ip_fw2.c revision 201527
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: head/sys/netinet/ipfw/ip_fw2.c 201527 2010-01-04 19:01:22Z luigi $"); 28 29/* 30 * The FreeBSD IP packet firewall, main file 31 */ 32 33#if !defined(KLD_MODULE) 34#include "opt_ipfw.h" 35#include "opt_ipdivert.h" 36#include "opt_ipdn.h" 37#include "opt_inet.h" 38#ifndef INET 39#error IPFIREWALL requires INET. 40#endif /* INET */ 41#endif 42#include "opt_inet6.h" 43#include "opt_ipsec.h" 44 45#include <sys/param.h> 46#include <sys/systm.h> 47#include <sys/condvar.h> 48#include <sys/eventhandler.h> 49#include <sys/malloc.h> 50#include <sys/mbuf.h> 51#include <sys/kernel.h> 52#include <sys/lock.h> 53#include <sys/jail.h> 54#include <sys/module.h> 55#include <sys/priv.h> 56#include <sys/proc.h> 57#include <sys/rwlock.h> 58#include <sys/socket.h> 59#include <sys/socketvar.h> 60#include <sys/sysctl.h> 61#include <sys/syslog.h> 62#include <sys/ucred.h> 63#include <net/ethernet.h> /* for ETHERTYPE_IP */ 64#include <net/if.h> 65#include <net/route.h> 66#include <net/pf_mtag.h> 67#include <net/vnet.h> 68 69#include <netinet/in.h> 70#include <netinet/in_var.h> 71#include <netinet/in_pcb.h> 72#include <netinet/ip.h> 73#include <netinet/ip_var.h> 74#include <netinet/ip_icmp.h> 75#include <netinet/ip_fw.h> 76#include <netinet/ipfw/ip_fw_private.h> 77#include <netinet/ip_carp.h> 78#include <netinet/pim.h> 79#include <netinet/tcp_var.h> 80#include <netinet/udp.h> 81#include <netinet/udp_var.h> 82#include <netinet/sctp.h> 83 84#include <netinet/ip6.h> 85#include <netinet/icmp6.h> 86#ifdef INET6 87#include <netinet6/scope6_var.h> 88#include <netinet6/ip6_var.h> 89#endif 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) 108 109#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 110static int default_to_accept = 1; 111#else 112static int default_to_accept; 113#endif 114 115VNET_DEFINE(int, autoinc_step); 116 117/* 118 * Each rule belongs to one of 32 different sets (0..31). 119 * The variable set_disable contains one bit per set. 120 * If the bit is set, all rules in the corresponding set 121 * are disabled. Set RESVD_SET(31) is reserved for the default rule 122 * and rules that are not deleted by the flush command, 123 * and CANNOT be disabled. 124 * Rules in set RESVD_SET can only be deleted individually. 125 */ 126VNET_DEFINE(u_int32_t, set_disable); 127#define V_set_disable VNET(set_disable) 128 129VNET_DEFINE(int, fw_verbose); 130/* counter for ipfw_log(NULL...) */ 131VNET_DEFINE(u_int64_t, norule_counter); 132VNET_DEFINE(int, verbose_limit); 133 134/* layer3_chain contains the list of rules for layer 3 */ 135VNET_DEFINE(struct ip_fw_chain, layer3_chain); 136 137ipfw_nat_t *ipfw_nat_ptr = NULL; 138struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int); 139ipfw_nat_cfg_t *ipfw_nat_cfg_ptr; 140ipfw_nat_cfg_t *ipfw_nat_del_ptr; 141ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr; 142ipfw_nat_cfg_t *ipfw_nat_get_log_ptr; 143 144#ifdef SYSCTL_NODE 145SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 146SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 147 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0, 148 "Only do a single pass through ipfw when using dummynet(4)"); 149SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, 150 CTLFLAG_RW, &VNET_NAME(autoinc_step), 0, 151 "Rule number auto-increment step"); 152SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose, 153 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0, 154 "Log matches to ipfw rules"); 155SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, 156 CTLFLAG_RW, &VNET_NAME(verbose_limit), 0, 157 "Set upper limit of matches of ipfw rules logged"); 158SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD, 159 NULL, IPFW_DEFAULT_RULE, 160 "The default/max possible rule number."); 161SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, tables_max, CTLFLAG_RD, 162 NULL, IPFW_TABLES_MAX, 163 "The maximum number of tables."); 164SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN, 165 &default_to_accept, 0, 166 "Make the default rule accept all packets."); 167TUNABLE_INT("net.inet.ip.fw.default_to_accept", &default_to_accept); 168SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, static_count, 169 CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0, 170 "Number of static rules"); 171 172#ifdef INET6 173SYSCTL_DECL(_net_inet6_ip6); 174SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 175SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs, 176 CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_deny_unknown_exthdrs), 0, 177 "Deny packets with unknown IPv6 Extension Headers"); 178#endif /* INET6 */ 179 180#endif /* SYSCTL_NODE */ 181 182 183/* 184 * Some macros used in the various matching options. 185 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 186 * Other macros just cast void * into the appropriate type 187 */ 188#define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 189#define TCP(p) ((struct tcphdr *)(p)) 190#define SCTP(p) ((struct sctphdr *)(p)) 191#define UDP(p) ((struct udphdr *)(p)) 192#define ICMP(p) ((struct icmphdr *)(p)) 193#define ICMP6(p) ((struct icmp6_hdr *)(p)) 194 195static __inline int 196icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 197{ 198 int type = icmp->icmp_type; 199 200 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 201} 202 203#define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 204 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 205 206static int 207is_icmp_query(struct icmphdr *icmp) 208{ 209 int type = icmp->icmp_type; 210 211 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 212} 213#undef TT 214 215/* 216 * The following checks use two arrays of 8 or 16 bits to store the 217 * bits that we want set or clear, respectively. They are in the 218 * low and high half of cmd->arg1 or cmd->d[0]. 219 * 220 * We scan options and store the bits we find set. We succeed if 221 * 222 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 223 * 224 * The code is sometimes optimized not to store additional variables. 225 */ 226 227static int 228flags_match(ipfw_insn *cmd, u_int8_t bits) 229{ 230 u_char want_clear; 231 bits = ~bits; 232 233 if ( ((cmd->arg1 & 0xff) & bits) != 0) 234 return 0; /* some bits we want set were clear */ 235 want_clear = (cmd->arg1 >> 8) & 0xff; 236 if ( (want_clear & bits) != want_clear) 237 return 0; /* some bits we want clear were set */ 238 return 1; 239} 240 241static int 242ipopts_match(struct ip *ip, ipfw_insn *cmd) 243{ 244 int optlen, bits = 0; 245 u_char *cp = (u_char *)(ip + 1); 246 int x = (ip->ip_hl << 2) - sizeof (struct ip); 247 248 for (; x > 0; x -= optlen, cp += optlen) { 249 int opt = cp[IPOPT_OPTVAL]; 250 251 if (opt == IPOPT_EOL) 252 break; 253 if (opt == IPOPT_NOP) 254 optlen = 1; 255 else { 256 optlen = cp[IPOPT_OLEN]; 257 if (optlen <= 0 || optlen > x) 258 return 0; /* invalid or truncated */ 259 } 260 switch (opt) { 261 262 default: 263 break; 264 265 case IPOPT_LSRR: 266 bits |= IP_FW_IPOPT_LSRR; 267 break; 268 269 case IPOPT_SSRR: 270 bits |= IP_FW_IPOPT_SSRR; 271 break; 272 273 case IPOPT_RR: 274 bits |= IP_FW_IPOPT_RR; 275 break; 276 277 case IPOPT_TS: 278 bits |= IP_FW_IPOPT_TS; 279 break; 280 } 281 } 282 return (flags_match(cmd, bits)); 283} 284 285static int 286tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 287{ 288 int optlen, bits = 0; 289 u_char *cp = (u_char *)(tcp + 1); 290 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 291 292 for (; x > 0; x -= optlen, cp += optlen) { 293 int opt = cp[0]; 294 if (opt == TCPOPT_EOL) 295 break; 296 if (opt == TCPOPT_NOP) 297 optlen = 1; 298 else { 299 optlen = cp[1]; 300 if (optlen <= 0) 301 break; 302 } 303 304 switch (opt) { 305 306 default: 307 break; 308 309 case TCPOPT_MAXSEG: 310 bits |= IP_FW_TCPOPT_MSS; 311 break; 312 313 case TCPOPT_WINDOW: 314 bits |= IP_FW_TCPOPT_WINDOW; 315 break; 316 317 case TCPOPT_SACK_PERMITTED: 318 case TCPOPT_SACK: 319 bits |= IP_FW_TCPOPT_SACK; 320 break; 321 322 case TCPOPT_TIMESTAMP: 323 bits |= IP_FW_TCPOPT_TS; 324 break; 325 326 } 327 } 328 return (flags_match(cmd, bits)); 329} 330 331static int 332iface_match(struct ifnet *ifp, ipfw_insn_if *cmd) 333{ 334 if (ifp == NULL) /* no iface with this packet, match fails */ 335 return 0; 336 /* Check by name or by IP address */ 337 if (cmd->name[0] != '\0') { /* match by name */ 338 /* Check name */ 339 if (cmd->p.glob) { 340 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 341 return(1); 342 } else { 343 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 344 return(1); 345 } 346 } else { 347 struct ifaddr *ia; 348 349 if_addr_rlock(ifp); 350 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 351 if (ia->ifa_addr->sa_family != AF_INET) 352 continue; 353 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 354 (ia->ifa_addr))->sin_addr.s_addr) { 355 if_addr_runlock(ifp); 356 return(1); /* match */ 357 } 358 } 359 if_addr_runlock(ifp); 360 } 361 return(0); /* no match, fail ... */ 362} 363 364/* 365 * The verify_path function checks if a route to the src exists and 366 * if it is reachable via ifp (when provided). 367 * 368 * The 'verrevpath' option checks that the interface that an IP packet 369 * arrives on is the same interface that traffic destined for the 370 * packet's source address would be routed out of. 371 * The 'versrcreach' option just checks that the source address is 372 * reachable via any route (except default) in the routing table. 373 * These two are a measure to block forged packets. This is also 374 * commonly known as "anti-spoofing" or Unicast Reverse Path 375 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 376 * is purposely reminiscent of the Cisco IOS command, 377 * 378 * ip verify unicast reverse-path 379 * ip verify unicast source reachable-via any 380 * 381 * which implements the same functionality. But note that the syntax 382 * is misleading, and the check may be performed on all IP packets 383 * whether unicast, multicast, or broadcast. 384 */ 385static int 386verify_path(struct in_addr src, struct ifnet *ifp, u_int fib) 387{ 388 struct route ro; 389 struct sockaddr_in *dst; 390 391 bzero(&ro, sizeof(ro)); 392 393 dst = (struct sockaddr_in *)&(ro.ro_dst); 394 dst->sin_family = AF_INET; 395 dst->sin_len = sizeof(*dst); 396 dst->sin_addr = src; 397 in_rtalloc_ign(&ro, 0, fib); 398 399 if (ro.ro_rt == NULL) 400 return 0; 401 402 /* 403 * If ifp is provided, check for equality with rtentry. 404 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 405 * in order to pass packets injected back by if_simloop(): 406 * if useloopback == 1 routing entry (via lo0) for our own address 407 * may exist, so we need to handle routing assymetry. 408 */ 409 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 410 RTFREE(ro.ro_rt); 411 return 0; 412 } 413 414 /* if no ifp provided, check if rtentry is not default route */ 415 if (ifp == NULL && 416 satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) { 417 RTFREE(ro.ro_rt); 418 return 0; 419 } 420 421 /* or if this is a blackhole/reject route */ 422 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 423 RTFREE(ro.ro_rt); 424 return 0; 425 } 426 427 /* found valid route */ 428 RTFREE(ro.ro_rt); 429 return 1; 430} 431 432#ifdef INET6 433/* 434 * ipv6 specific rules here... 435 */ 436static __inline int 437icmp6type_match (int type, ipfw_insn_u32 *cmd) 438{ 439 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 440} 441 442static int 443flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 444{ 445 int i; 446 for (i=0; i <= cmd->o.arg1; ++i ) 447 if (curr_flow == cmd->d[i] ) 448 return 1; 449 return 0; 450} 451 452/* support for IP6_*_ME opcodes */ 453static int 454search_ip6_addr_net (struct in6_addr * ip6_addr) 455{ 456 struct ifnet *mdc; 457 struct ifaddr *mdc2; 458 struct in6_ifaddr *fdm; 459 struct in6_addr copia; 460 461 TAILQ_FOREACH(mdc, &V_ifnet, if_link) { 462 if_addr_rlock(mdc); 463 TAILQ_FOREACH(mdc2, &mdc->if_addrhead, ifa_link) { 464 if (mdc2->ifa_addr->sa_family == AF_INET6) { 465 fdm = (struct in6_ifaddr *)mdc2; 466 copia = fdm->ia_addr.sin6_addr; 467 /* need for leaving scope_id in the sock_addr */ 468 in6_clearscope(&copia); 469 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) { 470 if_addr_runlock(mdc); 471 return 1; 472 } 473 } 474 } 475 if_addr_runlock(mdc); 476 } 477 return 0; 478} 479 480static int 481verify_path6(struct in6_addr *src, struct ifnet *ifp) 482{ 483 struct route_in6 ro; 484 struct sockaddr_in6 *dst; 485 486 bzero(&ro, sizeof(ro)); 487 488 dst = (struct sockaddr_in6 * )&(ro.ro_dst); 489 dst->sin6_family = AF_INET6; 490 dst->sin6_len = sizeof(*dst); 491 dst->sin6_addr = *src; 492 /* XXX MRT 0 for ipv6 at this time */ 493 rtalloc_ign((struct route *)&ro, 0); 494 495 if (ro.ro_rt == NULL) 496 return 0; 497 498 /* 499 * if ifp is provided, check for equality with rtentry 500 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 501 * to support the case of sending packets to an address of our own. 502 * (where the former interface is the first argument of if_simloop() 503 * (=ifp), the latter is lo0) 504 */ 505 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 506 RTFREE(ro.ro_rt); 507 return 0; 508 } 509 510 /* if no ifp provided, check if rtentry is not default route */ 511 if (ifp == NULL && 512 IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) { 513 RTFREE(ro.ro_rt); 514 return 0; 515 } 516 517 /* or if this is a blackhole/reject route */ 518 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 519 RTFREE(ro.ro_rt); 520 return 0; 521 } 522 523 /* found valid route */ 524 RTFREE(ro.ro_rt); 525 return 1; 526 527} 528 529static int 530is_icmp6_query(int icmp6_type) 531{ 532 if ((icmp6_type <= ICMP6_MAXTYPE) && 533 (icmp6_type == ICMP6_ECHO_REQUEST || 534 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 535 icmp6_type == ICMP6_WRUREQUEST || 536 icmp6_type == ICMP6_FQDN_QUERY || 537 icmp6_type == ICMP6_NI_QUERY)) 538 return (1); 539 540 return (0); 541} 542 543static void 544send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 545{ 546 struct mbuf *m; 547 548 m = args->m; 549 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 550 struct tcphdr *tcp; 551 tcp = (struct tcphdr *)((char *)ip6 + hlen); 552 553 if ((tcp->th_flags & TH_RST) == 0) { 554 struct mbuf *m0; 555 m0 = ipfw_send_pkt(args->m, &(args->f_id), 556 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 557 tcp->th_flags | TH_RST); 558 if (m0 != NULL) 559 ip6_output(m0, NULL, NULL, 0, NULL, NULL, 560 NULL); 561 } 562 FREE_PKT(m); 563 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */ 564#if 0 565 /* 566 * Unlike above, the mbufs need to line up with the ip6 hdr, 567 * as the contents are read. We need to m_adj() the 568 * needed amount. 569 * The mbuf will however be thrown away so we can adjust it. 570 * Remember we did an m_pullup on it already so we 571 * can make some assumptions about contiguousness. 572 */ 573 if (args->L3offset) 574 m_adj(m, args->L3offset); 575#endif 576 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 577 } else 578 FREE_PKT(m); 579 580 args->m = NULL; 581} 582 583#endif /* INET6 */ 584 585 586/* 587 * sends a reject message, consuming the mbuf passed as an argument. 588 */ 589static void 590send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip) 591{ 592 593#if 0 594 /* XXX When ip is not guaranteed to be at mtod() we will 595 * need to account for this */ 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 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */ 604 /* We need the IP header in host order for icmp_error(). */ 605 SET_HOST_IPLEN(ip); 606 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 607 } else if (args->f_id.proto == IPPROTO_TCP) { 608 struct tcphdr *const tcp = 609 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 610 if ( (tcp->th_flags & TH_RST) == 0) { 611 struct mbuf *m; 612 m = ipfw_send_pkt(args->m, &(args->f_id), 613 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 614 tcp->th_flags | TH_RST); 615 if (m != NULL) 616 ip_output(m, NULL, NULL, 0, NULL, NULL); 617 } 618 FREE_PKT(args->m); 619 } else 620 FREE_PKT(args->m); 621 args->m = NULL; 622} 623 624/* 625 * Support for uid/gid/jail lookup. These tests are expensive 626 * (because we may need to look into the list of active sockets) 627 * so we cache the results. ugid_lookupp is 0 if we have not 628 * yet done a lookup, 1 if we succeeded, and -1 if we tried 629 * and failed. The function always returns the match value. 630 * We could actually spare the variable and use *uc, setting 631 * it to '(void *)check_uidgid if we have no info, NULL if 632 * we tried and failed, or any other value if successful. 633 */ 634static int 635check_uidgid(ipfw_insn_u32 *insn, int proto, struct ifnet *oif, 636 struct in_addr dst_ip, u_int16_t dst_port, struct in_addr src_ip, 637 u_int16_t src_port, struct ucred **uc, int *ugid_lookupp, 638 struct inpcb *inp) 639{ 640 struct inpcbinfo *pi; 641 int wildcard; 642 struct inpcb *pcb; 643 int match; 644 645 /* 646 * Check to see if the UDP or TCP stack supplied us with 647 * the PCB. If so, rather then holding a lock and looking 648 * up the PCB, we can use the one that was supplied. 649 */ 650 if (inp && *ugid_lookupp == 0) { 651 INP_LOCK_ASSERT(inp); 652 if (inp->inp_socket != NULL) { 653 *uc = crhold(inp->inp_cred); 654 *ugid_lookupp = 1; 655 } else 656 *ugid_lookupp = -1; 657 } 658 /* 659 * If we have already been here and the packet has no 660 * PCB entry associated with it, then we can safely 661 * assume that this is a no match. 662 */ 663 if (*ugid_lookupp == -1) 664 return (0); 665 if (proto == IPPROTO_TCP) { 666 wildcard = 0; 667 pi = &V_tcbinfo; 668 } else if (proto == IPPROTO_UDP) { 669 wildcard = INPLOOKUP_WILDCARD; 670 pi = &V_udbinfo; 671 } else 672 return 0; 673 match = 0; 674 if (*ugid_lookupp == 0) { 675 INP_INFO_RLOCK(pi); 676 pcb = (oif) ? 677 in_pcblookup_hash(pi, 678 dst_ip, htons(dst_port), 679 src_ip, htons(src_port), 680 wildcard, oif) : 681 in_pcblookup_hash(pi, 682 src_ip, htons(src_port), 683 dst_ip, htons(dst_port), 684 wildcard, NULL); 685 if (pcb != NULL) { 686 *uc = crhold(pcb->inp_cred); 687 *ugid_lookupp = 1; 688 } 689 INP_INFO_RUNLOCK(pi); 690 if (*ugid_lookupp == 0) { 691 /* 692 * We tried and failed, set the variable to -1 693 * so we will not try again on this packet. 694 */ 695 *ugid_lookupp = -1; 696 return (0); 697 } 698 } 699 if (insn->o.opcode == O_UID) 700 match = ((*uc)->cr_uid == (uid_t)insn->d[0]); 701 else if (insn->o.opcode == O_GID) 702 match = groupmember((gid_t)insn->d[0], *uc); 703 else if (insn->o.opcode == O_JAIL) 704 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]); 705 return match; 706} 707 708/* 709 * Helper function to set args with info on the rule after the matching 710 * one. slot is precise, whereas we guess rule_id as they are 711 * assigned sequentially. 712 */ 713static inline void 714set_match(struct ip_fw_args *args, int slot, 715 struct ip_fw_chain *chain) 716{ 717 args->rule.chain_id = chain->id; 718 args->rule.slot = slot + 1; /* we use 0 as a marker */ 719 args->rule.rule_id = 1 + chain->map[slot]->id; 720 args->rule.rulenum = chain->map[slot]->rulenum; 721} 722 723/* 724 * The main check routine for the firewall. 725 * 726 * All arguments are in args so we can modify them and return them 727 * back to the caller. 728 * 729 * Parameters: 730 * 731 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 732 * Starts with the IP header. 733 * args->eh (in) Mac header if present, NULL for layer3 packet. 734 * args->L3offset Number of bytes bypassed if we came from L2. 735 * e.g. often sizeof(eh) ** NOTYET ** 736 * args->oif Outgoing interface, NULL if packet is incoming. 737 * The incoming interface is in the mbuf. (in) 738 * args->divert_rule (in/out) 739 * Skip up to the first rule past this rule number; 740 * upon return, non-zero port number for divert or tee. 741 * 742 * args->rule Pointer to the last matching rule (in/out) 743 * args->next_hop Socket we are forwarding to (out). 744 * args->f_id Addresses grabbed from the packet (out) 745 * args->rule.info a cookie depending on rule action 746 * 747 * Return value: 748 * 749 * IP_FW_PASS the packet must be accepted 750 * IP_FW_DENY the packet must be dropped 751 * IP_FW_DIVERT divert packet, port in m_tag 752 * IP_FW_TEE tee packet, port in m_tag 753 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 754 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 755 * args->rule contains the matching rule, 756 * args->rule.info has additional information. 757 * 758 */ 759int 760ipfw_chk(struct ip_fw_args *args) 761{ 762 763 /* 764 * Local variables holding state while processing a packet: 765 * 766 * IMPORTANT NOTE: to speed up the processing of rules, there 767 * are some assumption on the values of the variables, which 768 * are documented here. Should you change them, please check 769 * the implementation of the various instructions to make sure 770 * that they still work. 771 * 772 * args->eh The MAC header. It is non-null for a layer2 773 * packet, it is NULL for a layer-3 packet. 774 * **notyet** 775 * args->L3offset Offset in the packet to the L3 (IP or equiv.) header. 776 * 777 * m | args->m Pointer to the mbuf, as received from the caller. 778 * It may change if ipfw_chk() does an m_pullup, or if it 779 * consumes the packet because it calls send_reject(). 780 * XXX This has to change, so that ipfw_chk() never modifies 781 * or consumes the buffer. 782 * ip is the beginning of the ip(4 or 6) header. 783 * Calculated by adding the L3offset to the start of data. 784 * (Until we start using L3offset, the packet is 785 * supposed to start with the ip header). 786 */ 787 struct mbuf *m = args->m; 788 struct ip *ip = mtod(m, struct ip *); 789 790 /* 791 * For rules which contain uid/gid or jail constraints, cache 792 * a copy of the users credentials after the pcb lookup has been 793 * executed. This will speed up the processing of rules with 794 * these types of constraints, as well as decrease contention 795 * on pcb related locks. 796 */ 797 struct ucred *ucred_cache = NULL; 798 int ucred_lookup = 0; 799 800 /* 801 * oif | args->oif If NULL, ipfw_chk has been called on the 802 * inbound path (ether_input, ip_input). 803 * If non-NULL, ipfw_chk has been called on the outbound path 804 * (ether_output, ip_output). 805 */ 806 struct ifnet *oif = args->oif; 807 808 int f_pos = 0; /* index of current rule in the array */ 809 int retval = 0; 810 811 /* 812 * hlen The length of the IP header. 813 */ 814 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 815 816 /* 817 * offset The offset of a fragment. offset != 0 means that 818 * we have a fragment at this offset of an IPv4 packet. 819 * offset == 0 means that (if this is an IPv4 packet) 820 * this is the first or only fragment. 821 * For IPv6 offset == 0 means there is no Fragment Header. 822 * If offset != 0 for IPv6 always use correct mask to 823 * get the correct offset because we add IP6F_MORE_FRAG 824 * to be able to dectect the first fragment which would 825 * otherwise have offset = 0. 826 */ 827 u_short offset = 0; 828 829 /* 830 * Local copies of addresses. They are only valid if we have 831 * an IP packet. 832 * 833 * proto The protocol. Set to 0 for non-ip packets, 834 * or to the protocol read from the packet otherwise. 835 * proto != 0 means that we have an IPv4 packet. 836 * 837 * src_port, dst_port port numbers, in HOST format. Only 838 * valid for TCP and UDP packets. 839 * 840 * src_ip, dst_ip ip addresses, in NETWORK format. 841 * Only valid for IPv4 packets. 842 */ 843 uint8_t proto; 844 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 845 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 846 uint16_t iplen=0; 847 int pktlen; 848 uint16_t etype = 0; /* Host order stored ether type */ 849 850 /* 851 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 852 * MATCH_NONE when checked and not matched (q = NULL), 853 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) 854 */ 855 int dyn_dir = MATCH_UNKNOWN; 856 ipfw_dyn_rule *q = NULL; 857 struct ip_fw_chain *chain = &V_layer3_chain; 858 859 /* 860 * We store in ulp a pointer to the upper layer protocol header. 861 * In the ipv4 case this is easy to determine from the header, 862 * but for ipv6 we might have some additional headers in the middle. 863 * ulp is NULL if not found. 864 */ 865 void *ulp = NULL; /* upper layer protocol pointer. */ 866 /* XXX ipv6 variables */ 867 int is_ipv6 = 0; 868 u_int16_t ext_hd = 0; /* bits vector for extension header filtering */ 869 /* end of ipv6 variables */ 870 int is_ipv4 = 0; 871 872 int done = 0; /* flag to exit the outer loop */ 873 874 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready)) 875 return (IP_FW_PASS); /* accept */ 876 877 dst_ip.s_addr = 0; /* make sure it is initialized */ 878 src_ip.s_addr = 0; /* make sure it is initialized */ 879 pktlen = m->m_pkthdr.len; 880 args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */ 881 proto = args->f_id.proto = 0; /* mark f_id invalid */ 882 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ 883 884/* 885 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 886 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 887 * pointer might become stale after other pullups (but we never use it 888 * this way). 889 */ 890#define PULLUP_TO(_len, p, T) \ 891do { \ 892 int x = (_len) + sizeof(T); \ 893 if ((m)->m_len < x) { \ 894 args->m = m = m_pullup(m, x); \ 895 if (m == NULL) \ 896 goto pullup_failed; \ 897 } \ 898 p = (mtod(m, char *) + (_len)); \ 899} while (0) 900 901 /* 902 * if we have an ether header, 903 */ 904 if (args->eh) 905 etype = ntohs(args->eh->ether_type); 906 907 /* Identify IP packets and fill up variables. */ 908 if (pktlen >= sizeof(struct ip6_hdr) && 909 (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) { 910 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 911 is_ipv6 = 1; 912 args->f_id.addr_type = 6; 913 hlen = sizeof(struct ip6_hdr); 914 proto = ip6->ip6_nxt; 915 916 /* Search extension headers to find upper layer protocols */ 917 while (ulp == NULL) { 918 switch (proto) { 919 case IPPROTO_ICMPV6: 920 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 921 args->f_id.flags = ICMP6(ulp)->icmp6_type; 922 break; 923 924 case IPPROTO_TCP: 925 PULLUP_TO(hlen, ulp, struct tcphdr); 926 dst_port = TCP(ulp)->th_dport; 927 src_port = TCP(ulp)->th_sport; 928 args->f_id.flags = TCP(ulp)->th_flags; 929 break; 930 931 case IPPROTO_SCTP: 932 PULLUP_TO(hlen, ulp, struct sctphdr); 933 src_port = SCTP(ulp)->src_port; 934 dst_port = SCTP(ulp)->dest_port; 935 break; 936 937 case IPPROTO_UDP: 938 PULLUP_TO(hlen, ulp, struct udphdr); 939 dst_port = UDP(ulp)->uh_dport; 940 src_port = UDP(ulp)->uh_sport; 941 break; 942 943 case IPPROTO_HOPOPTS: /* RFC 2460 */ 944 PULLUP_TO(hlen, ulp, struct ip6_hbh); 945 ext_hd |= EXT_HOPOPTS; 946 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 947 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 948 ulp = NULL; 949 break; 950 951 case IPPROTO_ROUTING: /* RFC 2460 */ 952 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 953 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 954 case 0: 955 ext_hd |= EXT_RTHDR0; 956 break; 957 case 2: 958 ext_hd |= EXT_RTHDR2; 959 break; 960 default: 961 printf("IPFW2: IPV6 - Unknown Routing " 962 "Header type(%d)\n", 963 ((struct ip6_rthdr *)ulp)->ip6r_type); 964 if (V_fw_deny_unknown_exthdrs) 965 return (IP_FW_DENY); 966 break; 967 } 968 ext_hd |= EXT_ROUTING; 969 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 970 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 971 ulp = NULL; 972 break; 973 974 case IPPROTO_FRAGMENT: /* RFC 2460 */ 975 PULLUP_TO(hlen, ulp, struct ip6_frag); 976 ext_hd |= EXT_FRAGMENT; 977 hlen += sizeof (struct ip6_frag); 978 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 979 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 980 IP6F_OFF_MASK; 981 /* Add IP6F_MORE_FRAG for offset of first 982 * fragment to be != 0. */ 983 offset |= ((struct ip6_frag *)ulp)->ip6f_offlg & 984 IP6F_MORE_FRAG; 985 if (offset == 0) { 986 printf("IPFW2: IPV6 - Invalid Fragment " 987 "Header\n"); 988 if (V_fw_deny_unknown_exthdrs) 989 return (IP_FW_DENY); 990 break; 991 } 992 args->f_id.frag_id6 = 993 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 994 ulp = NULL; 995 break; 996 997 case IPPROTO_DSTOPTS: /* RFC 2460 */ 998 PULLUP_TO(hlen, ulp, struct ip6_hbh); 999 ext_hd |= EXT_DSTOPTS; 1000 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1001 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1002 ulp = NULL; 1003 break; 1004 1005 case IPPROTO_AH: /* RFC 2402 */ 1006 PULLUP_TO(hlen, ulp, struct ip6_ext); 1007 ext_hd |= EXT_AH; 1008 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 1009 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 1010 ulp = NULL; 1011 break; 1012 1013 case IPPROTO_ESP: /* RFC 2406 */ 1014 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 1015 /* Anything past Seq# is variable length and 1016 * data past this ext. header is encrypted. */ 1017 ext_hd |= EXT_ESP; 1018 break; 1019 1020 case IPPROTO_NONE: /* RFC 2460 */ 1021 /* 1022 * Packet ends here, and IPv6 header has 1023 * already been pulled up. If ip6e_len!=0 1024 * then octets must be ignored. 1025 */ 1026 ulp = ip; /* non-NULL to get out of loop. */ 1027 break; 1028 1029 case IPPROTO_OSPFIGP: 1030 /* XXX OSPF header check? */ 1031 PULLUP_TO(hlen, ulp, struct ip6_ext); 1032 break; 1033 1034 case IPPROTO_PIM: 1035 /* XXX PIM header check? */ 1036 PULLUP_TO(hlen, ulp, struct pim); 1037 break; 1038 1039 case IPPROTO_CARP: 1040 PULLUP_TO(hlen, ulp, struct carp_header); 1041 if (((struct carp_header *)ulp)->carp_version != 1042 CARP_VERSION) 1043 return (IP_FW_DENY); 1044 if (((struct carp_header *)ulp)->carp_type != 1045 CARP_ADVERTISEMENT) 1046 return (IP_FW_DENY); 1047 break; 1048 1049 case IPPROTO_IPV6: /* RFC 2893 */ 1050 PULLUP_TO(hlen, ulp, struct ip6_hdr); 1051 break; 1052 1053 case IPPROTO_IPV4: /* RFC 2893 */ 1054 PULLUP_TO(hlen, ulp, struct ip); 1055 break; 1056 1057 default: 1058 printf("IPFW2: IPV6 - Unknown Extension " 1059 "Header(%d), ext_hd=%x\n", proto, ext_hd); 1060 if (V_fw_deny_unknown_exthdrs) 1061 return (IP_FW_DENY); 1062 PULLUP_TO(hlen, ulp, struct ip6_ext); 1063 break; 1064 } /*switch */ 1065 } 1066 ip = mtod(m, struct ip *); 1067 ip6 = (struct ip6_hdr *)ip; 1068 args->f_id.src_ip6 = ip6->ip6_src; 1069 args->f_id.dst_ip6 = ip6->ip6_dst; 1070 args->f_id.src_ip = 0; 1071 args->f_id.dst_ip = 0; 1072 args->f_id.flow_id6 = ntohl(ip6->ip6_flow); 1073 } else if (pktlen >= sizeof(struct ip) && 1074 (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) { 1075 is_ipv4 = 1; 1076 hlen = ip->ip_hl << 2; 1077 args->f_id.addr_type = 4; 1078 1079 /* 1080 * Collect parameters into local variables for faster matching. 1081 */ 1082 proto = ip->ip_p; 1083 src_ip = ip->ip_src; 1084 dst_ip = ip->ip_dst; 1085 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1086 iplen = ntohs(ip->ip_len); 1087 pktlen = iplen < pktlen ? iplen : pktlen; 1088 1089 if (offset == 0) { 1090 switch (proto) { 1091 case IPPROTO_TCP: 1092 PULLUP_TO(hlen, ulp, struct tcphdr); 1093 dst_port = TCP(ulp)->th_dport; 1094 src_port = TCP(ulp)->th_sport; 1095 args->f_id.flags = TCP(ulp)->th_flags; 1096 break; 1097 1098 case IPPROTO_UDP: 1099 PULLUP_TO(hlen, ulp, struct udphdr); 1100 dst_port = UDP(ulp)->uh_dport; 1101 src_port = UDP(ulp)->uh_sport; 1102 break; 1103 1104 case IPPROTO_ICMP: 1105 PULLUP_TO(hlen, ulp, struct icmphdr); 1106 args->f_id.flags = ICMP(ulp)->icmp_type; 1107 break; 1108 1109 default: 1110 break; 1111 } 1112 } 1113 1114 ip = mtod(m, struct ip *); 1115 args->f_id.src_ip = ntohl(src_ip.s_addr); 1116 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1117 } 1118#undef PULLUP_TO 1119 if (proto) { /* we may have port numbers, store them */ 1120 args->f_id.proto = proto; 1121 args->f_id.src_port = src_port = ntohs(src_port); 1122 args->f_id.dst_port = dst_port = ntohs(dst_port); 1123 } 1124 1125 IPFW_RLOCK(chain); 1126 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ 1127 IPFW_RUNLOCK(chain); 1128 return (IP_FW_PASS); /* accept */ 1129 } 1130 if (args->rule.slot) { 1131 /* 1132 * Packet has already been tagged as a result of a previous 1133 * match on rule args->rule aka args->rule_id (PIPE, QUEUE, 1134 * REASS, NETGRAPH, DIVERT/TEE...) 1135 * Validate the slot and continue from the next one 1136 * if still present, otherwise do a lookup. 1137 */ 1138 f_pos = (args->rule.chain_id == chain->id) ? 1139 args->rule.slot : 1140 ipfw_find_rule(chain, args->rule.rulenum, 1141 args->rule.rule_id); 1142 } else { 1143 f_pos = 0; 1144 } 1145 1146 /* 1147 * Now scan the rules, and parse microinstructions for each rule. 1148 * We have two nested loops and an inner switch. Sometimes we 1149 * need to break out of one or both loops, or re-enter one of 1150 * the loops with updated variables. Loop variables are: 1151 * 1152 * f_pos (outer loop) points to the current rule. 1153 * On output it points to the matching rule. 1154 * done (outer loop) is used as a flag to break the loop. 1155 * l (inner loop) residual length of current rule. 1156 * cmd points to the current microinstruction. 1157 * 1158 * We break the inner loop by setting l=0 and possibly 1159 * cmdlen=0 if we don't want to advance cmd. 1160 * We break the outer loop by setting done=1 1161 * We can restart the inner loop by setting l>0 and f_pos, f, cmd 1162 * as needed. 1163 */ 1164 for (; f_pos < chain->n_rules; f_pos++) { 1165 ipfw_insn *cmd; 1166 uint32_t tablearg = 0; 1167 int l, cmdlen, skip_or; /* skip rest of OR block */ 1168 struct ip_fw *f; 1169 1170 f = chain->map[f_pos]; 1171 if (V_set_disable & (1 << f->set) ) 1172 continue; 1173 1174 skip_or = 0; 1175 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 1176 l -= cmdlen, cmd += cmdlen) { 1177 int match; 1178 1179 /* 1180 * check_body is a jump target used when we find a 1181 * CHECK_STATE, and need to jump to the body of 1182 * the target rule. 1183 */ 1184 1185/* check_body: */ 1186 cmdlen = F_LEN(cmd); 1187 /* 1188 * An OR block (insn_1 || .. || insn_n) has the 1189 * F_OR bit set in all but the last instruction. 1190 * The first match will set "skip_or", and cause 1191 * the following instructions to be skipped until 1192 * past the one with the F_OR bit clear. 1193 */ 1194 if (skip_or) { /* skip this instruction */ 1195 if ((cmd->len & F_OR) == 0) 1196 skip_or = 0; /* next one is good */ 1197 continue; 1198 } 1199 match = 0; /* set to 1 if we succeed */ 1200 1201 switch (cmd->opcode) { 1202 /* 1203 * The first set of opcodes compares the packet's 1204 * fields with some pattern, setting 'match' if a 1205 * match is found. At the end of the loop there is 1206 * logic to deal with F_NOT and F_OR flags associated 1207 * with the opcode. 1208 */ 1209 case O_NOP: 1210 match = 1; 1211 break; 1212 1213 case O_FORWARD_MAC: 1214 printf("ipfw: opcode %d unimplemented\n", 1215 cmd->opcode); 1216 break; 1217 1218 case O_GID: 1219 case O_UID: 1220 case O_JAIL: 1221 /* 1222 * We only check offset == 0 && proto != 0, 1223 * as this ensures that we have a 1224 * packet with the ports info. 1225 */ 1226 if (offset!=0) 1227 break; 1228 if (is_ipv6) /* XXX to be fixed later */ 1229 break; 1230 if (proto == IPPROTO_TCP || 1231 proto == IPPROTO_UDP) 1232 match = check_uidgid( 1233 (ipfw_insn_u32 *)cmd, 1234 proto, oif, 1235 dst_ip, dst_port, 1236 src_ip, src_port, &ucred_cache, 1237 &ucred_lookup, args->inp); 1238 break; 1239 1240 case O_RECV: 1241 match = iface_match(m->m_pkthdr.rcvif, 1242 (ipfw_insn_if *)cmd); 1243 break; 1244 1245 case O_XMIT: 1246 match = iface_match(oif, (ipfw_insn_if *)cmd); 1247 break; 1248 1249 case O_VIA: 1250 match = iface_match(oif ? oif : 1251 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd); 1252 break; 1253 1254 case O_MACADDR2: 1255 if (args->eh != NULL) { /* have MAC header */ 1256 u_int32_t *want = (u_int32_t *) 1257 ((ipfw_insn_mac *)cmd)->addr; 1258 u_int32_t *mask = (u_int32_t *) 1259 ((ipfw_insn_mac *)cmd)->mask; 1260 u_int32_t *hdr = (u_int32_t *)args->eh; 1261 1262 match = 1263 ( want[0] == (hdr[0] & mask[0]) && 1264 want[1] == (hdr[1] & mask[1]) && 1265 want[2] == (hdr[2] & mask[2]) ); 1266 } 1267 break; 1268 1269 case O_MAC_TYPE: 1270 if (args->eh != NULL) { 1271 u_int16_t *p = 1272 ((ipfw_insn_u16 *)cmd)->ports; 1273 int i; 1274 1275 for (i = cmdlen - 1; !match && i>0; 1276 i--, p += 2) 1277 match = (etype >= p[0] && 1278 etype <= p[1]); 1279 } 1280 break; 1281 1282 case O_FRAG: 1283 match = (offset != 0); 1284 break; 1285 1286 case O_IN: /* "out" is "not in" */ 1287 match = (oif == NULL); 1288 break; 1289 1290 case O_LAYER2: 1291 match = (args->eh != NULL); 1292 break; 1293 1294 case O_DIVERTED: 1295 { 1296 /* For diverted packets, args->rule.info 1297 * contains the divert port (in host format) 1298 * reason and direction. 1299 */ 1300 uint32_t i = args->rule.info; 1301 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT && 1302 cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2); 1303 } 1304 break; 1305 1306 case O_PROTO: 1307 /* 1308 * We do not allow an arg of 0 so the 1309 * check of "proto" only suffices. 1310 */ 1311 match = (proto == cmd->arg1); 1312 break; 1313 1314 case O_IP_SRC: 1315 match = is_ipv4 && 1316 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1317 src_ip.s_addr); 1318 break; 1319 1320 case O_IP_SRC_LOOKUP: 1321 case O_IP_DST_LOOKUP: 1322 if (is_ipv4) { 1323 uint32_t key = 1324 (cmd->opcode == O_IP_DST_LOOKUP) ? 1325 dst_ip.s_addr : src_ip.s_addr; 1326 uint32_t v = 0; 1327 1328 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { 1329 /* generic lookup. The key must be 1330 * in 32bit big-endian format. 1331 */ 1332 v = ((ipfw_insn_u32 *)cmd)->d[1]; 1333 if (v == 0) 1334 key = dst_ip.s_addr; 1335 else if (v == 1) 1336 key = src_ip.s_addr; 1337 else if (offset != 0) 1338 break; 1339 else if (proto != IPPROTO_TCP && 1340 proto != IPPROTO_UDP) 1341 break; 1342 else if (v == 2) 1343 key = htonl(dst_port); 1344 else if (v == 3) 1345 key = htonl(src_port); 1346 else if (v == 4 || v == 5) { 1347 check_uidgid( 1348 (ipfw_insn_u32 *)cmd, 1349 proto, oif, 1350 dst_ip, dst_port, 1351 src_ip, src_port, &ucred_cache, 1352 &ucred_lookup, args->inp); 1353 if (v == 4 /* O_UID */) 1354 key = ucred_cache->cr_uid; 1355 else if (v == 5 /* O_JAIL */) 1356 key = ucred_cache->cr_prison->pr_id; 1357 key = htonl(key); 1358 } else 1359 break; 1360 } 1361 match = ipfw_lookup_table(chain, 1362 cmd->arg1, key, &v); 1363 if (!match) 1364 break; 1365 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1366 match = 1367 ((ipfw_insn_u32 *)cmd)->d[0] == v; 1368 else 1369 tablearg = v; 1370 } 1371 break; 1372 1373 case O_IP_SRC_MASK: 1374 case O_IP_DST_MASK: 1375 if (is_ipv4) { 1376 uint32_t a = 1377 (cmd->opcode == O_IP_DST_MASK) ? 1378 dst_ip.s_addr : src_ip.s_addr; 1379 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 1380 int i = cmdlen-1; 1381 1382 for (; !match && i>0; i-= 2, p+= 2) 1383 match = (p[0] == (a & p[1])); 1384 } 1385 break; 1386 1387 case O_IP_SRC_ME: 1388 if (is_ipv4) { 1389 struct ifnet *tif; 1390 1391 INADDR_TO_IFP(src_ip, tif); 1392 match = (tif != NULL); 1393 } 1394 break; 1395 1396 case O_IP_DST_SET: 1397 case O_IP_SRC_SET: 1398 if (is_ipv4) { 1399 u_int32_t *d = (u_int32_t *)(cmd+1); 1400 u_int32_t addr = 1401 cmd->opcode == O_IP_DST_SET ? 1402 args->f_id.dst_ip : 1403 args->f_id.src_ip; 1404 1405 if (addr < d[0]) 1406 break; 1407 addr -= d[0]; /* subtract base */ 1408 match = (addr < cmd->arg1) && 1409 ( d[ 1 + (addr>>5)] & 1410 (1<<(addr & 0x1f)) ); 1411 } 1412 break; 1413 1414 case O_IP_DST: 1415 match = is_ipv4 && 1416 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1417 dst_ip.s_addr); 1418 break; 1419 1420 case O_IP_DST_ME: 1421 if (is_ipv4) { 1422 struct ifnet *tif; 1423 1424 INADDR_TO_IFP(dst_ip, tif); 1425 match = (tif != NULL); 1426 } 1427 break; 1428 1429 case O_IP_SRCPORT: 1430 case O_IP_DSTPORT: 1431 /* 1432 * offset == 0 && proto != 0 is enough 1433 * to guarantee that we have a 1434 * packet with port info. 1435 */ 1436 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP) 1437 && offset == 0) { 1438 u_int16_t x = 1439 (cmd->opcode == O_IP_SRCPORT) ? 1440 src_port : dst_port ; 1441 u_int16_t *p = 1442 ((ipfw_insn_u16 *)cmd)->ports; 1443 int i; 1444 1445 for (i = cmdlen - 1; !match && i>0; 1446 i--, p += 2) 1447 match = (x>=p[0] && x<=p[1]); 1448 } 1449 break; 1450 1451 case O_ICMPTYPE: 1452 match = (offset == 0 && proto==IPPROTO_ICMP && 1453 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 1454 break; 1455 1456#ifdef INET6 1457 case O_ICMP6TYPE: 1458 match = is_ipv6 && offset == 0 && 1459 proto==IPPROTO_ICMPV6 && 1460 icmp6type_match( 1461 ICMP6(ulp)->icmp6_type, 1462 (ipfw_insn_u32 *)cmd); 1463 break; 1464#endif /* INET6 */ 1465 1466 case O_IPOPT: 1467 match = (is_ipv4 && 1468 ipopts_match(ip, cmd) ); 1469 break; 1470 1471 case O_IPVER: 1472 match = (is_ipv4 && 1473 cmd->arg1 == ip->ip_v); 1474 break; 1475 1476 case O_IPID: 1477 case O_IPLEN: 1478 case O_IPTTL: 1479 if (is_ipv4) { /* only for IP packets */ 1480 uint16_t x; 1481 uint16_t *p; 1482 int i; 1483 1484 if (cmd->opcode == O_IPLEN) 1485 x = iplen; 1486 else if (cmd->opcode == O_IPTTL) 1487 x = ip->ip_ttl; 1488 else /* must be IPID */ 1489 x = ntohs(ip->ip_id); 1490 if (cmdlen == 1) { 1491 match = (cmd->arg1 == x); 1492 break; 1493 } 1494 /* otherwise we have ranges */ 1495 p = ((ipfw_insn_u16 *)cmd)->ports; 1496 i = cmdlen - 1; 1497 for (; !match && i>0; i--, p += 2) 1498 match = (x >= p[0] && x <= p[1]); 1499 } 1500 break; 1501 1502 case O_IPPRECEDENCE: 1503 match = (is_ipv4 && 1504 (cmd->arg1 == (ip->ip_tos & 0xe0)) ); 1505 break; 1506 1507 case O_IPTOS: 1508 match = (is_ipv4 && 1509 flags_match(cmd, ip->ip_tos)); 1510 break; 1511 1512 case O_TCPDATALEN: 1513 if (proto == IPPROTO_TCP && offset == 0) { 1514 struct tcphdr *tcp; 1515 uint16_t x; 1516 uint16_t *p; 1517 int i; 1518 1519 tcp = TCP(ulp); 1520 x = iplen - 1521 ((ip->ip_hl + tcp->th_off) << 2); 1522 if (cmdlen == 1) { 1523 match = (cmd->arg1 == x); 1524 break; 1525 } 1526 /* otherwise we have ranges */ 1527 p = ((ipfw_insn_u16 *)cmd)->ports; 1528 i = cmdlen - 1; 1529 for (; !match && i>0; i--, p += 2) 1530 match = (x >= p[0] && x <= p[1]); 1531 } 1532 break; 1533 1534 case O_TCPFLAGS: 1535 match = (proto == IPPROTO_TCP && offset == 0 && 1536 flags_match(cmd, TCP(ulp)->th_flags)); 1537 break; 1538 1539 case O_TCPOPTS: 1540 match = (proto == IPPROTO_TCP && offset == 0 && 1541 tcpopts_match(TCP(ulp), cmd)); 1542 break; 1543 1544 case O_TCPSEQ: 1545 match = (proto == IPPROTO_TCP && offset == 0 && 1546 ((ipfw_insn_u32 *)cmd)->d[0] == 1547 TCP(ulp)->th_seq); 1548 break; 1549 1550 case O_TCPACK: 1551 match = (proto == IPPROTO_TCP && offset == 0 && 1552 ((ipfw_insn_u32 *)cmd)->d[0] == 1553 TCP(ulp)->th_ack); 1554 break; 1555 1556 case O_TCPWIN: 1557 match = (proto == IPPROTO_TCP && offset == 0 && 1558 cmd->arg1 == TCP(ulp)->th_win); 1559 break; 1560 1561 case O_ESTAB: 1562 /* reject packets which have SYN only */ 1563 /* XXX should i also check for TH_ACK ? */ 1564 match = (proto == IPPROTO_TCP && offset == 0 && 1565 (TCP(ulp)->th_flags & 1566 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 1567 break; 1568 1569 case O_ALTQ: { 1570 struct pf_mtag *at; 1571 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 1572 1573 match = 1; 1574 at = pf_find_mtag(m); 1575 if (at != NULL && at->qid != 0) 1576 break; 1577 at = pf_get_mtag(m); 1578 if (at == NULL) { 1579 /* 1580 * Let the packet fall back to the 1581 * default ALTQ. 1582 */ 1583 break; 1584 } 1585 at->qid = altq->qid; 1586 if (is_ipv4) 1587 at->af = AF_INET; 1588 else 1589 at->af = AF_LINK; 1590 at->hdr = ip; 1591 break; 1592 } 1593 1594 case O_LOG: 1595 ipfw_log(f, hlen, args, m, 1596 oif, offset, tablearg, ip); 1597 match = 1; 1598 break; 1599 1600 case O_PROB: 1601 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 1602 break; 1603 1604 case O_VERREVPATH: 1605 /* Outgoing packets automatically pass/match */ 1606 match = ((oif != NULL) || 1607 (m->m_pkthdr.rcvif == NULL) || 1608 ( 1609#ifdef INET6 1610 is_ipv6 ? 1611 verify_path6(&(args->f_id.src_ip6), 1612 m->m_pkthdr.rcvif) : 1613#endif 1614 verify_path(src_ip, m->m_pkthdr.rcvif, 1615 args->f_id.fib))); 1616 break; 1617 1618 case O_VERSRCREACH: 1619 /* Outgoing packets automatically pass/match */ 1620 match = (hlen > 0 && ((oif != NULL) || 1621#ifdef INET6 1622 is_ipv6 ? 1623 verify_path6(&(args->f_id.src_ip6), 1624 NULL) : 1625#endif 1626 verify_path(src_ip, NULL, args->f_id.fib))); 1627 break; 1628 1629 case O_ANTISPOOF: 1630 /* Outgoing packets automatically pass/match */ 1631 if (oif == NULL && hlen > 0 && 1632 ( (is_ipv4 && in_localaddr(src_ip)) 1633#ifdef INET6 1634 || (is_ipv6 && 1635 in6_localaddr(&(args->f_id.src_ip6))) 1636#endif 1637 )) 1638 match = 1639#ifdef INET6 1640 is_ipv6 ? verify_path6( 1641 &(args->f_id.src_ip6), 1642 m->m_pkthdr.rcvif) : 1643#endif 1644 verify_path(src_ip, 1645 m->m_pkthdr.rcvif, 1646 args->f_id.fib); 1647 else 1648 match = 1; 1649 break; 1650 1651 case O_IPSEC: 1652#ifdef IPSEC 1653 match = (m_tag_find(m, 1654 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 1655#endif 1656 /* otherwise no match */ 1657 break; 1658 1659#ifdef INET6 1660 case O_IP6_SRC: 1661 match = is_ipv6 && 1662 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 1663 &((ipfw_insn_ip6 *)cmd)->addr6); 1664 break; 1665 1666 case O_IP6_DST: 1667 match = is_ipv6 && 1668 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 1669 &((ipfw_insn_ip6 *)cmd)->addr6); 1670 break; 1671 case O_IP6_SRC_MASK: 1672 case O_IP6_DST_MASK: 1673 if (is_ipv6) { 1674 int i = cmdlen - 1; 1675 struct in6_addr p; 1676 struct in6_addr *d = 1677 &((ipfw_insn_ip6 *)cmd)->addr6; 1678 1679 for (; !match && i > 0; d += 2, 1680 i -= F_INSN_SIZE(struct in6_addr) 1681 * 2) { 1682 p = (cmd->opcode == 1683 O_IP6_SRC_MASK) ? 1684 args->f_id.src_ip6: 1685 args->f_id.dst_ip6; 1686 APPLY_MASK(&p, &d[1]); 1687 match = 1688 IN6_ARE_ADDR_EQUAL(&d[0], 1689 &p); 1690 } 1691 } 1692 break; 1693 1694 case O_IP6_SRC_ME: 1695 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6); 1696 break; 1697 1698 case O_IP6_DST_ME: 1699 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6); 1700 break; 1701 1702 case O_FLOW6ID: 1703 match = is_ipv6 && 1704 flow6id_match(args->f_id.flow_id6, 1705 (ipfw_insn_u32 *) cmd); 1706 break; 1707 1708 case O_EXT_HDR: 1709 match = is_ipv6 && 1710 (ext_hd & ((ipfw_insn *) cmd)->arg1); 1711 break; 1712 1713 case O_IP6: 1714 match = is_ipv6; 1715 break; 1716#endif 1717 1718 case O_IP4: 1719 match = is_ipv4; 1720 break; 1721 1722 case O_TAG: { 1723 struct m_tag *mtag; 1724 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ? 1725 tablearg : cmd->arg1; 1726 1727 /* Packet is already tagged with this tag? */ 1728 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 1729 1730 /* We have `untag' action when F_NOT flag is 1731 * present. And we must remove this mtag from 1732 * mbuf and reset `match' to zero (`match' will 1733 * be inversed later). 1734 * Otherwise we should allocate new mtag and 1735 * push it into mbuf. 1736 */ 1737 if (cmd->len & F_NOT) { /* `untag' action */ 1738 if (mtag != NULL) 1739 m_tag_delete(m, mtag); 1740 match = 0; 1741 } else if (mtag == NULL) { 1742 if ((mtag = m_tag_alloc(MTAG_IPFW, 1743 tag, 0, M_NOWAIT)) != NULL) 1744 m_tag_prepend(m, mtag); 1745 match = 1; 1746 } 1747 break; 1748 } 1749 1750 case O_FIB: /* try match the specified fib */ 1751 if (args->f_id.fib == cmd->arg1) 1752 match = 1; 1753 break; 1754 1755 case O_TAGGED: { 1756 struct m_tag *mtag; 1757 uint32_t tag = (cmd->arg1 == IP_FW_TABLEARG) ? 1758 tablearg : cmd->arg1; 1759 1760 if (cmdlen == 1) { 1761 match = m_tag_locate(m, MTAG_IPFW, 1762 tag, NULL) != NULL; 1763 break; 1764 } 1765 1766 /* we have ranges */ 1767 for (mtag = m_tag_first(m); 1768 mtag != NULL && !match; 1769 mtag = m_tag_next(m, mtag)) { 1770 uint16_t *p; 1771 int i; 1772 1773 if (mtag->m_tag_cookie != MTAG_IPFW) 1774 continue; 1775 1776 p = ((ipfw_insn_u16 *)cmd)->ports; 1777 i = cmdlen - 1; 1778 for(; !match && i > 0; i--, p += 2) 1779 match = 1780 mtag->m_tag_id >= p[0] && 1781 mtag->m_tag_id <= p[1]; 1782 } 1783 break; 1784 } 1785 1786 /* 1787 * The second set of opcodes represents 'actions', 1788 * i.e. the terminal part of a rule once the packet 1789 * matches all previous patterns. 1790 * Typically there is only one action for each rule, 1791 * and the opcode is stored at the end of the rule 1792 * (but there are exceptions -- see below). 1793 * 1794 * In general, here we set retval and terminate the 1795 * outer loop (would be a 'break 3' in some language, 1796 * but we need to set l=0, done=1) 1797 * 1798 * Exceptions: 1799 * O_COUNT and O_SKIPTO actions: 1800 * instead of terminating, we jump to the next rule 1801 * (setting l=0), or to the SKIPTO target (setting 1802 * f/f_len, cmd and l as needed), respectively. 1803 * 1804 * O_TAG, O_LOG and O_ALTQ action parameters: 1805 * perform some action and set match = 1; 1806 * 1807 * O_LIMIT and O_KEEP_STATE: these opcodes are 1808 * not real 'actions', and are stored right 1809 * before the 'action' part of the rule. 1810 * These opcodes try to install an entry in the 1811 * state tables; if successful, we continue with 1812 * the next opcode (match=1; break;), otherwise 1813 * the packet must be dropped (set retval, 1814 * break loops with l=0, done=1) 1815 * 1816 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 1817 * cause a lookup of the state table, and a jump 1818 * to the 'action' part of the parent rule 1819 * if an entry is found, or 1820 * (CHECK_STATE only) a jump to the next rule if 1821 * the entry is not found. 1822 * The result of the lookup is cached so that 1823 * further instances of these opcodes become NOPs. 1824 * The jump to the next rule is done by setting 1825 * l=0, cmdlen=0. 1826 */ 1827 case O_LIMIT: 1828 case O_KEEP_STATE: 1829 if (ipfw_install_state(f, 1830 (ipfw_insn_limit *)cmd, args, tablearg)) { 1831 /* error or limit violation */ 1832 retval = IP_FW_DENY; 1833 l = 0; /* exit inner loop */ 1834 done = 1; /* exit outer loop */ 1835 } 1836 match = 1; 1837 break; 1838 1839 case O_PROBE_STATE: 1840 case O_CHECK_STATE: 1841 /* 1842 * dynamic rules are checked at the first 1843 * keep-state or check-state occurrence, 1844 * with the result being stored in dyn_dir. 1845 * The compiler introduces a PROBE_STATE 1846 * instruction for us when we have a 1847 * KEEP_STATE (because PROBE_STATE needs 1848 * to be run first). 1849 */ 1850 if (dyn_dir == MATCH_UNKNOWN && 1851 (q = ipfw_lookup_dyn_rule(&args->f_id, 1852 &dyn_dir, proto == IPPROTO_TCP ? 1853 TCP(ulp) : NULL)) 1854 != NULL) { 1855 /* 1856 * Found dynamic entry, update stats 1857 * and jump to the 'action' part of 1858 * the parent rule by setting 1859 * f, cmd, l and clearing cmdlen. 1860 */ 1861 q->pcnt++; 1862 q->bcnt += pktlen; 1863 /* XXX we would like to have f_pos 1864 * readily accessible in the dynamic 1865 * rule, instead of having to 1866 * lookup q->rule. 1867 */ 1868 f = q->rule; 1869 f_pos = ipfw_find_rule(chain, 1870 f->rulenum, f->id); 1871 cmd = ACTION_PTR(f); 1872 l = f->cmd_len - f->act_ofs; 1873 ipfw_dyn_unlock(); 1874 cmdlen = 0; 1875 match = 1; 1876 break; 1877 } 1878 /* 1879 * Dynamic entry not found. If CHECK_STATE, 1880 * skip to next rule, if PROBE_STATE just 1881 * ignore and continue with next opcode. 1882 */ 1883 if (cmd->opcode == O_CHECK_STATE) 1884 l = 0; /* exit inner loop */ 1885 match = 1; 1886 break; 1887 1888 case O_ACCEPT: 1889 retval = 0; /* accept */ 1890 l = 0; /* exit inner loop */ 1891 done = 1; /* exit outer loop */ 1892 break; 1893 1894 case O_PIPE: 1895 case O_QUEUE: 1896 set_match(args, f_pos, chain); 1897 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ? 1898 tablearg : cmd->arg1; 1899 if (cmd->opcode == O_PIPE) 1900 args->rule.info |= IPFW_IS_PIPE; 1901 if (V_fw_one_pass) 1902 args->rule.info |= IPFW_ONEPASS; 1903 retval = IP_FW_DUMMYNET; 1904 l = 0; /* exit inner loop */ 1905 done = 1; /* exit outer loop */ 1906 break; 1907 1908 case O_DIVERT: 1909 case O_TEE: 1910 if (args->eh) /* not on layer 2 */ 1911 break; 1912 /* otherwise this is terminal */ 1913 l = 0; /* exit inner loop */ 1914 done = 1; /* exit outer loop */ 1915 retval = (cmd->opcode == O_DIVERT) ? 1916 IP_FW_DIVERT : IP_FW_TEE; 1917 set_match(args, f_pos, chain); 1918 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ? 1919 tablearg : cmd->arg1; 1920 break; 1921 1922 case O_COUNT: 1923 f->pcnt++; /* update stats */ 1924 f->bcnt += pktlen; 1925 f->timestamp = time_uptime; 1926 l = 0; /* exit inner loop */ 1927 break; 1928 1929 case O_SKIPTO: 1930 f->pcnt++; /* update stats */ 1931 f->bcnt += pktlen; 1932 f->timestamp = time_uptime; 1933 /* If possible use cached f_pos (in f->next_rule), 1934 * whose version is written in f->next_rule 1935 * (horrible hacks to avoid changing the ABI). 1936 */ 1937 if (cmd->arg1 != IP_FW_TABLEARG && 1938 (uintptr_t)f->x_next == chain->id) { 1939 f_pos = (uintptr_t)f->next_rule; 1940 } else { 1941 int i = (cmd->arg1 == IP_FW_TABLEARG) ? 1942 tablearg : cmd->arg1; 1943 /* make sure we do not jump backward */ 1944 if (i <= f->rulenum) 1945 i = f->rulenum + 1; 1946 f_pos = ipfw_find_rule(chain, i, 0); 1947 /* update the cache */ 1948 if (cmd->arg1 != IP_FW_TABLEARG) { 1949 f->next_rule = 1950 (void *)(uintptr_t)f_pos; 1951 f->x_next = 1952 (void *)(uintptr_t)chain->id; 1953 } 1954 } 1955 /* 1956 * Skip disabled rules, and re-enter 1957 * the inner loop with the correct 1958 * f_pos, f, l and cmd. 1959 * Also clear cmdlen and skip_or 1960 */ 1961 for (; f_pos < chain->n_rules - 1 && 1962 (V_set_disable & 1963 (1 << chain->map[f_pos]->set)); 1964 f_pos++) 1965 ; 1966 /* prepare to enter the inner loop */ 1967 f = chain->map[f_pos]; 1968 l = f->cmd_len; 1969 cmd = f->cmd; 1970 match = 1; 1971 cmdlen = 0; 1972 skip_or = 0; 1973 break; 1974 1975 case O_REJECT: 1976 /* 1977 * Drop the packet and send a reject notice 1978 * if the packet is not ICMP (or is an ICMP 1979 * query), and it is not multicast/broadcast. 1980 */ 1981 if (hlen > 0 && is_ipv4 && offset == 0 && 1982 (proto != IPPROTO_ICMP || 1983 is_icmp_query(ICMP(ulp))) && 1984 !(m->m_flags & (M_BCAST|M_MCAST)) && 1985 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 1986 send_reject(args, cmd->arg1, iplen, ip); 1987 m = args->m; 1988 } 1989 /* FALLTHROUGH */ 1990#ifdef INET6 1991 case O_UNREACH6: 1992 if (hlen > 0 && is_ipv6 && 1993 ((offset & IP6F_OFF_MASK) == 0) && 1994 (proto != IPPROTO_ICMPV6 || 1995 (is_icmp6_query(args->f_id.flags) == 1)) && 1996 !(m->m_flags & (M_BCAST|M_MCAST)) && 1997 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 1998 send_reject6( 1999 args, cmd->arg1, hlen, 2000 (struct ip6_hdr *)ip); 2001 m = args->m; 2002 } 2003 /* FALLTHROUGH */ 2004#endif 2005 case O_DENY: 2006 retval = IP_FW_DENY; 2007 l = 0; /* exit inner loop */ 2008 done = 1; /* exit outer loop */ 2009 break; 2010 2011 case O_FORWARD_IP: 2012 if (args->eh) /* not valid on layer2 pkts */ 2013 break; 2014 if (!q || dyn_dir == MATCH_FORWARD) { 2015 struct sockaddr_in *sa; 2016 sa = &(((ipfw_insn_sa *)cmd)->sa); 2017 if (sa->sin_addr.s_addr == INADDR_ANY) { 2018 bcopy(sa, &args->hopstore, 2019 sizeof(*sa)); 2020 args->hopstore.sin_addr.s_addr = 2021 htonl(tablearg); 2022 args->next_hop = &args->hopstore; 2023 } else { 2024 args->next_hop = sa; 2025 } 2026 } 2027 retval = IP_FW_PASS; 2028 l = 0; /* exit inner loop */ 2029 done = 1; /* exit outer loop */ 2030 break; 2031 2032 case O_NETGRAPH: 2033 case O_NGTEE: 2034 set_match(args, f_pos, chain); 2035 args->rule.info = (cmd->arg1 == IP_FW_TABLEARG) ? 2036 tablearg : cmd->arg1; 2037 retval = (cmd->opcode == O_NETGRAPH) ? 2038 IP_FW_NETGRAPH : IP_FW_NGTEE; 2039 l = 0; /* exit inner loop */ 2040 done = 1; /* exit outer loop */ 2041 break; 2042 2043 case O_SETFIB: 2044 f->pcnt++; /* update stats */ 2045 f->bcnt += pktlen; 2046 f->timestamp = time_uptime; 2047 M_SETFIB(m, cmd->arg1); 2048 args->f_id.fib = cmd->arg1; 2049 l = 0; /* exit inner loop */ 2050 break; 2051 2052 case O_NAT: 2053 if (!IPFW_NAT_LOADED) { 2054 retval = IP_FW_DENY; 2055 } else { 2056 struct cfg_nat *t; 2057 int nat_id; 2058 2059 set_match(args, f_pos, chain); 2060 t = ((ipfw_insn_nat *)cmd)->nat; 2061 if (t == NULL) { 2062 nat_id = (cmd->arg1 == IP_FW_TABLEARG) ? 2063 tablearg : cmd->arg1; 2064 t = (*lookup_nat_ptr)(&chain->nat, nat_id); 2065 2066 if (t == NULL) { 2067 retval = IP_FW_DENY; 2068 l = 0; /* exit inner loop */ 2069 done = 1; /* exit outer loop */ 2070 break; 2071 } 2072 if (cmd->arg1 != IP_FW_TABLEARG) 2073 ((ipfw_insn_nat *)cmd)->nat = t; 2074 } 2075 retval = ipfw_nat_ptr(args, t, m); 2076 } 2077 l = 0; /* exit inner loop */ 2078 done = 1; /* exit outer loop */ 2079 break; 2080 2081 case O_REASS: { 2082 int ip_off; 2083 2084 f->pcnt++; 2085 f->bcnt += pktlen; 2086 l = 0; /* in any case exit inner loop */ 2087 ip_off = ntohs(ip->ip_off); 2088 2089 /* if not fragmented, go to next rule */ 2090 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0) 2091 break; 2092 /* 2093 * ip_reass() expects len & off in host 2094 * byte order. 2095 */ 2096 SET_HOST_IPLEN(ip); 2097 2098 args->m = m = ip_reass(m); 2099 2100 /* 2101 * do IP header checksum fixup. 2102 */ 2103 if (m == NULL) { /* fragment got swallowed */ 2104 retval = IP_FW_DENY; 2105 } else { /* good, packet complete */ 2106 int hlen; 2107 2108 ip = mtod(m, struct ip *); 2109 hlen = ip->ip_hl << 2; 2110 SET_NET_IPLEN(ip); 2111 ip->ip_sum = 0; 2112 if (hlen == sizeof(struct ip)) 2113 ip->ip_sum = in_cksum_hdr(ip); 2114 else 2115 ip->ip_sum = in_cksum(m, hlen); 2116 retval = IP_FW_REASS; 2117 set_match(args, f_pos, chain); 2118 } 2119 done = 1; /* exit outer loop */ 2120 break; 2121 } 2122 2123 default: 2124 panic("-- unknown opcode %d\n", cmd->opcode); 2125 } /* end of switch() on opcodes */ 2126 /* 2127 * if we get here with l=0, then match is irrelevant. 2128 */ 2129 2130 if (cmd->len & F_NOT) 2131 match = !match; 2132 2133 if (match) { 2134 if (cmd->len & F_OR) 2135 skip_or = 1; 2136 } else { 2137 if (!(cmd->len & F_OR)) /* not an OR block, */ 2138 break; /* try next rule */ 2139 } 2140 2141 } /* end of inner loop, scan opcodes */ 2142 2143 if (done) 2144 break; 2145 2146/* next_rule:; */ /* try next rule */ 2147 2148 } /* end of outer for, scan rules */ 2149 2150 if (done) { 2151 struct ip_fw *rule = chain->map[f_pos]; 2152 /* Update statistics */ 2153 rule->pcnt++; 2154 rule->bcnt += pktlen; 2155 rule->timestamp = time_uptime; 2156 } else { 2157 retval = IP_FW_DENY; 2158 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 2159 } 2160 IPFW_RUNLOCK(chain); 2161 if (ucred_cache != NULL) 2162 crfree(ucred_cache); 2163 return (retval); 2164 2165pullup_failed: 2166 if (V_fw_verbose) 2167 printf("ipfw: pullup failed\n"); 2168 return (IP_FW_DENY); 2169} 2170 2171/* 2172 * Module and VNET glue 2173 */ 2174 2175/* 2176 * Stuff that must be initialised only on boot or module load 2177 */ 2178static int 2179ipfw_init(void) 2180{ 2181 int error = 0; 2182 2183 ipfw_dyn_attach(); 2184 /* 2185 * Only print out this stuff the first time around, 2186 * when called from the sysinit code. 2187 */ 2188 printf("ipfw2 " 2189#ifdef INET6 2190 "(+ipv6) " 2191#endif 2192 "initialized, divert %s, nat %s, " 2193 "rule-based forwarding " 2194#ifdef IPFIREWALL_FORWARD 2195 "enabled, " 2196#else 2197 "disabled, " 2198#endif 2199 "default to %s, logging ", 2200#ifdef IPDIVERT 2201 "enabled", 2202#else 2203 "loadable", 2204#endif 2205#ifdef IPFIREWALL_NAT 2206 "enabled", 2207#else 2208 "loadable", 2209#endif 2210 default_to_accept ? "accept" : "deny"); 2211 2212 /* 2213 * Note: V_xxx variables can be accessed here but the vnet specific 2214 * initializer may not have been called yet for the VIMAGE case. 2215 * Tuneables will have been processed. We will print out values for 2216 * the default vnet. 2217 * XXX This should all be rationalized AFTER 8.0 2218 */ 2219 if (V_fw_verbose == 0) 2220 printf("disabled\n"); 2221 else if (V_verbose_limit == 0) 2222 printf("unlimited\n"); 2223 else 2224 printf("limited to %d packets/entry by default\n", 2225 V_verbose_limit); 2226 2227 ipfw_log_bpf(1); /* init */ 2228 return (error); 2229} 2230 2231/* 2232 * Called for the removal of the last instance only on module unload. 2233 */ 2234static void 2235ipfw_destroy(void) 2236{ 2237 2238 ipfw_log_bpf(0); /* uninit */ 2239 ipfw_dyn_detach(); 2240 printf("IP firewall unloaded\n"); 2241} 2242 2243/* 2244 * Stuff that must be initialized for every instance 2245 * (including the first of course). 2246 */ 2247static int 2248vnet_ipfw_init(const void *unused) 2249{ 2250 int error; 2251 struct ip_fw *rule = NULL; 2252 struct ip_fw_chain *chain; 2253 2254 chain = &V_layer3_chain; 2255 2256 /* First set up some values that are compile time options */ 2257 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 2258 V_fw_deny_unknown_exthdrs = 1; 2259#ifdef IPFIREWALL_VERBOSE 2260 V_fw_verbose = 1; 2261#endif 2262#ifdef IPFIREWALL_VERBOSE_LIMIT 2263 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 2264#endif 2265#ifdef IPFIREWALL_NAT 2266 LIST_INIT(&chain->nat); 2267#endif 2268 2269 /* insert the default rule and create the initial map */ 2270 chain->n_rules = 1; 2271 chain->static_len = sizeof(struct ip_fw); 2272 chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_NOWAIT | M_ZERO); 2273 if (chain->map) 2274 rule = malloc(chain->static_len, M_IPFW, M_NOWAIT | M_ZERO); 2275 if (rule == NULL) { 2276 if (chain->map) 2277 free(chain->map, M_IPFW); 2278 printf("ipfw2: ENOSPC initializing default rule " 2279 "(support disabled)\n"); 2280 return (ENOSPC); 2281 } 2282 error = ipfw_init_tables(chain); 2283 if (error) { 2284 panic("init_tables"); /* XXX Marko fix this ! */ 2285 } 2286 2287 /* fill and insert the default rule */ 2288 rule->act_ofs = 0; 2289 rule->rulenum = IPFW_DEFAULT_RULE; 2290 rule->cmd_len = 1; 2291 rule->set = RESVD_SET; 2292 rule->cmd[0].len = 1; 2293 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY; 2294 chain->rules = chain->default_rule = chain->map[0] = rule; 2295 chain->id = rule->id = 1; 2296 2297 IPFW_LOCK_INIT(chain); 2298 ipfw_dyn_init(); 2299 2300 /* First set up some values that are compile time options */ 2301 V_ipfw_vnet_ready = 1; /* Open for business */ 2302 2303 /* 2304 * Hook the sockopt handler, and the layer2 (V_ip_fw_chk_ptr) 2305 * and pfil hooks for ipv4 and ipv6. Even if the latter two fail 2306 * we still keep the module alive because the sockopt and 2307 * layer2 paths are still useful. 2308 * ipfw[6]_hook return 0 on success, ENOENT on failure, 2309 * so we can ignore the exact return value and just set a flag. 2310 * 2311 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so 2312 * changes in the underlying (per-vnet) variables trigger 2313 * immediate hook()/unhook() calls. 2314 * In layer2 we have the same behaviour, except that V_ether_ipfw 2315 * is checked on each packet because there are no pfil hooks. 2316 */ 2317 V_ip_fw_ctl_ptr = ipfw_ctl; 2318 V_ip_fw_chk_ptr = ipfw_chk; 2319 error = ipfw_attach_hooks(1); 2320 return (error); 2321} 2322 2323/* 2324 * Called for the removal of each instance. 2325 */ 2326static int 2327vnet_ipfw_uninit(const void *unused) 2328{ 2329 struct ip_fw *reap, *rule; 2330 struct ip_fw_chain *chain = &V_layer3_chain; 2331 int i; 2332 2333 V_ipfw_vnet_ready = 0; /* tell new callers to go away */ 2334 /* 2335 * disconnect from ipv4, ipv6, layer2 and sockopt. 2336 * Then grab, release and grab again the WLOCK so we make 2337 * sure the update is propagated and nobody will be in. 2338 */ 2339 (void)ipfw_attach_hooks(0 /* detach */); 2340 V_ip_fw_chk_ptr = NULL; 2341 V_ip_fw_ctl_ptr = NULL; 2342 IPFW_UH_WLOCK(chain); 2343 IPFW_UH_WUNLOCK(chain); 2344 IPFW_UH_WLOCK(chain); 2345 2346 IPFW_WLOCK(chain); 2347 IPFW_WUNLOCK(chain); 2348 IPFW_WLOCK(chain); 2349 2350 ipfw_dyn_uninit(0); /* run the callout_drain */ 2351 ipfw_flush_tables(chain); 2352 reap = NULL; 2353 for (i = 0; i < chain->n_rules; i++) { 2354 rule = chain->map[i]; 2355 rule->x_next = reap; 2356 reap = rule; 2357 } 2358 if (chain->map) 2359 free(chain->map, M_IPFW); 2360 IPFW_WUNLOCK(chain); 2361 IPFW_UH_WUNLOCK(chain); 2362 if (reap != NULL) 2363 ipfw_reap_rules(reap); 2364 IPFW_LOCK_DESTROY(chain); 2365 ipfw_dyn_uninit(1); /* free the remaining parts */ 2366 return 0; 2367} 2368 2369/* 2370 * Module event handler. 2371 * In general we have the choice of handling most of these events by the 2372 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to 2373 * use the SYSINIT handlers as they are more capable of expressing the 2374 * flow of control during module and vnet operations, so this is just 2375 * a skeleton. Note there is no SYSINIT equivalent of the module 2376 * SHUTDOWN handler, but we don't have anything to do in that case anyhow. 2377 */ 2378static int 2379ipfw_modevent(module_t mod, int type, void *unused) 2380{ 2381 int err = 0; 2382 2383 switch (type) { 2384 case MOD_LOAD: 2385 /* Called once at module load or 2386 * system boot if compiled in. */ 2387 break; 2388 case MOD_QUIESCE: 2389 /* Called before unload. May veto unloading. */ 2390 break; 2391 case MOD_UNLOAD: 2392 /* Called during unload. */ 2393 break; 2394 case MOD_SHUTDOWN: 2395 /* Called during system shutdown. */ 2396 break; 2397 default: 2398 err = EOPNOTSUPP; 2399 break; 2400 } 2401 return err; 2402} 2403 2404static moduledata_t ipfwmod = { 2405 "ipfw", 2406 ipfw_modevent, 2407 0 2408}; 2409 2410/* Define startup order. */ 2411#define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_IFATTACHDOMAIN 2412#define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */ 2413#define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */ 2414#define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */ 2415 2416DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER); 2417MODULE_VERSION(ipfw, 2); 2418/* should declare some dependencies here */ 2419 2420/* 2421 * Starting up. Done in order after ipfwmod() has been called. 2422 * VNET_SYSINIT is also called for each existing vnet and each new vnet. 2423 */ 2424SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 2425 ipfw_init, NULL); 2426VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 2427 vnet_ipfw_init, NULL); 2428 2429/* 2430 * Closing up shop. These are done in REVERSE ORDER, but still 2431 * after ipfwmod() has been called. Not called on reboot. 2432 * VNET_SYSUNINIT is also called for each exiting vnet as it exits. 2433 * or when the module is unloaded. 2434 */ 2435SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 2436 ipfw_destroy, NULL); 2437VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 2438 vnet_ipfw_uninit, NULL); 2439/* end of file */ 2440