1 /******************************************************************************
2  *
3  *  Copyright 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 "log/log.h"
44 #include "osi/include/osi.h"
45 
46 static bool l2c_link_send_to_lower(tL2C_LCB* p_lcb, BT_HDR* p_buf,
47                                    tL2C_TX_COMPLETE_CB_INFO* p_cbi);
48 
49 /*******************************************************************************
50  *
51  * Function         l2c_link_hci_conn_req
52  *
53  * Description      This function is called when an HCI Connection Request
54  *                  event is received.
55  *
56  * Returns          true, if accept conn
57  *
58  ******************************************************************************/
l2c_link_hci_conn_req(const RawAddress & bd_addr)59 bool l2c_link_hci_conn_req(const RawAddress& bd_addr) {
60   tL2C_LCB* p_lcb;
61   tL2C_LCB* p_lcb_cur;
62   int xx;
63   bool no_links;
64 
65   /* See if we have a link control block for the remote device */
66   p_lcb = l2cu_find_lcb_by_bd_addr(bd_addr, BT_TRANSPORT_BR_EDR);
67 
68   /* If we don't have one, create one and accept the connection. */
69   if (!p_lcb) {
70     p_lcb = l2cu_allocate_lcb(bd_addr, false, BT_TRANSPORT_BR_EDR);
71     if (!p_lcb) {
72       btsnd_hcic_reject_conn(bd_addr, HCI_ERR_HOST_REJECT_RESOURCES);
73       L2CAP_TRACE_ERROR("L2CAP failed to allocate LCB");
74       return false;
75     }
76 
77     no_links = true;
78 
79     /* If we already have connection, accept as a master */
80     for (xx = 0, p_lcb_cur = &l2cb.lcb_pool[0]; xx < MAX_L2CAP_LINKS;
81          xx++, p_lcb_cur++) {
82       if (p_lcb_cur == p_lcb) continue;
83 
84       if (p_lcb_cur->in_use) {
85         no_links = false;
86         p_lcb->link_role = HCI_ROLE_MASTER;
87         break;
88       }
89     }
90 
91     if (no_links) {
92       if (!btm_dev_support_switch(bd_addr))
93         p_lcb->link_role = HCI_ROLE_SLAVE;
94       else
95         p_lcb->link_role = l2cu_get_conn_role(p_lcb);
96     }
97 
98     /* Tell the other side we accept the connection */
99     btsnd_hcic_accept_conn(bd_addr, p_lcb->link_role);
100 
101     p_lcb->link_state = LST_CONNECTING;
102 
103     /* Start a timer waiting for connect complete */
104     alarm_set_on_mloop(p_lcb->l2c_lcb_timer, L2CAP_LINK_CONNECT_TIMEOUT_MS,
105                        l2c_lcb_timer_timeout, p_lcb);
106     return (true);
107   }
108 
109   /* We already had a link control block to the guy. Check what state it is in
110    */
111   if ((p_lcb->link_state == LST_CONNECTING) ||
112       (p_lcb->link_state == LST_CONNECT_HOLDING)) {
113     /* Connection collision. Accept the connection anyways. */
114 
115     if (!btm_dev_support_switch(bd_addr))
116       p_lcb->link_role = HCI_ROLE_SLAVE;
117     else
118       p_lcb->link_role = l2cu_get_conn_role(p_lcb);
119 
120     btsnd_hcic_accept_conn(bd_addr, p_lcb->link_role);
121 
122     p_lcb->link_state = LST_CONNECTING;
123     return (true);
124   } else if (p_lcb->link_state == LST_DISCONNECTING) {
125     /* In disconnecting state, reject the connection. */
126     btsnd_hcic_reject_conn(bd_addr, HCI_ERR_HOST_REJECT_DEVICE);
127   } else {
128     L2CAP_TRACE_ERROR(
129         "L2CAP got conn_req while connected (state:%d). Reject it",
130         p_lcb->link_state);
131     /* Reject the connection with ACL Connection Already exist reason */
132     btsnd_hcic_reject_conn(bd_addr, HCI_ERR_CONNECTION_EXISTS);
133   }
134   return (false);
135 }
136 
137 /*******************************************************************************
138  *
139  * Function         l2c_link_hci_conn_comp
140  *
141  * Description      This function is called when an HCI Connection Complete
142  *                  event is received.
143  *
144  * Returns          void
145  *
146  ******************************************************************************/
l2c_link_hci_conn_comp(uint8_t status,uint16_t handle,const RawAddress & p_bda)147 bool l2c_link_hci_conn_comp(uint8_t status, uint16_t handle,
148                             const RawAddress& 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   ci.bd_addr = p_bda;
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, allocate one */
164   if (p_lcb == nullptr) {
165     L2CAP_TRACE_WARNING("No available link control block, try allocate one");
166     p_lcb = l2cu_allocate_lcb(ci.bd_addr, false, BT_TRANSPORT_BR_EDR);
167     if (p_lcb == nullptr) {
168       L2CAP_TRACE_WARNING("%s: Failed to allocate an LCB", __func__);
169       return (false);
170     }
171     p_lcb->link_state = LST_CONNECTING;
172   }
173 
174   if ((p_lcb->link_state == LST_CONNECTED) &&
175       (status == HCI_ERR_CONNECTION_EXISTS)) {
176     L2CAP_TRACE_WARNING("%s: An ACL connection already exists. Handle:%d",
177                         __func__, handle);
178     return (true);
179   } else if (p_lcb->link_state != LST_CONNECTING) {
180     L2CAP_TRACE_ERROR("L2CAP got conn_comp in bad state: %d  status: 0x%d",
181                       p_lcb->link_state, status);
182 
183     if (status != HCI_SUCCESS) l2c_link_hci_disc_comp(p_lcb->handle, status);
184 
185     return (false);
186   }
187 
188   /* Save the handle */
189   p_lcb->handle = handle;
190 
191   if (ci.status == HCI_SUCCESS) {
192     /* Connected OK. Change state to connected */
193     p_lcb->link_state = LST_CONNECTED;
194 
195     /* Get the peer information if the l2cap flow-control/rtrans is supported */
196     l2cu_send_peer_info_req(p_lcb, L2CAP_EXTENDED_FEATURES_INFO_TYPE);
197 
198     /* Tell BTM Acl management about the link */
199     p_dev_info = btm_find_dev(p_bda);
200     if (p_dev_info != NULL)
201       btm_acl_created(ci.bd_addr, p_dev_info->dev_class,
202                       p_dev_info->sec_bd_name, handle, p_lcb->link_role,
203                       BT_TRANSPORT_BR_EDR);
204     else
205       btm_acl_created(ci.bd_addr, NULL, NULL, handle, p_lcb->link_role,
206                       BT_TRANSPORT_BR_EDR);
207 
208     BTM_SetLinkSuperTout(ci.bd_addr, btm_cb.btm_def_link_super_tout);
209 
210     /* If dedicated bonding do not process any further */
211     if (p_lcb->is_bonding) {
212       if (l2cu_start_post_bond_timer(handle)) return (true);
213     }
214 
215     /* Update the timeouts in the hold queue */
216     l2c_process_held_packets(false);
217 
218     alarm_cancel(p_lcb->l2c_lcb_timer);
219 
220     /* For all channels, send the event through their FSMs */
221     for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;
222          p_ccb = p_ccb->p_next_ccb) {
223       l2c_csm_execute(p_ccb, L2CEVT_LP_CONNECT_CFM, &ci);
224     }
225 
226     if (p_lcb->p_echo_rsp_cb) {
227       l2cu_send_peer_echo_req(p_lcb, NULL, 0);
228       alarm_set_on_mloop(p_lcb->l2c_lcb_timer, L2CAP_ECHO_RSP_TIMEOUT_MS,
229                          l2c_lcb_timer_timeout, p_lcb);
230     } else if (!p_lcb->ccb_queue.p_first_ccb) {
231       uint64_t timeout_ms = L2CAP_LINK_STARTUP_TOUT * 1000;
232       alarm_set_on_mloop(p_lcb->l2c_lcb_timer, timeout_ms,
233                          l2c_lcb_timer_timeout, p_lcb);
234     }
235   }
236   /* Max number of acl connections.                          */
237   /* If there's an lcb disconnecting set this one to holding */
238   else if ((ci.status == HCI_ERR_MAX_NUM_OF_CONNECTIONS) &&
239            l2cu_lcb_disconnecting()) {
240     p_lcb->link_state = LST_CONNECT_HOLDING;
241     p_lcb->handle = HCI_INVALID_HANDLE;
242   } else {
243     /* Just in case app decides to try again in the callback context */
244     p_lcb->link_state = LST_DISCONNECTING;
245 
246     /* Connection failed. For all channels, send the event through */
247     /* their FSMs. The CCBs should remove themselves from the LCB  */
248     for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;) {
249       tL2C_CCB* pn = p_ccb->p_next_ccb;
250 
251       l2c_csm_execute(p_ccb, L2CEVT_LP_CONNECT_CFM_NEG, &ci);
252 
253       p_ccb = pn;
254     }
255 
256     p_lcb->disc_reason = status;
257     /* Release the LCB */
258     if (p_lcb->ccb_queue.p_first_ccb == NULL)
259       l2cu_release_lcb(p_lcb);
260     else /* there are any CCBs remaining */
261     {
262       if (ci.status == HCI_ERR_CONNECTION_EXISTS) {
263         /* we are in collision situation, wait for connecttion request from
264          * controller */
265         p_lcb->link_state = LST_CONNECTING;
266       } else {
267         l2cu_create_conn_br_edr(p_lcb);
268       }
269     }
270   }
271   return (true);
272 }
273 
274 /*******************************************************************************
275  *
276  * Function         l2c_link_sec_comp
277  *
278  * Description      This function is called when required security procedures
279  *                  are completed.
280  *
281  * Returns          void
282  *
283  ******************************************************************************/
l2c_link_sec_comp(const RawAddress * p_bda,UNUSED_ATTR tBT_TRANSPORT transport,void * p_ref_data,uint8_t status)284 void l2c_link_sec_comp(const RawAddress* p_bda,
285                        UNUSED_ATTR tBT_TRANSPORT transport, void* p_ref_data,
286                        uint8_t status) {
287   l2c_link_sec_comp2(*p_bda, transport, p_ref_data, status);
288 }
289 
l2c_link_sec_comp2(const RawAddress & p_bda,UNUSED_ATTR tBT_TRANSPORT transport,void * p_ref_data,uint8_t status)290 void l2c_link_sec_comp2(const RawAddress& p_bda,
291                         UNUSED_ATTR tBT_TRANSPORT transport, void* p_ref_data,
292                         uint8_t status) {
293   tL2C_CONN_INFO ci;
294   tL2C_LCB* p_lcb;
295   tL2C_CCB* p_ccb;
296   tL2C_CCB* p_next_ccb;
297   uint8_t event;
298 
299   L2CAP_TRACE_DEBUG("%s: status=%d, p_ref_data=%p, BD_ADDR=%s", __func__,
300                     status, p_ref_data, p_bda.ToString().c_str());
301 
302   if (status == BTM_SUCCESS_NO_SECURITY) status = BTM_SUCCESS;
303 
304   /* Save the parameters */
305   ci.status = status;
306   ci.bd_addr = p_bda;
307 
308   p_lcb = l2cu_find_lcb_by_bd_addr(p_bda, transport);
309 
310   /* If we don't have one, this is an error */
311   if (!p_lcb) {
312     L2CAP_TRACE_WARNING("L2CAP got sec_comp for unknown BD_ADDR");
313     return;
314   }
315 
316   /* Match p_ccb with p_ref_data returned by sec manager */
317   for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; p_ccb = p_next_ccb) {
318     p_next_ccb = p_ccb->p_next_ccb;
319 
320     if (p_ccb == p_ref_data) {
321       switch (status) {
322         case BTM_SUCCESS:
323           event = L2CEVT_SEC_COMP;
324           break;
325 
326         case BTM_DELAY_CHECK:
327           /* start a timer - encryption change not received before L2CAP connect
328            * req */
329           alarm_set_on_mloop(p_ccb->l2c_ccb_timer,
330                              L2CAP_DELAY_CHECK_SM4_TIMEOUT_MS,
331                              l2c_ccb_timer_timeout, p_ccb);
332           return;
333 
334         default:
335           event = L2CEVT_SEC_COMP_NEG;
336       }
337       l2c_csm_execute(p_ccb, event, &ci);
338       break;
339     }
340   }
341 }
342 
343 /*******************************************************************************
344  *
345  * Function         l2c_link_hci_disc_comp
346  *
347  * Description      This function is called when an HCI Disconnect Complete
348  *                  event is received.
349  *
350  * Returns          true if the link is known about, else false
351  *
352  ******************************************************************************/
l2c_link_hci_disc_comp(uint16_t handle,uint8_t reason)353 bool l2c_link_hci_disc_comp(uint16_t handle, uint8_t reason) {
354   tL2C_LCB* p_lcb;
355   tL2C_CCB* p_ccb;
356   bool status = true;
357   bool lcb_is_free = true;
358   tBT_TRANSPORT transport = BT_TRANSPORT_BR_EDR;
359 
360   /* See if we have a link control block for the connection */
361   p_lcb = l2cu_find_lcb_by_handle(handle);
362 
363   /* If we don't have one, maybe an SCO link. Send to MM */
364   if (!p_lcb) {
365     status = false;
366   } else {
367     /* There can be a case when we rejected PIN code authentication */
368     /* otherwise save a new reason */
369     if (btm_cb.acl_disc_reason != HCI_ERR_HOST_REJECT_SECURITY)
370       btm_cb.acl_disc_reason = reason;
371 
372     p_lcb->disc_reason = btm_cb.acl_disc_reason;
373 
374     /* Just in case app decides to try again in the callback context */
375     p_lcb->link_state = LST_DISCONNECTING;
376 
377     /* Check for BLE and handle that differently */
378     if (p_lcb->transport == BT_TRANSPORT_LE)
379       btm_ble_update_link_topology_mask(p_lcb->link_role, false);
380     /* Link is disconnected. For all channels, send the event through */
381     /* their FSMs. The CCBs should remove themselves from the LCB     */
382     for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;) {
383       tL2C_CCB* pn = p_ccb->p_next_ccb;
384 
385       /* Keep connect pending control block (if exists)
386        * Possible Race condition when a reconnect occurs
387        * on the channel during a disconnect of link. This
388        * ccb will be automatically retried after link disconnect
389        * arrives
390        */
391       if (p_ccb != p_lcb->p_pending_ccb) {
392         l2c_csm_execute(p_ccb, L2CEVT_LP_DISCONNECT_IND, &reason);
393       }
394       p_ccb = pn;
395     }
396 
397     if (p_lcb->transport == BT_TRANSPORT_BR_EDR)
398       /* Tell SCO management to drop any SCOs on this ACL */
399       btm_sco_acl_removed(&p_lcb->remote_bd_addr);
400 
401     /* If waiting for disconnect and reconnect is pending start the reconnect
402        now
403        race condition where layer above issued connect request on link that was
404        disconnecting
405      */
406     if (p_lcb->ccb_queue.p_first_ccb != NULL || p_lcb->p_pending_ccb) {
407       L2CAP_TRACE_DEBUG(
408           "l2c_link_hci_disc_comp: Restarting pending ACL request");
409       /* Release any held buffers */
410       while (!list_is_empty(p_lcb->link_xmit_data_q)) {
411         BT_HDR* p_buf =
412             static_cast<BT_HDR*>(list_front(p_lcb->link_xmit_data_q));
413         list_remove(p_lcb->link_xmit_data_q, p_buf);
414         osi_free(p_buf);
415       }
416       transport = p_lcb->transport;
417       /* for LE link, always drop and re-open to ensure to get LE remote feature
418        */
419       if (p_lcb->transport == BT_TRANSPORT_LE) {
420         btm_acl_removed(p_lcb->remote_bd_addr, p_lcb->transport);
421       } else {
422 #if (L2CAP_NUM_FIXED_CHNLS > 0)
423         /* If we are going to re-use the LCB without dropping it, release all
424         fixed channels
425         here */
426         int xx;
427         for (xx = 0; xx < L2CAP_NUM_FIXED_CHNLS; xx++) {
428           if (p_lcb->p_fixed_ccbs[xx] &&
429               p_lcb->p_fixed_ccbs[xx] != p_lcb->p_pending_ccb) {
430             (*l2cb.fixed_reg[xx].pL2CA_FixedConn_Cb)(
431                 xx + L2CAP_FIRST_FIXED_CHNL, p_lcb->remote_bd_addr, false,
432                 p_lcb->disc_reason, p_lcb->transport);
433             if (p_lcb->p_fixed_ccbs[xx] == NULL) {
434               L2CAP_TRACE_ERROR(
435                   "%s: unexpected p_fixed_ccbs[%d] is NULL remote_bd_addr = %s "
436                   "p_lcb = %p in_use = %d link_state = %d handle = %d "
437                   "link_role = %d is_bonding = %d disc_reason = %d transport = "
438                   "%d",
439                   __func__, xx, p_lcb->remote_bd_addr.ToString().c_str(), p_lcb,
440                   p_lcb->in_use, p_lcb->link_state, p_lcb->handle,
441                   p_lcb->link_role, p_lcb->is_bonding, p_lcb->disc_reason,
442                   p_lcb->transport);
443             }
444             CHECK(p_lcb->p_fixed_ccbs[xx] != NULL);
445             l2cu_release_ccb(p_lcb->p_fixed_ccbs[xx]);
446 
447             p_lcb->p_fixed_ccbs[xx] = NULL;
448           }
449         }
450 #endif
451       }
452       if (p_lcb->transport == BT_TRANSPORT_LE) {
453         if (l2cu_create_conn_le(p_lcb))
454           lcb_is_free = false; /* still using this lcb */
455       } else {
456         if (l2cu_create_conn_br_edr(p_lcb))
457           lcb_is_free = false; /* still using this lcb */
458       }
459     }
460 
461     p_lcb->p_pending_ccb = NULL;
462 
463     /* Release the LCB */
464     if (lcb_is_free) l2cu_release_lcb(p_lcb);
465   }
466 
467   /* Now that we have a free acl connection, see if any lcbs are pending */
468   if (lcb_is_free &&
469       ((p_lcb = l2cu_find_lcb_by_state(LST_CONNECT_HOLDING)) != NULL)) {
470     /* we found one-- create a connection */
471     l2cu_create_conn_br_edr(p_lcb);
472   }
473 
474   return status;
475 }
476 
477 /*******************************************************************************
478  *
479  * Function         l2c_link_hci_qos_violation
480  *
481  * Description      This function is called when an HCI QOS Violation
482  *                  event is received.
483  *
484  * Returns          true if the link is known about, else false
485  *
486  ******************************************************************************/
l2c_link_hci_qos_violation(uint16_t handle)487 bool l2c_link_hci_qos_violation(uint16_t handle) {
488   tL2C_LCB* p_lcb;
489   tL2C_CCB* p_ccb;
490 
491   /* See if we have a link control block for the connection */
492   p_lcb = l2cu_find_lcb_by_handle(handle);
493 
494   /* If we don't have one, maybe an SCO link. */
495   if (!p_lcb) return (false);
496 
497   /* For all channels, tell the upper layer about it */
498   for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; p_ccb = p_ccb->p_next_ccb) {
499     if (p_ccb->p_rcb->api.pL2CA_QoSViolationInd_Cb)
500       l2c_csm_execute(p_ccb, L2CEVT_LP_QOS_VIOLATION_IND, NULL);
501   }
502 
503   return (true);
504 }
505 
506 /*******************************************************************************
507  *
508  * Function         l2c_link_timeout
509  *
510  * Description      This function is called when a link timer expires
511  *
512  * Returns          void
513  *
514  ******************************************************************************/
l2c_link_timeout(tL2C_LCB * p_lcb)515 void l2c_link_timeout(tL2C_LCB* p_lcb) {
516   tL2C_CCB* p_ccb;
517   tBTM_STATUS rc;
518 
519   L2CAP_TRACE_EVENT(
520       "L2CAP - l2c_link_timeout() link state %d first CCB %p is_bonding:%d",
521       p_lcb->link_state, p_lcb->ccb_queue.p_first_ccb, p_lcb->is_bonding);
522 
523   /* If link was connecting or disconnecting, clear all channels and drop the
524    * LCB */
525   if ((p_lcb->link_state == LST_CONNECTING_WAIT_SWITCH) ||
526       (p_lcb->link_state == LST_CONNECTING) ||
527       (p_lcb->link_state == LST_CONNECT_HOLDING) ||
528       (p_lcb->link_state == LST_DISCONNECTING)) {
529     p_lcb->p_pending_ccb = NULL;
530 
531     /* For all channels, send a disconnect indication event through */
532     /* their FSMs. The CCBs should remove themselves from the LCB   */
533     for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;) {
534       tL2C_CCB* pn = p_ccb->p_next_ccb;
535 
536       l2c_csm_execute(p_ccb, L2CEVT_LP_DISCONNECT_IND, NULL);
537 
538       p_ccb = pn;
539     }
540 
541     /* Release the LCB */
542     l2cu_release_lcb(p_lcb);
543   }
544 
545   /* If link is connected, check for inactivity timeout */
546   if (p_lcb->link_state == LST_CONNECTED) {
547     /* Check for ping outstanding */
548     if (p_lcb->p_echo_rsp_cb) {
549       tL2CA_ECHO_RSP_CB* p_cb = p_lcb->p_echo_rsp_cb;
550 
551       /* Zero out the callback in case app immediately calls us again */
552       p_lcb->p_echo_rsp_cb = NULL;
553 
554       (*p_cb)(L2CAP_PING_RESULT_NO_RESP);
555 
556       L2CAP_TRACE_WARNING("L2CAP - ping timeout");
557 
558       /* For all channels, send a disconnect indication event through */
559       /* their FSMs. The CCBs should remove themselves from the LCB   */
560       for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;) {
561         tL2C_CCB* pn = p_ccb->p_next_ccb;
562 
563         l2c_csm_execute(p_ccb, L2CEVT_LP_DISCONNECT_IND, NULL);
564 
565         p_ccb = pn;
566       }
567     }
568 
569     /* If no channels in use, drop the link. */
570     if (!p_lcb->ccb_queue.p_first_ccb) {
571       uint64_t timeout_ms;
572       bool start_timeout = true;
573 
574       rc = btm_sec_disconnect(p_lcb->handle, HCI_ERR_PEER_USER);
575 
576       if (rc == BTM_CMD_STORED) {
577         /* Security Manager will take care of disconnecting, state will be
578          * updated at that time */
579         start_timeout = false;
580       } else if (rc == BTM_CMD_STARTED) {
581         p_lcb->link_state = LST_DISCONNECTING;
582         timeout_ms = L2CAP_LINK_DISCONNECT_TIMEOUT_MS;
583       } else if (rc == BTM_SUCCESS) {
584         l2cu_process_fixed_disc_cback(p_lcb);
585         /* BTM SEC will make sure that link is release (probably after pairing
586          * is done) */
587         p_lcb->link_state = LST_DISCONNECTING;
588         start_timeout = false;
589       } else if (rc == BTM_BUSY) {
590         /* BTM is still executing security process. Let lcb stay as connected */
591         start_timeout = false;
592       } else if (p_lcb->is_bonding) {
593         btsnd_hcic_disconnect(p_lcb->handle, HCI_ERR_PEER_USER);
594         l2cu_process_fixed_disc_cback(p_lcb);
595         p_lcb->link_state = LST_DISCONNECTING;
596         timeout_ms = L2CAP_LINK_DISCONNECT_TIMEOUT_MS;
597       } else {
598         /* probably no buffer to send disconnect */
599         timeout_ms = BT_1SEC_TIMEOUT_MS;
600       }
601 
602       if (start_timeout) {
603         alarm_set_on_mloop(p_lcb->l2c_lcb_timer, timeout_ms,
604                            l2c_lcb_timer_timeout, p_lcb);
605       }
606     } else {
607       /* Check in case we were flow controlled */
608       l2c_link_check_send_pkts(p_lcb, NULL, NULL);
609     }
610   }
611 }
612 
613 /*******************************************************************************
614  *
615  * Function         l2c_info_resp_timer_timeout
616  *
617  * Description      This function is called when an info request times out
618  *
619  * Returns          void
620  *
621  ******************************************************************************/
l2c_info_resp_timer_timeout(void * data)622 void l2c_info_resp_timer_timeout(void* data) {
623   tL2C_LCB* p_lcb = (tL2C_LCB*)data;
624   tL2C_CCB* p_ccb;
625   tL2C_CONN_INFO ci;
626 
627   /* If we timed out waiting for info response, just continue using basic if
628    * allowed */
629   if (p_lcb->w4_info_rsp) {
630     /* If waiting for security complete, restart the info response timer */
631     for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;
632          p_ccb = p_ccb->p_next_ccb) {
633       if ((p_ccb->chnl_state == CST_ORIG_W4_SEC_COMP) ||
634           (p_ccb->chnl_state == CST_TERM_W4_SEC_COMP)) {
635         alarm_set_on_mloop(p_lcb->info_resp_timer,
636                            L2CAP_WAIT_INFO_RSP_TIMEOUT_MS,
637                            l2c_info_resp_timer_timeout, p_lcb);
638         return;
639       }
640     }
641 
642     p_lcb->w4_info_rsp = false;
643 
644     /* If link is in process of being brought up */
645     if ((p_lcb->link_state != LST_DISCONNECTED) &&
646         (p_lcb->link_state != LST_DISCONNECTING)) {
647       /* Notify active channels that peer info is finished */
648       if (p_lcb->ccb_queue.p_first_ccb) {
649         ci.status = HCI_SUCCESS;
650         ci.bd_addr = p_lcb->remote_bd_addr;
651 
652         for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;
653              p_ccb = p_ccb->p_next_ccb) {
654           l2c_csm_execute(p_ccb, L2CEVT_L2CAP_INFO_RSP, &ci);
655         }
656       }
657     }
658   }
659 }
660 
661 /*******************************************************************************
662  *
663  * Function         l2c_link_adjust_allocation
664  *
665  * Description      This function is called when a link is created or removed
666  *                  to calculate the amount of packets each link may send to
667  *                  the HCI without an ack coming back.
668  *
669  *                  Currently, this is a simple allocation, dividing the
670  *                  number of Controller Packets by the number of links. In
671  *                  the future, QOS configuration should be examined.
672  *
673  * Returns          void
674  *
675  ******************************************************************************/
l2c_link_adjust_allocation(void)676 void l2c_link_adjust_allocation(void) {
677   uint16_t qq, yy, qq_remainder;
678   tL2C_LCB* p_lcb;
679   uint16_t hi_quota, low_quota;
680   uint16_t num_lowpri_links = 0;
681   uint16_t num_hipri_links = 0;
682   uint16_t controller_xmit_quota = l2cb.num_lm_acl_bufs;
683   uint16_t high_pri_link_quota = L2CAP_HIGH_PRI_MIN_XMIT_QUOTA_A;
684   bool is_share_buffer =
685       (l2cb.num_lm_ble_bufs == L2C_DEF_NUM_BLE_BUF_SHARED) ? true : false;
686 
687   /* If no links active, reset buffer quotas and controller buffers */
688   if (l2cb.num_links_active == 0) {
689     l2cb.controller_xmit_window = l2cb.num_lm_acl_bufs;
690     l2cb.round_robin_quota = l2cb.round_robin_unacked = 0;
691     return;
692   }
693 
694   /* First, count the links */
695   for (yy = 0, p_lcb = &l2cb.lcb_pool[0]; yy < MAX_L2CAP_LINKS; yy++, p_lcb++) {
696     if (p_lcb->in_use &&
697         (is_share_buffer || p_lcb->transport != BT_TRANSPORT_LE)) {
698       if (p_lcb->acl_priority == L2CAP_PRIORITY_HIGH)
699         num_hipri_links++;
700       else
701         num_lowpri_links++;
702     }
703   }
704 
705   /* now adjust high priority link quota */
706   low_quota = num_lowpri_links ? 1 : 0;
707   while ((num_hipri_links * high_pri_link_quota + low_quota) >
708          controller_xmit_quota)
709     high_pri_link_quota--;
710 
711   /* Work out the xmit quota and buffer quota high and low priorities */
712   hi_quota = num_hipri_links * high_pri_link_quota;
713   low_quota =
714       (hi_quota < controller_xmit_quota) ? controller_xmit_quota - hi_quota : 1;
715 
716   /* Work out and save the HCI xmit quota for each low priority link */
717 
718   /* If each low priority link cannot have at least one buffer */
719   if (num_lowpri_links > low_quota) {
720     l2cb.round_robin_quota = low_quota;
721     qq = qq_remainder = 1;
722   }
723   /* If each low priority link can have at least one buffer */
724   else if (num_lowpri_links > 0) {
725     l2cb.round_robin_quota = 0;
726     l2cb.round_robin_unacked = 0;
727     qq = low_quota / num_lowpri_links;
728     qq_remainder = low_quota % num_lowpri_links;
729   }
730   /* If no low priority link */
731   else {
732     l2cb.round_robin_quota = 0;
733     l2cb.round_robin_unacked = 0;
734     qq = qq_remainder = 1;
735   }
736 
737   L2CAP_TRACE_EVENT(
738       "l2c_link_adjust_allocation  num_hipri: %u  num_lowpri: %u  low_quota: "
739       "%u  round_robin_quota: %u  qq: %u",
740       num_hipri_links, num_lowpri_links, low_quota, l2cb.round_robin_quota, qq);
741 
742   /* Now, assign the quotas to each link */
743   for (yy = 0, p_lcb = &l2cb.lcb_pool[0]; yy < MAX_L2CAP_LINKS; yy++, p_lcb++) {
744     if (p_lcb->in_use &&
745         (is_share_buffer || p_lcb->transport != BT_TRANSPORT_LE)) {
746       if (p_lcb->acl_priority == L2CAP_PRIORITY_HIGH) {
747         p_lcb->link_xmit_quota = high_pri_link_quota;
748       } else {
749         /* Safety check in case we switched to round-robin with something
750          * outstanding */
751         /* if sent_not_acked is added into round_robin_unacked then don't add it
752          * again */
753         /* l2cap keeps updating sent_not_acked for exiting from round robin */
754         if ((p_lcb->link_xmit_quota > 0) && (qq == 0))
755           l2cb.round_robin_unacked += p_lcb->sent_not_acked;
756 
757         p_lcb->link_xmit_quota = qq;
758         if (qq_remainder > 0) {
759           p_lcb->link_xmit_quota++;
760           qq_remainder--;
761         }
762       }
763 
764       L2CAP_TRACE_EVENT(
765           "l2c_link_adjust_allocation LCB %d   Priority: %d  XmitQuota: %d", yy,
766           p_lcb->acl_priority, p_lcb->link_xmit_quota);
767 
768       L2CAP_TRACE_EVENT("        SentNotAcked: %d  RRUnacked: %d",
769                         p_lcb->sent_not_acked, l2cb.round_robin_unacked);
770 
771       /* There is a special case where we have readjusted the link quotas and */
772       /* this link may have sent anything but some other link sent packets so */
773       /* so we may need a timer to kick off this link's transmissions. */
774       if ((p_lcb->link_state == LST_CONNECTED) &&
775           (!list_is_empty(p_lcb->link_xmit_data_q)) &&
776           (p_lcb->sent_not_acked < p_lcb->link_xmit_quota)) {
777         alarm_set_on_mloop(p_lcb->l2c_lcb_timer,
778                            L2CAP_LINK_FLOW_CONTROL_TIMEOUT_MS,
779                            l2c_lcb_timer_timeout, p_lcb);
780       }
781     }
782   }
783 }
784 
785 /*******************************************************************************
786  *
787  * Function         l2c_link_adjust_chnl_allocation
788  *
789  * Description      This function is called to calculate the amount of packets
790  *                  each non-F&EC channel may have outstanding.
791  *
792  *                  Currently, this is a simple allocation, dividing the number
793  *                  of packets allocated to the link by the number of channels.
794  *                  In the future, QOS configuration should be examined.
795  *
796  * Returns          void
797  *
798  ******************************************************************************/
l2c_link_adjust_chnl_allocation(void)799 void l2c_link_adjust_chnl_allocation(void) {
800   uint8_t xx;
801 
802   L2CAP_TRACE_DEBUG("%s", __func__);
803 
804   /* assign buffer quota to each channel based on its data rate requirement */
805   for (xx = 0; xx < MAX_L2CAP_CHANNELS; xx++) {
806     tL2C_CCB* p_ccb = l2cb.ccb_pool + xx;
807 
808     if (!p_ccb->in_use) continue;
809 
810     tL2CAP_CHNL_DATA_RATE data_rate = p_ccb->tx_data_rate + p_ccb->rx_data_rate;
811     p_ccb->buff_quota = L2CAP_CBB_DEFAULT_DATA_RATE_BUFF_QUOTA * data_rate;
812     L2CAP_TRACE_EVENT(
813         "CID:0x%04x FCR Mode:%u Priority:%u TxDataRate:%u RxDataRate:%u "
814         "Quota:%u",
815         p_ccb->local_cid, p_ccb->peer_cfg.fcr.mode, p_ccb->ccb_priority,
816         p_ccb->tx_data_rate, p_ccb->rx_data_rate, p_ccb->buff_quota);
817 
818     /* quota may be change so check congestion */
819     l2cu_check_channel_congestion(p_ccb);
820   }
821 }
822 
823 /*******************************************************************************
824  *
825  * Function         l2c_link_processs_num_bufs
826  *
827  * Description      This function is called when a "controller buffer size"
828  *                  event is first received from the controller. It updates
829  *                  the L2CAP values.
830  *
831  * Returns          void
832  *
833  ******************************************************************************/
l2c_link_processs_num_bufs(uint16_t num_lm_acl_bufs)834 void l2c_link_processs_num_bufs(uint16_t num_lm_acl_bufs) {
835   l2cb.num_lm_acl_bufs = l2cb.controller_xmit_window = num_lm_acl_bufs;
836 }
837 
838 /*******************************************************************************
839  *
840  * Function         l2c_link_pkts_rcvd
841  *
842  * Description      This function is called from the HCI transport when it is
843  *                  time to send a "Host ready for packets" command. This is
844  *                  only when host to controller flow control is used. It fills
845  *                  in the arrays of numbers of packets and handles.
846  *
847  * Returns          count of number of entries filled in
848  *
849  ******************************************************************************/
l2c_link_pkts_rcvd(UNUSED_ATTR uint16_t * num_pkts,UNUSED_ATTR uint16_t * handles)850 uint8_t l2c_link_pkts_rcvd(UNUSED_ATTR uint16_t* num_pkts,
851                            UNUSED_ATTR uint16_t* handles) {
852   uint8_t num_found = 0;
853 
854   return (num_found);
855 }
856 
857 /*******************************************************************************
858  *
859  * Function         l2c_link_role_changed
860  *
861  * Description      This function is called whan a link's master/slave role
862  *                  change event is received. It simply updates the link control
863  *                  block.
864  *
865  * Returns          void
866  *
867  ******************************************************************************/
l2c_link_role_changed(const RawAddress * bd_addr,uint8_t new_role,uint8_t hci_status)868 void l2c_link_role_changed(const RawAddress* bd_addr, uint8_t new_role,
869                            uint8_t hci_status) {
870   tL2C_LCB* p_lcb;
871   int xx;
872 
873   /* Make sure not called from HCI Command Status (bd_addr and new_role are
874    * invalid) */
875   if (bd_addr) {
876     /* If here came form hci role change event */
877     p_lcb = l2cu_find_lcb_by_bd_addr(*bd_addr, BT_TRANSPORT_BR_EDR);
878     if (p_lcb) {
879       p_lcb->link_role = new_role;
880 
881       /* Reset high priority link if needed */
882       if (hci_status == HCI_SUCCESS)
883         l2cu_set_acl_priority(*bd_addr, p_lcb->acl_priority, true);
884     }
885   }
886 
887   /* Check if any LCB was waiting for switch to be completed */
888   for (xx = 0, p_lcb = &l2cb.lcb_pool[0]; xx < MAX_L2CAP_LINKS; xx++, p_lcb++) {
889     if ((p_lcb->in_use) && (p_lcb->link_state == LST_CONNECTING_WAIT_SWITCH)) {
890       l2cu_create_conn_after_switch(p_lcb);
891     }
892   }
893 }
894 
895 /*******************************************************************************
896  *
897  * Function         l2c_pin_code_request
898  *
899  * Description      This function is called whan a pin-code request is received
900  *                  on a connection. If there are no channels active yet on the
901  *                  link, it extends the link first connection timer.  Make sure
902  *                  that inactivity timer is not extended if PIN code happens
903  *                  to be after last ccb released.
904  *
905  * Returns          void
906  *
907  ******************************************************************************/
l2c_pin_code_request(const RawAddress & bd_addr)908 void l2c_pin_code_request(const RawAddress& bd_addr) {
909   tL2C_LCB* p_lcb = l2cu_find_lcb_by_bd_addr(bd_addr, BT_TRANSPORT_BR_EDR);
910 
911   if ((p_lcb) && (!p_lcb->ccb_queue.p_first_ccb)) {
912     alarm_set_on_mloop(p_lcb->l2c_lcb_timer, L2CAP_LINK_CONNECT_EXT_TIMEOUT_MS,
913                        l2c_lcb_timer_timeout, p_lcb);
914   }
915 }
916 
917 #if (L2CAP_WAKE_PARKED_LINK == TRUE)
918 /*******************************************************************************
919  *
920  * Function         l2c_link_check_power_mode
921  *
922  * Description      This function is called to check power mode.
923  *
924  * Returns          true if link is going to be active from park
925  *                  false if nothing to send or not in park mode
926  *
927  ******************************************************************************/
l2c_link_check_power_mode(tL2C_LCB * p_lcb)928 bool l2c_link_check_power_mode(tL2C_LCB* p_lcb) {
929   tBTM_PM_MODE mode;
930   tL2C_CCB* p_ccb;
931   bool need_to_active = false;
932 
933   /*
934    * We only switch park to active only if we have unsent packets
935    */
936   if (list_is_empty(p_lcb->link_xmit_data_q)) {
937     for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;
938          p_ccb = p_ccb->p_next_ccb) {
939       if (!fixed_queue_is_empty(p_ccb->xmit_hold_q)) {
940         need_to_active = true;
941         break;
942       }
943     }
944   } else
945     need_to_active = true;
946 
947   /* if we have packets to send */
948   if (need_to_active) {
949     /* check power mode */
950     if (BTM_ReadPowerMode(p_lcb->remote_bd_addr, &mode) == BTM_SUCCESS) {
951       if (mode == BTM_PM_STS_PENDING) {
952         L2CAP_TRACE_DEBUG("LCB(0x%x) is in PM pending state", p_lcb->handle);
953 
954         return true;
955       }
956     }
957   }
958   return false;
959 }
960 #endif /* L2CAP_WAKE_PARKED_LINK == TRUE) */
961 
962 /*******************************************************************************
963  *
964  * Function         l2c_link_check_send_pkts
965  *
966  * Description      This function is called to check if it can send packets
967  *                  to the Host Controller. It may be passed the address of
968  *                  a packet to send.
969  *
970  * Returns          void
971  *
972  ******************************************************************************/
l2c_link_check_send_pkts(tL2C_LCB * p_lcb,tL2C_CCB * p_ccb,BT_HDR * p_buf)973 void l2c_link_check_send_pkts(tL2C_LCB* p_lcb, tL2C_CCB* p_ccb, BT_HDR* p_buf) {
974   int xx;
975   bool single_write = false;
976 
977   /* Save the channel ID for faster counting */
978   if (p_buf) {
979     if (p_ccb != NULL) {
980       p_buf->event = p_ccb->local_cid;
981       single_write = true;
982     } else
983       p_buf->event = 0;
984 
985     p_buf->layer_specific = 0;
986     list_append(p_lcb->link_xmit_data_q, p_buf);
987 
988     if (p_lcb->link_xmit_quota == 0) {
989       if (p_lcb->transport == BT_TRANSPORT_LE)
990         l2cb.ble_check_round_robin = true;
991       else
992         l2cb.check_round_robin = true;
993     }
994   }
995 
996   /* If this is called from uncongested callback context break recursive
997   *calling.
998   ** This LCB will be served when receiving number of completed packet event.
999   */
1000   if (l2cb.is_cong_cback_context) return;
1001 
1002   /* If we are in a scenario where there are not enough buffers for each link to
1003   ** have at least 1, then do a round-robin for all the LCBs
1004   */
1005   if ((p_lcb == NULL) || (p_lcb->link_xmit_quota == 0)) {
1006     if (p_lcb == NULL)
1007       p_lcb = l2cb.lcb_pool;
1008     else if (!single_write)
1009       p_lcb++;
1010 
1011     /* Loop through, starting at the next */
1012     for (xx = 0; xx < MAX_L2CAP_LINKS; xx++, p_lcb++) {
1013       /* Check for wraparound */
1014       if (p_lcb == &l2cb.lcb_pool[MAX_L2CAP_LINKS]) p_lcb = &l2cb.lcb_pool[0];
1015 
1016       /* If controller window is full, nothing to do */
1017       if (((l2cb.controller_xmit_window == 0 ||
1018             (l2cb.round_robin_unacked >= l2cb.round_robin_quota)) &&
1019            (p_lcb->transport == BT_TRANSPORT_BR_EDR)) ||
1020           (p_lcb->transport == BT_TRANSPORT_LE &&
1021            (l2cb.ble_round_robin_unacked >= l2cb.ble_round_robin_quota ||
1022             l2cb.controller_le_xmit_window == 0)))
1023         continue;
1024 
1025       if ((!p_lcb->in_use) || (p_lcb->partial_segment_being_sent) ||
1026           (p_lcb->link_state != LST_CONNECTED) ||
1027           (p_lcb->link_xmit_quota != 0) || (L2C_LINK_CHECK_POWER_MODE(p_lcb)))
1028         continue;
1029 
1030       /* See if we can send anything from the Link Queue */
1031       if (!list_is_empty(p_lcb->link_xmit_data_q)) {
1032         p_buf = (BT_HDR*)list_front(p_lcb->link_xmit_data_q);
1033         list_remove(p_lcb->link_xmit_data_q, p_buf);
1034         l2c_link_send_to_lower(p_lcb, p_buf, NULL);
1035       } else if (single_write) {
1036         /* If only doing one write, break out */
1037         break;
1038       }
1039       /* If nothing on the link queue, check the channel queue */
1040       else {
1041         tL2C_TX_COMPLETE_CB_INFO cbi;
1042         p_buf = l2cu_get_next_buffer_to_send(p_lcb, &cbi);
1043         if (p_buf != NULL) {
1044           l2c_link_send_to_lower(p_lcb, p_buf, &cbi);
1045         }
1046       }
1047     }
1048 
1049     /* If we finished without using up our quota, no need for a safety check */
1050     if ((l2cb.controller_xmit_window > 0) &&
1051         (l2cb.round_robin_unacked < l2cb.round_robin_quota) &&
1052         (p_lcb->transport == BT_TRANSPORT_BR_EDR))
1053       l2cb.check_round_robin = false;
1054 
1055     if ((l2cb.controller_le_xmit_window > 0) &&
1056         (l2cb.ble_round_robin_unacked < l2cb.ble_round_robin_quota) &&
1057         (p_lcb->transport == BT_TRANSPORT_LE))
1058       l2cb.ble_check_round_robin = false;
1059   } else /* if this is not round-robin service */
1060   {
1061     /* If a partial segment is being sent, can't send anything else */
1062     if ((p_lcb->partial_segment_being_sent) ||
1063         (p_lcb->link_state != LST_CONNECTED) ||
1064         (L2C_LINK_CHECK_POWER_MODE(p_lcb)))
1065       return;
1066 
1067     /* See if we can send anything from the link queue */
1068     while (((l2cb.controller_xmit_window != 0 &&
1069              (p_lcb->transport == BT_TRANSPORT_BR_EDR)) ||
1070             (l2cb.controller_le_xmit_window != 0 &&
1071              (p_lcb->transport == BT_TRANSPORT_LE))) &&
1072            (p_lcb->sent_not_acked < p_lcb->link_xmit_quota)) {
1073       if (list_is_empty(p_lcb->link_xmit_data_q)) break;
1074 
1075       p_buf = (BT_HDR*)list_front(p_lcb->link_xmit_data_q);
1076       list_remove(p_lcb->link_xmit_data_q, p_buf);
1077       if (!l2c_link_send_to_lower(p_lcb, p_buf, NULL)) break;
1078     }
1079 
1080     if (!single_write) {
1081       /* See if we can send anything for any channel */
1082       while (((l2cb.controller_xmit_window != 0 &&
1083                (p_lcb->transport == BT_TRANSPORT_BR_EDR)) ||
1084               (l2cb.controller_le_xmit_window != 0 &&
1085                (p_lcb->transport == BT_TRANSPORT_LE))) &&
1086              (p_lcb->sent_not_acked < p_lcb->link_xmit_quota)) {
1087         tL2C_TX_COMPLETE_CB_INFO cbi;
1088         p_buf = l2cu_get_next_buffer_to_send(p_lcb, &cbi);
1089         if (p_buf == NULL) break;
1090 
1091         if (!l2c_link_send_to_lower(p_lcb, p_buf, &cbi)) break;
1092       }
1093     }
1094 
1095     /* There is a special case where we have readjusted the link quotas and  */
1096     /* this link may have sent anything but some other link sent packets so  */
1097     /* so we may need a timer to kick off this link's transmissions.         */
1098     if ((!list_is_empty(p_lcb->link_xmit_data_q)) &&
1099         (p_lcb->sent_not_acked < p_lcb->link_xmit_quota)) {
1100       alarm_set_on_mloop(p_lcb->l2c_lcb_timer,
1101                          L2CAP_LINK_FLOW_CONTROL_TIMEOUT_MS,
1102                          l2c_lcb_timer_timeout, p_lcb);
1103     }
1104   }
1105 }
1106 
1107 /*******************************************************************************
1108  *
1109  * Function         l2c_link_send_to_lower
1110  *
1111  * Description      This function queues the buffer for HCI transmission
1112  *
1113  * Returns          true for success, false for fail
1114  *
1115  ******************************************************************************/
l2c_link_send_to_lower(tL2C_LCB * p_lcb,BT_HDR * p_buf,tL2C_TX_COMPLETE_CB_INFO * p_cbi)1116 static bool l2c_link_send_to_lower(tL2C_LCB* p_lcb, BT_HDR* p_buf,
1117                                    tL2C_TX_COMPLETE_CB_INFO* p_cbi) {
1118   uint16_t num_segs;
1119   uint16_t xmit_window, acl_data_size;
1120   const controller_t* controller = controller_get_interface();
1121 
1122   if ((p_buf->len <= controller->get_acl_packet_size_classic() &&
1123        (p_lcb->transport == BT_TRANSPORT_BR_EDR)) ||
1124       ((p_lcb->transport == BT_TRANSPORT_LE) &&
1125        (p_buf->len <= controller->get_acl_packet_size_ble()))) {
1126     if (p_lcb->link_xmit_quota == 0) {
1127       if (p_lcb->transport == BT_TRANSPORT_LE)
1128         l2cb.ble_round_robin_unacked++;
1129       else
1130         l2cb.round_robin_unacked++;
1131     }
1132     p_lcb->sent_not_acked++;
1133     p_buf->layer_specific = 0;
1134 
1135     if (p_lcb->transport == BT_TRANSPORT_LE) {
1136       l2cb.controller_le_xmit_window--;
1137       bte_main_hci_send(
1138           p_buf, (uint16_t)(BT_EVT_TO_LM_HCI_ACL | LOCAL_BLE_CONTROLLER_ID));
1139     } else {
1140       l2cb.controller_xmit_window--;
1141       bte_main_hci_send(p_buf, BT_EVT_TO_LM_HCI_ACL);
1142     }
1143   } else {
1144     if (p_lcb->transport == BT_TRANSPORT_LE) {
1145       acl_data_size = controller->get_acl_data_size_ble();
1146       xmit_window = l2cb.controller_le_xmit_window;
1147 
1148     } else {
1149       acl_data_size = controller->get_acl_data_size_classic();
1150       xmit_window = l2cb.controller_xmit_window;
1151     }
1152     num_segs = (p_buf->len - HCI_DATA_PREAMBLE_SIZE + acl_data_size - 1) /
1153                acl_data_size;
1154 
1155     /* If doing round-robin, then only 1 segment each time */
1156     if (p_lcb->link_xmit_quota == 0) {
1157       num_segs = 1;
1158       p_lcb->partial_segment_being_sent = true;
1159     } else {
1160       /* Multi-segment packet. Make sure it can fit */
1161       if (num_segs > xmit_window) {
1162         num_segs = xmit_window;
1163         p_lcb->partial_segment_being_sent = true;
1164       }
1165 
1166       if (num_segs > (p_lcb->link_xmit_quota - p_lcb->sent_not_acked)) {
1167         num_segs = (p_lcb->link_xmit_quota - p_lcb->sent_not_acked);
1168         p_lcb->partial_segment_being_sent = true;
1169       }
1170     }
1171 
1172     p_buf->layer_specific = num_segs;
1173     if (p_lcb->transport == BT_TRANSPORT_LE) {
1174       l2cb.controller_le_xmit_window -= num_segs;
1175       if (p_lcb->link_xmit_quota == 0) l2cb.ble_round_robin_unacked += num_segs;
1176     } else {
1177       l2cb.controller_xmit_window -= num_segs;
1178 
1179       if (p_lcb->link_xmit_quota == 0) l2cb.round_robin_unacked += num_segs;
1180     }
1181 
1182     p_lcb->sent_not_acked += num_segs;
1183     if (p_lcb->transport == BT_TRANSPORT_LE) {
1184       bte_main_hci_send(
1185           p_buf, (uint16_t)(BT_EVT_TO_LM_HCI_ACL | LOCAL_BLE_CONTROLLER_ID));
1186     } else {
1187       bte_main_hci_send(p_buf, BT_EVT_TO_LM_HCI_ACL);
1188     }
1189   }
1190 
1191 #if (L2CAP_HCI_FLOW_CONTROL_DEBUG == TRUE)
1192   if (p_lcb->transport == BT_TRANSPORT_LE) {
1193     L2CAP_TRACE_DEBUG(
1194         "TotalWin=%d,Hndl=0x%x,Quota=%d,Unack=%d,RRQuota=%d,RRUnack=%d",
1195         l2cb.controller_le_xmit_window, p_lcb->handle, p_lcb->link_xmit_quota,
1196         p_lcb->sent_not_acked, l2cb.ble_round_robin_quota,
1197         l2cb.ble_round_robin_unacked);
1198   } else {
1199     L2CAP_TRACE_DEBUG(
1200         "TotalWin=%d,Hndl=0x%x,Quota=%d,Unack=%d,RRQuota=%d,RRUnack=%d",
1201         l2cb.controller_xmit_window, p_lcb->handle, p_lcb->link_xmit_quota,
1202         p_lcb->sent_not_acked, l2cb.round_robin_quota,
1203         l2cb.round_robin_unacked);
1204   }
1205 #endif
1206 
1207   if (p_cbi) l2cu_tx_complete(p_cbi);
1208 
1209   return true;
1210 }
1211 
1212 /*******************************************************************************
1213  *
1214  * Function         l2c_link_process_num_completed_pkts
1215  *
1216  * Description      This function is called when a "number-of-completed-packets"
1217  *                  event is received from the controller. It updates all the
1218  *                  LCB transmit counts.
1219  *
1220  * Returns          void
1221  *
1222  ******************************************************************************/
l2c_link_process_num_completed_pkts(uint8_t * p,uint8_t evt_len)1223 void l2c_link_process_num_completed_pkts(uint8_t* p, uint8_t evt_len) {
1224   uint8_t num_handles, xx;
1225   uint16_t handle;
1226   uint16_t num_sent;
1227   tL2C_LCB* p_lcb;
1228 
1229   if (evt_len > 0) {
1230     STREAM_TO_UINT8(num_handles, p);
1231   } else {
1232     num_handles = 0;
1233   }
1234 
1235   if (num_handles > evt_len / (2 * sizeof(uint16_t))) {
1236     android_errorWriteLog(0x534e4554, "141617601");
1237     num_handles = evt_len / (2 * sizeof(uint16_t));
1238   }
1239 
1240   for (xx = 0; xx < num_handles; xx++) {
1241     STREAM_TO_UINT16(handle, p);
1242     /* Extract the handle */
1243     handle = HCID_GET_HANDLE(handle);
1244     STREAM_TO_UINT16(num_sent, p);
1245 
1246     p_lcb = l2cu_find_lcb_by_handle(handle);
1247 
1248     /* Callback for number of completed packet event    */
1249     /* Originally designed for [3DSG]                   */
1250     if ((p_lcb != NULL) && (p_lcb->p_nocp_cb)) {
1251       L2CAP_TRACE_DEBUG("L2CAP - calling NoCP callback");
1252       (*p_lcb->p_nocp_cb)(p_lcb->remote_bd_addr);
1253     }
1254 
1255     if (p_lcb) {
1256       if (p_lcb && (p_lcb->transport == BT_TRANSPORT_LE))
1257         l2cb.controller_le_xmit_window += num_sent;
1258       else {
1259         /* Maintain the total window to the controller */
1260         l2cb.controller_xmit_window += num_sent;
1261       }
1262       /* If doing round-robin, adjust communal counts */
1263       if (p_lcb->link_xmit_quota == 0) {
1264         if (p_lcb->transport == BT_TRANSPORT_LE) {
1265           /* Don't go negative */
1266           if (l2cb.ble_round_robin_unacked > num_sent)
1267             l2cb.ble_round_robin_unacked -= num_sent;
1268           else
1269             l2cb.ble_round_robin_unacked = 0;
1270         } else {
1271           /* Don't go negative */
1272           if (l2cb.round_robin_unacked > num_sent)
1273             l2cb.round_robin_unacked -= num_sent;
1274           else
1275             l2cb.round_robin_unacked = 0;
1276         }
1277       }
1278 
1279       /* Don't go negative */
1280       if (p_lcb->sent_not_acked > num_sent)
1281         p_lcb->sent_not_acked -= num_sent;
1282       else
1283         p_lcb->sent_not_acked = 0;
1284 
1285       l2c_link_check_send_pkts(p_lcb, NULL, NULL);
1286 
1287       /* If we were doing round-robin for low priority links, check 'em */
1288       if ((p_lcb->acl_priority == L2CAP_PRIORITY_HIGH) &&
1289           (l2cb.check_round_robin) &&
1290           (l2cb.round_robin_unacked < l2cb.round_robin_quota)) {
1291         l2c_link_check_send_pkts(NULL, NULL, NULL);
1292       }
1293       if ((p_lcb->transport == BT_TRANSPORT_LE) &&
1294           (p_lcb->acl_priority == L2CAP_PRIORITY_HIGH) &&
1295           ((l2cb.ble_check_round_robin) &&
1296            (l2cb.ble_round_robin_unacked < l2cb.ble_round_robin_quota))) {
1297         l2c_link_check_send_pkts(NULL, NULL, NULL);
1298       }
1299     }
1300 
1301 #if (L2CAP_HCI_FLOW_CONTROL_DEBUG == TRUE)
1302     if (p_lcb) {
1303       if (p_lcb->transport == BT_TRANSPORT_LE) {
1304         L2CAP_TRACE_DEBUG(
1305             "TotalWin=%d,LinkUnack(0x%x)=%d,RRCheck=%d,RRUnack=%d",
1306             l2cb.controller_le_xmit_window, p_lcb->handle,
1307             p_lcb->sent_not_acked, l2cb.ble_check_round_robin,
1308             l2cb.ble_round_robin_unacked);
1309       } else {
1310         L2CAP_TRACE_DEBUG(
1311             "TotalWin=%d,LinkUnack(0x%x)=%d,RRCheck=%d,RRUnack=%d",
1312             l2cb.controller_xmit_window, p_lcb->handle, p_lcb->sent_not_acked,
1313             l2cb.check_round_robin, l2cb.round_robin_unacked);
1314       }
1315     } else {
1316       L2CAP_TRACE_DEBUG(
1317           "TotalWin=%d  LE_Win: %d, Handle=0x%x, RRCheck=%d, RRUnack=%d",
1318           l2cb.controller_xmit_window, l2cb.controller_le_xmit_window, handle,
1319           l2cb.ble_check_round_robin, l2cb.ble_round_robin_unacked);
1320     }
1321 #endif
1322   }
1323 }
1324 
1325 /*******************************************************************************
1326  *
1327  * Function         l2c_link_segments_xmitted
1328  *
1329  * Description      This function is called from the HCI Interface when an ACL
1330  *                  data packet segment is transmitted.
1331  *
1332  * Returns          void
1333  *
1334  ******************************************************************************/
l2c_link_segments_xmitted(BT_HDR * p_msg)1335 void l2c_link_segments_xmitted(BT_HDR* p_msg) {
1336   uint8_t* p = (uint8_t*)(p_msg + 1) + p_msg->offset;
1337   uint16_t handle;
1338   tL2C_LCB* p_lcb;
1339 
1340   /* Extract the handle */
1341   STREAM_TO_UINT16(handle, p);
1342   handle = HCID_GET_HANDLE(handle);
1343 
1344   /* Find the LCB based on the handle */
1345   p_lcb = l2cu_find_lcb_by_handle(handle);
1346   if (p_lcb == NULL) {
1347     L2CAP_TRACE_WARNING("L2CAP - rcvd segment complete, unknown handle: %d",
1348                         handle);
1349     osi_free(p_msg);
1350     return;
1351   }
1352 
1353   if (p_lcb->link_state == LST_CONNECTED) {
1354     /* Enqueue the buffer to the head of the transmit queue, and see */
1355     /* if we can transmit anything more.                             */
1356     list_prepend(p_lcb->link_xmit_data_q, p_msg);
1357 
1358     p_lcb->partial_segment_being_sent = false;
1359 
1360     l2c_link_check_send_pkts(p_lcb, NULL, NULL);
1361   } else
1362     osi_free(p_msg);
1363 }
1364