bring in KAME IPv6 code, dated 19991208.

replaces NRL IPv6 layer.  reuses NRL pcb layer.  no IPsec-on-v6 support.
see sys/netinet6/{TODO,IMPLEMENTATION} for more details.

GENERIC configuration should work fine as before.  GENERIC.v6 works fine
as well, but you'll need KAME userland tools to play with IPv6 (will be
bringed into soon).

1 files changed, 450 insertions, 0 deletions

diff --git a/sys/netinet6/ip6_forward.c b/sys/netinet6/ip6_forward.c
new file mode 100644
index 00000000000..df8b3879648
--- /dev/null
+++ b/sys/netinet6/ip6_forward.c
@@ -0,0 +1,450 @@
+/*	$OpenBSD: ip6_forward.c,v 1.1 1999/12/08 06:50:21 itojun Exp $	*/
+
+/*
+ * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if (defined(__FreeBSD__) && __FreeBSD__ >= 3)
+#include "opt_ip6fw.h"
+#include "opt_inet.h"
+#endif
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/domain.h>
+#include <sys/protosw.h>
+#include <sys/socket.h>
+#include <sys/errno.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+#include <sys/syslog.h>
+
+#include <net/if.h>
+#include <net/route.h>
+
+#include <netinet/in.h>
+#include <netinet/in_var.h>
+#include <netinet6/ip6.h>
+#include <netinet6/ip6_var.h>
+#include <netinet6/icmp6.h>
+#include <netinet6/nd6.h>
+
+#ifdef __OpenBSD__ /*KAME IPSEC*/
+#undef IPSEC
+#endif
+
+#ifdef IPSEC_IPV6FWD
+#include <netinet6/ipsec.h>
+#include <netkey/key.h>
+#include <netkey/key_debug.h>
+#endif /* IPSEC_IPV6FWD */
+
+#ifdef IPV6FIREWALL
+#include <netinet6/ip6_fw.h>
+#endif
+
+#include <net/net_osdep.h>
+
+struct	route_in6 ip6_forward_rt;
+
+/*
+ * Forward a packet.  If some error occurs return the sender
+ * an icmp packet.  Note we can't always generate a meaningful
+ * icmp message because icmp doesn't have a large enough repertoire
+ * of codes and types.
+ *
+ * If not forwarding, just drop the packet.  This could be confusing
+ * if ipforwarding was zero but some routing protocol was advancing
+ * us as a gateway to somewhere.  However, we must let the routing
+ * protocol deal with that.
+ *
+ */
+
+void
+ip6_forward(m, srcrt)
+	struct mbuf *m;
+	int srcrt;
+{
+	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
+	register struct sockaddr_in6 *dst;
+	register struct rtentry *rt;
+	int error, type = 0, code = 0;
+	struct mbuf *mcopy = NULL;
+#ifdef IPSEC_IPV6FWD
+	struct secpolicy *sp = NULL;
+#endif
+#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
+	long time_second = time.tv_sec;
+#endif
+
+#ifdef IPSEC_IPV6FWD
+	/*
+	 * Check AH/ESP integrity.
+	 */
+	/*
+	 * Don't increment ip6s_cantforward because this is the check
+	 * before forwarding packet actually.
+	 */
+	if (ipsec6_in_reject(m, NULL)) {
+		ipsec6stat.in_polvio++;
+		m_freem(m);
+		return;
+	}
+#endif /*IPSEC_IPV6FWD*/
+
+	if (m->m_flags & (M_BCAST|M_MCAST) ||
+	   in6_canforward(&ip6->ip6_src, &ip6->ip6_dst) == 0) {
+		ip6stat.ip6s_cantforward++;
+		ip6stat.ip6s_badscope++;
+		/* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */
+		if (ip6_log_time + ip6_log_interval < time_second) {
+			char addr[INET6_ADDRSTRLEN];
+			ip6_log_time = time_second;
+			strncpy(addr, ip6_sprintf(&ip6->ip6_src), sizeof(addr));
+			log(LOG_DEBUG,
+			    "cannot forward "
+			    "from %s to %s nxt %d received on %s\n",
+			    addr, ip6_sprintf(&ip6->ip6_dst),
+			    ip6->ip6_nxt,
+			    if_name(m->m_pkthdr.rcvif));
+		}
+		m_freem(m);
+		return;
+	}
+
+	if (ip6->ip6_hlim <= IPV6_HLIMDEC) {
+		/* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */
+		icmp6_error(m, ICMP6_TIME_EXCEEDED,
+				ICMP6_TIME_EXCEED_TRANSIT, 0);
+		return;
+	}
+	ip6->ip6_hlim -= IPV6_HLIMDEC;
+
+	/*
+	 * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU -
+	 * size of IPv6 + ICMPv6 headers) bytes of the packet in case
+	 * we need to generate an ICMP6 message to the src.
+	 * Thanks to M_EXT, in most cases copy will not occur.
+	 *
+	 * It is important to save it before IPsec processing as IPsec
+	 * processing may modify the mbuf.
+	 */
+	mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN));
+
+#ifdef IPSEC_IPV6FWD
+	/* get a security policy for this packet */
+	sp = ipsec6_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 0, &error);
+	if (sp == NULL) {
+		ipsec6stat.out_inval++;
+		ip6stat.ip6s_cantforward++;
+		if (mcopy) {
+#if 0
+			/* XXX: what icmp ? */
+#else
+			m_freem(mcopy);
+#endif
+		}
+		m_freem(m);
+		return;
+	}
+
+	error = 0;
+
+	/* check policy */
+	switch (sp->policy) {
+	case IPSEC_POLICY_DISCARD:
+		/*
+		 * This packet is just discarded.
+		 */
+		ipsec6stat.out_polvio++;
+		ip6stat.ip6s_cantforward++;
+		key_freesp(sp);
+		if (mcopy) {
+#if 0
+			/* XXX: what icmp ? */
+#else
+			m_freem(mcopy);
+#endif
+		}
+		m_freem(m);
+		return;
+
+	case IPSEC_POLICY_BYPASS:
+	case IPSEC_POLICY_NONE:
+		/* no need to do IPsec. */
+		key_freesp(sp);
+		goto skip_ipsec;
+	
+	case IPSEC_POLICY_IPSEC:
+		if (sp->req == NULL) {
+			/* XXX should be panic ? */
+			printf("ip6_forward: No IPsec request specified.\n");
+			ip6stat.ip6s_cantforward++;
+			key_freesp(sp);
+			if (mcopy) {
+#if 0
+				/* XXX: what icmp ? */
+#else
+				m_freem(mcopy);
+#endif
+			}
+			m_freem(m);
+			return;
+		}
+		/* do IPsec */
+		break;
+
+	case IPSEC_POLICY_ENTRUST:
+	default:
+		/* should be panic ?? */
+		printf("ip6_forward: Invalid policy found. %d\n", sp->policy);
+		key_freesp(sp);
+		goto skip_ipsec;
+	}
+
+    {
+	struct ipsec_output_state state;
+
+	/*
+	 * All the extension headers will become inaccessible
+	 * (since they can be encrypted).
+	 * Don't panic, we need no more updates to extension headers
+	 * on inner IPv6 packet (since they are now encapsulated).
+	 *
+	 * IPv6 [ESP|AH] IPv6 [extension headers] payload
+	 */
+	bzero(&state, sizeof(state));
+	state.m = m;
+	state.ro = NULL;	/* update at ipsec6_output_tunnel() */
+	state.dst = NULL;	/* update at ipsec6_output_tunnel() */
+
+	error = ipsec6_output_tunnel(&state, sp, 0);
+
+	m = state.m;
+#if 0	/* XXX allocate a route (ro, dst) again later */
+	ro = (struct route_in6 *)state.ro;
+	dst = (struct sockaddr_in6 *)state.dst;
+#endif
+	key_freesp(sp);
+
+	if (error) {
+		/* mbuf is already reclaimed in ipsec6_output_tunnel. */
+		switch (error) {
+		case EHOSTUNREACH:
+		case ENETUNREACH:
+		case EMSGSIZE:
+		case ENOBUFS:
+		case ENOMEM:
+			break;
+		default:
+			printf("ip6_output (ipsec): error code %d\n", error);
+			/*fall through*/
+		case ENOENT:
+			/* don't show these error codes to the user */
+			break;
+		}
+		ip6stat.ip6s_cantforward++;
+		if (mcopy) {
+#if 0
+			/* XXX: what icmp ? */
+#else
+			m_freem(mcopy);
+#endif
+		}
+		m_freem(m);
+		return;
+	}
+    }
+    skip_ipsec:
+#endif /* IPSEC_IPV6FWD */
+
+	dst = &ip6_forward_rt.ro_dst;
+	if (!srcrt) {
+		/*
+		 * ip6_forward_rt.ro_dst.sin6_addr is equal to ip6->ip6_dst
+		 */
+		if (ip6_forward_rt.ro_rt == 0 ||
+		    (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) == 0) {
+			if (ip6_forward_rt.ro_rt) {
+				RTFREE(ip6_forward_rt.ro_rt);
+				ip6_forward_rt.ro_rt = 0;
+			}
+			/* this probably fails but give it a try again */
+#ifdef __FreeBSD__
+			rtalloc_ign((struct route *)&ip6_forward_rt,
+				    RTF_PRCLONING);
+#else
+			rtalloc((struct route *)&ip6_forward_rt);
+#endif
+		}
+		
+		if (ip6_forward_rt.ro_rt == 0) {
+			ip6stat.ip6s_noroute++;
+			/* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_noroute) */
+			if (mcopy) {
+				icmp6_error(mcopy, ICMP6_DST_UNREACH,
+					    ICMP6_DST_UNREACH_NOROUTE, 0);
+			}
+			m_freem(m);
+			return;
+		}
+	} else if ((rt = ip6_forward_rt.ro_rt) == 0 ||
+		 !IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst->sin6_addr)) {
+		if (ip6_forward_rt.ro_rt) {
+			RTFREE(ip6_forward_rt.ro_rt);
+			ip6_forward_rt.ro_rt = 0;
+		}
+		bzero(dst, sizeof(*dst));
+		dst->sin6_len = sizeof(struct sockaddr_in6);
+		dst->sin6_family = AF_INET6;
+		dst->sin6_addr = ip6->ip6_dst;
+
+#ifdef __FreeBSD__
+  		rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING);
+#else
+		rtalloc((struct route *)&ip6_forward_rt);
+#endif
+		if (ip6_forward_rt.ro_rt == 0) {
+			ip6stat.ip6s_noroute++;
+			/* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_noroute) */
+			if (mcopy) {
+				icmp6_error(mcopy, ICMP6_DST_UNREACH,
+					    ICMP6_DST_UNREACH_NOROUTE, 0);
+			}
+			m_freem(m);
+			return;
+		}
+	}
+	rt = ip6_forward_rt.ro_rt;
+	if (m->m_pkthdr.len > rt->rt_ifp->if_mtu){
+		in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig);
+		if (mcopy) {
+			/*
+			 * XXX
+			 * When we do IPsec tunnel ingress, we need to play
+			 * with if_mtu value (decrement IPsec header size
+			 * from mtu value).  see ip_input().
+			 */
+			icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0,
+				rt->rt_ifp->if_mtu);
+		}
+		m_freem(m);
+		return;
+ 	}
+
+	if (rt->rt_flags & RTF_GATEWAY)
+		dst = (struct sockaddr_in6 *)rt->rt_gateway;
+
+	/*
+	 * If we are to forward the packet using the same interface
+	 * as one we got the packet from, perhaps we should send a redirect
+	 * to sender to shortcut a hop.
+	 * Only send redirect if source is sending directly to us,
+	 * and if packet was not source routed (or has any options).
+	 * Also, don't send redirect if forwarding using a route
+	 * modified by a redirect.
+	 */
+	if (rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt &&
+	    (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0)
+		type = ND_REDIRECT;
+
+#ifdef IPV6FIREWALL
+	/*
+	 * Check with the firewall...
+	 */
+	if (ip6_fw_chk_ptr) {
+		u_short port = 0;
+		/* If ipfw says divert, we have to just drop packet */
+		if ((*ip6_fw_chk_ptr)(&ip6, rt->rt_ifp, &port, &m)) {
+			m_freem(m);
+			goto freecopy;
+		}
+		if (!m)
+			goto freecopy;
+	}
+#endif
+
+#ifdef OLDIP6OUTPUT
+	error = (*rt->rt_ifp->if_output)(rt->rt_ifp, m,
+					 (struct sockaddr *)dst,
+					 ip6_forward_rt.ro_rt);
+#else
+	error = nd6_output(rt->rt_ifp, m, dst, rt);
+#endif 
+	if (error) {
+		in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard);
+		ip6stat.ip6s_cantforward++;
+	} else {
+		ip6stat.ip6s_forward++;
+		in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward);
+		if (type)
+			ip6stat.ip6s_redirectsent++;
+		else {
+			if (mcopy)
+				goto freecopy;
+		}
+	}
+	if (mcopy == NULL)
+		return;
+
+	switch (error) {
+	case 0:
+#if 1
+		if (type == ND_REDIRECT) {
+			icmp6_redirect_output(mcopy, rt);
+			return;
+		}
+#endif
+		goto freecopy;
+
+	case EMSGSIZE:
+		/* xxx MTU is constant in PPP? */
+		goto freecopy;
+
+	case ENOBUFS:
+		/* Tell source to slow down like source quench in IP? */
+		goto freecopy;
+
+	case ENETUNREACH:	/* shouldn't happen, checked above */
+	case EHOSTUNREACH:
+	case ENETDOWN:
+	case EHOSTDOWN:
+	default:
+		type = ICMP6_DST_UNREACH;
+		code = ICMP6_DST_UNREACH_ADDR;
+		break;
+	}
+	icmp6_error(mcopy, type, code, 0);
+	return;
+
+ freecopy:
+	m_freem(mcopy);
+	return;
+}