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			       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.  */
  63static 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
  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 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. */
 107static 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 */
 126struct 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
 243fail:
 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 */
 255struct 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_v4map(
 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 *sctp_ulpevent_make_remote_error(
 370	const struct sctp_association *asoc, struct sctp_chunk *chunk,
 371	__u16 flags, gfp_t gfp)
 
 372{
 373	struct sctp_ulpevent *event;
 374	struct sctp_remote_error *sre;
 375	struct sk_buff *skb;
 376	sctp_errhdr_t *ch;
 377	__be16 cause;
 378	int elen;
 379
 380	ch = (sctp_errhdr_t *)(chunk->skb->data);
 381	cause = ch->cause;
 382	elen = WORD_ROUND(ntohs(ch->length)) - sizeof(sctp_errhdr_t);
 383
 384	/* Pull off the ERROR header.  */
 385	skb_pull(chunk->skb, sizeof(sctp_errhdr_t));
 386
 387	/* Copy the skb to a new skb with room for us to prepend
 388	 * notification with.
 389	 */
 390	skb = skb_copy_expand(chunk->skb, sizeof(struct sctp_remote_error),
 391			      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 *)
 403		skb_push(skb, sizeof(struct sctp_remote_error));
 404
 405	/* Trim the buffer to the right length.  */
 406	skb_trim(skb, sizeof(struct sctp_remote_error) + elen);
 407
 408	/* Socket Extensions for SCTP
 409	 * 5.3.1.3 SCTP_REMOTE_ERROR
 410	 *
 411	 * sre_type:
 412	 *   It should be SCTP_REMOTE_ERROR.
 413	 */
 414	sre->sre_type = SCTP_REMOTE_ERROR;
 415
 416	/*
 417	 * Socket Extensions for SCTP
 418	 * 5.3.1.3 SCTP_REMOTE_ERROR
 419	 *
 420	 * sre_flags: 16 bits (unsigned integer)
 421	 *   Currently unused.
 422	 */
 423	sre->sre_flags = 0;
 424
 425	/* Socket Extensions for SCTP
 426	 * 5.3.1.3 SCTP_REMOTE_ERROR
 427	 *
 428	 * sre_length: sizeof (__u32)
 429	 *
 430	 * This field is the total length of the notification data,
 431	 * including the notification header.
 432	 */
 433	sre->sre_length = skb->len;
 434
 435	/* Socket Extensions for SCTP
 436	 * 5.3.1.3 SCTP_REMOTE_ERROR
 437	 *
 438	 * sre_error: 16 bits (unsigned integer)
 439	 * This value represents one of the Operational Error causes defined in
 440	 * the SCTP specification, in network byte order.
 441	 */
 442	sre->sre_error = cause;
 443
 444	/* Socket Extensions for SCTP
 445	 * 5.3.1.3 SCTP_REMOTE_ERROR
 446	 *
 447	 * sre_assoc_id: sizeof (sctp_assoc_t)
 448	 *
 449	 * The association id field, holds the identifier for the association.
 450	 * All notifications for a given association have the same association
 451	 * identifier.  For TCP style socket, this field is ignored.
 452	 */
 453	sctp_ulpevent_set_owner(event, asoc);
 454	sre->sre_assoc_id = sctp_assoc2id(asoc);
 455
 456	return event;
 457
 458fail:
 459	return NULL;
 460}
 461
 462/* Create and initialize a SCTP_SEND_FAILED notification.
 463 *
 464 * Socket Extensions for SCTP - draft-01
 465 * 5.3.1.4 SCTP_SEND_FAILED
 466 */
 467struct sctp_ulpevent *sctp_ulpevent_make_send_failed(
 468	const struct sctp_association *asoc, struct sctp_chunk *chunk,
 469	__u16 flags, __u32 error, gfp_t gfp)
 470{
 471	struct sctp_ulpevent *event;
 472	struct sctp_send_failed *ssf;
 473	struct sk_buff *skb;
 474
 475	/* Pull off any padding. */
 476	int len = ntohs(chunk->chunk_hdr->length);
 477
 478	/* Make skb with more room so we can prepend notification.  */
 479	skb = skb_copy_expand(chunk->skb,
 480			      sizeof(struct sctp_send_failed), /* headroom */
 481			      0,                               /* tailroom */
 482			      gfp);
 483	if (!skb)
 484		goto fail;
 485
 486	/* Pull off the common chunk header and DATA header.  */
 487	skb_pull(skb, sizeof(struct sctp_data_chunk));
 488	len -= sizeof(struct sctp_data_chunk);
 489
 490	/* Embed the event fields inside the cloned skb.  */
 491	event = sctp_skb2event(skb);
 492	sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
 493
 494	ssf = (struct sctp_send_failed *)
 495		skb_push(skb, sizeof(struct sctp_send_failed));
 496
 497	/* Socket Extensions for SCTP
 498	 * 5.3.1.4 SCTP_SEND_FAILED
 499	 *
 500	 * ssf_type:
 501	 * It should be SCTP_SEND_FAILED.
 502	 */
 503	ssf->ssf_type = SCTP_SEND_FAILED;
 504
 505	/* Socket Extensions for SCTP
 506	 * 5.3.1.4 SCTP_SEND_FAILED
 507	 *
 508	 * ssf_flags: 16 bits (unsigned integer)
 509	 * The flag value will take one of the following values
 510	 *
 511	 * SCTP_DATA_UNSENT - Indicates that the data was never put on
 512	 *                    the wire.
 513	 *
 514	 * SCTP_DATA_SENT   - Indicates that the data was put on the wire.
 515	 *                    Note that this does not necessarily mean that the
 516	 *                    data was (or was not) successfully delivered.
 517	 */
 518	ssf->ssf_flags = flags;
 519
 520	/* Socket Extensions for SCTP
 521	 * 5.3.1.4 SCTP_SEND_FAILED
 522	 *
 523	 * ssf_length: sizeof (__u32)
 524	 * This field is the total length of the notification data, including
 525	 * the notification header.
 526	 */
 527	ssf->ssf_length = sizeof(struct sctp_send_failed) + len;
 528	skb_trim(skb, ssf->ssf_length);
 529
 530	/* Socket Extensions for SCTP
 531	 * 5.3.1.4 SCTP_SEND_FAILED
 532	 *
 533	 * ssf_error: 16 bits (unsigned integer)
 534	 * This value represents the reason why the send failed, and if set,
 535	 * will be a SCTP protocol error code as defined in [SCTP] section
 536	 * 3.3.10.
 537	 */
 538	ssf->ssf_error = error;
 539
 540	/* Socket Extensions for SCTP
 541	 * 5.3.1.4 SCTP_SEND_FAILED
 542	 *
 543	 * ssf_info: sizeof (struct sctp_sndrcvinfo)
 544	 * The original send information associated with the undelivered
 545	 * message.
 546	 */
 547	memcpy(&ssf->ssf_info, &chunk->sinfo, sizeof(struct sctp_sndrcvinfo));
 548
 549	/* Per TSVWG discussion with Randy. Allow the application to
 550	 * reassemble a fragmented message.
 551	 */
 552	ssf->ssf_info.sinfo_flags = chunk->chunk_hdr->flags;
 553
 554	/* Socket Extensions for SCTP
 555	 * 5.3.1.4 SCTP_SEND_FAILED
 556	 *
 557	 * ssf_assoc_id: sizeof (sctp_assoc_t)
 558	 * The association id field, sf_assoc_id, holds the identifier for the
 559	 * association.  All notifications for a given association have the
 560	 * same association identifier.  For TCP style socket, this field is
 561	 * ignored.
 562	 */
 563	sctp_ulpevent_set_owner(event, asoc);
 564	ssf->ssf_assoc_id = sctp_assoc2id(asoc);
 565	return event;
 566
 567fail:
 568	return NULL;
 569}
 570
 571/* Create and initialize a SCTP_SHUTDOWN_EVENT notification.
 572 *
 573 * Socket Extensions for SCTP - draft-01
 574 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
 575 */
 576struct sctp_ulpevent *sctp_ulpevent_make_shutdown_event(
 577	const struct sctp_association *asoc,
 578	__u16 flags, gfp_t gfp)
 579{
 580	struct sctp_ulpevent *event;
 581	struct sctp_shutdown_event *sse;
 582	struct sk_buff *skb;
 583
 584	event = sctp_ulpevent_new(sizeof(struct sctp_shutdown_event),
 585				  MSG_NOTIFICATION, gfp);
 586	if (!event)
 587		goto fail;
 588
 589	skb = sctp_event2skb(event);
 590	sse = (struct sctp_shutdown_event *)
 591		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 = (struct sctp_adaptation_event *)
 654		skb_put(skb, sizeof(struct sctp_adaptation_event));
 655
 656	sai->sai_type = SCTP_ADAPTATION_INDICATION;
 657	sai->sai_flags = 0;
 658	sai->sai_length = sizeof(struct sctp_adaptation_event);
 659	sai->sai_adaptation_ind = asoc->peer.adaptation_ind;
 660	sctp_ulpevent_set_owner(event, asoc);
 661	sai->sai_assoc_id = sctp_assoc2id(asoc);
 662
 663	return event;
 664
 665fail:
 666	return NULL;
 667}
 668
 669/* A message has been received.  Package this message as a notification
 670 * to pass it to the upper layers.  Go ahead and calculate the sndrcvinfo
 671 * even if filtered out later.
 672 *
 673 * Socket Extensions for SCTP
 674 * 5.2.2 SCTP Header Information Structure (SCTP_SNDRCV)
 675 */
 676struct sctp_ulpevent *sctp_ulpevent_make_rcvmsg(struct sctp_association *asoc,
 677						struct sctp_chunk *chunk,
 678						gfp_t gfp)
 679{
 680	struct sctp_ulpevent *event = NULL;
 681	struct sk_buff *skb;
 682	size_t padding, len;
 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(&asoc->base.sk->sk_rmem_alloc);
 694
 695	if (rx_count >= asoc->base.sk->sk_rcvbuf) {
 696
 697		if ((asoc->base.sk->sk_userlocks & SOCK_RCVBUF_LOCK) ||
 698		    (!sk_rmem_schedule(asoc->base.sk, chunk->skb,
 699				       chunk->skb->truesize)))
 700			goto fail;
 701	}
 702
 703	/* Clone the original skb, sharing the data.  */
 704	skb = skb_clone(chunk->skb, gfp);
 705	if (!skb)
 706		goto fail;
 707
 708	/* Now that all memory allocations for this chunk succeeded, we
 709	 * can mark it as received so the tsn_map is updated correctly.
 710	 */
 711	if (sctp_tsnmap_mark(&asoc->peer.tsn_map,
 712			     ntohl(chunk->subh.data_hdr->tsn),
 713			     chunk->transport))
 714		goto fail_mark;
 715
 716	/* First calculate the padding, so we don't inadvertently
 717	 * pass up the wrong length to the user.
 718	 *
 719	 * RFC 2960 - Section 3.2  Chunk Field Descriptions
 720	 *
 721	 * The total length of a chunk(including Type, Length and Value fields)
 722	 * MUST be a multiple of 4 bytes.  If the length of the chunk is not a
 723	 * multiple of 4 bytes, the sender MUST pad the chunk with all zero
 724	 * bytes and this padding is not included in the chunk length field.
 725	 * The sender should never pad with more than 3 bytes.  The receiver
 726	 * MUST ignore the padding bytes.
 727	 */
 728	len = ntohs(chunk->chunk_hdr->length);
 729	padding = WORD_ROUND(len) - len;
 730
 731	/* Fixup cloned skb with just this chunks data.  */
 732	skb_trim(skb, chunk->chunk_end - padding - skb->data);
 733
 734	/* Embed the event fields inside the cloned skb.  */
 735	event = sctp_skb2event(skb);
 736
 737	/* Initialize event with flags 0  and correct length
 738	 * Since this is a clone of the original skb, only account for
 739	 * the data of this chunk as other chunks will be accounted separately.
 740	 */
 741	sctp_ulpevent_init(event, 0, skb->len + sizeof(struct sk_buff));
 742
 743	sctp_ulpevent_receive_data(event, asoc);
 744
 745	event->stream = ntohs(chunk->subh.data_hdr->stream);
 746	event->ssn = ntohs(chunk->subh.data_hdr->ssn);
 747	event->ppid = chunk->subh.data_hdr->ppid;
 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	event->iif = sctp_chunk_iif(chunk);
 755
 756	return event;
 757
 758fail_mark:
 759	kfree_skb(skb);
 760fail:
 761	return NULL;
 762}
 763
 764/* Create a partial delivery related event.
 765 *
 766 * 5.3.1.7 SCTP_PARTIAL_DELIVERY_EVENT
 767 *
 768 *   When a receiver is engaged in a partial delivery of a
 769 *   message this notification will be used to indicate
 770 *   various events.
 771 */
 772struct sctp_ulpevent *sctp_ulpevent_make_pdapi(
 773	const struct sctp_association *asoc, __u32 indication,
 774	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 = (struct sctp_pdapi_event *)
 787		skb_put(skb, sizeof(struct sctp_pdapi_event));
 788
 789	/* pdapi_type
 790	 *   It should be SCTP_PARTIAL_DELIVERY_EVENT
 791	 *
 792	 * pdapi_flags: 16 bits (unsigned integer)
 793	 *   Currently unused.
 794	 */
 795	pd->pdapi_type = SCTP_PARTIAL_DELIVERY_EVENT;
 796	pd->pdapi_flags = 0;
 797
 798	/* pdapi_length: 32 bits (unsigned integer)
 799	 *
 800	 * This field is the total length of the notification data, including
 801	 * the notification header.  It will generally be sizeof (struct
 802	 * sctp_pdapi_event).
 803	 */
 804	pd->pdapi_length = sizeof(struct sctp_pdapi_event);
 805
 806	/*  pdapi_indication: 32 bits (unsigned integer)
 807	 *
 808	 * This field holds the indication being sent to the application.
 809	 */
 810	pd->pdapi_indication = indication;
 811
 812	/*  pdapi_assoc_id: sizeof (sctp_assoc_t)
 813	 *
 814	 * The association id field, holds the identifier for the association.
 815	 */
 816	sctp_ulpevent_set_owner(event, asoc);
 817	pd->pdapi_assoc_id = sctp_assoc2id(asoc);
 818
 819	return event;
 820fail:
 821	return NULL;
 822}
 823
 824struct sctp_ulpevent *sctp_ulpevent_make_authkey(
 825	const struct sctp_association *asoc, __u16 key_id,
 826	__u32 indication, gfp_t gfp)
 827{
 828	struct sctp_ulpevent *event;
 829	struct sctp_authkey_event *ak;
 830	struct sk_buff *skb;
 831
 832	event = sctp_ulpevent_new(sizeof(struct sctp_authkey_event),
 833				  MSG_NOTIFICATION, gfp);
 834	if (!event)
 835		goto fail;
 836
 837	skb = sctp_event2skb(event);
 838	ak = (struct sctp_authkey_event *)
 839		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 = (struct sctp_sender_dry_event *)
 878		skb_put(skb, sizeof(struct sctp_sender_dry_event));
 879
 880	sdry->sender_dry_type = SCTP_SENDER_DRY_EVENT;
 881	sdry->sender_dry_flags = 0;
 882	sdry->sender_dry_length = sizeof(struct sctp_sender_dry_event);
 883	sctp_ulpevent_set_owner(event, asoc);
 884	sdry->sender_dry_assoc_id = sctp_assoc2id(asoc);
 885
 886	return event;
 887}
 888
 889/* Return the notification type, assuming this is a notification
 890 * event.
 891 */
 892__u16 sctp_ulpevent_get_notification_type(const struct sctp_ulpevent *event)
 893{
 894	union sctp_notification *notification;
 895	struct sk_buff *skb;
 896
 897	skb = sctp_event2skb(event);
 898	notification = (union sctp_notification *) skb->data;
 899	return notification->sn_header.sn_type;
 900}
 901
 902/* Copy out the sndrcvinfo into a msghdr.  */
 
 
 903void sctp_ulpevent_read_sndrcvinfo(const struct sctp_ulpevent *event,
 904				   struct msghdr *msghdr)
 905{
 906	struct sctp_sndrcvinfo sinfo;
 907
 908	if (sctp_ulpevent_is_notification(event))
 909		return;
 910
 911	/* Sockets API Extensions for SCTP
 912	 * Section 5.2.2 SCTP Header Information Structure (SCTP_SNDRCV)
 913	 *
 914	 * sinfo_stream: 16 bits (unsigned integer)
 915	 *
 916	 * For recvmsg() the SCTP stack places the message's stream number in
 917	 * this value.
 918	*/
 919	sinfo.sinfo_stream = event->stream;
 920	/* sinfo_ssn: 16 bits (unsigned integer)
 921	 *
 922	 * For recvmsg() this value contains the stream sequence number that
 923	 * the remote endpoint placed in the DATA chunk.  For fragmented
 924	 * messages this is the same number for all deliveries of the message
 925	 * (if more than one recvmsg() is needed to read the message).
 926	 */
 927	sinfo.sinfo_ssn = event->ssn;
 928	/* sinfo_ppid: 32 bits (unsigned integer)
 929	 *
 930	 * In recvmsg() this value is
 931	 * the same information that was passed by the upper layer in the peer
 932	 * application.  Please note that byte order issues are NOT accounted
 933	 * for and this information is passed opaquely by the SCTP stack from
 934	 * one end to the other.
 935	 */
 936	sinfo.sinfo_ppid = event->ppid;
 937	/* sinfo_flags: 16 bits (unsigned integer)
 938	 *
 939	 * This field may contain any of the following flags and is composed of
 940	 * a bitwise OR of these values.
 941	 *
 942	 * recvmsg() flags:
 943	 *
 944	 * SCTP_UNORDERED - This flag is present when the message was sent
 945	 *                 non-ordered.
 946	 */
 947	sinfo.sinfo_flags = event->flags;
 948	/* sinfo_tsn: 32 bit (unsigned integer)
 949	 *
 950	 * For the receiving side, this field holds a TSN that was
 951	 * assigned to one of the SCTP Data Chunks.
 952	 */
 953	sinfo.sinfo_tsn = event->tsn;
 954	/* sinfo_cumtsn: 32 bit (unsigned integer)
 955	 *
 956	 * This field will hold the current cumulative TSN as
 957	 * known by the underlying SCTP layer.  Note this field is
 958	 * ignored when sending and only valid for a receive
 959	 * operation when sinfo_flags are set to SCTP_UNORDERED.
 960	 */
 961	sinfo.sinfo_cumtsn = event->cumtsn;
 962	/* sinfo_assoc_id: sizeof (sctp_assoc_t)
 963	 *
 964	 * The association handle field, sinfo_assoc_id, holds the identifier
 965	 * for the association announced in the COMMUNICATION_UP notification.
 966	 * All notifications for a given association have the same identifier.
 967	 * Ignored for one-to-one style sockets.
 968	 */
 969	sinfo.sinfo_assoc_id = sctp_assoc2id(event->asoc);
 970
 971	/* context value that is set via SCTP_CONTEXT socket option. */
 972	sinfo.sinfo_context = event->asoc->default_rcv_context;
 973
 974	/* These fields are not used while receiving. */
 975	sinfo.sinfo_timetolive = 0;
 976
 977	put_cmsg(msghdr, IPPROTO_SCTP, SCTP_SNDRCV,
 978		 sizeof(struct sctp_sndrcvinfo), (void *)&sinfo);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 979}
 980
 981/* Do accounting for bytes received and hold a reference to the association
 982 * for each skb.
 983 */
 984static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
 985				       struct sctp_association *asoc)
 986{
 987	struct sk_buff *skb, *frag;
 988
 989	skb = sctp_event2skb(event);
 990	/* Set the owner and charge rwnd for bytes received.  */
 991	sctp_ulpevent_set_owner(event, asoc);
 992	sctp_assoc_rwnd_decrease(asoc, skb_headlen(skb));
 993
 994	if (!skb->data_len)
 995		return;
 996
 997	/* Note:  Not clearing the entire event struct as this is just a
 998	 * fragment of the real event.  However, we still need to do rwnd
 999	 * accounting.
1000	 * In general, the skb passed from IP can have only 1 level of
1001	 * fragments. But we allow multiple levels of fragments.
1002	 */
1003	skb_walk_frags(skb, frag)
1004		sctp_ulpevent_receive_data(sctp_skb2event(frag), asoc);
1005}
1006
1007/* Do accounting for bytes just read by user and release the references to
1008 * the association.
1009 */
1010static void sctp_ulpevent_release_data(struct sctp_ulpevent *event)
1011{
1012	struct sk_buff *skb, *frag;
1013	unsigned int	len;
1014
1015	/* Current stack structures assume that the rcv buffer is
1016	 * per socket.   For UDP style sockets this is not true as
1017	 * multiple associations may be on a single UDP-style socket.
1018	 * Use the local private area of the skb to track the owning
1019	 * association.
1020	 */
1021
1022	skb = sctp_event2skb(event);
1023	len = skb->len;
1024
1025	if (!skb->data_len)
1026		goto done;
1027
1028	/* Don't forget the fragments. */
1029	skb_walk_frags(skb, frag) {
1030		/* NOTE:  skb_shinfos are recursive. Although IP returns
1031		 * skb's with only 1 level of fragments, SCTP reassembly can
1032		 * increase the levels.
1033		 */
1034		sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
1035	}
1036
1037done:
1038	sctp_assoc_rwnd_increase(event->asoc, len);
1039	sctp_ulpevent_release_owner(event);
1040}
1041
1042static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event)
1043{
1044	struct sk_buff *skb, *frag;
1045
1046	skb = sctp_event2skb(event);
1047
1048	if (!skb->data_len)
1049		goto done;
1050
1051	/* Don't forget the fragments. */
1052	skb_walk_frags(skb, frag) {
1053		/* NOTE:  skb_shinfos are recursive. Although IP returns
1054		 * skb's with only 1 level of fragments, SCTP reassembly can
1055		 * increase the levels.
1056		 */
1057		sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
1058	}
1059
1060done:
1061	sctp_ulpevent_release_owner(event);
1062}
1063
1064/* Free a ulpevent that has an owner.  It includes releasing the reference
1065 * to the owner, updating the rwnd in case of a DATA event and freeing the
1066 * skb.
1067 */
1068void sctp_ulpevent_free(struct sctp_ulpevent *event)
1069{
1070	if (sctp_ulpevent_is_notification(event))
1071		sctp_ulpevent_release_owner(event);
1072	else
1073		sctp_ulpevent_release_data(event);
1074
1075	kfree_skb(sctp_event2skb(event));
1076}
1077
1078/* Purge the skb lists holding ulpevents. */
1079unsigned int sctp_queue_purge_ulpevents(struct sk_buff_head *list)
1080{
1081	struct sk_buff *skb;
1082	unsigned int data_unread = 0;
1083
1084	while ((skb = skb_dequeue(list)) != NULL) {
1085		struct sctp_ulpevent *event = sctp_skb2event(skb);
1086
1087		if (!sctp_ulpevent_is_notification(event))
1088			data_unread += skb->len;
1089
1090		sctp_ulpevent_free(event);
1091	}
1092
1093	return data_unread;
1094}