This patch allows to process only newly reported SACK blocks at the
sender side. An ACK packet contains up to three SACK blocks, and some
of them may be already reported and processed blocks. This patch
prevents processing of such already processed SACK blocks.
Signed-off-by: Ryousei Takano <[EMAIL PROTECTED]>
Signed-off-by: Yuetsu Kodama <[EMAIL PROTECTED]>
---
net/ipv4/tcp_input.c | 24 ++++++++++++++++++++++++
1 files changed, 24 insertions(+), 0 deletions(-)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index bbad2cd..9615fc9 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -978,6 +978,7 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff
*ack_skb, u32 prior_snd_
int cached_fack_count;
int i;
int first_sack_index;
+ u8 sack_block_skip[4] = {0,0,0,0};
if (!tp->sacked_out)
tp->fackets_out = 0;
@@ -1012,6 +1013,21 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff
*ack_skb, u32 prior_snd_
if (before(TCP_SKB_CB(ack_skb)->ack_seq, prior_snd_una -
tp->max_window))
return 0;
+ /* Skip processing cached SACK blocks. */
+ for (i = 0; i < num_sacks; i++) {
+ __be32 start_seq = sp[i].start_seq;
+ __be32 end_seq = sp[i].end_seq;
+ int j;
+
+ for (j = 0; j < ARRAY_SIZE(tp->recv_sack_cache); j++) {
+ if ((tp->recv_sack_cache[j].start_seq == start_seq) &&
+ (tp->recv_sack_cache[j].end_seq == end_seq)) {
+ sack_block_skip[i] = 1;
+ break;
+ }
+ }
+ }
+
/* SACK fastpath:
* if the only SACK change is the increase of the end_seq of
* the first block then only apply that SACK block
@@ -1051,11 +1067,16 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff
*ack_skb, u32 prior_snd_
if (after(ntohl(sp[j].start_seq),
ntohl(sp[j+1].start_seq))){
struct tcp_sack_block_wire tmp;
+ u8 sbtmp;
tmp = sp[j];
sp[j] = sp[j+1];
sp[j+1] = tmp;
+ sbtmp = sack_block_skip[j];
+ sack_block_skip[j] =
sack_block_skip[j+1];
+ sack_block_skip[j+1] = sbtmp;
+
/* Track where the first SACK block
goes to */
if (j == first_sack_index)
first_sack_index = j+1;
@@ -1083,6 +1104,9 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff
*ack_skb, u32 prior_snd_
int fack_count;
int dup_sack = (found_dup_sack && (i == first_sack_index));
+ if (sack_block_skip[i])
+ continue;
+
skb = cached_skb;
fack_count = cached_fack_count;
--
1.5.2.4
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
