stack/rfcomm/rfc_l2cap_if.c

/******************************************************************************
 *
 *  Copyright (C) 1999-2012 Broadcom Corporation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at:
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 ******************************************************************************/

/******************************************************************************
 *
 *  This file contains L2CAP interface functions
 *
 ******************************************************************************/

#include "bt_target.h"
#include "gki.h"

#include "rfcdefs.h"
#include "port_api.h"
#include "port_int.h"
#include "l2c_api.h"
#include "l2cdefs.h"
#include "rfc_int.h"
#include "bt_utils.h"


/*
** Define Callback functions to be called by L2CAP
*/
static void RFCOMM_ConnectInd (BD_ADDR bd_addr, UINT16 lcid, UINT16 psm, UINT8 id);
static void RFCOMM_ConnectCnf (UINT16  lcid, UINT16 err);
static void RFCOMM_ConfigInd (UINT16 lcid, tL2CAP_CFG_INFO *p_cfg);
static void RFCOMM_ConfigCnf (UINT16 lcid, tL2CAP_CFG_INFO *p_cfg);
static void RFCOMM_DisconnectInd (UINT16 lcid, BOOLEAN is_clear);
static void RFCOMM_QoSViolationInd (BD_ADDR bd_addr);
static void RFCOMM_BufDataInd (UINT16 lcid, BT_HDR *p_buf);
static void RFCOMM_CongestionStatusInd (UINT16 lcid, BOOLEAN is_congested);


/*******************************************************************************
**
** Function         rfcomm_l2cap_if_init
**
** Description      This function is called during the RFCOMM task startup
**                  to register interface functions with L2CAP.
**
*******************************************************************************/
void rfcomm_l2cap_if_init (void)
{
    tL2CAP_APPL_INFO *p_l2c = &rfc_cb.rfc.reg_info;

    p_l2c->pL2CA_ConnectInd_Cb       = RFCOMM_ConnectInd;
    p_l2c->pL2CA_ConnectCfm_Cb       = RFCOMM_ConnectCnf;
    p_l2c->pL2CA_ConnectPnd_Cb       = NULL;
    p_l2c->pL2CA_ConfigInd_Cb        = RFCOMM_ConfigInd;
    p_l2c->pL2CA_ConfigCfm_Cb        = RFCOMM_ConfigCnf;
    p_l2c->pL2CA_DisconnectInd_Cb    = RFCOMM_DisconnectInd;
    p_l2c->pL2CA_DisconnectCfm_Cb    = NULL;
    p_l2c->pL2CA_QoSViolationInd_Cb  = RFCOMM_QoSViolationInd;
    p_l2c->pL2CA_DataInd_Cb          = RFCOMM_BufDataInd;
    p_l2c->pL2CA_CongestionStatus_Cb = RFCOMM_CongestionStatusInd;
    p_l2c->pL2CA_TxComplete_Cb       = NULL;


    L2CA_Register (BT_PSM_RFCOMM, p_l2c);
}


/*******************************************************************************
**
** Function         RFCOMM_ConnectInd
**
** Description      This is a callback function called by L2CAP when
**                  L2CA_ConnectInd received.  Allocate multiplexer control block
**                  and dispatch the event to it.
**
*******************************************************************************/
void RFCOMM_ConnectInd (BD_ADDR bd_addr, UINT16 lcid, UINT16 psm, UINT8 id)
{
    tRFC_MCB *p_mcb = rfc_alloc_multiplexer_channel(bd_addr, FALSE);
    UNUSED(psm);

    if ((p_mcb)&&(p_mcb->state != RFC_MX_STATE_IDLE))
    {
        /* if this is collision case */
        if ((p_mcb->is_initiator)&&(p_mcb->state == RFC_MX_STATE_WAIT_CONN_CNF))
        {
            p_mcb->pending_lcid = lcid;
            p_mcb->pending_id   = id;

            /* wait random timeout (2 - 12) to resolve collision */
            /* if peer gives up then local device rejects incoming connection and continues as initiator */
            /* if timeout, local device disconnects outgoing connection and continues as acceptor */
            RFCOMM_TRACE_DEBUG ("RFCOMM_ConnectInd start timer for collision, initiator's LCID(0x%x), acceptor's LCID(0x%x)",
                                  p_mcb->lcid, p_mcb->pending_lcid);

            rfc_timer_start(p_mcb, (UINT16)(GKI_get_tick_count()%10 + 2));
            return;
        }
        else
        {
            /* we cannot accept connection request from peer at this state */
            /* don't update lcid */
            p_mcb = NULL;
        }
    }
    else
    {
        /* store mcb even if null */
        rfc_save_lcid_mcb (p_mcb, lcid);
    }

    if (p_mcb == NULL)
    {
        L2CA_ConnectRsp (bd_addr, id, lcid, L2CAP_CONN_NO_RESOURCES, 0);
        return;
    }
    p_mcb->lcid     = lcid;

    rfc_mx_sm_execute (p_mcb, RFC_MX_EVENT_CONN_IND, &id);
}


/*******************************************************************************
**
** Function         RFCOMM_ConnectCnf
**
** Description      This is a callback function called by L2CAP when
**                  L2CA_ConnectCnf received.  Save L2CAP handle and dispatch
**                  event to the FSM.
**
*******************************************************************************/
void RFCOMM_ConnectCnf (UINT16 lcid, UINT16 result)
{
    tRFC_MCB *p_mcb = rfc_find_lcid_mcb (lcid);

    if (!p_mcb)
    {
        RFCOMM_TRACE_ERROR ("RFCOMM_ConnectCnf LCID:0x%x", lcid);
        return;
    }

    if (p_mcb->pending_lcid)
    {
        /* if peer rejects our connect request but peer's connect request is pending */
        if (result != L2CAP_CONN_OK )
        {
            UINT16 i;
            UINT8  idx;

            RFCOMM_TRACE_DEBUG ("RFCOMM_ConnectCnf retry as acceptor on pending LCID(0x%x)", p_mcb->pending_lcid);

            /* remove mcb from mapping table */
            rfc_save_lcid_mcb (NULL, p_mcb->lcid);

            p_mcb->lcid         = p_mcb->pending_lcid;
            p_mcb->is_initiator = FALSE;
            p_mcb->state        = RFC_MX_STATE_IDLE;

            /* store mcb into mapping table */
            rfc_save_lcid_mcb (p_mcb, p_mcb->lcid);

            /* update direction bit */
            for (i = 0; i < RFCOMM_MAX_DLCI; i += 2)
            {
                if ((idx = p_mcb->port_inx[i]) != 0)
                {
                    p_mcb->port_inx[i] = 0;
                    p_mcb->port_inx[i+1] = idx;
                    rfc_cb.port.port[idx - 1].dlci += 1;
                    RFCOMM_TRACE_DEBUG ("RFCOMM MX - DLCI:%d -> %d", i, rfc_cb.port.port[idx - 1].dlci);
                }
            }

            rfc_mx_sm_execute (p_mcb, RFC_MX_EVENT_CONN_IND, &(p_mcb->pending_id));
            return;
        }
        else
        {
            RFCOMM_TRACE_DEBUG ("RFCOMM_ConnectCnf peer gave up pending LCID(0x%x)", p_mcb->pending_lcid);

            /* Peer gave up his connection request, make sure cleaning up L2CAP channel */
            L2CA_ConnectRsp (p_mcb->bd_addr, p_mcb->pending_id, p_mcb->pending_lcid, L2CAP_CONN_NO_RESOURCES, 0);

            p_mcb->pending_lcid = 0;
        }
    }

    /* Save LCID to be used in all consecutive calls to L2CAP */
    p_mcb->lcid         = lcid;

    rfc_mx_sm_execute (p_mcb, RFC_MX_EVENT_CONN_CNF, &result);
}


/*******************************************************************************
**
** Function         RFCOMM_ConfigInd
**
** Description      This is a callback function called by L2CAP when
**                  L2CA_ConfigInd received.  Save parameters in the control
**                  block and dispatch event to the FSM.
**
*******************************************************************************/
void RFCOMM_ConfigInd (UINT16 lcid, tL2CAP_CFG_INFO *p_cfg)
{
    tRFC_MCB *p_mcb = rfc_find_lcid_mcb (lcid);

    if (!p_mcb)
    {
        RFCOMM_TRACE_ERROR ("RFCOMM_ConfigInd LCID:0x%x", lcid);
        return;
    }

    rfc_mx_sm_execute (p_mcb, RFC_MX_EVENT_CONF_IND, (void *)p_cfg);
}


/*******************************************************************************
**
** Function         RFCOMM_ConfigCnf
**
** Description      This is a callback function called by L2CAP when
**                  L2CA_ConfigCnf received.  Save L2CAP handle and dispatch
**                  event to the FSM.
**
*******************************************************************************/
void RFCOMM_ConfigCnf (UINT16 lcid, tL2CAP_CFG_INFO *p_cfg)
{
    tRFC_MCB *p_mcb = rfc_find_lcid_mcb (lcid);

    if (!p_mcb)
    {
        RFCOMM_TRACE_ERROR ("RFCOMM_ConfigCnf no MCB LCID:0x%x", lcid);
        return;
    }

    rfc_mx_sm_execute (p_mcb, RFC_MX_EVENT_CONF_CNF, (void *)p_cfg);
}


/*******************************************************************************
**
** Function         RFCOMM_QoSViolationInd
**
** Description      This is a callback function called by L2CAP when
**                  L2CA_QoSViolationIndInd received.  Dispatch event to the FSM.
**
*******************************************************************************/
void RFCOMM_QoSViolationInd (BD_ADDR bd_addr)
{
    UNUSED(bd_addr);
}


/*******************************************************************************
**
** Function         RFCOMM_DisconnectInd
**
** Description      This is a callback function called by L2CAP when
**                  L2CA_DisconnectInd received.  Dispatch event to the FSM.
**
*******************************************************************************/
void RFCOMM_DisconnectInd (UINT16 lcid, BOOLEAN is_conf_needed)
{
    tRFC_MCB *p_mcb = rfc_find_lcid_mcb (lcid);

    if (is_conf_needed)
    {
        L2CA_DisconnectRsp (lcid);
    }

    if (!p_mcb)
    {
        RFCOMM_TRACE_WARNING ("RFCOMM_DisconnectInd LCID:0x%x", lcid);
        return;
    }

    rfc_mx_sm_execute (p_mcb, RFC_MX_EVENT_DISC_IND, NULL);
}


/*******************************************************************************
**
** Function         RFCOMM_BufDataInd
**
** Description      This is a callback function called by L2CAP when
**                  data RFCOMM frame is received.  Parse the frames, check
**                  the checksum and dispatch event to multiplexer or port
**                  state machine depending on the frame destination.
**
*******************************************************************************/
void RFCOMM_BufDataInd (UINT16 lcid, BT_HDR *p_buf)
{
    tRFC_MCB *p_mcb = rfc_find_lcid_mcb (lcid);
    tPORT    *p_port;
    UINT8    event;


    if (!p_mcb)
    {
        RFCOMM_TRACE_WARNING ("RFCOMM_BufDataInd LCID:0x%x", lcid);
        GKI_freebuf (p_buf);
        return;
    }

    event = rfc_parse_data (p_mcb, &rfc_cb.rfc.rx_frame, p_buf);

    /* If the frame did not pass validation just ignore it */
    if (event == RFC_EVENT_BAD_FRAME)
    {
        GKI_freebuf (p_buf);
        return;
    }

    if (rfc_cb.rfc.rx_frame.dlci == RFCOMM_MX_DLCI)
    {
        /* Take special care of the Multiplexer Control Messages */
        if (event == RFC_EVENT_UIH)
        {
            rfc_process_mx_message (p_mcb, p_buf);
            return;
        }

        /* Other multiplexer events go to state machine */
        rfc_mx_sm_execute (p_mcb, event, NULL);
        GKI_freebuf (p_buf);
        return;
    }

    /* The frame was received on the data channel DLCI, verify that DLC exists */
    if (((p_port = port_find_mcb_dlci_port (p_mcb, rfc_cb.rfc.rx_frame.dlci)) == NULL)
     || (!p_port->rfc.p_mcb))
    {
        /* If this is a SABME on the new port, check if any appl is waiting for it */
        if (event != RFC_EVENT_SABME)
        {
            if (( p_mcb->is_initiator && !rfc_cb.rfc.rx_frame.cr)
             || (!p_mcb->is_initiator &&  rfc_cb.rfc.rx_frame.cr))
                rfc_send_dm (p_mcb, rfc_cb.rfc.rx_frame.dlci, rfc_cb.rfc.rx_frame.pf);
            GKI_freebuf (p_buf);
            return;
        }

        if ((p_port = port_find_dlci_port (rfc_cb.rfc.rx_frame.dlci)) == NULL)
        {
            rfc_send_dm (p_mcb, rfc_cb.rfc.rx_frame.dlci, TRUE);
            GKI_freebuf (p_buf);
            return;
        }
        p_mcb->port_inx[rfc_cb.rfc.rx_frame.dlci] = p_port->inx;
        p_port->rfc.p_mcb = p_mcb;
    }

    if (event == RFC_EVENT_UIH)
    {
        if (p_buf->len > 0)
            rfc_port_sm_execute (p_port, event, p_buf);
        else
            GKI_freebuf (p_buf);

        if (rfc_cb.rfc.rx_frame.credit != 0)
            rfc_inc_credit (p_port, rfc_cb.rfc.rx_frame.credit);

        return;
    }
    rfc_port_sm_execute (p_port, event,  NULL);
    GKI_freebuf (p_buf);
}

/*******************************************************************************
**
** Function         RFCOMM_CongestionStatusInd
**
** Description      This is a callback function called by L2CAP when
**                  data RFCOMM L2CAP congestion status changes
**
*******************************************************************************/
void RFCOMM_CongestionStatusInd (UINT16 lcid, BOOLEAN is_congested)
{
    tRFC_MCB *p_mcb = rfc_find_lcid_mcb (lcid);

    if (!p_mcb)
    {
        RFCOMM_TRACE_ERROR ("RFCOMM_CongestionStatusInd dropped LCID:0x%x", lcid);
        return;
    }
    else
    {
        RFCOMM_TRACE_EVENT ("RFCOMM_CongestionStatusInd LCID:0x%x", lcid);
    }
    rfc_process_l2cap_congestion (p_mcb, is_congested);
}

/*******************************************************************************
**
** Function         rfc_find_lcid_mcb
**
** Description      This function returns MCB block supporting local cid
**
*******************************************************************************/
tRFC_MCB *rfc_find_lcid_mcb (UINT16 lcid)
{
    tRFC_MCB *p_mcb;

    if (lcid - L2CAP_BASE_APPL_CID >= MAX_L2CAP_CHANNELS)
    {
        RFCOMM_TRACE_ERROR ("rfc_find_lcid_mcb LCID:0x%x", lcid);
        return (NULL);
    }
    else
    {
        if ((p_mcb = rfc_cb.rfc.p_rfc_lcid_mcb[lcid - L2CAP_BASE_APPL_CID]) != NULL)
        {
            if (p_mcb->lcid != lcid)
            {
                RFCOMM_TRACE_WARNING ("rfc_find_lcid_mcb LCID reused LCID:0x%x current:0x%x", lcid, p_mcb->lcid);
                return (NULL);
            }
        }
    }
    return (p_mcb);
}


/*******************************************************************************
**
** Function         rfc_save_lcid_mcb
**
** Description      This function returns MCB block supporting local cid
**
*******************************************************************************/
void rfc_save_lcid_mcb (tRFC_MCB *p_mcb, UINT16 lcid)
{
    rfc_cb.rfc.p_rfc_lcid_mcb[lcid - L2CAP_BASE_APPL_CID] = p_mcb;
}