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8e8caf97 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
60c778b2 | 2 | /* SCTP kernel implementation |
1da177e4 LT |
3 | * Copyright (c) 1999-2000 Cisco, Inc. |
4 | * Copyright (c) 1999-2001 Motorola, Inc. | |
5 | * Copyright (c) 2001-2002 International Business Machines, Corp. | |
6 | * Copyright (c) 2001 Intel Corp. | |
7 | * Copyright (c) 2001 Nokia, Inc. | |
8 | * Copyright (c) 2001 La Monte H.P. Yarroll | |
9 | * | |
60c778b2 | 10 | * This file is part of the SCTP kernel implementation |
1da177e4 LT |
11 | * |
12 | * This abstraction represents an SCTP endpoint. | |
13 | * | |
1da177e4 LT |
14 | * Please send any bug reports or fixes you make to the |
15 | * email address(es): | |
91705c61 | 16 | * lksctp developers <linux-sctp@vger.kernel.org> |
1da177e4 | 17 | * |
1da177e4 LT |
18 | * Written or modified by: |
19 | * La Monte H.P. Yarroll <piggy@acm.org> | |
20 | * Karl Knutson <karl@athena.chicago.il.us> | |
21 | * Jon Grimm <jgrimm@austin.ibm.com> | |
22 | * Daisy Chang <daisyc@us.ibm.com> | |
23 | * Dajiang Zhang <dajiang.zhang@nokia.com> | |
1da177e4 LT |
24 | */ |
25 | ||
26 | #include <linux/types.h> | |
1da177e4 LT |
27 | #include <linux/slab.h> |
28 | #include <linux/in.h> | |
29 | #include <linux/random.h> /* get_random_bytes() */ | |
1da177e4 LT |
30 | #include <net/sock.h> |
31 | #include <net/ipv6.h> | |
32 | #include <net/sctp/sctp.h> | |
33 | #include <net/sctp/sm.h> | |
34 | ||
35 | /* Forward declarations for internal helpers. */ | |
c4028958 | 36 | static void sctp_endpoint_bh_rcv(struct work_struct *work); |
1da177e4 LT |
37 | |
38 | /* | |
39 | * Initialize the base fields of the endpoint structure. | |
40 | */ | |
41 | static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep, | |
3182cd84 | 42 | struct sock *sk, |
dd0fc66f | 43 | gfp_t gfp) |
1da177e4 | 44 | { |
e1fc3b14 | 45 | struct net *net = sock_net(sk); |
a29a5bd4 | 46 | struct sctp_shared_key *null_key; |
a29a5bd4 | 47 | |
b68dbcab VY |
48 | ep->digest = kzalloc(SCTP_SIGNATURE_SIZE, gfp); |
49 | if (!ep->digest) | |
50 | return NULL; | |
51 | ||
4e27428f | 52 | ep->asconf_enable = net->sctp.addip_enable; |
b14878cc VY |
53 | ep->auth_enable = net->sctp.auth_enable; |
54 | if (ep->auth_enable) { | |
03f96127 | 55 | if (sctp_auth_init(ep, gfp)) |
a29a5bd4 | 56 | goto nomem; |
4e27428f | 57 | if (ep->asconf_enable) { |
03f96127 XL |
58 | sctp_auth_ep_add_chunkid(ep, SCTP_CID_ASCONF); |
59 | sctp_auth_ep_add_chunkid(ep, SCTP_CID_ASCONF_ACK); | |
a29a5bd4 VY |
60 | } |
61 | } | |
62 | ||
1da177e4 LT |
63 | /* Initialize the base structure. */ |
64 | /* What type of endpoint are we? */ | |
65 | ep->base.type = SCTP_EP_TYPE_SOCKET; | |
66 | ||
67 | /* Initialize the basic object fields. */ | |
c638457a | 68 | refcount_set(&ep->base.refcnt, 1); |
0022d2dd | 69 | ep->base.dead = false; |
1da177e4 LT |
70 | |
71 | /* Create an input queue. */ | |
72 | sctp_inq_init(&ep->base.inqueue); | |
73 | ||
74 | /* Set its top-half handler */ | |
c4028958 | 75 | sctp_inq_set_th_handler(&ep->base.inqueue, sctp_endpoint_bh_rcv); |
1da177e4 LT |
76 | |
77 | /* Initialize the bind addr area */ | |
78 | sctp_bind_addr_init(&ep->base.bind_addr, 0); | |
1da177e4 | 79 | |
1da177e4 LT |
80 | /* Create the lists of associations. */ |
81 | INIT_LIST_HEAD(&ep->asocs); | |
82 | ||
1da177e4 | 83 | /* Use SCTP specific send buffer space queues. */ |
e1fc3b14 | 84 | ep->sndbuf_policy = net->sctp.sndbuf_policy; |
4d93df0a | 85 | |
561b1733 | 86 | sk->sk_data_ready = sctp_data_ready; |
1da177e4 LT |
87 | sk->sk_write_space = sctp_write_space; |
88 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); | |
89 | ||
049b3ff5 | 90 | /* Get the receive buffer policy for this endpoint */ |
e1fc3b14 | 91 | ep->rcvbuf_policy = net->sctp.rcvbuf_policy; |
049b3ff5 | 92 | |
1da177e4 | 93 | /* Initialize the secret key used with cookie. */ |
570617e7 | 94 | get_random_bytes(ep->secret_key, sizeof(ep->secret_key)); |
1da177e4 | 95 | |
a29a5bd4 VY |
96 | /* SCTP-AUTH extensions*/ |
97 | INIT_LIST_HEAD(&ep->endpoint_shared_keys); | |
81ce0dbc | 98 | null_key = sctp_auth_shkey_create(0, gfp); |
a29a5bd4 | 99 | if (!null_key) |
60208f79 | 100 | goto nomem_shkey; |
a29a5bd4 VY |
101 | |
102 | list_add(&null_key->key_list, &ep->endpoint_shared_keys); | |
103 | ||
a29a5bd4 VY |
104 | /* Add the null key to the endpoint shared keys list and |
105 | * set the hmcas and chunks pointers. | |
106 | */ | |
28aa4c26 | 107 | ep->prsctp_enable = net->sctp.prsctp_enable; |
c28445c3 | 108 | ep->reconf_enable = net->sctp.reconf_enable; |
1b0b8114 | 109 | ep->ecn_enable = net->sctp.ecn_enable; |
a29a5bd4 | 110 | |
25bff6d5 XL |
111 | /* Remember who we are attached to. */ |
112 | ep->base.sk = sk; | |
113 | sock_hold(ep->base.sk); | |
114 | ||
1da177e4 | 115 | return ep; |
a29a5bd4 | 116 | |
60208f79 | 117 | nomem_shkey: |
03f96127 | 118 | sctp_auth_free(ep); |
a29a5bd4 | 119 | nomem: |
a29a5bd4 VY |
120 | kfree(ep->digest); |
121 | return NULL; | |
122 | ||
1da177e4 LT |
123 | } |
124 | ||
125 | /* Create a sctp_endpoint with all that boring stuff initialized. | |
126 | * Returns NULL if there isn't enough memory. | |
127 | */ | |
dd0fc66f | 128 | struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, gfp_t gfp) |
1da177e4 LT |
129 | { |
130 | struct sctp_endpoint *ep; | |
131 | ||
132 | /* Build a local endpoint. */ | |
939cfa75 | 133 | ep = kzalloc(sizeof(*ep), gfp); |
1da177e4 LT |
134 | if (!ep) |
135 | goto fail; | |
939cfa75 | 136 | |
1da177e4 LT |
137 | if (!sctp_endpoint_init(ep, sk, gfp)) |
138 | goto fail_init; | |
ff2266cd | 139 | |
1da177e4 LT |
140 | SCTP_DBG_OBJCNT_INC(ep); |
141 | return ep; | |
142 | ||
143 | fail_init: | |
144 | kfree(ep); | |
145 | fail: | |
146 | return NULL; | |
147 | } | |
148 | ||
149 | /* Add an association to an endpoint. */ | |
150 | void sctp_endpoint_add_asoc(struct sctp_endpoint *ep, | |
151 | struct sctp_association *asoc) | |
152 | { | |
153 | struct sock *sk = ep->base.sk; | |
154 | ||
de76e695 VY |
155 | /* If this is a temporary association, don't bother |
156 | * since we'll be removing it shortly and don't | |
157 | * want anyone to find it anyway. | |
158 | */ | |
159 | if (asoc->temp) | |
160 | return; | |
161 | ||
1da177e4 LT |
162 | /* Now just add it to our list of asocs */ |
163 | list_add_tail(&asoc->asocs, &ep->asocs); | |
164 | ||
165 | /* Increment the backlog value for a TCP-style listening socket. */ | |
166 | if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) | |
167 | sk->sk_ack_backlog++; | |
168 | } | |
169 | ||
170 | /* Free the endpoint structure. Delay cleanup until | |
171 | * all users have released their reference count on this structure. | |
172 | */ | |
173 | void sctp_endpoint_free(struct sctp_endpoint *ep) | |
174 | { | |
0022d2dd | 175 | ep->base.dead = true; |
cfdeef32 | 176 | |
cbabf463 | 177 | inet_sk_set_state(ep->base.sk, SCTP_SS_CLOSED); |
cfdeef32 VY |
178 | |
179 | /* Unlink this endpoint, so we can't find it again! */ | |
180 | sctp_unhash_endpoint(ep); | |
181 | ||
1da177e4 LT |
182 | sctp_endpoint_put(ep); |
183 | } | |
184 | ||
185 | /* Final destructor for endpoint. */ | |
186 | static void sctp_endpoint_destroy(struct sctp_endpoint *ep) | |
187 | { | |
0a2fbac1 | 188 | struct sock *sk; |
1da177e4 | 189 | |
bb33381d DB |
190 | if (unlikely(!ep->base.dead)) { |
191 | WARN(1, "Attempt to destroy undead endpoint %p!\n", ep); | |
192 | return; | |
193 | } | |
1da177e4 | 194 | |
b68dbcab VY |
195 | /* Free the digest buffer */ |
196 | kfree(ep->digest); | |
197 | ||
a29a5bd4 VY |
198 | /* SCTP-AUTH: Free up AUTH releated data such as shared keys |
199 | * chunks and hmacs arrays that were allocated | |
200 | */ | |
201 | sctp_auth_destroy_keys(&ep->endpoint_shared_keys); | |
03f96127 | 202 | sctp_auth_free(ep); |
a29a5bd4 | 203 | |
1da177e4 LT |
204 | /* Cleanup. */ |
205 | sctp_inq_free(&ep->base.inqueue); | |
206 | sctp_bind_addr_free(&ep->base.bind_addr); | |
207 | ||
570617e7 | 208 | memset(ep->secret_key, 0, sizeof(ep->secret_key)); |
b5c37fe6 | 209 | |
0a2fbac1 | 210 | sk = ep->base.sk; |
7f304b9e XL |
211 | /* Remove and free the port */ |
212 | if (sctp_sk(sk)->bind_hash) | |
213 | sctp_put_port(sk); | |
0a2fbac1 | 214 | |
7f304b9e XL |
215 | sctp_sk(sk)->ep = NULL; |
216 | /* Give up our hold on the sock */ | |
217 | sock_put(sk); | |
1da177e4 | 218 | |
ff2266cd DB |
219 | kfree(ep); |
220 | SCTP_DBG_OBJCNT_DEC(ep); | |
1da177e4 LT |
221 | } |
222 | ||
223 | /* Hold a reference to an endpoint. */ | |
224 | void sctp_endpoint_hold(struct sctp_endpoint *ep) | |
225 | { | |
c638457a | 226 | refcount_inc(&ep->base.refcnt); |
1da177e4 LT |
227 | } |
228 | ||
229 | /* Release a reference to an endpoint and clean up if there are | |
230 | * no more references. | |
231 | */ | |
232 | void sctp_endpoint_put(struct sctp_endpoint *ep) | |
233 | { | |
c638457a | 234 | if (refcount_dec_and_test(&ep->base.refcnt)) |
1da177e4 LT |
235 | sctp_endpoint_destroy(ep); |
236 | } | |
237 | ||
238 | /* Is this the endpoint we are looking for? */ | |
239 | struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep, | |
4cdadcbc | 240 | struct net *net, |
1da177e4 LT |
241 | const union sctp_addr *laddr) |
242 | { | |
559cf710 | 243 | struct sctp_endpoint *retval = NULL; |
1da177e4 | 244 | |
4cdadcbc EB |
245 | if ((htons(ep->base.bind_addr.port) == laddr->v4.sin_port) && |
246 | net_eq(sock_net(ep->base.sk), net)) { | |
1da177e4 | 247 | if (sctp_bind_addr_match(&ep->base.bind_addr, laddr, |
559cf710 | 248 | sctp_sk(ep->base.sk))) |
1da177e4 | 249 | retval = ep; |
1da177e4 LT |
250 | } |
251 | ||
1da177e4 LT |
252 | return retval; |
253 | } | |
254 | ||
255 | /* Find the association that goes with this chunk. | |
4f008781 XL |
256 | * We lookup the transport from hashtable at first, then get association |
257 | * through t->assoc. | |
1da177e4 | 258 | */ |
c79c0666 | 259 | struct sctp_association *sctp_endpoint_lookup_assoc( |
1da177e4 LT |
260 | const struct sctp_endpoint *ep, |
261 | const union sctp_addr *paddr, | |
262 | struct sctp_transport **transport) | |
263 | { | |
123ed979 | 264 | struct sctp_association *asoc = NULL; |
4f008781 | 265 | struct sctp_transport *t; |
1da177e4 | 266 | |
123ed979 | 267 | *transport = NULL; |
deb85a6e VY |
268 | |
269 | /* If the local port is not set, there can't be any associations | |
270 | * on this endpoint. | |
271 | */ | |
272 | if (!ep->base.bind_addr.port) | |
5cb2cd68 XL |
273 | return NULL; |
274 | ||
275 | rcu_read_lock(); | |
4f008781 | 276 | t = sctp_epaddr_lookup_transport(ep, paddr); |
dd7445ad | 277 | if (!t) |
4f008781 | 278 | goto out; |
deb85a6e | 279 | |
4f008781 XL |
280 | *transport = t; |
281 | asoc = t->asoc; | |
deb85a6e | 282 | out: |
5cb2cd68 | 283 | rcu_read_unlock(); |
123ed979 | 284 | return asoc; |
1da177e4 LT |
285 | } |
286 | ||
1da177e4 LT |
287 | /* Look for any peeled off association from the endpoint that matches the |
288 | * given peer address. | |
289 | */ | |
53066538 XL |
290 | bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep, |
291 | const union sctp_addr *paddr) | |
1da177e4 | 292 | { |
1da177e4 LT |
293 | struct sctp_sockaddr_entry *addr; |
294 | struct sctp_bind_addr *bp; | |
4110cc25 | 295 | struct net *net = sock_net(ep->base.sk); |
1da177e4 | 296 | |
1da177e4 | 297 | bp = &ep->base.bind_addr; |
559cf710 VY |
298 | /* This function is called with the socket lock held, |
299 | * so the address_list can not change. | |
300 | */ | |
301 | list_for_each_entry(addr, &bp->address_list, list) { | |
4110cc25 | 302 | if (sctp_has_association(net, &addr->a, paddr)) |
53066538 | 303 | return true; |
1da177e4 | 304 | } |
1da177e4 | 305 | |
53066538 | 306 | return false; |
1da177e4 LT |
307 | } |
308 | ||
309 | /* Do delayed input processing. This is scheduled by sctp_rcv(). | |
310 | * This may be called on BH or task time. | |
311 | */ | |
c4028958 | 312 | static void sctp_endpoint_bh_rcv(struct work_struct *work) |
1da177e4 | 313 | { |
c4028958 DH |
314 | struct sctp_endpoint *ep = |
315 | container_of(work, struct sctp_endpoint, | |
316 | base.inqueue.immediate); | |
1da177e4 LT |
317 | struct sctp_association *asoc; |
318 | struct sock *sk; | |
55e26eb9 | 319 | struct net *net; |
1da177e4 LT |
320 | struct sctp_transport *transport; |
321 | struct sctp_chunk *chunk; | |
322 | struct sctp_inq *inqueue; | |
bfc6f827 | 323 | union sctp_subtype subtype; |
52106019 | 324 | enum sctp_state state; |
1da177e4 | 325 | int error = 0; |
42b2aa86 | 326 | int first_time = 1; /* is this the first time through the loop */ |
1da177e4 LT |
327 | |
328 | if (ep->base.dead) | |
329 | return; | |
330 | ||
331 | asoc = NULL; | |
332 | inqueue = &ep->base.inqueue; | |
333 | sk = ep->base.sk; | |
55e26eb9 | 334 | net = sock_net(sk); |
1da177e4 LT |
335 | |
336 | while (NULL != (chunk = sctp_inq_pop(inqueue))) { | |
337 | subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type); | |
338 | ||
bbd0d598 VY |
339 | /* If the first chunk in the packet is AUTH, do special |
340 | * processing specified in Section 6.3 of SCTP-AUTH spec | |
341 | */ | |
342 | if (first_time && (subtype.chunk == SCTP_CID_AUTH)) { | |
343 | struct sctp_chunkhdr *next_hdr; | |
344 | ||
345 | next_hdr = sctp_inq_peek(inqueue); | |
346 | if (!next_hdr) | |
347 | goto normal; | |
348 | ||
349 | /* If the next chunk is COOKIE-ECHO, skip the AUTH | |
350 | * chunk while saving a pointer to it so we can do | |
351 | * Authentication later (during cookie-echo | |
352 | * processing). | |
353 | */ | |
354 | if (next_hdr->type == SCTP_CID_COOKIE_ECHO) { | |
355 | chunk->auth_chunk = skb_clone(chunk->skb, | |
356 | GFP_ATOMIC); | |
357 | chunk->auth = 1; | |
358 | continue; | |
359 | } | |
360 | } | |
361 | normal: | |
1da177e4 LT |
362 | /* We might have grown an association since last we |
363 | * looked, so try again. | |
364 | * | |
365 | * This happens when we've just processed our | |
366 | * COOKIE-ECHO chunk. | |
367 | */ | |
368 | if (NULL == chunk->asoc) { | |
369 | asoc = sctp_endpoint_lookup_assoc(ep, | |
370 | sctp_source(chunk), | |
371 | &transport); | |
372 | chunk->asoc = asoc; | |
373 | chunk->transport = transport; | |
374 | } | |
375 | ||
376 | state = asoc ? asoc->state : SCTP_STATE_CLOSED; | |
bbd0d598 VY |
377 | if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth) |
378 | continue; | |
1da177e4 LT |
379 | |
380 | /* Remember where the last DATA chunk came from so we | |
381 | * know where to send the SACK. | |
382 | */ | |
383 | if (asoc && sctp_chunk_is_data(chunk)) | |
384 | asoc->peer.last_data_from = chunk->transport; | |
196d6759 | 385 | else { |
b01a2407 | 386 | SCTP_INC_STATS(sock_net(ep->base.sk), SCTP_MIB_INCTRLCHUNKS); |
196d6759 MB |
387 | if (asoc) |
388 | asoc->stats.ictrlchunks++; | |
389 | } | |
1da177e4 LT |
390 | |
391 | if (chunk->transport) | |
e575235f | 392 | chunk->transport->last_time_heard = ktime_get(); |
1da177e4 | 393 | |
55e26eb9 | 394 | error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype, state, |
d808ad9a | 395 | ep, asoc, chunk, GFP_ATOMIC); |
1da177e4 LT |
396 | |
397 | if (error && chunk) | |
398 | chunk->pdiscard = 1; | |
399 | ||
400 | /* Check to see if the endpoint is freed in response to | |
401 | * the incoming chunk. If so, get out of the while loop. | |
402 | */ | |
403 | if (!sctp_sk(sk)->ep) | |
404 | break; | |
bbd0d598 VY |
405 | |
406 | if (first_time) | |
407 | first_time = 0; | |
1da177e4 LT |
408 | } |
409 | } |