Add ip6fw.

Yes it is almost code freeze, but as the result of many thought, now I
think this should be added before 4.0...

make world check, kernel build check is done.

Reviewed by: green
Obtained from: KAME project

4 files changed, 1375 insertions, 0 deletions

diff --git a/sys/netinet6/ip6_fw.c b/sys/netinet6/ip6_fw.c
new file mode 100644
index 0000000..8fa5838
--- /dev/null
+++ b/sys/netinet6/ip6_fw.c
@@ -0,0 +1,1171 @@
+/*
+ * Copyright (c) 1993 Daniel Boulet
+ * Copyright (c) 1994 Ugen J.S.Antsilevich
+ * Copyright (c) 1996 Alex Nash
+ *
+ * Redistribution and use in source forms, with and without modification,
+ * are permitted provided that this entire comment appears intact.
+ *
+ * Redistribution in binary form may occur without any restrictions.
+ * Obviously, it would be nice if you gave credit where credit is due
+ * but requiring it would be too onerous.
+ *
+ * This software is provided ``AS IS'' without any warranties of any kind.
+ *
+ *	$Id: ip6_fw.c,v 1.7 1999/08/31 12:25:57 shin Exp $
+ * $FreeBSD$
+ */
+
+/*
+ * Implement IPv6 packet firewall
+ */
+
+#include "opt_ip6fw.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/queue.h>
+#include <sys/kernel.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/time.h>
+#include <net/if.h>
+#include <net/route.h>
+#include <netinet/in_systm.h>
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <netinet/in_pcb.h>
+#include <netinet6/in6_var.h>
+#include <netinet6/ip6.h>
+#include <netinet6/icmp6.h>
+#include <netinet6/ip6_fw.h>
+#include <netinet/ip_var.h>
+#include <netinet/tcp.h>
+#include <netinet/tcp_seq.h>
+#include <netinet/tcp_timer.h>
+#include <netinet/tcp_var.h>
+#include <netinet/udp.h>
+
+#include <sys/sysctl.h>
+
+#include <net/net_osdep.h>
+
+MALLOC_DEFINE(M_IP6FW, "Ip6Fw/Ip6Acct", "Ip6Fw/Ip6Acct chain's");
+
+static int fw6_debug = 1;
+#ifdef IPV6FIREWALL_VERBOSE
+static int fw6_verbose = 1;
+#else
+static int fw6_verbose = 0;
+#endif
+#ifdef IPV6FIREWALL_VERBOSE_LIMIT
+static int fw6_verbose_limit = IPV6FIREWALL_VERBOSE_LIMIT;
+#else
+static int fw6_verbose_limit = 0;
+#endif
+
+LIST_HEAD (ip6_fw_head, ip6_fw_chain) ip6_fw_chain;
+
+#ifdef SYSCTL_NODE
+SYSCTL_DECL(_net_inet6_ip6);
+SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
+SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, debug, CTLFLAG_RW, &fw6_debug, 0, "");
+SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, verbose, CTLFLAG_RW, &fw6_verbose, 0, "");
+SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, &fw6_verbose_limit, 0, "");
+#endif
+
+#define	dprintf(a)	if (!fw6_debug); else printf a
+
+#define	print_ip6(a)	printf("[%s]", ip6_sprintf(a))
+
+#define	dprint_ip6(a)	if (!fw6_debug); else print_ip6(a)
+
+static int	add_entry6 __P((struct ip6_fw_head *chainptr, struct ip6_fw *frwl));
+static int	del_entry6 __P((struct ip6_fw_head *chainptr, u_short number));
+static int	zero_entry6 __P((struct mbuf *m));
+static struct ip6_fw *check_ip6fw_struct __P((struct ip6_fw *m));
+static struct ip6_fw *check_ip6fw_mbuf __P((struct mbuf *fw));
+static int	ip6opts_match __P((struct ip6_hdr **ip6, struct ip6_fw *f,
+				   struct mbuf **m,
+				   int *off, int *nxt, u_short *offset));
+static int	port_match6 __P((u_short *portptr, int nports, u_short port,
+				int range_flag));
+static int	tcp6flg_match __P((struct tcphdr *tcp6, struct ip6_fw *f));
+static int	icmp6type_match __P((struct icmp6_hdr *  icmp, struct ip6_fw * f));
+static void	ip6fw_report __P((struct ip6_fw *f, struct ip6_hdr *ip6,
+				struct ifnet *rif, struct ifnet *oif, int off, int nxt));
+
+static int	ip6_fw_chk __P((struct ip6_hdr **pip6,
+			struct ifnet *oif, u_int16_t *cookie, struct mbuf **m));
+static int	ip6_fw_ctl __P((int stage, struct mbuf **mm));
+
+static char err_prefix[] = "ip6_fw_ctl:";
+
+/*
+ * Returns 1 if the port is matched by the vector, 0 otherwise
+ */
+static
+__inline int
+port_match6(u_short *portptr, int nports, u_short port, int range_flag)
+{
+	if (!nports)
+		return 1;
+	if (range_flag) {
+		if (portptr[0] <= port && port <= portptr[1]) {
+			return 1;
+		}
+		nports -= 2;
+		portptr += 2;
+	}
+	while (nports-- > 0) {
+		if (*portptr++ == port) {
+			return 1;
+		}
+	}
+	return 0;
+}
+
+static int
+tcp6flg_match(struct tcphdr *tcp6, struct ip6_fw *f)
+{
+	u_char		flg_set, flg_clr;
+
+	if ((f->fw_tcpf & IPV6_FW_TCPF_ESTAB) &&
+	    (tcp6->th_flags & (IPV6_FW_TCPF_RST | IPV6_FW_TCPF_ACK)))
+		return 1;
+
+	flg_set = tcp6->th_flags & f->fw_tcpf;
+	flg_clr = tcp6->th_flags & f->fw_tcpnf;
+
+	if (flg_set != f->fw_tcpf)
+		return 0;
+	if (flg_clr)
+		return 0;
+
+	return 1;
+}
+
+static int
+icmp6type_match(struct icmp6_hdr *icmp6, struct ip6_fw *f)
+{
+	int type;
+
+	if (!(f->fw_flg & IPV6_FW_F_ICMPBIT))
+		return(1);
+
+	type = icmp6->icmp6_type;
+
+	/* check for matching type in the bitmap */
+	if (type < IPV6_FW_ICMPTYPES_DIM * sizeof(unsigned) * 8 &&
+		(f->fw_icmp6types[type / (sizeof(unsigned) * 8)] &
+		(1U << (type % (8 * sizeof(unsigned))))))
+		return(1);
+
+	return(0); /* no match */
+}
+
+static int
+is_icmp6_query(struct ip6_hdr *ip6, int off)
+{
+	const struct icmp6_hdr *icmp6;
+	int icmp6_type;
+
+	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
+	icmp6_type = icmp6->icmp6_type;
+
+	if (icmp6_type == ICMP6_ECHO_REQUEST ||
+	    icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
+	    icmp6_type == ICMP6_WRUREQUEST ||
+	    icmp6_type == ICMP6_FQDN_QUERY ||
+	    icmp6_type == ICMP6_NI_QUERY)
+		return(1);
+
+	return(0);
+}
+
+static int
+ip6opts_match(struct ip6_hdr **pip6, struct ip6_fw *f, struct mbuf **m,
+	      int *off, int *nxt, u_short *offset)
+{
+	int len;
+	struct ip6_hdr *ip6 = *pip6;
+	struct ip6_ext *ip6e;
+	u_char	opts, nopts, nopts_sve;
+
+	opts = f->fw_ip6opt;
+	nopts = nopts_sve = f->fw_ip6nopt;
+
+	*nxt = ip6->ip6_nxt;
+	*off = sizeof(struct ip6_hdr);
+	len = ntohs(ip6->ip6_plen) + sizeof(struct ip6_hdr);
+	while (*off < len) {
+		ip6e = (struct ip6_ext *)((caddr_t) ip6 + *off);
+		if ((*m)->m_len < *off + sizeof(*ip6e))
+			goto opts_check;	/* XXX */
+
+		switch(*nxt) {
+		case IPPROTO_FRAGMENT:
+			if ((*m)->m_len < *off + sizeof(struct ip6_frag)) {
+				struct ip6_frag *ip6f;
+
+				ip6f = (struct ip6_frag *) ((caddr_t)ip6 + *off);
+				*offset = ip6f->ip6f_offlg | IP6F_OFF_MASK;
+			}
+			opts &= ~IPV6_FW_IP6OPT_FRAG;
+			nopts &= ~IPV6_FW_IP6OPT_FRAG;
+			*off += sizeof(struct ip6_frag);
+			break;
+		case IPPROTO_AH:
+			opts &= ~IPV6_FW_IP6OPT_AH;
+			nopts &= ~IPV6_FW_IP6OPT_AH;
+			*off += (ip6e->ip6e_len + 2) << 2;
+			break;
+		default:
+			switch (*nxt) {
+			case IPPROTO_HOPOPTS:
+				opts &= ~IPV6_FW_IP6OPT_HOPOPT;
+				nopts &= ~IPV6_FW_IP6OPT_HOPOPT;
+				break;
+			case IPPROTO_ROUTING:
+				opts &= ~IPV6_FW_IP6OPT_ROUTE;
+				nopts &= ~IPV6_FW_IP6OPT_ROUTE;
+				break;
+			case IPPROTO_ESP:
+				opts &= ~IPV6_FW_IP6OPT_ESP;
+				nopts &= ~IPV6_FW_IP6OPT_ESP;
+				break;
+			case IPPROTO_NONE:
+				opts &= ~IPV6_FW_IP6OPT_NONXT;
+				nopts &= ~IPV6_FW_IP6OPT_NONXT;
+				goto opts_check;
+				break;
+			case IPPROTO_DSTOPTS:
+				opts &= ~IPV6_FW_IP6OPT_OPTS;
+				nopts &= ~IPV6_FW_IP6OPT_OPTS;
+				break;
+			default:
+				goto opts_check;
+				break;
+			}
+			*off += (ip6e->ip6e_len + 1) << 3;
+			break;
+		}
+		*nxt = ip6e->ip6e_nxt;
+
+	}
+ opts_check:
+	if (f->fw_ip6opt == f->fw_ip6nopt)	/* XXX */
+		return 1;
+
+	if (opts == 0 && nopts == nopts_sve)
+		return 1;
+	else
+		return 0;
+}
+
+static
+__inline int
+iface_match(struct ifnet *ifp, union ip6_fw_if *ifu, int byname)
+{
+	/* Check by name or by IP address */
+	if (byname) {
+		/* Check unit number (-1 is wildcard) */
+		if (ifu->fu_via_if.unit != -1
+		    && ifp->if_unit != ifu->fu_via_if.unit)
+			return(0);
+		/* Check name */
+		if (strncmp(ifp->if_name, ifu->fu_via_if.name, FW_IFNLEN))
+			return(0);
+		return(1);
+	} else if (!IN6_IS_ADDR_UNSPECIFIED(&ifu->fu_via_ip6)) {	/* Zero == wildcard */
+		struct ifaddr *ia;
+
+		for (ia = ifp->if_addrlist.tqh_first; ia; ia = ia->ifa_list.tqe_next)
+		{
+
+			if (ia->ifa_addr == NULL)
+				continue;
+			if (ia->ifa_addr->sa_family != AF_INET6)
+				continue;
+			if (!IN6_ARE_ADDR_EQUAL(&ifu->fu_via_ip6,
+			    &(((struct sockaddr_in6 *)
+			    (ia->ifa_addr))->sin6_addr)))
+				continue;
+			return(1);
+		}
+		return(0);
+	}
+	return(1);
+}
+
+static void
+ip6fw_report(struct ip6_fw *f, struct ip6_hdr *ip6,
+	struct ifnet *rif, struct ifnet *oif, int off, int nxt)
+{
+	static int counter;
+	struct tcphdr *const tcp6 = (struct tcphdr *) ((caddr_t) ip6+ off);
+	struct udphdr *const udp = (struct udphdr *) ((caddr_t) ip6+ off);
+	struct icmp6_hdr *const icmp6 = (struct icmp6_hdr *) ((caddr_t) ip6+ off);
+	int count;
+
+	count = f ? f->fw_pcnt : ++counter;
+	if (fw6_verbose_limit != 0 && count > fw6_verbose_limit)
+		return;
+
+	/* Print command name */
+	printf("ip6fw: %d ", f ? f->fw_number : -1);
+	if (!f)
+		printf("Refuse");
+	else
+		switch (f->fw_flg & IPV6_FW_F_COMMAND) {
+		case IPV6_FW_F_DENY:
+			printf("Deny");
+			break;
+		case IPV6_FW_F_REJECT:
+			if (f->fw_reject_code == IPV6_FW_REJECT_RST)
+				printf("Reset");
+			else
+				printf("Unreach");
+			break;
+		case IPV6_FW_F_ACCEPT:
+			printf("Accept");
+			break;
+		case IPV6_FW_F_COUNT:
+			printf("Count");
+			break;
+		case IPV6_FW_F_DIVERT:
+			printf("Divert %d", f->fw_divert_port);
+			break;
+		case IPV6_FW_F_TEE:
+			printf("Tee %d", f->fw_divert_port);
+			break;
+		case IPV6_FW_F_SKIPTO:
+			printf("SkipTo %d", f->fw_skipto_rule);
+			break;
+		default:
+			printf("UNKNOWN");
+			break;
+		}
+	printf(" ");
+
+	switch (nxt) {
+	case IPPROTO_TCP:
+		printf("TCP ");
+		print_ip6(&ip6->ip6_src);
+		if (off > 0)
+			printf(":%d ", ntohs(tcp6->th_sport));
+		else
+			printf(" ");
+		print_ip6(&ip6->ip6_dst);
+		if (off > 0)
+			printf(":%d", ntohs(tcp6->th_dport));
+		break;
+	case IPPROTO_UDP:
+		printf("UDP ");
+		print_ip6(&ip6->ip6_src);
+		if (off > 0)
+			printf(":%d ", ntohs(udp->uh_sport));
+		else
+			printf(" ");
+		print_ip6(&ip6->ip6_dst);
+		if (off > 0)
+			printf(":%d", ntohs(udp->uh_dport));
+		break;
+	case IPPROTO_ICMPV6:
+		if (off > 0)
+			printf("IPV6-ICMP:%u.%u ", icmp6->icmp6_type, icmp6->icmp6_code);
+		else
+			printf("IPV6-ICMP ");
+		print_ip6(&ip6->ip6_src);
+		printf(" ");
+		print_ip6(&ip6->ip6_dst);
+		break;
+	default:
+		printf("P:%d ", nxt);
+		print_ip6(&ip6->ip6_src);
+		printf(" ");
+		print_ip6(&ip6->ip6_dst);
+		break;
+	}
+	if (oif)
+		printf(" out via %s", if_name(oif));
+	else if (rif)
+		printf(" in via %s", if_name(rif));
+	printf("\n");
+	if (fw6_verbose_limit != 0 && count == fw6_verbose_limit)
+		printf("ip6fw: limit reached on rule #%d\n",
+		f ? f->fw_number : -1);
+}
+
+/*
+ * Parameters:
+ *
+ *	ip	Pointer to packet header (struct ip6_hdr *)
+ *	hlen	Packet header length
+ *	oif	Outgoing interface, or NULL if packet is incoming
+ * #ifndef IP6FW_DIVERT_RESTART
+ *	*cookie	Ignore all divert/tee rules to this port (if non-zero)
+ * #else
+ *	*cookie Skip up to the first rule past this rule number;
+ * #endif
+ *	*m	The packet; we set to NULL when/if we nuke it.
+ *
+ * Return value:
+ *
+ *	0	The packet is to be accepted and routed normally OR
+ *      	the packet was denied/rejected and has been dropped;
+ *		in the latter case, *m is equal to NULL upon return.
+ *	port	Divert the packet to port.
+ */
+
+static int
+ip6_fw_chk(struct ip6_hdr **pip6,
+	struct ifnet *oif, u_int16_t *cookie, struct mbuf **m)
+{
+	struct ip6_fw_chain *chain;
+	struct ip6_fw *rule = NULL;
+	struct ip6_hdr *ip6 = *pip6;
+	struct ifnet *const rif = (*m)->m_pkthdr.rcvif;
+	u_short offset = 0;
+	int off = sizeof(struct ip6_hdr), nxt = ip6->ip6_nxt;
+	u_short src_port, dst_port;
+#ifdef	IP6FW_DIVERT_RESTART
+	u_int16_t skipto = *cookie;
+#else
+	u_int16_t ignport = ntohs(*cookie);
+#endif
+
+	*cookie = 0;
+	/*
+	 * Go down the chain, looking for enlightment
+	 * #ifdef IP6FW_DIVERT_RESTART
+	 * If we've been asked to start at a given rule immediatly, do so.
+	 * #endif
+	 */
+	chain = LIST_FIRST(&ip6_fw_chain);
+#ifdef IP6FW_DIVERT_RESTART
+	if (skipto) {
+		if (skipto >= 65535)
+			goto dropit;
+		while (chain && (chain->rule->fw_number <= skipto)) {
+			chain = LIST_NEXT(chain, chain);
+		}
+		if (! chain) goto dropit;
+	}
+#endif /* IP6FW_DIVERT_RESTART */
+	for (; chain; chain = LIST_NEXT(chain, chain)) {
+		register struct ip6_fw *const f = chain->rule;
+
+		if (oif) {
+			/* Check direction outbound */
+			if (!(f->fw_flg & IPV6_FW_F_OUT))
+				continue;
+		} else {
+			/* Check direction inbound */
+			if (!(f->fw_flg & IPV6_FW_F_IN))
+				continue;
+		}
+
+#define	IN6_ARE_ADDR_MASKEQUAL(x,y,z) (\
+	(((x)->s6_addr32[0] & (y)->s6_addr32[0]) == (z)->s6_addr32[0]) && \
+	(((x)->s6_addr32[1] & (y)->s6_addr32[1]) == (z)->s6_addr32[1]) && \
+	(((x)->s6_addr32[2] & (y)->s6_addr32[2]) == (z)->s6_addr32[2]) && \
+	(((x)->s6_addr32[3] & (y)->s6_addr32[3]) == (z)->s6_addr32[3]))
+
+		/* If src-addr doesn't match, not this rule. */
+		if (((f->fw_flg & IPV6_FW_F_INVSRC) != 0) ^
+			(!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_src,&f->fw_smsk,&f->fw_src)))
+			continue;
+
+		/* If dest-addr doesn't match, not this rule. */
+		if (((f->fw_flg & IPV6_FW_F_INVDST) != 0) ^
+			(!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_dst,&f->fw_dmsk,&f->fw_dst)))
+			continue;
+
+#undef IN6_ARE_ADDR_MASKEQUAL
+		/* Interface check */
+		if ((f->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
+			struct ifnet *const iface = oif ? oif : rif;
+
+			/* Backwards compatibility hack for "via" */
+			if (!iface || !iface_match(iface,
+			    &f->fw_in_if, f->fw_flg & IPV6_FW_F_OIFNAME))
+				continue;
+		} else {
+			/* Check receive interface */
+			if ((f->fw_flg & IPV6_FW_F_IIFACE)
+			    && (!rif || !iface_match(rif,
+			      &f->fw_in_if, f->fw_flg & IPV6_FW_F_IIFNAME)))
+				continue;
+			/* Check outgoing interface */
+			if ((f->fw_flg & IPV6_FW_F_OIFACE)
+			    && (!oif || !iface_match(oif,
+			      &f->fw_out_if, f->fw_flg & IPV6_FW_F_OIFNAME)))
+				continue;
+		}
+
+		/* Check IP options */
+		if (!ip6opts_match(&ip6, f, m, &off, &nxt, &offset))
+			continue;
+
+		/* Fragments */
+		if ((f->fw_flg & IPV6_FW_F_FRAG) && !offset)
+			continue;
+
+		/* Check protocol; if wildcard, match */
+		if (f->fw_prot == IPPROTO_IPV6)
+			goto got_match;
+
+		/* If different, don't match */
+		if (nxt != f->fw_prot)
+			continue;
+
+#define	PULLUP_TO(len)	do {						\
+			    if ((*m)->m_len < (len)			\
+				&& (*m = m_pullup(*m, (len))) == 0) {	\
+				    goto dropit;			\
+			    }						\
+			    *pip6 = ip6 = mtod(*m, struct ip6_hdr *);	\
+			} while (0)
+
+		/* Protocol specific checks */
+		switch (nxt) {
+		case IPPROTO_TCP:
+		    {
+			struct tcphdr *tcp6;
+
+			if (offset == 1) {	/* cf. RFC 1858 */
+				PULLUP_TO(off + 4); /* XXX ? */
+				goto bogusfrag;
+			}
+			if (offset != 0) {
+				/*
+				 * TCP flags and ports aren't available in this
+				 * packet -- if this rule specified either one,
+				 * we consider the rule a non-match.
+				 */
+				if (f->fw_nports != 0 ||
+				    f->fw_tcpf != f->fw_tcpnf)
+					continue;
+
+				break;
+			}
+			PULLUP_TO(off + 14);
+			tcp6 = (struct tcphdr *) ((caddr_t)ip6 + off);
+			if (f->fw_tcpf != f->fw_tcpnf && !tcp6flg_match(tcp6, f))
+				continue;
+			src_port = ntohs(tcp6->th_sport);
+			dst_port = ntohs(tcp6->th_dport);
+			goto check_ports;
+		    }
+
+		case IPPROTO_UDP:
+		    {
+			struct udphdr *udp;
+
+			if (offset != 0) {
+				/*
+				 * Port specification is unavailable -- if this
+				 * rule specifies a port, we consider the rule
+				 * a non-match.
+				 */
+				if (f->fw_nports != 0)
+					continue;
+
+				break;
+			}
+			PULLUP_TO(off + 4);
+			udp = (struct udphdr *) ((caddr_t)ip6 + off);
+			src_port = ntohs(udp->uh_sport);
+			dst_port = ntohs(udp->uh_dport);
+check_ports:
+			if (!port_match6(&f->fw_pts[0],
+			    IPV6_FW_GETNSRCP(f), src_port,
+			    f->fw_flg & IPV6_FW_F_SRNG))
+				continue;
+			if (!port_match6(&f->fw_pts[IPV6_FW_GETNSRCP(f)],
+			    IPV6_FW_GETNDSTP(f), dst_port,
+			    f->fw_flg & IPV6_FW_F_DRNG))
+				continue;
+			break;
+		    }
+
+		case IPPROTO_ICMPV6:
+		    {
+			struct icmp6_hdr *icmp;
+
+			if (offset != 0)	/* Type isn't valid */
+				break;
+			PULLUP_TO(off + 2);
+			icmp = (struct icmp6_hdr *) ((caddr_t)ip6 + off);
+			if (!icmp6type_match(icmp, f))
+				continue;
+			break;
+		    }
+#undef PULLUP_TO
+
+bogusfrag:
+			if (fw6_verbose)
+				ip6fw_report(NULL, ip6, rif, oif, off, nxt);
+			goto dropit;
+		}
+
+got_match:
+#ifndef IP6FW_DIVERT_RESTART
+		/* Ignore divert/tee rule if socket port is "ignport" */
+		switch (f->fw_flg & IPV6_FW_F_COMMAND) {
+		case IPV6_FW_F_DIVERT:
+		case IPV6_FW_F_TEE:
+			if (f->fw_divert_port == ignport)
+				continue;       /* ignore this rule */
+			break;
+		}
+
+#endif /* IP6FW_DIVERT_RESTART */
+		/* Update statistics */
+		f->fw_pcnt += 1;
+		f->fw_bcnt += ntohs(ip6->ip6_plen);
+		f->timestamp = time_second;
+
+		/* Log to console if desired */
+		if ((f->fw_flg & IPV6_FW_F_PRN) && fw6_verbose)
+			ip6fw_report(f, ip6, rif, oif, off, nxt);
+
+		/* Take appropriate action */
+		switch (f->fw_flg & IPV6_FW_F_COMMAND) {
+		case IPV6_FW_F_ACCEPT:
+			return(0);
+		case IPV6_FW_F_COUNT:
+			continue;
+		case IPV6_FW_F_DIVERT:
+#ifdef IP6FW_DIVERT_RESTART
+			*cookie = f->fw_number;
+#else
+			*cookie = htons(f->fw_divert_port);
+#endif /* IP6FW_DIVERT_RESTART */
+			return(f->fw_divert_port);
+		case IPV6_FW_F_TEE:
+			/*
+			 * XXX someday tee packet here, but beware that you
+			 * can't use m_copym() or m_copypacket() because
+			 * the divert input routine modifies the mbuf
+			 * (and these routines only increment reference
+			 * counts in the case of mbuf clusters), so need
+			 * to write custom routine.
+			 */
+			continue;
+		case IPV6_FW_F_SKIPTO:
+#ifdef DIAGNOSTIC
+			while (chain->chain.le_next
+			    && chain->chain.le_next->rule->fw_number
+				< f->fw_skipto_rule)
+#else
+			while (chain->chain.le_next->rule->fw_number
+			    < f->fw_skipto_rule)
+#endif
+				chain = chain->chain.le_next;
+			continue;
+		}
+
+		/* Deny/reject this packet using this rule */
+		rule = f;
+		break;
+	}
+
+#ifdef DIAGNOSTIC
+	/* Rule 65535 should always be there and should always match */
+	if (!chain)
+		panic("ip6_fw: chain");
+#endif
+
+	/*
+	 * At this point, we're going to drop the packet.
+	 * Send a reject notice if all of the following are true:
+	 *
+	 * - The packet matched a reject rule
+	 * - The packet is not an ICMP packet, or is an ICMP query packet
+	 * - The packet is not a multicast or broadcast packet
+	 */
+	if ((rule->fw_flg & IPV6_FW_F_COMMAND) == IPV6_FW_F_REJECT
+	    && (nxt != IPPROTO_ICMPV6 || is_icmp6_query(ip6, off))
+	    && !((*m)->m_flags & (M_BCAST|M_MCAST))
+	    && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
+		switch (rule->fw_reject_code) {
+		case IPV6_FW_REJECT_RST:
+		  {
+			struct tcphdr *const tcp =
+				(struct tcphdr *) ((caddr_t)ip6 + off);
+			struct {
+				struct ip6_hdr ip6;
+				struct tcphdr th;
+			} ti;
+			tcp_seq ack, seq;
+			int flags;
+
+			if (offset != 0 || (tcp->th_flags & TH_RST))
+				break;
+
+			ti.ip6 = *ip6;
+			ti.th = *tcp;
+			NTOHL(ti.th.th_seq);
+			NTOHL(ti.th.th_ack);
+			ti.ip6.ip6_nxt = IPPROTO_TCP;
+			if (ti.th.th_flags & TH_ACK) {
+				ack = 0;
+				seq = ti.th.th_ack;
+				flags = TH_RST;
+			} else {
+				ack = ti.th.th_seq;
+				if (((*m)->m_flags & M_PKTHDR) != 0) {
+					ack += (*m)->m_pkthdr.len - off
+						- (ti.th.th_off << 2);
+				} else if (ip6->ip6_plen) {
+					ack += ntohs(ip6->ip6_plen) + sizeof(*ip6)
+						- off - (ti.th.th_off << 2);
+				} else {
+					m_freem(*m);
+					*m = 0;
+					break;
+				}
+				seq = 0;
+				flags = TH_RST|TH_ACK;
+			}
+			bcopy(&ti, ip6, sizeof(ti));
+			m_freem(*m);
+			*m = NULL;
+			break;
+		  }
+		default:	/* Send an ICMP unreachable using code */
+			icmp6_error(*m, ICMP6_DST_UNREACH,
+			    rule->fw_reject_code, 0);
+			*m = NULL;
+			break;
+		}
+	}
+
+dropit:
+	/*
+	 * Finally, drop the packet.
+	 */
+	if (*m) {
+		m_freem(*m);
+		*m = NULL;
+	}
+	return(0);
+}
+
+static int
+add_entry6(struct ip6_fw_head *chainptr, struct ip6_fw *frwl)
+{
+	struct ip6_fw *ftmp = 0;
+	struct ip6_fw_chain *fwc = 0, *fcp, *fcpl = 0;
+	u_short nbr = 0;
+	int s;
+
+	fwc = malloc(sizeof *fwc, M_IP6FW, M_DONTWAIT);
+	ftmp = malloc(sizeof *ftmp, M_IP6FW, M_DONTWAIT);
+	if (!fwc || !ftmp) {
+		dprintf(("%s malloc said no\n", err_prefix));
+		if (fwc)  free(fwc, M_IP6FW);
+		if (ftmp) free(ftmp, M_IP6FW);
+		return (ENOSPC);
+	}
+
+	bcopy(frwl, ftmp, sizeof(struct ip6_fw));
+	ftmp->fw_in_if.fu_via_if.name[FW_IFNLEN - 1] = '\0';
+	ftmp->fw_pcnt = 0L;
+	ftmp->fw_bcnt = 0L;
+	fwc->rule = ftmp;
+
+	s = splnet();
+
+	if (!chainptr->lh_first) {
+		LIST_INSERT_HEAD(chainptr, fwc, chain);
+		splx(s);
+		return(0);
+        } else if (ftmp->fw_number == (u_short)-1) {
+		if (fwc)  free(fwc, M_IP6FW);
+		if (ftmp) free(ftmp, M_IP6FW);
+		splx(s);
+		dprintf(("%s bad rule number\n", err_prefix));
+		return (EINVAL);
+        }
+
+	/* If entry number is 0, find highest numbered rule and add 100 */
+	if (ftmp->fw_number == 0) {
+		for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
+			if (fcp->rule->fw_number != (u_short)-1)
+				nbr = fcp->rule->fw_number;
+			else
+				break;
+		}
+		if (nbr < (u_short)-1 - 100)
+			nbr += 100;
+		ftmp->fw_number = nbr;
+	}
+
+	/* Got a valid number; now insert it, keeping the list ordered */
+	for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
+		if (fcp->rule->fw_number > ftmp->fw_number) {
+			if (fcpl) {
+				LIST_INSERT_AFTER(fcpl, fwc, chain);
+			} else {
+				LIST_INSERT_HEAD(chainptr, fwc, chain);
+			}
+			break;
+		} else {
+			fcpl = fcp;
+		}
+	}
+
+	splx(s);
+	return (0);
+}
+
+static int
+del_entry6(struct ip6_fw_head *chainptr, u_short number)
+{
+	struct ip6_fw_chain *fcp;
+	int s;
+
+	s = splnet();
+
+	fcp = chainptr->lh_first;
+	if (number != (u_short)-1) {
+		for (; fcp; fcp = fcp->chain.le_next) {
+			if (fcp->rule->fw_number == number) {
+				LIST_REMOVE(fcp, chain);
+				splx(s);
+				free(fcp->rule, M_IP6FW);
+				free(fcp, M_IP6FW);
+				return 0;
+			}
+		}
+	}
+
+	splx(s);
+	return (EINVAL);
+}
+
+static int
+zero_entry6(struct mbuf *m)
+{
+	struct ip6_fw *frwl;
+	struct ip6_fw_chain *fcp;
+	int s;
+
+	if (m) {
+		if (m->m_len != sizeof(struct ip6_fw))
+			return(EINVAL);
+		frwl = mtod(m, struct ip6_fw *);
+	}
+	else
+		frwl = NULL;
+
+	/*
+	 *	It's possible to insert multiple chain entries with the
+	 *	same number, so we don't stop after finding the first
+	 *	match if zeroing a specific entry.
+	 */
+	s = splnet();
+	for (fcp = ip6_fw_chain.lh_first; fcp; fcp = fcp->chain.le_next)
+		if (!frwl || frwl->fw_number == fcp->rule->fw_number) {
+			fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0;
+			fcp->rule->timestamp = 0;
+		}
+	splx(s);
+
+	if (fw6_verbose) {
+		if (frwl)
+			printf("ip6fw: Entry %d cleared.\n", frwl->fw_number);
+		else
+			printf("ip6fw: Accounting cleared.\n");
+	}
+
+	return(0);
+}
+
+static struct ip6_fw *
+check_ip6fw_mbuf(struct mbuf *m)
+{
+	/* Check length */
+	if (m->m_len != sizeof(struct ip6_fw)) {
+		dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
+		    sizeof(struct ip6_fw)));
+		return (NULL);
+	}
+	return(check_ip6fw_struct(mtod(m, struct ip6_fw *)));
+}
+
+static struct ip6_fw *
+check_ip6fw_struct(struct ip6_fw *frwl)
+{
+	/* Check for invalid flag bits */
+	if ((frwl->fw_flg & ~IPV6_FW_F_MASK) != 0) {
+		dprintf(("%s undefined flag bits set (flags=%x)\n",
+		    err_prefix, frwl->fw_flg));
+		return (NULL);
+	}
+	/* Must apply to incoming or outgoing (or both) */
+	if (!(frwl->fw_flg & (IPV6_FW_F_IN | IPV6_FW_F_OUT))) {
+		dprintf(("%s neither in nor out\n", err_prefix));
+		return (NULL);
+	}
+	/* Empty interface name is no good */
+	if (((frwl->fw_flg & IPV6_FW_F_IIFNAME)
+	      && !*frwl->fw_in_if.fu_via_if.name)
+	    || ((frwl->fw_flg & IPV6_FW_F_OIFNAME)
+	      && !*frwl->fw_out_if.fu_via_if.name)) {
+		dprintf(("%s empty interface name\n", err_prefix));
+		return (NULL);
+	}
+	/* Sanity check interface matching */
+	if ((frwl->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
+		;		/* allow "via" backwards compatibility */
+	} else if ((frwl->fw_flg & IPV6_FW_F_IN)
+	    && (frwl->fw_flg & IPV6_FW_F_OIFACE)) {
+		dprintf(("%s outgoing interface check on incoming\n",
+		    err_prefix));
+		return (NULL);
+	}
+	/* Sanity check port ranges */
+	if ((frwl->fw_flg & IPV6_FW_F_SRNG) && IPV6_FW_GETNSRCP(frwl) < 2) {
+		dprintf(("%s src range set but n_src_p=%d\n",
+		    err_prefix, IPV6_FW_GETNSRCP(frwl)));
+		return (NULL);
+	}
+	if ((frwl->fw_flg & IPV6_FW_F_DRNG) && IPV6_FW_GETNDSTP(frwl) < 2) {
+		dprintf(("%s dst range set but n_dst_p=%d\n",
+		    err_prefix, IPV6_FW_GETNDSTP(frwl)));
+		return (NULL);
+	}
+	if (IPV6_FW_GETNSRCP(frwl) + IPV6_FW_GETNDSTP(frwl) > IPV6_FW_MAX_PORTS) {
+		dprintf(("%s too many ports (%d+%d)\n",
+		    err_prefix, IPV6_FW_GETNSRCP(frwl), IPV6_FW_GETNDSTP(frwl)));
+		return (NULL);
+	}
+	/*
+	 *	Protocols other than TCP/UDP don't use port range
+	 */
+	if ((frwl->fw_prot != IPPROTO_TCP) &&
+	    (frwl->fw_prot != IPPROTO_UDP) &&
+	    (IPV6_FW_GETNSRCP(frwl) || IPV6_FW_GETNDSTP(frwl))) {
+		dprintf(("%s port(s) specified for non TCP/UDP rule\n",
+		    err_prefix));
+		return(NULL);
+	}
+
+	/*
+	 *	Rather than modify the entry to make such entries work,
+	 *	we reject this rule and require user level utilities
+	 *	to enforce whatever policy they deem appropriate.
+	 */
+	if ((frwl->fw_src.s6_addr32[0] & (~frwl->fw_smsk.s6_addr32[0])) ||
+		(frwl->fw_src.s6_addr32[1] & (~frwl->fw_smsk.s6_addr32[1])) ||
+		(frwl->fw_src.s6_addr32[2] & (~frwl->fw_smsk.s6_addr32[2])) ||
+		(frwl->fw_src.s6_addr32[3] & (~frwl->fw_smsk.s6_addr32[3])) ||
+		(frwl->fw_dst.s6_addr32[0] & (~frwl->fw_dmsk.s6_addr32[0])) ||
+		(frwl->fw_dst.s6_addr32[1] & (~frwl->fw_dmsk.s6_addr32[1])) ||
+		(frwl->fw_dst.s6_addr32[2] & (~frwl->fw_dmsk.s6_addr32[2])) ||
+		(frwl->fw_dst.s6_addr32[3] & (~frwl->fw_dmsk.s6_addr32[3]))) {
+		dprintf(("%s rule never matches\n", err_prefix));
+		return(NULL);
+	}
+
+	if ((frwl->fw_flg & IPV6_FW_F_FRAG) &&
+		(frwl->fw_prot == IPPROTO_UDP || frwl->fw_prot == IPPROTO_TCP)) {
+		if (frwl->fw_nports) {
+			dprintf(("%s cannot mix 'frag' and ports\n", err_prefix));
+			return(NULL);
+		}
+		if (frwl->fw_prot == IPPROTO_TCP &&
+			frwl->fw_tcpf != frwl->fw_tcpnf) {
+			dprintf(("%s cannot mix 'frag' with TCP flags\n", err_prefix));
+			return(NULL);
+		}
+	}
+
+	/* Check command specific stuff */
+	switch (frwl->fw_flg & IPV6_FW_F_COMMAND)
+	{
+	case IPV6_FW_F_REJECT:
+		if (frwl->fw_reject_code >= 0x100
+		    && !(frwl->fw_prot == IPPROTO_TCP
+		      && frwl->fw_reject_code == IPV6_FW_REJECT_RST)) {
+			dprintf(("%s unknown reject code\n", err_prefix));
+			return(NULL);
+		}
+		break;
+	case IPV6_FW_F_DIVERT:		/* Diverting to port zero is invalid */
+	case IPV6_FW_F_TEE:
+		if (frwl->fw_divert_port == 0) {
+			dprintf(("%s can't divert to port 0\n", err_prefix));
+			return (NULL);
+		}
+		break;
+	case IPV6_FW_F_DENY:
+	case IPV6_FW_F_ACCEPT:
+	case IPV6_FW_F_COUNT:
+	case IPV6_FW_F_SKIPTO:
+		break;
+	default:
+		dprintf(("%s invalid command\n", err_prefix));
+		return(NULL);
+	}
+
+	return frwl;
+}
+
+static int
+ip6_fw_ctl(int stage, struct mbuf **mm)
+{
+	int error;
+	struct mbuf *m;
+
+	if (stage == IPV6_FW_GET) {
+		struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
+		*mm = m = m_get(M_WAIT, MT_DATA); /* XXX */
+		if (!m)
+			return(ENOBUFS);
+		if (sizeof *(fcp->rule) > MLEN) {
+			MCLGET(m, M_WAIT);
+			if ((m->m_flags & M_EXT) == 0) {
+				m_free(m);
+				return(ENOBUFS);
+			}
+		}
+		for (; fcp; fcp = fcp->chain.le_next) {
+			memcpy(m->m_data, fcp->rule, sizeof *(fcp->rule));
+			m->m_len = sizeof *(fcp->rule);
+			m->m_next = m_get(M_WAIT, MT_DATA); /* XXX */
+			if (!m->m_next) {
+				m_freem(*mm);
+				return(ENOBUFS);
+			}
+			m = m->m_next;
+			if (sizeof *(fcp->rule) > MLEN) {
+				MCLGET(m, M_WAIT);
+				if ((m->m_flags & M_EXT) == 0) {
+					m_freem(*mm);
+					return(ENOBUFS);
+				}
+			}
+			m->m_len = 0;
+		}
+		return (0);
+	}
+	m = *mm;
+	/* only allow get calls if secure mode > 2 */
+	if (securelevel > 2) {
+		if (m) {
+			(void)m_freem(m);
+			*mm = 0;
+		}
+		return(EPERM);
+	}
+	if (stage == IPV6_FW_FLUSH) {
+		while (ip6_fw_chain.lh_first != NULL &&
+		    ip6_fw_chain.lh_first->rule->fw_number != (u_short)-1) {
+			struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
+			int s = splnet();
+			LIST_REMOVE(ip6_fw_chain.lh_first, chain);
+			splx(s);
+			free(fcp->rule, M_IP6FW);
+			free(fcp, M_IP6FW);
+		}
+		if (m) {
+			(void)m_freem(m);
+			*mm = 0;
+		}
+		return (0);
+	}
+	if (stage == IPV6_FW_ZERO) {
+		error = zero_entry6(m);
+		if (m) {
+			(void)m_freem(m);
+			*mm = 0;
+		}
+		return (error);
+	}
+	if (m == NULL) {
+		printf("%s NULL mbuf ptr\n", err_prefix);
+		return (EINVAL);
+	}
+
+	if (stage == IPV6_FW_ADD) {
+		struct ip6_fw *frwl = check_ip6fw_mbuf(m);
+
+		if (!frwl)
+			error = EINVAL;
+		else
+			error = add_entry6(&ip6_fw_chain, frwl);
+		if (m) {
+			(void)m_freem(m);
+			*mm = 0;
+		}
+		return error;
+	}
+	if (stage == IPV6_FW_DEL) {
+		if (m->m_len != sizeof(struct ip6_fw)) {
+			dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
+			    sizeof(struct ip6_fw)));
+			error = EINVAL;
+		} else if (mtod(m, struct ip6_fw *)->fw_number == (u_short)-1) {
+			dprintf(("%s can't delete rule 65535\n", err_prefix));
+			error = EINVAL;
+		} else
+			error = del_entry6(&ip6_fw_chain,
+			    mtod(m, struct ip6_fw *)->fw_number);
+		if (m) {
+			(void)m_freem(m);
+			*mm = 0;
+		}
+		return error;
+	}
+
+	dprintf(("%s unknown request %d\n", err_prefix, stage));
+	if (m) {
+		(void)m_freem(m);
+		*mm = 0;
+	}
+	return (EINVAL);
+}
+
+void
+ip6_fw_init(void)
+{
+	struct ip6_fw default_rule;
+
+	ip6_fw_chk_ptr = ip6_fw_chk;
+	ip6_fw_ctl_ptr = ip6_fw_ctl;
+	LIST_INIT(&ip6_fw_chain);
+
+	bzero(&default_rule, sizeof default_rule);
+	default_rule.fw_prot = IPPROTO_IPV6;
+	default_rule.fw_number = (u_short)-1;
+#ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
+	default_rule.fw_flg |= IPV6_FW_F_ACCEPT;
+#else
+	default_rule.fw_flg |= IPV6_FW_F_DENY;
+#endif
+	default_rule.fw_flg |= IPV6_FW_F_IN | IPV6_FW_F_OUT;
+	if (check_ip6fw_struct(&default_rule) == NULL ||
+		add_entry6(&ip6_fw_chain, &default_rule))
+		panic(__FUNCTION__);
+
+	printf("IPv6 packet filtering initialized, ");
+#ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
+	printf("default to accept, ");
+#endif
+#ifndef IPV6FIREWALL_VERBOSE
+	printf("logging disabled\n");
+#else
+	if (fw6_verbose_limit == 0)
+		printf("unlimited logging\n");
+	else
+		printf("logging limited to %d packets/entry\n",
+		    fw6_verbose_limit);
+#endif
+}
diff --git a/sys/netinet6/ip6_fw.h b/sys/netinet6/ip6_fw.h
new file mode 100644
index 0000000..a356ac3
--- /dev/null
+++ b/sys/netinet6/ip6_fw.h
@@ -0,0 +1,202 @@
+/*
+ * Copyright (c) 1993 Daniel Boulet
+ * Copyright (c) 1994 Ugen J.S.Antsilevich
+ *
+ * Redistribution and use in source forms, with and without modification,
+ * are permitted provided that this entire comment appears intact.
+ *
+ * Redistribution in binary form may occur without any restrictions.
+ * Obviously, it would be nice if you gave credit where credit is due
+ * but requiring it would be too onerous.
+ *
+ * This software is provided ``AS IS'' without any warranties of any kind.
+ *
+ *	$Id: ip6_fw.h,v 1.1 1999/08/06 14:10:09 itojun Exp $
+ * $FreeBSD$
+ */
+
+#ifndef _IP6_FW_H
+#define _IP6_FW_H
+
+#include <net/if.h>
+
+/*
+ * This union structure identifies an interface, either explicitly
+ * by name or implicitly by IP address. The flags IP_FW_F_IIFNAME
+ * and IP_FW_F_OIFNAME say how to interpret this structure. An
+ * interface unit number of -1 matches any unit number, while an
+ * IP address of 0.0.0.0 indicates matches any interface.
+ *
+ * The receive and transmit interfaces are only compared against the
+ * the packet if the corresponding bit (IP_FW_F_IIFACE or IP_FW_F_OIFACE)
+ * is set. Note some packets lack a receive or transmit interface
+ * (in which case the missing "interface" never matches).
+ */
+
+union ip6_fw_if {
+	struct	in6_addr fu_via_ip6;	/* Specified by IPv6 address */
+	struct {			/* Specified by interface name */
+#define FW_IFNLEN     IFNAMSIZ
+		char	name[FW_IFNLEN];
+		short	unit;		/* -1 means match any unit */
+    } fu_via_if;
+};
+
+/*
+ * Format of an IP firewall descriptor
+ *
+ * fw_src, fw_dst, fw_smsk, fw_dmsk are always stored in network byte order.
+ * fw_flg and fw_n*p are stored in host byte order (of course).
+ * Port numbers are stored in HOST byte order.
+ * Warning: setsockopt() will fail if sizeof(struct ip_fw) > MLEN (108)
+ */
+
+struct ip6_fw {
+	u_long	fw_pcnt,fw_bcnt;		/* Packet and byte counters */
+	struct	in6_addr fw_src, fw_dst; /* Source and destination IPv6 addr */
+	/* Mask for src and dest IPv6 addr */
+	struct	in6_addr fw_smsk, fw_dmsk;
+	u_short	fw_number;			/* Rule number */
+	u_short	fw_flg;				/* Flags word */
+#define	IPV6_FW_MAX_PORTS	10		/* A reasonable maximum */
+	/* Array of port numbers to match */
+	u_short	fw_pts[IPV6_FW_MAX_PORTS];
+	u_char	fw_ip6opt,fw_ip6nopt;		/* IPv6 options set/unset */
+	u_char	fw_tcpf,fw_tcpnf;		/* TCP flags set/unset */
+#define	IPV6_FW_ICMPTYPES_DIM (32 / (sizeof(unsigned) * 8))
+	/* ICMP types bitmap */
+	unsigned	fw_icmp6types[IPV6_FW_ICMPTYPES_DIM];
+	long	timestamp;		/* timestamp (tv_sec) of last match */
+	/* Incoming and outgoing interfaces */
+	union	ip6_fw_if fw_in_if, fw_out_if;
+	union {
+		u_short	fu_divert_port;		/* Divert/tee port (options IP6DIVERT) */
+		u_short	fu_skipto_rule;		/* SKIPTO command rule number */
+		u_short	fu_reject_code;		/* REJECT response code */
+	} fw_un;
+	u_char	fw_prot;			/* IPv6 protocol */
+	u_char	fw_nports;	/* N'of src ports and # of dst ports */
+				/* in ports array (dst ports follow */
+				/* src ports; max of 10 ports in all; */
+				/* count of 0 means match all ports) */
+};
+
+#define	IPV6_FW_GETNSRCP(rule)		((rule)->fw_nports & 0x0f)
+#define	IPV6_FW_SETNSRCP(rule, n)		do {			\
+					  (rule)->fw_nports &= ~0x0f;	\
+					  (rule)->fw_nports |= (n);	\
+					} while (0)
+#define	IPV6_FW_GETNDSTP(rule)		((rule)->fw_nports >> 4)
+#define	IPV6_FW_SETNDSTP(rule, n)		do {			\
+					  (rule)->fw_nports &= ~0xf0;	\
+					  (rule)->fw_nports |= (n) << 4;\
+					} while (0)
+
+#define	fw_divert_port	fw_un.fu_divert_port
+#define	fw_skipto_rule	fw_un.fu_skipto_rule
+#define	fw_reject_code	fw_un.fu_reject_code
+
+struct	ip6_fw_chain {
+	LIST_ENTRY(ip6_fw_chain) chain;
+	struct	ip6_fw    *rule;
+};
+
+/*
+ * Values for "flags" field .
+ */
+#define	IPV6_FW_F_IN		0x0001	/* Check inbound packets	*/
+#define	IPV6_FW_F_OUT		0x0002	/* Check outbound packets	*/
+#define	IPV6_FW_F_IIFACE	0x0004	/* Apply inbound interface test	*/
+#define	IPV6_FW_F_OIFACE	0x0008	/* Apply outbound interface test */
+
+#define	IPV6_FW_F_COMMAND 	0x0070	/* Mask for type of chain entry: */
+#define	IPV6_FW_F_DENY		0x0000	/* This is a deny rule		*/
+#define	IPV6_FW_F_REJECT	0x0010	/* Deny and send a response packet */
+#define	IPV6_FW_F_ACCEPT	0x0020	/* This is an accept rule	*/
+#define	IPV6_FW_F_COUNT		0x0030	/* This is a count rule		*/
+#define	IPV6_FW_F_DIVERT	0x0040	/* This is a divert rule	*/
+#define	IPV6_FW_F_TEE		0x0050	/* This is a tee rule		*/
+#define	IPV6_FW_F_SKIPTO	0x0060	/* This is a skipto rule	*/
+
+#define	IPV6_FW_F_PRN		0x0080	/* Print if this rule matches	*/
+
+#define	IPV6_FW_F_SRNG		0x0100	/* The first two src ports are a min  *
+					 * and max range (stored in host byte *
+					 * order). */
+
+#define	IPV6_FW_F_DRNG	0x0200	/* The first two dst ports are a min	*
+				 * and max range (stored in host byte	*
+				 * order).				*/
+
+/* In interface by name/unit (not IP)	*/
+#define	IPV6_FW_F_IIFNAME	0x0400
+/* Out interface by name/unit (not IP)	*/
+#define	IPV6_FW_F_OIFNAME	0x0800
+
+#define	IPV6_FW_F_INVSRC	0x1000	/* Invert sense of src check	*/
+#define	IPV6_FW_F_INVDST	0x2000	/* Invert sense of dst check	*/
+
+#define	IPV6_FW_F_FRAG		0x4000	/* Fragment			*/
+
+#define	IPV6_FW_F_ICMPBIT 	0x8000	/* ICMP type bitmap is valid	*/
+
+#define	IPV6_FW_F_MASK		0xFFFF	/* All possible flag bits mask	*/
+
+/*
+ * For backwards compatibility with rules specifying "via iface" but
+ * not restricted to only "in" or "out" packets, we define this combination
+ * of bits to represent this configuration.
+ */
+
+#define	IF6_FW_F_VIAHACK	(IPV6_FW_F_IN|IPV6_FW_F_OUT|IPV6_FW_F_IIFACE|\
+				 IPV6_FW_F_OIFACE)
+
+/*
+ * Definitions for REJECT response codes.
+ * Values less than 256 correspond to ICMP unreachable codes.
+ */
+#define	IPV6_FW_REJECT_RST	0x0100		/* TCP packets: send RST */
+
+/*
+ * Definitions for IPv6 option names.
+ */
+#define	IPV6_FW_IP6OPT_HOPOPT	0x01
+#define	IPV6_FW_IP6OPT_ROUTE	0x02
+#define	IPV6_FW_IP6OPT_FRAG	0x04
+#define	IPV6_FW_IP6OPT_ESP	0x08
+#define	IPV6_FW_IP6OPT_AH	0x10
+#define	IPV6_FW_IP6OPT_NONXT	0x20
+#define	IPV6_FW_IP6OPT_OPTS	0x40
+
+/*
+ * Definitions for TCP flags.
+ */
+#define	IPV6_FW_TCPF_FIN	TH_FIN
+#define	IPV6_FW_TCPF_SYN	TH_SYN
+#define	IPV6_FW_TCPF_RST	TH_RST
+#define	IPV6_FW_TCPF_PSH	TH_PUSH
+#define	IPV6_FW_TCPF_ACK	TH_ACK
+#define	IPV6_FW_TCPF_URG	TH_URG
+#define	IPV6_FW_TCPF_ESTAB	0x40
+
+/*
+ * Main firewall chains definitions and global var's definitions.
+ */
+#ifdef _KERNEL
+
+/*
+ * Function definitions.
+ */
+void	ip6_fw_init(void);
+
+/* Firewall hooks */
+struct	ip6_hdr;
+typedef	int	ip6_fw_chk_t __P((struct ip6_hdr**, struct ifnet*,
+				u_short *, struct mbuf**));
+typedef	int	ip6_fw_ctl_t __P((int, struct mbuf**));
+extern	ip6_fw_chk_t *ip6_fw_chk_ptr;
+extern	ip6_fw_ctl_t *ip6_fw_ctl_ptr;
+
+#endif /* _KERNEL */
+
+#endif /* _IP6_FW_H */
diff --git a/sys/netinet6/ip6_input.c b/sys/netinet6/ip6_input.c
index 083f780..9c1ca0f 100644
--- a/sys/netinet6/ip6_input.c
+++ b/sys/netinet6/ip6_input.c
@@ -65,6 +65,7 @@
  */
 
 #include "opt_ipsec.h"
+#include "opt_ip6fw.h"
 
 #include <sys/param.h>
 #include <sys/systm.h>
diff --git a/sys/netinet6/ip6_output.c b/sys/netinet6/ip6_output.c
index 0909e9b..b901751 100644
--- a/sys/netinet6/ip6_output.c
+++ b/sys/netinet6/ip6_output.c
@@ -65,6 +65,7 @@
  */
 
 #include "opt_ipsec.h"
+#include "opt_ip6fw.h"
 
 #include <sys/param.h>
 #include <sys/malloc.h>