m_getb
n = m_getb(replylen, M_NOWAIT, m->m_type, M_PKTHDR);
m = m_getb(len, M_NOWAIT, MT_DATA, 0);
m = m_getb(IPV6_MMTU, M_NOWAIT, MT_HEADER, M_PKTHDR);
n = m_getb(maxlen, M_NOWAIT, n0->m_type, M_PKTHDR);
n = m_getb(maxlen, M_NOWAIT, m->m_type, M_PKTHDR);
n = m_getb(elen, M_NOWAIT, MT_DATA, 0);
n = m_getb(m->m_pkthdr.len, M_NOWAIT, MT_DATA, M_PKTHDR);
m = m_getb(hlen, M_NOWAIT, MT_DATA, 0);
m = m_getb(max_linkhdr + maxlen, M_NOWAIT, MT_DATA, M_PKTHDR);
m = m_getb(max_linkhdr + maxlen, M_NOWAIT, MT_DATA, M_PKTHDR);