src/basic/mkdir.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2010 Lennart Poettering
   6
   7   systemd is free software; you can redistribute it and/or modify it
   8   under the terms of the GNU Lesser General Public License as published by
   9   the Free Software Foundation; either version 2.1 of the License, or
  10   (at your option) any later version.
  11
  12   systemd is distributed in the hope that it will be useful, but
  13   WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15   Lesser General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public License
  18   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  19 ***/
  20
  21 #include <errno.h>
  22 #include <stdbool.h>
  23 #include <string.h>
  24 #include <sys/stat.h>
  25
  26 #include "alloc-util.h"
  27 #include "fs-util.h"
  28 #include "macro.h"
  29 #include "mkdir.h"
  30 #include "path-util.h"
  31 #include "stat-util.h"
  32 #include "user-util.h"
  33
  34 int mkdir_safe_internal(const char *path, mode_t mode, uid_t uid, gid_t gid, bool follow_symlink, mkdir_func_t _mkdir) {
  35         struct stat st;
  36         int r;
  37
  38         assert(_mkdir != mkdir);
  39
  40         if (_mkdir(path, mode) >= 0) {
  41                 r = chmod_and_chown(path, mode, uid, gid);
  42                 if (r < 0)
  43                         return r;
  44         }
  45
  46         if (lstat(path, &st) < 0)
  47                 return -errno;
  48
  49         if (follow_symlink && S_ISLNK(st.st_mode)) {
  50                 _cleanup_free_ char *p = NULL;
  51
  52                 r = chase_symlinks(path, NULL, CHASE_NONEXISTENT, &p);
  53                 if (r < 0)
  54                         return r;
  55                 if (r == 0)
  56                         return mkdir_safe_internal(p, mode, uid, gid, false, _mkdir);
  57
  58                 if (lstat(p, &st) < 0)
  59                         return -errno;
  60         }
  61
  62         if ((st.st_mode & 0007) > (mode & 0007) ||
  63             (st.st_mode & 0070) > (mode & 0070) ||
  64             (st.st_mode & 0700) > (mode & 0700) ||
  65             (uid != UID_INVALID && st.st_uid != uid) ||
  66             (gid != GID_INVALID && st.st_gid != gid) ||
  67             !S_ISDIR(st.st_mode))
  68                 return -EEXIST;
  69
  70         return 0;
  71 }
  72
  73 int mkdir_errno_wrapper(const char *pathname, mode_t mode) {
  74         if (mkdir(pathname, mode) < 0)
  75                 return -errno;
  76         return 0;
  77 }
  78
  79 int mkdir_safe(const char *path, mode_t mode, uid_t uid, gid_t gid, bool follow_symlink) {
  80         return mkdir_safe_internal(path, mode, uid, gid, follow_symlink, mkdir_errno_wrapper);
  81 }
  82
  83 int mkdir_parents_internal(const char *prefix, const char *path, mode_t mode, mkdir_func_t _mkdir) {
  84         const char *p, *e;
  85         int r;
  86
  87         assert(path);
  88         assert(_mkdir != mkdir);
  89
  90         if (prefix && !path_startswith(path, prefix))
  91                 return -ENOTDIR;
  92
  93         /* return immediately if directory exists */
  94         e = strrchr(path, '/');
  95         if (!e)
  96                 return -EINVAL;
  97
  98         if (e == path)
  99                 return 0;
 100
 101         p = strndupa(path, e - path);
 102         r = is_dir(p, true);
 103         if (r > 0)
 104                 return 0;
 105         if (r == 0)
 106                 return -ENOTDIR;
 107
 108         /* create every parent directory in the path, except the last component */
 109         p = path + strspn(path, "/");
 110         for (;;) {
 111                 char t[strlen(path) + 1];
 112
 113                 e = p + strcspn(p, "/");
 114                 p = e + strspn(e, "/");
 115
 116                 /* Is this the last component? If so, then we're done */
 117                 if (*p == 0)
 118                         return 0;
 119
 120                 memcpy(t, path, e - path);
 121                 t[e-path] = 0;
 122
 123                 if (prefix && path_startswith(prefix, t))
 124                         continue;
 125
 126                 r = _mkdir(t, mode);
 127                 if (r < 0 && r != -EEXIST)
 128                         return r;
 129         }
 130 }
 131
 132 int mkdir_parents(const char *path, mode_t mode) {
 133         return mkdir_parents_internal(NULL, path, mode, mkdir_errno_wrapper);
 134 }
 135
 136 int mkdir_p_internal(const char *prefix, const char *path, mode_t mode, mkdir_func_t _mkdir) {
 137         int r;
 138
 139         /* Like mkdir -p */
 140
 141         assert(_mkdir != mkdir);
 142
 143         r = mkdir_parents_internal(prefix, path, mode, _mkdir);
 144         if (r < 0)
 145                 return r;
 146
 147         r = _mkdir(path, mode);
 148         if (r < 0 && (r != -EEXIST || is_dir(path, true) <= 0))
 149                 return r;
 150
 151         return 0;
 152 }
 153
 154 int mkdir_p(const char *path, mode_t mode) {
 155         return mkdir_p_internal(NULL, path, mode, mkdir_errno_wrapper);
 156 }