Grab ip_fil_freebsd.c r1.42 from the ipfilter CVS tree to fix,

3529491 checksum validation could be better
	3529486 tcp checksum wrong for ipv6

Approved by:	glebius

ip_fil_freebsd.c

@@ -1244,9 +1244,7 @@ ipf_checkv4sum(fin)
 		else
 			sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
 					htonl(m->m_pkthdr.csum_data +
-					fin->fin_ip->ip_len -
-					(fin->fin_ip->ip_hl << 2) +
-					fin->fin_p));
+					fin->fin_dlen + fin->fin_p));
 		sum ^= 0xffff;
 		if (sum != 0) {
 			fin->fin_cksum = FI_CK_BAD;