Implement HttpIceConfigRequest

remoting/protocol/http_ice_config_request.cc

+// Copyright 2016 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 "remoting/protocol/http_ice_config_request.h"
+
+#include "base/bind.h"
+#include "base/callback_helpers.h"
+#include "base/json/json_reader.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
+#include "base/values.h"
+#include "net/base/url_util.h"
+#include "remoting/protocol/ice_config.h"
+
+namespace remoting {
+namespace protocol {
+
+namespace {
+
+// Ensure ICE config is correct at least one hour after session starts.
+const int kMinimumConfigLifetimeSeconds = 3600;
+
+// See draft-petithuguenin-behave-turn-uris-01.
+const int kDefaultStunTurnPort = 3478;
+const int kDefaultTurnsPort = 5349;
+
+bool ParseLifetime(const std::string& string, base::TimeDelta* result) {
+  double seconds = 0;
+  if (!base::EndsWith(string, "s", base::CompareCase::INSENSITIVE_ASCII) ||
+      !base::StringToDouble(string.substr(0, string.size() - 1), &seconds)) {
+    return false;
+  }
+  *result = base::TimeDelta::FromSecondsD(seconds);
+  return true;
+}
+
+// Parses url in form of <stun|turn|turns>:<host>[:<port>][?transport=<udp|tcp>]
+// and adds an entry to the |config|.
+bool AddServerToConfig(std::string url,
+                       const std::string& username,
+                       const std::string& password,
+                       IceConfig* config) {
+  cricket::ProtocolType turn_transport_type = cricket::PROTO_LAST;
+
+  const char kTcpTransportSuffix[] = "?transport=tcp";
+  const char kUdpTransportSuffix[] = "?transport=udp";
+  if (base::EndsWith(url, kTcpTransportSuffix,
+                     base::CompareCase::INSENSITIVE_ASCII)) {
+    turn_transport_type = cricket::PROTO_TCP;
+    url.resize(url.size() - strlen(kTcpTransportSuffix));
+  } else if (base::EndsWith(url, kUdpTransportSuffix,
+                            base::CompareCase::INSENSITIVE_ASCII)) {
+    turn_transport_type = cricket::PROTO_UDP;
+    url.resize(url.size() - strlen(kUdpTransportSuffix));
+  }
+
+  size_t colon_pos = url.find(':');
+  if (colon_pos == std::string::npos)
+    return false;
+
+  std::string protocol = url.substr(0, colon_pos);
+
+  std::string host;
+  int port;
+  if (!net::ParseHostAndPort(url.substr(colon_pos + 1), &host, &port))
+    return false;
+
+  if (protocol == "stun") {
+    if (port == -1)
+      port = kDefaultStunTurnPort;
+    config->stun_servers.push_back(rtc::SocketAddress(host, port));
+  } else if (protocol == "turn") {
+    if (port == -1)
+      port = kDefaultStunTurnPort;
+    if (turn_transport_type == cricket::PROTO_LAST)
+      turn_transport_type = cricket::PROTO_UDP;
+    config->turn_servers.push_back(cricket::RelayServerConfig(
+        host, port, username, password, turn_transport_type, false));
+  } else if (protocol == "turns") {
+    if (port == -1)
+      port = kDefaultTurnsPort;
+    if (turn_transport_type == cricket::PROTO_LAST)
+      turn_transport_type = cricket::PROTO_TCP;
+    config->turn_servers.push_back(cricket::RelayServerConfig(
+        host, port, username, password, turn_transport_type, true));
+  } else {
+    return false;
+  }
+
+  return true;
+}
+
+}  // namespace
+
+HttpIceConfigRequest::HttpIceConfigRequest(
+    UrlRequestFactory* url_request_factory,
+    const std::string& url)
+    : url_(url) {
+  url_request_ =
+      url_request_factory->CreateUrlRequest(UrlRequest::Type::POST, url_);
+  url_request_->SetPostData("application/json", "");
+}
+
+HttpIceConfigRequest::~HttpIceConfigRequest() {}
+
+void HttpIceConfigRequest::Send(const OnIceConfigCallback& callback) {
+  DCHECK(on_ice_config_callback_.is_null());
+  DCHECK(!callback.is_null());
+
+  on_ice_config_callback_ = callback;
+  url_request_->Start(
+      base::Bind(&HttpIceConfigRequest::OnResponse, base::Unretained(this)));
+}
+
+void HttpIceConfigRequest::OnResponse(const UrlRequest::Result& result) {
+  DCHECK(!on_ice_config_callback_.is_null());
+
+  if (!result.success) {
+    LOG(ERROR) << "Failed to fetch " << url_;
+    base::ResetAndReturn(&on_ice_config_callback_).Run(IceConfig());
+    return;
+  }
+
+  if (result.status != 200) {
+    LOG(ERROR) << "Received status code " << result.status << " from " << url_
+               << ": " << result.response_body;
+    base::ResetAndReturn(&on_ice_config_callback_).Run(IceConfig());
+    return;
+  }
+
+  scoped_ptr<base::Value> json = base::JSONReader::Read(result.response_body);
+  base::DictionaryValue* dictionary = nullptr;
+  base::ListValue* ice_servers_list = nullptr;
+  if (!json || !json->GetAsDictionary(&dictionary) ||
+      !dictionary->GetList("iceServers", &ice_servers_list)) {
+    LOG(ERROR) << "Received invalid response from " << url_ << ": "
+               << result.response_body;
+    base::ResetAndReturn(&on_ice_config_callback_).Run(IceConfig());
+    return;
+  }
+
+  IceConfig ice_config;
+
+  // Parse lifetimeDuration field.
+  std::string lifetime_str;
+  base::TimeDelta lifetime;
+  if (!dictionary->GetString("lifetimeDuration", &lifetime_str) ||
+      !ParseLifetime(lifetime_str, &lifetime)) {
+    LOG(ERROR) << "Received invalid lifetimeDuration value: " << lifetime_str;
+
+    // If the |lifetimeDuration| field is missing or cannot be parsed then mark
+    // the config as expired so it will refreshed for the next session.
+    ice_config.expiration_time = base::Time::Now();
+  } else {
+    ice_config.expiration_time =
+        base::Time::Now() + lifetime -
+        base::TimeDelta::FromSeconds(kMinimumConfigLifetimeSeconds);
+  }
+
+  // Parse iceServers list and store them in |ice_config|.
+  bool errors_found = false;
+  for (base::Value* server : *ice_servers_list) {
+    base::DictionaryValue* server_dict;
+    if (!server->GetAsDictionary(&server_dict)) {
+      errors_found = true;
+      continue;
+    }
+
+    base::ListValue* urls_list = nullptr;
+    if (!server_dict->GetList("urls", &urls_list)) {
+      errors_found = true;
+      continue;
+    }
+
+    std::string username;
+    server_dict->GetString("username", &username);
+
+    std::string password;
+    server_dict->GetString("credential", &password);
+
+    for (base::Value* url : *urls_list) {
+      std::string url_str;
+      if (!url->GetAsString(&url_str)) {
+        errors_found = true;
+        continue;
+      }
+      if (!AddServerToConfig(url_str, username, password, &ice_config)) {
+        LOG(ERROR) << "Invalid ICE server URL: " << url_str;
+      }
+    }
+  }
+
+  if (errors_found) {
+    LOG(ERROR) << "Received ICE config from the server that contained errors: "
+               << result.response_body;
+  }
+
+  // If there are no STUN or no TURN servers then mark the config as expired so
+  // it will refreshed for the next session.
+  if (errors_found || ice_config.stun_servers.empty() ||
+      ice_config.turn_servers.empty()) {
+    ice_config.expiration_time = base::Time::Now();
+  }
+
+  base::ResetAndReturn(&on_ice_config_callback_).Run(ice_config);
+}
+
+}  // namespace protocol
+}  // namespace remoting