xref: /system/bt/stack/avct/avct_api.cc

/******************************************************************************
 *
 *  Copyright (C) 2003-2016 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 module contains API of the audio/video control transport protocol.
 *
 ******************************************************************************/

#include <string.h>
#include "bt_types.h"
#include "bt_target.h"
#include "bt_utils.h"
#include "bt_common.h"
#include "l2c_api.h"
#include "l2cdefs.h"
#include "btm_api.h"
#include "avct_api.h"
#include "avct_int.h"
#include "osi/include/osi.h"

/* Control block for AVCT */
tAVCT_CB avct_cb;

/*******************************************************************************
 *
 * Function         AVCT_Register
 *
 * Description      This is the system level registration function for the
 *                  AVCTP protocol.  This function initializes AVCTP and
 *                  prepares the protocol stack for its use.  This function
 *                  must be called once by the system or platform using AVCTP
 *                  before the other functions of the API an be used.
 *
 *
 * Returns          void
 *
 ******************************************************************************/
void AVCT_Register(uint16_t mtu,
                   UNUSED_ATTR uint16_t mtu_br, uint8_t sec_mask)
{
    AVCT_TRACE_API("AVCT_Register");

    /* register PSM with L2CAP */
    L2CA_Register(AVCT_PSM, (tL2CAP_APPL_INFO *) &avct_l2c_appl);

    /* set security level */
    BTM_SetSecurityLevel(true, "", BTM_SEC_SERVICE_AVCTP, sec_mask, AVCT_PSM, 0, 0);
    BTM_SetSecurityLevel(false, "", BTM_SEC_SERVICE_AVCTP, sec_mask, AVCT_PSM, 0, 0);

    /* initialize AVCTP data structures */
    memset(&avct_cb, 0, sizeof(tAVCT_CB));

    /* Include the browsing channel which uses eFCR */
    L2CA_Register(AVCT_BR_PSM, (tL2CAP_APPL_INFO *) &avct_l2c_br_appl);

    /* AVCTP browsing channel uses the same security service as AVCTP control channel */
    BTM_SetSecurityLevel(true, "", BTM_SEC_SERVICE_AVCTP, sec_mask, AVCT_BR_PSM, 0, 0);
    BTM_SetSecurityLevel(false, "", BTM_SEC_SERVICE_AVCTP, sec_mask, AVCT_BR_PSM, 0, 0);

    if (mtu_br < AVCT_MIN_BROWSE_MTU)
        mtu_br = AVCT_MIN_BROWSE_MTU;
    avct_cb.mtu_br = mtu_br;

#if defined(AVCT_INITIAL_TRACE_LEVEL)
    avct_cb.trace_level = AVCT_INITIAL_TRACE_LEVEL;
#else
    avct_cb.trace_level = BT_TRACE_LEVEL_NONE;
#endif

    if (mtu < AVCT_MIN_CONTROL_MTU)
        mtu = AVCT_MIN_CONTROL_MTU;
    /* store mtu */
    avct_cb.mtu = mtu;
}

/*******************************************************************************
 *
 * Function         AVCT_Deregister
 *
 * Description      This function is called to deregister use AVCTP protocol.
 *                  It is called when AVCTP is no longer being used by any
 *                  application in the system.  Before this function can be
 *                  called, all connections must be removed with
 *                  AVCT_RemoveConn().
 *
 *
 * Returns          void
 *
 ******************************************************************************/
void AVCT_Deregister(void)
{
    AVCT_TRACE_API("AVCT_Deregister");

    /* deregister PSM with L2CAP */
    L2CA_Deregister(AVCT_PSM);
}

/*******************************************************************************
 *
 * Function         AVCT_CreateConn
 *
 * Description      Create an AVCTP connection.  There are two types of
 *                  connections, initiator and acceptor, as determined by
 *                  the p_cc->role parameter.  When this function is called to
 *                  create an initiator connection, an AVCTP connection to
 *                  the peer device is initiated if one does not already exist.
 *                  If an acceptor connection is created, the connection waits
 *                  passively for an incoming AVCTP connection from a peer device.
 *
 *
 * Returns          AVCT_SUCCESS if successful, otherwise error.
 *
 ******************************************************************************/
uint16_t AVCT_CreateConn(uint8_t *p_handle, tAVCT_CC *p_cc, BD_ADDR peer_addr)
{
    uint16_t    result = AVCT_SUCCESS;
    tAVCT_CCB   *p_ccb;
    tAVCT_LCB   *p_lcb;

    AVCT_TRACE_API("AVCT_CreateConn: %d, control:%d", p_cc->role, p_cc->control);

    /* Allocate ccb; if no ccbs, return failure */
    p_ccb = avct_ccb_alloc(p_cc);
    if (p_ccb == NULL)
    {
        result = AVCT_NO_RESOURCES;
    }
    else
    {
        /* get handle */
        *p_handle = avct_ccb_to_idx(p_ccb);

        /* if initiator connection */
        if (p_cc->role == AVCT_INT)
        {
            /* find link; if none allocate a new one */
            p_lcb = avct_lcb_by_bd(peer_addr);
            if (p_lcb == NULL)
            {
                p_lcb = avct_lcb_alloc(peer_addr);
                if (p_lcb == NULL)
                {
                    /* no link resources; free ccb as well */
                    avct_ccb_dealloc(p_ccb, AVCT_NO_EVT, 0, NULL);
                    result = AVCT_NO_RESOURCES;
                }
            }
            /* check if PID already in use */
            else if (avct_lcb_has_pid(p_lcb, p_cc->pid))
            {
                avct_ccb_dealloc(p_ccb, AVCT_NO_EVT, 0, NULL);
                result = AVCT_PID_IN_USE;
            }

            if (result == AVCT_SUCCESS)
            {
                /* bind lcb to ccb */
                p_ccb->p_lcb = p_lcb;
                AVCT_TRACE_DEBUG("ch_state: %d", p_lcb->ch_state);
                avct_lcb_event(p_lcb, AVCT_LCB_UL_BIND_EVT, (tAVCT_LCB_EVT *) &p_ccb);
            }
        }
    }
    return result;
}

/*******************************************************************************
 *
 * Function         AVCT_RemoveConn
 *
 * Description      Remove an AVCTP connection.  This function is called when
 *                  the application is no longer using a connection.  If this
 *                  is the last connection to a peer the L2CAP channel for AVCTP
 *                  will be closed.
 *
 *
 * Returns          AVCT_SUCCESS if successful, otherwise error.
 *
 ******************************************************************************/
uint16_t AVCT_RemoveConn(uint8_t handle)
{
    uint16_t            result = AVCT_SUCCESS;
    tAVCT_CCB           *p_ccb;

    AVCT_TRACE_API("AVCT_RemoveConn");

    /* map handle to ccb */
    p_ccb = avct_ccb_by_idx(handle);
    if (p_ccb == NULL)
    {
        result = AVCT_BAD_HANDLE;
    }
    /* if connection not bound to lcb, dealloc */
    else if (p_ccb->p_lcb == NULL)
    {
        avct_ccb_dealloc(p_ccb, AVCT_NO_EVT, 0, NULL);
    }
    /* send unbind event to lcb */
    else
    {
        avct_lcb_event(p_ccb->p_lcb, AVCT_LCB_UL_UNBIND_EVT, (tAVCT_LCB_EVT *) &p_ccb);
    }
    return result;
}

/*******************************************************************************
 *
 * Function         AVCT_CreateBrowse
 *
 * Description      Create an AVCTP Browse channel.  There are two types of
 *                  connections, initiator and acceptor, as determined by
 *                  the role parameter.  When this function is called to
 *                  create an initiator connection, the Browse channel to
 *                  the peer device is initiated if one does not already exist.
 *                  If an acceptor connection is created, the connection waits
 *                  passively for an incoming AVCTP connection from a peer device.
 *
 *
 * Returns          AVCT_SUCCESS if successful, otherwise error.
 *
 ******************************************************************************/
uint16_t AVCT_CreateBrowse (uint8_t handle, uint8_t role)
{
    uint16_t    result = AVCT_SUCCESS;
    tAVCT_CCB   *p_ccb;
    tAVCT_BCB   *p_bcb;
    int         index;

    AVCT_TRACE_API("AVCT_CreateBrowse: %d", role);

    /* map handle to ccb */
    p_ccb = avct_ccb_by_idx(handle);
    if (p_ccb == NULL)
    {
        return AVCT_BAD_HANDLE;
    }
    else
    {
        /* mark this CCB as supporting browsing channel */
        if ((p_ccb->allocated & AVCT_ALOC_BCB) == 0)
        {
            p_ccb->allocated |= AVCT_ALOC_BCB;
        }
    }

    /* if initiator connection */
    if (role == AVCT_INT)
    {
        /* the link control block must exist before this function is called as INT. */
        if ((p_ccb->p_lcb == NULL) || (p_ccb->p_lcb->allocated == 0))
        {
            result = AVCT_NOT_OPEN;
        }
        else
        {
            /* find link; if none allocate a new one */
            index = p_ccb->p_lcb->allocated;
            if (index > AVCT_NUM_LINKS)
            {
                result = AVCT_BAD_HANDLE;
            }
            else
            {
                p_bcb = &avct_cb.bcb[index - 1];
                p_bcb->allocated = index;
            }
        }

        if (result == AVCT_SUCCESS)
        {
            /* bind bcb to ccb */
            p_ccb->p_bcb = p_bcb;
            memcpy(p_bcb->peer_addr, p_ccb->p_lcb->peer_addr, BD_ADDR_LEN);
            AVCT_TRACE_DEBUG("ch_state: %d", p_bcb->ch_state);
            avct_bcb_event(p_bcb, AVCT_LCB_UL_BIND_EVT, (tAVCT_LCB_EVT *) &p_ccb);
        }
    }

    return result;
}

/*******************************************************************************
 *
 * Function         AVCT_RemoveBrowse
 *
 * Description      Remove an AVCTP Browse channel.  This function is called when
 *                  the application is no longer using a connection.  If this
 *                  is the last connection to a peer the L2CAP channel for AVCTP
 *                  will be closed.
 *
 *
 * Returns          AVCT_SUCCESS if successful, otherwise error.
 *
 ******************************************************************************/
uint16_t AVCT_RemoveBrowse (uint8_t handle)
{
    uint16_t            result = AVCT_SUCCESS;
    tAVCT_CCB           *p_ccb;

    AVCT_TRACE_API("AVCT_RemoveBrowse");

    /* map handle to ccb */
    p_ccb = avct_ccb_by_idx(handle);
    if (p_ccb == NULL)
    {
        result = AVCT_BAD_HANDLE;
    }
    else if (p_ccb->p_bcb != NULL)
    /* send unbind event to bcb */
    {
        avct_bcb_event(p_ccb->p_bcb, AVCT_LCB_UL_UNBIND_EVT, (tAVCT_LCB_EVT *) &p_ccb);
    }

    return result;
}

/*******************************************************************************
 *
 * Function         AVCT_GetBrowseMtu
 *
 * Description      Get the peer_mtu for the AVCTP Browse channel of the given
 *                  connection.
 *
 * Returns          the peer browsing channel MTU.
 *
 ******************************************************************************/
uint16_t AVCT_GetBrowseMtu (uint8_t handle)
{
    uint16_t peer_mtu = AVCT_MIN_BROWSE_MTU;

    tAVCT_CCB           *p_ccb;

    if ((p_ccb = avct_ccb_by_idx(handle)) != NULL && p_ccb->p_bcb != NULL)
    {
        peer_mtu = p_ccb->p_bcb->peer_mtu;
    }

    return peer_mtu;
}

/*******************************************************************************
 *
 * Function         AVCT_GetPeerMtu
 *
 * Description      Get the peer_mtu for the AVCTP channel of the given
 *                  connection.
 *
 * Returns          the peer MTU size.
 *
 ******************************************************************************/
uint16_t AVCT_GetPeerMtu (uint8_t handle)
{
    uint16_t    peer_mtu = L2CAP_DEFAULT_MTU;
    tAVCT_CCB   *p_ccb;

    /* map handle to ccb */
    p_ccb = avct_ccb_by_idx(handle);
    if (p_ccb != NULL)
    {
        if (p_ccb->p_lcb)
        {
            peer_mtu = p_ccb->p_lcb->peer_mtu;
        }
    }

    return peer_mtu;
}

/*******************************************************************************
 *
 * Function         AVCT_MsgReq
 *
 * Description      Send an AVCTP message to a peer device.  In calling
 *                  AVCT_MsgReq(), the application should keep track of the
 *                  congestion state of AVCTP as communicated with events
 *                  AVCT_CONG_IND_EVT and AVCT_UNCONG_IND_EVT.   If the
 *                  application calls AVCT_MsgReq() when AVCTP is congested
 *                  the message may be discarded.  The application may make its
 *                  first call to AVCT_MsgReq() after it receives an
 *                  AVCT_CONNECT_CFM_EVT or AVCT_CONNECT_IND_EVT on control channel or
 *                  AVCT_BROWSE_CONN_CFM_EVT or AVCT_BROWSE_CONN_IND_EVT on browsing channel.
 *
 *                  p_msg->layer_specific must be set to
 *                  AVCT_DATA_CTRL for control channel traffic;
 *                  AVCT_DATA_BROWSE for for browse channel traffic.
 *
 * Returns          AVCT_SUCCESS if successful, otherwise error.
 *
 ******************************************************************************/
uint16_t AVCT_MsgReq(uint8_t handle, uint8_t label, uint8_t cr, BT_HDR *p_msg)
{
    uint16_t        result = AVCT_SUCCESS;
    tAVCT_CCB       *p_ccb;
    tAVCT_UL_MSG    ul_msg;

    AVCT_TRACE_API("%s", __func__);

    /* verify p_msg parameter */
    if (p_msg == NULL)
    {
        return AVCT_NO_RESOURCES;
    }
    AVCT_TRACE_API("%s len: %d layer_specific: %d", __func__, p_msg->len, p_msg->layer_specific);

    /* map handle to ccb */
    p_ccb = avct_ccb_by_idx(handle);
    if (p_ccb == NULL)
    {
        result = AVCT_BAD_HANDLE;
        osi_free(p_msg);
    }
    /* verify channel is bound to link */
    else if (p_ccb->p_lcb == NULL)
    {
        result = AVCT_NOT_OPEN;
        osi_free(p_msg);
    }

    if (result == AVCT_SUCCESS)
    {
        ul_msg.p_buf = p_msg;
        ul_msg.p_ccb = p_ccb;
        ul_msg.label = label;
        ul_msg.cr = cr;

        /* send msg event to bcb */
        if (p_msg->layer_specific == AVCT_DATA_BROWSE)
        {
            if (p_ccb->p_bcb == NULL && (p_ccb->allocated & AVCT_ALOC_BCB) == 0)
            {
                /* BCB channel is not open and not allocated */
                result = AVCT_BAD_HANDLE;
                osi_free(p_msg);
            }
            else
            {
                p_ccb->p_bcb = avct_bcb_by_lcb(p_ccb->p_lcb);
                avct_bcb_event(p_ccb->p_bcb, AVCT_LCB_UL_MSG_EVT, (tAVCT_LCB_EVT *) &ul_msg);
            }
        }
        /* send msg event to lcb */
        else
        {
            avct_lcb_event(p_ccb->p_lcb, AVCT_LCB_UL_MSG_EVT, (tAVCT_LCB_EVT *) &ul_msg);
        }
    }
    return result;
}