Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
new file mode 100644
index 0000000..1b2d4adc
--- /dev/null
+++ b/net/sctp/outqueue.c
@@ -0,0 +1,1734 @@
+/* SCTP kernel reference Implementation
+ * (C) Copyright IBM Corp. 2001, 2004
+ * Copyright (c) 1999-2000 Cisco, Inc.
+ * Copyright (c) 1999-2001 Motorola, Inc.
+ * Copyright (c) 2001-2003 Intel Corp.
+ *
+ * This file is part of the SCTP kernel reference Implementation
+ *
+ * These functions implement the sctp_outq class. The outqueue handles
+ * bundling and queueing of outgoing SCTP chunks.
+ *
+ * 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:
+ * La Monte H.P. Yarroll <piggy@acm.org>
+ * Karl Knutson <karl@athena.chicago.il.us>
+ * Perry Melange <pmelange@null.cc.uic.edu>
+ * Xingang Guo <xingang.guo@intel.com>
+ * Hui Huang <hui.huang@nokia.com>
+ * Sridhar Samudrala <sri@us.ibm.com>
+ * Jon Grimm <jgrimm@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/list.h> /* For struct list_head */
+#include <linux/socket.h>
+#include <linux/ip.h>
+#include <net/sock.h> /* For skb_set_owner_w */
+
+#include <net/sctp/sctp.h>
+#include <net/sctp/sm.h>
+
+/* Declare internal functions here. */
+static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn);
+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);
+
+static void sctp_mark_missing(struct sctp_outq *q,
+ struct list_head *transmitted_queue,
+ struct sctp_transport *transport,
+ __u32 highest_new_tsn,
+ int count_of_newacks);
+
+static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
+
+/* Add data to the front of the queue. */
+static inline void sctp_outq_head_data(struct sctp_outq *q,
+ struct sctp_chunk *ch)
+{
+ __skb_queue_head(&q->out, (struct sk_buff *)ch);
+ q->out_qlen += ch->skb->len;
+ return;
+}
+
+/* Take data from the front of the queue. */
+static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q)
+{
+ struct sctp_chunk *ch;
+ ch = (struct sctp_chunk *)__skb_dequeue(&q->out);
+ if (ch)
+ q->out_qlen -= ch->skb->len;
+ return ch;
+}
+/* Add data chunk to the end of the queue. */
+static inline void sctp_outq_tail_data(struct sctp_outq *q,
+ struct sctp_chunk *ch)
+{
+ __skb_queue_tail(&q->out, (struct sk_buff *)ch);
+ q->out_qlen += ch->skb->len;
+ return;
+}
+
+/*
+ * SFR-CACC algorithm:
+ * D) If count_of_newacks is greater than or equal to 2
+ * and t was not sent to the current primary then the
+ * sender MUST NOT increment missing report count for t.
+ */
+static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary,
+ struct sctp_transport *transport,
+ int count_of_newacks)
+{
+ if (count_of_newacks >=2 && transport != primary)
+ return 1;
+ return 0;
+}
+
+/*
+ * SFR-CACC algorithm:
+ * F) If count_of_newacks is less than 2, let d be the
+ * destination to which t was sent. If cacc_saw_newack
+ * is 0 for destination d, then the sender MUST NOT
+ * increment missing report count for t.
+ */
+static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport,
+ int count_of_newacks)
+{
+ if (count_of_newacks < 2 && !transport->cacc.cacc_saw_newack)
+ return 1;
+ return 0;
+}
+
+/*
+ * SFR-CACC algorithm:
+ * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD
+ * execute steps C, D, F.
+ *
+ * C has been implemented in sctp_outq_sack
+ */
+static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary,
+ struct sctp_transport *transport,
+ int count_of_newacks)
+{
+ if (!primary->cacc.cycling_changeover) {
+ if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks))
+ return 1;
+ if (sctp_cacc_skip_3_1_f(transport, count_of_newacks))
+ return 1;
+ return 0;
+ }
+ return 0;
+}
+
+/*
+ * SFR-CACC algorithm:
+ * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less
+ * than next_tsn_at_change of the current primary, then
+ * the sender MUST NOT increment missing report count
+ * for t.
+ */
+static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn)
+{
+ if (primary->cacc.cycling_changeover &&
+ TSN_lt(tsn, primary->cacc.next_tsn_at_change))
+ return 1;
+ return 0;
+}
+
+/*
+ * SFR-CACC algorithm:
+ * 3) If the missing report count for TSN t is to be
+ * incremented according to [RFC2960] and
+ * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set,
+ * then the sender MUST futher execute steps 3.1 and
+ * 3.2 to determine if the missing report count for
+ * TSN t SHOULD NOT be incremented.
+ *
+ * 3.3) If 3.1 and 3.2 do not dictate that the missing
+ * report count for t should not be incremented, then
+ * the sender SOULD increment missing report count for
+ * t (according to [RFC2960] and [SCTP_STEWART_2002]).
+ */
+static inline int sctp_cacc_skip(struct sctp_transport *primary,
+ struct sctp_transport *transport,
+ int count_of_newacks,
+ __u32 tsn)
+{
+ if (primary->cacc.changeover_active &&
+ (sctp_cacc_skip_3_1(primary, transport, count_of_newacks)
+ || sctp_cacc_skip_3_2(primary, tsn)))
+ return 1;
+ return 0;
+}
+
+/* Initialize an existing sctp_outq. This does the boring stuff.
+ * You still need to define handlers if you really want to DO
+ * something with this structure...
+ */
+void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q)
+{
+ q->asoc = asoc;
+ skb_queue_head_init(&q->out);
+ skb_queue_head_init(&q->control);
+ INIT_LIST_HEAD(&q->retransmit);
+ INIT_LIST_HEAD(&q->sacked);
+ INIT_LIST_HEAD(&q->abandoned);
+
+ q->outstanding_bytes = 0;
+ q->empty = 1;
+ q->cork = 0;
+
+ q->malloced = 0;
+ q->out_qlen = 0;
+}
+
+/* Free the outqueue structure and any related pending chunks.
+ */
+void sctp_outq_teardown(struct sctp_outq *q)
+{
+ struct sctp_transport *transport;
+ struct list_head *lchunk, *pos, *temp;
+ struct sctp_chunk *chunk;
+
+ /* Throw away unacknowledged chunks. */
+ list_for_each(pos, &q->asoc->peer.transport_addr_list) {
+ transport = list_entry(pos, struct sctp_transport, transports);
+ while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) {
+ chunk = list_entry(lchunk, struct sctp_chunk,
+ transmitted_list);
+ /* Mark as part of a failed message. */
+ sctp_chunk_fail(chunk, q->error);
+ sctp_chunk_free(chunk);
+ }
+ }
+
+ /* Throw away chunks that have been gap ACKed. */
+ list_for_each_safe(lchunk, temp, &q->sacked) {
+ list_del_init(lchunk);
+ chunk = list_entry(lchunk, struct sctp_chunk,
+ transmitted_list);
+ sctp_chunk_fail(chunk, q->error);
+ sctp_chunk_free(chunk);
+ }
+
+ /* Throw away any chunks in the retransmit queue. */
+ list_for_each_safe(lchunk, temp, &q->retransmit) {
+ list_del_init(lchunk);
+ chunk = list_entry(lchunk, struct sctp_chunk,
+ transmitted_list);
+ sctp_chunk_fail(chunk, q->error);
+ sctp_chunk_free(chunk);
+ }
+
+ /* Throw away any chunks that are in the abandoned queue. */
+ list_for_each_safe(lchunk, temp, &q->abandoned) {
+ list_del_init(lchunk);
+ chunk = list_entry(lchunk, struct sctp_chunk,
+ transmitted_list);
+ sctp_chunk_fail(chunk, q->error);
+ sctp_chunk_free(chunk);
+ }
+
+ /* Throw away any leftover data chunks. */
+ while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
+
+ /* Mark as send failure. */
+ sctp_chunk_fail(chunk, q->error);
+ sctp_chunk_free(chunk);
+ }
+
+ q->error = 0;
+
+ /* Throw away any leftover control chunks. */
+ while ((chunk = (struct sctp_chunk *) skb_dequeue(&q->control)) != NULL)
+ sctp_chunk_free(chunk);
+}
+
+/* Free the outqueue structure and any related pending chunks. */
+void sctp_outq_free(struct sctp_outq *q)
+{
+ /* Throw away leftover chunks. */
+ sctp_outq_teardown(q);
+
+ /* If we were kmalloc()'d, free the memory. */
+ if (q->malloced)
+ kfree(q);
+}
+
+/* Put a new chunk in an sctp_outq. */
+int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk)
+{
+ int error = 0;
+
+ SCTP_DEBUG_PRINTK("sctp_outq_tail(%p, %p[%s])\n",
+ q, chunk, chunk && chunk->chunk_hdr ?
+ sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
+ : "Illegal Chunk");
+
+ /* If it is data, queue it up, otherwise, send it
+ * immediately.
+ */
+ if (SCTP_CID_DATA == chunk->chunk_hdr->type) {
+ /* Is it OK to queue data chunks? */
+ /* From 9. Termination of Association
+ *
+ * When either endpoint performs a shutdown, the
+ * association on each peer will stop accepting new
+ * data from its user and only deliver data in queue
+ * at the time of sending or receiving the SHUTDOWN
+ * chunk.
+ */
+ switch (q->asoc->state) {
+ case SCTP_STATE_EMPTY:
+ case SCTP_STATE_CLOSED:
+ case SCTP_STATE_SHUTDOWN_PENDING:
+ case SCTP_STATE_SHUTDOWN_SENT:
+ case SCTP_STATE_SHUTDOWN_RECEIVED:
+ case SCTP_STATE_SHUTDOWN_ACK_SENT:
+ /* Cannot send after transport endpoint shutdown */
+ error = -ESHUTDOWN;
+ break;
+
+ default:
+ SCTP_DEBUG_PRINTK("outqueueing (%p, %p[%s])\n",
+ q, chunk, chunk && chunk->chunk_hdr ?
+ sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
+ : "Illegal Chunk");
+
+ sctp_outq_tail_data(q, chunk);
+ if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
+ SCTP_INC_STATS(SCTP_MIB_OUTUNORDERCHUNKS);
+ else
+ SCTP_INC_STATS(SCTP_MIB_OUTORDERCHUNKS);
+ q->empty = 0;
+ break;
+ };
+ } else {
+ __skb_queue_tail(&q->control, (struct sk_buff *) chunk);
+ SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
+ }
+
+ if (error < 0)
+ return error;
+
+ if (!q->cork)
+ error = sctp_outq_flush(q, 0);
+
+ return error;
+}
+
+/* Insert a chunk into the sorted list based on the TSNs. The retransmit list
+ * and the abandoned list are in ascending order.
+ */
+static void sctp_insert_list(struct list_head *head, struct list_head *new)
+{
+ struct list_head *pos;
+ struct sctp_chunk *nchunk, *lchunk;
+ __u32 ntsn, ltsn;
+ int done = 0;
+
+ nchunk = list_entry(new, struct sctp_chunk, transmitted_list);
+ ntsn = ntohl(nchunk->subh.data_hdr->tsn);
+
+ list_for_each(pos, head) {
+ lchunk = list_entry(pos, struct sctp_chunk, transmitted_list);
+ ltsn = ntohl(lchunk->subh.data_hdr->tsn);
+ if (TSN_lt(ntsn, ltsn)) {
+ list_add(new, pos->prev);
+ done = 1;
+ break;
+ }
+ }
+ if (!done)
+ list_add_tail(new, head);
+}
+
+/* Mark all the eligible packets on a transport for retransmission. */
+void sctp_retransmit_mark(struct sctp_outq *q,
+ struct sctp_transport *transport,
+ __u8 fast_retransmit)
+{
+ struct list_head *lchunk, *ltemp;
+ struct sctp_chunk *chunk;
+
+ /* Walk through the specified transmitted queue. */
+ list_for_each_safe(lchunk, ltemp, &transport->transmitted) {
+ chunk = list_entry(lchunk, struct sctp_chunk,
+ transmitted_list);
+
+ /* If the chunk is abandoned, move it to abandoned list. */
+ if (sctp_chunk_abandoned(chunk)) {
+ list_del_init(lchunk);
+ sctp_insert_list(&q->abandoned, lchunk);
+ continue;
+ }
+
+ /* If we are doing retransmission due to a fast retransmit,
+ * only the chunk's that are marked for fast retransmit
+ * should be added to the retransmit queue. If we are doing
+ * retransmission due to a timeout or pmtu discovery, only the
+ * chunks that are not yet acked should be added to the
+ * retransmit queue.
+ */
+ if ((fast_retransmit && chunk->fast_retransmit) ||
+ (!fast_retransmit && !chunk->tsn_gap_acked)) {
+ /* RFC 2960 6.2.1 Processing a Received SACK
+ *
+ * C) Any time a DATA chunk is marked for
+ * retransmission (via either T3-rtx timer expiration
+ * (Section 6.3.3) or via fast retransmit
+ * (Section 7.2.4)), add the data size of those
+ * chunks to the rwnd.
+ */
+ q->asoc->peer.rwnd += sctp_data_size(chunk);
+ q->outstanding_bytes -= sctp_data_size(chunk);
+ transport->flight_size -= sctp_data_size(chunk);
+
+ /* sctpimpguide-05 Section 2.8.2
+ * M5) If a T3-rtx timer expires, the
+ * 'TSN.Missing.Report' of all affected TSNs is set
+ * to 0.
+ */
+ chunk->tsn_missing_report = 0;
+
+ /* If a chunk that is being used for RTT measurement
+ * has to be retransmitted, we cannot use this chunk
+ * anymore for RTT measurements. Reset rto_pending so
+ * that a new RTT measurement is started when a new
+ * data chunk is sent.
+ */
+ if (chunk->rtt_in_progress) {
+ chunk->rtt_in_progress = 0;
+ transport->rto_pending = 0;
+ }
+
+ /* Move the chunk to the retransmit queue. The chunks
+ * on the retransmit queue are always kept in order.
+ */
+ list_del_init(lchunk);
+ sctp_insert_list(&q->retransmit, lchunk);
+ }
+ }
+
+ SCTP_DEBUG_PRINTK("%s: transport: %p, fast_retransmit: %d, "
+ "cwnd: %d, ssthresh: %d, flight_size: %d, "
+ "pba: %d\n", __FUNCTION__,
+ transport, fast_retransmit,
+ transport->cwnd, transport->ssthresh,
+ transport->flight_size,
+ transport->partial_bytes_acked);
+
+}
+
+/* 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;
+ __u8 fast_retransmit = 0;
+
+ switch(reason) {
+ case SCTP_RTXR_T3_RTX:
+ 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);
+ break;
+ case SCTP_RTXR_FAST_RTX:
+ sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX);
+ fast_retransmit = 1;
+ break;
+ case SCTP_RTXR_PMTUD:
+ default:
+ break;
+ }
+
+ sctp_retransmit_mark(q, transport, fast_retransmit);
+
+ /* 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.
+ */
+ sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point);
+
+ 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 list_head *lchunk, *lchunk1;
+ struct sctp_transport *transport = pkt->transport;
+ sctp_xmit_t status;
+ struct sctp_chunk *chunk, *chunk1;
+ struct sctp_association *asoc;
+ int error = 0;
+
+ asoc = q->asoc;
+ lqueue = &q->retransmit;
+
+ /* 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.]
+ */
+ lchunk = sctp_list_dequeue(lqueue);
+
+ while (lchunk) {
+ chunk = list_entry(lchunk, struct sctp_chunk,
+ transmitted_list);
+
+ /* 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_add_tail(lchunk, &transport->transmitted);
+ lchunk = sctp_list_dequeue(lqueue);
+ continue;
+ }
+
+ /* Attempt to append this chunk to the packet. */
+ status = sctp_packet_append_chunk(pkt, chunk);
+
+ switch (status) {
+ case SCTP_XMIT_PMTU_FULL:
+ /* Send this packet. */
+ if ((error = sctp_packet_transmit(pkt)) == 0)
+ *start_timer = 1;
+
+ /* If we are retransmitting, we should only
+ * send a single packet.
+ */
+ if (rtx_timeout) {
+ list_add(lchunk, lqueue);
+ lchunk = NULL;
+ }
+
+ /* Bundle lchunk in the next round. */
+ break;
+
+ case SCTP_XMIT_RWND_FULL:
+ /* Send this packet. */
+ if ((error = sctp_packet_transmit(pkt)) == 0)
+ *start_timer = 1;
+
+ /* Stop sending DATA as there is no more room
+ * at the receiver.
+ */
+ list_add(lchunk, lqueue);
+ lchunk = NULL;
+ break;
+
+ case SCTP_XMIT_NAGLE_DELAY:
+ /* Send this packet. */
+ if ((error = sctp_packet_transmit(pkt)) == 0)
+ *start_timer = 1;
+
+ /* Stop sending DATA because of nagle delay. */
+ list_add(lchunk, lqueue);
+ lchunk = NULL;
+ break;
+
+ default:
+ /* The append was successful, so add this chunk to
+ * the transmitted list.
+ */
+ list_add_tail(lchunk, &transport->transmitted);
+
+ /* Mark the chunk as ineligible for fast retransmit
+ * after it is retransmitted.
+ */
+ chunk->fast_retransmit = 0;
+
+ *start_timer = 1;
+ q->empty = 0;
+
+ /* Retrieve a new chunk to bundle. */
+ lchunk = sctp_list_dequeue(lqueue);
+ 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 && !lchunk) {
+ list_for_each(lchunk1, lqueue) {
+ chunk1 = list_entry(lchunk1, struct sctp_chunk,
+ transmitted_list);
+ chunk1->fast_retransmit = 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.
+ */
+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 sk_buff_head *queue;
+ struct sctp_transport *transport = NULL;
+ struct sctp_transport *new_transport;
+ struct sctp_chunk *chunk;
+ sctp_xmit_t status;
+ int error = 0;
+ int start_timer = 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.
+ * ...
+ */
+
+ queue = &q->control;
+ while ((chunk = (struct sctp_chunk *)skb_dequeue(queue)) != NULL) {
+ /* Pick the right transport to use. */
+ new_transport = chunk->transport;
+
+ if (!new_transport) {
+ new_transport = asoc->peer.active_path;
+ } else if (!new_transport->active) {
+ /* 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.
+ * ...
+ */
+ if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT &&
+ chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_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:
+ case SCTP_CID_SACK:
+ case SCTP_CID_HEARTBEAT:
+ case SCTP_CID_HEARTBEAT_ACK:
+ case SCTP_CID_SHUTDOWN:
+ case SCTP_CID_SHUTDOWN_ACK:
+ case SCTP_CID_ERROR:
+ case SCTP_CID_COOKIE_ECHO:
+ case SCTP_CID_COOKIE_ACK:
+ case SCTP_CID_ECN_ECNE:
+ case SCTP_CID_ECN_CWR:
+ case SCTP_CID_ASCONF:
+ case SCTP_CID_ASCONF_ACK:
+ case SCTP_CID_FWD_TSN:
+ sctp_packet_transmit_chunk(packet, chunk);
+ break;
+
+ default:
+ /* We built a chunk with an illegal type! */
+ BUG();
+ };
+ }
+
+ /* 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 (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;
+ }
+
+ /* Finally, transmit new packets. */
+ start_timer = 0;
+ queue = &q->out;
+
+ 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->active)
+ new_transport = asoc->peer.active_path;
+
+ /* 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);
+ }
+
+ 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);
+
+ 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:
+ 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);
+ }
+
+ 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;
+}
+
+/* Return the highest new tsn that is acknowledged by the given SACK chunk. */
+static __u32 sctp_highest_new_tsn(struct sctp_sackhdr *sack,
+ struct sctp_association *asoc)
+{
+ struct list_head *ltransport, *lchunk;
+ struct sctp_transport *transport;
+ struct sctp_chunk *chunk;
+ __u32 highest_new_tsn, tsn;
+ struct list_head *transport_list = &asoc->peer.transport_addr_list;
+
+ highest_new_tsn = ntohl(sack->cum_tsn_ack);
+
+ list_for_each(ltransport, transport_list) {
+ transport = list_entry(ltransport, struct sctp_transport,
+ transports);
+ list_for_each(lchunk, &transport->transmitted) {
+ chunk = list_entry(lchunk, struct sctp_chunk,
+ transmitted_list);
+ tsn = ntohl(chunk->subh.data_hdr->tsn);
+
+ if (!chunk->tsn_gap_acked &&
+ TSN_lt(highest_new_tsn, tsn) &&
+ sctp_acked(sack, tsn))
+ highest_new_tsn = tsn;
+ }
+ }
+
+ return highest_new_tsn;
+}
+
+/* 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, *pos, *temp;
+ sctp_sack_variable_t *frags = sack->variable;
+ __u32 sack_ctsn, ctsn, tsn;
+ __u32 highest_tsn, highest_new_tsn;
+ __u32 sack_a_rwnd;
+ unsigned outstanding;
+ struct sctp_transport *primary = asoc->peer.primary_path;
+ int count_of_newacks = 0;
+
+ /* Grab the association's destination address list. */
+ transport_list = &asoc->peer.transport_addr_list;
+
+ sack_ctsn = ntohl(sack->cum_tsn_ack);
+
+ /*
+ * 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.
+ */
+ if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) {
+ primary->cacc.changeover_active = 0;
+ list_for_each(pos, transport_list) {
+ transport = list_entry(pos, struct sctp_transport,
+ transports);
+ transport->cacc.cycling_changeover = 0;
+ }
+ }
+
+ /*
+ * 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 actions:
+ *
+ * A) Initialize the cacc_saw_newack to 0 for all destination
+ * addresses.
+ */
+ if (sack->num_gap_ack_blocks > 0 &&
+ primary->cacc.changeover_active) {
+ list_for_each(pos, transport_list) {
+ transport = list_entry(pos, struct sctp_transport,
+ transports);
+ transport->cacc.cacc_saw_newack = 0;
+ }
+ }
+
+ /* Get the highest TSN in the sack. */
+ highest_tsn = sack_ctsn;
+ if (sack->num_gap_ack_blocks)
+ highest_tsn +=
+ ntohs(frags[ntohs(sack->num_gap_ack_blocks) - 1].gab.end);
+
+ if (TSN_lt(asoc->highest_sacked, highest_tsn)) {
+ highest_new_tsn = highest_tsn;
+ asoc->highest_sacked = highest_tsn;
+ } else {
+ highest_new_tsn = sctp_highest_new_tsn(sack, asoc);
+ }
+
+ /* 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);
+ sctp_mark_missing(q, &q->retransmit, NULL, highest_new_tsn, 0);
+
+ /* 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(pos, transport_list) {
+ transport = list_entry(pos, struct sctp_transport,
+ 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 ++;
+ }
+
+ list_for_each(pos, transport_list) {
+ transport = list_entry(pos, struct sctp_transport,
+ transports);
+ sctp_mark_missing(q, &transport->transmitted, transport,
+ highest_new_tsn, 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;
+
+ /* 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))
+ 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",
+ __FUNCTION__, sack_ctsn);
+ SCTP_DEBUG_PRINTK("%s: Cumulative TSN Ack of association, "
+ "%p is 0x%x. Adv peer ack point: 0x%x\n",
+ __FUNCTION__, 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 = skb_queue_empty(&q->out) && skb_queue_empty(&q->control) &&
+ list_empty(&q->retransmit);
+ if (!q->empty)
+ goto finish;
+
+ list_for_each(pos, transport_list) {
+ transport = list_entry(pos, struct sctp_transport,
+ 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;
+
+ /* 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);
+ 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->resent &&
+ tchunk->rtt_in_progress) {
+ rtt = jiffies - tchunk->sent_at;
+ sctp_transport_update_rto(transport,
+ rtt);
+ }
+ }
+ 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) {
+ tchunk->tsn_gap_acked = 1;
+ bytes_acked += sctp_data_size(tchunk);
+ /*
+ * 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'.
+ */
+ if (!tchunk->tsn_gap_acked) {
+ tchunk->tsn_gap_acked = 1;
+ bytes_acked += sctp_data_size(tchunk);
+ }
+ 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("-%08x",
+ dbg_last_ack_tsn);
+ }
+
+ /* Start a new range. */
+ SCTP_DEBUG_PRINTK(",%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("-%08x",
+ dbg_last_kept_tsn);
+ }
+
+ SCTP_DEBUG_PRINTK("\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",
+ __FUNCTION__,
+ tsn);
+ tchunk->tsn_gap_acked = 0;
+
+ 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("-%08x",
+ dbg_last_kept_tsn);
+
+ SCTP_DEBUG_PRINTK(",%08x", tsn);
+ dbg_kept_tsn = tsn;
+ break;
+
+ case 0:
+ if (dbg_last_ack_tsn != dbg_ack_tsn)
+ SCTP_DEBUG_PRINTK("-%08x",
+ dbg_last_ack_tsn);
+ SCTP_DEBUG_PRINTK("\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("-%08x\n", dbg_last_ack_tsn);
+ } else {
+ SCTP_DEBUG_PRINTK("\n");
+ }
+ break;
+
+ case 1:
+ if (dbg_last_kept_tsn != dbg_kept_tsn) {
+ SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_kept_tsn);
+ } else {
+ SCTP_DEBUG_PRINTK("\n");
+ }
+ };
+#endif /* SCTP_DEBUG */
+ if (transport) {
+ if (bytes_acked) {
+ /* 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;
+
+ /* Mark the destination transport address as
+ * active if it is not so marked.
+ */
+ if (!transport->active) {
+ 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;
+ q->outstanding_bytes -= bytes_acked;
+ } 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.
+ */
+ if (!q->asoc->peer.rwnd &&
+ !list_empty(&tlist) &&
+ (sack_ctsn+2 == q->asoc->next_tsn)) {
+ SCTP_DEBUG_PRINTK("%s: SACK received for zero "
+ "window probe: %u\n",
+ __FUNCTION__, 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;
+ struct list_head *pos;
+ __u32 tsn;
+ char do_fast_retransmit = 0;
+ struct sctp_transport *primary = q->asoc->peer.primary_path;
+
+ list_for_each(pos, transmitted_queue) {
+
+ chunk = list_entry(pos, struct sctp_chunk, 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 &&
+ !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, transport,
+ count_of_newacks, tsn)) {
+ chunk->tsn_missing_report++;
+
+ SCTP_DEBUG_PRINTK(
+ "%s: TSN 0x%x missing counter: %d\n",
+ __FUNCTION__, tsn,
+ chunk->tsn_missing_report);
+ }
+ }
+ /*
+ * M4) If any DATA chunk is found to have a
+ * 'TSN.Missing.Report'
+ * value larger than or equal to 4, mark that chunk for
+ * retransmission and start the fast retransmit procedure.
+ */
+
+ if (chunk->tsn_missing_report >= 4) {
+ chunk->fast_retransmit = 1;
+ 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",
+ __FUNCTION__, 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, __u16 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;
+
+ /* 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);
+ if (!chunk->tsn_gap_acked) {
+ chunk->transport->flight_size -=
+ sctp_data_size(chunk);
+ q->outstanding_bytes -= sctp_data_size(chunk);
+ }
+ 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) {
+ __skb_queue_tail(&q->control, (struct sk_buff *)ftsn_chunk);
+ SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
+ }
+}
