Function sppp_cp_send

freebsd/net/if_spppsubr.c:1407–1447

* Send PPP control protocol packet. */

 * Send PPP control protocol packet.
 */
static void
sppp_cp_send(struct sppp *sp, u_short proto, u_char type,
	     u_char ident, u_short len, void *data)
{
	STDDCL;
	struct ppp_header *h;
	struct lcp_header *lh;
	struct mbuf *m;

	if (len > MHLEN - PPP_HEADER_LEN - LCP_HEADER_LEN)
		len = MHLEN - PPP_HEADER_LEN - LCP_HEADER_LEN;
	MGETHDR (m, M_NOWAIT, MT_DATA);
	if (! m)
		return;
	m->m_pkthdr.len = m->m_len = PPP_HEADER_LEN + LCP_HEADER_LEN + len;
	m->m_pkthdr.rcvif = 0;

	h = mtod (m, struct ppp_header*);
	h->address = PPP_ALLSTATIONS;        /* broadcast address */
	h->control = PPP_UI;                 /* Unnumbered Info */
	h->protocol = htons (proto);         /* Link Control Protocol */

	lh = (struct lcp_header*) (h + 1);
	lh->type = type;
	lh->ident = ident;
	lh->len = htons (LCP_HEADER_LEN + len);
	if (len)
		bcopy (data, lh+1, len);

	if (debug) {
		log(LOG_DEBUG, SPP_FMT "%s output <%s id=0x%x len=%d",
		    SPP_ARGS(ifp),
		    sppp_proto_name(proto),
		    sppp_cp_type_name (lh->type), lh->ident,
		    ntohs (lh->len));
		sppp_print_bytes ((u_char*) (lh+1), len);
		log(-1, ">\n");
	}
	if (! IF_HANDOFF_ADJ(&sp->pp_cpq, m, ifp, 3))
		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
}

/*
 * Handle incoming PPP control protocol packets.