func SetInterfaceMac(name string, macaddr string) error {
iface, err := net.InterfaceByName(name)
if err != nil {
return err
}
return netlink.NetworkSetMacAddress(iface, macaddr)
}
func (v *veth) initialize(config *network) error {
peer := config.TempVethPeerName
if peer == "" {
return fmt.Errorf("peer is not specified")
}
child, err := net.InterfaceByName(peer)
if err != nil {
return err
}
if err := netlink.NetworkLinkDown(child); err != nil {
return err
}
if err := netlink.NetworkChangeName(child, config.Name); err != nil {
return err
}
// get the interface again after we changed the name as the index also changes.
if child, err = net.InterfaceByName(config.Name); err != nil {
return err
}
if config.MacAddress != "" {
if err := netlink.NetworkSetMacAddress(child, config.MacAddress); err != nil {
return err
}
}
ip, ipNet, err := net.ParseCIDR(config.Address)
if err != nil {
return err
}
if err := netlink.NetworkLinkAddIp(child, ip, ipNet); err != nil {
return err
}
if config.IPv6Address != "" {
if ip, ipNet, err = net.ParseCIDR(config.IPv6Address); err != nil {
return err
}
if err := netlink.NetworkLinkAddIp(child, ip, ipNet); err != nil {
return err
}
}
if err := netlink.NetworkSetMTU(child, config.Mtu); err != nil {
return err
}
if err := netlink.NetworkLinkUp(child); err != nil {
return err
}
if config.Gateway != "" {
if err := netlink.AddDefaultGw(config.Gateway, config.Name); err != nil {
return err
}
}
if config.IPv6Gateway != "" {
if err := netlink.AddDefaultGw(config.IPv6Gateway, config.Name); err != nil {
return err
}
}
return nil
}
// NewMacVtapLinkWithOptions creates macvtap network link and can set some of its network parameters
// passed in as MacVlanOptions.
//
// It is equivalent of running:
// ip link add name ${macvlan name} link ${master interface} address ${macaddress} type macvtap mode ${mode}
// NewMacVtapLinkWithOptions returns MacVtaper which is initialized to a pointer of type MacVtapLink if the
// macvtap link was created successfully on the Linux host. It returns error if the macvtap link could not be created.
func NewMacVtapLinkWithOptions(masterDev string, opts MacVlanOptions) (MacVtaper, error) {
if ok, err := NetInterfaceNameValid(masterDev); !ok {
return nil, err
}
if _, err := net.InterfaceByName(masterDev); err != nil {
return nil, fmt.Errorf("Master MAC VLAN device %s does not exist on the host", masterDev)
}
if err := validateMacVlanOptions(&opts); err != nil {
return nil, err
}
if err := netlink.NetworkLinkAddMacVtap(masterDev, opts.Dev, opts.Mode); err != nil {
return nil, err
}
macVtapIfc, err := net.InterfaceByName(opts.Dev)
if err != nil {
return nil, fmt.Errorf("Could not find the new interface: %s", err)
}
if opts.MacAddr != "" {
if err := netlink.NetworkSetMacAddress(macVtapIfc, opts.MacAddr); err != nil {
if errDel := DeleteLink(macVtapIfc.Name); errDel != nil {
return nil, fmt.Errorf("Incorrect options specified. Attempt to delete the link failed: %s",
errDel)
}
}
}
masterIfc, err := net.InterfaceByName(masterDev)
if err != nil {
return nil, fmt.Errorf("Could not find the new interface: %s", err)
}
return &MacVtapLink{
MacVlanLink: &MacVlanLink{
Link: Link{
ifc: macVtapIfc,
},
masterIfc: masterIfc,
mode: opts.Mode,
},
}, nil
}
func createBridge(name, network, natIface string) (*Bridge, error) {
ipAddr, ipNet, err := net.ParseCIDR(network)
if err != nil {
return nil, err
}
if err := netlink.CreateBridge(name, true); err != nil {
return nil, err
}
iface, err := net.InterfaceByName(name)
if err != nil {
return nil, err
}
// We need to explicitly assign the MAC address to avoid it changing to a lower value
// See: https://github.com/flynn/flynn/issues/223
b := random.Bytes(5)
mac := fmt.Sprintf("fe:%02x:%02x:%02x:%02x:%02x", b[0], b[1], b[2], b[3], b[4])
if err := netlink.NetworkSetMacAddress(iface, mac); err != nil {
return nil, err
}
if err := netlink.NetworkLinkAddIp(iface, ipAddr, ipNet); err != nil {
return nil, err
}
if err := netlink.NetworkLinkUp(iface); err != nil {
return nil, err
}
if err := ioutil.WriteFile("/proc/sys/net/ipv4/ip_forward", []byte("1\n"), 0644); err != nil {
return nil, err
}
if err := setupIPTables(name, natIface); err != nil {
return nil, err
}
bridge := &Bridge{
name: name,
iface: iface,
ipAddr: ipAddr,
ipNet: ipNet,
alloc: ipallocator.New(),
}
bridge.alloc.RequestIP(ipNet, ipAddr)
return bridge, nil
}
// ConfigureNetworking is called once during host startup and sets up the local
// bridge and forwarding rules for containers.
func (l *LibcontainerBackend) ConfigureNetworking(config *host.NetworkConfig) error {
log := l.logger.New("fn", "ConfigureNetworking")
var err error
l.bridgeAddr, l.bridgeNet, err = net.ParseCIDR(config.Subnet)
if err != nil {
return err
}
l.ipalloc.RequestIP(l.bridgeNet, l.bridgeAddr)
err = netlink.CreateBridge(l.bridgeName, false)
bridgeExists := os.IsExist(err)
if err != nil && !bridgeExists {
return err
}
bridge, err := net.InterfaceByName(l.bridgeName)
if err != nil {
return err
}
if !bridgeExists {
// We need to explicitly assign the MAC address to avoid it changing to a lower value
// See: https://github.com/flynn/flynn/issues/223
b := random.Bytes(5)
bridgeMAC := fmt.Sprintf("fe:%02x:%02x:%02x:%02x:%02x", b[0], b[1], b[2], b[3], b[4])
if err := netlink.NetworkSetMacAddress(bridge, bridgeMAC); err != nil {
return err
}
}
currAddrs, err := bridge.Addrs()
if err != nil {
return err
}
setIP := true
for _, addr := range currAddrs {
ip, net, _ := net.ParseCIDR(addr.String())
if ip.Equal(l.bridgeAddr) && net.String() == l.bridgeNet.String() {
setIP = false
} else {
if err := netlink.NetworkLinkDelIp(bridge, ip, net); err != nil {
return err
}
}
}
if setIP {
if err := netlink.NetworkLinkAddIp(bridge, l.bridgeAddr, l.bridgeNet); err != nil {
return err
}
}
if err := netlink.NetworkLinkUp(bridge); err != nil {
return err
}
// enable IP forwarding
if err := ioutil.WriteFile("/proc/sys/net/ipv4/ip_forward", []byte("1\n"), 0644); err != nil {
return err
}
// Set up iptables for outbound traffic masquerading from containers to the
// rest of the network.
if err := iptables.EnableOutboundNAT(l.bridgeName, l.bridgeNet.String()); err != nil {
return err
}
// Read DNS config, discoverd uses the nameservers
dnsConf, err := dns.ClientConfigFromFile("/etc/resolv.conf")
if err != nil {
return err
}
config.Resolvers = dnsConf.Servers
// Write a resolv.conf to be bind-mounted into containers pointing at the
// future discoverd DNS listener
if err := os.MkdirAll("/etc/flynn", 0755); err != nil {
return err
}
var resolvSearch string
if len(dnsConf.Search) > 0 {
resolvSearch = fmt.Sprintf("search %s\n", strings.Join(dnsConf.Search, " "))
}
if err := ioutil.WriteFile("/etc/flynn/resolv.conf", []byte(fmt.Sprintf("%snameserver %s\n", resolvSearch, l.bridgeAddr.String())), 0644); err != nil {
return err
}
l.resolvConf = "/etc/flynn/resolv.conf"
// Allocate IPs for running jobs
l.containersMtx.Lock()
defer l.containersMtx.Unlock()
for _, container := range l.containers {
if !container.job.Config.HostNetwork {
if _, err := l.ipalloc.RequestIP(l.bridgeNet, container.IP); err != nil {
log.Error("error requesting ip", "job.id", container.job.ID, "err", err)
}
}
}
close(l.networkConfigured)
return nil
}
// setLinkOptions validates and sets link's various options passed in as LinkOptions.
func setLinkOptions(ifc *net.Interface, opts LinkOptions) error {
macaddr, mtu, flags, ns := opts.MacAddr, opts.MTU, opts.Flags, opts.Ns
// if MTU is passed in LinkOptions
if mtu != 0 {
if err := validMtu(mtu); err != nil {
return err
}
if err := netlink.NetworkSetMTU(ifc, mtu); err != nil {
return fmt.Errorf("Unable to set MTU: %s", err)
}
}
// if MacAddress is passed in LinkOptions
if macaddr != "" {
if err := validMacAddress(macaddr); err != nil {
return err
}
if err := netlink.NetworkSetMacAddress(ifc, macaddr); err != nil {
return fmt.Errorf("Unable to set MAC Address: %s", err)
}
}
// if ns is passed in LinkOptions
if ns != 0 {
if err := validNs(ns); err != nil {
return err
}
if err := netlink.NetworkSetNsPid(ifc, ns); err != nil {
return fmt.Errorf("Unable to set Network namespace: %s", err)
}
}
// if flags is passed in LinkOptions
if flags != 0 {
if err := validFlags(flags); err != nil {
return err
}
if ns != 0 && (ns != 1 || ns != os.Getpid()) {
if (flags & syscall.IFF_UP) == syscall.IFF_UP {
origNs, _ := NetNsHandle(os.Getpid())
defer syscall.Close(int(origNs))
defer system.Setns(origNs, syscall.CLONE_NEWNET)
if err := SetNetNsToPid(ns); err != nil {
return fmt.Errorf("Switching to %d network namespace failed: %s", ns, err)
}
if err := netlink.NetworkLinkUp(ifc); err != nil {
return fmt.Errorf("Unable to bring %s interface UP: %s", ifc.Name, ns)
}
}
} else {
if err := netlink.NetworkLinkUp(ifc); err != nil {
return fmt.Errorf("Could not bring up network link %s: %s", ifc.Name, err)
}
}
}
return nil
}
// SetLinkMacAddress sets link's MAC address.
// It is equivalent of running: ip link set dev ${interface name} address ${address}
func (l *Link) SetLinkMacAddress(macaddr string) error {
return netlink.NetworkSetMacAddress(l.NetInterface(), macaddr)
}