The Tor Browser: security/sandbox/chromium/base/file

security/sandbox/chromium/base/file_util.h@141e0f1194b1 (annotated)

security/sandbox/chromium/base/file_util.h

Wed, 31 Dec 2014 07:16:47 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 07:16:47 +0100
branch: TOR_BUG_9701
changeset 3: 141e0f1194b1
permissions: -rw-r--r--

Revert simplistic fix pending revisit of Mozilla integration attempt.

 // 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.
 // This file contains utility functions for dealing with the local
 // filesystem.
 #ifndef BASE_FILE_UTIL_H_
 #define BASE_FILE_UTIL_H_
 #include "build/build_config.h"
 #if defined(OS_WIN)
 #include <windows.h>
 #elif defined(OS_POSIX)
 #include <sys/stat.h>
 #include <unistd.h>
 #endif
 #include <stdio.h>
 #include <set>
 #include <string>
 #include <vector>
 #include "base/base_export.h"
 #include "base/basictypes.h"
 #include "base/files/file_path.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/platform_file.h"
 #include "base/strings/string16.h"
 #if defined(OS_POSIX)
 #include "base/file_descriptor_posix.h"
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
 #endif
 namespace base {
 class Time;
 extern bool g_bug108724_debug;
 //-----------------------------------------------------------------------------
 // Functions that involve filesystem access or modification:
 // Returns an absolute version of a relative path. Returns an empty path on
 // error. On POSIX, this function fails if the path does not exist. This
 // function can result in I/O so it can be slow.
 BASE_EXPORT FilePath MakeAbsoluteFilePath(const FilePath& input);
 // Returns the total number of bytes used by all the files under |root_path|.
 // If the path does not exist the function returns 0.
 //
 // This function is implemented using the FileEnumerator class so it is not
 // particularly speedy in any platform.
 BASE_EXPORT int64 ComputeDirectorySize(const FilePath& root_path);
 // Deletes the given path, whether it's a file or a directory.
 // If it's a directory, it's perfectly happy to delete all of the
 // directory's contents.  Passing true to recursive deletes
 // subdirectories and their contents as well.
 // Returns true if successful, false otherwise. It is considered successful
 // to attempt to delete a file that does not exist.
 //
 // In posix environment and if |path| is a symbolic link, this deletes only
 // the symlink. (even if the symlink points to a non-existent file)
 //
 // WARNING: USING THIS WITH recursive==true IS EQUIVALENT
 //          TO "rm -rf", SO USE WITH CAUTION.
 BASE_EXPORT bool DeleteFile(const FilePath& path, bool recursive);
 #if defined(OS_WIN)
 // Schedules to delete the given path, whether it's a file or a directory, until
 // the operating system is restarted.
 // Note:
 // 1) The file/directory to be deleted should exist in a temp folder.
 // 2) The directory to be deleted must be empty.
 BASE_EXPORT bool DeleteFileAfterReboot(const FilePath& path);
 #endif
 // Moves the given path, whether it's a file or a directory.
 // If a simple rename is not possible, such as in the case where the paths are
 // on different volumes, this will attempt to copy and delete. Returns
 // true for success.
 // This function fails if either path contains traversal components ('..').
 BASE_EXPORT bool Move(const FilePath& from_path, const FilePath& to_path);
 // Renames file |from_path| to |to_path|. Both paths must be on the same
 // volume, or the function will fail. Destination file will be created
 // if it doesn't exist. Prefer this function over Move when dealing with
 // temporary files. On Windows it preserves attributes of the target file.
 // Returns true on success, leaving *error unchanged.
 // Returns false on failure and sets *error appropriately, if it is non-NULL.
 BASE_EXPORT bool ReplaceFile(const FilePath& from_path,
                              const FilePath& to_path,
                              PlatformFileError* error);
 // Copies a single file. Use CopyDirectory to copy directories.
 // This function fails if either path contains traversal components ('..').
 BASE_EXPORT bool CopyFile(const FilePath& from_path, const FilePath& to_path);
 // Copies the given path, and optionally all subdirectories and their contents
 // as well.
 //
 // If there are files existing under to_path, always overwrite. Returns true
 // if successful, false otherwise. Wildcards on the names are not supported.
 //
 // If you only need to copy a file use CopyFile, it's faster.
 BASE_EXPORT bool CopyDirectory(const FilePath& from_path,
                                const FilePath& to_path,
                                bool recursive);
 // Returns true if the given path exists on the local filesystem,
 // false otherwise.
 BASE_EXPORT bool PathExists(const FilePath& path);
 // Returns true if the given path is writable by the user, false otherwise.
 BASE_EXPORT bool PathIsWritable(const FilePath& path);
 // Returns true if the given path exists and is a directory, false otherwise.
 BASE_EXPORT bool DirectoryExists(const FilePath& path);
 // Returns true if the contents of the two files given are equal, false
 // otherwise.  If either file can't be read, returns false.
 BASE_EXPORT bool ContentsEqual(const FilePath& filename1,
                                const FilePath& filename2);
 // Returns true if the contents of the two text files given are equal, false
 // otherwise.  This routine treats "\r\n" and "\n" as equivalent.
 BASE_EXPORT bool TextContentsEqual(const FilePath& filename1,
                                    const FilePath& filename2);
 // Read the file at |path| into |contents|, returning true on success.
 // This function fails if the |path| contains path traversal components ('..').
 // |contents| may be NULL, in which case this function is useful for its
 // side effect of priming the disk cache.
 // Useful for unit tests.
 BASE_EXPORT bool ReadFileToString(const FilePath& path, std::string* contents);
 }  // namespace base
 // -----------------------------------------------------------------------------
 namespace file_util {
 #if defined(OS_POSIX)
 // Read exactly |bytes| bytes from file descriptor |fd|, storing the result
 // in |buffer|. This function is protected against EINTR and partial reads.
 // Returns true iff |bytes| bytes have been successfully read from |fd|.
 BASE_EXPORT bool ReadFromFD(int fd, char* buffer, size_t bytes);
 // Creates a symbolic link at |symlink| pointing to |target|.  Returns
 // false on failure.
 BASE_EXPORT bool CreateSymbolicLink(const base::FilePath& target,
                                     const base::FilePath& symlink);
 // Reads the given |symlink| and returns where it points to in |target|.
 // Returns false upon failure.
 BASE_EXPORT bool ReadSymbolicLink(const base::FilePath& symlink,
                                   base::FilePath* target);
 // Bits ans masks of the file permission.
 enum FilePermissionBits {
   FILE_PERMISSION_MASK              = S_IRWXU | S_IRWXG | S_IRWXO,
   FILE_PERMISSION_USER_MASK         = S_IRWXU,
   FILE_PERMISSION_GROUP_MASK        = S_IRWXG,
   FILE_PERMISSION_OTHERS_MASK       = S_IRWXO,
   FILE_PERMISSION_READ_BY_USER      = S_IRUSR,
   FILE_PERMISSION_WRITE_BY_USER     = S_IWUSR,
   FILE_PERMISSION_EXECUTE_BY_USER   = S_IXUSR,
   FILE_PERMISSION_READ_BY_GROUP     = S_IRGRP,
   FILE_PERMISSION_WRITE_BY_GROUP    = S_IWGRP,
   FILE_PERMISSION_EXECUTE_BY_GROUP  = S_IXGRP,
   FILE_PERMISSION_READ_BY_OTHERS    = S_IROTH,
   FILE_PERMISSION_WRITE_BY_OTHERS   = S_IWOTH,
   FILE_PERMISSION_EXECUTE_BY_OTHERS = S_IXOTH,
 };
 // Reads the permission of the given |path|, storing the file permission
 // bits in |mode|. If |path| is symbolic link, |mode| is the permission of
 // a file which the symlink points to.
 BASE_EXPORT bool GetPosixFilePermissions(const base::FilePath& path,
                                          int* mode);
 // Sets the permission of the given |path|. If |path| is symbolic link, sets
 // the permission of a file which the symlink points to.
 BASE_EXPORT bool SetPosixFilePermissions(const base::FilePath& path,
                                          int mode);
 #endif  // defined(OS_POSIX)
 // Return true if the given directory is empty
 BASE_EXPORT bool IsDirectoryEmpty(const base::FilePath& dir_path);
 // Get the temporary directory provided by the system.
 // WARNING: DON'T USE THIS. If you want to create a temporary file, use one of
 // the functions below.
 BASE_EXPORT bool GetTempDir(base::FilePath* path);
 // Get a temporary directory for shared memory files.
 // Only useful on POSIX; redirects to GetTempDir() on Windows.
 BASE_EXPORT bool GetShmemTempDir(base::FilePath* path, bool executable);
 // Get the home directory.  This is more complicated than just getenv("HOME")
 // as it knows to fall back on getpwent() etc.
 BASE_EXPORT base::FilePath GetHomeDir();
 // Creates a temporary file. The full path is placed in |path|, and the
 // function returns true if was successful in creating the file. The file will
 // be empty and all handles closed after this function returns.
 BASE_EXPORT bool CreateTemporaryFile(base::FilePath* path);
 // Same as CreateTemporaryFile but the file is created in |dir|.
 BASE_EXPORT bool CreateTemporaryFileInDir(const base::FilePath& dir,
                                           base::FilePath* temp_file);
 // Create and open a temporary file.  File is opened for read/write.
 // The full path is placed in |path|.
 // Returns a handle to the opened file or NULL if an error occurred.
 BASE_EXPORT FILE* CreateAndOpenTemporaryFile(base::FilePath* path);
 // Like above but for shmem files.  Only useful for POSIX.
 // The executable flag says the file needs to support using
 // mprotect with PROT_EXEC after mapping.
 BASE_EXPORT FILE* CreateAndOpenTemporaryShmemFile(base::FilePath* path,
                                                   bool executable);
 // Similar to CreateAndOpenTemporaryFile, but the file is created in |dir|.
 BASE_EXPORT FILE* CreateAndOpenTemporaryFileInDir(const base::FilePath& dir,
                                                   base::FilePath* path);
 // Create a new directory. If prefix is provided, the new directory name is in
 // the format of prefixyyyy.
 // NOTE: prefix is ignored in the POSIX implementation.
 // If success, return true and output the full path of the directory created.
 BASE_EXPORT bool CreateNewTempDirectory(
     const base::FilePath::StringType& prefix,
     base::FilePath* new_temp_path);
 // Create a directory within another directory.
 // Extra characters will be appended to |prefix| to ensure that the
 // new directory does not have the same name as an existing directory.
 BASE_EXPORT bool CreateTemporaryDirInDir(
     const base::FilePath& base_dir,
     const base::FilePath::StringType& prefix,
     base::FilePath* new_dir);
 // Creates a directory, as well as creating any parent directories, if they
 // don't exist. Returns 'true' on successful creation, or if the directory
 // already exists.  The directory is only readable by the current user.
 // Returns true on success, leaving *error unchanged.
 // Returns false on failure and sets *error appropriately, if it is non-NULL.
 BASE_EXPORT bool CreateDirectoryAndGetError(const base::FilePath& full_path,
                                             base::PlatformFileError* error);
 // Backward-compatible convenience method for the above.
 BASE_EXPORT bool CreateDirectory(const base::FilePath& full_path);
 // Returns the file size. Returns true on success.
 BASE_EXPORT bool GetFileSize(const base::FilePath& file_path, int64* file_size);
 // Sets |real_path| to |path| with symbolic links and junctions expanded.
 // On windows, make sure the path starts with a lettered drive.
 // |path| must reference a file.  Function will fail if |path| points to
 // a directory or to a nonexistent path.  On windows, this function will
 // fail if |path| is a junction or symlink that points to an empty file,
 // or if |real_path| would be longer than MAX_PATH characters.
 BASE_EXPORT bool NormalizeFilePath(const base::FilePath& path,
                                    base::FilePath* real_path);
 #if defined(OS_WIN)
 // Given a path in NT native form ("\Device\HarddiskVolumeXX\..."),
 // return in |drive_letter_path| the equivalent path that starts with
 // a drive letter ("C:\...").  Return false if no such path exists.
 BASE_EXPORT bool DevicePathToDriveLetterPath(const base::FilePath& device_path,
                                              base::FilePath* drive_letter_path);
 // Given an existing file in |path|, set |real_path| to the path
 // in native NT format, of the form "\Device\HarddiskVolumeXX\..".
 // Returns false if the path can not be found. Empty files cannot
 // be resolved with this function.
 BASE_EXPORT bool NormalizeToNativeFilePath(const base::FilePath& path,
                                            base::FilePath* nt_path);
 #endif
 // This function will return if the given file is a symlink or not.
 BASE_EXPORT bool IsLink(const base::FilePath& file_path);
 // Returns information about the given file path.
 BASE_EXPORT bool GetFileInfo(const base::FilePath& file_path,
                              base::PlatformFileInfo* info);
 // Sets the time of the last access and the time of the last modification.
 BASE_EXPORT bool TouchFile(const base::FilePath& path,
                            const base::Time& last_accessed,
                            const base::Time& last_modified);
 // Set the time of the last modification. Useful for unit tests.
 BASE_EXPORT bool SetLastModifiedTime(const base::FilePath& path,
                                      const base::Time& last_modified);
 #if defined(OS_POSIX)
 // Store inode number of |path| in |inode|. Return true on success.
 BASE_EXPORT bool GetInode(const base::FilePath& path, ino_t* inode);
 #endif
 // Wrapper for fopen-like calls. Returns non-NULL FILE* on success.
 BASE_EXPORT FILE* OpenFile(const base::FilePath& filename, const char* mode);
 // Closes file opened by OpenFile. Returns true on success.
 BASE_EXPORT bool CloseFile(FILE* file);
 // Truncates an open file to end at the location of the current file pointer.
 // This is a cross-platform analog to Windows' SetEndOfFile() function.
 BASE_EXPORT bool TruncateFile(FILE* file);
 // Reads the given number of bytes from the file into the buffer.  Returns
 // the number of read bytes, or -1 on error.
 BASE_EXPORT int ReadFile(const base::FilePath& filename, char* data, int size);
 // Writes the given buffer into the file, overwriting any data that was
 // previously there.  Returns the number of bytes written, or -1 on error.
 BASE_EXPORT int WriteFile(const base::FilePath& filename, const char* data,
                           int size);
 #if defined(OS_POSIX)
 // Append the data to |fd|. Does not close |fd| when done.
 BASE_EXPORT int WriteFileDescriptor(const int fd, const char* data, int size);
 #endif
 // Append the given buffer into the file. Returns the number of bytes written,
 // or -1 on error.
 BASE_EXPORT int AppendToFile(const base::FilePath& filename,
                              const char* data, int size);
 // Gets the current working directory for the process.
 BASE_EXPORT bool GetCurrentDirectory(base::FilePath* path);
 // Sets the current working directory for the process.
 BASE_EXPORT bool SetCurrentDirectory(const base::FilePath& path);
 // Attempts to find a number that can be appended to the |path| to make it
 // unique. If |path| does not exist, 0 is returned.  If it fails to find such
 // a number, -1 is returned. If |suffix| is not empty, also checks the
 // existence of it with the given suffix.
 BASE_EXPORT int GetUniquePathNumber(const base::FilePath& path,
                                     const base::FilePath::StringType& suffix);
 #if defined(OS_POSIX)
 // Creates a directory with a guaranteed unique name based on |path|, returning
 // the pathname if successful, or an empty path if there was an error creating
 // the directory. Does not create parent directories.
 BASE_EXPORT base::FilePath MakeUniqueDirectory(const base::FilePath& path);
 #endif
 #if defined(OS_POSIX)
 // Test that |path| can only be changed by a given user and members of
 // a given set of groups.
 // Specifically, test that all parts of |path| under (and including) |base|:
 // * Exist.
 // * Are owned by a specific user.
 // * Are not writable by all users.
 // * Are owned by a member of a given set of groups, or are not writable by
 //   their group.
 // * Are not symbolic links.
 // This is useful for checking that a config file is administrator-controlled.
 // |base| must contain |path|.
 BASE_EXPORT bool VerifyPathControlledByUser(const base::FilePath& base,
                                             const base::FilePath& path,
                                             uid_t owner_uid,
                                             const std::set<gid_t>& group_gids);
 #endif  // defined(OS_POSIX)
 #if defined(OS_MACOSX) && !defined(OS_IOS)
 // Is |path| writable only by a user with administrator privileges?
 // This function uses Mac OS conventions.  The super user is assumed to have
 // uid 0, and the administrator group is assumed to be named "admin".
 // Testing that |path|, and every parent directory including the root of
 // the filesystem, are owned by the superuser, controlled by the group
 // "admin", are not writable by all users, and contain no symbolic links.
 // Will return false if |path| does not exist.
 BASE_EXPORT bool VerifyPathControlledByAdmin(const base::FilePath& path);
 #endif  // defined(OS_MACOSX) && !defined(OS_IOS)
 // Returns the maximum length of path component on the volume containing
 // the directory |path|, in the number of FilePath::CharType, or -1 on failure.
 BASE_EXPORT int GetMaximumPathComponentLength(const base::FilePath& path);
 // A class to handle auto-closing of FILE*'s.
 class ScopedFILEClose {
  public:
   inline void operator()(FILE* x) const {
     if (x) {
       fclose(x);
     }
   }
 };
 typedef scoped_ptr_malloc<FILE, ScopedFILEClose> ScopedFILE;
 #if defined(OS_POSIX)
 // A class to handle auto-closing of FDs.
 class ScopedFDClose {
  public:
   inline void operator()(int* x) const {
     if (x && *x >= 0) {
       if (HANDLE_EINTR(close(*x)) < 0)
         DPLOG(ERROR) << "close";
     }
   }
 };
 typedef scoped_ptr_malloc<int, ScopedFDClose> ScopedFD;
 #endif  // OS_POSIX
 #if defined(OS_LINUX)
 // Broad categories of file systems as returned by statfs() on Linux.
 enum FileSystemType {
   FILE_SYSTEM_UNKNOWN,  // statfs failed.
   FILE_SYSTEM_0,        // statfs.f_type == 0 means unknown, may indicate AFS.
   FILE_SYSTEM_ORDINARY,       // on-disk filesystem like ext2
   FILE_SYSTEM_NFS,
   FILE_SYSTEM_SMB,
   FILE_SYSTEM_CODA,
   FILE_SYSTEM_MEMORY,         // in-memory file system
   FILE_SYSTEM_CGROUP,         // cgroup control.
   FILE_SYSTEM_OTHER,          // any other value.
   FILE_SYSTEM_TYPE_COUNT
 };
 // Attempts determine the FileSystemType for |path|.
 // Returns false if |path| doesn't exist.
 BASE_EXPORT bool GetFileSystemType(const base::FilePath& path,
                                    FileSystemType* type);
 #endif
 }  // namespace file_util
 // Internal --------------------------------------------------------------------
 namespace base {
 namespace internal {
 // Same as Move but allows paths with traversal components.
 // Use only with extreme care.
 BASE_EXPORT bool MoveUnsafe(const FilePath& from_path,
                             const FilePath& to_path);
 // Same as CopyFile but allows paths with traversal components.
 // Use only with extreme care.
 BASE_EXPORT bool CopyFileUnsafe(const FilePath& from_path,
                                 const FilePath& to_path);
 #if defined(OS_WIN)
 // Copy from_path to to_path recursively and then delete from_path recursively.
 // Returns true if all operations succeed.
 // This function simulates Move(), but unlike Move() it works across volumes.
 // This function is not transactional.
 BASE_EXPORT bool CopyAndDeleteDirectory(const FilePath& from_path,
                                         const FilePath& to_path);
 #endif  // defined(OS_WIN)
 }  // namespace internal
 }  // namespace base
 #endif  // BASE_FILE_UTIL_H_

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security/sandbox/chromium/base/file_util.h@141e0f1194b1 (annotated)

security/sandbox/chromium/base/file_util.h