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 sctp_hmac_algo_param *auth_hmacs = NULL;
69 struct sctp_chunks_param *auth_chunks = NULL;
70 struct sctp_shared_key *null_key;
73 ep->digest = kzalloc(SCTP_SIGNATURE_SIZE, gfp);
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.
82 auth_hmacs = kzalloc(sizeof(sctp_hmac_algo_param_t) +
83 sizeof(__u16) * SCTP_AUTH_NUM_HMACS, gfp);
87 auth_chunks = kzalloc(sizeof(sctp_chunks_param_t) +
88 SCTP_NUM_CHUNK_TYPES, gfp);
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.
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);
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));
106 /* If the Add-IP functionality is enabled, we must
107 * authenticate, ASCONF and ASCONF-ACK chunks
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);
117 /* Initialize the base structure. */
118 /* What type of endpoint are we? */
119 ep->base.type = SCTP_EP_TYPE_SOCKET;
121 /* Initialize the basic object fields. */
122 atomic_set(&ep->base.refcnt, 1);
124 ep->base.malloced = 1;
126 /* Create an input queue. */
127 sctp_inq_init(&ep->base.inqueue);
129 /* Set its top-half handler */
130 sctp_inq_set_th_handler(&ep->base.inqueue, sctp_endpoint_bh_rcv);
132 /* Initialize the bind addr area */
133 sctp_bind_addr_init(&ep->base.bind_addr, 0);
135 /* Remember who we are attached to. */
137 sock_hold(ep->base.sk);
139 /* Create the lists of associations. */
140 INIT_LIST_HEAD(&ep->asocs);
142 /* Use SCTP specific send buffer space queues. */
143 ep->sndbuf_policy = sctp_sndbuf_policy;
145 sk->sk_write_space = sctp_write_space;
146 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
148 /* Get the receive buffer policy for this endpoint */
149 ep->rcvbuf_policy = sctp_rcvbuf_policy;
151 /* Initialize the secret key used with cookie. */
152 get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE);
153 ep->last_key = ep->current_key = 0;
154 ep->key_changed_at = jiffies;
156 /* SCTP-AUTH extensions*/
157 INIT_LIST_HEAD(&ep->endpoint_shared_keys);
158 null_key = sctp_auth_shkey_create(0, GFP_KERNEL);
162 list_add(&null_key->key_list, &ep->endpoint_shared_keys);
164 /* Allocate and initialize transorms arrays for suported 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))
201 ep->base.malloced = 1;
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)
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 /* Remove and free the port */
273 if (sctp_sk(ep->base.sk)->bind_hash)
274 sctp_put_port(ep->base.sk);
276 /* Give up our hold on the sock. */
278 sock_put(ep->base.sk);
280 /* Finally, free up our memory. */
281 if (ep->base.malloced) {
283 SCTP_DBG_OBJCNT_DEC(ep);
287 /* Hold a reference to an endpoint. */
288 void sctp_endpoint_hold(struct sctp_endpoint *ep)
290 atomic_inc(&ep->base.refcnt);
293 /* Release a reference to an endpoint and clean up if there are
294 * no more references.
296 void sctp_endpoint_put(struct sctp_endpoint *ep)
298 if (atomic_dec_and_test(&ep->base.refcnt))
299 sctp_endpoint_destroy(ep);
302 /* Is this the endpoint we are looking for? */
303 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 if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
310 sctp_sk(ep->base.sk)))
317 /* Find the association that goes with this chunk.
318 * We do a linear search of the associations for this endpoint.
319 * We return the matching transport address too.
321 static struct sctp_association *__sctp_endpoint_lookup_assoc(
322 const struct sctp_endpoint *ep,
323 const union sctp_addr *paddr,
324 struct sctp_transport **transport)
326 struct sctp_association *asoc = NULL;
327 struct sctp_transport *t = NULL;
328 struct sctp_hashbucket *head;
329 struct sctp_ep_common *epb;
330 struct hlist_node *node;
335 rport = ntohs(paddr->v4.sin_port);
337 hash = sctp_assoc_hashfn(ep->base.bind_addr.port, rport);
338 head = &sctp_assoc_hashtable[hash];
339 read_lock(&head->lock);
340 sctp_for_each_hentry(epb, node, &head->chain) {
341 asoc = sctp_assoc(epb);
342 if (asoc->ep != ep || rport != asoc->peer.port)
345 t = sctp_assoc_lookup_paddr(asoc, paddr);
353 read_unlock(&head->lock);
357 /* Lookup association on an endpoint based on a peer address. BH-safe. */
358 struct sctp_association *sctp_endpoint_lookup_assoc(
359 const struct sctp_endpoint *ep,
360 const union sctp_addr *paddr,
361 struct sctp_transport **transport)
363 struct sctp_association *asoc;
365 sctp_local_bh_disable();
366 asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport);
367 sctp_local_bh_enable();
372 /* Look for any peeled off association from the endpoint that matches the
373 * given peer address.
375 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
376 const union sctp_addr *paddr)
378 struct sctp_sockaddr_entry *addr;
379 struct sctp_bind_addr *bp;
381 bp = &ep->base.bind_addr;
382 /* This function is called with the socket lock held,
383 * so the address_list can not change.
385 list_for_each_entry(addr, &bp->address_list, list) {
386 if (sctp_has_association(&addr->a, paddr))
393 /* Do delayed input processing. This is scheduled by sctp_rcv().
394 * This may be called on BH or task time.
396 static void sctp_endpoint_bh_rcv(struct work_struct *work)
398 struct sctp_endpoint *ep =
399 container_of(work, struct sctp_endpoint,
400 base.inqueue.immediate);
401 struct sctp_association *asoc;
403 struct sctp_transport *transport;
404 struct sctp_chunk *chunk;
405 struct sctp_inq *inqueue;
406 sctp_subtype_t subtype;
409 int first_time = 1; /* is this the first time through the looop */
415 inqueue = &ep->base.inqueue;
418 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
419 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
421 /* If the first chunk in the packet is AUTH, do special
422 * processing specified in Section 6.3 of SCTP-AUTH spec
424 if (first_time && (subtype.chunk == SCTP_CID_AUTH)) {
425 struct sctp_chunkhdr *next_hdr;
427 next_hdr = sctp_inq_peek(inqueue);
431 /* If the next chunk is COOKIE-ECHO, skip the AUTH
432 * chunk while saving a pointer to it so we can do
433 * Authentication later (during cookie-echo
436 if (next_hdr->type == SCTP_CID_COOKIE_ECHO) {
437 chunk->auth_chunk = skb_clone(chunk->skb,
444 /* We might have grown an association since last we
445 * looked, so try again.
447 * This happens when we've just processed our
450 if (NULL == chunk->asoc) {
451 asoc = sctp_endpoint_lookup_assoc(ep,
455 chunk->transport = transport;
458 state = asoc ? asoc->state : SCTP_STATE_CLOSED;
459 if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
462 /* Remember where the last DATA chunk came from so we
463 * know where to send the SACK.
465 if (asoc && sctp_chunk_is_data(chunk))
466 asoc->peer.last_data_from = chunk->transport;
468 SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
470 if (chunk->transport)
471 chunk->transport->last_time_heard = jiffies;
473 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, state,
474 ep, asoc, chunk, GFP_ATOMIC);
479 /* Check to see if the endpoint is freed in response to
480 * the incoming chunk. If so, get out of the while loop.
482 if (!sctp_sk(sk)->ep)