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. */
54static int sctp_copy_one_addr(struct sctp_bind_addr *, union sctp_addr *,
55			      sctp_scope_t scope, gfp_t gfp,
56			      int flags);
57static 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 */
64int 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
101out:
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 */
111void 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. */
120static 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  */
135void 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. */
147int 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
167	INIT_LIST_HEAD(&addr->list);
168	list_add_tail(&addr->list, &bp->address_list);
169	SCTP_DBG_OBJCNT_INC(addr);
170
171	return 0;
172}
173
174/* Delete an address from the bind address list in the SCTP_bind_addr
175 * structure.
176 */
177int sctp_del_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *del_addr)
178{
179	struct list_head *pos, *temp;
180	struct sctp_sockaddr_entry *addr;
181
182	list_for_each_safe(pos, temp, &bp->address_list) {
183		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
184		if (sctp_cmp_addr_exact(&addr->a, del_addr)) {
185			/* Found the exact match. */
186			list_del(pos);
187			kfree(addr);
188			SCTP_DBG_OBJCNT_DEC(addr);
189
190			return 0;
191		}
192	}
193
194	return -EINVAL;
195}
196
197/* Create a network byte-order representation of all the addresses
198 * formated as SCTP parameters.
199 *
200 * The second argument is the return value for the length.
201 */
202union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
203					 int *addrs_len,
204					 gfp_t gfp)
205{
206	union sctp_params addrparms;
207	union sctp_params retval;
208	int addrparms_len;
209	union sctp_addr_param rawaddr;
210	int len;
211	struct sctp_sockaddr_entry *addr;
212	struct list_head *pos;
213	struct sctp_af *af;
214
215	addrparms_len = 0;
216	len = 0;
217
218	/* Allocate enough memory at once. */
219	list_for_each(pos, &bp->address_list) {
220		len += sizeof(union sctp_addr_param);
221	}
222
223	/* Don't even bother embedding an address if there
224	 * is only one.
225	 */
226	if (len == sizeof(union sctp_addr_param)) {
227		retval.v = NULL;
228		goto end_raw;
229	}
230
231	retval.v = kmalloc(len, gfp);
232	if (!retval.v)
233		goto end_raw;
234
235	addrparms = retval;
236
237	list_for_each(pos, &bp->address_list) {
238		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
239		af = sctp_get_af_specific(addr->a.v4.sin_family);
240		len = af->to_addr_param(&addr->a, &rawaddr);
241		memcpy(addrparms.v, &rawaddr, len);
242		addrparms.v += len;
243		addrparms_len += len;
244	}
245
246end_raw:
247	*addrs_len = addrparms_len;
248	return retval;
249}
250
251/*
252 * Create an address list out of the raw address list format (IPv4 and IPv6
253 * address parameters).
254 */
255int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list,
256			   int addrs_len, __u16 port, gfp_t gfp)
257{
258	union sctp_addr_param *rawaddr;
259	struct sctp_paramhdr *param;
260	union sctp_addr addr;
261	int retval = 0;
262	int len;
263	struct sctp_af *af;
264
265	/* Convert the raw address to standard address format */
266	while (addrs_len) {
267		param = (struct sctp_paramhdr *)raw_addr_list;
268		rawaddr = (union sctp_addr_param *)raw_addr_list;
269
270		af = sctp_get_af_specific(param_type2af(param->type));
271		if (unlikely(!af)) {
272			retval = -EINVAL;
273			sctp_bind_addr_clean(bp);
274			break;
275		}
276
277		af->from_addr_param(&addr, rawaddr, htons(port), 0);
278		retval = sctp_add_bind_addr(bp, &addr, 1, gfp);
279		if (retval) {
280			/* Can't finish building the list, clean up. */
281			sctp_bind_addr_clean(bp);
282			break;
283		}
284
285		len = ntohs(param->length);
286		addrs_len -= len;
287		raw_addr_list += len;
288	}
289
290	return retval;
291}
292
293/********************************************************************
294 * 2nd Level Abstractions
295 ********************************************************************/
296
297/* Does this contain a specified address?  Allow wildcarding. */
298int sctp_bind_addr_match(struct sctp_bind_addr *bp,
299			 const union sctp_addr *addr,
300			 struct sctp_sock *opt)
301{
302	struct sctp_sockaddr_entry *laddr;
303	struct list_head *pos;
304
305	list_for_each(pos, &bp->address_list) {
306		laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
307		if (opt->pf->cmp_addr(&laddr->a, addr, opt))
308			return 1;
309	}
310
311	return 0;
312}
313
314/* Find the first address in the bind address list that is not present in
315 * the addrs packed array.
316 */
317union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
318					const union sctp_addr	*addrs,
319					int			addrcnt,
320					struct sctp_sock	*opt)
321{
322	struct sctp_sockaddr_entry	*laddr;
323	union sctp_addr			*addr;
324	void 				*addr_buf;
325	struct sctp_af			*af;
326	struct list_head		*pos;
327	int				i;
328
329	list_for_each(pos, &bp->address_list) {
330		laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
331
332		addr_buf = (union sctp_addr *)addrs;
333		for (i = 0; i < addrcnt; i++) {
334			addr = (union sctp_addr *)addr_buf;
335			af = sctp_get_af_specific(addr->v4.sin_family);
336			if (!af)
337				return NULL;
338
339			if (opt->pf->cmp_addr(&laddr->a, addr, opt))
340				break;
341
342			addr_buf += af->sockaddr_len;
343		}
344		if (i == addrcnt)
345			return &laddr->a;
346	}
347
348	return NULL;
349}
350
351/* Copy out addresses from the global local address list. */
352static int sctp_copy_one_addr(struct sctp_bind_addr *dest,
353			      union sctp_addr *addr,
354			      sctp_scope_t scope, gfp_t gfp,
355			      int flags)
356{
357	int error = 0;
358
359	if (sctp_is_any(addr)) {
360		error = sctp_copy_local_addr_list(dest, scope, gfp, flags);
361	} else if (sctp_in_scope(addr, scope)) {
362		/* Now that the address is in scope, check to see if
363		 * the address type is supported by local sock as
364		 * well as the remote peer.
365		 */
366		if ((((AF_INET == addr->sa.sa_family) &&
367		      (flags & SCTP_ADDR4_PEERSUPP))) ||
368		    (((AF_INET6 == addr->sa.sa_family) &&
369		      (flags & SCTP_ADDR6_ALLOWED) &&
370		      (flags & SCTP_ADDR6_PEERSUPP))))
371			error = sctp_add_bind_addr(dest, addr, 1, gfp);
372	}
373
374	return error;
375}
376
377/* Is this a wildcard address?  */
378int sctp_is_any(const union sctp_addr *addr)
379{
380	struct sctp_af *af = sctp_get_af_specific(addr->sa.sa_family);
381	if (!af)
382		return 0;
383	return af->is_any(addr);
384}
385
386/* Is 'addr' valid for 'scope'?  */
387int sctp_in_scope(const union sctp_addr *addr, sctp_scope_t scope)
388{
389	sctp_scope_t addr_scope = sctp_scope(addr);
390
391	/* The unusable SCTP addresses will not be considered with
392	 * any defined scopes.
393	 */
394	if (SCTP_SCOPE_UNUSABLE == addr_scope)
395		return 0;
396	/*
397	 * For INIT and INIT-ACK address list, let L be the level of
398	 * of requested destination address, sender and receiver
399	 * SHOULD include all of its addresses with level greater
400	 * than or equal to L.
401	 */
402	if (addr_scope <= scope)
403		return 1;
404
405	return 0;
406}
407
408/********************************************************************
409 * 3rd Level Abstractions
410 ********************************************************************/
411
412/* What is the scope of 'addr'?  */
413sctp_scope_t sctp_scope(const union sctp_addr *addr)
414{
415	struct sctp_af *af;
416
417	af = sctp_get_af_specific(addr->sa.sa_family);
418	if (!af)
419		return SCTP_SCOPE_UNUSABLE;
420
421	return af->scope((union sctp_addr *)addr);
422}
423