Function nd6_cache_lladdr

freebsd/netinet6/nd6.c:1923–2097

* Create neighbor cache entry and cache link-layer address, * on reception of inbound ND6 packets. (RS/RA/NS/redirect) * * type - ICMP6 type * code - type dependent information * */

 *
 */
void
nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
    int lladdrlen, int type, int code)
{
	struct llentry *ln = NULL, *ln_tmp;
	int is_newentry;
	int do_update;
	int olladdr;
	int llchange;
	int flags;
	uint16_t router = 0;
	struct sockaddr_in6 sin6;
	struct mbuf *chain = NULL;
	u_char linkhdr[LLE_MAX_LINKHDR];
	size_t linkhdrsize;
	int lladdr_off;

	NET_EPOCH_ASSERT();
	IF_AFDATA_UNLOCK_ASSERT(ifp);

	KASSERT(ifp != NULL, ("%s: ifp == NULL", __func__));
	KASSERT(from != NULL, ("%s: from == NULL", __func__));

	/* nothing must be updated for unspecified address */
	if (IN6_IS_ADDR_UNSPECIFIED(from))
		return;

	/*
	 * Validation about ifp->if_addrlen and lladdrlen must be done in
	 * the caller.
	 *
	 * XXX If the link does not have link-layer adderss, what should
	 * we do? (ifp->if_addrlen == 0)
	 * Spec says nothing in sections for RA, RS and NA.  There's small
	 * description on it in NS section (RFC 2461 7.2.3).
	 */
	flags = lladdr ? LLE_EXCLUSIVE : 0;
	ln = nd6_lookup(from, flags, ifp);
	is_newentry = 0;
	if (ln == NULL) {
		flags |= LLE_EXCLUSIVE;
		ln = nd6_alloc(from, 0, ifp);
		if (ln == NULL)
			return;

		/*
		 * Since we already know all the data for the new entry,
		 * fill it before insertion.
		 */
		if (lladdr != NULL) {
			linkhdrsize = sizeof(linkhdr);
			if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
			    linkhdr, &linkhdrsize, &lladdr_off) != 0)
				return;
			lltable_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
			    lladdr_off);
		}