avoid a race condition that might lead to dnsmasq reading an empty resolv.conf (#2007)

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@7952 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 4 insertions, 3 deletions

diff --git a/package/base-files/files/usr/share/udhcpc/default.script b/package/base-files/files/usr/share/udhcpc/default.script
index a3a696be7..7ce3d2aa8 100755
--- a/package/base-files/files/usr/share/udhcpc/default.script
+++ b/package/base-files/files/usr/share/udhcpc/default.script
@@ -47,12 +47,13 @@ case "$1" in
 		}
 		
 		[ -n "$dns" ] && {
-			echo -n > $RESOLV_CONF
-			${domain:+echo search $domain} >> $RESOLV_CONF
+			echo -n > "${RESOLV_CONF}.tmp"
+			${domain:+echo search $domain} >> "${RESOLV_CONF}.tmp"
 			for i in $dns ; do
 				echo "adding dns $i"
-				echo "nameserver $i" >> $RESOLV_CONF
+				echo "nameserver $i" >> "${RESOLV_CONF}.tmp"
 			done
+			mv "${RESOLV_CONF}.tmp" "$RESOLV_CONF"
 		}
 		
 		hotplug_event ifup