src/basic/fs-util.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 #include <dirent.h>
   5 #include <fcntl.h>
   6 #include <limits.h>
   7 #include <stdbool.h>
   8 #include <stdint.h>
   9 #include <sys/inotify.h>
  10 #include <sys/stat.h>
  11 #include <sys/types.h>
  12 #include <unistd.h>
  13
  14 #include "errno-util.h"
  15 #include "time-util.h"
  16
  17 #define MODE_INVALID ((mode_t) -1)
  18
  19 /* The following macros add 1 when converting things, since 0 is a valid mode, while the pointer
  20  * NULL is special */
  21 #define PTR_TO_MODE(p) ((mode_t) ((uintptr_t) (p)-1))
  22 #define MODE_TO_PTR(u) ((void *) ((uintptr_t) (u)+1))
  23
  24 int unlink_noerrno(const char *path);
  25
  26 int rmdir_parents(const char *path, const char *stop);
  27
  28 int rename_noreplace(int olddirfd, const char *oldpath, int newdirfd, const char *newpath);
  29
  30 int readlinkat_malloc(int fd, const char *p, char **ret);
  31 int readlink_malloc(const char *p, char **r);
  32 int readlink_value(const char *p, char **ret);
  33 int readlink_and_make_absolute(const char *p, char **r);
  34
  35 int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid);
  36 int fchmod_and_chown(int fd, mode_t mode, uid_t uid, gid_t gid);
  37 int chmod_and_chown_unsafe(const char *path, mode_t mode, uid_t uid, gid_t gid);
  38
  39 int fchmod_umask(int fd, mode_t mode);
  40 int fchmod_opath(int fd, mode_t m);
  41
  42 int fd_warn_permissions(const char *path, int fd);
  43
  44 #define laccess(path, mode) faccessat(AT_FDCWD, (path), (mode), AT_SYMLINK_NOFOLLOW)
  45
  46 int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gid, mode_t mode);
  47 int touch(const char *path);
  48
  49 int symlink_idempotent(const char *from, const char *to, bool make_relative);
  50
  51 int symlink_atomic(const char *from, const char *to);
  52 int mknod_atomic(const char *path, mode_t mode, dev_t dev);
  53 int mkfifo_atomic(const char *path, mode_t mode);
  54 int mkfifoat_atomic(int dir_fd, const char *path, mode_t mode);
  55
  56 int get_files_in_directory(const char *path, char ***list);
  57
  58 int tmp_dir(const char **ret);
  59 int var_tmp_dir(const char **ret);
  60
  61 int unlink_or_warn(const char *filename);
  62
  63 #define INOTIFY_EVENT_MAX (sizeof(struct inotify_event) + NAME_MAX + 1)
  64
  65 #define FOREACH_INOTIFY_EVENT(e, buffer, sz) \
  66         for ((e) = &buffer.ev;                                \
  67              (uint8_t*) (e) < (uint8_t*) (buffer.raw) + (sz); \
  68              (e) = (struct inotify_event*) ((uint8_t*) (e) + sizeof(struct inotify_event) + (e)->len))
  69
  70 union inotify_event_buffer {
  71         struct inotify_event ev;
  72         uint8_t raw[INOTIFY_EVENT_MAX];
  73 };
  74
  75 int inotify_add_watch_fd(int fd, int what, uint32_t mask);
  76 int inotify_add_watch_and_warn(int fd, const char *pathname, uint32_t mask);
  77
  78 enum {
  79         CHASE_PREFIX_ROOT = 1 << 0, /* The specified path will be prefixed by the specified root before beginning the iteration */
  80         CHASE_NONEXISTENT = 1 << 1, /* It's OK if the path doesn't actually exist. */
  81         CHASE_NO_AUTOFS   = 1 << 2, /* Return -EREMOTE if autofs mount point found */
  82         CHASE_SAFE        = 1 << 3, /* Return EPERM if we ever traverse from unprivileged to privileged files or directories */
  83         CHASE_TRAIL_SLASH = 1 << 4, /* Any trailing slash will be preserved */
  84         CHASE_STEP        = 1 << 5, /* Just execute a single step of the normalization */
  85         CHASE_NOFOLLOW    = 1 << 6, /* Do not follow the path's right-most component. With ret_fd, when the path's
  86                                      * right-most component refers to symlink, return O_PATH fd of the symlink. */
  87         CHASE_WARN        = 1 << 7, /* Emit an appropriate warning when an error is encountered */
  88 };
  89
  90 /* How many iterations to execute before returning -ELOOP */
  91 #define CHASE_SYMLINKS_MAX 32
  92
  93 int chase_symlinks(const char *path_with_prefix, const char *root, unsigned flags, char **ret_path, int *ret_fd);
  94
  95 int chase_symlinks_and_open(const char *path, const char *root, unsigned chase_flags, int open_flags, char **ret_path);
  96 int chase_symlinks_and_opendir(const char *path, const char *root, unsigned chase_flags, char **ret_path, DIR **ret_dir);
  97 int chase_symlinks_and_stat(const char *path, const char *root, unsigned chase_flags, char **ret_path, struct stat *ret_stat, int *ret_fd);
  98
  99 /* Useful for usage with _cleanup_(), removes a directory and frees the pointer */
 100 static inline void rmdir_and_free(char *p) {
 101         PROTECT_ERRNO;
 102         (void) rmdir(p);
 103         free(p);
 104 }
 105 DEFINE_TRIVIAL_CLEANUP_FUNC(char*, rmdir_and_free);
 106
 107 static inline void unlink_and_free(char *p) {
 108         (void) unlink_noerrno(p);
 109         free(p);
 110 }
 111 DEFINE_TRIVIAL_CLEANUP_FUNC(char*, unlink_and_free);
 112
 113 int access_fd(int fd, int mode);
 114
 115 void unlink_tempfilep(char (*p)[]);
 116 int unlinkat_deallocate(int fd, const char *name, int flags);
 117
 118 int fsync_directory_of_file(int fd);
 119 int fsync_full(int fd);
 120 int fsync_path_at(int at_fd, const char *path);
 121
 122 int syncfs_path(int atfd, const char *path);
 123
 124 int open_parent(const char *path, int flags, mode_t mode);