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Add Dialer.
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@garyburd
garyburd committed Dec 14, 2013
1 parent 2119675 commit 87accae
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Showing 2 changed files with 294 additions and 17 deletions.
153 changes: 152 additions & 1 deletion client.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -5,11 +5,13 @@
package websocket

import (
"crypto/tls"
"errors"
"net"
"net/http"
"net/url"
"strings"
"time"
)

// ErrBadHandshake is returned when the server response to opening handshake is
Expand All @@ -18,7 +20,7 @@ var ErrBadHandshake = errors.New("websocket: bad handshake")

// NewClient creates a new client connection using the given net connection.
// The URL u specifies the host and request URI. Use requestHeader to specify
// the origin (Origin), subprotocols (Set-WebSocket-Protocol) and cookies
// the origin (Origin), subprotocols (Sec-WebSocket-Protocol) and cookies
// (Cookie). Use the response.Header to get the selected subprotocol
// (Sec-WebSocket-Protocol) and cookies (Set-Cookie).
//
Expand Down Expand Up @@ -67,3 +69,152 @@ func NewClient(netConn net.Conn, u *url.URL, requestHeader http.Header, readBufS
}
return c, resp, nil
}

type Dialer struct {
// NetDial specifies the dial function for creating TCP connections. If
// NetDial is nil, net.Dial is used.
NetDial func(network, addr string) (net.Conn, error)

// TLSClientConfig specifies the TLS configuration to use with tls.Client.
// If nil, the default configuration is used.
TLSClientConfig *tls.Config

// HandshakeTimeout specifies the duration for the handshake to complete.
HandshakeTimeout time.Duration

// Input and output buffer sizes. If the buffer size is zero, then a
// default value of 4096 is used.
ReadBufferSize, WriteBufferSize int
}

var errMalformedURL = errors.New("malformed ws or wss URL")

func parseURL(u string) (useTLS bool, host, port, opaque string, err error) {
// From the RFC:
//
// ws-URI = "ws:" "//" host [ ":" port ] path [ "?" query ]
// wss-URI = "wss:" "//" host [ ":" port ] path [ "?" query ]
//
// We don't use the net/url parser here because the dialer interface does
// not provide a way for applications to work around percent deocding in
// the net/url parser.

switch {
case strings.HasPrefix(u, "ws://"):
u = u[len("ws://"):]
case strings.HasPrefix(u, "wss://"):
u = u[len("wss://"):]
useTLS = true
default:
return false, "", "", "", errMalformedURL
}

hostPort := u
opaque = "/"
if i := strings.Index(u, "/"); i >= 0 {
hostPort = u[:i]
opaque = u[i:]
}

host = hostPort
port = ":80"
if i := strings.LastIndex(hostPort, ":"); i > strings.LastIndex(hostPort, "]") {
host = hostPort[:i]
port = hostPort[i:]
} else if useTLS {
port = ":443"
}

return useTLS, host, port, opaque, nil
}

var DefaultDialer *Dialer

// Dial creates a new client connection. Use requestHeader to specify the
// origin (Origin), subprotocols (Sec-WebSocket-Protocol) and cookies (Cookie).
// Use the response.Header to get the selected subprotocol
// (Sec-WebSocket-Protocol) and cookies (Set-Cookie).
//
// If the WebSocket handshake fails, ErrBadHandshake is returned along with a
// non-nil *http.Response so that callers can handle redirects, authentication,
// etc.
func (d *Dialer) Dial(urlStr string, requestHeader http.Header) (*Conn, *http.Response, error) {

useTLS, host, port, opaque, err := parseURL(urlStr)
if err != nil {
return nil, nil, err
}

if d == nil {
d = &Dialer{}
}

var deadline time.Time
if d.HandshakeTimeout != 0 {
deadline = time.Now().Add(d.HandshakeTimeout)
}

netDial := d.NetDial
if netDial == nil {
netDialer := &net.Dialer{Deadline: deadline}
netDial = netDialer.Dial
}

netConn, err := netDial("tcp", host+port)
if err != nil {
return nil, nil, err
}

defer func() {
if netConn != nil {
netConn.Close()
}
}()

if err := netConn.SetDeadline(deadline); err != nil {
return nil, nil, err
}

if useTLS {
cfg := d.TLSClientConfig
if cfg == nil {
cfg = &tls.Config{ServerName: host}
} else if cfg.ServerName == "" {
shallowCopy := *cfg
cfg = &shallowCopy
cfg.ServerName = host
}
tlsConn := tls.Client(netConn, cfg)
netConn = tlsConn
if err := tlsConn.Handshake(); err != nil {
return nil, nil, err
}
if !cfg.InsecureSkipVerify {
if err := tlsConn.VerifyHostname(cfg.ServerName); err != nil {
return nil, nil, err
}
}
}

readBufferSize := d.ReadBufferSize
if readBufferSize == 0 {
readBufferSize = 4096
}

writeBufferSize := d.WriteBufferSize
if writeBufferSize == 0 {
writeBufferSize = 4096
}

conn, resp, err := NewClient(
netConn,
&url.URL{Host: host + port, Opaque: opaque},
requestHeader, readBufferSize, writeBufferSize)
if err != nil {
return nil, resp, err
}

netConn.SetDeadline(time.Time{})
netConn = nil // to avoid close in defer.
return conn, resp, nil
}
158 changes: 142 additions & 16 deletions client_server_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2,9 +2,11 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package websocket_test
package websocket

import (
"crypto/tls"
"crypto/x509"
"io"
"io/ioutil"
"net"
Expand All @@ -13,15 +15,13 @@ import (
"net/url"
"testing"
"time"

"github.com/gorilla/websocket"
)

type wsHandler struct {
type handshakeHandler struct {
*testing.T
}

func (t wsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
func (t handshakeHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
if r.Method != "GET" {
http.Error(w, "Method not allowed", 405)
t.Logf("bad method: %s", r.Method)
Expand All @@ -32,8 +32,8 @@ func (t wsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
t.Logf("bad origin: %s", r.Header.Get("Origin"))
return
}
ws, err := websocket.Upgrade(w, r, http.Header{"Set-Cookie": {"sessionID=1234"}}, 1024, 1024)
if _, ok := err.(websocket.HandshakeError); ok {
ws, err := Upgrade(w, r, http.Header{"Set-Cookie": {"sessionID=1234"}}, 1024, 1024)
if _, ok := err.(HandshakeError); ok {
t.Logf("bad handshake: %v", err)
http.Error(w, "Not a websocket handshake", 400)
return
Expand All @@ -50,9 +50,6 @@ func (t wsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
}
return
}
if op == websocket.PongMessage {
continue
}
w, err := ws.NextWriter(op)
if err != nil {
t.Logf("NextWriter: %v", err)
Expand All @@ -69,15 +66,15 @@ func (t wsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
}
}

func TestClientServer(t *testing.T) {
s := httptest.NewServer(wsHandler{t})
func TestHandshake(t *testing.T) {
s := httptest.NewServer(handshakeHandler{t})
defer s.Close()
u, _ := url.Parse(s.URL)
c, err := net.Dial("tcp", u.Host)
if err != nil {
t.Fatalf("Dial: %v", err)
}
ws, resp, err := websocket.NewClient(c, u, http.Header{"Origin": {s.URL}}, 1024, 1024)
ws, resp, err := NewClient(c, u, http.Header{"Origin": {s.URL}}, 1024, 1024)
if err != nil {
t.Fatalf("NewClient: %v", err)
}
Expand All @@ -93,16 +90,16 @@ func TestClientServer(t *testing.T) {
t.Error("Set-Cookie not received from the server.")
}

w, _ := ws.NextWriter(websocket.TextMessage)
w, _ := ws.NextWriter(TextMessage)
io.WriteString(w, "HELLO")
w.Close()
ws.SetReadDeadline(time.Now().Add(1 * time.Second))
op, r, err := ws.NextReader()
if err != nil {
t.Fatalf("NextReader: %v", err)
}
if op != websocket.TextMessage {
t.Fatalf("op=%d, want %d", op, websocket.TextMessage)
if op != TextMessage {
t.Fatalf("op=%d, want %d", op, TextMessage)
}
b, err := ioutil.ReadAll(r)
if err != nil {
Expand All @@ -112,3 +109,132 @@ func TestClientServer(t *testing.T) {
t.Fatalf("message=%s, want %s", b, "HELLO")
}
}

type dialHandler struct {
*testing.T
}

func (t dialHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
ws, err := Upgrade(w, r, nil, 1024, 1024)
if _, ok := err.(HandshakeError); ok {
t.Logf("bad handshake: %v", err)
http.Error(w, "Not a websocket handshake", 400)
return
} else if err != nil {
t.Logf("upgrade error: %v", err)
return
}
defer ws.Close()
for {
mt, p, err := ws.ReadMessage()
if err != nil {
if err != io.EOF {
t.Logf("ReadMessage: %v", err)
}
return
}
if err := ws.WriteMessage(mt, p); err != nil {
t.Logf("WriteMessage: %v", err)
return
}
}
}

func sendRecv(t *testing.T, ws *Conn) {
const message = "Hello World!"
if err := ws.WriteMessage(TextMessage, []byte(message)); err != nil {
t.Fatalf("WriteMessage: %v", err)
}
_, p, err := ws.ReadMessage()
if err != nil {
t.Fatalf("ReadMessage: %v", err)
}
if string(p) != message {
t.Fatalf("message=%s, want %s", p, message)
}
}

func httpToWs(u string) string {
return "ws" + u[len("http"):]
}

func TestDial(t *testing.T) {
s := httptest.NewServer(dialHandler{t})
defer s.Close()
ws, _, err := DefaultDialer.Dial(httpToWs(s.URL), nil)
if err != nil {
t.Fatalf("Dial() returned error %v", err)
}
defer ws.Close()
sendRecv(t, ws)
}

func TestDialTLS(t *testing.T) {
s := httptest.NewTLSServer(dialHandler{t})
defer s.Close()

certs := x509.NewCertPool()
for _, c := range s.TLS.Certificates {
roots, err := x509.ParseCertificates(c.Certificate[len(c.Certificate)-1])
if err != nil {
t.Fatalf("error parsing server's root cert: %v", err)
}
for _, root := range roots {
certs.AddCert(root)
}
}

u, _ := url.Parse(s.URL)
d := &Dialer{
NetDial: func(network, addr string) (net.Conn, error) { return net.Dial(network, u.Host) },
TLSClientConfig: &tls.Config{RootCAs: certs},
}
ws, _, err := d.Dial("wss://example.com/", nil)
if err != nil {
t.Fatalf("Dial() returned error %v", err)
}
defer ws.Close()
sendRecv(t, ws)
}

func TestDialTLSBadCert(t *testing.T) {
s := httptest.NewTLSServer(dialHandler{t})
defer s.Close()
_, _, err := DefaultDialer.Dial(httpToWs(s.URL), nil)
if err == nil {
t.Fatalf("Dial() did not return error")
}
}

func TestDialTLSNoVerify(t *testing.T) {
s := httptest.NewTLSServer(dialHandler{t})
defer s.Close()
d := &Dialer{TLSClientConfig: &tls.Config{InsecureSkipVerify: true}}
ws, _, err := d.Dial(httpToWs(s.URL), nil)
if err != nil {
t.Fatalf("Dial() returned error %v", err)
}
defer ws.Close()
sendRecv(t, ws)
}

func TestDialTimeout(t *testing.T) {
s := httptest.NewServer(dialHandler{t})
defer s.Close()
d := &Dialer{
HandshakeTimeout: -1,
}
_, _, err := d.Dial(httpToWs(s.URL), nil)
if err == nil {
t.Fatalf("Dial() did not return error")
}
}

func TestDialBadScheme(t *testing.T) {
s := httptest.NewServer(dialHandler{t})
defer s.Close()
_, _, err := DefaultDialer.Dial(s.URL, nil)
if err == nil {
t.Fatalf("Dial() did not return error")
}
}

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