From 58c834c4f3eb090c2c64e4dbc6c69f46f1baf483 Mon Sep 17 00:00:00 2001
From: Jay Dunkelberger <ldunkelberger@pivotal.io>
Date: Thu, 9 Mar 2017 13:55:15 -0800
Subject: [PATCH] pkg/ip: do not leak types from vendored netlink package

The exported function SetupVeth now returns a package-defined type.

Signed-off-by: Gabe Rosenhouse <grosenhouse@pivotal.io>
---
 pkg/ip/link.go          | 46 ++++++++++++++++++++++++++++++-----------
 pkg/ip/link_test.go     |  4 ++--
 plugins/main/ptp/ptp.go | 10 ++++-----
 3 files changed, 41 insertions(+), 19 deletions(-)

diff --git a/pkg/ip/link.go b/pkg/ip/link.go
index 6431bb41..8900f653 100644
--- a/pkg/ip/link.go
+++ b/pkg/ip/link.go
@@ -98,30 +98,49 @@ func RenameLink(curName, newName string) error {
 	return err
 }
 
+type LinkAttrs struct {
+	Name         string
+	HardwareAddr net.HardwareAddr
+	Index        int
+}
+
+type link struct {
+	netlink.Link
+}
+
+func (l *link) Attrs() LinkAttrs {
+	a := l.Link.Attrs()
+	return LinkAttrs{
+		Name:         a.Name,
+		HardwareAddr: a.HardwareAddr,
+		Index:        a.Index,
+	}
+}
+
+type Link interface {
+	Attrs() LinkAttrs
+}
+
 // SetupVeth sets up a virtual ethernet link.
 // Should be in container netns, and will switch back to hostNS to set the host
 // veth end up.
-func SetupVeth(contVethName string, mtu int, hostNS ns.NetNS) (hostVeth, contVeth netlink.Link, err error) {
-	var hostVethName string
-	hostVethName, contVeth, err = makeVeth(contVethName, mtu)
+func SetupVeth(contVethName string, mtu int, hostNS ns.NetNS) (Link, Link, error) {
+	hostVethName, contVeth, err := makeVeth(contVethName, mtu)
 	if err != nil {
-		return
+		return nil, nil, err
 	}
 
 	if err = netlink.LinkSetUp(contVeth); err != nil {
-		err = fmt.Errorf("failed to set %q up: %v", contVethName, err)
-		return
+		return nil, nil, fmt.Errorf("failed to set %q up: %v", contVethName, err)
 	}
 
-	hostVeth, err = netlink.LinkByName(hostVethName)
+	hostVeth, err := netlink.LinkByName(hostVethName)
 	if err != nil {
-		err = fmt.Errorf("failed to lookup %q: %v", hostVethName, err)
-		return
+		return nil, nil, fmt.Errorf("failed to lookup %q: %v", hostVethName, err)
 	}
 
 	if err = netlink.LinkSetNsFd(hostVeth, int(hostNS.Fd())); err != nil {
-		err = fmt.Errorf("failed to move veth to host netns: %v", err)
-		return
+		return nil, nil, fmt.Errorf("failed to move veth to host netns: %v", err)
 	}
 
 	err = hostNS.Do(func(_ ns.NetNS) error {
@@ -135,7 +154,10 @@ func SetupVeth(contVethName string, mtu int, hostNS ns.NetNS) (hostVeth, contVet
 		}
 		return nil
 	})
-	return
+	if err != nil {
+		return nil, nil, err
+	}
+	return &link{hostVeth}, &link{contVeth}, nil
 }
 
 // DelLinkByName removes an interface link.
diff --git a/pkg/ip/link_test.go b/pkg/ip/link_test.go
index 3df9ab8f..2c9ae400 100644
--- a/pkg/ip/link_test.go
+++ b/pkg/ip/link_test.go
@@ -46,8 +46,8 @@ var _ = Describe("Link", func() {
 		hostNetNS         ns.NetNS
 		containerNetNS    ns.NetNS
 		ifaceCounter      int = 0
-		hostVeth          netlink.Link
-		containerVeth     netlink.Link
+		hostVeth          ip.Link
+		containerVeth     ip.Link
 		hostVethName      string
 		containerVethName string
 
diff --git a/plugins/main/ptp/ptp.go b/plugins/main/ptp/ptp.go
index 87e86a59..3e88515c 100644
--- a/plugins/main/ptp/ptp.go
+++ b/plugins/main/ptp/ptp.go
@@ -63,14 +63,14 @@ func setupContainerVeth(netns ns.NetNS, ifName string, mtu int, pr *current.Resu
 	containerInterface := &current.Interface{}
 
 	err := netns.Do(func(hostNS ns.NetNS) error {
-		hostVeth, contVeth, err := ip.SetupVeth(ifName, mtu, hostNS)
+		hostVeth, contVeth0, err := ip.SetupVeth(ifName, mtu, hostNS)
 		if err != nil {
 			return err
 		}
 		hostInterface.Name = hostVeth.Attrs().Name
 		hostInterface.Mac = hostVeth.Attrs().HardwareAddr.String()
-		containerInterface.Name = contVeth.Attrs().Name
-		containerInterface.Mac = contVeth.Attrs().HardwareAddr.String()
+		containerInterface.Name = contVeth0.Attrs().Name
+		containerInterface.Mac = contVeth0.Attrs().HardwareAddr.String()
 		containerInterface.Sandbox = netns.Path()
 
 		var firstV4Addr net.IP
@@ -103,12 +103,12 @@ func setupContainerVeth(netns ns.NetNS, ifName string, mtu int, pr *current.Resu
 			return err
 		}
 
-		if err := ip.SetHWAddrByIP(contVeth.Attrs().Name, firstV4Addr, nil /* TODO IPv6 */); err != nil {
+		if err := ip.SetHWAddrByIP(contVeth0.Attrs().Name, firstV4Addr, nil /* TODO IPv6 */); err != nil {
 			return fmt.Errorf("failed to set hardware addr by IP: %v", err)
 		}
 
 		// Re-fetch container veth to update attributes
-		contVeth, err = netlink.LinkByName(ifName)
+		contVeth, err := netlink.LinkByName(ifName)
 		if err != nil {
 			return fmt.Errorf("failed to look up %q: %v", ifName, err)
 		}