From 9fb8d5696e83c1ad3f1b830c3771fcb04673db4e Mon Sep 17 00:00:00 2001
From: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
Date: Thu, 22 Dec 2016 04:30:40 +0000
Subject: [PATCH] proxy: fix an issue about half-closing net.TCPConn after
io.Copy()
Fix docker/docker#27539
After io.Copy(to, from), we should call to.CloseWrite(), not to.CloseRead().
Without this fix, TestTCP4ProxyHalfClose (newly added in this commit) fails as
follows:
--- FAIL: TestTCP4ProxyHalfClose (0.00s)
network_proxy_test.go:135: EOF
Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
---
libnetwork/cmd/proxy/network_proxy_test.go | 74 ++++++++++++++++------
libnetwork/cmd/proxy/tcp_proxy.go | 3 +-
2 files changed, 56 insertions(+), 21 deletions(-)
diff --git a/libnetwork/cmd/proxy/network_proxy_test.go b/libnetwork/cmd/proxy/network_proxy_test.go
index 7f036b537f..be7f8754ce 100644
--- a/libnetwork/cmd/proxy/network_proxy_test.go
+++ b/libnetwork/cmd/proxy/network_proxy_test.go
@@ -5,6 +5,7 @@ import (
"flag"
"fmt"
"io"
+ "io/ioutil"
"net"
"strings"
"testing"
@@ -22,9 +23,14 @@ type EchoServer interface {
LocalAddr() net.Addr
}
+type EchoServerOptions struct {
+ TCPHalfClose bool
+}
+
type TCPEchoServer struct {
listener net.Listener
testCtx *testing.T
+ opts EchoServerOptions
}
type UDPEchoServer struct {
@@ -32,15 +38,18 @@ type UDPEchoServer struct {
testCtx *testing.T
}
-func NewEchoServer(t *testing.T, proto, address string) EchoServer {
+func NewEchoServer(t *testing.T, proto, address string, opts EchoServerOptions) EchoServer {
var server EchoServer
if strings.HasPrefix(proto, "tcp") {
listener, err := net.Listen(proto, address)
if err != nil {
t.Fatal(err)
}
- server = &TCPEchoServer{listener: listener, testCtx: t}
+ server = &TCPEchoServer{listener: listener, testCtx: t, opts: opts}
} else {
+ if opts.TCPHalfClose {
+ t.Fatalf("TCPHalfClose is not supported for %s", proto)
+ }
socket, err := net.ListenPacket(proto, address)
if err != nil {
t.Fatal(err)
@@ -58,10 +67,21 @@ func (server *TCPEchoServer) Run() {
return
}
go func(client net.Conn) {
- if _, err := io.Copy(client, client); err != nil {
- server.testCtx.Logf("can't echo to the client: %v\n", err.Error())
+ if server.opts.TCPHalfClose {
+ data, err := ioutil.ReadAll(client)
+ if err != nil {
+ server.testCtx.Logf("io.ReadAll() failed for the client: %v\n", err.Error())
+ }
+ if _, err := client.Write(data); err != nil {
+ server.testCtx.Logf("can't echo to the client: %v\n", err.Error())
+ }
+ client.(*net.TCPConn).CloseWrite()
+ } else {
+ if _, err := io.Copy(client, client); err != nil {
+ server.testCtx.Logf("can't echo to the client: %v\n", err.Error())
+ }
+ client.Close()
}
- client.Close()
}(client)
}
}()
@@ -92,7 +112,7 @@ func (server *UDPEchoServer) Run() {
func (server *UDPEchoServer) LocalAddr() net.Addr { return server.conn.LocalAddr() }
func (server *UDPEchoServer) Close() { server.conn.Close() }
-func testProxyAt(t *testing.T, proto string, proxy Proxy, addr string) {
+func testProxyAt(t *testing.T, proto string, proxy Proxy, addr string, halfClose bool) {
defer proxy.Close()
go proxy.Run()
client, err := net.Dial(proto, addr)
@@ -104,6 +124,12 @@ func testProxyAt(t *testing.T, proto string, proxy Proxy, addr string) {
if _, err = client.Write(testBuf); err != nil {
t.Fatal(err)
}
+ if halfClose {
+ if proto != "tcp" {
+ t.Fatalf("halfClose is not supported for %s", proto)
+ }
+ client.(*net.TCPConn).CloseWrite()
+ }
recvBuf := make([]byte, testBufSize)
if _, err = client.Read(recvBuf); err != nil {
t.Fatal(err)
@@ -113,12 +139,12 @@ func testProxyAt(t *testing.T, proto string, proxy Proxy, addr string) {
}
}
-func testProxy(t *testing.T, proto string, proxy Proxy) {
- testProxyAt(t, proto, proxy, proxy.FrontendAddr().String())
+func testProxy(t *testing.T, proto string, proxy Proxy, halfClose bool) {
+ testProxyAt(t, proto, proxy, proxy.FrontendAddr().String(), halfClose)
}
-func TestTCP4Proxy(t *testing.T) {
- backend := NewEchoServer(t, "tcp", "127.0.0.1:0")
+func testTCP4Proxy(t *testing.T, halfClose bool) {
+ backend := NewEchoServer(t, "tcp", "127.0.0.1:0", EchoServerOptions{TCPHalfClose: halfClose})
defer backend.Close()
backend.Run()
frontendAddr := &net.TCPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 0}
@@ -126,12 +152,20 @@ func TestTCP4Proxy(t *testing.T) {
if err != nil {
t.Fatal(err)
}
- testProxy(t, "tcp", proxy)
+ testProxy(t, "tcp", proxy, halfClose)
+}
+
+func TestTCP4Proxy(t *testing.T) {
+ testTCP4Proxy(t, false)
+}
+
+func TestTCP4ProxyHalfClose(t *testing.T) {
+ testTCP4Proxy(t, true)
}
func TestTCP6Proxy(t *testing.T) {
t.Skip("Need to start CI docker with --ipv6")
- backend := NewEchoServer(t, "tcp", "[::1]:0")
+ backend := NewEchoServer(t, "tcp", "[::1]:0", EchoServerOptions{})
defer backend.Close()
backend.Run()
frontendAddr := &net.TCPAddr{IP: net.IPv6loopback, Port: 0}
@@ -139,14 +173,14 @@ func TestTCP6Proxy(t *testing.T) {
if err != nil {
t.Fatal(err)
}
- testProxy(t, "tcp", proxy)
+ testProxy(t, "tcp", proxy, false)
}
func TestTCPDualStackProxy(t *testing.T) {
// If I understand `godoc -src net favoriteAddrFamily` (used by the
// net.Listen* functions) correctly this should work, but it doesn't.
t.Skip("No support for dual stack yet")
- backend := NewEchoServer(t, "tcp", "[::1]:0")
+ backend := NewEchoServer(t, "tcp", "[::1]:0", EchoServerOptions{})
defer backend.Close()
backend.Run()
frontendAddr := &net.TCPAddr{IP: net.IPv6loopback, Port: 0}
@@ -158,11 +192,11 @@ func TestTCPDualStackProxy(t *testing.T) {
IP: net.IPv4(127, 0, 0, 1),
Port: proxy.FrontendAddr().(*net.TCPAddr).Port,
}
- testProxyAt(t, "tcp", proxy, ipv4ProxyAddr.String())
+ testProxyAt(t, "tcp", proxy, ipv4ProxyAddr.String(), false)
}
func TestUDP4Proxy(t *testing.T) {
- backend := NewEchoServer(t, "udp", "127.0.0.1:0")
+ backend := NewEchoServer(t, "udp", "127.0.0.1:0", EchoServerOptions{})
defer backend.Close()
backend.Run()
frontendAddr := &net.UDPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 0}
@@ -170,12 +204,12 @@ func TestUDP4Proxy(t *testing.T) {
if err != nil {
t.Fatal(err)
}
- testProxy(t, "udp", proxy)
+ testProxy(t, "udp", proxy, false)
}
func TestUDP6Proxy(t *testing.T) {
t.Skip("Need to start CI docker with --ipv6")
- backend := NewEchoServer(t, "udp", "[::1]:0")
+ backend := NewEchoServer(t, "udp", "[::1]:0", EchoServerOptions{})
defer backend.Close()
backend.Run()
frontendAddr := &net.UDPAddr{IP: net.IPv6loopback, Port: 0}
@@ -183,7 +217,7 @@ func TestUDP6Proxy(t *testing.T) {
if err != nil {
t.Fatal(err)
}
- testProxy(t, "udp", proxy)
+ testProxy(t, "udp", proxy, false)
}
func TestUDPWriteError(t *testing.T) {
@@ -204,7 +238,7 @@ func TestUDPWriteError(t *testing.T) {
// Make sure the proxy doesn't stop when there is no actual backend:
client.Write(testBuf)
client.Write(testBuf)
- backend := NewEchoServer(t, "udp", "127.0.0.1:25587")
+ backend := NewEchoServer(t, "udp", "127.0.0.1:25587", EchoServerOptions{})
defer backend.Close()
backend.Run()
client.SetDeadline(time.Now().Add(10 * time.Second))
diff --git a/libnetwork/cmd/proxy/tcp_proxy.go b/libnetwork/cmd/proxy/tcp_proxy.go
index 1c713105db..700054af99 100644
--- a/libnetwork/cmd/proxy/tcp_proxy.go
+++ b/libnetwork/cmd/proxy/tcp_proxy.go
@@ -48,7 +48,8 @@ func (proxy *TCPProxy) clientLoop(client *net.TCPConn, quit chan bool) {
from.CloseWrite()
}
}
- to.CloseRead()
+ from.CloseRead()
+ to.CloseWrite()
wg.Done()
}