xref: /linux/net/sctp/bind_addr.c (revision 6e8331ac6973435b1e7604c30f2ad394035b46e1)
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. */
55 static int sctp_copy_one_addr(struct sctp_bind_addr *, union sctp_addr *,
56 			      sctp_scope_t scope, gfp_t gfp,
57 			      int flags);
58 static 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  */
65 int 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 
102 out:
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  */
112 void 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. */
121 static 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  */
136 void 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. */
148 int 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  */
178 int 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  */
203 union 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 
247 end_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  */
256 int 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. */
299 int 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  */
318 union 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. */
353 static 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?  */
379 int 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'?  */
388 int 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'?  */
414 sctp_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