M_HASCL
if (mb0 && (M_HASCL(mb0) || mb0->m_len < hlen))
if (mm && (M_HASCL(mm) || mm->m_len < hlen))
if (mb_copy && (M_HASCL(mb_copy) || mb_copy->m_len < hlen))
(M_HASCL(mb0) || mb0->m_len < sizeof(struct ip6_hdr)))
(M_HASCL(mm) ||
(M_HASCL(mb_copy) || mb_copy->m_len < sizeof(struct ip6_hdr)))