ip_fw2.c revision 172930
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 26#include <sys/cdefs.h> 27__FBSDID("$FreeBSD: head/sys/netinet/ip_fw2.c 172930 2007-10-24 19:04:04Z rwatson $"); 28 29#define DEB(x) 30#define DDB(x) x 31 32/* 33 * Implement IP packet firewall (new version) 34 */ 35 36#if !defined(KLD_MODULE) 37#include "opt_ipfw.h" 38#include "opt_ipdivert.h" 39#include "opt_ipdn.h" 40#include "opt_inet.h" 41#ifndef INET 42#error IPFIREWALL requires INET. 43#endif /* INET */ 44#endif 45#include "opt_inet6.h" 46#include "opt_ipsec.h" 47#include "opt_mac.h" 48 49#include <sys/param.h> 50#include <sys/systm.h> 51#include <sys/condvar.h> 52#include <sys/eventhandler.h> 53#include <sys/malloc.h> 54#include <sys/mbuf.h> 55#include <sys/kernel.h> 56#include <sys/lock.h> 57#include <sys/jail.h> 58#include <sys/module.h> 59#include <sys/priv.h> 60#include <sys/proc.h> 61#include <sys/rwlock.h> 62#include <sys/socket.h> 63#include <sys/socketvar.h> 64#include <sys/sysctl.h> 65#include <sys/syslog.h> 66#include <sys/ucred.h> 67#include <net/if.h> 68#include <net/radix.h> 69#include <net/route.h> 70#include <net/pf_mtag.h> 71#include <netinet/in.h> 72#include <netinet/in_systm.h> 73#include <netinet/in_var.h> 74#include <netinet/in_pcb.h> 75#include <netinet/ip.h> 76#include <netinet/ip_var.h> 77#include <netinet/ip_icmp.h> 78#include <netinet/ip_fw.h> 79#include <netinet/ip_divert.h> 80#include <netinet/ip_dummynet.h> 81#include <netinet/ip_carp.h> 82#include <netinet/pim.h> 83#include <netinet/tcp.h> 84#include <netinet/tcp_timer.h> 85#include <netinet/tcp_var.h> 86#include <netinet/tcpip.h> 87#include <netinet/udp.h> 88#include <netinet/udp_var.h> 89#include <netinet/sctp.h> 90#ifdef IPFIREWALL_NAT 91#include <netinet/libalias/alias.h> 92#include <netinet/libalias/alias_local.h> 93#endif 94#include <netgraph/ng_ipfw.h> 95 96#include <altq/if_altq.h> 97 98#include <netinet/ip6.h> 99#include <netinet/icmp6.h> 100#ifdef INET6 101#include <netinet6/scope6_var.h> 102#endif 103 104#include <netinet/if_ether.h> /* XXX for ETHERTYPE_IP */ 105 106#include <machine/in_cksum.h> /* XXX for in_cksum */ 107 108#include <security/mac/mac_framework.h> 109 110/* 111 * set_disable contains one bit per set value (0..31). 112 * If the bit is set, all rules with the corresponding set 113 * are disabled. Set RESVD_SET(31) is reserved for the default rule 114 * and rules that are not deleted by the flush command, 115 * and CANNOT be disabled. 116 * Rules in set RESVD_SET can only be deleted explicitly. 117 */ 118static u_int32_t set_disable; 119 120static int fw_verbose; 121static int verbose_limit; 122 123static struct callout ipfw_timeout; 124static uma_zone_t ipfw_dyn_rule_zone; 125#define IPFW_DEFAULT_RULE 65535 126 127/* 128 * Data structure to cache our ucred related 129 * information. This structure only gets used if 130 * the user specified UID/GID based constraints in 131 * a firewall rule. 132 */ 133struct ip_fw_ugid { 134 gid_t fw_groups[NGROUPS]; 135 int fw_ngroups; 136 uid_t fw_uid; 137 int fw_prid; 138}; 139 140#define IPFW_TABLES_MAX 128 141struct ip_fw_chain { 142 struct ip_fw *rules; /* list of rules */ 143 struct ip_fw *reap; /* list of rules to reap */ 144 LIST_HEAD(, cfg_nat) nat; /* list of nat entries */ 145 struct radix_node_head *tables[IPFW_TABLES_MAX]; 146 struct rwlock rwmtx; 147}; 148#define IPFW_LOCK_INIT(_chain) \ 149 rw_init(&(_chain)->rwmtx, "IPFW static rules") 150#define IPFW_LOCK_DESTROY(_chain) rw_destroy(&(_chain)->rwmtx) 151#define IPFW_WLOCK_ASSERT(_chain) rw_assert(&(_chain)->rwmtx, RA_WLOCKED) 152 153#define IPFW_RLOCK(p) rw_rlock(&(p)->rwmtx) 154#define IPFW_RUNLOCK(p) rw_runlock(&(p)->rwmtx) 155#define IPFW_WLOCK(p) rw_wlock(&(p)->rwmtx) 156#define IPFW_WUNLOCK(p) rw_wunlock(&(p)->rwmtx) 157 158/* 159 * list of rules for layer 3 160 */ 161static struct ip_fw_chain layer3_chain; 162 163MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's"); 164MALLOC_DEFINE(M_IPFW_TBL, "ipfw_tbl", "IpFw tables"); 165 166struct table_entry { 167 struct radix_node rn[2]; 168 struct sockaddr_in addr, mask; 169 u_int32_t value; 170}; 171 172static int fw_debug = 1; 173static int autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 174 175extern int ipfw_chg_hook(SYSCTL_HANDLER_ARGS); 176 177#ifdef SYSCTL_NODE 178SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 179SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, enable, 180 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3, &fw_enable, 0, 181 ipfw_chg_hook, "I", "Enable ipfw"); 182SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, CTLFLAG_RW, 183 &autoinc_step, 0, "Rule number autincrement step"); 184SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 185 CTLFLAG_RW | CTLFLAG_SECURE3, 186 &fw_one_pass, 0, 187 "Only do a single pass through ipfw when using dummynet(4)"); 188SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW, 189 &fw_debug, 0, "Enable printing of debug ip_fw statements"); 190SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, 191 CTLFLAG_RW | CTLFLAG_SECURE3, 192 &fw_verbose, 0, "Log matches to ipfw rules"); 193SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, 194 &verbose_limit, 0, "Set upper limit of matches of ipfw rules logged"); 195 196/* 197 * Description of dynamic rules. 198 * 199 * Dynamic rules are stored in lists accessed through a hash table 200 * (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can 201 * be modified through the sysctl variable dyn_buckets which is 202 * updated when the table becomes empty. 203 * 204 * XXX currently there is only one list, ipfw_dyn. 205 * 206 * When a packet is received, its address fields are first masked 207 * with the mask defined for the rule, then hashed, then matched 208 * against the entries in the corresponding list. 209 * Dynamic rules can be used for different purposes: 210 * + stateful rules; 211 * + enforcing limits on the number of sessions; 212 * + in-kernel NAT (not implemented yet) 213 * 214 * The lifetime of dynamic rules is regulated by dyn_*_lifetime, 215 * measured in seconds and depending on the flags. 216 * 217 * The total number of dynamic rules is stored in dyn_count. 218 * The max number of dynamic rules is dyn_max. When we reach 219 * the maximum number of rules we do not create anymore. This is 220 * done to avoid consuming too much memory, but also too much 221 * time when searching on each packet (ideally, we should try instead 222 * to put a limit on the length of the list on each bucket...). 223 * 224 * Each dynamic rule holds a pointer to the parent ipfw rule so 225 * we know what action to perform. Dynamic rules are removed when 226 * the parent rule is deleted. XXX we should make them survive. 227 * 228 * There are some limitations with dynamic rules -- we do not 229 * obey the 'randomized match', and we do not do multiple 230 * passes through the firewall. XXX check the latter!!! 231 */ 232static ipfw_dyn_rule **ipfw_dyn_v = NULL; 233static u_int32_t dyn_buckets = 256; /* must be power of 2 */ 234static u_int32_t curr_dyn_buckets = 256; /* must be power of 2 */ 235 236static struct mtx ipfw_dyn_mtx; /* mutex guarding dynamic rules */ 237#define IPFW_DYN_LOCK_INIT() \ 238 mtx_init(&ipfw_dyn_mtx, "IPFW dynamic rules", NULL, MTX_DEF) 239#define IPFW_DYN_LOCK_DESTROY() mtx_destroy(&ipfw_dyn_mtx) 240#define IPFW_DYN_LOCK() mtx_lock(&ipfw_dyn_mtx) 241#define IPFW_DYN_UNLOCK() mtx_unlock(&ipfw_dyn_mtx) 242#define IPFW_DYN_LOCK_ASSERT() mtx_assert(&ipfw_dyn_mtx, MA_OWNED) 243 244/* 245 * Timeouts for various events in handing dynamic rules. 246 */ 247static u_int32_t dyn_ack_lifetime = 300; 248static u_int32_t dyn_syn_lifetime = 20; 249static u_int32_t dyn_fin_lifetime = 1; 250static u_int32_t dyn_rst_lifetime = 1; 251static u_int32_t dyn_udp_lifetime = 10; 252static u_int32_t dyn_short_lifetime = 5; 253 254/* 255 * Keepalives are sent if dyn_keepalive is set. They are sent every 256 * dyn_keepalive_period seconds, in the last dyn_keepalive_interval 257 * seconds of lifetime of a rule. 258 * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower 259 * than dyn_keepalive_period. 260 */ 261 262static u_int32_t dyn_keepalive_interval = 20; 263static u_int32_t dyn_keepalive_period = 5; 264static u_int32_t dyn_keepalive = 1; /* do send keepalives */ 265 266static u_int32_t static_count; /* # of static rules */ 267static u_int32_t static_len; /* size in bytes of static rules */ 268static u_int32_t dyn_count; /* # of dynamic rules */ 269static u_int32_t dyn_max = 4096; /* max # of dynamic rules */ 270 271SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLFLAG_RW, 272 &dyn_buckets, 0, "Number of dyn. buckets"); 273SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_RD, 274 &curr_dyn_buckets, 0, "Current Number of dyn. buckets"); 275SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_RD, 276 &dyn_count, 0, "Number of dyn. rules"); 277SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_RW, 278 &dyn_max, 0, "Max number of dyn. rules"); 279SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, CTLFLAG_RD, 280 &static_count, 0, "Number of static rules"); 281SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_RW, 282 &dyn_ack_lifetime, 0, "Lifetime of dyn. rules for acks"); 283SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_RW, 284 &dyn_syn_lifetime, 0, "Lifetime of dyn. rules for syn"); 285SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, CTLFLAG_RW, 286 &dyn_fin_lifetime, 0, "Lifetime of dyn. rules for fin"); 287SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, CTLFLAG_RW, 288 &dyn_rst_lifetime, 0, "Lifetime of dyn. rules for rst"); 289SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime, CTLFLAG_RW, 290 &dyn_udp_lifetime, 0, "Lifetime of dyn. rules for UDP"); 291SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_RW, 292 &dyn_short_lifetime, 0, "Lifetime of dyn. rules for other situations"); 293SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_keepalive, CTLFLAG_RW, 294 &dyn_keepalive, 0, "Enable keepalives for dyn. rules"); 295 296#ifdef INET6 297/* 298 * IPv6 specific variables 299 */ 300SYSCTL_DECL(_net_inet6_ip6); 301 302static struct sysctl_ctx_list ip6_fw_sysctl_ctx; 303static struct sysctl_oid *ip6_fw_sysctl_tree; 304#endif /* INET6 */ 305#endif /* SYSCTL_NODE */ 306 307#ifdef IPFIREWALL_NAT 308MODULE_DEPEND(ipfw, libalias, 1, 1, 1); 309#endif 310static int fw_deny_unknown_exthdrs = 1; 311 312 313/* 314 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 315 * Other macros just cast void * into the appropriate type 316 */ 317#define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 318#define TCP(p) ((struct tcphdr *)(p)) 319#define SCTP(p) ((struct sctphdr *)(p)) 320#define UDP(p) ((struct udphdr *)(p)) 321#define ICMP(p) ((struct icmphdr *)(p)) 322#define ICMP6(p) ((struct icmp6_hdr *)(p)) 323 324static __inline int 325icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 326{ 327 int type = icmp->icmp_type; 328 329 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 330} 331 332#define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 333 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 334 335static int 336is_icmp_query(struct icmphdr *icmp) 337{ 338 int type = icmp->icmp_type; 339 340 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 341} 342#undef TT 343 344/* 345 * The following checks use two arrays of 8 or 16 bits to store the 346 * bits that we want set or clear, respectively. They are in the 347 * low and high half of cmd->arg1 or cmd->d[0]. 348 * 349 * We scan options and store the bits we find set. We succeed if 350 * 351 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 352 * 353 * The code is sometimes optimized not to store additional variables. 354 */ 355 356static int 357flags_match(ipfw_insn *cmd, u_int8_t bits) 358{ 359 u_char want_clear; 360 bits = ~bits; 361 362 if ( ((cmd->arg1 & 0xff) & bits) != 0) 363 return 0; /* some bits we want set were clear */ 364 want_clear = (cmd->arg1 >> 8) & 0xff; 365 if ( (want_clear & bits) != want_clear) 366 return 0; /* some bits we want clear were set */ 367 return 1; 368} 369 370static int 371ipopts_match(struct ip *ip, ipfw_insn *cmd) 372{ 373 int optlen, bits = 0; 374 u_char *cp = (u_char *)(ip + 1); 375 int x = (ip->ip_hl << 2) - sizeof (struct ip); 376 377 for (; x > 0; x -= optlen, cp += optlen) { 378 int opt = cp[IPOPT_OPTVAL]; 379 380 if (opt == IPOPT_EOL) 381 break; 382 if (opt == IPOPT_NOP) 383 optlen = 1; 384 else { 385 optlen = cp[IPOPT_OLEN]; 386 if (optlen <= 0 || optlen > x) 387 return 0; /* invalid or truncated */ 388 } 389 switch (opt) { 390 391 default: 392 break; 393 394 case IPOPT_LSRR: 395 bits |= IP_FW_IPOPT_LSRR; 396 break; 397 398 case IPOPT_SSRR: 399 bits |= IP_FW_IPOPT_SSRR; 400 break; 401 402 case IPOPT_RR: 403 bits |= IP_FW_IPOPT_RR; 404 break; 405 406 case IPOPT_TS: 407 bits |= IP_FW_IPOPT_TS; 408 break; 409 } 410 } 411 return (flags_match(cmd, bits)); 412} 413 414static int 415tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 416{ 417 int optlen, bits = 0; 418 u_char *cp = (u_char *)(tcp + 1); 419 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 420 421 for (; x > 0; x -= optlen, cp += optlen) { 422 int opt = cp[0]; 423 if (opt == TCPOPT_EOL) 424 break; 425 if (opt == TCPOPT_NOP) 426 optlen = 1; 427 else { 428 optlen = cp[1]; 429 if (optlen <= 0) 430 break; 431 } 432 433 switch (opt) { 434 435 default: 436 break; 437 438 case TCPOPT_MAXSEG: 439 bits |= IP_FW_TCPOPT_MSS; 440 break; 441 442 case TCPOPT_WINDOW: 443 bits |= IP_FW_TCPOPT_WINDOW; 444 break; 445 446 case TCPOPT_SACK_PERMITTED: 447 case TCPOPT_SACK: 448 bits |= IP_FW_TCPOPT_SACK; 449 break; 450 451 case TCPOPT_TIMESTAMP: 452 bits |= IP_FW_TCPOPT_TS; 453 break; 454 455 } 456 } 457 return (flags_match(cmd, bits)); 458} 459 460static int 461iface_match(struct ifnet *ifp, ipfw_insn_if *cmd) 462{ 463 if (ifp == NULL) /* no iface with this packet, match fails */ 464 return 0; 465 /* Check by name or by IP address */ 466 if (cmd->name[0] != '\0') { /* match by name */ 467 /* Check name */ 468 if (cmd->p.glob) { 469 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 470 return(1); 471 } else { 472 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 473 return(1); 474 } 475 } else { 476 struct ifaddr *ia; 477 478 /* XXX lock? */ 479 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 480 if (ia->ifa_addr->sa_family != AF_INET) 481 continue; 482 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 483 (ia->ifa_addr))->sin_addr.s_addr) 484 return(1); /* match */ 485 } 486 } 487 return(0); /* no match, fail ... */ 488} 489 490/* 491 * The verify_path function checks if a route to the src exists and 492 * if it is reachable via ifp (when provided). 493 * 494 * The 'verrevpath' option checks that the interface that an IP packet 495 * arrives on is the same interface that traffic destined for the 496 * packet's source address would be routed out of. The 'versrcreach' 497 * option just checks that the source address is reachable via any route 498 * (except default) in the routing table. These two are a measure to block 499 * forged packets. This is also commonly known as "anti-spoofing" or Unicast 500 * Reverse Path Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 501 * is purposely reminiscent of the Cisco IOS command, 502 * 503 * ip verify unicast reverse-path 504 * ip verify unicast source reachable-via any 505 * 506 * which implements the same functionality. But note that syntax is 507 * misleading. The check may be performed on all IP packets whether unicast, 508 * multicast, or broadcast. 509 */ 510static int 511verify_path(struct in_addr src, struct ifnet *ifp) 512{ 513 struct route ro; 514 struct sockaddr_in *dst; 515 516 bzero(&ro, sizeof(ro)); 517 518 dst = (struct sockaddr_in *)&(ro.ro_dst); 519 dst->sin_family = AF_INET; 520 dst->sin_len = sizeof(*dst); 521 dst->sin_addr = src; 522 rtalloc_ign(&ro, RTF_CLONING); 523 524 if (ro.ro_rt == NULL) 525 return 0; 526 527 /* 528 * If ifp is provided, check for equality with rtentry. 529 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 530 * in order to pass packets injected back by if_simloop(): 531 * if useloopback == 1 routing entry (via lo0) for our own address 532 * may exist, so we need to handle routing assymetry. 533 */ 534 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 535 RTFREE(ro.ro_rt); 536 return 0; 537 } 538 539 /* if no ifp provided, check if rtentry is not default route */ 540 if (ifp == NULL && 541 satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) { 542 RTFREE(ro.ro_rt); 543 return 0; 544 } 545 546 /* or if this is a blackhole/reject route */ 547 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 548 RTFREE(ro.ro_rt); 549 return 0; 550 } 551 552 /* found valid route */ 553 RTFREE(ro.ro_rt); 554 return 1; 555} 556 557#ifdef INET6 558/* 559 * ipv6 specific rules here... 560 */ 561static __inline int 562icmp6type_match (int type, ipfw_insn_u32 *cmd) 563{ 564 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 565} 566 567static int 568flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 569{ 570 int i; 571 for (i=0; i <= cmd->o.arg1; ++i ) 572 if (curr_flow == cmd->d[i] ) 573 return 1; 574 return 0; 575} 576 577/* support for IP6_*_ME opcodes */ 578static int 579search_ip6_addr_net (struct in6_addr * ip6_addr) 580{ 581 struct ifnet *mdc; 582 struct ifaddr *mdc2; 583 struct in6_ifaddr *fdm; 584 struct in6_addr copia; 585 586 TAILQ_FOREACH(mdc, &ifnet, if_link) 587 TAILQ_FOREACH(mdc2, &mdc->if_addrlist, ifa_list) { 588 if (mdc2->ifa_addr->sa_family == AF_INET6) { 589 fdm = (struct in6_ifaddr *)mdc2; 590 copia = fdm->ia_addr.sin6_addr; 591 /* need for leaving scope_id in the sock_addr */ 592 in6_clearscope(&copia); 593 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) 594 return 1; 595 } 596 } 597 return 0; 598} 599 600static int 601verify_path6(struct in6_addr *src, struct ifnet *ifp) 602{ 603 struct route_in6 ro; 604 struct sockaddr_in6 *dst; 605 606 bzero(&ro, sizeof(ro)); 607 608 dst = (struct sockaddr_in6 * )&(ro.ro_dst); 609 dst->sin6_family = AF_INET6; 610 dst->sin6_len = sizeof(*dst); 611 dst->sin6_addr = *src; 612 rtalloc_ign((struct route *)&ro, RTF_CLONING); 613 614 if (ro.ro_rt == NULL) 615 return 0; 616 617 /* 618 * if ifp is provided, check for equality with rtentry 619 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 620 * to support the case of sending packets to an address of our own. 621 * (where the former interface is the first argument of if_simloop() 622 * (=ifp), the latter is lo0) 623 */ 624 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 625 RTFREE(ro.ro_rt); 626 return 0; 627 } 628 629 /* if no ifp provided, check if rtentry is not default route */ 630 if (ifp == NULL && 631 IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) { 632 RTFREE(ro.ro_rt); 633 return 0; 634 } 635 636 /* or if this is a blackhole/reject route */ 637 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 638 RTFREE(ro.ro_rt); 639 return 0; 640 } 641 642 /* found valid route */ 643 RTFREE(ro.ro_rt); 644 return 1; 645 646} 647static __inline int 648hash_packet6(struct ipfw_flow_id *id) 649{ 650 u_int32_t i; 651 i = (id->dst_ip6.__u6_addr.__u6_addr32[2]) ^ 652 (id->dst_ip6.__u6_addr.__u6_addr32[3]) ^ 653 (id->src_ip6.__u6_addr.__u6_addr32[2]) ^ 654 (id->src_ip6.__u6_addr.__u6_addr32[3]) ^ 655 (id->dst_port) ^ (id->src_port); 656 return i; 657} 658 659static int 660is_icmp6_query(int icmp6_type) 661{ 662 if ((icmp6_type <= ICMP6_MAXTYPE) && 663 (icmp6_type == ICMP6_ECHO_REQUEST || 664 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 665 icmp6_type == ICMP6_WRUREQUEST || 666 icmp6_type == ICMP6_FQDN_QUERY || 667 icmp6_type == ICMP6_NI_QUERY)) 668 return (1); 669 670 return (0); 671} 672 673static void 674send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 675{ 676 struct mbuf *m; 677 678 m = args->m; 679 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 680 struct tcphdr *tcp; 681 tcp_seq ack, seq; 682 int flags; 683 struct { 684 struct ip6_hdr ip6; 685 struct tcphdr th; 686 } ti; 687 tcp = (struct tcphdr *)((char *)ip6 + hlen); 688 689 if ((tcp->th_flags & TH_RST) != 0) { 690 m_freem(m); 691 args->m = NULL; 692 return; 693 } 694 695 ti.ip6 = *ip6; 696 ti.th = *tcp; 697 ti.th.th_seq = ntohl(ti.th.th_seq); 698 ti.th.th_ack = ntohl(ti.th.th_ack); 699 ti.ip6.ip6_nxt = IPPROTO_TCP; 700 701 if (ti.th.th_flags & TH_ACK) { 702 ack = 0; 703 seq = ti.th.th_ack; 704 flags = TH_RST; 705 } else { 706 ack = ti.th.th_seq; 707 if ((m->m_flags & M_PKTHDR) != 0) { 708 /* 709 * total new data to ACK is: 710 * total packet length, 711 * minus the header length, 712 * minus the tcp header length. 713 */ 714 ack += m->m_pkthdr.len - hlen 715 - (ti.th.th_off << 2); 716 } else if (ip6->ip6_plen) { 717 ack += ntohs(ip6->ip6_plen) + sizeof(*ip6) - 718 hlen - (ti.th.th_off << 2); 719 } else { 720 m_freem(m); 721 return; 722 } 723 if (tcp->th_flags & TH_SYN) 724 ack++; 725 seq = 0; 726 flags = TH_RST|TH_ACK; 727 } 728 bcopy(&ti, ip6, sizeof(ti)); 729 /* 730 * m is only used to recycle the mbuf 731 * The data in it is never read so we don't need 732 * to correct the offsets or anything 733 */ 734 tcp_respond(NULL, ip6, tcp, m, ack, seq, flags); 735 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */ 736#if 0 737 /* 738 * Unlike above, the mbufs need to line up with the ip6 hdr, 739 * as the contents are read. We need to m_adj() the 740 * needed amount. 741 * The mbuf will however be thrown away so we can adjust it. 742 * Remember we did an m_pullup on it already so we 743 * can make some assumptions about contiguousness. 744 */ 745 if (args->L3offset) 746 m_adj(m, args->L3offset); 747#endif 748 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 749 } else 750 m_freem(m); 751 752 args->m = NULL; 753} 754 755#endif /* INET6 */ 756 757static u_int64_t norule_counter; /* counter for ipfw_log(NULL...) */ 758 759#define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0 760#define SNP(buf) buf, sizeof(buf) 761 762/* 763 * We enter here when we have a rule with O_LOG. 764 * XXX this function alone takes about 2Kbytes of code! 765 */ 766static void 767ipfw_log(struct ip_fw *f, u_int hlen, struct ip_fw_args *args, 768 struct mbuf *m, struct ifnet *oif, u_short offset, uint32_t tablearg, 769 struct ip *ip) 770{ 771 struct ether_header *eh = args->eh; 772 char *action; 773 int limit_reached = 0; 774 char action2[40], proto[128], fragment[32]; 775 776 fragment[0] = '\0'; 777 proto[0] = '\0'; 778 779 if (f == NULL) { /* bogus pkt */ 780 if (verbose_limit != 0 && norule_counter >= verbose_limit) 781 return; 782 norule_counter++; 783 if (norule_counter == verbose_limit) 784 limit_reached = verbose_limit; 785 action = "Refuse"; 786 } else { /* O_LOG is the first action, find the real one */ 787 ipfw_insn *cmd = ACTION_PTR(f); 788 ipfw_insn_log *l = (ipfw_insn_log *)cmd; 789 790 if (l->max_log != 0 && l->log_left == 0) 791 return; 792 l->log_left--; 793 if (l->log_left == 0) 794 limit_reached = l->max_log; 795 cmd += F_LEN(cmd); /* point to first action */ 796 if (cmd->opcode == O_ALTQ) { 797 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 798 799 snprintf(SNPARGS(action2, 0), "Altq %d", 800 altq->qid); 801 cmd += F_LEN(cmd); 802 } 803 if (cmd->opcode == O_PROB) 804 cmd += F_LEN(cmd); 805 806 if (cmd->opcode == O_TAG) 807 cmd += F_LEN(cmd); 808 809 action = action2; 810 switch (cmd->opcode) { 811 case O_DENY: 812 action = "Deny"; 813 break; 814 815 case O_REJECT: 816 if (cmd->arg1==ICMP_REJECT_RST) 817 action = "Reset"; 818 else if (cmd->arg1==ICMP_UNREACH_HOST) 819 action = "Reject"; 820 else 821 snprintf(SNPARGS(action2, 0), "Unreach %d", 822 cmd->arg1); 823 break; 824 825 case O_UNREACH6: 826 if (cmd->arg1==ICMP6_UNREACH_RST) 827 action = "Reset"; 828 else 829 snprintf(SNPARGS(action2, 0), "Unreach %d", 830 cmd->arg1); 831 break; 832 833 case O_ACCEPT: 834 action = "Accept"; 835 break; 836 case O_COUNT: 837 action = "Count"; 838 break; 839 case O_DIVERT: 840 snprintf(SNPARGS(action2, 0), "Divert %d", 841 cmd->arg1); 842 break; 843 case O_TEE: 844 snprintf(SNPARGS(action2, 0), "Tee %d", 845 cmd->arg1); 846 break; 847 case O_SKIPTO: 848 snprintf(SNPARGS(action2, 0), "SkipTo %d", 849 cmd->arg1); 850 break; 851 case O_PIPE: 852 snprintf(SNPARGS(action2, 0), "Pipe %d", 853 cmd->arg1); 854 break; 855 case O_QUEUE: 856 snprintf(SNPARGS(action2, 0), "Queue %d", 857 cmd->arg1); 858 break; 859 case O_FORWARD_IP: { 860 ipfw_insn_sa *sa = (ipfw_insn_sa *)cmd; 861 int len; 862 struct in_addr dummyaddr; 863 if (sa->sa.sin_addr.s_addr == INADDR_ANY) 864 dummyaddr.s_addr = htonl(tablearg); 865 else 866 dummyaddr.s_addr = sa->sa.sin_addr.s_addr; 867 868 len = snprintf(SNPARGS(action2, 0), "Forward to %s", 869 inet_ntoa(dummyaddr)); 870 871 if (sa->sa.sin_port) 872 snprintf(SNPARGS(action2, len), ":%d", 873 sa->sa.sin_port); 874 } 875 break; 876 case O_NETGRAPH: 877 snprintf(SNPARGS(action2, 0), "Netgraph %d", 878 cmd->arg1); 879 break; 880 case O_NGTEE: 881 snprintf(SNPARGS(action2, 0), "Ngtee %d", 882 cmd->arg1); 883 break; 884 case O_NAT: 885 action = "Nat"; 886 break; 887 default: 888 action = "UNKNOWN"; 889 break; 890 } 891 } 892 893 if (hlen == 0) { /* non-ip */ 894 snprintf(SNPARGS(proto, 0), "MAC"); 895 896 } else { 897 int len; 898 char src[48], dst[48]; 899 struct icmphdr *icmp; 900 struct tcphdr *tcp; 901 struct udphdr *udp; 902#ifdef INET6 903 struct ip6_hdr *ip6 = NULL; 904 struct icmp6_hdr *icmp6; 905#endif 906 src[0] = '\0'; 907 dst[0] = '\0'; 908#ifdef INET6 909 if (IS_IP6_FLOW_ID(&(args->f_id))) { 910 char ip6buf[INET6_ADDRSTRLEN]; 911 snprintf(src, sizeof(src), "[%s]", 912 ip6_sprintf(ip6buf, &args->f_id.src_ip6)); 913 snprintf(dst, sizeof(dst), "[%s]", 914 ip6_sprintf(ip6buf, &args->f_id.dst_ip6)); 915 916 ip6 = (struct ip6_hdr *)ip; 917 tcp = (struct tcphdr *)(((char *)ip) + hlen); 918 udp = (struct udphdr *)(((char *)ip) + hlen); 919 } else 920#endif 921 { 922 tcp = L3HDR(struct tcphdr, ip); 923 udp = L3HDR(struct udphdr, ip); 924 925 inet_ntoa_r(ip->ip_src, src); 926 inet_ntoa_r(ip->ip_dst, dst); 927 } 928 929 switch (args->f_id.proto) { 930 case IPPROTO_TCP: 931 len = snprintf(SNPARGS(proto, 0), "TCP %s", src); 932 if (offset == 0) 933 snprintf(SNPARGS(proto, len), ":%d %s:%d", 934 ntohs(tcp->th_sport), 935 dst, 936 ntohs(tcp->th_dport)); 937 else 938 snprintf(SNPARGS(proto, len), " %s", dst); 939 break; 940 941 case IPPROTO_UDP: 942 len = snprintf(SNPARGS(proto, 0), "UDP %s", src); 943 if (offset == 0) 944 snprintf(SNPARGS(proto, len), ":%d %s:%d", 945 ntohs(udp->uh_sport), 946 dst, 947 ntohs(udp->uh_dport)); 948 else 949 snprintf(SNPARGS(proto, len), " %s", dst); 950 break; 951 952 case IPPROTO_ICMP: 953 icmp = L3HDR(struct icmphdr, ip); 954 if (offset == 0) 955 len = snprintf(SNPARGS(proto, 0), 956 "ICMP:%u.%u ", 957 icmp->icmp_type, icmp->icmp_code); 958 else 959 len = snprintf(SNPARGS(proto, 0), "ICMP "); 960 len += snprintf(SNPARGS(proto, len), "%s", src); 961 snprintf(SNPARGS(proto, len), " %s", dst); 962 break; 963#ifdef INET6 964 case IPPROTO_ICMPV6: 965 icmp6 = (struct icmp6_hdr *)(((char *)ip) + hlen); 966 if (offset == 0) 967 len = snprintf(SNPARGS(proto, 0), 968 "ICMPv6:%u.%u ", 969 icmp6->icmp6_type, icmp6->icmp6_code); 970 else 971 len = snprintf(SNPARGS(proto, 0), "ICMPv6 "); 972 len += snprintf(SNPARGS(proto, len), "%s", src); 973 snprintf(SNPARGS(proto, len), " %s", dst); 974 break; 975#endif 976 default: 977 len = snprintf(SNPARGS(proto, 0), "P:%d %s", 978 args->f_id.proto, src); 979 snprintf(SNPARGS(proto, len), " %s", dst); 980 break; 981 } 982 983#ifdef INET6 984 if (IS_IP6_FLOW_ID(&(args->f_id))) { 985 if (offset & (IP6F_OFF_MASK | IP6F_MORE_FRAG)) 986 snprintf(SNPARGS(fragment, 0), 987 " (frag %08x:%d@%d%s)", 988 args->f_id.frag_id6, 989 ntohs(ip6->ip6_plen) - hlen, 990 ntohs(offset & IP6F_OFF_MASK) << 3, 991 (offset & IP6F_MORE_FRAG) ? "+" : ""); 992 } else 993#endif 994 { 995 int ip_off, ip_len; 996 if (eh != NULL) { /* layer 2 packets are as on the wire */ 997 ip_off = ntohs(ip->ip_off); 998 ip_len = ntohs(ip->ip_len); 999 } else { 1000 ip_off = ip->ip_off; 1001 ip_len = ip->ip_len; 1002 } 1003 if (ip_off & (IP_MF | IP_OFFMASK)) 1004 snprintf(SNPARGS(fragment, 0), 1005 " (frag %d:%d@%d%s)", 1006 ntohs(ip->ip_id), ip_len - (ip->ip_hl << 2), 1007 offset << 3, 1008 (ip_off & IP_MF) ? "+" : ""); 1009 } 1010 } 1011 if (oif || m->m_pkthdr.rcvif) 1012 log(LOG_SECURITY | LOG_INFO, 1013 "ipfw: %d %s %s %s via %s%s\n", 1014 f ? f->rulenum : -1, 1015 action, proto, oif ? "out" : "in", 1016 oif ? oif->if_xname : m->m_pkthdr.rcvif->if_xname, 1017 fragment); 1018 else 1019 log(LOG_SECURITY | LOG_INFO, 1020 "ipfw: %d %s %s [no if info]%s\n", 1021 f ? f->rulenum : -1, 1022 action, proto, fragment); 1023 if (limit_reached) 1024 log(LOG_SECURITY | LOG_NOTICE, 1025 "ipfw: limit %d reached on entry %d\n", 1026 limit_reached, f ? f->rulenum : -1); 1027} 1028 1029/* 1030 * IMPORTANT: the hash function for dynamic rules must be commutative 1031 * in source and destination (ip,port), because rules are bidirectional 1032 * and we want to find both in the same bucket. 1033 */ 1034static __inline int 1035hash_packet(struct ipfw_flow_id *id) 1036{ 1037 u_int32_t i; 1038 1039#ifdef INET6 1040 if (IS_IP6_FLOW_ID(id)) 1041 i = hash_packet6(id); 1042 else 1043#endif /* INET6 */ 1044 i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port); 1045 i &= (curr_dyn_buckets - 1); 1046 return i; 1047} 1048 1049/** 1050 * unlink a dynamic rule from a chain. prev is a pointer to 1051 * the previous one, q is a pointer to the rule to delete, 1052 * head is a pointer to the head of the queue. 1053 * Modifies q and potentially also head. 1054 */ 1055#define UNLINK_DYN_RULE(prev, head, q) { \ 1056 ipfw_dyn_rule *old_q = q; \ 1057 \ 1058 /* remove a refcount to the parent */ \ 1059 if (q->dyn_type == O_LIMIT) \ 1060 q->parent->count--; \ 1061 DEB(printf("ipfw: unlink entry 0x%08x %d -> 0x%08x %d, %d left\n",\ 1062 (q->id.src_ip), (q->id.src_port), \ 1063 (q->id.dst_ip), (q->id.dst_port), dyn_count-1 ); ) \ 1064 if (prev != NULL) \ 1065 prev->next = q = q->next; \ 1066 else \ 1067 head = q = q->next; \ 1068 dyn_count--; \ 1069 uma_zfree(ipfw_dyn_rule_zone, old_q); } 1070 1071#define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0) 1072 1073/** 1074 * Remove dynamic rules pointing to "rule", or all of them if rule == NULL. 1075 * 1076 * If keep_me == NULL, rules are deleted even if not expired, 1077 * otherwise only expired rules are removed. 1078 * 1079 * The value of the second parameter is also used to point to identify 1080 * a rule we absolutely do not want to remove (e.g. because we are 1081 * holding a reference to it -- this is the case with O_LIMIT_PARENT 1082 * rules). The pointer is only used for comparison, so any non-null 1083 * value will do. 1084 */ 1085static void 1086remove_dyn_rule(struct ip_fw *rule, ipfw_dyn_rule *keep_me) 1087{ 1088 static u_int32_t last_remove = 0; 1089 1090#define FORCE (keep_me == NULL) 1091 1092 ipfw_dyn_rule *prev, *q; 1093 int i, pass = 0, max_pass = 0; 1094 1095 IPFW_DYN_LOCK_ASSERT(); 1096 1097 if (ipfw_dyn_v == NULL || dyn_count == 0) 1098 return; 1099 /* do not expire more than once per second, it is useless */ 1100 if (!FORCE && last_remove == time_uptime) 1101 return; 1102 last_remove = time_uptime; 1103 1104 /* 1105 * because O_LIMIT refer to parent rules, during the first pass only 1106 * remove child and mark any pending LIMIT_PARENT, and remove 1107 * them in a second pass. 1108 */ 1109next_pass: 1110 for (i = 0 ; i < curr_dyn_buckets ; i++) { 1111 for (prev=NULL, q = ipfw_dyn_v[i] ; q ; ) { 1112 /* 1113 * Logic can become complex here, so we split tests. 1114 */ 1115 if (q == keep_me) 1116 goto next; 1117 if (rule != NULL && rule != q->rule) 1118 goto next; /* not the one we are looking for */ 1119 if (q->dyn_type == O_LIMIT_PARENT) { 1120 /* 1121 * handle parent in the second pass, 1122 * record we need one. 1123 */ 1124 max_pass = 1; 1125 if (pass == 0) 1126 goto next; 1127 if (FORCE && q->count != 0 ) { 1128 /* XXX should not happen! */ 1129 printf("ipfw: OUCH! cannot remove rule," 1130 " count %d\n", q->count); 1131 } 1132 } else { 1133 if (!FORCE && 1134 !TIME_LEQ( q->expire, time_uptime )) 1135 goto next; 1136 } 1137 if (q->dyn_type != O_LIMIT_PARENT || !q->count) { 1138 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q); 1139 continue; 1140 } 1141next: 1142 prev=q; 1143 q=q->next; 1144 } 1145 } 1146 if (pass++ < max_pass) 1147 goto next_pass; 1148} 1149 1150 1151/** 1152 * lookup a dynamic rule. 1153 */ 1154static ipfw_dyn_rule * 1155lookup_dyn_rule_locked(struct ipfw_flow_id *pkt, int *match_direction, 1156 struct tcphdr *tcp) 1157{ 1158 /* 1159 * stateful ipfw extensions. 1160 * Lookup into dynamic session queue 1161 */ 1162#define MATCH_REVERSE 0 1163#define MATCH_FORWARD 1 1164#define MATCH_NONE 2 1165#define MATCH_UNKNOWN 3 1166 int i, dir = MATCH_NONE; 1167 ipfw_dyn_rule *prev, *q=NULL; 1168 1169 IPFW_DYN_LOCK_ASSERT(); 1170 1171 if (ipfw_dyn_v == NULL) 1172 goto done; /* not found */ 1173 i = hash_packet( pkt ); 1174 for (prev=NULL, q = ipfw_dyn_v[i] ; q != NULL ; ) { 1175 if (q->dyn_type == O_LIMIT_PARENT && q->count) 1176 goto next; 1177 if (TIME_LEQ( q->expire, time_uptime)) { /* expire entry */ 1178 UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q); 1179 continue; 1180 } 1181 if (pkt->proto == q->id.proto && 1182 q->dyn_type != O_LIMIT_PARENT) { 1183 if (IS_IP6_FLOW_ID(pkt)) { 1184 if (IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1185 &(q->id.src_ip6)) && 1186 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1187 &(q->id.dst_ip6)) && 1188 pkt->src_port == q->id.src_port && 1189 pkt->dst_port == q->id.dst_port ) { 1190 dir = MATCH_FORWARD; 1191 break; 1192 } 1193 if (IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1194 &(q->id.dst_ip6)) && 1195 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1196 &(q->id.src_ip6)) && 1197 pkt->src_port == q->id.dst_port && 1198 pkt->dst_port == q->id.src_port ) { 1199 dir = MATCH_REVERSE; 1200 break; 1201 } 1202 } else { 1203 if (pkt->src_ip == q->id.src_ip && 1204 pkt->dst_ip == q->id.dst_ip && 1205 pkt->src_port == q->id.src_port && 1206 pkt->dst_port == q->id.dst_port ) { 1207 dir = MATCH_FORWARD; 1208 break; 1209 } 1210 if (pkt->src_ip == q->id.dst_ip && 1211 pkt->dst_ip == q->id.src_ip && 1212 pkt->src_port == q->id.dst_port && 1213 pkt->dst_port == q->id.src_port ) { 1214 dir = MATCH_REVERSE; 1215 break; 1216 } 1217 } 1218 } 1219next: 1220 prev = q; 1221 q = q->next; 1222 } 1223 if (q == NULL) 1224 goto done; /* q = NULL, not found */ 1225 1226 if ( prev != NULL) { /* found and not in front */ 1227 prev->next = q->next; 1228 q->next = ipfw_dyn_v[i]; 1229 ipfw_dyn_v[i] = q; 1230 } 1231 if (pkt->proto == IPPROTO_TCP) { /* update state according to flags */ 1232 u_char flags = pkt->flags & (TH_FIN|TH_SYN|TH_RST); 1233 1234#define BOTH_SYN (TH_SYN | (TH_SYN << 8)) 1235#define BOTH_FIN (TH_FIN | (TH_FIN << 8)) 1236 q->state |= (dir == MATCH_FORWARD ) ? flags : (flags << 8); 1237 switch (q->state) { 1238 case TH_SYN: /* opening */ 1239 q->expire = time_uptime + dyn_syn_lifetime; 1240 break; 1241 1242 case BOTH_SYN: /* move to established */ 1243 case BOTH_SYN | TH_FIN : /* one side tries to close */ 1244 case BOTH_SYN | (TH_FIN << 8) : 1245 if (tcp) { 1246#define _SEQ_GE(a,b) ((int)(a) - (int)(b) >= 0) 1247 u_int32_t ack = ntohl(tcp->th_ack); 1248 if (dir == MATCH_FORWARD) { 1249 if (q->ack_fwd == 0 || _SEQ_GE(ack, q->ack_fwd)) 1250 q->ack_fwd = ack; 1251 else { /* ignore out-of-sequence */ 1252 break; 1253 } 1254 } else { 1255 if (q->ack_rev == 0 || _SEQ_GE(ack, q->ack_rev)) 1256 q->ack_rev = ack; 1257 else { /* ignore out-of-sequence */ 1258 break; 1259 } 1260 } 1261 } 1262 q->expire = time_uptime + dyn_ack_lifetime; 1263 break; 1264 1265 case BOTH_SYN | BOTH_FIN: /* both sides closed */ 1266 if (dyn_fin_lifetime >= dyn_keepalive_period) 1267 dyn_fin_lifetime = dyn_keepalive_period - 1; 1268 q->expire = time_uptime + dyn_fin_lifetime; 1269 break; 1270 1271 default: 1272#if 0 1273 /* 1274 * reset or some invalid combination, but can also 1275 * occur if we use keep-state the wrong way. 1276 */ 1277 if ( (q->state & ((TH_RST << 8)|TH_RST)) == 0) 1278 printf("invalid state: 0x%x\n", q->state); 1279#endif 1280 if (dyn_rst_lifetime >= dyn_keepalive_period) 1281 dyn_rst_lifetime = dyn_keepalive_period - 1; 1282 q->expire = time_uptime + dyn_rst_lifetime; 1283 break; 1284 } 1285 } else if (pkt->proto == IPPROTO_UDP) { 1286 q->expire = time_uptime + dyn_udp_lifetime; 1287 } else { 1288 /* other protocols */ 1289 q->expire = time_uptime + dyn_short_lifetime; 1290 } 1291done: 1292 if (match_direction) 1293 *match_direction = dir; 1294 return q; 1295} 1296 1297static ipfw_dyn_rule * 1298lookup_dyn_rule(struct ipfw_flow_id *pkt, int *match_direction, 1299 struct tcphdr *tcp) 1300{ 1301 ipfw_dyn_rule *q; 1302 1303 IPFW_DYN_LOCK(); 1304 q = lookup_dyn_rule_locked(pkt, match_direction, tcp); 1305 if (q == NULL) 1306 IPFW_DYN_UNLOCK(); 1307 /* NB: return table locked when q is not NULL */ 1308 return q; 1309} 1310 1311static void 1312realloc_dynamic_table(void) 1313{ 1314 IPFW_DYN_LOCK_ASSERT(); 1315 1316 /* 1317 * Try reallocation, make sure we have a power of 2 and do 1318 * not allow more than 64k entries. In case of overflow, 1319 * default to 1024. 1320 */ 1321 1322 if (dyn_buckets > 65536) 1323 dyn_buckets = 1024; 1324 if ((dyn_buckets & (dyn_buckets-1)) != 0) { /* not a power of 2 */ 1325 dyn_buckets = curr_dyn_buckets; /* reset */ 1326 return; 1327 } 1328 curr_dyn_buckets = dyn_buckets; 1329 if (ipfw_dyn_v != NULL) 1330 free(ipfw_dyn_v, M_IPFW); 1331 for (;;) { 1332 ipfw_dyn_v = malloc(curr_dyn_buckets * sizeof(ipfw_dyn_rule *), 1333 M_IPFW, M_NOWAIT | M_ZERO); 1334 if (ipfw_dyn_v != NULL || curr_dyn_buckets <= 2) 1335 break; 1336 curr_dyn_buckets /= 2; 1337 } 1338} 1339 1340/** 1341 * Install state of type 'type' for a dynamic session. 1342 * The hash table contains two type of rules: 1343 * - regular rules (O_KEEP_STATE) 1344 * - rules for sessions with limited number of sess per user 1345 * (O_LIMIT). When they are created, the parent is 1346 * increased by 1, and decreased on delete. In this case, 1347 * the third parameter is the parent rule and not the chain. 1348 * - "parent" rules for the above (O_LIMIT_PARENT). 1349 */ 1350static ipfw_dyn_rule * 1351add_dyn_rule(struct ipfw_flow_id *id, u_int8_t dyn_type, struct ip_fw *rule) 1352{ 1353 ipfw_dyn_rule *r; 1354 int i; 1355 1356 IPFW_DYN_LOCK_ASSERT(); 1357 1358 if (ipfw_dyn_v == NULL || 1359 (dyn_count == 0 && dyn_buckets != curr_dyn_buckets)) { 1360 realloc_dynamic_table(); 1361 if (ipfw_dyn_v == NULL) 1362 return NULL; /* failed ! */ 1363 } 1364 i = hash_packet(id); 1365 1366 r = uma_zalloc(ipfw_dyn_rule_zone, M_NOWAIT | M_ZERO); 1367 if (r == NULL) { 1368 printf ("ipfw: sorry cannot allocate state\n"); 1369 return NULL; 1370 } 1371 1372 /* increase refcount on parent, and set pointer */ 1373 if (dyn_type == O_LIMIT) { 1374 ipfw_dyn_rule *parent = (ipfw_dyn_rule *)rule; 1375 if ( parent->dyn_type != O_LIMIT_PARENT) 1376 panic("invalid parent"); 1377 parent->count++; 1378 r->parent = parent; 1379 rule = parent->rule; 1380 } 1381 1382 r->id = *id; 1383 r->expire = time_uptime + dyn_syn_lifetime; 1384 r->rule = rule; 1385 r->dyn_type = dyn_type; 1386 r->pcnt = r->bcnt = 0; 1387 r->count = 0; 1388 1389 r->bucket = i; 1390 r->next = ipfw_dyn_v[i]; 1391 ipfw_dyn_v[i] = r; 1392 dyn_count++; 1393 DEB(printf("ipfw: add dyn entry ty %d 0x%08x %d -> 0x%08x %d, total %d\n", 1394 dyn_type, 1395 (r->id.src_ip), (r->id.src_port), 1396 (r->id.dst_ip), (r->id.dst_port), 1397 dyn_count ); ) 1398 return r; 1399} 1400 1401/** 1402 * lookup dynamic parent rule using pkt and rule as search keys. 1403 * If the lookup fails, then install one. 1404 */ 1405static ipfw_dyn_rule * 1406lookup_dyn_parent(struct ipfw_flow_id *pkt, struct ip_fw *rule) 1407{ 1408 ipfw_dyn_rule *q; 1409 int i; 1410 1411 IPFW_DYN_LOCK_ASSERT(); 1412 1413 if (ipfw_dyn_v) { 1414 int is_v6 = IS_IP6_FLOW_ID(pkt); 1415 i = hash_packet( pkt ); 1416 for (q = ipfw_dyn_v[i] ; q != NULL ; q=q->next) 1417 if (q->dyn_type == O_LIMIT_PARENT && 1418 rule== q->rule && 1419 pkt->proto == q->id.proto && 1420 pkt->src_port == q->id.src_port && 1421 pkt->dst_port == q->id.dst_port && 1422 ( 1423 (is_v6 && 1424 IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6), 1425 &(q->id.src_ip6)) && 1426 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6), 1427 &(q->id.dst_ip6))) || 1428 (!is_v6 && 1429 pkt->src_ip == q->id.src_ip && 1430 pkt->dst_ip == q->id.dst_ip) 1431 ) 1432 ) { 1433 q->expire = time_uptime + dyn_short_lifetime; 1434 DEB(printf("ipfw: lookup_dyn_parent found 0x%p\n",q);) 1435 return q; 1436 } 1437 } 1438 return add_dyn_rule(pkt, O_LIMIT_PARENT, rule); 1439} 1440 1441/** 1442 * Install dynamic state for rule type cmd->o.opcode 1443 * 1444 * Returns 1 (failure) if state is not installed because of errors or because 1445 * session limitations are enforced. 1446 */ 1447static int 1448install_state(struct ip_fw *rule, ipfw_insn_limit *cmd, 1449 struct ip_fw_args *args, uint32_t tablearg) 1450{ 1451 static int last_log; 1452 ipfw_dyn_rule *q; 1453 struct in_addr da; 1454 char src[48], dst[48]; 1455 1456 src[0] = '\0'; 1457 dst[0] = '\0'; 1458 1459 DEB( 1460 printf("ipfw: %s: type %d 0x%08x %u -> 0x%08x %u\n", 1461 __func__, cmd->o.opcode, 1462 (args->f_id.src_ip), (args->f_id.src_port), 1463 (args->f_id.dst_ip), (args->f_id.dst_port)); 1464 ) 1465 1466 IPFW_DYN_LOCK(); 1467 1468 q = lookup_dyn_rule_locked(&args->f_id, NULL, NULL); 1469 1470 if (q != NULL) { /* should never occur */ 1471 if (last_log != time_uptime) { 1472 last_log = time_uptime; 1473 printf("ipfw: %s: entry already present, done\n", 1474 __func__); 1475 } 1476 IPFW_DYN_UNLOCK(); 1477 return (0); 1478 } 1479 1480 if (dyn_count >= dyn_max) 1481 /* Run out of slots, try to remove any expired rule. */ 1482 remove_dyn_rule(NULL, (ipfw_dyn_rule *)1); 1483 1484 if (dyn_count >= dyn_max) { 1485 if (last_log != time_uptime) { 1486 last_log = time_uptime; 1487 printf("ipfw: %s: Too many dynamic rules\n", __func__); 1488 } 1489 IPFW_DYN_UNLOCK(); 1490 return (1); /* cannot install, notify caller */ 1491 } 1492 1493 switch (cmd->o.opcode) { 1494 case O_KEEP_STATE: /* bidir rule */ 1495 add_dyn_rule(&args->f_id, O_KEEP_STATE, rule); 1496 break; 1497 1498 case O_LIMIT: { /* limit number of sessions */ 1499 struct ipfw_flow_id id; 1500 ipfw_dyn_rule *parent; 1501 uint32_t conn_limit; 1502 uint16_t limit_mask = cmd->limit_mask; 1503 1504 conn_limit = (cmd->conn_limit == IP_FW_TABLEARG) ? 1505 tablearg : cmd->conn_limit; 1506 1507 DEB( 1508 if (cmd->conn_limit == IP_FW_TABLEARG) 1509 printf("ipfw: %s: O_LIMIT rule, conn_limit: %u " 1510 "(tablearg)\n", __func__, conn_limit); 1511 else 1512 printf("ipfw: %s: O_LIMIT rule, conn_limit: %u\n", 1513 __func__, conn_limit); 1514 ) 1515 1516 id.dst_ip = id.src_ip = id.dst_port = id.src_port = 0; 1517 id.proto = args->f_id.proto; 1518 id.addr_type = args->f_id.addr_type; 1519 1520 if (IS_IP6_FLOW_ID (&(args->f_id))) { 1521 if (limit_mask & DYN_SRC_ADDR) 1522 id.src_ip6 = args->f_id.src_ip6; 1523 if (limit_mask & DYN_DST_ADDR) 1524 id.dst_ip6 = args->f_id.dst_ip6; 1525 } else { 1526 if (limit_mask & DYN_SRC_ADDR) 1527 id.src_ip = args->f_id.src_ip; 1528 if (limit_mask & DYN_DST_ADDR) 1529 id.dst_ip = args->f_id.dst_ip; 1530 } 1531 if (limit_mask & DYN_SRC_PORT) 1532 id.src_port = args->f_id.src_port; 1533 if (limit_mask & DYN_DST_PORT) 1534 id.dst_port = args->f_id.dst_port; 1535 if ((parent = lookup_dyn_parent(&id, rule)) == NULL) { 1536 printf("ipfw: %s: add parent failed\n", __func__); 1537 IPFW_DYN_UNLOCK(); 1538 return (1); 1539 } 1540 1541 if (parent->count >= conn_limit) { 1542 /* See if we can remove some expired rule. */ 1543 remove_dyn_rule(rule, parent); 1544 if (parent->count >= conn_limit) { 1545 if (fw_verbose && last_log != time_uptime) { 1546 last_log = time_uptime; 1547#ifdef INET6 1548 /* 1549 * XXX IPv6 flows are not 1550 * supported yet. 1551 */ 1552 if (IS_IP6_FLOW_ID(&(args->f_id))) { 1553 char ip6buf[INET6_ADDRSTRLEN]; 1554 snprintf(src, sizeof(src), 1555 "[%s]", ip6_sprintf(ip6buf, 1556 &args->f_id.src_ip6)); 1557 snprintf(dst, sizeof(dst), 1558 "[%s]", ip6_sprintf(ip6buf, 1559 &args->f_id.dst_ip6)); 1560 } else 1561#endif 1562 { 1563 da.s_addr = 1564 htonl(args->f_id.src_ip); 1565 inet_ntoa_r(da, src); 1566 da.s_addr = 1567 htonl(args->f_id.dst_ip); 1568 inet_ntoa_r(da, dst); 1569 } 1570 log(LOG_SECURITY | LOG_DEBUG, 1571 "ipfw: %d %s %s:%u -> %s:%u, %s\n", 1572 parent->rule->rulenum, 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_mbuf_create_netlayer(replyto, m); 1623 else 1624 mac_mbuf_create_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 pf_mtag *at; 3062 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 3063 3064 match = 1; 3065 at = pf_find_mtag(m); 3066 if (at != NULL && at->qid != 0) 3067 break; 3068 at = pf_get_mtag(m); 3069 if (at == NULL) { 3070 /* 3071 * Let the packet fall back to the 3072 * default ALTQ. 3073 */ 3074 break; 3075 } 3076 at->qid = altq->qid; 3077 if (is_ipv4) 3078 at->af = AF_INET; 3079 else 3080 at->af = AF_LINK; 3081 at->hdr = ip; 3082 break; 3083 } 3084 3085 case O_LOG: 3086 if (fw_verbose) 3087 ipfw_log(f, hlen, args, m, 3088 oif, offset, tablearg, ip); 3089 match = 1; 3090 break; 3091 3092 case O_PROB: 3093 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 3094 break; 3095 3096 case O_VERREVPATH: 3097 /* Outgoing packets automatically pass/match */ 3098 match = ((oif != NULL) || 3099 (m->m_pkthdr.rcvif == NULL) || 3100 ( 3101#ifdef INET6 3102 is_ipv6 ? 3103 verify_path6(&(args->f_id.src_ip6), 3104 m->m_pkthdr.rcvif) : 3105#endif 3106 verify_path(src_ip, m->m_pkthdr.rcvif))); 3107 break; 3108 3109 case O_VERSRCREACH: 3110 /* Outgoing packets automatically pass/match */ 3111 match = (hlen > 0 && ((oif != NULL) || 3112#ifdef INET6 3113 is_ipv6 ? 3114 verify_path6(&(args->f_id.src_ip6), 3115 NULL) : 3116#endif 3117 verify_path(src_ip, NULL))); 3118 break; 3119 3120 case O_ANTISPOOF: 3121 /* Outgoing packets automatically pass/match */ 3122 if (oif == NULL && hlen > 0 && 3123 ( (is_ipv4 && in_localaddr(src_ip)) 3124#ifdef INET6 3125 || (is_ipv6 && 3126 in6_localaddr(&(args->f_id.src_ip6))) 3127#endif 3128 )) 3129 match = 3130#ifdef INET6 3131 is_ipv6 ? verify_path6( 3132 &(args->f_id.src_ip6), 3133 m->m_pkthdr.rcvif) : 3134#endif 3135 verify_path(src_ip, 3136 m->m_pkthdr.rcvif); 3137 else 3138 match = 1; 3139 break; 3140 3141 case O_IPSEC: 3142#ifdef IPSEC 3143 match = (m_tag_find(m, 3144 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 3145#endif 3146 /* otherwise no match */ 3147 break; 3148 3149#ifdef INET6 3150 case O_IP6_SRC: 3151 match = is_ipv6 && 3152 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 3153 &((ipfw_insn_ip6 *)cmd)->addr6); 3154 break; 3155 3156 case O_IP6_DST: 3157 match = is_ipv6 && 3158 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 3159 &((ipfw_insn_ip6 *)cmd)->addr6); 3160 break; 3161 case O_IP6_SRC_MASK: 3162 case O_IP6_DST_MASK: 3163 if (is_ipv6) { 3164 int i = cmdlen - 1; 3165 struct in6_addr p; 3166 struct in6_addr *d = 3167 &((ipfw_insn_ip6 *)cmd)->addr6; 3168 3169 for (; !match && i > 0; d += 2, 3170 i -= F_INSN_SIZE(struct in6_addr) 3171 * 2) { 3172 p = (cmd->opcode == 3173 O_IP6_SRC_MASK) ? 3174 args->f_id.src_ip6: 3175 args->f_id.dst_ip6; 3176 APPLY_MASK(&p, &d[1]); 3177 match = 3178 IN6_ARE_ADDR_EQUAL(&d[0], 3179 &p); 3180 } 3181 } 3182 break; 3183 3184 case O_IP6_SRC_ME: 3185 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6); 3186 break; 3187 3188 case O_IP6_DST_ME: 3189 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6); 3190 break; 3191 3192 case O_FLOW6ID: 3193 match = is_ipv6 && 3194 flow6id_match(args->f_id.flow_id6, 3195 (ipfw_insn_u32 *) cmd); 3196 break; 3197 3198 case O_EXT_HDR: 3199 match = is_ipv6 && 3200 (ext_hd & ((ipfw_insn *) cmd)->arg1); 3201 break; 3202 3203 case O_IP6: 3204 match = is_ipv6; 3205 break; 3206#endif 3207 3208 case O_IP4: 3209 match = is_ipv4; 3210 break; 3211 3212 case O_TAG: { 3213 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ? 3214 tablearg : cmd->arg1; 3215 3216 /* Packet is already tagged with this tag? */ 3217 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 3218 3219 /* We have `untag' action when F_NOT flag is 3220 * present. And we must remove this mtag from 3221 * mbuf and reset `match' to zero (`match' will 3222 * be inversed later). 3223 * Otherwise we should allocate new mtag and 3224 * push it into mbuf. 3225 */ 3226 if (cmd->len & F_NOT) { /* `untag' action */ 3227 if (mtag != NULL) 3228 m_tag_delete(m, mtag); 3229 } else if (mtag == NULL) { 3230 if ((mtag = m_tag_alloc(MTAG_IPFW, 3231 tag, 0, M_NOWAIT)) != NULL) 3232 m_tag_prepend(m, mtag); 3233 } 3234 match = (cmd->len & F_NOT) ? 0: 1; 3235 break; 3236 } 3237 3238 case O_TAGGED: { 3239 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ? 3240 tablearg : cmd->arg1; 3241 3242 if (cmdlen == 1) { 3243 match = m_tag_locate(m, MTAG_IPFW, 3244 tag, NULL) != NULL; 3245 break; 3246 } 3247 3248 /* we have ranges */ 3249 for (mtag = m_tag_first(m); 3250 mtag != NULL && !match; 3251 mtag = m_tag_next(m, mtag)) { 3252 uint16_t *p; 3253 int i; 3254 3255 if (mtag->m_tag_cookie != MTAG_IPFW) 3256 continue; 3257 3258 p = ((ipfw_insn_u16 *)cmd)->ports; 3259 i = cmdlen - 1; 3260 for(; !match && i > 0; i--, p += 2) 3261 match = 3262 mtag->m_tag_id >= p[0] && 3263 mtag->m_tag_id <= p[1]; 3264 } 3265 break; 3266 } 3267 3268 /* 3269 * The second set of opcodes represents 'actions', 3270 * i.e. the terminal part of a rule once the packet 3271 * matches all previous patterns. 3272 * Typically there is only one action for each rule, 3273 * and the opcode is stored at the end of the rule 3274 * (but there are exceptions -- see below). 3275 * 3276 * In general, here we set retval and terminate the 3277 * outer loop (would be a 'break 3' in some language, 3278 * but we need to do a 'goto done'). 3279 * 3280 * Exceptions: 3281 * O_COUNT and O_SKIPTO actions: 3282 * instead of terminating, we jump to the next rule 3283 * ('goto next_rule', equivalent to a 'break 2'), 3284 * or to the SKIPTO target ('goto again' after 3285 * having set f, cmd and l), respectively. 3286 * 3287 * O_TAG, O_LOG and O_ALTQ action parameters: 3288 * perform some action and set match = 1; 3289 * 3290 * O_LIMIT and O_KEEP_STATE: these opcodes are 3291 * not real 'actions', and are stored right 3292 * before the 'action' part of the rule. 3293 * These opcodes try to install an entry in the 3294 * state tables; if successful, we continue with 3295 * the next opcode (match=1; break;), otherwise 3296 * the packet * must be dropped 3297 * ('goto done' after setting retval); 3298 * 3299 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 3300 * cause a lookup of the state table, and a jump 3301 * to the 'action' part of the parent rule 3302 * ('goto check_body') if an entry is found, or 3303 * (CHECK_STATE only) a jump to the next rule if 3304 * the entry is not found ('goto next_rule'). 3305 * The result of the lookup is cached to make 3306 * further instances of these opcodes are 3307 * effectively NOPs. 3308 */ 3309 case O_LIMIT: 3310 case O_KEEP_STATE: 3311 if (install_state(f, 3312 (ipfw_insn_limit *)cmd, args, tablearg)) { 3313 retval = IP_FW_DENY; 3314 goto done; /* error/limit violation */ 3315 } 3316 match = 1; 3317 break; 3318 3319 case O_PROBE_STATE: 3320 case O_CHECK_STATE: 3321 /* 3322 * dynamic rules are checked at the first 3323 * keep-state or check-state occurrence, 3324 * with the result being stored in dyn_dir. 3325 * The compiler introduces a PROBE_STATE 3326 * instruction for us when we have a 3327 * KEEP_STATE (because PROBE_STATE needs 3328 * to be run first). 3329 */ 3330 if (dyn_dir == MATCH_UNKNOWN && 3331 (q = lookup_dyn_rule(&args->f_id, 3332 &dyn_dir, proto == IPPROTO_TCP ? 3333 TCP(ulp) : NULL)) 3334 != NULL) { 3335 /* 3336 * Found dynamic entry, update stats 3337 * and jump to the 'action' part of 3338 * the parent rule. 3339 */ 3340 q->pcnt++; 3341 q->bcnt += pktlen; 3342 f = q->rule; 3343 cmd = ACTION_PTR(f); 3344 l = f->cmd_len - f->act_ofs; 3345 IPFW_DYN_UNLOCK(); 3346 goto check_body; 3347 } 3348 /* 3349 * Dynamic entry not found. If CHECK_STATE, 3350 * skip to next rule, if PROBE_STATE just 3351 * ignore and continue with next opcode. 3352 */ 3353 if (cmd->opcode == O_CHECK_STATE) 3354 goto next_rule; 3355 match = 1; 3356 break; 3357 3358 case O_ACCEPT: 3359 retval = 0; /* accept */ 3360 goto done; 3361 3362 case O_PIPE: 3363 case O_QUEUE: 3364 args->rule = f; /* report matching rule */ 3365 if (cmd->arg1 == IP_FW_TABLEARG) 3366 args->cookie = tablearg; 3367 else 3368 args->cookie = cmd->arg1; 3369 retval = IP_FW_DUMMYNET; 3370 goto done; 3371 3372 case O_DIVERT: 3373 case O_TEE: { 3374 struct divert_tag *dt; 3375 3376 if (args->eh) /* not on layer 2 */ 3377 break; 3378 mtag = m_tag_get(PACKET_TAG_DIVERT, 3379 sizeof(struct divert_tag), 3380 M_NOWAIT); 3381 if (mtag == NULL) { 3382 /* XXX statistic */ 3383 /* drop packet */ 3384 IPFW_RUNLOCK(chain); 3385 return (IP_FW_DENY); 3386 } 3387 dt = (struct divert_tag *)(mtag+1); 3388 dt->cookie = f->rulenum; 3389 if (cmd->arg1 == IP_FW_TABLEARG) 3390 dt->info = tablearg; 3391 else 3392 dt->info = cmd->arg1; 3393 m_tag_prepend(m, mtag); 3394 retval = (cmd->opcode == O_DIVERT) ? 3395 IP_FW_DIVERT : IP_FW_TEE; 3396 goto done; 3397 } 3398 3399 case O_COUNT: 3400 case O_SKIPTO: 3401 f->pcnt++; /* update stats */ 3402 f->bcnt += pktlen; 3403 f->timestamp = time_uptime; 3404 if (cmd->opcode == O_COUNT) 3405 goto next_rule; 3406 /* handle skipto */ 3407 if (f->next_rule == NULL) 3408 lookup_next_rule(f); 3409 f = f->next_rule; 3410 goto again; 3411 3412 case O_REJECT: 3413 /* 3414 * Drop the packet and send a reject notice 3415 * if the packet is not ICMP (or is an ICMP 3416 * query), and it is not multicast/broadcast. 3417 */ 3418 if (hlen > 0 && is_ipv4 && offset == 0 && 3419 (proto != IPPROTO_ICMP || 3420 is_icmp_query(ICMP(ulp))) && 3421 !(m->m_flags & (M_BCAST|M_MCAST)) && 3422 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 3423 send_reject(args, cmd->arg1, ip_len, ip); 3424 m = args->m; 3425 } 3426 /* FALLTHROUGH */ 3427#ifdef INET6 3428 case O_UNREACH6: 3429 if (hlen > 0 && is_ipv6 && 3430 ((offset & IP6F_OFF_MASK) == 0) && 3431 (proto != IPPROTO_ICMPV6 || 3432 (is_icmp6_query(args->f_id.flags) == 1)) && 3433 !(m->m_flags & (M_BCAST|M_MCAST)) && 3434 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 3435 send_reject6( 3436 args, cmd->arg1, hlen, 3437 (struct ip6_hdr *)ip); 3438 m = args->m; 3439 } 3440 /* FALLTHROUGH */ 3441#endif 3442 case O_DENY: 3443 retval = IP_FW_DENY; 3444 goto done; 3445 3446 case O_FORWARD_IP: { 3447 struct sockaddr_in *sa; 3448 sa = &(((ipfw_insn_sa *)cmd)->sa); 3449 if (args->eh) /* not valid on layer2 pkts */ 3450 break; 3451 if (!q || dyn_dir == MATCH_FORWARD) { 3452 if (sa->sin_addr.s_addr == INADDR_ANY) { 3453 bcopy(sa, &args->hopstore, 3454 sizeof(*sa)); 3455 args->hopstore.sin_addr.s_addr = 3456 htonl(tablearg); 3457 args->next_hop = 3458 &args->hopstore; 3459 } else { 3460 args->next_hop = sa; 3461 } 3462 } 3463 retval = IP_FW_PASS; 3464 } 3465 goto done; 3466 3467 case O_NETGRAPH: 3468 case O_NGTEE: 3469 args->rule = f; /* report matching rule */ 3470 if (cmd->arg1 == IP_FW_TABLEARG) 3471 args->cookie = tablearg; 3472 else 3473 args->cookie = cmd->arg1; 3474 retval = (cmd->opcode == O_NETGRAPH) ? 3475 IP_FW_NETGRAPH : IP_FW_NGTEE; 3476 goto done; 3477 3478#ifdef IPFIREWALL_NAT 3479 case O_NAT: { 3480 struct cfg_nat *t; 3481 struct mbuf *mcl; 3482 /* XXX - libalias duct tape */ 3483 int ldt; 3484 char *c; 3485 3486 ldt = 0; 3487 args->rule = f; /* Report matching rule. */ 3488 retval = 0; 3489 t = ((ipfw_insn_nat *)cmd)->nat; 3490 if (t == NULL) { 3491 t = lookup_nat(cmd->arg1); 3492 if (t == NULL) { 3493 retval = IP_FW_DENY; 3494 goto done; 3495 } else 3496 ((ipfw_insn_nat *)cmd)->nat = 3497 t; 3498 } 3499 if ((mcl = m_megapullup(m, m->m_pkthdr.len)) == 3500 NULL) 3501 goto badnat; 3502 ip = mtod(mcl, struct ip *); 3503 if (args->eh == NULL) { 3504 ip->ip_len = htons(ip->ip_len); 3505 ip->ip_off = htons(ip->ip_off); 3506 } 3507 3508 /* 3509 * XXX - Libalias checksum offload 'duct tape': 3510 * 3511 * locally generated packets have only 3512 * pseudo-header checksum calculated 3513 * and libalias will screw it[1], so 3514 * mark them for later fix. Moreover 3515 * there are cases when libalias 3516 * modify tcp packet data[2], mark it 3517 * for later fix too. 3518 * 3519 * [1] libalias was never meant to run 3520 * in kernel, so it doesn't have any 3521 * knowledge about checksum 3522 * offloading, and it expects a packet 3523 * with a full internet 3524 * checksum. Unfortunately, packets 3525 * generated locally will have just the 3526 * pseudo header calculated, and when 3527 * libalias tries to adjust the 3528 * checksum it will actually screw it. 3529 * 3530 * [2] when libalias modify tcp's data 3531 * content, full TCP checksum has to 3532 * be recomputed: the problem is that 3533 * libalias doesn't have any idea 3534 * about checksum offloading To 3535 * workaround this, we do not do 3536 * checksumming in LibAlias, but only 3537 * mark the packets in th_x2 field. If 3538 * we receive a marked packet, we 3539 * calculate correct checksum for it 3540 * aware of offloading. Why such a 3541 * terrible hack instead of 3542 * recalculating checksum for each 3543 * packet? Because the previous 3544 * checksum was not checked! 3545 * Recalculating checksums for EVERY 3546 * packet will hide ALL transmission 3547 * errors. Yes, marked packets still 3548 * suffer from this problem. But, 3549 * sigh, natd(8) has this problem, 3550 * too. 3551 * 3552 * TODO: -make libalias mbuf aware (so 3553 * it can handle delayed checksum and tso) 3554 */ 3555 3556 if (mcl->m_pkthdr.rcvif == NULL && 3557 mcl->m_pkthdr.csum_flags & 3558 CSUM_DELAY_DATA) 3559 ldt = 1; 3560 3561 c = mtod(mcl, char *); 3562 if (oif == NULL) 3563 retval = LibAliasIn(t->lib, c, 3564 MCLBYTES); 3565 else 3566 retval = LibAliasOut(t->lib, c, 3567 MCLBYTES); 3568 if (retval != PKT_ALIAS_OK) { 3569 /* XXX - should i add some logging? */ 3570 m_free(mcl); 3571 badnat: 3572 args->m = NULL; 3573 retval = IP_FW_DENY; 3574 goto done; 3575 } 3576 mcl->m_pkthdr.len = mcl->m_len = 3577 ntohs(ip->ip_len); 3578 3579 /* 3580 * XXX - libalias checksum offload 3581 * 'duct tape' (see above) 3582 */ 3583 3584 if ((ip->ip_off & htons(IP_OFFMASK)) == 0 && 3585 ip->ip_p == IPPROTO_TCP) { 3586 struct tcphdr *th; 3587 3588 th = (struct tcphdr *)(ip + 1); 3589 if (th->th_x2) 3590 ldt = 1; 3591 } 3592 3593 if (ldt) { 3594 struct tcphdr *th; 3595 struct udphdr *uh; 3596 u_short cksum; 3597 3598 ip->ip_len = ntohs(ip->ip_len); 3599 cksum = in_pseudo( 3600 ip->ip_src.s_addr, 3601 ip->ip_dst.s_addr, 3602 htons(ip->ip_p + ip->ip_len - 3603 (ip->ip_hl << 2)) 3604 ); 3605 3606 switch (ip->ip_p) { 3607 case IPPROTO_TCP: 3608 th = (struct tcphdr *)(ip + 1); 3609 /* 3610 * Maybe it was set in 3611 * libalias... 3612 */ 3613 th->th_x2 = 0; 3614 th->th_sum = cksum; 3615 mcl->m_pkthdr.csum_data = 3616 offsetof(struct tcphdr, 3617 th_sum); 3618 break; 3619 case IPPROTO_UDP: 3620 uh = (struct udphdr *)(ip + 1); 3621 uh->uh_sum = cksum; 3622 mcl->m_pkthdr.csum_data = 3623 offsetof(struct udphdr, 3624 uh_sum); 3625 break; 3626 } 3627 /* 3628 * No hw checksum offloading: do it 3629 * by ourself. 3630 */ 3631 if ((mcl->m_pkthdr.csum_flags & 3632 CSUM_DELAY_DATA) == 0) { 3633 in_delayed_cksum(mcl); 3634 mcl->m_pkthdr.csum_flags &= 3635 ~CSUM_DELAY_DATA; 3636 } 3637 ip->ip_len = htons(ip->ip_len); 3638 } 3639 3640 if (args->eh == NULL) { 3641 ip->ip_len = ntohs(ip->ip_len); 3642 ip->ip_off = ntohs(ip->ip_off); 3643 } 3644 3645 args->m = mcl; 3646 retval = IP_FW_NAT; 3647 goto done; 3648 } 3649#endif 3650 3651 default: 3652 panic("-- unknown opcode %d\n", cmd->opcode); 3653 } /* end of switch() on opcodes */ 3654 3655 if (cmd->len & F_NOT) 3656 match = !match; 3657 3658 if (match) { 3659 if (cmd->len & F_OR) 3660 skip_or = 1; 3661 } else { 3662 if (!(cmd->len & F_OR)) /* not an OR block, */ 3663 break; /* try next rule */ 3664 } 3665 3666 } /* end of inner for, scan opcodes */ 3667 3668next_rule:; /* try next rule */ 3669 3670 } /* end of outer for, scan rules */ 3671 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 3672 IPFW_RUNLOCK(chain); 3673 return (IP_FW_DENY); 3674 3675done: 3676 /* Update statistics */ 3677 f->pcnt++; 3678 f->bcnt += pktlen; 3679 f->timestamp = time_uptime; 3680 IPFW_RUNLOCK(chain); 3681 return (retval); 3682 3683pullup_failed: 3684 if (fw_verbose) 3685 printf("ipfw: pullup failed\n"); 3686 return (IP_FW_DENY); 3687} 3688 3689/* 3690 * When a rule is added/deleted, clear the next_rule pointers in all rules. 3691 * These will be reconstructed on the fly as packets are matched. 3692 */ 3693static void 3694flush_rule_ptrs(struct ip_fw_chain *chain) 3695{ 3696 struct ip_fw *rule; 3697 3698 IPFW_WLOCK_ASSERT(chain); 3699 3700 for (rule = chain->rules; rule; rule = rule->next) 3701 rule->next_rule = NULL; 3702} 3703 3704/* 3705 * Add a new rule to the list. Copy the rule into a malloc'ed area, then 3706 * possibly create a rule number and add the rule to the list. 3707 * Update the rule_number in the input struct so the caller knows it as well. 3708 */ 3709static int 3710add_rule(struct ip_fw_chain *chain, struct ip_fw *input_rule) 3711{ 3712 struct ip_fw *rule, *f, *prev; 3713 int l = RULESIZE(input_rule); 3714 3715 if (chain->rules == NULL && input_rule->rulenum != IPFW_DEFAULT_RULE) 3716 return (EINVAL); 3717 3718 rule = malloc(l, M_IPFW, M_NOWAIT | M_ZERO); 3719 if (rule == NULL) 3720 return (ENOSPC); 3721 3722 bcopy(input_rule, rule, l); 3723 3724 rule->next = NULL; 3725 rule->next_rule = NULL; 3726 3727 rule->pcnt = 0; 3728 rule->bcnt = 0; 3729 rule->timestamp = 0; 3730 3731 IPFW_WLOCK(chain); 3732 3733 if (chain->rules == NULL) { /* default rule */ 3734 chain->rules = rule; 3735 goto done; 3736 } 3737 3738 /* 3739 * If rulenum is 0, find highest numbered rule before the 3740 * default rule, and add autoinc_step 3741 */ 3742 if (autoinc_step < 1) 3743 autoinc_step = 1; 3744 else if (autoinc_step > 1000) 3745 autoinc_step = 1000; 3746 if (rule->rulenum == 0) { 3747 /* 3748 * locate the highest numbered rule before default 3749 */ 3750 for (f = chain->rules; f; f = f->next) { 3751 if (f->rulenum == IPFW_DEFAULT_RULE) 3752 break; 3753 rule->rulenum = f->rulenum; 3754 } 3755 if (rule->rulenum < IPFW_DEFAULT_RULE - autoinc_step) 3756 rule->rulenum += autoinc_step; 3757 input_rule->rulenum = rule->rulenum; 3758 } 3759 3760 /* 3761 * Now insert the new rule in the right place in the sorted list. 3762 */ 3763 for (prev = NULL, f = chain->rules; f; prev = f, f = f->next) { 3764 if (f->rulenum > rule->rulenum) { /* found the location */ 3765 if (prev) { 3766 rule->next = f; 3767 prev->next = rule; 3768 } else { /* head insert */ 3769 rule->next = chain->rules; 3770 chain->rules = rule; 3771 } 3772 break; 3773 } 3774 } 3775 flush_rule_ptrs(chain); 3776done: 3777 static_count++; 3778 static_len += l; 3779 IPFW_WUNLOCK(chain); 3780 DEB(printf("ipfw: installed rule %d, static count now %d\n", 3781 rule->rulenum, static_count);) 3782 return (0); 3783} 3784 3785/** 3786 * Remove a static rule (including derived * dynamic rules) 3787 * and place it on the ``reap list'' for later reclamation. 3788 * The caller is in charge of clearing rule pointers to avoid 3789 * dangling pointers. 3790 * @return a pointer to the next entry. 3791 * Arguments are not checked, so they better be correct. 3792 */ 3793static struct ip_fw * 3794remove_rule(struct ip_fw_chain *chain, struct ip_fw *rule, 3795 struct ip_fw *prev) 3796{ 3797 struct ip_fw *n; 3798 int l = RULESIZE(rule); 3799 3800 IPFW_WLOCK_ASSERT(chain); 3801 3802 n = rule->next; 3803 IPFW_DYN_LOCK(); 3804 remove_dyn_rule(rule, NULL /* force removal */); 3805 IPFW_DYN_UNLOCK(); 3806 if (prev == NULL) 3807 chain->rules = n; 3808 else 3809 prev->next = n; 3810 static_count--; 3811 static_len -= l; 3812 3813 rule->next = chain->reap; 3814 chain->reap = rule; 3815 3816 return n; 3817} 3818 3819/** 3820 * Reclaim storage associated with a list of rules. This is 3821 * typically the list created using remove_rule. 3822 */ 3823static void 3824reap_rules(struct ip_fw *head) 3825{ 3826 struct ip_fw *rule; 3827 3828 while ((rule = head) != NULL) { 3829 head = head->next; 3830 if (DUMMYNET_LOADED) 3831 ip_dn_ruledel_ptr(rule); 3832 free(rule, M_IPFW); 3833 } 3834} 3835 3836/* 3837 * Remove all rules from a chain (except rules in set RESVD_SET 3838 * unless kill_default = 1). The caller is responsible for 3839 * reclaiming storage for the rules left in chain->reap. 3840 */ 3841static void 3842free_chain(struct ip_fw_chain *chain, int kill_default) 3843{ 3844 struct ip_fw *prev, *rule; 3845 3846 IPFW_WLOCK_ASSERT(chain); 3847 3848 flush_rule_ptrs(chain); /* more efficient to do outside the loop */ 3849 for (prev = NULL, rule = chain->rules; rule ; ) 3850 if (kill_default || rule->set != RESVD_SET) 3851 rule = remove_rule(chain, rule, prev); 3852 else { 3853 prev = rule; 3854 rule = rule->next; 3855 } 3856} 3857 3858/** 3859 * Remove all rules with given number, and also do set manipulation. 3860 * Assumes chain != NULL && *chain != NULL. 3861 * 3862 * The argument is an u_int32_t. The low 16 bit are the rule or set number, 3863 * the next 8 bits are the new set, the top 8 bits are the command: 3864 * 3865 * 0 delete rules with given number 3866 * 1 delete rules with given set number 3867 * 2 move rules with given number to new set 3868 * 3 move rules with given set number to new set 3869 * 4 swap sets with given numbers 3870 * 5 delete rules with given number and with given set number 3871 */ 3872static int 3873del_entry(struct ip_fw_chain *chain, u_int32_t arg) 3874{ 3875 struct ip_fw *prev = NULL, *rule; 3876 u_int16_t rulenum; /* rule or old_set */ 3877 u_int8_t cmd, new_set; 3878 3879 rulenum = arg & 0xffff; 3880 cmd = (arg >> 24) & 0xff; 3881 new_set = (arg >> 16) & 0xff; 3882 3883 if (cmd > 5 || new_set > RESVD_SET) 3884 return EINVAL; 3885 if (cmd == 0 || cmd == 2 || cmd == 5) { 3886 if (rulenum >= IPFW_DEFAULT_RULE) 3887 return EINVAL; 3888 } else { 3889 if (rulenum > RESVD_SET) /* old_set */ 3890 return EINVAL; 3891 } 3892 3893 IPFW_WLOCK(chain); 3894 rule = chain->rules; 3895 chain->reap = NULL; 3896 switch (cmd) { 3897 case 0: /* delete rules with given number */ 3898 /* 3899 * locate first rule to delete 3900 */ 3901 for (; rule->rulenum < rulenum; prev = rule, rule = rule->next) 3902 ; 3903 if (rule->rulenum != rulenum) { 3904 IPFW_WUNLOCK(chain); 3905 return EINVAL; 3906 } 3907 3908 /* 3909 * flush pointers outside the loop, then delete all matching 3910 * rules. prev remains the same throughout the cycle. 3911 */ 3912 flush_rule_ptrs(chain); 3913 while (rule->rulenum == rulenum) 3914 rule = remove_rule(chain, rule, prev); 3915 break; 3916 3917 case 1: /* delete all rules with given set number */ 3918 flush_rule_ptrs(chain); 3919 rule = chain->rules; 3920 while (rule->rulenum < IPFW_DEFAULT_RULE) 3921 if (rule->set == rulenum) 3922 rule = remove_rule(chain, rule, prev); 3923 else { 3924 prev = rule; 3925 rule = rule->next; 3926 } 3927 break; 3928 3929 case 2: /* move rules with given number to new set */ 3930 rule = chain->rules; 3931 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3932 if (rule->rulenum == rulenum) 3933 rule->set = new_set; 3934 break; 3935 3936 case 3: /* move rules with given set number to new set */ 3937 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3938 if (rule->set == rulenum) 3939 rule->set = new_set; 3940 break; 3941 3942 case 4: /* swap two sets */ 3943 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next) 3944 if (rule->set == rulenum) 3945 rule->set = new_set; 3946 else if (rule->set == new_set) 3947 rule->set = rulenum; 3948 break; 3949 case 5: /* delete rules with given number and with given set number. 3950 * rulenum - given rule number; 3951 * new_set - given set number. 3952 */ 3953 for (; rule->rulenum < rulenum; prev = rule, rule = rule->next) 3954 ; 3955 if (rule->rulenum != rulenum) { 3956 IPFW_WUNLOCK(chain); 3957 return (EINVAL); 3958 } 3959 flush_rule_ptrs(chain); 3960 while (rule->rulenum == rulenum) { 3961 if (rule->set == new_set) 3962 rule = remove_rule(chain, rule, prev); 3963 else { 3964 prev = rule; 3965 rule = rule->next; 3966 } 3967 } 3968 } 3969 /* 3970 * Look for rules to reclaim. We grab the list before 3971 * releasing the lock then reclaim them w/o the lock to 3972 * avoid a LOR with dummynet. 3973 */ 3974 rule = chain->reap; 3975 chain->reap = NULL; 3976 IPFW_WUNLOCK(chain); 3977 if (rule) 3978 reap_rules(rule); 3979 return 0; 3980} 3981 3982/* 3983 * Clear counters for a specific rule. 3984 * The enclosing "table" is assumed locked. 3985 */ 3986static void 3987clear_counters(struct ip_fw *rule, int log_only) 3988{ 3989 ipfw_insn_log *l = (ipfw_insn_log *)ACTION_PTR(rule); 3990 3991 if (log_only == 0) { 3992 rule->bcnt = rule->pcnt = 0; 3993 rule->timestamp = 0; 3994 } 3995 if (l->o.opcode == O_LOG) 3996 l->log_left = l->max_log; 3997} 3998 3999/** 4000 * Reset some or all counters on firewall rules. 4001 * The argument `arg' is an u_int32_t. The low 16 bit are the rule number, 4002 * the next 8 bits are the set number, the top 8 bits are the command: 4003 * 0 work with rules from all set's; 4004 * 1 work with rules only from specified set. 4005 * Specified rule number is zero if we want to clear all entries. 4006 * log_only is 1 if we only want to reset logs, zero otherwise. 4007 */ 4008static int 4009zero_entry(struct ip_fw_chain *chain, u_int32_t arg, int log_only) 4010{ 4011 struct ip_fw *rule; 4012 char *msg; 4013 4014 uint16_t rulenum = arg & 0xffff; 4015 uint8_t set = (arg >> 16) & 0xff; 4016 uint8_t cmd = (arg >> 24) & 0xff; 4017 4018 if (cmd > 1) 4019 return (EINVAL); 4020 if (cmd == 1 && set > RESVD_SET) 4021 return (EINVAL); 4022 4023 IPFW_WLOCK(chain); 4024 if (rulenum == 0) { 4025 norule_counter = 0; 4026 for (rule = chain->rules; rule; rule = rule->next) { 4027 /* Skip rules from another set. */ 4028 if (cmd == 1 && rule->set != set) 4029 continue; 4030 clear_counters(rule, log_only); 4031 } 4032 msg = log_only ? "ipfw: All logging counts reset.\n" : 4033 "ipfw: Accounting cleared.\n"; 4034 } else { 4035 int cleared = 0; 4036 /* 4037 * We can have multiple rules with the same number, so we 4038 * need to clear them all. 4039 */ 4040 for (rule = chain->rules; rule; rule = rule->next) 4041 if (rule->rulenum == rulenum) { 4042 while (rule && rule->rulenum == rulenum) { 4043 if (cmd == 0 || rule->set == set) 4044 clear_counters(rule, log_only); 4045 rule = rule->next; 4046 } 4047 cleared = 1; 4048 break; 4049 } 4050 if (!cleared) { /* we did not find any matching rules */ 4051 IPFW_WUNLOCK(chain); 4052 return (EINVAL); 4053 } 4054 msg = log_only ? "ipfw: Entry %d logging count reset.\n" : 4055 "ipfw: Entry %d cleared.\n"; 4056 } 4057 IPFW_WUNLOCK(chain); 4058 4059 if (fw_verbose) 4060 log(LOG_SECURITY | LOG_NOTICE, msg, rulenum); 4061 return (0); 4062} 4063 4064/* 4065 * Check validity of the structure before insert. 4066 * Fortunately rules are simple, so this mostly need to check rule sizes. 4067 */ 4068static int 4069check_ipfw_struct(struct ip_fw *rule, int size) 4070{ 4071 int l, cmdlen = 0; 4072 int have_action=0; 4073 ipfw_insn *cmd; 4074 4075 if (size < sizeof(*rule)) { 4076 printf("ipfw: rule too short\n"); 4077 return (EINVAL); 4078 } 4079 /* first, check for valid size */ 4080 l = RULESIZE(rule); 4081 if (l != size) { 4082 printf("ipfw: size mismatch (have %d want %d)\n", size, l); 4083 return (EINVAL); 4084 } 4085 if (rule->act_ofs >= rule->cmd_len) { 4086 printf("ipfw: bogus action offset (%u > %u)\n", 4087 rule->act_ofs, rule->cmd_len - 1); 4088 return (EINVAL); 4089 } 4090 /* 4091 * Now go for the individual checks. Very simple ones, basically only 4092 * instruction sizes. 4093 */ 4094 for (l = rule->cmd_len, cmd = rule->cmd ; 4095 l > 0 ; l -= cmdlen, cmd += cmdlen) { 4096 cmdlen = F_LEN(cmd); 4097 if (cmdlen > l) { 4098 printf("ipfw: opcode %d size truncated\n", 4099 cmd->opcode); 4100 return EINVAL; 4101 } 4102 DEB(printf("ipfw: opcode %d\n", cmd->opcode);) 4103 switch (cmd->opcode) { 4104 case O_PROBE_STATE: 4105 case O_KEEP_STATE: 4106 case O_PROTO: 4107 case O_IP_SRC_ME: 4108 case O_IP_DST_ME: 4109 case O_LAYER2: 4110 case O_IN: 4111 case O_FRAG: 4112 case O_DIVERTED: 4113 case O_IPOPT: 4114 case O_IPTOS: 4115 case O_IPPRECEDENCE: 4116 case O_IPVER: 4117 case O_TCPWIN: 4118 case O_TCPFLAGS: 4119 case O_TCPOPTS: 4120 case O_ESTAB: 4121 case O_VERREVPATH: 4122 case O_VERSRCREACH: 4123 case O_ANTISPOOF: 4124 case O_IPSEC: 4125#ifdef INET6 4126 case O_IP6_SRC_ME: 4127 case O_IP6_DST_ME: 4128 case O_EXT_HDR: 4129 case O_IP6: 4130#endif 4131 case O_IP4: 4132 case O_TAG: 4133 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 4134 goto bad_size; 4135 break; 4136 4137 case O_UID: 4138 case O_GID: 4139 case O_JAIL: 4140 case O_IP_SRC: 4141 case O_IP_DST: 4142 case O_TCPSEQ: 4143 case O_TCPACK: 4144 case O_PROB: 4145 case O_ICMPTYPE: 4146 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32)) 4147 goto bad_size; 4148 break; 4149 4150 case O_LIMIT: 4151 if (cmdlen != F_INSN_SIZE(ipfw_insn_limit)) 4152 goto bad_size; 4153 break; 4154 4155 case O_LOG: 4156 if (cmdlen != F_INSN_SIZE(ipfw_insn_log)) 4157 goto bad_size; 4158 4159 ((ipfw_insn_log *)cmd)->log_left = 4160 ((ipfw_insn_log *)cmd)->max_log; 4161 4162 break; 4163 4164 case O_IP_SRC_MASK: 4165 case O_IP_DST_MASK: 4166 /* only odd command lengths */ 4167 if ( !(cmdlen & 1) || cmdlen > 31) 4168 goto bad_size; 4169 break; 4170 4171 case O_IP_SRC_SET: 4172 case O_IP_DST_SET: 4173 if (cmd->arg1 == 0 || cmd->arg1 > 256) { 4174 printf("ipfw: invalid set size %d\n", 4175 cmd->arg1); 4176 return EINVAL; 4177 } 4178 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) + 4179 (cmd->arg1+31)/32 ) 4180 goto bad_size; 4181 break; 4182 4183 case O_IP_SRC_LOOKUP: 4184 case O_IP_DST_LOOKUP: 4185 if (cmd->arg1 >= IPFW_TABLES_MAX) { 4186 printf("ipfw: invalid table number %d\n", 4187 cmd->arg1); 4188 return (EINVAL); 4189 } 4190 if (cmdlen != F_INSN_SIZE(ipfw_insn) && 4191 cmdlen != F_INSN_SIZE(ipfw_insn_u32)) 4192 goto bad_size; 4193 break; 4194 4195 case O_MACADDR2: 4196 if (cmdlen != F_INSN_SIZE(ipfw_insn_mac)) 4197 goto bad_size; 4198 break; 4199 4200 case O_NOP: 4201 case O_IPID: 4202 case O_IPTTL: 4203 case O_IPLEN: 4204 case O_TCPDATALEN: 4205 case O_TAGGED: 4206 if (cmdlen < 1 || cmdlen > 31) 4207 goto bad_size; 4208 break; 4209 4210 case O_MAC_TYPE: 4211 case O_IP_SRCPORT: 4212 case O_IP_DSTPORT: /* XXX artificial limit, 30 port pairs */ 4213 if (cmdlen < 2 || cmdlen > 31) 4214 goto bad_size; 4215 break; 4216 4217 case O_RECV: 4218 case O_XMIT: 4219 case O_VIA: 4220 if (cmdlen != F_INSN_SIZE(ipfw_insn_if)) 4221 goto bad_size; 4222 break; 4223 4224 case O_ALTQ: 4225 if (cmdlen != F_INSN_SIZE(ipfw_insn_altq)) 4226 goto bad_size; 4227 break; 4228 4229 case O_PIPE: 4230 case O_QUEUE: 4231 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 4232 goto bad_size; 4233 goto check_action; 4234 4235 case O_FORWARD_IP: 4236#ifdef IPFIREWALL_FORWARD 4237 if (cmdlen != F_INSN_SIZE(ipfw_insn_sa)) 4238 goto bad_size; 4239 goto check_action; 4240#else 4241 return EINVAL; 4242#endif 4243 4244 case O_DIVERT: 4245 case O_TEE: 4246 if (ip_divert_ptr == NULL) 4247 return EINVAL; 4248 else 4249 goto check_size; 4250 case O_NETGRAPH: 4251 case O_NGTEE: 4252 if (!NG_IPFW_LOADED) 4253 return EINVAL; 4254 else 4255 goto check_size; 4256 case O_NAT: 4257#ifdef IPFIREWALL_NAT 4258 if (cmdlen != F_INSN_SIZE(ipfw_insn_nat)) 4259 goto bad_size; 4260 goto check_action; 4261#else 4262 return EINVAL; 4263#endif 4264 case O_FORWARD_MAC: /* XXX not implemented yet */ 4265 case O_CHECK_STATE: 4266 case O_COUNT: 4267 case O_ACCEPT: 4268 case O_DENY: 4269 case O_REJECT: 4270#ifdef INET6 4271 case O_UNREACH6: 4272#endif 4273 case O_SKIPTO: 4274check_size: 4275 if (cmdlen != F_INSN_SIZE(ipfw_insn)) 4276 goto bad_size; 4277check_action: 4278 if (have_action) { 4279 printf("ipfw: opcode %d, multiple actions" 4280 " not allowed\n", 4281 cmd->opcode); 4282 return EINVAL; 4283 } 4284 have_action = 1; 4285 if (l != cmdlen) { 4286 printf("ipfw: opcode %d, action must be" 4287 " last opcode\n", 4288 cmd->opcode); 4289 return EINVAL; 4290 } 4291 break; 4292#ifdef INET6 4293 case O_IP6_SRC: 4294 case O_IP6_DST: 4295 if (cmdlen != F_INSN_SIZE(struct in6_addr) + 4296 F_INSN_SIZE(ipfw_insn)) 4297 goto bad_size; 4298 break; 4299 4300 case O_FLOW6ID: 4301 if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) + 4302 ((ipfw_insn_u32 *)cmd)->o.arg1) 4303 goto bad_size; 4304 break; 4305 4306 case O_IP6_SRC_MASK: 4307 case O_IP6_DST_MASK: 4308 if ( !(cmdlen & 1) || cmdlen > 127) 4309 goto bad_size; 4310 break; 4311 case O_ICMP6TYPE: 4312 if( cmdlen != F_INSN_SIZE( ipfw_insn_icmp6 ) ) 4313 goto bad_size; 4314 break; 4315#endif 4316 4317 default: 4318 switch (cmd->opcode) { 4319#ifndef INET6 4320 case O_IP6_SRC_ME: 4321 case O_IP6_DST_ME: 4322 case O_EXT_HDR: 4323 case O_IP6: 4324 case O_UNREACH6: 4325 case O_IP6_SRC: 4326 case O_IP6_DST: 4327 case O_FLOW6ID: 4328 case O_IP6_SRC_MASK: 4329 case O_IP6_DST_MASK: 4330 case O_ICMP6TYPE: 4331 printf("ipfw: no IPv6 support in kernel\n"); 4332 return EPROTONOSUPPORT; 4333#endif 4334 default: 4335 printf("ipfw: opcode %d, unknown opcode\n", 4336 cmd->opcode); 4337 return EINVAL; 4338 } 4339 } 4340 } 4341 if (have_action == 0) { 4342 printf("ipfw: missing action\n"); 4343 return EINVAL; 4344 } 4345 return 0; 4346 4347bad_size: 4348 printf("ipfw: opcode %d size %d wrong\n", 4349 cmd->opcode, cmdlen); 4350 return EINVAL; 4351} 4352 4353/* 4354 * Copy the static and dynamic rules to the supplied buffer 4355 * and return the amount of space actually used. 4356 */ 4357static size_t 4358ipfw_getrules(struct ip_fw_chain *chain, void *buf, size_t space) 4359{ 4360 char *bp = buf; 4361 char *ep = bp + space; 4362 struct ip_fw *rule; 4363 int i; 4364 time_t boot_seconds; 4365 4366 boot_seconds = boottime.tv_sec; 4367 /* XXX this can take a long time and locking will block packet flow */ 4368 IPFW_RLOCK(chain); 4369 for (rule = chain->rules; rule ; rule = rule->next) { 4370 /* 4371 * Verify the entry fits in the buffer in case the 4372 * rules changed between calculating buffer space and 4373 * now. This would be better done using a generation 4374 * number but should suffice for now. 4375 */ 4376 i = RULESIZE(rule); 4377 if (bp + i <= ep) { 4378 bcopy(rule, bp, i); 4379 /* 4380 * XXX HACK. Store the disable mask in the "next" pointer 4381 * in a wild attempt to keep the ABI the same. 4382 * Why do we do this on EVERY rule? 4383 */ 4384 bcopy(&set_disable, &(((struct ip_fw *)bp)->next_rule), 4385 sizeof(set_disable)); 4386 if (((struct ip_fw *)bp)->timestamp) 4387 ((struct ip_fw *)bp)->timestamp += boot_seconds; 4388 bp += i; 4389 } 4390 } 4391 IPFW_RUNLOCK(chain); 4392 if (ipfw_dyn_v) { 4393 ipfw_dyn_rule *p, *last = NULL; 4394 4395 IPFW_DYN_LOCK(); 4396 for (i = 0 ; i < curr_dyn_buckets; i++) 4397 for (p = ipfw_dyn_v[i] ; p != NULL; p = p->next) { 4398 if (bp + sizeof *p <= ep) { 4399 ipfw_dyn_rule *dst = 4400 (ipfw_dyn_rule *)bp; 4401 bcopy(p, dst, sizeof *p); 4402 bcopy(&(p->rule->rulenum), &(dst->rule), 4403 sizeof(p->rule->rulenum)); 4404 /* 4405 * store set number into high word of 4406 * dst->rule pointer. 4407 */ 4408 bcopy(&(p->rule->set), 4409 (char *)&dst->rule + 4410 sizeof(p->rule->rulenum), 4411 sizeof(p->rule->set)); 4412 /* 4413 * store a non-null value in "next". 4414 * The userland code will interpret a 4415 * NULL here as a marker 4416 * for the last dynamic rule. 4417 */ 4418 bcopy(&dst, &dst->next, sizeof(dst)); 4419 last = dst; 4420 dst->expire = 4421 TIME_LEQ(dst->expire, time_uptime) ? 4422 0 : dst->expire - time_uptime ; 4423 bp += sizeof(ipfw_dyn_rule); 4424 } 4425 } 4426 IPFW_DYN_UNLOCK(); 4427 if (last != NULL) /* mark last dynamic rule */ 4428 bzero(&last->next, sizeof(last)); 4429 } 4430 return (bp - (char *)buf); 4431} 4432 4433 4434/** 4435 * {set|get}sockopt parser. 4436 */ 4437static int 4438ipfw_ctl(struct sockopt *sopt) 4439{ 4440#define RULE_MAXSIZE (256*sizeof(u_int32_t)) 4441 int error; 4442 size_t size; 4443 struct ip_fw *buf, *rule; 4444 u_int32_t rulenum[2]; 4445 4446 error = priv_check(sopt->sopt_td, PRIV_NETINET_IPFW); 4447 if (error) 4448 return (error); 4449 4450 /* 4451 * Disallow modifications in really-really secure mode, but still allow 4452 * the logging counters to be reset. 4453 */ 4454 if (sopt->sopt_name == IP_FW_ADD || 4455 (sopt->sopt_dir == SOPT_SET && sopt->sopt_name != IP_FW_RESETLOG)) { 4456 error = securelevel_ge(sopt->sopt_td->td_ucred, 3); 4457 if (error) 4458 return (error); 4459 } 4460 4461 error = 0; 4462 4463 switch (sopt->sopt_name) { 4464 case IP_FW_GET: 4465 /* 4466 * pass up a copy of the current rules. Static rules 4467 * come first (the last of which has number IPFW_DEFAULT_RULE), 4468 * followed by a possibly empty list of dynamic rule. 4469 * The last dynamic rule has NULL in the "next" field. 4470 * 4471 * Note that the calculated size is used to bound the 4472 * amount of data returned to the user. The rule set may 4473 * change between calculating the size and returning the 4474 * data in which case we'll just return what fits. 4475 */ 4476 size = static_len; /* size of static rules */ 4477 if (ipfw_dyn_v) /* add size of dyn.rules */ 4478 size += (dyn_count * sizeof(ipfw_dyn_rule)); 4479 4480 /* 4481 * XXX todo: if the user passes a short length just to know 4482 * how much room is needed, do not bother filling up the 4483 * buffer, just jump to the sooptcopyout. 4484 */ 4485 buf = malloc(size, M_TEMP, M_WAITOK); 4486 error = sooptcopyout(sopt, buf, 4487 ipfw_getrules(&layer3_chain, buf, size)); 4488 free(buf, M_TEMP); 4489 break; 4490 4491 case IP_FW_FLUSH: 4492 /* 4493 * Normally we cannot release the lock on each iteration. 4494 * We could do it here only because we start from the head all 4495 * the times so there is no risk of missing some entries. 4496 * On the other hand, the risk is that we end up with 4497 * a very inconsistent ruleset, so better keep the lock 4498 * around the whole cycle. 4499 * 4500 * XXX this code can be improved by resetting the head of 4501 * the list to point to the default rule, and then freeing 4502 * the old list without the need for a lock. 4503 */ 4504 4505 IPFW_WLOCK(&layer3_chain); 4506 layer3_chain.reap = NULL; 4507 free_chain(&layer3_chain, 0 /* keep default rule */); 4508 rule = layer3_chain.reap; 4509 layer3_chain.reap = NULL; 4510 IPFW_WUNLOCK(&layer3_chain); 4511 if (rule != NULL) 4512 reap_rules(rule); 4513 break; 4514 4515 case IP_FW_ADD: 4516 rule = malloc(RULE_MAXSIZE, M_TEMP, M_WAITOK); 4517 error = sooptcopyin(sopt, rule, RULE_MAXSIZE, 4518 sizeof(struct ip_fw) ); 4519 if (error == 0) 4520 error = check_ipfw_struct(rule, sopt->sopt_valsize); 4521 if (error == 0) { 4522 error = add_rule(&layer3_chain, rule); 4523 size = RULESIZE(rule); 4524 if (!error && sopt->sopt_dir == SOPT_GET) 4525 error = sooptcopyout(sopt, rule, size); 4526 } 4527 free(rule, M_TEMP); 4528 break; 4529 4530 case IP_FW_DEL: 4531 /* 4532 * IP_FW_DEL is used for deleting single rules or sets, 4533 * and (ab)used to atomically manipulate sets. Argument size 4534 * is used to distinguish between the two: 4535 * sizeof(u_int32_t) 4536 * delete single rule or set of rules, 4537 * or reassign rules (or sets) to a different set. 4538 * 2*sizeof(u_int32_t) 4539 * atomic disable/enable sets. 4540 * first u_int32_t contains sets to be disabled, 4541 * second u_int32_t contains sets to be enabled. 4542 */ 4543 error = sooptcopyin(sopt, rulenum, 4544 2*sizeof(u_int32_t), sizeof(u_int32_t)); 4545 if (error) 4546 break; 4547 size = sopt->sopt_valsize; 4548 if (size == sizeof(u_int32_t)) /* delete or reassign */ 4549 error = del_entry(&layer3_chain, rulenum[0]); 4550 else if (size == 2*sizeof(u_int32_t)) /* set enable/disable */ 4551 set_disable = 4552 (set_disable | rulenum[0]) & ~rulenum[1] & 4553 ~(1<<RESVD_SET); /* set RESVD_SET always enabled */ 4554 else 4555 error = EINVAL; 4556 break; 4557 4558 case IP_FW_ZERO: 4559 case IP_FW_RESETLOG: /* argument is an u_int_32, the rule number */ 4560 rulenum[0] = 0; 4561 if (sopt->sopt_val != 0) { 4562 error = sooptcopyin(sopt, rulenum, 4563 sizeof(u_int32_t), sizeof(u_int32_t)); 4564 if (error) 4565 break; 4566 } 4567 error = zero_entry(&layer3_chain, rulenum[0], 4568 sopt->sopt_name == IP_FW_RESETLOG); 4569 break; 4570 4571 case IP_FW_TABLE_ADD: 4572 { 4573 ipfw_table_entry ent; 4574 4575 error = sooptcopyin(sopt, &ent, 4576 sizeof(ent), sizeof(ent)); 4577 if (error) 4578 break; 4579 error = add_table_entry(&layer3_chain, ent.tbl, 4580 ent.addr, ent.masklen, ent.value); 4581 } 4582 break; 4583 4584 case IP_FW_TABLE_DEL: 4585 { 4586 ipfw_table_entry ent; 4587 4588 error = sooptcopyin(sopt, &ent, 4589 sizeof(ent), sizeof(ent)); 4590 if (error) 4591 break; 4592 error = del_table_entry(&layer3_chain, ent.tbl, 4593 ent.addr, ent.masklen); 4594 } 4595 break; 4596 4597 case IP_FW_TABLE_FLUSH: 4598 { 4599 u_int16_t tbl; 4600 4601 error = sooptcopyin(sopt, &tbl, 4602 sizeof(tbl), sizeof(tbl)); 4603 if (error) 4604 break; 4605 IPFW_WLOCK(&layer3_chain); 4606 error = flush_table(&layer3_chain, tbl); 4607 IPFW_WUNLOCK(&layer3_chain); 4608 } 4609 break; 4610 4611 case IP_FW_TABLE_GETSIZE: 4612 { 4613 u_int32_t tbl, cnt; 4614 4615 if ((error = sooptcopyin(sopt, &tbl, sizeof(tbl), 4616 sizeof(tbl)))) 4617 break; 4618 IPFW_RLOCK(&layer3_chain); 4619 error = count_table(&layer3_chain, tbl, &cnt); 4620 IPFW_RUNLOCK(&layer3_chain); 4621 if (error) 4622 break; 4623 error = sooptcopyout(sopt, &cnt, sizeof(cnt)); 4624 } 4625 break; 4626 4627 case IP_FW_TABLE_LIST: 4628 { 4629 ipfw_table *tbl; 4630 4631 if (sopt->sopt_valsize < sizeof(*tbl)) { 4632 error = EINVAL; 4633 break; 4634 } 4635 size = sopt->sopt_valsize; 4636 tbl = malloc(size, M_TEMP, M_WAITOK); 4637 error = sooptcopyin(sopt, tbl, size, sizeof(*tbl)); 4638 if (error) { 4639 free(tbl, M_TEMP); 4640 break; 4641 } 4642 tbl->size = (size - sizeof(*tbl)) / 4643 sizeof(ipfw_table_entry); 4644 IPFW_RLOCK(&layer3_chain); 4645 error = dump_table(&layer3_chain, tbl); 4646 IPFW_RUNLOCK(&layer3_chain); 4647 if (error) { 4648 free(tbl, M_TEMP); 4649 break; 4650 } 4651 error = sooptcopyout(sopt, tbl, size); 4652 free(tbl, M_TEMP); 4653 } 4654 break; 4655 4656#ifdef IPFIREWALL_NAT 4657 case IP_FW_NAT_CFG: 4658 { 4659 struct cfg_nat *ptr, *ser_n; 4660 char *buf; 4661 4662 buf = malloc(NAT_BUF_LEN, M_IPFW, M_WAITOK | M_ZERO); 4663 error = sooptcopyin(sopt, buf, NAT_BUF_LEN, 4664 sizeof(struct cfg_nat)); 4665 ser_n = (struct cfg_nat *)buf; 4666 4667 /* 4668 * Find/create nat rule. 4669 */ 4670 IPFW_WLOCK(&layer3_chain); 4671 ptr = lookup_nat(ser_n->id); 4672 if (ptr == NULL) { 4673 /* New rule: allocate and init new instance. */ 4674 ptr = malloc(sizeof(struct cfg_nat), 4675 M_IPFW, M_NOWAIT | M_ZERO); 4676 if (ptr == NULL) { 4677 IPFW_WUNLOCK(&layer3_chain); 4678 free(buf, M_IPFW); 4679 return (ENOSPC); 4680 } 4681 ptr->lib = LibAliasInit(NULL); 4682 if (ptr->lib == NULL) { 4683 IPFW_WUNLOCK(&layer3_chain); 4684 free(ptr, M_IPFW); 4685 free(buf, M_IPFW); 4686 return (EINVAL); 4687 } 4688 LIST_INIT(&ptr->redir_chain); 4689 } else { 4690 /* Entry already present: temporarly unhook it. */ 4691 UNHOOK_NAT(ptr); 4692 flush_nat_ptrs(ser_n->id); 4693 } 4694 IPFW_WUNLOCK(&layer3_chain); 4695 4696 /* 4697 * Basic nat configuration. 4698 */ 4699 ptr->id = ser_n->id; 4700 /* 4701 * XXX - what if this rule doesn't nat any ip and just 4702 * redirect? 4703 * do we set aliasaddress to 0.0.0.0? 4704 */ 4705 ptr->ip = ser_n->ip; 4706 ptr->redir_cnt = ser_n->redir_cnt; 4707 ptr->mode = ser_n->mode; 4708 LibAliasSetMode(ptr->lib, ser_n->mode, ser_n->mode); 4709 LibAliasSetAddress(ptr->lib, ptr->ip); 4710 memcpy(ptr->if_name, ser_n->if_name, IF_NAMESIZE); 4711 4712 /* 4713 * Redir and LSNAT configuration. 4714 */ 4715 /* Delete old cfgs. */ 4716 del_redir_spool_cfg(ptr, &ptr->redir_chain); 4717 /* Add new entries. */ 4718 add_redir_spool_cfg(&buf[(sizeof(struct cfg_nat))], ptr); 4719 free(buf, M_IPFW); 4720 IPFW_WLOCK(&layer3_chain); 4721 HOOK_NAT(&layer3_chain.nat, ptr); 4722 IPFW_WUNLOCK(&layer3_chain); 4723 } 4724 break; 4725 4726 case IP_FW_NAT_DEL: 4727 { 4728 struct cfg_nat *ptr; 4729 int i; 4730 4731 error = sooptcopyin(sopt, &i, sizeof i, sizeof i); 4732 IPFW_WLOCK(&layer3_chain); 4733 ptr = lookup_nat(i); 4734 if (ptr == NULL) { 4735 error = EINVAL; 4736 IPFW_WUNLOCK(&layer3_chain); 4737 break; 4738 } 4739 UNHOOK_NAT(ptr); 4740 flush_nat_ptrs(i); 4741 IPFW_WUNLOCK(&layer3_chain); 4742 del_redir_spool_cfg(ptr, &ptr->redir_chain); 4743 LibAliasUninit(ptr->lib); 4744 free(ptr, M_IPFW); 4745 } 4746 break; 4747 4748 case IP_FW_NAT_GET_CONFIG: 4749 { 4750 uint8_t *data; 4751 struct cfg_nat *n; 4752 struct cfg_redir *r; 4753 struct cfg_spool *s; 4754 int nat_cnt, off; 4755 4756 nat_cnt = 0; 4757 off = sizeof(nat_cnt); 4758 4759 data = malloc(NAT_BUF_LEN, M_IPFW, M_WAITOK | M_ZERO); 4760 IPFW_RLOCK(&layer3_chain); 4761 /* Serialize all the data. */ 4762 LIST_FOREACH(n, &layer3_chain.nat, _next) { 4763 nat_cnt++; 4764 if (off + SOF_NAT < NAT_BUF_LEN) { 4765 bcopy(n, &data[off], SOF_NAT); 4766 off += SOF_NAT; 4767 LIST_FOREACH(r, &n->redir_chain, _next) { 4768 if (off + SOF_REDIR < NAT_BUF_LEN) { 4769 bcopy(r, &data[off], 4770 SOF_REDIR); 4771 off += SOF_REDIR; 4772 LIST_FOREACH(s, &r->spool_chain, 4773 _next) { 4774 if (off + SOF_SPOOL < 4775 NAT_BUF_LEN) { 4776 bcopy(s, 4777 &data[off], 4778 SOF_SPOOL); 4779 off += 4780 SOF_SPOOL; 4781 } else 4782 goto nospace; 4783 } 4784 } else 4785 goto nospace; 4786 } 4787 } else 4788 goto nospace; 4789 } 4790 bcopy(&nat_cnt, data, sizeof(nat_cnt)); 4791 IPFW_RUNLOCK(&layer3_chain); 4792 error = sooptcopyout(sopt, data, NAT_BUF_LEN); 4793 free(data, M_IPFW); 4794 break; 4795 nospace: 4796 IPFW_RUNLOCK(&layer3_chain); 4797 printf("serialized data buffer not big enough:" 4798 "please increase NAT_BUF_LEN\n"); 4799 free(data, M_IPFW); 4800 } 4801 break; 4802 4803 case IP_FW_NAT_GET_LOG: 4804 { 4805 uint8_t *data; 4806 struct cfg_nat *ptr; 4807 int i, size, cnt, sof; 4808 4809 data = NULL; 4810 sof = LIBALIAS_BUF_SIZE; 4811 cnt = 0; 4812 4813 IPFW_RLOCK(&layer3_chain); 4814 size = i = 0; 4815 LIST_FOREACH(ptr, &layer3_chain.nat, _next) { 4816 if (ptr->lib->logDesc == NULL) 4817 continue; 4818 cnt++; 4819 size = cnt * (sof + sizeof(int)); 4820 data = realloc(data, size, M_IPFW, M_NOWAIT | M_ZERO); 4821 if (data == NULL) { 4822 IPFW_RUNLOCK(&layer3_chain); 4823 return (ENOSPC); 4824 } 4825 bcopy(&ptr->id, &data[i], sizeof(int)); 4826 i += sizeof(int); 4827 bcopy(ptr->lib->logDesc, &data[i], sof); 4828 i += sof; 4829 } 4830 IPFW_RUNLOCK(&layer3_chain); 4831 error = sooptcopyout(sopt, data, size); 4832 free(data, M_IPFW); 4833 } 4834 break; 4835#endif 4836 4837 default: 4838 printf("ipfw: ipfw_ctl invalid option %d\n", sopt->sopt_name); 4839 error = EINVAL; 4840 } 4841 4842 return (error); 4843#undef RULE_MAXSIZE 4844} 4845 4846/** 4847 * dummynet needs a reference to the default rule, because rules can be 4848 * deleted while packets hold a reference to them. When this happens, 4849 * dummynet changes the reference to the default rule (it could well be a 4850 * NULL pointer, but this way we do not need to check for the special 4851 * case, plus here he have info on the default behaviour). 4852 */ 4853struct ip_fw *ip_fw_default_rule; 4854 4855/* 4856 * This procedure is only used to handle keepalives. It is invoked 4857 * every dyn_keepalive_period 4858 */ 4859static void 4860ipfw_tick(void * __unused unused) 4861{ 4862 struct mbuf *m0, *m, *mnext, **mtailp; 4863 int i; 4864 ipfw_dyn_rule *q; 4865 4866 if (dyn_keepalive == 0 || ipfw_dyn_v == NULL || dyn_count == 0) 4867 goto done; 4868 4869 /* 4870 * We make a chain of packets to go out here -- not deferring 4871 * until after we drop the IPFW dynamic rule lock would result 4872 * in a lock order reversal with the normal packet input -> ipfw 4873 * call stack. 4874 */ 4875 m0 = NULL; 4876 mtailp = &m0; 4877 IPFW_DYN_LOCK(); 4878 for (i = 0 ; i < curr_dyn_buckets ; i++) { 4879 for (q = ipfw_dyn_v[i] ; q ; q = q->next ) { 4880 if (q->dyn_type == O_LIMIT_PARENT) 4881 continue; 4882 if (q->id.proto != IPPROTO_TCP) 4883 continue; 4884 if ( (q->state & BOTH_SYN) != BOTH_SYN) 4885 continue; 4886 if (TIME_LEQ( time_uptime+dyn_keepalive_interval, 4887 q->expire)) 4888 continue; /* too early */ 4889 if (TIME_LEQ(q->expire, time_uptime)) 4890 continue; /* too late, rule expired */ 4891 4892 *mtailp = send_pkt(NULL, &(q->id), q->ack_rev - 1, 4893 q->ack_fwd, TH_SYN); 4894 if (*mtailp != NULL) 4895 mtailp = &(*mtailp)->m_nextpkt; 4896 *mtailp = send_pkt(NULL, &(q->id), q->ack_fwd - 1, 4897 q->ack_rev, 0); 4898 if (*mtailp != NULL) 4899 mtailp = &(*mtailp)->m_nextpkt; 4900 } 4901 } 4902 IPFW_DYN_UNLOCK(); 4903 for (m = mnext = m0; m != NULL; m = mnext) { 4904 mnext = m->m_nextpkt; 4905 m->m_nextpkt = NULL; 4906 ip_output(m, NULL, NULL, 0, NULL, NULL); 4907 } 4908done: 4909 callout_reset(&ipfw_timeout, dyn_keepalive_period*hz, ipfw_tick, NULL); 4910} 4911 4912int 4913ipfw_init(void) 4914{ 4915 struct ip_fw default_rule; 4916 int error; 4917 4918#ifdef INET6 4919 /* Setup IPv6 fw sysctl tree. */ 4920 sysctl_ctx_init(&ip6_fw_sysctl_ctx); 4921 ip6_fw_sysctl_tree = SYSCTL_ADD_NODE(&ip6_fw_sysctl_ctx, 4922 SYSCTL_STATIC_CHILDREN(_net_inet6_ip6), OID_AUTO, "fw", 4923 CTLFLAG_RW | CTLFLAG_SECURE, 0, "Firewall"); 4924 SYSCTL_ADD_PROC(&ip6_fw_sysctl_ctx, SYSCTL_CHILDREN(ip6_fw_sysctl_tree), 4925 OID_AUTO, "enable", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3, 4926 &fw6_enable, 0, ipfw_chg_hook, "I", "Enable ipfw+6"); 4927 SYSCTL_ADD_INT(&ip6_fw_sysctl_ctx, SYSCTL_CHILDREN(ip6_fw_sysctl_tree), 4928 OID_AUTO, "deny_unknown_exthdrs", CTLFLAG_RW | CTLFLAG_SECURE, 4929 &fw_deny_unknown_exthdrs, 0, 4930 "Deny packets with unknown IPv6 Extension Headers"); 4931#endif 4932 4933 layer3_chain.rules = NULL; 4934 IPFW_LOCK_INIT(&layer3_chain); 4935 ipfw_dyn_rule_zone = uma_zcreate("IPFW dynamic rule", 4936 sizeof(ipfw_dyn_rule), NULL, NULL, NULL, NULL, 4937 UMA_ALIGN_PTR, 0); 4938 IPFW_DYN_LOCK_INIT(); 4939 callout_init(&ipfw_timeout, CALLOUT_MPSAFE); 4940 4941 bzero(&default_rule, sizeof default_rule); 4942 4943 default_rule.act_ofs = 0; 4944 default_rule.rulenum = IPFW_DEFAULT_RULE; 4945 default_rule.cmd_len = 1; 4946 default_rule.set = RESVD_SET; 4947 4948 default_rule.cmd[0].len = 1; 4949 default_rule.cmd[0].opcode = 4950#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 4951 1 ? O_ACCEPT : 4952#endif 4953 O_DENY; 4954 4955 error = add_rule(&layer3_chain, &default_rule); 4956 if (error != 0) { 4957 printf("ipfw2: error %u initializing default rule " 4958 "(support disabled)\n", error); 4959 IPFW_DYN_LOCK_DESTROY(); 4960 IPFW_LOCK_DESTROY(&layer3_chain); 4961 uma_zdestroy(ipfw_dyn_rule_zone); 4962 return (error); 4963 } 4964 4965 ip_fw_default_rule = layer3_chain.rules; 4966 printf("ipfw2 " 4967#ifdef INET6 4968 "(+ipv6) " 4969#endif 4970 "initialized, divert %s, " 4971 "rule-based forwarding " 4972#ifdef IPFIREWALL_FORWARD 4973 "enabled, " 4974#else 4975 "disabled, " 4976#endif 4977 "default to %s, logging ", 4978#ifdef IPDIVERT 4979 "enabled", 4980#else 4981 "loadable", 4982#endif 4983 default_rule.cmd[0].opcode == O_ACCEPT ? "accept" : "deny"); 4984 4985#ifdef IPFIREWALL_VERBOSE 4986 fw_verbose = 1; 4987#endif 4988#ifdef IPFIREWALL_VERBOSE_LIMIT 4989 verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 4990#endif 4991 if (fw_verbose == 0) 4992 printf("disabled\n"); 4993 else if (verbose_limit == 0) 4994 printf("unlimited\n"); 4995 else 4996 printf("limited to %d packets/entry by default\n", 4997 verbose_limit); 4998 4999 error = init_tables(&layer3_chain); 5000 if (error) { 5001 IPFW_DYN_LOCK_DESTROY(); 5002 IPFW_LOCK_DESTROY(&layer3_chain); 5003 uma_zdestroy(ipfw_dyn_rule_zone); 5004 return (error); 5005 } 5006 ip_fw_ctl_ptr = ipfw_ctl; 5007 ip_fw_chk_ptr = ipfw_chk; 5008 callout_reset(&ipfw_timeout, hz, ipfw_tick, NULL); 5009#ifdef IPFIREWALL_NAT 5010 LIST_INIT(&layer3_chain.nat); 5011 ifaddr_event_tag = EVENTHANDLER_REGISTER(ifaddr_event, ifaddr_change, 5012 NULL, EVENTHANDLER_PRI_ANY); 5013#endif 5014 return (0); 5015} 5016 5017void 5018ipfw_destroy(void) 5019{ 5020 struct ip_fw *reap; 5021#ifdef IPFIREWALL_NAT 5022 struct cfg_nat *ptr, *ptr_temp; 5023#endif 5024 5025 ip_fw_chk_ptr = NULL; 5026 ip_fw_ctl_ptr = NULL; 5027 callout_drain(&ipfw_timeout); 5028 IPFW_WLOCK(&layer3_chain); 5029 flush_tables(&layer3_chain); 5030#ifdef IPFIREWALL_NAT 5031 LIST_FOREACH_SAFE(ptr, &layer3_chain.nat, _next, ptr_temp) { 5032 LIST_REMOVE(ptr, _next); 5033 del_redir_spool_cfg(ptr, &ptr->redir_chain); 5034 LibAliasUninit(ptr->lib); 5035 free(ptr, M_IPFW); 5036 } 5037 EVENTHANDLER_DEREGISTER(ifaddr_event, ifaddr_event_tag); 5038#endif 5039 layer3_chain.reap = NULL; 5040 free_chain(&layer3_chain, 1 /* kill default rule */); 5041 reap = layer3_chain.reap, layer3_chain.reap = NULL; 5042 IPFW_WUNLOCK(&layer3_chain); 5043 if (reap != NULL) 5044 reap_rules(reap); 5045 IPFW_DYN_LOCK_DESTROY(); 5046 uma_zdestroy(ipfw_dyn_rule_zone); 5047 if (ipfw_dyn_v != NULL) 5048 free(ipfw_dyn_v, M_IPFW); 5049 IPFW_LOCK_DESTROY(&layer3_chain); 5050 5051#ifdef INET6 5052 /* Free IPv6 fw sysctl tree. */ 5053 sysctl_ctx_free(&ip6_fw_sysctl_ctx); 5054#endif 5055 5056 printf("IP firewall unloaded\n"); 5057} 5058