1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
6 * Copyright (c) 2001 Nokia, Inc.
7 * Copyright (c) 2001 La Monte H.P. Yarroll
8 *
9 * These functions manipulate an sctp event. The struct ulpevent is used
10 * to carry notifications and data to the ULP (sockets).
11 *
12 * This SCTP implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
16 * any later version.
17 *
18 * This SCTP implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
28 *
29 * Please send any bug reports or fixes you make to the
30 * email address(es):
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
32 *
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
35 *
36 * Written or modified by:
37 * Jon Grimm <jgrimm@us.ibm.com>
38 * La Monte H.P. Yarroll <piggy@acm.org>
39 * Ardelle Fan <ardelle.fan@intel.com>
40 * Sridhar Samudrala <sri@us.ibm.com>
41 *
42 * Any bugs reported given to us we will try to fix... any fixes shared will
43 * be incorporated into the next SCTP release.
44 */
45
46 #include <linux/slab.h>
47 #include <linux/types.h>
48 #include <linux/skbuff.h>
49 #include <net/sctp/structs.h>
50 #include <net/sctp/sctp.h>
51 #include <net/sctp/sm.h>
52
53 static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
54 struct sctp_association *asoc);
55 static void sctp_ulpevent_release_data(struct sctp_ulpevent *event);
56 static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event);
57
58
59 /* Initialize an ULP event from an given skb. */
sctp_ulpevent_init(struct sctp_ulpevent * event,int msg_flags,unsigned int len)60 SCTP_STATIC void sctp_ulpevent_init(struct sctp_ulpevent *event,
61 int msg_flags,
62 unsigned int len)
63 {
64 memset(event, 0, sizeof(struct sctp_ulpevent));
65 event->msg_flags = msg_flags;
66 event->rmem_len = len;
67 }
68
69 /* Create a new sctp_ulpevent. */
sctp_ulpevent_new(int size,int msg_flags,gfp_t gfp)70 SCTP_STATIC struct sctp_ulpevent *sctp_ulpevent_new(int size, int msg_flags,
71 gfp_t gfp)
72 {
73 struct sctp_ulpevent *event;
74 struct sk_buff *skb;
75
76 skb = alloc_skb(size, gfp);
77 if (!skb)
78 goto fail;
79
80 event = sctp_skb2event(skb);
81 sctp_ulpevent_init(event, msg_flags, skb->truesize);
82
83 return event;
84
85 fail:
86 return NULL;
87 }
88
89 /* Is this a MSG_NOTIFICATION? */
sctp_ulpevent_is_notification(const struct sctp_ulpevent * event)90 int sctp_ulpevent_is_notification(const struct sctp_ulpevent *event)
91 {
92 return MSG_NOTIFICATION == (event->msg_flags & MSG_NOTIFICATION);
93 }
94
95 /* Hold the association in case the msg_name needs read out of
96 * the association.
97 */
sctp_ulpevent_set_owner(struct sctp_ulpevent * event,const struct sctp_association * asoc)98 static inline void sctp_ulpevent_set_owner(struct sctp_ulpevent *event,
99 const struct sctp_association *asoc)
100 {
101 struct sk_buff *skb;
102
103 /* Cast away the const, as we are just wanting to
104 * bump the reference count.
105 */
106 sctp_association_hold((struct sctp_association *)asoc);
107 skb = sctp_event2skb(event);
108 event->asoc = (struct sctp_association *)asoc;
109 atomic_add(event->rmem_len, &event->asoc->rmem_alloc);
110 sctp_skb_set_owner_r(skb, asoc->base.sk);
111 }
112
113 /* A simple destructor to give up the reference to the association. */
sctp_ulpevent_release_owner(struct sctp_ulpevent * event)114 static inline void sctp_ulpevent_release_owner(struct sctp_ulpevent *event)
115 {
116 struct sctp_association *asoc = event->asoc;
117
118 atomic_sub(event->rmem_len, &asoc->rmem_alloc);
119 sctp_association_put(asoc);
120 }
121
122 /* Create and initialize an SCTP_ASSOC_CHANGE event.
123 *
124 * 5.3.1.1 SCTP_ASSOC_CHANGE
125 *
126 * Communication notifications inform the ULP that an SCTP association
127 * has either begun or ended. The identifier for a new association is
128 * provided by this notification.
129 *
130 * Note: There is no field checking here. If a field is unused it will be
131 * zero'd out.
132 */
sctp_ulpevent_make_assoc_change(const struct sctp_association * asoc,__u16 flags,__u16 state,__u16 error,__u16 outbound,__u16 inbound,struct sctp_chunk * chunk,gfp_t gfp)133 struct sctp_ulpevent *sctp_ulpevent_make_assoc_change(
134 const struct sctp_association *asoc,
135 __u16 flags, __u16 state, __u16 error, __u16 outbound,
136 __u16 inbound, struct sctp_chunk *chunk, gfp_t gfp)
137 {
138 struct sctp_ulpevent *event;
139 struct sctp_assoc_change *sac;
140 struct sk_buff *skb;
141
142 /* If the lower layer passed in the chunk, it will be
143 * an ABORT, so we need to include it in the sac_info.
144 */
145 if (chunk) {
146 /* Copy the chunk data to a new skb and reserve enough
147 * head room to use as notification.
148 */
149 skb = skb_copy_expand(chunk->skb,
150 sizeof(struct sctp_assoc_change), 0, gfp);
151
152 if (!skb)
153 goto fail;
154
155 /* Embed the event fields inside the cloned skb. */
156 event = sctp_skb2event(skb);
157 sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
158
159 /* Include the notification structure */
160 sac = (struct sctp_assoc_change *)
161 skb_push(skb, sizeof(struct sctp_assoc_change));
162
163 /* Trim the buffer to the right length. */
164 skb_trim(skb, sizeof(struct sctp_assoc_change) +
165 ntohs(chunk->chunk_hdr->length) -
166 sizeof(sctp_chunkhdr_t));
167 } else {
168 event = sctp_ulpevent_new(sizeof(struct sctp_assoc_change),
169 MSG_NOTIFICATION, gfp);
170 if (!event)
171 goto fail;
172
173 skb = sctp_event2skb(event);
174 sac = (struct sctp_assoc_change *) skb_put(skb,
175 sizeof(struct sctp_assoc_change));
176 }
177
178 /* Socket Extensions for SCTP
179 * 5.3.1.1 SCTP_ASSOC_CHANGE
180 *
181 * sac_type:
182 * It should be SCTP_ASSOC_CHANGE.
183 */
184 sac->sac_type = SCTP_ASSOC_CHANGE;
185
186 /* Socket Extensions for SCTP
187 * 5.3.1.1 SCTP_ASSOC_CHANGE
188 *
189 * sac_state: 32 bits (signed integer)
190 * This field holds one of a number of values that communicate the
191 * event that happened to the association.
192 */
193 sac->sac_state = state;
194
195 /* Socket Extensions for SCTP
196 * 5.3.1.1 SCTP_ASSOC_CHANGE
197 *
198 * sac_flags: 16 bits (unsigned integer)
199 * Currently unused.
200 */
201 sac->sac_flags = 0;
202
203 /* Socket Extensions for SCTP
204 * 5.3.1.1 SCTP_ASSOC_CHANGE
205 *
206 * sac_length: sizeof (__u32)
207 * This field is the total length of the notification data, including
208 * the notification header.
209 */
210 sac->sac_length = skb->len;
211
212 /* Socket Extensions for SCTP
213 * 5.3.1.1 SCTP_ASSOC_CHANGE
214 *
215 * sac_error: 32 bits (signed integer)
216 *
217 * If the state was reached due to a error condition (e.g.
218 * COMMUNICATION_LOST) any relevant error information is available in
219 * this field. This corresponds to the protocol error codes defined in
220 * [SCTP].
221 */
222 sac->sac_error = error;
223
224 /* Socket Extensions for SCTP
225 * 5.3.1.1 SCTP_ASSOC_CHANGE
226 *
227 * sac_outbound_streams: 16 bits (unsigned integer)
228 * sac_inbound_streams: 16 bits (unsigned integer)
229 *
230 * The maximum number of streams allowed in each direction are
231 * available in sac_outbound_streams and sac_inbound streams.
232 */
233 sac->sac_outbound_streams = outbound;
234 sac->sac_inbound_streams = inbound;
235
236 /* Socket Extensions for SCTP
237 * 5.3.1.1 SCTP_ASSOC_CHANGE
238 *
239 * sac_assoc_id: sizeof (sctp_assoc_t)
240 *
241 * The association id field, holds the identifier for the association.
242 * All notifications for a given association have the same association
243 * identifier. For TCP style socket, this field is ignored.
244 */
245 sctp_ulpevent_set_owner(event, asoc);
246 sac->sac_assoc_id = sctp_assoc2id(asoc);
247
248 return event;
249
250 fail:
251 return NULL;
252 }
253
254 /* Create and initialize an SCTP_PEER_ADDR_CHANGE event.
255 *
256 * Socket Extensions for SCTP - draft-01
257 * 5.3.1.2 SCTP_PEER_ADDR_CHANGE
258 *
259 * When a destination address on a multi-homed peer encounters a change
260 * an interface details event is sent.
261 */
sctp_ulpevent_make_peer_addr_change(const struct sctp_association * asoc,const struct sockaddr_storage * aaddr,int flags,int state,int error,gfp_t gfp)262 struct sctp_ulpevent *sctp_ulpevent_make_peer_addr_change(
263 const struct sctp_association *asoc,
264 const struct sockaddr_storage *aaddr,
265 int flags, int state, int error, gfp_t gfp)
266 {
267 struct sctp_ulpevent *event;
268 struct sctp_paddr_change *spc;
269 struct sk_buff *skb;
270
271 event = sctp_ulpevent_new(sizeof(struct sctp_paddr_change),
272 MSG_NOTIFICATION, gfp);
273 if (!event)
274 goto fail;
275
276 skb = sctp_event2skb(event);
277 spc = (struct sctp_paddr_change *)
278 skb_put(skb, sizeof(struct sctp_paddr_change));
279
280 /* Sockets API Extensions for SCTP
281 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
282 *
283 * spc_type:
284 *
285 * It should be SCTP_PEER_ADDR_CHANGE.
286 */
287 spc->spc_type = SCTP_PEER_ADDR_CHANGE;
288
289 /* Sockets API Extensions for SCTP
290 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
291 *
292 * spc_length: sizeof (__u32)
293 *
294 * This field is the total length of the notification data, including
295 * the notification header.
296 */
297 spc->spc_length = sizeof(struct sctp_paddr_change);
298
299 /* Sockets API Extensions for SCTP
300 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
301 *
302 * spc_flags: 16 bits (unsigned integer)
303 * Currently unused.
304 */
305 spc->spc_flags = 0;
306
307 /* Sockets API Extensions for SCTP
308 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
309 *
310 * spc_state: 32 bits (signed integer)
311 *
312 * This field holds one of a number of values that communicate the
313 * event that happened to the address.
314 */
315 spc->spc_state = state;
316
317 /* Sockets API Extensions for SCTP
318 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
319 *
320 * spc_error: 32 bits (signed integer)
321 *
322 * If the state was reached due to any error condition (e.g.
323 * ADDRESS_UNREACHABLE) any relevant error information is available in
324 * this field.
325 */
326 spc->spc_error = error;
327
328 /* Socket Extensions for SCTP
329 * 5.3.1.1 SCTP_ASSOC_CHANGE
330 *
331 * spc_assoc_id: sizeof (sctp_assoc_t)
332 *
333 * The association id field, holds the identifier for the association.
334 * All notifications for a given association have the same association
335 * identifier. For TCP style socket, this field is ignored.
336 */
337 sctp_ulpevent_set_owner(event, asoc);
338 spc->spc_assoc_id = sctp_assoc2id(asoc);
339
340 /* Sockets API Extensions for SCTP
341 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
342 *
343 * spc_aaddr: sizeof (struct sockaddr_storage)
344 *
345 * The affected address field, holds the remote peer's address that is
346 * encountering the change of state.
347 */
348 memcpy(&spc->spc_aaddr, aaddr, sizeof(struct sockaddr_storage));
349
350 /* Map ipv4 address into v4-mapped-on-v6 address. */
351 sctp_get_pf_specific(asoc->base.sk->sk_family)->addr_v4map(
352 sctp_sk(asoc->base.sk),
353 (union sctp_addr *)&spc->spc_aaddr);
354
355 return event;
356
357 fail:
358 return NULL;
359 }
360
361 /* Create and initialize an SCTP_REMOTE_ERROR notification.
362 *
363 * Note: This assumes that the chunk->skb->data already points to the
364 * operation error payload.
365 *
366 * Socket Extensions for SCTP - draft-01
367 * 5.3.1.3 SCTP_REMOTE_ERROR
368 *
369 * A remote peer may send an Operational Error message to its peer.
370 * This message indicates a variety of error conditions on an
371 * association. The entire error TLV as it appears on the wire is
372 * included in a SCTP_REMOTE_ERROR event. Please refer to the SCTP
373 * specification [SCTP] and any extensions for a list of possible
374 * error formats.
375 */
sctp_ulpevent_make_remote_error(const struct sctp_association * asoc,struct sctp_chunk * chunk,__u16 flags,gfp_t gfp)376 struct sctp_ulpevent *sctp_ulpevent_make_remote_error(
377 const struct sctp_association *asoc, struct sctp_chunk *chunk,
378 __u16 flags, gfp_t gfp)
379 {
380 struct sctp_ulpevent *event;
381 struct sctp_remote_error *sre;
382 struct sk_buff *skb;
383 sctp_errhdr_t *ch;
384 __be16 cause;
385 int elen;
386
387 ch = (sctp_errhdr_t *)(chunk->skb->data);
388 cause = ch->cause;
389 elen = WORD_ROUND(ntohs(ch->length)) - sizeof(sctp_errhdr_t);
390
391 /* Pull off the ERROR header. */
392 skb_pull(chunk->skb, sizeof(sctp_errhdr_t));
393
394 /* Copy the skb to a new skb with room for us to prepend
395 * notification with.
396 */
397 skb = skb_copy_expand(chunk->skb, sizeof(struct sctp_remote_error),
398 0, gfp);
399
400 /* Pull off the rest of the cause TLV from the chunk. */
401 skb_pull(chunk->skb, elen);
402 if (!skb)
403 goto fail;
404
405 /* Embed the event fields inside the cloned skb. */
406 event = sctp_skb2event(skb);
407 sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
408
409 sre = (struct sctp_remote_error *)
410 skb_push(skb, sizeof(struct sctp_remote_error));
411
412 /* Trim the buffer to the right length. */
413 skb_trim(skb, sizeof(struct sctp_remote_error) + elen);
414
415 /* Socket Extensions for SCTP
416 * 5.3.1.3 SCTP_REMOTE_ERROR
417 *
418 * sre_type:
419 * It should be SCTP_REMOTE_ERROR.
420 */
421 sre->sre_type = SCTP_REMOTE_ERROR;
422
423 /*
424 * Socket Extensions for SCTP
425 * 5.3.1.3 SCTP_REMOTE_ERROR
426 *
427 * sre_flags: 16 bits (unsigned integer)
428 * Currently unused.
429 */
430 sre->sre_flags = 0;
431
432 /* Socket Extensions for SCTP
433 * 5.3.1.3 SCTP_REMOTE_ERROR
434 *
435 * sre_length: sizeof (__u32)
436 *
437 * This field is the total length of the notification data,
438 * including the notification header.
439 */
440 sre->sre_length = skb->len;
441
442 /* Socket Extensions for SCTP
443 * 5.3.1.3 SCTP_REMOTE_ERROR
444 *
445 * sre_error: 16 bits (unsigned integer)
446 * This value represents one of the Operational Error causes defined in
447 * the SCTP specification, in network byte order.
448 */
449 sre->sre_error = cause;
450
451 /* Socket Extensions for SCTP
452 * 5.3.1.3 SCTP_REMOTE_ERROR
453 *
454 * sre_assoc_id: sizeof (sctp_assoc_t)
455 *
456 * The association id field, holds the identifier for the association.
457 * All notifications for a given association have the same association
458 * identifier. For TCP style socket, this field is ignored.
459 */
460 sctp_ulpevent_set_owner(event, asoc);
461 sre->sre_assoc_id = sctp_assoc2id(asoc);
462
463 return event;
464
465 fail:
466 return NULL;
467 }
468
469 /* Create and initialize a SCTP_SEND_FAILED notification.
470 *
471 * Socket Extensions for SCTP - draft-01
472 * 5.3.1.4 SCTP_SEND_FAILED
473 */
sctp_ulpevent_make_send_failed(const struct sctp_association * asoc,struct sctp_chunk * chunk,__u16 flags,__u32 error,gfp_t gfp)474 struct sctp_ulpevent *sctp_ulpevent_make_send_failed(
475 const struct sctp_association *asoc, struct sctp_chunk *chunk,
476 __u16 flags, __u32 error, gfp_t gfp)
477 {
478 struct sctp_ulpevent *event;
479 struct sctp_send_failed *ssf;
480 struct sk_buff *skb;
481
482 /* Pull off any padding. */
483 int len = ntohs(chunk->chunk_hdr->length);
484
485 /* Make skb with more room so we can prepend notification. */
486 skb = skb_copy_expand(chunk->skb,
487 sizeof(struct sctp_send_failed), /* headroom */
488 0, /* tailroom */
489 gfp);
490 if (!skb)
491 goto fail;
492
493 /* Pull off the common chunk header and DATA header. */
494 skb_pull(skb, sizeof(struct sctp_data_chunk));
495 len -= sizeof(struct sctp_data_chunk);
496
497 /* Embed the event fields inside the cloned skb. */
498 event = sctp_skb2event(skb);
499 sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
500
501 ssf = (struct sctp_send_failed *)
502 skb_push(skb, sizeof(struct sctp_send_failed));
503
504 /* Socket Extensions for SCTP
505 * 5.3.1.4 SCTP_SEND_FAILED
506 *
507 * ssf_type:
508 * It should be SCTP_SEND_FAILED.
509 */
510 ssf->ssf_type = SCTP_SEND_FAILED;
511
512 /* Socket Extensions for SCTP
513 * 5.3.1.4 SCTP_SEND_FAILED
514 *
515 * ssf_flags: 16 bits (unsigned integer)
516 * The flag value will take one of the following values
517 *
518 * SCTP_DATA_UNSENT - Indicates that the data was never put on
519 * the wire.
520 *
521 * SCTP_DATA_SENT - Indicates that the data was put on the wire.
522 * Note that this does not necessarily mean that the
523 * data was (or was not) successfully delivered.
524 */
525 ssf->ssf_flags = flags;
526
527 /* Socket Extensions for SCTP
528 * 5.3.1.4 SCTP_SEND_FAILED
529 *
530 * ssf_length: sizeof (__u32)
531 * This field is the total length of the notification data, including
532 * the notification header.
533 */
534 ssf->ssf_length = sizeof(struct sctp_send_failed) + len;
535 skb_trim(skb, ssf->ssf_length);
536
537 /* Socket Extensions for SCTP
538 * 5.3.1.4 SCTP_SEND_FAILED
539 *
540 * ssf_error: 16 bits (unsigned integer)
541 * This value represents the reason why the send failed, and if set,
542 * will be a SCTP protocol error code as defined in [SCTP] section
543 * 3.3.10.
544 */
545 ssf->ssf_error = error;
546
547 /* Socket Extensions for SCTP
548 * 5.3.1.4 SCTP_SEND_FAILED
549 *
550 * ssf_info: sizeof (struct sctp_sndrcvinfo)
551 * The original send information associated with the undelivered
552 * message.
553 */
554 memcpy(&ssf->ssf_info, &chunk->sinfo, sizeof(struct sctp_sndrcvinfo));
555
556 /* Per TSVWG discussion with Randy. Allow the application to
557 * reassemble a fragmented message.
558 */
559 ssf->ssf_info.sinfo_flags = chunk->chunk_hdr->flags;
560
561 /* Socket Extensions for SCTP
562 * 5.3.1.4 SCTP_SEND_FAILED
563 *
564 * ssf_assoc_id: sizeof (sctp_assoc_t)
565 * The association id field, sf_assoc_id, holds the identifier for the
566 * association. All notifications for a given association have the
567 * same association identifier. For TCP style socket, this field is
568 * ignored.
569 */
570 sctp_ulpevent_set_owner(event, asoc);
571 ssf->ssf_assoc_id = sctp_assoc2id(asoc);
572 return event;
573
574 fail:
575 return NULL;
576 }
577
578 /* Create and initialize a SCTP_SHUTDOWN_EVENT notification.
579 *
580 * Socket Extensions for SCTP - draft-01
581 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
582 */
sctp_ulpevent_make_shutdown_event(const struct sctp_association * asoc,__u16 flags,gfp_t gfp)583 struct sctp_ulpevent *sctp_ulpevent_make_shutdown_event(
584 const struct sctp_association *asoc,
585 __u16 flags, gfp_t gfp)
586 {
587 struct sctp_ulpevent *event;
588 struct sctp_shutdown_event *sse;
589 struct sk_buff *skb;
590
591 event = sctp_ulpevent_new(sizeof(struct sctp_shutdown_event),
592 MSG_NOTIFICATION, gfp);
593 if (!event)
594 goto fail;
595
596 skb = sctp_event2skb(event);
597 sse = (struct sctp_shutdown_event *)
598 skb_put(skb, sizeof(struct sctp_shutdown_event));
599
600 /* Socket Extensions for SCTP
601 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
602 *
603 * sse_type
604 * It should be SCTP_SHUTDOWN_EVENT
605 */
606 sse->sse_type = SCTP_SHUTDOWN_EVENT;
607
608 /* Socket Extensions for SCTP
609 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
610 *
611 * sse_flags: 16 bits (unsigned integer)
612 * Currently unused.
613 */
614 sse->sse_flags = 0;
615
616 /* Socket Extensions for SCTP
617 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
618 *
619 * sse_length: sizeof (__u32)
620 * This field is the total length of the notification data, including
621 * the notification header.
622 */
623 sse->sse_length = sizeof(struct sctp_shutdown_event);
624
625 /* Socket Extensions for SCTP
626 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
627 *
628 * sse_assoc_id: sizeof (sctp_assoc_t)
629 * The association id field, holds the identifier for the association.
630 * All notifications for a given association have the same association
631 * identifier. For TCP style socket, this field is ignored.
632 */
633 sctp_ulpevent_set_owner(event, asoc);
634 sse->sse_assoc_id = sctp_assoc2id(asoc);
635
636 return event;
637
638 fail:
639 return NULL;
640 }
641
642 /* Create and initialize a SCTP_ADAPTATION_INDICATION notification.
643 *
644 * Socket Extensions for SCTP
645 * 5.3.1.6 SCTP_ADAPTATION_INDICATION
646 */
sctp_ulpevent_make_adaptation_indication(const struct sctp_association * asoc,gfp_t gfp)647 struct sctp_ulpevent *sctp_ulpevent_make_adaptation_indication(
648 const struct sctp_association *asoc, gfp_t gfp)
649 {
650 struct sctp_ulpevent *event;
651 struct sctp_adaptation_event *sai;
652 struct sk_buff *skb;
653
654 event = sctp_ulpevent_new(sizeof(struct sctp_adaptation_event),
655 MSG_NOTIFICATION, gfp);
656 if (!event)
657 goto fail;
658
659 skb = sctp_event2skb(event);
660 sai = (struct sctp_adaptation_event *)
661 skb_put(skb, sizeof(struct sctp_adaptation_event));
662
663 sai->sai_type = SCTP_ADAPTATION_INDICATION;
664 sai->sai_flags = 0;
665 sai->sai_length = sizeof(struct sctp_adaptation_event);
666 sai->sai_adaptation_ind = asoc->peer.adaptation_ind;
667 sctp_ulpevent_set_owner(event, asoc);
668 sai->sai_assoc_id = sctp_assoc2id(asoc);
669
670 return event;
671
672 fail:
673 return NULL;
674 }
675
676 /* A message has been received. Package this message as a notification
677 * to pass it to the upper layers. Go ahead and calculate the sndrcvinfo
678 * even if filtered out later.
679 *
680 * Socket Extensions for SCTP
681 * 5.2.2 SCTP Header Information Structure (SCTP_SNDRCV)
682 */
sctp_ulpevent_make_rcvmsg(struct sctp_association * asoc,struct sctp_chunk * chunk,gfp_t gfp)683 struct sctp_ulpevent *sctp_ulpevent_make_rcvmsg(struct sctp_association *asoc,
684 struct sctp_chunk *chunk,
685 gfp_t gfp)
686 {
687 struct sctp_ulpevent *event = NULL;
688 struct sk_buff *skb;
689 size_t padding, len;
690 int rx_count;
691
692 /*
693 * check to see if we need to make space for this
694 * new skb, expand the rcvbuffer if needed, or drop
695 * the frame
696 */
697 if (asoc->ep->rcvbuf_policy)
698 rx_count = atomic_read(&asoc->rmem_alloc);
699 else
700 rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);
701
702 if (rx_count >= asoc->base.sk->sk_rcvbuf) {
703
704 if ((asoc->base.sk->sk_userlocks & SOCK_RCVBUF_LOCK) ||
705 (!sk_rmem_schedule(asoc->base.sk, chunk->skb->truesize)))
706 goto fail;
707 }
708
709 /* Clone the original skb, sharing the data. */
710 skb = skb_clone(chunk->skb, gfp);
711 if (!skb)
712 goto fail;
713
714 /* Now that all memory allocations for this chunk succeeded, we
715 * can mark it as received so the tsn_map is updated correctly.
716 */
717 if (sctp_tsnmap_mark(&asoc->peer.tsn_map,
718 ntohl(chunk->subh.data_hdr->tsn)))
719 goto fail_mark;
720
721 /* First calculate the padding, so we don't inadvertently
722 * pass up the wrong length to the user.
723 *
724 * RFC 2960 - Section 3.2 Chunk Field Descriptions
725 *
726 * The total length of a chunk(including Type, Length and Value fields)
727 * MUST be a multiple of 4 bytes. If the length of the chunk is not a
728 * multiple of 4 bytes, the sender MUST pad the chunk with all zero
729 * bytes and this padding is not included in the chunk length field.
730 * The sender should never pad with more than 3 bytes. The receiver
731 * MUST ignore the padding bytes.
732 */
733 len = ntohs(chunk->chunk_hdr->length);
734 padding = WORD_ROUND(len) - len;
735
736 /* Fixup cloned skb with just this chunks data. */
737 skb_trim(skb, chunk->chunk_end - padding - skb->data);
738
739 /* Embed the event fields inside the cloned skb. */
740 event = sctp_skb2event(skb);
741
742 /* Initialize event with flags 0 and correct length
743 * Since this is a clone of the original skb, only account for
744 * the data of this chunk as other chunks will be accounted separately.
745 */
746 sctp_ulpevent_init(event, 0, skb->len + sizeof(struct sk_buff));
747
748 sctp_ulpevent_receive_data(event, asoc);
749
750 event->stream = ntohs(chunk->subh.data_hdr->stream);
751 event->ssn = ntohs(chunk->subh.data_hdr->ssn);
752 event->ppid = chunk->subh.data_hdr->ppid;
753 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
754 event->flags |= SCTP_UNORDERED;
755 event->cumtsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
756 }
757 event->tsn = ntohl(chunk->subh.data_hdr->tsn);
758 event->msg_flags |= chunk->chunk_hdr->flags;
759 event->iif = sctp_chunk_iif(chunk);
760
761 return event;
762
763 fail_mark:
764 kfree_skb(skb);
765 fail:
766 return NULL;
767 }
768
769 /* Create a partial delivery related event.
770 *
771 * 5.3.1.7 SCTP_PARTIAL_DELIVERY_EVENT
772 *
773 * When a receiver is engaged in a partial delivery of a
774 * message this notification will be used to indicate
775 * various events.
776 */
sctp_ulpevent_make_pdapi(const struct sctp_association * asoc,__u32 indication,gfp_t gfp)777 struct sctp_ulpevent *sctp_ulpevent_make_pdapi(
778 const struct sctp_association *asoc, __u32 indication,
779 gfp_t gfp)
780 {
781 struct sctp_ulpevent *event;
782 struct sctp_pdapi_event *pd;
783 struct sk_buff *skb;
784
785 event = sctp_ulpevent_new(sizeof(struct sctp_pdapi_event),
786 MSG_NOTIFICATION, gfp);
787 if (!event)
788 goto fail;
789
790 skb = sctp_event2skb(event);
791 pd = (struct sctp_pdapi_event *)
792 skb_put(skb, sizeof(struct sctp_pdapi_event));
793
794 /* pdapi_type
795 * It should be SCTP_PARTIAL_DELIVERY_EVENT
796 *
797 * pdapi_flags: 16 bits (unsigned integer)
798 * Currently unused.
799 */
800 pd->pdapi_type = SCTP_PARTIAL_DELIVERY_EVENT;
801 pd->pdapi_flags = 0;
802
803 /* pdapi_length: 32 bits (unsigned integer)
804 *
805 * This field is the total length of the notification data, including
806 * the notification header. It will generally be sizeof (struct
807 * sctp_pdapi_event).
808 */
809 pd->pdapi_length = sizeof(struct sctp_pdapi_event);
810
811 /* pdapi_indication: 32 bits (unsigned integer)
812 *
813 * This field holds the indication being sent to the application.
814 */
815 pd->pdapi_indication = indication;
816
817 /* pdapi_assoc_id: sizeof (sctp_assoc_t)
818 *
819 * The association id field, holds the identifier for the association.
820 */
821 sctp_ulpevent_set_owner(event, asoc);
822 pd->pdapi_assoc_id = sctp_assoc2id(asoc);
823
824 return event;
825 fail:
826 return NULL;
827 }
828
sctp_ulpevent_make_authkey(const struct sctp_association * asoc,__u16 key_id,__u32 indication,gfp_t gfp)829 struct sctp_ulpevent *sctp_ulpevent_make_authkey(
830 const struct sctp_association *asoc, __u16 key_id,
831 __u32 indication, gfp_t gfp)
832 {
833 struct sctp_ulpevent *event;
834 struct sctp_authkey_event *ak;
835 struct sk_buff *skb;
836
837 event = sctp_ulpevent_new(sizeof(struct sctp_authkey_event),
838 MSG_NOTIFICATION, gfp);
839 if (!event)
840 goto fail;
841
842 skb = sctp_event2skb(event);
843 ak = (struct sctp_authkey_event *)
844 skb_put(skb, sizeof(struct sctp_authkey_event));
845
846 ak->auth_type = SCTP_AUTHENTICATION_EVENT;
847 ak->auth_flags = 0;
848 ak->auth_length = sizeof(struct sctp_authkey_event);
849
850 ak->auth_keynumber = key_id;
851 ak->auth_altkeynumber = 0;
852 ak->auth_indication = indication;
853
854 /*
855 * The association id field, holds the identifier for the association.
856 */
857 sctp_ulpevent_set_owner(event, asoc);
858 ak->auth_assoc_id = sctp_assoc2id(asoc);
859
860 return event;
861 fail:
862 return NULL;
863 }
864
865 /*
866 * Socket Extensions for SCTP
867 * 6.3.10. SCTP_SENDER_DRY_EVENT
868 */
sctp_ulpevent_make_sender_dry_event(const struct sctp_association * asoc,gfp_t gfp)869 struct sctp_ulpevent *sctp_ulpevent_make_sender_dry_event(
870 const struct sctp_association *asoc, gfp_t gfp)
871 {
872 struct sctp_ulpevent *event;
873 struct sctp_sender_dry_event *sdry;
874 struct sk_buff *skb;
875
876 event = sctp_ulpevent_new(sizeof(struct sctp_sender_dry_event),
877 MSG_NOTIFICATION, gfp);
878 if (!event)
879 return NULL;
880
881 skb = sctp_event2skb(event);
882 sdry = (struct sctp_sender_dry_event *)
883 skb_put(skb, sizeof(struct sctp_sender_dry_event));
884
885 sdry->sender_dry_type = SCTP_SENDER_DRY_EVENT;
886 sdry->sender_dry_flags = 0;
887 sdry->sender_dry_length = sizeof(struct sctp_sender_dry_event);
888 sctp_ulpevent_set_owner(event, asoc);
889 sdry->sender_dry_assoc_id = sctp_assoc2id(asoc);
890
891 return event;
892 }
893
894 /* Return the notification type, assuming this is a notification
895 * event.
896 */
sctp_ulpevent_get_notification_type(const struct sctp_ulpevent * event)897 __u16 sctp_ulpevent_get_notification_type(const struct sctp_ulpevent *event)
898 {
899 union sctp_notification *notification;
900 struct sk_buff *skb;
901
902 skb = sctp_event2skb(event);
903 notification = (union sctp_notification *) skb->data;
904 return notification->sn_header.sn_type;
905 }
906
907 /* Copy out the sndrcvinfo into a msghdr. */
sctp_ulpevent_read_sndrcvinfo(const struct sctp_ulpevent * event,struct msghdr * msghdr)908 void sctp_ulpevent_read_sndrcvinfo(const struct sctp_ulpevent *event,
909 struct msghdr *msghdr)
910 {
911 struct sctp_sndrcvinfo sinfo;
912
913 if (sctp_ulpevent_is_notification(event))
914 return;
915
916 /* Sockets API Extensions for SCTP
917 * Section 5.2.2 SCTP Header Information Structure (SCTP_SNDRCV)
918 *
919 * sinfo_stream: 16 bits (unsigned integer)
920 *
921 * For recvmsg() the SCTP stack places the message's stream number in
922 * this value.
923 */
924 sinfo.sinfo_stream = event->stream;
925 /* sinfo_ssn: 16 bits (unsigned integer)
926 *
927 * For recvmsg() this value contains the stream sequence number that
928 * the remote endpoint placed in the DATA chunk. For fragmented
929 * messages this is the same number for all deliveries of the message
930 * (if more than one recvmsg() is needed to read the message).
931 */
932 sinfo.sinfo_ssn = event->ssn;
933 /* sinfo_ppid: 32 bits (unsigned integer)
934 *
935 * In recvmsg() this value is
936 * the same information that was passed by the upper layer in the peer
937 * application. Please note that byte order issues are NOT accounted
938 * for and this information is passed opaquely by the SCTP stack from
939 * one end to the other.
940 */
941 sinfo.sinfo_ppid = event->ppid;
942 /* sinfo_flags: 16 bits (unsigned integer)
943 *
944 * This field may contain any of the following flags and is composed of
945 * a bitwise OR of these values.
946 *
947 * recvmsg() flags:
948 *
949 * SCTP_UNORDERED - This flag is present when the message was sent
950 * non-ordered.
951 */
952 sinfo.sinfo_flags = event->flags;
953 /* sinfo_tsn: 32 bit (unsigned integer)
954 *
955 * For the receiving side, this field holds a TSN that was
956 * assigned to one of the SCTP Data Chunks.
957 */
958 sinfo.sinfo_tsn = event->tsn;
959 /* sinfo_cumtsn: 32 bit (unsigned integer)
960 *
961 * This field will hold the current cumulative TSN as
962 * known by the underlying SCTP layer. Note this field is
963 * ignored when sending and only valid for a receive
964 * operation when sinfo_flags are set to SCTP_UNORDERED.
965 */
966 sinfo.sinfo_cumtsn = event->cumtsn;
967 /* sinfo_assoc_id: sizeof (sctp_assoc_t)
968 *
969 * The association handle field, sinfo_assoc_id, holds the identifier
970 * for the association announced in the COMMUNICATION_UP notification.
971 * All notifications for a given association have the same identifier.
972 * Ignored for one-to-one style sockets.
973 */
974 sinfo.sinfo_assoc_id = sctp_assoc2id(event->asoc);
975
976 /* context value that is set via SCTP_CONTEXT socket option. */
977 sinfo.sinfo_context = event->asoc->default_rcv_context;
978
979 /* These fields are not used while receiving. */
980 sinfo.sinfo_timetolive = 0;
981
982 put_cmsg(msghdr, IPPROTO_SCTP, SCTP_SNDRCV,
983 sizeof(struct sctp_sndrcvinfo), (void *)&sinfo);
984 }
985
986 /* Do accounting for bytes received and hold a reference to the association
987 * for each skb.
988 */
sctp_ulpevent_receive_data(struct sctp_ulpevent * event,struct sctp_association * asoc)989 static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
990 struct sctp_association *asoc)
991 {
992 struct sk_buff *skb, *frag;
993
994 skb = sctp_event2skb(event);
995 /* Set the owner and charge rwnd for bytes received. */
996 sctp_ulpevent_set_owner(event, asoc);
997 sctp_assoc_rwnd_decrease(asoc, skb_headlen(skb));
998
999 if (!skb->data_len)
1000 return;
1001
1002 /* Note: Not clearing the entire event struct as this is just a
1003 * fragment of the real event. However, we still need to do rwnd
1004 * accounting.
1005 * In general, the skb passed from IP can have only 1 level of
1006 * fragments. But we allow multiple levels of fragments.
1007 */
1008 skb_walk_frags(skb, frag)
1009 sctp_ulpevent_receive_data(sctp_skb2event(frag), asoc);
1010 }
1011
1012 /* Do accounting for bytes just read by user and release the references to
1013 * the association.
1014 */
sctp_ulpevent_release_data(struct sctp_ulpevent * event)1015 static void sctp_ulpevent_release_data(struct sctp_ulpevent *event)
1016 {
1017 struct sk_buff *skb, *frag;
1018 unsigned int len;
1019
1020 /* Current stack structures assume that the rcv buffer is
1021 * per socket. For UDP style sockets this is not true as
1022 * multiple associations may be on a single UDP-style socket.
1023 * Use the local private area of the skb to track the owning
1024 * association.
1025 */
1026
1027 skb = sctp_event2skb(event);
1028 len = skb->len;
1029
1030 if (!skb->data_len)
1031 goto done;
1032
1033 /* Don't forget the fragments. */
1034 skb_walk_frags(skb, frag) {
1035 /* NOTE: skb_shinfos are recursive. Although IP returns
1036 * skb's with only 1 level of fragments, SCTP reassembly can
1037 * increase the levels.
1038 */
1039 sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
1040 }
1041
1042 done:
1043 sctp_assoc_rwnd_increase(event->asoc, len);
1044 sctp_ulpevent_release_owner(event);
1045 }
1046
sctp_ulpevent_release_frag_data(struct sctp_ulpevent * event)1047 static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event)
1048 {
1049 struct sk_buff *skb, *frag;
1050
1051 skb = sctp_event2skb(event);
1052
1053 if (!skb->data_len)
1054 goto done;
1055
1056 /* Don't forget the fragments. */
1057 skb_walk_frags(skb, frag) {
1058 /* NOTE: skb_shinfos are recursive. Although IP returns
1059 * skb's with only 1 level of fragments, SCTP reassembly can
1060 * increase the levels.
1061 */
1062 sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
1063 }
1064
1065 done:
1066 sctp_ulpevent_release_owner(event);
1067 }
1068
1069 /* Free a ulpevent that has an owner. It includes releasing the reference
1070 * to the owner, updating the rwnd in case of a DATA event and freeing the
1071 * skb.
1072 */
sctp_ulpevent_free(struct sctp_ulpevent * event)1073 void sctp_ulpevent_free(struct sctp_ulpevent *event)
1074 {
1075 if (sctp_ulpevent_is_notification(event))
1076 sctp_ulpevent_release_owner(event);
1077 else
1078 sctp_ulpevent_release_data(event);
1079
1080 kfree_skb(sctp_event2skb(event));
1081 }
1082
1083 /* Purge the skb lists holding ulpevents. */
sctp_queue_purge_ulpevents(struct sk_buff_head * list)1084 unsigned int sctp_queue_purge_ulpevents(struct sk_buff_head *list)
1085 {
1086 struct sk_buff *skb;
1087 unsigned int data_unread = 0;
1088
1089 while ((skb = skb_dequeue(list)) != NULL) {
1090 struct sctp_ulpevent *event = sctp_skb2event(skb);
1091
1092 if (!sctp_ulpevent_is_notification(event))
1093 data_unread += skb->len;
1094
1095 sctp_ulpevent_free(event);
1096 }
1097
1098 return data_unread;
1099 }
1100