Subject: [PATCH 5/6] tcp: Report mss_clamp with TCP_MAXSEG option in repair mode

From: Pavel Emelyanov <[email-masked]>
Date: Thu, 19 Apr 2012 17:41:32 +0400

The mss_clamp is the only connection-time negotiated option which
cannot be obtained from the user space. Make the TCP_MAXSEG sockopt
report one in the repair mode.

Signed-off-by: Pavel Emelyanov <[email-masked]>
---
 net/ipv4/tcp.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 47e2f49..b4e690d 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2659,6 +2659,8 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
 		val = tp->mss_cache;
 		if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
 			val = tp->rx_opt.user_mss;
+		if (tp->repair)
+			val = tp->rx_opt.mss_clamp;
 		break;
 	case TCP_NODELAY:
 		val = !!(tp->nonagle&TCP_NAGLE_OFF);
-- 
1.5.5.6