From dc343475ed062e13fc260acccaab91d7d80fd5b2 Mon Sep 17 00:00:00 2001 From: Gilad Ben-Yossef Date: Wed, 28 Oct 2009 04:15:27 +0000 Subject: [PATCH] Allow disabling of DSACK TCP option per route Add and use no DSCAK 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 --- include/linux/rtnetlink.h | 1 + net/ipv4/tcp_input.c | 8 ++++++-- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h index 6784b342cbb..e78b60cd65a 100644 --- a/include/linux/rtnetlink.h +++ b/include/linux/rtnetlink.h @@ -381,6 +381,7 @@ enum #define RTAX_FEATURE_NO_TSTAMP 0x00000004 #define RTAX_FEATURE_ALLFRAG 0x00000008 #define RTAX_FEATURE_NO_WSCALE 0x00000010 +#define RTAX_FEATURE_NO_DSACK 0x00000020 struct rta_session { diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 393c56921dc..ba0eab65fe8 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4080,8 +4080,10 @@ static inline int tcp_sack_extend(struct tcp_sack_block *sp, u32 seq, static void tcp_dsack_set(struct sock *sk, u32 seq, u32 end_seq) { struct tcp_sock *tp = tcp_sk(sk); + struct dst_entry *dst = __sk_dst_get(sk); - if (tcp_is_sack(tp) && sysctl_tcp_dsack) { + if (tcp_is_sack(tp) && sysctl_tcp_dsack && + !dst_feature(dst, RTAX_FEATURE_NO_DSACK)) { int mib_idx; if (before(seq, tp->rcv_nxt)) @@ -4110,13 +4112,15 @@ static void tcp_dsack_extend(struct sock *sk, u32 seq, u32 end_seq) static void tcp_send_dupack(struct sock *sk, struct sk_buff *skb) { struct tcp_sock *tp = tcp_sk(sk); + struct dst_entry *dst = __sk_dst_get(sk); if (TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq && before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) { NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_DELAYEDACKLOST); tcp_enter_quickack_mode(sk); - if (tcp_is_sack(tp) && sysctl_tcp_dsack) { + if (tcp_is_sack(tp) && sysctl_tcp_dsack && + !dst_feature(dst, RTAX_FEATURE_NO_DSACK)) { u32 end_seq = TCP_SKB_CB(skb)->end_seq; if (after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt))