/*******************************************************************************
**
** Function PORT_ParNegCnf
**
** Description This function is called from the RFCOMM layer to change
** DLCI parameters (currently only MTU is negotiated).
** Save the MTU size supported by the peer.
** If the confirmation is received during the port opening
** procedure send EstablishRequest to continue.
**
*******************************************************************************/
void PORT_ParNegCnf (tRFC_MCB *p_mcb, UINT8 dlci, UINT16 mtu, UINT8 cl, UINT8 k)
{
tPORT *p_port = port_find_mcb_dlci_port (p_mcb, dlci);
RFCOMM_TRACE_EVENT ("PORT_ParNegCnf dlci:%d mtu:%d cl: %d k: %d", dlci, mtu, cl, k);
if (!p_port)
return;
/* Flow control mechanism not set yet. Negotiate flow control mechanism. */
if (p_mcb->flow == PORT_FC_UNDEFINED)
{
/* Our stack is configured for TS07.10 and they responded with credit-based. */
/* This is illegal-- negotiation fails. */
if ((PORT_FC_DEFAULT == PORT_FC_TS710) && (cl == RFCOMM_PN_CONV_LAYER_CBFC_R))
{
rfc_send_disc (p_mcb, p_port->dlci);
rfc_port_closed (p_port);
return;
}
/* Our stack is configured for credit-based and they responded with credit-based. */
else if (cl == RFCOMM_PN_CONV_LAYER_CBFC_R)
{
p_mcb->flow = PORT_FC_CREDIT;
}
/* They responded with any other value. Treat this as negotiation to TS07.10. */
else
{
p_mcb->flow = PORT_FC_TS710;
}
}
/* If mux flow control mechanism set, we honor that setting regardless of */
/* the CL value in their response. This allows us to gracefully accept any */
/* illegal PN negotiation scenarios. */
p_port->mtu = (p_port->mtu < mtu) ? p_port->mtu : mtu;
p_port->peer_mtu = p_port->mtu;
if (p_mcb->flow == PORT_FC_CREDIT)
{
port_get_credits (p_port, k);
}
if (p_port->state == PORT_STATE_OPENING)
RFCOMM_DlcEstablishReq (p_mcb, p_port->dlci, p_port->mtu);
}
/*******************************************************************************
**
** Function PORT_ParNegInd
**
** Description This function is called from the RFCOMM layer to change
** DLCI parameters (currently only MTU is negotiated).
** If can not find the port do not accept the request.
** Otherwise save the MTU size supported by the peer.
**
*******************************************************************************/
void PORT_ParNegInd (tRFC_MCB *p_mcb, UINT8 dlci, UINT16 mtu, UINT8 cl, UINT8 k)
{
tPORT *p_port = port_find_mcb_dlci_port (p_mcb, dlci);
UINT8 our_cl;
UINT8 our_k;
RFCOMM_TRACE_EVENT ("PORT_ParNegInd dlci:%d mtu:%d", dlci, mtu);
if (!p_port) {
/* This can be a first request for this port */
p_port = port_find_dlci_port (dlci);
if (!p_port) {
/* If the port cannot be opened, send a DM. Per Errata 1205 */
rfc_send_dm(p_mcb, dlci, FALSE);
/* check if this is the last port open, some headsets have
problem, they don't disconnect if we send DM */
rfc_check_mcb_active( p_mcb );
RFCOMM_TRACE_EVENT( "PORT_ParNegInd: port not found" );
return;
}
p_mcb->port_inx[dlci] = p_port->inx;
}
memcpy (p_port->bd_addr, p_mcb->bd_addr, BD_ADDR_LEN);
/* Connection is up and we know local and remote features, select MTU */
port_select_mtu (p_port);
p_port->rfc.p_mcb = p_mcb;
p_port->mtu = (p_port->mtu < mtu) ? p_port->mtu : mtu;
p_port->peer_mtu = p_port->mtu;
/* Negotiate the flow control mechanism. If flow control mechanism for */
/* mux has not been set yet, set it now. If either we or peer wants TS 07.10, */
/* use that. Otherwise both must want credit based, so use that. If flow is */
/* already defined for this mux, we respond with that value. */
if (p_mcb->flow == PORT_FC_UNDEFINED) {
if ((PORT_FC_DEFAULT == PORT_FC_TS710) || (cl == RFCOMM_PN_CONV_LAYER_TYPE_1)) {
p_mcb->flow = PORT_FC_TS710;
} else {
p_mcb->flow = PORT_FC_CREDIT;
}
}
/* Regardless of our flow control mechanism, if the PN cl is zero, we must */
/* respond with zero. "A responding implementation must set this field to 14 */
/* if (and only if) the PN request was 15." This could happen if a PN is sent */
/* after the DLCI is already established-- the PN in that case must have cl = 0. */
/* See RFCOMM spec 5.5.3 */
if (cl == RFCOMM_PN_CONV_LAYER_TYPE_1) {
our_cl = RFCOMM_PN_CONV_LAYER_TYPE_1;
our_k = 0;
} else if (p_mcb->flow == PORT_FC_CREDIT) {
/* get credits */
port_get_credits (p_port, k);
/* Set convergence layer and number of credits (k) */
our_cl = RFCOMM_PN_CONV_LAYER_CBFC_R;
our_k = (p_port->credit_rx_max < RFCOMM_K_MAX) ? p_port->credit_rx_max : RFCOMM_K_MAX;
p_port->credit_rx = our_k;
} else {
/* must not be using credit based flow control; use TS 7.10 */
our_cl = RFCOMM_PN_CONV_LAYER_TYPE_1;
our_k = 0;
}
RFCOMM_ParNegRsp (p_mcb, dlci, p_port->mtu, our_cl, our_k);
}
