src/basic/fs-util.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 /***
   5   This file is part of systemd.
   6
   7   Copyright 2010 Lennart Poettering
   8 ***/
   9
  10 #include <dirent.h>
  11 #include <fcntl.h>
  12 #include <limits.h>
  13 #include <stdbool.h>
  14 #include <stdint.h>
  15 #include <sys/inotify.h>
  16 #include <sys/types.h>
  17 #include <unistd.h>
  18
  19 #include "time-util.h"
  20 #include "util.h"
  21
  22 int unlink_noerrno(const char *path);
  23
  24 int rmdir_parents(const char *path, const char *stop);
  25
  26 int rename_noreplace(int olddirfd, const char *oldpath, int newdirfd, const char *newpath);
  27
  28 int readlinkat_malloc(int fd, const char *p, char **ret);
  29 int readlink_malloc(const char *p, char **r);
  30 int readlink_value(const char *p, char **ret);
  31 int readlink_and_make_absolute(const char *p, char **r);
  32
  33 int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid);
  34 int fchmod_and_chown(int fd, mode_t mode, uid_t uid, gid_t gid);
  35
  36 int fchmod_umask(int fd, mode_t mode);
  37 int fchmod_opath(int fd, mode_t m);
  38
  39 int fd_warn_permissions(const char *path, int fd);
  40
  41 #define laccess(path, mode) faccessat(AT_FDCWD, (path), (mode), AT_SYMLINK_NOFOLLOW)
  42
  43 int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gid, mode_t mode);
  44 int touch(const char *path);
  45
  46 int symlink_idempotent(const char *from, const char *to);
  47
  48 int symlink_atomic(const char *from, const char *to);
  49 int mknod_atomic(const char *path, mode_t mode, dev_t dev);
  50 int mkfifo_atomic(const char *path, mode_t mode);
  51
  52 int get_files_in_directory(const char *path, char ***list);
  53
  54 int tmp_dir(const char **ret);
  55 int var_tmp_dir(const char **ret);
  56
  57 int unlink_or_warn(const char *filename);
  58
  59 #define INOTIFY_EVENT_MAX (sizeof(struct inotify_event) + NAME_MAX + 1)
  60
  61 #define FOREACH_INOTIFY_EVENT(e, buffer, sz) \
  62         for ((e) = &buffer.ev;                                \
  63              (uint8_t*) (e) < (uint8_t*) (buffer.raw) + (sz); \
  64              (e) = (struct inotify_event*) ((uint8_t*) (e) + sizeof(struct inotify_event) + (e)->len))
  65
  66 union inotify_event_buffer {
  67         struct inotify_event ev;
  68         uint8_t raw[INOTIFY_EVENT_MAX];
  69 };
  70
  71 int inotify_add_watch_fd(int fd, int what, uint32_t mask);
  72
  73 enum {
  74         CHASE_PREFIX_ROOT = 1 << 0, /* If set, the specified path will be prefixed by the specified root before beginning the iteration */
  75         CHASE_NONEXISTENT = 1 << 1, /* If set, it's OK if the path doesn't actually exist. */
  76         CHASE_NO_AUTOFS   = 1 << 2, /* If set, return -EREMOTE if autofs mount point found */
  77         CHASE_SAFE        = 1 << 3, /* If set, return EPERM if we ever traverse from unprivileged to privileged files or directories */
  78         CHASE_OPEN        = 1 << 4, /* If set, return an O_PATH object to the final component */
  79         CHASE_TRAIL_SLASH = 1 << 5, /* If set, any trailing slash will be preserved */
  80         CHASE_STEP        = 1 << 6, /* If set, just execute a single step of the normalization */
  81 };
  82
  83 /* How many iterations to execute before returning -ELOOP */
  84 #define CHASE_SYMLINKS_MAX 32
  85
  86 int chase_symlinks(const char *path_with_prefix, const char *root, unsigned flags, char **ret);
  87
  88 int chase_symlinks_and_open(const char *path, const char *root, unsigned chase_flags, int open_flags, char **ret_path);
  89 int chase_symlinks_and_opendir(const char *path, const char *root, unsigned chase_flags, char **ret_path, DIR **ret_dir);
  90 int chase_symlinks_and_stat(const char *path, const char *root, unsigned chase_flags, char **ret_path, struct stat *ret_stat);
  91
  92 /* Useful for usage with _cleanup_(), removes a directory and frees the pointer */
  93 static inline void rmdir_and_free(char *p) {
  94         PROTECT_ERRNO;
  95         (void) rmdir(p);
  96         free(p);
  97 }
  98 DEFINE_TRIVIAL_CLEANUP_FUNC(char*, rmdir_and_free);
  99
 100 static inline void unlink_and_free(char *p) {
 101         (void) unlink_noerrno(p);
 102         free(p);
 103 }
 104 DEFINE_TRIVIAL_CLEANUP_FUNC(char*, unlink_and_free);
 105
 106 int access_fd(int fd, int mode);
 107
 108 void unlink_tempfilep(char (*p)[]);
 109 int unlinkat_deallocate(int fd, const char *name, int flags);
 110
 111 int fsync_directory_of_file(int fd);