ipf_pr_ipv6exthdr
ah = (authhdr_t *)ipf_pr_ipv6exthdr(fin, 0, IPPROTO_HOPOPTS);
static inline struct ip6_ext *ipf_pr_ipv6exthdr(fr_info_t *, int, int);
hdr = ipf_pr_ipv6exthdr(fin, 0, IPPROTO_HOPOPTS);
hdr = ipf_pr_ipv6exthdr(fin, 0, IPPROTO_MOBILITY);
hdr = (struct ip6_routing *)ipf_pr_ipv6exthdr(fin, 0, IPPROTO_ROUTING);
frag = (struct ip6_frag *)ipf_pr_ipv6exthdr(fin, 0, IPPROTO_FRAGMENT);
hdr = ipf_pr_ipv6exthdr(fin, 0, IPPROTO_DSTOPTS);