[PATCH 1/2] [TCP]: Add highest_sack seqno, points to globally highest SACK
From: Ilpo Järvinen <hidden>
Date: 2007-03-07 17:50:21
Subsystem:
networking [general], networking [tcp], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Neal Cardwell, Linus Torvalds
It is maintained only in during slowpath of tcp_ack(). 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: Ilpo Järvinen <redacted> --- include/linux/tcp.h | 2 ++ net/ipv4/tcp_input.c | 10 ++++++++++ net/ipv4/tcp_minisocks.c | 1 + 3 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index b73687a..807fc96 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h@@ -320,6 +320,8 @@ #endif 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;
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 22d0bb0..827171a 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c@@ -1188,6 +1188,10 @@ tcp_sacktag_write_queue(struct sock *sk, 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);
@@ -2762,10 +2766,16 @@ static int tcp_ack(struct sock *sk, stru else NET_INC_STATS_BH(LINUX_MIB_TCPPUREACKS); + /* Transition from fast to slow path, is this correct way? */ + if (tp->pred_flags) + tp->highest_sack = tp->snd_una; + flag |= tcp_ack_update_window(sk, tp, skb, ack, ack_seq); if (TCP_SKB_CB(skb)->sacked) flag |= tcp_sacktag_write_queue(sk, skb, prior_snd_una); + else if (before(tp->highest_sack, tp->snd_una)) + tp->highest_sack = tp->snd_una; if (TCP_ECN_rcv_ecn_echo(tp, skb->h.th)) flag |= FLAG_ECE;
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 0a57c36..68d0000 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c@@ -389,6 +389,7 @@ struct sock *tcp_create_openreq_child(st newtp->pred_flags = 0; newtp->rcv_wup = newtp->copied_seq = newtp->rcv_nxt = treq->rcv_isn + 1; newtp->snd_sml = newtp->snd_una = newtp->snd_nxt = treq->snt_isn + 1; + newtp->highest_sack = treq->snt_isn + 1; tcp_prequeue_init(newtp);
--
1.4.2