95c9617472
Use of "unsigned int" is preferred to bare "unsigned" in net tree. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1918 lines
55 KiB
C
1918 lines
55 KiB
C
/* SCTP kernel implementation
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* (C) Copyright IBM Corp. 2001, 2004
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* Copyright (c) 1999-2000 Cisco, Inc.
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* Copyright (c) 1999-2001 Motorola, Inc.
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* Copyright (c) 2001-2003 Intel Corp.
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*
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* This file is part of the SCTP kernel implementation
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*
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* These functions implement the sctp_outq class. The outqueue handles
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* bundling and queueing of outgoing SCTP chunks.
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*
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* This SCTP implementation is free software;
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* you can redistribute it and/or modify it under the terms of
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* the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* This SCTP implementation is distributed in the hope that it
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* will be useful, but WITHOUT ANY WARRANTY; without even the implied
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* ************************
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* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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* See the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GNU CC; see the file COPYING. If not, write to
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* the Free Software Foundation, 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*
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* Please send any bug reports or fixes you make to the
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* email address(es):
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* lksctp developers <lksctp-developers@lists.sourceforge.net>
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*
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* Or submit a bug report through the following website:
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* http://www.sf.net/projects/lksctp
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*
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* Written or modified by:
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* La Monte H.P. Yarroll <piggy@acm.org>
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* Karl Knutson <karl@athena.chicago.il.us>
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* Perry Melange <pmelange@null.cc.uic.edu>
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* Xingang Guo <xingang.guo@intel.com>
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* Hui Huang <hui.huang@nokia.com>
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* Sridhar Samudrala <sri@us.ibm.com>
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* Jon Grimm <jgrimm@us.ibm.com>
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*
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* Any bugs reported given to us we will try to fix... any fixes shared will
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* be incorporated into the next SCTP release.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/types.h>
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#include <linux/list.h> /* For struct list_head */
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#include <linux/socket.h>
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#include <linux/ip.h>
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#include <linux/slab.h>
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#include <net/sock.h> /* For skb_set_owner_w */
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#include <net/sctp/sctp.h>
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#include <net/sctp/sm.h>
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/* Declare internal functions here. */
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static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn);
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static void sctp_check_transmitted(struct sctp_outq *q,
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struct list_head *transmitted_queue,
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struct sctp_transport *transport,
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struct sctp_sackhdr *sack,
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__u32 *highest_new_tsn);
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static void sctp_mark_missing(struct sctp_outq *q,
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struct list_head *transmitted_queue,
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struct sctp_transport *transport,
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__u32 highest_new_tsn,
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int count_of_newacks);
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static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
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static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout);
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/* Add data to the front of the queue. */
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static inline void sctp_outq_head_data(struct sctp_outq *q,
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struct sctp_chunk *ch)
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{
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list_add(&ch->list, &q->out_chunk_list);
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q->out_qlen += ch->skb->len;
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}
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/* Take data from the front of the queue. */
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static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q)
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{
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struct sctp_chunk *ch = NULL;
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if (!list_empty(&q->out_chunk_list)) {
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struct list_head *entry = q->out_chunk_list.next;
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ch = list_entry(entry, struct sctp_chunk, list);
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list_del_init(entry);
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q->out_qlen -= ch->skb->len;
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}
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return ch;
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}
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/* Add data chunk to the end of the queue. */
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static inline void sctp_outq_tail_data(struct sctp_outq *q,
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struct sctp_chunk *ch)
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{
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list_add_tail(&ch->list, &q->out_chunk_list);
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q->out_qlen += ch->skb->len;
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}
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/*
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* SFR-CACC algorithm:
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* D) If count_of_newacks is greater than or equal to 2
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* and t was not sent to the current primary then the
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* sender MUST NOT increment missing report count for t.
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*/
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static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary,
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struct sctp_transport *transport,
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int count_of_newacks)
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{
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if (count_of_newacks >=2 && transport != primary)
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return 1;
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return 0;
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}
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/*
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* SFR-CACC algorithm:
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* F) If count_of_newacks is less than 2, let d be the
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* destination to which t was sent. If cacc_saw_newack
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* is 0 for destination d, then the sender MUST NOT
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* increment missing report count for t.
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*/
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static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport,
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int count_of_newacks)
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{
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if (count_of_newacks < 2 &&
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(transport && !transport->cacc.cacc_saw_newack))
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return 1;
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return 0;
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}
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/*
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* SFR-CACC algorithm:
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* 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD
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* execute steps C, D, F.
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*
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* C has been implemented in sctp_outq_sack
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*/
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static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary,
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struct sctp_transport *transport,
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int count_of_newacks)
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{
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if (!primary->cacc.cycling_changeover) {
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if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks))
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return 1;
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if (sctp_cacc_skip_3_1_f(transport, count_of_newacks))
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return 1;
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return 0;
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}
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return 0;
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}
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/*
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* SFR-CACC algorithm:
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* 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less
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* than next_tsn_at_change of the current primary, then
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* the sender MUST NOT increment missing report count
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* for t.
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*/
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static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn)
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{
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if (primary->cacc.cycling_changeover &&
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TSN_lt(tsn, primary->cacc.next_tsn_at_change))
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return 1;
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return 0;
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}
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/*
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* SFR-CACC algorithm:
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* 3) If the missing report count for TSN t is to be
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* incremented according to [RFC2960] and
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* [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set,
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* then the sender MUST further execute steps 3.1 and
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* 3.2 to determine if the missing report count for
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* TSN t SHOULD NOT be incremented.
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*
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* 3.3) If 3.1 and 3.2 do not dictate that the missing
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* report count for t should not be incremented, then
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* the sender SHOULD increment missing report count for
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* t (according to [RFC2960] and [SCTP_STEWART_2002]).
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*/
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static inline int sctp_cacc_skip(struct sctp_transport *primary,
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struct sctp_transport *transport,
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int count_of_newacks,
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__u32 tsn)
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{
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if (primary->cacc.changeover_active &&
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(sctp_cacc_skip_3_1(primary, transport, count_of_newacks) ||
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sctp_cacc_skip_3_2(primary, tsn)))
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return 1;
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return 0;
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}
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/* Initialize an existing sctp_outq. This does the boring stuff.
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* You still need to define handlers if you really want to DO
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* something with this structure...
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*/
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void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q)
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{
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q->asoc = asoc;
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INIT_LIST_HEAD(&q->out_chunk_list);
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INIT_LIST_HEAD(&q->control_chunk_list);
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INIT_LIST_HEAD(&q->retransmit);
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INIT_LIST_HEAD(&q->sacked);
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INIT_LIST_HEAD(&q->abandoned);
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q->fast_rtx = 0;
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q->outstanding_bytes = 0;
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q->empty = 1;
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q->cork = 0;
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q->malloced = 0;
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q->out_qlen = 0;
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}
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/* Free the outqueue structure and any related pending chunks.
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*/
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void sctp_outq_teardown(struct sctp_outq *q)
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{
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struct sctp_transport *transport;
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struct list_head *lchunk, *temp;
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struct sctp_chunk *chunk, *tmp;
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/* Throw away unacknowledged chunks. */
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list_for_each_entry(transport, &q->asoc->peer.transport_addr_list,
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transports) {
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while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) {
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chunk = list_entry(lchunk, struct sctp_chunk,
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transmitted_list);
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/* Mark as part of a failed message. */
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sctp_chunk_fail(chunk, q->error);
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sctp_chunk_free(chunk);
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}
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}
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/* Throw away chunks that have been gap ACKed. */
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list_for_each_safe(lchunk, temp, &q->sacked) {
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list_del_init(lchunk);
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chunk = list_entry(lchunk, struct sctp_chunk,
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transmitted_list);
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sctp_chunk_fail(chunk, q->error);
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sctp_chunk_free(chunk);
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}
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/* Throw away any chunks in the retransmit queue. */
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list_for_each_safe(lchunk, temp, &q->retransmit) {
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list_del_init(lchunk);
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chunk = list_entry(lchunk, struct sctp_chunk,
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transmitted_list);
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sctp_chunk_fail(chunk, q->error);
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sctp_chunk_free(chunk);
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}
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/* Throw away any chunks that are in the abandoned queue. */
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list_for_each_safe(lchunk, temp, &q->abandoned) {
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list_del_init(lchunk);
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chunk = list_entry(lchunk, struct sctp_chunk,
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transmitted_list);
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sctp_chunk_fail(chunk, q->error);
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sctp_chunk_free(chunk);
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}
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/* Throw away any leftover data chunks. */
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while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
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/* Mark as send failure. */
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sctp_chunk_fail(chunk, q->error);
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sctp_chunk_free(chunk);
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}
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q->error = 0;
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/* Throw away any leftover control chunks. */
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list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
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list_del_init(&chunk->list);
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sctp_chunk_free(chunk);
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}
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}
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/* Free the outqueue structure and any related pending chunks. */
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void sctp_outq_free(struct sctp_outq *q)
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{
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/* Throw away leftover chunks. */
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sctp_outq_teardown(q);
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/* If we were kmalloc()'d, free the memory. */
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if (q->malloced)
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kfree(q);
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}
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/* Put a new chunk in an sctp_outq. */
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int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk)
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{
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int error = 0;
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SCTP_DEBUG_PRINTK("sctp_outq_tail(%p, %p[%s])\n",
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q, chunk, chunk && chunk->chunk_hdr ?
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sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
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: "Illegal Chunk");
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/* If it is data, queue it up, otherwise, send it
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* immediately.
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*/
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if (sctp_chunk_is_data(chunk)) {
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/* Is it OK to queue data chunks? */
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/* From 9. Termination of Association
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*
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* When either endpoint performs a shutdown, the
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* association on each peer will stop accepting new
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* data from its user and only deliver data in queue
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* at the time of sending or receiving the SHUTDOWN
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* chunk.
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*/
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switch (q->asoc->state) {
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case SCTP_STATE_CLOSED:
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case SCTP_STATE_SHUTDOWN_PENDING:
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case SCTP_STATE_SHUTDOWN_SENT:
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case SCTP_STATE_SHUTDOWN_RECEIVED:
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case SCTP_STATE_SHUTDOWN_ACK_SENT:
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/* Cannot send after transport endpoint shutdown */
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error = -ESHUTDOWN;
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break;
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default:
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SCTP_DEBUG_PRINTK("outqueueing (%p, %p[%s])\n",
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q, chunk, chunk && chunk->chunk_hdr ?
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sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
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: "Illegal Chunk");
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sctp_outq_tail_data(q, chunk);
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if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
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SCTP_INC_STATS(SCTP_MIB_OUTUNORDERCHUNKS);
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else
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SCTP_INC_STATS(SCTP_MIB_OUTORDERCHUNKS);
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q->empty = 0;
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break;
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}
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} else {
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list_add_tail(&chunk->list, &q->control_chunk_list);
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SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
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}
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if (error < 0)
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return error;
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if (!q->cork)
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error = sctp_outq_flush(q, 0);
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return error;
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}
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/* Insert a chunk into the sorted list based on the TSNs. The retransmit list
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* and the abandoned list are in ascending order.
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*/
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static void sctp_insert_list(struct list_head *head, struct list_head *new)
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{
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struct list_head *pos;
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struct sctp_chunk *nchunk, *lchunk;
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__u32 ntsn, ltsn;
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int done = 0;
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nchunk = list_entry(new, struct sctp_chunk, transmitted_list);
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ntsn = ntohl(nchunk->subh.data_hdr->tsn);
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list_for_each(pos, head) {
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lchunk = list_entry(pos, struct sctp_chunk, transmitted_list);
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ltsn = ntohl(lchunk->subh.data_hdr->tsn);
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if (TSN_lt(ntsn, ltsn)) {
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list_add(new, pos->prev);
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done = 1;
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break;
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}
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}
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if (!done)
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list_add_tail(new, head);
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}
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/* Mark all the eligible packets on a transport for retransmission. */
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void sctp_retransmit_mark(struct sctp_outq *q,
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struct sctp_transport *transport,
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__u8 reason)
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{
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struct list_head *lchunk, *ltemp;
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struct sctp_chunk *chunk;
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/* Walk through the specified transmitted queue. */
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list_for_each_safe(lchunk, ltemp, &transport->transmitted) {
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chunk = list_entry(lchunk, struct sctp_chunk,
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transmitted_list);
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/* If the chunk is abandoned, move it to abandoned list. */
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if (sctp_chunk_abandoned(chunk)) {
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list_del_init(lchunk);
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sctp_insert_list(&q->abandoned, lchunk);
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/* If this chunk has not been previousely acked,
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* stop considering it 'outstanding'. Our peer
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* will most likely never see it since it will
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* not be retransmitted
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*/
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if (!chunk->tsn_gap_acked) {
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if (chunk->transport)
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chunk->transport->flight_size -=
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sctp_data_size(chunk);
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q->outstanding_bytes -= sctp_data_size(chunk);
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q->asoc->peer.rwnd += sctp_data_size(chunk);
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}
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continue;
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}
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/* If we are doing retransmission due to a timeout or pmtu
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* discovery, only the chunks that are not yet acked should
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* be added to the retransmit queue.
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*/
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if ((reason == SCTP_RTXR_FAST_RTX &&
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(chunk->fast_retransmit == SCTP_NEED_FRTX)) ||
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(reason != SCTP_RTXR_FAST_RTX && !chunk->tsn_gap_acked)) {
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/* RFC 2960 6.2.1 Processing a Received SACK
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*
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* C) Any time a DATA chunk is marked for
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* retransmission (via either T3-rtx timer expiration
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* (Section 6.3.3) or via fast retransmit
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* (Section 7.2.4)), add the data size of those
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* chunks to the rwnd.
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*/
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q->asoc->peer.rwnd += sctp_data_size(chunk);
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q->outstanding_bytes -= sctp_data_size(chunk);
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if (chunk->transport)
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transport->flight_size -= sctp_data_size(chunk);
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/* sctpimpguide-05 Section 2.8.2
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* M5) If a T3-rtx timer expires, the
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* 'TSN.Missing.Report' of all affected TSNs is set
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* to 0.
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*/
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chunk->tsn_missing_report = 0;
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/* If a chunk that is being used for RTT measurement
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* has to be retransmitted, we cannot use this chunk
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* anymore for RTT measurements. Reset rto_pending so
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* that a new RTT measurement is started when a new
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* data chunk is sent.
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*/
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if (chunk->rtt_in_progress) {
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chunk->rtt_in_progress = 0;
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transport->rto_pending = 0;
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}
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/* Move the chunk to the retransmit queue. The chunks
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* on the retransmit queue are always kept in order.
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*/
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list_del_init(lchunk);
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sctp_insert_list(&q->retransmit, lchunk);
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}
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}
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SCTP_DEBUG_PRINTK("%s: transport: %p, reason: %d, "
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"cwnd: %d, ssthresh: %d, flight_size: %d, "
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"pba: %d\n", __func__,
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transport, reason,
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transport->cwnd, transport->ssthresh,
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transport->flight_size,
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transport->partial_bytes_acked);
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}
|
|
|
|
/* Mark all the eligible packets on a transport for retransmission and force
|
|
* one packet out.
|
|
*/
|
|
void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
|
|
sctp_retransmit_reason_t reason)
|
|
{
|
|
int error = 0;
|
|
|
|
switch(reason) {
|
|
case SCTP_RTXR_T3_RTX:
|
|
SCTP_INC_STATS(SCTP_MIB_T3_RETRANSMITS);
|
|
sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX);
|
|
/* Update the retran path if the T3-rtx timer has expired for
|
|
* the current retran path.
|
|
*/
|
|
if (transport == transport->asoc->peer.retran_path)
|
|
sctp_assoc_update_retran_path(transport->asoc);
|
|
transport->asoc->rtx_data_chunks +=
|
|
transport->asoc->unack_data;
|
|
break;
|
|
case SCTP_RTXR_FAST_RTX:
|
|
SCTP_INC_STATS(SCTP_MIB_FAST_RETRANSMITS);
|
|
sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX);
|
|
q->fast_rtx = 1;
|
|
break;
|
|
case SCTP_RTXR_PMTUD:
|
|
SCTP_INC_STATS(SCTP_MIB_PMTUD_RETRANSMITS);
|
|
break;
|
|
case SCTP_RTXR_T1_RTX:
|
|
SCTP_INC_STATS(SCTP_MIB_T1_RETRANSMITS);
|
|
transport->asoc->init_retries++;
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
sctp_retransmit_mark(q, transport, reason);
|
|
|
|
/* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination,
|
|
* the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by
|
|
* following the procedures outlined in C1 - C5.
|
|
*/
|
|
if (reason == SCTP_RTXR_T3_RTX)
|
|
sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point);
|
|
|
|
/* Flush the queues only on timeout, since fast_rtx is only
|
|
* triggered during sack processing and the queue
|
|
* will be flushed at the end.
|
|
*/
|
|
if (reason != SCTP_RTXR_FAST_RTX)
|
|
error = sctp_outq_flush(q, /* rtx_timeout */ 1);
|
|
|
|
if (error)
|
|
q->asoc->base.sk->sk_err = -error;
|
|
}
|
|
|
|
/*
|
|
* Transmit DATA chunks on the retransmit queue. Upon return from
|
|
* sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which
|
|
* need to be transmitted by the caller.
|
|
* We assume that pkt->transport has already been set.
|
|
*
|
|
* The return value is a normal kernel error return value.
|
|
*/
|
|
static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
|
|
int rtx_timeout, int *start_timer)
|
|
{
|
|
struct list_head *lqueue;
|
|
struct sctp_transport *transport = pkt->transport;
|
|
sctp_xmit_t status;
|
|
struct sctp_chunk *chunk, *chunk1;
|
|
int fast_rtx;
|
|
int error = 0;
|
|
int timer = 0;
|
|
int done = 0;
|
|
|
|
lqueue = &q->retransmit;
|
|
fast_rtx = q->fast_rtx;
|
|
|
|
/* This loop handles time-out retransmissions, fast retransmissions,
|
|
* and retransmissions due to opening of whindow.
|
|
*
|
|
* RFC 2960 6.3.3 Handle T3-rtx Expiration
|
|
*
|
|
* E3) Determine how many of the earliest (i.e., lowest TSN)
|
|
* outstanding DATA chunks for the address for which the
|
|
* T3-rtx has expired will fit into a single packet, subject
|
|
* to the MTU constraint for the path corresponding to the
|
|
* destination transport address to which the retransmission
|
|
* is being sent (this may be different from the address for
|
|
* which the timer expires [see Section 6.4]). Call this value
|
|
* K. Bundle and retransmit those K DATA chunks in a single
|
|
* packet to the destination endpoint.
|
|
*
|
|
* [Just to be painfully clear, if we are retransmitting
|
|
* because a timeout just happened, we should send only ONE
|
|
* packet of retransmitted data.]
|
|
*
|
|
* For fast retransmissions we also send only ONE packet. However,
|
|
* if we are just flushing the queue due to open window, we'll
|
|
* try to send as much as possible.
|
|
*/
|
|
list_for_each_entry_safe(chunk, chunk1, lqueue, transmitted_list) {
|
|
/* If the chunk is abandoned, move it to abandoned list. */
|
|
if (sctp_chunk_abandoned(chunk)) {
|
|
list_del_init(&chunk->transmitted_list);
|
|
sctp_insert_list(&q->abandoned,
|
|
&chunk->transmitted_list);
|
|
continue;
|
|
}
|
|
|
|
/* Make sure that Gap Acked TSNs are not retransmitted. A
|
|
* simple approach is just to move such TSNs out of the
|
|
* way and into a 'transmitted' queue and skip to the
|
|
* next chunk.
|
|
*/
|
|
if (chunk->tsn_gap_acked) {
|
|
list_del(&chunk->transmitted_list);
|
|
list_add_tail(&chunk->transmitted_list,
|
|
&transport->transmitted);
|
|
continue;
|
|
}
|
|
|
|
/* If we are doing fast retransmit, ignore non-fast_rtransmit
|
|
* chunks
|
|
*/
|
|
if (fast_rtx && !chunk->fast_retransmit)
|
|
continue;
|
|
|
|
redo:
|
|
/* Attempt to append this chunk to the packet. */
|
|
status = sctp_packet_append_chunk(pkt, chunk);
|
|
|
|
switch (status) {
|
|
case SCTP_XMIT_PMTU_FULL:
|
|
if (!pkt->has_data && !pkt->has_cookie_echo) {
|
|
/* If this packet did not contain DATA then
|
|
* retransmission did not happen, so do it
|
|
* again. We'll ignore the error here since
|
|
* control chunks are already freed so there
|
|
* is nothing we can do.
|
|
*/
|
|
sctp_packet_transmit(pkt);
|
|
goto redo;
|
|
}
|
|
|
|
/* Send this packet. */
|
|
error = sctp_packet_transmit(pkt);
|
|
|
|
/* If we are retransmitting, we should only
|
|
* send a single packet.
|
|
* Otherwise, try appending this chunk again.
|
|
*/
|
|
if (rtx_timeout || fast_rtx)
|
|
done = 1;
|
|
else
|
|
goto redo;
|
|
|
|
/* Bundle next chunk in the next round. */
|
|
break;
|
|
|
|
case SCTP_XMIT_RWND_FULL:
|
|
/* Send this packet. */
|
|
error = sctp_packet_transmit(pkt);
|
|
|
|
/* Stop sending DATA as there is no more room
|
|
* at the receiver.
|
|
*/
|
|
done = 1;
|
|
break;
|
|
|
|
case SCTP_XMIT_NAGLE_DELAY:
|
|
/* Send this packet. */
|
|
error = sctp_packet_transmit(pkt);
|
|
|
|
/* Stop sending DATA because of nagle delay. */
|
|
done = 1;
|
|
break;
|
|
|
|
default:
|
|
/* The append was successful, so add this chunk to
|
|
* the transmitted list.
|
|
*/
|
|
list_del(&chunk->transmitted_list);
|
|
list_add_tail(&chunk->transmitted_list,
|
|
&transport->transmitted);
|
|
|
|
/* Mark the chunk as ineligible for fast retransmit
|
|
* after it is retransmitted.
|
|
*/
|
|
if (chunk->fast_retransmit == SCTP_NEED_FRTX)
|
|
chunk->fast_retransmit = SCTP_DONT_FRTX;
|
|
|
|
q->empty = 0;
|
|
break;
|
|
}
|
|
|
|
/* Set the timer if there were no errors */
|
|
if (!error && !timer)
|
|
timer = 1;
|
|
|
|
if (done)
|
|
break;
|
|
}
|
|
|
|
/* If we are here due to a retransmit timeout or a fast
|
|
* retransmit and if there are any chunks left in the retransmit
|
|
* queue that could not fit in the PMTU sized packet, they need
|
|
* to be marked as ineligible for a subsequent fast retransmit.
|
|
*/
|
|
if (rtx_timeout || fast_rtx) {
|
|
list_for_each_entry(chunk1, lqueue, transmitted_list) {
|
|
if (chunk1->fast_retransmit == SCTP_NEED_FRTX)
|
|
chunk1->fast_retransmit = SCTP_DONT_FRTX;
|
|
}
|
|
}
|
|
|
|
*start_timer = timer;
|
|
|
|
/* Clear fast retransmit hint */
|
|
if (fast_rtx)
|
|
q->fast_rtx = 0;
|
|
|
|
return error;
|
|
}
|
|
|
|
/* Cork the outqueue so queued chunks are really queued. */
|
|
int sctp_outq_uncork(struct sctp_outq *q)
|
|
{
|
|
int error = 0;
|
|
if (q->cork)
|
|
q->cork = 0;
|
|
error = sctp_outq_flush(q, 0);
|
|
return error;
|
|
}
|
|
|
|
|
|
/*
|
|
* Try to flush an outqueue.
|
|
*
|
|
* Description: Send everything in q which we legally can, subject to
|
|
* congestion limitations.
|
|
* * Note: This function can be called from multiple contexts so appropriate
|
|
* locking concerns must be made. Today we use the sock lock to protect
|
|
* this function.
|
|
*/
|
|
static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
|
|
{
|
|
struct sctp_packet *packet;
|
|
struct sctp_packet singleton;
|
|
struct sctp_association *asoc = q->asoc;
|
|
__u16 sport = asoc->base.bind_addr.port;
|
|
__u16 dport = asoc->peer.port;
|
|
__u32 vtag = asoc->peer.i.init_tag;
|
|
struct sctp_transport *transport = NULL;
|
|
struct sctp_transport *new_transport;
|
|
struct sctp_chunk *chunk, *tmp;
|
|
sctp_xmit_t status;
|
|
int error = 0;
|
|
int start_timer = 0;
|
|
int one_packet = 0;
|
|
|
|
/* These transports have chunks to send. */
|
|
struct list_head transport_list;
|
|
struct list_head *ltransport;
|
|
|
|
INIT_LIST_HEAD(&transport_list);
|
|
packet = NULL;
|
|
|
|
/*
|
|
* 6.10 Bundling
|
|
* ...
|
|
* When bundling control chunks with DATA chunks, an
|
|
* endpoint MUST place control chunks first in the outbound
|
|
* SCTP packet. The transmitter MUST transmit DATA chunks
|
|
* within a SCTP packet in increasing order of TSN.
|
|
* ...
|
|
*/
|
|
|
|
list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
|
|
/* RFC 5061, 5.3
|
|
* F1) This means that until such time as the ASCONF
|
|
* containing the add is acknowledged, the sender MUST
|
|
* NOT use the new IP address as a source for ANY SCTP
|
|
* packet except on carrying an ASCONF Chunk.
|
|
*/
|
|
if (asoc->src_out_of_asoc_ok &&
|
|
chunk->chunk_hdr->type != SCTP_CID_ASCONF)
|
|
continue;
|
|
|
|
list_del_init(&chunk->list);
|
|
|
|
/* Pick the right transport to use. */
|
|
new_transport = chunk->transport;
|
|
|
|
if (!new_transport) {
|
|
/*
|
|
* If we have a prior transport pointer, see if
|
|
* the destination address of the chunk
|
|
* matches the destination address of the
|
|
* current transport. If not a match, then
|
|
* try to look up the transport with a given
|
|
* destination address. We do this because
|
|
* after processing ASCONFs, we may have new
|
|
* transports created.
|
|
*/
|
|
if (transport &&
|
|
sctp_cmp_addr_exact(&chunk->dest,
|
|
&transport->ipaddr))
|
|
new_transport = transport;
|
|
else
|
|
new_transport = sctp_assoc_lookup_paddr(asoc,
|
|
&chunk->dest);
|
|
|
|
/* if we still don't have a new transport, then
|
|
* use the current active path.
|
|
*/
|
|
if (!new_transport)
|
|
new_transport = asoc->peer.active_path;
|
|
} else if ((new_transport->state == SCTP_INACTIVE) ||
|
|
(new_transport->state == SCTP_UNCONFIRMED)) {
|
|
/* If the chunk is Heartbeat or Heartbeat Ack,
|
|
* send it to chunk->transport, even if it's
|
|
* inactive.
|
|
*
|
|
* 3.3.6 Heartbeat Acknowledgement:
|
|
* ...
|
|
* A HEARTBEAT ACK is always sent to the source IP
|
|
* address of the IP datagram containing the
|
|
* HEARTBEAT chunk to which this ack is responding.
|
|
* ...
|
|
*
|
|
* ASCONF_ACKs also must be sent to the source.
|
|
*/
|
|
if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT &&
|
|
chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK &&
|
|
chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK)
|
|
new_transport = asoc->peer.active_path;
|
|
}
|
|
|
|
/* Are we switching transports?
|
|
* Take care of transport locks.
|
|
*/
|
|
if (new_transport != transport) {
|
|
transport = new_transport;
|
|
if (list_empty(&transport->send_ready)) {
|
|
list_add_tail(&transport->send_ready,
|
|
&transport_list);
|
|
}
|
|
packet = &transport->packet;
|
|
sctp_packet_config(packet, vtag,
|
|
asoc->peer.ecn_capable);
|
|
}
|
|
|
|
switch (chunk->chunk_hdr->type) {
|
|
/*
|
|
* 6.10 Bundling
|
|
* ...
|
|
* An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN
|
|
* COMPLETE with any other chunks. [Send them immediately.]
|
|
*/
|
|
case SCTP_CID_INIT:
|
|
case SCTP_CID_INIT_ACK:
|
|
case SCTP_CID_SHUTDOWN_COMPLETE:
|
|
sctp_packet_init(&singleton, transport, sport, dport);
|
|
sctp_packet_config(&singleton, vtag, 0);
|
|
sctp_packet_append_chunk(&singleton, chunk);
|
|
error = sctp_packet_transmit(&singleton);
|
|
if (error < 0)
|
|
return error;
|
|
break;
|
|
|
|
case SCTP_CID_ABORT:
|
|
if (sctp_test_T_bit(chunk)) {
|
|
packet->vtag = asoc->c.my_vtag;
|
|
}
|
|
/* The following chunks are "response" chunks, i.e.
|
|
* they are generated in response to something we
|
|
* received. If we are sending these, then we can
|
|
* send only 1 packet containing these chunks.
|
|
*/
|
|
case SCTP_CID_HEARTBEAT_ACK:
|
|
case SCTP_CID_SHUTDOWN_ACK:
|
|
case SCTP_CID_COOKIE_ACK:
|
|
case SCTP_CID_COOKIE_ECHO:
|
|
case SCTP_CID_ERROR:
|
|
case SCTP_CID_ECN_CWR:
|
|
case SCTP_CID_ASCONF_ACK:
|
|
one_packet = 1;
|
|
/* Fall through */
|
|
|
|
case SCTP_CID_SACK:
|
|
case SCTP_CID_HEARTBEAT:
|
|
case SCTP_CID_SHUTDOWN:
|
|
case SCTP_CID_ECN_ECNE:
|
|
case SCTP_CID_ASCONF:
|
|
case SCTP_CID_FWD_TSN:
|
|
status = sctp_packet_transmit_chunk(packet, chunk,
|
|
one_packet);
|
|
if (status != SCTP_XMIT_OK) {
|
|
/* put the chunk back */
|
|
list_add(&chunk->list, &q->control_chunk_list);
|
|
} else if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) {
|
|
/* PR-SCTP C5) If a FORWARD TSN is sent, the
|
|
* sender MUST assure that at least one T3-rtx
|
|
* timer is running.
|
|
*/
|
|
sctp_transport_reset_timers(transport);
|
|
}
|
|
break;
|
|
|
|
default:
|
|
/* We built a chunk with an illegal type! */
|
|
BUG();
|
|
}
|
|
}
|
|
|
|
if (q->asoc->src_out_of_asoc_ok)
|
|
goto sctp_flush_out;
|
|
|
|
/* Is it OK to send data chunks? */
|
|
switch (asoc->state) {
|
|
case SCTP_STATE_COOKIE_ECHOED:
|
|
/* Only allow bundling when this packet has a COOKIE-ECHO
|
|
* chunk.
|
|
*/
|
|
if (!packet || !packet->has_cookie_echo)
|
|
break;
|
|
|
|
/* fallthru */
|
|
case SCTP_STATE_ESTABLISHED:
|
|
case SCTP_STATE_SHUTDOWN_PENDING:
|
|
case SCTP_STATE_SHUTDOWN_RECEIVED:
|
|
/*
|
|
* RFC 2960 6.1 Transmission of DATA Chunks
|
|
*
|
|
* C) When the time comes for the sender to transmit,
|
|
* before sending new DATA chunks, the sender MUST
|
|
* first transmit any outstanding DATA chunks which
|
|
* are marked for retransmission (limited by the
|
|
* current cwnd).
|
|
*/
|
|
if (!list_empty(&q->retransmit)) {
|
|
if (asoc->peer.retran_path->state == SCTP_UNCONFIRMED)
|
|
goto sctp_flush_out;
|
|
if (transport == asoc->peer.retran_path)
|
|
goto retran;
|
|
|
|
/* Switch transports & prepare the packet. */
|
|
|
|
transport = asoc->peer.retran_path;
|
|
|
|
if (list_empty(&transport->send_ready)) {
|
|
list_add_tail(&transport->send_ready,
|
|
&transport_list);
|
|
}
|
|
|
|
packet = &transport->packet;
|
|
sctp_packet_config(packet, vtag,
|
|
asoc->peer.ecn_capable);
|
|
retran:
|
|
error = sctp_outq_flush_rtx(q, packet,
|
|
rtx_timeout, &start_timer);
|
|
|
|
if (start_timer)
|
|
sctp_transport_reset_timers(transport);
|
|
|
|
/* This can happen on COOKIE-ECHO resend. Only
|
|
* one chunk can get bundled with a COOKIE-ECHO.
|
|
*/
|
|
if (packet->has_cookie_echo)
|
|
goto sctp_flush_out;
|
|
|
|
/* Don't send new data if there is still data
|
|
* waiting to retransmit.
|
|
*/
|
|
if (!list_empty(&q->retransmit))
|
|
goto sctp_flush_out;
|
|
}
|
|
|
|
/* Apply Max.Burst limitation to the current transport in
|
|
* case it will be used for new data. We are going to
|
|
* rest it before we return, but we want to apply the limit
|
|
* to the currently queued data.
|
|
*/
|
|
if (transport)
|
|
sctp_transport_burst_limited(transport);
|
|
|
|
/* Finally, transmit new packets. */
|
|
while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
|
|
/* RFC 2960 6.5 Every DATA chunk MUST carry a valid
|
|
* stream identifier.
|
|
*/
|
|
if (chunk->sinfo.sinfo_stream >=
|
|
asoc->c.sinit_num_ostreams) {
|
|
|
|
/* Mark as failed send. */
|
|
sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM);
|
|
sctp_chunk_free(chunk);
|
|
continue;
|
|
}
|
|
|
|
/* Has this chunk expired? */
|
|
if (sctp_chunk_abandoned(chunk)) {
|
|
sctp_chunk_fail(chunk, 0);
|
|
sctp_chunk_free(chunk);
|
|
continue;
|
|
}
|
|
|
|
/* If there is a specified transport, use it.
|
|
* Otherwise, we want to use the active path.
|
|
*/
|
|
new_transport = chunk->transport;
|
|
if (!new_transport ||
|
|
((new_transport->state == SCTP_INACTIVE) ||
|
|
(new_transport->state == SCTP_UNCONFIRMED)))
|
|
new_transport = asoc->peer.active_path;
|
|
if (new_transport->state == SCTP_UNCONFIRMED)
|
|
continue;
|
|
|
|
/* Change packets if necessary. */
|
|
if (new_transport != transport) {
|
|
transport = new_transport;
|
|
|
|
/* Schedule to have this transport's
|
|
* packet flushed.
|
|
*/
|
|
if (list_empty(&transport->send_ready)) {
|
|
list_add_tail(&transport->send_ready,
|
|
&transport_list);
|
|
}
|
|
|
|
packet = &transport->packet;
|
|
sctp_packet_config(packet, vtag,
|
|
asoc->peer.ecn_capable);
|
|
/* We've switched transports, so apply the
|
|
* Burst limit to the new transport.
|
|
*/
|
|
sctp_transport_burst_limited(transport);
|
|
}
|
|
|
|
SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ",
|
|
q, chunk,
|
|
chunk && chunk->chunk_hdr ?
|
|
sctp_cname(SCTP_ST_CHUNK(
|
|
chunk->chunk_hdr->type))
|
|
: "Illegal Chunk");
|
|
|
|
SCTP_DEBUG_PRINTK("TX TSN 0x%x skb->head "
|
|
"%p skb->users %d.\n",
|
|
ntohl(chunk->subh.data_hdr->tsn),
|
|
chunk->skb ?chunk->skb->head : NULL,
|
|
chunk->skb ?
|
|
atomic_read(&chunk->skb->users) : -1);
|
|
|
|
/* Add the chunk to the packet. */
|
|
status = sctp_packet_transmit_chunk(packet, chunk, 0);
|
|
|
|
switch (status) {
|
|
case SCTP_XMIT_PMTU_FULL:
|
|
case SCTP_XMIT_RWND_FULL:
|
|
case SCTP_XMIT_NAGLE_DELAY:
|
|
/* We could not append this chunk, so put
|
|
* the chunk back on the output queue.
|
|
*/
|
|
SCTP_DEBUG_PRINTK("sctp_outq_flush: could "
|
|
"not transmit TSN: 0x%x, status: %d\n",
|
|
ntohl(chunk->subh.data_hdr->tsn),
|
|
status);
|
|
sctp_outq_head_data(q, chunk);
|
|
goto sctp_flush_out;
|
|
break;
|
|
|
|
case SCTP_XMIT_OK:
|
|
/* The sender is in the SHUTDOWN-PENDING state,
|
|
* The sender MAY set the I-bit in the DATA
|
|
* chunk header.
|
|
*/
|
|
if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING)
|
|
chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM;
|
|
|
|
break;
|
|
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
/* BUG: We assume that the sctp_packet_transmit()
|
|
* call below will succeed all the time and add the
|
|
* chunk to the transmitted list and restart the
|
|
* timers.
|
|
* It is possible that the call can fail under OOM
|
|
* conditions.
|
|
*
|
|
* Is this really a problem? Won't this behave
|
|
* like a lost TSN?
|
|
*/
|
|
list_add_tail(&chunk->transmitted_list,
|
|
&transport->transmitted);
|
|
|
|
sctp_transport_reset_timers(transport);
|
|
|
|
q->empty = 0;
|
|
|
|
/* Only let one DATA chunk get bundled with a
|
|
* COOKIE-ECHO chunk.
|
|
*/
|
|
if (packet->has_cookie_echo)
|
|
goto sctp_flush_out;
|
|
}
|
|
break;
|
|
|
|
default:
|
|
/* Do nothing. */
|
|
break;
|
|
}
|
|
|
|
sctp_flush_out:
|
|
|
|
/* Before returning, examine all the transports touched in
|
|
* this call. Right now, we bluntly force clear all the
|
|
* transports. Things might change after we implement Nagle.
|
|
* But such an examination is still required.
|
|
*
|
|
* --xguo
|
|
*/
|
|
while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL ) {
|
|
struct sctp_transport *t = list_entry(ltransport,
|
|
struct sctp_transport,
|
|
send_ready);
|
|
packet = &t->packet;
|
|
if (!sctp_packet_empty(packet))
|
|
error = sctp_packet_transmit(packet);
|
|
|
|
/* Clear the burst limited state, if any */
|
|
sctp_transport_burst_reset(t);
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
/* Update unack_data based on the incoming SACK chunk */
|
|
static void sctp_sack_update_unack_data(struct sctp_association *assoc,
|
|
struct sctp_sackhdr *sack)
|
|
{
|
|
sctp_sack_variable_t *frags;
|
|
__u16 unack_data;
|
|
int i;
|
|
|
|
unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1;
|
|
|
|
frags = sack->variable;
|
|
for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) {
|
|
unack_data -= ((ntohs(frags[i].gab.end) -
|
|
ntohs(frags[i].gab.start) + 1));
|
|
}
|
|
|
|
assoc->unack_data = unack_data;
|
|
}
|
|
|
|
/* This is where we REALLY process a SACK.
|
|
*
|
|
* Process the SACK against the outqueue. Mostly, this just frees
|
|
* things off the transmitted queue.
|
|
*/
|
|
int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack)
|
|
{
|
|
struct sctp_association *asoc = q->asoc;
|
|
struct sctp_transport *transport;
|
|
struct sctp_chunk *tchunk = NULL;
|
|
struct list_head *lchunk, *transport_list, *temp;
|
|
sctp_sack_variable_t *frags = sack->variable;
|
|
__u32 sack_ctsn, ctsn, tsn;
|
|
__u32 highest_tsn, highest_new_tsn;
|
|
__u32 sack_a_rwnd;
|
|
unsigned int outstanding;
|
|
struct sctp_transport *primary = asoc->peer.primary_path;
|
|
int count_of_newacks = 0;
|
|
int gap_ack_blocks;
|
|
u8 accum_moved = 0;
|
|
|
|
/* Grab the association's destination address list. */
|
|
transport_list = &asoc->peer.transport_addr_list;
|
|
|
|
sack_ctsn = ntohl(sack->cum_tsn_ack);
|
|
gap_ack_blocks = ntohs(sack->num_gap_ack_blocks);
|
|
/*
|
|
* SFR-CACC algorithm:
|
|
* On receipt of a SACK the sender SHOULD execute the
|
|
* following statements.
|
|
*
|
|
* 1) If the cumulative ack in the SACK passes next tsn_at_change
|
|
* on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be
|
|
* cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for
|
|
* all destinations.
|
|
* 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE
|
|
* is set the receiver of the SACK MUST take the following actions:
|
|
*
|
|
* A) Initialize the cacc_saw_newack to 0 for all destination
|
|
* addresses.
|
|
*
|
|
* Only bother if changeover_active is set. Otherwise, this is
|
|
* totally suboptimal to do on every SACK.
|
|
*/
|
|
if (primary->cacc.changeover_active) {
|
|
u8 clear_cycling = 0;
|
|
|
|
if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) {
|
|
primary->cacc.changeover_active = 0;
|
|
clear_cycling = 1;
|
|
}
|
|
|
|
if (clear_cycling || gap_ack_blocks) {
|
|
list_for_each_entry(transport, transport_list,
|
|
transports) {
|
|
if (clear_cycling)
|
|
transport->cacc.cycling_changeover = 0;
|
|
if (gap_ack_blocks)
|
|
transport->cacc.cacc_saw_newack = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Get the highest TSN in the sack. */
|
|
highest_tsn = sack_ctsn;
|
|
if (gap_ack_blocks)
|
|
highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end);
|
|
|
|
if (TSN_lt(asoc->highest_sacked, highest_tsn))
|
|
asoc->highest_sacked = highest_tsn;
|
|
|
|
highest_new_tsn = sack_ctsn;
|
|
|
|
/* Run through the retransmit queue. Credit bytes received
|
|
* and free those chunks that we can.
|
|
*/
|
|
sctp_check_transmitted(q, &q->retransmit, NULL, sack, &highest_new_tsn);
|
|
|
|
/* Run through the transmitted queue.
|
|
* Credit bytes received and free those chunks which we can.
|
|
*
|
|
* This is a MASSIVE candidate for optimization.
|
|
*/
|
|
list_for_each_entry(transport, transport_list, transports) {
|
|
sctp_check_transmitted(q, &transport->transmitted,
|
|
transport, sack, &highest_new_tsn);
|
|
/*
|
|
* SFR-CACC algorithm:
|
|
* C) Let count_of_newacks be the number of
|
|
* destinations for which cacc_saw_newack is set.
|
|
*/
|
|
if (transport->cacc.cacc_saw_newack)
|
|
count_of_newacks ++;
|
|
}
|
|
|
|
/* Move the Cumulative TSN Ack Point if appropriate. */
|
|
if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) {
|
|
asoc->ctsn_ack_point = sack_ctsn;
|
|
accum_moved = 1;
|
|
}
|
|
|
|
if (gap_ack_blocks) {
|
|
|
|
if (asoc->fast_recovery && accum_moved)
|
|
highest_new_tsn = highest_tsn;
|
|
|
|
list_for_each_entry(transport, transport_list, transports)
|
|
sctp_mark_missing(q, &transport->transmitted, transport,
|
|
highest_new_tsn, count_of_newacks);
|
|
}
|
|
|
|
/* Update unack_data field in the assoc. */
|
|
sctp_sack_update_unack_data(asoc, sack);
|
|
|
|
ctsn = asoc->ctsn_ack_point;
|
|
|
|
/* Throw away stuff rotting on the sack queue. */
|
|
list_for_each_safe(lchunk, temp, &q->sacked) {
|
|
tchunk = list_entry(lchunk, struct sctp_chunk,
|
|
transmitted_list);
|
|
tsn = ntohl(tchunk->subh.data_hdr->tsn);
|
|
if (TSN_lte(tsn, ctsn)) {
|
|
list_del_init(&tchunk->transmitted_list);
|
|
sctp_chunk_free(tchunk);
|
|
}
|
|
}
|
|
|
|
/* ii) Set rwnd equal to the newly received a_rwnd minus the
|
|
* number of bytes still outstanding after processing the
|
|
* Cumulative TSN Ack and the Gap Ack Blocks.
|
|
*/
|
|
|
|
sack_a_rwnd = ntohl(sack->a_rwnd);
|
|
outstanding = q->outstanding_bytes;
|
|
|
|
if (outstanding < sack_a_rwnd)
|
|
sack_a_rwnd -= outstanding;
|
|
else
|
|
sack_a_rwnd = 0;
|
|
|
|
asoc->peer.rwnd = sack_a_rwnd;
|
|
|
|
sctp_generate_fwdtsn(q, sack_ctsn);
|
|
|
|
SCTP_DEBUG_PRINTK("%s: sack Cumulative TSN Ack is 0x%x.\n",
|
|
__func__, sack_ctsn);
|
|
SCTP_DEBUG_PRINTK("%s: Cumulative TSN Ack of association, "
|
|
"%p is 0x%x. Adv peer ack point: 0x%x\n",
|
|
__func__, asoc, ctsn, asoc->adv_peer_ack_point);
|
|
|
|
/* See if all chunks are acked.
|
|
* Make sure the empty queue handler will get run later.
|
|
*/
|
|
q->empty = (list_empty(&q->out_chunk_list) &&
|
|
list_empty(&q->retransmit));
|
|
if (!q->empty)
|
|
goto finish;
|
|
|
|
list_for_each_entry(transport, transport_list, transports) {
|
|
q->empty = q->empty && list_empty(&transport->transmitted);
|
|
if (!q->empty)
|
|
goto finish;
|
|
}
|
|
|
|
SCTP_DEBUG_PRINTK("sack queue is empty.\n");
|
|
finish:
|
|
return q->empty;
|
|
}
|
|
|
|
/* Is the outqueue empty? */
|
|
int sctp_outq_is_empty(const struct sctp_outq *q)
|
|
{
|
|
return q->empty;
|
|
}
|
|
|
|
/********************************************************************
|
|
* 2nd Level Abstractions
|
|
********************************************************************/
|
|
|
|
/* Go through a transport's transmitted list or the association's retransmit
|
|
* list and move chunks that are acked by the Cumulative TSN Ack to q->sacked.
|
|
* The retransmit list will not have an associated transport.
|
|
*
|
|
* I added coherent debug information output. --xguo
|
|
*
|
|
* Instead of printing 'sacked' or 'kept' for each TSN on the
|
|
* transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5.
|
|
* KEPT TSN6-TSN7, etc.
|
|
*/
|
|
static void sctp_check_transmitted(struct sctp_outq *q,
|
|
struct list_head *transmitted_queue,
|
|
struct sctp_transport *transport,
|
|
struct sctp_sackhdr *sack,
|
|
__u32 *highest_new_tsn_in_sack)
|
|
{
|
|
struct list_head *lchunk;
|
|
struct sctp_chunk *tchunk;
|
|
struct list_head tlist;
|
|
__u32 tsn;
|
|
__u32 sack_ctsn;
|
|
__u32 rtt;
|
|
__u8 restart_timer = 0;
|
|
int bytes_acked = 0;
|
|
int migrate_bytes = 0;
|
|
|
|
/* These state variables are for coherent debug output. --xguo */
|
|
|
|
#if SCTP_DEBUG
|
|
__u32 dbg_ack_tsn = 0; /* An ACKed TSN range starts here... */
|
|
__u32 dbg_last_ack_tsn = 0; /* ...and finishes here. */
|
|
__u32 dbg_kept_tsn = 0; /* An un-ACKed range starts here... */
|
|
__u32 dbg_last_kept_tsn = 0; /* ...and finishes here. */
|
|
|
|
/* 0 : The last TSN was ACKed.
|
|
* 1 : The last TSN was NOT ACKed (i.e. KEPT).
|
|
* -1: We need to initialize.
|
|
*/
|
|
int dbg_prt_state = -1;
|
|
#endif /* SCTP_DEBUG */
|
|
|
|
sack_ctsn = ntohl(sack->cum_tsn_ack);
|
|
|
|
INIT_LIST_HEAD(&tlist);
|
|
|
|
/* The while loop will skip empty transmitted queues. */
|
|
while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) {
|
|
tchunk = list_entry(lchunk, struct sctp_chunk,
|
|
transmitted_list);
|
|
|
|
if (sctp_chunk_abandoned(tchunk)) {
|
|
/* Move the chunk to abandoned list. */
|
|
sctp_insert_list(&q->abandoned, lchunk);
|
|
|
|
/* If this chunk has not been acked, stop
|
|
* considering it as 'outstanding'.
|
|
*/
|
|
if (!tchunk->tsn_gap_acked) {
|
|
if (tchunk->transport)
|
|
tchunk->transport->flight_size -=
|
|
sctp_data_size(tchunk);
|
|
q->outstanding_bytes -= sctp_data_size(tchunk);
|
|
}
|
|
continue;
|
|
}
|
|
|
|
tsn = ntohl(tchunk->subh.data_hdr->tsn);
|
|
if (sctp_acked(sack, tsn)) {
|
|
/* If this queue is the retransmit queue, the
|
|
* retransmit timer has already reclaimed
|
|
* the outstanding bytes for this chunk, so only
|
|
* count bytes associated with a transport.
|
|
*/
|
|
if (transport) {
|
|
/* If this chunk is being used for RTT
|
|
* measurement, calculate the RTT and update
|
|
* the RTO using this value.
|
|
*
|
|
* 6.3.1 C5) Karn's algorithm: RTT measurements
|
|
* MUST NOT be made using packets that were
|
|
* retransmitted (and thus for which it is
|
|
* ambiguous whether the reply was for the
|
|
* first instance of the packet or a later
|
|
* instance).
|
|
*/
|
|
if (!tchunk->tsn_gap_acked &&
|
|
tchunk->rtt_in_progress) {
|
|
tchunk->rtt_in_progress = 0;
|
|
rtt = jiffies - tchunk->sent_at;
|
|
sctp_transport_update_rto(transport,
|
|
rtt);
|
|
}
|
|
}
|
|
|
|
/* If the chunk hasn't been marked as ACKED,
|
|
* mark it and account bytes_acked if the
|
|
* chunk had a valid transport (it will not
|
|
* have a transport if ASCONF had deleted it
|
|
* while DATA was outstanding).
|
|
*/
|
|
if (!tchunk->tsn_gap_acked) {
|
|
tchunk->tsn_gap_acked = 1;
|
|
*highest_new_tsn_in_sack = tsn;
|
|
bytes_acked += sctp_data_size(tchunk);
|
|
if (!tchunk->transport)
|
|
migrate_bytes += sctp_data_size(tchunk);
|
|
}
|
|
|
|
if (TSN_lte(tsn, sack_ctsn)) {
|
|
/* RFC 2960 6.3.2 Retransmission Timer Rules
|
|
*
|
|
* R3) Whenever a SACK is received
|
|
* that acknowledges the DATA chunk
|
|
* with the earliest outstanding TSN
|
|
* for that address, restart T3-rtx
|
|
* timer for that address with its
|
|
* current RTO.
|
|
*/
|
|
restart_timer = 1;
|
|
|
|
if (!tchunk->tsn_gap_acked) {
|
|
/*
|
|
* SFR-CACC algorithm:
|
|
* 2) If the SACK contains gap acks
|
|
* and the flag CHANGEOVER_ACTIVE is
|
|
* set the receiver of the SACK MUST
|
|
* take the following action:
|
|
*
|
|
* B) For each TSN t being acked that
|
|
* has not been acked in any SACK so
|
|
* far, set cacc_saw_newack to 1 for
|
|
* the destination that the TSN was
|
|
* sent to.
|
|
*/
|
|
if (transport &&
|
|
sack->num_gap_ack_blocks &&
|
|
q->asoc->peer.primary_path->cacc.
|
|
changeover_active)
|
|
transport->cacc.cacc_saw_newack
|
|
= 1;
|
|
}
|
|
|
|
list_add_tail(&tchunk->transmitted_list,
|
|
&q->sacked);
|
|
} else {
|
|
/* RFC2960 7.2.4, sctpimpguide-05 2.8.2
|
|
* M2) Each time a SACK arrives reporting
|
|
* 'Stray DATA chunk(s)' record the highest TSN
|
|
* reported as newly acknowledged, call this
|
|
* value 'HighestTSNinSack'. A newly
|
|
* acknowledged DATA chunk is one not
|
|
* previously acknowledged in a SACK.
|
|
*
|
|
* When the SCTP sender of data receives a SACK
|
|
* chunk that acknowledges, for the first time,
|
|
* the receipt of a DATA chunk, all the still
|
|
* unacknowledged DATA chunks whose TSN is
|
|
* older than that newly acknowledged DATA
|
|
* chunk, are qualified as 'Stray DATA chunks'.
|
|
*/
|
|
list_add_tail(lchunk, &tlist);
|
|
}
|
|
|
|
#if SCTP_DEBUG
|
|
switch (dbg_prt_state) {
|
|
case 0: /* last TSN was ACKed */
|
|
if (dbg_last_ack_tsn + 1 == tsn) {
|
|
/* This TSN belongs to the
|
|
* current ACK range.
|
|
*/
|
|
break;
|
|
}
|
|
|
|
if (dbg_last_ack_tsn != dbg_ack_tsn) {
|
|
/* Display the end of the
|
|
* current range.
|
|
*/
|
|
SCTP_DEBUG_PRINTK_CONT("-%08x",
|
|
dbg_last_ack_tsn);
|
|
}
|
|
|
|
/* Start a new range. */
|
|
SCTP_DEBUG_PRINTK_CONT(",%08x", tsn);
|
|
dbg_ack_tsn = tsn;
|
|
break;
|
|
|
|
case 1: /* The last TSN was NOT ACKed. */
|
|
if (dbg_last_kept_tsn != dbg_kept_tsn) {
|
|
/* Display the end of current range. */
|
|
SCTP_DEBUG_PRINTK_CONT("-%08x",
|
|
dbg_last_kept_tsn);
|
|
}
|
|
|
|
SCTP_DEBUG_PRINTK_CONT("\n");
|
|
|
|
/* FALL THROUGH... */
|
|
default:
|
|
/* This is the first-ever TSN we examined. */
|
|
/* Start a new range of ACK-ed TSNs. */
|
|
SCTP_DEBUG_PRINTK("ACKed: %08x", tsn);
|
|
dbg_prt_state = 0;
|
|
dbg_ack_tsn = tsn;
|
|
}
|
|
|
|
dbg_last_ack_tsn = tsn;
|
|
#endif /* SCTP_DEBUG */
|
|
|
|
} else {
|
|
if (tchunk->tsn_gap_acked) {
|
|
SCTP_DEBUG_PRINTK("%s: Receiver reneged on "
|
|
"data TSN: 0x%x\n",
|
|
__func__,
|
|
tsn);
|
|
tchunk->tsn_gap_acked = 0;
|
|
|
|
if (tchunk->transport)
|
|
bytes_acked -= sctp_data_size(tchunk);
|
|
|
|
/* RFC 2960 6.3.2 Retransmission Timer Rules
|
|
*
|
|
* R4) Whenever a SACK is received missing a
|
|
* TSN that was previously acknowledged via a
|
|
* Gap Ack Block, start T3-rtx for the
|
|
* destination address to which the DATA
|
|
* chunk was originally
|
|
* transmitted if it is not already running.
|
|
*/
|
|
restart_timer = 1;
|
|
}
|
|
|
|
list_add_tail(lchunk, &tlist);
|
|
|
|
#if SCTP_DEBUG
|
|
/* See the above comments on ACK-ed TSNs. */
|
|
switch (dbg_prt_state) {
|
|
case 1:
|
|
if (dbg_last_kept_tsn + 1 == tsn)
|
|
break;
|
|
|
|
if (dbg_last_kept_tsn != dbg_kept_tsn)
|
|
SCTP_DEBUG_PRINTK_CONT("-%08x",
|
|
dbg_last_kept_tsn);
|
|
|
|
SCTP_DEBUG_PRINTK_CONT(",%08x", tsn);
|
|
dbg_kept_tsn = tsn;
|
|
break;
|
|
|
|
case 0:
|
|
if (dbg_last_ack_tsn != dbg_ack_tsn)
|
|
SCTP_DEBUG_PRINTK_CONT("-%08x",
|
|
dbg_last_ack_tsn);
|
|
SCTP_DEBUG_PRINTK_CONT("\n");
|
|
|
|
/* FALL THROUGH... */
|
|
default:
|
|
SCTP_DEBUG_PRINTK("KEPT: %08x",tsn);
|
|
dbg_prt_state = 1;
|
|
dbg_kept_tsn = tsn;
|
|
}
|
|
|
|
dbg_last_kept_tsn = tsn;
|
|
#endif /* SCTP_DEBUG */
|
|
}
|
|
}
|
|
|
|
#if SCTP_DEBUG
|
|
/* Finish off the last range, displaying its ending TSN. */
|
|
switch (dbg_prt_state) {
|
|
case 0:
|
|
if (dbg_last_ack_tsn != dbg_ack_tsn) {
|
|
SCTP_DEBUG_PRINTK_CONT("-%08x\n", dbg_last_ack_tsn);
|
|
} else {
|
|
SCTP_DEBUG_PRINTK_CONT("\n");
|
|
}
|
|
break;
|
|
|
|
case 1:
|
|
if (dbg_last_kept_tsn != dbg_kept_tsn) {
|
|
SCTP_DEBUG_PRINTK_CONT("-%08x\n", dbg_last_kept_tsn);
|
|
} else {
|
|
SCTP_DEBUG_PRINTK_CONT("\n");
|
|
}
|
|
}
|
|
#endif /* SCTP_DEBUG */
|
|
if (transport) {
|
|
if (bytes_acked) {
|
|
struct sctp_association *asoc = transport->asoc;
|
|
|
|
/* We may have counted DATA that was migrated
|
|
* to this transport due to DEL-IP operation.
|
|
* Subtract those bytes, since the were never
|
|
* send on this transport and shouldn't be
|
|
* credited to this transport.
|
|
*/
|
|
bytes_acked -= migrate_bytes;
|
|
|
|
/* 8.2. When an outstanding TSN is acknowledged,
|
|
* the endpoint shall clear the error counter of
|
|
* the destination transport address to which the
|
|
* DATA chunk was last sent.
|
|
* The association's overall error counter is
|
|
* also cleared.
|
|
*/
|
|
transport->error_count = 0;
|
|
transport->asoc->overall_error_count = 0;
|
|
|
|
/*
|
|
* While in SHUTDOWN PENDING, we may have started
|
|
* the T5 shutdown guard timer after reaching the
|
|
* retransmission limit. Stop that timer as soon
|
|
* as the receiver acknowledged any data.
|
|
*/
|
|
if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING &&
|
|
del_timer(&asoc->timers
|
|
[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]))
|
|
sctp_association_put(asoc);
|
|
|
|
/* Mark the destination transport address as
|
|
* active if it is not so marked.
|
|
*/
|
|
if ((transport->state == SCTP_INACTIVE) ||
|
|
(transport->state == SCTP_UNCONFIRMED)) {
|
|
sctp_assoc_control_transport(
|
|
transport->asoc,
|
|
transport,
|
|
SCTP_TRANSPORT_UP,
|
|
SCTP_RECEIVED_SACK);
|
|
}
|
|
|
|
sctp_transport_raise_cwnd(transport, sack_ctsn,
|
|
bytes_acked);
|
|
|
|
transport->flight_size -= bytes_acked;
|
|
if (transport->flight_size == 0)
|
|
transport->partial_bytes_acked = 0;
|
|
q->outstanding_bytes -= bytes_acked + migrate_bytes;
|
|
} else {
|
|
/* RFC 2960 6.1, sctpimpguide-06 2.15.2
|
|
* When a sender is doing zero window probing, it
|
|
* should not timeout the association if it continues
|
|
* to receive new packets from the receiver. The
|
|
* reason is that the receiver MAY keep its window
|
|
* closed for an indefinite time.
|
|
* A sender is doing zero window probing when the
|
|
* receiver's advertised window is zero, and there is
|
|
* only one data chunk in flight to the receiver.
|
|
*
|
|
* Allow the association to timeout while in SHUTDOWN
|
|
* PENDING or SHUTDOWN RECEIVED in case the receiver
|
|
* stays in zero window mode forever.
|
|
*/
|
|
if (!q->asoc->peer.rwnd &&
|
|
!list_empty(&tlist) &&
|
|
(sack_ctsn+2 == q->asoc->next_tsn) &&
|
|
q->asoc->state < SCTP_STATE_SHUTDOWN_PENDING) {
|
|
SCTP_DEBUG_PRINTK("%s: SACK received for zero "
|
|
"window probe: %u\n",
|
|
__func__, sack_ctsn);
|
|
q->asoc->overall_error_count = 0;
|
|
transport->error_count = 0;
|
|
}
|
|
}
|
|
|
|
/* RFC 2960 6.3.2 Retransmission Timer Rules
|
|
*
|
|
* R2) Whenever all outstanding data sent to an address have
|
|
* been acknowledged, turn off the T3-rtx timer of that
|
|
* address.
|
|
*/
|
|
if (!transport->flight_size) {
|
|
if (timer_pending(&transport->T3_rtx_timer) &&
|
|
del_timer(&transport->T3_rtx_timer)) {
|
|
sctp_transport_put(transport);
|
|
}
|
|
} else if (restart_timer) {
|
|
if (!mod_timer(&transport->T3_rtx_timer,
|
|
jiffies + transport->rto))
|
|
sctp_transport_hold(transport);
|
|
}
|
|
}
|
|
|
|
list_splice(&tlist, transmitted_queue);
|
|
}
|
|
|
|
/* Mark chunks as missing and consequently may get retransmitted. */
|
|
static void sctp_mark_missing(struct sctp_outq *q,
|
|
struct list_head *transmitted_queue,
|
|
struct sctp_transport *transport,
|
|
__u32 highest_new_tsn_in_sack,
|
|
int count_of_newacks)
|
|
{
|
|
struct sctp_chunk *chunk;
|
|
__u32 tsn;
|
|
char do_fast_retransmit = 0;
|
|
struct sctp_association *asoc = q->asoc;
|
|
struct sctp_transport *primary = asoc->peer.primary_path;
|
|
|
|
list_for_each_entry(chunk, transmitted_queue, transmitted_list) {
|
|
|
|
tsn = ntohl(chunk->subh.data_hdr->tsn);
|
|
|
|
/* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all
|
|
* 'Unacknowledged TSN's', if the TSN number of an
|
|
* 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack'
|
|
* value, increment the 'TSN.Missing.Report' count on that
|
|
* chunk if it has NOT been fast retransmitted or marked for
|
|
* fast retransmit already.
|
|
*/
|
|
if (chunk->fast_retransmit == SCTP_CAN_FRTX &&
|
|
!chunk->tsn_gap_acked &&
|
|
TSN_lt(tsn, highest_new_tsn_in_sack)) {
|
|
|
|
/* SFR-CACC may require us to skip marking
|
|
* this chunk as missing.
|
|
*/
|
|
if (!transport || !sctp_cacc_skip(primary,
|
|
chunk->transport,
|
|
count_of_newacks, tsn)) {
|
|
chunk->tsn_missing_report++;
|
|
|
|
SCTP_DEBUG_PRINTK(
|
|
"%s: TSN 0x%x missing counter: %d\n",
|
|
__func__, tsn,
|
|
chunk->tsn_missing_report);
|
|
}
|
|
}
|
|
/*
|
|
* M4) If any DATA chunk is found to have a
|
|
* 'TSN.Missing.Report'
|
|
* value larger than or equal to 3, mark that chunk for
|
|
* retransmission and start the fast retransmit procedure.
|
|
*/
|
|
|
|
if (chunk->tsn_missing_report >= 3) {
|
|
chunk->fast_retransmit = SCTP_NEED_FRTX;
|
|
do_fast_retransmit = 1;
|
|
}
|
|
}
|
|
|
|
if (transport) {
|
|
if (do_fast_retransmit)
|
|
sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX);
|
|
|
|
SCTP_DEBUG_PRINTK("%s: transport: %p, cwnd: %d, "
|
|
"ssthresh: %d, flight_size: %d, pba: %d\n",
|
|
__func__, transport, transport->cwnd,
|
|
transport->ssthresh, transport->flight_size,
|
|
transport->partial_bytes_acked);
|
|
}
|
|
}
|
|
|
|
/* Is the given TSN acked by this packet? */
|
|
static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn)
|
|
{
|
|
int i;
|
|
sctp_sack_variable_t *frags;
|
|
__u16 gap;
|
|
__u32 ctsn = ntohl(sack->cum_tsn_ack);
|
|
|
|
if (TSN_lte(tsn, ctsn))
|
|
goto pass;
|
|
|
|
/* 3.3.4 Selective Acknowledgement (SACK) (3):
|
|
*
|
|
* Gap Ack Blocks:
|
|
* These fields contain the Gap Ack Blocks. They are repeated
|
|
* for each Gap Ack Block up to the number of Gap Ack Blocks
|
|
* defined in the Number of Gap Ack Blocks field. All DATA
|
|
* chunks with TSNs greater than or equal to (Cumulative TSN
|
|
* Ack + Gap Ack Block Start) and less than or equal to
|
|
* (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack
|
|
* Block are assumed to have been received correctly.
|
|
*/
|
|
|
|
frags = sack->variable;
|
|
gap = tsn - ctsn;
|
|
for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) {
|
|
if (TSN_lte(ntohs(frags[i].gab.start), gap) &&
|
|
TSN_lte(gap, ntohs(frags[i].gab.end)))
|
|
goto pass;
|
|
}
|
|
|
|
return 0;
|
|
pass:
|
|
return 1;
|
|
}
|
|
|
|
static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist,
|
|
int nskips, __be16 stream)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < nskips; i++) {
|
|
if (skiplist[i].stream == stream)
|
|
return i;
|
|
}
|
|
return i;
|
|
}
|
|
|
|
/* Create and add a fwdtsn chunk to the outq's control queue if needed. */
|
|
static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn)
|
|
{
|
|
struct sctp_association *asoc = q->asoc;
|
|
struct sctp_chunk *ftsn_chunk = NULL;
|
|
struct sctp_fwdtsn_skip ftsn_skip_arr[10];
|
|
int nskips = 0;
|
|
int skip_pos = 0;
|
|
__u32 tsn;
|
|
struct sctp_chunk *chunk;
|
|
struct list_head *lchunk, *temp;
|
|
|
|
if (!asoc->peer.prsctp_capable)
|
|
return;
|
|
|
|
/* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the
|
|
* received SACK.
|
|
*
|
|
* If (Advanced.Peer.Ack.Point < SackCumAck), then update
|
|
* Advanced.Peer.Ack.Point to be equal to SackCumAck.
|
|
*/
|
|
if (TSN_lt(asoc->adv_peer_ack_point, ctsn))
|
|
asoc->adv_peer_ack_point = ctsn;
|
|
|
|
/* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point"
|
|
* locally, that is, to move "Advanced.Peer.Ack.Point" up as long as
|
|
* the chunk next in the out-queue space is marked as "abandoned" as
|
|
* shown in the following example:
|
|
*
|
|
* Assuming that a SACK arrived with the Cumulative TSN ACK 102
|
|
* and the Advanced.Peer.Ack.Point is updated to this value:
|
|
*
|
|
* out-queue at the end of ==> out-queue after Adv.Ack.Point
|
|
* normal SACK processing local advancement
|
|
* ... ...
|
|
* Adv.Ack.Pt-> 102 acked 102 acked
|
|
* 103 abandoned 103 abandoned
|
|
* 104 abandoned Adv.Ack.P-> 104 abandoned
|
|
* 105 105
|
|
* 106 acked 106 acked
|
|
* ... ...
|
|
*
|
|
* In this example, the data sender successfully advanced the
|
|
* "Advanced.Peer.Ack.Point" from 102 to 104 locally.
|
|
*/
|
|
list_for_each_safe(lchunk, temp, &q->abandoned) {
|
|
chunk = list_entry(lchunk, struct sctp_chunk,
|
|
transmitted_list);
|
|
tsn = ntohl(chunk->subh.data_hdr->tsn);
|
|
|
|
/* Remove any chunks in the abandoned queue that are acked by
|
|
* the ctsn.
|
|
*/
|
|
if (TSN_lte(tsn, ctsn)) {
|
|
list_del_init(lchunk);
|
|
sctp_chunk_free(chunk);
|
|
} else {
|
|
if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) {
|
|
asoc->adv_peer_ack_point = tsn;
|
|
if (chunk->chunk_hdr->flags &
|
|
SCTP_DATA_UNORDERED)
|
|
continue;
|
|
skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0],
|
|
nskips,
|
|
chunk->subh.data_hdr->stream);
|
|
ftsn_skip_arr[skip_pos].stream =
|
|
chunk->subh.data_hdr->stream;
|
|
ftsn_skip_arr[skip_pos].ssn =
|
|
chunk->subh.data_hdr->ssn;
|
|
if (skip_pos == nskips)
|
|
nskips++;
|
|
if (nskips == 10)
|
|
break;
|
|
} else
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point"
|
|
* is greater than the Cumulative TSN ACK carried in the received
|
|
* SACK, the data sender MUST send the data receiver a FORWARD TSN
|
|
* chunk containing the latest value of the
|
|
* "Advanced.Peer.Ack.Point".
|
|
*
|
|
* C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD
|
|
* list each stream and sequence number in the forwarded TSN. This
|
|
* information will enable the receiver to easily find any
|
|
* stranded TSN's waiting on stream reorder queues. Each stream
|
|
* SHOULD only be reported once; this means that if multiple
|
|
* abandoned messages occur in the same stream then only the
|
|
* highest abandoned stream sequence number is reported. If the
|
|
* total size of the FORWARD TSN does NOT fit in a single MTU then
|
|
* the sender of the FORWARD TSN SHOULD lower the
|
|
* Advanced.Peer.Ack.Point to the last TSN that will fit in a
|
|
* single MTU.
|
|
*/
|
|
if (asoc->adv_peer_ack_point > ctsn)
|
|
ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point,
|
|
nskips, &ftsn_skip_arr[0]);
|
|
|
|
if (ftsn_chunk) {
|
|
list_add_tail(&ftsn_chunk->list, &q->control_chunk_list);
|
|
SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
|
|
}
|
|
}
|