diff options
Diffstat (limited to 'vendor/github.com/jackpal/go-nat-pmp/natpmp.go')
| -rw-r--r-- | vendor/github.com/jackpal/go-nat-pmp/natpmp.go | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/vendor/github.com/jackpal/go-nat-pmp/natpmp.go b/vendor/github.com/jackpal/go-nat-pmp/natpmp.go new file mode 100644 index 000000000..5ca7680e4 --- /dev/null +++ b/vendor/github.com/jackpal/go-nat-pmp/natpmp.go @@ -0,0 +1,153 @@ +package natpmp + +import ( + "fmt" + "net" + "time" +) + +// Implement the NAT-PMP protocol, typically supported by Apple routers and open source +// routers such as DD-WRT and Tomato. +// +// See http://tools.ietf.org/html/draft-cheshire-nat-pmp-03 +// +// Usage: +// +// client := natpmp.NewClient(gatewayIP) +// response, err := client.GetExternalAddress() + +// The recommended mapping lifetime for AddPortMapping +const RECOMMENDED_MAPPING_LIFETIME_SECONDS = 3600 + +// Interface used to make remote procedure calls. +type caller interface { + call(msg []byte, timeout time.Duration) (result []byte, err error) +} + +// Client is a NAT-PMP protocol client. +type Client struct { + caller caller + timeout time.Duration +} + +// Create a NAT-PMP client for the NAT-PMP server at the gateway. +// Uses default timeout which is around 128 seconds. +func NewClient(gateway net.IP) (nat *Client) { + return &Client{&network{gateway}, 0} +} + +// Create a NAT-PMP client for the NAT-PMP server at the gateway, with a timeout. +// Timeout defines the total amount of time we will keep retrying before giving up. +func NewClientWithTimeout(gateway net.IP, timeout time.Duration) (nat *Client) { + return &Client{&network{gateway}, timeout} +} + +// Results of the NAT-PMP GetExternalAddress operation. +type GetExternalAddressResult struct { + SecondsSinceStartOfEpoc uint32 + ExternalIPAddress [4]byte +} + +// Get the external address of the router. +func (n *Client) GetExternalAddress() (result *GetExternalAddressResult, err error) { + msg := make([]byte, 2) + msg[0] = 0 // Version 0 + msg[1] = 0 // OP Code 0 + response, err := n.rpc(msg, 12) + if err != nil { + return + } + result = &GetExternalAddressResult{} + result.SecondsSinceStartOfEpoc = readNetworkOrderUint32(response[4:8]) + copy(result.ExternalIPAddress[:], response[8:12]) + return +} + +// Results of the NAT-PMP AddPortMapping operation +type AddPortMappingResult struct { + SecondsSinceStartOfEpoc uint32 + InternalPort uint16 + MappedExternalPort uint16 + PortMappingLifetimeInSeconds uint32 +} + +// Add (or delete) a port mapping. To delete a mapping, set the requestedExternalPort and lifetime to 0 +func (n *Client) AddPortMapping(protocol string, internalPort, requestedExternalPort int, lifetime int) (result *AddPortMappingResult, err error) { + var opcode byte + if protocol == "udp" { + opcode = 1 + } else if protocol == "tcp" { + opcode = 2 + } else { + err = fmt.Errorf("unknown protocol %v", protocol) + return + } + msg := make([]byte, 12) + msg[0] = 0 // Version 0 + msg[1] = opcode + writeNetworkOrderUint16(msg[4:6], uint16(internalPort)) + writeNetworkOrderUint16(msg[6:8], uint16(requestedExternalPort)) + writeNetworkOrderUint32(msg[8:12], uint32(lifetime)) + response, err := n.rpc(msg, 16) + if err != nil { + return + } + result = &AddPortMappingResult{} + result.SecondsSinceStartOfEpoc = readNetworkOrderUint32(response[4:8]) + result.InternalPort = readNetworkOrderUint16(response[8:10]) + result.MappedExternalPort = readNetworkOrderUint16(response[10:12]) + result.PortMappingLifetimeInSeconds = readNetworkOrderUint32(response[12:16]) + return +} + +func (n *Client) rpc(msg []byte, resultSize int) (result []byte, err error) { + result, err = n.caller.call(msg, n.timeout) + if err != nil { + return + } + err = protocolChecks(msg, resultSize, result) + return +} + +func protocolChecks(msg []byte, resultSize int, result []byte) (err error) { + if len(result) != resultSize { + err = fmt.Errorf("unexpected result size %d, expected %d", len(result), resultSize) + return + } + if result[0] != 0 { + err = fmt.Errorf("unknown protocol version %d", result[0]) + return + } + expectedOp := msg[1] | 0x80 + if result[1] != expectedOp { + err = fmt.Errorf("Unexpected opcode %d. Expected %d", result[1], expectedOp) + return + } + resultCode := readNetworkOrderUint16(result[2:4]) + if resultCode != 0 { + err = fmt.Errorf("Non-zero result code %d", resultCode) + return + } + // If we got here the RPC is good. + return +} + +func writeNetworkOrderUint16(buf []byte, d uint16) { + buf[0] = byte(d >> 8) + buf[1] = byte(d) +} + +func writeNetworkOrderUint32(buf []byte, d uint32) { + buf[0] = byte(d >> 24) + buf[1] = byte(d >> 16) + buf[2] = byte(d >> 8) + buf[3] = byte(d) +} + +func readNetworkOrderUint16(buf []byte) uint16 { + return (uint16(buf[0]) << 8) | uint16(buf[1]) +} + +func readNetworkOrderUint32(buf []byte) uint32 { + return (uint32(buf[0]) << 24) | (uint32(buf[1]) << 16) | (uint32(buf[2]) << 8) | uint32(buf[3]) +} |