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) }