1 /*- 2 * Copyright (c) 2008 Paolo Pisati 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/eventhandler.h> 33 #include <sys/malloc.h> 34 #include <sys/kernel.h> 35 #include <sys/lock.h> 36 #include <sys/module.h> 37 #include <sys/rwlock.h> 38 39 #define IPFW_INTERNAL /* Access to protected data structures in ip_fw.h. */ 40 41 #include <netinet/libalias/alias.h> 42 #include <netinet/libalias/alias_local.h> 43 44 #include <net/if.h> 45 #include <netinet/in.h> 46 #include <netinet/ip.h> 47 #include <netinet/ip_var.h> 48 #include <netinet/ip_fw.h> 49 #include <netinet/tcp.h> 50 #include <netinet/udp.h> 51 52 #include <netpfil/ipfw/ip_fw_private.h> 53 54 #include <machine/in_cksum.h> /* XXX for in_cksum */ 55 56 static VNET_DEFINE(eventhandler_tag, ifaddr_event_tag); 57 #define V_ifaddr_event_tag VNET(ifaddr_event_tag) 58 59 static void 60 ifaddr_change(void *arg __unused, struct ifnet *ifp) 61 { 62 struct cfg_nat *ptr; 63 struct ifaddr *ifa; 64 struct ip_fw_chain *chain; 65 66 chain = &V_layer3_chain; 67 IPFW_WLOCK(chain); 68 /* Check every nat entry... */ 69 LIST_FOREACH(ptr, &chain->nat, _next) { 70 /* ...using nic 'ifp->if_xname' as dynamic alias address. */ 71 if (strncmp(ptr->if_name, ifp->if_xname, IF_NAMESIZE) != 0) 72 continue; 73 if_addr_rlock(ifp); 74 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 75 if (ifa->ifa_addr == NULL) 76 continue; 77 if (ifa->ifa_addr->sa_family != AF_INET) 78 continue; 79 ptr->ip = ((struct sockaddr_in *) 80 (ifa->ifa_addr))->sin_addr; 81 LibAliasSetAddress(ptr->lib, ptr->ip); 82 } 83 if_addr_runlock(ifp); 84 } 85 IPFW_WUNLOCK(chain); 86 } 87 88 /* 89 * delete the pointers for nat entry ix, or all of them if ix < 0 90 */ 91 static void 92 flush_nat_ptrs(struct ip_fw_chain *chain, const int ix) 93 { 94 int i; 95 ipfw_insn_nat *cmd; 96 97 IPFW_WLOCK_ASSERT(chain); 98 for (i = 0; i < chain->n_rules; i++) { 99 cmd = (ipfw_insn_nat *)ACTION_PTR(chain->map[i]); 100 /* XXX skip log and the like ? */ 101 if (cmd->o.opcode == O_NAT && cmd->nat != NULL && 102 (ix < 0 || cmd->nat->id == ix)) 103 cmd->nat = NULL; 104 } 105 } 106 107 static void 108 del_redir_spool_cfg(struct cfg_nat *n, struct redir_chain *head) 109 { 110 struct cfg_redir *r, *tmp_r; 111 struct cfg_spool *s, *tmp_s; 112 int i, num; 113 114 LIST_FOREACH_SAFE(r, head, _next, tmp_r) { 115 num = 1; /* Number of alias_link to delete. */ 116 switch (r->mode) { 117 case REDIR_PORT: 118 num = r->pport_cnt; 119 /* FALLTHROUGH */ 120 case REDIR_ADDR: 121 case REDIR_PROTO: 122 /* Delete all libalias redirect entry. */ 123 for (i = 0; i < num; i++) 124 LibAliasRedirectDelete(n->lib, r->alink[i]); 125 /* Del spool cfg if any. */ 126 LIST_FOREACH_SAFE(s, &r->spool_chain, _next, tmp_s) { 127 LIST_REMOVE(s, _next); 128 free(s, M_IPFW); 129 } 130 free(r->alink, M_IPFW); 131 LIST_REMOVE(r, _next); 132 free(r, M_IPFW); 133 break; 134 default: 135 printf("unknown redirect mode: %u\n", r->mode); 136 /* XXX - panic?!?!? */ 137 break; 138 } 139 } 140 } 141 142 static void 143 add_redir_spool_cfg(char *buf, struct cfg_nat *ptr) 144 { 145 struct cfg_redir *r, *ser_r; 146 struct cfg_spool *s, *ser_s; 147 int cnt, off, i; 148 149 for (cnt = 0, off = 0; cnt < ptr->redir_cnt; cnt++) { 150 ser_r = (struct cfg_redir *)&buf[off]; 151 r = malloc(SOF_REDIR, M_IPFW, M_WAITOK | M_ZERO); 152 memcpy(r, ser_r, SOF_REDIR); 153 LIST_INIT(&r->spool_chain); 154 off += SOF_REDIR; 155 r->alink = malloc(sizeof(struct alias_link *) * r->pport_cnt, 156 M_IPFW, M_WAITOK | M_ZERO); 157 switch (r->mode) { 158 case REDIR_ADDR: 159 r->alink[0] = LibAliasRedirectAddr(ptr->lib, r->laddr, 160 r->paddr); 161 break; 162 case REDIR_PORT: 163 for (i = 0 ; i < r->pport_cnt; i++) { 164 /* If remotePort is all ports, set it to 0. */ 165 u_short remotePortCopy = r->rport + i; 166 if (r->rport_cnt == 1 && r->rport == 0) 167 remotePortCopy = 0; 168 r->alink[i] = LibAliasRedirectPort(ptr->lib, 169 r->laddr, htons(r->lport + i), r->raddr, 170 htons(remotePortCopy), r->paddr, 171 htons(r->pport + i), r->proto); 172 if (r->alink[i] == NULL) { 173 r->alink[0] = NULL; 174 break; 175 } 176 } 177 break; 178 case REDIR_PROTO: 179 r->alink[0] = LibAliasRedirectProto(ptr->lib ,r->laddr, 180 r->raddr, r->paddr, r->proto); 181 break; 182 default: 183 printf("unknown redirect mode: %u\n", r->mode); 184 break; 185 } 186 /* XXX perhaps return an error instead of panic ? */ 187 if (r->alink[0] == NULL) 188 panic("LibAliasRedirect* returned NULL"); 189 /* LSNAT handling. */ 190 for (i = 0; i < r->spool_cnt; i++) { 191 ser_s = (struct cfg_spool *)&buf[off]; 192 s = malloc(SOF_REDIR, M_IPFW, M_WAITOK | M_ZERO); 193 memcpy(s, ser_s, SOF_SPOOL); 194 LibAliasAddServer(ptr->lib, r->alink[0], 195 s->addr, htons(s->port)); 196 off += SOF_SPOOL; 197 /* Hook spool entry. */ 198 LIST_INSERT_HEAD(&r->spool_chain, s, _next); 199 } 200 /* And finally hook this redir entry. */ 201 LIST_INSERT_HEAD(&ptr->redir_chain, r, _next); 202 } 203 } 204 205 static int 206 ipfw_nat(struct ip_fw_args *args, struct cfg_nat *t, struct mbuf *m) 207 { 208 struct mbuf *mcl; 209 struct ip *ip; 210 /* XXX - libalias duct tape */ 211 int ldt, retval, found; 212 struct ip_fw_chain *chain; 213 char *c; 214 215 ldt = 0; 216 retval = 0; 217 mcl = m_megapullup(m, m->m_pkthdr.len); 218 if (mcl == NULL) { 219 args->m = NULL; 220 return (IP_FW_DENY); 221 } 222 ip = mtod(mcl, struct ip *); 223 224 /* 225 * XXX - Libalias checksum offload 'duct tape': 226 * 227 * locally generated packets have only pseudo-header checksum 228 * calculated and libalias will break it[1], so mark them for 229 * later fix. Moreover there are cases when libalias modifies 230 * tcp packet data[2], mark them for later fix too. 231 * 232 * [1] libalias was never meant to run in kernel, so it does 233 * not have any knowledge about checksum offloading, and 234 * expects a packet with a full internet checksum. 235 * Unfortunately, packets generated locally will have just the 236 * pseudo header calculated, and when libalias tries to adjust 237 * the checksum it will actually compute a wrong value. 238 * 239 * [2] when libalias modifies tcp's data content, full TCP 240 * checksum has to be recomputed: the problem is that 241 * libalias does not have any idea about checksum offloading. 242 * To work around this, we do not do checksumming in LibAlias, 243 * but only mark the packets in th_x2 field. If we receive a 244 * marked packet, we calculate correct checksum for it 245 * aware of offloading. Why such a terrible hack instead of 246 * recalculating checksum for each packet? 247 * Because the previous checksum was not checked! 248 * Recalculating checksums for EVERY packet will hide ALL 249 * transmission errors. Yes, marked packets still suffer from 250 * this problem. But, sigh, natd(8) has this problem, too. 251 * 252 * TODO: -make libalias mbuf aware (so 253 * it can handle delayed checksum and tso) 254 */ 255 256 if (mcl->m_pkthdr.rcvif == NULL && 257 mcl->m_pkthdr.csum_flags & CSUM_DELAY_DATA) 258 ldt = 1; 259 260 c = mtod(mcl, char *); 261 262 /* Check if this is 'global' instance */ 263 if (t == NULL) { 264 if (args->oif == NULL) { 265 /* Wrong direction, skip processing */ 266 args->m = mcl; 267 return (IP_FW_NAT); 268 } 269 270 found = 0; 271 chain = &V_layer3_chain; 272 IPFW_RLOCK(chain); 273 /* Check every nat entry... */ 274 LIST_FOREACH(t, &chain->nat, _next) { 275 if ((t->mode & PKT_ALIAS_SKIP_GLOBAL) != 0) 276 continue; 277 retval = LibAliasOutTry(t->lib, c, 278 mcl->m_len + M_TRAILINGSPACE(mcl), 0); 279 if (retval == PKT_ALIAS_OK) { 280 /* Nat instance recognises state */ 281 found = 1; 282 break; 283 } 284 } 285 IPFW_RUNLOCK(chain); 286 if (found != 1) { 287 /* No instance found, return ignore */ 288 args->m = mcl; 289 return (IP_FW_NAT); 290 } 291 } else { 292 if (args->oif == NULL) 293 retval = LibAliasIn(t->lib, c, 294 mcl->m_len + M_TRAILINGSPACE(mcl)); 295 else 296 retval = LibAliasOut(t->lib, c, 297 mcl->m_len + M_TRAILINGSPACE(mcl)); 298 } 299 300 /* 301 * We drop packet when: 302 * 1. libalias returns PKT_ALIAS_ERROR; 303 * 2. For incoming packets: 304 * a) for unresolved fragments; 305 * b) libalias returns PKT_ALIAS_IGNORED and 306 * PKT_ALIAS_DENY_INCOMING flag is set. 307 */ 308 if (retval == PKT_ALIAS_ERROR || 309 (args->oif == NULL && (retval == PKT_ALIAS_UNRESOLVED_FRAGMENT || 310 (retval == PKT_ALIAS_IGNORED && 311 (t->mode & PKT_ALIAS_DENY_INCOMING) != 0)))) { 312 /* XXX - should i add some logging? */ 313 m_free(mcl); 314 args->m = NULL; 315 return (IP_FW_DENY); 316 } 317 318 if (retval == PKT_ALIAS_RESPOND) 319 mcl->m_flags |= M_SKIP_FIREWALL; 320 mcl->m_pkthdr.len = mcl->m_len = ntohs(ip->ip_len); 321 322 /* 323 * XXX - libalias checksum offload 324 * 'duct tape' (see above) 325 */ 326 327 if ((ip->ip_off & htons(IP_OFFMASK)) == 0 && 328 ip->ip_p == IPPROTO_TCP) { 329 struct tcphdr *th; 330 331 th = (struct tcphdr *)(ip + 1); 332 if (th->th_x2) 333 ldt = 1; 334 } 335 336 if (ldt) { 337 struct tcphdr *th; 338 struct udphdr *uh; 339 uint16_t ip_len, cksum; 340 341 ip_len = ntohs(ip->ip_len); 342 cksum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 343 htons(ip->ip_p + ip_len - (ip->ip_hl << 2))); 344 345 switch (ip->ip_p) { 346 case IPPROTO_TCP: 347 th = (struct tcphdr *)(ip + 1); 348 /* 349 * Maybe it was set in 350 * libalias... 351 */ 352 th->th_x2 = 0; 353 th->th_sum = cksum; 354 mcl->m_pkthdr.csum_data = 355 offsetof(struct tcphdr, th_sum); 356 break; 357 case IPPROTO_UDP: 358 uh = (struct udphdr *)(ip + 1); 359 uh->uh_sum = cksum; 360 mcl->m_pkthdr.csum_data = 361 offsetof(struct udphdr, uh_sum); 362 break; 363 } 364 /* No hw checksum offloading: do it ourselves */ 365 if ((mcl->m_pkthdr.csum_flags & CSUM_DELAY_DATA) == 0) { 366 in_delayed_cksum(mcl); 367 mcl->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 368 } 369 } 370 args->m = mcl; 371 return (IP_FW_NAT); 372 } 373 374 static struct cfg_nat * 375 lookup_nat(struct nat_list *l, int nat_id) 376 { 377 struct cfg_nat *res; 378 379 LIST_FOREACH(res, l, _next) { 380 if (res->id == nat_id) 381 break; 382 } 383 return res; 384 } 385 386 static int 387 ipfw_nat_cfg(struct sockopt *sopt) 388 { 389 struct cfg_nat *cfg, *ptr; 390 char *buf; 391 struct ip_fw_chain *chain = &V_layer3_chain; 392 size_t len; 393 int gencnt, error = 0; 394 395 len = sopt->sopt_valsize; 396 buf = malloc(len, M_TEMP, M_WAITOK | M_ZERO); 397 if ((error = sooptcopyin(sopt, buf, len, sizeof(struct cfg_nat))) != 0) 398 goto out; 399 400 cfg = (struct cfg_nat *)buf; 401 if (cfg->id < 0) { 402 error = EINVAL; 403 goto out; 404 } 405 406 /* 407 * Find/create nat rule. 408 */ 409 IPFW_WLOCK(chain); 410 gencnt = chain->gencnt; 411 ptr = lookup_nat(&chain->nat, cfg->id); 412 if (ptr == NULL) { 413 IPFW_WUNLOCK(chain); 414 /* New rule: allocate and init new instance. */ 415 ptr = malloc(sizeof(struct cfg_nat), M_IPFW, M_WAITOK | M_ZERO); 416 ptr->lib = LibAliasInit(NULL); 417 LIST_INIT(&ptr->redir_chain); 418 } else { 419 /* Entry already present: temporarily unhook it. */ 420 LIST_REMOVE(ptr, _next); 421 flush_nat_ptrs(chain, cfg->id); 422 IPFW_WUNLOCK(chain); 423 } 424 425 /* 426 * Basic nat configuration. 427 */ 428 ptr->id = cfg->id; 429 /* 430 * XXX - what if this rule doesn't nat any ip and just 431 * redirect? 432 * do we set aliasaddress to 0.0.0.0? 433 */ 434 ptr->ip = cfg->ip; 435 ptr->redir_cnt = cfg->redir_cnt; 436 ptr->mode = cfg->mode; 437 LibAliasSetMode(ptr->lib, cfg->mode, cfg->mode); 438 LibAliasSetAddress(ptr->lib, ptr->ip); 439 memcpy(ptr->if_name, cfg->if_name, IF_NAMESIZE); 440 441 /* 442 * Redir and LSNAT configuration. 443 */ 444 /* Delete old cfgs. */ 445 del_redir_spool_cfg(ptr, &ptr->redir_chain); 446 /* Add new entries. */ 447 add_redir_spool_cfg(&buf[(sizeof(struct cfg_nat))], ptr); 448 449 IPFW_WLOCK(chain); 450 /* Extra check to avoid race with another ipfw_nat_cfg() */ 451 if (gencnt != chain->gencnt && 452 ((cfg = lookup_nat(&chain->nat, ptr->id)) != NULL)) 453 LIST_REMOVE(cfg, _next); 454 LIST_INSERT_HEAD(&chain->nat, ptr, _next); 455 chain->gencnt++; 456 IPFW_WUNLOCK(chain); 457 458 out: 459 free(buf, M_TEMP); 460 return (error); 461 } 462 463 static int 464 ipfw_nat_del(struct sockopt *sopt) 465 { 466 struct cfg_nat *ptr; 467 struct ip_fw_chain *chain = &V_layer3_chain; 468 int i; 469 470 sooptcopyin(sopt, &i, sizeof i, sizeof i); 471 /* XXX validate i */ 472 IPFW_WLOCK(chain); 473 ptr = lookup_nat(&chain->nat, i); 474 if (ptr == NULL) { 475 IPFW_WUNLOCK(chain); 476 return (EINVAL); 477 } 478 LIST_REMOVE(ptr, _next); 479 flush_nat_ptrs(chain, i); 480 IPFW_WUNLOCK(chain); 481 del_redir_spool_cfg(ptr, &ptr->redir_chain); 482 LibAliasUninit(ptr->lib); 483 free(ptr, M_IPFW); 484 return (0); 485 } 486 487 static int 488 ipfw_nat_get_cfg(struct sockopt *sopt) 489 { 490 struct ip_fw_chain *chain = &V_layer3_chain; 491 struct cfg_nat *n; 492 struct cfg_redir *r; 493 struct cfg_spool *s; 494 char *data; 495 int gencnt, nat_cnt, len, error; 496 497 nat_cnt = 0; 498 len = sizeof(nat_cnt); 499 500 IPFW_RLOCK(chain); 501 retry: 502 gencnt = chain->gencnt; 503 /* Estimate memory amount */ 504 LIST_FOREACH(n, &chain->nat, _next) { 505 nat_cnt++; 506 len += sizeof(struct cfg_nat); 507 LIST_FOREACH(r, &n->redir_chain, _next) { 508 len += sizeof(struct cfg_redir); 509 LIST_FOREACH(s, &r->spool_chain, _next) 510 len += sizeof(struct cfg_spool); 511 } 512 } 513 IPFW_RUNLOCK(chain); 514 515 data = malloc(len, M_TEMP, M_WAITOK | M_ZERO); 516 bcopy(&nat_cnt, data, sizeof(nat_cnt)); 517 518 nat_cnt = 0; 519 len = sizeof(nat_cnt); 520 521 IPFW_RLOCK(chain); 522 if (gencnt != chain->gencnt) { 523 free(data, M_TEMP); 524 goto retry; 525 } 526 /* Serialize all the data. */ 527 LIST_FOREACH(n, &chain->nat, _next) { 528 bcopy(n, &data[len], sizeof(struct cfg_nat)); 529 len += sizeof(struct cfg_nat); 530 LIST_FOREACH(r, &n->redir_chain, _next) { 531 bcopy(r, &data[len], sizeof(struct cfg_redir)); 532 len += sizeof(struct cfg_redir); 533 LIST_FOREACH(s, &r->spool_chain, _next) { 534 bcopy(s, &data[len], sizeof(struct cfg_spool)); 535 len += sizeof(struct cfg_spool); 536 } 537 } 538 } 539 IPFW_RUNLOCK(chain); 540 541 error = sooptcopyout(sopt, data, len); 542 free(data, M_TEMP); 543 544 return (error); 545 } 546 547 static int 548 ipfw_nat_get_log(struct sockopt *sopt) 549 { 550 uint8_t *data; 551 struct cfg_nat *ptr; 552 int i, size; 553 struct ip_fw_chain *chain; 554 555 chain = &V_layer3_chain; 556 557 IPFW_RLOCK(chain); 558 /* one pass to count, one to copy the data */ 559 i = 0; 560 LIST_FOREACH(ptr, &chain->nat, _next) { 561 if (ptr->lib->logDesc == NULL) 562 continue; 563 i++; 564 } 565 size = i * (LIBALIAS_BUF_SIZE + sizeof(int)); 566 data = malloc(size, M_IPFW, M_NOWAIT | M_ZERO); 567 if (data == NULL) { 568 IPFW_RUNLOCK(chain); 569 return (ENOSPC); 570 } 571 i = 0; 572 LIST_FOREACH(ptr, &chain->nat, _next) { 573 if (ptr->lib->logDesc == NULL) 574 continue; 575 bcopy(&ptr->id, &data[i], sizeof(int)); 576 i += sizeof(int); 577 bcopy(ptr->lib->logDesc, &data[i], LIBALIAS_BUF_SIZE); 578 i += LIBALIAS_BUF_SIZE; 579 } 580 IPFW_RUNLOCK(chain); 581 sooptcopyout(sopt, data, size); 582 free(data, M_IPFW); 583 return(0); 584 } 585 586 static void 587 ipfw_nat_init(void) 588 { 589 590 IPFW_WLOCK(&V_layer3_chain); 591 /* init ipfw hooks */ 592 ipfw_nat_ptr = ipfw_nat; 593 lookup_nat_ptr = lookup_nat; 594 ipfw_nat_cfg_ptr = ipfw_nat_cfg; 595 ipfw_nat_del_ptr = ipfw_nat_del; 596 ipfw_nat_get_cfg_ptr = ipfw_nat_get_cfg; 597 ipfw_nat_get_log_ptr = ipfw_nat_get_log; 598 IPFW_WUNLOCK(&V_layer3_chain); 599 V_ifaddr_event_tag = EVENTHANDLER_REGISTER( 600 ifaddr_event, ifaddr_change, 601 NULL, EVENTHANDLER_PRI_ANY); 602 } 603 604 static void 605 ipfw_nat_destroy(void) 606 { 607 struct cfg_nat *ptr, *ptr_temp; 608 struct ip_fw_chain *chain; 609 610 chain = &V_layer3_chain; 611 IPFW_WLOCK(chain); 612 LIST_FOREACH_SAFE(ptr, &chain->nat, _next, ptr_temp) { 613 LIST_REMOVE(ptr, _next); 614 del_redir_spool_cfg(ptr, &ptr->redir_chain); 615 LibAliasUninit(ptr->lib); 616 free(ptr, M_IPFW); 617 } 618 EVENTHANDLER_DEREGISTER(ifaddr_event, V_ifaddr_event_tag); 619 flush_nat_ptrs(chain, -1 /* flush all */); 620 /* deregister ipfw_nat */ 621 ipfw_nat_ptr = NULL; 622 lookup_nat_ptr = NULL; 623 ipfw_nat_cfg_ptr = NULL; 624 ipfw_nat_del_ptr = NULL; 625 ipfw_nat_get_cfg_ptr = NULL; 626 ipfw_nat_get_log_ptr = NULL; 627 IPFW_WUNLOCK(chain); 628 } 629 630 static int 631 ipfw_nat_modevent(module_t mod, int type, void *unused) 632 { 633 int err = 0; 634 635 switch (type) { 636 case MOD_LOAD: 637 ipfw_nat_init(); 638 break; 639 640 case MOD_UNLOAD: 641 ipfw_nat_destroy(); 642 break; 643 644 default: 645 return EOPNOTSUPP; 646 break; 647 } 648 return err; 649 } 650 651 static moduledata_t ipfw_nat_mod = { 652 "ipfw_nat", 653 ipfw_nat_modevent, 654 0 655 }; 656 657 DECLARE_MODULE(ipfw_nat, ipfw_nat_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 658 MODULE_DEPEND(ipfw_nat, libalias, 1, 1, 1); 659 MODULE_DEPEND(ipfw_nat, ipfw, 2, 2, 2); 660 MODULE_VERSION(ipfw_nat, 1); 661 /* end of file */ 662