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 L2CAP API definitions
22  *
23  ******************************************************************************/
24 #ifndef L2C_API_H
25 #define L2C_API_H
26 
27 #include <vector>
28 #include <stdbool.h>
29 
30 #include "bt_target.h"
31 #include "hcidefs.h"
32 #include "l2cdefs.h"
33 #include "types/bt_transport.h"
34 #include "types/hci_role.h"
35 
36 /*****************************************************************************
37  *  Constants
38  ****************************************************************************/
39 
40 /* Define the minimum offset that L2CAP needs in a buffer. This is made up of
41  * HCI type(1), len(2), handle(2), L2CAP len(2) and CID(2) => 9
42  */
43 #define L2CAP_MIN_OFFSET 13 /* plus control(2), SDU length(2) */
44 
45 #define L2CAP_LCC_SDU_LENGTH 2
46 #define L2CAP_LCC_OFFSET \
47   (L2CAP_MIN_OFFSET + L2CAP_LCC_SDU_LENGTH) /* plus SDU length(2) */
48 
49 #define L2CAP_FCS_LENGTH 2
50 
51 /* result code for L2CA_DataWrite() */
52 #define L2CAP_DW_FAILED false
53 #define L2CAP_DW_SUCCESS true
54 #define L2CAP_DW_CONGESTED 2
55 
56 /* Values for priority parameter to L2CA_SetAclPriority */
57 typedef enum : uint8_t {
58   L2CAP_PRIORITY_NORMAL = 0,
59   L2CAP_PRIORITY_HIGH = 1,
60 } tL2CAP_PRIORITY;
61 
62 /* Values for priority parameter to L2CA_SetTxPriority */
63 #define L2CAP_CHNL_PRIORITY_HIGH 0
64 #define L2CAP_CHNL_PRIORITY_LOW 2
65 
66 typedef uint8_t tL2CAP_CHNL_PRIORITY;
67 
68 /* Values for Tx/Rx data rate parameter to L2CA_SetChnlDataRate */
69 #define L2CAP_CHNL_DATA_RATE_LOW 1
70 
71 typedef uint8_t tL2CAP_CHNL_DATA_RATE;
72 
73 /* Data Packet Flags  (bits 2-15 are reserved) */
74 /* layer specific 14-15 bits are used for FCR SAR */
75 #define L2CAP_FLUSHABLE_MASK 0x0003
76 #define L2CAP_FLUSHABLE_CH_BASED 0x0000
77 #define L2CAP_FLUSHABLE_PKT 0x0001
78 #define L2CAP_NON_FLUSHABLE_PKT 0x0002
79 
80 /* L2CA_FlushChannel num_to_flush definitions */
81 #define L2CAP_FLUSH_CHANS_ALL 0xffff
82 #define L2CAP_FLUSH_CHANS_GET 0x0000
83 
84 /* Values for 'allowed_modes' field passed in structure tL2CAP_ERTM_INFO
85  */
86 #define L2CAP_FCR_CHAN_OPT_BASIC (1 << L2CAP_FCR_BASIC_MODE)
87 #define L2CAP_FCR_CHAN_OPT_ERTM (1 << L2CAP_FCR_ERTM_MODE)
88 
89 #define L2CAP_FCR_CHAN_OPT_ALL_MASK \
90   (L2CAP_FCR_CHAN_OPT_BASIC | L2CAP_FCR_CHAN_OPT_ERTM)
91 
92 /* Validity check for PSM.  PSM values must be odd.  Also, all PSM values must
93  * be assigned such that the least significant bit of the most sigificant
94  * octet equals zero.
95  */
96 #define L2C_INVALID_PSM(psm) (((psm)&0x0101) != 0x0001)
97 #define L2C_IS_VALID_PSM(psm) (((psm)&0x0101) == 0x0001)
98 #define L2C_IS_VALID_LE_PSM(psm) (((psm) > 0x0000) && ((psm) < 0x0100))
99 
100 /*****************************************************************************
101  *  Type Definitions
102  ****************************************************************************/
103 
104 typedef struct {
105 #define L2CAP_FCR_BASIC_MODE 0x00
106 #define L2CAP_FCR_ERTM_MODE 0x03
107 #define L2CAP_FCR_LE_COC_MODE 0x05
108 
109   uint8_t mode;
110 
111   uint8_t tx_win_sz;
112   uint8_t max_transmit;
113   uint16_t rtrans_tout;
114   uint16_t mon_tout;
115   uint16_t mps;
116 } tL2CAP_FCR_OPTS;
117 
118 /* default options for ERTM mode */
119 constexpr tL2CAP_FCR_OPTS kDefaultErtmOptions = {
120     L2CAP_FCR_ERTM_MODE,
121     10,    /* Tx window size */
122     20,    /* Maximum transmissions before disconnecting */
123     2000,  /* Retransmission timeout (2 secs) */
124     12000, /* Monitor timeout (12 secs) */
125     1010   /* MPS segment size */
126 };
127 
128 typedef struct {
129   uint8_t qos_flags;          /* TBD */
130   uint8_t service_type;       /* see below */
131   uint32_t token_rate;        /* bytes/second */
132   uint32_t token_bucket_size; /* bytes */
133   uint32_t peak_bandwidth;    /* bytes/second */
134   uint32_t latency;           /* microseconds */
135   uint32_t delay_variation;   /* microseconds */
136 } FLOW_SPEC;
137 
138 /* Values for service_type */
139 #define SVC_TYPE_BEST_EFFORT 1
140 #define SVC_TYPE_GUARANTEED 2
141 
142 /* Define a structure to hold the configuration parameters. Since the
143  * parameters are optional, for each parameter there is a boolean to
144  * use to signify its presence or absence.
145  */
146 typedef struct {
147   uint16_t result; /* Only used in confirm messages */
148   bool mtu_present;
149   uint16_t mtu;
150   bool qos_present;
151   FLOW_SPEC qos;
152   bool flush_to_present;
153   uint16_t flush_to;
154   bool fcr_present;
155   tL2CAP_FCR_OPTS fcr;
156   bool fcs_present; /* Optionally bypasses FCS checks */
157   uint8_t fcs;      /* '0' if desire is to bypass FCS, otherwise '1' */
158   bool ext_flow_spec_present;
159   tHCI_EXT_FLOW_SPEC ext_flow_spec;
160   uint16_t flags; /* bit 0: 0-no continuation, 1-continuation */
161 } tL2CAP_CFG_INFO;
162 
163 /* LE credit based L2CAP connection parameters */
164 constexpr uint16_t L2CAP_LE_MIN_MTU = 23;  // Minimum SDU size
165 constexpr uint16_t L2CAP_LE_MIN_MPS = 23;
166 constexpr uint16_t L2CAP_LE_MAX_MPS = 65533;
167 constexpr uint16_t L2CAP_LE_CREDIT_MAX = 65535;
168 
169 // This is initial amout of credits we send, and amount to which we increase
170 // credits once they fall below threshold
171 constexpr uint16_t L2CAP_LE_CREDIT_DEFAULT = 0xffff;
172 
173 // If credit count on remote fall below this value, we send back credits to
174 // reach default value.
175 constexpr uint16_t L2CAP_LE_CREDIT_THRESHOLD = 0x0040;
176 
177 static_assert(L2CAP_LE_CREDIT_THRESHOLD < L2CAP_LE_CREDIT_DEFAULT,
178               "Threshold must be smaller than default credits");
179 
180 /* Define a structure to hold the configuration parameter for LE L2CAP
181  * connection oriented channels.
182  */
183 struct tL2CAP_LE_CFG_INFO {
184   uint16_t result; /* Only used in confirm messages */
185   uint16_t mtu = 100;
186   uint16_t mps = 100;
187   uint16_t credits = L2CAP_LE_CREDIT_DEFAULT;
188 };
189 
190 /*********************************
191  *  Callback Functions Prototypes
192  *********************************/
193 
194 /* Connection indication callback prototype. Parameters are
195  *              BD Address of remote
196  *              Local CID assigned to the connection
197  *              PSM that the remote wants to connect to
198  *              Identifier that the remote sent
199  */
200 typedef void(tL2CA_CONNECT_IND_CB)(const RawAddress&, uint16_t, uint16_t,
201                                    uint8_t);
202 
203 /* Connection confirmation callback prototype. Parameters are
204  *              Local CID
205  *              Result - 0 = connected
206  *              If there is an error, tL2CA_ERROR_CB is invoked
207  */
208 typedef void(tL2CA_CONNECT_CFM_CB)(uint16_t, uint16_t);
209 
210 /* Configuration indication callback prototype. Parameters are
211  *              Local CID assigned to the connection
212  *              Pointer to configuration info
213  */
214 typedef void(tL2CA_CONFIG_IND_CB)(uint16_t, tL2CAP_CFG_INFO*);
215 
216 constexpr uint16_t L2CAP_INITIATOR_LOCAL = 1;
217 constexpr uint16_t L2CAP_INITIATOR_REMOTE = 0;
218 /* Configuration confirm callback prototype. Parameters are
219  *              Local CID assigned to the connection
220  *              Initiator (1 for local, 0 for remote)
221  *              Initial config from remote
222  * If there is an error, tL2CA_ERROR_CB is invoked
223  */
224 typedef void(tL2CA_CONFIG_CFM_CB)(uint16_t, uint16_t, tL2CAP_CFG_INFO*);
225 
226 /* Disconnect indication callback prototype. Parameters are
227  *              Local CID
228  *              Boolean whether upper layer should ack this
229  */
230 typedef void(tL2CA_DISCONNECT_IND_CB)(uint16_t, bool);
231 
232 /* Disconnect confirm callback prototype. Parameters are
233  *              Local CID
234  *              Result
235  */
236 typedef void(tL2CA_DATA_IND_CB)(uint16_t, BT_HDR*);
237 
238 /* Congestion status callback protype. This callback is optional. If
239  * an application tries to send data when the transmit queue is full,
240  * the data will anyways be dropped. The parameter is:
241  *              Local CID
242  *              true if congested, false if uncongested
243  */
244 typedef void(tL2CA_CONGESTION_STATUS_CB)(uint16_t, bool);
245 
246 /* Transmit complete callback protype. This callback is optional. If
247  * set, L2CAP will call it when packets are sent or flushed. If the
248  * count is 0xFFFF, it means all packets are sent for that CID (eRTM
249  * mode only). The parameters are:
250  *              Local CID
251  *              Number of SDUs sent or dropped
252  */
253 typedef void(tL2CA_TX_COMPLETE_CB)(uint16_t, uint16_t);
254 
255 /*
256  * Notify the user when the remote send error result on ConnectRsp or ConfigRsp
257  * The parameters are:
258  *              Local CID
259  *              Error type (L2CAP_CONN_OTHER_ERROR for ConnectRsp,
260  *                          L2CAP_CFG_FAILED_NO_REASON for ConfigRsp)
261  */
262 typedef void(tL2CA_ERROR_CB)(uint16_t, uint16_t);
263 
264 /* Create credit based connection request callback prototype. Parameters are
265  *              BD Address of remote
266  *              Vector of allocated local cids to accept
267  *              PSM
268  *              Peer MTU
269  *              Identifier that the remote sent
270  */
271 typedef void(tL2CA_CREDIT_BASED_CONNECT_IND_CB)(const RawAddress& bdaddr,
272                                                 std::vector<uint16_t>& lcids,
273                                                 uint16_t psm, uint16_t peer_mtu,
274                                                 uint8_t identifier);
275 
276 /* Credit based connection confirmation callback prototype. Parameters are
277  *              BD Address of remote
278  *              Connected Local CIDs
279  *              Peer MTU
280  *              Result - 0 = connected, non-zero means CID is not connected
281  */
282 typedef void(tL2CA_CREDIT_BASED_CONNECT_CFM_CB)(const RawAddress& bdaddr,
283                                                 uint16_t lcid,
284                                                 uint16_t peer_mtu,
285                                                 uint16_t result);
286 
287 /* Credit based reconfiguration confirm callback prototype. Parameters are
288  *              BD Address of remote
289  *              Local CID assigned to the connection
290  *              Flag indicating if this is local or peer configuration
291  *              Pointer to configuration info
292  */
293 typedef void(tL2CA_CREDIT_BASED_RECONFIG_COMPLETED_CB)(
294     const RawAddress& bdaddr, uint16_t lcid, bool is_local_cfg,
295     tL2CAP_LE_CFG_INFO* p_cfg);
296 
297 /* Define the structure that applications use to register with
298  * L2CAP. This structure includes callback functions. All functions
299  * MUST be provided, with the exception of the "connect pending"
300  * callback and "congestion status" callback.
301  */
302 typedef struct {
303   tL2CA_CONNECT_IND_CB* pL2CA_ConnectInd_Cb;
304   tL2CA_CONNECT_CFM_CB* pL2CA_ConnectCfm_Cb;
305   tL2CA_CONFIG_IND_CB* pL2CA_ConfigInd_Cb;
306   tL2CA_CONFIG_CFM_CB* pL2CA_ConfigCfm_Cb;
307   tL2CA_DISCONNECT_IND_CB* pL2CA_DisconnectInd_Cb;
308   tL2CA_DATA_IND_CB* pL2CA_DataInd_Cb;
309   tL2CA_CONGESTION_STATUS_CB* pL2CA_CongestionStatus_Cb;
310   tL2CA_TX_COMPLETE_CB* pL2CA_TxComplete_Cb;
311   tL2CA_ERROR_CB* pL2CA_Error_Cb;
312   tL2CA_CREDIT_BASED_CONNECT_IND_CB* pL2CA_CreditBasedConnectInd_Cb;
313   tL2CA_CREDIT_BASED_CONNECT_CFM_CB* pL2CA_CreditBasedConnectCfm_Cb;
314   tL2CA_CREDIT_BASED_RECONFIG_COMPLETED_CB*
315       pL2CA_CreditBasedReconfigCompleted_Cb;
316 } tL2CAP_APPL_INFO;
317 
318 /* Define the structure that applications use to create or accept
319  * connections with enhanced retransmission mode.
320  */
321 typedef struct {
322   uint8_t preferred_mode;
323 } tL2CAP_ERTM_INFO;
324 
325 /**
326  * Stack management declarations
327  */
328 void l2c_init();
329 void l2c_free();
330 
331 /*****************************************************************************
332  *  External Function Declarations
333  ****************************************************************************/
334 
335 // Also does security for you
336 uint16_t L2CA_Register2(uint16_t psm, const tL2CAP_APPL_INFO& p_cb_info,
337                         bool enable_snoop, tL2CAP_ERTM_INFO* p_ertm_info,
338                         uint16_t my_mtu, uint16_t required_remote_mtu,
339                         uint16_t sec_level);
340 
341 /*******************************************************************************
342  *
343  * Function         L2CA_Register
344  *
345  * Description      Other layers call this function to register for L2CAP
346  *                  services.
347  *
348  * Returns          PSM to use or zero if error. Typically, the PSM returned
349  *                  is the same as was passed in, but for an outgoing-only
350  *                  connection to a dynamic PSM, a "virtual" PSM is returned
351  *                  and should be used in the calls to L2CA_ConnectReq() and
352  *                  BTM_SetSecurityLevel().
353  *
354  ******************************************************************************/
355 extern uint16_t L2CA_Register(uint16_t psm, const tL2CAP_APPL_INFO& p_cb_info,
356                               bool enable_snoop, tL2CAP_ERTM_INFO* p_ertm_info,
357                               uint16_t my_mtu, uint16_t required_remote_mtu,
358                               uint16_t sec_level);
359 
360 /*******************************************************************************
361  *
362  * Function         L2CA_Deregister
363  *
364  * Description      Other layers call this function to deregister for L2CAP
365  *                  services.
366  *
367  * Returns          void
368  *
369  ******************************************************************************/
370 extern void L2CA_Deregister(uint16_t psm);
371 
372 /*******************************************************************************
373  *
374  * Function         L2CA_AllocateLePSM
375  *
376  * Description      Other layers call this function to find an unused LE PSM for
377  *                  L2CAP services.
378  *
379  * Returns          LE_PSM to use if success. Otherwise returns 0.
380  *
381  ******************************************************************************/
382 extern uint16_t L2CA_AllocateLePSM(void);
383 
384 /*******************************************************************************
385  *
386  * Function         L2CA_FreeLePSM
387  *
388  * Description      Free an assigned LE PSM.
389  *
390  * Returns          void
391  *
392  ******************************************************************************/
393 extern void L2CA_FreeLePSM(uint16_t psm);
394 
395 extern uint16_t L2CA_ConnectReq2(uint16_t psm, const RawAddress& p_bd_addr,
396                                  uint16_t sec_level);
397 /*******************************************************************************
398  *
399  * Function         L2CA_ConnectReq
400  *
401  * Description      Higher layers call this function to create an L2CAP
402  *                  connection.
403  *                  Note that the connection is not established at this time,
404  *                  but connection establishment gets started. The callback
405  *                  will be invoked when connection establishes or fails.
406  *
407  * Returns          the CID of the connection, or 0 if it failed to start
408  *
409  ******************************************************************************/
410 extern uint16_t L2CA_ConnectReq(uint16_t psm, const RawAddress& p_bd_addr);
411 
412 /*******************************************************************************
413  *
414  * Function         L2CA_RegisterLECoc
415  *
416  * Description      Other layers call this function to register for L2CAP
417  *                  Connection Oriented Channel.
418  *
419  * Returns          PSM to use or zero if error. Typically, the PSM returned
420  *                  is the same as was passed in, but for an outgoing-only
421  *                  connection to a dynamic PSM, a "virtual" PSM is returned
422  *                  and should be used in the calls to L2CA_ConnectLECocReq()
423  *                  and BTM_SetSecurityLevel().
424  *
425  ******************************************************************************/
426 extern uint16_t L2CA_RegisterLECoc(uint16_t psm,
427                                    const tL2CAP_APPL_INFO& p_cb_info,
428                                    uint16_t sec_level, tL2CAP_LE_CFG_INFO cfg);
429 
430 /*******************************************************************************
431  *
432  * Function         L2CA_DeregisterLECoc
433  *
434  * Description      Other layers call this function to deregister for L2CAP
435  *                  Connection Oriented Channel.
436  *
437  * Returns          void
438  *
439  ******************************************************************************/
440 extern void L2CA_DeregisterLECoc(uint16_t psm);
441 
442 /*******************************************************************************
443  *
444  * Function         L2CA_ConnectLECocReq
445  *
446  * Description      Higher layers call this function to create an L2CAP LE COC.
447  *                  Note that the connection is not established at this time,
448  *                  but connection establishment gets started. The callback
449  *                  will be invoked when connection establishes or fails.
450  *
451  * Returns          the CID of the connection, or 0 if it failed to start
452  *
453  ******************************************************************************/
454 extern uint16_t L2CA_ConnectLECocReq(uint16_t psm, const RawAddress& p_bd_addr,
455                                      tL2CAP_LE_CFG_INFO* p_cfg,
456                                      uint16_t sec_level);
457 
458 /*******************************************************************************
459  *
460  *  Function         L2CA_GetPeerLECocConfig
461  *
462  *  Description      Get peers configuration for LE Connection Oriented Channel.
463  *
464  *  Return value:    true if peer is connected
465  *
466  ******************************************************************************/
467 extern bool L2CA_GetPeerLECocConfig(uint16_t lcid,
468                                     tL2CAP_LE_CFG_INFO* peer_cfg);
469 
470 /*******************************************************************************
471  *
472  *  Function         L2CA_ReconfigCreditBasedConnsReq
473  *
474  *  Description      Start reconfigure procedure on Connection Oriented Channel.
475  *
476  *  Return value:    true if peer is connected
477  *
478  ******************************************************************************/
479 
480 extern bool L2CA_ReconfigCreditBasedConnsReq(const RawAddress& bd_addr,
481                                              std::vector<uint16_t>& lcids,
482                                              tL2CAP_LE_CFG_INFO* p_cfg);
483 
484 /*******************************************************************************
485  *
486  *  Function         L2CA_ConnectCreditBasedReq
487  *
488  *  Description      With this function L2CAP will initiate setup of up to 5 credit
489  *                   based connections for given psm using provided configuration.
490  *                   L2CAP will notify user on the connection result, by calling
491  *                   pL2CA_CreditBasedConnectCfm_Cb for each cid with a result.
492  *
493  *  Return value: vector of allocated local cids for the connection
494  *
495  ******************************************************************************/
496 
497 extern std::vector<uint16_t> L2CA_ConnectCreditBasedReq(
498     uint16_t psm, const RawAddress& p_bd_addr, tL2CAP_LE_CFG_INFO* p_cfg);
499 
500 /*******************************************************************************
501  *
502  *  Function         L2CA_ConnectCreditBasedRsp
503  *
504  *  Description      Response for the pL2CA_CreditBasedConnectInd_Cb which is the
505  *                   indication for peer requesting credit based connection.
506  *
507  *  Return value: true if peer is connected
508  *
509  ******************************************************************************/
510 
511 extern bool L2CA_ConnectCreditBasedRsp(const RawAddress& p_bd_addr, uint8_t id,
512                                        std::vector<uint16_t>& accepted_lcids,
513                                        uint16_t result,
514                                        tL2CAP_LE_CFG_INFO* p_cfg);
515 /*******************************************************************************
516  *
517  * Function         L2CA_DisconnectReq
518  *
519  * Description      Higher layers call this function to disconnect a channel.
520  *
521  * Returns          true if disconnect sent, else false
522  *
523  ******************************************************************************/
524 extern bool L2CA_DisconnectReq(uint16_t cid);
525 
526 extern bool L2CA_DisconnectLECocReq(uint16_t cid);
527 
528 /*******************************************************************************
529  *
530  * Function         L2CA_DataWrite
531  *
532  * Description      Higher layers call this function to write data.
533  *
534  * Returns          L2CAP_DW_SUCCESS, if data accepted, else false
535  *                  L2CAP_DW_CONGESTED, if data accepted and the channel is
536  *                                      congested
537  *                  L2CAP_DW_FAILED, if error
538  *
539  ******************************************************************************/
540 extern uint8_t L2CA_DataWrite(uint16_t cid, BT_HDR* p_data);
541 
542 extern uint8_t L2CA_LECocDataWrite(uint16_t cid, BT_HDR* p_data);
543 
544 // Given a local channel identifier, |lcid|, this function returns the bound
545 // remote channel identifier, |rcid|. If
546 // |lcid| is not known or is invalid, this function returns false and does not
547 // modify the value pointed at by |rcid|. |rcid| may be NULL.
548 bool L2CA_GetRemoteCid(uint16_t lcid, uint16_t* rcid);
549 
550 /*******************************************************************************
551  *
552  * Function         L2CA_SetIdleTimeoutByBdAddr
553  *
554  * Description      Higher layers call this function to set the idle timeout for
555  *                  a connection. The "idle timeout" is the amount of time that
556  *                  a connection can remain up with no L2CAP channels on it.
557  *                  A timeout of zero means that the connection will be torn
558  *                  down immediately when the last channel is removed.
559  *                  A timeout of 0xFFFF means no timeout. Values are in seconds.
560  *                  A bd_addr is the remote BD address. If bd_addr =
561  *                  RawAddress::kAny, then the idle timeouts for all active
562  *                  l2cap links will be changed.
563  *
564  * Returns          true if command succeeded, false if failed
565  *
566  * NOTE             This timeout applies to all logical channels active on the
567  *                  ACL link.
568  ******************************************************************************/
569 extern bool L2CA_SetIdleTimeoutByBdAddr(const RawAddress& bd_addr,
570                                         uint16_t timeout,
571                                         tBT_TRANSPORT transport);
572 
573 /*******************************************************************************
574  *
575  * Function         L2CA_SetTraceLevel
576  *
577  * Description      This function sets the trace level for L2CAP. If called with
578  *                  a value of 0xFF, it simply reads the current trace level.
579  *
580  * Returns          the new (current) trace level
581  *
582  ******************************************************************************/
583 extern uint8_t L2CA_SetTraceLevel(uint8_t trace_level);
584 
585 /*******************************************************************************
586  *
587  * Function     L2CA_FlushChannel
588  *
589  * Description  This function flushes none, some or all buffers queued up
590  *              for xmission for a particular CID. If called with
591  *              L2CAP_FLUSH_CHANS_GET (0), it simply returns the number
592  *              of buffers queued for that CID L2CAP_FLUSH_CHANS_ALL (0xffff)
593  *              flushes all buffers.  All other values specifies the maximum
594  *              buffers to flush.
595  *
596  * Returns      Number of buffers left queued for that CID
597  *
598  ******************************************************************************/
599 extern uint16_t L2CA_FlushChannel(uint16_t lcid, uint16_t num_to_flush);
600 
601 /*******************************************************************************
602  *
603  * Function         L2CA_SetAclPriority
604  *
605  * Description      Sets the transmission priority for an ACL channel.
606  *                  (For initial implementation only two values are valid.
607  *                  L2CAP_PRIORITY_NORMAL and L2CAP_PRIORITY_HIGH).
608  *
609  * Returns          true if a valid channel, else false
610  *
611  ******************************************************************************/
612 extern bool L2CA_SetAclPriority(const RawAddress& bd_addr,
613                                 tL2CAP_PRIORITY priority);
614 
615 /*******************************************************************************
616  *
617  * Function         L2CA_SetTxPriority
618  *
619  * Description      Sets the transmission priority for a channel. (FCR Mode)
620  *
621  * Returns          true if a valid channel, else false
622  *
623  ******************************************************************************/
624 extern bool L2CA_SetTxPriority(uint16_t cid, tL2CAP_CHNL_PRIORITY priority);
625 
626 /*******************************************************************************
627  *
628  * Function         L2CA_SetChnlFlushability
629  *
630  * Description      Higher layers call this function to set a channels
631  *                  flushability flags
632  *
633  * Returns          true if CID found, else false
634  *
635  ******************************************************************************/
636 extern bool L2CA_SetChnlFlushability(uint16_t cid, bool is_flushable);
637 
638 /*******************************************************************************
639  *
640  *  Function         L2CA_GetPeerFeatures
641  *
642  *  Description      Get a peers features and fixed channel map
643  *
644  *  Parameters:      BD address of the peer
645  *                   Pointers to features and channel mask storage area
646  *
647  *  Return value:    true if peer is connected
648  *
649  ******************************************************************************/
650 extern bool L2CA_GetPeerFeatures(const RawAddress& bd_addr,
651                                  uint32_t* p_ext_feat, uint8_t* p_chnl_mask);
652 
653 /*******************************************************************************
654  *
655  *                      Fixed Channel callback prototypes
656  *
657  ******************************************************************************/
658 
659 /* Fixed channel connected and disconnected. Parameters are
660  *      channel
661  *      BD Address of remote
662  *      true if channel is connected, false if disconnected
663  *      Reason for connection failure
664  *      transport : physical transport, BR/EDR or LE
665  */
666 typedef void(tL2CA_FIXED_CHNL_CB)(uint16_t, const RawAddress&, bool, uint16_t,
667                                   tBT_TRANSPORT);
668 
669 /* Signalling data received. Parameters are
670  *      channel
671  *      BD Address of remote
672  *      Pointer to buffer with data
673  */
674 typedef void(tL2CA_FIXED_DATA_CB)(uint16_t, const RawAddress&, BT_HDR*);
675 
676 /* Congestion status callback protype. This callback is optional. If
677  * an application tries to send data when the transmit queue is full,
678  * the data will anyways be dropped. The parameter is:
679  *      remote BD_ADDR
680  *      true if congested, false if uncongested
681  */
682 typedef void(tL2CA_FIXED_CONGESTION_STATUS_CB)(const RawAddress&, bool);
683 
684 /* Fixed channel registration info (the callback addresses and channel config)
685  */
686 typedef struct {
687   tL2CA_FIXED_CHNL_CB* pL2CA_FixedConn_Cb;
688   tL2CA_FIXED_DATA_CB* pL2CA_FixedData_Cb;
689   tL2CA_FIXED_CONGESTION_STATUS_CB* pL2CA_FixedCong_Cb;
690 
691   uint16_t default_idle_tout;
692 } tL2CAP_FIXED_CHNL_REG;
693 
694 /*******************************************************************************
695  *
696  *  Function        L2CA_RegisterFixedChannel
697  *
698  *  Description     Register a fixed channel.
699  *
700  *  Parameters:     Fixed Channel #
701  *                  Channel Callbacks and config
702  *
703  *  Return value:   true if registered OK
704  *
705  ******************************************************************************/
706 extern bool L2CA_RegisterFixedChannel(uint16_t fixed_cid,
707                                       tL2CAP_FIXED_CHNL_REG* p_freg);
708 
709 /*******************************************************************************
710  *
711  *  Function        L2CA_ConnectFixedChnl
712  *
713  *  Description     Connect an fixed signalling channel to a remote device.
714  *
715  *  Parameters:     Fixed CID
716  *                  BD Address of remote
717  *
718  *  Return value:   true if connection started
719  *
720  ******************************************************************************/
721 extern bool L2CA_ConnectFixedChnl(uint16_t fixed_cid,
722                                   const RawAddress& bd_addr);
723 
724 /*******************************************************************************
725  *
726  *  Function        L2CA_SendFixedChnlData
727  *
728  *  Description     Write data on a fixed signalling channel.
729  *
730  *  Parameters:     Fixed CID
731  *                  BD Address of remote
732  *                  Pointer to buffer of type BT_HDR
733  *
734  * Return value     L2CAP_DW_SUCCESS, if data accepted
735  *                  L2CAP_DW_FAILED,  if error
736  *
737  ******************************************************************************/
738 extern uint16_t L2CA_SendFixedChnlData(uint16_t fixed_cid,
739                                        const RawAddress& rem_bda,
740                                        BT_HDR* p_buf);
741 
742 /*******************************************************************************
743  *
744  *  Function        L2CA_RemoveFixedChnl
745  *
746  *  Description     Remove a fixed channel to a remote device.
747  *
748  *  Parameters:     Fixed CID
749  *                  BD Address of remote
750  *                  Idle timeout to use (or 0xFFFF if don't care)
751  *
752  *  Return value:   true if channel removed
753  *
754  ******************************************************************************/
755 extern bool L2CA_RemoveFixedChnl(uint16_t fixed_cid, const RawAddress& rem_bda);
756 
757 /*******************************************************************************
758  *
759  * Function         L2CA_SetLeGattTimeout
760  *
761  * Description      Higher layers call this function to set the idle timeout for
762  *                  a fixed channel. The "idle timeout" is the amount of time
763  *                  that a connection can remain up with no L2CAP channels on
764  *                  it. A timeout of zero means that the connection will be torn
765  *                  down immediately when the last channel is removed.
766  *                  A timeout of 0xFFFF means no timeout. Values are in seconds.
767  *                  A bd_addr is the remote BD address. If bd_addr =
768  *                  RawAddress::kAny, then the idle timeouts for all active
769  *                  l2cap links will be changed.
770  *
771  * Returns          true if command succeeded, false if failed
772  *
773  ******************************************************************************/
774 extern bool L2CA_SetLeGattTimeout(const RawAddress& rem_bda,
775                                   uint16_t idle_tout);
776 
777 extern bool L2CA_UpdateBleConnParams(const RawAddress& rem_bda,
778                                      uint16_t min_int, uint16_t max_int,
779                                      uint16_t latency, uint16_t timeout,
780                                      uint16_t min_ce_len, uint16_t max_ce_len);
781 
782 /*******************************************************************************
783  *
784  *  Function        L2CA_EnableUpdateBleConnParams
785  *
786  *  Description     Update BLE connection parameters.
787  *
788  *  Parameters:     BD Address of remote
789  *                  enable flag
790  *
791  *  Return value:   true if update started
792  *
793  ******************************************************************************/
794 extern bool L2CA_EnableUpdateBleConnParams(const RawAddress& rem_bda,
795                                            bool enable);
796 
797 /*******************************************************************************
798  *
799  * Function         L2CA_GetBleConnRole
800  *
801  * Description      This function returns the connection role.
802  *
803  * Returns          link role.
804  *
805  ******************************************************************************/
806 extern tHCI_ROLE L2CA_GetBleConnRole(const RawAddress& bd_addr);
807 
808 extern void L2CA_AdjustConnectionIntervals(uint16_t* min_interval,
809                                            uint16_t* max_interval,
810                                            uint16_t floor_interval);
811 
812 /**
813  * Check whether an ACL or LE link to the remote device is established
814  */
815 extern bool L2CA_IsLinkEstablished(const RawAddress& bd_addr,
816                                    tBT_TRANSPORT transport);
817 
818 #endif /* L2C_API_H */
819