ITQC/containernetworking-plugins
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Do not use netns as ID or for entropy

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ContainerID is now required so use that
or generate random bytes.

Fixes #5
This commit is contained in:
Eugene Yakubovich 2015-05-05 13:35:20 -07:00
parent c24708ff62
commit 93be8e63f1
1 changed files with 51 additions and 23 deletions
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74
ip/link.go
View File

@ -15,7 +15,7 @@
package ip
import (
"crypto/sha512"
"crypto/rand"
"fmt"
"net"
"os"
@ -23,7 +23,7 @@ import (
"github.com/appc/cni/Godeps/_workspace/src/github.com/vishvananda/netlink"
)
func makeVeth(name, peer string, mtu int) (netlink.Link, error) {
func makeVethPair(name, peer string, mtu int) (netlink.Link, error) {
veth := &netlink.Veth{
LinkAttrs: netlink.LinkAttrs{
Name: name,
@ -39,33 +39,50 @@ func makeVeth(name, peer string, mtu int) (netlink.Link, error) {
return veth, nil
}
func makeVeth(name string, mtu int) (peerName string, veth netlink.Link, err error) {
for i := 0; i < 10; i++ {
peerName, err = RandomVethName()
if err != nil {
return
}
veth, err = makeVethPair(name, peerName, mtu)
switch {
case err == nil:
return
case os.IsExist(err):
continue
default:
err = fmt.Errorf("failed to make veth pair: %v", err)
return
}
}
// should really never be hit
err = fmt.Errorf("failed to find a unique veth name")
return
}
// RandomVethName returns string "veth" with random prefix (hashed from entropy)
func RandomVethName(entropy string) string {
h := sha512.New()
h.Write([]byte(entropy))
return fmt.Sprintf("veth%x", h.Sum(nil)[:5])
func RandomVethName() (string, error) {
entropy := make([]byte, 4)
_, err := rand.Reader.Read(entropy)
if err != nil {
return "", fmt.Errorf("failed to generate random veth name: %v", err)
}
// NetworkManager (recent versions) will ignore veth devices that start with "veth"
return fmt.Sprintf("veth%x", entropy), nil
}
// 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, mtu int, hostNS *os.File) (hostVeth, contVeth netlink.Link, err error) {
// NetworkManager (recent versions) will ignore veth devices that start with "veth"
hostVethName := RandomVethName(entropy)
hostVeth, err = makeVeth(hostVethName, contVethName, mtu)
func SetupVeth(contVethName string, mtu int, hostNS *os.File) (hostVeth, contVeth netlink.Link, err error) {
var hostVethName string
hostVethName, contVeth, err = makeVeth(contVethName, mtu)
if err != nil {
err = fmt.Errorf("failed to make veth pair: %v", err)
return
}
if err = netlink.LinkSetUp(hostVeth); err != nil {
err = fmt.Errorf("failed to set %q up: %v", hostVethName, err)
return
}
contVeth, err = netlink.LinkByName(contVethName)
if err != nil {
err = fmt.Errorf("failed to lookup %q: %v", contVethName, err)
return
}
@ -74,6 +91,17 @@ func SetupVeth(entropy, contVethName string, mtu int, hostNS *os.File) (hostVeth
return
}
hostVeth, err = netlink.LinkByName(hostVethName)
if err != nil {
err = fmt.Errorf("failed to lookup %q: %v", hostVethName, err)
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