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Linux/net/sctp/ulpevent.c

Version: ~ [ linux-5.13-rc7 ] ~ [ linux-5.12.12 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.45 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.127 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.195 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.237 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.273 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.273 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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  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, see
 26  * <http://www.gnu.org/licenses/>.
 27  *
 28  * Please send any bug reports or fixes you make to the
 29  * email address(es):
 30  *    lksctp developers <linux-sctp@vger.kernel.org>
 31  *
 32  * Written or modified by:
 33  *    Jon Grimm             <jgrimm@us.ibm.com>
 34  *    La Monte H.P. Yarroll <piggy@acm.org>
 35  *    Ardelle Fan           <ardelle.fan@intel.com>
 36  *    Sridhar Samudrala     <sri@us.ibm.com>
 37  */
 38 
 39 #include <linux/slab.h>
 40 #include <linux/types.h>
 41 #include <linux/skbuff.h>
 42 #include <net/sctp/structs.h>
 43 #include <net/sctp/sctp.h>
 44 #include <net/sctp/sm.h>
 45 
 46 static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
 47                                        struct sctp_association *asoc);
 48 static void sctp_ulpevent_release_data(struct sctp_ulpevent *event);
 49 static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event);
 50 
 51 
 52 /* Initialize an ULP event from an given skb.  */
 53 static void sctp_ulpevent_init(struct sctp_ulpevent *event,
 54                                int msg_flags,
 55                                unsigned int len)
 56 {
 57         memset(event, 0, sizeof(struct sctp_ulpevent));
 58         event->msg_flags = msg_flags;
 59         event->rmem_len = len;
 60 }
 61 
 62 /* Create a new sctp_ulpevent.  */
 63 static struct sctp_ulpevent *sctp_ulpevent_new(int size, int msg_flags,
 64                                                gfp_t gfp)
 65 {
 66         struct sctp_ulpevent *event;
 67         struct sk_buff *skb;
 68 
 69         skb = alloc_skb(size, gfp);
 70         if (!skb)
 71                 goto fail;
 72 
 73         event = sctp_skb2event(skb);
 74         sctp_ulpevent_init(event, msg_flags, skb->truesize);
 75 
 76         return event;
 77 
 78 fail:
 79         return NULL;
 80 }
 81 
 82 /* Is this a MSG_NOTIFICATION?  */
 83 int sctp_ulpevent_is_notification(const struct sctp_ulpevent *event)
 84 {
 85         return MSG_NOTIFICATION == (event->msg_flags & MSG_NOTIFICATION);
 86 }
 87 
 88 /* Hold the association in case the msg_name needs read out of
 89  * the association.
 90  */
 91 static inline void sctp_ulpevent_set_owner(struct sctp_ulpevent *event,
 92                                            const struct sctp_association *asoc)
 93 {
 94         struct sk_buff *skb;
 95 
 96         /* Cast away the const, as we are just wanting to
 97          * bump the reference count.
 98          */
 99         sctp_association_hold((struct sctp_association *)asoc);
100         skb = sctp_event2skb(event);
101         event->asoc = (struct sctp_association *)asoc;
102         atomic_add(event->rmem_len, &event->asoc->rmem_alloc);
103         sctp_skb_set_owner_r(skb, asoc->base.sk);
104 }
105 
106 /* A simple destructor to give up the reference to the association. */
107 static inline void sctp_ulpevent_release_owner(struct sctp_ulpevent *event)
108 {
109         struct sctp_association *asoc = event->asoc;
110 
111         atomic_sub(event->rmem_len, &asoc->rmem_alloc);
112         sctp_association_put(asoc);
113 }
114 
115 /* Create and initialize an SCTP_ASSOC_CHANGE event.
116  *
117  * 5.3.1.1 SCTP_ASSOC_CHANGE
118  *
119  * Communication notifications inform the ULP that an SCTP association
120  * has either begun or ended. The identifier for a new association is
121  * provided by this notification.
122  *
123  * Note: There is no field checking here.  If a field is unused it will be
124  * zero'd out.
125  */
126 struct sctp_ulpevent  *sctp_ulpevent_make_assoc_change(
127         const struct sctp_association *asoc,
128         __u16 flags, __u16 state, __u16 error, __u16 outbound,
129         __u16 inbound, struct sctp_chunk *chunk, gfp_t gfp)
130 {
131         struct sctp_ulpevent *event;
132         struct sctp_assoc_change *sac;
133         struct sk_buff *skb;
134 
135         /* If the lower layer passed in the chunk, it will be
136          * an ABORT, so we need to include it in the sac_info.
137          */
138         if (chunk) {
139                 /* Copy the chunk data to a new skb and reserve enough
140                  * head room to use as notification.
141                  */
142                 skb = skb_copy_expand(chunk->skb,
143                                       sizeof(struct sctp_assoc_change), 0, gfp);
144 
145                 if (!skb)
146                         goto fail;
147 
148                 /* Embed the event fields inside the cloned skb.  */
149                 event = sctp_skb2event(skb);
150                 sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
151 
152                 /* Include the notification structure */
153                 sac = (struct sctp_assoc_change *)
154                         skb_push(skb, sizeof(struct sctp_assoc_change));
155 
156                 /* Trim the buffer to the right length.  */
157                 skb_trim(skb, sizeof(struct sctp_assoc_change) +
158                          ntohs(chunk->chunk_hdr->length) -
159                          sizeof(sctp_chunkhdr_t));
160         } else {
161                 event = sctp_ulpevent_new(sizeof(struct sctp_assoc_change),
162                                   MSG_NOTIFICATION, gfp);
163                 if (!event)
164                         goto fail;
165 
166                 skb = sctp_event2skb(event);
167                 sac = (struct sctp_assoc_change *) skb_put(skb,
168                                         sizeof(struct sctp_assoc_change));
169         }
170 
171         /* Socket Extensions for SCTP
172          * 5.3.1.1 SCTP_ASSOC_CHANGE
173          *
174          * sac_type:
175          * It should be SCTP_ASSOC_CHANGE.
176          */
177         sac->sac_type = SCTP_ASSOC_CHANGE;
178 
179         /* Socket Extensions for SCTP
180          * 5.3.1.1 SCTP_ASSOC_CHANGE
181          *
182          * sac_state: 32 bits (signed integer)
183          * This field holds one of a number of values that communicate the
184          * event that happened to the association.
185          */
186         sac->sac_state = state;
187 
188         /* Socket Extensions for SCTP
189          * 5.3.1.1 SCTP_ASSOC_CHANGE
190          *
191          * sac_flags: 16 bits (unsigned integer)
192          * Currently unused.
193          */
194         sac->sac_flags = 0;
195 
196         /* Socket Extensions for SCTP
197          * 5.3.1.1 SCTP_ASSOC_CHANGE
198          *
199          * sac_length: sizeof (__u32)
200          * This field is the total length of the notification data, including
201          * the notification header.
202          */
203         sac->sac_length = skb->len;
204 
205         /* Socket Extensions for SCTP
206          * 5.3.1.1 SCTP_ASSOC_CHANGE
207          *
208          * sac_error:  32 bits (signed integer)
209          *
210          * If the state was reached due to a error condition (e.g.
211          * COMMUNICATION_LOST) any relevant error information is available in
212          * this field. This corresponds to the protocol error codes defined in
213          * [SCTP].
214          */
215         sac->sac_error = error;
216 
217         /* Socket Extensions for SCTP
218          * 5.3.1.1 SCTP_ASSOC_CHANGE
219          *
220          * sac_outbound_streams:  16 bits (unsigned integer)
221          * sac_inbound_streams:  16 bits (unsigned integer)
222          *
223          * The maximum number of streams allowed in each direction are
224          * available in sac_outbound_streams and sac_inbound streams.
225          */
226         sac->sac_outbound_streams = outbound;
227         sac->sac_inbound_streams = inbound;
228 
229         /* Socket Extensions for SCTP
230          * 5.3.1.1 SCTP_ASSOC_CHANGE
231          *
232          * sac_assoc_id: sizeof (sctp_assoc_t)
233          *
234          * The association id field, holds the identifier for the association.
235          * All notifications for a given association have the same association
236          * identifier.  For TCP style socket, this field is ignored.
237          */
238         sctp_ulpevent_set_owner(event, asoc);
239         sac->sac_assoc_id = sctp_assoc2id(asoc);
240 
241         return event;
242 
243 fail:
244         return NULL;
245 }
246 
247 /* Create and initialize an SCTP_PEER_ADDR_CHANGE event.
248  *
249  * Socket Extensions for SCTP - draft-01
250  * 5.3.1.2 SCTP_PEER_ADDR_CHANGE
251  *
252  * When a destination address on a multi-homed peer encounters a change
253  * an interface details event is sent.
254  */
255 struct sctp_ulpevent *sctp_ulpevent_make_peer_addr_change(
256         const struct sctp_association *asoc,
257         const struct sockaddr_storage *aaddr,
258         int flags, int state, int error, gfp_t gfp)
259 {
260         struct sctp_ulpevent *event;
261         struct sctp_paddr_change  *spc;
262         struct sk_buff *skb;
263 
264         event = sctp_ulpevent_new(sizeof(struct sctp_paddr_change),
265                                   MSG_NOTIFICATION, gfp);
266         if (!event)
267                 goto fail;
268 
269         skb = sctp_event2skb(event);
270         spc = (struct sctp_paddr_change *)
271                 skb_put(skb, sizeof(struct sctp_paddr_change));
272 
273         /* Sockets API Extensions for SCTP
274          * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
275          *
276          * spc_type:
277          *
278          *    It should be SCTP_PEER_ADDR_CHANGE.
279          */
280         spc->spc_type = SCTP_PEER_ADDR_CHANGE;
281 
282         /* Sockets API Extensions for SCTP
283          * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
284          *
285          * spc_length: sizeof (__u32)
286          *
287          * This field is the total length of the notification data, including
288          * the notification header.
289          */
290         spc->spc_length = sizeof(struct sctp_paddr_change);
291 
292         /* Sockets API Extensions for SCTP
293          * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
294          *
295          * spc_flags: 16 bits (unsigned integer)
296          * Currently unused.
297          */
298         spc->spc_flags = 0;
299 
300         /* Sockets API Extensions for SCTP
301          * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
302          *
303          * spc_state:  32 bits (signed integer)
304          *
305          * This field holds one of a number of values that communicate the
306          * event that happened to the address.
307          */
308         spc->spc_state = state;
309 
310         /* Sockets API Extensions for SCTP
311          * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
312          *
313          * spc_error:  32 bits (signed integer)
314          *
315          * If the state was reached due to any error condition (e.g.
316          * ADDRESS_UNREACHABLE) any relevant error information is available in
317          * this field.
318          */
319         spc->spc_error = error;
320 
321         /* Socket Extensions for SCTP
322          * 5.3.1.1 SCTP_ASSOC_CHANGE
323          *
324          * spc_assoc_id: sizeof (sctp_assoc_t)
325          *
326          * The association id field, holds the identifier for the association.
327          * All notifications for a given association have the same association
328          * identifier.  For TCP style socket, this field is ignored.
329          */
330         sctp_ulpevent_set_owner(event, asoc);
331         spc->spc_assoc_id = sctp_assoc2id(asoc);
332 
333         /* Sockets API Extensions for SCTP
334          * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
335          *
336          * spc_aaddr: sizeof (struct sockaddr_storage)
337          *
338          * The affected address field, holds the remote peer's address that is
339          * encountering the change of state.
340          */
341         memcpy(&spc->spc_aaddr, aaddr, sizeof(struct sockaddr_storage));
342 
343         /* Map ipv4 address into v4-mapped-on-v6 address.  */
344         sctp_get_pf_specific(asoc->base.sk->sk_family)->addr_to_user(
345                                         sctp_sk(asoc->base.sk),
346                                         (union sctp_addr *)&spc->spc_aaddr);
347 
348         return event;
349 
350 fail:
351         return NULL;
352 }
353 
354 /* Create and initialize an SCTP_REMOTE_ERROR notification.
355  *
356  * Note: This assumes that the chunk->skb->data already points to the
357  * operation error payload.
358  *
359  * Socket Extensions for SCTP - draft-01
360  * 5.3.1.3 SCTP_REMOTE_ERROR
361  *
362  * A remote peer may send an Operational Error message to its peer.
363  * This message indicates a variety of error conditions on an
364  * association. The entire error TLV as it appears on the wire is
365  * included in a SCTP_REMOTE_ERROR event.  Please refer to the SCTP
366  * specification [SCTP] and any extensions for a list of possible
367  * error formats.
368  */
369 struct sctp_ulpevent *
370 sctp_ulpevent_make_remote_error(const struct sctp_association *asoc,
371                                 struct sctp_chunk *chunk, __u16 flags,
372                                 gfp_t gfp)
373 {
374         struct sctp_ulpevent *event;
375         struct sctp_remote_error *sre;
376         struct sk_buff *skb;
377         sctp_errhdr_t *ch;
378         __be16 cause;
379         int elen;
380 
381         ch = (sctp_errhdr_t *)(chunk->skb->data);
382         cause = ch->cause;
383         elen = WORD_ROUND(ntohs(ch->length)) - sizeof(sctp_errhdr_t);
384 
385         /* Pull off the ERROR header.  */
386         skb_pull(chunk->skb, sizeof(sctp_errhdr_t));
387 
388         /* Copy the skb to a new skb with room for us to prepend
389          * notification with.
390          */
391         skb = skb_copy_expand(chunk->skb, sizeof(*sre), 0, gfp);
392 
393         /* Pull off the rest of the cause TLV from the chunk.  */
394         skb_pull(chunk->skb, elen);
395         if (!skb)
396                 goto fail;
397 
398         /* Embed the event fields inside the cloned skb.  */
399         event = sctp_skb2event(skb);
400         sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
401 
402         sre = (struct sctp_remote_error *) skb_push(skb, sizeof(*sre));
403 
404         /* Trim the buffer to the right length.  */
405         skb_trim(skb, sizeof(*sre) + elen);
406 
407         /* RFC6458, Section 6.1.3. SCTP_REMOTE_ERROR */
408         memset(sre, 0, sizeof(*sre));
409         sre->sre_type = SCTP_REMOTE_ERROR;
410         sre->sre_flags = 0;
411         sre->sre_length = skb->len;
412         sre->sre_error = cause;
413         sctp_ulpevent_set_owner(event, asoc);
414         sre->sre_assoc_id = sctp_assoc2id(asoc);
415 
416         return event;
417 fail:
418         return NULL;
419 }
420 
421 /* Create and initialize a SCTP_SEND_FAILED notification.
422  *
423  * Socket Extensions for SCTP - draft-01
424  * 5.3.1.4 SCTP_SEND_FAILED
425  */
426 struct sctp_ulpevent *sctp_ulpevent_make_send_failed(
427         const struct sctp_association *asoc, struct sctp_chunk *chunk,
428         __u16 flags, __u32 error, gfp_t gfp)
429 {
430         struct sctp_ulpevent *event;
431         struct sctp_send_failed *ssf;
432         struct sk_buff *skb;
433 
434         /* Pull off any padding. */
435         int len = ntohs(chunk->chunk_hdr->length);
436 
437         /* Make skb with more room so we can prepend notification.  */
438         skb = skb_copy_expand(chunk->skb,
439                               sizeof(struct sctp_send_failed), /* headroom */
440                               0,                               /* tailroom */
441                               gfp);
442         if (!skb)
443                 goto fail;
444 
445         /* Pull off the common chunk header and DATA header.  */
446         skb_pull(skb, sizeof(struct sctp_data_chunk));
447         len -= sizeof(struct sctp_data_chunk);
448 
449         /* Embed the event fields inside the cloned skb.  */
450         event = sctp_skb2event(skb);
451         sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
452 
453         ssf = (struct sctp_send_failed *)
454                 skb_push(skb, sizeof(struct sctp_send_failed));
455 
456         /* Socket Extensions for SCTP
457          * 5.3.1.4 SCTP_SEND_FAILED
458          *
459          * ssf_type:
460          * It should be SCTP_SEND_FAILED.
461          */
462         ssf->ssf_type = SCTP_SEND_FAILED;
463 
464         /* Socket Extensions for SCTP
465          * 5.3.1.4 SCTP_SEND_FAILED
466          *
467          * ssf_flags: 16 bits (unsigned integer)
468          * The flag value will take one of the following values
469          *
470          * SCTP_DATA_UNSENT - Indicates that the data was never put on
471          *                    the wire.
472          *
473          * SCTP_DATA_SENT   - Indicates that the data was put on the wire.
474          *                    Note that this does not necessarily mean that the
475          *                    data was (or was not) successfully delivered.
476          */
477         ssf->ssf_flags = flags;
478 
479         /* Socket Extensions for SCTP
480          * 5.3.1.4 SCTP_SEND_FAILED
481          *
482          * ssf_length: sizeof (__u32)
483          * This field is the total length of the notification data, including
484          * the notification header.
485          */
486         ssf->ssf_length = sizeof(struct sctp_send_failed) + len;
487         skb_trim(skb, ssf->ssf_length);
488 
489         /* Socket Extensions for SCTP
490          * 5.3.1.4 SCTP_SEND_FAILED
491          *
492          * ssf_error: 16 bits (unsigned integer)
493          * This value represents the reason why the send failed, and if set,
494          * will be a SCTP protocol error code as defined in [SCTP] section
495          * 3.3.10.
496          */
497         ssf->ssf_error = error;
498 
499         /* Socket Extensions for SCTP
500          * 5.3.1.4 SCTP_SEND_FAILED
501          *
502          * ssf_info: sizeof (struct sctp_sndrcvinfo)
503          * The original send information associated with the undelivered
504          * message.
505          */
506         memcpy(&ssf->ssf_info, &chunk->sinfo, sizeof(struct sctp_sndrcvinfo));
507 
508         /* Per TSVWG discussion with Randy. Allow the application to
509          * reassemble a fragmented message.
510          */
511         ssf->ssf_info.sinfo_flags = chunk->chunk_hdr->flags;
512 
513         /* Socket Extensions for SCTP
514          * 5.3.1.4 SCTP_SEND_FAILED
515          *
516          * ssf_assoc_id: sizeof (sctp_assoc_t)
517          * The association id field, sf_assoc_id, holds the identifier for the
518          * association.  All notifications for a given association have the
519          * same association identifier.  For TCP style socket, this field is
520          * ignored.
521          */
522         sctp_ulpevent_set_owner(event, asoc);
523         ssf->ssf_assoc_id = sctp_assoc2id(asoc);
524         return event;
525 
526 fail:
527         return NULL;
528 }
529 
530 /* Create and initialize a SCTP_SHUTDOWN_EVENT notification.
531  *
532  * Socket Extensions for SCTP - draft-01
533  * 5.3.1.5 SCTP_SHUTDOWN_EVENT
534  */
535 struct sctp_ulpevent *sctp_ulpevent_make_shutdown_event(
536         const struct sctp_association *asoc,
537         __u16 flags, gfp_t gfp)
538 {
539         struct sctp_ulpevent *event;
540         struct sctp_shutdown_event *sse;
541         struct sk_buff *skb;
542 
543         event = sctp_ulpevent_new(sizeof(struct sctp_shutdown_event),
544                                   MSG_NOTIFICATION, gfp);
545         if (!event)
546                 goto fail;
547 
548         skb = sctp_event2skb(event);
549         sse = (struct sctp_shutdown_event *)
550                 skb_put(skb, sizeof(struct sctp_shutdown_event));
551 
552         /* Socket Extensions for SCTP
553          * 5.3.1.5 SCTP_SHUTDOWN_EVENT
554          *
555          * sse_type
556          * It should be SCTP_SHUTDOWN_EVENT
557          */
558         sse->sse_type = SCTP_SHUTDOWN_EVENT;
559 
560         /* Socket Extensions for SCTP
561          * 5.3.1.5 SCTP_SHUTDOWN_EVENT
562          *
563          * sse_flags: 16 bits (unsigned integer)
564          * Currently unused.
565          */
566         sse->sse_flags = 0;
567 
568         /* Socket Extensions for SCTP
569          * 5.3.1.5 SCTP_SHUTDOWN_EVENT
570          *
571          * sse_length: sizeof (__u32)
572          * This field is the total length of the notification data, including
573          * the notification header.
574          */
575         sse->sse_length = sizeof(struct sctp_shutdown_event);
576 
577         /* Socket Extensions for SCTP
578          * 5.3.1.5 SCTP_SHUTDOWN_EVENT
579          *
580          * sse_assoc_id: sizeof (sctp_assoc_t)
581          * The association id field, holds the identifier for the association.
582          * All notifications for a given association have the same association
583          * identifier.  For TCP style socket, this field is ignored.
584          */
585         sctp_ulpevent_set_owner(event, asoc);
586         sse->sse_assoc_id = sctp_assoc2id(asoc);
587 
588         return event;
589 
590 fail:
591         return NULL;
592 }
593 
594 /* Create and initialize a SCTP_ADAPTATION_INDICATION notification.
595  *
596  * Socket Extensions for SCTP
597  * 5.3.1.6 SCTP_ADAPTATION_INDICATION
598  */
599 struct sctp_ulpevent *sctp_ulpevent_make_adaptation_indication(
600         const struct sctp_association *asoc, gfp_t gfp)
601 {
602         struct sctp_ulpevent *event;
603         struct sctp_adaptation_event *sai;
604         struct sk_buff *skb;
605 
606         event = sctp_ulpevent_new(sizeof(struct sctp_adaptation_event),
607                                   MSG_NOTIFICATION, gfp);
608         if (!event)
609                 goto fail;
610 
611         skb = sctp_event2skb(event);
612         sai = (struct sctp_adaptation_event *)
613                 skb_put(skb, sizeof(struct sctp_adaptation_event));
614 
615         sai->sai_type = SCTP_ADAPTATION_INDICATION;
616         sai->sai_flags = 0;
617         sai->sai_length = sizeof(struct sctp_adaptation_event);
618         sai->sai_adaptation_ind = asoc->peer.adaptation_ind;
619         sctp_ulpevent_set_owner(event, asoc);
620         sai->sai_assoc_id = sctp_assoc2id(asoc);
621 
622         return event;
623 
624 fail:
625         return NULL;
626 }
627 
628 /* A message has been received.  Package this message as a notification
629  * to pass it to the upper layers.  Go ahead and calculate the sndrcvinfo
630  * even if filtered out later.
631  *
632  * Socket Extensions for SCTP
633  * 5.2.2 SCTP Header Information Structure (SCTP_SNDRCV)
634  */
635 struct sctp_ulpevent *sctp_ulpevent_make_rcvmsg(struct sctp_association *asoc,
636                                                 struct sctp_chunk *chunk,
637                                                 gfp_t gfp)
638 {
639         struct sctp_ulpevent *event = NULL;
640         struct sk_buff *skb;
641         size_t padding, len;
642         int rx_count;
643 
644         /*
645          * check to see if we need to make space for this
646          * new skb, expand the rcvbuffer if needed, or drop
647          * the frame
648          */
649         if (asoc->ep->rcvbuf_policy)
650                 rx_count = atomic_read(&asoc->rmem_alloc);
651         else
652                 rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);
653 
654         if (rx_count >= asoc->base.sk->sk_rcvbuf) {
655 
656                 if ((asoc->base.sk->sk_userlocks & SOCK_RCVBUF_LOCK) ||
657                     (!sk_rmem_schedule(asoc->base.sk, chunk->skb,
658                                        chunk->skb->truesize)))
659                         goto fail;
660         }
661 
662         /* Clone the original skb, sharing the data.  */
663         skb = skb_clone(chunk->skb, gfp);
664         if (!skb)
665                 goto fail;
666 
667         /* Now that all memory allocations for this chunk succeeded, we
668          * can mark it as received so the tsn_map is updated correctly.
669          */
670         if (sctp_tsnmap_mark(&asoc->peer.tsn_map,
671                              ntohl(chunk->subh.data_hdr->tsn),
672                              chunk->transport))
673                 goto fail_mark;
674 
675         /* First calculate the padding, so we don't inadvertently
676          * pass up the wrong length to the user.
677          *
678          * RFC 2960 - Section 3.2  Chunk Field Descriptions
679          *
680          * The total length of a chunk(including Type, Length and Value fields)
681          * MUST be a multiple of 4 bytes.  If the length of the chunk is not a
682          * multiple of 4 bytes, the sender MUST pad the chunk with all zero
683          * bytes and this padding is not included in the chunk length field.
684          * The sender should never pad with more than 3 bytes.  The receiver
685          * MUST ignore the padding bytes.
686          */
687         len = ntohs(chunk->chunk_hdr->length);
688         padding = WORD_ROUND(len) - len;
689 
690         /* Fixup cloned skb with just this chunks data.  */
691         skb_trim(skb, chunk->chunk_end - padding - skb->data);
692 
693         /* Embed the event fields inside the cloned skb.  */
694         event = sctp_skb2event(skb);
695 
696         /* Initialize event with flags 0  and correct length
697          * Since this is a clone of the original skb, only account for
698          * the data of this chunk as other chunks will be accounted separately.
699          */
700         sctp_ulpevent_init(event, 0, skb->len + sizeof(struct sk_buff));
701 
702         sctp_ulpevent_receive_data(event, asoc);
703 
704         event->stream = ntohs(chunk->subh.data_hdr->stream);
705         event->ssn = ntohs(chunk->subh.data_hdr->ssn);
706         event->ppid = chunk->subh.data_hdr->ppid;
707         if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
708                 event->flags |= SCTP_UNORDERED;
709                 event->cumtsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
710         }
711         event->tsn = ntohl(chunk->subh.data_hdr->tsn);
712         event->msg_flags |= chunk->chunk_hdr->flags;
713         event->iif = sctp_chunk_iif(chunk);
714 
715         return event;
716 
717 fail_mark:
718         kfree_skb(skb);
719 fail:
720         return NULL;
721 }
722 
723 /* Create a partial delivery related event.
724  *
725  * 5.3.1.7 SCTP_PARTIAL_DELIVERY_EVENT
726  *
727  *   When a receiver is engaged in a partial delivery of a
728  *   message this notification will be used to indicate
729  *   various events.
730  */
731 struct sctp_ulpevent *sctp_ulpevent_make_pdapi(
732         const struct sctp_association *asoc, __u32 indication,
733         gfp_t gfp)
734 {
735         struct sctp_ulpevent *event;
736         struct sctp_pdapi_event *pd;
737         struct sk_buff *skb;
738 
739         event = sctp_ulpevent_new(sizeof(struct sctp_pdapi_event),
740                                   MSG_NOTIFICATION, gfp);
741         if (!event)
742                 goto fail;
743 
744         skb = sctp_event2skb(event);
745         pd = (struct sctp_pdapi_event *)
746                 skb_put(skb, sizeof(struct sctp_pdapi_event));
747 
748         /* pdapi_type
749          *   It should be SCTP_PARTIAL_DELIVERY_EVENT
750          *
751          * pdapi_flags: 16 bits (unsigned integer)
752          *   Currently unused.
753          */
754         pd->pdapi_type = SCTP_PARTIAL_DELIVERY_EVENT;
755         pd->pdapi_flags = 0;
756 
757         /* pdapi_length: 32 bits (unsigned integer)
758          *
759          * This field is the total length of the notification data, including
760          * the notification header.  It will generally be sizeof (struct
761          * sctp_pdapi_event).
762          */
763         pd->pdapi_length = sizeof(struct sctp_pdapi_event);
764 
765         /*  pdapi_indication: 32 bits (unsigned integer)
766          *
767          * This field holds the indication being sent to the application.
768          */
769         pd->pdapi_indication = indication;
770 
771         /*  pdapi_assoc_id: sizeof (sctp_assoc_t)
772          *
773          * The association id field, holds the identifier for the association.
774          */
775         sctp_ulpevent_set_owner(event, asoc);
776         pd->pdapi_assoc_id = sctp_assoc2id(asoc);
777 
778         return event;
779 fail:
780         return NULL;
781 }
782 
783 struct sctp_ulpevent *sctp_ulpevent_make_authkey(
784         const struct sctp_association *asoc, __u16 key_id,
785         __u32 indication, gfp_t gfp)
786 {
787         struct sctp_ulpevent *event;
788         struct sctp_authkey_event *ak;
789         struct sk_buff *skb;
790 
791         event = sctp_ulpevent_new(sizeof(struct sctp_authkey_event),
792                                   MSG_NOTIFICATION, gfp);
793         if (!event)
794                 goto fail;
795 
796         skb = sctp_event2skb(event);
797         ak = (struct sctp_authkey_event *)
798                 skb_put(skb, sizeof(struct sctp_authkey_event));
799 
800         ak->auth_type = SCTP_AUTHENTICATION_EVENT;
801         ak->auth_flags = 0;
802         ak->auth_length = sizeof(struct sctp_authkey_event);
803 
804         ak->auth_keynumber = key_id;
805         ak->auth_altkeynumber = 0;
806         ak->auth_indication = indication;
807 
808         /*
809          * The association id field, holds the identifier for the association.
810          */
811         sctp_ulpevent_set_owner(event, asoc);
812         ak->auth_assoc_id = sctp_assoc2id(asoc);
813 
814         return event;
815 fail:
816         return NULL;
817 }
818 
819 /*
820  * Socket Extensions for SCTP
821  * 6.3.10. SCTP_SENDER_DRY_EVENT
822  */
823 struct sctp_ulpevent *sctp_ulpevent_make_sender_dry_event(
824         const struct sctp_association *asoc, gfp_t gfp)
825 {
826         struct sctp_ulpevent *event;
827         struct sctp_sender_dry_event *sdry;
828         struct sk_buff *skb;
829 
830         event = sctp_ulpevent_new(sizeof(struct sctp_sender_dry_event),
831                                   MSG_NOTIFICATION, gfp);
832         if (!event)
833                 return NULL;
834 
835         skb = sctp_event2skb(event);
836         sdry = (struct sctp_sender_dry_event *)
837                 skb_put(skb, sizeof(struct sctp_sender_dry_event));
838 
839         sdry->sender_dry_type = SCTP_SENDER_DRY_EVENT;
840         sdry->sender_dry_flags = 0;
841         sdry->sender_dry_length = sizeof(struct sctp_sender_dry_event);
842         sctp_ulpevent_set_owner(event, asoc);
843         sdry->sender_dry_assoc_id = sctp_assoc2id(asoc);
844 
845         return event;
846 }
847 
848 /* Return the notification type, assuming this is a notification
849  * event.
850  */
851 __u16 sctp_ulpevent_get_notification_type(const struct sctp_ulpevent *event)
852 {
853         union sctp_notification *notification;
854         struct sk_buff *skb;
855 
856         skb = sctp_event2skb(event);
857         notification = (union sctp_notification *) skb->data;
858         return notification->sn_header.sn_type;
859 }
860 
861 /* RFC6458, Section 5.3.2. SCTP Header Information Structure
862  * (SCTP_SNDRCV, DEPRECATED)
863  */
864 void sctp_ulpevent_read_sndrcvinfo(const struct sctp_ulpevent *event,
865                                    struct msghdr *msghdr)
866 {
867         struct sctp_sndrcvinfo sinfo;
868 
869         if (sctp_ulpevent_is_notification(event))
870                 return;
871 
872         memset(&sinfo, 0, sizeof(sinfo));
873         sinfo.sinfo_stream = event->stream;
874         sinfo.sinfo_ssn = event->ssn;
875         sinfo.sinfo_ppid = event->ppid;
876         sinfo.sinfo_flags = event->flags;
877         sinfo.sinfo_tsn = event->tsn;
878         sinfo.sinfo_cumtsn = event->cumtsn;
879         sinfo.sinfo_assoc_id = sctp_assoc2id(event->asoc);
880         /* Context value that is set via SCTP_CONTEXT socket option. */
881         sinfo.sinfo_context = event->asoc->default_rcv_context;
882         /* These fields are not used while receiving. */
883         sinfo.sinfo_timetolive = 0;
884 
885         put_cmsg(msghdr, IPPROTO_SCTP, SCTP_SNDRCV,
886                  sizeof(sinfo), &sinfo);
887 }
888 
889 /* RFC6458, Section 5.3.5 SCTP Receive Information Structure
890  * (SCTP_SNDRCV)
891  */
892 void sctp_ulpevent_read_rcvinfo(const struct sctp_ulpevent *event,
893                                 struct msghdr *msghdr)
894 {
895         struct sctp_rcvinfo rinfo;
896 
897         if (sctp_ulpevent_is_notification(event))
898                 return;
899 
900         memset(&rinfo, 0, sizeof(struct sctp_rcvinfo));
901         rinfo.rcv_sid = event->stream;
902         rinfo.rcv_ssn = event->ssn;
903         rinfo.rcv_ppid = event->ppid;
904         rinfo.rcv_flags = event->flags;
905         rinfo.rcv_tsn = event->tsn;
906         rinfo.rcv_cumtsn = event->cumtsn;
907         rinfo.rcv_assoc_id = sctp_assoc2id(event->asoc);
908         rinfo.rcv_context = event->asoc->default_rcv_context;
909 
910         put_cmsg(msghdr, IPPROTO_SCTP, SCTP_RCVINFO,
911                  sizeof(rinfo), &rinfo);
912 }
913 
914 /* RFC6458, Section 5.3.6. SCTP Next Receive Information Structure
915  * (SCTP_NXTINFO)
916  */
917 static void __sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event,
918                                          struct msghdr *msghdr,
919                                          const struct sk_buff *skb)
920 {
921         struct sctp_nxtinfo nxtinfo;
922 
923         memset(&nxtinfo, 0, sizeof(nxtinfo));
924         nxtinfo.nxt_sid = event->stream;
925         nxtinfo.nxt_ppid = event->ppid;
926         nxtinfo.nxt_flags = event->flags;
927         if (sctp_ulpevent_is_notification(event))
928                 nxtinfo.nxt_flags |= SCTP_NOTIFICATION;
929         nxtinfo.nxt_length = skb->len;
930         nxtinfo.nxt_assoc_id = sctp_assoc2id(event->asoc);
931 
932         put_cmsg(msghdr, IPPROTO_SCTP, SCTP_NXTINFO,
933                  sizeof(nxtinfo), &nxtinfo);
934 }
935 
936 void sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event,
937                                 struct msghdr *msghdr,
938                                 struct sock *sk)
939 {
940         struct sk_buff *skb;
941         int err;
942 
943         skb = sctp_skb_recv_datagram(sk, MSG_PEEK, 1, &err);
944         if (skb != NULL) {
945                 __sctp_ulpevent_read_nxtinfo(sctp_skb2event(skb),
946                                              msghdr, skb);
947                 /* Just release refcount here. */
948                 kfree_skb(skb);
949         }
950 }
951 
952 /* Do accounting for bytes received and hold a reference to the association
953  * for each skb.
954  */
955 static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
956                                        struct sctp_association *asoc)
957 {
958         struct sk_buff *skb, *frag;
959 
960         skb = sctp_event2skb(event);
961         /* Set the owner and charge rwnd for bytes received.  */
962         sctp_ulpevent_set_owner(event, asoc);
963         sctp_assoc_rwnd_decrease(asoc, skb_headlen(skb));
964 
965         if (!skb->data_len)
966                 return;
967 
968         /* Note:  Not clearing the entire event struct as this is just a
969          * fragment of the real event.  However, we still need to do rwnd
970          * accounting.
971          * In general, the skb passed from IP can have only 1 level of
972          * fragments. But we allow multiple levels of fragments.
973          */
974         skb_walk_frags(skb, frag)
975                 sctp_ulpevent_receive_data(sctp_skb2event(frag), asoc);
976 }
977 
978 /* Do accounting for bytes just read by user and release the references to
979  * the association.
980  */
981 static void sctp_ulpevent_release_data(struct sctp_ulpevent *event)
982 {
983         struct sk_buff *skb, *frag;
984         unsigned int    len;
985 
986         /* Current stack structures assume that the rcv buffer is
987          * per socket.   For UDP style sockets this is not true as
988          * multiple associations may be on a single UDP-style socket.
989          * Use the local private area of the skb to track the owning
990          * association.
991          */
992 
993         skb = sctp_event2skb(event);
994         len = skb->len;
995 
996         if (!skb->data_len)
997                 goto done;
998 
999         /* Don't forget the fragments. */
1000         skb_walk_frags(skb, frag) {
1001                 /* NOTE:  skb_shinfos are recursive. Although IP returns
1002                  * skb's with only 1 level of fragments, SCTP reassembly can
1003                  * increase the levels.
1004                  */
1005                 sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
1006         }
1007 
1008 done:
1009         sctp_assoc_rwnd_increase(event->asoc, len);
1010         sctp_ulpevent_release_owner(event);
1011 }
1012 
1013 static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event)
1014 {
1015         struct sk_buff *skb, *frag;
1016 
1017         skb = sctp_event2skb(event);
1018 
1019         if (!skb->data_len)
1020                 goto done;
1021 
1022         /* Don't forget the fragments. */
1023         skb_walk_frags(skb, frag) {
1024                 /* NOTE:  skb_shinfos are recursive. Although IP returns
1025                  * skb's with only 1 level of fragments, SCTP reassembly can
1026                  * increase the levels.
1027                  */
1028                 sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
1029         }
1030 
1031 done:
1032         sctp_ulpevent_release_owner(event);
1033 }
1034 
1035 /* Free a ulpevent that has an owner.  It includes releasing the reference
1036  * to the owner, updating the rwnd in case of a DATA event and freeing the
1037  * skb.
1038  */
1039 void sctp_ulpevent_free(struct sctp_ulpevent *event)
1040 {
1041         if (sctp_ulpevent_is_notification(event))
1042                 sctp_ulpevent_release_owner(event);
1043         else
1044                 sctp_ulpevent_release_data(event);
1045 
1046         kfree_skb(sctp_event2skb(event));
1047 }
1048 
1049 /* Purge the skb lists holding ulpevents. */
1050 unsigned int sctp_queue_purge_ulpevents(struct sk_buff_head *list)
1051 {
1052         struct sk_buff *skb;
1053         unsigned int data_unread = 0;
1054 
1055         while ((skb = skb_dequeue(list)) != NULL) {
1056                 struct sctp_ulpevent *event = sctp_skb2event(skb);
1057 
1058                 if (!sctp_ulpevent_is_notification(event))
1059                         data_unread += skb->len;
1060 
1061                 sctp_ulpevent_free(event);
1062         }
1063 
1064         return data_unread;
1065 }
1066 

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