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Commit d738cd8f authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by David S. Miller
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[TCP]: Add highest_sack seqno, points to globally highest SACK 



It is guaranteed to be valid only when !tp->sacked_out. In most
cases this seqno is available in the last ACK but there is no
guarantee for that. The new fast recovery loss marking algorithm
needs this as entry point.

Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d961db35

include/linux/tcp.h

+2 −0
Original line number Diff line number Diff line
@@ -333,6 +333,8 @@ struct tcp_sock { 


	struct tcp_sack_block_wire recv_sack_cache[4];



	u32	highest_sack;	/* Start seq of globally highest revd SACK (valid only in slowpath) */



	/* from STCP, retrans queue hinting */

	struct sk_buff* lost_skb_hint;

net/ipv4/tcp_input.c

+7 −1
Original line number Diff line number Diff line
@@ -979,8 +979,10 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ 
	int i;

	int first_sack_index;



	if (!tp->sacked_out)

	if (!tp->sacked_out) {

		tp->fackets_out = 0;

		tp->highest_sack = tp->snd_una;

	}

	prior_fackets = tp->fackets_out;



	/* Check for D-SACK. */
@@ -1217,6 +1219,10 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ 


				if (fack_count > tp->fackets_out)

					tp->fackets_out = fack_count;



				if (after(TCP_SKB_CB(skb)->seq,

				    tp->highest_sack))

					tp->highest_sack = TCP_SKB_CB(skb)->seq;

			} else {

				if (dup_sack && (sacked&TCPCB_RETRANS))

					reord = min(fack_count, reord);