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
9 * This file is part of the SCTP kernel implementation
11 * This abstraction represents an SCTP endpoint.
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)
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.
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.
30 * Please send any bug reports or fixes you make to the
32 * lksctp developers <lksctp-developers@lists.sourceforge.net>
34 * Or submit a bug report through the following website:
35 * http://www.sf.net/projects/lksctp
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>
44 * Any bugs reported given to us we will try to fix... any fixes shared will
45 * be incorporated into the next SCTP release.
48 #include <linux/types.h>
49 #include <linux/slab.h>
51 #include <linux/random.h> /* get_random_bytes() */
52 #include <linux/crypto.h>
55 #include <net/sctp/sctp.h>
56 #include <net/sctp/sm.h>
58 /* Forward declarations for internal helpers. */
59 static void sctp_endpoint_bh_rcv(struct work_struct *work);
62 * Initialize the base fields of the endpoint structure.
64 static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
68 struct net *net = sock_net(sk);
69 struct sctp_hmac_algo_param *auth_hmacs = NULL;
70 struct sctp_chunks_param *auth_chunks = NULL;
71 struct sctp_shared_key *null_key;
74 ep->digest = kzalloc(SCTP_SIGNATURE_SIZE, gfp);
78 if (net->sctp.auth_enable) {
79 /* Allocate space for HMACS and CHUNKS authentication
80 * variables. There are arrays that we encode directly
81 * into parameters to make the rest of the operations easier.
83 auth_hmacs = kzalloc(sizeof(sctp_hmac_algo_param_t) +
84 sizeof(__u16) * SCTP_AUTH_NUM_HMACS, gfp);
88 auth_chunks = kzalloc(sizeof(sctp_chunks_param_t) +
89 SCTP_NUM_CHUNK_TYPES, gfp);
93 /* Initialize the HMACS parameter.
94 * SCTP-AUTH: Section 3.3
95 * Every endpoint supporting SCTP chunk authentication MUST
96 * support the HMAC based on the SHA-1 algorithm.
98 auth_hmacs->param_hdr.type = SCTP_PARAM_HMAC_ALGO;
99 auth_hmacs->param_hdr.length =
100 htons(sizeof(sctp_paramhdr_t) + 2);
101 auth_hmacs->hmac_ids[0] = htons(SCTP_AUTH_HMAC_ID_SHA1);
103 /* Initialize the CHUNKS parameter */
104 auth_chunks->param_hdr.type = SCTP_PARAM_CHUNKS;
105 auth_chunks->param_hdr.length = htons(sizeof(sctp_paramhdr_t));
107 /* If the Add-IP functionality is enabled, we must
108 * authenticate, ASCONF and ASCONF-ACK chunks
110 if (net->sctp.addip_enable) {
111 auth_chunks->chunks[0] = SCTP_CID_ASCONF;
112 auth_chunks->chunks[1] = SCTP_CID_ASCONF_ACK;
113 auth_chunks->param_hdr.length =
114 htons(sizeof(sctp_paramhdr_t) + 2);
118 /* Initialize the base structure. */
119 /* What type of endpoint are we? */
120 ep->base.type = SCTP_EP_TYPE_SOCKET;
122 /* Initialize the basic object fields. */
123 atomic_set(&ep->base.refcnt, 1);
125 ep->base.malloced = 1;
127 /* Create an input queue. */
128 sctp_inq_init(&ep->base.inqueue);
130 /* Set its top-half handler */
131 sctp_inq_set_th_handler(&ep->base.inqueue, sctp_endpoint_bh_rcv);
133 /* Initialize the bind addr area */
134 sctp_bind_addr_init(&ep->base.bind_addr, 0);
136 /* Remember who we are attached to. */
138 sock_hold(ep->base.sk);
140 /* Create the lists of associations. */
141 INIT_LIST_HEAD(&ep->asocs);
143 /* Use SCTP specific send buffer space queues. */
144 ep->sndbuf_policy = net->sctp.sndbuf_policy;
146 sk->sk_data_ready = sctp_data_ready;
147 sk->sk_write_space = sctp_write_space;
148 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
150 /* Get the receive buffer policy for this endpoint */
151 ep->rcvbuf_policy = net->sctp.rcvbuf_policy;
153 /* Initialize the secret key used with cookie. */
154 get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE);
155 ep->last_key = ep->current_key = 0;
156 ep->key_changed_at = jiffies;
158 /* SCTP-AUTH extensions*/
159 INIT_LIST_HEAD(&ep->endpoint_shared_keys);
160 null_key = sctp_auth_shkey_create(0, GFP_KERNEL);
164 list_add(&null_key->key_list, &ep->endpoint_shared_keys);
166 /* Allocate and initialize transorms arrays for supported HMACs. */
167 err = sctp_auth_init_hmacs(ep, gfp);
171 /* Add the null key to the endpoint shared keys list and
172 * set the hmcas and chunks pointers.
174 ep->auth_hmacs_list = auth_hmacs;
175 ep->auth_chunk_list = auth_chunks;
180 sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
182 /* Free all allocations */
190 /* Create a sctp_endpoint with all that boring stuff initialized.
191 * Returns NULL if there isn't enough memory.
193 struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, gfp_t gfp)
195 struct sctp_endpoint *ep;
197 /* Build a local endpoint. */
198 ep = t_new(struct sctp_endpoint, gfp);
201 if (!sctp_endpoint_init(ep, sk, gfp))
203 ep->base.malloced = 1;
204 SCTP_DBG_OBJCNT_INC(ep);
213 /* Add an association to an endpoint. */
214 void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
215 struct sctp_association *asoc)
217 struct sock *sk = ep->base.sk;
219 /* If this is a temporary association, don't bother
220 * since we'll be removing it shortly and don't
221 * want anyone to find it anyway.
226 /* Now just add it to our list of asocs */
227 list_add_tail(&asoc->asocs, &ep->asocs);
229 /* Increment the backlog value for a TCP-style listening socket. */
230 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
231 sk->sk_ack_backlog++;
234 /* Free the endpoint structure. Delay cleanup until
235 * all users have released their reference count on this structure.
237 void sctp_endpoint_free(struct sctp_endpoint *ep)
241 ep->base.sk->sk_state = SCTP_SS_CLOSED;
243 /* Unlink this endpoint, so we can't find it again! */
244 sctp_unhash_endpoint(ep);
246 sctp_endpoint_put(ep);
249 /* Final destructor for endpoint. */
250 static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
254 SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return);
256 /* Free up the HMAC transform. */
257 crypto_free_hash(sctp_sk(ep->base.sk)->hmac);
259 /* Free the digest buffer */
262 /* SCTP-AUTH: Free up AUTH releated data such as shared keys
263 * chunks and hmacs arrays that were allocated
265 sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
266 kfree(ep->auth_hmacs_list);
267 kfree(ep->auth_chunk_list);
269 /* AUTH - Free any allocated HMAC transform containers */
270 sctp_auth_destroy_hmacs(ep->auth_hmacs);
273 sctp_inq_free(&ep->base.inqueue);
274 sctp_bind_addr_free(&ep->base.bind_addr);
276 for (i = 0; i < SCTP_HOW_MANY_SECRETS; ++i)
277 memset(&ep->secret_key[i], 0, SCTP_SECRET_SIZE);
279 /* Remove and free the port */
280 if (sctp_sk(ep->base.sk)->bind_hash)
281 sctp_put_port(ep->base.sk);
283 /* Give up our hold on the sock. */
285 sock_put(ep->base.sk);
287 /* Finally, free up our memory. */
288 if (ep->base.malloced) {
290 SCTP_DBG_OBJCNT_DEC(ep);
294 /* Hold a reference to an endpoint. */
295 void sctp_endpoint_hold(struct sctp_endpoint *ep)
297 atomic_inc(&ep->base.refcnt);
300 /* Release a reference to an endpoint and clean up if there are
301 * no more references.
303 void sctp_endpoint_put(struct sctp_endpoint *ep)
305 if (atomic_dec_and_test(&ep->base.refcnt))
306 sctp_endpoint_destroy(ep);
309 /* Is this the endpoint we are looking for? */
310 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
312 const union sctp_addr *laddr)
314 struct sctp_endpoint *retval = NULL;
316 if ((htons(ep->base.bind_addr.port) == laddr->v4.sin_port) &&
317 net_eq(sock_net(ep->base.sk), net)) {
318 if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
319 sctp_sk(ep->base.sk)))
326 /* Find the association that goes with this chunk.
327 * We do a linear search of the associations for this endpoint.
328 * We return the matching transport address too.
330 static struct sctp_association *__sctp_endpoint_lookup_assoc(
331 const struct sctp_endpoint *ep,
332 const union sctp_addr *paddr,
333 struct sctp_transport **transport)
335 struct sctp_association *asoc = NULL;
336 struct sctp_association *tmp;
337 struct sctp_transport *t = NULL;
338 struct sctp_hashbucket *head;
339 struct sctp_ep_common *epb;
340 struct hlist_node *node;
346 /* If the local port is not set, there can't be any associations
349 if (!ep->base.bind_addr.port)
352 rport = ntohs(paddr->v4.sin_port);
354 hash = sctp_assoc_hashfn(sock_net(ep->base.sk), ep->base.bind_addr.port,
356 head = &sctp_assoc_hashtable[hash];
357 read_lock(&head->lock);
358 sctp_for_each_hentry(epb, node, &head->chain) {
359 tmp = sctp_assoc(epb);
360 if (tmp->ep != ep || rport != tmp->peer.port)
363 t = sctp_assoc_lookup_paddr(tmp, paddr);
370 read_unlock(&head->lock);
375 /* Lookup association on an endpoint based on a peer address. BH-safe. */
376 struct sctp_association *sctp_endpoint_lookup_assoc(
377 const struct sctp_endpoint *ep,
378 const union sctp_addr *paddr,
379 struct sctp_transport **transport)
381 struct sctp_association *asoc;
383 sctp_local_bh_disable();
384 asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport);
385 sctp_local_bh_enable();
390 /* Look for any peeled off association from the endpoint that matches the
391 * given peer address.
393 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
394 const union sctp_addr *paddr)
396 struct sctp_sockaddr_entry *addr;
397 struct sctp_bind_addr *bp;
398 struct net *net = sock_net(ep->base.sk);
400 bp = &ep->base.bind_addr;
401 /* This function is called with the socket lock held,
402 * so the address_list can not change.
404 list_for_each_entry(addr, &bp->address_list, list) {
405 if (sctp_has_association(net, &addr->a, paddr))
412 /* Do delayed input processing. This is scheduled by sctp_rcv().
413 * This may be called on BH or task time.
415 static void sctp_endpoint_bh_rcv(struct work_struct *work)
417 struct sctp_endpoint *ep =
418 container_of(work, struct sctp_endpoint,
419 base.inqueue.immediate);
420 struct sctp_association *asoc;
423 struct sctp_transport *transport;
424 struct sctp_chunk *chunk;
425 struct sctp_inq *inqueue;
426 sctp_subtype_t subtype;
429 int first_time = 1; /* is this the first time through the loop */
435 inqueue = &ep->base.inqueue;
439 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
440 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
442 /* If the first chunk in the packet is AUTH, do special
443 * processing specified in Section 6.3 of SCTP-AUTH spec
445 if (first_time && (subtype.chunk == SCTP_CID_AUTH)) {
446 struct sctp_chunkhdr *next_hdr;
448 next_hdr = sctp_inq_peek(inqueue);
452 /* If the next chunk is COOKIE-ECHO, skip the AUTH
453 * chunk while saving a pointer to it so we can do
454 * Authentication later (during cookie-echo
457 if (next_hdr->type == SCTP_CID_COOKIE_ECHO) {
458 chunk->auth_chunk = skb_clone(chunk->skb,
465 /* We might have grown an association since last we
466 * looked, so try again.
468 * This happens when we've just processed our
471 if (NULL == chunk->asoc) {
472 asoc = sctp_endpoint_lookup_assoc(ep,
476 chunk->transport = transport;
479 state = asoc ? asoc->state : SCTP_STATE_CLOSED;
480 if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
483 /* Remember where the last DATA chunk came from so we
484 * know where to send the SACK.
486 if (asoc && sctp_chunk_is_data(chunk))
487 asoc->peer.last_data_from = chunk->transport;
489 SCTP_INC_STATS(sock_net(ep->base.sk), SCTP_MIB_INCTRLCHUNKS);
491 asoc->stats.ictrlchunks++;
494 if (chunk->transport)
495 chunk->transport->last_time_heard = jiffies;
497 error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype, state,
498 ep, asoc, chunk, GFP_ATOMIC);
503 /* Check to see if the endpoint is freed in response to
504 * the incoming chunk. If so, get out of the while loop.
506 if (!sctp_sk(sk)->ep)