ip_fw2.c revision 169245
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 169245 2007-05-04 11:15:41Z 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_ipdivert.h" 38#include "opt_ipdn.h" 39#include "opt_inet.h" 40#ifndef INET 41#error IPFIREWALL requires INET. 42#endif /* INET */ 43#endif 44#include "opt_inet6.h" 45#include "opt_ipsec.h" 46#include "opt_mac.h" 47 48#include <sys/param.h> 49#include <sys/systm.h> 50#include <sys/condvar.h> 51#include <sys/eventhandler.h> 52#include <sys/malloc.h> 53#include <sys/mbuf.h> 54#include <sys/kernel.h> 55#include <sys/lock.h> 56#include <sys/jail.h> 57#include <sys/module.h> 58#include <sys/priv.h> 59#include <sys/proc.h> 60#include <sys/rwlock.h> 61#include <sys/socket.h> 62#include <sys/socketvar.h> 63#include <sys/sysctl.h> 64#include <sys/syslog.h> 65#include <sys/ucred.h> 66#include <net/if.h> 67#include <net/radix.h> 68#include <net/route.h> 69#include <netinet/in.h> 70#include <netinet/in_systm.h> 71#include <netinet/in_var.h> 72#include <netinet/in_pcb.h> 73#include <netinet/ip.h> 74#include <netinet/ip_var.h> 75#include <netinet/ip_icmp.h> 76#include <netinet/ip_fw.h> 77#include <netinet/ip_divert.h> 78#include <netinet/ip_dummynet.h> 79#include <netinet/ip_carp.h> 80#include <netinet/pim.h> 81#include <netinet/tcp.h> 82#include <netinet/tcp_timer.h> 83#include <netinet/tcp_var.h> 84#include <netinet/tcpip.h> 85#include <netinet/udp.h> 86#include <netinet/udp_var.h> 87#include <netinet/sctp.h> 88#ifdef IPFIREWALL_NAT 89#include <netinet/libalias/alias.h> 90#include <netinet/libalias/alias_local.h> 91#endif 92#include <netgraph/ng_ipfw.h> 93 94#include <altq/if_altq.h> 95 96#ifdef IPSEC 97#include <netinet6/ipsec.h> 98#endif 99 100#include <netinet/ip6.h> 101#include <netinet/icmp6.h> 102#ifdef INET6 103#include <netinet6/scope6_var.h> 104#endif 105 106#include <netinet/if_ether.h> /* XXX for ETHERTYPE_IP */ 107 108#include <machine/in_cksum.h> /* XXX for in_cksum */ 109 110#include <security/mac/mac_framework.h> 111 112/* 113 * set_disable contains one bit per set value (0..31). 114 * If the bit is set, all rules with the corresponding set 115 * are disabled. Set RESVD_SET(31) is reserved for the default rule 116 * and rules that are not deleted by the flush command, 117 * and CANNOT be disabled. 118 * Rules in set RESVD_SET can only be deleted explicitly. 119 */ 120static u_int32_t set_disable; 121 122static int fw_verbose; 123static int verbose_limit; 124 125static struct callout ipfw_timeout; 126static uma_zone_t ipfw_dyn_rule_zone; 127#define IPFW_DEFAULT_RULE 65535 128 129/* 130 * Data structure to cache our ucred related 131 * information. This structure only gets used if 132 * the user specified UID/GID based constraints in 133 * a firewall rule. 134 */ 135struct ip_fw_ugid { 136 gid_t fw_groups[NGROUPS]; 137 int fw_ngroups; 138 uid_t fw_uid; 139 int fw_prid; 140}; 141 142#define IPFW_TABLES_MAX 128 143struct ip_fw_chain { 144 struct ip_fw *rules; /* list of rules */ 145 struct ip_fw *reap; /* list of rules to reap */ 146 LIST_HEAD(, cfg_nat) nat; /* list of nat entries */ 147 struct radix_node_head *tables[IPFW_TABLES_MAX]; 148 struct rwlock rwmtx; 149}; 150#define IPFW_LOCK_INIT(_chain) \ 151 rw_init(&(_chain)->rwmtx, "IPFW static rules") 152#define IPFW_LOCK_DESTROY(_chain) rw_destroy(&(_chain)->rwmtx) 153#define IPFW_WLOCK_ASSERT(_chain) do { \ 154 rw_assert(&(_chain)->rwmtx, RA_WLOCKED); \ 155 NET_ASSERT_GIANT(); \ 156} while (0) 157 158#define IPFW_RLOCK(p) rw_rlock(&(p)->rwmtx) 159#define IPFW_RUNLOCK(p) rw_runlock(&(p)->rwmtx) 160#define IPFW_WLOCK(p) rw_wlock(&(p)->rwmtx) 161#define IPFW_WUNLOCK(p) rw_wunlock(&(p)->rwmtx) 162 163/* 164 * list of rules for layer 3 165 */ 166static struct ip_fw_chain layer3_chain; 167 168MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's"); 169MALLOC_DEFINE(M_IPFW_TBL, "ipfw_tbl", "IpFw tables"); 170 171struct table_entry { 172 struct radix_node rn[2]; 173 struct sockaddr_in addr, mask; 174 u_int32_t value; 175}; 176 177static int fw_debug = 1; 178static int autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 179 180extern int ipfw_chg_hook(SYSCTL_HANDLER_ARGS); 181 182#ifdef SYSCTL_NODE 183SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 184SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, enable, 185 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3, &fw_enable, 0, 186 ipfw_chg_hook, "I", "Enable ipfw"); 187SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, CTLFLAG_RW, 188 &autoinc_step, 0, "Rule number autincrement step"); 189SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 190 CTLFLAG_RW | CTLFLAG_SECURE3, 191 &fw_one_pass, 0, 192 "Only do a single pass through ipfw when using dummynet(4)"); 193SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW, 194 &fw_debug, 0, "Enable printing of debug ip_fw statements"); 195SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, 196 CTLFLAG_RW | CTLFLAG_SECURE3, 197 &fw_verbose, 0, "Log matches to ipfw rules"); 198SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, 199 &verbose_limit, 0, "Set upper limit of matches of ipfw rules logged"); 200 201/* 202 * Description of dynamic rules. 203 * 204 * Dynamic rules are stored in lists accessed through a hash table 205 * (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can 206 * be modified through the sysctl variable dyn_buckets which is 207 * updated when the table becomes empty. 208 * 209 * XXX currently there is only one list, ipfw_dyn. 210 * 211 * When a packet is received, its address fields are first masked 212 * with the mask defined for the rule, then hashed, then matched 213 * against the entries in the corresponding list. 214 * Dynamic rules can be used for different purposes: 215 * + stateful rules; 216 * + enforcing limits on the number of sessions; 217 * + in-kernel NAT (not implemented yet) 218 * 219 * The lifetime of dynamic rules is regulated by dyn_*_lifetime, 220 * measured in seconds and depending on the flags. 221 * 222 * The total number of dynamic rules is stored in dyn_count. 223 * The max number of dynamic rules is dyn_max. When we reach 224 * the maximum number of rules we do not create anymore. This is 225 * done to avoid consuming too much memory, but also too much 226 * time when searching on each packet (ideally, we should try instead 227 * to put a limit on the length of the list on each bucket...). 228 * 229 * Each dynamic rule holds a pointer to the parent ipfw rule so 230 * we know what action to perform. Dynamic rules are removed when 231 * the parent rule is deleted. XXX we should make them survive. 232 * 233 * There are some limitations with dynamic rules -- we do not 234 * obey the 'randomized match', and we do not do multiple 235 * passes through the firewall. XXX check the latter!!! 236 */ 237static ipfw_dyn_rule **ipfw_dyn_v = NULL; 238static u_int32_t dyn_buckets = 256; /* must be power of 2 */ 239static u_int32_t curr_dyn_buckets = 256; /* must be power of 2 */ 240 241static struct mtx ipfw_dyn_mtx; /* mutex guarding dynamic rules */ 242#define IPFW_DYN_LOCK_INIT() \ 243 mtx_init(&ipfw_dyn_mtx, "IPFW dynamic rules", NULL, MTX_DEF) 244#define IPFW_DYN_LOCK_DESTROY() mtx_destroy(&ipfw_dyn_mtx) 245#define IPFW_DYN_LOCK() mtx_lock(&ipfw_dyn_mtx) 246#define IPFW_DYN_UNLOCK() mtx_unlock(&ipfw_dyn_mtx) 247#define IPFW_DYN_LOCK_ASSERT() mtx_assert(&ipfw_dyn_mtx, MA_OWNED) 248 249/* 250 * Timeouts for various events in handing dynamic rules. 251 */ 252static u_int32_t dyn_ack_lifetime = 300; 253static u_int32_t dyn_syn_lifetime = 20; 254static u_int32_t dyn_fin_lifetime = 1; 255static u_int32_t dyn_rst_lifetime = 1; 256static u_int32_t dyn_udp_lifetime = 10; 257static u_int32_t dyn_short_lifetime = 5; 258 259/* 260 * Keepalives are sent if dyn_keepalive is set. They are sent every 261 * dyn_keepalive_period seconds, in the last dyn_keepalive_interval 262 * seconds of lifetime of a rule. 263 * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower 264 * than dyn_keepalive_period. 265 */ 266 267static u_int32_t dyn_keepalive_interval = 20; 268static u_int32_t dyn_keepalive_period = 5; 269static u_int32_t dyn_keepalive = 1; /* do send keepalives */ 270 271static u_int32_t static_count; /* # of static rules */ 272static u_int32_t static_len; /* size in bytes of static rules */ 273static u_int32_t dyn_count; /* # of dynamic rules */ 274static u_int32_t dyn_max = 4096; /* max # of dynamic rules */ 275 276SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLFLAG_RW, 277 &dyn_buckets, 0, "Number of dyn. buckets"); 278SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_RD, 279 &curr_dyn_buckets, 0, "Current Number of dyn. buckets"); 280SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_RD, 281 &dyn_count, 0, "Number of dyn. rules"); 282SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_RW, 283 &dyn_max, 0, "Max number of dyn. rules"); 284SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, CTLFLAG_RD, 285 &static_count, 0, "Number of static rules"); 286SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_RW, 287 &dyn_ack_lifetime, 0, "Lifetime of dyn. rules for acks"); 288SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_RW, 289 &dyn_syn_lifetime, 0, "Lifetime of dyn. rules for syn"); 290SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, CTLFLAG_RW, 291 &dyn_fin_lifetime, 0, "Lifetime of dyn. rules for fin"); 292SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, CTLFLAG_RW, 293 &dyn_rst_lifetime, 0, "Lifetime of dyn. rules for rst"); 294SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime, CTLFLAG_RW, 295 &dyn_udp_lifetime, 0, "Lifetime of dyn. rules for UDP"); 296SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_RW, 297 &dyn_short_lifetime, 0, "Lifetime of dyn. rules for other situations"); 298SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_keepalive, CTLFLAG_RW, 299 &dyn_keepalive, 0, "Enable keepalives for dyn. rules"); 300 301#ifdef INET6 302/* 303 * IPv6 specific variables 304 */ 305SYSCTL_DECL(_net_inet6_ip6); 306 307static struct sysctl_ctx_list ip6_fw_sysctl_ctx; 308static struct sysctl_oid *ip6_fw_sysctl_tree; 309#endif /* INET6 */ 310#endif /* SYSCTL_NODE */ 311 312#ifdef IPFIREWALL_NAT 313MODULE_DEPEND(ipfw, libalias, 1, 1, 1); 314#endif 315static int fw_deny_unknown_exthdrs = 1; 316 317 318/* 319 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 320 * Other macros just cast void * into the appropriate type 321 */ 322#define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 323#define TCP(p) ((struct tcphdr *)(p)) 324#define SCTP(p) ((struct sctphdr *)(p)) 325#define UDP(p) ((struct udphdr *)(p)) 326#define ICMP(p) ((struct icmphdr *)(p)) 327#define ICMP6(p) ((struct icmp6_hdr *)(p)) 328 329static __inline int 330icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 331{ 332 int type = icmp->icmp_type; 333 334 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 335} 336 337#define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 338 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 339 340static int 341is_icmp_query(struct icmphdr *icmp) 342{ 343 int type = icmp->icmp_type; 344 345 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 346} 347#undef TT 348 349/* 350 * The following checks use two arrays of 8 or 16 bits to store the 351 * bits that we want set or clear, respectively. They are in the 352 * low and high half of cmd->arg1 or cmd->d[0]. 353 * 354 * We scan options and store the bits we find set. We succeed if 355 * 356 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 357 * 358 * The code is sometimes optimized not to store additional variables. 359 */ 360 361static int 362flags_match(ipfw_insn *cmd, u_int8_t bits) 363{ 364 u_char want_clear; 365 bits = ~bits; 366 367 if ( ((cmd->arg1 & 0xff) & bits) != 0) 368 return 0; /* some bits we want set were clear */ 369 want_clear = (cmd->arg1 >> 8) & 0xff; 370 if ( (want_clear & bits) != want_clear) 371 return 0; /* some bits we want clear were set */ 372 return 1; 373} 374 375static int 376ipopts_match(struct ip *ip, ipfw_insn *cmd) 377{ 378 int optlen, bits = 0; 379 u_char *cp = (u_char *)(ip + 1); 380 int x = (ip->ip_hl << 2) - sizeof (struct ip); 381 382 for (; x > 0; x -= optlen, cp += optlen) { 383 int opt = cp[IPOPT_OPTVAL]; 384 385 if (opt == IPOPT_EOL) 386 break; 387 if (opt == IPOPT_NOP) 388 optlen = 1; 389 else { 390 optlen = cp[IPOPT_OLEN]; 391 if (optlen <= 0 || optlen > x) 392 return 0; /* invalid or truncated */ 393 } 394 switch (opt) { 395 396 default: 397 break; 398 399 case IPOPT_LSRR: 400 bits |= IP_FW_IPOPT_LSRR; 401 break; 402 403 case IPOPT_SSRR: 404 bits |= IP_FW_IPOPT_SSRR; 405 break; 406 407 case IPOPT_RR: 408 bits |= IP_FW_IPOPT_RR; 409 break; 410 411 case IPOPT_TS: 412 bits |= IP_FW_IPOPT_TS; 413 break; 414 } 415 } 416 return (flags_match(cmd, bits)); 417} 418 419static int 420tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 421{ 422 int optlen, bits = 0; 423 u_char *cp = (u_char *)(tcp + 1); 424 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 425 426 for (; x > 0; x -= optlen, cp += optlen) { 427 int opt = cp[0]; 428 if (opt == TCPOPT_EOL) 429 break; 430 if (opt == TCPOPT_NOP) 431 optlen = 1; 432 else { 433 optlen = cp[1]; 434 if (optlen <= 0) 435 break; 436 } 437 438 switch (opt) { 439 440 default: 441 break; 442 443 case TCPOPT_MAXSEG: 444 bits |= IP_FW_TCPOPT_MSS; 445 break; 446 447 case TCPOPT_WINDOW: 448 bits |= IP_FW_TCPOPT_WINDOW; 449 break; 450 451 case TCPOPT_SACK_PERMITTED: 452 case TCPOPT_SACK: 453 bits |= IP_FW_TCPOPT_SACK; 454 break; 455 456 case TCPOPT_TIMESTAMP: 457 bits |= IP_FW_TCPOPT_TS; 458 break; 459 460 } 461 } 462 return (flags_match(cmd, bits)); 463} 464 465static int 466iface_match(struct ifnet *ifp, ipfw_insn_if *cmd) 467{ 468 if (ifp == NULL) /* no iface with this packet, match fails */ 469 return 0; 470 /* Check by name or by IP address */ 471 if (cmd->name[0] != '\0') { /* match by name */ 472 /* Check name */ 473 if (cmd->p.glob) { 474 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 475 return(1); 476 } else { 477 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 478 return(1); 479 } 480 } else { 481 struct ifaddr *ia; 482 483 /* XXX lock? */ 484 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 485 if (ia->ifa_addr->sa_family != AF_INET) 486 continue; 487 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 488 (ia->ifa_addr))->sin_addr.s_addr) 489 return(1); /* match */ 490 } 491 } 492 return(0); /* no match, fail ... */ 493} 494 495/* 496 * The verify_path function checks if a route to the src exists and 497 * if it is reachable via ifp (when provided). 498 * 499 * The 'verrevpath' option checks that the interface that an IP packet 500 * arrives on is the same interface that traffic destined for the 501 * packet's source address would be routed out of. The 'versrcreach' 502 * option just checks that the source address is reachable via any route 503 * (except default) in the routing table. These two are a measure to block 504 * forged packets. This is also commonly known as "anti-spoofing" or Unicast 505 * Reverse Path Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 506 * is purposely reminiscent of the Cisco IOS command, 507 * 508 * ip verify unicast reverse-path 509 * ip verify unicast source reachable-via any 510 * 511 * which implements the same functionality. But note that syntax is 512 * misleading. The check may be performed on all IP packets whether unicast, 513 * multicast, or broadcast. 514 */ 515static int 516verify_path(struct in_addr src, struct ifnet *ifp) 517{ 518 struct route ro; 519 struct sockaddr_in *dst; 520 521 bzero(&ro, sizeof(ro)); 522 523 dst = (struct sockaddr_in *)&(ro.ro_dst); 524 dst->sin_family = AF_INET; 525 dst->sin_len = sizeof(*dst); 526 dst->sin_addr = src; 527 rtalloc_ign(&ro, RTF_CLONING); 528 529 if (ro.ro_rt == NULL) 530 return 0; 531 532 /* 533 * If ifp is provided, check for equality with rtentry. 534 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 535 * in order to pass packets injected back by if_simloop(): 536 * if useloopback == 1 routing entry (via lo0) for our own address 537 * may exist, so we need to handle routing assymetry. 538 */ 539 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 540 RTFREE(ro.ro_rt); 541 return 0; 542 } 543 544 /* if no ifp provided, check if rtentry is not default route */ 545 if (ifp == NULL && 546 satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) { 547 RTFREE(ro.ro_rt); 548 return 0; 549 } 550 551 /* or if this is a blackhole/reject route */ 552 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 553 RTFREE(ro.ro_rt); 554 return 0; 555 } 556 557 /* found valid route */ 558 RTFREE(ro.ro_rt); 559 return 1; 560} 561 562#ifdef INET6 563/* 564 * ipv6 specific rules here... 565 */ 566static __inline int 567icmp6type_match (int type, ipfw_insn_u32 *cmd) 568{ 569 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 570} 571 572static int 573flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 574{ 575 int i; 576 for (i=0; i <= cmd->o.arg1; ++i ) 577 if (curr_flow == cmd->d[i] ) 578 return 1; 579 return 0; 580} 581 582/* support for IP6_*_ME opcodes */ 583static int 584search_ip6_addr_net (struct in6_addr * ip6_addr) 585{ 586 struct ifnet *mdc; 587 struct ifaddr *mdc2; 588 struct in6_ifaddr *fdm; 589 struct in6_addr copia; 590 591 TAILQ_FOREACH(mdc, &ifnet, if_link) 592 TAILQ_FOREACH(mdc2, &mdc->if_addrlist, ifa_list) { 593 if (mdc2->ifa_addr->sa_family == AF_INET6) { 594 fdm = (struct in6_ifaddr *)mdc2; 595 copia = fdm->ia_addr.sin6_addr; 596 /* need for leaving scope_id in the sock_addr */ 597 in6_clearscope(&copia); 598 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) 599 return 1; 600 } 601 } 602 return 0; 603} 604 605static int 606verify_path6(struct in6_addr *src, struct ifnet *ifp) 607{ 608 struct route_in6 ro; 609 struct sockaddr_in6 *dst; 610 611 bzero(&ro, sizeof(ro)); 612 613 dst = (struct sockaddr_in6 * )&(ro.ro_dst); 614 dst->sin6_family = AF_INET6; 615 dst->sin6_len = sizeof(*dst); 616 dst->sin6_addr = *src; 617 rtalloc_ign((struct route *)&ro, RTF_CLONING); 618 619 if (ro.ro_rt == NULL) 620 return 0; 621 622 /* 623 * if ifp is provided, check for equality with rtentry 624 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 625 * to support the case of sending packets to an address of our own. 626 * (where the former interface is the first argument of if_simloop() 627 * (=ifp), the latter is lo0) 628 */ 629 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 630 RTFREE(ro.ro_rt); 631 return 0; 632 } 633 634 /* if no ifp provided, check if rtentry is not default route */ 635 if (ifp == NULL && 636 IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) { 637 RTFREE(ro.ro_rt); 638 return 0; 639 } 640 641 /* or if this is a blackhole/reject route */ 642 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 643 RTFREE(ro.ro_rt); 644 return 0; 645 } 646 647 /* found valid route */ 648 RTFREE(ro.ro_rt); 649 return 1; 650 651} 652static __inline int 653hash_packet6(struct ipfw_flow_id *id) 654{ 655 u_int32_t i; 656 i = (id->dst_ip6.__u6_addr.__u6_addr32[2]) ^ 657 (id->dst_ip6.__u6_addr.__u6_addr32[3]) ^ 658 (id->src_ip6.__u6_addr.__u6_addr32[2]) ^ 659 (id->src_ip6.__u6_addr.__u6_addr32[3]) ^ 660 (id->dst_port) ^ (id->src_port); 661 return i; 662} 663 664static int 665is_icmp6_query(int icmp6_type) 666{ 667 if ((icmp6_type <= ICMP6_MAXTYPE) && 668 (icmp6_type == ICMP6_ECHO_REQUEST || 669 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 670 icmp6_type == ICMP6_WRUREQUEST || 671 icmp6_type == ICMP6_FQDN_QUERY || 672 icmp6_type == ICMP6_NI_QUERY)) 673 return (1); 674 675 return (0); 676} 677 678static void 679send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 680{ 681 struct mbuf *m; 682 683 m = args->m; 684 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 685 struct tcphdr *tcp; 686 tcp_seq ack, seq; 687 int flags; 688 struct { 689 struct ip6_hdr ip6; 690 struct tcphdr th; 691 } ti; 692 tcp = (struct tcphdr *)((char *)ip6 + hlen); 693 694 if ((tcp->th_flags & TH_RST) != 0) { 695 m_freem(m); 696 args->m = NULL; 697 return; 698 } 699 700 ti.ip6 = *ip6; 701 ti.th = *tcp; 702 ti.th.th_seq = ntohl(ti.th.th_seq); 703 ti.th.th_ack = ntohl(ti.th.th_ack); 704 ti.ip6.ip6_nxt = IPPROTO_TCP; 705 706 if (ti.th.th_flags & TH_ACK) { 707 ack = 0; 708 seq = ti.th.th_ack; 709 flags = TH_RST; 710 } else { 711 ack = ti.th.th_seq; 712 if ((m->m_flags & M_PKTHDR) != 0) { 713 /* 714 * total new data to ACK is: 715 * total packet length, 716 * minus the header length, 717 * minus the tcp header length. 718 */ 719 ack += m->m_pkthdr.len - hlen 720 - (ti.th.th_off << 2); 721 } else if (ip6->ip6_plen) { 722 ack += ntohs(ip6->ip6_plen) + sizeof(*ip6) - 723 hlen - (ti.th.th_off << 2); 724 } else { 725 m_freem(m); 726 return; 727 } 728 if (tcp->th_flags & TH_SYN) 729 ack++; 730 seq = 0; 731 flags = TH_RST|TH_ACK; 732 } 733 bcopy(&ti, ip6, sizeof(ti)); 734 /* 735 * m is only used to recycle the mbuf 736 * The data in it is never read so we don't need 737 * to correct the offsets or anything 738 */ 739 tcp_respond(NULL, ip6, tcp, m, ack, seq, flags); 740 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */ 741#if 0 742 /* 743 * Unlike above, the mbufs need to line up with the ip6 hdr, 744 * as the contents are read. We need to m_adj() the 745 * needed amount. 746 * The mbuf will however be thrown away so we can adjust it. 747 * Remember we did an m_pullup on it already so we 748 * can make some assumptions about contiguousness. 749 */ 750 if (args->L3offset) 751 m_adj(m, args->L3offset); 752#endif 753 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 754 } else 755 m_freem(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, uint32_t tablearg, 774 struct ip *ip) 775{ 776 struct ether_header *eh = args->eh; 777 char *action; 778 int limit_reached = 0; 779 char action2[40], proto[128], fragment[32]; 780 781 fragment[0] = '\0'; 782 proto[0] = '\0'; 783 784 if (f == NULL) { /* bogus pkt */ 785 if (verbose_limit != 0 && norule_counter >= verbose_limit) 786 return; 787 norule_counter++; 788 if (norule_counter == verbose_limit) 789 limit_reached = verbose_limit; 790 action = "Refuse"; 791 } else { /* O_LOG is the first action, find the real one */ 792 ipfw_insn *cmd = ACTION_PTR(f); 793 ipfw_insn_log *l = (ipfw_insn_log *)cmd; 794 795 if (l->max_log != 0 && l->log_left == 0) 796 return; 797 l->log_left--; 798 if (l->log_left == 0) 799 limit_reached = l->max_log; 800 cmd += F_LEN(cmd); /* point to first action */ 801 if (cmd->opcode == O_ALTQ) { 802 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 803 804 snprintf(SNPARGS(action2, 0), "Altq %d", 805 altq->qid); 806 cmd += F_LEN(cmd); 807 } 808 if (cmd->opcode == O_PROB) 809 cmd += F_LEN(cmd); 810 811 if (cmd->opcode == O_TAG) 812 cmd += F_LEN(cmd); 813 814 action = action2; 815 switch (cmd->opcode) { 816 case O_DENY: 817 action = "Deny"; 818 break; 819 820 case O_REJECT: 821 if (cmd->arg1==ICMP_REJECT_RST) 822 action = "Reset"; 823 else if (cmd->arg1==ICMP_UNREACH_HOST) 824 action = "Reject"; 825 else 826 snprintf(SNPARGS(action2, 0), "Unreach %d", 827 cmd->arg1); 828 break; 829 830 case O_UNREACH6: 831 if (cmd->arg1==ICMP6_UNREACH_RST) 832 action = "Reset"; 833 else 834 snprintf(SNPARGS(action2, 0), "Unreach %d", 835 cmd->arg1); 836 break; 837 838 case O_ACCEPT: 839 action = "Accept"; 840 break; 841 case O_COUNT: 842 action = "Count"; 843 break; 844 case O_DIVERT: 845 snprintf(SNPARGS(action2, 0), "Divert %d", 846 cmd->arg1); 847 break; 848 case O_TEE: 849 snprintf(SNPARGS(action2, 0), "Tee %d", 850 cmd->arg1); 851 break; 852 case O_SKIPTO: 853 snprintf(SNPARGS(action2, 0), "SkipTo %d", 854 cmd->arg1); 855 break; 856 case O_PIPE: 857 snprintf(SNPARGS(action2, 0), "Pipe %d", 858 cmd->arg1); 859 break; 860 case O_QUEUE: 861 snprintf(SNPARGS(action2, 0), "Queue %d", 862 cmd->arg1); 863 break; 864 case O_FORWARD_IP: { 865 ipfw_insn_sa *sa = (ipfw_insn_sa *)cmd; 866 int len; 867 struct in_addr dummyaddr; 868 if (sa->sa.sin_addr.s_addr == INADDR_ANY) 869 dummyaddr.s_addr = htonl(tablearg); 870 else 871 dummyaddr.s_addr = sa->sa.sin_addr.s_addr; 872 873 len = snprintf(SNPARGS(action2, 0), "Forward to %s", 874 inet_ntoa(dummyaddr)); 875 876 if (sa->sa.sin_port) 877 snprintf(SNPARGS(action2, len), ":%d", 878 sa->sa.sin_port); 879 } 880 break; 881 case O_NETGRAPH: 882 snprintf(SNPARGS(action2, 0), "Netgraph %d", 883 cmd->arg1); 884 break; 885 case O_NGTEE: 886 snprintf(SNPARGS(action2, 0), "Ngtee %d", 887 cmd->arg1); 888 break; 889 case O_NAT: 890 action = "Nat"; 891 break; 892 default: 893 action = "UNKNOWN"; 894 break; 895 } 896 } 897 898 if (hlen == 0) { /* non-ip */ 899 snprintf(SNPARGS(proto, 0), "MAC"); 900 901 } else { 902 int len; 903 char src[48], dst[48]; 904 struct icmphdr *icmp; 905 struct tcphdr *tcp; 906 struct udphdr *udp; 907#ifdef INET6 908 struct ip6_hdr *ip6 = NULL; 909 struct icmp6_hdr *icmp6; 910#endif 911 src[0] = '\0'; 912 dst[0] = '\0'; 913#ifdef INET6 914 if (IS_IP6_FLOW_ID(&(args->f_id))) { 915 char ip6buf[INET6_ADDRSTRLEN]; 916 snprintf(src, sizeof(src), "[%s]", 917 ip6_sprintf(ip6buf, &args->f_id.src_ip6)); 918 snprintf(dst, sizeof(dst), "[%s]", 919 ip6_sprintf(ip6buf, &args->f_id.dst_ip6)); 920 921 ip6 = (struct ip6_hdr *)ip; 922 tcp = (struct tcphdr *)(((char *)ip) + hlen); 923 udp = (struct udphdr *)(((char *)ip) + hlen); 924 } else 925#endif 926 { 927 tcp = L3HDR(struct tcphdr, ip); 928 udp = L3HDR(struct udphdr, ip); 929 930 inet_ntoa_r(ip->ip_src, src); 931 inet_ntoa_r(ip->ip_dst, dst); 932 } 933 934 switch (args->f_id.proto) { 935 case IPPROTO_TCP: 936 len = snprintf(SNPARGS(proto, 0), "TCP %s", src); 937 if (offset == 0) 938 snprintf(SNPARGS(proto, len), ":%d %s:%d", 939 ntohs(tcp->th_sport), 940 dst, 941 ntohs(tcp->th_dport)); 942 else 943 snprintf(SNPARGS(proto, len), " %s", dst); 944 break; 945 946 case IPPROTO_UDP: 947 len = snprintf(SNPARGS(proto, 0), "UDP %s", src); 948 if (offset == 0) 949 snprintf(SNPARGS(proto, len), ":%d %s:%d", 950 ntohs(udp->uh_sport), 951 dst, 952 ntohs(udp->uh_dport)); 953 else 954 snprintf(SNPARGS(proto, len), " %s", dst); 955 break; 956 957 case IPPROTO_ICMP: 958 icmp = L3HDR(struct icmphdr, ip); 959 if (offset == 0) 960 len = snprintf(SNPARGS(proto, 0), 961 "ICMP:%u.%u ", 962 icmp->icmp_type, icmp->icmp_code); 963 else 964 len = snprintf(SNPARGS(proto, 0), "ICMP "); 965 len += snprintf(SNPARGS(proto, len), "%s", src); 966 snprintf(SNPARGS(proto, len), " %s", dst); 967 break; 968#ifdef INET6 969 case IPPROTO_ICMPV6: 970 icmp6 = (struct icmp6_hdr *)(((char *)ip) + hlen); 971 if (offset == 0) 972 len = snprintf(SNPARGS(proto, 0), 973 "ICMPv6:%u.%u ", 974 icmp6->icmp6_type, icmp6->icmp6_code); 975 else 976 len = snprintf(SNPARGS(proto, 0), "ICMPv6 "); 977 len += snprintf(SNPARGS(proto, len), "%s", src); 978 snprintf(SNPARGS(proto, len), " %s", dst); 979 break; 980#endif 981 default: 982 len = snprintf(SNPARGS(proto, 0), "P:%d %s", 983 args->f_id.proto, src); 984 snprintf(SNPARGS(proto, len), " %s", dst); 985 break; 986 } 987 988#ifdef INET6 989 if (IS_IP6_FLOW_ID(&(args->f_id))) { 990 if (offset & (IP6F_OFF_MASK | IP6F_MORE_FRAG)) 991 snprintf(SNPARGS(fragment, 0), 992 " (frag %08x:%d@%d%s)", 993 args->f_id.frag_id6, 994 ntohs(ip6->ip6_plen) - hlen, 995 ntohs(offset & IP6F_OFF_MASK) << 3, 996 (offset & IP6F_MORE_FRAG) ? "+" : ""); 997 } else 998#endif 999 { 1000 int ip_off, ip_len; 1001 if (eh != NULL) { /* layer 2 packets are as on the wire */ 1002 ip_off = ntohs(ip->ip_off); 1003 ip_len = ntohs(ip->ip_len); 1004 } else { 1005 ip_off = ip->ip_off; 1006 ip_len = ip->ip_len; 1007 } 1008 if (ip_off & (IP_MF | IP_OFFMASK)) 1009 snprintf(SNPARGS(fragment, 0), 1010 " (frag %d:%d@%d%s)", 1011 ntohs(ip->ip_id), ip_len - (ip->ip_hl << 2), 1012 offset << 3, 1013 (ip_off & IP_MF) ? "+" : ""); 1014 } 1015 } 1016 if (oif || m->m_pkthdr.rcvif) 1017 log(LOG_SECURITY | LOG_INFO, 1018 "ipfw: %d %s %s %s via %s%s\n", 1019 f ? f->rulenum : -1, 1020 action, proto, oif ? "out" : "in", 1021 oif ? oif->if_xname : m->m_pkthdr.rcvif->if_xname, 1022 fragment); 1023 else 1024 log(LOG_SECURITY | LOG_INFO, 1025 "ipfw: %d %s %s [no if info]%s\n", 1026 f ? f->rulenum : -1, 1027 action, proto, fragment); 1028 if (limit_reached) 1029 log(LOG_SECURITY | LOG_NOTICE, 1030 "ipfw: limit %d reached on entry %d\n", 1031 limit_reached, f ? f->rulenum : -1); 1032} 1033 1034/* 1035 * IMPORTANT: the hash function for dynamic rules must be commutative 1036 * in source and destination (ip,port), because rules are bidirectional 1037 * and we want to find both in the same bucket. 1038 */ 1039static __inline int 1040hash_packet(struct ipfw_flow_id *id) 1041{ 1042 u_int32_t i; 1043 1044#ifdef INET6 1045 if (IS_IP6_FLOW_ID(id)) 1046 i = hash_packet6(id); 1047 else 1048#endif /* INET6 */ 1049 i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port); 1050 i &= (curr_dyn_buckets - 1); 1051 return i; 1052} 1053 1054/** 1055 * unlink a dynamic rule from a chain. prev is a pointer to 1056 * the previous one, q is a pointer to the rule to delete, 1057 * head is a pointer to the head of the queue. 1058 * Modifies q and potentially also head. 1059 */ 1060#define UNLINK_DYN_RULE(prev, head, q) { \ 1061 ipfw_dyn_rule *old_q = q; \ 1062 \ 1063 /* remove a refcount to the parent */ \ 1064 if (q->dyn_type == O_LIMIT) \ 1065 q->parent->count--; \ 1066 DEB(printf("ipfw: unlink entry 0x%08x %d -> 0x%08x %d, %d left\n",\ 1067 (q->id.src_ip), (q->id.src_port), \ 1068 (q->id.dst_ip), (q->id.dst_port), dyn_count-1 ); ) \ 1069 if (prev != NULL) \ 1070 prev->next = q = q->next; \ 1071 else \ 1072 head = q = q->next; \ 1073 dyn_count--; \ 1074 uma_zfree(ipfw_dyn_rule_zone, old_q); } 1075 1076#define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0) 1077 1078/** 1079 * Remove dynamic rules pointing to "rule", or all of them if rule == NULL. 1080 * 1081 * If keep_me == NULL, rules are deleted even if not expired, 1082 * otherwise only expired rules are removed. 1083 * 1084 * The value of the second parameter is also used to point to identify 1085 * a rule we absolutely do not want to remove (e.g. because we are 1086 * holding a reference to it -- this is the case with O_LIMIT_PARENT 1087 * rules). The pointer is only used for comparison, so any non-null 1088 * value will do. 1089 */ 1090static void 1091remove_dyn_rule(struct ip_fw *rule, ipfw_dyn_rule *keep_me) 1092{ 1093 static u_int32_t last_remove = 0; 1094 1095#define FORCE (keep_me == NULL) 1096 1097 ipfw_dyn_rule *prev, *q; 1098 int i, pass = 0, max_pass = 0; 1099 1100 IPFW_DYN_LOCK_ASSERT(); 1101 1102 if (ipfw_dyn_v == NULL || dyn_count == 0) 1103 return; 1104 /* do not expire more than once per second, it is useless */ 1105 if (!FORCE && last_remove == time_uptime) 1106 return; 1107 last_remove = time_uptime; 1108 1109 /* 1110 * because O_LIMIT refer to parent rules, during the first pass only 1111 * remove child and mark any pending LIMIT_PARENT, and remove 1112 * them in a second pass. 1113 */ 1114next_pass: 1115 for (i = 0 ; i < curr_dyn_buckets ; i++) { 1116 for (prev=NULL, q = ipfw_dyn_v[i] ; q ; ) { 1117 /* 1118 * Logic can become complex here, so we split tests. 1119 */ 1120 if (q == keep_me) 1121 goto next; 1122 if (rule != NULL && rule != q->rule) 1123 goto next; /* not the one we are looking for */ 1124 if (q->dyn_type == O_LIMIT_PARENT) { 1125 /* 1126 * handle parent in the second pass, 1127 * record we need one. 1128 */ 1129 max_pass = 1; 1130 if (pass == 0) 1131 goto next; 1132 if (FORCE && q->count != 0 ) { 1133 /* XXX should not happen! */ 1134 printf("ipfw: OUCH! cannot remove rule," 1135 " count %d\n", q->count); 1136 } 1137 } else { 1138 if (!FORCE && 1139 !TIME_LEQ( q->expire, time_uptime )) 1140 goto next; 1141 } 1142 if (q->dyn_type != O_LIMIT_PARENT || !q->count) { 1143 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q); 1144 continue; 1145 } 1146next: 1147 prev=q; 1148 q=q->next; 1149 } 1150 } 1151 if (pass++ < max_pass) 1152 goto next_pass; 1153} 1154 1155 1156/** 1157 * lookup a dynamic rule. 1158 */ 1159static ipfw_dyn_rule * 1160lookup_dyn_rule_locked(struct ipfw_flow_id *pkt, int *match_direction, 1161 struct tcphdr *tcp) 1162{ 1163 /* 1164 * stateful ipfw extensions. 1165 * Lookup into dynamic session queue 1166 */ 1167#define MATCH_REVERSE 0 1168#define MATCH_FORWARD 1 1169#define MATCH_NONE 2 1170#define MATCH_UNKNOWN 3 1171 int i, dir = MATCH_NONE; 1172 ipfw_dyn_rule *prev, *q=NULL; 1173 1174 IPFW_DYN_LOCK_ASSERT(); 1175 1176 if (ipfw_dyn_v == NULL) 1177 goto done; /* not found */ 1178 i = hash_packet( pkt ); 1179 for (prev=NULL, q = ipfw_dyn_v[i] ; q != NULL ; ) { 1180 if (q->dyn_type == O_LIMIT_PARENT && q->count) 1181 goto next; 1182 if (TIME_LEQ( q->expire, time_uptime)) { /* expire entry */ 1183 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q); 1184 continue; 1185 } 1186 if (pkt->proto == q->id.proto && 1187 q->dyn_type != O_LIMIT_PARENT) { 1188 if (IS_IP6_FLOW_ID(pkt)) { 1189 if (IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1190 &(q->id.src_ip6)) && 1191 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1192 &(q->id.dst_ip6)) && 1193 pkt->src_port == q->id.src_port && 1194 pkt->dst_port == q->id.dst_port ) { 1195 dir = MATCH_FORWARD; 1196 break; 1197 } 1198 if (IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1199 &(q->id.dst_ip6)) && 1200 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1201 &(q->id.src_ip6)) && 1202 pkt->src_port == q->id.dst_port && 1203 pkt->dst_port == q->id.src_port ) { 1204 dir = MATCH_REVERSE; 1205 break; 1206 } 1207 } else { 1208 if (pkt->src_ip == q->id.src_ip && 1209 pkt->dst_ip == q->id.dst_ip && 1210 pkt->src_port == q->id.src_port && 1211 pkt->dst_port == q->id.dst_port ) { 1212 dir = MATCH_FORWARD; 1213 break; 1214 } 1215 if (pkt->src_ip == q->id.dst_ip && 1216 pkt->dst_ip == q->id.src_ip && 1217 pkt->src_port == q->id.dst_port && 1218 pkt->dst_port == q->id.src_port ) { 1219 dir = MATCH_REVERSE; 1220 break; 1221 } 1222 } 1223 } 1224next: 1225 prev = q; 1226 q = q->next; 1227 } 1228 if (q == NULL) 1229 goto done; /* q = NULL, not found */ 1230 1231 if ( prev != NULL) { /* found and not in front */ 1232 prev->next = q->next; 1233 q->next = ipfw_dyn_v[i]; 1234 ipfw_dyn_v[i] = q; 1235 } 1236 if (pkt->proto == IPPROTO_TCP) { /* update state according to flags */ 1237 u_char flags = pkt->flags & (TH_FIN|TH_SYN|TH_RST); 1238 1239#define BOTH_SYN (TH_SYN | (TH_SYN << 8)) 1240#define BOTH_FIN (TH_FIN | (TH_FIN << 8)) 1241 q->state |= (dir == MATCH_FORWARD ) ? flags : (flags << 8); 1242 switch (q->state) { 1243 case TH_SYN: /* opening */ 1244 q->expire = time_uptime + dyn_syn_lifetime; 1245 break; 1246 1247 case BOTH_SYN: /* move to established */ 1248 case BOTH_SYN | TH_FIN : /* one side tries to close */ 1249 case BOTH_SYN | (TH_FIN << 8) : 1250 if (tcp) { 1251#define _SEQ_GE(a,b) ((int)(a) - (int)(b) >= 0) 1252 u_int32_t ack = ntohl(tcp->th_ack); 1253 if (dir == MATCH_FORWARD) { 1254 if (q->ack_fwd == 0 || _SEQ_GE(ack, q->ack_fwd)) 1255 q->ack_fwd = ack; 1256 else { /* ignore out-of-sequence */ 1257 break; 1258 } 1259 } else { 1260 if (q->ack_rev == 0 || _SEQ_GE(ack, q->ack_rev)) 1261 q->ack_rev = ack; 1262 else { /* ignore out-of-sequence */ 1263 break; 1264 } 1265 } 1266 } 1267 q->expire = time_uptime + dyn_ack_lifetime; 1268 break; 1269 1270 case BOTH_SYN | BOTH_FIN: /* both sides closed */ 1271 if (dyn_fin_lifetime >= dyn_keepalive_period) 1272 dyn_fin_lifetime = dyn_keepalive_period - 1; 1273 q->expire = time_uptime + dyn_fin_lifetime; 1274 break; 1275 1276 default: 1277#if 0 1278 /* 1279 * reset or some invalid combination, but can also 1280 * occur if we use keep-state the wrong way. 1281 */ 1282 if ( (q->state & ((TH_RST << 8)|TH_RST)) == 0) 1283 printf("invalid state: 0x%x\n", q->state); 1284#endif 1285 if (dyn_rst_lifetime >= dyn_keepalive_period) 1286 dyn_rst_lifetime = dyn_keepalive_period - 1; 1287 q->expire = time_uptime + dyn_rst_lifetime; 1288 break; 1289 } 1290 } else if (pkt->proto == IPPROTO_UDP) { 1291 q->expire = time_uptime + dyn_udp_lifetime; 1292 } else { 1293 /* other protocols */ 1294 q->expire = time_uptime + dyn_short_lifetime; 1295 } 1296done: 1297 if (match_direction) 1298 *match_direction = dir; 1299 return q; 1300} 1301 1302static ipfw_dyn_rule * 1303lookup_dyn_rule(struct ipfw_flow_id *pkt, int *match_direction, 1304 struct tcphdr *tcp) 1305{ 1306 ipfw_dyn_rule *q; 1307 1308 IPFW_DYN_LOCK(); 1309 q = lookup_dyn_rule_locked(pkt, match_direction, tcp); 1310 if (q == NULL) 1311 IPFW_DYN_UNLOCK(); 1312 /* NB: return table locked when q is not NULL */ 1313 return q; 1314} 1315 1316static void 1317realloc_dynamic_table(void) 1318{ 1319 IPFW_DYN_LOCK_ASSERT(); 1320 1321 /* 1322 * Try reallocation, make sure we have a power of 2 and do 1323 * not allow more than 64k entries. In case of overflow, 1324 * default to 1024. 1325 */ 1326 1327 if (dyn_buckets > 65536) 1328 dyn_buckets = 1024; 1329 if ((dyn_buckets & (dyn_buckets-1)) != 0) { /* not a power of 2 */ 1330 dyn_buckets = curr_dyn_buckets; /* reset */ 1331 return; 1332 } 1333 curr_dyn_buckets = dyn_buckets; 1334 if (ipfw_dyn_v != NULL) 1335 free(ipfw_dyn_v, M_IPFW); 1336 for (;;) { 1337 ipfw_dyn_v = malloc(curr_dyn_buckets * sizeof(ipfw_dyn_rule *), 1338 M_IPFW, M_NOWAIT | M_ZERO); 1339 if (ipfw_dyn_v != NULL || curr_dyn_buckets <= 2) 1340 break; 1341 curr_dyn_buckets /= 2; 1342 } 1343} 1344 1345/** 1346 * Install state of type 'type' for a dynamic session. 1347 * The hash table contains two type of rules: 1348 * - regular rules (O_KEEP_STATE) 1349 * - rules for sessions with limited number of sess per user 1350 * (O_LIMIT). When they are created, the parent is 1351 * increased by 1, and decreased on delete. In this case, 1352 * the third parameter is the parent rule and not the chain. 1353 * - "parent" rules for the above (O_LIMIT_PARENT). 1354 */ 1355static ipfw_dyn_rule * 1356add_dyn_rule(struct ipfw_flow_id *id, u_int8_t dyn_type, struct ip_fw *rule) 1357{ 1358 ipfw_dyn_rule *r; 1359 int i; 1360 1361 IPFW_DYN_LOCK_ASSERT(); 1362 1363 if (ipfw_dyn_v == NULL || 1364 (dyn_count == 0 && dyn_buckets != curr_dyn_buckets)) { 1365 realloc_dynamic_table(); 1366 if (ipfw_dyn_v == NULL) 1367 return NULL; /* failed ! */ 1368 } 1369 i = hash_packet(id); 1370 1371 r = uma_zalloc(ipfw_dyn_rule_zone, M_NOWAIT | M_ZERO); 1372 if (r == NULL) { 1373 printf ("ipfw: sorry cannot allocate state\n"); 1374 return NULL; 1375 } 1376 1377 /* increase refcount on parent, and set pointer */ 1378 if (dyn_type == O_LIMIT) { 1379 ipfw_dyn_rule *parent = (ipfw_dyn_rule *)rule; 1380 if ( parent->dyn_type != O_LIMIT_PARENT) 1381 panic("invalid parent"); 1382 parent->count++; 1383 r->parent = parent; 1384 rule = parent->rule; 1385 } 1386 1387 r->id = *id; 1388 r->expire = time_uptime + dyn_syn_lifetime; 1389 r->rule = rule; 1390 r->dyn_type = dyn_type; 1391 r->pcnt = r->bcnt = 0; 1392 r->count = 0; 1393 1394 r->bucket = i; 1395 r->next = ipfw_dyn_v[i]; 1396 ipfw_dyn_v[i] = r; 1397 dyn_count++; 1398 DEB(printf("ipfw: add dyn entry ty %d 0x%08x %d -> 0x%08x %d, total %d\n", 1399 dyn_type, 1400 (r->id.src_ip), (r->id.src_port), 1401 (r->id.dst_ip), (r->id.dst_port), 1402 dyn_count ); ) 1403 return r; 1404} 1405 1406/** 1407 * lookup dynamic parent rule using pkt and rule as search keys. 1408 * If the lookup fails, then install one. 1409 */ 1410static ipfw_dyn_rule * 1411lookup_dyn_parent(struct ipfw_flow_id *pkt, struct ip_fw *rule) 1412{ 1413 ipfw_dyn_rule *q; 1414 int i; 1415 1416 IPFW_DYN_LOCK_ASSERT(); 1417 1418 if (ipfw_dyn_v) { 1419 int is_v6 = IS_IP6_FLOW_ID(pkt); 1420 i = hash_packet( pkt ); 1421 for (q = ipfw_dyn_v[i] ; q != NULL ; q=q->next) 1422 if (q->dyn_type == O_LIMIT_PARENT && 1423 rule== q->rule && 1424 pkt->proto == q->id.proto && 1425 pkt->src_port == q->id.src_port && 1426 pkt->dst_port == q->id.dst_port && 1427 ( 1428 (is_v6 && 1429 IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1430 &(q->id.src_ip6)) && 1431 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1432 &(q->id.dst_ip6))) || 1433 (!is_v6 && 1434 pkt->src_ip == q->id.src_ip && 1435 pkt->dst_ip == q->id.dst_ip) 1436 ) 1437 ) { 1438 q->expire = time_uptime + dyn_short_lifetime; 1439 DEB(printf("ipfw: lookup_dyn_parent found 0x%p\n",q);) 1440 return q; 1441 } 1442 } 1443 return add_dyn_rule(pkt, O_LIMIT_PARENT, rule); 1444} 1445 1446/** 1447 * Install dynamic state for rule type cmd->o.opcode 1448 * 1449 * Returns 1 (failure) if state is not installed because of errors or because 1450 * session limitations are enforced. 1451 */ 1452static int 1453install_state(struct ip_fw *rule, ipfw_insn_limit *cmd, 1454 struct ip_fw_args *args, uint32_t tablearg) 1455{ 1456 static int last_log; 1457 ipfw_dyn_rule *q; 1458 struct in_addr da; 1459 char src[48], dst[48]; 1460 1461 src[0] = '\0'; 1462 dst[0] = '\0'; 1463 1464 DEB( 1465 printf("ipfw: %s: type %d 0x%08x %u -> 0x%08x %u\n", 1466 __func__, cmd->o.opcode, 1467 (args->f_id.src_ip), (args->f_id.src_port), 1468 (args->f_id.dst_ip), (args->f_id.dst_port)); 1469 ) 1470 1471 IPFW_DYN_LOCK(); 1472 1473 q = lookup_dyn_rule_locked(&args->f_id, NULL, NULL); 1474 1475 if (q != NULL) { /* should never occur */ 1476 if (last_log != time_uptime) { 1477 last_log = time_uptime; 1478 printf("ipfw: %s: entry already present, done\n", 1479 __func__); 1480 } 1481 IPFW_DYN_UNLOCK(); 1482 return (0); 1483 } 1484 1485 if (dyn_count >= dyn_max) 1486 /* Run out of slots, try to remove any expired rule. */ 1487 remove_dyn_rule(NULL, (ipfw_dyn_rule *)1); 1488 1489 if (dyn_count >= dyn_max) { 1490 if (last_log != time_uptime) { 1491 last_log = time_uptime; 1492 printf("ipfw: %s: Too many dynamic rules\n", __func__); 1493 } 1494 IPFW_DYN_UNLOCK(); 1495 return (1); /* cannot install, notify caller */ 1496 } 1497 1498 switch (cmd->o.opcode) { 1499 case O_KEEP_STATE: /* bidir rule */ 1500 add_dyn_rule(&args->f_id, O_KEEP_STATE, rule); 1501 break; 1502 1503 case O_LIMIT: { /* limit number of sessions */ 1504 struct ipfw_flow_id id; 1505 ipfw_dyn_rule *parent; 1506 uint32_t conn_limit; 1507 uint16_t limit_mask = cmd->limit_mask; 1508 1509 conn_limit = (cmd->conn_limit == IP_FW_TABLEARG) ? 1510 tablearg : cmd->conn_limit; 1511 1512 DEB( 1513 if (cmd->conn_limit == IP_FW_TABLEARG) 1514 printf("ipfw: %s: O_LIMIT rule, conn_limit: %u " 1515 "(tablearg)\n", __func__, conn_limit); 1516 else 1517 printf("ipfw: %s: O_LIMIT rule, conn_limit: %u\n", 1518 __func__, conn_limit); 1519 ) 1520 1521 id.dst_ip = id.src_ip = id.dst_port = id.src_port = 0; 1522 id.proto = args->f_id.proto; 1523 id.addr_type = args->f_id.addr_type; 1524 1525 if (IS_IP6_FLOW_ID (&(args->f_id))) { 1526 if (limit_mask & DYN_SRC_ADDR) 1527 id.src_ip6 = args->f_id.src_ip6; 1528 if (limit_mask & DYN_DST_ADDR) 1529 id.dst_ip6 = args->f_id.dst_ip6; 1530 } else { 1531 if (limit_mask & DYN_SRC_ADDR) 1532 id.src_ip = args->f_id.src_ip; 1533 if (limit_mask & DYN_DST_ADDR) 1534 id.dst_ip = args->f_id.dst_ip; 1535 } 1536 if (limit_mask & DYN_SRC_PORT) 1537 id.src_port = args->f_id.src_port; 1538 if (limit_mask & DYN_DST_PORT) 1539 id.dst_port = args->f_id.dst_port; 1540 if ((parent = lookup_dyn_parent(&id, rule)) == NULL) { 1541 printf("ipfw: %s: add parent failed\n", __func__); 1542 IPFW_DYN_UNLOCK(); 1543 return (1); 1544 } 1545 1546 if (parent->count >= conn_limit) { 1547 /* See if we can remove some expired rule. */ 1548 remove_dyn_rule(rule, parent); 1549 if (parent->count >= conn_limit) { 1550 if (fw_verbose && last_log != time_uptime) { 1551 last_log = time_uptime; 1552#ifdef INET6 1553 /* 1554 * XXX IPv6 flows are not 1555 * supported yet. 1556 */ 1557 if (IS_IP6_FLOW_ID(&(args->f_id))) { 1558 char ip6buf[INET6_ADDRSTRLEN]; 1559 snprintf(src, sizeof(src), 1560 "[%s]", ip6_sprintf(ip6buf, 1561 &args->f_id.src_ip6)); 1562 snprintf(dst, sizeof(dst), 1563 "[%s]", ip6_sprintf(ip6buf, 1564 &args->f_id.dst_ip6)); 1565 } else 1566#endif 1567 { 1568 da.s_addr = 1569 htonl(args->f_id.src_ip); 1570 inet_ntoa_r(da, src); 1571 da.s_addr = 1572 htonl(args->f_id.dst_ip); 1573 inet_ntoa_r(da, dst); 1574 } 1575 log(LOG_SECURITY | LOG_DEBUG, 1576 "%s %s:%u -> %s:%u, %s\n", 1577 "drop session", 1578 src, (args->f_id.src_port), 1579 dst, (args->f_id.dst_port), 1580 "too many entries"); 1581 } 1582 IPFW_DYN_UNLOCK(); 1583 return (1); 1584 } 1585 } 1586 add_dyn_rule(&args->f_id, O_LIMIT, (struct ip_fw *)parent); 1587 break; 1588 } 1589 default: 1590 printf("ipfw: %s: unknown dynamic rule type %u\n", 1591 __func__, cmd->o.opcode); 1592 IPFW_DYN_UNLOCK(); 1593 return (1); 1594 } 1595 1596 /* XXX just set lifetime */ 1597 lookup_dyn_rule_locked(&args->f_id, NULL, NULL); 1598 1599 IPFW_DYN_UNLOCK(); 1600 return (0); 1601} 1602 1603/* 1604 * Generate a TCP packet, containing either a RST or a keepalive. 1605 * When flags & TH_RST, we are sending a RST packet, because of a 1606 * "reset" action matched the packet. 1607 * Otherwise we are sending a keepalive, and flags & TH_ 1608 * The 'replyto' mbuf is the mbuf being replied to, if any, and is required 1609 * so that MAC can label the reply appropriately. 1610 */ 1611static struct mbuf * 1612send_pkt(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t seq, 1613 u_int32_t ack, int flags) 1614{ 1615 struct mbuf *m; 1616 struct ip *ip; 1617 struct tcphdr *tcp; 1618 1619 MGETHDR(m, M_DONTWAIT, MT_DATA); 1620 if (m == 0) 1621 return (NULL); 1622 m->m_pkthdr.rcvif = (struct ifnet *)0; 1623 1624#ifdef MAC 1625 if (replyto != NULL) 1626 mac_create_mbuf_netlayer(replyto, m); 1627 else 1628 mac_create_mbuf_from_firewall(m); 1629#else 1630 (void)replyto; /* don't warn about unused arg */ 1631#endif 1632 1633 m->m_pkthdr.len = m->m_len = sizeof(struct ip) + sizeof(struct tcphdr); 1634 m->m_data += max_linkhdr; 1635 1636 ip = mtod(m, struct ip *); 1637 bzero(ip, m->m_len); 1638 tcp = (struct tcphdr *)(ip + 1); /* no IP options */ 1639 ip->ip_p = IPPROTO_TCP; 1640 tcp->th_off = 5; 1641 /* 1642 * Assume we are sending a RST (or a keepalive in the reverse 1643 * direction), swap src and destination addresses and ports. 1644 */ 1645 ip->ip_src.s_addr = htonl(id->dst_ip); 1646 ip->ip_dst.s_addr = htonl(id->src_ip); 1647 tcp->th_sport = htons(id->dst_port); 1648 tcp->th_dport = htons(id->src_port); 1649 if (flags & TH_RST) { /* we are sending a RST */ 1650 if (flags & TH_ACK) { 1651 tcp->th_seq = htonl(ack); 1652 tcp->th_ack = htonl(0); 1653 tcp->th_flags = TH_RST; 1654 } else { 1655 if (flags & TH_SYN) 1656 seq++; 1657 tcp->th_seq = htonl(0); 1658 tcp->th_ack = htonl(seq); 1659 tcp->th_flags = TH_RST | TH_ACK; 1660 } 1661 } else { 1662 /* 1663 * We are sending a keepalive. flags & TH_SYN determines 1664 * the direction, forward if set, reverse if clear. 1665 * NOTE: seq and ack are always assumed to be correct 1666 * as set by the caller. This may be confusing... 1667 */ 1668 if (flags & TH_SYN) { 1669 /* 1670 * we have to rewrite the correct addresses! 1671 */ 1672 ip->ip_dst.s_addr = htonl(id->dst_ip); 1673 ip->ip_src.s_addr = htonl(id->src_ip); 1674 tcp->th_dport = htons(id->dst_port); 1675 tcp->th_sport = htons(id->src_port); 1676 } 1677 tcp->th_seq = htonl(seq); 1678 tcp->th_ack = htonl(ack); 1679 tcp->th_flags = TH_ACK; 1680 } 1681 /* 1682 * set ip_len to the payload size so we can compute 1683 * the tcp checksum on the pseudoheader 1684 * XXX check this, could save a couple of words ? 1685 */ 1686 ip->ip_len = htons(sizeof(struct tcphdr)); 1687 tcp->th_sum = in_cksum(m, m->m_pkthdr.len); 1688 /* 1689 * now fill fields left out earlier 1690 */ 1691 ip->ip_ttl = ip_defttl; 1692 ip->ip_len = m->m_pkthdr.len; 1693 m->m_flags |= M_SKIP_FIREWALL; 1694 return (m); 1695} 1696 1697/* 1698 * sends a reject message, consuming the mbuf passed as an argument. 1699 */ 1700static void 1701send_reject(struct ip_fw_args *args, int code, int ip_len, struct ip *ip) 1702{ 1703 1704#if 0 1705 /* XXX When ip is not guaranteed to be at mtod() we will 1706 * need to account for this */ 1707 * The mbuf will however be thrown away so we can adjust it. 1708 * Remember we did an m_pullup on it already so we 1709 * can make some assumptions about contiguousness. 1710 */ 1711 if (args->L3offset) 1712 m_adj(m, args->L3offset); 1713#endif 1714 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */ 1715 /* We need the IP header in host order for icmp_error(). */ 1716 if (args->eh != NULL) { 1717 ip->ip_len = ntohs(ip->ip_len); 1718 ip->ip_off = ntohs(ip->ip_off); 1719 } 1720 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 1721 } else if (args->f_id.proto == IPPROTO_TCP) { 1722 struct tcphdr *const tcp = 1723 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 1724 if ( (tcp->th_flags & TH_RST) == 0) { 1725 struct mbuf *m; 1726 m = send_pkt(args->m, &(args->f_id), 1727 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 1728 tcp->th_flags | TH_RST); 1729 if (m != NULL) 1730 ip_output(m, NULL, NULL, 0, NULL, NULL); 1731 } 1732 m_freem(args->m); 1733 } else 1734 m_freem(args->m); 1735 args->m = NULL; 1736} 1737 1738/** 1739 * 1740 * Given an ip_fw *, lookup_next_rule will return a pointer 1741 * to the next rule, which can be either the jump 1742 * target (for skipto instructions) or the next one in the list (in 1743 * all other cases including a missing jump target). 1744 * The result is also written in the "next_rule" field of the rule. 1745 * Backward jumps are not allowed, so start looking from the next 1746 * rule... 1747 * 1748 * This never returns NULL -- in case we do not have an exact match, 1749 * the next rule is returned. When the ruleset is changed, 1750 * pointers are flushed so we are always correct. 1751 */ 1752 1753static struct ip_fw * 1754lookup_next_rule(struct ip_fw *me) 1755{ 1756 struct ip_fw *rule = NULL; 1757 ipfw_insn *cmd; 1758 1759 /* look for action, in case it is a skipto */ 1760 cmd = ACTION_PTR(me); 1761 if (cmd->opcode == O_LOG) 1762 cmd += F_LEN(cmd); 1763 if (cmd->opcode == O_ALTQ) 1764 cmd += F_LEN(cmd); 1765 if (cmd->opcode == O_TAG) 1766 cmd += F_LEN(cmd); 1767 if ( cmd->opcode == O_SKIPTO ) 1768 for (rule = me->next; rule ; rule = rule->next) 1769 if (rule->rulenum >= cmd->arg1) 1770 break; 1771 if (rule == NULL) /* failure or not a skipto */ 1772 rule = me->next; 1773 me->next_rule = rule; 1774 return rule; 1775} 1776 1777static int 1778add_table_entry(struct ip_fw_chain *ch, uint16_t tbl, in_addr_t addr, 1779 uint8_t mlen, uint32_t value) 1780{ 1781 struct radix_node_head *rnh; 1782 struct table_entry *ent; 1783 1784 if (tbl >= IPFW_TABLES_MAX) 1785 return (EINVAL); 1786 rnh = ch->tables[tbl]; 1787 ent = malloc(sizeof(*ent), M_IPFW_TBL, M_NOWAIT | M_ZERO); 1788 if (ent == NULL) 1789 return (ENOMEM); 1790 ent->value = value; 1791 ent->addr.sin_len = ent->mask.sin_len = 8; 1792 ent->mask.sin_addr.s_addr = htonl(mlen ? ~((1 << (32 - mlen)) - 1) : 0); 1793 ent->addr.sin_addr.s_addr = addr & ent->mask.sin_addr.s_addr; 1794 IPFW_WLOCK(&layer3_chain); 1795 if (rnh->rnh_addaddr(&ent->addr, &ent->mask, rnh, (void *)ent) == 1796 NULL) { 1797 IPFW_WUNLOCK(&layer3_chain); 1798 free(ent, M_IPFW_TBL); 1799 return (EEXIST); 1800 } 1801 IPFW_WUNLOCK(&layer3_chain); 1802 return (0); 1803} 1804 1805static int 1806del_table_entry(struct ip_fw_chain *ch, uint16_t tbl, in_addr_t addr, 1807 uint8_t mlen) 1808{ 1809 struct radix_node_head *rnh; 1810 struct table_entry *ent; 1811 struct sockaddr_in sa, mask; 1812 1813 if (tbl >= IPFW_TABLES_MAX) 1814 return (EINVAL); 1815 rnh = ch->tables[tbl]; 1816 sa.sin_len = mask.sin_len = 8; 1817 mask.sin_addr.s_addr = htonl(mlen ? ~((1 << (32 - mlen)) - 1) : 0); 1818 sa.sin_addr.s_addr = addr & mask.sin_addr.s_addr; 1819 IPFW_WLOCK(ch); 1820 ent = (struct table_entry *)rnh->rnh_deladdr(&sa, &mask, rnh); 1821 if (ent == NULL) { 1822 IPFW_WUNLOCK(ch); 1823 return (ESRCH); 1824 } 1825 IPFW_WUNLOCK(ch); 1826 free(ent, M_IPFW_TBL); 1827 return (0); 1828} 1829 1830static int 1831flush_table_entry(struct radix_node *rn, void *arg) 1832{ 1833 struct radix_node_head * const rnh = arg; 1834 struct table_entry *ent; 1835 1836 ent = (struct table_entry *) 1837 rnh->rnh_deladdr(rn->rn_key, rn->rn_mask, rnh); 1838 if (ent != NULL) 1839 free(ent, M_IPFW_TBL); 1840 return (0); 1841} 1842 1843static int 1844flush_table(struct ip_fw_chain *ch, uint16_t tbl) 1845{ 1846 struct radix_node_head *rnh; 1847 1848 IPFW_WLOCK_ASSERT(ch); 1849 1850 if (tbl >= IPFW_TABLES_MAX) 1851 return (EINVAL); 1852 rnh = ch->tables[tbl]; 1853 KASSERT(rnh != NULL, ("NULL IPFW table")); 1854 rnh->rnh_walktree(rnh, flush_table_entry, rnh); 1855 return (0); 1856} 1857 1858static void 1859flush_tables(struct ip_fw_chain *ch) 1860{ 1861 uint16_t tbl; 1862 1863 IPFW_WLOCK_ASSERT(ch); 1864 1865 for (tbl = 0; tbl < IPFW_TABLES_MAX; tbl++) 1866 flush_table(ch, tbl); 1867} 1868 1869static int 1870init_tables(struct ip_fw_chain *ch) 1871{ 1872 int i; 1873 uint16_t j; 1874 1875 for (i = 0; i < IPFW_TABLES_MAX; i++) { 1876 if (!rn_inithead((void **)&ch->tables[i], 32)) { 1877 for (j = 0; j < i; j++) { 1878 (void) flush_table(ch, j); 1879 } 1880 return (ENOMEM); 1881 } 1882 } 1883 return (0); 1884} 1885 1886static int 1887lookup_table(struct ip_fw_chain *ch, uint16_t tbl, in_addr_t addr, 1888 uint32_t *val) 1889{ 1890 struct radix_node_head *rnh; 1891 struct table_entry *ent; 1892 struct sockaddr_in sa; 1893 1894 if (tbl >= IPFW_TABLES_MAX) 1895 return (0); 1896 rnh = ch->tables[tbl]; 1897 sa.sin_len = 8; 1898 sa.sin_addr.s_addr = addr; 1899 ent = (struct table_entry *)(rnh->rnh_lookup(&sa, NULL, rnh)); 1900 if (ent != NULL) { 1901 *val = ent->value; 1902 return (1); 1903 } 1904 return (0); 1905} 1906 1907static int 1908count_table_entry(struct radix_node *rn, void *arg) 1909{ 1910 u_int32_t * const cnt = arg; 1911 1912 (*cnt)++; 1913 return (0); 1914} 1915 1916static int 1917count_table(struct ip_fw_chain *ch, uint32_t tbl, uint32_t *cnt) 1918{ 1919 struct radix_node_head *rnh; 1920 1921 if (tbl >= IPFW_TABLES_MAX) 1922 return (EINVAL); 1923 rnh = ch->tables[tbl]; 1924 *cnt = 0; 1925 rnh->rnh_walktree(rnh, count_table_entry, cnt); 1926 return (0); 1927} 1928 1929static int 1930dump_table_entry(struct radix_node *rn, void *arg) 1931{ 1932 struct table_entry * const n = (struct table_entry *)rn; 1933 ipfw_table * const tbl = arg; 1934 ipfw_table_entry *ent; 1935 1936 if (tbl->cnt == tbl->size) 1937 return (1); 1938 ent = &tbl->ent[tbl->cnt]; 1939 ent->tbl = tbl->tbl; 1940 if (in_nullhost(n->mask.sin_addr)) 1941 ent->masklen = 0; 1942 else 1943 ent->masklen = 33 - ffs(ntohl(n->mask.sin_addr.s_addr)); 1944 ent->addr = n->addr.sin_addr.s_addr; 1945 ent->value = n->value; 1946 tbl->cnt++; 1947 return (0); 1948} 1949 1950static int 1951dump_table(struct ip_fw_chain *ch, ipfw_table *tbl) 1952{ 1953 struct radix_node_head *rnh; 1954 1955 if (tbl->tbl >= IPFW_TABLES_MAX) 1956 return (EINVAL); 1957 rnh = ch->tables[tbl->tbl]; 1958 tbl->cnt = 0; 1959 rnh->rnh_walktree(rnh, dump_table_entry, tbl); 1960 return (0); 1961} 1962 1963static void 1964fill_ugid_cache(struct inpcb *inp, struct ip_fw_ugid *ugp) 1965{ 1966 struct ucred *cr; 1967 1968 if (inp->inp_socket != NULL) { 1969 cr = inp->inp_socket->so_cred; 1970 ugp->fw_prid = jailed(cr) ? 1971 cr->cr_prison->pr_id : -1; 1972 ugp->fw_uid = cr->cr_uid; 1973 ugp->fw_ngroups = cr->cr_ngroups; 1974 bcopy(cr->cr_groups, ugp->fw_groups, 1975 sizeof(ugp->fw_groups)); 1976 } 1977} 1978 1979static int 1980check_uidgid(ipfw_insn_u32 *insn, 1981 int proto, struct ifnet *oif, 1982 struct in_addr dst_ip, u_int16_t dst_port, 1983 struct in_addr src_ip, u_int16_t src_port, 1984 struct ip_fw_ugid *ugp, int *lookup, struct inpcb *inp) 1985{ 1986 struct inpcbinfo *pi; 1987 int wildcard; 1988 struct inpcb *pcb; 1989 int match; 1990 gid_t *gp; 1991 1992 /* 1993 * Check to see if the UDP or TCP stack supplied us with 1994 * the PCB. If so, rather then holding a lock and looking 1995 * up the PCB, we can use the one that was supplied. 1996 */ 1997 if (inp && *lookup == 0) { 1998 INP_LOCK_ASSERT(inp); 1999 if (inp->inp_socket != NULL) { 2000 fill_ugid_cache(inp, ugp); 2001 *lookup = 1; 2002 } 2003 } 2004 /* 2005 * If we have already been here and the packet has no 2006 * PCB entry associated with it, then we can safely 2007 * assume that this is a no match. 2008 */ 2009 if (*lookup == -1) 2010 return (0); 2011 if (proto == IPPROTO_TCP) { 2012 wildcard = 0; 2013 pi = &tcbinfo; 2014 } else if (proto == IPPROTO_UDP) { 2015 wildcard = INPLOOKUP_WILDCARD; 2016 pi = &udbinfo; 2017 } else 2018 return 0; 2019 match = 0; 2020 if (*lookup == 0) { 2021 INP_INFO_RLOCK(pi); 2022 pcb = (oif) ? 2023 in_pcblookup_hash(pi, 2024 dst_ip, htons(dst_port), 2025 src_ip, htons(src_port), 2026 wildcard, oif) : 2027 in_pcblookup_hash(pi, 2028 src_ip, htons(src_port), 2029 dst_ip, htons(dst_port), 2030 wildcard, NULL); 2031 if (pcb != NULL) { 2032 INP_LOCK(pcb); 2033 if (pcb->inp_socket != NULL) { 2034 fill_ugid_cache(pcb, ugp); 2035 *lookup = 1; 2036 } 2037 INP_UNLOCK(pcb); 2038 } 2039 INP_INFO_RUNLOCK(pi); 2040 if (*lookup == 0) { 2041 /* 2042 * If the lookup did not yield any results, there 2043 * is no sense in coming back and trying again. So 2044 * we can set lookup to -1 and ensure that we wont 2045 * bother the pcb system again. 2046 */ 2047 *lookup = -1; 2048 return (0); 2049 } 2050 } 2051 if (insn->o.opcode == O_UID) 2052 match = (ugp->fw_uid == (uid_t)insn->d[0]); 2053 else if (insn->o.opcode == O_GID) { 2054 for (gp = ugp->fw_groups; 2055 gp < &ugp->fw_groups[ugp->fw_ngroups]; gp++) 2056 if (*gp == (gid_t)insn->d[0]) { 2057 match = 1; 2058 break; 2059 } 2060 } else if (insn->o.opcode == O_JAIL) 2061 match = (ugp->fw_prid == (int)insn->d[0]); 2062 return match; 2063} 2064 2065#ifdef IPFIREWALL_NAT 2066static eventhandler_tag ifaddr_event_tag; 2067 2068static void 2069ifaddr_change(void *arg __unused, struct ifnet *ifp) { 2070 struct cfg_nat *ptr; 2071 struct ifaddr *ifa; 2072 2073 IPFW_WLOCK(&layer3_chain); 2074 /* Check every nat entry... */ 2075 LIST_FOREACH(ptr, &layer3_chain.nat, _next) { 2076 /* ...using nic 'ifp->if_xname' as dynamic alias address. */ 2077 if (strncmp(ptr->if_name, ifp->if_xname, IF_NAMESIZE) == 0) { 2078 mtx_lock(&ifp->if_addr_mtx); 2079 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 2080 if (ifa->ifa_addr == NULL) 2081 continue; 2082 if (ifa->ifa_addr->sa_family != AF_INET) 2083 continue; 2084 ptr->ip = ((struct sockaddr_in *) 2085 (ifa->ifa_addr))->sin_addr; 2086 LibAliasSetAddress(ptr->lib, ptr->ip); 2087 } 2088 mtx_unlock(&ifp->if_addr_mtx); 2089 } 2090 } 2091 IPFW_WUNLOCK(&layer3_chain); 2092} 2093 2094static void 2095flush_nat_ptrs(const int i) { 2096 struct ip_fw *rule; 2097 2098 IPFW_WLOCK_ASSERT(&layer3_chain); 2099 for (rule = layer3_chain.rules; rule; rule = rule->next) { 2100 ipfw_insn_nat *cmd = (ipfw_insn_nat *)ACTION_PTR(rule); 2101 if (cmd->o.opcode != O_NAT) 2102 continue; 2103 if (cmd->nat != NULL && cmd->nat->id == i) 2104 cmd->nat = NULL; 2105 } 2106} 2107 2108static struct cfg_nat * 2109lookup_nat(const int i) { 2110 struct cfg_nat *ptr; 2111 2112 LIST_FOREACH(ptr, &layer3_chain.nat, _next) 2113 if (ptr->id == i) 2114 return(ptr); 2115 return (NULL); 2116} 2117 2118#define HOOK_NAT(b, p) do { \ 2119 IPFW_WLOCK_ASSERT(&layer3_chain); \ 2120 LIST_INSERT_HEAD(b, p, _next); \ 2121} while (0) 2122 2123#define UNHOOK_NAT(p) do { \ 2124 IPFW_WLOCK_ASSERT(&layer3_chain); \ 2125 LIST_REMOVE(p, _next); \ 2126} while (0) 2127 2128#define HOOK_REDIR(b, p) do { \ 2129 LIST_INSERT_HEAD(b, p, _next); \ 2130} while (0) 2131 2132#define HOOK_SPOOL(b, p) do { \ 2133 LIST_INSERT_HEAD(b, p, _next); \ 2134} while (0) 2135 2136static void 2137del_redir_spool_cfg(struct cfg_nat *n, struct redir_chain *head) { 2138 struct cfg_redir *r, *tmp_r; 2139 struct cfg_spool *s, *tmp_s; 2140 int i, num; 2141 2142 LIST_FOREACH_SAFE(r, head, _next, tmp_r) { 2143 num = 1; /* Number of alias_link to delete. */ 2144 switch (r->mode) { 2145 case REDIR_PORT: 2146 num = r->pport_cnt; 2147 /* FALLTHROUGH */ 2148 case REDIR_ADDR: 2149 case REDIR_PROTO: 2150 /* Delete all libalias redirect entry. */ 2151 for (i = 0; i < num; i++) 2152 LibAliasRedirectDelete(n->lib, r->alink[i]); 2153 /* Del spool cfg if any. */ 2154 LIST_FOREACH_SAFE(s, &r->spool_chain, _next, tmp_s) { 2155 LIST_REMOVE(s, _next); 2156 free(s, M_IPFW); 2157 } 2158 free(r->alink, M_IPFW); 2159 LIST_REMOVE(r, _next); 2160 free(r, M_IPFW); 2161 break; 2162 default: 2163 printf("unknown redirect mode: %u\n", r->mode); 2164 /* XXX - panic?!?!? */ 2165 break; 2166 } 2167 } 2168} 2169 2170static int 2171add_redir_spool_cfg(char *buf, struct cfg_nat *ptr) { 2172 struct cfg_redir *r, *ser_r; 2173 struct cfg_spool *s, *ser_s; 2174 int cnt, off, i; 2175 char *panic_err; 2176 2177 for (cnt = 0, off = 0; cnt < ptr->redir_cnt; cnt++) { 2178 ser_r = (struct cfg_redir *)&buf[off]; 2179 r = malloc(SOF_REDIR, M_IPFW, M_WAITOK | M_ZERO); 2180 memcpy(r, ser_r, SOF_REDIR); 2181 LIST_INIT(&r->spool_chain); 2182 off += SOF_REDIR; 2183 r->alink = malloc(sizeof(struct alias_link *) * r->pport_cnt, 2184 M_IPFW, M_WAITOK | M_ZERO); 2185 switch (r->mode) { 2186 case REDIR_ADDR: 2187 r->alink[0] = LibAliasRedirectAddr(ptr->lib, r->laddr, 2188 r->paddr); 2189 break; 2190 case REDIR_PORT: 2191 for (i = 0 ; i < r->pport_cnt; i++) { 2192 /* If remotePort is all ports, set it to 0. */ 2193 u_short remotePortCopy = r->rport + i; 2194 if (r->rport_cnt == 1 && r->rport == 0) 2195 remotePortCopy = 0; 2196 r->alink[i] = LibAliasRedirectPort(ptr->lib, 2197 r->laddr, htons(r->lport + i), r->raddr, 2198 htons(remotePortCopy), r->paddr, 2199 htons(r->pport + i), r->proto); 2200 if (r->alink[i] == NULL) { 2201 r->alink[0] = NULL; 2202 break; 2203 } 2204 } 2205 break; 2206 case REDIR_PROTO: 2207 r->alink[0] = LibAliasRedirectProto(ptr->lib ,r->laddr, 2208 r->raddr, r->paddr, r->proto); 2209 break; 2210 default: 2211 printf("unknown redirect mode: %u\n", r->mode); 2212 break; 2213 } 2214 if (r->alink[0] == NULL) { 2215 panic_err = "LibAliasRedirect* returned NULL"; 2216 goto bad; 2217 } else /* LSNAT handling. */ 2218 for (i = 0; i < r->spool_cnt; i++) { 2219 ser_s = (struct cfg_spool *)&buf[off]; 2220 s = malloc(SOF_REDIR, M_IPFW, 2221 M_WAITOK | M_ZERO); 2222 memcpy(s, ser_s, SOF_SPOOL); 2223 LibAliasAddServer(ptr->lib, r->alink[0], 2224 s->addr, htons(s->port)); 2225 off += SOF_SPOOL; 2226 /* Hook spool entry. */ 2227 HOOK_SPOOL(&r->spool_chain, s); 2228 } 2229 /* And finally hook this redir entry. */ 2230 HOOK_REDIR(&ptr->redir_chain, r); 2231 } 2232 return (1); 2233bad: 2234 /* something really bad happened: panic! */ 2235 panic("%s\n", panic_err); 2236} 2237#endif 2238 2239/* 2240 * The main check routine for the firewall. 2241 * 2242 * All arguments are in args so we can modify them and return them 2243 * back to the caller. 2244 * 2245 * Parameters: 2246 * 2247 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 2248 * Starts with the IP header. 2249 * args->eh (in) Mac header if present, or NULL for layer3 packet. 2250 * args->L3offset Number of bytes bypassed if we came from L2. 2251 * e.g. often sizeof(eh) ** NOTYET ** 2252 * args->oif Outgoing interface, or NULL if packet is incoming. 2253 * The incoming interface is in the mbuf. (in) 2254 * args->divert_rule (in/out) 2255 * Skip up to the first rule past this rule number; 2256 * upon return, non-zero port number for divert or tee. 2257 * 2258 * args->rule Pointer to the last matching rule (in/out) 2259 * args->next_hop Socket we are forwarding to (out). 2260 * args->f_id Addresses grabbed from the packet (out) 2261 * args->cookie a cookie depending on rule action 2262 * 2263 * Return value: 2264 * 2265 * IP_FW_PASS the packet must be accepted 2266 * IP_FW_DENY the packet must be dropped 2267 * IP_FW_DIVERT divert packet, port in m_tag 2268 * IP_FW_TEE tee packet, port in m_tag 2269 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 2270 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 2271 * 2272 */ 2273int 2274ipfw_chk(struct ip_fw_args *args) 2275{ 2276 /* 2277 * Local variables holding state during the processing of a packet: 2278 * 2279 * IMPORTANT NOTE: to speed up the processing of rules, there 2280 * are some assumption on the values of the variables, which 2281 * are documented here. Should you change them, please check 2282 * the implementation of the various instructions to make sure 2283 * that they still work. 2284 * 2285 * args->eh The MAC header. It is non-null for a layer2 2286 * packet, it is NULL for a layer-3 packet. 2287 * **notyet** 2288 * args->L3offset Offset in the packet to the L3 (IP or equiv.) header. 2289 * 2290 * m | args->m Pointer to the mbuf, as received from the caller. 2291 * It may change if ipfw_chk() does an m_pullup, or if it 2292 * consumes the packet because it calls send_reject(). 2293 * XXX This has to change, so that ipfw_chk() never modifies 2294 * or consumes the buffer. 2295 * ip is the beginning of the ip(4 or 6) header. 2296 * Calculated by adding the L3offset to the start of data. 2297 * (Until we start using L3offset, the packet is 2298 * supposed to start with the ip header). 2299 */ 2300 struct mbuf *m = args->m; 2301 struct ip *ip = mtod(m, struct ip *); 2302 2303 /* 2304 * For rules which contain uid/gid or jail constraints, cache 2305 * a copy of the users credentials after the pcb lookup has been 2306 * executed. This will speed up the processing of rules with 2307 * these types of constraints, as well as decrease contention 2308 * on pcb related locks. 2309 */ 2310 struct ip_fw_ugid fw_ugid_cache; 2311 int ugid_lookup = 0; 2312 2313 /* 2314 * divinput_flags If non-zero, set to the IP_FW_DIVERT_*_FLAG 2315 * associated with a packet input on a divert socket. This 2316 * will allow to distinguish traffic and its direction when 2317 * it originates from a divert socket. 2318 */ 2319 u_int divinput_flags = 0; 2320 2321 /* 2322 * oif | args->oif If NULL, ipfw_chk has been called on the 2323 * inbound path (ether_input, ip_input). 2324 * If non-NULL, ipfw_chk has been called on the outbound path 2325 * (ether_output, ip_output). 2326 */ 2327 struct ifnet *oif = args->oif; 2328 2329 struct ip_fw *f = NULL; /* matching rule */ 2330 int retval = 0; 2331 2332 /* 2333 * hlen The length of the IP header. 2334 */ 2335 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 2336 2337 /* 2338 * offset The offset of a fragment. offset != 0 means that 2339 * we have a fragment at this offset of an IPv4 packet. 2340 * offset == 0 means that (if this is an IPv4 packet) 2341 * this is the first or only fragment. 2342 * For IPv6 offset == 0 means there is no Fragment Header. 2343 * If offset != 0 for IPv6 always use correct mask to 2344 * get the correct offset because we add IP6F_MORE_FRAG 2345 * to be able to dectect the first fragment which would 2346 * otherwise have offset = 0. 2347 */ 2348 u_short offset = 0; 2349 2350 /* 2351 * Local copies of addresses. They are only valid if we have 2352 * an IP packet. 2353 * 2354 * proto The protocol. Set to 0 for non-ip packets, 2355 * or to the protocol read from the packet otherwise. 2356 * proto != 0 means that we have an IPv4 packet. 2357 * 2358 * src_port, dst_port port numbers, in HOST format. Only 2359 * valid for TCP and UDP packets. 2360 * 2361 * src_ip, dst_ip ip addresses, in NETWORK format. 2362 * Only valid for IPv4 packets. 2363 */ 2364 u_int8_t proto; 2365 u_int16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 2366 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 2367 u_int16_t ip_len=0; 2368 int pktlen; 2369 u_int16_t etype = 0; /* Host order stored ether type */ 2370 2371 /* 2372 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 2373 * MATCH_NONE when checked and not matched (q = NULL), 2374 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) 2375 */ 2376 int dyn_dir = MATCH_UNKNOWN; 2377 ipfw_dyn_rule *q = NULL; 2378 struct ip_fw_chain *chain = &layer3_chain; 2379 struct m_tag *mtag; 2380 2381 /* 2382 * We store in ulp a pointer to the upper layer protocol header. 2383 * In the ipv4 case this is easy to determine from the header, 2384 * but for ipv6 we might have some additional headers in the middle. 2385 * ulp is NULL if not found. 2386 */ 2387 void *ulp = NULL; /* upper layer protocol pointer. */ 2388 /* XXX ipv6 variables */ 2389 int is_ipv6 = 0; 2390 u_int16_t ext_hd = 0; /* bits vector for extension header filtering */ 2391 /* end of ipv6 variables */ 2392 int is_ipv4 = 0; 2393 2394 if (m->m_flags & M_SKIP_FIREWALL) 2395 return (IP_FW_PASS); /* accept */ 2396 2397 pktlen = m->m_pkthdr.len; 2398 proto = args->f_id.proto = 0; /* mark f_id invalid */ 2399 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ 2400 2401/* 2402 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 2403 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 2404 * pointer might become stale after other pullups (but we never use it 2405 * this way). 2406 */ 2407#define PULLUP_TO(len, p, T) \ 2408do { \ 2409 int x = (len) + sizeof(T); \ 2410 if ((m)->m_len < x) { \ 2411 args->m = m = m_pullup(m, x); \ 2412 if (m == NULL) \ 2413 goto pullup_failed; \ 2414 } \ 2415 p = (mtod(m, char *) + (len)); \ 2416} while (0) 2417 2418 /* 2419 * if we have an ether header, 2420 */ 2421 if (args->eh) 2422 etype = ntohs(args->eh->ether_type); 2423 2424 /* Identify IP packets and fill up variables. */ 2425 if (pktlen >= sizeof(struct ip6_hdr) && 2426 (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) { 2427 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 2428 is_ipv6 = 1; 2429 args->f_id.addr_type = 6; 2430 hlen = sizeof(struct ip6_hdr); 2431 proto = ip6->ip6_nxt; 2432 2433 /* Search extension headers to find upper layer protocols */ 2434 while (ulp == NULL) { 2435 switch (proto) { 2436 case IPPROTO_ICMPV6: 2437 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 2438 args->f_id.flags = ICMP6(ulp)->icmp6_type; 2439 break; 2440 2441 case IPPROTO_TCP: 2442 PULLUP_TO(hlen, ulp, struct tcphdr); 2443 dst_port = TCP(ulp)->th_dport; 2444 src_port = TCP(ulp)->th_sport; 2445 args->f_id.flags = TCP(ulp)->th_flags; 2446 break; 2447 2448 case IPPROTO_SCTP: 2449 PULLUP_TO(hlen, ulp, struct sctphdr); 2450 src_port = SCTP(ulp)->src_port; 2451 dst_port = SCTP(ulp)->dest_port; 2452 break; 2453 2454 case IPPROTO_UDP: 2455 PULLUP_TO(hlen, ulp, struct udphdr); 2456 dst_port = UDP(ulp)->uh_dport; 2457 src_port = UDP(ulp)->uh_sport; 2458 break; 2459 2460 case IPPROTO_HOPOPTS: /* RFC 2460 */ 2461 PULLUP_TO(hlen, ulp, struct ip6_hbh); 2462 ext_hd |= EXT_HOPOPTS; 2463 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 2464 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 2465 ulp = NULL; 2466 break; 2467 2468 case IPPROTO_ROUTING: /* RFC 2460 */ 2469 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 2470 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 2471 case 0: 2472 ext_hd |= EXT_RTHDR0; 2473 break; 2474 case 2: 2475 ext_hd |= EXT_RTHDR2; 2476 break; 2477 default: 2478 printf("IPFW2: IPV6 - Unknown Routing " 2479 "Header type(%d)\n", 2480 ((struct ip6_rthdr *)ulp)->ip6r_type); 2481 if (fw_deny_unknown_exthdrs) 2482 return (IP_FW_DENY); 2483 break; 2484 } 2485 ext_hd |= EXT_ROUTING; 2486 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 2487 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 2488 ulp = NULL; 2489 break; 2490 2491 case IPPROTO_FRAGMENT: /* RFC 2460 */ 2492 PULLUP_TO(hlen, ulp, struct ip6_frag); 2493 ext_hd |= EXT_FRAGMENT; 2494 hlen += sizeof (struct ip6_frag); 2495 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 2496 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 2497 IP6F_OFF_MASK; 2498 /* Add IP6F_MORE_FRAG for offset of first 2499 * fragment to be != 0. */ 2500 offset |= ((struct ip6_frag *)ulp)->ip6f_offlg & 2501 IP6F_MORE_FRAG; 2502 if (offset == 0) { 2503 printf("IPFW2: IPV6 - Invalid Fragment " 2504 "Header\n"); 2505 if (fw_deny_unknown_exthdrs) 2506 return (IP_FW_DENY); 2507 break; 2508 } 2509 args->f_id.frag_id6 = 2510 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 2511 ulp = NULL; 2512 break; 2513 2514 case IPPROTO_DSTOPTS: /* RFC 2460 */ 2515 PULLUP_TO(hlen, ulp, struct ip6_hbh); 2516 ext_hd |= EXT_DSTOPTS; 2517 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 2518 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 2519 ulp = NULL; 2520 break; 2521 2522 case IPPROTO_AH: /* RFC 2402 */ 2523 PULLUP_TO(hlen, ulp, struct ip6_ext); 2524 ext_hd |= EXT_AH; 2525 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 2526 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 2527 ulp = NULL; 2528 break; 2529 2530 case IPPROTO_ESP: /* RFC 2406 */ 2531 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 2532 /* Anything past Seq# is variable length and 2533 * data past this ext. header is encrypted. */ 2534 ext_hd |= EXT_ESP; 2535 break; 2536 2537 case IPPROTO_NONE: /* RFC 2460 */ 2538 PULLUP_TO(hlen, ulp, struct ip6_ext); 2539 /* Packet ends here. if ip6e_len!=0 octets 2540 * must be ignored. */ 2541 break; 2542 2543 case IPPROTO_OSPFIGP: 2544 /* XXX OSPF header check? */ 2545 PULLUP_TO(hlen, ulp, struct ip6_ext); 2546 break; 2547 2548 case IPPROTO_PIM: 2549 /* XXX PIM header check? */ 2550 PULLUP_TO(hlen, ulp, struct pim); 2551 break; 2552 2553 case IPPROTO_CARP: 2554 PULLUP_TO(hlen, ulp, struct carp_header); 2555 if (((struct carp_header *)ulp)->carp_version != 2556 CARP_VERSION) 2557 return (IP_FW_DENY); 2558 if (((struct carp_header *)ulp)->carp_type != 2559 CARP_ADVERTISEMENT) 2560 return (IP_FW_DENY); 2561 break; 2562 2563 case IPPROTO_IPV6: /* RFC 2893 */ 2564 PULLUP_TO(hlen, ulp, struct ip6_hdr); 2565 break; 2566 2567 case IPPROTO_IPV4: /* RFC 2893 */ 2568 PULLUP_TO(hlen, ulp, struct ip); 2569 break; 2570 2571 default: 2572 printf("IPFW2: IPV6 - Unknown Extension " 2573 "Header(%d), ext_hd=%x\n", proto, ext_hd); 2574 if (fw_deny_unknown_exthdrs) 2575 return (IP_FW_DENY); 2576 PULLUP_TO(hlen, ulp, struct ip6_ext); 2577 break; 2578 } /*switch */ 2579 } 2580 ip = mtod(m, struct ip *); 2581 ip6 = (struct ip6_hdr *)ip; 2582 args->f_id.src_ip6 = ip6->ip6_src; 2583 args->f_id.dst_ip6 = ip6->ip6_dst; 2584 args->f_id.src_ip = 0; 2585 args->f_id.dst_ip = 0; 2586 args->f_id.flow_id6 = ntohl(ip6->ip6_flow); 2587 } else if (pktlen >= sizeof(struct ip) && 2588 (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) { 2589 is_ipv4 = 1; 2590 hlen = ip->ip_hl << 2; 2591 args->f_id.addr_type = 4; 2592 2593 /* 2594 * Collect parameters into local variables for faster matching. 2595 */ 2596 proto = ip->ip_p; 2597 src_ip = ip->ip_src; 2598 dst_ip = ip->ip_dst; 2599 if (args->eh != NULL) { /* layer 2 packets are as on the wire */ 2600 offset = ntohs(ip->ip_off) & IP_OFFMASK; 2601 ip_len = ntohs(ip->ip_len); 2602 } else { 2603 offset = ip->ip_off & IP_OFFMASK; 2604 ip_len = ip->ip_len; 2605 } 2606 pktlen = ip_len < pktlen ? ip_len : pktlen; 2607 2608 if (offset == 0) { 2609 switch (proto) { 2610 case IPPROTO_TCP: 2611 PULLUP_TO(hlen, ulp, struct tcphdr); 2612 dst_port = TCP(ulp)->th_dport; 2613 src_port = TCP(ulp)->th_sport; 2614 args->f_id.flags = TCP(ulp)->th_flags; 2615 break; 2616 2617 case IPPROTO_UDP: 2618 PULLUP_TO(hlen, ulp, struct udphdr); 2619 dst_port = UDP(ulp)->uh_dport; 2620 src_port = UDP(ulp)->uh_sport; 2621 break; 2622 2623 case IPPROTO_ICMP: 2624 PULLUP_TO(hlen, ulp, struct icmphdr); 2625 args->f_id.flags = ICMP(ulp)->icmp_type; 2626 break; 2627 2628 default: 2629 break; 2630 } 2631 } 2632 2633 ip = mtod(m, struct ip *); 2634 args->f_id.src_ip = ntohl(src_ip.s_addr); 2635 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 2636 } 2637#undef PULLUP_TO 2638 if (proto) { /* we may have port numbers, store them */ 2639 args->f_id.proto = proto; 2640 args->f_id.src_port = src_port = ntohs(src_port); 2641 args->f_id.dst_port = dst_port = ntohs(dst_port); 2642 } 2643 2644 IPFW_RLOCK(chain); 2645 mtag = m_tag_find(m, PACKET_TAG_DIVERT, NULL); 2646 if (args->rule) { 2647 /* 2648 * Packet has already been tagged. Look for the next rule 2649 * to restart processing. 2650 * 2651 * If fw_one_pass != 0 then just accept it. 2652 * XXX should not happen here, but optimized out in 2653 * the caller. 2654 */ 2655 if (fw_one_pass) { 2656 IPFW_RUNLOCK(chain); 2657 return (IP_FW_PASS); 2658 } 2659 2660 f = args->rule->next_rule; 2661 if (f == NULL) 2662 f = lookup_next_rule(args->rule); 2663 } else { 2664 /* 2665 * Find the starting rule. It can be either the first 2666 * one, or the one after divert_rule if asked so. 2667 */ 2668 int skipto = mtag ? divert_cookie(mtag) : 0; 2669 2670 f = chain->rules; 2671 if (args->eh == NULL && skipto != 0) { 2672 if (skipto >= IPFW_DEFAULT_RULE) { 2673 IPFW_RUNLOCK(chain); 2674 return (IP_FW_DENY); /* invalid */ 2675 } 2676 while (f && f->rulenum <= skipto) 2677 f = f->next; 2678 if (f == NULL) { /* drop packet */ 2679 IPFW_RUNLOCK(chain); 2680 return (IP_FW_DENY); 2681 } 2682 } 2683 } 2684 /* reset divert rule to avoid confusion later */ 2685 if (mtag) { 2686 divinput_flags = divert_info(mtag) & 2687 (IP_FW_DIVERT_OUTPUT_FLAG | IP_FW_DIVERT_LOOPBACK_FLAG); 2688 m_tag_delete(m, mtag); 2689 } 2690 2691 /* 2692 * Now scan the rules, and parse microinstructions for each rule. 2693 */ 2694 for (; f; f = f->next) { 2695 ipfw_insn *cmd; 2696 uint32_t tablearg = 0; 2697 int l, cmdlen, skip_or; /* skip rest of OR block */ 2698 2699again: 2700 if (set_disable & (1 << f->set) ) 2701 continue; 2702 2703 skip_or = 0; 2704 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 2705 l -= cmdlen, cmd += cmdlen) { 2706 int match; 2707 2708 /* 2709 * check_body is a jump target used when we find a 2710 * CHECK_STATE, and need to jump to the body of 2711 * the target rule. 2712 */ 2713 2714check_body: 2715 cmdlen = F_LEN(cmd); 2716 /* 2717 * An OR block (insn_1 || .. || insn_n) has the 2718 * F_OR bit set in all but the last instruction. 2719 * The first match will set "skip_or", and cause 2720 * the following instructions to be skipped until 2721 * past the one with the F_OR bit clear. 2722 */ 2723 if (skip_or) { /* skip this instruction */ 2724 if ((cmd->len & F_OR) == 0) 2725 skip_or = 0; /* next one is good */ 2726 continue; 2727 } 2728 match = 0; /* set to 1 if we succeed */ 2729 2730 switch (cmd->opcode) { 2731 /* 2732 * The first set of opcodes compares the packet's 2733 * fields with some pattern, setting 'match' if a 2734 * match is found. At the end of the loop there is 2735 * logic to deal with F_NOT and F_OR flags associated 2736 * with the opcode. 2737 */ 2738 case O_NOP: 2739 match = 1; 2740 break; 2741 2742 case O_FORWARD_MAC: 2743 printf("ipfw: opcode %d unimplemented\n", 2744 cmd->opcode); 2745 break; 2746 2747 case O_GID: 2748 case O_UID: 2749 case O_JAIL: 2750 /* 2751 * We only check offset == 0 && proto != 0, 2752 * as this ensures that we have a 2753 * packet with the ports info. 2754 */ 2755 if (offset!=0) 2756 break; 2757 if (is_ipv6) /* XXX to be fixed later */ 2758 break; 2759 if (proto == IPPROTO_TCP || 2760 proto == IPPROTO_UDP) 2761 match = check_uidgid( 2762 (ipfw_insn_u32 *)cmd, 2763 proto, oif, 2764 dst_ip, dst_port, 2765 src_ip, src_port, &fw_ugid_cache, 2766 &ugid_lookup, args->inp); 2767 break; 2768 2769 case O_RECV: 2770 match = iface_match(m->m_pkthdr.rcvif, 2771 (ipfw_insn_if *)cmd); 2772 break; 2773 2774 case O_XMIT: 2775 match = iface_match(oif, (ipfw_insn_if *)cmd); 2776 break; 2777 2778 case O_VIA: 2779 match = iface_match(oif ? oif : 2780 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd); 2781 break; 2782 2783 case O_MACADDR2: 2784 if (args->eh != NULL) { /* have MAC header */ 2785 u_int32_t *want = (u_int32_t *) 2786 ((ipfw_insn_mac *)cmd)->addr; 2787 u_int32_t *mask = (u_int32_t *) 2788 ((ipfw_insn_mac *)cmd)->mask; 2789 u_int32_t *hdr = (u_int32_t *)args->eh; 2790 2791 match = 2792 ( want[0] == (hdr[0] & mask[0]) && 2793 want[1] == (hdr[1] & mask[1]) && 2794 want[2] == (hdr[2] & mask[2]) ); 2795 } 2796 break; 2797 2798 case O_MAC_TYPE: 2799 if (args->eh != NULL) { 2800 u_int16_t *p = 2801 ((ipfw_insn_u16 *)cmd)->ports; 2802 int i; 2803 2804 for (i = cmdlen - 1; !match && i>0; 2805 i--, p += 2) 2806 match = (etype >= p[0] && 2807 etype <= p[1]); 2808 } 2809 break; 2810 2811 case O_FRAG: 2812 match = (offset != 0); 2813 break; 2814 2815 case O_IN: /* "out" is "not in" */ 2816 match = (oif == NULL); 2817 break; 2818 2819 case O_LAYER2: 2820 match = (args->eh != NULL); 2821 break; 2822 2823 case O_DIVERTED: 2824 match = (cmd->arg1 & 1 && divinput_flags & 2825 IP_FW_DIVERT_LOOPBACK_FLAG) || 2826 (cmd->arg1 & 2 && divinput_flags & 2827 IP_FW_DIVERT_OUTPUT_FLAG); 2828 break; 2829 2830 case O_PROTO: 2831 /* 2832 * We do not allow an arg of 0 so the 2833 * check of "proto" only suffices. 2834 */ 2835 match = (proto == cmd->arg1); 2836 break; 2837 2838 case O_IP_SRC: 2839 match = is_ipv4 && 2840 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2841 src_ip.s_addr); 2842 break; 2843 2844 case O_IP_SRC_LOOKUP: 2845 case O_IP_DST_LOOKUP: 2846 if (is_ipv4) { 2847 uint32_t a = 2848 (cmd->opcode == O_IP_DST_LOOKUP) ? 2849 dst_ip.s_addr : src_ip.s_addr; 2850 uint32_t v; 2851 2852 match = lookup_table(chain, cmd->arg1, a, 2853 &v); 2854 if (!match) 2855 break; 2856 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 2857 match = 2858 ((ipfw_insn_u32 *)cmd)->d[0] == v; 2859 else 2860 tablearg = v; 2861 } 2862 break; 2863 2864 case O_IP_SRC_MASK: 2865 case O_IP_DST_MASK: 2866 if (is_ipv4) { 2867 uint32_t a = 2868 (cmd->opcode == O_IP_DST_MASK) ? 2869 dst_ip.s_addr : src_ip.s_addr; 2870 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 2871 int i = cmdlen-1; 2872 2873 for (; !match && i>0; i-= 2, p+= 2) 2874 match = (p[0] == (a & p[1])); 2875 } 2876 break; 2877 2878 case O_IP_SRC_ME: 2879 if (is_ipv4) { 2880 struct ifnet *tif; 2881 2882 INADDR_TO_IFP(src_ip, tif); 2883 match = (tif != NULL); 2884 } 2885 break; 2886 2887 case O_IP_DST_SET: 2888 case O_IP_SRC_SET: 2889 if (is_ipv4) { 2890 u_int32_t *d = (u_int32_t *)(cmd+1); 2891 u_int32_t addr = 2892 cmd->opcode == O_IP_DST_SET ? 2893 args->f_id.dst_ip : 2894 args->f_id.src_ip; 2895 2896 if (addr < d[0]) 2897 break; 2898 addr -= d[0]; /* subtract base */ 2899 match = (addr < cmd->arg1) && 2900 ( d[ 1 + (addr>>5)] & 2901 (1<<(addr & 0x1f)) ); 2902 } 2903 break; 2904 2905 case O_IP_DST: 2906 match = is_ipv4 && 2907 (((ipfw_insn_ip *)cmd)->addr.s_addr == 2908 dst_ip.s_addr); 2909 break; 2910 2911 case O_IP_DST_ME: 2912 if (is_ipv4) { 2913 struct ifnet *tif; 2914 2915 INADDR_TO_IFP(dst_ip, tif); 2916 match = (tif != NULL); 2917 } 2918 break; 2919 2920 case O_IP_SRCPORT: 2921 case O_IP_DSTPORT: 2922 /* 2923 * offset == 0 && proto != 0 is enough 2924 * to guarantee that we have a 2925 * packet with port info. 2926 */ 2927 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP) 2928 && offset == 0) { 2929 u_int16_t x = 2930 (cmd->opcode == O_IP_SRCPORT) ? 2931 src_port : dst_port ; 2932 u_int16_t *p = 2933 ((ipfw_insn_u16 *)cmd)->ports; 2934 int i; 2935 2936 for (i = cmdlen - 1; !match && i>0; 2937 i--, p += 2) 2938 match = (x>=p[0] && x<=p[1]); 2939 } 2940 break; 2941 2942 case O_ICMPTYPE: 2943 match = (offset == 0 && proto==IPPROTO_ICMP && 2944 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 2945 break; 2946 2947#ifdef INET6 2948 case O_ICMP6TYPE: 2949 match = is_ipv6 && offset == 0 && 2950 proto==IPPROTO_ICMPV6 && 2951 icmp6type_match( 2952 ICMP6(ulp)->icmp6_type, 2953 (ipfw_insn_u32 *)cmd); 2954 break; 2955#endif /* INET6 */ 2956 2957 case O_IPOPT: 2958 match = (is_ipv4 && 2959 ipopts_match(ip, cmd) ); 2960 break; 2961 2962 case O_IPVER: 2963 match = (is_ipv4 && 2964 cmd->arg1 == ip->ip_v); 2965 break; 2966 2967 case O_IPID: 2968 case O_IPLEN: 2969 case O_IPTTL: 2970 if (is_ipv4) { /* only for IP packets */ 2971 uint16_t x; 2972 uint16_t *p; 2973 int i; 2974 2975 if (cmd->opcode == O_IPLEN) 2976 x = ip_len; 2977 else if (cmd->opcode == O_IPTTL) 2978 x = ip->ip_ttl; 2979 else /* must be IPID */ 2980 x = ntohs(ip->ip_id); 2981 if (cmdlen == 1) { 2982 match = (cmd->arg1 == x); 2983 break; 2984 } 2985 /* otherwise we have ranges */ 2986 p = ((ipfw_insn_u16 *)cmd)->ports; 2987 i = cmdlen - 1; 2988 for (; !match && i>0; i--, p += 2) 2989 match = (x >= p[0] && x <= p[1]); 2990 } 2991 break; 2992 2993 case O_IPPRECEDENCE: 2994 match = (is_ipv4 && 2995 (cmd->arg1 == (ip->ip_tos & 0xe0)) ); 2996 break; 2997 2998 case O_IPTOS: 2999 match = (is_ipv4 && 3000 flags_match(cmd, ip->ip_tos)); 3001 break; 3002 3003 case O_TCPDATALEN: 3004 if (proto == IPPROTO_TCP && offset == 0) { 3005 struct tcphdr *tcp; 3006 uint16_t x; 3007 uint16_t *p; 3008 int i; 3009 3010 tcp = TCP(ulp); 3011 x = ip_len - 3012 ((ip->ip_hl + tcp->th_off) << 2); 3013 if (cmdlen == 1) { 3014 match = (cmd->arg1 == x); 3015 break; 3016 } 3017 /* otherwise we have ranges */ 3018 p = ((ipfw_insn_u16 *)cmd)->ports; 3019 i = cmdlen - 1; 3020 for (; !match && i>0; i--, p += 2) 3021 match = (x >= p[0] && x <= p[1]); 3022 } 3023 break; 3024 3025 case O_TCPFLAGS: 3026 match = (proto == IPPROTO_TCP && offset == 0 && 3027 flags_match(cmd, TCP(ulp)->th_flags)); 3028 break; 3029 3030 case O_TCPOPTS: 3031 match = (proto == IPPROTO_TCP && offset == 0 && 3032 tcpopts_match(TCP(ulp), cmd)); 3033 break; 3034 3035 case O_TCPSEQ: 3036 match = (proto == IPPROTO_TCP && offset == 0 && 3037 ((ipfw_insn_u32 *)cmd)->d[0] == 3038 TCP(ulp)->th_seq); 3039 break; 3040 3041 case O_TCPACK: 3042 match = (proto == IPPROTO_TCP && offset == 0 && 3043 ((ipfw_insn_u32 *)cmd)->d[0] == 3044 TCP(ulp)->th_ack); 3045 break; 3046 3047 case O_TCPWIN: 3048 match = (proto == IPPROTO_TCP && offset == 0 && 3049 cmd->arg1 == TCP(ulp)->th_win); 3050 break; 3051 3052 case O_ESTAB: 3053 /* reject packets which have SYN only */ 3054 /* XXX should i also check for TH_ACK ? */ 3055 match = (proto == IPPROTO_TCP && offset == 0 && 3056 (TCP(ulp)->th_flags & 3057 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 3058 break; 3059 3060 case O_ALTQ: { 3061 struct altq_tag *at; 3062 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 3063 3064 match = 1; 3065 mtag = m_tag_find(m, PACKET_TAG_PF_QID, NULL); 3066 if (mtag != NULL) 3067 break; 3068 mtag = m_tag_get(PACKET_TAG_PF_QID, 3069 sizeof(struct altq_tag), 3070 M_NOWAIT); 3071 if (mtag == NULL) { 3072 /* 3073 * Let the packet fall back to the 3074 * default ALTQ. 3075 */ 3076 break; 3077 } 3078 at = (struct altq_tag *)(mtag+1); 3079 at->qid = altq->qid; 3080 if (is_ipv4) 3081 at->af = AF_INET; 3082 else 3083 at->af = AF_LINK; 3084 at->hdr = ip; 3085 m_tag_prepend(m, mtag); 3086 break; 3087 } 3088 3089 case O_LOG: 3090 if (fw_verbose) 3091 ipfw_log(f, hlen, args, m, 3092 oif, offset, tablearg, ip); 3093 match = 1; 3094 break; 3095 3096 case O_PROB: 3097 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 3098 break; 3099 3100 case O_VERREVPATH: 3101 /* Outgoing packets automatically pass/match */ 3102 match = ((oif != NULL) || 3103 (m->m_pkthdr.rcvif == NULL) || 3104 ( 3105#ifdef INET6 3106 is_ipv6 ? 3107 verify_path6(&(args->f_id.src_ip6), 3108 m->m_pkthdr.rcvif) : 3109#endif 3110 verify_path(src_ip, m->m_pkthdr.rcvif))); 3111 break; 3112 3113 case O_VERSRCREACH: 3114 /* Outgoing packets automatically pass/match */ 3115 match = (hlen > 0 && ((oif != NULL) || 3116#ifdef INET6 3117 is_ipv6 ? 3118 verify_path6(&(args->f_id.src_ip6), 3119 NULL) : 3120#endif 3121 verify_path(src_ip, NULL))); 3122 break; 3123 3124 case O_ANTISPOOF: 3125 /* Outgoing packets automatically pass/match */ 3126 if (oif == NULL && hlen > 0 && 3127 ( (is_ipv4 && in_localaddr(src_ip)) 3128#ifdef INET6 3129 || (is_ipv6 && 3130 in6_localaddr(&(args->f_id.src_ip6))) 3131#endif 3132 )) 3133 match = 3134#ifdef INET6 3135 is_ipv6 ? verify_path6( 3136 &(args->f_id.src_ip6), 3137 m->m_pkthdr.rcvif) : 3138#endif 3139 verify_path(src_ip, 3140 m->m_pkthdr.rcvif); 3141 else 3142 match = 1; 3143 break; 3144 3145 case O_IPSEC: 3146#ifdef FAST_IPSEC 3147 match = (m_tag_find(m, 3148 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 3149#endif 3150#ifdef IPSEC 3151 match = (ipsec_getnhist(m) != 0); 3152#endif 3153 /* otherwise no match */ 3154 break; 3155 3156#ifdef INET6 3157 case O_IP6_SRC: 3158 match = is_ipv6 && 3159 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 3160 &((ipfw_insn_ip6 *)cmd)->addr6); 3161 break; 3162 3163 case O_IP6_DST: 3164 match = is_ipv6 && 3165 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 3166 &((ipfw_insn_ip6 *)cmd)->addr6); 3167 break; 3168 case O_IP6_SRC_MASK: 3169 case O_IP6_DST_MASK: 3170 if (is_ipv6) { 3171 int i = cmdlen - 1; 3172 struct in6_addr p; 3173 struct in6_addr *d = 3174 &((ipfw_insn_ip6 *)cmd)->addr6; 3175 3176 for (; !match && i > 0; d += 2, 3177 i -= F_INSN_SIZE(struct in6_addr) 3178 * 2) { 3179 p = (cmd->opcode == 3180 O_IP6_SRC_MASK) ? 3181 args->f_id.src_ip6: 3182 args->f_id.dst_ip6; 3183 APPLY_MASK(&p, &d[1]); 3184 match = 3185 IN6_ARE_ADDR_EQUAL(&d[0], 3186 &p); 3187 } 3188 } 3189 break; 3190 3191 case O_IP6_SRC_ME: 3192 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6); 3193 break; 3194 3195 case O_IP6_DST_ME: 3196 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6); 3197 break; 3198 3199 case O_FLOW6ID: 3200 match = is_ipv6 && 3201 flow6id_match(args->f_id.flow_id6, 3202 (ipfw_insn_u32 *) cmd); 3203 break; 3204 3205 case O_EXT_HDR: 3206 match = is_ipv6 && 3207 (ext_hd & ((ipfw_insn *) cmd)->arg1); 3208 break; 3209 3210 case O_IP6: 3211 match = is_ipv6; 3212 break; 3213#endif 3214 3215 case O_IP4: 3216 match = is_ipv4; 3217 break; 3218 3219 case O_TAG: { 3220 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ? 3221 tablearg : cmd->arg1; 3222 3223 /* Packet is already tagged with this tag? */ 3224 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 3225 3226 /* We have `untag' action when F_NOT flag is 3227 * present. And we must remove this mtag from 3228 * mbuf and reset `match' to zero (`match' will 3229 * be inversed later). 3230 * Otherwise we should allocate new mtag and 3231 * push it into mbuf. 3232 */ 3233 if (cmd->len & F_NOT) { /* `untag' action */ 3234 if (mtag != NULL) 3235 m_tag_delete(m, mtag); 3236 } else if (mtag == NULL) { 3237 if ((mtag = m_tag_alloc(MTAG_IPFW, 3238 tag, 0, M_NOWAIT)) != NULL) 3239 m_tag_prepend(m, mtag); 3240 } 3241 match = (cmd->len & F_NOT) ? 0: 1; 3242 break; 3243 } 3244 3245 case O_TAGGED: { 3246 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ? 3247 tablearg : cmd->arg1; 3248 3249 if (cmdlen == 1) { 3250 match = m_tag_locate(m, MTAG_IPFW, 3251 tag, NULL) != NULL; 3252 break; 3253 } 3254 3255 /* we have ranges */ 3256 for (mtag = m_tag_first(m); 3257 mtag != NULL && !match; 3258 mtag = m_tag_next(m, mtag)) { 3259 uint16_t *p; 3260 int i; 3261 3262 if (mtag->m_tag_cookie != MTAG_IPFW) 3263 continue; 3264 3265 p = ((ipfw_insn_u16 *)cmd)->ports; 3266 i = cmdlen - 1; 3267 for(; !match && i > 0; i--, p += 2) 3268 match = 3269 mtag->m_tag_id >= p[0] && 3270 mtag->m_tag_id <= p[1]; 3271 } 3272 break; 3273 } 3274 3275 /* 3276 * The second set of opcodes represents 'actions', 3277 * i.e. the terminal part of a rule once the packet 3278 * matches all previous patterns. 3279 * Typically there is only one action for each rule, 3280 * and the opcode is stored at the end of the rule 3281 * (but there are exceptions -- see below). 3282 * 3283 * In general, here we set retval and terminate the 3284 * outer loop (would be a 'break 3' in some language, 3285 * but we need to do a 'goto done'). 3286 * 3287 * Exceptions: 3288 * O_COUNT and O_SKIPTO actions: 3289 * instead of terminating, we jump to the next rule 3290 * ('goto next_rule', equivalent to a 'break 2'), 3291 * or to the SKIPTO target ('goto again' after 3292 * having set f, cmd and l), respectively. 3293 * 3294 * O_TAG, O_LOG and O_ALTQ action parameters: 3295 * perform some action and set match = 1; 3296 * 3297 * O_LIMIT and O_KEEP_STATE: these opcodes are 3298 * not real 'actions', and are stored right 3299 * before the 'action' part of the rule. 3300 * These opcodes try to install an entry in the 3301 * state tables; if successful, we continue with 3302 * the next opcode (match=1; break;), otherwise 3303 * the packet * must be dropped 3304 * ('goto done' after setting retval); 3305 * 3306 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 3307 * cause a lookup of the state table, and a jump 3308 * to the 'action' part of the parent rule 3309 * ('goto check_body') if an entry is found, or 3310 * (CHECK_STATE only) a jump to the next rule if 3311 * the entry is not found ('goto next_rule'). 3312 * The result of the lookup is cached to make 3313 * further instances of these opcodes are 3314 * effectively NOPs. 3315 */ 3316 case O_LIMIT: 3317 case O_KEEP_STATE: 3318 if (install_state(f, 3319 (ipfw_insn_limit *)cmd, args, tablearg)) { 3320 retval = IP_FW_DENY; 3321 goto done; /* error/limit violation */ 3322 } 3323 match = 1; 3324 break; 3325 3326 case O_PROBE_STATE: 3327 case O_CHECK_STATE: 3328 /* 3329 * dynamic rules are checked at the first 3330 * keep-state or check-state occurrence, 3331 * with the result being stored in dyn_dir. 3332 * The compiler introduces a PROBE_STATE 3333 * instruction for us when we have a 3334 * KEEP_STATE (because PROBE_STATE needs 3335 * to be run first). 3336 */ 3337 if (dyn_dir == MATCH_UNKNOWN && 3338 (q = lookup_dyn_rule(&args->f_id, 3339 &dyn_dir, proto == IPPROTO_TCP ? 3340 TCP(ulp) : NULL)) 3341 != NULL) { 3342 /* 3343 * Found dynamic entry, update stats 3344 * and jump to the 'action' part of 3345 * the parent rule. 3346 */ 3347 q->pcnt++; 3348 q->bcnt += pktlen; 3349 f = q->rule; 3350 cmd = ACTION_PTR(f); 3351 l = f->cmd_len - f->act_ofs; 3352 IPFW_DYN_UNLOCK(); 3353 goto check_body; 3354 } 3355 /* 3356 * Dynamic entry not found. If CHECK_STATE, 3357 * skip to next rule, if PROBE_STATE just 3358 * ignore and continue with next opcode. 3359 */ 3360 if (cmd->opcode == O_CHECK_STATE) 3361 goto next_rule; 3362 match = 1; 3363 break; 3364 3365 case O_ACCEPT: 3366 retval = 0; /* accept */ 3367 goto done; 3368 3369 case O_PIPE: 3370 case O_QUEUE: 3371 args->rule = f; /* report matching rule */ 3372 if (cmd->arg1 == IP_FW_TABLEARG) 3373 args->cookie = tablearg; 3374 else 3375 args->cookie = cmd->arg1; 3376 retval = IP_FW_DUMMYNET; 3377 goto done; 3378 3379 case O_DIVERT: 3380 case O_TEE: { 3381 struct divert_tag *dt; 3382 3383 if (args->eh) /* not on layer 2 */ 3384 break; 3385 mtag = m_tag_get(PACKET_TAG_DIVERT, 3386 sizeof(struct divert_tag), 3387 M_NOWAIT); 3388 if (mtag == NULL) { 3389 /* XXX statistic */ 3390 /* drop packet */ 3391 IPFW_RUNLOCK(chain); 3392 return (IP_FW_DENY); 3393 } 3394 dt = (struct divert_tag *)(mtag+1); 3395 dt->cookie = f->rulenum; 3396 if (cmd->arg1 == IP_FW_TABLEARG) 3397 dt->info = tablearg; 3398 else 3399 dt->info = cmd->arg1; 3400 m_tag_prepend(m, mtag); 3401 retval = (cmd->opcode == O_DIVERT) ? 3402 IP_FW_DIVERT : IP_FW_TEE; 3403 goto done; 3404 } 3405 3406 case O_COUNT: 3407 case O_SKIPTO: 3408 f->pcnt++; /* update stats */ 3409 f->bcnt += pktlen; 3410 f->timestamp = time_uptime; 3411 if (cmd->opcode == O_COUNT) 3412 goto next_rule; 3413 /* handle skipto */ 3414 if (f->next_rule == NULL) 3415 lookup_next_rule(f); 3416 f = f->next_rule; 3417 goto again; 3418 3419 case O_REJECT: 3420 /* 3421 * Drop the packet and send a reject notice 3422 * if the packet is not ICMP (or is an ICMP 3423 * query), and it is not multicast/broadcast. 3424 */ 3425 if (hlen > 0 && is_ipv4 && offset == 0 && 3426 (proto != IPPROTO_ICMP || 3427 is_icmp_query(ICMP(ulp))) && 3428 !(m->m_flags & (M_BCAST|M_MCAST)) && 3429 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 3430 send_reject(args, cmd->arg1, ip_len, ip); 3431 m = args->m; 3432 } 3433 /* FALLTHROUGH */ 3434#ifdef INET6 3435 case O_UNREACH6: 3436 if (hlen > 0 && is_ipv6 && 3437 ((offset & IP6F_OFF_MASK) == 0) && 3438 (proto != IPPROTO_ICMPV6 || 3439 (is_icmp6_query(args->f_id.flags) == 1)) && 3440 !(m->m_flags & (M_BCAST|M_MCAST)) && 3441 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 3442 send_reject6( 3443 args, cmd->arg1, hlen, 3444 (struct ip6_hdr *)ip); 3445 m = args->m; 3446 } 3447 /* FALLTHROUGH */ 3448#endif 3449 case O_DENY: 3450 retval = IP_FW_DENY; 3451 goto done; 3452 3453 case O_FORWARD_IP: { 3454 struct sockaddr_in *sa; 3455 sa = &(((ipfw_insn_sa *)cmd)->sa); 3456 if (args->eh) /* not valid on layer2 pkts */ 3457 break; 3458 if (!q || dyn_dir == MATCH_FORWARD) { 3459 if (sa->sin_addr.s_addr == INADDR_ANY) { 3460 bcopy(sa, &args->hopstore, 3461 sizeof(*sa)); 3462 args->hopstore.sin_addr.s_addr = 3463 htonl(tablearg); 3464 args->next_hop = 3465 &args->hopstore; 3466 } else { 3467 args->next_hop = sa; 3468 } 3469 } 3470 retval = IP_FW_PASS; 3471 } 3472 goto done; 3473 3474 case O_NETGRAPH: 3475 case O_NGTEE: 3476 args->rule = f; /* report matching rule */ 3477 if (cmd->arg1 == IP_FW_TABLEARG) 3478 args->cookie = tablearg; 3479 else 3480 args->cookie = cmd->arg1; 3481 retval = (cmd->opcode == O_NETGRAPH) ? 3482 IP_FW_NETGRAPH : IP_FW_NGTEE; 3483 goto done; 3484 3485#ifdef IPFIREWALL_NAT 3486 case O_NAT: { 3487 struct cfg_nat *t; 3488 struct mbuf *mcl; 3489 /* XXX - libalias duct tape */ 3490 int ldt; 3491 char *c; 3492 3493 ldt = 0; 3494 args->rule = f; /* Report matching rule. */ 3495 retval = 0; 3496 t = ((ipfw_insn_nat *)cmd)->nat; 3497 if (t == NULL) { 3498 t = lookup_nat(cmd->arg1); 3499 if (t == NULL) { 3500 retval = IP_FW_DENY; 3501 goto done; 3502 } else 3503 ((ipfw_insn_nat *)cmd)->nat = 3504 t; 3505 } 3506 if ((mcl = m_megapullup(m, m->m_pkthdr.len)) == 3507 NULL) 3508 goto badnat; 3509 ip = mtod(mcl, struct ip *); 3510 if (args->eh == NULL) { 3511 ip->ip_len = htons(ip->ip_len); 3512 ip->ip_off = htons(ip->ip_off); 3513 } 3514 3515 /* 3516 * XXX - Libalias checksum offload 'duct tape': 3517 * 3518 * locally generated packets have only 3519 * pseudo-header checksum calculated 3520 * and libalias will screw it[1], so 3521 * mark them for later fix. Moreover 3522 * there are cases when libalias 3523 * modify tcp packet data[2], mark it 3524 * for later fix too. 3525 * 3526 * [1] libalias was never meant to run 3527 * in kernel, so it doesn't have any 3528 * knowledge about checksum 3529 * offloading, and it expects a packet 3530 * with a full internet 3531 * checksum. Unfortunately, packets 3532 * generated locally will have just the 3533 * pseudo header calculated, and when 3534 * libalias tries to adjust the 3535 * checksum it will actually screw it. 3536 * 3537 * [2] when libalias modify tcp's data 3538 * content, full TCP checksum has to 3539 * be recomputed: the problem is that 3540 * libalias doesn't have any idea 3541 * about checksum offloading To 3542 * workaround this, we do not do 3543 * checksumming in LibAlias, but only 3544 * mark the packets in th_x2 field. If 3545 * we receive a marked packet, we 3546 * calculate correct checksum for it 3547 * aware of offloading. Why such a 3548 * terrible hack instead of 3549 * recalculating checksum for each 3550 * packet? Because the previous 3551 * checksum was not checked! 3552 * Recalculating checksums for EVERY 3553 * packet will hide ALL transmission 3554 * errors. Yes, marked packets still 3555 * suffer from this problem. But, 3556 * sigh, natd(8) has this problem, 3557 * too. 3558 * 3559 * TODO: -make libalias mbuf aware (so 3560 * it can handle delayed checksum and tso) 3561 */ 3562 3563 if (mcl->m_pkthdr.rcvif == NULL && 3564 mcl->m_pkthdr.csum_flags & 3565 CSUM_DELAY_DATA) 3566 ldt = 1; 3567 3568 c = mtod(mcl, char *); 3569 if (oif == NULL) 3570 retval = LibAliasIn(t->lib, c, 3571 MCLBYTES); 3572 else 3573 retval = LibAliasOut(t->lib, c, 3574 MCLBYTES); 3575 if (retval != PKT_ALIAS_OK) { 3576 /* XXX - should i add some logging? */ 3577 m_free(mcl); 3578 badnat: 3579 args->m = NULL; 3580 retval = IP_FW_DENY; 3581 goto done; 3582 } 3583 mcl->m_pkthdr.len = mcl->m_len = 3584 ntohs(ip->ip_len); 3585 3586 /* 3587 * XXX - libalias checksum offload 3588 * 'duct tape' (see above) 3589 */ 3590 3591 if ((ip->ip_off & htons(IP_OFFMASK)) == 0 && 3592 ip->ip_p == IPPROTO_TCP) { 3593 struct tcphdr *th; 3594 3595 th = (struct tcphdr *)(ip + 1); 3596 if (th->th_x2) 3597 ldt = 1; 3598 } 3599 3600 if (ldt) { 3601 struct tcphdr *th; 3602 struct udphdr *uh; 3603 u_short cksum; 3604 3605 ip->ip_len = ntohs(ip->ip_len); 3606 cksum = in_pseudo( 3607 ip->ip_src.s_addr, 3608 ip->ip_dst.s_addr, 3609 htons(ip->ip_p + ip->ip_len - 3610 (ip->ip_hl << 2)) 3611 ); 3612 3613 switch (ip->ip_p) { 3614 case IPPROTO_TCP: 3615 th = (struct tcphdr *)(ip + 1); 3616 /* 3617 * Maybe it was set in 3618 * libalias... 3619 */ 3620 th->th_x2 = 0; 3621 th->th_sum = cksum; 3622 mcl->m_pkthdr.csum_data = 3623 offsetof(struct tcphdr, 3624 th_sum); 3625 break; 3626 case IPPROTO_UDP: 3627 uh = (struct udphdr *)(ip + 1); 3628 uh->uh_sum = cksum; 3629 mcl->m_pkthdr.csum_data = 3630 offsetof(struct udphdr, 3631 uh_sum); 3632 break; 3633 } 3634 /* 3635 * No hw checksum offloading: do it 3636 * by ourself. 3637 */ 3638 if ((mcl->m_pkthdr.csum_flags & 3639 CSUM_DELAY_DATA) == 0) { 3640 in_delayed_cksum(mcl); 3641 mcl->m_pkthdr.csum_flags &= 3642 ~CSUM_DELAY_DATA; 3643 } 3644 ip->ip_len = htons(ip->ip_len); 3645 } 3646 3647 if (args->eh == NULL) { 3648 ip->ip_len = ntohs(ip->ip_len); 3649 ip->ip_off = ntohs(ip->ip_off); 3650 } 3651 3652 args->m = mcl; 3653 retval = IP_FW_NAT; 3654 goto done; 3655 } 3656#endif 3657 3658 default: 3659 panic("-- unknown opcode %d\n", cmd->opcode); 3660 } /* end of switch() on opcodes */ 3661 3662 if (cmd->len & F_NOT) 3663 match = !match; 3664 3665 if (match) { 3666 if (cmd->len & F_OR) 3667 skip_or = 1; 3668 } else { 3669 if (!(cmd->len & F_OR)) /* not an OR block, */ 3670 break; /* try next rule */ 3671 } 3672 3673 } /* end of inner for, scan opcodes */ 3674 3675next_rule:; /* try next rule */ 3676 3677 } /* end of outer for, scan rules */ 3678 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 3679 IPFW_RUNLOCK(chain); 3680 return (IP_FW_DENY); 3681 3682done: 3683 /* Update statistics */ 3684 f->pcnt++; 3685 f->bcnt += pktlen; 3686 f->timestamp = time_uptime; 3687 IPFW_RUNLOCK(chain); 3688 return (retval); 3689 3690pullup_failed: 3691 if (fw_verbose) 3692 printf("ipfw: pullup failed\n"); 3693 return (IP_FW_DENY); 3694} 3695 3696/* 3697 * When a rule is added/deleted, clear the next_rule pointers in all rules. 3698 * These will be reconstructed on the fly as packets are matched. 3699 */ 3700static void 3701flush_rule_ptrs(struct ip_fw_chain *chain) 3702{ 3703 struct ip_fw *rule; 3704 3705 IPFW_WLOCK_ASSERT(chain); 3706 3707 for (rule = chain->rules; rule; rule = rule->next) 3708 rule->next_rule = NULL; 3709} 3710 3711/* 3712 * Add a new rule to the list. Copy the rule into a malloc'ed area, then 3713 * possibly create a rule number and add the rule to the list. 3714 * Update the rule_number in the input struct so the caller knows it as well. 3715 */ 3716static int 3717add_rule(struct ip_fw_chain *chain, struct ip_fw *input_rule) 3718{ 3719 struct ip_fw *rule, *f, *prev; 3720 int l = RULESIZE(input_rule); 3721 3722 if (chain->rules == NULL && input_rule->rulenum != IPFW_DEFAULT_RULE) 3723 return (EINVAL); 3724 3725 rule = malloc(l, M_IPFW, M_NOWAIT | M_ZERO); 3726 if (rule == NULL) 3727 return (ENOSPC); 3728 3729 bcopy(input_rule, rule, l); 3730 3731 rule->next = NULL; 3732 rule->next_rule = NULL; 3733 3734 rule->pcnt = 0; 3735 rule->bcnt = 0; 3736 rule->timestamp = 0; 3737 3738 IPFW_WLOCK(chain); 3739 3740 if (chain->rules == NULL) { /* default rule */ 3741 chain->rules = rule; 3742 goto done; 3743 } 3744 3745 /* 3746 * If rulenum is 0, find highest numbered rule before the 3747 * default rule, and add autoinc_step 3748 */ 3749 if (autoinc_step < 1) 3750 autoinc_step = 1; 3751 else if (autoinc_step > 1000) 3752 autoinc_step = 1000; 3753 if (rule->rulenum == 0) { 3754 /* 3755 * locate the highest numbered rule before default 3756 */ 3757 for (f = chain->rules; f; f = f->next) { 3758 if (f->rulenum == IPFW_DEFAULT_RULE) 3759 break; 3760 rule->rulenum = f->rulenum; 3761 } 3762 if (rule->rulenum < IPFW_DEFAULT_RULE - autoinc_step) 3763 rule->rulenum += autoinc_step; 3764 input_rule->rulenum = rule->rulenum; 3765 } 3766 3767 /* 3768 * Now insert the new rule in the right place in the sorted list. 3769 */ 3770 for (prev = NULL, f = chain->rules; f; prev = f, f = f->next) { 3771 if (f->rulenum > rule->rulenum) { /* found the location */ 3772 if (prev) { 3773 rule->next = f; 3774 prev->next = rule; 3775 } else { /* head insert */ 3776 rule->next = chain->rules; 3777 chain->rules = rule; 3778 } 3779 break; 3780 } 3781 } 3782 flush_rule_ptrs(chain); 3783done: 3784 static_count++; 3785 static_len += l; 3786 IPFW_WUNLOCK(chain); 3787 DEB(printf("ipfw: installed rule %d, static count now %d\n", 3788 rule->rulenum, static_count);) 3789 return (0); 3790} 3791 3792/** 3793 * Remove a static rule (including derived * dynamic rules) 3794 * and place it on the ``reap list'' for later reclamation. 3795 * The caller is in charge of clearing rule pointers to avoid 3796 * dangling pointers. 3797 * @return a pointer to the next entry. 3798 * Arguments are not checked, so they better be correct. 3799 */ 3800static struct ip_fw * 3801remove_rule(struct ip_fw_chain *chain, struct ip_fw *rule, struct ip_fw *prev) 3802{ 3803 struct ip_fw *n; 3804 int l = RULESIZE(rule); 3805 3806 IPFW_WLOCK_ASSERT(chain); 3807 3808 n = rule->next; 3809 IPFW_DYN_LOCK(); 3810 remove_dyn_rule(rule, NULL /* force removal */); 3811 IPFW_DYN_UNLOCK(); 3812 if (prev == NULL) 3813 chain->rules = n; 3814 else 3815 prev->next = n; 3816 static_count--; 3817 static_len -= l; 3818 3819 rule->next = chain->reap; 3820 chain->reap = rule; 3821 3822 return n; 3823} 3824 3825/** 3826 * Reclaim storage associated with a list of rules. This is 3827 * typically the list created using remove_rule. 3828 */ 3829static void 3830reap_rules(struct ip_fw *head) 3831{ 3832 struct ip_fw *rule; 3833 3834 while ((rule = head) != NULL) { 3835 head = head->next; 3836 if (DUMMYNET_LOADED) 3837 ip_dn_ruledel_ptr(rule); 3838 free(rule, M_IPFW); 3839 } 3840} 3841 3842/* 3843 * Remove all rules from a chain (except rules in set RESVD_SET 3844 * unless kill_default = 1). The caller is responsible for 3845 * reclaiming storage for the rules left in chain->reap. 3846 */ 3847static void 3848free_chain(struct ip_fw_chain *chain, int kill_default) 3849{ 3850 struct ip_fw *prev, *rule; 3851 3852 IPFW_WLOCK_ASSERT(chain); 3853 3854 flush_rule_ptrs(chain); /* more efficient to do outside the loop */ 3855 for (prev = NULL, rule = chain->rules; rule ; ) 3856 if (kill_default || rule->set != RESVD_SET) 3857 rule = remove_rule(chain, rule, prev); 3858 else { 3859 prev = rule; 3860 rule = rule->next; 3861 } 3862} 3863 3864/** 3865 * Remove all rules with given number, and also do set manipulation. 3866 * Assumes chain != NULL && *chain != NULL. 3867 * 3868 * The argument is an u_int32_t. The low 16 bit are the rule or set number, 3869 * the next 8 bits are the new set, the top 8 bits are the command: 3870 * 3871 * 0 delete rules with given number 3872 * 1 delete rules with given set number 3873 * 2 move rules with given number to new set 3874 * 3 move rules with given set number to new set 3875 * 4 swap sets with given numbers 3876 */ 3877static int 3878del_entry(struct ip_fw_chain *chain, u_int32_t arg) 3879{ 3880 struct ip_fw *prev = NULL, *rule; 3881 u_int16_t rulenum; /* rule or old_set */ 3882 u_int8_t cmd, new_set; 3883 3884 rulenum = arg & 0xffff; 3885 cmd = (arg >> 24) & 0xff; 3886 new_set = (arg >> 16) & 0xff; 3887 3888 if (cmd > 4) 3889 return EINVAL; 3890 if (new_set > RESVD_SET) 3891 return EINVAL; 3892 if (cmd == 0 || cmd == 2) { 3893 if (rulenum >= IPFW_DEFAULT_RULE) 3894 return EINVAL; 3895 } else { 3896 if (rulenum > RESVD_SET) /* old_set */ 3897 return EINVAL; 3898 } 3899 3900 IPFW_WLOCK(chain); 3901 rule = chain->rules; 3902 chain->reap = NULL; 3903 switch (cmd) { 3904 case 0: /* delete rules with given number */ 3905 /* 3906 * locate first rule to delete 3907 */ 3908 for (; rule->rulenum < rulenum; prev = rule, rule = rule->next) 3909 ; 3910 if (rule->rulenum != rulenum) { 3911 IPFW_WUNLOCK(chain); 3912 return EINVAL; 3913 } 3914 3915 /* 3916 * flush pointers outside the loop, then delete all matching 3917 * rules. prev remains the same throughout the cycle. 3918 */ 3919 flush_rule_ptrs(chain); 3920 while (rule->rulenum == rulenum) 3921 rule = remove_rule(chain, rule, prev); 3922 break; 3923 3924 case 1: /* delete all rules with given set number */ 3925 flush_rule_ptrs(chain); 3926 rule = chain->rules; 3927 while (rule->rulenum < IPFW_DEFAULT_RULE) 3928 if (rule->set == rulenum) 3929 rule = remove_rule(chain, rule, prev); 3930 else { 3931 prev = rule; 3932 rule = rule->next; 3933 } 3934 break; 3935 3936 case 2: /* move rules with given number to new set */ 3937 rule = chain->rules; 3938 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3939 if (rule->rulenum == rulenum) 3940 rule->set = new_set; 3941 break; 3942 3943 case 3: /* move rules with given set number to new set */ 3944 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3945 if (rule->set == rulenum) 3946 rule->set = new_set; 3947 break; 3948 3949 case 4: /* swap two sets */ 3950 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3951 if (rule->set == rulenum) 3952 rule->set = new_set; 3953 else if (rule->set == new_set) 3954 rule->set = rulenum; 3955 break; 3956 } 3957 /* 3958 * Look for rules to reclaim. We grab the list before 3959 * releasing the lock then reclaim them w/o the lock to 3960 * avoid a LOR with dummynet. 3961 */ 3962 rule = chain->reap; 3963 chain->reap = NULL; 3964 IPFW_WUNLOCK(chain); 3965 if (rule) 3966 reap_rules(rule); 3967 return 0; 3968} 3969 3970/* 3971 * Clear counters for a specific rule. 3972 * The enclosing "table" is assumed locked. 3973 */ 3974static void 3975clear_counters(struct ip_fw *rule, int log_only) 3976{ 3977 ipfw_insn_log *l = (ipfw_insn_log *)ACTION_PTR(rule); 3978 3979 if (log_only == 0) { 3980 rule->bcnt = rule->pcnt = 0; 3981 rule->timestamp = 0; 3982 } 3983 if (l->o.opcode == O_LOG) 3984 l->log_left = l->max_log; 3985} 3986 3987/** 3988 * Reset some or all counters on firewall rules. 3989 * @arg frwl is null to clear all entries, or contains a specific 3990 * rule number. 3991 * @arg log_only is 1 if we only want to reset logs, zero otherwise. 3992 */ 3993static int 3994zero_entry(struct ip_fw_chain *chain, int rulenum, int log_only) 3995{ 3996 struct ip_fw *rule; 3997 char *msg; 3998 3999 IPFW_WLOCK(chain); 4000 if (rulenum == 0) { 4001 norule_counter = 0; 4002 for (rule = chain->rules; rule; rule = rule->next) 4003 clear_counters(rule, log_only); 4004 msg = log_only ? "ipfw: All logging counts reset.\n" : 4005 "ipfw: Accounting cleared.\n"; 4006 } else { 4007 int cleared = 0; 4008 /* 4009 * We can have multiple rules with the same number, so we 4010 * need to clear them all. 4011 */ 4012 for (rule = chain->rules; rule; rule = rule->next) 4013 if (rule->rulenum == rulenum) { 4014 while (rule && rule->rulenum == rulenum) { 4015 clear_counters(rule, log_only); 4016 rule = rule->next; 4017 } 4018 cleared = 1; 4019 break; 4020 } 4021 if (!cleared) { /* we did not find any matching rules */ 4022 IPFW_WUNLOCK(chain); 4023 return (EINVAL); 4024 } 4025 msg = log_only ? "ipfw: Entry %d logging count reset.\n" : 4026 "ipfw: Entry %d cleared.\n"; 4027 } 4028 IPFW_WUNLOCK(chain); 4029 4030 if (fw_verbose) 4031 log(LOG_SECURITY | LOG_NOTICE, msg, rulenum); 4032 return (0); 4033} 4034 4035/* 4036 * Check validity of the structure before insert. 4037 * Fortunately rules are simple, so this mostly need to check rule sizes. 4038 */ 4039static int 4040check_ipfw_struct(struct ip_fw *rule, int size) 4041{ 4042 int l, cmdlen = 0; 4043 int have_action=0; 4044 ipfw_insn *cmd; 4045 4046 if (size < sizeof(*rule)) { 4047 printf("ipfw: rule too short\n"); 4048 return (EINVAL); 4049 } 4050 /* first, check for valid size */ 4051 l = RULESIZE(rule); 4052 if (l != size) { 4053 printf("ipfw: size mismatch (have %d want %d)\n", size, l); 4054 return (EINVAL); 4055 } 4056 if (rule->act_ofs >= rule->cmd_len) { 4057 printf("ipfw: bogus action offset (%u > %u)\n", 4058 rule->act_ofs, rule->cmd_len - 1); 4059 return (EINVAL); 4060 } 4061 /* 4062 * Now go for the individual checks. Very simple ones, basically only 4063 * instruction sizes. 4064 */ 4065 for (l = rule->cmd_len, cmd = rule->cmd ; 4066 l > 0 ; l -= cmdlen, cmd += cmdlen) { 4067 cmdlen = F_LEN(cmd); 4068 if (cmdlen > l) { 4069 printf("ipfw: opcode %d size truncated\n", 4070 cmd->opcode); 4071 return EINVAL; 4072 } 4073 DEB(printf("ipfw: opcode %d\n", cmd->opcode);) 4074 switch (cmd->opcode) { 4075 case O_PROBE_STATE: 4076 case O_KEEP_STATE: 4077 case O_PROTO: 4078 case O_IP_SRC_ME: 4079 case O_IP_DST_ME: 4080 case O_LAYER2: 4081 case O_IN: 4082 case O_FRAG: 4083 case O_DIVERTED: 4084 case O_IPOPT: 4085 case O_IPTOS: 4086 case O_IPPRECEDENCE: 4087 case O_IPVER: 4088 case O_TCPWIN: 4089 case O_TCPFLAGS: 4090 case O_TCPOPTS: 4091 case O_ESTAB: 4092 case O_VERREVPATH: 4093 case O_VERSRCREACH: 4094 case O_ANTISPOOF: 4095 case O_IPSEC: 4096#ifdef INET6 4097 case O_IP6_SRC_ME: 4098 case O_IP6_DST_ME: 4099 case O_EXT_HDR: 4100 case O_IP6: 4101#endif 4102 case O_IP4: 4103 case O_TAG: 4104 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 4105 goto bad_size; 4106 break; 4107 4108 case O_UID: 4109 case O_GID: 4110 case O_JAIL: 4111 case O_IP_SRC: 4112 case O_IP_DST: 4113 case O_TCPSEQ: 4114 case O_TCPACK: 4115 case O_PROB: 4116 case O_ICMPTYPE: 4117 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32)) 4118 goto bad_size; 4119 break; 4120 4121 case O_LIMIT: 4122 if (cmdlen != F_INSN_SIZE(ipfw_insn_limit)) 4123 goto bad_size; 4124 break; 4125 4126 case O_LOG: 4127 if (cmdlen != F_INSN_SIZE(ipfw_insn_log)) 4128 goto bad_size; 4129 4130 ((ipfw_insn_log *)cmd)->log_left = 4131 ((ipfw_insn_log *)cmd)->max_log; 4132 4133 break; 4134 4135 case O_IP_SRC_MASK: 4136 case O_IP_DST_MASK: 4137 /* only odd command lengths */ 4138 if ( !(cmdlen & 1) || cmdlen > 31) 4139 goto bad_size; 4140 break; 4141 4142 case O_IP_SRC_SET: 4143 case O_IP_DST_SET: 4144 if (cmd->arg1 == 0 || cmd->arg1 > 256) { 4145 printf("ipfw: invalid set size %d\n", 4146 cmd->arg1); 4147 return EINVAL; 4148 } 4149 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) + 4150 (cmd->arg1+31)/32 ) 4151 goto bad_size; 4152 break; 4153 4154 case O_IP_SRC_LOOKUP: 4155 case O_IP_DST_LOOKUP: 4156 if (cmd->arg1 >= IPFW_TABLES_MAX) { 4157 printf("ipfw: invalid table number %d\n", 4158 cmd->arg1); 4159 return (EINVAL); 4160 } 4161 if (cmdlen != F_INSN_SIZE(ipfw_insn) && 4162 cmdlen != F_INSN_SIZE(ipfw_insn_u32)) 4163 goto bad_size; 4164 break; 4165 4166 case O_MACADDR2: 4167 if (cmdlen != F_INSN_SIZE(ipfw_insn_mac)) 4168 goto bad_size; 4169 break; 4170 4171 case O_NOP: 4172 case O_IPID: 4173 case O_IPTTL: 4174 case O_IPLEN: 4175 case O_TCPDATALEN: 4176 case O_TAGGED: 4177 if (cmdlen < 1 || cmdlen > 31) 4178 goto bad_size; 4179 break; 4180 4181 case O_MAC_TYPE: 4182 case O_IP_SRCPORT: 4183 case O_IP_DSTPORT: /* XXX artificial limit, 30 port pairs */ 4184 if (cmdlen < 2 || cmdlen > 31) 4185 goto bad_size; 4186 break; 4187 4188 case O_RECV: 4189 case O_XMIT: 4190 case O_VIA: 4191 if (cmdlen != F_INSN_SIZE(ipfw_insn_if)) 4192 goto bad_size; 4193 break; 4194 4195 case O_ALTQ: 4196 if (cmdlen != F_INSN_SIZE(ipfw_insn_altq)) 4197 goto bad_size; 4198 break; 4199 4200 case O_PIPE: 4201 case O_QUEUE: 4202 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 4203 goto bad_size; 4204 goto check_action; 4205 4206 case O_FORWARD_IP: 4207#ifdef IPFIREWALL_FORWARD 4208 if (cmdlen != F_INSN_SIZE(ipfw_insn_sa)) 4209 goto bad_size; 4210 goto check_action; 4211#else 4212 return EINVAL; 4213#endif 4214 4215 case O_DIVERT: 4216 case O_TEE: 4217 if (ip_divert_ptr == NULL) 4218 return EINVAL; 4219 else 4220 goto check_size; 4221 case O_NETGRAPH: 4222 case O_NGTEE: 4223 if (!NG_IPFW_LOADED) 4224 return EINVAL; 4225 else 4226 goto check_size; 4227 case O_NAT: 4228#ifdef IPFIREWALL_NAT 4229 if (cmdlen != F_INSN_SIZE(ipfw_insn_nat)) 4230 goto bad_size; 4231 goto check_action; 4232#else 4233 return EINVAL; 4234#endif 4235 case O_FORWARD_MAC: /* XXX not implemented yet */ 4236 case O_CHECK_STATE: 4237 case O_COUNT: 4238 case O_ACCEPT: 4239 case O_DENY: 4240 case O_REJECT: 4241#ifdef INET6 4242 case O_UNREACH6: 4243#endif 4244 case O_SKIPTO: 4245check_size: 4246 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 4247 goto bad_size; 4248check_action: 4249 if (have_action) { 4250 printf("ipfw: opcode %d, multiple actions" 4251 " not allowed\n", 4252 cmd->opcode); 4253 return EINVAL; 4254 } 4255 have_action = 1; 4256 if (l != cmdlen) { 4257 printf("ipfw: opcode %d, action must be" 4258 " last opcode\n", 4259 cmd->opcode); 4260 return EINVAL; 4261 } 4262 break; 4263#ifdef INET6 4264 case O_IP6_SRC: 4265 case O_IP6_DST: 4266 if (cmdlen != F_INSN_SIZE(struct in6_addr) + 4267 F_INSN_SIZE(ipfw_insn)) 4268 goto bad_size; 4269 break; 4270 4271 case O_FLOW6ID: 4272 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) + 4273 ((ipfw_insn_u32 *)cmd)->o.arg1) 4274 goto bad_size; 4275 break; 4276 4277 case O_IP6_SRC_MASK: 4278 case O_IP6_DST_MASK: 4279 if ( !(cmdlen & 1) || cmdlen > 127) 4280 goto bad_size; 4281 break; 4282 case O_ICMP6TYPE: 4283 if( cmdlen != F_INSN_SIZE( ipfw_insn_icmp6 ) ) 4284 goto bad_size; 4285 break; 4286#endif 4287 4288 default: 4289 switch (cmd->opcode) { 4290#ifndef INET6 4291 case O_IP6_SRC_ME: 4292 case O_IP6_DST_ME: 4293 case O_EXT_HDR: 4294 case O_IP6: 4295 case O_UNREACH6: 4296 case O_IP6_SRC: 4297 case O_IP6_DST: 4298 case O_FLOW6ID: 4299 case O_IP6_SRC_MASK: 4300 case O_IP6_DST_MASK: 4301 case O_ICMP6TYPE: 4302 printf("ipfw: no IPv6 support in kernel\n"); 4303 return EPROTONOSUPPORT; 4304#endif 4305 default: 4306 printf("ipfw: opcode %d, unknown opcode\n", 4307 cmd->opcode); 4308 return EINVAL; 4309 } 4310 } 4311 } 4312 if (have_action == 0) { 4313 printf("ipfw: missing action\n"); 4314 return EINVAL; 4315 } 4316 return 0; 4317 4318bad_size: 4319 printf("ipfw: opcode %d size %d wrong\n", 4320 cmd->opcode, cmdlen); 4321 return EINVAL; 4322} 4323 4324/* 4325 * Copy the static and dynamic rules to the supplied buffer 4326 * and return the amount of space actually used. 4327 */ 4328static size_t 4329ipfw_getrules(struct ip_fw_chain *chain, void *buf, size_t space) 4330{ 4331 char *bp = buf; 4332 char *ep = bp + space; 4333 struct ip_fw *rule; 4334 int i; 4335 time_t boot_seconds; 4336 4337 boot_seconds = boottime.tv_sec; 4338 /* XXX this can take a long time and locking will block packet flow */ 4339 IPFW_RLOCK(chain); 4340 for (rule = chain->rules; rule ; rule = rule->next) { 4341 /* 4342 * Verify the entry fits in the buffer in case the 4343 * rules changed between calculating buffer space and 4344 * now. This would be better done using a generation 4345 * number but should suffice for now. 4346 */ 4347 i = RULESIZE(rule); 4348 if (bp + i <= ep) { 4349 bcopy(rule, bp, i); 4350 /* 4351 * XXX HACK. Store the disable mask in the "next" pointer 4352 * in a wild attempt to keep the ABI the same. 4353 * Why do we do this on EVERY rule? 4354 */ 4355 bcopy(&set_disable, &(((struct ip_fw *)bp)->next_rule), 4356 sizeof(set_disable)); 4357 if (((struct ip_fw *)bp)->timestamp) 4358 ((struct ip_fw *)bp)->timestamp += boot_seconds; 4359 bp += i; 4360 } 4361 } 4362 IPFW_RUNLOCK(chain); 4363 if (ipfw_dyn_v) { 4364 ipfw_dyn_rule *p, *last = NULL; 4365 4366 IPFW_DYN_LOCK(); 4367 for (i = 0 ; i < curr_dyn_buckets; i++) 4368 for (p = ipfw_dyn_v[i] ; p != NULL; p = p->next) { 4369 if (bp + sizeof *p <= ep) { 4370 ipfw_dyn_rule *dst = 4371 (ipfw_dyn_rule *)bp; 4372 bcopy(p, dst, sizeof *p); 4373 bcopy(&(p->rule->rulenum), &(dst->rule), 4374 sizeof(p->rule->rulenum)); 4375 /* 4376 * store a non-null value in "next". 4377 * The userland code will interpret a 4378 * NULL here as a marker 4379 * for the last dynamic rule. 4380 */ 4381 bcopy(&dst, &dst->next, sizeof(dst)); 4382 last = dst; 4383 dst->expire = 4384 TIME_LEQ(dst->expire, time_uptime) ? 4385 0 : dst->expire - time_uptime ; 4386 bp += sizeof(ipfw_dyn_rule); 4387 } 4388 } 4389 IPFW_DYN_UNLOCK(); 4390 if (last != NULL) /* mark last dynamic rule */ 4391 bzero(&last->next, sizeof(last)); 4392 } 4393 return (bp - (char *)buf); 4394} 4395 4396 4397/** 4398 * {set|get}sockopt parser. 4399 */ 4400static int 4401ipfw_ctl(struct sockopt *sopt) 4402{ 4403#define RULE_MAXSIZE (256*sizeof(u_int32_t)) 4404 int error, rule_num; 4405 size_t size; 4406 struct ip_fw *buf, *rule; 4407 u_int32_t rulenum[2]; 4408 4409 error = priv_check(sopt->sopt_td, PRIV_NETINET_IPFW); 4410 if (error) 4411 return (error); 4412 4413 /* 4414 * Disallow modifications in really-really secure mode, but still allow 4415 * the logging counters to be reset. 4416 */ 4417 if (sopt->sopt_name == IP_FW_ADD || 4418 (sopt->sopt_dir == SOPT_SET && sopt->sopt_name != IP_FW_RESETLOG)) { 4419 error = securelevel_ge(sopt->sopt_td->td_ucred, 3); 4420 if (error) 4421 return (error); 4422 } 4423 4424 error = 0; 4425 4426 switch (sopt->sopt_name) { 4427 case IP_FW_GET: 4428 /* 4429 * pass up a copy of the current rules. Static rules 4430 * come first (the last of which has number IPFW_DEFAULT_RULE), 4431 * followed by a possibly empty list of dynamic rule. 4432 * The last dynamic rule has NULL in the "next" field. 4433 * 4434 * Note that the calculated size is used to bound the 4435 * amount of data returned to the user. The rule set may 4436 * change between calculating the size and returning the 4437 * data in which case we'll just return what fits. 4438 */ 4439 size = static_len; /* size of static rules */ 4440 if (ipfw_dyn_v) /* add size of dyn.rules */ 4441 size += (dyn_count * sizeof(ipfw_dyn_rule)); 4442 4443 /* 4444 * XXX todo: if the user passes a short length just to know 4445 * how much room is needed, do not bother filling up the 4446 * buffer, just jump to the sooptcopyout. 4447 */ 4448 buf = malloc(size, M_TEMP, M_WAITOK); 4449 error = sooptcopyout(sopt, buf, 4450 ipfw_getrules(&layer3_chain, buf, size)); 4451 free(buf, M_TEMP); 4452 break; 4453 4454 case IP_FW_FLUSH: 4455 /* 4456 * Normally we cannot release the lock on each iteration. 4457 * We could do it here only because we start from the head all 4458 * the times so there is no risk of missing some entries. 4459 * On the other hand, the risk is that we end up with 4460 * a very inconsistent ruleset, so better keep the lock 4461 * around the whole cycle. 4462 * 4463 * XXX this code can be improved by resetting the head of 4464 * the list to point to the default rule, and then freeing 4465 * the old list without the need for a lock. 4466 */ 4467 4468 IPFW_WLOCK(&layer3_chain); 4469 layer3_chain.reap = NULL; 4470 free_chain(&layer3_chain, 0 /* keep default rule */); 4471 rule = layer3_chain.reap; 4472 layer3_chain.reap = NULL; 4473 IPFW_WUNLOCK(&layer3_chain); 4474 if (rule != NULL) 4475 reap_rules(rule); 4476 break; 4477 4478 case IP_FW_ADD: 4479 rule = malloc(RULE_MAXSIZE, M_TEMP, M_WAITOK); 4480 error = sooptcopyin(sopt, rule, RULE_MAXSIZE, 4481 sizeof(struct ip_fw) ); 4482 if (error == 0) 4483 error = check_ipfw_struct(rule, sopt->sopt_valsize); 4484 if (error == 0) { 4485 error = add_rule(&layer3_chain, rule); 4486 size = RULESIZE(rule); 4487 if (!error && sopt->sopt_dir == SOPT_GET) 4488 error = sooptcopyout(sopt, rule, size); 4489 } 4490 free(rule, M_TEMP); 4491 break; 4492 4493 case IP_FW_DEL: 4494 /* 4495 * IP_FW_DEL is used for deleting single rules or sets, 4496 * and (ab)used to atomically manipulate sets. Argument size 4497 * is used to distinguish between the two: 4498 * sizeof(u_int32_t) 4499 * delete single rule or set of rules, 4500 * or reassign rules (or sets) to a different set. 4501 * 2*sizeof(u_int32_t) 4502 * atomic disable/enable sets. 4503 * first u_int32_t contains sets to be disabled, 4504 * second u_int32_t contains sets to be enabled. 4505 */ 4506 error = sooptcopyin(sopt, rulenum, 4507 2*sizeof(u_int32_t), sizeof(u_int32_t)); 4508 if (error) 4509 break; 4510 size = sopt->sopt_valsize; 4511 if (size == sizeof(u_int32_t)) /* delete or reassign */ 4512 error = del_entry(&layer3_chain, rulenum[0]); 4513 else if (size == 2*sizeof(u_int32_t)) /* set enable/disable */ 4514 set_disable = 4515 (set_disable | rulenum[0]) & ~rulenum[1] & 4516 ~(1<<RESVD_SET); /* set RESVD_SET always enabled */ 4517 else 4518 error = EINVAL; 4519 break; 4520 4521 case IP_FW_ZERO: 4522 case IP_FW_RESETLOG: /* argument is an int, the rule number */ 4523 rule_num = 0; 4524 if (sopt->sopt_val != 0) { 4525 error = sooptcopyin(sopt, &rule_num, 4526 sizeof(int), sizeof(int)); 4527 if (error) 4528 break; 4529 } 4530 error = zero_entry(&layer3_chain, rule_num, 4531 sopt->sopt_name == IP_FW_RESETLOG); 4532 break; 4533 4534 case IP_FW_TABLE_ADD: 4535 { 4536 ipfw_table_entry ent; 4537 4538 error = sooptcopyin(sopt, &ent, 4539 sizeof(ent), sizeof(ent)); 4540 if (error) 4541 break; 4542 error = add_table_entry(&layer3_chain, ent.tbl, 4543 ent.addr, ent.masklen, ent.value); 4544 } 4545 break; 4546 4547 case IP_FW_TABLE_DEL: 4548 { 4549 ipfw_table_entry ent; 4550 4551 error = sooptcopyin(sopt, &ent, 4552 sizeof(ent), sizeof(ent)); 4553 if (error) 4554 break; 4555 error = del_table_entry(&layer3_chain, ent.tbl, 4556 ent.addr, ent.masklen); 4557 } 4558 break; 4559 4560 case IP_FW_TABLE_FLUSH: 4561 { 4562 u_int16_t tbl; 4563 4564 error = sooptcopyin(sopt, &tbl, 4565 sizeof(tbl), sizeof(tbl)); 4566 if (error) 4567 break; 4568 IPFW_WLOCK(&layer3_chain); 4569 error = flush_table(&layer3_chain, tbl); 4570 IPFW_WUNLOCK(&layer3_chain); 4571 } 4572 break; 4573 4574 case IP_FW_TABLE_GETSIZE: 4575 { 4576 u_int32_t tbl, cnt; 4577 4578 if ((error = sooptcopyin(sopt, &tbl, sizeof(tbl), 4579 sizeof(tbl)))) 4580 break; 4581 IPFW_RLOCK(&layer3_chain); 4582 error = count_table(&layer3_chain, tbl, &cnt); 4583 IPFW_RUNLOCK(&layer3_chain); 4584 if (error) 4585 break; 4586 error = sooptcopyout(sopt, &cnt, sizeof(cnt)); 4587 } 4588 break; 4589 4590 case IP_FW_TABLE_LIST: 4591 { 4592 ipfw_table *tbl; 4593 4594 if (sopt->sopt_valsize < sizeof(*tbl)) { 4595 error = EINVAL; 4596 break; 4597 } 4598 size = sopt->sopt_valsize; 4599 tbl = malloc(size, M_TEMP, M_WAITOK); 4600 error = sooptcopyin(sopt, tbl, size, sizeof(*tbl)); 4601 if (error) { 4602 free(tbl, M_TEMP); 4603 break; 4604 } 4605 tbl->size = (size - sizeof(*tbl)) / 4606 sizeof(ipfw_table_entry); 4607 IPFW_RLOCK(&layer3_chain); 4608 error = dump_table(&layer3_chain, tbl); 4609 IPFW_RUNLOCK(&layer3_chain); 4610 if (error) { 4611 free(tbl, M_TEMP); 4612 break; 4613 } 4614 error = sooptcopyout(sopt, tbl, size); 4615 free(tbl, M_TEMP); 4616 } 4617 break; 4618 4619#ifdef IPFIREWALL_NAT 4620 case IP_FW_NAT_CFG: 4621 { 4622 struct cfg_nat *ptr, *ser_n; 4623 char *buf; 4624 4625 buf = malloc(NAT_BUF_LEN, M_IPFW, M_WAITOK | M_ZERO); 4626 error = sooptcopyin(sopt, buf, NAT_BUF_LEN, 4627 sizeof(struct cfg_nat)); 4628 ser_n = (struct cfg_nat *)buf; 4629 4630 /* 4631 * Find/create nat rule. 4632 */ 4633 IPFW_WLOCK(&layer3_chain); 4634 ptr = lookup_nat(ser_n->id); 4635 if (ptr == NULL) { 4636 /* New rule: allocate and init new instance. */ 4637 ptr = malloc(sizeof(struct cfg_nat), 4638 M_IPFW, M_NOWAIT | M_ZERO); 4639 if (ptr == NULL) { 4640 IPFW_WUNLOCK(&layer3_chain); 4641 free(buf, M_IPFW); 4642 return (ENOSPC); 4643 } 4644 ptr->lib = LibAliasInit(NULL); 4645 if (ptr->lib == NULL) { 4646 IPFW_WUNLOCK(&layer3_chain); 4647 free(ptr, M_IPFW); 4648 free(buf, M_IPFW); 4649 return (EINVAL); 4650 } 4651 LIST_INIT(&ptr->redir_chain); 4652 } else { 4653 /* Entry already present: temporarly unhook it. */ 4654 UNHOOK_NAT(ptr); 4655 flush_nat_ptrs(ser_n->id); 4656 } 4657 IPFW_WUNLOCK(&layer3_chain); 4658 4659 /* 4660 * Basic nat configuration. 4661 */ 4662 ptr->id = ser_n->id; 4663 /* 4664 * XXX - what if this rule doesn't nat any ip and just 4665 * redirect? 4666 * do we set aliasaddress to 0.0.0.0? 4667 */ 4668 ptr->ip = ser_n->ip; 4669 ptr->redir_cnt = ser_n->redir_cnt; 4670 ptr->mode = ser_n->mode; 4671 LibAliasSetMode(ptr->lib, ser_n->mode, ser_n->mode); 4672 LibAliasSetAddress(ptr->lib, ptr->ip); 4673 memcpy(ptr->if_name, ser_n->if_name, IF_NAMESIZE); 4674 4675 /* 4676 * Redir and LSNAT configuration. 4677 */ 4678 /* Delete old cfgs. */ 4679 del_redir_spool_cfg(ptr, &ptr->redir_chain); 4680 /* Add new entries. */ 4681 add_redir_spool_cfg(&buf[(sizeof(struct cfg_nat))], ptr); 4682 free(buf, M_IPFW); 4683 IPFW_WLOCK(&layer3_chain); 4684 HOOK_NAT(&layer3_chain.nat, ptr); 4685 IPFW_WUNLOCK(&layer3_chain); 4686 } 4687 break; 4688 4689 case IP_FW_NAT_DEL: 4690 { 4691 struct cfg_nat *ptr; 4692 int i; 4693 4694 error = sooptcopyin(sopt, &i, sizeof i, sizeof i); 4695 IPFW_WLOCK(&layer3_chain); 4696 ptr = lookup_nat(i); 4697 if (ptr == NULL) { 4698 error = EINVAL; 4699 IPFW_WUNLOCK(&layer3_chain); 4700 break; 4701 } 4702 UNHOOK_NAT(ptr); 4703 flush_nat_ptrs(i); 4704 IPFW_WUNLOCK(&layer3_chain); 4705 del_redir_spool_cfg(ptr, &ptr->redir_chain); 4706 LibAliasUninit(ptr->lib); 4707 free(ptr, M_IPFW); 4708 } 4709 break; 4710 4711 case IP_FW_NAT_GET_CONFIG: 4712 { 4713 uint8_t *data; 4714 struct cfg_nat *n; 4715 struct cfg_redir *r; 4716 struct cfg_spool *s; 4717 int nat_cnt, off; 4718 4719 nat_cnt = 0; 4720 off = sizeof(nat_cnt); 4721 4722 data = malloc(NAT_BUF_LEN, M_IPFW, M_WAITOK | M_ZERO); 4723 IPFW_RLOCK(&layer3_chain); 4724 /* Serialize all the data. */ 4725 LIST_FOREACH(n, &layer3_chain.nat, _next) { 4726 nat_cnt++; 4727 if (off + SOF_NAT < NAT_BUF_LEN) { 4728 bcopy(n, &data[off], SOF_NAT); 4729 off += SOF_NAT; 4730 LIST_FOREACH(r, &n->redir_chain, _next) { 4731 if (off + SOF_REDIR < NAT_BUF_LEN) { 4732 bcopy(r, &data[off], 4733 SOF_REDIR); 4734 off += SOF_REDIR; 4735 LIST_FOREACH(s, &r->spool_chain, 4736 _next) { 4737 if (off + SOF_SPOOL < 4738 NAT_BUF_LEN) { 4739 bcopy(s, 4740 &data[off], 4741 SOF_SPOOL); 4742 off += 4743 SOF_SPOOL; 4744 } else 4745 goto nospace; 4746 } 4747 } else 4748 goto nospace; 4749 } 4750 } else 4751 goto nospace; 4752 } 4753 bcopy(&nat_cnt, data, sizeof(nat_cnt)); 4754 IPFW_RUNLOCK(&layer3_chain); 4755 error = sooptcopyout(sopt, data, NAT_BUF_LEN); 4756 free(data, M_IPFW); 4757 break; 4758 nospace: 4759 IPFW_RUNLOCK(&layer3_chain); 4760 printf("serialized data buffer not big enough:" 4761 "please increase NAT_BUF_LEN\n"); 4762 free(data, M_IPFW); 4763 } 4764 break; 4765 4766 case IP_FW_NAT_GET_LOG: 4767 { 4768 uint8_t *data; 4769 struct cfg_nat *ptr; 4770 int i, size, cnt, sof; 4771 4772 data = NULL; 4773 sof = LIBALIAS_BUF_SIZE; 4774 cnt = 0; 4775 4776 IPFW_RLOCK(&layer3_chain); 4777 size = i = 0; 4778 LIST_FOREACH(ptr, &layer3_chain.nat, _next) { 4779 if (ptr->lib->logDesc == NULL) 4780 continue; 4781 cnt++; 4782 size = cnt * (sof + sizeof(int)); 4783 data = realloc(data, size, M_IPFW, M_NOWAIT | M_ZERO); 4784 if (data == NULL) { 4785 IPFW_RUNLOCK(&layer3_chain); 4786 return (ENOSPC); 4787 } 4788 bcopy(&ptr->id, &data[i], sizeof(int)); 4789 i += sizeof(int); 4790 bcopy(ptr->lib->logDesc, &data[i], sof); 4791 i += sof; 4792 } 4793 IPFW_RUNLOCK(&layer3_chain); 4794 error = sooptcopyout(sopt, data, size); 4795 free(data, M_IPFW); 4796 } 4797 break; 4798#endif 4799 4800 default: 4801 printf("ipfw: ipfw_ctl invalid option %d\n", sopt->sopt_name); 4802 error = EINVAL; 4803 } 4804 4805 return (error); 4806#undef RULE_MAXSIZE 4807} 4808 4809/** 4810 * dummynet needs a reference to the default rule, because rules can be 4811 * deleted while packets hold a reference to them. When this happens, 4812 * dummynet changes the reference to the default rule (it could well be a 4813 * NULL pointer, but this way we do not need to check for the special 4814 * case, plus here he have info on the default behaviour). 4815 */ 4816struct ip_fw *ip_fw_default_rule; 4817 4818/* 4819 * This procedure is only used to handle keepalives. It is invoked 4820 * every dyn_keepalive_period 4821 */ 4822static void 4823ipfw_tick(void * __unused unused) 4824{ 4825 struct mbuf *m0, *m, *mnext, **mtailp; 4826 int i; 4827 ipfw_dyn_rule *q; 4828 4829 if (dyn_keepalive == 0 || ipfw_dyn_v == NULL || dyn_count == 0) 4830 goto done; 4831 4832 /* 4833 * We make a chain of packets to go out here -- not deferring 4834 * until after we drop the IPFW dynamic rule lock would result 4835 * in a lock order reversal with the normal packet input -> ipfw 4836 * call stack. 4837 */ 4838 m0 = NULL; 4839 mtailp = &m0; 4840 IPFW_DYN_LOCK(); 4841 for (i = 0 ; i < curr_dyn_buckets ; i++) { 4842 for (q = ipfw_dyn_v[i] ; q ; q = q->next ) { 4843 if (q->dyn_type == O_LIMIT_PARENT) 4844 continue; 4845 if (q->id.proto != IPPROTO_TCP) 4846 continue; 4847 if ( (q->state & BOTH_SYN) != BOTH_SYN) 4848 continue; 4849 if (TIME_LEQ( time_uptime+dyn_keepalive_interval, 4850 q->expire)) 4851 continue; /* too early */ 4852 if (TIME_LEQ(q->expire, time_uptime)) 4853 continue; /* too late, rule expired */ 4854 4855 *mtailp = send_pkt(NULL, &(q->id), q->ack_rev - 1, 4856 q->ack_fwd, TH_SYN); 4857 if (*mtailp != NULL) 4858 mtailp = &(*mtailp)->m_nextpkt; 4859 *mtailp = send_pkt(NULL, &(q->id), q->ack_fwd - 1, 4860 q->ack_rev, 0); 4861 if (*mtailp != NULL) 4862 mtailp = &(*mtailp)->m_nextpkt; 4863 } 4864 } 4865 IPFW_DYN_UNLOCK(); 4866 for (m = mnext = m0; m != NULL; m = mnext) { 4867 mnext = m->m_nextpkt; 4868 m->m_nextpkt = NULL; 4869 ip_output(m, NULL, NULL, 0, NULL, NULL); 4870 } 4871done: 4872 callout_reset(&ipfw_timeout, dyn_keepalive_period*hz, ipfw_tick, NULL); 4873} 4874 4875int 4876ipfw_init(void) 4877{ 4878 struct ip_fw default_rule; 4879 int error; 4880 4881#ifdef INET6 4882 /* Setup IPv6 fw sysctl tree. */ 4883 sysctl_ctx_init(&ip6_fw_sysctl_ctx); 4884 ip6_fw_sysctl_tree = SYSCTL_ADD_NODE(&ip6_fw_sysctl_ctx, 4885 SYSCTL_STATIC_CHILDREN(_net_inet6_ip6), OID_AUTO, "fw", 4886 CTLFLAG_RW | CTLFLAG_SECURE, 0, "Firewall"); 4887 SYSCTL_ADD_PROC(&ip6_fw_sysctl_ctx, SYSCTL_CHILDREN(ip6_fw_sysctl_tree), 4888 OID_AUTO, "enable", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3, 4889 &fw6_enable, 0, ipfw_chg_hook, "I", "Enable ipfw+6"); 4890 SYSCTL_ADD_INT(&ip6_fw_sysctl_ctx, SYSCTL_CHILDREN(ip6_fw_sysctl_tree), 4891 OID_AUTO, "deny_unknown_exthdrs", CTLFLAG_RW | CTLFLAG_SECURE, 4892 &fw_deny_unknown_exthdrs, 0, 4893 "Deny packets with unknown IPv6 Extension Headers"); 4894#endif 4895 4896 layer3_chain.rules = NULL; 4897 IPFW_LOCK_INIT(&layer3_chain); 4898 ipfw_dyn_rule_zone = uma_zcreate("IPFW dynamic rule", 4899 sizeof(ipfw_dyn_rule), NULL, NULL, NULL, NULL, 4900 UMA_ALIGN_PTR, 0); 4901 IPFW_DYN_LOCK_INIT(); 4902 callout_init(&ipfw_timeout, NET_CALLOUT_MPSAFE); 4903 4904 bzero(&default_rule, sizeof default_rule); 4905 4906 default_rule.act_ofs = 0; 4907 default_rule.rulenum = IPFW_DEFAULT_RULE; 4908 default_rule.cmd_len = 1; 4909 default_rule.set = RESVD_SET; 4910 4911 default_rule.cmd[0].len = 1; 4912 default_rule.cmd[0].opcode = 4913#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 4914 1 ? O_ACCEPT : 4915#endif 4916 O_DENY; 4917 4918 error = add_rule(&layer3_chain, &default_rule); 4919 if (error != 0) { 4920 printf("ipfw2: error %u initializing default rule " 4921 "(support disabled)\n", error); 4922 IPFW_DYN_LOCK_DESTROY(); 4923 IPFW_LOCK_DESTROY(&layer3_chain); 4924 uma_zdestroy(ipfw_dyn_rule_zone); 4925 return (error); 4926 } 4927 4928 ip_fw_default_rule = layer3_chain.rules; 4929 printf("ipfw2 " 4930#ifdef INET6 4931 "(+ipv6) " 4932#endif 4933 "initialized, divert %s, " 4934 "rule-based forwarding " 4935#ifdef IPFIREWALL_FORWARD 4936 "enabled, " 4937#else 4938 "disabled, " 4939#endif 4940 "default to %s, logging ", 4941#ifdef IPDIVERT 4942 "enabled", 4943#else 4944 "loadable", 4945#endif 4946 default_rule.cmd[0].opcode == O_ACCEPT ? "accept" : "deny"); 4947 4948#ifdef IPFIREWALL_VERBOSE 4949 fw_verbose = 1; 4950#endif 4951#ifdef IPFIREWALL_VERBOSE_LIMIT 4952 verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 4953#endif 4954 if (fw_verbose == 0) 4955 printf("disabled\n"); 4956 else if (verbose_limit == 0) 4957 printf("unlimited\n"); 4958 else 4959 printf("limited to %d packets/entry by default\n", 4960 verbose_limit); 4961 4962 error = init_tables(&layer3_chain); 4963 if (error) { 4964 IPFW_DYN_LOCK_DESTROY(); 4965 IPFW_LOCK_DESTROY(&layer3_chain); 4966 uma_zdestroy(ipfw_dyn_rule_zone); 4967 return (error); 4968 } 4969 ip_fw_ctl_ptr = ipfw_ctl; 4970 ip_fw_chk_ptr = ipfw_chk; 4971 callout_reset(&ipfw_timeout, hz, ipfw_tick, NULL); 4972#ifdef IPFIREWALL_NAT 4973 LIST_INIT(&layer3_chain.nat); 4974 ifaddr_event_tag = EVENTHANDLER_REGISTER(ifaddr_event, ifaddr_change, 4975 NULL, EVENTHANDLER_PRI_ANY); 4976#endif 4977 return (0); 4978} 4979 4980void 4981ipfw_destroy(void) 4982{ 4983 struct ip_fw *reap; 4984#ifdef IPFIREWALL_NAT 4985 struct cfg_nat *ptr, *ptr_temp; 4986#endif 4987 4988 ip_fw_chk_ptr = NULL; 4989 ip_fw_ctl_ptr = NULL; 4990 callout_drain(&ipfw_timeout); 4991 IPFW_WLOCK(&layer3_chain); 4992 flush_tables(&layer3_chain); 4993#ifdef IPFIREWALL_NAT 4994 LIST_FOREACH_SAFE(ptr, &layer3_chain.nat, _next, ptr_temp) { 4995 LIST_REMOVE(ptr, _next); 4996 del_redir_spool_cfg(ptr, &ptr->redir_chain); 4997 LibAliasUninit(ptr->lib); 4998 free(ptr, M_IPFW); 4999 } 5000 EVENTHANDLER_DEREGISTER(ifaddr_event, ifaddr_event_tag); 5001#endif 5002 layer3_chain.reap = NULL; 5003 free_chain(&layer3_chain, 1 /* kill default rule */); 5004 reap = layer3_chain.reap, layer3_chain.reap = NULL; 5005 IPFW_WUNLOCK(&layer3_chain); 5006 if (reap != NULL) 5007 reap_rules(reap); 5008 IPFW_DYN_LOCK_DESTROY(); 5009 uma_zdestroy(ipfw_dyn_rule_zone); 5010 IPFW_LOCK_DESTROY(&layer3_chain); 5011 5012#ifdef INET6 5013 /* Free IPv6 fw sysctl tree. */ 5014 sysctl_ctx_free(&ip6_fw_sysctl_ctx); 5015#endif 5016 5017 printf("IP firewall unloaded\n"); 5018} 5019