ip_fw2.c revision 171167
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 171167 2007-07-03 12:13:45Z gnn $ 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#include <netinet/ip6.h> 97#include <netinet/icmp6.h> 98#ifdef INET6 99#include <netinet6/scope6_var.h> 100#endif 101 102#include <netinet/if_ether.h> /* XXX for ETHERTYPE_IP */ 103 104#include <machine/in_cksum.h> /* XXX for in_cksum */ 105 106#include <security/mac/mac_framework.h> 107 108/* 109 * set_disable contains one bit per set value (0..31). 110 * If the bit is set, all rules with the corresponding set 111 * are disabled. Set RESVD_SET(31) is reserved for the default rule 112 * and rules that are not deleted by the flush command, 113 * and CANNOT be disabled. 114 * Rules in set RESVD_SET can only be deleted explicitly. 115 */ 116static u_int32_t set_disable; 117 118static int fw_verbose; 119static int verbose_limit; 120 121static struct callout ipfw_timeout; 122static uma_zone_t ipfw_dyn_rule_zone; 123#define IPFW_DEFAULT_RULE 65535 124 125/* 126 * Data structure to cache our ucred related 127 * information. This structure only gets used if 128 * the user specified UID/GID based constraints in 129 * a firewall rule. 130 */ 131struct ip_fw_ugid { 132 gid_t fw_groups[NGROUPS]; 133 int fw_ngroups; 134 uid_t fw_uid; 135 int fw_prid; 136}; 137 138#define IPFW_TABLES_MAX 128 139struct ip_fw_chain { 140 struct ip_fw *rules; /* list of rules */ 141 struct ip_fw *reap; /* list of rules to reap */ 142 LIST_HEAD(, cfg_nat) nat; /* list of nat entries */ 143 struct radix_node_head *tables[IPFW_TABLES_MAX]; 144 struct rwlock rwmtx; 145}; 146#define IPFW_LOCK_INIT(_chain) \ 147 rw_init(&(_chain)->rwmtx, "IPFW static rules") 148#define IPFW_LOCK_DESTROY(_chain) rw_destroy(&(_chain)->rwmtx) 149#define IPFW_WLOCK_ASSERT(_chain) do { \ 150 rw_assert(&(_chain)->rwmtx, RA_WLOCKED); \ 151 NET_ASSERT_GIANT(); \ 152} while (0) 153 154#define IPFW_RLOCK(p) rw_rlock(&(p)->rwmtx) 155#define IPFW_RUNLOCK(p) rw_runlock(&(p)->rwmtx) 156#define IPFW_WLOCK(p) rw_wlock(&(p)->rwmtx) 157#define IPFW_WUNLOCK(p) rw_wunlock(&(p)->rwmtx) 158 159/* 160 * list of rules for layer 3 161 */ 162static struct ip_fw_chain layer3_chain; 163 164MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's"); 165MALLOC_DEFINE(M_IPFW_TBL, "ipfw_tbl", "IpFw tables"); 166 167struct table_entry { 168 struct radix_node rn[2]; 169 struct sockaddr_in addr, mask; 170 u_int32_t value; 171}; 172 173static int fw_debug = 1; 174static int autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 175 176extern int ipfw_chg_hook(SYSCTL_HANDLER_ARGS); 177 178#ifdef SYSCTL_NODE 179SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 180SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, enable, 181 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3, &fw_enable, 0, 182 ipfw_chg_hook, "I", "Enable ipfw"); 183SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, CTLFLAG_RW, 184 &autoinc_step, 0, "Rule number autincrement step"); 185SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 186 CTLFLAG_RW | CTLFLAG_SECURE3, 187 &fw_one_pass, 0, 188 "Only do a single pass through ipfw when using dummynet(4)"); 189SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW, 190 &fw_debug, 0, "Enable printing of debug ip_fw statements"); 191SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, 192 CTLFLAG_RW | CTLFLAG_SECURE3, 193 &fw_verbose, 0, "Log matches to ipfw rules"); 194SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, 195 &verbose_limit, 0, "Set upper limit of matches of ipfw rules logged"); 196 197/* 198 * Description of dynamic rules. 199 * 200 * Dynamic rules are stored in lists accessed through a hash table 201 * (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can 202 * be modified through the sysctl variable dyn_buckets which is 203 * updated when the table becomes empty. 204 * 205 * XXX currently there is only one list, ipfw_dyn. 206 * 207 * When a packet is received, its address fields are first masked 208 * with the mask defined for the rule, then hashed, then matched 209 * against the entries in the corresponding list. 210 * Dynamic rules can be used for different purposes: 211 * + stateful rules; 212 * + enforcing limits on the number of sessions; 213 * + in-kernel NAT (not implemented yet) 214 * 215 * The lifetime of dynamic rules is regulated by dyn_*_lifetime, 216 * measured in seconds and depending on the flags. 217 * 218 * The total number of dynamic rules is stored in dyn_count. 219 * The max number of dynamic rules is dyn_max. When we reach 220 * the maximum number of rules we do not create anymore. This is 221 * done to avoid consuming too much memory, but also too much 222 * time when searching on each packet (ideally, we should try instead 223 * to put a limit on the length of the list on each bucket...). 224 * 225 * Each dynamic rule holds a pointer to the parent ipfw rule so 226 * we know what action to perform. Dynamic rules are removed when 227 * the parent rule is deleted. XXX we should make them survive. 228 * 229 * There are some limitations with dynamic rules -- we do not 230 * obey the 'randomized match', and we do not do multiple 231 * passes through the firewall. XXX check the latter!!! 232 */ 233static ipfw_dyn_rule **ipfw_dyn_v = NULL; 234static u_int32_t dyn_buckets = 256; /* must be power of 2 */ 235static u_int32_t curr_dyn_buckets = 256; /* must be power of 2 */ 236 237static struct mtx ipfw_dyn_mtx; /* mutex guarding dynamic rules */ 238#define IPFW_DYN_LOCK_INIT() \ 239 mtx_init(&ipfw_dyn_mtx, "IPFW dynamic rules", NULL, MTX_DEF) 240#define IPFW_DYN_LOCK_DESTROY() mtx_destroy(&ipfw_dyn_mtx) 241#define IPFW_DYN_LOCK() mtx_lock(&ipfw_dyn_mtx) 242#define IPFW_DYN_UNLOCK() mtx_unlock(&ipfw_dyn_mtx) 243#define IPFW_DYN_LOCK_ASSERT() mtx_assert(&ipfw_dyn_mtx, MA_OWNED) 244 245/* 246 * Timeouts for various events in handing dynamic rules. 247 */ 248static u_int32_t dyn_ack_lifetime = 300; 249static u_int32_t dyn_syn_lifetime = 20; 250static u_int32_t dyn_fin_lifetime = 1; 251static u_int32_t dyn_rst_lifetime = 1; 252static u_int32_t dyn_udp_lifetime = 10; 253static u_int32_t dyn_short_lifetime = 5; 254 255/* 256 * Keepalives are sent if dyn_keepalive is set. They are sent every 257 * dyn_keepalive_period seconds, in the last dyn_keepalive_interval 258 * seconds of lifetime of a rule. 259 * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower 260 * than dyn_keepalive_period. 261 */ 262 263static u_int32_t dyn_keepalive_interval = 20; 264static u_int32_t dyn_keepalive_period = 5; 265static u_int32_t dyn_keepalive = 1; /* do send keepalives */ 266 267static u_int32_t static_count; /* # of static rules */ 268static u_int32_t static_len; /* size in bytes of static rules */ 269static u_int32_t dyn_count; /* # of dynamic rules */ 270static u_int32_t dyn_max = 4096; /* max # of dynamic rules */ 271 272SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLFLAG_RW, 273 &dyn_buckets, 0, "Number of dyn. buckets"); 274SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_RD, 275 &curr_dyn_buckets, 0, "Current Number of dyn. buckets"); 276SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_RD, 277 &dyn_count, 0, "Number of dyn. rules"); 278SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_RW, 279 &dyn_max, 0, "Max number of dyn. rules"); 280SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, CTLFLAG_RD, 281 &static_count, 0, "Number of static rules"); 282SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_RW, 283 &dyn_ack_lifetime, 0, "Lifetime of dyn. rules for acks"); 284SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_RW, 285 &dyn_syn_lifetime, 0, "Lifetime of dyn. rules for syn"); 286SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, CTLFLAG_RW, 287 &dyn_fin_lifetime, 0, "Lifetime of dyn. rules for fin"); 288SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, CTLFLAG_RW, 289 &dyn_rst_lifetime, 0, "Lifetime of dyn. rules for rst"); 290SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime, CTLFLAG_RW, 291 &dyn_udp_lifetime, 0, "Lifetime of dyn. rules for UDP"); 292SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_RW, 293 &dyn_short_lifetime, 0, "Lifetime of dyn. rules for other situations"); 294SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_keepalive, CTLFLAG_RW, 295 &dyn_keepalive, 0, "Enable keepalives for dyn. rules"); 296 297#ifdef INET6 298/* 299 * IPv6 specific variables 300 */ 301SYSCTL_DECL(_net_inet6_ip6); 302 303static struct sysctl_ctx_list ip6_fw_sysctl_ctx; 304static struct sysctl_oid *ip6_fw_sysctl_tree; 305#endif /* INET6 */ 306#endif /* SYSCTL_NODE */ 307 308#ifdef IPFIREWALL_NAT 309MODULE_DEPEND(ipfw, libalias, 1, 1, 1); 310#endif 311static int fw_deny_unknown_exthdrs = 1; 312 313 314/* 315 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 316 * Other macros just cast void * into the appropriate type 317 */ 318#define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 319#define TCP(p) ((struct tcphdr *)(p)) 320#define SCTP(p) ((struct sctphdr *)(p)) 321#define UDP(p) ((struct udphdr *)(p)) 322#define ICMP(p) ((struct icmphdr *)(p)) 323#define ICMP6(p) ((struct icmp6_hdr *)(p)) 324 325static __inline int 326icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 327{ 328 int type = icmp->icmp_type; 329 330 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 331} 332 333#define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 334 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 335 336static int 337is_icmp_query(struct icmphdr *icmp) 338{ 339 int type = icmp->icmp_type; 340 341 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 342} 343#undef TT 344 345/* 346 * The following checks use two arrays of 8 or 16 bits to store the 347 * bits that we want set or clear, respectively. They are in the 348 * low and high half of cmd->arg1 or cmd->d[0]. 349 * 350 * We scan options and store the bits we find set. We succeed if 351 * 352 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 353 * 354 * The code is sometimes optimized not to store additional variables. 355 */ 356 357static int 358flags_match(ipfw_insn *cmd, u_int8_t bits) 359{ 360 u_char want_clear; 361 bits = ~bits; 362 363 if ( ((cmd->arg1 & 0xff) & bits) != 0) 364 return 0; /* some bits we want set were clear */ 365 want_clear = (cmd->arg1 >> 8) & 0xff; 366 if ( (want_clear & bits) != want_clear) 367 return 0; /* some bits we want clear were set */ 368 return 1; 369} 370 371static int 372ipopts_match(struct ip *ip, ipfw_insn *cmd) 373{ 374 int optlen, bits = 0; 375 u_char *cp = (u_char *)(ip + 1); 376 int x = (ip->ip_hl << 2) - sizeof (struct ip); 377 378 for (; x > 0; x -= optlen, cp += optlen) { 379 int opt = cp[IPOPT_OPTVAL]; 380 381 if (opt == IPOPT_EOL) 382 break; 383 if (opt == IPOPT_NOP) 384 optlen = 1; 385 else { 386 optlen = cp[IPOPT_OLEN]; 387 if (optlen <= 0 || optlen > x) 388 return 0; /* invalid or truncated */ 389 } 390 switch (opt) { 391 392 default: 393 break; 394 395 case IPOPT_LSRR: 396 bits |= IP_FW_IPOPT_LSRR; 397 break; 398 399 case IPOPT_SSRR: 400 bits |= IP_FW_IPOPT_SSRR; 401 break; 402 403 case IPOPT_RR: 404 bits |= IP_FW_IPOPT_RR; 405 break; 406 407 case IPOPT_TS: 408 bits |= IP_FW_IPOPT_TS; 409 break; 410 } 411 } 412 return (flags_match(cmd, bits)); 413} 414 415static int 416tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 417{ 418 int optlen, bits = 0; 419 u_char *cp = (u_char *)(tcp + 1); 420 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 421 422 for (; x > 0; x -= optlen, cp += optlen) { 423 int opt = cp[0]; 424 if (opt == TCPOPT_EOL) 425 break; 426 if (opt == TCPOPT_NOP) 427 optlen = 1; 428 else { 429 optlen = cp[1]; 430 if (optlen <= 0) 431 break; 432 } 433 434 switch (opt) { 435 436 default: 437 break; 438 439 case TCPOPT_MAXSEG: 440 bits |= IP_FW_TCPOPT_MSS; 441 break; 442 443 case TCPOPT_WINDOW: 444 bits |= IP_FW_TCPOPT_WINDOW; 445 break; 446 447 case TCPOPT_SACK_PERMITTED: 448 case TCPOPT_SACK: 449 bits |= IP_FW_TCPOPT_SACK; 450 break; 451 452 case TCPOPT_TIMESTAMP: 453 bits |= IP_FW_TCPOPT_TS; 454 break; 455 456 } 457 } 458 return (flags_match(cmd, bits)); 459} 460 461static int 462iface_match(struct ifnet *ifp, ipfw_insn_if *cmd) 463{ 464 if (ifp == NULL) /* no iface with this packet, match fails */ 465 return 0; 466 /* Check by name or by IP address */ 467 if (cmd->name[0] != '\0') { /* match by name */ 468 /* Check name */ 469 if (cmd->p.glob) { 470 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 471 return(1); 472 } else { 473 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 474 return(1); 475 } 476 } else { 477 struct ifaddr *ia; 478 479 /* XXX lock? */ 480 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 481 if (ia->ifa_addr->sa_family != AF_INET) 482 continue; 483 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 484 (ia->ifa_addr))->sin_addr.s_addr) 485 return(1); /* match */ 486 } 487 } 488 return(0); /* no match, fail ... */ 489} 490 491/* 492 * The verify_path function checks if a route to the src exists and 493 * if it is reachable via ifp (when provided). 494 * 495 * The 'verrevpath' option checks that the interface that an IP packet 496 * arrives on is the same interface that traffic destined for the 497 * packet's source address would be routed out of. The 'versrcreach' 498 * option just checks that the source address is reachable via any route 499 * (except default) in the routing table. These two are a measure to block 500 * forged packets. This is also commonly known as "anti-spoofing" or Unicast 501 * Reverse Path Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 502 * is purposely reminiscent of the Cisco IOS command, 503 * 504 * ip verify unicast reverse-path 505 * ip verify unicast source reachable-via any 506 * 507 * which implements the same functionality. But note that syntax is 508 * misleading. The check may be performed on all IP packets whether unicast, 509 * multicast, or broadcast. 510 */ 511static int 512verify_path(struct in_addr src, struct ifnet *ifp) 513{ 514 struct route ro; 515 struct sockaddr_in *dst; 516 517 bzero(&ro, sizeof(ro)); 518 519 dst = (struct sockaddr_in *)&(ro.ro_dst); 520 dst->sin_family = AF_INET; 521 dst->sin_len = sizeof(*dst); 522 dst->sin_addr = src; 523 rtalloc_ign(&ro, RTF_CLONING); 524 525 if (ro.ro_rt == NULL) 526 return 0; 527 528 /* 529 * If ifp is provided, check for equality with rtentry. 530 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 531 * in order to pass packets injected back by if_simloop(): 532 * if useloopback == 1 routing entry (via lo0) for our own address 533 * may exist, so we need to handle routing assymetry. 534 */ 535 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 536 RTFREE(ro.ro_rt); 537 return 0; 538 } 539 540 /* if no ifp provided, check if rtentry is not default route */ 541 if (ifp == NULL && 542 satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) { 543 RTFREE(ro.ro_rt); 544 return 0; 545 } 546 547 /* or if this is a blackhole/reject route */ 548 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 549 RTFREE(ro.ro_rt); 550 return 0; 551 } 552 553 /* found valid route */ 554 RTFREE(ro.ro_rt); 555 return 1; 556} 557 558#ifdef INET6 559/* 560 * ipv6 specific rules here... 561 */ 562static __inline int 563icmp6type_match (int type, ipfw_insn_u32 *cmd) 564{ 565 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 566} 567 568static int 569flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 570{ 571 int i; 572 for (i=0; i <= cmd->o.arg1; ++i ) 573 if (curr_flow == cmd->d[i] ) 574 return 1; 575 return 0; 576} 577 578/* support for IP6_*_ME opcodes */ 579static int 580search_ip6_addr_net (struct in6_addr * ip6_addr) 581{ 582 struct ifnet *mdc; 583 struct ifaddr *mdc2; 584 struct in6_ifaddr *fdm; 585 struct in6_addr copia; 586 587 TAILQ_FOREACH(mdc, &ifnet, if_link) 588 TAILQ_FOREACH(mdc2, &mdc->if_addrlist, ifa_list) { 589 if (mdc2->ifa_addr->sa_family == AF_INET6) { 590 fdm = (struct in6_ifaddr *)mdc2; 591 copia = fdm->ia_addr.sin6_addr; 592 /* need for leaving scope_id in the sock_addr */ 593 in6_clearscope(&copia); 594 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) 595 return 1; 596 } 597 } 598 return 0; 599} 600 601static int 602verify_path6(struct in6_addr *src, struct ifnet *ifp) 603{ 604 struct route_in6 ro; 605 struct sockaddr_in6 *dst; 606 607 bzero(&ro, sizeof(ro)); 608 609 dst = (struct sockaddr_in6 * )&(ro.ro_dst); 610 dst->sin6_family = AF_INET6; 611 dst->sin6_len = sizeof(*dst); 612 dst->sin6_addr = *src; 613 rtalloc_ign((struct route *)&ro, RTF_CLONING); 614 615 if (ro.ro_rt == NULL) 616 return 0; 617 618 /* 619 * if ifp is provided, check for equality with rtentry 620 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 621 * to support the case of sending packets to an address of our own. 622 * (where the former interface is the first argument of if_simloop() 623 * (=ifp), the latter is lo0) 624 */ 625 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 626 RTFREE(ro.ro_rt); 627 return 0; 628 } 629 630 /* if no ifp provided, check if rtentry is not default route */ 631 if (ifp == NULL && 632 IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) { 633 RTFREE(ro.ro_rt); 634 return 0; 635 } 636 637 /* or if this is a blackhole/reject route */ 638 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 639 RTFREE(ro.ro_rt); 640 return 0; 641 } 642 643 /* found valid route */ 644 RTFREE(ro.ro_rt); 645 return 1; 646 647} 648static __inline int 649hash_packet6(struct ipfw_flow_id *id) 650{ 651 u_int32_t i; 652 i = (id->dst_ip6.__u6_addr.__u6_addr32[2]) ^ 653 (id->dst_ip6.__u6_addr.__u6_addr32[3]) ^ 654 (id->src_ip6.__u6_addr.__u6_addr32[2]) ^ 655 (id->src_ip6.__u6_addr.__u6_addr32[3]) ^ 656 (id->dst_port) ^ (id->src_port); 657 return i; 658} 659 660static int 661is_icmp6_query(int icmp6_type) 662{ 663 if ((icmp6_type <= ICMP6_MAXTYPE) && 664 (icmp6_type == ICMP6_ECHO_REQUEST || 665 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 666 icmp6_type == ICMP6_WRUREQUEST || 667 icmp6_type == ICMP6_FQDN_QUERY || 668 icmp6_type == ICMP6_NI_QUERY)) 669 return (1); 670 671 return (0); 672} 673 674static void 675send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 676{ 677 struct mbuf *m; 678 679 m = args->m; 680 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 681 struct tcphdr *tcp; 682 tcp_seq ack, seq; 683 int flags; 684 struct { 685 struct ip6_hdr ip6; 686 struct tcphdr th; 687 } ti; 688 tcp = (struct tcphdr *)((char *)ip6 + hlen); 689 690 if ((tcp->th_flags & TH_RST) != 0) { 691 m_freem(m); 692 args->m = NULL; 693 return; 694 } 695 696 ti.ip6 = *ip6; 697 ti.th = *tcp; 698 ti.th.th_seq = ntohl(ti.th.th_seq); 699 ti.th.th_ack = ntohl(ti.th.th_ack); 700 ti.ip6.ip6_nxt = IPPROTO_TCP; 701 702 if (ti.th.th_flags & TH_ACK) { 703 ack = 0; 704 seq = ti.th.th_ack; 705 flags = TH_RST; 706 } else { 707 ack = ti.th.th_seq; 708 if ((m->m_flags & M_PKTHDR) != 0) { 709 /* 710 * total new data to ACK is: 711 * total packet length, 712 * minus the header length, 713 * minus the tcp header length. 714 */ 715 ack += m->m_pkthdr.len - hlen 716 - (ti.th.th_off << 2); 717 } else if (ip6->ip6_plen) { 718 ack += ntohs(ip6->ip6_plen) + sizeof(*ip6) - 719 hlen - (ti.th.th_off << 2); 720 } else { 721 m_freem(m); 722 return; 723 } 724 if (tcp->th_flags & TH_SYN) 725 ack++; 726 seq = 0; 727 flags = TH_RST|TH_ACK; 728 } 729 bcopy(&ti, ip6, sizeof(ti)); 730 /* 731 * m is only used to recycle the mbuf 732 * The data in it is never read so we don't need 733 * to correct the offsets or anything 734 */ 735 tcp_respond(NULL, ip6, tcp, m, ack, seq, flags); 736 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */ 737#if 0 738 /* 739 * Unlike above, the mbufs need to line up with the ip6 hdr, 740 * as the contents are read. We need to m_adj() the 741 * needed amount. 742 * The mbuf will however be thrown away so we can adjust it. 743 * Remember we did an m_pullup on it already so we 744 * can make some assumptions about contiguousness. 745 */ 746 if (args->L3offset) 747 m_adj(m, args->L3offset); 748#endif 749 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 750 } else 751 m_freem(m); 752 753 args->m = NULL; 754} 755 756#endif /* INET6 */ 757 758static u_int64_t norule_counter; /* counter for ipfw_log(NULL...) */ 759 760#define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0 761#define SNP(buf) buf, sizeof(buf) 762 763/* 764 * We enter here when we have a rule with O_LOG. 765 * XXX this function alone takes about 2Kbytes of code! 766 */ 767static void 768ipfw_log(struct ip_fw *f, u_int hlen, struct ip_fw_args *args, 769 struct mbuf *m, struct ifnet *oif, u_short offset, uint32_t tablearg, 770 struct ip *ip) 771{ 772 struct ether_header *eh = args->eh; 773 char *action; 774 int limit_reached = 0; 775 char action2[40], proto[128], fragment[32]; 776 777 fragment[0] = '\0'; 778 proto[0] = '\0'; 779 780 if (f == NULL) { /* bogus pkt */ 781 if (verbose_limit != 0 && norule_counter >= verbose_limit) 782 return; 783 norule_counter++; 784 if (norule_counter == verbose_limit) 785 limit_reached = verbose_limit; 786 action = "Refuse"; 787 } else { /* O_LOG is the first action, find the real one */ 788 ipfw_insn *cmd = ACTION_PTR(f); 789 ipfw_insn_log *l = (ipfw_insn_log *)cmd; 790 791 if (l->max_log != 0 && l->log_left == 0) 792 return; 793 l->log_left--; 794 if (l->log_left == 0) 795 limit_reached = l->max_log; 796 cmd += F_LEN(cmd); /* point to first action */ 797 if (cmd->opcode == O_ALTQ) { 798 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 799 800 snprintf(SNPARGS(action2, 0), "Altq %d", 801 altq->qid); 802 cmd += F_LEN(cmd); 803 } 804 if (cmd->opcode == O_PROB) 805 cmd += F_LEN(cmd); 806 807 if (cmd->opcode == O_TAG) 808 cmd += F_LEN(cmd); 809 810 action = action2; 811 switch (cmd->opcode) { 812 case O_DENY: 813 action = "Deny"; 814 break; 815 816 case O_REJECT: 817 if (cmd->arg1==ICMP_REJECT_RST) 818 action = "Reset"; 819 else if (cmd->arg1==ICMP_UNREACH_HOST) 820 action = "Reject"; 821 else 822 snprintf(SNPARGS(action2, 0), "Unreach %d", 823 cmd->arg1); 824 break; 825 826 case O_UNREACH6: 827 if (cmd->arg1==ICMP6_UNREACH_RST) 828 action = "Reset"; 829 else 830 snprintf(SNPARGS(action2, 0), "Unreach %d", 831 cmd->arg1); 832 break; 833 834 case O_ACCEPT: 835 action = "Accept"; 836 break; 837 case O_COUNT: 838 action = "Count"; 839 break; 840 case O_DIVERT: 841 snprintf(SNPARGS(action2, 0), "Divert %d", 842 cmd->arg1); 843 break; 844 case O_TEE: 845 snprintf(SNPARGS(action2, 0), "Tee %d", 846 cmd->arg1); 847 break; 848 case O_SKIPTO: 849 snprintf(SNPARGS(action2, 0), "SkipTo %d", 850 cmd->arg1); 851 break; 852 case O_PIPE: 853 snprintf(SNPARGS(action2, 0), "Pipe %d", 854 cmd->arg1); 855 break; 856 case O_QUEUE: 857 snprintf(SNPARGS(action2, 0), "Queue %d", 858 cmd->arg1); 859 break; 860 case O_FORWARD_IP: { 861 ipfw_insn_sa *sa = (ipfw_insn_sa *)cmd; 862 int len; 863 struct in_addr dummyaddr; 864 if (sa->sa.sin_addr.s_addr == INADDR_ANY) 865 dummyaddr.s_addr = htonl(tablearg); 866 else 867 dummyaddr.s_addr = sa->sa.sin_addr.s_addr; 868 869 len = snprintf(SNPARGS(action2, 0), "Forward to %s", 870 inet_ntoa(dummyaddr)); 871 872 if (sa->sa.sin_port) 873 snprintf(SNPARGS(action2, len), ":%d", 874 sa->sa.sin_port); 875 } 876 break; 877 case O_NETGRAPH: 878 snprintf(SNPARGS(action2, 0), "Netgraph %d", 879 cmd->arg1); 880 break; 881 case O_NGTEE: 882 snprintf(SNPARGS(action2, 0), "Ngtee %d", 883 cmd->arg1); 884 break; 885 case O_NAT: 886 action = "Nat"; 887 break; 888 default: 889 action = "UNKNOWN"; 890 break; 891 } 892 } 893 894 if (hlen == 0) { /* non-ip */ 895 snprintf(SNPARGS(proto, 0), "MAC"); 896 897 } else { 898 int len; 899 char src[48], dst[48]; 900 struct icmphdr *icmp; 901 struct tcphdr *tcp; 902 struct udphdr *udp; 903#ifdef INET6 904 struct ip6_hdr *ip6 = NULL; 905 struct icmp6_hdr *icmp6; 906#endif 907 src[0] = '\0'; 908 dst[0] = '\0'; 909#ifdef INET6 910 if (IS_IP6_FLOW_ID(&(args->f_id))) { 911 char ip6buf[INET6_ADDRSTRLEN]; 912 snprintf(src, sizeof(src), "[%s]", 913 ip6_sprintf(ip6buf, &args->f_id.src_ip6)); 914 snprintf(dst, sizeof(dst), "[%s]", 915 ip6_sprintf(ip6buf, &args->f_id.dst_ip6)); 916 917 ip6 = (struct ip6_hdr *)ip; 918 tcp = (struct tcphdr *)(((char *)ip) + hlen); 919 udp = (struct udphdr *)(((char *)ip) + hlen); 920 } else 921#endif 922 { 923 tcp = L3HDR(struct tcphdr, ip); 924 udp = L3HDR(struct udphdr, ip); 925 926 inet_ntoa_r(ip->ip_src, src); 927 inet_ntoa_r(ip->ip_dst, dst); 928 } 929 930 switch (args->f_id.proto) { 931 case IPPROTO_TCP: 932 len = snprintf(SNPARGS(proto, 0), "TCP %s", src); 933 if (offset == 0) 934 snprintf(SNPARGS(proto, len), ":%d %s:%d", 935 ntohs(tcp->th_sport), 936 dst, 937 ntohs(tcp->th_dport)); 938 else 939 snprintf(SNPARGS(proto, len), " %s", dst); 940 break; 941 942 case IPPROTO_UDP: 943 len = snprintf(SNPARGS(proto, 0), "UDP %s", src); 944 if (offset == 0) 945 snprintf(SNPARGS(proto, len), ":%d %s:%d", 946 ntohs(udp->uh_sport), 947 dst, 948 ntohs(udp->uh_dport)); 949 else 950 snprintf(SNPARGS(proto, len), " %s", dst); 951 break; 952 953 case IPPROTO_ICMP: 954 icmp = L3HDR(struct icmphdr, ip); 955 if (offset == 0) 956 len = snprintf(SNPARGS(proto, 0), 957 "ICMP:%u.%u ", 958 icmp->icmp_type, icmp->icmp_code); 959 else 960 len = snprintf(SNPARGS(proto, 0), "ICMP "); 961 len += snprintf(SNPARGS(proto, len), "%s", src); 962 snprintf(SNPARGS(proto, len), " %s", dst); 963 break; 964#ifdef INET6 965 case IPPROTO_ICMPV6: 966 icmp6 = (struct icmp6_hdr *)(((char *)ip) + hlen); 967 if (offset == 0) 968 len = snprintf(SNPARGS(proto, 0), 969 "ICMPv6:%u.%u ", 970 icmp6->icmp6_type, icmp6->icmp6_code); 971 else 972 len = snprintf(SNPARGS(proto, 0), "ICMPv6 "); 973 len += snprintf(SNPARGS(proto, len), "%s", src); 974 snprintf(SNPARGS(proto, len), " %s", dst); 975 break; 976#endif 977 default: 978 len = snprintf(SNPARGS(proto, 0), "P:%d %s", 979 args->f_id.proto, src); 980 snprintf(SNPARGS(proto, len), " %s", dst); 981 break; 982 } 983 984#ifdef INET6 985 if (IS_IP6_FLOW_ID(&(args->f_id))) { 986 if (offset & (IP6F_OFF_MASK | IP6F_MORE_FRAG)) 987 snprintf(SNPARGS(fragment, 0), 988 " (frag %08x:%d@%d%s)", 989 args->f_id.frag_id6, 990 ntohs(ip6->ip6_plen) - hlen, 991 ntohs(offset & IP6F_OFF_MASK) << 3, 992 (offset & IP6F_MORE_FRAG) ? "+" : ""); 993 } else 994#endif 995 { 996 int ip_off, ip_len; 997 if (eh != NULL) { /* layer 2 packets are as on the wire */ 998 ip_off = ntohs(ip->ip_off); 999 ip_len = ntohs(ip->ip_len); 1000 } else { 1001 ip_off = ip->ip_off; 1002 ip_len = ip->ip_len; 1003 } 1004 if (ip_off & (IP_MF | IP_OFFMASK)) 1005 snprintf(SNPARGS(fragment, 0), 1006 " (frag %d:%d@%d%s)", 1007 ntohs(ip->ip_id), ip_len - (ip->ip_hl << 2), 1008 offset << 3, 1009 (ip_off & IP_MF) ? "+" : ""); 1010 } 1011 } 1012 if (oif || m->m_pkthdr.rcvif) 1013 log(LOG_SECURITY | LOG_INFO, 1014 "ipfw: %d %s %s %s via %s%s\n", 1015 f ? f->rulenum : -1, 1016 action, proto, oif ? "out" : "in", 1017 oif ? oif->if_xname : m->m_pkthdr.rcvif->if_xname, 1018 fragment); 1019 else 1020 log(LOG_SECURITY | LOG_INFO, 1021 "ipfw: %d %s %s [no if info]%s\n", 1022 f ? f->rulenum : -1, 1023 action, proto, fragment); 1024 if (limit_reached) 1025 log(LOG_SECURITY | LOG_NOTICE, 1026 "ipfw: limit %d reached on entry %d\n", 1027 limit_reached, f ? f->rulenum : -1); 1028} 1029 1030/* 1031 * IMPORTANT: the hash function for dynamic rules must be commutative 1032 * in source and destination (ip,port), because rules are bidirectional 1033 * and we want to find both in the same bucket. 1034 */ 1035static __inline int 1036hash_packet(struct ipfw_flow_id *id) 1037{ 1038 u_int32_t i; 1039 1040#ifdef INET6 1041 if (IS_IP6_FLOW_ID(id)) 1042 i = hash_packet6(id); 1043 else 1044#endif /* INET6 */ 1045 i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port); 1046 i &= (curr_dyn_buckets - 1); 1047 return i; 1048} 1049 1050/** 1051 * unlink a dynamic rule from a chain. prev is a pointer to 1052 * the previous one, q is a pointer to the rule to delete, 1053 * head is a pointer to the head of the queue. 1054 * Modifies q and potentially also head. 1055 */ 1056#define UNLINK_DYN_RULE(prev, head, q) { \ 1057 ipfw_dyn_rule *old_q = q; \ 1058 \ 1059 /* remove a refcount to the parent */ \ 1060 if (q->dyn_type == O_LIMIT) \ 1061 q->parent->count--; \ 1062 DEB(printf("ipfw: unlink entry 0x%08x %d -> 0x%08x %d, %d left\n",\ 1063 (q->id.src_ip), (q->id.src_port), \ 1064 (q->id.dst_ip), (q->id.dst_port), dyn_count-1 ); ) \ 1065 if (prev != NULL) \ 1066 prev->next = q = q->next; \ 1067 else \ 1068 head = q = q->next; \ 1069 dyn_count--; \ 1070 uma_zfree(ipfw_dyn_rule_zone, old_q); } 1071 1072#define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0) 1073 1074/** 1075 * Remove dynamic rules pointing to "rule", or all of them if rule == NULL. 1076 * 1077 * If keep_me == NULL, rules are deleted even if not expired, 1078 * otherwise only expired rules are removed. 1079 * 1080 * The value of the second parameter is also used to point to identify 1081 * a rule we absolutely do not want to remove (e.g. because we are 1082 * holding a reference to it -- this is the case with O_LIMIT_PARENT 1083 * rules). The pointer is only used for comparison, so any non-null 1084 * value will do. 1085 */ 1086static void 1087remove_dyn_rule(struct ip_fw *rule, ipfw_dyn_rule *keep_me) 1088{ 1089 static u_int32_t last_remove = 0; 1090 1091#define FORCE (keep_me == NULL) 1092 1093 ipfw_dyn_rule *prev, *q; 1094 int i, pass = 0, max_pass = 0; 1095 1096 IPFW_DYN_LOCK_ASSERT(); 1097 1098 if (ipfw_dyn_v == NULL || dyn_count == 0) 1099 return; 1100 /* do not expire more than once per second, it is useless */ 1101 if (!FORCE && last_remove == time_uptime) 1102 return; 1103 last_remove = time_uptime; 1104 1105 /* 1106 * because O_LIMIT refer to parent rules, during the first pass only 1107 * remove child and mark any pending LIMIT_PARENT, and remove 1108 * them in a second pass. 1109 */ 1110next_pass: 1111 for (i = 0 ; i < curr_dyn_buckets ; i++) { 1112 for (prev=NULL, q = ipfw_dyn_v[i] ; q ; ) { 1113 /* 1114 * Logic can become complex here, so we split tests. 1115 */ 1116 if (q == keep_me) 1117 goto next; 1118 if (rule != NULL && rule != q->rule) 1119 goto next; /* not the one we are looking for */ 1120 if (q->dyn_type == O_LIMIT_PARENT) { 1121 /* 1122 * handle parent in the second pass, 1123 * record we need one. 1124 */ 1125 max_pass = 1; 1126 if (pass == 0) 1127 goto next; 1128 if (FORCE && q->count != 0 ) { 1129 /* XXX should not happen! */ 1130 printf("ipfw: OUCH! cannot remove rule," 1131 " count %d\n", q->count); 1132 } 1133 } else { 1134 if (!FORCE && 1135 !TIME_LEQ( q->expire, time_uptime )) 1136 goto next; 1137 } 1138 if (q->dyn_type != O_LIMIT_PARENT || !q->count) { 1139 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q); 1140 continue; 1141 } 1142next: 1143 prev=q; 1144 q=q->next; 1145 } 1146 } 1147 if (pass++ < max_pass) 1148 goto next_pass; 1149} 1150 1151 1152/** 1153 * lookup a dynamic rule. 1154 */ 1155static ipfw_dyn_rule * 1156lookup_dyn_rule_locked(struct ipfw_flow_id *pkt, int *match_direction, 1157 struct tcphdr *tcp) 1158{ 1159 /* 1160 * stateful ipfw extensions. 1161 * Lookup into dynamic session queue 1162 */ 1163#define MATCH_REVERSE 0 1164#define MATCH_FORWARD 1 1165#define MATCH_NONE 2 1166#define MATCH_UNKNOWN 3 1167 int i, dir = MATCH_NONE; 1168 ipfw_dyn_rule *prev, *q=NULL; 1169 1170 IPFW_DYN_LOCK_ASSERT(); 1171 1172 if (ipfw_dyn_v == NULL) 1173 goto done; /* not found */ 1174 i = hash_packet( pkt ); 1175 for (prev=NULL, q = ipfw_dyn_v[i] ; q != NULL ; ) { 1176 if (q->dyn_type == O_LIMIT_PARENT && q->count) 1177 goto next; 1178 if (TIME_LEQ( q->expire, time_uptime)) { /* expire entry */ 1179 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q); 1180 continue; 1181 } 1182 if (pkt->proto == q->id.proto && 1183 q->dyn_type != O_LIMIT_PARENT) { 1184 if (IS_IP6_FLOW_ID(pkt)) { 1185 if (IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1186 &(q->id.src_ip6)) && 1187 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1188 &(q->id.dst_ip6)) && 1189 pkt->src_port == q->id.src_port && 1190 pkt->dst_port == q->id.dst_port ) { 1191 dir = MATCH_FORWARD; 1192 break; 1193 } 1194 if (IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1195 &(q->id.dst_ip6)) && 1196 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1197 &(q->id.src_ip6)) && 1198 pkt->src_port == q->id.dst_port && 1199 pkt->dst_port == q->id.src_port ) { 1200 dir = MATCH_REVERSE; 1201 break; 1202 } 1203 } else { 1204 if (pkt->src_ip == q->id.src_ip && 1205 pkt->dst_ip == q->id.dst_ip && 1206 pkt->src_port == q->id.src_port && 1207 pkt->dst_port == q->id.dst_port ) { 1208 dir = MATCH_FORWARD; 1209 break; 1210 } 1211 if (pkt->src_ip == q->id.dst_ip && 1212 pkt->dst_ip == q->id.src_ip && 1213 pkt->src_port == q->id.dst_port && 1214 pkt->dst_port == q->id.src_port ) { 1215 dir = MATCH_REVERSE; 1216 break; 1217 } 1218 } 1219 } 1220next: 1221 prev = q; 1222 q = q->next; 1223 } 1224 if (q == NULL) 1225 goto done; /* q = NULL, not found */ 1226 1227 if ( prev != NULL) { /* found and not in front */ 1228 prev->next = q->next; 1229 q->next = ipfw_dyn_v[i]; 1230 ipfw_dyn_v[i] = q; 1231 } 1232 if (pkt->proto == IPPROTO_TCP) { /* update state according to flags */ 1233 u_char flags = pkt->flags & (TH_FIN|TH_SYN|TH_RST); 1234 1235#define BOTH_SYN (TH_SYN | (TH_SYN << 8)) 1236#define BOTH_FIN (TH_FIN | (TH_FIN << 8)) 1237 q->state |= (dir == MATCH_FORWARD ) ? flags : (flags << 8); 1238 switch (q->state) { 1239 case TH_SYN: /* opening */ 1240 q->expire = time_uptime + dyn_syn_lifetime; 1241 break; 1242 1243 case BOTH_SYN: /* move to established */ 1244 case BOTH_SYN | TH_FIN : /* one side tries to close */ 1245 case BOTH_SYN | (TH_FIN << 8) : 1246 if (tcp) { 1247#define _SEQ_GE(a,b) ((int)(a) - (int)(b) >= 0) 1248 u_int32_t ack = ntohl(tcp->th_ack); 1249 if (dir == MATCH_FORWARD) { 1250 if (q->ack_fwd == 0 || _SEQ_GE(ack, q->ack_fwd)) 1251 q->ack_fwd = ack; 1252 else { /* ignore out-of-sequence */ 1253 break; 1254 } 1255 } else { 1256 if (q->ack_rev == 0 || _SEQ_GE(ack, q->ack_rev)) 1257 q->ack_rev = ack; 1258 else { /* ignore out-of-sequence */ 1259 break; 1260 } 1261 } 1262 } 1263 q->expire = time_uptime + dyn_ack_lifetime; 1264 break; 1265 1266 case BOTH_SYN | BOTH_FIN: /* both sides closed */ 1267 if (dyn_fin_lifetime >= dyn_keepalive_period) 1268 dyn_fin_lifetime = dyn_keepalive_period - 1; 1269 q->expire = time_uptime + dyn_fin_lifetime; 1270 break; 1271 1272 default: 1273#if 0 1274 /* 1275 * reset or some invalid combination, but can also 1276 * occur if we use keep-state the wrong way. 1277 */ 1278 if ( (q->state & ((TH_RST << 8)|TH_RST)) == 0) 1279 printf("invalid state: 0x%x\n", q->state); 1280#endif 1281 if (dyn_rst_lifetime >= dyn_keepalive_period) 1282 dyn_rst_lifetime = dyn_keepalive_period - 1; 1283 q->expire = time_uptime + dyn_rst_lifetime; 1284 break; 1285 } 1286 } else if (pkt->proto == IPPROTO_UDP) { 1287 q->expire = time_uptime + dyn_udp_lifetime; 1288 } else { 1289 /* other protocols */ 1290 q->expire = time_uptime + dyn_short_lifetime; 1291 } 1292done: 1293 if (match_direction) 1294 *match_direction = dir; 1295 return q; 1296} 1297 1298static ipfw_dyn_rule * 1299lookup_dyn_rule(struct ipfw_flow_id *pkt, int *match_direction, 1300 struct tcphdr *tcp) 1301{ 1302 ipfw_dyn_rule *q; 1303 1304 IPFW_DYN_LOCK(); 1305 q = lookup_dyn_rule_locked(pkt, match_direction, tcp); 1306 if (q == NULL) 1307 IPFW_DYN_UNLOCK(); 1308 /* NB: return table locked when q is not NULL */ 1309 return q; 1310} 1311 1312static void 1313realloc_dynamic_table(void) 1314{ 1315 IPFW_DYN_LOCK_ASSERT(); 1316 1317 /* 1318 * Try reallocation, make sure we have a power of 2 and do 1319 * not allow more than 64k entries. In case of overflow, 1320 * default to 1024. 1321 */ 1322 1323 if (dyn_buckets > 65536) 1324 dyn_buckets = 1024; 1325 if ((dyn_buckets & (dyn_buckets-1)) != 0) { /* not a power of 2 */ 1326 dyn_buckets = curr_dyn_buckets; /* reset */ 1327 return; 1328 } 1329 curr_dyn_buckets = dyn_buckets; 1330 if (ipfw_dyn_v != NULL) 1331 free(ipfw_dyn_v, M_IPFW); 1332 for (;;) { 1333 ipfw_dyn_v = malloc(curr_dyn_buckets * sizeof(ipfw_dyn_rule *), 1334 M_IPFW, M_NOWAIT | M_ZERO); 1335 if (ipfw_dyn_v != NULL || curr_dyn_buckets <= 2) 1336 break; 1337 curr_dyn_buckets /= 2; 1338 } 1339} 1340 1341/** 1342 * Install state of type 'type' for a dynamic session. 1343 * The hash table contains two type of rules: 1344 * - regular rules (O_KEEP_STATE) 1345 * - rules for sessions with limited number of sess per user 1346 * (O_LIMIT). When they are created, the parent is 1347 * increased by 1, and decreased on delete. In this case, 1348 * the third parameter is the parent rule and not the chain. 1349 * - "parent" rules for the above (O_LIMIT_PARENT). 1350 */ 1351static ipfw_dyn_rule * 1352add_dyn_rule(struct ipfw_flow_id *id, u_int8_t dyn_type, struct ip_fw *rule) 1353{ 1354 ipfw_dyn_rule *r; 1355 int i; 1356 1357 IPFW_DYN_LOCK_ASSERT(); 1358 1359 if (ipfw_dyn_v == NULL || 1360 (dyn_count == 0 && dyn_buckets != curr_dyn_buckets)) { 1361 realloc_dynamic_table(); 1362 if (ipfw_dyn_v == NULL) 1363 return NULL; /* failed ! */ 1364 } 1365 i = hash_packet(id); 1366 1367 r = uma_zalloc(ipfw_dyn_rule_zone, M_NOWAIT | M_ZERO); 1368 if (r == NULL) { 1369 printf ("ipfw: sorry cannot allocate state\n"); 1370 return NULL; 1371 } 1372 1373 /* increase refcount on parent, and set pointer */ 1374 if (dyn_type == O_LIMIT) { 1375 ipfw_dyn_rule *parent = (ipfw_dyn_rule *)rule; 1376 if ( parent->dyn_type != O_LIMIT_PARENT) 1377 panic("invalid parent"); 1378 parent->count++; 1379 r->parent = parent; 1380 rule = parent->rule; 1381 } 1382 1383 r->id = *id; 1384 r->expire = time_uptime + dyn_syn_lifetime; 1385 r->rule = rule; 1386 r->dyn_type = dyn_type; 1387 r->pcnt = r->bcnt = 0; 1388 r->count = 0; 1389 1390 r->bucket = i; 1391 r->next = ipfw_dyn_v[i]; 1392 ipfw_dyn_v[i] = r; 1393 dyn_count++; 1394 DEB(printf("ipfw: add dyn entry ty %d 0x%08x %d -> 0x%08x %d, total %d\n", 1395 dyn_type, 1396 (r->id.src_ip), (r->id.src_port), 1397 (r->id.dst_ip), (r->id.dst_port), 1398 dyn_count ); ) 1399 return r; 1400} 1401 1402/** 1403 * lookup dynamic parent rule using pkt and rule as search keys. 1404 * If the lookup fails, then install one. 1405 */ 1406static ipfw_dyn_rule * 1407lookup_dyn_parent(struct ipfw_flow_id *pkt, struct ip_fw *rule) 1408{ 1409 ipfw_dyn_rule *q; 1410 int i; 1411 1412 IPFW_DYN_LOCK_ASSERT(); 1413 1414 if (ipfw_dyn_v) { 1415 int is_v6 = IS_IP6_FLOW_ID(pkt); 1416 i = hash_packet( pkt ); 1417 for (q = ipfw_dyn_v[i] ; q != NULL ; q=q->next) 1418 if (q->dyn_type == O_LIMIT_PARENT && 1419 rule== q->rule && 1420 pkt->proto == q->id.proto && 1421 pkt->src_port == q->id.src_port && 1422 pkt->dst_port == q->id.dst_port && 1423 ( 1424 (is_v6 && 1425 IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1426 &(q->id.src_ip6)) && 1427 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1428 &(q->id.dst_ip6))) || 1429 (!is_v6 && 1430 pkt->src_ip == q->id.src_ip && 1431 pkt->dst_ip == q->id.dst_ip) 1432 ) 1433 ) { 1434 q->expire = time_uptime + dyn_short_lifetime; 1435 DEB(printf("ipfw: lookup_dyn_parent found 0x%p\n",q);) 1436 return q; 1437 } 1438 } 1439 return add_dyn_rule(pkt, O_LIMIT_PARENT, rule); 1440} 1441 1442/** 1443 * Install dynamic state for rule type cmd->o.opcode 1444 * 1445 * Returns 1 (failure) if state is not installed because of errors or because 1446 * session limitations are enforced. 1447 */ 1448static int 1449install_state(struct ip_fw *rule, ipfw_insn_limit *cmd, 1450 struct ip_fw_args *args, uint32_t tablearg) 1451{ 1452 static int last_log; 1453 ipfw_dyn_rule *q; 1454 struct in_addr da; 1455 char src[48], dst[48]; 1456 1457 src[0] = '\0'; 1458 dst[0] = '\0'; 1459 1460 DEB( 1461 printf("ipfw: %s: type %d 0x%08x %u -> 0x%08x %u\n", 1462 __func__, cmd->o.opcode, 1463 (args->f_id.src_ip), (args->f_id.src_port), 1464 (args->f_id.dst_ip), (args->f_id.dst_port)); 1465 ) 1466 1467 IPFW_DYN_LOCK(); 1468 1469 q = lookup_dyn_rule_locked(&args->f_id, NULL, NULL); 1470 1471 if (q != NULL) { /* should never occur */ 1472 if (last_log != time_uptime) { 1473 last_log = time_uptime; 1474 printf("ipfw: %s: entry already present, done\n", 1475 __func__); 1476 } 1477 IPFW_DYN_UNLOCK(); 1478 return (0); 1479 } 1480 1481 if (dyn_count >= dyn_max) 1482 /* Run out of slots, try to remove any expired rule. */ 1483 remove_dyn_rule(NULL, (ipfw_dyn_rule *)1); 1484 1485 if (dyn_count >= dyn_max) { 1486 if (last_log != time_uptime) { 1487 last_log = time_uptime; 1488 printf("ipfw: %s: Too many dynamic rules\n", __func__); 1489 } 1490 IPFW_DYN_UNLOCK(); 1491 return (1); /* cannot install, notify caller */ 1492 } 1493 1494 switch (cmd->o.opcode) { 1495 case O_KEEP_STATE: /* bidir rule */ 1496 add_dyn_rule(&args->f_id, O_KEEP_STATE, rule); 1497 break; 1498 1499 case O_LIMIT: { /* limit number of sessions */ 1500 struct ipfw_flow_id id; 1501 ipfw_dyn_rule *parent; 1502 uint32_t conn_limit; 1503 uint16_t limit_mask = cmd->limit_mask; 1504 1505 conn_limit = (cmd->conn_limit == IP_FW_TABLEARG) ? 1506 tablearg : cmd->conn_limit; 1507 1508 DEB( 1509 if (cmd->conn_limit == IP_FW_TABLEARG) 1510 printf("ipfw: %s: O_LIMIT rule, conn_limit: %u " 1511 "(tablearg)\n", __func__, conn_limit); 1512 else 1513 printf("ipfw: %s: O_LIMIT rule, conn_limit: %u\n", 1514 __func__, conn_limit); 1515 ) 1516 1517 id.dst_ip = id.src_ip = id.dst_port = id.src_port = 0; 1518 id.proto = args->f_id.proto; 1519 id.addr_type = args->f_id.addr_type; 1520 1521 if (IS_IP6_FLOW_ID (&(args->f_id))) { 1522 if (limit_mask & DYN_SRC_ADDR) 1523 id.src_ip6 = args->f_id.src_ip6; 1524 if (limit_mask & DYN_DST_ADDR) 1525 id.dst_ip6 = args->f_id.dst_ip6; 1526 } else { 1527 if (limit_mask & DYN_SRC_ADDR) 1528 id.src_ip = args->f_id.src_ip; 1529 if (limit_mask & DYN_DST_ADDR) 1530 id.dst_ip = args->f_id.dst_ip; 1531 } 1532 if (limit_mask & DYN_SRC_PORT) 1533 id.src_port = args->f_id.src_port; 1534 if (limit_mask & DYN_DST_PORT) 1535 id.dst_port = args->f_id.dst_port; 1536 if ((parent = lookup_dyn_parent(&id, rule)) == NULL) { 1537 printf("ipfw: %s: add parent failed\n", __func__); 1538 IPFW_DYN_UNLOCK(); 1539 return (1); 1540 } 1541 1542 if (parent->count >= conn_limit) { 1543 /* See if we can remove some expired rule. */ 1544 remove_dyn_rule(rule, parent); 1545 if (parent->count >= conn_limit) { 1546 if (fw_verbose && last_log != time_uptime) { 1547 last_log = time_uptime; 1548#ifdef INET6 1549 /* 1550 * XXX IPv6 flows are not 1551 * supported yet. 1552 */ 1553 if (IS_IP6_FLOW_ID(&(args->f_id))) { 1554 char ip6buf[INET6_ADDRSTRLEN]; 1555 snprintf(src, sizeof(src), 1556 "[%s]", ip6_sprintf(ip6buf, 1557 &args->f_id.src_ip6)); 1558 snprintf(dst, sizeof(dst), 1559 "[%s]", ip6_sprintf(ip6buf, 1560 &args->f_id.dst_ip6)); 1561 } else 1562#endif 1563 { 1564 da.s_addr = 1565 htonl(args->f_id.src_ip); 1566 inet_ntoa_r(da, src); 1567 da.s_addr = 1568 htonl(args->f_id.dst_ip); 1569 inet_ntoa_r(da, dst); 1570 } 1571 log(LOG_SECURITY | LOG_DEBUG, 1572 "%s %s:%u -> %s:%u, %s\n", 1573 "drop session", 1574 src, (args->f_id.src_port), 1575 dst, (args->f_id.dst_port), 1576 "too many entries"); 1577 } 1578 IPFW_DYN_UNLOCK(); 1579 return (1); 1580 } 1581 } 1582 add_dyn_rule(&args->f_id, O_LIMIT, (struct ip_fw *)parent); 1583 break; 1584 } 1585 default: 1586 printf("ipfw: %s: unknown dynamic rule type %u\n", 1587 __func__, cmd->o.opcode); 1588 IPFW_DYN_UNLOCK(); 1589 return (1); 1590 } 1591 1592 /* XXX just set lifetime */ 1593 lookup_dyn_rule_locked(&args->f_id, NULL, NULL); 1594 1595 IPFW_DYN_UNLOCK(); 1596 return (0); 1597} 1598 1599/* 1600 * Generate a TCP packet, containing either a RST or a keepalive. 1601 * When flags & TH_RST, we are sending a RST packet, because of a 1602 * "reset" action matched the packet. 1603 * Otherwise we are sending a keepalive, and flags & TH_ 1604 * The 'replyto' mbuf is the mbuf being replied to, if any, and is required 1605 * so that MAC can label the reply appropriately. 1606 */ 1607static struct mbuf * 1608send_pkt(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t seq, 1609 u_int32_t ack, int flags) 1610{ 1611 struct mbuf *m; 1612 struct ip *ip; 1613 struct tcphdr *tcp; 1614 1615 MGETHDR(m, M_DONTWAIT, MT_DATA); 1616 if (m == 0) 1617 return (NULL); 1618 m->m_pkthdr.rcvif = (struct ifnet *)0; 1619 1620#ifdef MAC 1621 if (replyto != NULL) 1622 mac_create_mbuf_netlayer(replyto, m); 1623 else 1624 mac_create_mbuf_from_firewall(m); 1625#else 1626 (void)replyto; /* don't warn about unused arg */ 1627#endif 1628 1629 m->m_pkthdr.len = m->m_len = sizeof(struct ip) + sizeof(struct tcphdr); 1630 m->m_data += max_linkhdr; 1631 1632 ip = mtod(m, struct ip *); 1633 bzero(ip, m->m_len); 1634 tcp = (struct tcphdr *)(ip + 1); /* no IP options */ 1635 ip->ip_p = IPPROTO_TCP; 1636 tcp->th_off = 5; 1637 /* 1638 * Assume we are sending a RST (or a keepalive in the reverse 1639 * direction), swap src and destination addresses and ports. 1640 */ 1641 ip->ip_src.s_addr = htonl(id->dst_ip); 1642 ip->ip_dst.s_addr = htonl(id->src_ip); 1643 tcp->th_sport = htons(id->dst_port); 1644 tcp->th_dport = htons(id->src_port); 1645 if (flags & TH_RST) { /* we are sending a RST */ 1646 if (flags & TH_ACK) { 1647 tcp->th_seq = htonl(ack); 1648 tcp->th_ack = htonl(0); 1649 tcp->th_flags = TH_RST; 1650 } else { 1651 if (flags & TH_SYN) 1652 seq++; 1653 tcp->th_seq = htonl(0); 1654 tcp->th_ack = htonl(seq); 1655 tcp->th_flags = TH_RST | TH_ACK; 1656 } 1657 } else { 1658 /* 1659 * We are sending a keepalive. flags & TH_SYN determines 1660 * the direction, forward if set, reverse if clear. 1661 * NOTE: seq and ack are always assumed to be correct 1662 * as set by the caller. This may be confusing... 1663 */ 1664 if (flags & TH_SYN) { 1665 /* 1666 * we have to rewrite the correct addresses! 1667 */ 1668 ip->ip_dst.s_addr = htonl(id->dst_ip); 1669 ip->ip_src.s_addr = htonl(id->src_ip); 1670 tcp->th_dport = htons(id->dst_port); 1671 tcp->th_sport = htons(id->src_port); 1672 } 1673 tcp->th_seq = htonl(seq); 1674 tcp->th_ack = htonl(ack); 1675 tcp->th_flags = TH_ACK; 1676 } 1677 /* 1678 * set ip_len to the payload size so we can compute 1679 * the tcp checksum on the pseudoheader 1680 * XXX check this, could save a couple of words ? 1681 */ 1682 ip->ip_len = htons(sizeof(struct tcphdr)); 1683 tcp->th_sum = in_cksum(m, m->m_pkthdr.len); 1684 /* 1685 * now fill fields left out earlier 1686 */ 1687 ip->ip_ttl = ip_defttl; 1688 ip->ip_len = m->m_pkthdr.len; 1689 m->m_flags |= M_SKIP_FIREWALL; 1690 return (m); 1691} 1692 1693/* 1694 * sends a reject message, consuming the mbuf passed as an argument. 1695 */ 1696static void 1697send_reject(struct ip_fw_args *args, int code, int ip_len, struct ip *ip) 1698{ 1699 1700#if 0 1701 /* XXX When ip is not guaranteed to be at mtod() we will 1702 * need to account for this */ 1703 * The mbuf will however be thrown away so we can adjust it. 1704 * Remember we did an m_pullup on it already so we 1705 * can make some assumptions about contiguousness. 1706 */ 1707 if (args->L3offset) 1708 m_adj(m, args->L3offset); 1709#endif 1710 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */ 1711 /* We need the IP header in host order for icmp_error(). */ 1712 if (args->eh != NULL) { 1713 ip->ip_len = ntohs(ip->ip_len); 1714 ip->ip_off = ntohs(ip->ip_off); 1715 } 1716 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 1717 } else if (args->f_id.proto == IPPROTO_TCP) { 1718 struct tcphdr *const tcp = 1719 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 1720 if ( (tcp->th_flags & TH_RST) == 0) { 1721 struct mbuf *m; 1722 m = send_pkt(args->m, &(args->f_id), 1723 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 1724 tcp->th_flags | TH_RST); 1725 if (m != NULL) 1726 ip_output(m, NULL, NULL, 0, NULL, NULL); 1727 } 1728 m_freem(args->m); 1729 } else 1730 m_freem(args->m); 1731 args->m = NULL; 1732} 1733 1734/** 1735 * 1736 * Given an ip_fw *, lookup_next_rule will return a pointer 1737 * to the next rule, which can be either the jump 1738 * target (for skipto instructions) or the next one in the list (in 1739 * all other cases including a missing jump target). 1740 * The result is also written in the "next_rule" field of the rule. 1741 * Backward jumps are not allowed, so start looking from the next 1742 * rule... 1743 * 1744 * This never returns NULL -- in case we do not have an exact match, 1745 * the next rule is returned. When the ruleset is changed, 1746 * pointers are flushed so we are always correct. 1747 */ 1748 1749static struct ip_fw * 1750lookup_next_rule(struct ip_fw *me) 1751{ 1752 struct ip_fw *rule = NULL; 1753 ipfw_insn *cmd; 1754 1755 /* look for action, in case it is a skipto */ 1756 cmd = ACTION_PTR(me); 1757 if (cmd->opcode == O_LOG) 1758 cmd += F_LEN(cmd); 1759 if (cmd->opcode == O_ALTQ) 1760 cmd += F_LEN(cmd); 1761 if (cmd->opcode == O_TAG) 1762 cmd += F_LEN(cmd); 1763 if ( cmd->opcode == O_SKIPTO ) 1764 for (rule = me->next; rule ; rule = rule->next) 1765 if (rule->rulenum >= cmd->arg1) 1766 break; 1767 if (rule == NULL) /* failure or not a skipto */ 1768 rule = me->next; 1769 me->next_rule = rule; 1770 return rule; 1771} 1772 1773static int 1774add_table_entry(struct ip_fw_chain *ch, uint16_t tbl, in_addr_t addr, 1775 uint8_t mlen, uint32_t value) 1776{ 1777 struct radix_node_head *rnh; 1778 struct table_entry *ent; 1779 1780 if (tbl >= IPFW_TABLES_MAX) 1781 return (EINVAL); 1782 rnh = ch->tables[tbl]; 1783 ent = malloc(sizeof(*ent), M_IPFW_TBL, M_NOWAIT | M_ZERO); 1784 if (ent == NULL) 1785 return (ENOMEM); 1786 ent->value = value; 1787 ent->addr.sin_len = ent->mask.sin_len = 8; 1788 ent->mask.sin_addr.s_addr = htonl(mlen ? ~((1 << (32 - mlen)) - 1) : 0); 1789 ent->addr.sin_addr.s_addr = addr & ent->mask.sin_addr.s_addr; 1790 IPFW_WLOCK(&layer3_chain); 1791 if (rnh->rnh_addaddr(&ent->addr, &ent->mask, rnh, (void *)ent) == 1792 NULL) { 1793 IPFW_WUNLOCK(&layer3_chain); 1794 free(ent, M_IPFW_TBL); 1795 return (EEXIST); 1796 } 1797 IPFW_WUNLOCK(&layer3_chain); 1798 return (0); 1799} 1800 1801static int 1802del_table_entry(struct ip_fw_chain *ch, uint16_t tbl, in_addr_t addr, 1803 uint8_t mlen) 1804{ 1805 struct radix_node_head *rnh; 1806 struct table_entry *ent; 1807 struct sockaddr_in sa, mask; 1808 1809 if (tbl >= IPFW_TABLES_MAX) 1810 return (EINVAL); 1811 rnh = ch->tables[tbl]; 1812 sa.sin_len = mask.sin_len = 8; 1813 mask.sin_addr.s_addr = htonl(mlen ? ~((1 << (32 - mlen)) - 1) : 0); 1814 sa.sin_addr.s_addr = addr & mask.sin_addr.s_addr; 1815 IPFW_WLOCK(ch); 1816 ent = (struct table_entry *)rnh->rnh_deladdr(&sa, &mask, rnh); 1817 if (ent == NULL) { 1818 IPFW_WUNLOCK(ch); 1819 return (ESRCH); 1820 } 1821 IPFW_WUNLOCK(ch); 1822 free(ent, M_IPFW_TBL); 1823 return (0); 1824} 1825 1826static int 1827flush_table_entry(struct radix_node *rn, void *arg) 1828{ 1829 struct radix_node_head * const rnh = arg; 1830 struct table_entry *ent; 1831 1832 ent = (struct table_entry *) 1833 rnh->rnh_deladdr(rn->rn_key, rn->rn_mask, rnh); 1834 if (ent != NULL) 1835 free(ent, M_IPFW_TBL); 1836 return (0); 1837} 1838 1839static int 1840flush_table(struct ip_fw_chain *ch, uint16_t tbl) 1841{ 1842 struct radix_node_head *rnh; 1843 1844 IPFW_WLOCK_ASSERT(ch); 1845 1846 if (tbl >= IPFW_TABLES_MAX) 1847 return (EINVAL); 1848 rnh = ch->tables[tbl]; 1849 KASSERT(rnh != NULL, ("NULL IPFW table")); 1850 rnh->rnh_walktree(rnh, flush_table_entry, rnh); 1851 return (0); 1852} 1853 1854static void 1855flush_tables(struct ip_fw_chain *ch) 1856{ 1857 uint16_t tbl; 1858 1859 IPFW_WLOCK_ASSERT(ch); 1860 1861 for (tbl = 0; tbl < IPFW_TABLES_MAX; tbl++) 1862 flush_table(ch, tbl); 1863} 1864 1865static int 1866init_tables(struct ip_fw_chain *ch) 1867{ 1868 int i; 1869 uint16_t j; 1870 1871 for (i = 0; i < IPFW_TABLES_MAX; i++) { 1872 if (!rn_inithead((void **)&ch->tables[i], 32)) { 1873 for (j = 0; j < i; j++) { 1874 (void) flush_table(ch, j); 1875 } 1876 return (ENOMEM); 1877 } 1878 } 1879 return (0); 1880} 1881 1882static int 1883lookup_table(struct ip_fw_chain *ch, uint16_t tbl, in_addr_t addr, 1884 uint32_t *val) 1885{ 1886 struct radix_node_head *rnh; 1887 struct table_entry *ent; 1888 struct sockaddr_in sa; 1889 1890 if (tbl >= IPFW_TABLES_MAX) 1891 return (0); 1892 rnh = ch->tables[tbl]; 1893 sa.sin_len = 8; 1894 sa.sin_addr.s_addr = addr; 1895 ent = (struct table_entry *)(rnh->rnh_lookup(&sa, NULL, rnh)); 1896 if (ent != NULL) { 1897 *val = ent->value; 1898 return (1); 1899 } 1900 return (0); 1901} 1902 1903static int 1904count_table_entry(struct radix_node *rn, void *arg) 1905{ 1906 u_int32_t * const cnt = arg; 1907 1908 (*cnt)++; 1909 return (0); 1910} 1911 1912static int 1913count_table(struct ip_fw_chain *ch, uint32_t tbl, uint32_t *cnt) 1914{ 1915 struct radix_node_head *rnh; 1916 1917 if (tbl >= IPFW_TABLES_MAX) 1918 return (EINVAL); 1919 rnh = ch->tables[tbl]; 1920 *cnt = 0; 1921 rnh->rnh_walktree(rnh, count_table_entry, cnt); 1922 return (0); 1923} 1924 1925static int 1926dump_table_entry(struct radix_node *rn, void *arg) 1927{ 1928 struct table_entry * const n = (struct table_entry *)rn; 1929 ipfw_table * const tbl = arg; 1930 ipfw_table_entry *ent; 1931 1932 if (tbl->cnt == tbl->size) 1933 return (1); 1934 ent = &tbl->ent[tbl->cnt]; 1935 ent->tbl = tbl->tbl; 1936 if (in_nullhost(n->mask.sin_addr)) 1937 ent->masklen = 0; 1938 else 1939 ent->masklen = 33 - ffs(ntohl(n->mask.sin_addr.s_addr)); 1940 ent->addr = n->addr.sin_addr.s_addr; 1941 ent->value = n->value; 1942 tbl->cnt++; 1943 return (0); 1944} 1945 1946static int 1947dump_table(struct ip_fw_chain *ch, ipfw_table *tbl) 1948{ 1949 struct radix_node_head *rnh; 1950 1951 if (tbl->tbl >= IPFW_TABLES_MAX) 1952 return (EINVAL); 1953 rnh = ch->tables[tbl->tbl]; 1954 tbl->cnt = 0; 1955 rnh->rnh_walktree(rnh, dump_table_entry, tbl); 1956 return (0); 1957} 1958 1959static void 1960fill_ugid_cache(struct inpcb *inp, struct ip_fw_ugid *ugp) 1961{ 1962 struct ucred *cr; 1963 1964 if (inp->inp_socket != NULL) { 1965 cr = inp->inp_socket->so_cred; 1966 ugp->fw_prid = jailed(cr) ? 1967 cr->cr_prison->pr_id : -1; 1968 ugp->fw_uid = cr->cr_uid; 1969 ugp->fw_ngroups = cr->cr_ngroups; 1970 bcopy(cr->cr_groups, ugp->fw_groups, 1971 sizeof(ugp->fw_groups)); 1972 } 1973} 1974 1975static int 1976check_uidgid(ipfw_insn_u32 *insn, int proto, struct ifnet *oif, 1977 struct in_addr dst_ip, u_int16_t dst_port, struct in_addr src_ip, 1978 u_int16_t src_port, struct ip_fw_ugid *ugp, int *lookup, 1979 struct inpcb *inp) 1980{ 1981 struct inpcbinfo *pi; 1982 int wildcard; 1983 struct inpcb *pcb; 1984 int match; 1985 gid_t *gp; 1986 1987 /* 1988 * Check to see if the UDP or TCP stack supplied us with 1989 * the PCB. If so, rather then holding a lock and looking 1990 * up the PCB, we can use the one that was supplied. 1991 */ 1992 if (inp && *lookup == 0) { 1993 INP_LOCK_ASSERT(inp); 1994 if (inp->inp_socket != NULL) { 1995 fill_ugid_cache(inp, ugp); 1996 *lookup = 1; 1997 } 1998 } 1999 /* 2000 * If we have already been here and the packet has no 2001 * PCB entry associated with it, then we can safely 2002 * assume that this is a no match. 2003 */ 2004 if (*lookup == -1) 2005 return (0); 2006 if (proto == IPPROTO_TCP) { 2007 wildcard = 0; 2008 pi = &tcbinfo; 2009 } else if (proto == IPPROTO_UDP) { 2010 wildcard = INPLOOKUP_WILDCARD; 2011 pi = &udbinfo; 2012 } else 2013 return 0; 2014 match = 0; 2015 if (*lookup == 0) { 2016 INP_INFO_RLOCK(pi); 2017 pcb = (oif) ? 2018 in_pcblookup_hash(pi, 2019 dst_ip, htons(dst_port), 2020 src_ip, htons(src_port), 2021 wildcard, oif) : 2022 in_pcblookup_hash(pi, 2023 src_ip, htons(src_port), 2024 dst_ip, htons(dst_port), 2025 wildcard, NULL); 2026 if (pcb != NULL) { 2027 INP_LOCK(pcb); 2028 if (pcb->inp_socket != NULL) { 2029 fill_ugid_cache(pcb, ugp); 2030 *lookup = 1; 2031 } 2032 INP_UNLOCK(pcb); 2033 } 2034 INP_INFO_RUNLOCK(pi); 2035 if (*lookup == 0) { 2036 /* 2037 * If the lookup did not yield any results, there 2038 * is no sense in coming back and trying again. So 2039 * we can set lookup to -1 and ensure that we wont 2040 * bother the pcb system again. 2041 */ 2042 *lookup = -1; 2043 return (0); 2044 } 2045 } 2046 if (insn->o.opcode == O_UID) 2047 match = (ugp->fw_uid == (uid_t)insn->d[0]); 2048 else if (insn->o.opcode == O_GID) { 2049 for (gp = ugp->fw_groups; 2050 gp < &ugp->fw_groups[ugp->fw_ngroups]; gp++) 2051 if (*gp == (gid_t)insn->d[0]) { 2052 match = 1; 2053 break; 2054 } 2055 } else if (insn->o.opcode == O_JAIL) 2056 match = (ugp->fw_prid == (int)insn->d[0]); 2057 return match; 2058} 2059 2060#ifdef IPFIREWALL_NAT 2061static eventhandler_tag ifaddr_event_tag; 2062 2063static void 2064ifaddr_change(void *arg __unused, struct ifnet *ifp) 2065{ 2066 struct cfg_nat *ptr; 2067 struct ifaddr *ifa; 2068 2069 IPFW_WLOCK(&layer3_chain); 2070 /* Check every nat entry... */ 2071 LIST_FOREACH(ptr, &layer3_chain.nat, _next) { 2072 /* ...using nic 'ifp->if_xname' as dynamic alias address. */ 2073 if (strncmp(ptr->if_name, ifp->if_xname, IF_NAMESIZE) == 0) { 2074 mtx_lock(&ifp->if_addr_mtx); 2075 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 2076 if (ifa->ifa_addr == NULL) 2077 continue; 2078 if (ifa->ifa_addr->sa_family != AF_INET) 2079 continue; 2080 ptr->ip = ((struct sockaddr_in *) 2081 (ifa->ifa_addr))->sin_addr; 2082 LibAliasSetAddress(ptr->lib, ptr->ip); 2083 } 2084 mtx_unlock(&ifp->if_addr_mtx); 2085 } 2086 } 2087 IPFW_WUNLOCK(&layer3_chain); 2088} 2089 2090static void 2091flush_nat_ptrs(const int i) 2092{ 2093 struct ip_fw *rule; 2094 2095 IPFW_WLOCK_ASSERT(&layer3_chain); 2096 for (rule = layer3_chain.rules; rule; rule = rule->next) { 2097 ipfw_insn_nat *cmd = (ipfw_insn_nat *)ACTION_PTR(rule); 2098 if (cmd->o.opcode != O_NAT) 2099 continue; 2100 if (cmd->nat != NULL && cmd->nat->id == i) 2101 cmd->nat = NULL; 2102 } 2103} 2104 2105static struct cfg_nat * 2106lookup_nat(const int i) 2107{ 2108 struct cfg_nat *ptr; 2109 2110 LIST_FOREACH(ptr, &layer3_chain.nat, _next) 2111 if (ptr->id == i) 2112 return(ptr); 2113 return (NULL); 2114} 2115 2116#define HOOK_NAT(b, p) do { \ 2117 IPFW_WLOCK_ASSERT(&layer3_chain); \ 2118 LIST_INSERT_HEAD(b, p, _next); \ 2119} while (0) 2120 2121#define UNHOOK_NAT(p) do { \ 2122 IPFW_WLOCK_ASSERT(&layer3_chain); \ 2123 LIST_REMOVE(p, _next); \ 2124} while (0) 2125 2126#define HOOK_REDIR(b, p) do { \ 2127 LIST_INSERT_HEAD(b, p, _next); \ 2128} while (0) 2129 2130#define HOOK_SPOOL(b, p) do { \ 2131 LIST_INSERT_HEAD(b, p, _next); \ 2132} while (0) 2133 2134static void 2135del_redir_spool_cfg(struct cfg_nat *n, struct redir_chain *head) 2136{ 2137 struct cfg_redir *r, *tmp_r; 2138 struct cfg_spool *s, *tmp_s; 2139 int i, num; 2140 2141 LIST_FOREACH_SAFE(r, head, _next, tmp_r) { 2142 num = 1; /* Number of alias_link to delete. */ 2143 switch (r->mode) { 2144 case REDIR_PORT: 2145 num = r->pport_cnt; 2146 /* FALLTHROUGH */ 2147 case REDIR_ADDR: 2148 case REDIR_PROTO: 2149 /* Delete all libalias redirect entry. */ 2150 for (i = 0; i < num; i++) 2151 LibAliasRedirectDelete(n->lib, r->alink[i]); 2152 /* Del spool cfg if any. */ 2153 LIST_FOREACH_SAFE(s, &r->spool_chain, _next, tmp_s) { 2154 LIST_REMOVE(s, _next); 2155 free(s, M_IPFW); 2156 } 2157 free(r->alink, M_IPFW); 2158 LIST_REMOVE(r, _next); 2159 free(r, M_IPFW); 2160 break; 2161 default: 2162 printf("unknown redirect mode: %u\n", r->mode); 2163 /* XXX - panic?!?!? */ 2164 break; 2165 } 2166 } 2167} 2168 2169static int 2170add_redir_spool_cfg(char *buf, struct cfg_nat *ptr) 2171{ 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 IPSEC 3147 match = (m_tag_find(m, 3148 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 3149#endif 3150 /* otherwise no match */ 3151 break; 3152 3153#ifdef INET6 3154 case O_IP6_SRC: 3155 match = is_ipv6 && 3156 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 3157 &((ipfw_insn_ip6 *)cmd)->addr6); 3158 break; 3159 3160 case O_IP6_DST: 3161 match = is_ipv6 && 3162 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 3163 &((ipfw_insn_ip6 *)cmd)->addr6); 3164 break; 3165 case O_IP6_SRC_MASK: 3166 case O_IP6_DST_MASK: 3167 if (is_ipv6) { 3168 int i = cmdlen - 1; 3169 struct in6_addr p; 3170 struct in6_addr *d = 3171 &((ipfw_insn_ip6 *)cmd)->addr6; 3172 3173 for (; !match && i > 0; d += 2, 3174 i -= F_INSN_SIZE(struct in6_addr) 3175 * 2) { 3176 p = (cmd->opcode == 3177 O_IP6_SRC_MASK) ? 3178 args->f_id.src_ip6: 3179 args->f_id.dst_ip6; 3180 APPLY_MASK(&p, &d[1]); 3181 match = 3182 IN6_ARE_ADDR_EQUAL(&d[0], 3183 &p); 3184 } 3185 } 3186 break; 3187 3188 case O_IP6_SRC_ME: 3189 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6); 3190 break; 3191 3192 case O_IP6_DST_ME: 3193 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6); 3194 break; 3195 3196 case O_FLOW6ID: 3197 match = is_ipv6 && 3198 flow6id_match(args->f_id.flow_id6, 3199 (ipfw_insn_u32 *) cmd); 3200 break; 3201 3202 case O_EXT_HDR: 3203 match = is_ipv6 && 3204 (ext_hd & ((ipfw_insn *) cmd)->arg1); 3205 break; 3206 3207 case O_IP6: 3208 match = is_ipv6; 3209 break; 3210#endif 3211 3212 case O_IP4: 3213 match = is_ipv4; 3214 break; 3215 3216 case O_TAG: { 3217 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ? 3218 tablearg : cmd->arg1; 3219 3220 /* Packet is already tagged with this tag? */ 3221 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 3222 3223 /* We have `untag' action when F_NOT flag is 3224 * present. And we must remove this mtag from 3225 * mbuf and reset `match' to zero (`match' will 3226 * be inversed later). 3227 * Otherwise we should allocate new mtag and 3228 * push it into mbuf. 3229 */ 3230 if (cmd->len & F_NOT) { /* `untag' action */ 3231 if (mtag != NULL) 3232 m_tag_delete(m, mtag); 3233 } else if (mtag == NULL) { 3234 if ((mtag = m_tag_alloc(MTAG_IPFW, 3235 tag, 0, M_NOWAIT)) != NULL) 3236 m_tag_prepend(m, mtag); 3237 } 3238 match = (cmd->len & F_NOT) ? 0: 1; 3239 break; 3240 } 3241 3242 case O_TAGGED: { 3243 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ? 3244 tablearg : cmd->arg1; 3245 3246 if (cmdlen == 1) { 3247 match = m_tag_locate(m, MTAG_IPFW, 3248 tag, NULL) != NULL; 3249 break; 3250 } 3251 3252 /* we have ranges */ 3253 for (mtag = m_tag_first(m); 3254 mtag != NULL && !match; 3255 mtag = m_tag_next(m, mtag)) { 3256 uint16_t *p; 3257 int i; 3258 3259 if (mtag->m_tag_cookie != MTAG_IPFW) 3260 continue; 3261 3262 p = ((ipfw_insn_u16 *)cmd)->ports; 3263 i = cmdlen - 1; 3264 for(; !match && i > 0; i--, p += 2) 3265 match = 3266 mtag->m_tag_id >= p[0] && 3267 mtag->m_tag_id <= p[1]; 3268 } 3269 break; 3270 } 3271 3272 /* 3273 * The second set of opcodes represents 'actions', 3274 * i.e. the terminal part of a rule once the packet 3275 * matches all previous patterns. 3276 * Typically there is only one action for each rule, 3277 * and the opcode is stored at the end of the rule 3278 * (but there are exceptions -- see below). 3279 * 3280 * In general, here we set retval and terminate the 3281 * outer loop (would be a 'break 3' in some language, 3282 * but we need to do a 'goto done'). 3283 * 3284 * Exceptions: 3285 * O_COUNT and O_SKIPTO actions: 3286 * instead of terminating, we jump to the next rule 3287 * ('goto next_rule', equivalent to a 'break 2'), 3288 * or to the SKIPTO target ('goto again' after 3289 * having set f, cmd and l), respectively. 3290 * 3291 * O_TAG, O_LOG and O_ALTQ action parameters: 3292 * perform some action and set match = 1; 3293 * 3294 * O_LIMIT and O_KEEP_STATE: these opcodes are 3295 * not real 'actions', and are stored right 3296 * before the 'action' part of the rule. 3297 * These opcodes try to install an entry in the 3298 * state tables; if successful, we continue with 3299 * the next opcode (match=1; break;), otherwise 3300 * the packet * must be dropped 3301 * ('goto done' after setting retval); 3302 * 3303 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 3304 * cause a lookup of the state table, and a jump 3305 * to the 'action' part of the parent rule 3306 * ('goto check_body') if an entry is found, or 3307 * (CHECK_STATE only) a jump to the next rule if 3308 * the entry is not found ('goto next_rule'). 3309 * The result of the lookup is cached to make 3310 * further instances of these opcodes are 3311 * effectively NOPs. 3312 */ 3313 case O_LIMIT: 3314 case O_KEEP_STATE: 3315 if (install_state(f, 3316 (ipfw_insn_limit *)cmd, args, tablearg)) { 3317 retval = IP_FW_DENY; 3318 goto done; /* error/limit violation */ 3319 } 3320 match = 1; 3321 break; 3322 3323 case O_PROBE_STATE: 3324 case O_CHECK_STATE: 3325 /* 3326 * dynamic rules are checked at the first 3327 * keep-state or check-state occurrence, 3328 * with the result being stored in dyn_dir. 3329 * The compiler introduces a PROBE_STATE 3330 * instruction for us when we have a 3331 * KEEP_STATE (because PROBE_STATE needs 3332 * to be run first). 3333 */ 3334 if (dyn_dir == MATCH_UNKNOWN && 3335 (q = lookup_dyn_rule(&args->f_id, 3336 &dyn_dir, proto == IPPROTO_TCP ? 3337 TCP(ulp) : NULL)) 3338 != NULL) { 3339 /* 3340 * Found dynamic entry, update stats 3341 * and jump to the 'action' part of 3342 * the parent rule. 3343 */ 3344 q->pcnt++; 3345 q->bcnt += pktlen; 3346 f = q->rule; 3347 cmd = ACTION_PTR(f); 3348 l = f->cmd_len - f->act_ofs; 3349 IPFW_DYN_UNLOCK(); 3350 goto check_body; 3351 } 3352 /* 3353 * Dynamic entry not found. If CHECK_STATE, 3354 * skip to next rule, if PROBE_STATE just 3355 * ignore and continue with next opcode. 3356 */ 3357 if (cmd->opcode == O_CHECK_STATE) 3358 goto next_rule; 3359 match = 1; 3360 break; 3361 3362 case O_ACCEPT: 3363 retval = 0; /* accept */ 3364 goto done; 3365 3366 case O_PIPE: 3367 case O_QUEUE: 3368 args->rule = f; /* report matching rule */ 3369 if (cmd->arg1 == IP_FW_TABLEARG) 3370 args->cookie = tablearg; 3371 else 3372 args->cookie = cmd->arg1; 3373 retval = IP_FW_DUMMYNET; 3374 goto done; 3375 3376 case O_DIVERT: 3377 case O_TEE: { 3378 struct divert_tag *dt; 3379 3380 if (args->eh) /* not on layer 2 */ 3381 break; 3382 mtag = m_tag_get(PACKET_TAG_DIVERT, 3383 sizeof(struct divert_tag), 3384 M_NOWAIT); 3385 if (mtag == NULL) { 3386 /* XXX statistic */ 3387 /* drop packet */ 3388 IPFW_RUNLOCK(chain); 3389 return (IP_FW_DENY); 3390 } 3391 dt = (struct divert_tag *)(mtag+1); 3392 dt->cookie = f->rulenum; 3393 if (cmd->arg1 == IP_FW_TABLEARG) 3394 dt->info = tablearg; 3395 else 3396 dt->info = cmd->arg1; 3397 m_tag_prepend(m, mtag); 3398 retval = (cmd->opcode == O_DIVERT) ? 3399 IP_FW_DIVERT : IP_FW_TEE; 3400 goto done; 3401 } 3402 3403 case O_COUNT: 3404 case O_SKIPTO: 3405 f->pcnt++; /* update stats */ 3406 f->bcnt += pktlen; 3407 f->timestamp = time_uptime; 3408 if (cmd->opcode == O_COUNT) 3409 goto next_rule; 3410 /* handle skipto */ 3411 if (f->next_rule == NULL) 3412 lookup_next_rule(f); 3413 f = f->next_rule; 3414 goto again; 3415 3416 case O_REJECT: 3417 /* 3418 * Drop the packet and send a reject notice 3419 * if the packet is not ICMP (or is an ICMP 3420 * query), and it is not multicast/broadcast. 3421 */ 3422 if (hlen > 0 && is_ipv4 && offset == 0 && 3423 (proto != IPPROTO_ICMP || 3424 is_icmp_query(ICMP(ulp))) && 3425 !(m->m_flags & (M_BCAST|M_MCAST)) && 3426 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 3427 send_reject(args, cmd->arg1, ip_len, ip); 3428 m = args->m; 3429 } 3430 /* FALLTHROUGH */ 3431#ifdef INET6 3432 case O_UNREACH6: 3433 if (hlen > 0 && is_ipv6 && 3434 ((offset & IP6F_OFF_MASK) == 0) && 3435 (proto != IPPROTO_ICMPV6 || 3436 (is_icmp6_query(args->f_id.flags) == 1)) && 3437 !(m->m_flags & (M_BCAST|M_MCAST)) && 3438 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 3439 send_reject6( 3440 args, cmd->arg1, hlen, 3441 (struct ip6_hdr *)ip); 3442 m = args->m; 3443 } 3444 /* FALLTHROUGH */ 3445#endif 3446 case O_DENY: 3447 retval = IP_FW_DENY; 3448 goto done; 3449 3450 case O_FORWARD_IP: { 3451 struct sockaddr_in *sa; 3452 sa = &(((ipfw_insn_sa *)cmd)->sa); 3453 if (args->eh) /* not valid on layer2 pkts */ 3454 break; 3455 if (!q || dyn_dir == MATCH_FORWARD) { 3456 if (sa->sin_addr.s_addr == INADDR_ANY) { 3457 bcopy(sa, &args->hopstore, 3458 sizeof(*sa)); 3459 args->hopstore.sin_addr.s_addr = 3460 htonl(tablearg); 3461 args->next_hop = 3462 &args->hopstore; 3463 } else { 3464 args->next_hop = sa; 3465 } 3466 } 3467 retval = IP_FW_PASS; 3468 } 3469 goto done; 3470 3471 case O_NETGRAPH: 3472 case O_NGTEE: 3473 args->rule = f; /* report matching rule */ 3474 if (cmd->arg1 == IP_FW_TABLEARG) 3475 args->cookie = tablearg; 3476 else 3477 args->cookie = cmd->arg1; 3478 retval = (cmd->opcode == O_NETGRAPH) ? 3479 IP_FW_NETGRAPH : IP_FW_NGTEE; 3480 goto done; 3481 3482#ifdef IPFIREWALL_NAT 3483 case O_NAT: { 3484 struct cfg_nat *t; 3485 struct mbuf *mcl; 3486 /* XXX - libalias duct tape */ 3487 int ldt; 3488 char *c; 3489 3490 ldt = 0; 3491 args->rule = f; /* Report matching rule. */ 3492 retval = 0; 3493 t = ((ipfw_insn_nat *)cmd)->nat; 3494 if (t == NULL) { 3495 t = lookup_nat(cmd->arg1); 3496 if (t == NULL) { 3497 retval = IP_FW_DENY; 3498 goto done; 3499 } else 3500 ((ipfw_insn_nat *)cmd)->nat = 3501 t; 3502 } 3503 if ((mcl = m_megapullup(m, m->m_pkthdr.len)) == 3504 NULL) 3505 goto badnat; 3506 ip = mtod(mcl, struct ip *); 3507 if (args->eh == NULL) { 3508 ip->ip_len = htons(ip->ip_len); 3509 ip->ip_off = htons(ip->ip_off); 3510 } 3511 3512 /* 3513 * XXX - Libalias checksum offload 'duct tape': 3514 * 3515 * locally generated packets have only 3516 * pseudo-header checksum calculated 3517 * and libalias will screw it[1], so 3518 * mark them for later fix. Moreover 3519 * there are cases when libalias 3520 * modify tcp packet data[2], mark it 3521 * for later fix too. 3522 * 3523 * [1] libalias was never meant to run 3524 * in kernel, so it doesn't have any 3525 * knowledge about checksum 3526 * offloading, and it expects a packet 3527 * with a full internet 3528 * checksum. Unfortunately, packets 3529 * generated locally will have just the 3530 * pseudo header calculated, and when 3531 * libalias tries to adjust the 3532 * checksum it will actually screw it. 3533 * 3534 * [2] when libalias modify tcp's data 3535 * content, full TCP checksum has to 3536 * be recomputed: the problem is that 3537 * libalias doesn't have any idea 3538 * about checksum offloading To 3539 * workaround this, we do not do 3540 * checksumming in LibAlias, but only 3541 * mark the packets in th_x2 field. If 3542 * we receive a marked packet, we 3543 * calculate correct checksum for it 3544 * aware of offloading. Why such a 3545 * terrible hack instead of 3546 * recalculating checksum for each 3547 * packet? Because the previous 3548 * checksum was not checked! 3549 * Recalculating checksums for EVERY 3550 * packet will hide ALL transmission 3551 * errors. Yes, marked packets still 3552 * suffer from this problem. But, 3553 * sigh, natd(8) has this problem, 3554 * too. 3555 * 3556 * TODO: -make libalias mbuf aware (so 3557 * it can handle delayed checksum and tso) 3558 */ 3559 3560 if (mcl->m_pkthdr.rcvif == NULL && 3561 mcl->m_pkthdr.csum_flags & 3562 CSUM_DELAY_DATA) 3563 ldt = 1; 3564 3565 c = mtod(mcl, char *); 3566 if (oif == NULL) 3567 retval = LibAliasIn(t->lib, c, 3568 MCLBYTES); 3569 else 3570 retval = LibAliasOut(t->lib, c, 3571 MCLBYTES); 3572 if (retval != PKT_ALIAS_OK) { 3573 /* XXX - should i add some logging? */ 3574 m_free(mcl); 3575 badnat: 3576 args->m = NULL; 3577 retval = IP_FW_DENY; 3578 goto done; 3579 } 3580 mcl->m_pkthdr.len = mcl->m_len = 3581 ntohs(ip->ip_len); 3582 3583 /* 3584 * XXX - libalias checksum offload 3585 * 'duct tape' (see above) 3586 */ 3587 3588 if ((ip->ip_off & htons(IP_OFFMASK)) == 0 && 3589 ip->ip_p == IPPROTO_TCP) { 3590 struct tcphdr *th; 3591 3592 th = (struct tcphdr *)(ip + 1); 3593 if (th->th_x2) 3594 ldt = 1; 3595 } 3596 3597 if (ldt) { 3598 struct tcphdr *th; 3599 struct udphdr *uh; 3600 u_short cksum; 3601 3602 ip->ip_len = ntohs(ip->ip_len); 3603 cksum = in_pseudo( 3604 ip->ip_src.s_addr, 3605 ip->ip_dst.s_addr, 3606 htons(ip->ip_p + ip->ip_len - 3607 (ip->ip_hl << 2)) 3608 ); 3609 3610 switch (ip->ip_p) { 3611 case IPPROTO_TCP: 3612 th = (struct tcphdr *)(ip + 1); 3613 /* 3614 * Maybe it was set in 3615 * libalias... 3616 */ 3617 th->th_x2 = 0; 3618 th->th_sum = cksum; 3619 mcl->m_pkthdr.csum_data = 3620 offsetof(struct tcphdr, 3621 th_sum); 3622 break; 3623 case IPPROTO_UDP: 3624 uh = (struct udphdr *)(ip + 1); 3625 uh->uh_sum = cksum; 3626 mcl->m_pkthdr.csum_data = 3627 offsetof(struct udphdr, 3628 uh_sum); 3629 break; 3630 } 3631 /* 3632 * No hw checksum offloading: do it 3633 * by ourself. 3634 */ 3635 if ((mcl->m_pkthdr.csum_flags & 3636 CSUM_DELAY_DATA) == 0) { 3637 in_delayed_cksum(mcl); 3638 mcl->m_pkthdr.csum_flags &= 3639 ~CSUM_DELAY_DATA; 3640 } 3641 ip->ip_len = htons(ip->ip_len); 3642 } 3643 3644 if (args->eh == NULL) { 3645 ip->ip_len = ntohs(ip->ip_len); 3646 ip->ip_off = ntohs(ip->ip_off); 3647 } 3648 3649 args->m = mcl; 3650 retval = IP_FW_NAT; 3651 goto done; 3652 } 3653#endif 3654 3655 default: 3656 panic("-- unknown opcode %d\n", cmd->opcode); 3657 } /* end of switch() on opcodes */ 3658 3659 if (cmd->len & F_NOT) 3660 match = !match; 3661 3662 if (match) { 3663 if (cmd->len & F_OR) 3664 skip_or = 1; 3665 } else { 3666 if (!(cmd->len & F_OR)) /* not an OR block, */ 3667 break; /* try next rule */ 3668 } 3669 3670 } /* end of inner for, scan opcodes */ 3671 3672next_rule:; /* try next rule */ 3673 3674 } /* end of outer for, scan rules */ 3675 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 3676 IPFW_RUNLOCK(chain); 3677 return (IP_FW_DENY); 3678 3679done: 3680 /* Update statistics */ 3681 f->pcnt++; 3682 f->bcnt += pktlen; 3683 f->timestamp = time_uptime; 3684 IPFW_RUNLOCK(chain); 3685 return (retval); 3686 3687pullup_failed: 3688 if (fw_verbose) 3689 printf("ipfw: pullup failed\n"); 3690 return (IP_FW_DENY); 3691} 3692 3693/* 3694 * When a rule is added/deleted, clear the next_rule pointers in all rules. 3695 * These will be reconstructed on the fly as packets are matched. 3696 */ 3697static void 3698flush_rule_ptrs(struct ip_fw_chain *chain) 3699{ 3700 struct ip_fw *rule; 3701 3702 IPFW_WLOCK_ASSERT(chain); 3703 3704 for (rule = chain->rules; rule; rule = rule->next) 3705 rule->next_rule = NULL; 3706} 3707 3708/* 3709 * Add a new rule to the list. Copy the rule into a malloc'ed area, then 3710 * possibly create a rule number and add the rule to the list. 3711 * Update the rule_number in the input struct so the caller knows it as well. 3712 */ 3713static int 3714add_rule(struct ip_fw_chain *chain, struct ip_fw *input_rule) 3715{ 3716 struct ip_fw *rule, *f, *prev; 3717 int l = RULESIZE(input_rule); 3718 3719 if (chain->rules == NULL && input_rule->rulenum != IPFW_DEFAULT_RULE) 3720 return (EINVAL); 3721 3722 rule = malloc(l, M_IPFW, M_NOWAIT | M_ZERO); 3723 if (rule == NULL) 3724 return (ENOSPC); 3725 3726 bcopy(input_rule, rule, l); 3727 3728 rule->next = NULL; 3729 rule->next_rule = NULL; 3730 3731 rule->pcnt = 0; 3732 rule->bcnt = 0; 3733 rule->timestamp = 0; 3734 3735 IPFW_WLOCK(chain); 3736 3737 if (chain->rules == NULL) { /* default rule */ 3738 chain->rules = rule; 3739 goto done; 3740 } 3741 3742 /* 3743 * If rulenum is 0, find highest numbered rule before the 3744 * default rule, and add autoinc_step 3745 */ 3746 if (autoinc_step < 1) 3747 autoinc_step = 1; 3748 else if (autoinc_step > 1000) 3749 autoinc_step = 1000; 3750 if (rule->rulenum == 0) { 3751 /* 3752 * locate the highest numbered rule before default 3753 */ 3754 for (f = chain->rules; f; f = f->next) { 3755 if (f->rulenum == IPFW_DEFAULT_RULE) 3756 break; 3757 rule->rulenum = f->rulenum; 3758 } 3759 if (rule->rulenum < IPFW_DEFAULT_RULE - autoinc_step) 3760 rule->rulenum += autoinc_step; 3761 input_rule->rulenum = rule->rulenum; 3762 } 3763 3764 /* 3765 * Now insert the new rule in the right place in the sorted list. 3766 */ 3767 for (prev = NULL, f = chain->rules; f; prev = f, f = f->next) { 3768 if (f->rulenum > rule->rulenum) { /* found the location */ 3769 if (prev) { 3770 rule->next = f; 3771 prev->next = rule; 3772 } else { /* head insert */ 3773 rule->next = chain->rules; 3774 chain->rules = rule; 3775 } 3776 break; 3777 } 3778 } 3779 flush_rule_ptrs(chain); 3780done: 3781 static_count++; 3782 static_len += l; 3783 IPFW_WUNLOCK(chain); 3784 DEB(printf("ipfw: installed rule %d, static count now %d\n", 3785 rule->rulenum, static_count);) 3786 return (0); 3787} 3788 3789/** 3790 * Remove a static rule (including derived * dynamic rules) 3791 * and place it on the ``reap list'' for later reclamation. 3792 * The caller is in charge of clearing rule pointers to avoid 3793 * dangling pointers. 3794 * @return a pointer to the next entry. 3795 * Arguments are not checked, so they better be correct. 3796 */ 3797static struct ip_fw * 3798remove_rule(struct ip_fw_chain *chain, struct ip_fw *rule, 3799 struct ip_fw *prev) 3800{ 3801 struct ip_fw *n; 3802 int l = RULESIZE(rule); 3803 3804 IPFW_WLOCK_ASSERT(chain); 3805 3806 n = rule->next; 3807 IPFW_DYN_LOCK(); 3808 remove_dyn_rule(rule, NULL /* force removal */); 3809 IPFW_DYN_UNLOCK(); 3810 if (prev == NULL) 3811 chain->rules = n; 3812 else 3813 prev->next = n; 3814 static_count--; 3815 static_len -= l; 3816 3817 rule->next = chain->reap; 3818 chain->reap = rule; 3819 3820 return n; 3821} 3822 3823/** 3824 * Reclaim storage associated with a list of rules. This is 3825 * typically the list created using remove_rule. 3826 */ 3827static void 3828reap_rules(struct ip_fw *head) 3829{ 3830 struct ip_fw *rule; 3831 3832 while ((rule = head) != NULL) { 3833 head = head->next; 3834 if (DUMMYNET_LOADED) 3835 ip_dn_ruledel_ptr(rule); 3836 free(rule, M_IPFW); 3837 } 3838} 3839 3840/* 3841 * Remove all rules from a chain (except rules in set RESVD_SET 3842 * unless kill_default = 1). The caller is responsible for 3843 * reclaiming storage for the rules left in chain->reap. 3844 */ 3845static void 3846free_chain(struct ip_fw_chain *chain, int kill_default) 3847{ 3848 struct ip_fw *prev, *rule; 3849 3850 IPFW_WLOCK_ASSERT(chain); 3851 3852 flush_rule_ptrs(chain); /* more efficient to do outside the loop */ 3853 for (prev = NULL, rule = chain->rules; rule ; ) 3854 if (kill_default || rule->set != RESVD_SET) 3855 rule = remove_rule(chain, rule, prev); 3856 else { 3857 prev = rule; 3858 rule = rule->next; 3859 } 3860} 3861 3862/** 3863 * Remove all rules with given number, and also do set manipulation. 3864 * Assumes chain != NULL && *chain != NULL. 3865 * 3866 * The argument is an u_int32_t. The low 16 bit are the rule or set number, 3867 * the next 8 bits are the new set, the top 8 bits are the command: 3868 * 3869 * 0 delete rules with given number 3870 * 1 delete rules with given set number 3871 * 2 move rules with given number to new set 3872 * 3 move rules with given set number to new set 3873 * 4 swap sets with given numbers 3874 * 5 delete rules with given number and with given set number 3875 */ 3876static int 3877del_entry(struct ip_fw_chain *chain, u_int32_t arg) 3878{ 3879 struct ip_fw *prev = NULL, *rule; 3880 u_int16_t rulenum; /* rule or old_set */ 3881 u_int8_t cmd, new_set; 3882 3883 rulenum = arg & 0xffff; 3884 cmd = (arg >> 24) & 0xff; 3885 new_set = (arg >> 16) & 0xff; 3886 3887 if (cmd > 5 || new_set > RESVD_SET) 3888 return EINVAL; 3889 if (cmd == 0 || cmd == 2 || cmd == 5) { 3890 if (rulenum >= IPFW_DEFAULT_RULE) 3891 return EINVAL; 3892 } else { 3893 if (rulenum > RESVD_SET) /* old_set */ 3894 return EINVAL; 3895 } 3896 3897 IPFW_WLOCK(chain); 3898 rule = chain->rules; 3899 chain->reap = NULL; 3900 switch (cmd) { 3901 case 0: /* delete rules with given number */ 3902 /* 3903 * locate first rule to delete 3904 */ 3905 for (; rule->rulenum < rulenum; prev = rule, rule = rule->next) 3906 ; 3907 if (rule->rulenum != rulenum) { 3908 IPFW_WUNLOCK(chain); 3909 return EINVAL; 3910 } 3911 3912 /* 3913 * flush pointers outside the loop, then delete all matching 3914 * rules. prev remains the same throughout the cycle. 3915 */ 3916 flush_rule_ptrs(chain); 3917 while (rule->rulenum == rulenum) 3918 rule = remove_rule(chain, rule, prev); 3919 break; 3920 3921 case 1: /* delete all rules with given set number */ 3922 flush_rule_ptrs(chain); 3923 rule = chain->rules; 3924 while (rule->rulenum < IPFW_DEFAULT_RULE) 3925 if (rule->set == rulenum) 3926 rule = remove_rule(chain, rule, prev); 3927 else { 3928 prev = rule; 3929 rule = rule->next; 3930 } 3931 break; 3932 3933 case 2: /* move rules with given number to new set */ 3934 rule = chain->rules; 3935 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3936 if (rule->rulenum == rulenum) 3937 rule->set = new_set; 3938 break; 3939 3940 case 3: /* move rules with given set number to new set */ 3941 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3942 if (rule->set == rulenum) 3943 rule->set = new_set; 3944 break; 3945 3946 case 4: /* swap two sets */ 3947 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3948 if (rule->set == rulenum) 3949 rule->set = new_set; 3950 else if (rule->set == new_set) 3951 rule->set = rulenum; 3952 break; 3953 case 5: /* delete rules with given number and with given set number. 3954 * rulenum - given rule number; 3955 * new_set - given set number. 3956 */ 3957 for (; rule->rulenum < rulenum; prev = rule, rule = rule->next) 3958 ; 3959 if (rule->rulenum != rulenum) { 3960 IPFW_WUNLOCK(chain); 3961 return (EINVAL); 3962 } 3963 flush_rule_ptrs(chain); 3964 while (rule->rulenum == rulenum) { 3965 if (rule->set == new_set) 3966 rule = remove_rule(chain, rule, prev); 3967 else { 3968 prev = rule; 3969 rule = rule->next; 3970 } 3971 } 3972 } 3973 /* 3974 * Look for rules to reclaim. We grab the list before 3975 * releasing the lock then reclaim them w/o the lock to 3976 * avoid a LOR with dummynet. 3977 */ 3978 rule = chain->reap; 3979 chain->reap = NULL; 3980 IPFW_WUNLOCK(chain); 3981 if (rule) 3982 reap_rules(rule); 3983 return 0; 3984} 3985 3986/* 3987 * Clear counters for a specific rule. 3988 * The enclosing "table" is assumed locked. 3989 */ 3990static void 3991clear_counters(struct ip_fw *rule, int log_only) 3992{ 3993 ipfw_insn_log *l = (ipfw_insn_log *)ACTION_PTR(rule); 3994 3995 if (log_only == 0) { 3996 rule->bcnt = rule->pcnt = 0; 3997 rule->timestamp = 0; 3998 } 3999 if (l->o.opcode == O_LOG) 4000 l->log_left = l->max_log; 4001} 4002 4003/** 4004 * Reset some or all counters on firewall rules. 4005 * The argument `arg' is an u_int32_t. The low 16 bit are the rule number, 4006 * the next 8 bits are the set number, the top 8 bits are the command: 4007 * 0 work with rules from all set's; 4008 * 1 work with rules only from specified set. 4009 * Specified rule number is zero if we want to clear all entries. 4010 * log_only is 1 if we only want to reset logs, zero otherwise. 4011 */ 4012static int 4013zero_entry(struct ip_fw_chain *chain, u_int32_t arg, int log_only) 4014{ 4015 struct ip_fw *rule; 4016 char *msg; 4017 4018 uint16_t rulenum = arg & 0xffff; 4019 uint8_t set = (arg >> 16) & 0xff; 4020 uint8_t cmd = (arg >> 24) & 0xff; 4021 4022 if (cmd > 1) 4023 return (EINVAL); 4024 if (cmd == 1 && set > RESVD_SET) 4025 return (EINVAL); 4026 4027 IPFW_WLOCK(chain); 4028 if (rulenum == 0) { 4029 norule_counter = 0; 4030 for (rule = chain->rules; rule; rule = rule->next) { 4031 /* Skip rules from another set. */ 4032 if (cmd == 1 && rule->set != set) 4033 continue; 4034 clear_counters(rule, log_only); 4035 } 4036 msg = log_only ? "ipfw: All logging counts reset.\n" : 4037 "ipfw: Accounting cleared.\n"; 4038 } else { 4039 int cleared = 0; 4040 /* 4041 * We can have multiple rules with the same number, so we 4042 * need to clear them all. 4043 */ 4044 for (rule = chain->rules; rule; rule = rule->next) 4045 if (rule->rulenum == rulenum) { 4046 while (rule && rule->rulenum == rulenum) { 4047 if (cmd == 0 || rule->set == set) 4048 clear_counters(rule, log_only); 4049 rule = rule->next; 4050 } 4051 cleared = 1; 4052 break; 4053 } 4054 if (!cleared) { /* we did not find any matching rules */ 4055 IPFW_WUNLOCK(chain); 4056 return (EINVAL); 4057 } 4058 msg = log_only ? "ipfw: Entry %d logging count reset.\n" : 4059 "ipfw: Entry %d cleared.\n"; 4060 } 4061 IPFW_WUNLOCK(chain); 4062 4063 if (fw_verbose) 4064 log(LOG_SECURITY | LOG_NOTICE, msg, rulenum); 4065 return (0); 4066} 4067 4068/* 4069 * Check validity of the structure before insert. 4070 * Fortunately rules are simple, so this mostly need to check rule sizes. 4071 */ 4072static int 4073check_ipfw_struct(struct ip_fw *rule, int size) 4074{ 4075 int l, cmdlen = 0; 4076 int have_action=0; 4077 ipfw_insn *cmd; 4078 4079 if (size < sizeof(*rule)) { 4080 printf("ipfw: rule too short\n"); 4081 return (EINVAL); 4082 } 4083 /* first, check for valid size */ 4084 l = RULESIZE(rule); 4085 if (l != size) { 4086 printf("ipfw: size mismatch (have %d want %d)\n", size, l); 4087 return (EINVAL); 4088 } 4089 if (rule->act_ofs >= rule->cmd_len) { 4090 printf("ipfw: bogus action offset (%u > %u)\n", 4091 rule->act_ofs, rule->cmd_len - 1); 4092 return (EINVAL); 4093 } 4094 /* 4095 * Now go for the individual checks. Very simple ones, basically only 4096 * instruction sizes. 4097 */ 4098 for (l = rule->cmd_len, cmd = rule->cmd ; 4099 l > 0 ; l -= cmdlen, cmd += cmdlen) { 4100 cmdlen = F_LEN(cmd); 4101 if (cmdlen > l) { 4102 printf("ipfw: opcode %d size truncated\n", 4103 cmd->opcode); 4104 return EINVAL; 4105 } 4106 DEB(printf("ipfw: opcode %d\n", cmd->opcode);) 4107 switch (cmd->opcode) { 4108 case O_PROBE_STATE: 4109 case O_KEEP_STATE: 4110 case O_PROTO: 4111 case O_IP_SRC_ME: 4112 case O_IP_DST_ME: 4113 case O_LAYER2: 4114 case O_IN: 4115 case O_FRAG: 4116 case O_DIVERTED: 4117 case O_IPOPT: 4118 case O_IPTOS: 4119 case O_IPPRECEDENCE: 4120 case O_IPVER: 4121 case O_TCPWIN: 4122 case O_TCPFLAGS: 4123 case O_TCPOPTS: 4124 case O_ESTAB: 4125 case O_VERREVPATH: 4126 case O_VERSRCREACH: 4127 case O_ANTISPOOF: 4128 case O_IPSEC: 4129#ifdef INET6 4130 case O_IP6_SRC_ME: 4131 case O_IP6_DST_ME: 4132 case O_EXT_HDR: 4133 case O_IP6: 4134#endif 4135 case O_IP4: 4136 case O_TAG: 4137 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 4138 goto bad_size; 4139 break; 4140 4141 case O_UID: 4142 case O_GID: 4143 case O_JAIL: 4144 case O_IP_SRC: 4145 case O_IP_DST: 4146 case O_TCPSEQ: 4147 case O_TCPACK: 4148 case O_PROB: 4149 case O_ICMPTYPE: 4150 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32)) 4151 goto bad_size; 4152 break; 4153 4154 case O_LIMIT: 4155 if (cmdlen != F_INSN_SIZE(ipfw_insn_limit)) 4156 goto bad_size; 4157 break; 4158 4159 case O_LOG: 4160 if (cmdlen != F_INSN_SIZE(ipfw_insn_log)) 4161 goto bad_size; 4162 4163 ((ipfw_insn_log *)cmd)->log_left = 4164 ((ipfw_insn_log *)cmd)->max_log; 4165 4166 break; 4167 4168 case O_IP_SRC_MASK: 4169 case O_IP_DST_MASK: 4170 /* only odd command lengths */ 4171 if ( !(cmdlen & 1) || cmdlen > 31) 4172 goto bad_size; 4173 break; 4174 4175 case O_IP_SRC_SET: 4176 case O_IP_DST_SET: 4177 if (cmd->arg1 == 0 || cmd->arg1 > 256) { 4178 printf("ipfw: invalid set size %d\n", 4179 cmd->arg1); 4180 return EINVAL; 4181 } 4182 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) + 4183 (cmd->arg1+31)/32 ) 4184 goto bad_size; 4185 break; 4186 4187 case O_IP_SRC_LOOKUP: 4188 case O_IP_DST_LOOKUP: 4189 if (cmd->arg1 >= IPFW_TABLES_MAX) { 4190 printf("ipfw: invalid table number %d\n", 4191 cmd->arg1); 4192 return (EINVAL); 4193 } 4194 if (cmdlen != F_INSN_SIZE(ipfw_insn) && 4195 cmdlen != F_INSN_SIZE(ipfw_insn_u32)) 4196 goto bad_size; 4197 break; 4198 4199 case O_MACADDR2: 4200 if (cmdlen != F_INSN_SIZE(ipfw_insn_mac)) 4201 goto bad_size; 4202 break; 4203 4204 case O_NOP: 4205 case O_IPID: 4206 case O_IPTTL: 4207 case O_IPLEN: 4208 case O_TCPDATALEN: 4209 case O_TAGGED: 4210 if (cmdlen < 1 || cmdlen > 31) 4211 goto bad_size; 4212 break; 4213 4214 case O_MAC_TYPE: 4215 case O_IP_SRCPORT: 4216 case O_IP_DSTPORT: /* XXX artificial limit, 30 port pairs */ 4217 if (cmdlen < 2 || cmdlen > 31) 4218 goto bad_size; 4219 break; 4220 4221 case O_RECV: 4222 case O_XMIT: 4223 case O_VIA: 4224 if (cmdlen != F_INSN_SIZE(ipfw_insn_if)) 4225 goto bad_size; 4226 break; 4227 4228 case O_ALTQ: 4229 if (cmdlen != F_INSN_SIZE(ipfw_insn_altq)) 4230 goto bad_size; 4231 break; 4232 4233 case O_PIPE: 4234 case O_QUEUE: 4235 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 4236 goto bad_size; 4237 goto check_action; 4238 4239 case O_FORWARD_IP: 4240#ifdef IPFIREWALL_FORWARD 4241 if (cmdlen != F_INSN_SIZE(ipfw_insn_sa)) 4242 goto bad_size; 4243 goto check_action; 4244#else 4245 return EINVAL; 4246#endif 4247 4248 case O_DIVERT: 4249 case O_TEE: 4250 if (ip_divert_ptr == NULL) 4251 return EINVAL; 4252 else 4253 goto check_size; 4254 case O_NETGRAPH: 4255 case O_NGTEE: 4256 if (!NG_IPFW_LOADED) 4257 return EINVAL; 4258 else 4259 goto check_size; 4260 case O_NAT: 4261#ifdef IPFIREWALL_NAT 4262 if (cmdlen != F_INSN_SIZE(ipfw_insn_nat)) 4263 goto bad_size; 4264 goto check_action; 4265#else 4266 return EINVAL; 4267#endif 4268 case O_FORWARD_MAC: /* XXX not implemented yet */ 4269 case O_CHECK_STATE: 4270 case O_COUNT: 4271 case O_ACCEPT: 4272 case O_DENY: 4273 case O_REJECT: 4274#ifdef INET6 4275 case O_UNREACH6: 4276#endif 4277 case O_SKIPTO: 4278check_size: 4279 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 4280 goto bad_size; 4281check_action: 4282 if (have_action) { 4283 printf("ipfw: opcode %d, multiple actions" 4284 " not allowed\n", 4285 cmd->opcode); 4286 return EINVAL; 4287 } 4288 have_action = 1; 4289 if (l != cmdlen) { 4290 printf("ipfw: opcode %d, action must be" 4291 " last opcode\n", 4292 cmd->opcode); 4293 return EINVAL; 4294 } 4295 break; 4296#ifdef INET6 4297 case O_IP6_SRC: 4298 case O_IP6_DST: 4299 if (cmdlen != F_INSN_SIZE(struct in6_addr) + 4300 F_INSN_SIZE(ipfw_insn)) 4301 goto bad_size; 4302 break; 4303 4304 case O_FLOW6ID: 4305 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) + 4306 ((ipfw_insn_u32 *)cmd)->o.arg1) 4307 goto bad_size; 4308 break; 4309 4310 case O_IP6_SRC_MASK: 4311 case O_IP6_DST_MASK: 4312 if ( !(cmdlen & 1) || cmdlen > 127) 4313 goto bad_size; 4314 break; 4315 case O_ICMP6TYPE: 4316 if( cmdlen != F_INSN_SIZE( ipfw_insn_icmp6 ) ) 4317 goto bad_size; 4318 break; 4319#endif 4320 4321 default: 4322 switch (cmd->opcode) { 4323#ifndef INET6 4324 case O_IP6_SRC_ME: 4325 case O_IP6_DST_ME: 4326 case O_EXT_HDR: 4327 case O_IP6: 4328 case O_UNREACH6: 4329 case O_IP6_SRC: 4330 case O_IP6_DST: 4331 case O_FLOW6ID: 4332 case O_IP6_SRC_MASK: 4333 case O_IP6_DST_MASK: 4334 case O_ICMP6TYPE: 4335 printf("ipfw: no IPv6 support in kernel\n"); 4336 return EPROTONOSUPPORT; 4337#endif 4338 default: 4339 printf("ipfw: opcode %d, unknown opcode\n", 4340 cmd->opcode); 4341 return EINVAL; 4342 } 4343 } 4344 } 4345 if (have_action == 0) { 4346 printf("ipfw: missing action\n"); 4347 return EINVAL; 4348 } 4349 return 0; 4350 4351bad_size: 4352 printf("ipfw: opcode %d size %d wrong\n", 4353 cmd->opcode, cmdlen); 4354 return EINVAL; 4355} 4356 4357/* 4358 * Copy the static and dynamic rules to the supplied buffer 4359 * and return the amount of space actually used. 4360 */ 4361static size_t 4362ipfw_getrules(struct ip_fw_chain *chain, void *buf, size_t space) 4363{ 4364 char *bp = buf; 4365 char *ep = bp + space; 4366 struct ip_fw *rule; 4367 int i; 4368 time_t boot_seconds; 4369 4370 boot_seconds = boottime.tv_sec; 4371 /* XXX this can take a long time and locking will block packet flow */ 4372 IPFW_RLOCK(chain); 4373 for (rule = chain->rules; rule ; rule = rule->next) { 4374 /* 4375 * Verify the entry fits in the buffer in case the 4376 * rules changed between calculating buffer space and 4377 * now. This would be better done using a generation 4378 * number but should suffice for now. 4379 */ 4380 i = RULESIZE(rule); 4381 if (bp + i <= ep) { 4382 bcopy(rule, bp, i); 4383 /* 4384 * XXX HACK. Store the disable mask in the "next" pointer 4385 * in a wild attempt to keep the ABI the same. 4386 * Why do we do this on EVERY rule? 4387 */ 4388 bcopy(&set_disable, &(((struct ip_fw *)bp)->next_rule), 4389 sizeof(set_disable)); 4390 if (((struct ip_fw *)bp)->timestamp) 4391 ((struct ip_fw *)bp)->timestamp += boot_seconds; 4392 bp += i; 4393 } 4394 } 4395 IPFW_RUNLOCK(chain); 4396 if (ipfw_dyn_v) { 4397 ipfw_dyn_rule *p, *last = NULL; 4398 4399 IPFW_DYN_LOCK(); 4400 for (i = 0 ; i < curr_dyn_buckets; i++) 4401 for (p = ipfw_dyn_v[i] ; p != NULL; p = p->next) { 4402 if (bp + sizeof *p <= ep) { 4403 ipfw_dyn_rule *dst = 4404 (ipfw_dyn_rule *)bp; 4405 bcopy(p, dst, sizeof *p); 4406 bcopy(&(p->rule->rulenum), &(dst->rule), 4407 sizeof(p->rule->rulenum)); 4408 /* 4409 * store set number into high word of 4410 * dst->rule pointer. 4411 */ 4412 bcopy(&(p->rule->set), &dst->rule + 4413 sizeof(p->rule->rulenum), 4414 sizeof(p->rule->set)); 4415 /* 4416 * store a non-null value in "next". 4417 * The userland code will interpret a 4418 * NULL here as a marker 4419 * for the last dynamic rule. 4420 */ 4421 bcopy(&dst, &dst->next, sizeof(dst)); 4422 last = dst; 4423 dst->expire = 4424 TIME_LEQ(dst->expire, time_uptime) ? 4425 0 : dst->expire - time_uptime ; 4426 bp += sizeof(ipfw_dyn_rule); 4427 } 4428 } 4429 IPFW_DYN_UNLOCK(); 4430 if (last != NULL) /* mark last dynamic rule */ 4431 bzero(&last->next, sizeof(last)); 4432 } 4433 return (bp - (char *)buf); 4434} 4435 4436 4437/** 4438 * {set|get}sockopt parser. 4439 */ 4440static int 4441ipfw_ctl(struct sockopt *sopt) 4442{ 4443#define RULE_MAXSIZE (256*sizeof(u_int32_t)) 4444 int error; 4445 size_t size; 4446 struct ip_fw *buf, *rule; 4447 u_int32_t rulenum[2]; 4448 4449 error = priv_check(sopt->sopt_td, PRIV_NETINET_IPFW); 4450 if (error) 4451 return (error); 4452 4453 /* 4454 * Disallow modifications in really-really secure mode, but still allow 4455 * the logging counters to be reset. 4456 */ 4457 if (sopt->sopt_name == IP_FW_ADD || 4458 (sopt->sopt_dir == SOPT_SET && sopt->sopt_name != IP_FW_RESETLOG)) { 4459 error = securelevel_ge(sopt->sopt_td->td_ucred, 3); 4460 if (error) 4461 return (error); 4462 } 4463 4464 error = 0; 4465 4466 switch (sopt->sopt_name) { 4467 case IP_FW_GET: 4468 /* 4469 * pass up a copy of the current rules. Static rules 4470 * come first (the last of which has number IPFW_DEFAULT_RULE), 4471 * followed by a possibly empty list of dynamic rule. 4472 * The last dynamic rule has NULL in the "next" field. 4473 * 4474 * Note that the calculated size is used to bound the 4475 * amount of data returned to the user. The rule set may 4476 * change between calculating the size and returning the 4477 * data in which case we'll just return what fits. 4478 */ 4479 size = static_len; /* size of static rules */ 4480 if (ipfw_dyn_v) /* add size of dyn.rules */ 4481 size += (dyn_count * sizeof(ipfw_dyn_rule)); 4482 4483 /* 4484 * XXX todo: if the user passes a short length just to know 4485 * how much room is needed, do not bother filling up the 4486 * buffer, just jump to the sooptcopyout. 4487 */ 4488 buf = malloc(size, M_TEMP, M_WAITOK); 4489 error = sooptcopyout(sopt, buf, 4490 ipfw_getrules(&layer3_chain, buf, size)); 4491 free(buf, M_TEMP); 4492 break; 4493 4494 case IP_FW_FLUSH: 4495 /* 4496 * Normally we cannot release the lock on each iteration. 4497 * We could do it here only because we start from the head all 4498 * the times so there is no risk of missing some entries. 4499 * On the other hand, the risk is that we end up with 4500 * a very inconsistent ruleset, so better keep the lock 4501 * around the whole cycle. 4502 * 4503 * XXX this code can be improved by resetting the head of 4504 * the list to point to the default rule, and then freeing 4505 * the old list without the need for a lock. 4506 */ 4507 4508 IPFW_WLOCK(&layer3_chain); 4509 layer3_chain.reap = NULL; 4510 free_chain(&layer3_chain, 0 /* keep default rule */); 4511 rule = layer3_chain.reap; 4512 layer3_chain.reap = NULL; 4513 IPFW_WUNLOCK(&layer3_chain); 4514 if (rule != NULL) 4515 reap_rules(rule); 4516 break; 4517 4518 case IP_FW_ADD: 4519 rule = malloc(RULE_MAXSIZE, M_TEMP, M_WAITOK); 4520 error = sooptcopyin(sopt, rule, RULE_MAXSIZE, 4521 sizeof(struct ip_fw) ); 4522 if (error == 0) 4523 error = check_ipfw_struct(rule, sopt->sopt_valsize); 4524 if (error == 0) { 4525 error = add_rule(&layer3_chain, rule); 4526 size = RULESIZE(rule); 4527 if (!error && sopt->sopt_dir == SOPT_GET) 4528 error = sooptcopyout(sopt, rule, size); 4529 } 4530 free(rule, M_TEMP); 4531 break; 4532 4533 case IP_FW_DEL: 4534 /* 4535 * IP_FW_DEL is used for deleting single rules or sets, 4536 * and (ab)used to atomically manipulate sets. Argument size 4537 * is used to distinguish between the two: 4538 * sizeof(u_int32_t) 4539 * delete single rule or set of rules, 4540 * or reassign rules (or sets) to a different set. 4541 * 2*sizeof(u_int32_t) 4542 * atomic disable/enable sets. 4543 * first u_int32_t contains sets to be disabled, 4544 * second u_int32_t contains sets to be enabled. 4545 */ 4546 error = sooptcopyin(sopt, rulenum, 4547 2*sizeof(u_int32_t), sizeof(u_int32_t)); 4548 if (error) 4549 break; 4550 size = sopt->sopt_valsize; 4551 if (size == sizeof(u_int32_t)) /* delete or reassign */ 4552 error = del_entry(&layer3_chain, rulenum[0]); 4553 else if (size == 2*sizeof(u_int32_t)) /* set enable/disable */ 4554 set_disable = 4555 (set_disable | rulenum[0]) & ~rulenum[1] & 4556 ~(1<<RESVD_SET); /* set RESVD_SET always enabled */ 4557 else 4558 error = EINVAL; 4559 break; 4560 4561 case IP_FW_ZERO: 4562 case IP_FW_RESETLOG: /* argument is an u_int_32, the rule number */ 4563 rulenum[0] = 0; 4564 if (sopt->sopt_val != 0) { 4565 error = sooptcopyin(sopt, rulenum, 4566 sizeof(u_int32_t), sizeof(u_int32_t)); 4567 if (error) 4568 break; 4569 } 4570 error = zero_entry(&layer3_chain, rulenum[0], 4571 sopt->sopt_name == IP_FW_RESETLOG); 4572 break; 4573 4574 case IP_FW_TABLE_ADD: 4575 { 4576 ipfw_table_entry ent; 4577 4578 error = sooptcopyin(sopt, &ent, 4579 sizeof(ent), sizeof(ent)); 4580 if (error) 4581 break; 4582 error = add_table_entry(&layer3_chain, ent.tbl, 4583 ent.addr, ent.masklen, ent.value); 4584 } 4585 break; 4586 4587 case IP_FW_TABLE_DEL: 4588 { 4589 ipfw_table_entry ent; 4590 4591 error = sooptcopyin(sopt, &ent, 4592 sizeof(ent), sizeof(ent)); 4593 if (error) 4594 break; 4595 error = del_table_entry(&layer3_chain, ent.tbl, 4596 ent.addr, ent.masklen); 4597 } 4598 break; 4599 4600 case IP_FW_TABLE_FLUSH: 4601 { 4602 u_int16_t tbl; 4603 4604 error = sooptcopyin(sopt, &tbl, 4605 sizeof(tbl), sizeof(tbl)); 4606 if (error) 4607 break; 4608 IPFW_WLOCK(&layer3_chain); 4609 error = flush_table(&layer3_chain, tbl); 4610 IPFW_WUNLOCK(&layer3_chain); 4611 } 4612 break; 4613 4614 case IP_FW_TABLE_GETSIZE: 4615 { 4616 u_int32_t tbl, cnt; 4617 4618 if ((error = sooptcopyin(sopt, &tbl, sizeof(tbl), 4619 sizeof(tbl)))) 4620 break; 4621 IPFW_RLOCK(&layer3_chain); 4622 error = count_table(&layer3_chain, tbl, &cnt); 4623 IPFW_RUNLOCK(&layer3_chain); 4624 if (error) 4625 break; 4626 error = sooptcopyout(sopt, &cnt, sizeof(cnt)); 4627 } 4628 break; 4629 4630 case IP_FW_TABLE_LIST: 4631 { 4632 ipfw_table *tbl; 4633 4634 if (sopt->sopt_valsize < sizeof(*tbl)) { 4635 error = EINVAL; 4636 break; 4637 } 4638 size = sopt->sopt_valsize; 4639 tbl = malloc(size, M_TEMP, M_WAITOK); 4640 error = sooptcopyin(sopt, tbl, size, sizeof(*tbl)); 4641 if (error) { 4642 free(tbl, M_TEMP); 4643 break; 4644 } 4645 tbl->size = (size - sizeof(*tbl)) / 4646 sizeof(ipfw_table_entry); 4647 IPFW_RLOCK(&layer3_chain); 4648 error = dump_table(&layer3_chain, tbl); 4649 IPFW_RUNLOCK(&layer3_chain); 4650 if (error) { 4651 free(tbl, M_TEMP); 4652 break; 4653 } 4654 error = sooptcopyout(sopt, tbl, size); 4655 free(tbl, M_TEMP); 4656 } 4657 break; 4658 4659#ifdef IPFIREWALL_NAT 4660 case IP_FW_NAT_CFG: 4661 { 4662 struct cfg_nat *ptr, *ser_n; 4663 char *buf; 4664 4665 buf = malloc(NAT_BUF_LEN, M_IPFW, M_WAITOK | M_ZERO); 4666 error = sooptcopyin(sopt, buf, NAT_BUF_LEN, 4667 sizeof(struct cfg_nat)); 4668 ser_n = (struct cfg_nat *)buf; 4669 4670 /* 4671 * Find/create nat rule. 4672 */ 4673 IPFW_WLOCK(&layer3_chain); 4674 ptr = lookup_nat(ser_n->id); 4675 if (ptr == NULL) { 4676 /* New rule: allocate and init new instance. */ 4677 ptr = malloc(sizeof(struct cfg_nat), 4678 M_IPFW, M_NOWAIT | M_ZERO); 4679 if (ptr == NULL) { 4680 IPFW_WUNLOCK(&layer3_chain); 4681 free(buf, M_IPFW); 4682 return (ENOSPC); 4683 } 4684 ptr->lib = LibAliasInit(NULL); 4685 if (ptr->lib == NULL) { 4686 IPFW_WUNLOCK(&layer3_chain); 4687 free(ptr, M_IPFW); 4688 free(buf, M_IPFW); 4689 return (EINVAL); 4690 } 4691 LIST_INIT(&ptr->redir_chain); 4692 } else { 4693 /* Entry already present: temporarly unhook it. */ 4694 UNHOOK_NAT(ptr); 4695 flush_nat_ptrs(ser_n->id); 4696 } 4697 IPFW_WUNLOCK(&layer3_chain); 4698 4699 /* 4700 * Basic nat configuration. 4701 */ 4702 ptr->id = ser_n->id; 4703 /* 4704 * XXX - what if this rule doesn't nat any ip and just 4705 * redirect? 4706 * do we set aliasaddress to 0.0.0.0? 4707 */ 4708 ptr->ip = ser_n->ip; 4709 ptr->redir_cnt = ser_n->redir_cnt; 4710 ptr->mode = ser_n->mode; 4711 LibAliasSetMode(ptr->lib, ser_n->mode, ser_n->mode); 4712 LibAliasSetAddress(ptr->lib, ptr->ip); 4713 memcpy(ptr->if_name, ser_n->if_name, IF_NAMESIZE); 4714 4715 /* 4716 * Redir and LSNAT configuration. 4717 */ 4718 /* Delete old cfgs. */ 4719 del_redir_spool_cfg(ptr, &ptr->redir_chain); 4720 /* Add new entries. */ 4721 add_redir_spool_cfg(&buf[(sizeof(struct cfg_nat))], ptr); 4722 free(buf, M_IPFW); 4723 IPFW_WLOCK(&layer3_chain); 4724 HOOK_NAT(&layer3_chain.nat, ptr); 4725 IPFW_WUNLOCK(&layer3_chain); 4726 } 4727 break; 4728 4729 case IP_FW_NAT_DEL: 4730 { 4731 struct cfg_nat *ptr; 4732 int i; 4733 4734 error = sooptcopyin(sopt, &i, sizeof i, sizeof i); 4735 IPFW_WLOCK(&layer3_chain); 4736 ptr = lookup_nat(i); 4737 if (ptr == NULL) { 4738 error = EINVAL; 4739 IPFW_WUNLOCK(&layer3_chain); 4740 break; 4741 } 4742 UNHOOK_NAT(ptr); 4743 flush_nat_ptrs(i); 4744 IPFW_WUNLOCK(&layer3_chain); 4745 del_redir_spool_cfg(ptr, &ptr->redir_chain); 4746 LibAliasUninit(ptr->lib); 4747 free(ptr, M_IPFW); 4748 } 4749 break; 4750 4751 case IP_FW_NAT_GET_CONFIG: 4752 { 4753 uint8_t *data; 4754 struct cfg_nat *n; 4755 struct cfg_redir *r; 4756 struct cfg_spool *s; 4757 int nat_cnt, off; 4758 4759 nat_cnt = 0; 4760 off = sizeof(nat_cnt); 4761 4762 data = malloc(NAT_BUF_LEN, M_IPFW, M_WAITOK | M_ZERO); 4763 IPFW_RLOCK(&layer3_chain); 4764 /* Serialize all the data. */ 4765 LIST_FOREACH(n, &layer3_chain.nat, _next) { 4766 nat_cnt++; 4767 if (off + SOF_NAT < NAT_BUF_LEN) { 4768 bcopy(n, &data[off], SOF_NAT); 4769 off += SOF_NAT; 4770 LIST_FOREACH(r, &n->redir_chain, _next) { 4771 if (off + SOF_REDIR < NAT_BUF_LEN) { 4772 bcopy(r, &data[off], 4773 SOF_REDIR); 4774 off += SOF_REDIR; 4775 LIST_FOREACH(s, &r->spool_chain, 4776 _next) { 4777 if (off + SOF_SPOOL < 4778 NAT_BUF_LEN) { 4779 bcopy(s, 4780 &data[off], 4781 SOF_SPOOL); 4782 off += 4783 SOF_SPOOL; 4784 } else 4785 goto nospace; 4786 } 4787 } else 4788 goto nospace; 4789 } 4790 } else 4791 goto nospace; 4792 } 4793 bcopy(&nat_cnt, data, sizeof(nat_cnt)); 4794 IPFW_RUNLOCK(&layer3_chain); 4795 error = sooptcopyout(sopt, data, NAT_BUF_LEN); 4796 free(data, M_IPFW); 4797 break; 4798 nospace: 4799 IPFW_RUNLOCK(&layer3_chain); 4800 printf("serialized data buffer not big enough:" 4801 "please increase NAT_BUF_LEN\n"); 4802 free(data, M_IPFW); 4803 } 4804 break; 4805 4806 case IP_FW_NAT_GET_LOG: 4807 { 4808 uint8_t *data; 4809 struct cfg_nat *ptr; 4810 int i, size, cnt, sof; 4811 4812 data = NULL; 4813 sof = LIBALIAS_BUF_SIZE; 4814 cnt = 0; 4815 4816 IPFW_RLOCK(&layer3_chain); 4817 size = i = 0; 4818 LIST_FOREACH(ptr, &layer3_chain.nat, _next) { 4819 if (ptr->lib->logDesc == NULL) 4820 continue; 4821 cnt++; 4822 size = cnt * (sof + sizeof(int)); 4823 data = realloc(data, size, M_IPFW, M_NOWAIT | M_ZERO); 4824 if (data == NULL) { 4825 IPFW_RUNLOCK(&layer3_chain); 4826 return (ENOSPC); 4827 } 4828 bcopy(&ptr->id, &data[i], sizeof(int)); 4829 i += sizeof(int); 4830 bcopy(ptr->lib->logDesc, &data[i], sof); 4831 i += sof; 4832 } 4833 IPFW_RUNLOCK(&layer3_chain); 4834 error = sooptcopyout(sopt, data, size); 4835 free(data, M_IPFW); 4836 } 4837 break; 4838#endif 4839 4840 default: 4841 printf("ipfw: ipfw_ctl invalid option %d\n", sopt->sopt_name); 4842 error = EINVAL; 4843 } 4844 4845 return (error); 4846#undef RULE_MAXSIZE 4847} 4848 4849/** 4850 * dummynet needs a reference to the default rule, because rules can be 4851 * deleted while packets hold a reference to them. When this happens, 4852 * dummynet changes the reference to the default rule (it could well be a 4853 * NULL pointer, but this way we do not need to check for the special 4854 * case, plus here he have info on the default behaviour). 4855 */ 4856struct ip_fw *ip_fw_default_rule; 4857 4858/* 4859 * This procedure is only used to handle keepalives. It is invoked 4860 * every dyn_keepalive_period 4861 */ 4862static void 4863ipfw_tick(void * __unused unused) 4864{ 4865 struct mbuf *m0, *m, *mnext, **mtailp; 4866 int i; 4867 ipfw_dyn_rule *q; 4868 4869 if (dyn_keepalive == 0 || ipfw_dyn_v == NULL || dyn_count == 0) 4870 goto done; 4871 4872 /* 4873 * We make a chain of packets to go out here -- not deferring 4874 * until after we drop the IPFW dynamic rule lock would result 4875 * in a lock order reversal with the normal packet input -> ipfw 4876 * call stack. 4877 */ 4878 m0 = NULL; 4879 mtailp = &m0; 4880 IPFW_DYN_LOCK(); 4881 for (i = 0 ; i < curr_dyn_buckets ; i++) { 4882 for (q = ipfw_dyn_v[i] ; q ; q = q->next ) { 4883 if (q->dyn_type == O_LIMIT_PARENT) 4884 continue; 4885 if (q->id.proto != IPPROTO_TCP) 4886 continue; 4887 if ( (q->state & BOTH_SYN) != BOTH_SYN) 4888 continue; 4889 if (TIME_LEQ( time_uptime+dyn_keepalive_interval, 4890 q->expire)) 4891 continue; /* too early */ 4892 if (TIME_LEQ(q->expire, time_uptime)) 4893 continue; /* too late, rule expired */ 4894 4895 *mtailp = send_pkt(NULL, &(q->id), q->ack_rev - 1, 4896 q->ack_fwd, TH_SYN); 4897 if (*mtailp != NULL) 4898 mtailp = &(*mtailp)->m_nextpkt; 4899 *mtailp = send_pkt(NULL, &(q->id), q->ack_fwd - 1, 4900 q->ack_rev, 0); 4901 if (*mtailp != NULL) 4902 mtailp = &(*mtailp)->m_nextpkt; 4903 } 4904 } 4905 IPFW_DYN_UNLOCK(); 4906 for (m = mnext = m0; m != NULL; m = mnext) { 4907 mnext = m->m_nextpkt; 4908 m->m_nextpkt = NULL; 4909 ip_output(m, NULL, NULL, 0, NULL, NULL); 4910 } 4911done: 4912 callout_reset(&ipfw_timeout, dyn_keepalive_period*hz, ipfw_tick, NULL); 4913} 4914 4915int 4916ipfw_init(void) 4917{ 4918 struct ip_fw default_rule; 4919 int error; 4920 4921#ifdef INET6 4922 /* Setup IPv6 fw sysctl tree. */ 4923 sysctl_ctx_init(&ip6_fw_sysctl_ctx); 4924 ip6_fw_sysctl_tree = SYSCTL_ADD_NODE(&ip6_fw_sysctl_ctx, 4925 SYSCTL_STATIC_CHILDREN(_net_inet6_ip6), OID_AUTO, "fw", 4926 CTLFLAG_RW | CTLFLAG_SECURE, 0, "Firewall"); 4927 SYSCTL_ADD_PROC(&ip6_fw_sysctl_ctx, SYSCTL_CHILDREN(ip6_fw_sysctl_tree), 4928 OID_AUTO, "enable", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3, 4929 &fw6_enable, 0, ipfw_chg_hook, "I", "Enable ipfw+6"); 4930 SYSCTL_ADD_INT(&ip6_fw_sysctl_ctx, SYSCTL_CHILDREN(ip6_fw_sysctl_tree), 4931 OID_AUTO, "deny_unknown_exthdrs", CTLFLAG_RW | CTLFLAG_SECURE, 4932 &fw_deny_unknown_exthdrs, 0, 4933 "Deny packets with unknown IPv6 Extension Headers"); 4934#endif 4935 4936 layer3_chain.rules = NULL; 4937 IPFW_LOCK_INIT(&layer3_chain); 4938 ipfw_dyn_rule_zone = uma_zcreate("IPFW dynamic rule", 4939 sizeof(ipfw_dyn_rule), NULL, NULL, NULL, NULL, 4940 UMA_ALIGN_PTR, 0); 4941 IPFW_DYN_LOCK_INIT(); 4942 callout_init(&ipfw_timeout, NET_CALLOUT_MPSAFE); 4943 4944 bzero(&default_rule, sizeof default_rule); 4945 4946 default_rule.act_ofs = 0; 4947 default_rule.rulenum = IPFW_DEFAULT_RULE; 4948 default_rule.cmd_len = 1; 4949 default_rule.set = RESVD_SET; 4950 4951 default_rule.cmd[0].len = 1; 4952 default_rule.cmd[0].opcode = 4953#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 4954 1 ? O_ACCEPT : 4955#endif 4956 O_DENY; 4957 4958 error = add_rule(&layer3_chain, &default_rule); 4959 if (error != 0) { 4960 printf("ipfw2: error %u initializing default rule " 4961 "(support disabled)\n", error); 4962 IPFW_DYN_LOCK_DESTROY(); 4963 IPFW_LOCK_DESTROY(&layer3_chain); 4964 uma_zdestroy(ipfw_dyn_rule_zone); 4965 return (error); 4966 } 4967 4968 ip_fw_default_rule = layer3_chain.rules; 4969 printf("ipfw2 " 4970#ifdef INET6 4971 "(+ipv6) " 4972#endif 4973 "initialized, divert %s, " 4974 "rule-based forwarding " 4975#ifdef IPFIREWALL_FORWARD 4976 "enabled, " 4977#else 4978 "disabled, " 4979#endif 4980 "default to %s, logging ", 4981#ifdef IPDIVERT 4982 "enabled", 4983#else 4984 "loadable", 4985#endif 4986 default_rule.cmd[0].opcode == O_ACCEPT ? "accept" : "deny"); 4987 4988#ifdef IPFIREWALL_VERBOSE 4989 fw_verbose = 1; 4990#endif 4991#ifdef IPFIREWALL_VERBOSE_LIMIT 4992 verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 4993#endif 4994 if (fw_verbose == 0) 4995 printf("disabled\n"); 4996 else if (verbose_limit == 0) 4997 printf("unlimited\n"); 4998 else 4999 printf("limited to %d packets/entry by default\n", 5000 verbose_limit); 5001 5002 error = init_tables(&layer3_chain); 5003 if (error) { 5004 IPFW_DYN_LOCK_DESTROY(); 5005 IPFW_LOCK_DESTROY(&layer3_chain); 5006 uma_zdestroy(ipfw_dyn_rule_zone); 5007 return (error); 5008 } 5009 ip_fw_ctl_ptr = ipfw_ctl; 5010 ip_fw_chk_ptr = ipfw_chk; 5011 callout_reset(&ipfw_timeout, hz, ipfw_tick, NULL); 5012#ifdef IPFIREWALL_NAT 5013 LIST_INIT(&layer3_chain.nat); 5014 ifaddr_event_tag = EVENTHANDLER_REGISTER(ifaddr_event, ifaddr_change, 5015 NULL, EVENTHANDLER_PRI_ANY); 5016#endif 5017 return (0); 5018} 5019 5020void 5021ipfw_destroy(void) 5022{ 5023 struct ip_fw *reap; 5024#ifdef IPFIREWALL_NAT 5025 struct cfg_nat *ptr, *ptr_temp; 5026#endif 5027 5028 ip_fw_chk_ptr = NULL; 5029 ip_fw_ctl_ptr = NULL; 5030 callout_drain(&ipfw_timeout); 5031 IPFW_WLOCK(&layer3_chain); 5032 flush_tables(&layer3_chain); 5033#ifdef IPFIREWALL_NAT 5034 LIST_FOREACH_SAFE(ptr, &layer3_chain.nat, _next, ptr_temp) { 5035 LIST_REMOVE(ptr, _next); 5036 del_redir_spool_cfg(ptr, &ptr->redir_chain); 5037 LibAliasUninit(ptr->lib); 5038 free(ptr, M_IPFW); 5039 } 5040 EVENTHANDLER_DEREGISTER(ifaddr_event, ifaddr_event_tag); 5041#endif 5042 layer3_chain.reap = NULL; 5043 free_chain(&layer3_chain, 1 /* kill default rule */); 5044 reap = layer3_chain.reap, layer3_chain.reap = NULL; 5045 IPFW_WUNLOCK(&layer3_chain); 5046 if (reap != NULL) 5047 reap_rules(reap); 5048 IPFW_DYN_LOCK_DESTROY(); 5049 uma_zdestroy(ipfw_dyn_rule_zone); 5050 IPFW_LOCK_DESTROY(&layer3_chain); 5051 5052#ifdef INET6 5053 /* Free IPv6 fw sysctl tree. */ 5054 sysctl_ctx_free(&ip6_fw_sysctl_ctx); 5055#endif 5056 5057 printf("IP firewall unloaded\n"); 5058} 5059