ng_ppp_prepend
if ((m = ng_ppp_prepend(m, &ng_ppp_acf, 2)) == NULL)
m2 = ng_ppp_prepend(m2, &shdr, 2);
m2 = ng_ppp_prepend(m2, &lhdr, 4);
return ng_ppp_prepend(m, &pbyte, 1);
return ng_ppp_prepend(m, &pword, 2);
static struct mbuf *ng_ppp_prepend(struct mbuf *m, const void *buf, int len);
if ((m = ng_ppp_prepend(m, &hdr, 4)) == NULL) {