content/browser/download/base_file.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 "content/browser/download/base_file.h"
   6
   7 #include "base/bind.h"
   8 #include "base/files/file.h"
   9 #include "base/files/file_util.h"
  10 #include "base/format_macros.h"
  11 #include "base/logging.h"
  12 #include "base/pickle.h"
  13 #include "base/strings/stringprintf.h"
  14 #include "base/threading/thread_restrictions.h"
  15 #include "content/browser/download/download_interrupt_reasons_impl.h"
  16 #include "content/browser/download/download_net_log_parameters.h"
  17 #include "content/browser/download/download_stats.h"
  18 #include "content/public/browser/browser_thread.h"
  19 #include "content/public/browser/content_browser_client.h"
  20 #include "crypto/secure_hash.h"
  21 #include "net/base/net_errors.h"
  22
  23 namespace content {
  24
  25 // This will initialize the entire array to zero.
  26 const unsigned char BaseFile::kEmptySha256Hash[] = { 0 };
  27
  28 BaseFile::BaseFile(const base::FilePath& full_path,
  29                    const GURL& source_url,
  30                    const GURL& referrer_url,
  31                    int64 received_bytes,
  32                    bool calculate_hash,
  33                    const std::string& hash_state_bytes,
  34                    base::File file,
  35                    const net::BoundNetLog& bound_net_log)
  36     : full_path_(full_path),
  37       source_url_(source_url),
  38       referrer_url_(referrer_url),
  39       file_(file.Pass()),
  40       bytes_so_far_(received_bytes),
  41       start_tick_(base::TimeTicks::Now()),
  42       calculate_hash_(calculate_hash),
  43       detached_(false),
  44       bound_net_log_(bound_net_log) {
  45   memcpy(sha256_hash_, kEmptySha256Hash, crypto::kSHA256Length);
  46   if (calculate_hash_) {
  47     secure_hash_.reset(crypto::SecureHash::Create(crypto::SecureHash::SHA256));
  48     if ((bytes_so_far_ > 0) &&  // Not starting at the beginning.
  49         (!IsEmptyHash(hash_state_bytes))) {
  50       Pickle hash_state(hash_state_bytes.c_str(), hash_state_bytes.size());
  51       PickleIterator data_iterator(hash_state);
  52       secure_hash_->Deserialize(&data_iterator);
  53     }
  54   }
  55 }
  56
  57 BaseFile::~BaseFile() {
  58   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
  59   if (detached_)
  60     Close();
  61   else
  62     Cancel();  // Will delete the file.
  63 }
  64
  65 DownloadInterruptReason BaseFile::Initialize(
  66     const base::FilePath& default_directory) {
  67   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
  68   DCHECK(!detached_);
  69
  70   if (full_path_.empty()) {
  71     base::FilePath initial_directory(default_directory);
  72     base::FilePath temp_file;
  73     if (initial_directory.empty()) {
  74       initial_directory =
  75           GetContentClient()->browser()->GetDefaultDownloadDirectory();
  76     }
  77     // |initial_directory| can still be empty if ContentBrowserClient returned
  78     // an empty path for the downloads directory.
  79     if ((initial_directory.empty() ||
  80          !base::CreateTemporaryFileInDir(initial_directory, &temp_file)) &&
  81         !base::CreateTemporaryFile(&temp_file)) {
  82       return LogInterruptReason("Unable to create", 0,
  83                                 DOWNLOAD_INTERRUPT_REASON_FILE_FAILED);
  84     }
  85     full_path_ = temp_file;
  86   }
  87
  88   return Open();
  89 }
  90
  91 DownloadInterruptReason BaseFile::AppendDataToFile(const char* data,
  92                                                    size_t data_len) {
  93   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
  94   DCHECK(!detached_);
  95
  96   // NOTE(benwells): The above DCHECK won't be present in release builds,
  97   // so we log any occurences to see how common this error is in the wild.
  98   if (detached_)
  99     RecordDownloadCount(APPEND_TO_DETACHED_FILE_COUNT);
 100
 101   if (!file_.IsValid())
 102     return LogInterruptReason("No file stream on append", 0,
 103                               DOWNLOAD_INTERRUPT_REASON_FILE_FAILED);
 104
 105   // TODO(phajdan.jr): get rid of this check.
 106   if (data_len == 0)
 107     return DOWNLOAD_INTERRUPT_REASON_NONE;
 108
 109   // The Write call below is not guaranteed to write all the data.
 110   size_t write_count = 0;
 111   size_t len = data_len;
 112   const char* current_data = data;
 113   while (len > 0) {
 114     write_count++;
 115     int write_result = file_.WriteAtCurrentPos(current_data, len);
 116     DCHECK_NE(0, write_result);
 117
 118     // Report errors on file writes.
 119     if (write_result < 0)
 120       return LogSystemError("Write", logging::GetLastSystemErrorCode());
 121
 122     // Update status.
 123     size_t write_size = static_cast<size_t>(write_result);
 124     DCHECK_LE(write_size, len);
 125     len -= write_size;
 126     current_data += write_size;
 127     bytes_so_far_ += write_size;
 128   }
 129
 130   RecordDownloadWriteSize(data_len);
 131   RecordDownloadWriteLoopCount(write_count);
 132
 133   if (calculate_hash_)
 134     secure_hash_->Update(data, data_len);
 135
 136   return DOWNLOAD_INTERRUPT_REASON_NONE;
 137 }
 138
 139 DownloadInterruptReason BaseFile::Rename(const base::FilePath& new_path) {
 140   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
 141   DownloadInterruptReason rename_result = DOWNLOAD_INTERRUPT_REASON_NONE;
 142
 143   // If the new path is same as the old one, there is no need to perform the
 144   // following renaming logic.
 145   if (new_path == full_path_)
 146     return DOWNLOAD_INTERRUPT_REASON_NONE;
 147
 148   // Save the information whether the download is in progress because
 149   // it will be overwritten by closing the file.
 150   bool was_in_progress = in_progress();
 151
 152   bound_net_log_.BeginEvent(
 153       net::NetLog::TYPE_DOWNLOAD_FILE_RENAMED,
 154       base::Bind(&FileRenamedNetLogCallback, &full_path_, &new_path));
 155   Close();
 156   base::CreateDirectory(new_path.DirName());
 157
 158   // A simple rename wouldn't work here since we want the file to have
 159   // permissions / security descriptors that makes sense in the new directory.
 160   rename_result = MoveFileAndAdjustPermissions(new_path);
 161
 162   if (rename_result == DOWNLOAD_INTERRUPT_REASON_NONE)
 163     full_path_ = new_path;
 164
 165   // Re-open the file if we were still using it regardless of the interrupt
 166   // reason.
 167   DownloadInterruptReason open_result = DOWNLOAD_INTERRUPT_REASON_NONE;
 168   if (was_in_progress)
 169     open_result = Open();
 170
 171   bound_net_log_.EndEvent(net::NetLog::TYPE_DOWNLOAD_FILE_RENAMED);
 172   return rename_result == DOWNLOAD_INTERRUPT_REASON_NONE ? open_result
 173                                                          : rename_result;
 174 }
 175
 176 void BaseFile::Detach() {
 177   detached_ = true;
 178   bound_net_log_.AddEvent(net::NetLog::TYPE_DOWNLOAD_FILE_DETACHED);
 179 }
 180
 181 void BaseFile::Cancel() {
 182   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
 183   DCHECK(!detached_);
 184
 185   bound_net_log_.AddEvent(net::NetLog::TYPE_CANCELLED);
 186
 187   Close();
 188
 189   if (!full_path_.empty()) {
 190     bound_net_log_.AddEvent(net::NetLog::TYPE_DOWNLOAD_FILE_DELETED);
 191     base::DeleteFile(full_path_, false);
 192   }
 193
 194   Detach();
 195 }
 196
 197 void BaseFile::Finish() {
 198   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
 199
 200   if (calculate_hash_)
 201     secure_hash_->Finish(sha256_hash_, crypto::kSHA256Length);
 202
 203   Close();
 204 }
 205
 206 void BaseFile::SetClientGuid(const std::string& guid) {
 207   client_guid_ = guid;
 208 }
 209
 210 // OS_WIN, OS_MACOSX and OS_LINUX have specialized implementations.
 211 #if !defined(OS_WIN) && !defined(OS_MACOSX) && !defined(OS_LINUX)
 212 DownloadInterruptReason BaseFile::AnnotateWithSourceInformation() {
 213   return DOWNLOAD_INTERRUPT_REASON_NONE;
 214 }
 215 #endif
 216
 217 bool BaseFile::GetHash(std::string* hash) {
 218   DCHECK(!detached_);
 219   hash->assign(reinterpret_cast<const char*>(sha256_hash_),
 220                sizeof(sha256_hash_));
 221   return (calculate_hash_ && !in_progress());
 222 }
 223
 224 std::string BaseFile::GetHashState() {
 225   if (!calculate_hash_)
 226     return std::string();
 227
 228   Pickle hash_state;
 229   if (!secure_hash_->Serialize(&hash_state))
 230     return std::string();
 231
 232   return std::string(reinterpret_cast<const char*>(hash_state.data()),
 233                      hash_state.size());
 234 }
 235
 236 // static
 237 bool BaseFile::IsEmptyHash(const std::string& hash) {
 238   return (hash.size() == crypto::kSHA256Length &&
 239           0 == memcmp(hash.data(), kEmptySha256Hash, crypto::kSHA256Length));
 240 }
 241
 242 std::string BaseFile::DebugString() const {
 243   return base::StringPrintf("{ source_url_ = \"%s\""
 244                             " full_path_ = \"%" PRFilePath "\""
 245                             " bytes_so_far_ = %" PRId64
 246                             " detached_ = %c }",
 247                             source_url_.spec().c_str(),
 248                             full_path_.value().c_str(),
 249                             bytes_so_far_,
 250                             detached_ ? 'T' : 'F');
 251 }
 252
 253 DownloadInterruptReason BaseFile::Open() {
 254   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
 255   DCHECK(!detached_);
 256   DCHECK(!full_path_.empty());
 257
 258   bound_net_log_.BeginEvent(
 259       net::NetLog::TYPE_DOWNLOAD_FILE_OPENED,
 260       base::Bind(&FileOpenedNetLogCallback, &full_path_, bytes_so_far_));
 261
 262   // Create a new file if it is not provided.
 263   if (!file_.IsValid()) {
 264     file_.Initialize(
 265         full_path_, base::File::FLAG_OPEN_ALWAYS | base::File::FLAG_WRITE);
 266     if (!file_.IsValid()) {
 267       return LogNetError("Open",
 268                          net::FileErrorToNetError(file_.error_details()));
 269     }
 270   }
 271
 272   // We may be re-opening the file after rename. Always make sure we're
 273   // writing at the end of the file.
 274   int64 file_size = file_.Seek(base::File::FROM_END, 0);
 275   if (file_size < 0) {
 276     logging::SystemErrorCode error = logging::GetLastSystemErrorCode();
 277     ClearFile();
 278     return LogSystemError("Seek", error);
 279   } else if (file_size > bytes_so_far_) {
 280     // The file is larger than we expected.
 281     // This is OK, as long as we don't use the extra.
 282     // Truncate the file.
 283     if (!file_.SetLength(bytes_so_far_) ||
 284         file_.Seek(base::File::FROM_BEGIN, bytes_so_far_) != bytes_so_far_) {
 285       logging::SystemErrorCode error = logging::GetLastSystemErrorCode();
 286       ClearFile();
 287       return LogSystemError("Truncate",  error);
 288     }
 289   } else if (file_size < bytes_so_far_) {
 290     // The file is shorter than we expected.  Our hashes won't be valid.
 291     ClearFile();
 292     return LogInterruptReason("Unable to seek to last written point", 0,
 293                               DOWNLOAD_INTERRUPT_REASON_FILE_TOO_SHORT);
 294   }
 295
 296   return DOWNLOAD_INTERRUPT_REASON_NONE;
 297 }
 298
 299 void BaseFile::Close() {
 300   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
 301
 302   bound_net_log_.AddEvent(net::NetLog::TYPE_DOWNLOAD_FILE_CLOSED);
 303
 304   if (file_.IsValid()) {
 305     // Currently we don't really care about the return value, since if it fails
 306     // theres not much we can do.  But we might in the future.
 307     file_.Flush();
 308     ClearFile();
 309   }
 310 }
 311
 312 void BaseFile::ClearFile() {
 313   // This should only be called when we have a stream.
 314   DCHECK(file_.IsValid());
 315   file_.Close();
 316   bound_net_log_.EndEvent(net::NetLog::TYPE_DOWNLOAD_FILE_OPENED);
 317 }
 318
 319 DownloadInterruptReason BaseFile::LogNetError(
 320     const char* operation,
 321     net::Error error) {
 322   bound_net_log_.AddEvent(
 323       net::NetLog::TYPE_DOWNLOAD_FILE_ERROR,
 324       base::Bind(&FileErrorNetLogCallback, operation, error));
 325   return ConvertNetErrorToInterruptReason(error, DOWNLOAD_INTERRUPT_FROM_DISK);
 326 }
 327
 328 DownloadInterruptReason BaseFile::LogSystemError(
 329     const char* operation,
 330     logging::SystemErrorCode os_error) {
 331   // There's no direct conversion from a system error to an interrupt reason.
 332   base::File::Error file_error = base::File::OSErrorToFileError(os_error);
 333   return LogInterruptReason(
 334       operation, os_error,
 335       ConvertFileErrorToInterruptReason(file_error));
 336 }
 337
 338 DownloadInterruptReason BaseFile::LogInterruptReason(
 339     const char* operation,
 340     int os_error,
 341     DownloadInterruptReason reason) {
 342   bound_net_log_.AddEvent(
 343       net::NetLog::TYPE_DOWNLOAD_FILE_ERROR,
 344       base::Bind(&FileInterruptedNetLogCallback, operation, os_error, reason));
 345   return reason;
 346 }
 347
 348 }  // namespace content