update vendor

Signed-off-by: Jess Frazelle <acidburn@microsoft.com>

vendor/github.com/docker/go-connections/proxy/proxy.go

@@ -0,0 +1,36 @@
+// Package proxy provides a network Proxy interface and implementations for TCP and UDP.
+package proxy
+
+import (
+	"fmt"
+	"net"
+)
+
+// Proxy defines the behavior of a proxy. It forwards traffic back and forth
+// between two endpoints : the frontend and the backend.
+// It can be used to do software port-mapping between two addresses.
+// e.g. forward all traffic between the frontend (host) 127.0.0.1:3000
+// to the backend (container) at 172.17.42.108:4000.
+type Proxy interface {
+	// Run starts forwarding traffic back and forth between the front
+	// and back-end addresses.
+	Run()
+	// Close stops forwarding traffic and close both ends of the Proxy.
+	Close()
+	// FrontendAddr returns the address on which the proxy is listening.
+	FrontendAddr() net.Addr
+	// BackendAddr returns the proxied address.
+	BackendAddr() net.Addr
+}
+
+// NewProxy creates a Proxy according to the specified frontendAddr and backendAddr.
+func NewProxy(frontendAddr, backendAddr net.Addr) (Proxy, error) {
+	switch frontendAddr.(type) {
+	case *net.UDPAddr:
+		return NewUDPProxy(frontendAddr.(*net.UDPAddr), backendAddr.(*net.UDPAddr))
+	case *net.TCPAddr:
+		return NewTCPProxy(frontendAddr.(*net.TCPAddr), backendAddr.(*net.TCPAddr))
+	default:
+		panic(fmt.Errorf("Unsupported protocol"))
+	}
+}