M_CSUM_DATA_IPv6_OFFSET
M_CSUM_DATA_IPv6_OFFSET(m0->m_pkthdr.csum_data)) |
l4offset += M_CSUM_DATA_IPv6_OFFSET(m->m_pkthdr.csum_data);
offset += M_CSUM_DATA_IPv6_OFFSET(m->m_pkthdr.csum_data);