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 ep->auth_enable = net->sctp.auth_enable;
79 if (ep->auth_enable) {
80 /* Allocate space for HMACS and CHUNKS authentication
81 * variables. There are arrays that we encode directly
82 * into parameters to make the rest of the operations easier.
84 auth_hmacs = kzalloc(sizeof(sctp_hmac_algo_param_t) +
85 sizeof(__u16) * SCTP_AUTH_NUM_HMACS, gfp);
89 auth_chunks = kzalloc(sizeof(sctp_chunks_param_t) +
90 SCTP_NUM_CHUNK_TYPES, gfp);
94 /* Initialize the HMACS parameter.
95 * SCTP-AUTH: Section 3.3
96 * Every endpoint supporting SCTP chunk authentication MUST
97 * support the HMAC based on the SHA-1 algorithm.
99 auth_hmacs->param_hdr.type = SCTP_PARAM_HMAC_ALGO;
100 auth_hmacs->param_hdr.length =
101 htons(sizeof(sctp_paramhdr_t) + 2);
102 auth_hmacs->hmac_ids[0] = htons(SCTP_AUTH_HMAC_ID_SHA1);
104 /* Initialize the CHUNKS parameter */
105 auth_chunks->param_hdr.type = SCTP_PARAM_CHUNKS;
106 auth_chunks->param_hdr.length = htons(sizeof(sctp_paramhdr_t));
108 /* If the Add-IP functionality is enabled, we must
109 * authenticate, ASCONF and ASCONF-ACK chunks
111 if (net->sctp.addip_enable) {
112 auth_chunks->chunks[0] = SCTP_CID_ASCONF;
113 auth_chunks->chunks[1] = SCTP_CID_ASCONF_ACK;
114 auth_chunks->param_hdr.length =
115 htons(sizeof(sctp_paramhdr_t) + 2);
119 /* Initialize the base structure. */
120 /* What type of endpoint are we? */
121 ep->base.type = SCTP_EP_TYPE_SOCKET;
123 /* Initialize the basic object fields. */
124 atomic_set(&ep->base.refcnt, 1);
125 ep->base.dead = false;
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, sizeof(ep->secret_key));
156 /* SCTP-AUTH extensions*/
157 INIT_LIST_HEAD(&ep->endpoint_shared_keys);
158 null_key = sctp_auth_shkey_create(0, gfp);
162 list_add(&null_key->key_list, &ep->endpoint_shared_keys);
164 /* Allocate and initialize transorms arrays for supported HMACs. */
165 err = sctp_auth_init_hmacs(ep, gfp);
169 /* Add the null key to the endpoint shared keys list and
170 * set the hmcas and chunks pointers.
172 ep->auth_hmacs_list = auth_hmacs;
173 ep->auth_chunk_list = auth_chunks;
178 sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
180 /* Free all allocations */
188 /* Create a sctp_endpoint with all that boring stuff initialized.
189 * Returns NULL if there isn't enough memory.
191 struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, gfp_t gfp)
193 struct sctp_endpoint *ep;
195 /* Build a local endpoint. */
196 ep = t_new(struct sctp_endpoint, gfp);
199 if (!sctp_endpoint_init(ep, sk, gfp))
202 SCTP_DBG_OBJCNT_INC(ep);
211 /* Add an association to an endpoint. */
212 void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
213 struct sctp_association *asoc)
215 struct sock *sk = ep->base.sk;
217 /* If this is a temporary association, don't bother
218 * since we'll be removing it shortly and don't
219 * want anyone to find it anyway.
224 /* Now just add it to our list of asocs */
225 list_add_tail(&asoc->asocs, &ep->asocs);
227 /* Increment the backlog value for a TCP-style listening socket. */
228 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
229 sk->sk_ack_backlog++;
232 /* Free the endpoint structure. Delay cleanup until
233 * all users have released their reference count on this structure.
235 void sctp_endpoint_free(struct sctp_endpoint *ep)
237 ep->base.dead = true;
239 ep->base.sk->sk_state = SCTP_SS_CLOSED;
241 /* Unlink this endpoint, so we can't find it again! */
242 sctp_unhash_endpoint(ep);
244 sctp_endpoint_put(ep);
247 /* Final destructor for endpoint. */
248 static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
250 SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return);
252 /* Free up the HMAC transform. */
253 crypto_free_hash(sctp_sk(ep->base.sk)->hmac);
255 /* Free the digest buffer */
258 /* SCTP-AUTH: Free up AUTH releated data such as shared keys
259 * chunks and hmacs arrays that were allocated
261 sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
262 kfree(ep->auth_hmacs_list);
263 kfree(ep->auth_chunk_list);
265 /* AUTH - Free any allocated HMAC transform containers */
266 sctp_auth_destroy_hmacs(ep->auth_hmacs);
269 sctp_inq_free(&ep->base.inqueue);
270 sctp_bind_addr_free(&ep->base.bind_addr);
272 memset(ep->secret_key, 0, sizeof(ep->secret_key));
274 /* Remove and free the port */
275 if (sctp_sk(ep->base.sk)->bind_hash)
276 sctp_put_port(ep->base.sk);
278 /* Give up our hold on the sock. */
280 sock_put(ep->base.sk);
283 SCTP_DBG_OBJCNT_DEC(ep);
286 /* Hold a reference to an endpoint. */
287 void sctp_endpoint_hold(struct sctp_endpoint *ep)
289 atomic_inc(&ep->base.refcnt);
292 /* Release a reference to an endpoint and clean up if there are
293 * no more references.
295 void sctp_endpoint_put(struct sctp_endpoint *ep)
297 if (atomic_dec_and_test(&ep->base.refcnt))
298 sctp_endpoint_destroy(ep);
301 /* Is this the endpoint we are looking for? */
302 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
304 const union sctp_addr *laddr)
306 struct sctp_endpoint *retval = NULL;
308 if ((htons(ep->base.bind_addr.port) == laddr->v4.sin_port) &&
309 net_eq(sock_net(ep->base.sk), net)) {
310 if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
311 sctp_sk(ep->base.sk)))
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.
322 static struct sctp_association *__sctp_endpoint_lookup_assoc(
323 const struct sctp_endpoint *ep,
324 const union sctp_addr *paddr,
325 struct sctp_transport **transport)
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;
337 /* If the local port is not set, there can't be any associations
340 if (!ep->base.bind_addr.port)
343 rport = ntohs(paddr->v4.sin_port);
345 hash = sctp_assoc_hashfn(sock_net(ep->base.sk), ep->base.bind_addr.port,
347 head = &sctp_assoc_hashtable[hash];
348 read_lock(&head->lock);
349 sctp_for_each_hentry(epb, &head->chain) {
350 tmp = sctp_assoc(epb);
351 if (tmp->ep != ep || rport != tmp->peer.port)
354 t = sctp_assoc_lookup_paddr(tmp, paddr);
361 read_unlock(&head->lock);
366 /* Lookup association on an endpoint based on a peer address. BH-safe. */
367 struct sctp_association *sctp_endpoint_lookup_assoc(
368 const struct sctp_endpoint *ep,
369 const union sctp_addr *paddr,
370 struct sctp_transport **transport)
372 struct sctp_association *asoc;
374 sctp_local_bh_disable();
375 asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport);
376 sctp_local_bh_enable();
381 /* Look for any peeled off association from the endpoint that matches the
382 * given peer address.
384 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
385 const union sctp_addr *paddr)
387 struct sctp_sockaddr_entry *addr;
388 struct sctp_bind_addr *bp;
389 struct net *net = sock_net(ep->base.sk);
391 bp = &ep->base.bind_addr;
392 /* This function is called with the socket lock held,
393 * so the address_list can not change.
395 list_for_each_entry(addr, &bp->address_list, list) {
396 if (sctp_has_association(net, &addr->a, paddr))
403 /* Do delayed input processing. This is scheduled by sctp_rcv().
404 * This may be called on BH or task time.
406 static void sctp_endpoint_bh_rcv(struct work_struct *work)
408 struct sctp_endpoint *ep =
409 container_of(work, struct sctp_endpoint,
410 base.inqueue.immediate);
411 struct sctp_association *asoc;
414 struct sctp_transport *transport;
415 struct sctp_chunk *chunk;
416 struct sctp_inq *inqueue;
417 sctp_subtype_t subtype;
420 int first_time = 1; /* is this the first time through the loop */
426 inqueue = &ep->base.inqueue;
430 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
431 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
433 /* If the first chunk in the packet is AUTH, do special
434 * processing specified in Section 6.3 of SCTP-AUTH spec
436 if (first_time && (subtype.chunk == SCTP_CID_AUTH)) {
437 struct sctp_chunkhdr *next_hdr;
439 next_hdr = sctp_inq_peek(inqueue);
443 /* If the next chunk is COOKIE-ECHO, skip the AUTH
444 * chunk while saving a pointer to it so we can do
445 * Authentication later (during cookie-echo
448 if (next_hdr->type == SCTP_CID_COOKIE_ECHO) {
449 chunk->auth_chunk = skb_clone(chunk->skb,
456 /* We might have grown an association since last we
457 * looked, so try again.
459 * This happens when we've just processed our
462 if (NULL == chunk->asoc) {
463 asoc = sctp_endpoint_lookup_assoc(ep,
467 chunk->transport = transport;
470 state = asoc ? asoc->state : SCTP_STATE_CLOSED;
471 if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
474 /* Remember where the last DATA chunk came from so we
475 * know where to send the SACK.
477 if (asoc && sctp_chunk_is_data(chunk))
478 asoc->peer.last_data_from = chunk->transport;
480 SCTP_INC_STATS(sock_net(ep->base.sk), SCTP_MIB_INCTRLCHUNKS);
482 asoc->stats.ictrlchunks++;
485 if (chunk->transport)
486 chunk->transport->last_time_heard = jiffies;
488 error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype, state,
489 ep, asoc, chunk, GFP_ATOMIC);
494 /* Check to see if the endpoint is freed in response to
495 * the incoming chunk. If so, get out of the while loop.
497 if (!sctp_sk(sk)->ep)