--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/vendor/github.com/gorilla/websocket/server.go Sat Sep 29 18:09:54 2018 +0200
@@ -0,0 +1,363 @@
+// 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"
+ "errors"
+ "io"
+ "net/http"
+ "net/url"
+ "strings"
+ "time"
+)
+
+// HandshakeError describes an error with the handshake from the peer.
+type HandshakeError struct {
+ message string
+}
+
+func (e HandshakeError) Error() string { return e.message }
+
+// Upgrader specifies parameters for upgrading an HTTP connection to a
+// WebSocket connection.
+type Upgrader struct {
+ // HandshakeTimeout specifies the duration for the handshake to complete.
+ HandshakeTimeout time.Duration
+
+ // ReadBufferSize and WriteBufferSize specify I/O buffer sizes. If a buffer
+ // size is zero, then buffers allocated by the HTTP server are used. The
+ // I/O buffer sizes do not limit the size of the messages that can be sent
+ // or received.
+ ReadBufferSize, WriteBufferSize int
+
+ // WriteBufferPool is a pool of buffers for write operations. If the value
+ // is not set, then write buffers are allocated to the connection for the
+ // lifetime of the connection.
+ //
+ // A pool is most useful when the application has a modest volume of writes
+ // across a large number of connections.
+ //
+ // Applications should use a single pool for each unique value of
+ // WriteBufferSize.
+ WriteBufferPool BufferPool
+
+ // Subprotocols specifies the server's supported protocols in order of
+ // preference. If this field is not nil, then the Upgrade method negotiates a
+ // subprotocol by selecting the first match in this list with a protocol
+ // requested by the client. If there's no match, then no protocol is
+ // negotiated (the Sec-Websocket-Protocol header is not included in the
+ // handshake response).
+ Subprotocols []string
+
+ // Error specifies the function for generating HTTP error responses. If Error
+ // is nil, then http.Error is used to generate the HTTP response.
+ Error func(w http.ResponseWriter, r *http.Request, status int, reason error)
+
+ // CheckOrigin returns true if the request Origin header is acceptable. If
+ // CheckOrigin is nil, then a safe default is used: return false if the
+ // Origin request header is present and the origin host is not equal to
+ // request Host header.
+ //
+ // A CheckOrigin function should carefully validate the request origin to
+ // prevent cross-site request forgery.
+ CheckOrigin func(r *http.Request) bool
+
+ // EnableCompression specify if the server 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
+}
+
+func (u *Upgrader) returnError(w http.ResponseWriter, r *http.Request, status int, reason string) (*Conn, error) {
+ err := HandshakeError{reason}
+ if u.Error != nil {
+ u.Error(w, r, status, err)
+ } else {
+ w.Header().Set("Sec-Websocket-Version", "13")
+ http.Error(w, http.StatusText(status), status)
+ }
+ return nil, err
+}
+
+// checkSameOrigin returns true if the origin is not set or is equal to the request host.
+func checkSameOrigin(r *http.Request) bool {
+ origin := r.Header["Origin"]
+ if len(origin) == 0 {
+ return true
+ }
+ u, err := url.Parse(origin[0])
+ if err != nil {
+ return false
+ }
+ return equalASCIIFold(u.Host, r.Host)
+}
+
+func (u *Upgrader) selectSubprotocol(r *http.Request, responseHeader http.Header) string {
+ if u.Subprotocols != nil {
+ clientProtocols := Subprotocols(r)
+ for _, serverProtocol := range u.Subprotocols {
+ for _, clientProtocol := range clientProtocols {
+ if clientProtocol == serverProtocol {
+ return clientProtocol
+ }
+ }
+ }
+ } else if responseHeader != nil {
+ return responseHeader.Get("Sec-Websocket-Protocol")
+ }
+ return ""
+}
+
+// Upgrade upgrades the HTTP server connection to the WebSocket protocol.
+//
+// The responseHeader is included in the response to the client's upgrade
+// request. Use the responseHeader to specify cookies (Set-Cookie) and the
+// application negotiated subprotocol (Sec-WebSocket-Protocol).
+//
+// If the upgrade fails, then Upgrade replies to the client with an HTTP error
+// response.
+func (u *Upgrader) Upgrade(w http.ResponseWriter, r *http.Request, responseHeader http.Header) (*Conn, error) {
+ const badHandshake = "websocket: the client is not using the websocket protocol: "
+
+ if !tokenListContainsValue(r.Header, "Connection", "upgrade") {
+ return u.returnError(w, r, http.StatusBadRequest, badHandshake+"'upgrade' token not found in 'Connection' header")
+ }
+
+ if !tokenListContainsValue(r.Header, "Upgrade", "websocket") {
+ return u.returnError(w, r, http.StatusBadRequest, badHandshake+"'websocket' token not found in 'Upgrade' header")
+ }
+
+ if r.Method != "GET" {
+ return u.returnError(w, r, http.StatusMethodNotAllowed, badHandshake+"request method is not GET")
+ }
+
+ if !tokenListContainsValue(r.Header, "Sec-Websocket-Version", "13") {
+ return u.returnError(w, r, http.StatusBadRequest, "websocket: unsupported version: 13 not found in 'Sec-Websocket-Version' header")
+ }
+
+ if _, ok := responseHeader["Sec-Websocket-Extensions"]; ok {
+ return u.returnError(w, r, http.StatusInternalServerError, "websocket: application specific 'Sec-WebSocket-Extensions' headers are unsupported")
+ }
+
+ checkOrigin := u.CheckOrigin
+ if checkOrigin == nil {
+ checkOrigin = checkSameOrigin
+ }
+ if !checkOrigin(r) {
+ return u.returnError(w, r, http.StatusForbidden, "websocket: request origin not allowed by Upgrader.CheckOrigin")
+ }
+
+ challengeKey := r.Header.Get("Sec-Websocket-Key")
+ if challengeKey == "" {
+ return u.returnError(w, r, http.StatusBadRequest, "websocket: not a websocket handshake: `Sec-WebSocket-Key' header is missing or blank")
+ }
+
+ subprotocol := u.selectSubprotocol(r, responseHeader)
+
+ // Negotiate PMCE
+ var compress bool
+ if u.EnableCompression {
+ for _, ext := range parseExtensions(r.Header) {
+ if ext[""] != "permessage-deflate" {
+ continue
+ }
+ compress = true
+ break
+ }
+ }
+
+ h, ok := w.(http.Hijacker)
+ if !ok {
+ return u.returnError(w, r, http.StatusInternalServerError, "websocket: response does not implement http.Hijacker")
+ }
+ var brw *bufio.ReadWriter
+ netConn, brw, err := h.Hijack()
+ if err != nil {
+ return u.returnError(w, r, http.StatusInternalServerError, err.Error())
+ }
+
+ if brw.Reader.Buffered() > 0 {
+ netConn.Close()
+ return nil, errors.New("websocket: client sent data before handshake is complete")
+ }
+
+ var br *bufio.Reader
+ if u.ReadBufferSize == 0 && bufioReaderSize(netConn, brw.Reader) > 256 {
+ // Reuse hijacked buffered reader as connection reader.
+ br = brw.Reader
+ }
+
+ buf := bufioWriterBuffer(netConn, brw.Writer)
+
+ var writeBuf []byte
+ if u.WriteBufferPool == nil && u.WriteBufferSize == 0 && len(buf) >= maxFrameHeaderSize+256 {
+ // Reuse hijacked write buffer as connection buffer.
+ writeBuf = buf
+ }
+
+ c := newConn(netConn, true, u.ReadBufferSize, u.WriteBufferSize, u.WriteBufferPool, br, writeBuf)
+ c.subprotocol = subprotocol
+
+ if compress {
+ c.newCompressionWriter = compressNoContextTakeover
+ c.newDecompressionReader = decompressNoContextTakeover
+ }
+
+ // Use larger of hijacked buffer and connection write buffer for header.
+ p := buf
+ if len(c.writeBuf) > len(p) {
+ p = c.writeBuf
+ }
+ p = p[:0]
+
+ p = append(p, "HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Accept: "...)
+ p = append(p, computeAcceptKey(challengeKey)...)
+ p = append(p, "\r\n"...)
+ if c.subprotocol != "" {
+ p = append(p, "Sec-WebSocket-Protocol: "...)
+ p = append(p, c.subprotocol...)
+ p = append(p, "\r\n"...)
+ }
+ if compress {
+ p = append(p, "Sec-WebSocket-Extensions: permessage-deflate; server_no_context_takeover; client_no_context_takeover\r\n"...)
+ }
+ for k, vs := range responseHeader {
+ if k == "Sec-Websocket-Protocol" {
+ continue
+ }
+ for _, v := range vs {
+ p = append(p, k...)
+ p = append(p, ": "...)
+ for i := 0; i < len(v); i++ {
+ b := v[i]
+ if b <= 31 {
+ // prevent response splitting.
+ b = ' '
+ }
+ p = append(p, b)
+ }
+ p = append(p, "\r\n"...)
+ }
+ }
+ p = append(p, "\r\n"...)
+
+ // Clear deadlines set by HTTP server.
+ netConn.SetDeadline(time.Time{})
+
+ if u.HandshakeTimeout > 0 {
+ netConn.SetWriteDeadline(time.Now().Add(u.HandshakeTimeout))
+ }
+ if _, err = netConn.Write(p); err != nil {
+ netConn.Close()
+ return nil, err
+ }
+ if u.HandshakeTimeout > 0 {
+ netConn.SetWriteDeadline(time.Time{})
+ }
+
+ return c, nil
+}
+
+// Upgrade upgrades the HTTP server connection to the WebSocket protocol.
+//
+// Deprecated: Use websocket.Upgrader instead.
+//
+// Upgrade does not perform origin checking. The application is responsible for
+// checking the Origin header before calling Upgrade. An example implementation
+// of the same origin policy check is:
+//
+// if req.Header.Get("Origin") != "http://"+req.Host {
+// http.Error(w, "Origin not allowed", http.StatusForbidden)
+// return
+// }
+//
+// If the endpoint supports subprotocols, then the application is responsible
+// for negotiating the protocol used on the connection. Use the Subprotocols()
+// function to get the subprotocols requested by the client. Use the
+// Sec-Websocket-Protocol response header to specify the subprotocol selected
+// by the application.
+//
+// The responseHeader is included in the response to the client's upgrade
+// request. Use the responseHeader to specify cookies (Set-Cookie) and the
+// negotiated subprotocol (Sec-Websocket-Protocol).
+//
+// The connection buffers IO to the underlying network connection. The
+// readBufSize and writeBufSize parameters specify the size of the buffers to
+// use. Messages can be larger than the buffers.
+//
+// If the request is not a valid WebSocket handshake, then Upgrade returns an
+// error of type HandshakeError. Applications should handle this error by
+// replying to the client with an HTTP error response.
+func Upgrade(w http.ResponseWriter, r *http.Request, responseHeader http.Header, readBufSize, writeBufSize int) (*Conn, error) {
+ u := Upgrader{ReadBufferSize: readBufSize, WriteBufferSize: writeBufSize}
+ u.Error = func(w http.ResponseWriter, r *http.Request, status int, reason error) {
+ // don't return errors to maintain backwards compatibility
+ }
+ u.CheckOrigin = func(r *http.Request) bool {
+ // allow all connections by default
+ return true
+ }
+ return u.Upgrade(w, r, responseHeader)
+}
+
+// Subprotocols returns the subprotocols requested by the client in the
+// Sec-Websocket-Protocol header.
+func Subprotocols(r *http.Request) []string {
+ h := strings.TrimSpace(r.Header.Get("Sec-Websocket-Protocol"))
+ if h == "" {
+ return nil
+ }
+ protocols := strings.Split(h, ",")
+ for i := range protocols {
+ protocols[i] = strings.TrimSpace(protocols[i])
+ }
+ return protocols
+}
+
+// IsWebSocketUpgrade returns true if the client requested upgrade to the
+// WebSocket protocol.
+func IsWebSocketUpgrade(r *http.Request) bool {
+ return tokenListContainsValue(r.Header, "Connection", "upgrade") &&
+ tokenListContainsValue(r.Header, "Upgrade", "websocket")
+}
+
+// bufioReaderSize size returns the size of a bufio.Reader.
+func bufioReaderSize(originalReader io.Reader, br *bufio.Reader) int {
+ // This code assumes that peek on a reset reader returns
+ // bufio.Reader.buf[:0].
+ // TODO: Use bufio.Reader.Size() after Go 1.10
+ br.Reset(originalReader)
+ if p, err := br.Peek(0); err == nil {
+ return cap(p)
+ }
+ return 0
+}
+
+// writeHook is an io.Writer that records the last slice passed to it vio
+// io.Writer.Write.
+type writeHook struct {
+ p []byte
+}
+
+func (wh *writeHook) Write(p []byte) (int, error) {
+ wh.p = p
+ return len(p), nil
+}
+
+// bufioWriterBuffer grabs the buffer from a bufio.Writer.
+func bufioWriterBuffer(originalWriter io.Writer, bw *bufio.Writer) []byte {
+ // This code assumes that bufio.Writer.buf[:1] is passed to the
+ // bufio.Writer's underlying writer.
+ var wh writeHook
+ bw.Reset(&wh)
+ bw.WriteByte(0)
+ bw.Flush()
+
+ bw.Reset(originalWriter)
+
+ return wh.p[:cap(wh.p)]
+}