Function fib4_check_urpf

freebsd/netinet/in_fib.c:252–269

* Performs reverse path forwarding lookup. * If @src_if is non-zero, verifies that at least 1 path goes via * this interface. * If @src_if is zero, verifies that route exist. * if @flags contains NHR_NOTDEFAULT, do not consider default route. * * Returns 1 if route matching conditions is found, 0 otherwise. */

 * Returns 1 if route matching conditions is found, 0 otherwise.
 */
int
fib4_check_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid,
  uint32_t flags, const struct ifnet *src_if)
{
	struct nhop_object *nh;
#ifdef FIB_ALGO
	struct fib_dp *dp = &V_inet_dp[fibnum];
	struct flm_lookup_key key = {.addr4 = dst };

	nh = dp->f(dp->arg, key, scopeid);
#else
	nh = lookup_nhop(fibnum, dst, scopeid);
#endif
	if (nh != NULL)
		return (check_urpf(nh, flags, src_if));

	return (0);
}

/*
 * Function returning prefix match data along with the nexthop data.