blob: ddcd5ddb91216dfc47a1c0c9ef3eded635356445 [file] [log] [blame]
// 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.
#include "base/file_util.h"
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <libgen.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/errno.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
#if defined(OS_MACOSX)
#include <AvailabilityMacros.h>
#include "base/mac/foundation_util.h"
#elif !defined(OS_CHROMEOS) && defined(USE_GLIB)
#include <glib.h> // for g_get_home_dir()
#endif
#include <fstream>
#include "base/basictypes.h"
#include "base/files/file_enumerator.h"
#include "base/files/file_path.h"
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/singleton.h"
#include "base/path_service.h"
#include "base/posix/eintr_wrapper.h"
#include "base/stl_util.h"
#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
#include "base/strings/sys_string_conversions.h"
#include "base/strings/utf_string_conversions.h"
#include "base/sys_info.h"
#include "base/threading/thread_restrictions.h"
#include "base/time/time.h"
#if defined(OS_ANDROID)
#include "base/android/content_uri_utils.h"
#include "base/os_compat_android.h"
#endif
#if !defined(OS_IOS)
#include <grp.h>
#endif
namespace base {
namespace {
#if defined(OS_BSD) || defined(OS_MACOSX)
typedef struct stat stat_wrapper_t;
static int CallStat(const char *path, stat_wrapper_t *sb) {
ThreadRestrictions::AssertIOAllowed();
return stat(path, sb);
}
static int CallLstat(const char *path, stat_wrapper_t *sb) {
ThreadRestrictions::AssertIOAllowed();
return lstat(path, sb);
}
#else
typedef struct stat64 stat_wrapper_t;
static int CallStat(const char *path, stat_wrapper_t *sb) {
ThreadRestrictions::AssertIOAllowed();
return stat64(path, sb);
}
static int CallLstat(const char *path, stat_wrapper_t *sb) {
ThreadRestrictions::AssertIOAllowed();
return lstat64(path, sb);
}
#if defined(OS_ANDROID)
static int CallFstat(int fd, stat_wrapper_t *sb) {
ThreadRestrictions::AssertIOAllowed();
return fstat64(fd, sb);
}
#endif
#endif
// Helper for NormalizeFilePath(), defined below.
bool RealPath(const FilePath& path, FilePath* real_path) {
ThreadRestrictions::AssertIOAllowed(); // For realpath().
FilePath::CharType buf[PATH_MAX];
if (!realpath(path.value().c_str(), buf))
return false;
*real_path = FilePath(buf);
return true;
}
// Helper for VerifyPathControlledByUser.
bool VerifySpecificPathControlledByUser(const FilePath& path,
uid_t owner_uid,
const std::set<gid_t>& group_gids) {
stat_wrapper_t stat_info;
if (CallLstat(path.value().c_str(), &stat_info) != 0) {
DPLOG(ERROR) << "Failed to get information on path "
<< path.value();
return false;
}
if (S_ISLNK(stat_info.st_mode)) {
DLOG(ERROR) << "Path " << path.value()
<< " is a symbolic link.";
return false;
}
if (stat_info.st_uid != owner_uid) {
DLOG(ERROR) << "Path " << path.value()
<< " is owned by the wrong user.";
return false;
}
if ((stat_info.st_mode & S_IWGRP) &&
!ContainsKey(group_gids, stat_info.st_gid)) {
DLOG(ERROR) << "Path " << path.value()
<< " is writable by an unprivileged group.";
return false;
}
if (stat_info.st_mode & S_IWOTH) {
DLOG(ERROR) << "Path " << path.value()
<< " is writable by any user.";
return false;
}
return true;
}
std::string TempFileName() {
#if defined(OS_MACOSX)
return StringPrintf(".%s.XXXXXX", base::mac::BaseBundleID());
#endif
#if defined(GOOGLE_CHROME_BUILD)
return std::string(".com.google.Chrome.XXXXXX");
#else
return std::string(".org.chromium.Chromium.XXXXXX");
#endif
}
// Creates and opens a temporary file in |directory|, returning the
// file descriptor. |path| is set to the temporary file path.
// This function does NOT unlink() the file.
int CreateAndOpenFdForTemporaryFile(FilePath directory, FilePath* path) {
ThreadRestrictions::AssertIOAllowed(); // For call to mkstemp().
*path = directory.Append(base::TempFileName());
const std::string& tmpdir_string = path->value();
// this should be OK since mkstemp just replaces characters in place
char* buffer = const_cast<char*>(tmpdir_string.c_str());
return HANDLE_EINTR(mkstemp(buffer));
}
#if defined(OS_LINUX)
// Determine if /dev/shm files can be mapped and then mprotect'd PROT_EXEC.
// This depends on the mount options used for /dev/shm, which vary among
// different Linux distributions and possibly local configuration. It also
// depends on details of kernel--ChromeOS uses the noexec option for /dev/shm
// but its kernel allows mprotect with PROT_EXEC anyway.
bool DetermineDevShmExecutable() {
bool result = false;
FilePath path;
int fd = CreateAndOpenFdForTemporaryFile(FilePath("/dev/shm"), &path);
if (fd >= 0) {
file_util::ScopedFD shm_fd_closer(&fd);
DeleteFile(path, false);
long sysconf_result = sysconf(_SC_PAGESIZE);
CHECK_GE(sysconf_result, 0);
size_t pagesize = static_cast<size_t>(sysconf_result);
CHECK_GE(sizeof(pagesize), sizeof(sysconf_result));
void *mapping = mmap(NULL, pagesize, PROT_READ, MAP_SHARED, fd, 0);
if (mapping != MAP_FAILED) {
if (mprotect(mapping, pagesize, PROT_READ | PROT_EXEC) == 0)
result = true;
munmap(mapping, pagesize);
}
}
return result;
}
#endif // defined(OS_LINUX)
} // namespace
FilePath MakeAbsoluteFilePath(const FilePath& input) {
ThreadRestrictions::AssertIOAllowed();
char full_path[PATH_MAX];
if (realpath(input.value().c_str(), full_path) == NULL)
return FilePath();
return FilePath(full_path);
}
// TODO(erikkay): The Windows version of this accepts paths like "foo/bar/*"
// which works both with and without the recursive flag. I'm not sure we need
// that functionality. If not, remove from file_util_win.cc, otherwise add it
// here.
bool DeleteFile(const FilePath& path, bool recursive) {
ThreadRestrictions::AssertIOAllowed();
const char* path_str = path.value().c_str();
stat_wrapper_t file_info;
int test = CallLstat(path_str, &file_info);
if (test != 0) {
// The Windows version defines this condition as success.
bool ret = (errno == ENOENT || errno == ENOTDIR);
return ret;
}
if (!S_ISDIR(file_info.st_mode))
return (unlink(path_str) == 0);
if (!recursive)
return (rmdir(path_str) == 0);
bool success = true;
std::stack<std::string> directories;
directories.push(path.value());
FileEnumerator traversal(path, true,
FileEnumerator::FILES | FileEnumerator::DIRECTORIES |
FileEnumerator::SHOW_SYM_LINKS);
for (FilePath current = traversal.Next(); success && !current.empty();
current = traversal.Next()) {
if (traversal.GetInfo().IsDirectory())
directories.push(current.value());
else
success = (unlink(current.value().c_str()) == 0);
}
while (success && !directories.empty()) {
FilePath dir = FilePath(directories.top());
directories.pop();
success = (rmdir(dir.value().c_str()) == 0);
}
return success;
}
bool ReplaceFile(const FilePath& from_path,
const FilePath& to_path,
PlatformFileError* error) {
ThreadRestrictions::AssertIOAllowed();
if (rename(from_path.value().c_str(), to_path.value().c_str()) == 0)
return true;
if (error)
*error = ErrnoToPlatformFileError(errno);
return false;
}
bool CopyDirectory(const FilePath& from_path,
const FilePath& to_path,
bool recursive) {
ThreadRestrictions::AssertIOAllowed();
// Some old callers of CopyDirectory want it to support wildcards.
// After some discussion, we decided to fix those callers.
// Break loudly here if anyone tries to do this.
// TODO(evanm): remove this once we're sure it's ok.
DCHECK(to_path.value().find('*') == std::string::npos);
DCHECK(from_path.value().find('*') == std::string::npos);
char top_dir[PATH_MAX];
if (strlcpy(top_dir, from_path.value().c_str(),
arraysize(top_dir)) >= arraysize(top_dir)) {
return false;
}
// This function does not properly handle destinations within the source
FilePath real_to_path = to_path;
if (PathExists(real_to_path)) {
real_to_path = MakeAbsoluteFilePath(real_to_path);
if (real_to_path.empty())
return false;
} else {
real_to_path = MakeAbsoluteFilePath(real_to_path.DirName());
if (real_to_path.empty())
return false;
}
FilePath real_from_path = MakeAbsoluteFilePath(from_path);
if (real_from_path.empty())
return false;
if (real_to_path.value().size() >= real_from_path.value().size() &&
real_to_path.value().compare(0, real_from_path.value().size(),
real_from_path.value()) == 0)
return false;
bool success = true;
int traverse_type = FileEnumerator::FILES | FileEnumerator::SHOW_SYM_LINKS;
if (recursive)
traverse_type |= FileEnumerator::DIRECTORIES;
FileEnumerator traversal(from_path, recursive, traverse_type);
// We have to mimic windows behavior here. |to_path| may not exist yet,
// start the loop with |to_path|.
struct stat from_stat;
FilePath current = from_path;
if (stat(from_path.value().c_str(), &from_stat) < 0) {
DLOG(ERROR) << "CopyDirectory() couldn't stat source directory: "
<< from_path.value() << " errno = " << errno;
success = false;
}
struct stat to_path_stat;
FilePath from_path_base = from_path;
if (recursive && stat(to_path.value().c_str(), &to_path_stat) == 0 &&
S_ISDIR(to_path_stat.st_mode)) {
// If the destination already exists and is a directory, then the
// top level of source needs to be copied.
from_path_base = from_path.DirName();
}
// The Windows version of this function assumes that non-recursive calls
// will always have a directory for from_path.
DCHECK(recursive || S_ISDIR(from_stat.st_mode));
while (success && !current.empty()) {
// current is the source path, including from_path, so append
// the suffix after from_path to to_path to create the target_path.
FilePath target_path(to_path);
if (from_path_base != current) {
if (!from_path_base.AppendRelativePath(current, &target_path)) {
success = false;
break;
}
}
if (S_ISDIR(from_stat.st_mode)) {
if (mkdir(target_path.value().c_str(), from_stat.st_mode & 01777) != 0 &&
errno != EEXIST) {
DLOG(ERROR) << "CopyDirectory() couldn't create directory: "
<< target_path.value() << " errno = " << errno;
success = false;
}
} else if (S_ISREG(from_stat.st_mode)) {
if (!CopyFile(current, target_path)) {
DLOG(ERROR) << "CopyDirectory() couldn't create file: "
<< target_path.value();
success = false;
}
} else {
DLOG(WARNING) << "CopyDirectory() skipping non-regular file: "
<< current.value();
}
current = traversal.Next();
if (!current.empty())
from_stat = traversal.GetInfo().stat();
}
return success;
}
bool PathExists(const FilePath& path) {
ThreadRestrictions::AssertIOAllowed();
#if defined(OS_ANDROID)
if (path.IsContentUri()) {
return ContentUriExists(path);
}
#endif
return access(path.value().c_str(), F_OK) == 0;
}
bool PathIsWritable(const FilePath& path) {
ThreadRestrictions::AssertIOAllowed();
return access(path.value().c_str(), W_OK) == 0;
}
bool DirectoryExists(const FilePath& path) {
ThreadRestrictions::AssertIOAllowed();
stat_wrapper_t file_info;
if (CallStat(path.value().c_str(), &file_info) == 0)
return S_ISDIR(file_info.st_mode);
return false;
}
bool ReadFromFD(int fd, char* buffer, size_t bytes) {
size_t total_read = 0;
while (total_read < bytes) {
ssize_t bytes_read =
HANDLE_EINTR(read(fd, buffer + total_read, bytes - total_read));
if (bytes_read <= 0)
break;
total_read += bytes_read;
}
return total_read == bytes;
}
bool CreateSymbolicLink(const FilePath& target_path,
const FilePath& symlink_path) {
DCHECK(!symlink_path.empty());
DCHECK(!target_path.empty());
return ::symlink(target_path.value().c_str(),
symlink_path.value().c_str()) != -1;
}
bool ReadSymbolicLink(const FilePath& symlink_path, FilePath* target_path) {
DCHECK(!symlink_path.empty());
DCHECK(target_path);
char buf[PATH_MAX];
ssize_t count = ::readlink(symlink_path.value().c_str(), buf, arraysize(buf));
if (count <= 0) {
target_path->clear();
return false;
}
*target_path = FilePath(FilePath::StringType(buf, count));
return true;
}
bool GetPosixFilePermissions(const FilePath& path, int* mode) {
ThreadRestrictions::AssertIOAllowed();
DCHECK(mode);
stat_wrapper_t file_info;
// Uses stat(), because on symbolic link, lstat() does not return valid
// permission bits in st_mode
if (CallStat(path.value().c_str(), &file_info) != 0)
return false;
*mode = file_info.st_mode & FILE_PERMISSION_MASK;
return true;
}
bool SetPosixFilePermissions(const FilePath& path,
int mode) {
ThreadRestrictions::AssertIOAllowed();
DCHECK((mode & ~FILE_PERMISSION_MASK) == 0);
// Calls stat() so that we can preserve the higher bits like S_ISGID.
stat_wrapper_t stat_buf;
if (CallStat(path.value().c_str(), &stat_buf) != 0)
return false;
// Clears the existing permission bits, and adds the new ones.
mode_t updated_mode_bits = stat_buf.st_mode & ~FILE_PERMISSION_MASK;
updated_mode_bits |= mode & FILE_PERMISSION_MASK;
if (HANDLE_EINTR(chmod(path.value().c_str(), updated_mode_bits)) != 0)
return false;
return true;
}
#if !defined(OS_MACOSX)
// This is implemented in file_util_mac.mm for Mac.
bool GetTempDir(FilePath* path) {
const char* tmp = getenv("TMPDIR");
if (tmp) {
*path = FilePath(tmp);
} else {
#if defined(OS_ANDROID)
return PathService::Get(base::DIR_CACHE, path);
#else
*path = FilePath("/tmp");
#endif
}
return true;
}
#endif // !defined(OS_MACOSX)
#if !defined(OS_MACOSX) && !defined(OS_ANDROID)
// This is implemented in file_util_mac.mm and file_util_android.cc for those
// platforms.
bool GetShmemTempDir(bool executable, FilePath* path) {
#if defined(OS_LINUX)
bool use_dev_shm = true;
if (executable) {
static const bool s_dev_shm_executable = DetermineDevShmExecutable();
use_dev_shm = s_dev_shm_executable;
}
if (use_dev_shm) {
*path = FilePath("/dev/shm");
return true;
}
#endif
return GetTempDir(path);
}
#endif // !defined(OS_MACOSX) && !defined(OS_ANDROID)
#if !defined(OS_MACOSX)
FilePath GetHomeDir() {
#if defined(OS_CHROMEOS)
if (SysInfo::IsRunningOnChromeOS())
return FilePath("/home/chronos/user");
#endif
const char* home_dir = getenv("HOME");
if (home_dir && home_dir[0])
return FilePath(home_dir);
#if defined(OS_ANDROID)
DLOG(WARNING) << "OS_ANDROID: Home directory lookup not yet implemented.";
#elif defined(USE_GLIB) && !defined(OS_CHROMEOS)
// g_get_home_dir calls getpwent, which can fall through to LDAP calls.
ThreadRestrictions::AssertIOAllowed();
home_dir = g_get_home_dir();
if (home_dir && home_dir[0])
return FilePath(home_dir);
#endif
FilePath rv;
if (GetTempDir(&rv))
return rv;
// Last resort.
return FilePath("/tmp");
}
#endif // !defined(OS_MACOSX)
bool CreateTemporaryFile(FilePath* path) {
ThreadRestrictions::AssertIOAllowed(); // For call to close().
FilePath directory;
if (!GetTempDir(&directory))
return false;
int fd = CreateAndOpenFdForTemporaryFile(directory, path);
if (fd < 0)
return false;
close(fd);
return true;
}
FILE* CreateAndOpenTemporaryShmemFile(FilePath* path, bool executable) {
FilePath directory;
if (!GetShmemTempDir(executable, &directory))
return NULL;
return CreateAndOpenTemporaryFileInDir(directory, path);
}
FILE* CreateAndOpenTemporaryFileInDir(const FilePath& dir, FilePath* path) {
int fd = CreateAndOpenFdForTemporaryFile(dir, path);
if (fd < 0)
return NULL;
FILE* file = fdopen(fd, "a+");
if (!file)
close(fd);
return file;
}
bool CreateTemporaryFileInDir(const FilePath& dir, FilePath* temp_file) {
ThreadRestrictions::AssertIOAllowed(); // For call to close().
int fd = CreateAndOpenFdForTemporaryFile(dir, temp_file);
return ((fd >= 0) && !IGNORE_EINTR(close(fd)));
}
static bool CreateTemporaryDirInDirImpl(const FilePath& base_dir,
const FilePath::StringType& name_tmpl,
FilePath* new_dir) {
ThreadRestrictions::AssertIOAllowed(); // For call to mkdtemp().
DCHECK(name_tmpl.find("XXXXXX") != FilePath::StringType::npos)
<< "Directory name template must contain \"XXXXXX\".";
FilePath sub_dir = base_dir.Append(name_tmpl);
std::string sub_dir_string = sub_dir.value();
// this should be OK since mkdtemp just replaces characters in place
char* buffer = const_cast<char*>(sub_dir_string.c_str());
char* dtemp = mkdtemp(buffer);
if (!dtemp) {
DPLOG(ERROR) << "mkdtemp";
return false;
}
*new_dir = FilePath(dtemp);
return true;
}
bool CreateTemporaryDirInDir(const FilePath& base_dir,
const FilePath::StringType& prefix,
FilePath* new_dir) {
FilePath::StringType mkdtemp_template = prefix;
mkdtemp_template.append(FILE_PATH_LITERAL("XXXXXX"));
return CreateTemporaryDirInDirImpl(base_dir, mkdtemp_template, new_dir);
}
bool CreateNewTempDirectory(const FilePath::StringType& prefix,
FilePath* new_temp_path) {
FilePath tmpdir;
if (!GetTempDir(&tmpdir))
return false;
return CreateTemporaryDirInDirImpl(tmpdir, TempFileName(), new_temp_path);
}
bool CreateDirectoryAndGetError(const FilePath& full_path,
PlatformFileError* error) {
ThreadRestrictions::AssertIOAllowed(); // For call to mkdir().
std::vector<FilePath> subpaths;
// Collect a list of all parent directories.
FilePath last_path = full_path;
subpaths.push_back(full_path);
for (FilePath path = full_path.DirName();
path.value() != last_path.value(); path = path.DirName()) {
subpaths.push_back(path);
last_path = path;
}
// Iterate through the parents and create the missing ones.
for (std::vector<FilePath>::reverse_iterator i = subpaths.rbegin();
i != subpaths.rend(); ++i) {
if (DirectoryExists(*i))
continue;
if (mkdir(i->value().c_str(), 0700) == 0)
continue;
// Mkdir failed, but it might have failed with EEXIST, or some other error
// due to the the directory appearing out of thin air. This can occur if
// two processes are trying to create the same file system tree at the same
// time. Check to see if it exists and make sure it is a directory.
int saved_errno = errno;
if (!DirectoryExists(*i)) {
if (error)
*error = ErrnoToPlatformFileError(saved_errno);
return false;
}
}
return true;
}
bool NormalizeFilePath(const FilePath& path, FilePath* normalized_path) {
FilePath real_path_result;
if (!RealPath(path, &real_path_result))
return false;
// To be consistant with windows, fail if |real_path_result| is a
// directory.
stat_wrapper_t file_info;
if (CallStat(real_path_result.value().c_str(), &file_info) != 0 ||
S_ISDIR(file_info.st_mode))
return false;
*normalized_path = real_path_result;
return true;
}
// TODO(rkc): Refactor GetFileInfo and FileEnumerator to handle symlinks
// correctly. http://code.google.com/p/chromium-os/issues/detail?id=15948
bool IsLink(const FilePath& file_path) {
stat_wrapper_t st;
// If we can't lstat the file, it's safe to assume that the file won't at
// least be a 'followable' link.
if (CallLstat(file_path.value().c_str(), &st) != 0)
return false;
if (S_ISLNK(st.st_mode))
return true;
else
return false;
}
bool GetFileInfo(const FilePath& file_path, PlatformFileInfo* results) {
stat_wrapper_t file_info;
#if defined(OS_ANDROID)
if (file_path.IsContentUri()) {
int fd = OpenContentUriForRead(file_path);
if (fd < 0)
return false;
file_util::ScopedFD scoped_fd(&fd);
if (CallFstat(fd, &file_info) != 0)
return false;
} else {
#endif // defined(OS_ANDROID)
if (CallStat(file_path.value().c_str(), &file_info) != 0)
return false;
#if defined(OS_ANDROID)
}
#endif // defined(OS_ANDROID)
results->is_directory = S_ISDIR(file_info.st_mode);
results->size = file_info.st_size;
#if defined(OS_MACOSX)
results->last_modified = Time::FromTimeSpec(file_info.st_mtimespec);
results->last_accessed = Time::FromTimeSpec(file_info.st_atimespec);
results->creation_time = Time::FromTimeSpec(file_info.st_ctimespec);
#elif defined(OS_ANDROID)
results->last_modified = Time::FromTimeT(file_info.st_mtime);
results->last_accessed = Time::FromTimeT(file_info.st_atime);
results->creation_time = Time::FromTimeT(file_info.st_ctime);
#else
results->last_modified = Time::FromTimeSpec(file_info.st_mtim);
results->last_accessed = Time::FromTimeSpec(file_info.st_atim);
results->creation_time = Time::FromTimeSpec(file_info.st_ctim);
#endif
return true;
}
FILE* OpenFile(const FilePath& filename, const char* mode) {
ThreadRestrictions::AssertIOAllowed();
FILE* result = NULL;
do {
result = fopen(filename.value().c_str(), mode);
} while (!result && errno == EINTR);
return result;
}
int ReadFile(const FilePath& filename, char* data, int size) {
ThreadRestrictions::AssertIOAllowed();
int fd = HANDLE_EINTR(open(filename.value().c_str(), O_RDONLY));
if (fd < 0)
return -1;
ssize_t bytes_read = HANDLE_EINTR(read(fd, data, size));
if (int ret = IGNORE_EINTR(close(fd)) < 0)
return ret;
return bytes_read;
}
} // namespace base
// -----------------------------------------------------------------------------
namespace file_util {
using base::stat_wrapper_t;
using base::CallStat;
using base::CallLstat;
using base::CreateAndOpenFdForTemporaryFile;
using base::DirectoryExists;
using base::FileEnumerator;
using base::FilePath;
using base::MakeAbsoluteFilePath;
using base::VerifySpecificPathControlledByUser;
base::FilePath MakeUniqueDirectory(const base::FilePath& path) {
const int kMaxAttempts = 20;
for (int attempts = 0; attempts < kMaxAttempts; attempts++) {
int uniquifier =
GetUniquePathNumber(path, base::FilePath::StringType());
if (uniquifier < 0)
break;
base::FilePath test_path = (uniquifier == 0) ? path :
path.InsertBeforeExtensionASCII(
base::StringPrintf(" (%d)", uniquifier));
if (mkdir(test_path.value().c_str(), 0777) == 0)
return test_path;
else if (errno != EEXIST)
break;
}
return base::FilePath();
}
FILE* OpenFile(const std::string& filename, const char* mode) {
return OpenFile(FilePath(filename), mode);
}
int WriteFile(const FilePath& filename, const char* data, int size) {
base::ThreadRestrictions::AssertIOAllowed();
int fd = HANDLE_EINTR(creat(filename.value().c_str(), 0666));
if (fd < 0)
return -1;
int bytes_written = WriteFileDescriptor(fd, data, size);
if (int ret = IGNORE_EINTR(close(fd)) < 0)
return ret;
return bytes_written;
}
int WriteFileDescriptor(const int fd, const char* data, int size) {
// Allow for partial writes.
ssize_t bytes_written_total = 0;
for (ssize_t bytes_written_partial = 0; bytes_written_total < size;
bytes_written_total += bytes_written_partial) {
bytes_written_partial =
HANDLE_EINTR(write(fd, data + bytes_written_total,
size - bytes_written_total));
if (bytes_written_partial < 0)
return -1;
}
return bytes_written_total;
}
int AppendToFile(const FilePath& filename, const char* data, int size) {
base::ThreadRestrictions::AssertIOAllowed();
int fd = HANDLE_EINTR(open(filename.value().c_str(), O_WRONLY | O_APPEND));
if (fd < 0)
return -1;
int bytes_written = WriteFileDescriptor(fd, data, size);
if (int ret = IGNORE_EINTR(close(fd)) < 0)
return ret;
return bytes_written;
}
// Gets the current working directory for the process.
bool GetCurrentDirectory(FilePath* dir) {
// getcwd can return ENOENT, which implies it checks against the disk.
base::ThreadRestrictions::AssertIOAllowed();
char system_buffer[PATH_MAX] = "";
if (!getcwd(system_buffer, sizeof(system_buffer))) {
NOTREACHED();
return false;
}
*dir = FilePath(system_buffer);
return true;
}
// Sets the current working directory for the process.
bool SetCurrentDirectory(const FilePath& path) {
base::ThreadRestrictions::AssertIOAllowed();
int ret = chdir(path.value().c_str());
return !ret;
}
bool VerifyPathControlledByUser(const FilePath& base,
const FilePath& path,
uid_t owner_uid,
const std::set<gid_t>& group_gids) {
if (base != path && !base.IsParent(path)) {
DLOG(ERROR) << "|base| must be a subdirectory of |path|. base = \""
<< base.value() << "\", path = \"" << path.value() << "\"";
return false;
}
std::vector<FilePath::StringType> base_components;
std::vector<FilePath::StringType> path_components;
base.GetComponents(&base_components);
path.GetComponents(&path_components);
std::vector<FilePath::StringType>::const_iterator ib, ip;
for (ib = base_components.begin(), ip = path_components.begin();
ib != base_components.end(); ++ib, ++ip) {
// |base| must be a subpath of |path|, so all components should match.
// If these CHECKs fail, look at the test that base is a parent of
// path at the top of this function.
DCHECK(ip != path_components.end());
DCHECK(*ip == *ib);
}
FilePath current_path = base;
if (!VerifySpecificPathControlledByUser(current_path, owner_uid, group_gids))
return false;
for (; ip != path_components.end(); ++ip) {
current_path = current_path.Append(*ip);
if (!VerifySpecificPathControlledByUser(
current_path, owner_uid, group_gids))
return false;
}
return true;
}
#if defined(OS_MACOSX) && !defined(OS_IOS)
bool VerifyPathControlledByAdmin(const FilePath& path) {
const unsigned kRootUid = 0;
const FilePath kFileSystemRoot("/");
// The name of the administrator group on mac os.
const char* const kAdminGroupNames[] = {
"admin",
"wheel"
};
// Reading the groups database may touch the file system.
base::ThreadRestrictions::AssertIOAllowed();
std::set<gid_t> allowed_group_ids;
for (int i = 0, ie = arraysize(kAdminGroupNames); i < ie; ++i) {
struct group *group_record = getgrnam(kAdminGroupNames[i]);
if (!group_record) {
DPLOG(ERROR) << "Could not get the group ID of group \""
<< kAdminGroupNames[i] << "\".";
continue;
}
allowed_group_ids.insert(group_record->gr_gid);
}
return VerifyPathControlledByUser(
kFileSystemRoot, path, kRootUid, allowed_group_ids);
}
#endif // defined(OS_MACOSX) && !defined(OS_IOS)
int GetMaximumPathComponentLength(const FilePath& path) {
base::ThreadRestrictions::AssertIOAllowed();
return pathconf(path.value().c_str(), _PC_NAME_MAX);
}
} // namespace file_util
namespace base {
namespace internal {
bool MoveUnsafe(const FilePath& from_path, const FilePath& to_path) {
ThreadRestrictions::AssertIOAllowed();
// Windows compatibility: if to_path exists, from_path and to_path
// must be the same type, either both files, or both directories.
stat_wrapper_t to_file_info;
if (CallStat(to_path.value().c_str(), &to_file_info) == 0) {
stat_wrapper_t from_file_info;
if (CallStat(from_path.value().c_str(), &from_file_info) == 0) {
if (S_ISDIR(to_file_info.st_mode) != S_ISDIR(from_file_info.st_mode))
return false;
} else {
return false;
}
}
if (rename(from_path.value().c_str(), to_path.value().c_str()) == 0)
return true;
if (!CopyDirectory(from_path, to_path, true))
return false;
DeleteFile(from_path, true);
return true;
}
#if !defined(OS_MACOSX)
// Mac has its own implementation, this is for all other Posix systems.
bool CopyFileUnsafe(const FilePath& from_path, const FilePath& to_path) {
ThreadRestrictions::AssertIOAllowed();
int infile = HANDLE_EINTR(open(from_path.value().c_str(), O_RDONLY));
if (infile < 0)
return false;
int outfile = HANDLE_EINTR(creat(to_path.value().c_str(), 0666));
if (outfile < 0) {
close(infile);
return false;
}
const size_t kBufferSize = 32768;
std::vector<char> buffer(kBufferSize);
bool result = true;
while (result) {
ssize_t bytes_read = HANDLE_EINTR(read(infile, &buffer[0], buffer.size()));
if (bytes_read < 0) {
result = false;
break;
}
if (bytes_read == 0)
break;
// Allow for partial writes
ssize_t bytes_written_per_read = 0;
do {
ssize_t bytes_written_partial = HANDLE_EINTR(write(
outfile,
&buffer[bytes_written_per_read],
bytes_read - bytes_written_per_read));
if (bytes_written_partial < 0) {
result = false;
break;
}
bytes_written_per_read += bytes_written_partial;
} while (bytes_written_per_read < bytes_read);
}
if (IGNORE_EINTR(close(infile)) < 0)
result = false;
if (IGNORE_EINTR(close(outfile)) < 0)
result = false;
return result;
}
#endif // !defined(OS_MACOSX)
} // namespace internal
} // namespace base