sync/engine/net/server_connection_manager.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "sync/engine/net/server_connection_manager.h"
   6
   7 #include <errno.h>
   8
   9 #include <ostream>
  10 #include <string>
  11 #include <vector>
  12
  13 #include "base/metrics/histogram.h"
  14 #include "build/build_config.h"
  15 #include "net/base/net_errors.h"
  16 #include "net/http/http_status_code.h"
  17 #include "sync/engine/net/url_translator.h"
  18 #include "sync/engine/syncer.h"
  19 #include "sync/internal_api/public/base/cancelation_signal.h"
  20 #include "sync/protocol/sync.pb.h"
  21 #include "sync/syncable/directory.h"
  22 #include "url/gurl.h"
  23
  24 namespace syncer {
  25
  26 using std::ostream;
  27 using std::string;
  28 using std::vector;
  29
  30 static const char kSyncServerSyncPath[] = "/command/";
  31
  32 HttpResponse::HttpResponse()
  33     : response_code(kUnsetResponseCode),
  34       content_length(kUnsetContentLength),
  35       payload_length(kUnsetPayloadLength),
  36       server_status(NONE) {}
  37
  38 #define ENUM_CASE(x) case x: return #x; break
  39
  40 const char* HttpResponse::GetServerConnectionCodeString(
  41     ServerConnectionCode code) {
  42   switch (code) {
  43     ENUM_CASE(NONE);
  44     ENUM_CASE(CONNECTION_UNAVAILABLE);
  45     ENUM_CASE(IO_ERROR);
  46     ENUM_CASE(SYNC_SERVER_ERROR);
  47     ENUM_CASE(SYNC_AUTH_ERROR);
  48     ENUM_CASE(SERVER_CONNECTION_OK);
  49     ENUM_CASE(RETRY);
  50   }
  51   NOTREACHED();
  52   return "";
  53 }
  54
  55 #undef ENUM_CASE
  56
  57 // TODO(clamy): check if all errors are in the right category.
  58 HttpResponse::ServerConnectionCode
  59 HttpResponse::ServerConnectionCodeFromNetError(int error_code) {
  60   switch (error_code) {
  61     case net::ERR_ABORTED:
  62     case net::ERR_SOCKET_NOT_CONNECTED:
  63     case net::ERR_NETWORK_CHANGED:
  64     case net::ERR_CONNECTION_FAILED:
  65     case net::ERR_NAME_NOT_RESOLVED:
  66     case net::ERR_INTERNET_DISCONNECTED:
  67     case net::ERR_NETWORK_ACCESS_DENIED:
  68     case net::ERR_NETWORK_IO_SUSPENDED:
  69       return CONNECTION_UNAVAILABLE;
  70   }
  71   return IO_ERROR;
  72 }
  73
  74 ServerConnectionManager::Connection::Connection(
  75     ServerConnectionManager* scm) : scm_(scm) {
  76 }
  77
  78 ServerConnectionManager::Connection::~Connection() {
  79 }
  80
  81 bool ServerConnectionManager::Connection::ReadBufferResponse(
  82     string* buffer_out,
  83     HttpResponse* response,
  84     bool require_response) {
  85   if (net::HTTP_OK != response->response_code) {
  86     response->server_status = HttpResponse::SYNC_SERVER_ERROR;
  87     return false;
  88   }
  89
  90   if (require_response && (1 > response->content_length))
  91     return false;
  92
  93   const int64 bytes_read = ReadResponse(buffer_out,
  94       static_cast<int>(response->content_length));
  95   if (bytes_read != response->content_length) {
  96     response->server_status = HttpResponse::IO_ERROR;
  97     return false;
  98   }
  99   return true;
 100 }
 101
 102 bool ServerConnectionManager::Connection::ReadDownloadResponse(
 103     HttpResponse* response,
 104     string* buffer_out) {
 105   const int64 bytes_read = ReadResponse(buffer_out,
 106       static_cast<int>(response->content_length));
 107
 108   if (bytes_read != response->content_length) {
 109     LOG(ERROR) << "Mismatched content lengths, server claimed " <<
 110         response->content_length << ", but sent " << bytes_read;
 111     response->server_status = HttpResponse::IO_ERROR;
 112     return false;
 113   }
 114   return true;
 115 }
 116
 117 ServerConnectionManager::ScopedConnectionHelper::ScopedConnectionHelper(
 118     ServerConnectionManager* manager, Connection* connection)
 119     : manager_(manager), connection_(connection) {}
 120
 121 ServerConnectionManager::ScopedConnectionHelper::~ScopedConnectionHelper() {
 122   if (connection_)
 123     manager_->OnConnectionDestroyed(connection_.get());
 124   connection_.reset();
 125 }
 126
 127 ServerConnectionManager::Connection*
 128 ServerConnectionManager::ScopedConnectionHelper::get() {
 129   return connection_.get();
 130 }
 131
 132 namespace {
 133
 134 string StripTrailingSlash(const string& s) {
 135   int stripped_end_pos = s.size();
 136   if (s.at(stripped_end_pos - 1) == '/') {
 137     stripped_end_pos = stripped_end_pos - 1;
 138   }
 139
 140   return s.substr(0, stripped_end_pos);
 141 }
 142
 143 }  // namespace
 144
 145 // TODO(chron): Use a GURL instead of string concatenation.
 146 string ServerConnectionManager::Connection::MakeConnectionURL(
 147     const string& sync_server,
 148     const string& path,
 149     bool use_ssl) const {
 150   string connection_url = (use_ssl ? "https://" : "http://");
 151   connection_url += sync_server;
 152   connection_url = StripTrailingSlash(connection_url);
 153   connection_url += path;
 154
 155   return connection_url;
 156 }
 157
 158 int ServerConnectionManager::Connection::ReadResponse(string* out_buffer,
 159                                                       int length) {
 160   int bytes_read = buffer_.length();
 161   CHECK(length <= bytes_read);
 162   out_buffer->assign(buffer_);
 163   return bytes_read;
 164 }
 165
 166 ScopedServerStatusWatcher::ScopedServerStatusWatcher(
 167     ServerConnectionManager* conn_mgr, HttpResponse* response)
 168     : conn_mgr_(conn_mgr),
 169       response_(response) {
 170   response->server_status = conn_mgr->server_status_;
 171 }
 172
 173 ScopedServerStatusWatcher::~ScopedServerStatusWatcher() {
 174   conn_mgr_->SetServerStatus(response_->server_status);
 175 }
 176
 177 ServerConnectionManager::ServerConnectionManager(
 178     const string& server,
 179     int port,
 180     bool use_ssl,
 181     CancelationSignal* cancelation_signal)
 182     : sync_server_(server),
 183       sync_server_port_(port),
 184       use_ssl_(use_ssl),
 185       proto_sync_path_(kSyncServerSyncPath),
 186       server_status_(HttpResponse::NONE),
 187       terminated_(false),
 188       active_connection_(NULL),
 189       cancelation_signal_(cancelation_signal),
 190       signal_handler_registered_(false) {
 191   signal_handler_registered_ = cancelation_signal_->TryRegisterHandler(this);
 192   if (!signal_handler_registered_) {
 193     // Calling a virtual function from a constructor.  We can get away with it
 194     // here because ServerConnectionManager::OnSignalReceived() is the function
 195     // we want to call.
 196     OnSignalReceived();
 197   }
 198 }
 199
 200 ServerConnectionManager::~ServerConnectionManager() {
 201   if (signal_handler_registered_) {
 202     cancelation_signal_->UnregisterHandler(this);
 203   }
 204 }
 205
 206 ServerConnectionManager::Connection*
 207 ServerConnectionManager::MakeActiveConnection() {
 208   base::AutoLock lock(terminate_connection_lock_);
 209   DCHECK(!active_connection_);
 210   if (terminated_)
 211     return NULL;
 212
 213   active_connection_ = MakeConnection();
 214   return active_connection_;
 215 }
 216
 217 void ServerConnectionManager::OnConnectionDestroyed(Connection* connection) {
 218   DCHECK(connection);
 219   base::AutoLock lock(terminate_connection_lock_);
 220   // |active_connection_| can be NULL already if it was aborted. Also,
 221   // it can legitimately be a different Connection object if a new Connection
 222   // was created after a previous one was Aborted and destroyed.
 223   if (active_connection_ != connection)
 224     return;
 225
 226   active_connection_ = NULL;
 227 }
 228
 229 bool ServerConnectionManager::SetAuthToken(const std::string& auth_token) {
 230   DCHECK(thread_checker_.CalledOnValidThread());
 231   if (previously_invalidated_token != auth_token) {
 232     auth_token_.assign(auth_token);
 233     previously_invalidated_token = std::string();
 234     return true;
 235   }
 236
 237   // This could happen in case like server outage/bug. E.g. token returned by
 238   // first request is considered invalid by sync server and because
 239   // of token server's caching policy, etc, same token is returned on second
 240   // request. Need to notify sync frontend again to request new token,
 241   // otherwise backend will stay in SYNC_AUTH_ERROR state while frontend thinks
 242   // everything is fine and takes no actions.
 243   SetServerStatus(HttpResponse::SYNC_AUTH_ERROR);
 244   return false;
 245 }
 246
 247 void ServerConnectionManager::InvalidateAndClearAuthToken() {
 248   DCHECK(thread_checker_.CalledOnValidThread());
 249   // Copy over the token to previous invalid token.
 250   if (!auth_token_.empty()) {
 251     previously_invalidated_token.assign(auth_token_);
 252     auth_token_ = std::string();
 253   }
 254 }
 255
 256 void ServerConnectionManager::SetServerStatus(
 257     HttpResponse::ServerConnectionCode server_status) {
 258   // SYNC_AUTH_ERROR is permanent error. Need to notify observer to take
 259   // action externally to resolve.
 260   if (server_status != HttpResponse::SYNC_AUTH_ERROR &&
 261       server_status_ == server_status) {
 262     return;
 263   }
 264   server_status_ = server_status;
 265   NotifyStatusChanged();
 266 }
 267
 268 void ServerConnectionManager::NotifyStatusChanged() {
 269   DCHECK(thread_checker_.CalledOnValidThread());
 270   FOR_EACH_OBSERVER(ServerConnectionEventListener, listeners_,
 271      OnServerConnectionEvent(
 272          ServerConnectionEvent(server_status_)));
 273 }
 274
 275 bool ServerConnectionManager::PostBufferWithCachedAuth(
 276     PostBufferParams* params, ScopedServerStatusWatcher* watcher) {
 277   DCHECK(thread_checker_.CalledOnValidThread());
 278   string path =
 279       MakeSyncServerPath(proto_sync_path(), MakeSyncQueryString(client_id_));
 280   return PostBufferToPath(params, path, auth_token(), watcher);
 281 }
 282
 283 bool ServerConnectionManager::PostBufferToPath(PostBufferParams* params,
 284     const string& path, const string& auth_token,
 285     ScopedServerStatusWatcher* watcher) {
 286   DCHECK(thread_checker_.CalledOnValidThread());
 287   DCHECK(watcher != NULL);
 288
 289   // TODO(pavely): crbug.com/273096. Check for "credentials_lost" is added as
 290   // workaround for M29 blocker to avoid sending RPC to sync with known invalid
 291   // token but instead to trigger refreshing token in ProfileSyncService. Need
 292   // to clean it.
 293   if (auth_token.empty() || auth_token == "credentials_lost") {
 294     params->response.server_status = HttpResponse::SYNC_AUTH_ERROR;
 295     // Print a log to distinguish this "known failure" from others.
 296     LOG(WARNING) << "ServerConnectionManager forcing SYNC_AUTH_ERROR";
 297     return false;
 298   }
 299
 300   // When our connection object falls out of scope, it clears itself from
 301   // active_connection_.
 302   ScopedConnectionHelper post(this, MakeActiveConnection());
 303   if (!post.get()) {
 304     params->response.server_status = HttpResponse::CONNECTION_UNAVAILABLE;
 305     return false;
 306   }
 307
 308   // Note that |post| may be aborted by now, which will just cause Init to fail
 309   // with CONNECTION_UNAVAILABLE.
 310   bool ok = post.get()->Init(
 311       path.c_str(), auth_token, params->buffer_in, &params->response);
 312
 313   if (params->response.server_status == HttpResponse::SYNC_AUTH_ERROR) {
 314     InvalidateAndClearAuthToken();
 315   }
 316
 317   if (!ok || net::HTTP_OK != params->response.response_code)
 318     return false;
 319
 320   if (post.get()->ReadBufferResponse(
 321       &params->buffer_out, &params->response, true)) {
 322     params->response.server_status = HttpResponse::SERVER_CONNECTION_OK;
 323     return true;
 324   }
 325   return false;
 326 }
 327
 328 // Returns the current server parameters in server_url and port.
 329 void ServerConnectionManager::GetServerParameters(string* server_url,
 330                                                   int* port,
 331                                                   bool* use_ssl) const {
 332   if (server_url != NULL)
 333     *server_url = sync_server_;
 334   if (port != NULL)
 335     *port = sync_server_port_;
 336   if (use_ssl != NULL)
 337     *use_ssl = use_ssl_;
 338 }
 339
 340 std::string ServerConnectionManager::GetServerHost() const {
 341   string server_url;
 342   int port;
 343   bool use_ssl;
 344   GetServerParameters(&server_url, &port, &use_ssl);
 345   // For unit tests.
 346   if (server_url.empty())
 347     return std::string();
 348   // We just want the hostname, so we don't need to switch on use_ssl.
 349   server_url = "http://" + server_url;
 350   GURL gurl(server_url);
 351   DCHECK(gurl.is_valid()) << gurl;
 352   return gurl.host();
 353 }
 354
 355 void ServerConnectionManager::AddListener(
 356     ServerConnectionEventListener* listener) {
 357   DCHECK(thread_checker_.CalledOnValidThread());
 358   listeners_.AddObserver(listener);
 359 }
 360
 361 void ServerConnectionManager::RemoveListener(
 362     ServerConnectionEventListener* listener) {
 363   DCHECK(thread_checker_.CalledOnValidThread());
 364   listeners_.RemoveObserver(listener);
 365 }
 366
 367 ServerConnectionManager::Connection* ServerConnectionManager::MakeConnection()
 368 {
 369   return NULL;  // For testing.
 370 }
 371
 372 void ServerConnectionManager::OnSignalReceived() {
 373   base::AutoLock lock(terminate_connection_lock_);
 374   terminated_ = true;
 375   if (active_connection_)
 376     active_connection_->Abort();
 377
 378   // Sever our ties to this connection object. Note that it still may exist,
 379   // since we don't own it, but it has been neutered.
 380   active_connection_ = NULL;
 381 }
 382
 383 std::ostream& operator << (std::ostream& s, const struct HttpResponse& hr) {
 384   s << " Response Code (bogus on error): " << hr.response_code;
 385   s << " Content-Length (bogus on error): " << hr.content_length;
 386   s << " Server Status: "
 387     << HttpResponse::GetServerConnectionCodeString(hr.server_status);
 388   return s;
 389 }
 390
 391 }  // namespace syncer