src/basic/chase-symlinks.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include <dirent.h>
   5 #include <stdio.h>
   6
   7 #include "stat-util.h"
   8
   9 enum {
  10         CHASE_PREFIX_ROOT = 1 << 0, /* The specified path will be prefixed by the specified root before beginning the iteration */
  11         CHASE_NONEXISTENT = 1 << 1, /* It's OK if the path doesn't actually exist. */
  12         CHASE_NO_AUTOFS   = 1 << 2, /* Return -EREMOTE if autofs mount point found */
  13         CHASE_SAFE        = 1 << 3, /* Return -EPERM if we ever traverse from unprivileged to privileged files or directories */
  14         CHASE_TRAIL_SLASH = 1 << 4, /* Any trailing slash will be preserved */
  15         CHASE_STEP        = 1 << 5, /* Just execute a single step of the normalization */
  16         CHASE_NOFOLLOW    = 1 << 6, /* Do not follow the path's right-most component. With ret_fd, when the path's
  17                                      * right-most component refers to symlink, return O_PATH fd of the symlink. */
  18         CHASE_WARN        = 1 << 7, /* Emit an appropriate warning when an error is encountered */
  19 };
  20
  21 bool unsafe_transition(const struct stat *a, const struct stat *b);
  22
  23 /* How many iterations to execute before returning -ELOOP */
  24 #define CHASE_SYMLINKS_MAX 32
  25
  26 int chase_symlinks(const char *path_with_prefix, const char *root, unsigned flags, char **ret_path, int *ret_fd);
  27
  28 int chase_symlinks_and_open(const char *path, const char *root, unsigned chase_flags, int open_flags, char **ret_path);
  29 int chase_symlinks_and_opendir(const char *path, const char *root, unsigned chase_flags, char **ret_path, DIR **ret_dir);
  30 int chase_symlinks_and_stat(const char *path, const char *root, unsigned chase_flags, char **ret_path, struct stat *ret_stat, int *ret_fd);