[tor-commits] [flashproxy/master] Move WebSocket code to its own file.

dcf at torproject.org dcf at torproject.org
Wed Jan 30 05:11:38 UTC 2013


commit 74f37d9a32edee08cbbf3824dfc64eb9cfc6d7cc
Author: David Fifield <david at bamsoftware.com>
Date:   Sun Nov 25 22:51:56 2012 -0800

    Move WebSocket code to its own file.
---
 websocket-transport/Makefile            |    2 +-
 websocket-transport/websocket-server.go |  132 +-----------------------
 websocket-transport/websocket.go        |  172 +++++++++++++++++++++++++++++++
 3 files changed, 178 insertions(+), 128 deletions(-)

diff --git a/websocket-transport/Makefile b/websocket-transport/Makefile
index 1fb2f76..013debd 100644
--- a/websocket-transport/Makefile
+++ b/websocket-transport/Makefile
@@ -3,7 +3,7 @@ PROGRAMS = websocket-client websocket-server
 all: $(PROGRAMS)
 
 websocket-client: websocket-client.go socks.go pt.go
-websocket-server: websocket-server.go pt.go
+websocket-server: websocket-server.go pt.go websocket.go
 
 %: %.go
 	go build -o $@ $^
diff --git a/websocket-transport/websocket-server.go b/websocket-transport/websocket-server.go
index c6effe4..a2f3652 100644
--- a/websocket-transport/websocket-server.go
+++ b/websocket-transport/websocket-server.go
@@ -1,15 +1,11 @@
 package main
 
 import (
-	"bufio"
-	"crypto/sha1"
-	"encoding/base64"
 	"fmt"
 	"net"
 	"net/http"
 	"os"
 	"os/signal"
-	"strings"
 )
 
 const defaultPort = 9901
@@ -22,128 +18,8 @@ func logDebug(format string, v ...interface{}) {
 	fmt.Fprintf(os.Stderr, format+"\n", v...)
 }
 
-func httpError(w http.ResponseWriter, bufrw *bufio.ReadWriter, code int) {
-	w.Header().Set("Connection", "close")
-	bufrw.WriteString(fmt.Sprintf("HTTP/1.0 %d %s\r\n", code, http.StatusText(code)))
-	w.Header().Write(bufrw)
-	bufrw.WriteString("\r\n")
-	bufrw.Flush()
-}
-
-func commaSplit(s string) []string {
-	var result []string
-	if strings.TrimSpace(s) == "" {
-		return result
-	}
-	for _, e := range strings.Split(s, ",") {
-		result = append(result, strings.TrimSpace(e))
-	}
-	return result
-}
-
-func containsCase(haystack []string, needle string) bool {
-	for _, e := range haystack {
-		if strings.ToLower(e) == strings.ToLower(needle) {
-			return true
-		}
-	}
-	return false
-}
-
-func sha1Hash(data string) []byte {
-	h := sha1.New()
-	h.Write([]byte(data))
-	return h.Sum(nil)
-}
-
-func handler(w http.ResponseWriter, req *http.Request) {
-	conn, bufrw, err := w.(http.Hijacker).Hijack()
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
-	defer conn.Close()
-
-	// See RFC 6455 section 4.2.1 for this sequence of checks.
-
-	// 1. An HTTP/1.1 or higher GET request, including a "Request-URI"...
-	if req.Method != "GET" {
-		httpError(w, bufrw, http.StatusMethodNotAllowed)
-		return
-	}
-	if req.URL.Path != "/" {
-		httpError(w, bufrw, http.StatusNotFound)
-		return
-	}
-	// 2. A |Host| header field containing the server's authority.
-	// We deliberately skip this test.
-	// 3. An |Upgrade| header field containing the value "websocket",
-	// treated as an ASCII case-insensitive value.
-	if !containsCase(commaSplit(req.Header.Get("Upgrade")), "websocket") {
-		httpError(w, bufrw, http.StatusBadRequest)
-		return
-	}
-	// 4. A |Connection| header field that includes the token "Upgrade",
-	// treated as an ASCII case-insensitive value.
-	if !containsCase(commaSplit(req.Header.Get("Connection")), "Upgrade") {
-		httpError(w, bufrw, http.StatusBadRequest)
-		return
-	}
-	// 5. A |Sec-WebSocket-Key| header field with a base64-encoded value
-	// that, when decoded, is 16 bytes in length.
-	websocketKey := req.Header.Get("Sec-WebSocket-Key")
-	key, err := base64.StdEncoding.DecodeString(websocketKey)
-	if err != nil || len(key) != 16 {
-		httpError(w, bufrw, http.StatusBadRequest)
-		return
-	}
-	// 6. A |Sec-WebSocket-Version| header field, with a value of 13.
-	// We also allow 8 from draft-ietf-hybi-thewebsocketprotocol-10.
-	var knownVersions = []string{"8", "13"}
-	websocketVersion := req.Header.Get("Sec-WebSocket-Version")
-	if !containsCase(knownVersions, websocketVersion) {
-		// "If this version does not match a version understood by the
-		// server, the server MUST abort the WebSocket handshake
-		// described in this section and instead send an appropriate
-		// HTTP error code (such as 426 Upgrade Required) and a
-		// |Sec-WebSocket-Version| header field indicating the
-		// version(s) the server is capable of understanding."
-		w.Header().Set("Sec-WebSocket-Version", strings.Join(knownVersions, ", "))
-		httpError(w, bufrw, 426)
-		return
-	}
-	// 7. Optionally, an |Origin| header field.
-	// 8. Optionally, a |Sec-WebSocket-Protocol| header field, with a list of
-	// values indicating which protocols the client would like to speak, ordered
-	// by preference.
-	_ = commaSplit(req.Header.Get("Sec-WebSocket-Protocol"))
-	// 9. Optionally, a |Sec-WebSocket-Extensions| header field...
-	// 10. Optionally, other header fields...
-
-	// See RFC 6455 section 4.2.2, item 5 for these steps.
-
-	// 1. A Status-Line with a 101 response code as per RFC 2616.
-	bufrw.WriteString(fmt.Sprintf("HTTP/1.0 %d %s\r\n", http.StatusSwitchingProtocols, http.StatusText(http.StatusSwitchingProtocols)))
-	// 2. An |Upgrade| header field with value "websocket" as per RFC 2616.
-	w.Header().Set("Upgrade", "websocket")
-	// 3. A |Connection| header field with value "Upgrade".
-	w.Header().Set("Connection", "Upgrade")
-	// 4. A |Sec-WebSocket-Accept| header field.  The value of this header
-	// field is constructed by concatenating /key/, defined above in step 4
-	// in Section 4.2.2, with the string
-	// "258EAFA5-E914-47DA-95CA-C5AB0DC85B11", taking the SHA-1 hash of this
-	// concatenated value to obtain a 20-byte value and base64-encoding (see
-	// Section 4 of [RFC4648]) this 20-byte hash.
-	const magicGUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
-	acceptKey := base64.StdEncoding.EncodeToString(sha1Hash(websocketKey + magicGUID))
-	w.Header().Set("Sec-WebSocket-Accept", acceptKey)
-	// 5.  Optionally, a |Sec-WebSocket-Protocol| header field, with a value
-	// /subprotocol/ as defined in step 4 in Section 4.2.2.
-	// w.Header().Set("Sec-WebSocket-Protocol", "base64")
-	// 6.  Optionally, a |Sec-WebSocket-Extensions| header field...
-	w.Header().Write(bufrw)
-	bufrw.WriteString("\r\n")
-	bufrw.Flush()
+func websocketHandler(ws *websocket) {
+	fmt.Printf("blah\n")
 }
 
 func startListener(addr *net.TCPAddr) (*net.TCPListener, error) {
@@ -152,7 +28,9 @@ func startListener(addr *net.TCPAddr) (*net.TCPListener, error) {
 		return nil, err
 	}
 	go func() {
-		http.HandleFunc("/", handler)
+		var config websocketConfig
+		config.Subprotocols = []string{"base64"}
+		http.Handle("/", config.Handler(websocketHandler))
 		err = http.Serve(ln, nil)
 		if err != nil {
 			panic("http.Serve: " + err.Error())
diff --git a/websocket-transport/websocket.go b/websocket-transport/websocket.go
new file mode 100644
index 0000000..9ac9754
--- /dev/null
+++ b/websocket-transport/websocket.go
@@ -0,0 +1,172 @@
+package main
+
+import (
+	"bufio"
+	"crypto/sha1"
+	"encoding/base64"
+	"fmt"
+	"net"
+	"net/http"
+	"strings"
+)
+
+type websocketConfig struct {
+	Subprotocols []string
+}
+
+type websocket struct {
+	Conn        net.Conn
+	Bufrw       *bufio.ReadWriter
+	// Whether we are a client or a server implications for masking.
+	IsClient    bool
+	Subprotocol string
+}
+
+func commaSplit(s string) []string {
+	var result []string
+	if strings.TrimSpace(s) == "" {
+		return result
+	}
+	for _, e := range strings.Split(s, ",") {
+		result = append(result, strings.TrimSpace(e))
+	}
+	return result
+}
+
+func containsCase(haystack []string, needle string) bool {
+	for _, e := range haystack {
+		if strings.ToLower(e) == strings.ToLower(needle) {
+			return true
+		}
+	}
+	return false
+}
+
+func sha1Hash(data string) []byte {
+	h := sha1.New()
+	h.Write([]byte(data))
+	return h.Sum(nil)
+}
+
+func httpError(w http.ResponseWriter, bufrw *bufio.ReadWriter, code int) {
+	w.Header().Set("Connection", "close")
+	bufrw.WriteString(fmt.Sprintf("HTTP/1.0 %d %s\r\n", code, http.StatusText(code)))
+	w.Header().Write(bufrw)
+	bufrw.WriteString("\r\n")
+	bufrw.Flush()
+}
+
+type WebSocketHTTPHandler struct {
+	config            *websocketConfig
+	websocketCallback func(*websocket)
+}
+
+func (handler *WebSocketHTTPHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	conn, bufrw, err := w.(http.Hijacker).Hijack()
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	defer conn.Close()
+
+	// See RFC 6455 section 4.2.1 for this sequence of checks.
+
+	// 1. An HTTP/1.1 or higher GET request, including a "Request-URI"...
+	if req.Method != "GET" {
+		httpError(w, bufrw, http.StatusMethodNotAllowed)
+		return
+	}
+	if req.URL.Path != "/" {
+		httpError(w, bufrw, http.StatusNotFound)
+		return
+	}
+	// 2. A |Host| header field containing the server's authority.
+	// We deliberately skip this test.
+	// 3. An |Upgrade| header field containing the value "websocket",
+	// treated as an ASCII case-insensitive value.
+	if !containsCase(commaSplit(req.Header.Get("Upgrade")), "websocket") {
+		httpError(w, bufrw, http.StatusBadRequest)
+		return
+	}
+	// 4. A |Connection| header field that includes the token "Upgrade",
+	// treated as an ASCII case-insensitive value.
+	if !containsCase(commaSplit(req.Header.Get("Connection")), "Upgrade") {
+		httpError(w, bufrw, http.StatusBadRequest)
+		return
+	}
+	// 5. A |Sec-WebSocket-Key| header field with a base64-encoded value
+	// that, when decoded, is 16 bytes in length.
+	websocketKey := req.Header.Get("Sec-WebSocket-Key")
+	key, err := base64.StdEncoding.DecodeString(websocketKey)
+	if err != nil || len(key) != 16 {
+		httpError(w, bufrw, http.StatusBadRequest)
+		return
+	}
+	// 6. A |Sec-WebSocket-Version| header field, with a value of 13.
+	// We also allow 8 from draft-ietf-hybi-thewebsocketprotocol-10.
+	var knownVersions = []string{"8", "13"}
+	websocketVersion := req.Header.Get("Sec-WebSocket-Version")
+	if !containsCase(knownVersions, websocketVersion) {
+		// "If this version does not match a version understood by the
+		// server, the server MUST abort the WebSocket handshake
+		// described in this section and instead send an appropriate
+		// HTTP error code (such as 426 Upgrade Required) and a
+		// |Sec-WebSocket-Version| header field indicating the
+		// version(s) the server is capable of understanding."
+		w.Header().Set("Sec-WebSocket-Version", strings.Join(knownVersions, ", "))
+		httpError(w, bufrw, 426)
+		return
+	}
+	// 7. Optionally, an |Origin| header field.
+	// 8. Optionally, a |Sec-WebSocket-Protocol| header field, with a list of
+	// values indicating which protocols the client would like to speak, ordered
+	// by preference.
+	clientProtocols := commaSplit(req.Header.Get("Sec-WebSocket-Protocol"))
+	// 9. Optionally, a |Sec-WebSocket-Extensions| header field...
+	// 10. Optionally, other header fields...
+
+	var ws websocket
+	ws.Conn = conn
+	ws.Bufrw = bufrw
+	ws.IsClient = false
+
+	// See RFC 6455 section 4.2.2, item 5 for these steps.
+
+	// 1. A Status-Line with a 101 response code as per RFC 2616.
+	bufrw.WriteString(fmt.Sprintf("HTTP/1.0 %d %s\r\n", http.StatusSwitchingProtocols, http.StatusText(http.StatusSwitchingProtocols)))
+	// 2. An |Upgrade| header field with value "websocket" as per RFC 2616.
+	w.Header().Set("Upgrade", "websocket")
+	// 3. A |Connection| header field with value "Upgrade".
+	w.Header().Set("Connection", "Upgrade")
+	// 4. A |Sec-WebSocket-Accept| header field.  The value of this header
+	// field is constructed by concatenating /key/, defined above in step 4
+	// in Section 4.2.2, with the string
+	// "258EAFA5-E914-47DA-95CA-C5AB0DC85B11", taking the SHA-1 hash of this
+	// concatenated value to obtain a 20-byte value and base64-encoding (see
+	// Section 4 of [RFC4648]) this 20-byte hash.
+	const magicGUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
+	acceptKey := base64.StdEncoding.EncodeToString(sha1Hash(websocketKey + magicGUID))
+	w.Header().Set("Sec-WebSocket-Accept", acceptKey)
+	// 5.  Optionally, a |Sec-WebSocket-Protocol| header field, with a value
+	// /subprotocol/ as defined in step 4 in Section 4.2.2.
+	for _, clientProto := range clientProtocols {
+		for _, serverProto := range handler.config.Subprotocols {
+			if clientProto == serverProto {
+				ws.Subprotocol = clientProto
+				w.Header().Set("Sec-WebSocket-Protocol", clientProto)
+				break
+			}
+		}
+	}
+	// 6.  Optionally, a |Sec-WebSocket-Extensions| header field...
+	w.Header().Write(bufrw)
+	bufrw.WriteString("\r\n")
+	bufrw.Flush()
+
+	// Call the WebSocket-specific handler.
+	handler.websocketCallback(&ws)
+}
+
+func (config *websocketConfig) Handler(f func(*websocket)) http.Handler {
+	return &WebSocketHTTPHandler{config, f}
+}





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