src/basic/stat-util.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 #include <stdbool.h>
   5 #include <stddef.h>
   6 #include <sys/stat.h>
   7 #include <sys/statfs.h>
   8 #include <sys/types.h>
   9 #include <sys/vfs.h>
  10
  11 #include "macro.h"
  12
  13 int is_symlink(const char *path);
  14 int is_dir(const char *path, bool follow);
  15 int is_dir_fd(int fd);
  16 int is_device_node(const char *path);
  17
  18 int dir_is_empty(const char *path);
  19
  20 static inline int dir_is_populated(const char *path) {
  21         int r;
  22         r = dir_is_empty(path);
  23         if (r < 0)
  24                 return r;
  25         return !r;
  26 }
  27
  28 bool null_or_empty(struct stat *st) _pure_;
  29 int null_or_empty_path(const char *fn);
  30 int null_or_empty_fd(int fd);
  31
  32 int path_is_read_only_fs(const char *path);
  33
  34 int files_same(const char *filea, const char *fileb, int flags);
  35
  36 /* The .f_type field of struct statfs is really weird defined on
  37  * different archs. Let's give its type a name. */
  38 typedef typeof(((struct statfs*)NULL)->f_type) statfs_f_type_t;
  39
  40 bool is_fs_type(const struct statfs *s, statfs_f_type_t magic_value) _pure_;
  41 int fd_is_fs_type(int fd, statfs_f_type_t magic_value);
  42 int path_is_fs_type(const char *path, statfs_f_type_t magic_value);
  43
  44 bool is_temporary_fs(const struct statfs *s) _pure_;
  45 bool is_network_fs(const struct statfs *s) _pure_;
  46
  47 int fd_is_temporary_fs(int fd);
  48 int fd_is_network_fs(int fd);
  49
  50 int fd_is_network_ns(int fd);
  51
  52 int path_is_temporary_fs(const char *path);
  53
  54 /* Because statfs.t_type can be int on some architectures, we have to cast
  55  * the const magic to the type, otherwise the compiler warns about
  56  * signed/unsigned comparison, because the magic can be 32 bit unsigned.
  57  */
  58 #define F_TYPE_EQUAL(a, b) (a == (typeof(a)) b)
  59
  60 int stat_verify_regular(const struct stat *st);
  61 int fd_verify_regular(int fd);
  62
  63 int stat_verify_directory(const struct stat *st);
  64 int fd_verify_directory(int fd);
  65
  66 /* glibc and the Linux kernel have different ideas about the major/minor size. These calls will check whether the
  67  * specified major is valid by the Linux kernel's standards, not by glibc's. Linux has 20bits of minor, and 12 bits of
  68  * major space. See MINORBITS in linux/kdev_t.h in the kernel sources. (If you wonder why we define _y here, instead of
  69  * comparing directly >= 0: it's to trick out -Wtype-limits, which would otherwise complain if the type is unsigned, as
  70  * such a test would be pointless in such a case.) */
  71
  72 #define DEVICE_MAJOR_VALID(x)                                           \
  73         ({                                                              \
  74                 typeof(x) _x = (x), _y = 0;                             \
  75                 _x >= _y && _x < (UINT32_C(1) << 12);                   \
  76                                                                         \
  77         })
  78
  79 #define DEVICE_MINOR_VALID(x)                                           \
  80         ({                                                              \
  81                 typeof(x) _x = (x), _y = 0;                             \
  82                 _x >= _y && _x < (UINT32_C(1) << 20);                   \
  83         })
  84
  85 int device_path_make_major_minor(mode_t mode, dev_t devno, char **ret);
  86 int device_path_make_canonical(mode_t mode, dev_t devno, char **ret);
  87 int device_path_parse_major_minor(const char *path, mode_t *ret_mode, dev_t *ret_devno);