Naive implementation that always return min value

2019-12-27 15:38:12 +01:00
parent 6da3e5cd02
commit 83056fb0f1
72 changed files with 8284 additions and 0 deletions
--- a/vendor/golang.org/x/net/AUTHORS
+++ b/vendor/golang.org/x/net/AUTHORS
@@ -0,0 +1,3 @@
+# This source code refers to The Go Authors for copyright purposes.
+# The master list of authors is in the main Go distribution,
+# visible at http://tip.golang.org/AUTHORS.
--- a/vendor/golang.org/x/net/CONTRIBUTORS
+++ b/vendor/golang.org/x/net/CONTRIBUTORS
@@ -0,0 +1,3 @@
+# This source code was written by the Go contributors.
+# The master list of contributors is in the main Go distribution,
+# visible at http://tip.golang.org/CONTRIBUTORS.
--- a/vendor/golang.org/x/net/LICENSE
+++ b/vendor/golang.org/x/net/LICENSE
@@ -0,0 +1,27 @@
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
--- a/vendor/golang.org/x/net/PATENTS
+++ b/vendor/golang.org/x/net/PATENTS
@@ -0,0 +1,22 @@
+Additional IP Rights Grant (Patents)
+
+"This implementation" means the copyrightable works distributed by
+Google as part of the Go project.
+
+Google hereby grants to You a perpetual, worldwide, non-exclusive,
+no-charge, royalty-free, irrevocable (except as stated in this section)
+patent license to make, have made, use, offer to sell, sell, import,
+transfer and otherwise run, modify and propagate the contents of this
+implementation of Go, where such license applies only to those patent
+claims, both currently owned or controlled by Google and acquired in
+the future, licensable by Google that are necessarily infringed by this
+implementation of Go.  This grant does not include claims that would be
+infringed only as a consequence of further modification of this
+implementation.  If you or your agent or exclusive licensee institute or
+order or agree to the institution of patent litigation against any
+entity (including a cross-claim or counterclaim in a lawsuit) alleging
+that this implementation of Go or any code incorporated within this
+implementation of Go constitutes direct or contributory patent
+infringement, or inducement of patent infringement, then any patent
+rights granted to you under this License for this implementation of Go
+shall terminate as of the date such litigation is filed.
--- a/vendor/golang.org/x/net/internal/socks/client.go
+++ b/vendor/golang.org/x/net/internal/socks/client.go
@@ -0,0 +1,168 @@
+// Copyright 2018 The Go 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 socks
+
+import (
+	"context"
+	"errors"
+	"io"
+	"net"
+	"strconv"
+	"time"
+)
+
+var (
+	noDeadline   = time.Time{}
+	aLongTimeAgo = time.Unix(1, 0)
+)
+
+func (d *Dialer) connect(ctx context.Context, c net.Conn, address string) (_ net.Addr, ctxErr error) {
+	host, port, err := splitHostPort(address)
+	if err != nil {
+		return nil, err
+	}
+	if deadline, ok := ctx.Deadline(); ok && !deadline.IsZero() {
+		c.SetDeadline(deadline)
+		defer c.SetDeadline(noDeadline)
+	}
+	if ctx != context.Background() {
+		errCh := make(chan error, 1)
+		done := make(chan struct{})
+		defer func() {
+			close(done)
+			if ctxErr == nil {
+				ctxErr = <-errCh
+			}
+		}()
+		go func() {
+			select {
+			case <-ctx.Done():
+				c.SetDeadline(aLongTimeAgo)
+				errCh <- ctx.Err()
+			case <-done:
+				errCh <- nil
+			}
+		}()
+	}
+
+	b := make([]byte, 0, 6+len(host)) // the size here is just an estimate
+	b = append(b, Version5)
+	if len(d.AuthMethods) == 0 || d.Authenticate == nil {
+		b = append(b, 1, byte(AuthMethodNotRequired))
+	} else {
+		ams := d.AuthMethods
+		if len(ams) > 255 {
+			return nil, errors.New("too many authentication methods")
+		}
+		b = append(b, byte(len(ams)))
+		for _, am := range ams {
+			b = append(b, byte(am))
+		}
+	}
+	if _, ctxErr = c.Write(b); ctxErr != nil {
+		return
+	}
+
+	if _, ctxErr = io.ReadFull(c, b[:2]); ctxErr != nil {
+		return
+	}
+	if b[0] != Version5 {
+		return nil, errors.New("unexpected protocol version " + strconv.Itoa(int(b[0])))
+	}
+	am := AuthMethod(b[1])
+	if am == AuthMethodNoAcceptableMethods {
+		return nil, errors.New("no acceptable authentication methods")
+	}
+	if d.Authenticate != nil {
+		if ctxErr = d.Authenticate(ctx, c, am); ctxErr != nil {
+			return
+		}
+	}
+
+	b = b[:0]
+	b = append(b, Version5, byte(d.cmd), 0)
+	if ip := net.ParseIP(host); ip != nil {
+		if ip4 := ip.To4(); ip4 != nil {
+			b = append(b, AddrTypeIPv4)
+			b = append(b, ip4...)
+		} else if ip6 := ip.To16(); ip6 != nil {
+			b = append(b, AddrTypeIPv6)
+			b = append(b, ip6...)
+		} else {
+			return nil, errors.New("unknown address type")
+		}
+	} else {
+		if len(host) > 255 {
+			return nil, errors.New("FQDN too long")
+		}
+		b = append(b, AddrTypeFQDN)
+		b = append(b, byte(len(host)))
+		b = append(b, host...)
+	}
+	b = append(b, byte(port>>8), byte(port))
+	if _, ctxErr = c.Write(b); ctxErr != nil {
+		return
+	}
+
+	if _, ctxErr = io.ReadFull(c, b[:4]); ctxErr != nil {
+		return
+	}
+	if b[0] != Version5 {
+		return nil, errors.New("unexpected protocol version " + strconv.Itoa(int(b[0])))
+	}
+	if cmdErr := Reply(b[1]); cmdErr != StatusSucceeded {
+		return nil, errors.New("unknown error " + cmdErr.String())
+	}
+	if b[2] != 0 {
+		return nil, errors.New("non-zero reserved field")
+	}
+	l := 2
+	var a Addr
+	switch b[3] {
+	case AddrTypeIPv4:
+		l += net.IPv4len
+		a.IP = make(net.IP, net.IPv4len)
+	case AddrTypeIPv6:
+		l += net.IPv6len
+		a.IP = make(net.IP, net.IPv6len)
+	case AddrTypeFQDN:
+		if _, err := io.ReadFull(c, b[:1]); err != nil {
+			return nil, err
+		}
+		l += int(b[0])
+	default:
+		return nil, errors.New("unknown address type " + strconv.Itoa(int(b[3])))
+	}
+	if cap(b) < l {
+		b = make([]byte, l)
+	} else {
+		b = b[:l]
+	}
+	if _, ctxErr = io.ReadFull(c, b); ctxErr != nil {
+		return
+	}
+	if a.IP != nil {
+		copy(a.IP, b)
+	} else {
+		a.Name = string(b[:len(b)-2])
+	}
+	a.Port = int(b[len(b)-2])<<8 | int(b[len(b)-1])
+	return &a, nil
+}
+
+func splitHostPort(address string) (string, int, error) {
+	host, port, err := net.SplitHostPort(address)
+	if err != nil {
+		return "", 0, err
+	}
+	portnum, err := strconv.Atoi(port)
+	if err != nil {
+		return "", 0, err
+	}
+	if 1 > portnum || portnum > 0xffff {
+		return "", 0, errors.New("port number out of range " + port)
+	}
+	return host, portnum, nil
+}
--- a/vendor/golang.org/x/net/internal/socks/socks.go
+++ b/vendor/golang.org/x/net/internal/socks/socks.go
@@ -0,0 +1,317 @@
+// Copyright 2018 The Go 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 socks provides a SOCKS version 5 client implementation.
+//
+// SOCKS protocol version 5 is defined in RFC 1928.
+// Username/Password authentication for SOCKS version 5 is defined in
+// RFC 1929.
+package socks
+
+import (
+	"context"
+	"errors"
+	"io"
+	"net"
+	"strconv"
+)
+
+// A Command represents a SOCKS command.
+type Command int
+
+func (cmd Command) String() string {
+	switch cmd {
+	case CmdConnect:
+		return "socks connect"
+	case cmdBind:
+		return "socks bind"
+	default:
+		return "socks " + strconv.Itoa(int(cmd))
+	}
+}
+
+// An AuthMethod represents a SOCKS authentication method.
+type AuthMethod int
+
+// A Reply represents a SOCKS command reply code.
+type Reply int
+
+func (code Reply) String() string {
+	switch code {
+	case StatusSucceeded:
+		return "succeeded"
+	case 0x01:
+		return "general SOCKS server failure"
+	case 0x02:
+		return "connection not allowed by ruleset"
+	case 0x03:
+		return "network unreachable"
+	case 0x04:
+		return "host unreachable"
+	case 0x05:
+		return "connection refused"
+	case 0x06:
+		return "TTL expired"
+	case 0x07:
+		return "command not supported"
+	case 0x08:
+		return "address type not supported"
+	default:
+		return "unknown code: " + strconv.Itoa(int(code))
+	}
+}
+
+// Wire protocol constants.
+const (
+	Version5 = 0x05
+
+	AddrTypeIPv4 = 0x01
+	AddrTypeFQDN = 0x03
+	AddrTypeIPv6 = 0x04
+
+	CmdConnect Command = 0x01 // establishes an active-open forward proxy connection
+	cmdBind    Command = 0x02 // establishes a passive-open forward proxy connection
+
+	AuthMethodNotRequired         AuthMethod = 0x00 // no authentication required
+	AuthMethodUsernamePassword    AuthMethod = 0x02 // use username/password
+	AuthMethodNoAcceptableMethods AuthMethod = 0xff // no acceptable authentication methods
+
+	StatusSucceeded Reply = 0x00
+)
+
+// An Addr represents a SOCKS-specific address.
+// Either Name or IP is used exclusively.
+type Addr struct {
+	Name string // fully-qualified domain name
+	IP   net.IP
+	Port int
+}
+
+func (a *Addr) Network() string { return "socks" }
+
+func (a *Addr) String() string {
+	if a == nil {
+		return "<nil>"
+	}
+	port := strconv.Itoa(a.Port)
+	if a.IP == nil {
+		return net.JoinHostPort(a.Name, port)
+	}
+	return net.JoinHostPort(a.IP.String(), port)
+}
+
+// A Conn represents a forward proxy connection.
+type Conn struct {
+	net.Conn
+
+	boundAddr net.Addr
+}
+
+// BoundAddr returns the address assigned by the proxy server for
+// connecting to the command target address from the proxy server.
+func (c *Conn) BoundAddr() net.Addr {
+	if c == nil {
+		return nil
+	}
+	return c.boundAddr
+}
+
+// A Dialer holds SOCKS-specific options.
+type Dialer struct {
+	cmd          Command // either CmdConnect or cmdBind
+	proxyNetwork string  // network between a proxy server and a client
+	proxyAddress string  // proxy server address
+
+	// ProxyDial specifies the optional dial function for
+	// establishing the transport connection.
+	ProxyDial func(context.Context, string, string) (net.Conn, error)
+
+	// AuthMethods specifies the list of request authentication
+	// methods.
+	// If empty, SOCKS client requests only AuthMethodNotRequired.
+	AuthMethods []AuthMethod
+
+	// Authenticate specifies the optional authentication
+	// function. It must be non-nil when AuthMethods is not empty.
+	// It must return an error when the authentication is failed.
+	Authenticate func(context.Context, io.ReadWriter, AuthMethod) error
+}
+
+// DialContext connects to the provided address on the provided
+// network.
+//
+// The returned error value may be a net.OpError. When the Op field of
+// net.OpError contains "socks", the Source field contains a proxy
+// server address and the Addr field contains a command target
+// address.
+//
+// See func Dial of the net package of standard library for a
+// description of the network and address parameters.
+func (d *Dialer) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
+	if err := d.validateTarget(network, address); err != nil {
+		proxy, dst, _ := d.pathAddrs(address)
+		return nil, &net.OpError{Op: d.cmd.String(), Net: network, Source: proxy, Addr: dst, Err: err}
+	}
+	if ctx == nil {
+		proxy, dst, _ := d.pathAddrs(address)
+		return nil, &net.OpError{Op: d.cmd.String(), Net: network, Source: proxy, Addr: dst, Err: errors.New("nil context")}
+	}
+	var err error
+	var c net.Conn
+	if d.ProxyDial != nil {
+		c, err = d.ProxyDial(ctx, d.proxyNetwork, d.proxyAddress)
+	} else {
+		var dd net.Dialer
+		c, err = dd.DialContext(ctx, d.proxyNetwork, d.proxyAddress)
+	}
+	if err != nil {
+		proxy, dst, _ := d.pathAddrs(address)
+		return nil, &net.OpError{Op: d.cmd.String(), Net: network, Source: proxy, Addr: dst, Err: err}
+	}
+	a, err := d.connect(ctx, c, address)
+	if err != nil {
+		c.Close()
+		proxy, dst, _ := d.pathAddrs(address)
+		return nil, &net.OpError{Op: d.cmd.String(), Net: network, Source: proxy, Addr: dst, Err: err}
+	}
+	return &Conn{Conn: c, boundAddr: a}, nil
+}
+
+// DialWithConn initiates a connection from SOCKS server to the target
+// network and address using the connection c that is already
+// connected to the SOCKS server.
+//
+// It returns the connection's local address assigned by the SOCKS
+// server.
+func (d *Dialer) DialWithConn(ctx context.Context, c net.Conn, network, address string) (net.Addr, error) {
+	if err := d.validateTarget(network, address); err != nil {
+		proxy, dst, _ := d.pathAddrs(address)
+		return nil, &net.OpError{Op: d.cmd.String(), Net: network, Source: proxy, Addr: dst, Err: err}
+	}
+	if ctx == nil {
+		proxy, dst, _ := d.pathAddrs(address)
+		return nil, &net.OpError{Op: d.cmd.String(), Net: network, Source: proxy, Addr: dst, Err: errors.New("nil context")}
+	}
+	a, err := d.connect(ctx, c, address)
+	if err != nil {
+		proxy, dst, _ := d.pathAddrs(address)
+		return nil, &net.OpError{Op: d.cmd.String(), Net: network, Source: proxy, Addr: dst, Err: err}
+	}
+	return a, nil
+}
+
+// Dial connects to the provided address on the provided network.
+//
+// Unlike DialContext, it returns a raw transport connection instead
+// of a forward proxy connection.
+//
+// Deprecated: Use DialContext or DialWithConn instead.
+func (d *Dialer) Dial(network, address string) (net.Conn, error) {
+	if err := d.validateTarget(network, address); err != nil {
+		proxy, dst, _ := d.pathAddrs(address)
+		return nil, &net.OpError{Op: d.cmd.String(), Net: network, Source: proxy, Addr: dst, Err: err}
+	}
+	var err error
+	var c net.Conn
+	if d.ProxyDial != nil {
+		c, err = d.ProxyDial(context.Background(), d.proxyNetwork, d.proxyAddress)
+	} else {
+		c, err = net.Dial(d.proxyNetwork, d.proxyAddress)
+	}
+	if err != nil {
+		proxy, dst, _ := d.pathAddrs(address)
+		return nil, &net.OpError{Op: d.cmd.String(), Net: network, Source: proxy, Addr: dst, Err: err}
+	}
+	if _, err := d.DialWithConn(context.Background(), c, network, address); err != nil {
+		c.Close()
+		return nil, err
+	}
+	return c, nil
+}
+
+func (d *Dialer) validateTarget(network, address string) error {
+	switch network {
+	case "tcp", "tcp6", "tcp4":
+	default:
+		return errors.New("network not implemented")
+	}
+	switch d.cmd {
+	case CmdConnect, cmdBind:
+	default:
+		return errors.New("command not implemented")
+	}
+	return nil
+}
+
+func (d *Dialer) pathAddrs(address string) (proxy, dst net.Addr, err error) {
+	for i, s := range []string{d.proxyAddress, address} {
+		host, port, err := splitHostPort(s)
+		if err != nil {
+			return nil, nil, err
+		}
+		a := &Addr{Port: port}
+		a.IP = net.ParseIP(host)
+		if a.IP == nil {
+			a.Name = host
+		}
+		if i == 0 {
+			proxy = a
+		} else {
+			dst = a
+		}
+	}
+	return
+}
+
+// NewDialer returns a new Dialer that dials through the provided
+// proxy server's network and address.
+func NewDialer(network, address string) *Dialer {
+	return &Dialer{proxyNetwork: network, proxyAddress: address, cmd: CmdConnect}
+}
+
+const (
+	authUsernamePasswordVersion = 0x01
+	authStatusSucceeded         = 0x00
+)
+
+// UsernamePassword are the credentials for the username/password
+// authentication method.
+type UsernamePassword struct {
+	Username string
+	Password string
+}
+
+// Authenticate authenticates a pair of username and password with the
+// proxy server.
+func (up *UsernamePassword) Authenticate(ctx context.Context, rw io.ReadWriter, auth AuthMethod) error {
+	switch auth {
+	case AuthMethodNotRequired:
+		return nil
+	case AuthMethodUsernamePassword:
+		if len(up.Username) == 0 || len(up.Username) > 255 || len(up.Password) == 0 || len(up.Password) > 255 {
+			return errors.New("invalid username/password")
+		}
+		b := []byte{authUsernamePasswordVersion}
+		b = append(b, byte(len(up.Username)))
+		b = append(b, up.Username...)
+		b = append(b, byte(len(up.Password)))
+		b = append(b, up.Password...)
+		// TODO(mikio): handle IO deadlines and cancelation if
+		// necessary
+		if _, err := rw.Write(b); err != nil {
+			return err
+		}
+		if _, err := io.ReadFull(rw, b[:2]); err != nil {
+			return err
+		}
+		if b[0] != authUsernamePasswordVersion {
+			return errors.New("invalid username/password version")
+		}
+		if b[1] != authStatusSucceeded {
+			return errors.New("username/password authentication failed")
+		}
+		return nil
+	}
+	return errors.New("unsupported authentication method " + strconv.Itoa(int(auth)))
+}
--- a/vendor/golang.org/x/net/proxy/dial.go
+++ b/vendor/golang.org/x/net/proxy/dial.go
@@ -0,0 +1,54 @@
+// Copyright 2019 The Go 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 proxy
+
+import (
+	"context"
+	"net"
+)
+
+// A ContextDialer dials using a context.
+type ContextDialer interface {
+	DialContext(ctx context.Context, network, address string) (net.Conn, error)
+}
+
+// Dial works like DialContext on net.Dialer but using a dialer returned by FromEnvironment.
+//
+// The passed ctx is only used for returning the Conn, not the lifetime of the Conn.
+//
+// Custom dialers (registered via RegisterDialerType) that do not implement ContextDialer
+// can leak a goroutine for as long as it takes the underlying Dialer implementation to timeout.
+//
+// A Conn returned from a successful Dial after the context has been cancelled will be immediately closed.
+func Dial(ctx context.Context, network, address string) (net.Conn, error) {
+	d := FromEnvironment()
+	if xd, ok := d.(ContextDialer); ok {
+		return xd.DialContext(ctx, network, address)
+	}
+	return dialContext(ctx, d, network, address)
+}
+
+// WARNING: this can leak a goroutine for as long as the underlying Dialer implementation takes to timeout
+// A Conn returned from a successful Dial after the context has been cancelled will be immediately closed.
+func dialContext(ctx context.Context, d Dialer, network, address string) (net.Conn, error) {
+	var (
+		conn net.Conn
+		done = make(chan struct{}, 1)
+		err  error
+	)
+	go func() {
+		conn, err = d.Dial(network, address)
+		close(done)
+		if conn != nil && ctx.Err() != nil {
+			conn.Close()
+		}
+	}()
+	select {
+	case <-ctx.Done():
+		err = ctx.Err()
+	case <-done:
+	}
+	return conn, err
+}
--- a/vendor/golang.org/x/net/proxy/direct.go
+++ b/vendor/golang.org/x/net/proxy/direct.go
@@ -0,0 +1,31 @@
+// Copyright 2011 The Go 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 proxy
+
+import (
+	"context"
+	"net"
+)
+
+type direct struct{}
+
+// Direct implements Dialer by making network connections directly using net.Dial or net.DialContext.
+var Direct = direct{}
+
+var (
+	_ Dialer        = Direct
+	_ ContextDialer = Direct
+)
+
+// Dial directly invokes net.Dial with the supplied parameters.
+func (direct) Dial(network, addr string) (net.Conn, error) {
+	return net.Dial(network, addr)
+}
+
+// DialContext instantiates a net.Dialer and invokes its DialContext receiver with the supplied parameters.
+func (direct) DialContext(ctx context.Context, network, addr string) (net.Conn, error) {
+	var d net.Dialer
+	return d.DialContext(ctx, network, addr)
+}
--- a/vendor/golang.org/x/net/proxy/per_host.go
+++ b/vendor/golang.org/x/net/proxy/per_host.go
@@ -0,0 +1,155 @@
+// Copyright 2011 The Go 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 proxy
+
+import (
+	"context"
+	"net"
+	"strings"
+)
+
+// A PerHost directs connections to a default Dialer unless the host name
+// requested matches one of a number of exceptions.
+type PerHost struct {
+	def, bypass Dialer
+
+	bypassNetworks []*net.IPNet
+	bypassIPs      []net.IP
+	bypassZones    []string
+	bypassHosts    []string
+}
+
+// NewPerHost returns a PerHost Dialer that directs connections to either
+// defaultDialer or bypass, depending on whether the connection matches one of
+// the configured rules.
+func NewPerHost(defaultDialer, bypass Dialer) *PerHost {
+	return &PerHost{
+		def:    defaultDialer,
+		bypass: bypass,
+	}
+}
+
+// Dial connects to the address addr on the given network through either
+// defaultDialer or bypass.
+func (p *PerHost) Dial(network, addr string) (c net.Conn, err error) {
+	host, _, err := net.SplitHostPort(addr)
+	if err != nil {
+		return nil, err
+	}
+
+	return p.dialerForRequest(host).Dial(network, addr)
+}
+
+// DialContext connects to the address addr on the given network through either
+// defaultDialer or bypass.
+func (p *PerHost) DialContext(ctx context.Context, network, addr string) (c net.Conn, err error) {
+	host, _, err := net.SplitHostPort(addr)
+	if err != nil {
+		return nil, err
+	}
+	d := p.dialerForRequest(host)
+	if x, ok := d.(ContextDialer); ok {
+		return x.DialContext(ctx, network, addr)
+	}
+	return dialContext(ctx, d, network, addr)
+}
+
+func (p *PerHost) dialerForRequest(host string) Dialer {
+	if ip := net.ParseIP(host); ip != nil {
+		for _, net := range p.bypassNetworks {
+			if net.Contains(ip) {
+				return p.bypass
+			}
+		}
+		for _, bypassIP := range p.bypassIPs {
+			if bypassIP.Equal(ip) {
+				return p.bypass
+			}
+		}
+		return p.def
+	}
+
+	for _, zone := range p.bypassZones {
+		if strings.HasSuffix(host, zone) {
+			return p.bypass
+		}
+		if host == zone[1:] {
+			// For a zone ".example.com", we match "example.com"
+			// too.
+			return p.bypass
+		}
+	}
+	for _, bypassHost := range p.bypassHosts {
+		if bypassHost == host {
+			return p.bypass
+		}
+	}
+	return p.def
+}
+
+// AddFromString parses a string that contains comma-separated values
+// specifying hosts that should use the bypass proxy. Each value is either an
+// IP address, a CIDR range, a zone (*.example.com) or a host name
+// (localhost). A best effort is made to parse the string and errors are
+// ignored.
+func (p *PerHost) AddFromString(s string) {
+	hosts := strings.Split(s, ",")
+	for _, host := range hosts {
+		host = strings.TrimSpace(host)
+		if len(host) == 0 {
+			continue
+		}
+		if strings.Contains(host, "/") {
+			// We assume that it's a CIDR address like 127.0.0.0/8
+			if _, net, err := net.ParseCIDR(host); err == nil {
+				p.AddNetwork(net)
+			}
+			continue
+		}
+		if ip := net.ParseIP(host); ip != nil {
+			p.AddIP(ip)
+			continue
+		}
+		if strings.HasPrefix(host, "*.") {
+			p.AddZone(host[1:])
+			continue
+		}
+		p.AddHost(host)
+	}
+}
+
+// AddIP specifies an IP address that will use the bypass proxy. Note that
+// this will only take effect if a literal IP address is dialed. A connection
+// to a named host will never match an IP.
+func (p *PerHost) AddIP(ip net.IP) {
+	p.bypassIPs = append(p.bypassIPs, ip)
+}
+
+// AddNetwork specifies an IP range that will use the bypass proxy. Note that
+// this will only take effect if a literal IP address is dialed. A connection
+// to a named host will never match.
+func (p *PerHost) AddNetwork(net *net.IPNet) {
+	p.bypassNetworks = append(p.bypassNetworks, net)
+}
+
+// AddZone specifies a DNS suffix that will use the bypass proxy. A zone of
+// "example.com" matches "example.com" and all of its subdomains.
+func (p *PerHost) AddZone(zone string) {
+	if strings.HasSuffix(zone, ".") {
+		zone = zone[:len(zone)-1]
+	}
+	if !strings.HasPrefix(zone, ".") {
+		zone = "." + zone
+	}
+	p.bypassZones = append(p.bypassZones, zone)
+}
+
+// AddHost specifies a host name that will use the bypass proxy.
+func (p *PerHost) AddHost(host string) {
+	if strings.HasSuffix(host, ".") {
+		host = host[:len(host)-1]
+	}
+	p.bypassHosts = append(p.bypassHosts, host)
+}
--- a/vendor/golang.org/x/net/proxy/proxy.go
+++ b/vendor/golang.org/x/net/proxy/proxy.go
@@ -0,0 +1,149 @@
+// Copyright 2011 The Go 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 proxy provides support for a variety of protocols to proxy network
+// data.
+package proxy // import "golang.org/x/net/proxy"
+
+import (
+	"errors"
+	"net"
+	"net/url"
+	"os"
+	"sync"
+)
+
+// A Dialer is a means to establish a connection.
+// Custom dialers should also implement ContextDialer.
+type Dialer interface {
+	// Dial connects to the given address via the proxy.
+	Dial(network, addr string) (c net.Conn, err error)
+}
+
+// Auth contains authentication parameters that specific Dialers may require.
+type Auth struct {
+	User, Password string
+}
+
+// FromEnvironment returns the dialer specified by the proxy-related
+// variables in the environment and makes underlying connections
+// directly.
+func FromEnvironment() Dialer {
+	return FromEnvironmentUsing(Direct)
+}
+
+// FromEnvironmentUsing returns the dialer specify by the proxy-related
+// variables in the environment and makes underlying connections
+// using the provided forwarding Dialer (for instance, a *net.Dialer
+// with desired configuration).
+func FromEnvironmentUsing(forward Dialer) Dialer {
+	allProxy := allProxyEnv.Get()
+	if len(allProxy) == 0 {
+		return forward
+	}
+
+	proxyURL, err := url.Parse(allProxy)
+	if err != nil {
+		return forward
+	}
+	proxy, err := FromURL(proxyURL, forward)
+	if err != nil {
+		return forward
+	}
+
+	noProxy := noProxyEnv.Get()
+	if len(noProxy) == 0 {
+		return proxy
+	}
+
+	perHost := NewPerHost(proxy, forward)
+	perHost.AddFromString(noProxy)
+	return perHost
+}
+
+// proxySchemes is a map from URL schemes to a function that creates a Dialer
+// from a URL with such a scheme.
+var proxySchemes map[string]func(*url.URL, Dialer) (Dialer, error)
+
+// RegisterDialerType takes a URL scheme and a function to generate Dialers from
+// a URL with that scheme and a forwarding Dialer. Registered schemes are used
+// by FromURL.
+func RegisterDialerType(scheme string, f func(*url.URL, Dialer) (Dialer, error)) {
+	if proxySchemes == nil {
+		proxySchemes = make(map[string]func(*url.URL, Dialer) (Dialer, error))
+	}
+	proxySchemes[scheme] = f
+}
+
+// FromURL returns a Dialer given a URL specification and an underlying
+// Dialer for it to make network requests.
+func FromURL(u *url.URL, forward Dialer) (Dialer, error) {
+	var auth *Auth
+	if u.User != nil {
+		auth = new(Auth)
+		auth.User = u.User.Username()
+		if p, ok := u.User.Password(); ok {
+			auth.Password = p
+		}
+	}
+
+	switch u.Scheme {
+	case "socks5", "socks5h":
+		addr := u.Hostname()
+		port := u.Port()
+		if port == "" {
+			port = "1080"
+		}
+		return SOCKS5("tcp", net.JoinHostPort(addr, port), auth, forward)
+	}
+
+	// If the scheme doesn't match any of the built-in schemes, see if it
+	// was registered by another package.
+	if proxySchemes != nil {
+		if f, ok := proxySchemes[u.Scheme]; ok {
+			return f(u, forward)
+		}
+	}
+
+	return nil, errors.New("proxy: unknown scheme: " + u.Scheme)
+}
+
+var (
+	allProxyEnv = &envOnce{
+		names: []string{"ALL_PROXY", "all_proxy"},
+	}
+	noProxyEnv = &envOnce{
+		names: []string{"NO_PROXY", "no_proxy"},
+	}
+)
+
+// envOnce looks up an environment variable (optionally by multiple
+// names) once. It mitigates expensive lookups on some platforms
+// (e.g. Windows).
+// (Borrowed from net/http/transport.go)
+type envOnce struct {
+	names []string
+	once  sync.Once
+	val   string
+}
+
+func (e *envOnce) Get() string {
+	e.once.Do(e.init)
+	return e.val
+}
+
+func (e *envOnce) init() {
+	for _, n := range e.names {
+		e.val = os.Getenv(n)
+		if e.val != "" {
+			return
+		}
+	}
+}
+
+// reset is used by tests
+func (e *envOnce) reset() {
+	e.once = sync.Once{}
+	e.val = ""
+}
--- a/vendor/golang.org/x/net/proxy/socks5.go
+++ b/vendor/golang.org/x/net/proxy/socks5.go
@@ -0,0 +1,42 @@
+// Copyright 2011 The Go 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 proxy
+
+import (
+	"context"
+	"net"
+
+	"golang.org/x/net/internal/socks"
+)
+
+// SOCKS5 returns a Dialer that makes SOCKSv5 connections to the given
+// address with an optional username and password.
+// See RFC 1928 and RFC 1929.
+func SOCKS5(network, address string, auth *Auth, forward Dialer) (Dialer, error) {
+	d := socks.NewDialer(network, address)
+	if forward != nil {
+		if f, ok := forward.(ContextDialer); ok {
+			d.ProxyDial = func(ctx context.Context, network string, address string) (net.Conn, error) {
+				return f.DialContext(ctx, network, address)
+			}
+		} else {
+			d.ProxyDial = func(ctx context.Context, network string, address string) (net.Conn, error) {
+				return dialContext(ctx, forward, network, address)
+			}
+		}
+	}
+	if auth != nil {
+		up := socks.UsernamePassword{
+			Username: auth.User,
+			Password: auth.Password,
+		}
+		d.AuthMethods = []socks.AuthMethod{
+			socks.AuthMethodNotRequired,
+			socks.AuthMethodUsernamePassword,
+		}
+		d.Authenticate = up.Authenticate
+	}
+	return d, nil
+}
--- a/vendor/golang.org/x/net/websocket/client.go
+++ b/vendor/golang.org/x/net/websocket/client.go
@@ -0,0 +1,106 @@
+// Copyright 2009 The Go 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"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+)
+
+// DialError is an error that occurs while dialling a websocket server.
+type DialError struct {
+	*Config
+	Err error
+}
+
+func (e *DialError) Error() string {
+	return "websocket.Dial " + e.Config.Location.String() + ": " + e.Err.Error()
+}
+
+// NewConfig creates a new WebSocket config for client connection.
+func NewConfig(server, origin string) (config *Config, err error) {
+	config = new(Config)
+	config.Version = ProtocolVersionHybi13
+	config.Location, err = url.ParseRequestURI(server)
+	if err != nil {
+		return
+	}
+	config.Origin, err = url.ParseRequestURI(origin)
+	if err != nil {
+		return
+	}
+	config.Header = http.Header(make(map[string][]string))
+	return
+}
+
+// NewClient creates a new WebSocket client connection over rwc.
+func NewClient(config *Config, rwc io.ReadWriteCloser) (ws *Conn, err error) {
+	br := bufio.NewReader(rwc)
+	bw := bufio.NewWriter(rwc)
+	err = hybiClientHandshake(config, br, bw)
+	if err != nil {
+		return
+	}
+	buf := bufio.NewReadWriter(br, bw)
+	ws = newHybiClientConn(config, buf, rwc)
+	return
+}
+
+// Dial opens a new client connection to a WebSocket.
+func Dial(url_, protocol, origin string) (ws *Conn, err error) {
+	config, err := NewConfig(url_, origin)
+	if err != nil {
+		return nil, err
+	}
+	if protocol != "" {
+		config.Protocol = []string{protocol}
+	}
+	return DialConfig(config)
+}
+
+var portMap = map[string]string{
+	"ws":  "80",
+	"wss": "443",
+}
+
+func parseAuthority(location *url.URL) string {
+	if _, ok := portMap[location.Scheme]; ok {
+		if _, _, err := net.SplitHostPort(location.Host); err != nil {
+			return net.JoinHostPort(location.Host, portMap[location.Scheme])
+		}
+	}
+	return location.Host
+}
+
+// DialConfig opens a new client connection to a WebSocket with a config.
+func DialConfig(config *Config) (ws *Conn, err error) {
+	var client net.Conn
+	if config.Location == nil {
+		return nil, &DialError{config, ErrBadWebSocketLocation}
+	}
+	if config.Origin == nil {
+		return nil, &DialError{config, ErrBadWebSocketOrigin}
+	}
+	dialer := config.Dialer
+	if dialer == nil {
+		dialer = &net.Dialer{}
+	}
+	client, err = dialWithDialer(dialer, config)
+	if err != nil {
+		goto Error
+	}
+	ws, err = NewClient(config, client)
+	if err != nil {
+		client.Close()
+		goto Error
+	}
+	return
+
+Error:
+	return nil, &DialError{config, err}
+}
--- a/vendor/golang.org/x/net/websocket/dial.go
+++ b/vendor/golang.org/x/net/websocket/dial.go
@@ -0,0 +1,24 @@
+// Copyright 2015 The Go 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 (
+	"crypto/tls"
+	"net"
+)
+
+func dialWithDialer(dialer *net.Dialer, config *Config) (conn net.Conn, err error) {
+	switch config.Location.Scheme {
+	case "ws":
+		conn, err = dialer.Dial("tcp", parseAuthority(config.Location))
+
+	case "wss":
+		conn, err = tls.DialWithDialer(dialer, "tcp", parseAuthority(config.Location), config.TlsConfig)
+
+	default:
+		err = ErrBadScheme
+	}
+	return
+}
--- a/vendor/golang.org/x/net/websocket/hybi.go
+++ b/vendor/golang.org/x/net/websocket/hybi.go
@@ -0,0 +1,583 @@
+// Copyright 2011 The Go 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
+
+// This file implements a protocol of hybi draft.
+// http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-17
+
+import (
+	"bufio"
+	"bytes"
+	"crypto/rand"
+	"crypto/sha1"
+	"encoding/base64"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+const (
+	websocketGUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
+
+	closeStatusNormal            = 1000
+	closeStatusGoingAway         = 1001
+	closeStatusProtocolError     = 1002
+	closeStatusUnsupportedData   = 1003
+	closeStatusFrameTooLarge     = 1004
+	closeStatusNoStatusRcvd      = 1005
+	closeStatusAbnormalClosure   = 1006
+	closeStatusBadMessageData    = 1007
+	closeStatusPolicyViolation   = 1008
+	closeStatusTooBigData        = 1009
+	closeStatusExtensionMismatch = 1010
+
+	maxControlFramePayloadLength = 125
+)
+
+var (
+	ErrBadMaskingKey         = &ProtocolError{"bad masking key"}
+	ErrBadPongMessage        = &ProtocolError{"bad pong message"}
+	ErrBadClosingStatus      = &ProtocolError{"bad closing status"}
+	ErrUnsupportedExtensions = &ProtocolError{"unsupported extensions"}
+	ErrNotImplemented        = &ProtocolError{"not implemented"}
+
+	handshakeHeader = map[string]bool{
+		"Host":                   true,
+		"Upgrade":                true,
+		"Connection":             true,
+		"Sec-Websocket-Key":      true,
+		"Sec-Websocket-Origin":   true,
+		"Sec-Websocket-Version":  true,
+		"Sec-Websocket-Protocol": true,
+		"Sec-Websocket-Accept":   true,
+	}
+)
+
+// A hybiFrameHeader is a frame header as defined in hybi draft.
+type hybiFrameHeader struct {
+	Fin        bool
+	Rsv        [3]bool
+	OpCode     byte
+	Length     int64
+	MaskingKey []byte
+
+	data *bytes.Buffer
+}
+
+// A hybiFrameReader is a reader for hybi frame.
+type hybiFrameReader struct {
+	reader io.Reader
+
+	header hybiFrameHeader
+	pos    int64
+	length int
+}
+
+func (frame *hybiFrameReader) Read(msg []byte) (n int, err error) {
+	n, err = frame.reader.Read(msg)
+	if frame.header.MaskingKey != nil {
+		for i := 0; i < n; i++ {
+			msg[i] = msg[i] ^ frame.header.MaskingKey[frame.pos%4]
+			frame.pos++
+		}
+	}
+	return n, err
+}
+
+func (frame *hybiFrameReader) PayloadType() byte { return frame.header.OpCode }
+
+func (frame *hybiFrameReader) HeaderReader() io.Reader {
+	if frame.header.data == nil {
+		return nil
+	}
+	if frame.header.data.Len() == 0 {
+		return nil
+	}
+	return frame.header.data
+}
+
+func (frame *hybiFrameReader) TrailerReader() io.Reader { return nil }
+
+func (frame *hybiFrameReader) Len() (n int) { return frame.length }
+
+// A hybiFrameReaderFactory creates new frame reader based on its frame type.
+type hybiFrameReaderFactory struct {
+	*bufio.Reader
+}
+
+// NewFrameReader reads a frame header from the connection, and creates new reader for the frame.
+// See Section 5.2 Base Framing protocol for detail.
+// http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-17#section-5.2
+func (buf hybiFrameReaderFactory) NewFrameReader() (frame frameReader, err error) {
+	hybiFrame := new(hybiFrameReader)
+	frame = hybiFrame
+	var header []byte
+	var b byte
+	// First byte. FIN/RSV1/RSV2/RSV3/OpCode(4bits)
+	b, err = buf.ReadByte()
+	if err != nil {
+		return
+	}
+	header = append(header, b)
+	hybiFrame.header.Fin = ((header[0] >> 7) & 1) != 0
+	for i := 0; i < 3; i++ {
+		j := uint(6 - i)
+		hybiFrame.header.Rsv[i] = ((header[0] >> j) & 1) != 0
+	}
+	hybiFrame.header.OpCode = header[0] & 0x0f
+
+	// Second byte. Mask/Payload len(7bits)
+	b, err = buf.ReadByte()
+	if err != nil {
+		return
+	}
+	header = append(header, b)
+	mask := (b & 0x80) != 0
+	b &= 0x7f
+	lengthFields := 0
+	switch {
+	case b <= 125: // Payload length 7bits.
+		hybiFrame.header.Length = int64(b)
+	case b == 126: // Payload length 7+16bits
+		lengthFields = 2
+	case b == 127: // Payload length 7+64bits
+		lengthFields = 8
+	}
+	for i := 0; i < lengthFields; i++ {
+		b, err = buf.ReadByte()
+		if err != nil {
+			return
+		}
+		if lengthFields == 8 && i == 0 { // MSB must be zero when 7+64 bits
+			b &= 0x7f
+		}
+		header = append(header, b)
+		hybiFrame.header.Length = hybiFrame.header.Length*256 + int64(b)
+	}
+	if mask {
+		// Masking key. 4 bytes.
+		for i := 0; i < 4; i++ {
+			b, err = buf.ReadByte()
+			if err != nil {
+				return
+			}
+			header = append(header, b)
+			hybiFrame.header.MaskingKey = append(hybiFrame.header.MaskingKey, b)
+		}
+	}
+	hybiFrame.reader = io.LimitReader(buf.Reader, hybiFrame.header.Length)
+	hybiFrame.header.data = bytes.NewBuffer(header)
+	hybiFrame.length = len(header) + int(hybiFrame.header.Length)
+	return
+}
+
+// A HybiFrameWriter is a writer for hybi frame.
+type hybiFrameWriter struct {
+	writer *bufio.Writer
+
+	header *hybiFrameHeader
+}
+
+func (frame *hybiFrameWriter) Write(msg []byte) (n int, err error) {
+	var header []byte
+	var b byte
+	if frame.header.Fin {
+		b |= 0x80
+	}
+	for i := 0; i < 3; i++ {
+		if frame.header.Rsv[i] {
+			j := uint(6 - i)
+			b |= 1 << j
+		}
+	}
+	b |= frame.header.OpCode
+	header = append(header, b)
+	if frame.header.MaskingKey != nil {
+		b = 0x80
+	} else {
+		b = 0
+	}
+	lengthFields := 0
+	length := len(msg)
+	switch {
+	case length <= 125:
+		b |= byte(length)
+	case length < 65536:
+		b |= 126
+		lengthFields = 2
+	default:
+		b |= 127
+		lengthFields = 8
+	}
+	header = append(header, b)
+	for i := 0; i < lengthFields; i++ {
+		j := uint((lengthFields - i - 1) * 8)
+		b = byte((length >> j) & 0xff)
+		header = append(header, b)
+	}
+	if frame.header.MaskingKey != nil {
+		if len(frame.header.MaskingKey) != 4 {
+			return 0, ErrBadMaskingKey
+		}
+		header = append(header, frame.header.MaskingKey...)
+		frame.writer.Write(header)
+		data := make([]byte, length)
+		for i := range data {
+			data[i] = msg[i] ^ frame.header.MaskingKey[i%4]
+		}
+		frame.writer.Write(data)
+		err = frame.writer.Flush()
+		return length, err
+	}
+	frame.writer.Write(header)
+	frame.writer.Write(msg)
+	err = frame.writer.Flush()
+	return length, err
+}
+
+func (frame *hybiFrameWriter) Close() error { return nil }
+
+type hybiFrameWriterFactory struct {
+	*bufio.Writer
+	needMaskingKey bool
+}
+
+func (buf hybiFrameWriterFactory) NewFrameWriter(payloadType byte) (frame frameWriter, err error) {
+	frameHeader := &hybiFrameHeader{Fin: true, OpCode: payloadType}
+	if buf.needMaskingKey {
+		frameHeader.MaskingKey, err = generateMaskingKey()
+		if err != nil {
+			return nil, err
+		}
+	}
+	return &hybiFrameWriter{writer: buf.Writer, header: frameHeader}, nil
+}
+
+type hybiFrameHandler struct {
+	conn        *Conn
+	payloadType byte
+}
+
+func (handler *hybiFrameHandler) HandleFrame(frame frameReader) (frameReader, error) {
+	if handler.conn.IsServerConn() {
+		// The client MUST mask all frames sent to the server.
+		if frame.(*hybiFrameReader).header.MaskingKey == nil {
+			handler.WriteClose(closeStatusProtocolError)
+			return nil, io.EOF
+		}
+	} else {
+		// The server MUST NOT mask all frames.
+		if frame.(*hybiFrameReader).header.MaskingKey != nil {
+			handler.WriteClose(closeStatusProtocolError)
+			return nil, io.EOF
+		}
+	}
+	if header := frame.HeaderReader(); header != nil {
+		io.Copy(ioutil.Discard, header)
+	}
+	switch frame.PayloadType() {
+	case ContinuationFrame:
+		frame.(*hybiFrameReader).header.OpCode = handler.payloadType
+	case TextFrame, BinaryFrame:
+		handler.payloadType = frame.PayloadType()
+	case CloseFrame:
+		return nil, io.EOF
+	case PingFrame, PongFrame:
+		b := make([]byte, maxControlFramePayloadLength)
+		n, err := io.ReadFull(frame, b)
+		if err != nil && err != io.EOF && err != io.ErrUnexpectedEOF {
+			return nil, err
+		}
+		io.Copy(ioutil.Discard, frame)
+		if frame.PayloadType() == PingFrame {
+			if _, err := handler.WritePong(b[:n]); err != nil {
+				return nil, err
+			}
+		}
+		return nil, nil
+	}
+	return frame, nil
+}
+
+func (handler *hybiFrameHandler) WriteClose(status int) (err error) {
+	handler.conn.wio.Lock()
+	defer handler.conn.wio.Unlock()
+	w, err := handler.conn.frameWriterFactory.NewFrameWriter(CloseFrame)
+	if err != nil {
+		return err
+	}
+	msg := make([]byte, 2)
+	binary.BigEndian.PutUint16(msg, uint16(status))
+	_, err = w.Write(msg)
+	w.Close()
+	return err
+}
+
+func (handler *hybiFrameHandler) WritePong(msg []byte) (n int, err error) {
+	handler.conn.wio.Lock()
+	defer handler.conn.wio.Unlock()
+	w, err := handler.conn.frameWriterFactory.NewFrameWriter(PongFrame)
+	if err != nil {
+		return 0, err
+	}
+	n, err = w.Write(msg)
+	w.Close()
+	return n, err
+}
+
+// newHybiConn creates a new WebSocket connection speaking hybi draft protocol.
+func newHybiConn(config *Config, buf *bufio.ReadWriter, rwc io.ReadWriteCloser, request *http.Request) *Conn {
+	if buf == nil {
+		br := bufio.NewReader(rwc)
+		bw := bufio.NewWriter(rwc)
+		buf = bufio.NewReadWriter(br, bw)
+	}
+	ws := &Conn{config: config, request: request, buf: buf, rwc: rwc,
+		frameReaderFactory: hybiFrameReaderFactory{buf.Reader},
+		frameWriterFactory: hybiFrameWriterFactory{
+			buf.Writer, request == nil},
+		PayloadType:        TextFrame,
+		defaultCloseStatus: closeStatusNormal}
+	ws.frameHandler = &hybiFrameHandler{conn: ws}
+	return ws
+}
+
+// generateMaskingKey generates a masking key for a frame.
+func generateMaskingKey() (maskingKey []byte, err error) {
+	maskingKey = make([]byte, 4)
+	if _, err = io.ReadFull(rand.Reader, maskingKey); err != nil {
+		return
+	}
+	return
+}
+
+// generateNonce generates a nonce consisting of a randomly selected 16-byte
+// value that has been base64-encoded.
+func generateNonce() (nonce []byte) {
+	key := make([]byte, 16)
+	if _, err := io.ReadFull(rand.Reader, key); err != nil {
+		panic(err)
+	}
+	nonce = make([]byte, 24)
+	base64.StdEncoding.Encode(nonce, key)
+	return
+}
+
+// removeZone removes IPv6 zone identifer from host.
+// E.g., "[fe80::1%en0]:8080" to "[fe80::1]:8080"
+func removeZone(host string) string {
+	if !strings.HasPrefix(host, "[") {
+		return host
+	}
+	i := strings.LastIndex(host, "]")
+	if i < 0 {
+		return host
+	}
+	j := strings.LastIndex(host[:i], "%")
+	if j < 0 {
+		return host
+	}
+	return host[:j] + host[i:]
+}
+
+// getNonceAccept computes the base64-encoded SHA-1 of the concatenation of
+// the nonce ("Sec-WebSocket-Key" value) with the websocket GUID string.
+func getNonceAccept(nonce []byte) (expected []byte, err error) {
+	h := sha1.New()
+	if _, err = h.Write(nonce); err != nil {
+		return
+	}
+	if _, err = h.Write([]byte(websocketGUID)); err != nil {
+		return
+	}
+	expected = make([]byte, 28)
+	base64.StdEncoding.Encode(expected, h.Sum(nil))
+	return
+}
+
+// Client handshake described in draft-ietf-hybi-thewebsocket-protocol-17
+func hybiClientHandshake(config *Config, br *bufio.Reader, bw *bufio.Writer) (err error) {
+	bw.WriteString("GET " + config.Location.RequestURI() + " HTTP/1.1\r\n")
+
+	// According to RFC 6874, an HTTP client, proxy, or other
+	// intermediary must remove any IPv6 zone identifier attached
+	// to an outgoing URI.
+	bw.WriteString("Host: " + removeZone(config.Location.Host) + "\r\n")
+	bw.WriteString("Upgrade: websocket\r\n")
+	bw.WriteString("Connection: Upgrade\r\n")
+	nonce := generateNonce()
+	if config.handshakeData != nil {
+		nonce = []byte(config.handshakeData["key"])
+	}
+	bw.WriteString("Sec-WebSocket-Key: " + string(nonce) + "\r\n")
+	bw.WriteString("Origin: " + strings.ToLower(config.Origin.String()) + "\r\n")
+
+	if config.Version != ProtocolVersionHybi13 {
+		return ErrBadProtocolVersion
+	}
+
+	bw.WriteString("Sec-WebSocket-Version: " + fmt.Sprintf("%d", config.Version) + "\r\n")
+	if len(config.Protocol) > 0 {
+		bw.WriteString("Sec-WebSocket-Protocol: " + strings.Join(config.Protocol, ", ") + "\r\n")
+	}
+	// TODO(ukai): send Sec-WebSocket-Extensions.
+	err = config.Header.WriteSubset(bw, handshakeHeader)
+	if err != nil {
+		return err
+	}
+
+	bw.WriteString("\r\n")
+	if err = bw.Flush(); err != nil {
+		return err
+	}
+
+	resp, err := http.ReadResponse(br, &http.Request{Method: "GET"})
+	if err != nil {
+		return err
+	}
+	if resp.StatusCode != 101 {
+		return ErrBadStatus
+	}
+	if strings.ToLower(resp.Header.Get("Upgrade")) != "websocket" ||
+		strings.ToLower(resp.Header.Get("Connection")) != "upgrade" {
+		return ErrBadUpgrade
+	}
+	expectedAccept, err := getNonceAccept(nonce)
+	if err != nil {
+		return err
+	}
+	if resp.Header.Get("Sec-WebSocket-Accept") != string(expectedAccept) {
+		return ErrChallengeResponse
+	}
+	if resp.Header.Get("Sec-WebSocket-Extensions") != "" {
+		return ErrUnsupportedExtensions
+	}
+	offeredProtocol := resp.Header.Get("Sec-WebSocket-Protocol")
+	if offeredProtocol != "" {
+		protocolMatched := false
+		for i := 0; i < len(config.Protocol); i++ {
+			if config.Protocol[i] == offeredProtocol {
+				protocolMatched = true
+				break
+			}
+		}
+		if !protocolMatched {
+			return ErrBadWebSocketProtocol
+		}
+		config.Protocol = []string{offeredProtocol}
+	}
+
+	return nil
+}
+
+// newHybiClientConn creates a client WebSocket connection after handshake.
+func newHybiClientConn(config *Config, buf *bufio.ReadWriter, rwc io.ReadWriteCloser) *Conn {
+	return newHybiConn(config, buf, rwc, nil)
+}
+
+// A HybiServerHandshaker performs a server handshake using hybi draft protocol.
+type hybiServerHandshaker struct {
+	*Config
+	accept []byte
+}
+
+func (c *hybiServerHandshaker) ReadHandshake(buf *bufio.Reader, req *http.Request) (code int, err error) {
+	c.Version = ProtocolVersionHybi13
+	if req.Method != "GET" {
+		return http.StatusMethodNotAllowed, ErrBadRequestMethod
+	}
+	// HTTP version can be safely ignored.
+
+	if strings.ToLower(req.Header.Get("Upgrade")) != "websocket" ||
+		!strings.Contains(strings.ToLower(req.Header.Get("Connection")), "upgrade") {
+		return http.StatusBadRequest, ErrNotWebSocket
+	}
+
+	key := req.Header.Get("Sec-Websocket-Key")
+	if key == "" {
+		return http.StatusBadRequest, ErrChallengeResponse
+	}
+	version := req.Header.Get("Sec-Websocket-Version")
+	switch version {
+	case "13":
+		c.Version = ProtocolVersionHybi13
+	default:
+		return http.StatusBadRequest, ErrBadWebSocketVersion
+	}
+	var scheme string
+	if req.TLS != nil {
+		scheme = "wss"
+	} else {
+		scheme = "ws"
+	}
+	c.Location, err = url.ParseRequestURI(scheme + "://" + req.Host + req.URL.RequestURI())
+	if err != nil {
+		return http.StatusBadRequest, err
+	}
+	protocol := strings.TrimSpace(req.Header.Get("Sec-Websocket-Protocol"))
+	if protocol != "" {
+		protocols := strings.Split(protocol, ",")
+		for i := 0; i < len(protocols); i++ {
+			c.Protocol = append(c.Protocol, strings.TrimSpace(protocols[i]))
+		}
+	}
+	c.accept, err = getNonceAccept([]byte(key))
+	if err != nil {
+		return http.StatusInternalServerError, err
+	}
+	return http.StatusSwitchingProtocols, nil
+}
+
+// Origin parses the Origin header in req.
+// If the Origin header is not set, it returns nil and nil.
+func Origin(config *Config, req *http.Request) (*url.URL, error) {
+	var origin string
+	switch config.Version {
+	case ProtocolVersionHybi13:
+		origin = req.Header.Get("Origin")
+	}
+	if origin == "" {
+		return nil, nil
+	}
+	return url.ParseRequestURI(origin)
+}
+
+func (c *hybiServerHandshaker) AcceptHandshake(buf *bufio.Writer) (err error) {
+	if len(c.Protocol) > 0 {
+		if len(c.Protocol) != 1 {
+			// You need choose a Protocol in Handshake func in Server.
+			return ErrBadWebSocketProtocol
+		}
+	}
+	buf.WriteString("HTTP/1.1 101 Switching Protocols\r\n")
+	buf.WriteString("Upgrade: websocket\r\n")
+	buf.WriteString("Connection: Upgrade\r\n")
+	buf.WriteString("Sec-WebSocket-Accept: " + string(c.accept) + "\r\n")
+	if len(c.Protocol) > 0 {
+		buf.WriteString("Sec-WebSocket-Protocol: " + c.Protocol[0] + "\r\n")
+	}
+	// TODO(ukai): send Sec-WebSocket-Extensions.
+	if c.Header != nil {
+		err := c.Header.WriteSubset(buf, handshakeHeader)
+		if err != nil {
+			return err
+		}
+	}
+	buf.WriteString("\r\n")
+	return buf.Flush()
+}
+
+func (c *hybiServerHandshaker) NewServerConn(buf *bufio.ReadWriter, rwc io.ReadWriteCloser, request *http.Request) *Conn {
+	return newHybiServerConn(c.Config, buf, rwc, request)
+}
+
+// newHybiServerConn returns a new WebSocket connection speaking hybi draft protocol.
+func newHybiServerConn(config *Config, buf *bufio.ReadWriter, rwc io.ReadWriteCloser, request *http.Request) *Conn {
+	return newHybiConn(config, buf, rwc, request)
+}
--- a/vendor/golang.org/x/net/websocket/server.go
+++ b/vendor/golang.org/x/net/websocket/server.go
@@ -0,0 +1,113 @@
+// Copyright 2009 The Go 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"
+	"fmt"
+	"io"
+	"net/http"
+)
+
+func newServerConn(rwc io.ReadWriteCloser, buf *bufio.ReadWriter, req *http.Request, config *Config, handshake func(*Config, *http.Request) error) (conn *Conn, err error) {
+	var hs serverHandshaker = &hybiServerHandshaker{Config: config}
+	code, err := hs.ReadHandshake(buf.Reader, req)
+	if err == ErrBadWebSocketVersion {
+		fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
+		fmt.Fprintf(buf, "Sec-WebSocket-Version: %s\r\n", SupportedProtocolVersion)
+		buf.WriteString("\r\n")
+		buf.WriteString(err.Error())
+		buf.Flush()
+		return
+	}
+	if err != nil {
+		fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
+		buf.WriteString("\r\n")
+		buf.WriteString(err.Error())
+		buf.Flush()
+		return
+	}
+	if handshake != nil {
+		err = handshake(config, req)
+		if err != nil {
+			code = http.StatusForbidden
+			fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
+			buf.WriteString("\r\n")
+			buf.Flush()
+			return
+		}
+	}
+	err = hs.AcceptHandshake(buf.Writer)
+	if err != nil {
+		code = http.StatusBadRequest
+		fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
+		buf.WriteString("\r\n")
+		buf.Flush()
+		return
+	}
+	conn = hs.NewServerConn(buf, rwc, req)
+	return
+}
+
+// Server represents a server of a WebSocket.
+type Server struct {
+	// Config is a WebSocket configuration for new WebSocket connection.
+	Config
+
+	// Handshake is an optional function in WebSocket handshake.
+	// For example, you can check, or don't check Origin header.
+	// Another example, you can select config.Protocol.
+	Handshake func(*Config, *http.Request) error
+
+	// Handler handles a WebSocket connection.
+	Handler
+}
+
+// ServeHTTP implements the http.Handler interface for a WebSocket
+func (s Server) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	s.serveWebSocket(w, req)
+}
+
+func (s Server) serveWebSocket(w http.ResponseWriter, req *http.Request) {
+	rwc, buf, err := w.(http.Hijacker).Hijack()
+	if err != nil {
+		panic("Hijack failed: " + err.Error())
+	}
+	// The server should abort the WebSocket connection if it finds
+	// the client did not send a handshake that matches with protocol
+	// specification.
+	defer rwc.Close()
+	conn, err := newServerConn(rwc, buf, req, &s.Config, s.Handshake)
+	if err != nil {
+		return
+	}
+	if conn == nil {
+		panic("unexpected nil conn")
+	}
+	s.Handler(conn)
+}
+
+// Handler is a simple interface to a WebSocket browser client.
+// It checks if Origin header is valid URL by default.
+// You might want to verify websocket.Conn.Config().Origin in the func.
+// If you use Server instead of Handler, you could call websocket.Origin and
+// check the origin in your Handshake func. So, if you want to accept
+// non-browser clients, which do not send an Origin header, set a
+// Server.Handshake that does not check the origin.
+type Handler func(*Conn)
+
+func checkOrigin(config *Config, req *http.Request) (err error) {
+	config.Origin, err = Origin(config, req)
+	if err == nil && config.Origin == nil {
+		return fmt.Errorf("null origin")
+	}
+	return err
+}
+
+// ServeHTTP implements the http.Handler interface for a WebSocket
+func (h Handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	s := Server{Handler: h, Handshake: checkOrigin}
+	s.serveWebSocket(w, req)
+}
--- a/vendor/golang.org/x/net/websocket/websocket.go
+++ b/vendor/golang.org/x/net/websocket/websocket.go
@@ -0,0 +1,451 @@
+// Copyright 2009 The Go 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 implements a client and server for the WebSocket protocol
+// as specified in RFC 6455.
+//
+// This package currently lacks some features found in alternative
+// and more actively maintained WebSocket packages:
+//
+//     https://godoc.org/github.com/gorilla/websocket
+//     https://godoc.org/nhooyr.io/websocket
+package websocket // import "golang.org/x/net/websocket"
+
+import (
+	"bufio"
+	"crypto/tls"
+	"encoding/json"
+	"errors"
+	"io"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/url"
+	"sync"
+	"time"
+)
+
+const (
+	ProtocolVersionHybi13    = 13
+	ProtocolVersionHybi      = ProtocolVersionHybi13
+	SupportedProtocolVersion = "13"
+
+	ContinuationFrame = 0
+	TextFrame         = 1
+	BinaryFrame       = 2
+	CloseFrame        = 8
+	PingFrame         = 9
+	PongFrame         = 10
+	UnknownFrame      = 255
+
+	DefaultMaxPayloadBytes = 32 << 20 // 32MB
+)
+
+// ProtocolError represents WebSocket protocol errors.
+type ProtocolError struct {
+	ErrorString string
+}
+
+func (err *ProtocolError) Error() string { return err.ErrorString }
+
+var (
+	ErrBadProtocolVersion   = &ProtocolError{"bad protocol version"}
+	ErrBadScheme            = &ProtocolError{"bad scheme"}
+	ErrBadStatus            = &ProtocolError{"bad status"}
+	ErrBadUpgrade           = &ProtocolError{"missing or bad upgrade"}
+	ErrBadWebSocketOrigin   = &ProtocolError{"missing or bad WebSocket-Origin"}
+	ErrBadWebSocketLocation = &ProtocolError{"missing or bad WebSocket-Location"}
+	ErrBadWebSocketProtocol = &ProtocolError{"missing or bad WebSocket-Protocol"}
+	ErrBadWebSocketVersion  = &ProtocolError{"missing or bad WebSocket Version"}
+	ErrChallengeResponse    = &ProtocolError{"mismatch challenge/response"}
+	ErrBadFrame             = &ProtocolError{"bad frame"}
+	ErrBadFrameBoundary     = &ProtocolError{"not on frame boundary"}
+	ErrNotWebSocket         = &ProtocolError{"not websocket protocol"}
+	ErrBadRequestMethod     = &ProtocolError{"bad method"}
+	ErrNotSupported         = &ProtocolError{"not supported"}
+)
+
+// ErrFrameTooLarge is returned by Codec's Receive method if payload size
+// exceeds limit set by Conn.MaxPayloadBytes
+var ErrFrameTooLarge = errors.New("websocket: frame payload size exceeds limit")
+
+// Addr is an implementation of net.Addr for WebSocket.
+type Addr struct {
+	*url.URL
+}
+
+// Network returns the network type for a WebSocket, "websocket".
+func (addr *Addr) Network() string { return "websocket" }
+
+// Config is a WebSocket configuration
+type Config struct {
+	// A WebSocket server address.
+	Location *url.URL
+
+	// A Websocket client origin.
+	Origin *url.URL
+
+	// WebSocket subprotocols.
+	Protocol []string
+
+	// WebSocket protocol version.
+	Version int
+
+	// TLS config for secure WebSocket (wss).
+	TlsConfig *tls.Config
+
+	// Additional header fields to be sent in WebSocket opening handshake.
+	Header http.Header
+
+	// Dialer used when opening websocket connections.
+	Dialer *net.Dialer
+
+	handshakeData map[string]string
+}
+
+// serverHandshaker is an interface to handle WebSocket server side handshake.
+type serverHandshaker interface {
+	// ReadHandshake reads handshake request message from client.
+	// Returns http response code and error if any.
+	ReadHandshake(buf *bufio.Reader, req *http.Request) (code int, err error)
+
+	// AcceptHandshake accepts the client handshake request and sends
+	// handshake response back to client.
+	AcceptHandshake(buf *bufio.Writer) (err error)
+
+	// NewServerConn creates a new WebSocket connection.
+	NewServerConn(buf *bufio.ReadWriter, rwc io.ReadWriteCloser, request *http.Request) (conn *Conn)
+}
+
+// frameReader is an interface to read a WebSocket frame.
+type frameReader interface {
+	// Reader is to read payload of the frame.
+	io.Reader
+
+	// PayloadType returns payload type.
+	PayloadType() byte
+
+	// HeaderReader returns a reader to read header of the frame.
+	HeaderReader() io.Reader
+
+	// TrailerReader returns a reader to read trailer of the frame.
+	// If it returns nil, there is no trailer in the frame.
+	TrailerReader() io.Reader
+
+	// Len returns total length of the frame, including header and trailer.
+	Len() int
+}
+
+// frameReaderFactory is an interface to creates new frame reader.
+type frameReaderFactory interface {
+	NewFrameReader() (r frameReader, err error)
+}
+
+// frameWriter is an interface to write a WebSocket frame.
+type frameWriter interface {
+	// Writer is to write payload of the frame.
+	io.WriteCloser
+}
+
+// frameWriterFactory is an interface to create new frame writer.
+type frameWriterFactory interface {
+	NewFrameWriter(payloadType byte) (w frameWriter, err error)
+}
+
+type frameHandler interface {
+	HandleFrame(frame frameReader) (r frameReader, err error)
+	WriteClose(status int) (err error)
+}
+
+// Conn represents a WebSocket connection.
+//
+// Multiple goroutines may invoke methods on a Conn simultaneously.
+type Conn struct {
+	config  *Config
+	request *http.Request
+
+	buf *bufio.ReadWriter
+	rwc io.ReadWriteCloser
+
+	rio sync.Mutex
+	frameReaderFactory
+	frameReader
+
+	wio sync.Mutex
+	frameWriterFactory
+
+	frameHandler
+	PayloadType        byte
+	defaultCloseStatus int
+
+	// MaxPayloadBytes limits the size of frame payload received over Conn
+	// by Codec's Receive method. If zero, DefaultMaxPayloadBytes is used.
+	MaxPayloadBytes int
+}
+
+// Read implements the io.Reader interface:
+// it reads data of a frame from the WebSocket connection.
+// if msg is not large enough for the frame data, it fills the msg and next Read
+// will read the rest of the frame data.
+// it reads Text frame or Binary frame.
+func (ws *Conn) Read(msg []byte) (n int, err error) {
+	ws.rio.Lock()
+	defer ws.rio.Unlock()
+again:
+	if ws.frameReader == nil {
+		frame, err := ws.frameReaderFactory.NewFrameReader()
+		if err != nil {
+			return 0, err
+		}
+		ws.frameReader, err = ws.frameHandler.HandleFrame(frame)
+		if err != nil {
+			return 0, err
+		}
+		if ws.frameReader == nil {
+			goto again
+		}
+	}
+	n, err = ws.frameReader.Read(msg)
+	if err == io.EOF {
+		if trailer := ws.frameReader.TrailerReader(); trailer != nil {
+			io.Copy(ioutil.Discard, trailer)
+		}
+		ws.frameReader = nil
+		goto again
+	}
+	return n, err
+}
+
+// Write implements the io.Writer interface:
+// it writes data as a frame to the WebSocket connection.
+func (ws *Conn) Write(msg []byte) (n int, err error) {
+	ws.wio.Lock()
+	defer ws.wio.Unlock()
+	w, err := ws.frameWriterFactory.NewFrameWriter(ws.PayloadType)
+	if err != nil {
+		return 0, err
+	}
+	n, err = w.Write(msg)
+	w.Close()
+	return n, err
+}
+
+// Close implements the io.Closer interface.
+func (ws *Conn) Close() error {
+	err := ws.frameHandler.WriteClose(ws.defaultCloseStatus)
+	err1 := ws.rwc.Close()
+	if err != nil {
+		return err
+	}
+	return err1
+}
+
+// IsClientConn reports whether ws is a client-side connection.
+func (ws *Conn) IsClientConn() bool { return ws.request == nil }
+
+// IsServerConn reports whether ws is a server-side connection.
+func (ws *Conn) IsServerConn() bool { return ws.request != nil }
+
+// LocalAddr returns the WebSocket Origin for the connection for client, or
+// the WebSocket location for server.
+func (ws *Conn) LocalAddr() net.Addr {
+	if ws.IsClientConn() {
+		return &Addr{ws.config.Origin}
+	}
+	return &Addr{ws.config.Location}
+}
+
+// RemoteAddr returns the WebSocket location for the connection for client, or
+// the Websocket Origin for server.
+func (ws *Conn) RemoteAddr() net.Addr {
+	if ws.IsClientConn() {
+		return &Addr{ws.config.Location}
+	}
+	return &Addr{ws.config.Origin}
+}
+
+var errSetDeadline = errors.New("websocket: cannot set deadline: not using a net.Conn")
+
+// SetDeadline sets the connection's network read & write deadlines.
+func (ws *Conn) SetDeadline(t time.Time) error {
+	if conn, ok := ws.rwc.(net.Conn); ok {
+		return conn.SetDeadline(t)
+	}
+	return errSetDeadline
+}
+
+// SetReadDeadline sets the connection's network read deadline.
+func (ws *Conn) SetReadDeadline(t time.Time) error {
+	if conn, ok := ws.rwc.(net.Conn); ok {
+		return conn.SetReadDeadline(t)
+	}
+	return errSetDeadline
+}
+
+// SetWriteDeadline sets the connection's network write deadline.
+func (ws *Conn) SetWriteDeadline(t time.Time) error {
+	if conn, ok := ws.rwc.(net.Conn); ok {
+		return conn.SetWriteDeadline(t)
+	}
+	return errSetDeadline
+}
+
+// Config returns the WebSocket config.
+func (ws *Conn) Config() *Config { return ws.config }
+
+// Request returns the http request upgraded to the WebSocket.
+// It is nil for client side.
+func (ws *Conn) Request() *http.Request { return ws.request }
+
+// Codec represents a symmetric pair of functions that implement a codec.
+type Codec struct {
+	Marshal   func(v interface{}) (data []byte, payloadType byte, err error)
+	Unmarshal func(data []byte, payloadType byte, v interface{}) (err error)
+}
+
+// Send sends v marshaled by cd.Marshal as single frame to ws.
+func (cd Codec) Send(ws *Conn, v interface{}) (err error) {
+	data, payloadType, err := cd.Marshal(v)
+	if err != nil {
+		return err
+	}
+	ws.wio.Lock()
+	defer ws.wio.Unlock()
+	w, err := ws.frameWriterFactory.NewFrameWriter(payloadType)
+	if err != nil {
+		return err
+	}
+	_, err = w.Write(data)
+	w.Close()
+	return err
+}
+
+// Receive receives single frame from ws, unmarshaled by cd.Unmarshal and stores
+// in v. The whole frame payload is read to an in-memory buffer; max size of
+// payload is defined by ws.MaxPayloadBytes. If frame payload size exceeds
+// limit, ErrFrameTooLarge is returned; in this case frame is not read off wire
+// completely. The next call to Receive would read and discard leftover data of
+// previous oversized frame before processing next frame.
+func (cd Codec) Receive(ws *Conn, v interface{}) (err error) {
+	ws.rio.Lock()
+	defer ws.rio.Unlock()
+	if ws.frameReader != nil {
+		_, err = io.Copy(ioutil.Discard, ws.frameReader)
+		if err != nil {
+			return err
+		}
+		ws.frameReader = nil
+	}
+again:
+	frame, err := ws.frameReaderFactory.NewFrameReader()
+	if err != nil {
+		return err
+	}
+	frame, err = ws.frameHandler.HandleFrame(frame)
+	if err != nil {
+		return err
+	}
+	if frame == nil {
+		goto again
+	}
+	maxPayloadBytes := ws.MaxPayloadBytes
+	if maxPayloadBytes == 0 {
+		maxPayloadBytes = DefaultMaxPayloadBytes
+	}
+	if hf, ok := frame.(*hybiFrameReader); ok && hf.header.Length > int64(maxPayloadBytes) {
+		// payload size exceeds limit, no need to call Unmarshal
+		//
+		// set frameReader to current oversized frame so that
+		// the next call to this function can drain leftover
+		// data before processing the next frame
+		ws.frameReader = frame
+		return ErrFrameTooLarge
+	}
+	payloadType := frame.PayloadType()
+	data, err := ioutil.ReadAll(frame)
+	if err != nil {
+		return err
+	}
+	return cd.Unmarshal(data, payloadType, v)
+}
+
+func marshal(v interface{}) (msg []byte, payloadType byte, err error) {
+	switch data := v.(type) {
+	case string:
+		return []byte(data), TextFrame, nil
+	case []byte:
+		return data, BinaryFrame, nil
+	}
+	return nil, UnknownFrame, ErrNotSupported
+}
+
+func unmarshal(msg []byte, payloadType byte, v interface{}) (err error) {
+	switch data := v.(type) {
+	case *string:
+		*data = string(msg)
+		return nil
+	case *[]byte:
+		*data = msg
+		return nil
+	}
+	return ErrNotSupported
+}
+
+/*
+Message is a codec to send/receive text/binary data in a frame on WebSocket connection.
+To send/receive text frame, use string type.
+To send/receive binary frame, use []byte type.
+
+Trivial usage:
+
+	import "websocket"
+
+	// receive text frame
+	var message string
+	websocket.Message.Receive(ws, &message)
+
+	// send text frame
+	message = "hello"
+	websocket.Message.Send(ws, message)
+
+	// receive binary frame
+	var data []byte
+	websocket.Message.Receive(ws, &data)
+
+	// send binary frame
+	data = []byte{0, 1, 2}
+	websocket.Message.Send(ws, data)
+
+*/
+var Message = Codec{marshal, unmarshal}
+
+func jsonMarshal(v interface{}) (msg []byte, payloadType byte, err error) {
+	msg, err = json.Marshal(v)
+	return msg, TextFrame, err
+}
+
+func jsonUnmarshal(msg []byte, payloadType byte, v interface{}) (err error) {
+	return json.Unmarshal(msg, v)
+}
+
+/*
+JSON is a codec to send/receive JSON data in a frame from a WebSocket connection.
+
+Trivial usage:
+
+	import "websocket"
+
+	type T struct {
+		Msg string
+		Count int
+	}
+
+	// receive JSON type T
+	var data T
+	websocket.JSON.Receive(ws, &data)
+
+	// send JSON type T
+	websocket.JSON.Send(ws, data)
+*/
+var JSON = Codec{jsonMarshal, jsonUnmarshal}