From 00a4a5e056a565e81822af201987ff65bae00450 Mon Sep 17 00:00:00 2001
From: Matthias Radestock <matthias.radestock@gmail.com>
Date: Fri, 24 Oct 2014 13:15:15 +0100
Subject: [PATCH] refactor: simplify multicast route addition in 'attach'

---
 weave | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/weave b/weave
index 8afcf009..176461c5 100755
--- a/weave
+++ b/weave
@@ -191,13 +191,10 @@ attach() {
         return 1
     fi
 
-    if ip netns exec $NETNS ip route show | grep '^224\.0\.0\.0/4' >/dev/null ; then
-        # There's a multicast route already present, leave it alone.
-        return 0
-    fi
-
     # Route multicast packets across the weave network.
-    ip netns exec $NETNS ip route add 224.0.0.0/4 dev $CONTAINER_IFNAME
+    if ! ip netns exec $NETNS ip route show | grep '^224\.0\.0\.0/4' >/dev/null ; then
+        ip netns exec $NETNS ip route add 224.0.0.0/4 dev $CONTAINER_IFNAME
+    fi
 }
 
 detach() {