Though not very efficient, the previous way of maintaining a
stale SACK cache past reneging protected better against misuse
because receiver couldn't cause set-clear ping-pong for
SACKED_ACKED for a large number of skbs.
Mostly copy-paste from sacktag clearer. Compile tested.
Signed-off-by: Ilpo Järvinen <[EMAIL PROTECTED]>
---
net/ipv4/tcp_input.c | 11 +++++++++--
1 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 97b9be2..ea196de 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1509,7 +1509,7 @@ void tcp_enter_loss(struct sock *sk, int
const struct inet_connection_sock *icsk = inet_csk(sk);
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb;
- int cnt = 0;
+ int cnt = 0, i;
/* Reduce ssthresh if it has not yet been made inside this window. */
if (icsk->icsk_ca_state <= TCP_CA_Disorder || tp->snd_una ==
tp->high_seq ||
@@ -1527,8 +1527,15 @@ void tcp_enter_loss(struct sock *sk, int
/* Push undo marker, if it was plain RTO and nothing
* was retransmitted. */
- if (!how)
+ if (!how) {
tp->undo_marker = tp->snd_una;
+ } else {
+ /* We're going to flush SACKed state, every SACK counts again */
+ for (i = 0; i < ARRAY_SIZE(tp->recv_sack_cache); i++) {
+ tp->recv_sack_cache[i].start_seq = 0;
+ tp->recv_sack_cache[i].end_seq = 0;
+ }
+ }
tcp_for_write_queue(skb, sk) {
if (skb == tcp_send_head(sk))
--
1.4.2
