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      1 /******************************************************************************
      2  *
      3  *  Copyright (C) 1999-2012 Broadcom Corporation
      4  *
      5  *  Licensed under the Apache License, Version 2.0 (the "License");
      6  *  you may not use this file except in compliance with the License.
      7  *  You may obtain a copy of the License at:
      8  *
      9  *  http://www.apache.org/licenses/LICENSE-2.0
     10  *
     11  *  Unless required by applicable law or agreed to in writing, software
     12  *  distributed under the License is distributed on an "AS IS" BASIS,
     13  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14  *  See the License for the specific language governing permissions and
     15  *  limitations under the License.
     16  *
     17  ******************************************************************************/
     18 
     19 /******************************************************************************
     20  *
     21  *  this file contains the functions relating to link management. A "link"
     22  *  is a connection between this device and another device. Only ACL links
     23  *  are managed.
     24  *
     25  ******************************************************************************/
     26 
     27 #include <base/logging.h>
     28 #include <stdio.h>
     29 #include <stdlib.h>
     30 #include <string.h>
     31 
     32 #include "bt_common.h"
     33 #include "bt_types.h"
     34 #include "bt_utils.h"
     35 #include "btm_api.h"
     36 #include "btm_int.h"
     37 #include "btu.h"
     38 #include "device/include/controller.h"
     39 #include "hcimsgs.h"
     40 #include "l2c_api.h"
     41 #include "l2c_int.h"
     42 #include "l2cdefs.h"
     43 #include "osi/include/osi.h"
     44 
     45 static bool l2c_link_send_to_lower(tL2C_LCB* p_lcb, BT_HDR* p_buf,
     46                                    tL2C_TX_COMPLETE_CB_INFO* p_cbi);
     47 
     48 /*******************************************************************************
     49  *
     50  * Function         l2c_link_hci_conn_req
     51  *
     52  * Description      This function is called when an HCI Connection Request
     53  *                  event is received.
     54  *
     55  * Returns          true, if accept conn
     56  *
     57  ******************************************************************************/
     58 bool l2c_link_hci_conn_req(const RawAddress& bd_addr) {
     59   tL2C_LCB* p_lcb;
     60   tL2C_LCB* p_lcb_cur;
     61   int xx;
     62   bool no_links;
     63 
     64   /* See if we have a link control block for the remote device */
     65   p_lcb = l2cu_find_lcb_by_bd_addr(bd_addr, BT_TRANSPORT_BR_EDR);
     66 
     67   /* If we don't have one, create one and accept the connection. */
     68   if (!p_lcb) {
     69     p_lcb = l2cu_allocate_lcb(bd_addr, false, BT_TRANSPORT_BR_EDR);
     70     if (!p_lcb) {
     71       btsnd_hcic_reject_conn(bd_addr, HCI_ERR_HOST_REJECT_RESOURCES);
     72       L2CAP_TRACE_ERROR("L2CAP failed to allocate LCB");
     73       return false;
     74     }
     75 
     76     no_links = true;
     77 
     78     /* If we already have connection, accept as a master */
     79     for (xx = 0, p_lcb_cur = &l2cb.lcb_pool[0]; xx < MAX_L2CAP_LINKS;
     80          xx++, p_lcb_cur++) {
     81       if (p_lcb_cur == p_lcb) continue;
     82 
     83       if (p_lcb_cur->in_use) {
     84         no_links = false;
     85         p_lcb->link_role = HCI_ROLE_MASTER;
     86         break;
     87       }
     88     }
     89 
     90     if (no_links) {
     91       if (!btm_dev_support_switch(bd_addr))
     92         p_lcb->link_role = HCI_ROLE_SLAVE;
     93       else
     94         p_lcb->link_role = l2cu_get_conn_role(p_lcb);
     95     }
     96 
     97     /* Tell the other side we accept the connection */
     98     btsnd_hcic_accept_conn(bd_addr, p_lcb->link_role);
     99 
    100     p_lcb->link_state = LST_CONNECTING;
    101 
    102     /* Start a timer waiting for connect complete */
    103     alarm_set_on_mloop(p_lcb->l2c_lcb_timer, L2CAP_LINK_CONNECT_TIMEOUT_MS,
    104                        l2c_lcb_timer_timeout, p_lcb);
    105     return (true);
    106   }
    107 
    108   /* We already had a link control block to the guy. Check what state it is in
    109    */
    110   if ((p_lcb->link_state == LST_CONNECTING) ||
    111       (p_lcb->link_state == LST_CONNECT_HOLDING)) {
    112     /* Connection collision. Accept the connection anyways. */
    113 
    114     if (!btm_dev_support_switch(bd_addr))
    115       p_lcb->link_role = HCI_ROLE_SLAVE;
    116     else
    117       p_lcb->link_role = l2cu_get_conn_role(p_lcb);
    118 
    119     btsnd_hcic_accept_conn(bd_addr, p_lcb->link_role);
    120 
    121     p_lcb->link_state = LST_CONNECTING;
    122     return (true);
    123   } else if (p_lcb->link_state == LST_DISCONNECTING) {
    124     /* In disconnecting state, reject the connection. */
    125     btsnd_hcic_reject_conn(bd_addr, HCI_ERR_HOST_REJECT_DEVICE);
    126   } else {
    127     L2CAP_TRACE_ERROR(
    128         "L2CAP got conn_req while connected (state:%d). Reject it",
    129         p_lcb->link_state);
    130     /* Reject the connection with ACL Connection Already exist reason */
    131     btsnd_hcic_reject_conn(bd_addr, HCI_ERR_CONNECTION_EXISTS);
    132   }
    133   return (false);
    134 }
    135 
    136 /*******************************************************************************
    137  *
    138  * Function         l2c_link_hci_conn_comp
    139  *
    140  * Description      This function is called when an HCI Connection Complete
    141  *                  event is received.
    142  *
    143  * Returns          void
    144  *
    145  ******************************************************************************/
    146 bool l2c_link_hci_conn_comp(uint8_t status, uint16_t handle,
    147                             const RawAddress& p_bda) {
    148   tL2C_CONN_INFO ci;
    149   tL2C_LCB* p_lcb;
    150   tL2C_CCB* p_ccb;
    151   tBTM_SEC_DEV_REC* p_dev_info = NULL;
    152 
    153   btm_acl_update_busy_level(BTM_BLI_PAGE_DONE_EVT);
    154 
    155   /* Save the parameters */
    156   ci.status = status;
    157   ci.bd_addr = p_bda;
    158 
    159   /* See if we have a link control block for the remote device */
    160   p_lcb = l2cu_find_lcb_by_bd_addr(ci.bd_addr, BT_TRANSPORT_BR_EDR);
    161 
    162   /* If we don't have one, this is an error */
    163   if (!p_lcb) {
    164     L2CAP_TRACE_WARNING("L2CAP got conn_comp for unknown BD_ADDR");
    165     return (false);
    166   }
    167 
    168   if (p_lcb->link_state != LST_CONNECTING) {
    169     L2CAP_TRACE_ERROR("L2CAP got conn_comp in bad state: %d  status: 0x%d",
    170                       p_lcb->link_state, status);
    171 
    172     if (status != HCI_SUCCESS) l2c_link_hci_disc_comp(p_lcb->handle, status);
    173 
    174     return (false);
    175   }
    176 
    177   /* Save the handle */
    178   p_lcb->handle = handle;
    179 
    180   if (ci.status == HCI_SUCCESS) {
    181     /* Connected OK. Change state to connected */
    182     p_lcb->link_state = LST_CONNECTED;
    183 
    184     /* Get the peer information if the l2cap flow-control/rtrans is supported */
    185     l2cu_send_peer_info_req(p_lcb, L2CAP_EXTENDED_FEATURES_INFO_TYPE);
    186 
    187     /* Tell BTM Acl management about the link */
    188     p_dev_info = btm_find_dev(p_bda);
    189     if (p_dev_info != NULL)
    190       btm_acl_created(ci.bd_addr, p_dev_info->dev_class,
    191                       p_dev_info->sec_bd_name, handle, p_lcb->link_role,
    192                       BT_TRANSPORT_BR_EDR);
    193     else
    194       btm_acl_created(ci.bd_addr, NULL, NULL, handle, p_lcb->link_role,
    195                       BT_TRANSPORT_BR_EDR);
    196 
    197     BTM_SetLinkSuperTout(ci.bd_addr, btm_cb.btm_def_link_super_tout);
    198 
    199     /* If dedicated bonding do not process any further */
    200     if (p_lcb->is_bonding) {
    201       if (l2cu_start_post_bond_timer(handle)) return (true);
    202     }
    203 
    204     /* Update the timeouts in the hold queue */
    205     l2c_process_held_packets(false);
    206 
    207     alarm_cancel(p_lcb->l2c_lcb_timer);
    208 
    209     /* For all channels, send the event through their FSMs */
    210     for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;
    211          p_ccb = p_ccb->p_next_ccb) {
    212       l2c_csm_execute(p_ccb, L2CEVT_LP_CONNECT_CFM, &ci);
    213     }
    214 
    215     if (p_lcb->p_echo_rsp_cb) {
    216       l2cu_send_peer_echo_req(p_lcb, NULL, 0);
    217       alarm_set_on_mloop(p_lcb->l2c_lcb_timer, L2CAP_ECHO_RSP_TIMEOUT_MS,
    218                          l2c_lcb_timer_timeout, p_lcb);
    219     } else if (!p_lcb->ccb_queue.p_first_ccb) {
    220       period_ms_t timeout_ms = L2CAP_LINK_STARTUP_TOUT * 1000;
    221       alarm_set_on_mloop(p_lcb->l2c_lcb_timer, timeout_ms,
    222                          l2c_lcb_timer_timeout, p_lcb);
    223     }
    224   }
    225   /* Max number of acl connections.                          */
    226   /* If there's an lcb disconnecting set this one to holding */
    227   else if ((ci.status == HCI_ERR_MAX_NUM_OF_CONNECTIONS) &&
    228            l2cu_lcb_disconnecting()) {
    229     p_lcb->link_state = LST_CONNECT_HOLDING;
    230     p_lcb->handle = HCI_INVALID_HANDLE;
    231   } else {
    232     /* Just in case app decides to try again in the callback context */
    233     p_lcb->link_state = LST_DISCONNECTING;
    234 
    235     /* Connection failed. For all channels, send the event through */
    236     /* their FSMs. The CCBs should remove themselves from the LCB  */
    237     for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;) {
    238       tL2C_CCB* pn = p_ccb->p_next_ccb;
    239 
    240       l2c_csm_execute(p_ccb, L2CEVT_LP_CONNECT_CFM_NEG, &ci);
    241 
    242       p_ccb = pn;
    243     }
    244 
    245     p_lcb->disc_reason = status;
    246     /* Release the LCB */
    247     if (p_lcb->ccb_queue.p_first_ccb == NULL)
    248       l2cu_release_lcb(p_lcb);
    249     else /* there are any CCBs remaining */
    250     {
    251       if (ci.status == HCI_ERR_CONNECTION_EXISTS) {
    252         /* we are in collision situation, wait for connecttion request from
    253          * controller */
    254         p_lcb->link_state = LST_CONNECTING;
    255       } else {
    256         l2cu_create_conn(p_lcb, BT_TRANSPORT_BR_EDR);
    257       }
    258     }
    259   }
    260   return (true);
    261 }
    262 
    263 /*******************************************************************************
    264  *
    265  * Function         l2c_link_sec_comp
    266  *
    267  * Description      This function is called when required security procedures
    268  *                  are completed.
    269  *
    270  * Returns          void
    271  *
    272  ******************************************************************************/
    273 void l2c_link_sec_comp(const RawAddress* p_bda,
    274                        UNUSED_ATTR tBT_TRANSPORT transport, void* p_ref_data,
    275                        uint8_t status) {
    276   l2c_link_sec_comp2(*p_bda, transport, p_ref_data, status);
    277 }
    278 
    279 void l2c_link_sec_comp2(const RawAddress& p_bda,
    280                         UNUSED_ATTR tBT_TRANSPORT transport, void* p_ref_data,
    281                         uint8_t status) {
    282   tL2C_CONN_INFO ci;
    283   tL2C_LCB* p_lcb;
    284   tL2C_CCB* p_ccb;
    285   tL2C_CCB* p_next_ccb;
    286   uint8_t event;
    287 
    288   L2CAP_TRACE_DEBUG("l2c_link_sec_comp: %d, 0x%x", status, p_ref_data);
    289 
    290   if (status == BTM_SUCCESS_NO_SECURITY) status = BTM_SUCCESS;
    291 
    292   /* Save the parameters */
    293   ci.status = status;
    294   ci.bd_addr = p_bda;
    295 
    296   p_lcb = l2cu_find_lcb_by_bd_addr(p_bda, transport);
    297 
    298   /* If we don't have one, this is an error */
    299   if (!p_lcb) {
    300     L2CAP_TRACE_WARNING("L2CAP got sec_comp for unknown BD_ADDR");
    301     return;
    302   }
    303 
    304   /* Match p_ccb with p_ref_data returned by sec manager */
    305   for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; p_ccb = p_next_ccb) {
    306     p_next_ccb = p_ccb->p_next_ccb;
    307 
    308     if (p_ccb == p_ref_data) {
    309       switch (status) {
    310         case BTM_SUCCESS:
    311           event = L2CEVT_SEC_COMP;
    312           break;
    313 
    314         case BTM_DELAY_CHECK:
    315           /* start a timer - encryption change not received before L2CAP connect
    316            * req */
    317           alarm_set_on_mloop(p_ccb->l2c_ccb_timer,
    318                              L2CAP_DELAY_CHECK_SM4_TIMEOUT_MS,
    319                              l2c_ccb_timer_timeout, p_ccb);
    320           return;
    321 
    322         default:
    323           event = L2CEVT_SEC_COMP_NEG;
    324       }
    325       l2c_csm_execute(p_ccb, event, &ci);
    326       break;
    327     }
    328   }
    329 }
    330 
    331 /*******************************************************************************
    332  *
    333  * Function         l2c_link_hci_disc_comp
    334  *
    335  * Description      This function is called when an HCI Disconnect Complete
    336  *                  event is received.
    337  *
    338  * Returns          true if the link is known about, else false
    339  *
    340  ******************************************************************************/
    341 bool l2c_link_hci_disc_comp(uint16_t handle, uint8_t reason) {
    342   tL2C_LCB* p_lcb;
    343   tL2C_CCB* p_ccb;
    344   bool status = true;
    345   bool lcb_is_free = true;
    346   tBT_TRANSPORT transport = BT_TRANSPORT_BR_EDR;
    347 
    348   /* See if we have a link control block for the connection */
    349   p_lcb = l2cu_find_lcb_by_handle(handle);
    350 
    351   /* If we don't have one, maybe an SCO link. Send to MM */
    352   if (!p_lcb) {
    353     status = false;
    354   } else {
    355     /* There can be a case when we rejected PIN code authentication */
    356     /* otherwise save a new reason */
    357     if (btm_cb.acl_disc_reason != HCI_ERR_HOST_REJECT_SECURITY)
    358       btm_cb.acl_disc_reason = reason;
    359 
    360     p_lcb->disc_reason = btm_cb.acl_disc_reason;
    361 
    362     /* Just in case app decides to try again in the callback context */
    363     p_lcb->link_state = LST_DISCONNECTING;
    364 
    365     /* Check for BLE and handle that differently */
    366     if (p_lcb->transport == BT_TRANSPORT_LE)
    367       btm_ble_update_link_topology_mask(p_lcb->link_role, false);
    368     /* Link is disconnected. For all channels, send the event through */
    369     /* their FSMs. The CCBs should remove themselves from the LCB     */
    370     for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;) {
    371       tL2C_CCB* pn = p_ccb->p_next_ccb;
    372 
    373       /* Keep connect pending control block (if exists)
    374        * Possible Race condition when a reconnect occurs
    375        * on the channel during a disconnect of link. This
    376        * ccb will be automatically retried after link disconnect
    377        * arrives
    378        */
    379       if (p_ccb != p_lcb->p_pending_ccb) {
    380         l2c_csm_execute(p_ccb, L2CEVT_LP_DISCONNECT_IND, &reason);
    381       }
    382       p_ccb = pn;
    383     }
    384 
    385 #if (BTM_SCO_INCLUDED == TRUE)
    386     if (p_lcb->transport == BT_TRANSPORT_BR_EDR)
    387       /* Tell SCO management to drop any SCOs on this ACL */
    388       btm_sco_acl_removed(&p_lcb->remote_bd_addr);
    389 #endif
    390 
    391     /* If waiting for disconnect and reconnect is pending start the reconnect
    392        now
    393        race condition where layer above issued connect request on link that was
    394        disconnecting
    395      */
    396     if (p_lcb->ccb_queue.p_first_ccb != NULL || p_lcb->p_pending_ccb) {
    397       L2CAP_TRACE_DEBUG(
    398           "l2c_link_hci_disc_comp: Restarting pending ACL request");
    399       transport = p_lcb->transport;
    400       /* for LE link, always drop and re-open to ensure to get LE remote feature
    401        */
    402       if (p_lcb->transport == BT_TRANSPORT_LE) {
    403         l2cb.is_ble_connecting = false;
    404         btm_acl_removed(p_lcb->remote_bd_addr, p_lcb->transport);
    405         /* Release any held buffers */
    406         BT_HDR* p_buf;
    407         while (!list_is_empty(p_lcb->link_xmit_data_q)) {
    408           p_buf = static_cast<BT_HDR*>(list_front(p_lcb->link_xmit_data_q));
    409           list_remove(p_lcb->link_xmit_data_q, p_buf);
    410           osi_free(p_buf);
    411         }
    412       } else {
    413 #if (L2CAP_NUM_FIXED_CHNLS > 0)
    414         /* If we are going to re-use the LCB without dropping it, release all
    415         fixed channels
    416         here */
    417         int xx;
    418         for (xx = 0; xx < L2CAP_NUM_FIXED_CHNLS; xx++) {
    419           if (p_lcb->p_fixed_ccbs[xx] &&
    420               p_lcb->p_fixed_ccbs[xx] != p_lcb->p_pending_ccb) {
    421             (*l2cb.fixed_reg[xx].pL2CA_FixedConn_Cb)(
    422                 xx + L2CAP_FIRST_FIXED_CHNL, p_lcb->remote_bd_addr, false,
    423                 p_lcb->disc_reason, p_lcb->transport);
    424             if (p_lcb->p_fixed_ccbs[xx] == NULL) {
    425               L2CAP_TRACE_ERROR(
    426                   "%s: unexpected p_fixed_ccbs[%d] is NULL remote_bd_addr = %s "
    427                   "p_lcb = %p in_use = %d link_state = %d handle = %d "
    428                   "link_role = %d is_bonding = %d disc_reason = %d transport = "
    429                   "%d",
    430                   __func__, xx, p_lcb->remote_bd_addr.ToString().c_str(), p_lcb,
    431                   p_lcb->in_use, p_lcb->link_state, p_lcb->handle,
    432                   p_lcb->link_role, p_lcb->is_bonding, p_lcb->disc_reason,
    433                   p_lcb->transport);
    434             }
    435             CHECK(p_lcb->p_fixed_ccbs[xx] != NULL);
    436             l2cu_release_ccb(p_lcb->p_fixed_ccbs[xx]);
    437 
    438             p_lcb->p_fixed_ccbs[xx] = NULL;
    439           }
    440         }
    441 #endif
    442       }
    443       if (l2cu_create_conn(p_lcb, transport))
    444         lcb_is_free = false; /* still using this lcb */
    445     }
    446 
    447     p_lcb->p_pending_ccb = NULL;
    448 
    449     /* Release the LCB */
    450     if (lcb_is_free) l2cu_release_lcb(p_lcb);
    451   }
    452 
    453   /* Now that we have a free acl connection, see if any lcbs are pending */
    454   if (lcb_is_free &&
    455       ((p_lcb = l2cu_find_lcb_by_state(LST_CONNECT_HOLDING)) != NULL)) {
    456     /* we found one-- create a connection */
    457     l2cu_create_conn(p_lcb, BT_TRANSPORT_BR_EDR);
    458   }
    459 
    460   return status;
    461 }
    462 
    463 /*******************************************************************************
    464  *
    465  * Function         l2c_link_hci_qos_violation
    466  *
    467  * Description      This function is called when an HCI QOS Violation
    468  *                  event is received.
    469  *
    470  * Returns          true if the link is known about, else false
    471  *
    472  ******************************************************************************/
    473 bool l2c_link_hci_qos_violation(uint16_t handle) {
    474   tL2C_LCB* p_lcb;
    475   tL2C_CCB* p_ccb;
    476 
    477   /* See if we have a link control block for the connection */
    478   p_lcb = l2cu_find_lcb_by_handle(handle);
    479 
    480   /* If we don't have one, maybe an SCO link. */
    481   if (!p_lcb) return (false);
    482 
    483   /* For all channels, tell the upper layer about it */
    484   for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; p_ccb = p_ccb->p_next_ccb) {
    485     if (p_ccb->p_rcb->api.pL2CA_QoSViolationInd_Cb)
    486       l2c_csm_execute(p_ccb, L2CEVT_LP_QOS_VIOLATION_IND, NULL);
    487   }
    488 
    489   return (true);
    490 }
    491 
    492 /*******************************************************************************
    493  *
    494  * Function         l2c_link_timeout
    495  *
    496  * Description      This function is called when a link timer expires
    497  *
    498  * Returns          void
    499  *
    500  ******************************************************************************/
    501 void l2c_link_timeout(tL2C_LCB* p_lcb) {
    502   tL2C_CCB* p_ccb;
    503   tBTM_STATUS rc;
    504 
    505   L2CAP_TRACE_EVENT(
    506       "L2CAP - l2c_link_timeout() link state %d first CCB %p is_bonding:%d",
    507       p_lcb->link_state, p_lcb->ccb_queue.p_first_ccb, p_lcb->is_bonding);
    508 
    509   /* If link was connecting or disconnecting, clear all channels and drop the
    510    * LCB */
    511   if ((p_lcb->link_state == LST_CONNECTING_WAIT_SWITCH) ||
    512       (p_lcb->link_state == LST_CONNECTING) ||
    513       (p_lcb->link_state == LST_CONNECT_HOLDING) ||
    514       (p_lcb->link_state == LST_DISCONNECTING)) {
    515     p_lcb->p_pending_ccb = NULL;
    516 
    517     /* For all channels, send a disconnect indication event through */
    518     /* their FSMs. The CCBs should remove themselves from the LCB   */
    519     for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;) {
    520       tL2C_CCB* pn = p_ccb->p_next_ccb;
    521 
    522       l2c_csm_execute(p_ccb, L2CEVT_LP_DISCONNECT_IND, NULL);
    523 
    524       p_ccb = pn;
    525     }
    526     if (p_lcb->link_state == LST_CONNECTING && l2cb.is_ble_connecting == true) {
    527       L2CA_CancelBleConnectReq(l2cb.ble_connecting_bda);
    528     }
    529     /* Release the LCB */
    530     l2cu_release_lcb(p_lcb);
    531   }
    532 
    533   /* If link is connected, check for inactivity timeout */
    534   if (p_lcb->link_state == LST_CONNECTED) {
    535     /* Check for ping outstanding */
    536     if (p_lcb->p_echo_rsp_cb) {
    537       tL2CA_ECHO_RSP_CB* p_cb = p_lcb->p_echo_rsp_cb;
    538 
    539       /* Zero out the callback in case app immediately calls us again */
    540       p_lcb->p_echo_rsp_cb = NULL;
    541 
    542       (*p_cb)(L2CAP_PING_RESULT_NO_RESP);
    543 
    544       L2CAP_TRACE_WARNING("L2CAP - ping timeout");
    545 
    546       /* For all channels, send a disconnect indication event through */
    547       /* their FSMs. The CCBs should remove themselves from the LCB   */
    548       for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;) {
    549         tL2C_CCB* pn = p_ccb->p_next_ccb;
    550 
    551         l2c_csm_execute(p_ccb, L2CEVT_LP_DISCONNECT_IND, NULL);
    552 
    553         p_ccb = pn;
    554       }
    555     }
    556 
    557     /* If no channels in use, drop the link. */
    558     if (!p_lcb->ccb_queue.p_first_ccb) {
    559       period_ms_t timeout_ms;
    560       bool start_timeout = true;
    561 
    562       rc = btm_sec_disconnect(p_lcb->handle, HCI_ERR_PEER_USER);
    563 
    564       if (rc == BTM_CMD_STORED) {
    565         /* Security Manager will take care of disconnecting, state will be
    566          * updated at that time */
    567         start_timeout = false;
    568       } else if (rc == BTM_CMD_STARTED) {
    569         p_lcb->link_state = LST_DISCONNECTING;
    570         timeout_ms = L2CAP_LINK_DISCONNECT_TIMEOUT_MS;
    571       } else if (rc == BTM_SUCCESS) {
    572         l2cu_process_fixed_disc_cback(p_lcb);
    573         /* BTM SEC will make sure that link is release (probably after pairing
    574          * is done) */
    575         p_lcb->link_state = LST_DISCONNECTING;
    576         start_timeout = false;
    577       } else if (rc == BTM_BUSY) {
    578         /* BTM is still executing security process. Let lcb stay as connected */
    579         start_timeout = false;
    580       } else if (p_lcb->is_bonding) {
    581         btsnd_hcic_disconnect(p_lcb->handle, HCI_ERR_PEER_USER);
    582         l2cu_process_fixed_disc_cback(p_lcb);
    583         p_lcb->link_state = LST_DISCONNECTING;
    584         timeout_ms = L2CAP_LINK_DISCONNECT_TIMEOUT_MS;
    585       } else {
    586         /* probably no buffer to send disconnect */
    587         timeout_ms = BT_1SEC_TIMEOUT_MS;
    588       }
    589 
    590       if (start_timeout) {
    591         alarm_set_on_mloop(p_lcb->l2c_lcb_timer, timeout_ms,
    592                            l2c_lcb_timer_timeout, p_lcb);
    593       }
    594     } else {
    595       /* Check in case we were flow controlled */
    596       l2c_link_check_send_pkts(p_lcb, NULL, NULL);
    597     }
    598   }
    599 }
    600 
    601 /*******************************************************************************
    602  *
    603  * Function         l2c_info_resp_timer_timeout
    604  *
    605  * Description      This function is called when an info request times out
    606  *
    607  * Returns          void
    608  *
    609  ******************************************************************************/
    610 void l2c_info_resp_timer_timeout(void* data) {
    611   tL2C_LCB* p_lcb = (tL2C_LCB*)data;
    612   tL2C_CCB* p_ccb;
    613   tL2C_CONN_INFO ci;
    614 
    615   /* If we timed out waiting for info response, just continue using basic if
    616    * allowed */
    617   if (p_lcb->w4_info_rsp) {
    618     /* If waiting for security complete, restart the info response timer */
    619     for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;
    620          p_ccb = p_ccb->p_next_ccb) {
    621       if ((p_ccb->chnl_state == CST_ORIG_W4_SEC_COMP) ||
    622           (p_ccb->chnl_state == CST_TERM_W4_SEC_COMP)) {
    623         alarm_set_on_mloop(p_lcb->info_resp_timer,
    624                            L2CAP_WAIT_INFO_RSP_TIMEOUT_MS,
    625                            l2c_info_resp_timer_timeout, p_lcb);
    626         return;
    627       }
    628     }
    629 
    630     p_lcb->w4_info_rsp = false;
    631 
    632     /* If link is in process of being brought up */
    633     if ((p_lcb->link_state != LST_DISCONNECTED) &&
    634         (p_lcb->link_state != LST_DISCONNECTING)) {
    635       /* Notify active channels that peer info is finished */
    636       if (p_lcb->ccb_queue.p_first_ccb) {
    637         ci.status = HCI_SUCCESS;
    638         ci.bd_addr = p_lcb->remote_bd_addr;
    639 
    640         for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;
    641              p_ccb = p_ccb->p_next_ccb) {
    642           l2c_csm_execute(p_ccb, L2CEVT_L2CAP_INFO_RSP, &ci);
    643         }
    644       }
    645     }
    646   }
    647 }
    648 
    649 /*******************************************************************************
    650  *
    651  * Function         l2c_link_adjust_allocation
    652  *
    653  * Description      This function is called when a link is created or removed
    654  *                  to calculate the amount of packets each link may send to
    655  *                  the HCI without an ack coming back.
    656  *
    657  *                  Currently, this is a simple allocation, dividing the
    658  *                  number of Controller Packets by the number of links. In
    659  *                  the future, QOS configuration should be examined.
    660  *
    661  * Returns          void
    662  *
    663  ******************************************************************************/
    664 void l2c_link_adjust_allocation(void) {
    665   uint16_t qq, yy, qq_remainder;
    666   tL2C_LCB* p_lcb;
    667   uint16_t hi_quota, low_quota;
    668   uint16_t num_lowpri_links = 0;
    669   uint16_t num_hipri_links = 0;
    670   uint16_t controller_xmit_quota = l2cb.num_lm_acl_bufs;
    671   uint16_t high_pri_link_quota = L2CAP_HIGH_PRI_MIN_XMIT_QUOTA_A;
    672 
    673   /* If no links active, reset buffer quotas and controller buffers */
    674   if (l2cb.num_links_active == 0) {
    675     l2cb.controller_xmit_window = l2cb.num_lm_acl_bufs;
    676     l2cb.round_robin_quota = l2cb.round_robin_unacked = 0;
    677     return;
    678   }
    679 
    680   /* First, count the links */
    681   for (yy = 0, p_lcb = &l2cb.lcb_pool[0]; yy < MAX_L2CAP_LINKS; yy++, p_lcb++) {
    682     if (p_lcb->in_use) {
    683       if (p_lcb->acl_priority == L2CAP_PRIORITY_HIGH)
    684         num_hipri_links++;
    685       else
    686         num_lowpri_links++;
    687     }
    688   }
    689 
    690   /* now adjust high priority link quota */
    691   low_quota = num_lowpri_links ? 1 : 0;
    692   while ((num_hipri_links * high_pri_link_quota + low_quota) >
    693          controller_xmit_quota)
    694     high_pri_link_quota--;
    695 
    696   /* Work out the xmit quota and buffer quota high and low priorities */
    697   hi_quota = num_hipri_links * high_pri_link_quota;
    698   low_quota =
    699       (hi_quota < controller_xmit_quota) ? controller_xmit_quota - hi_quota : 1;
    700 
    701   /* Work out and save the HCI xmit quota for each low priority link */
    702 
    703   /* If each low priority link cannot have at least one buffer */
    704   if (num_lowpri_links > low_quota) {
    705     l2cb.round_robin_quota = low_quota;
    706     qq = qq_remainder = 1;
    707   }
    708   /* If each low priority link can have at least one buffer */
    709   else if (num_lowpri_links > 0) {
    710     l2cb.round_robin_quota = 0;
    711     l2cb.round_robin_unacked = 0;
    712     qq = low_quota / num_lowpri_links;
    713     qq_remainder = low_quota % num_lowpri_links;
    714   }
    715   /* If no low priority link */
    716   else {
    717     l2cb.round_robin_quota = 0;
    718     l2cb.round_robin_unacked = 0;
    719     qq = qq_remainder = 1;
    720   }
    721 
    722   L2CAP_TRACE_EVENT(
    723       "l2c_link_adjust_allocation  num_hipri: %u  num_lowpri: %u  low_quota: "
    724       "%u  round_robin_quota: %u  qq: %u",
    725       num_hipri_links, num_lowpri_links, low_quota, l2cb.round_robin_quota, qq);
    726 
    727   /* Now, assign the quotas to each link */
    728   for (yy = 0, p_lcb = &l2cb.lcb_pool[0]; yy < MAX_L2CAP_LINKS; yy++, p_lcb++) {
    729     if (p_lcb->in_use) {
    730       if (p_lcb->acl_priority == L2CAP_PRIORITY_HIGH) {
    731         p_lcb->link_xmit_quota = high_pri_link_quota;
    732       } else {
    733         /* Safety check in case we switched to round-robin with something
    734          * outstanding */
    735         /* if sent_not_acked is added into round_robin_unacked then don't add it
    736          * again */
    737         /* l2cap keeps updating sent_not_acked for exiting from round robin */
    738         if ((p_lcb->link_xmit_quota > 0) && (qq == 0))
    739           l2cb.round_robin_unacked += p_lcb->sent_not_acked;
    740 
    741         p_lcb->link_xmit_quota = qq;
    742         if (qq_remainder > 0) {
    743           p_lcb->link_xmit_quota++;
    744           qq_remainder--;
    745         }
    746       }
    747 
    748       L2CAP_TRACE_EVENT(
    749           "l2c_link_adjust_allocation LCB %d   Priority: %d  XmitQuota: %d", yy,
    750           p_lcb->acl_priority, p_lcb->link_xmit_quota);
    751 
    752       L2CAP_TRACE_EVENT("        SentNotAcked: %d  RRUnacked: %d",
    753                         p_lcb->sent_not_acked, l2cb.round_robin_unacked);
    754 
    755       /* There is a special case where we have readjusted the link quotas and */
    756       /* this link may have sent anything but some other link sent packets so */
    757       /* so we may need a timer to kick off this link's transmissions. */
    758       if ((p_lcb->link_state == LST_CONNECTED) &&
    759           (!list_is_empty(p_lcb->link_xmit_data_q)) &&
    760           (p_lcb->sent_not_acked < p_lcb->link_xmit_quota)) {
    761         alarm_set_on_mloop(p_lcb->l2c_lcb_timer,
    762                            L2CAP_LINK_FLOW_CONTROL_TIMEOUT_MS,
    763                            l2c_lcb_timer_timeout, p_lcb);
    764       }
    765     }
    766   }
    767 }
    768 
    769 /*******************************************************************************
    770  *
    771  * Function         l2c_link_adjust_chnl_allocation
    772  *
    773  * Description      This function is called to calculate the amount of packets
    774  *                  each non-F&EC channel may have outstanding.
    775  *
    776  *                  Currently, this is a simple allocation, dividing the number
    777  *                  of packets allocated to the link by the number of channels.
    778  *                  In the future, QOS configuration should be examined.
    779  *
    780  * Returns          void
    781  *
    782  ******************************************************************************/
    783 void l2c_link_adjust_chnl_allocation(void) {
    784   uint8_t xx;
    785 
    786   L2CAP_TRACE_DEBUG("%s", __func__);
    787 
    788   /* assign buffer quota to each channel based on its data rate requirement */
    789   for (xx = 0; xx < MAX_L2CAP_CHANNELS; xx++) {
    790     tL2C_CCB* p_ccb = l2cb.ccb_pool + xx;
    791 
    792     if (!p_ccb->in_use) continue;
    793 
    794     tL2CAP_CHNL_DATA_RATE data_rate = p_ccb->tx_data_rate + p_ccb->rx_data_rate;
    795     p_ccb->buff_quota = L2CAP_CBB_DEFAULT_DATA_RATE_BUFF_QUOTA * data_rate;
    796     L2CAP_TRACE_EVENT(
    797         "CID:0x%04x FCR Mode:%u Priority:%u TxDataRate:%u RxDataRate:%u "
    798         "Quota:%u",
    799         p_ccb->local_cid, p_ccb->peer_cfg.fcr.mode, p_ccb->ccb_priority,
    800         p_ccb->tx_data_rate, p_ccb->rx_data_rate, p_ccb->buff_quota);
    801 
    802     /* quota may be change so check congestion */
    803     l2cu_check_channel_congestion(p_ccb);
    804   }
    805 }
    806 
    807 /*******************************************************************************
    808  *
    809  * Function         l2c_link_processs_num_bufs
    810  *
    811  * Description      This function is called when a "controller buffer size"
    812  *                  event is first received from the controller. It updates
    813  *                  the L2CAP values.
    814  *
    815  * Returns          void
    816  *
    817  ******************************************************************************/
    818 void l2c_link_processs_num_bufs(uint16_t num_lm_acl_bufs) {
    819   l2cb.num_lm_acl_bufs = l2cb.controller_xmit_window = num_lm_acl_bufs;
    820 }
    821 
    822 /*******************************************************************************
    823  *
    824  * Function         l2c_link_pkts_rcvd
    825  *
    826  * Description      This function is called from the HCI transport when it is
    827  *                  time to send a "Host ready for packets" command. This is
    828  *                  only when host to controller flow control is used. It fills
    829  *                  in the arrays of numbers of packets and handles.
    830  *
    831  * Returns          count of number of entries filled in
    832  *
    833  ******************************************************************************/
    834 uint8_t l2c_link_pkts_rcvd(UNUSED_ATTR uint16_t* num_pkts,
    835                            UNUSED_ATTR uint16_t* handles) {
    836   uint8_t num_found = 0;
    837 
    838   return (num_found);
    839 }
    840 
    841 /*******************************************************************************
    842  *
    843  * Function         l2c_link_role_changed
    844  *
    845  * Description      This function is called whan a link's master/slave role
    846  *                  change event is received. It simply updates the link control
    847  *                  block.
    848  *
    849  * Returns          void
    850  *
    851  ******************************************************************************/
    852 void l2c_link_role_changed(const RawAddress* bd_addr, uint8_t new_role,
    853                            uint8_t hci_status) {
    854   tL2C_LCB* p_lcb;
    855   int xx;
    856 
    857   /* Make sure not called from HCI Command Status (bd_addr and new_role are
    858    * invalid) */
    859   if (bd_addr) {
    860     /* If here came form hci role change event */
    861     p_lcb = l2cu_find_lcb_by_bd_addr(*bd_addr, BT_TRANSPORT_BR_EDR);
    862     if (p_lcb) {
    863       p_lcb->link_role = new_role;
    864 
    865       /* Reset high priority link if needed */
    866       if (hci_status == HCI_SUCCESS)
    867         l2cu_set_acl_priority(*bd_addr, p_lcb->acl_priority, true);
    868     }
    869   }
    870 
    871   /* Check if any LCB was waiting for switch to be completed */
    872   for (xx = 0, p_lcb = &l2cb.lcb_pool[0]; xx < MAX_L2CAP_LINKS; xx++, p_lcb++) {
    873     if ((p_lcb->in_use) && (p_lcb->link_state == LST_CONNECTING_WAIT_SWITCH)) {
    874       l2cu_create_conn_after_switch(p_lcb);
    875     }
    876   }
    877 }
    878 
    879 /*******************************************************************************
    880  *
    881  * Function         l2c_pin_code_request
    882  *
    883  * Description      This function is called whan a pin-code request is received
    884  *                  on a connection. If there are no channels active yet on the
    885  *                  link, it extends the link first connection timer.  Make sure
    886  *                  that inactivity timer is not extended if PIN code happens
    887  *                  to be after last ccb released.
    888  *
    889  * Returns          void
    890  *
    891  ******************************************************************************/
    892 void l2c_pin_code_request(const RawAddress& bd_addr) {
    893   tL2C_LCB* p_lcb = l2cu_find_lcb_by_bd_addr(bd_addr, BT_TRANSPORT_BR_EDR);
    894 
    895   if ((p_lcb) && (!p_lcb->ccb_queue.p_first_ccb)) {
    896     alarm_set_on_mloop(p_lcb->l2c_lcb_timer, L2CAP_LINK_CONNECT_EXT_TIMEOUT_MS,
    897                        l2c_lcb_timer_timeout, p_lcb);
    898   }
    899 }
    900 
    901 #if (L2CAP_WAKE_PARKED_LINK == TRUE)
    902 /*******************************************************************************
    903  *
    904  * Function         l2c_link_check_power_mode
    905  *
    906  * Description      This function is called to check power mode.
    907  *
    908  * Returns          true if link is going to be active from park
    909  *                  false if nothing to send or not in park mode
    910  *
    911  ******************************************************************************/
    912 bool l2c_link_check_power_mode(tL2C_LCB* p_lcb) {
    913   tBTM_PM_MODE mode;
    914   tL2C_CCB* p_ccb;
    915   bool need_to_active = false;
    916 
    917   /*
    918    * We only switch park to active only if we have unsent packets
    919    */
    920   if (list_is_empty(p_lcb->link_xmit_data_q)) {
    921     for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;
    922          p_ccb = p_ccb->p_next_ccb) {
    923       if (!fixed_queue_is_empty(p_ccb->xmit_hold_q)) {
    924         need_to_active = true;
    925         break;
    926       }
    927     }
    928   } else
    929     need_to_active = true;
    930 
    931   /* if we have packets to send */
    932   if (need_to_active) {
    933     /* check power mode */
    934     if (BTM_ReadPowerMode(p_lcb->remote_bd_addr, &mode) == BTM_SUCCESS) {
    935       if (mode == BTM_PM_STS_PENDING) {
    936         L2CAP_TRACE_DEBUG("LCB(0x%x) is in PM pending state", p_lcb->handle);
    937 
    938         return true;
    939       }
    940     }
    941   }
    942   return false;
    943 }
    944 #endif /* L2CAP_WAKE_PARKED_LINK == TRUE) */
    945 
    946 /*******************************************************************************
    947  *
    948  * Function         l2c_link_check_send_pkts
    949  *
    950  * Description      This function is called to check if it can send packets
    951  *                  to the Host Controller. It may be passed the address of
    952  *                  a packet to send.
    953  *
    954  * Returns          void
    955  *
    956  ******************************************************************************/
    957 void l2c_link_check_send_pkts(tL2C_LCB* p_lcb, tL2C_CCB* p_ccb, BT_HDR* p_buf) {
    958   int xx;
    959   bool single_write = false;
    960 
    961   /* Save the channel ID for faster counting */
    962   if (p_buf) {
    963     if (p_ccb != NULL) {
    964       p_buf->event = p_ccb->local_cid;
    965       single_write = true;
    966     } else
    967       p_buf->event = 0;
    968 
    969     p_buf->layer_specific = 0;
    970     list_append(p_lcb->link_xmit_data_q, p_buf);
    971 
    972     if (p_lcb->link_xmit_quota == 0) {
    973       if (p_lcb->transport == BT_TRANSPORT_LE)
    974         l2cb.ble_check_round_robin = true;
    975       else
    976         l2cb.check_round_robin = true;
    977     }
    978   }
    979 
    980   /* If this is called from uncongested callback context break recursive
    981   *calling.
    982   ** This LCB will be served when receiving number of completed packet event.
    983   */
    984   if (l2cb.is_cong_cback_context) return;
    985 
    986   /* If we are in a scenario where there are not enough buffers for each link to
    987   ** have at least 1, then do a round-robin for all the LCBs
    988   */
    989   if ((p_lcb == NULL) || (p_lcb->link_xmit_quota == 0)) {
    990     if (p_lcb == NULL)
    991       p_lcb = l2cb.lcb_pool;
    992     else if (!single_write)
    993       p_lcb++;
    994 
    995     /* Loop through, starting at the next */
    996     for (xx = 0; xx < MAX_L2CAP_LINKS; xx++, p_lcb++) {
    997       /* Check for wraparound */
    998       if (p_lcb == &l2cb.lcb_pool[MAX_L2CAP_LINKS]) p_lcb = &l2cb.lcb_pool[0];
    999 
   1000       /* If controller window is full, nothing to do */
   1001       if (((l2cb.controller_xmit_window == 0 ||
   1002             (l2cb.round_robin_unacked >= l2cb.round_robin_quota)) &&
   1003            (p_lcb->transport == BT_TRANSPORT_BR_EDR)) ||
   1004           (p_lcb->transport == BT_TRANSPORT_LE &&
   1005            (l2cb.ble_round_robin_unacked >= l2cb.ble_round_robin_quota ||
   1006             l2cb.controller_le_xmit_window == 0)))
   1007         continue;
   1008 
   1009       if ((!p_lcb->in_use) || (p_lcb->partial_segment_being_sent) ||
   1010           (p_lcb->link_state != LST_CONNECTED) ||
   1011           (p_lcb->link_xmit_quota != 0) || (L2C_LINK_CHECK_POWER_MODE(p_lcb)))
   1012         continue;
   1013 
   1014       /* See if we can send anything from the Link Queue */
   1015       if (!list_is_empty(p_lcb->link_xmit_data_q)) {
   1016         p_buf = (BT_HDR*)list_front(p_lcb->link_xmit_data_q);
   1017         list_remove(p_lcb->link_xmit_data_q, p_buf);
   1018         l2c_link_send_to_lower(p_lcb, p_buf, NULL);
   1019       } else if (single_write) {
   1020         /* If only doing one write, break out */
   1021         break;
   1022       }
   1023       /* If nothing on the link queue, check the channel queue */
   1024       else {
   1025         tL2C_TX_COMPLETE_CB_INFO cbi;
   1026         p_buf = l2cu_get_next_buffer_to_send(p_lcb, &cbi);
   1027         if (p_buf != NULL) {
   1028           l2c_link_send_to_lower(p_lcb, p_buf, &cbi);
   1029         }
   1030       }
   1031     }
   1032 
   1033     /* If we finished without using up our quota, no need for a safety check */
   1034     if ((l2cb.controller_xmit_window > 0) &&
   1035         (l2cb.round_robin_unacked < l2cb.round_robin_quota) &&
   1036         (p_lcb->transport == BT_TRANSPORT_BR_EDR))
   1037       l2cb.check_round_robin = false;
   1038 
   1039     if ((l2cb.controller_le_xmit_window > 0) &&
   1040         (l2cb.ble_round_robin_unacked < l2cb.ble_round_robin_quota) &&
   1041         (p_lcb->transport == BT_TRANSPORT_LE))
   1042       l2cb.ble_check_round_robin = false;
   1043   } else /* if this is not round-robin service */
   1044   {
   1045     /* If a partial segment is being sent, can't send anything else */
   1046     if ((p_lcb->partial_segment_being_sent) ||
   1047         (p_lcb->link_state != LST_CONNECTED) ||
   1048         (L2C_LINK_CHECK_POWER_MODE(p_lcb)))
   1049       return;
   1050 
   1051     /* See if we can send anything from the link queue */
   1052     while (((l2cb.controller_xmit_window != 0 &&
   1053              (p_lcb->transport == BT_TRANSPORT_BR_EDR)) ||
   1054             (l2cb.controller_le_xmit_window != 0 &&
   1055              (p_lcb->transport == BT_TRANSPORT_LE))) &&
   1056            (p_lcb->sent_not_acked < p_lcb->link_xmit_quota)) {
   1057       if (list_is_empty(p_lcb->link_xmit_data_q)) break;
   1058 
   1059       p_buf = (BT_HDR*)list_front(p_lcb->link_xmit_data_q);
   1060       list_remove(p_lcb->link_xmit_data_q, p_buf);
   1061       if (!l2c_link_send_to_lower(p_lcb, p_buf, NULL)) break;
   1062     }
   1063 
   1064     if (!single_write) {
   1065       /* See if we can send anything for any channel */
   1066       while (((l2cb.controller_xmit_window != 0 &&
   1067                (p_lcb->transport == BT_TRANSPORT_BR_EDR)) ||
   1068               (l2cb.controller_le_xmit_window != 0 &&
   1069                (p_lcb->transport == BT_TRANSPORT_LE))) &&
   1070              (p_lcb->sent_not_acked < p_lcb->link_xmit_quota)) {
   1071         tL2C_TX_COMPLETE_CB_INFO cbi;
   1072         p_buf = l2cu_get_next_buffer_to_send(p_lcb, &cbi);
   1073         if (p_buf == NULL) break;
   1074 
   1075         if (!l2c_link_send_to_lower(p_lcb, p_buf, &cbi)) break;
   1076       }
   1077     }
   1078 
   1079     /* There is a special case where we have readjusted the link quotas and  */
   1080     /* this link may have sent anything but some other link sent packets so  */
   1081     /* so we may need a timer to kick off this link's transmissions.         */
   1082     if ((!list_is_empty(p_lcb->link_xmit_data_q)) &&
   1083         (p_lcb->sent_not_acked < p_lcb->link_xmit_quota)) {
   1084       alarm_set_on_mloop(p_lcb->l2c_lcb_timer,
   1085                          L2CAP_LINK_FLOW_CONTROL_TIMEOUT_MS,
   1086                          l2c_lcb_timer_timeout, p_lcb);
   1087     }
   1088   }
   1089 }
   1090 
   1091 /*******************************************************************************
   1092  *
   1093  * Function         l2c_link_send_to_lower
   1094  *
   1095  * Description      This function queues the buffer for HCI transmission
   1096  *
   1097  * Returns          true for success, false for fail
   1098  *
   1099  ******************************************************************************/
   1100 static bool l2c_link_send_to_lower(tL2C_LCB* p_lcb, BT_HDR* p_buf,
   1101                                    tL2C_TX_COMPLETE_CB_INFO* p_cbi) {
   1102   uint16_t num_segs;
   1103   uint16_t xmit_window, acl_data_size;
   1104   const controller_t* controller = controller_get_interface();
   1105 
   1106   if ((p_buf->len <= controller->get_acl_packet_size_classic() &&
   1107        (p_lcb->transport == BT_TRANSPORT_BR_EDR)) ||
   1108       ((p_lcb->transport == BT_TRANSPORT_LE) &&
   1109        (p_buf->len <= controller->get_acl_packet_size_ble()))) {
   1110     if (p_lcb->link_xmit_quota == 0) {
   1111       if (p_lcb->transport == BT_TRANSPORT_LE)
   1112         l2cb.ble_round_robin_unacked++;
   1113       else
   1114         l2cb.round_robin_unacked++;
   1115     }
   1116     p_lcb->sent_not_acked++;
   1117     p_buf->layer_specific = 0;
   1118 
   1119     if (p_lcb->transport == BT_TRANSPORT_LE) {
   1120       l2cb.controller_le_xmit_window--;
   1121       bte_main_hci_send(
   1122           p_buf, (uint16_t)(BT_EVT_TO_LM_HCI_ACL | LOCAL_BLE_CONTROLLER_ID));
   1123     } else {
   1124       l2cb.controller_xmit_window--;
   1125       bte_main_hci_send(p_buf, BT_EVT_TO_LM_HCI_ACL);
   1126     }
   1127   } else {
   1128     if (p_lcb->transport == BT_TRANSPORT_LE) {
   1129       acl_data_size = controller->get_acl_data_size_ble();
   1130       xmit_window = l2cb.controller_le_xmit_window;
   1131 
   1132     } else {
   1133       acl_data_size = controller->get_acl_data_size_classic();
   1134       xmit_window = l2cb.controller_xmit_window;
   1135     }
   1136     num_segs = (p_buf->len - HCI_DATA_PREAMBLE_SIZE + acl_data_size - 1) /
   1137                acl_data_size;
   1138 
   1139     /* If doing round-robin, then only 1 segment each time */
   1140     if (p_lcb->link_xmit_quota == 0) {
   1141       num_segs = 1;
   1142       p_lcb->partial_segment_being_sent = true;
   1143     } else {
   1144       /* Multi-segment packet. Make sure it can fit */
   1145       if (num_segs > xmit_window) {
   1146         num_segs = xmit_window;
   1147         p_lcb->partial_segment_being_sent = true;
   1148       }
   1149 
   1150       if (num_segs > (p_lcb->link_xmit_quota - p_lcb->sent_not_acked)) {
   1151         num_segs = (p_lcb->link_xmit_quota - p_lcb->sent_not_acked);
   1152         p_lcb->partial_segment_being_sent = true;
   1153       }
   1154     }
   1155 
   1156     p_buf->layer_specific = num_segs;
   1157     if (p_lcb->transport == BT_TRANSPORT_LE) {
   1158       l2cb.controller_le_xmit_window -= num_segs;
   1159       if (p_lcb->link_xmit_quota == 0) l2cb.ble_round_robin_unacked += num_segs;
   1160     } else {
   1161       l2cb.controller_xmit_window -= num_segs;
   1162 
   1163       if (p_lcb->link_xmit_quota == 0) l2cb.round_robin_unacked += num_segs;
   1164     }
   1165 
   1166     p_lcb->sent_not_acked += num_segs;
   1167     if (p_lcb->transport == BT_TRANSPORT_LE) {
   1168       bte_main_hci_send(
   1169           p_buf, (uint16_t)(BT_EVT_TO_LM_HCI_ACL | LOCAL_BLE_CONTROLLER_ID));
   1170     } else {
   1171       bte_main_hci_send(p_buf, BT_EVT_TO_LM_HCI_ACL);
   1172     }
   1173   }
   1174 
   1175 #if (L2CAP_HCI_FLOW_CONTROL_DEBUG == TRUE)
   1176   if (p_lcb->transport == BT_TRANSPORT_LE) {
   1177     L2CAP_TRACE_DEBUG(
   1178         "TotalWin=%d,Hndl=0x%x,Quota=%d,Unack=%d,RRQuota=%d,RRUnack=%d",
   1179         l2cb.controller_le_xmit_window, p_lcb->handle, p_lcb->link_xmit_quota,
   1180         p_lcb->sent_not_acked, l2cb.ble_round_robin_quota,
   1181         l2cb.ble_round_robin_unacked);
   1182   } else {
   1183     L2CAP_TRACE_DEBUG(
   1184         "TotalWin=%d,Hndl=0x%x,Quota=%d,Unack=%d,RRQuota=%d,RRUnack=%d",
   1185         l2cb.controller_xmit_window, p_lcb->handle, p_lcb->link_xmit_quota,
   1186         p_lcb->sent_not_acked, l2cb.round_robin_quota,
   1187         l2cb.round_robin_unacked);
   1188   }
   1189 #endif
   1190 
   1191   if (p_cbi) l2cu_tx_complete(p_cbi);
   1192 
   1193   return true;
   1194 }
   1195 
   1196 /*******************************************************************************
   1197  *
   1198  * Function         l2c_link_process_num_completed_pkts
   1199  *
   1200  * Description      This function is called when a "number-of-completed-packets"
   1201  *                  event is received from the controller. It updates all the
   1202  *                  LCB transmit counts.
   1203  *
   1204  * Returns          void
   1205  *
   1206  ******************************************************************************/
   1207 void l2c_link_process_num_completed_pkts(uint8_t* p) {
   1208   uint8_t num_handles, xx;
   1209   uint16_t handle;
   1210   uint16_t num_sent;
   1211   tL2C_LCB* p_lcb;
   1212 
   1213   STREAM_TO_UINT8(num_handles, p);
   1214 
   1215   for (xx = 0; xx < num_handles; xx++) {
   1216     STREAM_TO_UINT16(handle, p);
   1217     STREAM_TO_UINT16(num_sent, p);
   1218 
   1219     p_lcb = l2cu_find_lcb_by_handle(handle);
   1220 
   1221     /* Callback for number of completed packet event    */
   1222     /* Originally designed for [3DSG]                   */
   1223     if ((p_lcb != NULL) && (p_lcb->p_nocp_cb)) {
   1224       L2CAP_TRACE_DEBUG("L2CAP - calling NoCP callback");
   1225       (*p_lcb->p_nocp_cb)(p_lcb->remote_bd_addr);
   1226     }
   1227 
   1228     if (p_lcb) {
   1229       if (p_lcb && (p_lcb->transport == BT_TRANSPORT_LE))
   1230         l2cb.controller_le_xmit_window += num_sent;
   1231       else {
   1232         /* Maintain the total window to the controller */
   1233         l2cb.controller_xmit_window += num_sent;
   1234       }
   1235       /* If doing round-robin, adjust communal counts */
   1236       if (p_lcb->link_xmit_quota == 0) {
   1237         if (p_lcb->transport == BT_TRANSPORT_LE) {
   1238           /* Don't go negative */
   1239           if (l2cb.ble_round_robin_unacked > num_sent)
   1240             l2cb.ble_round_robin_unacked -= num_sent;
   1241           else
   1242             l2cb.ble_round_robin_unacked = 0;
   1243         } else {
   1244           /* Don't go negative */
   1245           if (l2cb.round_robin_unacked > num_sent)
   1246             l2cb.round_robin_unacked -= num_sent;
   1247           else
   1248             l2cb.round_robin_unacked = 0;
   1249         }
   1250       }
   1251 
   1252       /* Don't go negative */
   1253       if (p_lcb->sent_not_acked > num_sent)
   1254         p_lcb->sent_not_acked -= num_sent;
   1255       else
   1256         p_lcb->sent_not_acked = 0;
   1257 
   1258       l2c_link_check_send_pkts(p_lcb, NULL, NULL);
   1259 
   1260       /* If we were doing round-robin for low priority links, check 'em */
   1261       if ((p_lcb->acl_priority == L2CAP_PRIORITY_HIGH) &&
   1262           (l2cb.check_round_robin) &&
   1263           (l2cb.round_robin_unacked < l2cb.round_robin_quota)) {
   1264         l2c_link_check_send_pkts(NULL, NULL, NULL);
   1265       }
   1266       if ((p_lcb->transport == BT_TRANSPORT_LE) &&
   1267           (p_lcb->acl_priority == L2CAP_PRIORITY_HIGH) &&
   1268           ((l2cb.ble_check_round_robin) &&
   1269            (l2cb.ble_round_robin_unacked < l2cb.ble_round_robin_quota))) {
   1270         l2c_link_check_send_pkts(NULL, NULL, NULL);
   1271       }
   1272     }
   1273 
   1274 #if (L2CAP_HCI_FLOW_CONTROL_DEBUG == TRUE)
   1275     if (p_lcb) {
   1276       if (p_lcb->transport == BT_TRANSPORT_LE) {
   1277         L2CAP_TRACE_DEBUG(
   1278             "TotalWin=%d,LinkUnack(0x%x)=%d,RRCheck=%d,RRUnack=%d",
   1279             l2cb.controller_le_xmit_window, p_lcb->handle,
   1280             p_lcb->sent_not_acked, l2cb.ble_check_round_robin,
   1281             l2cb.ble_round_robin_unacked);
   1282       } else {
   1283         L2CAP_TRACE_DEBUG(
   1284             "TotalWin=%d,LinkUnack(0x%x)=%d,RRCheck=%d,RRUnack=%d",
   1285             l2cb.controller_xmit_window, p_lcb->handle, p_lcb->sent_not_acked,
   1286             l2cb.check_round_robin, l2cb.round_robin_unacked);
   1287       }
   1288     } else {
   1289       L2CAP_TRACE_DEBUG(
   1290           "TotalWin=%d  LE_Win: %d, Handle=0x%x, RRCheck=%d, RRUnack=%d",
   1291           l2cb.controller_xmit_window, l2cb.controller_le_xmit_window, handle,
   1292           l2cb.ble_check_round_robin, l2cb.ble_round_robin_unacked);
   1293     }
   1294 #endif
   1295   }
   1296 }
   1297 
   1298 /*******************************************************************************
   1299  *
   1300  * Function         l2c_link_segments_xmitted
   1301  *
   1302  * Description      This function is called from the HCI Interface when an ACL
   1303  *                  data packet segment is transmitted.
   1304  *
   1305  * Returns          void
   1306  *
   1307  ******************************************************************************/
   1308 void l2c_link_segments_xmitted(BT_HDR* p_msg) {
   1309   uint8_t* p = (uint8_t*)(p_msg + 1) + p_msg->offset;
   1310   uint16_t handle;
   1311   tL2C_LCB* p_lcb;
   1312 
   1313   /* Extract the handle */
   1314   STREAM_TO_UINT16(handle, p);
   1315   handle = HCID_GET_HANDLE(handle);
   1316 
   1317   /* Find the LCB based on the handle */
   1318   p_lcb = l2cu_find_lcb_by_handle(handle);
   1319   if (p_lcb == NULL) {
   1320     L2CAP_TRACE_WARNING("L2CAP - rcvd segment complete, unknown handle: %d",
   1321                         handle);
   1322     osi_free(p_msg);
   1323     return;
   1324   }
   1325 
   1326   if (p_lcb->link_state == LST_CONNECTED) {
   1327     /* Enqueue the buffer to the head of the transmit queue, and see */
   1328     /* if we can transmit anything more.                             */
   1329     list_prepend(p_lcb->link_xmit_data_q, p_msg);
   1330 
   1331     p_lcb->partial_segment_being_sent = false;
   1332 
   1333     l2c_link_check_send_pkts(p_lcb, NULL, NULL);
   1334   } else
   1335     osi_free(p_msg);
   1336 }
   1337