Merge pull request #508 from eyakubovich/mtu

net: add support for MTU config

Godeps/Godeps.json

@@ -70,7 +70,7 @@
 		},
 		{
 			"ImportPath": "github.com/vishvananda/netlink",
-			"Rev": "7f10b9c2b83cfebb282b60999505e8a72e1231a0"
+			"Rev": "a59b20a4021ab57ec6a89a4ad5fccfaede1fee77"
 		},
 		{
 			"ImportPath": "golang.org/x/crypto/cast5",

Godeps/_workspace/src/github.com/vishvananda/netlink/README.md

@@ -1,6 +1,6 @@
 # netlink - netlink library for go #
 
-[![Build Status](https://travis-ci.org/vishvananda/netlink.png?branch=master)](https://travis-ci.org/vishvananda/netlink)
+[![Build Status](https://travis-ci.org/vishvananda/netlink.png?branch=master)](https://travis-ci.org/vishvananda/netlink) [![GoDoc](https://godoc.org/github.com/vishvananda/netlink?status.svg)](https://godoc.org/github.com/vishvananda/netlink)
 
 The netlink package provides a simple netlink library for go. Netlink
 is the interface a user-space program in linux uses to communicate with

Godeps/_workspace/src/github.com/vishvananda/netlink/link_linux.go

@@ -80,6 +80,48 @@ func LinkSetMTU(link Link, mtu int) error {
 	return err
 }
 
+// LinkSetName sets the name of the link device.
+// Equivalent to: `ip link set $link name $name`
+func LinkSetName(link Link, name string) error {
+	base := link.Attrs()
+	ensureIndex(base)
+	req := nl.NewNetlinkRequest(syscall.RTM_SETLINK, syscall.NLM_F_ACK)
+
+	msg := nl.NewIfInfomsg(syscall.AF_UNSPEC)
+	msg.Type = syscall.RTM_SETLINK
+	msg.Flags = syscall.NLM_F_REQUEST
+	msg.Index = int32(base.Index)
+	msg.Change = nl.DEFAULT_CHANGE
+	req.AddData(msg)
+
+	data := nl.NewRtAttr(syscall.IFLA_IFNAME, []byte(name))
+	req.AddData(data)
+
+	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
+	return err
+}
+
+// LinkSetHardwareAddr sets the hardware address of the link device.
+// Equivalent to: `ip link set $link address $hwaddr`
+func LinkSetHardwareAddr(link Link, hwaddr net.HardwareAddr) error {
+	base := link.Attrs()
+	ensureIndex(base)
+	req := nl.NewNetlinkRequest(syscall.RTM_SETLINK, syscall.NLM_F_ACK)
+
+	msg := nl.NewIfInfomsg(syscall.AF_UNSPEC)
+	msg.Type = syscall.RTM_SETLINK
+	msg.Flags = syscall.NLM_F_REQUEST
+	msg.Index = int32(base.Index)
+	msg.Change = nl.DEFAULT_CHANGE
+	req.AddData(msg)
+
+	data := nl.NewRtAttr(syscall.IFLA_ADDRESS, []byte(hwaddr))
+	req.AddData(data)
+
+	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
+	return err
+}
+
 // LinkSetMaster sets the master of the link device.
 // Equivalent to: `ip link set $link master $master`
 func LinkSetMaster(link Link, master *Bridge) error {
@@ -263,6 +305,11 @@ func LinkAdd(link Link) error {
 	nameData := nl.NewRtAttr(syscall.IFLA_IFNAME, nl.ZeroTerminated(base.Name))
 	req.AddData(nameData)
 
+	if base.MTU > 0 {
+		mtu := nl.NewRtAttr(syscall.IFLA_MTU, nl.Uint32Attr(uint32(base.MTU)))
+		req.AddData(mtu)
+	}
+
 	linkInfo := nl.NewRtAttr(syscall.IFLA_LINKINFO, nil)
 	nl.NewRtAttrChild(linkInfo, nl.IFLA_INFO_KIND, nl.NonZeroTerminated(link.Type()))
 
@@ -279,6 +326,9 @@ func LinkAdd(link Link) error {
 		nl.NewIfInfomsgChild(peer, syscall.AF_UNSPEC)
 		nl.NewRtAttrChild(peer, syscall.IFLA_IFNAME, nl.ZeroTerminated(veth.PeerName))
 		nl.NewRtAttrChild(peer, syscall.IFLA_TXQLEN, nl.Uint32Attr(base.TxQLen))
+		if base.MTU > 0 {
+			nl.NewRtAttrChild(peer, syscall.IFLA_MTU, nl.Uint32Attr(uint32(base.MTU)))
+		}
 	} else if vxlan, ok := link.(*Vxlan); ok {
 		addVxlanAttrs(vxlan, linkInfo)
 	}

Godeps/_workspace/src/github.com/vishvananda/netlink/link_test.go

@@ -1,6 +1,8 @@
 package netlink
 
 import (
+	"bytes"
+	"net"
 	"testing"
 
 	"github.com/vishvananda/netns"
@@ -52,6 +54,9 @@ func testLinkAddDel(t *testing.T, link Link) {
 		if veth.TxQLen != testTxQLen {
 			t.Fatalf("TxQLen is %d, should be %d", veth.TxQLen, testTxQLen)
 		}
+		if rBase.MTU != base.MTU {
+			t.Fatalf("MTU is %d, should be %d", rBase.MTU, base.MTU)
+		}
 
 		if veth.PeerName != "" {
 			var peer *Veth
@@ -156,7 +161,7 @@ func TestLinkAddDelBridge(t *testing.T) {
 	tearDown := setUpNetlinkTest(t)
 	defer tearDown()
 
-	testLinkAddDel(t, &Bridge{LinkAttrs{Name: "foo"}})
+	testLinkAddDel(t, &Bridge{LinkAttrs{Name: "foo", MTU: 1400}})
 }
 
 func TestLinkAddDelVlan(t *testing.T) {
@@ -195,7 +200,7 @@ func TestLinkAddDelVeth(t *testing.T) {
 	tearDown := setUpNetlinkTest(t)
 	defer tearDown()
 
-	testLinkAddDel(t, &Veth{LinkAttrs{Name: "foo", TxQLen: testTxQLen}, "bar"})
+	testLinkAddDel(t, &Veth{LinkAttrs{Name: "foo", TxQLen: testTxQLen, MTU: 1400}, "bar"})
 }
 
 func TestLinkAddDelBridgeMaster(t *testing.T) {
@@ -399,3 +404,61 @@ func TestLinkByIndex(t *testing.T) {
 		t.Fatalf("LinkByIndex(%v) found deleted link", err)
 	}
 }
+
+func TestLinkSet(t *testing.T) {
+	tearDown := setUpNetlinkTest(t)
+	defer tearDown()
+
+	iface := &Dummy{LinkAttrs{Name: "foo"}}
+	if err := LinkAdd(iface); err != nil {
+		t.Fatal(err)
+	}
+
+	link, err := LinkByName("foo")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = LinkSetName(link, "bar")
+	if err != nil {
+		t.Fatalf("Could not change interface name: %v", err)
+	}
+
+	link, err = LinkByName("bar")
+	if err != nil {
+		t.Fatalf("Interface name not changed: %v", err)
+	}
+
+	err = LinkSetMTU(link, 1400)
+	if err != nil {
+		t.Fatalf("Could not set MTU: %v", err)
+	}
+
+	link, err = LinkByName("bar")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if link.Attrs().MTU != 1400 {
+		t.Fatal("MTU not changed!")
+	}
+
+	addr, err := net.ParseMAC("00:12:34:56:78:AB")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = LinkSetHardwareAddr(link, addr)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	link, err = LinkByName("bar")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !bytes.Equal(link.Attrs().HardwareAddr, addr) {
+		t.Fatalf("hardware address not changed!")
+	}
+}

Godeps/_workspace/src/github.com/vishvananda/netlink/nl/nl_linux.go

@@ -248,6 +248,9 @@ done:
 				continue
 			}
 			res = append(res, m.Data)
+			if m.Header.Flags&syscall.NLM_F_MULTI == 0 {
+				break done
+			}
 		}
 	}
 	return res, nil

Godeps/_workspace/src/github.com/vishvananda/netlink/route.go

@@ -30,6 +30,6 @@ type Route struct {
 }
 
 func (r Route) String() string {
-	return fmt.Sprintf("{Ifindex: %d Dst: %s Src: %s Gw: %s}", r.LinkIndex, r.Dst.String(),
+	return fmt.Sprintf("{Ifindex: %d Dst: %s Src: %s Gw: %s}", r.LinkIndex, r.Dst,
 		r.Src, r.Gw)
 }

Godeps/_workspace/src/github.com/vishvananda/netlink/route_linux.go

@@ -164,3 +164,62 @@ func RouteList(link Link, family int) ([]Route, error) {
 
 	return res, nil
 }
+
+// RouteGet gets a route to a specific destination from the host system.
+// Equivalent to: 'ip route get'.
+func RouteGet(destination net.IP) ([]Route, error) {
+	req := nl.NewNetlinkRequest(syscall.RTM_GETROUTE, syscall.NLM_F_REQUEST)
+	family := nl.GetIPFamily(destination)
+	var destinationData []byte
+	var bitlen uint8
+	if family == FAMILY_V4 {
+		destinationData = destination.To4()
+		bitlen = 32
+	} else {
+		destinationData = destination.To16()
+		bitlen = 128
+	}
+	msg := &nl.RtMsg{}
+	msg.Family = uint8(family)
+	msg.Dst_len = bitlen
+	req.AddData(msg)
+
+	rtaDst := nl.NewRtAttr(syscall.RTA_DST, destinationData)
+	req.AddData(rtaDst)
+
+	msgs, err := req.Execute(syscall.NETLINK_ROUTE, syscall.RTM_NEWROUTE)
+	if err != nil {
+		return nil, err
+	}
+
+	native := nl.NativeEndian()
+	res := make([]Route, 0)
+	for _, m := range msgs {
+		msg := nl.DeserializeRtMsg(m)
+		attrs, err := nl.ParseRouteAttr(m[msg.Len():])
+		if err != nil {
+			return nil, err
+		}
+
+		route := Route{}
+		for _, attr := range attrs {
+			switch attr.Attr.Type {
+			case syscall.RTA_GATEWAY:
+				route.Gw = net.IP(attr.Value)
+			case syscall.RTA_PREFSRC:
+				route.Src = net.IP(attr.Value)
+			case syscall.RTA_DST:
+				route.Dst = &net.IPNet{
+					IP:   attr.Value,
+					Mask: net.CIDRMask(int(msg.Dst_len), 8*len(attr.Value)),
+				}
+			case syscall.RTA_OIF:
+				routeIndex := int(native.Uint32(attr.Value[0:4]))
+				route.LinkIndex = routeIndex
+			}
+		}
+		res = append(res, route)
+	}
+	return res, nil
+
+}

Godeps/_workspace/src/github.com/vishvananda/netlink/route_test.go

@@ -34,7 +34,17 @@ func TestRouteAddDel(t *testing.T) {
 		t.Fatal(err)
 	}
 	if len(routes) != 1 {
-		t.Fatal("Link not removed properly")
+		t.Fatal("Link not added properly")
+	}
+
+	dstIP := net.ParseIP("192.168.0.42")
+	routeToDstIP, err := RouteGet(dstIP)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(routeToDstIP) == 0 {
+		t.Fatal("Default route not present")
 	}
 
 	err = RouteDel(&route)

networking/net/bridge/bridge.go

@@ -37,6 +37,7 @@ type Net struct {
 	BrName string `json:"bridgeName"`
 	IsGW   bool   `json:"isGateway"`
 	IPMasq bool   `json:"ipMasq"`
+	MTU    int    `json:"mtu"`
 }
 
 func init() {
@@ -93,10 +94,11 @@ func bridgeByName(name string) (*netlink.Bridge, error) {
 	return br, nil
 }
 
-func ensureBridge(brName string, ipn *net.IPNet) (*netlink.Bridge, error) {
+func ensureBridge(brName string, mtu int, ipn *net.IPNet) (*netlink.Bridge, error) {
 	br := &netlink.Bridge{
 		LinkAttrs: netlink.LinkAttrs{
 			Name: brName,
+			MTU:  mtu,
 		},
 	}
 
@@ -123,12 +125,12 @@ func ensureBridge(brName string, ipn *net.IPNet) (*netlink.Bridge, error) {
 	return br, nil
 }
 
-func setupVeth(contID types.UUID, netns string, br *netlink.Bridge, ifName string, ipConf *ipam.IPConfig) error {
+func setupVeth(contID types.UUID, netns string, br *netlink.Bridge, ifName string, mtu int, ipConf *ipam.IPConfig) error {
 	var hostVethName string
 
 	err := util.WithNetNSPath(netns, func(hostNS *os.File) error {
 		// create the veth pair in the container and move host end into host netns
-		hostVeth, _, err := util.SetupVeth(contID.String(), ifName, nil, hostNS)
+		hostVeth, _, err := util.SetupVeth(contID.String(), ifName, mtu, hostNS)
 		if err != nil {
 			return err
 		}
@@ -173,7 +175,7 @@ func setupBridge(n *Net, ipConf *ipam.IPConfig) (*netlink.Bridge, error) {
 	}
 
 	// create bridge if necessary
-	br, err := ensureBridge(n.BrName, gwn)
+	br, err := ensureBridge(n.BrName, n.MTU, gwn)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create bridge %q: %v", n.BrName, err)
 	}
@@ -207,7 +209,7 @@ func cmdAdd(contID, netns, netConf, ifName string) error {
 		return err
 	}
 
-	if err = setupVeth(*cid, netns, br, ifName, ipConf); err != nil {
+	if err = setupVeth(*cid, netns, br, ifName, n.MTU, ipConf); err != nil {
 		return err
 	}
 

networking/net/veth/veth.go

@@ -38,14 +38,15 @@ func init() {
 type Net struct {
 	rktnet.Net
 	IPMasq bool `json:"ipMasq"`
+	MTU    int  `json:"mtu"`
 }
 
-func setupContVeth(contID, netns, ifName string, ipConf *ipam.IPConfig) (string, error) {
+func setupContVeth(contID, netns, ifName string, mtu int, ipConf *ipam.IPConfig) (string, error) {
 	var hostVethName string
 	err := util.WithNetNSPath(netns, func(hostNS *os.File) error {
 		entropy := contID + ifName
 
-		hostVeth, _, err := util.SetupVeth(entropy, ifName, nil, hostNS)
+		hostVeth, _, err := util.SetupVeth(entropy, ifName, mtu, hostNS)
 		if err != nil {
 			return err
 		}
@@ -99,7 +100,7 @@ func cmdAdd(contID, netns, netConf, ifName, args string) error {
 		return err
 	}
 
-	hostVethName, err := setupContVeth(contID, netns, ifName, ipConf)
+	hostVethName, err := setupContVeth(contID, netns, ifName, conf.MTU, ipConf)
 	if err != nil {
 		return err
 	}

networking/util/link.go

@@ -23,11 +23,12 @@ import (
 	"github.com/coreos/rocket/Godeps/_workspace/src/github.com/vishvananda/netlink"
 )
 
-func makeVeth(name, peer string) (netlink.Link, error) {
+func makeVeth(name, peer string, mtu int) (netlink.Link, error) {
 	veth := &netlink.Veth{
 		LinkAttrs: netlink.LinkAttrs{
 			Name:  name,
 			Flags: net.FlagUp,
+			MTU:   mtu,
 		},
 		PeerName: peer,
 	}
@@ -47,10 +48,10 @@ func hash(s string) string {
 // SetupVeth sets up a virtual ethernet link.
 // Should be in container netns.
 // TODO(eyakubovich): get rid of entropy and ask kernel to pick name via pattern
-func SetupVeth(entropy, contVethName string, ipn *net.IPNet, hostNS *os.File) (hostVeth, contVeth netlink.Link, err error) {
+func SetupVeth(entropy, contVethName string, mtu int, hostNS *os.File) (hostVeth, contVeth netlink.Link, err error) {
 	// NetworkManager (recent versions) will ignore veth devices that start with "veth"
 	hostVethName := "veth" + hash(entropy)[:4]
-	hostVeth, err = makeVeth(hostVethName, contVethName)
+	hostVeth, err = makeVeth(hostVethName, contVethName, mtu)
 	if err != nil {
 		err = fmt.Errorf("failed to make veth pair: %v", err)
 		return
@@ -72,14 +73,6 @@ func SetupVeth(entropy, contVethName string, ipn *net.IPNet, hostNS *os.File) (h
 		return
 	}
 
-	if ipn != nil {
-		addr := &netlink.Addr{IPNet: ipn, Label: ""}
-		if err = netlink.AddrAdd(contVeth, addr); err != nil {
-			err = fmt.Errorf("failed to add IP addr to veth: %v", err)
-			return
-		}
-	}
-
 	if err = netlink.LinkSetNsFd(hostVeth, int(hostNS.Fd())); err != nil {
 		err = fmt.Errorf("failed to move veth to host netns: %v", err)
 		return