Function callback_register

tools/ifconfig/ifconfig.c:957–969

static struct callback *callbacks = NULL;

void
callback_register(callback_func *func, void *arg)
{
	struct callback *cb;

	cb = malloc(sizeof(struct callback));
	if (cb == NULL)
		errx(1, "unable to allocate memory for callback");
	cb->cb_func = func;
	cb->cb_arg = arg;
	cb->cb_next = callbacks;
	callbacks = cb;
}

/* specially-handled commands */
static void setifaddr(const char *, int, int, const struct afswtch *);