Function rn_lookup

freebsd/net/radix.c:211–250

* Search for exact match in given @head. * Assume host bits are cleared in @v_arg if @m_arg is not NULL * Note that prefixes with /32 or /128 masks are treated differently * from host routes. */

 * from host routes.
 */
struct radix_node *
rn_lookup(void *v_arg, void *m_arg, struct radix_head *head)
{
	struct radix_node *x;
	caddr_t netmask;

	if (m_arg != NULL) {
		/*
		 * Most common case: search exact prefix/mask
		 */
		x = rn_addmask(m_arg, head->rnh_masks, 1,
		    head->rnh_treetop->rn_offset);
		if (x == NULL)
			return (NULL);
		netmask = x->rn_key;

		x = rn_match(v_arg, head);

		while (x != NULL && x->rn_mask != netmask)
			x = x->rn_dupedkey;

		return (x);
	}

	/*
	 * Search for host address.
	 */
	if ((x = rn_match(v_arg, head)) == NULL)
		return (NULL);

	/* Check if found key is the same */
	if (LEN(x->rn_key) != LEN(v_arg) || bcmp(x->rn_key, v_arg, LEN(v_arg)))
		return (NULL);

	/* Check if this is not host route */
	if (x->rn_mask != NULL)
		return (NULL);

	return (x);
}

static int
rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip)