From 198dc8ba73be40fea7bb97dc58ecdb194a4e1a8f Mon Sep 17 00:00:00 2001
From: David Scott <dave@recoil.org>
Date: Fri, 29 Apr 2016 11:55:06 +0100
Subject: [PATCH] proxy: bind the IP port as well as the vsock port

Previously the proxy would listen only on the vsock port, which is
fine for accessing the port on the host, but if a container also wants
to access the port (e.g. via `--net=host` and using the Moby IP) then
we need to listen on the IP too.

Related to [docker/pinata#2854]

Signed-off-by: David Scott <dave.scott@docker.com>
---
 alpine/packages/proxy/libproxy/proxy.go | 30 +++++++++++++++++++++++--
 alpine/packages/proxy/main.go           | 12 +++++++---
 2 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/alpine/packages/proxy/libproxy/proxy.go b/alpine/packages/proxy/libproxy/proxy.go
index b7b89f27d..472a0a5db 100644
--- a/alpine/packages/proxy/libproxy/proxy.go
+++ b/alpine/packages/proxy/libproxy/proxy.go
@@ -25,8 +25,8 @@ type Proxy interface {
 	BackendAddr() net.Addr
 }
 
-// NewProxy creates a Proxy according to the specified frontendAddr and backendAddr.
-func NewProxy(frontendAddr *vsock.VsockAddr, backendAddr net.Addr) (Proxy, error) {
+// NewVsockProxy creates a Proxy listening on Vsock
+func NewVsockProxy(frontendAddr *vsock.VsockAddr, backendAddr net.Addr) (Proxy, error) {
 	switch backendAddr.(type) {
 	case *net.UDPAddr:
 		listener, err := vsock.Listen(frontendAddr.Port)
@@ -44,3 +44,29 @@ func NewProxy(frontendAddr *vsock.VsockAddr, backendAddr net.Addr) (Proxy, error
 		panic(fmt.Errorf("Unsupported protocol"))
 	}
 }
+
+// NewIPProxy creates a Proxy according to the specified frontendAddr and backendAddr.
+func NewIPProxy(frontendAddr, backendAddr net.Addr) (Proxy, error) {
+        switch frontendAddr.(type) {
+        case *net.UDPAddr:
+                listener, err := net.ListenUDP("udp", frontendAddr.(*net.UDPAddr))
+                if err != nil {
+                        return nil, err
+                }
+                return NewUDPProxy(frontendAddr, listener, backendAddr.(*net.UDPAddr))
+        case *net.TCPAddr:
+                listener, err := net.Listen("tcp", frontendAddr.String())
+                if err != nil {
+                        return nil, err
+                }
+                return NewTCPProxy(listener, backendAddr.(*net.TCPAddr))
+        case *vsock.VsockAddr:
+                listener, err := vsock.Listen(frontendAddr.(*vsock.VsockAddr).Port)
+                if err != nil {
+                        return nil, err
+                }
+                return NewTCPProxy(listener, backendAddr.(*net.TCPAddr))
+        default:
+                panic(fmt.Errorf("Unsupported protocol"))
+        }
+}
diff --git a/alpine/packages/proxy/main.go b/alpine/packages/proxy/main.go
index a7ab17b15..aa44b2b8f 100644
--- a/alpine/packages/proxy/main.go
+++ b/alpine/packages/proxy/main.go
@@ -14,19 +14,25 @@ import (
 func main() {
 	host, port, container := parseHostContainerAddrs()
 
-	p, err := libproxy.NewProxy(&vsock.VsockAddr{Port: uint(port)}, container)
+	vsockP, err := libproxy.NewVsockProxy(&vsock.VsockAddr{Port: uint(port)}, container)
 	if err != nil {
 		sendError(err)
 	}
+	ipP, err := libproxy.NewIPProxy(host, container)
+	if err != nil {
+		sendError(err)
+	}
+
 	ctl, err := exposePort(host, port)
 	if err != nil {
 		sendError(err)
 	}
 
-	go handleStopSignals(p)
+	go handleStopSignals(ipP)
 	// TODO: avoid this line if we are running in a TTY
 	sendOK()
-	p.Run()
+	go ipP.Run()
+	vsockP.Run()
 	ctl.Close() // ensure ctl remains alive and un-GCed until here
 	os.Exit(0)
 }