xref: /btstack/src/classic/rfcomm.h (revision a7a98a14513a32bb8a1b7d8f69d92f3c9f0b8988)
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  *  RFCOMM.h
40  */
41 
42 #ifndef __RFCOMM_H
43 #define __RFCOMM_H
44 
45 #include "btstack_util.h"
46 
47 #include <stdint.h>
48 #include "btstack_run_loop.h"
49 #include "gap.h"
50 
51 #if defined __cplusplus
52 extern "C" {
53 #endif
54 
55 #define UNLIMITED_INCOMING_CREDITS 0xff
56 
57 #define RFCOMM_TEST_DATA_MAX_LEN 4
58 
59 #define RFCOMM_RLS_STATUS_INVALID 0xff
60 
61 
62 // private structs
63 typedef enum {
64 	RFCOMM_MULTIPLEXER_CLOSED = 1,
65 	RFCOMM_MULTIPLEXER_W4_CONNECT,  // outgoing
66 	RFCOMM_MULTIPLEXER_SEND_SABM_0,     //    "
67 	RFCOMM_MULTIPLEXER_W4_UA_0,     //    "
68 	RFCOMM_MULTIPLEXER_W4_SABM_0,   // incoming
69     RFCOMM_MULTIPLEXER_SEND_UA_0,
70 	RFCOMM_MULTIPLEXER_OPEN,
71     RFCOMM_MULTIPLEXER_SEND_UA_0_AND_DISC,
72     RFCOMM_MULTIPLEXER_SHUTTING_DOWN,
73 } RFCOMM_MULTIPLEXER_STATE;
74 
75 typedef enum {
76     MULT_EV_READY_TO_SEND = 1,
77 } RFCOMM_MULTIPLEXER_EVENT;
78 
79 typedef enum {
80 	RFCOMM_CHANNEL_CLOSED = 1,
81 	RFCOMM_CHANNEL_W4_MULTIPLEXER,
82 	RFCOMM_CHANNEL_SEND_UIH_PN,
83     RFCOMM_CHANNEL_W4_PN_RSP,
84 	RFCOMM_CHANNEL_SEND_SABM_W4_UA,
85 	RFCOMM_CHANNEL_W4_UA,
86     RFCOMM_CHANNEL_INCOMING_SETUP,
87     RFCOMM_CHANNEL_DLC_SETUP,
88 	RFCOMM_CHANNEL_OPEN,
89     RFCOMM_CHANNEL_SEND_UA_AFTER_DISC,
90     RFCOMM_CHANNEL_SEND_DISC,
91     RFCOMM_CHANNEL_W4_UA_AFTER_DISC,
92     RFCOMM_CHANNEL_SEND_DM,
93     RFCOMM_CHANNEL_EMIT_OPEN_FAILED_AND_DISCARD,
94 } RFCOMM_CHANNEL_STATE;
95 
96 typedef enum {
97     RFCOMM_CHANNEL_STATE_VAR_NONE            = 0,
98     RFCOMM_CHANNEL_STATE_VAR_CLIENT_ACCEPTED = 1 << 0,
99     RFCOMM_CHANNEL_STATE_VAR_RCVD_PN         = 1 << 1,
100     RFCOMM_CHANNEL_STATE_VAR_RCVD_RPN        = 1 << 2,
101     RFCOMM_CHANNEL_STATE_VAR_RCVD_SABM       = 1 << 3,
102 
103     RFCOMM_CHANNEL_STATE_VAR_RCVD_MSC_CMD    = 1 << 4,
104     RFCOMM_CHANNEL_STATE_VAR_RCVD_MSC_RSP    = 1 << 5,
105     RFCOMM_CHANNEL_STATE_VAR_SEND_PN_RSP     = 1 << 6,
106     RFCOMM_CHANNEL_STATE_VAR_SEND_RPN_INFO   = 1 << 7,
107 
108     RFCOMM_CHANNEL_STATE_VAR_SEND_RPN_RSP    = 1 << 8,
109     RFCOMM_CHANNEL_STATE_VAR_SEND_UA         = 1 << 9,
110     RFCOMM_CHANNEL_STATE_VAR_SEND_MSC_CMD    = 1 << 10,
111     RFCOMM_CHANNEL_STATE_VAR_SEND_MSC_RSP    = 1 << 11,
112 
113     RFCOMM_CHANNEL_STATE_VAR_SEND_CREDITS    = 1 << 12,
114     RFCOMM_CHANNEL_STATE_VAR_SENT_MSC_CMD    = 1 << 13,
115     RFCOMM_CHANNEL_STATE_VAR_SENT_MSC_RSP    = 1 << 14,
116     RFCOMM_CHANNEL_STATE_VAR_SENT_CREDITS    = 1 << 15,
117 } RFCOMM_CHANNEL_STATE_VAR;
118 
119 typedef struct rfcomm_rpn_data {
120     uint8_t baud_rate;
121     uint8_t flags;
122     uint8_t flow_control;
123     uint8_t xon;
124     uint8_t xoff;
125     uint8_t parameter_mask_0;   // first byte
126     uint8_t parameter_mask_1;   // second byte
127 } rfcomm_rpn_data_t;
128 
129 // info regarding potential connections
130 typedef struct {
131     // linked list - assert: first field
132     btstack_linked_item_t    item;
133 
134     // packet handler
135     btstack_packet_handler_t packet_handler;
136 
137     // server channel
138     uint8_t server_channel;
139 
140     // incoming max frame size
141     uint16_t max_frame_size;
142 
143     // use incoming flow control
144     uint8_t incoming_flow_control;
145 
146     // initial incoming credits
147     uint8_t incoming_initial_credits;
148 
149 
150 } rfcomm_service_t;
151 
152 // info regarding multiplexer
153 // note: spec mandates single multiplexer per device combination
154 typedef struct {
155     // linked list - assert: first field
156     btstack_linked_item_t    item;
157 
158     btstack_timer_source_t   timer;
159     int              timer_active;
160 
161 	RFCOMM_MULTIPLEXER_STATE state;
162 
163     uint16_t  l2cap_cid;
164 
165     uint8_t   fcon; // only send if fcon & 1, send rsp if fcon & 0x80
166 
167 	bd_addr_t remote_addr;
168     hci_con_handle_t con_handle;
169 
170 	uint8_t   outgoing;
171 
172     // hack to deal with authentication failure only observed by remote side
173     uint8_t at_least_one_connection;
174 
175     uint16_t max_frame_size;
176 
177     // send DM for DLCI != 0
178     uint8_t send_dm_for_dlci;
179 
180     // non supported command, 0 if not set
181     uint8_t nsc_command;
182 
183     // ertm id
184     uint16_t ertm_id;
185 
186     // test data - limited to RFCOMM_TEST_DATA_MAX_LEN
187     uint8_t test_data_len;
188     uint8_t test_data[RFCOMM_TEST_DATA_MAX_LEN];
189 
190 } rfcomm_multiplexer_t;
191 
192 // info regarding an actual connection
193 typedef struct {
194 
195     // linked list - assert: first field
196     btstack_linked_item_t    item;
197 
198     // packet handler
199     btstack_packet_handler_t packet_handler;
200 
201     // server channel (see rfcomm_service_t) - NULL => outgoing channel
202     rfcomm_service_t * service;
203 
204 	// muliplexer for this channel
205     rfcomm_multiplexer_t *multiplexer;
206 
207     // RFCOMM Channel ID
208     uint16_t rfcomm_cid;
209 
210     //
211     uint8_t  dlci;
212 
213     // credits for outgoing traffic
214     uint8_t credits_outgoing;
215 
216     // number of packets remote will be granted
217     uint8_t new_credits_incoming;
218 
219     // credits for incoming traffic
220     uint8_t credits_incoming;
221 
222     // use incoming flow control
223     uint8_t incoming_flow_control;
224 
225     // channel state
226     RFCOMM_CHANNEL_STATE state;
227 
228     // state variables used in RFCOMM_CHANNEL_INCOMING
229     RFCOMM_CHANNEL_STATE_VAR state_var;
230 
231     // priority set by incoming side in PN
232     uint8_t pn_priority;
233 
234 	// negotiated frame size
235     uint16_t max_frame_size;
236 
237     // local rpn data
238     rfcomm_rpn_data_t rpn_data;
239 
240     // rls line status. RFCOMM_RLS_STATUS_INVALID if not set
241     uint8_t rls_line_status;
242 
243     // msc modem status.
244     uint8_t msc_modem_status;
245 
246     //
247     uint8_t   waiting_for_can_send_now;
248 
249 } rfcomm_channel_t;
250 
251 // struct used in ERTM callback
252 typedef struct {
253     // remote address
254     bd_addr_t             addr;
255 
256     // ERTM ID - returned in RFCOMM_EVENT_ERTM_BUFFER_RELEASED.
257     uint16_t              ertm_id;
258 
259     // ERTM Configuration - needs to stay valid indefinitely
260     l2cap_ertm_config_t * ertm_config;
261 
262     // ERTM buffer
263     uint8_t *             ertm_buffer;
264     uint32_t              ertm_buffer_size;
265 } rfcomm_ertm_request_t;
266 
267 /* API_START */
268 
269 /**
270  * @brief Set up RFCOMM.
271  */
272 void rfcomm_init(void);
273 
274 /**
275  * @brief Set security level required for incoming connections, need to be called before registering services.
276  */
277 void rfcomm_set_required_security_level(gap_security_level_t security_level);
278 
279 /*
280  * @brief Create RFCOMM connection to a given server channel on a remote deivce.
281  * This channel will automatically provide enough credits to the remote side.
282  * @param addr
283  * @param server_channel
284  * @param out_cid
285  * @result status
286  */
287 uint8_t rfcomm_create_channel(btstack_packet_handler_t packet_handler, bd_addr_t addr, uint8_t server_channel, uint16_t * out_cid);
288 
289 /*
290  * @brief Create RFCOMM connection to a given server channel on a remote deivce.
291  * This channel will use explicit credit management. During channel establishment, an initial  amount of credits is provided.
292  * @param addr
293  * @param server_channel
294  * @param initial_credits
295  * @param out_cid
296  * @result status
297  */
298 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);
299 
300 /**
301  * @brief Disconnects RFCOMM channel with given identifier.
302  */
303 void rfcomm_disconnect(uint16_t rfcomm_cid);
304 
305 /**
306  * @brief Registers RFCOMM service for a server channel and a maximum frame size, and assigns a packet handler.
307  * This channel provides credits automatically to the remote side -> no flow control
308  * @param packet handler for all channels of this service
309  * @param channel
310  * @param max_frame_size
311  */
312 uint8_t rfcomm_register_service(btstack_packet_handler_t packet_handler, uint8_t channel, uint16_t max_frame_size);
313 
314 /**
315  * @brief Registers RFCOMM service for a server channel and a maximum frame size, and assigns a packet handler.
316  * This channel will use explicit credit management. During channel establishment, an initial amount of credits is provided.
317  * @param packet handler for all channels of this service
318  * @param channel
319  * @param max_frame_size
320  * @param initial_credits
321  */
322 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);
323 
324 /**
325  * @brief Unregister RFCOMM service.
326  */
327 void rfcomm_unregister_service(uint8_t service_channel);
328 
329 /**
330  * @brief Accepts incoming RFCOMM connection.
331  */
332 void rfcomm_accept_connection(uint16_t rfcomm_cid);
333 
334 /**
335  * @brief Deny incoming RFCOMM connection.
336  */
337 void rfcomm_decline_connection(uint16_t rfcomm_cid);
338 
339 /**
340  * @brief Grant more incoming credits to the remote side for the given RFCOMM channel identifier.
341  */
342 void rfcomm_grant_credits(uint16_t rfcomm_cid, uint8_t credits);
343 
344 /**
345  * @brief Checks if RFCOMM can send packet.
346  * @param rfcomm_cid
347  * @result != 0 if can send now
348  */
349 int rfcomm_can_send_packet_now(uint16_t rfcomm_cid);
350 
351 /**
352  * @brief Request emission of RFCOMM_EVENT_CAN_SEND_NOW as soon as possible
353  * @note RFCOMM_EVENT_CAN_SEND_NOW might be emitted during call to this function
354  *       so packet handler should be ready to handle it
355  * @param rfcomm_cid
356  */
357 void rfcomm_request_can_send_now_event(uint16_t rfcomm_cid);
358 
359 /**
360  * @brief Sends RFCOMM data packet to the RFCOMM channel with given identifier.
361  * @param rfcomm_cid
362  */
363 int  rfcomm_send(uint16_t rfcomm_cid, uint8_t *data, uint16_t len);
364 
365 /**
366  * @brief Sends Local Line Status, see LINE_STATUS_..
367  * @param rfcomm_cid
368  * @param line_status
369  */
370 int rfcomm_send_local_line_status(uint16_t rfcomm_cid, uint8_t line_status);
371 
372 /**
373  * @brief Send local modem status. see MODEM_STAUS_..
374  * @param rfcomm_cid
375  * @param modem_status
376  */
377 int rfcomm_send_modem_status(uint16_t rfcomm_cid, uint8_t modem_status);
378 
379 /**
380  * @brief Configure remote port
381  * @param rfcomm_cid
382  * @param baud_rate
383  * @param data_bits
384  * @param stop_bits
385  * @param parity
386  * @param flow_control
387  */
388 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);
389 
390 /**
391  * @brief Query remote port
392  * @param rfcomm_cid
393  */
394 int rfcomm_query_port_configuration(uint16_t rfcomm_cid);
395 
396 /**
397  * @brief Query max frame size
398  * @param rfcomm_cid
399  */
400 uint16_t  rfcomm_get_max_frame_size(uint16_t rfcomm_cid);
401 
402 /**
403  * @brief Allow to create RFCOMM packet in outgoing buffer.
404  * if (rfcomm_can_send_packet_now(cid)){
405  *     rfcomm_reserve_packet_buffer();
406  *     uint8_t * buffer = rfcomm_get_outgoing_buffer();
407  *     uint16_t buffer_size = rfcomm_get_max_frame_size(cid);
408  *     // .. setup data in buffer with len
409  *     rfcomm_send_prepared(cid, len)
410  * }
411  */
412 int       rfcomm_reserve_packet_buffer(void);
413 uint8_t * rfcomm_get_outgoing_buffer(void);
414 int       rfcomm_send_prepared(uint16_t rfcomm_cid, uint16_t len);
415 void      rfcomm_release_packet_buffer(void);
416 
417 /**
418  * @brief Enable L2CAP ERTM mode for RFCOMM. request callback is used to provide ERTM buffer. released callback returns buffer
419  *
420  * @note on request_callback, the app must set the ertm_config, buffer, size fields to enable ERTM for the current connection
421  * @note if buffer is not set, BASIC mode will be used instead
422  *
423  * @note released_callback provides ertm_id from earlier request to match request and release
424  *
425  * @param request_callback
426  * @param released_callback
427  */
428 void rfcomm_enable_l2cap_ertm(void request_callback(rfcomm_ertm_request_t * request), void released_callback(uint16_t ertm_id));
429 
430 /* API_END */
431 
432 #if defined __cplusplus
433 }
434 #endif
435 
436 #endif // __RFCOMM_H
437