net/sctp/bind_addr.c

   1 /* SCTP kernel reference 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 reference implementation.
   8  *
   9  * A collection class to handle the storage of transport addresses.
  10  *
  11  * The SCTP reference 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  * The SCTP reference 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         struct list_head *pos;
  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(pos, &src->address_list) {
  78                 addr = list_entry(pos, struct sctp_sockaddr_entry, list);
  79                 error = sctp_copy_one_addr(dest, &addr->a, scope,
  80                                            gfp, flags);
  81                 if (error < 0)
  82                         goto out;
  83         }
  84
  85         /* If there are no addresses matching the scope and
  86          * this is global scope, try to get a link scope address, with
  87          * the assumption that we must be sitting behind a NAT.
  88          */
  89         if (list_empty(&dest->address_list) && (SCTP_SCOPE_GLOBAL == scope)) {
  90                 list_for_each(pos, &src->address_list) {
  91                         addr = list_entry(pos, struct sctp_sockaddr_entry,
  92                                           list);
  93                         error = sctp_copy_one_addr(dest, &addr->a,
  94                                                    SCTP_SCOPE_LINK, gfp,
  95                                                    flags);
  96                         if (error < 0)
  97                                 goto out;
  98                 }
  99         }
 100
 101 out:
 102         if (error)
 103                 sctp_bind_addr_clean(dest);
 104
 105         return error;
 106 }
 107
 108 /* Exactly duplicate the address lists.  This is necessary when doing
 109  * peer-offs and accepts.  We don't want to put all the current system
 110  * addresses into the endpoint.  That's useless.  But we do want duplicat
 111  * the list of bound addresses that the older endpoint used.
 112  */
 113 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
 114                         const struct sctp_bind_addr *src,
 115                         gfp_t gfp)
 116 {
 117         struct sctp_sockaddr_entry *addr;
 118         struct list_head *pos;
 119         int error = 0;
 120
 121         /* All addresses share the same port.  */
 122         dest->port = src->port;
 123
 124         list_for_each(pos, &src->address_list) {
 125                 addr = list_entry(pos, struct sctp_sockaddr_entry, list);
 126                 error = sctp_add_bind_addr(dest, &addr->a, 1, gfp);
 127                 if (error < 0)
 128                         break;
 129         }
 130
 131         return error;
 132 }
 133
 134 /* Initialize the SCTP_bind_addr structure for either an endpoint or
 135  * an association.
 136  */
 137 void sctp_bind_addr_init(struct sctp_bind_addr *bp, __u16 port)
 138 {
 139         bp->malloced = 0;
 140
 141         INIT_LIST_HEAD(&bp->address_list);
 142         bp->port = port;
 143 }
 144
 145 /* Dispose of the address list. */
 146 static void sctp_bind_addr_clean(struct sctp_bind_addr *bp)
 147 {
 148         struct sctp_sockaddr_entry *addr;
 149         struct list_head *pos, *temp;
 150
 151         /* Empty the bind address list. */
 152         list_for_each_safe(pos, temp, &bp->address_list) {
 153                 addr = list_entry(pos, struct sctp_sockaddr_entry, list);
 154                 list_del(pos);
 155                 kfree(addr);
 156                 SCTP_DBG_OBJCNT_DEC(addr);
 157         }
 158 }
 159
 160 /* Dispose of an SCTP_bind_addr structure  */
 161 void sctp_bind_addr_free(struct sctp_bind_addr *bp)
 162 {
 163         /* Empty the bind address list. */
 164         sctp_bind_addr_clean(bp);
 165
 166         if (bp->malloced) {
 167                 kfree(bp);
 168                 SCTP_DBG_OBJCNT_DEC(bind_addr);
 169         }
 170 }
 171
 172 /* Add an address to the bind address list in the SCTP_bind_addr structure. */
 173 int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new,
 174                        __u8 use_as_src, gfp_t gfp)
 175 {
 176         struct sctp_sockaddr_entry *addr;
 177
 178         /* Add the address to the bind address list.  */
 179         addr = t_new(struct sctp_sockaddr_entry, gfp);
 180         if (!addr)
 181                 return -ENOMEM;
 182
 183         memcpy(&addr->a, new, sizeof(*new));
 184
 185         /* Fix up the port if it has not yet been set.
 186          * Both v4 and v6 have the port at the same offset.
 187          */
 188         if (!addr->a.v4.sin_port)
 189                 addr->a.v4.sin_port = htons(bp->port);
 190
 191         addr->use_as_src = use_as_src;
 192         addr->valid = 1;
 193
 194         INIT_LIST_HEAD(&addr->list);
 195         INIT_RCU_HEAD(&addr->rcu);
 196
 197         /* We always hold a socket lock when calling this function,
 198          * and that acts as a writer synchronizing lock.
 199          */
 200         list_add_tail_rcu(&addr->list, &bp->address_list);
 201         SCTP_DBG_OBJCNT_INC(addr);
 202
 203         return 0;
 204 }
 205
 206 /* Delete an address from the bind address list in the SCTP_bind_addr
 207  * structure.
 208  */
 209 int sctp_del_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *del_addr)
 210 {
 211         struct sctp_sockaddr_entry *addr, *temp;
 212
 213         /* We hold the socket lock when calling this function,
 214          * and that acts as a writer synchronizing lock.
 215          */
 216         list_for_each_entry_safe(addr, temp, &bp->address_list, list) {
 217                 if (sctp_cmp_addr_exact(&addr->a, del_addr)) {
 218                         /* Found the exact match. */
 219                         addr->valid = 0;
 220                         list_del_rcu(&addr->list);
 221                         break;
 222                 }
 223         }
 224
 225         if (addr && !addr->valid) {
 226                 call_rcu(&addr->rcu, sctp_local_addr_free);
 227                 SCTP_DBG_OBJCNT_DEC(addr);
 228                 return 0;
 229         }
 230
 231         return -EINVAL;
 232 }
 233
 234 /* Create a network byte-order representation of all the addresses
 235  * formated as SCTP parameters.
 236  *
 237  * The second argument is the return value for the length.
 238  */
 239 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
 240                                          int *addrs_len,
 241                                          gfp_t gfp)
 242 {
 243         union sctp_params addrparms;
 244         union sctp_params retval;
 245         int addrparms_len;
 246         union sctp_addr_param rawaddr;
 247         int len;
 248         struct sctp_sockaddr_entry *addr;
 249         struct list_head *pos;
 250         struct sctp_af *af;
 251
 252         addrparms_len = 0;
 253         len = 0;
 254
 255         /* Allocate enough memory at once. */
 256         list_for_each(pos, &bp->address_list) {
 257                 len += sizeof(union sctp_addr_param);
 258         }
 259
 260         /* Don't even bother embedding an address if there
 261          * is only one.
 262          */
 263         if (len == sizeof(union sctp_addr_param)) {
 264                 retval.v = NULL;
 265                 goto end_raw;
 266         }
 267
 268         retval.v = kmalloc(len, gfp);
 269         if (!retval.v)
 270                 goto end_raw;
 271
 272         addrparms = retval;
 273
 274         list_for_each(pos, &bp->address_list) {
 275                 addr = list_entry(pos, struct sctp_sockaddr_entry, list);
 276                 af = sctp_get_af_specific(addr->a.v4.sin_family);
 277                 len = af->to_addr_param(&addr->a, &rawaddr);
 278                 memcpy(addrparms.v, &rawaddr, len);
 279                 addrparms.v += len;
 280                 addrparms_len += len;
 281         }
 282
 283 end_raw:
 284         *addrs_len = addrparms_len;
 285         return retval;
 286 }
 287
 288 /*
 289  * Create an address list out of the raw address list format (IPv4 and IPv6
 290  * address parameters).
 291  */
 292 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list,
 293                            int addrs_len, __u16 port, gfp_t gfp)
 294 {
 295         union sctp_addr_param *rawaddr;
 296         struct sctp_paramhdr *param;
 297         union sctp_addr addr;
 298         int retval = 0;
 299         int len;
 300         struct sctp_af *af;
 301
 302         /* Convert the raw address to standard address format */
 303         while (addrs_len) {
 304                 param = (struct sctp_paramhdr *)raw_addr_list;
 305                 rawaddr = (union sctp_addr_param *)raw_addr_list;
 306
 307                 af = sctp_get_af_specific(param_type2af(param->type));
 308                 if (unlikely(!af)) {
 309                         retval = -EINVAL;
 310                         sctp_bind_addr_clean(bp);
 311                         break;
 312                 }
 313
 314                 af->from_addr_param(&addr, rawaddr, htons(port), 0);
 315                 retval = sctp_add_bind_addr(bp, &addr, 1, gfp);
 316                 if (retval) {
 317                         /* Can't finish building the list, clean up. */
 318                         sctp_bind_addr_clean(bp);
 319                         break;
 320                 }
 321
 322                 len = ntohs(param->length);
 323                 addrs_len -= len;
 324                 raw_addr_list += len;
 325         }
 326
 327         return retval;
 328 }
 329
 330 /********************************************************************
 331  * 2nd Level Abstractions
 332  ********************************************************************/
 333
 334 /* Does this contain a specified address?  Allow wildcarding. */
 335 int sctp_bind_addr_match(struct sctp_bind_addr *bp,
 336                          const union sctp_addr *addr,
 337                          struct sctp_sock *opt)
 338 {
 339         struct sctp_sockaddr_entry *laddr;
 340         int match = 0;
 341
 342         rcu_read_lock();
 343         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 344                 if (!laddr->valid)
 345                         continue;
 346                 if (opt->pf->cmp_addr(&laddr->a, addr, opt)) {
 347                         match = 1;
 348                         break;
 349                 }
 350         }
 351         rcu_read_unlock();
 352
 353         return match;
 354 }
 355
 356 /* Find the first address in the bind address list that is not present in
 357  * the addrs packed array.
 358  */
 359 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr   *bp,
 360                                         const union sctp_addr   *addrs,
 361                                         int                     addrcnt,
 362                                         struct sctp_sock        *opt)
 363 {
 364         struct sctp_sockaddr_entry      *laddr;
 365         union sctp_addr                 *addr;
 366         void                            *addr_buf;
 367         struct sctp_af                  *af;
 368         int                             i;
 369
 370         /* This is only called sctp_send_asconf_del_ip() and we hold
 371          * the socket lock in that code patch, so that address list
 372          * can't change.
 373          */
 374         list_for_each_entry(laddr, &bp->address_list, list) {
 375                 addr_buf = (union sctp_addr *)addrs;
 376                 for (i = 0; i < addrcnt; i++) {
 377                         addr = (union sctp_addr *)addr_buf;
 378                         af = sctp_get_af_specific(addr->v4.sin_family);
 379                         if (!af)
 380                                 break;
 381
 382                         if (opt->pf->cmp_addr(&laddr->a, addr, opt))
 383                                 break;
 384
 385                         addr_buf += af->sockaddr_len;
 386                 }
 387                 if (i == addrcnt)
 388                         return &laddr->a;
 389         }
 390
 391         return NULL;
 392 }
 393
 394 /* Copy out addresses from the global local address list. */
 395 static int sctp_copy_one_addr(struct sctp_bind_addr *dest,
 396                               union sctp_addr *addr,
 397                               sctp_scope_t scope, gfp_t gfp,
 398                               int flags)
 399 {
 400         int error = 0;
 401
 402         if (sctp_is_any(addr)) {
 403                 error = sctp_copy_local_addr_list(dest, scope, gfp, flags);
 404         } else if (sctp_in_scope(addr, scope)) {
 405                 /* Now that the address is in scope, check to see if
 406                  * the address type is supported by local sock as
 407                  * well as the remote peer.
 408                  */
 409                 if ((((AF_INET == addr->sa.sa_family) &&
 410                       (flags & SCTP_ADDR4_PEERSUPP))) ||
 411                     (((AF_INET6 == addr->sa.sa_family) &&
 412                       (flags & SCTP_ADDR6_ALLOWED) &&
 413                       (flags & SCTP_ADDR6_PEERSUPP))))
 414                         error = sctp_add_bind_addr(dest, addr, 1, gfp);
 415         }
 416
 417         return error;
 418 }
 419
 420 /* Is this a wildcard address?  */
 421 int sctp_is_any(const union sctp_addr *addr)
 422 {
 423         struct sctp_af *af = sctp_get_af_specific(addr->sa.sa_family);
 424         if (!af)
 425                 return 0;
 426         return af->is_any(addr);
 427 }
 428
 429 /* Is 'addr' valid for 'scope'?  */
 430 int sctp_in_scope(const union sctp_addr *addr, sctp_scope_t scope)
 431 {
 432         sctp_scope_t addr_scope = sctp_scope(addr);
 433
 434         /* The unusable SCTP addresses will not be considered with
 435          * any defined scopes.
 436          */
 437         if (SCTP_SCOPE_UNUSABLE == addr_scope)
 438                 return 0;
 439         /*
 440          * For INIT and INIT-ACK address list, let L be the level of
 441          * of requested destination address, sender and receiver
 442          * SHOULD include all of its addresses with level greater
 443          * than or equal to L.
 444          */
 445         if (addr_scope <= scope)
 446                 return 1;
 447
 448         return 0;
 449 }
 450
 451 /********************************************************************
 452  * 3rd Level Abstractions
 453  ********************************************************************/
 454
 455 /* What is the scope of 'addr'?  */
 456 sctp_scope_t sctp_scope(const union sctp_addr *addr)
 457 {
 458         struct sctp_af *af;
 459
 460         af = sctp_get_af_specific(addr->sa.sa_family);
 461         if (!af)
 462                 return SCTP_SCOPE_UNUSABLE;
 463
 464         return af->scope((union sctp_addr *)addr);
 465 }