Validate user names against allowed chars

common.c

@@ -250,3 +250,17 @@ char *strmov(char *dest, const char *src) {
     ;
   return dest-1;
 }
+
+/* New database and user names may only use these characters in their
+   identifier */
+const char name_validchars[] =
+  "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-";
+
+/* Returns true if dbname contains only characters in name_validchars. */
+int name_isclean(char* name) {
+  int reallen, cleanlen;
+  reallen = strlen(name);
+  cleanlen = strspn(name, name_validchars);
+  return (reallen == cleanlen);
+}
+