PPP_HEADER_LEN
2 : PPP_HEADER_LEN;
pkthdrlen = PPP_HEADER_LEN;
if (m->m_pkthdr.len <= PPP_HEADER_LEN) {
m_adj(m, PPP_HEADER_LEN);
M_PREPEND(m, PPP_HEADER_LEN, M_DONTWAIT);