1 /* 2 * Copyright (C) 1995-2003 by Darren Reed. 3 * 4 * See the IPFILTER.LICENCE file for details on licencing. 5 * 6 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 7 * Use is subject to license terms. 8 */ 9 10 #pragma ident "%Z%%M% %I% %E% SMI"$ 11 12 #if defined(KERNEL) || defined(_KERNEL) 13 # undef KERNEL 14 # undef _KERNEL 15 # define KERNEL 1 16 # define _KERNEL 1 17 #endif 18 #include <sys/errno.h> 19 #include <sys/types.h> 20 #include <sys/param.h> 21 #include <sys/time.h> 22 #include <sys/file.h> 23 #if defined(__NetBSD__) && (NetBSD >= 199905) && !defined(IPFILTER_LKM) && \ 24 defined(_KERNEL) 25 # include "opt_ipfilter_log.h" 26 #endif 27 #if !defined(_KERNEL) 28 # include <stdio.h> 29 # include <string.h> 30 # include <stdlib.h> 31 # define _KERNEL 32 # ifdef __OpenBSD__ 33 struct file; 34 # endif 35 # include <sys/uio.h> 36 # undef _KERNEL 37 #endif 38 #if defined(_KERNEL) && (__FreeBSD_version >= 220000) 39 # include <sys/filio.h> 40 # include <sys/fcntl.h> 41 #else 42 # include <sys/ioctl.h> 43 #endif 44 #if !defined(AIX) 45 # include <sys/fcntl.h> 46 #endif 47 #if !defined(linux) 48 # include <sys/protosw.h> 49 #endif 50 #include <sys/socket.h> 51 #if defined(_KERNEL) 52 # include <sys/systm.h> 53 # if !defined(__SVR4) && !defined(__svr4__) 54 # include <sys/mbuf.h> 55 # endif 56 #endif 57 #if defined(__SVR4) || defined(__svr4__) 58 # include <sys/filio.h> 59 # include <sys/byteorder.h> 60 # ifdef _KERNEL 61 # include <sys/dditypes.h> 62 # endif 63 # include <sys/stream.h> 64 # include <sys/kmem.h> 65 #endif 66 #if __FreeBSD_version >= 300000 67 # include <sys/queue.h> 68 #endif 69 #include <net/if.h> 70 #if __FreeBSD_version >= 300000 71 # include <net/if_var.h> 72 # if defined(_KERNEL) && !defined(IPFILTER_LKM) 73 # include "opt_ipfilter.h" 74 # endif 75 #endif 76 #ifdef sun 77 # include <net/af.h> 78 #endif 79 #include <net/route.h> 80 #include <netinet/in.h> 81 #include <netinet/in_systm.h> 82 #include <netinet/ip.h> 83 84 #ifdef RFC1825 85 # include <vpn/md5.h> 86 # include <vpn/ipsec.h> 87 extern struct ifnet vpnif; 88 #endif 89 90 #if !defined(linux) 91 # include <netinet/ip_var.h> 92 #endif 93 #include <netinet/tcp.h> 94 #include <netinet/udp.h> 95 #include <netinet/ip_icmp.h> 96 #include "netinet/ip_compat.h" 97 #include <netinet/tcpip.h> 98 #include "netinet/ip_fil.h" 99 #include "netinet/ip_nat.h" 100 #include "netinet/ip_frag.h" 101 #include "netinet/ip_state.h" 102 #include "netinet/ip_proxy.h" 103 #include "netinet/ipf_stack.h" 104 #ifdef IPFILTER_SYNC 105 #include "netinet/ip_sync.h" 106 #endif 107 #if (__FreeBSD_version >= 300000) 108 # include <sys/malloc.h> 109 #endif 110 /* END OF INCLUDES */ 111 112 #undef SOCKADDR_IN 113 #define SOCKADDR_IN struct sockaddr_in 114 115 #if !defined(lint) 116 static const char sccsid[] = "@(#)ip_nat.c 1.11 6/5/96 (C) 1995 Darren Reed"; 117 static const char rcsid[] = "@(#)$Id: ip_nat.c,v 2.195.2.42 2005/08/11 19:51:36 darrenr Exp $"; 118 #endif 119 120 121 /* ======================================================================== */ 122 /* How the NAT is organised and works. */ 123 /* */ 124 /* Inside (interface y) NAT Outside (interface x) */ 125 /* -------------------- -+- ------------------------------------- */ 126 /* Packet going | out, processsed by fr_checknatout() for x */ 127 /* ------------> | ------------> */ 128 /* src=10.1.1.1 | src=192.1.1.1 */ 129 /* | */ 130 /* | in, processed by fr_checknatin() for x */ 131 /* <------------ | <------------ */ 132 /* dst=10.1.1.1 | dst=192.1.1.1 */ 133 /* -------------------- -+- ------------------------------------- */ 134 /* fr_checknatout() - changes ip_src and if required, sport */ 135 /* - creates a new mapping, if required. */ 136 /* fr_checknatin() - changes ip_dst and if required, dport */ 137 /* */ 138 /* In the NAT table, internal source is recorded as "in" and externally */ 139 /* seen as "out". */ 140 /* ======================================================================== */ 141 142 143 static int nat_flushtable __P((ipf_stack_t *)); 144 static int nat_clearlist __P((ipf_stack_t *)); 145 static void nat_addnat __P((struct ipnat *, ipf_stack_t *)); 146 static void nat_addrdr __P((struct ipnat *, ipf_stack_t *)); 147 static void nat_delete __P((struct nat *, int, ipf_stack_t *)); 148 static void nat_delrdr __P((struct ipnat *)); 149 static void nat_delnat __P((struct ipnat *)); 150 static int fr_natgetent __P((caddr_t, ipf_stack_t *)); 151 static int fr_natgetsz __P((caddr_t, ipf_stack_t *)); 152 static int fr_natputent __P((caddr_t, int, ipf_stack_t *)); 153 static void nat_tabmove __P((nat_t *, ipf_stack_t *)); 154 static int nat_match __P((fr_info_t *, ipnat_t *)); 155 static INLINE int nat_newmap __P((fr_info_t *, nat_t *, natinfo_t *)); 156 static INLINE int nat_newrdr __P((fr_info_t *, nat_t *, natinfo_t *)); 157 static hostmap_t *nat_hostmap __P((ipnat_t *, struct in_addr, 158 struct in_addr, struct in_addr, u_32_t, 159 ipf_stack_t *)); 160 static void nat_hostmapdel __P((struct hostmap *)); 161 static INLINE int nat_icmpquerytype4 __P((int)); 162 static int nat_siocaddnat __P((ipnat_t *, ipnat_t **, int, 163 ipf_stack_t *)); 164 static void nat_siocdelnat __P((ipnat_t *, ipnat_t **, int, 165 ipf_stack_t *)); 166 static INLINE int nat_icmperrortype4 __P((int)); 167 static INLINE int nat_finalise __P((fr_info_t *, nat_t *, natinfo_t *, 168 tcphdr_t *, nat_t **, int)); 169 static INLINE int nat_resolverule __P((ipnat_t *, ipf_stack_t *)); 170 static nat_t *fr_natclone __P((fr_info_t *, nat_t *)); 171 static void nat_mssclamp __P((tcphdr_t *, u_32_t, u_short *)); 172 static INLINE int nat_wildok __P((nat_t *, int, int, int, int)); 173 static int nat_getnext __P((ipftoken_t *, ipfgeniter_t *, ipf_stack_t *)); 174 static int nat_iterator __P((ipftoken_t *, ipfgeniter_t *, ipf_stack_t *)); 175 static int nat_extraflush __P((int, ipf_stack_t *)); 176 static int nat_earlydrop __P((ipftq_t *, int, ipf_stack_t *)); 177 static int nat_flushclosing __P((int, ipf_stack_t *)); 178 179 180 /* 181 * Below we declare a list of constants used only in the nat_extraflush() 182 * routine. We are placing it here, instead of in nat_extraflush() itself, 183 * because we want to make it visible to tools such as mdb, nm etc., so the 184 * values can easily be altered during debugging. 185 */ 186 static const int idletime_tab[] = { 187 IPF_TTLVAL(30), /* 30 seconds */ 188 IPF_TTLVAL(1800), /* 30 minutes */ 189 IPF_TTLVAL(43200), /* 12 hours */ 190 IPF_TTLVAL(345600), /* 4 days */ 191 }; 192 193 194 /* ------------------------------------------------------------------------ */ 195 /* Function: fr_natinit */ 196 /* Returns: int - 0 == success, -1 == failure */ 197 /* Parameters: Nil */ 198 /* */ 199 /* Initialise all of the NAT locks, tables and other structures. */ 200 /* ------------------------------------------------------------------------ */ 201 int fr_natinit(ifs) 202 ipf_stack_t *ifs; 203 { 204 int i; 205 206 KMALLOCS(ifs->ifs_nat_table[0], nat_t **, 207 sizeof(nat_t *) * ifs->ifs_ipf_nattable_sz); 208 if (ifs->ifs_nat_table[0] != NULL) 209 bzero((char *)ifs->ifs_nat_table[0], 210 ifs->ifs_ipf_nattable_sz * sizeof(nat_t *)); 211 else 212 return -1; 213 214 KMALLOCS(ifs->ifs_nat_table[1], nat_t **, 215 sizeof(nat_t *) * ifs->ifs_ipf_nattable_sz); 216 if (ifs->ifs_nat_table[1] != NULL) 217 bzero((char *)ifs->ifs_nat_table[1], 218 ifs->ifs_ipf_nattable_sz * sizeof(nat_t *)); 219 else 220 return -2; 221 222 KMALLOCS(ifs->ifs_nat_rules, ipnat_t **, 223 sizeof(ipnat_t *) * ifs->ifs_ipf_natrules_sz); 224 if (ifs->ifs_nat_rules != NULL) 225 bzero((char *)ifs->ifs_nat_rules, 226 ifs->ifs_ipf_natrules_sz * sizeof(ipnat_t *)); 227 else 228 return -3; 229 230 KMALLOCS(ifs->ifs_rdr_rules, ipnat_t **, 231 sizeof(ipnat_t *) * ifs->ifs_ipf_rdrrules_sz); 232 if (ifs->ifs_rdr_rules != NULL) 233 bzero((char *)ifs->ifs_rdr_rules, 234 ifs->ifs_ipf_rdrrules_sz * sizeof(ipnat_t *)); 235 else 236 return -4; 237 238 KMALLOCS(ifs->ifs_maptable, hostmap_t **, 239 sizeof(hostmap_t *) * ifs->ifs_ipf_hostmap_sz); 240 if (ifs->ifs_maptable != NULL) 241 bzero((char *)ifs->ifs_maptable, 242 sizeof(hostmap_t *) * ifs->ifs_ipf_hostmap_sz); 243 else 244 return -5; 245 246 ifs->ifs_ipf_hm_maplist = NULL; 247 248 KMALLOCS(ifs->ifs_nat_stats.ns_bucketlen[0], u_long *, 249 ifs->ifs_ipf_nattable_sz * sizeof(u_long)); 250 if (ifs->ifs_nat_stats.ns_bucketlen[0] == NULL) 251 return -1; 252 bzero((char *)ifs->ifs_nat_stats.ns_bucketlen[0], 253 ifs->ifs_ipf_nattable_sz * sizeof(u_long)); 254 255 KMALLOCS(ifs->ifs_nat_stats.ns_bucketlen[1], u_long *, 256 ifs->ifs_ipf_nattable_sz * sizeof(u_long)); 257 if (ifs->ifs_nat_stats.ns_bucketlen[1] == NULL) 258 return -1; 259 bzero((char *)ifs->ifs_nat_stats.ns_bucketlen[1], 260 ifs->ifs_ipf_nattable_sz * sizeof(u_long)); 261 262 if (ifs->ifs_fr_nat_maxbucket == 0) { 263 for (i = ifs->ifs_ipf_nattable_sz; i > 0; i >>= 1) 264 ifs->ifs_fr_nat_maxbucket++; 265 ifs->ifs_fr_nat_maxbucket *= 2; 266 } 267 268 fr_sttab_init(ifs->ifs_nat_tqb, ifs); 269 /* 270 * Increase this because we may have "keep state" following this too 271 * and packet storms can occur if this is removed too quickly. 272 */ 273 ifs->ifs_nat_tqb[IPF_TCPS_CLOSED].ifq_ttl = ifs->ifs_fr_tcplastack; 274 ifs->ifs_nat_tqb[IPF_TCP_NSTATES - 1].ifq_next = &ifs->ifs_nat_udptq; 275 ifs->ifs_nat_udptq.ifq_ttl = ifs->ifs_fr_defnatage; 276 ifs->ifs_nat_udptq.ifq_ref = 1; 277 ifs->ifs_nat_udptq.ifq_head = NULL; 278 ifs->ifs_nat_udptq.ifq_tail = &ifs->ifs_nat_udptq.ifq_head; 279 MUTEX_INIT(&ifs->ifs_nat_udptq.ifq_lock, "nat ipftq udp tab"); 280 ifs->ifs_nat_udptq.ifq_next = &ifs->ifs_nat_icmptq; 281 ifs->ifs_nat_icmptq.ifq_ttl = ifs->ifs_fr_defnaticmpage; 282 ifs->ifs_nat_icmptq.ifq_ref = 1; 283 ifs->ifs_nat_icmptq.ifq_head = NULL; 284 ifs->ifs_nat_icmptq.ifq_tail = &ifs->ifs_nat_icmptq.ifq_head; 285 MUTEX_INIT(&ifs->ifs_nat_icmptq.ifq_lock, "nat icmp ipftq tab"); 286 ifs->ifs_nat_icmptq.ifq_next = &ifs->ifs_nat_iptq; 287 ifs->ifs_nat_iptq.ifq_ttl = ifs->ifs_fr_defnatipage; 288 ifs->ifs_nat_iptq.ifq_ref = 1; 289 ifs->ifs_nat_iptq.ifq_head = NULL; 290 ifs->ifs_nat_iptq.ifq_tail = &ifs->ifs_nat_iptq.ifq_head; 291 MUTEX_INIT(&ifs->ifs_nat_iptq.ifq_lock, "nat ip ipftq tab"); 292 ifs->ifs_nat_iptq.ifq_next = NULL; 293 294 for (i = 0; i < IPF_TCP_NSTATES; i++) { 295 if (ifs->ifs_nat_tqb[i].ifq_ttl < ifs->ifs_fr_defnaticmpage) 296 ifs->ifs_nat_tqb[i].ifq_ttl = ifs->ifs_fr_defnaticmpage; 297 #ifdef LARGE_NAT 298 else if (ifs->ifs_nat_tqb[i].ifq_ttl > ifs->ifs_fr_defnatage) 299 ifs->ifs_nat_tqb[i].ifq_ttl = ifs->ifs_fr_defnatage; 300 #endif 301 } 302 303 /* 304 * Increase this because we may have "keep state" following 305 * this too and packet storms can occur if this is removed 306 * too quickly. 307 */ 308 ifs->ifs_nat_tqb[IPF_TCPS_CLOSED].ifq_ttl = 309 ifs->ifs_nat_tqb[IPF_TCPS_LAST_ACK].ifq_ttl; 310 311 RWLOCK_INIT(&ifs->ifs_ipf_nat, "ipf IP NAT rwlock"); 312 RWLOCK_INIT(&ifs->ifs_ipf_natfrag, "ipf IP NAT-Frag rwlock"); 313 MUTEX_INIT(&ifs->ifs_ipf_nat_new, "ipf nat new mutex"); 314 MUTEX_INIT(&ifs->ifs_ipf_natio, "ipf nat io mutex"); 315 316 ifs->ifs_fr_nat_init = 1; 317 318 return 0; 319 } 320 321 322 /* ------------------------------------------------------------------------ */ 323 /* Function: nat_addrdr */ 324 /* Returns: Nil */ 325 /* Parameters: n(I) - pointer to NAT rule to add */ 326 /* */ 327 /* Adds a redirect rule to the hash table of redirect rules and the list of */ 328 /* loaded NAT rules. Updates the bitmask indicating which netmasks are in */ 329 /* use by redirect rules. */ 330 /* ------------------------------------------------------------------------ */ 331 static void nat_addrdr(n, ifs) 332 ipnat_t *n; 333 ipf_stack_t *ifs; 334 { 335 ipnat_t **np; 336 u_32_t j; 337 u_int hv; 338 int k; 339 340 k = count4bits(n->in_outmsk); 341 if ((k >= 0) && (k != 32)) 342 ifs->ifs_rdr_masks |= 1 << k; 343 j = (n->in_outip & n->in_outmsk); 344 hv = NAT_HASH_FN(j, 0, ifs->ifs_ipf_rdrrules_sz); 345 np = ifs->ifs_rdr_rules + hv; 346 while (*np != NULL) 347 np = &(*np)->in_rnext; 348 n->in_rnext = NULL; 349 n->in_prnext = np; 350 n->in_hv = hv; 351 *np = n; 352 } 353 354 355 /* ------------------------------------------------------------------------ */ 356 /* Function: nat_addnat */ 357 /* Returns: Nil */ 358 /* Parameters: n(I) - pointer to NAT rule to add */ 359 /* */ 360 /* Adds a NAT map rule to the hash table of rules and the list of loaded */ 361 /* NAT rules. Updates the bitmask indicating which netmasks are in use by */ 362 /* redirect rules. */ 363 /* ------------------------------------------------------------------------ */ 364 static void nat_addnat(n, ifs) 365 ipnat_t *n; 366 ipf_stack_t *ifs; 367 { 368 ipnat_t **np; 369 u_32_t j; 370 u_int hv; 371 int k; 372 373 k = count4bits(n->in_inmsk); 374 if ((k >= 0) && (k != 32)) 375 ifs->ifs_nat_masks |= 1 << k; 376 j = (n->in_inip & n->in_inmsk); 377 hv = NAT_HASH_FN(j, 0, ifs->ifs_ipf_natrules_sz); 378 np = ifs->ifs_nat_rules + hv; 379 while (*np != NULL) 380 np = &(*np)->in_mnext; 381 n->in_mnext = NULL; 382 n->in_pmnext = np; 383 n->in_hv = hv; 384 *np = n; 385 } 386 387 388 /* ------------------------------------------------------------------------ */ 389 /* Function: nat_delrdr */ 390 /* Returns: Nil */ 391 /* Parameters: n(I) - pointer to NAT rule to delete */ 392 /* */ 393 /* Removes a redirect rule from the hash table of redirect rules. */ 394 /* ------------------------------------------------------------------------ */ 395 static void nat_delrdr(n) 396 ipnat_t *n; 397 { 398 if (n->in_rnext) 399 n->in_rnext->in_prnext = n->in_prnext; 400 *n->in_prnext = n->in_rnext; 401 } 402 403 404 /* ------------------------------------------------------------------------ */ 405 /* Function: nat_delnat */ 406 /* Returns: Nil */ 407 /* Parameters: n(I) - pointer to NAT rule to delete */ 408 /* */ 409 /* Removes a NAT map rule from the hash table of NAT map rules. */ 410 /* ------------------------------------------------------------------------ */ 411 static void nat_delnat(n) 412 ipnat_t *n; 413 { 414 if (n->in_mnext != NULL) 415 n->in_mnext->in_pmnext = n->in_pmnext; 416 *n->in_pmnext = n->in_mnext; 417 } 418 419 420 /* ------------------------------------------------------------------------ */ 421 /* Function: nat_hostmap */ 422 /* Returns: struct hostmap* - NULL if no hostmap could be created, */ 423 /* else a pointer to the hostmapping to use */ 424 /* Parameters: np(I) - pointer to NAT rule */ 425 /* real(I) - real IP address */ 426 /* map(I) - mapped IP address */ 427 /* port(I) - destination port number */ 428 /* Write Locks: ipf_nat */ 429 /* */ 430 /* Check if an ip address has already been allocated for a given mapping */ 431 /* that is not doing port based translation. If is not yet allocated, then */ 432 /* create a new entry if a non-NULL NAT rule pointer has been supplied. */ 433 /* ------------------------------------------------------------------------ */ 434 static struct hostmap *nat_hostmap(np, src, dst, map, port, ifs) 435 ipnat_t *np; 436 struct in_addr src; 437 struct in_addr dst; 438 struct in_addr map; 439 u_32_t port; 440 ipf_stack_t *ifs; 441 { 442 hostmap_t *hm; 443 u_int hv; 444 445 hv = (src.s_addr ^ dst.s_addr); 446 hv += src.s_addr; 447 hv += dst.s_addr; 448 hv %= HOSTMAP_SIZE; 449 for (hm = ifs->ifs_maptable[hv]; hm; hm = hm->hm_next) 450 if ((hm->hm_srcip.s_addr == src.s_addr) && 451 (hm->hm_dstip.s_addr == dst.s_addr) && 452 ((np == NULL) || (np == hm->hm_ipnat)) && 453 ((port == 0) || (port == hm->hm_port))) { 454 hm->hm_ref++; 455 return hm; 456 } 457 458 if (np == NULL) 459 return NULL; 460 461 KMALLOC(hm, hostmap_t *); 462 if (hm) { 463 hm->hm_hnext = ifs->ifs_ipf_hm_maplist; 464 hm->hm_phnext = &ifs->ifs_ipf_hm_maplist; 465 if (ifs->ifs_ipf_hm_maplist != NULL) 466 ifs->ifs_ipf_hm_maplist->hm_phnext = &hm->hm_hnext; 467 ifs->ifs_ipf_hm_maplist = hm; 468 469 hm->hm_next = ifs->ifs_maptable[hv]; 470 hm->hm_pnext = ifs->ifs_maptable + hv; 471 if (ifs->ifs_maptable[hv] != NULL) 472 ifs->ifs_maptable[hv]->hm_pnext = &hm->hm_next; 473 ifs->ifs_maptable[hv] = hm; 474 hm->hm_ipnat = np; 475 hm->hm_srcip = src; 476 hm->hm_dstip = dst; 477 hm->hm_mapip = map; 478 hm->hm_ref = 1; 479 hm->hm_port = port; 480 } 481 return hm; 482 } 483 484 485 /* ------------------------------------------------------------------------ */ 486 /* Function: nat_hostmapdel */ 487 /* Returns: Nil */ 488 /* Parameters: hm(I) - pointer to hostmap structure */ 489 /* Write Locks: ipf_nat */ 490 /* */ 491 /* Decrement the references to this hostmap structure by one. If this */ 492 /* reaches zero then remove it and free it. */ 493 /* ------------------------------------------------------------------------ */ 494 static void nat_hostmapdel(hm) 495 struct hostmap *hm; 496 { 497 hm->hm_ref--; 498 if (hm->hm_ref == 0) { 499 if (hm->hm_next) 500 hm->hm_next->hm_pnext = hm->hm_pnext; 501 *hm->hm_pnext = hm->hm_next; 502 if (hm->hm_hnext) 503 hm->hm_hnext->hm_phnext = hm->hm_phnext; 504 *hm->hm_phnext = hm->hm_hnext; 505 KFREE(hm); 506 } 507 } 508 509 void fr_hostmapderef(hmp) 510 struct hostmap **hmp; 511 { 512 struct hostmap *hm; 513 514 hm = *hmp; 515 *hmp = NULL; 516 hm->hm_ref--; 517 if (hm->hm_ref == 0) 518 nat_hostmapdel(hm); 519 } 520 521 522 /* ------------------------------------------------------------------------ */ 523 /* Function: fix_outcksum */ 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 out. */ 529 /* ------------------------------------------------------------------------ */ 530 void fix_outcksum(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); 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_incksum */ 552 /* Returns: Nil */ 553 /* Parameters: sp(I) - location of 16bit checksum to update */ 554 /* n((I) - amount to adjust checksum by */ 555 /* */ 556 /* Adjusts the 16bit checksum by "n" for packets going in. */ 557 /* ------------------------------------------------------------------------ */ 558 void fix_incksum(sp, n) 559 u_short *sp; 560 u_32_t n; 561 { 562 u_short sumshort; 563 u_32_t sum1; 564 565 if (n == 0) 566 return; 567 568 sum1 = (~ntohs(*sp)) & 0xffff; 569 sum1 += ~(n) & 0xffff; 570 sum1 = (sum1 >> 16) + (sum1 & 0xffff); 571 /* Again */ 572 sum1 = (sum1 >> 16) + (sum1 & 0xffff); 573 sumshort = ~(u_short)sum1; 574 *(sp) = htons(sumshort); 575 } 576 577 578 /* ------------------------------------------------------------------------ */ 579 /* Function: fix_datacksum */ 580 /* Returns: Nil */ 581 /* Parameters: sp(I) - location of 16bit checksum to update */ 582 /* n((I) - amount to adjust checksum by */ 583 /* */ 584 /* Fix_datacksum is used *only* for the adjustments of checksums in the */ 585 /* data section of an IP packet. */ 586 /* */ 587 /* The only situation in which you need to do this is when NAT'ing an */ 588 /* ICMP error message. Such a message, contains in its body the IP header */ 589 /* of the original IP packet, that causes the error. */ 590 /* */ 591 /* You can't use fix_incksum or fix_outcksum in that case, because for the */ 592 /* kernel the data section of the ICMP error is just data, and no special */ 593 /* processing like hardware cksum or ntohs processing have been done by the */ 594 /* kernel on the data section. */ 595 /* ------------------------------------------------------------------------ */ 596 void fix_datacksum(sp, n) 597 u_short *sp; 598 u_32_t n; 599 { 600 u_short sumshort; 601 u_32_t sum1; 602 603 if (n == 0) 604 return; 605 606 sum1 = (~ntohs(*sp)) & 0xffff; 607 sum1 += (n); 608 sum1 = (sum1 >> 16) + (sum1 & 0xffff); 609 /* Again */ 610 sum1 = (sum1 >> 16) + (sum1 & 0xffff); 611 sumshort = ~(u_short)sum1; 612 *(sp) = htons(sumshort); 613 } 614 615 616 /* ------------------------------------------------------------------------ */ 617 /* Function: fr_nat_ioctl */ 618 /* Returns: int - 0 == success, != 0 == failure */ 619 /* Parameters: data(I) - pointer to ioctl data */ 620 /* cmd(I) - ioctl command integer */ 621 /* mode(I) - file mode bits used with open */ 622 /* */ 623 /* Processes an ioctl call made to operate on the IP Filter NAT device. */ 624 /* ------------------------------------------------------------------------ */ 625 int fr_nat_ioctl(data, cmd, mode, uid, ctx, ifs) 626 ioctlcmd_t cmd; 627 caddr_t data; 628 int mode, uid; 629 void *ctx; 630 ipf_stack_t *ifs; 631 { 632 ipnat_t *nat, *nt, *n = NULL, **np = NULL; 633 int error = 0, ret, arg, getlock; 634 ipnat_t natd; 635 636 #if (BSD >= 199306) && defined(_KERNEL) 637 if ((securelevel >= 2) && (mode & FWRITE)) 638 return EPERM; 639 #endif 640 641 #if defined(__osf__) && defined(_KERNEL) 642 getlock = 0; 643 #else 644 getlock = (mode & NAT_LOCKHELD) ? 0 : 1; 645 #endif 646 647 nat = NULL; /* XXX gcc -Wuninitialized */ 648 if (cmd == (ioctlcmd_t)SIOCADNAT) { 649 KMALLOC(nt, ipnat_t *); 650 } else { 651 nt = NULL; 652 } 653 654 if ((cmd == (ioctlcmd_t)SIOCADNAT) || (cmd == (ioctlcmd_t)SIOCRMNAT)) { 655 if (mode & NAT_SYSSPACE) { 656 bcopy(data, (char *)&natd, sizeof(natd)); 657 error = 0; 658 } else { 659 error = fr_inobj(data, &natd, IPFOBJ_IPNAT); 660 } 661 662 } else if (cmd == (ioctlcmd_t)SIOCIPFFL) { /* SIOCFLNAT & SIOCCNATL */ 663 BCOPYIN(data, &arg, sizeof(arg)); 664 } 665 666 if (error != 0) 667 goto done; 668 669 /* 670 * For add/delete, look to see if the NAT entry is already present 671 */ 672 if ((cmd == (ioctlcmd_t)SIOCADNAT) || (cmd == (ioctlcmd_t)SIOCRMNAT)) { 673 nat = &natd; 674 if (nat->in_v == 0) /* For backward compat. */ 675 nat->in_v = 4; 676 nat->in_flags &= IPN_USERFLAGS; 677 if ((nat->in_redir & NAT_MAPBLK) == 0) { 678 if ((nat->in_flags & IPN_SPLIT) == 0) 679 nat->in_inip &= nat->in_inmsk; 680 if ((nat->in_flags & IPN_IPRANGE) == 0) 681 nat->in_outip &= nat->in_outmsk; 682 } 683 MUTEX_ENTER(&ifs->ifs_ipf_natio); 684 for (np = &ifs->ifs_nat_list; ((n = *np) != NULL); 685 np = &n->in_next) 686 if (!bcmp((char *)&nat->in_flags, (char *)&n->in_flags, 687 IPN_CMPSIZ)) 688 break; 689 } 690 691 switch (cmd) 692 { 693 case SIOCGENITER : 694 { 695 ipfgeniter_t iter; 696 ipftoken_t *token; 697 698 error = fr_inobj(data, &iter, IPFOBJ_GENITER); 699 if (error != 0) 700 break; 701 702 token = ipf_findtoken(iter.igi_type, uid, ctx, ifs); 703 if (token != NULL) 704 error = nat_iterator(token, &iter, ifs); 705 else 706 error = ESRCH; 707 RWLOCK_EXIT(&ifs->ifs_ipf_tokens); 708 break; 709 } 710 #ifdef IPFILTER_LOG 711 case SIOCIPFFB : 712 { 713 int tmp; 714 715 if (!(mode & FWRITE)) 716 error = EPERM; 717 else { 718 tmp = ipflog_clear(IPL_LOGNAT, ifs); 719 BCOPYOUT((char *)&tmp, (char *)data, sizeof(tmp)); 720 } 721 break; 722 } 723 case SIOCSETLG : 724 if (!(mode & FWRITE)) 725 error = EPERM; 726 else { 727 BCOPYIN((char *)data, 728 (char *)&ifs->ifs_nat_logging, 729 sizeof(ifs->ifs_nat_logging)); 730 } 731 break; 732 case SIOCGETLG : 733 BCOPYOUT((char *)&ifs->ifs_nat_logging, (char *)data, 734 sizeof(ifs->ifs_nat_logging)); 735 break; 736 case FIONREAD : 737 arg = ifs->ifs_iplused[IPL_LOGNAT]; 738 BCOPYOUT(&arg, data, sizeof(arg)); 739 break; 740 #endif 741 case SIOCADNAT : 742 if (!(mode & FWRITE)) { 743 error = EPERM; 744 } else if (n != NULL) { 745 error = EEXIST; 746 } else if (nt == NULL) { 747 error = ENOMEM; 748 } 749 if (error != 0) { 750 MUTEX_EXIT(&ifs->ifs_ipf_natio); 751 break; 752 } 753 bcopy((char *)nat, (char *)nt, sizeof(*n)); 754 error = nat_siocaddnat(nt, np, getlock, ifs); 755 MUTEX_EXIT(&ifs->ifs_ipf_natio); 756 if (error == 0) 757 nt = NULL; 758 break; 759 case SIOCRMNAT : 760 if (!(mode & FWRITE)) { 761 error = EPERM; 762 n = NULL; 763 } else if (n == NULL) { 764 error = ESRCH; 765 } 766 767 if (error != 0) { 768 MUTEX_EXIT(&ifs->ifs_ipf_natio); 769 break; 770 } 771 nat_siocdelnat(n, np, getlock, ifs); 772 773 MUTEX_EXIT(&ifs->ifs_ipf_natio); 774 n = NULL; 775 break; 776 case SIOCGNATS : 777 ifs->ifs_nat_stats.ns_table[0] = ifs->ifs_nat_table[0]; 778 ifs->ifs_nat_stats.ns_table[1] = ifs->ifs_nat_table[1]; 779 ifs->ifs_nat_stats.ns_list = ifs->ifs_nat_list; 780 ifs->ifs_nat_stats.ns_maptable = ifs->ifs_maptable; 781 ifs->ifs_nat_stats.ns_maplist = ifs->ifs_ipf_hm_maplist; 782 ifs->ifs_nat_stats.ns_nattab_max = ifs->ifs_ipf_nattable_max; 783 ifs->ifs_nat_stats.ns_nattab_sz = ifs->ifs_ipf_nattable_sz; 784 ifs->ifs_nat_stats.ns_rultab_sz = ifs->ifs_ipf_natrules_sz; 785 ifs->ifs_nat_stats.ns_rdrtab_sz = ifs->ifs_ipf_rdrrules_sz; 786 ifs->ifs_nat_stats.ns_hostmap_sz = ifs->ifs_ipf_hostmap_sz; 787 ifs->ifs_nat_stats.ns_instances = ifs->ifs_nat_instances; 788 ifs->ifs_nat_stats.ns_apslist = ifs->ifs_ap_sess_list; 789 error = fr_outobj(data, &ifs->ifs_nat_stats, IPFOBJ_NATSTAT); 790 break; 791 case SIOCGNATL : 792 { 793 natlookup_t nl; 794 795 if (getlock) { 796 READ_ENTER(&ifs->ifs_ipf_nat); 797 } 798 error = fr_inobj(data, &nl, IPFOBJ_NATLOOKUP); 799 if (error == 0) { 800 if (nat_lookupredir(&nl, ifs) != NULL) { 801 error = fr_outobj(data, &nl, IPFOBJ_NATLOOKUP); 802 } else { 803 error = ESRCH; 804 } 805 } 806 if (getlock) { 807 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 808 } 809 break; 810 } 811 case SIOCIPFFL : /* old SIOCFLNAT & SIOCCNATL */ 812 if (!(mode & FWRITE)) { 813 error = EPERM; 814 break; 815 } 816 if (getlock) { 817 WRITE_ENTER(&ifs->ifs_ipf_nat); 818 } 819 error = 0; 820 if (arg == 0) 821 ret = nat_flushtable(ifs); 822 else if (arg == 1) 823 ret = nat_clearlist(ifs); 824 else if (arg >= 2 && arg <= 4) 825 ret = nat_extraflush(arg - 2, ifs); 826 else 827 error = EINVAL; 828 if (getlock) { 829 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 830 } 831 if (error == 0) { 832 BCOPYOUT(&ret, data, sizeof(ret)); 833 } 834 break; 835 case SIOCPROXY : 836 error = appr_ioctl(data, cmd, mode, ifs); 837 break; 838 case SIOCSTLCK : 839 if (!(mode & FWRITE)) { 840 error = EPERM; 841 } else { 842 fr_lock(data, &ifs->ifs_fr_nat_lock); 843 } 844 break; 845 case SIOCSTPUT : 846 if ((mode & FWRITE) != 0) { 847 error = fr_natputent(data, getlock, ifs); 848 } else { 849 error = EACCES; 850 } 851 break; 852 case SIOCSTGSZ : 853 if (ifs->ifs_fr_nat_lock) { 854 if (getlock) { 855 READ_ENTER(&ifs->ifs_ipf_nat); 856 } 857 error = fr_natgetsz(data, ifs); 858 if (getlock) { 859 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 860 } 861 } else 862 error = EACCES; 863 break; 864 case SIOCSTGET : 865 if (ifs->ifs_fr_nat_lock) { 866 if (getlock) { 867 READ_ENTER(&ifs->ifs_ipf_nat); 868 } 869 error = fr_natgetent(data, ifs); 870 if (getlock) { 871 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 872 } 873 } else 874 error = EACCES; 875 break; 876 case SIOCIPFDELTOK : 877 (void) BCOPYIN((caddr_t)data, (caddr_t)&arg, sizeof(arg)); 878 error = ipf_deltoken(arg, uid, ctx, ifs); 879 break; 880 default : 881 error = EINVAL; 882 break; 883 } 884 done: 885 if (nt) 886 KFREE(nt); 887 return error; 888 } 889 890 891 /* ------------------------------------------------------------------------ */ 892 /* Function: nat_siocaddnat */ 893 /* Returns: int - 0 == success, != 0 == failure */ 894 /* Parameters: n(I) - pointer to new NAT rule */ 895 /* np(I) - pointer to where to insert new NAT rule */ 896 /* getlock(I) - flag indicating if lock on ipf_nat is held */ 897 /* Mutex Locks: ipf_natio */ 898 /* */ 899 /* Handle SIOCADNAT. Resolve and calculate details inside the NAT rule */ 900 /* from information passed to the kernel, then add it to the appropriate */ 901 /* NAT rule table(s). */ 902 /* ------------------------------------------------------------------------ */ 903 static int nat_siocaddnat(n, np, getlock, ifs) 904 ipnat_t *n, **np; 905 int getlock; 906 ipf_stack_t *ifs; 907 { 908 int error = 0, i, j; 909 910 if (nat_resolverule(n, ifs) != 0) 911 return ENOENT; 912 913 if ((n->in_age[0] == 0) && (n->in_age[1] != 0)) 914 return EINVAL; 915 916 n->in_use = 0; 917 if (n->in_redir & NAT_MAPBLK) 918 n->in_space = USABLE_PORTS * ~ntohl(n->in_outmsk); 919 else if (n->in_flags & IPN_AUTOPORTMAP) 920 n->in_space = USABLE_PORTS * ~ntohl(n->in_inmsk); 921 else if (n->in_flags & IPN_IPRANGE) 922 n->in_space = ntohl(n->in_outmsk) - ntohl(n->in_outip); 923 else if (n->in_flags & IPN_SPLIT) 924 n->in_space = 2; 925 else if (n->in_outmsk != 0) 926 n->in_space = ~ntohl(n->in_outmsk); 927 else 928 n->in_space = 1; 929 930 /* 931 * Calculate the number of valid IP addresses in the output 932 * mapping range. In all cases, the range is inclusive of 933 * the start and ending IP addresses. 934 * If to a CIDR address, lose 2: broadcast + network address 935 * (so subtract 1) 936 * If to a range, add one. 937 * If to a single IP address, set to 1. 938 */ 939 if (n->in_space) { 940 if ((n->in_flags & IPN_IPRANGE) != 0) 941 n->in_space += 1; 942 else 943 n->in_space -= 1; 944 } else 945 n->in_space = 1; 946 947 if ((n->in_outmsk != 0xffffffff) && (n->in_outmsk != 0) && 948 ((n->in_flags & (IPN_IPRANGE|IPN_SPLIT)) == 0)) 949 n->in_nip = ntohl(n->in_outip) + 1; 950 else if ((n->in_flags & IPN_SPLIT) && 951 (n->in_redir & NAT_REDIRECT)) 952 n->in_nip = ntohl(n->in_inip); 953 else 954 n->in_nip = ntohl(n->in_outip); 955 if (n->in_redir & NAT_MAP) { 956 n->in_pnext = ntohs(n->in_pmin); 957 /* 958 * Multiply by the number of ports made available. 959 */ 960 if (ntohs(n->in_pmax) >= ntohs(n->in_pmin)) { 961 n->in_space *= (ntohs(n->in_pmax) - 962 ntohs(n->in_pmin) + 1); 963 /* 964 * Because two different sources can map to 965 * different destinations but use the same 966 * local IP#/port #. 967 * If the result is smaller than in_space, then 968 * we may have wrapped around 32bits. 969 */ 970 i = n->in_inmsk; 971 if ((i != 0) && (i != 0xffffffff)) { 972 j = n->in_space * (~ntohl(i) + 1); 973 if (j >= n->in_space) 974 n->in_space = j; 975 else 976 n->in_space = 0xffffffff; 977 } 978 } 979 /* 980 * If no protocol is specified, multiple by 256 to allow for 981 * at least one IP:IP mapping per protocol. 982 */ 983 if ((n->in_flags & IPN_TCPUDPICMP) == 0) { 984 j = n->in_space * 256; 985 if (j >= n->in_space) 986 n->in_space = j; 987 else 988 n->in_space = 0xffffffff; 989 } 990 } 991 992 /* Otherwise, these fields are preset */ 993 994 if (getlock) { 995 WRITE_ENTER(&ifs->ifs_ipf_nat); 996 } 997 n->in_next = NULL; 998 *np = n; 999 1000 if (n->in_age[0] != 0) 1001 n->in_tqehead[0] = fr_addtimeoutqueue(&ifs->ifs_nat_utqe, 1002 n->in_age[0], ifs); 1003 1004 if (n->in_age[1] != 0) 1005 n->in_tqehead[1] = fr_addtimeoutqueue(&ifs->ifs_nat_utqe, 1006 n->in_age[1], ifs); 1007 1008 if (n->in_redir & NAT_REDIRECT) { 1009 n->in_flags &= ~IPN_NOTDST; 1010 nat_addrdr(n, ifs); 1011 } 1012 if (n->in_redir & (NAT_MAP|NAT_MAPBLK)) { 1013 n->in_flags &= ~IPN_NOTSRC; 1014 nat_addnat(n, ifs); 1015 } 1016 n = NULL; 1017 ifs->ifs_nat_stats.ns_rules++; 1018 if (getlock) { 1019 RWLOCK_EXIT(&ifs->ifs_ipf_nat); /* WRITE */ 1020 } 1021 1022 return error; 1023 } 1024 1025 1026 /* ------------------------------------------------------------------------ */ 1027 /* Function: nat_resolvrule */ 1028 /* Returns: int - 0 == success, -1 == failure */ 1029 /* Parameters: n(I) - pointer to NAT rule */ 1030 /* */ 1031 /* Resolve some of the details inside the NAT rule. Includes resolving */ 1032 /* any specified interfaces and proxy labels, and determines whether or not */ 1033 /* all proxy labels are correctly specified. */ 1034 /* */ 1035 /* Called by nat_siocaddnat() (SIOCADNAT) and fr_natputent (SIOCSTPUT). */ 1036 /* ------------------------------------------------------------------------ */ 1037 static int nat_resolverule(n, ifs) 1038 ipnat_t *n; 1039 ipf_stack_t *ifs; 1040 { 1041 n->in_ifnames[0][LIFNAMSIZ - 1] = '\0'; 1042 n->in_ifps[0] = fr_resolvenic(n->in_ifnames[0], 4, ifs); 1043 1044 n->in_ifnames[1][LIFNAMSIZ - 1] = '\0'; 1045 if (n->in_ifnames[1][0] == '\0') { 1046 (void) strncpy(n->in_ifnames[1], n->in_ifnames[0], LIFNAMSIZ); 1047 n->in_ifps[1] = n->in_ifps[0]; 1048 } else { 1049 n->in_ifps[1] = fr_resolvenic(n->in_ifnames[1], 4, ifs); 1050 } 1051 1052 if (n->in_plabel[0] != '\0') { 1053 n->in_apr = appr_lookup(n->in_p, n->in_plabel, ifs); 1054 if (n->in_apr == NULL) 1055 return -1; 1056 } 1057 return 0; 1058 } 1059 1060 1061 /* ------------------------------------------------------------------------ */ 1062 /* Function: nat_siocdelnat */ 1063 /* Returns: int - 0 == success, != 0 == failure */ 1064 /* Parameters: n(I) - pointer to new NAT rule */ 1065 /* np(I) - pointer to where to insert new NAT rule */ 1066 /* getlock(I) - flag indicating if lock on ipf_nat is held */ 1067 /* Mutex Locks: ipf_natio */ 1068 /* */ 1069 /* Handle SIOCADNAT. Resolve and calculate details inside the NAT rule */ 1070 /* from information passed to the kernel, then add it to the appropriate */ 1071 /* NAT rule table(s). */ 1072 /* ------------------------------------------------------------------------ */ 1073 static void nat_siocdelnat(n, np, getlock, ifs) 1074 ipnat_t *n, **np; 1075 int getlock; 1076 ipf_stack_t *ifs; 1077 { 1078 if (getlock) { 1079 WRITE_ENTER(&ifs->ifs_ipf_nat); 1080 } 1081 if (n->in_redir & NAT_REDIRECT) 1082 nat_delrdr(n); 1083 if (n->in_redir & (NAT_MAPBLK|NAT_MAP)) 1084 nat_delnat(n); 1085 if (ifs->ifs_nat_list == NULL) { 1086 ifs->ifs_nat_masks = 0; 1087 ifs->ifs_rdr_masks = 0; 1088 } 1089 1090 if (n->in_tqehead[0] != NULL) { 1091 if (fr_deletetimeoutqueue(n->in_tqehead[0]) == 0) { 1092 fr_freetimeoutqueue(n->in_tqehead[0], ifs); 1093 } 1094 } 1095 1096 if (n->in_tqehead[1] != NULL) { 1097 if (fr_deletetimeoutqueue(n->in_tqehead[1]) == 0) { 1098 fr_freetimeoutqueue(n->in_tqehead[1], ifs); 1099 } 1100 } 1101 1102 *np = n->in_next; 1103 1104 if (n->in_use == 0) { 1105 if (n->in_apr) 1106 appr_free(n->in_apr); 1107 KFREE(n); 1108 ifs->ifs_nat_stats.ns_rules--; 1109 } else { 1110 n->in_flags |= IPN_DELETE; 1111 n->in_next = NULL; 1112 } 1113 if (getlock) { 1114 RWLOCK_EXIT(&ifs->ifs_ipf_nat); /* READ/WRITE */ 1115 } 1116 } 1117 1118 1119 /* ------------------------------------------------------------------------ */ 1120 /* Function: fr_natgetsz */ 1121 /* Returns: int - 0 == success, != 0 is the error value. */ 1122 /* Parameters: data(I) - pointer to natget structure with kernel pointer */ 1123 /* get the size of. */ 1124 /* */ 1125 /* Handle SIOCSTGSZ. */ 1126 /* Return the size of the nat list entry to be copied back to user space. */ 1127 /* The size of the entry is stored in the ng_sz field and the enture natget */ 1128 /* structure is copied back to the user. */ 1129 /* ------------------------------------------------------------------------ */ 1130 static int fr_natgetsz(data, ifs) 1131 caddr_t data; 1132 ipf_stack_t *ifs; 1133 { 1134 ap_session_t *aps; 1135 nat_t *nat, *n; 1136 natget_t ng; 1137 1138 BCOPYIN(data, &ng, sizeof(ng)); 1139 1140 nat = ng.ng_ptr; 1141 if (!nat) { 1142 nat = ifs->ifs_nat_instances; 1143 ng.ng_sz = 0; 1144 /* 1145 * Empty list so the size returned is 0. Simple. 1146 */ 1147 if (nat == NULL) { 1148 BCOPYOUT(&ng, data, sizeof(ng)); 1149 return 0; 1150 } 1151 } else { 1152 /* 1153 * Make sure the pointer we're copying from exists in the 1154 * current list of entries. Security precaution to prevent 1155 * copying of random kernel data. 1156 */ 1157 for (n = ifs->ifs_nat_instances; n; n = n->nat_next) 1158 if (n == nat) 1159 break; 1160 if (!n) 1161 return ESRCH; 1162 } 1163 1164 /* 1165 * Incluse any space required for proxy data structures. 1166 */ 1167 ng.ng_sz = sizeof(nat_save_t); 1168 aps = nat->nat_aps; 1169 if (aps != NULL) { 1170 ng.ng_sz += sizeof(ap_session_t) - 4; 1171 if (aps->aps_data != 0) 1172 ng.ng_sz += aps->aps_psiz; 1173 } 1174 1175 BCOPYOUT(&ng, data, sizeof(ng)); 1176 return 0; 1177 } 1178 1179 1180 /* ------------------------------------------------------------------------ */ 1181 /* Function: fr_natgetent */ 1182 /* Returns: int - 0 == success, != 0 is the error value. */ 1183 /* Parameters: data(I) - pointer to natget structure with kernel pointer */ 1184 /* to NAT structure to copy out. */ 1185 /* */ 1186 /* Handle SIOCSTGET. */ 1187 /* Copies out NAT entry to user space. Any additional data held for a */ 1188 /* proxy is also copied, as to is the NAT rule which was responsible for it */ 1189 /* ------------------------------------------------------------------------ */ 1190 static int fr_natgetent(data, ifs) 1191 caddr_t data; 1192 ipf_stack_t *ifs; 1193 { 1194 int error, outsize; 1195 ap_session_t *aps; 1196 nat_save_t *ipn, ipns; 1197 nat_t *n, *nat; 1198 1199 error = fr_inobj(data, &ipns, IPFOBJ_NATSAVE); 1200 if (error != 0) 1201 return error; 1202 1203 if ((ipns.ipn_dsize < sizeof(ipns)) || (ipns.ipn_dsize > 81920)) 1204 return EINVAL; 1205 1206 KMALLOCS(ipn, nat_save_t *, ipns.ipn_dsize); 1207 if (ipn == NULL) 1208 return ENOMEM; 1209 1210 ipn->ipn_dsize = ipns.ipn_dsize; 1211 nat = ipns.ipn_next; 1212 if (nat == NULL) { 1213 nat = ifs->ifs_nat_instances; 1214 if (nat == NULL) { 1215 if (ifs->ifs_nat_instances == NULL) 1216 error = ENOENT; 1217 goto finished; 1218 } 1219 } else { 1220 /* 1221 * Make sure the pointer we're copying from exists in the 1222 * current list of entries. Security precaution to prevent 1223 * copying of random kernel data. 1224 */ 1225 for (n = ifs->ifs_nat_instances; n; n = n->nat_next) 1226 if (n == nat) 1227 break; 1228 if (n == NULL) { 1229 error = ESRCH; 1230 goto finished; 1231 } 1232 } 1233 ipn->ipn_next = nat->nat_next; 1234 1235 /* 1236 * Copy the NAT structure. 1237 */ 1238 bcopy((char *)nat, &ipn->ipn_nat, sizeof(*nat)); 1239 1240 /* 1241 * If we have a pointer to the NAT rule it belongs to, save that too. 1242 */ 1243 if (nat->nat_ptr != NULL) 1244 bcopy((char *)nat->nat_ptr, (char *)&ipn->ipn_ipnat, 1245 sizeof(ipn->ipn_ipnat)); 1246 1247 /* 1248 * If we also know the NAT entry has an associated filter rule, 1249 * save that too. 1250 */ 1251 if (nat->nat_fr != NULL) 1252 bcopy((char *)nat->nat_fr, (char *)&ipn->ipn_fr, 1253 sizeof(ipn->ipn_fr)); 1254 1255 /* 1256 * Last but not least, if there is an application proxy session set 1257 * up for this NAT entry, then copy that out too, including any 1258 * private data saved along side it by the proxy. 1259 */ 1260 aps = nat->nat_aps; 1261 outsize = ipn->ipn_dsize - sizeof(*ipn) + sizeof(ipn->ipn_data); 1262 if (aps != NULL) { 1263 char *s; 1264 1265 if (outsize < sizeof(*aps)) { 1266 error = ENOBUFS; 1267 goto finished; 1268 } 1269 1270 s = ipn->ipn_data; 1271 bcopy((char *)aps, s, sizeof(*aps)); 1272 s += sizeof(*aps); 1273 outsize -= sizeof(*aps); 1274 if ((aps->aps_data != NULL) && (outsize >= aps->aps_psiz)) 1275 bcopy(aps->aps_data, s, aps->aps_psiz); 1276 else 1277 error = ENOBUFS; 1278 } 1279 if (error == 0) { 1280 error = fr_outobjsz(data, ipn, IPFOBJ_NATSAVE, ipns.ipn_dsize); 1281 } 1282 1283 finished: 1284 if (ipn != NULL) { 1285 KFREES(ipn, ipns.ipn_dsize); 1286 } 1287 return error; 1288 } 1289 1290 1291 /* ------------------------------------------------------------------------ */ 1292 /* Function: fr_natputent */ 1293 /* Returns: int - 0 == success, != 0 is the error value. */ 1294 /* Parameters: data(I) - pointer to natget structure with NAT */ 1295 /* structure information to load into the kernel */ 1296 /* getlock(I) - flag indicating whether or not a write lock */ 1297 /* on ipf_nat is already held. */ 1298 /* */ 1299 /* Handle SIOCSTPUT. */ 1300 /* Loads a NAT table entry from user space, including a NAT rule, proxy and */ 1301 /* firewall rule data structures, if pointers to them indicate so. */ 1302 /* ------------------------------------------------------------------------ */ 1303 static int fr_natputent(data, getlock, ifs) 1304 caddr_t data; 1305 int getlock; 1306 ipf_stack_t *ifs; 1307 { 1308 nat_save_t ipn, *ipnn; 1309 ap_session_t *aps; 1310 nat_t *n, *nat; 1311 frentry_t *fr; 1312 fr_info_t fin; 1313 ipnat_t *in; 1314 int error; 1315 1316 error = fr_inobj(data, &ipn, IPFOBJ_NATSAVE); 1317 if (error != 0) 1318 return error; 1319 1320 /* 1321 * Trigger automatic call to nat_extraflush() if the 1322 * table has reached capcity specified by hi watermark. 1323 */ 1324 if (NAT_TAB_WATER_LEVEL(ifs) > ifs->ifs_nat_flush_lvl_hi) 1325 ifs->ifs_nat_doflush = 1; 1326 1327 /* 1328 * Initialise early because of code at junkput label. 1329 */ 1330 in = NULL; 1331 aps = NULL; 1332 nat = NULL; 1333 ipnn = NULL; 1334 1335 /* 1336 * New entry, copy in the rest of the NAT entry if it's size is more 1337 * than just the nat_t structure. 1338 */ 1339 fr = NULL; 1340 if (ipn.ipn_dsize > sizeof(ipn)) { 1341 if (ipn.ipn_dsize > 81920) { 1342 error = ENOMEM; 1343 goto junkput; 1344 } 1345 1346 KMALLOCS(ipnn, nat_save_t *, ipn.ipn_dsize); 1347 if (ipnn == NULL) 1348 return ENOMEM; 1349 1350 error = fr_inobjsz(data, ipnn, IPFOBJ_NATSAVE, ipn.ipn_dsize); 1351 if (error != 0) { 1352 error = EFAULT; 1353 goto junkput; 1354 } 1355 } else 1356 ipnn = &ipn; 1357 1358 KMALLOC(nat, nat_t *); 1359 if (nat == NULL) { 1360 error = ENOMEM; 1361 goto junkput; 1362 } 1363 1364 bcopy((char *)&ipnn->ipn_nat, (char *)nat, sizeof(*nat)); 1365 /* 1366 * Initialize all these so that nat_delete() doesn't cause a crash. 1367 */ 1368 bzero((char *)nat, offsetof(struct nat, nat_tqe)); 1369 nat->nat_tqe.tqe_pnext = NULL; 1370 nat->nat_tqe.tqe_next = NULL; 1371 nat->nat_tqe.tqe_ifq = NULL; 1372 nat->nat_tqe.tqe_parent = nat; 1373 1374 /* 1375 * Restore the rule associated with this nat session 1376 */ 1377 in = ipnn->ipn_nat.nat_ptr; 1378 if (in != NULL) { 1379 KMALLOC(in, ipnat_t *); 1380 nat->nat_ptr = in; 1381 if (in == NULL) { 1382 error = ENOMEM; 1383 goto junkput; 1384 } 1385 bzero((char *)in, offsetof(struct ipnat, in_next6)); 1386 bcopy((char *)&ipnn->ipn_ipnat, (char *)in, sizeof(*in)); 1387 in->in_use = 1; 1388 in->in_flags |= IPN_DELETE; 1389 1390 ATOMIC_INC(ifs->ifs_nat_stats.ns_rules); 1391 1392 if (nat_resolverule(in, ifs) != 0) { 1393 error = ESRCH; 1394 goto junkput; 1395 } 1396 } 1397 1398 /* 1399 * Check that the NAT entry doesn't already exist in the kernel. 1400 */ 1401 bzero((char *)&fin, sizeof(fin)); 1402 fin.fin_p = nat->nat_p; 1403 fin.fin_ifs = ifs; 1404 if (nat->nat_dir == NAT_OUTBOUND) { 1405 fin.fin_data[0] = ntohs(nat->nat_oport); 1406 fin.fin_data[1] = ntohs(nat->nat_outport); 1407 fin.fin_ifp = nat->nat_ifps[0]; 1408 if (getlock) { 1409 READ_ENTER(&ifs->ifs_ipf_nat); 1410 } 1411 n = nat_inlookup(&fin, nat->nat_flags, fin.fin_p, 1412 nat->nat_oip, nat->nat_outip); 1413 if (getlock) { 1414 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 1415 } 1416 if (n != NULL) { 1417 error = EEXIST; 1418 goto junkput; 1419 } 1420 } else if (nat->nat_dir == NAT_INBOUND) { 1421 fin.fin_data[0] = ntohs(nat->nat_inport); 1422 fin.fin_data[1] = ntohs(nat->nat_oport); 1423 fin.fin_ifp = nat->nat_ifps[1]; 1424 if (getlock) { 1425 READ_ENTER(&ifs->ifs_ipf_nat); 1426 } 1427 n = nat_outlookup(&fin, nat->nat_flags, fin.fin_p, 1428 nat->nat_inip, nat->nat_oip); 1429 if (getlock) { 1430 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 1431 } 1432 if (n != NULL) { 1433 error = EEXIST; 1434 goto junkput; 1435 } 1436 } else { 1437 error = EINVAL; 1438 goto junkput; 1439 } 1440 1441 /* 1442 * Restore ap_session_t structure. Include the private data allocated 1443 * if it was there. 1444 */ 1445 aps = nat->nat_aps; 1446 if (aps != NULL) { 1447 KMALLOC(aps, ap_session_t *); 1448 nat->nat_aps = aps; 1449 if (aps == NULL) { 1450 error = ENOMEM; 1451 goto junkput; 1452 } 1453 bcopy(ipnn->ipn_data, (char *)aps, sizeof(*aps)); 1454 if (in != NULL) 1455 aps->aps_apr = in->in_apr; 1456 else 1457 aps->aps_apr = NULL; 1458 if (aps->aps_psiz != 0) { 1459 if (aps->aps_psiz > 81920) { 1460 error = ENOMEM; 1461 goto junkput; 1462 } 1463 KMALLOCS(aps->aps_data, void *, aps->aps_psiz); 1464 if (aps->aps_data == NULL) { 1465 error = ENOMEM; 1466 goto junkput; 1467 } 1468 bcopy(ipnn->ipn_data + sizeof(*aps), aps->aps_data, 1469 aps->aps_psiz); 1470 } else { 1471 aps->aps_psiz = 0; 1472 aps->aps_data = NULL; 1473 } 1474 } 1475 1476 /* 1477 * If there was a filtering rule associated with this entry then 1478 * build up a new one. 1479 */ 1480 fr = nat->nat_fr; 1481 if (fr != NULL) { 1482 if ((nat->nat_flags & SI_NEWFR) != 0) { 1483 KMALLOC(fr, frentry_t *); 1484 nat->nat_fr = fr; 1485 if (fr == NULL) { 1486 error = ENOMEM; 1487 goto junkput; 1488 } 1489 ipnn->ipn_nat.nat_fr = fr; 1490 (void) fr_outobj(data, ipnn, IPFOBJ_NATSAVE); 1491 bcopy((char *)&ipnn->ipn_fr, (char *)fr, sizeof(*fr)); 1492 1493 fr->fr_ref = 1; 1494 fr->fr_dsize = 0; 1495 fr->fr_data = NULL; 1496 fr->fr_type = FR_T_NONE; 1497 1498 MUTEX_NUKE(&fr->fr_lock); 1499 MUTEX_INIT(&fr->fr_lock, "nat-filter rule lock"); 1500 } else { 1501 if (getlock) { 1502 READ_ENTER(&ifs->ifs_ipf_nat); 1503 } 1504 for (n = ifs->ifs_nat_instances; n; n = n->nat_next) 1505 if (n->nat_fr == fr) 1506 break; 1507 1508 if (n != NULL) { 1509 MUTEX_ENTER(&fr->fr_lock); 1510 fr->fr_ref++; 1511 MUTEX_EXIT(&fr->fr_lock); 1512 } 1513 if (getlock) { 1514 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 1515 } 1516 if (!n) { 1517 error = ESRCH; 1518 goto junkput; 1519 } 1520 } 1521 } 1522 1523 if (ipnn != &ipn) { 1524 KFREES(ipnn, ipn.ipn_dsize); 1525 ipnn = NULL; 1526 } 1527 1528 if (getlock) { 1529 WRITE_ENTER(&ifs->ifs_ipf_nat); 1530 } 1531 error = nat_insert(nat, nat->nat_rev, ifs); 1532 if ((error == 0) && (aps != NULL)) { 1533 aps->aps_next = ifs->ifs_ap_sess_list; 1534 ifs->ifs_ap_sess_list = aps; 1535 } 1536 if (getlock) { 1537 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 1538 } 1539 1540 if (error == 0) 1541 return 0; 1542 1543 error = ENOMEM; 1544 1545 junkput: 1546 if (fr != NULL) 1547 (void) fr_derefrule(&fr, ifs); 1548 1549 if ((ipnn != NULL) && (ipnn != &ipn)) { 1550 KFREES(ipnn, ipn.ipn_dsize); 1551 } 1552 if (nat != NULL) { 1553 if (aps != NULL) { 1554 if (aps->aps_data != NULL) { 1555 KFREES(aps->aps_data, aps->aps_psiz); 1556 } 1557 KFREE(aps); 1558 } 1559 if (in != NULL) { 1560 if (in->in_apr) 1561 appr_free(in->in_apr); 1562 KFREE(in); 1563 } 1564 KFREE(nat); 1565 } 1566 return error; 1567 } 1568 1569 1570 /* ------------------------------------------------------------------------ */ 1571 /* Function: nat_delete */ 1572 /* Returns: Nil */ 1573 /* Parameters: natd(I) - pointer to NAT structure to delete */ 1574 /* logtype(I) - type of LOG record to create before deleting */ 1575 /* Write Lock: ipf_nat */ 1576 /* */ 1577 /* Delete a nat entry from the various lists and table. If NAT logging is */ 1578 /* enabled then generate a NAT log record for this event. */ 1579 /* ------------------------------------------------------------------------ */ 1580 static void nat_delete(nat, logtype, ifs) 1581 struct nat *nat; 1582 int logtype; 1583 ipf_stack_t *ifs; 1584 { 1585 struct ipnat *ipn; 1586 1587 if (logtype != 0 && ifs->ifs_nat_logging != 0) 1588 nat_log(nat, logtype, ifs); 1589 1590 MUTEX_ENTER(&ifs->ifs_ipf_nat_new); 1591 1592 /* 1593 * Take it as a general indication that all the pointers are set if 1594 * nat_pnext is set. 1595 */ 1596 if (nat->nat_pnext != NULL) { 1597 ifs->ifs_nat_stats.ns_bucketlen[0][nat->nat_hv[0]]--; 1598 ifs->ifs_nat_stats.ns_bucketlen[1][nat->nat_hv[1]]--; 1599 1600 *nat->nat_pnext = nat->nat_next; 1601 if (nat->nat_next != NULL) { 1602 nat->nat_next->nat_pnext = nat->nat_pnext; 1603 nat->nat_next = NULL; 1604 } 1605 nat->nat_pnext = NULL; 1606 1607 *nat->nat_phnext[0] = nat->nat_hnext[0]; 1608 if (nat->nat_hnext[0] != NULL) { 1609 nat->nat_hnext[0]->nat_phnext[0] = nat->nat_phnext[0]; 1610 nat->nat_hnext[0] = NULL; 1611 } 1612 nat->nat_phnext[0] = NULL; 1613 1614 *nat->nat_phnext[1] = nat->nat_hnext[1]; 1615 if (nat->nat_hnext[1] != NULL) { 1616 nat->nat_hnext[1]->nat_phnext[1] = nat->nat_phnext[1]; 1617 nat->nat_hnext[1] = NULL; 1618 } 1619 nat->nat_phnext[1] = NULL; 1620 1621 if ((nat->nat_flags & SI_WILDP) != 0) 1622 ifs->ifs_nat_stats.ns_wilds--; 1623 } 1624 1625 if (nat->nat_me != NULL) { 1626 *nat->nat_me = NULL; 1627 nat->nat_me = NULL; 1628 } 1629 1630 fr_deletequeueentry(&nat->nat_tqe); 1631 1632 nat->nat_ref--; 1633 if (nat->nat_ref > 0) { 1634 MUTEX_EXIT(&ifs->ifs_ipf_nat_new); 1635 return; 1636 } 1637 1638 #ifdef IPFILTER_SYNC 1639 if (nat->nat_sync) 1640 ipfsync_del(nat->nat_sync); 1641 #endif 1642 1643 if (nat->nat_fr != NULL) 1644 (void)fr_derefrule(&nat->nat_fr, ifs); 1645 1646 if (nat->nat_hm != NULL) 1647 nat_hostmapdel(nat->nat_hm); 1648 1649 /* 1650 * If there is an active reference from the nat entry to its parent 1651 * rule, decrement the rule's reference count and free it too if no 1652 * longer being used. 1653 */ 1654 ipn = nat->nat_ptr; 1655 if (ipn != NULL) { 1656 ipn->in_space++; 1657 ipn->in_use--; 1658 if (ipn->in_use == 0 && (ipn->in_flags & IPN_DELETE)) { 1659 if (ipn->in_apr) 1660 appr_free(ipn->in_apr); 1661 KFREE(ipn); 1662 ifs->ifs_nat_stats.ns_rules--; 1663 } 1664 } 1665 1666 MUTEX_DESTROY(&nat->nat_lock); 1667 1668 aps_free(nat->nat_aps, ifs); 1669 ifs->ifs_nat_stats.ns_inuse--; 1670 MUTEX_EXIT(&ifs->ifs_ipf_nat_new); 1671 1672 /* 1673 * If there's a fragment table entry too for this nat entry, then 1674 * dereference that as well. This is after nat_lock is released 1675 * because of Tru64. 1676 */ 1677 fr_forgetnat((void *)nat, ifs); 1678 1679 KFREE(nat); 1680 } 1681 1682 1683 /* ------------------------------------------------------------------------ */ 1684 /* Function: nat_flushtable */ 1685 /* Returns: int - number of NAT rules deleted */ 1686 /* Parameters: Nil */ 1687 /* */ 1688 /* Deletes all currently active NAT sessions. In deleting each NAT entry a */ 1689 /* log record should be emitted in nat_delete() if NAT logging is enabled. */ 1690 /* ------------------------------------------------------------------------ */ 1691 /* 1692 * nat_flushtable - clear the NAT table of all mapping entries. 1693 */ 1694 static int nat_flushtable(ifs) 1695 ipf_stack_t *ifs; 1696 { 1697 nat_t *nat; 1698 int j = 0; 1699 1700 /* 1701 * ALL NAT mappings deleted, so lets just make the deletions 1702 * quicker. 1703 */ 1704 if (ifs->ifs_nat_table[0] != NULL) 1705 bzero((char *)ifs->ifs_nat_table[0], 1706 sizeof(ifs->ifs_nat_table[0]) * ifs->ifs_ipf_nattable_sz); 1707 if (ifs->ifs_nat_table[1] != NULL) 1708 bzero((char *)ifs->ifs_nat_table[1], 1709 sizeof(ifs->ifs_nat_table[1]) * ifs->ifs_ipf_nattable_sz); 1710 1711 while ((nat = ifs->ifs_nat_instances) != NULL) { 1712 nat_delete(nat, NL_FLUSH, ifs); 1713 j++; 1714 } 1715 1716 ifs->ifs_nat_stats.ns_inuse = 0; 1717 return j; 1718 } 1719 1720 1721 /* ------------------------------------------------------------------------ */ 1722 /* Function: nat_clearlist */ 1723 /* Returns: int - number of NAT/RDR rules deleted */ 1724 /* Parameters: Nil */ 1725 /* */ 1726 /* Delete all rules in the current list of rules. There is nothing elegant */ 1727 /* about this cleanup: simply free all entries on the list of rules and */ 1728 /* clear out the tables used for hashed NAT rule lookups. */ 1729 /* ------------------------------------------------------------------------ */ 1730 static int nat_clearlist(ifs) 1731 ipf_stack_t *ifs; 1732 { 1733 ipnat_t *n, **np = &ifs->ifs_nat_list; 1734 int i = 0; 1735 1736 if (ifs->ifs_nat_rules != NULL) 1737 bzero((char *)ifs->ifs_nat_rules, 1738 sizeof(*ifs->ifs_nat_rules) * ifs->ifs_ipf_natrules_sz); 1739 if (ifs->ifs_rdr_rules != NULL) 1740 bzero((char *)ifs->ifs_rdr_rules, 1741 sizeof(*ifs->ifs_rdr_rules) * ifs->ifs_ipf_rdrrules_sz); 1742 1743 while ((n = *np) != NULL) { 1744 *np = n->in_next; 1745 if (n->in_use == 0) { 1746 if (n->in_apr != NULL) 1747 appr_free(n->in_apr); 1748 KFREE(n); 1749 ifs->ifs_nat_stats.ns_rules--; 1750 } else { 1751 n->in_flags |= IPN_DELETE; 1752 n->in_next = NULL; 1753 } 1754 i++; 1755 } 1756 ifs->ifs_nat_masks = 0; 1757 ifs->ifs_rdr_masks = 0; 1758 return i; 1759 } 1760 1761 1762 /* ------------------------------------------------------------------------ */ 1763 /* Function: nat_newmap */ 1764 /* Returns: int - -1 == error, 0 == success */ 1765 /* Parameters: fin(I) - pointer to packet information */ 1766 /* nat(I) - pointer to NAT entry */ 1767 /* ni(I) - pointer to structure with misc. information needed */ 1768 /* to create new NAT entry. */ 1769 /* */ 1770 /* Given an empty NAT structure, populate it with new information about a */ 1771 /* new NAT session, as defined by the matching NAT rule. */ 1772 /* ni.nai_ip is passed in uninitialised and must be set, in host byte order,*/ 1773 /* to the new IP address for the translation. */ 1774 /* ------------------------------------------------------------------------ */ 1775 static INLINE int nat_newmap(fin, nat, ni) 1776 fr_info_t *fin; 1777 nat_t *nat; 1778 natinfo_t *ni; 1779 { 1780 u_short st_port, dport, sport, port, sp, dp; 1781 struct in_addr in, inb; 1782 hostmap_t *hm; 1783 u_32_t flags; 1784 u_32_t st_ip; 1785 ipnat_t *np; 1786 nat_t *natl; 1787 int l; 1788 ipf_stack_t *ifs = fin->fin_ifs; 1789 1790 /* 1791 * If it's an outbound packet which doesn't match any existing 1792 * record, then create a new port 1793 */ 1794 l = 0; 1795 hm = NULL; 1796 np = ni->nai_np; 1797 st_ip = np->in_nip; 1798 st_port = np->in_pnext; 1799 flags = ni->nai_flags; 1800 sport = ni->nai_sport; 1801 dport = ni->nai_dport; 1802 1803 /* 1804 * Do a loop until we either run out of entries to try or we find 1805 * a NAT mapping that isn't currently being used. This is done 1806 * because the change to the source is not (usually) being fixed. 1807 */ 1808 do { 1809 port = 0; 1810 in.s_addr = htonl(np->in_nip); 1811 if (l == 0) { 1812 /* 1813 * Check to see if there is an existing NAT 1814 * setup for this IP address pair. 1815 */ 1816 hm = nat_hostmap(np, fin->fin_src, fin->fin_dst, 1817 in, 0, ifs); 1818 if (hm != NULL) 1819 in.s_addr = hm->hm_mapip.s_addr; 1820 } else if ((l == 1) && (hm != NULL)) { 1821 nat_hostmapdel(hm); 1822 hm = NULL; 1823 } 1824 in.s_addr = ntohl(in.s_addr); 1825 1826 nat->nat_hm = hm; 1827 1828 if ((np->in_outmsk == 0xffffffff) && (np->in_pnext == 0)) { 1829 if (l > 0) 1830 return -1; 1831 } 1832 1833 if (np->in_redir == NAT_BIMAP && 1834 np->in_inmsk == np->in_outmsk) { 1835 /* 1836 * map the address block in a 1:1 fashion 1837 */ 1838 in.s_addr = np->in_outip; 1839 in.s_addr |= fin->fin_saddr & ~np->in_inmsk; 1840 in.s_addr = ntohl(in.s_addr); 1841 1842 } else if (np->in_redir & NAT_MAPBLK) { 1843 if ((l >= np->in_ppip) || ((l > 0) && 1844 !(flags & IPN_TCPUDP))) 1845 return -1; 1846 /* 1847 * map-block - Calculate destination address. 1848 */ 1849 in.s_addr = ntohl(fin->fin_saddr); 1850 in.s_addr &= ntohl(~np->in_inmsk); 1851 inb.s_addr = in.s_addr; 1852 in.s_addr /= np->in_ippip; 1853 in.s_addr &= ntohl(~np->in_outmsk); 1854 in.s_addr += ntohl(np->in_outip); 1855 /* 1856 * Calculate destination port. 1857 */ 1858 if ((flags & IPN_TCPUDP) && 1859 (np->in_ppip != 0)) { 1860 port = ntohs(sport) + l; 1861 port %= np->in_ppip; 1862 port += np->in_ppip * 1863 (inb.s_addr % np->in_ippip); 1864 port += MAPBLK_MINPORT; 1865 port = htons(port); 1866 } 1867 1868 } else if ((np->in_outip == 0) && 1869 (np->in_outmsk == 0xffffffff)) { 1870 /* 1871 * 0/32 - use the interface's IP address. 1872 */ 1873 if ((l > 0) || 1874 fr_ifpaddr(4, FRI_NORMAL, fin->fin_ifp, 1875 &in, NULL, fin->fin_ifs) == -1) 1876 return -1; 1877 in.s_addr = ntohl(in.s_addr); 1878 1879 } else if ((np->in_outip == 0) && (np->in_outmsk == 0)) { 1880 /* 1881 * 0/0 - use the original source address/port. 1882 */ 1883 if (l > 0) 1884 return -1; 1885 in.s_addr = ntohl(fin->fin_saddr); 1886 1887 } else if ((np->in_outmsk != 0xffffffff) && 1888 (np->in_pnext == 0) && ((l > 0) || (hm == NULL))) 1889 np->in_nip++; 1890 1891 natl = NULL; 1892 1893 if ((flags & IPN_TCPUDP) && 1894 ((np->in_redir & NAT_MAPBLK) == 0) && 1895 (np->in_flags & IPN_AUTOPORTMAP)) { 1896 /* 1897 * "ports auto" (without map-block) 1898 */ 1899 if ((l > 0) && (l % np->in_ppip == 0)) { 1900 if (l > np->in_space) { 1901 return -1; 1902 } else if ((l > np->in_ppip) && 1903 np->in_outmsk != 0xffffffff) 1904 np->in_nip++; 1905 } 1906 if (np->in_ppip != 0) { 1907 port = ntohs(sport); 1908 port += (l % np->in_ppip); 1909 port %= np->in_ppip; 1910 port += np->in_ppip * 1911 (ntohl(fin->fin_saddr) % 1912 np->in_ippip); 1913 port += MAPBLK_MINPORT; 1914 port = htons(port); 1915 } 1916 1917 } else if (((np->in_redir & NAT_MAPBLK) == 0) && 1918 (flags & IPN_TCPUDPICMP) && (np->in_pnext != 0)) { 1919 /* 1920 * Standard port translation. Select next port. 1921 */ 1922 port = htons(np->in_pnext++); 1923 1924 if (np->in_pnext > ntohs(np->in_pmax)) { 1925 np->in_pnext = ntohs(np->in_pmin); 1926 if (np->in_outmsk != 0xffffffff) 1927 np->in_nip++; 1928 } 1929 } 1930 1931 if (np->in_flags & IPN_IPRANGE) { 1932 if (np->in_nip > ntohl(np->in_outmsk)) 1933 np->in_nip = ntohl(np->in_outip); 1934 } else { 1935 if ((np->in_outmsk != 0xffffffff) && 1936 ((np->in_nip + 1) & ntohl(np->in_outmsk)) > 1937 ntohl(np->in_outip)) 1938 np->in_nip = ntohl(np->in_outip) + 1; 1939 } 1940 1941 if ((port == 0) && (flags & (IPN_TCPUDPICMP|IPN_ICMPQUERY))) 1942 port = sport; 1943 1944 /* 1945 * Here we do a lookup of the connection as seen from 1946 * the outside. If an IP# pair already exists, try 1947 * again. So if you have A->B becomes C->B, you can 1948 * also have D->E become C->E but not D->B causing 1949 * another C->B. Also take protocol and ports into 1950 * account when determining whether a pre-existing 1951 * NAT setup will cause an external conflict where 1952 * this is appropriate. 1953 */ 1954 inb.s_addr = htonl(in.s_addr); 1955 sp = fin->fin_data[0]; 1956 dp = fin->fin_data[1]; 1957 fin->fin_data[0] = fin->fin_data[1]; 1958 fin->fin_data[1] = htons(port); 1959 natl = nat_inlookup(fin, flags & ~(SI_WILDP|NAT_SEARCH), 1960 (u_int)fin->fin_p, fin->fin_dst, inb); 1961 fin->fin_data[0] = sp; 1962 fin->fin_data[1] = dp; 1963 1964 /* 1965 * Has the search wrapped around and come back to the 1966 * start ? 1967 */ 1968 if ((natl != NULL) && 1969 (np->in_pnext != 0) && (st_port == np->in_pnext) && 1970 (np->in_nip != 0) && (st_ip == np->in_nip)) 1971 return -1; 1972 l++; 1973 } while (natl != NULL); 1974 1975 if (np->in_space > 0) 1976 np->in_space--; 1977 1978 /* Setup the NAT table */ 1979 nat->nat_inip = fin->fin_src; 1980 nat->nat_outip.s_addr = htonl(in.s_addr); 1981 nat->nat_oip = fin->fin_dst; 1982 if (nat->nat_hm == NULL) 1983 nat->nat_hm = nat_hostmap(np, fin->fin_src, fin->fin_dst, 1984 nat->nat_outip, 0, ifs); 1985 1986 /* 1987 * The ICMP checksum does not have a pseudo header containing 1988 * the IP addresses 1989 */ 1990 ni->nai_sum1 = LONG_SUM(ntohl(fin->fin_saddr)); 1991 ni->nai_sum2 = LONG_SUM(in.s_addr); 1992 if ((flags & IPN_TCPUDP)) { 1993 ni->nai_sum1 += ntohs(sport); 1994 ni->nai_sum2 += ntohs(port); 1995 } 1996 1997 if (flags & IPN_TCPUDP) { 1998 nat->nat_inport = sport; 1999 nat->nat_outport = port; /* sport */ 2000 nat->nat_oport = dport; 2001 ((tcphdr_t *)fin->fin_dp)->th_sport = port; 2002 } else if (flags & IPN_ICMPQUERY) { 2003 ((icmphdr_t *)fin->fin_dp)->icmp_id = port; 2004 nat->nat_inport = port; 2005 nat->nat_outport = port; 2006 } 2007 2008 ni->nai_ip.s_addr = in.s_addr; 2009 ni->nai_port = port; 2010 ni->nai_nport = dport; 2011 return 0; 2012 } 2013 2014 2015 /* ------------------------------------------------------------------------ */ 2016 /* Function: nat_newrdr */ 2017 /* Returns: int - -1 == error, 0 == success (no move), 1 == success and */ 2018 /* allow rule to be moved if IPN_ROUNDR is set. */ 2019 /* Parameters: fin(I) - pointer to packet information */ 2020 /* nat(I) - pointer to NAT entry */ 2021 /* ni(I) - pointer to structure with misc. information needed */ 2022 /* to create new NAT entry. */ 2023 /* */ 2024 /* ni.nai_ip is passed in uninitialised and must be set, in host byte order,*/ 2025 /* to the new IP address for the translation. */ 2026 /* ------------------------------------------------------------------------ */ 2027 static INLINE int nat_newrdr(fin, nat, ni) 2028 fr_info_t *fin; 2029 nat_t *nat; 2030 natinfo_t *ni; 2031 { 2032 u_short nport, dport, sport; 2033 struct in_addr in; 2034 hostmap_t *hm; 2035 u_32_t flags; 2036 ipnat_t *np; 2037 int move; 2038 ipf_stack_t *ifs = fin->fin_ifs; 2039 2040 move = 1; 2041 hm = NULL; 2042 in.s_addr = 0; 2043 np = ni->nai_np; 2044 flags = ni->nai_flags; 2045 sport = ni->nai_sport; 2046 dport = ni->nai_dport; 2047 2048 /* 2049 * If the matching rule has IPN_STICKY set, then we want to have the 2050 * same rule kick in as before. Why would this happen? If you have 2051 * a collection of rdr rules with "round-robin sticky", the current 2052 * packet might match a different one to the previous connection but 2053 * we want the same destination to be used. 2054 */ 2055 if ((np->in_flags & (IPN_ROUNDR|IPN_STICKY)) == 2056 (IPN_ROUNDR|IPN_STICKY)) { 2057 hm = nat_hostmap(NULL, fin->fin_src, fin->fin_dst, in, 2058 (u_32_t)dport, ifs); 2059 if (hm != NULL) { 2060 in.s_addr = ntohl(hm->hm_mapip.s_addr); 2061 np = hm->hm_ipnat; 2062 ni->nai_np = np; 2063 move = 0; 2064 } 2065 } 2066 2067 /* 2068 * Otherwise, it's an inbound packet. Most likely, we don't 2069 * want to rewrite source ports and source addresses. Instead, 2070 * we want to rewrite to a fixed internal address and fixed 2071 * internal port. 2072 */ 2073 if (np->in_flags & IPN_SPLIT) { 2074 in.s_addr = np->in_nip; 2075 2076 if ((np->in_flags & (IPN_ROUNDR|IPN_STICKY)) == IPN_STICKY) { 2077 hm = nat_hostmap(np, fin->fin_src, fin->fin_dst, 2078 in, (u_32_t)dport, ifs); 2079 if (hm != NULL) { 2080 in.s_addr = hm->hm_mapip.s_addr; 2081 move = 0; 2082 } 2083 } 2084 2085 if (hm == NULL || hm->hm_ref == 1) { 2086 if (np->in_inip == htonl(in.s_addr)) { 2087 np->in_nip = ntohl(np->in_inmsk); 2088 move = 0; 2089 } else { 2090 np->in_nip = ntohl(np->in_inip); 2091 } 2092 } 2093 2094 } else if ((np->in_inip == 0) && (np->in_inmsk == 0xffffffff)) { 2095 /* 2096 * 0/32 - use the interface's IP address. 2097 */ 2098 if (fr_ifpaddr(4, FRI_NORMAL, fin->fin_ifp, &in, NULL, 2099 fin->fin_ifs) == -1) 2100 return -1; 2101 in.s_addr = ntohl(in.s_addr); 2102 2103 } else if ((np->in_inip == 0) && (np->in_inmsk== 0)) { 2104 /* 2105 * 0/0 - use the original destination address/port. 2106 */ 2107 in.s_addr = ntohl(fin->fin_daddr); 2108 2109 } else if (np->in_redir == NAT_BIMAP && 2110 np->in_inmsk == np->in_outmsk) { 2111 /* 2112 * map the address block in a 1:1 fashion 2113 */ 2114 in.s_addr = np->in_inip; 2115 in.s_addr |= fin->fin_daddr & ~np->in_inmsk; 2116 in.s_addr = ntohl(in.s_addr); 2117 } else { 2118 in.s_addr = ntohl(np->in_inip); 2119 } 2120 2121 if ((np->in_pnext == 0) || ((flags & NAT_NOTRULEPORT) != 0)) 2122 nport = dport; 2123 else { 2124 /* 2125 * Whilst not optimized for the case where 2126 * pmin == pmax, the gain is not significant. 2127 */ 2128 if (((np->in_flags & IPN_FIXEDDPORT) == 0) && 2129 (np->in_pmin != np->in_pmax)) { 2130 nport = ntohs(dport) - ntohs(np->in_pmin) + 2131 ntohs(np->in_pnext); 2132 nport = htons(nport); 2133 } else 2134 nport = np->in_pnext; 2135 } 2136 2137 /* 2138 * When the redirect-to address is set to 0.0.0.0, just 2139 * assume a blank `forwarding' of the packet. We don't 2140 * setup any translation for this either. 2141 */ 2142 if (in.s_addr == 0) { 2143 if (nport == dport) 2144 return -1; 2145 in.s_addr = ntohl(fin->fin_daddr); 2146 } 2147 2148 nat->nat_inip.s_addr = htonl(in.s_addr); 2149 nat->nat_outip = fin->fin_dst; 2150 nat->nat_oip = fin->fin_src; 2151 2152 ni->nai_sum1 = LONG_SUM(ntohl(fin->fin_daddr)) + ntohs(dport); 2153 ni->nai_sum2 = LONG_SUM(in.s_addr) + ntohs(nport); 2154 2155 ni->nai_ip.s_addr = in.s_addr; 2156 ni->nai_nport = nport; 2157 ni->nai_port = sport; 2158 2159 if (flags & IPN_TCPUDP) { 2160 nat->nat_inport = nport; 2161 nat->nat_outport = dport; 2162 nat->nat_oport = sport; 2163 ((tcphdr_t *)fin->fin_dp)->th_dport = nport; 2164 } else if (flags & IPN_ICMPQUERY) { 2165 ((icmphdr_t *)fin->fin_dp)->icmp_id = nport; 2166 nat->nat_inport = nport; 2167 nat->nat_outport = nport; 2168 } 2169 2170 return move; 2171 } 2172 2173 /* ------------------------------------------------------------------------ */ 2174 /* Function: nat_new */ 2175 /* Returns: nat_t* - NULL == failure to create new NAT structure, */ 2176 /* else pointer to new NAT structure */ 2177 /* Parameters: fin(I) - pointer to packet information */ 2178 /* np(I) - pointer to NAT rule */ 2179 /* natsave(I) - pointer to where to store NAT struct pointer */ 2180 /* flags(I) - flags describing the current packet */ 2181 /* direction(I) - direction of packet (in/out) */ 2182 /* Write Lock: ipf_nat */ 2183 /* */ 2184 /* Attempts to create a new NAT entry. Does not actually change the packet */ 2185 /* in any way. */ 2186 /* */ 2187 /* This fucntion is in three main parts: (1) deal with creating a new NAT */ 2188 /* structure for a "MAP" rule (outgoing NAT translation); (2) deal with */ 2189 /* creating a new NAT structure for a "RDR" rule (incoming NAT translation) */ 2190 /* and (3) building that structure and putting it into the NAT table(s). */ 2191 /* ------------------------------------------------------------------------ */ 2192 nat_t *nat_new(fin, np, natsave, flags, direction) 2193 fr_info_t *fin; 2194 ipnat_t *np; 2195 nat_t **natsave; 2196 u_int flags; 2197 int direction; 2198 { 2199 u_short port = 0, sport = 0, dport = 0, nport = 0; 2200 tcphdr_t *tcp = NULL; 2201 hostmap_t *hm = NULL; 2202 struct in_addr in; 2203 nat_t *nat, *natl; 2204 u_int nflags; 2205 natinfo_t ni; 2206 u_32_t sumd; 2207 int move; 2208 ipf_stack_t *ifs = fin->fin_ifs; 2209 2210 /* 2211 * Trigger automatic call to nat_extraflush() if the 2212 * table has reached capcity specified by hi watermark. 2213 */ 2214 if (NAT_TAB_WATER_LEVEL(ifs) > ifs->ifs_nat_flush_lvl_hi) 2215 ifs->ifs_nat_doflush = 1; 2216 2217 if (ifs->ifs_nat_stats.ns_inuse >= ifs->ifs_ipf_nattable_max) { 2218 ifs->ifs_nat_stats.ns_memfail++; 2219 return NULL; 2220 } 2221 2222 move = 1; 2223 nflags = np->in_flags & flags; 2224 nflags &= NAT_FROMRULE; 2225 2226 ni.nai_np = np; 2227 ni.nai_nflags = nflags; 2228 ni.nai_flags = flags; 2229 2230 /* Give me a new nat */ 2231 KMALLOC(nat, nat_t *); 2232 if (nat == NULL) { 2233 ifs->ifs_nat_stats.ns_memfail++; 2234 /* 2235 * Try to automatically tune the max # of entries in the 2236 * table allowed to be less than what will cause kmem_alloc() 2237 * to fail and try to eliminate panics due to out of memory 2238 * conditions arising. 2239 */ 2240 if (ifs->ifs_ipf_nattable_max > ifs->ifs_ipf_nattable_sz) { 2241 ifs->ifs_ipf_nattable_max = ifs->ifs_nat_stats.ns_inuse - 100; 2242 printf("ipf_nattable_max reduced to %d\n", 2243 ifs->ifs_ipf_nattable_max); 2244 } 2245 return NULL; 2246 } 2247 2248 if (flags & IPN_TCPUDP) { 2249 tcp = fin->fin_dp; 2250 ni.nai_sport = htons(fin->fin_sport); 2251 ni.nai_dport = htons(fin->fin_dport); 2252 } else if (flags & IPN_ICMPQUERY) { 2253 /* 2254 * In the ICMP query NAT code, we translate the ICMP id fields 2255 * to make them unique. This is indepedent of the ICMP type 2256 * (e.g. in the unlikely event that a host sends an echo and 2257 * an tstamp request with the same id, both packets will have 2258 * their ip address/id field changed in the same way). 2259 */ 2260 /* The icmp_id field is used by the sender to identify the 2261 * process making the icmp request. (the receiver justs 2262 * copies it back in its response). So, it closely matches 2263 * the concept of source port. We overlay sport, so we can 2264 * maximally reuse the existing code. 2265 */ 2266 ni.nai_sport = ((icmphdr_t *)fin->fin_dp)->icmp_id; 2267 ni.nai_dport = ni.nai_sport; 2268 } 2269 2270 bzero((char *)nat, sizeof(*nat)); 2271 nat->nat_flags = flags; 2272 nat->nat_redir = np->in_redir; 2273 2274 if ((flags & NAT_SLAVE) == 0) { 2275 MUTEX_ENTER(&ifs->ifs_ipf_nat_new); 2276 } 2277 2278 /* 2279 * Search the current table for a match. 2280 */ 2281 if (direction == NAT_OUTBOUND) { 2282 /* 2283 * We can now arrange to call this for the same connection 2284 * because ipf_nat_new doesn't protect the code path into 2285 * this function. 2286 */ 2287 natl = nat_outlookup(fin, nflags, (u_int)fin->fin_p, 2288 fin->fin_src, fin->fin_dst); 2289 if (natl != NULL) { 2290 KFREE(nat); 2291 nat = natl; 2292 goto done; 2293 } 2294 2295 move = nat_newmap(fin, nat, &ni); 2296 if (move == -1) 2297 goto badnat; 2298 2299 np = ni.nai_np; 2300 in = ni.nai_ip; 2301 } else { 2302 /* 2303 * NAT_INBOUND is used only for redirects rules 2304 */ 2305 natl = nat_inlookup(fin, nflags, (u_int)fin->fin_p, 2306 fin->fin_src, fin->fin_dst); 2307 if (natl != NULL) { 2308 KFREE(nat); 2309 nat = natl; 2310 goto done; 2311 } 2312 2313 move = nat_newrdr(fin, nat, &ni); 2314 if (move == -1) 2315 goto badnat; 2316 2317 np = ni.nai_np; 2318 in = ni.nai_ip; 2319 } 2320 port = ni.nai_port; 2321 nport = ni.nai_nport; 2322 2323 if ((move == 1) && (np->in_flags & IPN_ROUNDR)) { 2324 if (np->in_redir == NAT_REDIRECT) { 2325 nat_delrdr(np); 2326 nat_addrdr(np, ifs); 2327 } else if (np->in_redir == NAT_MAP) { 2328 nat_delnat(np); 2329 nat_addnat(np, ifs); 2330 } 2331 } 2332 2333 if (flags & IPN_TCPUDP) { 2334 sport = ni.nai_sport; 2335 dport = ni.nai_dport; 2336 } else if (flags & IPN_ICMPQUERY) { 2337 sport = ni.nai_sport; 2338 dport = 0; 2339 } 2340 2341 /* 2342 * nat_sumd[0] stores adjustment value including both IP address and 2343 * port number changes. nat_sumd[1] stores adjustment value only for 2344 * IP address changes, to be used for pseudo header adjustment, in 2345 * case hardware partial checksum offload is offered. 2346 */ 2347 CALC_SUMD(ni.nai_sum1, ni.nai_sum2, sumd); 2348 nat->nat_sumd[0] = (sumd & 0xffff) + (sumd >> 16); 2349 #if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6) 2350 if (flags & IPN_TCPUDP) { 2351 ni.nai_sum1 = LONG_SUM(in.s_addr); 2352 if (direction == NAT_OUTBOUND) 2353 ni.nai_sum2 = LONG_SUM(ntohl(fin->fin_saddr)); 2354 else 2355 ni.nai_sum2 = LONG_SUM(ntohl(fin->fin_daddr)); 2356 2357 CALC_SUMD(ni.nai_sum1, ni.nai_sum2, sumd); 2358 nat->nat_sumd[1] = (sumd & 0xffff) + (sumd >> 16); 2359 } else 2360 #endif 2361 nat->nat_sumd[1] = nat->nat_sumd[0]; 2362 2363 if ((flags & IPN_TCPUDPICMP) && ((sport != port) || (dport != nport))) { 2364 if (direction == NAT_OUTBOUND) 2365 ni.nai_sum1 = LONG_SUM(ntohl(fin->fin_saddr)); 2366 else 2367 ni.nai_sum1 = LONG_SUM(ntohl(fin->fin_daddr)); 2368 2369 ni.nai_sum2 = LONG_SUM(in.s_addr); 2370 2371 CALC_SUMD(ni.nai_sum1, ni.nai_sum2, sumd); 2372 nat->nat_ipsumd = (sumd & 0xffff) + (sumd >> 16); 2373 } else { 2374 nat->nat_ipsumd = nat->nat_sumd[0]; 2375 if (!(flags & IPN_TCPUDPICMP)) { 2376 nat->nat_sumd[0] = 0; 2377 nat->nat_sumd[1] = 0; 2378 } 2379 } 2380 2381 if (nat_finalise(fin, nat, &ni, tcp, natsave, direction) == -1) { 2382 goto badnat; 2383 } 2384 if (flags & SI_WILDP) 2385 ifs->ifs_nat_stats.ns_wilds++; 2386 goto done; 2387 badnat: 2388 ifs->ifs_nat_stats.ns_badnat++; 2389 if ((hm = nat->nat_hm) != NULL) 2390 nat_hostmapdel(hm); 2391 KFREE(nat); 2392 nat = NULL; 2393 done: 2394 if ((flags & NAT_SLAVE) == 0) { 2395 MUTEX_EXIT(&ifs->ifs_ipf_nat_new); 2396 } 2397 return nat; 2398 } 2399 2400 2401 /* ------------------------------------------------------------------------ */ 2402 /* Function: nat_finalise */ 2403 /* Returns: int - 0 == sucess, -1 == failure */ 2404 /* Parameters: fin(I) - pointer to packet information */ 2405 /* nat(I) - pointer to NAT entry */ 2406 /* ni(I) - pointer to structure with misc. information needed */ 2407 /* to create new NAT entry. */ 2408 /* Write Lock: ipf_nat */ 2409 /* */ 2410 /* This is the tail end of constructing a new NAT entry and is the same */ 2411 /* for both IPv4 and IPv6. */ 2412 /* ------------------------------------------------------------------------ */ 2413 /*ARGSUSED*/ 2414 static INLINE int nat_finalise(fin, nat, ni, tcp, natsave, direction) 2415 fr_info_t *fin; 2416 nat_t *nat; 2417 natinfo_t *ni; 2418 tcphdr_t *tcp; 2419 nat_t **natsave; 2420 int direction; 2421 { 2422 frentry_t *fr; 2423 ipnat_t *np; 2424 ipf_stack_t *ifs = fin->fin_ifs; 2425 2426 np = ni->nai_np; 2427 2428 COPYIFNAME(fin->fin_ifp, nat->nat_ifnames[0], fin->fin_v); 2429 2430 #ifdef IPFILTER_SYNC 2431 if ((nat->nat_flags & SI_CLONE) == 0) 2432 nat->nat_sync = ipfsync_new(SMC_NAT, fin, nat); 2433 #endif 2434 2435 nat->nat_me = natsave; 2436 nat->nat_dir = direction; 2437 nat->nat_ifps[0] = np->in_ifps[0]; 2438 nat->nat_ifps[1] = np->in_ifps[1]; 2439 nat->nat_ptr = np; 2440 nat->nat_p = fin->fin_p; 2441 nat->nat_mssclamp = np->in_mssclamp; 2442 fr = fin->fin_fr; 2443 nat->nat_fr = fr; 2444 2445 if ((np->in_apr != NULL) && ((ni->nai_flags & NAT_SLAVE) == 0)) 2446 if (appr_new(fin, nat) == -1) 2447 return -1; 2448 2449 if (nat_insert(nat, fin->fin_rev, ifs) == 0) { 2450 if (ifs->ifs_nat_logging) 2451 nat_log(nat, (u_int)np->in_redir, ifs); 2452 np->in_use++; 2453 if (fr != NULL) { 2454 MUTEX_ENTER(&fr->fr_lock); 2455 fr->fr_ref++; 2456 MUTEX_EXIT(&fr->fr_lock); 2457 } 2458 return 0; 2459 } 2460 2461 /* 2462 * nat_insert failed, so cleanup time... 2463 */ 2464 return -1; 2465 } 2466 2467 2468 /* ------------------------------------------------------------------------ */ 2469 /* Function: nat_insert */ 2470 /* Returns: int - 0 == sucess, -1 == failure */ 2471 /* Parameters: nat(I) - pointer to NAT structure */ 2472 /* rev(I) - flag indicating forward/reverse direction of packet */ 2473 /* Write Lock: ipf_nat */ 2474 /* */ 2475 /* Insert a NAT entry into the hash tables for searching and add it to the */ 2476 /* list of active NAT entries. Adjust global counters when complete. */ 2477 /* ------------------------------------------------------------------------ */ 2478 int nat_insert(nat, rev, ifs) 2479 nat_t *nat; 2480 int rev; 2481 ipf_stack_t *ifs; 2482 { 2483 u_int hv1, hv2; 2484 nat_t **natp; 2485 2486 /* 2487 * Try and return an error as early as possible, so calculate the hash 2488 * entry numbers first and then proceed. 2489 */ 2490 if ((nat->nat_flags & (SI_W_SPORT|SI_W_DPORT)) == 0) { 2491 hv1 = NAT_HASH_FN(nat->nat_inip.s_addr, nat->nat_inport, 2492 0xffffffff); 2493 hv1 = NAT_HASH_FN(nat->nat_oip.s_addr, hv1 + nat->nat_oport, 2494 ifs->ifs_ipf_nattable_sz); 2495 hv2 = NAT_HASH_FN(nat->nat_outip.s_addr, nat->nat_outport, 2496 0xffffffff); 2497 hv2 = NAT_HASH_FN(nat->nat_oip.s_addr, hv2 + nat->nat_oport, 2498 ifs->ifs_ipf_nattable_sz); 2499 } else { 2500 hv1 = NAT_HASH_FN(nat->nat_inip.s_addr, 0, 0xffffffff); 2501 hv1 = NAT_HASH_FN(nat->nat_oip.s_addr, hv1, 2502 ifs->ifs_ipf_nattable_sz); 2503 hv2 = NAT_HASH_FN(nat->nat_outip.s_addr, 0, 0xffffffff); 2504 hv2 = NAT_HASH_FN(nat->nat_oip.s_addr, hv2, 2505 ifs->ifs_ipf_nattable_sz); 2506 } 2507 2508 if (ifs->ifs_nat_stats.ns_bucketlen[0][hv1] >= ifs->ifs_fr_nat_maxbucket || 2509 ifs->ifs_nat_stats.ns_bucketlen[1][hv2] >= ifs->ifs_fr_nat_maxbucket) { 2510 return -1; 2511 } 2512 2513 nat->nat_hv[0] = hv1; 2514 nat->nat_hv[1] = hv2; 2515 2516 MUTEX_INIT(&nat->nat_lock, "nat entry lock"); 2517 2518 nat->nat_rev = rev; 2519 nat->nat_ref = 1; 2520 nat->nat_bytes[0] = 0; 2521 nat->nat_pkts[0] = 0; 2522 nat->nat_bytes[1] = 0; 2523 nat->nat_pkts[1] = 0; 2524 2525 nat->nat_ifnames[0][LIFNAMSIZ - 1] = '\0'; 2526 nat->nat_ifps[0] = fr_resolvenic(nat->nat_ifnames[0], 4, ifs); 2527 2528 if (nat->nat_ifnames[1][0] !='\0') { 2529 nat->nat_ifnames[1][LIFNAMSIZ - 1] = '\0'; 2530 nat->nat_ifps[1] = fr_resolvenic(nat->nat_ifnames[1], 4, ifs); 2531 } else { 2532 (void) strncpy(nat->nat_ifnames[1], nat->nat_ifnames[0], 2533 LIFNAMSIZ); 2534 nat->nat_ifnames[1][LIFNAMSIZ - 1] = '\0'; 2535 nat->nat_ifps[1] = nat->nat_ifps[0]; 2536 } 2537 2538 nat->nat_next = ifs->ifs_nat_instances; 2539 nat->nat_pnext = &ifs->ifs_nat_instances; 2540 if (ifs->ifs_nat_instances) 2541 ifs->ifs_nat_instances->nat_pnext = &nat->nat_next; 2542 ifs->ifs_nat_instances = nat; 2543 2544 natp = &ifs->ifs_nat_table[0][hv1]; 2545 if (*natp) 2546 (*natp)->nat_phnext[0] = &nat->nat_hnext[0]; 2547 nat->nat_phnext[0] = natp; 2548 nat->nat_hnext[0] = *natp; 2549 *natp = nat; 2550 ifs->ifs_nat_stats.ns_bucketlen[0][hv1]++; 2551 2552 natp = &ifs->ifs_nat_table[1][hv2]; 2553 if (*natp) 2554 (*natp)->nat_phnext[1] = &nat->nat_hnext[1]; 2555 nat->nat_phnext[1] = natp; 2556 nat->nat_hnext[1] = *natp; 2557 *natp = nat; 2558 ifs->ifs_nat_stats.ns_bucketlen[1][hv2]++; 2559 2560 fr_setnatqueue(nat, rev, ifs); 2561 2562 ifs->ifs_nat_stats.ns_added++; 2563 ifs->ifs_nat_stats.ns_inuse++; 2564 return 0; 2565 } 2566 2567 2568 /* ------------------------------------------------------------------------ */ 2569 /* Function: nat_icmperrorlookup */ 2570 /* Returns: nat_t* - point to matching NAT structure */ 2571 /* Parameters: fin(I) - pointer to packet information */ 2572 /* dir(I) - direction of packet (in/out) */ 2573 /* */ 2574 /* Check if the ICMP error message is related to an existing TCP, UDP or */ 2575 /* ICMP query nat entry. It is assumed that the packet is already of the */ 2576 /* the required length. */ 2577 /* ------------------------------------------------------------------------ */ 2578 nat_t *nat_icmperrorlookup(fin, dir) 2579 fr_info_t *fin; 2580 int dir; 2581 { 2582 int flags = 0, minlen; 2583 icmphdr_t *orgicmp; 2584 tcphdr_t *tcp = NULL; 2585 u_short data[2]; 2586 nat_t *nat; 2587 ip_t *oip; 2588 u_int p; 2589 2590 /* 2591 * Does it at least have the return (basic) IP header ? 2592 * Only a basic IP header (no options) should be with an ICMP error 2593 * header. Also, if it's not an error type, then return. 2594 */ 2595 if ((fin->fin_hlen != sizeof(ip_t)) || !(fin->fin_flx & FI_ICMPERR)) 2596 return NULL; 2597 2598 /* 2599 * Check packet size 2600 */ 2601 oip = (ip_t *)((char *)fin->fin_dp + 8); 2602 minlen = IP_HL(oip) << 2; 2603 if ((minlen < sizeof(ip_t)) || 2604 (fin->fin_plen < ICMPERR_IPICMPHLEN + minlen)) 2605 return NULL; 2606 /* 2607 * Is the buffer big enough for all of it ? It's the size of the IP 2608 * header claimed in the encapsulated part which is of concern. It 2609 * may be too big to be in this buffer but not so big that it's 2610 * outside the ICMP packet, leading to TCP deref's causing problems. 2611 * This is possible because we don't know how big oip_hl is when we 2612 * do the pullup early in fr_check() and thus can't gaurantee it is 2613 * all here now. 2614 */ 2615 #ifdef _KERNEL 2616 { 2617 mb_t *m; 2618 2619 m = fin->fin_m; 2620 # if defined(MENTAT) 2621 if ((char *)oip + fin->fin_dlen - ICMPERR_ICMPHLEN > (char *)m->b_wptr) 2622 return NULL; 2623 # else 2624 if ((char *)oip + fin->fin_dlen - ICMPERR_ICMPHLEN > 2625 (char *)fin->fin_ip + M_LEN(m)) 2626 return NULL; 2627 # endif 2628 } 2629 #endif 2630 2631 if (fin->fin_daddr != oip->ip_src.s_addr) 2632 return NULL; 2633 2634 p = oip->ip_p; 2635 if (p == IPPROTO_TCP) 2636 flags = IPN_TCP; 2637 else if (p == IPPROTO_UDP) 2638 flags = IPN_UDP; 2639 else if (p == IPPROTO_ICMP) { 2640 orgicmp = (icmphdr_t *)((char *)oip + (IP_HL(oip) << 2)); 2641 2642 /* see if this is related to an ICMP query */ 2643 if (nat_icmpquerytype4(orgicmp->icmp_type)) { 2644 data[0] = fin->fin_data[0]; 2645 data[1] = fin->fin_data[1]; 2646 fin->fin_data[0] = 0; 2647 fin->fin_data[1] = orgicmp->icmp_id; 2648 2649 flags = IPN_ICMPERR|IPN_ICMPQUERY; 2650 /* 2651 * NOTE : dir refers to the direction of the original 2652 * ip packet. By definition the icmp error 2653 * message flows in the opposite direction. 2654 */ 2655 if (dir == NAT_INBOUND) 2656 nat = nat_inlookup(fin, flags, p, oip->ip_dst, 2657 oip->ip_src); 2658 else 2659 nat = nat_outlookup(fin, flags, p, oip->ip_dst, 2660 oip->ip_src); 2661 fin->fin_data[0] = data[0]; 2662 fin->fin_data[1] = data[1]; 2663 return nat; 2664 } 2665 } 2666 2667 if (flags & IPN_TCPUDP) { 2668 minlen += 8; /* + 64bits of data to get ports */ 2669 if (fin->fin_plen < ICMPERR_IPICMPHLEN + minlen) 2670 return NULL; 2671 2672 data[0] = fin->fin_data[0]; 2673 data[1] = fin->fin_data[1]; 2674 tcp = (tcphdr_t *)((char *)oip + (IP_HL(oip) << 2)); 2675 fin->fin_data[0] = ntohs(tcp->th_dport); 2676 fin->fin_data[1] = ntohs(tcp->th_sport); 2677 2678 if (dir == NAT_INBOUND) { 2679 nat = nat_inlookup(fin, flags, p, oip->ip_dst, 2680 oip->ip_src); 2681 } else { 2682 nat = nat_outlookup(fin, flags, p, oip->ip_dst, 2683 oip->ip_src); 2684 } 2685 fin->fin_data[0] = data[0]; 2686 fin->fin_data[1] = data[1]; 2687 return nat; 2688 } 2689 if (dir == NAT_INBOUND) 2690 return nat_inlookup(fin, 0, p, oip->ip_dst, oip->ip_src); 2691 else 2692 return nat_outlookup(fin, 0, p, oip->ip_dst, oip->ip_src); 2693 } 2694 2695 2696 /* ------------------------------------------------------------------------ */ 2697 /* Function: nat_icmperror */ 2698 /* Returns: nat_t* - point to matching NAT structure */ 2699 /* Parameters: fin(I) - pointer to packet information */ 2700 /* nflags(I) - NAT flags for this packet */ 2701 /* dir(I) - direction of packet (in/out) */ 2702 /* */ 2703 /* Fix up an ICMP packet which is an error message for an existing NAT */ 2704 /* session. This will correct both packet header data and checksums. */ 2705 /* */ 2706 /* This should *ONLY* be used for incoming ICMP error packets to make sure */ 2707 /* a NAT'd ICMP packet gets correctly recognised. */ 2708 /* ------------------------------------------------------------------------ */ 2709 nat_t *nat_icmperror(fin, nflags, dir) 2710 fr_info_t *fin; 2711 u_int *nflags; 2712 int dir; 2713 { 2714 u_32_t sum1, sum2, sumd, psum1, psum2, psumd, sumd2; 2715 struct in_addr in; 2716 icmphdr_t *icmp, *orgicmp; 2717 int dlen; 2718 udphdr_t *udp; 2719 tcphdr_t *tcp; 2720 nat_t *nat; 2721 ip_t *oip; 2722 if ((fin->fin_flx & (FI_SHORT|FI_FRAGBODY))) 2723 return NULL; 2724 2725 /* 2726 * nat_icmperrorlookup() looks up nat entry associated with the 2727 * offending IP packet and returns pointer to the entry, or NULL 2728 * if packet wasn't natted or for `defective' packets. 2729 */ 2730 2731 if ((fin->fin_v != 4) || !(nat = nat_icmperrorlookup(fin, dir))) 2732 return NULL; 2733 2734 sumd2 = 0; 2735 *nflags = IPN_ICMPERR; 2736 icmp = fin->fin_dp; 2737 oip = (ip_t *)&icmp->icmp_ip; 2738 udp = (udphdr_t *)((((char *)oip) + (IP_HL(oip) << 2))); 2739 tcp = (tcphdr_t *)udp; 2740 dlen = fin->fin_plen - ((char *)udp - (char *)fin->fin_ip); 2741 2742 /* 2743 * Need to adjust ICMP header to include the real IP#'s and 2744 * port #'s. There are three steps required. 2745 * 2746 * Step 1 2747 * Fix the IP addresses in the offending IP packet and update 2748 * ip header checksum to compensate for the change. 2749 * 2750 * No update needed here for icmp_cksum because the ICMP checksum 2751 * is calculated over the complete ICMP packet, which includes the 2752 * changed oip IP addresses and oip->ip_sum. These two changes 2753 * cancel each other out (if the delta for the IP address is x, 2754 * then the delta for ip_sum is minus x). 2755 */ 2756 2757 if (oip->ip_dst.s_addr == nat->nat_oip.s_addr) { 2758 sum1 = LONG_SUM(ntohl(oip->ip_src.s_addr)); 2759 in = nat->nat_inip; 2760 oip->ip_src = in; 2761 } else { 2762 sum1 = LONG_SUM(ntohl(oip->ip_dst.s_addr)); 2763 in = nat->nat_outip; 2764 oip->ip_dst = in; 2765 } 2766 2767 sum2 = LONG_SUM(ntohl(in.s_addr)); 2768 CALC_SUMD(sum1, sum2, sumd); 2769 fix_datacksum(&oip->ip_sum, sumd); 2770 2771 /* 2772 * Step 2 2773 * Perform other adjustments based on protocol of offending packet. 2774 */ 2775 2776 switch (oip->ip_p) { 2777 case IPPROTO_TCP : 2778 case IPPROTO_UDP : 2779 2780 /* 2781 * For offending TCP/UDP IP packets, translate the ports 2782 * based on the NAT specification. 2783 * 2784 * Advance notice : Now it becomes complicated :-) 2785 * 2786 * Since the port and IP addresse fields are both part 2787 * of the TCP/UDP checksum of the offending IP packet, 2788 * we need to adjust that checksum as well. 2789 * 2790 * To further complicate things, the TCP/UDP checksum 2791 * may not be present. We must check to see if the 2792 * length of the data portion is big enough to hold 2793 * the checksum. In the UDP case, a test to determine 2794 * if the checksum is even set is also required. 2795 * 2796 * Any changes to an IP address, port or checksum within 2797 * the ICMP packet requires a change to icmp_cksum. 2798 * 2799 * Be extremely careful here ... The change is dependent 2800 * upon whether or not the TCP/UPD checksum is present. 2801 * 2802 * If TCP/UPD checksum is present, the icmp_cksum must 2803 * compensate for checksum modification resulting from 2804 * IP address change only. Port change and resulting 2805 * data checksum adjustments cancel each other out. 2806 * 2807 * If TCP/UDP checksum is not present, icmp_cksum must 2808 * compensate for port change only. The IP address 2809 * change does not modify anything else in this case. 2810 */ 2811 2812 psum1 = 0; 2813 psum2 = 0; 2814 psumd = 0; 2815 2816 if ((tcp->th_dport == nat->nat_oport) && 2817 (tcp->th_sport != nat->nat_inport)) { 2818 2819 /* 2820 * Translate the source port. 2821 */ 2822 2823 psum1 = ntohs(tcp->th_sport); 2824 psum2 = ntohs(nat->nat_inport); 2825 tcp->th_sport = nat->nat_inport; 2826 2827 } else if ((tcp->th_sport == nat->nat_oport) && 2828 (tcp->th_dport != nat->nat_outport)) { 2829 2830 /* 2831 * Translate the destination port. 2832 */ 2833 2834 psum1 = ntohs(tcp->th_dport); 2835 psum2 = ntohs(nat->nat_outport); 2836 tcp->th_dport = nat->nat_outport; 2837 } 2838 2839 if ((oip->ip_p == IPPROTO_TCP) && (dlen >= 18)) { 2840 2841 /* 2842 * TCP checksum present. 2843 * 2844 * Adjust data checksum and icmp checksum to 2845 * compensate for any IP address change. 2846 */ 2847 2848 sum1 = ntohs(tcp->th_sum); 2849 fix_datacksum(&tcp->th_sum, sumd); 2850 sum2 = ntohs(tcp->th_sum); 2851 sumd2 = sumd << 1; 2852 CALC_SUMD(sum1, sum2, sumd); 2853 sumd2 += sumd; 2854 2855 /* 2856 * Also make data checksum adjustment to 2857 * compensate for any port change. 2858 */ 2859 2860 if (psum1 != psum2) { 2861 CALC_SUMD(psum1, psum2, psumd); 2862 fix_datacksum(&tcp->th_sum, psumd); 2863 } 2864 2865 } else if ((oip->ip_p == IPPROTO_UDP) && 2866 (dlen >= 8) && (udp->uh_sum != 0)) { 2867 2868 /* 2869 * The UDP checksum is present and set. 2870 * 2871 * Adjust data checksum and icmp checksum to 2872 * compensate for any IP address change. 2873 */ 2874 2875 sum1 = ntohs(udp->uh_sum); 2876 fix_datacksum(&udp->uh_sum, sumd); 2877 sum2 = ntohs(udp->uh_sum); 2878 sumd2 = sumd << 1; 2879 CALC_SUMD(sum1, sum2, sumd); 2880 sumd2 += sumd; 2881 2882 /* 2883 * Also make data checksum adjustment to 2884 * compensate for any port change. 2885 */ 2886 2887 if (psum1 != psum2) { 2888 CALC_SUMD(psum1, psum2, psumd); 2889 fix_datacksum(&udp->uh_sum, psumd); 2890 } 2891 2892 } else { 2893 2894 /* 2895 * Data checksum was not present. 2896 * 2897 * Compensate for any port change. 2898 */ 2899 2900 CALC_SUMD(psum2, psum1, psumd); 2901 sumd2 += psumd; 2902 } 2903 break; 2904 2905 case IPPROTO_ICMP : 2906 2907 orgicmp = (icmphdr_t *)udp; 2908 2909 if ((nat->nat_dir == NAT_OUTBOUND) && 2910 (orgicmp->icmp_id != nat->nat_inport) && 2911 (dlen >= 8)) { 2912 2913 /* 2914 * Fix ICMP checksum (of the offening ICMP 2915 * query packet) to compensate the change 2916 * in the ICMP id of the offending ICMP 2917 * packet. 2918 * 2919 * Since you modify orgicmp->icmp_id with 2920 * a delta (say x) and you compensate that 2921 * in origicmp->icmp_cksum with a delta 2922 * minus x, you don't have to adjust the 2923 * overall icmp->icmp_cksum 2924 */ 2925 2926 sum1 = ntohs(orgicmp->icmp_id); 2927 sum2 = ntohs(nat->nat_inport); 2928 CALC_SUMD(sum1, sum2, sumd); 2929 orgicmp->icmp_id = nat->nat_inport; 2930 fix_datacksum(&orgicmp->icmp_cksum, sumd); 2931 2932 } /* nat_dir can't be NAT_INBOUND for icmp queries */ 2933 2934 break; 2935 2936 default : 2937 2938 break; 2939 2940 } /* switch (oip->ip_p) */ 2941 2942 /* 2943 * Step 3 2944 * Make the adjustments to icmp checksum. 2945 */ 2946 2947 if (sumd2 != 0) { 2948 sumd2 = (sumd2 & 0xffff) + (sumd2 >> 16); 2949 sumd2 = (sumd2 & 0xffff) + (sumd2 >> 16); 2950 fix_incksum(&icmp->icmp_cksum, sumd2); 2951 } 2952 return nat; 2953 } 2954 2955 2956 /* 2957 * NB: these lookups don't lock access to the list, it assumed that it has 2958 * already been done! 2959 */ 2960 2961 /* ------------------------------------------------------------------------ */ 2962 /* Function: nat_inlookup */ 2963 /* Returns: nat_t* - NULL == no match, */ 2964 /* else pointer to matching NAT entry */ 2965 /* Parameters: fin(I) - pointer to packet information */ 2966 /* flags(I) - NAT flags for this packet */ 2967 /* p(I) - protocol for this packet */ 2968 /* src(I) - source IP address */ 2969 /* mapdst(I) - destination IP address */ 2970 /* */ 2971 /* Lookup a nat entry based on the mapped destination ip address/port and */ 2972 /* real source address/port. We use this lookup when receiving a packet, */ 2973 /* we're looking for a table entry, based on the destination address. */ 2974 /* */ 2975 /* NOTE: THE PACKET BEING CHECKED (IF FOUND) HAS A MAPPING ALREADY. */ 2976 /* */ 2977 /* NOTE: IT IS ASSUMED THAT ipf_nat IS ONLY HELD WITH A READ LOCK WHEN */ 2978 /* THIS FUNCTION IS CALLED WITH NAT_SEARCH SET IN nflags. */ 2979 /* */ 2980 /* flags -> relevant are IPN_UDP/IPN_TCP/IPN_ICMPQUERY that indicate if */ 2981 /* the packet is of said protocol */ 2982 /* ------------------------------------------------------------------------ */ 2983 nat_t *nat_inlookup(fin, flags, p, src, mapdst) 2984 fr_info_t *fin; 2985 u_int flags, p; 2986 struct in_addr src , mapdst; 2987 { 2988 u_short sport, dport; 2989 ipnat_t *ipn; 2990 u_int sflags; 2991 nat_t *nat; 2992 int nflags; 2993 u_32_t dst; 2994 void *ifp; 2995 u_int hv; 2996 ipf_stack_t *ifs = fin->fin_ifs; 2997 2998 if (fin != NULL) 2999 ifp = fin->fin_ifp; 3000 else 3001 ifp = NULL; 3002 sport = 0; 3003 dport = 0; 3004 dst = mapdst.s_addr; 3005 sflags = flags & NAT_TCPUDPICMP; 3006 3007 switch (p) 3008 { 3009 case IPPROTO_TCP : 3010 case IPPROTO_UDP : 3011 sport = htons(fin->fin_data[0]); 3012 dport = htons(fin->fin_data[1]); 3013 break; 3014 case IPPROTO_ICMP : 3015 if (flags & IPN_ICMPERR) 3016 sport = fin->fin_data[1]; 3017 else 3018 dport = fin->fin_data[1]; 3019 break; 3020 default : 3021 break; 3022 } 3023 3024 3025 if ((flags & SI_WILDP) != 0) 3026 goto find_in_wild_ports; 3027 3028 hv = NAT_HASH_FN(dst, dport, 0xffffffff); 3029 hv = NAT_HASH_FN(src.s_addr, hv + sport, ifs->ifs_ipf_nattable_sz); 3030 nat = ifs->ifs_nat_table[1][hv]; 3031 for (; nat; nat = nat->nat_hnext[1]) { 3032 if (nat->nat_ifps[0] != NULL) { 3033 if ((ifp != NULL) && (ifp != nat->nat_ifps[0])) 3034 continue; 3035 } else if (ifp != NULL) 3036 nat->nat_ifps[0] = ifp; 3037 3038 nflags = nat->nat_flags; 3039 3040 if (nat->nat_oip.s_addr == src.s_addr && 3041 nat->nat_outip.s_addr == dst && 3042 (((p == 0) && 3043 (sflags == (nat->nat_flags & IPN_TCPUDPICMP))) 3044 || (p == nat->nat_p))) { 3045 switch (p) 3046 { 3047 #if 0 3048 case IPPROTO_GRE : 3049 if (nat->nat_call[1] != fin->fin_data[0]) 3050 continue; 3051 break; 3052 #endif 3053 case IPPROTO_ICMP : 3054 if ((flags & IPN_ICMPERR) != 0) { 3055 if (nat->nat_outport != sport) 3056 continue; 3057 } else { 3058 if (nat->nat_outport != dport) 3059 continue; 3060 } 3061 break; 3062 case IPPROTO_TCP : 3063 case IPPROTO_UDP : 3064 if (nat->nat_oport != sport) 3065 continue; 3066 if (nat->nat_outport != dport) 3067 continue; 3068 break; 3069 default : 3070 break; 3071 } 3072 3073 ipn = nat->nat_ptr; 3074 if ((ipn != NULL) && (nat->nat_aps != NULL)) 3075 if (appr_match(fin, nat) != 0) 3076 continue; 3077 return nat; 3078 } 3079 } 3080 3081 /* 3082 * So if we didn't find it but there are wildcard members in the hash 3083 * table, go back and look for them. We do this search and update here 3084 * because it is modifying the NAT table and we want to do this only 3085 * for the first packet that matches. The exception, of course, is 3086 * for "dummy" (FI_IGNORE) lookups. 3087 */ 3088 find_in_wild_ports: 3089 if (!(flags & NAT_TCPUDP) || !(flags & NAT_SEARCH)) 3090 return NULL; 3091 if (ifs->ifs_nat_stats.ns_wilds == 0) 3092 return NULL; 3093 3094 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 3095 3096 hv = NAT_HASH_FN(dst, 0, 0xffffffff); 3097 hv = NAT_HASH_FN(src.s_addr, hv, ifs->ifs_ipf_nattable_sz); 3098 3099 WRITE_ENTER(&ifs->ifs_ipf_nat); 3100 3101 nat = ifs->ifs_nat_table[1][hv]; 3102 for (; nat; nat = nat->nat_hnext[1]) { 3103 if (nat->nat_ifps[0] != NULL) { 3104 if ((ifp != NULL) && (ifp != nat->nat_ifps[0])) 3105 continue; 3106 } else if (ifp != NULL) 3107 nat->nat_ifps[0] = ifp; 3108 3109 if (nat->nat_p != fin->fin_p) 3110 continue; 3111 if (nat->nat_oip.s_addr != src.s_addr || 3112 nat->nat_outip.s_addr != dst) 3113 continue; 3114 3115 nflags = nat->nat_flags; 3116 if (!(nflags & (NAT_TCPUDP|SI_WILDP))) 3117 continue; 3118 3119 if (nat_wildok(nat, (int)sport, (int)dport, nflags, 3120 NAT_INBOUND) == 1) { 3121 if ((fin->fin_flx & FI_IGNORE) != 0) 3122 break; 3123 if ((nflags & SI_CLONE) != 0) { 3124 nat = fr_natclone(fin, nat); 3125 if (nat == NULL) 3126 break; 3127 } else { 3128 MUTEX_ENTER(&ifs->ifs_ipf_nat_new); 3129 ifs->ifs_nat_stats.ns_wilds--; 3130 MUTEX_EXIT(&ifs->ifs_ipf_nat_new); 3131 } 3132 nat->nat_oport = sport; 3133 nat->nat_outport = dport; 3134 nat->nat_flags &= ~(SI_W_DPORT|SI_W_SPORT); 3135 nat_tabmove(nat, ifs); 3136 break; 3137 } 3138 } 3139 3140 MUTEX_DOWNGRADE(&ifs->ifs_ipf_nat); 3141 3142 return nat; 3143 } 3144 3145 3146 /* ------------------------------------------------------------------------ */ 3147 /* Function: nat_tabmove */ 3148 /* Returns: Nil */ 3149 /* Parameters: nat(I) - pointer to NAT structure */ 3150 /* Write Lock: ipf_nat */ 3151 /* */ 3152 /* This function is only called for TCP/UDP NAT table entries where the */ 3153 /* original was placed in the table without hashing on the ports and we now */ 3154 /* want to include hashing on port numbers. */ 3155 /* ------------------------------------------------------------------------ */ 3156 static void nat_tabmove(nat, ifs) 3157 nat_t *nat; 3158 ipf_stack_t *ifs; 3159 { 3160 nat_t **natp; 3161 u_int hv; 3162 3163 if (nat->nat_flags & SI_CLONE) 3164 return; 3165 3166 /* 3167 * Remove the NAT entry from the old location 3168 */ 3169 if (nat->nat_hnext[0]) 3170 nat->nat_hnext[0]->nat_phnext[0] = nat->nat_phnext[0]; 3171 *nat->nat_phnext[0] = nat->nat_hnext[0]; 3172 ifs->ifs_nat_stats.ns_bucketlen[0][nat->nat_hv[0]]--; 3173 3174 if (nat->nat_hnext[1]) 3175 nat->nat_hnext[1]->nat_phnext[1] = nat->nat_phnext[1]; 3176 *nat->nat_phnext[1] = nat->nat_hnext[1]; 3177 ifs->ifs_nat_stats.ns_bucketlen[1][nat->nat_hv[1]]--; 3178 3179 /* 3180 * Add into the NAT table in the new position 3181 */ 3182 hv = NAT_HASH_FN(nat->nat_inip.s_addr, nat->nat_inport, 0xffffffff); 3183 hv = NAT_HASH_FN(nat->nat_oip.s_addr, hv + nat->nat_oport, 3184 ifs->ifs_ipf_nattable_sz); 3185 nat->nat_hv[0] = hv; 3186 natp = &ifs->ifs_nat_table[0][hv]; 3187 if (*natp) 3188 (*natp)->nat_phnext[0] = &nat->nat_hnext[0]; 3189 nat->nat_phnext[0] = natp; 3190 nat->nat_hnext[0] = *natp; 3191 *natp = nat; 3192 ifs->ifs_nat_stats.ns_bucketlen[0][hv]++; 3193 3194 hv = NAT_HASH_FN(nat->nat_outip.s_addr, nat->nat_outport, 0xffffffff); 3195 hv = NAT_HASH_FN(nat->nat_oip.s_addr, hv + nat->nat_oport, 3196 ifs->ifs_ipf_nattable_sz); 3197 nat->nat_hv[1] = hv; 3198 natp = &ifs->ifs_nat_table[1][hv]; 3199 if (*natp) 3200 (*natp)->nat_phnext[1] = &nat->nat_hnext[1]; 3201 nat->nat_phnext[1] = natp; 3202 nat->nat_hnext[1] = *natp; 3203 *natp = nat; 3204 ifs->ifs_nat_stats.ns_bucketlen[1][hv]++; 3205 } 3206 3207 3208 /* ------------------------------------------------------------------------ */ 3209 /* Function: nat_outlookup */ 3210 /* Returns: nat_t* - NULL == no match, */ 3211 /* else pointer to matching NAT entry */ 3212 /* Parameters: fin(I) - pointer to packet information */ 3213 /* flags(I) - NAT flags for this packet */ 3214 /* p(I) - protocol for this packet */ 3215 /* src(I) - source IP address */ 3216 /* dst(I) - destination IP address */ 3217 /* rw(I) - 1 == write lock on ipf_nat held, 0 == read lock. */ 3218 /* */ 3219 /* Lookup a nat entry based on the source 'real' ip address/port and */ 3220 /* destination address/port. We use this lookup when sending a packet out, */ 3221 /* we're looking for a table entry, based on the source address. */ 3222 /* */ 3223 /* NOTE: THE PACKET BEING CHECKED (IF FOUND) HAS A MAPPING ALREADY. */ 3224 /* */ 3225 /* NOTE: IT IS ASSUMED THAT ipf_nat IS ONLY HELD WITH A READ LOCK WHEN */ 3226 /* THIS FUNCTION IS CALLED WITH NAT_SEARCH SET IN nflags. */ 3227 /* */ 3228 /* flags -> relevant are IPN_UDP/IPN_TCP/IPN_ICMPQUERY that indicate if */ 3229 /* the packet is of said protocol */ 3230 /* ------------------------------------------------------------------------ */ 3231 nat_t *nat_outlookup(fin, flags, p, src, dst) 3232 fr_info_t *fin; 3233 u_int flags, p; 3234 struct in_addr src , dst; 3235 { 3236 u_short sport, dport; 3237 u_int sflags; 3238 ipnat_t *ipn; 3239 u_32_t srcip; 3240 nat_t *nat; 3241 int nflags; 3242 void *ifp; 3243 u_int hv; 3244 ipf_stack_t *ifs = fin->fin_ifs; 3245 3246 ifp = fin->fin_ifp; 3247 3248 srcip = src.s_addr; 3249 sflags = flags & IPN_TCPUDPICMP; 3250 sport = 0; 3251 dport = 0; 3252 3253 switch (p) 3254 { 3255 case IPPROTO_TCP : 3256 case IPPROTO_UDP : 3257 sport = htons(fin->fin_data[0]); 3258 dport = htons(fin->fin_data[1]); 3259 break; 3260 case IPPROTO_ICMP : 3261 if (flags & IPN_ICMPERR) 3262 sport = fin->fin_data[1]; 3263 else 3264 dport = fin->fin_data[1]; 3265 break; 3266 default : 3267 break; 3268 } 3269 3270 if ((flags & SI_WILDP) != 0) 3271 goto find_out_wild_ports; 3272 3273 hv = NAT_HASH_FN(srcip, sport, 0xffffffff); 3274 hv = NAT_HASH_FN(dst.s_addr, hv + dport, ifs->ifs_ipf_nattable_sz); 3275 nat = ifs->ifs_nat_table[0][hv]; 3276 for (; nat; nat = nat->nat_hnext[0]) { 3277 if (nat->nat_ifps[1] != NULL) { 3278 if ((ifp != NULL) && (ifp != nat->nat_ifps[1])) 3279 continue; 3280 } else if (ifp != NULL) 3281 nat->nat_ifps[1] = ifp; 3282 3283 nflags = nat->nat_flags; 3284 3285 if (nat->nat_inip.s_addr == srcip && 3286 nat->nat_oip.s_addr == dst.s_addr && 3287 (((p == 0) && (sflags == (nflags & NAT_TCPUDPICMP))) 3288 || (p == nat->nat_p))) { 3289 switch (p) 3290 { 3291 #if 0 3292 case IPPROTO_GRE : 3293 if (nat->nat_call[1] != fin->fin_data[0]) 3294 continue; 3295 break; 3296 #endif 3297 case IPPROTO_TCP : 3298 case IPPROTO_UDP : 3299 if (nat->nat_oport != dport) 3300 continue; 3301 if (nat->nat_inport != sport) 3302 continue; 3303 break; 3304 default : 3305 break; 3306 } 3307 3308 ipn = nat->nat_ptr; 3309 if ((ipn != NULL) && (nat->nat_aps != NULL)) 3310 if (appr_match(fin, nat) != 0) 3311 continue; 3312 return nat; 3313 } 3314 } 3315 3316 /* 3317 * So if we didn't find it but there are wildcard members in the hash 3318 * table, go back and look for them. We do this search and update here 3319 * because it is modifying the NAT table and we want to do this only 3320 * for the first packet that matches. The exception, of course, is 3321 * for "dummy" (FI_IGNORE) lookups. 3322 */ 3323 find_out_wild_ports: 3324 if (!(flags & NAT_TCPUDP) || !(flags & NAT_SEARCH)) 3325 return NULL; 3326 if (ifs->ifs_nat_stats.ns_wilds == 0) 3327 return NULL; 3328 3329 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 3330 3331 hv = NAT_HASH_FN(srcip, 0, 0xffffffff); 3332 hv = NAT_HASH_FN(dst.s_addr, hv, ifs->ifs_ipf_nattable_sz); 3333 3334 WRITE_ENTER(&ifs->ifs_ipf_nat); 3335 3336 nat = ifs->ifs_nat_table[0][hv]; 3337 for (; nat; nat = nat->nat_hnext[0]) { 3338 if (nat->nat_ifps[1] != NULL) { 3339 if ((ifp != NULL) && (ifp != nat->nat_ifps[1])) 3340 continue; 3341 } else if (ifp != NULL) 3342 nat->nat_ifps[1] = ifp; 3343 3344 if (nat->nat_p != fin->fin_p) 3345 continue; 3346 if ((nat->nat_inip.s_addr != srcip) || 3347 (nat->nat_oip.s_addr != dst.s_addr)) 3348 continue; 3349 3350 nflags = nat->nat_flags; 3351 if (!(nflags & (NAT_TCPUDP|SI_WILDP))) 3352 continue; 3353 3354 if (nat_wildok(nat, (int)sport, (int)dport, nflags, 3355 NAT_OUTBOUND) == 1) { 3356 if ((fin->fin_flx & FI_IGNORE) != 0) 3357 break; 3358 if ((nflags & SI_CLONE) != 0) { 3359 nat = fr_natclone(fin, nat); 3360 if (nat == NULL) 3361 break; 3362 } else { 3363 MUTEX_ENTER(&ifs->ifs_ipf_nat_new); 3364 ifs->ifs_nat_stats.ns_wilds--; 3365 MUTEX_EXIT(&ifs->ifs_ipf_nat_new); 3366 } 3367 nat->nat_inport = sport; 3368 nat->nat_oport = dport; 3369 if (nat->nat_outport == 0) 3370 nat->nat_outport = sport; 3371 nat->nat_flags &= ~(SI_W_DPORT|SI_W_SPORT); 3372 nat_tabmove(nat, ifs); 3373 break; 3374 } 3375 } 3376 3377 MUTEX_DOWNGRADE(&ifs->ifs_ipf_nat); 3378 3379 return nat; 3380 } 3381 3382 3383 /* ------------------------------------------------------------------------ */ 3384 /* Function: nat_lookupredir */ 3385 /* Returns: nat_t* - NULL == no match, */ 3386 /* else pointer to matching NAT entry */ 3387 /* Parameters: np(I) - pointer to description of packet to find NAT table */ 3388 /* entry for. */ 3389 /* */ 3390 /* Lookup the NAT tables to search for a matching redirect */ 3391 /* ------------------------------------------------------------------------ */ 3392 nat_t *nat_lookupredir(np, ifs) 3393 natlookup_t *np; 3394 ipf_stack_t *ifs; 3395 { 3396 fr_info_t fi; 3397 nat_t *nat; 3398 3399 bzero((char *)&fi, sizeof(fi)); 3400 if (np->nl_flags & IPN_IN) { 3401 fi.fin_data[0] = ntohs(np->nl_realport); 3402 fi.fin_data[1] = ntohs(np->nl_outport); 3403 } else { 3404 fi.fin_data[0] = ntohs(np->nl_inport); 3405 fi.fin_data[1] = ntohs(np->nl_outport); 3406 } 3407 if (np->nl_flags & IPN_TCP) 3408 fi.fin_p = IPPROTO_TCP; 3409 else if (np->nl_flags & IPN_UDP) 3410 fi.fin_p = IPPROTO_UDP; 3411 else if (np->nl_flags & (IPN_ICMPERR|IPN_ICMPQUERY)) 3412 fi.fin_p = IPPROTO_ICMP; 3413 3414 fi.fin_ifs = ifs; 3415 /* 3416 * We can do two sorts of lookups: 3417 * - IPN_IN: we have the `real' and `out' address, look for `in'. 3418 * - default: we have the `in' and `out' address, look for `real'. 3419 */ 3420 if (np->nl_flags & IPN_IN) { 3421 if ((nat = nat_inlookup(&fi, np->nl_flags, fi.fin_p, 3422 np->nl_realip, np->nl_outip))) { 3423 np->nl_inip = nat->nat_inip; 3424 np->nl_inport = nat->nat_inport; 3425 } 3426 } else { 3427 /* 3428 * If nl_inip is non null, this is a lookup based on the real 3429 * ip address. Else, we use the fake. 3430 */ 3431 if ((nat = nat_outlookup(&fi, np->nl_flags, fi.fin_p, 3432 np->nl_inip, np->nl_outip))) { 3433 3434 if ((np->nl_flags & IPN_FINDFORWARD) != 0) { 3435 fr_info_t fin; 3436 bzero((char *)&fin, sizeof(fin)); 3437 fin.fin_p = nat->nat_p; 3438 fin.fin_data[0] = ntohs(nat->nat_outport); 3439 fin.fin_data[1] = ntohs(nat->nat_oport); 3440 fin.fin_ifs = ifs; 3441 if (nat_inlookup(&fin, np->nl_flags, fin.fin_p, 3442 nat->nat_outip, 3443 nat->nat_oip) != NULL) { 3444 np->nl_flags &= ~IPN_FINDFORWARD; 3445 } 3446 } 3447 3448 np->nl_realip = nat->nat_outip; 3449 np->nl_realport = nat->nat_outport; 3450 } 3451 } 3452 3453 return nat; 3454 } 3455 3456 3457 /* ------------------------------------------------------------------------ */ 3458 /* Function: nat_match */ 3459 /* Returns: int - 0 == no match, 1 == match */ 3460 /* Parameters: fin(I) - pointer to packet information */ 3461 /* np(I) - pointer to NAT rule */ 3462 /* */ 3463 /* Pull the matching of a packet against a NAT rule out of that complex */ 3464 /* loop inside fr_checknatin() and lay it out properly in its own function. */ 3465 /* ------------------------------------------------------------------------ */ 3466 static int nat_match(fin, np) 3467 fr_info_t *fin; 3468 ipnat_t *np; 3469 { 3470 frtuc_t *ft; 3471 3472 if (fin->fin_v != 4) 3473 return 0; 3474 3475 if (np->in_p && fin->fin_p != np->in_p) 3476 return 0; 3477 3478 if (fin->fin_out) { 3479 if (!(np->in_redir & (NAT_MAP|NAT_MAPBLK))) 3480 return 0; 3481 if (((fin->fin_fi.fi_saddr & np->in_inmsk) != np->in_inip) 3482 ^ ((np->in_flags & IPN_NOTSRC) != 0)) 3483 return 0; 3484 if (((fin->fin_fi.fi_daddr & np->in_srcmsk) != np->in_srcip) 3485 ^ ((np->in_flags & IPN_NOTDST) != 0)) 3486 return 0; 3487 } else { 3488 if (!(np->in_redir & NAT_REDIRECT)) 3489 return 0; 3490 if (((fin->fin_fi.fi_saddr & np->in_srcmsk) != np->in_srcip) 3491 ^ ((np->in_flags & IPN_NOTSRC) != 0)) 3492 return 0; 3493 if (((fin->fin_fi.fi_daddr & np->in_outmsk) != np->in_outip) 3494 ^ ((np->in_flags & IPN_NOTDST) != 0)) 3495 return 0; 3496 } 3497 3498 ft = &np->in_tuc; 3499 if (!(fin->fin_flx & FI_TCPUDP) || 3500 (fin->fin_flx & (FI_SHORT|FI_FRAGBODY))) { 3501 if (ft->ftu_scmp || ft->ftu_dcmp) 3502 return 0; 3503 return 1; 3504 } 3505 3506 return fr_tcpudpchk(fin, ft); 3507 } 3508 3509 3510 /* ------------------------------------------------------------------------ */ 3511 /* Function: nat_update */ 3512 /* Returns: Nil */ 3513 /* Parameters: nat(I) - pointer to NAT structure */ 3514 /* np(I) - pointer to NAT rule */ 3515 /* */ 3516 /* Updates the lifetime of a NAT table entry for non-TCP packets. Must be */ 3517 /* called with fin_rev updated - i.e. after calling nat_proto(). */ 3518 /* ------------------------------------------------------------------------ */ 3519 void nat_update(fin, nat, np) 3520 fr_info_t *fin; 3521 nat_t *nat; 3522 ipnat_t *np; 3523 { 3524 ipftq_t *ifq, *ifq2; 3525 ipftqent_t *tqe; 3526 ipf_stack_t *ifs = fin->fin_ifs; 3527 3528 MUTEX_ENTER(&nat->nat_lock); 3529 tqe = &nat->nat_tqe; 3530 ifq = tqe->tqe_ifq; 3531 3532 /* 3533 * We allow over-riding of NAT timeouts from NAT rules, even for 3534 * TCP, however, if it is TCP and there is no rule timeout set, 3535 * then do not update the timeout here. 3536 */ 3537 if (np != NULL) 3538 ifq2 = np->in_tqehead[fin->fin_rev]; 3539 else 3540 ifq2 = NULL; 3541 3542 if (nat->nat_p == IPPROTO_TCP && ifq2 == NULL) { 3543 (void) fr_tcp_age(&nat->nat_tqe, fin, ifs->ifs_nat_tqb, 0); 3544 } else { 3545 if (ifq2 == NULL) { 3546 if (nat->nat_p == IPPROTO_UDP) 3547 ifq2 = &ifs->ifs_nat_udptq; 3548 else if (nat->nat_p == IPPROTO_ICMP) 3549 ifq2 = &ifs->ifs_nat_icmptq; 3550 else 3551 ifq2 = &ifs->ifs_nat_iptq; 3552 } 3553 3554 fr_movequeue(tqe, ifq, ifq2, ifs); 3555 } 3556 MUTEX_EXIT(&nat->nat_lock); 3557 } 3558 3559 3560 /* ------------------------------------------------------------------------ */ 3561 /* Function: fr_checknatout */ 3562 /* Returns: int - -1 == packet failed NAT checks so block it, */ 3563 /* 0 == no packet translation occurred, */ 3564 /* 1 == packet was successfully translated. */ 3565 /* Parameters: fin(I) - pointer to packet information */ 3566 /* passp(I) - pointer to filtering result flags */ 3567 /* */ 3568 /* Check to see if an outcoming packet should be changed. ICMP packets are */ 3569 /* first checked to see if they match an existing entry (if an error), */ 3570 /* otherwise a search of the current NAT table is made. If neither results */ 3571 /* in a match then a search for a matching NAT rule is made. Create a new */ 3572 /* NAT entry if a we matched a NAT rule. Lastly, actually change the */ 3573 /* packet header(s) as required. */ 3574 /* ------------------------------------------------------------------------ */ 3575 int fr_checknatout(fin, passp) 3576 fr_info_t *fin; 3577 u_32_t *passp; 3578 { 3579 struct ifnet *ifp, *sifp; 3580 icmphdr_t *icmp = NULL; 3581 tcphdr_t *tcp = NULL; 3582 int rval, natfailed; 3583 ipnat_t *np = NULL; 3584 u_int nflags = 0; 3585 u_32_t ipa, iph; 3586 int natadd = 1; 3587 frentry_t *fr; 3588 nat_t *nat; 3589 ipf_stack_t *ifs = fin->fin_ifs; 3590 3591 if (ifs->ifs_nat_stats.ns_rules == 0 || ifs->ifs_fr_nat_lock != 0) 3592 return 0; 3593 3594 natfailed = 0; 3595 fr = fin->fin_fr; 3596 sifp = fin->fin_ifp; 3597 if ((fr != NULL) && !(fr->fr_flags & FR_DUP) && 3598 fr->fr_tifs[fin->fin_rev].fd_ifp && 3599 fr->fr_tifs[fin->fin_rev].fd_ifp != (void *)-1) 3600 fin->fin_ifp = fr->fr_tifs[fin->fin_rev].fd_ifp; 3601 ifp = fin->fin_ifp; 3602 3603 if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) { 3604 switch (fin->fin_p) 3605 { 3606 case IPPROTO_TCP : 3607 nflags = IPN_TCP; 3608 break; 3609 case IPPROTO_UDP : 3610 nflags = IPN_UDP; 3611 break; 3612 case IPPROTO_ICMP : 3613 icmp = fin->fin_dp; 3614 3615 /* 3616 * This is an incoming packet, so the destination is 3617 * the icmp_id and the source port equals 0 3618 */ 3619 if (nat_icmpquerytype4(icmp->icmp_type)) 3620 nflags = IPN_ICMPQUERY; 3621 break; 3622 default : 3623 break; 3624 } 3625 3626 if ((nflags & IPN_TCPUDP)) 3627 tcp = fin->fin_dp; 3628 } 3629 3630 ipa = fin->fin_saddr; 3631 3632 READ_ENTER(&ifs->ifs_ipf_nat); 3633 3634 if ((fin->fin_p == IPPROTO_ICMP) && !(nflags & IPN_ICMPQUERY) && 3635 (nat = nat_icmperror(fin, &nflags, NAT_OUTBOUND))) 3636 /*EMPTY*/; 3637 else if ((fin->fin_flx & FI_FRAG) && (nat = fr_nat_knownfrag(fin))) 3638 natadd = 0; 3639 else if ((nat = nat_outlookup(fin, nflags|NAT_SEARCH, (u_int)fin->fin_p, 3640 fin->fin_src, fin->fin_dst))) { 3641 nflags = nat->nat_flags; 3642 } else { 3643 u_32_t hv, msk, nmsk; 3644 3645 /* 3646 * If there is no current entry in the nat table for this IP#, 3647 * create one for it (if there is a matching rule). 3648 */ 3649 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 3650 msk = 0xffffffff; 3651 nmsk = ifs->ifs_nat_masks; 3652 WRITE_ENTER(&ifs->ifs_ipf_nat); 3653 maskloop: 3654 iph = ipa & htonl(msk); 3655 hv = NAT_HASH_FN(iph, 0, ifs->ifs_ipf_natrules_sz); 3656 for (np = ifs->ifs_nat_rules[hv]; np; np = np->in_mnext) 3657 { 3658 if ((np->in_ifps[1] && (np->in_ifps[1] != ifp))) 3659 continue; 3660 if (np->in_v != fin->fin_v) 3661 continue; 3662 if (np->in_p && (np->in_p != fin->fin_p)) 3663 continue; 3664 if ((np->in_flags & IPN_RF) && !(np->in_flags & nflags)) 3665 continue; 3666 if (np->in_flags & IPN_FILTER) { 3667 if (!nat_match(fin, np)) 3668 continue; 3669 } else if ((ipa & np->in_inmsk) != np->in_inip) 3670 continue; 3671 3672 if ((fr != NULL) && 3673 !fr_matchtag(&np->in_tag, &fr->fr_nattag)) 3674 continue; 3675 3676 if (*np->in_plabel != '\0') { 3677 if (((np->in_flags & IPN_FILTER) == 0) && 3678 (np->in_dport != tcp->th_dport)) 3679 continue; 3680 if (appr_ok(fin, tcp, np) == 0) 3681 continue; 3682 } 3683 3684 if ((nat = nat_new(fin, np, NULL, nflags, 3685 NAT_OUTBOUND))) { 3686 np->in_hits++; 3687 break; 3688 } else 3689 natfailed = -1; 3690 } 3691 if ((np == NULL) && (nmsk != 0)) { 3692 while (nmsk) { 3693 msk <<= 1; 3694 if (nmsk & 0x80000000) 3695 break; 3696 nmsk <<= 1; 3697 } 3698 if (nmsk != 0) { 3699 nmsk <<= 1; 3700 goto maskloop; 3701 } 3702 } 3703 MUTEX_DOWNGRADE(&ifs->ifs_ipf_nat); 3704 } 3705 3706 if (nat != NULL) { 3707 rval = fr_natout(fin, nat, natadd, nflags); 3708 if (rval == 1) { 3709 MUTEX_ENTER(&nat->nat_lock); 3710 nat->nat_ref++; 3711 MUTEX_EXIT(&nat->nat_lock); 3712 nat->nat_touched = ifs->ifs_fr_ticks; 3713 fin->fin_nat = nat; 3714 } 3715 } else 3716 rval = natfailed; 3717 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 3718 3719 if (rval == -1) { 3720 if (passp != NULL) 3721 *passp = FR_BLOCK; 3722 fin->fin_flx |= FI_BADNAT; 3723 } 3724 fin->fin_ifp = sifp; 3725 return rval; 3726 } 3727 3728 /* ------------------------------------------------------------------------ */ 3729 /* Function: fr_natout */ 3730 /* Returns: int - -1 == packet failed NAT checks so block it, */ 3731 /* 1 == packet was successfully translated. */ 3732 /* Parameters: fin(I) - pointer to packet information */ 3733 /* nat(I) - pointer to NAT structure */ 3734 /* natadd(I) - flag indicating if it is safe to add frag cache */ 3735 /* nflags(I) - NAT flags set for this packet */ 3736 /* */ 3737 /* Translate a packet coming "out" on an interface. */ 3738 /* ------------------------------------------------------------------------ */ 3739 int fr_natout(fin, nat, natadd, nflags) 3740 fr_info_t *fin; 3741 nat_t *nat; 3742 int natadd; 3743 u_32_t nflags; 3744 { 3745 icmphdr_t *icmp; 3746 u_short *csump; 3747 u_32_t sumd; 3748 tcphdr_t *tcp; 3749 ipnat_t *np; 3750 int i; 3751 ipf_stack_t *ifs = fin->fin_ifs; 3752 3753 #if SOLARIS && defined(_KERNEL) 3754 net_data_t net_data_p; 3755 if (fin->fin_v == 4) 3756 net_data_p = ifs->ifs_ipf_ipv4; 3757 else 3758 net_data_p = ifs->ifs_ipf_ipv6; 3759 #endif 3760 3761 tcp = NULL; 3762 icmp = NULL; 3763 csump = NULL; 3764 np = nat->nat_ptr; 3765 3766 if ((natadd != 0) && (fin->fin_flx & FI_FRAG)) 3767 (void) fr_nat_newfrag(fin, 0, nat); 3768 3769 MUTEX_ENTER(&nat->nat_lock); 3770 nat->nat_bytes[1] += fin->fin_plen; 3771 nat->nat_pkts[1]++; 3772 MUTEX_EXIT(&nat->nat_lock); 3773 3774 /* 3775 * Fix up checksums, not by recalculating them, but 3776 * simply computing adjustments. 3777 * This is only done for STREAMS based IP implementations where the 3778 * checksum has already been calculated by IP. In all other cases, 3779 * IPFilter is called before the checksum needs calculating so there 3780 * is no call to modify whatever is in the header now. 3781 */ 3782 ASSERT(fin->fin_m != NULL); 3783 if (fin->fin_v == 4 && !NET_IS_HCK_L3_FULL(net_data_p, fin->fin_m)) { 3784 if (nflags == IPN_ICMPERR) { 3785 u_32_t s1, s2; 3786 3787 s1 = LONG_SUM(ntohl(fin->fin_saddr)); 3788 s2 = LONG_SUM(ntohl(nat->nat_outip.s_addr)); 3789 CALC_SUMD(s1, s2, sumd); 3790 3791 fix_outcksum(&fin->fin_ip->ip_sum, sumd); 3792 } 3793 #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) || \ 3794 defined(linux) || defined(BRIDGE_IPF) 3795 else { 3796 /* 3797 * Strictly speaking, this isn't necessary on BSD 3798 * kernels because they do checksum calculation after 3799 * this code has run BUT if ipfilter is being used 3800 * to do NAT as a bridge, that code doesn't exist. 3801 */ 3802 if (nat->nat_dir == NAT_OUTBOUND) 3803 fix_outcksum(&fin->fin_ip->ip_sum, 3804 nat->nat_ipsumd); 3805 else 3806 fix_incksum(&fin->fin_ip->ip_sum, 3807 nat->nat_ipsumd); 3808 } 3809 #endif 3810 } 3811 3812 if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) { 3813 if ((nat->nat_outport != 0) && (nflags & IPN_TCPUDP)) { 3814 tcp = fin->fin_dp; 3815 3816 tcp->th_sport = nat->nat_outport; 3817 fin->fin_data[0] = ntohs(nat->nat_outport); 3818 } 3819 3820 if ((nat->nat_outport != 0) && (nflags & IPN_ICMPQUERY)) { 3821 icmp = fin->fin_dp; 3822 icmp->icmp_id = nat->nat_outport; 3823 } 3824 3825 csump = nat_proto(fin, nat, nflags); 3826 } 3827 3828 fin->fin_ip->ip_src = nat->nat_outip; 3829 3830 nat_update(fin, nat, np); 3831 3832 /* 3833 * The above comments do not hold for layer 4 (or higher) checksums... 3834 */ 3835 if (csump != NULL && !NET_IS_HCK_L4_FULL(net_data_p, fin->fin_m)) { 3836 if (nflags & IPN_TCPUDP && 3837 NET_IS_HCK_L4_PART(net_data_p, fin->fin_m)) 3838 sumd = nat->nat_sumd[1]; 3839 else 3840 sumd = nat->nat_sumd[0]; 3841 3842 if (nat->nat_dir == NAT_OUTBOUND) 3843 fix_outcksum(csump, sumd); 3844 else 3845 fix_incksum(csump, sumd); 3846 } 3847 #ifdef IPFILTER_SYNC 3848 ipfsync_update(SMC_NAT, fin, nat->nat_sync); 3849 #endif 3850 /* ------------------------------------------------------------- */ 3851 /* A few quick notes: */ 3852 /* Following are test conditions prior to calling the */ 3853 /* appr_check routine. */ 3854 /* */ 3855 /* A NULL tcp indicates a non TCP/UDP packet. When dealing */ 3856 /* with a redirect rule, we attempt to match the packet's */ 3857 /* source port against in_dport, otherwise we'd compare the */ 3858 /* packet's destination. */ 3859 /* ------------------------------------------------------------- */ 3860 if ((np != NULL) && (np->in_apr != NULL)) { 3861 i = appr_check(fin, nat); 3862 if (i == 0) 3863 i = 1; 3864 } else 3865 i = 1; 3866 ATOMIC_INCL(ifs->ifs_nat_stats.ns_mapped[1]); 3867 fin->fin_flx |= FI_NATED; 3868 return i; 3869 } 3870 3871 3872 /* ------------------------------------------------------------------------ */ 3873 /* Function: fr_checknatin */ 3874 /* Returns: int - -1 == packet failed NAT checks so block it, */ 3875 /* 0 == no packet translation occurred, */ 3876 /* 1 == packet was successfully translated. */ 3877 /* Parameters: fin(I) - pointer to packet information */ 3878 /* passp(I) - pointer to filtering result flags */ 3879 /* */ 3880 /* Check to see if an incoming packet should be changed. ICMP packets are */ 3881 /* first checked to see if they match an existing entry (if an error), */ 3882 /* otherwise a search of the current NAT table is made. If neither results */ 3883 /* in a match then a search for a matching NAT rule is made. Create a new */ 3884 /* NAT entry if a we matched a NAT rule. Lastly, actually change the */ 3885 /* packet header(s) as required. */ 3886 /* ------------------------------------------------------------------------ */ 3887 int fr_checknatin(fin, passp) 3888 fr_info_t *fin; 3889 u_32_t *passp; 3890 { 3891 u_int nflags, natadd; 3892 int rval, natfailed; 3893 struct ifnet *ifp; 3894 struct in_addr in; 3895 icmphdr_t *icmp; 3896 tcphdr_t *tcp; 3897 u_short dport; 3898 ipnat_t *np; 3899 nat_t *nat; 3900 u_32_t iph; 3901 ipf_stack_t *ifs = fin->fin_ifs; 3902 3903 if (ifs->ifs_nat_stats.ns_rules == 0 || ifs->ifs_fr_nat_lock != 0) 3904 return 0; 3905 3906 tcp = NULL; 3907 icmp = NULL; 3908 dport = 0; 3909 natadd = 1; 3910 nflags = 0; 3911 natfailed = 0; 3912 ifp = fin->fin_ifp; 3913 3914 if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) { 3915 switch (fin->fin_p) 3916 { 3917 case IPPROTO_TCP : 3918 nflags = IPN_TCP; 3919 break; 3920 case IPPROTO_UDP : 3921 nflags = IPN_UDP; 3922 break; 3923 case IPPROTO_ICMP : 3924 icmp = fin->fin_dp; 3925 3926 /* 3927 * This is an incoming packet, so the destination is 3928 * the icmp_id and the source port equals 0 3929 */ 3930 if (nat_icmpquerytype4(icmp->icmp_type)) { 3931 nflags = IPN_ICMPQUERY; 3932 dport = icmp->icmp_id; 3933 } break; 3934 default : 3935 break; 3936 } 3937 3938 if ((nflags & IPN_TCPUDP)) { 3939 tcp = fin->fin_dp; 3940 dport = tcp->th_dport; 3941 } 3942 } 3943 3944 in = fin->fin_dst; 3945 3946 READ_ENTER(&ifs->ifs_ipf_nat); 3947 3948 if ((fin->fin_p == IPPROTO_ICMP) && !(nflags & IPN_ICMPQUERY) && 3949 (nat = nat_icmperror(fin, &nflags, NAT_INBOUND))) 3950 /*EMPTY*/; 3951 else if ((fin->fin_flx & FI_FRAG) && (nat = fr_nat_knownfrag(fin))) 3952 natadd = 0; 3953 else if ((nat = nat_inlookup(fin, nflags|NAT_SEARCH, (u_int)fin->fin_p, 3954 fin->fin_src, in))) { 3955 nflags = nat->nat_flags; 3956 } else { 3957 u_32_t hv, msk, rmsk; 3958 3959 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 3960 rmsk = ifs->ifs_rdr_masks; 3961 msk = 0xffffffff; 3962 WRITE_ENTER(&ifs->ifs_ipf_nat); 3963 /* 3964 * If there is no current entry in the nat table for this IP#, 3965 * create one for it (if there is a matching rule). 3966 */ 3967 maskloop: 3968 iph = in.s_addr & htonl(msk); 3969 hv = NAT_HASH_FN(iph, 0, ifs->ifs_ipf_rdrrules_sz); 3970 for (np = ifs->ifs_rdr_rules[hv]; np; np = np->in_rnext) { 3971 if (np->in_ifps[0] && (np->in_ifps[0] != ifp)) 3972 continue; 3973 if (np->in_v != fin->fin_v) 3974 continue; 3975 if (np->in_p && (np->in_p != fin->fin_p)) 3976 continue; 3977 if ((np->in_flags & IPN_RF) && !(np->in_flags & nflags)) 3978 continue; 3979 if (np->in_flags & IPN_FILTER) { 3980 if (!nat_match(fin, np)) 3981 continue; 3982 } else { 3983 if ((in.s_addr & np->in_outmsk) != np->in_outip) 3984 continue; 3985 if (np->in_pmin && 3986 ((ntohs(np->in_pmax) < ntohs(dport)) || 3987 (ntohs(dport) < ntohs(np->in_pmin)))) 3988 continue; 3989 } 3990 3991 if (*np->in_plabel != '\0') { 3992 if (!appr_ok(fin, tcp, np)) { 3993 continue; 3994 } 3995 } 3996 3997 nat = nat_new(fin, np, NULL, nflags, NAT_INBOUND); 3998 if (nat != NULL) { 3999 np->in_hits++; 4000 break; 4001 } else 4002 natfailed = -1; 4003 } 4004 4005 if ((np == NULL) && (rmsk != 0)) { 4006 while (rmsk) { 4007 msk <<= 1; 4008 if (rmsk & 0x80000000) 4009 break; 4010 rmsk <<= 1; 4011 } 4012 if (rmsk != 0) { 4013 rmsk <<= 1; 4014 goto maskloop; 4015 } 4016 } 4017 MUTEX_DOWNGRADE(&ifs->ifs_ipf_nat); 4018 } 4019 if (nat != NULL) { 4020 rval = fr_natin(fin, nat, natadd, nflags); 4021 if (rval == 1) { 4022 MUTEX_ENTER(&nat->nat_lock); 4023 nat->nat_ref++; 4024 MUTEX_EXIT(&nat->nat_lock); 4025 nat->nat_touched = ifs->ifs_fr_ticks; 4026 fin->fin_nat = nat; 4027 fin->fin_state = nat->nat_state; 4028 } 4029 } else 4030 rval = natfailed; 4031 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 4032 4033 if (rval == -1) { 4034 if (passp != NULL) 4035 *passp = FR_BLOCK; 4036 fin->fin_flx |= FI_BADNAT; 4037 } 4038 return rval; 4039 } 4040 4041 4042 /* ------------------------------------------------------------------------ */ 4043 /* Function: fr_natin */ 4044 /* Returns: int - -1 == packet failed NAT checks so block it, */ 4045 /* 1 == packet was successfully translated. */ 4046 /* Parameters: fin(I) - pointer to packet information */ 4047 /* nat(I) - pointer to NAT structure */ 4048 /* natadd(I) - flag indicating if it is safe to add frag cache */ 4049 /* nflags(I) - NAT flags set for this packet */ 4050 /* Locks Held: ipf_nat (READ) */ 4051 /* */ 4052 /* Translate a packet coming "in" on an interface. */ 4053 /* ------------------------------------------------------------------------ */ 4054 int fr_natin(fin, nat, natadd, nflags) 4055 fr_info_t *fin; 4056 nat_t *nat; 4057 int natadd; 4058 u_32_t nflags; 4059 { 4060 icmphdr_t *icmp; 4061 u_short *csump, *csump1; 4062 u_32_t sumd; 4063 tcphdr_t *tcp; 4064 ipnat_t *np; 4065 int i; 4066 ipf_stack_t *ifs = fin->fin_ifs; 4067 4068 #if SOLARIS && defined(_KERNEL) 4069 net_data_t net_data_p; 4070 if (fin->fin_v == 4) 4071 net_data_p = ifs->ifs_ipf_ipv4; 4072 else 4073 net_data_p = ifs->ifs_ipf_ipv6; 4074 #endif 4075 4076 tcp = NULL; 4077 csump = NULL; 4078 np = nat->nat_ptr; 4079 fin->fin_fr = nat->nat_fr; 4080 4081 if ((natadd != 0) && (fin->fin_flx & FI_FRAG)) 4082 (void) fr_nat_newfrag(fin, 0, nat); 4083 4084 if (np != NULL) { 4085 4086 /* ------------------------------------------------------------- */ 4087 /* A few quick notes: */ 4088 /* Following are test conditions prior to calling the */ 4089 /* appr_check routine. */ 4090 /* */ 4091 /* A NULL tcp indicates a non TCP/UDP packet. When dealing */ 4092 /* with a map rule, we attempt to match the packet's */ 4093 /* source port against in_dport, otherwise we'd compare the */ 4094 /* packet's destination. */ 4095 /* ------------------------------------------------------------- */ 4096 if (np->in_apr != NULL) { 4097 i = appr_check(fin, nat); 4098 if (i == -1) { 4099 return -1; 4100 } 4101 } 4102 } 4103 4104 #ifdef IPFILTER_SYNC 4105 ipfsync_update(SMC_NAT, fin, nat->nat_sync); 4106 #endif 4107 4108 MUTEX_ENTER(&nat->nat_lock); 4109 nat->nat_bytes[0] += fin->fin_plen; 4110 nat->nat_pkts[0]++; 4111 MUTEX_EXIT(&nat->nat_lock); 4112 4113 fin->fin_ip->ip_dst = nat->nat_inip; 4114 fin->fin_fi.fi_daddr = nat->nat_inip.s_addr; 4115 if (nflags & IPN_TCPUDP) 4116 tcp = fin->fin_dp; 4117 4118 /* 4119 * Fix up checksums, not by recalculating them, but 4120 * simply computing adjustments. 4121 * Why only do this for some platforms on inbound packets ? 4122 * Because for those that it is done, IP processing is yet to happen 4123 * and so the IPv4 header checksum has not yet been evaluated. 4124 * Perhaps it should always be done for the benefit of things like 4125 * fast forwarding (so that it doesn't need to be recomputed) but with 4126 * header checksum offloading, perhaps it is a moot point. 4127 */ 4128 #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) || \ 4129 defined(__osf__) || defined(linux) 4130 if (nat->nat_dir == NAT_OUTBOUND) 4131 fix_incksum(&fin->fin_ip->ip_sum, nat->nat_ipsumd); 4132 else 4133 fix_outcksum(&fin->fin_ip->ip_sum, nat->nat_ipsumd); 4134 #endif 4135 4136 if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) { 4137 if ((nat->nat_inport != 0) && (nflags & IPN_TCPUDP)) { 4138 tcp->th_dport = nat->nat_inport; 4139 fin->fin_data[1] = ntohs(nat->nat_inport); 4140 } 4141 4142 4143 if ((nat->nat_inport != 0) && (nflags & IPN_ICMPQUERY)) { 4144 icmp = fin->fin_dp; 4145 4146 icmp->icmp_id = nat->nat_inport; 4147 } 4148 4149 csump = nat_proto(fin, nat, nflags); 4150 } 4151 4152 nat_update(fin, nat, np); 4153 4154 #if SOLARIS && defined(_KERNEL) 4155 if (nflags & IPN_TCPUDP && 4156 NET_IS_HCK_L4_PART(net_data_p, fin->fin_m)) { 4157 sumd = nat->nat_sumd[1]; 4158 csump1 = &(fin->fin_m->b_datap->db_struioun.cksum.cksum_val.u16); 4159 if (csump1 != NULL) { 4160 if (nat->nat_dir == NAT_OUTBOUND) 4161 fix_incksum(csump1, sumd); 4162 else 4163 fix_outcksum(csump1, sumd); 4164 } 4165 } else 4166 #endif 4167 sumd = nat->nat_sumd[0]; 4168 4169 /* 4170 * Inbound packets always need to have their address adjusted in case 4171 * code following this validates it. 4172 */ 4173 if (csump != NULL) { 4174 if (nat->nat_dir == NAT_OUTBOUND) 4175 fix_incksum(csump, sumd); 4176 else 4177 fix_outcksum(csump, sumd); 4178 } 4179 ATOMIC_INCL(ifs->ifs_nat_stats.ns_mapped[0]); 4180 fin->fin_flx |= FI_NATED; 4181 if (np != NULL && np->in_tag.ipt_num[0] != 0) 4182 fin->fin_nattag = &np->in_tag; 4183 return 1; 4184 } 4185 4186 4187 /* ------------------------------------------------------------------------ */ 4188 /* Function: nat_proto */ 4189 /* Returns: u_short* - pointer to transport header checksum to update, */ 4190 /* NULL if the transport protocol is not recognised */ 4191 /* as needing a checksum update. */ 4192 /* Parameters: fin(I) - pointer to packet information */ 4193 /* nat(I) - pointer to NAT structure */ 4194 /* nflags(I) - NAT flags set for this packet */ 4195 /* */ 4196 /* Return the pointer to the checksum field for each protocol so understood.*/ 4197 /* If support for making other changes to a protocol header is required, */ 4198 /* that is not strictly 'address' translation, such as clamping the MSS in */ 4199 /* TCP down to a specific value, then do it from here. */ 4200 /* ------------------------------------------------------------------------ */ 4201 u_short *nat_proto(fin, nat, nflags) 4202 fr_info_t *fin; 4203 nat_t *nat; 4204 u_int nflags; 4205 { 4206 icmphdr_t *icmp; 4207 u_short *csump; 4208 tcphdr_t *tcp; 4209 udphdr_t *udp; 4210 4211 csump = NULL; 4212 if (fin->fin_out == 0) { 4213 fin->fin_rev = (nat->nat_dir == NAT_OUTBOUND); 4214 } else { 4215 fin->fin_rev = (nat->nat_dir == NAT_INBOUND); 4216 } 4217 4218 switch (fin->fin_p) 4219 { 4220 case IPPROTO_TCP : 4221 tcp = fin->fin_dp; 4222 4223 csump = &tcp->th_sum; 4224 4225 /* 4226 * Do a MSS CLAMPING on a SYN packet, 4227 * only deal IPv4 for now. 4228 */ 4229 if ((nat->nat_mssclamp != 0) && (tcp->th_flags & TH_SYN) != 0) 4230 nat_mssclamp(tcp, nat->nat_mssclamp, csump); 4231 4232 break; 4233 4234 case IPPROTO_UDP : 4235 udp = fin->fin_dp; 4236 4237 if (udp->uh_sum) 4238 csump = &udp->uh_sum; 4239 break; 4240 4241 case IPPROTO_ICMP : 4242 icmp = fin->fin_dp; 4243 4244 if ((nflags & IPN_ICMPQUERY) != 0) { 4245 if (icmp->icmp_cksum != 0) 4246 csump = &icmp->icmp_cksum; 4247 } 4248 break; 4249 } 4250 return csump; 4251 } 4252 4253 4254 /* ------------------------------------------------------------------------ */ 4255 /* Function: fr_natunload */ 4256 /* Returns: Nil */ 4257 /* Parameters: Nil */ 4258 /* */ 4259 /* Free all memory used by NAT structures allocated at runtime. */ 4260 /* ------------------------------------------------------------------------ */ 4261 void fr_natunload(ifs) 4262 ipf_stack_t *ifs; 4263 { 4264 ipftq_t *ifq, *ifqnext; 4265 4266 (void) nat_clearlist(ifs); 4267 (void) nat_flushtable(ifs); 4268 4269 /* 4270 * Proxy timeout queues are not cleaned here because although they 4271 * exist on the NAT list, appr_unload is called after fr_natunload 4272 * and the proxies actually are responsible for them being created. 4273 * Should the proxy timeouts have their own list? There's no real 4274 * justification as this is the only complication. 4275 */ 4276 for (ifq = ifs->ifs_nat_utqe; ifq != NULL; ifq = ifqnext) { 4277 ifqnext = ifq->ifq_next; 4278 if (((ifq->ifq_flags & IFQF_PROXY) == 0) && 4279 (fr_deletetimeoutqueue(ifq) == 0)) 4280 fr_freetimeoutqueue(ifq, ifs); 4281 } 4282 4283 if (ifs->ifs_nat_table[0] != NULL) { 4284 KFREES(ifs->ifs_nat_table[0], 4285 sizeof(nat_t *) * ifs->ifs_ipf_nattable_sz); 4286 ifs->ifs_nat_table[0] = NULL; 4287 } 4288 if (ifs->ifs_nat_table[1] != NULL) { 4289 KFREES(ifs->ifs_nat_table[1], 4290 sizeof(nat_t *) * ifs->ifs_ipf_nattable_sz); 4291 ifs->ifs_nat_table[1] = NULL; 4292 } 4293 if (ifs->ifs_nat_rules != NULL) { 4294 KFREES(ifs->ifs_nat_rules, 4295 sizeof(ipnat_t *) * ifs->ifs_ipf_natrules_sz); 4296 ifs->ifs_nat_rules = NULL; 4297 } 4298 if (ifs->ifs_rdr_rules != NULL) { 4299 KFREES(ifs->ifs_rdr_rules, 4300 sizeof(ipnat_t *) * ifs->ifs_ipf_rdrrules_sz); 4301 ifs->ifs_rdr_rules = NULL; 4302 } 4303 if (ifs->ifs_maptable != NULL) { 4304 KFREES(ifs->ifs_maptable, 4305 sizeof(hostmap_t *) * ifs->ifs_ipf_hostmap_sz); 4306 ifs->ifs_maptable = NULL; 4307 } 4308 if (ifs->ifs_nat_stats.ns_bucketlen[0] != NULL) { 4309 KFREES(ifs->ifs_nat_stats.ns_bucketlen[0], 4310 sizeof(u_long *) * ifs->ifs_ipf_nattable_sz); 4311 ifs->ifs_nat_stats.ns_bucketlen[0] = NULL; 4312 } 4313 if (ifs->ifs_nat_stats.ns_bucketlen[1] != NULL) { 4314 KFREES(ifs->ifs_nat_stats.ns_bucketlen[1], 4315 sizeof(u_long *) * ifs->ifs_ipf_nattable_sz); 4316 ifs->ifs_nat_stats.ns_bucketlen[1] = NULL; 4317 } 4318 4319 if (ifs->ifs_fr_nat_maxbucket_reset == 1) 4320 ifs->ifs_fr_nat_maxbucket = 0; 4321 4322 if (ifs->ifs_fr_nat_init == 1) { 4323 ifs->ifs_fr_nat_init = 0; 4324 fr_sttab_destroy(ifs->ifs_nat_tqb); 4325 4326 RW_DESTROY(&ifs->ifs_ipf_natfrag); 4327 RW_DESTROY(&ifs->ifs_ipf_nat); 4328 4329 MUTEX_DESTROY(&ifs->ifs_ipf_nat_new); 4330 MUTEX_DESTROY(&ifs->ifs_ipf_natio); 4331 4332 MUTEX_DESTROY(&ifs->ifs_nat_udptq.ifq_lock); 4333 MUTEX_DESTROY(&ifs->ifs_nat_icmptq.ifq_lock); 4334 MUTEX_DESTROY(&ifs->ifs_nat_iptq.ifq_lock); 4335 } 4336 } 4337 4338 4339 /* ------------------------------------------------------------------------ */ 4340 /* Function: fr_natexpire */ 4341 /* Returns: Nil */ 4342 /* Parameters: Nil */ 4343 /* */ 4344 /* Check all of the timeout queues for entries at the top which need to be */ 4345 /* expired. */ 4346 /* ------------------------------------------------------------------------ */ 4347 void fr_natexpire(ifs) 4348 ipf_stack_t *ifs; 4349 { 4350 ipftq_t *ifq, *ifqnext; 4351 ipftqent_t *tqe, *tqn; 4352 int i; 4353 SPL_INT(s); 4354 4355 SPL_NET(s); 4356 WRITE_ENTER(&ifs->ifs_ipf_nat); 4357 for (ifq = ifs->ifs_nat_tqb, i = 0; ifq != NULL; ifq = ifq->ifq_next) { 4358 for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); i++) { 4359 if (tqe->tqe_die > ifs->ifs_fr_ticks) 4360 break; 4361 tqn = tqe->tqe_next; 4362 nat_delete(tqe->tqe_parent, NL_EXPIRE, ifs); 4363 } 4364 } 4365 4366 for (ifq = ifs->ifs_nat_utqe; ifq != NULL; ifq = ifqnext) { 4367 ifqnext = ifq->ifq_next; 4368 4369 for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); i++) { 4370 if (tqe->tqe_die > ifs->ifs_fr_ticks) 4371 break; 4372 tqn = tqe->tqe_next; 4373 nat_delete(tqe->tqe_parent, NL_EXPIRE, ifs); 4374 } 4375 } 4376 4377 for (ifq = ifs->ifs_nat_utqe; ifq != NULL; ifq = ifqnext) { 4378 ifqnext = ifq->ifq_next; 4379 4380 if (((ifq->ifq_flags & IFQF_DELETE) != 0) && 4381 (ifq->ifq_ref == 0)) { 4382 fr_freetimeoutqueue(ifq, ifs); 4383 } 4384 } 4385 4386 if (ifs->ifs_nat_doflush != 0) { 4387 (void) nat_extraflush(2, ifs); 4388 ifs->ifs_nat_doflush = 0; 4389 } 4390 4391 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 4392 SPL_X(s); 4393 } 4394 4395 4396 /* ------------------------------------------------------------------------ */ 4397 /* Function: fr_nataddrsync */ 4398 /* Returns: Nil */ 4399 /* Parameters: ifp(I) - pointer to network interface */ 4400 /* addr(I) - pointer to new network address */ 4401 /* */ 4402 /* Walk through all of the currently active NAT sessions, looking for those */ 4403 /* which need to have their translated address updated (where the interface */ 4404 /* matches the one passed in) and change it, recalculating the checksum sum */ 4405 /* difference too. */ 4406 /* ------------------------------------------------------------------------ */ 4407 void fr_nataddrsync(ifp, addr, ifs) 4408 void *ifp; 4409 struct in_addr *addr; 4410 ipf_stack_t *ifs; 4411 { 4412 u_32_t sum1, sum2, sumd; 4413 nat_t *nat; 4414 ipnat_t *np; 4415 SPL_INT(s); 4416 4417 if (ifs->ifs_fr_running <= 0) 4418 return; 4419 4420 SPL_NET(s); 4421 WRITE_ENTER(&ifs->ifs_ipf_nat); 4422 4423 if (ifs->ifs_fr_running <= 0) { 4424 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 4425 return; 4426 } 4427 4428 /* 4429 * Change IP addresses for NAT sessions for any protocol except TCP 4430 * since it will break the TCP connection anyway. The only rules 4431 * which will get changed are those which are "map ... -> 0/32", 4432 * where the rule specifies the address is taken from the interface. 4433 */ 4434 for (nat = ifs->ifs_nat_instances; nat; nat = nat->nat_next) { 4435 if (addr != NULL) { 4436 if (((ifp != NULL) && ifp != (nat->nat_ifps[0])) || 4437 ((nat->nat_flags & IPN_TCP) != 0)) 4438 continue; 4439 if (((np = nat->nat_ptr) == NULL) || 4440 (np->in_nip || (np->in_outmsk != 0xffffffff))) 4441 continue; 4442 4443 /* 4444 * Change the map-to address to be the same as the 4445 * new one. 4446 */ 4447 sum1 = nat->nat_outip.s_addr; 4448 nat->nat_outip = *addr; 4449 sum2 = nat->nat_outip.s_addr; 4450 4451 } else if (((ifp == NULL) || (ifp == nat->nat_ifps[0])) && 4452 !(nat->nat_flags & IPN_TCP) && (np = nat->nat_ptr) && 4453 (np->in_outmsk == 0xffffffff) && !np->in_nip) { 4454 struct in_addr in; 4455 4456 /* 4457 * Change the map-to address to be the same as the 4458 * new one. 4459 */ 4460 sum1 = nat->nat_outip.s_addr; 4461 if (fr_ifpaddr(4, FRI_NORMAL, nat->nat_ifps[0], 4462 &in, NULL, ifs) != -1) 4463 nat->nat_outip = in; 4464 sum2 = nat->nat_outip.s_addr; 4465 } else { 4466 continue; 4467 } 4468 4469 if (sum1 == sum2) 4470 continue; 4471 /* 4472 * Readjust the checksum adjustment to take into 4473 * account the new IP#. 4474 */ 4475 CALC_SUMD(sum1, sum2, sumd); 4476 /* XXX - dont change for TCP when solaris does 4477 * hardware checksumming. 4478 */ 4479 sumd += nat->nat_sumd[0]; 4480 nat->nat_sumd[0] = (sumd & 0xffff) + (sumd >> 16); 4481 nat->nat_sumd[1] = nat->nat_sumd[0]; 4482 } 4483 4484 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 4485 SPL_X(s); 4486 } 4487 4488 4489 /* ------------------------------------------------------------------------ */ 4490 /* Function: fr_natifpsync */ 4491 /* Returns: Nil */ 4492 /* Parameters: action(I) - how we are syncing */ 4493 /* ifp(I) - pointer to network interface */ 4494 /* name(I) - name of interface to sync to */ 4495 /* */ 4496 /* This function is used to resync the mapping of interface names and their */ 4497 /* respective 'pointers'. For "action == IPFSYNC_RESYNC", resync all */ 4498 /* interfaces by doing a new lookup of name to 'pointer'. For "action == */ 4499 /* IPFSYNC_NEWIFP", treat ifp as the new pointer value associated with */ 4500 /* "name" and for "action == IPFSYNC_OLDIFP", ifp is a pointer for which */ 4501 /* there is no longer any interface associated with it. */ 4502 /* ------------------------------------------------------------------------ */ 4503 void fr_natifpsync(action, ifp, name, ifs) 4504 int action; 4505 void *ifp; 4506 char *name; 4507 ipf_stack_t *ifs; 4508 { 4509 #if defined(_KERNEL) && !defined(MENTAT) && defined(USE_SPL) 4510 int s; 4511 #endif 4512 nat_t *nat; 4513 ipnat_t *n; 4514 4515 if (ifs->ifs_fr_running <= 0) 4516 return; 4517 4518 SPL_NET(s); 4519 WRITE_ENTER(&ifs->ifs_ipf_nat); 4520 4521 if (ifs->ifs_fr_running <= 0) { 4522 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 4523 return; 4524 } 4525 4526 switch (action) 4527 { 4528 case IPFSYNC_RESYNC : 4529 for (nat = ifs->ifs_nat_instances; nat; nat = nat->nat_next) { 4530 if ((ifp == nat->nat_ifps[0]) || 4531 (nat->nat_ifps[0] == (void *)-1)) { 4532 nat->nat_ifps[0] = 4533 fr_resolvenic(nat->nat_ifnames[0], 4, ifs); 4534 } 4535 4536 if ((ifp == nat->nat_ifps[1]) || 4537 (nat->nat_ifps[1] == (void *)-1)) { 4538 nat->nat_ifps[1] = 4539 fr_resolvenic(nat->nat_ifnames[1], 4, ifs); 4540 } 4541 } 4542 4543 for (n = ifs->ifs_nat_list; (n != NULL); n = n->in_next) { 4544 if (n->in_ifps[0] == ifp || 4545 n->in_ifps[0] == (void *)-1) { 4546 n->in_ifps[0] = 4547 fr_resolvenic(n->in_ifnames[0], 4, ifs); 4548 } 4549 if (n->in_ifps[1] == ifp || 4550 n->in_ifps[1] == (void *)-1) { 4551 n->in_ifps[1] = 4552 fr_resolvenic(n->in_ifnames[1], 4, ifs); 4553 } 4554 } 4555 break; 4556 case IPFSYNC_NEWIFP : 4557 for (nat = ifs->ifs_nat_instances; nat; nat = nat->nat_next) { 4558 if (!strncmp(name, nat->nat_ifnames[0], 4559 sizeof(nat->nat_ifnames[0]))) 4560 nat->nat_ifps[0] = ifp; 4561 if (!strncmp(name, nat->nat_ifnames[1], 4562 sizeof(nat->nat_ifnames[1]))) 4563 nat->nat_ifps[1] = ifp; 4564 } 4565 for (n = ifs->ifs_nat_list; (n != NULL); n = n->in_next) { 4566 if (!strncmp(name, n->in_ifnames[0], 4567 sizeof(n->in_ifnames[0]))) 4568 n->in_ifps[0] = ifp; 4569 if (!strncmp(name, n->in_ifnames[1], 4570 sizeof(n->in_ifnames[1]))) 4571 n->in_ifps[1] = ifp; 4572 } 4573 break; 4574 case IPFSYNC_OLDIFP : 4575 for (nat = ifs->ifs_nat_instances; nat; nat = nat->nat_next) { 4576 if (ifp == nat->nat_ifps[0]) 4577 nat->nat_ifps[0] = (void *)-1; 4578 if (ifp == nat->nat_ifps[1]) 4579 nat->nat_ifps[1] = (void *)-1; 4580 } 4581 for (n = ifs->ifs_nat_list; (n != NULL); n = n->in_next) { 4582 if (n->in_ifps[0] == ifp) 4583 n->in_ifps[0] = (void *)-1; 4584 if (n->in_ifps[1] == ifp) 4585 n->in_ifps[1] = (void *)-1; 4586 } 4587 break; 4588 } 4589 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 4590 SPL_X(s); 4591 } 4592 4593 4594 /* ------------------------------------------------------------------------ */ 4595 /* Function: nat_icmpquerytype4 */ 4596 /* Returns: int - 1 == success, 0 == failure */ 4597 /* Parameters: icmptype(I) - ICMP type number */ 4598 /* */ 4599 /* Tests to see if the ICMP type number passed is a query/response type or */ 4600 /* not. */ 4601 /* ------------------------------------------------------------------------ */ 4602 static INLINE int nat_icmpquerytype4(icmptype) 4603 int icmptype; 4604 { 4605 4606 /* 4607 * For the ICMP query NAT code, it is essential that both the query 4608 * and the reply match on the NAT rule. Because the NAT structure 4609 * does not keep track of the icmptype, and a single NAT structure 4610 * is used for all icmp types with the same src, dest and id, we 4611 * simply define the replies as queries as well. The funny thing is, 4612 * altough it seems silly to call a reply a query, this is exactly 4613 * as it is defined in the IPv4 specification 4614 */ 4615 4616 switch (icmptype) 4617 { 4618 4619 case ICMP_ECHOREPLY: 4620 case ICMP_ECHO: 4621 /* route aedvertisement/solliciation is currently unsupported: */ 4622 /* it would require rewriting the ICMP data section */ 4623 case ICMP_TSTAMP: 4624 case ICMP_TSTAMPREPLY: 4625 case ICMP_IREQ: 4626 case ICMP_IREQREPLY: 4627 case ICMP_MASKREQ: 4628 case ICMP_MASKREPLY: 4629 return 1; 4630 default: 4631 return 0; 4632 } 4633 } 4634 4635 4636 /* ------------------------------------------------------------------------ */ 4637 /* Function: nat_log */ 4638 /* Returns: Nil */ 4639 /* Parameters: nat(I) - pointer to NAT structure */ 4640 /* type(I) - type of log entry to create */ 4641 /* */ 4642 /* Creates a NAT log entry. */ 4643 /* ------------------------------------------------------------------------ */ 4644 void nat_log(nat, type, ifs) 4645 struct nat *nat; 4646 u_int type; 4647 ipf_stack_t *ifs; 4648 { 4649 #ifdef IPFILTER_LOG 4650 # ifndef LARGE_NAT 4651 struct ipnat *np; 4652 int rulen; 4653 # endif 4654 struct natlog natl; 4655 void *items[1]; 4656 size_t sizes[1]; 4657 int types[1]; 4658 4659 natl.nl_inip = nat->nat_inip; 4660 natl.nl_outip = nat->nat_outip; 4661 natl.nl_origip = nat->nat_oip; 4662 natl.nl_bytes[0] = nat->nat_bytes[0]; 4663 natl.nl_bytes[1] = nat->nat_bytes[1]; 4664 natl.nl_pkts[0] = nat->nat_pkts[0]; 4665 natl.nl_pkts[1] = nat->nat_pkts[1]; 4666 natl.nl_origport = nat->nat_oport; 4667 natl.nl_inport = nat->nat_inport; 4668 natl.nl_outport = nat->nat_outport; 4669 natl.nl_p = nat->nat_p; 4670 natl.nl_type = type; 4671 natl.nl_rule = -1; 4672 # ifndef LARGE_NAT 4673 if (nat->nat_ptr != NULL) { 4674 for (rulen = 0, np = ifs->ifs_nat_list; np; 4675 np = np->in_next, rulen++) 4676 if (np == nat->nat_ptr) { 4677 natl.nl_rule = rulen; 4678 break; 4679 } 4680 } 4681 # endif 4682 items[0] = &natl; 4683 sizes[0] = sizeof(natl); 4684 types[0] = 0; 4685 4686 (void) ipllog(IPL_LOGNAT, NULL, items, sizes, types, 1, ifs); 4687 #endif 4688 } 4689 4690 4691 #if defined(__OpenBSD__) 4692 /* ------------------------------------------------------------------------ */ 4693 /* Function: nat_ifdetach */ 4694 /* Returns: Nil */ 4695 /* Parameters: ifp(I) - pointer to network interface */ 4696 /* */ 4697 /* Compatibility interface for OpenBSD to trigger the correct updating of */ 4698 /* interface references within IPFilter. */ 4699 /* ------------------------------------------------------------------------ */ 4700 void nat_ifdetach(ifp, ifs) 4701 void *ifp; 4702 ipf_stack_t *ifs; 4703 { 4704 frsync(ifp, ifs); 4705 return; 4706 } 4707 #endif 4708 4709 4710 /* ------------------------------------------------------------------------ */ 4711 /* Function: fr_ipnatderef */ 4712 /* Returns: Nil */ 4713 /* Parameters: isp(I) - pointer to pointer to NAT rule */ 4714 /* Write Locks: ipf_nat */ 4715 /* */ 4716 /* ------------------------------------------------------------------------ */ 4717 void fr_ipnatderef(inp, ifs) 4718 ipnat_t **inp; 4719 ipf_stack_t *ifs; 4720 { 4721 ipnat_t *in; 4722 4723 in = *inp; 4724 *inp = NULL; 4725 in->in_space++; 4726 in->in_use--; 4727 if (in->in_use == 0 && (in->in_flags & IPN_DELETE)) { 4728 if (in->in_apr) 4729 appr_free(in->in_apr); 4730 KFREE(in); 4731 ifs->ifs_nat_stats.ns_rules--; 4732 #ifdef notdef 4733 #if SOLARIS 4734 if (ifs->ifs_nat_stats.ns_rules == 0) 4735 ifs->ifs_pfil_delayed_copy = 1; 4736 #endif 4737 #endif 4738 } 4739 } 4740 4741 4742 /* ------------------------------------------------------------------------ */ 4743 /* Function: fr_natderef */ 4744 /* Returns: Nil */ 4745 /* Parameters: isp(I) - pointer to pointer to NAT table entry */ 4746 /* */ 4747 /* Decrement the reference counter for this NAT table entry and free it if */ 4748 /* there are no more things using it. */ 4749 /* ------------------------------------------------------------------------ */ 4750 void fr_natderef(natp, ifs) 4751 nat_t **natp; 4752 ipf_stack_t *ifs; 4753 { 4754 nat_t *nat; 4755 4756 nat = *natp; 4757 *natp = NULL; 4758 WRITE_ENTER(&ifs->ifs_ipf_nat); 4759 nat->nat_ref--; 4760 if (nat->nat_ref == 0) 4761 nat_delete(nat, NL_EXPIRE, ifs); 4762 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 4763 } 4764 4765 4766 /* ------------------------------------------------------------------------ */ 4767 /* Function: fr_natclone */ 4768 /* Returns: ipstate_t* - NULL == cloning failed, */ 4769 /* else pointer to new state structure */ 4770 /* Parameters: fin(I) - pointer to packet information */ 4771 /* is(I) - pointer to master state structure */ 4772 /* Write Lock: ipf_nat */ 4773 /* */ 4774 /* Create a "duplcate" state table entry from the master. */ 4775 /* ------------------------------------------------------------------------ */ 4776 static nat_t *fr_natclone(fin, nat) 4777 fr_info_t *fin; 4778 nat_t *nat; 4779 { 4780 frentry_t *fr; 4781 nat_t *clone; 4782 ipnat_t *np; 4783 ipf_stack_t *ifs = fin->fin_ifs; 4784 4785 KMALLOC(clone, nat_t *); 4786 if (clone == NULL) 4787 return NULL; 4788 bcopy((char *)nat, (char *)clone, sizeof(*clone)); 4789 4790 MUTEX_NUKE(&clone->nat_lock); 4791 4792 clone->nat_aps = NULL; 4793 /* 4794 * Initialize all these so that nat_delete() doesn't cause a crash. 4795 */ 4796 clone->nat_tqe.tqe_pnext = NULL; 4797 clone->nat_tqe.tqe_next = NULL; 4798 clone->nat_tqe.tqe_ifq = NULL; 4799 clone->nat_tqe.tqe_parent = clone; 4800 4801 clone->nat_flags &= ~SI_CLONE; 4802 clone->nat_flags |= SI_CLONED; 4803 4804 if (clone->nat_hm) 4805 clone->nat_hm->hm_ref++; 4806 4807 if (nat_insert(clone, fin->fin_rev, ifs) == -1) { 4808 KFREE(clone); 4809 return NULL; 4810 } 4811 np = clone->nat_ptr; 4812 if (np != NULL) { 4813 if (ifs->ifs_nat_logging) 4814 nat_log(clone, (u_int)np->in_redir, ifs); 4815 np->in_use++; 4816 } 4817 fr = clone->nat_fr; 4818 if (fr != NULL) { 4819 MUTEX_ENTER(&fr->fr_lock); 4820 fr->fr_ref++; 4821 MUTEX_EXIT(&fr->fr_lock); 4822 } 4823 4824 /* 4825 * Because the clone is created outside the normal loop of things and 4826 * TCP has special needs in terms of state, initialise the timeout 4827 * state of the new NAT from here. 4828 */ 4829 if (clone->nat_p == IPPROTO_TCP) { 4830 (void) fr_tcp_age(&clone->nat_tqe, fin, ifs->ifs_nat_tqb, 4831 clone->nat_flags); 4832 } 4833 #ifdef IPFILTER_SYNC 4834 clone->nat_sync = ipfsync_new(SMC_NAT, fin, clone); 4835 #endif 4836 if (ifs->ifs_nat_logging) 4837 nat_log(clone, NL_CLONE, ifs); 4838 return clone; 4839 } 4840 4841 4842 /* ------------------------------------------------------------------------ */ 4843 /* Function: nat_wildok */ 4844 /* Returns: int - 1 == packet's ports match wildcards */ 4845 /* 0 == packet's ports don't match wildcards */ 4846 /* Parameters: nat(I) - NAT entry */ 4847 /* sport(I) - source port */ 4848 /* dport(I) - destination port */ 4849 /* flags(I) - wildcard flags */ 4850 /* dir(I) - packet direction */ 4851 /* */ 4852 /* Use NAT entry and packet direction to determine which combination of */ 4853 /* wildcard flags should be used. */ 4854 /* ------------------------------------------------------------------------ */ 4855 static INLINE int nat_wildok(nat, sport, dport, flags, dir) 4856 nat_t *nat; 4857 int sport; 4858 int dport; 4859 int flags; 4860 int dir; 4861 { 4862 /* 4863 * When called by dir is set to 4864 * nat_inlookup NAT_INBOUND (0) 4865 * nat_outlookup NAT_OUTBOUND (1) 4866 * 4867 * We simply combine the packet's direction in dir with the original 4868 * "intended" direction of that NAT entry in nat->nat_dir to decide 4869 * which combination of wildcard flags to allow. 4870 */ 4871 4872 switch ((dir << 1) | nat->nat_dir) 4873 { 4874 case 3: /* outbound packet / outbound entry */ 4875 if (((nat->nat_inport == sport) || 4876 (flags & SI_W_SPORT)) && 4877 ((nat->nat_oport == dport) || 4878 (flags & SI_W_DPORT))) 4879 return 1; 4880 break; 4881 case 2: /* outbound packet / inbound entry */ 4882 if (((nat->nat_outport == sport) || 4883 (flags & SI_W_DPORT)) && 4884 ((nat->nat_oport == dport) || 4885 (flags & SI_W_SPORT))) 4886 return 1; 4887 break; 4888 case 1: /* inbound packet / outbound entry */ 4889 if (((nat->nat_oport == sport) || 4890 (flags & SI_W_DPORT)) && 4891 ((nat->nat_outport == dport) || 4892 (flags & SI_W_SPORT))) 4893 return 1; 4894 break; 4895 case 0: /* inbound packet / inbound entry */ 4896 if (((nat->nat_oport == sport) || 4897 (flags & SI_W_SPORT)) && 4898 ((nat->nat_outport == dport) || 4899 (flags & SI_W_DPORT))) 4900 return 1; 4901 break; 4902 default: 4903 break; 4904 } 4905 4906 return(0); 4907 } 4908 4909 4910 /* ------------------------------------------------------------------------ */ 4911 /* Function: nat_mssclamp */ 4912 /* Returns: Nil */ 4913 /* Parameters: tcp(I) - pointer to TCP header */ 4914 /* maxmss(I) - value to clamp the TCP MSS to */ 4915 /* csump(I) - pointer to TCP checksum */ 4916 /* */ 4917 /* Check for MSS option and clamp it if necessary. If found and changed, */ 4918 /* then the TCP header checksum will be updated to reflect the change in */ 4919 /* the MSS. */ 4920 /* ------------------------------------------------------------------------ */ 4921 static void nat_mssclamp(tcp, maxmss, csump) 4922 tcphdr_t *tcp; 4923 u_32_t maxmss; 4924 u_short *csump; 4925 { 4926 u_char *cp, *ep, opt; 4927 int hlen, advance; 4928 u_32_t mss, sumd; 4929 4930 hlen = TCP_OFF(tcp) << 2; 4931 if (hlen > sizeof(*tcp)) { 4932 cp = (u_char *)tcp + sizeof(*tcp); 4933 ep = (u_char *)tcp + hlen; 4934 4935 while (cp < ep) { 4936 opt = cp[0]; 4937 if (opt == TCPOPT_EOL) 4938 break; 4939 else if (opt == TCPOPT_NOP) { 4940 cp++; 4941 continue; 4942 } 4943 4944 if (cp + 1 >= ep) 4945 break; 4946 advance = cp[1]; 4947 if ((cp + advance > ep) || (advance <= 0)) 4948 break; 4949 switch (opt) 4950 { 4951 case TCPOPT_MAXSEG: 4952 if (advance != 4) 4953 break; 4954 mss = cp[2] * 256 + cp[3]; 4955 if (mss > maxmss) { 4956 cp[2] = maxmss / 256; 4957 cp[3] = maxmss & 0xff; 4958 CALC_SUMD(mss, maxmss, sumd); 4959 fix_outcksum(csump, sumd); 4960 } 4961 break; 4962 default: 4963 /* ignore unknown options */ 4964 break; 4965 } 4966 4967 cp += advance; 4968 } 4969 } 4970 } 4971 4972 4973 /* ------------------------------------------------------------------------ */ 4974 /* Function: fr_setnatqueue */ 4975 /* Returns: Nil */ 4976 /* Parameters: nat(I)- pointer to NAT structure */ 4977 /* rev(I) - forward(0) or reverse(1) direction */ 4978 /* Locks: ipf_nat (read or write) */ 4979 /* */ 4980 /* Put the NAT entry on its default queue entry, using rev as a helped in */ 4981 /* determining which queue it should be placed on. */ 4982 /* ------------------------------------------------------------------------ */ 4983 void fr_setnatqueue(nat, rev, ifs) 4984 nat_t *nat; 4985 int rev; 4986 ipf_stack_t *ifs; 4987 { 4988 ipftq_t *oifq, *nifq; 4989 4990 if (nat->nat_ptr != NULL) 4991 nifq = nat->nat_ptr->in_tqehead[rev]; 4992 else 4993 nifq = NULL; 4994 4995 if (nifq == NULL) { 4996 switch (nat->nat_p) 4997 { 4998 case IPPROTO_UDP : 4999 nifq = &ifs->ifs_nat_udptq; 5000 break; 5001 case IPPROTO_ICMP : 5002 nifq = &ifs->ifs_nat_icmptq; 5003 break; 5004 case IPPROTO_TCP : 5005 nifq = ifs->ifs_nat_tqb + nat->nat_tqe.tqe_state[rev]; 5006 break; 5007 default : 5008 nifq = &ifs->ifs_nat_iptq; 5009 break; 5010 } 5011 } 5012 5013 oifq = nat->nat_tqe.tqe_ifq; 5014 /* 5015 * If it's currently on a timeout queue, move it from one queue to 5016 * another, else put it on the end of the newly determined queue. 5017 */ 5018 if (oifq != NULL) 5019 fr_movequeue(&nat->nat_tqe, oifq, nifq, ifs); 5020 else 5021 fr_queueappend(&nat->nat_tqe, nifq, nat, ifs); 5022 return; 5023 } 5024 5025 /* Function: nat_getnext */ 5026 /* Returns: int - 0 == ok, else error */ 5027 /* Parameters: t(I) - pointer to ipftoken structure */ 5028 /* itp(I) - pointer to ipfgeniter_t structure */ 5029 /* */ 5030 /* Fetch the next nat/ipnat structure pointer from the linked list and */ 5031 /* copy it out to the storage space pointed to by itp_data. The next item */ 5032 /* in the list to look at is put back in the ipftoken struture. */ 5033 /* If we call ipf_freetoken, the accompanying pointer is set to NULL because*/ 5034 /* ipf_freetoken will call a deref function for us and we dont want to call */ 5035 /* that twice (second time would be in the second switch statement below. */ 5036 /* ------------------------------------------------------------------------ */ 5037 static int nat_getnext(t, itp, ifs) 5038 ipftoken_t *t; 5039 ipfgeniter_t *itp; 5040 ipf_stack_t *ifs; 5041 { 5042 hostmap_t *hm, *nexthm = NULL, zerohm; 5043 ipnat_t *ipn, *nextipnat = NULL, zeroipn; 5044 nat_t *nat, *nextnat = NULL, zeronat; 5045 int error = 0; 5046 5047 READ_ENTER(&ifs->ifs_ipf_nat); 5048 switch (itp->igi_type) 5049 { 5050 case IPFGENITER_HOSTMAP : 5051 hm = t->ipt_data; 5052 if (hm == NULL) { 5053 nexthm = ifs->ifs_ipf_hm_maplist; 5054 } else { 5055 nexthm = hm->hm_hnext; 5056 } 5057 if (nexthm != NULL) { 5058 if (nexthm->hm_hnext == NULL) { 5059 t->ipt_alive = 0; 5060 ipf_unlinktoken(t, ifs); 5061 KFREE(t); 5062 } else { 5063 /*MUTEX_ENTER(&nexthm->hm_lock);*/ 5064 nexthm->hm_ref++; 5065 /*MUTEX_EXIT(&nextipnat->hm_lock);*/ 5066 } 5067 5068 } else { 5069 bzero(&zerohm, sizeof(zerohm)); 5070 nexthm = &zerohm; 5071 ipf_freetoken(t, ifs); 5072 } 5073 break; 5074 5075 case IPFGENITER_IPNAT : 5076 ipn = t->ipt_data; 5077 if (ipn == NULL) { 5078 nextipnat = ifs->ifs_nat_list; 5079 } else { 5080 nextipnat = ipn->in_next; 5081 } 5082 if (nextipnat != NULL) { 5083 if (nextipnat->in_next == NULL) { 5084 t->ipt_alive = 0; 5085 ipf_unlinktoken(t, ifs); 5086 KFREE(t); 5087 } else { 5088 /* MUTEX_ENTER(&nextipnat->in_lock); */ 5089 nextipnat->in_use++; 5090 /* MUTEX_EXIT(&nextipnat->in_lock); */ 5091 } 5092 } else { 5093 bzero(&zeroipn, sizeof(zeroipn)); 5094 nextipnat = &zeroipn; 5095 ipf_freetoken(t, ifs); 5096 } 5097 break; 5098 5099 case IPFGENITER_NAT : 5100 nat = t->ipt_data; 5101 if (nat == NULL) { 5102 nextnat = ifs->ifs_nat_instances; 5103 } else { 5104 nextnat = nat->nat_next; 5105 } 5106 if (nextnat != NULL) { 5107 if (nextnat->nat_next == NULL) { 5108 t->ipt_alive = 0; 5109 ipf_unlinktoken(t, ifs); 5110 KFREE(t); 5111 } else { 5112 MUTEX_ENTER(&nextnat->nat_lock); 5113 nextnat->nat_ref++; 5114 MUTEX_EXIT(&nextnat->nat_lock); 5115 } 5116 } else { 5117 bzero(&zeronat, sizeof(zeronat)); 5118 nextnat = &zeronat; 5119 ipf_freetoken(t, ifs); 5120 } 5121 break; 5122 } 5123 5124 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 5125 5126 switch (itp->igi_type) 5127 { 5128 case IPFGENITER_HOSTMAP : 5129 if (hm != NULL) { 5130 WRITE_ENTER(&ifs->ifs_ipf_nat); 5131 fr_hostmapderef(&hm); 5132 RWLOCK_EXIT(&ifs->ifs_ipf_nat); 5133 } 5134 if (nexthm->hm_hnext != NULL) 5135 t->ipt_data = nexthm; 5136 error = COPYOUT(nexthm, itp->igi_data, sizeof(*nexthm)); 5137 if (error != 0) 5138 error = EFAULT; 5139 break; 5140 5141 case IPFGENITER_IPNAT : 5142 if (ipn != NULL) 5143 fr_ipnatderef(&ipn, ifs); 5144 if (nextipnat->in_next != NULL) 5145 t->ipt_data = nextipnat; 5146 error = COPYOUT(nextipnat, itp->igi_data, sizeof(*nextipnat)); 5147 if (error != 0) 5148 error = EFAULT; 5149 break; 5150 5151 case IPFGENITER_NAT : 5152 if (nat != NULL) 5153 fr_natderef(&nat, ifs); 5154 if (nextnat->nat_next != NULL) 5155 t->ipt_data = nextnat; 5156 error = COPYOUT(nextnat, itp->igi_data, sizeof(*nextnat)); 5157 if (error != 0) 5158 error = EFAULT; 5159 break; 5160 } 5161 5162 return error; 5163 } 5164 5165 5166 /* ------------------------------------------------------------------------ */ 5167 /* Function: nat_iterator */ 5168 /* Returns: int - 0 == ok, else error */ 5169 /* Parameters: token(I) - pointer to ipftoken structure */ 5170 /* itp(I) - pointer to ipfgeniter_t structure */ 5171 /* */ 5172 /* This function acts as a handler for the SIOCGENITER ioctls that use a */ 5173 /* generic structure to iterate through a list. There are three different */ 5174 /* linked lists of NAT related information to go through: NAT rules, active */ 5175 /* NAT mappings and the NAT fragment cache. */ 5176 /* ------------------------------------------------------------------------ */ 5177 static int nat_iterator(token, itp, ifs) 5178 ipftoken_t *token; 5179 ipfgeniter_t *itp; 5180 ipf_stack_t *ifs; 5181 { 5182 int error; 5183 5184 if (itp->igi_data == NULL) 5185 return EFAULT; 5186 5187 token->ipt_subtype = itp->igi_type; 5188 5189 switch (itp->igi_type) 5190 { 5191 case IPFGENITER_HOSTMAP : 5192 case IPFGENITER_IPNAT : 5193 case IPFGENITER_NAT : 5194 error = nat_getnext(token, itp, ifs); 5195 break; 5196 case IPFGENITER_NATFRAG : 5197 error = fr_nextfrag(token, itp, &ifs->ifs_ipfr_natlist, 5198 &ifs->ifs_ipfr_nattail, 5199 &ifs->ifs_ipf_natfrag, ifs); 5200 break; 5201 default : 5202 error = EINVAL; 5203 break; 5204 } 5205 5206 return error; 5207 } 5208 5209 5210 /* -------------------------------------------------------------------- */ 5211 /* Function: nat_earlydrop */ 5212 /* Returns: number of dropped/removed entries from the queue */ 5213 /* Parameters: ifq - pointer to queue with entries to be processed */ 5214 /* maxidle - entry must be idle this long to be dropped */ 5215 /* ifs - ipf stack instance */ 5216 /* */ 5217 /* Function is invoked from nat_extraflush() only. Removes entries */ 5218 /* form specified timeout queue, based on how long they've sat idle, */ 5219 /* without waiting for it to happen on its own. */ 5220 /* -------------------------------------------------------------------- */ 5221 static int nat_earlydrop(ifq, maxidle, ifs) 5222 ipftq_t *ifq; 5223 int maxidle; 5224 ipf_stack_t *ifs; 5225 { 5226 ipftqent_t *tqe, *tqn; 5227 nat_t *nat; 5228 unsigned int dropped; 5229 int droptick; 5230 5231 if (ifq == NULL) 5232 return (0); 5233 5234 dropped = 0; 5235 5236 /* 5237 * Determine the tick representing the idle time we're interested 5238 * in. If an entry exists in the queue, and it was touched before 5239 * that tick, then it's been idle longer than maxidle ... remove it. 5240 */ 5241 droptick = ifs->ifs_fr_ticks - maxidle; 5242 tqn = ifq->ifq_head; 5243 while ((tqe = tqn) != NULL && tqe->tqe_touched < droptick) { 5244 tqn = tqe->tqe_next; 5245 nat = tqe->tqe_parent; 5246 nat_delete(nat, ISL_EXPIRE, ifs); 5247 dropped++; 5248 } 5249 return (dropped); 5250 } 5251 5252 5253 /* --------------------------------------------------------------------- */ 5254 /* Function: nat_flushclosing */ 5255 /* Returns: int - number of NAT entries deleted */ 5256 /* Parameters: stateval(I) - State at which to start removing entries */ 5257 /* ifs - ipf stack instance */ 5258 /* */ 5259 /* Remove nat table entries for TCP connections which are in the process */ 5260 /* of closing, and are in (or "beyond") state specified by 'stateval'. */ 5261 /* --------------------------------------------------------------------- */ 5262 static int nat_flushclosing(stateval, ifs) 5263 int stateval; 5264 ipf_stack_t *ifs; 5265 { 5266 ipftq_t *ifq, *ifqn; 5267 ipftqent_t *tqe, *tqn; 5268 nat_t *nat; 5269 int dropped; 5270 5271 dropped = 0; 5272 5273 /* 5274 * Start by deleting any entries in specific timeout queues. 5275 */ 5276 ifqn = &ifs->ifs_nat_tqb[stateval]; 5277 while ((ifq = ifqn) != NULL) { 5278 ifqn = ifq->ifq_next; 5279 dropped += nat_earlydrop(ifq, (int)0, ifs); 5280 } 5281 5282 /* 5283 * Next, look through user defined queues for closing entries. 5284 */ 5285 ifqn = ifs->ifs_nat_utqe; 5286 while ((ifq = ifqn) != NULL) { 5287 ifqn = ifq->ifq_next; 5288 tqn = ifq->ifq_head; 5289 while ((tqe = tqn) != NULL) { 5290 tqn = tqe->tqe_next; 5291 nat = tqe->tqe_parent; 5292 if (nat->nat_p != IPPROTO_TCP) 5293 continue; 5294 if ((nat->nat_tcpstate[0] >= stateval) && 5295 (nat->nat_tcpstate[1] >= stateval)) { 5296 nat_delete(nat, NL_EXPIRE, ifs); 5297 dropped++; 5298 } 5299 } 5300 } 5301 return (dropped); 5302 } 5303 5304 5305 /* --------------------------------------------------------------------- */ 5306 /* Function: nat_extraflush */ 5307 /* Returns: int - number of NAT entries deleted */ 5308 /* Parameters: which(I) - how to flush the active NAT table */ 5309 /* ifs - ipf stack instance */ 5310 /* Write Locks: ipf_nat */ 5311 /* */ 5312 /* Flush nat tables. Three actions currently defined: */ 5313 /* */ 5314 /* which == 0 : Flush all nat table entries. */ 5315 /* */ 5316 /* which == 1 : Flush entries with TCP connections which have started */ 5317 /* to close on both ends. */ 5318 /* */ 5319 /* which == 2 : First, flush entries which are "almost" closed. If that */ 5320 /* does not take us below specified threshold in the table, */ 5321 /* we want to flush entries with TCP connections which have */ 5322 /* been idle for a long time. Start with connections idle */ 5323 /* over 12 hours, and then work backwards in half hour */ 5324 /* increments to at most 30 minutes idle, and finally work */ 5325 /* back in 30 second increments to at most 30 seconds. */ 5326 /* --------------------------------------------------------------------- */ 5327 static int nat_extraflush(which, ifs) 5328 int which; 5329 ipf_stack_t *ifs; 5330 { 5331 ipftq_t *ifq, *ifqn; 5332 nat_t *nat, **natp; 5333 int idletime, removed, idle_idx; 5334 SPL_INT(s); 5335 5336 removed = 0; 5337 5338 SPL_NET(s); 5339 switch (which) 5340 { 5341 case 0: 5342 natp = &ifs->ifs_nat_instances; 5343 while ((nat = *natp) != NULL) { 5344 natp = &nat->nat_next; 5345 nat_delete(nat, ISL_FLUSH, ifs); 5346 removed++; 5347 } 5348 break; 5349 5350 case 1: 5351 removed = nat_flushclosing(IPF_TCPS_CLOSE_WAIT, ifs); 5352 break; 5353 5354 case 2: 5355 removed = nat_flushclosing(IPF_TCPS_FIN_WAIT_2, ifs); 5356 5357 /* 5358 * Be sure we haven't done this in the last 10 seconds. 5359 */ 5360 if (ifs->ifs_fr_ticks - ifs->ifs_nat_last_force_flush < 5361 IPF_TTLVAL(10)) 5362 break; 5363 ifs->ifs_nat_last_force_flush = ifs->ifs_fr_ticks; 5364 5365 /* 5366 * Determine initial threshold for minimum idle time based on 5367 * how long ipfilter has been running. Ipfilter needs to have 5368 * been up as long as the smallest interval to continue on. 5369 * 5370 * Minimum idle times stored in idletime_tab and indexed by 5371 * idle_idx. Start at upper end of array and work backwards. 5372 * 5373 * Once the index is found, set the initial idle time to the 5374 * first interval before the current ipfilter run time. 5375 */ 5376 if (ifs->ifs_fr_ticks < idletime_tab[0]) 5377 break; /* switch */ 5378 idle_idx = (sizeof (idletime_tab) / sizeof (int)) - 1; 5379 if (ifs->ifs_fr_ticks > idletime_tab[idle_idx]) { 5380 idletime = idletime_tab[idle_idx]; 5381 } else { 5382 while ((idle_idx > 0) && 5383 (ifs->ifs_fr_ticks < idletime_tab[idle_idx])) 5384 idle_idx--; 5385 idletime = (ifs->ifs_fr_ticks / 5386 idletime_tab[idle_idx]) * 5387 idletime_tab[idle_idx]; 5388 } 5389 5390 while ((idle_idx >= 0) && 5391 (NAT_TAB_WATER_LEVEL(ifs) > ifs->ifs_nat_flush_lvl_lo)) { 5392 /* 5393 * Start with appropriate timeout queue. 5394 */ 5395 removed += nat_earlydrop( 5396 &ifs->ifs_nat_tqb[IPF_TCPS_ESTABLISHED], 5397 idletime, ifs); 5398 5399 /* 5400 * Make sure we haven't already deleted enough 5401 * entries before checking the user defined queues. 5402 */ 5403 if (NAT_TAB_WATER_LEVEL(ifs) <= 5404 ifs->ifs_nat_flush_lvl_lo) 5405 break; 5406 5407 /* 5408 * Next, look through the user defined queues. 5409 */ 5410 ifqn = ifs->ifs_nat_utqe; 5411 while ((ifq = ifqn) != NULL) { 5412 ifqn = ifq->ifq_next; 5413 removed += nat_earlydrop(ifq, idletime, ifs); 5414 } 5415 5416 /* 5417 * Adjust the granularity of idle time. 5418 * 5419 * If we reach an interval boundary, we need to 5420 * either adjust the idle time accordingly or exit 5421 * the loop altogether (if this is very last check). 5422 */ 5423 idletime -= idletime_tab[idle_idx]; 5424 if (idletime < idletime_tab[idle_idx]) { 5425 if (idle_idx != 0) { 5426 idletime = idletime_tab[idle_idx] - 5427 idletime_tab[idle_idx - 1]; 5428 idle_idx--; 5429 } else { 5430 break; /* while */ 5431 } 5432 } 5433 } 5434 break; 5435 default: 5436 break; 5437 } 5438 5439 SPL_X(s); 5440 return (removed); 5441 } 5442