Index: contrib/ipfilter/ip_fil.c
===================================================================
--- contrib/ipfilter/ip_fil.c	(revision 312856)
+++ contrib/ipfilter/ip_fil.c	(working copy)
@@ -840,8 +840,9 @@
 
 
 u_int
-ipf_pcksum(fin, hlen, sum)
+ipf_pcksum(fin, ip, hlen, sum)
 	fr_info_t *fin;
+	ip_t *ip;
 	int hlen;
 	u_int sum;
 {
@@ -849,6 +850,8 @@
 	u_int sum2;
 	int slen;
 
+	ip = ip; 		/* gcc -Wextra */
+
 	slen = fin->fin_plen - hlen;
 	sp = (u_short *)((u_char *)fin->fin_ip + hlen);
 
Index: sys/contrib/ipfilter/netinet/fil.c
===================================================================
--- sys/contrib/ipfilter/netinet/fil.c	(revision 312856)
+++ sys/contrib/ipfilter/netinet/fil.c	(working copy)
@@ -3465,11 +3465,16 @@
 		sum += *sp++;
 		sum += *sp++;	/* ip_dst */
 		sum += *sp++;
+		slen = fin->fin_plen - off;
+		sum += htons(slen);
 #ifdef	USE_INET6
 	} else if (IP_V(ip) == 6) {
+#if 0
 		ip6 = (ip6_t *)ip;
 		hlen = sizeof(*ip6);
+#endif
 		off = ((char *)fin->fin_dp - (char *)fin->fin_ip);
+#if 0
 		sp = (u_short *)&ip6->ip6_src;
 		sum += *sp++;	/* ip6_src */
 		sum += *sp++;
@@ -3488,12 +3493,13 @@
 		sum += *sp++;
 		sum += *sp++;
 		sum += *sp++;
+#else
+		sum = 0;
+#endif
 	} else {
 		return 0xffff;
 	}
 #endif
-	slen = fin->fin_plen - off;
-	sum += htons(slen);
 
 	switch (l4proto)
 	{
@@ -3522,7 +3528,7 @@
 		*csump = 0;
 	}
 
-	sum2 = ipf_pcksum(fin, off, sum);
+	sum2 = ipf_pcksum(fin, ip, off, sum);
 	if (csump != NULL)
 		*csump = sumsave;
 	return sum2;
@@ -6719,10 +6725,15 @@
 
 #ifdef USE_INET6
 	case IPPROTO_ICMPV6 :
+#if 0
 		csump = &((struct icmp6_hdr *)fin->fin_dp)->icmp6_cksum;
 		dosum = 1;
 		break;
+#else
+		fin->fin_cksum = FI_CK_SUMOK;
+		return 0;
 #endif
+#endif
 
 	case IPPROTO_ICMP :
 		csump = &((struct icmp *)fin->fin_dp)->icmp_cksum;
Index: sys/contrib/ipfilter/netinet/ip_fil.h
===================================================================
--- sys/contrib/ipfilter/netinet/ip_fil.h	(revision 312856)
+++ sys/contrib/ipfilter/netinet/ip_fil.h	(working copy)
@@ -1936,7 +1936,7 @@
 extern	int		ipf_matchicmpqueryreply __P((int, icmpinfo_t *,
 						     struct icmp *, int));
 extern	u_32_t		ipf_newisn __P((fr_info_t *));
-extern	u_int		ipf_pcksum __P((fr_info_t *, int, u_int));
+extern	u_int		ipf_pcksum __P((fr_info_t *, ip_t *, int, u_int));
 extern	void		ipf_rule_expire __P((ipf_main_softc_t *));
 extern	int		ipf_scanlist __P((fr_info_t *, u_32_t));
 extern	frentry_t 	*ipf_srcgrpmap __P((fr_info_t *, u_32_t *));
Index: sys/contrib/ipfilter/netinet/ip_fil_freebsd.c
===================================================================
--- sys/contrib/ipfilter/netinet/ip_fil_freebsd.c	(revision 312856)
+++ sys/contrib/ipfilter/netinet/ip_fil_freebsd.c	(working copy)
@@ -1456,8 +1456,9 @@
 
 
 u_int
-ipf_pcksum(fin, hlen, sum)
+ipf_pcksum(fin, ip, hlen, sum)
 	fr_info_t *fin;
+	ip_t *ip;
 	int hlen;
 	u_int sum;
 {
@@ -1467,12 +1468,29 @@
 
 	m = fin->fin_m;
 	off = (char *)fin->fin_dp - (char *)fin->fin_ip;
-	m->m_data += hlen;
-	m->m_len -= hlen;
-	sum2 = in_cksum(fin->fin_m, fin->fin_plen - off);
-	m->m_len += hlen;
-	m->m_data -= hlen;
+#ifdef USE_INET6
+	if (IP_V(ip) == 4) {
+#endif
+		m->m_data += hlen;
+		m->m_len -= hlen;
+		sum2 = in_cksum(fin->fin_m, fin->fin_plen - off);
+		m->m_len += hlen;
+		m->m_data -= hlen;
+#ifdef USE_INET6
+	} else if (IP_V(ip) == 6) {
+		ip6_t *ip6;
 
+		if (m->m_len < sizeof(struct ip6_hdr))
+			return 0xffff;
+
+		ip6 = (ip6_t *)ip;
+		sum2 = in6_cksum(m, ip6->ip6_nxt, hlen, m->m_len - hlen);
+		return(sum2);
+	} else {
+		return 0xffff;
+	}
+#endif
+
 	/*
 	 * Both sum and sum2 are partial sums, so combine them together.
 	 */