Migrate tools veth to new link structs (#1523)

* use new link structs in tools veth commands * cleanup * cleanup2 * cleanup3 * use clab NewNode to create fake nodes for link resolving * remove commented veth create tests * use existing iface for link impairments * added runtime exec for podman --------- Co-authored-by: Roman Dodin <[email protected]>
srl-labs · Oct 6, 2023 · f15864b · f15864b
1 parent d38bdf3
commit f15864b
Show file tree

Hide file tree

Showing 15 changed files with 312 additions and 402 deletions.
diff --git a/clab/config.go b/clab/config.go
@@ -29,8 +29,8 @@ const (
 	dockerNetName     = "clab"
 	dockerNetIPv4Addr = "172.20.20.0/24"
 	dockerNetIPv6Addr = "2001:172:20:20::/64"
-	// NSPath value assigned to host interfaces.
-	hostNSPath = "__host"
+	// veth link mtu.
+	DefaultVethLinkMTU = 9500
 
 	// clab specific topology variables.
 	clabDirVar = "__clabDir__"

diff --git a/clab/netlink.go b/clab/netlink.go
@@ -6,148 +6,14 @@ package clab
 
 import (
 	"fmt"
-	"net"
+	"strings"
 
-	"github.com/containernetworking/plugins/pkg/ns"
-	"github.com/google/uuid"
 	log "github.com/sirupsen/logrus"
-	"github.com/srl-labs/containerlab/nodes/srl"
 	"github.com/srl-labs/containerlab/types"
 	"github.com/srl-labs/containerlab/utils"
 	"github.com/vishvananda/netlink"
 )
 
-type vEthEndpoint struct {
-	Link      netlink.Link
-	LinkName  string
-	NSName    string // netns name
-	NSPath    string // netns path
-	Bridge    string // bridge name a veth is destined to be connected to
-	OvsBridge string // ovs-bridge name a veth is destined to be connected to
-}
-
-// CreateVirtualWiring creates the virtual topology between the containers.
-func (c *CLab) CreateVirtualWiring(l *types.Link) (err error) {
-	log.Infof("Creating virtual wire: %s:%s <--> %s:%s", l.A.Node.ShortName, l.A.EndpointName, l.B.Node.ShortName, l.B.EndpointName)
-
-	// connect containers (or container and a bridge) using veth pair
-	// based on the link configuration contained within *Link struct
-	// veth side A
-	vA := vEthEndpoint{
-		LinkName: l.A.EndpointName,
-		NSName:   l.A.Node.LongName,
-		NSPath:   l.A.Node.NSPath,
-	}
-	// veth side B
-	vB := vEthEndpoint{
-		LinkName: l.B.EndpointName,
-		NSName:   l.B.Node.LongName,
-		NSPath:   l.B.Node.NSPath,
-	}
-
-	// get random names for veth sides as they will be created in root netns first
-	ARndmName := fmt.Sprintf("clab-%s", genIfName())
-	BRndmName := fmt.Sprintf("clab-%s", genIfName())
-
-	// set bridge name for endpoint that should be connect to linux bridge
-	switch {
-	case l.A.Node.Kind == "bridge":
-
-		// mgmt-net is a reserved node name that means
-		// connect this endpoint to docker management bridged network
-		if l.A.Node.ShortName != "mgmt-net" {
-			vA.Bridge = l.A.Node.ShortName
-		} else {
-			vA.Bridge = c.Config.Mgmt.Bridge
-		}
-		// veth endpoint destined to connect to the bridge in the host netns
-		// will not have a random name
-		ARndmName = l.A.EndpointName
-	case l.B.Node.Kind == "bridge":
-		if l.B.Node.ShortName != "mgmt-net" {
-			vB.Bridge = l.B.Node.ShortName
-		} else {
-			vB.Bridge = c.Config.Mgmt.Bridge
-		}
-		BRndmName = l.B.EndpointName
-	case l.A.Node.Kind == "ovs-bridge":
-		vA.OvsBridge = l.A.Node.ShortName
-		ARndmName = l.A.EndpointName
-	case l.B.Node.Kind == "ovs-bridge":
-		vB.OvsBridge = l.B.Node.ShortName
-		BRndmName = l.B.EndpointName
-	// for host connections random names shouldn't be used
-	case l.A.Node.Kind == "host":
-		ARndmName = l.A.EndpointName
-	case l.B.Node.Kind == "host":
-		BRndmName = l.B.EndpointName
-	}
-
-	// Generate MAC addresses
-	aMAC, err := net.ParseMAC(l.A.MAC)
-	if err != nil {
-		return err
-	}
-	bMAC, err := net.ParseMAC(l.B.MAC)
-	if err != nil {
-		return err
-	}
-
-	// if one of the endpoints is a macvlan interface
-	// we need to create a macvlan interface in the root netns
-	if l.A.Node.Kind == "macvlan" || l.B.Node.Kind == "macvlan" {
-		// make sure the macvlan is always the B side
-		if l.A.Node.Kind == "macvlan" {
-			tmp := l.A
-			l.A = l.B
-			l.B = tmp
-		}
-
-		link, err := createMACVLANInterface(ARndmName, l.B.EndpointName, l.MTU, aMAC)
-		if err != nil {
-			return err
-		}
-
-		err = toNS(l.A.Node.NSPath, link, l.A.EndpointName)
-		if err != nil {
-			return err
-		}
-
-		// SR Linux brings down non-veth interfaces, so we have to force them up after SR Linux is started.
-		for _, kn := range srl.KindNames {
-			if l.A.Node.Kind == kn {
-				l.A.Node.Exec = append([]string{fmt.Sprintf("ip l set dev %s up", l.A.EndpointName)}, l.A.Node.Exec...)
-			}
-		}
-
-	} else {
-
-		// create veth pair in the root netns
-		vA.Link, vB.Link, err = createVethIface(ARndmName, BRndmName, l.MTU, aMAC, bMAC)
-		if err != nil {
-			return err
-		}
-
-		// once veth pair is created, disable tx offload for veth pair
-		if err := utils.EthtoolTXOff(ARndmName); err != nil {
-			return err
-		}
-		if err := utils.EthtoolTXOff(BRndmName); err != nil {
-			return err
-		}
-
-		if err = vA.setVethLink(); err != nil {
-			_ = netlink.LinkDel(vA.Link)
-			return err
-		}
-		if err = vB.setVethLink(); err != nil {
-			_ = netlink.LinkDel(vB.Link)
-		}
-	}
-
-	return err
-}
-
 // RemoveHostOrBridgeVeth tries to remove veths connected to the host network namespace or a linux bridge
 // and does nothing in case they are not found.
 func (c *CLab) RemoveHostOrBridgeVeth(l *types.Link) (err error) {
@@ -184,134 +50,25 @@ func (c *CLab) RemoveHostOrBridgeVeth(l *types.Link) (err error) {
 	return nil
 }
 
-// createMACVLANInterface creates a macvlan interface in the root netns.
-func createMACVLANInterface(ifName, parentIfName string, mtu int, MAC net.HardwareAddr) (netlink.Link, error) {
-	parentInterface, err := utils.LinkByNameOrAlias(parentIfName)
-	if err != nil {
-		return nil, err
-	}
-
-	mvl := &netlink.Macvlan{
-		LinkAttrs: netlink.LinkAttrs{
-			Name:         ifName,
-			ParentIndex:  parentInterface.Attrs().Index,
-			HardwareAddr: MAC,
-		},
-		Mode: netlink.MACVLAN_MODE_BRIDGE,
+// GetLinksByNamePrefix returns a list of links whose name matches a prefix.
+func GetLinksByNamePrefix(prefix string) ([]netlink.Link, error) {
+	// filtered list of interfaces
+	if prefix == "" {
+		return nil, fmt.Errorf("prefix is not specified")
 	}
+	var fls []netlink.Link
 
-	err = netlink.LinkAdd(mvl)
+	ls, err := netlink.LinkList()
 	if err != nil {
 		return nil, err
 	}
-
-	return mvl, nil
-}
-
-// createVethIface takes two veth endpoint structs and create a veth pair and return
-// veth interface links.
-func createVethIface(ifName, peerName string, mtu int, aMAC, bMAC net.HardwareAddr) (linkA, linkB netlink.Link, err error) {
-	linkA = &netlink.Veth{
-		LinkAttrs: netlink.LinkAttrs{
-			Name:         ifName,
-			HardwareAddr: aMAC,
-			Flags:        net.FlagUp,
-			MTU:          mtu,
-		},
-		PeerName:         peerName,
-		PeerHardwareAddr: bMAC,
-	}
-
-	if err := netlink.LinkAdd(linkA); err != nil {
-		return nil, nil, err
-	}
-
-	if linkB, err = utils.LinkByNameOrAlias(peerName); err != nil {
-		err = fmt.Errorf("failed to lookup %q: %v", peerName, err)
-	}
-
-	return
-}
-
-// setVethLink sets the veth link endpoints to the relevant namespaces and/or connects one end to the bridge.
-func (veth *vEthEndpoint) setVethLink() error {
-	// if veth is destined to connect to a linux bridge in the host netns
-	if veth.Bridge != "" {
-		return veth.toBridge()
-	}
-	if veth.OvsBridge != "" {
-		return veth.toOvsBridge()
-	}
-	// host endpoints have a special NSPath value
-	// the host portion of veth doesn't need to be additionally processed
-	if veth.NSPath == hostNSPath {
-		if err := netlink.LinkSetUp(veth.Link); err != nil {
-			return fmt.Errorf("failed to set %q up: %v",
-				veth.LinkName, err)
+	for _, l := range ls {
+		if strings.HasPrefix(l.Attrs().Name, prefix) {
+			fls = append(fls, l)
 		}
-		return nil
 	}
-	// otherwise it needs to be put into a netns
-	return veth.toNS()
-}
-
-// toNS puts a veth endpoint to a given netns and renames its random name to a desired name.
-func (veth *vEthEndpoint) toNS() error {
-	return toNS(veth.NSPath, veth.Link, veth.LinkName)
-}
-
-func toNS(nsPath string, link netlink.Link, expectedName string) error {
-	var vethNS ns.NetNS
-	var err error
-	if vethNS, err = ns.GetNS(nsPath); err != nil {
-		return err
-	}
-	// move veth endpoint to namespace
-	if err = netlink.LinkSetNsFd(link, int(vethNS.Fd())); err != nil {
-		return err
+	if len(fls) == 0 {
+		return nil, fmt.Errorf("no links found by specified prefix %s", prefix)
 	}
-	err = vethNS.Do(func(_ ns.NetNS) error {
-		if err = netlink.LinkSetName(link, expectedName); err != nil {
-			return fmt.Errorf(
-				"failed to rename link: %v", err)
-		}
-
-		if err = netlink.LinkSetUp(link); err != nil {
-			return fmt.Errorf("failed to set %q up: %v",
-				expectedName, err)
-		}
-		return nil
-	})
-	return err
-}
-
-func (veth *vEthEndpoint) toBridge() error {
-	var vethNS ns.NetNS
-	var err error
-	// bridge is in the host netns, thus we need to get current netns
-	if vethNS, err = ns.GetCurrentNS(); err != nil {
-		return err
-	}
-	err = vethNS.Do(func(_ ns.NetNS) error {
-		br, err := utils.BridgeByName(veth.Bridge)
-		if err != nil {
-			return err
-		}
-
-		// connect host veth end to the bridge
-		if err := netlink.LinkSetMaster(veth.Link, br); err != nil {
-			return fmt.Errorf("failed to connect %q to bridge %v: %v", veth.LinkName, veth.Bridge, err)
-		}
-
-		if err = netlink.LinkSetUp(veth.Link); err != nil {
-			return fmt.Errorf("failed to set %q up: %v", veth.LinkName, err)
-		}
-		return nil
-	})
-	return err
-}
-
-func genIfName() string {
-	s, _ := uuid.New().MarshalText() // .MarshalText() always return a nil error
-	return string(s[:8])
+	return fls, nil
 }
diff --git a/clab/ovs.go b/clab/ovs.go