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Commit 62aeaff5 authored by Vlad Yasevich's avatar Vlad Yasevich Committed by David S. Miller
Browse files

sctp: Start T3-RTX timer when fast retransmitting lowest TSN 



When we are trying to fast retransmit the lowest outstanding TSN, we
need to restart the T3-RTX timer, so that subsequent timeouts will
correctly tag all the packets necessary for retransmissions.

Signed-off-by: default avatarVlad Yasevich <vladislav.yasevich@hp.com>
Tested-by: default avatarWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a6465234

include/net/sctp/structs.h

+4 −1
Original line number Diff line number Diff line
@@ -1051,7 +1051,7 @@ void sctp_transport_route(struct sctp_transport *, union sctp_addr *, 
			  struct sctp_sock *);

void sctp_transport_pmtu(struct sctp_transport *);

void sctp_transport_free(struct sctp_transport *);

void sctp_transport_reset_timers(struct sctp_transport *);

void sctp_transport_reset_timers(struct sctp_transport *, int);

void sctp_transport_hold(struct sctp_transport *);

void sctp_transport_put(struct sctp_transport *);

void sctp_transport_update_rto(struct sctp_transport *, __u32);
@@ -1141,6 +1141,9 @@ struct sctp_outq { 
	/* How many unackd bytes do we have in-flight?	*/

	__u32 outstanding_bytes;



	/* Are we doing fast-rtx on this queue */

	char fast_rtx;



	/* Corked? */

	char cork;

net/sctp/outqueue.c

+31 −11
Original line number Diff line number Diff line
@@ -208,6 +208,7 @@ void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q) 
	INIT_LIST_HEAD(&q->sacked);

	INIT_LIST_HEAD(&q->abandoned);



	q->fast_rtx = 0;

	q->outstanding_bytes = 0;

	q->empty = 1;

	q->cork  = 0;
@@ -500,6 +501,7 @@ void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport, 
	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);
@@ -543,10 +545,13 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, 
	sctp_xmit_t status;

	struct sctp_chunk *chunk, *chunk1;

	struct sctp_association *asoc;

	int fast_rtx;

	int error = 0;

	int timer = 0;



	asoc = q->asoc;

	lqueue = &q->retransmit;

	fast_rtx = q->fast_rtx;



	/* RFC 2960 6.3.3 Handle T3-rtx Expiration

	 *
@@ -587,13 +592,12 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, 
		switch (status) {

		case SCTP_XMIT_PMTU_FULL:

			/* Send this packet.  */

			if ((error = sctp_packet_transmit(pkt)) == 0)

				*start_timer = 1;

			error = sctp_packet_transmit(pkt);



			/* If we are retransmitting, we should only

			 * send a single packet.

			 */

			if (rtx_timeout) {

			if (rtx_timeout || fast_rtx) {

				list_add(lchunk, lqueue);

				lchunk = NULL;

			}
@@ -603,8 +607,7 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, 


		case SCTP_XMIT_RWND_FULL:

			/* Send this packet. */

			if ((error = sctp_packet_transmit(pkt)) == 0)

				*start_timer = 1;

			error = sctp_packet_transmit(pkt);



			/* Stop sending DATA as there is no more room

			 * at the receiver.
@@ -615,8 +618,7 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, 


		case SCTP_XMIT_NAGLE_DELAY:

			/* Send this packet. */

			if ((error = sctp_packet_transmit(pkt)) == 0)

				*start_timer = 1;

			error = sctp_packet_transmit(pkt);



			/* Stop sending DATA because of nagle delay. */

			list_add(lchunk, lqueue);
@@ -635,7 +637,14 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, 
			if (chunk->fast_retransmit > 0)

				chunk->fast_retransmit = -1;



			*start_timer = 1;

			/* Force start T3-rtx timer when fast retransmitting

			 * the earliest outstanding TSN

			 */

			if (!timer && fast_rtx &&

			    ntohl(chunk->subh.data_hdr->tsn) ==

					     asoc->ctsn_ack_point + 1)

				timer = 2;



			q->empty = 0;



			/* Retrieve a new chunk to bundle. */
@@ -643,12 +652,16 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, 
			break;

		}



		/* Set the timer if there were no errors */

		if (!error && !timer)

			timer = 1;



		/* 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) {

		if (rtx_timeout && fast_rtx) {

			list_for_each_entry(chunk1, lqueue, transmitted_list) {

				if (chunk1->fast_retransmit > 0)

					chunk1->fast_retransmit = -1;
@@ -656,6 +669,12 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, 
		}

	}



	*start_timer = timer;



	/* Clear fast retransmit hint */

	if (fast_rtx)

		q->fast_rtx = 0;



	return error;

}
@@ -862,7 +881,8 @@ int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) 
						    rtx_timeout, &start_timer);



			if (start_timer)

				sctp_transport_reset_timers(transport);

				sctp_transport_reset_timers(transport,

							    start_timer-1);



			/* This can happen on COOKIE-ECHO resend.  Only

			 * one chunk can get bundled with a COOKIE-ECHO.
@@ -977,7 +997,7 @@ int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) 
			list_add_tail(&chunk->transmitted_list,

				      &transport->transmitted);



			sctp_transport_reset_timers(transport);

			sctp_transport_reset_timers(transport, start_timer-1);



			q->empty = 0;

net/sctp/transport.c

+2 −2
Original line number Diff line number Diff line
@@ -191,7 +191,7 @@ static void sctp_transport_destroy(struct sctp_transport *transport) 
/* Start T3_rtx timer if it is not already running and update the heartbeat

 * timer.  This routine is called every time a DATA chunk is sent.

 */

void sctp_transport_reset_timers(struct sctp_transport *transport)

void sctp_transport_reset_timers(struct sctp_transport *transport, int force)

{

	/* RFC 2960 6.3.2 Retransmission Timer Rules

	 *
@@ -201,7 +201,7 @@ void sctp_transport_reset_timers(struct sctp_transport *transport) 
	 * address.

	 */



	if (!timer_pending(&transport->T3_rtx_timer))

	if (force || !timer_pending(&transport->T3_rtx_timer))

		if (!mod_timer(&transport->T3_rtx_timer,

			       jiffies + transport->rto))

			sctp_transport_hold(transport);