net/sctp/bind_addr.c

   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;
 144         struct list_head *pos, *temp;
 145
 146         /* Empty the bind address list. */
 147         list_for_each_safe(pos, temp, &bp->address_list) {
 148                 addr = list_entry(pos, struct sctp_sockaddr_entry, list);
 149                 list_del(pos);
 150                 kfree(addr);
 151                 SCTP_DBG_OBJCNT_DEC(addr);
 152         }
 153 }
 154
 155 /* Dispose of an SCTP_bind_addr structure  */
 156 void sctp_bind_addr_free(struct sctp_bind_addr *bp)
 157 {
 158         /* Empty the bind address list. */
 159         sctp_bind_addr_clean(bp);
 160
 161         if (bp->malloced) {
 162                 kfree(bp);
 163                 SCTP_DBG_OBJCNT_DEC(bind_addr);
 164         }
 165 }
 166
 167 /* Add an address to the bind address list in the SCTP_bind_addr structure. */
 168 int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new,
 169                        __u8 addr_state, gfp_t gfp)
 170 {
 171         struct sctp_sockaddr_entry *addr;
 172
 173         /* Add the address to the bind address list.  */
 174         addr = t_new(struct sctp_sockaddr_entry, gfp);
 175         if (!addr)
 176                 return -ENOMEM;
 177
 178         memcpy(&addr->a, new, sizeof(*new));
 179
 180         /* Fix up the port if it has not yet been set.
 181          * Both v4 and v6 have the port at the same offset.
 182          */
 183         if (!addr->a.v4.sin_port)
 184                 addr->a.v4.sin_port = htons(bp->port);
 185
 186         addr->state = addr_state;
 187         addr->valid = 1;
 188
 189         INIT_LIST_HEAD(&addr->list);
 190
 191         /* We always hold a socket lock when calling this function,
 192          * and that acts as a writer synchronizing lock.
 193          */
 194         list_add_tail_rcu(&addr->list, &bp->address_list);
 195         SCTP_DBG_OBJCNT_INC(addr);
 196
 197         return 0;
 198 }
 199
 200 /* Delete an address from the bind address list in the SCTP_bind_addr
 201  * structure.
 202  */
 203 int sctp_del_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *del_addr)
 204 {
 205         struct sctp_sockaddr_entry *addr, *temp;
 206         int found = 0;
 207
 208         /* We hold the socket lock when calling this function,
 209          * and that acts as a writer synchronizing lock.
 210          */
 211         list_for_each_entry_safe(addr, temp, &bp->address_list, list) {
 212                 if (sctp_cmp_addr_exact(&addr->a, del_addr)) {
 213                         /* Found the exact match. */
 214                         found = 1;
 215                         addr->valid = 0;
 216                         list_del_rcu(&addr->list);
 217                         break;
 218                 }
 219         }
 220
 221         if (found) {
 222                 call_rcu(&addr->rcu, sctp_local_addr_free);
 223                 SCTP_DBG_OBJCNT_DEC(addr);
 224                 return 0;
 225         }
 226
 227         return -EINVAL;
 228 }
 229
 230 /* Create a network byte-order representation of all the addresses
 231  * formated as SCTP parameters.
 232  *
 233  * The second argument is the return value for the length.
 234  */
 235 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
 236                                          int *addrs_len,
 237                                          gfp_t gfp)
 238 {
 239         union sctp_params addrparms;
 240         union sctp_params retval;
 241         int addrparms_len;
 242         union sctp_addr_param rawaddr;
 243         int len;
 244         struct sctp_sockaddr_entry *addr;
 245         struct list_head *pos;
 246         struct sctp_af *af;
 247
 248         addrparms_len = 0;
 249         len = 0;
 250
 251         /* Allocate enough memory at once. */
 252         list_for_each(pos, &bp->address_list) {
 253                 len += sizeof(union sctp_addr_param);
 254         }
 255
 256         /* Don't even bother embedding an address if there
 257          * is only one.
 258          */
 259         if (len == sizeof(union sctp_addr_param)) {
 260                 retval.v = NULL;
 261                 goto end_raw;
 262         }
 263
 264         retval.v = kmalloc(len, gfp);
 265         if (!retval.v)
 266                 goto end_raw;
 267
 268         addrparms = retval;
 269
 270         list_for_each_entry(addr, &bp->address_list, list) {
 271                 af = sctp_get_af_specific(addr->a.v4.sin_family);
 272                 len = af->to_addr_param(&addr->a, &rawaddr);
 273                 memcpy(addrparms.v, &rawaddr, len);
 274                 addrparms.v += len;
 275                 addrparms_len += len;
 276         }
 277
 278 end_raw:
 279         *addrs_len = addrparms_len;
 280         return retval;
 281 }
 282
 283 /*
 284  * Create an address list out of the raw address list format (IPv4 and IPv6
 285  * address parameters).
 286  */
 287 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list,
 288                            int addrs_len, __u16 port, gfp_t gfp)
 289 {
 290         union sctp_addr_param *rawaddr;
 291         struct sctp_paramhdr *param;
 292         union sctp_addr addr;
 293         int retval = 0;
 294         int len;
 295         struct sctp_af *af;
 296
 297         /* Convert the raw address to standard address format */
 298         while (addrs_len) {
 299                 param = (struct sctp_paramhdr *)raw_addr_list;
 300                 rawaddr = (union sctp_addr_param *)raw_addr_list;
 301
 302                 af = sctp_get_af_specific(param_type2af(param->type));
 303                 if (unlikely(!af)) {
 304                         retval = -EINVAL;
 305                         sctp_bind_addr_clean(bp);
 306                         break;
 307                 }
 308
 309                 af->from_addr_param(&addr, rawaddr, htons(port), 0);
 310                 retval = sctp_add_bind_addr(bp, &addr, SCTP_ADDR_SRC, gfp);
 311                 if (retval) {
 312                         /* Can't finish building the list, clean up. */
 313                         sctp_bind_addr_clean(bp);
 314                         break;
 315                 }
 316
 317                 len = ntohs(param->length);
 318                 addrs_len -= len;
 319                 raw_addr_list += len;
 320         }
 321
 322         return retval;
 323 }
 324
 325 /********************************************************************
 326  * 2nd Level Abstractions
 327  ********************************************************************/
 328
 329 /* Does this contain a specified address?  Allow wildcarding. */
 330 int sctp_bind_addr_match(struct sctp_bind_addr *bp,
 331                          const union sctp_addr *addr,
 332                          struct sctp_sock *opt)
 333 {
 334         struct sctp_sockaddr_entry *laddr;
 335         int match = 0;
 336
 337         rcu_read_lock();
 338         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 339                 if (!laddr->valid)
 340                         continue;
 341                 if (opt->pf->cmp_addr(&laddr->a, addr, opt)) {
 342                         match = 1;
 343                         break;
 344                 }
 345         }
 346         rcu_read_unlock();
 347
 348         return match;
 349 }
 350
 351 /* Does the address 'addr' conflict with any addresses in
 352  * the bp.
 353  */
 354 int sctp_bind_addr_conflict(struct sctp_bind_addr *bp,
 355                             const union sctp_addr *addr,
 356                             struct sctp_sock *bp_sp,
 357                             struct sctp_sock *addr_sp)
 358 {
 359         struct sctp_sockaddr_entry *laddr;
 360         int conflict = 0;
 361         struct sctp_sock *sp;
 362
 363         /* Pick the IPv6 socket as the basis of comparison
 364          * since it's usually a superset of the IPv4.
 365          * If there is no IPv6 socket, then default to bind_addr.
 366          */
 367         if (sctp_opt2sk(bp_sp)->sk_family == AF_INET6)
 368                 sp = bp_sp;
 369         else if (sctp_opt2sk(addr_sp)->sk_family == AF_INET6)
 370                 sp = addr_sp;
 371         else
 372                 sp = bp_sp;
 373
 374         rcu_read_lock();
 375         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 376                 if (!laddr->valid)
 377                         continue;
 378
 379                 conflict = sp->pf->cmp_addr(&laddr->a, addr, sp);
 380                 if (conflict)
 381                         break;
 382         }
 383         rcu_read_unlock();
 384
 385         return conflict;
 386 }
 387
 388 /* Get the state of the entry in the bind_addr_list */
 389 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
 390                          const union sctp_addr *addr)
 391 {
 392         struct sctp_sockaddr_entry *laddr;
 393         struct sctp_af *af;
 394         int state = -1;
 395
 396         af = sctp_get_af_specific(addr->sa.sa_family);
 397         if (unlikely(!af))
 398                 return state;
 399
 400         rcu_read_lock();
 401         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 402                 if (!laddr->valid)
 403                         continue;
 404                 if (af->cmp_addr(&laddr->a, addr)) {
 405                         state = laddr->state;
 406                         break;
 407                 }
 408         }
 409         rcu_read_unlock();
 410
 411         return state;
 412 }
 413
 414 /* Find the first address in the bind address list that is not present in
 415  * the addrs packed array.
 416  */
 417 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr   *bp,
 418                                         const union sctp_addr   *addrs,
 419                                         int                     addrcnt,
 420                                         struct sctp_sock        *opt)
 421 {
 422         struct sctp_sockaddr_entry      *laddr;
 423         union sctp_addr                 *addr;
 424         void                            *addr_buf;
 425         struct sctp_af                  *af;
 426         int                             i;
 427
 428         /* This is only called sctp_send_asconf_del_ip() and we hold
 429          * the socket lock in that code patch, so that address list
 430          * can't change.
 431          */
 432         list_for_each_entry(laddr, &bp->address_list, list) {
 433                 addr_buf = (union sctp_addr *)addrs;
 434                 for (i = 0; i < addrcnt; i++) {
 435                         addr = (union sctp_addr *)addr_buf;
 436                         af = sctp_get_af_specific(addr->v4.sin_family);
 437                         if (!af)
 438                                 break;
 439
 440                         if (opt->pf->cmp_addr(&laddr->a, addr, opt))
 441                                 break;
 442
 443                         addr_buf += af->sockaddr_len;
 444                 }
 445                 if (i == addrcnt)
 446                         return &laddr->a;
 447         }
 448
 449         return NULL;
 450 }
 451
 452 /* Copy out addresses from the global local address list. */
 453 static int sctp_copy_one_addr(struct sctp_bind_addr *dest,
 454                               union sctp_addr *addr,
 455                               sctp_scope_t scope, gfp_t gfp,
 456                               int flags)
 457 {
 458         int error = 0;
 459
 460         if (sctp_is_any(NULL, addr)) {
 461                 error = sctp_copy_local_addr_list(dest, scope, gfp, flags);
 462         } else if (sctp_in_scope(addr, scope)) {
 463                 /* Now that the address is in scope, check to see if
 464                  * the address type is supported by local sock as
 465                  * well as the remote peer.
 466                  */
 467                 if ((((AF_INET == addr->sa.sa_family) &&
 468                       (flags & SCTP_ADDR4_PEERSUPP))) ||
 469                     (((AF_INET6 == addr->sa.sa_family) &&
 470                       (flags & SCTP_ADDR6_ALLOWED) &&
 471                       (flags & SCTP_ADDR6_PEERSUPP))))
 472                         error = sctp_add_bind_addr(dest, addr, SCTP_ADDR_SRC,
 473                                                     gfp);
 474         }
 475
 476         return error;
 477 }
 478
 479 /* Is this a wildcard address?  */
 480 int sctp_is_any(struct sock *sk, const union sctp_addr *addr)
 481 {
 482         unsigned short fam = 0;
 483         struct sctp_af *af;
 484
 485         /* Try to get the right address family */
 486         if (addr->sa.sa_family != AF_UNSPEC)
 487                 fam = addr->sa.sa_family;
 488         else if (sk)
 489                 fam = sk->sk_family;
 490
 491         af = sctp_get_af_specific(fam);
 492         if (!af)
 493                 return 0;
 494
 495         return af->is_any(addr);
 496 }
 497
 498 /* Is 'addr' valid for 'scope'?  */
 499 int sctp_in_scope(const union sctp_addr *addr, sctp_scope_t scope)
 500 {
 501         sctp_scope_t addr_scope = sctp_scope(addr);
 502
 503         /* The unusable SCTP addresses will not be considered with
 504          * any defined scopes.
 505          */
 506         if (SCTP_SCOPE_UNUSABLE == addr_scope)
 507                 return 0;
 508         /*
 509          * For INIT and INIT-ACK address list, let L be the level of
 510          * of requested destination address, sender and receiver
 511          * SHOULD include all of its addresses with level greater
 512          * than or equal to L.
 513          *
 514          * Address scoping can be selectively controlled via sysctl
 515          * option
 516          */
 517         switch (sctp_scope_policy) {
 518         case SCTP_SCOPE_POLICY_DISABLE:
 519                 return 1;
 520         case SCTP_SCOPE_POLICY_ENABLE:
 521                 if (addr_scope <= scope)
 522                         return 1;
 523                 break;
 524         case SCTP_SCOPE_POLICY_PRIVATE:
 525                 if (addr_scope <= scope || SCTP_SCOPE_PRIVATE == addr_scope)
 526                         return 1;
 527                 break;
 528         case SCTP_SCOPE_POLICY_LINK:
 529                 if (addr_scope <= scope || SCTP_SCOPE_LINK == addr_scope)
 530                         return 1;
 531                 break;
 532         default:
 533                 break;
 534         }
 535
 536         return 0;
 537 }
 538
 539 /********************************************************************
 540  * 3rd Level Abstractions
 541  ********************************************************************/
 542
 543 /* What is the scope of 'addr'?  */
 544 sctp_scope_t sctp_scope(const union sctp_addr *addr)
 545 {
 546         struct sctp_af *af;
 547
 548         af = sctp_get_af_specific(addr->sa.sa_family);
 549         if (!af)
 550                 return SCTP_SCOPE_UNUSABLE;
 551
 552         return af->scope((union sctp_addr *)addr);
 553 }