path: root/stack/l2cap/l2c_int.h

/******************************************************************************
 *
 *  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 file contains L2CAP internal definitions
 *
 ******************************************************************************/
#ifndef L2C_INT_H
#define L2C_INT_H

#include <stdbool.h>

#include "bt_common.h"
#include "btm_api.h"
#include "btm_ble_api.h"
#include "l2c_api.h"
#include "l2cdefs.h"
#include "osi/include/alarm.h"
#include "osi/include/fixed_queue.h"
#include "osi/include/list.h"

#define L2CAP_MIN_MTU 48 /* Minimum acceptable MTU is 48 bytes */

/* LE credit based L2CAP connection parameters */
constexpr uint16_t L2CAP_LE_MIN_MTU = 23;  // Minimum SDU size
constexpr uint16_t L2CAP_LE_MIN_MPS = 23;
constexpr uint16_t L2CAP_LE_MAX_MPS = 65533;
constexpr uint16_t L2CAP_LE_CREDIT_MAX = 65535;

// This is initial amout of credits we send, and amount to which we increase
// credits once they fall below threshold
constexpr uint16_t L2CAP_LE_CREDIT_DEFAULT = 0xffff;

// If credit count on remote fall below this value, we send back credits to
// reach default value.
constexpr uint16_t L2CAP_LE_CREDIT_THRESHOLD = 0x0040;

static_assert(L2CAP_LE_CREDIT_THRESHOLD < L2CAP_LE_CREDIT_DEFAULT,
              "Threshold must be smaller then default credits");

#define L2CAP_NO_IDLE_TIMEOUT 0xFFFF

/*
 * Timeout values (in milliseconds).
 */
#define L2CAP_LINK_ROLE_SWITCH_TIMEOUT_MS (10 * 1000)  /* 10 seconds */
#define L2CAP_LINK_CONNECT_TIMEOUT_MS (60 * 1000)      /* 30 seconds */
#define L2CAP_LINK_CONNECT_EXT_TIMEOUT_MS (120 * 1000) /* 120 seconds */
#define L2CAP_ECHO_RSP_TIMEOUT_MS (30 * 1000)          /* 30 seconds */
#define L2CAP_LINK_FLOW_CONTROL_TIMEOUT_MS (2 * 1000)  /* 2 seconds */
#define L2CAP_LINK_DISCONNECT_TIMEOUT_MS (30 * 1000)   /* 30 seconds */
#define L2CAP_CHNL_CONNECT_TIMEOUT_MS (60 * 1000)      /* 60 seconds */
#define L2CAP_CHNL_CONNECT_EXT_TIMEOUT_MS (120 * 1000) /* 120 seconds */
#define L2CAP_CHNL_CFG_TIMEOUT_MS (30 * 1000)          /* 30 seconds */
#define L2CAP_CHNL_DISCONNECT_TIMEOUT_MS (10 * 1000)   /* 10 seconds */
#define L2CAP_DELAY_CHECK_SM4_TIMEOUT_MS (2 * 1000)    /* 2 seconds */
#define L2CAP_WAIT_INFO_RSP_TIMEOUT_MS (3 * 1000)      /* 3 seconds */
#define L2CAP_BLE_LINK_CONNECT_TIMEOUT_MS (30 * 1000)  /* 30 seconds */
#define L2CAP_FCR_ACK_TIMEOUT_MS 200                   /* 200 milliseconds */

/* Define the possible L2CAP channel states. The names of
 * the states may seem a bit strange, but they are taken from
 * the Bluetooth specification.
*/
typedef enum {
  CST_CLOSED,                  /* Channel is in closed state */
  CST_ORIG_W4_SEC_COMP,        /* Originator waits security clearence */
  CST_TERM_W4_SEC_COMP,        /* Acceptor waits security clearence */
  CST_W4_L2CAP_CONNECT_RSP,    /* Waiting for peer conenct response */
  CST_W4_L2CA_CONNECT_RSP,     /* Waiting for upper layer connect rsp */
  CST_CONFIG,                  /* Negotiating configuration */
  CST_OPEN,                    /* Data transfer state */
  CST_W4_L2CAP_DISCONNECT_RSP, /* Waiting for peer disconnect rsp */
  CST_W4_L2CA_DISCONNECT_RSP   /* Waiting for upper layer disc rsp */
} tL2C_CHNL_STATE;

/* Define the possible L2CAP link states
*/
typedef enum {
  LST_DISCONNECTED,
  LST_CONNECT_HOLDING,
  LST_CONNECTING_WAIT_SWITCH,
  LST_CONNECTING,
  LST_CONNECTED,
  LST_DISCONNECTING
} tL2C_LINK_STATE;

/* Define input events to the L2CAP link and channel state machines. The names
 * of the events may seem a bit strange, but they are taken from
 * the Bluetooth specification.
*/
/* Lower layer */
#define L2CEVT_LP_CONNECT_CFM 0       /* connect confirm */
#define L2CEVT_LP_CONNECT_CFM_NEG 1   /* connect confirm (failed) */
#define L2CEVT_LP_CONNECT_IND 2       /* connect indication */
#define L2CEVT_LP_DISCONNECT_IND 3    /* disconnect indication */
#define L2CEVT_LP_QOS_CFM 4           /* QOS confirmation */
#define L2CEVT_LP_QOS_CFM_NEG 5       /* QOS confirmation (failed)*/
#define L2CEVT_LP_QOS_VIOLATION_IND 6 /* QOS violation indication */

/* Security */
#define L2CEVT_SEC_COMP 7     /* cleared successfully */
#define L2CEVT_SEC_COMP_NEG 8 /* procedure failed */

/* Peer connection */
#define L2CEVT_L2CAP_CONNECT_REQ 10     /* request */
#define L2CEVT_L2CAP_CONNECT_RSP 11     /* response */
#define L2CEVT_L2CAP_CONNECT_RSP_PND 12 /* response pending */
#define L2CEVT_L2CAP_CONNECT_RSP_NEG 13 /* response (failed) */

/* Peer configuration */
#define L2CEVT_L2CAP_CONFIG_REQ 14     /* request */
#define L2CEVT_L2CAP_CONFIG_RSP 15     /* response */
#define L2CEVT_L2CAP_CONFIG_RSP_NEG 16 /* response (failed) */

#define L2CEVT_L2CAP_DISCONNECT_REQ 17 /* Peer disconnect request */
#define L2CEVT_L2CAP_DISCONNECT_RSP 18 /* Peer disconnect response */
#define L2CEVT_L2CAP_INFO_RSP 19       /* Peer information response */
#define L2CEVT_L2CAP_DATA 20           /* Peer data */

/* Upper layer */
#define L2CEVT_L2CA_CONNECT_REQ 21     /* connect request */
#define L2CEVT_L2CA_CONNECT_RSP 22     /* connect response */
#define L2CEVT_L2CA_CONNECT_RSP_NEG 23 /* connect response (failed)*/
#define L2CEVT_L2CA_CONFIG_REQ 24      /* config request */
#define L2CEVT_L2CA_CONFIG_RSP 25      /* config response */
#define L2CEVT_L2CA_CONFIG_RSP_NEG 26  /* config response (failed) */
#define L2CEVT_L2CA_DISCONNECT_REQ 27  /* disconnect request */
#define L2CEVT_L2CA_DISCONNECT_RSP 28  /* disconnect response */
#define L2CEVT_L2CA_DATA_READ 29       /* data read */
#define L2CEVT_L2CA_DATA_WRITE 30      /* data write */
#define L2CEVT_L2CA_FLUSH_REQ 31       /* flush */

#define L2CEVT_TIMEOUT 32         /* Timeout */
#define L2CEVT_SEC_RE_SEND_CMD 33 /* btm_sec has enough info to proceed */

#define L2CEVT_ACK_TIMEOUT 34 /* RR delay timeout */

#define L2CEVT_L2CA_SEND_FLOW_CONTROL_CREDIT                                  \
  35                                             /* Upper layer credit packet \
                                                    */
#define L2CEVT_L2CAP_RECV_FLOW_CONTROL_CREDIT 36 /* Peer credit packet */

/* Constants for LE Dynamic PSM values */
#define LE_DYNAMIC_PSM_START 0x0080
#define LE_DYNAMIC_PSM_END 0x00FF
#define LE_DYNAMIC_PSM_RANGE (LE_DYNAMIC_PSM_END - LE_DYNAMIC_PSM_START + 1)

/* Bitmask to skip over Broadcom feature reserved (ID) to avoid sending two
   successive ID values, '0' id only or both */
#define L2CAP_ADJ_BRCM_ID 0x1
#define L2CAP_ADJ_ZERO_ID 0x2
#define L2CAP_ADJ_ID 0x3

/* Return values for l2cu_process_peer_cfg_req() */
#define L2CAP_PEER_CFG_UNACCEPTABLE 0
#define L2CAP_PEER_CFG_OK 1
#define L2CAP_PEER_CFG_DISCONNECT 2

/* eL2CAP option constants */
/* Min retransmission timeout if no flush timeout or PBF */
#define L2CAP_MIN_RETRANS_TOUT 2000
/* Min monitor timeout if no flush timeout or PBF */
#define L2CAP_MIN_MONITOR_TOUT 12000

#define L2CAP_MAX_FCR_CFG_TRIES 2 /* Config attempts before disconnecting */

typedef uint8_t tL2C_BLE_FIXED_CHNLS_MASK;

typedef struct {
  uint8_t next_tx_seq;       /* Next sequence number to be Tx'ed */
  uint8_t last_rx_ack;       /* Last sequence number ack'ed by the peer */
  uint8_t next_seq_expected; /* Next peer sequence number expected */
  uint8_t last_ack_sent;     /* Last peer sequence number ack'ed */
  uint8_t num_tries;         /* Number of retries to send a packet */
  uint8_t max_held_acks;     /* Max acks we can hold before sending */

  bool remote_busy; /* true if peer has flowed us off */
  bool local_busy;  /* true if we have flowed off the peer */

  bool rej_sent;       /* Reject was sent */
  bool srej_sent;      /* Selective Reject was sent */
  bool wait_ack;       /* Transmitter is waiting ack (poll sent) */
  bool rej_after_srej; /* Send a REJ when SREJ clears */

  bool send_f_rsp; /* We need to send an F-bit response */

  uint16_t rx_sdu_len; /* Length of the SDU being received */
  BT_HDR* p_rx_sdu;    /* Buffer holding the SDU being received */
  fixed_queue_t*
      waiting_for_ack_q;          /* Buffers sent and waiting for peer to ack */
  fixed_queue_t* srej_rcv_hold_q; /* Buffers rcvd but held pending SREJ rsp */
  fixed_queue_t* retrans_q;       /* Buffers being retransmitted */

  alarm_t* ack_timer;         /* Timer delaying RR */
  alarm_t* mon_retrans_timer; /* Timer Monitor or Retransmission */

#if (L2CAP_ERTM_STATS == TRUE)
  uint64_t connect_tick_count;  /* Time channel was established */
  uint32_t ertm_pkt_counts[2];  /* Packets sent and received */
  uint32_t ertm_byte_counts[2]; /* Bytes   sent and received */
  uint32_t s_frames_sent[4];    /* S-frames sent (RR, REJ, RNR, SREJ) */
  uint32_t s_frames_rcvd[4];    /* S-frames rcvd (RR, REJ, RNR, SREJ) */
  uint32_t xmit_window_closed;  /* # of times the xmit window was closed */
  uint32_t controller_idle; /* # of times less than 2 packets in controller */
                            /* when the xmit window was closed */
  uint32_t pkts_retransmitted; /* # of packets that were retransmitted */
  uint32_t retrans_touts;      /* # of retransmission timouts */
  uint32_t xmit_ack_touts;     /* # of xmit ack timouts */

#define L2CAP_ERTM_STATS_NUM_AVG 10
#define L2CAP_ERTM_STATS_AVG_NUM_SAMPLES 100
  uint32_t ack_delay_avg_count;
  uint32_t ack_delay_avg_index;
  uint32_t throughput_start;
  uint32_t throughput[L2CAP_ERTM_STATS_NUM_AVG];
  uint32_t ack_delay_avg[L2CAP_ERTM_STATS_NUM_AVG];
  uint32_t ack_delay_min[L2CAP_ERTM_STATS_NUM_AVG];
  uint32_t ack_delay_max[L2CAP_ERTM_STATS_NUM_AVG];
  uint32_t ack_q_count_avg[L2CAP_ERTM_STATS_NUM_AVG];
  uint32_t ack_q_count_min[L2CAP_ERTM_STATS_NUM_AVG];
  uint32_t ack_q_count_max[L2CAP_ERTM_STATS_NUM_AVG];
#endif
} tL2C_FCRB;

typedef struct {
  bool in_use;
  bool log_packets;
  uint16_t psm;
  uint16_t real_psm; /* This may be a dummy RCB for an o/b connection but */
                     /* this is the real PSM that we need to connect to */
  tL2CAP_APPL_INFO api;
} tL2C_RCB;

#ifndef L2CAP_CBB_DEFAULT_DATA_RATE_BUFF_QUOTA
#define L2CAP_CBB_DEFAULT_DATA_RATE_BUFF_QUOTA 100
#endif

typedef void(tL2CAP_SEC_CBACK)(const RawAddress& bd_addr,
                               tBT_TRANSPORT trasnport, void* p_ref_data,
                               tBTM_STATUS result);

typedef struct {
  uint16_t psm;
  tBT_TRANSPORT transport;
  bool is_originator;
  tL2CAP_SEC_CBACK* p_callback;
  void* p_ref_data;
} tL2CAP_SEC_DATA;

/* Define a channel control block (CCB). There may be many channel control
 * blocks between the same two Bluetooth devices (i.e. on the same link).
 * Each CCB has unique local and remote CIDs. All channel control blocks on
 * the same physical link and are chained together.
*/
typedef struct t_l2c_ccb {
  bool in_use;                /* true when in use, false when not */
  tL2C_CHNL_STATE chnl_state; /* Channel state */
  tL2CAP_LE_CFG_INFO
      local_conn_cfg; /* Our config for ble conn oriented channel */
  tL2CAP_LE_CFG_INFO
      peer_conn_cfg;       /* Peer device config ble conn oriented channel */
  bool is_first_seg;       /* Dtermine whether the received packet is the first
                              segment or not */
  BT_HDR* ble_sdu;         /* Buffer for storing unassembled sdu*/
  uint16_t ble_sdu_length; /* Length of unassembled sdu length*/
  struct t_l2c_ccb* p_next_ccb; /* Next CCB in the chain */
  struct t_l2c_ccb* p_prev_ccb; /* Previous CCB in the chain */
  struct t_l2c_linkcb* p_lcb;   /* Link this CCB is assigned to */

  uint16_t local_cid;  /* Local CID */
  uint16_t remote_cid; /* Remote CID */

  alarm_t* l2c_ccb_timer; /* CCB Timer Entry */

  tL2C_RCB* p_rcb;      /* Registration CB for this Channel */
  bool should_free_rcb; /* True if RCB was allocated on the heap */

#define IB_CFG_DONE 0x01
#define OB_CFG_DONE 0x02
#define RECONFIG_FLAG 0x04 /* True after initial configuration */
#define CFG_DONE_MASK (IB_CFG_DONE | OB_CFG_DONE)

  uint8_t config_done; /* Configuration flag word */
  uint8_t local_id;    /* Transaction ID for local trans */
  uint8_t remote_id;   /* Transaction ID for local */

#define CCB_FLAG_NO_RETRY 0x01     /* no more retry */
#define CCB_FLAG_SENT_PENDING 0x02 /* already sent pending response */
  uint8_t flags;

  tL2CAP_CFG_INFO our_cfg;          /* Our saved configuration options */
  tL2CAP_CH_CFG_BITS peer_cfg_bits; /* Store what peer wants to configure */
  tL2CAP_CFG_INFO peer_cfg;         /* Peer's saved configuration options */

  fixed_queue_t* xmit_hold_q; /* Transmit data hold queue */
  bool cong_sent;             /* Set when congested status sent */
  uint16_t buff_quota;        /* Buffer quota before sending congestion */

  tL2CAP_CHNL_PRIORITY ccb_priority;  /* Channel priority */
  tL2CAP_CHNL_DATA_RATE tx_data_rate; /* Channel Tx data rate */
  tL2CAP_CHNL_DATA_RATE rx_data_rate; /* Channel Rx data rate */

  /* Fields used for eL2CAP */
  tL2CAP_ERTM_INFO ertm_info;
  tL2C_FCRB fcrb;
  uint16_t tx_mps; /* TX MPS adjusted based on current controller */
  uint16_t max_rx_mtu;
  uint8_t fcr_cfg_tries;          /* Max number of negotiation attempts */
  bool peer_cfg_already_rejected; /* If mode rejected once, set to true */
  bool out_cfg_fcr_present; /* true if cfg response shoulkd include fcr options
                               */

#define L2CAP_CFG_FCS_OUR 0x01  /* Our desired config FCS option */
#define L2CAP_CFG_FCS_PEER 0x02 /* Peer's desired config FCS option */
#define L2CAP_BYPASS_FCS (L2CAP_CFG_FCS_OUR | L2CAP_CFG_FCS_PEER)
  uint8_t bypass_fcs;

#if (L2CAP_NON_FLUSHABLE_PB_INCLUDED == TRUE)
  bool is_flushable; /* true if channel is flushable */
#endif

#if (L2CAP_NUM_FIXED_CHNLS > 0)
  uint16_t fixed_chnl_idle_tout; /* Idle timeout to use for the fixed channel */
#endif
  uint16_t tx_data_len;

  /* Number of LE frames that the remote can send to us (credit count in
   * remote). Valid only for LE CoC */
  uint16_t remote_credit_count;
} tL2C_CCB;

/***********************************************************************
 * Define a queue of linked CCBs.
*/
typedef struct {
  tL2C_CCB* p_first_ccb; /* The first channel in this queue */
  tL2C_CCB* p_last_ccb;  /* The last  channel in this queue */
} tL2C_CCB_Q;

#if (L2CAP_ROUND_ROBIN_CHANNEL_SERVICE == TRUE)

/* Round-Robin service for the same priority channels */
#define L2CAP_NUM_CHNL_PRIORITY \
  3 /* Total number of priority group (high, medium, low)*/
#define L2CAP_CHNL_PRIORITY_WEIGHT \
  5 /* weight per priority for burst transmission quota */
#define L2CAP_GET_PRIORITY_QUOTA(pri) \
  ((L2CAP_NUM_CHNL_PRIORITY - (pri)) * L2CAP_CHNL_PRIORITY_WEIGHT)

/* CCBs within the same LCB are served in round robin with priority It will make
 * sure that low priority channel (for example, HF signaling on RFCOMM) can be
 * sent to the headset even if higher priority channel (for example, AV media
 * channel) is congested.
 */

typedef struct {
  tL2C_CCB* p_serve_ccb; /* current serving ccb within priority group */
  tL2C_CCB* p_first_ccb; /* first ccb of priority group */
  uint8_t num_ccb;       /* number of channels in priority group */
  uint8_t quota;         /* burst transmission quota */
} tL2C_RR_SERV;

#endif /* (L2CAP_ROUND_ROBIN_CHANNEL_SERVICE == TRUE) */

/* Define a link control block. There is one link control block between
 * this device and any other device (i.e. BD ADDR).
*/
typedef struct t_l2c_linkcb {
  bool in_use; /* true when in use, false when not */
  tL2C_LINK_STATE link_state;

  alarm_t* l2c_lcb_timer; /* Timer entry for timeout evt */
  uint16_t handle;        /* The handle used with LM */

  tL2C_CCB_Q ccb_queue; /* Queue of CCBs on this LCB */

  tL2C_CCB* p_pending_ccb;  /* ccb of waiting channel during link disconnect */
  alarm_t* info_resp_timer; /* Timer entry for info resp timeout evt */
  RawAddress remote_bd_addr; /* The BD address of the remote */

  uint8_t link_role; /* Master or slave */
  uint8_t id;
  uint8_t cur_echo_id;              /* Current id value for echo request */
  tL2CA_ECHO_RSP_CB* p_echo_rsp_cb; /* Echo response callback */
  uint16_t idle_timeout;            /* Idle timeout */
  bool is_bonding;                  /* True - link active only for bonding */

  uint16_t link_flush_tout; /* Flush timeout used */

  uint16_t link_xmit_quota; /* Num outstanding pkts allowed */
  uint16_t sent_not_acked;  /* Num packets sent but not acked */

  bool partial_segment_being_sent; /* Set true when a partial segment */
                                   /* is being sent. */
  bool w4_info_rsp;                /* true when info request is active */
  uint8_t info_rx_bits;            /* set 1 if received info type */
  uint32_t peer_ext_fea;           /* Peer's extended features mask */
  list_t* link_xmit_data_q;        /* Link transmit data buffer queue */

  uint8_t peer_chnl_mask[L2CAP_FIXED_CHNL_ARRAY_SIZE];

  BT_HDR* p_hcit_rcv_acl;   /* Current HCIT ACL buf being rcvd */
  uint16_t idle_timeout_sv; /* Save current Idle timeout */
  uint8_t acl_priority;     /* L2C_PRIORITY_NORMAL or L2C_PRIORITY_HIGH */
  tL2CA_NOCP_CB* p_nocp_cb; /* Num Cmpl pkts callback */

#if (L2CAP_NUM_FIXED_CHNLS > 0)
  tL2C_CCB* p_fixed_ccbs[L2CAP_NUM_FIXED_CHNLS];
  uint16_t disc_reason;
#endif

  tBT_TRANSPORT transport;
  uint8_t initiating_phys;  // LE PHY used for connection initiation
  tBLE_ADDR_TYPE ble_addr_type;
  uint16_t tx_data_len; /* tx data length used in data length extension */
  fixed_queue_t* le_sec_pending_q; /* LE coc channels waiting for security check
                                      completion */
  uint8_t sec_act;
#define L2C_BLE_CONN_UPDATE_DISABLE \
  0x1                              /* disable update connection parameters */
#define L2C_BLE_NEW_CONN_PARAM 0x2 /* new connection parameter to be set */
#define L2C_BLE_UPDATE_PENDING                  \
  0x4 /* waiting for connection update finished \
         */
#define L2C_BLE_NOT_DEFAULT_PARAM \
  0x8 /* not using default connection parameters */
  uint8_t conn_update_mask;

  uint16_t min_interval; /* parameters as requested by peripheral */
  uint16_t max_interval;
  uint16_t latency;
  uint16_t timeout;
  uint16_t min_ce_len;
  uint16_t max_ce_len;

#if (L2CAP_ROUND_ROBIN_CHANNEL_SERVICE == TRUE)
  /* each priority group is limited burst transmission */
  /* round robin service for the same priority channels */
  tL2C_RR_SERV rr_serv[L2CAP_NUM_CHNL_PRIORITY];
  uint8_t rr_pri; /* current serving priority group */
#endif

} tL2C_LCB;

/* Define the L2CAP control structure
*/
typedef struct {
  uint8_t l2cap_trace_level;
  uint16_t controller_xmit_window; /* Total ACL window for all links */

  uint16_t round_robin_quota;   /* Round-robin link quota */
  uint16_t round_robin_unacked; /* Round-robin unacked */
  bool check_round_robin;       /* Do a round robin check */

  bool is_cong_cback_context;

  tL2C_LCB lcb_pool[MAX_L2CAP_LINKS];    /* Link Control Block pool */
  tL2C_CCB ccb_pool[MAX_L2CAP_CHANNELS]; /* Channel Control Block pool */
  tL2C_RCB rcb_pool[MAX_L2CAP_CLIENTS];  /* Registration info pool */

  tL2C_CCB* p_free_ccb_first; /* Pointer to first free CCB */
  tL2C_CCB* p_free_ccb_last;  /* Pointer to last  free CCB */

  uint8_t
      desire_role; /* desire to be master/slave when accepting a connection */
  bool disallow_switch;     /* false, to allow switch at create conn */
  uint16_t num_lm_acl_bufs; /* # of ACL buffers on controller */
  uint16_t idle_timeout;    /* Idle timeout */

  list_t* rcv_pending_q;       /* Recv pending queue */
  alarm_t* receive_hold_timer; /* Timer entry for rcv hold */

  tL2C_LCB* p_cur_hcit_lcb;  /* Current HCI Transport buffer */
  uint16_t num_links_active; /* Number of links active */

#if (L2CAP_NON_FLUSHABLE_PB_INCLUDED == TRUE)
  uint16_t non_flushable_pbf; /* L2CAP_PKT_START_NON_FLUSHABLE if controller
                                 supports */
  /* Otherwise, L2CAP_PKT_START */
  bool is_flush_active; /* true if an HCI_Enhanced_Flush has been sent */
#endif

#if (L2CAP_CONFORMANCE_TESTING == TRUE)
  uint32_t test_info_resp; /* Conformance testing needs a dynamic response */
#endif

#if (L2CAP_NUM_FIXED_CHNLS > 0)
  tL2CAP_FIXED_CHNL_REG
      fixed_reg[L2CAP_NUM_FIXED_CHNLS]; /* Reg info for fixed channels */
#endif

  uint16_t num_ble_links_active; /* Number of LE links active */
  uint16_t controller_le_xmit_window; /* Total ACL window for all links */
  tL2C_BLE_FIXED_CHNLS_MASK l2c_ble_fixed_chnls_mask;  // LE fixed channels mask
  uint16_t num_lm_ble_bufs;         /* # of ACL buffers on controller */
  uint16_t ble_round_robin_quota;   /* Round-robin link quota */
  uint16_t ble_round_robin_unacked; /* Round-robin unacked */
  bool ble_check_round_robin;       /* Do a round robin check */
  tL2C_RCB ble_rcb_pool[BLE_MAX_L2CAP_CLIENTS]; /* Registration info pool */

  tL2CA_ECHO_DATA_CB* p_echo_data_cb; /* Echo data callback */

#if (L2CAP_HIGH_PRI_CHAN_QUOTA_IS_CONFIGURABLE == TRUE)
  uint16_t high_pri_min_xmit_quota; /* Minimum number of ACL credit for high
                                       priority link */
#endif /* (L2CAP_HIGH_PRI_CHAN_QUOTA_IS_CONFIGURABLE == TRUE) */

  uint16_t dyn_psm;

  uint16_t le_dyn_psm; /* Next LE dynamic PSM value to try to assign */
  bool le_dyn_psm_assigned[LE_DYNAMIC_PSM_RANGE]; /* Table of assigned LE PSM */

} tL2C_CB;

/* Define a structure that contains the information about a connection.
 * This structure is used to pass between functions, and not all the
 * fields will always be filled in.
*/
typedef struct {
  RawAddress bd_addr;    /* Remote BD address */
  uint8_t status;        /* Connection status */
  uint16_t psm;          /* PSM of the connection */
  uint16_t l2cap_result; /* L2CAP result */
  uint16_t l2cap_status; /* L2CAP status */
  uint16_t remote_cid;   /* Remote CID */
} tL2C_CONN_INFO;

typedef void(tL2C_FCR_MGMT_EVT_HDLR)(uint8_t, tL2C_CCB*);

/* Necessary info for postponed TX completion callback
*/
typedef struct {
  uint16_t local_cid;
  uint16_t num_sdu;
  tL2CA_TX_COMPLETE_CB* cb;
} tL2C_TX_COMPLETE_CB_INFO;

/* The offset in a buffer that L2CAP will use when building commands.
*/
#define L2CAP_SEND_CMD_OFFSET 0

/* Number of ACL buffers to use for high priority channel
*/
#if (L2CAP_HIGH_PRI_CHAN_QUOTA_IS_CONFIGURABLE == FALSE)
#define L2CAP_HIGH_PRI_MIN_XMIT_QUOTA_A (L2CAP_HIGH_PRI_MIN_XMIT_QUOTA)
#else
#define L2CAP_HIGH_PRI_MIN_XMIT_QUOTA_A (l2cb.high_pri_min_xmit_quota)
#endif

/* L2CAP global data
 ***********************************
*/
extern tL2C_CB l2cb;

/* Functions provided by l2c_main.cc
 ***********************************
*/
void l2c_init(void);
void l2c_free(void);

extern void l2c_receive_hold_timer_timeout(void* data);
extern void l2c_ccb_timer_timeout(void* data);
extern void l2c_lcb_timer_timeout(void* data);
extern void l2c_fcrb_ack_timer_timeout(void* data);
extern uint8_t l2c_data_write(uint16_t cid, BT_HDR* p_data, uint16_t flag);
extern void l2c_rcv_acl_data(BT_HDR* p_msg);
extern void l2c_process_held_packets(bool timed_out);

/* Functions provided by l2c_utils.cc
 ***********************************
*/
extern bool l2cu_can_allocate_lcb(void);
extern tL2C_LCB* l2cu_allocate_lcb(const RawAddress& p_bd_addr, bool is_bonding,
                                   tBT_TRANSPORT transport);
extern bool l2cu_start_post_bond_timer(uint16_t handle);
extern void l2cu_release_lcb(tL2C_LCB* p_lcb);
extern tL2C_LCB* l2cu_find_lcb_by_bd_addr(const RawAddress& p_bd_addr,
                                          tBT_TRANSPORT transport);
extern tL2C_LCB* l2cu_find_lcb_by_handle(uint16_t handle);
extern void l2cu_update_lcb_4_bonding(const RawAddress& p_bd_addr,
                                      bool is_bonding);

extern uint8_t l2cu_get_conn_role(tL2C_LCB* p_this_lcb);
extern bool l2cu_set_acl_priority(const RawAddress& bd_addr, uint8_t priority,
                                  bool reset_after_rs);

extern void l2cu_enqueue_ccb(tL2C_CCB* p_ccb);
extern void l2cu_dequeue_ccb(tL2C_CCB* p_ccb);
extern void l2cu_change_pri_ccb(tL2C_CCB* p_ccb, tL2CAP_CHNL_PRIORITY priority);

extern tL2C_CCB* l2cu_allocate_ccb(tL2C_LCB* p_lcb, uint16_t cid);
extern void l2cu_release_ccb(tL2C_CCB* p_ccb);
extern tL2C_CCB* l2cu_find_ccb_by_cid(tL2C_LCB* p_lcb, uint16_t local_cid);
extern tL2C_CCB* l2cu_find_ccb_by_remote_cid(tL2C_LCB* p_lcb,
                                             uint16_t remote_cid);
extern void l2cu_adj_id(tL2C_LCB* p_lcb, uint8_t adj_mask);
extern bool l2c_is_cmd_rejected(uint8_t cmd_code, uint8_t id, tL2C_LCB* p_lcb);

extern void l2cu_send_peer_cmd_reject(tL2C_LCB* p_lcb, uint16_t reason,
                                      uint8_t rem_id, uint16_t p1, uint16_t p2);
extern void l2cu_send_peer_connect_req(tL2C_CCB* p_ccb);
extern void l2cu_send_peer_connect_rsp(tL2C_CCB* p_ccb, uint16_t result,
                                       uint16_t status);
extern void l2cu_send_peer_config_req(tL2C_CCB* p_ccb, tL2CAP_CFG_INFO* p_cfg);
extern void l2cu_send_peer_config_rsp(tL2C_CCB* p_ccb, tL2CAP_CFG_INFO* p_cfg);
extern void l2cu_send_peer_config_rej(tL2C_CCB* p_ccb, uint8_t* p_data,
                                      uint16_t data_len, uint16_t rej_len);
extern void l2cu_send_peer_disc_req(tL2C_CCB* p_ccb);
extern void l2cu_send_peer_disc_rsp(tL2C_LCB* p_lcb, uint8_t remote_id,
                                    uint16_t local_cid, uint16_t remote_cid);
extern void l2cu_send_peer_echo_req(tL2C_LCB* p_lcb, uint8_t* p_data,
                                    uint16_t data_len);
extern void l2cu_send_peer_echo_rsp(tL2C_LCB* p_lcb, uint8_t id,
                                    uint8_t* p_data, uint16_t data_len);
extern void l2cu_send_peer_info_rsp(tL2C_LCB* p_lcb, uint8_t id,
                                    uint16_t info_type);
extern void l2cu_reject_connection(tL2C_LCB* p_lcb, uint16_t remote_cid,
                                   uint8_t rem_id, uint16_t result);
extern void l2cu_send_peer_info_req(tL2C_LCB* p_lcb, uint16_t info_type);
extern void l2cu_set_acl_hci_header(BT_HDR* p_buf, tL2C_CCB* p_ccb);
extern void l2cu_check_channel_congestion(tL2C_CCB* p_ccb);
extern void l2cu_disconnect_chnl(tL2C_CCB* p_ccb);

extern void l2cu_tx_complete(tL2C_TX_COMPLETE_CB_INFO* p_cbi);

#if (L2CAP_NON_FLUSHABLE_PB_INCLUDED == TRUE)
extern void l2cu_set_non_flushable_pbf(bool);
#endif

extern void l2cu_send_peer_ble_par_req(tL2C_LCB* p_lcb, uint16_t min_int,
                                       uint16_t max_int, uint16_t latency,
                                       uint16_t timeout);
extern void l2cu_send_peer_ble_par_rsp(tL2C_LCB* p_lcb, uint16_t reason,
                                       uint8_t rem_id);
extern void l2cu_reject_ble_connection(tL2C_LCB* p_lcb, uint8_t rem_id,
                                       uint16_t result);
extern void l2cu_send_peer_ble_credit_based_conn_res(tL2C_CCB* p_ccb,
                                                     uint16_t result);
extern void l2cu_send_peer_ble_credit_based_conn_req(tL2C_CCB* p_ccb);
extern void l2cu_send_peer_ble_flow_control_credit(tL2C_CCB* p_ccb,
                                                   uint16_t credit_value);
extern void l2cu_send_peer_ble_credit_based_disconn_req(tL2C_CCB* p_ccb);

extern bool l2cu_initialize_fixed_ccb(tL2C_LCB* p_lcb, uint16_t fixed_cid,
                                      tL2CAP_FCR_OPTS* p_fcr);
extern void l2cu_no_dynamic_ccbs(tL2C_LCB* p_lcb);
extern void l2cu_process_fixed_chnl_resp(tL2C_LCB* p_lcb);
extern bool l2cu_is_ccb_active(tL2C_CCB* p_ccb);

/* Functions provided for Broadcom Aware
 ***************************************
*/
extern bool l2cu_check_feature_req(tL2C_LCB* p_lcb, uint8_t id, uint8_t* p_data,
                                   uint16_t data_len);
extern void l2cu_check_feature_rsp(tL2C_LCB* p_lcb, uint8_t id, uint8_t* p_data,
                                   uint16_t data_len);
extern void l2cu_send_feature_req(tL2C_CCB* p_ccb);

extern tL2C_RCB* l2cu_allocate_rcb(uint16_t psm);
extern tL2C_RCB* l2cu_find_rcb_by_psm(uint16_t psm);
extern void l2cu_release_rcb(tL2C_RCB* p_rcb);
extern void l2cu_release_ble_rcb(tL2C_RCB* p_rcb);
extern tL2C_RCB* l2cu_allocate_ble_rcb(uint16_t psm);
extern tL2C_RCB* l2cu_find_ble_rcb_by_psm(uint16_t psm);

extern uint8_t l2cu_process_peer_cfg_req(tL2C_CCB* p_ccb,
                                         tL2CAP_CFG_INFO* p_cfg);
extern void l2cu_process_peer_cfg_rsp(tL2C_CCB* p_ccb, tL2CAP_CFG_INFO* p_cfg);
extern void l2cu_process_our_cfg_req(tL2C_CCB* p_ccb, tL2CAP_CFG_INFO* p_cfg);
extern void l2cu_process_our_cfg_rsp(tL2C_CCB* p_ccb, tL2CAP_CFG_INFO* p_cfg);

extern void l2cu_device_reset(void);
extern tL2C_LCB* l2cu_find_lcb_by_state(tL2C_LINK_STATE state);
extern bool l2cu_lcb_disconnecting(void);

extern bool l2cu_create_conn_br_edr(tL2C_LCB* p_lcb);
extern bool l2cu_create_conn_le(tL2C_LCB* p_lcb);
extern bool l2cu_create_conn_le(tL2C_LCB* p_lcb, uint8_t initiating_phys);
extern bool l2cu_create_conn_after_switch(tL2C_LCB* p_lcb);
extern BT_HDR* l2cu_get_next_buffer_to_send(tL2C_LCB* p_lcb,
                                            tL2C_TX_COMPLETE_CB_INFO* p_cbi);
extern void l2cu_resubmit_pending_sec_req(const RawAddress* p_bda);
extern void l2cu_initialize_amp_ccb(tL2C_LCB* p_lcb);
extern void l2cu_adjust_out_mps(tL2C_CCB* p_ccb);

/* Functions provided by l2c_link.cc
 ***********************************
*/
extern bool l2c_link_hci_conn_req(const RawAddress& bd_addr);
extern bool l2c_link_hci_conn_comp(uint8_t status, uint16_t handle,
                                   const RawAddress& p_bda);
extern bool l2c_link_hci_disc_comp(uint16_t handle, uint8_t reason);
extern bool l2c_link_hci_qos_violation(uint16_t handle);
extern void l2c_link_timeout(tL2C_LCB* p_lcb);
extern void l2c_info_resp_timer_timeout(void* data);
extern void l2c_link_check_send_pkts(tL2C_LCB* p_lcb, tL2C_CCB* p_ccb,
                                     BT_HDR* p_buf);
extern void l2c_link_adjust_allocation(void);
extern void l2c_link_process_num_completed_pkts(uint8_t* p, uint8_t evt_len);
extern void l2c_link_process_num_completed_blocks(uint8_t controller_id,
                                                  uint8_t* p, uint16_t evt_len);
extern void l2c_link_processs_num_bufs(uint16_t num_lm_acl_bufs);
extern uint8_t l2c_link_pkts_rcvd(uint16_t* num_pkts, uint16_t* handles);
extern void l2c_link_role_changed(const RawAddress* bd_addr, uint8_t new_role,
                                  uint8_t hci_status);
extern void l2c_link_sec_comp(const RawAddress* p_bda, tBT_TRANSPORT trasnport,
                              void* p_ref_data, uint8_t status);
extern void l2c_link_sec_comp2(const RawAddress& p_bda, tBT_TRANSPORT trasnport,
                               void* p_ref_data, uint8_t status);
extern void l2c_link_segments_xmitted(BT_HDR* p_msg);
extern void l2c_pin_code_request(const RawAddress& bd_addr);
extern void l2c_link_adjust_chnl_allocation(void);

extern void l2c_link_processs_ble_num_bufs(uint16_t num_lm_acl_bufs);

#if (L2CAP_WAKE_PARKED_LINK == TRUE)
extern bool l2c_link_check_power_mode(tL2C_LCB* p_lcb);
#define L2C_LINK_CHECK_POWER_MODE(x) l2c_link_check_power_mode((x))
#else  // L2CAP_WAKE_PARKED_LINK
#define L2C_LINK_CHECK_POWER_MODE(x) (false)
#endif  // L2CAP_WAKE_PARKED_LINK

#if (L2CAP_CONFORMANCE_TESTING == TRUE)
/* Used only for conformance testing */
extern void l2cu_set_info_rsp_mask(uint32_t mask);
#endif

/* Functions provided by l2c_csm.cc
 ***********************************
*/
extern void l2c_csm_execute(tL2C_CCB* p_ccb, uint16_t event, void* p_data);

extern void l2c_enqueue_peer_data(tL2C_CCB* p_ccb, BT_HDR* p_buf);

/* Functions provided by l2c_fcr.cc
 ***********************************
*/
extern void l2c_fcr_cleanup(tL2C_CCB* p_ccb);
extern void l2c_fcr_proc_pdu(tL2C_CCB* p_ccb, BT_HDR* p_buf);
extern void l2c_fcr_proc_tout(tL2C_CCB* p_ccb);
extern void l2c_fcr_proc_ack_tout(tL2C_CCB* p_ccb);
extern void l2c_fcr_send_S_frame(tL2C_CCB* p_ccb, uint16_t function_code,
                                 uint16_t pf_bit);
extern BT_HDR* l2c_fcr_clone_buf(BT_HDR* p_buf, uint16_t new_offset,
                                 uint16_t no_of_bytes);
extern bool l2c_fcr_is_flow_controlled(tL2C_CCB* p_ccb);
extern BT_HDR* l2c_fcr_get_next_xmit_sdu_seg(tL2C_CCB* p_ccb,
                                             uint16_t max_packet_length);
extern void l2c_fcr_start_timer(tL2C_CCB* p_ccb);
extern void l2c_lcc_proc_pdu(tL2C_CCB* p_ccb, BT_HDR* p_buf);
extern BT_HDR* l2c_lcc_get_next_xmit_sdu_seg(tL2C_CCB* p_ccb,
                                             bool* last_piece_of_sdu);

/* Configuration negotiation */
extern uint8_t l2c_fcr_chk_chan_modes(tL2C_CCB* p_ccb);
extern bool l2c_fcr_adj_our_req_options(tL2C_CCB* p_ccb,
                                        tL2CAP_CFG_INFO* p_cfg);
extern void l2c_fcr_adj_our_rsp_options(tL2C_CCB* p_ccb,
                                        tL2CAP_CFG_INFO* p_peer_cfg);
extern bool l2c_fcr_renegotiate_chan(tL2C_CCB* p_ccb, tL2CAP_CFG_INFO* p_cfg);
extern uint8_t l2c_fcr_process_peer_cfg_req(tL2C_CCB* p_ccb,
                                            tL2CAP_CFG_INFO* p_cfg);
extern void l2c_fcr_adj_monitor_retran_timeout(tL2C_CCB* p_ccb);
extern void l2c_fcr_stop_timer(tL2C_CCB* p_ccb);

/* Functions provided by l2c_ble.cc
 ***********************************
*/
extern bool l2cble_create_conn(tL2C_LCB* p_lcb);
extern void l2cble_process_sig_cmd(tL2C_LCB* p_lcb, uint8_t* p,
                                   uint16_t pkt_len);
extern void l2cble_conn_comp(uint16_t handle, uint8_t role,
                             const RawAddress& bda, tBLE_ADDR_TYPE type,
                             uint16_t conn_interval, uint16_t conn_latency,
                             uint16_t conn_timeout);
extern void l2cble_notify_le_connection(const RawAddress& bda);
extern void l2c_ble_link_adjust_allocation(void);
extern void l2cble_process_conn_update_evt(uint16_t handle, uint8_t status,
                                           uint16_t interval, uint16_t latency,
                                           uint16_t timeout);

extern void l2cble_credit_based_conn_req(tL2C_CCB* p_ccb);
extern void l2cble_credit_based_conn_res(tL2C_CCB* p_ccb, uint16_t result);
extern void l2cble_send_peer_disc_req(tL2C_CCB* p_ccb);
extern void l2cble_send_flow_control_credit(tL2C_CCB* p_ccb,
                                            uint16_t credit_value);
extern tL2CAP_LE_RESULT_CODE l2ble_sec_access_req(const RawAddress& bd_addr,
                                                  uint16_t psm,
                                                  bool is_originator,
                                                  tL2CAP_SEC_CBACK* p_callback,
                                                  void* p_ref_data);

#if (BLE_LLT_INCLUDED == TRUE)
extern void l2cble_process_rc_param_request_evt(uint16_t handle,
                                                uint16_t int_min,
                                                uint16_t int_max,
                                                uint16_t latency,
                                                uint16_t timeout);
#endif

extern void l2cble_update_data_length(tL2C_LCB* p_lcb);
extern void l2cble_set_fixed_channel_tx_data_length(
    const RawAddress& remote_bda, uint16_t fix_cid, uint16_t tx_mtu);
extern void l2cble_process_data_length_change_event(uint16_t handle,
                                                    uint16_t tx_data_len,
                                                    uint16_t rx_data_len);

extern void l2cu_process_fixed_disc_cback(tL2C_LCB* p_lcb);

#endif