Move DNS resolution from websocket-to-TCP proxy to ExtensionFunction

chrome/browser/chromeos/web_socket_proxy_helper.cc

+// Copyright (c) 2011 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 "chrome/browser/chromeos/web_socket_proxy_helper.h"
+
+#include "base/string_number_conversions.h"
+#include "base/logging.h"
+
+namespace chromeos {
+
+// static
+bool WebSocketProxyHelper::FetchPassportAddrNamePort(
+      uint8* begin, uint8* end,
+      std::string* passport, std::string* addr,
+      std::string* hostname, int* port) {
+  std::string input(begin, end);
+
+  // At first, get rid of a colon at the end.
+  if (input.empty() || input[input.length() - 1] != ':')
+    return false;
+  input.erase(input.length() - 1);
+
+  // Fetch the passport from the start.
+  if (!FetchToken(true, false, &input, passport) || passport->empty())
+    return false;
+
+  // Fetch the IP address from the start. Match '['-brackets if presented.
+  if (!FetchToken(true, true, &input, addr))
+    return false;
+
+  // Fetch the port number from the end.
+  std::string port_str;
+  if (!FetchToken(false, false, &input, &port_str) || port_str.empty() ||
+      !base::StringToInt(port_str, port) ||
+      *port <= 0 || *port >= (1<<16))
+    return false;
+
+  // The hostname is everything remained.
+  if (input.length() < 2 || input[input.length() - 1] != ':')
+    return false;
+  hostname->assign(input, 0, input.length() - 1);
+
+  return true;
+}
+
+// static
+bool WebSocketProxyHelper::FetchToken(bool forward,
+                                      bool match_brackets,
+                                      std::string* input,
+                                      std::string* token ) {
+  if (input->empty()) {
+    token->clear();
+  } else {
+    std::string separator =
+        (forward && match_brackets && input->at(0) == '[') ? "]:" : ":";
+    size_t pos = forward ? input->find(separator) : input->rfind(separator);
+    if (pos != std::string::npos) {
+      size_t start = forward ? 0 : pos + 1;
+      size_t end = forward ? pos : input->length();
+      token->assign(*input, start, end - start + separator.length() - 1);
+      input->erase(start, end - start + separator.length());
+    } else {
+      return false;
+    }
+  }
+  return true;
+}
+
+}  // namespace chromeos