Restructured multus to use Go standard project layout.

pkg/netutils/netutils.go

@@ -0,0 +1,119 @@
+// Copyright (c) 2019 Multus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package netutils
+
+import (
+	"github.com/containernetworking/cni/pkg/skel"
+	cnitypes "github.com/containernetworking/cni/pkg/types"
+	"github.com/containernetworking/cni/pkg/types/current"
+	"github.com/containernetworking/plugins/pkg/ns"
+	"gopkg.in/intel/multus-cni.v3/pkg/logging"
+	"github.com/vishvananda/netlink"
+	"net"
+	"strings"
+)
+
+// DeleteDefaultGW removes the default gateway from marked interfaces.
+func DeleteDefaultGW(args *skel.CmdArgs, ifName string, res *cnitypes.Result) (*current.Result, error) {
+	result, err := current.NewResultFromResult(*res)
+	if err != nil {
+		return nil, logging.Errorf("DeleteDefaultGW: Error creating new from current CNI result: %v", err)
+	}
+
+	netns, err := ns.GetNS(args.Netns)
+	if err != nil {
+		return nil, logging.Errorf("DeleteDefaultGW: Error getting namespace %v", err)
+	}
+	defer netns.Close()
+
+	err = netns.Do(func(_ ns.NetNS) error {
+		var err error
+		link, _ := netlink.LinkByName(ifName)
+		routes, _ := netlink.RouteList(link, netlink.FAMILY_ALL)
+		for _, nlroute := range routes {
+			if nlroute.Dst == nil {
+				err = netlink.RouteDel(&nlroute)
+			}
+		}
+		return err
+	})
+	var newRoutes []*cnitypes.Route
+	for _, route := range result.Routes {
+		if mask, _ := route.Dst.Mask.Size(); mask != 0 {
+			newRoutes = append(newRoutes, route)
+		}
+	}
+	result.Routes = newRoutes
+	return result, err
+}
+
+// SetDefaultGW adds a default gateway on a specific interface
+func SetDefaultGW(args *skel.CmdArgs, ifName string, gateways []net.IP, res *cnitypes.Result) (*current.Result, error) {
+
+	// Use the current CNI result...
+	result, err := current.NewResultFromResult(*res)
+	if err != nil {
+		return nil, logging.Errorf("SetDefaultGW: Error creating new CNI result from current: %v", err)
+	}
+
+	// This ensures we're acting within the net namespace for the pod.
+	netns, err := ns.GetNS(args.Netns)
+	if err != nil {
+		return nil, logging.Errorf("SetDefaultGW: Error getting namespace %v", err)
+	}
+	defer netns.Close()
+
+	var newResultDefaultRoutes []*cnitypes.Route
+
+	// Do this within the net namespace.
+	err = netns.Do(func(_ ns.NetNS) error {
+		var err error
+
+		// Pick up the link info as we need the index.
+		link, _ := netlink.LinkByName(ifName)
+
+		// Cycle through all the desired gateways.
+		for _, gw := range gateways {
+
+			// Create a new route (note: dst is nil by default)
+			logging.Debugf("SetDefaultGW: Adding default route on %v (index: %v) to %v", ifName, link.Attrs().Index, gw)
+			newDefaultRoute := netlink.Route{
+				LinkIndex: link.Attrs().Index,
+				Gw:        gw,
+			}
+
+			// Build a new element for the results route
+
+			// Set a correct CIDR depending on IP type
+			_, dstipnet, _ := net.ParseCIDR("::0/0")
+			if strings.Count(gw.String(), ":") < 2 {
+				_, dstipnet, _ = net.ParseCIDR("0.0.0.0/0")
+			}
+			newResultDefaultRoutes = append(newResultDefaultRoutes, &cnitypes.Route{Dst: *dstipnet, GW: gw})
+
+			// Perform the creation of the default route....
+			err = netlink.RouteAdd(&newDefaultRoute)
+			if err != nil {
+				logging.Errorf("SetDefaultGW: Error adding route: %v", err)
+			}
+		}
+		return err
+	})
+
+	result.Routes = newResultDefaultRoutes
+	return result, err
+
+}