src/basic/mkdir.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <stdbool.h>
   5 #include <string.h>
   6
   7 #include "alloc-util.h"
   8 #include "fd-util.h"
   9 #include "format-util.h"
  10 #include "fs-util.h"
  11 #include "macro.h"
  12 #include "mkdir.h"
  13 #include "path-util.h"
  14 #include "stat-util.h"
  15 #include "stdio-util.h"
  16 #include "user-util.h"
  17
  18 int mkdir_safe_internal(
  19                 const char *path,
  20                 mode_t mode,
  21                 uid_t uid, gid_t gid,
  22                 MkdirFlags flags,
  23                 mkdir_func_t _mkdir) {
  24
  25         struct stat st;
  26         int r;
  27
  28         assert(path);
  29         assert(_mkdir && _mkdir != mkdir);
  30
  31         if (_mkdir(path, mode) >= 0) {
  32                 r = chmod_and_chown(path, mode, uid, gid);
  33                 if (r < 0)
  34                         return r;
  35         }
  36
  37         if (lstat(path, &st) < 0)
  38                 return -errno;
  39
  40         if ((flags & MKDIR_FOLLOW_SYMLINK) && S_ISLNK(st.st_mode)) {
  41                 _cleanup_free_ char *p = NULL;
  42
  43                 r = chase_symlinks(path, NULL, CHASE_NONEXISTENT, &p, NULL);
  44                 if (r < 0)
  45                         return r;
  46                 if (r == 0)
  47                         return mkdir_safe_internal(p, mode, uid, gid,
  48                                                    flags & ~MKDIR_FOLLOW_SYMLINK,
  49                                                    _mkdir);
  50
  51                 if (lstat(p, &st) < 0)
  52                         return -errno;
  53         }
  54
  55         if (!S_ISDIR(st.st_mode))
  56                 return log_full_errno(flags & MKDIR_WARN_MODE ? LOG_WARNING : LOG_DEBUG, SYNTHETIC_ERRNO(ENOTDIR),
  57                                       "Path \"%s\" already exists and is not a directory, refusing.", path);
  58         if ((st.st_mode & 0007) > (mode & 0007) ||
  59             (st.st_mode & 0070) > (mode & 0070) ||
  60             (st.st_mode & 0700) > (mode & 0700))
  61                 return log_full_errno(flags & MKDIR_WARN_MODE ? LOG_WARNING : LOG_DEBUG, SYNTHETIC_ERRNO(EEXIST),
  62                                       "Directory \"%s\" already exists, but has mode %04o that is too permissive (%04o was requested), refusing.",
  63                                       path, st.st_mode & 0777, mode);
  64
  65         if ((uid != UID_INVALID && st.st_uid != uid) ||
  66             (gid != GID_INVALID && st.st_gid != gid)) {
  67                 char u[DECIMAL_STR_MAX(uid_t)] = "-", g[DECIMAL_STR_MAX(gid_t)] = "-";
  68
  69                 if (uid != UID_INVALID)
  70                         xsprintf(u, UID_FMT, uid);
  71                 if (gid != UID_INVALID)
  72                         xsprintf(g, GID_FMT, gid);
  73                 return log_full_errno(flags & MKDIR_WARN_MODE ? LOG_WARNING : LOG_DEBUG, SYNTHETIC_ERRNO(EEXIST),
  74                                       "Directory \"%s\" already exists, but is owned by "UID_FMT":"GID_FMT" (%s:%s was requested), refusing.",
  75                                       path, st.st_uid, st.st_gid, u, g);
  76         }
  77
  78         return 0;
  79 }
  80
  81 int mkdir_errno_wrapper(const char *pathname, mode_t mode) {
  82         if (mkdir(pathname, mode) < 0)
  83                 return -errno;
  84         return 0;
  85 }
  86
  87 int mkdirat_errno_wrapper(int dirfd, const char *pathname, mode_t mode) {
  88         if (mkdirat(dirfd, pathname, mode) < 0)
  89                 return -errno;
  90         return 0;
  91 }
  92
  93 int mkdir_safe(const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags) {
  94         return mkdir_safe_internal(path, mode, uid, gid, flags, mkdir_errno_wrapper);
  95 }
  96
  97 int mkdir_parents_internal(const char *prefix, const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags, mkdir_func_t _mkdir) {
  98         const char *p, *e;
  99         int r;
 100
 101         assert(path);
 102         assert(_mkdir != mkdir);
 103
 104         if (prefix && !path_startswith(path, prefix))
 105                 return -ENOTDIR;
 106
 107         /* return immediately if directory exists */
 108         e = strrchr(path, '/');
 109         if (!e)
 110                 return 0;
 111
 112         if (e == path)
 113                 return 0;
 114
 115         p = strndupa(path, e - path);
 116         r = is_dir(p, true);
 117         if (r > 0)
 118                 return 0;
 119         if (r == 0)
 120                 return -ENOTDIR;
 121
 122         /* create every parent directory in the path, except the last component */
 123         p = path + strspn(path, "/");
 124         for (;;) {
 125                 char t[strlen(path) + 1];
 126
 127                 e = p + strcspn(p, "/");
 128                 p = e + strspn(e, "/");
 129
 130                 /* Is this the last component? If so, then we're done */
 131                 if (*p == 0)
 132                         return 0;
 133
 134                 memcpy(t, path, e - path);
 135                 t[e-path] = 0;
 136
 137                 if (prefix && path_startswith(prefix, t))
 138                         continue;
 139
 140                 if (!uid_is_valid(uid) && !gid_is_valid(gid) && flags == 0) {
 141                         r = _mkdir(t, mode);
 142                         if (r < 0 && r != -EEXIST)
 143                                 return r;
 144                 } else {
 145                         r = mkdir_safe_internal(t, mode, uid, gid, flags, _mkdir);
 146                         if (r < 0 && r != -EEXIST)
 147                                 return r;
 148                 }
 149         }
 150 }
 151
 152 int mkdir_parents(const char *path, mode_t mode) {
 153         return mkdir_parents_internal(NULL, path, mode, UID_INVALID, UID_INVALID, 0, mkdir_errno_wrapper);
 154 }
 155
 156 int mkdir_parents_safe(const char *prefix, const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags) {
 157         return mkdir_parents_internal(prefix, path, mode, uid, gid, flags, mkdir_errno_wrapper);
 158 }
 159
 160 int mkdir_p_internal(const char *prefix, const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags, mkdir_func_t _mkdir) {
 161         int r;
 162
 163         /* Like mkdir -p */
 164
 165         assert(_mkdir != mkdir);
 166
 167         r = mkdir_parents_internal(prefix, path, mode, uid, gid, flags, _mkdir);
 168         if (r < 0)
 169                 return r;
 170
 171         if (!uid_is_valid(uid) && !gid_is_valid(gid) && flags == 0) {
 172                 r = _mkdir(path, mode);
 173                 if (r < 0 && (r != -EEXIST || is_dir(path, true) <= 0))
 174                         return r;
 175         } else {
 176                 r = mkdir_safe_internal(path, mode, uid, gid, flags, _mkdir);
 177                 if (r < 0 && r != -EEXIST)
 178                         return r;
 179         }
 180
 181         return 0;
 182 }
 183
 184 int mkdir_p(const char *path, mode_t mode) {
 185         return mkdir_p_internal(NULL, path, mode, UID_INVALID, UID_INVALID, 0, mkdir_errno_wrapper);
 186 }
 187
 188 int mkdir_p_safe(const char *prefix, const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags) {
 189         return mkdir_p_internal(prefix, path, mode, uid, gid, flags, mkdir_errno_wrapper);
 190 }
 191
 192 int mkdir_p_root(const char *root, const char *p, uid_t uid, gid_t gid, mode_t m) {
 193         _cleanup_free_ char *pp = NULL;
 194         _cleanup_close_ int dfd = -1;
 195         const char *bn;
 196         int r;
 197
 198         pp = dirname_malloc(p);
 199         if (!pp)
 200                 return -ENOMEM;
 201
 202         /* Not top-level? */
 203         if (!(path_equal(pp, "/") || isempty(pp) || path_equal(pp, "."))) {
 204
 205                 /* Recurse up */
 206                 r = mkdir_p_root(root, pp, uid, gid, m);
 207                 if (r < 0)
 208                         return r;
 209         }
 210
 211         bn = basename(p);
 212         if (path_equal(bn, "/") || isempty(bn) || path_equal(bn, "."))
 213                 return 0;
 214
 215         if (!filename_is_valid(bn))
 216                 return -EINVAL;
 217
 218         dfd = chase_symlinks_and_open(pp, root, CHASE_PREFIX_ROOT, O_RDONLY|O_CLOEXEC|O_DIRECTORY, NULL);
 219         if (dfd < 0)
 220                 return dfd;
 221
 222         if (mkdirat(dfd, bn, m) < 0) {
 223                 if (errno == EEXIST)
 224                         return 0;
 225
 226                 return -errno;
 227         }
 228
 229         if (uid_is_valid(uid) || gid_is_valid(gid)) {
 230                 _cleanup_close_ int nfd = -1;
 231
 232                 nfd = openat(dfd, bn, O_RDONLY|O_CLOEXEC|O_DIRECTORY);
 233                 if (nfd < 0)
 234                         return -errno;
 235
 236                 if (fchown(nfd, uid, gid) < 0)
 237                         return -errno;
 238         }
 239
 240         return 1;
 241 }