Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/netinet/ip_fw.c
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1 /* 2 * Copyright (c) 1993 Daniel Boulet 3 * Copyright (c) 1994 Ugen J.S.Antsilevich 4 * Copyright (c) 1996 Alex Nash 5 * Copyright (c) 2000 Luigi Rizzo 6 * 7 * Redistribution and use in source forms, with and without modification, 8 * are permitted provided that this entire comment appears intact. 9 * 10 * Redistribution in binary form may occur without any restrictions. 11 * Obviously, it would be nice if you gave credit where credit is due 12 * but requiring it would be too onerous. 13 * 14 * This software is provided ``AS IS'' without any warranties of any kind. 15 * 16 * $FreeBSD$ 17 */ 18 19 #define STATEFUL 1 20 #define DEB(x) 21 #define DDB(x) x 22 23 /* 24 * Implement IP packet firewall 25 */ 26 27 #if !defined(KLD_MODULE) && !defined(IPFIREWALL_MODULE) 28 #include "opt_ipfw.h" 29 #include "opt_ipdn.h" 30 #include "opt_ipdivert.h" 31 #include "opt_inet.h" 32 #ifndef INET 33 #error IPFIREWALL requires INET. 34 #endif /* INET */ 35 #endif 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/malloc.h> 40 #include <sys/mbuf.h> 41 #include <sys/kernel.h> 42 #include <sys/proc.h> 43 #include <sys/socket.h> 44 #include <sys/socketvar.h> 45 #include <sys/sysctl.h> 46 #include <sys/ucred.h> 47 #include <net/if.h> 48 #include <net/route.h> 49 #include <netinet/in.h> 50 #include <netinet/in_systm.h> 51 #include <netinet/in_pcb.h> 52 #include <netinet/ip.h> 53 #include <netinet/ip_var.h> 54 #include <netinet/ip_icmp.h> 55 #include <netinet/ip_fw.h> 56 #ifdef DUMMYNET 57 #include <netinet/ip_dummynet.h> 58 #endif 59 #include <netinet/tcp.h> 60 #include <netinet/tcp_timer.h> 61 #include <netinet/tcp_var.h> 62 #include <netinet/tcpip.h> 63 #include <netinet/udp.h> 64 #include <netinet/udp_var.h> 65 66 #include <netinet/if_ether.h> /* XXX ethertype_ip */ 67 68 static int fw_debug = 1; 69 #ifdef IPFIREWALL_VERBOSE 70 static int fw_verbose = 1; 71 #else 72 static int fw_verbose = 0; 73 #endif 74 int fw_one_pass = 1 ; 75 #ifdef IPFIREWALL_VERBOSE_LIMIT 76 static int fw_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; 77 #else 78 static int fw_verbose_limit = 0; 79 #endif 80 81 static u_int64_t counter; /* counter for ipfw_report(NULL...) */ 82 struct ipfw_flow_id last_pkt ; 83 84 #define IPFW_DEFAULT_RULE ((u_int)(u_short)~0) 85 86 LIST_HEAD (ip_fw_head, ip_fw_chain) ip_fw_chain; 87 88 MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's"); 89 90 #ifdef SYSCTL_NODE 91 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall"); 92 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, enable, CTLFLAG_RW, 93 &fw_enable, 0, "Enable ipfw"); 94 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO,one_pass,CTLFLAG_RW, 95 &fw_one_pass, 0, 96 "Only do a single pass through ipfw when using divert(4)/dummynet(4)"); 97 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW, 98 &fw_debug, 0, "Enable printing of debug ip_fw statements"); 99 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, CTLFLAG_RW, 100 &fw_verbose, 0, "Log matches to ipfw rules"); 101 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, 102 &fw_verbose_limit, 0, "Set upper limit of matches of ipfw rules logged"); 103 104 #if STATEFUL 105 /* 106 * Extension for stateful ipfw. 107 * 108 * Dynamic rules are stored in lists accessed through a hash table 109 * (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can 110 * be modified through the sysctl variable dyn_buckets which is 111 * updated when the table becomes empty. 112 * 113 * XXX currently there is only one list, ipfw_dyn. 114 * 115 * When a packet is received, it is first hashed, then matched 116 * against the entries in the corresponding list. 117 * Matching occurs according to the rule type. The default is to 118 * match the four fields and the protocol, and rules are bidirectional. 119 * 120 * For a busy proxy/web server we will have lots of connections to 121 * the server. We could decide for a rule type where we ignore 122 * ports (different hashing) and avoid special SYN/RST/FIN handling. 123 * 124 * XXX when we decide to support more than one rule type, we should 125 * repeat the hashing multiple times uing only the useful fields. 126 * Or, we could run the various tests in parallel, because the 127 * 'move to front' technique should shorten the average search. 128 * 129 * The lifetime of dynamic rules is regulated by dyn_*_lifetime, 130 * measured in seconds and depending on the flags. 131 * 132 * The total number of dynamic rules is stored in dyn_count. 133 * The max number of dynamic rules is dyn_max. When we reach 134 * the maximum number of rules we do not create anymore. This is 135 * done to avoid consuming too much memory, but also too much 136 * time when searching on each packet (ideally, we should try instead 137 * to put a limit on the length of the list on each bucket...). 138 * 139 * Each dynamic rules holds a pointer to the parent ipfw rule so 140 * we know what action to perform. Dynamic rules are removed when 141 * the parent rule is deleted. 142 * There are some limitations with dynamic rules -- we do not 143 * obey the 'randomized match', and we do not do multiple 144 * passes through the firewall. 145 * XXX check the latter!!! 146 */ 147 static struct ipfw_dyn_rule **ipfw_dyn_v = NULL ; 148 static u_int32_t dyn_buckets = 256 ; /* must be power of 2 */ 149 static u_int32_t curr_dyn_buckets = 256 ; /* must be power of 2 */ 150 static u_int32_t dyn_ack_lifetime = 300 ; 151 static u_int32_t dyn_syn_lifetime = 20 ; 152 static u_int32_t dyn_fin_lifetime = 20 ; 153 static u_int32_t dyn_rst_lifetime = 5 ; 154 static u_int32_t dyn_short_lifetime = 30 ; 155 static u_int32_t dyn_count = 0 ; 156 static u_int32_t dyn_max = 1000 ; 157 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLFLAG_RW, 158 &dyn_buckets, 0, "Number of dyn. buckets"); 159 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_RD, 160 &curr_dyn_buckets, 0, "Current Number of dyn. buckets"); 161 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_RD, 162 &dyn_count, 0, "Number of dyn. rules"); 163 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_RW, 164 &dyn_max, 0, "Max number of dyn. rules"); 165 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_RW, 166 &dyn_ack_lifetime, 0, "Lifetime of dyn. rules for acks"); 167 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_RW, 168 &dyn_syn_lifetime, 0, "Lifetime of dyn. rules for syn"); 169 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, CTLFLAG_RW, 170 &dyn_fin_lifetime, 0, "Lifetime of dyn. rules for fin"); 171 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, CTLFLAG_RW, 172 &dyn_rst_lifetime, 0, "Lifetime of dyn. rules for rst"); 173 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_RW, 174 &dyn_rst_lifetime, 0, "Lifetime of dyn. rules for other situations"); 175 #endif /* STATEFUL */ 176 177 #endif 178 179 #define dprintf(a) if (!fw_debug); else printf a 180 181 #define print_ip(a) printf("%d.%d.%d.%d", \ 182 (int)(ntohl(a.s_addr) >> 24) & 0xFF, \ 183 (int)(ntohl(a.s_addr) >> 16) & 0xFF, \ 184 (int)(ntohl(a.s_addr) >> 8) & 0xFF, \ 185 (int)(ntohl(a.s_addr)) & 0xFF); 186 187 #define dprint_ip(a) if (!fw_debug); else print_ip(a) 188 189 static int add_entry __P((struct ip_fw_head *chainptr, struct ip_fw *frwl)); 190 static int del_entry __P((struct ip_fw_head *chainptr, u_short number)); 191 static int zero_entry __P((struct ip_fw *)); 192 static int resetlog_entry __P((struct ip_fw *)); 193 static int check_ipfw_struct __P((struct ip_fw *m)); 194 static __inline int 195 iface_match __P((struct ifnet *ifp, union ip_fw_if *ifu, 196 int byname)); 197 static int ipopts_match __P((struct ip *ip, struct ip_fw *f)); 198 static __inline int 199 port_match __P((u_short *portptr, int nports, u_short port, 200 int range_flag, int mask)); 201 static int tcpflg_match __P((struct tcphdr *tcp, struct ip_fw *f)); 202 static int icmptype_match __P((struct icmp * icmp, struct ip_fw * f)); 203 static void ipfw_report __P((struct ip_fw *f, struct ip *ip, 204 struct ifnet *rif, struct ifnet *oif)); 205 206 static void flush_rule_ptrs(void); 207 208 static int ip_fw_chk __P((struct ip **pip, int hlen, 209 struct ifnet *oif, u_int16_t *cookie, struct mbuf **m, 210 struct ip_fw_chain **flow_id, 211 struct sockaddr_in **next_hop)); 212 static int ip_fw_ctl __P((struct sockopt *sopt)); 213 214 static char err_prefix[] = "ip_fw_ctl:"; 215 216 /* 217 * Returns 1 if the port is matched by the vector, 0 otherwise 218 */ 219 static __inline int 220 port_match(u_short *portptr, int nports, u_short port, int range_flag, int mask) 221 { 222 if (!nports) 223 return 1; 224 if (mask) { 225 if ( 0 == ((portptr[0] ^ port) & portptr[1]) ) 226 return 1; 227 nports -= 2; 228 portptr += 2; 229 } 230 if (range_flag) { 231 if (portptr[0] <= port && port <= portptr[1]) { 232 return 1; 233 } 234 nports -= 2; 235 portptr += 2; 236 } 237 while (nports-- > 0) { 238 if (*portptr++ == port) { 239 return 1; 240 } 241 } 242 return 0; 243 } 244 245 static int 246 tcpflg_match(struct tcphdr *tcp, struct ip_fw *f) 247 { 248 u_char flg_set, flg_clr; 249 250 /* 251 * If an established connection is required, reject packets that 252 * have only SYN of RST|ACK|SYN set. Otherwise, fall through to 253 * other flag requirements. 254 */ 255 if ((f->fw_ipflg & IP_FW_IF_TCPEST) && 256 ((tcp->th_flags & (IP_FW_TCPF_RST | IP_FW_TCPF_ACK | 257 IP_FW_TCPF_SYN)) == IP_FW_TCPF_SYN)) 258 return 0; 259 260 flg_set = tcp->th_flags & f->fw_tcpf; 261 flg_clr = tcp->th_flags & f->fw_tcpnf; 262 263 if (flg_set != f->fw_tcpf) 264 return 0; 265 if (flg_clr) 266 return 0; 267 268 return 1; 269 } 270 271 static int 272 icmptype_match(struct icmp *icmp, struct ip_fw *f) 273 { 274 int type; 275 276 if (!(f->fw_flg & IP_FW_F_ICMPBIT)) 277 return(1); 278 279 type = icmp->icmp_type; 280 281 /* check for matching type in the bitmap */ 282 if (type < IP_FW_ICMPTYPES_MAX && 283 (f->fw_uar.fw_icmptypes[type / (sizeof(unsigned) * 8)] & 284 (1U << (type % (8 * sizeof(unsigned)))))) 285 return(1); 286 287 return(0); /* no match */ 288 } 289 290 static int 291 is_icmp_query(struct ip *ip) 292 { 293 const struct icmp *icmp; 294 int icmp_type; 295 296 icmp = (struct icmp *)((u_int32_t *)ip + ip->ip_hl); 297 icmp_type = icmp->icmp_type; 298 299 if (icmp_type == ICMP_ECHO || icmp_type == ICMP_ROUTERSOLICIT || 300 icmp_type == ICMP_TSTAMP || icmp_type == ICMP_IREQ || 301 icmp_type == ICMP_MASKREQ) 302 return(1); 303 304 return(0); 305 } 306 307 static int 308 ipopts_match(struct ip *ip, struct ip_fw *f) 309 { 310 register u_char *cp; 311 int opt, optlen, cnt; 312 u_char opts, nopts, nopts_sve; 313 314 cp = (u_char *)(ip + 1); 315 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 316 opts = f->fw_ipopt; 317 nopts = nopts_sve = f->fw_ipnopt; 318 319 for (; cnt > 0; cnt -= optlen, cp += optlen) { 320 opt = cp[IPOPT_OPTVAL]; 321 if (opt == IPOPT_EOL) 322 break; 323 if (opt == IPOPT_NOP) 324 optlen = 1; 325 else { 326 optlen = cp[IPOPT_OLEN]; 327 if (optlen <= 0 || optlen > cnt) { 328 return 0; /*XXX*/ 329 } 330 } 331 switch (opt) { 332 333 default: 334 break; 335 336 case IPOPT_LSRR: 337 opts &= ~IP_FW_IPOPT_LSRR; 338 nopts &= ~IP_FW_IPOPT_LSRR; 339 break; 340 341 case IPOPT_SSRR: 342 opts &= ~IP_FW_IPOPT_SSRR; 343 nopts &= ~IP_FW_IPOPT_SSRR; 344 break; 345 346 case IPOPT_RR: 347 opts &= ~IP_FW_IPOPT_RR; 348 nopts &= ~IP_FW_IPOPT_RR; 349 break; 350 case IPOPT_TS: 351 opts &= ~IP_FW_IPOPT_TS; 352 nopts &= ~IP_FW_IPOPT_TS; 353 break; 354 } 355 if (opts == nopts) 356 break; 357 } 358 if (opts == 0 && nopts == nopts_sve) 359 return 1; 360 else 361 return 0; 362 } 363 364 static __inline int 365 iface_match(struct ifnet *ifp, union ip_fw_if *ifu, int byname) 366 { 367 /* Check by name or by IP address */ 368 if (byname) { 369 /* Check unit number (-1 is wildcard) */ 370 if (ifu->fu_via_if.unit != -1 371 && ifp->if_unit != ifu->fu_via_if.unit) 372 return(0); 373 /* Check name */ 374 if (strncmp(ifp->if_name, ifu->fu_via_if.name, FW_IFNLEN)) 375 return(0); 376 return(1); 377 } else if (ifu->fu_via_ip.s_addr != 0) { /* Zero == wildcard */ 378 struct ifaddr *ia; 379 380 for (ia = ifp->if_addrhead.tqh_first; 381 ia != NULL; ia = ia->ifa_link.tqe_next) { 382 if (ia->ifa_addr == NULL) 383 continue; 384 if (ia->ifa_addr->sa_family != AF_INET) 385 continue; 386 if (ifu->fu_via_ip.s_addr != ((struct sockaddr_in *) 387 (ia->ifa_addr))->sin_addr.s_addr) 388 continue; 389 return(1); 390 } 391 return(0); 392 } 393 return(1); 394 } 395 396 static void 397 ipfw_report(struct ip_fw *f, struct ip *ip, 398 struct ifnet *rif, struct ifnet *oif) 399 { 400 if (ip) { 401 struct tcphdr *const tcp = (struct tcphdr *) ((u_int32_t *) ip+ ip->ip_hl); 402 struct udphdr *const udp = (struct udphdr *) ((u_int32_t *) ip+ ip->ip_hl); 403 struct icmp *const icmp = (struct icmp *) ((u_int32_t *) ip + ip->ip_hl); 404 u_int64_t count; 405 406 count = f ? f->fw_pcnt : ++counter; 407 if ((f == NULL && fw_verbose_limit != 0 && count > fw_verbose_limit) || 408 (f && f->fw_logamount != 0 && count > f->fw_loghighest)) 409 return; 410 411 /* Print command name */ 412 printf("ipfw: %d ", f ? f->fw_number : -1); 413 if (!f) 414 printf("Refuse"); 415 else 416 switch (f->fw_flg & IP_FW_F_COMMAND) { 417 case IP_FW_F_DENY: 418 printf("Deny"); 419 break; 420 case IP_FW_F_REJECT: 421 if (f->fw_reject_code == IP_FW_REJECT_RST) 422 printf("Reset"); 423 else 424 printf("Unreach"); 425 break; 426 case IP_FW_F_ACCEPT: 427 printf("Accept"); 428 break; 429 case IP_FW_F_COUNT: 430 printf("Count"); 431 break; 432 #ifdef IPDIVERT 433 case IP_FW_F_DIVERT: 434 printf("Divert %d", f->fw_divert_port); 435 break; 436 case IP_FW_F_TEE: 437 printf("Tee %d", f->fw_divert_port); 438 break; 439 #endif 440 case IP_FW_F_SKIPTO: 441 printf("SkipTo %d", f->fw_skipto_rule); 442 break; 443 #ifdef DUMMYNET 444 case IP_FW_F_PIPE: 445 printf("Pipe %d", f->fw_skipto_rule); 446 break; 447 #endif 448 #ifdef IPFIREWALL_FORWARD 449 case IP_FW_F_FWD: 450 printf("Forward to "); 451 print_ip(f->fw_fwd_ip.sin_addr); 452 if (f->fw_fwd_ip.sin_port) 453 printf(":%d", f->fw_fwd_ip.sin_port); 454 break; 455 #endif 456 default: 457 printf("UNKNOWN"); 458 break; 459 } 460 printf(" "); 461 462 switch (ip->ip_p) { 463 case IPPROTO_TCP: 464 printf("TCP "); 465 print_ip(ip->ip_src); 466 if ((ip->ip_off & IP_OFFMASK) == 0) 467 printf(":%d ", ntohs(tcp->th_sport)); 468 else 469 printf(" "); 470 print_ip(ip->ip_dst); 471 if ((ip->ip_off & IP_OFFMASK) == 0) 472 printf(":%d", ntohs(tcp->th_dport)); 473 break; 474 case IPPROTO_UDP: 475 printf("UDP "); 476 print_ip(ip->ip_src); 477 if ((ip->ip_off & IP_OFFMASK) == 0) 478 printf(":%d ", ntohs(udp->uh_sport)); 479 else 480 printf(" "); 481 print_ip(ip->ip_dst); 482 if ((ip->ip_off & IP_OFFMASK) == 0) 483 printf(":%d", ntohs(udp->uh_dport)); 484 break; 485 case IPPROTO_ICMP: 486 if ((ip->ip_off & IP_OFFMASK) == 0) 487 printf("ICMP:%u.%u ", icmp->icmp_type, icmp->icmp_code); 488 else 489 printf("ICMP "); 490 print_ip(ip->ip_src); 491 printf(" "); 492 print_ip(ip->ip_dst); 493 break; 494 default: 495 printf("P:%d ", ip->ip_p); 496 print_ip(ip->ip_src); 497 printf(" "); 498 print_ip(ip->ip_dst); 499 break; 500 } 501 if (oif) 502 printf(" out via %s%d", oif->if_name, oif->if_unit); 503 else if (rif) 504 printf(" in via %s%d", rif->if_name, rif->if_unit); 505 if ((ip->ip_off & IP_OFFMASK)) 506 printf(" Fragment = %d",ip->ip_off & IP_OFFMASK); 507 printf("\n"); 508 if ((f ? f->fw_logamount != 0 : 1) && 509 count == (f ? f->fw_loghighest : fw_verbose_limit)) 510 printf("ipfw: limit %d reached on rule #%d\n", 511 f ? f->fw_logamount : fw_verbose_limit, 512 f ? f->fw_number : -1); 513 } 514 } 515 516 #if STATEFUL 517 static __inline int 518 hash_packet(struct ipfw_flow_id *id) 519 { 520 u_int32_t i ; 521 522 i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port); 523 i &= (curr_dyn_buckets - 1) ; 524 return i ; 525 } 526 527 #define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0) 528 /* 529 * Remove all dynamic rules pointing to a given chain, or all 530 * rules if chain == NULL. Second parameter is 1 if we want to 531 * delete unconditionally, otherwise only expired rules are removed. 532 */ 533 static void 534 remove_dyn_rule(struct ip_fw_chain *chain, int force) 535 { 536 struct ipfw_dyn_rule *prev, *q, *old_q ; 537 int i ; 538 static u_int32_t last_remove = 0 ; 539 540 if (ipfw_dyn_v == NULL || dyn_count == 0) 541 return ; 542 /* do not expire more than once per second, it is useless */ 543 if (force == 0 && last_remove == time_second) 544 return ; 545 last_remove = time_second ; 546 547 for (i = 0 ; i < curr_dyn_buckets ; i++) { 548 for (prev=NULL, q = ipfw_dyn_v[i] ; q ; ) { 549 if ( (chain == NULL || chain == q->chain) && 550 (force || TIME_LEQ( q->expire , time_second ) ) ) { 551 DEB(printf("-- remove entry 0x%08x %d -> 0x%08x %d, %d left\n", 552 (q->id.src_ip), (q->id.src_port), 553 (q->id.dst_ip), (q->id.dst_port), dyn_count-1 ); ) 554 old_q = q ; 555 if (prev != NULL) 556 prev->next = q = q->next ; 557 else 558 ipfw_dyn_v[i] = q = q->next ; 559 dyn_count-- ; 560 free(old_q, M_IPFW); 561 continue ; 562 } else { 563 prev = q ; 564 q = q->next ; 565 } 566 } 567 } 568 } 569 570 static struct ipfw_dyn_rule * 571 lookup_dyn_rule(struct ipfw_flow_id *pkt) 572 { 573 /* 574 * stateful ipfw extensions. 575 * Lookup into dynamic session queue 576 */ 577 struct ipfw_dyn_rule *prev, *q, *old_q ; 578 int i, dir = 0; 579 #define MATCH_FORWARD 1 580 581 if (ipfw_dyn_v == NULL) 582 return NULL ; 583 i = hash_packet( pkt ); 584 for (prev=NULL, q = ipfw_dyn_v[i] ; q != NULL ; ) { 585 switch (q->type) { 586 default: /* bidirectional rule, no masks */ 587 if ( pkt->proto == q->id.proto) { 588 if (pkt->src_ip == q->id.src_ip && 589 pkt->dst_ip == q->id.dst_ip && 590 pkt->src_port == q->id.src_port && 591 pkt->dst_port == q->id.dst_port ) { 592 dir = MATCH_FORWARD ; 593 goto found ; 594 } 595 if (pkt->src_ip == q->id.dst_ip && 596 pkt->dst_ip == q->id.src_ip && 597 pkt->src_port == q->id.dst_port && 598 pkt->dst_port == q->id.src_port ) { 599 dir = 0 ; 600 goto found ; 601 } 602 } 603 break ; 604 } 605 if (TIME_LEQ( q->expire , time_second ) ) { 606 /* expire entry */ 607 old_q = q ; 608 if (prev != NULL) 609 prev->next = q = q->next ; 610 else 611 ipfw_dyn_v[i] = q = q->next ; 612 dyn_count-- ; 613 free(old_q, M_IPFW); 614 continue ; 615 } else { 616 prev = q ; 617 q = q->next ; 618 } 619 } 620 return NULL ; /* clearly not found */ 621 found: 622 if (q != NULL) { /* redundant check! */ 623 if ( prev != NULL) { /* found and not in front */ 624 prev->next = q->next ; 625 q->next = ipfw_dyn_v[i] ; 626 ipfw_dyn_v[i] = q ; 627 } 628 if (pkt->proto == IPPROTO_TCP) { 629 /* update state according to flags */ 630 u_char flags = pkt->flags & (TH_FIN|TH_SYN|TH_RST); 631 q->state |= (dir == MATCH_FORWARD ) ? flags : (flags << 8); 632 switch (q->state) { 633 case TH_SYN : 634 /* opening */ 635 q->expire = time_second + dyn_syn_lifetime ; 636 break ; 637 case TH_SYN | (TH_SYN << 8) : 638 /* move to established */ 639 q->expire = time_second + dyn_ack_lifetime ; 640 break ; 641 case TH_SYN | (TH_SYN << 8) | TH_FIN : 642 case TH_SYN | (TH_SYN << 8) | (TH_FIN << 8) : 643 /* one side tries to close */ 644 q->expire = time_second + dyn_fin_lifetime ; 645 break ; 646 case TH_SYN | (TH_SYN << 8) | TH_FIN | (TH_FIN << 8) : 647 /* both sides closed */ 648 q->expire = time_second + dyn_fin_lifetime ; 649 break ; 650 default: 651 #if 0 652 /* reset or some invalid combination, but can also 653 * occur if we use keep-state the wrong way. 654 */ 655 if ( (q->state & ((TH_RST << 8)|TH_RST)) == 0) 656 printf("invalid state: 0x%x\n", q->state); 657 #endif 658 q->expire = time_second + dyn_rst_lifetime ; 659 break ; 660 } 661 } else { 662 /* should do something for UDP and others... */ 663 q->expire = time_second + dyn_short_lifetime ; 664 } 665 } 666 return q ; 667 } 668 669 /* 670 * Install state for a dynamic session. 671 */ 672 673 static void 674 add_dyn_rule(struct ipfw_flow_id *id, struct ipfw_flow_id *mask, 675 struct ip_fw_chain *chain) 676 { 677 struct ipfw_dyn_rule *r ; 678 679 int i ; 680 if (ipfw_dyn_v == NULL || 681 (dyn_count == 0 && dyn_buckets != curr_dyn_buckets)) { 682 /* try reallocation, make sure we have a power of 2 */ 683 u_int32_t i = dyn_buckets ; 684 while ( i > 0 && (i & 1) == 0 ) 685 i >>= 1 ; 686 if (i != 1) /* not a power of 2 */ 687 dyn_buckets = curr_dyn_buckets ; /* reset */ 688 else { 689 if (ipfw_dyn_v != NULL) 690 free(ipfw_dyn_v, M_IPFW); 691 ipfw_dyn_v = malloc(curr_dyn_buckets * sizeof r, 692 M_IPFW, M_DONTWAIT); 693 if (ipfw_dyn_v == NULL) 694 return ; /* failed ! */ 695 bzero(ipfw_dyn_v, curr_dyn_buckets * sizeof r); 696 } 697 } 698 i = hash_packet(id); 699 700 r = malloc(sizeof *r, M_IPFW, M_DONTWAIT); 701 if (r == NULL) { 702 printf ("sorry cannot allocate state\n"); 703 return ; 704 } 705 bzero (r, sizeof (*r) ); 706 707 if (mask) 708 r->mask = *mask ; 709 r->id = *id ; 710 r->expire = time_second + dyn_syn_lifetime ; 711 r->chain = chain ; 712 r->type = ((struct ip_fw_ext *)chain->rule)->dyn_type ; 713 714 r->bucket = i ; 715 r->next = ipfw_dyn_v[i] ; 716 ipfw_dyn_v[i] = r ; 717 dyn_count++ ; 718 DEB(printf("-- add entry 0x%08x %d -> 0x%08x %d, %d left\n", 719 (r->id.src_ip), (r->id.src_port), 720 (r->id.dst_ip), (r->id.dst_port), 721 dyn_count ); ) 722 } 723 724 /* 725 * Install dynamic state. 726 * There are different types of dynamic rules which can be installed. 727 * The type is in chain->dyn_type. 728 * Type 0 (default) is a bidirectional rule 729 */ 730 static void 731 install_state(struct ip_fw_chain *chain, struct ip **pip, struct ip *ip) 732 { 733 struct ipfw_dyn_rule *q ; 734 static int last_log ; 735 736 u_long type = ((struct ip_fw_ext *)chain->rule)->dyn_type ; 737 738 DEB(printf("-- install state type %d 0x%08lx %u -> 0x%08lx %u\n", 739 type, 740 (last_pkt.src_ip), (last_pkt.src_port), 741 (last_pkt.dst_ip), (last_pkt.dst_port) );) 742 743 q = lookup_dyn_rule(&last_pkt) ; 744 if (q != NULL) { 745 if (last_log == time_second) 746 return ; 747 last_log = time_second ; 748 printf(" entry already present, done\n"); 749 return ; 750 } 751 if (dyn_count >= dyn_max) /* try remove old ones... */ 752 remove_dyn_rule(NULL, 0 /* expire */); 753 if (dyn_count >= dyn_max) { 754 if (last_log == time_second) 755 return ; 756 last_log = time_second ; 757 printf(" Too many dynamic rules, sorry\n"); 758 return ; 759 } 760 switch (type) { 761 default: /* bidir rule */ 762 add_dyn_rule(&last_pkt, NULL, chain); 763 break ; 764 } 765 q = lookup_dyn_rule(&last_pkt) ; /* XXX this just sets the lifetime ... */ 766 } 767 #endif /* STATEFUL */ 768 769 /* 770 * given an ip_fw_chain *, lookup_next_rule will return a pointer 771 * of the same type to the next one. This can be either the jump 772 * target (for skipto instructions) or the next one in the chain (in 773 * all other cases including a missing jump target). 774 * Backward jumps are not allowed, so start looking from the next 775 * rule... 776 */ 777 static struct ip_fw_chain * lookup_next_rule(struct ip_fw_chain *me); 778 779 static struct ip_fw_chain * 780 lookup_next_rule(struct ip_fw_chain *me) 781 { 782 struct ip_fw_chain *chain ; 783 int rule = me->rule->fw_skipto_rule ; /* guess... */ 784 785 if ( (me->rule->fw_flg & IP_FW_F_COMMAND) == IP_FW_F_SKIPTO ) 786 for (chain = me->chain.le_next; chain ; chain = chain->chain.le_next ) 787 if (chain->rule->fw_number >= rule) 788 return chain ; 789 return me->chain.le_next ; /* failure or not a skipto */ 790 } 791 792 /* 793 * Parameters: 794 * 795 * pip Pointer to packet header (struct ip **) 796 * bridge_ipfw extension: pip = NULL means a complete ethernet packet 797 * including ethernet header in the mbuf. Other fields 798 * are ignored/invalid. 799 * 800 * hlen Packet header length 801 * oif Outgoing interface, or NULL if packet is incoming 802 * *cookie Skip up to the first rule past this rule number; 803 * upon return, non-zero port number for divert or tee 804 * *m The packet; we set to NULL when/if we nuke it. 805 * *flow_id pointer to the last matching rule (in/out) 806 * *next_hop socket we are forwarding to (in/out). 807 * 808 * Return value: 809 * 810 * 0 The packet is to be accepted and routed normally OR 811 * the packet was denied/rejected and has been dropped; 812 * in the latter case, *m is equal to NULL upon return. 813 * port Divert the packet to port, with these caveats: 814 * 815 * - If IP_FW_PORT_TEE_FLAG is set, tee the packet instead 816 * of diverting it (ie, 'ipfw tee'). 817 * 818 * - If IP_FW_PORT_DYNT_FLAG is set, interpret the lower 819 * 16 bits as a dummynet pipe number instead of diverting 820 */ 821 822 static int 823 ip_fw_chk(struct ip **pip, int hlen, 824 struct ifnet *oif, u_int16_t *cookie, struct mbuf **m, 825 struct ip_fw_chain **flow_id, 826 struct sockaddr_in **next_hop) 827 { 828 struct ip_fw_chain *chain; 829 struct ip_fw *f = NULL, *rule = NULL; 830 struct ip *ip = NULL ; 831 struct ifnet *const rif = (*m)->m_pkthdr.rcvif; 832 u_short offset = 0 ; 833 u_short src_port = 0, dst_port = 0; 834 struct in_addr src_ip, dst_ip; /* XXX */ 835 u_int8_t proto= 0, flags = 0 ; /* XXX */ 836 u_int16_t skipto ; 837 838 #if STATEFUL 839 int dyn_checked = 0 ; /* set after dyn.rules have been checked. */ 840 struct ipfw_dyn_rule *q = NULL ; 841 #endif 842 /* Grab and reset cookie */ 843 skipto = *cookie; 844 *cookie = 0; 845 846 /* 847 * here, pip==NULL for bridged pkts -- they include the ethernet 848 * header so i have to adjust lengths accordingly 849 */ 850 #define PULLUP_TO(l) do { \ 851 int len = (pip ? (l) : (l) + 14 ) ; \ 852 if ((*m)->m_len < (len) ) { \ 853 if ( (*m = m_pullup(*m, (len))) == 0) \ 854 goto bogusfrag; \ 855 ip = mtod(*m, struct ip *); \ 856 if (pip) \ 857 *pip = ip ; \ 858 else \ 859 ip = (struct ip *)((char *)ip + 14);\ 860 offset = (ip->ip_off & IP_OFFMASK); \ 861 } \ 862 } while (0) 863 864 if (pip) { /* normal ip packet */ 865 ip = *pip; 866 offset = (ip->ip_off & IP_OFFMASK); 867 } else { /* bridged or non-ip packet */ 868 struct ether_header *eh = mtod(*m, struct ether_header *); 869 switch (ntohs(eh->ether_type)) { 870 case ETHERTYPE_IP : 871 if ((*m)->m_len<sizeof(struct ether_header) + sizeof(struct ip)) 872 goto non_ip ; 873 ip = (struct ip *)(eh + 1 ); 874 if (ip->ip_v != IPVERSION) 875 goto non_ip ; 876 hlen = ip->ip_hl << 2; 877 if (hlen < sizeof(struct ip)) /* minimum header length */ 878 goto non_ip ; 879 if ((*m)->m_len < 14 + hlen + 14) { 880 printf("-- m_len %d, need more...\n", (*m)->m_len); 881 goto non_ip ; 882 } 883 offset = (ip->ip_off & IP_OFFMASK); 884 break ; 885 default : 886 non_ip: ip = NULL ; 887 break ; 888 } 889 } 890 891 /* 892 * collect parameters into local variables for faster matching. 893 */ 894 if (ip) { 895 struct tcphdr *tcp; 896 struct udphdr *udp; 897 898 dst_ip = ip->ip_dst ; 899 src_ip = ip->ip_src ; 900 proto = ip->ip_p ; 901 /* 902 * warning - if offset != 0, port values are bogus. 903 * Not a problem for ipfw, but could be for dummynet. 904 */ 905 switch (proto) { 906 case IPPROTO_TCP : 907 PULLUP_TO(hlen + 14); 908 tcp =(struct tcphdr *)((u_int32_t *)ip + ip->ip_hl); 909 dst_port = tcp->th_dport ; 910 src_port = tcp->th_sport ; 911 flags = tcp->th_flags ; 912 break ; 913 914 case IPPROTO_UDP : 915 PULLUP_TO(hlen + 4); 916 udp =(struct udphdr *)((u_int32_t *)ip + ip->ip_hl); 917 dst_port = udp->uh_dport ; 918 src_port = udp->uh_sport ; 919 break ; 920 921 case IPPROTO_ICMP: 922 PULLUP_TO(hlen + 2); 923 flags = ((struct icmp *) 924 ((u_int32_t *)ip + ip->ip_hl))->icmp_type ; 925 break ; 926 927 default : 928 src_port = dst_port = 0 ; 929 } 930 #undef PULLUP_TO 931 last_pkt.src_ip = ntohl(src_ip.s_addr) ; 932 last_pkt.dst_ip = ntohl(dst_ip.s_addr) ; 933 last_pkt.proto = proto ; 934 last_pkt.src_port = ntohs(src_port) ; 935 last_pkt.dst_port = ntohs(dst_port) ; 936 last_pkt.flags = flags ; 937 } 938 939 if (*flow_id) { 940 /* Accept if passed first test */ 941 if (fw_one_pass) 942 return 0 ; 943 /* 944 * Packet has already been tagged. Look for the next rule 945 * to restart processing. 946 */ 947 chain = LIST_NEXT( *flow_id, chain); 948 949 if ( (chain = (*flow_id)->rule->next_rule_ptr) == NULL ) 950 chain = (*flow_id)->rule->next_rule_ptr = 951 lookup_next_rule(*flow_id) ; 952 if (chain == NULL) 953 goto dropit; 954 } else { 955 /* 956 * Go down the chain, looking for enlightment. 957 * If we've been asked to start at a given rule, do so. 958 */ 959 chain = LIST_FIRST(&ip_fw_chain); 960 if ( skipto != 0 ) { 961 if (skipto >= IPFW_DEFAULT_RULE) 962 goto dropit; 963 while (chain && chain->rule->fw_number <= skipto) 964 chain = LIST_NEXT(chain, chain); 965 if ( chain == NULL ) 966 goto dropit; 967 } 968 } 969 970 971 for (; chain; chain = LIST_NEXT(chain, chain)) { 972 again: 973 f = chain->rule; 974 if (f->fw_number == IPFW_DEFAULT_RULE) 975 goto got_match ; 976 977 #if STATEFUL 978 /* 979 * dynamic rules are checked at the first keep-state or 980 * check-state occurrence. 981 */ 982 if (f->fw_flg & (IP_FW_F_KEEP_S|IP_FW_F_CHECK_S) && 983 dyn_checked == 0 ) { 984 dyn_checked = 1 ; 985 if (ip) 986 q = lookup_dyn_rule(&last_pkt); 987 if (q != NULL) { 988 DEB(printf("-- dynamic match 0x%08x %d -> 0x%08x %d\n", 989 (q->id.src_ip), (q->id.src_port), 990 (q->id.dst_ip), (q->id.dst_port) ); ) 991 chain = q->chain ; 992 q->pcnt++ ; 993 if (ip) 994 q->bcnt += ip->ip_len; 995 goto got_match ; /* random not allowed here */ 996 } 997 /* if this was a check-only rule, continue with next */ 998 if (f->fw_flg & IP_FW_F_CHECK_S) 999 continue ; 1000 } 1001 #endif /* stateful ipfw */ 1002 /* 1003 * Rule only valid for bridged packets, skip if this 1004 * is not one of those (pip != NULL) 1005 */ 1006 if (pip != NULL && f->fw_flg & IP_FW_BRIDGED ) 1007 continue ; 1008 1009 if (oif) { 1010 /* Check direction outbound */ 1011 if (!(f->fw_flg & IP_FW_F_OUT)) 1012 continue; 1013 } else { 1014 /* Check direction inbound */ 1015 if (!(f->fw_flg & IP_FW_F_IN)) 1016 continue; 1017 } 1018 if (ip == NULL ) { 1019 /* 1020 * do relevant checks for non-ip packets: 1021 * after this, only goto got_match or continue 1022 */ 1023 struct ether_header *eh = mtod(*m, struct ether_header *); 1024 /* 1025 * temporary hack: 1026 * udp from 0.0.0.0 means this rule applies. 1027 * 1 src port is match ether type 1028 * 2 src ports (interval) is match ether type 1029 * 3 src ports is match ether address 1030 */ 1031 if ( f->fw_src.s_addr != 0 || f->fw_prot != IPPROTO_UDP 1032 || f->fw_smsk.s_addr != 0xffffffff ) 1033 continue; 1034 switch (IP_FW_GETNSRCP(f)) { 1035 case 1: /* match one type */ 1036 if ( /* ( (f->fw_flg & IP_FW_F_INVSRC) != 0) ^ */ 1037 ( f->fw_uar.fw_pts[0] == ntohs(eh->ether_type) ) ) { 1038 goto got_match ; 1039 } 1040 break ; 1041 default: 1042 break ; 1043 } 1044 continue ; 1045 } 1046 1047 /* Fragments */ 1048 if ((f->fw_flg & IP_FW_F_FRAG) && offset == 0 ) 1049 continue; 1050 1051 /* If src-addr doesn't match, not this rule. */ 1052 if (((f->fw_flg & IP_FW_F_INVSRC) != 0) ^ ((src_ip.s_addr 1053 & f->fw_smsk.s_addr) != f->fw_src.s_addr)) 1054 continue; 1055 1056 /* If dest-addr doesn't match, not this rule. */ 1057 if (((f->fw_flg & IP_FW_F_INVDST) != 0) ^ ((dst_ip.s_addr 1058 & f->fw_dmsk.s_addr) != f->fw_dst.s_addr)) 1059 continue; 1060 1061 /* Interface check */ 1062 if ((f->fw_flg & IF_FW_F_VIAHACK) == IF_FW_F_VIAHACK) { 1063 struct ifnet *const iface = oif ? oif : rif; 1064 1065 /* Backwards compatibility hack for "via" */ 1066 if (!iface || !iface_match(iface, 1067 &f->fw_in_if, f->fw_flg & IP_FW_F_OIFNAME)) 1068 continue; 1069 } else { 1070 /* Check receive interface */ 1071 if ((f->fw_flg & IP_FW_F_IIFACE) 1072 && (!rif || !iface_match(rif, 1073 &f->fw_in_if, f->fw_flg & IP_FW_F_IIFNAME))) 1074 continue; 1075 /* Check outgoing interface */ 1076 if ((f->fw_flg & IP_FW_F_OIFACE) 1077 && (!oif || !iface_match(oif, 1078 &f->fw_out_if, f->fw_flg & IP_FW_F_OIFNAME))) 1079 continue; 1080 } 1081 1082 /* Check IP options */ 1083 if (f->fw_ipopt != f->fw_ipnopt && !ipopts_match(ip, f)) 1084 continue; 1085 1086 /* Check protocol; if wildcard, and no [ug]id, match */ 1087 if (f->fw_prot == IPPROTO_IP) { 1088 if (!(f->fw_flg & (IP_FW_F_UID|IP_FW_F_GID))) 1089 goto rnd_then_got_match; 1090 } else 1091 /* If different, don't match */ 1092 if (proto != f->fw_prot) 1093 continue; 1094 1095 /* Protocol specific checks for uid only */ 1096 if (f->fw_flg & (IP_FW_F_UID|IP_FW_F_GID)) { 1097 switch (proto) { 1098 case IPPROTO_TCP: 1099 { 1100 struct inpcb *P; 1101 1102 if (offset == 1) /* cf. RFC 1858 */ 1103 goto bogusfrag; 1104 if (offset != 0) 1105 continue; 1106 1107 if (oif) 1108 P = in_pcblookup_hash(&tcbinfo, dst_ip, 1109 dst_port, src_ip, src_port, 0); 1110 else 1111 P = in_pcblookup_hash(&tcbinfo, src_ip, 1112 src_port, dst_ip, dst_port, 0); 1113 1114 if (P && P->inp_socket && P->inp_socket->so_cred) { 1115 if (f->fw_flg & IP_FW_F_UID) { 1116 if (P->inp_socket->so_cred->p_ruid != 1117 f->fw_uid) 1118 continue; 1119 } else if (!groupmember(f->fw_gid, 1120 P->inp_socket->so_cred->pc_ucred)) 1121 continue; 1122 } else continue; 1123 1124 break; 1125 } 1126 1127 case IPPROTO_UDP: 1128 { 1129 struct inpcb *P; 1130 1131 if (offset != 0) 1132 continue; 1133 1134 if (oif) 1135 P = in_pcblookup_hash(&udbinfo, dst_ip, 1136 dst_port, src_ip, src_port, 1); 1137 else 1138 P = in_pcblookup_hash(&udbinfo, src_ip, 1139 src_port, dst_ip, dst_port, 1); 1140 1141 if (P && P->inp_socket && P->inp_socket->so_cred) { 1142 if (f->fw_flg & IP_FW_F_UID) { 1143 if (P->inp_socket->so_cred->p_ruid != 1144 f->fw_uid) 1145 continue; 1146 } else if (!groupmember(f->fw_gid, 1147 P->inp_socket->so_cred->pc_ucred)) 1148 continue; 1149 } else continue; 1150 1151 break; 1152 } 1153 1154 default: 1155 continue; 1156 } 1157 } 1158 1159 /* Protocol specific checks */ 1160 switch (proto) { 1161 case IPPROTO_TCP: 1162 { 1163 struct tcphdr *tcp; 1164 1165 if (offset == 1) /* cf. RFC 1858 */ 1166 goto bogusfrag; 1167 if (offset != 0) { 1168 /* 1169 * TCP flags and ports aren't available in this 1170 * packet -- if this rule specified either one, 1171 * we consider the rule a non-match. 1172 */ 1173 if (f->fw_nports != 0 || 1174 f->fw_tcpf != f->fw_tcpnf) 1175 continue; 1176 1177 break; 1178 } 1179 tcp = (struct tcphdr *) ((u_int32_t *)ip + ip->ip_hl); 1180 if (((f->fw_tcpf != f->fw_tcpnf) || 1181 (f->fw_ipflg & IP_FW_IF_TCPEST)) && 1182 !tcpflg_match(tcp, f)) 1183 continue; 1184 goto check_ports; 1185 } 1186 1187 case IPPROTO_UDP: 1188 if (offset != 0) { 1189 /* 1190 * Port specification is unavailable -- if this 1191 * rule specifies a port, we consider the rule 1192 * a non-match. 1193 */ 1194 if (f->fw_nports != 0) 1195 continue; 1196 1197 break; 1198 } 1199 check_ports: 1200 if (!port_match(&f->fw_uar.fw_pts[0], 1201 IP_FW_GETNSRCP(f), ntohs(src_port), 1202 f->fw_flg & IP_FW_F_SRNG, 1203 f->fw_flg & IP_FW_F_SMSK)) 1204 continue; 1205 if (!port_match(&f->fw_uar.fw_pts[IP_FW_GETNSRCP(f)], 1206 IP_FW_GETNDSTP(f), ntohs(dst_port), 1207 f->fw_flg & IP_FW_F_DRNG, 1208 f->fw_flg & IP_FW_F_DMSK)) 1209 continue; 1210 break; 1211 1212 case IPPROTO_ICMP: 1213 { 1214 struct icmp *icmp; 1215 1216 if (offset != 0) /* Type isn't valid */ 1217 break; 1218 icmp = (struct icmp *) ((u_int32_t *)ip + ip->ip_hl); 1219 if (!icmptype_match(icmp, f)) 1220 continue; 1221 break; 1222 } 1223 1224 default: 1225 break; 1226 1227 bogusfrag: 1228 if (fw_verbose) 1229 ipfw_report(NULL, ip, rif, oif); 1230 goto dropit; 1231 1232 } 1233 1234 rnd_then_got_match: 1235 if ( ((struct ip_fw_ext *)f)->dont_match_prob && 1236 random() < ((struct ip_fw_ext *)f)->dont_match_prob ) 1237 continue ; 1238 got_match: 1239 #if STATEFUL /* stateful ipfw */ 1240 /* 1241 * If have a dynamic match (q != NULL) set f to the right rule; 1242 * else, if have keep-state, install a new dynamic entry. 1243 * The packet info is in last_pkt. 1244 */ 1245 if (q != NULL) 1246 f = chain->rule ; 1247 else if (f->fw_flg & IP_FW_F_KEEP_S) 1248 install_state(chain, pip, ip); 1249 #endif 1250 *flow_id = chain ; /* XXX set flow id */ 1251 /* Update statistics */ 1252 f->fw_pcnt += 1; 1253 if (ip) { 1254 f->fw_bcnt += ip->ip_len; 1255 } 1256 f->timestamp = time_second; 1257 1258 /* Log to console if desired */ 1259 if ((f->fw_flg & IP_FW_F_PRN) && fw_verbose) 1260 ipfw_report(f, ip, rif, oif); 1261 1262 /* Take appropriate action */ 1263 switch (f->fw_flg & IP_FW_F_COMMAND) { 1264 case IP_FW_F_ACCEPT: 1265 return(0); 1266 case IP_FW_F_COUNT: 1267 continue; 1268 #ifdef IPDIVERT 1269 case IP_FW_F_DIVERT: 1270 *cookie = f->fw_number; 1271 return(f->fw_divert_port); 1272 case IP_FW_F_TEE: 1273 /* 1274 * XXX someday tee packet here, but beware that you 1275 * can't use m_copym() or m_copypacket() because 1276 * the divert input routine modifies the mbuf 1277 * (and these routines only increment reference 1278 * counts in the case of mbuf clusters), so need 1279 * to write custom routine. 1280 */ 1281 continue; 1282 #endif 1283 case IP_FW_F_SKIPTO: /* XXX check */ 1284 if ( f->next_rule_ptr ) 1285 chain = f->next_rule_ptr ; 1286 else 1287 chain = lookup_next_rule(chain) ; 1288 if (! chain) goto dropit; 1289 goto again ; 1290 #ifdef DUMMYNET 1291 case IP_FW_F_PIPE: 1292 return(f->fw_pipe_nr | IP_FW_PORT_DYNT_FLAG ); 1293 #endif 1294 #ifdef IPFIREWALL_FORWARD 1295 case IP_FW_F_FWD: 1296 /* Change the next-hop address for this packet. 1297 * Initially we'll only worry about directly 1298 * reachable next-hop's, but ultimately 1299 * we will work out for next-hops that aren't 1300 * direct the route we would take for it. We 1301 * [cs]ould leave this latter problem to 1302 * ip_output.c. We hope to high [name the abode of 1303 * your favourite deity] that ip_output doesn't modify 1304 * the new value of next_hop (which is dst there) 1305 */ 1306 if (next_hop != NULL) /* Make sure, first... */ 1307 *next_hop = &(f->fw_fwd_ip); 1308 return(0); /* Allow the packet */ 1309 #endif 1310 } 1311 1312 /* Deny/reject this packet using this rule */ 1313 rule = f; 1314 break; 1315 1316 } 1317 1318 #ifdef DIAGNOSTIC 1319 /* Rule IPFW_DEFAULT_RULE should always be there and should always match */ 1320 if (!chain) 1321 panic("ip_fw: chain"); 1322 #endif 1323 1324 /* 1325 * At this point, we're going to drop the packet. 1326 * Send a reject notice if all of the following are true: 1327 * 1328 * - The packet matched a reject rule 1329 * - The packet is not an ICMP packet, or is an ICMP query packet 1330 * - The packet is not a multicast or broadcast packet 1331 */ 1332 if ((rule->fw_flg & IP_FW_F_COMMAND) == IP_FW_F_REJECT 1333 && ip 1334 && (ip->ip_p != IPPROTO_ICMP || is_icmp_query(ip)) 1335 && !((*m)->m_flags & (M_BCAST|M_MCAST)) 1336 && !IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { 1337 switch (rule->fw_reject_code) { 1338 case IP_FW_REJECT_RST: 1339 { 1340 struct tcphdr *const tcp = 1341 (struct tcphdr *) ((u_int32_t *)ip + ip->ip_hl); 1342 struct tcpiphdr ti, *const tip = (struct tcpiphdr *) ip; 1343 1344 if (offset != 0 || (tcp->th_flags & TH_RST)) 1345 break; 1346 ti.ti_i = *((struct ipovly *) ip); 1347 ti.ti_t = *tcp; 1348 bcopy(&ti, ip, sizeof(ti)); 1349 NTOHL(tip->ti_seq); 1350 NTOHL(tip->ti_ack); 1351 tip->ti_len = ip->ip_len - hlen - (tip->ti_off << 2); 1352 if (tcp->th_flags & TH_ACK) { 1353 tcp_respond(NULL, tip, *m, 1354 (tcp_seq)0, ntohl(tcp->th_ack), TH_RST); 1355 } else { 1356 if (tcp->th_flags & TH_SYN) 1357 tip->ti_len++; 1358 tcp_respond(NULL, tip, *m, tip->ti_seq 1359 + tip->ti_len, (tcp_seq)0, TH_RST|TH_ACK); 1360 } 1361 *m = NULL; 1362 break; 1363 } 1364 default: /* Send an ICMP unreachable using code */ 1365 icmp_error(*m, ICMP_UNREACH, 1366 rule->fw_reject_code, 0L, 0); 1367 *m = NULL; 1368 break; 1369 } 1370 } 1371 1372 dropit: 1373 /* 1374 * Finally, drop the packet. 1375 */ 1376 if (*m) { 1377 m_freem(*m); 1378 *m = NULL; 1379 } 1380 return(0); 1381 } 1382 1383 /* 1384 * when a rule is added/deleted, zero the direct pointers within 1385 * all firewall rules. These will be reconstructed on the fly 1386 * as packets are matched. 1387 * Must be called at splnet(). 1388 */ 1389 static void 1390 flush_rule_ptrs() 1391 { 1392 struct ip_fw_chain *fcp ; 1393 1394 for (fcp = ip_fw_chain.lh_first; fcp; fcp = fcp->chain.le_next) { 1395 fcp->rule->next_rule_ptr = NULL ; 1396 } 1397 } 1398 1399 static int 1400 add_entry(struct ip_fw_head *chainptr, struct ip_fw *frwl) 1401 { 1402 struct ip_fw *ftmp = 0; 1403 struct ip_fw_ext *ftmp_ext = 0 ; 1404 struct ip_fw_chain *fwc = 0, *fcp, *fcpl = 0; 1405 u_short nbr = 0; 1406 int s; 1407 1408 fwc = malloc(sizeof *fwc, M_IPFW, M_DONTWAIT); 1409 ftmp_ext = malloc(sizeof *ftmp_ext, M_IPFW, M_DONTWAIT); 1410 ftmp = &ftmp_ext->rule ; 1411 if (!fwc || !ftmp) { 1412 dprintf(("%s malloc said no\n", err_prefix)); 1413 if (fwc) free(fwc, M_IPFW); 1414 if (ftmp) free(ftmp, M_IPFW); 1415 return (ENOSPC); 1416 } 1417 1418 bzero(ftmp_ext, sizeof(*ftmp_ext)); /* play safe! */ 1419 bcopy(frwl, ftmp, sizeof(*ftmp)); 1420 if (ftmp->fw_flg & IP_FW_F_RND_MATCH) 1421 ftmp_ext->dont_match_prob = (long)(ftmp->pipe_ptr) ; 1422 if (ftmp->fw_flg & IP_FW_F_KEEP_S) 1423 ftmp_ext->dyn_type = (u_long)(ftmp->next_rule_ptr) ; 1424 1425 ftmp->fw_in_if.fu_via_if.name[FW_IFNLEN - 1] = '\0'; 1426 ftmp->fw_pcnt = 0L; 1427 ftmp->fw_bcnt = 0L; 1428 ftmp->next_rule_ptr = NULL ; 1429 ftmp->pipe_ptr = NULL ; 1430 fwc->rule = ftmp; 1431 1432 s = splnet(); 1433 1434 if (chainptr->lh_first == 0) { 1435 LIST_INSERT_HEAD(chainptr, fwc, chain); 1436 splx(s); 1437 return(0); 1438 } 1439 1440 /* If entry number is 0, find highest numbered rule and add 100 */ 1441 if (ftmp->fw_number == 0) { 1442 for (fcp = LIST_FIRST(chainptr); fcp; fcp = LIST_NEXT(fcp, chain)) { 1443 if (fcp->rule->fw_number != (u_short)-1) 1444 nbr = fcp->rule->fw_number; 1445 else 1446 break; 1447 } 1448 if (nbr < IPFW_DEFAULT_RULE - 100) 1449 nbr += 100; 1450 ftmp->fw_number = nbr; 1451 } 1452 1453 /* Got a valid number; now insert it, keeping the list ordered */ 1454 for (fcp = LIST_FIRST(chainptr); fcp; fcp = LIST_NEXT(fcp, chain)) { 1455 if (fcp->rule->fw_number > ftmp->fw_number) { 1456 if (fcpl) { 1457 LIST_INSERT_AFTER(fcpl, fwc, chain); 1458 } else { 1459 LIST_INSERT_HEAD(chainptr, fwc, chain); 1460 } 1461 break; 1462 } else { 1463 fcpl = fcp; 1464 } 1465 } 1466 flush_rule_ptrs(); 1467 1468 splx(s); 1469 return (0); 1470 } 1471 1472 static int 1473 del_entry(struct ip_fw_head *chainptr, u_short number) 1474 { 1475 struct ip_fw_chain *fcp; 1476 1477 fcp = LIST_FIRST(chainptr); 1478 if (number != (u_short)-1) { 1479 for (; fcp; fcp = LIST_NEXT(fcp, chain)) { 1480 if (fcp->rule->fw_number == number) { 1481 int s; 1482 1483 /* prevent access to rules while removing them */ 1484 s = splnet(); 1485 while (fcp && fcp->rule->fw_number == number) { 1486 struct ip_fw_chain *next; 1487 1488 #if STATEFUL 1489 remove_dyn_rule(fcp, 1 /* force_delete */); 1490 #endif 1491 next = LIST_NEXT(fcp, chain); 1492 LIST_REMOVE(fcp, chain); 1493 #ifdef DUMMYNET 1494 dn_rule_delete(fcp) ; 1495 #endif 1496 flush_rule_ptrs(); 1497 free(fcp->rule, M_IPFW); 1498 free(fcp, M_IPFW); 1499 fcp = next; 1500 } 1501 splx(s); 1502 return 0; 1503 } 1504 } 1505 } 1506 1507 return (EINVAL); 1508 } 1509 1510 static int 1511 zero_entry(struct ip_fw *frwl) 1512 { 1513 struct ip_fw_chain *fcp; 1514 int s, cleared; 1515 1516 if (frwl == 0) { 1517 s = splnet(); 1518 for (fcp = LIST_FIRST(&ip_fw_chain); fcp; fcp = LIST_NEXT(fcp, chain)) { 1519 fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0; 1520 fcp->rule->fw_loghighest = fcp->rule->fw_logamount; 1521 fcp->rule->timestamp = 0; 1522 } 1523 splx(s); 1524 } 1525 else { 1526 cleared = 0; 1527 1528 /* 1529 * It's possible to insert multiple chain entries with the 1530 * same number, so we don't stop after finding the first 1531 * match if zeroing a specific entry. 1532 */ 1533 for (fcp = LIST_FIRST(&ip_fw_chain); fcp; fcp = LIST_NEXT(fcp, chain)) 1534 if (frwl->fw_number == fcp->rule->fw_number) { 1535 s = splnet(); 1536 while (fcp && frwl->fw_number == fcp->rule->fw_number) { 1537 fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0; 1538 fcp->rule->fw_loghighest = 1539 fcp->rule->fw_logamount; 1540 fcp->rule->timestamp = 0; 1541 fcp = LIST_NEXT(fcp, chain); 1542 } 1543 splx(s); 1544 cleared = 1; 1545 break; 1546 } 1547 if (!cleared) /* we didn't find any matching rules */ 1548 return (EINVAL); 1549 } 1550 1551 if (fw_verbose) { 1552 if (frwl) 1553 printf("ipfw: Entry %d cleared.\n", frwl->fw_number); 1554 else 1555 printf("ipfw: Accounting cleared.\n"); 1556 } 1557 1558 return (0); 1559 } 1560 1561 static int 1562 resetlog_entry(struct ip_fw *frwl) 1563 { 1564 struct ip_fw_chain *fcp; 1565 int s, cleared; 1566 1567 if (frwl == 0) { 1568 s = splnet(); 1569 counter = 0; 1570 for (fcp = LIST_FIRST(&ip_fw_chain); fcp; fcp = LIST_NEXT(fcp, chain)) 1571 fcp->rule->fw_loghighest = fcp->rule->fw_pcnt + 1572 fcp->rule->fw_logamount; 1573 splx(s); 1574 } 1575 else { 1576 cleared = 0; 1577 1578 /* 1579 * It's possible to insert multiple chain entries with the 1580 * same number, so we don't stop after finding the first 1581 * match if zeroing a specific entry. 1582 */ 1583 for (fcp = LIST_FIRST(&ip_fw_chain); fcp; fcp = LIST_NEXT(fcp, chain)) 1584 if (frwl->fw_number == fcp->rule->fw_number) { 1585 s = splnet(); 1586 while (fcp && frwl->fw_number == fcp->rule->fw_number) { 1587 fcp->rule->fw_loghighest = 1588 fcp->rule->fw_pcnt + 1589 fcp->rule->fw_logamount; 1590 fcp = LIST_NEXT(fcp, chain); 1591 } 1592 splx(s); 1593 cleared = 1; 1594 break; 1595 } 1596 if (!cleared) /* we didn't find any matching rules */ 1597 return (EINVAL); 1598 } 1599 1600 if (fw_verbose) { 1601 if (frwl) 1602 printf("ipfw: Entry %d logging count reset.\n", 1603 frwl->fw_number); 1604 else 1605 printf("ipfw: All logging counts cleared.\n"); 1606 } 1607 1608 return (0); 1609 } 1610 1611 static int 1612 check_ipfw_struct(struct ip_fw *frwl) 1613 { 1614 /* Check for invalid flag bits */ 1615 if ((frwl->fw_flg & ~IP_FW_F_MASK) != 0) { 1616 dprintf(("%s undefined flag bits set (flags=%x)\n", 1617 err_prefix, frwl->fw_flg)); 1618 return (EINVAL); 1619 } 1620 if (frwl->fw_flg == IP_FW_F_CHECK_S) { 1621 /* check-state */ 1622 return 0 ; 1623 } 1624 /* Must apply to incoming or outgoing (or both) */ 1625 if (!(frwl->fw_flg & (IP_FW_F_IN | IP_FW_F_OUT))) { 1626 dprintf(("%s neither in nor out\n", err_prefix)); 1627 return (EINVAL); 1628 } 1629 /* Empty interface name is no good */ 1630 if (((frwl->fw_flg & IP_FW_F_IIFNAME) 1631 && !*frwl->fw_in_if.fu_via_if.name) 1632 || ((frwl->fw_flg & IP_FW_F_OIFNAME) 1633 && !*frwl->fw_out_if.fu_via_if.name)) { 1634 dprintf(("%s empty interface name\n", err_prefix)); 1635 return (EINVAL); 1636 } 1637 /* Sanity check interface matching */ 1638 if ((frwl->fw_flg & IF_FW_F_VIAHACK) == IF_FW_F_VIAHACK) { 1639 ; /* allow "via" backwards compatibility */ 1640 } else if ((frwl->fw_flg & IP_FW_F_IN) 1641 && (frwl->fw_flg & IP_FW_F_OIFACE)) { 1642 dprintf(("%s outgoing interface check on incoming\n", 1643 err_prefix)); 1644 return (EINVAL); 1645 } 1646 /* Sanity check port ranges */ 1647 if ((frwl->fw_flg & IP_FW_F_SRNG) && IP_FW_GETNSRCP(frwl) < 2) { 1648 dprintf(("%s src range set but n_src_p=%d\n", 1649 err_prefix, IP_FW_GETNSRCP(frwl))); 1650 return (EINVAL); 1651 } 1652 if ((frwl->fw_flg & IP_FW_F_DRNG) && IP_FW_GETNDSTP(frwl) < 2) { 1653 dprintf(("%s dst range set but n_dst_p=%d\n", 1654 err_prefix, IP_FW_GETNDSTP(frwl))); 1655 return (EINVAL); 1656 } 1657 if (IP_FW_GETNSRCP(frwl) + IP_FW_GETNDSTP(frwl) > IP_FW_MAX_PORTS) { 1658 dprintf(("%s too many ports (%d+%d)\n", 1659 err_prefix, IP_FW_GETNSRCP(frwl), IP_FW_GETNDSTP(frwl))); 1660 return (EINVAL); 1661 } 1662 /* 1663 * Protocols other than TCP/UDP don't use port range 1664 */ 1665 if ((frwl->fw_prot != IPPROTO_TCP) && 1666 (frwl->fw_prot != IPPROTO_UDP) && 1667 (IP_FW_GETNSRCP(frwl) || IP_FW_GETNDSTP(frwl))) { 1668 dprintf(("%s port(s) specified for non TCP/UDP rule\n", 1669 err_prefix)); 1670 return (EINVAL); 1671 } 1672 1673 /* 1674 * Rather than modify the entry to make such entries work, 1675 * we reject this rule and require user level utilities 1676 * to enforce whatever policy they deem appropriate. 1677 */ 1678 if ((frwl->fw_src.s_addr & (~frwl->fw_smsk.s_addr)) || 1679 (frwl->fw_dst.s_addr & (~frwl->fw_dmsk.s_addr))) { 1680 dprintf(("%s rule never matches\n", err_prefix)); 1681 return (EINVAL); 1682 } 1683 1684 if ((frwl->fw_flg & IP_FW_F_FRAG) && 1685 (frwl->fw_prot == IPPROTO_UDP || frwl->fw_prot == IPPROTO_TCP)) { 1686 if (frwl->fw_nports) { 1687 dprintf(("%s cannot mix 'frag' and ports\n", err_prefix)); 1688 return (EINVAL); 1689 } 1690 if (frwl->fw_prot == IPPROTO_TCP && 1691 frwl->fw_tcpf != frwl->fw_tcpnf) { 1692 dprintf(("%s cannot mix 'frag' and TCP flags\n", err_prefix)); 1693 return (EINVAL); 1694 } 1695 } 1696 1697 /* Check command specific stuff */ 1698 switch (frwl->fw_flg & IP_FW_F_COMMAND) 1699 { 1700 case IP_FW_F_REJECT: 1701 if (frwl->fw_reject_code >= 0x100 1702 && !(frwl->fw_prot == IPPROTO_TCP 1703 && frwl->fw_reject_code == IP_FW_REJECT_RST)) { 1704 dprintf(("%s unknown reject code\n", err_prefix)); 1705 return (EINVAL); 1706 } 1707 break; 1708 #if defined(IPDIVERT) || defined(DUMMYNET) 1709 #ifdef IPDIVERT 1710 case IP_FW_F_DIVERT: /* Diverting to port zero is invalid */ 1711 case IP_FW_F_TEE: 1712 #endif 1713 #ifdef DUMMYNET 1714 case IP_FW_F_PIPE: /* piping through 0 is invalid */ 1715 #endif 1716 if (frwl->fw_divert_port == 0) { 1717 dprintf(("%s can't divert to port 0\n", err_prefix)); 1718 return (EINVAL); 1719 } 1720 break; 1721 #endif /* IPDIVERT || DUMMYNET */ 1722 case IP_FW_F_DENY: 1723 case IP_FW_F_ACCEPT: 1724 case IP_FW_F_COUNT: 1725 case IP_FW_F_SKIPTO: 1726 #ifdef IPFIREWALL_FORWARD 1727 case IP_FW_F_FWD: 1728 #endif 1729 case IP_FW_F_UID: 1730 case IP_FW_F_GID: 1731 break; 1732 default: 1733 dprintf(("%s invalid command\n", err_prefix)); 1734 return (EINVAL); 1735 } 1736 1737 return 0; 1738 } 1739 1740 static int 1741 ip_fw_ctl(struct sockopt *sopt) 1742 { 1743 int error, s; 1744 size_t size; 1745 struct ip_fw_chain *fcp; 1746 struct ip_fw frwl, *bp , *buf; 1747 1748 /* 1749 * Disallow sets in really-really secure mode, but still allow 1750 * the logging counters to be reset. 1751 */ 1752 if (sopt->sopt_dir == SOPT_SET && securelevel >= 3 && 1753 sopt->sopt_name != IP_FW_RESETLOG) 1754 return (EPERM); 1755 error = 0; 1756 1757 switch (sopt->sopt_name) { 1758 case IP_FW_GET: 1759 for (fcp = LIST_FIRST(&ip_fw_chain), size = 0; fcp; 1760 fcp = LIST_NEXT(fcp, chain)) 1761 size += sizeof *fcp->rule; 1762 #if STATEFUL 1763 if (ipfw_dyn_v) { 1764 int i ; 1765 struct ipfw_dyn_rule *p ; 1766 1767 for (i = 0 ; i < curr_dyn_buckets ; i++ ) 1768 for ( p = ipfw_dyn_v[i] ; p != NULL ; p = p->next ) 1769 size += sizeof(*p) ; 1770 } 1771 #endif 1772 buf = malloc(size, M_TEMP, M_WAITOK); 1773 if (buf == 0) { 1774 error = ENOBUFS; 1775 break; 1776 } 1777 1778 for (fcp = LIST_FIRST(&ip_fw_chain), bp = buf; fcp; 1779 fcp = LIST_NEXT(fcp, chain)) { 1780 bcopy(fcp->rule, bp, sizeof *fcp->rule); 1781 bp->pipe_ptr = (void *)(intptr_t) 1782 ((struct ip_fw_ext *)fcp->rule)->dont_match_prob; 1783 bp->next_rule_ptr = (void *)(intptr_t) 1784 ((struct ip_fw_ext *)fcp->rule)->dyn_type; 1785 bp ++ ; 1786 } 1787 #if STATEFUL 1788 if (ipfw_dyn_v) { 1789 int i ; 1790 struct ipfw_dyn_rule *p, *dst, *last = NULL ; 1791 1792 dst = (struct ipfw_dyn_rule *)bp ; 1793 for (i = 0 ; i < curr_dyn_buckets ; i++ ) 1794 for (p=ipfw_dyn_v[i] ; p!=NULL ; p=p->next, dst++ ) { 1795 bcopy(p, dst, sizeof *p); 1796 (int)dst->chain = p->chain->rule->fw_number ; 1797 dst->next = dst ; /* fake non-null pointer... */ 1798 last = dst ; 1799 if (TIME_LEQ(dst->expire, time_second) ) 1800 dst->expire = 0 ; 1801 else 1802 dst->expire -= time_second ; 1803 } 1804 if (last != NULL) 1805 last->next = NULL ; 1806 } 1807 #endif 1808 error = sooptcopyout(sopt, buf, size); 1809 FREE(buf, M_TEMP); 1810 break; 1811 1812 case IP_FW_FLUSH: 1813 #if STATEFUL 1814 s = splnet(); 1815 remove_dyn_rule(NULL, 1 /* force delete */); 1816 splx(s); 1817 #endif 1818 for (fcp = ip_fw_chain.lh_first; 1819 fcp != 0 && fcp->rule->fw_number != IPFW_DEFAULT_RULE; 1820 fcp = ip_fw_chain.lh_first) { 1821 s = splnet(); 1822 LIST_REMOVE(fcp, chain); 1823 #ifdef DUMMYNET 1824 dn_rule_delete(fcp); 1825 #endif 1826 FREE(fcp->rule, M_IPFW); 1827 FREE(fcp, M_IPFW); 1828 splx(s); 1829 } 1830 break; 1831 1832 case IP_FW_ZERO: 1833 if (sopt->sopt_val != 0) { 1834 error = sooptcopyin(sopt, &frwl, sizeof frwl, 1835 sizeof frwl); 1836 if (error || (error = zero_entry(&frwl))) 1837 break; 1838 } else { 1839 error = zero_entry(0); 1840 } 1841 break; 1842 1843 case IP_FW_ADD: 1844 error = sooptcopyin(sopt, &frwl, sizeof frwl, sizeof frwl); 1845 if (error || (error = check_ipfw_struct(&frwl))) 1846 break; 1847 1848 if (frwl.fw_number == IPFW_DEFAULT_RULE) { 1849 dprintf(("%s can't add rule %u\n", err_prefix, 1850 (unsigned)IPFW_DEFAULT_RULE)); 1851 error = EINVAL; 1852 } else { 1853 error = add_entry(&ip_fw_chain, &frwl); 1854 } 1855 break; 1856 1857 case IP_FW_DEL: 1858 error = sooptcopyin(sopt, &frwl, sizeof frwl, sizeof frwl); 1859 if (error) 1860 break; 1861 1862 if (frwl.fw_number == IPFW_DEFAULT_RULE) { 1863 dprintf(("%s can't delete rule %u\n", err_prefix, 1864 (unsigned)IPFW_DEFAULT_RULE)); 1865 error = EINVAL; 1866 } else { 1867 error = del_entry(&ip_fw_chain, frwl.fw_number); 1868 } 1869 break; 1870 1871 case IP_FW_RESETLOG: 1872 if (sopt->sopt_val != 0) { 1873 error = sooptcopyin(sopt, &frwl, sizeof frwl, 1874 sizeof frwl); 1875 if (error || (error = resetlog_entry(&frwl))) 1876 break; 1877 } else { 1878 error = resetlog_entry(0); 1879 } 1880 break; 1881 1882 default: 1883 printf("ip_fw_ctl invalid option %d\n", sopt->sopt_name); 1884 error = EINVAL ; 1885 } 1886 1887 return (error); 1888 } 1889 1890 struct ip_fw_chain *ip_fw_default_rule ; 1891 1892 void 1893 ip_fw_init(void) 1894 { 1895 struct ip_fw default_rule; 1896 1897 ip_fw_chk_ptr = ip_fw_chk; 1898 ip_fw_ctl_ptr = ip_fw_ctl; 1899 LIST_INIT(&ip_fw_chain); 1900 1901 bzero(&default_rule, sizeof default_rule); 1902 default_rule.fw_prot = IPPROTO_IP; 1903 default_rule.fw_number = IPFW_DEFAULT_RULE; 1904 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 1905 default_rule.fw_flg |= IP_FW_F_ACCEPT; 1906 #else 1907 default_rule.fw_flg |= IP_FW_F_DENY; 1908 #endif 1909 default_rule.fw_flg |= IP_FW_F_IN | IP_FW_F_OUT; 1910 if (check_ipfw_struct(&default_rule) != 0 || 1911 add_entry(&ip_fw_chain, &default_rule)) 1912 panic("ip_fw_init"); 1913 1914 ip_fw_default_rule = ip_fw_chain.lh_first ; 1915 printf("IP packet filtering initialized, " 1916 #ifdef IPDIVERT 1917 "divert enabled, " 1918 #else 1919 "divert disabled, " 1920 #endif 1921 #ifdef IPFIREWALL_FORWARD 1922 "rule-based forwarding enabled, " 1923 #else 1924 "rule-based forwarding disabled, " 1925 #endif 1926 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT 1927 "default to accept, " ); 1928 #else 1929 "default to deny, " ); 1930 #endif 1931 #ifndef IPFIREWALL_VERBOSE 1932 printf("logging disabled\n"); 1933 #else 1934 if (fw_verbose_limit == 0) 1935 printf("unlimited logging\n"); 1936 else 1937 printf("logging limited to %d packets/entry by default\n", 1938 fw_verbose_limit); 1939 #endif 1940 } 1941 1942 static ip_fw_chk_t *old_chk_ptr; 1943 static ip_fw_ctl_t *old_ctl_ptr; 1944 1945 #if defined(IPFIREWALL_MODULE) && !defined(KLD_MODULE) 1946 1947 #include <sys/exec.h> 1948 #include <sys/sysent.h> 1949 #include <sys/lkm.h> 1950 1951 MOD_MISC(ipfw); 1952 1953 static int 1954 ipfw_load(struct lkm_table *lkmtp, int cmd) 1955 { 1956 int s=splnet(); 1957 1958 old_chk_ptr = ip_fw_chk_ptr; 1959 old_ctl_ptr = ip_fw_ctl_ptr; 1960 1961 ip_fw_init(); 1962 splx(s); 1963 return 0; 1964 } 1965 1966 static int 1967 ipfw_unload(struct lkm_table *lkmtp, int cmd) 1968 { 1969 int s=splnet(); 1970 1971 ip_fw_chk_ptr = old_chk_ptr; 1972 ip_fw_ctl_ptr = old_ctl_ptr; 1973 #if STATEFUL 1974 remove_dyn_rule(NULL, 1 /* force delete */); 1975 #endif 1976 while (LIST_FIRST(&ip_fw_chain) != NULL) { 1977 struct ip_fw_chain *fcp = LIST_FIRST(&ip_fw_chain); 1978 LIST_REMOVE(LIST_FIRST(&ip_fw_chain), chain); 1979 #ifdef DUMMYNET 1980 dn_rule_delete(fcp); 1981 #endif 1982 free(fcp->rule, M_IPFW); 1983 free(fcp, M_IPFW); 1984 } 1985 1986 splx(s); 1987 printf("IP firewall unloaded\n"); 1988 return 0; 1989 } 1990 1991 int 1992 ipfw_mod(struct lkm_table *lkmtp, int cmd, int ver) 1993 { 1994 MOD_DISPATCH(ipfw, lkmtp, cmd, ver, 1995 ipfw_load, ipfw_unload, lkm_nullcmd); 1996 } 1997 #else 1998 static int 1999 ipfw_modevent(module_t mod, int type, void *unused) 2000 { 2001 int s; 2002 2003 switch (type) { 2004 case MOD_LOAD: 2005 s = splnet(); 2006 2007 old_chk_ptr = ip_fw_chk_ptr; 2008 old_ctl_ptr = ip_fw_ctl_ptr; 2009 2010 ip_fw_init(); 2011 splx(s); 2012 return 0; 2013 case MOD_UNLOAD: 2014 s = splnet(); 2015 ip_fw_chk_ptr = old_chk_ptr; 2016 ip_fw_ctl_ptr = old_ctl_ptr; 2017 #if STATEFUL 2018 remove_dyn_rule(NULL, 1 /* force delete */); 2019 #endif 2020 while (LIST_FIRST(&ip_fw_chain) != NULL) { 2021 struct ip_fw_chain *fcp = LIST_FIRST(&ip_fw_chain); 2022 LIST_REMOVE(LIST_FIRST(&ip_fw_chain), chain); 2023 #ifdef DUMMYNET 2024 dn_rule_delete(fcp); 2025 #endif 2026 free(fcp->rule, M_IPFW); 2027 free(fcp, M_IPFW); 2028 } 2029 2030 splx(s); 2031 printf("IP firewall unloaded\n"); 2032 return 0; 2033 default: 2034 break; 2035 } 2036 return 0; 2037 } 2038 2039 static moduledata_t ipfwmod = { 2040 "ipfw", 2041 ipfw_modevent, 2042 0 2043 }; 2044 DECLARE_MODULE(ipfw, ipfwmod, SI_SUB_PSEUDO, SI_ORDER_ANY); 2045 #endif
Cache object: 7b2c613b3997d7df94311a887bb157fe
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