network: Don't store the network info as pointers if slices used

By storing the network information such as routes as pointers, we
end up having issues if we try to remove some elements from the list
as at the same time this list is parsed through by a loop.

For interfaces, we can use maps instead, because we have a way to
keep track of them based on their names. Maps are safer and allow
to keep pointers in this case.

In both cases, routes and interfaces list can be modified properly
while we loop over every items.

Fixes kata-containers#226

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

grpc.go

@@ -853,6 +853,7 @@ func (a *agentGRPC) CreateSandbox(ctx context.Context, req *pb.CreateSandboxRequ
 
 	a.sandbox.id = req.Hostname
 	a.sandbox.containers = make(map[string]*container)
+	a.sandbox.network.ifaces = make(map[string]*pb.Interface)
 	a.sandbox.network.dns = req.Dns
 	a.sandbox.running = true
 

network.go

@@ -25,10 +25,10 @@ import (
 // related information.
 type network struct {
 	ifacesLock sync.Mutex
-	ifaces     []*pb.Interface
+	ifaces     map[string]*pb.Interface
 
 	routesLock sync.Mutex
-	routes     []*pb.Route
+	routes     []pb.Route
 
 	dns []string
 }
@@ -139,7 +139,7 @@ func (s *sandbox) addInterface(netHandle *netlink.Handle, iface *pb.Interface) (
 	}
 
 	// Update sandbox interface list.
-	s.network.ifaces = append(s.network.ifaces, iface)
+	s.network.ifaces[iface.Name] = iface
 
 	return iface, nil
 }
@@ -172,12 +172,7 @@ func (s *sandbox) removeInterface(netHandle *netlink.Handle, iface *pb.Interface
 	}
 
 	// Update sandbox interface list.
-	for idx, sIface := range s.network.ifaces {
-		if sIface.Name == iface.Name {
-			s.network.ifaces = append(s.network.ifaces[:idx], s.network.ifaces[idx+1:]...)
-			break
-		}
-	}
+	delete(s.network.ifaces, iface.Name)
 
 	return nil, nil
 }
@@ -465,7 +460,7 @@ func (s *sandbox) updateRoute(netHandle *netlink.Handle, route *pb.Route, add bo
 		}
 
 		// Add route to sandbox route list.
-		s.network.routes = append(s.network.routes, route)
+		s.network.routes = append(s.network.routes, *route)
 	} else {
 		if err := netHandle.RouteDel(netRoute); err != nil {
 			return grpcStatus.Errorf(codes.Internal, "Could not remove route dest(%s)/gw(%s)/dev(%s): %v",
@@ -508,8 +503,9 @@ func (s *sandbox) removeNetwork() error {
 	}
 	defer netHandle.Delete()
 
-	for _, route := range s.network.routes {
-		if err := s.removeRoute(netHandle, route); err != nil {
+	routeList := s.network.routes
+	for _, route := range routeList {
+		if err := s.removeRoute(netHandle, &route); err != nil {
 			return grpcStatus.Errorf(codes.Internal, "Could not remove network route %v: %v",
 				route, err)
 		}