; 3110 goto done; 3111 3112 default: 3113 panic("-- unknown opcode %d\n", cmd->opcode); 3114 } /* end of switch() on opcodes */ 3115 3116 if (cmd->len & F_NOT) 3117 match = !match; 3118 3119 if (match) { 3120 if (cmd->len & F_OR) 3121 skip_or = 1; 3122 } else { 3123 if (!(cmd->len & F_OR)) /* not an OR block, */ 3124 break; /* try next rule */ 3125 } 3126 3127 } /* end of inner for, scan opcodes */ 3128 3129next_rule:; /* try next rule */ 3130 3131 } /* end of outer for, scan rules */ 3132 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 3133 IPFW_RUNLOCK(chain); 3134 return (IP_FW_DENY); 3135 3136done: 3137 /* Update statistics */ 3138 f->pcnt++; 3139 f->bcnt += pktlen; 3140 f->timestamp = time_second; 3141 IPFW_RUNLOCK(chain); 3142 return (retval); 3143 3144pullup_failed: 3145 if (fw_verbose) 3146 printf("ipfw: pullup failed\n"); 3147 return (IP_FW_DENY); 3148} 3149 3150/* 3151 * When a rule is added/deleted, clear the next_rule pointers in all rules. 3152 * These will be reconstructed on the fly as packets are matched. 3153 */ 3154static void 3155flush_rule_ptrs(struct ip_fw_chain *chain) 3156{ 3157 struct ip_fw *rule; 3158 3159 IPFW_WLOCK_ASSERT(chain); 3160 3161 for (rule = chain->rules; rule; rule = rule->next) 3162 rule->next_rule = NULL; 3163} 3164 3165/* 3166 * When pipes/queues are deleted, clear the "pipe_ptr" pointer to a given 3167 * pipe/queue, or to all of them (match == NULL). 3168 */ 3169void 3170flush_pipe_ptrs(struct dn_flow_set *match) 3171{ 3172 struct ip_fw *rule; 3173 3174 IPFW_WLOCK(&layer3_chain); 3175 for (rule = layer3_chain.rules; rule; rule = rule->next) { 3176 ipfw_insn_pipe *cmd = (ipfw_insn_pipe *)ACTION_PTR(rule); 3177 3178 if (cmd->o.opcode != O_PIPE && cmd->o.opcode != O_QUEUE) 3179 continue; 3180 /* 3181 * XXX Use bcmp/bzero to handle pipe_ptr to overcome 3182 * possible alignment problems on 64-bit architectures. 3183 * This code is seldom used so we do not worry too 3184 * much about efficiency. 3185 */ 3186 if (match == NULL || 3187 !bcmp(&cmd->pipe_ptr, &match, sizeof(match)) ) 3188 bzero(&cmd->pipe_ptr, sizeof(cmd->pipe_ptr)); 3189 } 3190 IPFW_WUNLOCK(&layer3_chain); 3191} 3192 3193/* 3194 * Add a new rule to the list. Copy the rule into a malloc'ed area, then 3195 * possibly create a rule number and add the rule to the list. 3196 * Update the rule_number in the input struct so the caller knows it as well. 3197 */ 3198static int 3199add_rule(struct ip_fw_chain *chain, struct ip_fw *input_rule) 3200{ 3201 struct ip_fw *rule, *f, *prev; 3202 int l = RULESIZE(input_rule); 3203 3204 if (chain->rules == NULL && input_rule->rulenum != IPFW_DEFAULT_RULE) 3205 return (EINVAL); 3206 3207 rule = malloc(l, M_IPFW, M_NOWAIT | M_ZERO); 3208 if (rule == NULL) 3209 return (ENOSPC); 3210 3211 bcopy(input_rule, rule, l); 3212 3213 rule->next = NULL; 3214 rule->next_rule = NULL; 3215 3216 rule->pcnt = 0; 3217 rule->bcnt = 0; 3218 rule->timestamp = 0; 3219 3220 IPFW_WLOCK(chain); 3221 3222 if (chain->rules == NULL) { /* default rule */ 3223 chain->rules = rule; 3224 goto done; 3225 } 3226 3227 /* 3228 * If rulenum is 0, find highest numbered rule before the 3229 * default rule, and add autoinc_step 3230 */ 3231 if (autoinc_step < 1) 3232 autoinc_step = 1; 3233 else if (autoinc_step > 1000) 3234 autoinc_step = 1000; 3235 if (rule->rulenum == 0) { 3236 /* 3237 * locate the highest numbered rule before default 3238 */ 3239 for (f = chain->rules; f; f = f->next) { 3240 if (f->rulenum == IPFW_DEFAULT_RULE) 3241 break; 3242 rule->rulenum = f->rulenum; 3243 } 3244 if (rule->rulenum < IPFW_DEFAULT_RULE - autoinc_step) 3245 rule->rulenum += autoinc_step; 3246 input_rule->rulenum = rule->rulenum; 3247 } 3248 3249 /* 3250 * Now insert the new rule in the right place in the sorted list. 3251 */ 3252 for (prev = NULL, f = chain->rules; f; prev = f, f = f->next) { 3253 if (f->rulenum > rule->rulenum) { /* found the location */ 3254 if (prev) { 3255 rule->next = f; 3256 prev->next = rule; 3257 } else { /* head insert */ 3258 rule->next = chain->rules; 3259 chain->rules = rule; 3260 } 3261 break; 3262 } 3263 } 3264 flush_rule_ptrs(chain); 3265done: 3266 static_count++; 3267 static_len += l; 3268 IPFW_WUNLOCK(chain); 3269 DEB(printf("ipfw: installed rule %d, static count now %d\n", 3270 rule->rulenum, static_count);) 3271 return (0); 3272} 3273 3274/** 3275 * Remove a static rule (including derived * dynamic rules) 3276 * and place it on the ``reap list'' for later reclamation. 3277 * The caller is in charge of clearing rule pointers to avoid 3278 * dangling pointers. 3279 * @return a pointer to the next entry. 3280 * Arguments are not checked, so they better be correct. 3281 */ 3282static struct ip_fw * 3283remove_rule(struct ip_fw_chain *chain, struct ip_fw *rule, struct ip_fw *prev) 3284{ 3285 struct ip_fw *n; 3286 int l = RULESIZE(rule); 3287 3288 IPFW_WLOCK_ASSERT(chain); 3289 3290 n = rule->next; 3291 IPFW_DYN_LOCK(); 3292 remove_dyn_rule(rule, NULL /* force removal */); 3293 IPFW_DYN_UNLOCK(); 3294 if (prev == NULL) 3295 chain->rules = n; 3296 else 3297 prev->next = n; 3298 static_count--; 3299 static_len -= l; 3300 3301 rule->next = chain->reap; 3302 chain->reap = rule; 3303 3304 return n; 3305} 3306 3307/** 3308 * Reclaim storage associated with a list of rules. This is 3309 * typically the list created using remove_rule. 3310 */ 3311static void 3312reap_rules(struct ip_fw *head) 3313{ 3314 struct ip_fw *rule; 3315 3316 while ((rule = head) != NULL) { 3317 head = head->next; 3318 if (DUMMYNET_LOADED) 3319 ip_dn_ruledel_ptr(rule); 3320 free(rule, M_IPFW); 3321 } 3322} 3323 3324/* 3325 * Remove all rules from a chain (except rules in set RESVD_SET 3326 * unless kill_default = 1). The caller is responsible for 3327 * reclaiming storage for the rules left in chain->reap. 3328 */ 3329static void 3330free_chain(struct ip_fw_chain *chain, int kill_default) 3331{ 3332 struct ip_fw *prev, *rule; 3333 3334 IPFW_WLOCK_ASSERT(chain); 3335 3336 flush_rule_ptrs(chain); /* more efficient to do outside the loop */ 3337 for (prev = NULL, rule = chain->rules; rule ; ) 3338 if (kill_default || rule->set != RESVD_SET) 3339 rule = remove_rule(chain, rule, prev); 3340 else { 3341 prev = rule; 3342 rule = rule->next; 3343 } 3344} 3345 3346/** 3347 * Remove all rules with given number, and also do set manipulation. 3348 * Assumes chain != NULL && *chain != NULL. 3349 * 3350 * The argument is an u_int32_t. The low 16 bit are the rule or set number, 3351 * the next 8 bits are the new set, the top 8 bits are the command: 3352 * 3353 * 0 delete rules with given number 3354 * 1 delete rules with given set number 3355 * 2 move rules with given number to new set 3356 * 3 move rules with given set number to new set 3357 * 4 swap sets with given numbers 3358 */ 3359static int 3360del_entry(struct ip_fw_chain *chain, u_int32_t arg) 3361{ 3362 struct ip_fw *prev = NULL, *rule; 3363 u_int16_t rulenum; /* rule or old_set */ 3364 u_int8_t cmd, new_set; 3365 3366 rulenum = arg & 0xffff; 3367 cmd = (arg >> 24) & 0xff; 3368 new_set = (arg >> 16) & 0xff; 3369 3370 if (cmd > 4) 3371 return EINVAL; 3372 if (new_set > RESVD_SET) 3373 return EINVAL; 3374 if (cmd == 0 || cmd == 2) { 3375 if (rulenum >= IPFW_DEFAULT_RULE) 3376 return EINVAL; 3377 } else { 3378 if (rulenum > RESVD_SET) /* old_set */ 3379 return EINVAL; 3380 } 3381 3382 IPFW_WLOCK(chain); 3383 rule = chain->rules; 3384 chain->reap = NULL; 3385 switch (cmd) { 3386 case 0: /* delete rules with given number */ 3387 /* 3388 * locate first rule to delete 3389 */ 3390 for (; rule->rulenum < rulenum; prev = rule, rule = rule->next) 3391 ; 3392 if (rule->rulenum != rulenum) { 3393 IPFW_WUNLOCK(chain); 3394 return EINVAL; 3395 } 3396 3397 /* 3398 * flush pointers outside the loop, then delete all matching 3399 * rules. prev remains the same throughout the cycle. 3400 */ 3401 flush_rule_ptrs(chain); 3402 while (rule->rulenum == rulenum) 3403 rule = remove_rule(chain, rule, prev); 3404 break; 3405 3406 case 1: /* delete all rules with given set number */ 3407 flush_rule_ptrs(chain); 3408 rule = chain->rules; 3409 while (rule->rulenum < IPFW_DEFAULT_RULE) 3410 if (rule->set == rulenum) 3411 rule = remove_rule(chain, rule, prev); 3412 else { 3413 prev = rule; 3414 rule = rule->next; 3415 } 3416 break; 3417 3418 case 2: /* move rules with given number to new set */ 3419 rule = chain->rules; 3420 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3421 if (rule->rulenum == rulenum) 3422 rule->set = new_set; 3423 break; 3424 3425 case 3: /* move rules with given set number to new set */ 3426 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3427 if (rule->set == rulenum) 3428 rule->set = new_set; 3429 break; 3430 3431 case 4: /* swap two sets */ 3432 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3433 if (rule->set == rulenum) 3434 rule->set = new_set; 3435 else if (rule->set == new_set) 3436 rule->set = rulenum; 3437 break; 3438 } 3439 /* 3440 * Look for rules to reclaim. We grab the list before 3441 * releasing the lock then reclaim them w/o the lock to 3442 * avoid a LOR with dummynet. 3443 */ 3444 rule = chain->reap; 3445 chain->reap = NULL; 3446 IPFW_WUNLOCK(chain); 3447 if (rule) 3448 reap_rules(rule); 3449 return 0; 3450} 3451 3452/* 3453 * Clear counters for a specific rule. 3454 * The enclosing "table" is assumed locked. 3455 */ 3456static void 3457clear_counters(struct ip_fw *rule, int log_only) 3458{ 3459 ipfw_insn_log *l = (ipfw_insn_log *)ACTION_PTR(rule); 3460 3461 if (log_only == 0) { 3462 rule->bcnt = rule->pcnt = 0; 3463 rule->timestamp = 0; 3464 } 3465 if (l->o.opcode == O_LOG) 3466 l->log_left = l->max_log; 3467} 3468 3469/** 3470 * Reset some or all counters on firewall rules. 3471 * @arg frwl is null to clear all entries, or contains a specific 3472 * rule number. 3473 * @arg log_only is 1 if we only want to reset logs, zero otherwise. 3474 */ 3475static int 3476zero_entry(struct ip_fw_chain *chain, int rulenum, int log_only) 3477{ 3478 struct ip_fw *rule; 3479 char *msg; 3480 3481 IPFW_WLOCK(chain); 3482 if (rulenum == 0) { 3483 norule_counter = 0; 3484 for (rule = chain->rules; rule; rule = rule->next) 3485 clear_counters(rule, log_only); 3486 msg = log_only ? "ipfw: All logging counts reset.\n" : 3487 "ipfw: Accounting cleared.\n"; 3488 } else { 3489 int cleared = 0; 3490 /* 3491 * We can have multiple rules with the same number, so we 3492 * need to clear them all. 3493 */ 3494 for (rule = chain->rules; rule; rule = rule->next) 3495 if (rule->rulenum == rulenum) { 3496 while (rule && rule->rulenum == rulenum) { 3497 clear_counters(rule, log_only); 3498 rule = rule->next; 3499 } 3500 cleared = 1; 3501 break; 3502 } 3503 if (!cleared) { /* we did not find any matching rules */ 3504 IPFW_WUNLOCK(chain); 3505 return (EINVAL); 3506 } 3507 msg = log_only ? "ipfw: Entry %d logging count reset.\n" : 3508 "ipfw: Entry %d cleared.\n"; 3509 } 3510 IPFW_WUNLOCK(chain); 3511 3512 if (fw_verbose) 3513 log(LOG_SECURITY | LOG_NOTICE, msg, rulenum); 3514 return (0); 3515} 3516 3517/* 3518 * Check validity of the structure before insert. 3519 * Fortunately rules are simple, so this mostly need to check rule sizes. 3520 */ 3521static int 3522check_ipfw_struct(struct ip_fw *rule, int size) 3523{ 3524 int l, cmdlen = 0; 3525 int have_action=0; 3526 ipfw_insn *cmd; 3527 3528 if (size < sizeof(*rule)) { 3529 printf("ipfw: rule too short\n"); 3530 return (EINVAL); 3531 } 3532 /* first, check for valid size */ 3533 l = RULESIZE(rule); 3534 if (l != size) { 3535 printf("ipfw: size mismatch (have %d want %d)\n", size, l); 3536 return (EINVAL); 3537 } 3538 if (rule->act_ofs >= rule->cmd_len) { 3539 printf("ipfw: bogus action offset (%u > %u)\n", 3540 rule->act_ofs, rule->cmd_len - 1); 3541 return (EINVAL); 3542 } 3543 /* 3544 * Now go for the individual checks. Very simple ones, basically only 3545 * instruction sizes. 3546 */ 3547 for (l = rule->cmd_len, cmd = rule->cmd ; 3548 l > 0 ; l -= cmdlen, cmd += cmdlen) { 3549 cmdlen = F_LEN(cmd); 3550 if (cmdlen > l) { 3551 printf("ipfw: opcode %d size truncated\n", 3552 cmd->opcode); 3553 return EINVAL; 3554 } 3555 DEB(printf("ipfw: opcode %d\n", cmd->opcode);) 3556 switch (cmd->opcode) { 3557 case O_PROBE_STATE: 3558 case O_KEEP_STATE: 3559 case O_PROTO: 3560 case O_IP_SRC_ME: 3561 case O_IP_DST_ME: 3562 case O_LAYER2: 3563 case O_IN: 3564 case O_FRAG: 3565 case O_DIVERTED: 3566 case O_IPOPT: 3567 case O_IPTOS: 3568 case O_IPPRECEDENCE: 3569 case O_IPVER: 3570 case O_TCPWIN: 3571 case O_TCPFLAGS: 3572 case O_TCPOPTS: 3573 case O_ESTAB: 3574 case O_VERREVPATH: 3575 case O_VERSRCREACH: 3576 case O_ANTISPOOF: 3577 case O_IPSEC: 3578#ifdef INET6 3579 case O_IP6_SRC_ME: 3580 case O_IP6_DST_ME: 3581 case O_EXT_HDR: 3582 case O_IP6: 3583#endif 3584 case O_IP4: 3585 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 3586 goto bad_size; 3587 break; 3588 3589 case O_UID: 3590 case O_GID: 3591 case O_JAIL: 3592 case O_IP_SRC: 3593 case O_IP_DST: 3594 case O_TCPSEQ: 3595 case O_TCPACK: 3596 case O_PROB: 3597 case O_ICMPTYPE: 3598 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32)) 3599 goto bad_size; 3600 break; 3601 3602 case O_LIMIT: 3603 if (cmdlen != F_INSN_SIZE(ipfw_insn_limit)) 3604 goto bad_size; 3605 break; 3606 3607 case O_LOG: 3608 if (cmdlen != F_INSN_SIZE(ipfw_insn_log)) 3609 goto bad_size; 3610 3611 ((ipfw_insn_log *)cmd)->log_left = 3612 ((ipfw_insn_log *)cmd)->max_log; 3613 3614 break; 3615 3616 case O_IP_SRC_MASK: 3617 case O_IP_DST_MASK: 3618 /* only odd command lengths */ 3619 if ( !(cmdlen & 1) || cmdlen > 31) 3620 goto bad_size; 3621 break; 3622 3623 case O_IP_SRC_SET: 3624 case O_IP_DST_SET: 3625 if (cmd->arg1 == 0 || cmd->arg1 > 256) { 3626 printf("ipfw: invalid set size %d\n", 3627 cmd->arg1); 3628 return EINVAL; 3629 } 3630 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) + 3631 (cmd->arg1+31)/32 ) 3632 goto bad_size; 3633 break; 3634 3635 case O_IP_SRC_LOOKUP: 3636 case O_IP_DST_LOOKUP: 3637 if (cmd->arg1 >= IPFW_TABLES_MAX) { 3638 printf("ipfw: invalid table number %d\n", 3639 cmd->arg1); 3640 return (EINVAL); 3641 } 3642 if (cmdlen != F_INSN_SIZE(ipfw_insn) && 3643 cmdlen != F_INSN_SIZE(ipfw_insn_u32)) 3644 goto bad_size; 3645 break; 3646 3647 case O_MACADDR2: 3648 if (cmdlen != F_INSN_SIZE(ipfw_insn_mac)) 3649 goto bad_size; 3650 break; 3651 3652 case O_NOP: 3653 case O_IPID: 3654 case O_IPTTL: 3655 case O_IPLEN: 3656 case O_TCPDATALEN: 3657 if (cmdlen < 1 || cmdlen > 31) 3658 goto bad_size; 3659 break; 3660 3661 case O_MAC_TYPE: 3662 case O_IP_SRCPORT: 3663 case O_IP_DSTPORT: /* XXX artificial limit, 30 port pairs */ 3664 if (cmdlen < 2 || cmdlen > 31) 3665 goto bad_size; 3666 break; 3667 3668 case O_RECV: 3669 case O_XMIT: 3670 case O_VIA: 3671 if (cmdlen != F_INSN_SIZE(ipfw_insn_if)) 3672 goto bad_size; 3673 break; 3674 3675 case O_ALTQ: 3676 if (cmdlen != F_INSN_SIZE(ipfw_insn_altq)) 3677 goto bad_size; 3678 break; 3679 3680 case O_PIPE: 3681 case O_QUEUE: 3682 if (cmdlen != F_INSN_SIZE(ipfw_insn_pipe)) 3683 goto bad_size; 3684 goto check_action; 3685 3686 case O_FORWARD_IP: 3687#ifdef IPFIREWALL_FORWARD 3688 if (cmdlen != F_INSN_SIZE(ipfw_insn_sa)) 3689 goto bad_size; 3690 goto check_action; 3691#else 3692 return EINVAL; 3693#endif 3694 3695 case O_DIVERT: 3696 case O_TEE: 3697 if (ip_divert_ptr == NULL) 3698 return EINVAL; 3699 else 3700 goto check_size; 3701 case O_NETGRAPH: 3702 case O_NGTEE: 3703 if (!NG_IPFW_LOADED) 3704 return EINVAL; 3705 else 3706 goto check_size; 3707 case O_FORWARD_MAC: /* XXX not implemented yet */ 3708 case O_CHECK_STATE: 3709 case O_COUNT: 3710 case O_ACCEPT: 3711 case O_DENY: 3712 case O_REJECT: 3713#ifdef INET6 3714 case O_UNREACH6: 3715#endif 3716 case O_SKIPTO: 3717check_size: 3718 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 3719 goto bad_size; 3720check_action: 3721 if (have_action) { 3722 printf("ipfw: opcode %d, multiple actions" 3723 " not allowed\n", 3724 cmd->opcode); 3725 return EINVAL; 3726 } 3727 have_action = 1; 3728 if (l != cmdlen) { 3729 printf("ipfw: opcode %d, action must be" 3730 " last opcode\n", 3731 cmd->opcode); 3732 return EINVAL; 3733 } 3734 break; 3735#ifdef INET6 3736 case O_IP6_SRC: 3737 case O_IP6_DST: 3738 if (cmdlen != F_INSN_SIZE(struct in6_addr) + 3739 F_INSN_SIZE(ipfw_insn)) 3740 goto bad_size; 3741 break; 3742 3743 case O_FLOW6ID: 3744 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) + 3745 ((ipfw_insn_u32 *)cmd)->o.arg1) 3746 goto bad_size; 3747 break; 3748 3749 case O_IP6_SRC_MASK: 3750 case O_IP6_DST_MASK: 3751 if ( !(cmdlen & 1) || cmdlen > 127) 3752 goto bad_size; 3753 break; 3754 case O_ICMP6TYPE: 3755 if( cmdlen != F_INSN_SIZE( ipfw_insn_icmp6 ) ) 3756 goto bad_size; 3757 break; 3758#endif 3759 3760 default: 3761 switch (cmd->opcode) { 3762#ifndef INET6 3763 case O_IP6_SRC_ME: 3764 case O_IP6_DST_ME: 3765 case O_EXT_HDR: 3766 case O_IP6: 3767 case O_UNREACH6: 3768 case O_IP6_SRC: 3769 case O_IP6_DST: 3770 case O_FLOW6ID: 3771 case O_IP6_SRC_MASK: 3772 case O_IP6_DST_MASK: 3773 case O_ICMP6TYPE: 3774 printf("ipfw: no IPv6 support in kernel\n"); 3775 return EPROTONOSUPPORT; 3776#endif 3777 default: 3778 printf("ipfw: opcode %d, unknown opcode\n", 3779 cmd->opcode); 3780 return EINVAL; 3781 } 3782 } 3783 } 3784 if (have_action == 0) { 3785 printf("ipfw: missing action\n"); 3786 return EINVAL; 3787 } 3788 return 0; 3789 3790bad_size: 3791 printf("ipfw: opcode %d size %d wrong\n", 3792 cmd->opcode, cmdlen); 3793 return EINVAL; 3794} 3795 3796/* 3797 * Copy the static and dynamic rules to the supplied buffer 3798 * and return the amount of space actually used. 3799 */ 3800static size_t 3801ipfw_getrules(struct ip_fw_chain *chain, void *buf, size_t space) 3802{ 3803 char *bp = buf; 3804 char *ep = bp + space; 3805 struct ip_fw *rule; 3806 int i; 3807 3808 /* XXX this can take a long time and locking will block packet flow */ 3809 IPFW_RLOCK(chain); 3810 for (rule = chain->rules; rule ; rule = rule->next) { 3811 /* 3812 * Verify the entry fits in the buffer in case the 3813 * rules changed between calculating buffer space and 3814 * now. This would be better done using a generation 3815 * number but should suffice for now. 3816 */ 3817 i = RULESIZE(rule); 3818 if (bp + i <= ep) { 3819 bcopy(rule, bp, i); 3820 bcopy(&set_disable, &(((struct ip_fw *)bp)->next_rule), 3821 sizeof(set_disable)); 3822 bp += i; 3823 } 3824 } 3825 IPFW_RUNLOCK(chain); 3826 if (ipfw_dyn_v) { 3827 ipfw_dyn_rule *p, *last = NULL; 3828 3829 IPFW_DYN_LOCK(); 3830 for (i = 0 ; i < curr_dyn_buckets; i++) 3831 for (p = ipfw_dyn_v[i] ; p != NULL; p = p->next) { 3832 if (bp + sizeof *p <= ep) { 3833 ipfw_dyn_rule *dst = 3834 (ipfw_dyn_rule *)bp; 3835 bcopy(p, dst, sizeof *p); 3836 bcopy(&(p->rule->rulenum), &(dst->rule), 3837 sizeof(p->rule->rulenum)); 3838 /* 3839 * store a non-null value in "next". 3840 * The userland code will interpret a 3841 * NULL here as a marker 3842 * for the last dynamic rule. 3843 */ 3844 bcopy(&dst, &dst->next, sizeof(dst)); 3845 last = dst; 3846 dst->expire = 3847 TIME_LEQ(dst->expire, time_second) ? 3848 0 : dst->expire - time_second ; 3849 bp += sizeof(ipfw_dyn_rule); 3850 } 3851 } 3852 IPFW_DYN_UNLOCK(); 3853 if (last != NULL) /* mark last dynamic rule */ 3854 bzero(&last->next, sizeof(last)); 3855 } 3856 return (bp - (char *)buf); 3857} 3858 3859 3860/** 3861 * {set|get}sockopt parser. 3862 */ 3863static int 3864ipfw_ctl(struct sockopt *sopt) 3865{ 3866#define RULE_MAXSIZE (256*sizeof(u_int32_t)) 3867 int error, rule_num; 3868 size_t size; 3869 struct ip_fw *buf, *rule; 3870 u_int32_t rulenum[2]; 3871 3872 error = suser(sopt->sopt_td); 3873 if (error) 3874 return (error); 3875 3876 /* 3877 * Disallow modifications in really-really secure mode, but still allow 3878 * the logging counters to be reset. 3879 */ 3880 if (sopt->sopt_name == IP_FW_ADD || 3881 (sopt->sopt_dir == SOPT_SET && sopt->sopt_name != IP_FW_RESETLOG)) { 3882#if __FreeBSD_version >= 500034 3883 error = securelevel_ge(sopt->sopt_td->td_ucred, 3); 3884 if (error) 3885 return (error); 3886#else /* FreeBSD 4.x */ 3887 if (securelevel >= 3) 3888 return (EPERM); 3889#endif 3890 } 3891 3892 error = 0; 3893 3894 switch (sopt->sopt_name) { 3895 case IP_FW_GET: 3896 /* 3897 * pass up a copy of the current rules. Static rules 3898 * come first (the last of which has number IPFW_DEFAULT_RULE), 3899 * followed by a possibly empty list of dynamic rule. 3900 * The last dynamic rule has NULL in the "next" field. 3901 * 3902 * Note that the calculated size is used to bound the 3903 * amount of data returned to the user. The rule set may 3904 * change between calculating the size and returning the 3905 * data in which case we'll just return what fits. 3906 */ 3907 size = static_len; /* size of static rules */ 3908 if (ipfw_dyn_v) /* add size of dyn.rules */ 3909 size += (dyn_count * sizeof(ipfw_dyn_rule)); 3910 3911 /* 3912 * XXX todo: if the user passes a short length just to know 3913 * how much room is needed, do not bother filling up the 3914 * buffer, just jump to the sooptcopyout. 3915 */ 3916 buf = malloc(size, M_TEMP, M_WAITOK); 3917 error = sooptcopyout(sopt, buf, 3918 ipfw_getrules(&layer3_chain, buf, size)); 3919 free(buf, M_TEMP); 3920 break; 3921 3922 case IP_FW_FLUSH: 3923 /* 3924 * Normally we cannot release the lock on each iteration. 3925 * We could do it here only because we start from the head all 3926 * the times so there is no risk of missing some entries. 3927 * On the other hand, the risk is that we end up with 3928 * a very inconsistent ruleset, so better keep the lock 3929 * around the whole cycle. 3930 * 3931 * XXX this code can be improved by resetting the head of 3932 * the list to point to the default rule, and then freeing 3933 * the old list without the need for a lock. 3934 */ 3935 3936 IPFW_WLOCK(&layer3_chain); 3937 layer3_chain.reap = NULL; 3938 free_chain(&layer3_chain, 0 /* keep default rule */); 3939 rule = layer3_chain.reap, layer3_chain.reap = NULL; 3940 IPFW_WUNLOCK(&layer3_chain); 3941 if (layer3_chain.reap != NULL) 3942 reap_rules(rule); 3943 break; 3944 3945 case IP_FW_ADD: 3946 rule = malloc(RULE_MAXSIZE, M_TEMP, M_WAITOK); 3947 error = sooptcopyin(sopt, rule, RULE_MAXSIZE, 3948 sizeof(struct ip_fw) ); 3949 if (error == 0) 3950 error = check_ipfw_struct(rule, sopt->sopt_valsize); 3951 if (error == 0) { 3952 error = add_rule(&layer3_chain, rule); 3953 size = RULESIZE(rule); 3954 if (!error && sopt->sopt_dir == SOPT_GET) 3955 error = sooptcopyout(sopt, rule, size); 3956 } 3957 free(rule, M_TEMP); 3958 break; 3959 3960 case IP_FW_DEL: 3961 /* 3962 * IP_FW_DEL is used for deleting single rules or sets, 3963 * and (ab)used to atomically manipulate sets. Argument size 3964 * is used to distinguish between the two: 3965 * sizeof(u_int32_t) 3966 * delete single rule or set of rules, 3967 * or reassign rules (or sets) to a different set. 3968 * 2*sizeof(u_int32_t) 3969 * atomic disable/enable sets. 3970 * first u_int32_t contains sets to be disabled, 3971 * second u_int32_t contains sets to be enabled. 3972 */ 3973 error = sooptcopyin(sopt, rulenum, 3974 2*sizeof(u_int32_t), sizeof(u_int32_t)); 3975 if (error) 3976 break; 3977 size = sopt->sopt_valsize; 3978 if (size == sizeof(u_int32_t)) /* delete or reassign */ 3979 error = del_entry(&layer3_chain, rulenum[0]); 3980 else if (size == 2*sizeof(u_int32_t)) /* set enable/disable */ 3981 set_disable = 3982 (set_disable | rulenum[0]) & ~rulenum[1] & 3983 ~(1<<RESVD_SET); /* set RESVD_SET always enabled */ 3984 else 3985 error = EINVAL; 3986 break; 3987 3988 case IP_FW_ZERO: 3989 case IP_FW_RESETLOG: /* argument is an int, the rule number */ 3990 rule_num = 0; 3991 if (sopt->sopt_val != 0) { 3992 error = sooptcopyin(sopt, &rule_num, 3993 sizeof(int), sizeof(int)); 3994 if (error) 3995 break; 3996 } 3997 error = zero_entry(&layer3_chain, rule_num, 3998 sopt->sopt_name == IP_FW_RESETLOG); 3999 break; 4000 4001 case IP_FW_TABLE_ADD: 4002 { 4003 ipfw_table_entry ent; 4004 4005 error = sooptcopyin(sopt, &ent, 4006 sizeof(ent), sizeof(ent)); 4007 if (error) 4008 break; 4009 error = add_table_entry(ent.tbl, ent.addr, 4010 ent.masklen, ent.value); 4011 } 4012 break; 4013 4014 case IP_FW_TABLE_DEL: 4015 { 4016 ipfw_table_entry ent; 4017 4018 error = sooptcopyin(sopt, &ent, 4019 sizeof(ent), sizeof(ent)); 4020 if (error) 4021 break; 4022 error = del_table_entry(ent.tbl, ent.addr, ent.masklen); 4023 } 4024 break; 4025 4026 case IP_FW_TABLE_FLUSH: 4027 { 4028 u_int16_t tbl; 4029 4030 error = sooptcopyin(sopt, &tbl, 4031 sizeof(tbl), sizeof(tbl)); 4032 if (error) 4033 break; 4034 error = flush_table(tbl); 4035 } 4036 break; 4037 4038 case IP_FW_TABLE_GETSIZE: 4039 { 4040 u_int32_t tbl, cnt; 4041 4042 if ((error = sooptcopyin(sopt, &tbl, sizeof(tbl), 4043 sizeof(tbl)))) 4044 break; 4045 if ((error = count_table(tbl, &cnt))) 4046 break; 4047 error = sooptcopyout(sopt, &cnt, sizeof(cnt)); 4048 } 4049 break; 4050 4051 case IP_FW_TABLE_LIST: 4052 { 4053 ipfw_table *tbl; 4054 4055 if (sopt->sopt_valsize < sizeof(*tbl)) { 4056 error = EINVAL; 4057 break; 4058 } 4059 size = sopt->sopt_valsize; 4060 tbl = malloc(size, M_TEMP, M_WAITOK); 4061 if (tbl == NULL) { 4062 error = ENOMEM; 4063 break; 4064 } 4065 error = sooptcopyin(sopt, tbl, size, sizeof(*tbl)); 4066 if (error) { 4067 free(tbl, M_TEMP); 4068 break; 4069 } 4070 tbl->size = (size - sizeof(*tbl)) / 4071 sizeof(ipfw_table_entry); 4072 error = dump_table(tbl); 4073 if (error) { 4074 free(tbl, M_TEMP); 4075 break; 4076 } 4077 error = sooptcopyout(sopt, tbl, size); 4078 free(tbl, M_TEMP); 4079 } 4080 break; 4081 4082 default: 4083 printf("ipfw: ipfw_ctl invalid option %d\n", sopt->sopt_name); 4084 error = EINVAL; 4085 } 4086 4087 return (error); 4088#undef RULE_MAXSIZE 4089} 4090 4091/** 4092 * dummynet needs a reference to the default rule, because rules can be 4093 * deleted while packets hold a reference to them. When this happens, 4094 * dummynet changes the reference to the default rule (it could well be a 4095 * NULL pointer, but this way we do not need to check for the special 4096 * case, plus here he have info on the default behaviour). 4097 */ 4098struct ip_fw *ip_fw_default_rule; 4099 4100/* 4101 * This procedure is only used to handle keepalives. It is invoked 4102 * every dyn_keepalive_period 4103 */ 4104static void 4105ipfw_tick(void * __unused unused) 4106{ 4107 struct mbuf *m0, *m, *mnext, **mtailp; 4108 int i; 4109 ipfw_dyn_rule *q; 4110 4111 if (dyn_keepalive == 0 || ipfw_dyn_v == NULL || dyn_count == 0) 4112 goto done; 4113 4114 /* 4115 * We make a chain of packets to go out here -- not deferring 4116 * until after we drop the IPFW dynamic rule lock would result 4117 * in a lock order reversal with the normal packet input -> ipfw 4118 * call stack. 4119 */ 4120 m0 = NULL; 4121 mtailp = &m0; 4122 IPFW_DYN_LOCK(); 4123 for (i = 0 ; i < curr_dyn_buckets ; i++) { 4124 for (q = ipfw_dyn_v[i] ; q ; q = q->next ) { 4125 if (q->dyn_type == O_LIMIT_PARENT) 4126 continue; 4127 if (q->id.proto != IPPROTO_TCP) 4128 continue; 4129 if ( (q->state & BOTH_SYN) != BOTH_SYN) 4130 continue; 4131 if (TIME_LEQ( time_second+dyn_keepalive_interval, 4132 q->expire)) 4133 continue; /* too early */ 4134 if (TIME_LEQ(q->expire, time_second)) 4135 continue; /* too late, rule expired */ 4136 4137 *mtailp = send_pkt(&(q->id), q->ack_rev - 1, 4138 q->ack_fwd, TH_SYN); 4139 if (*mtailp != NULL) 4140 mtailp = &(*mtailp)->m_nextpkt; 4141 *mtailp = send_pkt(&(q->id), q->ack_fwd - 1, 4142 q->ack_rev, 0); 4143 if (*mtailp != NULL) 4144 mtailp = &(*mtailp)->m_nextpkt; 4145 } 4146 } 4147 IPFW_DYN_UNLOCK(); 4148 for (m = mnext = m0; m != NULL; m = mnext) { 4149 mnext = m->m_nextpkt; 4150 m->m_nextpkt = NULL; 4151 ip_output(m, NULL, NULL, 0, NULL, NULL); 4152 } 4153done: 4154 callout_reset(&ipfw_timeout, dyn_keepalive_period*hz, ipfw_tick, NULL); 4155} 4156 4157int 4158ipfw_init(void) 4159{ 4160 struct ip_fw default_rule; 4161 int error; 4162 4163#ifdef INET6 4164 /* Setup IPv6 fw sysctl tree. */ 4165 sysctl_ctx_init(&ip6_fw_sysctl_ctx); 4166 ip6_fw_sysctl_tree = SYSCTL_ADD_NODE(&ip6_fw_sysctl_ctx, 4167 SYSCTL_STATIC_CHILDREN(_net_inet6_ip6), OID_AUTO, "fw", 4168 CTLFLAG_RW | CTLFLAG_SECURE, 0, "Firewall"); 4169 SYSCTL_ADD_INT(&ip6_fw_sysctl_ctx, SYSCTL_CHILDREN(ip6_fw_sysctl_tree), 4170 OID_AUTO, "deny_unknown_exthdrs", CTLFLAG_RW | CTLFLAG_SECURE, 4171 &fw_deny_unknown_exthdrs, 0, 4172 "Deny packets with unknown IPv6 Extension Headers"); 4173#endif 4174 4175 layer3_chain.rules = NULL; 4176 layer3_chain.want_write = 0; 4177 layer3_chain.busy_count = 0; 4178 cv_init(&layer3_chain.cv, "Condition variable for IPFW rw locks"); 4179 IPFW_LOCK_INIT(&layer3_chain); 4180 ipfw_dyn_rule_zone = uma_zcreate("IPFW dynamic rule zone", 4181 sizeof(ipfw_dyn_rule), NULL, NULL, NULL, NULL, 4182 UMA_ALIGN_PTR, 0); 4183 IPFW_DYN_LOCK_INIT(); 4184 callout_init(&ipfw_timeout, NET_CALLOUT_MPSAFE); 4185 4186 bzero(&default_rule, sizeof default_rule); 4187 4188 default_rule.act_ofs = 0; 4189 default_rule.rulenum = IPFW_DEFAULT_RULE; 4190 default_rule.cmd_len = 1; 4191 default_rule.set = RESVD_SET; 4192 4193 default_rule.cmd[0].len = 1; 4194 default_rule.cmd[0].opcode = 4195#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 4196 1 ? O_ACCEPT : 4197#endif 4198 O_DENY; 4199 4200 error = add_rule(&layer3_chain, &default_rule); 4201 if (error != 0) { 4202 printf("ipfw2: error %u initializing default rule " 4203 "(support disabled)\n", error); 4204 IPFW_DYN_LOCK_DESTROY(); 4205 IPFW_LOCK_DESTROY(&layer3_chain); 4206 return (error); 4207 } 4208 4209 ip_fw_default_rule = layer3_chain.rules; 4210 printf("ipfw2 (+ipv6) initialized, divert %s, " 4211 "rule-based forwarding " 4212#ifdef IPFIREWALL_FORWARD 4213 "enabled, " 4214#else 4215 "disabled, " 4216#endif 4217 "default to %s, logging ", 4218#ifdef IPDIVERT 4219 "enabled", 4220#else 4221 "loadable", 4222#endif 4223 default_rule.cmd[0].opcode == O_ACCEPT ? "accept" : "deny"); 4224 4225#ifdef IPFIREWALL_VERBOSE 4226 fw_verbose = 1; 4227#endif 4228#ifdef IPFIREWALL_VERBOSE_LIMIT 4229 verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 4230#endif 4231 if (fw_verbose == 0) 4232 printf("disabled\n"); 4233 else if (verbose_limit == 0) 4234 printf("unlimited\n"); 4235 else 4236 printf("limited to %d packets/entry by default\n", 4237 verbose_limit); 4238 4239 init_tables(); 4240 ip_fw_ctl_ptr = ipfw_ctl; 4241 ip_fw_chk_ptr = ipfw_chk; 4242 callout_reset(&ipfw_timeout, hz, ipfw_tick, NULL); 4243 4244 return (0); 4245} 4246 4247void 4248ipfw_destroy(void) 4249{ 4250 struct ip_fw *reap; 4251 4252 ip_fw_chk_ptr = NULL; 4253 ip_fw_ctl_ptr = NULL; 4254 callout_drain(&ipfw_timeout); 4255 IPFW_WLOCK(&layer3_chain); 4256 layer3_chain.reap = NULL; 4257 free_chain(&layer3_chain, 1 /* kill default rule */); 4258 reap = layer3_chain.reap, layer3_chain.reap = NULL; 4259 IPFW_WUNLOCK(&layer3_chain); 4260 if (reap != NULL) 4261 reap_rules(reap); 4262 flush_tables(); 4263 IPFW_DYN_LOCK_DESTROY(); 4264 uma_zdestroy(ipfw_dyn_rule_zone); 4265 IPFW_LOCK_DESTROY(&layer3_chain); 4266 4267#ifdef INET6 4268 /* Free IPv6 fw sysctl tree. */ 4269 sysctl_ctx_free(&ip6_fw_sysctl_ctx); 4270#endif 4271 4272 printf("IP firewall unloaded\n"); 4273} 4274