forked from moby/libnetwork
/
interface_linux.go
386 lines (314 loc) · 9.1 KB
/
interface_linux.go
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package osl
import (
"fmt"
"net"
"os/exec"
"regexp"
"sync"
"syscall"
"github.com/docker/libnetwork/types"
"github.com/vishvananda/netlink"
)
// IfaceOption is a function option type to set interface options
type IfaceOption func(i *nwIface)
type nwIface struct {
srcName string
dstName string
master string
dstMaster string
address *net.IPNet
addressIPv6 *net.IPNet
routes []*net.IPNet
bridge bool
ns *networkNamespace
sync.Mutex
}
func (i *nwIface) SrcName() string {
i.Lock()
defer i.Unlock()
return i.srcName
}
func (i *nwIface) DstName() string {
i.Lock()
defer i.Unlock()
return i.dstName
}
func (i *nwIface) DstMaster() string {
i.Lock()
defer i.Unlock()
return i.dstMaster
}
func (i *nwIface) Bridge() bool {
i.Lock()
defer i.Unlock()
return i.bridge
}
func (i *nwIface) Master() string {
i.Lock()
defer i.Unlock()
return i.master
}
func (i *nwIface) Address() *net.IPNet {
i.Lock()
defer i.Unlock()
return types.GetIPNetCopy(i.address)
}
func (i *nwIface) AddressIPv6() *net.IPNet {
i.Lock()
defer i.Unlock()
return types.GetIPNetCopy(i.addressIPv6)
}
func (i *nwIface) Routes() []*net.IPNet {
i.Lock()
defer i.Unlock()
routes := make([]*net.IPNet, len(i.routes))
for index, route := range i.routes {
r := types.GetIPNetCopy(route)
routes[index] = r
}
return routes
}
func (n *networkNamespace) Interfaces() []Interface {
n.Lock()
defer n.Unlock()
ifaces := make([]Interface, len(n.iFaces))
for i, iface := range n.iFaces {
ifaces[i] = iface
}
return ifaces
}
func (i *nwIface) Remove() error {
i.Lock()
n := i.ns
i.Unlock()
n.Lock()
path := n.path
isDefault := n.isDefault
n.Unlock()
return nsInvoke(path, func(nsFD int) error { return nil }, func(callerFD int) error {
// Find the network inteerface identified by the DstName attribute.
iface, err := netlink.LinkByName(i.DstName())
if err != nil {
return err
}
// Down the interface before configuring
if err := netlink.LinkSetDown(iface); err != nil {
return err
}
err = netlink.LinkSetName(iface, i.SrcName())
if err != nil {
fmt.Println("LinkSetName failed: ", err)
return err
}
// if it is a bridge just delete it.
if i.Bridge() {
if err := netlink.LinkDel(iface); err != nil {
return fmt.Errorf("failed deleting bridge %q: %v", i.SrcName(), err)
}
} else if !isDefault {
// Move the network interface to caller namespace.
if err := netlink.LinkSetNsFd(iface, callerFD); err != nil {
fmt.Println("LinkSetNsPid failed: ", err)
return err
}
}
n.Lock()
for index, intf := range n.iFaces {
if intf == i {
n.iFaces = append(n.iFaces[:index], n.iFaces[index+1:]...)
break
}
}
n.Unlock()
return nil
})
}
// Returns the sandbox's side veth interface statistics
func (i *nwIface) Statistics() (*types.InterfaceStatistics, error) {
i.Lock()
n := i.ns
i.Unlock()
n.Lock()
path := n.path
n.Unlock()
s := &types.InterfaceStatistics{}
err := nsInvoke(path, func(nsFD int) error { return nil }, func(callerFD int) error {
// For some reason ioutil.ReadFile(netStatsFile) reads the file in
// the default netns when this code is invoked from docker.
// Executing "cat <netStatsFile>" works as expected.
data, err := exec.Command("cat", netStatsFile).Output()
if err != nil {
return fmt.Errorf("failure opening %s: %v", netStatsFile, err)
}
return scanInterfaceStats(string(data), i.DstName(), s)
})
if err != nil {
err = fmt.Errorf("failed to retrieve the statistics for %s in netns %s: %v", i.DstName(), path, err)
}
return s, err
}
func (n *networkNamespace) findDst(srcName string, isBridge bool) string {
n.Lock()
defer n.Unlock()
for _, i := range n.iFaces {
// The master should match the srcname of the interface and the
// master interface should be of type bridge, if searching for a bridge type
if i.SrcName() == srcName && (!isBridge || i.Bridge()) {
return i.DstName()
}
}
return ""
}
func (n *networkNamespace) AddInterface(srcName, dstPrefix string, options ...IfaceOption) error {
i := &nwIface{srcName: srcName, dstName: dstPrefix, ns: n}
i.processInterfaceOptions(options...)
if i.master != "" {
i.dstMaster = n.findDst(i.master, true)
if i.dstMaster == "" {
return fmt.Errorf("could not find an appropriate master %q for %q",
i.master, i.srcName)
}
}
n.Lock()
if n.isDefault {
i.dstName = i.srcName
} else {
i.dstName = fmt.Sprintf("%s%d", i.dstName, n.nextIfIndex)
n.nextIfIndex++
}
path := n.path
isDefault := n.isDefault
n.Unlock()
return nsInvoke(path, func(nsFD int) error {
// If it is a bridge interface we have to create the bridge inside
// the namespace so don't try to lookup the interface using srcName
if i.bridge {
return nil
}
// Find the network interface identified by the SrcName attribute.
iface, err := netlink.LinkByName(i.srcName)
if err != nil {
return fmt.Errorf("failed to get link by name %q: %v", i.srcName, err)
}
// Move the network interface to the destination
// namespace only if the namespace is not a default
// type
if !isDefault {
if err := netlink.LinkSetNsFd(iface, nsFD); err != nil {
return fmt.Errorf("failed to set namespace on link %q: %v", i.srcName, err)
}
}
return nil
}, func(callerFD int) error {
if i.bridge {
link := &netlink.Bridge{
LinkAttrs: netlink.LinkAttrs{
Name: i.srcName,
},
}
if err := netlink.LinkAdd(link); err != nil {
return fmt.Errorf("failed to create bridge %q: %v", i.srcName, err)
}
}
// Find the network interface identified by the SrcName attribute.
iface, err := netlink.LinkByName(i.srcName)
if err != nil {
return fmt.Errorf("failed to get link by name %q: %v", i.srcName, err)
}
// Down the interface before configuring
if err := netlink.LinkSetDown(iface); err != nil {
return fmt.Errorf("failed to set link down: %v", err)
}
// Configure the interface now this is moved in the proper namespace.
if err := configureInterface(iface, i); err != nil {
return err
}
// Up the interface.
if err := netlink.LinkSetUp(iface); err != nil {
return fmt.Errorf("failed to set link up: %v", err)
}
// Set the routes on the interface. This can only be done when the interface is up.
if err := setInterfaceRoutes(iface, i); err != nil {
return fmt.Errorf("error setting interface %q routes to %q: %v", iface.Attrs().Name, i.Routes(), err)
}
n.Lock()
n.iFaces = append(n.iFaces, i)
n.Unlock()
return nil
})
}
func configureInterface(iface netlink.Link, i *nwIface) error {
ifaceName := iface.Attrs().Name
ifaceConfigurators := []struct {
Fn func(netlink.Link, *nwIface) error
ErrMessage string
}{
{setInterfaceName, fmt.Sprintf("error renaming interface %q to %q", ifaceName, i.DstName())},
{setInterfaceIP, fmt.Sprintf("error setting interface %q IP to %q", ifaceName, i.Address())},
{setInterfaceIPv6, fmt.Sprintf("error setting interface %q IPv6 to %q", ifaceName, i.AddressIPv6())},
{setInterfaceMaster, fmt.Sprintf("error setting interface %q master to %q", ifaceName, i.DstMaster())},
}
for _, config := range ifaceConfigurators {
if err := config.Fn(iface, i); err != nil {
return fmt.Errorf("%s: %v", config.ErrMessage, err)
}
}
return nil
}
func setInterfaceMaster(iface netlink.Link, i *nwIface) error {
if i.DstMaster() == "" {
return nil
}
return netlink.LinkSetMaster(iface, &netlink.Bridge{
LinkAttrs: netlink.LinkAttrs{Name: i.DstMaster()}})
}
func setInterfaceIP(iface netlink.Link, i *nwIface) error {
if i.Address() == nil {
return nil
}
ipAddr := &netlink.Addr{IPNet: i.Address(), Label: ""}
return netlink.AddrAdd(iface, ipAddr)
}
func setInterfaceIPv6(iface netlink.Link, i *nwIface) error {
if i.AddressIPv6() == nil {
return nil
}
ipAddr := &netlink.Addr{IPNet: i.AddressIPv6(), Label: "", Flags: syscall.IFA_F_NODAD}
return netlink.AddrAdd(iface, ipAddr)
}
func setInterfaceName(iface netlink.Link, i *nwIface) error {
return netlink.LinkSetName(iface, i.DstName())
}
func setInterfaceRoutes(iface netlink.Link, i *nwIface) error {
for _, route := range i.Routes() {
err := netlink.RouteAdd(&netlink.Route{
Scope: netlink.SCOPE_LINK,
LinkIndex: iface.Attrs().Index,
Dst: route,
})
if err != nil {
return err
}
}
return nil
}
// In older kernels (like the one in Centos 6.6 distro) sysctl does not have netns support. Therefore
// we cannot gather the statistics from /sys/class/net/<dev>/statistics/<counter> files. Per-netns stats
// are naturally found in /proc/net/dev in kernels which support netns (ifconfig relies on that).
const (
netStatsFile = "/proc/net/dev"
base = "[ ]*%s:([ ]+[0-9]+){16}"
)
func scanInterfaceStats(data, ifName string, i *types.InterfaceStatistics) error {
var (
bktStr string
bkt uint64
)
regex := fmt.Sprintf(base, ifName)
re := regexp.MustCompile(regex)
line := re.FindString(data)
_, err := fmt.Sscanf(line, "%s %d %d %d %d %d %d %d %d %d %d %d %d %d %d %d %d",
&bktStr, &i.RxBytes, &i.RxPackets, &i.RxErrors, &i.RxDropped, &bkt, &bkt, &bkt,
&bkt, &i.TxBytes, &i.TxPackets, &i.TxErrors, &i.TxDropped, &bkt, &bkt, &bkt, &bkt)
return err
}