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 /* Initialize the SCTP_bind_addr structure for either an endpoint or
 109  * an association.
 110  */
 111 void sctp_bind_addr_init(struct sctp_bind_addr *bp, __u16 port)
 112 {
 113         bp->malloced = 0;
 114
 115         INIT_LIST_HEAD(&bp->address_list);
 116         bp->port = port;
 117 }
 118
 119 /* Dispose of the address list. */
 120 static void sctp_bind_addr_clean(struct sctp_bind_addr *bp)
 121 {
 122         struct sctp_sockaddr_entry *addr;
 123         struct list_head *pos, *temp;
 124
 125         /* Empty the bind address list. */
 126         list_for_each_safe(pos, temp, &bp->address_list) {
 127                 addr = list_entry(pos, struct sctp_sockaddr_entry, list);
 128                 list_del(pos);
 129                 kfree(addr);
 130                 SCTP_DBG_OBJCNT_DEC(addr);
 131         }
 132 }
 133
 134 /* Dispose of an SCTP_bind_addr structure  */
 135 void sctp_bind_addr_free(struct sctp_bind_addr *bp)
 136 {
 137         /* Empty the bind address list. */
 138         sctp_bind_addr_clean(bp);
 139
 140         if (bp->malloced) {
 141                 kfree(bp);
 142                 SCTP_DBG_OBJCNT_DEC(bind_addr);
 143         }
 144 }
 145
 146 /* Add an address to the bind address list in the SCTP_bind_addr structure. */
 147 int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new,
 148                        __u8 use_as_src, gfp_t gfp)
 149 {
 150         struct sctp_sockaddr_entry *addr;
 151
 152         /* Add the address to the bind address list.  */
 153         addr = t_new(struct sctp_sockaddr_entry, gfp);
 154         if (!addr)
 155                 return -ENOMEM;
 156
 157         memcpy(&addr->a, new, sizeof(*new));
 158
 159         /* Fix up the port if it has not yet been set.
 160          * Both v4 and v6 have the port at the same offset.
 161          */
 162         if (!addr->a.v4.sin_port)
 163                 addr->a.v4.sin_port = htons(bp->port);
 164
 165         addr->use_as_src = use_as_src;
 166         addr->valid = 1;
 167
 168         INIT_LIST_HEAD(&addr->list);
 169         INIT_RCU_HEAD(&addr->rcu);
 170
 171         /* We always hold a socket lock when calling this function,
 172          * and that acts as a writer synchronizing lock.
 173          */
 174         list_add_tail_rcu(&addr->list, &bp->address_list);
 175         SCTP_DBG_OBJCNT_INC(addr);
 176
 177         return 0;
 178 }
 179
 180 /* Delete an address from the bind address list in the SCTP_bind_addr
 181  * structure.
 182  */
 183 int sctp_del_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *del_addr,
 184                         void fastcall (*rcu_call)(struct rcu_head *head,
 185                                          void (*func)(struct rcu_head *head)))
 186 {
 187         struct sctp_sockaddr_entry *addr, *temp;
 188
 189         /* We hold the socket lock when calling this function,
 190          * and that acts as a writer synchronizing lock.
 191          */
 192         list_for_each_entry_safe(addr, temp, &bp->address_list, list) {
 193                 if (sctp_cmp_addr_exact(&addr->a, del_addr)) {
 194                         /* Found the exact match. */
 195                         addr->valid = 0;
 196                         list_del_rcu(&addr->list);
 197                         break;
 198                 }
 199         }
 200
 201         /* Call the rcu callback provided in the args.  This function is
 202          * called by both BH packet processing and user side socket option
 203          * processing, but it works on different lists in those 2 contexts.
 204          * Each context provides it's own callback, whether call_rcu_bh()
 205          * or call_rcu(), to make sure that we wait for an appropriate time.
 206          */
 207         if (addr && !addr->valid) {
 208                 rcu_call(&addr->rcu, sctp_local_addr_free);
 209                 SCTP_DBG_OBJCNT_DEC(addr);
 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(pos, &bp->address_list) {
 256                 addr = list_entry(pos, struct sctp_sockaddr_entry, list);
 257                 af = sctp_get_af_specific(addr->a.v4.sin_family);
 258                 len = af->to_addr_param(&addr->a, &rawaddr);
 259                 memcpy(addrparms.v, &rawaddr, len);
 260                 addrparms.v += len;
 261                 addrparms_len += len;
 262         }
 263
 264 end_raw:
 265         *addrs_len = addrparms_len;
 266         return retval;
 267 }
 268
 269 /*
 270  * Create an address list out of the raw address list format (IPv4 and IPv6
 271  * address parameters).
 272  */
 273 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list,
 274                            int addrs_len, __u16 port, gfp_t gfp)
 275 {
 276         union sctp_addr_param *rawaddr;
 277         struct sctp_paramhdr *param;
 278         union sctp_addr addr;
 279         int retval = 0;
 280         int len;
 281         struct sctp_af *af;
 282
 283         /* Convert the raw address to standard address format */
 284         while (addrs_len) {
 285                 param = (struct sctp_paramhdr *)raw_addr_list;
 286                 rawaddr = (union sctp_addr_param *)raw_addr_list;
 287
 288                 af = sctp_get_af_specific(param_type2af(param->type));
 289                 if (unlikely(!af)) {
 290                         retval = -EINVAL;
 291                         sctp_bind_addr_clean(bp);
 292                         break;
 293                 }
 294
 295                 af->from_addr_param(&addr, rawaddr, htons(port), 0);
 296                 retval = sctp_add_bind_addr(bp, &addr, 1, gfp);
 297                 if (retval) {
 298                         /* Can't finish building the list, clean up. */
 299                         sctp_bind_addr_clean(bp);
 300                         break;
 301                 }
 302
 303                 len = ntohs(param->length);
 304                 addrs_len -= len;
 305                 raw_addr_list += len;
 306         }
 307
 308         return retval;
 309 }
 310
 311 /********************************************************************
 312  * 2nd Level Abstractions
 313  ********************************************************************/
 314
 315 /* Does this contain a specified address?  Allow wildcarding. */
 316 int sctp_bind_addr_match(struct sctp_bind_addr *bp,
 317                          const union sctp_addr *addr,
 318                          struct sctp_sock *opt)
 319 {
 320         struct sctp_sockaddr_entry *laddr;
 321         int match = 0;
 322
 323         rcu_read_lock();
 324         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 325                 if (!laddr->valid)
 326                         continue;
 327                 if (opt->pf->cmp_addr(&laddr->a, addr, opt)) {
 328                         match = 1;
 329                         break;
 330                 }
 331         }
 332         rcu_read_unlock();
 333
 334         return match;
 335 }
 336
 337 /* Find the first address in the bind address list that is not present in
 338  * the addrs packed array.
 339  */
 340 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr   *bp,
 341                                         const union sctp_addr   *addrs,
 342                                         int                     addrcnt,
 343                                         struct sctp_sock        *opt)
 344 {
 345         struct sctp_sockaddr_entry      *laddr;
 346         union sctp_addr                 *addr;
 347         void                            *addr_buf;
 348         struct sctp_af                  *af;
 349         int                             i;
 350
 351         /* This is only called sctp_send_asconf_del_ip() and we hold
 352          * the socket lock in that code patch, so that address list
 353          * can't change.
 354          */
 355         list_for_each_entry(laddr, &bp->address_list, list) {
 356                 addr_buf = (union sctp_addr *)addrs;
 357                 for (i = 0; i < addrcnt; i++) {
 358                         addr = (union sctp_addr *)addr_buf;
 359                         af = sctp_get_af_specific(addr->v4.sin_family);
 360                         if (!af)
 361                                 break;
 362
 363                         if (opt->pf->cmp_addr(&laddr->a, addr, opt))
 364                                 break;
 365
 366                         addr_buf += af->sockaddr_len;
 367                 }
 368                 if (i == addrcnt)
 369                         return &laddr->a;
 370         }
 371
 372         return NULL;
 373 }
 374
 375 /* Copy out addresses from the global local address list. */
 376 static int sctp_copy_one_addr(struct sctp_bind_addr *dest,
 377                               union sctp_addr *addr,
 378                               sctp_scope_t scope, gfp_t gfp,
 379                               int flags)
 380 {
 381         int error = 0;
 382
 383         if (sctp_is_any(addr)) {
 384                 error = sctp_copy_local_addr_list(dest, scope, gfp, flags);
 385         } else if (sctp_in_scope(addr, scope)) {
 386                 /* Now that the address is in scope, check to see if
 387                  * the address type is supported by local sock as
 388                  * well as the remote peer.
 389                  */
 390                 if ((((AF_INET == addr->sa.sa_family) &&
 391                       (flags & SCTP_ADDR4_PEERSUPP))) ||
 392                     (((AF_INET6 == addr->sa.sa_family) &&
 393                       (flags & SCTP_ADDR6_ALLOWED) &&
 394                       (flags & SCTP_ADDR6_PEERSUPP))))
 395                         error = sctp_add_bind_addr(dest, addr, 1, gfp);
 396         }
 397
 398         return error;
 399 }
 400
 401 /* Is this a wildcard address?  */
 402 int sctp_is_any(const union sctp_addr *addr)
 403 {
 404         struct sctp_af *af = sctp_get_af_specific(addr->sa.sa_family);
 405         if (!af)
 406                 return 0;
 407         return af->is_any(addr);
 408 }
 409
 410 /* Is 'addr' valid for 'scope'?  */
 411 int sctp_in_scope(const union sctp_addr *addr, sctp_scope_t scope)
 412 {
 413         sctp_scope_t addr_scope = sctp_scope(addr);
 414
 415         /* The unusable SCTP addresses will not be considered with
 416          * any defined scopes.
 417          */
 418         if (SCTP_SCOPE_UNUSABLE == addr_scope)
 419                 return 0;
 420         /*
 421          * For INIT and INIT-ACK address list, let L be the level of
 422          * of requested destination address, sender and receiver
 423          * SHOULD include all of its addresses with level greater
 424          * than or equal to L.
 425          */
 426         if (addr_scope <= scope)
 427                 return 1;
 428
 429         return 0;
 430 }
 431
 432 /********************************************************************
 433  * 3rd Level Abstractions
 434  ********************************************************************/
 435
 436 /* What is the scope of 'addr'?  */
 437 sctp_scope_t sctp_scope(const union sctp_addr *addr)
 438 {
 439         struct sctp_af *af;
 440
 441         af = sctp_get_af_specific(addr->sa.sa_family);
 442         if (!af)
 443                 return SCTP_SCOPE_UNUSABLE;
 444
 445         return af->scope((union sctp_addr *)addr);
 446 }