1 /* SCTP kernel implementation 2 * (C) Copyright IBM Corp. 2001, 2003 3 * Copyright (c) Cisco 1999,2000 4 * Copyright (c) Motorola 1999,2000,2001 5 * Copyright (c) La Monte H.P. Yarroll 2001 6 * 7 * This file is part of the SCTP kernel implementation. 8 * 9 * A collection class to handle the storage of transport addresses. 10 * 11 * This SCTP implementation is free software; 12 * you can redistribute it and/or modify it under the terms of 13 * the GNU General Public License as published by 14 * the Free Software Foundation; either version 2, or (at your option) 15 * any later version. 16 * 17 * This SCTP implementation is distributed in the hope that it 18 * will be useful, but WITHOUT ANY WARRANTY; without even the implied 19 * ************************ 20 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 21 * See the GNU General Public License for more details. 22 * 23 * You should have received a copy of the GNU General Public License 24 * along with GNU CC; see the file COPYING. If not, write to 25 * the Free Software Foundation, 59 Temple Place - Suite 330, 26 * Boston, MA 02111-1307, USA. 27 * 28 * Please send any bug reports or fixes you make to the 29 * email address(es): 30 * lksctp developers <lksctp-developers@lists.sourceforge.net> 31 * 32 * Or submit a bug report through the following website: 33 * http://www.sf.net/projects/lksctp 34 * 35 * Written or modified by: 36 * La Monte H.P. Yarroll <piggy@acm.org> 37 * Karl Knutson <karl@athena.chicago.il.us> 38 * Jon Grimm <jgrimm@us.ibm.com> 39 * Daisy Chang <daisyc@us.ibm.com> 40 * 41 * Any bugs reported given to us we will try to fix... any fixes shared will 42 * be incorporated into the next SCTP release. 43 */ 44 45 #include <linux/types.h> 46 #include <linux/slab.h> 47 #include <linux/in.h> 48 #include <net/sock.h> 49 #include <net/ipv6.h> 50 #include <net/if_inet6.h> 51 #include <net/sctp/sctp.h> 52 #include <net/sctp/sm.h> 53 54 /* Forward declarations for internal helpers. */ 55 static int sctp_copy_one_addr(struct sctp_bind_addr *, union sctp_addr *, 56 sctp_scope_t scope, gfp_t gfp, 57 int flags); 58 static void sctp_bind_addr_clean(struct sctp_bind_addr *); 59 60 /* First Level Abstractions. */ 61 62 /* Copy 'src' to 'dest' taking 'scope' into account. Omit addresses 63 * in 'src' which have a broader scope than 'scope'. 64 */ 65 int sctp_bind_addr_copy(struct sctp_bind_addr *dest, 66 const struct sctp_bind_addr *src, 67 sctp_scope_t scope, gfp_t gfp, 68 int flags) 69 { 70 struct sctp_sockaddr_entry *addr; 71 int error = 0; 72 73 /* All addresses share the same port. */ 74 dest->port = src->port; 75 76 /* Extract the addresses which are relevant for this scope. */ 77 list_for_each_entry(addr, &src->address_list, list) { 78 error = sctp_copy_one_addr(dest, &addr->a, scope, 79 gfp, flags); 80 if (error < 0) 81 goto out; 82 } 83 84 /* If there are no addresses matching the scope and 85 * this is global scope, try to get a link scope address, with 86 * the assumption that we must be sitting behind a NAT. 87 */ 88 if (list_empty(&dest->address_list) && (SCTP_SCOPE_GLOBAL == scope)) { 89 list_for_each_entry(addr, &src->address_list, list) { 90 error = sctp_copy_one_addr(dest, &addr->a, 91 SCTP_SCOPE_LINK, gfp, 92 flags); 93 if (error < 0) 94 goto out; 95 } 96 } 97 98 out: 99 if (error) 100 sctp_bind_addr_clean(dest); 101 102 return error; 103 } 104 105 /* Exactly duplicate the address lists. This is necessary when doing 106 * peer-offs and accepts. We don't want to put all the current system 107 * addresses into the endpoint. That's useless. But we do want duplicat 108 * the list of bound addresses that the older endpoint used. 109 */ 110 int sctp_bind_addr_dup(struct sctp_bind_addr *dest, 111 const struct sctp_bind_addr *src, 112 gfp_t gfp) 113 { 114 struct sctp_sockaddr_entry *addr; 115 int error = 0; 116 117 /* All addresses share the same port. */ 118 dest->port = src->port; 119 120 list_for_each_entry(addr, &src->address_list, list) { 121 error = sctp_add_bind_addr(dest, &addr->a, 1, gfp); 122 if (error < 0) 123 break; 124 } 125 126 return error; 127 } 128 129 /* Initialize the SCTP_bind_addr structure for either an endpoint or 130 * an association. 131 */ 132 void sctp_bind_addr_init(struct sctp_bind_addr *bp, __u16 port) 133 { 134 bp->malloced = 0; 135 136 INIT_LIST_HEAD(&bp->address_list); 137 bp->port = port; 138 } 139 140 /* Dispose of the address list. */ 141 static void sctp_bind_addr_clean(struct sctp_bind_addr *bp) 142 { 143 struct sctp_sockaddr_entry *addr, *temp; 144 145 /* Empty the bind address list. */ 146 list_for_each_entry_safe(addr, temp, &bp->address_list, list) { 147 list_del_rcu(&addr->list); 148 kfree_rcu(addr, rcu); 149 SCTP_DBG_OBJCNT_DEC(addr); 150 } 151 } 152 153 /* Dispose of an SCTP_bind_addr structure */ 154 void sctp_bind_addr_free(struct sctp_bind_addr *bp) 155 { 156 /* Empty the bind address list. */ 157 sctp_bind_addr_clean(bp); 158 159 if (bp->malloced) { 160 kfree(bp); 161 SCTP_DBG_OBJCNT_DEC(bind_addr); 162 } 163 } 164 165 /* Add an address to the bind address list in the SCTP_bind_addr structure. */ 166 int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new, 167 __u8 addr_state, gfp_t gfp) 168 { 169 struct sctp_sockaddr_entry *addr; 170 171 /* Add the address to the bind address list. */ 172 addr = t_new(struct sctp_sockaddr_entry, gfp); 173 if (!addr) 174 return -ENOMEM; 175 176 memcpy(&addr->a, new, sizeof(*new)); 177 178 /* Fix up the port if it has not yet been set. 179 * Both v4 and v6 have the port at the same offset. 180 */ 181 if (!addr->a.v4.sin_port) 182 addr->a.v4.sin_port = htons(bp->port); 183 184 addr->state = addr_state; 185 addr->valid = 1; 186 187 INIT_LIST_HEAD(&addr->list); 188 189 /* We always hold a socket lock when calling this function, 190 * and that acts as a writer synchronizing lock. 191 */ 192 list_add_tail_rcu(&addr->list, &bp->address_list); 193 SCTP_DBG_OBJCNT_INC(addr); 194 195 return 0; 196 } 197 198 /* Delete an address from the bind address list in the SCTP_bind_addr 199 * structure. 200 */ 201 int sctp_del_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *del_addr) 202 { 203 struct sctp_sockaddr_entry *addr, *temp; 204 int found = 0; 205 206 /* We hold the socket lock when calling this function, 207 * and that acts as a writer synchronizing lock. 208 */ 209 list_for_each_entry_safe(addr, temp, &bp->address_list, list) { 210 if (sctp_cmp_addr_exact(&addr->a, del_addr)) { 211 /* Found the exact match. */ 212 found = 1; 213 addr->valid = 0; 214 list_del_rcu(&addr->list); 215 break; 216 } 217 } 218 219 if (found) { 220 kfree_rcu(addr, rcu); 221 SCTP_DBG_OBJCNT_DEC(addr); 222 return 0; 223 } 224 225 return -EINVAL; 226 } 227 228 /* Create a network byte-order representation of all the addresses 229 * formated as SCTP parameters. 230 * 231 * The second argument is the return value for the length. 232 */ 233 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, 234 int *addrs_len, 235 gfp_t gfp) 236 { 237 union sctp_params addrparms; 238 union sctp_params retval; 239 int addrparms_len; 240 union sctp_addr_param rawaddr; 241 int len; 242 struct sctp_sockaddr_entry *addr; 243 struct list_head *pos; 244 struct sctp_af *af; 245 246 addrparms_len = 0; 247 len = 0; 248 249 /* Allocate enough memory at once. */ 250 list_for_each(pos, &bp->address_list) { 251 len += sizeof(union sctp_addr_param); 252 } 253 254 /* Don't even bother embedding an address if there 255 * is only one. 256 */ 257 if (len == sizeof(union sctp_addr_param)) { 258 retval.v = NULL; 259 goto end_raw; 260 } 261 262 retval.v = kmalloc(len, gfp); 263 if (!retval.v) 264 goto end_raw; 265 266 addrparms = retval; 267 268 list_for_each_entry(addr, &bp->address_list, list) { 269 af = sctp_get_af_specific(addr->a.v4.sin_family); 270 len = af->to_addr_param(&addr->a, &rawaddr); 271 memcpy(addrparms.v, &rawaddr, len); 272 addrparms.v += len; 273 addrparms_len += len; 274 } 275 276 end_raw: 277 *addrs_len = addrparms_len; 278 return retval; 279 } 280 281 /* 282 * Create an address list out of the raw address list format (IPv4 and IPv6 283 * address parameters). 284 */ 285 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list, 286 int addrs_len, __u16 port, gfp_t gfp) 287 { 288 union sctp_addr_param *rawaddr; 289 struct sctp_paramhdr *param; 290 union sctp_addr addr; 291 int retval = 0; 292 int len; 293 struct sctp_af *af; 294 295 /* Convert the raw address to standard address format */ 296 while (addrs_len) { 297 param = (struct sctp_paramhdr *)raw_addr_list; 298 rawaddr = (union sctp_addr_param *)raw_addr_list; 299 300 af = sctp_get_af_specific(param_type2af(param->type)); 301 if (unlikely(!af)) { 302 retval = -EINVAL; 303 sctp_bind_addr_clean(bp); 304 break; 305 } 306 307 af->from_addr_param(&addr, rawaddr, htons(port), 0); 308 retval = sctp_add_bind_addr(bp, &addr, SCTP_ADDR_SRC, gfp); 309 if (retval) { 310 /* Can't finish building the list, clean up. */ 311 sctp_bind_addr_clean(bp); 312 break; 313 } 314 315 len = ntohs(param->length); 316 addrs_len -= len; 317 raw_addr_list += len; 318 } 319 320 return retval; 321 } 322 323 /******************************************************************** 324 * 2nd Level Abstractions 325 ********************************************************************/ 326 327 /* Does this contain a specified address? Allow wildcarding. */ 328 int sctp_bind_addr_match(struct sctp_bind_addr *bp, 329 const union sctp_addr *addr, 330 struct sctp_sock *opt) 331 { 332 struct sctp_sockaddr_entry *laddr; 333 int match = 0; 334 335 rcu_read_lock(); 336 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 337 if (!laddr->valid) 338 continue; 339 if (opt->pf->cmp_addr(&laddr->a, addr, opt)) { 340 match = 1; 341 break; 342 } 343 } 344 rcu_read_unlock(); 345 346 return match; 347 } 348 349 /* Does the address 'addr' conflict with any addresses in 350 * the bp. 351 */ 352 int sctp_bind_addr_conflict(struct sctp_bind_addr *bp, 353 const union sctp_addr *addr, 354 struct sctp_sock *bp_sp, 355 struct sctp_sock *addr_sp) 356 { 357 struct sctp_sockaddr_entry *laddr; 358 int conflict = 0; 359 struct sctp_sock *sp; 360 361 /* Pick the IPv6 socket as the basis of comparison 362 * since it's usually a superset of the IPv4. 363 * If there is no IPv6 socket, then default to bind_addr. 364 */ 365 if (sctp_opt2sk(bp_sp)->sk_family == AF_INET6) 366 sp = bp_sp; 367 else if (sctp_opt2sk(addr_sp)->sk_family == AF_INET6) 368 sp = addr_sp; 369 else 370 sp = bp_sp; 371 372 rcu_read_lock(); 373 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 374 if (!laddr->valid) 375 continue; 376 377 conflict = sp->pf->cmp_addr(&laddr->a, addr, sp); 378 if (conflict) 379 break; 380 } 381 rcu_read_unlock(); 382 383 return conflict; 384 } 385 386 /* Get the state of the entry in the bind_addr_list */ 387 int sctp_bind_addr_state(const struct sctp_bind_addr *bp, 388 const union sctp_addr *addr) 389 { 390 struct sctp_sockaddr_entry *laddr; 391 struct sctp_af *af; 392 int state = -1; 393 394 af = sctp_get_af_specific(addr->sa.sa_family); 395 if (unlikely(!af)) 396 return state; 397 398 rcu_read_lock(); 399 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 400 if (!laddr->valid) 401 continue; 402 if (af->cmp_addr(&laddr->a, addr)) { 403 state = laddr->state; 404 break; 405 } 406 } 407 rcu_read_unlock(); 408 409 return state; 410 } 411 412 /* Find the first address in the bind address list that is not present in 413 * the addrs packed array. 414 */ 415 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, 416 const union sctp_addr *addrs, 417 int addrcnt, 418 struct sctp_sock *opt) 419 { 420 struct sctp_sockaddr_entry *laddr; 421 union sctp_addr *addr; 422 void *addr_buf; 423 struct sctp_af *af; 424 int i; 425 426 /* This is only called sctp_send_asconf_del_ip() and we hold 427 * the socket lock in that code patch, so that address list 428 * can't change. 429 */ 430 list_for_each_entry(laddr, &bp->address_list, list) { 431 addr_buf = (union sctp_addr *)addrs; 432 for (i = 0; i < addrcnt; i++) { 433 addr = (union sctp_addr *)addr_buf; 434 af = sctp_get_af_specific(addr->v4.sin_family); 435 if (!af) 436 break; 437 438 if (opt->pf->cmp_addr(&laddr->a, addr, opt)) 439 break; 440 441 addr_buf += af->sockaddr_len; 442 } 443 if (i == addrcnt) 444 return &laddr->a; 445 } 446 447 return NULL; 448 } 449 450 /* Copy out addresses from the global local address list. */ 451 static int sctp_copy_one_addr(struct sctp_bind_addr *dest, 452 union sctp_addr *addr, 453 sctp_scope_t scope, gfp_t gfp, 454 int flags) 455 { 456 int error = 0; 457 458 if (sctp_is_any(NULL, addr)) { 459 error = sctp_copy_local_addr_list(dest, scope, gfp, flags); 460 } else if (sctp_in_scope(addr, scope)) { 461 /* Now that the address is in scope, check to see if 462 * the address type is supported by local sock as 463 * well as the remote peer. 464 */ 465 if ((((AF_INET == addr->sa.sa_family) && 466 (flags & SCTP_ADDR4_PEERSUPP))) || 467 (((AF_INET6 == addr->sa.sa_family) && 468 (flags & SCTP_ADDR6_ALLOWED) && 469 (flags & SCTP_ADDR6_PEERSUPP)))) 470 error = sctp_add_bind_addr(dest, addr, SCTP_ADDR_SRC, 471 gfp); 472 } 473 474 return error; 475 } 476 477 /* Is this a wildcard address? */ 478 int sctp_is_any(struct sock *sk, const union sctp_addr *addr) 479 { 480 unsigned short fam = 0; 481 struct sctp_af *af; 482 483 /* Try to get the right address family */ 484 if (addr->sa.sa_family != AF_UNSPEC) 485 fam = addr->sa.sa_family; 486 else if (sk) 487 fam = sk->sk_family; 488 489 af = sctp_get_af_specific(fam); 490 if (!af) 491 return 0; 492 493 return af->is_any(addr); 494 } 495 496 /* Is 'addr' valid for 'scope'? */ 497 int sctp_in_scope(const union sctp_addr *addr, sctp_scope_t scope) 498 { 499 sctp_scope_t addr_scope = sctp_scope(addr); 500 501 /* The unusable SCTP addresses will not be considered with 502 * any defined scopes. 503 */ 504 if (SCTP_SCOPE_UNUSABLE == addr_scope) 505 return 0; 506 /* 507 * For INIT and INIT-ACK address list, let L be the level of 508 * of requested destination address, sender and receiver 509 * SHOULD include all of its addresses with level greater 510 * than or equal to L. 511 * 512 * Address scoping can be selectively controlled via sysctl 513 * option 514 */ 515 switch (sctp_scope_policy) { 516 case SCTP_SCOPE_POLICY_DISABLE: 517 return 1; 518 case SCTP_SCOPE_POLICY_ENABLE: 519 if (addr_scope <= scope) 520 return 1; 521 break; 522 case SCTP_SCOPE_POLICY_PRIVATE: 523 if (addr_scope <= scope || SCTP_SCOPE_PRIVATE == addr_scope) 524 return 1; 525 break; 526 case SCTP_SCOPE_POLICY_LINK: 527 if (addr_scope <= scope || SCTP_SCOPE_LINK == addr_scope) 528 return 1; 529 break; 530 default: 531 break; 532 } 533 534 return 0; 535 } 536 537 /******************************************************************** 538 * 3rd Level Abstractions 539 ********************************************************************/ 540 541 /* What is the scope of 'addr'? */ 542 sctp_scope_t sctp_scope(const union sctp_addr *addr) 543 { 544 struct sctp_af *af; 545 546 af = sctp_get_af_specific(addr->sa.sa_family); 547 if (!af) 548 return SCTP_SCOPE_UNUSABLE; 549 550 return af->scope((union sctp_addr *)addr); 551 } 552