root/net/sctp/ulpevent.c

DEFINITIONS

1. sctp_ulpevent_init
2. sctp_ulpevent_new
3. sctp_ulpevent_is_notification
4. sctp_ulpevent_set_owner
5. sctp_ulpevent_release_owner
6. sctp_ulpevent_make_assoc_change
7. sctp_ulpevent_make_peer_addr_change
8. sctp_ulpevent_make_remote_error
9. sctp_ulpevent_make_send_failed
10. sctp_ulpevent_make_shutdown_event
11. sctp_ulpevent_make_adaptation_indication
12. sctp_ulpevent_make_rcvmsg
13. sctp_ulpevent_make_pdapi
14. sctp_ulpevent_make_authkey
15. sctp_ulpevent_make_sender_dry_event
16. sctp_ulpevent_make_stream_reset_event
17. sctp_ulpevent_make_assoc_reset_event
18. sctp_ulpevent_make_stream_change_event
19. sctp_ulpevent_get_notification_type
20. sctp_ulpevent_read_sndrcvinfo
21. sctp_ulpevent_read_rcvinfo
22. __sctp_ulpevent_read_nxtinfo
23. sctp_ulpevent_read_nxtinfo
24. sctp_ulpevent_receive_data
25. sctp_ulpevent_release_data
26. sctp_ulpevent_release_frag_data
27. sctp_ulpevent_free
28. sctp_queue_purge_ulpevents

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