1 /* 2 * Copyright (C) 1995-2004 by Darren Reed. 3 * 4 * See the IPFILTER.LICENCE file for details on licencing. 5 * 6 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 7 * Use is subject to license terms. 8 */ 9 10 #if defined(KERNEL) || defined(_KERNEL) 11 # undef KERNEL 12 # undef _KERNEL 13 # define KERNEL 1 14 # define _KERNEL 1 15 #endif 16 #include <sys/errno.h> 17 #include <sys/types.h> 18 #include <sys/param.h> 19 #include <sys/time.h> 20 #include <sys/file.h> 21 #if defined(__NetBSD__) && (NetBSD >= 199905) && !defined(IPFILTER_LKM) && \ 22 defined(_KERNEL) 23 # include "opt_ipfilter_log.h" 24 #endif 25 #if !defined(_KERNEL) 26 # include <stdio.h> 27 # include <string.h> 28 # include <stdlib.h> 29 # define _KERNEL 30 # ifdef __OpenBSD__ 31 struct file; 32 # endif 33 # include <sys/uio.h> 34 # undef _KERNEL 35 #endif 36 #if defined(_KERNEL) && (__FreeBSD_version >= 220000) 37 # include <sys/filio.h> 38 # include <sys/fcntl.h> 39 #else 40 # include <sys/ioctl.h> 41 #endif 42 #if !defined(AIX) 43 # include <sys/fcntl.h> 44 #endif 45 #if !defined(linux) 46 # include <sys/protosw.h> 47 #endif 48 #include <sys/socket.h> 49 #if defined(_KERNEL) 50 # include <sys/systm.h> 51 # if !defined(__SVR4) && !defined(__svr4__) 52 # include <sys/mbuf.h> 53 # endif 54 #endif 55 #if defined(__SVR4) || defined(__svr4__) 56 # include <sys/filio.h> 57 # include <sys/byteorder.h> 58 # ifdef _KERNEL 59 # include <sys/dditypes.h> 60 # endif 61 # include <sys/stream.h> 62 # include <sys/kmem.h> 63 #endif 64 #if __FreeBSD_version >= 300000 65 # include <sys/queue.h> 66 #endif 67 #include <net/if.h> 68 #if __FreeBSD_version >= 300000 69 # include <net/if_var.h> 70 # if defined(_KERNEL) && !defined(IPFILTER_LKM) 71 # include "opt_ipfilter.h" 72 # endif 73 #endif 74 #ifdef sun 75 # include <net/af.h> 76 #endif 77 #include <net/route.h> 78 #include <netinet/in.h> 79 #include <netinet/in_systm.h> 80 #include <netinet/ip.h> 81 82 #ifdef RFC1825 83 # include <vpn/md5.h> 84 # include <vpn/ipsec.h> 85 extern struct ifnet vpnif; 86 #endif 87 88 #if !defined(linux) 89 # include <netinet/ip_var.h> 90 #endif 91 #include <netinet/tcp.h> 92 #include <netinet/udp.h> 93 #include <netinet/ip_icmp.h> 94 #include "netinet/ip_compat.h" 95 #include <netinet/tcpip.h> 96 #include "netinet/ip_fil.h" 97 #include "netinet/ip_nat.h" 98 #include "netinet/ip_frag.h" 99 #include "netinet/ip_state.h" 100 #include "netinet/ip_proxy.h" 101 #include "netinet/ipf_stack.h" 102 #ifdef IPFILTER_SYNC 103 #include "netinet/ip_sync.h" 104 #endif 105 #if (__FreeBSD_version >= 300000) 106 # include <sys/malloc.h> 107 #endif 108 /* END OF INCLUDES */ 109 110 #undef SOCKADDR_IN 111 #define SOCKADDR_IN struct sockaddr_in 112 113 #if !defined(lint) 114 static const char sccsid[] = "@(#)ip_nat.c 1.11 6/5/96 (C) 1995 Darren Reed"; 115 static const char rcsid[] = "@(#)$Id: ip_nat.c,v 2.195.2.42 2005/08/11 19:51:36 darrenr Exp $"; 116 #endif 117 118 119 /* ======================================================================== */ 120 /* How the NAT is organised and works. */ 121 /* */ 122 /* Inside (interface y) NAT Outside (interface x) */ 123 /* -------------------- -+- ------------------------------------- */ 124 /* Packet going | out, processsed by fr_checknatout() for x */ 125 /* ------------> | ------------> */ 126 /* src=10.1.1.1 | src=192.1.1.1 */ 127 /* | */ 128 /* | in, processed by fr_checknatin() for x */ 129 /* <------------ | <------------ */ 130 /* dst=10.1.1.1 | dst=192.1.1.1 */ 131 /* -------------------- -+- ------------------------------------- */ 132 /* fr_checknatout() - changes ip_src and if required, sport */ 133 /* - creates a new mapping, if required. */ 134 /* fr_checknatin() - changes ip_dst and if required, dport */ 135 /* */ 136 /* In the NAT table, internal source is recorded as "in" and externally */ 137 /* seen as "out". */ 138 /* ======================================================================== */ 139 140 141 static int nat_clearlist __P((ipf_stack_t *)); 142 static void nat_addnat __P((struct ipnat *, ipf_stack_t *)); 143 static void nat_addrdr __P((struct ipnat *, ipf_stack_t *)); 144 static int fr_natgetent __P((caddr_t, ipf_stack_t *)); 145 static int fr_natgetsz __P((caddr_t, ipf_stack_t *)); 146 static int fr_natputent __P((caddr_t, int, ipf_stack_t *)); 147 static void nat_tabmove __P((nat_t *, ipf_stack_t *)); 148 static int nat_match __P((fr_info_t *, ipnat_t *)); 149 static INLINE int nat_newmap __P((fr_info_t *, nat_t *, natinfo_t *)); 150 static INLINE int nat_newrdr __P((fr_info_t *, nat_t *, natinfo_t *)); 151 static hostmap_t *nat_hostmap __P((ipnat_t *, struct in_addr, 152 struct in_addr, struct in_addr, u_32_t, 153 ipf_stack_t *)); 154 static INLINE int nat_icmpquerytype4 __P((int)); 155 static int nat_ruleaddrinit __P((ipnat_t *)); 156 static int nat_siocaddnat __P((ipnat_t *, ipnat_t **, int, ipf_stack_t *)); 157 static void nat_siocdelnat __P((ipnat_t *, ipnat_t **, int, ipf_stack_t *)); 158 static INLINE int nat_icmperrortype4 __P((int)); 159 static INLINE int nat_finalise __P((fr_info_t *, nat_t *, natinfo_t *, 160 tcphdr_t *, nat_t **, int)); 161 static INLINE int nat_resolverule __P((ipnat_t *, ipf_stack_t *)); 162 static void nat_mssclamp __P((tcphdr_t *, u_32_t, u_short *)); 163 static int nat_getnext __P((ipftoken_t *, ipfgeniter_t *, ipf_stack_t *)); 164 static int nat_iterator __P((ipftoken_t *, ipfgeniter_t *, ipf_stack_t *)); 165 static int nat_flushtable __P((int, ipf_stack_t *)); 166 167 #define NAT_HAS_L4_CHANGED(n) \ 168 (((n)->nat_flags & (IPN_TCPUDPICMP)) && \ 169 (n)->nat_inport != (n)->nat_outport) 170 171 172 /* ------------------------------------------------------------------------ */ 173 /* Function: fr_natinit */ 174 /* Returns: int - 0 == success, -1 == failure */ 175 /* Parameters: Nil */ 176 /* */ 177 /* Initialise all of the NAT locks, tables and other structures. */ 178 /* ------------------------------------------------------------------------ */ 179 int fr_natinit(ifs) 180 ipf_stack_t *ifs; 181 { 182 int i; 183 184 KMALLOCS(ifs->ifs_nat_table[0], nat_t **, 185 sizeof(nat_t *) * ifs->ifs_ipf_nattable_sz); 186 if (ifs->ifs_nat_table[0] != NULL) 187 bzero((char *)ifs->ifs_nat_table[0], 188 ifs->ifs_ipf_nattable_sz * sizeof(nat_t *)); 189 else 190 return -1; 191 192 KMALLOCS(ifs->ifs_nat_table[1], nat_t **, 193 sizeof(nat_t *) * ifs->ifs_ipf_nattable_sz); 194 if (ifs->ifs_nat_table[1] != NULL) 195 bzero((char *)ifs->ifs_nat_table[1], 196 ifs->ifs_ipf_nattable_sz * sizeof(nat_t *)); 197 else 198 return -2; 199 200 KMALLOCS(ifs->ifs_nat_rules, ipnat_t **, 201 sizeof(ipnat_t *) * ifs->ifs_ipf_natrules_sz); 202 if (ifs->ifs_nat_rules != NULL) 203 bzero((char *)ifs->ifs_nat_rules, 204 ifs->ifs_ipf_natrules_sz * sizeof(ipnat_t *)); 205 else 206 return -3; 207 208 KMALLOCS(ifs->ifs_rdr_rules, ipnat_t **, 209 sizeof(ipnat_t *) * ifs->ifs_ipf_rdrrules_sz); 210 if (ifs->ifs_rdr_rules != NULL) 211 bzero((char *)ifs->ifs_rdr_rules, 212 ifs->ifs_ipf_rdrrules_sz * sizeof(ipnat_t *)); 213 else 214 return -4; 215 216 KMALLOCS(ifs->ifs_maptable, hostmap_t **, 217 sizeof(hostmap_t *) * ifs->ifs_ipf_hostmap_sz); 218 if (ifs->ifs_maptable != NULL) 219 bzero((char *)ifs->ifs_maptable, 220 sizeof(hostmap_t *) * ifs->ifs_ipf_hostmap_sz); 221 else 222 return -5; 223 224 ifs->ifs_ipf_hm_maplist = NULL; 225 226 KMALLOCS(ifs->ifs_nat_stats.ns_bucketlen[0], u_long *, 227 ifs->ifs_ipf_nattable_sz * sizeof(u_long)); 228 if (ifs->ifs_nat_stats.ns_bucketlen[0] == NULL) 229 return -1; 230 bzero((char *)ifs->ifs_nat_stats.ns_bucketlen[0], 231 ifs->ifs_ipf_nattable_sz * sizeof(u_long)); 232 233 KMALLOCS(ifs->ifs_nat_stats.ns_bucketlen[1], u_long *, 234 ifs->ifs_ipf_nattable_sz * sizeof(u_long)); 235 if (ifs->ifs_nat_stats.ns_bucketlen[1] == NULL) 236 return -1; 237 bzero((char *)ifs->ifs_nat_stats.ns_bucketlen[1], 238 ifs->ifs_ipf_nattable_sz * sizeof(u_long)); 239 240 if (ifs->ifs_fr_nat_maxbucket == 0) { 241 for (i = ifs->ifs_ipf_nattable_sz; i > 0; i >>= 1) 242 ifs->ifs_fr_nat_maxbucket++; 243 ifs->ifs_fr_nat_maxbucket *= 2; 244 } 245 246 fr_sttab_init(ifs->ifs_nat_tqb, ifs); 247 /* 248 * Increase this because we may have "keep state" following this too 249 * and packet storms can occur if this is removed too quickly. 250 */ 251 ifs->ifs_nat_tqb[IPF_TCPS_CLOSED].ifq_ttl = ifs->ifs_fr_tcplastack; 252 ifs->ifs_nat_tqb[IPF_TCP_NSTATES - 1].ifq_next = &ifs->ifs_nat_udptq; 253 ifs->ifs_nat_udptq.ifq_ttl = ifs->ifs_fr_defnatage; 254 ifs->ifs_nat_udptq.ifq_ref = 1; 255 ifs->ifs_nat_udptq.ifq_head = NULL; 256 ifs->ifs_nat_udptq.ifq_tail = &ifs->ifs_nat_udptq.ifq_head; 257 MUTEX_INIT(&ifs->ifs_nat_udptq.ifq_lock, "nat ipftq udp tab"); 258 ifs->ifs_nat_udptq.ifq_next = &ifs->ifs_nat_icmptq; 259 ifs->ifs_nat_icmptq.ifq_ttl = ifs->ifs_fr_defnaticmpage; 260 ifs->ifs_nat_icmptq.ifq_ref = 1; 261 ifs->ifs_nat_icmptq.ifq_head = NULL; 262 ifs->ifs_nat_icmptq.ifq_tail = &ifs->ifs_nat_icmptq.ifq_head; 263 MUTEX_INIT(&ifs->ifs_nat_icmptq.ifq_lock, "nat icmp ipftq tab"); 264 ifs->ifs_nat_icmptq.ifq_next = &ifs->ifs_nat_iptq; 265 ifs->ifs_nat_iptq.ifq_ttl = ifs->ifs_fr_defnatipage; 266 ifs->ifs_nat_iptq.ifq_ref = 1; 267 ifs->ifs_nat_iptq.ifq_head = NULL; 268 ifs->ifs_nat_iptq.ifq_tail = &ifs->ifs_nat_iptq.ifq_head; 269 MUTEX_INIT(&ifs->ifs_nat_iptq.ifq_lock, "nat ip ipftq tab"); 270 ifs->ifs_nat_iptq.ifq_next = NULL; 271 272 for (i = 0; i < IPF_TCP_NSTATES; i++) { 273 if (ifs->ifs_nat_tqb[i].ifq_ttl < ifs->ifs_fr_defnaticmpage) 274 ifs->ifs_nat_tqb[i].ifq_ttl = ifs->ifs_fr_defnaticmpage; 275 #ifdef LARGE_NAT 276 else if (ifs->ifs_nat_tqb[i].ifq_ttl > ifs->ifs_fr_defnatage) 277 ifs->ifs_nat_tqb[i].ifq_ttl = ifs->ifs_fr_defnatage; 278 #endif 279 } 280 281 /* 282 * Increase this because we may have "keep state" following 283 * this too and packet storms can occur if this is removed 284 * too quickly. 285 */ 286 ifs->ifs_nat_tqb[IPF_TCPS_CLOSED].ifq_ttl = 287 ifs->ifs_nat_tqb[IPF_TCPS_LAST_ACK].ifq_ttl; 288 289 RWLOCK_INIT(&ifs->ifs_ipf_nat, "ipf IP NAT rwlock"); 290 RWLOCK_INIT(&ifs->ifs_ipf_natfrag, "ipf IP NAT-Frag rwlock"); 291 MUTEX_INIT(&ifs->ifs_ipf_nat_new, "ipf nat new mutex"); 292 MUTEX_INIT(&ifs->ifs_ipf_natio, "ipf nat io mutex"); 293 294 ifs->ifs_fr_nat_init = 1; 295 ifs->ifs_nat_last_force_flush = ifs->ifs_fr_ticks; 296 return 0; 297 } 298 299 300 /* ------------------------------------------------------------------------ */ 301 /* Function: nat_addrdr */ 302 /* Returns: Nil */ 303 /* Parameters: n(I) - pointer to NAT rule to add */ 304 /* */ 305 /* Adds a redirect rule to the hash table of redirect rules and the list of */ 306 /* loaded NAT rules. Updates the bitmask indicating which netmasks are in */ 307 /* use by redirect rules. */ 308 /* ------------------------------------------------------------------------ */ 309 static void nat_addrdr(n, ifs) 310 ipnat_t *n; 311 ipf_stack_t *ifs; 312 { 313 ipnat_t **np; 314 u_32_t j; 315 u_int hv; 316 int k; 317 318 k = count4bits(n->in_outmsk); 319 if ((k >= 0) && (k != 32)) 320 ifs->ifs_rdr_masks |= 1 << k; 321 j = (n->in_outip & n->in_outmsk); 322 hv = NAT_HASH_FN(j, 0, ifs->ifs_ipf_rdrrules_sz); 323 np = ifs->ifs_rdr_rules + hv; 324 while (*np != NULL) 325 np = &(*np)->in_rnext; 326 n->in_rnext = NULL; 327 n->in_prnext = np; 328 n->in_hv = hv; 329 *np = n; 330 } 331 332 333 /* ------------------------------------------------------------------------ */ 334 /* Function: nat_addnat */ 335 /* Returns: Nil */ 336 /* Parameters: n(I) - pointer to NAT rule to add */ 337 /* */ 338 /* Adds a NAT map rule to the hash table of rules and the list of loaded */ 339 /* NAT rules. Updates the bitmask indicating which netmasks are in use by */ 340 /* redirect rules. */ 341 /* ------------------------------------------------------------------------ */ 342 static void nat_addnat(n, ifs) 343 ipnat_t *n; 344 ipf_stack_t *ifs; 345 { 346 ipnat_t **np; 347 u_32_t j; 348 u_int hv; 349 int k; 350 351 k = count4bits(n->in_inmsk); 352 if ((k >= 0) && (k != 32)) 353 ifs->ifs_nat_masks |= 1 << k; 354 j = (n->in_inip & n->in_inmsk); 355 hv = NAT_HASH_FN(j, 0, ifs->ifs_ipf_natrules_sz); 356 np = ifs->ifs_nat_rules + hv; 357 while (*np != NULL) 358 np = &(*np)->in_mnext; 359 n->in_mnext = NULL; 360 n->in_pmnext = np; 361 n->in_hv = hv; 362 *np = n; 363 } 364 365 366 /* ------------------------------------------------------------------------ */ 367 /* Function: nat_delrdr */ 368 /* Returns: Nil */ 369 /* Parameters: n(I) - pointer to NAT rule to delete */ 370 /* */ 371 /* Removes a redirect rule from the hash table of redirect rules. */ 372 /* ------------------------------------------------------------------------ */ 373 void nat_delrdr(n) 374 ipnat_t *n; 375 { 376 if (n->in_rnext) 377 n->in_rnext->in_prnext = n->in_prnext; 378 *n->in_prnext = n->in_rnext; 379 } 380 381 382 /* ------------------------------------------------------------------------ */ 383 /* Function: nat_delnat */ 384 /* Returns: Nil */ 385 /* Parameters: n(I) - pointer to NAT rule to delete */ 386 /* */ 387 /* Removes a NAT map rule from the hash table of NAT map rules. */ 388 /* ------------------------------------------------------------------------ */ 389 void nat_delnat(n) 390 ipnat_t *n; 391 { 392 if (n->in_mnext != NULL) 393 n->in_mnext->in_pmnext = n->in_pmnext; 394 *n->in_pmnext = n->in_mnext; 395 } 396 397 398 /* ------------------------------------------------------------------------ */ 399 /* Function: nat_hostmap */ 400 /* Returns: struct hostmap* - NULL if no hostmap could be created, */ 401 /* else a pointer to the hostmapping to use */ 402 /* Parameters: np(I) - pointer to NAT rule */ 403 /* real(I) - real IP address */ 404 /* map(I) - mapped IP address */ 405 /* port(I) - destination port number */ 406 /* Write Locks: ipf_nat */ 407 /* */ 408 /* Check if an ip address has already been allocated for a given mapping */ 409 /* that is not doing port based translation. If is not yet allocated, then */ 410 /* create a new entry if a non-NULL NAT rule pointer has been supplied. */ 411 /* ------------------------------------------------------------------------ */ 412 static struct hostmap *nat_hostmap(np, src, dst, map, port, ifs) 413 ipnat_t *np; 414 struct in_addr src; 415 struct in_addr dst; 416 struct in_addr map; 417 u_32_t port; 418 ipf_stack_t *ifs; 419 { 420 hostmap_t *hm; 421 u_int hv; 422 423 hv = (src.s_addr ^ dst.s_addr); 424 hv += src.s_addr; 425 hv += dst.s_addr; 426 hv %= HOSTMAP_SIZE; 427 for (hm = ifs->ifs_maptable[hv]; hm; hm = hm->hm_next) 428 if ((hm->hm_srcip.s_addr == src.s_addr) && 429 (hm->hm_dstip.s_addr == dst.s_addr) && 430 ((np == NULL) || (np == hm->hm_ipnat)) && 431 ((port == 0) || (port == hm->hm_port))) { 432 hm->hm_ref++; 433 return hm; 434 } 435 436 if (np == NULL) 437 return NULL; 438 439 KMALLOC(hm, hostmap_t *); 440 if (hm) { 441 hm->hm_hnext = ifs->ifs_ipf_hm_maplist; 442 hm->hm_phnext = &ifs->ifs_ipf_hm_maplist; 443 if (ifs->ifs_ipf_hm_maplist != NULL) 444 ifs->ifs_ipf_hm_maplist->hm_phnext = &hm->hm_hnext; 445 ifs->ifs_ipf_hm_maplist = hm; 446 447 hm->hm_next = ifs->ifs_maptable[hv]; 448 hm->hm_pnext = ifs->ifs_maptable + hv; 449 if (ifs->ifs_maptable[hv] != NULL) 450 ifs->ifs_maptable[hv]->hm_pnext = &hm->hm_next; 451 ifs->ifs_maptable[hv] = hm; 452 hm->hm_ipnat = np; 453 hm->hm_srcip = src; 454 hm->hm_dstip = dst; 455 hm->hm_mapip = map; 456 hm->hm_ref = 1; 457 hm->hm_port = port; 458 hm->hm_v = 4; 459 } 460 return hm; 461 } 462 463 464 /* ------------------------------------------------------------------------ */ 465 /* Function: fr_hostmapdel */ 466 /* Returns: Nil */ 467 /* Parameters: hmp(I) - pointer to pointer to hostmap structure */ 468 /* Write Locks: ipf_nat */ 469 /* */ 470 /* Decrement the references to this hostmap structure by one. If this */ 471 /* reaches zero then remove it and free it. */ 472 /* ------------------------------------------------------------------------ */ 473 void fr_hostmapdel(hmp) 474 struct hostmap **hmp; 475 { 476 struct hostmap *hm; 477 478 hm = *hmp; 479 *hmp = NULL; 480 481 hm->hm_ref--; 482 if (hm->hm_ref == 0) { 483 if (hm->hm_next) 484 hm->hm_next->hm_pnext = hm->hm_pnext; 485 *hm->hm_pnext = hm->hm_next; 486 if (hm->hm_hnext) 487 hm->hm_hnext->hm_phnext = hm->hm_phnext; 488 *hm->hm_phnext = hm->hm_hnext; 489 KFREE(hm); 490 } 491 } 492 493 494 /* ------------------------------------------------------------------------ */ 495 /* Function: fix_outcksum */ 496 /* Returns: Nil */ 497 /* Parameters: sp(I) - location of 16bit checksum to update */ 498 /* n((I) - amount to adjust checksum by */ 499 /* */ 500 /* Adjusts the 16bit checksum by "n" for packets going out. */ 501 /* ------------------------------------------------------------------------ */ 502 void fix_outcksum(sp, n) 503 u_short *sp; 504 u_32_t n; 505 { 506 u_short sumshort; 507 u_32_t sum1; 508 509 if (n == 0) 510 return; 511 512 sum1 = (~ntohs(*sp)) & 0xffff; 513 sum1 += (n); 514 sum1 = (sum1 >> 16) + (sum1 & 0xffff); 515 /* Again */ 516 sum1 = (sum1 >> 16) + (sum1 & 0xffff); 517 sumshort = ~(u_short)sum1; 518 *(sp) = htons(sumshort); 519 } 520 521 522 /* ------------------------------------------------------------------------ */ 523 /* Function: fix_incksum */ 524 /* Returns: Nil */ 525 /* Parameters: sp(I) - location of 16bit checksum to update */ 526 /* n((I) - amount to adjust checksum by */ 527 /* */ 528 /* Adjusts the 16bit checksum by "n" for packets going in. */ 529 /* ------------------------------------------------------------------------ */ 530 void fix_incksum(sp, n) 531 u_short *sp; 532 u_32_t n; 533 { 534 u_short sumshort; 535 u_32_t sum1; 536 537 if (n == 0) 538 return; 539 540 sum1 = (~ntohs(*sp)) & 0xffff; 541 sum1 += ~(n) & 0xffff; 542 sum1 = (sum1 >> 16) + (sum1 & 0xffff); 543 /* Again */ 544 sum1 = (sum1 >> 16) + (sum1 & 0xffff); 545 sumshort = ~(u_short)sum1; 546 *(sp) = htons(sumshort); 547 } 548 549 550 /* ------------------------------------------------------------------------ */ 551 /* Function: fix_datacksum */ 552 /* Returns: Nil */ 553 /* Parameters: sp(I) - location of 16bit checksum to update */ 554 /* n((I) - amount to adjust checksum by */ 555 /* */ 556 /* Fix_datacksum is used *only* for the adjustments of checksums in the */ 557 /* data section of an IP packet. */ 558 /* */ 559 /* The only situation in which you need to do this is when NAT'ing an */ 560 /* ICMP error message. Such a message, contains in its body the IP header */ 561 /* of the original IP packet, that causes the error. */ 562 /* */ 563 /* You can't use fix_incksum or fix_outcksum in that case, because for the */ 564 /* kernel the data section of the ICMP error is just data, and no special */ 565 /* processing like hardware cksum or ntohs processing have been done by the */ 566 /* kernel on the data section. */ 567 /* ------------------------------------------------------------------------ */ 568 void fix_datacksum(sp, n) 569 u_short *sp; 570 u_32_t n; 571 { 572 u_short sumshort; 573 u_32_t sum1; 574 575 if (n == 0) 576 return; 577 578 sum1 = (~ntohs(*sp)) & 0xffff; 579 sum1 += (n); 580 sum1 = (sum1 >> 16) + (sum1 & 0xffff); 581 /* Again */ 582 sum1 = (sum1 >> 16) + (sum1 & 0xffff); 583 sumshort = ~(u_short)sum1; 584 *(sp) = htons(sumshort); 585 } 586 587 588 /* ------------------------------------------------------------------------ */ 589 /* Function: fr_nat_ioctl */ 590 /* Returns: int - 0 == success, != 0 == failure */ 591 /* Parameters: data(I) - pointer to ioctl data */ 592 /* cmd(I) - ioctl command integer */ 593 /* mode(I) - file mode bits used with open */ 594 /* uid(I) - uid of caller */ 595 /* ctx(I) - pointer to give the uid context */ 596 /* ifs - ipf stack instance */ 597 /* */ 598 /* Processes an ioctl call made to operate on the IP Filter NAT device. */ 599 /* ------------------------------------------------------------------------ */ 600 int fr_nat_ioctl(data, cmd, mode, uid, ctx, ifs) 601 ioctlcmd_t cmd; 602 caddr_t data; 603 int mode, uid; 604 void *ctx; 605 ipf_stack_t *ifs; 606 { 607 ipnat_t *nat, *nt, *n = NULL, **np = NULL; 608 int error = 0, ret, arg, getlock; 609 ipnat_t natd; 610 611 #if (BSD >= 199306) && defined(_KERNEL) 612 if ((securelevel >= 2) && (mode & FWRITE)) 613 return EPERM; 614 #endif 615 616 #if defined(__osf__) && defined(_KERNEL) 617 getlock = 0; 618 #else 619 getlock = (mode & NAT_LOCKHELD) ? 0 : 1; 620 #endif 621 622 nat = NULL; /* XXX gcc -Wuninitialized */ 623 if (cmd == (ioctlcmd_t)SIOCADNAT) { 624 KMALLOC(nt, ipnat_t *); 625 } else { 626 nt = NULL; 627 } 628 629 if ((cmd == (ioctlcmd_t)SIOCADNAT) || (cmd == (ioctlcmd_t)SIOCRMNAT)) { 630 if (mode & NAT_SYSSPACE) { 631 bcopy(data, (char *)&natd, sizeof(natd)); 632 error = 0; 633 } else { 634 error = fr_inobj(data, &natd, IPFOBJ_IPNAT); 635 } 636 637 } 638 639 if (error != 0) 640 goto done; 641 642 /* 643 * For add/delete, look to see if the NAT entry is already present 644 */ 645 if ((cmd == (ioctlcmd_t)SIOCADNAT) || (cmd == (ioctlcmd_t)SIOCRMNAT)) { 646 nat = &natd; 647 if (nat->in_v == 0) /* For backward compat. */ 648 nat->in_v = 4; 649 nat->in_flags &= IPN_USERFLAGS; 650 if ((nat->in_redir & NAT_MAPBLK) == 0) { 651 if ((nat->in_flags & IPN_SPLIT) == 0) 652 nat->in_inip &= nat->in_inmsk; 653 if ((nat->in_flags & IPN_IPRANGE) == 0) 654 nat->in_outip &= nat->in_outmsk; 655 } 656 MUTEX_ENTER(&ifs->ifs_ipf_natio); 657 for (np = &ifs->ifs_nat_list; ((n = *np) != NULL); 658 np = &n->in_next) 659 if (bcmp((char *)&nat->in_flags, (char *)&n->in_flags, 660 IPN_CMPSIZ) == 0) { 661 if (nat->in_redir == NAT_REDIRECT && 662 nat->in_pnext != n->in_pnext) 663 continue; 664 break; 665 } 666 } 667 668 switch (cmd) 669 { 670 case SIOCGENITER : 671 { 672 ipfgeniter_t iter; 673 ipftoken_t *token; 674 675 error = fr_inobj(data, &iter, IPFOBJ_GENITER); 676 if (error != 0) 677 break; 678 679 token = ipf_findtoken(iter.igi_type, uid, ctx, ifs); 680 if (token != NULL) 681 error = nat_iterator(token, &iter, ifs); 682 else 683 error = ESRCH; 684 RWLOCK_EXIT(&ifs->ifs_ipf_tokens); 685 break; 686 } 687 #ifdef IPFILTER_LOG 688 case SIOCIPFFB : 689 { 690 int tmp; 691 692 if (!(mode & FWRITE)) 693 error = EPERM; 694 else { 695 tmp = ipflog_clear(IPL_LOGNAT, ifs); 696 error = BCOPYOUT((char *)&tmp, (char *)data, 697 sizeof(tmp)); 698 if (error != 0) 699 error = EFAULT; 700 } 701 break; 702 } 703 case SIOCSETLG : 704 if (!(mode & FWRITE)) { 705 error = EPERM; 706 } else { 707 error = BCOPYIN((char *)data, 708 (char *)&ifs->ifs_nat_logging, 709 sizeof(ifs->ifs_nat_logging)); 710 if (error != 0) 711 error = EFAULT; 712 } 713 break; 714 case SIOCGETLG : 715 error = BCOPYOUT((char *)&ifs->ifs_nat_logging, (char *)data, 716 sizeof(ifs->ifs_nat_logging)); 717 if (error != 0) 718 error = EFAULT; 719 break; 720 case FIONREAD : 721 arg = ifs->ifs_iplused[IPL_LOGNAT]; 722 error = BCOPYOUT(&arg, data, sizeof(arg)); 723 if (error != 0) 724 error = EFAULT; 725 break; 726 #endif 727 case SIOCADNAT : 728 if (!(mode & FWRITE)) { 729 error = EPERM; 730 } else if (n != NULL) { 731 error = EEXIST; 732 } else if (nt == NULL) { 733 error = ENOMEM; 734 } 735 if (error != 0) { 736 MUTEX_EXIT(&ifs->ifs_ipf_natio); 737 break; 738 } 739 bcopy((char *)nat, (char *)nt, sizeof(*n)); 740 error = nat_siocaddnat(nt, np, getlock, ifs); 741 MUTEX_EXIT(&ifs->ifs_ipf_natio); 742 if (error == 0) 743 nt = NULL; 744 break; 745 case SIOCRMNAT : 746 if (!(mode & FWRITE)) { 747 error = EPERM; 748 n = NULL; 749 } else if (n == NULL) { 750 error = ESRCH; 751 } 752 753 if (error != 0) { 754 MUTEX_EXIT(&ifs->ifs_ipf_natio); 755 break; 756 } 757 nat_siocdelnat(n, np, getlock, ifs); 758 759 MUTEX_EXIT(&ifs->ifs_ipf_natio); 760 n = NULL; 761 break; 762 case SIOCGNATS : 763 ifs->ifs_nat_stats.ns_table[0] = ifs->ifs_nat_table[0]; 764 ifs->ifs_nat_stats.ns_table[1] = ifs->ifs_nat_table[1]; 765 ifs->ifs_nat_stats.ns_list = ifs->ifs_nat_list; 766 ifs->ifs_nat_stats.ns_maptable = ifs->ifs_maptable; 767 ifs->ifs_nat_stats.ns_maplist = ifs->ifs_ipf_hm_maplist; 768 ifs->ifs_nat_stats.ns_nattab_max = ifs->ifs_ipf_nattable_max; 769 ifs->ifs_nat_stats.ns_nattab_sz = ifs->ifs_ipf_nattable_sz; 770 ifs->ifs_nat_stats.ns_rultab_sz = ifs->ifs_ipf_natrules_sz; 771 ifs->ifs_nat_stats.ns_rdrtab_sz = ifs->ifs_ipf_rdrrules_sz; 772 ifs->ifs_nat_stats.ns_hostmap_sz = ifs->ifs_ipf_hostmap_sz; 773 ifs->ifs_nat_stats.ns_instances = ifs->ifs_nat_instances; 774 ifs->ifs_nat_stats.ns_apslist = ifs->ifs_ap_sess_list; 775 error = fr_outobj(data, &ifs->ifs_nat_stats, IPFOBJ_NATSTAT); 776 break; 777 case SIOCGNATL : 778 { 779 natlookup_t nl; 780 781 if (getlock) { 782 READ_ENTER(&ifs->ifs_ipf_nat); 783 } 784 error = fr_inobj(data, &nl, IPFOBJ_NATLOOKUP); 785 if (nl.nl_v != 6) 786 nl.nl_v = 4; 787 if (error == 0) { 788 void *ptr; 789 790 switch (nl.nl_v) 791 { 792 case 4: 793 ptr = nat_lookupredir(&nl, ifs); 794 break; 795 #ifdef USE_INET6 796 case 6: 797 ptr = nat6_lookupredir(&nl, ifs); 798 break; 799 #endif 800 default: 801 ptr = NULL; 802 break; 803 } 804 805 if (ptr != NULL) { 806 error = fr_outobj(data, &nl, IPFOBJ_NATLOOKUP); 807 } else { 808 error = ESRCH; 809 } 810 } 811 if (getlock) { 812 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 813 } 814 break; 815 } 816 case SIOCIPFFL : /* old SIOCFLNAT & SIOCCNATL */ 817 if (!(mode & FWRITE)) { 818 error = EPERM; 819 break; 820 } 821 if (getlock) { 822 WRITE_ENTER(&ifs->ifs_ipf_nat); 823 } 824 error = BCOPYIN(data, &arg, sizeof(arg)); 825 if (error != 0) { 826 error = EFAULT; 827 } else { 828 if (arg == FLUSH_LIST) 829 ret = nat_clearlist(ifs); 830 else if (VALID_TABLE_FLUSH_OPT(arg)) 831 ret = nat_flushtable(arg, ifs); 832 else 833 error = EINVAL; 834 } 835 if (getlock) { 836 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 837 } 838 if (error == 0) { 839 error = BCOPYOUT(&ret, data, sizeof(ret)); 840 if (error != 0) 841 error = EFAULT; 842 } 843 break; 844 case SIOCPROXY : 845 error = appr_ioctl(data, cmd, mode, ifs); 846 break; 847 case SIOCSTLCK : 848 if (!(mode & FWRITE)) { 849 error = EPERM; 850 } else { 851 error = fr_lock(data, &ifs->ifs_fr_nat_lock); 852 } 853 break; 854 case SIOCSTPUT : 855 if ((mode & FWRITE) != 0) { 856 error = fr_natputent(data, getlock, ifs); 857 } else { 858 error = EACCES; 859 } 860 break; 861 case SIOCSTGSZ : 862 if (ifs->ifs_fr_nat_lock) { 863 if (getlock) { 864 READ_ENTER(&ifs->ifs_ipf_nat); 865 } 866 error = fr_natgetsz(data, ifs); 867 if (getlock) { 868 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 869 } 870 } else 871 error = EACCES; 872 break; 873 case SIOCSTGET : 874 if (ifs->ifs_fr_nat_lock) { 875 if (getlock) { 876 READ_ENTER(&ifs->ifs_ipf_nat); 877 } 878 error = fr_natgetent(data, ifs); 879 if (getlock) { 880 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 881 } 882 } else 883 error = EACCES; 884 break; 885 case SIOCIPFDELTOK : 886 error = BCOPYIN((caddr_t)data, (caddr_t)&arg, sizeof(arg)); 887 if (error != 0) { 888 error = EFAULT; 889 } else { 890 error = ipf_deltoken(arg, uid, ctx, ifs); 891 } 892 break; 893 default : 894 error = EINVAL; 895 break; 896 } 897 done: 898 if (nt) 899 KFREE(nt); 900 return error; 901 } 902 903 904 /* ------------------------------------------------------------------------ */ 905 /* Function: nat_siocaddnat */ 906 /* Returns: int - 0 == success, != 0 == failure */ 907 /* Parameters: n(I) - pointer to new NAT rule */ 908 /* np(I) - pointer to where to insert new NAT rule */ 909 /* getlock(I) - flag indicating if lock on ipf_nat is held */ 910 /* Mutex Locks: ipf_natio */ 911 /* */ 912 /* Handle SIOCADNAT. Resolve and calculate details inside the NAT rule */ 913 /* from information passed to the kernel, then add it to the appropriate */ 914 /* NAT rule table(s). */ 915 /* ------------------------------------------------------------------------ */ 916 static int nat_siocaddnat(n, np, getlock, ifs) 917 ipnat_t *n, **np; 918 int getlock; 919 ipf_stack_t *ifs; 920 { 921 int error = 0, i, j; 922 923 if (nat_resolverule(n, ifs) != 0) 924 return ENOENT; 925 926 if ((n->in_age[0] == 0) && (n->in_age[1] != 0)) 927 return EINVAL; 928 929 n->in_use = 0; 930 if (n->in_redir & NAT_MAPBLK) 931 n->in_space = USABLE_PORTS * ~ntohl(n->in_outmsk); 932 else if (n->in_flags & IPN_AUTOPORTMAP) 933 n->in_space = USABLE_PORTS * ~ntohl(n->in_inmsk); 934 else if (n->in_flags & IPN_IPRANGE) 935 n->in_space = ntohl(n->in_outmsk) - ntohl(n->in_outip); 936 else if (n->in_flags & IPN_SPLIT) 937 n->in_space = 2; 938 else if (n->in_outmsk != 0) 939 n->in_space = ~ntohl(n->in_outmsk); 940 else 941 n->in_space = 1; 942 if (n->in_flags & NAT_TCPUDPICMPQ) { 943 if (ntohs(n->in_pmax) < ntohs(n->in_pmin)) 944 return EINVAL; 945 } 946 947 /* 948 * Calculate the number of valid IP addresses in the output 949 * mapping range. In all cases, the range is inclusive of 950 * the start and ending IP addresses. 951 * If to a CIDR address, lose 2: broadcast + network address 952 * (so subtract 1) 953 * If to a range, add one. 954 * If to a single IP address, set to 1. 955 */ 956 if (n->in_space) { 957 if ((n->in_flags & IPN_IPRANGE) != 0) 958 n->in_space += 1; 959 else 960 n->in_space -= 1; 961 } else 962 n->in_space = 1; 963 964 #ifdef USE_INET6 965 if (n->in_v == 6 && (n->in_flags & (IPN_IPRANGE|IPN_SPLIT)) == 0 && 966 !IP6_ISONES(&n->in_out[1]) && !IP6_ISZERO(&n->in_out[1])) 967 IP6_ADD(&n->in_out[0], 1, &n->in_next6) 968 else if (n->in_v == 6 && 969 (n->in_flags & IPN_SPLIT) && (n->in_redir & NAT_REDIRECT)) 970 n->in_next6 = n->in_in[0]; 971 else if (n->in_v == 6) 972 n->in_next6 = n->in_out[0]; 973 else 974 #endif 975 if ((n->in_outmsk != 0xffffffff) && (n->in_outmsk != 0) && 976 ((n->in_flags & (IPN_IPRANGE|IPN_SPLIT)) == 0)) 977 n->in_nip = ntohl(n->in_outip) + 1; 978 else if ((n->in_flags & IPN_SPLIT) && 979 (n->in_redir & NAT_REDIRECT)) 980 n->in_nip = ntohl(n->in_inip); 981 else 982 n->in_nip = ntohl(n->in_outip); 983 984 if (n->in_redir & NAT_MAP) { 985 n->in_pnext = ntohs(n->in_pmin); 986 /* 987 * Multiply by the number of ports made available. 988 */ 989 if (ntohs(n->in_pmax) >= ntohs(n->in_pmin)) { 990 n->in_space *= (ntohs(n->in_pmax) - 991 ntohs(n->in_pmin) + 1); 992 /* 993 * Because two different sources can map to 994 * different destinations but use the same 995 * local IP#/port #. 996 * If the result is smaller than in_space, then 997 * we may have wrapped around 32bits. 998 */ 999 i = n->in_inmsk; 1000 if ((i != 0) && (i != 0xffffffff)) { 1001 j = n->in_space * (~ntohl(i) + 1); 1002 if (j >= n->in_space) 1003 n->in_space = j; 1004 else 1005 n->in_space = 0xffffffff; 1006 } 1007 } 1008 /* 1009 * If no protocol is specified, multiple by 256 to allow for 1010 * at least one IP:IP mapping per protocol. 1011 */ 1012 if ((n->in_flags & IPN_TCPUDPICMP) == 0) { 1013 j = n->in_space * 256; 1014 if (j >= n->in_space) 1015 n->in_space = j; 1016 else 1017 n->in_space = 0xffffffff; 1018 } 1019 } 1020 1021 /* Otherwise, these fields are preset */ 1022 1023 if (getlock) { 1024 WRITE_ENTER(&ifs->ifs_ipf_nat); 1025 } 1026 n->in_next = NULL; 1027 *np = n; 1028 1029 if (n->in_age[0] != 0) 1030 n->in_tqehead[0] = fr_addtimeoutqueue(&ifs->ifs_nat_utqe, 1031 n->in_age[0], ifs); 1032 1033 if (n->in_age[1] != 0) 1034 n->in_tqehead[1] = fr_addtimeoutqueue(&ifs->ifs_nat_utqe, 1035 n->in_age[1], ifs); 1036 1037 if (n->in_redir & NAT_REDIRECT) { 1038 n->in_flags &= ~IPN_NOTDST; 1039 switch (n->in_v) 1040 { 1041 case 4 : 1042 nat_addrdr(n, ifs); 1043 break; 1044 #ifdef USE_INET6 1045 case 6 : 1046 nat6_addrdr(n, ifs); 1047 break; 1048 #endif 1049 default : 1050 break; 1051 } 1052 } 1053 if (n->in_redir & (NAT_MAP|NAT_MAPBLK)) { 1054 n->in_flags &= ~IPN_NOTSRC; 1055 switch (n->in_v) 1056 { 1057 case 4 : 1058 nat_addnat(n, ifs); 1059 break; 1060 #ifdef USE_INET6 1061 case 6 : 1062 nat6_addnat(n, ifs); 1063 break; 1064 #endif 1065 default : 1066 break; 1067 } 1068 } 1069 n = NULL; 1070 ifs->ifs_nat_stats.ns_rules++; 1071 if (getlock) { 1072 RWLOCK_EXIT(&ifs->ifs_ipf_nat); /* WRITE */ 1073 } 1074 1075 return error; 1076 } 1077 1078 1079 /* ------------------------------------------------------------------------ */ 1080 /* Function: nat_resolvrule */ 1081 /* Returns: int - 0 == success, -1 == failure */ 1082 /* Parameters: n(I) - pointer to NAT rule */ 1083 /* */ 1084 /* Resolve some of the details inside the NAT rule. Includes resolving */ 1085 /* any specified interfaces and proxy labels, and determines whether or not */ 1086 /* all proxy labels are correctly specified. */ 1087 /* */ 1088 /* Called by nat_siocaddnat() (SIOCADNAT) and fr_natputent (SIOCSTPUT). */ 1089 /* ------------------------------------------------------------------------ */ 1090 static int nat_resolverule(n, ifs) 1091 ipnat_t *n; 1092 ipf_stack_t *ifs; 1093 { 1094 n->in_ifnames[0][LIFNAMSIZ - 1] = '\0'; 1095 n->in_ifps[0] = fr_resolvenic(n->in_ifnames[0], n->in_v, ifs); 1096 1097 n->in_ifnames[1][LIFNAMSIZ - 1] = '\0'; 1098 if (n->in_ifnames[1][0] == '\0') { 1099 (void) strncpy(n->in_ifnames[1], n->in_ifnames[0], LIFNAMSIZ); 1100 n->in_ifps[1] = n->in_ifps[0]; 1101 } else { 1102 n->in_ifps[1] = fr_resolvenic(n->in_ifnames[1], n->in_v, ifs); 1103 } 1104 1105 if (n->in_plabel[0] != '\0') { 1106 n->in_apr = appr_lookup(n->in_p, n->in_plabel, ifs); 1107 if (n->in_apr == NULL) 1108 return -1; 1109 } 1110 return 0; 1111 } 1112 1113 1114 /* ------------------------------------------------------------------------ */ 1115 /* Function: nat_siocdelnat */ 1116 /* Returns: int - 0 == success, != 0 == failure */ 1117 /* Parameters: n(I) - pointer to new NAT rule */ 1118 /* np(I) - pointer to where to insert new NAT rule */ 1119 /* getlock(I) - flag indicating if lock on ipf_nat is held */ 1120 /* Mutex Locks: ipf_natio */ 1121 /* */ 1122 /* Handle SIOCADNAT. Resolve and calculate details inside the NAT rule */ 1123 /* from information passed to the kernel, then add it to the appropriate */ 1124 /* NAT rule table(s). */ 1125 /* ------------------------------------------------------------------------ */ 1126 static void nat_siocdelnat(n, np, getlock, ifs) 1127 ipnat_t *n, **np; 1128 int getlock; 1129 ipf_stack_t *ifs; 1130 { 1131 int i; 1132 1133 if (getlock) { 1134 WRITE_ENTER(&ifs->ifs_ipf_nat); 1135 } 1136 if (n->in_redir & NAT_REDIRECT) 1137 nat_delrdr(n); 1138 if (n->in_redir & (NAT_MAPBLK|NAT_MAP)) 1139 nat_delnat(n); 1140 if (ifs->ifs_nat_list == NULL) { 1141 ifs->ifs_nat_masks = 0; 1142 ifs->ifs_rdr_masks = 0; 1143 for (i = 0; i < 4; i++) { 1144 ifs->ifs_nat6_masks[i] = 0; 1145 ifs->ifs_rdr6_masks[i] = 0; 1146 } 1147 } 1148 1149 if (n->in_tqehead[0] != NULL) { 1150 if (fr_deletetimeoutqueue(n->in_tqehead[0]) == 0) { 1151 fr_freetimeoutqueue(n->in_tqehead[0], ifs); 1152 } 1153 } 1154 1155 if (n->in_tqehead[1] != NULL) { 1156 if (fr_deletetimeoutqueue(n->in_tqehead[1]) == 0) { 1157 fr_freetimeoutqueue(n->in_tqehead[1], ifs); 1158 } 1159 } 1160 1161 *np = n->in_next; 1162 1163 if (n->in_use == 0) { 1164 if (n->in_apr) 1165 appr_free(n->in_apr); 1166 KFREE(n); 1167 ifs->ifs_nat_stats.ns_rules--; 1168 } else { 1169 n->in_flags |= IPN_DELETE; 1170 n->in_next = NULL; 1171 } 1172 if (getlock) { 1173 RWLOCK_EXIT(&ifs->ifs_ipf_nat); /* READ/WRITE */ 1174 } 1175 } 1176 1177 1178 /* ------------------------------------------------------------------------ */ 1179 /* Function: fr_natgetsz */ 1180 /* Returns: int - 0 == success, != 0 is the error value. */ 1181 /* Parameters: data(I) - pointer to natget structure with kernel pointer */ 1182 /* get the size of. */ 1183 /* */ 1184 /* Handle SIOCSTGSZ. */ 1185 /* Return the size of the nat list entry to be copied back to user space. */ 1186 /* The size of the entry is stored in the ng_sz field and the enture natget */ 1187 /* structure is copied back to the user. */ 1188 /* ------------------------------------------------------------------------ */ 1189 static int fr_natgetsz(data, ifs) 1190 caddr_t data; 1191 ipf_stack_t *ifs; 1192 { 1193 ap_session_t *aps; 1194 nat_t *nat, *n; 1195 natget_t ng; 1196 int err; 1197 1198 err = BCOPYIN(data, &ng, sizeof(ng)); 1199 if (err != 0) 1200 return EFAULT; 1201 1202 nat = ng.ng_ptr; 1203 if (!nat) { 1204 nat = ifs->ifs_nat_instances; 1205 ng.ng_sz = 0; 1206 /* 1207 * Empty list so the size returned is 0. Simple. 1208 */ 1209 if (nat == NULL) { 1210 err = BCOPYOUT(&ng, data, sizeof(ng)); 1211 if (err != 0) { 1212 return EFAULT; 1213 } else { 1214 return 0; 1215 } 1216 } 1217 } else { 1218 /* 1219 * Make sure the pointer we're copying from exists in the 1220 * current list of entries. Security precaution to prevent 1221 * copying of random kernel data. 1222 */ 1223 for (n = ifs->ifs_nat_instances; n; n = n->nat_next) 1224 if (n == nat) 1225 break; 1226 if (!n) 1227 return ESRCH; 1228 } 1229 1230 /* 1231 * Incluse any space required for proxy data structures. 1232 */ 1233 ng.ng_sz = sizeof(nat_save_t); 1234 aps = nat->nat_aps; 1235 if (aps != NULL) { 1236 ng.ng_sz += sizeof(ap_session_t) - 4; 1237 if (aps->aps_data != 0) 1238 ng.ng_sz += aps->aps_psiz; 1239 } 1240 1241 err = BCOPYOUT(&ng, data, sizeof(ng)); 1242 if (err != 0) 1243 return EFAULT; 1244 return 0; 1245 } 1246 1247 1248 /* ------------------------------------------------------------------------ */ 1249 /* Function: fr_natgetent */ 1250 /* Returns: int - 0 == success, != 0 is the error value. */ 1251 /* Parameters: data(I) - pointer to natget structure with kernel pointer */ 1252 /* to NAT structure to copy out. */ 1253 /* */ 1254 /* Handle SIOCSTGET. */ 1255 /* Copies out NAT entry to user space. Any additional data held for a */ 1256 /* proxy is also copied, as to is the NAT rule which was responsible for it */ 1257 /* ------------------------------------------------------------------------ */ 1258 static int fr_natgetent(data, ifs) 1259 caddr_t data; 1260 ipf_stack_t *ifs; 1261 { 1262 int error, outsize; 1263 ap_session_t *aps; 1264 nat_save_t *ipn, ipns; 1265 nat_t *n, *nat; 1266 1267 error = fr_inobj(data, &ipns, IPFOBJ_NATSAVE); 1268 if (error != 0) 1269 return error; 1270 1271 if ((ipns.ipn_dsize < sizeof(ipns)) || (ipns.ipn_dsize > 81920)) 1272 return EINVAL; 1273 1274 KMALLOCS(ipn, nat_save_t *, ipns.ipn_dsize); 1275 if (ipn == NULL) 1276 return ENOMEM; 1277 1278 ipn->ipn_dsize = ipns.ipn_dsize; 1279 nat = ipns.ipn_next; 1280 if (nat == NULL) { 1281 nat = ifs->ifs_nat_instances; 1282 if (nat == NULL) { 1283 if (ifs->ifs_nat_instances == NULL) 1284 error = ENOENT; 1285 goto finished; 1286 } 1287 } else { 1288 /* 1289 * Make sure the pointer we're copying from exists in the 1290 * current list of entries. Security precaution to prevent 1291 * copying of random kernel data. 1292 */ 1293 for (n = ifs->ifs_nat_instances; n; n = n->nat_next) 1294 if (n == nat) 1295 break; 1296 if (n == NULL) { 1297 error = ESRCH; 1298 goto finished; 1299 } 1300 } 1301 ipn->ipn_next = nat->nat_next; 1302 1303 /* 1304 * Copy the NAT structure. 1305 */ 1306 bcopy((char *)nat, &ipn->ipn_nat, sizeof(*nat)); 1307 1308 /* 1309 * If we have a pointer to the NAT rule it belongs to, save that too. 1310 */ 1311 if (nat->nat_ptr != NULL) 1312 bcopy((char *)nat->nat_ptr, (char *)&ipn->ipn_ipnat, 1313 sizeof(ipn->ipn_ipnat)); 1314 1315 /* 1316 * If we also know the NAT entry has an associated filter rule, 1317 * save that too. 1318 */ 1319 if (nat->nat_fr != NULL) 1320 bcopy((char *)nat->nat_fr, (char *)&ipn->ipn_fr, 1321 sizeof(ipn->ipn_fr)); 1322 1323 /* 1324 * Last but not least, if there is an application proxy session set 1325 * up for this NAT entry, then copy that out too, including any 1326 * private data saved along side it by the proxy. 1327 */ 1328 aps = nat->nat_aps; 1329 outsize = ipn->ipn_dsize - sizeof(*ipn) + sizeof(ipn->ipn_data); 1330 if (aps != NULL) { 1331 char *s; 1332 1333 if (outsize < sizeof(*aps)) { 1334 error = ENOBUFS; 1335 goto finished; 1336 } 1337 1338 s = ipn->ipn_data; 1339 bcopy((char *)aps, s, sizeof(*aps)); 1340 s += sizeof(*aps); 1341 outsize -= sizeof(*aps); 1342 if ((aps->aps_data != NULL) && (outsize >= aps->aps_psiz)) 1343 bcopy(aps->aps_data, s, aps->aps_psiz); 1344 else 1345 error = ENOBUFS; 1346 } 1347 if (error == 0) { 1348 error = fr_outobjsz(data, ipn, IPFOBJ_NATSAVE, ipns.ipn_dsize); 1349 } 1350 1351 finished: 1352 if (ipn != NULL) { 1353 KFREES(ipn, ipns.ipn_dsize); 1354 } 1355 return error; 1356 } 1357 1358 /* ------------------------------------------------------------------------ */ 1359 /* Function: nat_calc_chksum_diffs */ 1360 /* Returns: void */ 1361 /* Parameters: nat - pointer to NAT table entry */ 1362 /* */ 1363 /* Function calculates chksum deltas for IP header (nat_ipsumd) and TCP/UDP */ 1364 /* headers (nat_sumd). The things for L4 (UDP/TCP) get complicated when */ 1365 /* we are dealing with partial chksum offload. For these cases we need to */ 1366 /* compute a 'partial chksum delta'. The 'partial chksum delta'is stored */ 1367 /* into nat_sumd[1], while ordinary chksum delta for TCP/UDP is in */ 1368 /* nat_sumd[0]. */ 1369 /* */ 1370 /* The function accepts initialized NAT table entry and computes the deltas */ 1371 /* from nat_inip/nat_outip members. The function is called right before */ 1372 /* the new entry is inserted into the table. */ 1373 /* */ 1374 /* The ipsumd (IP hedaer chksum delta adjustment) is computed as a chksum */ 1375 /* of delta between original and new IP addresses. */ 1376 /* */ 1377 /* the nat_sumd[0] (TCP/UDP header chksum delta adjustment) is computed as */ 1378 /* a chkusm of delta between original an new IP addrress:port tupples. */ 1379 /* */ 1380 /* Some facts about chksum, we should remember: */ 1381 /* IP header chksum covers IP header only */ 1382 /* */ 1383 /* TCP/UDP chksum covers data payload and so called pseudo header */ 1384 /* SRC, DST IP address */ 1385 /* SRC, DST Port */ 1386 /* length of payload */ 1387 /* */ 1388 /* The partial chksum delta (nat_sumd[1] is used to adjust db_ckusm16 */ 1389 /* member of dblk_t structure. The db_ckusm16 member is not part of */ 1390 /* IP/UDP/TCP header it is 16 bit value computed by NIC driver with partial */ 1391 /* chksum offload capacbility for every inbound packet. The db_cksum16 is */ 1392 /* stored along with other IP packet data in dblk_t structure and used in */ 1393 /* for IP/UDP/TCP chksum validation later in ip.c. */ 1394 /* */ 1395 /* The partial chksum delta (adjustment, nat_sumd[1]) is computed as chksum */ 1396 /* of delta between new and orig address. NOTE: the order of operands for */ 1397 /* partial delta operation is swapped compared to computing the IP/TCP/UDP */ 1398 /* header adjustment. It is by design see (IP_CKSUM_RECV() macro in ip.c). */ 1399 /* */ 1400 /* ------------------------------------------------------------------------ */ 1401 void nat_calc_chksum_diffs(nat) 1402 nat_t *nat; 1403 { 1404 u_32_t sum_orig = 0; 1405 u_32_t sum_changed = 0; 1406 u_32_t sumd; 1407 u_32_t ipsum_orig = 0; 1408 u_32_t ipsum_changed = 0; 1409 1410 if (nat->nat_v != 4 && nat->nat_v != 6) 1411 return; 1412 1413 /* 1414 * the switch calculates operands for CALC_SUMD(), 1415 * which will compute the partial chksum delta. 1416 */ 1417 switch (nat->nat_dir) 1418 { 1419 case NAT_INBOUND: 1420 /* 1421 * we are dealing with RDR rule (DST address gets 1422 * modified on packet from client) 1423 */ 1424 if (nat->nat_v == 4) { 1425 sum_changed = LONG_SUM(ntohl(nat->nat_inip.s_addr)); 1426 sum_orig = LONG_SUM(ntohl(nat->nat_outip.s_addr)); 1427 } else { 1428 sum_changed = LONG_SUM6(&nat->nat_inip6); 1429 sum_orig = LONG_SUM6(&nat->nat_outip6); 1430 } 1431 break; 1432 case NAT_OUTBOUND: 1433 /* 1434 * we are dealing with MAP rule (SRC address gets 1435 * modified on packet from client) 1436 */ 1437 if (nat->nat_v == 4) { 1438 sum_changed = LONG_SUM(ntohl(nat->nat_outip.s_addr)); 1439 sum_orig = LONG_SUM(ntohl(nat->nat_inip.s_addr)); 1440 } else { 1441 sum_changed = LONG_SUM6(&nat->nat_outip6); 1442 sum_orig = LONG_SUM6(&nat->nat_inip6); 1443 } 1444 break; 1445 default: ; 1446 break; 1447 } 1448 1449 /* 1450 * we also preserve CALC_SUMD() operands here, for IP chksum delta 1451 * calculation, which happens at the end of function. 1452 */ 1453 ipsum_changed = sum_changed; 1454 ipsum_orig = sum_orig; 1455 /* 1456 * NOTE: the order of operands for partial chksum adjustment 1457 * computation has to be swapped! 1458 */ 1459 CALC_SUMD(sum_changed, sum_orig, sumd); 1460 nat->nat_sumd[1] = (sumd & 0xffff) + (sumd >> 16); 1461 1462 if (nat->nat_flags & (IPN_TCPUDP | IPN_ICMPQUERY)) { 1463 1464 /* 1465 * switch calculates operands for CALC_SUMD(), which will 1466 * compute the full chksum delta. 1467 */ 1468 switch (nat->nat_dir) 1469 { 1470 case NAT_INBOUND: 1471 if (nat->nat_v == 4) { 1472 sum_changed = LONG_SUM( 1473 ntohl(nat->nat_inip.s_addr) + 1474 ntohs(nat->nat_inport)); 1475 sum_orig = LONG_SUM( 1476 ntohl(nat->nat_outip.s_addr) + 1477 ntohs(nat->nat_outport)); 1478 } else { 1479 sum_changed = LONG_SUM6(&nat->nat_inip6) + 1480 ntohs(nat->nat_inport); 1481 sum_orig = LONG_SUM6(&nat->nat_outip6) + 1482 ntohs(nat->nat_outport); 1483 } 1484 break; 1485 case NAT_OUTBOUND: 1486 if (nat->nat_v == 4) { 1487 sum_changed = LONG_SUM( 1488 ntohl(nat->nat_outip.s_addr) + 1489 ntohs(nat->nat_outport)); 1490 sum_orig = LONG_SUM( 1491 ntohl(nat->nat_inip.s_addr) + 1492 ntohs(nat->nat_inport)); 1493 } else { 1494 sum_changed = LONG_SUM6(&nat->nat_outip6) + 1495 ntohs(nat->nat_outport); 1496 sum_orig = LONG_SUM6(&nat->nat_inip6) + 1497 ntohs(nat->nat_inport); 1498 } 1499 break; 1500 default: ; 1501 break; 1502 } 1503 1504 CALC_SUMD(sum_orig, sum_changed, sumd); 1505 nat->nat_sumd[0] = (sumd & 0xffff) + (sumd >> 16); 1506 1507 if (!(nat->nat_flags & IPN_TCPUDP)) { 1508 /* 1509 * partial HW chksum offload works for TCP/UDP headers only, 1510 * so we need to enforce full chksum adjustment for ICMP 1511 */ 1512 nat->nat_sumd[1] = nat->nat_sumd[0]; 1513 } 1514 } 1515 else 1516 nat->nat_sumd[0] = nat->nat_sumd[1]; 1517 1518 /* 1519 * we may reuse the already computed nat_sumd[0] for IP header chksum 1520 * adjustment in case the L4 (TCP/UDP header) is not changed by NAT. 1521 */ 1522 if (nat->nat_v == 4) { 1523 if (NAT_HAS_L4_CHANGED(nat)) { 1524 /* 1525 * bad luck, NAT changes also the L4 header, use IP 1526 * addresses to compute chksum adjustment for IP header. 1527 */ 1528 CALC_SUMD(ipsum_orig, ipsum_changed, sumd); 1529 nat->nat_ipsumd = (sumd & 0xffff) + (sumd >> 16); 1530 } else { 1531 /* 1532 * the NAT does not change L4 hdr -> reuse chksum 1533 * adjustment for IP hdr. 1534 */ 1535 nat->nat_ipsumd = nat->nat_sumd[0]; 1536 1537 /* 1538 * if L4 header does not use chksum - zero out deltas 1539 */ 1540 if (!(nat->nat_flags & IPN_TCPUDP)) { 1541 nat->nat_sumd[0] = 0; 1542 nat->nat_sumd[1] = 0; 1543 } 1544 } 1545 } 1546 1547 return; 1548 } 1549 1550 /* ------------------------------------------------------------------------ */ 1551 /* Function: fr_natputent */ 1552 /* Returns: int - 0 == success, != 0 is the error value. */ 1553 /* Parameters: data(I) - pointer to natget structure with NAT */ 1554 /* structure information to load into the kernel */ 1555 /* getlock(I) - flag indicating whether or not a write lock */ 1556 /* on ipf_nat is already held. */ 1557 /* ifs - ipf stack instance */ 1558 /* */ 1559 /* Handle SIOCSTPUT. */ 1560 /* Loads a NAT table entry from user space, including a NAT rule, proxy and */ 1561 /* firewall rule data structures, if pointers to them indicate so. */ 1562 /* ------------------------------------------------------------------------ */ 1563 static int fr_natputent(data, getlock, ifs) 1564 caddr_t data; 1565 int getlock; 1566 ipf_stack_t *ifs; 1567 { 1568 nat_save_t ipn, *ipnn; 1569 ap_session_t *aps; 1570 nat_t *n, *nat; 1571 frentry_t *fr; 1572 fr_info_t fin; 1573 ipnat_t *in; 1574 int error; 1575 1576 error = fr_inobj(data, &ipn, IPFOBJ_NATSAVE); 1577 if (error != 0) 1578 return error; 1579 1580 /* 1581 * Trigger automatic call to nat_flushtable() if the 1582 * table has reached capcity specified by hi watermark. 1583 */ 1584 if (NAT_TAB_WATER_LEVEL(ifs) > ifs->ifs_nat_flush_level_hi) 1585 ifs->ifs_nat_doflush = 1; 1586 1587 /* 1588 * If automatic flushing did not do its job, and the table 1589 * has filled up, don't try to create a new entry. 1590 */ 1591 if (ifs->ifs_nat_stats.ns_inuse >= ifs->ifs_ipf_nattable_max) { 1592 ifs->ifs_nat_stats.ns_memfail++; 1593 return ENOMEM; 1594 } 1595 1596 /* 1597 * Initialise early because of code at junkput label. 1598 */ 1599 in = NULL; 1600 aps = NULL; 1601 nat = NULL; 1602 ipnn = NULL; 1603 1604 /* 1605 * New entry, copy in the rest of the NAT entry if it's size is more 1606 * than just the nat_t structure. 1607 */ 1608 fr = NULL; 1609 if (ipn.ipn_dsize > sizeof(ipn)) { 1610 if (ipn.ipn_dsize > 81920) { 1611 error = ENOMEM; 1612 goto junkput; 1613 } 1614 1615 KMALLOCS(ipnn, nat_save_t *, ipn.ipn_dsize); 1616 if (ipnn == NULL) 1617 return ENOMEM; 1618 1619 error = fr_inobjsz(data, ipnn, IPFOBJ_NATSAVE, ipn.ipn_dsize); 1620 if (error != 0) { 1621 error = EFAULT; 1622 goto junkput; 1623 } 1624 } else 1625 ipnn = &ipn; 1626 1627 KMALLOC(nat, nat_t *); 1628 if (nat == NULL) { 1629 error = ENOMEM; 1630 goto junkput; 1631 } 1632 1633 bcopy((char *)&ipnn->ipn_nat, (char *)nat, sizeof(*nat)); 1634 /* 1635 * Initialize all these so that nat_delete() doesn't cause a crash. 1636 */ 1637 bzero((char *)nat, offsetof(struct nat, nat_tqe)); 1638 nat->nat_tqe.tqe_pnext = NULL; 1639 nat->nat_tqe.tqe_next = NULL; 1640 nat->nat_tqe.tqe_ifq = NULL; 1641 nat->nat_tqe.tqe_parent = nat; 1642 1643 /* 1644 * Restore the rule associated with this nat session 1645 */ 1646 in = ipnn->ipn_nat.nat_ptr; 1647 if (in != NULL) { 1648 KMALLOC(in, ipnat_t *); 1649 nat->nat_ptr = in; 1650 if (in == NULL) { 1651 error = ENOMEM; 1652 goto junkput; 1653 } 1654 bzero((char *)in, offsetof(struct ipnat, in_next6)); 1655 bcopy((char *)&ipnn->ipn_ipnat, (char *)in, sizeof(*in)); 1656 in->in_use = 1; 1657 in->in_flags |= IPN_DELETE; 1658 1659 ATOMIC_INC(ifs->ifs_nat_stats.ns_rules); 1660 1661 if (nat_resolverule(in, ifs) != 0) { 1662 error = ESRCH; 1663 goto junkput; 1664 } 1665 } 1666 1667 /* 1668 * Check that the NAT entry doesn't already exist in the kernel. 1669 */ 1670 if (nat->nat_v != 6) 1671 nat->nat_v = 4; 1672 bzero((char *)&fin, sizeof(fin)); 1673 fin.fin_p = nat->nat_p; 1674 fin.fin_ifs = ifs; 1675 if (nat->nat_dir == NAT_OUTBOUND) { 1676 fin.fin_data[0] = ntohs(nat->nat_oport); 1677 fin.fin_data[1] = ntohs(nat->nat_outport); 1678 fin.fin_ifp = nat->nat_ifps[0]; 1679 if (getlock) { 1680 READ_ENTER(&ifs->ifs_ipf_nat); 1681 } 1682 1683 switch (nat->nat_v) 1684 { 1685 case 4: 1686 fin.fin_v = nat->nat_v; 1687 n = nat_inlookup(&fin, nat->nat_flags, fin.fin_p, 1688 nat->nat_oip, nat->nat_outip); 1689 break; 1690 #ifdef USE_INET6 1691 case 6: 1692 n = nat6_inlookup(&fin, nat->nat_flags, fin.fin_p, 1693 &nat->nat_oip6.in6, &nat->nat_outip6.in6); 1694 break; 1695 #endif 1696 default: 1697 n = NULL; 1698 break; 1699 } 1700 1701 if (getlock) { 1702 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 1703 } 1704 if (n != NULL) { 1705 error = EEXIST; 1706 goto junkput; 1707 } 1708 } else if (nat->nat_dir == NAT_INBOUND) { 1709 fin.fin_data[0] = ntohs(nat->nat_inport); 1710 fin.fin_data[1] = ntohs(nat->nat_oport); 1711 fin.fin_ifp = nat->nat_ifps[1]; 1712 if (getlock) { 1713 READ_ENTER(&ifs->ifs_ipf_nat); 1714 } 1715 1716 switch (nat->nat_v) 1717 { 1718 case 4: 1719 n = nat_outlookup(&fin, nat->nat_flags, fin.fin_p, 1720 nat->nat_inip, nat->nat_oip); 1721 break; 1722 #ifdef USE_INET6 1723 case 6: 1724 n = nat6_outlookup(&fin, nat->nat_flags, fin.fin_p, 1725 &nat->nat_inip6.in6, &nat->nat_oip6.in6); 1726 break; 1727 #endif 1728 default: 1729 n = NULL; 1730 break; 1731 } 1732 1733 if (getlock) { 1734 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 1735 } 1736 if (n != NULL) { 1737 error = EEXIST; 1738 goto junkput; 1739 } 1740 } else { 1741 error = EINVAL; 1742 goto junkput; 1743 } 1744 1745 /* 1746 * Restore ap_session_t structure. Include the private data allocated 1747 * if it was there. 1748 */ 1749 aps = nat->nat_aps; 1750 if (aps != NULL) { 1751 KMALLOC(aps, ap_session_t *); 1752 nat->nat_aps = aps; 1753 if (aps == NULL) { 1754 error = ENOMEM; 1755 goto junkput; 1756 } 1757 bcopy(ipnn->ipn_data, (char *)aps, sizeof(*aps)); 1758 if (in != NULL) 1759 aps->aps_apr = in->in_apr; 1760 else 1761 aps->aps_apr = NULL; 1762 if (aps->aps_psiz != 0) { 1763 if (aps->aps_psiz > 81920) { 1764 error = ENOMEM; 1765 goto junkput; 1766 } 1767 KMALLOCS(aps->aps_data, void *, aps->aps_psiz); 1768 if (aps->aps_data == NULL) { 1769 error = ENOMEM; 1770 goto junkput; 1771 } 1772 bcopy(ipnn->ipn_data + sizeof(*aps), aps->aps_data, 1773 aps->aps_psiz); 1774 } else { 1775 aps->aps_psiz = 0; 1776 aps->aps_data = NULL; 1777 } 1778 } 1779 1780 /* 1781 * If there was a filtering rule associated with this entry then 1782 * build up a new one. 1783 */ 1784 fr = nat->nat_fr; 1785 if (fr != NULL) { 1786 if ((nat->nat_flags & SI_NEWFR) != 0) { 1787 KMALLOC(fr, frentry_t *); 1788 nat->nat_fr = fr; 1789 if (fr == NULL) { 1790 error = ENOMEM; 1791 goto junkput; 1792 } 1793 ipnn->ipn_nat.nat_fr = fr; 1794 (void) fr_outobj(data, ipnn, IPFOBJ_NATSAVE); 1795 bcopy((char *)&ipnn->ipn_fr, (char *)fr, sizeof(*fr)); 1796 1797 fr->fr_ref = 1; 1798 fr->fr_dsize = 0; 1799 fr->fr_data = NULL; 1800 fr->fr_type = FR_T_NONE; 1801 1802 MUTEX_NUKE(&fr->fr_lock); 1803 MUTEX_INIT(&fr->fr_lock, "nat-filter rule lock"); 1804 } else { 1805 if (getlock) { 1806 READ_ENTER(&ifs->ifs_ipf_nat); 1807 } 1808 for (n = ifs->ifs_nat_instances; n; n = n->nat_next) 1809 if (n->nat_fr == fr) 1810 break; 1811 1812 if (n != NULL) { 1813 MUTEX_ENTER(&fr->fr_lock); 1814 fr->fr_ref++; 1815 MUTEX_EXIT(&fr->fr_lock); 1816 } 1817 if (getlock) { 1818 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 1819 } 1820 if (!n) { 1821 error = ESRCH; 1822 goto junkput; 1823 } 1824 } 1825 } 1826 1827 if (ipnn != &ipn) { 1828 KFREES(ipnn, ipn.ipn_dsize); 1829 ipnn = NULL; 1830 } 1831 1832 nat_calc_chksum_diffs(nat); 1833 1834 if (getlock) { 1835 WRITE_ENTER(&ifs->ifs_ipf_nat); 1836 } 1837 1838 nat_calc_chksum_diffs(nat); 1839 1840 switch (nat->nat_v) 1841 { 1842 case 4 : 1843 error = nat_insert(nat, nat->nat_rev, ifs); 1844 break; 1845 #ifdef USE_INET6 1846 case 6 : 1847 error = nat6_insert(nat, nat->nat_rev, ifs); 1848 break; 1849 #endif 1850 default : 1851 break; 1852 } 1853 1854 if ((error == 0) && (aps != NULL)) { 1855 aps->aps_next = ifs->ifs_ap_sess_list; 1856 ifs->ifs_ap_sess_list = aps; 1857 } 1858 if (getlock) { 1859 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 1860 } 1861 1862 if (error == 0) 1863 return 0; 1864 1865 error = ENOMEM; 1866 1867 junkput: 1868 if (fr != NULL) 1869 (void) fr_derefrule(&fr, ifs); 1870 1871 if ((ipnn != NULL) && (ipnn != &ipn)) { 1872 KFREES(ipnn, ipn.ipn_dsize); 1873 } 1874 if (nat != NULL) { 1875 if (aps != NULL) { 1876 if (aps->aps_data != NULL) { 1877 KFREES(aps->aps_data, aps->aps_psiz); 1878 } 1879 KFREE(aps); 1880 } 1881 if (in != NULL) { 1882 if (in->in_apr) 1883 appr_free(in->in_apr); 1884 KFREE(in); 1885 } 1886 KFREE(nat); 1887 } 1888 return error; 1889 } 1890 1891 1892 /* ------------------------------------------------------------------------ */ 1893 /* Function: nat_delete */ 1894 /* Returns: int - 0 if entry deleted. Otherwise, ref count on entry */ 1895 /* Parameters: nat - pointer to the NAT entry to delete */ 1896 /* logtype - type of LOG record to create before deleting */ 1897 /* ifs - ipf stack instance */ 1898 /* Write Lock: ipf_nat */ 1899 /* */ 1900 /* Delete a nat entry from the various lists and table. If NAT logging is */ 1901 /* enabled then generate a NAT log record for this event. */ 1902 /* ------------------------------------------------------------------------ */ 1903 int nat_delete(nat, logtype, ifs) 1904 struct nat *nat; 1905 int logtype; 1906 ipf_stack_t *ifs; 1907 { 1908 struct ipnat *ipn; 1909 int removed = 0; 1910 1911 if (logtype != 0 && ifs->ifs_nat_logging != 0) 1912 nat_log(nat, logtype, ifs); 1913 1914 /* 1915 * Start by removing the entry from the hash table of nat entries 1916 * so it will not be "used" again. 1917 * 1918 * It will remain in the "list" of nat entries until all references 1919 * have been accounted for. 1920 */ 1921 if ((nat->nat_phnext[0] != NULL) && (nat->nat_phnext[1] != NULL)) { 1922 removed = 1; 1923 1924 ifs->ifs_nat_stats.ns_bucketlen[0][nat->nat_hv[0]]--; 1925 ifs->ifs_nat_stats.ns_bucketlen[1][nat->nat_hv[1]]--; 1926 1927 *nat->nat_phnext[0] = nat->nat_hnext[0]; 1928 if (nat->nat_hnext[0] != NULL) { 1929 nat->nat_hnext[0]->nat_phnext[0] = nat->nat_phnext[0]; 1930 nat->nat_hnext[0] = NULL; 1931 } 1932 nat->nat_phnext[0] = NULL; 1933 1934 *nat->nat_phnext[1] = nat->nat_hnext[1]; 1935 if (nat->nat_hnext[1] != NULL) { 1936 nat->nat_hnext[1]->nat_phnext[1] = nat->nat_phnext[1]; 1937 nat->nat_hnext[1] = NULL; 1938 } 1939 nat->nat_phnext[1] = NULL; 1940 1941 if ((nat->nat_flags & SI_WILDP) != 0) 1942 ifs->ifs_nat_stats.ns_wilds--; 1943 } 1944 1945 /* 1946 * Next, remove it from the timeout queue it is in. 1947 */ 1948 fr_deletequeueentry(&nat->nat_tqe); 1949 1950 if (nat->nat_me != NULL) { 1951 *nat->nat_me = NULL; 1952 nat->nat_me = NULL; 1953 } 1954 1955 MUTEX_ENTER(&nat->nat_lock); 1956 if (nat->nat_ref > 1) { 1957 nat->nat_ref--; 1958 MUTEX_EXIT(&nat->nat_lock); 1959 if (removed) 1960 ifs->ifs_nat_stats.ns_orphans++; 1961 return (nat->nat_ref); 1962 } 1963 MUTEX_EXIT(&nat->nat_lock); 1964 1965 nat->nat_ref = 0; 1966 1967 /* 1968 * If entry had already been removed, 1969 * it means we're cleaning up an orphan. 1970 */ 1971 if (!removed) 1972 ifs->ifs_nat_stats.ns_orphans--; 1973 1974 #ifdef IPFILTER_SYNC 1975 if (nat->nat_sync) 1976 ipfsync_del(nat->nat_sync); 1977 #endif 1978 1979 /* 1980 * Now remove it from master list of nat table entries 1981 */ 1982 if (nat->nat_pnext != NULL) { 1983 *nat->nat_pnext = nat->nat_next; 1984 if (nat->nat_next != NULL) { 1985 nat->nat_next->nat_pnext = nat->nat_pnext; 1986 nat->nat_next = NULL; 1987 } 1988 nat->nat_pnext = NULL; 1989 } 1990 1991 if (nat->nat_fr != NULL) 1992 (void)fr_derefrule(&nat->nat_fr, ifs); 1993 1994 if (nat->nat_hm != NULL) 1995 fr_hostmapdel(&nat->nat_hm); 1996 1997 /* 1998 * If there is an active reference from the nat entry to its parent 1999 * rule, decrement the rule's reference count and free it too if no 2000 * longer being used. 2001 */ 2002 ipn = nat->nat_ptr; 2003 if (ipn != NULL) { 2004 ipn->in_space++; 2005 ipn->in_use--; 2006 if (ipn->in_use == 0 && (ipn->in_flags & IPN_DELETE)) { 2007 if (ipn->in_apr) 2008 appr_free(ipn->in_apr); 2009 KFREE(ipn); 2010 ifs->ifs_nat_stats.ns_rules--; 2011 } 2012 } 2013 2014 MUTEX_DESTROY(&nat->nat_lock); 2015 2016 aps_free(nat->nat_aps, ifs); 2017 ifs->ifs_nat_stats.ns_inuse--; 2018 2019 /* 2020 * If there's a fragment table entry too for this nat entry, then 2021 * dereference that as well. This is after nat_lock is released 2022 * because of Tru64. 2023 */ 2024 fr_forgetnat((void *)nat, ifs); 2025 2026 KFREE(nat); 2027 2028 return (0); 2029 } 2030 2031 2032 /* ------------------------------------------------------------------------ */ 2033 /* Function: nat_clearlist */ 2034 /* Returns: int - number of NAT/RDR rules deleted */ 2035 /* Parameters: Nil */ 2036 /* */ 2037 /* Delete all rules in the current list of rules. There is nothing elegant */ 2038 /* about this cleanup: simply free all entries on the list of rules and */ 2039 /* clear out the tables used for hashed NAT rule lookups. */ 2040 /* ------------------------------------------------------------------------ */ 2041 static int nat_clearlist(ifs) 2042 ipf_stack_t *ifs; 2043 { 2044 ipnat_t *n, **np = &ifs->ifs_nat_list; 2045 int i = 0; 2046 2047 if (ifs->ifs_nat_rules != NULL) 2048 bzero((char *)ifs->ifs_nat_rules, 2049 sizeof(*ifs->ifs_nat_rules) * ifs->ifs_ipf_natrules_sz); 2050 if (ifs->ifs_rdr_rules != NULL) 2051 bzero((char *)ifs->ifs_rdr_rules, 2052 sizeof(*ifs->ifs_rdr_rules) * ifs->ifs_ipf_rdrrules_sz); 2053 2054 while ((n = *np) != NULL) { 2055 *np = n->in_next; 2056 if (n->in_use == 0) { 2057 if (n->in_apr != NULL) 2058 appr_free(n->in_apr); 2059 KFREE(n); 2060 ifs->ifs_nat_stats.ns_rules--; 2061 } else { 2062 n->in_flags |= IPN_DELETE; 2063 n->in_next = NULL; 2064 } 2065 i++; 2066 } 2067 ifs->ifs_nat_masks = 0; 2068 ifs->ifs_rdr_masks = 0; 2069 for (i = 0; i < 4; i++) { 2070 ifs->ifs_nat6_masks[i] = 0; 2071 ifs->ifs_rdr6_masks[i] = 0; 2072 } 2073 return i; 2074 } 2075 2076 2077 /* ------------------------------------------------------------------------ */ 2078 /* Function: nat_newmap */ 2079 /* Returns: int - -1 == error, 0 == success */ 2080 /* Parameters: fin(I) - pointer to packet information */ 2081 /* nat(I) - pointer to NAT entry */ 2082 /* ni(I) - pointer to structure with misc. information needed */ 2083 /* to create new NAT entry. */ 2084 /* */ 2085 /* Given an empty NAT structure, populate it with new information about a */ 2086 /* new NAT session, as defined by the matching NAT rule. */ 2087 /* ni.nai_ip is passed in uninitialised and must be set, in host byte order,*/ 2088 /* to the new IP address for the translation. */ 2089 /* ------------------------------------------------------------------------ */ 2090 static INLINE int nat_newmap(fin, nat, ni) 2091 fr_info_t *fin; 2092 nat_t *nat; 2093 natinfo_t *ni; 2094 { 2095 u_short st_port, dport, sport, port, sp, dp; 2096 struct in_addr in, inb; 2097 hostmap_t *hm; 2098 u_32_t flags; 2099 u_32_t st_ip; 2100 ipnat_t *np; 2101 nat_t *natl; 2102 int l; 2103 ipf_stack_t *ifs = fin->fin_ifs; 2104 2105 /* 2106 * If it's an outbound packet which doesn't match any existing 2107 * record, then create a new port 2108 */ 2109 l = 0; 2110 hm = NULL; 2111 np = ni->nai_np; 2112 st_ip = np->in_nip; 2113 st_port = np->in_pnext; 2114 flags = ni->nai_flags; 2115 sport = ni->nai_sport; 2116 dport = ni->nai_dport; 2117 2118 /* 2119 * Do a loop until we either run out of entries to try or we find 2120 * a NAT mapping that isn't currently being used. This is done 2121 * because the change to the source is not (usually) being fixed. 2122 */ 2123 do { 2124 port = 0; 2125 in.s_addr = htonl(np->in_nip); 2126 if (l == 0) { 2127 /* 2128 * Check to see if there is an existing NAT 2129 * setup for this IP address pair. 2130 */ 2131 hm = nat_hostmap(np, fin->fin_src, fin->fin_dst, 2132 in, 0, ifs); 2133 if (hm != NULL) 2134 in.s_addr = hm->hm_mapip.s_addr; 2135 } else if ((l == 1) && (hm != NULL)) { 2136 fr_hostmapdel(&hm); 2137 } 2138 in.s_addr = ntohl(in.s_addr); 2139 2140 nat->nat_hm = hm; 2141 2142 if ((np->in_outmsk == 0xffffffff) && (np->in_pnext == 0)) { 2143 if (l > 0) 2144 return -1; 2145 } 2146 2147 if (np->in_redir == NAT_BIMAP && 2148 np->in_inmsk == np->in_outmsk) { 2149 /* 2150 * map the address block in a 1:1 fashion 2151 */ 2152 in.s_addr = np->in_outip; 2153 in.s_addr |= fin->fin_saddr & ~np->in_inmsk; 2154 in.s_addr = ntohl(in.s_addr); 2155 2156 } else if (np->in_redir & NAT_MAPBLK) { 2157 if ((l >= np->in_ppip) || ((l > 0) && 2158 !(flags & IPN_TCPUDP))) 2159 return -1; 2160 /* 2161 * map-block - Calculate destination address. 2162 */ 2163 in.s_addr = ntohl(fin->fin_saddr); 2164 in.s_addr &= ntohl(~np->in_inmsk); 2165 inb.s_addr = in.s_addr; 2166 in.s_addr /= np->in_ippip; 2167 in.s_addr &= ntohl(~np->in_outmsk); 2168 in.s_addr += ntohl(np->in_outip); 2169 /* 2170 * Calculate destination port. 2171 */ 2172 if ((flags & IPN_TCPUDP) && 2173 (np->in_ppip != 0)) { 2174 port = ntohs(sport) + l; 2175 port %= np->in_ppip; 2176 port += np->in_ppip * 2177 (inb.s_addr % np->in_ippip); 2178 port += MAPBLK_MINPORT; 2179 port = htons(port); 2180 } 2181 2182 } else if ((np->in_outip == 0) && 2183 (np->in_outmsk == 0xffffffff)) { 2184 /* 2185 * 0/32 - use the interface's IP address. 2186 */ 2187 if ((l > 0) || 2188 fr_ifpaddr(4, FRI_NORMAL, fin->fin_ifp, 2189 &in, NULL, fin->fin_ifs) == -1) 2190 return -1; 2191 in.s_addr = ntohl(in.s_addr); 2192 2193 } else if ((np->in_outip == 0) && (np->in_outmsk == 0)) { 2194 /* 2195 * 0/0 - use the original source address/port. 2196 */ 2197 if (l > 0) 2198 return -1; 2199 in.s_addr = ntohl(fin->fin_saddr); 2200 2201 } else if ((np->in_outmsk != 0xffffffff) && 2202 (np->in_pnext == 0) && ((l > 0) || (hm == NULL))) 2203 np->in_nip++; 2204 2205 natl = NULL; 2206 2207 if ((flags & IPN_TCPUDP) && 2208 ((np->in_redir & NAT_MAPBLK) == 0) && 2209 (np->in_flags & IPN_AUTOPORTMAP)) { 2210 /* 2211 * "ports auto" (without map-block) 2212 */ 2213 if ((l > 0) && (l % np->in_ppip == 0)) { 2214 if (l > np->in_space) { 2215 return -1; 2216 } else if ((l > np->in_ppip) && 2217 np->in_outmsk != 0xffffffff) 2218 np->in_nip++; 2219 } 2220 if (np->in_ppip != 0) { 2221 port = ntohs(sport); 2222 port += (l % np->in_ppip); 2223 port %= np->in_ppip; 2224 port += np->in_ppip * 2225 (ntohl(fin->fin_saddr) % 2226 np->in_ippip); 2227 port += MAPBLK_MINPORT; 2228 port = htons(port); 2229 } 2230 2231 } else if (((np->in_redir & NAT_MAPBLK) == 0) && 2232 (flags & IPN_TCPUDPICMP) && (np->in_pnext != 0)) { 2233 /* 2234 * Standard port translation. Select next port. 2235 */ 2236 if (np->in_flags & IPN_SEQUENTIAL) { 2237 port = np->in_pnext; 2238 } else { 2239 port = ipf_random() % (ntohs(np->in_pmax) - 2240 ntohs(np->in_pmin) + 1); 2241 port += ntohs(np->in_pmin); 2242 } 2243 port = htons(port); 2244 np->in_pnext++; 2245 2246 if (np->in_pnext > ntohs(np->in_pmax)) { 2247 np->in_pnext = ntohs(np->in_pmin); 2248 if (np->in_outmsk != 0xffffffff) 2249 np->in_nip++; 2250 } 2251 } 2252 2253 if (np->in_flags & IPN_IPRANGE) { 2254 if (np->in_nip > ntohl(np->in_outmsk)) 2255 np->in_nip = ntohl(np->in_outip); 2256 } else { 2257 if ((np->in_outmsk != 0xffffffff) && 2258 ((np->in_nip + 1) & ntohl(np->in_outmsk)) > 2259 ntohl(np->in_outip)) 2260 np->in_nip = ntohl(np->in_outip) + 1; 2261 } 2262 2263 if ((port == 0) && (flags & (IPN_TCPUDPICMP|IPN_ICMPQUERY))) 2264 port = sport; 2265 2266 /* 2267 * Here we do a lookup of the connection as seen from 2268 * the outside. If an IP# pair already exists, try 2269 * again. So if you have A->B becomes C->B, you can 2270 * also have D->E become C->E but not D->B causing 2271 * another C->B. Also take protocol and ports into 2272 * account when determining whether a pre-existing 2273 * NAT setup will cause an external conflict where 2274 * this is appropriate. 2275 */ 2276 inb.s_addr = htonl(in.s_addr); 2277 sp = fin->fin_data[0]; 2278 dp = fin->fin_data[1]; 2279 fin->fin_data[0] = fin->fin_data[1]; 2280 fin->fin_data[1] = htons(port); 2281 natl = nat_inlookup(fin, flags & ~(SI_WILDP|NAT_SEARCH), 2282 (u_int)fin->fin_p, fin->fin_dst, inb); 2283 fin->fin_data[0] = sp; 2284 fin->fin_data[1] = dp; 2285 2286 /* 2287 * Has the search wrapped around and come back to the 2288 * start ? 2289 */ 2290 if ((natl != NULL) && 2291 (np->in_pnext != 0) && (st_port == np->in_pnext) && 2292 (np->in_nip != 0) && (st_ip == np->in_nip)) 2293 return -1; 2294 l++; 2295 } while (natl != NULL); 2296 2297 if (np->in_space > 0) 2298 np->in_space--; 2299 2300 /* Setup the NAT table */ 2301 nat->nat_inip = fin->fin_src; 2302 nat->nat_outip.s_addr = htonl(in.s_addr); 2303 nat->nat_oip = fin->fin_dst; 2304 if (nat->nat_hm == NULL) 2305 nat->nat_hm = nat_hostmap(np, fin->fin_src, fin->fin_dst, 2306 nat->nat_outip, 0, ifs); 2307 2308 if (flags & IPN_TCPUDP) { 2309 nat->nat_inport = sport; 2310 nat->nat_outport = port; /* sport */ 2311 nat->nat_oport = dport; 2312 ((tcphdr_t *)fin->fin_dp)->th_sport = port; 2313 } else if (flags & IPN_ICMPQUERY) { 2314 ((icmphdr_t *)fin->fin_dp)->icmp_id = port; 2315 nat->nat_inport = port; 2316 nat->nat_outport = port; 2317 } 2318 2319 ni->nai_ip.s_addr = in.s_addr; 2320 ni->nai_port = port; 2321 ni->nai_nport = dport; 2322 return 0; 2323 } 2324 2325 2326 /* ------------------------------------------------------------------------ */ 2327 /* Function: nat_newrdr */ 2328 /* Returns: int - -1 == error, 0 == success (no move), 1 == success and */ 2329 /* allow rule to be moved if IPN_ROUNDR is set. */ 2330 /* Parameters: fin(I) - pointer to packet information */ 2331 /* nat(I) - pointer to NAT entry */ 2332 /* ni(I) - pointer to structure with misc. information needed */ 2333 /* to create new NAT entry. */ 2334 /* */ 2335 /* ni.nai_ip is passed in uninitialised and must be set, in host byte order,*/ 2336 /* to the new IP address for the translation. */ 2337 /* ------------------------------------------------------------------------ */ 2338 static INLINE int nat_newrdr(fin, nat, ni) 2339 fr_info_t *fin; 2340 nat_t *nat; 2341 natinfo_t *ni; 2342 { 2343 u_short nport, dport, sport; 2344 struct in_addr in, inb; 2345 u_short sp, dp; 2346 hostmap_t *hm; 2347 u_32_t flags; 2348 ipnat_t *np; 2349 nat_t *natl; 2350 int move; 2351 ipf_stack_t *ifs = fin->fin_ifs; 2352 2353 move = 1; 2354 hm = NULL; 2355 in.s_addr = 0; 2356 np = ni->nai_np; 2357 flags = ni->nai_flags; 2358 sport = ni->nai_sport; 2359 dport = ni->nai_dport; 2360 2361 /* 2362 * If the matching rule has IPN_STICKY set, then we want to have the 2363 * same rule kick in as before. Why would this happen? If you have 2364 * a collection of rdr rules with "round-robin sticky", the current 2365 * packet might match a different one to the previous connection but 2366 * we want the same destination to be used. 2367 */ 2368 if ((np->in_flags & (IPN_ROUNDR|IPN_STICKY)) == 2369 (IPN_ROUNDR|IPN_STICKY)) { 2370 hm = nat_hostmap(NULL, fin->fin_src, fin->fin_dst, in, 2371 (u_32_t)dport, ifs); 2372 if (hm != NULL) { 2373 in.s_addr = ntohl(hm->hm_mapip.s_addr); 2374 np = hm->hm_ipnat; 2375 ni->nai_np = np; 2376 move = 0; 2377 } 2378 } 2379 2380 /* 2381 * Otherwise, it's an inbound packet. Most likely, we don't 2382 * want to rewrite source ports and source addresses. Instead, 2383 * we want to rewrite to a fixed internal address and fixed 2384 * internal port. 2385 */ 2386 if (np->in_flags & IPN_SPLIT) { 2387 in.s_addr = np->in_nip; 2388 2389 if ((np->in_flags & (IPN_ROUNDR|IPN_STICKY)) == IPN_STICKY) { 2390 hm = nat_hostmap(np, fin->fin_src, fin->fin_dst, 2391 in, (u_32_t)dport, ifs); 2392 if (hm != NULL) { 2393 in.s_addr = hm->hm_mapip.s_addr; 2394 move = 0; 2395 } 2396 } 2397 2398 if (hm == NULL || hm->hm_ref == 1) { 2399 if (np->in_inip == htonl(in.s_addr)) { 2400 np->in_nip = ntohl(np->in_inmsk); 2401 move = 0; 2402 } else { 2403 np->in_nip = ntohl(np->in_inip); 2404 } 2405 } 2406 2407 } else if ((np->in_inip == 0) && (np->in_inmsk == 0xffffffff)) { 2408 /* 2409 * 0/32 - use the interface's IP address. 2410 */ 2411 if (fr_ifpaddr(4, FRI_NORMAL, fin->fin_ifp, &in, NULL, 2412 fin->fin_ifs) == -1) 2413 return -1; 2414 in.s_addr = ntohl(in.s_addr); 2415 2416 } else if ((np->in_inip == 0) && (np->in_inmsk== 0)) { 2417 /* 2418 * 0/0 - use the original destination address/port. 2419 */ 2420 in.s_addr = ntohl(fin->fin_daddr); 2421 2422 } else if (np->in_redir == NAT_BIMAP && 2423 np->in_inmsk == np->in_outmsk) { 2424 /* 2425 * map the address block in a 1:1 fashion 2426 */ 2427 in.s_addr = np->in_inip; 2428 in.s_addr |= fin->fin_daddr & ~np->in_inmsk; 2429 in.s_addr = ntohl(in.s_addr); 2430 } else { 2431 in.s_addr = ntohl(np->in_inip); 2432 } 2433 2434 if ((np->in_pnext == 0) || ((flags & NAT_NOTRULEPORT) != 0)) 2435 nport = dport; 2436 else { 2437 /* 2438 * Whilst not optimized for the case where 2439 * pmin == pmax, the gain is not significant. 2440 */ 2441 if (((np->in_flags & IPN_FIXEDDPORT) == 0) && 2442 (np->in_pmin != np->in_pmax)) { 2443 nport = ntohs(dport) - ntohs(np->in_pmin) + 2444 ntohs(np->in_pnext); 2445 nport = htons(nport); 2446 } else 2447 nport = np->in_pnext; 2448 } 2449 2450 /* 2451 * When the redirect-to address is set to 0.0.0.0, just 2452 * assume a blank `forwarding' of the packet. We don't 2453 * setup any translation for this either. 2454 */ 2455 if (in.s_addr == 0) { 2456 if (nport == dport) 2457 return -1; 2458 in.s_addr = ntohl(fin->fin_daddr); 2459 } 2460 2461 /* 2462 * Check to see if this redirect mapping already exists and if 2463 * it does, return "failure" (allowing it to be created will just 2464 * cause one or both of these "connections" to stop working.) 2465 */ 2466 inb.s_addr = htonl(in.s_addr); 2467 sp = fin->fin_data[0]; 2468 dp = fin->fin_data[1]; 2469 fin->fin_data[1] = fin->fin_data[0]; 2470 fin->fin_data[0] = ntohs(nport); 2471 natl = nat_outlookup(fin, flags & ~(SI_WILDP|NAT_SEARCH), 2472 (u_int)fin->fin_p, inb, fin->fin_src); 2473 fin->fin_data[0] = sp; 2474 fin->fin_data[1] = dp; 2475 if (natl != NULL) 2476 return (-1); 2477 2478 nat->nat_inip.s_addr = htonl(in.s_addr); 2479 nat->nat_outip = fin->fin_dst; 2480 nat->nat_oip = fin->fin_src; 2481 2482 ni->nai_ip.s_addr = in.s_addr; 2483 ni->nai_nport = nport; 2484 ni->nai_port = sport; 2485 2486 if (flags & IPN_TCPUDP) { 2487 nat->nat_inport = nport; 2488 nat->nat_outport = dport; 2489 nat->nat_oport = sport; 2490 ((tcphdr_t *)fin->fin_dp)->th_dport = nport; 2491 } else if (flags & IPN_ICMPQUERY) { 2492 ((icmphdr_t *)fin->fin_dp)->icmp_id = nport; 2493 nat->nat_inport = nport; 2494 nat->nat_outport = nport; 2495 } 2496 2497 return move; 2498 } 2499 2500 /* ------------------------------------------------------------------------ */ 2501 /* Function: nat_new */ 2502 /* Returns: nat_t* - NULL == failure to create new NAT structure, */ 2503 /* else pointer to new NAT structure */ 2504 /* Parameters: fin(I) - pointer to packet information */ 2505 /* np(I) - pointer to NAT rule */ 2506 /* natsave(I) - pointer to where to store NAT struct pointer */ 2507 /* flags(I) - flags describing the current packet */ 2508 /* direction(I) - direction of packet (in/out) */ 2509 /* Write Lock: ipf_nat */ 2510 /* */ 2511 /* Attempts to create a new NAT entry. Does not actually change the packet */ 2512 /* in any way. */ 2513 /* */ 2514 /* This fucntion is in three main parts: (1) deal with creating a new NAT */ 2515 /* structure for a "MAP" rule (outgoing NAT translation); (2) deal with */ 2516 /* creating a new NAT structure for a "RDR" rule (incoming NAT translation) */ 2517 /* and (3) building that structure and putting it into the NAT table(s). */ 2518 /* ------------------------------------------------------------------------ */ 2519 nat_t *nat_new(fin, np, natsave, flags, direction) 2520 fr_info_t *fin; 2521 ipnat_t *np; 2522 nat_t **natsave; 2523 u_int flags; 2524 int direction; 2525 { 2526 tcphdr_t *tcp = NULL; 2527 hostmap_t *hm = NULL; 2528 nat_t *nat, *natl; 2529 u_int nflags; 2530 natinfo_t ni; 2531 int move; 2532 ipf_stack_t *ifs = fin->fin_ifs; 2533 2534 /* 2535 * Trigger automatic call to nat_flushtable() if the 2536 * table has reached capcity specified by hi watermark. 2537 */ 2538 if (NAT_TAB_WATER_LEVEL(ifs) > ifs->ifs_nat_flush_level_hi) 2539 ifs->ifs_nat_doflush = 1; 2540 2541 /* 2542 * If automatic flushing did not do its job, and the table 2543 * has filled up, don't try to create a new entry. 2544 */ 2545 if (ifs->ifs_nat_stats.ns_inuse >= ifs->ifs_ipf_nattable_max) { 2546 ifs->ifs_nat_stats.ns_memfail++; 2547 return NULL; 2548 } 2549 2550 move = 1; 2551 nflags = np->in_flags & flags; 2552 nflags &= NAT_FROMRULE; 2553 2554 ni.nai_np = np; 2555 ni.nai_nflags = nflags; 2556 ni.nai_flags = flags; 2557 2558 /* Give me a new nat */ 2559 KMALLOC(nat, nat_t *); 2560 if (nat == NULL) { 2561 ifs->ifs_nat_stats.ns_memfail++; 2562 /* 2563 * Try to automatically tune the max # of entries in the 2564 * table allowed to be less than what will cause kmem_alloc() 2565 * to fail and try to eliminate panics due to out of memory 2566 * conditions arising. 2567 */ 2568 if (ifs->ifs_ipf_nattable_max > ifs->ifs_ipf_nattable_sz) { 2569 ifs->ifs_ipf_nattable_max = ifs->ifs_nat_stats.ns_inuse - 100; 2570 printf("ipf_nattable_max reduced to %d\n", 2571 ifs->ifs_ipf_nattable_max); 2572 } 2573 return NULL; 2574 } 2575 2576 if (flags & IPN_TCPUDP) { 2577 tcp = fin->fin_dp; 2578 ni.nai_sport = htons(fin->fin_sport); 2579 ni.nai_dport = htons(fin->fin_dport); 2580 } else if (flags & IPN_ICMPQUERY) { 2581 /* 2582 * In the ICMP query NAT code, we translate the ICMP id fields 2583 * to make them unique. This is indepedent of the ICMP type 2584 * (e.g. in the unlikely event that a host sends an echo and 2585 * an tstamp request with the same id, both packets will have 2586 * their ip address/id field changed in the same way). 2587 */ 2588 /* The icmp_id field is used by the sender to identify the 2589 * process making the icmp request. (the receiver justs 2590 * copies it back in its response). So, it closely matches 2591 * the concept of source port. We overlay sport, so we can 2592 * maximally reuse the existing code. 2593 */ 2594 ni.nai_sport = ((icmphdr_t *)fin->fin_dp)->icmp_id; 2595 ni.nai_dport = ni.nai_sport; 2596 } 2597 2598 bzero((char *)nat, sizeof(*nat)); 2599 nat->nat_flags = flags; 2600 nat->nat_redir = np->in_redir; 2601 2602 if ((flags & NAT_SLAVE) == 0) { 2603 MUTEX_ENTER(&ifs->ifs_ipf_nat_new); 2604 } 2605 2606 /* 2607 * Search the current table for a match. 2608 */ 2609 if (direction == NAT_OUTBOUND) { 2610 /* 2611 * We can now arrange to call this for the same connection 2612 * because ipf_nat_new doesn't protect the code path into 2613 * this function. 2614 */ 2615 natl = nat_outlookup(fin, nflags, (u_int)fin->fin_p, 2616 fin->fin_src, fin->fin_dst); 2617 if (natl != NULL) { 2618 KFREE(nat); 2619 nat = natl; 2620 goto done; 2621 } 2622 2623 move = nat_newmap(fin, nat, &ni); 2624 if (move == -1) 2625 goto badnat; 2626 2627 np = ni.nai_np; 2628 } else { 2629 /* 2630 * NAT_INBOUND is used only for redirects rules 2631 */ 2632 natl = nat_inlookup(fin, nflags, (u_int)fin->fin_p, 2633 fin->fin_src, fin->fin_dst); 2634 if (natl != NULL) { 2635 KFREE(nat); 2636 nat = natl; 2637 goto done; 2638 } 2639 2640 move = nat_newrdr(fin, nat, &ni); 2641 if (move == -1) 2642 goto badnat; 2643 2644 np = ni.nai_np; 2645 } 2646 2647 if ((move == 1) && (np->in_flags & IPN_ROUNDR)) { 2648 if (np->in_redir == NAT_REDIRECT) { 2649 nat_delrdr(np); 2650 nat_addrdr(np, ifs); 2651 } else if (np->in_redir == NAT_MAP) { 2652 nat_delnat(np); 2653 nat_addnat(np, ifs); 2654 } 2655 } 2656 2657 if (nat_finalise(fin, nat, &ni, tcp, natsave, direction) == -1) { 2658 goto badnat; 2659 } 2660 2661 nat_calc_chksum_diffs(nat); 2662 2663 if (flags & SI_WILDP) 2664 ifs->ifs_nat_stats.ns_wilds++; 2665 fin->fin_flx |= FI_NEWNAT; 2666 goto done; 2667 badnat: 2668 ifs->ifs_nat_stats.ns_badnat++; 2669 if ((hm = nat->nat_hm) != NULL) 2670 fr_hostmapdel(&hm); 2671 KFREE(nat); 2672 nat = NULL; 2673 done: 2674 if ((flags & NAT_SLAVE) == 0) { 2675 MUTEX_EXIT(&ifs->ifs_ipf_nat_new); 2676 } 2677 return nat; 2678 } 2679 2680 2681 /* ------------------------------------------------------------------------ */ 2682 /* Function: nat_finalise */ 2683 /* Returns: int - 0 == sucess, -1 == failure */ 2684 /* Parameters: fin(I) - pointer to packet information */ 2685 /* nat(I) - pointer to NAT entry */ 2686 /* ni(I) - pointer to structure with misc. information needed */ 2687 /* to create new NAT entry. */ 2688 /* Write Lock: ipf_nat */ 2689 /* */ 2690 /* This is the tail end of constructing a new NAT entry and is the same */ 2691 /* for both IPv4 and IPv6. */ 2692 /* ------------------------------------------------------------------------ */ 2693 /*ARGSUSED*/ 2694 static INLINE int nat_finalise(fin, nat, ni, tcp, natsave, direction) 2695 fr_info_t *fin; 2696 nat_t *nat; 2697 natinfo_t *ni; 2698 tcphdr_t *tcp; 2699 nat_t **natsave; 2700 int direction; 2701 { 2702 frentry_t *fr; 2703 ipnat_t *np; 2704 ipf_stack_t *ifs = fin->fin_ifs; 2705 2706 np = ni->nai_np; 2707 2708 COPYIFNAME(fin->fin_ifp, nat->nat_ifnames[0], fin->fin_v); 2709 2710 #ifdef IPFILTER_SYNC 2711 if ((nat->nat_flags & SI_CLONE) == 0) 2712 nat->nat_sync = ipfsync_new(SMC_NAT, fin, nat); 2713 #endif 2714 2715 nat->nat_me = natsave; 2716 nat->nat_dir = direction; 2717 nat->nat_ifps[0] = np->in_ifps[0]; 2718 nat->nat_ifps[1] = np->in_ifps[1]; 2719 nat->nat_ptr = np; 2720 nat->nat_p = fin->fin_p; 2721 nat->nat_v = fin->fin_v; 2722 nat->nat_mssclamp = np->in_mssclamp; 2723 fr = fin->fin_fr; 2724 nat->nat_fr = fr; 2725 2726 if ((np->in_apr != NULL) && ((ni->nai_flags & NAT_SLAVE) == 0)) 2727 if (appr_new(fin, nat) == -1) 2728 return -1; 2729 2730 if (nat_insert(nat, fin->fin_rev, ifs) == 0) { 2731 if (ifs->ifs_nat_logging) 2732 nat_log(nat, (u_int)np->in_redir, ifs); 2733 np->in_use++; 2734 if (fr != NULL) { 2735 MUTEX_ENTER(&fr->fr_lock); 2736 fr->fr_ref++; 2737 MUTEX_EXIT(&fr->fr_lock); 2738 } 2739 return 0; 2740 } 2741 2742 /* 2743 * nat_insert failed, so cleanup time... 2744 */ 2745 return -1; 2746 } 2747 2748 2749 /* ------------------------------------------------------------------------ */ 2750 /* Function: nat_insert */ 2751 /* Returns: int - 0 == sucess, -1 == failure */ 2752 /* Parameters: nat(I) - pointer to NAT structure */ 2753 /* rev(I) - flag indicating forward/reverse direction of packet */ 2754 /* Write Lock: ipf_nat */ 2755 /* */ 2756 /* Insert a NAT entry into the hash tables for searching and add it to the */ 2757 /* list of active NAT entries. Adjust global counters when complete. */ 2758 /* ------------------------------------------------------------------------ */ 2759 int nat_insert(nat, rev, ifs) 2760 nat_t *nat; 2761 int rev; 2762 ipf_stack_t *ifs; 2763 { 2764 u_int hv1, hv2; 2765 nat_t **natp; 2766 2767 /* 2768 * Try and return an error as early as possible, so calculate the hash 2769 * entry numbers first and then proceed. 2770 */ 2771 if ((nat->nat_flags & (SI_W_SPORT|SI_W_DPORT)) == 0) { 2772 hv1 = NAT_HASH_FN(nat->nat_inip.s_addr, nat->nat_inport, 2773 0xffffffff); 2774 hv1 = NAT_HASH_FN(nat->nat_oip.s_addr, hv1 + nat->nat_oport, 2775 ifs->ifs_ipf_nattable_sz); 2776 hv2 = NAT_HASH_FN(nat->nat_outip.s_addr, nat->nat_outport, 2777 0xffffffff); 2778 hv2 = NAT_HASH_FN(nat->nat_oip.s_addr, hv2 + nat->nat_oport, 2779 ifs->ifs_ipf_nattable_sz); 2780 } else { 2781 hv1 = NAT_HASH_FN(nat->nat_inip.s_addr, 0, 0xffffffff); 2782 hv1 = NAT_HASH_FN(nat->nat_oip.s_addr, hv1, 2783 ifs->ifs_ipf_nattable_sz); 2784 hv2 = NAT_HASH_FN(nat->nat_outip.s_addr, 0, 0xffffffff); 2785 hv2 = NAT_HASH_FN(nat->nat_oip.s_addr, hv2, 2786 ifs->ifs_ipf_nattable_sz); 2787 } 2788 2789 if (ifs->ifs_nat_stats.ns_bucketlen[0][hv1] >= ifs->ifs_fr_nat_maxbucket || 2790 ifs->ifs_nat_stats.ns_bucketlen[1][hv2] >= ifs->ifs_fr_nat_maxbucket) { 2791 return -1; 2792 } 2793 2794 nat->nat_hv[0] = hv1; 2795 nat->nat_hv[1] = hv2; 2796 2797 MUTEX_INIT(&nat->nat_lock, "nat entry lock"); 2798 2799 nat->nat_rev = rev; 2800 nat->nat_ref = 1; 2801 nat->nat_bytes[0] = 0; 2802 nat->nat_pkts[0] = 0; 2803 nat->nat_bytes[1] = 0; 2804 nat->nat_pkts[1] = 0; 2805 2806 nat->nat_ifnames[0][LIFNAMSIZ - 1] = '\0'; 2807 nat->nat_ifps[0] = fr_resolvenic(nat->nat_ifnames[0], 4, ifs); 2808 2809 if (nat->nat_ifnames[1][0] !='\0') { 2810 nat->nat_ifnames[1][LIFNAMSIZ - 1] = '\0'; 2811 nat->nat_ifps[1] = fr_resolvenic(nat->nat_ifnames[1], 4, ifs); 2812 } else { 2813 (void) strncpy(nat->nat_ifnames[1], nat->nat_ifnames[0], 2814 LIFNAMSIZ); 2815 nat->nat_ifnames[1][LIFNAMSIZ - 1] = '\0'; 2816 nat->nat_ifps[1] = nat->nat_ifps[0]; 2817 } 2818 2819 nat->nat_next = ifs->ifs_nat_instances; 2820 nat->nat_pnext = &ifs->ifs_nat_instances; 2821 if (ifs->ifs_nat_instances) 2822 ifs->ifs_nat_instances->nat_pnext = &nat->nat_next; 2823 ifs->ifs_nat_instances = nat; 2824 2825 natp = &ifs->ifs_nat_table[0][hv1]; 2826 if (*natp) 2827 (*natp)->nat_phnext[0] = &nat->nat_hnext[0]; 2828 nat->nat_phnext[0] = natp; 2829 nat->nat_hnext[0] = *natp; 2830 *natp = nat; 2831 ifs->ifs_nat_stats.ns_bucketlen[0][hv1]++; 2832 2833 natp = &ifs->ifs_nat_table[1][hv2]; 2834 if (*natp) 2835 (*natp)->nat_phnext[1] = &nat->nat_hnext[1]; 2836 nat->nat_phnext[1] = natp; 2837 nat->nat_hnext[1] = *natp; 2838 *natp = nat; 2839 ifs->ifs_nat_stats.ns_bucketlen[1][hv2]++; 2840 2841 fr_setnatqueue(nat, rev, ifs); 2842 2843 ifs->ifs_nat_stats.ns_added++; 2844 ifs->ifs_nat_stats.ns_inuse++; 2845 return 0; 2846 } 2847 2848 2849 /* ------------------------------------------------------------------------ */ 2850 /* Function: nat_icmperrorlookup */ 2851 /* Returns: nat_t* - point to matching NAT structure */ 2852 /* Parameters: fin(I) - pointer to packet information */ 2853 /* dir(I) - direction of packet (in/out) */ 2854 /* */ 2855 /* Check if the ICMP error message is related to an existing TCP, UDP or */ 2856 /* ICMP query nat entry. It is assumed that the packet is already of the */ 2857 /* the required length. */ 2858 /* ------------------------------------------------------------------------ */ 2859 nat_t *nat_icmperrorlookup(fin, dir) 2860 fr_info_t *fin; 2861 int dir; 2862 { 2863 int flags = 0, minlen; 2864 icmphdr_t *orgicmp; 2865 tcphdr_t *tcp = NULL; 2866 u_short data[2]; 2867 nat_t *nat; 2868 ip_t *oip; 2869 u_int p; 2870 2871 /* 2872 * Does it at least have the return (basic) IP header ? 2873 * Only a basic IP header (no options) should be with an ICMP error 2874 * header. Also, if it's not an error type, then return. 2875 */ 2876 if ((fin->fin_hlen != sizeof(ip_t)) || !(fin->fin_flx & FI_ICMPERR)) 2877 return NULL; 2878 2879 /* 2880 * Check packet size 2881 */ 2882 oip = (ip_t *)((char *)fin->fin_dp + 8); 2883 minlen = IP_HL(oip) << 2; 2884 if ((minlen < sizeof(ip_t)) || 2885 (fin->fin_plen < ICMPERR_IPICMPHLEN + minlen)) 2886 return NULL; 2887 /* 2888 * Is the buffer big enough for all of it ? It's the size of the IP 2889 * header claimed in the encapsulated part which is of concern. It 2890 * may be too big to be in this buffer but not so big that it's 2891 * outside the ICMP packet, leading to TCP deref's causing problems. 2892 * This is possible because we don't know how big oip_hl is when we 2893 * do the pullup early in fr_check() and thus can't gaurantee it is 2894 * all here now. 2895 */ 2896 #ifdef _KERNEL 2897 { 2898 mb_t *m; 2899 2900 m = fin->fin_m; 2901 # if defined(MENTAT) 2902 if ((char *)oip + fin->fin_dlen - ICMPERR_ICMPHLEN > (char *)m->b_wptr) 2903 return NULL; 2904 # else 2905 if ((char *)oip + fin->fin_dlen - ICMPERR_ICMPHLEN > 2906 (char *)fin->fin_ip + M_LEN(m)) 2907 return NULL; 2908 # endif 2909 } 2910 #endif 2911 2912 if (fin->fin_daddr != oip->ip_src.s_addr) 2913 return NULL; 2914 2915 p = oip->ip_p; 2916 if (p == IPPROTO_TCP) 2917 flags = IPN_TCP; 2918 else if (p == IPPROTO_UDP) 2919 flags = IPN_UDP; 2920 else if (p == IPPROTO_ICMP) { 2921 orgicmp = (icmphdr_t *)((char *)oip + (IP_HL(oip) << 2)); 2922 2923 /* see if this is related to an ICMP query */ 2924 if (nat_icmpquerytype4(orgicmp->icmp_type)) { 2925 data[0] = fin->fin_data[0]; 2926 data[1] = fin->fin_data[1]; 2927 fin->fin_data[0] = 0; 2928 fin->fin_data[1] = orgicmp->icmp_id; 2929 2930 flags = IPN_ICMPERR|IPN_ICMPQUERY; 2931 /* 2932 * NOTE : dir refers to the direction of the original 2933 * ip packet. By definition the icmp error 2934 * message flows in the opposite direction. 2935 */ 2936 if (dir == NAT_INBOUND) 2937 nat = nat_inlookup(fin, flags, p, oip->ip_dst, 2938 oip->ip_src); 2939 else 2940 nat = nat_outlookup(fin, flags, p, oip->ip_dst, 2941 oip->ip_src); 2942 fin->fin_data[0] = data[0]; 2943 fin->fin_data[1] = data[1]; 2944 return nat; 2945 } 2946 } 2947 2948 if (flags & IPN_TCPUDP) { 2949 minlen += 8; /* + 64bits of data to get ports */ 2950 if (fin->fin_plen < ICMPERR_IPICMPHLEN + minlen) 2951 return NULL; 2952 2953 data[0] = fin->fin_data[0]; 2954 data[1] = fin->fin_data[1]; 2955 tcp = (tcphdr_t *)((char *)oip + (IP_HL(oip) << 2)); 2956 fin->fin_data[0] = ntohs(tcp->th_dport); 2957 fin->fin_data[1] = ntohs(tcp->th_sport); 2958 2959 if (dir == NAT_INBOUND) { 2960 nat = nat_inlookup(fin, flags, p, oip->ip_dst, 2961 oip->ip_src); 2962 } else { 2963 nat = nat_outlookup(fin, flags, p, oip->ip_dst, 2964 oip->ip_src); 2965 } 2966 fin->fin_data[0] = data[0]; 2967 fin->fin_data[1] = data[1]; 2968 return nat; 2969 } 2970 if (dir == NAT_INBOUND) 2971 return nat_inlookup(fin, 0, p, oip->ip_dst, oip->ip_src); 2972 else 2973 return nat_outlookup(fin, 0, p, oip->ip_dst, oip->ip_src); 2974 } 2975 2976 2977 /* ------------------------------------------------------------------------ */ 2978 /* Function: nat_icmperror */ 2979 /* Returns: nat_t* - point to matching NAT structure */ 2980 /* Parameters: fin(I) - pointer to packet information */ 2981 /* nflags(I) - NAT flags for this packet */ 2982 /* dir(I) - direction of packet (in/out) */ 2983 /* */ 2984 /* Fix up an ICMP packet which is an error message for an existing NAT */ 2985 /* session. This will correct both packet header data and checksums. */ 2986 /* */ 2987 /* This should *ONLY* be used for incoming ICMP error packets to make sure */ 2988 /* a NAT'd ICMP packet gets correctly recognised. */ 2989 /* ------------------------------------------------------------------------ */ 2990 nat_t *nat_icmperror(fin, nflags, dir) 2991 fr_info_t *fin; 2992 u_int *nflags; 2993 int dir; 2994 { 2995 u_32_t sum1, sum2, sumd, psum1, psum2, psumd, sumd2; 2996 struct in_addr in; 2997 icmphdr_t *icmp, *orgicmp; 2998 int dlen; 2999 udphdr_t *udp; 3000 tcphdr_t *tcp; 3001 nat_t *nat; 3002 ip_t *oip; 3003 if ((fin->fin_flx & (FI_SHORT|FI_FRAGBODY))) 3004 return NULL; 3005 3006 /* 3007 * nat_icmperrorlookup() looks up nat entry associated with the 3008 * offending IP packet and returns pointer to the entry, or NULL 3009 * if packet wasn't natted or for `defective' packets. 3010 */ 3011 3012 if ((fin->fin_v != 4) || !(nat = nat_icmperrorlookup(fin, dir))) 3013 return NULL; 3014 3015 sumd2 = 0; 3016 *nflags = IPN_ICMPERR; 3017 icmp = fin->fin_dp; 3018 oip = (ip_t *)&icmp->icmp_ip; 3019 udp = (udphdr_t *)((((char *)oip) + (IP_HL(oip) << 2))); 3020 tcp = (tcphdr_t *)udp; 3021 dlen = fin->fin_plen - ((char *)udp - (char *)fin->fin_ip); 3022 3023 /* 3024 * Need to adjust ICMP header to include the real IP#'s and 3025 * port #'s. There are three steps required. 3026 * 3027 * Step 1 3028 * Fix the IP addresses in the offending IP packet and update 3029 * ip header checksum to compensate for the change. 3030 * 3031 * No update needed here for icmp_cksum because the ICMP checksum 3032 * is calculated over the complete ICMP packet, which includes the 3033 * changed oip IP addresses and oip->ip_sum. These two changes 3034 * cancel each other out (if the delta for the IP address is x, 3035 * then the delta for ip_sum is minus x). 3036 */ 3037 3038 if (oip->ip_dst.s_addr == nat->nat_oip.s_addr) { 3039 sum1 = LONG_SUM(ntohl(oip->ip_src.s_addr)); 3040 in = nat->nat_inip; 3041 oip->ip_src = in; 3042 } else { 3043 sum1 = LONG_SUM(ntohl(oip->ip_dst.s_addr)); 3044 in = nat->nat_outip; 3045 oip->ip_dst = in; 3046 } 3047 3048 sum2 = LONG_SUM(ntohl(in.s_addr)); 3049 CALC_SUMD(sum1, sum2, sumd); 3050 fix_datacksum(&oip->ip_sum, sumd); 3051 3052 /* 3053 * Step 2 3054 * Perform other adjustments based on protocol of offending packet. 3055 */ 3056 3057 switch (oip->ip_p) { 3058 case IPPROTO_TCP : 3059 case IPPROTO_UDP : 3060 3061 /* 3062 * For offending TCP/UDP IP packets, translate the ports 3063 * based on the NAT specification. 3064 * 3065 * Advance notice : Now it becomes complicated :-) 3066 * 3067 * Since the port and IP addresse fields are both part 3068 * of the TCP/UDP checksum of the offending IP packet, 3069 * we need to adjust that checksum as well. 3070 * 3071 * To further complicate things, the TCP/UDP checksum 3072 * may not be present. We must check to see if the 3073 * length of the data portion is big enough to hold 3074 * the checksum. In the UDP case, a test to determine 3075 * if the checksum is even set is also required. 3076 * 3077 * Any changes to an IP address, port or checksum within 3078 * the ICMP packet requires a change to icmp_cksum. 3079 * 3080 * Be extremely careful here ... The change is dependent 3081 * upon whether or not the TCP/UPD checksum is present. 3082 * 3083 * If TCP/UPD checksum is present, the icmp_cksum must 3084 * compensate for checksum modification resulting from 3085 * IP address change only. Port change and resulting 3086 * data checksum adjustments cancel each other out. 3087 * 3088 * If TCP/UDP checksum is not present, icmp_cksum must 3089 * compensate for port change only. The IP address 3090 * change does not modify anything else in this case. 3091 */ 3092 3093 psum1 = 0; 3094 psum2 = 0; 3095 psumd = 0; 3096 3097 if ((tcp->th_dport == nat->nat_oport) && 3098 (tcp->th_sport != nat->nat_inport)) { 3099 3100 /* 3101 * Translate the source port. 3102 */ 3103 3104 psum1 = ntohs(tcp->th_sport); 3105 psum2 = ntohs(nat->nat_inport); 3106 tcp->th_sport = nat->nat_inport; 3107 3108 } else if ((tcp->th_sport == nat->nat_oport) && 3109 (tcp->th_dport != nat->nat_outport)) { 3110 3111 /* 3112 * Translate the destination port. 3113 */ 3114 3115 psum1 = ntohs(tcp->th_dport); 3116 psum2 = ntohs(nat->nat_outport); 3117 tcp->th_dport = nat->nat_outport; 3118 } 3119 3120 if ((oip->ip_p == IPPROTO_TCP) && (dlen >= 18)) { 3121 3122 /* 3123 * TCP checksum present. 3124 * 3125 * Adjust data checksum and icmp checksum to 3126 * compensate for any IP address change. 3127 */ 3128 3129 sum1 = ntohs(tcp->th_sum); 3130 fix_datacksum(&tcp->th_sum, sumd); 3131 sum2 = ntohs(tcp->th_sum); 3132 sumd2 = sumd << 1; 3133 CALC_SUMD(sum1, sum2, sumd); 3134 sumd2 += sumd; 3135 3136 /* 3137 * Also make data checksum adjustment to 3138 * compensate for any port change. 3139 */ 3140 3141 if (psum1 != psum2) { 3142 CALC_SUMD(psum1, psum2, psumd); 3143 fix_datacksum(&tcp->th_sum, psumd); 3144 } 3145 3146 } else if ((oip->ip_p == IPPROTO_UDP) && 3147 (dlen >= 8) && (udp->uh_sum != 0)) { 3148 3149 /* 3150 * The UDP checksum is present and set. 3151 * 3152 * Adjust data checksum and icmp checksum to 3153 * compensate for any IP address change. 3154 */ 3155 3156 sum1 = ntohs(udp->uh_sum); 3157 fix_datacksum(&udp->uh_sum, sumd); 3158 sum2 = ntohs(udp->uh_sum); 3159 sumd2 = sumd << 1; 3160 CALC_SUMD(sum1, sum2, sumd); 3161 sumd2 += sumd; 3162 3163 /* 3164 * Also make data checksum adjustment to 3165 * compensate for any port change. 3166 */ 3167 3168 if (psum1 != psum2) { 3169 CALC_SUMD(psum1, psum2, psumd); 3170 fix_datacksum(&udp->uh_sum, psumd); 3171 } 3172 3173 } else { 3174 3175 /* 3176 * Data checksum was not present. 3177 * 3178 * Compensate for any port change. 3179 */ 3180 3181 CALC_SUMD(psum2, psum1, psumd); 3182 sumd2 += psumd; 3183 } 3184 break; 3185 3186 case IPPROTO_ICMP : 3187 3188 orgicmp = (icmphdr_t *)udp; 3189 3190 if ((nat->nat_dir == NAT_OUTBOUND) && 3191 (orgicmp->icmp_id != nat->nat_inport) && 3192 (dlen >= 8)) { 3193 3194 /* 3195 * Fix ICMP checksum (of the offening ICMP 3196 * query packet) to compensate the change 3197 * in the ICMP id of the offending ICMP 3198 * packet. 3199 * 3200 * Since you modify orgicmp->icmp_id with 3201 * a delta (say x) and you compensate that 3202 * in origicmp->icmp_cksum with a delta 3203 * minus x, you don't have to adjust the 3204 * overall icmp->icmp_cksum 3205 */ 3206 3207 sum1 = ntohs(orgicmp->icmp_id); 3208 sum2 = ntohs(nat->nat_inport); 3209 CALC_SUMD(sum1, sum2, sumd); 3210 orgicmp->icmp_id = nat->nat_inport; 3211 fix_datacksum(&orgicmp->icmp_cksum, sumd); 3212 3213 } /* nat_dir can't be NAT_INBOUND for icmp queries */ 3214 3215 break; 3216 3217 default : 3218 3219 break; 3220 3221 } /* switch (oip->ip_p) */ 3222 3223 /* 3224 * Step 3 3225 * Make the adjustments to icmp checksum. 3226 */ 3227 3228 if (sumd2 != 0) { 3229 sumd2 = (sumd2 & 0xffff) + (sumd2 >> 16); 3230 sumd2 = (sumd2 & 0xffff) + (sumd2 >> 16); 3231 fix_incksum(&icmp->icmp_cksum, sumd2); 3232 } 3233 return nat; 3234 } 3235 3236 3237 /* 3238 * NB: these lookups don't lock access to the list, it assumed that it has 3239 * already been done! 3240 */ 3241 3242 /* ------------------------------------------------------------------------ */ 3243 /* Function: nat_inlookup */ 3244 /* Returns: nat_t* - NULL == no match, */ 3245 /* else pointer to matching NAT entry */ 3246 /* Parameters: fin(I) - pointer to packet information */ 3247 /* flags(I) - NAT flags for this packet */ 3248 /* p(I) - protocol for this packet */ 3249 /* src(I) - source IP address */ 3250 /* mapdst(I) - destination IP address */ 3251 /* */ 3252 /* Lookup a nat entry based on the mapped destination ip address/port and */ 3253 /* real source address/port. We use this lookup when receiving a packet, */ 3254 /* we're looking for a table entry, based on the destination address. */ 3255 /* */ 3256 /* NOTE: THE PACKET BEING CHECKED (IF FOUND) HAS A MAPPING ALREADY. */ 3257 /* */ 3258 /* NOTE: IT IS ASSUMED THAT ipf_nat IS ONLY HELD WITH A READ LOCK WHEN */ 3259 /* THIS FUNCTION IS CALLED WITH NAT_SEARCH SET IN nflags. */ 3260 /* */ 3261 /* flags -> relevant are IPN_UDP/IPN_TCP/IPN_ICMPQUERY that indicate if */ 3262 /* the packet is of said protocol */ 3263 /* ------------------------------------------------------------------------ */ 3264 nat_t *nat_inlookup(fin, flags, p, src, mapdst) 3265 fr_info_t *fin; 3266 u_int flags, p; 3267 struct in_addr src , mapdst; 3268 { 3269 u_short sport, dport; 3270 ipnat_t *ipn; 3271 u_int sflags; 3272 nat_t *nat; 3273 int nflags; 3274 u_32_t dst; 3275 void *ifp; 3276 u_int hv; 3277 ipf_stack_t *ifs = fin->fin_ifs; 3278 3279 if (fin != NULL) 3280 ifp = fin->fin_ifp; 3281 else 3282 ifp = NULL; 3283 sport = 0; 3284 dport = 0; 3285 dst = mapdst.s_addr; 3286 sflags = flags & NAT_TCPUDPICMP; 3287 3288 switch (p) 3289 { 3290 case IPPROTO_TCP : 3291 case IPPROTO_UDP : 3292 sport = htons(fin->fin_data[0]); 3293 dport = htons(fin->fin_data[1]); 3294 break; 3295 case IPPROTO_ICMP : 3296 if (flags & IPN_ICMPERR) 3297 sport = fin->fin_data[1]; 3298 else 3299 dport = fin->fin_data[1]; 3300 break; 3301 default : 3302 break; 3303 } 3304 3305 3306 if ((flags & SI_WILDP) != 0) 3307 goto find_in_wild_ports; 3308 3309 hv = NAT_HASH_FN(dst, dport, 0xffffffff); 3310 hv = NAT_HASH_FN(src.s_addr, hv + sport, ifs->ifs_ipf_nattable_sz); 3311 nat = ifs->ifs_nat_table[1][hv]; 3312 for (; nat; nat = nat->nat_hnext[1]) { 3313 if (nat->nat_v != 4) 3314 continue; 3315 3316 if (nat->nat_ifps[0] != NULL) { 3317 if ((ifp != NULL) && (ifp != nat->nat_ifps[0])) 3318 continue; 3319 } else if (ifp != NULL) 3320 nat->nat_ifps[0] = ifp; 3321 3322 nflags = nat->nat_flags; 3323 3324 if (nat->nat_oip.s_addr == src.s_addr && 3325 nat->nat_outip.s_addr == dst && 3326 (((p == 0) && 3327 (sflags == (nat->nat_flags & IPN_TCPUDPICMP))) 3328 || (p == nat->nat_p))) { 3329 switch (p) 3330 { 3331 #if 0 3332 case IPPROTO_GRE : 3333 if (nat->nat_call[1] != fin->fin_data[0]) 3334 continue; 3335 break; 3336 #endif 3337 case IPPROTO_ICMP : 3338 if ((flags & IPN_ICMPERR) != 0) { 3339 if (nat->nat_outport != sport) 3340 continue; 3341 } else { 3342 if (nat->nat_outport != dport) 3343 continue; 3344 } 3345 break; 3346 case IPPROTO_TCP : 3347 case IPPROTO_UDP : 3348 if (nat->nat_oport != sport) 3349 continue; 3350 if (nat->nat_outport != dport) 3351 continue; 3352 break; 3353 default : 3354 break; 3355 } 3356 3357 ipn = nat->nat_ptr; 3358 if ((ipn != NULL) && (nat->nat_aps != NULL)) 3359 if (appr_match(fin, nat) != 0) 3360 continue; 3361 return nat; 3362 } 3363 } 3364 3365 /* 3366 * So if we didn't find it but there are wildcard members in the hash 3367 * table, go back and look for them. We do this search and update here 3368 * because it is modifying the NAT table and we want to do this only 3369 * for the first packet that matches. The exception, of course, is 3370 * for "dummy" (FI_IGNORE) lookups. 3371 */ 3372 find_in_wild_ports: 3373 if (!(flags & NAT_TCPUDP) || !(flags & NAT_SEARCH)) 3374 return NULL; 3375 if (ifs->ifs_nat_stats.ns_wilds == 0) 3376 return NULL; 3377 3378 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 3379 3380 hv = NAT_HASH_FN(dst, 0, 0xffffffff); 3381 hv = NAT_HASH_FN(src.s_addr, hv, ifs->ifs_ipf_nattable_sz); 3382 3383 WRITE_ENTER(&ifs->ifs_ipf_nat); 3384 3385 nat = ifs->ifs_nat_table[1][hv]; 3386 for (; nat; nat = nat->nat_hnext[1]) { 3387 if (nat->nat_v != 4) 3388 continue; 3389 3390 if (nat->nat_ifps[0] != NULL) { 3391 if ((ifp != NULL) && (ifp != nat->nat_ifps[0])) 3392 continue; 3393 } else if (ifp != NULL) 3394 nat->nat_ifps[0] = ifp; 3395 3396 if (nat->nat_p != fin->fin_p) 3397 continue; 3398 if (nat->nat_oip.s_addr != src.s_addr || 3399 nat->nat_outip.s_addr != dst) 3400 continue; 3401 3402 nflags = nat->nat_flags; 3403 if (!(nflags & (NAT_TCPUDP|SI_WILDP))) 3404 continue; 3405 3406 if (nat_wildok(nat, (int)sport, (int)dport, nflags, 3407 NAT_INBOUND) == 1) { 3408 if ((fin->fin_flx & FI_IGNORE) != 0) 3409 break; 3410 if ((nflags & SI_CLONE) != 0) { 3411 nat = fr_natclone(fin, nat); 3412 if (nat == NULL) 3413 break; 3414 } else { 3415 MUTEX_ENTER(&ifs->ifs_ipf_nat_new); 3416 ifs->ifs_nat_stats.ns_wilds--; 3417 MUTEX_EXIT(&ifs->ifs_ipf_nat_new); 3418 } 3419 nat->nat_oport = sport; 3420 nat->nat_outport = dport; 3421 nat->nat_flags &= ~(SI_W_DPORT|SI_W_SPORT); 3422 nat_tabmove(nat, ifs); 3423 break; 3424 } 3425 } 3426 3427 MUTEX_DOWNGRADE(&ifs->ifs_ipf_nat); 3428 3429 return nat; 3430 } 3431 3432 3433 /* ------------------------------------------------------------------------ */ 3434 /* Function: nat_tabmove */ 3435 /* Returns: Nil */ 3436 /* Parameters: nat(I) - pointer to NAT structure */ 3437 /* Write Lock: ipf_nat */ 3438 /* */ 3439 /* This function is only called for TCP/UDP NAT table entries where the */ 3440 /* original was placed in the table without hashing on the ports and we now */ 3441 /* want to include hashing on port numbers. */ 3442 /* ------------------------------------------------------------------------ */ 3443 static void nat_tabmove(nat, ifs) 3444 nat_t *nat; 3445 ipf_stack_t *ifs; 3446 { 3447 nat_t **natp; 3448 u_int hv; 3449 3450 if (nat->nat_flags & SI_CLONE) 3451 return; 3452 3453 /* 3454 * Remove the NAT entry from the old location 3455 */ 3456 if (nat->nat_hnext[0]) 3457 nat->nat_hnext[0]->nat_phnext[0] = nat->nat_phnext[0]; 3458 *nat->nat_phnext[0] = nat->nat_hnext[0]; 3459 ifs->ifs_nat_stats.ns_bucketlen[0][nat->nat_hv[0]]--; 3460 3461 if (nat->nat_hnext[1]) 3462 nat->nat_hnext[1]->nat_phnext[1] = nat->nat_phnext[1]; 3463 *nat->nat_phnext[1] = nat->nat_hnext[1]; 3464 ifs->ifs_nat_stats.ns_bucketlen[1][nat->nat_hv[1]]--; 3465 3466 /* 3467 * Add into the NAT table in the new position 3468 */ 3469 hv = NAT_HASH_FN(nat->nat_inip.s_addr, nat->nat_inport, 0xffffffff); 3470 hv = NAT_HASH_FN(nat->nat_oip.s_addr, hv + nat->nat_oport, 3471 ifs->ifs_ipf_nattable_sz); 3472 nat->nat_hv[0] = hv; 3473 natp = &ifs->ifs_nat_table[0][hv]; 3474 if (*natp) 3475 (*natp)->nat_phnext[0] = &nat->nat_hnext[0]; 3476 nat->nat_phnext[0] = natp; 3477 nat->nat_hnext[0] = *natp; 3478 *natp = nat; 3479 ifs->ifs_nat_stats.ns_bucketlen[0][hv]++; 3480 3481 hv = NAT_HASH_FN(nat->nat_outip.s_addr, nat->nat_outport, 0xffffffff); 3482 hv = NAT_HASH_FN(nat->nat_oip.s_addr, hv + nat->nat_oport, 3483 ifs->ifs_ipf_nattable_sz); 3484 nat->nat_hv[1] = hv; 3485 natp = &ifs->ifs_nat_table[1][hv]; 3486 if (*natp) 3487 (*natp)->nat_phnext[1] = &nat->nat_hnext[1]; 3488 nat->nat_phnext[1] = natp; 3489 nat->nat_hnext[1] = *natp; 3490 *natp = nat; 3491 ifs->ifs_nat_stats.ns_bucketlen[1][hv]++; 3492 } 3493 3494 3495 /* ------------------------------------------------------------------------ */ 3496 /* Function: nat_outlookup */ 3497 /* Returns: nat_t* - NULL == no match, */ 3498 /* else pointer to matching NAT entry */ 3499 /* Parameters: fin(I) - pointer to packet information */ 3500 /* flags(I) - NAT flags for this packet */ 3501 /* p(I) - protocol for this packet */ 3502 /* src(I) - source IP address */ 3503 /* dst(I) - destination IP address */ 3504 /* rw(I) - 1 == write lock on ipf_nat held, 0 == read lock. */ 3505 /* */ 3506 /* Lookup a nat entry based on the source 'real' ip address/port and */ 3507 /* destination address/port. We use this lookup when sending a packet out, */ 3508 /* we're looking for a table entry, based on the source address. */ 3509 /* */ 3510 /* NOTE: THE PACKET BEING CHECKED (IF FOUND) HAS A MAPPING ALREADY. */ 3511 /* */ 3512 /* NOTE: IT IS ASSUMED THAT ipf_nat IS ONLY HELD WITH A READ LOCK WHEN */ 3513 /* THIS FUNCTION IS CALLED WITH NAT_SEARCH SET IN nflags. */ 3514 /* */ 3515 /* flags -> relevant are IPN_UDP/IPN_TCP/IPN_ICMPQUERY that indicate if */ 3516 /* the packet is of said protocol */ 3517 /* ------------------------------------------------------------------------ */ 3518 nat_t *nat_outlookup(fin, flags, p, src, dst) 3519 fr_info_t *fin; 3520 u_int flags, p; 3521 struct in_addr src , dst; 3522 { 3523 u_short sport, dport; 3524 u_int sflags; 3525 ipnat_t *ipn; 3526 u_32_t srcip; 3527 nat_t *nat; 3528 int nflags; 3529 void *ifp; 3530 u_int hv; 3531 ipf_stack_t *ifs = fin->fin_ifs; 3532 3533 ifp = fin->fin_ifp; 3534 3535 srcip = src.s_addr; 3536 sflags = flags & IPN_TCPUDPICMP; 3537 sport = 0; 3538 dport = 0; 3539 3540 switch (p) 3541 { 3542 case IPPROTO_TCP : 3543 case IPPROTO_UDP : 3544 sport = htons(fin->fin_data[0]); 3545 dport = htons(fin->fin_data[1]); 3546 break; 3547 case IPPROTO_ICMP : 3548 if (flags & IPN_ICMPERR) 3549 sport = fin->fin_data[1]; 3550 else 3551 dport = fin->fin_data[1]; 3552 break; 3553 default : 3554 break; 3555 } 3556 3557 if ((flags & SI_WILDP) != 0) 3558 goto find_out_wild_ports; 3559 3560 hv = NAT_HASH_FN(srcip, sport, 0xffffffff); 3561 hv = NAT_HASH_FN(dst.s_addr, hv + dport, ifs->ifs_ipf_nattable_sz); 3562 nat = ifs->ifs_nat_table[0][hv]; 3563 for (; nat; nat = nat->nat_hnext[0]) { 3564 if (nat->nat_v != 4) 3565 continue; 3566 3567 if (nat->nat_ifps[1] != NULL) { 3568 if ((ifp != NULL) && (ifp != nat->nat_ifps[1])) 3569 continue; 3570 } else if (ifp != NULL) 3571 nat->nat_ifps[1] = ifp; 3572 3573 nflags = nat->nat_flags; 3574 3575 if (nat->nat_inip.s_addr == srcip && 3576 nat->nat_oip.s_addr == dst.s_addr && 3577 (((p == 0) && (sflags == (nflags & NAT_TCPUDPICMP))) 3578 || (p == nat->nat_p))) { 3579 switch (p) 3580 { 3581 #if 0 3582 case IPPROTO_GRE : 3583 if (nat->nat_call[1] != fin->fin_data[0]) 3584 continue; 3585 break; 3586 #endif 3587 case IPPROTO_TCP : 3588 case IPPROTO_UDP : 3589 if (nat->nat_oport != dport) 3590 continue; 3591 if (nat->nat_inport != sport) 3592 continue; 3593 break; 3594 default : 3595 break; 3596 } 3597 3598 ipn = nat->nat_ptr; 3599 if ((ipn != NULL) && (nat->nat_aps != NULL)) 3600 if (appr_match(fin, nat) != 0) 3601 continue; 3602 return nat; 3603 } 3604 } 3605 3606 /* 3607 * So if we didn't find it but there are wildcard members in the hash 3608 * table, go back and look for them. We do this search and update here 3609 * because it is modifying the NAT table and we want to do this only 3610 * for the first packet that matches. The exception, of course, is 3611 * for "dummy" (FI_IGNORE) lookups. 3612 */ 3613 find_out_wild_ports: 3614 if (!(flags & NAT_TCPUDP) || !(flags & NAT_SEARCH)) 3615 return NULL; 3616 if (ifs->ifs_nat_stats.ns_wilds == 0) 3617 return NULL; 3618 3619 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 3620 3621 hv = NAT_HASH_FN(srcip, 0, 0xffffffff); 3622 hv = NAT_HASH_FN(dst.s_addr, hv, ifs->ifs_ipf_nattable_sz); 3623 3624 WRITE_ENTER(&ifs->ifs_ipf_nat); 3625 3626 nat = ifs->ifs_nat_table[0][hv]; 3627 for (; nat; nat = nat->nat_hnext[0]) { 3628 if (nat->nat_v != 4) 3629 continue; 3630 3631 if (nat->nat_ifps[1] != NULL) { 3632 if ((ifp != NULL) && (ifp != nat->nat_ifps[1])) 3633 continue; 3634 } else if (ifp != NULL) 3635 nat->nat_ifps[1] = ifp; 3636 3637 if (nat->nat_p != fin->fin_p) 3638 continue; 3639 if ((nat->nat_inip.s_addr != srcip) || 3640 (nat->nat_oip.s_addr != dst.s_addr)) 3641 continue; 3642 3643 nflags = nat->nat_flags; 3644 if (!(nflags & (NAT_TCPUDP|SI_WILDP))) 3645 continue; 3646 3647 if (nat_wildok(nat, (int)sport, (int)dport, nflags, 3648 NAT_OUTBOUND) == 1) { 3649 if ((fin->fin_flx & FI_IGNORE) != 0) 3650 break; 3651 if ((nflags & SI_CLONE) != 0) { 3652 nat = fr_natclone(fin, nat); 3653 if (nat == NULL) 3654 break; 3655 } else { 3656 MUTEX_ENTER(&ifs->ifs_ipf_nat_new); 3657 ifs->ifs_nat_stats.ns_wilds--; 3658 MUTEX_EXIT(&ifs->ifs_ipf_nat_new); 3659 } 3660 nat->nat_inport = sport; 3661 nat->nat_oport = dport; 3662 if (nat->nat_outport == 0) 3663 nat->nat_outport = sport; 3664 nat->nat_flags &= ~(SI_W_DPORT|SI_W_SPORT); 3665 nat_tabmove(nat, ifs); 3666 break; 3667 } 3668 } 3669 3670 MUTEX_DOWNGRADE(&ifs->ifs_ipf_nat); 3671 3672 return nat; 3673 } 3674 3675 3676 /* ------------------------------------------------------------------------ */ 3677 /* Function: nat_lookupredir */ 3678 /* Returns: nat_t* - NULL == no match, */ 3679 /* else pointer to matching NAT entry */ 3680 /* Parameters: np(I) - pointer to description of packet to find NAT table */ 3681 /* entry for. */ 3682 /* */ 3683 /* Lookup the NAT tables to search for a matching redirect */ 3684 /* ------------------------------------------------------------------------ */ 3685 nat_t *nat_lookupredir(np, ifs) 3686 natlookup_t *np; 3687 ipf_stack_t *ifs; 3688 { 3689 fr_info_t fi; 3690 nat_t *nat; 3691 3692 bzero((char *)&fi, sizeof(fi)); 3693 if (np->nl_flags & IPN_IN) { 3694 fi.fin_data[0] = ntohs(np->nl_realport); 3695 fi.fin_data[1] = ntohs(np->nl_outport); 3696 } else { 3697 fi.fin_data[0] = ntohs(np->nl_inport); 3698 fi.fin_data[1] = ntohs(np->nl_outport); 3699 } 3700 if (np->nl_flags & IPN_TCP) 3701 fi.fin_p = IPPROTO_TCP; 3702 else if (np->nl_flags & IPN_UDP) 3703 fi.fin_p = IPPROTO_UDP; 3704 else if (np->nl_flags & (IPN_ICMPERR|IPN_ICMPQUERY)) 3705 fi.fin_p = IPPROTO_ICMP; 3706 3707 fi.fin_ifs = ifs; 3708 /* 3709 * We can do two sorts of lookups: 3710 * - IPN_IN: we have the `real' and `out' address, look for `in'. 3711 * - default: we have the `in' and `out' address, look for `real'. 3712 */ 3713 if (np->nl_flags & IPN_IN) { 3714 if ((nat = nat_inlookup(&fi, np->nl_flags, fi.fin_p, 3715 np->nl_realip, np->nl_outip))) { 3716 np->nl_inip = nat->nat_inip; 3717 np->nl_inport = nat->nat_inport; 3718 } 3719 } else { 3720 /* 3721 * If nl_inip is non null, this is a lookup based on the real 3722 * ip address. Else, we use the fake. 3723 */ 3724 if ((nat = nat_outlookup(&fi, np->nl_flags, fi.fin_p, 3725 np->nl_inip, np->nl_outip))) { 3726 3727 if ((np->nl_flags & IPN_FINDFORWARD) != 0) { 3728 fr_info_t fin; 3729 bzero((char *)&fin, sizeof(fin)); 3730 fin.fin_p = nat->nat_p; 3731 fin.fin_data[0] = ntohs(nat->nat_outport); 3732 fin.fin_data[1] = ntohs(nat->nat_oport); 3733 fin.fin_ifs = ifs; 3734 if (nat_inlookup(&fin, np->nl_flags, fin.fin_p, 3735 nat->nat_outip, 3736 nat->nat_oip) != NULL) { 3737 np->nl_flags &= ~IPN_FINDFORWARD; 3738 } 3739 } 3740 3741 np->nl_realip = nat->nat_outip; 3742 np->nl_realport = nat->nat_outport; 3743 } 3744 } 3745 3746 return nat; 3747 } 3748 3749 3750 /* ------------------------------------------------------------------------ */ 3751 /* Function: nat_match */ 3752 /* Returns: int - 0 == no match, 1 == match */ 3753 /* Parameters: fin(I) - pointer to packet information */ 3754 /* np(I) - pointer to NAT rule */ 3755 /* */ 3756 /* Pull the matching of a packet against a NAT rule out of that complex */ 3757 /* loop inside fr_checknatin() and lay it out properly in its own function. */ 3758 /* ------------------------------------------------------------------------ */ 3759 static int nat_match(fin, np) 3760 fr_info_t *fin; 3761 ipnat_t *np; 3762 { 3763 frtuc_t *ft; 3764 3765 if (fin->fin_v != 4) 3766 return 0; 3767 3768 if (np->in_p && fin->fin_p != np->in_p) 3769 return 0; 3770 3771 if (fin->fin_out) { 3772 if (!(np->in_redir & (NAT_MAP|NAT_MAPBLK))) 3773 return 0; 3774 if (((fin->fin_fi.fi_saddr & np->in_inmsk) != np->in_inip) 3775 ^ ((np->in_flags & IPN_NOTSRC) != 0)) 3776 return 0; 3777 if (((fin->fin_fi.fi_daddr & np->in_srcmsk) != np->in_srcip) 3778 ^ ((np->in_flags & IPN_NOTDST) != 0)) 3779 return 0; 3780 } else { 3781 if (!(np->in_redir & NAT_REDIRECT)) 3782 return 0; 3783 if (((fin->fin_fi.fi_saddr & np->in_srcmsk) != np->in_srcip) 3784 ^ ((np->in_flags & IPN_NOTSRC) != 0)) 3785 return 0; 3786 if (((fin->fin_fi.fi_daddr & np->in_outmsk) != np->in_outip) 3787 ^ ((np->in_flags & IPN_NOTDST) != 0)) 3788 return 0; 3789 } 3790 3791 ft = &np->in_tuc; 3792 if (!(fin->fin_flx & FI_TCPUDP) || 3793 (fin->fin_flx & (FI_SHORT|FI_FRAGBODY))) { 3794 if (ft->ftu_scmp || ft->ftu_dcmp) 3795 return 0; 3796 return 1; 3797 } 3798 3799 return fr_tcpudpchk(fin, ft); 3800 } 3801 3802 3803 /* ------------------------------------------------------------------------ */ 3804 /* Function: nat_update */ 3805 /* Returns: Nil */ 3806 /* Parameters: fin(I) - pointer to packet information */ 3807 /* nat(I) - pointer to NAT structure */ 3808 /* np(I) - pointer to NAT rule */ 3809 /* Locks: nat_lock */ 3810 /* */ 3811 /* Updates the lifetime of a NAT table entry for non-TCP packets. Must be */ 3812 /* called with fin_rev updated - i.e. after calling nat_proto(). */ 3813 /* ------------------------------------------------------------------------ */ 3814 void nat_update(fin, nat, np) 3815 fr_info_t *fin; 3816 nat_t *nat; 3817 ipnat_t *np; 3818 { 3819 ipftq_t *ifq, *ifq2; 3820 ipftqent_t *tqe; 3821 ipf_stack_t *ifs = fin->fin_ifs; 3822 3823 tqe = &nat->nat_tqe; 3824 ifq = tqe->tqe_ifq; 3825 3826 /* 3827 * We allow over-riding of NAT timeouts from NAT rules, even for 3828 * TCP, however, if it is TCP and there is no rule timeout set, 3829 * then do not update the timeout here. 3830 */ 3831 if (np != NULL) 3832 ifq2 = np->in_tqehead[fin->fin_rev]; 3833 else 3834 ifq2 = NULL; 3835 3836 if (nat->nat_p == IPPROTO_TCP && ifq2 == NULL) { 3837 (void) fr_tcp_age(&nat->nat_tqe, fin, ifs->ifs_nat_tqb, 0); 3838 } else { 3839 if (ifq2 == NULL) { 3840 if (nat->nat_p == IPPROTO_UDP) 3841 ifq2 = &ifs->ifs_nat_udptq; 3842 else if (nat->nat_p == IPPROTO_ICMP) 3843 ifq2 = &ifs->ifs_nat_icmptq; 3844 else 3845 ifq2 = &ifs->ifs_nat_iptq; 3846 } 3847 3848 fr_movequeue(tqe, ifq, ifq2, ifs); 3849 } 3850 } 3851 3852 3853 /* ------------------------------------------------------------------------ */ 3854 /* Function: fr_checknatout */ 3855 /* Returns: int - -1 == packet failed NAT checks so block it, */ 3856 /* 0 == no packet translation occurred, */ 3857 /* 1 == packet was successfully translated. */ 3858 /* Parameters: fin(I) - pointer to packet information */ 3859 /* passp(I) - pointer to filtering result flags */ 3860 /* */ 3861 /* Check to see if an outcoming packet should be changed. ICMP packets are */ 3862 /* first checked to see if they match an existing entry (if an error), */ 3863 /* otherwise a search of the current NAT table is made. If neither results */ 3864 /* in a match then a search for a matching NAT rule is made. Create a new */ 3865 /* NAT entry if a we matched a NAT rule. Lastly, actually change the */ 3866 /* packet header(s) as required. */ 3867 /* ------------------------------------------------------------------------ */ 3868 int fr_checknatout(fin, passp) 3869 fr_info_t *fin; 3870 u_32_t *passp; 3871 { 3872 ipnat_t *np = NULL, *npnext; 3873 struct ifnet *ifp, *sifp; 3874 icmphdr_t *icmp = NULL; 3875 tcphdr_t *tcp = NULL; 3876 int rval, natfailed; 3877 u_int nflags = 0; 3878 u_32_t ipa, iph; 3879 int natadd = 1; 3880 frentry_t *fr; 3881 nat_t *nat; 3882 ipf_stack_t *ifs = fin->fin_ifs; 3883 3884 if (ifs->ifs_fr_nat_lock != 0) 3885 return 0; 3886 if (ifs->ifs_nat_stats.ns_rules == 0 && ifs->ifs_nat_instances == NULL) 3887 return 0; 3888 3889 natfailed = 0; 3890 fr = fin->fin_fr; 3891 sifp = fin->fin_ifp; 3892 if ((fr != NULL) && !(fr->fr_flags & FR_DUP) && 3893 fr->fr_tifs[fin->fin_rev].fd_ifp && 3894 fr->fr_tifs[fin->fin_rev].fd_ifp != (void *)-1) 3895 fin->fin_ifp = fr->fr_tifs[fin->fin_rev].fd_ifp; 3896 ifp = fin->fin_ifp; 3897 3898 if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) { 3899 switch (fin->fin_p) 3900 { 3901 case IPPROTO_TCP : 3902 nflags = IPN_TCP; 3903 break; 3904 case IPPROTO_UDP : 3905 nflags = IPN_UDP; 3906 break; 3907 case IPPROTO_ICMP : 3908 icmp = fin->fin_dp; 3909 3910 /* 3911 * This is an incoming packet, so the destination is 3912 * the icmp_id and the source port equals 0 3913 */ 3914 if (nat_icmpquerytype4(icmp->icmp_type)) 3915 nflags = IPN_ICMPQUERY; 3916 break; 3917 default : 3918 break; 3919 } 3920 3921 if ((nflags & IPN_TCPUDP)) 3922 tcp = fin->fin_dp; 3923 } 3924 3925 ipa = fin->fin_saddr; 3926 3927 READ_ENTER(&ifs->ifs_ipf_nat); 3928 3929 if ((fin->fin_p == IPPROTO_ICMP) && !(nflags & IPN_ICMPQUERY) && 3930 (nat = nat_icmperror(fin, &nflags, NAT_OUTBOUND))) 3931 /*EMPTY*/; 3932 else if ((fin->fin_flx & FI_FRAG) && (nat = fr_nat_knownfrag(fin))) 3933 natadd = 0; 3934 else if ((nat = nat_outlookup(fin, nflags|NAT_SEARCH, (u_int)fin->fin_p, 3935 fin->fin_src, fin->fin_dst))) { 3936 nflags = nat->nat_flags; 3937 } else { 3938 u_32_t hv, msk, nmsk; 3939 3940 /* 3941 * There is no current entry in the nat table for this packet. 3942 * 3943 * If the packet is a fragment, but not the first fragment, 3944 * then don't do anything. Otherwise, if there is a matching 3945 * nat rule, try to create a new nat entry. 3946 */ 3947 if ((fin->fin_off != 0) && (fin->fin_flx & FI_TCPUDP)) 3948 goto nonatfrag; 3949 3950 msk = 0xffffffff; 3951 nmsk = ifs->ifs_nat_masks; 3952 maskloop: 3953 iph = ipa & htonl(msk); 3954 hv = NAT_HASH_FN(iph, 0, ifs->ifs_ipf_natrules_sz); 3955 for (np = ifs->ifs_nat_rules[hv]; np; np = npnext) { 3956 npnext = np->in_mnext; 3957 if ((np->in_ifps[1] && (np->in_ifps[1] != ifp))) 3958 continue; 3959 if (np->in_v != fin->fin_v) 3960 continue; 3961 if (np->in_p && (np->in_p != fin->fin_p)) 3962 continue; 3963 if ((np->in_flags & IPN_RF) && !(np->in_flags & nflags)) 3964 continue; 3965 if (np->in_flags & IPN_FILTER) { 3966 if (!nat_match(fin, np)) 3967 continue; 3968 } else if ((ipa & np->in_inmsk) != np->in_inip) 3969 continue; 3970 3971 if ((fr != NULL) && 3972 !fr_matchtag(&np->in_tag, &fr->fr_nattag)) 3973 continue; 3974 3975 if (*np->in_plabel != '\0') { 3976 if (((np->in_flags & IPN_FILTER) == 0) && 3977 (np->in_dport != tcp->th_dport)) 3978 continue; 3979 if (appr_ok(fin, tcp, np) == 0) 3980 continue; 3981 } 3982 3983 ATOMIC_INC32(np->in_use); 3984 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 3985 WRITE_ENTER(&ifs->ifs_ipf_nat); 3986 nat = nat_new(fin, np, NULL, nflags, NAT_OUTBOUND); 3987 if (nat != NULL) { 3988 np->in_use--; 3989 np->in_hits++; 3990 MUTEX_DOWNGRADE(&ifs->ifs_ipf_nat); 3991 break; 3992 } 3993 natfailed = -1; 3994 npnext = np->in_mnext; 3995 fr_ipnatderef(&np, ifs); 3996 MUTEX_DOWNGRADE(&ifs->ifs_ipf_nat); 3997 } 3998 if ((np == NULL) && (nmsk != 0)) { 3999 while (nmsk) { 4000 msk <<= 1; 4001 if (nmsk & 0x80000000) 4002 break; 4003 nmsk <<= 1; 4004 } 4005 if (nmsk != 0) { 4006 nmsk <<= 1; 4007 goto maskloop; 4008 } 4009 } 4010 } 4011 4012 nonatfrag: 4013 if (nat != NULL) { 4014 rval = fr_natout(fin, nat, natadd, nflags); 4015 if (rval == 1) { 4016 MUTEX_ENTER(&nat->nat_lock); 4017 nat_update(fin, nat, nat->nat_ptr); 4018 nat->nat_bytes[1] += fin->fin_plen; 4019 nat->nat_pkts[1]++; 4020 fin->fin_pktnum = nat->nat_pkts[1]; 4021 MUTEX_EXIT(&nat->nat_lock); 4022 } 4023 } else 4024 rval = natfailed; 4025 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 4026 4027 if (rval == -1) { 4028 if (passp != NULL) 4029 *passp = FR_BLOCK; 4030 fin->fin_flx |= FI_BADNAT; 4031 } 4032 fin->fin_ifp = sifp; 4033 return rval; 4034 } 4035 4036 /* ------------------------------------------------------------------------ */ 4037 /* Function: fr_natout */ 4038 /* Returns: int - -1 == packet failed NAT checks so block it, */ 4039 /* 1 == packet was successfully translated. */ 4040 /* Parameters: fin(I) - pointer to packet information */ 4041 /* nat(I) - pointer to NAT structure */ 4042 /* natadd(I) - flag indicating if it is safe to add frag cache */ 4043 /* nflags(I) - NAT flags set for this packet */ 4044 /* */ 4045 /* Translate a packet coming "out" on an interface. */ 4046 /* ------------------------------------------------------------------------ */ 4047 int fr_natout(fin, nat, natadd, nflags) 4048 fr_info_t *fin; 4049 nat_t *nat; 4050 int natadd; 4051 u_32_t nflags; 4052 { 4053 icmphdr_t *icmp; 4054 u_short *csump; 4055 u_32_t sumd; 4056 tcphdr_t *tcp; 4057 ipnat_t *np; 4058 int i; 4059 ipf_stack_t *ifs = fin->fin_ifs; 4060 4061 if (fin->fin_v == 6) { 4062 #ifdef USE_INET6 4063 return fr_nat6out(fin, nat, natadd, nflags); 4064 #else 4065 return NULL; 4066 #endif 4067 } 4068 4069 #if SOLARIS && defined(_KERNEL) 4070 net_handle_t net_data_p = ifs->ifs_ipf_ipv4; 4071 #endif 4072 4073 tcp = NULL; 4074 icmp = NULL; 4075 csump = NULL; 4076 np = nat->nat_ptr; 4077 4078 if ((natadd != 0) && (fin->fin_flx & FI_FRAG)) 4079 (void) fr_nat_newfrag(fin, 0, nat); 4080 4081 /* 4082 * Fix up checksums, not by recalculating them, but 4083 * simply computing adjustments. 4084 * This is only done for STREAMS based IP implementations where the 4085 * checksum has already been calculated by IP. In all other cases, 4086 * IPFilter is called before the checksum needs calculating so there 4087 * is no call to modify whatever is in the header now. 4088 */ 4089 ASSERT(fin->fin_m != NULL); 4090 if (fin->fin_v == 4 && !NET_IS_HCK_L3_FULL(net_data_p, fin->fin_m)) { 4091 if (nflags == IPN_ICMPERR) { 4092 u_32_t s1, s2; 4093 4094 s1 = LONG_SUM(ntohl(fin->fin_saddr)); 4095 s2 = LONG_SUM(ntohl(nat->nat_outip.s_addr)); 4096 CALC_SUMD(s1, s2, sumd); 4097 4098 fix_outcksum(&fin->fin_ip->ip_sum, sumd); 4099 } 4100 #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) || \ 4101 defined(linux) || defined(BRIDGE_IPF) 4102 else { 4103 /* 4104 * Strictly speaking, this isn't necessary on BSD 4105 * kernels because they do checksum calculation after 4106 * this code has run BUT if ipfilter is being used 4107 * to do NAT as a bridge, that code doesn't exist. 4108 */ 4109 if (nat->nat_dir == NAT_OUTBOUND) 4110 fix_outcksum(&fin->fin_ip->ip_sum, 4111 nat->nat_ipsumd); 4112 else 4113 fix_incksum(&fin->fin_ip->ip_sum, 4114 nat->nat_ipsumd); 4115 } 4116 #endif 4117 } 4118 4119 if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) { 4120 if ((nat->nat_outport != 0) && (nflags & IPN_TCPUDP)) { 4121 tcp = fin->fin_dp; 4122 4123 tcp->th_sport = nat->nat_outport; 4124 fin->fin_data[0] = ntohs(nat->nat_outport); 4125 } 4126 4127 if ((nat->nat_outport != 0) && (nflags & IPN_ICMPQUERY)) { 4128 icmp = fin->fin_dp; 4129 icmp->icmp_id = nat->nat_outport; 4130 } 4131 4132 csump = nat_proto(fin, nat, nflags); 4133 } 4134 4135 fin->fin_ip->ip_src = nat->nat_outip; 4136 4137 /* 4138 * The above comments do not hold for layer 4 (or higher) checksums... 4139 */ 4140 if (csump != NULL && !NET_IS_HCK_L4_FULL(net_data_p, fin->fin_m)) { 4141 if (nflags & IPN_TCPUDP && 4142 NET_IS_HCK_L4_PART(net_data_p, fin->fin_m)) 4143 sumd = nat->nat_sumd[1]; 4144 else 4145 sumd = nat->nat_sumd[0]; 4146 4147 if (nat->nat_dir == NAT_OUTBOUND) 4148 fix_outcksum(csump, sumd); 4149 else 4150 fix_incksum(csump, sumd); 4151 } 4152 #ifdef IPFILTER_SYNC 4153 ipfsync_update(SMC_NAT, fin, nat->nat_sync); 4154 #endif 4155 /* ------------------------------------------------------------- */ 4156 /* A few quick notes: */ 4157 /* Following are test conditions prior to calling the */ 4158 /* appr_check routine. */ 4159 /* */ 4160 /* A NULL tcp indicates a non TCP/UDP packet. When dealing */ 4161 /* with a redirect rule, we attempt to match the packet's */ 4162 /* source port against in_dport, otherwise we'd compare the */ 4163 /* packet's destination. */ 4164 /* ------------------------------------------------------------- */ 4165 if ((np != NULL) && (np->in_apr != NULL)) { 4166 i = appr_check(fin, nat); 4167 if (i == 0) 4168 i = 1; 4169 } else 4170 i = 1; 4171 ifs->ifs_nat_stats.ns_mapped[1]++; 4172 fin->fin_flx |= FI_NATED; 4173 return i; 4174 } 4175 4176 4177 /* ------------------------------------------------------------------------ */ 4178 /* Function: fr_checknatin */ 4179 /* Returns: int - -1 == packet failed NAT checks so block it, */ 4180 /* 0 == no packet translation occurred, */ 4181 /* 1 == packet was successfully translated. */ 4182 /* Parameters: fin(I) - pointer to packet information */ 4183 /* passp(I) - pointer to filtering result flags */ 4184 /* */ 4185 /* Check to see if an incoming packet should be changed. ICMP packets are */ 4186 /* first checked to see if they match an existing entry (if an error), */ 4187 /* otherwise a search of the current NAT table is made. If neither results */ 4188 /* in a match then a search for a matching NAT rule is made. Create a new */ 4189 /* NAT entry if a we matched a NAT rule. Lastly, actually change the */ 4190 /* packet header(s) as required. */ 4191 /* ------------------------------------------------------------------------ */ 4192 int fr_checknatin(fin, passp) 4193 fr_info_t *fin; 4194 u_32_t *passp; 4195 { 4196 u_int nflags, natadd; 4197 ipnat_t *np, *npnext; 4198 int rval, natfailed; 4199 struct ifnet *ifp; 4200 struct in_addr in; 4201 icmphdr_t *icmp; 4202 tcphdr_t *tcp; 4203 u_short dport; 4204 nat_t *nat; 4205 u_32_t iph; 4206 ipf_stack_t *ifs = fin->fin_ifs; 4207 4208 if (ifs->ifs_fr_nat_lock != 0) 4209 return 0; 4210 if (ifs->ifs_nat_stats.ns_rules == 0 && ifs->ifs_nat_instances == NULL) 4211 return 0; 4212 4213 tcp = NULL; 4214 icmp = NULL; 4215 dport = 0; 4216 natadd = 1; 4217 nflags = 0; 4218 natfailed = 0; 4219 ifp = fin->fin_ifp; 4220 4221 if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) { 4222 switch (fin->fin_p) 4223 { 4224 case IPPROTO_TCP : 4225 nflags = IPN_TCP; 4226 break; 4227 case IPPROTO_UDP : 4228 nflags = IPN_UDP; 4229 break; 4230 case IPPROTO_ICMP : 4231 icmp = fin->fin_dp; 4232 4233 /* 4234 * This is an incoming packet, so the destination is 4235 * the icmp_id and the source port equals 0 4236 */ 4237 if (nat_icmpquerytype4(icmp->icmp_type)) { 4238 nflags = IPN_ICMPQUERY; 4239 dport = icmp->icmp_id; 4240 } break; 4241 default : 4242 break; 4243 } 4244 4245 if ((nflags & IPN_TCPUDP)) { 4246 tcp = fin->fin_dp; 4247 dport = tcp->th_dport; 4248 } 4249 } 4250 4251 in = fin->fin_dst; 4252 4253 READ_ENTER(&ifs->ifs_ipf_nat); 4254 4255 if ((fin->fin_p == IPPROTO_ICMP) && !(nflags & IPN_ICMPQUERY) && 4256 (nat = nat_icmperror(fin, &nflags, NAT_INBOUND))) 4257 /*EMPTY*/; 4258 else if ((fin->fin_flx & FI_FRAG) && (nat = fr_nat_knownfrag(fin))) 4259 natadd = 0; 4260 else if ((nat = nat_inlookup(fin, nflags|NAT_SEARCH, (u_int)fin->fin_p, 4261 fin->fin_src, in))) { 4262 nflags = nat->nat_flags; 4263 } else { 4264 u_32_t hv, msk, rmsk; 4265 4266 /* 4267 * There is no current entry in the nat table for this packet. 4268 * 4269 * If the packet is a fragment, but not the first fragment, 4270 * then don't do anything. Otherwise, if there is a matching 4271 * nat rule, try to create a new nat entry. 4272 */ 4273 if ((fin->fin_off != 0) && (fin->fin_flx & FI_TCPUDP)) 4274 goto nonatfrag; 4275 4276 rmsk = ifs->ifs_rdr_masks; 4277 msk = 0xffffffff; 4278 maskloop: 4279 iph = in.s_addr & htonl(msk); 4280 hv = NAT_HASH_FN(iph, 0, ifs->ifs_ipf_rdrrules_sz); 4281 for (np = ifs->ifs_rdr_rules[hv]; np; np = npnext) { 4282 npnext = np->in_rnext; 4283 if (np->in_ifps[0] && (np->in_ifps[0] != ifp)) 4284 continue; 4285 if (np->in_v != fin->fin_v) 4286 continue; 4287 if (np->in_p && (np->in_p != fin->fin_p)) 4288 continue; 4289 if ((np->in_flags & IPN_RF) && !(np->in_flags & nflags)) 4290 continue; 4291 if (np->in_flags & IPN_FILTER) { 4292 if (!nat_match(fin, np)) 4293 continue; 4294 } else { 4295 if ((in.s_addr & np->in_outmsk) != np->in_outip) 4296 continue; 4297 if (np->in_pmin && 4298 ((ntohs(np->in_pmax) < ntohs(dport)) || 4299 (ntohs(dport) < ntohs(np->in_pmin)))) 4300 continue; 4301 } 4302 4303 if (*np->in_plabel != '\0') { 4304 if (!appr_ok(fin, tcp, np)) { 4305 continue; 4306 } 4307 } 4308 4309 ATOMIC_INC32(np->in_use); 4310 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 4311 WRITE_ENTER(&ifs->ifs_ipf_nat); 4312 nat = nat_new(fin, np, NULL, nflags, NAT_INBOUND); 4313 if (nat != NULL) { 4314 np->in_use--; 4315 np->in_hits++; 4316 MUTEX_DOWNGRADE(&ifs->ifs_ipf_nat); 4317 break; 4318 } 4319 natfailed = -1; 4320 npnext = np->in_rnext; 4321 fr_ipnatderef(&np, ifs); 4322 MUTEX_DOWNGRADE(&ifs->ifs_ipf_nat); 4323 } 4324 4325 if ((np == NULL) && (rmsk != 0)) { 4326 while (rmsk) { 4327 msk <<= 1; 4328 if (rmsk & 0x80000000) 4329 break; 4330 rmsk <<= 1; 4331 } 4332 if (rmsk != 0) { 4333 rmsk <<= 1; 4334 goto maskloop; 4335 } 4336 } 4337 } 4338 4339 nonatfrag: 4340 if (nat != NULL) { 4341 rval = fr_natin(fin, nat, natadd, nflags); 4342 if (rval == 1) { 4343 MUTEX_ENTER(&nat->nat_lock); 4344 nat_update(fin, nat, nat->nat_ptr); 4345 nat->nat_bytes[0] += fin->fin_plen; 4346 nat->nat_pkts[0]++; 4347 fin->fin_pktnum = nat->nat_pkts[0]; 4348 MUTEX_EXIT(&nat->nat_lock); 4349 } 4350 } else 4351 rval = natfailed; 4352 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 4353 4354 if (rval == -1) { 4355 if (passp != NULL) 4356 *passp = FR_BLOCK; 4357 fin->fin_flx |= FI_BADNAT; 4358 } 4359 return rval; 4360 } 4361 4362 4363 /* ------------------------------------------------------------------------ */ 4364 /* Function: fr_natin */ 4365 /* Returns: int - -1 == packet failed NAT checks so block it, */ 4366 /* 1 == packet was successfully translated. */ 4367 /* Parameters: fin(I) - pointer to packet information */ 4368 /* nat(I) - pointer to NAT structure */ 4369 /* natadd(I) - flag indicating if it is safe to add frag cache */ 4370 /* nflags(I) - NAT flags set for this packet */ 4371 /* Locks Held: ipf_nat (READ) */ 4372 /* */ 4373 /* Translate a packet coming "in" on an interface. */ 4374 /* ------------------------------------------------------------------------ */ 4375 int fr_natin(fin, nat, natadd, nflags) 4376 fr_info_t *fin; 4377 nat_t *nat; 4378 int natadd; 4379 u_32_t nflags; 4380 { 4381 icmphdr_t *icmp; 4382 u_short *csump; 4383 tcphdr_t *tcp; 4384 ipnat_t *np; 4385 int i; 4386 ipf_stack_t *ifs = fin->fin_ifs; 4387 4388 if (fin->fin_v == 6) { 4389 #ifdef USE_INET6 4390 return fr_nat6in(fin, nat, natadd, nflags); 4391 #else 4392 return NULL; 4393 #endif 4394 } 4395 4396 #if SOLARIS && defined(_KERNEL) 4397 net_handle_t net_data_p = ifs->ifs_ipf_ipv4; 4398 #endif 4399 4400 tcp = NULL; 4401 csump = NULL; 4402 np = nat->nat_ptr; 4403 fin->fin_fr = nat->nat_fr; 4404 4405 if ((natadd != 0) && (fin->fin_flx & FI_FRAG)) 4406 (void) fr_nat_newfrag(fin, 0, nat); 4407 4408 if (np != NULL) { 4409 4410 /* ------------------------------------------------------------- */ 4411 /* A few quick notes: */ 4412 /* Following are test conditions prior to calling the */ 4413 /* appr_check routine. */ 4414 /* */ 4415 /* A NULL tcp indicates a non TCP/UDP packet. When dealing */ 4416 /* with a map rule, we attempt to match the packet's */ 4417 /* source port against in_dport, otherwise we'd compare the */ 4418 /* packet's destination. */ 4419 /* ------------------------------------------------------------- */ 4420 if (np->in_apr != NULL) { 4421 i = appr_check(fin, nat); 4422 if (i == -1) { 4423 return -1; 4424 } 4425 } 4426 } 4427 4428 #ifdef IPFILTER_SYNC 4429 ipfsync_update(SMC_NAT, fin, nat->nat_sync); 4430 #endif 4431 4432 fin->fin_ip->ip_dst = nat->nat_inip; 4433 fin->fin_fi.fi_daddr = nat->nat_inip.s_addr; 4434 if (nflags & IPN_TCPUDP) 4435 tcp = fin->fin_dp; 4436 4437 /* 4438 * Fix up checksums, not by recalculating them, but 4439 * simply computing adjustments. 4440 * Why only do this for some platforms on inbound packets ? 4441 * Because for those that it is done, IP processing is yet to happen 4442 * and so the IPv4 header checksum has not yet been evaluated. 4443 * Perhaps it should always be done for the benefit of things like 4444 * fast forwarding (so that it doesn't need to be recomputed) but with 4445 * header checksum offloading, perhaps it is a moot point. 4446 */ 4447 #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) || \ 4448 defined(__osf__) || defined(linux) 4449 if (nat->nat_dir == NAT_OUTBOUND) 4450 fix_incksum(&fin->fin_ip->ip_sum, nat->nat_ipsumd); 4451 else 4452 fix_outcksum(&fin->fin_ip->ip_sum, nat->nat_ipsumd); 4453 #endif 4454 4455 if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) { 4456 if ((nat->nat_inport != 0) && (nflags & IPN_TCPUDP)) { 4457 tcp->th_dport = nat->nat_inport; 4458 fin->fin_data[1] = ntohs(nat->nat_inport); 4459 } 4460 4461 4462 if ((nat->nat_inport != 0) && (nflags & IPN_ICMPQUERY)) { 4463 icmp = fin->fin_dp; 4464 4465 icmp->icmp_id = nat->nat_inport; 4466 } 4467 4468 csump = nat_proto(fin, nat, nflags); 4469 } 4470 4471 /* 4472 * In case they are being forwarded, inbound packets always need to have 4473 * their checksum adjusted even if hardware checksum validation said OK. 4474 */ 4475 if (csump != NULL) { 4476 if (nat->nat_dir == NAT_OUTBOUND) 4477 fix_incksum(csump, nat->nat_sumd[0]); 4478 else 4479 fix_outcksum(csump, nat->nat_sumd[0]); 4480 } 4481 4482 #if SOLARIS && defined(_KERNEL) 4483 if (nflags & IPN_TCPUDP && 4484 NET_IS_HCK_L4_PART(net_data_p, fin->fin_m)) { 4485 /* 4486 * Need to adjust the partial checksum result stored in 4487 * db_cksum16, which will be used for validation in IP. 4488 * See IP_CKSUM_RECV(). 4489 * Adjustment data should be the inverse of the IP address 4490 * changes, because db_cksum16 is supposed to be the complement 4491 * of the pesudo header. 4492 */ 4493 csump = &fin->fin_m->b_datap->db_cksum16; 4494 if (nat->nat_dir == NAT_OUTBOUND) 4495 fix_outcksum(csump, nat->nat_sumd[1]); 4496 else 4497 fix_incksum(csump, nat->nat_sumd[1]); 4498 } 4499 #endif 4500 4501 ifs->ifs_nat_stats.ns_mapped[0]++; 4502 fin->fin_flx |= FI_NATED; 4503 if (np != NULL && np->in_tag.ipt_num[0] != 0) 4504 fin->fin_nattag = &np->in_tag; 4505 return 1; 4506 } 4507 4508 4509 /* ------------------------------------------------------------------------ */ 4510 /* Function: nat_proto */ 4511 /* Returns: u_short* - pointer to transport header checksum to update, */ 4512 /* NULL if the transport protocol is not recognised */ 4513 /* as needing a checksum update. */ 4514 /* Parameters: fin(I) - pointer to packet information */ 4515 /* nat(I) - pointer to NAT structure */ 4516 /* nflags(I) - NAT flags set for this packet */ 4517 /* */ 4518 /* Return the pointer to the checksum field for each protocol so understood.*/ 4519 /* If support for making other changes to a protocol header is required, */ 4520 /* that is not strictly 'address' translation, such as clamping the MSS in */ 4521 /* TCP down to a specific value, then do it from here. */ 4522 /* ------------------------------------------------------------------------ */ 4523 u_short *nat_proto(fin, nat, nflags) 4524 fr_info_t *fin; 4525 nat_t *nat; 4526 u_int nflags; 4527 { 4528 icmphdr_t *icmp; 4529 struct icmp6_hdr *icmp6; 4530 u_short *csump; 4531 tcphdr_t *tcp; 4532 udphdr_t *udp; 4533 4534 csump = NULL; 4535 if (fin->fin_out == 0) { 4536 fin->fin_rev = (nat->nat_dir == NAT_OUTBOUND); 4537 } else { 4538 fin->fin_rev = (nat->nat_dir == NAT_INBOUND); 4539 } 4540 4541 switch (fin->fin_p) 4542 { 4543 case IPPROTO_TCP : 4544 tcp = fin->fin_dp; 4545 4546 csump = &tcp->th_sum; 4547 4548 /* 4549 * Do a MSS CLAMPING on a SYN packet, 4550 * only deal IPv4 for now. 4551 */ 4552 if ((nat->nat_mssclamp != 0) && (tcp->th_flags & TH_SYN) != 0) 4553 nat_mssclamp(tcp, nat->nat_mssclamp, csump); 4554 4555 break; 4556 4557 case IPPROTO_UDP : 4558 udp = fin->fin_dp; 4559 4560 if (udp->uh_sum) 4561 csump = &udp->uh_sum; 4562 break; 4563 4564 case IPPROTO_ICMP : 4565 icmp = fin->fin_dp; 4566 4567 if ((nflags & IPN_ICMPQUERY) != 0) { 4568 if (icmp->icmp_cksum != 0) 4569 csump = &icmp->icmp_cksum; 4570 } 4571 break; 4572 4573 case IPPROTO_ICMPV6 : 4574 icmp6 = fin->fin_dp; 4575 4576 if ((nflags & IPN_ICMPQUERY) != 0) { 4577 if (icmp6->icmp6_cksum != 0) 4578 csump = &icmp6->icmp6_cksum; 4579 } 4580 break; 4581 } 4582 return csump; 4583 } 4584 4585 4586 /* ------------------------------------------------------------------------ */ 4587 /* Function: fr_natunload */ 4588 /* Returns: Nil */ 4589 /* Parameters: ifs - ipf stack instance */ 4590 /* */ 4591 /* Free all memory used by NAT structures allocated at runtime. */ 4592 /* ------------------------------------------------------------------------ */ 4593 void fr_natunload(ifs) 4594 ipf_stack_t *ifs; 4595 { 4596 ipftq_t *ifq, *ifqnext; 4597 4598 (void) nat_clearlist(ifs); 4599 (void) nat_flushtable(FLUSH_TABLE_ALL, ifs); 4600 4601 /* 4602 * Proxy timeout queues are not cleaned here because although they 4603 * exist on the NAT list, appr_unload is called after fr_natunload 4604 * and the proxies actually are responsible for them being created. 4605 * Should the proxy timeouts have their own list? There's no real 4606 * justification as this is the only complication. 4607 */ 4608 for (ifq = ifs->ifs_nat_utqe; ifq != NULL; ifq = ifqnext) { 4609 ifqnext = ifq->ifq_next; 4610 if (((ifq->ifq_flags & IFQF_PROXY) == 0) && 4611 (fr_deletetimeoutqueue(ifq) == 0)) 4612 fr_freetimeoutqueue(ifq, ifs); 4613 } 4614 4615 if (ifs->ifs_nat_table[0] != NULL) { 4616 KFREES(ifs->ifs_nat_table[0], 4617 sizeof(nat_t *) * ifs->ifs_ipf_nattable_sz); 4618 ifs->ifs_nat_table[0] = NULL; 4619 } 4620 if (ifs->ifs_nat_table[1] != NULL) { 4621 KFREES(ifs->ifs_nat_table[1], 4622 sizeof(nat_t *) * ifs->ifs_ipf_nattable_sz); 4623 ifs->ifs_nat_table[1] = NULL; 4624 } 4625 if (ifs->ifs_nat_rules != NULL) { 4626 KFREES(ifs->ifs_nat_rules, 4627 sizeof(ipnat_t *) * ifs->ifs_ipf_natrules_sz); 4628 ifs->ifs_nat_rules = NULL; 4629 } 4630 if (ifs->ifs_rdr_rules != NULL) { 4631 KFREES(ifs->ifs_rdr_rules, 4632 sizeof(ipnat_t *) * ifs->ifs_ipf_rdrrules_sz); 4633 ifs->ifs_rdr_rules = NULL; 4634 } 4635 if (ifs->ifs_maptable != NULL) { 4636 KFREES(ifs->ifs_maptable, 4637 sizeof(hostmap_t *) * ifs->ifs_ipf_hostmap_sz); 4638 ifs->ifs_maptable = NULL; 4639 } 4640 if (ifs->ifs_nat_stats.ns_bucketlen[0] != NULL) { 4641 KFREES(ifs->ifs_nat_stats.ns_bucketlen[0], 4642 sizeof(u_long *) * ifs->ifs_ipf_nattable_sz); 4643 ifs->ifs_nat_stats.ns_bucketlen[0] = NULL; 4644 } 4645 if (ifs->ifs_nat_stats.ns_bucketlen[1] != NULL) { 4646 KFREES(ifs->ifs_nat_stats.ns_bucketlen[1], 4647 sizeof(u_long *) * ifs->ifs_ipf_nattable_sz); 4648 ifs->ifs_nat_stats.ns_bucketlen[1] = NULL; 4649 } 4650 4651 if (ifs->ifs_fr_nat_maxbucket_reset == 1) 4652 ifs->ifs_fr_nat_maxbucket = 0; 4653 4654 if (ifs->ifs_fr_nat_init == 1) { 4655 ifs->ifs_fr_nat_init = 0; 4656 fr_sttab_destroy(ifs->ifs_nat_tqb); 4657 4658 RW_DESTROY(&ifs->ifs_ipf_natfrag); 4659 RW_DESTROY(&ifs->ifs_ipf_nat); 4660 4661 MUTEX_DESTROY(&ifs->ifs_ipf_nat_new); 4662 MUTEX_DESTROY(&ifs->ifs_ipf_natio); 4663 4664 MUTEX_DESTROY(&ifs->ifs_nat_udptq.ifq_lock); 4665 MUTEX_DESTROY(&ifs->ifs_nat_icmptq.ifq_lock); 4666 MUTEX_DESTROY(&ifs->ifs_nat_iptq.ifq_lock); 4667 } 4668 } 4669 4670 4671 /* ------------------------------------------------------------------------ */ 4672 /* Function: fr_natexpire */ 4673 /* Returns: Nil */ 4674 /* Parameters: ifs - ipf stack instance */ 4675 /* */ 4676 /* Check all of the timeout queues for entries at the top which need to be */ 4677 /* expired. */ 4678 /* ------------------------------------------------------------------------ */ 4679 void fr_natexpire(ifs) 4680 ipf_stack_t *ifs; 4681 { 4682 ipftq_t *ifq, *ifqnext; 4683 ipftqent_t *tqe, *tqn; 4684 int i; 4685 SPL_INT(s); 4686 4687 SPL_NET(s); 4688 WRITE_ENTER(&ifs->ifs_ipf_nat); 4689 for (ifq = ifs->ifs_nat_tqb, i = 0; ifq != NULL; ifq = ifq->ifq_next) { 4690 for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); i++) { 4691 if (tqe->tqe_die > ifs->ifs_fr_ticks) 4692 break; 4693 tqn = tqe->tqe_next; 4694 (void) nat_delete(tqe->tqe_parent, NL_EXPIRE, ifs); 4695 } 4696 } 4697 4698 for (ifq = ifs->ifs_nat_utqe; ifq != NULL; ifq = ifqnext) { 4699 ifqnext = ifq->ifq_next; 4700 4701 for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); i++) { 4702 if (tqe->tqe_die > ifs->ifs_fr_ticks) 4703 break; 4704 tqn = tqe->tqe_next; 4705 (void) nat_delete(tqe->tqe_parent, NL_EXPIRE, ifs); 4706 } 4707 } 4708 4709 for (ifq = ifs->ifs_nat_utqe; ifq != NULL; ifq = ifqnext) { 4710 ifqnext = ifq->ifq_next; 4711 4712 if (((ifq->ifq_flags & IFQF_DELETE) != 0) && 4713 (ifq->ifq_ref == 0)) { 4714 fr_freetimeoutqueue(ifq, ifs); 4715 } 4716 } 4717 4718 if (ifs->ifs_nat_doflush != 0) { 4719 (void) nat_flushtable(FLUSH_TABLE_EXTRA, ifs); 4720 ifs->ifs_nat_doflush = 0; 4721 } 4722 4723 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 4724 SPL_X(s); 4725 } 4726 4727 4728 /* ------------------------------------------------------------------------ */ 4729 /* Function: fr_nataddrsync */ 4730 /* Returns: Nil */ 4731 /* Parameters: ifp(I) - pointer to network interface */ 4732 /* addr(I) - pointer to new network address */ 4733 /* */ 4734 /* Walk through all of the currently active NAT sessions, looking for those */ 4735 /* which need to have their translated address updated (where the interface */ 4736 /* matches the one passed in) and change it, recalculating the checksum sum */ 4737 /* difference too. */ 4738 /* ------------------------------------------------------------------------ */ 4739 void fr_nataddrsync(v, ifp, addr, ifs) 4740 int v; 4741 void *ifp; 4742 void *addr; 4743 ipf_stack_t *ifs; 4744 { 4745 u_32_t sum1, sum2, sumd; 4746 nat_t *nat; 4747 ipnat_t *np; 4748 SPL_INT(s); 4749 4750 if (ifs->ifs_fr_running <= 0) 4751 return; 4752 4753 SPL_NET(s); 4754 WRITE_ENTER(&ifs->ifs_ipf_nat); 4755 4756 if (ifs->ifs_fr_running <= 0) { 4757 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 4758 return; 4759 } 4760 4761 /* 4762 * Change IP addresses for NAT sessions for any protocol except TCP 4763 * since it will break the TCP connection anyway. The only rules 4764 * which will get changed are those which are "map ... -> 0/32", 4765 * where the rule specifies the address is taken from the interface. 4766 */ 4767 for (nat = ifs->ifs_nat_instances; nat; nat = nat->nat_next) { 4768 if (addr != NULL) { 4769 if (((ifp != NULL) && ifp != (nat->nat_ifps[0])) || 4770 ((nat->nat_flags & IPN_TCP) != 0)) 4771 continue; 4772 if ((np = nat->nat_ptr) == NULL) 4773 continue; 4774 if (v == 4 && np->in_v == 4) { 4775 if (np->in_nip || np->in_outmsk != 0xffffffff) 4776 continue; 4777 /* 4778 * Change the map-to address to be the same as 4779 * the new one. 4780 */ 4781 sum1 = nat->nat_outip.s_addr; 4782 nat->nat_outip = *(struct in_addr *)addr; 4783 sum2 = nat->nat_outip.s_addr; 4784 } else if (v == 6 && np->in_v == 6) { 4785 if (!IP6_ISZERO(&np->in_next6.in6) || 4786 !IP6_ISONES(&np->in_out[1].in6)) 4787 continue; 4788 /* 4789 * Change the map-to address to be the same as 4790 * the new one. 4791 */ 4792 nat->nat_outip6.in6 = *(struct in6_addr *)addr; 4793 } else 4794 continue; 4795 4796 } else if (((ifp == NULL) || (ifp == nat->nat_ifps[0])) && 4797 !(nat->nat_flags & IPN_TCP) && (np = nat->nat_ptr)) { 4798 if (np->in_v == 4 && (v == 4 || v == 0)) { 4799 struct in_addr in; 4800 if (np->in_outmsk != 0xffffffff || np->in_nip) 4801 continue; 4802 /* 4803 * Change the map-to address to be the same as 4804 * the new one. 4805 */ 4806 sum1 = nat->nat_outip.s_addr; 4807 if (fr_ifpaddr(4, FRI_NORMAL, nat->nat_ifps[0], 4808 &in, NULL, ifs) != -1) 4809 nat->nat_outip = in; 4810 sum2 = nat->nat_outip.s_addr; 4811 } else if (np->in_v == 6 && (v == 6 || v == 0)) { 4812 struct in6_addr in6; 4813 if (!IP6_ISZERO(&np->in_next6.in6) || 4814 !IP6_ISONES(&np->in_out[1].in6)) 4815 continue; 4816 /* 4817 * Change the map-to address to be the same as 4818 * the new one. 4819 */ 4820 if (fr_ifpaddr(6, FRI_NORMAL, nat->nat_ifps[0], 4821 (void *)&in6, NULL, ifs) != -1) 4822 nat->nat_outip6.in6 = in6; 4823 } else 4824 continue; 4825 } else { 4826 continue; 4827 } 4828 4829 if (sum1 == sum2) 4830 continue; 4831 /* 4832 * Readjust the checksum adjustment to take into 4833 * account the new IP#. 4834 */ 4835 CALC_SUMD(sum1, sum2, sumd); 4836 /* XXX - dont change for TCP when solaris does 4837 * hardware checksumming. 4838 */ 4839 sumd += nat->nat_sumd[0]; 4840 nat->nat_sumd[0] = (sumd & 0xffff) + (sumd >> 16); 4841 nat->nat_sumd[1] = nat->nat_sumd[0]; 4842 } 4843 4844 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 4845 SPL_X(s); 4846 } 4847 4848 4849 /* ------------------------------------------------------------------------ */ 4850 /* Function: fr_natifpsync */ 4851 /* Returns: Nil */ 4852 /* Parameters: action(I) - how we are syncing */ 4853 /* ifp(I) - pointer to network interface */ 4854 /* name(I) - name of interface to sync to */ 4855 /* */ 4856 /* This function is used to resync the mapping of interface names and their */ 4857 /* respective 'pointers'. For "action == IPFSYNC_RESYNC", resync all */ 4858 /* interfaces by doing a new lookup of name to 'pointer'. For "action == */ 4859 /* IPFSYNC_NEWIFP", treat ifp as the new pointer value associated with */ 4860 /* "name" and for "action == IPFSYNC_OLDIFP", ifp is a pointer for which */ 4861 /* there is no longer any interface associated with it. */ 4862 /* ------------------------------------------------------------------------ */ 4863 void fr_natifpsync(action, v, ifp, name, ifs) 4864 int action, v; 4865 void *ifp; 4866 char *name; 4867 ipf_stack_t *ifs; 4868 { 4869 #if defined(_KERNEL) && !defined(MENTAT) && defined(USE_SPL) 4870 int s; 4871 #endif 4872 nat_t *nat; 4873 ipnat_t *n; 4874 int nv; 4875 4876 if (ifs->ifs_fr_running <= 0) 4877 return; 4878 4879 SPL_NET(s); 4880 WRITE_ENTER(&ifs->ifs_ipf_nat); 4881 4882 if (ifs->ifs_fr_running <= 0) { 4883 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 4884 return; 4885 } 4886 4887 switch (action) 4888 { 4889 case IPFSYNC_RESYNC : 4890 for (nat = ifs->ifs_nat_instances; nat; nat = nat->nat_next) { 4891 nv = (v == 0) ? nat->nat_v : v; 4892 if (nat->nat_v != nv) 4893 continue; 4894 if ((ifp == nat->nat_ifps[0]) || 4895 (nat->nat_ifps[0] == (void *)-1)) { 4896 nat->nat_ifps[0] = 4897 fr_resolvenic(nat->nat_ifnames[0], nv, ifs); 4898 } 4899 4900 if ((ifp == nat->nat_ifps[1]) || 4901 (nat->nat_ifps[1] == (void *)-1)) { 4902 nat->nat_ifps[1] = 4903 fr_resolvenic(nat->nat_ifnames[1], nv, ifs); 4904 } 4905 } 4906 4907 for (n = ifs->ifs_nat_list; (n != NULL); n = n->in_next) { 4908 nv = (v == 0) ? (int)n->in_v : v; 4909 if ((int)n->in_v != nv) 4910 continue; 4911 if (n->in_ifps[0] == ifp || 4912 n->in_ifps[0] == (void *)-1) { 4913 n->in_ifps[0] = 4914 fr_resolvenic(n->in_ifnames[0], nv, ifs); 4915 } 4916 if (n->in_ifps[1] == ifp || 4917 n->in_ifps[1] == (void *)-1) { 4918 n->in_ifps[1] = 4919 fr_resolvenic(n->in_ifnames[1], nv, ifs); 4920 } 4921 } 4922 break; 4923 case IPFSYNC_NEWIFP : 4924 for (nat = ifs->ifs_nat_instances; nat; nat = nat->nat_next) { 4925 if (nat->nat_v != v) 4926 continue; 4927 if (!strncmp(name, nat->nat_ifnames[0], 4928 sizeof(nat->nat_ifnames[0]))) 4929 nat->nat_ifps[0] = ifp; 4930 if (!strncmp(name, nat->nat_ifnames[1], 4931 sizeof(nat->nat_ifnames[1]))) 4932 nat->nat_ifps[1] = ifp; 4933 } 4934 for (n = ifs->ifs_nat_list; (n != NULL); n = n->in_next) { 4935 if ((int)n->in_v != v) 4936 continue; 4937 if (!strncmp(name, n->in_ifnames[0], 4938 sizeof(n->in_ifnames[0]))) 4939 n->in_ifps[0] = ifp; 4940 if (!strncmp(name, n->in_ifnames[1], 4941 sizeof(n->in_ifnames[1]))) 4942 n->in_ifps[1] = ifp; 4943 } 4944 break; 4945 case IPFSYNC_OLDIFP : 4946 for (nat = ifs->ifs_nat_instances; nat; nat = nat->nat_next) { 4947 if (nat->nat_v != v) 4948 continue; 4949 if (ifp == nat->nat_ifps[0]) 4950 nat->nat_ifps[0] = (void *)-1; 4951 if (ifp == nat->nat_ifps[1]) 4952 nat->nat_ifps[1] = (void *)-1; 4953 } 4954 for (n = ifs->ifs_nat_list; (n != NULL); n = n->in_next) { 4955 if ((int)n->in_v != v) 4956 continue; 4957 if (n->in_ifps[0] == ifp) 4958 n->in_ifps[0] = (void *)-1; 4959 if (n->in_ifps[1] == ifp) 4960 n->in_ifps[1] = (void *)-1; 4961 } 4962 break; 4963 } 4964 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 4965 SPL_X(s); 4966 } 4967 4968 #if SOLARIS2 >= 10 4969 /* ------------------------------------------------------------------------ */ 4970 /* Function: fr_natifindexsync */ 4971 /* Returns: void */ 4972 /* Parameters: ifp - interface, which is being sync'd */ 4973 /* newifp - new ifindex value for interface */ 4974 /* ifs - IPF's stack */ 4975 /* */ 4976 /* Write Locks: assumes ipf_mutex is locked */ 4977 /* */ 4978 /* Updates all interface index references in NAT rules and NAT entries. */ 4979 /* the index, which is about to be updated must match ifp value. */ 4980 /* ------------------------------------------------------------------------ */ 4981 void fr_natifindexsync(ifp, newifp, ifs) 4982 void *ifp; 4983 void *newifp; 4984 ipf_stack_t *ifs; 4985 { 4986 nat_t *nat; 4987 ipnat_t *n; 4988 4989 WRITE_ENTER(&ifs->ifs_ipf_nat); 4990 4991 for (nat = ifs->ifs_nat_instances; nat != NULL; nat = nat->nat_next) { 4992 if (ifp == nat->nat_ifps[0]) 4993 nat->nat_ifps[0] = newifp; 4994 4995 if (ifp == nat->nat_ifps[1]) 4996 nat->nat_ifps[1] = newifp; 4997 } 4998 4999 for (n = ifs->ifs_nat_list; n != NULL; n = n->in_next) { 5000 if (ifp == n->in_ifps[0]) 5001 n->in_ifps[0] = newifp; 5002 5003 if (ifp == n->in_ifps[1]) 5004 n->in_ifps[1] = newifp; 5005 } 5006 5007 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 5008 } 5009 #endif 5010 5011 /* ------------------------------------------------------------------------ */ 5012 /* Function: nat_icmpquerytype4 */ 5013 /* Returns: int - 1 == success, 0 == failure */ 5014 /* Parameters: icmptype(I) - ICMP type number */ 5015 /* */ 5016 /* Tests to see if the ICMP type number passed is a query/response type or */ 5017 /* not. */ 5018 /* ------------------------------------------------------------------------ */ 5019 static INLINE int nat_icmpquerytype4(icmptype) 5020 int icmptype; 5021 { 5022 5023 /* 5024 * For the ICMP query NAT code, it is essential that both the query 5025 * and the reply match on the NAT rule. Because the NAT structure 5026 * does not keep track of the icmptype, and a single NAT structure 5027 * is used for all icmp types with the same src, dest and id, we 5028 * simply define the replies as queries as well. The funny thing is, 5029 * altough it seems silly to call a reply a query, this is exactly 5030 * as it is defined in the IPv4 specification 5031 */ 5032 5033 switch (icmptype) 5034 { 5035 5036 case ICMP_ECHOREPLY: 5037 case ICMP_ECHO: 5038 /* route aedvertisement/solliciation is currently unsupported: */ 5039 /* it would require rewriting the ICMP data section */ 5040 case ICMP_TSTAMP: 5041 case ICMP_TSTAMPREPLY: 5042 case ICMP_IREQ: 5043 case ICMP_IREQREPLY: 5044 case ICMP_MASKREQ: 5045 case ICMP_MASKREPLY: 5046 return 1; 5047 default: 5048 return 0; 5049 } 5050 } 5051 5052 5053 /* ------------------------------------------------------------------------ */ 5054 /* Function: nat_log */ 5055 /* Returns: Nil */ 5056 /* Parameters: nat(I) - pointer to NAT structure */ 5057 /* type(I) - type of log entry to create */ 5058 /* */ 5059 /* Creates a NAT log entry. */ 5060 /* ------------------------------------------------------------------------ */ 5061 void nat_log(nat, type, ifs) 5062 struct nat *nat; 5063 u_int type; 5064 ipf_stack_t *ifs; 5065 { 5066 #ifdef IPFILTER_LOG 5067 # ifndef LARGE_NAT 5068 struct ipnat *np; 5069 int rulen; 5070 # endif 5071 struct natlog natl; 5072 void *items[1]; 5073 size_t sizes[1]; 5074 int types[1]; 5075 5076 natl.nlg_inip = nat->nat_inip6; 5077 natl.nlg_outip = nat->nat_outip6; 5078 natl.nlg_origip = nat->nat_oip6; 5079 natl.nlg_bytes[0] = nat->nat_bytes[0]; 5080 natl.nlg_bytes[1] = nat->nat_bytes[1]; 5081 natl.nlg_pkts[0] = nat->nat_pkts[0]; 5082 natl.nlg_pkts[1] = nat->nat_pkts[1]; 5083 natl.nlg_origport = nat->nat_oport; 5084 natl.nlg_inport = nat->nat_inport; 5085 natl.nlg_outport = nat->nat_outport; 5086 natl.nlg_p = nat->nat_p; 5087 natl.nlg_type = type; 5088 natl.nlg_rule = -1; 5089 natl.nlg_v = nat->nat_v; 5090 # ifndef LARGE_NAT 5091 if (nat->nat_ptr != NULL) { 5092 for (rulen = 0, np = ifs->ifs_nat_list; np; 5093 np = np->in_next, rulen++) 5094 if (np == nat->nat_ptr) { 5095 natl.nlg_rule = rulen; 5096 break; 5097 } 5098 } 5099 # endif 5100 items[0] = &natl; 5101 sizes[0] = sizeof(natl); 5102 types[0] = 0; 5103 5104 (void) ipllog(IPL_LOGNAT, NULL, items, sizes, types, 1, ifs); 5105 #endif 5106 } 5107 5108 5109 #if defined(__OpenBSD__) 5110 /* ------------------------------------------------------------------------ */ 5111 /* Function: nat_ifdetach */ 5112 /* Returns: Nil */ 5113 /* Parameters: ifp(I) - pointer to network interface */ 5114 /* */ 5115 /* Compatibility interface for OpenBSD to trigger the correct updating of */ 5116 /* interface references within IPFilter. */ 5117 /* ------------------------------------------------------------------------ */ 5118 void nat_ifdetach(ifp, ifs) 5119 void *ifp; 5120 ipf_stack_t *ifs; 5121 { 5122 frsync(ifp, ifs); 5123 return; 5124 } 5125 #endif 5126 5127 5128 /* ------------------------------------------------------------------------ */ 5129 /* Function: fr_ipnatderef */ 5130 /* Returns: Nil */ 5131 /* Parameters: inp(I) - pointer to pointer to NAT rule */ 5132 /* Write Locks: ipf_nat */ 5133 /* */ 5134 /* ------------------------------------------------------------------------ */ 5135 void fr_ipnatderef(inp, ifs) 5136 ipnat_t **inp; 5137 ipf_stack_t *ifs; 5138 { 5139 ipnat_t *in; 5140 5141 in = *inp; 5142 *inp = NULL; 5143 in->in_use--; 5144 if (in->in_use == 0 && (in->in_flags & IPN_DELETE)) { 5145 if (in->in_apr) 5146 appr_free(in->in_apr); 5147 KFREE(in); 5148 ifs->ifs_nat_stats.ns_rules--; 5149 #ifdef notdef 5150 #if SOLARIS 5151 if (ifs->ifs_nat_stats.ns_rules == 0) 5152 ifs->ifs_pfil_delayed_copy = 1; 5153 #endif 5154 #endif 5155 } 5156 } 5157 5158 5159 /* ------------------------------------------------------------------------ */ 5160 /* Function: fr_natderef */ 5161 /* Returns: Nil */ 5162 /* Parameters: natp - pointer to pointer to NAT table entry */ 5163 /* ifs - ipf stack instance */ 5164 /* */ 5165 /* Decrement the reference counter for this NAT table entry and free it if */ 5166 /* there are no more things using it. */ 5167 /* */ 5168 /* IF nat_ref == 1 when this function is called, then we have an orphan nat */ 5169 /* structure *because* it only gets called on paths _after_ nat_ref has been*/ 5170 /* incremented. If nat_ref == 1 then we shouldn't decrement it here */ 5171 /* because nat_delete() will do that and send nat_ref to -1. */ 5172 /* */ 5173 /* Holding the lock on nat_lock is required to serialise nat_delete() being */ 5174 /* called from a NAT flush ioctl with a deref happening because of a packet.*/ 5175 /* ------------------------------------------------------------------------ */ 5176 void fr_natderef(natp, ifs) 5177 nat_t **natp; 5178 ipf_stack_t *ifs; 5179 { 5180 nat_t *nat; 5181 5182 nat = *natp; 5183 *natp = NULL; 5184 5185 MUTEX_ENTER(&nat->nat_lock); 5186 if (nat->nat_ref > 1) { 5187 nat->nat_ref--; 5188 MUTEX_EXIT(&nat->nat_lock); 5189 return; 5190 } 5191 MUTEX_EXIT(&nat->nat_lock); 5192 5193 WRITE_ENTER(&ifs->ifs_ipf_nat); 5194 (void) nat_delete(nat, NL_EXPIRE, ifs); 5195 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 5196 } 5197 5198 5199 /* ------------------------------------------------------------------------ */ 5200 /* Function: fr_natclone */ 5201 /* Returns: ipstate_t* - NULL == cloning failed, */ 5202 /* else pointer to new NAT structure */ 5203 /* Parameters: fin(I) - pointer to packet information */ 5204 /* nat(I) - pointer to master NAT structure */ 5205 /* Write Lock: ipf_nat */ 5206 /* */ 5207 /* Create a "duplicate" NAT table entry from the master. */ 5208 /* ------------------------------------------------------------------------ */ 5209 nat_t *fr_natclone(fin, nat) 5210 fr_info_t *fin; 5211 nat_t *nat; 5212 { 5213 frentry_t *fr; 5214 nat_t *clone; 5215 ipnat_t *np; 5216 ipf_stack_t *ifs = fin->fin_ifs; 5217 5218 /* 5219 * Trigger automatic call to nat_flushtable() if the 5220 * table has reached capcity specified by hi watermark. 5221 */ 5222 if (NAT_TAB_WATER_LEVEL(ifs) > ifs->ifs_nat_flush_level_hi) 5223 ifs->ifs_nat_doflush = 1; 5224 5225 /* 5226 * If automatic flushing did not do its job, and the table 5227 * has filled up, don't try to create a new entry. 5228 */ 5229 if (ifs->ifs_nat_stats.ns_inuse >= ifs->ifs_ipf_nattable_max) { 5230 ifs->ifs_nat_stats.ns_memfail++; 5231 return NULL; 5232 } 5233 5234 KMALLOC(clone, nat_t *); 5235 if (clone == NULL) 5236 return NULL; 5237 bcopy((char *)nat, (char *)clone, sizeof(*clone)); 5238 5239 MUTEX_NUKE(&clone->nat_lock); 5240 5241 clone->nat_aps = NULL; 5242 /* 5243 * Initialize all these so that nat_delete() doesn't cause a crash. 5244 */ 5245 clone->nat_tqe.tqe_pnext = NULL; 5246 clone->nat_tqe.tqe_next = NULL; 5247 clone->nat_tqe.tqe_ifq = NULL; 5248 clone->nat_tqe.tqe_parent = clone; 5249 5250 clone->nat_flags &= ~SI_CLONE; 5251 clone->nat_flags |= SI_CLONED; 5252 5253 if (clone->nat_hm) 5254 clone->nat_hm->hm_ref++; 5255 5256 if (nat_insert(clone, fin->fin_rev, ifs) == -1) { 5257 KFREE(clone); 5258 return NULL; 5259 } 5260 np = clone->nat_ptr; 5261 if (np != NULL) { 5262 if (ifs->ifs_nat_logging) 5263 nat_log(clone, (u_int)np->in_redir, ifs); 5264 np->in_use++; 5265 } 5266 fr = clone->nat_fr; 5267 if (fr != NULL) { 5268 MUTEX_ENTER(&fr->fr_lock); 5269 fr->fr_ref++; 5270 MUTEX_EXIT(&fr->fr_lock); 5271 } 5272 5273 /* 5274 * Because the clone is created outside the normal loop of things and 5275 * TCP has special needs in terms of state, initialise the timeout 5276 * state of the new NAT from here. 5277 */ 5278 if (clone->nat_p == IPPROTO_TCP) { 5279 (void) fr_tcp_age(&clone->nat_tqe, fin, ifs->ifs_nat_tqb, 5280 clone->nat_flags); 5281 } 5282 #ifdef IPFILTER_SYNC 5283 clone->nat_sync = ipfsync_new(SMC_NAT, fin, clone); 5284 #endif 5285 if (ifs->ifs_nat_logging) 5286 nat_log(clone, NL_CLONE, ifs); 5287 return clone; 5288 } 5289 5290 5291 /* ------------------------------------------------------------------------ */ 5292 /* Function: nat_wildok */ 5293 /* Returns: int - 1 == packet's ports match wildcards */ 5294 /* 0 == packet's ports don't match wildcards */ 5295 /* Parameters: nat(I) - NAT entry */ 5296 /* sport(I) - source port */ 5297 /* dport(I) - destination port */ 5298 /* flags(I) - wildcard flags */ 5299 /* dir(I) - packet direction */ 5300 /* */ 5301 /* Use NAT entry and packet direction to determine which combination of */ 5302 /* wildcard flags should be used. */ 5303 /* ------------------------------------------------------------------------ */ 5304 int nat_wildok(nat, sport, dport, flags, dir) 5305 nat_t *nat; 5306 int sport; 5307 int dport; 5308 int flags; 5309 int dir; 5310 { 5311 /* 5312 * When called by dir is set to 5313 * nat_inlookup NAT_INBOUND (0) 5314 * nat_outlookup NAT_OUTBOUND (1) 5315 * 5316 * We simply combine the packet's direction in dir with the original 5317 * "intended" direction of that NAT entry in nat->nat_dir to decide 5318 * which combination of wildcard flags to allow. 5319 */ 5320 5321 switch ((dir << 1) | nat->nat_dir) 5322 { 5323 case 3: /* outbound packet / outbound entry */ 5324 if (((nat->nat_inport == sport) || 5325 (flags & SI_W_SPORT)) && 5326 ((nat->nat_oport == dport) || 5327 (flags & SI_W_DPORT))) 5328 return 1; 5329 break; 5330 case 2: /* outbound packet / inbound entry */ 5331 if (((nat->nat_outport == sport) || 5332 (flags & SI_W_DPORT)) && 5333 ((nat->nat_oport == dport) || 5334 (flags & SI_W_SPORT))) 5335 return 1; 5336 break; 5337 case 1: /* inbound packet / outbound entry */ 5338 if (((nat->nat_oport == sport) || 5339 (flags & SI_W_DPORT)) && 5340 ((nat->nat_outport == dport) || 5341 (flags & SI_W_SPORT))) 5342 return 1; 5343 break; 5344 case 0: /* inbound packet / inbound entry */ 5345 if (((nat->nat_oport == sport) || 5346 (flags & SI_W_SPORT)) && 5347 ((nat->nat_outport == dport) || 5348 (flags & SI_W_DPORT))) 5349 return 1; 5350 break; 5351 default: 5352 break; 5353 } 5354 5355 return(0); 5356 } 5357 5358 5359 /* ------------------------------------------------------------------------ */ 5360 /* Function: nat_mssclamp */ 5361 /* Returns: Nil */ 5362 /* Parameters: tcp(I) - pointer to TCP header */ 5363 /* maxmss(I) - value to clamp the TCP MSS to */ 5364 /* csump(I) - pointer to TCP checksum */ 5365 /* */ 5366 /* Check for MSS option and clamp it if necessary. If found and changed, */ 5367 /* then the TCP header checksum will be updated to reflect the change in */ 5368 /* the MSS. */ 5369 /* ------------------------------------------------------------------------ */ 5370 static void nat_mssclamp(tcp, maxmss, csump) 5371 tcphdr_t *tcp; 5372 u_32_t maxmss; 5373 u_short *csump; 5374 { 5375 u_char *cp, *ep, opt; 5376 int hlen, advance; 5377 u_32_t mss, sumd; 5378 5379 hlen = TCP_OFF(tcp) << 2; 5380 if (hlen > sizeof(*tcp)) { 5381 cp = (u_char *)tcp + sizeof(*tcp); 5382 ep = (u_char *)tcp + hlen; 5383 5384 while (cp < ep) { 5385 opt = cp[0]; 5386 if (opt == TCPOPT_EOL) 5387 break; 5388 else if (opt == TCPOPT_NOP) { 5389 cp++; 5390 continue; 5391 } 5392 5393 if (cp + 1 >= ep) 5394 break; 5395 advance = cp[1]; 5396 if ((cp + advance > ep) || (advance <= 0)) 5397 break; 5398 switch (opt) 5399 { 5400 case TCPOPT_MAXSEG: 5401 if (advance != 4) 5402 break; 5403 mss = cp[2] * 256 + cp[3]; 5404 if (mss > maxmss) { 5405 cp[2] = maxmss / 256; 5406 cp[3] = maxmss & 0xff; 5407 CALC_SUMD(mss, maxmss, sumd); 5408 fix_outcksum(csump, sumd); 5409 } 5410 break; 5411 default: 5412 /* ignore unknown options */ 5413 break; 5414 } 5415 5416 cp += advance; 5417 } 5418 } 5419 } 5420 5421 5422 /* ------------------------------------------------------------------------ */ 5423 /* Function: fr_setnatqueue */ 5424 /* Returns: Nil */ 5425 /* Parameters: nat(I)- pointer to NAT structure */ 5426 /* rev(I) - forward(0) or reverse(1) direction */ 5427 /* Locks: ipf_nat (read or write) */ 5428 /* */ 5429 /* Put the NAT entry on its default queue entry, using rev as a helped in */ 5430 /* determining which queue it should be placed on. */ 5431 /* ------------------------------------------------------------------------ */ 5432 void fr_setnatqueue(nat, rev, ifs) 5433 nat_t *nat; 5434 int rev; 5435 ipf_stack_t *ifs; 5436 { 5437 ipftq_t *oifq, *nifq; 5438 5439 if (nat->nat_ptr != NULL) 5440 nifq = nat->nat_ptr->in_tqehead[rev]; 5441 else 5442 nifq = NULL; 5443 5444 if (nifq == NULL) { 5445 switch (nat->nat_p) 5446 { 5447 case IPPROTO_UDP : 5448 nifq = &ifs->ifs_nat_udptq; 5449 break; 5450 case IPPROTO_ICMP : 5451 nifq = &ifs->ifs_nat_icmptq; 5452 break; 5453 case IPPROTO_TCP : 5454 nifq = ifs->ifs_nat_tqb + nat->nat_tqe.tqe_state[rev]; 5455 break; 5456 default : 5457 nifq = &ifs->ifs_nat_iptq; 5458 break; 5459 } 5460 } 5461 5462 oifq = nat->nat_tqe.tqe_ifq; 5463 /* 5464 * If it's currently on a timeout queue, move it from one queue to 5465 * another, else put it on the end of the newly determined queue. 5466 */ 5467 if (oifq != NULL) 5468 fr_movequeue(&nat->nat_tqe, oifq, nifq, ifs); 5469 else 5470 fr_queueappend(&nat->nat_tqe, nifq, nat, ifs); 5471 return; 5472 } 5473 5474 /* ------------------------------------------------------------------------ */ 5475 /* Function: nat_getnext */ 5476 /* Returns: int - 0 == ok, else error */ 5477 /* Parameters: t(I) - pointer to ipftoken structure */ 5478 /* itp(I) - pointer to ipfgeniter_t structure */ 5479 /* ifs - ipf stack instance */ 5480 /* */ 5481 /* Fetch the next nat/ipnat/hostmap structure pointer from the linked list */ 5482 /* and copy it out to the storage space pointed to by itp. The next item */ 5483 /* in the list to look at is put back in the ipftoken struture. */ 5484 /* ------------------------------------------------------------------------ */ 5485 static int nat_getnext(t, itp, ifs) 5486 ipftoken_t *t; 5487 ipfgeniter_t *itp; 5488 ipf_stack_t *ifs; 5489 { 5490 hostmap_t *hm, *nexthm = NULL, zerohm; 5491 ipnat_t *ipn, *nextipnat = NULL, zeroipn; 5492 nat_t *nat, *nextnat = NULL, zeronat; 5493 int error = 0, count; 5494 char *dst; 5495 5496 if (itp->igi_nitems == 0) 5497 return EINVAL; 5498 5499 READ_ENTER(&ifs->ifs_ipf_nat); 5500 5501 /* 5502 * Get "previous" entry from the token and find the next entry. 5503 */ 5504 switch (itp->igi_type) 5505 { 5506 case IPFGENITER_HOSTMAP : 5507 hm = t->ipt_data; 5508 if (hm == NULL) { 5509 nexthm = ifs->ifs_ipf_hm_maplist; 5510 } else { 5511 nexthm = hm->hm_next; 5512 } 5513 break; 5514 5515 case IPFGENITER_IPNAT : 5516 ipn = t->ipt_data; 5517 if (ipn == NULL) { 5518 nextipnat = ifs->ifs_nat_list; 5519 } else { 5520 nextipnat = ipn->in_next; 5521 } 5522 break; 5523 5524 case IPFGENITER_NAT : 5525 nat = t->ipt_data; 5526 if (nat == NULL) { 5527 nextnat = ifs->ifs_nat_instances; 5528 } else { 5529 nextnat = nat->nat_next; 5530 } 5531 break; 5532 default : 5533 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 5534 return EINVAL; 5535 } 5536 5537 dst = itp->igi_data; 5538 for (count = itp->igi_nitems; count > 0; count--) { 5539 /* 5540 * If we found an entry, add a reference to it and update the token. 5541 * Otherwise, zero out data to be returned and NULL out token. 5542 */ 5543 switch (itp->igi_type) 5544 { 5545 case IPFGENITER_HOSTMAP : 5546 if (nexthm != NULL) { 5547 ATOMIC_INC32(nexthm->hm_ref); 5548 t->ipt_data = nexthm; 5549 } else { 5550 bzero(&zerohm, sizeof(zerohm)); 5551 nexthm = &zerohm; 5552 t->ipt_data = NULL; 5553 } 5554 break; 5555 case IPFGENITER_IPNAT : 5556 if (nextipnat != NULL) { 5557 ATOMIC_INC32(nextipnat->in_use); 5558 t->ipt_data = nextipnat; 5559 } else { 5560 bzero(&zeroipn, sizeof(zeroipn)); 5561 nextipnat = &zeroipn; 5562 t->ipt_data = NULL; 5563 } 5564 break; 5565 case IPFGENITER_NAT : 5566 if (nextnat != NULL) { 5567 MUTEX_ENTER(&nextnat->nat_lock); 5568 nextnat->nat_ref++; 5569 MUTEX_EXIT(&nextnat->nat_lock); 5570 t->ipt_data = nextnat; 5571 } else { 5572 bzero(&zeronat, sizeof(zeronat)); 5573 nextnat = &zeronat; 5574 t->ipt_data = NULL; 5575 } 5576 break; 5577 default : 5578 break; 5579 } 5580 5581 /* 5582 * Now that we have ref, it's save to give up lock. 5583 */ 5584 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 5585 5586 /* 5587 * Copy out data and clean up references and token as needed. 5588 */ 5589 switch (itp->igi_type) 5590 { 5591 case IPFGENITER_HOSTMAP : 5592 error = COPYOUT(nexthm, dst, sizeof(*nexthm)); 5593 if (error != 0) 5594 error = EFAULT; 5595 if (t->ipt_data == NULL) { 5596 ipf_freetoken(t, ifs); 5597 break; 5598 } else { 5599 if (hm != NULL) { 5600 WRITE_ENTER(&ifs->ifs_ipf_nat); 5601 fr_hostmapdel(&hm); 5602 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 5603 } 5604 if (nexthm->hm_next == NULL) { 5605 ipf_freetoken(t, ifs); 5606 break; 5607 } 5608 dst += sizeof(*nexthm); 5609 hm = nexthm; 5610 nexthm = nexthm->hm_next; 5611 } 5612 break; 5613 5614 case IPFGENITER_IPNAT : 5615 error = COPYOUT(nextipnat, dst, sizeof(*nextipnat)); 5616 if (error != 0) 5617 error = EFAULT; 5618 if (t->ipt_data == NULL) { 5619 ipf_freetoken(t, ifs); 5620 break; 5621 } else { 5622 if (ipn != NULL) { 5623 WRITE_ENTER(&ifs->ifs_ipf_nat); 5624 fr_ipnatderef(&ipn, ifs); 5625 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 5626 } 5627 if (nextipnat->in_next == NULL) { 5628 ipf_freetoken(t, ifs); 5629 break; 5630 } 5631 dst += sizeof(*nextipnat); 5632 ipn = nextipnat; 5633 nextipnat = nextipnat->in_next; 5634 } 5635 break; 5636 5637 case IPFGENITER_NAT : 5638 error = COPYOUT(nextnat, dst, sizeof(*nextnat)); 5639 if (error != 0) 5640 error = EFAULT; 5641 if (t->ipt_data == NULL) { 5642 ipf_freetoken(t, ifs); 5643 break; 5644 } else { 5645 if (nat != NULL) 5646 fr_natderef(&nat, ifs); 5647 if (nextnat->nat_next == NULL) { 5648 ipf_freetoken(t, ifs); 5649 break; 5650 } 5651 dst += sizeof(*nextnat); 5652 nat = nextnat; 5653 nextnat = nextnat->nat_next; 5654 } 5655 break; 5656 default : 5657 break; 5658 } 5659 5660 if ((count == 1) || (error != 0)) 5661 break; 5662 5663 READ_ENTER(&ifs->ifs_ipf_nat); 5664 } 5665 5666 return error; 5667 } 5668 5669 5670 /* ------------------------------------------------------------------------ */ 5671 /* Function: nat_iterator */ 5672 /* Returns: int - 0 == ok, else error */ 5673 /* Parameters: token(I) - pointer to ipftoken structure */ 5674 /* itp(I) - pointer to ipfgeniter_t structure */ 5675 /* */ 5676 /* This function acts as a handler for the SIOCGENITER ioctls that use a */ 5677 /* generic structure to iterate through a list. There are three different */ 5678 /* linked lists of NAT related information to go through: NAT rules, active */ 5679 /* NAT mappings and the NAT fragment cache. */ 5680 /* ------------------------------------------------------------------------ */ 5681 static int nat_iterator(token, itp, ifs) 5682 ipftoken_t *token; 5683 ipfgeniter_t *itp; 5684 ipf_stack_t *ifs; 5685 { 5686 int error; 5687 5688 if (itp->igi_data == NULL) 5689 return EFAULT; 5690 5691 token->ipt_subtype = itp->igi_type; 5692 5693 switch (itp->igi_type) 5694 { 5695 case IPFGENITER_HOSTMAP : 5696 case IPFGENITER_IPNAT : 5697 case IPFGENITER_NAT : 5698 error = nat_getnext(token, itp, ifs); 5699 break; 5700 case IPFGENITER_NATFRAG : 5701 error = fr_nextfrag(token, itp, &ifs->ifs_ipfr_natlist, 5702 &ifs->ifs_ipfr_nattail, 5703 &ifs->ifs_ipf_natfrag, ifs); 5704 break; 5705 default : 5706 error = EINVAL; 5707 break; 5708 } 5709 5710 return error; 5711 } 5712 5713 5714 /* ---------------------------------------------------------------------- */ 5715 /* Function: nat_flushtable */ 5716 /* Returns: int - 0 == success, -1 == failure */ 5717 /* Parameters: flush_option - how to flush the active NAT table */ 5718 /* ifs - ipf stack instance */ 5719 /* Write Locks: ipf_nat */ 5720 /* */ 5721 /* Flush NAT tables. Three actions currently defined: */ 5722 /* */ 5723 /* FLUSH_TABLE_ALL : Flush all NAT table entries */ 5724 /* */ 5725 /* FLUSH_TABLE_CLOSING : Flush entries with TCP connections which */ 5726 /* have started to close on both ends using */ 5727 /* ipf_flushclosing(). */ 5728 /* */ 5729 /* FLUSH_TABLE_EXTRA : First, flush entries which are "almost" closed. */ 5730 /* Then, if needed, flush entries with TCP */ 5731 /* connections which have been idle for a long */ 5732 /* time with ipf_extraflush(). */ 5733 /* ---------------------------------------------------------------------- */ 5734 static int nat_flushtable(flush_option, ifs) 5735 int flush_option; 5736 ipf_stack_t *ifs; 5737 { 5738 nat_t *nat, *natn; 5739 int removed; 5740 SPL_INT(s); 5741 5742 removed = 0; 5743 5744 SPL_NET(s); 5745 switch (flush_option) 5746 { 5747 case FLUSH_TABLE_ALL: 5748 natn = ifs->ifs_nat_instances; 5749 while ((nat = natn) != NULL) { 5750 natn = nat->nat_next; 5751 if (nat_delete(nat, NL_FLUSH, ifs) == 0) 5752 removed++; 5753 } 5754 break; 5755 5756 case FLUSH_TABLE_CLOSING: 5757 removed = ipf_flushclosing(NAT_FLUSH, 5758 IPF_TCPS_CLOSE_WAIT, 5759 ifs->ifs_nat_tqb, 5760 ifs->ifs_nat_utqe, 5761 ifs); 5762 break; 5763 5764 case FLUSH_TABLE_EXTRA: 5765 removed = ipf_flushclosing(NAT_FLUSH, 5766 IPF_TCPS_FIN_WAIT_2, 5767 ifs->ifs_nat_tqb, 5768 ifs->ifs_nat_utqe, 5769 ifs); 5770 5771 /* 5772 * Be sure we haven't done this in the last 10 seconds. 5773 */ 5774 if (ifs->ifs_fr_ticks - ifs->ifs_nat_last_force_flush < 5775 IPF_TTLVAL(10)) 5776 break; 5777 ifs->ifs_nat_last_force_flush = ifs->ifs_fr_ticks; 5778 removed += ipf_extraflush(NAT_FLUSH, 5779 &ifs->ifs_nat_tqb[IPF_TCPS_ESTABLISHED], 5780 ifs->ifs_nat_utqe, 5781 ifs); 5782 break; 5783 5784 default: /* Flush Nothing */ 5785 break; 5786 } 5787 5788 SPL_X(s); 5789 return (removed); 5790 } 5791 5792 5793 /* ------------------------------------------------------------------------ */ 5794 /* Function: nat_uncreate */ 5795 /* Returns: Nil */ 5796 /* Parameters: fin(I) - pointer to packet information */ 5797 /* */ 5798 /* This function is used to remove a NAT entry from the NAT table when we */ 5799 /* decide that the create was actually in error. It is thus assumed that */ 5800 /* fin_flx will have both FI_NATED and FI_NATNEW set. Because we're dealing */ 5801 /* with the translated packet (not the original), we have to reverse the */ 5802 /* lookup. Although doing the lookup is expensive (relatively speaking), it */ 5803 /* is not anticipated that this will be a frequent occurance for normal */ 5804 /* traffic patterns. */ 5805 /* ------------------------------------------------------------------------ */ 5806 void nat_uncreate(fin) 5807 fr_info_t *fin; 5808 { 5809 ipf_stack_t *ifs = fin->fin_ifs; 5810 int nflags; 5811 nat_t *nat; 5812 5813 switch (fin->fin_p) 5814 { 5815 case IPPROTO_TCP : 5816 nflags = IPN_TCP; 5817 break; 5818 case IPPROTO_UDP : 5819 nflags = IPN_UDP; 5820 break; 5821 default : 5822 nflags = 0; 5823 break; 5824 } 5825 5826 WRITE_ENTER(&ifs->ifs_ipf_nat); 5827 5828 if (fin->fin_out == 0) { 5829 nat = nat_outlookup(fin, nflags, (u_int)fin->fin_p, 5830 fin->fin_dst, fin->fin_src); 5831 } else { 5832 nat = nat_inlookup(fin, nflags, (u_int)fin->fin_p, 5833 fin->fin_src, fin->fin_dst); 5834 } 5835 5836 if (nat != NULL) { 5837 ifs->ifs_nat_stats.ns_uncreate[fin->fin_out][0]++; 5838 (void) nat_delete(nat, NL_DESTROY, ifs); 5839 } else { 5840 ifs->ifs_nat_stats.ns_uncreate[fin->fin_out][1]++; 5841 } 5842 5843 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 5844 } 5845
Indexes created Sun Nov 22 02:52:53 UTC 2009
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