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