icmp6.c

嵌入式操作系统ECOS的网络开发包

		}
		nd6_rs_input(n, off, icmp6len);
		/* m stays. */
		break;

	case ND_ROUTER_ADVERT:
		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
		if (code != 0)
			goto badcode;
		if (icmp6len < sizeof(struct nd_router_advert))
			goto badlen;
		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
			/* give up local */
			nd6_ra_input(m, off, icmp6len);
			m = NULL;
			goto freeit;
		}
		nd6_ra_input(n, off, icmp6len);
		/* m stays. */
		break;

	case ND_NEIGHBOR_SOLICIT:
		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
		if (code != 0)
			goto badcode;
		if (icmp6len < sizeof(struct nd_neighbor_solicit))
			goto badlen;
		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
			/* give up local */
			nd6_ns_input(m, off, icmp6len);
			m = NULL;
			goto freeit;
		}
		nd6_ns_input(n, off, icmp6len);
		/* m stays. */
		break;

	case ND_NEIGHBOR_ADVERT:
		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
		if (code != 0)
			goto badcode;
		if (icmp6len < sizeof(struct nd_neighbor_advert))
			goto badlen;
		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
			/* give up local */
			nd6_na_input(m, off, icmp6len);
			m = NULL;
			goto freeit;
		}
		nd6_na_input(n, off, icmp6len);
		/* m stays. */
		break;

	case ND_REDIRECT:
		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
		if (code != 0)
			goto badcode;
		if (icmp6len < sizeof(struct nd_redirect))
			goto badlen;
		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
			/* give up local */
			icmp6_redirect_input(m, off);
			m = NULL;
			goto freeit;
		}
		icmp6_redirect_input(n, off);
		/* m stays. */
		break;

	case ICMP6_ROUTER_RENUMBERING:
		if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
		    code != ICMP6_ROUTER_RENUMBERING_RESULT)
			goto badcode;
		if (icmp6len < sizeof(struct icmp6_router_renum))
			goto badlen;
		break;

	default:
		nd6log((LOG_DEBUG,
		    "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
		    icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src),
		    ip6_sprintf(&ip6->ip6_dst),
		    m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
		if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
			/* ICMPv6 error: MUST deliver it by spec... */
			code = PRC_NCMDS;
			/* deliver */
		} else {
			/* ICMPv6 informational: MUST not deliver */
			break;
		}
	deliver:
		if (icmp6_notify_error(m, off, icmp6len, code)) {
			/* In this case, m should've been freed. */
			return(IPPROTO_DONE);
		}
		break;

	badcode:
		icmp6stat.icp6s_badcode++;
		break;

	badlen:
		icmp6stat.icp6s_badlen++;
		break;
	}

	/* deliver the packet to appropriate sockets */
	icmp6_rip6_input(&m, *offp);

	return IPPROTO_DONE;

 freeit:
	m_freem(m);
	return IPPROTO_DONE;
}

static int
icmp6_notify_error(m, off, icmp6len, code)
	struct mbuf *m;
	int off, icmp6len;
{
	struct icmp6_hdr *icmp6;
	struct ip6_hdr *eip6;
	u_int32_t notifymtu;
	int64_t zoneid;
	struct sockaddr_in6 icmp6src, icmp6dst;

	if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
		icmp6stat.icp6s_tooshort++;
		goto freeit;
	}
#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, off,
			 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr),
			 -1);
	icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
#else
	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
		       sizeof(*icmp6) + sizeof(struct ip6_hdr));
	if (icmp6 == NULL) {
		icmp6stat.icp6s_tooshort++;
		return(-1);
	}
#endif
	eip6 = (struct ip6_hdr *)(icmp6 + 1);

	/* Detect the upper level protocol */
	{
		void (*ctlfunc) __P((int, struct sockaddr *, void *));
		u_int8_t nxt = eip6->ip6_nxt;
		int eoff = off + sizeof(struct icmp6_hdr) +
			sizeof(struct ip6_hdr);
		struct ip6ctlparam ip6cp;
		struct in6_addr *finaldst = NULL;
		int icmp6type = icmp6->icmp6_type;
		struct ip6_frag *fh;
		struct ip6_rthdr *rth;
		struct ip6_rthdr0 *rth0;
		int rthlen;

		while (1) { /* XXX: should avoid infinite loop explicitly? */
			struct ip6_ext *eh;

			switch (nxt) {
			case IPPROTO_HOPOPTS:
			case IPPROTO_DSTOPTS:
			case IPPROTO_AH:
#ifndef PULLDOWN_TEST
				IP6_EXTHDR_CHECK(m, 0, eoff +
						 sizeof(struct ip6_ext),
						 -1);
				eh = (struct ip6_ext *)(mtod(m, caddr_t)
							+ eoff);
#else
				IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
					       eoff, sizeof(*eh));
				if (eh == NULL) {
					icmp6stat.icp6s_tooshort++;
					return(-1);
				}
#endif
				
				if (nxt == IPPROTO_AH)
					eoff += (eh->ip6e_len + 2) << 2;
				else
					eoff += (eh->ip6e_len + 1) << 3;
				nxt = eh->ip6e_nxt;
				break;
			case IPPROTO_ROUTING:
				/*
				 * When the erroneous packet contains a
				 * routing header, we should examine the
				 * header to determine the final destination.
				 * Otherwise, we can't properly update
				 * information that depends on the final
				 * destination (e.g. path MTU).
				 */
#ifndef PULLDOWN_TEST
				IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth),
						 -1);
				rth = (struct ip6_rthdr *)(mtod(m, caddr_t)
							   + eoff);
#else
				IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
					       eoff, sizeof(*rth));
				if (rth == NULL) {
					icmp6stat.icp6s_tooshort++;
					return(-1);
				}
#endif
				rthlen = (rth->ip6r_len + 1) << 3;
				/*
				 * XXX: currently there is no
				 * officially defined type other
				 * than type-0.
				 * Note that if the segment left field
				 * is 0, all intermediate hops must
				 * have been passed.
				 */
				if (rth->ip6r_segleft &&
				    rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
					int hops;

#ifndef PULLDOWN_TEST
					IP6_EXTHDR_CHECK(m, 0, eoff + rthlen,
							 -1);
					rth0 = (struct ip6_rthdr0 *)(mtod(m, caddr_t) + eoff);
#else
					IP6_EXTHDR_GET(rth0,
						       struct ip6_rthdr0 *, m,
						       eoff, rthlen);
					if (rth0 == NULL) {
						icmp6stat.icp6s_tooshort++;
						return(-1);
					}
#endif
					/* just ignore a bogus header */
					if ((rth0->ip6r0_len % 2) == 0 &&
					    (hops = rth0->ip6r0_len/2))
						finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
				}
				eoff += rthlen;
				nxt = rth->ip6r_nxt;
				break;
			case IPPROTO_FRAGMENT:
#ifndef PULLDOWN_TEST
				IP6_EXTHDR_CHECK(m, 0, eoff +
						 sizeof(struct ip6_frag),
						 -1);
				fh = (struct ip6_frag *)(mtod(m, caddr_t)
							 + eoff);
#else
				IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
					       eoff, sizeof(*fh));
				if (fh == NULL) {
					icmp6stat.icp6s_tooshort++;
					return(-1);
				}
#endif
				/*
				 * Data after a fragment header is meaningless
				 * unless it is the first fragment, but
				 * we'll go to the notify label for path MTU
				 * discovery.
				 */
				if (fh->ip6f_offlg & IP6F_OFF_MASK)
					goto notify;

				eoff += sizeof(struct ip6_frag);
				nxt = fh->ip6f_nxt;
				break;
			default:
				/*
				 * This case includes ESP and the No Next
				 * Header.  In such cases going to the notify
				 * label does not have any meaning
				 * (i.e. ctlfunc will be NULL), but we go
				 * anyway since we might have to update
				 * path MTU information.
				 */
				goto notify;
			}
		}
	  notify:
#ifndef PULLDOWN_TEST
		icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
#else
		IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
			       sizeof(*icmp6) + sizeof(struct ip6_hdr));
		if (icmp6 == NULL) {
			icmp6stat.icp6s_tooshort++;
			return(-1);
		}
#endif

		eip6 = (struct ip6_hdr *)(icmp6 + 1);
		bzero(&icmp6dst, sizeof(icmp6dst));
		icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
		icmp6dst.sin6_family = AF_INET6;
		if (finaldst == NULL)
			icmp6dst.sin6_addr = eip6->ip6_dst;
		else
			icmp6dst.sin6_addr = *finaldst;
		if ((zoneid = in6_addr2zoneid(m->m_pkthdr.rcvif,
					      &icmp6dst.sin6_addr)) < 0)
			goto freeit;
		icmp6dst.sin6_scope_id = zoneid;
		if (in6_embedscope(&icmp6dst.sin6_addr, &icmp6dst)) {
			/* should be impossbile */
			nd6log((LOG_DEBUG,
			    "icmp6_notify_error: in6_embedscope failed\n"));
			goto freeit;
		}

		/*
		 * retrieve parameters from the inner IPv6 header, and convert
		 * them into sockaddr structures.
		 */
		bzero(&icmp6src, sizeof(icmp6src));
		icmp6src.sin6_len = sizeof(struct sockaddr_in6);
		icmp6src.sin6_family = AF_INET6;
		icmp6src.sin6_addr = eip6->ip6_src;
		if ((zoneid = in6_addr2zoneid(m->m_pkthdr.rcvif,
					      &icmp6src.sin6_addr)) < 0)
			goto freeit;
		icmp6src.sin6_scope_id = zoneid;
		if (in6_embedscope(&icmp6src.sin6_addr, &icmp6src)) {
			/* should be impossbile */
			nd6log((LOG_DEBUG,
			    "icmp6_notify_error: in6_embedscope failed\n"));
			goto freeit;
		}
		icmp6src.sin6_flowinfo =
			(eip6->ip6_flow & IPV6_FLOWLABEL_MASK);

		if (finaldst == NULL)
			finaldst = &eip6->ip6_dst;
		ip6cp.ip6c_m = m;
		ip6cp.ip6c_icmp6 = icmp6;
		ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
		ip6cp.ip6c_off = eoff;
		ip6cp.ip6c_finaldst = finaldst;
		ip6cp.ip6c_src = &icmp6src;
		ip6cp.ip6c_nxt = nxt;

		if (icmp6type == ICMP6_PACKET_TOO_BIG) {
			notifymtu = ntohl(icmp6->icmp6_mtu);
			ip6cp.ip6c_cmdarg = (void *)&notifymtu;
#if !(defined(__NetBSD__) || defined(__OpenBSD__))
			icmp6_mtudisc_update(&ip6cp, 1);	/* XXX */
#endif
		}

		ctlfunc = (void (*) __P((int, struct sockaddr *, void *)))
			(inet6sw[ip6_protox[nxt]].pr_ctlinput);
		if (ctlfunc) {
			(void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
					  &ip6cp);
		}
	}
	return(0);

  freeit:
	m_freem(m);
	return(-1);
}

void
icmp6_mtudisc_update(ip6cp, validated)
	struct ip6ctlparam *ip6cp;
	int validated;
{
#if defined(__NetBSD__) || defined(__OpenBSD__)
	unsigned long rtcount;
	struct icmp6_mtudisc_callback *mc;
#endif
	struct in6_addr *dst = ip6cp->ip6c_finaldst;
	struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
	struct mbuf *m = ip6cp->ip6c_m;	/* will be necessary for scope issue */
	u_int mtu = ntohl(icmp6->icmp6_mtu);
	struct rtentry *rt = NULL;
	struct sockaddr_in6 sin6;
#ifdef __bsdi__
#ifdef NEW_STRUCT_ROUTE
	struct route ro6;
#else
	struct route_in6 ro6;
#endif
#endif

#if defined(__NetBSD__) || defined(__OpenBSD__)
	/*
	 * allow non-validated cases if memory is plenty, to make traffic
	 * from non-connected pcb happy.
	 */
	rtcount = rt_timer_count(icmp6_mtudisc_timeout_q);
	if (validated) {
		if (0 <= icmp6_mtudisc_hiwat && rtcount > icmp6_mtudisc_hiwat)
			return;
		else if (0 <= icmp6_mtudisc_lowat &&
		    rtcount > icmp6_mtudisc_lowat) {
			/*
			 * XXX nuke a victim, install the new one.
			 */
		}
	} else {
		if (0 <= icmp6_mtudisc_lowat && rtcount > icmp6_mtudisc_lowat)
			return;
	}
#else
	if (!validated)
		return;
#endif

	bzero(&sin6, sizeof(sin6));
	sin6.sin6_family = PF_INET6;
	sin6.sin6_len = sizeof(struct sockaddr_in6);
	sin6.sin6_addr = *dst;
	/* XXX normally, this won't happen */
	if (IN6_IS_ADDR_LINKLOCAL(dst)) {
		sin6.sin6_addr.s6_addr16[1] =
		    htons(m->m_pkthdr.rcvif->if_index);
	}
	/* sin6.sin6_scope_id = XXX: should be set if DST is a scoped addr */
#if defined(__NetBSD__) || defined(__OpenBSD__)
	rt = icmp6_mtudisc_clone((struct sockaddr *)&sin6);
#else
#ifdef __FreeBSD__
	rt = rtalloc1((struct sockaddr *)&sin6, 0,
		      RTF_CLONING | RTF_PRCLONING);
#else
#ifdef __bsdi__
	bcopy(&sin6, &ro6.ro_dst, sizeof(struct sockaddr_in6));
	ro6.ro_rt = 0;
	/* rtcalloc((struct route *)&ro6); */
	rtalloc((struct route *)&ro6);
	rt = ro6.ro_rt;
#else
#error no case for this particular operating system
#endif
#endif
#endif

	if (rt && (rt->rt_flags & RTF_HOST)
	    && !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
		if (mtu < IPV6_MMTU) {
				/* xxx */
			rt->rt_rmx.rmx_locks |= RTV_MTU;
		} else if (mtu < rt->rt_ifp->if_mtu &&
			   rt->rt_rmx.rmx_mtu > mtu) {
			icmp6stat.icp6s_pmtuchg++;
			rt->rt_rmx.rmx_mtu = mtu;
		}
	}
	if (rt) { /* XXX: need braces to avoid conflict with else in RTFREE. */
		RTFREE(rt);
	}

#if defined(__NetBSD__) || defined(__OpenBSD__)
	/*
	 * Notify protocols that the MTU for this destination
	 * has changed.
	 */
	for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL;
	     mc = LIST_NEXT(mc, mc_list))
		(*mc->mc_func)(&sin6.sin6_addr);
#endif
}

/*
 * Process a Node Information Query packet, based on
 * draft-ietf-ipngwg-icmp-name-lookups-07.
 * 
 * Spec incompatibilities:
 * - IPv6 Subject address handling
 * - IPv4 Subject address handling support missing
 * - Proxy reply (answer even if it's not for me)