xref: /openbmc/linux/net/sctp/bind_addr.c (revision c537b994)
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. */
54 static int sctp_copy_one_addr(struct sctp_bind_addr *, union sctp_addr *,
55 			      sctp_scope_t scope, gfp_t gfp,
56 			      int flags);
57 static 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  */
64 int 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 
101 out:
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  */
111 void 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. */
120 static 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  */
135 void 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. */
147 int 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  */
177 int 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  */
202 union 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 
246 end_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  */
255 int 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. */
298 int 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  */
317 union 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. */
352 static 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?  */
378 int 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'?  */
387 int 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'?  */
413 sctp_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