xif
struct xif *xif_next;
struct xif *xif;
struct xif *tmp;
for (tmp = xif; tmp != NULL; tmp = tmp->xif_next) {
tmp->xif_next = xif;
xif = tmp;
struct xif *tmp;
for (tmp = xif; tmp != NULL; tmp = tmp->xif_next) {
free(xif);
xif = NULL;