Function ng_l2cap_lp_send

freebsd/netgraph/bluetooth/l2cap/ng_l2cap_llpi.c:543–643

 */

int
ng_l2cap_lp_send(ng_l2cap_con_p con, u_int16_t dcid, struct mbuf *m0)
{
	ng_l2cap_p		 l2cap = con->l2cap;
	ng_l2cap_hdr_t		*l2cap_hdr = NULL;
        ng_hci_acldata_pkt_t	*acl_hdr = NULL;
        struct mbuf		*m_last = NULL, *m = NULL;
        int			 len, flag = (con->linktype == NG_HCI_LINK_ACL) ? NG_HCI_PACKET_START : NG_HCI_LE_PACKET_START;

	KASSERT((con->tx_pkt == NULL),
("%s: %s - another packet pending?!\n", __func__, NG_NODE_NAME(l2cap->node)));
	KASSERT((l2cap->pkt_size > 0),
("%s: %s - invalid l2cap->pkt_size?!\n", __func__, NG_NODE_NAME(l2cap->node)));

	/* Prepend mbuf with L2CAP header */
	m0 = ng_l2cap_prepend(m0, sizeof(*l2cap_hdr));
	if (m0 == NULL) {
		NG_L2CAP_ALERT(
"%s: %s - ng_l2cap_prepend(%zd) failed\n",
			__func__, NG_NODE_NAME(l2cap->node),
			sizeof(*l2cap_hdr));

		goto fail;
	}

	l2cap_hdr = mtod(m0, ng_l2cap_hdr_t *);
	l2cap_hdr->length = htole16(m0->m_pkthdr.len - sizeof(*l2cap_hdr));
	l2cap_hdr->dcid = htole16(dcid);

	/*
	 * Segment single L2CAP packet according to the HCI layer MTU. Convert 
	 * each segment into ACL data packet and prepend it with ACL data packet
	 * header. Link all segments together via m_nextpkt link. 
 	 *
	 * XXX BC (Broadcast flag) will always be 0 (zero).
	 */

	while (m0 != NULL) {
		/* Check length of the packet against HCI MTU */
		len = m0->m_pkthdr.len;
		if (len > l2cap->pkt_size) {
			m = m_split(m0, l2cap->pkt_size, M_NOWAIT);
			if (m == NULL) {
				NG_L2CAP_ALERT(
"%s: %s - m_split(%d) failed\n",	__func__, NG_NODE_NAME(l2cap->node),
					l2cap->pkt_size);
				goto fail;
			}

			len = l2cap->pkt_size;
		}

		/* Convert packet fragment into ACL data packet */
		m0 = ng_l2cap_prepend(m0, sizeof(*acl_hdr));
		if (m0 == NULL) {
			NG_L2CAP_ALERT(
"%s: %s - ng_l2cap_prepend(%zd) failed\n",
				__func__, NG_NODE_NAME(l2cap->node),