blob: d2eb4531d8ea82fdb18729cd907f532ec2a69c10 [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/files/file_util.h"
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <libgen.h>
#include <limits.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.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>
#include "base/base_switches.h"
#include "base/command_line.h"
#include "base/containers/stack.h"
#include "base/environment.h"
#include "base/files/file_enumerator.h"
#include "base/files/file_path.h"
#include "base/files/scoped_file.h"
#include "base/logging.h"
#include "base/macros.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_split.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"
#include "build/build_config.h"
#if defined(OS_MACOSX)
#include <AvailabilityMacros.h>
#include "base/mac/foundation_util.h"
#endif
#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
// We need to do this on AIX due to some inconsistencies in how AIX
// handles XOPEN_SOURCE and ALL_SOURCE.
#if defined(OS_AIX)
extern "C" char* mkdtemp(char* path);
#endif
namespace base {
namespace {
#if defined(OS_BSD) || defined(OS_MACOSX) || defined(OS_NACL) || \
defined(OS_ANDROID) && __ANDROID_API__ < 21
static int CallStat(const char *path, stat_wrapper_t *sb) {
AssertBlockingAllowed();
return stat(path, sb);
}
static int CallLstat(const char *path, stat_wrapper_t *sb) {
AssertBlockingAllowed();
return lstat(path, sb);
}
#else // defined(OS_BSD) || defined(OS_MACOSX) || defined(OS_NACL) ||
// defined(OS_ANDROID) && __ANDROID_API__ < 21
static int CallStat(const char *path, stat_wrapper_t *sb) {
AssertBlockingAllowed();
return stat64(path, sb);
}
static int CallLstat(const char *path, stat_wrapper_t *sb) {
AssertBlockingAllowed();
return lstat64(path, sb);
}
#endif // !(defined(OS_BSD) || defined(OS_MACOSX) || defined(OS_NACL))
#if !defined(OS_NACL_NONSFI)
// 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
}
#if defined(OS_LINUX) || defined(OS_AIX)
// 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;
ScopedFD fd(
CreateAndOpenFdForTemporaryFileInDir(FilePath("/dev/shm"), &path));
if (fd.is_valid()) {
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(nullptr, pagesize, PROT_READ, MAP_SHARED, fd.get(), 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) || defined(OS_AIX)
bool AdvanceEnumeratorWithStat(FileEnumerator* traversal,
FilePath* out_next_path,
struct stat* out_next_stat) {
DCHECK(out_next_path);
DCHECK(out_next_stat);
*out_next_path = traversal->Next();
if (out_next_path->empty())
return false;
*out_next_stat = traversal->GetInfo().stat();
return true;
}
bool CopyFileContents(File* infile, File* outfile) {
static constexpr size_t kBufferSize = 32768;
std::vector<char> buffer(kBufferSize);
for (;;) {
ssize_t bytes_read = infile->ReadAtCurrentPos(buffer.data(), buffer.size());
if (bytes_read < 0)
return false;
if (bytes_read == 0)
return true;
// Allow for partial writes
ssize_t bytes_written_per_read = 0;
do {
ssize_t bytes_written_partial = outfile->WriteAtCurrentPos(
&buffer[bytes_written_per_read], bytes_read - bytes_written_per_read);
if (bytes_written_partial < 0)
return false;
bytes_written_per_read += bytes_written_partial;
} while (bytes_written_per_read < bytes_read);
}
NOTREACHED();
return false;
}
bool DoCopyDirectory(const FilePath& from_path,
const FilePath& to_path,
bool recursive,
bool open_exclusive) {
AssertBlockingAllowed();
// 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.
DCHECK(to_path.value().find('*') == std::string::npos);
DCHECK(from_path.value().find('*') == std::string::npos);
if (from_path.value().size() >= PATH_MAX) {
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 == real_from_path || real_from_path.IsParent(real_to_path))
return false;
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) {
DPLOG(ERROR) << "CopyDirectory() couldn't stat source directory: "
<< from_path.value();
return false;
}
FilePath from_path_base = from_path;
if (recursive && DirectoryExists(to_path)) {
// 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.
// TODO(maruel): This is not necessary anymore.
DCHECK(recursive || S_ISDIR(from_stat.st_mode));
do {
// 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 &&
!from_path_base.AppendRelativePath(current, &target_path)) {
return false;
}
if (S_ISDIR(from_stat.st_mode)) {
mode_t mode = (from_stat.st_mode & 01777) | S_IRUSR | S_IXUSR | S_IWUSR;
if (mkdir(target_path.value().c_str(), mode) == 0)
continue;
if (errno == EEXIST && !open_exclusive)
continue;
DPLOG(ERROR) << "CopyDirectory() couldn't create directory: "
<< target_path.value();
return false;
}
if (!S_ISREG(from_stat.st_mode)) {
DLOG(WARNING) << "CopyDirectory() skipping non-regular file: "
<< current.value();
continue;
}
// Add O_NONBLOCK so we can't block opening a pipe.
base::File infile(open(current.value().c_str(), O_RDONLY | O_NONBLOCK));
if (!infile.IsValid()) {
DPLOG(ERROR) << "CopyDirectory() couldn't open file: " << current.value();
return false;
}
struct stat stat_at_use;
if (fstat(infile.GetPlatformFile(), &stat_at_use) < 0) {
DPLOG(ERROR) << "CopyDirectory() couldn't stat file: " << current.value();
return false;
}
if (!S_ISREG(stat_at_use.st_mode)) {
DLOG(WARNING) << "CopyDirectory() skipping non-regular file: "
<< current.value();
continue;
}
int open_flags = O_WRONLY | O_CREAT;
// If |open_exclusive| is set then we should always create the destination
// file, so O_NONBLOCK is not necessary to ensure we don't block on the
// open call for the target file below, and since the destination will
// always be a regular file it wouldn't affect the behavior of the
// subsequent write calls anyway.
if (open_exclusive)
open_flags |= O_EXCL;
else
open_flags |= O_TRUNC | O_NONBLOCK;
// Each platform has different default file opening modes for CopyFile which
// we want to replicate here. On OS X, we use copyfile(3) which takes the
// source file's permissions into account. On the other platforms, we just
// use the base::File constructor. On Chrome OS, base::File uses a different
// set of permissions than it does on other POSIX platforms.
#if defined(OS_MACOSX)
int mode = 0600 | (stat_at_use.st_mode & 0177);
#elif defined(OS_CHROMEOS)
int mode = 0644;
#else
int mode = 0600;
#endif
base::File outfile(open(target_path.value().c_str(), open_flags, mode));
if (!outfile.IsValid()) {
DPLOG(ERROR) << "CopyDirectory() couldn't create file: "
<< target_path.value();
return false;
}
if (!CopyFileContents(&infile, &outfile)) {
DLOG(ERROR) << "CopyDirectory() couldn't copy file: " << current.value();
return false;
}
} while (AdvanceEnumeratorWithStat(&traversal, &current, &from_stat));
return true;
}
#endif // !defined(OS_NACL_NONSFI)
#if !defined(OS_MACOSX)
// Appends |mode_char| to |mode| before the optional character set encoding; see
// https://www.gnu.org/software/libc/manual/html_node/Opening-Streams.html for
// details.
std::string AppendModeCharacter(StringPiece mode, char mode_char) {
std::string result(mode.as_string());
size_t comma_pos = result.find(',');
result.insert(comma_pos == std::string::npos ? result.length() : comma_pos, 1,
mode_char);
return result;
}
#endif
} // namespace
#if !defined(OS_NACL_NONSFI)
FilePath MakeAbsoluteFilePath(const FilePath& input) {
AssertBlockingAllowed();
char full_path[PATH_MAX];
if (realpath(input.value().c_str(), full_path) == nullptr)
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) {
AssertBlockingAllowed();
const char* path_str = path.value().c_str();
stat_wrapper_t file_info;
if (CallLstat(path_str, &file_info) != 0) {
// The Windows version defines this condition as success.
return (errno == ENOENT || errno == ENOTDIR);
}
if (!S_ISDIR(file_info.st_mode))
return (unlink(path_str) == 0);
if (!recursive)
return (rmdir(path_str) == 0);
bool success = true;
base::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(); !current.empty();
current = traversal.Next()) {
if (traversal.GetInfo().IsDirectory())
directories.push(current.value());
else
success &= (unlink(current.value().c_str()) == 0);
}
while (!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,
File::Error* error) {
AssertBlockingAllowed();
if (rename(from_path.value().c_str(), to_path.value().c_str()) == 0)
return true;
if (error)
*error = File::GetLastFileError();
return false;
}
bool CopyDirectory(const FilePath& from_path,
const FilePath& to_path,
bool recursive) {
return DoCopyDirectory(from_path, to_path, recursive, false);
}
bool CopyDirectoryExcl(const FilePath& from_path,
const FilePath& to_path,
bool recursive) {
return DoCopyDirectory(from_path, to_path, recursive, true);
}
#endif // !defined(OS_NACL_NONSFI)
bool CreateLocalNonBlockingPipe(int fds[2]) {
#if defined(OS_LINUX)
return pipe2(fds, O_CLOEXEC | O_NONBLOCK) == 0;
#else
int raw_fds[2];
if (pipe(raw_fds) != 0)
return false;
ScopedFD fd_out(raw_fds[0]);
ScopedFD fd_in(raw_fds[1]);
if (!SetCloseOnExec(fd_out.get()))
return false;
if (!SetCloseOnExec(fd_in.get()))
return false;
if (!SetNonBlocking(fd_out.get()))
return false;
if (!SetNonBlocking(fd_in.get()))
return false;
fds[0] = fd_out.release();
fds[1] = fd_in.release();
return true;
#endif
}
bool SetNonBlocking(int fd) {
const int flags = fcntl(fd, F_GETFL);
if (flags == -1)
return false;
if (flags & O_NONBLOCK)
return true;
if (HANDLE_EINTR(fcntl(fd, F_SETFL, flags | O_NONBLOCK)) == -1)
return false;
return true;
}
bool SetCloseOnExec(int fd) {
#if defined(OS_NACL_NONSFI)
const int flags = 0;
#else
const int flags = fcntl(fd, F_GETFD);
if (flags == -1)
return false;
if (flags & FD_CLOEXEC)
return true;
#endif // defined(OS_NACL_NONSFI)
if (HANDLE_EINTR(fcntl(fd, F_SETFD, flags | FD_CLOEXEC)) == -1)
return false;
return true;
}
bool PathExists(const FilePath& path) {
AssertBlockingAllowed();
#if defined(OS_ANDROID)
if (path.IsContentUri()) {
return ContentUriExists(path);
}
#endif
return access(path.value().c_str(), F_OK) == 0;
}
#if !defined(OS_NACL_NONSFI)
bool PathIsWritable(const FilePath& path) {
AssertBlockingAllowed();
return access(path.value().c_str(), W_OK) == 0;
}
#endif // !defined(OS_NACL_NONSFI)
bool DirectoryExists(const FilePath& path) {
AssertBlockingAllowed();
stat_wrapper_t file_info;
if (CallStat(path.value().c_str(), &file_info) != 0)
return false;
return S_ISDIR(file_info.st_mode);
}
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;
}
#if !defined(OS_NACL_NONSFI)
int CreateAndOpenFdForTemporaryFileInDir(const FilePath& directory,
FilePath* path) {
AssertBlockingAllowed(); // For call to mkstemp().
*path = directory.Append(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_FUCHSIA)
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) {
AssertBlockingAllowed();
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) {
AssertBlockingAllowed();
DCHECK_EQ(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;
}
bool ExecutableExistsInPath(Environment* env,
const FilePath::StringType& executable) {
std::string path;
if (!env->GetVar("PATH", &path)) {
LOG(ERROR) << "No $PATH variable. Assuming no " << executable << ".";
return false;
}
for (const StringPiece& cur_path :
SplitStringPiece(path, ":", KEEP_WHITESPACE, SPLIT_WANT_NONEMPTY)) {
FilePath file(cur_path);
int permissions;
if (GetPosixFilePermissions(file.Append(executable), &permissions) &&
(permissions & FILE_PERMISSION_EXECUTE_BY_USER))
return true;
}
return false;
}
#endif // !OS_FUCHSIA
#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) // Mac implementation is in file_util_mac.mm.
FilePath GetHomeDir() {
#if defined(OS_CHROMEOS)
if (SysInfo::IsRunningOnChromeOS()) {
// On Chrome OS chrome::DIR_USER_DATA is overridden with a primary user
// homedir once it becomes available. Return / as the safe option.
return FilePath("/");
}
#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.";
#endif
FilePath rv;
if (GetTempDir(&rv))
return rv;
// Last resort.
return FilePath("/tmp");
}
#endif // !defined(OS_MACOSX)
bool CreateTemporaryFile(FilePath* path) {
AssertBlockingAllowed(); // For call to close().
FilePath directory;
if (!GetTempDir(&directory))
return false;
int fd = CreateAndOpenFdForTemporaryFileInDir(directory, path);
if (fd < 0)
return false;
close(fd);
return true;
}
FILE* CreateAndOpenTemporaryFileInDir(const FilePath& dir, FilePath* path) {
int fd = CreateAndOpenFdForTemporaryFileInDir(dir, path);
if (fd < 0)
return nullptr;
FILE* file = fdopen(fd, "a+");
if (!file)
close(fd);
return file;
}
bool CreateTemporaryFileInDir(const FilePath& dir, FilePath* temp_file) {
AssertBlockingAllowed(); // For call to close().
int fd = CreateAndOpenFdForTemporaryFileInDir(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) {
AssertBlockingAllowed(); // 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,
File::Error* error) {
AssertBlockingAllowed(); // 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 = File::OSErrorToFileError(saved_errno);
return false;
}
}
return true;
}
bool NormalizeFilePath(const FilePath& path, FilePath* normalized_path) {
FilePath real_path_result = MakeAbsoluteFilePath(path);
if (real_path_result.empty())
return false;
// To be consistant with windows, fail if |real_path_result| is a
// directory.
if (DirectoryExists(real_path_result))
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;
return S_ISLNK(st.st_mode);
}
bool GetFileInfo(const FilePath& file_path, File::Info* results) {
stat_wrapper_t file_info;
#if defined(OS_ANDROID)
if (file_path.IsContentUri()) {
File file = OpenContentUriForRead(file_path);
if (!file.IsValid())
return false;
return file.GetInfo(results);
} 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->FromStat(file_info);
return true;
}
#endif // !defined(OS_NACL_NONSFI)
FILE* OpenFile(const FilePath& filename, const char* mode) {
// 'e' is unconditionally added below, so be sure there is not one already
// present before a comma in |mode|.
DCHECK(
strchr(mode, 'e') == nullptr ||
(strchr(mode, ',') != nullptr && strchr(mode, 'e') > strchr(mode, ',')));
AssertBlockingAllowed();
FILE* result = nullptr;
#if defined(OS_MACOSX)
// macOS does not provide a mode character to set O_CLOEXEC; see
// https://developer.apple.com/legacy/library/documentation/Darwin/Reference/ManPages/man3/fopen.3.html.
const char* the_mode = mode;
#else
std::string mode_with_e(AppendModeCharacter(mode, 'e'));
const char* the_mode = mode_with_e.c_str();
#endif
do {
result = fopen(filename.value().c_str(), the_mode);
} while (!result && errno == EINTR);
#if defined(OS_MACOSX)
// Mark the descriptor as close-on-exec.
if (result)
SetCloseOnExec(fileno(result));
#endif
return result;
}
// NaCl doesn't implement system calls to open files directly.
#if !defined(OS_NACL)
FILE* FileToFILE(File file, const char* mode) {
FILE* stream = fdopen(file.GetPlatformFile(), mode);
if (stream)
file.TakePlatformFile();
return stream;
}
#endif // !defined(OS_NACL)
int ReadFile(const FilePath& filename, char* data, int max_size) {
AssertBlockingAllowed();
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, max_size));
if (IGNORE_EINTR(close(fd)) < 0)
return -1;
return bytes_read;
}
int WriteFile(const FilePath& filename, const char* data, int size) {
AssertBlockingAllowed();
int fd = HANDLE_EINTR(creat(filename.value().c_str(), 0666));
if (fd < 0)
return -1;
int bytes_written = WriteFileDescriptor(fd, data, size) ? size : -1;
if (IGNORE_EINTR(close(fd)) < 0)
return -1;
return bytes_written;
}
bool 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 false;
}
return true;
}
#if !defined(OS_NACL_NONSFI)
bool AppendToFile(const FilePath& filename, const char* data, int size) {
AssertBlockingAllowed();
bool ret = true;
int fd = HANDLE_EINTR(open(filename.value().c_str(), O_WRONLY | O_APPEND));
if (fd < 0) {
VPLOG(1) << "Unable to create file " << filename.value();
return false;
}
// This call will either write all of the data or return false.
if (!WriteFileDescriptor(fd, data, size)) {
VPLOG(1) << "Error while writing to file " << filename.value();
ret = false;
}
if (IGNORE_EINTR(close(fd)) < 0) {
VPLOG(1) << "Error while closing file " << filename.value();
return false;
}
return ret;
}
bool GetCurrentDirectory(FilePath* dir) {
// getcwd can return ENOENT, which implies it checks against the disk.
AssertBlockingAllowed();
char system_buffer[PATH_MAX] = "";
if (!getcwd(system_buffer, sizeof(system_buffer))) {
NOTREACHED();
return false;
}
*dir = FilePath(system_buffer);
return true;
}
bool SetCurrentDirectory(const FilePath& path) {
AssertBlockingAllowed();
return chdir(path.value().c_str()) == 0;
}
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.
AssertBlockingAllowed();
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) {
AssertBlockingAllowed();
return pathconf(path.value().c_str(), _PC_NAME_MAX);
}
#if !defined(OS_ANDROID)
// This is implemented in file_util_android.cc for that platform.
bool GetShmemTempDir(bool executable, FilePath* path) {
#if defined(OS_LINUX) || defined(OS_AIX)
bool disable_dev_shm = false;
#if !defined(OS_CHROMEOS)
disable_dev_shm = CommandLine::ForCurrentProcess()->HasSwitch(
switches::kDisableDevShmUsage);
#endif
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 && !disable_dev_shm) {
*path = FilePath("/dev/shm");
return true;
}
#endif // defined(OS_LINUX) || defined(OS_AIX)
return GetTempDir(path);
}
#endif // !defined(OS_ANDROID)
#if !defined(OS_MACOSX)
// Mac has its own implementation, this is for all other Posix systems.
bool CopyFile(const FilePath& from_path, const FilePath& to_path) {
AssertBlockingAllowed();
File infile;
#if defined(OS_ANDROID)
if (from_path.IsContentUri()) {
infile = OpenContentUriForRead(from_path);
} else {
infile = File(from_path, File::FLAG_OPEN | File::FLAG_READ);
}
#else
infile = File(from_path, File::FLAG_OPEN | File::FLAG_READ);
#endif
if (!infile.IsValid())
return false;
File outfile(to_path, File::FLAG_WRITE | File::FLAG_CREATE_ALWAYS);
if (!outfile.IsValid())
return false;
return CopyFileContents(&infile, &outfile);
}
#endif // !defined(OS_MACOSX)
// -----------------------------------------------------------------------------
namespace internal {
bool MoveUnsafe(const FilePath& from_path, const FilePath& to_path) {
AssertBlockingAllowed();
// 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;
}
} // namespace internal
#endif // !defined(OS_NACL_NONSFI)
} // namespace base