From f2fdd8ebdb1617218201d16eeb54a5a905768764 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@openwrt.org>
Date: Sat, 29 Mar 2014 17:05:35 +0000
Subject: [PATCH] dropbear: add options SSHKeepAlive and IdleTimeout.

Without timeout mechanism, if ssh client disconnected without sending
FIN or RST, forked dropbear servers would hang there for
KEX_RETRY_TIMEOUT seconds (8 hours).

TCP keepalive is not implemented in dropbear yet, thus the name
SSHKeepAlive.

300 seconds in this patch is selected from the default value of
ServerAliveInterval for Debian ssh client (See man ssh_config).

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

SVN-Revision: 40299
---
 package/network/services/dropbear/files/dropbear.init | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/package/network/services/dropbear/files/dropbear.init b/package/network/services/dropbear/files/dropbear.init
index 93dc3d9694..19aab3653b 100755
--- a/package/network/services/dropbear/files/dropbear.init
+++ b/package/network/services/dropbear/files/dropbear.init
@@ -44,7 +44,9 @@ validate_section_dropbear()
 		'rsakeyfile:file' \
 		'dsskeyfile:file' \
 		'BannerFile:file' \
-		'Port:list(port):22'
+		'Port:list(port):22' \
+		'SSHKeepAlive:uinteger:300' \
+		'IdleTimeout:uinteger:0'
 	return $?
 }
 
@@ -74,6 +76,8 @@ dropbear_instance()
 	[ -n "${BannerFile}" ] && procd_append_param command -b "${BannerFile}"
 	[ -n "${Interface}" ] && network_get_device Interface "${Interface}"
 	append_ports "${Interface}" "${Port}"
+	[ "${IdleTimeout}" -ne 0 ] && procd_append_param command -I "${IdleTimeout}"
+	[ "${SSHKeepAlive}" -ne 0 ] && procd_append_param command -K "${SSHKeepAlive}"
 	procd_close_instance
 }
 
-- 
2.30.2