+/* Check the specified folder name does not contain a directory
+ * component ".." to prevent writes outside of the Maildir hierarchy. */
+static notmuch_bool_t
+check_folder_name (const char *folder)
+{
+ const char *p = folder;
+
+ for (;;) {
+ if ((p[0] == '.') && (p[1] == '.') && (p[2] == '\0' || p[2] == '/'))
+ return FALSE;
+ p = strchr (p, '/');
+ if (!p)
+ return TRUE;
+ p++;
+ }
+}
+
+/* Make the given directory, succeeding if it already exists. */
+static notmuch_bool_t
+make_directory (char *path, int mode)
+{
+ notmuch_bool_t ret;
+ char *slash;
+
+ if (mkdir (path, mode) != 0)
+ return (errno == EEXIST);
+
+ /* Sync the parent directory for durability. */
+ ret = TRUE;
+ slash = strrchr (path, '/');
+ if (slash) {
+ *slash = '\0';
+ ret = sync_dir (path);
+ *slash = '/';
+ }
+ return ret;
+}
+
+/* Make the given directory including its parent directories as necessary.
+ * Return TRUE on success, FALSE on error. */
+static notmuch_bool_t
+make_directory_and_parents (char *path, int mode)
+{
+ struct stat st;
+ char *start;
+ char *end;
+ notmuch_bool_t ret;
+
+ /* First check the common case: directory already exists. */
+ if (stat (path, &st) == 0)
+ return S_ISDIR (st.st_mode) ? TRUE : FALSE;
+
+ for (start = path; *start != '\0'; start = end + 1) {
+ /* start points to the first unprocessed character.
+ * Find the next slash from start onwards. */
+ end = strchr (start, '/');
+
+ /* If there are no more slashes then all the parent directories
+ * have been made. Now attempt to make the whole path. */
+ if (end == NULL)
+ return make_directory (path, mode);
+
+ /* Make the path up to the next slash, unless the current
+ * directory component is actually empty. */
+ if (end > start) {
+ *end = '\0';
+ ret = make_directory (path, mode);
+ *end = '/';
+ if (! ret)
+ return FALSE;
+ }
+ }
+
+ return TRUE;
+}
+
+/* Create the given maildir folder, i.e. dir and its subdirectories
+ * 'cur', 'new', 'tmp'. */
+static notmuch_bool_t
+maildir_create_folder (void *ctx, const char *dir)
+{
+ const int mode = 0700;
+ char *subdir;
+ char *tail;
+
+ /* Create 'cur' directory, including parent directories. */
+ subdir = talloc_asprintf (ctx, "%s/cur", dir);
+ if (! subdir) {
+ fprintf (stderr, "Out of memory.\n");
+ return FALSE;
+ }
+ if (! make_directory_and_parents (subdir, mode))
+ return FALSE;
+
+ tail = subdir + strlen (subdir) - 3;
+
+ /* Create 'new' directory. */
+ strcpy (tail, "new");
+ if (! make_directory (subdir, mode))
+ return FALSE;
+
+ /* Create 'tmp' directory. */
+ strcpy (tail, "tmp");
+ if (! make_directory (subdir, mode))
+ return FALSE;
+
+ talloc_free (subdir);
+ return TRUE;
+}
+