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