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/10/sys/netpfil/ipfw/ip_fw2.c 331202 2018-03-19 09:54:16Z ae $"); 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/pfil.h> 64#include <net/vnet.h> 65 66#include <netpfil/pf/pf_mtag.h> 67 68#include <netinet/in.h> 69#include <netinet/in_var.h> 70#include <netinet/in_pcb.h> 71#include <netinet/ip.h> 72#include <netinet/ip_var.h> 73#include <netinet/ip_icmp.h> 74#include <netinet/ip_fw.h> 75#include <netinet/ip_carp.h> 76#include <netinet/pim.h> 77#include <netinet/tcp_var.h> 78#include <netinet/udp.h> 79#include <netinet/udp_var.h> 80#include <netinet/sctp.h> 81 82#include <netinet/ip6.h> 83#include <netinet/icmp6.h> 84#ifdef INET6 85#include <netinet6/in6_pcb.h> 86#include <netinet6/scope6_var.h> 87#include <netinet6/ip6_var.h> 88#endif 89 90#include <net/if_gre.h> /* for struct grehdr */ 91 92#include <netpfil/ipfw/ip_fw_private.h> 93 94#include <machine/in_cksum.h> /* XXX for in_cksum */ 95 96#ifdef MAC 97#include <security/mac/mac_framework.h> 98#endif 99 100/* 101 * static variables followed by global ones. 102 * All ipfw global variables are here. 103 */ 104 105/* ipfw_vnet_ready controls when we are open for business */ 106static VNET_DEFINE(int, ipfw_vnet_ready) = 0; 107#define V_ipfw_vnet_ready VNET(ipfw_vnet_ready) 108 109static VNET_DEFINE(int, fw_deny_unknown_exthdrs); 110#define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs) 111 112static VNET_DEFINE(int, fw_permit_single_frag6) = 1; 113#define V_fw_permit_single_frag6 VNET(fw_permit_single_frag6) 114 115#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 116static int default_to_accept = 1; 117#else 118static int default_to_accept; 119#endif 120 121VNET_DEFINE(int, autoinc_step); 122VNET_DEFINE(int, fw_one_pass) = 1; 123 124VNET_DEFINE(unsigned int, fw_tables_max); 125/* Use 128 tables by default */ 126static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT; 127 128/* 129 * Each rule belongs to one of 32 different sets (0..31). 130 * The variable set_disable contains one bit per set. 131 * If the bit is set, all rules in the corresponding set 132 * are disabled. Set RESVD_SET(31) is reserved for the default rule 133 * and rules that are not deleted by the flush command, 134 * and CANNOT be disabled. 135 * Rules in set RESVD_SET can only be deleted individually. 136 */ 137VNET_DEFINE(u_int32_t, set_disable); 138#define V_set_disable VNET(set_disable) 139 140VNET_DEFINE(int, fw_verbose); 141/* counter for ipfw_log(NULL...) */ 142VNET_DEFINE(u_int64_t, norule_counter); 143VNET_DEFINE(int, verbose_limit); 144 145/* layer3_chain contains the list of rules for layer 3 */ 146VNET_DEFINE(struct ip_fw_chain, layer3_chain); 147 148VNET_DEFINE(int, ipfw_nat_ready) = 0; 149 150ipfw_nat_t *ipfw_nat_ptr = NULL; 151struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int); 152ipfw_nat_cfg_t *ipfw_nat_cfg_ptr; 153ipfw_nat_cfg_t *ipfw_nat_del_ptr; 154ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr; 155ipfw_nat_cfg_t *ipfw_nat_get_log_ptr; 156 157#ifdef SYSCTL_NODE 158uint32_t dummy_def = IPFW_DEFAULT_RULE; 159static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS); 160 161SYSBEGIN(f3) 162 163SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 164SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 165 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0, 166 "Only do a single pass through ipfw when using dummynet(4)"); 167SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, 168 CTLFLAG_RW, &VNET_NAME(autoinc_step), 0, 169 "Rule number auto-increment step"); 170SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose, 171 CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0, 172 "Log matches to ipfw rules"); 173SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, 174 CTLFLAG_RW, &VNET_NAME(verbose_limit), 0, 175 "Set upper limit of matches of ipfw rules logged"); 176SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD, 177 &dummy_def, 0, 178 "The default/max possible rule number."); 179SYSCTL_VNET_PROC(_net_inet_ip_fw, OID_AUTO, tables_max, 180 CTLTYPE_UINT|CTLFLAG_RW, 0, 0, sysctl_ipfw_table_num, "IU", 181 "Maximum number of tables"); 182SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN, 183 &default_to_accept, 0, 184 "Make the default rule accept all packets."); 185TUNABLE_INT("net.inet.ip.fw.default_to_accept", &default_to_accept); 186TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables); 187SYSCTL_VNET_INT(_net_inet_ip_fw, OID_AUTO, static_count, 188 CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0, 189 "Number of static rules"); 190 191#ifdef INET6 192SYSCTL_DECL(_net_inet6_ip6); 193SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 194SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs, 195 CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_deny_unknown_exthdrs), 0, 196 "Deny packets with unknown IPv6 Extension Headers"); 197SYSCTL_VNET_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6, 198 CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_permit_single_frag6), 0, 199 "Permit single packet IPv6 fragments"); 200#endif /* INET6 */ 201 202SYSEND 203 204#endif /* SYSCTL_NODE */ 205 206 207/* 208 * Some macros used in the various matching options. 209 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 210 * Other macros just cast void * into the appropriate type 211 */ 212#define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 213#define TCP(p) ((struct tcphdr *)(p)) 214#define SCTP(p) ((struct sctphdr *)(p)) 215#define UDP(p) ((struct udphdr *)(p)) 216#define ICMP(p) ((struct icmphdr *)(p)) 217#define ICMP6(p) ((struct icmp6_hdr *)(p)) 218 219static __inline int 220icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 221{ 222 int type = icmp->icmp_type; 223 224 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 225} 226 227#define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 228 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 229 230static int 231is_icmp_query(struct icmphdr *icmp) 232{ 233 int type = icmp->icmp_type; 234 235 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 236} 237#undef TT 238 239/* 240 * The following checks use two arrays of 8 or 16 bits to store the 241 * bits that we want set or clear, respectively. They are in the 242 * low and high half of cmd->arg1 or cmd->d[0]. 243 * 244 * We scan options and store the bits we find set. We succeed if 245 * 246 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 247 * 248 * The code is sometimes optimized not to store additional variables. 249 */ 250 251static int 252flags_match(ipfw_insn *cmd, u_int8_t bits) 253{ 254 u_char want_clear; 255 bits = ~bits; 256 257 if ( ((cmd->arg1 & 0xff) & bits) != 0) 258 return 0; /* some bits we want set were clear */ 259 want_clear = (cmd->arg1 >> 8) & 0xff; 260 if ( (want_clear & bits) != want_clear) 261 return 0; /* some bits we want clear were set */ 262 return 1; 263} 264 265static int 266ipopts_match(struct ip *ip, ipfw_insn *cmd) 267{ 268 int optlen, bits = 0; 269 u_char *cp = (u_char *)(ip + 1); 270 int x = (ip->ip_hl << 2) - sizeof (struct ip); 271 272 for (; x > 0; x -= optlen, cp += optlen) { 273 int opt = cp[IPOPT_OPTVAL]; 274 275 if (opt == IPOPT_EOL) 276 break; 277 if (opt == IPOPT_NOP) 278 optlen = 1; 279 else { 280 optlen = cp[IPOPT_OLEN]; 281 if (optlen <= 0 || optlen > x) 282 return 0; /* invalid or truncated */ 283 } 284 switch (opt) { 285 286 default: 287 break; 288 289 case IPOPT_LSRR: 290 bits |= IP_FW_IPOPT_LSRR; 291 break; 292 293 case IPOPT_SSRR: 294 bits |= IP_FW_IPOPT_SSRR; 295 break; 296 297 case IPOPT_RR: 298 bits |= IP_FW_IPOPT_RR; 299 break; 300 301 case IPOPT_TS: 302 bits |= IP_FW_IPOPT_TS; 303 break; 304 } 305 } 306 return (flags_match(cmd, bits)); 307} 308 309static int 310tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 311{ 312 int optlen, bits = 0; 313 u_char *cp = (u_char *)(tcp + 1); 314 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 315 316 for (; x > 0; x -= optlen, cp += optlen) { 317 int opt = cp[0]; 318 if (opt == TCPOPT_EOL) 319 break; 320 if (opt == TCPOPT_NOP) 321 optlen = 1; 322 else { 323 optlen = cp[1]; 324 if (optlen <= 0) 325 break; 326 } 327 328 switch (opt) { 329 330 default: 331 break; 332 333 case TCPOPT_MAXSEG: 334 bits |= IP_FW_TCPOPT_MSS; 335 break; 336 337 case TCPOPT_WINDOW: 338 bits |= IP_FW_TCPOPT_WINDOW; 339 break; 340 341 case TCPOPT_SACK_PERMITTED: 342 case TCPOPT_SACK: 343 bits |= IP_FW_TCPOPT_SACK; 344 break; 345 346 case TCPOPT_TIMESTAMP: 347 bits |= IP_FW_TCPOPT_TS; 348 break; 349 350 } 351 } 352 return (flags_match(cmd, bits)); 353} 354 355static int 356iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain, uint32_t *tablearg) 357{ 358 if (ifp == NULL) /* no iface with this packet, match fails */ 359 return 0; 360 /* Check by name or by IP address */ 361 if (cmd->name[0] != '\0') { /* match by name */ 362 if (cmd->name[0] == '\1') /* use tablearg to match */ 363 return ipfw_lookup_table_extended(chain, cmd->p.glob, 364 ifp->if_xname, tablearg, IPFW_TABLE_INTERFACE); 365 /* Check name */ 366 if (cmd->p.glob) { 367 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 368 return(1); 369 } else { 370 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 371 return(1); 372 } 373 } else { 374#ifdef __FreeBSD__ /* and OSX too ? */ 375 struct ifaddr *ia; 376 377 if_addr_rlock(ifp); 378 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 379 if (ia->ifa_addr->sa_family != AF_INET) 380 continue; 381 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 382 (ia->ifa_addr))->sin_addr.s_addr) { 383 if_addr_runlock(ifp); 384 return(1); /* match */ 385 } 386 } 387 if_addr_runlock(ifp); 388#endif /* __FreeBSD__ */ 389 } 390 return(0); /* no match, fail ... */ 391} 392 393/* 394 * The verify_path function checks if a route to the src exists and 395 * if it is reachable via ifp (when provided). 396 * 397 * The 'verrevpath' option checks that the interface that an IP packet 398 * arrives on is the same interface that traffic destined for the 399 * packet's source address would be routed out of. 400 * The 'versrcreach' option just checks that the source address is 401 * reachable via any route (except default) in the routing table. 402 * These two are a measure to block forged packets. This is also 403 * commonly known as "anti-spoofing" or Unicast Reverse Path 404 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 405 * is purposely reminiscent of the Cisco IOS command, 406 * 407 * ip verify unicast reverse-path 408 * ip verify unicast source reachable-via any 409 * 410 * which implements the same functionality. But note that the syntax 411 * is misleading, and the check may be performed on all IP packets 412 * whether unicast, multicast, or broadcast. 413 */ 414static int 415verify_path(struct in_addr src, struct ifnet *ifp, u_int fib) 416{ 417#ifndef __FreeBSD__ 418 return 0; 419#else 420 struct route ro; 421 struct sockaddr_in *dst; 422 423 bzero(&ro, sizeof(ro)); 424 425 dst = (struct sockaddr_in *)&(ro.ro_dst); 426 dst->sin_family = AF_INET; 427 dst->sin_len = sizeof(*dst); 428 dst->sin_addr = src; 429 in_rtalloc_ign(&ro, 0, fib); 430 431 if (ro.ro_rt == NULL) 432 return 0; 433 434 /* 435 * If ifp is provided, check for equality with rtentry. 436 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 437 * in order to pass packets injected back by if_simloop(): 438 * if useloopback == 1 routing entry (via lo0) for our own address 439 * may exist, so we need to handle routing assymetry. 440 */ 441 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 442 RTFREE(ro.ro_rt); 443 return 0; 444 } 445 446 /* if no ifp provided, check if rtentry is not default route */ 447 if (ifp == NULL && 448 satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) { 449 RTFREE(ro.ro_rt); 450 return 0; 451 } 452 453 /* or if this is a blackhole/reject route */ 454 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 455 RTFREE(ro.ro_rt); 456 return 0; 457 } 458 459 /* found valid route */ 460 RTFREE(ro.ro_rt); 461 return 1; 462#endif /* __FreeBSD__ */ 463} 464 465#ifdef INET6 466/* 467 * ipv6 specific rules here... 468 */ 469static __inline int 470icmp6type_match (int type, ipfw_insn_u32 *cmd) 471{ 472 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 473} 474 475static int 476flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 477{ 478 int i; 479 for (i=0; i <= cmd->o.arg1; ++i ) 480 if (curr_flow == cmd->d[i] ) 481 return 1; 482 return 0; 483} 484 485/* support for IP6_*_ME opcodes */ 486static int 487search_ip6_addr_net (struct in6_addr * ip6_addr) 488{ 489 struct ifnet *mdc; 490 struct ifaddr *mdc2; 491 struct in6_ifaddr *fdm; 492 struct in6_addr copia; 493 494 TAILQ_FOREACH(mdc, &V_ifnet, if_link) { 495 if_addr_rlock(mdc); 496 TAILQ_FOREACH(mdc2, &mdc->if_addrhead, ifa_link) { 497 if (mdc2->ifa_addr->sa_family == AF_INET6) { 498 fdm = (struct in6_ifaddr *)mdc2; 499 copia = fdm->ia_addr.sin6_addr; 500 /* need for leaving scope_id in the sock_addr */ 501 in6_clearscope(&copia); 502 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia)) { 503 if_addr_runlock(mdc); 504 return 1; 505 } 506 } 507 } 508 if_addr_runlock(mdc); 509 } 510 return 0; 511} 512 513static int 514verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib) 515{ 516 struct route_in6 ro; 517 struct sockaddr_in6 *dst; 518 519 bzero(&ro, sizeof(ro)); 520 521 dst = (struct sockaddr_in6 * )&(ro.ro_dst); 522 dst->sin6_family = AF_INET6; 523 dst->sin6_len = sizeof(*dst); 524 dst->sin6_addr = *src; 525 526 in6_rtalloc_ign(&ro, 0, fib); 527 if (ro.ro_rt == NULL) 528 return 0; 529 530 /* 531 * if ifp is provided, check for equality with rtentry 532 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 533 * to support the case of sending packets to an address of our own. 534 * (where the former interface is the first argument of if_simloop() 535 * (=ifp), the latter is lo0) 536 */ 537 if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) { 538 RTFREE(ro.ro_rt); 539 return 0; 540 } 541 542 /* if no ifp provided, check if rtentry is not default route */ 543 if (ifp == NULL && 544 IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) { 545 RTFREE(ro.ro_rt); 546 return 0; 547 } 548 549 /* or if this is a blackhole/reject route */ 550 if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 551 RTFREE(ro.ro_rt); 552 return 0; 553 } 554 555 /* found valid route */ 556 RTFREE(ro.ro_rt); 557 return 1; 558 559} 560 561static int 562is_icmp6_query(int icmp6_type) 563{ 564 if ((icmp6_type <= ICMP6_MAXTYPE) && 565 (icmp6_type == ICMP6_ECHO_REQUEST || 566 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 567 icmp6_type == ICMP6_WRUREQUEST || 568 icmp6_type == ICMP6_FQDN_QUERY || 569 icmp6_type == ICMP6_NI_QUERY)) 570 return (1); 571 572 return (0); 573} 574 575static void 576send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 577{ 578 struct mbuf *m; 579 580 m = args->m; 581 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 582 struct tcphdr *tcp; 583 tcp = (struct tcphdr *)((char *)ip6 + hlen); 584 585 if ((tcp->th_flags & TH_RST) == 0) { 586 struct mbuf *m0; 587 m0 = ipfw_send_pkt(args->m, &(args->f_id), 588 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 589 tcp->th_flags | TH_RST); 590 if (m0 != NULL) 591 ip6_output(m0, NULL, NULL, 0, NULL, NULL, 592 NULL); 593 } 594 FREE_PKT(m); 595 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */ 596#if 0 597 /* 598 * Unlike above, the mbufs need to line up with the ip6 hdr, 599 * as the contents are read. We need to m_adj() the 600 * needed amount. 601 * The mbuf will however be thrown away so we can adjust it. 602 * Remember we did an m_pullup on it already so we 603 * can make some assumptions about contiguousness. 604 */ 605 if (args->L3offset) 606 m_adj(m, args->L3offset); 607#endif 608 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 609 } else 610 FREE_PKT(m); 611 612 args->m = NULL; 613} 614 615#endif /* INET6 */ 616 617 618/* 619 * sends a reject message, consuming the mbuf passed as an argument. 620 */ 621static void 622send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip) 623{ 624 625#if 0 626 /* XXX When ip is not guaranteed to be at mtod() we will 627 * need to account for this */ 628 * The mbuf will however be thrown away so we can adjust it. 629 * Remember we did an m_pullup on it already so we 630 * can make some assumptions about contiguousness. 631 */ 632 if (args->L3offset) 633 m_adj(m, args->L3offset); 634#endif 635 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */ 636 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 637 } else if (args->f_id.proto == IPPROTO_TCP) { 638 struct tcphdr *const tcp = 639 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 640 if ( (tcp->th_flags & TH_RST) == 0) { 641 struct mbuf *m; 642 m = ipfw_send_pkt(args->m, &(args->f_id), 643 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 644 tcp->th_flags | TH_RST); 645 if (m != NULL) 646 ip_output(m, NULL, NULL, 0, NULL, NULL); 647 } 648 FREE_PKT(args->m); 649 } else 650 FREE_PKT(args->m); 651 args->m = NULL; 652} 653 654/* 655 * Support for uid/gid/jail lookup. These tests are expensive 656 * (because we may need to look into the list of active sockets) 657 * so we cache the results. ugid_lookupp is 0 if we have not 658 * yet done a lookup, 1 if we succeeded, and -1 if we tried 659 * and failed. The function always returns the match value. 660 * We could actually spare the variable and use *uc, setting 661 * it to '(void *)check_uidgid if we have no info, NULL if 662 * we tried and failed, or any other value if successful. 663 */ 664static int 665check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp, 666 struct ucred **uc) 667{ 668#ifndef __FreeBSD__ 669 /* XXX */ 670 return cred_check(insn, proto, oif, 671 dst_ip, dst_port, src_ip, src_port, 672 (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb); 673#else /* FreeBSD */ 674 struct in_addr src_ip, dst_ip; 675 struct inpcbinfo *pi; 676 struct ipfw_flow_id *id; 677 struct inpcb *pcb, *inp; 678 struct ifnet *oif; 679 int lookupflags; 680 int match; 681 682 id = &args->f_id; 683 inp = args->inp; 684 oif = args->oif; 685 686 /* 687 * Check to see if the UDP or TCP stack supplied us with 688 * the PCB. If so, rather then holding a lock and looking 689 * up the PCB, we can use the one that was supplied. 690 */ 691 if (inp && *ugid_lookupp == 0) { 692 INP_LOCK_ASSERT(inp); 693 if (inp->inp_socket != NULL) { 694 *uc = crhold(inp->inp_cred); 695 *ugid_lookupp = 1; 696 } else 697 *ugid_lookupp = -1; 698 } 699 /* 700 * If we have already been here and the packet has no 701 * PCB entry associated with it, then we can safely 702 * assume that this is a no match. 703 */ 704 if (*ugid_lookupp == -1) 705 return (0); 706 if (id->proto == IPPROTO_TCP) { 707 lookupflags = 0; 708 pi = &V_tcbinfo; 709 } else if (id->proto == IPPROTO_UDP) { 710 lookupflags = INPLOOKUP_WILDCARD; 711 pi = &V_udbinfo; 712 } else 713 return 0; 714 lookupflags |= INPLOOKUP_RLOCKPCB; 715 match = 0; 716 if (*ugid_lookupp == 0) { 717 if (id->addr_type == 6) { 718#ifdef INET6 719 if (oif == NULL) 720 pcb = in6_pcblookup_mbuf(pi, 721 &id->src_ip6, htons(id->src_port), 722 &id->dst_ip6, htons(id->dst_port), 723 lookupflags, oif, args->m); 724 else 725 pcb = in6_pcblookup_mbuf(pi, 726 &id->dst_ip6, htons(id->dst_port), 727 &id->src_ip6, htons(id->src_port), 728 lookupflags, oif, args->m); 729#else 730 *ugid_lookupp = -1; 731 return (0); 732#endif 733 } else { 734 src_ip.s_addr = htonl(id->src_ip); 735 dst_ip.s_addr = htonl(id->dst_ip); 736 if (oif == NULL) 737 pcb = in_pcblookup_mbuf(pi, 738 src_ip, htons(id->src_port), 739 dst_ip, htons(id->dst_port), 740 lookupflags, oif, args->m); 741 else 742 pcb = in_pcblookup_mbuf(pi, 743 dst_ip, htons(id->dst_port), 744 src_ip, htons(id->src_port), 745 lookupflags, oif, args->m); 746 } 747 if (pcb != NULL) { 748 INP_RLOCK_ASSERT(pcb); 749 *uc = crhold(pcb->inp_cred); 750 *ugid_lookupp = 1; 751 INP_RUNLOCK(pcb); 752 } 753 if (*ugid_lookupp == 0) { 754 /* 755 * We tried and failed, set the variable to -1 756 * so we will not try again on this packet. 757 */ 758 *ugid_lookupp = -1; 759 return (0); 760 } 761 } 762 if (insn->o.opcode == O_UID) 763 match = ((*uc)->cr_uid == (uid_t)insn->d[0]); 764 else if (insn->o.opcode == O_GID) 765 match = groupmember((gid_t)insn->d[0], *uc); 766 else if (insn->o.opcode == O_JAIL) 767 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]); 768 return (match); 769#endif /* __FreeBSD__ */ 770} 771 772/* 773 * Helper function to set args with info on the rule after the matching 774 * one. slot is precise, whereas we guess rule_id as they are 775 * assigned sequentially. 776 */ 777static inline void 778set_match(struct ip_fw_args *args, int slot, 779 struct ip_fw_chain *chain) 780{ 781 args->rule.chain_id = chain->id; 782 args->rule.slot = slot + 1; /* we use 0 as a marker */ 783 args->rule.rule_id = 1 + chain->map[slot]->id; 784 args->rule.rulenum = chain->map[slot]->rulenum; 785} 786 787/* 788 * Helper function to enable cached rule lookups using 789 * x_next and next_rule fields in ipfw rule. 790 */ 791static int 792jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 793 int tablearg, int jump_backwards) 794{ 795 int f_pos; 796 797 /* If possible use cached f_pos (in f->next_rule), 798 * whose version is written in f->next_rule 799 * (horrible hacks to avoid changing the ABI). 800 */ 801 if (num != IP_FW_TABLEARG && (uintptr_t)f->x_next == chain->id) 802 f_pos = (uintptr_t)f->next_rule; 803 else { 804 int i = IP_FW_ARG_TABLEARG(num); 805 /* make sure we do not jump backward */ 806 if (jump_backwards == 0 && i <= f->rulenum) 807 i = f->rulenum + 1; 808 f_pos = ipfw_find_rule(chain, i, 0); 809 /* update the cache */ 810 if (num != IP_FW_TABLEARG) { 811 f->next_rule = (void *)(uintptr_t)f_pos; 812 f->x_next = (void *)(uintptr_t)chain->id; 813 } 814 } 815 816 return (f_pos); 817} 818 819/* 820 * The main check routine for the firewall. 821 * 822 * All arguments are in args so we can modify them and return them 823 * back to the caller. 824 * 825 * Parameters: 826 * 827 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 828 * Starts with the IP header. 829 * args->eh (in) Mac header if present, NULL for layer3 packet. 830 * args->L3offset Number of bytes bypassed if we came from L2. 831 * e.g. often sizeof(eh) ** NOTYET ** 832 * args->oif Outgoing interface, NULL if packet is incoming. 833 * The incoming interface is in the mbuf. (in) 834 * args->divert_rule (in/out) 835 * Skip up to the first rule past this rule number; 836 * upon return, non-zero port number for divert or tee. 837 * 838 * args->rule Pointer to the last matching rule (in/out) 839 * args->next_hop Socket we are forwarding to (out). 840 * args->next_hop6 IPv6 next hop we are forwarding to (out). 841 * args->f_id Addresses grabbed from the packet (out) 842 * args->rule.info a cookie depending on rule action 843 * 844 * Return value: 845 * 846 * IP_FW_PASS the packet must be accepted 847 * IP_FW_DENY the packet must be dropped 848 * IP_FW_DIVERT divert packet, port in m_tag 849 * IP_FW_TEE tee packet, port in m_tag 850 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 851 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 852 * args->rule contains the matching rule, 853 * args->rule.info has additional information. 854 * 855 */ 856int 857ipfw_chk(struct ip_fw_args *args) 858{ 859 860 /* 861 * Local variables holding state while processing a packet: 862 * 863 * IMPORTANT NOTE: to speed up the processing of rules, there 864 * are some assumption on the values of the variables, which 865 * are documented here. Should you change them, please check 866 * the implementation of the various instructions to make sure 867 * that they still work. 868 * 869 * args->eh The MAC header. It is non-null for a layer2 870 * packet, it is NULL for a layer-3 packet. 871 * **notyet** 872 * args->L3offset Offset in the packet to the L3 (IP or equiv.) header. 873 * 874 * m | args->m Pointer to the mbuf, as received from the caller. 875 * It may change if ipfw_chk() does an m_pullup, or if it 876 * consumes the packet because it calls send_reject(). 877 * XXX This has to change, so that ipfw_chk() never modifies 878 * or consumes the buffer. 879 * ip is the beginning of the ip(4 or 6) header. 880 * Calculated by adding the L3offset to the start of data. 881 * (Until we start using L3offset, the packet is 882 * supposed to start with the ip header). 883 */ 884 struct mbuf *m = args->m; 885 struct ip *ip = mtod(m, struct ip *); 886 887 /* 888 * For rules which contain uid/gid or jail constraints, cache 889 * a copy of the users credentials after the pcb lookup has been 890 * executed. This will speed up the processing of rules with 891 * these types of constraints, as well as decrease contention 892 * on pcb related locks. 893 */ 894#ifndef __FreeBSD__ 895 struct bsd_ucred ucred_cache; 896#else 897 struct ucred *ucred_cache = NULL; 898#endif 899 int ucred_lookup = 0; 900 901 /* 902 * oif | args->oif If NULL, ipfw_chk has been called on the 903 * inbound path (ether_input, ip_input). 904 * If non-NULL, ipfw_chk has been called on the outbound path 905 * (ether_output, ip_output). 906 */ 907 struct ifnet *oif = args->oif; 908 909 int f_pos = 0; /* index of current rule in the array */ 910 int retval = 0; 911 912 /* 913 * hlen The length of the IP header. 914 */ 915 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 916 917 /* 918 * offset The offset of a fragment. offset != 0 means that 919 * we have a fragment at this offset of an IPv4 packet. 920 * offset == 0 means that (if this is an IPv4 packet) 921 * this is the first or only fragment. 922 * For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header 923 * or there is a single packet fragement (fragement header added 924 * without needed). We will treat a single packet fragment as if 925 * there was no fragment header (or log/block depending on the 926 * V_fw_permit_single_frag6 sysctl setting). 927 */ 928 u_short offset = 0; 929 u_short ip6f_mf = 0; 930 931 /* 932 * Local copies of addresses. They are only valid if we have 933 * an IP packet. 934 * 935 * proto The protocol. Set to 0 for non-ip packets, 936 * or to the protocol read from the packet otherwise. 937 * proto != 0 means that we have an IPv4 packet. 938 * 939 * src_port, dst_port port numbers, in HOST format. Only 940 * valid for TCP and UDP packets. 941 * 942 * src_ip, dst_ip ip addresses, in NETWORK format. 943 * Only valid for IPv4 packets. 944 */ 945 uint8_t proto; 946 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 947 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 948 int iplen = 0; 949 int pktlen; 950 uint16_t etype = 0; /* Host order stored ether type */ 951 952 /* 953 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 954 * MATCH_NONE when checked and not matched (q = NULL), 955 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) 956 */ 957 int dyn_dir = MATCH_UNKNOWN; 958 ipfw_dyn_rule *q = NULL; 959 struct ip_fw_chain *chain = &V_layer3_chain; 960 961 /* 962 * We store in ulp a pointer to the upper layer protocol header. 963 * In the ipv4 case this is easy to determine from the header, 964 * but for ipv6 we might have some additional headers in the middle. 965 * ulp is NULL if not found. 966 */ 967 void *ulp = NULL; /* upper layer protocol pointer. */ 968 969 /* XXX ipv6 variables */ 970 int is_ipv6 = 0; 971 uint8_t icmp6_type = 0; 972 uint16_t ext_hd = 0; /* bits vector for extension header filtering */ 973 /* end of ipv6 variables */ 974 975 int is_ipv4 = 0; 976 977 int done = 0; /* flag to exit the outer loop */ 978 979 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready)) 980 return (IP_FW_PASS); /* accept */ 981 982 dst_ip.s_addr = 0; /* make sure it is initialized */ 983 src_ip.s_addr = 0; /* make sure it is initialized */ 984 pktlen = m->m_pkthdr.len; 985 args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */ 986 proto = args->f_id.proto = 0; /* mark f_id invalid */ 987 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ 988 989/* 990 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 991 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 992 * pointer might become stale after other pullups (but we never use it 993 * this way). 994 */ 995#define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T)) 996#define PULLUP_LEN(_len, p, T) \ 997do { \ 998 int x = (_len) + T; \ 999 if ((m)->m_len < x) { \ 1000 args->m = m = m_pullup(m, x); \ 1001 if (m == NULL) \ 1002 goto pullup_failed; \ 1003 } \ 1004 p = (mtod(m, char *) + (_len)); \ 1005} while (0) 1006 1007 /* 1008 * if we have an ether header, 1009 */ 1010 if (args->eh) 1011 etype = ntohs(args->eh->ether_type); 1012 1013 /* Identify IP packets and fill up variables. */ 1014 if (pktlen >= sizeof(struct ip6_hdr) && 1015 (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) { 1016 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 1017 is_ipv6 = 1; 1018 args->f_id.addr_type = 6; 1019 hlen = sizeof(struct ip6_hdr); 1020 proto = ip6->ip6_nxt; 1021 1022 /* Search extension headers to find upper layer protocols */ 1023 while (ulp == NULL && offset == 0) { 1024 switch (proto) { 1025 case IPPROTO_ICMPV6: 1026 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 1027 icmp6_type = ICMP6(ulp)->icmp6_type; 1028 break; 1029 1030 case IPPROTO_TCP: 1031 PULLUP_TO(hlen, ulp, struct tcphdr); 1032 dst_port = TCP(ulp)->th_dport; 1033 src_port = TCP(ulp)->th_sport; 1034 /* save flags for dynamic rules */ 1035 args->f_id._flags = TCP(ulp)->th_flags; 1036 break; 1037 1038 case IPPROTO_SCTP: 1039 PULLUP_TO(hlen, ulp, struct sctphdr); 1040 src_port = SCTP(ulp)->src_port; 1041 dst_port = SCTP(ulp)->dest_port; 1042 break; 1043 1044 case IPPROTO_UDP: 1045 PULLUP_TO(hlen, ulp, struct udphdr); 1046 dst_port = UDP(ulp)->uh_dport; 1047 src_port = UDP(ulp)->uh_sport; 1048 break; 1049 1050 case IPPROTO_HOPOPTS: /* RFC 2460 */ 1051 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1052 ext_hd |= EXT_HOPOPTS; 1053 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1054 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1055 ulp = NULL; 1056 break; 1057 1058 case IPPROTO_ROUTING: /* RFC 2460 */ 1059 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 1060 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 1061 case 0: 1062 ext_hd |= EXT_RTHDR0; 1063 break; 1064 case 2: 1065 ext_hd |= EXT_RTHDR2; 1066 break; 1067 default: 1068 if (V_fw_verbose) 1069 printf("IPFW2: IPV6 - Unknown " 1070 "Routing Header type(%d)\n", 1071 ((struct ip6_rthdr *) 1072 ulp)->ip6r_type); 1073 if (V_fw_deny_unknown_exthdrs) 1074 return (IP_FW_DENY); 1075 break; 1076 } 1077 ext_hd |= EXT_ROUTING; 1078 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 1079 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 1080 ulp = NULL; 1081 break; 1082 1083 case IPPROTO_FRAGMENT: /* RFC 2460 */ 1084 PULLUP_TO(hlen, ulp, struct ip6_frag); 1085 ext_hd |= EXT_FRAGMENT; 1086 hlen += sizeof (struct ip6_frag); 1087 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 1088 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 1089 IP6F_OFF_MASK; 1090 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg & 1091 IP6F_MORE_FRAG; 1092 if (V_fw_permit_single_frag6 == 0 && 1093 offset == 0 && ip6f_mf == 0) { 1094 if (V_fw_verbose) 1095 printf("IPFW2: IPV6 - Invalid " 1096 "Fragment Header\n"); 1097 if (V_fw_deny_unknown_exthdrs) 1098 return (IP_FW_DENY); 1099 break; 1100 } 1101 args->f_id.extra = 1102 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 1103 ulp = NULL; 1104 break; 1105 1106 case IPPROTO_DSTOPTS: /* RFC 2460 */ 1107 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1108 ext_hd |= EXT_DSTOPTS; 1109 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1110 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1111 ulp = NULL; 1112 break; 1113 1114 case IPPROTO_AH: /* RFC 2402 */ 1115 PULLUP_TO(hlen, ulp, struct ip6_ext); 1116 ext_hd |= EXT_AH; 1117 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 1118 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 1119 ulp = NULL; 1120 break; 1121 1122 case IPPROTO_ESP: /* RFC 2406 */ 1123 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 1124 /* Anything past Seq# is variable length and 1125 * data past this ext. header is encrypted. */ 1126 ext_hd |= EXT_ESP; 1127 break; 1128 1129 case IPPROTO_NONE: /* RFC 2460 */ 1130 /* 1131 * Packet ends here, and IPv6 header has 1132 * already been pulled up. If ip6e_len!=0 1133 * then octets must be ignored. 1134 */ 1135 ulp = ip; /* non-NULL to get out of loop. */ 1136 break; 1137 1138 case IPPROTO_OSPFIGP: 1139 /* XXX OSPF header check? */ 1140 PULLUP_TO(hlen, ulp, struct ip6_ext); 1141 break; 1142 1143 case IPPROTO_PIM: 1144 /* XXX PIM header check? */ 1145 PULLUP_TO(hlen, ulp, struct pim); 1146 break; 1147 1148 case IPPROTO_GRE: /* RFC 1701 */ 1149 /* XXX GRE header check? */ 1150 PULLUP_TO(hlen, ulp, struct grehdr); 1151 break; 1152 1153 case IPPROTO_CARP: 1154 PULLUP_TO(hlen, ulp, struct carp_header); 1155 if (((struct carp_header *)ulp)->carp_version != 1156 CARP_VERSION) 1157 return (IP_FW_DENY); 1158 if (((struct carp_header *)ulp)->carp_type != 1159 CARP_ADVERTISEMENT) 1160 return (IP_FW_DENY); 1161 break; 1162 1163 case IPPROTO_IPV6: /* RFC 2893 */ 1164 PULLUP_TO(hlen, ulp, struct ip6_hdr); 1165 break; 1166 1167 case IPPROTO_IPV4: /* RFC 2893 */ 1168 PULLUP_TO(hlen, ulp, struct ip); 1169 break; 1170 1171 default: 1172 if (V_fw_verbose) 1173 printf("IPFW2: IPV6 - Unknown " 1174 "Extension Header(%d), ext_hd=%x\n", 1175 proto, ext_hd); 1176 if (V_fw_deny_unknown_exthdrs) 1177 return (IP_FW_DENY); 1178 PULLUP_TO(hlen, ulp, struct ip6_ext); 1179 break; 1180 } /*switch */ 1181 } 1182 ip = mtod(m, struct ip *); 1183 ip6 = (struct ip6_hdr *)ip; 1184 args->f_id.src_ip6 = ip6->ip6_src; 1185 args->f_id.dst_ip6 = ip6->ip6_dst; 1186 args->f_id.src_ip = 0; 1187 args->f_id.dst_ip = 0; 1188 args->f_id.flow_id6 = ntohl(ip6->ip6_flow); 1189 iplen = ntohs(ip6->ip6_plen) + sizeof(*ip6); 1190 } else if (pktlen >= sizeof(struct ip) && 1191 (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) { 1192 is_ipv4 = 1; 1193 hlen = ip->ip_hl << 2; 1194 args->f_id.addr_type = 4; 1195 1196 /* 1197 * Collect parameters into local variables for faster matching. 1198 */ 1199 proto = ip->ip_p; 1200 src_ip = ip->ip_src; 1201 dst_ip = ip->ip_dst; 1202 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1203 iplen = ntohs(ip->ip_len); 1204 1205 if (offset == 0) { 1206 switch (proto) { 1207 case IPPROTO_TCP: 1208 PULLUP_TO(hlen, ulp, struct tcphdr); 1209 dst_port = TCP(ulp)->th_dport; 1210 src_port = TCP(ulp)->th_sport; 1211 /* save flags for dynamic rules */ 1212 args->f_id._flags = TCP(ulp)->th_flags; 1213 break; 1214 1215 case IPPROTO_SCTP: 1216 PULLUP_TO(hlen, ulp, struct sctphdr); 1217 src_port = SCTP(ulp)->src_port; 1218 dst_port = SCTP(ulp)->dest_port; 1219 break; 1220 1221 case IPPROTO_UDP: 1222 PULLUP_TO(hlen, ulp, struct udphdr); 1223 dst_port = UDP(ulp)->uh_dport; 1224 src_port = UDP(ulp)->uh_sport; 1225 break; 1226 1227 case IPPROTO_ICMP: 1228 PULLUP_TO(hlen, ulp, struct icmphdr); 1229 //args->f_id.flags = ICMP(ulp)->icmp_type; 1230 break; 1231 1232 default: 1233 break; 1234 } 1235 } 1236 1237 ip = mtod(m, struct ip *); 1238 args->f_id.src_ip = ntohl(src_ip.s_addr); 1239 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1240 } 1241#undef PULLUP_TO 1242 pktlen = iplen < pktlen ? iplen: pktlen; 1243 if (proto) { /* we may have port numbers, store them */ 1244 args->f_id.proto = proto; 1245 args->f_id.src_port = src_port = ntohs(src_port); 1246 args->f_id.dst_port = dst_port = ntohs(dst_port); 1247 } 1248 1249 IPFW_PF_RLOCK(chain); 1250 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ 1251 IPFW_PF_RUNLOCK(chain); 1252 return (IP_FW_PASS); /* accept */ 1253 } 1254 if (args->rule.slot) { 1255 /* 1256 * Packet has already been tagged as a result of a previous 1257 * match on rule args->rule aka args->rule_id (PIPE, QUEUE, 1258 * REASS, NETGRAPH, DIVERT/TEE...) 1259 * Validate the slot and continue from the next one 1260 * if still present, otherwise do a lookup. 1261 */ 1262 f_pos = (args->rule.chain_id == chain->id) ? 1263 args->rule.slot : 1264 ipfw_find_rule(chain, args->rule.rulenum, 1265 args->rule.rule_id); 1266 } else { 1267 f_pos = 0; 1268 } 1269 1270 /* 1271 * Now scan the rules, and parse microinstructions for each rule. 1272 * We have two nested loops and an inner switch. Sometimes we 1273 * need to break out of one or both loops, or re-enter one of 1274 * the loops with updated variables. Loop variables are: 1275 * 1276 * f_pos (outer loop) points to the current rule. 1277 * On output it points to the matching rule. 1278 * done (outer loop) is used as a flag to break the loop. 1279 * l (inner loop) residual length of current rule. 1280 * cmd points to the current microinstruction. 1281 * 1282 * We break the inner loop by setting l=0 and possibly 1283 * cmdlen=0 if we don't want to advance cmd. 1284 * We break the outer loop by setting done=1 1285 * We can restart the inner loop by setting l>0 and f_pos, f, cmd 1286 * as needed. 1287 */ 1288 for (; f_pos < chain->n_rules; f_pos++) { 1289 ipfw_insn *cmd; 1290 uint32_t tablearg = 0; 1291 int l, cmdlen, skip_or; /* skip rest of OR block */ 1292 struct ip_fw *f; 1293 1294 f = chain->map[f_pos]; 1295 if (V_set_disable & (1 << f->set) ) 1296 continue; 1297 1298 skip_or = 0; 1299 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 1300 l -= cmdlen, cmd += cmdlen) { 1301 int match; 1302 1303 /* 1304 * check_body is a jump target used when we find a 1305 * CHECK_STATE, and need to jump to the body of 1306 * the target rule. 1307 */ 1308 1309/* check_body: */ 1310 cmdlen = F_LEN(cmd); 1311 /* 1312 * An OR block (insn_1 || .. || insn_n) has the 1313 * F_OR bit set in all but the last instruction. 1314 * The first match will set "skip_or", and cause 1315 * the following instructions to be skipped until 1316 * past the one with the F_OR bit clear. 1317 */ 1318 if (skip_or) { /* skip this instruction */ 1319 if ((cmd->len & F_OR) == 0) 1320 skip_or = 0; /* next one is good */ 1321 continue; 1322 } 1323 match = 0; /* set to 1 if we succeed */ 1324 1325 switch (cmd->opcode) { 1326 /* 1327 * The first set of opcodes compares the packet's 1328 * fields with some pattern, setting 'match' if a 1329 * match is found. At the end of the loop there is 1330 * logic to deal with F_NOT and F_OR flags associated 1331 * with the opcode. 1332 */ 1333 case O_NOP: 1334 match = 1; 1335 break; 1336 1337 case O_FORWARD_MAC: 1338 printf("ipfw: opcode %d unimplemented\n", 1339 cmd->opcode); 1340 break; 1341 1342 case O_GID: 1343 case O_UID: 1344 case O_JAIL: 1345 /* 1346 * We only check offset == 0 && proto != 0, 1347 * as this ensures that we have a 1348 * packet with the ports info. 1349 */ 1350 if (offset != 0) 1351 break; 1352 if (proto == IPPROTO_TCP || 1353 proto == IPPROTO_UDP) 1354 match = check_uidgid( 1355 (ipfw_insn_u32 *)cmd, 1356 args, &ucred_lookup, 1357#ifdef __FreeBSD__ 1358 &ucred_cache); 1359#else 1360 (void *)&ucred_cache); 1361#endif 1362 break; 1363 1364 case O_RECV: 1365 match = iface_match(m->m_pkthdr.rcvif, 1366 (ipfw_insn_if *)cmd, chain, &tablearg); 1367 break; 1368 1369 case O_XMIT: 1370 match = iface_match(oif, (ipfw_insn_if *)cmd, 1371 chain, &tablearg); 1372 break; 1373 1374 case O_VIA: 1375 match = iface_match(oif ? oif : 1376 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd, 1377 chain, &tablearg); 1378 break; 1379 1380 case O_MACADDR2: 1381 if (args->eh != NULL) { /* have MAC header */ 1382 u_int32_t *want = (u_int32_t *) 1383 ((ipfw_insn_mac *)cmd)->addr; 1384 u_int32_t *mask = (u_int32_t *) 1385 ((ipfw_insn_mac *)cmd)->mask; 1386 u_int32_t *hdr = (u_int32_t *)args->eh; 1387 1388 match = 1389 ( want[0] == (hdr[0] & mask[0]) && 1390 want[1] == (hdr[1] & mask[1]) && 1391 want[2] == (hdr[2] & mask[2]) ); 1392 } 1393 break; 1394 1395 case O_MAC_TYPE: 1396 if (args->eh != NULL) { 1397 u_int16_t *p = 1398 ((ipfw_insn_u16 *)cmd)->ports; 1399 int i; 1400 1401 for (i = cmdlen - 1; !match && i>0; 1402 i--, p += 2) 1403 match = (etype >= p[0] && 1404 etype <= p[1]); 1405 } 1406 break; 1407 1408 case O_FRAG: 1409 match = (offset != 0); 1410 break; 1411 1412 case O_IN: /* "out" is "not in" */ 1413 match = (oif == NULL); 1414 break; 1415 1416 case O_LAYER2: 1417 match = (args->eh != NULL); 1418 break; 1419 1420 case O_DIVERTED: 1421 { 1422 /* For diverted packets, args->rule.info 1423 * contains the divert port (in host format) 1424 * reason and direction. 1425 */ 1426 uint32_t i = args->rule.info; 1427 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT && 1428 cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2); 1429 } 1430 break; 1431 1432 case O_PROTO: 1433 /* 1434 * We do not allow an arg of 0 so the 1435 * check of "proto" only suffices. 1436 */ 1437 match = (proto == cmd->arg1); 1438 break; 1439 1440 case O_IP_SRC: 1441 match = is_ipv4 && 1442 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1443 src_ip.s_addr); 1444 break; 1445 1446 case O_IP_SRC_LOOKUP: 1447 case O_IP_DST_LOOKUP: 1448 if (is_ipv4) { 1449 uint32_t key = 1450 (cmd->opcode == O_IP_DST_LOOKUP) ? 1451 dst_ip.s_addr : src_ip.s_addr; 1452 uint32_t v = 0; 1453 1454 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { 1455 /* generic lookup. The key must be 1456 * in 32bit big-endian format. 1457 */ 1458 v = ((ipfw_insn_u32 *)cmd)->d[1]; 1459 if (v == 0) 1460 key = dst_ip.s_addr; 1461 else if (v == 1) 1462 key = src_ip.s_addr; 1463 else if (v == 6) /* dscp */ 1464 key = (ip->ip_tos >> 2) & 0x3f; 1465 else if (offset != 0) 1466 break; 1467 else if (proto != IPPROTO_TCP && 1468 proto != IPPROTO_UDP) 1469 break; 1470 else if (v == 2) 1471 key = htonl(dst_port); 1472 else if (v == 3) 1473 key = htonl(src_port); 1474 else if (v == 4 || v == 5) { 1475 check_uidgid( 1476 (ipfw_insn_u32 *)cmd, 1477 args, &ucred_lookup, 1478#ifdef __FreeBSD__ 1479 &ucred_cache); 1480 if (v == 4 /* O_UID */) 1481 key = ucred_cache->cr_uid; 1482 else if (v == 5 /* O_JAIL */) 1483 key = ucred_cache->cr_prison->pr_id; 1484#else /* !__FreeBSD__ */ 1485 (void *)&ucred_cache); 1486 if (v ==4 /* O_UID */) 1487 key = ucred_cache.uid; 1488 else if (v == 5 /* O_JAIL */) 1489 key = ucred_cache.xid; 1490#endif /* !__FreeBSD__ */ 1491 key = htonl(key); 1492 } else 1493 break; 1494 } 1495 match = ipfw_lookup_table(chain, 1496 cmd->arg1, key, &v); 1497 if (!match) 1498 break; 1499 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1500 match = 1501 ((ipfw_insn_u32 *)cmd)->d[0] == v; 1502 else 1503 tablearg = v; 1504 } else if (is_ipv6) { 1505 uint32_t v = 0; 1506 void *pkey = (cmd->opcode == O_IP_DST_LOOKUP) ? 1507 &args->f_id.dst_ip6: &args->f_id.src_ip6; 1508 match = ipfw_lookup_table_extended(chain, 1509 cmd->arg1, pkey, &v, 1510 IPFW_TABLE_CIDR); 1511 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1512 match = ((ipfw_insn_u32 *)cmd)->d[0] == v; 1513 if (match) 1514 tablearg = v; 1515 } 1516 break; 1517 1518 case O_IP_SRC_MASK: 1519 case O_IP_DST_MASK: 1520 if (is_ipv4) { 1521 uint32_t a = 1522 (cmd->opcode == O_IP_DST_MASK) ? 1523 dst_ip.s_addr : src_ip.s_addr; 1524 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 1525 int i = cmdlen-1; 1526 1527 for (; !match && i>0; i-= 2, p+= 2) 1528 match = (p[0] == (a & p[1])); 1529 } 1530 break; 1531 1532 case O_IP_SRC_ME: 1533 if (is_ipv4) { 1534 struct ifnet *tif; 1535 1536 INADDR_TO_IFP(src_ip, tif); 1537 match = (tif != NULL); 1538 break; 1539 } 1540#ifdef INET6 1541 /* FALLTHROUGH */ 1542 case O_IP6_SRC_ME: 1543 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6); 1544#endif 1545 break; 1546 1547 case O_IP_DST_SET: 1548 case O_IP_SRC_SET: 1549 if (is_ipv4) { 1550 u_int32_t *d = (u_int32_t *)(cmd+1); 1551 u_int32_t addr = 1552 cmd->opcode == O_IP_DST_SET ? 1553 args->f_id.dst_ip : 1554 args->f_id.src_ip; 1555 1556 if (addr < d[0]) 1557 break; 1558 addr -= d[0]; /* subtract base */ 1559 match = (addr < cmd->arg1) && 1560 ( d[ 1 + (addr>>5)] & 1561 (1<<(addr & 0x1f)) ); 1562 } 1563 break; 1564 1565 case O_IP_DST: 1566 match = is_ipv4 && 1567 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1568 dst_ip.s_addr); 1569 break; 1570 1571 case O_IP_DST_ME: 1572 if (is_ipv4) { 1573 struct ifnet *tif; 1574 1575 INADDR_TO_IFP(dst_ip, tif); 1576 match = (tif != NULL); 1577 break; 1578 } 1579#ifdef INET6 1580 /* FALLTHROUGH */ 1581 case O_IP6_DST_ME: 1582 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6); 1583#endif 1584 break; 1585 1586 1587 case O_IP_SRCPORT: 1588 case O_IP_DSTPORT: 1589 /* 1590 * offset == 0 && proto != 0 is enough 1591 * to guarantee that we have a 1592 * packet with port info. 1593 */ 1594 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP) 1595 && offset == 0) { 1596 u_int16_t x = 1597 (cmd->opcode == O_IP_SRCPORT) ? 1598 src_port : dst_port ; 1599 u_int16_t *p = 1600 ((ipfw_insn_u16 *)cmd)->ports; 1601 int i; 1602 1603 for (i = cmdlen - 1; !match && i>0; 1604 i--, p += 2) 1605 match = (x>=p[0] && x<=p[1]); 1606 } 1607 break; 1608 1609 case O_ICMPTYPE: 1610 match = (offset == 0 && proto==IPPROTO_ICMP && 1611 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 1612 break; 1613 1614#ifdef INET6 1615 case O_ICMP6TYPE: 1616 match = is_ipv6 && offset == 0 && 1617 proto==IPPROTO_ICMPV6 && 1618 icmp6type_match( 1619 ICMP6(ulp)->icmp6_type, 1620 (ipfw_insn_u32 *)cmd); 1621 break; 1622#endif /* INET6 */ 1623 1624 case O_IPOPT: 1625 match = (is_ipv4 && 1626 ipopts_match(ip, cmd) ); 1627 break; 1628 1629 case O_IPVER: 1630 match = (is_ipv4 && 1631 cmd->arg1 == ip->ip_v); 1632 break; 1633 1634 case O_IPID: 1635 case O_IPLEN: 1636 case O_IPTTL: 1637 if (is_ipv4) { /* only for IP packets */ 1638 uint16_t x; 1639 uint16_t *p; 1640 int i; 1641 1642 if (cmd->opcode == O_IPLEN) 1643 x = iplen; 1644 else if (cmd->opcode == O_IPTTL) 1645 x = ip->ip_ttl; 1646 else /* must be IPID */ 1647 x = ntohs(ip->ip_id); 1648 if (cmdlen == 1) { 1649 match = (cmd->arg1 == x); 1650 break; 1651 } 1652 /* otherwise we have ranges */ 1653 p = ((ipfw_insn_u16 *)cmd)->ports; 1654 i = cmdlen - 1; 1655 for (; !match && i>0; i--, p += 2) 1656 match = (x >= p[0] && x <= p[1]); 1657 } 1658 break; 1659 1660 case O_IPPRECEDENCE: 1661 match = (is_ipv4 && 1662 (cmd->arg1 == (ip->ip_tos & 0xe0)) ); 1663 break; 1664 1665 case O_IPTOS: 1666 match = (is_ipv4 && 1667 flags_match(cmd, ip->ip_tos)); 1668 break; 1669 1670 case O_DSCP: 1671 { 1672 uint32_t *p; 1673 uint16_t x; 1674 1675 p = ((ipfw_insn_u32 *)cmd)->d; 1676 1677 if (is_ipv4) 1678 x = ip->ip_tos >> 2; 1679 else if (is_ipv6) { 1680 uint8_t *v; 1681 v = &((struct ip6_hdr *)ip)->ip6_vfc; 1682 x = (*v & 0x0F) << 2; 1683 v++; 1684 x |= *v >> 6; 1685 } else 1686 break; 1687 1688 /* DSCP bitmask is stored as low_u32 high_u32 */ 1689 if (x >= 32) 1690 match = *(p + 1) & (1 << (x - 32)); 1691 else 1692 match = *p & (1 << x); 1693 } 1694 break; 1695 1696 case O_TCPDATALEN: 1697 if (proto == IPPROTO_TCP && offset == 0) { 1698 struct tcphdr *tcp; 1699 uint16_t x; 1700 uint16_t *p; 1701 int i; 1702#ifdef INET6 1703 if (is_ipv6) { 1704 struct ip6_hdr *ip6; 1705 1706 ip6 = (struct ip6_hdr *)ip; 1707 if (ip6->ip6_plen == 0) { 1708 /* 1709 * Jumbo payload is not 1710 * supported by this 1711 * opcode. 1712 */ 1713 break; 1714 } 1715 x = iplen - hlen; 1716 } else 1717#endif /* INET6 */ 1718 x = iplen - (ip->ip_hl << 2); 1719 tcp = TCP(ulp); 1720 x -= tcp->th_off << 2; 1721 if (cmdlen == 1) { 1722 match = (cmd->arg1 == x); 1723 break; 1724 } 1725 /* otherwise we have ranges */ 1726 p = ((ipfw_insn_u16 *)cmd)->ports; 1727 i = cmdlen - 1; 1728 for (; !match && i>0; i--, p += 2) 1729 match = (x >= p[0] && x <= p[1]); 1730 } 1731 break; 1732 1733 case O_TCPFLAGS: 1734 match = (proto == IPPROTO_TCP && offset == 0 && 1735 flags_match(cmd, TCP(ulp)->th_flags)); 1736 break; 1737 1738 case O_TCPOPTS: 1739 PULLUP_LEN(hlen, ulp, (TCP(ulp)->th_off << 2)); 1740 match = (proto == IPPROTO_TCP && offset == 0 && 1741 tcpopts_match(TCP(ulp), cmd)); 1742 break; 1743 1744 case O_TCPSEQ: 1745 match = (proto == IPPROTO_TCP && offset == 0 && 1746 ((ipfw_insn_u32 *)cmd)->d[0] == 1747 TCP(ulp)->th_seq); 1748 break; 1749 1750 case O_TCPACK: 1751 match = (proto == IPPROTO_TCP && offset == 0 && 1752 ((ipfw_insn_u32 *)cmd)->d[0] == 1753 TCP(ulp)->th_ack); 1754 break; 1755 1756 case O_TCPWIN: 1757 if (proto == IPPROTO_TCP && offset == 0) { 1758 uint16_t x; 1759 uint16_t *p; 1760 int i; 1761 1762 x = ntohs(TCP(ulp)->th_win); 1763 if (cmdlen == 1) { 1764 match = (cmd->arg1 == x); 1765 break; 1766 } 1767 /* Otherwise we have ranges. */ 1768 p = ((ipfw_insn_u16 *)cmd)->ports; 1769 i = cmdlen - 1; 1770 for (; !match && i > 0; i--, p += 2) 1771 match = (x >= p[0] && x <= p[1]); 1772 } 1773 break; 1774 1775 case O_ESTAB: 1776 /* reject packets which have SYN only */ 1777 /* XXX should i also check for TH_ACK ? */ 1778 match = (proto == IPPROTO_TCP && offset == 0 && 1779 (TCP(ulp)->th_flags & 1780 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 1781 break; 1782 1783 case O_ALTQ: { 1784 struct pf_mtag *at; 1785 struct m_tag *mtag; 1786 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 1787 1788 /* 1789 * ALTQ uses mbuf tags from another 1790 * packet filtering system - pf(4). 1791 * We allocate a tag in its format 1792 * and fill it in, pretending to be pf(4). 1793 */ 1794 match = 1; 1795 at = pf_find_mtag(m); 1796 if (at != NULL && at->qid != 0) 1797 break; 1798 mtag = m_tag_get(PACKET_TAG_PF, 1799 sizeof(struct pf_mtag), M_NOWAIT | M_ZERO); 1800 if (mtag == NULL) { 1801 /* 1802 * Let the packet fall back to the 1803 * default ALTQ. 1804 */ 1805 break; 1806 } 1807 m_tag_prepend(m, mtag); 1808 at = (struct pf_mtag *)(mtag + 1); 1809 at->qid = altq->qid; 1810 at->hdr = ip; 1811 break; 1812 } 1813 1814 case O_LOG: 1815 ipfw_log(f, hlen, args, m, 1816 oif, offset | ip6f_mf, tablearg, ip); 1817 match = 1; 1818 break; 1819 1820 case O_PROB: 1821 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 1822 break; 1823 1824 case O_VERREVPATH: 1825 /* Outgoing packets automatically pass/match */ 1826 match = ((oif != NULL) || 1827 (m->m_pkthdr.rcvif == NULL) || 1828 ( 1829#ifdef INET6 1830 is_ipv6 ? 1831 verify_path6(&(args->f_id.src_ip6), 1832 m->m_pkthdr.rcvif, args->f_id.fib) : 1833#endif 1834 verify_path(src_ip, m->m_pkthdr.rcvif, 1835 args->f_id.fib))); 1836 break; 1837 1838 case O_VERSRCREACH: 1839 /* Outgoing packets automatically pass/match */ 1840 match = (hlen > 0 && ((oif != NULL) || 1841#ifdef INET6 1842 is_ipv6 ? 1843 verify_path6(&(args->f_id.src_ip6), 1844 NULL, args->f_id.fib) : 1845#endif 1846 verify_path(src_ip, NULL, args->f_id.fib))); 1847 break; 1848 1849 case O_ANTISPOOF: 1850 /* Outgoing packets automatically pass/match */ 1851 if (oif == NULL && hlen > 0 && 1852 ( (is_ipv4 && in_localaddr(src_ip)) 1853#ifdef INET6 1854 || (is_ipv6 && 1855 in6_localaddr(&(args->f_id.src_ip6))) 1856#endif 1857 )) 1858 match = 1859#ifdef INET6 1860 is_ipv6 ? verify_path6( 1861 &(args->f_id.src_ip6), 1862 m->m_pkthdr.rcvif, 1863 args->f_id.fib) : 1864#endif 1865 verify_path(src_ip, 1866 m->m_pkthdr.rcvif, 1867 args->f_id.fib); 1868 else 1869 match = 1; 1870 break; 1871 1872 case O_IPSEC: 1873#ifdef IPSEC 1874 match = (m_tag_find(m, 1875 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 1876#endif 1877 /* otherwise no match */ 1878 break; 1879 1880#ifdef INET6 1881 case O_IP6_SRC: 1882 match = is_ipv6 && 1883 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 1884 &((ipfw_insn_ip6 *)cmd)->addr6); 1885 break; 1886 1887 case O_IP6_DST: 1888 match = is_ipv6 && 1889 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 1890 &((ipfw_insn_ip6 *)cmd)->addr6); 1891 break; 1892 case O_IP6_SRC_MASK: 1893 case O_IP6_DST_MASK: 1894 if (is_ipv6) { 1895 int i = cmdlen - 1; 1896 struct in6_addr p; 1897 struct in6_addr *d = 1898 &((ipfw_insn_ip6 *)cmd)->addr6; 1899 1900 for (; !match && i > 0; d += 2, 1901 i -= F_INSN_SIZE(struct in6_addr) 1902 * 2) { 1903 p = (cmd->opcode == 1904 O_IP6_SRC_MASK) ? 1905 args->f_id.src_ip6: 1906 args->f_id.dst_ip6; 1907 APPLY_MASK(&p, &d[1]); 1908 match = 1909 IN6_ARE_ADDR_EQUAL(&d[0], 1910 &p); 1911 } 1912 } 1913 break; 1914 1915 case O_FLOW6ID: 1916 match = is_ipv6 && 1917 flow6id_match(args->f_id.flow_id6, 1918 (ipfw_insn_u32 *) cmd); 1919 break; 1920 1921 case O_EXT_HDR: 1922 match = is_ipv6 && 1923 (ext_hd & ((ipfw_insn *) cmd)->arg1); 1924 break; 1925 1926 case O_IP6: 1927 match = is_ipv6; 1928 break; 1929#endif 1930 1931 case O_IP4: 1932 match = is_ipv4; 1933 break; 1934 1935 case O_TAG: { 1936 struct m_tag *mtag; 1937 uint32_t tag = IP_FW_ARG_TABLEARG(cmd->arg1); 1938 1939 /* Packet is already tagged with this tag? */ 1940 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 1941 1942 /* We have `untag' action when F_NOT flag is 1943 * present. And we must remove this mtag from 1944 * mbuf and reset `match' to zero (`match' will 1945 * be inversed later). 1946 * Otherwise we should allocate new mtag and 1947 * push it into mbuf. 1948 */ 1949 if (cmd->len & F_NOT) { /* `untag' action */ 1950 if (mtag != NULL) 1951 m_tag_delete(m, mtag); 1952 match = 0; 1953 } else { 1954 if (mtag == NULL) { 1955 mtag = m_tag_alloc( MTAG_IPFW, 1956 tag, 0, M_NOWAIT); 1957 if (mtag != NULL) 1958 m_tag_prepend(m, mtag); 1959 } 1960 match = 1; 1961 } 1962 break; 1963 } 1964 1965 case O_FIB: /* try match the specified fib */ 1966 if (args->f_id.fib == cmd->arg1) 1967 match = 1; 1968 break; 1969 1970 case O_SOCKARG: { 1971 struct inpcb *inp = args->inp; 1972 struct inpcbinfo *pi; 1973 1974 if (is_ipv6) /* XXX can we remove this ? */ 1975 break; 1976 1977 if (proto == IPPROTO_TCP) 1978 pi = &V_tcbinfo; 1979 else if (proto == IPPROTO_UDP) 1980 pi = &V_udbinfo; 1981 else 1982 break; 1983 1984 /* 1985 * XXXRW: so_user_cookie should almost 1986 * certainly be inp_user_cookie? 1987 */ 1988 1989 /* For incomming packet, lookup up the 1990 inpcb using the src/dest ip/port tuple */ 1991 if (inp == NULL) { 1992 inp = in_pcblookup(pi, 1993 src_ip, htons(src_port), 1994 dst_ip, htons(dst_port), 1995 INPLOOKUP_RLOCKPCB, NULL); 1996 if (inp != NULL) { 1997 tablearg = 1998 inp->inp_socket->so_user_cookie; 1999 if (tablearg) 2000 match = 1; 2001 INP_RUNLOCK(inp); 2002 } 2003 } else { 2004 if (inp->inp_socket) { 2005 tablearg = 2006 inp->inp_socket->so_user_cookie; 2007 if (tablearg) 2008 match = 1; 2009 } 2010 } 2011 break; 2012 } 2013 2014 case O_TAGGED: { 2015 struct m_tag *mtag; 2016 uint32_t tag = IP_FW_ARG_TABLEARG(cmd->arg1); 2017 2018 if (cmdlen == 1) { 2019 match = m_tag_locate(m, MTAG_IPFW, 2020 tag, NULL) != NULL; 2021 break; 2022 } 2023 2024 /* we have ranges */ 2025 for (mtag = m_tag_first(m); 2026 mtag != NULL && !match; 2027 mtag = m_tag_next(m, mtag)) { 2028 uint16_t *p; 2029 int i; 2030 2031 if (mtag->m_tag_cookie != MTAG_IPFW) 2032 continue; 2033 2034 p = ((ipfw_insn_u16 *)cmd)->ports; 2035 i = cmdlen - 1; 2036 for(; !match && i > 0; i--, p += 2) 2037 match = 2038 mtag->m_tag_id >= p[0] && 2039 mtag->m_tag_id <= p[1]; 2040 } 2041 break; 2042 } 2043 2044 /* 2045 * The second set of opcodes represents 'actions', 2046 * i.e. the terminal part of a rule once the packet 2047 * matches all previous patterns. 2048 * Typically there is only one action for each rule, 2049 * and the opcode is stored at the end of the rule 2050 * (but there are exceptions -- see below). 2051 * 2052 * In general, here we set retval and terminate the 2053 * outer loop (would be a 'break 3' in some language, 2054 * but we need to set l=0, done=1) 2055 * 2056 * Exceptions: 2057 * O_COUNT and O_SKIPTO actions: 2058 * instead of terminating, we jump to the next rule 2059 * (setting l=0), or to the SKIPTO target (setting 2060 * f/f_len, cmd and l as needed), respectively. 2061 * 2062 * O_TAG, O_LOG and O_ALTQ action parameters: 2063 * perform some action and set match = 1; 2064 * 2065 * O_LIMIT and O_KEEP_STATE: these opcodes are 2066 * not real 'actions', and are stored right 2067 * before the 'action' part of the rule. 2068 * These opcodes try to install an entry in the 2069 * state tables; if successful, we continue with 2070 * the next opcode (match=1; break;), otherwise 2071 * the packet must be dropped (set retval, 2072 * break loops with l=0, done=1) 2073 * 2074 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2075 * cause a lookup of the state table, and a jump 2076 * to the 'action' part of the parent rule 2077 * if an entry is found, or 2078 * (CHECK_STATE only) a jump to the next rule if 2079 * the entry is not found. 2080 * The result of the lookup is cached so that 2081 * further instances of these opcodes become NOPs. 2082 * The jump to the next rule is done by setting 2083 * l=0, cmdlen=0. 2084 */ 2085 case O_LIMIT: 2086 case O_KEEP_STATE: 2087 if (ipfw_install_state(f, 2088 (ipfw_insn_limit *)cmd, args, tablearg)) { 2089 /* error or limit violation */ 2090 retval = IP_FW_DENY; 2091 l = 0; /* exit inner loop */ 2092 done = 1; /* exit outer loop */ 2093 } 2094 match = 1; 2095 break; 2096 2097 case O_PROBE_STATE: 2098 case O_CHECK_STATE: 2099 /* 2100 * dynamic rules are checked at the first 2101 * keep-state or check-state occurrence, 2102 * with the result being stored in dyn_dir. 2103 * The compiler introduces a PROBE_STATE 2104 * instruction for us when we have a 2105 * KEEP_STATE (because PROBE_STATE needs 2106 * to be run first). 2107 */ 2108 if (dyn_dir == MATCH_UNKNOWN && 2109 (q = ipfw_lookup_dyn_rule(&args->f_id, 2110 &dyn_dir, proto == IPPROTO_TCP ? 2111 TCP(ulp) : NULL)) 2112 != NULL) { 2113 /* 2114 * Found dynamic entry, update stats 2115 * and jump to the 'action' part of 2116 * the parent rule by setting 2117 * f, cmd, l and clearing cmdlen. 2118 */ 2119 IPFW_INC_DYN_COUNTER(q, pktlen); 2120 /* XXX we would like to have f_pos 2121 * readily accessible in the dynamic 2122 * rule, instead of having to 2123 * lookup q->rule. 2124 */ 2125 f = q->rule; 2126 f_pos = ipfw_find_rule(chain, 2127 f->rulenum, f->id); 2128 cmd = ACTION_PTR(f); 2129 l = f->cmd_len - f->act_ofs; 2130 ipfw_dyn_unlock(q); 2131 cmdlen = 0; 2132 match = 1; 2133 break; 2134 } 2135 /* 2136 * Dynamic entry not found. If CHECK_STATE, 2137 * skip to next rule, if PROBE_STATE just 2138 * ignore and continue with next opcode. 2139 */ 2140 if (cmd->opcode == O_CHECK_STATE) 2141 l = 0; /* exit inner loop */ 2142 match = 1; 2143 break; 2144 2145 case O_ACCEPT: 2146 retval = 0; /* accept */ 2147 l = 0; /* exit inner loop */ 2148 done = 1; /* exit outer loop */ 2149 break; 2150 2151 case O_PIPE: 2152 case O_QUEUE: 2153 set_match(args, f_pos, chain); 2154 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1); 2155 if (cmd->opcode == O_PIPE) 2156 args->rule.info |= IPFW_IS_PIPE; 2157 if (V_fw_one_pass) 2158 args->rule.info |= IPFW_ONEPASS; 2159 retval = IP_FW_DUMMYNET; 2160 l = 0; /* exit inner loop */ 2161 done = 1; /* exit outer loop */ 2162 break; 2163 2164 case O_DIVERT: 2165 case O_TEE: 2166 if (args->eh) /* not on layer 2 */ 2167 break; 2168 /* otherwise this is terminal */ 2169 l = 0; /* exit inner loop */ 2170 done = 1; /* exit outer loop */ 2171 retval = (cmd->opcode == O_DIVERT) ? 2172 IP_FW_DIVERT : IP_FW_TEE; 2173 set_match(args, f_pos, chain); 2174 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1); 2175 break; 2176 2177 case O_COUNT: 2178 IPFW_INC_RULE_COUNTER(f, pktlen); 2179 l = 0; /* exit inner loop */ 2180 break; 2181 2182 case O_SKIPTO: 2183 IPFW_INC_RULE_COUNTER(f, pktlen); 2184 f_pos = jump_fast(chain, f, cmd->arg1, tablearg, 0); 2185 /* 2186 * Skip disabled rules, and re-enter 2187 * the inner loop with the correct 2188 * f_pos, f, l and cmd. 2189 * Also clear cmdlen and skip_or 2190 */ 2191 for (; f_pos < chain->n_rules - 1 && 2192 (V_set_disable & 2193 (1 << chain->map[f_pos]->set)); 2194 f_pos++) 2195 ; 2196 /* Re-enter the inner loop at the skipto rule. */ 2197 f = chain->map[f_pos]; 2198 l = f->cmd_len; 2199 cmd = f->cmd; 2200 match = 1; 2201 cmdlen = 0; 2202 skip_or = 0; 2203 continue; 2204 break; /* not reached */ 2205 2206 case O_CALLRETURN: { 2207 /* 2208 * Implementation of `subroutine' call/return, 2209 * in the stack carried in an mbuf tag. This 2210 * is different from `skipto' in that any call 2211 * address is possible (`skipto' must prevent 2212 * backward jumps to avoid endless loops). 2213 * We have `return' action when F_NOT flag is 2214 * present. The `m_tag_id' field is used as 2215 * stack pointer. 2216 */ 2217 struct m_tag *mtag; 2218 uint16_t jmpto, *stack; 2219 2220#define IS_CALL ((cmd->len & F_NOT) == 0) 2221#define IS_RETURN ((cmd->len & F_NOT) != 0) 2222 /* 2223 * Hand-rolled version of m_tag_locate() with 2224 * wildcard `type'. 2225 * If not already tagged, allocate new tag. 2226 */ 2227 mtag = m_tag_first(m); 2228 while (mtag != NULL) { 2229 if (mtag->m_tag_cookie == 2230 MTAG_IPFW_CALL) 2231 break; 2232 mtag = m_tag_next(m, mtag); 2233 } 2234 if (mtag == NULL && IS_CALL) { 2235 mtag = m_tag_alloc(MTAG_IPFW_CALL, 0, 2236 IPFW_CALLSTACK_SIZE * 2237 sizeof(uint16_t), M_NOWAIT); 2238 if (mtag != NULL) 2239 m_tag_prepend(m, mtag); 2240 } 2241 2242 /* 2243 * On error both `call' and `return' just 2244 * continue with next rule. 2245 */ 2246 if (IS_RETURN && (mtag == NULL || 2247 mtag->m_tag_id == 0)) { 2248 l = 0; /* exit inner loop */ 2249 break; 2250 } 2251 if (IS_CALL && (mtag == NULL || 2252 mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) { 2253 printf("ipfw: call stack error, " 2254 "go to next rule\n"); 2255 l = 0; /* exit inner loop */ 2256 break; 2257 } 2258 2259 IPFW_INC_RULE_COUNTER(f, pktlen); 2260 stack = (uint16_t *)(mtag + 1); 2261 2262 /* 2263 * The `call' action may use cached f_pos 2264 * (in f->next_rule), whose version is written 2265 * in f->next_rule. 2266 * The `return' action, however, doesn't have 2267 * fixed jump address in cmd->arg1 and can't use 2268 * cache. 2269 */ 2270 if (IS_CALL) { 2271 stack[mtag->m_tag_id] = f->rulenum; 2272 mtag->m_tag_id++; 2273 f_pos = jump_fast(chain, f, cmd->arg1, 2274 tablearg, 1); 2275 } else { /* `return' action */ 2276 mtag->m_tag_id--; 2277 jmpto = stack[mtag->m_tag_id] + 1; 2278 f_pos = ipfw_find_rule(chain, jmpto, 0); 2279 } 2280 2281 /* 2282 * Skip disabled rules, and re-enter 2283 * the inner loop with the correct 2284 * f_pos, f, l and cmd. 2285 * Also clear cmdlen and skip_or 2286 */ 2287 for (; f_pos < chain->n_rules - 1 && 2288 (V_set_disable & 2289 (1 << chain->map[f_pos]->set)); f_pos++) 2290 ; 2291 /* Re-enter the inner loop at the dest rule. */ 2292 f = chain->map[f_pos]; 2293 l = f->cmd_len; 2294 cmd = f->cmd; 2295 cmdlen = 0; 2296 skip_or = 0; 2297 continue; 2298 break; /* NOTREACHED */ 2299 } 2300#undef IS_CALL 2301#undef IS_RETURN 2302 2303 case O_REJECT: 2304 /* 2305 * Drop the packet and send a reject notice 2306 * if the packet is not ICMP (or is an ICMP 2307 * query), and it is not multicast/broadcast. 2308 */ 2309 if (hlen > 0 && is_ipv4 && offset == 0 && 2310 (proto != IPPROTO_ICMP || 2311 is_icmp_query(ICMP(ulp))) && 2312 !(m->m_flags & (M_BCAST|M_MCAST)) && 2313 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 2314 send_reject(args, cmd->arg1, iplen, ip); 2315 m = args->m; 2316 } 2317 /* FALLTHROUGH */ 2318#ifdef INET6 2319 case O_UNREACH6: 2320 if (hlen > 0 && is_ipv6 && 2321 ((offset & IP6F_OFF_MASK) == 0) && 2322 (proto != IPPROTO_ICMPV6 || 2323 (is_icmp6_query(icmp6_type) == 1)) && 2324 !(m->m_flags & (M_BCAST|M_MCAST)) && 2325 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 2326 send_reject6( 2327 args, cmd->arg1, hlen, 2328 (struct ip6_hdr *)ip); 2329 m = args->m; 2330 } 2331 /* FALLTHROUGH */ 2332#endif 2333 case O_DENY: 2334 retval = IP_FW_DENY; 2335 l = 0; /* exit inner loop */ 2336 done = 1; /* exit outer loop */ 2337 break; 2338 2339 case O_FORWARD_IP: 2340 if (args->eh) /* not valid on layer2 pkts */ 2341 break; 2342 if (q == NULL || q->rule != f || 2343 dyn_dir == MATCH_FORWARD) { 2344 struct sockaddr_in *sa; 2345 sa = &(((ipfw_insn_sa *)cmd)->sa); 2346 if (sa->sin_addr.s_addr == INADDR_ANY) { 2347 bcopy(sa, &args->hopstore, 2348 sizeof(*sa)); 2349 args->hopstore.sin_addr.s_addr = 2350 htonl(tablearg); 2351 args->next_hop = &args->hopstore; 2352 } else { 2353 args->next_hop = sa; 2354 } 2355 } 2356 retval = IP_FW_PASS; 2357 l = 0; /* exit inner loop */ 2358 done = 1; /* exit outer loop */ 2359 break; 2360 2361#ifdef INET6 2362 case O_FORWARD_IP6: 2363 if (args->eh) /* not valid on layer2 pkts */ 2364 break; 2365 if (q == NULL || q->rule != f || 2366 dyn_dir == MATCH_FORWARD) { 2367 struct sockaddr_in6 *sin6; 2368 2369 sin6 = &(((ipfw_insn_sa6 *)cmd)->sa); 2370 args->next_hop6 = sin6; 2371 } 2372 retval = IP_FW_PASS; 2373 l = 0; /* exit inner loop */ 2374 done = 1; /* exit outer loop */ 2375 break; 2376#endif 2377 2378 case O_NETGRAPH: 2379 case O_NGTEE: 2380 set_match(args, f_pos, chain); 2381 args->rule.info = IP_FW_ARG_TABLEARG(cmd->arg1); 2382 if (V_fw_one_pass) 2383 args->rule.info |= IPFW_ONEPASS; 2384 retval = (cmd->opcode == O_NETGRAPH) ? 2385 IP_FW_NETGRAPH : IP_FW_NGTEE; 2386 l = 0; /* exit inner loop */ 2387 done = 1; /* exit outer loop */ 2388 break; 2389 2390 case O_SETFIB: { 2391 uint32_t fib; 2392 2393 IPFW_INC_RULE_COUNTER(f, pktlen); 2394 fib = IP_FW_ARG_TABLEARG(cmd->arg1); 2395 if (fib >= rt_numfibs) 2396 fib = 0; 2397 M_SETFIB(m, fib); 2398 args->f_id.fib = fib; 2399 l = 0; /* exit inner loop */ 2400 break; 2401 } 2402 2403 case O_SETDSCP: { 2404 uint16_t code; 2405 2406 code = IP_FW_ARG_TABLEARG(cmd->arg1) & 0x3F; 2407 l = 0; /* exit inner loop */ 2408 if (is_ipv4) { 2409 uint16_t a; 2410 2411 a = ip->ip_tos; 2412 ip->ip_tos = (code << 2) | (ip->ip_tos & 0x03); 2413 a += ntohs(ip->ip_sum) - ip->ip_tos; 2414 ip->ip_sum = htons(a); 2415 } else if (is_ipv6) { 2416 uint8_t *v; 2417 2418 v = &((struct ip6_hdr *)ip)->ip6_vfc; 2419 *v = (*v & 0xF0) | (code >> 2); 2420 v++; 2421 *v = (*v & 0x3F) | ((code & 0x03) << 6); 2422 } else 2423 break; 2424 2425 IPFW_INC_RULE_COUNTER(f, pktlen); 2426 break; 2427 } 2428 2429 case O_NAT: 2430 l = 0; /* exit inner loop */ 2431 done = 1; /* exit outer loop */ 2432 if (!IPFW_NAT_LOADED) { 2433 retval = IP_FW_DENY; 2434 break; 2435 } 2436 2437 struct cfg_nat *t; 2438 int nat_id; 2439 2440 set_match(args, f_pos, chain); 2441 /* Check if this is 'global' nat rule */ 2442 if (cmd->arg1 == 0) { 2443 retval = ipfw_nat_ptr(args, NULL, m); 2444 break; 2445 } 2446 t = ((ipfw_insn_nat *)cmd)->nat; 2447 if (t == NULL) { 2448 nat_id = IP_FW_ARG_TABLEARG(cmd->arg1); 2449 t = (*lookup_nat_ptr)(&chain->nat, nat_id); 2450 2451 if (t == NULL) { 2452 retval = IP_FW_DENY; 2453 break; 2454 } 2455 if (cmd->arg1 != IP_FW_TABLEARG) 2456 ((ipfw_insn_nat *)cmd)->nat = t; 2457 } 2458 retval = ipfw_nat_ptr(args, t, m); 2459 break; 2460 2461 case O_REASS: { 2462 int ip_off; 2463 2464 l = 0; /* in any case exit inner loop */ 2465 if (is_ipv6) /* IPv6 is not supported yet */ 2466 break; 2467 IPFW_INC_RULE_COUNTER(f, pktlen); 2468 ip_off = ntohs(ip->ip_off); 2469 2470 /* if not fragmented, go to next rule */ 2471 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0) 2472 break; 2473 2474 args->m = m = ip_reass(m); 2475 2476 /* 2477 * do IP header checksum fixup. 2478 */ 2479 if (m == NULL) { /* fragment got swallowed */ 2480 retval = IP_FW_DENY; 2481 } else { /* good, packet complete */ 2482 int hlen; 2483 2484 ip = mtod(m, struct ip *); 2485 hlen = ip->ip_hl << 2; 2486 ip->ip_sum = 0; 2487 if (hlen == sizeof(struct ip)) 2488 ip->ip_sum = in_cksum_hdr(ip); 2489 else 2490 ip->ip_sum = in_cksum(m, hlen); 2491 retval = IP_FW_REASS; 2492 set_match(args, f_pos, chain); 2493 } 2494 done = 1; /* exit outer loop */ 2495 break; 2496 } 2497 2498 default: 2499 panic("-- unknown opcode %d\n", cmd->opcode); 2500 } /* end of switch() on opcodes */ 2501 /* 2502 * if we get here with l=0, then match is irrelevant. 2503 */ 2504 2505 if (cmd->len & F_NOT) 2506 match = !match; 2507 2508 if (match) { 2509 if (cmd->len & F_OR) 2510 skip_or = 1; 2511 } else { 2512 if (!(cmd->len & F_OR)) /* not an OR block, */ 2513 break; /* try next rule */ 2514 } 2515 2516 } /* end of inner loop, scan opcodes */ 2517#undef PULLUP_LEN 2518 2519 if (done) 2520 break; 2521 2522/* next_rule:; */ /* try next rule */ 2523 2524 } /* end of outer for, scan rules */ 2525 2526 if (done) { 2527 struct ip_fw *rule = chain->map[f_pos]; 2528 /* Update statistics */ 2529 IPFW_INC_RULE_COUNTER(rule, pktlen); 2530 } else { 2531 retval = IP_FW_DENY; 2532 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 2533 } 2534 IPFW_PF_RUNLOCK(chain); 2535#ifdef __FreeBSD__ 2536 if (ucred_cache != NULL) 2537 crfree(ucred_cache); 2538#endif 2539 return (retval); 2540 2541pullup_failed: 2542 if (V_fw_verbose) 2543 printf("ipfw: pullup failed\n"); 2544 return (IP_FW_DENY); 2545} 2546 2547/* 2548 * Set maximum number of tables that can be used in given VNET ipfw instance. 2549 */ 2550#ifdef SYSCTL_NODE 2551static int 2552sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS) 2553{ 2554 int error; 2555 unsigned int ntables; 2556 2557 ntables = V_fw_tables_max; 2558 2559 error = sysctl_handle_int(oidp, &ntables, 0, req); 2560 /* Read operation or some error */ 2561 if ((error != 0) || (req->newptr == NULL)) 2562 return (error); 2563 2564 return (ipfw_resize_tables(&V_layer3_chain, ntables)); 2565} 2566#endif 2567/* 2568 * Module and VNET glue 2569 */ 2570 2571/* 2572 * Stuff that must be initialised only on boot or module load 2573 */ 2574static int 2575ipfw_init(void) 2576{ 2577 int error = 0; 2578 2579 /* 2580 * Only print out this stuff the first time around, 2581 * when called from the sysinit code. 2582 */ 2583 printf("ipfw2 " 2584#ifdef INET6 2585 "(+ipv6) " 2586#endif 2587 "initialized, divert %s, nat %s, " 2588 "default to %s, logging ", 2589#ifdef IPDIVERT 2590 "enabled", 2591#else 2592 "loadable", 2593#endif 2594#ifdef IPFIREWALL_NAT 2595 "enabled", 2596#else 2597 "loadable", 2598#endif 2599 default_to_accept ? "accept" : "deny"); 2600 2601 /* 2602 * Note: V_xxx variables can be accessed here but the vnet specific 2603 * initializer may not have been called yet for the VIMAGE case. 2604 * Tuneables will have been processed. We will print out values for 2605 * the default vnet. 2606 * XXX This should all be rationalized AFTER 8.0 2607 */ 2608 if (V_fw_verbose == 0) 2609 printf("disabled\n"); 2610 else if (V_verbose_limit == 0) 2611 printf("unlimited\n"); 2612 else 2613 printf("limited to %d packets/entry by default\n", 2614 V_verbose_limit); 2615 2616 /* Check user-supplied table count for validness */ 2617 if (default_fw_tables > IPFW_TABLES_MAX) 2618 default_fw_tables = IPFW_TABLES_MAX; 2619 2620 ipfw_log_bpf(1); /* init */ 2621 return (error); 2622} 2623 2624/* 2625 * Called for the removal of the last instance only on module unload. 2626 */ 2627static void 2628ipfw_destroy(void) 2629{ 2630 2631 ipfw_log_bpf(0); /* uninit */ 2632 printf("IP firewall unloaded\n"); 2633} 2634 2635/* 2636 * Stuff that must be initialized for every instance 2637 * (including the first of course). 2638 */ 2639static int 2640vnet_ipfw_init(const void *unused) 2641{ 2642 int error; 2643 struct ip_fw *rule = NULL; 2644 struct ip_fw_chain *chain; 2645 2646 chain = &V_layer3_chain; 2647 2648 /* First set up some values that are compile time options */ 2649 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 2650 V_fw_deny_unknown_exthdrs = 1; 2651#ifdef IPFIREWALL_VERBOSE 2652 V_fw_verbose = 1; 2653#endif 2654#ifdef IPFIREWALL_VERBOSE_LIMIT 2655 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 2656#endif 2657#ifdef IPFIREWALL_NAT 2658 LIST_INIT(&chain->nat); 2659#endif 2660 2661 /* insert the default rule and create the initial map */ 2662 chain->n_rules = 1; 2663 chain->static_len = sizeof(struct ip_fw); 2664 chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_WAITOK | M_ZERO); 2665 if (chain->map) 2666 rule = malloc(chain->static_len, M_IPFW, M_WAITOK | M_ZERO); 2667 2668 /* Set initial number of tables */ 2669 V_fw_tables_max = default_fw_tables; 2670 error = ipfw_init_tables(chain); 2671 if (error) { 2672 printf("ipfw2: setting up tables failed\n"); 2673 free(chain->map, M_IPFW); 2674 free(rule, M_IPFW); 2675 return (ENOSPC); 2676 } 2677 2678 /* fill and insert the default rule */ 2679 rule->act_ofs = 0; 2680 rule->rulenum = IPFW_DEFAULT_RULE; 2681 rule->cmd_len = 1; 2682 rule->set = RESVD_SET; 2683 rule->cmd[0].len = 1; 2684 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY; 2685 chain->default_rule = chain->map[0] = rule; 2686 chain->id = rule->id = 1; 2687 2688 IPFW_LOCK_INIT(chain); 2689 ipfw_dyn_init(chain); 2690 2691 /* First set up some values that are compile time options */ 2692 V_ipfw_vnet_ready = 1; /* Open for business */ 2693 2694 /* 2695 * Hook the sockopt handler and pfil hooks for ipv4 and ipv6. 2696 * Even if the latter two fail we still keep the module alive 2697 * because the sockopt and layer2 paths are still useful. 2698 * ipfw[6]_hook return 0 on success, ENOENT on failure, 2699 * so we can ignore the exact return value and just set a flag. 2700 * 2701 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so 2702 * changes in the underlying (per-vnet) variables trigger 2703 * immediate hook()/unhook() calls. 2704 * In layer2 we have the same behaviour, except that V_ether_ipfw 2705 * is checked on each packet because there are no pfil hooks. 2706 */ 2707 V_ip_fw_ctl_ptr = ipfw_ctl; 2708 error = ipfw_attach_hooks(1); 2709 return (error); 2710} 2711 2712/* 2713 * Called for the removal of each instance. 2714 */ 2715static int 2716vnet_ipfw_uninit(const void *unused) 2717{ 2718 struct ip_fw *reap, *rule; 2719 struct ip_fw_chain *chain = &V_layer3_chain; 2720 int i; 2721 2722 V_ipfw_vnet_ready = 0; /* tell new callers to go away */ 2723 /* 2724 * disconnect from ipv4, ipv6, layer2 and sockopt. 2725 * Then grab, release and grab again the WLOCK so we make 2726 * sure the update is propagated and nobody will be in. 2727 */ 2728 (void)ipfw_attach_hooks(0 /* detach */); 2729 V_ip_fw_ctl_ptr = NULL; 2730 IPFW_UH_WLOCK(chain); 2731 IPFW_UH_WUNLOCK(chain); 2732 2733 ipfw_dyn_uninit(0); /* run the callout_drain */ 2734 2735 IPFW_UH_WLOCK(chain); 2736 ipfw_destroy_tables(chain); 2737 reap = NULL; 2738 IPFW_WLOCK(chain); 2739 for (i = 0; i < chain->n_rules; i++) { 2740 rule = chain->map[i]; 2741 rule->x_next = reap; 2742 reap = rule; 2743 } 2744 if (chain->map) 2745 free(chain->map, M_IPFW); 2746 IPFW_WUNLOCK(chain); 2747 IPFW_UH_WUNLOCK(chain); 2748 if (reap != NULL) 2749 ipfw_reap_rules(reap); 2750 IPFW_LOCK_DESTROY(chain); 2751 ipfw_dyn_uninit(1); /* free the remaining parts */ 2752 return 0; 2753} 2754 2755/* 2756 * Module event handler. 2757 * In general we have the choice of handling most of these events by the 2758 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to 2759 * use the SYSINIT handlers as they are more capable of expressing the 2760 * flow of control during module and vnet operations, so this is just 2761 * a skeleton. Note there is no SYSINIT equivalent of the module 2762 * SHUTDOWN handler, but we don't have anything to do in that case anyhow. 2763 */ 2764static int 2765ipfw_modevent(module_t mod, int type, void *unused) 2766{ 2767 int err = 0; 2768 2769 switch (type) { 2770 case MOD_LOAD: 2771 /* Called once at module load or 2772 * system boot if compiled in. */ 2773 break; 2774 case MOD_QUIESCE: 2775 /* Called before unload. May veto unloading. */ 2776 break; 2777 case MOD_UNLOAD: 2778 /* Called during unload. */ 2779 break; 2780 case MOD_SHUTDOWN: 2781 /* Called during system shutdown. */ 2782 break; 2783 default: 2784 err = EOPNOTSUPP; 2785 break; 2786 } 2787 return err; 2788} 2789 2790static moduledata_t ipfwmod = { 2791 "ipfw", 2792 ipfw_modevent, 2793 0 2794}; 2795 2796/* Define startup order. */ 2797#define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_IFATTACHDOMAIN 2798#define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */ 2799#define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */ 2800#define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */ 2801 2802DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER); 2803MODULE_VERSION(ipfw, 2); 2804/* should declare some dependencies here */ 2805 2806/* 2807 * Starting up. Done in order after ipfwmod() has been called. 2808 * VNET_SYSINIT is also called for each existing vnet and each new vnet. 2809 */ 2810SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 2811 ipfw_init, NULL); 2812VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 2813 vnet_ipfw_init, NULL); 2814 2815/* 2816 * Closing up shop. These are done in REVERSE ORDER, but still 2817 * after ipfwmod() has been called. Not called on reboot. 2818 * VNET_SYSUNINIT is also called for each exiting vnet as it exits. 2819 * or when the module is unloaded. 2820 */ 2821SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 2822 ipfw_destroy, NULL); 2823VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 2824 vnet_ipfw_uninit, NULL); 2825/* end of file */ 2826