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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 <[email protected]>
15 *
16 * Written or modified by:
17 * La Monte H.P. Yarroll <[email protected]>
18 * Karl Knutson <[email protected]>
19 * Jon Grimm <[email protected]>
20 * Daisy Chang <[email protected]>
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. */
33static 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);
36static 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 */
43int 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
82out:
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 */
94int 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 */
117void 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. */
124static 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 */
137void 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. */
144int 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_obj(*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 */
179int 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 */
211union 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
254end_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 */
263int 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 if (addrs_len < sizeof(*param)) {
279 retval = -EINVAL;
280 goto out_err;
281 }
282 len = ntohs(param->length);
283 if (addrs_len < len) {
284 retval = -EINVAL;
285 goto out_err;
286 }
287
288 af = sctp_get_af_specific(param_type2af(param->type));
289 if (unlikely(!af) ||
290 !af->from_addr_param(&addr, rawaddr, htons(port), 0)) {
291 retval = -EINVAL;
292 goto out_err;
293 }
294
295 if (sctp_bind_addr_state(bp, &addr) != -1)
296 goto next;
297 retval = sctp_add_bind_addr(bp, &addr, sizeof(addr),
298 SCTP_ADDR_SRC, gfp);
299 if (retval)
300 /* Can't finish building the list, clean up. */
301 goto out_err;
302
303next:
304 addrs_len -= len;
305 raw_addr_list += len;
306 }
307
308 return retval;
309
310out_err:
311 if (retval)
312 sctp_bind_addr_clean(bp);
313
314 return retval;
315}
316
317/********************************************************************
318 * 2nd Level Abstractions
319 ********************************************************************/
320
321/* Does this contain a specified address? Allow wildcarding. */
322int sctp_bind_addr_match(struct sctp_bind_addr *bp,
323 const union sctp_addr *addr,
324 struct sctp_sock *opt)
325{
326 struct sctp_sockaddr_entry *laddr;
327 int match = 0;
328
329 rcu_read_lock();
330 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
331 if (!laddr->valid)
332 continue;
333 if (opt->pf->cmp_addr(&laddr->a, addr, opt)) {
334 match = 1;
335 break;
336 }
337 }
338 rcu_read_unlock();
339
340 return match;
341}
342
343int sctp_bind_addrs_check(struct sctp_sock *sp,
344 struct sctp_sock *sp2, int cnt2)
345{
346 struct sctp_bind_addr *bp2 = &sp2->ep->base.bind_addr;
347 struct sctp_bind_addr *bp = &sp->ep->base.bind_addr;
348 struct sctp_sockaddr_entry *laddr, *laddr2;
349 bool exist = false;
350 int cnt = 0;
351
352 rcu_read_lock();
353 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
354 list_for_each_entry_rcu(laddr2, &bp2->address_list, list) {
355 if (sp->pf->af->cmp_addr(&laddr->a, &laddr2->a) &&
356 laddr->valid && laddr2->valid) {
357 exist = true;
358 goto next;
359 }
360 }
361 cnt = 0;
362 break;
363next:
364 cnt++;
365 }
366 rcu_read_unlock();
367
368 return (cnt == cnt2) ? 0 : (exist ? -EEXIST : 1);
369}
370
371/* Does the address 'addr' conflict with any addresses in
372 * the bp.
373 */
374int sctp_bind_addr_conflict(struct sctp_bind_addr *bp,
375 const union sctp_addr *addr,
376 struct sctp_sock *bp_sp,
377 struct sctp_sock *addr_sp)
378{
379 struct sctp_sockaddr_entry *laddr;
380 int conflict = 0;
381 struct sctp_sock *sp;
382
383 /* Pick the IPv6 socket as the basis of comparison
384 * since it's usually a superset of the IPv4.
385 * If there is no IPv6 socket, then default to bind_addr.
386 */
387 if (sctp_opt2sk(bp_sp)->sk_family == AF_INET6)
388 sp = bp_sp;
389 else if (sctp_opt2sk(addr_sp)->sk_family == AF_INET6)
390 sp = addr_sp;
391 else
392 sp = bp_sp;
393
394 rcu_read_lock();
395 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
396 if (!laddr->valid)
397 continue;
398
399 conflict = sp->pf->cmp_addr(&laddr->a, addr, sp);
400 if (conflict)
401 break;
402 }
403 rcu_read_unlock();
404
405 return conflict;
406}
407
408/* Get the state of the entry in the bind_addr_list */
409int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
410 const union sctp_addr *addr)
411{
412 struct sctp_sockaddr_entry *laddr;
413 struct sctp_af *af;
414
415 af = sctp_get_af_specific(addr->sa.sa_family);
416 if (unlikely(!af))
417 return -1;
418
419 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
420 if (!laddr->valid)
421 continue;
422 if (af->cmp_addr(&laddr->a, addr))
423 return laddr->state;
424 }
425
426 return -1;
427}
428
429/* Find the first address in the bind address list that is not present in
430 * the addrs packed array.
431 */
432union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
433 const union sctp_addr *addrs,
434 int addrcnt,
435 struct sctp_sock *opt)
436{
437 struct sctp_sockaddr_entry *laddr;
438 union sctp_addr *addr;
439 void *addr_buf;
440 struct sctp_af *af;
441 int i;
442
443 /* This is only called sctp_send_asconf_del_ip() and we hold
444 * the socket lock in that code patch, so that address list
445 * can't change.
446 */
447 list_for_each_entry(laddr, &bp->address_list, list) {
448 addr_buf = (union sctp_addr *)addrs;
449 for (i = 0; i < addrcnt; i++) {
450 addr = addr_buf;
451 af = sctp_get_af_specific(addr->v4.sin_family);
452 if (!af)
453 break;
454
455 if (opt->pf->cmp_addr(&laddr->a, addr, opt))
456 break;
457
458 addr_buf += af->sockaddr_len;
459 }
460 if (i == addrcnt)
461 return &laddr->a;
462 }
463
464 return NULL;
465}
466
467/* Copy out addresses from the global local address list. */
468static int sctp_copy_one_addr(struct net *net, struct sctp_bind_addr *dest,
469 union sctp_addr *addr, enum sctp_scope scope,
470 gfp_t gfp, int flags)
471{
472 int error = 0;
473
474 if (sctp_is_any(NULL, addr)) {
475 error = sctp_copy_local_addr_list(net, dest, scope, gfp, flags);
476 } else if (sctp_in_scope(net, addr, scope)) {
477 /* Now that the address is in scope, check to see if
478 * the address type is supported by local sock as
479 * well as the remote peer.
480 */
481 if ((((AF_INET == addr->sa.sa_family) &&
482 (flags & SCTP_ADDR4_ALLOWED) &&
483 (flags & SCTP_ADDR4_PEERSUPP))) ||
484 (((AF_INET6 == addr->sa.sa_family) &&
485 (flags & SCTP_ADDR6_ALLOWED) &&
486 (flags & SCTP_ADDR6_PEERSUPP))))
487 error = sctp_add_bind_addr(dest, addr, sizeof(*addr),
488 SCTP_ADDR_SRC, gfp);
489 }
490
491 return error;
492}
493
494/* Is this a wildcard address? */
495int sctp_is_any(struct sock *sk, const union sctp_addr *addr)
496{
497 unsigned short fam = 0;
498 struct sctp_af *af;
499
500 /* Try to get the right address family */
501 if (addr->sa.sa_family != AF_UNSPEC)
502 fam = addr->sa.sa_family;
503 else if (sk)
504 fam = sk->sk_family;
505
506 af = sctp_get_af_specific(fam);
507 if (!af)
508 return 0;
509
510 return af->is_any(addr);
511}
512
513/* Is 'addr' valid for 'scope'? */
514int sctp_in_scope(struct net *net, const union sctp_addr *addr,
515 enum sctp_scope scope)
516{
517 enum sctp_scope addr_scope = sctp_scope(addr);
518
519 /* The unusable SCTP addresses will not be considered with
520 * any defined scopes.
521 */
522 if (SCTP_SCOPE_UNUSABLE == addr_scope)
523 return 0;
524 /*
525 * For INIT and INIT-ACK address list, let L be the level of
526 * requested destination address, sender and receiver
527 * SHOULD include all of its addresses with level greater
528 * than or equal to L.
529 *
530 * Address scoping can be selectively controlled via sysctl
531 * option
532 */
533 switch (net->sctp.scope_policy) {
534 case SCTP_SCOPE_POLICY_DISABLE:
535 return 1;
536 case SCTP_SCOPE_POLICY_ENABLE:
537 if (addr_scope <= scope)
538 return 1;
539 break;
540 case SCTP_SCOPE_POLICY_PRIVATE:
541 if (addr_scope <= scope || SCTP_SCOPE_PRIVATE == addr_scope)
542 return 1;
543 break;
544 case SCTP_SCOPE_POLICY_LINK:
545 if (addr_scope <= scope || SCTP_SCOPE_LINK == addr_scope)
546 return 1;
547 break;
548 default:
549 break;
550 }
551
552 return 0;
553}
554
555int sctp_is_ep_boundall(struct sock *sk)
556{
557 struct sctp_bind_addr *bp;
558 struct sctp_sockaddr_entry *addr;
559
560 bp = &sctp_sk(sk)->ep->base.bind_addr;
561 if (sctp_list_single_entry(&bp->address_list)) {
562 addr = list_entry(bp->address_list.next,
563 struct sctp_sockaddr_entry, list);
564 if (sctp_is_any(sk, &addr->a))
565 return 1;
566 }
567 return 0;
568}
569
570/********************************************************************
571 * 3rd Level Abstractions
572 ********************************************************************/
573
574/* What is the scope of 'addr'? */
575enum sctp_scope sctp_scope(const union sctp_addr *addr)
576{
577 struct sctp_af *af;
578
579 af = sctp_get_af_specific(addr->sa.sa_family);
580 if (!af)
581 return SCTP_SCOPE_UNUSABLE;
582
583 return af->scope((union sctp_addr *)addr);
584}