From 8a3c3a972741dec77220a19642bd3331551ad2d9 Mon Sep 17 00:00:00 2001 From: Baruch Even Date: Sun, 4 Feb 2007 23:37:41 -0800 Subject: [PATCH] [TCP]: Check num sacks in SACK fast path We clear the unused parts of the SACK cache, This prevents us from mistakenly taking the cache data if the old data in the SACK cache is the same as the data in the SACK block. This assumes that we never receive an empty SACK block with start and end both at zero. Signed-off-by: Baruch Even Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 870f53afd363..c6109895bb5e 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -998,6 +998,11 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ tp->recv_sack_cache[i].start_seq = start_seq; tp->recv_sack_cache[i].end_seq = end_seq; } + /* Clear the rest of the cache sack blocks so they won't match mistakenly. */ + for (; i < ARRAY_SIZE(tp->recv_sack_cache); i++) { + tp->recv_sack_cache[i].start_seq = 0; + tp->recv_sack_cache[i].end_seq = 0; + } first_sack_index = 0; if (flag) -- 2.20.1