bind_addr.c revision dc022a9874d026c7d1635ae66d1afafc5f053731 
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/sched.h>
47#include <linux/in.h>
48#include <net/sock.h>
49#include <net/ipv6.h>
50#include <net/if_inet6.h>
51#include <net/sctp/sctp.h>
52#include <net/sctp/sm.h>
53
54/* Forward declarations for internal helpers. */
55static int sctp_copy_one_addr(struct sctp_bind_addr *, union sctp_addr *,
56			      sctp_scope_t scope, gfp_t gfp,
57			      int flags);
58static void sctp_bind_addr_clean(struct sctp_bind_addr *);
59
60/* First Level Abstractions. */
61
62/* Copy 'src' to 'dest' taking 'scope' into account.  Omit addresses
63 * in 'src' which have a broader scope than 'scope'.
64 */
65int sctp_bind_addr_copy(struct sctp_bind_addr *dest,
66			const struct sctp_bind_addr *src,
67			sctp_scope_t scope, gfp_t gfp,
68			int flags)
69{
70	struct sctp_sockaddr_entry *addr;
71	struct list_head *pos;
72	int error = 0;
73
74	/* All addresses share the same port.  */
75	dest->port = src->port;
76
77	/* Extract the addresses which are relevant for this scope.  */
78	list_for_each(pos, &src->address_list) {
79		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
80		error = sctp_copy_one_addr(dest, &addr->a, scope,
81					   gfp, flags);
82		if (error < 0)
83			goto out;
84	}
85
86	/* If there are no addresses matching the scope and
87	 * this is global scope, try to get a link scope address, with
88	 * the assumption that we must be sitting behind a NAT.
89	 */
90	if (list_empty(&dest->address_list) && (SCTP_SCOPE_GLOBAL == scope)) {
91		list_for_each(pos, &src->address_list) {
92			addr = list_entry(pos, struct sctp_sockaddr_entry,
93					  list);
94			error = sctp_copy_one_addr(dest, &addr->a,
95						   SCTP_SCOPE_LINK, gfp,
96						   flags);
97			if (error < 0)
98				goto out;
99		}
100	}
101
102out:
103	if (error)
104		sctp_bind_addr_clean(dest);
105
106	return error;
107}
108
109/* Initialize the SCTP_bind_addr structure for either an endpoint or
110 * an association.
111 */
112void sctp_bind_addr_init(struct sctp_bind_addr *bp, __u16 port)
113{
114	bp->malloced = 0;
115
116	INIT_LIST_HEAD(&bp->address_list);
117	bp->port = port;
118}
119
120/* Dispose of the address list. */
121static void sctp_bind_addr_clean(struct sctp_bind_addr *bp)
122{
123	struct sctp_sockaddr_entry *addr;
124	struct list_head *pos, *temp;
125
126	/* Empty the bind address list. */
127	list_for_each_safe(pos, temp, &bp->address_list) {
128		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
129		list_del(pos);
130		kfree(addr);
131		SCTP_DBG_OBJCNT_DEC(addr);
132	}
133}
134
135/* Dispose of an SCTP_bind_addr structure  */
136void sctp_bind_addr_free(struct sctp_bind_addr *bp)
137{
138	/* Empty the bind address list. */
139	sctp_bind_addr_clean(bp);
140
141	if (bp->malloced) {
142		kfree(bp);
143		SCTP_DBG_OBJCNT_DEC(bind_addr);
144	}
145}
146
147/* Add an address to the bind address list in the SCTP_bind_addr structure. */
148int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new,
149		       __u8 use_as_src, gfp_t gfp)
150{
151	struct sctp_sockaddr_entry *addr;
152
153	/* Add the address to the bind address list.  */
154	addr = t_new(struct sctp_sockaddr_entry, gfp);
155	if (!addr)
156		return -ENOMEM;
157
158	memcpy(&addr->a, new, sizeof(*new));
159
160	/* Fix up the port if it has not yet been set.
161	 * Both v4 and v6 have the port at the same offset.
162	 */
163	if (!addr->a.v4.sin_port)
164		addr->a.v4.sin_port = bp->port;
165
166	addr->use_as_src = use_as_src;
167
168	INIT_LIST_HEAD(&addr->list);
169	list_add_tail(&addr->list, &bp->address_list);
170	SCTP_DBG_OBJCNT_INC(addr);
171
172	return 0;
173}
174
175/* Delete an address from the bind address list in the SCTP_bind_addr
176 * structure.
177 */
178int sctp_del_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *del_addr)
179{
180	struct list_head *pos, *temp;
181	struct sctp_sockaddr_entry *addr;
182
183	list_for_each_safe(pos, temp, &bp->address_list) {
184		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
185		if (sctp_cmp_addr_exact(&addr->a, del_addr)) {
186			/* Found the exact match. */
187			list_del(pos);
188			kfree(addr);
189			SCTP_DBG_OBJCNT_DEC(addr);
190
191			return 0;
192		}
193	}
194
195	return -EINVAL;
196}
197
198/* Create a network byte-order representation of all the addresses
199 * formated as SCTP parameters.
200 *
201 * The second argument is the return value for the length.
202 */
203union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
204					 int *addrs_len,
205					 gfp_t gfp)
206{
207	union sctp_params addrparms;
208	union sctp_params retval;
209	int addrparms_len;
210	union sctp_addr_param rawaddr;
211	int len;
212	struct sctp_sockaddr_entry *addr;
213	struct list_head *pos;
214	struct sctp_af *af;
215
216	addrparms_len = 0;
217	len = 0;
218
219	/* Allocate enough memory at once. */
220	list_for_each(pos, &bp->address_list) {
221		len += sizeof(union sctp_addr_param);
222	}
223
224	/* Don't even bother embedding an address if there
225	 * is only one.
226	 */
227	if (len == sizeof(union sctp_addr_param)) {
228		retval.v = NULL;
229		goto end_raw;
230	}
231
232	retval.v = kmalloc(len, gfp);
233	if (!retval.v)
234		goto end_raw;
235
236	addrparms = retval;
237
238	list_for_each(pos, &bp->address_list) {
239		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
240		af = sctp_get_af_specific(addr->a.v4.sin_family);
241		len = af->to_addr_param(&addr->a, &rawaddr);
242		memcpy(addrparms.v, &rawaddr, len);
243		addrparms.v += len;
244		addrparms_len += len;
245	}
246
247end_raw:
248	*addrs_len = addrparms_len;
249	return retval;
250}
251
252/*
253 * Create an address list out of the raw address list format (IPv4 and IPv6
254 * address parameters).
255 */
256int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list,
257			   int addrs_len, __u16 port, gfp_t gfp)
258{
259	union sctp_addr_param *rawaddr;
260	struct sctp_paramhdr *param;
261	union sctp_addr addr;
262	int retval = 0;
263	int len;
264	struct sctp_af *af;
265
266	/* Convert the raw address to standard address format */
267	while (addrs_len) {
268		param = (struct sctp_paramhdr *)raw_addr_list;
269		rawaddr = (union sctp_addr_param *)raw_addr_list;
270
271		af = sctp_get_af_specific(param_type2af(param->type));
272		if (unlikely(!af)) {
273			retval = -EINVAL;
274			sctp_bind_addr_clean(bp);
275			break;
276		}
277
278		af->from_addr_param(&addr, rawaddr, port, 0);
279		retval = sctp_add_bind_addr(bp, &addr, 1, gfp);
280		if (retval) {
281			/* Can't finish building the list, clean up. */
282			sctp_bind_addr_clean(bp);
283			break;
284		}
285
286		len = ntohs(param->length);
287		addrs_len -= len;
288		raw_addr_list += len;
289	}
290
291	return retval;
292}
293
294/********************************************************************
295 * 2nd Level Abstractions
296 ********************************************************************/
297
298/* Does this contain a specified address?  Allow wildcarding. */
299int sctp_bind_addr_match(struct sctp_bind_addr *bp,
300			 const union sctp_addr *addr,
301			 struct sctp_sock *opt)
302{
303	struct sctp_sockaddr_entry *laddr;
304	struct list_head *pos;
305
306	list_for_each(pos, &bp->address_list) {
307		laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
308		if (opt->pf->cmp_addr(&laddr->a, addr, opt))
309 			return 1;
310	}
311
312	return 0;
313}
314
315/* Find the first address in the bind address list that is not present in
316 * the addrs packed array.
317 */
318union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
319					const union sctp_addr	*addrs,
320					int			addrcnt,
321					struct sctp_sock	*opt)
322{
323	struct sctp_sockaddr_entry	*laddr;
324	union sctp_addr			*addr;
325	void 				*addr_buf;
326	struct sctp_af			*af;
327	struct list_head		*pos;
328	int				i;
329
330	list_for_each(pos, &bp->address_list) {
331		laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
332
333		addr_buf = (union sctp_addr *)addrs;
334		for (i = 0; i < addrcnt; i++) {
335			addr = (union sctp_addr *)addr_buf;
336			af = sctp_get_af_specific(addr->v4.sin_family);
337			if (!af)
338				return NULL;
339
340			if (opt->pf->cmp_addr(&laddr->a, addr, opt))
341				break;
342
343			addr_buf += af->sockaddr_len;
344		}
345		if (i == addrcnt)
346			return &laddr->a;
347	}
348
349	return NULL;
350}
351
352/* Copy out addresses from the global local address list. */
353static int sctp_copy_one_addr(struct sctp_bind_addr *dest,
354			      union sctp_addr *addr,
355			      sctp_scope_t scope, gfp_t gfp,
356			      int flags)
357{
358	int error = 0;
359
360	if (sctp_is_any(addr)) {
361		error = sctp_copy_local_addr_list(dest, scope, gfp, flags);
362	} else if (sctp_in_scope(addr, scope)) {
363		/* Now that the address is in scope, check to see if
364		 * the address type is supported by local sock as
365		 * well as the remote peer.
366		 */
367		if ((((AF_INET == addr->sa.sa_family) &&
368		      (flags & SCTP_ADDR4_PEERSUPP))) ||
369		    (((AF_INET6 == addr->sa.sa_family) &&
370		      (flags & SCTP_ADDR6_ALLOWED) &&
371		      (flags & SCTP_ADDR6_PEERSUPP))))
372			error = sctp_add_bind_addr(dest, addr, 1, gfp);
373	}
374
375	return error;
376}
377
378/* Is this a wildcard address?  */
379int sctp_is_any(const union sctp_addr *addr)
380{
381	struct sctp_af *af = sctp_get_af_specific(addr->sa.sa_family);
382	if (!af)
383		return 0;
384	return af->is_any(addr);
385}
386
387/* Is 'addr' valid for 'scope'?  */
388int sctp_in_scope(const union sctp_addr *addr, sctp_scope_t scope)
389{
390	sctp_scope_t addr_scope = sctp_scope(addr);
391
392	/* The unusable SCTP addresses will not be considered with
393	 * any defined scopes.
394	 */
395	if (SCTP_SCOPE_UNUSABLE == addr_scope)
396		return 0;
397	/*
398	 * For INIT and INIT-ACK address list, let L be the level of
399	 * of requested destination address, sender and receiver
400	 * SHOULD include all of its addresses with level greater
401	 * than or equal to L.
402	 */
403	if (addr_scope <= scope)
404		return 1;
405
406	return 0;
407}
408
409/********************************************************************
410 * 3rd Level Abstractions
411 ********************************************************************/
412
413/* What is the scope of 'addr'?  */
414sctp_scope_t sctp_scope(const union sctp_addr *addr)
415{
416	struct sctp_af *af;
417
418	af = sctp_get_af_specific(addr->sa.sa_family);
419	if (!af)
420		return SCTP_SCOPE_UNUSABLE;
421
422	return af->scope((union sctp_addr *)addr);
423}
424