Linux Audio

Check our new training course

In-person Linux kernel drivers training

Jun 16-20, 2025
Register
Loading...
v3.5.6
  1/* SCTP kernel implementation
  2 * Copyright (c) 1999-2000 Cisco, Inc.
  3 * Copyright (c) 1999-2001 Motorola, Inc.
  4 * Copyright (c) 2001-2002 International Business Machines, Corp.
  5 * Copyright (c) 2001 Intel Corp.
  6 * Copyright (c) 2001 Nokia, Inc.
  7 * Copyright (c) 2001 La Monte H.P. Yarroll
  8 *
  9 * This file is part of the SCTP kernel implementation
 10 *
 11 * This abstraction represents an SCTP endpoint.
 12 *
 13 * The SCTP implementation is free software;
 14 * you can redistribute it and/or modify it under the terms of
 15 * the GNU General Public License as published by
 16 * the Free Software Foundation; either version 2, or (at your option)
 17 * any later version.
 18 *
 19 * The SCTP implementation is distributed in the hope that it
 20 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 21 *                 ************************
 22 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 23 * See the GNU General Public License for more details.
 24 *
 25 * You should have received a copy of the GNU General Public License
 26 * along with GNU CC; see the file COPYING.  If not, write to
 27 * the Free Software Foundation, 59 Temple Place - Suite 330,
 28 * Boston, MA 02111-1307, USA.
 29 *
 30 * Please send any bug reports or fixes you make to the
 31 * email address(es):
 32 *    lksctp developers <lksctp-developers@lists.sourceforge.net>
 33 *
 34 * Or submit a bug report through the following website:
 35 *    http://www.sf.net/projects/lksctp
 36 *
 37 * Written or modified by:
 38 *    La Monte H.P. Yarroll <piggy@acm.org>
 39 *    Karl Knutson <karl@athena.chicago.il.us>
 40 *    Jon Grimm <jgrimm@austin.ibm.com>
 41 *    Daisy Chang <daisyc@us.ibm.com>
 42 *    Dajiang Zhang <dajiang.zhang@nokia.com>
 43 *
 44 * Any bugs reported given to us we will try to fix... any fixes shared will
 45 * be incorporated into the next SCTP release.
 46 */
 47
 48#include <linux/types.h>
 49#include <linux/slab.h>
 50#include <linux/in.h>
 51#include <linux/random.h>	/* get_random_bytes() */
 52#include <linux/crypto.h>
 53#include <net/sock.h>
 54#include <net/ipv6.h>
 55#include <net/sctp/sctp.h>
 56#include <net/sctp/sm.h>
 57
 58/* Forward declarations for internal helpers. */
 59static void sctp_endpoint_bh_rcv(struct work_struct *work);
 60
 61/*
 62 * Initialize the base fields of the endpoint structure.
 63 */
 64static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
 65						struct sock *sk,
 66						gfp_t gfp)
 67{
 
 68	struct sctp_hmac_algo_param *auth_hmacs = NULL;
 69	struct sctp_chunks_param *auth_chunks = NULL;
 70	struct sctp_shared_key *null_key;
 71	int err;
 72
 73	ep->digest = kzalloc(SCTP_SIGNATURE_SIZE, gfp);
 74	if (!ep->digest)
 75		return NULL;
 76
 77	if (sctp_auth_enable) {
 
 78		/* Allocate space for HMACS and CHUNKS authentication
 79		 * variables.  There are arrays that we encode directly
 80		 * into parameters to make the rest of the operations easier.
 81		 */
 82		auth_hmacs = kzalloc(sizeof(sctp_hmac_algo_param_t) +
 83				sizeof(__u16) * SCTP_AUTH_NUM_HMACS, gfp);
 84		if (!auth_hmacs)
 85			goto nomem;
 86
 87		auth_chunks = kzalloc(sizeof(sctp_chunks_param_t) +
 88					SCTP_NUM_CHUNK_TYPES, gfp);
 89		if (!auth_chunks)
 90			goto nomem;
 91
 92		/* Initialize the HMACS parameter.
 93		 * SCTP-AUTH: Section 3.3
 94		 *    Every endpoint supporting SCTP chunk authentication MUST
 95		 *    support the HMAC based on the SHA-1 algorithm.
 96		 */
 97		auth_hmacs->param_hdr.type = SCTP_PARAM_HMAC_ALGO;
 98		auth_hmacs->param_hdr.length =
 99					htons(sizeof(sctp_paramhdr_t) + 2);
100		auth_hmacs->hmac_ids[0] = htons(SCTP_AUTH_HMAC_ID_SHA1);
101
102		/* Initialize the CHUNKS parameter */
103		auth_chunks->param_hdr.type = SCTP_PARAM_CHUNKS;
104		auth_chunks->param_hdr.length = htons(sizeof(sctp_paramhdr_t));
105
106		/* If the Add-IP functionality is enabled, we must
107		 * authenticate, ASCONF and ASCONF-ACK chunks
108		 */
109		if (sctp_addip_enable) {
110			auth_chunks->chunks[0] = SCTP_CID_ASCONF;
111			auth_chunks->chunks[1] = SCTP_CID_ASCONF_ACK;
112			auth_chunks->param_hdr.length =
113					htons(sizeof(sctp_paramhdr_t) + 2);
114		}
115	}
116
117	/* Initialize the base structure. */
118	/* What type of endpoint are we?  */
119	ep->base.type = SCTP_EP_TYPE_SOCKET;
120
121	/* Initialize the basic object fields. */
122	atomic_set(&ep->base.refcnt, 1);
123	ep->base.dead = 0;
124	ep->base.malloced = 1;
125
126	/* Create an input queue.  */
127	sctp_inq_init(&ep->base.inqueue);
128
129	/* Set its top-half handler */
130	sctp_inq_set_th_handler(&ep->base.inqueue, sctp_endpoint_bh_rcv);
131
132	/* Initialize the bind addr area */
133	sctp_bind_addr_init(&ep->base.bind_addr, 0);
134
135	/* Remember who we are attached to.  */
136	ep->base.sk = sk;
137	sock_hold(ep->base.sk);
138
139	/* Create the lists of associations.  */
140	INIT_LIST_HEAD(&ep->asocs);
141
142	/* Use SCTP specific send buffer space queues.  */
143	ep->sndbuf_policy = sctp_sndbuf_policy;
144
145	sk->sk_data_ready = sctp_data_ready;
146	sk->sk_write_space = sctp_write_space;
147	sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
148
149	/* Get the receive buffer policy for this endpoint */
150	ep->rcvbuf_policy = sctp_rcvbuf_policy;
151
152	/* Initialize the secret key used with cookie. */
153	get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE);
154	ep->last_key = ep->current_key = 0;
155	ep->key_changed_at = jiffies;
156
157	/* SCTP-AUTH extensions*/
158	INIT_LIST_HEAD(&ep->endpoint_shared_keys);
159	null_key = sctp_auth_shkey_create(0, GFP_KERNEL);
160	if (!null_key)
161		goto nomem;
162
163	list_add(&null_key->key_list, &ep->endpoint_shared_keys);
164
165	/* Allocate and initialize transorms arrays for suported HMACs. */
166	err = sctp_auth_init_hmacs(ep, gfp);
167	if (err)
168		goto nomem_hmacs;
169
170	/* Add the null key to the endpoint shared keys list and
171	 * set the hmcas and chunks pointers.
172	 */
173	ep->auth_hmacs_list = auth_hmacs;
174	ep->auth_chunk_list = auth_chunks;
175
176	return ep;
177
178nomem_hmacs:
179	sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
180nomem:
181	/* Free all allocations */
182	kfree(auth_hmacs);
183	kfree(auth_chunks);
184	kfree(ep->digest);
185	return NULL;
186
187}
188
189/* Create a sctp_endpoint with all that boring stuff initialized.
190 * Returns NULL if there isn't enough memory.
191 */
192struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, gfp_t gfp)
193{
194	struct sctp_endpoint *ep;
195
196	/* Build a local endpoint. */
197	ep = t_new(struct sctp_endpoint, gfp);
198	if (!ep)
199		goto fail;
 
200	if (!sctp_endpoint_init(ep, sk, gfp))
201		goto fail_init;
202	ep->base.malloced = 1;
203	SCTP_DBG_OBJCNT_INC(ep);
204	return ep;
205
206fail_init:
207	kfree(ep);
208fail:
209	return NULL;
210}
211
212/* Add an association to an endpoint.  */
213void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
214			    struct sctp_association *asoc)
215{
216	struct sock *sk = ep->base.sk;
217
218	/* If this is a temporary association, don't bother
219	 * since we'll be removing it shortly and don't
220	 * want anyone to find it anyway.
221	 */
222	if (asoc->temp)
223		return;
224
225	/* Now just add it to our list of asocs */
226	list_add_tail(&asoc->asocs, &ep->asocs);
227
228	/* Increment the backlog value for a TCP-style listening socket. */
229	if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
230		sk->sk_ack_backlog++;
231}
232
233/* Free the endpoint structure.  Delay cleanup until
234 * all users have released their reference count on this structure.
235 */
236void sctp_endpoint_free(struct sctp_endpoint *ep)
237{
238	ep->base.dead = 1;
239
240	ep->base.sk->sk_state = SCTP_SS_CLOSED;
241
242	/* Unlink this endpoint, so we can't find it again! */
243	sctp_unhash_endpoint(ep);
244
245	sctp_endpoint_put(ep);
246}
247
248/* Final destructor for endpoint.  */
249static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
250{
251	SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return);
252
253	/* Free up the HMAC transform. */
254	crypto_free_hash(sctp_sk(ep->base.sk)->hmac);
 
 
255
256	/* Free the digest buffer */
257	kfree(ep->digest);
258
259	/* SCTP-AUTH: Free up AUTH releated data such as shared keys
260	 * chunks and hmacs arrays that were allocated
261	 */
262	sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
263	kfree(ep->auth_hmacs_list);
264	kfree(ep->auth_chunk_list);
265
266	/* AUTH - Free any allocated HMAC transform containers */
267	sctp_auth_destroy_hmacs(ep->auth_hmacs);
268
269	/* Cleanup. */
270	sctp_inq_free(&ep->base.inqueue);
271	sctp_bind_addr_free(&ep->base.bind_addr);
272
273	/* Remove and free the port */
274	if (sctp_sk(ep->base.sk)->bind_hash)
275		sctp_put_port(ep->base.sk);
276
277	/* Give up our hold on the sock. */
278	if (ep->base.sk)
279		sock_put(ep->base.sk);
 
 
 
280
281	/* Finally, free up our memory. */
282	if (ep->base.malloced) {
283		kfree(ep);
284		SCTP_DBG_OBJCNT_DEC(ep);
285	}
 
 
 
286}
287
288/* Hold a reference to an endpoint. */
289void sctp_endpoint_hold(struct sctp_endpoint *ep)
290{
291	atomic_inc(&ep->base.refcnt);
292}
293
294/* Release a reference to an endpoint and clean up if there are
295 * no more references.
296 */
297void sctp_endpoint_put(struct sctp_endpoint *ep)
298{
299	if (atomic_dec_and_test(&ep->base.refcnt))
300		sctp_endpoint_destroy(ep);
301}
302
303/* Is this the endpoint we are looking for?  */
304struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
 
305					       const union sctp_addr *laddr)
306{
307	struct sctp_endpoint *retval = NULL;
308
309	if (htons(ep->base.bind_addr.port) == laddr->v4.sin_port) {
 
310		if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
311					 sctp_sk(ep->base.sk)))
312			retval = ep;
313	}
314
315	return retval;
316}
317
318/* Find the association that goes with this chunk.
319 * We do a linear search of the associations for this endpoint.
320 * We return the matching transport address too.
321 */
322static struct sctp_association *__sctp_endpoint_lookup_assoc(
323	const struct sctp_endpoint *ep,
324	const union sctp_addr *paddr,
325	struct sctp_transport **transport)
326{
327	struct sctp_association *asoc = NULL;
328	struct sctp_association *tmp;
329	struct sctp_transport *t = NULL;
330	struct sctp_hashbucket *head;
331	struct sctp_ep_common *epb;
332	struct hlist_node *node;
333	int hash;
334	int rport;
335
336	*transport = NULL;
337
338	/* If the local port is not set, there can't be any associations
339	 * on this endpoint.
340	 */
341	if (!ep->base.bind_addr.port)
342		goto out;
 
 
 
343
344	rport = ntohs(paddr->v4.sin_port);
345
346	hash = sctp_assoc_hashfn(ep->base.bind_addr.port, rport);
347	head = &sctp_assoc_hashtable[hash];
348	read_lock(&head->lock);
349	sctp_for_each_hentry(epb, node, &head->chain) {
350		tmp = sctp_assoc(epb);
351		if (tmp->ep != ep || rport != tmp->peer.port)
352			continue;
353
354		t = sctp_assoc_lookup_paddr(tmp, paddr);
355		if (t) {
356			asoc = tmp;
357			*transport = t;
358			break;
359		}
360	}
361	read_unlock(&head->lock);
362out:
363	return asoc;
364}
365
366/* Lookup association on an endpoint based on a peer address.  BH-safe.  */
367struct sctp_association *sctp_endpoint_lookup_assoc(
368	const struct sctp_endpoint *ep,
369	const union sctp_addr *paddr,
370	struct sctp_transport **transport)
371{
372	struct sctp_association *asoc;
373
374	sctp_local_bh_disable();
375	asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport);
376	sctp_local_bh_enable();
377
378	return asoc;
379}
380
381/* Look for any peeled off association from the endpoint that matches the
382 * given peer address.
383 */
384int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
385				const union sctp_addr *paddr)
386{
387	struct sctp_sockaddr_entry *addr;
388	struct sctp_bind_addr *bp;
 
389
390	bp = &ep->base.bind_addr;
391	/* This function is called with the socket lock held,
392	 * so the address_list can not change.
393	 */
394	list_for_each_entry(addr, &bp->address_list, list) {
395		if (sctp_has_association(&addr->a, paddr))
396			return 1;
397	}
398
399	return 0;
400}
401
402/* Do delayed input processing.  This is scheduled by sctp_rcv().
403 * This may be called on BH or task time.
404 */
405static void sctp_endpoint_bh_rcv(struct work_struct *work)
406{
407	struct sctp_endpoint *ep =
408		container_of(work, struct sctp_endpoint,
409			     base.inqueue.immediate);
410	struct sctp_association *asoc;
411	struct sock *sk;
 
412	struct sctp_transport *transport;
413	struct sctp_chunk *chunk;
414	struct sctp_inq *inqueue;
415	sctp_subtype_t subtype;
416	sctp_state_t state;
417	int error = 0;
418	int first_time = 1;	/* is this the first time through the loop */
419
420	if (ep->base.dead)
421		return;
422
423	asoc = NULL;
424	inqueue = &ep->base.inqueue;
425	sk = ep->base.sk;
 
426
427	while (NULL != (chunk = sctp_inq_pop(inqueue))) {
428		subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
429
430		/* If the first chunk in the packet is AUTH, do special
431		 * processing specified in Section 6.3 of SCTP-AUTH spec
432		 */
433		if (first_time && (subtype.chunk == SCTP_CID_AUTH)) {
434			struct sctp_chunkhdr *next_hdr;
435
436			next_hdr = sctp_inq_peek(inqueue);
437			if (!next_hdr)
438				goto normal;
439
440			/* If the next chunk is COOKIE-ECHO, skip the AUTH
441			 * chunk while saving a pointer to it so we can do
442			 * Authentication later (during cookie-echo
443			 * processing).
444			 */
445			if (next_hdr->type == SCTP_CID_COOKIE_ECHO) {
446				chunk->auth_chunk = skb_clone(chunk->skb,
447								GFP_ATOMIC);
448				chunk->auth = 1;
449				continue;
450			}
451		}
452normal:
453		/* We might have grown an association since last we
454		 * looked, so try again.
455		 *
456		 * This happens when we've just processed our
457		 * COOKIE-ECHO chunk.
458		 */
459		if (NULL == chunk->asoc) {
460			asoc = sctp_endpoint_lookup_assoc(ep,
461							  sctp_source(chunk),
462							  &transport);
463			chunk->asoc = asoc;
464			chunk->transport = transport;
465		}
466
467		state = asoc ? asoc->state : SCTP_STATE_CLOSED;
468		if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
469			continue;
470
471		/* Remember where the last DATA chunk came from so we
472		 * know where to send the SACK.
473		 */
474		if (asoc && sctp_chunk_is_data(chunk))
475			asoc->peer.last_data_from = chunk->transport;
476		else
477			SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
 
 
 
478
479		if (chunk->transport)
480			chunk->transport->last_time_heard = jiffies;
481
482		error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, state,
483				   ep, asoc, chunk, GFP_ATOMIC);
484
485		if (error && chunk)
486			chunk->pdiscard = 1;
487
488		/* Check to see if the endpoint is freed in response to
489		 * the incoming chunk. If so, get out of the while loop.
490		 */
491		if (!sctp_sk(sk)->ep)
492			break;
493
494		if (first_time)
495			first_time = 0;
496	}
497}
v4.6
  1/* SCTP kernel implementation
  2 * Copyright (c) 1999-2000 Cisco, Inc.
  3 * Copyright (c) 1999-2001 Motorola, Inc.
  4 * Copyright (c) 2001-2002 International Business Machines, Corp.
  5 * Copyright (c) 2001 Intel Corp.
  6 * Copyright (c) 2001 Nokia, Inc.
  7 * Copyright (c) 2001 La Monte H.P. Yarroll
  8 *
  9 * This file is part of the SCTP kernel implementation
 10 *
 11 * This abstraction represents an SCTP endpoint.
 12 *
 13 * The SCTP implementation is free software;
 14 * you can redistribute it and/or modify it under the terms of
 15 * the GNU General Public License as published by
 16 * the Free Software Foundation; either version 2, or (at your option)
 17 * any later version.
 18 *
 19 * The SCTP implementation is distributed in the hope that it
 20 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 21 *                 ************************
 22 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 23 * See the GNU General Public License for more details.
 24 *
 25 * You should have received a copy of the GNU General Public License
 26 * along with GNU CC; see the file COPYING.  If not, see
 27 * <http://www.gnu.org/licenses/>.
 
 28 *
 29 * Please send any bug reports or fixes you make to the
 30 * email address(es):
 31 *    lksctp developers <linux-sctp@vger.kernel.org>
 
 
 
 32 *
 33 * Written or modified by:
 34 *    La Monte H.P. Yarroll <piggy@acm.org>
 35 *    Karl Knutson <karl@athena.chicago.il.us>
 36 *    Jon Grimm <jgrimm@austin.ibm.com>
 37 *    Daisy Chang <daisyc@us.ibm.com>
 38 *    Dajiang Zhang <dajiang.zhang@nokia.com>
 
 
 
 39 */
 40
 41#include <linux/types.h>
 42#include <linux/slab.h>
 43#include <linux/in.h>
 44#include <linux/random.h>	/* get_random_bytes() */
 
 45#include <net/sock.h>
 46#include <net/ipv6.h>
 47#include <net/sctp/sctp.h>
 48#include <net/sctp/sm.h>
 49
 50/* Forward declarations for internal helpers. */
 51static void sctp_endpoint_bh_rcv(struct work_struct *work);
 52
 53/*
 54 * Initialize the base fields of the endpoint structure.
 55 */
 56static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
 57						struct sock *sk,
 58						gfp_t gfp)
 59{
 60	struct net *net = sock_net(sk);
 61	struct sctp_hmac_algo_param *auth_hmacs = NULL;
 62	struct sctp_chunks_param *auth_chunks = NULL;
 63	struct sctp_shared_key *null_key;
 64	int err;
 65
 66	ep->digest = kzalloc(SCTP_SIGNATURE_SIZE, gfp);
 67	if (!ep->digest)
 68		return NULL;
 69
 70	ep->auth_enable = net->sctp.auth_enable;
 71	if (ep->auth_enable) {
 72		/* Allocate space for HMACS and CHUNKS authentication
 73		 * variables.  There are arrays that we encode directly
 74		 * into parameters to make the rest of the operations easier.
 75		 */
 76		auth_hmacs = kzalloc(sizeof(sctp_hmac_algo_param_t) +
 77				sizeof(__u16) * SCTP_AUTH_NUM_HMACS, gfp);
 78		if (!auth_hmacs)
 79			goto nomem;
 80
 81		auth_chunks = kzalloc(sizeof(sctp_chunks_param_t) +
 82					SCTP_NUM_CHUNK_TYPES, gfp);
 83		if (!auth_chunks)
 84			goto nomem;
 85
 86		/* Initialize the HMACS parameter.
 87		 * SCTP-AUTH: Section 3.3
 88		 *    Every endpoint supporting SCTP chunk authentication MUST
 89		 *    support the HMAC based on the SHA-1 algorithm.
 90		 */
 91		auth_hmacs->param_hdr.type = SCTP_PARAM_HMAC_ALGO;
 92		auth_hmacs->param_hdr.length =
 93					htons(sizeof(sctp_paramhdr_t) + 2);
 94		auth_hmacs->hmac_ids[0] = htons(SCTP_AUTH_HMAC_ID_SHA1);
 95
 96		/* Initialize the CHUNKS parameter */
 97		auth_chunks->param_hdr.type = SCTP_PARAM_CHUNKS;
 98		auth_chunks->param_hdr.length = htons(sizeof(sctp_paramhdr_t));
 99
100		/* If the Add-IP functionality is enabled, we must
101		 * authenticate, ASCONF and ASCONF-ACK chunks
102		 */
103		if (net->sctp.addip_enable) {
104			auth_chunks->chunks[0] = SCTP_CID_ASCONF;
105			auth_chunks->chunks[1] = SCTP_CID_ASCONF_ACK;
106			auth_chunks->param_hdr.length =
107					htons(sizeof(sctp_paramhdr_t) + 2);
108		}
109	}
110
111	/* Initialize the base structure. */
112	/* What type of endpoint are we?  */
113	ep->base.type = SCTP_EP_TYPE_SOCKET;
114
115	/* Initialize the basic object fields. */
116	atomic_set(&ep->base.refcnt, 1);
117	ep->base.dead = false;
 
118
119	/* Create an input queue.  */
120	sctp_inq_init(&ep->base.inqueue);
121
122	/* Set its top-half handler */
123	sctp_inq_set_th_handler(&ep->base.inqueue, sctp_endpoint_bh_rcv);
124
125	/* Initialize the bind addr area */
126	sctp_bind_addr_init(&ep->base.bind_addr, 0);
127
128	/* Remember who we are attached to.  */
129	ep->base.sk = sk;
130	sock_hold(ep->base.sk);
131
132	/* Create the lists of associations.  */
133	INIT_LIST_HEAD(&ep->asocs);
134
135	/* Use SCTP specific send buffer space queues.  */
136	ep->sndbuf_policy = net->sctp.sndbuf_policy;
137
138	sk->sk_data_ready = sctp_data_ready;
139	sk->sk_write_space = sctp_write_space;
140	sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
141
142	/* Get the receive buffer policy for this endpoint */
143	ep->rcvbuf_policy = net->sctp.rcvbuf_policy;
144
145	/* Initialize the secret key used with cookie. */
146	get_random_bytes(ep->secret_key, sizeof(ep->secret_key));
 
 
147
148	/* SCTP-AUTH extensions*/
149	INIT_LIST_HEAD(&ep->endpoint_shared_keys);
150	null_key = sctp_auth_shkey_create(0, gfp);
151	if (!null_key)
152		goto nomem;
153
154	list_add(&null_key->key_list, &ep->endpoint_shared_keys);
155
156	/* Allocate and initialize transorms arrays for supported HMACs. */
157	err = sctp_auth_init_hmacs(ep, gfp);
158	if (err)
159		goto nomem_hmacs;
160
161	/* Add the null key to the endpoint shared keys list and
162	 * set the hmcas and chunks pointers.
163	 */
164	ep->auth_hmacs_list = auth_hmacs;
165	ep->auth_chunk_list = auth_chunks;
166
167	return ep;
168
169nomem_hmacs:
170	sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
171nomem:
172	/* Free all allocations */
173	kfree(auth_hmacs);
174	kfree(auth_chunks);
175	kfree(ep->digest);
176	return NULL;
177
178}
179
180/* Create a sctp_endpoint with all that boring stuff initialized.
181 * Returns NULL if there isn't enough memory.
182 */
183struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, gfp_t gfp)
184{
185	struct sctp_endpoint *ep;
186
187	/* Build a local endpoint. */
188	ep = kzalloc(sizeof(*ep), gfp);
189	if (!ep)
190		goto fail;
191
192	if (!sctp_endpoint_init(ep, sk, gfp))
193		goto fail_init;
194
195	SCTP_DBG_OBJCNT_INC(ep);
196	return ep;
197
198fail_init:
199	kfree(ep);
200fail:
201	return NULL;
202}
203
204/* Add an association to an endpoint.  */
205void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
206			    struct sctp_association *asoc)
207{
208	struct sock *sk = ep->base.sk;
209
210	/* If this is a temporary association, don't bother
211	 * since we'll be removing it shortly and don't
212	 * want anyone to find it anyway.
213	 */
214	if (asoc->temp)
215		return;
216
217	/* Now just add it to our list of asocs */
218	list_add_tail(&asoc->asocs, &ep->asocs);
219
220	/* Increment the backlog value for a TCP-style listening socket. */
221	if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
222		sk->sk_ack_backlog++;
223}
224
225/* Free the endpoint structure.  Delay cleanup until
226 * all users have released their reference count on this structure.
227 */
228void sctp_endpoint_free(struct sctp_endpoint *ep)
229{
230	ep->base.dead = true;
231
232	ep->base.sk->sk_state = SCTP_SS_CLOSED;
233
234	/* Unlink this endpoint, so we can't find it again! */
235	sctp_unhash_endpoint(ep);
236
237	sctp_endpoint_put(ep);
238}
239
240/* Final destructor for endpoint.  */
241static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
242{
243	struct sock *sk;
244
245	if (unlikely(!ep->base.dead)) {
246		WARN(1, "Attempt to destroy undead endpoint %p!\n", ep);
247		return;
248	}
249
250	/* Free the digest buffer */
251	kfree(ep->digest);
252
253	/* SCTP-AUTH: Free up AUTH releated data such as shared keys
254	 * chunks and hmacs arrays that were allocated
255	 */
256	sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
257	kfree(ep->auth_hmacs_list);
258	kfree(ep->auth_chunk_list);
259
260	/* AUTH - Free any allocated HMAC transform containers */
261	sctp_auth_destroy_hmacs(ep->auth_hmacs);
262
263	/* Cleanup. */
264	sctp_inq_free(&ep->base.inqueue);
265	sctp_bind_addr_free(&ep->base.bind_addr);
266
267	memset(ep->secret_key, 0, sizeof(ep->secret_key));
 
 
268
269	/* Give up our hold on the sock. */
270	sk = ep->base.sk;
271	if (sk != NULL) {
272		/* Remove and free the port */
273		if (sctp_sk(sk)->bind_hash)
274			sctp_put_port(sk);
275
276		sock_put(sk);
 
 
 
277	}
278
279	kfree(ep);
280	SCTP_DBG_OBJCNT_DEC(ep);
281}
282
283/* Hold a reference to an endpoint. */
284void sctp_endpoint_hold(struct sctp_endpoint *ep)
285{
286	atomic_inc(&ep->base.refcnt);
287}
288
289/* Release a reference to an endpoint and clean up if there are
290 * no more references.
291 */
292void sctp_endpoint_put(struct sctp_endpoint *ep)
293{
294	if (atomic_dec_and_test(&ep->base.refcnt))
295		sctp_endpoint_destroy(ep);
296}
297
298/* Is this the endpoint we are looking for?  */
299struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
300					       struct net *net,
301					       const union sctp_addr *laddr)
302{
303	struct sctp_endpoint *retval = NULL;
304
305	if ((htons(ep->base.bind_addr.port) == laddr->v4.sin_port) &&
306	    net_eq(sock_net(ep->base.sk), net)) {
307		if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
308					 sctp_sk(ep->base.sk)))
309			retval = ep;
310	}
311
312	return retval;
313}
314
315/* Find the association that goes with this chunk.
316 * We lookup the transport from hashtable at first, then get association
317 * through t->assoc.
318 */
319struct sctp_association *sctp_endpoint_lookup_assoc(
320	const struct sctp_endpoint *ep,
321	const union sctp_addr *paddr,
322	struct sctp_transport **transport)
323{
324	struct sctp_association *asoc = NULL;
325	struct sctp_transport *t;
 
 
 
 
 
 
326
327	*transport = NULL;
328
329	/* If the local port is not set, there can't be any associations
330	 * on this endpoint.
331	 */
332	if (!ep->base.bind_addr.port)
333		goto out;
334	t = sctp_epaddr_lookup_transport(ep, paddr);
335	if (!t)
336		goto out;
337
338	*transport = t;
339	asoc = t->asoc;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
340out:
341	return asoc;
342}
343
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
344/* Look for any peeled off association from the endpoint that matches the
345 * given peer address.
346 */
347int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
348				const union sctp_addr *paddr)
349{
350	struct sctp_sockaddr_entry *addr;
351	struct sctp_bind_addr *bp;
352	struct net *net = sock_net(ep->base.sk);
353
354	bp = &ep->base.bind_addr;
355	/* This function is called with the socket lock held,
356	 * so the address_list can not change.
357	 */
358	list_for_each_entry(addr, &bp->address_list, list) {
359		if (sctp_has_association(net, &addr->a, paddr))
360			return 1;
361	}
362
363	return 0;
364}
365
366/* Do delayed input processing.  This is scheduled by sctp_rcv().
367 * This may be called on BH or task time.
368 */
369static void sctp_endpoint_bh_rcv(struct work_struct *work)
370{
371	struct sctp_endpoint *ep =
372		container_of(work, struct sctp_endpoint,
373			     base.inqueue.immediate);
374	struct sctp_association *asoc;
375	struct sock *sk;
376	struct net *net;
377	struct sctp_transport *transport;
378	struct sctp_chunk *chunk;
379	struct sctp_inq *inqueue;
380	sctp_subtype_t subtype;
381	sctp_state_t state;
382	int error = 0;
383	int first_time = 1;	/* is this the first time through the loop */
384
385	if (ep->base.dead)
386		return;
387
388	asoc = NULL;
389	inqueue = &ep->base.inqueue;
390	sk = ep->base.sk;
391	net = sock_net(sk);
392
393	while (NULL != (chunk = sctp_inq_pop(inqueue))) {
394		subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
395
396		/* If the first chunk in the packet is AUTH, do special
397		 * processing specified in Section 6.3 of SCTP-AUTH spec
398		 */
399		if (first_time && (subtype.chunk == SCTP_CID_AUTH)) {
400			struct sctp_chunkhdr *next_hdr;
401
402			next_hdr = sctp_inq_peek(inqueue);
403			if (!next_hdr)
404				goto normal;
405
406			/* If the next chunk is COOKIE-ECHO, skip the AUTH
407			 * chunk while saving a pointer to it so we can do
408			 * Authentication later (during cookie-echo
409			 * processing).
410			 */
411			if (next_hdr->type == SCTP_CID_COOKIE_ECHO) {
412				chunk->auth_chunk = skb_clone(chunk->skb,
413								GFP_ATOMIC);
414				chunk->auth = 1;
415				continue;
416			}
417		}
418normal:
419		/* We might have grown an association since last we
420		 * looked, so try again.
421		 *
422		 * This happens when we've just processed our
423		 * COOKIE-ECHO chunk.
424		 */
425		if (NULL == chunk->asoc) {
426			asoc = sctp_endpoint_lookup_assoc(ep,
427							  sctp_source(chunk),
428							  &transport);
429			chunk->asoc = asoc;
430			chunk->transport = transport;
431		}
432
433		state = asoc ? asoc->state : SCTP_STATE_CLOSED;
434		if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
435			continue;
436
437		/* Remember where the last DATA chunk came from so we
438		 * know where to send the SACK.
439		 */
440		if (asoc && sctp_chunk_is_data(chunk))
441			asoc->peer.last_data_from = chunk->transport;
442		else {
443			SCTP_INC_STATS(sock_net(ep->base.sk), SCTP_MIB_INCTRLCHUNKS);
444			if (asoc)
445				asoc->stats.ictrlchunks++;
446		}
447
448		if (chunk->transport)
449			chunk->transport->last_time_heard = ktime_get();
450
451		error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype, state,
452				   ep, asoc, chunk, GFP_ATOMIC);
453
454		if (error && chunk)
455			chunk->pdiscard = 1;
456
457		/* Check to see if the endpoint is freed in response to
458		 * the incoming chunk. If so, get out of the while loop.
459		 */
460		if (!sctp_sk(sk)->ep)
461			break;
462
463		if (first_time)
464			first_time = 0;
465	}
466}