1 files changed, 89 insertions, 0 deletions
diff --git a/vendor/github.com/jackpal/go-nat-pmp/network.go b/vendor/github.com/jackpal/go-nat-pmp/network.go
new file mode 100644
index 000000000..c42b4fee9
--- /dev/null
+++ b/vendor/github.com/jackpal/go-nat-pmp/network.go
@@ -0,0 +1,89 @@
+package natpmp
+
+import (
+	"fmt"
+	"net"
+	"time"
+)
+
+const nAT_PMP_PORT = 5351
+const nAT_TRIES = 9
+const nAT_INITIAL_MS = 250
+
+// A caller that implements the NAT-PMP RPC protocol.
+type network struct {
+	gateway net.IP
+}
+
+func (n *network) call(msg []byte, timeout time.Duration) (result []byte, err error) {
+	var server net.UDPAddr
+	server.IP = n.gateway
+	server.Port = nAT_PMP_PORT
+	conn, err := net.DialUDP("udp", nil, &server)
+	if err != nil {
+		return
+	}
+	defer conn.Close()
+
+	// 16 bytes is the maximum result size.
+	result = make([]byte, 16)
+
+	var finalTimeout time.Time
+	if timeout != 0 {
+		finalTimeout = time.Now().Add(timeout)
+	}
+
+	needNewDeadline := true
+
+	var tries uint
+	for tries = 0; (tries < nAT_TRIES && finalTimeout.IsZero()) || time.Now().Before(finalTimeout); {
+		if needNewDeadline {
+			nextDeadline := time.Now().Add((nAT_INITIAL_MS << tries) * time.Millisecond)
+			err = conn.SetDeadline(minTime(nextDeadline, finalTimeout))
+			if err != nil {
+				return
+			}
+			needNewDeadline = false
+		}
+		_, err = conn.Write(msg)
+		if err != nil {
+			return
+		}
+		var bytesRead int
+		var remoteAddr *net.UDPAddr
+		bytesRead, remoteAddr, err = conn.ReadFromUDP(result)
+		if err != nil {
+			if err.(net.Error).Timeout() {
+				tries++
+				needNewDeadline = true
+				continue
+			}
+			return
+		}
+		if !remoteAddr.IP.Equal(n.gateway) {
+			// Ignore this packet.
+			// Continue without increasing retransmission timeout or deadline.
+			continue
+		}
+		// Trim result to actual number of bytes received
+		if bytesRead < len(result) {
+			result = result[:bytesRead]
+		}
+		return
+	}
+	err = fmt.Errorf("Timed out trying to contact gateway")
+	return
+}
+
+func minTime(a, b time.Time) time.Time {
+	if a.IsZero() {
+		return b
+	}
+	if b.IsZero() {
+		return a
+	}
+	if a.Before(b) {
+		return a
+	}
+	return b
+}