Function nd6_na_input

freebsd/netinet6/nd6_nbr.c:614–923

* Neighbor advertisement input handling. * * Based on RFC 2461 * Based on RFC 2462 (duplicate address detection) * * the following items are not implemented yet: * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) */

 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
 */
void
nd6_na_input(struct mbuf *m, int off, int icmp6len)
{
	struct ifnet *ifp;
	struct ip6_hdr *ip6;
	struct ifaddr *ifa;
	struct llentry *ln;
	struct mbuf *chain;
	struct nd_neighbor_advert *nd_na;
	struct in6_addr daddr6, taddr6;
	struct sockaddr_in6 sin6;
	union nd_opts ndopts;
	u_char linkhdr[LLE_MAX_LINKHDR];
	char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
	char *lladdr;
	size_t linkhdrsize;
	int flags, is_override, is_router, is_solicited;
	int lladdr_off, lladdrlen, checklink;

	NET_EPOCH_ASSERT();

	chain = NULL;
	ln = NULL;
	checklink = 0;

	/* RFC 6980: Nodes MUST silently ignore fragments */
	if(m->m_flags & M_FRAGMENTED)
		goto freeit;

	ifp = m->m_pkthdr.rcvif;
	ip6 = mtod(m, struct ip6_hdr *);
	if (__predict_false(ip6->ip6_hlim != 255)) {
		ICMP6STAT_INC(icp6s_invlhlim);
		nd6log((LOG_ERR,
		    "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
		    ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
		    ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
		goto bad;
	}

	if (m->m_len < off + icmp6len) {
		m = m_pullup(m, off + icmp6len);
		if (m == NULL) {
			IP6STAT_INC(ip6s_exthdrtoolong);
			return;
		}
	}
	ip6 = mtod(m, struct ip6_hdr *);
	nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);

	flags = nd_na->nd_na_flags_reserved;
	is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
	is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
	is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);

	taddr6 = nd_na->nd_na_target;
	if (in6_setscope(&taddr6, ifp, NULL))
		goto bad;	/* XXX: impossible */