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         if (_mkdir(path, mode) >= 0) {
  39                 r = chmod_and_chown(path, mode, uid, gid);
  40                 if (r < 0)
  41                         return r;
  42         }
  43
  44         if (lstat(path, &st) < 0)
  45                 return -errno;
  46
  47         if (follow_symlink && S_ISLNK(st.st_mode)) {
  48                 _cleanup_free_ char *p = NULL;
  49
  50                 r = chase_symlinks(path, NULL, CHASE_NONEXISTENT, &p);
  51                 if (r < 0)
  52                         return r;
  53                 if (r == 0)
  54                         return mkdir_safe_internal(p, mode, uid, gid, false, _mkdir);
  55
  56                 if (lstat(p, &st) < 0)
  57                         return -errno;
  58         }
  59
  60         if ((st.st_mode & 0007) > (mode & 0007) ||
  61             (st.st_mode & 0070) > (mode & 0070) ||
  62             (st.st_mode & 0700) > (mode & 0700) ||
  63             (uid != UID_INVALID && st.st_uid != uid) ||
  64             (gid != GID_INVALID && st.st_gid != gid) ||
  65             !S_ISDIR(st.st_mode))
  66                 return -EEXIST;
  67
  68         return 0;
  69 }
  70
  71 int mkdir_safe(const char *path, mode_t mode, uid_t uid, gid_t gid, bool follow_symlink) {
  72         return mkdir_safe_internal(path, mode, uid, gid, follow_symlink, mkdir);
  73 }
  74
  75 int mkdir_parents_internal(const char *prefix, const char *path, mode_t mode, mkdir_func_t _mkdir) {
  76         const char *p, *e;
  77         int r;
  78
  79         assert(path);
  80
  81         if (prefix && !path_startswith(path, prefix))
  82                 return -ENOTDIR;
  83
  84         /* return immediately if directory exists */
  85         e = strrchr(path, '/');
  86         if (!e)
  87                 return -EINVAL;
  88
  89         if (e == path)
  90                 return 0;
  91
  92         p = strndupa(path, e - path);
  93         r = is_dir(p, true);
  94         if (r > 0)
  95                 return 0;
  96         if (r == 0)
  97                 return -ENOTDIR;
  98
  99         /* create every parent directory in the path, except the last component */
 100         p = path + strspn(path, "/");
 101         for (;;) {
 102                 char t[strlen(path) + 1];
 103
 104                 e = p + strcspn(p, "/");
 105                 p = e + strspn(e, "/");
 106
 107                 /* Is this the last component? If so, then we're
 108                  * done */
 109                 if (*p == 0)
 110                         return 0;
 111
 112                 memcpy(t, path, e - path);
 113                 t[e-path] = 0;
 114
 115                 if (prefix && path_startswith(prefix, t))
 116                         continue;
 117
 118                 r = _mkdir(t, mode);
 119                 if (r < 0 && errno != EEXIST)
 120                         return -errno;
 121         }
 122 }
 123
 124 int mkdir_parents(const char *path, mode_t mode) {
 125         return mkdir_parents_internal(NULL, path, mode, mkdir);
 126 }
 127
 128 int mkdir_p_internal(const char *prefix, const char *path, mode_t mode, mkdir_func_t _mkdir) {
 129         int r;
 130
 131         /* Like mkdir -p */
 132
 133         r = mkdir_parents_internal(prefix, path, mode, _mkdir);
 134         if (r < 0)
 135                 return r;
 136
 137         r = _mkdir(path, mode);
 138         if (r < 0 && (errno != EEXIST || is_dir(path, true) <= 0))
 139                 return -errno;
 140
 141         return 0;
 142 }
 143
 144 int mkdir_p(const char *path, mode_t mode) {
 145         return mkdir_p_internal(NULL, path, mode, mkdir);
 146 }