From 1aba721eba1d84a2defce45b950272cee1e6c72a Mon Sep 17 00:00:00 2001 From: Gilad Ben-Yossef Date: Wed, 28 Oct 2009 04:15:24 +0000 Subject: Add the no SACK route option feature Implement querying and acting upon the no sack bit in the features field. Signed-off-by: Gilad Ben-Yossef Sigend-off-by: Ori Finkelman Sigend-off-by: Yony Amit Signed-off-by: David S. Miller --- net/ipv4/tcp_output.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'net/ipv4/tcp_output.c') diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 2e2eb74ac4c..b35802af3c4 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -464,6 +464,7 @@ static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb, struct tcp_md5sig_key **md5) { struct tcp_sock *tp = tcp_sk(sk); unsigned size = 0; + struct dst_entry *dst = __sk_dst_get(sk); #ifdef CONFIG_TCP_MD5SIG *md5 = tp->af_specific->md5_lookup(sk, sk); @@ -498,7 +499,8 @@ static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb, opts->options |= OPTION_WSCALE; size += TCPOLEN_WSCALE_ALIGNED; } - if (likely(sysctl_tcp_sack)) { + if (likely(sysctl_tcp_sack && + !dst_feature(dst, RTAX_FEATURE_NO_SACK))) { opts->options |= OPTION_SACK_ADVERTISE; if (unlikely(!(OPTION_TS & opts->options))) size += TCPOLEN_SACKPERM_ALIGNED; -- cgit v1.2.3