PPP_HEADER_LEN
m->m_pkthdr.len = m->m_len = PPP_HEADER_LEN + CISCO_PACKET_LEN;
if (len > MHLEN - PPP_HEADER_LEN - LCP_HEADER_LEN)
len = MHLEN - PPP_HEADER_LEN - LCP_HEADER_LEN;
m->m_pkthdr.len = m->m_len = PPP_HEADER_LEN + LCP_HEADER_LEN + len;
if (len > MHLEN - PPP_HEADER_LEN - LCP_HEADER_LEN) {
m->m_pkthdr.len = m->m_len = PPP_HEADER_LEN + LCP_HEADER_LEN + len;
if (m->m_pkthdr.len <= PPP_HEADER_LEN) {
m_adj (m, PPP_HEADER_LEN);
M_PREPEND (m, PPP_HEADER_LEN, M_NOWAIT);