From: Stefan Junker <mail@stefanjunker.de>
Date: Wed, 23 Sep 2015 09:03:22 +0000 (+0200)
Subject: plugins/ptp: allow host veth to be UP
X-Git-Url: https://git.halfball.org/?a=commitdiff_plain;h=8d3eb91a374b7b66479404be4acd9b56ab4f93eb;p=plugins.git

plugins/ptp: allow host veth to be UP
---

diff --git a/ip/link.go b/ip/link.go
index 3936ed9..e97dcd2 100644
--- a/ip/link.go
+++ b/ip/link.go
@@ -77,8 +77,9 @@ func RandomVethName() (string, error) {
 	return fmt.Sprintf("veth%x", entropy), nil
 }
 
-// SetupVeth sets up a virtual ethernet link.
-// Should be in container netns.
+// SetupVeth creates the virtual ethernet pair and sets up the container's end in the container netns.
+// Setting up the host end up has to be done in the host netns outside of this function.
+// This is because moving the host veth end will cause it to be brought down automatically when it is moved to the host netns.
 func SetupVeth(contVethName string, mtu int, hostNS *os.File) (hostVeth, contVeth netlink.Link, err error) {
 	var hostVethName string
 	hostVethName, contVeth, err = makeVeth(contVethName, mtu)
@@ -97,11 +98,6 @@ func SetupVeth(contVethName string, mtu int, hostNS *os.File) (hostVeth, contVet
 		return
 	}
 
-	if err = netlink.LinkSetUp(hostVeth); err != nil {
-		err = fmt.Errorf("failed to set %q up: %v", contVethName, 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