Fix WebSocketServer extension parser.

net/server/web_socket.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/server/web_socket.h"
 
+#include <vector>
 #include "base/base64.h"
 #include "base/logging.h"
 #include "base/sha1.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/sys_byteorder.h"
 #include "net/server/http_connection.h"
 #include "net/server/http_server.h"
 #include "net/server/http_server_request_info.h"
 #include "net/server/http_server_response_info.h"
 #include "net/server/web_socket_encoder.h"
+#include "net/websockets/websocket_deflate_parameters.h"
+#include "net/websockets/websocket_extension.h"
+#include "net/websockets/websocket_handshake_constants.h"
 
 namespace net {
 
-WebSocket::WebSocket(HttpServer* server,
-                     HttpConnection* connection,
-                     const HttpServerRequestInfo& request)
-    : server_(server), connection_(connection), closed_(false) {
-  std::string request_extensions =
-      request.GetHeaderValue("sec-websocket-extensions");
-  encoder_.reset(WebSocketEncoder::CreateServer(request_extensions,
-                                                &response_extensions_));
-  if (!response_extensions_.empty()) {
-    response_extensions_ =
-        "Sec-WebSocket-Extensions: " + response_extensions_ + "\r\n";
-  }
+namespace {
+
+std::string ExtensionsHeaderString(
+    const std::vector<WebSocketExtension>& extensions) {
+  if (extensions.empty())
+    return std::string();
+
+  std::string result = "Sec-WebSocket-Extensions: " + extensions[0].ToString();
+  for (size_t i = 1; i < extensions.size(); ++i)
+    result += ", " + extensions[i].ToString();
+  return result + "\r\n";
 }
 
+std::string ValidResponseString(
+    const std::string& accept_hash,
+    const std::vector<WebSocketExtension> extensions) {
+  return base::StringPrintf(
+      "HTTP/1.1 101 WebSocket Protocol Handshake\r\n"
+      "Upgrade: WebSocket\r\n"
+      "Connection: Upgrade\r\n"
+      "Sec-WebSocket-Accept: %s\r\n"
+      "%s"
+      "\r\n",
+      accept_hash.c_str(), ExtensionsHeaderString(extensions).c_str());
+}
+
+}  // namespace
+
+WebSocket::WebSocket(HttpServer* server, HttpConnection* connection)
+    : server_(server), connection_(connection), closed_(false) {}
+
 WebSocket::~WebSocket() {}
 
-WebSocket* WebSocket::CreateWebSocket(HttpServer* server,
-                                      HttpConnection* connection,
-                                      const HttpServerRequestInfo& request) {
+void WebSocket::Accept(const HttpServerRequestInfo& request) {
   std::string version = request.GetHeaderValue("sec-websocket-version");
   if (version != "8" && version != "13") {
-    server->SendResponse(
-        connection->id(),
-        HttpServerResponseInfo::CreateFor500(
-            "Invalid request format. The version is not valid."));
-    return nullptr;
+    SendErrorResponse("Invalid request format. The version is not valid.");
+    return;
   }
 
   std::string key = request.GetHeaderValue("sec-websocket-key");
   if (key.empty()) {
-    server->SendResponse(
-        connection->id(),
-        HttpServerResponseInfo::CreateFor500(
-            "Invalid request format. Sec-WebSocket-Key is empty or isn't "
-            "specified."));
-    return nullptr;
+    SendErrorResponse(
+        "Invalid request format. Sec-WebSocket-Key is empty or isn't "
+        "specified.");
+    return;
   }
-  return new WebSocket(server, connection, request);
-}
+  std::string encoded_hash;
+  base::Base64Encode(base::SHA1HashString(key + websockets::kWebSocketGuid),
+                     &encoded_hash);
 
-void WebSocket::Accept(const HttpServerRequestInfo& request) {
-  static const char* const kWebSocketGuid =
-      "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
-  std::string key = request.GetHeaderValue("sec-websocket-key");
-  std::string data = base::StringPrintf("%s%s", key.c_str(), kWebSocketGuid);
-  std::string encoded_hash;
-  base::Base64Encode(base::SHA1HashString(data), &encoded_hash);
+  std::vector<WebSocketExtension> response_extensions;
+  auto i = request.headers.find("sec-websocket-extensions");
+  if (i == request.headers.end()) {
+    encoder_ = WebSocketEncoder::CreateServer();
+  } else {
+    std::string failure_message;
+    WebSocketDeflateParameters params;
+    encoder_ =
+        WebSocketEncoder::CreateServer(i->second, &params, &failure_message);
+    if (!encoder_) {
+      SendErrorResponse("Invalid extension offer: " + failure_message);
+      return;
+    }
+    response_extensions.push_back(params.AsExtension());
+  }
 
-  server_->SendRaw(
-      connection_->id(),
-      base::StringPrintf("HTTP/1.1 101 WebSocket Protocol Handshake\r\n"
-                         "Upgrade: WebSocket\r\n"
-                         "Connection: Upgrade\r\n"
-                         "Sec-WebSocket-Accept: %s\r\n"
-                         "%s"
-                         "\r\n",
-                         encoded_hash.c_str(), response_extensions_.c_str()));
+  server_->SendRaw(connection_->id(),
+                   ValidResponseString(encoded_hash, response_extensions));
 }
 
 WebSocket::ParseResult WebSocket::Read(std::string* message) {
+  if (closed_)
+    return FRAME_CLOSE;
+
   HttpConnection::ReadIOBuffer* read_buf = connection_->read_buf();
   base::StringPiece frame(read_buf->StartOfBuffer(), read_buf->GetSize());
   int bytes_consumed = 0;
   ParseResult result = encoder_->DecodeFrame(frame, &bytes_consumed, message);
   if (result == FRAME_OK)
     read_buf->DidConsume(bytes_consumed);
   if (result == FRAME_CLOSE)
     closed_ = true;
   return result;
 }
 
 void WebSocket::Send(const std::string& message) {
   if (closed_)
     return;
   std::string encoded;
   encoder_->EncodeFrame(message, 0, &encoded);
   server_->SendRaw(connection_->id(), encoded);
 }
 
+void WebSocket::SendErrorResponse(const std::string& message) {
+  if (closed_)
+    return;
+  closed_ = true;
+  server_->Send500(connection_->id(), message);
+}
+
 }  // namespace net