in6_gif.c

来自「eCos操作系统源码」· C语言 代码 · 共 662 行 · 第 1/2 页

	if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
		ip6->ip6_dst = sin6_dst->sin6_addr;
	else  {
		m_freem(m);
		return ENETUNREACH;
	}
	if (ifp->if_flags & IFF_LINK1)
		ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
	else
		ip_ecn_ingress(ECN_NOCARE, &otos, &itos);
	ip6->ip6_flow &= ~ntohl(0xff00000);
	ip6->ip6_flow |= htonl((u_int32_t)otos << 20);

#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
	time_second = time.tv_sec;
#endif
	/*
	 * compare address family just for safety.  other validity checks
	 * are made in in6_selectsrc() called from ip6_output().
	 */
	if (sc->gif_ro6.ro_rt && (dst->sin6_family != sin6_dst->sin6_family ||
				  sc->rtcache_expire == 0 ||
				  time_second >= sc->rtcache_expire)) {
		/*
		 * If the cached route is not valid or has expired,
		 * clear the stale cache and let ip6_output make a new cached
		 * route.
		 */
		RTFREE(sc->gif_ro6.ro_rt);
		sc->gif_ro6.ro_rt = NULL;
	}

#ifdef IPV6_MINMTU
	/*
	 * force fragmentation to minimum MTU, to avoid path MTU discovery.
	 * it is too painful to ask for resend of inner packet, to achieve
	 * path MTU discovery for encapsulated packets.
	 */
	error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL);
#else
	error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL);
#endif

	/*
	 * if a (new) cached route has been created in ip6_output(), extend
	 * the expiration time.
	 */
	if (sc->gif_ro6.ro_rt && time_second >= sc->rtcache_expire)
		sc->rtcache_expire = time_second + in6_gif_rtcachettl;

	return(error);
#endif	/* __OpenBSD__ */
}

int in6_gif_input(mp, offp, proto)
	struct mbuf **mp;
	int *offp, proto;
{
	struct mbuf *m = *mp;
	struct ifnet *gifp = NULL;
	struct ip6_hdr *ip6;
#ifndef __OpenBSD__
	int af = 0;
	u_int32_t otos;
#endif

	ip6 = mtod(m, struct ip6_hdr *);

	gifp = (struct ifnet *)encap_getarg(m);

	if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
		m_freem(m);
		ip6stat.ip6s_nogif++;
		return IPPROTO_DONE;
	}
#ifndef USE_ENCAPCHECK
	if (!gif_validate6(ip6, (struct gif_softc *)gifp, m->m_pkthdr.rcvif)) {
		m_freem(m);
		ip6stat.ip6s_nogif++;
		return IPPROTO_DONE;
	}
#endif

#ifdef __OpenBSD__
	m->m_pkthdr.rcvif = gifp;
	gifp->if_ipackets++;
	gifp->if_ibytes += m->m_pkthdr.len;
	ipip_input(m, *offp, gifp);
	return IPPROTO_DONE;
#else
	otos = ip6->ip6_flow;
	m_adj(m, *offp);

	switch (proto) {
#ifdef INET
	case IPPROTO_IPV4:
	    {
		struct ip *ip;
		u_int8_t otos8;
		af = AF_INET;
		otos8 = (ntohl(otos) >> 20) & 0xff;
		if (m->m_len < sizeof(*ip)) {
			m = m_pullup(m, sizeof(*ip));
			if (!m)
				return IPPROTO_DONE;
		}
		ip = mtod(m, struct ip *);
		if (gifp->if_flags & IFF_LINK1)
			ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
		else
			ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
		break;
	    }
#endif /* INET */
#ifdef INET6
	case IPPROTO_IPV6:
	    {
		struct ip6_hdr *ip6;
		af = AF_INET6;
		if (m->m_len < sizeof(*ip6)) {
			m = m_pullup(m, sizeof(*ip6));
			if (!m)
				return IPPROTO_DONE;
		}
		ip6 = mtod(m, struct ip6_hdr *);
		if (gifp->if_flags & IFF_LINK1)
			ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6->ip6_flow);
		else
			ip6_ecn_egress(ECN_NOCARE, &otos, &ip6->ip6_flow);
		break;
	    }
#endif
#if defined(__NetBSD__) && defined(ISO)
	case IPPROTO_EON:
		af = AF_ISO;
		break;
#endif
	default:
		ip6stat.ip6s_nogif++;
		m_freem(m);
		return IPPROTO_DONE;
	}
		
	gif_input(m, af, gifp);
	return IPPROTO_DONE;
#endif
}

/*
 * validate outer address.
 */
static int
gif_validate6(ip6, sc, ifp)
	const struct ip6_hdr *ip6;
	struct gif_softc *sc;
	struct ifnet *ifp;
{
	struct sockaddr_in6 *src, *dst;

	src = (struct sockaddr_in6 *)sc->gif_psrc;
	dst = (struct sockaddr_in6 *)sc->gif_pdst;

	/* check for address match */
	if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
	    !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
		return 0;

	/* martian filters on outer source - done in ip6_input */

	/* ingress filters on outer source */
	if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) {
		struct sockaddr_in6 sin6;
		struct rtentry *rt;

		bzero(&sin6, sizeof(sin6));
		sin6.sin6_family = AF_INET6;
		sin6.sin6_len = sizeof(struct sockaddr_in6);
		sin6.sin6_addr = ip6->ip6_src;
		/* XXX scopeid */
#ifdef __FreeBSD__
		rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
#else
		rt = rtalloc1((struct sockaddr *)&sin6, 0);
#endif
		if (!rt || rt->rt_ifp != ifp) {
#if 0
			log(LOG_WARNING, "%s: packet from %s dropped "
			    "due to ingress filter\n", if_name(&sc->gif_if),
			    ip6_sprintf(&sin6.sin6_addr));
#endif
			if (rt)
				rtfree(rt);
			return 0;
		}
		rtfree(rt);
	}

	return 128 * 2;
}

/*
 * we know that we are in IFF_UP, outer address available, and outer family
 * matched the physical addr family.  see gif_encapcheck().
 */
int
gif_encapcheck6(m, off, proto, arg)
	const struct mbuf *m;
	int off;
	int proto;
	void *arg;
{
	struct ip6_hdr ip6;
	struct gif_softc *sc;
	struct ifnet *ifp;

	/* sanity check done in caller */
	sc = (struct gif_softc *)arg;

	/* LINTED const cast */
	m_copydata((struct mbuf *)m, 0, sizeof(ip6), (caddr_t)&ip6);
	ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;

	return gif_validate6(&ip6, sc, ifp);
}

int
in6_gif_attach(sc)
	struct gif_softc *sc;
{
#ifndef USE_ENCAPCHECK
	struct sockaddr_in6 mask6;

	bzero(&mask6, sizeof(mask6));
	mask6.sin6_len = sizeof(struct sockaddr_in6);
	mask6.sin6_addr.s6_addr32[0] = mask6.sin6_addr.s6_addr32[1] = 
	    mask6.sin6_addr.s6_addr32[2] = mask6.sin6_addr.s6_addr32[3] = ~0;

	if (!sc->gif_psrc || !sc->gif_pdst)
		return EINVAL;
	sc->encap_cookie6 = encap_attach(AF_INET6, -1, sc->gif_psrc,
	    (struct sockaddr *)&mask6, sc->gif_pdst, (struct sockaddr *)&mask6,
	    (struct protosw *)&in6_gif_protosw, sc);
#else
	sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
	    (struct protosw *)&in6_gif_protosw, sc);
#endif
	if (sc->encap_cookie6 == NULL)
		return EEXIST;
	return 0;
}

int
in6_gif_detach(sc)
	struct gif_softc *sc;
{
	int error;

	error = encap_detach(sc->encap_cookie6);
	if (error == 0)
		sc->encap_cookie6 = NULL;
	return error;
}

void
in6_gif_ctlinput(cmd, sa, d)
	int cmd;
	struct sockaddr *sa;
	void *d;
{
	struct gif_softc *sc;
	struct ip6ctlparam *ip6cp = NULL;
	struct mbuf *m;
	struct ip6_hdr *ip6;
	int off;
	void *cmdarg;
	const struct sockaddr_in6 *sa6_src = NULL;
	struct sockaddr_in6 *dst6;

	if (sa->sa_family != AF_INET6 ||
	    sa->sa_len != sizeof(struct sockaddr_in6))
		return;

	if ((unsigned)cmd >= PRC_NCMDS)
		return;
	if (cmd == PRC_HOSTDEAD)
		d = NULL;
	else if (inet6ctlerrmap[cmd] == 0)
		return;

	/* if the parameter is from icmp6, decode it. */
	if (d != NULL) {
		ip6cp = (struct ip6ctlparam *)d;
		m = ip6cp->ip6c_m;
		ip6 = ip6cp->ip6c_ip6;
		off = ip6cp->ip6c_off;
		cmdarg = ip6cp->ip6c_cmdarg;
		sa6_src = ip6cp->ip6c_src;
	} else {
		m = NULL;
		ip6 = NULL;
		cmdarg = NULL;
		sa6_src = &sa6_any;
	}

	if (!ip6)
		return;

	/*
	 * for now we don't care which type it was, just flush the route cache.
	 * XXX slow.  sc (or sc->encap_cookie6) should be passed from
	 * ip_encap.c.
	 */
	for (sc = LIST_FIRST(&gif_softc_list); sc;
	     sc = LIST_NEXT(sc, gif_list)) {
		if ((sc->gif_if.if_flags & IFF_RUNNING) == 0)
			continue;
		if (sc->gif_psrc->sa_family != AF_INET6)
			continue;
		if (!sc->gif_ro6.ro_rt)
			continue;

		dst6 = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
		/* XXX scope */
		if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst6->sin6_addr)) {
			/* flush route cache */
			RTFREE(sc->gif_ro6.ro_rt);
			sc->gif_ro6.ro_rt = NULL;
		}
	}
}