src/basic/fs-util.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   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 "alloc-util.h"
  15 #include "errno-util.h"
  16 #include "time-util.h"
  17
  18 #define MODE_INVALID ((mode_t) -1)
  19
  20 /* The following macros add 1 when converting things, since 0 is a valid mode, while the pointer
  21  * NULL is special */
  22 #define PTR_TO_MODE(p) ((mode_t) ((uintptr_t) (p)-1))
  23 #define MODE_TO_PTR(u) ((void *) ((uintptr_t) (u)+1))
  24
  25 int unlink_noerrno(const char *path);
  26
  27 int rmdir_parents(const char *path, const char *stop);
  28
  29 int rename_noreplace(int olddirfd, const char *oldpath, int newdirfd, const char *newpath);
  30
  31 int readlinkat_malloc(int fd, const char *p, char **ret);
  32 int readlink_malloc(const char *p, char **r);
  33 int readlink_value(const char *p, char **ret);
  34 int readlink_and_make_absolute(const char *p, char **r);
  35
  36 int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid);
  37 int fchmod_and_chown(int fd, 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 futimens_opath(int fd, const struct timespec ts[2]);
  43
  44 int fd_warn_permissions(const char *path, int fd);
  45 int stat_warn_permissions(const char *path, const struct stat *st);
  46
  47 #define laccess(path, mode)                                             \
  48         (faccessat(AT_FDCWD, (path), (mode), AT_SYMLINK_NOFOLLOW) < 0 ? -errno : 0)
  49
  50 int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gid, mode_t mode);
  51 int touch(const char *path);
  52
  53 int symlink_idempotent(const char *from, const char *to, bool make_relative);
  54
  55 int symlink_atomic(const char *from, const char *to);
  56 int mknod_atomic(const char *path, mode_t mode, dev_t dev);
  57 int mkfifo_atomic(const char *path, mode_t mode);
  58 int mkfifoat_atomic(int dir_fd, const char *path, mode_t mode);
  59
  60 int get_files_in_directory(const char *path, char ***list);
  61
  62 int tmp_dir(const char **ret);
  63 int var_tmp_dir(const char **ret);
  64
  65 int unlink_or_warn(const char *filename);
  66
  67 #define INOTIFY_EVENT_MAX (sizeof(struct inotify_event) + NAME_MAX + 1)
  68
  69 #define FOREACH_INOTIFY_EVENT(e, buffer, sz) \
  70         for ((e) = &buffer.ev;                                \
  71              (uint8_t*) (e) < (uint8_t*) (buffer.raw) + (sz); \
  72              (e) = (struct inotify_event*) ((uint8_t*) (e) + sizeof(struct inotify_event) + (e)->len))
  73
  74 union inotify_event_buffer {
  75         struct inotify_event ev;
  76         uint8_t raw[INOTIFY_EVENT_MAX];
  77 };
  78
  79 int inotify_add_watch_fd(int fd, int what, uint32_t mask);
  80 int inotify_add_watch_and_warn(int fd, const char *pathname, uint32_t mask);
  81
  82 enum {
  83         CHASE_PREFIX_ROOT = 1 << 0, /* The specified path will be prefixed by the specified root before beginning the iteration */
  84         CHASE_NONEXISTENT = 1 << 1, /* It's OK if the path doesn't actually exist. */
  85         CHASE_NO_AUTOFS   = 1 << 2, /* Return -EREMOTE if autofs mount point found */
  86         CHASE_SAFE        = 1 << 3, /* Return -EPERM if we ever traverse from unprivileged to privileged files or directories */
  87         CHASE_TRAIL_SLASH = 1 << 4, /* Any trailing slash will be preserved */
  88         CHASE_STEP        = 1 << 5, /* Just execute a single step of the normalization */
  89         CHASE_NOFOLLOW    = 1 << 6, /* Do not follow the path's right-most component. With ret_fd, when the path's
  90                                      * right-most component refers to symlink, return O_PATH fd of the symlink. */
  91         CHASE_WARN        = 1 << 7, /* Emit an appropriate warning when an error is encountered */
  92 };
  93
  94 /* How many iterations to execute before returning -ELOOP */
  95 #define CHASE_SYMLINKS_MAX 32
  96
  97 int chase_symlinks(const char *path_with_prefix, const char *root, unsigned flags, char **ret_path, int *ret_fd);
  98
  99 int chase_symlinks_and_open(const char *path, const char *root, unsigned chase_flags, int open_flags, char **ret_path);
 100 int chase_symlinks_and_opendir(const char *path, const char *root, unsigned chase_flags, char **ret_path, DIR **ret_dir);
 101 int chase_symlinks_and_stat(const char *path, const char *root, unsigned chase_flags, char **ret_path, struct stat *ret_stat, int *ret_fd);
 102
 103 /* Useful for usage with _cleanup_(), removes a directory and frees the pointer */
 104 static inline char *rmdir_and_free(char *p) {
 105         PROTECT_ERRNO;
 106
 107         if (!p)
 108                 return NULL;
 109
 110         (void) rmdir(p);
 111         return mfree(p);
 112 }
 113 DEFINE_TRIVIAL_CLEANUP_FUNC(char*, rmdir_and_free);
 114
 115 static inline char* unlink_and_free(char *p) {
 116         if (!p)
 117                 return NULL;
 118
 119         (void) unlink_noerrno(p);
 120         return mfree(p);
 121 }
 122 DEFINE_TRIVIAL_CLEANUP_FUNC(char*, unlink_and_free);
 123
 124 int access_fd(int fd, int mode);
 125
 126 void unlink_tempfilep(char (*p)[]);
 127
 128 typedef enum UnlinkDeallocateFlags {
 129         UNLINK_REMOVEDIR = 1 << 0,
 130         UNLINK_ERASE     = 1 << 1,
 131 } UnlinkDeallocateFlags;
 132
 133 int unlinkat_deallocate(int fd, const char *name, UnlinkDeallocateFlags flags);
 134
 135 int fsync_directory_of_file(int fd);
 136 int fsync_full(int fd);
 137 int fsync_path_at(int at_fd, const char *path);
 138
 139 int syncfs_path(int atfd, const char *path);
 140
 141 int open_parent(const char *path, int flags, mode_t mode);
 142
 143 int path_is_encrypted(const char *path);
 144
 145 int conservative_renameat(int olddirfd, const char *oldpath, int newdirfd, const char *newpath);
 146 static inline int conservative_rename(const char *oldpath, const char *newpath) {
 147         return conservative_renameat(AT_FDCWD, oldpath, AT_FDCWD, newpath);
 148 }