Function fib_select_algo_initial

freebsd/net/route/fib_algo.c:1585–1631

* Called when new route table is created. * Selects, allocates and attaches fib algo for the table. */

 * Selects, allocates and attaches fib algo for the table.
 */
int
fib_select_algo_initial(struct rib_head *rh)
{
	struct fib_lookup_module *flm;
	struct fib_data *fd = NULL;
	enum flm_op_result result;
	struct epoch_tracker et;
	int error = 0;

	flm = fib_check_best_algo(rh, NULL);
	if (flm == NULL) {
		RH_PRINTF(LOG_CRIT, rh, "no algo selected");
		return (ENOENT);
	}
	RH_PRINTF(LOG_INFO, rh, "selected algo %s", flm->flm_name);

	NET_EPOCH_ENTER(et);
	RIB_WLOCK(rh);
	result = setup_fd_instance(flm, rh, NULL, &fd, false);
	RIB_WUNLOCK(rh);
	NET_EPOCH_EXIT(et);

	RH_PRINTF(LOG_DEBUG, rh, "result=%d fd=%p", result, fd);
	if (result == FLM_SUCCESS) {

		/*
		 * Attach datapath directly to avoid multiple reallocations
		 * during fib growth
		 */
		struct fib_dp_header *fdp;
		struct fib_dp **pdp;

		pdp = get_family_dp_ptr(rh->rib_family);
		if (pdp != NULL) {
			fdp = get_fib_dp_header(*pdp);
			fdp->fdh_idx[fd->fd_fibnum] = fd->fd_dp;
			FD_PRINTF(LOG_INFO, fd, "datapath attached");
		}
	} else {
		error = EINVAL;
		RH_PRINTF(LOG_CRIT, rh, "unable to setup algo %s", flm->flm_name);
	}

	fib_unref_algo(flm);

	return (error);
}

/*
 * Registers fib lookup module within the subsystem.