ip_fw2.c revision 250762
1/*- 2 * Copyright (c) 2002-2009 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: stable/9/sys/netpfil/ipfw/ip_fw2.c 250762 2013-05-18 05:48:46Z melifaro $"); 28 29/* 30 * The FreeBSD IP packet firewall, main file 31 */ 32 33#include "opt_ipfw.h" 34#include "opt_ipdivert.h" 35#include "opt_inet.h" 36#ifndef INET 37#error IPFIREWALL requires INET. 38#endif /* INET */ 39#include "opt_inet6.h" 40#include "opt_ipsec.h" 41 42#include <sys/param.h> 43#include <sys/systm.h> 44#include <sys/condvar.h> 45#include <sys/eventhandler.h> 46#include <sys/malloc.h> 47#include <sys/mbuf.h> 48#include <sys/kernel.h> 49#include <sys/lock.h> 50#include <sys/jail.h> 51#include <sys/module.h> 52#include <sys/priv.h> 53#include <sys/proc.h> 54#include <sys/rwlock.h> 55#include <sys/socket.h> 56#include <sys/socketvar.h> 57#include <sys/sysctl.h> 58#include <sys/syslog.h> 59#include <sys/ucred.h> 60#include <net/ethernet.h> /* for ETHERTYPE_IP */ 61#include <net/if.h> 62#include <net/route.h> 63#include <net/pf_mtag.h> 64#include <net/pfil.h> 65#include <net/vnet.h> 66 67#include <netinet/in.h> 68#include <netinet/in_var.h> 69#include <netinet/in_pcb.h> 70#include <netinet/ip.h> 71#include <netinet/ip_var.h> 72#include <netinet/ip_icmp.h> 73#include <netinet/ip_fw.h> 74#include <netinet/ip_carp.h> 75#include <netinet/pim.h> 76#include <netinet/tcp_var.h> 77#include <netinet/udp.h> 78#include <netinet/udp_var.h> 79#include <netinet/sctp.h> 80 81#include <netinet/ip6.h> 82#include <netinet/icmp6.h> 83#ifdef INET6 84#include <netinet6/in6_pcb.h> 85#include <netinet6/scope6_var.h> 86#include <netinet6/ip6_var.h> 87#endif 88 89#include <netpfil/ipfw/ip_fw_private.h> 90 91#include <machine/in_cksum.h> /* XXX for in_cksum */ 92 93#ifdef MAC 94#include <security/mac/mac_framework.h> 95#endif 96 97/* 98 * static variables followed by global ones. 99 * All ipfw global variables are here. 100 */ 101 102/* ipfw_vnet_ready controls when we are open for business */ 103static VNET_DEFINE(int, ipfw_vnet_ready) = 0; 104#define V_ipfw_vnet_ready VNET(ipfw_vnet_ready) 105 106static VNET_DEFINE(int, fw_deny_unknown_exthdrs); 107#define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs) 108 109static VNET_DEFINE(int, fw_permit_single_frag6) = 1; 110#define V_fw_permit_single_frag6 VNET(fw_permit_single_frag6) 111 112#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 113static int default_to_accept = 1; 114#else 115static int default_to_accept; 116#endif 117 118VNET_DEFINE(int, autoinc_step); 119VNET_DEFINE(int, fw_one_pass) = 1; 120 121VNET_DEFINE(unsigned int, fw_tables_max); 122/* Use 128 tables by default */ 123static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT; 124 125/* 126 * Each rule belongs to one of 32 different sets (0..31). 127 * The variable set_disable contains one bit per set. 128 * If the bit is set, all rules in the corresponding set 129 * are disabled. Set RESVD_SET(31) is reserved for the default rule 130 * and rules that are not deleted by the flush command, 131 * and CANNOT be disabled. 132 * Rules in set RESVD_SET can only be deleted individually. 133 */ 134VNET_DEFINE(u_int32_t, set_disable); 135#define V_set_disable VNET(set_disable) 136 137VNET_DEFINE(int, fw_verbose); 138/* counter for ipfw_log(NULL...) */ 139VNET_DEFINE(u_int64_t, norule_counter); 140VNET_DEFINE(int, verbose_limit); 141 142/* layer3_chain contains the list of rules for layer 3 */ 143VNET_DEFINE(struct ip_fw_chain, layer3_chain); 144 145ipfw_nat_t *ipfw_nat_ptr = NULL; 146struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int); 147ipfw_nat_cfg_t *ipfw_nat_cfg_ptr; 148ipfw_nat_cfg_t *ipfw_nat_del_ptr; 149ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr; 150ipfw_nat_cfg_t *ipfw_nat_get_log_ptr; 151 152#ifdef SYSCTL_NODE 153uint32_t dummy_def = IPFW_DEFAULT_RULE; 154static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS); 155 156SYSBEGIN(f3) 157 158SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 159SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 160 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0, 161 "Only do a single pass through ipfw when using dummynet(4)"); 162SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, 163 CTLFLAG_RW, &VNET_NAME(autoinc_step), 0, 164 "Rule number auto-increment step"); 165SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose, 166 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0, 167 "Log matches to ipfw rules"); 168SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, 169 CTLFLAG_RW, &VNET_NAME(verbose_limit), 0, 170 "Set upper limit of matches of ipfw rules logged"); 171SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD, 172 &dummy_def, 0, 173 "The default/max possible rule number."); 174SYSCTL_VNET_PROC(_net_inet_ip_fw, OID_AUTO, tables_max, 175 CTLTYPE_UINT|CTLFLAG_RW, 0, 0, sysctl_ipfw_table_num, "IU", 176 "Maximum number of tables"); 177SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN, 178 &default_to_accept, 0, 179 "Make the default rule accept all packets."); 180TUNABLE_INT("net.inet.ip.fw.default_to_accept", &default_to_accept); 181TUNABLE_INT("net.inet.ip.fw.tables_max", &default_fw_tables); 182SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, static_count, 183 CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0, 184 "Number of static rules"); 185 186#ifdef INET6 187SYSCTL_DECL(_net_inet6_ip6); 188SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 189SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs, 190 CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_deny_unknown_exthdrs), 0, 191 "Deny packets with unknown IPv6 Extension Headers"); 192SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6, 193 CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_permit_single_frag6), 0, 194 "Permit single packet IPv6 fragments"); 195#endif /* INET6 */ 196 197SYSEND 198 199#endif /* SYSCTL_NODE */ 200 201 202/* 203 * Some macros used in the various matching options. 204 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 205 * Other macros just cast void * into the appropriate type 206 */ 207#define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 208#define TCP(p) ((struct tcphdr *)(p)) 209#define SCTP(p) ((struct sctphdr *)(p)) 210#define UDP(p) ((struct udphdr *)(p)) 211#define ICMP(p) ((struct icmphdr *)(p)) 212#define ICMP6(p) ((struct icmp6_hdr *)(p)) 213 214static __inline int 215icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 216{ 217 int type = icmp->icmp_type; 218 219 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 220} 221 222#define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 223 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 224 225static int 226is_icmp_query(struct icmphdr *icmp) 227{ 228 int type = icmp->icmp_type; 229 230 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 231} 232#undef TT 233 234/* 235 * The following checks use two arrays of 8 or 16 bits to store the 236 * bits that we want set or clear, respectively. They are in the 237 * low and high half of cmd->arg1 or cmd->d[0]. 238 * 239 * We scan options and store the bits we find set. We succeed if 240 * 241 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 242 * 243 * The code is sometimes optimized not to store additional variables. 244 */ 245 246static int 247flags_match(ipfw_insn *cmd, u_int8_t bits) 248{ 249 u_char want_clear; 250 bits = ~bits; 251 252 if ( ((cmd->arg1 & 0xff) & bits) != 0) 253 return 0; /* some bits we want set were clear */ 254 want_clear = (cmd->arg1 >> 8) & 0xff; 255 if ( (want_clear & bits) != want_clear) 256 return 0; /* some bits we want clear were set */ 257 return 1; 258} 259 260static int 261ipopts_match(struct ip *ip, ipfw_insn *cmd) 262{ 263 int optlen, bits = 0; 264 u_char *cp = (u_char *)(ip + 1); 265 int x = (ip->ip_hl << 2) - sizeof (struct ip); 266 267 for (; x > 0; x -= optlen, cp += optlen) { 268 int opt = cp[IPOPT_OPTVAL]; 269 270 if (opt == IPOPT_EOL) 271 break; 272 if (opt == IPOPT_NOP) 273 optlen = 1; 274 else { 275 optlen = cp[IPOPT_OLEN]; 276 if (optlen <= 0 || optlen > x) 277 return 0; /* invalid or truncated */ 278 } 279 switch (opt) { 280 281 default: 282 break; 283 284 case IPOPT_LSRR: 285 bits |= IP_FW_IPOPT_LSRR; 286 break; 287 288 case IPOPT_SSRR: 289 bits |= IP_FW_IPOPT_SSRR; 290 break; 291 292 case IPOPT_RR: 293 bits |= IP_FW_IPOPT_RR; 294 break; 295 296 case IPOPT_TS: 297 bits |= IP_FW_IPOPT_TS; 298 break; 299 } 300 } 301 return (flags_match(cmd, bits)); 302} 303 304static int 305tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 306{ 307 int optlen, bits = 0; 308 u_char *cp = (u_char *)(tcp + 1); 309 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 310 311 for (; x > 0; x -= optlen, cp += optlen) { 312 int opt = cp[0]; 313 if (opt == TCPOPT_EOL) 314 break; 315 if (opt == TCPOPT_NOP) 316 optlen = 1; 317 else { 318 optlen = cp[1]; 319 if (optlen <= 0) 320 break; 321 } 322 323 switch (opt) { 324 325 default: 326 break; 327 328 case TCPOPT_MAXSEG: 329 bits |= IP_FW_TCPOPT_MSS; 330 break; 331 332 case TCPOPT_WINDOW: 333 bits |= IP_FW_TCPOPT_WINDOW; 334 break; 335 336 case TCPOPT_SACK_PERMITTED: 337 case TCPOPT_SACK: 338 bits |= IP_FW_TCPOPT_SACK; 339 break; 340 341 case TCPOPT_TIMESTAMP: 342 bits |= IP_FW_TCPOPT_TS; 343 break; 344 345 } 346 } 347 return (flags_match(cmd, bits)); 348} 349 350static int 351iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain, uint32_t *tablearg) 352{ 353 if (ifp == NULL) /* no iface with this packet, match fails */ 354 return 0; 355 /* Check by name or by IP address */ 356 if (cmd->name[0] != '\0') { /* match by name */ 357 if (cmd->name[0] == '\1') /* use tablearg to match */ 358 return ipfw_lookup_table_extended(chain, cmd->p.glob, 359 ifp->if_xname, tablearg, IPFW_TABLE_INTERFACE); 360 /* Check name */ 361 if (cmd->p.glob) { 362 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 363 return(1); 364 } else { 365 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 366 return(1); 367 } 368 } else { 369#ifdef __FreeBSD__ /* and OSX too ? */ 370 struct ifaddr *ia; 371 372 if_addr_rlock(ifp); 373 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 374 if (ia->ifa_addr->sa_family != AF_INET) 375 continue; 376 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 377 (ia->ifa_addr))->sin_addr.s_addr) { 378 if_addr_runlock(ifp); 379 return(1); /* match */ 380 } 381 } 382 if_addr_runlock(ifp); 383#endif /* __FreeBSD__ */ 384 } 385 return(0); /* no match, fail ... */ 386} 387 388/* 389 * The verify_path function checks if a route to the src exists and 390 * if it is reachable via ifp (when provided). 391 * 392 * The 'verrevpath' option checks that the interface that an IP packet 393 * arrives on is the same interface that traffic destined for the 394 * packet's source address would be routed out of. 395 * The 'versrcreach' option just checks that the source address is 396 * reachable via any route (except default) in the routing table. 397 * These two are a measure to block forged packets. This is also 398 * commonly known as "anti-spoofing" or Unicast Reverse Path 399 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 400 * is purposely reminiscent of the Cisco IOS command, 401 * 402 * ip verify unicast reverse-path 403 * ip verify unicast source reachable-via any 404 * 405 * which implements the same functionality. But note that the syntax 406 * is misleading, and the check may be performed on all IP packets 407 * whether unicast, multicast, or broadcast. 408 */ 409static int 410verify_path(struct in_addr src, struct ifnet *ifp, u_int fib) 411{ 412#ifndef __FreeBSD__ 413 return 0; 414#else 415 struct route ro; 416 struct sockaddr_in *dst; 417 418 bzero(&ro, sizeof(ro)); 419 420 dst = (struct sockaddr_in *)&(ro.ro_dst); 421 dst->sin_family = AF_INET; 422 dst->sin_len = sizeof(*dst); 423 dst->sin_addr = src; 424 in_rtalloc_ign(&ro, 0, fib); 425 426 if (ro.ro_rt == NULL) 427 return 0; 428 429 /* 430 * If ifp is provided, check for equality with rtentry. 431 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 432 * in order to pass packets injected back by if_simloop(): 433 * if useloopback == 1 routing entry (via lo0) for our own address 434 * may exist, so we need to handle routing assymetry. 435 */ 436 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 437 RTFREE(ro.ro_rt); 438 return 0; 439 } 440 441 /* if no ifp provided, check if rtentry is not default route */ 442 if (ifp == NULL && 443 satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) { 444 RTFREE(ro.ro_rt); 445 return 0; 446 } 447 448 /* or if this is a blackhole/reject route */ 449 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 450 RTFREE(ro.ro_rt); 451 return 0; 452 } 453 454 /* found valid route */ 455 RTFREE(ro.ro_rt); 456 return 1; 457#endif /* __FreeBSD__ */ 458} 459 460#ifdef INET6 461/* 462 * ipv6 specific rules here... 463 */ 464static __inline int 465icmp6type_match (int type, ipfw_insn_u32 *cmd) 466{ 467 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 468} 469 470static int 471flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 472{ 473 int i; 474 for (i=0; i <= cmd->o.arg1; ++i ) 475 if (curr_flow == cmd->d[i] ) 476 return 1; 477 return 0; 478} 479 480/* support for IP6_*_ME opcodes */ 481static int 482search_ip6_addr_net (struct in6_addr * ip6_addr) 483{ 484 struct ifnet *mdc; 485 struct ifaddr *mdc2; 486 struct in6_ifaddr *fdm; 487 struct in6_addr copia; 488 489 TAILQ_FOREACH(mdc, &V_ifnet, if_link) { 490 if_addr_rlock(mdc); 491 TAILQ_FOREACH(mdc2, &mdc->if_addrhead, ifa_link) { 492 if (mdc2->ifa_addr->sa_family == AF_INET6) { 493 fdm = (struct in6_ifaddr *)mdc2; 494 copia = fdm->ia_addr.sin6_addr; 495 /* need for leaving scope_id in the sock_addr */ 496 in6_clearscope(&copia); 497 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) { 498 if_addr_runlock(mdc); 499 return 1; 500 } 501 } 502 } 503 if_addr_runlock(mdc); 504 } 505 return 0; 506} 507 508static int 509verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib) 510{ 511 struct route_in6 ro; 512 struct sockaddr_in6 *dst; 513 514 bzero(&ro, sizeof(ro)); 515 516 dst = (struct sockaddr_in6 * )&(ro.ro_dst); 517 dst->sin6_family = AF_INET6; 518 dst->sin6_len = sizeof(*dst); 519 dst->sin6_addr = *src; 520 521 in6_rtalloc_ign(&ro, 0, fib); 522 if (ro.ro_rt == NULL) 523 return 0; 524 525 /* 526 * if ifp is provided, check for equality with rtentry 527 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 528 * to support the case of sending packets to an address of our own. 529 * (where the former interface is the first argument of if_simloop() 530 * (=ifp), the latter is lo0) 531 */ 532 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 533 RTFREE(ro.ro_rt); 534 return 0; 535 } 536 537 /* if no ifp provided, check if rtentry is not default route */ 538 if (ifp == NULL && 539 IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) { 540 RTFREE(ro.ro_rt); 541 return 0; 542 } 543 544 /* or if this is a blackhole/reject route */ 545 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 546 RTFREE(ro.ro_rt); 547 return 0; 548 } 549 550 /* found valid route */ 551 RTFREE(ro.ro_rt); 552 return 1; 553 554} 555 556static int 557is_icmp6_query(int icmp6_type) 558{ 559 if ((icmp6_type <= ICMP6_MAXTYPE) && 560 (icmp6_type == ICMP6_ECHO_REQUEST || 561 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 562 icmp6_type == ICMP6_WRUREQUEST || 563 icmp6_type == ICMP6_FQDN_QUERY || 564 icmp6_type == ICMP6_NI_QUERY)) 565 return (1); 566 567 return (0); 568} 569 570static void 571send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 572{ 573 struct mbuf *m; 574 575 m = args->m; 576 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 577 struct tcphdr *tcp; 578 tcp = (struct tcphdr *)((char *)ip6 + hlen); 579 580 if ((tcp->th_flags & TH_RST) == 0) { 581 struct mbuf *m0; 582 m0 = ipfw_send_pkt(args->m, &(args->f_id), 583 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 584 tcp->th_flags | TH_RST); 585 if (m0 != NULL) 586 ip6_output(m0, NULL, NULL, 0, NULL, NULL, 587 NULL); 588 } 589 FREE_PKT(m); 590 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */ 591#if 0 592 /* 593 * Unlike above, the mbufs need to line up with the ip6 hdr, 594 * as the contents are read. We need to m_adj() the 595 * needed amount. 596 * The mbuf will however be thrown away so we can adjust it. 597 * Remember we did an m_pullup on it already so we 598 * can make some assumptions about contiguousness. 599 */ 600 if (args->L3offset) 601 m_adj(m, args->L3offset); 602#endif 603 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 604 } else 605 FREE_PKT(m); 606 607 args->m = NULL; 608} 609 610#endif /* INET6 */ 611 612 613/* 614 * sends a reject message, consuming the mbuf passed as an argument. 615 */ 616static void 617send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip) 618{ 619 620#if 0 621 /* XXX When ip is not guaranteed to be at mtod() we will 622 * need to account for this */ 623 * The mbuf will however be thrown away so we can adjust it. 624 * Remember we did an m_pullup on it already so we 625 * can make some assumptions about contiguousness. 626 */ 627 if (args->L3offset) 628 m_adj(m, args->L3offset); 629#endif 630 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */ 631 /* We need the IP header in host order for icmp_error(). */ 632 SET_HOST_IPLEN(ip); 633 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 634 } else if (args->f_id.proto == IPPROTO_TCP) { 635 struct tcphdr *const tcp = 636 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 637 if ( (tcp->th_flags & TH_RST) == 0) { 638 struct mbuf *m; 639 m = ipfw_send_pkt(args->m, &(args->f_id), 640 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 641 tcp->th_flags | TH_RST); 642 if (m != NULL) 643 ip_output(m, NULL, NULL, 0, NULL, NULL); 644 } 645 FREE_PKT(args->m); 646 } else 647 FREE_PKT(args->m); 648 args->m = NULL; 649} 650 651/* 652 * Support for uid/gid/jail lookup. These tests are expensive 653 * (because we may need to look into the list of active sockets) 654 * so we cache the results. ugid_lookupp is 0 if we have not 655 * yet done a lookup, 1 if we succeeded, and -1 if we tried 656 * and failed. The function always returns the match value. 657 * We could actually spare the variable and use *uc, setting 658 * it to '(void *)check_uidgid if we have no info, NULL if 659 * we tried and failed, or any other value if successful. 660 */ 661static int 662check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp, 663 struct ucred **uc) 664{ 665#ifndef __FreeBSD__ 666 /* XXX */ 667 return cred_check(insn, proto, oif, 668 dst_ip, dst_port, src_ip, src_port, 669 (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb); 670#else /* FreeBSD */ 671 struct in_addr src_ip, dst_ip; 672 struct inpcbinfo *pi; 673 struct ipfw_flow_id *id; 674 struct inpcb *pcb, *inp; 675 struct ifnet *oif; 676 int lookupflags; 677 int match; 678 679 id = &args->f_id; 680 inp = args->inp; 681 oif = args->oif; 682 683 /* 684 * Check to see if the UDP or TCP stack supplied us with 685 * the PCB. If so, rather then holding a lock and looking 686 * up the PCB, we can use the one that was supplied. 687 */ 688 if (inp && *ugid_lookupp == 0) { 689 INP_LOCK_ASSERT(inp); 690 if (inp->inp_socket != NULL) { 691 *uc = crhold(inp->inp_cred); 692 *ugid_lookupp = 1; 693 } else 694 *ugid_lookupp = -1; 695 } 696 /* 697 * If we have already been here and the packet has no 698 * PCB entry associated with it, then we can safely 699 * assume that this is a no match. 700 */ 701 if (*ugid_lookupp == -1) 702 return (0); 703 if (id->proto == IPPROTO_TCP) { 704 lookupflags = 0; 705 pi = &V_tcbinfo; 706 } else if (id->proto == IPPROTO_UDP) { 707 lookupflags = INPLOOKUP_WILDCARD; 708 pi = &V_udbinfo; 709 } else 710 return 0; 711 lookupflags |= INPLOOKUP_RLOCKPCB; 712 match = 0; 713 if (*ugid_lookupp == 0) { 714 if (id->addr_type == 6) { 715#ifdef INET6 716 if (oif == NULL) 717 pcb = in6_pcblookup_mbuf(pi, 718 &id->src_ip6, htons(id->src_port), 719 &id->dst_ip6, htons(id->dst_port), 720 lookupflags, oif, args->m); 721 else 722 pcb = in6_pcblookup_mbuf(pi, 723 &id->dst_ip6, htons(id->dst_port), 724 &id->src_ip6, htons(id->src_port), 725 lookupflags, oif, args->m); 726#else 727 *ugid_lookupp = -1; 728 return (0); 729#endif 730 } else { 731 src_ip.s_addr = htonl(id->src_ip); 732 dst_ip.s_addr = htonl(id->dst_ip); 733 if (oif == NULL) 734 pcb = in_pcblookup_mbuf(pi, 735 src_ip, htons(id->src_port), 736 dst_ip, htons(id->dst_port), 737 lookupflags, oif, args->m); 738 else 739 pcb = in_pcblookup_mbuf(pi, 740 dst_ip, htons(id->dst_port), 741 src_ip, htons(id->src_port), 742 lookupflags, oif, args->m); 743 } 744 if (pcb != NULL) { 745 INP_RLOCK_ASSERT(pcb); 746 *uc = crhold(pcb->inp_cred); 747 *ugid_lookupp = 1; 748 INP_RUNLOCK(pcb); 749 } 750 if (*ugid_lookupp == 0) { 751 /* 752 * We tried and failed, set the variable to -1 753 * so we will not try again on this packet. 754 */ 755 *ugid_lookupp = -1; 756 return (0); 757 } 758 } 759 if (insn->o.opcode == O_UID) 760 match = ((*uc)->cr_uid == (uid_t)insn->d[0]); 761 else if (insn->o.opcode == O_GID) 762 match = groupmember((gid_t)insn->d[0], *uc); 763 else if (insn->o.opcode == O_JAIL) 764 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]); 765 return (match); 766#endif /* __FreeBSD__ */ 767} 768 769/* 770 * Helper function to set args with info on the rule after the matching 771 * one. slot is precise, whereas we guess rule_id as they are 772 * assigned sequentially. 773 */ 774static inline void 775set_match(struct ip_fw_args *args, int slot, 776 struct ip_fw_chain *chain) 777{ 778 args->rule.chain_id = chain->id; 779 args->rule.slot = slot + 1; /* we use 0 as a marker */ 780 args->rule.rule_id = 1 + chain->map[slot]->id; 781 args->rule.rulenum = chain->map[slot]->rulenum; 782} 783 784/* 785 * Helper function to enable cached rule lookups using 786 * x_next and next_rule fields in ipfw rule. 787 */ 788static int 789jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 790 int tablearg, int jump_backwards) 791{ 792 int f_pos; 793 794 /* If possible use cached f_pos (in f->next_rule), 795 * whose version is written in f->next_rule 796 * (horrible hacks to avoid changing the ABI). 797 */ 798 if (num != IP_FW_TABLEARG && (uintptr_t)f->x_next == chain->id) 799 f_pos = (uintptr_t)f->next_rule; 800 else { 801 int i = IP_FW_ARG_TABLEARG(num); 802 /* make sure we do not jump backward */ 803 if (jump_backwards == 0 && i <= f->rulenum) 804 i = f->rulenum + 1; 805 f_pos = ipfw_find_rule(chain, i, 0); 806 /* update the cache */ 807 if (num != IP_FW_TABLEARG) { 808 f->next_rule = (void *)(uintptr_t)f_pos; 809 f->x_next = (void *)(uintptr_t)chain->id; 810 } 811 } 812 813 return (f_pos); 814} 815 816/* 817 * The main check routine for the firewall. 818 * 819 * All arguments are in args so we can modify them and return them 820 * back to the caller. 821 * 822 * Parameters: 823 * 824 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 825 * Starts with the IP header. 826 * args->eh (in) Mac header if present, NULL for layer3 packet. 827 * args->L3offset Number of bytes bypassed if we came from L2. 828 * e.g. often sizeof(eh) ** NOTYET ** 829 * args->oif Outgoing interface, NULL if packet is incoming. 830 * The incoming interface is in the mbuf. (in) 831 * args->divert_rule (in/out) 832 * Skip up to the first rule past this rule number; 833 * upon return, non-zero port number for divert or tee. 834 * 835 * args->rule Pointer to the last matching rule (in/out) 836 * args->next_hop Socket we are forwarding to (out). 837 * args->next_hop6 IPv6 next hop we are forwarding to (out). 838 * args->f_id Addresses grabbed from the packet (out) 839 * args->rule.info a cookie depending on rule action 840 * 841 * Return value: 842 * 843 * IP_FW_PASS the packet must be accepted 844 * IP_FW_DENY the packet must be dropped 845 * IP_FW_DIVERT divert packet, port in m_tag 846 * IP_FW_TEE tee packet, port in m_tag 847 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 848 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 849 * args->rule contains the matching rule, 850 * args->rule.info has additional information. 851 * 852 */ 853int 854ipfw_chk(struct ip_fw_args *args) 855{ 856 857 /* 858 * Local variables holding state while processing a packet: 859 * 860 * IMPORTANT NOTE: to speed up the processing of rules, there 861 * are some assumption on the values of the variables, which 862 * are documented here. Should you change them, please check 863 * the implementation of the various instructions to make sure 864 * that they still work. 865 * 866 * args->eh The MAC header. It is non-null for a layer2 867 * packet, it is NULL for a layer-3 packet. 868 * **notyet** 869 * args->L3offset Offset in the packet to the L3 (IP or equiv.) header. 870 * 871 * m | args->m Pointer to the mbuf, as received from the caller. 872 * It may change if ipfw_chk() does an m_pullup, or if it 873 * consumes the packet because it calls send_reject(). 874 * XXX This has to change, so that ipfw_chk() never modifies 875 * or consumes the buffer. 876 * ip is the beginning of the ip(4 or 6) header. 877 * Calculated by adding the L3offset to the start of data. 878 * (Until we start using L3offset, the packet is 879 * supposed to start with the ip header). 880 */ 881 struct mbuf *m = args->m; 882 struct ip *ip = mtod(m, struct ip *); 883 884 /* 885 * For rules which contain uid/gid or jail constraints, cache 886 * a copy of the users credentials after the pcb lookup has been 887 * executed. This will speed up the processing of rules with 888 * these types of constraints, as well as decrease contention 889 * on pcb related locks. 890 */ 891#ifndef __FreeBSD__ 892 struct bsd_ucred ucred_cache; 893#else 894 struct ucred *ucred_cache = NULL; 895#endif 896 int ucred_lookup = 0; 897 898 /* 899 * oif | args->oif If NULL, ipfw_chk has been called on the 900 * inbound path (ether_input, ip_input). 901 * If non-NULL, ipfw_chk has been called on the outbound path 902 * (ether_output, ip_output). 903 */ 904 struct ifnet *oif = args->oif; 905 906 int f_pos = 0; /* index of current rule in the array */ 907 int retval = 0; 908 909 /* 910 * hlen The length of the IP header. 911 */ 912 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 913 914 /* 915 * offset The offset of a fragment. offset != 0 means that 916 * we have a fragment at this offset of an IPv4 packet. 917 * offset == 0 means that (if this is an IPv4 packet) 918 * this is the first or only fragment. 919 * For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header 920 * or there is a single packet fragement (fragement header added 921 * without needed). We will treat a single packet fragment as if 922 * there was no fragment header (or log/block depending on the 923 * V_fw_permit_single_frag6 sysctl setting). 924 */ 925 u_short offset = 0; 926 u_short ip6f_mf = 0; 927 928 /* 929 * Local copies of addresses. They are only valid if we have 930 * an IP packet. 931 * 932 * proto The protocol. Set to 0 for non-ip packets, 933 * or to the protocol read from the packet otherwise. 934 * proto != 0 means that we have an IPv4 packet. 935 * 936 * src_port, dst_port port numbers, in HOST format. Only 937 * valid for TCP and UDP packets. 938 * 939 * src_ip, dst_ip ip addresses, in NETWORK format. 940 * Only valid for IPv4 packets. 941 */ 942 uint8_t proto; 943 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 944 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 945 uint16_t iplen=0; 946 int pktlen; 947 uint16_t etype = 0; /* Host order stored ether type */ 948 949 /* 950 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 951 * MATCH_NONE when checked and not matched (q = NULL), 952 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) 953 */ 954 int dyn_dir = MATCH_UNKNOWN; 955 ipfw_dyn_rule *q = NULL; 956 struct ip_fw_chain *chain = &V_layer3_chain; 957 958 /* 959 * We store in ulp a pointer to the upper layer protocol header. 960 * In the ipv4 case this is easy to determine from the header, 961 * but for ipv6 we might have some additional headers in the middle. 962 * ulp is NULL if not found. 963 */ 964 void *ulp = NULL; /* upper layer protocol pointer. */ 965 966 /* XXX ipv6 variables */ 967 int is_ipv6 = 0; 968 uint8_t icmp6_type = 0; 969 uint16_t ext_hd = 0; /* bits vector for extension header filtering */ 970 /* end of ipv6 variables */ 971 972 int is_ipv4 = 0; 973 974 int done = 0; /* flag to exit the outer loop */ 975 976 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready)) 977 return (IP_FW_PASS); /* accept */ 978 979 dst_ip.s_addr = 0; /* make sure it is initialized */ 980 src_ip.s_addr = 0; /* make sure it is initialized */ 981 pktlen = m->m_pkthdr.len; 982 args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */ 983 proto = args->f_id.proto = 0; /* mark f_id invalid */ 984 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ 985 986/* 987 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 988 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 989 * pointer might become stale after other pullups (but we never use it 990 * this way). 991 */ 992#define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T)) 993#define PULLUP_LEN(_len, p, T) \ 994do { \ 995 int x = (_len) + T; \ 996 if ((m)->m_len < x) { \ 997 args->m = m = m_pullup(m, x); \ 998 if (m == NULL) \ 999 goto pullup_failed; \ 1000 } \ 1001 p = (mtod(m, char *) + (_len)); \ 1002} while (0) 1003 1004 /* 1005 * if we have an ether header, 1006 */ 1007 if (args->eh) 1008 etype = ntohs(args->eh->ether_type); 1009 1010 /* Identify IP packets and fill up variables. */ 1011 if (pktlen >= sizeof(struct ip6_hdr) && 1012 (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) { 1013 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 1014 is_ipv6 = 1; 1015 args->f_id.addr_type = 6; 1016 hlen = sizeof(struct ip6_hdr); 1017 proto = ip6->ip6_nxt; 1018 1019 /* Search extension headers to find upper layer protocols */ 1020 while (ulp == NULL && offset == 0) { 1021 switch (proto) { 1022 case IPPROTO_ICMPV6: 1023 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 1024 icmp6_type = ICMP6(ulp)->icmp6_type; 1025 break; 1026 1027 case IPPROTO_TCP: 1028 PULLUP_TO(hlen, ulp, struct tcphdr); 1029 dst_port = TCP(ulp)->th_dport; 1030 src_port = TCP(ulp)->th_sport; 1031 /* save flags for dynamic rules */ 1032 args->f_id._flags = TCP(ulp)->th_flags; 1033 break; 1034 1035 case IPPROTO_SCTP: 1036 PULLUP_TO(hlen, ulp, struct sctphdr); 1037 src_port = SCTP(ulp)->src_port; 1038 dst_port = SCTP(ulp)->dest_port; 1039 break; 1040 1041 case IPPROTO_UDP: 1042 PULLUP_TO(hlen, ulp, struct udphdr); 1043 dst_port = UDP(ulp)->uh_dport; 1044 src_port = UDP(ulp)->uh_sport; 1045 break; 1046 1047 case IPPROTO_HOPOPTS: /* RFC 2460 */ 1048 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1049 ext_hd |= EXT_HOPOPTS; 1050 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1051 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1052 ulp = NULL; 1053 break; 1054 1055 case IPPROTO_ROUTING: /* RFC 2460 */ 1056 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 1057 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 1058 case 0: 1059 ext_hd |= EXT_RTHDR0; 1060 break; 1061 case 2: 1062 ext_hd |= EXT_RTHDR2; 1063 break; 1064 default: 1065 if (V_fw_verbose) 1066 printf("IPFW2: IPV6 - Unknown " 1067 "Routing Header type(%d)\n", 1068 ((struct ip6_rthdr *) 1069 ulp)->ip6r_type); 1070 if (V_fw_deny_unknown_exthdrs) 1071 return (IP_FW_DENY); 1072 break; 1073 } 1074 ext_hd |= EXT_ROUTING; 1075 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 1076 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 1077 ulp = NULL; 1078 break; 1079 1080 case IPPROTO_FRAGMENT: /* RFC 2460 */ 1081 PULLUP_TO(hlen, ulp, struct ip6_frag); 1082 ext_hd |= EXT_FRAGMENT; 1083 hlen += sizeof (struct ip6_frag); 1084 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 1085 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 1086 IP6F_OFF_MASK; 1087 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg & 1088 IP6F_MORE_FRAG; 1089 if (V_fw_permit_single_frag6 == 0 && 1090 offset == 0 && ip6f_mf == 0) { 1091 if (V_fw_verbose) 1092 printf("IPFW2: IPV6 - Invalid " 1093 "Fragment Header\n"); 1094 if (V_fw_deny_unknown_exthdrs) 1095 return (IP_FW_DENY); 1096 break; 1097 } 1098 args->f_id.extra = 1099 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 1100 ulp = NULL; 1101 break; 1102 1103 case IPPROTO_DSTOPTS: /* RFC 2460 */ 1104 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1105 ext_hd |= EXT_DSTOPTS; 1106 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1107 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1108 ulp = NULL; 1109 break; 1110 1111 case IPPROTO_AH: /* RFC 2402 */ 1112 PULLUP_TO(hlen, ulp, struct ip6_ext); 1113 ext_hd |= EXT_AH; 1114 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 1115 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 1116 ulp = NULL; 1117 break; 1118 1119 case IPPROTO_ESP: /* RFC 2406 */ 1120 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 1121 /* Anything past Seq# is variable length and 1122 * data past this ext. header is encrypted. */ 1123 ext_hd |= EXT_ESP; 1124 break; 1125 1126 case IPPROTO_NONE: /* RFC 2460 */ 1127 /* 1128 * Packet ends here, and IPv6 header has 1129 * already been pulled up. If ip6e_len!=0 1130 * then octets must be ignored. 1131 */ 1132 ulp = ip; /* non-NULL to get out of loop. */ 1133 break; 1134 1135 case IPPROTO_OSPFIGP: 1136 /* XXX OSPF header check? */ 1137 PULLUP_TO(hlen, ulp, struct ip6_ext); 1138 break; 1139 1140 case IPPROTO_PIM: 1141 /* XXX PIM header check? */ 1142 PULLUP_TO(hlen, ulp, struct pim); 1143 break; 1144 1145 case IPPROTO_CARP: 1146 PULLUP_TO(hlen, ulp, struct carp_header); 1147 if (((struct carp_header *)ulp)->carp_version != 1148 CARP_VERSION) 1149 return (IP_FW_DENY); 1150 if (((struct carp_header *)ulp)->carp_type != 1151 CARP_ADVERTISEMENT) 1152 return (IP_FW_DENY); 1153 break; 1154 1155 case IPPROTO_IPV6: /* RFC 2893 */ 1156 PULLUP_TO(hlen, ulp, struct ip6_hdr); 1157 break; 1158 1159 case IPPROTO_IPV4: /* RFC 2893 */ 1160 PULLUP_TO(hlen, ulp, struct ip); 1161 break; 1162 1163 default: 1164 if (V_fw_verbose) 1165 printf("IPFW2: IPV6 - Unknown " 1166 "Extension Header(%d), ext_hd=%x\n", 1167 proto, ext_hd); 1168 if (V_fw_deny_unknown_exthdrs) 1169 return (IP_FW_DENY); 1170 PULLUP_TO(hlen, ulp, struct ip6_ext); 1171 break; 1172 } /*switch */ 1173 } 1174 ip = mtod(m, struct ip *); 1175 ip6 = (struct ip6_hdr *)ip; 1176 args->f_id.src_ip6 = ip6->ip6_src; 1177 args->f_id.dst_ip6 = ip6->ip6_dst; 1178 args->f_id.src_ip = 0; 1179 args->f_id.dst_ip = 0; 1180 args->f_id.flow_id6 = ntohl(ip6->ip6_flow); 1181 } else if (pktlen >= sizeof(struct ip) && 1182 (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) { 1183 is_ipv4 = 1; 1184 hlen = ip->ip_hl << 2; 1185 args->f_id.addr_type = 4; 1186 1187 /* 1188 * Collect parameters into local variables for faster matching. 1189 */ 1190 proto = ip->ip_p; 1191 src_ip = ip->ip_src; 1192 dst_ip = ip->ip_dst; 1193 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1194 iplen = ntohs(ip->ip_len); 1195 pktlen = iplen < pktlen ? iplen : pktlen; 1196 1197 if (offset == 0) { 1198 switch (proto) { 1199 case IPPROTO_TCP: 1200 PULLUP_TO(hlen, ulp, struct tcphdr); 1201 dst_port = TCP(ulp)->th_dport; 1202 src_port = TCP(ulp)->th_sport; 1203 /* save flags for dynamic rules */ 1204 args->f_id._flags = TCP(ulp)->th_flags; 1205 break; 1206 1207 case IPPROTO_SCTP: 1208 PULLUP_TO(hlen, ulp, struct sctphdr); 1209 src_port = SCTP(ulp)->src_port; 1210 dst_port = SCTP(ulp)->dest_port; 1211 break; 1212 1213 case IPPROTO_UDP: 1214 PULLUP_TO(hlen, ulp, struct udphdr); 1215 dst_port = UDP(ulp)->uh_dport; 1216 src_port = UDP(ulp)->uh_sport; 1217 break; 1218 1219 case IPPROTO_ICMP: 1220 PULLUP_TO(hlen, ulp, struct icmphdr); 1221 //args->f_id.flags = ICMP(ulp)->icmp_type; 1222 break; 1223 1224 default: 1225 break; 1226 } 1227 } 1228 1229 ip = mtod(m, struct ip *); 1230 args->f_id.src_ip = ntohl(src_ip.s_addr); 1231 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1232 } 1233#undef PULLUP_TO 1234 if (proto) { /* we may have port numbers, store them */ 1235 args->f_id.proto = proto; 1236 args->f_id.src_port = src_port = ntohs(src_port); 1237 args->f_id.dst_port = dst_port = ntohs(dst_port); 1238 } 1239 1240 IPFW_RLOCK(chain); 1241 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ 1242 IPFW_RUNLOCK(chain); 1243 return (IP_FW_PASS); /* accept */ 1244 } 1245 if (args->rule.slot) { 1246 /* 1247 * Packet has already been tagged as a result of a previous 1248 * match on rule args->rule aka args->rule_id (PIPE, QUEUE, 1249 * REASS, NETGRAPH, DIVERT/TEE...) 1250 * Validate the slot and continue from the next one 1251 * if still present, otherwise do a lookup. 1252 */ 1253 f_pos = (args->rule.chain_id == chain->id) ? 1254 args->rule.slot : 1255 ipfw_find_rule(chain, args->rule.rulenum, 1256 args->rule.rule_id); 1257 } else { 1258 f_pos = 0; 1259 } 1260 1261 /* 1262 * Now scan the rules, and parse microinstructions for each rule. 1263 * We have two nested loops and an inner switch. Sometimes we 1264 * need to break out of one or both loops, or re-enter one of 1265 * the loops with updated variables. Loop variables are: 1266 * 1267 * f_pos (outer loop) points to the current rule. 1268 * On output it points to the matching rule. 1269 * done (outer loop) is used as a flag to break the loop. 1270 * l (inner loop) residual length of current rule. 1271 * cmd points to the current microinstruction. 1272 * 1273 * We break the inner loop by setting l=0 and possibly 1274 * cmdlen=0 if we don't want to advance cmd. 1275 * We break the outer loop by setting done=1 1276 * We can restart the inner loop by setting l>0 and f_pos, f, cmd 1277 * as needed. 1278 */ 1279 for (; f_pos < chain->n_rules; f_pos++) { 1280 ipfw_insn *cmd; 1281 uint32_t tablearg = 0; 1282 int l, cmdlen, skip_or; /* skip rest of OR block */ 1283 struct ip_fw *f; 1284 1285 f = chain->map[f_pos]; 1286 if (V_set_disable & (1 << f->set) ) 1287 continue; 1288 1289 skip_or = 0; 1290 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 1291 l -= cmdlen, cmd += cmdlen) { 1292 int match; 1293 1294 /* 1295 * check_body is a jump target used when we find a 1296 * CHECK_STATE, and need to jump to the body of 1297 * the target rule. 1298 */ 1299 1300/* check_body: */ 1301 cmdlen = F_LEN(cmd); 1302 /* 1303 * An OR block (insn_1 || .. || insn_n) has the 1304 * F_OR bit set in all but the last instruction. 1305 * The first match will set "skip_or", and cause 1306 * the following instructions to be skipped until 1307 * past the one with the F_OR bit clear. 1308 */ 1309 if (skip_or) { /* skip this instruction */ 1310 if ((cmd->len & F_OR) == 0) 1311 skip_or = 0; /* next one is good */ 1312 continue; 1313 } 1314 match = 0; /* set to 1 if we succeed */ 1315 1316 switch (cmd->opcode) { 1317 /* 1318 * The first set of opcodes compares the packet's 1319 * fields with some pattern, setting 'match' if a 1320 * match is found. At the end of the loop there is 1321 * logic to deal with F_NOT and F_OR flags associated 1322 * with the opcode. 1323 */ 1324 case O_NOP: 1325 match = 1; 1326 break; 1327 1328 case O_FORWARD_MAC: 1329 printf("ipfw: opcode %d unimplemented\n", 1330 cmd->opcode); 1331 break; 1332 1333 case O_GID: 1334 case O_UID: 1335 case O_JAIL: 1336 /* 1337 * We only check offset == 0 && proto != 0, 1338 * as this ensures that we have a 1339 * packet with the ports info. 1340 */ 1341 if (offset != 0) 1342 break; 1343 if (proto == IPPROTO_TCP || 1344 proto == IPPROTO_UDP) 1345 match = check_uidgid( 1346 (ipfw_insn_u32 *)cmd, 1347 args, &ucred_lookup, 1348#ifdef __FreeBSD__ 1349 &ucred_cache); 1350#else 1351 (void *)&ucred_cache); 1352#endif 1353 break; 1354 1355 case O_RECV: 1356 match = iface_match(m->m_pkthdr.rcvif, 1357 (ipfw_insn_if *)cmd, chain, &tablearg); 1358 break; 1359 1360 case O_XMIT: 1361 match = iface_match(oif, (ipfw_insn_if *)cmd, 1362 chain, &tablearg); 1363 break; 1364 1365 case O_VIA: 1366 match = iface_match(oif ? oif : 1367 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd, 1368 chain, &tablearg); 1369 break; 1370 1371 case O_MACADDR2: 1372 if (args->eh != NULL) { /* have MAC header */ 1373 u_int32_t *want = (u_int32_t *) 1374 ((ipfw_insn_mac *)cmd)->addr; 1375 u_int32_t *mask = (u_int32_t *) 1376 ((ipfw_insn_mac *)cmd)->mask; 1377 u_int32_t *hdr = (u_int32_t *)args->eh; 1378 1379 match = 1380 ( want[0] == (hdr[0] & mask[0]) && 1381 want[1] == (hdr[1] & mask[1]) && 1382 want[2] == (hdr[2] & mask[2]) ); 1383 } 1384 break; 1385 1386 case O_MAC_TYPE: 1387 if (args->eh != NULL) { 1388 u_int16_t *p = 1389 ((ipfw_insn_u16 *)cmd)->ports; 1390 int i; 1391 1392 for (i = cmdlen - 1; !match && i>0; 1393 i--, p += 2) 1394 match = (etype >= p[0] && 1395 etype <= p[1]); 1396 } 1397 break; 1398 1399 case O_FRAG: 1400 match = (offset != 0); 1401 break; 1402 1403 case O_IN: /* "out" is "not in" */ 1404 match = (oif == NULL); 1405 break; 1406 1407 case O_LAYER2: 1408 match = (args->eh != NULL); 1409 break; 1410 1411 case O_DIVERTED: 1412 { 1413 /* For diverted packets, args->rule.info 1414 * contains the divert port (in host format) 1415 * reason and direction. 1416 */ 1417 uint32_t i = args->rule.info; 1418 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT && 1419 cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2); 1420 } 1421 break; 1422 1423 case O_PROTO: 1424 /* 1425 * We do not allow an arg of 0 so the 1426 * check of "proto" only suffices. 1427 */ 1428 match = (proto == cmd->arg1); 1429 break; 1430 1431 case O_IP_SRC: 1432 match = is_ipv4 && 1433 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1434 src_ip.s_addr); 1435 break; 1436 1437 case O_IP_SRC_LOOKUP: 1438 case O_IP_DST_LOOKUP: 1439 if (is_ipv4) { 1440 uint32_t key = 1441 (cmd->opcode == O_IP_DST_LOOKUP) ? 1442 dst_ip.s_addr : src_ip.s_addr; 1443 uint32_t v = 0; 1444 1445 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { 1446 /* generic lookup. The key must be 1447 * in 32bit big-endian format. 1448 */ 1449 v = ((ipfw_insn_u32 *)cmd)->d[1]; 1450 if (v == 0) 1451 key = dst_ip.s_addr; 1452 else if (v == 1) 1453 key = src_ip.s_addr; 1454 else if (v == 6) /* dscp */ 1455 key = (ip->ip_tos >> 2) & 0x3f; 1456 else if (offset != 0) 1457 break; 1458 else if (proto != IPPROTO_TCP && 1459 proto != IPPROTO_UDP) 1460 break; 1461 else if (v == 2) 1462 key = htonl(dst_port); 1463 else if (v == 3) 1464 key = htonl(src_port); 1465 else if (v == 4 || v == 5) { 1466 check_uidgid( 1467 (ipfw_insn_u32 *)cmd, 1468 args, &ucred_lookup, 1469#ifdef __FreeBSD__ 1470 &ucred_cache); 1471 if (v == 4 /* O_UID */) 1472 key = ucred_cache->cr_uid; 1473 else if (v == 5 /* O_JAIL */) 1474 key = ucred_cache->cr_prison->pr_id; 1475#else /* !__FreeBSD__ */ 1476 (void *)&ucred_cache); 1477 if (v ==4 /* O_UID */) 1478 key = ucred_cache.uid; 1479 else if (v == 5 /* O_JAIL */) 1480 key = ucred_cache.xid; 1481#endif /* !__FreeBSD__ */ 1482 key = htonl(key); 1483 } else 1484 break; 1485 } 1486 match = ipfw_lookup_table(chain, 1487 cmd->arg1, key, &v); 1488 if (!match) 1489 break; 1490 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1491 match = 1492 ((ipfw_insn_u32 *)cmd)->d[0] == v; 1493 else 1494 tablearg = v; 1495 } else if (is_ipv6) { 1496 uint32_t v = 0; 1497 void *pkey = (cmd->opcode == O_IP_DST_LOOKUP) ? 1498 &args->f_id.dst_ip6: &args->f_id.src_ip6; 1499 match = ipfw_lookup_table_extended(chain, 1500 cmd->arg1, pkey, &v, 1501 IPFW_TABLE_CIDR); 1502 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1503 match = ((ipfw_insn_u32 *)cmd)->d[0] == v; 1504 if (match) 1505 tablearg = v; 1506 } 1507 break; 1508 1509 case O_IP_SRC_MASK: 1510 case O_IP_DST_MASK: 1511 if (is_ipv4) { 1512 uint32_t a = 1513 (cmd->opcode == O_IP_DST_MASK) ? 1514 dst_ip.s_addr : src_ip.s_addr; 1515 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 1516 int i = cmdlen-1; 1517 1518 for (; !match && i>0; i-= 2, p+= 2) 1519 match = (p[0] == (a & p[1])); 1520 } 1521 break; 1522 1523 case O_IP_SRC_ME: 1524 if (is_ipv4) { 1525 struct ifnet *tif; 1526 1527 INADDR_TO_IFP(src_ip, tif); 1528 match = (tif != NULL); 1529 break; 1530 } 1531#ifdef INET6 1532 /* FALLTHROUGH */ 1533 case O_IP6_SRC_ME: 1534 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6); 1535#endif 1536 break; 1537 1538 case O_IP_DST_SET: 1539 case O_IP_SRC_SET: 1540 if (is_ipv4) { 1541 u_int32_t *d = (u_int32_t *)(cmd+1); 1542 u_int32_t addr = 1543 cmd->opcode == O_IP_DST_SET ? 1544 args->f_id.dst_ip : 1545 args->f_id.src_ip; 1546 1547 if (addr < d[0]) 1548 break; 1549 addr -= d[0]; /* subtract base */ 1550 match = (addr < cmd->arg1) && 1551 ( d[ 1 + (addr>>5)] & 1552 (1<<(addr & 0x1f)) ); 1553 } 1554 break; 1555 1556 case O_IP_DST: 1557 match = is_ipv4 && 1558 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1559 dst_ip.s_addr); 1560 break; 1561 1562 case O_IP_DST_ME: 1563 if (is_ipv4) { 1564 struct ifnet *tif; 1565 1566 INADDR_TO_IFP(dst_ip, tif); 1567 match = (tif != NULL); 1568 break; 1569 } 1570#ifdef INET6 1571 /* FALLTHROUGH */ 1572 case O_IP6_DST_ME: 1573 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6); 1574#endif 1575 break; 1576 1577 1578 case O_IP_SRCPORT: 1579 case O_IP_DSTPORT: 1580 /* 1581 * offset == 0 && proto != 0 is enough 1582 * to guarantee that we have a 1583 * packet with port info. 1584 */ 1585 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP) 1586 && offset == 0) { 1587 u_int16_t x = 1588 (cmd->opcode == O_IP_SRCPORT) ? 1589 src_port : dst_port ; 1590 u_int16_t *p = 1591 ((ipfw_insn_u16 *)cmd)->ports; 1592 int i; 1593 1594 for (i = cmdlen - 1; !match && i>0; 1595 i--, p += 2) 1596 match = (x>=p[0] && x<=p[1]); 1597 } 1598 break; 1599 1600 case O_ICMPTYPE: 1601 match = (offset == 0 && proto==IPPROTO_ICMP && 1602 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 1603 break; 1604 1605#ifdef INET6 1606 case O_ICMP6TYPE: 1607 match = is_ipv6 && offset == 0 && 1608 proto==IPPROTO_ICMPV6 && 1609 icmp6type_match( 1610 ICMP6(ulp)->icmp6_type, 1611 (ipfw_insn_u32 *)cmd); 1612 break; 1613#endif /* INET6 */ 1614 1615 case O_IPOPT: 1616 match = (is_ipv4 && 1617 ipopts_match(ip, cmd) ); 1618 break; 1619 1620 case O_IPVER: 1621 match = (is_ipv4 && 1622 cmd->arg1 == ip->ip_v); 1623 break; 1624 1625 case O_IPID: 1626 case O_IPLEN: 1627 case O_IPTTL: 1628 if (is_ipv4) { /* only for IP packets */ 1629 uint16_t x; 1630 uint16_t *p; 1631 int i; 1632 1633 if (cmd->opcode == O_IPLEN) 1634 x = iplen; 1635 else if (cmd->opcode == O_IPTTL) 1636 x = ip->ip_ttl; 1637 else /* must be IPID */ 1638 x = ntohs(ip->ip_id); 1639 if (cmdlen == 1) { 1640 match = (cmd->arg1 == x); 1641 break; 1642 } 1643 /* otherwise we have ranges */ 1644 p = ((ipfw_insn_u16 *)cmd)->ports; 1645 i = cmdlen - 1; 1646 for (; !match && i>0; i--, p += 2) 1647 match = (x >= p[0] && x <= p[1]); 1648 } 1649 break; 1650 1651 case O_IPPRECEDENCE: 1652 match = (is_ipv4 && 1653 (cmd->arg1 == (ip->ip_tos & 0xe0)) ); 1654 break; 1655 1656 case O_IPTOS: 1657 match = (is_ipv4 && 1658 flags_match(cmd, ip->ip_tos)); 1659 break; 1660 1661 case O_DSCP: 1662 { 1663 uint32_t *p; 1664 uint16_t x; 1665 1666 p = ((ipfw_insn_u32 *)cmd)->d; 1667 1668 if (is_ipv4) 1669 x = ip->ip_tos >> 2; 1670 else if (is_ipv6) { 1671 uint8_t *v; 1672 v = &((struct ip6_hdr *)ip)->ip6_vfc; 1673 x = (*v & 0x0F) << 2; 1674 v++; 1675 x |= *v >> 6; 1676 } else 1677 break; 1678 1679 /* DSCP bitmask is stored as low_u32 high_u32 */ 1680 if (x > 32) 1681 match = *(p + 1) & (1 << (x - 32)); 1682 else 1683 match = *p & (1 << x); 1684 } 1685 break; 1686 1687 case O_TCPDATALEN: 1688 if (proto == IPPROTO_TCP && offset == 0) { 1689 struct tcphdr *tcp; 1690 uint16_t x; 1691 uint16_t *p; 1692 int i; 1693 1694 tcp = TCP(ulp); 1695 x = iplen - 1696 ((ip->ip_hl + tcp->th_off) << 2); 1697 if (cmdlen == 1) { 1698 match = (cmd->arg1 == x); 1699 break; 1700 } 1701 /* otherwise we have ranges */ 1702 p = ((ipfw_insn_u16 *)cmd)->ports; 1703 i = cmdlen - 1; 1704 for (; !match && i>0; i--, p += 2) 1705 match = (x >= p[0] && x <= p[1]); 1706 } 1707 break; 1708 1709 case O_TCPFLAGS: 1710 match = (proto == IPPROTO_TCP && offset == 0 && 1711 flags_match(cmd, TCP(ulp)->th_flags)); 1712 break; 1713 1714 case O_TCPOPTS: 1715 PULLUP_LEN(hlen, ulp, (TCP(ulp)->th_off << 2)); 1716 match = (proto == IPPROTO_TCP && offset == 0 && 1717 tcpopts_match(TCP(ulp), cmd)); 1718 break; 1719 1720 case O_TCPSEQ: 1721 match = (proto == IPPROTO_TCP && offset == 0 && 1722 ((ipfw_insn_u32 *)cmd)->d[0] == 1723 TCP(ulp)->th_seq); 1724 break; 1725 1726 case O_TCPACK: 1727 match = (proto == IPPROTO_TCP && offset == 0 && 1728 ((ipfw_insn_u32 *)cmd)->d[0] == 1729 TCP(ulp)->th_ack); 1730 break; 1731 1732 case O_TCPWIN: 1733 if (proto == IPPROTO_TCP && offset == 0) { 1734 uint16_t x; 1735 uint16_t *p; 1736 int i; 1737 1738 x = ntohs(TCP(ulp)->th_win); 1739 if (cmdlen == 1) { 1740 match = (cmd->arg1 == x); 1741 break; 1742 } 1743 /* Otherwise we have ranges. */ 1744 p = ((ipfw_insn_u16 *)cmd)->ports; 1745 i = cmdlen - 1; 1746 for (; !match && i > 0; i--, p += 2) 1747 match = (x >= p[0] && x <= p[1]); 1748 } 1749 break; 1750 1751 case O_ESTAB: 1752 /* reject packets which have SYN only */ 1753 /* XXX should i also check for TH_ACK ? */ 1754 match = (proto == IPPROTO_TCP && offset == 0 && 1755 (TCP(ulp)->th_flags & 1756 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 1757 break; 1758 1759 case O_ALTQ: { 1760 struct pf_mtag *at; 1761 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 1762 1763 match = 1; 1764 at = pf_find_mtag(m); 1765 if (at != NULL && at->qid != 0) 1766 break; 1767 at = pf_get_mtag(m); 1768 if (at == NULL) { 1769 /* 1770 * Let the packet fall back to the 1771 * default ALTQ. 1772 */ 1773 break; 1774 } 1775 at->qid = altq->qid; 1776 at->hdr = ip; 1777 break; 1778 } 1779 1780 case O_LOG: 1781 ipfw_log(f, hlen, args, m, 1782 oif, offset | ip6f_mf, tablearg, ip); 1783 match = 1; 1784 break; 1785 1786 case O_PROB: 1787 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 1788 break; 1789 1790 case O_VERREVPATH: 1791 /* Outgoing packets automatically pass/match */ 1792 match = ((oif != NULL) || 1793 (m->m_pkthdr.rcvif == NULL) || 1794 ( 1795#ifdef INET6 1796 is_ipv6 ? 1797 verify_path6(&(args->f_id.src_ip6), 1798 m->m_pkthdr.rcvif, args->f_id.fib) : 1799#endif 1800 verify_path(src_ip, m->m_pkthdr.rcvif, 1801 args->f_id.fib))); 1802 break; 1803 1804 case O_VERSRCREACH: 1805 /* Outgoing packets automatically pass/match */ 1806 match = (hlen > 0 && ((oif != NULL) || 1807#ifdef INET6 1808 is_ipv6 ? 1809 verify_path6(&(args->f_id.src_ip6), 1810 NULL, args->f_id.fib) : 1811#endif 1812 verify_path(src_ip, NULL, args->f_id.fib))); 1813 break; 1814 1815 case O_ANTISPOOF: 1816 /* Outgoing packets automatically pass/match */ 1817 if (oif == NULL && hlen > 0 && 1818 ( (is_ipv4 && in_localaddr(src_ip)) 1819#ifdef INET6 1820 || (is_ipv6 && 1821 in6_localaddr(&(args->f_id.src_ip6))) 1822#endif 1823 )) 1824 match = 1825#ifdef INET6 1826 is_ipv6 ? verify_path6( 1827 &(args->f_id.src_ip6), 1828 m->m_pkthdr.rcvif, 1829 args->f_id.fib) : 1830#endif 1831 verify_path(src_ip, 1832 m->m_pkthdr.rcvif, 1833 args->f_id.fib); 1834 else 1835 match = 1; 1836 break; 1837 1838 case O_IPSEC: 1839#ifdef IPSEC 1840 match = (m_tag_find(m, 1841 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 1842#endif 1843 /* otherwise no match */ 1844 break; 1845 1846#ifdef INET6 1847 case O_IP6_SRC: 1848 match = is_ipv6 && 1849 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 1850 &((ipfw_insn_ip6 *)cmd)->addr6); 1851 break; 1852 1853 case O_IP6_DST: 1854 match = is_ipv6 && 1855 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 1856 &((ipfw_insn_ip6 *)cmd)->addr6); 1857 break; 1858 case O_IP6_SRC_MASK: 1859 case O_IP6_DST_MASK: 1860 if (is_ipv6) { 1861 int i = cmdlen - 1; 1862 struct in6_addr p; 1863 struct in6_addr *d = 1864 &((ipfw_insn_ip6 *)cmd)->addr6; 1865 1866 for (; !match && i > 0; d += 2, 1867 i -= F_INSN_SIZE(struct in6_addr) 1868 * 2) { 1869 p = (cmd->opcode == 1870 O_IP6_SRC_MASK) ? 1871 args->f_id.src_ip6: 1872 args->f_id.dst_ip6; 1873 APPLY_MASK(&p, &d[1]); 1874 match = 1875 IN6_ARE_ADDR_EQUAL(&d[0], 1876 &p); 1877 } 1878 } 1879 break; 1880 1881 case O_FLOW6ID: 1882 match = is_ipv6 && 1883 flow6id_match(args->f_id.flow_id6, 1884 (ipfw_insn_u32 *) cmd); 1885 break; 1886 1887 case O_EXT_HDR: 1888 match = is_ipv6 && 1889 (ext_hd & ((ipfw_insn *) cmd)->arg1); 1890 break; 1891 1892 case O_IP6: 1893 match = is_ipv6; 1894 break; 1895#endif 1896 1897 case O_IP4: 1898 match = is_ipv4; 1899 break; 1900 1901 case O_TAG: { 1902 struct m_tag *mtag; 1903 uint32_t tag = IP_FW_ARG_TABLEARG(cmd->arg1); 1904 1905 /* Packet is already tagged with this tag? */ 1906 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 1907 1908 /* We have `untag' action when F_NOT flag is 1909 * present. And we must remove this mtag from 1910 * mbuf and reset `match' to zero (`match' will 1911 * be inversed later). 1912 * Otherwise we should allocate new mtag and 1913 * push it into mbuf. 1914 */ 1915 if (cmd->len & F_NOT) { /* `untag' action */ 1916 if (mtag != NULL) 1917 m_tag_delete(m, mtag); 1918 match = 0; 1919 } else { 1920 if (mtag == NULL) { 1921 mtag = m_tag_alloc( MTAG_IPFW, 1922 tag, 0, M_NOWAIT); 1923 if (mtag != NULL) 1924 m_tag_prepend(m, mtag); 1925 } 1926 match = 1; 1927 } 1928 break; 1929 } 1930 1931 case O_FIB: /* try match the specified fib */ 1932 if (args->f_id.fib == cmd->arg1) 1933 match = 1; 1934 break; 1935 1936 case O_SOCKARG: { 1937 struct inpcb *inp = args->inp; 1938 struct inpcbinfo *pi; 1939 1940 if (is_ipv6) /* XXX can we remove this ? */ 1941 break; 1942 1943 if (proto == IPPROTO_TCP) 1944 pi = &V_tcbinfo; 1945 else if (proto == IPPROTO_UDP) 1946 pi = &V_udbinfo; 1947 else 1948 break; 1949 1950 /* 1951 * XXXRW: so_user_cookie should almost 1952 * certainly be inp_user_cookie? 1953 */ 1954 1955 /* For incomming packet, lookup up the 1956 inpcb using the src/dest ip/port tuple */ 1957 if (inp == NULL) { 1958 inp = in_pcblookup(pi, 1959 src_ip, htons(src_port), 1960 dst_ip, htons(dst_port), 1961 INPLOOKUP_RLOCKPCB, NULL); 1962 if (inp != NULL) { 1963 tablearg = 1964 inp->inp_socket->so_user_cookie; 1965 if (tablearg) 1966 match = 1; 1967 INP_RUNLOCK(inp); 1968 } 1969 } else { 1970 if (inp->inp_socket) { 1971 tablearg = 1972 inp->inp_socket->so_user_cookie; 1973 if (tablearg) 1974 match = 1; 1975 } 1976 } 1977 break; 1978 } 1979 1980 case O_TAGGED: { 1981 struct m_tag *mtag; 1982 uint32_t tag = IP_FW_ARG_TABLEARG(cmd->arg1); 1983 1984 if (cmdlen == 1) { 1985 match = m_tag_locate(m, MTAG_IPFW, 1986 tag, NULL) != NULL; 1987 break; 1988 } 1989 1990 /* we have ranges */ 1991 for (mtag = m_tag_first(m); 1992 mtag != NULL && !match; 1993 mtag = m_tag_next(m, mtag)) { 1994 uint16_t *p; 1995 int i; 1996 1997 if (mtag->m_tag_cookie != MTAG_IPFW) 1998 continue; 1999 2000 p = ((ipfw_insn_u16 *)cmd)->ports; 2001 i = cmdlen - 1; 2002 for(; !match && i > 0; i--, p += 2) 2003 match = 2004 mtag->m_tag_id >= p[0] && 2005 mtag->m_tag_id <= p[1]; 2006 } 2007 break; 2008 } 2009 2010 /* 2011 * The second set of opcodes represents 'actions', 2012 * i.e. the terminal part of a rule once the packet 2013 * matches all previous patterns. 2014 * Typically there is only one action for each rule, 2015 * and the opcode is stored at the end of the rule 2016 * (but there are exceptions -- see below). 2017 * 2018 * In general, here we set retval and terminate the 2019 * outer loop (would be a 'break 3' in some language, 2020 * but we need to set l=0, done=1) 2021 * 2022 * Exceptions: 2023 * O_COUNT and O_SKIPTO actions: 2024 * instead of terminating, we jump to the next rule 2025 * (setting l=0), or to the SKIPTO target (setting 2026 * f/f_len, cmd and l as needed), respectively. 2027 * 2028 * O_TAG, O_LOG and O_ALTQ action parameters: 2029 * perform some action and set match = 1; 2030 * 2031 * O_LIMIT and O_KEEP_STATE: these opcodes are 2032 * not real 'actions', and are stored right 2033 * before the 'action' part of the rule. 2034 * These opcodes try to install an entry in the 2035 * state tables; if successful, we continue with 2036 * the next opcode (match=1; break;), otherwise 2037 * the packet must be dropped (set retval, 2038 * break loops with l=0, done=1) 2039 * 2040 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2041 * cause a lookup of the state table, and a jump 2042 * to the 'action' part of the parent rule 2043 * if an entry is found, or 2044 * (CHECK_STATE only) a jump to the next rule if 2045 * the entry is not found. 2046 * The result of the lookup is cached so that 2047 * further instances of these opcodes become NOPs. 2048 * The jump to the next rule is done by setting 2049 * l=0, cmdlen=0. 2050 */ 2051 case O_LIMIT: 2052 case O_KEEP_STATE: 2053 if (ipfw_install_state(f, 2054 (ipfw_insn_limit *)cmd, args, tablearg)) { 2055 /* error or limit violation */ 2056 retval = IP_FW_DENY; 2057 l = 0; /* exit inner loop */ 2058 done = 1; /* exit outer loop */ 2059 } 2060 match = 1; 2061 break; 2062 2063 case O_PROBE_STATE: 2064 case O_CHECK_STATE: 2065 /* 2066 * dynamic rules are checked at the first 2067 * keep-state or check-state occurrence, 2068 * with the result being stored in dyn_dir. 2069 * The compiler introduces a PROBE_STATE 2070 * instruction for us when we have a 2071 * KEEP_STATE (because PROBE_STATE needs 2072 * to be run first). 2073 */ 2074 if (dyn_dir == MATCH_UNKNOWN && 2075 (q = ipfw_lookup_dyn_rule(&args->f_id, 2076 &dyn_dir, proto == IPPROTO_TCP ? 2077 TCP(ulp) : NULL)) 2078 != NULL) { 2079 /* 2080 * Found dynamic entry, update stats 2081 * and jump to the 'action' part of 2082 * the parent rule by setting 2083 * f, cmd, l and clearing cmdlen. 2084 */ 2085 IPFW_INC_DYN_COUNTER(q, pktlen); 2086 /* XXX we would like to have f_pos 2087 * readily accessible in the dynamic 2088 * rule, instead of having to 2089 * lookup q->rule. 2090 */ 2091 f = q->rule; 2092 f_pos = ipfw_find_rule(chain, 2093 f->rulenum, f->id); 2094 cmd = ACTION_PTR(f); 2095 l = f->cmd_len - f->act_ofs; 2096 ipfw_dyn_unlock(q); 2097 cmdlen = 0; 2098 match = 1; 2099 break; 2100 } 2101 /* 2102 * Dynamic entry not found. If CHECK_STATE, 2103 * skip to next rule, if PROBE_STATE just 2104 * ignore and continue with next opcode. 2105 */ 2106 if (cmd->opcode == O_CHECK_STATE) 2107 l = 0; /* exit inner loop */ 2108 match = 1; 2109 break; 2110 2111 case O_ACCEPT: 2112 retval = 0; /* accept */ 2113 l = 0; /* exit inner loop */ 2114 done = 1; /* exit outer loop */ 2115 break; 2116 2117 case O_PIPE: 2118 case O_QUEUE: 2119 set_match(args, f_pos, chain); 2120 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1); 2121 if (cmd->opcode == O_PIPE) 2122 args->rule.info |= IPFW_IS_PIPE; 2123 if (V_fw_one_pass) 2124 args->rule.info |= IPFW_ONEPASS; 2125 retval = IP_FW_DUMMYNET; 2126 l = 0; /* exit inner loop */ 2127 done = 1; /* exit outer loop */ 2128 break; 2129 2130 case O_DIVERT: 2131 case O_TEE: 2132 if (args->eh) /* not on layer 2 */ 2133 break; 2134 /* otherwise this is terminal */ 2135 l = 0; /* exit inner loop */ 2136 done = 1; /* exit outer loop */ 2137 retval = (cmd->opcode == O_DIVERT) ? 2138 IP_FW_DIVERT : IP_FW_TEE; 2139 set_match(args, f_pos, chain); 2140 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1); 2141 break; 2142 2143 case O_COUNT: 2144 IPFW_INC_RULE_COUNTER(f, pktlen); 2145 l = 0; /* exit inner loop */ 2146 break; 2147 2148 case O_SKIPTO: 2149 IPFW_INC_RULE_COUNTER(f, pktlen); 2150 f_pos = jump_fast(chain, f, cmd->arg1, tablearg, 0); 2151 /* 2152 * Skip disabled rules, and re-enter 2153 * the inner loop with the correct 2154 * f_pos, f, l and cmd. 2155 * Also clear cmdlen and skip_or 2156 */ 2157 for (; f_pos < chain->n_rules - 1 && 2158 (V_set_disable & 2159 (1 << chain->map[f_pos]->set)); 2160 f_pos++) 2161 ; 2162 /* Re-enter the inner loop at the skipto rule. */ 2163 f = chain->map[f_pos]; 2164 l = f->cmd_len; 2165 cmd = f->cmd; 2166 match = 1; 2167 cmdlen = 0; 2168 skip_or = 0; 2169 continue; 2170 break; /* not reached */ 2171 2172 case O_CALLRETURN: { 2173 /* 2174 * Implementation of `subroutine' call/return, 2175 * in the stack carried in an mbuf tag. This 2176 * is different from `skipto' in that any call 2177 * address is possible (`skipto' must prevent 2178 * backward jumps to avoid endless loops). 2179 * We have `return' action when F_NOT flag is 2180 * present. The `m_tag_id' field is used as 2181 * stack pointer. 2182 */ 2183 struct m_tag *mtag; 2184 uint16_t jmpto, *stack; 2185 2186#define IS_CALL ((cmd->len & F_NOT) == 0) 2187#define IS_RETURN ((cmd->len & F_NOT) != 0) 2188 /* 2189 * Hand-rolled version of m_tag_locate() with 2190 * wildcard `type'. 2191 * If not already tagged, allocate new tag. 2192 */ 2193 mtag = m_tag_first(m); 2194 while (mtag != NULL) { 2195 if (mtag->m_tag_cookie == 2196 MTAG_IPFW_CALL) 2197 break; 2198 mtag = m_tag_next(m, mtag); 2199 } 2200 if (mtag == NULL && IS_CALL) { 2201 mtag = m_tag_alloc(MTAG_IPFW_CALL, 0, 2202 IPFW_CALLSTACK_SIZE * 2203 sizeof(uint16_t), M_NOWAIT); 2204 if (mtag != NULL) 2205 m_tag_prepend(m, mtag); 2206 } 2207 2208 /* 2209 * On error both `call' and `return' just 2210 * continue with next rule. 2211 */ 2212 if (IS_RETURN && (mtag == NULL || 2213 mtag->m_tag_id == 0)) { 2214 l = 0; /* exit inner loop */ 2215 break; 2216 } 2217 if (IS_CALL && (mtag == NULL || 2218 mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) { 2219 printf("ipfw: call stack error, " 2220 "go to next rule\n"); 2221 l = 0; /* exit inner loop */ 2222 break; 2223 } 2224 2225 IPFW_INC_RULE_COUNTER(f, pktlen); 2226 stack = (uint16_t *)(mtag + 1); 2227 2228 /* 2229 * The `call' action may use cached f_pos 2230 * (in f->next_rule), whose version is written 2231 * in f->next_rule. 2232 * The `return' action, however, doesn't have 2233 * fixed jump address in cmd->arg1 and can't use 2234 * cache. 2235 */ 2236 if (IS_CALL) { 2237 stack[mtag->m_tag_id] = f->rulenum; 2238 mtag->m_tag_id++; 2239 f_pos = jump_fast(chain, f, cmd->arg1, 2240 tablearg, 1); 2241 } else { /* `return' action */ 2242 mtag->m_tag_id--; 2243 jmpto = stack[mtag->m_tag_id] + 1; 2244 f_pos = ipfw_find_rule(chain, jmpto, 0); 2245 } 2246 2247 /* 2248 * Skip disabled rules, and re-enter 2249 * the inner loop with the correct 2250 * f_pos, f, l and cmd. 2251 * Also clear cmdlen and skip_or 2252 */ 2253 for (; f_pos < chain->n_rules - 1 && 2254 (V_set_disable & 2255 (1 << chain->map[f_pos]->set)); f_pos++) 2256 ; 2257 /* Re-enter the inner loop at the dest rule. */ 2258 f = chain->map[f_pos]; 2259 l = f->cmd_len; 2260 cmd = f->cmd; 2261 cmdlen = 0; 2262 skip_or = 0; 2263 continue; 2264 break; /* NOTREACHED */ 2265 } 2266#undef IS_CALL 2267#undef IS_RETURN 2268 2269 case O_REJECT: 2270 /* 2271 * Drop the packet and send a reject notice 2272 * if the packet is not ICMP (or is an ICMP 2273 * query), and it is not multicast/broadcast. 2274 */ 2275 if (hlen > 0 && is_ipv4 && offset == 0 && 2276 (proto != IPPROTO_ICMP || 2277 is_icmp_query(ICMP(ulp))) && 2278 !(m->m_flags & (M_BCAST|M_MCAST)) && 2279 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 2280 send_reject(args, cmd->arg1, iplen, ip); 2281 m = args->m; 2282 } 2283 /* FALLTHROUGH */ 2284#ifdef INET6 2285 case O_UNREACH6: 2286 if (hlen > 0 && is_ipv6 && 2287 ((offset & IP6F_OFF_MASK) == 0) && 2288 (proto != IPPROTO_ICMPV6 || 2289 (is_icmp6_query(icmp6_type) == 1)) && 2290 !(m->m_flags & (M_BCAST|M_MCAST)) && 2291 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 2292 send_reject6( 2293 args, cmd->arg1, hlen, 2294 (struct ip6_hdr *)ip); 2295 m = args->m; 2296 } 2297 /* FALLTHROUGH */ 2298#endif 2299 case O_DENY: 2300 retval = IP_FW_DENY; 2301 l = 0; /* exit inner loop */ 2302 done = 1; /* exit outer loop */ 2303 break; 2304 2305 case O_FORWARD_IP: 2306 if (args->eh) /* not valid on layer2 pkts */ 2307 break; 2308 if (q == NULL || q->rule != f || 2309 dyn_dir == MATCH_FORWARD) { 2310 struct sockaddr_in *sa; 2311 sa = &(((ipfw_insn_sa *)cmd)->sa); 2312 if (sa->sin_addr.s_addr == INADDR_ANY) { 2313 bcopy(sa, &args->hopstore, 2314 sizeof(*sa)); 2315 args->hopstore.sin_addr.s_addr = 2316 htonl(tablearg); 2317 args->next_hop = &args->hopstore; 2318 } else { 2319 args->next_hop = sa; 2320 } 2321 } 2322 retval = IP_FW_PASS; 2323 l = 0; /* exit inner loop */ 2324 done = 1; /* exit outer loop */ 2325 break; 2326 2327#ifdef INET6 2328 case O_FORWARD_IP6: 2329 if (args->eh) /* not valid on layer2 pkts */ 2330 break; 2331 if (q == NULL || q->rule != f || 2332 dyn_dir == MATCH_FORWARD) { 2333 struct sockaddr_in6 *sin6; 2334 2335 sin6 = &(((ipfw_insn_sa6 *)cmd)->sa); 2336 args->next_hop6 = sin6; 2337 } 2338 retval = IP_FW_PASS; 2339 l = 0; /* exit inner loop */ 2340 done = 1; /* exit outer loop */ 2341 break; 2342#endif 2343 2344 case O_NETGRAPH: 2345 case O_NGTEE: 2346 set_match(args, f_pos, chain); 2347 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1); 2348 if (V_fw_one_pass) 2349 args->rule.info |= IPFW_ONEPASS; 2350 retval = (cmd->opcode == O_NETGRAPH) ? 2351 IP_FW_NETGRAPH : IP_FW_NGTEE; 2352 l = 0; /* exit inner loop */ 2353 done = 1; /* exit outer loop */ 2354 break; 2355 2356 case O_SETFIB: { 2357 uint32_t fib; 2358 2359 IPFW_INC_RULE_COUNTER(f, pktlen); 2360 fib = IP_FW_ARG_TABLEARG(cmd->arg1); 2361 if (fib >= rt_numfibs) 2362 fib = 0; 2363 M_SETFIB(m, fib); 2364 args->f_id.fib = fib; 2365 l = 0; /* exit inner loop */ 2366 break; 2367 } 2368 2369 case O_SETDSCP: { 2370 uint16_t code; 2371 2372 code = IP_FW_ARG_TABLEARG(cmd->arg1) & 0x3F; 2373 l = 0; /* exit inner loop */ 2374 if (is_ipv4) { 2375 uint16_t a; 2376 2377 a = ip->ip_tos; 2378 ip->ip_tos = (code << 2) | (ip->ip_tos & 0x03); 2379 a += ntohs(ip->ip_sum) - ip->ip_tos; 2380 ip->ip_sum = htons(a); 2381 } else if (is_ipv6) { 2382 uint8_t *v; 2383 2384 v = &((struct ip6_hdr *)ip)->ip6_vfc; 2385 *v = (*v & 0xF0) | (code >> 2); 2386 v++; 2387 *v = (*v & 0x3F) | ((code & 0x03) << 6); 2388 } else 2389 break; 2390 2391 IPFW_INC_RULE_COUNTER(f, pktlen); 2392 break; 2393 } 2394 2395 case O_NAT: 2396 if (!IPFW_NAT_LOADED) { 2397 retval = IP_FW_DENY; 2398 } else { 2399 struct cfg_nat *t; 2400 int nat_id; 2401 2402 set_match(args, f_pos, chain); 2403 /* Check if this is 'global' nat rule */ 2404 if (cmd->arg1 == 0) { 2405 retval = ipfw_nat_ptr(args, NULL, m); 2406 l = 0; 2407 done = 1; 2408 break; 2409 } 2410 t = ((ipfw_insn_nat *)cmd)->nat; 2411 if (t == NULL) { 2412 nat_id = IP_FW_ARG_TABLEARG(cmd->arg1); 2413 t = (*lookup_nat_ptr)(&chain->nat, nat_id); 2414 2415 if (t == NULL) { 2416 retval = IP_FW_DENY; 2417 l = 0; /* exit inner loop */ 2418 done = 1; /* exit outer loop */ 2419 break; 2420 } 2421 if (cmd->arg1 != IP_FW_TABLEARG) 2422 ((ipfw_insn_nat *)cmd)->nat = t; 2423 } 2424 retval = ipfw_nat_ptr(args, t, m); 2425 } 2426 l = 0; /* exit inner loop */ 2427 done = 1; /* exit outer loop */ 2428 break; 2429 2430 case O_REASS: { 2431 int ip_off; 2432 2433 IPFW_INC_RULE_COUNTER(f, pktlen); 2434 l = 0; /* in any case exit inner loop */ 2435 ip_off = ntohs(ip->ip_off); 2436 2437 /* if not fragmented, go to next rule */ 2438 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0) 2439 break; 2440 /* 2441 * ip_reass() expects len & off in host 2442 * byte order. 2443 */ 2444 SET_HOST_IPLEN(ip); 2445 2446 args->m = m = ip_reass(m); 2447 2448 /* 2449 * do IP header checksum fixup. 2450 */ 2451 if (m == NULL) { /* fragment got swallowed */ 2452 retval = IP_FW_DENY; 2453 } else { /* good, packet complete */ 2454 int hlen; 2455 2456 ip = mtod(m, struct ip *); 2457 hlen = ip->ip_hl << 2; 2458 SET_NET_IPLEN(ip); 2459 ip->ip_sum = 0; 2460 if (hlen == sizeof(struct ip)) 2461 ip->ip_sum = in_cksum_hdr(ip); 2462 else 2463 ip->ip_sum = in_cksum(m, hlen); 2464 retval = IP_FW_REASS; 2465 set_match(args, f_pos, chain); 2466 } 2467 done = 1; /* exit outer loop */ 2468 break; 2469 } 2470 2471 default: 2472 panic("-- unknown opcode %d\n", cmd->opcode); 2473 } /* end of switch() on opcodes */ 2474 /* 2475 * if we get here with l=0, then match is irrelevant. 2476 */ 2477 2478 if (cmd->len & F_NOT) 2479 match = !match; 2480 2481 if (match) { 2482 if (cmd->len & F_OR) 2483 skip_or = 1; 2484 } else { 2485 if (!(cmd->len & F_OR)) /* not an OR block, */ 2486 break; /* try next rule */ 2487 } 2488 2489 } /* end of inner loop, scan opcodes */ 2490#undef PULLUP_LEN 2491 2492 if (done) 2493 break; 2494 2495/* next_rule:; */ /* try next rule */ 2496 2497 } /* end of outer for, scan rules */ 2498 2499 if (done) { 2500 struct ip_fw *rule = chain->map[f_pos]; 2501 /* Update statistics */ 2502 IPFW_INC_RULE_COUNTER(rule, pktlen); 2503 } else { 2504 retval = IP_FW_DENY; 2505 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 2506 } 2507 IPFW_RUNLOCK(chain); 2508#ifdef __FreeBSD__ 2509 if (ucred_cache != NULL) 2510 crfree(ucred_cache); 2511#endif 2512 return (retval); 2513 2514pullup_failed: 2515 if (V_fw_verbose) 2516 printf("ipfw: pullup failed\n"); 2517 return (IP_FW_DENY); 2518} 2519 2520/* 2521 * Set maximum number of tables that can be used in given VNET ipfw instance. 2522 */ 2523#ifdef SYSCTL_NODE 2524static int 2525sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS) 2526{ 2527 int error; 2528 unsigned int ntables; 2529 2530 ntables = V_fw_tables_max; 2531 2532 error = sysctl_handle_int(oidp, &ntables, 0, req); 2533 /* Read operation or some error */ 2534 if ((error != 0) || (req->newptr == NULL)) 2535 return (error); 2536 2537 return (ipfw_resize_tables(&V_layer3_chain, ntables)); 2538} 2539#endif 2540/* 2541 * Module and VNET glue 2542 */ 2543 2544/* 2545 * Stuff that must be initialised only on boot or module load 2546 */ 2547static int 2548ipfw_init(void) 2549{ 2550 int error = 0; 2551 2552 /* 2553 * Only print out this stuff the first time around, 2554 * when called from the sysinit code. 2555 */ 2556 printf("ipfw2 " 2557#ifdef INET6 2558 "(+ipv6) " 2559#endif 2560 "initialized, divert %s, nat %s, " 2561 "default to %s, logging ", 2562#ifdef IPDIVERT 2563 "enabled", 2564#else 2565 "loadable", 2566#endif 2567#ifdef IPFIREWALL_NAT 2568 "enabled", 2569#else 2570 "loadable", 2571#endif 2572 default_to_accept ? "accept" : "deny"); 2573 2574 /* 2575 * Note: V_xxx variables can be accessed here but the vnet specific 2576 * initializer may not have been called yet for the VIMAGE case. 2577 * Tuneables will have been processed. We will print out values for 2578 * the default vnet. 2579 * XXX This should all be rationalized AFTER 8.0 2580 */ 2581 if (V_fw_verbose == 0) 2582 printf("disabled\n"); 2583 else if (V_verbose_limit == 0) 2584 printf("unlimited\n"); 2585 else 2586 printf("limited to %d packets/entry by default\n", 2587 V_verbose_limit); 2588 2589 /* Check user-supplied table count for validness */ 2590 if (default_fw_tables > IPFW_TABLES_MAX) 2591 default_fw_tables = IPFW_TABLES_MAX; 2592 2593 ipfw_log_bpf(1); /* init */ 2594 return (error); 2595} 2596 2597/* 2598 * Called for the removal of the last instance only on module unload. 2599 */ 2600static void 2601ipfw_destroy(void) 2602{ 2603 2604 ipfw_log_bpf(0); /* uninit */ 2605 printf("IP firewall unloaded\n"); 2606} 2607 2608/* 2609 * Stuff that must be initialized for every instance 2610 * (including the first of course). 2611 */ 2612static int 2613vnet_ipfw_init(const void *unused) 2614{ 2615 int error; 2616 struct ip_fw *rule = NULL; 2617 struct ip_fw_chain *chain; 2618 2619 chain = &V_layer3_chain; 2620 2621 /* First set up some values that are compile time options */ 2622 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 2623 V_fw_deny_unknown_exthdrs = 1; 2624#ifdef IPFIREWALL_VERBOSE 2625 V_fw_verbose = 1; 2626#endif 2627#ifdef IPFIREWALL_VERBOSE_LIMIT 2628 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 2629#endif 2630#ifdef IPFIREWALL_NAT 2631 LIST_INIT(&chain->nat); 2632#endif 2633 2634 /* insert the default rule and create the initial map */ 2635 chain->n_rules = 1; 2636 chain->static_len = sizeof(struct ip_fw); 2637 chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_WAITOK | M_ZERO); 2638 if (chain->map) 2639 rule = malloc(chain->static_len, M_IPFW, M_WAITOK | M_ZERO); 2640 2641 /* Set initial number of tables */ 2642 V_fw_tables_max = default_fw_tables; 2643 error = ipfw_init_tables(chain); 2644 if (error) { 2645 printf("ipfw2: setting up tables failed\n"); 2646 free(chain->map, M_IPFW); 2647 free(rule, M_IPFW); 2648 return (ENOSPC); 2649 } 2650 2651 /* fill and insert the default rule */ 2652 rule->act_ofs = 0; 2653 rule->rulenum = IPFW_DEFAULT_RULE; 2654 rule->cmd_len = 1; 2655 rule->set = RESVD_SET; 2656 rule->cmd[0].len = 1; 2657 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY; 2658 chain->rules = chain->default_rule = chain->map[0] = rule; 2659 chain->id = rule->id = 1; 2660 2661 IPFW_LOCK_INIT(chain); 2662 ipfw_dyn_init(chain); 2663 2664 /* First set up some values that are compile time options */ 2665 V_ipfw_vnet_ready = 1; /* Open for business */ 2666 2667 /* 2668 * Hook the sockopt handler, and the layer2 (V_ip_fw_chk_ptr) 2669 * and pfil hooks for ipv4 and ipv6. Even if the latter two fail 2670 * we still keep the module alive because the sockopt and 2671 * layer2 paths are still useful. 2672 * ipfw[6]_hook return 0 on success, ENOENT on failure, 2673 * so we can ignore the exact return value and just set a flag. 2674 * 2675 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so 2676 * changes in the underlying (per-vnet) variables trigger 2677 * immediate hook()/unhook() calls. 2678 * In layer2 we have the same behaviour, except that V_ether_ipfw 2679 * is checked on each packet because there are no pfil hooks. 2680 */ 2681 V_ip_fw_ctl_ptr = ipfw_ctl; 2682 V_ip_fw_chk_ptr = ipfw_chk; 2683 error = ipfw_attach_hooks(1); 2684 return (error); 2685} 2686 2687/* 2688 * Called for the removal of each instance. 2689 */ 2690static int 2691vnet_ipfw_uninit(const void *unused) 2692{ 2693 struct ip_fw *reap, *rule; 2694 struct ip_fw_chain *chain = &V_layer3_chain; 2695 int i; 2696 2697 V_ipfw_vnet_ready = 0; /* tell new callers to go away */ 2698 /* 2699 * disconnect from ipv4, ipv6, layer2 and sockopt. 2700 * Then grab, release and grab again the WLOCK so we make 2701 * sure the update is propagated and nobody will be in. 2702 */ 2703 (void)ipfw_attach_hooks(0 /* detach */); 2704 V_ip_fw_chk_ptr = NULL; 2705 V_ip_fw_ctl_ptr = NULL; 2706 IPFW_UH_WLOCK(chain); 2707 IPFW_UH_WUNLOCK(chain); 2708 IPFW_UH_WLOCK(chain); 2709 2710 IPFW_WLOCK(chain); 2711 ipfw_dyn_uninit(0); /* run the callout_drain */ 2712 IPFW_WUNLOCK(chain); 2713 2714 ipfw_destroy_tables(chain); 2715 reap = NULL; 2716 IPFW_WLOCK(chain); 2717 for (i = 0; i < chain->n_rules; i++) { 2718 rule = chain->map[i]; 2719 rule->x_next = reap; 2720 reap = rule; 2721 } 2722 if (chain->map) 2723 free(chain->map, M_IPFW); 2724 IPFW_WUNLOCK(chain); 2725 IPFW_UH_WUNLOCK(chain); 2726 if (reap != NULL) 2727 ipfw_reap_rules(reap); 2728 IPFW_LOCK_DESTROY(chain); 2729 ipfw_dyn_uninit(1); /* free the remaining parts */ 2730 return 0; 2731} 2732 2733/* 2734 * Module event handler. 2735 * In general we have the choice of handling most of these events by the 2736 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to 2737 * use the SYSINIT handlers as they are more capable of expressing the 2738 * flow of control during module and vnet operations, so this is just 2739 * a skeleton. Note there is no SYSINIT equivalent of the module 2740 * SHUTDOWN handler, but we don't have anything to do in that case anyhow. 2741 */ 2742static int 2743ipfw_modevent(module_t mod, int type, void *unused) 2744{ 2745 int err = 0; 2746 2747 switch (type) { 2748 case MOD_LOAD: 2749 /* Called once at module load or 2750 * system boot if compiled in. */ 2751 break; 2752 case MOD_QUIESCE: 2753 /* Called before unload. May veto unloading. */ 2754 break; 2755 case MOD_UNLOAD: 2756 /* Called during unload. */ 2757 break; 2758 case MOD_SHUTDOWN: 2759 /* Called during system shutdown. */ 2760 break; 2761 default: 2762 err = EOPNOTSUPP; 2763 break; 2764 } 2765 return err; 2766} 2767 2768static moduledata_t ipfwmod = { 2769 "ipfw", 2770 ipfw_modevent, 2771 0 2772}; 2773 2774/* Define startup order. */ 2775#define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_IFATTACHDOMAIN 2776#define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */ 2777#define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */ 2778#define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */ 2779 2780DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER); 2781MODULE_VERSION(ipfw, 2); 2782/* should declare some dependencies here */ 2783 2784/* 2785 * Starting up. Done in order after ipfwmod() has been called. 2786 * VNET_SYSINIT is also called for each existing vnet and each new vnet. 2787 */ 2788SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 2789 ipfw_init, NULL); 2790VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 2791 vnet_ipfw_init, NULL); 2792 2793/* 2794 * Closing up shop. These are done in REVERSE ORDER, but still 2795 * after ipfwmod() has been called. Not called on reboot. 2796 * VNET_SYSUNINIT is also called for each exiting vnet as it exits. 2797 * or when the module is unloaded. 2798 */ 2799SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 2800 ipfw_destroy, NULL); 2801VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 2802 vnet_ipfw_uninit, NULL); 2803/* end of file */ 2804