382 lines
9.2 KiB
C
382 lines
9.2 KiB
C
/* SPDX-License-Identifier: LGPL-2.1+ */
|
|
|
|
#include <dirent.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <linux/magic.h>
|
|
#include <sched.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/statvfs.h>
|
|
#include <sys/types.h>
|
|
#include <unistd.h>
|
|
|
|
#include "alloc-util.h"
|
|
#include "dirent-util.h"
|
|
#include "fd-util.h"
|
|
#include "fs-util.h"
|
|
#include "macro.h"
|
|
#include "missing.h"
|
|
#include "parse-util.h"
|
|
#include "stat-util.h"
|
|
#include "string-util.h"
|
|
|
|
int is_symlink(const char *path) {
|
|
struct stat info;
|
|
|
|
assert(path);
|
|
|
|
if (lstat(path, &info) < 0)
|
|
return -errno;
|
|
|
|
return !!S_ISLNK(info.st_mode);
|
|
}
|
|
|
|
int is_dir(const char* path, bool follow) {
|
|
struct stat st;
|
|
int r;
|
|
|
|
assert(path);
|
|
|
|
if (follow)
|
|
r = stat(path, &st);
|
|
else
|
|
r = lstat(path, &st);
|
|
if (r < 0)
|
|
return -errno;
|
|
|
|
return !!S_ISDIR(st.st_mode);
|
|
}
|
|
|
|
int is_dir_fd(int fd) {
|
|
struct stat st;
|
|
|
|
if (fstat(fd, &st) < 0)
|
|
return -errno;
|
|
|
|
return !!S_ISDIR(st.st_mode);
|
|
}
|
|
|
|
int is_device_node(const char *path) {
|
|
struct stat info;
|
|
|
|
assert(path);
|
|
|
|
if (lstat(path, &info) < 0)
|
|
return -errno;
|
|
|
|
return !!(S_ISBLK(info.st_mode) || S_ISCHR(info.st_mode));
|
|
}
|
|
|
|
int dir_is_empty_at(int dir_fd, const char *path) {
|
|
_cleanup_close_ int fd = -1;
|
|
_cleanup_closedir_ DIR *d = NULL;
|
|
struct dirent *de;
|
|
|
|
if (path)
|
|
fd = openat(dir_fd, path, O_RDONLY|O_DIRECTORY|O_CLOEXEC);
|
|
else
|
|
fd = fcntl(fd, F_DUPFD_CLOEXEC, 3);
|
|
if (fd < 0)
|
|
return -errno;
|
|
|
|
d = fdopendir(fd);
|
|
if (!d)
|
|
return -errno;
|
|
fd = -1;
|
|
|
|
FOREACH_DIRENT(de, d, return -errno)
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
bool null_or_empty(struct stat *st) {
|
|
assert(st);
|
|
|
|
if (S_ISREG(st->st_mode) && st->st_size <= 0)
|
|
return true;
|
|
|
|
/* We don't want to hardcode the major/minor of /dev/null,
|
|
* hence we do a simpler "is this a device node?" check. */
|
|
|
|
if (S_ISCHR(st->st_mode) || S_ISBLK(st->st_mode))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
int null_or_empty_path(const char *fn) {
|
|
struct stat st;
|
|
|
|
assert(fn);
|
|
|
|
if (stat(fn, &st) < 0)
|
|
return -errno;
|
|
|
|
return null_or_empty(&st);
|
|
}
|
|
|
|
int null_or_empty_fd(int fd) {
|
|
struct stat st;
|
|
|
|
assert(fd >= 0);
|
|
|
|
if (fstat(fd, &st) < 0)
|
|
return -errno;
|
|
|
|
return null_or_empty(&st);
|
|
}
|
|
|
|
int path_is_read_only_fs(const char *path) {
|
|
struct statvfs st;
|
|
|
|
assert(path);
|
|
|
|
if (statvfs(path, &st) < 0)
|
|
return -errno;
|
|
|
|
if (st.f_flag & ST_RDONLY)
|
|
return true;
|
|
|
|
/* On NFS, statvfs() might not reflect whether we can actually
|
|
* write to the remote share. Let's try again with
|
|
* access(W_OK) which is more reliable, at least sometimes. */
|
|
if (access(path, W_OK) < 0 && errno == EROFS)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
int files_same(const char *filea, const char *fileb, int flags) {
|
|
struct stat a, b;
|
|
|
|
assert(filea);
|
|
assert(fileb);
|
|
|
|
if (fstatat(AT_FDCWD, filea, &a, flags) < 0)
|
|
return -errno;
|
|
|
|
if (fstatat(AT_FDCWD, fileb, &b, flags) < 0)
|
|
return -errno;
|
|
|
|
return a.st_dev == b.st_dev &&
|
|
a.st_ino == b.st_ino;
|
|
}
|
|
|
|
bool is_fs_type(const struct statfs *s, statfs_f_type_t magic_value) {
|
|
assert(s);
|
|
assert_cc(sizeof(statfs_f_type_t) >= sizeof(s->f_type));
|
|
|
|
return F_TYPE_EQUAL(s->f_type, magic_value);
|
|
}
|
|
|
|
int fd_is_fs_type(int fd, statfs_f_type_t magic_value) {
|
|
struct statfs s;
|
|
|
|
if (fstatfs(fd, &s) < 0)
|
|
return -errno;
|
|
|
|
return is_fs_type(&s, magic_value);
|
|
}
|
|
|
|
int path_is_fs_type(const char *path, statfs_f_type_t magic_value) {
|
|
_cleanup_close_ int fd = -1;
|
|
|
|
fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_PATH);
|
|
if (fd < 0)
|
|
return -errno;
|
|
|
|
return fd_is_fs_type(fd, magic_value);
|
|
}
|
|
|
|
bool is_temporary_fs(const struct statfs *s) {
|
|
return is_fs_type(s, TMPFS_MAGIC) ||
|
|
is_fs_type(s, RAMFS_MAGIC);
|
|
}
|
|
|
|
bool is_network_fs(const struct statfs *s) {
|
|
return is_fs_type(s, CIFS_MAGIC_NUMBER) ||
|
|
is_fs_type(s, CODA_SUPER_MAGIC) ||
|
|
is_fs_type(s, NCP_SUPER_MAGIC) ||
|
|
is_fs_type(s, NFS_SUPER_MAGIC) ||
|
|
is_fs_type(s, SMB_SUPER_MAGIC) ||
|
|
is_fs_type(s, V9FS_MAGIC) ||
|
|
is_fs_type(s, AFS_SUPER_MAGIC) ||
|
|
is_fs_type(s, OCFS2_SUPER_MAGIC);
|
|
}
|
|
|
|
int fd_is_temporary_fs(int fd) {
|
|
struct statfs s;
|
|
|
|
if (fstatfs(fd, &s) < 0)
|
|
return -errno;
|
|
|
|
return is_temporary_fs(&s);
|
|
}
|
|
|
|
int fd_is_network_fs(int fd) {
|
|
struct statfs s;
|
|
|
|
if (fstatfs(fd, &s) < 0)
|
|
return -errno;
|
|
|
|
return is_network_fs(&s);
|
|
}
|
|
|
|
int path_is_temporary_fs(const char *path) {
|
|
_cleanup_close_ int fd = -1;
|
|
|
|
fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_PATH);
|
|
if (fd < 0)
|
|
return -errno;
|
|
|
|
return fd_is_temporary_fs(fd);
|
|
}
|
|
|
|
int stat_verify_regular(const struct stat *st) {
|
|
assert(st);
|
|
|
|
/* Checks whether the specified stat() structure refers to a regular file. If not returns an appropriate error
|
|
* code. */
|
|
|
|
if (S_ISDIR(st->st_mode))
|
|
return -EISDIR;
|
|
|
|
if (S_ISLNK(st->st_mode))
|
|
return -ELOOP;
|
|
|
|
if (!S_ISREG(st->st_mode))
|
|
return -EBADFD;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int fd_verify_regular(int fd) {
|
|
struct stat st;
|
|
|
|
assert(fd >= 0);
|
|
|
|
if (fstat(fd, &st) < 0)
|
|
return -errno;
|
|
|
|
return stat_verify_regular(&st);
|
|
}
|
|
|
|
int stat_verify_directory(const struct stat *st) {
|
|
assert(st);
|
|
|
|
if (S_ISLNK(st->st_mode))
|
|
return -ELOOP;
|
|
|
|
if (!S_ISDIR(st->st_mode))
|
|
return -ENOTDIR;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int fd_verify_directory(int fd) {
|
|
struct stat st;
|
|
|
|
assert(fd >= 0);
|
|
|
|
if (fstat(fd, &st) < 0)
|
|
return -errno;
|
|
|
|
return stat_verify_directory(&st);
|
|
}
|
|
|
|
int device_path_make_major_minor(mode_t mode, dev_t devno, char **ret) {
|
|
const char *t;
|
|
|
|
/* Generates the /dev/{char|block}/MAJOR:MINOR path for a dev_t */
|
|
|
|
if (S_ISCHR(mode))
|
|
t = "char";
|
|
else if (S_ISBLK(mode))
|
|
t = "block";
|
|
else
|
|
return -ENODEV;
|
|
|
|
if (asprintf(ret, "/dev/%s/%u:%u", t, major(devno), minor(devno)) < 0)
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int device_path_make_canonical(mode_t mode, dev_t devno, char **ret) {
|
|
_cleanup_free_ char *p = NULL;
|
|
int r;
|
|
|
|
/* Finds the canonical path for a device, i.e. resolves the /dev/{char|block}/MAJOR:MINOR path to the end. */
|
|
|
|
assert(ret);
|
|
|
|
if (major(devno) == 0 && minor(devno) == 0) {
|
|
char *s;
|
|
|
|
/* A special hack to make sure our 'inaccessible' device nodes work. They won't have symlinks in
|
|
* /dev/block/ and /dev/char/, hence we handle them specially here. */
|
|
|
|
if (S_ISCHR(mode))
|
|
s = strdup("/run/systemd/inaccessible/chr");
|
|
else if (S_ISBLK(mode))
|
|
s = strdup("/run/systemd/inaccessible/blk");
|
|
else
|
|
return -ENODEV;
|
|
|
|
if (!s)
|
|
return -ENOMEM;
|
|
|
|
*ret = s;
|
|
return 0;
|
|
}
|
|
|
|
r = device_path_make_major_minor(mode, devno, &p);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
return chase_symlinks(p, NULL, 0, ret);
|
|
}
|
|
|
|
int device_path_parse_major_minor(const char *path, mode_t *ret_mode, dev_t *ret_devno) {
|
|
mode_t mode;
|
|
dev_t devno;
|
|
int r;
|
|
|
|
/* Tries to extract the major/minor directly from the device path if we can. Handles /dev/block/ and /dev/char/
|
|
* paths, as well out synthetic inaccessible device nodes. Never goes to disk. Returns -ENODEV if the device
|
|
* path cannot be parsed like this. */
|
|
|
|
if (path_equal(path, "/run/systemd/inaccessible/chr")) {
|
|
mode = S_IFCHR;
|
|
devno = makedev(0, 0);
|
|
} else if (path_equal(path, "/run/systemd/inaccessible/blk")) {
|
|
mode = S_IFBLK;
|
|
devno = makedev(0, 0);
|
|
} else {
|
|
const char *w;
|
|
|
|
w = path_startswith(path, "/dev/block/");
|
|
if (w)
|
|
mode = S_IFBLK;
|
|
else {
|
|
w = path_startswith(path, "/dev/char/");
|
|
if (!w)
|
|
return -ENODEV;
|
|
|
|
mode = S_IFCHR;
|
|
}
|
|
|
|
r = parse_dev(w, &devno);
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
|
|
if (ret_mode)
|
|
*ret_mode = mode;
|
|
if (ret_devno)
|
|
*ret_devno = devno;
|
|
|
|
return 0;
|
|
}
|