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