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, see
  25  * <http://www.gnu.org/licenses/>.
  26  *
  27  * Please send any bug reports or fixes you make to the
  28  * email address(es):
  29  *    lksctp developers <linux-sctp@vger.kernel.org>
  30  *
  31  * Written or modified by:
  32  *    La Monte H.P. Yarroll <piggy@acm.org>
  33  *    Karl Knutson          <karl@athena.chicago.il.us>
  34  *    Jon Grimm             <jgrimm@us.ibm.com>
  35  *    Daisy Chang           <daisyc@us.ibm.com>
  36  */
  37
  38 #include <linux/types.h>
  39 #include <linux/slab.h>
  40 #include <linux/in.h>
  41 #include <net/sock.h>
  42 #include <net/ipv6.h>
  43 #include <net/if_inet6.h>
  44 #include <net/sctp/sctp.h>
  45 #include <net/sctp/sm.h>
  46
  47 /* Forward declarations for internal helpers. */
  48 static int sctp_copy_one_addr(struct net *, struct sctp_bind_addr *,
  49                               union sctp_addr *, sctp_scope_t scope, gfp_t gfp,
  50                               int flags);
  51 static void sctp_bind_addr_clean(struct sctp_bind_addr *);
  52
  53 /* First Level Abstractions. */
  54
  55 /* Copy 'src' to 'dest' taking 'scope' into account.  Omit addresses
  56  * in 'src' which have a broader scope than 'scope'.
  57  */
  58 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
  59                         const struct sctp_bind_addr *src,
  60                         sctp_scope_t scope, gfp_t gfp,
  61                         int flags)
  62 {
  63         struct sctp_sockaddr_entry *addr;
  64         int error = 0;
  65
  66         /* All addresses share the same port.  */
  67         dest->port = src->port;
  68
  69         /* Extract the addresses which are relevant for this scope.  */
  70         list_for_each_entry(addr, &src->address_list, list) {
  71                 error = sctp_copy_one_addr(net, dest, &addr->a, scope,
  72                                            gfp, flags);
  73                 if (error < 0)
  74                         goto out;
  75         }
  76
  77         /* If there are no addresses matching the scope and
  78          * this is global scope, try to get a link scope address, with
  79          * the assumption that we must be sitting behind a NAT.
  80          */
  81         if (list_empty(&dest->address_list) && (SCTP_SCOPE_GLOBAL == scope)) {
  82                 list_for_each_entry(addr, &src->address_list, list) {
  83                         error = sctp_copy_one_addr(net, dest, &addr->a,
  84                                                    SCTP_SCOPE_LINK, gfp,
  85                                                    flags);
  86                         if (error < 0)
  87                                 goto out;
  88                 }
  89         }
  90
  91 out:
  92         if (error)
  93                 sctp_bind_addr_clean(dest);
  94
  95         return error;
  96 }
  97
  98 /* Exactly duplicate the address lists.  This is necessary when doing
  99  * peer-offs and accepts.  We don't want to put all the current system
 100  * addresses into the endpoint.  That's useless.  But we do want duplicat
 101  * the list of bound addresses that the older endpoint used.
 102  */
 103 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
 104                         const struct sctp_bind_addr *src,
 105                         gfp_t gfp)
 106 {
 107         struct sctp_sockaddr_entry *addr;
 108         int error = 0;
 109
 110         /* All addresses share the same port.  */
 111         dest->port = src->port;
 112
 113         list_for_each_entry(addr, &src->address_list, list) {
 114                 error = sctp_add_bind_addr(dest, &addr->a, sizeof(addr->a),
 115                                            1, gfp);
 116                 if (error < 0)
 117                         break;
 118         }
 119
 120         return error;
 121 }
 122
 123 /* Initialize the SCTP_bind_addr structure for either an endpoint or
 124  * an association.
 125  */
 126 void sctp_bind_addr_init(struct sctp_bind_addr *bp, __u16 port)
 127 {
 128         INIT_LIST_HEAD(&bp->address_list);
 129         bp->port = port;
 130 }
 131
 132 /* Dispose of the address list. */
 133 static void sctp_bind_addr_clean(struct sctp_bind_addr *bp)
 134 {
 135         struct sctp_sockaddr_entry *addr, *temp;
 136
 137         /* Empty the bind address list. */
 138         list_for_each_entry_safe(addr, temp, &bp->address_list, list) {
 139                 list_del_rcu(&addr->list);
 140                 kfree_rcu(addr, rcu);
 141                 SCTP_DBG_OBJCNT_DEC(addr);
 142         }
 143 }
 144
 145 /* Dispose of an SCTP_bind_addr structure  */
 146 void sctp_bind_addr_free(struct sctp_bind_addr *bp)
 147 {
 148         /* Empty the bind address list. */
 149         sctp_bind_addr_clean(bp);
 150 }
 151
 152 /* Add an address to the bind address list in the SCTP_bind_addr structure. */
 153 int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new,
 154                        int new_size, __u8 addr_state, gfp_t gfp)
 155 {
 156         struct sctp_sockaddr_entry *addr;
 157
 158         /* Add the address to the bind address list.  */
 159         addr = kzalloc(sizeof(*addr), gfp);
 160         if (!addr)
 161                 return -ENOMEM;
 162
 163         memcpy(&addr->a, new, min_t(size_t, sizeof(*new), new_size));
 164
 165         /* Fix up the port if it has not yet been set.
 166          * Both v4 and v6 have the port at the same offset.
 167          */
 168         if (!addr->a.v4.sin_port)
 169                 addr->a.v4.sin_port = htons(bp->port);
 170
 171         addr->state = addr_state;
 172         addr->valid = 1;
 173
 174         INIT_LIST_HEAD(&addr->list);
 175
 176         /* We always hold a socket lock when calling this function,
 177          * and that acts as a writer synchronizing lock.
 178          */
 179         list_add_tail_rcu(&addr->list, &bp->address_list);
 180         SCTP_DBG_OBJCNT_INC(addr);
 181
 182         return 0;
 183 }
 184
 185 /* Delete an address from the bind address list in the SCTP_bind_addr
 186  * structure.
 187  */
 188 int sctp_del_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *del_addr)
 189 {
 190         struct sctp_sockaddr_entry *addr, *temp;
 191         int found = 0;
 192
 193         /* We hold the socket lock when calling this function,
 194          * and that acts as a writer synchronizing lock.
 195          */
 196         list_for_each_entry_safe(addr, temp, &bp->address_list, list) {
 197                 if (sctp_cmp_addr_exact(&addr->a, del_addr)) {
 198                         /* Found the exact match. */
 199                         found = 1;
 200                         addr->valid = 0;
 201                         list_del_rcu(&addr->list);
 202                         break;
 203                 }
 204         }
 205
 206         if (found) {
 207                 kfree_rcu(addr, rcu);
 208                 SCTP_DBG_OBJCNT_DEC(addr);
 209                 return 0;
 210         }
 211
 212         return -EINVAL;
 213 }
 214
 215 /* Create a network byte-order representation of all the addresses
 216  * formated as SCTP parameters.
 217  *
 218  * The second argument is the return value for the length.
 219  */
 220 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
 221                                          int *addrs_len,
 222                                          gfp_t gfp)
 223 {
 224         union sctp_params addrparms;
 225         union sctp_params retval;
 226         int addrparms_len;
 227         union sctp_addr_param rawaddr;
 228         int len;
 229         struct sctp_sockaddr_entry *addr;
 230         struct list_head *pos;
 231         struct sctp_af *af;
 232
 233         addrparms_len = 0;
 234         len = 0;
 235
 236         /* Allocate enough memory at once. */
 237         list_for_each(pos, &bp->address_list) {
 238                 len += sizeof(union sctp_addr_param);
 239         }
 240
 241         /* Don't even bother embedding an address if there
 242          * is only one.
 243          */
 244         if (len == sizeof(union sctp_addr_param)) {
 245                 retval.v = NULL;
 246                 goto end_raw;
 247         }
 248
 249         retval.v = kmalloc(len, gfp);
 250         if (!retval.v)
 251                 goto end_raw;
 252
 253         addrparms = retval;
 254
 255         list_for_each_entry(addr, &bp->address_list, list) {
 256                 af = sctp_get_af_specific(addr->a.v4.sin_family);
 257                 len = af->to_addr_param(&addr->a, &rawaddr);
 258                 memcpy(addrparms.v, &rawaddr, len);
 259                 addrparms.v += len;
 260                 addrparms_len += len;
 261         }
 262
 263 end_raw:
 264         *addrs_len = addrparms_len;
 265         return retval;
 266 }
 267
 268 /*
 269  * Create an address list out of the raw address list format (IPv4 and IPv6
 270  * address parameters).
 271  */
 272 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list,
 273                            int addrs_len, __u16 port, gfp_t gfp)
 274 {
 275         union sctp_addr_param *rawaddr;
 276         struct sctp_paramhdr *param;
 277         union sctp_addr addr;
 278         int retval = 0;
 279         int len;
 280         struct sctp_af *af;
 281
 282         /* Convert the raw address to standard address format */
 283         while (addrs_len) {
 284                 param = (struct sctp_paramhdr *)raw_addr_list;
 285                 rawaddr = (union sctp_addr_param *)raw_addr_list;
 286
 287                 af = sctp_get_af_specific(param_type2af(param->type));
 288                 if (unlikely(!af)) {
 289                         retval = -EINVAL;
 290                         sctp_bind_addr_clean(bp);
 291                         break;
 292                 }
 293
 294                 af->from_addr_param(&addr, rawaddr, htons(port), 0);
 295                 if (sctp_bind_addr_state(bp, &addr) != -1)
 296                         goto next;
 297                 retval = sctp_add_bind_addr(bp, &addr, sizeof(addr),
 298                                             SCTP_ADDR_SRC, gfp);
 299                 if (retval) {
 300                         /* Can't finish building the list, clean up. */
 301                         sctp_bind_addr_clean(bp);
 302                         break;
 303                 }
 304
 305 next:
 306                 len = ntohs(param->length);
 307                 addrs_len -= len;
 308                 raw_addr_list += len;
 309         }
 310
 311         return retval;
 312 }
 313
 314 /********************************************************************
 315  * 2nd Level Abstractions
 316  ********************************************************************/
 317
 318 /* Does this contain a specified address?  Allow wildcarding. */
 319 int sctp_bind_addr_match(struct sctp_bind_addr *bp,
 320                          const union sctp_addr *addr,
 321                          struct sctp_sock *opt)
 322 {
 323         struct sctp_sockaddr_entry *laddr;
 324         int match = 0;
 325
 326         rcu_read_lock();
 327         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 328                 if (!laddr->valid)
 329                         continue;
 330                 if (opt->pf->cmp_addr(&laddr->a, addr, opt)) {
 331                         match = 1;
 332                         break;
 333                 }
 334         }
 335         rcu_read_unlock();
 336
 337         return match;
 338 }
 339
 340 /* Does the address 'addr' conflict with any addresses in
 341  * the bp.
 342  */
 343 int sctp_bind_addr_conflict(struct sctp_bind_addr *bp,
 344                             const union sctp_addr *addr,
 345                             struct sctp_sock *bp_sp,
 346                             struct sctp_sock *addr_sp)
 347 {
 348         struct sctp_sockaddr_entry *laddr;
 349         int conflict = 0;
 350         struct sctp_sock *sp;
 351
 352         /* Pick the IPv6 socket as the basis of comparison
 353          * since it's usually a superset of the IPv4.
 354          * If there is no IPv6 socket, then default to bind_addr.
 355          */
 356         if (sctp_opt2sk(bp_sp)->sk_family == AF_INET6)
 357                 sp = bp_sp;
 358         else if (sctp_opt2sk(addr_sp)->sk_family == AF_INET6)
 359                 sp = addr_sp;
 360         else
 361                 sp = bp_sp;
 362
 363         rcu_read_lock();
 364         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 365                 if (!laddr->valid)
 366                         continue;
 367
 368                 conflict = sp->pf->cmp_addr(&laddr->a, addr, sp);
 369                 if (conflict)
 370                         break;
 371         }
 372         rcu_read_unlock();
 373
 374         return conflict;
 375 }
 376
 377 /* Get the state of the entry in the bind_addr_list */
 378 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
 379                          const union sctp_addr *addr)
 380 {
 381         struct sctp_sockaddr_entry *laddr;
 382         struct sctp_af *af;
 383         int state = -1;
 384
 385         af = sctp_get_af_specific(addr->sa.sa_family);
 386         if (unlikely(!af))
 387                 return state;
 388
 389         rcu_read_lock();
 390         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 391                 if (!laddr->valid)
 392                         continue;
 393                 if (af->cmp_addr(&laddr->a, addr)) {
 394                         state = laddr->state;
 395                         break;
 396                 }
 397         }
 398         rcu_read_unlock();
 399
 400         return state;
 401 }
 402
 403 /* Find the first address in the bind address list that is not present in
 404  * the addrs packed array.
 405  */
 406 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr   *bp,
 407                                         const union sctp_addr   *addrs,
 408                                         int                     addrcnt,
 409                                         struct sctp_sock        *opt)
 410 {
 411         struct sctp_sockaddr_entry      *laddr;
 412         union sctp_addr                 *addr;
 413         void                            *addr_buf;
 414         struct sctp_af                  *af;
 415         int                             i;
 416
 417         /* This is only called sctp_send_asconf_del_ip() and we hold
 418          * the socket lock in that code patch, so that address list
 419          * can't change.
 420          */
 421         list_for_each_entry(laddr, &bp->address_list, list) {
 422                 addr_buf = (union sctp_addr *)addrs;
 423                 for (i = 0; i < addrcnt; i++) {
 424                         addr = addr_buf;
 425                         af = sctp_get_af_specific(addr->v4.sin_family);
 426                         if (!af)
 427                                 break;
 428
 429                         if (opt->pf->cmp_addr(&laddr->a, addr, opt))
 430                                 break;
 431
 432                         addr_buf += af->sockaddr_len;
 433                 }
 434                 if (i == addrcnt)
 435                         return &laddr->a;
 436         }
 437
 438         return NULL;
 439 }
 440
 441 /* Copy out addresses from the global local address list. */
 442 static int sctp_copy_one_addr(struct net *net, struct sctp_bind_addr *dest,
 443                               union sctp_addr *addr,
 444                               sctp_scope_t scope, gfp_t gfp,
 445                               int flags)
 446 {
 447         int error = 0;
 448
 449         if (sctp_is_any(NULL, addr)) {
 450                 error = sctp_copy_local_addr_list(net, dest, scope, gfp, flags);
 451         } else if (sctp_in_scope(net, addr, scope)) {
 452                 /* Now that the address is in scope, check to see if
 453                  * the address type is supported by local sock as
 454                  * well as the remote peer.
 455                  */
 456                 if ((((AF_INET == addr->sa.sa_family) &&
 457                       (flags & SCTP_ADDR4_PEERSUPP))) ||
 458                     (((AF_INET6 == addr->sa.sa_family) &&
 459                       (flags & SCTP_ADDR6_ALLOWED) &&
 460                       (flags & SCTP_ADDR6_PEERSUPP))))
 461                         error = sctp_add_bind_addr(dest, addr, sizeof(*addr),
 462                                                    SCTP_ADDR_SRC, gfp);
 463         }
 464
 465         return error;
 466 }
 467
 468 /* Is this a wildcard address?  */
 469 int sctp_is_any(struct sock *sk, const union sctp_addr *addr)
 470 {
 471         unsigned short fam = 0;
 472         struct sctp_af *af;
 473
 474         /* Try to get the right address family */
 475         if (addr->sa.sa_family != AF_UNSPEC)
 476                 fam = addr->sa.sa_family;
 477         else if (sk)
 478                 fam = sk->sk_family;
 479
 480         af = sctp_get_af_specific(fam);
 481         if (!af)
 482                 return 0;
 483
 484         return af->is_any(addr);
 485 }
 486
 487 /* Is 'addr' valid for 'scope'?  */
 488 int sctp_in_scope(struct net *net, const union sctp_addr *addr, sctp_scope_t scope)
 489 {
 490         sctp_scope_t addr_scope = sctp_scope(addr);
 491
 492         /* The unusable SCTP addresses will not be considered with
 493          * any defined scopes.
 494          */
 495         if (SCTP_SCOPE_UNUSABLE == addr_scope)
 496                 return 0;
 497         /*
 498          * For INIT and INIT-ACK address list, let L be the level of
 499          * of requested destination address, sender and receiver
 500          * SHOULD include all of its addresses with level greater
 501          * than or equal to L.
 502          *
 503          * Address scoping can be selectively controlled via sysctl
 504          * option
 505          */
 506         switch (net->sctp.scope_policy) {
 507         case SCTP_SCOPE_POLICY_DISABLE:
 508                 return 1;
 509         case SCTP_SCOPE_POLICY_ENABLE:
 510                 if (addr_scope <= scope)
 511                         return 1;
 512                 break;
 513         case SCTP_SCOPE_POLICY_PRIVATE:
 514                 if (addr_scope <= scope || SCTP_SCOPE_PRIVATE == addr_scope)
 515                         return 1;
 516                 break;
 517         case SCTP_SCOPE_POLICY_LINK:
 518                 if (addr_scope <= scope || SCTP_SCOPE_LINK == addr_scope)
 519                         return 1;
 520                 break;
 521         default:
 522                 break;
 523         }
 524
 525         return 0;
 526 }
 527
 528 int sctp_is_ep_boundall(struct sock *sk)
 529 {
 530         struct sctp_bind_addr *bp;
 531         struct sctp_sockaddr_entry *addr;
 532
 533         bp = &sctp_sk(sk)->ep->base.bind_addr;
 534         if (sctp_list_single_entry(&bp->address_list)) {
 535                 addr = list_entry(bp->address_list.next,
 536                                   struct sctp_sockaddr_entry, list);
 537                 if (sctp_is_any(sk, &addr->a))
 538                         return 1;
 539         }
 540         return 0;
 541 }
 542
 543 /********************************************************************
 544  * 3rd Level Abstractions
 545  ********************************************************************/
 546
 547 /* What is the scope of 'addr'?  */
 548 sctp_scope_t sctp_scope(const union sctp_addr *addr)
 549 {
 550         struct sctp_af *af;
 551
 552         af = sctp_get_af_specific(addr->sa.sa_family);
 553         if (!af)
 554                 return SCTP_SCOPE_UNUSABLE;
 555
 556         return af->scope((union sctp_addr *)addr);
 557 }