[WIP] Add initial utilities for link and namespace actions

This change introduces basic utilities for managing interfaces, routes, and namespaces. See networkservicemesh#2 Signed-off-by: Ryan Tidwell <[email protected]>
rktidwell · Feb 4, 2020 · 9872207 · 9872207
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commit 9872207
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diff --git a/go.mod b/go.mod
@@ -3,4 +3,6 @@ module github.com/networkservicemesh/sdk-kernel
 go 1.13
 
 require (
+  github.com/vishvananda/netlink v1.0.0
+  github.com/vishvananda/netns v0.0.0-20190625233234-7109fa855b0f
 )
diff --git a/pkg/networkservice/kernelutils/namespaceutils.go b/pkg/networkservice/kernelutils/namespaceutils.go
@@ -0,0 +1,62 @@
+// Copyright 2019 VMware, Inc.
+// Copyright 2020 SUSE LLC.
+// SPDX-License-Identifier: Apache-2.0
+//
+// 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 kernelutils
+
+import (
+  "github.com/sirupsen/logrus"
+  "github.com/vishvananda/netlink"
+  "github.com/vishvananda/netns"
+)
+
+func InjectLinkInNamespace(targetNs netns.NsHandle, ifaceName string) error {
+  hostNs, nsErr := netns.Get()
+  defer hostNs.Close()
+  if nsErr != nil {
+    logrus.Errorf("sdk-kernel: failed to get host namespace")
+    return nsErr
+  }
+
+  /* Get a link object for the interface */
+  ifaceLink, linkErr := netlink.LinkByName(ifaceName)
+  if linkErr != nil {
+    // link was not found in host namespace, see if we can find it in target namespace
+    nsErr = netns.Set(targetNs)
+    defer netns.Set(hostNs)
+    if nsErr != nil {
+		  logrus.Errorf("sdk-kernel: failed switching to desired namespace: %v", nsErr)
+		  return nsErr
+	  }
+    _, linkErr := netlink.LinkByName(ifaceName)
+    if linkErr != nil {
+      // we didn't find the link in the target namespace either, return an error
+      return linkErr
+    }
+    nsErr = netns.Set(hostNs)
+    if nsErr != nil {
+		  logrus.Errorf("sdk-kernel: failed switching to host namespace: %v", nsErr)
+		  return nsErr
+	  }
+  } else {
+    /* Inject the interface into the desired namespace */
+    linkErr = netlink.LinkSetNsFd(ifaceLink, int(targetNs))
+    if linkErr != nil {
+      logrus.Errorf("sdk-kernel: failed to inject %q in namespace - %v", ifaceName, linkErr)
+      return linkErr
+    }
+  }
+  return nil
+}
diff --git a/pkg/networkservice/mechanisms/client.go b/pkg/networkservice/mechanisms/client.go
@@ -0,0 +1,250 @@
+// Copyright 2019 VMware, Inc.
+// SPDX-License-Identifier: Apache-2.0
+//
+// 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 kernelforwarder
+
+import (
+	"github.com/pkg/errors"
+
+	"github.com/networkservicemesh/networkservicemesh/controlplane/api/connection/mechanisms/common"
+	"github.com/networkservicemesh/networkservicemesh/controlplane/api/connection/mechanisms/vxlan"
+
+	"net"
+	"strconv"
+
+	"github.com/networkservicemesh/networkservicemesh/controlplane/api/connectioncontext"
+	"github.com/networkservicemesh/networkservicemesh/controlplane/api/crossconnect"
+
+	"github.com/sirupsen/logrus"
+	"github.com/vishvananda/netlink"
+	"github.com/vishvananda/netns"
+)
+
+// Kernel forwarding plane related constants
+const (
+	cLOCAL    = iota
+	cINCOMING = iota
+	cOUTGOING = iota
+)
+
+const (
+	/* VETH pairs are used only for local connections(same node), so we can use a larger MTU size as there's no multi-node connection */
+	cVETHMTU    = 16000
+	cCONNECT    = true
+	cDISCONNECT = false
+)
+
+type connectionConfig struct {
+	id            string
+	srcNetNsInode string
+	dstNetNsInode string
+	srcName       string
+	dstName       string
+	srcIP         string
+	dstIP         string
+	srcIPVXLAN    net.IP
+	dstIPVXLAN    net.IP
+	srcRoutes     []*connectioncontext.Route
+	dstRoutes     []*connectioncontext.Route
+	neighbors     []*connectioncontext.IpNeighbor
+	vni           int
+}
+
+// setupLinkInNs is responsible for configuring an interface inside a given namespace - assigns IP address, routes, etc.
+func setupLinkInNs(containerNs netns.NsHandle, ifaceName, ifaceIP string, routes []*connectioncontext.Route, neighbors []*connectioncontext.IpNeighbor, inject bool) error {
+	if inject {
+		/* Get a link object for the interface */
+		ifaceLink, err := netlink.LinkByName(ifaceName)
+		if err != nil {
+			logrus.Errorf("common: failed to get link for %q - %v", ifaceName, err)
+			return err
+		}
+		/* Inject the interface into the desired namespace */
+		if err = netlink.LinkSetNsFd(ifaceLink, int(containerNs)); err != nil {
+			logrus.Errorf("common: failed to inject %q in namespace - %v", ifaceName, err)
+			return err
+		}
+	}
+	/* Save current network namespace */
+	hostNs, err := netns.Get()
+	if err != nil {
+		logrus.Errorf("common: failed getting host namespace: %v", err)
+		return err
+	}
+	logrus.Debug("common: host namespace: ", hostNs)
+	defer func() {
+		if err = hostNs.Close(); err != nil {
+			logrus.Error("common: failed closing host namespace handle: ", err)
+		}
+		logrus.Debug("common: closed host namespace handle: ", hostNs)
+	}()
+
+	/* Switch to the desired namespace */
+	if err = netns.Set(containerNs); err != nil {
+		logrus.Errorf("common: failed switching to desired namespace: %v", err)
+		return err
+	}
+	logrus.Debug("common: switched to desired namespace: ", containerNs)
+
+	/* Don't forget to switch back to the host namespace */
+	defer func() {
+		if err = netns.Set(hostNs); err != nil {
+			logrus.Errorf("common: failed switching back to host namespace: %v", err)
+		}
+		logrus.Debug("common: switched back to host namespace: ", hostNs)
+	}()
+
+	/* Get a link for the interface name */
+	link, err := netlink.LinkByName(ifaceName)
+	if err != nil {
+		logrus.Errorf("common: failed to lookup %q, %v", ifaceName, err)
+		return err
+	}
+	if inject {
+		var addr *netlink.Addr
+		/* Parse the IP address */
+		addr, err = netlink.ParseAddr(ifaceIP)
+		if err != nil {
+			logrus.Errorf("common: failed to parse IP %q: %v", ifaceIP, err)
+			return err
+		}
+		/* Set IP address */
+		if err = netlink.AddrAdd(link, addr); err != nil {
+			logrus.Errorf("common: failed to set IP %q: %v", ifaceIP, err)
+			return err
+		}
+		/* Bring the interface UP */
+		if err = netlink.LinkSetUp(link); err != nil {
+			logrus.Errorf("common: failed to bring %q up: %v", ifaceName, err)
+			return err
+		}
+		/* Add routes */
+		if err = addRoutes(link, addr, routes); err != nil {
+			logrus.Error("common: failed adding routes:", err)
+			return err
+		}
+		/* Add neighbors - applicable only for source side */
+		if err = addNeighbors(link, neighbors); err != nil {
+			logrus.Error("common: failed adding neighbors:", err)
+			return err
+		}
+	} else {
+		/* Bring the interface DOWN */
+		if err = netlink.LinkSetDown(link); err != nil {
+			logrus.Errorf("common: failed to bring %q down: %v", ifaceName, err)
+			return err
+		}
+		/* Inject the interface back to current namespace */
+		if err = netlink.LinkSetNsFd(link, int(hostNs)); err != nil {
+			logrus.Errorf("common: failed to inject %q back to host namespace - %v", ifaceName, err)
+			return err
+		}
+	}
+	return nil
+}
+
+//nolint
+func newConnectionConfig(crossConnect *crossconnect.CrossConnect, connType uint8) (*connectionConfig, error) {
+	switch connType {
+	case cLOCAL:
+		return &connectionConfig{
+			id:            crossConnect.GetId(),
+			srcNetNsInode: crossConnect.GetSource().GetMechanism().GetParameters()[common.NetNsInodeKey],
+			dstNetNsInode: crossConnect.GetDestination().GetMechanism().GetParameters()[common.NetNsInodeKey],
+			srcName:       crossConnect.GetSource().GetMechanism().GetParameters()[common.InterfaceNameKey],
+			dstName:       crossConnect.GetDestination().GetMechanism().GetParameters()[common.InterfaceNameKey],
+			srcIP:         crossConnect.GetSource().GetContext().GetIpContext().GetSrcIpAddr(),
+			dstIP:         crossConnect.GetSource().GetContext().GetIpContext().GetDstIpAddr(),
+			srcRoutes:     crossConnect.GetSource().GetContext().GetIpContext().GetDstRoutes(),
+			dstRoutes:     crossConnect.GetDestination().GetContext().GetIpContext().GetSrcRoutes(),
+			neighbors:     crossConnect.GetSource().GetContext().GetIpContext().GetIpNeighbors(),
+		}, nil
+	case cINCOMING:
+		vni, _ := strconv.Atoi(crossConnect.GetSource().GetMechanism().GetParameters()[vxlan.VNI])
+		return &connectionConfig{
+			id:            crossConnect.GetId(),
+			dstNetNsInode: crossConnect.GetDestination().GetMechanism().GetParameters()[common.NetNsInodeKey],
+			dstName:       crossConnect.GetDestination().GetMechanism().GetParameters()[common.InterfaceNameKey],
+			dstIP:         crossConnect.GetDestination().GetContext().GetIpContext().GetDstIpAddr(),
+			dstRoutes:     crossConnect.GetDestination().GetContext().GetIpContext().GetSrcRoutes(),
+			neighbors:     nil,
+			srcIPVXLAN:    net.ParseIP(crossConnect.GetSource().GetMechanism().GetParameters()[vxlan.SrcIP]),
+			dstIPVXLAN:    net.ParseIP(crossConnect.GetSource().GetMechanism().GetParameters()[vxlan.DstIP]),
+			vni:           vni,
+		}, nil
+	case cOUTGOING:
+		vni, _ := strconv.Atoi(crossConnect.GetDestination().GetMechanism().GetParameters()[vxlan.VNI])
+		return &connectionConfig{
+			id:            crossConnect.GetId(),
+			srcNetNsInode: crossConnect.GetSource().GetMechanism().GetParameters()[common.NetNsInodeKey],
+			srcName:       crossConnect.GetSource().GetMechanism().GetParameters()[common.InterfaceNameKey],
+			srcIP:         crossConnect.GetSource().GetContext().GetIpContext().GetSrcIpAddr(),
+			srcRoutes:     crossConnect.GetSource().GetContext().GetIpContext().GetDstRoutes(),
+			neighbors:     crossConnect.GetSource().GetContext().GetIpContext().GetIpNeighbors(),
+			srcIPVXLAN:    net.ParseIP(crossConnect.GetDestination().GetMechanism().GetParameters()[vxlan.SrcIP]),
+			dstIPVXLAN:    net.ParseIP(crossConnect.GetDestination().GetMechanism().GetParameters()[vxlan.DstIP]),
+			vni:           vni,
+		}, nil
+	default:
+		logrus.Error("common: connection configuration: invalid connection type")
+		return nil, errors.New("common: invalid connection type")
+	}
+}
+
+// addRoutes adds routes
+func addRoutes(link netlink.Link, addr *netlink.Addr, routes []*connectioncontext.Route) error {
+	for _, route := range routes {
+		_, routeNet, err := net.ParseCIDR(route.GetPrefix())
+		if err != nil {
+			logrus.Error("common: failed parsing route CIDR:", err)
+			return err
+		}
+		route := netlink.Route{
+			LinkIndex: link.Attrs().Index,
+			Dst: &net.IPNet{
+				IP:   routeNet.IP,
+				Mask: routeNet.Mask,
+			},
+			Src: addr.IP,
+		}
+		if err = netlink.RouteAdd(&route); err != nil {
+			logrus.Error("common: failed adding routes:", err)
+			return err
+		}
+	}
+	return nil
+}
+
+// addNeighbors adds neighbors
+func addNeighbors(link netlink.Link, neighbors []*connectioncontext.IpNeighbor) error {
+	for _, neighbor := range neighbors {
+		mac, err := net.ParseMAC(neighbor.GetHardwareAddress())
+		if err != nil {
+			logrus.Error("common: failed parsing the MAC address for IP neighbors:", err)
+			return err
+		}
+		neigh := netlink.Neigh{
+			LinkIndex:    link.Attrs().Index,
+			State:        0x02, // netlink.NUD_REACHABLE, // the constant is somehow not being found in the package in case of using a darwin based machine
+			IP:           net.ParseIP(neighbor.GetIp()),
+			HardwareAddr: mac,
+		}
+		if err = netlink.NeighAdd(&neigh); err != nil {
+			logrus.Error("common: failed adding neighbor:", err)
+			return err
+		}
+	}
+	return nil
+}