xref: /openbmc/linux/net/sctp/bind_addr.c (revision 32981ea5)
1 /* SCTP kernel 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 implementation.
8  *
9  * A collection class to handle the storage of transport addresses.
10  *
11  * This SCTP 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  * This SCTP 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, see
25  * <http://www.gnu.org/licenses/>.
26  *
27  * Please send any bug reports or fixes you make to the
28  * email address(es):
29  *    lksctp developers <linux-sctp@vger.kernel.org>
30  *
31  * Written or modified by:
32  *    La Monte H.P. Yarroll <piggy@acm.org>
33  *    Karl Knutson          <karl@athena.chicago.il.us>
34  *    Jon Grimm             <jgrimm@us.ibm.com>
35  *    Daisy Chang           <daisyc@us.ibm.com>
36  */
37 
38 #include <linux/types.h>
39 #include <linux/slab.h>
40 #include <linux/in.h>
41 #include <net/sock.h>
42 #include <net/ipv6.h>
43 #include <net/if_inet6.h>
44 #include <net/sctp/sctp.h>
45 #include <net/sctp/sm.h>
46 
47 /* Forward declarations for internal helpers. */
48 static int sctp_copy_one_addr(struct net *, struct sctp_bind_addr *,
49 			      union sctp_addr *, sctp_scope_t scope, gfp_t gfp,
50 			      int flags);
51 static void sctp_bind_addr_clean(struct sctp_bind_addr *);
52 
53 /* First Level Abstractions. */
54 
55 /* Copy 'src' to 'dest' taking 'scope' into account.  Omit addresses
56  * in 'src' which have a broader scope than 'scope'.
57  */
58 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
59 			const struct sctp_bind_addr *src,
60 			sctp_scope_t scope, gfp_t gfp,
61 			int flags)
62 {
63 	struct sctp_sockaddr_entry *addr;
64 	int error = 0;
65 
66 	/* All addresses share the same port.  */
67 	dest->port = src->port;
68 
69 	/* Extract the addresses which are relevant for this scope.  */
70 	list_for_each_entry(addr, &src->address_list, list) {
71 		error = sctp_copy_one_addr(net, dest, &addr->a, scope,
72 					   gfp, flags);
73 		if (error < 0)
74 			goto out;
75 	}
76 
77 	/* If there are no addresses matching the scope and
78 	 * this is global scope, try to get a link scope address, with
79 	 * the assumption that we must be sitting behind a NAT.
80 	 */
81 	if (list_empty(&dest->address_list) && (SCTP_SCOPE_GLOBAL == scope)) {
82 		list_for_each_entry(addr, &src->address_list, list) {
83 			error = sctp_copy_one_addr(net, dest, &addr->a,
84 						   SCTP_SCOPE_LINK, gfp,
85 						   flags);
86 			if (error < 0)
87 				goto out;
88 		}
89 	}
90 
91 out:
92 	if (error)
93 		sctp_bind_addr_clean(dest);
94 
95 	return error;
96 }
97 
98 /* Exactly duplicate the address lists.  This is necessary when doing
99  * peer-offs and accepts.  We don't want to put all the current system
100  * addresses into the endpoint.  That's useless.  But we do want duplicat
101  * the list of bound addresses that the older endpoint used.
102  */
103 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
104 			const struct sctp_bind_addr *src,
105 			gfp_t gfp)
106 {
107 	struct sctp_sockaddr_entry *addr;
108 	int error = 0;
109 
110 	/* All addresses share the same port.  */
111 	dest->port = src->port;
112 
113 	list_for_each_entry(addr, &src->address_list, list) {
114 		error = sctp_add_bind_addr(dest, &addr->a, sizeof(addr->a),
115 					   1, gfp);
116 		if (error < 0)
117 			break;
118 	}
119 
120 	return error;
121 }
122 
123 /* Initialize the SCTP_bind_addr structure for either an endpoint or
124  * an association.
125  */
126 void sctp_bind_addr_init(struct sctp_bind_addr *bp, __u16 port)
127 {
128 	INIT_LIST_HEAD(&bp->address_list);
129 	bp->port = port;
130 }
131 
132 /* Dispose of the address list. */
133 static void sctp_bind_addr_clean(struct sctp_bind_addr *bp)
134 {
135 	struct sctp_sockaddr_entry *addr, *temp;
136 
137 	/* Empty the bind address list. */
138 	list_for_each_entry_safe(addr, temp, &bp->address_list, list) {
139 		list_del_rcu(&addr->list);
140 		kfree_rcu(addr, rcu);
141 		SCTP_DBG_OBJCNT_DEC(addr);
142 	}
143 }
144 
145 /* Dispose of an SCTP_bind_addr structure  */
146 void sctp_bind_addr_free(struct sctp_bind_addr *bp)
147 {
148 	/* Empty the bind address list. */
149 	sctp_bind_addr_clean(bp);
150 }
151 
152 /* Add an address to the bind address list in the SCTP_bind_addr structure. */
153 int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new,
154 		       int new_size, __u8 addr_state, gfp_t gfp)
155 {
156 	struct sctp_sockaddr_entry *addr;
157 
158 	/* Add the address to the bind address list.  */
159 	addr = kzalloc(sizeof(*addr), gfp);
160 	if (!addr)
161 		return -ENOMEM;
162 
163 	memcpy(&addr->a, new, min_t(size_t, sizeof(*new), new_size));
164 
165 	/* Fix up the port if it has not yet been set.
166 	 * Both v4 and v6 have the port at the same offset.
167 	 */
168 	if (!addr->a.v4.sin_port)
169 		addr->a.v4.sin_port = htons(bp->port);
170 
171 	addr->state = addr_state;
172 	addr->valid = 1;
173 
174 	INIT_LIST_HEAD(&addr->list);
175 
176 	/* We always hold a socket lock when calling this function,
177 	 * and that acts as a writer synchronizing lock.
178 	 */
179 	list_add_tail_rcu(&addr->list, &bp->address_list);
180 	SCTP_DBG_OBJCNT_INC(addr);
181 
182 	return 0;
183 }
184 
185 /* Delete an address from the bind address list in the SCTP_bind_addr
186  * structure.
187  */
188 int sctp_del_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *del_addr)
189 {
190 	struct sctp_sockaddr_entry *addr, *temp;
191 	int found = 0;
192 
193 	/* We hold the socket lock when calling this function,
194 	 * and that acts as a writer synchronizing lock.
195 	 */
196 	list_for_each_entry_safe(addr, temp, &bp->address_list, list) {
197 		if (sctp_cmp_addr_exact(&addr->a, del_addr)) {
198 			/* Found the exact match. */
199 			found = 1;
200 			addr->valid = 0;
201 			list_del_rcu(&addr->list);
202 			break;
203 		}
204 	}
205 
206 	if (found) {
207 		kfree_rcu(addr, rcu);
208 		SCTP_DBG_OBJCNT_DEC(addr);
209 		return 0;
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_entry(addr, &bp->address_list, list) {
256 		af = sctp_get_af_specific(addr->a.v4.sin_family);
257 		len = af->to_addr_param(&addr->a, &rawaddr);
258 		memcpy(addrparms.v, &rawaddr, len);
259 		addrparms.v += len;
260 		addrparms_len += len;
261 	}
262 
263 end_raw:
264 	*addrs_len = addrparms_len;
265 	return retval;
266 }
267 
268 /*
269  * Create an address list out of the raw address list format (IPv4 and IPv6
270  * address parameters).
271  */
272 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list,
273 			   int addrs_len, __u16 port, gfp_t gfp)
274 {
275 	union sctp_addr_param *rawaddr;
276 	struct sctp_paramhdr *param;
277 	union sctp_addr addr;
278 	int retval = 0;
279 	int len;
280 	struct sctp_af *af;
281 
282 	/* Convert the raw address to standard address format */
283 	while (addrs_len) {
284 		param = (struct sctp_paramhdr *)raw_addr_list;
285 		rawaddr = (union sctp_addr_param *)raw_addr_list;
286 
287 		af = sctp_get_af_specific(param_type2af(param->type));
288 		if (unlikely(!af)) {
289 			retval = -EINVAL;
290 			sctp_bind_addr_clean(bp);
291 			break;
292 		}
293 
294 		af->from_addr_param(&addr, rawaddr, htons(port), 0);
295 		retval = sctp_add_bind_addr(bp, &addr, sizeof(addr),
296 					    SCTP_ADDR_SRC, 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 /* Does the address 'addr' conflict with any addresses in
338  * the bp.
339  */
340 int sctp_bind_addr_conflict(struct sctp_bind_addr *bp,
341 			    const union sctp_addr *addr,
342 			    struct sctp_sock *bp_sp,
343 			    struct sctp_sock *addr_sp)
344 {
345 	struct sctp_sockaddr_entry *laddr;
346 	int conflict = 0;
347 	struct sctp_sock *sp;
348 
349 	/* Pick the IPv6 socket as the basis of comparison
350 	 * since it's usually a superset of the IPv4.
351 	 * If there is no IPv6 socket, then default to bind_addr.
352 	 */
353 	if (sctp_opt2sk(bp_sp)->sk_family == AF_INET6)
354 		sp = bp_sp;
355 	else if (sctp_opt2sk(addr_sp)->sk_family == AF_INET6)
356 		sp = addr_sp;
357 	else
358 		sp = bp_sp;
359 
360 	rcu_read_lock();
361 	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
362 		if (!laddr->valid)
363 			continue;
364 
365 		conflict = sp->pf->cmp_addr(&laddr->a, addr, sp);
366 		if (conflict)
367 			break;
368 	}
369 	rcu_read_unlock();
370 
371 	return conflict;
372 }
373 
374 /* Get the state of the entry in the bind_addr_list */
375 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
376 			 const union sctp_addr *addr)
377 {
378 	struct sctp_sockaddr_entry *laddr;
379 	struct sctp_af *af;
380 	int state = -1;
381 
382 	af = sctp_get_af_specific(addr->sa.sa_family);
383 	if (unlikely(!af))
384 		return state;
385 
386 	rcu_read_lock();
387 	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
388 		if (!laddr->valid)
389 			continue;
390 		if (af->cmp_addr(&laddr->a, addr)) {
391 			state = laddr->state;
392 			break;
393 		}
394 	}
395 	rcu_read_unlock();
396 
397 	return state;
398 }
399 
400 /* Find the first address in the bind address list that is not present in
401  * the addrs packed array.
402  */
403 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
404 					const union sctp_addr	*addrs,
405 					int			addrcnt,
406 					struct sctp_sock	*opt)
407 {
408 	struct sctp_sockaddr_entry	*laddr;
409 	union sctp_addr			*addr;
410 	void 				*addr_buf;
411 	struct sctp_af			*af;
412 	int				i;
413 
414 	/* This is only called sctp_send_asconf_del_ip() and we hold
415 	 * the socket lock in that code patch, so that address list
416 	 * can't change.
417 	 */
418 	list_for_each_entry(laddr, &bp->address_list, list) {
419 		addr_buf = (union sctp_addr *)addrs;
420 		for (i = 0; i < addrcnt; i++) {
421 			addr = addr_buf;
422 			af = sctp_get_af_specific(addr->v4.sin_family);
423 			if (!af)
424 				break;
425 
426 			if (opt->pf->cmp_addr(&laddr->a, addr, opt))
427 				break;
428 
429 			addr_buf += af->sockaddr_len;
430 		}
431 		if (i == addrcnt)
432 			return &laddr->a;
433 	}
434 
435 	return NULL;
436 }
437 
438 /* Copy out addresses from the global local address list. */
439 static int sctp_copy_one_addr(struct net *net, struct sctp_bind_addr *dest,
440 			      union sctp_addr *addr,
441 			      sctp_scope_t scope, gfp_t gfp,
442 			      int flags)
443 {
444 	int error = 0;
445 
446 	if (sctp_is_any(NULL, addr)) {
447 		error = sctp_copy_local_addr_list(net, dest, scope, gfp, flags);
448 	} else if (sctp_in_scope(net, addr, scope)) {
449 		/* Now that the address is in scope, check to see if
450 		 * the address type is supported by local sock as
451 		 * well as the remote peer.
452 		 */
453 		if ((((AF_INET == addr->sa.sa_family) &&
454 		      (flags & SCTP_ADDR4_PEERSUPP))) ||
455 		    (((AF_INET6 == addr->sa.sa_family) &&
456 		      (flags & SCTP_ADDR6_ALLOWED) &&
457 		      (flags & SCTP_ADDR6_PEERSUPP))))
458 			error = sctp_add_bind_addr(dest, addr, sizeof(*addr),
459 						   SCTP_ADDR_SRC, gfp);
460 	}
461 
462 	return error;
463 }
464 
465 /* Is this a wildcard address?  */
466 int sctp_is_any(struct sock *sk, const union sctp_addr *addr)
467 {
468 	unsigned short fam = 0;
469 	struct sctp_af *af;
470 
471 	/* Try to get the right address family */
472 	if (addr->sa.sa_family != AF_UNSPEC)
473 		fam = addr->sa.sa_family;
474 	else if (sk)
475 		fam = sk->sk_family;
476 
477 	af = sctp_get_af_specific(fam);
478 	if (!af)
479 		return 0;
480 
481 	return af->is_any(addr);
482 }
483 
484 /* Is 'addr' valid for 'scope'?  */
485 int sctp_in_scope(struct net *net, const union sctp_addr *addr, sctp_scope_t scope)
486 {
487 	sctp_scope_t addr_scope = sctp_scope(addr);
488 
489 	/* The unusable SCTP addresses will not be considered with
490 	 * any defined scopes.
491 	 */
492 	if (SCTP_SCOPE_UNUSABLE == addr_scope)
493 		return 0;
494 	/*
495 	 * For INIT and INIT-ACK address list, let L be the level of
496 	 * of requested destination address, sender and receiver
497 	 * SHOULD include all of its addresses with level greater
498 	 * than or equal to L.
499 	 *
500 	 * Address scoping can be selectively controlled via sysctl
501 	 * option
502 	 */
503 	switch (net->sctp.scope_policy) {
504 	case SCTP_SCOPE_POLICY_DISABLE:
505 		return 1;
506 	case SCTP_SCOPE_POLICY_ENABLE:
507 		if (addr_scope <= scope)
508 			return 1;
509 		break;
510 	case SCTP_SCOPE_POLICY_PRIVATE:
511 		if (addr_scope <= scope || SCTP_SCOPE_PRIVATE == addr_scope)
512 			return 1;
513 		break;
514 	case SCTP_SCOPE_POLICY_LINK:
515 		if (addr_scope <= scope || SCTP_SCOPE_LINK == addr_scope)
516 			return 1;
517 		break;
518 	default:
519 		break;
520 	}
521 
522 	return 0;
523 }
524 
525 int sctp_is_ep_boundall(struct sock *sk)
526 {
527 	struct sctp_bind_addr *bp;
528 	struct sctp_sockaddr_entry *addr;
529 
530 	bp = &sctp_sk(sk)->ep->base.bind_addr;
531 	if (sctp_list_single_entry(&bp->address_list)) {
532 		addr = list_entry(bp->address_list.next,
533 				  struct sctp_sockaddr_entry, list);
534 		if (sctp_is_any(sk, &addr->a))
535 			return 1;
536 	}
537 	return 0;
538 }
539 
540 /********************************************************************
541  * 3rd Level Abstractions
542  ********************************************************************/
543 
544 /* What is the scope of 'addr'?  */
545 sctp_scope_t sctp_scope(const union sctp_addr *addr)
546 {
547 	struct sctp_af *af;
548 
549 	af = sctp_get_af_specific(addr->sa.sa_family);
550 	if (!af)
551 		return SCTP_SCOPE_UNUSABLE;
552 
553 	return af->scope((union sctp_addr *)addr);
554 }
555