From 333c47a42a175f5ab4418c8aabfc9813c55ee886 Mon Sep 17 00:00:00 2001
From: Chion Tang <sdspeed@sina.com>
Date: Tue, 22 Dec 2015 14:07:04 +0800
Subject: [PATCH] Add keepalive feature for remote connections

---
 src/redir.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/redir.c b/src/redir.c
index 05d6b7dc..b6511bea 100644
--- a/src/redir.c
+++ b/src/redir.c
@@ -605,6 +605,16 @@ static void accept_cb(EV_P_ ev_io *w, int revents)
     setsockopt(remotefd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof(opt));
 #endif
 
+    //Enable TCP keepalive feature
+    int keepAlive = 1;
+    int keepIdle = 40;
+    int keepInterval = 20;
+    int keepCount = 5;
+    setsockopt(remotefd, SOL_SOCKET, SO_KEEPALIVE, (void*)&keepAlive, sizeof(keepAlive));
+    setsockopt(remotefd, SOL_TCP, TCP_KEEPIDLE, (void*)&keepIdle, sizeof(keepIdle));
+    setsockopt(remotefd, SOL_TCP, TCP_KEEPINTVL, (void*)&keepInterval, sizeof(keepInterval));
+    setsockopt(remotefd, SOL_TCP, TCP_KEEPCNT, (void*)&keepCount, sizeof(keepCount));
+    
     // Setup
     setnonblocking(remotefd);