1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999-2000 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 * Copyright (c) 2001 Intel Corp.
7 * Copyright (c) 2001 Nokia, Inc.
8 * Copyright (c) 2001 La Monte H.P. Yarroll
9 *
10 * These functions manipulate an sctp event. The struct ulpevent is used
11 * to carry notifications and data to the ULP (sockets).
12 *
13 * Please send any bug reports or fixes you make to the
14 * email address(es):
15 * lksctp developers <linux-sctp@vger.kernel.org>
16 *
17 * Written or modified by:
18 * Jon Grimm <jgrimm@us.ibm.com>
19 * La Monte H.P. Yarroll <piggy@acm.org>
20 * Ardelle Fan <ardelle.fan@intel.com>
21 * Sridhar Samudrala <sri@us.ibm.com>
22 */
23
24 #include <linux/slab.h>
25 #include <linux/types.h>
26 #include <linux/skbuff.h>
27 #include <net/sctp/structs.h>
28 #include <net/sctp/sctp.h>
29 #include <net/sctp/sm.h>
30
31 static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
32 struct sctp_association *asoc);
33 static void sctp_ulpevent_release_data(struct sctp_ulpevent *event);
34 static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event);
35
36
37 /* Initialize an ULP event from an given skb. */
38 static void sctp_ulpevent_init(struct sctp_ulpevent *event,
39 __u16 msg_flags,
40 unsigned int len)
41 {
42 memset(event, 0, sizeof(struct sctp_ulpevent));
43 event->msg_flags = msg_flags;
44 event->rmem_len = len;
45 }
46
47 /* Create a new sctp_ulpevent. */
48 static struct sctp_ulpevent *sctp_ulpevent_new(int size, __u16 msg_flags,
49 gfp_t gfp)
50 {
51 struct sctp_ulpevent *event;
52 struct sk_buff *skb;
53
54 skb = alloc_skb(size, gfp);
55 if (!skb)
56 goto fail;
57
58 event = sctp_skb2event(skb);
59 sctp_ulpevent_init(event, msg_flags, skb->truesize);
60
61 return event;
62
63 fail:
64 return NULL;
65 }
66
67 /* Is this a MSG_NOTIFICATION? */
68 int sctp_ulpevent_is_notification(const struct sctp_ulpevent *event)
69 {
70 return MSG_NOTIFICATION == (event->msg_flags & MSG_NOTIFICATION);
71 }
72
73 /* Hold the association in case the msg_name needs read out of
74 * the association.
75 */
76 static inline void sctp_ulpevent_set_owner(struct sctp_ulpevent *event,
77 const struct sctp_association *asoc)
78 {
79 struct sctp_chunk *chunk = event->chunk;
80 struct sk_buff *skb;
81
82 /* Cast away the const, as we are just wanting to
83 * bump the reference count.
84 */
85 sctp_association_hold((struct sctp_association *)asoc);
86 skb = sctp_event2skb(event);
87 event->asoc = (struct sctp_association *)asoc;
88 atomic_add(event->rmem_len, &event->asoc->rmem_alloc);
89 sctp_skb_set_owner_r(skb, asoc->base.sk);
90 if (chunk && chunk->head_skb && !chunk->head_skb->sk)
91 chunk->head_skb->sk = asoc->base.sk;
92 }
93
94 /* A simple destructor to give up the reference to the association. */
95 static inline void sctp_ulpevent_release_owner(struct sctp_ulpevent *event)
96 {
97 struct sctp_association *asoc = event->asoc;
98
99 atomic_sub(event->rmem_len, &asoc->rmem_alloc);
100 sctp_association_put(asoc);
101 }
102
103 /* Create and initialize an SCTP_ASSOC_CHANGE event.
104 *
105 * 5.3.1.1 SCTP_ASSOC_CHANGE
106 *
107 * Communication notifications inform the ULP that an SCTP association
108 * has either begun or ended. The identifier for a new association is
109 * provided by this notification.
110 *
111 * Note: There is no field checking here. If a field is unused it will be
112 * zero'd out.
113 */
114 struct sctp_ulpevent *sctp_ulpevent_make_assoc_change(
115 const struct sctp_association *asoc,
116 __u16 flags, __u16 state, __u16 error, __u16 outbound,
117 __u16 inbound, struct sctp_chunk *chunk, gfp_t gfp)
118 {
119 struct sctp_ulpevent *event;
120 struct sctp_assoc_change *sac;
121 struct sk_buff *skb;
122
123 /* If the lower layer passed in the chunk, it will be
124 * an ABORT, so we need to include it in the sac_info.
125 */
126 if (chunk) {
127 /* Copy the chunk data to a new skb and reserve enough
128 * head room to use as notification.
129 */
130 skb = skb_copy_expand(chunk->skb,
131 sizeof(struct sctp_assoc_change), 0, gfp);
132
133 if (!skb)
134 goto fail;
135
136 /* Embed the event fields inside the cloned skb. */
137 event = sctp_skb2event(skb);
138 sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
139
140 /* Include the notification structure */
141 sac = skb_push(skb, sizeof(struct sctp_assoc_change));
142
143 /* Trim the buffer to the right length. */
144 skb_trim(skb, sizeof(struct sctp_assoc_change) +
145 ntohs(chunk->chunk_hdr->length) -
146 sizeof(struct sctp_chunkhdr));
147 } else {
148 event = sctp_ulpevent_new(sizeof(struct sctp_assoc_change),
149 MSG_NOTIFICATION, gfp);
150 if (!event)
151 goto fail;
152
153 skb = sctp_event2skb(event);
154 sac = skb_put(skb, sizeof(struct sctp_assoc_change));
155 }
156
157 /* Socket Extensions for SCTP
158 * 5.3.1.1 SCTP_ASSOC_CHANGE
159 *
160 * sac_type:
161 * It should be SCTP_ASSOC_CHANGE.
162 */
163 sac->sac_type = SCTP_ASSOC_CHANGE;
164
165 /* Socket Extensions for SCTP
166 * 5.3.1.1 SCTP_ASSOC_CHANGE
167 *
168 * sac_state: 32 bits (signed integer)
169 * This field holds one of a number of values that communicate the
170 * event that happened to the association.
171 */
172 sac->sac_state = state;
173
174 /* Socket Extensions for SCTP
175 * 5.3.1.1 SCTP_ASSOC_CHANGE
176 *
177 * sac_flags: 16 bits (unsigned integer)
178 * Currently unused.
179 */
180 sac->sac_flags = 0;
181
182 /* Socket Extensions for SCTP
183 * 5.3.1.1 SCTP_ASSOC_CHANGE
184 *
185 * sac_length: sizeof (__u32)
186 * This field is the total length of the notification data, including
187 * the notification header.
188 */
189 sac->sac_length = skb->len;
190
191 /* Socket Extensions for SCTP
192 * 5.3.1.1 SCTP_ASSOC_CHANGE
193 *
194 * sac_error: 32 bits (signed integer)
195 *
196 * If the state was reached due to a error condition (e.g.
197 * COMMUNICATION_LOST) any relevant error information is available in
198 * this field. This corresponds to the protocol error codes defined in
199 * [SCTP].
200 */
201 sac->sac_error = error;
202
203 /* Socket Extensions for SCTP
204 * 5.3.1.1 SCTP_ASSOC_CHANGE
205 *
206 * sac_outbound_streams: 16 bits (unsigned integer)
207 * sac_inbound_streams: 16 bits (unsigned integer)
208 *
209 * The maximum number of streams allowed in each direction are
210 * available in sac_outbound_streams and sac_inbound streams.
211 */
212 sac->sac_outbound_streams = outbound;
213 sac->sac_inbound_streams = inbound;
214
215 /* Socket Extensions for SCTP
216 * 5.3.1.1 SCTP_ASSOC_CHANGE
217 *
218 * sac_assoc_id: sizeof (sctp_assoc_t)
219 *
220 * The association id field, holds the identifier for the association.
221 * All notifications for a given association have the same association
222 * identifier. For TCP style socket, this field is ignored.
223 */
224 sctp_ulpevent_set_owner(event, asoc);
225 sac->sac_assoc_id = sctp_assoc2id(asoc);
226
227 return event;
228
229 fail:
230 return NULL;
231 }
232
233 /* Create and initialize an SCTP_PEER_ADDR_CHANGE event.
234 *
235 * Socket Extensions for SCTP - draft-01
236 * 5.3.1.2 SCTP_PEER_ADDR_CHANGE
237 *
238 * When a destination address on a multi-homed peer encounters a change
239 * an interface details event is sent.
240 */
241 static struct sctp_ulpevent *sctp_ulpevent_make_peer_addr_change(
242 const struct sctp_association *asoc,
243 const struct sockaddr_storage *aaddr,
244 int flags, int state, int error, gfp_t gfp)
245 {
246 struct sctp_ulpevent *event;
247 struct sctp_paddr_change *spc;
248 struct sk_buff *skb;
249
250 event = sctp_ulpevent_new(sizeof(struct sctp_paddr_change),
251 MSG_NOTIFICATION, gfp);
252 if (!event)
253 goto fail;
254
255 skb = sctp_event2skb(event);
256 spc = skb_put(skb, sizeof(struct sctp_paddr_change));
257
258 /* Sockets API Extensions for SCTP
259 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
260 *
261 * spc_type:
262 *
263 * It should be SCTP_PEER_ADDR_CHANGE.
264 */
265 spc->spc_type = SCTP_PEER_ADDR_CHANGE;
266
267 /* Sockets API Extensions for SCTP
268 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
269 *
270 * spc_length: sizeof (__u32)
271 *
272 * This field is the total length of the notification data, including
273 * the notification header.
274 */
275 spc->spc_length = sizeof(struct sctp_paddr_change);
276
277 /* Sockets API Extensions for SCTP
278 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
279 *
280 * spc_flags: 16 bits (unsigned integer)
281 * Currently unused.
282 */
283 spc->spc_flags = 0;
284
285 /* Sockets API Extensions for SCTP
286 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
287 *
288 * spc_state: 32 bits (signed integer)
289 *
290 * This field holds one of a number of values that communicate the
291 * event that happened to the address.
292 */
293 spc->spc_state = state;
294
295 /* Sockets API Extensions for SCTP
296 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
297 *
298 * spc_error: 32 bits (signed integer)
299 *
300 * If the state was reached due to any error condition (e.g.
301 * ADDRESS_UNREACHABLE) any relevant error information is available in
302 * this field.
303 */
304 spc->spc_error = error;
305
306 /* Socket Extensions for SCTP
307 * 5.3.1.1 SCTP_ASSOC_CHANGE
308 *
309 * spc_assoc_id: sizeof (sctp_assoc_t)
310 *
311 * The association id field, holds the identifier for the association.
312 * All notifications for a given association have the same association
313 * identifier. For TCP style socket, this field is ignored.
314 */
315 sctp_ulpevent_set_owner(event, asoc);
316 spc->spc_assoc_id = sctp_assoc2id(asoc);
317
318 /* Sockets API Extensions for SCTP
319 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
320 *
321 * spc_aaddr: sizeof (struct sockaddr_storage)
322 *
323 * The affected address field, holds the remote peer's address that is
324 * encountering the change of state.
325 */
326 memcpy(&spc->spc_aaddr, aaddr, sizeof(struct sockaddr_storage));
327
328 /* Map ipv4 address into v4-mapped-on-v6 address. */
329 sctp_get_pf_specific(asoc->base.sk->sk_family)->addr_to_user(
330 sctp_sk(asoc->base.sk),
331 (union sctp_addr *)&spc->spc_aaddr);
332
333 return event;
334
335 fail:
336 return NULL;
337 }
338
339 void sctp_ulpevent_notify_peer_addr_change(struct sctp_transport *transport,
340 int state, int error)
341 {
342 struct sctp_association *asoc = transport->asoc;
343 struct sockaddr_storage addr;
344 struct sctp_ulpevent *event;
345
346 if (asoc->state < SCTP_STATE_ESTABLISHED)
347 return;
348
349 memset(&addr, 0, sizeof(struct sockaddr_storage));
350 memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len);
351
352 event = sctp_ulpevent_make_peer_addr_change(asoc, &addr, 0, state,
353 error, GFP_ATOMIC);
354 if (event)
355 asoc->stream.si->enqueue_event(&asoc->ulpq, event);
356 }
357
358 /* Create and initialize an SCTP_REMOTE_ERROR notification.
359 *
360 * Note: This assumes that the chunk->skb->data already points to the
361 * operation error payload.
362 *
363 * Socket Extensions for SCTP - draft-01
364 * 5.3.1.3 SCTP_REMOTE_ERROR
365 *
366 * A remote peer may send an Operational Error message to its peer.
367 * This message indicates a variety of error conditions on an
368 * association. The entire error TLV as it appears on the wire is
369 * included in a SCTP_REMOTE_ERROR event. Please refer to the SCTP
370 * specification [SCTP] and any extensions for a list of possible
371 * error formats.
372 */
373 struct sctp_ulpevent *
374 sctp_ulpevent_make_remote_error(const struct sctp_association *asoc,
375 struct sctp_chunk *chunk, __u16 flags,
376 gfp_t gfp)
377 {
378 struct sctp_remote_error *sre;
379 struct sctp_ulpevent *event;
380 struct sctp_errhdr *ch;
381 struct sk_buff *skb;
382 __be16 cause;
383 int elen;
384
385 ch = (struct sctp_errhdr *)(chunk->skb->data);
386 cause = ch->cause;
387 elen = SCTP_PAD4(ntohs(ch->length)) - sizeof(*ch);
388
389 /* Pull off the ERROR header. */
390 skb_pull(chunk->skb, sizeof(*ch));
391
392 /* Copy the skb to a new skb with room for us to prepend
393 * notification with.
394 */
395 skb = skb_copy_expand(chunk->skb, sizeof(*sre), 0, gfp);
396
397 /* Pull off the rest of the cause TLV from the chunk. */
398 skb_pull(chunk->skb, elen);
399 if (!skb)
400 goto fail;
401
402 /* Embed the event fields inside the cloned skb. */
403 event = sctp_skb2event(skb);
404 sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
405
406 sre = skb_push(skb, sizeof(*sre));
407
408 /* Trim the buffer to the right length. */
409 skb_trim(skb, sizeof(*sre) + elen);
410
411 /* RFC6458, Section 6.1.3. SCTP_REMOTE_ERROR */
412 memset(sre, 0, sizeof(*sre));
413 sre->sre_type = SCTP_REMOTE_ERROR;
414 sre->sre_flags = 0;
415 sre->sre_length = skb->len;
416 sre->sre_error = cause;
417 sctp_ulpevent_set_owner(event, asoc);
418 sre->sre_assoc_id = sctp_assoc2id(asoc);
419
420 return event;
421 fail:
422 return NULL;
423 }
424
425 /* Create and initialize a SCTP_SEND_FAILED notification.
426 *
427 * Socket Extensions for SCTP - draft-01
428 * 5.3.1.4 SCTP_SEND_FAILED
429 */
430 struct sctp_ulpevent *sctp_ulpevent_make_send_failed(
431 const struct sctp_association *asoc, struct sctp_chunk *chunk,
432 __u16 flags, __u32 error, gfp_t gfp)
433 {
434 struct sctp_ulpevent *event;
435 struct sctp_send_failed *ssf;
436 struct sk_buff *skb;
437
438 /* Pull off any padding. */
439 int len = ntohs(chunk->chunk_hdr->length);
440
441 /* Make skb with more room so we can prepend notification. */
442 skb = skb_copy_expand(chunk->skb,
443 sizeof(struct sctp_send_failed), /* headroom */
444 0, /* tailroom */
445 gfp);
446 if (!skb)
447 goto fail;
448
449 /* Pull off the common chunk header and DATA header. */
450 skb_pull(skb, sctp_datachk_len(&asoc->stream));
451 len -= sctp_datachk_len(&asoc->stream);
452
453 /* Embed the event fields inside the cloned skb. */
454 event = sctp_skb2event(skb);
455 sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
456
457 ssf = skb_push(skb, sizeof(struct sctp_send_failed));
458
459 /* Socket Extensions for SCTP
460 * 5.3.1.4 SCTP_SEND_FAILED
461 *
462 * ssf_type:
463 * It should be SCTP_SEND_FAILED.
464 */
465 ssf->ssf_type = SCTP_SEND_FAILED;
466
467 /* Socket Extensions for SCTP
468 * 5.3.1.4 SCTP_SEND_FAILED
469 *
470 * ssf_flags: 16 bits (unsigned integer)
471 * The flag value will take one of the following values
472 *
473 * SCTP_DATA_UNSENT - Indicates that the data was never put on
474 * the wire.
475 *
476 * SCTP_DATA_SENT - Indicates that the data was put on the wire.
477 * Note that this does not necessarily mean that the
478 * data was (or was not) successfully delivered.
479 */
480 ssf->ssf_flags = flags;
481
482 /* Socket Extensions for SCTP
483 * 5.3.1.4 SCTP_SEND_FAILED
484 *
485 * ssf_length: sizeof (__u32)
486 * This field is the total length of the notification data, including
487 * the notification header.
488 */
489 ssf->ssf_length = sizeof(struct sctp_send_failed) + len;
490 skb_trim(skb, ssf->ssf_length);
491
492 /* Socket Extensions for SCTP
493 * 5.3.1.4 SCTP_SEND_FAILED
494 *
495 * ssf_error: 16 bits (unsigned integer)
496 * This value represents the reason why the send failed, and if set,
497 * will be a SCTP protocol error code as defined in [SCTP] section
498 * 3.3.10.
499 */
500 ssf->ssf_error = error;
501
502 /* Socket Extensions for SCTP
503 * 5.3.1.4 SCTP_SEND_FAILED
504 *
505 * ssf_info: sizeof (struct sctp_sndrcvinfo)
506 * The original send information associated with the undelivered
507 * message.
508 */
509 memcpy(&ssf->ssf_info, &chunk->sinfo, sizeof(struct sctp_sndrcvinfo));
510
511 /* Per TSVWG discussion with Randy. Allow the application to
512 * reassemble a fragmented message.
513 */
514 ssf->ssf_info.sinfo_flags = chunk->chunk_hdr->flags;
515
516 /* Socket Extensions for SCTP
517 * 5.3.1.4 SCTP_SEND_FAILED
518 *
519 * ssf_assoc_id: sizeof (sctp_assoc_t)
520 * The association id field, sf_assoc_id, holds the identifier for the
521 * association. All notifications for a given association have the
522 * same association identifier. For TCP style socket, this field is
523 * ignored.
524 */
525 sctp_ulpevent_set_owner(event, asoc);
526 ssf->ssf_assoc_id = sctp_assoc2id(asoc);
527 return event;
528
529 fail:
530 return NULL;
531 }
532
533 struct sctp_ulpevent *sctp_ulpevent_make_send_failed_event(
534 const struct sctp_association *asoc, struct sctp_chunk *chunk,
535 __u16 flags, __u32 error, gfp_t gfp)
536 {
537 struct sctp_send_failed_event *ssf;
538 struct sctp_ulpevent *event;
539 struct sk_buff *skb;
540 int len;
541
542 skb = skb_copy_expand(chunk->skb, sizeof(*ssf), 0, gfp);
543 if (!skb)
544 return NULL;
545
546 len = ntohs(chunk->chunk_hdr->length);
547 len -= sctp_datachk_len(&asoc->stream);
548
549 skb_pull(skb, sctp_datachk_len(&asoc->stream));
550 event = sctp_skb2event(skb);
551 sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
552
553 ssf = skb_push(skb, sizeof(*ssf));
554 ssf->ssf_type = SCTP_SEND_FAILED_EVENT;
555 ssf->ssf_flags = flags;
556 ssf->ssf_length = sizeof(*ssf) + len;
557 skb_trim(skb, ssf->ssf_length);
558 ssf->ssf_error = error;
559
560 ssf->ssfe_info.snd_sid = chunk->sinfo.sinfo_stream;
561 ssf->ssfe_info.snd_ppid = chunk->sinfo.sinfo_ppid;
562 ssf->ssfe_info.snd_context = chunk->sinfo.sinfo_context;
563 ssf->ssfe_info.snd_assoc_id = chunk->sinfo.sinfo_assoc_id;
564 ssf->ssfe_info.snd_flags = chunk->chunk_hdr->flags;
565
566 sctp_ulpevent_set_owner(event, asoc);
567 ssf->ssf_assoc_id = sctp_assoc2id(asoc);
568
569 return event;
570 }
571
572 /* Create and initialize a SCTP_SHUTDOWN_EVENT notification.
573 *
574 * Socket Extensions for SCTP - draft-01
575 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
576 */
577 struct sctp_ulpevent *sctp_ulpevent_make_shutdown_event(
578 const struct sctp_association *asoc,
579 __u16 flags, gfp_t gfp)
580 {
581 struct sctp_ulpevent *event;
582 struct sctp_shutdown_event *sse;
583 struct sk_buff *skb;
584
585 event = sctp_ulpevent_new(sizeof(struct sctp_shutdown_event),
586 MSG_NOTIFICATION, gfp);
587 if (!event)
588 goto fail;
589
590 skb = sctp_event2skb(event);
591 sse = skb_put(skb, sizeof(struct sctp_shutdown_event));
592
593 /* Socket Extensions for SCTP
594 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
595 *
596 * sse_type
597 * It should be SCTP_SHUTDOWN_EVENT
598 */
599 sse->sse_type = SCTP_SHUTDOWN_EVENT;
600
601 /* Socket Extensions for SCTP
602 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
603 *
604 * sse_flags: 16 bits (unsigned integer)
605 * Currently unused.
606 */
607 sse->sse_flags = 0;
608
609 /* Socket Extensions for SCTP
610 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
611 *
612 * sse_length: sizeof (__u32)
613 * This field is the total length of the notification data, including
614 * the notification header.
615 */
616 sse->sse_length = sizeof(struct sctp_shutdown_event);
617
618 /* Socket Extensions for SCTP
619 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
620 *
621 * sse_assoc_id: sizeof (sctp_assoc_t)
622 * The association id field, holds the identifier for the association.
623 * All notifications for a given association have the same association
624 * identifier. For TCP style socket, this field is ignored.
625 */
626 sctp_ulpevent_set_owner(event, asoc);
627 sse->sse_assoc_id = sctp_assoc2id(asoc);
628
629 return event;
630
631 fail:
632 return NULL;
633 }
634
635 /* Create and initialize a SCTP_ADAPTATION_INDICATION notification.
636 *
637 * Socket Extensions for SCTP
638 * 5.3.1.6 SCTP_ADAPTATION_INDICATION
639 */
640 struct sctp_ulpevent *sctp_ulpevent_make_adaptation_indication(
641 const struct sctp_association *asoc, gfp_t gfp)
642 {
643 struct sctp_ulpevent *event;
644 struct sctp_adaptation_event *sai;
645 struct sk_buff *skb;
646
647 event = sctp_ulpevent_new(sizeof(struct sctp_adaptation_event),
648 MSG_NOTIFICATION, gfp);
649 if (!event)
650 goto fail;
651
652 skb = sctp_event2skb(event);
653 sai = skb_put(skb, sizeof(struct sctp_adaptation_event));
654
655 sai->sai_type = SCTP_ADAPTATION_INDICATION;
656 sai->sai_flags = 0;
657 sai->sai_length = sizeof(struct sctp_adaptation_event);
658 sai->sai_adaptation_ind = asoc->peer.adaptation_ind;
659 sctp_ulpevent_set_owner(event, asoc);
660 sai->sai_assoc_id = sctp_assoc2id(asoc);
661
662 return event;
663
664 fail:
665 return NULL;
666 }
667
668 /* A message has been received. Package this message as a notification
669 * to pass it to the upper layers. Go ahead and calculate the sndrcvinfo
670 * even if filtered out later.
671 *
672 * Socket Extensions for SCTP
673 * 5.2.2 SCTP Header Information Structure (SCTP_SNDRCV)
674 */
675 struct sctp_ulpevent *sctp_ulpevent_make_rcvmsg(struct sctp_association *asoc,
676 struct sctp_chunk *chunk,
677 gfp_t gfp)
678 {
679 struct sctp_ulpevent *event = NULL;
680 struct sk_buff *skb = chunk->skb;
681 struct sock *sk = asoc->base.sk;
682 size_t padding, datalen;
683 int rx_count;
684
685 /*
686 * check to see if we need to make space for this
687 * new skb, expand the rcvbuffer if needed, or drop
688 * the frame
689 */
690 if (asoc->ep->rcvbuf_policy)
691 rx_count = atomic_read(&asoc->rmem_alloc);
692 else
693 rx_count = atomic_read(&sk->sk_rmem_alloc);
694
695 datalen = ntohs(chunk->chunk_hdr->length);
696
697 if (rx_count >= sk->sk_rcvbuf || !sk_rmem_schedule(sk, skb, datalen))
698 goto fail;
699
700 /* Clone the original skb, sharing the data. */
701 skb = skb_clone(chunk->skb, gfp);
702 if (!skb)
703 goto fail;
704
705 /* Now that all memory allocations for this chunk succeeded, we
706 * can mark it as received so the tsn_map is updated correctly.
707 */
708 if (sctp_tsnmap_mark(&asoc->peer.tsn_map,
709 ntohl(chunk->subh.data_hdr->tsn),
710 chunk->transport))
711 goto fail_mark;
712
713 /* First calculate the padding, so we don't inadvertently
714 * pass up the wrong length to the user.
715 *
716 * RFC 2960 - Section 3.2 Chunk Field Descriptions
717 *
718 * The total length of a chunk(including Type, Length and Value fields)
719 * MUST be a multiple of 4 bytes. If the length of the chunk is not a
720 * multiple of 4 bytes, the sender MUST pad the chunk with all zero
721 * bytes and this padding is not included in the chunk length field.
722 * The sender should never pad with more than 3 bytes. The receiver
723 * MUST ignore the padding bytes.
724 */
725 padding = SCTP_PAD4(datalen) - datalen;
726
727 /* Fixup cloned skb with just this chunks data. */
728 skb_trim(skb, chunk->chunk_end - padding - skb->data);
729
730 /* Embed the event fields inside the cloned skb. */
731 event = sctp_skb2event(skb);
732
733 /* Initialize event with flags 0 and correct length
734 * Since this is a clone of the original skb, only account for
735 * the data of this chunk as other chunks will be accounted separately.
736 */
737 sctp_ulpevent_init(event, 0, skb->len + sizeof(struct sk_buff));
738
739 /* And hold the chunk as we need it for getting the IP headers
740 * later in recvmsg
741 */
742 sctp_chunk_hold(chunk);
743 event->chunk = chunk;
744
745 sctp_ulpevent_receive_data(event, asoc);
746
747 event->stream = ntohs(chunk->subh.data_hdr->stream);
748 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
749 event->flags |= SCTP_UNORDERED;
750 event->cumtsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
751 }
752 event->tsn = ntohl(chunk->subh.data_hdr->tsn);
753 event->msg_flags |= chunk->chunk_hdr->flags;
754
755 return event;
756
757 fail_mark:
758 kfree_skb(skb);
759 fail:
760 return NULL;
761 }
762
763 /* Create a partial delivery related event.
764 *
765 * 5.3.1.7 SCTP_PARTIAL_DELIVERY_EVENT
766 *
767 * When a receiver is engaged in a partial delivery of a
768 * message this notification will be used to indicate
769 * various events.
770 */
771 struct sctp_ulpevent *sctp_ulpevent_make_pdapi(
772 const struct sctp_association *asoc,
773 __u32 indication, __u32 sid, __u32 seq,
774 __u32 flags, gfp_t gfp)
775 {
776 struct sctp_ulpevent *event;
777 struct sctp_pdapi_event *pd;
778 struct sk_buff *skb;
779
780 event = sctp_ulpevent_new(sizeof(struct sctp_pdapi_event),
781 MSG_NOTIFICATION, gfp);
782 if (!event)
783 goto fail;
784
785 skb = sctp_event2skb(event);
786 pd = skb_put(skb, sizeof(struct sctp_pdapi_event));
787
788 /* pdapi_type
789 * It should be SCTP_PARTIAL_DELIVERY_EVENT
790 *
791 * pdapi_flags: 16 bits (unsigned integer)
792 * Currently unused.
793 */
794 pd->pdapi_type = SCTP_PARTIAL_DELIVERY_EVENT;
795 pd->pdapi_flags = flags;
796 pd->pdapi_stream = sid;
797 pd->pdapi_seq = seq;
798
799 /* pdapi_length: 32 bits (unsigned integer)
800 *
801 * This field is the total length of the notification data, including
802 * the notification header. It will generally be sizeof (struct
803 * sctp_pdapi_event).
804 */
805 pd->pdapi_length = sizeof(struct sctp_pdapi_event);
806
807 /* pdapi_indication: 32 bits (unsigned integer)
808 *
809 * This field holds the indication being sent to the application.
810 */
811 pd->pdapi_indication = indication;
812
813 /* pdapi_assoc_id: sizeof (sctp_assoc_t)
814 *
815 * The association id field, holds the identifier for the association.
816 */
817 sctp_ulpevent_set_owner(event, asoc);
818 pd->pdapi_assoc_id = sctp_assoc2id(asoc);
819
820 return event;
821 fail:
822 return NULL;
823 }
824
825 struct sctp_ulpevent *sctp_ulpevent_make_authkey(
826 const struct sctp_association *asoc, __u16 key_id,
827 __u32 indication, gfp_t gfp)
828 {
829 struct sctp_ulpevent *event;
830 struct sctp_authkey_event *ak;
831 struct sk_buff *skb;
832
833 event = sctp_ulpevent_new(sizeof(struct sctp_authkey_event),
834 MSG_NOTIFICATION, gfp);
835 if (!event)
836 goto fail;
837
838 skb = sctp_event2skb(event);
839 ak = skb_put(skb, sizeof(struct sctp_authkey_event));
840
841 ak->auth_type = SCTP_AUTHENTICATION_EVENT;
842 ak->auth_flags = 0;
843 ak->auth_length = sizeof(struct sctp_authkey_event);
844
845 ak->auth_keynumber = key_id;
846 ak->auth_altkeynumber = 0;
847 ak->auth_indication = indication;
848
849 /*
850 * The association id field, holds the identifier for the association.
851 */
852 sctp_ulpevent_set_owner(event, asoc);
853 ak->auth_assoc_id = sctp_assoc2id(asoc);
854
855 return event;
856 fail:
857 return NULL;
858 }
859
860 /*
861 * Socket Extensions for SCTP
862 * 6.3.10. SCTP_SENDER_DRY_EVENT
863 */
864 struct sctp_ulpevent *sctp_ulpevent_make_sender_dry_event(
865 const struct sctp_association *asoc, gfp_t gfp)
866 {
867 struct sctp_ulpevent *event;
868 struct sctp_sender_dry_event *sdry;
869 struct sk_buff *skb;
870
871 event = sctp_ulpevent_new(sizeof(struct sctp_sender_dry_event),
872 MSG_NOTIFICATION, gfp);
873 if (!event)
874 return NULL;
875
876 skb = sctp_event2skb(event);
877 sdry = skb_put(skb, sizeof(struct sctp_sender_dry_event));
878
879 sdry->sender_dry_type = SCTP_SENDER_DRY_EVENT;
880 sdry->sender_dry_flags = 0;
881 sdry->sender_dry_length = sizeof(struct sctp_sender_dry_event);
882 sctp_ulpevent_set_owner(event, asoc);
883 sdry->sender_dry_assoc_id = sctp_assoc2id(asoc);
884
885 return event;
886 }
887
888 struct sctp_ulpevent *sctp_ulpevent_make_stream_reset_event(
889 const struct sctp_association *asoc, __u16 flags, __u16 stream_num,
890 __be16 *stream_list, gfp_t gfp)
891 {
892 struct sctp_stream_reset_event *sreset;
893 struct sctp_ulpevent *event;
894 struct sk_buff *skb;
895 int length, i;
896
897 length = sizeof(struct sctp_stream_reset_event) + 2 * stream_num;
898 event = sctp_ulpevent_new(length, MSG_NOTIFICATION, gfp);
899 if (!event)
900 return NULL;
901
902 skb = sctp_event2skb(event);
903 sreset = skb_put(skb, length);
904
905 sreset->strreset_type = SCTP_STREAM_RESET_EVENT;
906 sreset->strreset_flags = flags;
907 sreset->strreset_length = length;
908 sctp_ulpevent_set_owner(event, asoc);
909 sreset->strreset_assoc_id = sctp_assoc2id(asoc);
910
911 for (i = 0; i < stream_num; i++)
912 sreset->strreset_stream_list[i] = ntohs(stream_list[i]);
913
914 return event;
915 }
916
917 struct sctp_ulpevent *sctp_ulpevent_make_assoc_reset_event(
918 const struct sctp_association *asoc, __u16 flags, __u32 local_tsn,
919 __u32 remote_tsn, gfp_t gfp)
920 {
921 struct sctp_assoc_reset_event *areset;
922 struct sctp_ulpevent *event;
923 struct sk_buff *skb;
924
925 event = sctp_ulpevent_new(sizeof(struct sctp_assoc_reset_event),
926 MSG_NOTIFICATION, gfp);
927 if (!event)
928 return NULL;
929
930 skb = sctp_event2skb(event);
931 areset = skb_put(skb, sizeof(struct sctp_assoc_reset_event));
932
933 areset->assocreset_type = SCTP_ASSOC_RESET_EVENT;
934 areset->assocreset_flags = flags;
935 areset->assocreset_length = sizeof(struct sctp_assoc_reset_event);
936 sctp_ulpevent_set_owner(event, asoc);
937 areset->assocreset_assoc_id = sctp_assoc2id(asoc);
938 areset->assocreset_local_tsn = local_tsn;
939 areset->assocreset_remote_tsn = remote_tsn;
940
941 return event;
942 }
943
944 struct sctp_ulpevent *sctp_ulpevent_make_stream_change_event(
945 const struct sctp_association *asoc, __u16 flags,
946 __u32 strchange_instrms, __u32 strchange_outstrms, gfp_t gfp)
947 {
948 struct sctp_stream_change_event *schange;
949 struct sctp_ulpevent *event;
950 struct sk_buff *skb;
951
952 event = sctp_ulpevent_new(sizeof(struct sctp_stream_change_event),
953 MSG_NOTIFICATION, gfp);
954 if (!event)
955 return NULL;
956
957 skb = sctp_event2skb(event);
958 schange = skb_put(skb, sizeof(struct sctp_stream_change_event));
959
960 schange->strchange_type = SCTP_STREAM_CHANGE_EVENT;
961 schange->strchange_flags = flags;
962 schange->strchange_length = sizeof(struct sctp_stream_change_event);
963 sctp_ulpevent_set_owner(event, asoc);
964 schange->strchange_assoc_id = sctp_assoc2id(asoc);
965 schange->strchange_instrms = strchange_instrms;
966 schange->strchange_outstrms = strchange_outstrms;
967
968 return event;
969 }
970
971 /* Return the notification type, assuming this is a notification
972 * event.
973 */
974 __u16 sctp_ulpevent_get_notification_type(const struct sctp_ulpevent *event)
975 {
976 union sctp_notification *notification;
977 struct sk_buff *skb;
978
979 skb = sctp_event2skb(event);
980 notification = (union sctp_notification *) skb->data;
981 return notification->sn_header.sn_type;
982 }
983
984 /* RFC6458, Section 5.3.2. SCTP Header Information Structure
985 * (SCTP_SNDRCV, DEPRECATED)
986 */
987 void sctp_ulpevent_read_sndrcvinfo(const struct sctp_ulpevent *event,
988 struct msghdr *msghdr)
989 {
990 struct sctp_sndrcvinfo sinfo;
991
992 if (sctp_ulpevent_is_notification(event))
993 return;
994
995 memset(&sinfo, 0, sizeof(sinfo));
996 sinfo.sinfo_stream = event->stream;
997 sinfo.sinfo_ssn = event->ssn;
998 sinfo.sinfo_ppid = event->ppid;
999 sinfo.sinfo_flags = event->flags;
1000 sinfo.sinfo_tsn = event->tsn;
1001 sinfo.sinfo_cumtsn = event->cumtsn;
1002 sinfo.sinfo_assoc_id = sctp_assoc2id(event->asoc);
1003 /* Context value that is set via SCTP_CONTEXT socket option. */
1004 sinfo.sinfo_context = event->asoc->default_rcv_context;
1005 /* These fields are not used while receiving. */
1006 sinfo.sinfo_timetolive = 0;
1007
1008 put_cmsg(msghdr, IPPROTO_SCTP, SCTP_SNDRCV,
1009 sizeof(sinfo), &sinfo);
1010 }
1011
1012 /* RFC6458, Section 5.3.5 SCTP Receive Information Structure
1013 * (SCTP_SNDRCV)
1014 */
1015 void sctp_ulpevent_read_rcvinfo(const struct sctp_ulpevent *event,
1016 struct msghdr *msghdr)
1017 {
1018 struct sctp_rcvinfo rinfo;
1019
1020 if (sctp_ulpevent_is_notification(event))
1021 return;
1022
1023 memset(&rinfo, 0, sizeof(struct sctp_rcvinfo));
1024 rinfo.rcv_sid = event->stream;
1025 rinfo.rcv_ssn = event->ssn;
1026 rinfo.rcv_ppid = event->ppid;
1027 rinfo.rcv_flags = event->flags;
1028 rinfo.rcv_tsn = event->tsn;
1029 rinfo.rcv_cumtsn = event->cumtsn;
1030 rinfo.rcv_assoc_id = sctp_assoc2id(event->asoc);
1031 rinfo.rcv_context = event->asoc->default_rcv_context;
1032
1033 put_cmsg(msghdr, IPPROTO_SCTP, SCTP_RCVINFO,
1034 sizeof(rinfo), &rinfo);
1035 }
1036
1037 /* RFC6458, Section 5.3.6. SCTP Next Receive Information Structure
1038 * (SCTP_NXTINFO)
1039 */
1040 static void __sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event,
1041 struct msghdr *msghdr,
1042 const struct sk_buff *skb)
1043 {
1044 struct sctp_nxtinfo nxtinfo;
1045
1046 memset(&nxtinfo, 0, sizeof(nxtinfo));
1047 nxtinfo.nxt_sid = event->stream;
1048 nxtinfo.nxt_ppid = event->ppid;
1049 nxtinfo.nxt_flags = event->flags;
1050 if (sctp_ulpevent_is_notification(event))
1051 nxtinfo.nxt_flags |= SCTP_NOTIFICATION;
1052 nxtinfo.nxt_length = skb->len;
1053 nxtinfo.nxt_assoc_id = sctp_assoc2id(event->asoc);
1054
1055 put_cmsg(msghdr, IPPROTO_SCTP, SCTP_NXTINFO,
1056 sizeof(nxtinfo), &nxtinfo);
1057 }
1058
1059 void sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event,
1060 struct msghdr *msghdr,
1061 struct sock *sk)
1062 {
1063 struct sk_buff *skb;
1064 int err;
1065
1066 skb = sctp_skb_recv_datagram(sk, MSG_PEEK | MSG_DONTWAIT, &err);
1067 if (skb != NULL) {
1068 __sctp_ulpevent_read_nxtinfo(sctp_skb2event(skb),
1069 msghdr, skb);
1070 /* Just release refcount here. */
1071 kfree_skb(skb);
1072 }
1073 }
1074
1075 /* Do accounting for bytes received and hold a reference to the association
1076 * for each skb.
1077 */
1078 static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
1079 struct sctp_association *asoc)
1080 {
1081 struct sk_buff *skb, *frag;
1082
1083 skb = sctp_event2skb(event);
1084 /* Set the owner and charge rwnd for bytes received. */
1085 sctp_ulpevent_set_owner(event, asoc);
1086 sctp_assoc_rwnd_decrease(asoc, skb_headlen(skb));
1087
1088 if (!skb->data_len)
1089 return;
1090
1091 /* Note: Not clearing the entire event struct as this is just a
1092 * fragment of the real event. However, we still need to do rwnd
1093 * accounting.
1094 * In general, the skb passed from IP can have only 1 level of
1095 * fragments. But we allow multiple levels of fragments.
1096 */
1097 skb_walk_frags(skb, frag)
1098 sctp_ulpevent_receive_data(sctp_skb2event(frag), asoc);
1099 }
1100
1101 /* Do accounting for bytes just read by user and release the references to
1102 * the association.
1103 */
1104 static void sctp_ulpevent_release_data(struct sctp_ulpevent *event)
1105 {
1106 struct sk_buff *skb, *frag;
1107 unsigned int len;
1108
1109 /* Current stack structures assume that the rcv buffer is
1110 * per socket. For UDP style sockets this is not true as
1111 * multiple associations may be on a single UDP-style socket.
1112 * Use the local private area of the skb to track the owning
1113 * association.
1114 */
1115
1116 skb = sctp_event2skb(event);
1117 len = skb->len;
1118
1119 if (!skb->data_len)
1120 goto done;
1121
1122 /* Don't forget the fragments. */
1123 skb_walk_frags(skb, frag) {
1124 /* NOTE: skb_shinfos are recursive. Although IP returns
1125 * skb's with only 1 level of fragments, SCTP reassembly can
1126 * increase the levels.
1127 */
1128 sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
1129 }
1130
1131 done:
1132 sctp_assoc_rwnd_increase(event->asoc, len);
1133 sctp_chunk_put(event->chunk);
1134 sctp_ulpevent_release_owner(event);
1135 }
1136
1137 static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event)
1138 {
1139 struct sk_buff *skb, *frag;
1140
1141 skb = sctp_event2skb(event);
1142
1143 if (!skb->data_len)
1144 goto done;
1145
1146 /* Don't forget the fragments. */
1147 skb_walk_frags(skb, frag) {
1148 /* NOTE: skb_shinfos are recursive. Although IP returns
1149 * skb's with only 1 level of fragments, SCTP reassembly can
1150 * increase the levels.
1151 */
1152 sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
1153 }
1154
1155 done:
1156 sctp_chunk_put(event->chunk);
1157 sctp_ulpevent_release_owner(event);
1158 }
1159
1160 /* Free a ulpevent that has an owner. It includes releasing the reference
1161 * to the owner, updating the rwnd in case of a DATA event and freeing the
1162 * skb.
1163 */
1164 void sctp_ulpevent_free(struct sctp_ulpevent *event)
1165 {
1166 if (sctp_ulpevent_is_notification(event))
1167 sctp_ulpevent_release_owner(event);
1168 else
1169 sctp_ulpevent_release_data(event);
1170
1171 kfree_skb(sctp_event2skb(event));
1172 }
1173
1174 /* Purge the skb lists holding ulpevents. */
1175 unsigned int sctp_queue_purge_ulpevents(struct sk_buff_head *list)
1176 {
1177 struct sk_buff *skb;
1178 unsigned int data_unread = 0;
1179
1180 while ((skb = skb_dequeue(list)) != NULL) {
1181 struct sctp_ulpevent *event = sctp_skb2event(skb);
1182
1183 if (!sctp_ulpevent_is_notification(event))
1184 data_unread += skb->len;
1185
1186 sctp_ulpevent_free(event);
1187 }
1188
1189 return data_unread;
1190 }
1191
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