static bridge_t *add_bridge(bridge_t **head)
{
   bridge_t *bridge;

   if ((bridge = malloc(sizeof(*bridge))) != NULL) {
      memset(bridge, 0, sizeof(*bridge));
      bridge->next = *head;
      *head = bridge;
   }
   return bridge;
}
static bridge_t *add_bridge(bridge_t **head)
{
   bridge_t *bridge;

   if ((bridge = malloc(sizeof(*bridge))) != NULL) {
      memset(bridge, 0, sizeof(*bridge));
      bridge->next = *head;
      *head = bridge;
   }
   return bridge;
}