Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* SCTP kernel reference 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 | * This abstraction carries sctp events to the ULP (sockets). |
| 10 | * |
| 11 | * The SCTP reference implementation is free software; |
| 12 | * you can redistribute it and/or modify it under the terms of |
| 13 | * the GNU General Public License as published by |
| 14 | * the Free Software Foundation; either version 2, or (at your option) |
| 15 | * any later version. |
| 16 | * |
| 17 | * The SCTP reference implementation is distributed in the hope that it |
| 18 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
| 19 | * ************************ |
| 20 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 21 | * See the GNU General Public License for more details. |
| 22 | * |
| 23 | * You should have received a copy of the GNU General Public License |
| 24 | * along with GNU CC; see the file COPYING. If not, write to |
| 25 | * the Free Software Foundation, 59 Temple Place - Suite 330, |
| 26 | * Boston, MA 02111-1307, USA. |
| 27 | * |
| 28 | * Please send any bug reports or fixes you make to the |
| 29 | * email address(es): |
| 30 | * lksctp developers <lksctp-developers@lists.sourceforge.net> |
| 31 | * |
| 32 | * Or submit a bug report through the following website: |
| 33 | * http://www.sf.net/projects/lksctp |
| 34 | * |
| 35 | * Written or modified by: |
| 36 | * Jon Grimm <jgrimm@us.ibm.com> |
| 37 | * La Monte H.P. Yarroll <piggy@acm.org> |
| 38 | * Sridhar Samudrala <sri@us.ibm.com> |
| 39 | * |
| 40 | * Any bugs reported given to us we will try to fix... any fixes shared will |
| 41 | * be incorporated into the next SCTP release. |
| 42 | */ |
| 43 | |
| 44 | #include <linux/types.h> |
| 45 | #include <linux/skbuff.h> |
| 46 | #include <net/sock.h> |
| 47 | #include <net/sctp/structs.h> |
| 48 | #include <net/sctp/sctp.h> |
| 49 | #include <net/sctp/sm.h> |
| 50 | |
| 51 | /* Forward declarations for internal helpers. */ |
| 52 | static struct sctp_ulpevent * sctp_ulpq_reasm(struct sctp_ulpq *ulpq, |
| 53 | struct sctp_ulpevent *); |
| 54 | static struct sctp_ulpevent * sctp_ulpq_order(struct sctp_ulpq *, |
| 55 | struct sctp_ulpevent *); |
| 56 | |
| 57 | /* 1st Level Abstractions */ |
| 58 | |
| 59 | /* Initialize a ULP queue from a block of memory. */ |
| 60 | struct sctp_ulpq *sctp_ulpq_init(struct sctp_ulpq *ulpq, |
| 61 | struct sctp_association *asoc) |
| 62 | { |
| 63 | memset(ulpq, 0, sizeof(struct sctp_ulpq)); |
| 64 | |
| 65 | ulpq->asoc = asoc; |
| 66 | skb_queue_head_init(&ulpq->reasm); |
| 67 | skb_queue_head_init(&ulpq->lobby); |
| 68 | ulpq->pd_mode = 0; |
| 69 | ulpq->malloced = 0; |
| 70 | |
| 71 | return ulpq; |
| 72 | } |
| 73 | |
| 74 | |
| 75 | /* Flush the reassembly and ordering queues. */ |
| 76 | static void sctp_ulpq_flush(struct sctp_ulpq *ulpq) |
| 77 | { |
| 78 | struct sk_buff *skb; |
| 79 | struct sctp_ulpevent *event; |
| 80 | |
| 81 | while ((skb = __skb_dequeue(&ulpq->lobby)) != NULL) { |
| 82 | event = sctp_skb2event(skb); |
| 83 | sctp_ulpevent_free(event); |
| 84 | } |
| 85 | |
| 86 | while ((skb = __skb_dequeue(&ulpq->reasm)) != NULL) { |
| 87 | event = sctp_skb2event(skb); |
| 88 | sctp_ulpevent_free(event); |
| 89 | } |
| 90 | |
| 91 | } |
| 92 | |
| 93 | /* Dispose of a ulpqueue. */ |
| 94 | void sctp_ulpq_free(struct sctp_ulpq *ulpq) |
| 95 | { |
| 96 | sctp_ulpq_flush(ulpq); |
| 97 | if (ulpq->malloced) |
| 98 | kfree(ulpq); |
| 99 | } |
| 100 | |
| 101 | /* Process an incoming DATA chunk. */ |
| 102 | int sctp_ulpq_tail_data(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, |
Alexey Dobriyan | 3182cd84 | 2005-07-11 20:57:47 -0700 | [diff] [blame^] | 103 | unsigned int __nocast gfp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | { |
| 105 | struct sk_buff_head temp; |
| 106 | sctp_data_chunk_t *hdr; |
| 107 | struct sctp_ulpevent *event; |
| 108 | |
| 109 | hdr = (sctp_data_chunk_t *) chunk->chunk_hdr; |
| 110 | |
| 111 | /* Create an event from the incoming chunk. */ |
| 112 | event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp); |
| 113 | if (!event) |
| 114 | return -ENOMEM; |
| 115 | |
| 116 | /* Do reassembly if needed. */ |
| 117 | event = sctp_ulpq_reasm(ulpq, event); |
| 118 | |
| 119 | /* Do ordering if needed. */ |
| 120 | if ((event) && (event->msg_flags & MSG_EOR)){ |
| 121 | /* Create a temporary list to collect chunks on. */ |
| 122 | skb_queue_head_init(&temp); |
| 123 | __skb_queue_tail(&temp, sctp_event2skb(event)); |
| 124 | |
| 125 | event = sctp_ulpq_order(ulpq, event); |
| 126 | } |
| 127 | |
| 128 | /* Send event to the ULP. */ |
| 129 | if (event) |
| 130 | sctp_ulpq_tail_event(ulpq, event); |
| 131 | |
| 132 | return 0; |
| 133 | } |
| 134 | |
| 135 | /* Add a new event for propagation to the ULP. */ |
| 136 | /* Clear the partial delivery mode for this socket. Note: This |
| 137 | * assumes that no association is currently in partial delivery mode. |
| 138 | */ |
| 139 | int sctp_clear_pd(struct sock *sk) |
| 140 | { |
| 141 | struct sctp_sock *sp = sctp_sk(sk); |
| 142 | |
| 143 | sp->pd_mode = 0; |
| 144 | if (!skb_queue_empty(&sp->pd_lobby)) { |
| 145 | struct list_head *list; |
| 146 | sctp_skb_list_tail(&sp->pd_lobby, &sk->sk_receive_queue); |
| 147 | list = (struct list_head *)&sctp_sk(sk)->pd_lobby; |
| 148 | INIT_LIST_HEAD(list); |
| 149 | return 1; |
| 150 | } |
| 151 | return 0; |
| 152 | } |
| 153 | |
| 154 | /* Clear the pd_mode and restart any pending messages waiting for delivery. */ |
| 155 | static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq) |
| 156 | { |
| 157 | ulpq->pd_mode = 0; |
| 158 | return sctp_clear_pd(ulpq->asoc->base.sk); |
| 159 | } |
| 160 | |
| 161 | |
| 162 | |
| 163 | int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event) |
| 164 | { |
| 165 | struct sock *sk = ulpq->asoc->base.sk; |
| 166 | struct sk_buff_head *queue; |
| 167 | int clear_pd = 0; |
| 168 | |
| 169 | /* If the socket is just going to throw this away, do not |
| 170 | * even try to deliver it. |
| 171 | */ |
| 172 | if (sock_flag(sk, SOCK_DEAD) || (sk->sk_shutdown & RCV_SHUTDOWN)) |
| 173 | goto out_free; |
| 174 | |
| 175 | /* Check if the user wishes to receive this event. */ |
| 176 | if (!sctp_ulpevent_is_enabled(event, &sctp_sk(sk)->subscribe)) |
| 177 | goto out_free; |
| 178 | |
| 179 | /* If we are in partial delivery mode, post to the lobby until |
| 180 | * partial delivery is cleared, unless, of course _this_ is |
| 181 | * the association the cause of the partial delivery. |
| 182 | */ |
| 183 | |
| 184 | if (!sctp_sk(sk)->pd_mode) { |
| 185 | queue = &sk->sk_receive_queue; |
| 186 | } else if (ulpq->pd_mode) { |
| 187 | if (event->msg_flags & MSG_NOTIFICATION) |
| 188 | queue = &sctp_sk(sk)->pd_lobby; |
| 189 | else { |
| 190 | clear_pd = event->msg_flags & MSG_EOR; |
| 191 | queue = &sk->sk_receive_queue; |
| 192 | } |
| 193 | } else |
| 194 | queue = &sctp_sk(sk)->pd_lobby; |
| 195 | |
| 196 | |
| 197 | /* If we are harvesting multiple skbs they will be |
| 198 | * collected on a list. |
| 199 | */ |
| 200 | if (sctp_event2skb(event)->list) |
| 201 | sctp_skb_list_tail(sctp_event2skb(event)->list, queue); |
| 202 | else |
| 203 | __skb_queue_tail(queue, sctp_event2skb(event)); |
| 204 | |
| 205 | /* Did we just complete partial delivery and need to get |
| 206 | * rolling again? Move pending data to the receive |
| 207 | * queue. |
| 208 | */ |
| 209 | if (clear_pd) |
| 210 | sctp_ulpq_clear_pd(ulpq); |
| 211 | |
| 212 | if (queue == &sk->sk_receive_queue) |
| 213 | sk->sk_data_ready(sk, 0); |
| 214 | return 1; |
| 215 | |
| 216 | out_free: |
| 217 | if (sctp_event2skb(event)->list) |
| 218 | sctp_queue_purge_ulpevents(sctp_event2skb(event)->list); |
| 219 | else |
| 220 | sctp_ulpevent_free(event); |
| 221 | return 0; |
| 222 | } |
| 223 | |
| 224 | /* 2nd Level Abstractions */ |
| 225 | |
| 226 | /* Helper function to store chunks that need to be reassembled. */ |
| 227 | static inline void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq, |
| 228 | struct sctp_ulpevent *event) |
| 229 | { |
| 230 | struct sk_buff *pos; |
| 231 | struct sctp_ulpevent *cevent; |
| 232 | __u32 tsn, ctsn; |
| 233 | |
| 234 | tsn = event->tsn; |
| 235 | |
| 236 | /* See if it belongs at the end. */ |
| 237 | pos = skb_peek_tail(&ulpq->reasm); |
| 238 | if (!pos) { |
| 239 | __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); |
| 240 | return; |
| 241 | } |
| 242 | |
| 243 | /* Short circuit just dropping it at the end. */ |
| 244 | cevent = sctp_skb2event(pos); |
| 245 | ctsn = cevent->tsn; |
| 246 | if (TSN_lt(ctsn, tsn)) { |
| 247 | __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); |
| 248 | return; |
| 249 | } |
| 250 | |
| 251 | /* Find the right place in this list. We store them by TSN. */ |
| 252 | skb_queue_walk(&ulpq->reasm, pos) { |
| 253 | cevent = sctp_skb2event(pos); |
| 254 | ctsn = cevent->tsn; |
| 255 | |
| 256 | if (TSN_lt(tsn, ctsn)) |
| 257 | break; |
| 258 | } |
| 259 | |
| 260 | /* Insert before pos. */ |
| 261 | __skb_insert(sctp_event2skb(event), pos->prev, pos, &ulpq->reasm); |
| 262 | |
| 263 | } |
| 264 | |
| 265 | /* Helper function to return an event corresponding to the reassembled |
| 266 | * datagram. |
| 267 | * This routine creates a re-assembled skb given the first and last skb's |
| 268 | * as stored in the reassembly queue. The skb's may be non-linear if the sctp |
| 269 | * payload was fragmented on the way and ip had to reassemble them. |
| 270 | * We add the rest of skb's to the first skb's fraglist. |
| 271 | */ |
| 272 | static struct sctp_ulpevent *sctp_make_reassembled_event(struct sk_buff *f_frag, struct sk_buff *l_frag) |
| 273 | { |
| 274 | struct sk_buff *pos; |
| 275 | struct sctp_ulpevent *event; |
| 276 | struct sk_buff *pnext, *last; |
| 277 | struct sk_buff *list = skb_shinfo(f_frag)->frag_list; |
| 278 | |
| 279 | /* Store the pointer to the 2nd skb */ |
| 280 | if (f_frag == l_frag) |
| 281 | pos = NULL; |
| 282 | else |
| 283 | pos = f_frag->next; |
| 284 | |
| 285 | /* Get the last skb in the f_frag's frag_list if present. */ |
| 286 | for (last = list; list; last = list, list = list->next); |
| 287 | |
| 288 | /* Add the list of remaining fragments to the first fragments |
| 289 | * frag_list. |
| 290 | */ |
| 291 | if (last) |
| 292 | last->next = pos; |
| 293 | else |
| 294 | skb_shinfo(f_frag)->frag_list = pos; |
| 295 | |
| 296 | /* Remove the first fragment from the reassembly queue. */ |
| 297 | __skb_unlink(f_frag, f_frag->list); |
| 298 | while (pos) { |
| 299 | |
| 300 | pnext = pos->next; |
| 301 | |
| 302 | /* Update the len and data_len fields of the first fragment. */ |
| 303 | f_frag->len += pos->len; |
| 304 | f_frag->data_len += pos->len; |
| 305 | |
| 306 | /* Remove the fragment from the reassembly queue. */ |
| 307 | __skb_unlink(pos, pos->list); |
| 308 | |
| 309 | /* Break if we have reached the last fragment. */ |
| 310 | if (pos == l_frag) |
| 311 | break; |
| 312 | pos->next = pnext; |
| 313 | pos = pnext; |
| 314 | }; |
| 315 | |
| 316 | event = sctp_skb2event(f_frag); |
| 317 | SCTP_INC_STATS(SCTP_MIB_REASMUSRMSGS); |
| 318 | |
| 319 | return event; |
| 320 | } |
| 321 | |
| 322 | |
| 323 | /* Helper function to check if an incoming chunk has filled up the last |
| 324 | * missing fragment in a SCTP datagram and return the corresponding event. |
| 325 | */ |
| 326 | static inline struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq) |
| 327 | { |
| 328 | struct sk_buff *pos; |
| 329 | struct sctp_ulpevent *cevent; |
| 330 | struct sk_buff *first_frag = NULL; |
| 331 | __u32 ctsn, next_tsn; |
| 332 | struct sctp_ulpevent *retval = NULL; |
| 333 | |
| 334 | /* Initialized to 0 just to avoid compiler warning message. Will |
| 335 | * never be used with this value. It is referenced only after it |
| 336 | * is set when we find the first fragment of a message. |
| 337 | */ |
| 338 | next_tsn = 0; |
| 339 | |
| 340 | /* The chunks are held in the reasm queue sorted by TSN. |
| 341 | * Walk through the queue sequentially and look for a sequence of |
| 342 | * fragmented chunks that complete a datagram. |
| 343 | * 'first_frag' and next_tsn are reset when we find a chunk which |
| 344 | * is the first fragment of a datagram. Once these 2 fields are set |
| 345 | * we expect to find the remaining middle fragments and the last |
| 346 | * fragment in order. If not, first_frag is reset to NULL and we |
| 347 | * start the next pass when we find another first fragment. |
| 348 | */ |
| 349 | skb_queue_walk(&ulpq->reasm, pos) { |
| 350 | cevent = sctp_skb2event(pos); |
| 351 | ctsn = cevent->tsn; |
| 352 | |
| 353 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { |
| 354 | case SCTP_DATA_FIRST_FRAG: |
| 355 | first_frag = pos; |
| 356 | next_tsn = ctsn + 1; |
| 357 | break; |
| 358 | |
| 359 | case SCTP_DATA_MIDDLE_FRAG: |
| 360 | if ((first_frag) && (ctsn == next_tsn)) |
| 361 | next_tsn++; |
| 362 | else |
| 363 | first_frag = NULL; |
| 364 | break; |
| 365 | |
| 366 | case SCTP_DATA_LAST_FRAG: |
| 367 | if (first_frag && (ctsn == next_tsn)) |
| 368 | goto found; |
| 369 | else |
| 370 | first_frag = NULL; |
| 371 | break; |
| 372 | }; |
| 373 | |
| 374 | } |
| 375 | done: |
| 376 | return retval; |
| 377 | found: |
| 378 | retval = sctp_make_reassembled_event(first_frag, pos); |
| 379 | if (retval) |
| 380 | retval->msg_flags |= MSG_EOR; |
| 381 | goto done; |
| 382 | } |
| 383 | |
| 384 | /* Retrieve the next set of fragments of a partial message. */ |
| 385 | static inline struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq) |
| 386 | { |
| 387 | struct sk_buff *pos, *last_frag, *first_frag; |
| 388 | struct sctp_ulpevent *cevent; |
| 389 | __u32 ctsn, next_tsn; |
| 390 | int is_last; |
| 391 | struct sctp_ulpevent *retval; |
| 392 | |
| 393 | /* The chunks are held in the reasm queue sorted by TSN. |
| 394 | * Walk through the queue sequentially and look for the first |
| 395 | * sequence of fragmented chunks. |
| 396 | */ |
| 397 | |
| 398 | if (skb_queue_empty(&ulpq->reasm)) |
| 399 | return NULL; |
| 400 | |
| 401 | last_frag = first_frag = NULL; |
| 402 | retval = NULL; |
| 403 | next_tsn = 0; |
| 404 | is_last = 0; |
| 405 | |
| 406 | skb_queue_walk(&ulpq->reasm, pos) { |
| 407 | cevent = sctp_skb2event(pos); |
| 408 | ctsn = cevent->tsn; |
| 409 | |
| 410 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { |
| 411 | case SCTP_DATA_MIDDLE_FRAG: |
| 412 | if (!first_frag) { |
| 413 | first_frag = pos; |
| 414 | next_tsn = ctsn + 1; |
| 415 | last_frag = pos; |
| 416 | } else if (next_tsn == ctsn) |
| 417 | next_tsn++; |
| 418 | else |
| 419 | goto done; |
| 420 | break; |
| 421 | case SCTP_DATA_LAST_FRAG: |
| 422 | if (!first_frag) |
| 423 | first_frag = pos; |
| 424 | else if (ctsn != next_tsn) |
| 425 | goto done; |
| 426 | last_frag = pos; |
| 427 | is_last = 1; |
| 428 | goto done; |
| 429 | default: |
| 430 | return NULL; |
| 431 | }; |
| 432 | } |
| 433 | |
| 434 | /* We have the reassembled event. There is no need to look |
| 435 | * further. |
| 436 | */ |
| 437 | done: |
| 438 | retval = sctp_make_reassembled_event(first_frag, last_frag); |
| 439 | if (retval && is_last) |
| 440 | retval->msg_flags |= MSG_EOR; |
| 441 | |
| 442 | return retval; |
| 443 | } |
| 444 | |
| 445 | |
| 446 | /* Helper function to reassemble chunks. Hold chunks on the reasm queue that |
| 447 | * need reassembling. |
| 448 | */ |
| 449 | static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq, |
| 450 | struct sctp_ulpevent *event) |
| 451 | { |
| 452 | struct sctp_ulpevent *retval = NULL; |
| 453 | |
| 454 | /* Check if this is part of a fragmented message. */ |
| 455 | if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) { |
| 456 | event->msg_flags |= MSG_EOR; |
| 457 | return event; |
| 458 | } |
| 459 | |
| 460 | sctp_ulpq_store_reasm(ulpq, event); |
| 461 | if (!ulpq->pd_mode) |
| 462 | retval = sctp_ulpq_retrieve_reassembled(ulpq); |
| 463 | else { |
| 464 | __u32 ctsn, ctsnap; |
| 465 | |
| 466 | /* Do not even bother unless this is the next tsn to |
| 467 | * be delivered. |
| 468 | */ |
| 469 | ctsn = event->tsn; |
| 470 | ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map); |
| 471 | if (TSN_lte(ctsn, ctsnap)) |
| 472 | retval = sctp_ulpq_retrieve_partial(ulpq); |
| 473 | } |
| 474 | |
| 475 | return retval; |
| 476 | } |
| 477 | |
| 478 | /* Retrieve the first part (sequential fragments) for partial delivery. */ |
| 479 | static inline struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq) |
| 480 | { |
| 481 | struct sk_buff *pos, *last_frag, *first_frag; |
| 482 | struct sctp_ulpevent *cevent; |
| 483 | __u32 ctsn, next_tsn; |
| 484 | struct sctp_ulpevent *retval; |
| 485 | |
| 486 | /* The chunks are held in the reasm queue sorted by TSN. |
| 487 | * Walk through the queue sequentially and look for a sequence of |
| 488 | * fragmented chunks that start a datagram. |
| 489 | */ |
| 490 | |
| 491 | if (skb_queue_empty(&ulpq->reasm)) |
| 492 | return NULL; |
| 493 | |
| 494 | last_frag = first_frag = NULL; |
| 495 | retval = NULL; |
| 496 | next_tsn = 0; |
| 497 | |
| 498 | skb_queue_walk(&ulpq->reasm, pos) { |
| 499 | cevent = sctp_skb2event(pos); |
| 500 | ctsn = cevent->tsn; |
| 501 | |
| 502 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { |
| 503 | case SCTP_DATA_FIRST_FRAG: |
| 504 | if (!first_frag) { |
| 505 | first_frag = pos; |
| 506 | next_tsn = ctsn + 1; |
| 507 | last_frag = pos; |
| 508 | } else |
| 509 | goto done; |
| 510 | break; |
| 511 | |
| 512 | case SCTP_DATA_MIDDLE_FRAG: |
| 513 | if (!first_frag) |
| 514 | return NULL; |
| 515 | if (ctsn == next_tsn) { |
| 516 | next_tsn++; |
| 517 | last_frag = pos; |
| 518 | } else |
| 519 | goto done; |
| 520 | break; |
| 521 | default: |
| 522 | return NULL; |
| 523 | }; |
| 524 | } |
| 525 | |
| 526 | /* We have the reassembled event. There is no need to look |
| 527 | * further. |
| 528 | */ |
| 529 | done: |
| 530 | retval = sctp_make_reassembled_event(first_frag, last_frag); |
| 531 | return retval; |
| 532 | } |
| 533 | |
| 534 | /* Helper function to gather skbs that have possibly become |
| 535 | * ordered by an an incoming chunk. |
| 536 | */ |
| 537 | static inline void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq, |
| 538 | struct sctp_ulpevent *event) |
| 539 | { |
| 540 | struct sk_buff *pos, *tmp; |
| 541 | struct sctp_ulpevent *cevent; |
| 542 | struct sctp_stream *in; |
| 543 | __u16 sid, csid; |
| 544 | __u16 ssn, cssn; |
| 545 | |
| 546 | sid = event->stream; |
| 547 | ssn = event->ssn; |
| 548 | in = &ulpq->asoc->ssnmap->in; |
| 549 | |
| 550 | /* We are holding the chunks by stream, by SSN. */ |
| 551 | sctp_skb_for_each(pos, &ulpq->lobby, tmp) { |
| 552 | cevent = (struct sctp_ulpevent *) pos->cb; |
| 553 | csid = cevent->stream; |
| 554 | cssn = cevent->ssn; |
| 555 | |
| 556 | /* Have we gone too far? */ |
| 557 | if (csid > sid) |
| 558 | break; |
| 559 | |
| 560 | /* Have we not gone far enough? */ |
| 561 | if (csid < sid) |
| 562 | continue; |
| 563 | |
| 564 | if (cssn != sctp_ssn_peek(in, sid)) |
| 565 | break; |
| 566 | |
| 567 | /* Found it, so mark in the ssnmap. */ |
| 568 | sctp_ssn_next(in, sid); |
| 569 | |
| 570 | __skb_unlink(pos, pos->list); |
| 571 | |
| 572 | /* Attach all gathered skbs to the event. */ |
| 573 | __skb_queue_tail(sctp_event2skb(event)->list, pos); |
| 574 | } |
| 575 | } |
| 576 | |
| 577 | /* Helper function to store chunks needing ordering. */ |
| 578 | static inline void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq, |
| 579 | struct sctp_ulpevent *event) |
| 580 | { |
| 581 | struct sk_buff *pos; |
| 582 | struct sctp_ulpevent *cevent; |
| 583 | __u16 sid, csid; |
| 584 | __u16 ssn, cssn; |
| 585 | |
| 586 | pos = skb_peek_tail(&ulpq->lobby); |
| 587 | if (!pos) { |
| 588 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); |
| 589 | return; |
| 590 | } |
| 591 | |
| 592 | sid = event->stream; |
| 593 | ssn = event->ssn; |
| 594 | |
| 595 | cevent = (struct sctp_ulpevent *) pos->cb; |
| 596 | csid = cevent->stream; |
| 597 | cssn = cevent->ssn; |
| 598 | if (sid > csid) { |
| 599 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); |
| 600 | return; |
| 601 | } |
| 602 | |
| 603 | if ((sid == csid) && SSN_lt(cssn, ssn)) { |
| 604 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); |
| 605 | return; |
| 606 | } |
| 607 | |
| 608 | /* Find the right place in this list. We store them by |
| 609 | * stream ID and then by SSN. |
| 610 | */ |
| 611 | skb_queue_walk(&ulpq->lobby, pos) { |
| 612 | cevent = (struct sctp_ulpevent *) pos->cb; |
| 613 | csid = cevent->stream; |
| 614 | cssn = cevent->ssn; |
| 615 | |
| 616 | if (csid > sid) |
| 617 | break; |
| 618 | if (csid == sid && SSN_lt(ssn, cssn)) |
| 619 | break; |
| 620 | } |
| 621 | |
| 622 | |
| 623 | /* Insert before pos. */ |
| 624 | __skb_insert(sctp_event2skb(event), pos->prev, pos, &ulpq->lobby); |
| 625 | |
| 626 | } |
| 627 | |
| 628 | static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq, |
| 629 | struct sctp_ulpevent *event) |
| 630 | { |
| 631 | __u16 sid, ssn; |
| 632 | struct sctp_stream *in; |
| 633 | |
| 634 | /* Check if this message needs ordering. */ |
| 635 | if (SCTP_DATA_UNORDERED & event->msg_flags) |
| 636 | return event; |
| 637 | |
| 638 | /* Note: The stream ID must be verified before this routine. */ |
| 639 | sid = event->stream; |
| 640 | ssn = event->ssn; |
| 641 | in = &ulpq->asoc->ssnmap->in; |
| 642 | |
| 643 | /* Is this the expected SSN for this stream ID? */ |
| 644 | if (ssn != sctp_ssn_peek(in, sid)) { |
| 645 | /* We've received something out of order, so find where it |
| 646 | * needs to be placed. We order by stream and then by SSN. |
| 647 | */ |
| 648 | sctp_ulpq_store_ordered(ulpq, event); |
| 649 | return NULL; |
| 650 | } |
| 651 | |
| 652 | /* Mark that the next chunk has been found. */ |
| 653 | sctp_ssn_next(in, sid); |
| 654 | |
| 655 | /* Go find any other chunks that were waiting for |
| 656 | * ordering. |
| 657 | */ |
| 658 | sctp_ulpq_retrieve_ordered(ulpq, event); |
| 659 | |
| 660 | return event; |
| 661 | } |
| 662 | |
| 663 | /* Helper function to gather skbs that have possibly become |
| 664 | * ordered by forward tsn skipping their dependencies. |
| 665 | */ |
| 666 | static inline void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq) |
| 667 | { |
| 668 | struct sk_buff *pos, *tmp; |
| 669 | struct sctp_ulpevent *cevent; |
| 670 | struct sctp_ulpevent *event = NULL; |
| 671 | struct sctp_stream *in; |
| 672 | struct sk_buff_head temp; |
| 673 | __u16 csid, cssn; |
| 674 | |
| 675 | in = &ulpq->asoc->ssnmap->in; |
| 676 | |
| 677 | /* We are holding the chunks by stream, by SSN. */ |
| 678 | sctp_skb_for_each(pos, &ulpq->lobby, tmp) { |
| 679 | cevent = (struct sctp_ulpevent *) pos->cb; |
| 680 | csid = cevent->stream; |
| 681 | cssn = cevent->ssn; |
| 682 | |
| 683 | if (cssn != sctp_ssn_peek(in, csid)) |
| 684 | break; |
| 685 | |
| 686 | /* Found it, so mark in the ssnmap. */ |
| 687 | sctp_ssn_next(in, csid); |
| 688 | |
| 689 | __skb_unlink(pos, pos->list); |
| 690 | if (!event) { |
| 691 | /* Create a temporary list to collect chunks on. */ |
| 692 | event = sctp_skb2event(pos); |
| 693 | skb_queue_head_init(&temp); |
| 694 | __skb_queue_tail(&temp, sctp_event2skb(event)); |
| 695 | } else { |
| 696 | /* Attach all gathered skbs to the event. */ |
| 697 | __skb_queue_tail(sctp_event2skb(event)->list, pos); |
| 698 | } |
| 699 | } |
| 700 | |
| 701 | /* Send event to the ULP. */ |
| 702 | if (event) |
| 703 | sctp_ulpq_tail_event(ulpq, event); |
| 704 | } |
| 705 | |
| 706 | /* Skip over an SSN. */ |
| 707 | void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn) |
| 708 | { |
| 709 | struct sctp_stream *in; |
| 710 | |
| 711 | /* Note: The stream ID must be verified before this routine. */ |
| 712 | in = &ulpq->asoc->ssnmap->in; |
| 713 | |
| 714 | /* Is this an old SSN? If so ignore. */ |
| 715 | if (SSN_lt(ssn, sctp_ssn_peek(in, sid))) |
| 716 | return; |
| 717 | |
| 718 | /* Mark that we are no longer expecting this SSN or lower. */ |
| 719 | sctp_ssn_skip(in, sid, ssn); |
| 720 | |
| 721 | /* Go find any other chunks that were waiting for |
| 722 | * ordering and deliver them if needed. |
| 723 | */ |
| 724 | sctp_ulpq_reap_ordered(ulpq); |
| 725 | return; |
| 726 | } |
| 727 | |
| 728 | /* Renege 'needed' bytes from the ordering queue. */ |
| 729 | static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed) |
| 730 | { |
| 731 | __u16 freed = 0; |
| 732 | __u32 tsn; |
| 733 | struct sk_buff *skb; |
| 734 | struct sctp_ulpevent *event; |
| 735 | struct sctp_tsnmap *tsnmap; |
| 736 | |
| 737 | tsnmap = &ulpq->asoc->peer.tsn_map; |
| 738 | |
| 739 | while ((skb = __skb_dequeue_tail(&ulpq->lobby)) != NULL) { |
| 740 | freed += skb_headlen(skb); |
| 741 | event = sctp_skb2event(skb); |
| 742 | tsn = event->tsn; |
| 743 | |
| 744 | sctp_ulpevent_free(event); |
| 745 | sctp_tsnmap_renege(tsnmap, tsn); |
| 746 | if (freed >= needed) |
| 747 | return freed; |
| 748 | } |
| 749 | |
| 750 | return freed; |
| 751 | } |
| 752 | |
| 753 | /* Renege 'needed' bytes from the reassembly queue. */ |
| 754 | static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed) |
| 755 | { |
| 756 | __u16 freed = 0; |
| 757 | __u32 tsn; |
| 758 | struct sk_buff *skb; |
| 759 | struct sctp_ulpevent *event; |
| 760 | struct sctp_tsnmap *tsnmap; |
| 761 | |
| 762 | tsnmap = &ulpq->asoc->peer.tsn_map; |
| 763 | |
| 764 | /* Walk backwards through the list, reneges the newest tsns. */ |
| 765 | while ((skb = __skb_dequeue_tail(&ulpq->reasm)) != NULL) { |
| 766 | freed += skb_headlen(skb); |
| 767 | event = sctp_skb2event(skb); |
| 768 | tsn = event->tsn; |
| 769 | |
| 770 | sctp_ulpevent_free(event); |
| 771 | sctp_tsnmap_renege(tsnmap, tsn); |
| 772 | if (freed >= needed) |
| 773 | return freed; |
| 774 | } |
| 775 | |
| 776 | return freed; |
| 777 | } |
| 778 | |
| 779 | /* Partial deliver the first message as there is pressure on rwnd. */ |
| 780 | void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq, |
Alexey Dobriyan | 3182cd84 | 2005-07-11 20:57:47 -0700 | [diff] [blame^] | 781 | struct sctp_chunk *chunk, |
| 782 | unsigned int __nocast gfp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 783 | { |
| 784 | struct sctp_ulpevent *event; |
| 785 | struct sctp_association *asoc; |
| 786 | |
| 787 | asoc = ulpq->asoc; |
| 788 | |
| 789 | /* Are we already in partial delivery mode? */ |
| 790 | if (!sctp_sk(asoc->base.sk)->pd_mode) { |
| 791 | |
| 792 | /* Is partial delivery possible? */ |
| 793 | event = sctp_ulpq_retrieve_first(ulpq); |
| 794 | /* Send event to the ULP. */ |
| 795 | if (event) { |
| 796 | sctp_ulpq_tail_event(ulpq, event); |
| 797 | sctp_sk(asoc->base.sk)->pd_mode = 1; |
| 798 | ulpq->pd_mode = 1; |
| 799 | return; |
| 800 | } |
| 801 | } |
| 802 | } |
| 803 | |
| 804 | /* Renege some packets to make room for an incoming chunk. */ |
| 805 | void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, |
Alexey Dobriyan | 3182cd84 | 2005-07-11 20:57:47 -0700 | [diff] [blame^] | 806 | unsigned int __nocast gfp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 807 | { |
| 808 | struct sctp_association *asoc; |
| 809 | __u16 needed, freed; |
| 810 | |
| 811 | asoc = ulpq->asoc; |
| 812 | |
| 813 | if (chunk) { |
| 814 | needed = ntohs(chunk->chunk_hdr->length); |
| 815 | needed -= sizeof(sctp_data_chunk_t); |
| 816 | } else |
| 817 | needed = SCTP_DEFAULT_MAXWINDOW; |
| 818 | |
| 819 | freed = 0; |
| 820 | |
| 821 | if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) { |
| 822 | freed = sctp_ulpq_renege_order(ulpq, needed); |
| 823 | if (freed < needed) { |
| 824 | freed += sctp_ulpq_renege_frags(ulpq, needed - freed); |
| 825 | } |
| 826 | } |
| 827 | /* If able to free enough room, accept this chunk. */ |
| 828 | if (chunk && (freed >= needed)) { |
| 829 | __u32 tsn; |
| 830 | tsn = ntohl(chunk->subh.data_hdr->tsn); |
| 831 | sctp_tsnmap_mark(&asoc->peer.tsn_map, tsn); |
| 832 | sctp_ulpq_tail_data(ulpq, chunk, gfp); |
| 833 | |
| 834 | sctp_ulpq_partial_delivery(ulpq, chunk, gfp); |
| 835 | } |
| 836 | |
| 837 | return; |
| 838 | } |
| 839 | |
| 840 | |
| 841 | |
| 842 | /* Notify the application if an association is aborted and in |
| 843 | * partial delivery mode. Send up any pending received messages. |
| 844 | */ |
Alexey Dobriyan | 3182cd84 | 2005-07-11 20:57:47 -0700 | [diff] [blame^] | 845 | void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, unsigned int __nocast gfp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 846 | { |
| 847 | struct sctp_ulpevent *ev = NULL; |
| 848 | struct sock *sk; |
| 849 | |
| 850 | if (!ulpq->pd_mode) |
| 851 | return; |
| 852 | |
| 853 | sk = ulpq->asoc->base.sk; |
| 854 | if (sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT, |
| 855 | &sctp_sk(sk)->subscribe)) |
| 856 | ev = sctp_ulpevent_make_pdapi(ulpq->asoc, |
| 857 | SCTP_PARTIAL_DELIVERY_ABORTED, |
| 858 | gfp); |
| 859 | if (ev) |
| 860 | __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev)); |
| 861 | |
| 862 | /* If there is data waiting, send it up the socket now. */ |
| 863 | if (sctp_ulpq_clear_pd(ulpq) || ev) |
| 864 | sk->sk_data_ready(sk, 0); |
| 865 | } |