Initial commit of libcontainer

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)

libcontainer/network/network.go

@@ -0,0 +1,104 @@
+package network
+
+import (
+	"errors"
+	"github.com/dotcloud/docker/pkg/netlink"
+	"net"
+)
+
+var (
+	ErrNoDefaultRoute = errors.New("no default network route found")
+)
+
+func InterfaceUp(name string) error {
+	iface, err := net.InterfaceByName(name)
+	if err != nil {
+		return err
+	}
+	return netlink.NetworkLinkUp(iface)
+}
+
+func InterfaceDown(name string) error {
+	iface, err := net.InterfaceByName(name)
+	if err != nil {
+		return err
+	}
+	return netlink.NetworkLinkDown(iface)
+}
+
+func ChangeInterfaceName(old, newName string) error {
+	iface, err := net.InterfaceByName(old)
+	if err != nil {
+		return err
+	}
+	return netlink.NetworkChangeName(iface, newName)
+}
+
+func CreateVethPair(name1, name2 string) error {
+	return netlink.NetworkCreateVethPair(name1, name2)
+}
+
+func SetInterfaceInNamespacePid(name string, nsPid int) error {
+	iface, err := net.InterfaceByName(name)
+	if err != nil {
+		return err
+	}
+	return netlink.NetworkSetNsPid(iface, nsPid)
+}
+
+func SetInterfaceInNamespaceFd(name string, fd int) error {
+	iface, err := net.InterfaceByName(name)
+	if err != nil {
+		return err
+	}
+	return netlink.NetworkSetNsFd(iface, fd)
+}
+
+func SetInterfaceMaster(name, master string) error {
+	iface, err := net.InterfaceByName(name)
+	if err != nil {
+		return err
+	}
+	masterIface, err := net.InterfaceByName(master)
+	if err != nil {
+		return err
+	}
+	return netlink.NetworkSetMaster(iface, masterIface)
+}
+
+func SetDefaultGateway(ip string) error {
+	return netlink.AddDefaultGw(net.ParseIP(ip))
+}
+
+func SetInterfaceIp(name string, rawIp string) error {
+	iface, err := net.InterfaceByName(name)
+	if err != nil {
+		return err
+	}
+	ip, ipNet, err := net.ParseCIDR(rawIp)
+	if err != nil {
+		return err
+	}
+	return netlink.NetworkLinkAddIp(iface, ip, ipNet)
+}
+
+func SetMtu(name string, mtu int) error {
+	iface, err := net.InterfaceByName(name)
+	if err != nil {
+		return err
+	}
+	return netlink.NetworkSetMTU(iface, mtu)
+}
+
+func GetDefaultMtu() (int, error) {
+	routes, err := netlink.NetworkGetRoutes()
+	if err != nil {
+		return -1, err
+	}
+	for _, r := range routes {
+		if r.Default {
+			return r.Iface.MTU, nil
+		}
+	}
+	return -1, ErrNoDefaultRoute
+}

libcontainer/network/veth.go

@@ -0,0 +1,85 @@
+package network
+
+import (
+	"fmt"
+	"github.com/dotcloud/docker/pkg/libcontainer"
+	"github.com/dotcloud/docker/pkg/libcontainer/namespaces"
+	"os"
+	"syscall"
+)
+
+// SetupVeth sets up an existing network namespace with the specified
+// network configuration.
+func SetupVeth(config *libcontainer.Network) error {
+	if err := InterfaceDown(config.TempVethName); err != nil {
+		return fmt.Errorf("interface down %s %s", config.TempVethName, err)
+	}
+	if err := ChangeInterfaceName(config.TempVethName, "eth0"); err != nil {
+		return fmt.Errorf("change %s to eth0 %s", config.TempVethName, err)
+	}
+	if err := SetInterfaceIp("eth0", config.IP); err != nil {
+		return fmt.Errorf("set eth0 ip %s", err)
+	}
+
+	if err := SetMtu("eth0", config.Mtu); err != nil {
+		return fmt.Errorf("set eth0 mtu to %d %s", config.Mtu, err)
+	}
+	if err := InterfaceUp("eth0"); err != nil {
+		return fmt.Errorf("eth0 up %s", err)
+	}
+
+	if err := SetMtu("lo", config.Mtu); err != nil {
+		return fmt.Errorf("set lo mtu to %d %s", config.Mtu, err)
+	}
+	if err := InterfaceUp("lo"); err != nil {
+		return fmt.Errorf("lo up %s", err)
+	}
+
+	if config.Gateway != "" {
+		if err := SetDefaultGateway(config.Gateway); err != nil {
+			return fmt.Errorf("set gateway to %s %s", config.Gateway, err)
+		}
+	}
+	return nil
+}
+
+// SetupNamespaceMountDir prepares a new root for use as a mount
+// source for bind mounting namespace fd to an outside path
+func SetupNamespaceMountDir(root string) error {
+	if err := os.MkdirAll(root, 0666); err != nil {
+		return err
+	}
+	// make sure mounts are not unmounted by other mnt namespaces
+	if err := syscall.Mount("", root, "none", syscall.MS_SHARED|syscall.MS_REC, ""); err != nil && err != syscall.EINVAL {
+		return err
+	}
+	if err := syscall.Mount(root, root, "none", syscall.MS_BIND, ""); err != nil {
+		return err
+	}
+	return nil
+}
+
+// CreateNetworkNamespace creates a new network namespace and binds it's fd
+// at the binding path
+func CreateNetworkNamespace(bindingPath string) error {
+	f, err := os.OpenFile(bindingPath, os.O_RDONLY|os.O_CREATE|os.O_EXCL, 0)
+	if err != nil {
+		return err
+	}
+	f.Close()
+
+	if err := namespaces.CreateNewNamespace(libcontainer.CLONE_NEWNET, bindingPath); err != nil {
+		return err
+	}
+	return nil
+}
+
+// DeleteNetworkNamespace unmounts the binding path and removes the
+// file so that no references to the fd are present and the network
+// namespace is automatically cleaned up
+func DeleteNetworkNamespace(bindingPath string) error {
+	if err := syscall.Unmount(bindingPath, 0); err != nil {
+		return err
+	}
+	return os.Remove(bindingPath)
+}