m_get
if ((error = m_get(totlen, &nm)) != 0)
if ((error = m_get(size, &m)) != 0)
if ((error = m_get(len, &m)) != 0)
if ((error = m_get(size, &mn)) != 0)
err = m_get(size, &m);
n = m_get(M_DONTWAIT, m->m_type);
int m_get(int, mbuf_t **);