Vendor main dependencies.

vendor/github.com/gorilla/websocket/client.go

@@ -0,0 +1,420 @@
+// Copyright 2013 The Gorilla WebSocket Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package websocket
+
+import (
+	"bufio"
+	"bytes"
+	"crypto/tls"
+	"encoding/base64"
+	"errors"
+	"io"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+// ErrBadHandshake is returned when the server response to opening handshake is
+// invalid.
+var ErrBadHandshake = errors.New("websocket: bad handshake")
+
+var errInvalidCompression = errors.New("websocket: invalid compression negotiation")
+
+// 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 (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.
+//
+// Deprecated: Use Dialer instead.
+func NewClient(netConn net.Conn, u *url.URL, requestHeader http.Header, readBufSize, writeBufSize int) (c *Conn, response *http.Response, err error) {
+	d := Dialer{
+		ReadBufferSize:  readBufSize,
+		WriteBufferSize: writeBufSize,
+		NetDial: func(net, addr string) (net.Conn, error) {
+			return netConn, nil
+		},
+	}
+	return d.Dial(u.String(), requestHeader)
+}
+
+// A Dialer contains options for connecting to WebSocket server.
+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)
+
+	// Proxy specifies a function to return a proxy for a given
+	// Request. If the function returns a non-nil error, the
+	// request is aborted with the provided error.
+	// If Proxy is nil or returns a nil *URL, no proxy is used.
+	Proxy func(*http.Request) (*url.URL, 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
+
+	// Subprotocols specifies the client's requested subprotocols.
+	Subprotocols []string
+
+	// EnableCompression specifies if the client should attempt to negotiate
+	// per message compression (RFC 7692). Setting this value to true does not
+	// guarantee that compression will be supported. Currently only "no context
+	// takeover" modes are supported.
+	EnableCompression bool
+
+	// Jar specifies the cookie jar.
+	// If Jar is nil, cookies are not sent in requests and ignored
+	// in responses.
+	Jar http.CookieJar
+}
+
+var errMalformedURL = errors.New("malformed ws or wss URL")
+
+// parseURL parses the URL.
+//
+// This function is a replacement for the standard library url.Parse function.
+// In Go 1.4 and earlier, url.Parse loses information from the path.
+func parseURL(s string) (*url.URL, error) {
+	// From the RFC:
+	//
+	// ws-URI = "ws:" "//" host [ ":" port ] path [ "?" query ]
+	// wss-URI = "wss:" "//" host [ ":" port ] path [ "?" query ]
+	var u url.URL
+	switch {
+	case strings.HasPrefix(s, "ws://"):
+		u.Scheme = "ws"
+		s = s[len("ws://"):]
+	case strings.HasPrefix(s, "wss://"):
+		u.Scheme = "wss"
+		s = s[len("wss://"):]
+	default:
+		return nil, errMalformedURL
+	}
+
+	if i := strings.Index(s, "?"); i >= 0 {
+		u.RawQuery = s[i+1:]
+		s = s[:i]
+	}
+
+	if i := strings.Index(s, "/"); i >= 0 {
+		u.Opaque = s[i:]
+		s = s[:i]
+	} else {
+		u.Opaque = "/"
+	}
+
+	u.Host = s
+
+	if strings.Contains(u.Host, "@") {
+		// Don't bother parsing user information because user information is
+		// not allowed in websocket URIs.
+		return nil, errMalformedURL
+	}
+
+	return &u, nil
+}
+
+func hostPortNoPort(u *url.URL) (hostPort, hostNoPort string) {
+	hostPort = u.Host
+	hostNoPort = u.Host
+	if i := strings.LastIndex(u.Host, ":"); i > strings.LastIndex(u.Host, "]") {
+		hostNoPort = hostNoPort[:i]
+	} else {
+		switch u.Scheme {
+		case "wss":
+			hostPort += ":443"
+		case "https":
+			hostPort += ":443"
+		default:
+			hostPort += ":80"
+		}
+	}
+	return hostPort, hostNoPort
+}
+
+// DefaultDialer is a dialer with all fields set to the default zero values.
+var DefaultDialer = &Dialer{
+	Proxy: http.ProxyFromEnvironment,
+}
+
+// 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,
+// etcetera. The response body may not contain the entire response and does not
+// need to be closed by the application.
+func (d *Dialer) Dial(urlStr string, requestHeader http.Header) (*Conn, *http.Response, error) {
+
+	if d == nil {
+		d = &Dialer{
+			Proxy: http.ProxyFromEnvironment,
+		}
+	}
+
+	challengeKey, err := generateChallengeKey()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	u, err := parseURL(urlStr)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	switch u.Scheme {
+	case "ws":
+		u.Scheme = "http"
+	case "wss":
+		u.Scheme = "https"
+	default:
+		return nil, nil, errMalformedURL
+	}
+
+	if u.User != nil {
+		// User name and password are not allowed in websocket URIs.
+		return nil, nil, errMalformedURL
+	}
+
+	req := &http.Request{
+		Method:     "GET",
+		URL:        u,
+		Proto:      "HTTP/1.1",
+		ProtoMajor: 1,
+		ProtoMinor: 1,
+		Header:     make(http.Header),
+		Host:       u.Host,
+	}
+
+	// Set the cookies present in the cookie jar of the dialer
+	if d.Jar != nil {
+		for _, cookie := range d.Jar.Cookies(u) {
+			req.AddCookie(cookie)
+		}
+	}
+
+	// Set the request headers using the capitalization for names and values in
+	// RFC examples. Although the capitalization shouldn't matter, there are
+	// servers that depend on it. The Header.Set method is not used because the
+	// method canonicalizes the header names.
+	req.Header["Upgrade"] = []string{"websocket"}
+	req.Header["Connection"] = []string{"Upgrade"}
+	req.Header["Sec-WebSocket-Key"] = []string{challengeKey}
+	req.Header["Sec-WebSocket-Version"] = []string{"13"}
+	if len(d.Subprotocols) > 0 {
+		req.Header["Sec-WebSocket-Protocol"] = []string{strings.Join(d.Subprotocols, ", ")}
+	}
+	for k, vs := range requestHeader {
+		switch {
+		case k == "Host":
+			if len(vs) > 0 {
+				req.Host = vs[0]
+			}
+		case k == "Upgrade" ||
+			k == "Connection" ||
+			k == "Sec-Websocket-Key" ||
+			k == "Sec-Websocket-Version" ||
+			k == "Sec-Websocket-Extensions" ||
+			(k == "Sec-Websocket-Protocol" && len(d.Subprotocols) > 0):
+			return nil, nil, errors.New("websocket: duplicate header not allowed: " + k)
+		default:
+			req.Header[k] = vs
+		}
+	}
+
+	if d.EnableCompression {
+		req.Header.Set("Sec-Websocket-Extensions", "permessage-deflate; server_no_context_takeover; client_no_context_takeover")
+	}
+
+	hostPort, hostNoPort := hostPortNoPort(u)
+
+	var proxyURL *url.URL
+	// Check wether the proxy method has been configured
+	if d.Proxy != nil {
+		proxyURL, err = d.Proxy(req)
+	}
+	if err != nil {
+		return nil, nil, err
+	}
+
+	var targetHostPort string
+	if proxyURL != nil {
+		targetHostPort, _ = hostPortNoPort(proxyURL)
+	} else {
+		targetHostPort = hostPort
+	}
+
+	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", targetHostPort)
+	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 proxyURL != nil {
+		connectHeader := make(http.Header)
+		if user := proxyURL.User; user != nil {
+			proxyUser := user.Username()
+			if proxyPassword, passwordSet := user.Password(); passwordSet {
+				credential := base64.StdEncoding.EncodeToString([]byte(proxyUser + ":" + proxyPassword))
+				connectHeader.Set("Proxy-Authorization", "Basic "+credential)
+			}
+		}
+		connectReq := &http.Request{
+			Method: "CONNECT",
+			URL:    &url.URL{Opaque: hostPort},
+			Host:   hostPort,
+			Header: connectHeader,
+		}
+
+		connectReq.Write(netConn)
+
+		// Read response.
+		// Okay to use and discard buffered reader here, because
+		// TLS server will not speak until spoken to.
+		br := bufio.NewReader(netConn)
+		resp, err := http.ReadResponse(br, connectReq)
+		if err != nil {
+			return nil, nil, err
+		}
+		if resp.StatusCode != 200 {
+			f := strings.SplitN(resp.Status, " ", 2)
+			return nil, nil, errors.New(f[1])
+		}
+	}
+
+	if u.Scheme == "https" {
+		cfg := cloneTLSConfig(d.TLSClientConfig)
+		if cfg.ServerName == "" {
+			cfg.ServerName = hostNoPort
+		}
+		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
+			}
+		}
+	}
+
+	conn := newConn(netConn, false, d.ReadBufferSize, d.WriteBufferSize)
+
+	if err := req.Write(netConn); err != nil {
+		return nil, nil, err
+	}
+
+	resp, err := http.ReadResponse(conn.br, req)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	if d.Jar != nil {
+		if rc := resp.Cookies(); len(rc) > 0 {
+			d.Jar.SetCookies(u, rc)
+		}
+	}
+
+	if resp.StatusCode != 101 ||
+		!strings.EqualFold(resp.Header.Get("Upgrade"), "websocket") ||
+		!strings.EqualFold(resp.Header.Get("Connection"), "upgrade") ||
+		resp.Header.Get("Sec-Websocket-Accept") != computeAcceptKey(challengeKey) {
+		// Before closing the network connection on return from this
+		// function, slurp up some of the response to aid application
+		// debugging.
+		buf := make([]byte, 1024)
+		n, _ := io.ReadFull(resp.Body, buf)
+		resp.Body = ioutil.NopCloser(bytes.NewReader(buf[:n]))
+		return nil, resp, ErrBadHandshake
+	}
+
+	for _, ext := range parseExtensions(req.Header) {
+		if ext[""] != "permessage-deflate" {
+			continue
+		}
+		_, snct := ext["server_no_context_takeover"]
+		_, cnct := ext["client_no_context_takeover"]
+		if !snct || !cnct {
+			return nil, resp, errInvalidCompression
+		}
+		conn.newCompressionWriter = compressNoContextTakeover
+		conn.newDecompressionReader = decompressNoContextTakeover
+		break
+	}
+
+	resp.Body = ioutil.NopCloser(bytes.NewReader([]byte{}))
+	conn.subprotocol = resp.Header.Get("Sec-Websocket-Protocol")
+
+	netConn.SetDeadline(time.Time{})
+	netConn = nil // to avoid close in defer.
+	return conn, resp, nil
+}
+
+// cloneTLSConfig clones all public fields except the fields
+// SessionTicketsDisabled and SessionTicketKey. This avoids copying the
+// sync.Mutex in the sync.Once and makes it safe to call cloneTLSConfig on a
+// config in active use.
+func cloneTLSConfig(cfg *tls.Config) *tls.Config {
+	if cfg == nil {
+		return &tls.Config{}
+	}
+	return &tls.Config{
+		Rand:                     cfg.Rand,
+		Time:                     cfg.Time,
+		Certificates:             cfg.Certificates,
+		NameToCertificate:        cfg.NameToCertificate,
+		GetCertificate:           cfg.GetCertificate,
+		RootCAs:                  cfg.RootCAs,
+		NextProtos:               cfg.NextProtos,
+		ServerName:               cfg.ServerName,
+		ClientAuth:               cfg.ClientAuth,
+		ClientCAs:                cfg.ClientCAs,
+		InsecureSkipVerify:       cfg.InsecureSkipVerify,
+		CipherSuites:             cfg.CipherSuites,
+		PreferServerCipherSuites: cfg.PreferServerCipherSuites,
+		ClientSessionCache:       cfg.ClientSessionCache,
+		MinVersion:               cfg.MinVersion,
+		MaxVersion:               cfg.MaxVersion,
+		CurvePreferences:         cfg.CurvePreferences,
+	}
+}