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 /* If somehow no addresses were found that can be used with this
77 * scope, it's an error.
78 */
79 if (list_empty(&dest->address_list))
80 error = -ENETUNREACH;
81
82 out:
83 if (error)
84 sctp_bind_addr_clean(dest);
85
86 return error;
87 }
88
89 /* Exactly duplicate the address lists. This is necessary when doing
90 * peer-offs and accepts. We don't want to put all the current system
91 * addresses into the endpoint. That's useless. But we do want duplicat
92 * the list of bound addresses that the older endpoint used.
93 */
94 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
95 const struct sctp_bind_addr *src,
96 gfp_t gfp)
97 {
98 struct sctp_sockaddr_entry *addr;
99 int error = 0;
100
101 /* All addresses share the same port. */
102 dest->port = src->port;
103
104 list_for_each_entry(addr, &src->address_list, list) {
105 error = sctp_add_bind_addr(dest, &addr->a, sizeof(addr->a),
106 1, gfp);
107 if (error < 0)
108 break;
109 }
110
111 return error;
112 }
113
114 /* Initialize the SCTP_bind_addr structure for either an endpoint or
115 * an association.
116 */
117 void sctp_bind_addr_init(struct sctp_bind_addr *bp, __u16 port)
118 {
119 INIT_LIST_HEAD(&bp->address_list);
120 bp->port = port;
121 }
122
123 /* Dispose of the address list. */
124 static void sctp_bind_addr_clean(struct sctp_bind_addr *bp)
125 {
126 struct sctp_sockaddr_entry *addr, *temp;
127
128 /* Empty the bind address list. */
129 list_for_each_entry_safe(addr, temp, &bp->address_list, list) {
130 list_del_rcu(&addr->list);
131 kfree_rcu(addr, rcu);
132 SCTP_DBG_OBJCNT_DEC(addr);
133 }
134 }
135
136 /* Dispose of an SCTP_bind_addr structure */
137 void sctp_bind_addr_free(struct sctp_bind_addr *bp)
138 {
139 /* Empty the bind address list. */
140 sctp_bind_addr_clean(bp);
141 }
142
143 /* Add an address to the bind address list in the SCTP_bind_addr structure. */
144 int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new,
145 int new_size, __u8 addr_state, gfp_t gfp)
146 {
147 struct sctp_sockaddr_entry *addr;
148
149 /* Add the address to the bind address list. */
150 addr = kzalloc(sizeof(*addr), gfp);
151 if (!addr)
152 return -ENOMEM;
153
154 memcpy(&addr->a, new, min_t(size_t, sizeof(*new), new_size));
155
156 /* Fix up the port if it has not yet been set.
157 * Both v4 and v6 have the port at the same offset.
158 */
159 if (!addr->a.v4.sin_port)
160 addr->a.v4.sin_port = htons(bp->port);
161
162 addr->state = addr_state;
163 addr->valid = 1;
164
165 INIT_LIST_HEAD(&addr->list);
166
167 /* We always hold a socket lock when calling this function,
168 * and that acts as a writer synchronizing lock.
169 */
170 list_add_tail_rcu(&addr->list, &bp->address_list);
171 SCTP_DBG_OBJCNT_INC(addr);
172
173 return 0;
174 }
175
176 /* Delete an address from the bind address list in the SCTP_bind_addr
177 * structure.
178 */
179 int sctp_del_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *del_addr)
180 {
181 struct sctp_sockaddr_entry *addr, *temp;
182 int found = 0;
183
184 /* We hold the socket lock when calling this function,
185 * and that acts as a writer synchronizing lock.
186 */
187 list_for_each_entry_safe(addr, temp, &bp->address_list, list) {
188 if (sctp_cmp_addr_exact(&addr->a, del_addr)) {
189 /* Found the exact match. */
190 found = 1;
191 addr->valid = 0;
192 list_del_rcu(&addr->list);
193 break;
194 }
195 }
196
197 if (found) {
198 kfree_rcu(addr, rcu);
199 SCTP_DBG_OBJCNT_DEC(addr);
200 return 0;
201 }
202
203 return -EINVAL;
204 }
205
206 /* Create a network byte-order representation of all the addresses
207 * formated as SCTP parameters.
208 *
209 * The second argument is the return value for the length.
210 */
211 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
212 int *addrs_len,
213 gfp_t gfp)
214 {
215 union sctp_params addrparms;
216 union sctp_params retval;
217 int addrparms_len;
218 union sctp_addr_param rawaddr;
219 int len;
220 struct sctp_sockaddr_entry *addr;
221 struct list_head *pos;
222 struct sctp_af *af;
223
224 addrparms_len = 0;
225 len = 0;
226
227 /* Allocate enough memory at once. */
228 list_for_each(pos, &bp->address_list) {
229 len += sizeof(union sctp_addr_param);
230 }
231
232 /* Don't even bother embedding an address if there
233 * is only one.
234 */
235 if (len == sizeof(union sctp_addr_param)) {
236 retval.v = NULL;
237 goto end_raw;
238 }
239
240 retval.v = kmalloc(len, gfp);
241 if (!retval.v)
242 goto end_raw;
243
244 addrparms = retval;
245
246 list_for_each_entry(addr, &bp->address_list, list) {
247 af = sctp_get_af_specific(addr->a.v4.sin_family);
248 len = af->to_addr_param(&addr->a, &rawaddr);
249 memcpy(addrparms.v, &rawaddr, len);
250 addrparms.v += len;
251 addrparms_len += len;
252 }
253
254 end_raw:
255 *addrs_len = addrparms_len;
256 return retval;
257 }
258
259 /*
260 * Create an address list out of the raw address list format (IPv4 and IPv6
261 * address parameters).
262 */
263 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list,
264 int addrs_len, __u16 port, gfp_t gfp)
265 {
266 union sctp_addr_param *rawaddr;
267 struct sctp_paramhdr *param;
268 union sctp_addr addr;
269 int retval = 0;
270 int len;
271 struct sctp_af *af;
272
273 /* Convert the raw address to standard address format */
274 while (addrs_len) {
275 param = (struct sctp_paramhdr *)raw_addr_list;
276 rawaddr = (union sctp_addr_param *)raw_addr_list;
277
278 af = sctp_get_af_specific(param_type2af(param->type));
279 if (unlikely(!af) ||
280 !af->from_addr_param(&addr, rawaddr, htons(port), 0)) {
281 retval = -EINVAL;
282 goto out_err;
283 }
284
285 if (sctp_bind_addr_state(bp, &addr) != -1)
286 goto next;
287 retval = sctp_add_bind_addr(bp, &addr, sizeof(addr),
288 SCTP_ADDR_SRC, gfp);
289 if (retval)
290 /* Can't finish building the list, clean up. */
291 goto out_err;
292
293 next:
294 len = ntohs(param->length);
295 addrs_len -= len;
296 raw_addr_list += len;
297 }
298
299 return retval;
300
301 out_err:
302 if (retval)
303 sctp_bind_addr_clean(bp);
304
305 return retval;
306 }
307
308 /********************************************************************
309 * 2nd Level Abstractions
310 ********************************************************************/
311
312 /* Does this contain a specified address? Allow wildcarding. */
313 int sctp_bind_addr_match(struct sctp_bind_addr *bp,
314 const union sctp_addr *addr,
315 struct sctp_sock *opt)
316 {
317 struct sctp_sockaddr_entry *laddr;
318 int match = 0;
319
320 rcu_read_lock();
321 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
322 if (!laddr->valid)
323 continue;
324 if (opt->pf->cmp_addr(&laddr->a, addr, opt)) {
325 match = 1;
326 break;
327 }
328 }
329 rcu_read_unlock();
330
331 return match;
332 }
333
334 int sctp_bind_addrs_check(struct sctp_sock *sp,
335 struct sctp_sock *sp2, int cnt2)
336 {
337 struct sctp_bind_addr *bp2 = &sp2->ep->base.bind_addr;
338 struct sctp_bind_addr *bp = &sp->ep->base.bind_addr;
339 struct sctp_sockaddr_entry *laddr, *laddr2;
340 bool exist = false;
341 int cnt = 0;
342
343 rcu_read_lock();
344 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
345 list_for_each_entry_rcu(laddr2, &bp2->address_list, list) {
346 if (sp->pf->af->cmp_addr(&laddr->a, &laddr2->a) &&
347 laddr->valid && laddr2->valid) {
348 exist = true;
349 goto next;
350 }
351 }
352 cnt = 0;
353 break;
354 next:
355 cnt++;
356 }
357 rcu_read_unlock();
358
359 return (cnt == cnt2) ? 0 : (exist ? -EEXIST : 1);
360 }
361
362 /* Does the address 'addr' conflict with any addresses in
363 * the bp.
364 */
365 int sctp_bind_addr_conflict(struct sctp_bind_addr *bp,
366 const union sctp_addr *addr,
367 struct sctp_sock *bp_sp,
368 struct sctp_sock *addr_sp)
369 {
370 struct sctp_sockaddr_entry *laddr;
371 int conflict = 0;
372 struct sctp_sock *sp;
373
374 /* Pick the IPv6 socket as the basis of comparison
375 * since it's usually a superset of the IPv4.
376 * If there is no IPv6 socket, then default to bind_addr.
377 */
378 if (sctp_opt2sk(bp_sp)->sk_family == AF_INET6)
379 sp = bp_sp;
380 else if (sctp_opt2sk(addr_sp)->sk_family == AF_INET6)
381 sp = addr_sp;
382 else
383 sp = bp_sp;
384
385 rcu_read_lock();
386 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
387 if (!laddr->valid)
388 continue;
389
390 conflict = sp->pf->cmp_addr(&laddr->a, addr, sp);
391 if (conflict)
392 break;
393 }
394 rcu_read_unlock();
395
396 return conflict;
397 }
398
399 /* Get the state of the entry in the bind_addr_list */
400 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
401 const union sctp_addr *addr)
402 {
403 struct sctp_sockaddr_entry *laddr;
404 struct sctp_af *af;
405
406 af = sctp_get_af_specific(addr->sa.sa_family);
407 if (unlikely(!af))
408 return -1;
409
410 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
411 if (!laddr->valid)
412 continue;
413 if (af->cmp_addr(&laddr->a, addr))
414 return laddr->state;
415 }
416
417 return -1;
418 }
419
420 /* Find the first address in the bind address list that is not present in
421 * the addrs packed array.
422 */
423 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
424 const union sctp_addr *addrs,
425 int addrcnt,
426 struct sctp_sock *opt)
427 {
428 struct sctp_sockaddr_entry *laddr;
429 union sctp_addr *addr;
430 void *addr_buf;
431 struct sctp_af *af;
432 int i;
433
434 /* This is only called sctp_send_asconf_del_ip() and we hold
435 * the socket lock in that code patch, so that address list
436 * can't change.
437 */
438 list_for_each_entry(laddr, &bp->address_list, list) {
439 addr_buf = (union sctp_addr *)addrs;
440 for (i = 0; i < addrcnt; i++) {
441 addr = addr_buf;
442 af = sctp_get_af_specific(addr->v4.sin_family);
443 if (!af)
444 break;
445
446 if (opt->pf->cmp_addr(&laddr->a, addr, opt))
447 break;
448
449 addr_buf += af->sockaddr_len;
450 }
451 if (i == addrcnt)
452 return &laddr->a;
453 }
454
455 return NULL;
456 }
457
458 /* Copy out addresses from the global local address list. */
459 static int sctp_copy_one_addr(struct net *net, struct sctp_bind_addr *dest,
460 union sctp_addr *addr, enum sctp_scope scope,
461 gfp_t gfp, int flags)
462 {
463 int error = 0;
464
465 if (sctp_is_any(NULL, addr)) {
466 error = sctp_copy_local_addr_list(net, dest, scope, gfp, flags);
467 } else if (sctp_in_scope(net, addr, scope)) {
468 /* Now that the address is in scope, check to see if
469 * the address type is supported by local sock as
470 * well as the remote peer.
471 */
472 if ((((AF_INET == addr->sa.sa_family) &&
473 (flags & SCTP_ADDR4_ALLOWED) &&
474 (flags & SCTP_ADDR4_PEERSUPP))) ||
475 (((AF_INET6 == addr->sa.sa_family) &&
476 (flags & SCTP_ADDR6_ALLOWED) &&
477 (flags & SCTP_ADDR6_PEERSUPP))))
478 error = sctp_add_bind_addr(dest, addr, sizeof(*addr),
479 SCTP_ADDR_SRC, gfp);
480 }
481
482 return error;
483 }
484
485 /* Is this a wildcard address? */
486 int sctp_is_any(struct sock *sk, const union sctp_addr *addr)
487 {
488 unsigned short fam = 0;
489 struct sctp_af *af;
490
491 /* Try to get the right address family */
492 if (addr->sa.sa_family != AF_UNSPEC)
493 fam = addr->sa.sa_family;
494 else if (sk)
495 fam = sk->sk_family;
496
497 af = sctp_get_af_specific(fam);
498 if (!af)
499 return 0;
500
501 return af->is_any(addr);
502 }
503
504 /* Is 'addr' valid for 'scope'? */
505 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
506 enum sctp_scope scope)
507 {
508 enum sctp_scope addr_scope = sctp_scope(addr);
509
510 /* The unusable SCTP addresses will not be considered with
511 * any defined scopes.
512 */
513 if (SCTP_SCOPE_UNUSABLE == addr_scope)
514 return 0;
515 /*
516 * For INIT and INIT-ACK address list, let L be the level of
517 * requested destination address, sender and receiver
518 * SHOULD include all of its addresses with level greater
519 * than or equal to L.
520 *
521 * Address scoping can be selectively controlled via sysctl
522 * option
523 */
524 switch (net->sctp.scope_policy) {
525 case SCTP_SCOPE_POLICY_DISABLE:
526 return 1;
527 case SCTP_SCOPE_POLICY_ENABLE:
528 if (addr_scope <= scope)
529 return 1;
530 break;
531 case SCTP_SCOPE_POLICY_PRIVATE:
532 if (addr_scope <= scope || SCTP_SCOPE_PRIVATE == addr_scope)
533 return 1;
534 break;
535 case SCTP_SCOPE_POLICY_LINK:
536 if (addr_scope <= scope || SCTP_SCOPE_LINK == addr_scope)
537 return 1;
538 break;
539 default:
540 break;
541 }
542
543 return 0;
544 }
545
546 int sctp_is_ep_boundall(struct sock *sk)
547 {
548 struct sctp_bind_addr *bp;
549 struct sctp_sockaddr_entry *addr;
550
551 bp = &sctp_sk(sk)->ep->base.bind_addr;
552 if (sctp_list_single_entry(&bp->address_list)) {
553 addr = list_entry(bp->address_list.next,
554 struct sctp_sockaddr_entry, list);
555 if (sctp_is_any(sk, &addr->a))
556 return 1;
557 }
558 return 0;
559 }
560
561 /********************************************************************
562 * 3rd Level Abstractions
563 ********************************************************************/
564
565 /* What is the scope of 'addr'? */
566 enum sctp_scope sctp_scope(const union sctp_addr *addr)
567 {
568 struct sctp_af *af;
569
570 af = sctp_get_af_specific(addr->sa.sa_family);
571 if (!af)
572 return SCTP_SCOPE_UNUSABLE;
573
574 return af->scope((union sctp_addr *)addr);
575 }
576
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