ip6 = mtod(m, struct ip6_hdr *);
udp->uh_ulen = htons(plen + siz + extendsiz + esphlen);
udp->uh_sum = in6_pseudo(&ip6->ip6_src, &ip6->ip6_dst, htonl(ntohs(udp->uh_ulen) + IPPROTO_UDP));
ip6 = mtod(m, struct ip6_hdr *);
udp->uh_ulen = htons(plen + siz + extendsiz + esphlen);
udp->uh_sum = in6_pseudo(&ip6->ip6_src, &ip6->ip6_dst, htonl(ntohs(udp->uh_ulen) + IPPROTO_UDP));