package proxy import ( "bytes" "fmt" "io" "net" "strings" "testing" "time" ) var testBuf = []byte("Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo") var testBufSize = len(testBuf) type EchoServer interface { Run() Close() LocalAddr() net.Addr } type TCPEchoServer struct { listener net.Listener testCtx *testing.T } type UDPEchoServer struct { conn net.PacketConn testCtx *testing.T } func NewEchoServer(t *testing.T, proto, address string) 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} } else { socket, err := net.ListenPacket(proto, address) if err != nil { t.Fatal(err) } server = &UDPEchoServer{conn: socket, testCtx: t} } return server } func (server *TCPEchoServer) Run() { go func() { for { client, err := server.listener.Accept() if err != nil { 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()) } client.Close() }(client) } }() } func (server *TCPEchoServer) LocalAddr() net.Addr { return server.listener.Addr() } func (server *TCPEchoServer) Close() { server.listener.Close() } func (server *UDPEchoServer) Run() { go func() { readBuf := make([]byte, 1024) for { read, from, err := server.conn.ReadFrom(readBuf) if err != nil { return } for i := 0; i != read; { written, err := server.conn.WriteTo(readBuf[i:read], from) if err != nil { break } i += written } } }() } 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) { defer proxy.Close() go proxy.Run() client, err := net.Dial(proto, addr) if err != nil { t.Fatalf("Can't connect to the proxy: %v", err) } defer client.Close() client.SetDeadline(time.Now().Add(10 * time.Second)) if _, err = client.Write(testBuf); err != nil { t.Fatal(err) } recvBuf := make([]byte, testBufSize) if _, err = client.Read(recvBuf); err != nil { t.Fatal(err) } if !bytes.Equal(testBuf, recvBuf) { t.Fatal(fmt.Errorf("Expected [%v] but got [%v]", testBuf, recvBuf)) } } func testProxy(t *testing.T, proto string, proxy Proxy) { testProxyAt(t, proto, proxy, proxy.FrontendAddr().String()) } func TestTCP4Proxy(t *testing.T) { backend := NewEchoServer(t, "tcp", "127.0.0.1:0") defer backend.Close() backend.Run() frontendAddr := &net.TCPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 0} proxy, err := NewProxy(frontendAddr, backend.LocalAddr()) if err != nil { t.Fatal(err) } testProxy(t, "tcp", proxy) } func TestTCP6Proxy(t *testing.T) { backend := NewEchoServer(t, "tcp", "[::1]:0") defer backend.Close() backend.Run() frontendAddr := &net.TCPAddr{IP: net.IPv6loopback, Port: 0} proxy, err := NewProxy(frontendAddr, backend.LocalAddr()) if err != nil { t.Fatal(err) } testProxy(t, "tcp", proxy) } 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") defer backend.Close() backend.Run() frontendAddr := &net.TCPAddr{IP: net.IPv6loopback, Port: 0} proxy, err := NewProxy(frontendAddr, backend.LocalAddr()) if err != nil { t.Fatal(err) } ipv4ProxyAddr := &net.TCPAddr{ IP: net.IPv4(127, 0, 0, 1), Port: proxy.FrontendAddr().(*net.TCPAddr).Port, } testProxyAt(t, "tcp", proxy, ipv4ProxyAddr.String()) } func TestUDP4Proxy(t *testing.T) { backend := NewEchoServer(t, "udp", "127.0.0.1:0") defer backend.Close() backend.Run() frontendAddr := &net.UDPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 0} proxy, err := NewProxy(frontendAddr, backend.LocalAddr()) if err != nil { t.Fatal(err) } testProxy(t, "udp", proxy) } func TestUDP6Proxy(t *testing.T) { backend := NewEchoServer(t, "udp", "[::1]:0") defer backend.Close() backend.Run() frontendAddr := &net.UDPAddr{IP: net.IPv6loopback, Port: 0} proxy, err := NewProxy(frontendAddr, backend.LocalAddr()) if err != nil { t.Fatal(err) } testProxy(t, "udp", proxy) } func TestUDPWriteError(t *testing.T) { frontendAddr := &net.UDPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 0} // Hopefully, this port will be free: */ backendAddr := &net.UDPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 25587} proxy, err := NewProxy(frontendAddr, backendAddr) if err != nil { t.Fatal(err) } defer proxy.Close() go proxy.Run() client, err := net.Dial("udp", "127.0.0.1:25587") if err != nil { t.Fatalf("Can't connect to the proxy: %v", err) } defer client.Close() // 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") defer backend.Close() backend.Run() client.SetDeadline(time.Now().Add(10 * time.Second)) if _, err = client.Write(testBuf); err != nil { t.Fatal(err) } recvBuf := make([]byte, testBufSize) if _, err = client.Read(recvBuf); err != nil { t.Fatal(err) } if !bytes.Equal(testBuf, recvBuf) { t.Fatal(fmt.Errorf("Expected [%v] but got [%v]", testBuf, recvBuf)) } }