ip_fw_nat.c revision 200598
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 200598 2009-12-16 03:26:37Z imp $"); 29 30#include <sys/param.h> 31#include <sys/systm.h> 32#include <sys/condvar.h> 33#include <sys/eventhandler.h> 34#include <sys/malloc.h> 35#include <sys/mbuf.h> 36#include <sys/kernel.h> 37#include <sys/lock.h> 38#include <sys/jail.h> 39#include <sys/module.h> 40#include <sys/priv.h> 41#include <sys/proc.h> 42#include <sys/rwlock.h> 43#include <sys/socket.h> 44#include <sys/socketvar.h> 45#include <sys/sysctl.h> 46#include <sys/syslog.h> 47#include <sys/ucred.h> 48 49#define IPFW_INTERNAL /* Access to protected data structures in ip_fw.h. */ 50 51#include <netinet/libalias/alias.h> 52#include <netinet/libalias/alias_local.h> 53 54#include <net/if.h> 55#include <netinet/in.h> 56#include <netinet/ip.h> 57#include <netinet/ip_var.h> 58#include <netinet/ip_icmp.h> 59#include <netinet/ip_fw.h> 60#include <netinet/ipfw/ip_fw_private.h> 61#include <netinet/tcp.h> 62#include <netinet/tcp_timer.h> 63#include <netinet/tcp_var.h> 64#include <netinet/tcpip.h> 65#include <netinet/udp.h> 66#include <netinet/udp_var.h> 67 68#include <machine/in_cksum.h> /* XXX for in_cksum */ 69 70static VNET_DEFINE(eventhandler_tag, ifaddr_event_tag); 71#define V_ifaddr_event_tag VNET(ifaddr_event_tag) 72 73static void 74ifaddr_change(void *arg __unused, struct ifnet *ifp) 75{ 76 struct cfg_nat *ptr; 77 struct ifaddr *ifa; 78 79 IPFW_WLOCK(&V_layer3_chain); 80 /* Check every nat entry... */ 81 LIST_FOREACH(ptr, &V_layer3_chain.nat, _next) { 82 /* ...using nic 'ifp->if_xname' as dynamic alias address. */ 83 if (strncmp(ptr->if_name, ifp->if_xname, IF_NAMESIZE) == 0) { 84 if_addr_rlock(ifp); 85 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 86 if (ifa->ifa_addr == NULL) 87 continue; 88 if (ifa->ifa_addr->sa_family != AF_INET) 89 continue; 90 ptr->ip = ((struct sockaddr_in *) 91 (ifa->ifa_addr))->sin_addr; 92 LibAliasSetAddress(ptr->lib, ptr->ip); 93 } 94 if_addr_runlock(ifp); 95 } 96 } 97 IPFW_WUNLOCK(&V_layer3_chain); 98} 99 100static void 101flush_nat_ptrs(const int i) 102{ 103 struct ip_fw *rule; 104 105 IPFW_WLOCK_ASSERT(&V_layer3_chain); 106 for (rule = V_layer3_chain.rules; rule; rule = rule->next) { 107 ipfw_insn_nat *cmd = (ipfw_insn_nat *)ACTION_PTR(rule); 108 if (cmd->o.opcode != O_NAT) 109 continue; 110 if (cmd->nat != NULL && cmd->nat->id == i) 111 cmd->nat = NULL; 112 } 113} 114 115#define HOOK_NAT(b, p) do { \ 116 IPFW_WLOCK_ASSERT(&V_layer3_chain); \ 117 LIST_INSERT_HEAD(b, p, _next); \ 118 } while (0) 119 120#define UNHOOK_NAT(p) do { \ 121 IPFW_WLOCK_ASSERT(&V_layer3_chain); \ 122 LIST_REMOVE(p, _next); \ 123 } while (0) 124 125#define HOOK_REDIR(b, p) do { \ 126 LIST_INSERT_HEAD(b, p, _next); \ 127 } while (0) 128 129#define HOOK_SPOOL(b, p) do { \ 130 LIST_INSERT_HEAD(b, p, _next); \ 131 } while (0) 132 133static void 134del_redir_spool_cfg(struct cfg_nat *n, struct redir_chain *head) 135{ 136 struct cfg_redir *r, *tmp_r; 137 struct cfg_spool *s, *tmp_s; 138 int i, num; 139 140 LIST_FOREACH_SAFE(r, head, _next, tmp_r) { 141 num = 1; /* Number of alias_link to delete. */ 142 switch (r->mode) { 143 case REDIR_PORT: 144 num = r->pport_cnt; 145 /* FALLTHROUGH */ 146 case REDIR_ADDR: 147 case REDIR_PROTO: 148 /* Delete all libalias redirect entry. */ 149 for (i = 0; i < num; i++) 150 LibAliasRedirectDelete(n->lib, r->alink[i]); 151 /* Del spool cfg if any. */ 152 LIST_FOREACH_SAFE(s, &r->spool_chain, _next, tmp_s) { 153 LIST_REMOVE(s, _next); 154 free(s, M_IPFW); 155 } 156 free(r->alink, M_IPFW); 157 LIST_REMOVE(r, _next); 158 free(r, M_IPFW); 159 break; 160 default: 161 printf("unknown redirect mode: %u\n", r->mode); 162 /* XXX - panic?!?!? */ 163 break; 164 } 165 } 166} 167 168static int 169add_redir_spool_cfg(char *buf, struct cfg_nat *ptr) 170{ 171 struct cfg_redir *r, *ser_r; 172 struct cfg_spool *s, *ser_s; 173 int cnt, off, i; 174 char *panic_err; 175 176 for (cnt = 0, off = 0; cnt < ptr->redir_cnt; cnt++) { 177 ser_r = (struct cfg_redir *)&buf[off]; 178 r = malloc(SOF_REDIR, M_IPFW, M_WAITOK | M_ZERO); 179 memcpy(r, ser_r, SOF_REDIR); 180 LIST_INIT(&r->spool_chain); 181 off += SOF_REDIR; 182 r->alink = malloc(sizeof(struct alias_link *) * r->pport_cnt, 183 M_IPFW, M_WAITOK | M_ZERO); 184 switch (r->mode) { 185 case REDIR_ADDR: 186 r->alink[0] = LibAliasRedirectAddr(ptr->lib, r->laddr, 187 r->paddr); 188 break; 189 case REDIR_PORT: 190 for (i = 0 ; i < r->pport_cnt; i++) { 191 /* If remotePort is all ports, set it to 0. */ 192 u_short remotePortCopy = r->rport + i; 193 if (r->rport_cnt == 1 && r->rport == 0) 194 remotePortCopy = 0; 195 r->alink[i] = LibAliasRedirectPort(ptr->lib, 196 r->laddr, htons(r->lport + i), r->raddr, 197 htons(remotePortCopy), r->paddr, 198 htons(r->pport + i), r->proto); 199 if (r->alink[i] == NULL) { 200 r->alink[0] = NULL; 201 break; 202 } 203 } 204 break; 205 case REDIR_PROTO: 206 r->alink[0] = LibAliasRedirectProto(ptr->lib ,r->laddr, 207 r->raddr, r->paddr, r->proto); 208 break; 209 default: 210 printf("unknown redirect mode: %u\n", r->mode); 211 break; 212 } 213 if (r->alink[0] == NULL) { 214 panic_err = "LibAliasRedirect* returned NULL"; 215 goto bad; 216 } else /* LSNAT handling. */ 217 for (i = 0; i < r->spool_cnt; i++) { 218 ser_s = (struct cfg_spool *)&buf[off]; 219 s = malloc(SOF_REDIR, M_IPFW, 220 M_WAITOK | M_ZERO); 221 memcpy(s, ser_s, SOF_SPOOL); 222 LibAliasAddServer(ptr->lib, r->alink[0], 223 s->addr, htons(s->port)); 224 off += SOF_SPOOL; 225 /* Hook spool entry. */ 226 HOOK_SPOOL(&r->spool_chain, s); 227 } 228 /* And finally hook this redir entry. */ 229 HOOK_REDIR(&ptr->redir_chain, r); 230 } 231 return (1); 232bad: 233 /* something really bad happened: panic! */ 234 panic("%s\n", panic_err); 235} 236 237static int 238ipfw_nat(struct ip_fw_args *args, struct cfg_nat *t, struct mbuf *m) 239{ 240 struct mbuf *mcl; 241 struct ip *ip; 242 /* XXX - libalias duct tape */ 243 int ldt, retval; 244 char *c; 245 246 ldt = 0; 247 retval = 0; 248 if ((mcl = m_megapullup(m, m->m_pkthdr.len)) == 249 NULL) 250 goto badnat; 251 ip = mtod(mcl, struct ip *); 252 if (args->eh == NULL) { 253 ip->ip_len = htons(ip->ip_len); 254 ip->ip_off = htons(ip->ip_off); 255 } 256 257 /* 258 * XXX - Libalias checksum offload 'duct tape': 259 * 260 * locally generated packets have only 261 * pseudo-header checksum calculated 262 * and libalias will screw it[1], so 263 * mark them for later fix. Moreover 264 * there are cases when libalias 265 * modify tcp packet data[2], mark it 266 * for later fix too. 267 * 268 * [1] libalias was never meant to run 269 * in kernel, so it doesn't have any 270 * knowledge about checksum 271 * offloading, and it expects a packet 272 * with a full internet 273 * checksum. Unfortunately, packets 274 * generated locally will have just the 275 * pseudo header calculated, and when 276 * libalias tries to adjust the 277 * checksum it will actually screw it. 278 * 279 * [2] when libalias modify tcp's data 280 * content, full TCP checksum has to 281 * be recomputed: the problem is that 282 * libalias doesn't have any idea 283 * about checksum offloading To 284 * workaround this, we do not do 285 * checksumming in LibAlias, but only 286 * mark the packets in th_x2 field. If 287 * we receive a marked packet, we 288 * calculate correct checksum for it 289 * aware of offloading. Why such a 290 * terrible hack instead of 291 * recalculating checksum for each 292 * packet? Because the previous 293 * checksum was not checked! 294 * Recalculating checksums for EVERY 295 * packet will hide ALL transmission 296 * errors. Yes, marked packets still 297 * suffer from this problem. But, 298 * sigh, natd(8) has this problem, 299 * too. 300 * 301 * TODO: -make libalias mbuf aware (so 302 * it can handle delayed checksum and tso) 303 */ 304 305 if (mcl->m_pkthdr.rcvif == NULL && 306 mcl->m_pkthdr.csum_flags & 307 CSUM_DELAY_DATA) 308 ldt = 1; 309 310 c = mtod(mcl, char *); 311 if (args->oif == NULL) 312 retval = LibAliasIn(t->lib, c, 313 mcl->m_len + M_TRAILINGSPACE(mcl)); 314 else 315 retval = LibAliasOut(t->lib, c, 316 mcl->m_len + M_TRAILINGSPACE(mcl)); 317 if (retval == PKT_ALIAS_RESPOND) { 318 m->m_flags |= M_SKIP_FIREWALL; 319 retval = PKT_ALIAS_OK; 320 } 321 if (retval != PKT_ALIAS_OK && 322 retval != PKT_ALIAS_FOUND_HEADER_FRAGMENT) { 323 /* XXX - should i add some logging? */ 324 m_free(mcl); 325 badnat: 326 args->m = NULL; 327 return (IP_FW_DENY); 328 } 329 mcl->m_pkthdr.len = mcl->m_len = 330 ntohs(ip->ip_len); 331 332 /* 333 * XXX - libalias checksum offload 334 * 'duct tape' (see above) 335 */ 336 337 if ((ip->ip_off & htons(IP_OFFMASK)) == 0 && 338 ip->ip_p == IPPROTO_TCP) { 339 struct tcphdr *th; 340 341 th = (struct tcphdr *)(ip + 1); 342 if (th->th_x2) 343 ldt = 1; 344 } 345 346 if (ldt) { 347 struct tcphdr *th; 348 struct udphdr *uh; 349 u_short cksum; 350 351 ip->ip_len = ntohs(ip->ip_len); 352 cksum = in_pseudo( 353 ip->ip_src.s_addr, 354 ip->ip_dst.s_addr, 355 htons(ip->ip_p + ip->ip_len - (ip->ip_hl << 2)) 356 ); 357 358 switch (ip->ip_p) { 359 case IPPROTO_TCP: 360 th = (struct tcphdr *)(ip + 1); 361 /* 362 * Maybe it was set in 363 * libalias... 364 */ 365 th->th_x2 = 0; 366 th->th_sum = cksum; 367 mcl->m_pkthdr.csum_data = 368 offsetof(struct tcphdr, th_sum); 369 break; 370 case IPPROTO_UDP: 371 uh = (struct udphdr *)(ip + 1); 372 uh->uh_sum = cksum; 373 mcl->m_pkthdr.csum_data = 374 offsetof(struct udphdr, uh_sum); 375 break; 376 } 377 /* 378 * No hw checksum offloading: do it 379 * by ourself. 380 */ 381 if ((mcl->m_pkthdr.csum_flags & 382 CSUM_DELAY_DATA) == 0) { 383 in_delayed_cksum(mcl); 384 mcl->m_pkthdr.csum_flags &= 385 ~CSUM_DELAY_DATA; 386 } 387 ip->ip_len = htons(ip->ip_len); 388 } 389 390 if (args->eh == NULL) { 391 ip->ip_len = ntohs(ip->ip_len); 392 ip->ip_off = ntohs(ip->ip_off); 393 } 394 395 args->m = mcl; 396 return (IP_FW_NAT); 397} 398 399#define LOOKUP_NAT(head, i, p) do { \ 400 LIST_FOREACH((p), head, _next) { \ 401 if ((p)->id == (i)) { \ 402 break; \ 403 } \ 404 } \ 405 } while (0) 406 407static struct cfg_nat * 408lookup_nat(struct nat_list *l, int nat_id) 409{ 410 struct cfg_nat *res; 411 412 LOOKUP_NAT(l, nat_id, res); 413 return res; 414} 415 416static int 417ipfw_nat_cfg(struct sockopt *sopt) 418{ 419 struct cfg_nat *ptr, *ser_n; 420 char *buf; 421 422 buf = malloc(NAT_BUF_LEN, M_IPFW, M_WAITOK | M_ZERO); 423 sooptcopyin(sopt, buf, NAT_BUF_LEN, 424 sizeof(struct cfg_nat)); 425 ser_n = (struct cfg_nat *)buf; 426 427 /* 428 * Find/create nat rule. 429 */ 430 IPFW_WLOCK(&V_layer3_chain); 431 LOOKUP_NAT(&V_layer3_chain.nat, ser_n->id, ptr); 432 if (ptr == NULL) { 433 /* New rule: allocate and init new instance. */ 434 ptr = malloc(sizeof(struct cfg_nat), 435 M_IPFW, M_NOWAIT | M_ZERO); 436 if (ptr == NULL) { 437 IPFW_WUNLOCK(&V_layer3_chain); 438 free(buf, M_IPFW); 439 return (ENOSPC); 440 } 441 ptr->lib = LibAliasInit(NULL); 442 if (ptr->lib == NULL) { 443 IPFW_WUNLOCK(&V_layer3_chain); 444 free(ptr, M_IPFW); 445 free(buf, M_IPFW); 446 return (EINVAL); 447 } 448 LIST_INIT(&ptr->redir_chain); 449 } else { 450 /* Entry already present: temporarly unhook it. */ 451 UNHOOK_NAT(ptr); 452 flush_nat_ptrs(ser_n->id); 453 } 454 IPFW_WUNLOCK(&V_layer3_chain); 455 456 /* 457 * Basic nat configuration. 458 */ 459 ptr->id = ser_n->id; 460 /* 461 * XXX - what if this rule doesn't nat any ip and just 462 * redirect? 463 * do we set aliasaddress to 0.0.0.0? 464 */ 465 ptr->ip = ser_n->ip; 466 ptr->redir_cnt = ser_n->redir_cnt; 467 ptr->mode = ser_n->mode; 468 LibAliasSetMode(ptr->lib, ser_n->mode, ser_n->mode); 469 LibAliasSetAddress(ptr->lib, ptr->ip); 470 memcpy(ptr->if_name, ser_n->if_name, IF_NAMESIZE); 471 472 /* 473 * Redir and LSNAT configuration. 474 */ 475 /* Delete old cfgs. */ 476 del_redir_spool_cfg(ptr, &ptr->redir_chain); 477 /* Add new entries. */ 478 add_redir_spool_cfg(&buf[(sizeof(struct cfg_nat))], ptr); 479 free(buf, M_IPFW); 480 IPFW_WLOCK(&V_layer3_chain); 481 HOOK_NAT(&V_layer3_chain.nat, ptr); 482 IPFW_WUNLOCK(&V_layer3_chain); 483 return (0); 484} 485 486static int 487ipfw_nat_del(struct sockopt *sopt) 488{ 489 struct cfg_nat *ptr; 490 int i; 491 492 sooptcopyin(sopt, &i, sizeof i, sizeof i); 493 IPFW_WLOCK(&V_layer3_chain); 494 LOOKUP_NAT(&V_layer3_chain.nat, i, ptr); 495 if (ptr == NULL) { 496 IPFW_WUNLOCK(&V_layer3_chain); 497 return (EINVAL); 498 } 499 UNHOOK_NAT(ptr); 500 flush_nat_ptrs(i); 501 IPFW_WUNLOCK(&V_layer3_chain); 502 del_redir_spool_cfg(ptr, &ptr->redir_chain); 503 LibAliasUninit(ptr->lib); 504 free(ptr, M_IPFW); 505 return (0); 506} 507 508static int 509ipfw_nat_get_cfg(struct sockopt *sopt) 510{ 511 uint8_t *data; 512 struct cfg_nat *n; 513 struct cfg_redir *r; 514 struct cfg_spool *s; 515 int nat_cnt, off; 516 517 nat_cnt = 0; 518 off = sizeof(nat_cnt); 519 520 data = malloc(NAT_BUF_LEN, M_IPFW, M_WAITOK | M_ZERO); 521 IPFW_RLOCK(&V_layer3_chain); 522 /* Serialize all the data. */ 523 LIST_FOREACH(n, &V_layer3_chain.nat, _next) { 524 nat_cnt++; 525 if (off + SOF_NAT < NAT_BUF_LEN) { 526 bcopy(n, &data[off], SOF_NAT); 527 off += SOF_NAT; 528 LIST_FOREACH(r, &n->redir_chain, _next) { 529 if (off + SOF_REDIR < NAT_BUF_LEN) { 530 bcopy(r, &data[off], 531 SOF_REDIR); 532 off += SOF_REDIR; 533 LIST_FOREACH(s, &r->spool_chain, 534 _next) { 535 if (off + SOF_SPOOL < 536 NAT_BUF_LEN) { 537 bcopy(s, &data[off], 538 SOF_SPOOL); 539 off += SOF_SPOOL; 540 } else 541 goto nospace; 542 } 543 } else 544 goto nospace; 545 } 546 } else 547 goto nospace; 548 } 549 bcopy(&nat_cnt, data, sizeof(nat_cnt)); 550 IPFW_RUNLOCK(&V_layer3_chain); 551 sooptcopyout(sopt, data, NAT_BUF_LEN); 552 free(data, M_IPFW); 553 return (0); 554nospace: 555 IPFW_RUNLOCK(&V_layer3_chain); 556 printf("serialized data buffer not big enough:" 557 "please increase NAT_BUF_LEN\n"); 558 free(data, M_IPFW); 559 return (ENOSPC); 560} 561 562static int 563ipfw_nat_get_log(struct sockopt *sopt) 564{ 565 uint8_t *data; 566 struct cfg_nat *ptr; 567 int i, size, cnt, sof; 568 569 data = NULL; 570 sof = LIBALIAS_BUF_SIZE; 571 cnt = 0; 572 573 IPFW_RLOCK(&V_layer3_chain); 574 size = i = 0; 575 LIST_FOREACH(ptr, &V_layer3_chain.nat, _next) { 576 if (ptr->lib->logDesc == NULL) 577 continue; 578 cnt++; 579 size = cnt * (sof + sizeof(int)); 580 data = realloc(data, size, M_IPFW, M_NOWAIT | M_ZERO); 581 if (data == NULL) { 582 IPFW_RUNLOCK(&V_layer3_chain); 583 return (ENOSPC); 584 } 585 bcopy(&ptr->id, &data[i], sizeof(int)); 586 i += sizeof(int); 587 bcopy(ptr->lib->logDesc, &data[i], sof); 588 i += sof; 589 } 590 IPFW_RUNLOCK(&V_layer3_chain); 591 sooptcopyout(sopt, data, size); 592 free(data, M_IPFW); 593 return(0); 594} 595 596static void 597ipfw_nat_init(void) 598{ 599 600 IPFW_WLOCK(&V_layer3_chain); 601 /* init ipfw hooks */ 602 ipfw_nat_ptr = ipfw_nat; 603 lookup_nat_ptr = lookup_nat; 604 ipfw_nat_cfg_ptr = ipfw_nat_cfg; 605 ipfw_nat_del_ptr = ipfw_nat_del; 606 ipfw_nat_get_cfg_ptr = ipfw_nat_get_cfg; 607 ipfw_nat_get_log_ptr = ipfw_nat_get_log; 608 IPFW_WUNLOCK(&V_layer3_chain); 609 V_ifaddr_event_tag = EVENTHANDLER_REGISTER(ifaddr_event, ifaddr_change, 610 NULL, EVENTHANDLER_PRI_ANY); 611} 612 613static void 614ipfw_nat_destroy(void) 615{ 616 struct ip_fw *rule; 617 struct cfg_nat *ptr, *ptr_temp; 618 619 IPFW_WLOCK(&V_layer3_chain); 620 LIST_FOREACH_SAFE(ptr, &V_layer3_chain.nat, _next, ptr_temp) { 621 LIST_REMOVE(ptr, _next); 622 del_redir_spool_cfg(ptr, &ptr->redir_chain); 623 LibAliasUninit(ptr->lib); 624 free(ptr, M_IPFW); 625 } 626 EVENTHANDLER_DEREGISTER(ifaddr_event, V_ifaddr_event_tag); 627 /* flush all nat ptrs */ 628 for (rule = V_layer3_chain.rules; rule; rule = rule->next) { 629 ipfw_insn_nat *cmd = (ipfw_insn_nat *)ACTION_PTR(rule); 630 if (cmd->o.opcode == O_NAT) 631 cmd->nat = NULL; 632 } 633 /* deregister ipfw_nat */ 634 ipfw_nat_ptr = NULL; 635 lookup_nat_ptr = NULL; 636 ipfw_nat_cfg_ptr = NULL; 637 ipfw_nat_del_ptr = NULL; 638 ipfw_nat_get_cfg_ptr = NULL; 639 ipfw_nat_get_log_ptr = NULL; 640 IPFW_WUNLOCK(&V_layer3_chain); 641} 642 643static int 644ipfw_nat_modevent(module_t mod, int type, void *unused) 645{ 646 int err = 0; 647 648 switch (type) { 649 case MOD_LOAD: 650 ipfw_nat_init(); 651 break; 652 653 case MOD_UNLOAD: 654 ipfw_nat_destroy(); 655 break; 656 657 default: 658 return EOPNOTSUPP; 659 break; 660 } 661 return err; 662} 663 664static moduledata_t ipfw_nat_mod = { 665 "ipfw_nat", 666 ipfw_nat_modevent, 667 0 668}; 669 670DECLARE_MODULE(ipfw_nat, ipfw_nat_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 671MODULE_DEPEND(ipfw_nat, libalias, 1, 1, 1); 672MODULE_DEPEND(ipfw_nat, ipfw, 2, 2, 2); 673MODULE_VERSION(ipfw_nat, 1); 674