ip_fw_nat.c revision 223080
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: head/sys/netinet/ipfw/ip_fw_nat.c 223080 2011-06-14 13:35:24Z ae $"); 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/ipfw/ip_fw_private.h> 50#include <netinet/tcp.h> 51#include <netinet/udp.h> 52 53#include <machine/in_cksum.h> /* XXX for in_cksum */ 54 55static VNET_DEFINE(eventhandler_tag, ifaddr_event_tag); 56#define V_ifaddr_event_tag VNET(ifaddr_event_tag) 57 58static void 59ifaddr_change(void *arg __unused, struct ifnet *ifp) 60{ 61 struct cfg_nat *ptr; 62 struct ifaddr *ifa; 63 struct ip_fw_chain *chain; 64 65 chain = &V_layer3_chain; 66 IPFW_WLOCK(chain); 67 /* Check every nat entry... */ 68 LIST_FOREACH(ptr, &chain->nat, _next) { 69 /* ...using nic 'ifp->if_xname' as dynamic alias address. */ 70 if (strncmp(ptr->if_name, ifp->if_xname, IF_NAMESIZE) != 0) 71 continue; 72 if_addr_rlock(ifp); 73 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 74 if (ifa->ifa_addr == NULL) 75 continue; 76 if (ifa->ifa_addr->sa_family != AF_INET) 77 continue; 78 ptr->ip = ((struct sockaddr_in *) 79 (ifa->ifa_addr))->sin_addr; 80 LibAliasSetAddress(ptr->lib, ptr->ip); 81 } 82 if_addr_runlock(ifp); 83 } 84 IPFW_WUNLOCK(chain); 85} 86 87/* 88 * delete the pointers for nat entry ix, or all of them if ix < 0 89 */ 90static void 91flush_nat_ptrs(struct ip_fw_chain *chain, const int ix) 92{ 93 int i; 94 ipfw_insn_nat *cmd; 95 96 IPFW_WLOCK_ASSERT(chain); 97 for (i = 0; i < chain->n_rules; i++) { 98 cmd = (ipfw_insn_nat *)ACTION_PTR(chain->map[i]); 99 /* XXX skip log and the like ? */ 100 if (cmd->o.opcode == O_NAT && cmd->nat != NULL && 101 (ix < 0 || cmd->nat->id == ix)) 102 cmd->nat = NULL; 103 } 104} 105 106static void 107del_redir_spool_cfg(struct cfg_nat *n, struct redir_chain *head) 108{ 109 struct cfg_redir *r, *tmp_r; 110 struct cfg_spool *s, *tmp_s; 111 int i, num; 112 113 LIST_FOREACH_SAFE(r, head, _next, tmp_r) { 114 num = 1; /* Number of alias_link to delete. */ 115 switch (r->mode) { 116 case REDIR_PORT: 117 num = r->pport_cnt; 118 /* FALLTHROUGH */ 119 case REDIR_ADDR: 120 case REDIR_PROTO: 121 /* Delete all libalias redirect entry. */ 122 for (i = 0; i < num; i++) 123 LibAliasRedirectDelete(n->lib, r->alink[i]); 124 /* Del spool cfg if any. */ 125 LIST_FOREACH_SAFE(s, &r->spool_chain, _next, tmp_s) { 126 LIST_REMOVE(s, _next); 127 free(s, M_IPFW); 128 } 129 free(r->alink, M_IPFW); 130 LIST_REMOVE(r, _next); 131 free(r, M_IPFW); 132 break; 133 default: 134 printf("unknown redirect mode: %u\n", r->mode); 135 /* XXX - panic?!?!? */ 136 break; 137 } 138 } 139} 140 141static void 142add_redir_spool_cfg(char *buf, struct cfg_nat *ptr) 143{ 144 struct cfg_redir *r, *ser_r; 145 struct cfg_spool *s, *ser_s; 146 int cnt, off, i; 147 148 for (cnt = 0, off = 0; cnt < ptr->redir_cnt; cnt++) { 149 ser_r = (struct cfg_redir *)&buf[off]; 150 r = malloc(SOF_REDIR, M_IPFW, M_WAITOK | M_ZERO); 151 memcpy(r, ser_r, SOF_REDIR); 152 LIST_INIT(&r->spool_chain); 153 off += SOF_REDIR; 154 r->alink = malloc(sizeof(struct alias_link *) * r->pport_cnt, 155 M_IPFW, M_WAITOK | M_ZERO); 156 switch (r->mode) { 157 case REDIR_ADDR: 158 r->alink[0] = LibAliasRedirectAddr(ptr->lib, r->laddr, 159 r->paddr); 160 break; 161 case REDIR_PORT: 162 for (i = 0 ; i < r->pport_cnt; i++) { 163 /* If remotePort is all ports, set it to 0. */ 164 u_short remotePortCopy = r->rport + i; 165 if (r->rport_cnt == 1 && r->rport == 0) 166 remotePortCopy = 0; 167 r->alink[i] = LibAliasRedirectPort(ptr->lib, 168 r->laddr, htons(r->lport + i), r->raddr, 169 htons(remotePortCopy), r->paddr, 170 htons(r->pport + i), r->proto); 171 if (r->alink[i] == NULL) { 172 r->alink[0] = NULL; 173 break; 174 } 175 } 176 break; 177 case REDIR_PROTO: 178 r->alink[0] = LibAliasRedirectProto(ptr->lib ,r->laddr, 179 r->raddr, r->paddr, r->proto); 180 break; 181 default: 182 printf("unknown redirect mode: %u\n", r->mode); 183 break; 184 } 185 /* XXX perhaps return an error instead of panic ? */ 186 if (r->alink[0] == NULL) 187 panic("LibAliasRedirect* returned NULL"); 188 /* LSNAT handling. */ 189 for (i = 0; i < r->spool_cnt; i++) { 190 ser_s = (struct cfg_spool *)&buf[off]; 191 s = malloc(SOF_REDIR, M_IPFW, M_WAITOK | M_ZERO); 192 memcpy(s, ser_s, SOF_SPOOL); 193 LibAliasAddServer(ptr->lib, r->alink[0], 194 s->addr, htons(s->port)); 195 off += SOF_SPOOL; 196 /* Hook spool entry. */ 197 LIST_INSERT_HEAD(&r->spool_chain, s, _next); 198 } 199 /* And finally hook this redir entry. */ 200 LIST_INSERT_HEAD(&ptr->redir_chain, r, _next); 201 } 202} 203 204static int 205ipfw_nat(struct ip_fw_args *args, struct cfg_nat *t, struct mbuf *m) 206{ 207 struct mbuf *mcl; 208 struct ip *ip; 209 /* XXX - libalias duct tape */ 210 int ldt, retval, found; 211 struct ip_fw_chain *chain; 212 char *c; 213 214 ldt = 0; 215 retval = 0; 216 mcl = m_megapullup(m, m->m_pkthdr.len); 217 if (mcl == NULL) { 218 args->m = NULL; 219 return (IP_FW_DENY); 220 } 221 ip = mtod(mcl, struct ip *); 222 223 /* 224 * XXX - Libalias checksum offload 'duct tape': 225 * 226 * locally generated packets have only pseudo-header checksum 227 * calculated and libalias will break it[1], so mark them for 228 * later fix. Moreover there are cases when libalias modifies 229 * tcp packet data[2], mark them for later fix too. 230 * 231 * [1] libalias was never meant to run in kernel, so it does 232 * not have any knowledge about checksum offloading, and 233 * expects a packet with a full internet checksum. 234 * Unfortunately, packets generated locally will have just the 235 * pseudo header calculated, and when libalias tries to adjust 236 * the checksum it will actually compute a wrong value. 237 * 238 * [2] when libalias modifies tcp's data content, full TCP 239 * checksum has to be recomputed: the problem is that 240 * libalias does not have any idea about checksum offloading. 241 * To work around this, we do not do checksumming in LibAlias, 242 * but only mark the packets in th_x2 field. If we receive a 243 * marked packet, we calculate correct checksum for it 244 * aware of offloading. Why such a terrible hack instead of 245 * recalculating checksum for each packet? 246 * Because the previous checksum was not checked! 247 * Recalculating checksums for EVERY packet will hide ALL 248 * transmission errors. Yes, marked packets still suffer from 249 * this problem. But, sigh, natd(8) has this problem, too. 250 * 251 * TODO: -make libalias mbuf aware (so 252 * it can handle delayed checksum and tso) 253 */ 254 255 if (mcl->m_pkthdr.rcvif == NULL && 256 mcl->m_pkthdr.csum_flags & CSUM_DELAY_DATA) 257 ldt = 1; 258 259 c = mtod(mcl, char *); 260 261 /* Check if this is 'global' instance */ 262 if (t == NULL) { 263 if (args->oif == NULL) { 264 /* Wrong direction, skip processing */ 265 args->m = mcl; 266 return (IP_FW_NAT); 267 } 268 269 found = 0; 270 chain = &V_layer3_chain; 271 IPFW_RLOCK(chain); 272 /* Check every nat entry... */ 273 LIST_FOREACH(t, &chain->nat, _next) { 274 if ((t->mode & PKT_ALIAS_SKIP_GLOBAL) != 0) 275 continue; 276 retval = LibAliasOutTry(t->lib, c, 277 mcl->m_len + M_TRAILINGSPACE(mcl), 0); 278 if (retval == PKT_ALIAS_OK) { 279 /* Nat instance recognises state */ 280 found = 1; 281 break; 282 } 283 } 284 IPFW_RUNLOCK(chain); 285 if (found != 1) { 286 /* No instance found, return ignore */ 287 args->m = mcl; 288 return (IP_FW_NAT); 289 } 290 } else { 291 if (args->oif == NULL) 292 retval = LibAliasIn(t->lib, c, 293 mcl->m_len + M_TRAILINGSPACE(mcl)); 294 else 295 retval = LibAliasOut(t->lib, c, 296 mcl->m_len + M_TRAILINGSPACE(mcl)); 297 } 298 299 /* 300 * We drop packet when: 301 * 1. libalias returns PKT_ALIAS_ERROR; 302 * 2. For incoming packets: 303 * a) for unresolved fragments; 304 * b) libalias returns PKT_ALIAS_IGNORED and 305 * PKT_ALIAS_DENY_INCOMING flag is set. 306 */ 307 if (retval == PKT_ALIAS_ERROR || 308 (args->oif == NULL && (retval == PKT_ALIAS_UNRESOLVED_FRAGMENT || 309 (retval == PKT_ALIAS_IGNORED && 310 (t->mode & PKT_ALIAS_DENY_INCOMING) != 0)))) { 311 /* XXX - should i add some logging? */ 312 m_free(mcl); 313 args->m = NULL; 314 return (IP_FW_DENY); 315 } 316 317 if (retval == PKT_ALIAS_RESPOND) 318 m->m_flags |= M_SKIP_FIREWALL; 319 mcl->m_pkthdr.len = mcl->m_len = ntohs(ip->ip_len); 320 321 /* 322 * XXX - libalias checksum offload 323 * 'duct tape' (see above) 324 */ 325 326 if ((ip->ip_off & htons(IP_OFFMASK)) == 0 && 327 ip->ip_p == IPPROTO_TCP) { 328 struct tcphdr *th; 329 330 th = (struct tcphdr *)(ip + 1); 331 if (th->th_x2) 332 ldt = 1; 333 } 334 335 if (ldt) { 336 struct tcphdr *th; 337 struct udphdr *uh; 338 u_short cksum; 339 340 ip->ip_len = ntohs(ip->ip_len); 341 cksum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 342 htons(ip->ip_p + ip->ip_len - (ip->ip_hl << 2))); 343 344 switch (ip->ip_p) { 345 case IPPROTO_TCP: 346 th = (struct tcphdr *)(ip + 1); 347 /* 348 * Maybe it was set in 349 * libalias... 350 */ 351 th->th_x2 = 0; 352 th->th_sum = cksum; 353 mcl->m_pkthdr.csum_data = 354 offsetof(struct tcphdr, th_sum); 355 break; 356 case IPPROTO_UDP: 357 uh = (struct udphdr *)(ip + 1); 358 uh->uh_sum = cksum; 359 mcl->m_pkthdr.csum_data = 360 offsetof(struct udphdr, uh_sum); 361 break; 362 } 363 /* No hw checksum offloading: do it ourselves */ 364 if ((mcl->m_pkthdr.csum_flags & CSUM_DELAY_DATA) == 0) { 365 in_delayed_cksum(mcl); 366 mcl->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 367 } 368 ip->ip_len = htons(ip->ip_len); 369 } 370 args->m = mcl; 371 return (IP_FW_NAT); 372} 373 374static struct cfg_nat * 375lookup_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 386static int 387ipfw_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 458out: 459 free(buf, M_TEMP); 460 return (error); 461} 462 463static int 464ipfw_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 487static int 488ipfw_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); 501retry: 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 547static int 548ipfw_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 586static void 587ipfw_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 604static void 605ipfw_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 630static int 631ipfw_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 651static moduledata_t ipfw_nat_mod = { 652 "ipfw_nat", 653 ipfw_nat_modevent, 654 0 655}; 656 657DECLARE_MODULE(ipfw_nat, ipfw_nat_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 658MODULE_DEPEND(ipfw_nat, libalias, 1, 1, 1); 659MODULE_DEPEND(ipfw_nat, ipfw, 2, 2, 2); 660MODULE_VERSION(ipfw_nat, 1); 661/* end of file */ 662