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, *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 }