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("$FreeBSD$"); 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/counter.h> 46 #include <sys/eventhandler.h> 47 #include <sys/malloc.h> 48 #include <sys/mbuf.h> 49 #include <sys/kernel.h> 50 #include <sys/lock.h> 51 #include <sys/jail.h> 52 #include <sys/module.h> 53 #include <sys/priv.h> 54 #include <sys/proc.h> 55 #include <sys/rwlock.h> 56 #include <sys/rmlock.h> 57 #include <sys/socket.h> 58 #include <sys/socketvar.h> 59 #include <sys/sysctl.h> 60 #include <sys/syslog.h> 61 #include <sys/ucred.h> 62 #include <net/ethernet.h> /* for ETHERTYPE_IP */ 63 #include <net/if.h> 64 #include <net/if_var.h> 65 #include <net/route.h> 66 #include <net/pfil.h> 67 #include <net/vnet.h> 68 69 #include <netpfil/pf/pf_mtag.h> 70 71 #include <netinet/in.h> 72 #include <netinet/in_var.h> 73 #include <netinet/in_pcb.h> 74 #include <netinet/ip.h> 75 #include <netinet/ip_var.h> 76 #include <netinet/ip_icmp.h> 77 #include <netinet/ip_fw.h> 78 #include <netinet/ip_carp.h> 79 #include <netinet/pim.h> 80 #include <netinet/tcp_var.h> 81 #include <netinet/udp.h> 82 #include <netinet/udp_var.h> 83 #include <netinet/sctp.h> 84 85 #include <netinet/ip6.h> 86 #include <netinet/icmp6.h> 87 #include <netinet/in_fib.h> 88 #ifdef INET6 89 #include <netinet6/in6_fib.h> 90 #include <netinet6/in6_pcb.h> 91 #include <netinet6/scope6_var.h> 92 #include <netinet6/ip6_var.h> 93 #endif 94 95 #include <netpfil/ipfw/ip_fw_private.h> 96 97 #include <machine/in_cksum.h> /* XXX for in_cksum */ 98 99 #ifdef MAC 100 #include <security/mac/mac_framework.h> 101 #endif 102 103 /* 104 * static variables followed by global ones. 105 * All ipfw global variables are here. 106 */ 107 108 static VNET_DEFINE(int, fw_deny_unknown_exthdrs); 109 #define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs) 110 111 static VNET_DEFINE(int, fw_permit_single_frag6) = 1; 112 #define V_fw_permit_single_frag6 VNET(fw_permit_single_frag6) 113 114 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 115 static int default_to_accept = 1; 116 #else 117 static int default_to_accept; 118 #endif 119 120 VNET_DEFINE(int, autoinc_step); 121 VNET_DEFINE(int, fw_one_pass) = 1; 122 123 VNET_DEFINE(unsigned int, fw_tables_max); 124 VNET_DEFINE(unsigned int, fw_tables_sets) = 0; /* Don't use set-aware tables */ 125 /* Use 128 tables by default */ 126 static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT; 127 128 #ifndef LINEAR_SKIPTO 129 static int jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 130 int tablearg, int jump_backwards); 131 #define JUMP(ch, f, num, targ, back) jump_fast(ch, f, num, targ, back) 132 #else 133 static int jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num, 134 int tablearg, int jump_backwards); 135 #define JUMP(ch, f, num, targ, back) jump_linear(ch, f, num, targ, back) 136 #endif 137 138 /* 139 * Each rule belongs to one of 32 different sets (0..31). 140 * The variable set_disable contains one bit per set. 141 * If the bit is set, all rules in the corresponding set 142 * are disabled. Set RESVD_SET(31) is reserved for the default rule 143 * and rules that are not deleted by the flush command, 144 * and CANNOT be disabled. 145 * Rules in set RESVD_SET can only be deleted individually. 146 */ 147 VNET_DEFINE(u_int32_t, set_disable); 148 #define V_set_disable VNET(set_disable) 149 150 VNET_DEFINE(int, fw_verbose); 151 /* counter for ipfw_log(NULL...) */ 152 VNET_DEFINE(u_int64_t, norule_counter); 153 VNET_DEFINE(int, verbose_limit); 154 155 /* layer3_chain contains the list of rules for layer 3 */ 156 VNET_DEFINE(struct ip_fw_chain, layer3_chain); 157 158 /* ipfw_vnet_ready controls when we are open for business */ 159 VNET_DEFINE(int, ipfw_vnet_ready) = 0; 160 161 VNET_DEFINE(int, ipfw_nat_ready) = 0; 162 163 ipfw_nat_t *ipfw_nat_ptr = NULL; 164 struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int); 165 ipfw_nat_cfg_t *ipfw_nat_cfg_ptr; 166 ipfw_nat_cfg_t *ipfw_nat_del_ptr; 167 ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr; 168 ipfw_nat_cfg_t *ipfw_nat_get_log_ptr; 169 170 #ifdef SYSCTL_NODE 171 uint32_t dummy_def = IPFW_DEFAULT_RULE; 172 static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS); 173 static int sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS); 174 175 SYSBEGIN(f3) 176 177 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 178 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass, 179 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0, 180 "Only do a single pass through ipfw when using dummynet(4)"); 181 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, 182 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(autoinc_step), 0, 183 "Rule number auto-increment step"); 184 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, 185 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0, 186 "Log matches to ipfw rules"); 187 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, 188 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(verbose_limit), 0, 189 "Set upper limit of matches of ipfw rules logged"); 190 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD, 191 &dummy_def, 0, 192 "The default/max possible rule number."); 193 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_max, 194 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, 0, 0, sysctl_ipfw_table_num, "IU", 195 "Maximum number of concurrently used tables"); 196 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_sets, 197 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, 198 0, 0, sysctl_ipfw_tables_sets, "IU", 199 "Use per-set namespace for tables"); 200 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN, 201 &default_to_accept, 0, 202 "Make the default rule accept all packets."); 203 TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables); 204 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, 205 CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0, 206 "Number of static rules"); 207 208 #ifdef INET6 209 SYSCTL_DECL(_net_inet6_ip6); 210 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 211 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs, 212 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE, 213 &VNET_NAME(fw_deny_unknown_exthdrs), 0, 214 "Deny packets with unknown IPv6 Extension Headers"); 215 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6, 216 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE, 217 &VNET_NAME(fw_permit_single_frag6), 0, 218 "Permit single packet IPv6 fragments"); 219 #endif /* INET6 */ 220 221 SYSEND 222 223 #endif /* SYSCTL_NODE */ 224 225 226 /* 227 * Some macros used in the various matching options. 228 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T 229 * Other macros just cast void * into the appropriate type 230 */ 231 #define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) 232 #define TCP(p) ((struct tcphdr *)(p)) 233 #define SCTP(p) ((struct sctphdr *)(p)) 234 #define UDP(p) ((struct udphdr *)(p)) 235 #define ICMP(p) ((struct icmphdr *)(p)) 236 #define ICMP6(p) ((struct icmp6_hdr *)(p)) 237 238 static __inline int 239 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) 240 { 241 int type = icmp->icmp_type; 242 243 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) ); 244 } 245 246 #define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \ 247 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) ) 248 249 static int 250 is_icmp_query(struct icmphdr *icmp) 251 { 252 int type = icmp->icmp_type; 253 254 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) ); 255 } 256 #undef TT 257 258 /* 259 * The following checks use two arrays of 8 or 16 bits to store the 260 * bits that we want set or clear, respectively. They are in the 261 * low and high half of cmd->arg1 or cmd->d[0]. 262 * 263 * We scan options and store the bits we find set. We succeed if 264 * 265 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear 266 * 267 * The code is sometimes optimized not to store additional variables. 268 */ 269 270 static int 271 flags_match(ipfw_insn *cmd, u_int8_t bits) 272 { 273 u_char want_clear; 274 bits = ~bits; 275 276 if ( ((cmd->arg1 & 0xff) & bits) != 0) 277 return 0; /* some bits we want set were clear */ 278 want_clear = (cmd->arg1 >> 8) & 0xff; 279 if ( (want_clear & bits) != want_clear) 280 return 0; /* some bits we want clear were set */ 281 return 1; 282 } 283 284 static int 285 ipopts_match(struct ip *ip, ipfw_insn *cmd) 286 { 287 int optlen, bits = 0; 288 u_char *cp = (u_char *)(ip + 1); 289 int x = (ip->ip_hl << 2) - sizeof (struct ip); 290 291 for (; x > 0; x -= optlen, cp += optlen) { 292 int opt = cp[IPOPT_OPTVAL]; 293 294 if (opt == IPOPT_EOL) 295 break; 296 if (opt == IPOPT_NOP) 297 optlen = 1; 298 else { 299 optlen = cp[IPOPT_OLEN]; 300 if (optlen <= 0 || optlen > x) 301 return 0; /* invalid or truncated */ 302 } 303 switch (opt) { 304 305 default: 306 break; 307 308 case IPOPT_LSRR: 309 bits |= IP_FW_IPOPT_LSRR; 310 break; 311 312 case IPOPT_SSRR: 313 bits |= IP_FW_IPOPT_SSRR; 314 break; 315 316 case IPOPT_RR: 317 bits |= IP_FW_IPOPT_RR; 318 break; 319 320 case IPOPT_TS: 321 bits |= IP_FW_IPOPT_TS; 322 break; 323 } 324 } 325 return (flags_match(cmd, bits)); 326 } 327 328 static int 329 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) 330 { 331 int optlen, bits = 0; 332 u_char *cp = (u_char *)(tcp + 1); 333 int x = (tcp->th_off << 2) - sizeof(struct tcphdr); 334 335 for (; x > 0; x -= optlen, cp += optlen) { 336 int opt = cp[0]; 337 if (opt == TCPOPT_EOL) 338 break; 339 if (opt == TCPOPT_NOP) 340 optlen = 1; 341 else { 342 optlen = cp[1]; 343 if (optlen <= 0) 344 break; 345 } 346 347 switch (opt) { 348 349 default: 350 break; 351 352 case TCPOPT_MAXSEG: 353 bits |= IP_FW_TCPOPT_MSS; 354 break; 355 356 case TCPOPT_WINDOW: 357 bits |= IP_FW_TCPOPT_WINDOW; 358 break; 359 360 case TCPOPT_SACK_PERMITTED: 361 case TCPOPT_SACK: 362 bits |= IP_FW_TCPOPT_SACK; 363 break; 364 365 case TCPOPT_TIMESTAMP: 366 bits |= IP_FW_TCPOPT_TS; 367 break; 368 369 } 370 } 371 return (flags_match(cmd, bits)); 372 } 373 374 static int 375 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain, 376 uint32_t *tablearg) 377 { 378 379 if (ifp == NULL) /* no iface with this packet, match fails */ 380 return (0); 381 382 /* Check by name or by IP address */ 383 if (cmd->name[0] != '\0') { /* match by name */ 384 if (cmd->name[0] == '\1') /* use tablearg to match */ 385 return ipfw_lookup_table_extended(chain, cmd->p.kidx, 0, 386 &ifp->if_index, tablearg); 387 /* Check name */ 388 if (cmd->p.glob) { 389 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) 390 return(1); 391 } else { 392 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) 393 return(1); 394 } 395 } else { 396 #if !defined(USERSPACE) && defined(__FreeBSD__) /* and OSX too ? */ 397 struct ifaddr *ia; 398 399 if_addr_rlock(ifp); 400 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 401 if (ia->ifa_addr->sa_family != AF_INET) 402 continue; 403 if (cmd->p.ip.s_addr == ((struct sockaddr_in *) 404 (ia->ifa_addr))->sin_addr.s_addr) { 405 if_addr_runlock(ifp); 406 return(1); /* match */ 407 } 408 } 409 if_addr_runlock(ifp); 410 #endif /* __FreeBSD__ */ 411 } 412 return(0); /* no match, fail ... */ 413 } 414 415 /* 416 * The verify_path function checks if a route to the src exists and 417 * if it is reachable via ifp (when provided). 418 * 419 * The 'verrevpath' option checks that the interface that an IP packet 420 * arrives on is the same interface that traffic destined for the 421 * packet's source address would be routed out of. 422 * The 'versrcreach' option just checks that the source address is 423 * reachable via any route (except default) in the routing table. 424 * These two are a measure to block forged packets. This is also 425 * commonly known as "anti-spoofing" or Unicast Reverse Path 426 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs 427 * is purposely reminiscent of the Cisco IOS command, 428 * 429 * ip verify unicast reverse-path 430 * ip verify unicast source reachable-via any 431 * 432 * which implements the same functionality. But note that the syntax 433 * is misleading, and the check may be performed on all IP packets 434 * whether unicast, multicast, or broadcast. 435 */ 436 static int 437 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib) 438 { 439 #if defined(USERSPACE) || !defined(__FreeBSD__) 440 return 0; 441 #else 442 struct nhop4_basic nh4; 443 444 if (fib4_lookup_nh_basic(fib, src, NHR_IFAIF, 0, &nh4) != 0) 445 return (0); 446 447 /* 448 * If ifp is provided, check for equality with rtentry. 449 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, 450 * in order to pass packets injected back by if_simloop(): 451 * routing entry (via lo0) for our own address 452 * may exist, so we need to handle routing assymetry. 453 */ 454 if (ifp != NULL && ifp != nh4.nh_ifp) 455 return (0); 456 457 /* if no ifp provided, check if rtentry is not default route */ 458 if (ifp == NULL && (nh4.nh_flags & NHF_DEFAULT) != 0) 459 return (0); 460 461 /* or if this is a blackhole/reject route */ 462 if (ifp == NULL && (nh4.nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0) 463 return (0); 464 465 /* found valid route */ 466 return 1; 467 #endif /* __FreeBSD__ */ 468 } 469 470 #ifdef INET6 471 /* 472 * ipv6 specific rules here... 473 */ 474 static __inline int 475 icmp6type_match (int type, ipfw_insn_u32 *cmd) 476 { 477 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); 478 } 479 480 static int 481 flow6id_match( int curr_flow, ipfw_insn_u32 *cmd ) 482 { 483 int i; 484 for (i=0; i <= cmd->o.arg1; ++i ) 485 if (curr_flow == cmd->d[i] ) 486 return 1; 487 return 0; 488 } 489 490 /* support for IP6_*_ME opcodes */ 491 static const struct in6_addr lla_mask = {{{ 492 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 493 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff 494 }}}; 495 496 static int 497 ipfw_localip6(struct in6_addr *in6) 498 { 499 struct rm_priotracker in6_ifa_tracker; 500 struct in6_ifaddr *ia; 501 502 if (IN6_IS_ADDR_MULTICAST(in6)) 503 return (0); 504 505 if (!IN6_IS_ADDR_LINKLOCAL(in6)) 506 return (in6_localip(in6)); 507 508 IN6_IFADDR_RLOCK(&in6_ifa_tracker); 509 TAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) { 510 if (!IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) 511 continue; 512 if (IN6_ARE_MASKED_ADDR_EQUAL(&ia->ia_addr.sin6_addr, 513 in6, &lla_mask)) { 514 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 515 return (1); 516 } 517 } 518 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 519 return (0); 520 } 521 522 static int 523 verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib) 524 { 525 struct nhop6_basic nh6; 526 527 if (IN6_IS_SCOPE_LINKLOCAL(src)) 528 return (1); 529 530 if (fib6_lookup_nh_basic(fib, src, 0, NHR_IFAIF, 0, &nh6) != 0) 531 return (0); 532 533 /* If ifp is provided, check for equality with route table. */ 534 if (ifp != NULL && ifp != nh6.nh_ifp) 535 return (0); 536 537 /* if no ifp provided, check if rtentry is not default route */ 538 if (ifp == NULL && (nh6.nh_flags & NHF_DEFAULT) != 0) 539 return (0); 540 541 /* or if this is a blackhole/reject route */ 542 if (ifp == NULL && (nh6.nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0) 543 return (0); 544 545 /* found valid route */ 546 return 1; 547 } 548 549 static int 550 is_icmp6_query(int icmp6_type) 551 { 552 if ((icmp6_type <= ICMP6_MAXTYPE) && 553 (icmp6_type == ICMP6_ECHO_REQUEST || 554 icmp6_type == ICMP6_MEMBERSHIP_QUERY || 555 icmp6_type == ICMP6_WRUREQUEST || 556 icmp6_type == ICMP6_FQDN_QUERY || 557 icmp6_type == ICMP6_NI_QUERY)) 558 return (1); 559 560 return (0); 561 } 562 563 static void 564 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) 565 { 566 struct mbuf *m; 567 568 m = args->m; 569 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { 570 struct tcphdr *tcp; 571 tcp = (struct tcphdr *)((char *)ip6 + hlen); 572 573 if ((tcp->th_flags & TH_RST) == 0) { 574 struct mbuf *m0; 575 m0 = ipfw_send_pkt(args->m, &(args->f_id), 576 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 577 tcp->th_flags | TH_RST); 578 if (m0 != NULL) 579 ip6_output(m0, NULL, NULL, 0, NULL, NULL, 580 NULL); 581 } 582 FREE_PKT(m); 583 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */ 584 #if 0 585 /* 586 * Unlike above, the mbufs need to line up with the ip6 hdr, 587 * as the contents are read. We need to m_adj() the 588 * needed amount. 589 * The mbuf will however be thrown away so we can adjust it. 590 * Remember we did an m_pullup on it already so we 591 * can make some assumptions about contiguousness. 592 */ 593 if (args->L3offset) 594 m_adj(m, args->L3offset); 595 #endif 596 icmp6_error(m, ICMP6_DST_UNREACH, code, 0); 597 } else 598 FREE_PKT(m); 599 600 args->m = NULL; 601 } 602 603 #endif /* INET6 */ 604 605 606 /* 607 * sends a reject message, consuming the mbuf passed as an argument. 608 */ 609 static void 610 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip) 611 { 612 613 #if 0 614 /* XXX When ip is not guaranteed to be at mtod() we will 615 * need to account for this */ 616 * The mbuf will however be thrown away so we can adjust it. 617 * Remember we did an m_pullup on it already so we 618 * can make some assumptions about contiguousness. 619 */ 620 if (args->L3offset) 621 m_adj(m, args->L3offset); 622 #endif 623 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */ 624 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0); 625 } else if (args->f_id.proto == IPPROTO_TCP) { 626 struct tcphdr *const tcp = 627 L3HDR(struct tcphdr, mtod(args->m, struct ip *)); 628 if ( (tcp->th_flags & TH_RST) == 0) { 629 struct mbuf *m; 630 m = ipfw_send_pkt(args->m, &(args->f_id), 631 ntohl(tcp->th_seq), ntohl(tcp->th_ack), 632 tcp->th_flags | TH_RST); 633 if (m != NULL) 634 ip_output(m, NULL, NULL, 0, NULL, NULL); 635 } 636 FREE_PKT(args->m); 637 } else 638 FREE_PKT(args->m); 639 args->m = NULL; 640 } 641 642 /* 643 * Support for uid/gid/jail lookup. These tests are expensive 644 * (because we may need to look into the list of active sockets) 645 * so we cache the results. ugid_lookupp is 0 if we have not 646 * yet done a lookup, 1 if we succeeded, and -1 if we tried 647 * and failed. The function always returns the match value. 648 * We could actually spare the variable and use *uc, setting 649 * it to '(void *)check_uidgid if we have no info, NULL if 650 * we tried and failed, or any other value if successful. 651 */ 652 static int 653 check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp, 654 struct ucred **uc) 655 { 656 #if defined(USERSPACE) 657 return 0; // not supported in userspace 658 #else 659 #ifndef __FreeBSD__ 660 /* XXX */ 661 return cred_check(insn, proto, oif, 662 dst_ip, dst_port, src_ip, src_port, 663 (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb); 664 #else /* FreeBSD */ 665 struct in_addr src_ip, dst_ip; 666 struct inpcbinfo *pi; 667 struct ipfw_flow_id *id; 668 struct inpcb *pcb, *inp; 669 struct ifnet *oif; 670 int lookupflags; 671 int match; 672 673 id = &args->f_id; 674 inp = args->inp; 675 oif = args->oif; 676 677 /* 678 * Check to see if the UDP or TCP stack supplied us with 679 * the PCB. If so, rather then holding a lock and looking 680 * up the PCB, we can use the one that was supplied. 681 */ 682 if (inp && *ugid_lookupp == 0) { 683 INP_LOCK_ASSERT(inp); 684 if (inp->inp_socket != NULL) { 685 *uc = crhold(inp->inp_cred); 686 *ugid_lookupp = 1; 687 } else 688 *ugid_lookupp = -1; 689 } 690 /* 691 * If we have already been here and the packet has no 692 * PCB entry associated with it, then we can safely 693 * assume that this is a no match. 694 */ 695 if (*ugid_lookupp == -1) 696 return (0); 697 if (id->proto == IPPROTO_TCP) { 698 lookupflags = 0; 699 pi = &V_tcbinfo; 700 } else if (id->proto == IPPROTO_UDP) { 701 lookupflags = INPLOOKUP_WILDCARD; 702 pi = &V_udbinfo; 703 } else 704 return 0; 705 lookupflags |= INPLOOKUP_RLOCKPCB; 706 match = 0; 707 if (*ugid_lookupp == 0) { 708 if (id->addr_type == 6) { 709 #ifdef INET6 710 if (oif == NULL) 711 pcb = in6_pcblookup_mbuf(pi, 712 &id->src_ip6, htons(id->src_port), 713 &id->dst_ip6, htons(id->dst_port), 714 lookupflags, oif, args->m); 715 else 716 pcb = in6_pcblookup_mbuf(pi, 717 &id->dst_ip6, htons(id->dst_port), 718 &id->src_ip6, htons(id->src_port), 719 lookupflags, oif, args->m); 720 #else 721 *ugid_lookupp = -1; 722 return (0); 723 #endif 724 } else { 725 src_ip.s_addr = htonl(id->src_ip); 726 dst_ip.s_addr = htonl(id->dst_ip); 727 if (oif == NULL) 728 pcb = in_pcblookup_mbuf(pi, 729 src_ip, htons(id->src_port), 730 dst_ip, htons(id->dst_port), 731 lookupflags, oif, args->m); 732 else 733 pcb = in_pcblookup_mbuf(pi, 734 dst_ip, htons(id->dst_port), 735 src_ip, htons(id->src_port), 736 lookupflags, oif, args->m); 737 } 738 if (pcb != NULL) { 739 INP_RLOCK_ASSERT(pcb); 740 *uc = crhold(pcb->inp_cred); 741 *ugid_lookupp = 1; 742 INP_RUNLOCK(pcb); 743 } 744 if (*ugid_lookupp == 0) { 745 /* 746 * We tried and failed, set the variable to -1 747 * so we will not try again on this packet. 748 */ 749 *ugid_lookupp = -1; 750 return (0); 751 } 752 } 753 if (insn->o.opcode == O_UID) 754 match = ((*uc)->cr_uid == (uid_t)insn->d[0]); 755 else if (insn->o.opcode == O_GID) 756 match = groupmember((gid_t)insn->d[0], *uc); 757 else if (insn->o.opcode == O_JAIL) 758 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]); 759 return (match); 760 #endif /* __FreeBSD__ */ 761 #endif /* not supported in userspace */ 762 } 763 764 /* 765 * Helper function to set args with info on the rule after the matching 766 * one. slot is precise, whereas we guess rule_id as they are 767 * assigned sequentially. 768 */ 769 static inline void 770 set_match(struct ip_fw_args *args, int slot, 771 struct ip_fw_chain *chain) 772 { 773 args->rule.chain_id = chain->id; 774 args->rule.slot = slot + 1; /* we use 0 as a marker */ 775 args->rule.rule_id = 1 + chain->map[slot]->id; 776 args->rule.rulenum = chain->map[slot]->rulenum; 777 } 778 779 #ifndef LINEAR_SKIPTO 780 /* 781 * Helper function to enable cached rule lookups using 782 * cached_id and cached_pos fields in ipfw rule. 783 */ 784 static int 785 jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num, 786 int tablearg, int jump_backwards) 787 { 788 int f_pos; 789 790 /* If possible use cached f_pos (in f->cached_pos), 791 * whose version is written in f->cached_id 792 * (horrible hacks to avoid changing the ABI). 793 */ 794 if (num != IP_FW_TARG && f->cached_id == chain->id) 795 f_pos = f->cached_pos; 796 else { 797 int i = IP_FW_ARG_TABLEARG(chain, num, skipto); 798 /* make sure we do not jump backward */ 799 if (jump_backwards == 0 && i <= f->rulenum) 800 i = f->rulenum + 1; 801 if (chain->idxmap != NULL) 802 f_pos = chain->idxmap[i]; 803 else 804 f_pos = ipfw_find_rule(chain, i, 0); 805 /* update the cache */ 806 if (num != IP_FW_TARG) { 807 f->cached_id = chain->id; 808 f->cached_pos = f_pos; 809 } 810 } 811 812 return (f_pos); 813 } 814 #else 815 /* 816 * Helper function to enable real fast rule lookups. 817 */ 818 static int 819 jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num, 820 int tablearg, int jump_backwards) 821 { 822 int f_pos; 823 824 num = IP_FW_ARG_TABLEARG(chain, num, skipto); 825 /* make sure we do not jump backward */ 826 if (jump_backwards == 0 && num <= f->rulenum) 827 num = f->rulenum + 1; 828 f_pos = chain->idxmap[num]; 829 830 return (f_pos); 831 } 832 #endif 833 834 #define TARG(k, f) IP_FW_ARG_TABLEARG(chain, k, f) 835 /* 836 * The main check routine for the firewall. 837 * 838 * All arguments are in args so we can modify them and return them 839 * back to the caller. 840 * 841 * Parameters: 842 * 843 * args->m (in/out) The packet; we set to NULL when/if we nuke it. 844 * Starts with the IP header. 845 * args->eh (in) Mac header if present, NULL for layer3 packet. 846 * args->L3offset Number of bytes bypassed if we came from L2. 847 * e.g. often sizeof(eh) ** NOTYET ** 848 * args->oif Outgoing interface, NULL if packet is incoming. 849 * The incoming interface is in the mbuf. (in) 850 * args->divert_rule (in/out) 851 * Skip up to the first rule past this rule number; 852 * upon return, non-zero port number for divert or tee. 853 * 854 * args->rule Pointer to the last matching rule (in/out) 855 * args->next_hop Socket we are forwarding to (out). 856 * args->next_hop6 IPv6 next hop we are forwarding to (out). 857 * args->f_id Addresses grabbed from the packet (out) 858 * args->rule.info a cookie depending on rule action 859 * 860 * Return value: 861 * 862 * IP_FW_PASS the packet must be accepted 863 * IP_FW_DENY the packet must be dropped 864 * IP_FW_DIVERT divert packet, port in m_tag 865 * IP_FW_TEE tee packet, port in m_tag 866 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie 867 * IP_FW_NETGRAPH into netgraph, cookie args->cookie 868 * args->rule contains the matching rule, 869 * args->rule.info has additional information. 870 * 871 */ 872 int 873 ipfw_chk(struct ip_fw_args *args) 874 { 875 876 /* 877 * Local variables holding state while processing a packet: 878 * 879 * IMPORTANT NOTE: to speed up the processing of rules, there 880 * are some assumption on the values of the variables, which 881 * are documented here. Should you change them, please check 882 * the implementation of the various instructions to make sure 883 * that they still work. 884 * 885 * args->eh The MAC header. It is non-null for a layer2 886 * packet, it is NULL for a layer-3 packet. 887 * **notyet** 888 * args->L3offset Offset in the packet to the L3 (IP or equiv.) header. 889 * 890 * m | args->m Pointer to the mbuf, as received from the caller. 891 * It may change if ipfw_chk() does an m_pullup, or if it 892 * consumes the packet because it calls send_reject(). 893 * XXX This has to change, so that ipfw_chk() never modifies 894 * or consumes the buffer. 895 * ip is the beginning of the ip(4 or 6) header. 896 * Calculated by adding the L3offset to the start of data. 897 * (Until we start using L3offset, the packet is 898 * supposed to start with the ip header). 899 */ 900 struct mbuf *m = args->m; 901 struct ip *ip = mtod(m, struct ip *); 902 903 /* 904 * For rules which contain uid/gid or jail constraints, cache 905 * a copy of the users credentials after the pcb lookup has been 906 * executed. This will speed up the processing of rules with 907 * these types of constraints, as well as decrease contention 908 * on pcb related locks. 909 */ 910 #ifndef __FreeBSD__ 911 struct bsd_ucred ucred_cache; 912 #else 913 struct ucred *ucred_cache = NULL; 914 #endif 915 int ucred_lookup = 0; 916 917 /* 918 * oif | args->oif If NULL, ipfw_chk has been called on the 919 * inbound path (ether_input, ip_input). 920 * If non-NULL, ipfw_chk has been called on the outbound path 921 * (ether_output, ip_output). 922 */ 923 struct ifnet *oif = args->oif; 924 925 int f_pos = 0; /* index of current rule in the array */ 926 int retval = 0; 927 928 /* 929 * hlen The length of the IP header. 930 */ 931 u_int hlen = 0; /* hlen >0 means we have an IP pkt */ 932 933 /* 934 * offset The offset of a fragment. offset != 0 means that 935 * we have a fragment at this offset of an IPv4 packet. 936 * offset == 0 means that (if this is an IPv4 packet) 937 * this is the first or only fragment. 938 * For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header 939 * or there is a single packet fragment (fragment header added 940 * without needed). We will treat a single packet fragment as if 941 * there was no fragment header (or log/block depending on the 942 * V_fw_permit_single_frag6 sysctl setting). 943 */ 944 u_short offset = 0; 945 u_short ip6f_mf = 0; 946 947 /* 948 * Local copies of addresses. They are only valid if we have 949 * an IP packet. 950 * 951 * proto The protocol. Set to 0 for non-ip packets, 952 * or to the protocol read from the packet otherwise. 953 * proto != 0 means that we have an IPv4 packet. 954 * 955 * src_port, dst_port port numbers, in HOST format. Only 956 * valid for TCP and UDP packets. 957 * 958 * src_ip, dst_ip ip addresses, in NETWORK format. 959 * Only valid for IPv4 packets. 960 */ 961 uint8_t proto; 962 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */ 963 struct in_addr src_ip, dst_ip; /* NOTE: network format */ 964 uint16_t iplen=0; 965 int pktlen; 966 uint16_t etype = 0; /* Host order stored ether type */ 967 968 /* 969 * dyn_dir = MATCH_UNKNOWN when rules unchecked, 970 * MATCH_NONE when checked and not matched (q = NULL), 971 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL) 972 */ 973 int dyn_dir = MATCH_UNKNOWN; 974 ipfw_dyn_rule *q = NULL; 975 struct ip_fw_chain *chain = &V_layer3_chain; 976 977 /* 978 * We store in ulp a pointer to the upper layer protocol header. 979 * In the ipv4 case this is easy to determine from the header, 980 * but for ipv6 we might have some additional headers in the middle. 981 * ulp is NULL if not found. 982 */ 983 void *ulp = NULL; /* upper layer protocol pointer. */ 984 985 /* XXX ipv6 variables */ 986 int is_ipv6 = 0; 987 uint8_t icmp6_type = 0; 988 uint16_t ext_hd = 0; /* bits vector for extension header filtering */ 989 /* end of ipv6 variables */ 990 991 int is_ipv4 = 0; 992 993 int done = 0; /* flag to exit the outer loop */ 994 IPFW_RLOCK_TRACKER; 995 996 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready)) 997 return (IP_FW_PASS); /* accept */ 998 999 dst_ip.s_addr = 0; /* make sure it is initialized */ 1000 src_ip.s_addr = 0; /* make sure it is initialized */ 1001 pktlen = m->m_pkthdr.len; 1002 args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */ 1003 proto = args->f_id.proto = 0; /* mark f_id invalid */ 1004 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */ 1005 1006 /* 1007 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, 1008 * then it sets p to point at the offset "len" in the mbuf. WARNING: the 1009 * pointer might become stale after other pullups (but we never use it 1010 * this way). 1011 */ 1012 #define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T)) 1013 #define PULLUP_LEN(_len, p, T) \ 1014 do { \ 1015 int x = (_len) + T; \ 1016 if ((m)->m_len < x) { \ 1017 args->m = m = m_pullup(m, x); \ 1018 if (m == NULL) \ 1019 goto pullup_failed; \ 1020 } \ 1021 p = (mtod(m, char *) + (_len)); \ 1022 } while (0) 1023 1024 /* 1025 * if we have an ether header, 1026 */ 1027 if (args->eh) 1028 etype = ntohs(args->eh->ether_type); 1029 1030 /* Identify IP packets and fill up variables. */ 1031 if (pktlen >= sizeof(struct ip6_hdr) && 1032 (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) { 1033 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 1034 is_ipv6 = 1; 1035 args->f_id.addr_type = 6; 1036 hlen = sizeof(struct ip6_hdr); 1037 proto = ip6->ip6_nxt; 1038 1039 /* Search extension headers to find upper layer protocols */ 1040 while (ulp == NULL && offset == 0) { 1041 switch (proto) { 1042 case IPPROTO_ICMPV6: 1043 PULLUP_TO(hlen, ulp, struct icmp6_hdr); 1044 icmp6_type = ICMP6(ulp)->icmp6_type; 1045 break; 1046 1047 case IPPROTO_TCP: 1048 PULLUP_TO(hlen, ulp, struct tcphdr); 1049 dst_port = TCP(ulp)->th_dport; 1050 src_port = TCP(ulp)->th_sport; 1051 /* save flags for dynamic rules */ 1052 args->f_id._flags = TCP(ulp)->th_flags; 1053 break; 1054 1055 case IPPROTO_SCTP: 1056 PULLUP_TO(hlen, ulp, struct sctphdr); 1057 src_port = SCTP(ulp)->src_port; 1058 dst_port = SCTP(ulp)->dest_port; 1059 break; 1060 1061 case IPPROTO_UDP: 1062 PULLUP_TO(hlen, ulp, struct udphdr); 1063 dst_port = UDP(ulp)->uh_dport; 1064 src_port = UDP(ulp)->uh_sport; 1065 break; 1066 1067 case IPPROTO_HOPOPTS: /* RFC 2460 */ 1068 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1069 ext_hd |= EXT_HOPOPTS; 1070 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1071 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1072 ulp = NULL; 1073 break; 1074 1075 case IPPROTO_ROUTING: /* RFC 2460 */ 1076 PULLUP_TO(hlen, ulp, struct ip6_rthdr); 1077 switch (((struct ip6_rthdr *)ulp)->ip6r_type) { 1078 case 0: 1079 ext_hd |= EXT_RTHDR0; 1080 break; 1081 case 2: 1082 ext_hd |= EXT_RTHDR2; 1083 break; 1084 default: 1085 if (V_fw_verbose) 1086 printf("IPFW2: IPV6 - Unknown " 1087 "Routing Header type(%d)\n", 1088 ((struct ip6_rthdr *) 1089 ulp)->ip6r_type); 1090 if (V_fw_deny_unknown_exthdrs) 1091 return (IP_FW_DENY); 1092 break; 1093 } 1094 ext_hd |= EXT_ROUTING; 1095 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; 1096 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; 1097 ulp = NULL; 1098 break; 1099 1100 case IPPROTO_FRAGMENT: /* RFC 2460 */ 1101 PULLUP_TO(hlen, ulp, struct ip6_frag); 1102 ext_hd |= EXT_FRAGMENT; 1103 hlen += sizeof (struct ip6_frag); 1104 proto = ((struct ip6_frag *)ulp)->ip6f_nxt; 1105 offset = ((struct ip6_frag *)ulp)->ip6f_offlg & 1106 IP6F_OFF_MASK; 1107 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg & 1108 IP6F_MORE_FRAG; 1109 if (V_fw_permit_single_frag6 == 0 && 1110 offset == 0 && ip6f_mf == 0) { 1111 if (V_fw_verbose) 1112 printf("IPFW2: IPV6 - Invalid " 1113 "Fragment Header\n"); 1114 if (V_fw_deny_unknown_exthdrs) 1115 return (IP_FW_DENY); 1116 break; 1117 } 1118 args->f_id.extra = 1119 ntohl(((struct ip6_frag *)ulp)->ip6f_ident); 1120 ulp = NULL; 1121 break; 1122 1123 case IPPROTO_DSTOPTS: /* RFC 2460 */ 1124 PULLUP_TO(hlen, ulp, struct ip6_hbh); 1125 ext_hd |= EXT_DSTOPTS; 1126 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; 1127 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; 1128 ulp = NULL; 1129 break; 1130 1131 case IPPROTO_AH: /* RFC 2402 */ 1132 PULLUP_TO(hlen, ulp, struct ip6_ext); 1133 ext_hd |= EXT_AH; 1134 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; 1135 proto = ((struct ip6_ext *)ulp)->ip6e_nxt; 1136 ulp = NULL; 1137 break; 1138 1139 case IPPROTO_ESP: /* RFC 2406 */ 1140 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ 1141 /* Anything past Seq# is variable length and 1142 * data past this ext. header is encrypted. */ 1143 ext_hd |= EXT_ESP; 1144 break; 1145 1146 case IPPROTO_NONE: /* RFC 2460 */ 1147 /* 1148 * Packet ends here, and IPv6 header has 1149 * already been pulled up. If ip6e_len!=0 1150 * then octets must be ignored. 1151 */ 1152 ulp = ip; /* non-NULL to get out of loop. */ 1153 break; 1154 1155 case IPPROTO_OSPFIGP: 1156 /* XXX OSPF header check? */ 1157 PULLUP_TO(hlen, ulp, struct ip6_ext); 1158 break; 1159 1160 case IPPROTO_PIM: 1161 /* XXX PIM header check? */ 1162 PULLUP_TO(hlen, ulp, struct pim); 1163 break; 1164 1165 case IPPROTO_CARP: 1166 PULLUP_TO(hlen, ulp, struct carp_header); 1167 if (((struct carp_header *)ulp)->carp_version != 1168 CARP_VERSION) 1169 return (IP_FW_DENY); 1170 if (((struct carp_header *)ulp)->carp_type != 1171 CARP_ADVERTISEMENT) 1172 return (IP_FW_DENY); 1173 break; 1174 1175 case IPPROTO_IPV6: /* RFC 2893 */ 1176 PULLUP_TO(hlen, ulp, struct ip6_hdr); 1177 break; 1178 1179 case IPPROTO_IPV4: /* RFC 2893 */ 1180 PULLUP_TO(hlen, ulp, struct ip); 1181 break; 1182 1183 default: 1184 if (V_fw_verbose) 1185 printf("IPFW2: IPV6 - Unknown " 1186 "Extension Header(%d), ext_hd=%x\n", 1187 proto, ext_hd); 1188 if (V_fw_deny_unknown_exthdrs) 1189 return (IP_FW_DENY); 1190 PULLUP_TO(hlen, ulp, struct ip6_ext); 1191 break; 1192 } /*switch */ 1193 } 1194 ip = mtod(m, struct ip *); 1195 ip6 = (struct ip6_hdr *)ip; 1196 args->f_id.src_ip6 = ip6->ip6_src; 1197 args->f_id.dst_ip6 = ip6->ip6_dst; 1198 args->f_id.src_ip = 0; 1199 args->f_id.dst_ip = 0; 1200 args->f_id.flow_id6 = ntohl(ip6->ip6_flow); 1201 } else if (pktlen >= sizeof(struct ip) && 1202 (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) { 1203 is_ipv4 = 1; 1204 hlen = ip->ip_hl << 2; 1205 args->f_id.addr_type = 4; 1206 1207 /* 1208 * Collect parameters into local variables for faster matching. 1209 */ 1210 proto = ip->ip_p; 1211 src_ip = ip->ip_src; 1212 dst_ip = ip->ip_dst; 1213 offset = ntohs(ip->ip_off) & IP_OFFMASK; 1214 iplen = ntohs(ip->ip_len); 1215 pktlen = iplen < pktlen ? iplen : pktlen; 1216 1217 if (offset == 0) { 1218 switch (proto) { 1219 case IPPROTO_TCP: 1220 PULLUP_TO(hlen, ulp, struct tcphdr); 1221 dst_port = TCP(ulp)->th_dport; 1222 src_port = TCP(ulp)->th_sport; 1223 /* save flags for dynamic rules */ 1224 args->f_id._flags = TCP(ulp)->th_flags; 1225 break; 1226 1227 case IPPROTO_SCTP: 1228 PULLUP_TO(hlen, ulp, struct sctphdr); 1229 src_port = SCTP(ulp)->src_port; 1230 dst_port = SCTP(ulp)->dest_port; 1231 break; 1232 1233 case IPPROTO_UDP: 1234 PULLUP_TO(hlen, ulp, struct udphdr); 1235 dst_port = UDP(ulp)->uh_dport; 1236 src_port = UDP(ulp)->uh_sport; 1237 break; 1238 1239 case IPPROTO_ICMP: 1240 PULLUP_TO(hlen, ulp, struct icmphdr); 1241 //args->f_id.flags = ICMP(ulp)->icmp_type; 1242 break; 1243 1244 default: 1245 break; 1246 } 1247 } 1248 1249 ip = mtod(m, struct ip *); 1250 args->f_id.src_ip = ntohl(src_ip.s_addr); 1251 args->f_id.dst_ip = ntohl(dst_ip.s_addr); 1252 } 1253 #undef PULLUP_TO 1254 if (proto) { /* we may have port numbers, store them */ 1255 args->f_id.proto = proto; 1256 args->f_id.src_port = src_port = ntohs(src_port); 1257 args->f_id.dst_port = dst_port = ntohs(dst_port); 1258 } 1259 1260 IPFW_PF_RLOCK(chain); 1261 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ 1262 IPFW_PF_RUNLOCK(chain); 1263 return (IP_FW_PASS); /* accept */ 1264 } 1265 if (args->rule.slot) { 1266 /* 1267 * Packet has already been tagged as a result of a previous 1268 * match on rule args->rule aka args->rule_id (PIPE, QUEUE, 1269 * REASS, NETGRAPH, DIVERT/TEE...) 1270 * Validate the slot and continue from the next one 1271 * if still present, otherwise do a lookup. 1272 */ 1273 f_pos = (args->rule.chain_id == chain->id) ? 1274 args->rule.slot : 1275 ipfw_find_rule(chain, args->rule.rulenum, 1276 args->rule.rule_id); 1277 } else { 1278 f_pos = 0; 1279 } 1280 1281 /* 1282 * Now scan the rules, and parse microinstructions for each rule. 1283 * We have two nested loops and an inner switch. Sometimes we 1284 * need to break out of one or both loops, or re-enter one of 1285 * the loops with updated variables. Loop variables are: 1286 * 1287 * f_pos (outer loop) points to the current rule. 1288 * On output it points to the matching rule. 1289 * done (outer loop) is used as a flag to break the loop. 1290 * l (inner loop) residual length of current rule. 1291 * cmd points to the current microinstruction. 1292 * 1293 * We break the inner loop by setting l=0 and possibly 1294 * cmdlen=0 if we don't want to advance cmd. 1295 * We break the outer loop by setting done=1 1296 * We can restart the inner loop by setting l>0 and f_pos, f, cmd 1297 * as needed. 1298 */ 1299 for (; f_pos < chain->n_rules; f_pos++) { 1300 ipfw_insn *cmd; 1301 uint32_t tablearg = 0; 1302 int l, cmdlen, skip_or; /* skip rest of OR block */ 1303 struct ip_fw *f; 1304 1305 f = chain->map[f_pos]; 1306 if (V_set_disable & (1 << f->set) ) 1307 continue; 1308 1309 skip_or = 0; 1310 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; 1311 l -= cmdlen, cmd += cmdlen) { 1312 int match; 1313 1314 /* 1315 * check_body is a jump target used when we find a 1316 * CHECK_STATE, and need to jump to the body of 1317 * the target rule. 1318 */ 1319 1320 /* check_body: */ 1321 cmdlen = F_LEN(cmd); 1322 /* 1323 * An OR block (insn_1 || .. || insn_n) has the 1324 * F_OR bit set in all but the last instruction. 1325 * The first match will set "skip_or", and cause 1326 * the following instructions to be skipped until 1327 * past the one with the F_OR bit clear. 1328 */ 1329 if (skip_or) { /* skip this instruction */ 1330 if ((cmd->len & F_OR) == 0) 1331 skip_or = 0; /* next one is good */ 1332 continue; 1333 } 1334 match = 0; /* set to 1 if we succeed */ 1335 1336 switch (cmd->opcode) { 1337 /* 1338 * The first set of opcodes compares the packet's 1339 * fields with some pattern, setting 'match' if a 1340 * match is found. At the end of the loop there is 1341 * logic to deal with F_NOT and F_OR flags associated 1342 * with the opcode. 1343 */ 1344 case O_NOP: 1345 match = 1; 1346 break; 1347 1348 case O_FORWARD_MAC: 1349 printf("ipfw: opcode %d unimplemented\n", 1350 cmd->opcode); 1351 break; 1352 1353 case O_GID: 1354 case O_UID: 1355 case O_JAIL: 1356 /* 1357 * We only check offset == 0 && proto != 0, 1358 * as this ensures that we have a 1359 * packet with the ports info. 1360 */ 1361 if (offset != 0) 1362 break; 1363 if (proto == IPPROTO_TCP || 1364 proto == IPPROTO_UDP) 1365 match = check_uidgid( 1366 (ipfw_insn_u32 *)cmd, 1367 args, &ucred_lookup, 1368 #ifdef __FreeBSD__ 1369 &ucred_cache); 1370 #else 1371 (void *)&ucred_cache); 1372 #endif 1373 break; 1374 1375 case O_RECV: 1376 match = iface_match(m->m_pkthdr.rcvif, 1377 (ipfw_insn_if *)cmd, chain, &tablearg); 1378 break; 1379 1380 case O_XMIT: 1381 match = iface_match(oif, (ipfw_insn_if *)cmd, 1382 chain, &tablearg); 1383 break; 1384 1385 case O_VIA: 1386 match = iface_match(oif ? oif : 1387 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd, 1388 chain, &tablearg); 1389 break; 1390 1391 case O_MACADDR2: 1392 if (args->eh != NULL) { /* have MAC header */ 1393 u_int32_t *want = (u_int32_t *) 1394 ((ipfw_insn_mac *)cmd)->addr; 1395 u_int32_t *mask = (u_int32_t *) 1396 ((ipfw_insn_mac *)cmd)->mask; 1397 u_int32_t *hdr = (u_int32_t *)args->eh; 1398 1399 match = 1400 ( want[0] == (hdr[0] & mask[0]) && 1401 want[1] == (hdr[1] & mask[1]) && 1402 want[2] == (hdr[2] & mask[2]) ); 1403 } 1404 break; 1405 1406 case O_MAC_TYPE: 1407 if (args->eh != NULL) { 1408 u_int16_t *p = 1409 ((ipfw_insn_u16 *)cmd)->ports; 1410 int i; 1411 1412 for (i = cmdlen - 1; !match && i>0; 1413 i--, p += 2) 1414 match = (etype >= p[0] && 1415 etype <= p[1]); 1416 } 1417 break; 1418 1419 case O_FRAG: 1420 match = (offset != 0); 1421 break; 1422 1423 case O_IN: /* "out" is "not in" */ 1424 match = (oif == NULL); 1425 break; 1426 1427 case O_LAYER2: 1428 match = (args->eh != NULL); 1429 break; 1430 1431 case O_DIVERTED: 1432 { 1433 /* For diverted packets, args->rule.info 1434 * contains the divert port (in host format) 1435 * reason and direction. 1436 */ 1437 uint32_t i = args->rule.info; 1438 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT && 1439 cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2); 1440 } 1441 break; 1442 1443 case O_PROTO: 1444 /* 1445 * We do not allow an arg of 0 so the 1446 * check of "proto" only suffices. 1447 */ 1448 match = (proto == cmd->arg1); 1449 break; 1450 1451 case O_IP_SRC: 1452 match = is_ipv4 && 1453 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1454 src_ip.s_addr); 1455 break; 1456 1457 case O_IP_SRC_LOOKUP: 1458 case O_IP_DST_LOOKUP: 1459 if (is_ipv4) { 1460 uint32_t key = 1461 (cmd->opcode == O_IP_DST_LOOKUP) ? 1462 dst_ip.s_addr : src_ip.s_addr; 1463 uint32_t v = 0; 1464 1465 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { 1466 /* generic lookup. The key must be 1467 * in 32bit big-endian format. 1468 */ 1469 v = ((ipfw_insn_u32 *)cmd)->d[1]; 1470 if (v == 0) 1471 key = dst_ip.s_addr; 1472 else if (v == 1) 1473 key = src_ip.s_addr; 1474 else if (v == 6) /* dscp */ 1475 key = (ip->ip_tos >> 2) & 0x3f; 1476 else if (offset != 0) 1477 break; 1478 else if (proto != IPPROTO_TCP && 1479 proto != IPPROTO_UDP) 1480 break; 1481 else if (v == 2) 1482 key = dst_port; 1483 else if (v == 3) 1484 key = src_port; 1485 #ifndef USERSPACE 1486 else if (v == 4 || v == 5) { 1487 check_uidgid( 1488 (ipfw_insn_u32 *)cmd, 1489 args, &ucred_lookup, 1490 #ifdef __FreeBSD__ 1491 &ucred_cache); 1492 if (v == 4 /* O_UID */) 1493 key = ucred_cache->cr_uid; 1494 else if (v == 5 /* O_JAIL */) 1495 key = ucred_cache->cr_prison->pr_id; 1496 #else /* !__FreeBSD__ */ 1497 (void *)&ucred_cache); 1498 if (v ==4 /* O_UID */) 1499 key = ucred_cache.uid; 1500 else if (v == 5 /* O_JAIL */) 1501 key = ucred_cache.xid; 1502 #endif /* !__FreeBSD__ */ 1503 } 1504 #endif /* !USERSPACE */ 1505 else 1506 break; 1507 } 1508 match = ipfw_lookup_table(chain, 1509 cmd->arg1, key, &v); 1510 if (!match) 1511 break; 1512 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1513 match = 1514 ((ipfw_insn_u32 *)cmd)->d[0] == v; 1515 else 1516 tablearg = v; 1517 } else if (is_ipv6) { 1518 uint32_t v = 0; 1519 void *pkey = (cmd->opcode == O_IP_DST_LOOKUP) ? 1520 &args->f_id.dst_ip6: &args->f_id.src_ip6; 1521 match = ipfw_lookup_table_extended(chain, 1522 cmd->arg1, 1523 sizeof(struct in6_addr), 1524 pkey, &v); 1525 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1526 match = ((ipfw_insn_u32 *)cmd)->d[0] == v; 1527 if (match) 1528 tablearg = v; 1529 } 1530 break; 1531 1532 case O_IP_FLOW_LOOKUP: 1533 { 1534 uint32_t v = 0; 1535 match = ipfw_lookup_table_extended(chain, 1536 cmd->arg1, 0, &args->f_id, &v); 1537 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) 1538 match = ((ipfw_insn_u32 *)cmd)->d[0] == v; 1539 if (match) 1540 tablearg = v; 1541 } 1542 break; 1543 case O_IP_SRC_MASK: 1544 case O_IP_DST_MASK: 1545 if (is_ipv4) { 1546 uint32_t a = 1547 (cmd->opcode == O_IP_DST_MASK) ? 1548 dst_ip.s_addr : src_ip.s_addr; 1549 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; 1550 int i = cmdlen-1; 1551 1552 for (; !match && i>0; i-= 2, p+= 2) 1553 match = (p[0] == (a & p[1])); 1554 } 1555 break; 1556 1557 case O_IP_SRC_ME: 1558 if (is_ipv4) { 1559 struct ifnet *tif; 1560 1561 INADDR_TO_IFP(src_ip, tif); 1562 match = (tif != NULL); 1563 break; 1564 } 1565 #ifdef INET6 1566 /* FALLTHROUGH */ 1567 case O_IP6_SRC_ME: 1568 match= is_ipv6 && ipfw_localip6(&args->f_id.src_ip6); 1569 #endif 1570 break; 1571 1572 case O_IP_DST_SET: 1573 case O_IP_SRC_SET: 1574 if (is_ipv4) { 1575 u_int32_t *d = (u_int32_t *)(cmd+1); 1576 u_int32_t addr = 1577 cmd->opcode == O_IP_DST_SET ? 1578 args->f_id.dst_ip : 1579 args->f_id.src_ip; 1580 1581 if (addr < d[0]) 1582 break; 1583 addr -= d[0]; /* subtract base */ 1584 match = (addr < cmd->arg1) && 1585 ( d[ 1 + (addr>>5)] & 1586 (1<<(addr & 0x1f)) ); 1587 } 1588 break; 1589 1590 case O_IP_DST: 1591 match = is_ipv4 && 1592 (((ipfw_insn_ip *)cmd)->addr.s_addr == 1593 dst_ip.s_addr); 1594 break; 1595 1596 case O_IP_DST_ME: 1597 if (is_ipv4) { 1598 struct ifnet *tif; 1599 1600 INADDR_TO_IFP(dst_ip, tif); 1601 match = (tif != NULL); 1602 break; 1603 } 1604 #ifdef INET6 1605 /* FALLTHROUGH */ 1606 case O_IP6_DST_ME: 1607 match= is_ipv6 && ipfw_localip6(&args->f_id.dst_ip6); 1608 #endif 1609 break; 1610 1611 1612 case O_IP_SRCPORT: 1613 case O_IP_DSTPORT: 1614 /* 1615 * offset == 0 && proto != 0 is enough 1616 * to guarantee that we have a 1617 * packet with port info. 1618 */ 1619 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP) 1620 && offset == 0) { 1621 u_int16_t x = 1622 (cmd->opcode == O_IP_SRCPORT) ? 1623 src_port : dst_port ; 1624 u_int16_t *p = 1625 ((ipfw_insn_u16 *)cmd)->ports; 1626 int i; 1627 1628 for (i = cmdlen - 1; !match && i>0; 1629 i--, p += 2) 1630 match = (x>=p[0] && x<=p[1]); 1631 } 1632 break; 1633 1634 case O_ICMPTYPE: 1635 match = (offset == 0 && proto==IPPROTO_ICMP && 1636 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); 1637 break; 1638 1639 #ifdef INET6 1640 case O_ICMP6TYPE: 1641 match = is_ipv6 && offset == 0 && 1642 proto==IPPROTO_ICMPV6 && 1643 icmp6type_match( 1644 ICMP6(ulp)->icmp6_type, 1645 (ipfw_insn_u32 *)cmd); 1646 break; 1647 #endif /* INET6 */ 1648 1649 case O_IPOPT: 1650 match = (is_ipv4 && 1651 ipopts_match(ip, cmd) ); 1652 break; 1653 1654 case O_IPVER: 1655 match = (is_ipv4 && 1656 cmd->arg1 == ip->ip_v); 1657 break; 1658 1659 case O_IPID: 1660 case O_IPLEN: 1661 case O_IPTTL: 1662 if (is_ipv4) { /* only for IP packets */ 1663 uint16_t x; 1664 uint16_t *p; 1665 int i; 1666 1667 if (cmd->opcode == O_IPLEN) 1668 x = iplen; 1669 else if (cmd->opcode == O_IPTTL) 1670 x = ip->ip_ttl; 1671 else /* must be IPID */ 1672 x = ntohs(ip->ip_id); 1673 if (cmdlen == 1) { 1674 match = (cmd->arg1 == x); 1675 break; 1676 } 1677 /* otherwise we have ranges */ 1678 p = ((ipfw_insn_u16 *)cmd)->ports; 1679 i = cmdlen - 1; 1680 for (; !match && i>0; i--, p += 2) 1681 match = (x >= p[0] && x <= p[1]); 1682 } 1683 break; 1684 1685 case O_IPPRECEDENCE: 1686 match = (is_ipv4 && 1687 (cmd->arg1 == (ip->ip_tos & 0xe0)) ); 1688 break; 1689 1690 case O_IPTOS: 1691 match = (is_ipv4 && 1692 flags_match(cmd, ip->ip_tos)); 1693 break; 1694 1695 case O_DSCP: 1696 { 1697 uint32_t *p; 1698 uint16_t x; 1699 1700 p = ((ipfw_insn_u32 *)cmd)->d; 1701 1702 if (is_ipv4) 1703 x = ip->ip_tos >> 2; 1704 else if (is_ipv6) { 1705 uint8_t *v; 1706 v = &((struct ip6_hdr *)ip)->ip6_vfc; 1707 x = (*v & 0x0F) << 2; 1708 v++; 1709 x |= *v >> 6; 1710 } else 1711 break; 1712 1713 /* DSCP bitmask is stored as low_u32 high_u32 */ 1714 if (x >= 32) 1715 match = *(p + 1) & (1 << (x - 32)); 1716 else 1717 match = *p & (1 << x); 1718 } 1719 break; 1720 1721 case O_TCPDATALEN: 1722 if (proto == IPPROTO_TCP && offset == 0) { 1723 struct tcphdr *tcp; 1724 uint16_t x; 1725 uint16_t *p; 1726 int i; 1727 1728 tcp = TCP(ulp); 1729 x = iplen - 1730 ((ip->ip_hl + tcp->th_off) << 2); 1731 if (cmdlen == 1) { 1732 match = (cmd->arg1 == x); 1733 break; 1734 } 1735 /* otherwise we have ranges */ 1736 p = ((ipfw_insn_u16 *)cmd)->ports; 1737 i = cmdlen - 1; 1738 for (; !match && i>0; i--, p += 2) 1739 match = (x >= p[0] && x <= p[1]); 1740 } 1741 break; 1742 1743 case O_TCPFLAGS: 1744 match = (proto == IPPROTO_TCP && offset == 0 && 1745 flags_match(cmd, TCP(ulp)->th_flags)); 1746 break; 1747 1748 case O_TCPOPTS: 1749 if (proto == IPPROTO_TCP && offset == 0 && ulp){ 1750 PULLUP_LEN(hlen, ulp, 1751 (TCP(ulp)->th_off << 2)); 1752 match = tcpopts_match(TCP(ulp), cmd); 1753 } 1754 break; 1755 1756 case O_TCPSEQ: 1757 match = (proto == IPPROTO_TCP && offset == 0 && 1758 ((ipfw_insn_u32 *)cmd)->d[0] == 1759 TCP(ulp)->th_seq); 1760 break; 1761 1762 case O_TCPACK: 1763 match = (proto == IPPROTO_TCP && offset == 0 && 1764 ((ipfw_insn_u32 *)cmd)->d[0] == 1765 TCP(ulp)->th_ack); 1766 break; 1767 1768 case O_TCPWIN: 1769 if (proto == IPPROTO_TCP && offset == 0) { 1770 uint16_t x; 1771 uint16_t *p; 1772 int i; 1773 1774 x = ntohs(TCP(ulp)->th_win); 1775 if (cmdlen == 1) { 1776 match = (cmd->arg1 == x); 1777 break; 1778 } 1779 /* Otherwise we have ranges. */ 1780 p = ((ipfw_insn_u16 *)cmd)->ports; 1781 i = cmdlen - 1; 1782 for (; !match && i > 0; i--, p += 2) 1783 match = (x >= p[0] && x <= p[1]); 1784 } 1785 break; 1786 1787 case O_ESTAB: 1788 /* reject packets which have SYN only */ 1789 /* XXX should i also check for TH_ACK ? */ 1790 match = (proto == IPPROTO_TCP && offset == 0 && 1791 (TCP(ulp)->th_flags & 1792 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); 1793 break; 1794 1795 case O_ALTQ: { 1796 struct pf_mtag *at; 1797 struct m_tag *mtag; 1798 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; 1799 1800 /* 1801 * ALTQ uses mbuf tags from another 1802 * packet filtering system - pf(4). 1803 * We allocate a tag in its format 1804 * and fill it in, pretending to be pf(4). 1805 */ 1806 match = 1; 1807 at = pf_find_mtag(m); 1808 if (at != NULL && at->qid != 0) 1809 break; 1810 mtag = m_tag_get(PACKET_TAG_PF, 1811 sizeof(struct pf_mtag), M_NOWAIT | M_ZERO); 1812 if (mtag == NULL) { 1813 /* 1814 * Let the packet fall back to the 1815 * default ALTQ. 1816 */ 1817 break; 1818 } 1819 m_tag_prepend(m, mtag); 1820 at = (struct pf_mtag *)(mtag + 1); 1821 at->qid = altq->qid; 1822 at->hdr = ip; 1823 break; 1824 } 1825 1826 case O_LOG: 1827 ipfw_log(chain, f, hlen, args, m, 1828 oif, offset | ip6f_mf, tablearg, ip); 1829 match = 1; 1830 break; 1831 1832 case O_PROB: 1833 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); 1834 break; 1835 1836 case O_VERREVPATH: 1837 /* Outgoing packets automatically pass/match */ 1838 match = ((oif != NULL) || 1839 (m->m_pkthdr.rcvif == NULL) || 1840 ( 1841 #ifdef INET6 1842 is_ipv6 ? 1843 verify_path6(&(args->f_id.src_ip6), 1844 m->m_pkthdr.rcvif, args->f_id.fib) : 1845 #endif 1846 verify_path(src_ip, m->m_pkthdr.rcvif, 1847 args->f_id.fib))); 1848 break; 1849 1850 case O_VERSRCREACH: 1851 /* Outgoing packets automatically pass/match */ 1852 match = (hlen > 0 && ((oif != NULL) || 1853 #ifdef INET6 1854 is_ipv6 ? 1855 verify_path6(&(args->f_id.src_ip6), 1856 NULL, args->f_id.fib) : 1857 #endif 1858 verify_path(src_ip, NULL, args->f_id.fib))); 1859 break; 1860 1861 case O_ANTISPOOF: 1862 /* Outgoing packets automatically pass/match */ 1863 if (oif == NULL && hlen > 0 && 1864 ( (is_ipv4 && in_localaddr(src_ip)) 1865 #ifdef INET6 1866 || (is_ipv6 && 1867 in6_localaddr(&(args->f_id.src_ip6))) 1868 #endif 1869 )) 1870 match = 1871 #ifdef INET6 1872 is_ipv6 ? verify_path6( 1873 &(args->f_id.src_ip6), 1874 m->m_pkthdr.rcvif, 1875 args->f_id.fib) : 1876 #endif 1877 verify_path(src_ip, 1878 m->m_pkthdr.rcvif, 1879 args->f_id.fib); 1880 else 1881 match = 1; 1882 break; 1883 1884 case O_IPSEC: 1885 #ifdef IPSEC 1886 match = (m_tag_find(m, 1887 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); 1888 #endif 1889 /* otherwise no match */ 1890 break; 1891 1892 #ifdef INET6 1893 case O_IP6_SRC: 1894 match = is_ipv6 && 1895 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, 1896 &((ipfw_insn_ip6 *)cmd)->addr6); 1897 break; 1898 1899 case O_IP6_DST: 1900 match = is_ipv6 && 1901 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, 1902 &((ipfw_insn_ip6 *)cmd)->addr6); 1903 break; 1904 case O_IP6_SRC_MASK: 1905 case O_IP6_DST_MASK: 1906 if (is_ipv6) { 1907 int i = cmdlen - 1; 1908 struct in6_addr p; 1909 struct in6_addr *d = 1910 &((ipfw_insn_ip6 *)cmd)->addr6; 1911 1912 for (; !match && i > 0; d += 2, 1913 i -= F_INSN_SIZE(struct in6_addr) 1914 * 2) { 1915 p = (cmd->opcode == 1916 O_IP6_SRC_MASK) ? 1917 args->f_id.src_ip6: 1918 args->f_id.dst_ip6; 1919 APPLY_MASK(&p, &d[1]); 1920 match = 1921 IN6_ARE_ADDR_EQUAL(&d[0], 1922 &p); 1923 } 1924 } 1925 break; 1926 1927 case O_FLOW6ID: 1928 match = is_ipv6 && 1929 flow6id_match(args->f_id.flow_id6, 1930 (ipfw_insn_u32 *) cmd); 1931 break; 1932 1933 case O_EXT_HDR: 1934 match = is_ipv6 && 1935 (ext_hd & ((ipfw_insn *) cmd)->arg1); 1936 break; 1937 1938 case O_IP6: 1939 match = is_ipv6; 1940 break; 1941 #endif 1942 1943 case O_IP4: 1944 match = is_ipv4; 1945 break; 1946 1947 case O_TAG: { 1948 struct m_tag *mtag; 1949 uint32_t tag = TARG(cmd->arg1, tag); 1950 1951 /* Packet is already tagged with this tag? */ 1952 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); 1953 1954 /* We have `untag' action when F_NOT flag is 1955 * present. And we must remove this mtag from 1956 * mbuf and reset `match' to zero (`match' will 1957 * be inversed later). 1958 * Otherwise we should allocate new mtag and 1959 * push it into mbuf. 1960 */ 1961 if (cmd->len & F_NOT) { /* `untag' action */ 1962 if (mtag != NULL) 1963 m_tag_delete(m, mtag); 1964 match = 0; 1965 } else { 1966 if (mtag == NULL) { 1967 mtag = m_tag_alloc( MTAG_IPFW, 1968 tag, 0, M_NOWAIT); 1969 if (mtag != NULL) 1970 m_tag_prepend(m, mtag); 1971 } 1972 match = 1; 1973 } 1974 break; 1975 } 1976 1977 case O_FIB: /* try match the specified fib */ 1978 if (args->f_id.fib == cmd->arg1) 1979 match = 1; 1980 break; 1981 1982 case O_SOCKARG: { 1983 #ifndef USERSPACE /* not supported in userspace */ 1984 struct inpcb *inp = args->inp; 1985 struct inpcbinfo *pi; 1986 1987 if (is_ipv6) /* XXX can we remove this ? */ 1988 break; 1989 1990 if (proto == IPPROTO_TCP) 1991 pi = &V_tcbinfo; 1992 else if (proto == IPPROTO_UDP) 1993 pi = &V_udbinfo; 1994 else 1995 break; 1996 1997 /* 1998 * XXXRW: so_user_cookie should almost 1999 * certainly be inp_user_cookie? 2000 */ 2001 2002 /* For incoming packet, lookup up the 2003 inpcb using the src/dest ip/port tuple */ 2004 if (inp == NULL) { 2005 inp = in_pcblookup(pi, 2006 src_ip, htons(src_port), 2007 dst_ip, htons(dst_port), 2008 INPLOOKUP_RLOCKPCB, NULL); 2009 if (inp != NULL) { 2010 tablearg = 2011 inp->inp_socket->so_user_cookie; 2012 if (tablearg) 2013 match = 1; 2014 INP_RUNLOCK(inp); 2015 } 2016 } else { 2017 if (inp->inp_socket) { 2018 tablearg = 2019 inp->inp_socket->so_user_cookie; 2020 if (tablearg) 2021 match = 1; 2022 } 2023 } 2024 #endif /* !USERSPACE */ 2025 break; 2026 } 2027 2028 case O_TAGGED: { 2029 struct m_tag *mtag; 2030 uint32_t tag = TARG(cmd->arg1, tag); 2031 2032 if (cmdlen == 1) { 2033 match = m_tag_locate(m, MTAG_IPFW, 2034 tag, NULL) != NULL; 2035 break; 2036 } 2037 2038 /* we have ranges */ 2039 for (mtag = m_tag_first(m); 2040 mtag != NULL && !match; 2041 mtag = m_tag_next(m, mtag)) { 2042 uint16_t *p; 2043 int i; 2044 2045 if (mtag->m_tag_cookie != MTAG_IPFW) 2046 continue; 2047 2048 p = ((ipfw_insn_u16 *)cmd)->ports; 2049 i = cmdlen - 1; 2050 for(; !match && i > 0; i--, p += 2) 2051 match = 2052 mtag->m_tag_id >= p[0] && 2053 mtag->m_tag_id <= p[1]; 2054 } 2055 break; 2056 } 2057 2058 /* 2059 * The second set of opcodes represents 'actions', 2060 * i.e. the terminal part of a rule once the packet 2061 * matches all previous patterns. 2062 * Typically there is only one action for each rule, 2063 * and the opcode is stored at the end of the rule 2064 * (but there are exceptions -- see below). 2065 * 2066 * In general, here we set retval and terminate the 2067 * outer loop (would be a 'break 3' in some language, 2068 * but we need to set l=0, done=1) 2069 * 2070 * Exceptions: 2071 * O_COUNT and O_SKIPTO actions: 2072 * instead of terminating, we jump to the next rule 2073 * (setting l=0), or to the SKIPTO target (setting 2074 * f/f_len, cmd and l as needed), respectively. 2075 * 2076 * O_TAG, O_LOG and O_ALTQ action parameters: 2077 * perform some action and set match = 1; 2078 * 2079 * O_LIMIT and O_KEEP_STATE: these opcodes are 2080 * not real 'actions', and are stored right 2081 * before the 'action' part of the rule. 2082 * These opcodes try to install an entry in the 2083 * state tables; if successful, we continue with 2084 * the next opcode (match=1; break;), otherwise 2085 * the packet must be dropped (set retval, 2086 * break loops with l=0, done=1) 2087 * 2088 * O_PROBE_STATE and O_CHECK_STATE: these opcodes 2089 * cause a lookup of the state table, and a jump 2090 * to the 'action' part of the parent rule 2091 * if an entry is found, or 2092 * (CHECK_STATE only) a jump to the next rule if 2093 * the entry is not found. 2094 * The result of the lookup is cached so that 2095 * further instances of these opcodes become NOPs. 2096 * The jump to the next rule is done by setting 2097 * l=0, cmdlen=0. 2098 */ 2099 case O_LIMIT: 2100 case O_KEEP_STATE: 2101 if (ipfw_install_state(chain, f, 2102 (ipfw_insn_limit *)cmd, args, tablearg)) { 2103 /* error or limit violation */ 2104 retval = IP_FW_DENY; 2105 l = 0; /* exit inner loop */ 2106 done = 1; /* exit outer loop */ 2107 } 2108 match = 1; 2109 break; 2110 2111 case O_PROBE_STATE: 2112 case O_CHECK_STATE: 2113 /* 2114 * dynamic rules are checked at the first 2115 * keep-state or check-state occurrence, 2116 * with the result being stored in dyn_dir. 2117 * The compiler introduces a PROBE_STATE 2118 * instruction for us when we have a 2119 * KEEP_STATE (because PROBE_STATE needs 2120 * to be run first). 2121 */ 2122 if (dyn_dir == MATCH_UNKNOWN && 2123 (q = ipfw_lookup_dyn_rule(&args->f_id, 2124 &dyn_dir, proto == IPPROTO_TCP ? 2125 TCP(ulp) : NULL)) 2126 != NULL) { 2127 /* 2128 * Found dynamic entry, update stats 2129 * and jump to the 'action' part of 2130 * the parent rule by setting 2131 * f, cmd, l and clearing cmdlen. 2132 */ 2133 IPFW_INC_DYN_COUNTER(q, pktlen); 2134 /* XXX we would like to have f_pos 2135 * readily accessible in the dynamic 2136 * rule, instead of having to 2137 * lookup q->rule. 2138 */ 2139 f = q->rule; 2140 f_pos = ipfw_find_rule(chain, 2141 f->rulenum, f->id); 2142 cmd = ACTION_PTR(f); 2143 l = f->cmd_len - f->act_ofs; 2144 ipfw_dyn_unlock(q); 2145 cmdlen = 0; 2146 match = 1; 2147 break; 2148 } 2149 /* 2150 * Dynamic entry not found. If CHECK_STATE, 2151 * skip to next rule, if PROBE_STATE just 2152 * ignore and continue with next opcode. 2153 */ 2154 if (cmd->opcode == O_CHECK_STATE) 2155 l = 0; /* exit inner loop */ 2156 match = 1; 2157 break; 2158 2159 case O_ACCEPT: 2160 retval = 0; /* accept */ 2161 l = 0; /* exit inner loop */ 2162 done = 1; /* exit outer loop */ 2163 break; 2164 2165 case O_PIPE: 2166 case O_QUEUE: 2167 set_match(args, f_pos, chain); 2168 args->rule.info = TARG(cmd->arg1, pipe); 2169 if (cmd->opcode == O_PIPE) 2170 args->rule.info |= IPFW_IS_PIPE; 2171 if (V_fw_one_pass) 2172 args->rule.info |= IPFW_ONEPASS; 2173 retval = IP_FW_DUMMYNET; 2174 l = 0; /* exit inner loop */ 2175 done = 1; /* exit outer loop */ 2176 break; 2177 2178 case O_DIVERT: 2179 case O_TEE: 2180 if (args->eh) /* not on layer 2 */ 2181 break; 2182 /* otherwise this is terminal */ 2183 l = 0; /* exit inner loop */ 2184 done = 1; /* exit outer loop */ 2185 retval = (cmd->opcode == O_DIVERT) ? 2186 IP_FW_DIVERT : IP_FW_TEE; 2187 set_match(args, f_pos, chain); 2188 args->rule.info = TARG(cmd->arg1, divert); 2189 break; 2190 2191 case O_COUNT: 2192 IPFW_INC_RULE_COUNTER(f, pktlen); 2193 l = 0; /* exit inner loop */ 2194 break; 2195 2196 case O_SKIPTO: 2197 IPFW_INC_RULE_COUNTER(f, pktlen); 2198 f_pos = JUMP(chain, f, cmd->arg1, tablearg, 0); 2199 /* 2200 * Skip disabled rules, and re-enter 2201 * the inner loop with the correct 2202 * f_pos, f, l and cmd. 2203 * Also clear cmdlen and skip_or 2204 */ 2205 for (; f_pos < chain->n_rules - 1 && 2206 (V_set_disable & 2207 (1 << chain->map[f_pos]->set)); 2208 f_pos++) 2209 ; 2210 /* Re-enter the inner loop at the skipto rule. */ 2211 f = chain->map[f_pos]; 2212 l = f->cmd_len; 2213 cmd = f->cmd; 2214 match = 1; 2215 cmdlen = 0; 2216 skip_or = 0; 2217 continue; 2218 break; /* not reached */ 2219 2220 case O_CALLRETURN: { 2221 /* 2222 * Implementation of `subroutine' call/return, 2223 * in the stack carried in an mbuf tag. This 2224 * is different from `skipto' in that any call 2225 * address is possible (`skipto' must prevent 2226 * backward jumps to avoid endless loops). 2227 * We have `return' action when F_NOT flag is 2228 * present. The `m_tag_id' field is used as 2229 * stack pointer. 2230 */ 2231 struct m_tag *mtag; 2232 uint16_t jmpto, *stack; 2233 2234 #define IS_CALL ((cmd->len & F_NOT) == 0) 2235 #define IS_RETURN ((cmd->len & F_NOT) != 0) 2236 /* 2237 * Hand-rolled version of m_tag_locate() with 2238 * wildcard `type'. 2239 * If not already tagged, allocate new tag. 2240 */ 2241 mtag = m_tag_first(m); 2242 while (mtag != NULL) { 2243 if (mtag->m_tag_cookie == 2244 MTAG_IPFW_CALL) 2245 break; 2246 mtag = m_tag_next(m, mtag); 2247 } 2248 if (mtag == NULL && IS_CALL) { 2249 mtag = m_tag_alloc(MTAG_IPFW_CALL, 0, 2250 IPFW_CALLSTACK_SIZE * 2251 sizeof(uint16_t), M_NOWAIT); 2252 if (mtag != NULL) 2253 m_tag_prepend(m, mtag); 2254 } 2255 2256 /* 2257 * On error both `call' and `return' just 2258 * continue with next rule. 2259 */ 2260 if (IS_RETURN && (mtag == NULL || 2261 mtag->m_tag_id == 0)) { 2262 l = 0; /* exit inner loop */ 2263 break; 2264 } 2265 if (IS_CALL && (mtag == NULL || 2266 mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) { 2267 printf("ipfw: call stack error, " 2268 "go to next rule\n"); 2269 l = 0; /* exit inner loop */ 2270 break; 2271 } 2272 2273 IPFW_INC_RULE_COUNTER(f, pktlen); 2274 stack = (uint16_t *)(mtag + 1); 2275 2276 /* 2277 * The `call' action may use cached f_pos 2278 * (in f->next_rule), whose version is written 2279 * in f->next_rule. 2280 * The `return' action, however, doesn't have 2281 * fixed jump address in cmd->arg1 and can't use 2282 * cache. 2283 */ 2284 if (IS_CALL) { 2285 stack[mtag->m_tag_id] = f->rulenum; 2286 mtag->m_tag_id++; 2287 f_pos = JUMP(chain, f, cmd->arg1, 2288 tablearg, 1); 2289 } else { /* `return' action */ 2290 mtag->m_tag_id--; 2291 jmpto = stack[mtag->m_tag_id] + 1; 2292 f_pos = ipfw_find_rule(chain, jmpto, 0); 2293 } 2294 2295 /* 2296 * Skip disabled rules, and re-enter 2297 * the inner loop with the correct 2298 * f_pos, f, l and cmd. 2299 * Also clear cmdlen and skip_or 2300 */ 2301 for (; f_pos < chain->n_rules - 1 && 2302 (V_set_disable & 2303 (1 << chain->map[f_pos]->set)); f_pos++) 2304 ; 2305 /* Re-enter the inner loop at the dest rule. */ 2306 f = chain->map[f_pos]; 2307 l = f->cmd_len; 2308 cmd = f->cmd; 2309 cmdlen = 0; 2310 skip_or = 0; 2311 continue; 2312 break; /* NOTREACHED */ 2313 } 2314 #undef IS_CALL 2315 #undef IS_RETURN 2316 2317 case O_REJECT: 2318 /* 2319 * Drop the packet and send a reject notice 2320 * if the packet is not ICMP (or is an ICMP 2321 * query), and it is not multicast/broadcast. 2322 */ 2323 if (hlen > 0 && is_ipv4 && offset == 0 && 2324 (proto != IPPROTO_ICMP || 2325 is_icmp_query(ICMP(ulp))) && 2326 !(m->m_flags & (M_BCAST|M_MCAST)) && 2327 !IN_MULTICAST(ntohl(dst_ip.s_addr))) { 2328 send_reject(args, cmd->arg1, iplen, ip); 2329 m = args->m; 2330 } 2331 /* FALLTHROUGH */ 2332 #ifdef INET6 2333 case O_UNREACH6: 2334 if (hlen > 0 && is_ipv6 && 2335 ((offset & IP6F_OFF_MASK) == 0) && 2336 (proto != IPPROTO_ICMPV6 || 2337 (is_icmp6_query(icmp6_type) == 1)) && 2338 !(m->m_flags & (M_BCAST|M_MCAST)) && 2339 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) { 2340 send_reject6( 2341 args, cmd->arg1, hlen, 2342 (struct ip6_hdr *)ip); 2343 m = args->m; 2344 } 2345 /* FALLTHROUGH */ 2346 #endif 2347 case O_DENY: 2348 retval = IP_FW_DENY; 2349 l = 0; /* exit inner loop */ 2350 done = 1; /* exit outer loop */ 2351 break; 2352 2353 case O_FORWARD_IP: 2354 if (args->eh) /* not valid on layer2 pkts */ 2355 break; 2356 if (q == NULL || q->rule != f || 2357 dyn_dir == MATCH_FORWARD) { 2358 struct sockaddr_in *sa; 2359 2360 sa = &(((ipfw_insn_sa *)cmd)->sa); 2361 if (sa->sin_addr.s_addr == INADDR_ANY) { 2362 #ifdef INET6 2363 /* 2364 * We use O_FORWARD_IP opcode for 2365 * fwd rule with tablearg, but tables 2366 * now support IPv6 addresses. And 2367 * when we are inspecting IPv6 packet, 2368 * we can use nh6 field from 2369 * table_value as next_hop6 address. 2370 */ 2371 if (is_ipv6) { 2372 struct sockaddr_in6 *sa6; 2373 2374 sa6 = args->next_hop6 = 2375 &args->hopstore6; 2376 sa6->sin6_family = AF_INET6; 2377 sa6->sin6_len = sizeof(*sa6); 2378 sa6->sin6_addr = TARG_VAL( 2379 chain, tablearg, nh6); 2380 /* 2381 * Set sin6_scope_id only for 2382 * link-local unicast addresses. 2383 */ 2384 if (IN6_IS_ADDR_LINKLOCAL( 2385 &sa6->sin6_addr)) 2386 sa6->sin6_scope_id = 2387 TARG_VAL(chain, 2388 tablearg, 2389 zoneid); 2390 } else 2391 #endif 2392 { 2393 sa = args->next_hop = 2394 &args->hopstore; 2395 sa->sin_family = AF_INET; 2396 sa->sin_len = sizeof(*sa); 2397 sa->sin_addr.s_addr = htonl( 2398 TARG_VAL(chain, tablearg, 2399 nh4)); 2400 } 2401 } else { 2402 args->next_hop = sa; 2403 } 2404 } 2405 retval = IP_FW_PASS; 2406 l = 0; /* exit inner loop */ 2407 done = 1; /* exit outer loop */ 2408 break; 2409 2410 #ifdef INET6 2411 case O_FORWARD_IP6: 2412 if (args->eh) /* not valid on layer2 pkts */ 2413 break; 2414 if (q == NULL || q->rule != f || 2415 dyn_dir == MATCH_FORWARD) { 2416 struct sockaddr_in6 *sin6; 2417 2418 sin6 = &(((ipfw_insn_sa6 *)cmd)->sa); 2419 args->next_hop6 = sin6; 2420 } 2421 retval = IP_FW_PASS; 2422 l = 0; /* exit inner loop */ 2423 done = 1; /* exit outer loop */ 2424 break; 2425 #endif 2426 2427 case O_NETGRAPH: 2428 case O_NGTEE: 2429 set_match(args, f_pos, chain); 2430 args->rule.info = TARG(cmd->arg1, netgraph); 2431 if (V_fw_one_pass) 2432 args->rule.info |= IPFW_ONEPASS; 2433 retval = (cmd->opcode == O_NETGRAPH) ? 2434 IP_FW_NETGRAPH : IP_FW_NGTEE; 2435 l = 0; /* exit inner loop */ 2436 done = 1; /* exit outer loop */ 2437 break; 2438 2439 case O_SETFIB: { 2440 uint32_t fib; 2441 2442 IPFW_INC_RULE_COUNTER(f, pktlen); 2443 fib = TARG(cmd->arg1, fib) & 0x7FFF; 2444 if (fib >= rt_numfibs) 2445 fib = 0; 2446 M_SETFIB(m, fib); 2447 args->f_id.fib = fib; 2448 l = 0; /* exit inner loop */ 2449 break; 2450 } 2451 2452 case O_SETDSCP: { 2453 uint16_t code; 2454 2455 code = TARG(cmd->arg1, dscp) & 0x3F; 2456 l = 0; /* exit inner loop */ 2457 if (is_ipv4) { 2458 uint16_t old; 2459 2460 old = *(uint16_t *)ip; 2461 ip->ip_tos = (code << 2) | 2462 (ip->ip_tos & 0x03); 2463 ip->ip_sum = cksum_adjust(ip->ip_sum, 2464 old, *(uint16_t *)ip); 2465 } else if (is_ipv6) { 2466 uint8_t *v; 2467 2468 v = &((struct ip6_hdr *)ip)->ip6_vfc; 2469 *v = (*v & 0xF0) | (code >> 2); 2470 v++; 2471 *v = (*v & 0x3F) | ((code & 0x03) << 6); 2472 } else 2473 break; 2474 2475 IPFW_INC_RULE_COUNTER(f, pktlen); 2476 break; 2477 } 2478 2479 case O_NAT: 2480 l = 0; /* exit inner loop */ 2481 done = 1; /* exit outer loop */ 2482 if (!IPFW_NAT_LOADED) { 2483 retval = IP_FW_DENY; 2484 break; 2485 } 2486 2487 struct cfg_nat *t; 2488 int nat_id; 2489 2490 set_match(args, f_pos, chain); 2491 /* Check if this is 'global' nat rule */ 2492 if (cmd->arg1 == 0) { 2493 retval = ipfw_nat_ptr(args, NULL, m); 2494 break; 2495 } 2496 t = ((ipfw_insn_nat *)cmd)->nat; 2497 if (t == NULL) { 2498 nat_id = TARG(cmd->arg1, nat); 2499 t = (*lookup_nat_ptr)(&chain->nat, nat_id); 2500 2501 if (t == NULL) { 2502 retval = IP_FW_DENY; 2503 break; 2504 } 2505 if (cmd->arg1 != IP_FW_TARG) 2506 ((ipfw_insn_nat *)cmd)->nat = t; 2507 } 2508 retval = ipfw_nat_ptr(args, t, m); 2509 break; 2510 2511 case O_REASS: { 2512 int ip_off; 2513 2514 IPFW_INC_RULE_COUNTER(f, pktlen); 2515 l = 0; /* in any case exit inner loop */ 2516 ip_off = ntohs(ip->ip_off); 2517 2518 /* if not fragmented, go to next rule */ 2519 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0) 2520 break; 2521 2522 args->m = m = ip_reass(m); 2523 2524 /* 2525 * do IP header checksum fixup. 2526 */ 2527 if (m == NULL) { /* fragment got swallowed */ 2528 retval = IP_FW_DENY; 2529 } else { /* good, packet complete */ 2530 int hlen; 2531 2532 ip = mtod(m, struct ip *); 2533 hlen = ip->ip_hl << 2; 2534 ip->ip_sum = 0; 2535 if (hlen == sizeof(struct ip)) 2536 ip->ip_sum = in_cksum_hdr(ip); 2537 else 2538 ip->ip_sum = in_cksum(m, hlen); 2539 retval = IP_FW_REASS; 2540 set_match(args, f_pos, chain); 2541 } 2542 done = 1; /* exit outer loop */ 2543 break; 2544 } 2545 case O_EXTERNAL_ACTION: 2546 l = 0; /* in any case exit inner loop */ 2547 retval = ipfw_run_eaction(chain, args, 2548 cmd, &done); 2549 break; 2550 2551 default: 2552 panic("-- unknown opcode %d\n", cmd->opcode); 2553 } /* end of switch() on opcodes */ 2554 /* 2555 * if we get here with l=0, then match is irrelevant. 2556 */ 2557 2558 if (cmd->len & F_NOT) 2559 match = !match; 2560 2561 if (match) { 2562 if (cmd->len & F_OR) 2563 skip_or = 1; 2564 } else { 2565 if (!(cmd->len & F_OR)) /* not an OR block, */ 2566 break; /* try next rule */ 2567 } 2568 2569 } /* end of inner loop, scan opcodes */ 2570 #undef PULLUP_LEN 2571 2572 if (done) 2573 break; 2574 2575 /* next_rule:; */ /* try next rule */ 2576 2577 } /* end of outer for, scan rules */ 2578 2579 if (done) { 2580 struct ip_fw *rule = chain->map[f_pos]; 2581 /* Update statistics */ 2582 IPFW_INC_RULE_COUNTER(rule, pktlen); 2583 } else { 2584 retval = IP_FW_DENY; 2585 printf("ipfw: ouch!, skip past end of rules, denying packet\n"); 2586 } 2587 IPFW_PF_RUNLOCK(chain); 2588 #ifdef __FreeBSD__ 2589 if (ucred_cache != NULL) 2590 crfree(ucred_cache); 2591 #endif 2592 return (retval); 2593 2594 pullup_failed: 2595 if (V_fw_verbose) 2596 printf("ipfw: pullup failed\n"); 2597 return (IP_FW_DENY); 2598 } 2599 2600 /* 2601 * Set maximum number of tables that can be used in given VNET ipfw instance. 2602 */ 2603 #ifdef SYSCTL_NODE 2604 static int 2605 sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS) 2606 { 2607 int error; 2608 unsigned int ntables; 2609 2610 ntables = V_fw_tables_max; 2611 2612 error = sysctl_handle_int(oidp, &ntables, 0, req); 2613 /* Read operation or some error */ 2614 if ((error != 0) || (req->newptr == NULL)) 2615 return (error); 2616 2617 return (ipfw_resize_tables(&V_layer3_chain, ntables)); 2618 } 2619 2620 /* 2621 * Switches table namespace between global and per-set. 2622 */ 2623 static int 2624 sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS) 2625 { 2626 int error; 2627 unsigned int sets; 2628 2629 sets = V_fw_tables_sets; 2630 2631 error = sysctl_handle_int(oidp, &sets, 0, req); 2632 /* Read operation or some error */ 2633 if ((error != 0) || (req->newptr == NULL)) 2634 return (error); 2635 2636 return (ipfw_switch_tables_namespace(&V_layer3_chain, sets)); 2637 } 2638 #endif 2639 2640 /* 2641 * Module and VNET glue 2642 */ 2643 2644 /* 2645 * Stuff that must be initialised only on boot or module load 2646 */ 2647 static int 2648 ipfw_init(void) 2649 { 2650 int error = 0; 2651 2652 /* 2653 * Only print out this stuff the first time around, 2654 * when called from the sysinit code. 2655 */ 2656 printf("ipfw2 " 2657 #ifdef INET6 2658 "(+ipv6) " 2659 #endif 2660 "initialized, divert %s, nat %s, " 2661 "default to %s, logging ", 2662 #ifdef IPDIVERT 2663 "enabled", 2664 #else 2665 "loadable", 2666 #endif 2667 #ifdef IPFIREWALL_NAT 2668 "enabled", 2669 #else 2670 "loadable", 2671 #endif 2672 default_to_accept ? "accept" : "deny"); 2673 2674 /* 2675 * Note: V_xxx variables can be accessed here but the vnet specific 2676 * initializer may not have been called yet for the VIMAGE case. 2677 * Tuneables will have been processed. We will print out values for 2678 * the default vnet. 2679 * XXX This should all be rationalized AFTER 8.0 2680 */ 2681 if (V_fw_verbose == 0) 2682 printf("disabled\n"); 2683 else if (V_verbose_limit == 0) 2684 printf("unlimited\n"); 2685 else 2686 printf("limited to %d packets/entry by default\n", 2687 V_verbose_limit); 2688 2689 /* Check user-supplied table count for validness */ 2690 if (default_fw_tables > IPFW_TABLES_MAX) 2691 default_fw_tables = IPFW_TABLES_MAX; 2692 2693 ipfw_init_sopt_handler(); 2694 ipfw_log_bpf(1); /* init */ 2695 ipfw_iface_init(); 2696 return (error); 2697 } 2698 2699 /* 2700 * Called for the removal of the last instance only on module unload. 2701 */ 2702 static void 2703 ipfw_destroy(void) 2704 { 2705 2706 ipfw_iface_destroy(); 2707 ipfw_log_bpf(0); /* uninit */ 2708 ipfw_destroy_sopt_handler(); 2709 printf("IP firewall unloaded\n"); 2710 } 2711 2712 /* 2713 * Stuff that must be initialized for every instance 2714 * (including the first of course). 2715 */ 2716 static int 2717 vnet_ipfw_init(const void *unused) 2718 { 2719 int error, first; 2720 struct ip_fw *rule = NULL; 2721 struct ip_fw_chain *chain; 2722 2723 chain = &V_layer3_chain; 2724 2725 first = IS_DEFAULT_VNET(curvnet) ? 1 : 0; 2726 2727 /* First set up some values that are compile time options */ 2728 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ 2729 V_fw_deny_unknown_exthdrs = 1; 2730 #ifdef IPFIREWALL_VERBOSE 2731 V_fw_verbose = 1; 2732 #endif 2733 #ifdef IPFIREWALL_VERBOSE_LIMIT 2734 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 2735 #endif 2736 #ifdef IPFIREWALL_NAT 2737 LIST_INIT(&chain->nat); 2738 #endif 2739 2740 /* Init shared services hash table */ 2741 ipfw_init_srv(chain); 2742 2743 ipfw_init_obj_rewriter(); 2744 ipfw_init_counters(); 2745 /* insert the default rule and create the initial map */ 2746 chain->n_rules = 1; 2747 chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_WAITOK | M_ZERO); 2748 rule = ipfw_alloc_rule(chain, sizeof(struct ip_fw)); 2749 2750 /* Set initial number of tables */ 2751 V_fw_tables_max = default_fw_tables; 2752 error = ipfw_init_tables(chain, first); 2753 if (error) { 2754 printf("ipfw2: setting up tables failed\n"); 2755 free(chain->map, M_IPFW); 2756 free(rule, M_IPFW); 2757 return (ENOSPC); 2758 } 2759 2760 /* fill and insert the default rule */ 2761 rule->act_ofs = 0; 2762 rule->rulenum = IPFW_DEFAULT_RULE; 2763 rule->cmd_len = 1; 2764 rule->set = RESVD_SET; 2765 rule->cmd[0].len = 1; 2766 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY; 2767 chain->default_rule = chain->map[0] = rule; 2768 chain->id = rule->id = 1; 2769 /* Pre-calculate rules length for legacy dump format */ 2770 chain->static_len = sizeof(struct ip_fw_rule0); 2771 2772 IPFW_LOCK_INIT(chain); 2773 ipfw_dyn_init(chain); 2774 ipfw_eaction_init(chain, first); 2775 #ifdef LINEAR_SKIPTO 2776 ipfw_init_skipto_cache(chain); 2777 #endif 2778 2779 /* First set up some values that are compile time options */ 2780 V_ipfw_vnet_ready = 1; /* Open for business */ 2781 2782 /* 2783 * Hook the sockopt handler and pfil hooks for ipv4 and ipv6. 2784 * Even if the latter two fail we still keep the module alive 2785 * because the sockopt and layer2 paths are still useful. 2786 * ipfw[6]_hook return 0 on success, ENOENT on failure, 2787 * so we can ignore the exact return value and just set a flag. 2788 * 2789 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so 2790 * changes in the underlying (per-vnet) variables trigger 2791 * immediate hook()/unhook() calls. 2792 * In layer2 we have the same behaviour, except that V_ether_ipfw 2793 * is checked on each packet because there are no pfil hooks. 2794 */ 2795 V_ip_fw_ctl_ptr = ipfw_ctl3; 2796 error = ipfw_attach_hooks(1); 2797 return (error); 2798 } 2799 2800 /* 2801 * Called for the removal of each instance. 2802 */ 2803 static int 2804 vnet_ipfw_uninit(const void *unused) 2805 { 2806 struct ip_fw *reap; 2807 struct ip_fw_chain *chain = &V_layer3_chain; 2808 int i, last; 2809 2810 V_ipfw_vnet_ready = 0; /* tell new callers to go away */ 2811 /* 2812 * disconnect from ipv4, ipv6, layer2 and sockopt. 2813 * Then grab, release and grab again the WLOCK so we make 2814 * sure the update is propagated and nobody will be in. 2815 */ 2816 (void)ipfw_attach_hooks(0 /* detach */); 2817 V_ip_fw_ctl_ptr = NULL; 2818 2819 last = IS_DEFAULT_VNET(curvnet) ? 1 : 0; 2820 2821 IPFW_UH_WLOCK(chain); 2822 IPFW_UH_WUNLOCK(chain); 2823 2824 ipfw_dyn_uninit(0); /* run the callout_drain */ 2825 2826 IPFW_UH_WLOCK(chain); 2827 2828 reap = NULL; 2829 IPFW_WLOCK(chain); 2830 for (i = 0; i < chain->n_rules; i++) 2831 ipfw_reap_add(chain, &reap, chain->map[i]); 2832 free(chain->map, M_IPFW); 2833 #ifdef LINEAR_SKIPTO 2834 ipfw_destroy_skipto_cache(chain); 2835 #endif 2836 IPFW_WUNLOCK(chain); 2837 IPFW_UH_WUNLOCK(chain); 2838 ipfw_destroy_tables(chain, last); 2839 ipfw_eaction_uninit(chain, last); 2840 if (reap != NULL) 2841 ipfw_reap_rules(reap); 2842 vnet_ipfw_iface_destroy(chain); 2843 ipfw_destroy_srv(chain); 2844 IPFW_LOCK_DESTROY(chain); 2845 ipfw_dyn_uninit(1); /* free the remaining parts */ 2846 ipfw_destroy_counters(); 2847 ipfw_destroy_obj_rewriter(); 2848 return (0); 2849 } 2850 2851 /* 2852 * Module event handler. 2853 * In general we have the choice of handling most of these events by the 2854 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to 2855 * use the SYSINIT handlers as they are more capable of expressing the 2856 * flow of control during module and vnet operations, so this is just 2857 * a skeleton. Note there is no SYSINIT equivalent of the module 2858 * SHUTDOWN handler, but we don't have anything to do in that case anyhow. 2859 */ 2860 static int 2861 ipfw_modevent(module_t mod, int type, void *unused) 2862 { 2863 int err = 0; 2864 2865 switch (type) { 2866 case MOD_LOAD: 2867 /* Called once at module load or 2868 * system boot if compiled in. */ 2869 break; 2870 case MOD_QUIESCE: 2871 /* Called before unload. May veto unloading. */ 2872 break; 2873 case MOD_UNLOAD: 2874 /* Called during unload. */ 2875 break; 2876 case MOD_SHUTDOWN: 2877 /* Called during system shutdown. */ 2878 break; 2879 default: 2880 err = EOPNOTSUPP; 2881 break; 2882 } 2883 return err; 2884 } 2885 2886 static moduledata_t ipfwmod = { 2887 "ipfw", 2888 ipfw_modevent, 2889 0 2890 }; 2891 2892 /* Define startup order. */ 2893 #define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_IFATTACHDOMAIN 2894 #define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */ 2895 #define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */ 2896 #define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */ 2897 2898 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER); 2899 FEATURE(ipfw_ctl3, "ipfw new sockopt calls"); 2900 MODULE_VERSION(ipfw, 3); 2901 /* should declare some dependencies here */ 2902 2903 /* 2904 * Starting up. Done in order after ipfwmod() has been called. 2905 * VNET_SYSINIT is also called for each existing vnet and each new vnet. 2906 */ 2907 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 2908 ipfw_init, NULL); 2909 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 2910 vnet_ipfw_init, NULL); 2911 2912 /* 2913 * Closing up shop. These are done in REVERSE ORDER, but still 2914 * after ipfwmod() has been called. Not called on reboot. 2915 * VNET_SYSUNINIT is also called for each exiting vnet as it exits. 2916 * or when the module is unloaded. 2917 */ 2918 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, 2919 ipfw_destroy, NULL); 2920 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, 2921 vnet_ipfw_uninit, NULL); 2922 /* end of file */ 2923