Merge pull request #116 from mavenugo/master

Incorrect assumption with golang net package causes Overlapping IP

libnetwork/drivers/bridge/setup_ipv4.go

@@ -35,7 +35,7 @@ func init() {
 			log.Errorf("Failed to parse address %s", addr)
 			continue
 		}
-		net.IP = ip
+		net.IP = ip.To4()
 		bridgeNetworks = append(bridgeNetworks, net)
 	}
 }

libnetwork/netutils/utils.go

@@ -192,7 +192,9 @@ func CheckRouteOverlaps(toCheck *net.IPNet) error {
 
 // NetworkOverlaps detects overlap between one IPNet and another
 func NetworkOverlaps(netX *net.IPNet, netY *net.IPNet) bool {
-	if len(netX.IP) == len(netY.IP) {
+	// Check if both netX and netY are ipv4 or ipv6
+	if (netX.IP.To4() != nil && netY.IP.To4() != nil) ||
+		(netX.IP.To4() == nil && netY.IP.To4() == nil) {
 		if firstIP, _ := NetworkRange(netX); netY.Contains(firstIP) {
 			return true
 		}