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