icmp6.c

eCos操作系统源码

		for (ifa = ifp->if_addrlist.tqh_first; ifa;
		     ifa = ifa->ifa_list.tqe_next)
#endif
		{
			if (ifa->ifa_addr->sa_family != AF_INET6)
				continue;
			ifa6 = (struct in6_ifaddr *)ifa;

			if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
			    IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr,
					       &ifa6->ia_addr.sin6_addr))
				iffound = 1;

			/*
			 * IPv4-mapped addresses can only be returned by a
			 * Node Information proxy, since they represent
			 * addresses of IPv4-only nodes, which perforce do
			 * not implement this protocol.
			 * [icmp-name-lookups-07, Section 5.4]
			 * So we don't support NI_NODEADDR_FLAG_COMPAT in
			 * this function at this moment.
			 */

			/* What do we have to do about ::1? */
			switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
			case IPV6_ADDR_SCOPE_LINKLOCAL:
				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
					continue;
				break;
			case IPV6_ADDR_SCOPE_SITELOCAL:
				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
					continue;
				break;
			case IPV6_ADDR_SCOPE_GLOBAL:
				if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
					continue;
				break;
			default:
				continue;
			}

			/*
			 * check if anycast is okay.
			 * XXX: just experimental.  not in the spec.
			 */
			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
			    (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
				continue; /* we need only unicast addresses */
			if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
			    (icmp6_nodeinfo & 4) == 0) {
				continue;
			}
			addrsofif++; /* count the address */
		}
		if (iffound) {
			*ifpp = ifp;
			return(addrsofif);
		}

		addrs += addrsofif;
	}

	return(addrs);
}

static int
ni6_store_addrs(ni6, nni6, ifp0, resid)
	struct icmp6_nodeinfo *ni6, *nni6;
	struct ifnet *ifp0;
	int resid;
{
#if defined(__bsdi__) || (defined(__FreeBSD__) && __FreeBSD__ < 3)
	struct ifnet *ifp = ifp0 ? ifp0 : ifnet;
#else
	struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
#endif
	struct in6_ifaddr *ifa6;
	struct ifaddr *ifa;
	struct ifnet *ifp_dep = NULL;
	int copied = 0, allow_deprecated = 0;
	u_char *cp = (u_char *)(nni6 + 1);
	int niflags = ni6->ni_flags;
	u_int32_t ltime;
#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
	long time_second = time.tv_sec;
#endif

	if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
		return(0);	/* needless to copy */

  again:

#if defined(__bsdi__) || (defined(__FreeBSD__) && __FreeBSD__ < 3)
	for (; ifp; ifp = ifp->if_next)
#else
	for (; ifp; ifp = TAILQ_NEXT(ifp, if_list))
#endif
	{
#if defined(__bsdi__) || (defined(__FreeBSD__) && __FreeBSD__ < 3)
		for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next)
#else
		for (ifa = ifp->if_addrlist.tqh_first; ifa;
		     ifa = ifa->ifa_list.tqe_next)
#endif
		{
			if (ifa->ifa_addr->sa_family != AF_INET6)
				continue;
			ifa6 = (struct in6_ifaddr *)ifa;

			if (IFA6_IS_DEPRECATED(ifa6) &&
			    allow_deprecated == 0) {
				/*
				 * prefererred address should be put before
				 * deprecated addresses.
				 */

				/* record the interface for later search */
				if (ifp_dep == NULL)
					ifp_dep = ifp;

				continue;
			}
			else if (!IFA6_IS_DEPRECATED(ifa6) &&
				 allow_deprecated != 0)
				continue; /* we now collect deprecated addrs */

			/* What do we have to do about ::1? */
			switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
			case IPV6_ADDR_SCOPE_LINKLOCAL:
				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
					continue;
				break;
			case IPV6_ADDR_SCOPE_SITELOCAL:
				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
					continue;
				break;
			case IPV6_ADDR_SCOPE_GLOBAL:
				if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
					continue;
				break;
			default:
				continue;
			}

			/*
			 * check if anycast is okay.
			 * XXX: just experimental.  not in the spec.
			 */
			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
			    (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
				continue;
			if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
			    (icmp6_nodeinfo & 4) == 0) {
				continue;
			}

			/* now we can copy the address */
			if (resid < sizeof(struct in6_addr) +
			    sizeof(u_int32_t)) {
				/*
				 * We give up much more copy.
				 * Set the truncate flag and return.
				 */
				nni6->ni_flags |=
					NI_NODEADDR_FLAG_TRUNCATE;
				return(copied);
			}

			/*
			 * Set the TTL of the address.
			 * The TTL value should be one of the following
			 * according to the specification:
			 *
			 * 1. The remaining lifetime of a DHCP lease on the
			 *    address, or
			 * 2. The remaining Valid Lifetime of a prefix from
			 *    which the address was derived through Stateless
			 *    Autoconfiguration.
			 *
			 * Note that we currently do not support stateful
			 * address configuration by DHCPv6, so the former
			 * case can't happen.
			 *
			 * TTL must be 2^31 > TTL >= 0.
			 */
			if (ifa6->ia6_lifetime.ia6t_expire == 0)
				ltime = ND6_INFINITE_LIFETIME;
			else {
				if (ifa6->ia6_lifetime.ia6t_expire >
				    time_second) {
					ltime = ifa6->ia6_lifetime.ia6t_expire
						- time_second;
				} else
					ltime = 0;
			}
			if (ltime > 0x7fffffff)
				ltime = 0x7fffffff;
			ltime = htonl(ltime);
			
			bcopy(&ltime, cp, sizeof(u_int32_t));
			cp += sizeof(u_int32_t);

			/* copy the address itself */
			bcopy(&ifa6->ia_addr.sin6_addr, cp,
			      sizeof(struct in6_addr));
			/* XXX: KAME link-local hack; remove ifindex */
			if (IN6_IS_ADDR_LINKLOCAL(&ifa6->ia_addr.sin6_addr))
				((struct in6_addr *)cp)->s6_addr16[1] = 0;
			cp += sizeof(struct in6_addr);
			
			resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
			copied += (sizeof(struct in6_addr) +
				   sizeof(u_int32_t));
		}
		if (ifp0)	/* we need search only on the specified IF */
			break;
	}

	if (allow_deprecated == 0 && ifp_dep != NULL) {
		ifp = ifp_dep;
		allow_deprecated = 1;

		goto again;
	}

	return(copied);
}

/*
 * XXX almost dup'ed code with rip6_input.
 */
static int
icmp6_rip6_input(mp, off)
	struct	mbuf **mp;
	int	off;
{
	struct mbuf *m = *mp;
	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
	struct in6pcb *in6p;
	struct in6pcb *last = NULL;
	struct sockaddr_in6 rip6src;
	struct icmp6_hdr *icmp6;
	struct ip6_recvpktopts opts;

#ifndef PULLDOWN_TEST
	/* this is assumed to be safe. */
	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
#else
	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
	if (icmp6 == NULL) {
		/* m is already reclaimed */
		return IPPROTO_DONE;
	}
#endif

	bzero(&opts, sizeof(opts));
	bzero(&rip6src, sizeof(rip6src));
	rip6src.sin6_len = sizeof(struct sockaddr_in6);
	rip6src.sin6_family = AF_INET6;
	/* KAME hack: recover scopeid */
	(void)in6_recoverscope(&rip6src, &ip6->ip6_src, m->m_pkthdr.rcvif);

#if defined(__FreeBSD__) && __FreeBSD__ >= 3
	LIST_FOREACH(in6p, &ripcb, inp_list)
#elif defined(__OpenBSD__)
	for (in6p = rawin6pcbtable.inpt_queue.cqh_first;
	     in6p != (struct inpcb *)&rawin6pcbtable.inpt_queue;
	     in6p = in6p->inp_queue.cqe_next)
#else
	for (in6p = rawin6pcb.in6p_next;
	     in6p != &rawin6pcb; in6p = in6p->in6p_next)
#endif
	{
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
		if ((in6p->inp_vflag & INP_IPV6) == 0)
			continue;
#endif
#ifdef HAVE_NRL_INPCB
		if (!(in6p->in6p_flags & INP_IPV6))
			continue;
#endif
		if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6)
			continue;
		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
			continue;
		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
			continue;
		if (in6p->in6p_icmp6filt
		    && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
				 in6p->in6p_icmp6filt))
			continue;
		if (last) {
			struct	mbuf *n;
			if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
				if (last->in6p_flags & IN6P_CONTROLOPTS)
					ip6_savecontrol(last, ip6, n, &opts,
							NULL);
				/* strip intermediate headers */
				m_adj(n, off);
				if (sbappendaddr(&last->in6p_socket->so_rcv,
						 (struct sockaddr *)&rip6src,
						 n, opts.head) == 0) {
					/* should notify about lost packet */
					m_freem(n);
					if (opts.head) {
						m_freem(opts.head);
					}
				} else
					sorwakeup(last->in6p_socket);
				bzero(&opts, sizeof(opts));
			}
		}
		last = in6p;
	}
	if (last) {
		if (last->in6p_flags & IN6P_CONTROLOPTS)
			ip6_savecontrol(last, ip6, m, &opts, NULL);
		/* strip intermediate headers */
		m_adj(m, off);
		if (sbappendaddr(&last->in6p_socket->so_rcv,
				 (struct sockaddr *)&rip6src,
				 m, opts.head) == 0) {
			m_freem(m);
			if (opts.head)
				m_freem(opts.head);
		} else
			sorwakeup(last->in6p_socket);
	} else {
		m_freem(m);
		ip6stat.ip6s_delivered--;
	}
	return IPPROTO_DONE;
}

/*
 * Reflect the ip6 packet back to the source.
 * OFF points to the icmp6 header, counted from the top of the mbuf.
 *
 * Note: RFC 1885 required that an echo reply should be truncated if it
 * did not fit in with (return) path MTU, and KAME code supported the
 * behavior.  However, as a clarification after the RFC, this limitation
 * was removed in a revised version of the spec, RFC 2463.  We had kept the
 * old behavior, with a (non-default) ifdef block, while the new version of
 * the spec was an internet-draft status, and even after the new RFC was
 * published.  But it would rather make sense to clean the obsoleted part
 * up, and to make the code simpler at this stage.
 */
void
icmp6_reflect(m, off)
	struct	mbuf *m;
	size_t off;
{
	struct ip6_hdr *ip6;
	struct icmp6_hdr *icmp6;
	struct in6_ifaddr *ia;
	struct in6_addr t, *src = 0;
	int plen;
	int type, code;
	struct ifnet *outif = NULL;
	struct sockaddr_in6 sa6_src, sa6_dst;

	/* too short to reflect */
	if (off < sizeof(struct ip6_hdr)) {
		nd6log((LOG_DEBUG,
		    "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
		    (u_long)off, (u_long)sizeof(struct ip6_hdr),
		    __FILE__, __LINE__));
		goto bad;
	}

	/*
	 * If there are extra headers between IPv6 and ICMPv6, strip
	 * off that header first.
	 */
#ifdef DIAGNOSTIC
	if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
		panic("assumption failed in icmp6_reflect");
#endif
	if (off > sizeof(struct ip6_hdr)) {
		size_t l;
		struct ip6_hdr nip6;

		l = off - sizeof(struct ip6_hdr);
		m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
		m_adj(m, l);
		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
		if (m->m_len < l) {
			if ((m = m_pullup(m, l)) == NULL)
				return;
		}
		bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
	} else /* off == sizeof(struct ip6_hdr) */ {
		size_t l;
		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
		if (m->m_len < l) {
			if ((m = m_pullup(m, l)) == NULL)
				return;
		}
	}
	plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
	ip6 = mtod(m, struct ip6_hdr *);
	ip6->ip6_nxt = IPPROTO_ICMPV6;
	icmp6 = (struct icmp6_hdr *)(ip6 + 1);
	type = icmp6->icmp6_type; /* keep type for statistics */
	code = icmp6->icmp6_code; /* ditto. */

	t = ip6->ip6_dst;
	/*
	 * ip6_input() drops a packet if its src is multicast.
	 * So, the src is never multicast.
	 */
	ip6->ip6_dst = ip6->ip6_src;

	/*
	 * XXX: make sure to embed scope zone information, using
	 * already embedded IDs or the received interface (if any).
	 * Note that rcvif may be NULL.
	 * TODO: scoped routing case (XXX).
	 */
	bzero(&sa6_src, sizeof(sa6_src));
	sa6_src.sin6_family = AF_INET6;
	sa6_src.sin6_len = sizeof(sa6_src);
	sa6_src.sin6_addr = ip6->ip6_dst;
	in6_recoverscope(&sa6_src, &ip6->ip6_dst, m->m_pkthdr.rcvif);
	in6_embedscope(&sa6_src.sin6_addr, &sa6_src);
	ip6->ip6_dst = sa6_src.sin6_addr;

	bzero(&sa6_dst, sizeof(sa6_dst));
	sa6_dst.sin6_family = AF_INET6;
	sa6_dst.sin6_len = sizeof(sa6_dst);
	sa6_dst.sin6_addr = t;
	in6_recoverscope(&sa6_dst, &t, m->m_pkthdr.rcvif);
	in6_embedscope(&t, &sa6_dst);

	/*
	 * If the incoming packet was addressed directly to us (i.e. unicast),
	 * use dst as the src for the reply.
	 * The IN6_IFF_NOTREADY case would be VERY rare, but is possible
	 * (for example) when we encounter an error while forwarding procedure
	 * destined to a duplicated address of ours.
	 */
	for (ia = in6_ifaddr; ia; ia = ia->ia_next)
		if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) &&
		    (ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) {
			src = &t;
			break;
		}
	if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) && (m->m_flags & M_LOOP)) {
		/*
		 * This is the case if the dst is our link-local address
		 * and the sender is also ourselves.
		 */
		src = &t;
	}

	if (src == 0) {
		int e;
#ifdef NEW_STRUCT_ROUTE
		struct route ro;
#else
		struct route_in6 ro;
#endif

		/*
		 * This case matches to multicasts, our anycast, or unicasts
		 * that we do not own.  Select a source address based on the
		 * source address of the erroneous packet.
		 */
		bzero(&ro, sizeof(ro));
		src = in6_selectsrc(&sa6_src, NULL, NULL, &ro, NULL, NULL, &e);
		if (ro.ro_rt) { /* XXX: see comments in icmp6_mtudisc_update */
			RTFREE(ro.ro_rt); /* XXX: we could use this */
		}
		if (src == NULL) {
			nd6log((LOG_DEBUG,
			    "icmp6_reflect: source can't be determined: "
			    "dst=%s, error=%d\n",
			    ip6_sprintf(&sa6_src.sin6_addr), e));
			goto bad;
		}
	}

	ip6->ip6_src = *src;

	ip6->ip6_flow = 0;
	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
	ip6->ip6_vfc |= IPV6_VERSION;
	ip6->ip6_nxt = IPPROTO_ICMPV6;
	if (m->m_pkthdr.rcvif) {
		/* XXX: This may not be the outgoing i