xref: /aosp_15_r20/packages/modules/Bluetooth/system/stack/rfcomm/port_rfc.cc

/******************************************************************************
 *
 *  Copyright 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 module contains functions for port emulation entity and RFCOMM
 *  communications
 *
 ******************************************************************************/

#define LOG_TAG "rfcomm"

#include <base/functional/callback.h>
#include <bluetooth/log.h>
#include <frameworks/proto_logging/stats/enums/bluetooth/enums.pb.h>

#include <cstdint>

#include "hal/snoop_logger.h"
#include "internal_include/bt_target.h"
#include "internal_include/bt_trace.h"
#include "main/shim/entry.h"
#include "os/logging/log_adapter.h"
#include "osi/include/allocator.h"
#include "osi/include/mutex.h"
#include "stack/include/bt_hdr.h"
#include "stack/include/bt_uuid16.h"
#include "stack/include/stack_metrics_logging.h"
#include "stack/l2cap/l2c_int.h"
#include "stack/rfcomm/port_int.h"
#include "stack/rfcomm/rfc_int.h"

using namespace bluetooth;

/*
 * Local function definitions
 */
uint32_t port_rfc_send_tx_data(tPORT* p_port);
void port_rfc_closed(tPORT* p_port, uint8_t res);
void port_get_credits(tPORT* p_port, uint8_t k);

/*******************************************************************************
 *
 * Function         port_open_continue
 *
 * Description      This function is called after security manager completes
 *                  required security checks.
 *
 * Returns          PORT_SUCCESS or PORT_[ERROR]
 *
 ******************************************************************************/
int port_open_continue(tPORT* p_port) {
  log::verbose("port_open_continue, p_port:{}", std::format_ptr(p_port));

  /* Check if multiplexer channel has already been established */
  tRFC_MCB* p_mcb = rfc_alloc_multiplexer_channel(p_port->bd_addr, true);
  if (p_mcb == nullptr) {
    log::warn("port_open_continue no mx channel");
    port_release_port(p_port);
    return PORT_NO_RESOURCES;
  }

  p_port->rfc.p_mcb = p_mcb;

  p_mcb->port_handles[p_port->dlci] = p_port->handle;

  /* Connection is up and we know local and remote features, select MTU */
  port_select_mtu(p_port);

  switch (p_mcb->state) {
    case RFC_MX_STATE_CONNECTED:
      RFCOMM_ParameterNegotiationRequest(p_mcb, p_port->dlci, p_port->mtu);
      log::verbose("Multiplexer already connected peer:{} state:{} cid:{}", p_port->bd_addr,
                   p_mcb->state, p_mcb->lcid);
      break;

    case RFC_MX_STATE_IDLE:
    case RFC_MX_STATE_DISC_WAIT_UA:
      // In RFC_MX_STATE_IDLE state, MX state machine will create connection
      // In RFC_MX_STATE_DISC_WAIT_UA state, MX state machine will recreate
      // connection after disconnecting is completed
      RFCOMM_StartReq(p_mcb);
      log::verbose("Starting multiplexer connect peer:{} state:{} cid:{}", p_port->bd_addr,
                   p_mcb->state, p_mcb->lcid);
      break;

    default:
      // MX state machine ignores RFC_MX_EVENT_START_REQ in these states
      // When it enters RFC_MX_STATE_CONNECTED, it will check any opening ports
      log::verbose("Ignoring RFC_MX_EVENT_START_REQ peer:{} state:{} cid:{}", p_port->bd_addr,
                   p_mcb->state, p_mcb->lcid);
      break;
  }
  return PORT_SUCCESS;
}

/*******************************************************************************
 *
 * Function         port_start_control
 *
 * Description      This function is called in the BTU_TASK context to
 *                  send control information
 *
 ******************************************************************************/
void port_start_control(tPORT* p_port) {
  tRFC_MCB* p_mcb = p_port->rfc.p_mcb;

  if (p_mcb == NULL) {
    return;
  }

  RFCOMM_ControlReq(p_mcb, p_port->dlci, &p_port->local_ctrl);
}

/*******************************************************************************
 *
 * Function         port_start_par_neg
 *
 * Description      This function is called in the BTU_TASK context to
 *                  send configuration information
 *
 ******************************************************************************/
void port_start_par_neg(tPORT* p_port) {
  tRFC_MCB* p_mcb = p_port->rfc.p_mcb;

  if (p_mcb == NULL) {
    return;
  }

  RFCOMM_PortParameterNegotiationRequest(p_mcb, p_port->dlci, &p_port->user_port_settings);
}

/*******************************************************************************
 *
 * Function         port_start_close
 *
 * Description      This function is called in the BTU_TASK context to
 *                  release DLC
 *
 ******************************************************************************/
void port_start_close(tPORT* p_port) {
  tRFC_MCB* p_mcb = p_port->rfc.p_mcb;
  uint8_t old_signals;
  uint32_t events = 0;

  /* At first indicate to the user that signals on the connection were dropped
   */
  p_port->line_status |= LINE_STATUS_FAILED;
  old_signals = p_port->peer_ctrl.modem_signal;

  p_port->peer_ctrl.modem_signal &= ~(PORT_DTRDSR_ON | PORT_CTSRTS_ON | PORT_DCD_ON);

  events |= port_get_signal_changes(p_port, old_signals, p_port->peer_ctrl.modem_signal);

  if (p_port->ev_mask & PORT_EV_CONNECT_ERR) {
    events |= PORT_EV_CONNECT_ERR;
  }

  if (p_port->ev_mask & PORT_EV_ERR) {
    events |= PORT_EV_ERR;
  }

  if ((p_port->p_callback != NULL) && events) {
    p_port->p_callback(events, p_port->handle);
  }

  /* Check if RFCOMM side has been closed while the message was queued */
  if ((p_mcb == NULL) || (p_port->rfc.state == RFC_STATE_CLOSED)) {
    /* Call management callback function before calling port_release_port() to
     * clear tPort */
    if (p_port->p_mgmt_callback) {
      p_port->p_mgmt_callback(PORT_CLOSED, p_port->handle);
      log_counter_metrics(android::bluetooth::CodePathCounterKeyEnum::RFCOMM_PORT_START_CLOSE, 1);
    }

    port_release_port(p_port);
  } else {
    RFCOMM_DlcReleaseReq(p_mcb, p_port->dlci);
  }
}

/*******************************************************************************
 *
 * Function         PORT_StartCnf
 *
 * Description      This function is called from the RFCOMM layer when
 *                  establishing of the multiplexer channel is completed.
 *                  Continue establishing of the connection for all ports that
 *                  are in the OPENING state
 *
 ******************************************************************************/
void PORT_StartCnf(tRFC_MCB* p_mcb, uint16_t result) {
  bool no_ports_up = true;

  log::verbose("result {}", result);

  tPORT* p_port = &rfc_cb.port.port[0];
  for (int i = 0; i < MAX_RFC_PORTS; i++, p_port++) {
    if (p_port->rfc.p_mcb == p_mcb) {
      no_ports_up = false;

      if (result == RFCOMM_SUCCESS) {
        log::verbose("dlci {}", p_port->dlci);
        RFCOMM_ParameterNegotiationRequest(p_mcb, p_port->dlci, p_port->mtu);
      } else {
        log::warn("Unable start configuration dlci:{} result:{}", p_port->dlci, result);

        rfc_release_multiplexer_channel(p_mcb);

        /* Send event to the application */
        if (p_port->p_callback && (p_port->ev_mask & PORT_EV_CONNECT_ERR)) {
          (p_port->p_callback)(PORT_EV_CONNECT_ERR, p_port->handle);
        }

        if (p_port->p_mgmt_callback) {
          p_port->p_mgmt_callback(PORT_START_FAILED, p_port->handle);
          log_counter_metrics(
                  android::bluetooth::CodePathCounterKeyEnum::RFCOMM_PORT_START_CNF_FAILED, 1);
        }
        port_release_port(p_port);
      }
    }
  }

  /* There can be a situation when after starting connection, user closes the */
  /* port, we can catch it here to close multiplexor channel */
  if (no_ports_up) {
    rfc_check_mcb_active(p_mcb);
  }
}

/*******************************************************************************
 *
 * Function         PORT_StartInd
 *
 * Description      This function is called from the RFCOMM layer when
 *                  some peer device wants to establish a multiplexer
 *                  connection.  Check if there are any ports open with this
 *                  or not assigned multiplexer.
 *
 ******************************************************************************/
void PORT_StartInd(tRFC_MCB* p_mcb) {
  tPORT* p_port;
  int i;

  log::verbose("PORT_StartInd");

  p_port = &rfc_cb.port.port[0];
  for (i = 0; i < MAX_RFC_PORTS; i++, p_port++) {
    if ((p_port->rfc.p_mcb == NULL) || (p_port->rfc.p_mcb == p_mcb)) {
      log::verbose("PORT_StartInd, RFCOMM_StartRsp RFCOMM_SUCCESS: p_mcb:{}",
                   std::format_ptr(p_mcb));
      RFCOMM_StartRsp(p_mcb, RFCOMM_SUCCESS);
      return;
    }
  }
  RFCOMM_StartRsp(p_mcb, RFCOMM_ERROR);
}

/*******************************************************************************
 *
 * 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_t dlci, uint16_t mtu, uint8_t cl, uint8_t k) {
  log::verbose("bd_addr={}, dlci={}, mtu={}", p_mcb->bd_addr, dlci, mtu);
  tPORT* p_port = port_find_mcb_dlci_port(p_mcb, dlci);
  if (!p_port) {
    /* This can be a first request for this port */
    p_port = port_find_dlci_port(dlci);
    if (!p_port) {
      log::error("Disconnect RFCOMM, port not found, dlci={}, p_mcb={}, bd_addr={}", dlci,
                 std::format_ptr(p_mcb), p_mcb->bd_addr);
      /* 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);
      return;
    }
    log::verbose("port_handles[dlci:{}]:{}->{}", dlci, p_mcb->port_handles[dlci], p_port->handle);
    p_mcb->port_handles[dlci] = p_port->handle;
  }

  p_port->bd_addr = p_mcb->bd_addr;

  /* 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 (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 */
  uint8_t our_cl;
  uint8_t our_k;
  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_ParameterNegotiationResponse(p_mcb, dlci, p_port->mtu, our_cl, our_k);
}

/*******************************************************************************
 *
 * 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_t dlci, uint16_t mtu, uint8_t cl, uint8_t k) {
  log::verbose("PORT_ParNegCnf dlci:{} mtu:{} cl: {} k: {}", dlci, mtu, cl, k);
  tPORT* p_port = port_find_mcb_dlci_port(p_mcb, dlci);
  if (!p_port) {
    log::warn("port is null for {}", p_mcb->bd_addr);
    return;
  }

  /* Flow control mechanism not set yet.  Negotiate flow control mechanism. */
  if (p_mcb->flow == PORT_FC_UNDEFINED) {
    if (cl == RFCOMM_PN_CONV_LAYER_CBFC_R) {
      // Our stack is configured for credit-based and they responded with
      // credit-based.
      p_mcb->flow = PORT_FC_CREDIT;
    } else {
      // They responded with any other value.  Treat this as negotiation to
      // TS07.10.
      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_CONNECTION_STATE_OPENING) {
    RFCOMM_DlcEstablishReq(p_mcb, p_port->dlci, p_port->mtu);
  }
}

/*******************************************************************************
 *
 * Function         PORT_DlcEstablishInd
 *
 * Description      This function is called from the RFCOMM layer when peer
 *                  device wants to establish a new DLC.  If this is not the
 *                  first message in the establishment procedure port_handle
 *                  has a handle to the port control block otherwise the control
 *                  block should be found based on the muliplexer channel and
 *                  dlci.  The block should be allocated before meaning
 *                  that application already made open.
 *
 ******************************************************************************/
void PORT_DlcEstablishInd(tRFC_MCB* p_mcb, uint8_t dlci, uint16_t mtu) {
  tPORT* p_port = port_find_mcb_dlci_port(p_mcb, dlci);

  log::verbose("p_mcb:{}, dlci:{} mtu:{}i, p_port:{}, bd_addr:{}", std::format_ptr(p_mcb), dlci,
               mtu, std::format_ptr(p_port), p_mcb->bd_addr);

  if (!p_port) {
    /* This can be a first request for this port */
    p_port = port_find_dlci_port(dlci);
    if (!p_port) {
      RFCOMM_DlcEstablishRsp(p_mcb, dlci, 0, RFCOMM_ERROR);
      return;
    }
    p_mcb->port_handles[dlci] = p_port->handle;
  }

  /* If L2CAP's mtu less then RFCOMM's take it */
  if (mtu && (mtu < p_port->peer_mtu)) {
    p_port->peer_mtu = mtu;
  }

  /* If there was an inactivity timer running for MCB stop it */
  rfc_timer_stop(p_mcb);

  RFCOMM_DlcEstablishRsp(p_mcb, dlci, p_port->mtu, RFCOMM_SUCCESS);

  /* This is the server side.  If application wants to know when connection */
  /* is established, thats the place */
  if (p_port->p_callback && (p_port->ev_mask & PORT_EV_CONNECTED)) {
    (p_port->p_callback)(PORT_EV_CONNECTED, p_port->handle);
  }

  if (p_port->p_mgmt_callback) {
    p_port->p_mgmt_callback(PORT_SUCCESS, p_port->handle);
    log_counter_metrics(android::bluetooth::CodePathCounterKeyEnum::RFCOMM_CONNECTION_SUCCESS_IND,
                        1);
  }

  p_port->state = PORT_CONNECTION_STATE_OPENED;
}

/*******************************************************************************
 *
 * Function         PORT_DlcEstablishCnf
 *
 * Description      This function is called from the RFCOMM layer when peer
 *                  acknowledges establish procedure (SABME/UA).  Send reply
 *                  to the user and set state to OPENED if result was
 *                  successful.
 *
 ******************************************************************************/
void PORT_DlcEstablishCnf(tRFC_MCB* p_mcb, uint8_t dlci, uint16_t mtu, uint16_t result) {
  tPORT* p_port = port_find_mcb_dlci_port(p_mcb, dlci);

  log::verbose("PORT_DlcEstablishCnf dlci:{} mtu:{} result:{}", dlci, mtu, result);

  if (!p_port) {
    return;
  }

  if (result != RFCOMM_SUCCESS) {
    log::warn("Unable to establish configuration dlci:{} result:{}", dlci, result);
    port_rfc_closed(p_port, PORT_START_FAILED);
    log_counter_metrics(android::bluetooth::CodePathCounterKeyEnum::RFCOMM_PORT_START_FAILED, 1);
    return;
  }

  /* If L2CAP's mtu less then RFCOMM's take it */
  if (mtu && (mtu < p_port->peer_mtu)) {
    p_port->peer_mtu = mtu;
  }

  /* If there was an inactivity timer running for MCB stop it */
  rfc_timer_stop(p_mcb);

  if (p_port->p_callback && (p_port->ev_mask & PORT_EV_CONNECTED)) {
    (p_port->p_callback)(PORT_EV_CONNECTED, p_port->handle);
  }

  if (p_port->p_mgmt_callback) {
    p_port->p_mgmt_callback(PORT_SUCCESS, p_port->handle);
    log_counter_metrics(android::bluetooth::CodePathCounterKeyEnum::RFCOMM_CONNECTION_SUCCESS_CNF,
                        1);
  }
  p_port->state = PORT_CONNECTION_STATE_OPENED;

  /* RPN is required only if we want to tell DTE how the port should be opened
   */
  if ((p_port->uuid == UUID_SERVCLASS_DIALUP_NETWORKING) || (p_port->uuid == UUID_SERVCLASS_FAX)) {
    RFCOMM_PortParameterNegotiationRequest(p_port->rfc.p_mcb, p_port->dlci, NULL);
  } else {
    RFCOMM_ControlReq(p_port->rfc.p_mcb, p_port->dlci, &p_port->local_ctrl);
  }
}

/*******************************************************************************
 *
 * Function         PORT_PortNegInd
 *
 * Description      This function is called from the RFCOMM layer when peer
 *                  device wants to set parameters of the port.  As per the spec
 *                  this message has to be sent before the first data packet
 *                  and can be sent before establish.  The block should be
 *                  allocated before meaning that application already made open.
 *
 ******************************************************************************/
void PORT_PortNegInd(tRFC_MCB* p_mcb, uint8_t dlci, PortSettings* p_settings, uint16_t param_mask) {
  tPORT* p_port = port_find_mcb_dlci_port(p_mcb, dlci);

  log::verbose("PORT_PortNegInd");

  if (!p_port) {
    /* This can be a first request for this port */
    p_port = port_find_dlci_port(dlci);
    if (!p_port) {
      RFCOMM_PortParameterNegotiationResponse(p_mcb, dlci, p_settings, 0);
      return;
    }
    p_mcb->port_handles[dlci] = p_port->handle;
  }

  /* Check if the flow control is acceptable on local side */
  p_port->peer_port_settings = *p_settings;
  RFCOMM_PortParameterNegotiationResponse(p_mcb, dlci, p_settings, param_mask);
}

/*******************************************************************************
 *
 * Function         PORT_PortNegCnf
 *
 * Description      This function is called from the RFCOMM layer to change
 *                  state for the port.  Propagate change to the user.
 *
 ******************************************************************************/
void PORT_PortNegCnf(tRFC_MCB* p_mcb, uint8_t dlci, PortSettings* /* p_settings */,
                     uint16_t result) {
  tPORT* p_port = port_find_mcb_dlci_port(p_mcb, dlci);

  log::verbose("PORT_PortNegCnf");

  if (!p_port) {
    log::warn("PORT_PortNegCnf no port");
    return;
  }
  /* Port negotiation failed. Drop the connection */
  if (result != RFCOMM_SUCCESS) {
    log::warn("Unable to negotiate port state dlci:{} result:{}", dlci, result);
    RFCOMM_DlcReleaseReq(p_mcb, p_port->dlci);

    port_rfc_closed(p_port, PORT_PORT_NEG_FAILED);
    log_counter_metrics(android::bluetooth::CodePathCounterKeyEnum::RFCOMM_PORT_NEG_FAILED, 1);
    return;
  }

  if (!(p_port->port_ctrl & PORT_CTRL_REQ_SENT)) {
    RFCOMM_ControlReq(p_port->rfc.p_mcb, p_port->dlci, &p_port->local_ctrl);
  } else {
    log::warn("PORT_PortNegCnf Control Already sent");
  }
}

/*******************************************************************************
 *
 * Function         PORT_ControlInd
 *
 * Description      This function is called from the RFCOMM layer on the modem
 *                  signal change.  Propagate change to the user.
 *
 ******************************************************************************/
void PORT_ControlInd(tRFC_MCB* p_mcb, uint8_t dlci, tPORT_CTRL* p_pars) {
  tPORT* p_port = port_find_mcb_dlci_port(p_mcb, dlci);
  uint32_t event;
  uint8_t old_signals;

  log::verbose("PORT_ControlInd");

  if (!p_port) {
    return;
  }

  old_signals = p_port->peer_ctrl.modem_signal;

  event = port_get_signal_changes(p_port, old_signals, p_pars->modem_signal);

  p_port->peer_ctrl = *p_pars;

  if (!(p_port->port_ctrl & PORT_CTRL_REQ_SENT)) {
    RFCOMM_ControlReq(p_port->rfc.p_mcb, p_port->dlci, &p_port->local_ctrl);
  } else {
    /* If this is the first time we received control RFCOMM is connected */
    if (!(p_port->port_ctrl & PORT_CTRL_IND_RECEIVED)) {
      event |= (PORT_EV_CONNECTED & p_port->ev_mask);
    }

    if (p_port->port_ctrl & PORT_CTRL_REQ_CONFIRMED) {
      event |= port_rfc_send_tx_data(p_port);
    }
  }

  p_port->port_ctrl |= (PORT_CTRL_IND_RECEIVED | PORT_CTRL_IND_RESPONDED);

  if (p_pars->break_signal) {
    event |= (PORT_EV_BREAK & p_port->ev_mask);
  }

  /* execute call back function only if the application is registered for events
   */
  if (event && p_port->p_callback) {
    (p_port->p_callback)(event, p_port->handle);
  }

  log::verbose("PORT_ControlInd DTR_DSR : {}, RTS_CTS : {}, RI : {}, DCD : {}",
               (p_port->peer_ctrl.modem_signal & MODEM_SIGNAL_DTRDSR) ? 1 : 0,
               (p_port->peer_ctrl.modem_signal & MODEM_SIGNAL_RTSCTS) ? 1 : 0,
               (p_port->peer_ctrl.modem_signal & MODEM_SIGNAL_RI) ? 1 : 0,
               (p_port->peer_ctrl.modem_signal & MODEM_SIGNAL_DCD) ? 1 : 0);
}

/*******************************************************************************
 *
 * Function         PORT_ControlCnf
 *
 * Description      This function is called from the RFCOMM layer when
 *                  peer acknowleges change of the modem signals.
 *
 ******************************************************************************/
void PORT_ControlCnf(tRFC_MCB* p_mcb, uint8_t dlci, tPORT_CTRL* /* p_pars */) {
  tPORT* p_port = port_find_mcb_dlci_port(p_mcb, dlci);
  uint32_t event = 0;

  log::verbose("PORT_ControlCnf");

  if (!p_port) {
    return;
  }

  if (!(p_port->port_ctrl & PORT_CTRL_REQ_CONFIRMED)) {
    p_port->port_ctrl |= PORT_CTRL_REQ_CONFIRMED;

    if (p_port->port_ctrl & PORT_CTRL_IND_RECEIVED) {
      event = (p_port->ev_mask & PORT_EV_CONNECTED);
    }
  }

  if (p_port->port_ctrl & PORT_CTRL_IND_RECEIVED) {
    event |= port_rfc_send_tx_data(p_port);
  }

  /* execute call back function only if the application is registered for events
   */
  if (event && p_port->p_callback) {
    (p_port->p_callback)(event, p_port->handle);
  }
}

/*******************************************************************************
 *
 * Function         PORT_LineStatusInd
 *
 * Description      This function is called from the RFCOMM layer when
 *                  peer indicates change in the line status
 *
 ******************************************************************************/
void PORT_LineStatusInd(tRFC_MCB* p_mcb, uint8_t dlci, uint8_t line_status) {
  tPORT* p_port = port_find_mcb_dlci_port(p_mcb, dlci);
  uint32_t event = 0;

  log::verbose("PORT_LineStatusInd");

  if (!p_port) {
    return;
  }

  p_port->line_status |= line_status;

  if (line_status & PORT_ERR_OVERRUN) {
    event |= PORT_EV_OVERRUN;
  }

  if (line_status & PORT_ERR_BREAK) {
    event |= PORT_EV_BREAK;
  }

  if (line_status & ~(PORT_ERR_OVERRUN | PORT_ERR_BREAK)) {
    event |= PORT_EV_ERR;
  }

  if ((p_port->p_callback != NULL) && (p_port->ev_mask & event)) {
    p_port->p_callback((p_port->ev_mask & event), p_port->handle);
  }
}

/*******************************************************************************
 *
 * Function         PORT_DlcReleaseInd
 *
 * Description      This function is called from the RFCOMM layer when
 *                  DLC connection is released.
 *
 ******************************************************************************/
void PORT_DlcReleaseInd(tRFC_MCB* p_mcb, uint8_t dlci) {
  log::verbose("dlci:{}, bd_addr:{}", dlci, p_mcb->bd_addr);
  tPORT* p_port = port_find_mcb_dlci_port(p_mcb, dlci);
  if (!p_port) {
    return;
  }
  port_rfc_closed(p_port, PORT_CLOSED);
  log_counter_metrics(android::bluetooth::CodePathCounterKeyEnum::RFCOMM_PORT_CLOSED, 1);
}

/*******************************************************************************
 *
 * Function         PORT_CloseInd
 *
 * Description      This function is called from the RFCOMM layer when
 *                  multiplexer connection is released.
 *
 ******************************************************************************/
void PORT_CloseInd(tRFC_MCB* p_mcb) {
  tPORT* p_port;
  int i;

  log::verbose("PORT_CloseInd");

  p_port = &rfc_cb.port.port[0];
  for (i = 0; i < MAX_RFC_PORTS; i++, p_port++) {
    if (p_port->rfc.p_mcb == p_mcb) {
      port_rfc_closed(p_port, PORT_PEER_CONNECTION_FAILED);
      log_counter_metrics(
              android::bluetooth::CodePathCounterKeyEnum::RFCOMM_PORT_PEER_CONNECTION_FAILED, 1);
    }
  }
  rfc_release_multiplexer_channel(p_mcb);
}

/*******************************************************************************
 *
 * Function         PORT_TimeOutCloseMux
 *
 * Description      This function is called when RFCOMM timesout on a command
 *                  as a result multiplexer connection is closed.
 *
 ******************************************************************************/
void PORT_TimeOutCloseMux(tRFC_MCB* p_mcb) {
  tPORT* p_port;
  int i;

  log::verbose("PORT_TimeOutCloseMux");

  p_port = &rfc_cb.port.port[0];
  for (i = 0; i < MAX_RFC_PORTS; i++, p_port++) {
    if (p_port->rfc.p_mcb == p_mcb) {
      port_rfc_closed(p_port, PORT_PEER_TIMEOUT);
      log_counter_metrics(android::bluetooth::CodePathCounterKeyEnum::RFCOMM_PORT_PEER_TIMEOUT, 1);
    }
  }
}

/*******************************************************************************
 *
 * Function         PORT_DataInd
 *
 * Description      This function is called from the RFCOMM layer when data
 *                  buffer is received from the peer.
 *
 ******************************************************************************/
void PORT_DataInd(tRFC_MCB* p_mcb, uint8_t dlci, BT_HDR* p_buf) {
  tPORT* p_port = port_find_mcb_dlci_port(p_mcb, dlci);
  uint8_t rx_char1;
  uint32_t events = 0;
  uint8_t* p;
  int i;

  log::verbose("PORT_DataInd with data length {}, p_mcb:{},p_port:{},dlci:{}", p_buf->len,
               std::format_ptr(p_mcb), std::format_ptr(p_port), dlci);
  if (!p_port) {
    osi_free(p_buf);
    return;
  }
  /* If client registered callout callback with flow control we can just deliver
   * receive data */
  if (p_port->p_data_co_callback) {
    /* Another packet is delivered to user.  Send credits to peer if required */
    if (p_port->p_data_co_callback(p_port->handle, (uint8_t*)p_buf, -1,
                                   DATA_CO_CALLBACK_TYPE_INCOMING)) {
      port_flow_control_peer(p_port, true, 1);
    } else {
      port_flow_control_peer(p_port, false, 0);
    }
    // osi_free(p_buf);
    return;
  }
  /* If client registered callback we can just deliver receive data */
  if (p_port->p_data_callback) {
    /* Another packet is delivered to user.  Send credits to peer if required */
    port_flow_control_peer(p_port, true, 1);
    p_port->p_data_callback(p_port->handle, (uint8_t*)(p_buf + 1) + p_buf->offset, p_buf->len);
    osi_free(p_buf);
    return;
  }
  /* Check if rx queue exceeds the limit */
  if ((p_port->rx.queue_size + p_buf->len > PORT_RX_CRITICAL_WM) ||
      (fixed_queue_length(p_port->rx.queue) + 1 > p_port->rx_buf_critical)) {
    log::verbose("PORT_DataInd. Buffer over run. Dropping the buffer");
    osi_free(p_buf);
    RFCOMM_LineStatusReq(p_mcb, dlci, LINE_STATUS_OVERRUN);
    return;
  }
  /* If user registered to receive notification when a particular byte is */
  /* received we mast check all received bytes */
  if (((rx_char1 = p_port->user_port_settings.rx_char1) != 0) &&
      (p_port->ev_mask & PORT_EV_RXFLAG)) {
    for (i = 0, p = (uint8_t*)(p_buf + 1) + p_buf->offset; i < p_buf->len; i++) {
      if (*p++ == rx_char1) {
        events |= PORT_EV_RXFLAG;
        break;
      }
    }
  }

  mutex_global_lock();

  fixed_queue_enqueue(p_port->rx.queue, p_buf);
  p_port->rx.queue_size += p_buf->len;

  mutex_global_unlock();

  /* perform flow control procedures if necessary */
  port_flow_control_peer(p_port, false, 0);

  /* If user indicated flow control can not deliver any notifications to them */
  if (p_port->rx.user_fc) {
    if (events & PORT_EV_RXFLAG) {
      p_port->rx_flag_ev_pending = true;
    }
    return;
  }

  events |= PORT_EV_RXCHAR;

  /* Mask out all events that are not of interest to user */
  events &= p_port->ev_mask;

  if (p_port->p_callback && events) {
    p_port->p_callback(events, p_port->handle);
  }
}

/*******************************************************************************
 *
 * Function         PORT_FlowInd
 *
 * Description      This function is called from the RFCOMM layer on the flow
 *                  control signal change.  Propagate change to the user.
 *
 ******************************************************************************/
void PORT_FlowInd(tRFC_MCB* p_mcb, uint8_t dlci, bool enable_data) {
  tPORT* p_port = (tPORT*)NULL;
  uint32_t events = 0;
  int i;

  log::verbose("PORT_FlowInd fc:{}", enable_data);

  if (dlci == 0) {
    p_mcb->peer_ready = enable_data;
  } else {
    p_port = port_find_mcb_dlci_port(p_mcb, dlci);
    if (p_port == NULL) {
      return;
    }

    p_port->tx.peer_fc = !enable_data;
  }

  for (i = 0; i < MAX_RFC_PORTS; i++) {
    /* If DLCI is 0 event applies to all ports */
    if (dlci == 0) {
      p_port = &rfc_cb.port.port[i];
      if (!p_port->in_use || (p_port->rfc.p_mcb != p_mcb) ||
          (p_port->rfc.state != RFC_STATE_OPENED)) {
        continue;
      }
    }
    events = 0;

    /* Check if flow of data is still enabled */
    events |= port_flow_control_user(p_port);

    /* Check if data can be sent and send it */
    events |= port_rfc_send_tx_data(p_port);

    /* Mask out all events that are not of interest to user */
    events &= p_port->ev_mask;

    /* Send event to the application */
    if (p_port->p_callback && events) {
      (p_port->p_callback)(events, p_port->handle);
    }

    /* If DLCI is not 0 event applies to one port only */
    if (dlci != 0) {
      break;
    }
  }
}

/*******************************************************************************
 *
 * Function         port_rfc_send_tx_data
 *
 * Description      This function is when forward data can be sent to the peer
 *
 ******************************************************************************/
uint32_t port_rfc_send_tx_data(tPORT* p_port) {
  uint32_t events = 0;
  BT_HDR* p_buf;

  /* if there is data to be sent */
  if (p_port->tx.queue_size > 0) {
    /* while the rfcomm peer is not flow controlling us, and peer is ready */
    while (!p_port->tx.peer_fc && p_port->rfc.p_mcb && p_port->rfc.p_mcb->peer_ready) {
      /* get data from tx queue and send it */
      mutex_global_lock();

      p_buf = (BT_HDR*)fixed_queue_try_dequeue(p_port->tx.queue);
      if (p_buf != NULL) {
        p_port->tx.queue_size -= p_buf->len;

        mutex_global_unlock();

        log::verbose("Sending RFCOMM_DataReq tx.queue_size={}", p_port->tx.queue_size);

        RFCOMM_DataReq(p_port->rfc.p_mcb, p_port->dlci, p_buf);

        events |= PORT_EV_TXCHAR;

        if (p_port->tx.queue_size == 0) {
          events |= PORT_EV_TXEMPTY;
          break;
        }
      } else {
        /* queue is empty-- all data sent */
        mutex_global_unlock();

        events |= PORT_EV_TXEMPTY;
        break;
      }
    }
    /* If we flow controlled user based on the queue size enable data again */
    events |= port_flow_control_user(p_port);
  }
  return events & p_port->ev_mask;
}

/*******************************************************************************
 *
 * Function         port_rfc_closed
 *
 * Description      Called when RFCOMM port is closed
 *
 ******************************************************************************/
void port_rfc_closed(tPORT* p_port, uint8_t res) {
  uint8_t old_signals;
  uint32_t events = 0;
  tRFC_MCB* p_mcb = p_port->rfc.p_mcb;

  if ((p_port->state == PORT_CONNECTION_STATE_OPENING) && (p_port->is_server)) {
    /* The server side was not informed that connection is up, ignore */
    log::warn("port_rfc_closed in OPENING state ignored");

    rfc_port_timer_stop(p_port);
    p_port->rfc.state = RFC_STATE_CLOSED;

    if (p_mcb) {
      p_mcb->port_handles[p_port->dlci] = 0;

      /* If there are no more ports opened on this MCB release it */
      rfc_check_mcb_active(p_mcb);
      p_port->rfc.p_mcb = NULL;
    }

    /* Need to restore DLCI to listening state
     * if the server was on the initiating RFC
     */
    p_port->dlci &= 0xfe;

    return;
  }

  if (p_port->state >= PORT_CONNECTION_STATE_OPENED && p_mcb) {
    uint16_t lcid;
    tL2C_CCB* ccb;

    lcid = p_mcb->lcid;
    ccb = l2cu_find_ccb_by_cid(nullptr, lcid);

    if (ccb) {
      bluetooth::shim::GetSnoopLogger()->SetRfcommPortClose(ccb->p_lcb->Handle(), lcid,
                                                            p_port->dlci, p_port->uuid);
    }
  }

  if ((p_port->state != PORT_CONNECTION_STATE_CLOSING) &&
      (p_port->state != PORT_CONNECTION_STATE_CLOSED)) {
    p_port->line_status |= LINE_STATUS_FAILED;

    old_signals = p_port->peer_ctrl.modem_signal;

    p_port->peer_ctrl.modem_signal &= ~(PORT_DTRDSR_ON | PORT_CTSRTS_ON | PORT_DCD_ON);

    events |= port_get_signal_changes(p_port, old_signals, p_port->peer_ctrl.modem_signal);

    if (p_port->ev_mask & PORT_EV_CONNECT_ERR) {
      events |= PORT_EV_CONNECT_ERR;
    }
  }

  if ((p_port->p_callback != NULL) && events) {
    p_port->p_callback(events, p_port->handle);
  }

  if (p_port->p_mgmt_callback) {
    uint32_t res2 = res;
    if (res2 >= PORT_ERR_MAX) {
      res2 = PORT_ERR_MAX;
    }
    p_port->p_mgmt_callback(static_cast<tPORT_RESULT>(res2), p_port->handle);
  }

  p_port->rfc.state = RFC_STATE_CLOSED;

  log::info(
          "RFCOMM connection closed, index={}, state={}, reason={}[{}], "
          "UUID=0x{:x}, bd_addr={}, is_server={}",
          p_port->handle, p_port->state, PORT_GetResultString(res), res, p_port->uuid,
          p_port->bd_addr, p_port->is_server);

  port_release_port(p_port);
}

/*******************************************************************************
 *
 * Function         port_get_credits
 *
 * Description      Set initial values for credits.
 *                  Adjust max number of rx credits based on negotiated MTU.
 *                  Check max allowed num of bytes, max allowed num buffers,
 *                  should be less then 255
 *
 ******************************************************************************/
void port_get_credits(tPORT* p_port, uint8_t k) {
  p_port->credit_tx = k;
  if (p_port->credit_tx == 0) {
    p_port->tx.peer_fc = true;
  }
}