xref: /btstack/src/classic/rfcomm.h (revision f0e9886bf1825249aaea7e15f4fe6fb8d065bffb)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 /**
39  * @title RFCOMM
40  *
41  */
42 
43 #ifndef RFCOMM_H
44 #define RFCOMM_H
45 
46 #include "btstack_util.h"
47 
48 #include <stdint.h>
49 #include "btstack_run_loop.h"
50 #include "gap.h"
51 #include "l2cap.h"
52 
53 #if defined __cplusplus
54 extern "C" {
55 #endif
56 
57 #define UNLIMITED_INCOMING_CREDITS 0xff
58 
59 #define RFCOMM_TEST_DATA_MAX_LEN 4
60 
61 #define RFCOMM_RLS_STATUS_INVALID 0xff
62 
63 
64 // private structs
65 typedef enum {
66 	RFCOMM_MULTIPLEXER_CLOSED = 1,
67 	RFCOMM_MULTIPLEXER_W4_CONNECT,  // outgoing
68 	RFCOMM_MULTIPLEXER_SEND_SABM_0,     //    "
69 	RFCOMM_MULTIPLEXER_W4_UA_0,     //    "
70 	RFCOMM_MULTIPLEXER_W4_SABM_0,   // incoming
71     RFCOMM_MULTIPLEXER_SEND_UA_0,
72 	RFCOMM_MULTIPLEXER_OPEN,
73     RFCOMM_MULTIPLEXER_SEND_UA_0_AND_DISC,
74     RFCOMM_MULTIPLEXER_SHUTTING_DOWN,
75 } RFCOMM_MULTIPLEXER_STATE;
76 
77 typedef enum {
78     MULT_EV_READY_TO_SEND = 1,
79 } RFCOMM_MULTIPLEXER_EVENT;
80 
81 typedef enum {
82 	RFCOMM_CHANNEL_CLOSED = 1,
83 	RFCOMM_CHANNEL_W4_MULTIPLEXER,
84 	RFCOMM_CHANNEL_SEND_UIH_PN,
85     RFCOMM_CHANNEL_W4_PN_RSP,
86 	RFCOMM_CHANNEL_SEND_SABM_W4_UA,
87 	RFCOMM_CHANNEL_W4_UA,
88     RFCOMM_CHANNEL_INCOMING_SETUP,
89     RFCOMM_CHANNEL_DLC_SETUP,
90 	RFCOMM_CHANNEL_OPEN,
91     RFCOMM_CHANNEL_SEND_UA_AFTER_DISC,
92     RFCOMM_CHANNEL_SEND_DISC,
93     RFCOMM_CHANNEL_W4_UA_AFTER_DISC,
94     RFCOMM_CHANNEL_SEND_DM,
95     RFCOMM_CHANNEL_EMIT_OPEN_FAILED_AND_DISCARD,
96 } RFCOMM_CHANNEL_STATE;
97 
98 typedef enum {
99     RFCOMM_CHANNEL_STATE_VAR_NONE            = 0,
100     RFCOMM_CHANNEL_STATE_VAR_CLIENT_ACCEPTED = 1 << 0,
101     RFCOMM_CHANNEL_STATE_VAR_RCVD_PN         = 1 << 1,
102     RFCOMM_CHANNEL_STATE_VAR_RCVD_RPN        = 1 << 2,
103     RFCOMM_CHANNEL_STATE_VAR_RCVD_SABM       = 1 << 3,
104 
105     RFCOMM_CHANNEL_STATE_VAR_RCVD_MSC_CMD    = 1 << 4,
106     RFCOMM_CHANNEL_STATE_VAR_RCVD_MSC_RSP    = 1 << 5,
107     RFCOMM_CHANNEL_STATE_VAR_SEND_PN_RSP     = 1 << 6,
108     RFCOMM_CHANNEL_STATE_VAR_SEND_RPN_INFO   = 1 << 7,
109 
110     RFCOMM_CHANNEL_STATE_VAR_SEND_RPN_RSP    = 1 << 8,
111     RFCOMM_CHANNEL_STATE_VAR_SEND_UA         = 1 << 9,
112     RFCOMM_CHANNEL_STATE_VAR_SEND_MSC_CMD    = 1 << 10,
113     RFCOMM_CHANNEL_STATE_VAR_SEND_MSC_RSP    = 1 << 11,
114 
115     RFCOMM_CHANNEL_STATE_VAR_SEND_CREDITS    = 1 << 12,
116     RFCOMM_CHANNEL_STATE_VAR_SENT_MSC_CMD    = 1 << 13,
117     RFCOMM_CHANNEL_STATE_VAR_SENT_MSC_RSP    = 1 << 14,
118     RFCOMM_CHANNEL_STATE_VAR_SENT_CREDITS    = 1 << 15,
119 } RFCOMM_CHANNEL_STATE_VAR;
120 
121 typedef struct rfcomm_rpn_data {
122     uint8_t baud_rate;
123     uint8_t flags;
124     uint8_t flow_control;
125     uint8_t xon;
126     uint8_t xoff;
127     uint8_t parameter_mask_0;   // first byte
128     uint8_t parameter_mask_1;   // second byte
129 } rfcomm_rpn_data_t;
130 
131 // info regarding potential connections
132 typedef struct {
133     // linked list - assert: first field
134     btstack_linked_item_t    item;
135 
136     // packet handler
137     btstack_packet_handler_t packet_handler;
138 
139     // server channel
140     uint8_t server_channel;
141 
142     // incoming max frame size
143     uint16_t max_frame_size;
144 
145     // use incoming flow control
146     uint8_t incoming_flow_control;
147 
148     // initial incoming credits
149     uint8_t incoming_initial_credits;
150 
151 
152 } rfcomm_service_t;
153 
154 // info regarding multiplexer
155 // note: spec mandates single multiplexer per device combination
156 typedef struct {
157     // linked list - assert: first field
158     btstack_linked_item_t    item;
159 
160     btstack_timer_source_t   timer;
161     int              timer_active;
162 
163 	RFCOMM_MULTIPLEXER_STATE state;
164 
165     uint16_t  l2cap_cid;
166 
167     uint8_t   fcon; // only send if fcon & 1, send rsp if fcon & 0x80
168 
169 	bd_addr_t remote_addr;
170     hci_con_handle_t con_handle;
171 
172 	uint8_t   outgoing;
173 
174     // hack to deal with authentication failure only observed by remote side
175     uint8_t at_least_one_connection;
176 
177     uint16_t max_frame_size;
178 
179     // send DM for DLCI != 0
180     uint8_t send_dm_for_dlci;
181 
182     // non supported command, 0 if not set
183     uint8_t nsc_command;
184 
185     // ertm id
186     uint16_t ertm_id;
187 
188     // test data - limited to RFCOMM_TEST_DATA_MAX_LEN
189     uint8_t test_data_len;
190     uint8_t test_data[RFCOMM_TEST_DATA_MAX_LEN];
191 
192 } rfcomm_multiplexer_t;
193 
194 // info regarding an actual connection
195 typedef struct {
196 
197     // linked list - assert: first field
198     btstack_linked_item_t    item;
199 
200     // packet handler
201     btstack_packet_handler_t packet_handler;
202 
203     // server channel (see rfcomm_service_t) - NULL => outgoing channel
204     rfcomm_service_t * service;
205 
206 	// muliplexer for this channel
207     rfcomm_multiplexer_t *multiplexer;
208 
209     // RFCOMM Channel ID
210     uint16_t rfcomm_cid;
211 
212     //
213     uint8_t  dlci;
214 
215     // credits for outgoing traffic
216     uint8_t credits_outgoing;
217 
218     // number of packets remote will be granted
219     uint8_t new_credits_incoming;
220 
221     // credits for incoming traffic
222     uint8_t credits_incoming;
223 
224     // use incoming flow control
225     uint8_t incoming_flow_control;
226 
227     // channel state
228     RFCOMM_CHANNEL_STATE state;
229 
230     // state variables used in RFCOMM_CHANNEL_INCOMING
231     RFCOMM_CHANNEL_STATE_VAR state_var;
232 
233     // priority set by incoming side in PN
234     uint8_t pn_priority;
235 
236 	// negotiated frame size
237     uint16_t max_frame_size;
238 
239     // local rpn data
240     rfcomm_rpn_data_t rpn_data;
241 
242     // rls line status. RFCOMM_RLS_STATUS_INVALID if not set
243     uint8_t rls_line_status;
244 
245     // msc modem status.
246     uint8_t msc_modem_status;
247 
248     //
249     uint8_t   waiting_for_can_send_now;
250 
251 } rfcomm_channel_t;
252 
253 // struct used in ERTM callback
254 typedef struct {
255     // remote address
256     bd_addr_t             addr;
257 
258     // ERTM ID - returned in RFCOMM_EVENT_ERTM_BUFFER_RELEASED.
259     uint16_t              ertm_id;
260 
261     // ERTM Configuration - needs to stay valid indefinitely
262     l2cap_ertm_config_t * ertm_config;
263 
264     // ERTM buffer
265     uint8_t *             ertm_buffer;
266     uint32_t              ertm_buffer_size;
267 } rfcomm_ertm_request_t;
268 
269 /* API_START */
270 
271 /**
272  * @brief Set up RFCOMM.
273  */
274 void rfcomm_init(void);
275 
276 /**
277  * @brief Set security level required for incoming connections, need to be called before registering services.
278  * @deprecated use gap_set_security_level instead
279  */
280 void rfcomm_set_required_security_level(gap_security_level_t security_level);
281 
282 /*
283  * @brief Create RFCOMM connection to a given server channel on a remote deivce.
284  * This channel will automatically provide enough credits to the remote side.
285  * @param addr
286  * @param server_channel
287  * @param out_cid
288  * @result status
289  */
290 uint8_t rfcomm_create_channel(btstack_packet_handler_t packet_handler, bd_addr_t addr, uint8_t server_channel, uint16_t * out_cid);
291 
292 /*
293  * @brief Create RFCOMM connection to a given server channel on a remote deivce.
294  * This channel will use explicit credit management. During channel establishment, an initial  amount of credits is provided.
295  * @param addr
296  * @param server_channel
297  * @param initial_credits
298  * @param out_cid
299  * @result status
300  */
301 uint8_t rfcomm_create_channel_with_initial_credits(btstack_packet_handler_t packet_handler, bd_addr_t addr, uint8_t server_channel, uint8_t initial_credits, uint16_t * out_cid);
302 
303 /**
304  * @brief Disconnects RFCOMM channel with given identifier.
305  */
306 void rfcomm_disconnect(uint16_t rfcomm_cid);
307 
308 /**
309  * @brief Registers RFCOMM service for a server channel and a maximum frame size, and assigns a packet handler.
310  * This channel provides credits automatically to the remote side -> no flow control
311  * @param packet handler for all channels of this service
312  * @param channel
313  * @param max_frame_size
314  * @return status ERROR_CODE_SUCCESS if successful, otherwise L2CAP_SERVICE_ALREADY_REGISTERED or BTSTACK_MEMORY_ALLOC_FAILED
315  */
316 uint8_t rfcomm_register_service(btstack_packet_handler_t packet_handler, uint8_t channel, uint16_t max_frame_size);
317 
318 /**
319  * @brief Registers RFCOMM service for a server channel and a maximum frame size, and assigns a packet handler.
320  * This channel will use explicit credit management. During channel establishment, an initial amount of credits is provided.
321  * @param packet handler for all channels of this service
322  * @param channel
323  * @param max_frame_size
324  * @param initial_credits
325  * @return status ERROR_CODE_SUCCESS if successful, otherwise L2CAP_SERVICE_ALREADY_REGISTERED or BTSTACK_MEMORY_ALLOC_FAILED
326  */
327 uint8_t rfcomm_register_service_with_initial_credits(btstack_packet_handler_t packet_handler, uint8_t channel, uint16_t max_frame_size, uint8_t initial_credits);
328 
329 /**
330  * @brief Unregister RFCOMM service.
331  */
332 void rfcomm_unregister_service(uint8_t service_channel);
333 
334 /**
335  * @brief Accepts incoming RFCOMM connection.
336  */
337 void rfcomm_accept_connection(uint16_t rfcomm_cid);
338 
339 /**
340  * @brief Deny incoming RFCOMM connection.
341  */
342 void rfcomm_decline_connection(uint16_t rfcomm_cid);
343 
344 /**
345  * @brief Grant more incoming credits to the remote side for the given RFCOMM channel identifier.
346  */
347 void rfcomm_grant_credits(uint16_t rfcomm_cid, uint8_t credits);
348 
349 /**
350  * @brief Checks if RFCOMM can send packet.
351  * @param rfcomm_cid
352  * @result != 0 if can send now
353  */
354 int rfcomm_can_send_packet_now(uint16_t rfcomm_cid);
355 
356 /**
357  * @brief Request emission of RFCOMM_EVENT_CAN_SEND_NOW as soon as possible
358  * @note RFCOMM_EVENT_CAN_SEND_NOW might be emitted during call to this function
359  *       so packet handler should be ready to handle it
360  * @param rfcomm_cid
361  */
362 void rfcomm_request_can_send_now_event(uint16_t rfcomm_cid);
363 
364 /**
365  * @brief Sends RFCOMM data packet to the RFCOMM channel with given identifier.
366  * @param rfcomm_cid
367  */
368 int  rfcomm_send(uint16_t rfcomm_cid, uint8_t *data, uint16_t len);
369 
370 /**
371  * @brief Sends Local Line Status, see LINE_STATUS_..
372  * @param rfcomm_cid
373  * @param line_status
374  */
375 int rfcomm_send_local_line_status(uint16_t rfcomm_cid, uint8_t line_status);
376 
377 /**
378  * @brief Send local modem status. see MODEM_STAUS_..
379  * @param rfcomm_cid
380  * @param modem_status
381  */
382 int rfcomm_send_modem_status(uint16_t rfcomm_cid, uint8_t modem_status);
383 
384 /**
385  * @brief Configure remote port
386  * @param rfcomm_cid
387  * @param baud_rate
388  * @param data_bits
389  * @param stop_bits
390  * @param parity
391  * @param flow_control
392  */
393 int rfcomm_send_port_configuration(uint16_t rfcomm_cid, rpn_baud_t baud_rate, rpn_data_bits_t data_bits, rpn_stop_bits_t stop_bits, rpn_parity_t parity, rpn_flow_control_t flow_control);
394 
395 /**
396  * @brief Query remote port
397  * @param rfcomm_cid
398  */
399 int rfcomm_query_port_configuration(uint16_t rfcomm_cid);
400 
401 /**
402  * @brief Query max frame size
403  * @param rfcomm_cid
404  */
405 uint16_t  rfcomm_get_max_frame_size(uint16_t rfcomm_cid);
406 
407 /**
408  * @brief Allow to create RFCOMM packet in outgoing buffer.
409  * if (rfcomm_can_send_packet_now(cid)){
410  *     rfcomm_reserve_packet_buffer();
411  *     uint8_t * buffer = rfcomm_get_outgoing_buffer();
412  *     uint16_t buffer_size = rfcomm_get_max_frame_size(cid);
413  *     .. setup data in buffer with len ..
414  *     rfcomm_send_prepared(cid, len)
415  * }
416  */
417 int       rfcomm_reserve_packet_buffer(void);
418 uint8_t * rfcomm_get_outgoing_buffer(void);
419 int       rfcomm_send_prepared(uint16_t rfcomm_cid, uint16_t len);
420 void      rfcomm_release_packet_buffer(void);
421 
422 /**
423  * @brief Enable L2CAP ERTM mode for RFCOMM. request callback is used to provide ERTM buffer. released callback returns buffer
424  *
425  * @note on request_callback, the app must set the ertm_config, buffer, size fields to enable ERTM for the current connection
426  * @note if buffer is not set, BASIC mode will be used instead
427  *
428  * @note released_callback provides ertm_id from earlier request to match request and release
429  *
430  * @param request_callback
431  * @param released_callback
432  */
433 void rfcomm_enable_l2cap_ertm(void request_callback(rfcomm_ertm_request_t * request), void released_callback(uint16_t ertm_id));
434 
435 /**
436  * @brief De-Init RFCOMM
437  */
438 void rfcomm_deinit(void);
439 
440 /* API_END */
441 
442 #if defined __cplusplus
443 }
444 #endif
445 
446 #endif // RFCOMM_H
447