vendor: re-vendor

vendor/github.com/containernetworking/plugins/pkg/ip/addr.go

@@ -0,0 +1,68 @@
+// Copyright 2017 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ip
+
+import (
+	"fmt"
+	"syscall"
+	"time"
+
+	"github.com/vishvananda/netlink"
+)
+
+const SETTLE_INTERVAL = 50 * time.Millisecond
+
+// SettleAddresses waits for all addresses on a link to leave tentative state.
+// This is particularly useful for ipv6, where all addresses need to do DAD.
+// There is no easy way to wait for this as an event, so just loop until the
+// addresses are no longer tentative.
+// If any addresses are still tentative after timeout seconds, then error.
+func SettleAddresses(ifName string, timeout int) error {
+	link, err := netlink.LinkByName(ifName)
+	if err != nil {
+		return fmt.Errorf("failed to retrieve link: %v", err)
+	}
+
+	deadline := time.Now().Add(time.Duration(timeout) * time.Second)
+	for {
+		addrs, err := netlink.AddrList(link, netlink.FAMILY_ALL)
+		if err != nil {
+			return fmt.Errorf("could not list addresses: %v", err)
+		}
+
+		if len(addrs) == 0 {
+			return nil
+		}
+
+		ok := true
+		for _, addr := range addrs {
+			if addr.Flags&(syscall.IFA_F_TENTATIVE|syscall.IFA_F_DADFAILED) > 0 {
+				ok = false
+				break // Break out of the `range addrs`, not the `for`
+			}
+		}
+
+		if ok {
+			return nil
+		}
+		if time.Now().After(deadline) {
+			return fmt.Errorf("link %s still has tentative addresses after %d seconds",
+				ifName,
+				timeout)
+		}
+
+		time.Sleep(SETTLE_INTERVAL)
+	}
+}

vendor/github.com/containernetworking/plugins/pkg/ip/cidr.go

@@ -0,0 +1,61 @@
+// Copyright 2015 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ip
+
+import (
+	"math/big"
+	"net"
+)
+
+// NextIP returns IP incremented by 1
+func NextIP(ip net.IP) net.IP {
+	i := ipToInt(ip)
+	return intToIP(i.Add(i, big.NewInt(1)))
+}
+
+// PrevIP returns IP decremented by 1
+func PrevIP(ip net.IP) net.IP {
+	i := ipToInt(ip)
+	return intToIP(i.Sub(i, big.NewInt(1)))
+}
+
+// Cmp compares two IPs, returning the usual ordering:
+// a < b : -1
+// a == b : 0
+// a > b : 1
+func Cmp(a, b net.IP) int {
+	aa := ipToInt(a)
+	bb := ipToInt(b)
+	return aa.Cmp(bb)
+}
+
+func ipToInt(ip net.IP) *big.Int {
+	if v := ip.To4(); v != nil {
+		return big.NewInt(0).SetBytes(v)
+	}
+	return big.NewInt(0).SetBytes(ip.To16())
+}
+
+func intToIP(i *big.Int) net.IP {
+	return net.IP(i.Bytes())
+}
+
+// Network masks off the host portion of the IP
+func Network(ipn *net.IPNet) *net.IPNet {
+	return &net.IPNet{
+		IP:   ipn.IP.Mask(ipn.Mask),
+		Mask: ipn.Mask,
+	}
+}

vendor/github.com/containernetworking/plugins/pkg/ip/ipforward.go

@@ -0,0 +1,55 @@
+// Copyright 2015 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ip
+
+import (
+	"io/ioutil"
+
+	"github.com/containernetworking/cni/pkg/types/current"
+)
+
+func EnableIP4Forward() error {
+	return echo1("/proc/sys/net/ipv4/ip_forward")
+}
+
+func EnableIP6Forward() error {
+	return echo1("/proc/sys/net/ipv6/conf/all/forwarding")
+}
+
+// EnableForward will enable forwarding for all configured
+// address families
+func EnableForward(ips []*current.IPConfig) error {
+	v4 := false
+	v6 := false
+
+	for _, ip := range ips {
+		if ip.Version == "4" && !v4 {
+			if err := EnableIP4Forward(); err != nil {
+				return err
+			}
+			v4 = true
+		} else if ip.Version == "6" && !v6 {
+			if err := EnableIP6Forward(); err != nil {
+				return err
+			}
+			v6 = true
+		}
+	}
+	return nil
+}
+
+func echo1(f string) error {
+	return ioutil.WriteFile(f, []byte("1"), 0644)
+}

vendor/github.com/containernetworking/plugins/pkg/ip/ipmasq.go

@@ -0,0 +1,92 @@
+// Copyright 2015 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ip
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/coreos/go-iptables/iptables"
+)
+
+// SetupIPMasq installs iptables rules to masquerade traffic
+// coming from ipn and going outside of it
+func SetupIPMasq(ipn *net.IPNet, chain string, comment string) error {
+	isV6 := ipn.IP.To4() == nil
+
+	var ipt *iptables.IPTables
+	var err error
+	var multicastNet string
+
+	if isV6 {
+		ipt, err = iptables.NewWithProtocol(iptables.ProtocolIPv6)
+		multicastNet = "ff00::/8"
+	} else {
+		ipt, err = iptables.NewWithProtocol(iptables.ProtocolIPv4)
+		multicastNet = "224.0.0.0/4"
+	}
+	if err != nil {
+		return fmt.Errorf("failed to locate iptables: %v", err)
+	}
+
+	// Create chain if doesn't exist
+	exists := false
+	chains, err := ipt.ListChains("nat")
+	if err != nil {
+		return fmt.Errorf("failed to list chains: %v", err)
+	}
+	for _, ch := range chains {
+		if ch == chain {
+			exists = true
+			break
+		}
+	}
+	if !exists {
+		if err = ipt.NewChain("nat", chain); err != nil {
+			return err
+		}
+	}
+
+	// Packets to this network should not be touched
+	if err := ipt.AppendUnique("nat", chain, "-d", ipn.String(), "-j", "ACCEPT", "-m", "comment", "--comment", comment); err != nil {
+		return err
+	}
+
+	// Don't masquerade multicast - pods should be able to talk to other pods
+	// on the local network via multicast.
+	if err := ipt.AppendUnique("nat", chain, "!", "-d", multicastNet, "-j", "MASQUERADE", "-m", "comment", "--comment", comment); err != nil {
+		return err
+	}
+
+	return ipt.AppendUnique("nat", "POSTROUTING", "-s", ipn.String(), "-j", chain, "-m", "comment", "--comment", comment)
+}
+
+// TeardownIPMasq undoes the effects of SetupIPMasq
+func TeardownIPMasq(ipn *net.IPNet, chain string, comment string) error {
+	ipt, err := iptables.New()
+	if err != nil {
+		return fmt.Errorf("failed to locate iptables: %v", err)
+	}
+
+	if err = ipt.Delete("nat", "POSTROUTING", "-s", ipn.String(), "-j", chain, "-m", "comment", "--comment", comment); err != nil {
+		return err
+	}
+
+	if err = ipt.ClearChain("nat", chain); err != nil {
+		return err
+	}
+
+	return ipt.DeleteChain("nat", chain)
+}

vendor/github.com/containernetworking/plugins/pkg/ip/link.go

@@ -0,0 +1,219 @@
+// Copyright 2015 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ip
+
+import (
+	"crypto/rand"
+	"errors"
+	"fmt"
+	"net"
+	"os"
+
+	"github.com/containernetworking/plugins/pkg/ns"
+	"github.com/containernetworking/plugins/pkg/utils/hwaddr"
+	"github.com/vishvananda/netlink"
+)
+
+var (
+	ErrLinkNotFound = errors.New("link not found")
+)
+
+func makeVethPair(name, peer string, mtu int) (netlink.Link, error) {
+	veth := &netlink.Veth{
+		LinkAttrs: netlink.LinkAttrs{
+			Name:  name,
+			Flags: net.FlagUp,
+			MTU:   mtu,
+		},
+		PeerName: peer,
+	}
+	if err := netlink.LinkAdd(veth); err != nil {
+		return nil, err
+	}
+
+	return veth, nil
+}
+
+func peerExists(name string) bool {
+	if _, err := netlink.LinkByName(name); err != nil {
+		return false
+	}
+	return true
+}
+
+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):
+			if peerExists(peerName) {
+				continue
+			}
+			err = fmt.Errorf("container veth name provided (%v) already exists", name)
+			return
+
+		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() (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
+}
+
+func RenameLink(curName, newName string) error {
+	link, err := netlink.LinkByName(curName)
+	if err == nil {
+		err = netlink.LinkSetName(link, newName)
+	}
+	return err
+}
+
+func ifaceFromNetlinkLink(l netlink.Link) net.Interface {
+	a := l.Attrs()
+	return net.Interface{
+		Index:        a.Index,
+		MTU:          a.MTU,
+		Name:         a.Name,
+		HardwareAddr: a.HardwareAddr,
+		Flags:        a.Flags,
+	}
+}
+
+// SetupVeth sets up a pair of virtual ethernet devices.
+// Call SetupVeth from inside the container netns.  It will create both veth
+// devices and move the host-side veth into the provided hostNS namespace.
+// On success, SetupVeth returns (hostVeth, containerVeth, nil)
+func SetupVeth(contVethName string, mtu int, hostNS ns.NetNS) (net.Interface, net.Interface, error) {
+	hostVethName, contVeth, err := makeVeth(contVethName, mtu)
+	if err != nil {
+		return net.Interface{}, net.Interface{}, err
+	}
+
+	if err = netlink.LinkSetUp(contVeth); err != nil {
+		return net.Interface{}, net.Interface{}, fmt.Errorf("failed to set %q up: %v", contVethName, err)
+	}
+
+	hostVeth, err := netlink.LinkByName(hostVethName)
+	if err != nil {
+		return net.Interface{}, net.Interface{}, fmt.Errorf("failed to lookup %q: %v", hostVethName, err)
+	}
+
+	if err = netlink.LinkSetNsFd(hostVeth, int(hostNS.Fd())); err != nil {
+		return net.Interface{}, net.Interface{}, fmt.Errorf("failed to move veth to host netns: %v", err)
+	}
+
+	err = hostNS.Do(func(_ ns.NetNS) error {
+		hostVeth, err = netlink.LinkByName(hostVethName)
+		if err != nil {
+			return fmt.Errorf("failed to lookup %q in %q: %v", hostVethName, hostNS.Path(), err)
+		}
+
+		if err = netlink.LinkSetUp(hostVeth); err != nil {
+			return fmt.Errorf("failed to set %q up: %v", hostVethName, err)
+		}
+		return nil
+	})
+	if err != nil {
+		return net.Interface{}, net.Interface{}, err
+	}
+	return ifaceFromNetlinkLink(hostVeth), ifaceFromNetlinkLink(contVeth), nil
+}
+
+// DelLinkByName removes an interface link.
+func DelLinkByName(ifName string) error {
+	iface, err := netlink.LinkByName(ifName)
+	if err != nil {
+		return fmt.Errorf("failed to lookup %q: %v", ifName, err)
+	}
+
+	if err = netlink.LinkDel(iface); err != nil {
+		return fmt.Errorf("failed to delete %q: %v", ifName, err)
+	}
+
+	return nil
+}
+
+// DelLinkByNameAddr remove an interface returns its IP address
+// of the specified family
+func DelLinkByNameAddr(ifName string, family int) (*net.IPNet, error) {
+	iface, err := netlink.LinkByName(ifName)
+	if err != nil {
+		if err != nil && err.Error() == "Link not found" {
+			return nil, ErrLinkNotFound
+		}
+		return nil, fmt.Errorf("failed to lookup %q: %v", ifName, err)
+	}
+
+	addrs, err := netlink.AddrList(iface, family)
+	if err != nil || len(addrs) == 0 {
+		return nil, fmt.Errorf("failed to get IP addresses for %q: %v", ifName, err)
+	}
+
+	if err = netlink.LinkDel(iface); err != nil {
+		return nil, fmt.Errorf("failed to delete %q: %v", ifName, err)
+	}
+
+	return addrs[0].IPNet, nil
+}
+
+func SetHWAddrByIP(ifName string, ip4 net.IP, ip6 net.IP) error {
+	iface, err := netlink.LinkByName(ifName)
+	if err != nil {
+		return fmt.Errorf("failed to lookup %q: %v", ifName, err)
+	}
+
+	switch {
+	case ip4 == nil && ip6 == nil:
+		return fmt.Errorf("neither ip4 or ip6 specified")
+
+	case ip4 != nil:
+		{
+			hwAddr, err := hwaddr.GenerateHardwareAddr4(ip4, hwaddr.PrivateMACPrefix)
+			if err != nil {
+				return fmt.Errorf("failed to generate hardware addr: %v", err)
+			}
+			if err = netlink.LinkSetHardwareAddr(iface, hwAddr); err != nil {
+				return fmt.Errorf("failed to add hardware addr to %q: %v", ifName, err)
+			}
+		}
+	case ip6 != nil:
+		// TODO: IPv6
+	}
+
+	return nil
+}

vendor/github.com/containernetworking/plugins/pkg/ip/route.go

@@ -0,0 +1,27 @@
+// Copyright 2015 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ip
+
+import (
+	"net"
+
+	"github.com/vishvananda/netlink"
+)
+
+// AddDefaultRoute sets the default route on the given gateway.
+func AddDefaultRoute(gw net.IP, dev netlink.Link) error {
+	_, defNet, _ := net.ParseCIDR("0.0.0.0/0")
+	return AddRoute(defNet, gw, dev)
+}

vendor/github.com/containernetworking/plugins/pkg/ip/route_linux.go

@@ -0,0 +1,41 @@
+// Copyright 2015-2017 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ip
+
+import (
+	"net"
+
+	"github.com/vishvananda/netlink"
+)
+
+// AddRoute adds a universally-scoped route to a device.
+func AddRoute(ipn *net.IPNet, gw net.IP, dev netlink.Link) error {
+	return netlink.RouteAdd(&netlink.Route{
+		LinkIndex: dev.Attrs().Index,
+		Scope:     netlink.SCOPE_UNIVERSE,
+		Dst:       ipn,
+		Gw:        gw,
+	})
+}
+
+// AddHostRoute adds a host-scoped route to a device.
+func AddHostRoute(ipn *net.IPNet, gw net.IP, dev netlink.Link) error {
+	return netlink.RouteAdd(&netlink.Route{
+		LinkIndex: dev.Attrs().Index,
+		Scope:     netlink.SCOPE_HOST,
+		Dst:       ipn,
+		Gw:        gw,
+	})
+}

vendor/github.com/containernetworking/plugins/pkg/ip/route_unspecified.go

@@ -0,0 +1,34 @@
+// Copyright 2015-2017 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !linux
+
+package ip
+
+import (
+	"net"
+
+	"github.com/containernetworking/cni/pkg/types"
+	"github.com/vishvananda/netlink"
+)
+
+// AddRoute adds a universally-scoped route to a device.
+func AddRoute(ipn *net.IPNet, gw net.IP, dev netlink.Link) error {
+	return types.NotImplementedError
+}
+
+// AddHostRoute adds a host-scoped route to a device.
+func AddHostRoute(ipn *net.IPNet, gw net.IP, dev netlink.Link) error {
+	return types.NotImplementedError
+}

vendor/github.com/containernetworking/plugins/pkg/ns/README.md

@@ -0,0 +1,40 @@
+### Namespaces, Threads, and Go
+On Linux each OS thread can have a different network namespace.  Go's thread scheduling model switches goroutines between OS threads based on OS thread load and whether the goroutine would block other goroutines.  This can result in a goroutine switching network namespaces without notice and lead to errors in your code.
+
+### Namespace Switching
+Switching namespaces with the `ns.Set()` method is not recommended without additional strategies to prevent unexpected namespace changes when your goroutines switch OS threads.
+
+Go provides the `runtime.LockOSThread()` function to ensure a specific goroutine executes on its current OS thread and prevents any other goroutine from running in that thread until the locked one exits.  Careful usage of `LockOSThread()` and goroutines can provide good control over which network namespace a given goroutine executes in.
+
+For example, you cannot rely on the `ns.Set()` namespace being the current namespace after the `Set()` call unless you do two things.  First, the goroutine calling `Set()` must have previously called `LockOSThread()`.  Second, you must ensure `runtime.UnlockOSThread()` is not called somewhere in-between.  You also cannot rely on the initial network namespace remaining the current network namespace if any other code in your program switches namespaces, unless you have already called `LockOSThread()` in that goroutine.  Note that `LockOSThread()` prevents the Go scheduler from optimally scheduling goroutines for best performance, so `LockOSThread()` should only be used in small, isolated goroutines that release the lock quickly.
+
+### Do() The Recommended Thing
+The `ns.Do()` method provides **partial** control over network namespaces for you by implementing these strategies. All code dependent on a particular network namespace (including the root namespace) should be wrapped in the `ns.Do()` method to ensure the correct namespace is selected for the duration of your code.  For example:
+
+```go
+targetNs, err := ns.NewNS()
+if err != nil {
+    return err
+}
+err = targetNs.Do(func(hostNs ns.NetNS) error {
+	dummy := &netlink.Dummy{
+		LinkAttrs: netlink.LinkAttrs{
+			Name: "dummy0",
+		},
+	}
+	return netlink.LinkAdd(dummy)
+})
+```
+
+Note this requirement to wrap every network call is very onerous - any libraries you call might call out to network services such as DNS, and all such calls need to be protected after you call `ns.Do()`. The CNI plugins all exit very soon after calling `ns.Do()` which helps to minimize the problem.
+
+Also:  If the runtime spawns a new OS thread, it will inherit the network namespace of the parent thread, which may have been temporarily switched, and thus the new OS thread will be permanently "stuck in the wrong namespace".
+
+In short, **there is no safe way to change network namespaces from within a long-lived, multithreaded Go process**.  If your daemon process needs to be namespace aware, consider spawning a separate process (like a CNI plugin) for each namespace.
+
+### Further Reading
+ - https://github.com/golang/go/wiki/LockOSThread
+ - http://morsmachine.dk/go-scheduler
+ - https://github.com/containernetworking/cni/issues/262
+ - https://golang.org/pkg/runtime/
+ - https://www.weave.works/blog/linux-namespaces-and-go-don-t-mix

vendor/github.com/containernetworking/plugins/pkg/ns/ns.go

@@ -0,0 +1,178 @@
+// Copyright 2015 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ns
+
+import (
+	"fmt"
+	"os"
+	"runtime"
+	"sync"
+	"syscall"
+)
+
+type NetNS interface {
+	// Executes the passed closure in this object's network namespace,
+	// attempting to restore the original namespace before returning.
+	// However, since each OS thread can have a different network namespace,
+	// and Go's thread scheduling is highly variable, callers cannot
+	// guarantee any specific namespace is set unless operations that
+	// require that namespace are wrapped with Do().  Also, no code called
+	// from Do() should call runtime.UnlockOSThread(), or the risk
+	// of executing code in an incorrect namespace will be greater.  See
+	// https://github.com/golang/go/wiki/LockOSThread for further details.
+	Do(toRun func(NetNS) error) error
+
+	// Sets the current network namespace to this object's network namespace.
+	// Note that since Go's thread scheduling is highly variable, callers
+	// cannot guarantee the requested namespace will be the current namespace
+	// after this function is called; to ensure this wrap operations that
+	// require the namespace with Do() instead.
+	Set() error
+
+	// Returns the filesystem path representing this object's network namespace
+	Path() string
+
+	// Returns a file descriptor representing this object's network namespace
+	Fd() uintptr
+
+	// Cleans up this instance of the network namespace; if this instance
+	// is the last user the namespace will be destroyed
+	Close() error
+}
+
+type netNS struct {
+	file    *os.File
+	mounted bool
+	closed  bool
+}
+
+// netNS implements the NetNS interface
+var _ NetNS = &netNS{}
+
+const (
+	// https://github.com/torvalds/linux/blob/master/include/uapi/linux/magic.h
+	NSFS_MAGIC   = 0x6e736673
+	PROCFS_MAGIC = 0x9fa0
+)
+
+type NSPathNotExistErr struct{ msg string }
+
+func (e NSPathNotExistErr) Error() string { return e.msg }
+
+type NSPathNotNSErr struct{ msg string }
+
+func (e NSPathNotNSErr) Error() string { return e.msg }
+
+func IsNSorErr(nspath string) error {
+	stat := syscall.Statfs_t{}
+	if err := syscall.Statfs(nspath, &stat); err != nil {
+		if os.IsNotExist(err) {
+			err = NSPathNotExistErr{msg: fmt.Sprintf("failed to Statfs %q: %v", nspath, err)}
+		} else {
+			err = fmt.Errorf("failed to Statfs %q: %v", nspath, err)
+		}
+		return err
+	}
+
+	switch stat.Type {
+	case PROCFS_MAGIC, NSFS_MAGIC:
+		return nil
+	default:
+		return NSPathNotNSErr{msg: fmt.Sprintf("unknown FS magic on %q: %x", nspath, stat.Type)}
+	}
+}
+
+// Returns an object representing the namespace referred to by @path
+func GetNS(nspath string) (NetNS, error) {
+	err := IsNSorErr(nspath)
+	if err != nil {
+		return nil, err
+	}
+
+	fd, err := os.Open(nspath)
+	if err != nil {
+		return nil, err
+	}
+
+	return &netNS{file: fd}, nil
+}
+
+func (ns *netNS) Path() string {
+	return ns.file.Name()
+}
+
+func (ns *netNS) Fd() uintptr {
+	return ns.file.Fd()
+}
+
+func (ns *netNS) errorIfClosed() error {
+	if ns.closed {
+		return fmt.Errorf("%q has already been closed", ns.file.Name())
+	}
+	return nil
+}
+
+func (ns *netNS) Do(toRun func(NetNS) error) error {
+	if err := ns.errorIfClosed(); err != nil {
+		return err
+	}
+
+	containedCall := func(hostNS NetNS) error {
+		threadNS, err := GetCurrentNS()
+		if err != nil {
+			return fmt.Errorf("failed to open current netns: %v", err)
+		}
+		defer threadNS.Close()
+
+		// switch to target namespace
+		if err = ns.Set(); err != nil {
+			return fmt.Errorf("error switching to ns %v: %v", ns.file.Name(), err)
+		}
+		defer threadNS.Set() // switch back
+
+		return toRun(hostNS)
+	}
+
+	// save a handle to current network namespace
+	hostNS, err := GetCurrentNS()
+	if err != nil {
+		return fmt.Errorf("Failed to open current namespace: %v", err)
+	}
+	defer hostNS.Close()
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+
+	var innerError error
+	go func() {
+		defer wg.Done()
+		runtime.LockOSThread()
+		innerError = containedCall(hostNS)
+	}()
+	wg.Wait()
+
+	return innerError
+}
+
+// WithNetNSPath executes the passed closure under the given network
+// namespace, restoring the original namespace afterwards.
+func WithNetNSPath(nspath string, toRun func(NetNS) error) error {
+	ns, err := GetNS(nspath)
+	if err != nil {
+		return err
+	}
+	defer ns.Close()
+	return ns.Do(toRun)
+}

vendor/github.com/containernetworking/plugins/pkg/ns/ns_linux.go

@@ -0,0 +1,149 @@
+// Copyright 2015-2017 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ns
+
+import (
+	"crypto/rand"
+	"fmt"
+	"os"
+	"path"
+	"runtime"
+	"sync"
+
+	"golang.org/x/sys/unix"
+)
+
+// Returns an object representing the current OS thread's network namespace
+func GetCurrentNS() (NetNS, error) {
+	return GetNS(getCurrentThreadNetNSPath())
+}
+
+func getCurrentThreadNetNSPath() string {
+	// /proc/self/ns/net returns the namespace of the main thread, not
+	// of whatever thread this goroutine is running on.  Make sure we
+	// use the thread's net namespace since the thread is switching around
+	return fmt.Sprintf("/proc/%d/task/%d/ns/net", os.Getpid(), unix.Gettid())
+}
+
+// Creates a new persistent network namespace and returns an object
+// representing that namespace, without switching to it
+func NewNS() (NetNS, error) {
+	const nsRunDir = "/var/run/netns"
+
+	b := make([]byte, 16)
+	_, err := rand.Reader.Read(b)
+	if err != nil {
+		return nil, fmt.Errorf("failed to generate random netns name: %v", err)
+	}
+
+	err = os.MkdirAll(nsRunDir, 0755)
+	if err != nil {
+		return nil, err
+	}
+
+	// create an empty file at the mount point
+	nsName := fmt.Sprintf("cni-%x-%x-%x-%x-%x", b[0:4], b[4:6], b[6:8], b[8:10], b[10:])
+	nsPath := path.Join(nsRunDir, nsName)
+	mountPointFd, err := os.Create(nsPath)
+	if err != nil {
+		return nil, err
+	}
+	mountPointFd.Close()
+
+	// Ensure the mount point is cleaned up on errors; if the namespace
+	// was successfully mounted this will have no effect because the file
+	// is in-use
+	defer os.RemoveAll(nsPath)
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+
+	// do namespace work in a dedicated goroutine, so that we can safely
+	// Lock/Unlock OSThread without upsetting the lock/unlock state of
+	// the caller of this function
+	var fd *os.File
+	go (func() {
+		defer wg.Done()
+		runtime.LockOSThread()
+
+		var origNS NetNS
+		origNS, err = GetNS(getCurrentThreadNetNSPath())
+		if err != nil {
+			return
+		}
+		defer origNS.Close()
+
+		// create a new netns on the current thread
+		err = unix.Unshare(unix.CLONE_NEWNET)
+		if err != nil {
+			return
+		}
+		defer origNS.Set()
+
+		// bind mount the new netns from the current thread onto the mount point
+		err = unix.Mount(getCurrentThreadNetNSPath(), nsPath, "none", unix.MS_BIND, "")
+		if err != nil {
+			return
+		}
+
+		fd, err = os.Open(nsPath)
+		if err != nil {
+			return
+		}
+	})()
+	wg.Wait()
+
+	if err != nil {
+		unix.Unmount(nsPath, unix.MNT_DETACH)
+		return nil, fmt.Errorf("failed to create namespace: %v", err)
+	}
+
+	return &netNS{file: fd, mounted: true}, nil
+}
+
+func (ns *netNS) Close() error {
+	if err := ns.errorIfClosed(); err != nil {
+		return err
+	}
+
+	if err := ns.file.Close(); err != nil {
+		return fmt.Errorf("Failed to close %q: %v", ns.file.Name(), err)
+	}
+	ns.closed = true
+
+	if ns.mounted {
+		if err := unix.Unmount(ns.file.Name(), unix.MNT_DETACH); err != nil {
+			return fmt.Errorf("Failed to unmount namespace %s: %v", ns.file.Name(), err)
+		}
+		if err := os.RemoveAll(ns.file.Name()); err != nil {
+			return fmt.Errorf("Failed to clean up namespace %s: %v", ns.file.Name(), err)
+		}
+		ns.mounted = false
+	}
+
+	return nil
+}
+
+func (ns *netNS) Set() error {
+	if err := ns.errorIfClosed(); err != nil {
+		return err
+	}
+
+	if err := unix.Setns(int(ns.Fd()), unix.CLONE_NEWNET); err != nil {
+		return fmt.Errorf("Error switching to ns %v: %v", ns.file.Name(), err)
+	}
+
+	return nil
+}

vendor/github.com/containernetworking/plugins/pkg/ns/ns_unspecified.go

@@ -0,0 +1,36 @@
+// Copyright 2015-2017 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !linux
+
+package ns
+
+import "github.com/containernetworking/cni/pkg/types"
+
+// Returns an object representing the current OS thread's network namespace
+func GetCurrentNS() (NetNS, error) {
+	return nil, types.NotImplementedError
+}
+
+func NewNS() (NetNS, error) {
+	return nil, types.NotImplementedError
+}
+
+func (ns *netNS) Close() error {
+	return types.NotImplementedError
+}
+
+func (ns *netNS) Set() error {
+	return types.NotImplementedError
+}

vendor/github.com/containernetworking/plugins/pkg/utils/hwaddr/hwaddr.go

@@ -0,0 +1,63 @@
+// Copyright 2016 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package hwaddr
+
+import (
+	"fmt"
+	"net"
+)
+
+const (
+	ipRelevantByteLen      = 4
+	PrivateMACPrefixString = "0a:58"
+)
+
+var (
+	// private mac prefix safe to use
+	PrivateMACPrefix = []byte{0x0a, 0x58}
+)
+
+type SupportIp4OnlyErr struct{ msg string }
+
+func (e SupportIp4OnlyErr) Error() string { return e.msg }
+
+type MacParseErr struct{ msg string }
+
+func (e MacParseErr) Error() string { return e.msg }
+
+type InvalidPrefixLengthErr struct{ msg string }
+
+func (e InvalidPrefixLengthErr) Error() string { return e.msg }
+
+// GenerateHardwareAddr4 generates 48 bit virtual mac addresses based on the IP4 input.
+func GenerateHardwareAddr4(ip net.IP, prefix []byte) (net.HardwareAddr, error) {
+	switch {
+
+	case ip.To4() == nil:
+		return nil, SupportIp4OnlyErr{msg: "GenerateHardwareAddr4 only supports valid IPv4 address as input"}
+
+	case len(prefix) != len(PrivateMACPrefix):
+		return nil, InvalidPrefixLengthErr{msg: fmt.Sprintf(
+			"Prefix has length %d instead  of %d", len(prefix), len(PrivateMACPrefix)),
+		}
+	}
+
+	ipByteLen := len(ip)
+	return (net.HardwareAddr)(
+		append(
+			prefix,
+			ip[ipByteLen-ipRelevantByteLen:ipByteLen]...),
+	), nil
+}