diff options
Diffstat (limited to 'net/sctp/ulpqueue.c')
| -rw-r--r-- | net/sctp/ulpqueue.c | 864 |
1 files changed, 864 insertions, 0 deletions
diff --git a/net/sctp/ulpqueue.c b/net/sctp/ulpqueue.c new file mode 100644 index 00000000000..d5dd2cf7ac4 --- /dev/null +++ b/net/sctp/ulpqueue.c @@ -0,0 +1,864 @@ +/* SCTP kernel reference Implementation + * (C) Copyright IBM Corp. 2001, 2004 + * Copyright (c) 1999-2000 Cisco, Inc. + * Copyright (c) 1999-2001 Motorola, Inc. + * Copyright (c) 2001 Intel Corp. + * Copyright (c) 2001 Nokia, Inc. + * Copyright (c) 2001 La Monte H.P. Yarroll + * + * This abstraction carries sctp events to the ULP (sockets). + * + * The SCTP reference implementation is free software; + * you can redistribute it and/or modify it under the terms of + * the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * The SCTP reference implementation is distributed in the hope that it + * will be useful, but WITHOUT ANY WARRANTY; without even the implied + * ************************ + * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + * See the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GNU CC; see the file COPYING. If not, write to + * the Free Software Foundation, 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + * + * Please send any bug reports or fixes you make to the + * email address(es): + * lksctp developers <lksctp-developers@lists.sourceforge.net> + * + * Or submit a bug report through the following website: + * http://www.sf.net/projects/lksctp + * + * Written or modified by: + * Jon Grimm <jgrimm@us.ibm.com> + * La Monte H.P. Yarroll <piggy@acm.org> + * Sridhar Samudrala <sri@us.ibm.com> + * + * Any bugs reported given to us we will try to fix... any fixes shared will + * be incorporated into the next SCTP release. + */ + +#include <linux/types.h> +#include <linux/skbuff.h> +#include <net/sock.h> +#include <net/sctp/structs.h> +#include <net/sctp/sctp.h> +#include <net/sctp/sm.h> + +/* Forward declarations for internal helpers. */ +static struct sctp_ulpevent * sctp_ulpq_reasm(struct sctp_ulpq *ulpq, + struct sctp_ulpevent *); +static struct sctp_ulpevent * sctp_ulpq_order(struct sctp_ulpq *, + struct sctp_ulpevent *); + +/* 1st Level Abstractions */ + +/* Initialize a ULP queue from a block of memory. */ +struct sctp_ulpq *sctp_ulpq_init(struct sctp_ulpq *ulpq, + struct sctp_association *asoc) +{ + memset(ulpq, 0, sizeof(struct sctp_ulpq)); + + ulpq->asoc = asoc; + skb_queue_head_init(&ulpq->reasm); + skb_queue_head_init(&ulpq->lobby); + ulpq->pd_mode = 0; + ulpq->malloced = 0; + + return ulpq; +} + + +/* Flush the reassembly and ordering queues. */ +static void sctp_ulpq_flush(struct sctp_ulpq *ulpq) +{ + struct sk_buff *skb; + struct sctp_ulpevent *event; + + while ((skb = __skb_dequeue(&ulpq->lobby)) != NULL) { + event = sctp_skb2event(skb); + sctp_ulpevent_free(event); + } + + while ((skb = __skb_dequeue(&ulpq->reasm)) != NULL) { + event = sctp_skb2event(skb); + sctp_ulpevent_free(event); + } + +} + +/* Dispose of a ulpqueue. */ +void sctp_ulpq_free(struct sctp_ulpq *ulpq) +{ + sctp_ulpq_flush(ulpq); + if (ulpq->malloced) + kfree(ulpq); +} + +/* Process an incoming DATA chunk. */ +int sctp_ulpq_tail_data(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, + int gfp) +{ + struct sk_buff_head temp; + sctp_data_chunk_t *hdr; + struct sctp_ulpevent *event; + + hdr = (sctp_data_chunk_t *) chunk->chunk_hdr; + + /* Create an event from the incoming chunk. */ + event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp); + if (!event) + return -ENOMEM; + + /* Do reassembly if needed. */ + event = sctp_ulpq_reasm(ulpq, event); + + /* Do ordering if needed. */ + if ((event) && (event->msg_flags & MSG_EOR)){ + /* Create a temporary list to collect chunks on. */ + skb_queue_head_init(&temp); + __skb_queue_tail(&temp, sctp_event2skb(event)); + + event = sctp_ulpq_order(ulpq, event); + } + + /* Send event to the ULP. */ + if (event) + sctp_ulpq_tail_event(ulpq, event); + + return 0; +} + +/* Add a new event for propagation to the ULP. */ +/* Clear the partial delivery mode for this socket. Note: This + * assumes that no association is currently in partial delivery mode. + */ +int sctp_clear_pd(struct sock *sk) +{ + struct sctp_sock *sp = sctp_sk(sk); + + sp->pd_mode = 0; + if (!skb_queue_empty(&sp->pd_lobby)) { + struct list_head *list; + sctp_skb_list_tail(&sp->pd_lobby, &sk->sk_receive_queue); + list = (struct list_head *)&sctp_sk(sk)->pd_lobby; + INIT_LIST_HEAD(list); + return 1; + } + return 0; +} + +/* Clear the pd_mode and restart any pending messages waiting for delivery. */ +static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq) +{ + ulpq->pd_mode = 0; + return sctp_clear_pd(ulpq->asoc->base.sk); +} + + + +int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event) +{ + struct sock *sk = ulpq->asoc->base.sk; + struct sk_buff_head *queue; + int clear_pd = 0; + + /* If the socket is just going to throw this away, do not + * even try to deliver it. + */ + if (sock_flag(sk, SOCK_DEAD) || (sk->sk_shutdown & RCV_SHUTDOWN)) + goto out_free; + + /* Check if the user wishes to receive this event. */ + if (!sctp_ulpevent_is_enabled(event, &sctp_sk(sk)->subscribe)) + goto out_free; + + /* If we are in partial delivery mode, post to the lobby until + * partial delivery is cleared, unless, of course _this_ is + * the association the cause of the partial delivery. + */ + + if (!sctp_sk(sk)->pd_mode) { + queue = &sk->sk_receive_queue; + } else if (ulpq->pd_mode) { + if (event->msg_flags & MSG_NOTIFICATION) + queue = &sctp_sk(sk)->pd_lobby; + else { + clear_pd = event->msg_flags & MSG_EOR; + queue = &sk->sk_receive_queue; + } + } else + queue = &sctp_sk(sk)->pd_lobby; + + + /* If we are harvesting multiple skbs they will be + * collected on a list. + */ + if (sctp_event2skb(event)->list) + sctp_skb_list_tail(sctp_event2skb(event)->list, queue); + else + __skb_queue_tail(queue, sctp_event2skb(event)); + + /* Did we just complete partial delivery and need to get + * rolling again? Move pending data to the receive + * queue. + */ + if (clear_pd) + sctp_ulpq_clear_pd(ulpq); + + if (queue == &sk->sk_receive_queue) + sk->sk_data_ready(sk, 0); + return 1; + +out_free: + if (sctp_event2skb(event)->list) + sctp_queue_purge_ulpevents(sctp_event2skb(event)->list); + else + sctp_ulpevent_free(event); + return 0; +} + +/* 2nd Level Abstractions */ + +/* Helper function to store chunks that need to be reassembled. */ +static inline void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq, + struct sctp_ulpevent *event) +{ + struct sk_buff *pos; + struct sctp_ulpevent *cevent; + __u32 tsn, ctsn; + + tsn = event->tsn; + + /* See if it belongs at the end. */ + pos = skb_peek_tail(&ulpq->reasm); + if (!pos) { + __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); + return; + } + + /* Short circuit just dropping it at the end. */ + cevent = sctp_skb2event(pos); + ctsn = cevent->tsn; + if (TSN_lt(ctsn, tsn)) { + __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); + return; + } + + /* Find the right place in this list. We store them by TSN. */ + skb_queue_walk(&ulpq->reasm, pos) { + cevent = sctp_skb2event(pos); + ctsn = cevent->tsn; + + if (TSN_lt(tsn, ctsn)) + break; + } + + /* Insert before pos. */ + __skb_insert(sctp_event2skb(event), pos->prev, pos, &ulpq->reasm); + +} + +/* Helper function to return an event corresponding to the reassembled + * datagram. + * This routine creates a re-assembled skb given the first and last skb's + * as stored in the reassembly queue. The skb's may be non-linear if the sctp + * payload was fragmented on the way and ip had to reassemble them. + * We add the rest of skb's to the first skb's fraglist. + */ +static struct sctp_ulpevent *sctp_make_reassembled_event(struct sk_buff *f_frag, struct sk_buff *l_frag) +{ + struct sk_buff *pos; + struct sctp_ulpevent *event; + struct sk_buff *pnext, *last; + struct sk_buff *list = skb_shinfo(f_frag)->frag_list; + + /* Store the pointer to the 2nd skb */ + if (f_frag == l_frag) + pos = NULL; + else + pos = f_frag->next; + + /* Get the last skb in the f_frag's frag_list if present. */ + for (last = list; list; last = list, list = list->next); + + /* Add the list of remaining fragments to the first fragments + * frag_list. + */ + if (last) + last->next = pos; + else + skb_shinfo(f_frag)->frag_list = pos; + + /* Remove the first fragment from the reassembly queue. */ + __skb_unlink(f_frag, f_frag->list); + while (pos) { + + pnext = pos->next; + + /* Update the len and data_len fields of the first fragment. */ + f_frag->len += pos->len; + f_frag->data_len += pos->len; + + /* Remove the fragment from the reassembly queue. */ + __skb_unlink(pos, pos->list); + + /* Break if we have reached the last fragment. */ + if (pos == l_frag) + break; + pos->next = pnext; + pos = pnext; + }; + + event = sctp_skb2event(f_frag); + SCTP_INC_STATS(SCTP_MIB_REASMUSRMSGS); + + return event; +} + + +/* Helper function to check if an incoming chunk has filled up the last + * missing fragment in a SCTP datagram and return the corresponding event. + */ +static inline struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq) +{ + struct sk_buff *pos; + struct sctp_ulpevent *cevent; + struct sk_buff *first_frag = NULL; + __u32 ctsn, next_tsn; + struct sctp_ulpevent *retval = NULL; + + /* Initialized to 0 just to avoid compiler warning message. Will + * never be used with this value. It is referenced only after it + * is set when we find the first fragment of a message. + */ + next_tsn = 0; + + /* The chunks are held in the reasm queue sorted by TSN. + * Walk through the queue sequentially and look for a sequence of + * fragmented chunks that complete a datagram. + * 'first_frag' and next_tsn are reset when we find a chunk which + * is the first fragment of a datagram. Once these 2 fields are set + * we expect to find the remaining middle fragments and the last + * fragment in order. If not, first_frag is reset to NULL and we + * start the next pass when we find another first fragment. + */ + skb_queue_walk(&ulpq->reasm, pos) { + cevent = sctp_skb2event(pos); + ctsn = cevent->tsn; + + switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { + case SCTP_DATA_FIRST_FRAG: + first_frag = pos; + next_tsn = ctsn + 1; + break; + + case SCTP_DATA_MIDDLE_FRAG: + if ((first_frag) && (ctsn == next_tsn)) + next_tsn++; + else + first_frag = NULL; + break; + + case SCTP_DATA_LAST_FRAG: + if (first_frag && (ctsn == next_tsn)) + goto found; + else + first_frag = NULL; + break; + }; + + } +done: + return retval; +found: + retval = sctp_make_reassembled_event(first_frag, pos); + if (retval) + retval->msg_flags |= MSG_EOR; + goto done; +} + +/* Retrieve the next set of fragments of a partial message. */ +static inline struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq) +{ + struct sk_buff *pos, *last_frag, *first_frag; + struct sctp_ulpevent *cevent; + __u32 ctsn, next_tsn; + int is_last; + struct sctp_ulpevent *retval; + + /* The chunks are held in the reasm queue sorted by TSN. + * Walk through the queue sequentially and look for the first + * sequence of fragmented chunks. + */ + + if (skb_queue_empty(&ulpq->reasm)) + return NULL; + + last_frag = first_frag = NULL; + retval = NULL; + next_tsn = 0; + is_last = 0; + + skb_queue_walk(&ulpq->reasm, pos) { + cevent = sctp_skb2event(pos); + ctsn = cevent->tsn; + + switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { + case SCTP_DATA_MIDDLE_FRAG: + if (!first_frag) { + first_frag = pos; + next_tsn = ctsn + 1; + last_frag = pos; + } else if (next_tsn == ctsn) + next_tsn++; + else + goto done; + break; + case SCTP_DATA_LAST_FRAG: + if (!first_frag) + first_frag = pos; + else if (ctsn != next_tsn) + goto done; + last_frag = pos; + is_last = 1; + goto done; + default: + return NULL; + }; + } + + /* We have the reassembled event. There is no need to look + * further. + */ +done: + retval = sctp_make_reassembled_event(first_frag, last_frag); + if (retval && is_last) + retval->msg_flags |= MSG_EOR; + + return retval; +} + + +/* Helper function to reassemble chunks. Hold chunks on the reasm queue that + * need reassembling. + */ +static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq, + struct sctp_ulpevent *event) +{ + struct sctp_ulpevent *retval = NULL; + + /* Check if this is part of a fragmented message. */ + if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) { + event->msg_flags |= MSG_EOR; + return event; + } + + sctp_ulpq_store_reasm(ulpq, event); + if (!ulpq->pd_mode) + retval = sctp_ulpq_retrieve_reassembled(ulpq); + else { + __u32 ctsn, ctsnap; + + /* Do not even bother unless this is the next tsn to + * be delivered. + */ + ctsn = event->tsn; + ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map); + if (TSN_lte(ctsn, ctsnap)) + retval = sctp_ulpq_retrieve_partial(ulpq); + } + + return retval; +} + +/* Retrieve the first part (sequential fragments) for partial delivery. */ +static inline struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq) +{ + struct sk_buff *pos, *last_frag, *first_frag; + struct sctp_ulpevent *cevent; + __u32 ctsn, next_tsn; + struct sctp_ulpevent *retval; + + /* The chunks are held in the reasm queue sorted by TSN. + * Walk through the queue sequentially and look for a sequence of + * fragmented chunks that start a datagram. + */ + + if (skb_queue_empty(&ulpq->reasm)) + return NULL; + + last_frag = first_frag = NULL; + retval = NULL; + next_tsn = 0; + + skb_queue_walk(&ulpq->reasm, pos) { + cevent = sctp_skb2event(pos); + ctsn = cevent->tsn; + + switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { + case SCTP_DATA_FIRST_FRAG: + if (!first_frag) { + first_frag = pos; + next_tsn = ctsn + 1; + last_frag = pos; + } else + goto done; + break; + + case SCTP_DATA_MIDDLE_FRAG: + if (!first_frag) + return NULL; + if (ctsn == next_tsn) { + next_tsn++; + last_frag = pos; + } else + goto done; + break; + default: + return NULL; + }; + } + + /* We have the reassembled event. There is no need to look + * further. + */ +done: + retval = sctp_make_reassembled_event(first_frag, last_frag); + return retval; +} + +/* Helper function to gather skbs that have possibly become + * ordered by an an incoming chunk. + */ +static inline void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq, + struct sctp_ulpevent *event) +{ + struct sk_buff *pos, *tmp; + struct sctp_ulpevent *cevent; + struct sctp_stream *in; + __u16 sid, csid; + __u16 ssn, cssn; + + sid = event->stream; + ssn = event->ssn; + in = &ulpq->asoc->ssnmap->in; + + /* We are holding the chunks by stream, by SSN. */ + sctp_skb_for_each(pos, &ulpq->lobby, tmp) { + cevent = (struct sctp_ulpevent *) pos->cb; + csid = cevent->stream; + cssn = cevent->ssn; + + /* Have we gone too far? */ + if (csid > sid) + break; + + /* Have we not gone far enough? */ + if (csid < sid) + continue; + + if (cssn != sctp_ssn_peek(in, sid)) + break; + + /* Found it, so mark in the ssnmap. */ + sctp_ssn_next(in, sid); + + __skb_unlink(pos, pos->list); + + /* Attach all gathered skbs to the event. */ + __skb_queue_tail(sctp_event2skb(event)->list, pos); + } +} + +/* Helper function to store chunks needing ordering. */ +static inline void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq, + struct sctp_ulpevent *event) +{ + struct sk_buff *pos; + struct sctp_ulpevent *cevent; + __u16 sid, csid; + __u16 ssn, cssn; + + pos = skb_peek_tail(&ulpq->lobby); + if (!pos) { + __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); + return; + } + + sid = event->stream; + ssn = event->ssn; + + cevent = (struct sctp_ulpevent *) pos->cb; + csid = cevent->stream; + cssn = cevent->ssn; + if (sid > csid) { + __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); + return; + } + + if ((sid == csid) && SSN_lt(cssn, ssn)) { + __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); + return; + } + + /* Find the right place in this list. We store them by + * stream ID and then by SSN. + */ + skb_queue_walk(&ulpq->lobby, pos) { + cevent = (struct sctp_ulpevent *) pos->cb; + csid = cevent->stream; + cssn = cevent->ssn; + + if (csid > sid) + break; + if (csid == sid && SSN_lt(ssn, cssn)) + break; + } + + + /* Insert before pos. */ + __skb_insert(sctp_event2skb(event), pos->prev, pos, &ulpq->lobby); + +} + +static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq, + struct sctp_ulpevent *event) +{ + __u16 sid, ssn; + struct sctp_stream *in; + + /* Check if this message needs ordering. */ + if (SCTP_DATA_UNORDERED & event->msg_flags) + return event; + + /* Note: The stream ID must be verified before this routine. */ + sid = event->stream; + ssn = event->ssn; + in = &ulpq->asoc->ssnmap->in; + + /* Is this the expected SSN for this stream ID? */ + if (ssn != sctp_ssn_peek(in, sid)) { + /* We've received something out of order, so find where it + * needs to be placed. We order by stream and then by SSN. + */ + sctp_ulpq_store_ordered(ulpq, event); + return NULL; + } + + /* Mark that the next chunk has been found. */ + sctp_ssn_next(in, sid); + + /* Go find any other chunks that were waiting for + * ordering. + */ + sctp_ulpq_retrieve_ordered(ulpq, event); + + return event; +} + +/* Helper function to gather skbs that have possibly become + * ordered by forward tsn skipping their dependencies. + */ +static inline void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq) +{ + struct sk_buff *pos, *tmp; + struct sctp_ulpevent *cevent; + struct sctp_ulpevent *event = NULL; + struct sctp_stream *in; + struct sk_buff_head temp; + __u16 csid, cssn; + + in = &ulpq->asoc->ssnmap->in; + + /* We are holding the chunks by stream, by SSN. */ + sctp_skb_for_each(pos, &ulpq->lobby, tmp) { + cevent = (struct sctp_ulpevent *) pos->cb; + csid = cevent->stream; + cssn = cevent->ssn; + + if (cssn != sctp_ssn_peek(in, csid)) + break; + + /* Found it, so mark in the ssnmap. */ + sctp_ssn_next(in, csid); + + __skb_unlink(pos, pos->list); + if (!event) { + /* Create a temporary list to collect chunks on. */ + event = sctp_skb2event(pos); + skb_queue_head_init(&temp); + __skb_queue_tail(&temp, sctp_event2skb(event)); + } else { + /* Attach all gathered skbs to the event. */ + __skb_queue_tail(sctp_event2skb(event)->list, pos); + } + } + + /* Send event to the ULP. */ + if (event) + sctp_ulpq_tail_event(ulpq, event); +} + +/* Skip over an SSN. */ +void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn) +{ + struct sctp_stream *in; + + /* Note: The stream ID must be verified before this routine. */ + in = &ulpq->asoc->ssnmap->in; + + /* Is this an old SSN? If so ignore. */ + if (SSN_lt(ssn, sctp_ssn_peek(in, sid))) + return; + + /* Mark that we are no longer expecting this SSN or lower. */ + sctp_ssn_skip(in, sid, ssn); + + /* Go find any other chunks that were waiting for + * ordering and deliver them if needed. + */ + sctp_ulpq_reap_ordered(ulpq); + return; +} + +/* Renege 'needed' bytes from the ordering queue. */ +static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed) +{ + __u16 freed = 0; + __u32 tsn; + struct sk_buff *skb; + struct sctp_ulpevent *event; + struct sctp_tsnmap *tsnmap; + + tsnmap = &ulpq->asoc->peer.tsn_map; + + while ((skb = __skb_dequeue_tail(&ulpq->lobby)) != NULL) { + freed += skb_headlen(skb); + event = sctp_skb2event(skb); + tsn = event->tsn; + + sctp_ulpevent_free(event); + sctp_tsnmap_renege(tsnmap, tsn); + if (freed >= needed) + return freed; + } + + return freed; +} + +/* Renege 'needed' bytes from the reassembly queue. */ +static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed) +{ + __u16 freed = 0; + __u32 tsn; + struct sk_buff *skb; + struct sctp_ulpevent *event; + struct sctp_tsnmap *tsnmap; + + tsnmap = &ulpq->asoc->peer.tsn_map; + + /* Walk backwards through the list, reneges the newest tsns. */ + while ((skb = __skb_dequeue_tail(&ulpq->reasm)) != NULL) { + freed += skb_headlen(skb); + event = sctp_skb2event(skb); + tsn = event->tsn; + + sctp_ulpevent_free(event); + sctp_tsnmap_renege(tsnmap, tsn); + if (freed >= needed) + return freed; + } + + return freed; +} + +/* Partial deliver the first message as there is pressure on rwnd. */ +void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq, + struct sctp_chunk *chunk, int gfp) +{ + struct sctp_ulpevent *event; + struct sctp_association *asoc; + + asoc = ulpq->asoc; + + /* Are we already in partial delivery mode? */ + if (!sctp_sk(asoc->base.sk)->pd_mode) { + + /* Is partial delivery possible? */ + event = sctp_ulpq_retrieve_first(ulpq); + /* Send event to the ULP. */ + if (event) { + sctp_ulpq_tail_event(ulpq, event); + sctp_sk(asoc->base.sk)->pd_mode = 1; + ulpq->pd_mode = 1; + return; + } + } +} + +/* Renege some packets to make room for an incoming chunk. */ +void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, + int gfp) +{ + struct sctp_association *asoc; + __u16 needed, freed; + + asoc = ulpq->asoc; + + if (chunk) { + needed = ntohs(chunk->chunk_hdr->length); + needed -= sizeof(sctp_data_chunk_t); + } else + needed = SCTP_DEFAULT_MAXWINDOW; + + freed = 0; + + if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) { + freed = sctp_ulpq_renege_order(ulpq, needed); + if (freed < needed) { + freed += sctp_ulpq_renege_frags(ulpq, needed - freed); + } + } + /* If able to free enough room, accept this chunk. */ + if (chunk && (freed >= needed)) { + __u32 tsn; + tsn = ntohl(chunk->subh.data_hdr->tsn); + sctp_tsnmap_mark(&asoc->peer.tsn_map, tsn); + sctp_ulpq_tail_data(ulpq, chunk, gfp); + + sctp_ulpq_partial_delivery(ulpq, chunk, gfp); + } + + return; +} + + + +/* Notify the application if an association is aborted and in + * partial delivery mode. Send up any pending received messages. + */ +void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, int gfp) +{ + struct sctp_ulpevent *ev = NULL; + struct sock *sk; + + if (!ulpq->pd_mode) + return; + + sk = ulpq->asoc->base.sk; + if (sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT, + &sctp_sk(sk)->subscribe)) + ev = sctp_ulpevent_make_pdapi(ulpq->asoc, + SCTP_PARTIAL_DELIVERY_ABORTED, + gfp); + if (ev) + __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev)); + + /* If there is data waiting, send it up the socket now. */ + if (sctp_ulpq_clear_pd(ulpq) || ev) + sk->sk_data_ready(sk, 0); +} |