root/net/sctp/bind_addr.c

DEFINITIONS

1. sctp_bind_addr_copy
2. sctp_bind_addr_dup
3. sctp_bind_addr_init
4. sctp_bind_addr_clean
5. sctp_bind_addr_free
6. sctp_add_bind_addr
7. sctp_del_bind_addr
8. sctp_bind_addrs_to_raw
9. sctp_raw_to_bind_addrs
10. sctp_bind_addr_match
11. sctp_bind_addrs_check
12. sctp_bind_addr_conflict
13. sctp_bind_addr_state
14. sctp_find_unmatch_addr
15. sctp_copy_one_addr
16. sctp_is_any
17. sctp_in_scope
18. sctp_is_ep_boundall

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* SCTP kernel implementation
   3  * (C) Copyright IBM Corp. 2001, 2003
   4  * Copyright (c) Cisco 1999,2000
   5  * Copyright (c) Motorola 1999,2000,2001
   6  * Copyright (c) La Monte H.P. Yarroll 2001
   7  *
   8  * This file is part of the SCTP kernel implementation.
   9  *
  10  * A collection class to handle the storage of transport addresses.
  11  *
  12  * Please send any bug reports or fixes you make to the
  13  * email address(es):
  14  *    lksctp developers <linux-sctp@vger.kernel.org>
  15  *
  16  * Written or modified by:
  17  *    La Monte H.P. Yarroll <piggy@acm.org>
  18  *    Karl Knutson          <karl@athena.chicago.il.us>
  19  *    Jon Grimm             <jgrimm@us.ibm.com>
  20  *    Daisy Chang           <daisyc@us.ibm.com>
  21  */
  22 
  23 #include <linux/types.h>
  24 #include <linux/slab.h>
  25 #include <linux/in.h>
  26 #include <net/sock.h>
  27 #include <net/ipv6.h>
  28 #include <net/if_inet6.h>
  29 #include <net/sctp/sctp.h>
  30 #include <net/sctp/sm.h>
  31 
  32 /* Forward declarations for internal helpers. */
  33 static int sctp_copy_one_addr(struct net *net, struct sctp_bind_addr *dest,
  34                               union sctp_addr *addr, enum sctp_scope scope,
  35                               gfp_t gfp, int flags);
  36 static void sctp_bind_addr_clean(struct sctp_bind_addr *);
  37 
  38 /* First Level Abstractions. */
  39 
  40 /* Copy 'src' to 'dest' taking 'scope' into account.  Omit addresses
  41  * in 'src' which have a broader scope than 'scope'.
  42  */
  43 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
  44                         const struct sctp_bind_addr *src,
  45                         enum sctp_scope scope, gfp_t gfp,
  46                         int flags)
  47 {
  48         struct sctp_sockaddr_entry *addr;
  49         int error = 0;
  50 
  51         /* All addresses share the same port.  */
  52         dest->port = src->port;
  53 
  54         /* Extract the addresses which are relevant for this scope.  */
  55         list_for_each_entry(addr, &src->address_list, list) {
  56                 error = sctp_copy_one_addr(net, dest, &addr->a, scope,
  57                                            gfp, flags);
  58                 if (error < 0)
  59                         goto out;
  60         }
  61 
  62         /* If there are no addresses matching the scope and
  63          * this is global scope, try to get a link scope address, with
  64          * the assumption that we must be sitting behind a NAT.
  65          */
  66         if (list_empty(&dest->address_list) && (SCTP_SCOPE_GLOBAL == scope)) {
  67                 list_for_each_entry(addr, &src->address_list, list) {
  68                         error = sctp_copy_one_addr(net, dest, &addr->a,
  69                                                    SCTP_SCOPE_LINK, gfp,
  70                                                    flags);
  71                         if (error < 0)
  72                                 goto out;
  73                 }
  74         }
  75 
  76 out:
  77         if (error)
  78                 sctp_bind_addr_clean(dest);
  79 
  80         return error;
  81 }
  82 
  83 /* Exactly duplicate the address lists.  This is necessary when doing
  84  * peer-offs and accepts.  We don't want to put all the current system
  85  * addresses into the endpoint.  That's useless.  But we do want duplicat
  86  * the list of bound addresses that the older endpoint used.
  87  */
  88 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
  89                         const struct sctp_bind_addr *src,
  90                         gfp_t gfp)
  91 {
  92         struct sctp_sockaddr_entry *addr;
  93         int error = 0;
  94 
  95         /* All addresses share the same port.  */
  96         dest->port = src->port;
  97 
  98         list_for_each_entry(addr, &src->address_list, list) {
  99                 error = sctp_add_bind_addr(dest, &addr->a, sizeof(addr->a),
 100                                            1, gfp);
 101                 if (error < 0)
 102                         break;
 103         }
 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         INIT_LIST_HEAD(&bp->address_list);
 114         bp->port = port;
 115 }
 116 
 117 /* Dispose of the address list. */
 118 static void sctp_bind_addr_clean(struct sctp_bind_addr *bp)
 119 {
 120         struct sctp_sockaddr_entry *addr, *temp;
 121 
 122         /* Empty the bind address list. */
 123         list_for_each_entry_safe(addr, temp, &bp->address_list, list) {
 124                 list_del_rcu(&addr->list);
 125                 kfree_rcu(addr, rcu);
 126                 SCTP_DBG_OBJCNT_DEC(addr);
 127         }
 128 }
 129 
 130 /* Dispose of an SCTP_bind_addr structure  */
 131 void sctp_bind_addr_free(struct sctp_bind_addr *bp)
 132 {
 133         /* Empty the bind address list. */
 134         sctp_bind_addr_clean(bp);
 135 }
 136 
 137 /* Add an address to the bind address list in the SCTP_bind_addr structure. */
 138 int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new,
 139                        int new_size, __u8 addr_state, gfp_t gfp)
 140 {
 141         struct sctp_sockaddr_entry *addr;
 142 
 143         /* Add the address to the bind address list.  */
 144         addr = kzalloc(sizeof(*addr), gfp);
 145         if (!addr)
 146                 return -ENOMEM;
 147 
 148         memcpy(&addr->a, new, min_t(size_t, sizeof(*new), new_size));
 149 
 150         /* Fix up the port if it has not yet been set.
 151          * Both v4 and v6 have the port at the same offset.
 152          */
 153         if (!addr->a.v4.sin_port)
 154                 addr->a.v4.sin_port = htons(bp->port);
 155 
 156         addr->state = addr_state;
 157         addr->valid = 1;
 158 
 159         INIT_LIST_HEAD(&addr->list);
 160 
 161         /* We always hold a socket lock when calling this function,
 162          * and that acts as a writer synchronizing lock.
 163          */
 164         list_add_tail_rcu(&addr->list, &bp->address_list);
 165         SCTP_DBG_OBJCNT_INC(addr);
 166 
 167         return 0;
 168 }
 169 
 170 /* Delete an address from the bind address list in the SCTP_bind_addr
 171  * structure.
 172  */
 173 int sctp_del_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *del_addr)
 174 {
 175         struct sctp_sockaddr_entry *addr, *temp;
 176         int found = 0;
 177 
 178         /* We hold the socket lock when calling this function,
 179          * and that acts as a writer synchronizing lock.
 180          */
 181         list_for_each_entry_safe(addr, temp, &bp->address_list, list) {
 182                 if (sctp_cmp_addr_exact(&addr->a, del_addr)) {
 183                         /* Found the exact match. */
 184                         found = 1;
 185                         addr->valid = 0;
 186                         list_del_rcu(&addr->list);
 187                         break;
 188                 }
 189         }
 190 
 191         if (found) {
 192                 kfree_rcu(addr, rcu);
 193                 SCTP_DBG_OBJCNT_DEC(addr);
 194                 return 0;
 195         }
 196 
 197         return -EINVAL;
 198 }
 199 
 200 /* Create a network byte-order representation of all the addresses
 201  * formated as SCTP parameters.
 202  *
 203  * The second argument is the return value for the length.
 204  */
 205 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
 206                                          int *addrs_len,
 207                                          gfp_t gfp)
 208 {
 209         union sctp_params addrparms;
 210         union sctp_params retval;
 211         int addrparms_len;
 212         union sctp_addr_param rawaddr;
 213         int len;
 214         struct sctp_sockaddr_entry *addr;
 215         struct list_head *pos;
 216         struct sctp_af *af;
 217 
 218         addrparms_len = 0;
 219         len = 0;
 220 
 221         /* Allocate enough memory at once. */
 222         list_for_each(pos, &bp->address_list) {
 223                 len += sizeof(union sctp_addr_param);
 224         }
 225 
 226         /* Don't even bother embedding an address if there
 227          * is only one.
 228          */
 229         if (len == sizeof(union sctp_addr_param)) {
 230                 retval.v = NULL;
 231                 goto end_raw;
 232         }
 233 
 234         retval.v = kmalloc(len, gfp);
 235         if (!retval.v)
 236                 goto end_raw;
 237 
 238         addrparms = retval;
 239 
 240         list_for_each_entry(addr, &bp->address_list, list) {
 241                 af = sctp_get_af_specific(addr->a.v4.sin_family);
 242                 len = af->to_addr_param(&addr->a, &rawaddr);
 243                 memcpy(addrparms.v, &rawaddr, len);
 244                 addrparms.v += len;
 245                 addrparms_len += len;
 246         }
 247 
 248 end_raw:
 249         *addrs_len = addrparms_len;
 250         return retval;
 251 }
 252 
 253 /*
 254  * Create an address list out of the raw address list format (IPv4 and IPv6
 255  * address parameters).
 256  */
 257 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list,
 258                            int addrs_len, __u16 port, gfp_t gfp)
 259 {
 260         union sctp_addr_param *rawaddr;
 261         struct sctp_paramhdr *param;
 262         union sctp_addr addr;
 263         int retval = 0;
 264         int len;
 265         struct sctp_af *af;
 266 
 267         /* Convert the raw address to standard address format */
 268         while (addrs_len) {
 269                 param = (struct sctp_paramhdr *)raw_addr_list;
 270                 rawaddr = (union sctp_addr_param *)raw_addr_list;
 271 
 272                 af = sctp_get_af_specific(param_type2af(param->type));
 273                 if (unlikely(!af)) {
 274                         retval = -EINVAL;
 275                         sctp_bind_addr_clean(bp);
 276                         break;
 277                 }
 278 
 279                 af->from_addr_param(&addr, rawaddr, htons(port), 0);
 280                 if (sctp_bind_addr_state(bp, &addr) != -1)
 281                         goto next;
 282                 retval = sctp_add_bind_addr(bp, &addr, sizeof(addr),
 283                                             SCTP_ADDR_SRC, gfp);
 284                 if (retval) {
 285                         /* Can't finish building the list, clean up. */
 286                         sctp_bind_addr_clean(bp);
 287                         break;
 288                 }
 289 
 290 next:
 291                 len = ntohs(param->length);
 292                 addrs_len -= len;
 293                 raw_addr_list += len;
 294         }
 295 
 296         return retval;
 297 }
 298 
 299 /********************************************************************
 300  * 2nd Level Abstractions
 301  ********************************************************************/
 302 
 303 /* Does this contain a specified address?  Allow wildcarding. */
 304 int sctp_bind_addr_match(struct sctp_bind_addr *bp,
 305                          const union sctp_addr *addr,
 306                          struct sctp_sock *opt)
 307 {
 308         struct sctp_sockaddr_entry *laddr;
 309         int match = 0;
 310 
 311         rcu_read_lock();
 312         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 313                 if (!laddr->valid)
 314                         continue;
 315                 if (opt->pf->cmp_addr(&laddr->a, addr, opt)) {
 316                         match = 1;
 317                         break;
 318                 }
 319         }
 320         rcu_read_unlock();
 321 
 322         return match;
 323 }
 324 
 325 int sctp_bind_addrs_check(struct sctp_sock *sp,
 326                           struct sctp_sock *sp2, int cnt2)
 327 {
 328         struct sctp_bind_addr *bp2 = &sp2->ep->base.bind_addr;
 329         struct sctp_bind_addr *bp = &sp->ep->base.bind_addr;
 330         struct sctp_sockaddr_entry *laddr, *laddr2;
 331         bool exist = false;
 332         int cnt = 0;
 333 
 334         rcu_read_lock();
 335         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 336                 list_for_each_entry_rcu(laddr2, &bp2->address_list, list) {
 337                         if (sp->pf->af->cmp_addr(&laddr->a, &laddr2->a) &&
 338                             laddr->valid && laddr2->valid) {
 339                                 exist = true;
 340                                 goto next;
 341                         }
 342                 }
 343                 cnt = 0;
 344                 break;
 345 next:
 346                 cnt++;
 347         }
 348         rcu_read_unlock();
 349 
 350         return (cnt == cnt2) ? 0 : (exist ? -EEXIST : 1);
 351 }
 352 
 353 /* Does the address 'addr' conflict with any addresses in
 354  * the bp.
 355  */
 356 int sctp_bind_addr_conflict(struct sctp_bind_addr *bp,
 357                             const union sctp_addr *addr,
 358                             struct sctp_sock *bp_sp,
 359                             struct sctp_sock *addr_sp)
 360 {
 361         struct sctp_sockaddr_entry *laddr;
 362         int conflict = 0;
 363         struct sctp_sock *sp;
 364 
 365         /* Pick the IPv6 socket as the basis of comparison
 366          * since it's usually a superset of the IPv4.
 367          * If there is no IPv6 socket, then default to bind_addr.
 368          */
 369         if (sctp_opt2sk(bp_sp)->sk_family == AF_INET6)
 370                 sp = bp_sp;
 371         else if (sctp_opt2sk(addr_sp)->sk_family == AF_INET6)
 372                 sp = addr_sp;
 373         else
 374                 sp = bp_sp;
 375 
 376         rcu_read_lock();
 377         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 378                 if (!laddr->valid)
 379                         continue;
 380 
 381                 conflict = sp->pf->cmp_addr(&laddr->a, addr, sp);
 382                 if (conflict)
 383                         break;
 384         }
 385         rcu_read_unlock();
 386 
 387         return conflict;
 388 }
 389 
 390 /* Get the state of the entry in the bind_addr_list */
 391 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
 392                          const union sctp_addr *addr)
 393 {
 394         struct sctp_sockaddr_entry *laddr;
 395         struct sctp_af *af;
 396 
 397         af = sctp_get_af_specific(addr->sa.sa_family);
 398         if (unlikely(!af))
 399                 return -1;
 400 
 401         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 402                 if (!laddr->valid)
 403                         continue;
 404                 if (af->cmp_addr(&laddr->a, addr))
 405                         return laddr->state;
 406         }
 407 
 408         return -1;
 409 }
 410 
 411 /* Find the first address in the bind address list that is not present in
 412  * the addrs packed array.
 413  */
 414 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr   *bp,
 415                                         const union sctp_addr   *addrs,
 416                                         int                     addrcnt,
 417                                         struct sctp_sock        *opt)
 418 {
 419         struct sctp_sockaddr_entry      *laddr;
 420         union sctp_addr                 *addr;
 421         void                            *addr_buf;
 422         struct sctp_af                  *af;
 423         int                             i;
 424 
 425         /* This is only called sctp_send_asconf_del_ip() and we hold
 426          * the socket lock in that code patch, so that address list
 427          * can't change.
 428          */
 429         list_for_each_entry(laddr, &bp->address_list, list) {
 430                 addr_buf = (union sctp_addr *)addrs;
 431                 for (i = 0; i < addrcnt; i++) {
 432                         addr = addr_buf;
 433                         af = sctp_get_af_specific(addr->v4.sin_family);
 434                         if (!af)
 435                                 break;
 436 
 437                         if (opt->pf->cmp_addr(&laddr->a, addr, opt))
 438                                 break;
 439 
 440                         addr_buf += af->sockaddr_len;
 441                 }
 442                 if (i == addrcnt)
 443                         return &laddr->a;
 444         }
 445 
 446         return NULL;
 447 }
 448 
 449 /* Copy out addresses from the global local address list. */
 450 static int sctp_copy_one_addr(struct net *net, struct sctp_bind_addr *dest,
 451                               union sctp_addr *addr, enum sctp_scope scope,
 452                               gfp_t gfp, int flags)
 453 {
 454         int error = 0;
 455 
 456         if (sctp_is_any(NULL, addr)) {
 457                 error = sctp_copy_local_addr_list(net, dest, scope, gfp, flags);
 458         } else if (sctp_in_scope(net, addr, scope)) {
 459                 /* Now that the address is in scope, check to see if
 460                  * the address type is supported by local sock as
 461                  * well as the remote peer.
 462                  */
 463                 if ((((AF_INET == addr->sa.sa_family) &&
 464                       (flags & SCTP_ADDR4_PEERSUPP))) ||
 465                     (((AF_INET6 == addr->sa.sa_family) &&
 466                       (flags & SCTP_ADDR6_ALLOWED) &&
 467                       (flags & SCTP_ADDR6_PEERSUPP))))
 468                         error = sctp_add_bind_addr(dest, addr, sizeof(*addr),
 469                                                    SCTP_ADDR_SRC, gfp);
 470         }
 471 
 472         return error;
 473 }
 474 
 475 /* Is this a wildcard address?  */
 476 int sctp_is_any(struct sock *sk, const union sctp_addr *addr)
 477 {
 478         unsigned short fam = 0;
 479         struct sctp_af *af;
 480 
 481         /* Try to get the right address family */
 482         if (addr->sa.sa_family != AF_UNSPEC)
 483                 fam = addr->sa.sa_family;
 484         else if (sk)
 485                 fam = sk->sk_family;
 486 
 487         af = sctp_get_af_specific(fam);
 488         if (!af)
 489                 return 0;
 490 
 491         return af->is_any(addr);
 492 }
 493 
 494 /* Is 'addr' valid for 'scope'?  */
 495 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
 496                   enum sctp_scope scope)
 497 {
 498         enum sctp_scope addr_scope = sctp_scope(addr);
 499 
 500         /* The unusable SCTP addresses will not be considered with
 501          * any defined scopes.
 502          */
 503         if (SCTP_SCOPE_UNUSABLE == addr_scope)
 504                 return 0;
 505         /*
 506          * For INIT and INIT-ACK address list, let L be the level of
 507          * of requested destination address, sender and receiver
 508          * SHOULD include all of its addresses with level greater
 509          * than or equal to L.
 510          *
 511          * Address scoping can be selectively controlled via sysctl
 512          * option
 513          */
 514         switch (net->sctp.scope_policy) {
 515         case SCTP_SCOPE_POLICY_DISABLE:
 516                 return 1;
 517         case SCTP_SCOPE_POLICY_ENABLE:
 518                 if (addr_scope <= scope)
 519                         return 1;
 520                 break;
 521         case SCTP_SCOPE_POLICY_PRIVATE:
 522                 if (addr_scope <= scope || SCTP_SCOPE_PRIVATE == addr_scope)
 523                         return 1;
 524                 break;
 525         case SCTP_SCOPE_POLICY_LINK:
 526                 if (addr_scope <= scope || SCTP_SCOPE_LINK == addr_scope)
 527                         return 1;
 528                 break;
 529         default:
 530                 break;
 531         }
 532 
 533         return 0;
 534 }
 535 
 536 int sctp_is_ep_boundall(struct sock *sk)
 537 {
 538         struct sctp_bind_addr *bp;
 539         struct sctp_sockaddr_entry *addr;
 540 
 541         bp = &sctp_sk(sk)->ep->base.bind_addr;
 542         if (sctp_list_single_entry(&bp->address_list)) {
 543                 addr = list_entry(bp->address_list.next,
 544                                   struct sctp_sockaddr_entry, list);
 545                 if (sctp_is_any(sk, &addr->a))
 546                         return 1;
 547         }
 548         return 0;
 549 }
 550 
 551 /********************************************************************
 552  * 3rd Level Abstractions
 553  ********************************************************************/
 554 
 555 /* What is the scope of 'addr'?  */
 556 enum sctp_scope sctp_scope(const union sctp_addr *addr)
 557 {
 558         struct sctp_af *af;
 559 
 560         af = sctp_get_af_specific(addr->sa.sa_family);
 561         if (!af)
 562                 return SCTP_SCOPE_UNUSABLE;
 563 
 564         return af->scope((union sctp_addr *)addr);
 565 }