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, see
27 * <http://www.gnu.org/licenses/>.
29 * Please send any bug reports or fixes you make to the
31 * lksctp developers <linux-sctp@vger.kernel.org>
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>
41 #include <linux/types.h>
42 #include <linux/slab.h>
44 #include <linux/random.h> /* get_random_bytes() */
45 #include <linux/crypto.h>
48 #include <net/sctp/sctp.h>
49 #include <net/sctp/sm.h>
51 /* Forward declarations for internal helpers. */
52 static void sctp_endpoint_bh_rcv(struct work_struct *work);
55 * Initialize the base fields of the endpoint structure.
57 static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
61 struct net *net = sock_net(sk);
62 struct sctp_hmac_algo_param *auth_hmacs = NULL;
63 struct sctp_chunks_param *auth_chunks = NULL;
64 struct sctp_shared_key *null_key;
67 ep->digest = kzalloc(SCTP_SIGNATURE_SIZE, gfp);
71 ep->auth_enable = net->sctp.auth_enable;
72 if (ep->auth_enable) {
73 /* Allocate space for HMACS and CHUNKS authentication
74 * variables. There are arrays that we encode directly
75 * into parameters to make the rest of the operations easier.
77 auth_hmacs = kzalloc(sizeof(sctp_hmac_algo_param_t) +
78 sizeof(__u16) * SCTP_AUTH_NUM_HMACS, gfp);
82 auth_chunks = kzalloc(sizeof(sctp_chunks_param_t) +
83 SCTP_NUM_CHUNK_TYPES, gfp);
87 /* Initialize the HMACS parameter.
88 * SCTP-AUTH: Section 3.3
89 * Every endpoint supporting SCTP chunk authentication MUST
90 * support the HMAC based on the SHA-1 algorithm.
92 auth_hmacs->param_hdr.type = SCTP_PARAM_HMAC_ALGO;
93 auth_hmacs->param_hdr.length =
94 htons(sizeof(sctp_paramhdr_t) + 2);
95 auth_hmacs->hmac_ids[0] = htons(SCTP_AUTH_HMAC_ID_SHA1);
97 /* Initialize the CHUNKS parameter */
98 auth_chunks->param_hdr.type = SCTP_PARAM_CHUNKS;
99 auth_chunks->param_hdr.length = htons(sizeof(sctp_paramhdr_t));
101 /* If the Add-IP functionality is enabled, we must
102 * authenticate, ASCONF and ASCONF-ACK chunks
104 if (net->sctp.addip_enable) {
105 auth_chunks->chunks[0] = SCTP_CID_ASCONF;
106 auth_chunks->chunks[1] = SCTP_CID_ASCONF_ACK;
107 auth_chunks->param_hdr.length =
108 htons(sizeof(sctp_paramhdr_t) + 2);
112 /* Initialize the base structure. */
113 /* What type of endpoint are we? */
114 ep->base.type = SCTP_EP_TYPE_SOCKET;
116 /* Initialize the basic object fields. */
117 atomic_set(&ep->base.refcnt, 1);
118 ep->base.dead = false;
120 /* Create an input queue. */
121 sctp_inq_init(&ep->base.inqueue);
123 /* Set its top-half handler */
124 sctp_inq_set_th_handler(&ep->base.inqueue, sctp_endpoint_bh_rcv);
126 /* Initialize the bind addr area */
127 sctp_bind_addr_init(&ep->base.bind_addr, 0);
129 /* Remember who we are attached to. */
131 sock_hold(ep->base.sk);
133 /* Create the lists of associations. */
134 INIT_LIST_HEAD(&ep->asocs);
136 /* Use SCTP specific send buffer space queues. */
137 ep->sndbuf_policy = net->sctp.sndbuf_policy;
139 sk->sk_data_ready = sctp_data_ready;
140 sk->sk_write_space = sctp_write_space;
141 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
143 /* Get the receive buffer policy for this endpoint */
144 ep->rcvbuf_policy = net->sctp.rcvbuf_policy;
146 /* Initialize the secret key used with cookie. */
147 get_random_bytes(ep->secret_key, sizeof(ep->secret_key));
149 /* SCTP-AUTH extensions*/
150 INIT_LIST_HEAD(&ep->endpoint_shared_keys);
151 null_key = sctp_auth_shkey_create(0, gfp);
155 list_add(&null_key->key_list, &ep->endpoint_shared_keys);
157 /* Allocate and initialize transorms arrays for supported HMACs. */
158 err = sctp_auth_init_hmacs(ep, gfp);
162 /* Add the null key to the endpoint shared keys list and
163 * set the hmcas and chunks pointers.
165 ep->auth_hmacs_list = auth_hmacs;
166 ep->auth_chunk_list = auth_chunks;
171 sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
173 /* Free all allocations */
181 /* Create a sctp_endpoint with all that boring stuff initialized.
182 * Returns NULL if there isn't enough memory.
184 struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, gfp_t gfp)
186 struct sctp_endpoint *ep;
188 /* Build a local endpoint. */
189 ep = kzalloc(sizeof(*ep), gfp);
193 if (!sctp_endpoint_init(ep, sk, gfp))
196 SCTP_DBG_OBJCNT_INC(ep);
205 /* Add an association to an endpoint. */
206 void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
207 struct sctp_association *asoc)
209 struct sock *sk = ep->base.sk;
211 /* If this is a temporary association, don't bother
212 * since we'll be removing it shortly and don't
213 * want anyone to find it anyway.
218 /* Now just add it to our list of asocs */
219 list_add_tail(&asoc->asocs, &ep->asocs);
221 /* Increment the backlog value for a TCP-style listening socket. */
222 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
223 sk->sk_ack_backlog++;
226 /* Free the endpoint structure. Delay cleanup until
227 * all users have released their reference count on this structure.
229 void sctp_endpoint_free(struct sctp_endpoint *ep)
231 ep->base.dead = true;
233 ep->base.sk->sk_state = SCTP_SS_CLOSED;
235 /* Unlink this endpoint, so we can't find it again! */
236 sctp_unhash_endpoint(ep);
238 sctp_endpoint_put(ep);
241 /* Final destructor for endpoint. */
242 static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
246 if (unlikely(!ep->base.dead)) {
247 WARN(1, "Attempt to destroy undead endpoint %p!\n", ep);
251 /* Free the digest buffer */
254 /* SCTP-AUTH: Free up AUTH releated data such as shared keys
255 * chunks and hmacs arrays that were allocated
257 sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
258 kfree(ep->auth_hmacs_list);
259 kfree(ep->auth_chunk_list);
261 /* AUTH - Free any allocated HMAC transform containers */
262 sctp_auth_destroy_hmacs(ep->auth_hmacs);
265 sctp_inq_free(&ep->base.inqueue);
266 sctp_bind_addr_free(&ep->base.bind_addr);
268 memset(ep->secret_key, 0, sizeof(ep->secret_key));
270 /* Give up our hold on the sock. */
273 /* Remove and free the port */
274 if (sctp_sk(sk)->bind_hash)
281 SCTP_DBG_OBJCNT_DEC(ep);
284 /* Hold a reference to an endpoint. */
285 void sctp_endpoint_hold(struct sctp_endpoint *ep)
287 atomic_inc(&ep->base.refcnt);
290 /* Release a reference to an endpoint and clean up if there are
291 * no more references.
293 void sctp_endpoint_put(struct sctp_endpoint *ep)
295 if (atomic_dec_and_test(&ep->base.refcnt))
296 sctp_endpoint_destroy(ep);
299 /* Is this the endpoint we are looking for? */
300 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
302 const union sctp_addr *laddr)
304 struct sctp_endpoint *retval = NULL;
306 if ((htons(ep->base.bind_addr.port) == laddr->v4.sin_port) &&
307 net_eq(sock_net(ep->base.sk), net)) {
308 if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
309 sctp_sk(ep->base.sk)))
316 /* Find the association that goes with this chunk.
317 * We lookup the transport from hashtable at first, then get association
320 struct sctp_association *sctp_endpoint_lookup_assoc(
321 const struct sctp_endpoint *ep,
322 const union sctp_addr *paddr,
323 struct sctp_transport **transport)
325 struct sctp_association *asoc = NULL;
326 struct sctp_transport *t;
330 /* If the local port is not set, there can't be any associations
333 if (!ep->base.bind_addr.port)
335 t = sctp_epaddr_lookup_transport(ep, paddr);
336 if (!t || t->asoc->temp)
345 /* Look for any peeled off association from the endpoint that matches the
346 * given peer address.
348 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
349 const union sctp_addr *paddr)
351 struct sctp_sockaddr_entry *addr;
352 struct sctp_bind_addr *bp;
353 struct net *net = sock_net(ep->base.sk);
355 bp = &ep->base.bind_addr;
356 /* This function is called with the socket lock held,
357 * so the address_list can not change.
359 list_for_each_entry(addr, &bp->address_list, list) {
360 if (sctp_has_association(net, &addr->a, paddr))
367 /* Do delayed input processing. This is scheduled by sctp_rcv().
368 * This may be called on BH or task time.
370 static void sctp_endpoint_bh_rcv(struct work_struct *work)
372 struct sctp_endpoint *ep =
373 container_of(work, struct sctp_endpoint,
374 base.inqueue.immediate);
375 struct sctp_association *asoc;
378 struct sctp_transport *transport;
379 struct sctp_chunk *chunk;
380 struct sctp_inq *inqueue;
381 sctp_subtype_t subtype;
384 int first_time = 1; /* is this the first time through the loop */
390 inqueue = &ep->base.inqueue;
394 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
395 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
397 /* If the first chunk in the packet is AUTH, do special
398 * processing specified in Section 6.3 of SCTP-AUTH spec
400 if (first_time && (subtype.chunk == SCTP_CID_AUTH)) {
401 struct sctp_chunkhdr *next_hdr;
403 next_hdr = sctp_inq_peek(inqueue);
407 /* If the next chunk is COOKIE-ECHO, skip the AUTH
408 * chunk while saving a pointer to it so we can do
409 * Authentication later (during cookie-echo
412 if (next_hdr->type == SCTP_CID_COOKIE_ECHO) {
413 chunk->auth_chunk = skb_clone(chunk->skb,
420 /* We might have grown an association since last we
421 * looked, so try again.
423 * This happens when we've just processed our
426 if (NULL == chunk->asoc) {
427 asoc = sctp_endpoint_lookup_assoc(ep,
431 chunk->transport = transport;
434 state = asoc ? asoc->state : SCTP_STATE_CLOSED;
435 if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
438 /* Remember where the last DATA chunk came from so we
439 * know where to send the SACK.
441 if (asoc && sctp_chunk_is_data(chunk))
442 asoc->peer.last_data_from = chunk->transport;
444 SCTP_INC_STATS(sock_net(ep->base.sk), SCTP_MIB_INCTRLCHUNKS);
446 asoc->stats.ictrlchunks++;
449 if (chunk->transport)
450 chunk->transport->last_time_heard = ktime_get();
452 error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype, state,
453 ep, asoc, chunk, GFP_ATOMIC);
458 /* Check to see if the endpoint is freed in response to
459 * the incoming chunk. If so, get out of the while loop.
461 if (!sctp_sk(sk)->ep)