Linux Audio

Check our new training course

Loading...
v6.13.7
   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
  31static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
  32				       struct sctp_association *asoc);
  33static void sctp_ulpevent_release_data(struct sctp_ulpevent *event);
  34static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event);
  35
  36
  37/* Initialize an ULP event from an given skb.  */
  38static 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.  */
  48static 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
  63fail:
  64	return NULL;
  65}
  66
  67/* Is this a MSG_NOTIFICATION?  */
  68int 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 */
  76static 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. */
  95static 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 */
 114struct 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
 229fail:
 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 */
 241static 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
 335fail:
 336	return NULL;
 337}
 338
 339void 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 */
 373struct sctp_ulpevent *
 374sctp_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;
 421fail:
 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 */
 430struct 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
 529fail:
 530	return NULL;
 531}
 532
 533struct 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 */
 577struct 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
 631fail:
 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 */
 640struct 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
 664fail:
 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 */
 675struct 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
 757fail_mark:
 758	kfree_skb(skb);
 759fail:
 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 */
 771struct 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;
 821fail:
 822	return NULL;
 823}
 824
 825struct 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;
 856fail:
 857	return NULL;
 858}
 859
 860/*
 861 * Socket Extensions for SCTP
 862 * 6.3.10. SCTP_SENDER_DRY_EVENT
 863 */
 864struct 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
 888struct 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
 917struct 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
 944struct 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 */
 987void 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 */
1015void 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 */
1040static 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
1059void 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 */
1078static 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 */
1104static 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
1131done:
1132	sctp_assoc_rwnd_increase(event->asoc, len);
1133	sctp_chunk_put(event->chunk);
1134	sctp_ulpevent_release_owner(event);
1135}
1136
1137static 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
1155done:
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 */
1164void 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. */
1175unsigned 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}
v4.17
 
   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
  46static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
  47				       struct sctp_association *asoc);
  48static void sctp_ulpevent_release_data(struct sctp_ulpevent *event);
  49static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event);
  50
  51
  52/* Initialize an ULP event from an given skb.  */
  53static void sctp_ulpevent_init(struct sctp_ulpevent *event,
  54			       __u16 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.  */
  63static struct sctp_ulpevent *sctp_ulpevent_new(int size, __u16 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
  78fail:
  79	return NULL;
  80}
  81
  82/* Is this a MSG_NOTIFICATION?  */
  83int 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 */
  91static inline void sctp_ulpevent_set_owner(struct sctp_ulpevent *event,
  92					   const struct sctp_association *asoc)
  93{
  94	struct sctp_chunk *chunk = event->chunk;
  95	struct sk_buff *skb;
  96
  97	/* Cast away the const, as we are just wanting to
  98	 * bump the reference count.
  99	 */
 100	sctp_association_hold((struct sctp_association *)asoc);
 101	skb = sctp_event2skb(event);
 102	event->asoc = (struct sctp_association *)asoc;
 103	atomic_add(event->rmem_len, &event->asoc->rmem_alloc);
 104	sctp_skb_set_owner_r(skb, asoc->base.sk);
 105	if (chunk && chunk->head_skb && !chunk->head_skb->sk)
 106		chunk->head_skb->sk = asoc->base.sk;
 107}
 108
 109/* A simple destructor to give up the reference to the association. */
 110static inline void sctp_ulpevent_release_owner(struct sctp_ulpevent *event)
 111{
 112	struct sctp_association *asoc = event->asoc;
 113
 114	atomic_sub(event->rmem_len, &asoc->rmem_alloc);
 115	sctp_association_put(asoc);
 116}
 117
 118/* Create and initialize an SCTP_ASSOC_CHANGE event.
 119 *
 120 * 5.3.1.1 SCTP_ASSOC_CHANGE
 121 *
 122 * Communication notifications inform the ULP that an SCTP association
 123 * has either begun or ended. The identifier for a new association is
 124 * provided by this notification.
 125 *
 126 * Note: There is no field checking here.  If a field is unused it will be
 127 * zero'd out.
 128 */
 129struct sctp_ulpevent  *sctp_ulpevent_make_assoc_change(
 130	const struct sctp_association *asoc,
 131	__u16 flags, __u16 state, __u16 error, __u16 outbound,
 132	__u16 inbound, struct sctp_chunk *chunk, gfp_t gfp)
 133{
 134	struct sctp_ulpevent *event;
 135	struct sctp_assoc_change *sac;
 136	struct sk_buff *skb;
 137
 138	/* If the lower layer passed in the chunk, it will be
 139	 * an ABORT, so we need to include it in the sac_info.
 140	 */
 141	if (chunk) {
 142		/* Copy the chunk data to a new skb and reserve enough
 143		 * head room to use as notification.
 144		 */
 145		skb = skb_copy_expand(chunk->skb,
 146				      sizeof(struct sctp_assoc_change), 0, gfp);
 147
 148		if (!skb)
 149			goto fail;
 150
 151		/* Embed the event fields inside the cloned skb.  */
 152		event = sctp_skb2event(skb);
 153		sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
 154
 155		/* Include the notification structure */
 156		sac = skb_push(skb, sizeof(struct sctp_assoc_change));
 157
 158		/* Trim the buffer to the right length.  */
 159		skb_trim(skb, sizeof(struct sctp_assoc_change) +
 160			 ntohs(chunk->chunk_hdr->length) -
 161			 sizeof(struct sctp_chunkhdr));
 162	} else {
 163		event = sctp_ulpevent_new(sizeof(struct sctp_assoc_change),
 164				  MSG_NOTIFICATION, gfp);
 165		if (!event)
 166			goto fail;
 167
 168		skb = sctp_event2skb(event);
 169		sac = skb_put(skb, sizeof(struct sctp_assoc_change));
 170	}
 171
 172	/* Socket Extensions for SCTP
 173	 * 5.3.1.1 SCTP_ASSOC_CHANGE
 174	 *
 175	 * sac_type:
 176	 * It should be SCTP_ASSOC_CHANGE.
 177	 */
 178	sac->sac_type = SCTP_ASSOC_CHANGE;
 179
 180	/* Socket Extensions for SCTP
 181	 * 5.3.1.1 SCTP_ASSOC_CHANGE
 182	 *
 183	 * sac_state: 32 bits (signed integer)
 184	 * This field holds one of a number of values that communicate the
 185	 * event that happened to the association.
 186	 */
 187	sac->sac_state = state;
 188
 189	/* Socket Extensions for SCTP
 190	 * 5.3.1.1 SCTP_ASSOC_CHANGE
 191	 *
 192	 * sac_flags: 16 bits (unsigned integer)
 193	 * Currently unused.
 194	 */
 195	sac->sac_flags = 0;
 196
 197	/* Socket Extensions for SCTP
 198	 * 5.3.1.1 SCTP_ASSOC_CHANGE
 199	 *
 200	 * sac_length: sizeof (__u32)
 201	 * This field is the total length of the notification data, including
 202	 * the notification header.
 203	 */
 204	sac->sac_length = skb->len;
 205
 206	/* Socket Extensions for SCTP
 207	 * 5.3.1.1 SCTP_ASSOC_CHANGE
 208	 *
 209	 * sac_error:  32 bits (signed integer)
 210	 *
 211	 * If the state was reached due to a error condition (e.g.
 212	 * COMMUNICATION_LOST) any relevant error information is available in
 213	 * this field. This corresponds to the protocol error codes defined in
 214	 * [SCTP].
 215	 */
 216	sac->sac_error = error;
 217
 218	/* Socket Extensions for SCTP
 219	 * 5.3.1.1 SCTP_ASSOC_CHANGE
 220	 *
 221	 * sac_outbound_streams:  16 bits (unsigned integer)
 222	 * sac_inbound_streams:  16 bits (unsigned integer)
 223	 *
 224	 * The maximum number of streams allowed in each direction are
 225	 * available in sac_outbound_streams and sac_inbound streams.
 226	 */
 227	sac->sac_outbound_streams = outbound;
 228	sac->sac_inbound_streams = inbound;
 229
 230	/* Socket Extensions for SCTP
 231	 * 5.3.1.1 SCTP_ASSOC_CHANGE
 232	 *
 233	 * sac_assoc_id: sizeof (sctp_assoc_t)
 234	 *
 235	 * The association id field, holds the identifier for the association.
 236	 * All notifications for a given association have the same association
 237	 * identifier.  For TCP style socket, this field is ignored.
 238	 */
 239	sctp_ulpevent_set_owner(event, asoc);
 240	sac->sac_assoc_id = sctp_assoc2id(asoc);
 241
 242	return event;
 243
 244fail:
 245	return NULL;
 246}
 247
 248/* Create and initialize an SCTP_PEER_ADDR_CHANGE event.
 249 *
 250 * Socket Extensions for SCTP - draft-01
 251 * 5.3.1.2 SCTP_PEER_ADDR_CHANGE
 252 *
 253 * When a destination address on a multi-homed peer encounters a change
 254 * an interface details event is sent.
 255 */
 256struct sctp_ulpevent *sctp_ulpevent_make_peer_addr_change(
 257	const struct sctp_association *asoc,
 258	const struct sockaddr_storage *aaddr,
 259	int flags, int state, int error, gfp_t gfp)
 260{
 261	struct sctp_ulpevent *event;
 262	struct sctp_paddr_change  *spc;
 263	struct sk_buff *skb;
 264
 265	event = sctp_ulpevent_new(sizeof(struct sctp_paddr_change),
 266				  MSG_NOTIFICATION, gfp);
 267	if (!event)
 268		goto fail;
 269
 270	skb = sctp_event2skb(event);
 271	spc = 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
 350fail:
 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 */
 369struct sctp_ulpevent *
 370sctp_ulpevent_make_remote_error(const struct sctp_association *asoc,
 371				struct sctp_chunk *chunk, __u16 flags,
 372				gfp_t gfp)
 373{
 374	struct sctp_remote_error *sre;
 375	struct sctp_ulpevent *event;
 376	struct sctp_errhdr *ch;
 377	struct sk_buff *skb;
 378	__be16 cause;
 379	int elen;
 380
 381	ch = (struct sctp_errhdr *)(chunk->skb->data);
 382	cause = ch->cause;
 383	elen = SCTP_PAD4(ntohs(ch->length)) - sizeof(*ch);
 384
 385	/* Pull off the ERROR header.  */
 386	skb_pull(chunk->skb, sizeof(*ch));
 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 = 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;
 417fail:
 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 */
 426struct 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, sctp_datachk_len(&asoc->stream));
 447	len -= sctp_datachk_len(&asoc->stream);
 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 = skb_push(skb, sizeof(struct sctp_send_failed));
 454
 455	/* Socket Extensions for SCTP
 456	 * 5.3.1.4 SCTP_SEND_FAILED
 457	 *
 458	 * ssf_type:
 459	 * It should be SCTP_SEND_FAILED.
 460	 */
 461	ssf->ssf_type = SCTP_SEND_FAILED;
 462
 463	/* Socket Extensions for SCTP
 464	 * 5.3.1.4 SCTP_SEND_FAILED
 465	 *
 466	 * ssf_flags: 16 bits (unsigned integer)
 467	 * The flag value will take one of the following values
 468	 *
 469	 * SCTP_DATA_UNSENT - Indicates that the data was never put on
 470	 *                    the wire.
 471	 *
 472	 * SCTP_DATA_SENT   - Indicates that the data was put on the wire.
 473	 *                    Note that this does not necessarily mean that the
 474	 *                    data was (or was not) successfully delivered.
 475	 */
 476	ssf->ssf_flags = flags;
 477
 478	/* Socket Extensions for SCTP
 479	 * 5.3.1.4 SCTP_SEND_FAILED
 480	 *
 481	 * ssf_length: sizeof (__u32)
 482	 * This field is the total length of the notification data, including
 483	 * the notification header.
 484	 */
 485	ssf->ssf_length = sizeof(struct sctp_send_failed) + len;
 486	skb_trim(skb, ssf->ssf_length);
 487
 488	/* Socket Extensions for SCTP
 489	 * 5.3.1.4 SCTP_SEND_FAILED
 490	 *
 491	 * ssf_error: 16 bits (unsigned integer)
 492	 * This value represents the reason why the send failed, and if set,
 493	 * will be a SCTP protocol error code as defined in [SCTP] section
 494	 * 3.3.10.
 495	 */
 496	ssf->ssf_error = error;
 497
 498	/* Socket Extensions for SCTP
 499	 * 5.3.1.4 SCTP_SEND_FAILED
 500	 *
 501	 * ssf_info: sizeof (struct sctp_sndrcvinfo)
 502	 * The original send information associated with the undelivered
 503	 * message.
 504	 */
 505	memcpy(&ssf->ssf_info, &chunk->sinfo, sizeof(struct sctp_sndrcvinfo));
 506
 507	/* Per TSVWG discussion with Randy. Allow the application to
 508	 * reassemble a fragmented message.
 509	 */
 510	ssf->ssf_info.sinfo_flags = chunk->chunk_hdr->flags;
 511
 512	/* Socket Extensions for SCTP
 513	 * 5.3.1.4 SCTP_SEND_FAILED
 514	 *
 515	 * ssf_assoc_id: sizeof (sctp_assoc_t)
 516	 * The association id field, sf_assoc_id, holds the identifier for the
 517	 * association.  All notifications for a given association have the
 518	 * same association identifier.  For TCP style socket, this field is
 519	 * ignored.
 520	 */
 521	sctp_ulpevent_set_owner(event, asoc);
 522	ssf->ssf_assoc_id = sctp_assoc2id(asoc);
 523	return event;
 524
 525fail:
 526	return NULL;
 527}
 528
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 529/* Create and initialize a SCTP_SHUTDOWN_EVENT notification.
 530 *
 531 * Socket Extensions for SCTP - draft-01
 532 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
 533 */
 534struct sctp_ulpevent *sctp_ulpevent_make_shutdown_event(
 535	const struct sctp_association *asoc,
 536	__u16 flags, gfp_t gfp)
 537{
 538	struct sctp_ulpevent *event;
 539	struct sctp_shutdown_event *sse;
 540	struct sk_buff *skb;
 541
 542	event = sctp_ulpevent_new(sizeof(struct sctp_shutdown_event),
 543				  MSG_NOTIFICATION, gfp);
 544	if (!event)
 545		goto fail;
 546
 547	skb = sctp_event2skb(event);
 548	sse = skb_put(skb, sizeof(struct sctp_shutdown_event));
 549
 550	/* Socket Extensions for SCTP
 551	 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
 552	 *
 553	 * sse_type
 554	 * It should be SCTP_SHUTDOWN_EVENT
 555	 */
 556	sse->sse_type = SCTP_SHUTDOWN_EVENT;
 557
 558	/* Socket Extensions for SCTP
 559	 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
 560	 *
 561	 * sse_flags: 16 bits (unsigned integer)
 562	 * Currently unused.
 563	 */
 564	sse->sse_flags = 0;
 565
 566	/* Socket Extensions for SCTP
 567	 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
 568	 *
 569	 * sse_length: sizeof (__u32)
 570	 * This field is the total length of the notification data, including
 571	 * the notification header.
 572	 */
 573	sse->sse_length = sizeof(struct sctp_shutdown_event);
 574
 575	/* Socket Extensions for SCTP
 576	 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
 577	 *
 578	 * sse_assoc_id: sizeof (sctp_assoc_t)
 579	 * The association id field, holds the identifier for the association.
 580	 * All notifications for a given association have the same association
 581	 * identifier.  For TCP style socket, this field is ignored.
 582	 */
 583	sctp_ulpevent_set_owner(event, asoc);
 584	sse->sse_assoc_id = sctp_assoc2id(asoc);
 585
 586	return event;
 587
 588fail:
 589	return NULL;
 590}
 591
 592/* Create and initialize a SCTP_ADAPTATION_INDICATION notification.
 593 *
 594 * Socket Extensions for SCTP
 595 * 5.3.1.6 SCTP_ADAPTATION_INDICATION
 596 */
 597struct sctp_ulpevent *sctp_ulpevent_make_adaptation_indication(
 598	const struct sctp_association *asoc, gfp_t gfp)
 599{
 600	struct sctp_ulpevent *event;
 601	struct sctp_adaptation_event *sai;
 602	struct sk_buff *skb;
 603
 604	event = sctp_ulpevent_new(sizeof(struct sctp_adaptation_event),
 605				  MSG_NOTIFICATION, gfp);
 606	if (!event)
 607		goto fail;
 608
 609	skb = sctp_event2skb(event);
 610	sai = skb_put(skb, sizeof(struct sctp_adaptation_event));
 611
 612	sai->sai_type = SCTP_ADAPTATION_INDICATION;
 613	sai->sai_flags = 0;
 614	sai->sai_length = sizeof(struct sctp_adaptation_event);
 615	sai->sai_adaptation_ind = asoc->peer.adaptation_ind;
 616	sctp_ulpevent_set_owner(event, asoc);
 617	sai->sai_assoc_id = sctp_assoc2id(asoc);
 618
 619	return event;
 620
 621fail:
 622	return NULL;
 623}
 624
 625/* A message has been received.  Package this message as a notification
 626 * to pass it to the upper layers.  Go ahead and calculate the sndrcvinfo
 627 * even if filtered out later.
 628 *
 629 * Socket Extensions for SCTP
 630 * 5.2.2 SCTP Header Information Structure (SCTP_SNDRCV)
 631 */
 632struct sctp_ulpevent *sctp_ulpevent_make_rcvmsg(struct sctp_association *asoc,
 633						struct sctp_chunk *chunk,
 634						gfp_t gfp)
 635{
 636	struct sctp_ulpevent *event = NULL;
 637	struct sk_buff *skb;
 638	size_t padding, len;
 
 639	int rx_count;
 640
 641	/*
 642	 * check to see if we need to make space for this
 643	 * new skb, expand the rcvbuffer if needed, or drop
 644	 * the frame
 645	 */
 646	if (asoc->ep->rcvbuf_policy)
 647		rx_count = atomic_read(&asoc->rmem_alloc);
 648	else
 649		rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);
 650
 651	if (rx_count >= asoc->base.sk->sk_rcvbuf) {
 652
 653		if ((asoc->base.sk->sk_userlocks & SOCK_RCVBUF_LOCK) ||
 654		    (!sk_rmem_schedule(asoc->base.sk, chunk->skb,
 655				       chunk->skb->truesize)))
 656			goto fail;
 657	}
 658
 659	/* Clone the original skb, sharing the data.  */
 660	skb = skb_clone(chunk->skb, gfp);
 661	if (!skb)
 662		goto fail;
 663
 664	/* Now that all memory allocations for this chunk succeeded, we
 665	 * can mark it as received so the tsn_map is updated correctly.
 666	 */
 667	if (sctp_tsnmap_mark(&asoc->peer.tsn_map,
 668			     ntohl(chunk->subh.data_hdr->tsn),
 669			     chunk->transport))
 670		goto fail_mark;
 671
 672	/* First calculate the padding, so we don't inadvertently
 673	 * pass up the wrong length to the user.
 674	 *
 675	 * RFC 2960 - Section 3.2  Chunk Field Descriptions
 676	 *
 677	 * The total length of a chunk(including Type, Length and Value fields)
 678	 * MUST be a multiple of 4 bytes.  If the length of the chunk is not a
 679	 * multiple of 4 bytes, the sender MUST pad the chunk with all zero
 680	 * bytes and this padding is not included in the chunk length field.
 681	 * The sender should never pad with more than 3 bytes.  The receiver
 682	 * MUST ignore the padding bytes.
 683	 */
 684	len = ntohs(chunk->chunk_hdr->length);
 685	padding = SCTP_PAD4(len) - len;
 686
 687	/* Fixup cloned skb with just this chunks data.  */
 688	skb_trim(skb, chunk->chunk_end - padding - skb->data);
 689
 690	/* Embed the event fields inside the cloned skb.  */
 691	event = sctp_skb2event(skb);
 692
 693	/* Initialize event with flags 0  and correct length
 694	 * Since this is a clone of the original skb, only account for
 695	 * the data of this chunk as other chunks will be accounted separately.
 696	 */
 697	sctp_ulpevent_init(event, 0, skb->len + sizeof(struct sk_buff));
 698
 699	/* And hold the chunk as we need it for getting the IP headers
 700	 * later in recvmsg
 701	 */
 702	sctp_chunk_hold(chunk);
 703	event->chunk = chunk;
 704
 705	sctp_ulpevent_receive_data(event, asoc);
 706
 707	event->stream = ntohs(chunk->subh.data_hdr->stream);
 708	if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
 709		event->flags |= SCTP_UNORDERED;
 710		event->cumtsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
 711	}
 712	event->tsn = ntohl(chunk->subh.data_hdr->tsn);
 713	event->msg_flags |= chunk->chunk_hdr->flags;
 714
 715	return event;
 716
 717fail_mark:
 718	kfree_skb(skb);
 719fail:
 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 */
 731struct sctp_ulpevent *sctp_ulpevent_make_pdapi(
 732					const struct sctp_association *asoc,
 733					__u32 indication, __u32 sid, __u32 seq,
 734					__u32 flags, gfp_t gfp)
 735{
 736	struct sctp_ulpevent *event;
 737	struct sctp_pdapi_event *pd;
 738	struct sk_buff *skb;
 739
 740	event = sctp_ulpevent_new(sizeof(struct sctp_pdapi_event),
 741				  MSG_NOTIFICATION, gfp);
 742	if (!event)
 743		goto fail;
 744
 745	skb = sctp_event2skb(event);
 746	pd = 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 = flags;
 756	pd->pdapi_stream = sid;
 757	pd->pdapi_seq = seq;
 758
 759	/* pdapi_length: 32 bits (unsigned integer)
 760	 *
 761	 * This field is the total length of the notification data, including
 762	 * the notification header.  It will generally be sizeof (struct
 763	 * sctp_pdapi_event).
 764	 */
 765	pd->pdapi_length = sizeof(struct sctp_pdapi_event);
 766
 767	/*  pdapi_indication: 32 bits (unsigned integer)
 768	 *
 769	 * This field holds the indication being sent to the application.
 770	 */
 771	pd->pdapi_indication = indication;
 772
 773	/*  pdapi_assoc_id: sizeof (sctp_assoc_t)
 774	 *
 775	 * The association id field, holds the identifier for the association.
 776	 */
 777	sctp_ulpevent_set_owner(event, asoc);
 778	pd->pdapi_assoc_id = sctp_assoc2id(asoc);
 779
 780	return event;
 781fail:
 782	return NULL;
 783}
 784
 785struct sctp_ulpevent *sctp_ulpevent_make_authkey(
 786	const struct sctp_association *asoc, __u16 key_id,
 787	__u32 indication, gfp_t gfp)
 788{
 789	struct sctp_ulpevent *event;
 790	struct sctp_authkey_event *ak;
 791	struct sk_buff *skb;
 792
 793	event = sctp_ulpevent_new(sizeof(struct sctp_authkey_event),
 794				  MSG_NOTIFICATION, gfp);
 795	if (!event)
 796		goto fail;
 797
 798	skb = sctp_event2skb(event);
 799	ak = skb_put(skb, sizeof(struct sctp_authkey_event));
 800
 801	ak->auth_type = SCTP_AUTHENTICATION_EVENT;
 802	ak->auth_flags = 0;
 803	ak->auth_length = sizeof(struct sctp_authkey_event);
 804
 805	ak->auth_keynumber = key_id;
 806	ak->auth_altkeynumber = 0;
 807	ak->auth_indication = indication;
 808
 809	/*
 810	 * The association id field, holds the identifier for the association.
 811	 */
 812	sctp_ulpevent_set_owner(event, asoc);
 813	ak->auth_assoc_id = sctp_assoc2id(asoc);
 814
 815	return event;
 816fail:
 817	return NULL;
 818}
 819
 820/*
 821 * Socket Extensions for SCTP
 822 * 6.3.10. SCTP_SENDER_DRY_EVENT
 823 */
 824struct sctp_ulpevent *sctp_ulpevent_make_sender_dry_event(
 825	const struct sctp_association *asoc, gfp_t gfp)
 826{
 827	struct sctp_ulpevent *event;
 828	struct sctp_sender_dry_event *sdry;
 829	struct sk_buff *skb;
 830
 831	event = sctp_ulpevent_new(sizeof(struct sctp_sender_dry_event),
 832				  MSG_NOTIFICATION, gfp);
 833	if (!event)
 834		return NULL;
 835
 836	skb = sctp_event2skb(event);
 837	sdry = 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
 848struct sctp_ulpevent *sctp_ulpevent_make_stream_reset_event(
 849	const struct sctp_association *asoc, __u16 flags, __u16 stream_num,
 850	__be16 *stream_list, gfp_t gfp)
 851{
 852	struct sctp_stream_reset_event *sreset;
 853	struct sctp_ulpevent *event;
 854	struct sk_buff *skb;
 855	int length, i;
 856
 857	length = sizeof(struct sctp_stream_reset_event) + 2 * stream_num;
 858	event = sctp_ulpevent_new(length, MSG_NOTIFICATION, gfp);
 859	if (!event)
 860		return NULL;
 861
 862	skb = sctp_event2skb(event);
 863	sreset = skb_put(skb, length);
 864
 865	sreset->strreset_type = SCTP_STREAM_RESET_EVENT;
 866	sreset->strreset_flags = flags;
 867	sreset->strreset_length = length;
 868	sctp_ulpevent_set_owner(event, asoc);
 869	sreset->strreset_assoc_id = sctp_assoc2id(asoc);
 870
 871	for (i = 0; i < stream_num; i++)
 872		sreset->strreset_stream_list[i] = ntohs(stream_list[i]);
 873
 874	return event;
 875}
 876
 877struct sctp_ulpevent *sctp_ulpevent_make_assoc_reset_event(
 878	const struct sctp_association *asoc, __u16 flags, __u32 local_tsn,
 879	__u32 remote_tsn, gfp_t gfp)
 880{
 881	struct sctp_assoc_reset_event *areset;
 882	struct sctp_ulpevent *event;
 883	struct sk_buff *skb;
 884
 885	event = sctp_ulpevent_new(sizeof(struct sctp_assoc_reset_event),
 886				  MSG_NOTIFICATION, gfp);
 887	if (!event)
 888		return NULL;
 889
 890	skb = sctp_event2skb(event);
 891	areset = skb_put(skb, sizeof(struct sctp_assoc_reset_event));
 892
 893	areset->assocreset_type = SCTP_ASSOC_RESET_EVENT;
 894	areset->assocreset_flags = flags;
 895	areset->assocreset_length = sizeof(struct sctp_assoc_reset_event);
 896	sctp_ulpevent_set_owner(event, asoc);
 897	areset->assocreset_assoc_id = sctp_assoc2id(asoc);
 898	areset->assocreset_local_tsn = local_tsn;
 899	areset->assocreset_remote_tsn = remote_tsn;
 900
 901	return event;
 902}
 903
 904struct sctp_ulpevent *sctp_ulpevent_make_stream_change_event(
 905	const struct sctp_association *asoc, __u16 flags,
 906	__u32 strchange_instrms, __u32 strchange_outstrms, gfp_t gfp)
 907{
 908	struct sctp_stream_change_event *schange;
 909	struct sctp_ulpevent *event;
 910	struct sk_buff *skb;
 911
 912	event = sctp_ulpevent_new(sizeof(struct sctp_stream_change_event),
 913				  MSG_NOTIFICATION, gfp);
 914	if (!event)
 915		return NULL;
 916
 917	skb = sctp_event2skb(event);
 918	schange = skb_put(skb, sizeof(struct sctp_stream_change_event));
 919
 920	schange->strchange_type = SCTP_STREAM_CHANGE_EVENT;
 921	schange->strchange_flags = flags;
 922	schange->strchange_length = sizeof(struct sctp_stream_change_event);
 923	sctp_ulpevent_set_owner(event, asoc);
 924	schange->strchange_assoc_id = sctp_assoc2id(asoc);
 925	schange->strchange_instrms = strchange_instrms;
 926	schange->strchange_outstrms = strchange_outstrms;
 927
 928	return event;
 929}
 930
 931/* Return the notification type, assuming this is a notification
 932 * event.
 933 */
 934__u16 sctp_ulpevent_get_notification_type(const struct sctp_ulpevent *event)
 935{
 936	union sctp_notification *notification;
 937	struct sk_buff *skb;
 938
 939	skb = sctp_event2skb(event);
 940	notification = (union sctp_notification *) skb->data;
 941	return notification->sn_header.sn_type;
 942}
 943
 944/* RFC6458, Section 5.3.2. SCTP Header Information Structure
 945 * (SCTP_SNDRCV, DEPRECATED)
 946 */
 947void sctp_ulpevent_read_sndrcvinfo(const struct sctp_ulpevent *event,
 948				   struct msghdr *msghdr)
 949{
 950	struct sctp_sndrcvinfo sinfo;
 951
 952	if (sctp_ulpevent_is_notification(event))
 953		return;
 954
 955	memset(&sinfo, 0, sizeof(sinfo));
 956	sinfo.sinfo_stream = event->stream;
 957	sinfo.sinfo_ssn = event->ssn;
 958	sinfo.sinfo_ppid = event->ppid;
 959	sinfo.sinfo_flags = event->flags;
 960	sinfo.sinfo_tsn = event->tsn;
 961	sinfo.sinfo_cumtsn = event->cumtsn;
 962	sinfo.sinfo_assoc_id = sctp_assoc2id(event->asoc);
 963	/* Context value that is set via SCTP_CONTEXT socket option. */
 964	sinfo.sinfo_context = event->asoc->default_rcv_context;
 965	/* These fields are not used while receiving. */
 966	sinfo.sinfo_timetolive = 0;
 967
 968	put_cmsg(msghdr, IPPROTO_SCTP, SCTP_SNDRCV,
 969		 sizeof(sinfo), &sinfo);
 970}
 971
 972/* RFC6458, Section 5.3.5 SCTP Receive Information Structure
 973 * (SCTP_SNDRCV)
 974 */
 975void sctp_ulpevent_read_rcvinfo(const struct sctp_ulpevent *event,
 976				struct msghdr *msghdr)
 977{
 978	struct sctp_rcvinfo rinfo;
 979
 980	if (sctp_ulpevent_is_notification(event))
 981		return;
 982
 983	memset(&rinfo, 0, sizeof(struct sctp_rcvinfo));
 984	rinfo.rcv_sid = event->stream;
 985	rinfo.rcv_ssn = event->ssn;
 986	rinfo.rcv_ppid = event->ppid;
 987	rinfo.rcv_flags = event->flags;
 988	rinfo.rcv_tsn = event->tsn;
 989	rinfo.rcv_cumtsn = event->cumtsn;
 990	rinfo.rcv_assoc_id = sctp_assoc2id(event->asoc);
 991	rinfo.rcv_context = event->asoc->default_rcv_context;
 992
 993	put_cmsg(msghdr, IPPROTO_SCTP, SCTP_RCVINFO,
 994		 sizeof(rinfo), &rinfo);
 995}
 996
 997/* RFC6458, Section 5.3.6. SCTP Next Receive Information Structure
 998 * (SCTP_NXTINFO)
 999 */
1000static void __sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event,
1001					 struct msghdr *msghdr,
1002					 const struct sk_buff *skb)
1003{
1004	struct sctp_nxtinfo nxtinfo;
1005
1006	memset(&nxtinfo, 0, sizeof(nxtinfo));
1007	nxtinfo.nxt_sid = event->stream;
1008	nxtinfo.nxt_ppid = event->ppid;
1009	nxtinfo.nxt_flags = event->flags;
1010	if (sctp_ulpevent_is_notification(event))
1011		nxtinfo.nxt_flags |= SCTP_NOTIFICATION;
1012	nxtinfo.nxt_length = skb->len;
1013	nxtinfo.nxt_assoc_id = sctp_assoc2id(event->asoc);
1014
1015	put_cmsg(msghdr, IPPROTO_SCTP, SCTP_NXTINFO,
1016		 sizeof(nxtinfo), &nxtinfo);
1017}
1018
1019void sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event,
1020				struct msghdr *msghdr,
1021				struct sock *sk)
1022{
1023	struct sk_buff *skb;
1024	int err;
1025
1026	skb = sctp_skb_recv_datagram(sk, MSG_PEEK, 1, &err);
1027	if (skb != NULL) {
1028		__sctp_ulpevent_read_nxtinfo(sctp_skb2event(skb),
1029					     msghdr, skb);
1030		/* Just release refcount here. */
1031		kfree_skb(skb);
1032	}
1033}
1034
1035/* Do accounting for bytes received and hold a reference to the association
1036 * for each skb.
1037 */
1038static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
1039				       struct sctp_association *asoc)
1040{
1041	struct sk_buff *skb, *frag;
1042
1043	skb = sctp_event2skb(event);
1044	/* Set the owner and charge rwnd for bytes received.  */
1045	sctp_ulpevent_set_owner(event, asoc);
1046	sctp_assoc_rwnd_decrease(asoc, skb_headlen(skb));
1047
1048	if (!skb->data_len)
1049		return;
1050
1051	/* Note:  Not clearing the entire event struct as this is just a
1052	 * fragment of the real event.  However, we still need to do rwnd
1053	 * accounting.
1054	 * In general, the skb passed from IP can have only 1 level of
1055	 * fragments. But we allow multiple levels of fragments.
1056	 */
1057	skb_walk_frags(skb, frag)
1058		sctp_ulpevent_receive_data(sctp_skb2event(frag), asoc);
1059}
1060
1061/* Do accounting for bytes just read by user and release the references to
1062 * the association.
1063 */
1064static void sctp_ulpevent_release_data(struct sctp_ulpevent *event)
1065{
1066	struct sk_buff *skb, *frag;
1067	unsigned int	len;
1068
1069	/* Current stack structures assume that the rcv buffer is
1070	 * per socket.   For UDP style sockets this is not true as
1071	 * multiple associations may be on a single UDP-style socket.
1072	 * Use the local private area of the skb to track the owning
1073	 * association.
1074	 */
1075
1076	skb = sctp_event2skb(event);
1077	len = skb->len;
1078
1079	if (!skb->data_len)
1080		goto done;
1081
1082	/* Don't forget the fragments. */
1083	skb_walk_frags(skb, frag) {
1084		/* NOTE:  skb_shinfos are recursive. Although IP returns
1085		 * skb's with only 1 level of fragments, SCTP reassembly can
1086		 * increase the levels.
1087		 */
1088		sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
1089	}
1090
1091done:
1092	sctp_assoc_rwnd_increase(event->asoc, len);
1093	sctp_chunk_put(event->chunk);
1094	sctp_ulpevent_release_owner(event);
1095}
1096
1097static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event)
1098{
1099	struct sk_buff *skb, *frag;
1100
1101	skb = sctp_event2skb(event);
1102
1103	if (!skb->data_len)
1104		goto done;
1105
1106	/* Don't forget the fragments. */
1107	skb_walk_frags(skb, frag) {
1108		/* NOTE:  skb_shinfos are recursive. Although IP returns
1109		 * skb's with only 1 level of fragments, SCTP reassembly can
1110		 * increase the levels.
1111		 */
1112		sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
1113	}
1114
1115done:
1116	sctp_chunk_put(event->chunk);
1117	sctp_ulpevent_release_owner(event);
1118}
1119
1120/* Free a ulpevent that has an owner.  It includes releasing the reference
1121 * to the owner, updating the rwnd in case of a DATA event and freeing the
1122 * skb.
1123 */
1124void sctp_ulpevent_free(struct sctp_ulpevent *event)
1125{
1126	if (sctp_ulpevent_is_notification(event))
1127		sctp_ulpevent_release_owner(event);
1128	else
1129		sctp_ulpevent_release_data(event);
1130
1131	kfree_skb(sctp_event2skb(event));
1132}
1133
1134/* Purge the skb lists holding ulpevents. */
1135unsigned int sctp_queue_purge_ulpevents(struct sk_buff_head *list)
1136{
1137	struct sk_buff *skb;
1138	unsigned int data_unread = 0;
1139
1140	while ((skb = skb_dequeue(list)) != NULL) {
1141		struct sctp_ulpevent *event = sctp_skb2event(skb);
1142
1143		if (!sctp_ulpevent_is_notification(event))
1144			data_unread += skb->len;
1145
1146		sctp_ulpevent_free(event);
1147	}
1148
1149	return data_unread;
1150}