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 collection of utility functions used the RFCOMM unit
22 *
23 *****************************************************************************/
24
25 #include <cstdint>
26
27 #include "bt_target.h"
28 #include "osi/include/allocator.h"
29 #include "osi/include/osi.h" // UNUSED_ATTR
30 #include "stack/include/bt_hdr.h"
31 #include "stack/include/port_ext.h"
32 #include "stack/rfcomm/rfc_int.h"
33 #include "types/raw_address.h"
34
35 #include <base/logging.h>
36
37 /*******************************************************************************
38 *
39 * Function rfc_calc_fcs
40 *
41 * Description Reversed CRC Table , 8-bit, poly=0x07
42 * (GSM 07.10 TS 101 369 V6.3.0)
43 ******************************************************************************/
44 static const uint8_t rfc_crctable[] = {
45 0x00, 0x91, 0xE3, 0x72, 0x07, 0x96, 0xE4, 0x75, 0x0E, 0x9F, 0xED,
46 0x7C, 0x09, 0x98, 0xEA, 0x7B, 0x1C, 0x8D, 0xFF, 0x6E, 0x1B, 0x8A,
47 0xF8, 0x69, 0x12, 0x83, 0xF1, 0x60, 0x15, 0x84, 0xF6, 0x67, 0x38,
48 0xA9, 0xDB, 0x4A, 0x3F, 0xAE, 0xDC, 0x4D, 0x36, 0xA7, 0xD5, 0x44,
49 0x31, 0xA0, 0xD2, 0x43, 0x24, 0xB5, 0xC7, 0x56, 0x23, 0xB2, 0xC0,
50 0x51, 0x2A, 0xBB, 0xC9, 0x58, 0x2D, 0xBC, 0xCE, 0x5F,
51
52 0x70, 0xE1, 0x93, 0x02, 0x77, 0xE6, 0x94, 0x05, 0x7E, 0xEF, 0x9D,
53 0x0C, 0x79, 0xE8, 0x9A, 0x0B, 0x6C, 0xFD, 0x8F, 0x1E, 0x6B, 0xFA,
54 0x88, 0x19, 0x62, 0xF3, 0x81, 0x10, 0x65, 0xF4, 0x86, 0x17, 0x48,
55 0xD9, 0xAB, 0x3A, 0x4F, 0xDE, 0xAC, 0x3D, 0x46, 0xD7, 0xA5, 0x34,
56 0x41, 0xD0, 0xA2, 0x33, 0x54, 0xC5, 0xB7, 0x26, 0x53, 0xC2, 0xB0,
57 0x21, 0x5A, 0xCB, 0xB9, 0x28, 0x5D, 0xCC, 0xBE, 0x2F,
58
59 0xE0, 0x71, 0x03, 0x92, 0xE7, 0x76, 0x04, 0x95, 0xEE, 0x7F, 0x0D,
60 0x9C, 0xE9, 0x78, 0x0A, 0x9B, 0xFC, 0x6D, 0x1F, 0x8E, 0xFB, 0x6A,
61 0x18, 0x89, 0xF2, 0x63, 0x11, 0x80, 0xF5, 0x64, 0x16, 0x87, 0xD8,
62 0x49, 0x3B, 0xAA, 0xDF, 0x4E, 0x3C, 0xAD, 0xD6, 0x47, 0x35, 0xA4,
63 0xD1, 0x40, 0x32, 0xA3, 0xC4, 0x55, 0x27, 0xB6, 0xC3, 0x52, 0x20,
64 0xB1, 0xCA, 0x5B, 0x29, 0xB8, 0xCD, 0x5C, 0x2E, 0xBF,
65
66 0x90, 0x01, 0x73, 0xE2, 0x97, 0x06, 0x74, 0xE5, 0x9E, 0x0F, 0x7D,
67 0xEC, 0x99, 0x08, 0x7A, 0xEB, 0x8C, 0x1D, 0x6F, 0xFE, 0x8B, 0x1A,
68 0x68, 0xF9, 0x82, 0x13, 0x61, 0xF0, 0x85, 0x14, 0x66, 0xF7, 0xA8,
69 0x39, 0x4B, 0xDA, 0xAF, 0x3E, 0x4C, 0xDD, 0xA6, 0x37, 0x45, 0xD4,
70 0xA1, 0x30, 0x42, 0xD3, 0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50,
71 0xC1, 0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF};
72
73 /*******************************************************************************
74 *
75 * Function rfc_calc_fcs
76 *
77 * Description This function calculate FCS for the RFCOMM frame
78 * (GSM 07.10 TS 101 369 V6.3.0)
79 *
80 * Input len - number of bytes in the message
81 * p - points to message
82 *
83 ******************************************************************************/
rfc_calc_fcs(uint16_t len,uint8_t * p)84 uint8_t rfc_calc_fcs(uint16_t len, uint8_t* p) {
85 uint8_t fcs = 0xFF;
86
87 while (len--) {
88 fcs = rfc_crctable[fcs ^ *p++];
89 }
90
91 /* Ones compliment */
92 return (0xFF - fcs);
93 }
94
95 /*******************************************************************************
96 *
97 * Function rfc_check_fcs
98 *
99 * Description This function checks FCS for the RFCOMM frame
100 * (GSM 07.10 TS 101 369 V6.3.0)
101 *
102 * Input len - number of bytes in the message
103 * p - points to message
104 * received_fcs - received FCS
105 *
106 ******************************************************************************/
rfc_check_fcs(uint16_t len,uint8_t * p,uint8_t received_fcs)107 bool rfc_check_fcs(uint16_t len, uint8_t* p, uint8_t received_fcs) {
108 uint8_t fcs = 0xFF;
109
110 while (len--) {
111 fcs = rfc_crctable[fcs ^ *p++];
112 }
113
114 /* Ones compliment */
115 fcs = rfc_crctable[fcs ^ received_fcs];
116
117 /*0xCF is the reversed order of 11110011.*/
118 return (fcs == 0xCF);
119 }
120
121 /*******************************************************************************
122 *
123 * Function rfc_alloc_multiplexer_channel
124 *
125 * Description This function returns existing or new control block for
126 * the address.
127 *
128 ******************************************************************************/
rfc_alloc_multiplexer_channel(const RawAddress & bd_addr,bool is_initiator)129 tRFC_MCB* rfc_alloc_multiplexer_channel(const RawAddress& bd_addr,
130 bool is_initiator) {
131 int i, j;
132 tRFC_MCB* p_mcb = NULL;
133 VLOG(1) << __func__ << ": bd_addr:" << ADDRESS_TO_LOGGABLE_STR(bd_addr);
134 RFCOMM_TRACE_DEBUG("rfc_alloc_multiplexer_channel:is_initiator:%d",
135 is_initiator);
136
137 for (i = 0; i < MAX_BD_CONNECTIONS; i++) {
138 RFCOMM_TRACE_DEBUG(
139 "rfc_alloc_multiplexer_channel rfc_cb.port.rfc_mcb[%d].state:%d", i,
140 rfc_cb.port.rfc_mcb[i].state);
141 VLOG(1) << "(rfc_cb.port.rfc_mcb[i].bd_addr:"
142 << ADDRESS_TO_LOGGABLE_STR(rfc_cb.port.rfc_mcb[i].bd_addr);
143
144 if ((rfc_cb.port.rfc_mcb[i].state != RFC_MX_STATE_IDLE) &&
145 rfc_cb.port.rfc_mcb[i].bd_addr == bd_addr) {
146 /* Multiplexer channel found do not change anything */
147 /* If there was an inactivity timer running stop it now */
148 if (rfc_cb.port.rfc_mcb[i].state == RFC_MX_STATE_CONNECTED)
149 rfc_timer_stop(&rfc_cb.port.rfc_mcb[i]);
150 RFCOMM_TRACE_DEBUG(
151 "rfc_alloc_multiplexer_channel:is_initiator:%d, found, state:%d, "
152 "p_mcb:%p",
153 is_initiator, rfc_cb.port.rfc_mcb[i].state, &rfc_cb.port.rfc_mcb[i]);
154 return (&rfc_cb.port.rfc_mcb[i]);
155 }
156 }
157
158 /* connection with bd_addr does not exist */
159 for (i = 0, j = rfc_cb.rfc.last_mux + 1; i < MAX_BD_CONNECTIONS; i++, j++) {
160 if (j >= MAX_BD_CONNECTIONS) j = 0;
161
162 p_mcb = &rfc_cb.port.rfc_mcb[j];
163 if (rfc_cb.port.rfc_mcb[j].state == RFC_MX_STATE_IDLE) {
164 /* New multiplexer control block */
165 alarm_free(p_mcb->mcb_timer);
166 fixed_queue_free(p_mcb->cmd_q, NULL);
167 memset(p_mcb, 0, sizeof(tRFC_MCB));
168 p_mcb->bd_addr = bd_addr;
169 RFCOMM_TRACE_DEBUG(
170 "rfc_alloc_multiplexer_channel:is_initiator:%d, create new p_mcb:%p, "
171 "index:%d",
172 is_initiator, &rfc_cb.port.rfc_mcb[j], j);
173
174 p_mcb->mcb_timer = alarm_new("rfcomm_mcb.mcb_timer");
175 p_mcb->cmd_q = fixed_queue_new(SIZE_MAX);
176
177 p_mcb->is_initiator = is_initiator;
178
179 rfc_timer_start(p_mcb, RFC_MCB_INIT_INACT_TIMER);
180
181 rfc_cb.rfc.last_mux = (uint8_t)j;
182 return (p_mcb);
183 }
184 }
185 return (NULL);
186 }
187
188 /*******************************************************************************
189 *
190 * Function rfc_release_multiplexer_channel
191 *
192 * Description Release a multiplexer control block
193 *
194 ******************************************************************************/
rfc_release_multiplexer_channel(tRFC_MCB * p_mcb)195 void rfc_release_multiplexer_channel(tRFC_MCB* p_mcb) {
196 /* Remove the MCB from the mapping table */
197 rfc_save_lcid_mcb(NULL, p_mcb->lcid);
198
199 /* Remove the MCB from the ports */
200 for (int i = 0; i < MAX_RFC_PORTS; i++) {
201 if (rfc_cb.port.port[i].rfc.p_mcb == p_mcb)
202 rfc_cb.port.port[i].rfc.p_mcb = NULL;
203 }
204
205 rfc_timer_stop(p_mcb);
206 alarm_free(p_mcb->mcb_timer);
207
208 fixed_queue_free(p_mcb->cmd_q, osi_free);
209
210 memset(p_mcb, 0, sizeof(tRFC_MCB));
211 p_mcb->state = RFC_MX_STATE_IDLE;
212 }
213
214 /*******************************************************************************
215 *
216 * Function rfc_timer_start
217 *
218 * Description Start RFC Timer
219 *
220 ******************************************************************************/
rfc_timer_start(tRFC_MCB * p_mcb,uint16_t timeout)221 void rfc_timer_start(tRFC_MCB* p_mcb, uint16_t timeout) {
222 RFCOMM_TRACE_EVENT("%s - timeout:%d seconds", __func__, timeout);
223
224 uint64_t interval_ms = timeout * 1000;
225 alarm_set_on_mloop(p_mcb->mcb_timer, interval_ms, rfcomm_mcb_timer_timeout,
226 p_mcb);
227 }
228
229 /*******************************************************************************
230 *
231 * Function rfc_timer_stop
232 *
233 * Description Stop RFC Timer
234 *
235 ******************************************************************************/
rfc_timer_stop(tRFC_MCB * p_mcb)236 void rfc_timer_stop(tRFC_MCB* p_mcb) {
237 RFCOMM_TRACE_EVENT("%s", __func__);
238
239 alarm_cancel(p_mcb->mcb_timer);
240 }
241
242 /*******************************************************************************
243 *
244 * Function rfc_port_timer_start
245 *
246 * Description Start RFC Timer
247 *
248 ******************************************************************************/
rfc_port_timer_start(tPORT * p_port,uint16_t timeout)249 void rfc_port_timer_start(tPORT* p_port, uint16_t timeout) {
250 RFCOMM_TRACE_EVENT("%s - timeout:%d seconds", __func__, timeout);
251
252 uint64_t interval_ms = timeout * 1000;
253 alarm_set_on_mloop(p_port->rfc.port_timer, interval_ms,
254 rfcomm_port_timer_timeout, p_port);
255 }
256
257 /*******************************************************************************
258 *
259 * Function rfc_port_timer_stop
260 *
261 * Description Stop RFC Timer
262 *
263 ******************************************************************************/
rfc_port_timer_stop(tPORT * p_port)264 void rfc_port_timer_stop(tPORT* p_port) {
265 RFCOMM_TRACE_EVENT("%s", __func__);
266
267 alarm_cancel(p_port->rfc.port_timer);
268 }
269
270 /*******************************************************************************
271 *
272 * Function rfc_check_mcb_active
273 *
274 * Description Check if there are any opened ports on the MCB if not
275 * start MCB Inact timer.
276 *
277 * Returns void
278 *
279 ******************************************************************************/
rfc_check_mcb_active(tRFC_MCB * p_mcb)280 void rfc_check_mcb_active(tRFC_MCB* p_mcb) {
281 uint16_t i;
282
283 for (i = 0; i < RFCOMM_MAX_DLCI; i++) {
284 if (p_mcb->port_handles[i] != 0) {
285 p_mcb->is_disc_initiator = false;
286 return;
287 }
288 }
289 /* The last port was DISCed. On the client side start disconnecting Mx */
290 /* On the server side start inactivity timer */
291 if (p_mcb->is_disc_initiator) {
292 p_mcb->is_disc_initiator = false;
293 rfc_mx_sm_execute(p_mcb, RFC_MX_EVENT_CLOSE_REQ, NULL);
294 } else
295 rfc_timer_start(p_mcb, RFC_MCB_RELEASE_INACT_TIMER);
296 }
297
rfcomm_port_timer_timeout(void * data)298 void rfcomm_port_timer_timeout(void* data) {
299 tPORT* p_port = (tPORT*)data;
300
301 rfc_port_sm_execute(p_port, RFC_PORT_EVENT_TIMEOUT, NULL);
302 }
303
rfcomm_mcb_timer_timeout(void * data)304 void rfcomm_mcb_timer_timeout(void* data) {
305 tRFC_MCB* p_mcb = (tRFC_MCB*)data;
306
307 rfc_mx_sm_execute(p_mcb, RFC_MX_EVENT_TIMEOUT, NULL);
308 }
309
310 /*******************************************************************************
311 *
312 * Function rfc_sec_check_complete
313 *
314 * Description The function called when Security Manager finishes
315 * verification of the service side connection
316 *
317 * Returns void
318 *
319 ******************************************************************************/
rfc_sec_check_complete(UNUSED_ATTR const RawAddress * bd_addr,UNUSED_ATTR tBT_TRANSPORT transport,void * p_ref_data,tBTM_STATUS res)320 void rfc_sec_check_complete(UNUSED_ATTR const RawAddress* bd_addr,
321 UNUSED_ATTR tBT_TRANSPORT transport,
322 void* p_ref_data, tBTM_STATUS res) {
323 CHECK(p_ref_data != nullptr);
324 tPORT* p_port = (tPORT*)p_ref_data;
325
326 /* Verify that PORT is still waiting for Security to complete */
327 if (!p_port->in_use ||
328 ((p_port->rfc.state != RFC_STATE_ORIG_WAIT_SEC_CHECK) &&
329 (p_port->rfc.state != RFC_STATE_TERM_WAIT_SEC_CHECK)))
330 return;
331
332 rfc_port_sm_execute((tPORT*)p_ref_data, RFC_PORT_EVENT_SEC_COMPLETE, &res);
333 }
334
335 /*******************************************************************************
336 *
337 * Function rfc_port_closed
338 *
339 * Description The function is called when port is released based on the
340 * event received from the lower layer, typically L2CAP
341 * connection down, DISC, or DM frame.
342 *
343 * Returns void
344 *
345 ******************************************************************************/
rfc_port_closed(tPORT * p_port)346 void rfc_port_closed(tPORT* p_port) {
347 tRFC_MCB* p_mcb = p_port->rfc.p_mcb;
348 rfc_port_timer_stop(p_port);
349 p_port->rfc.state = RFC_STATE_CLOSED;
350
351 /* If multiplexer channel was up mark it as down */
352 if (p_mcb) {
353 p_mcb->port_handles[p_port->dlci] = 0;
354
355 /* If there are no more ports opened on this MCB release it */
356 rfc_check_mcb_active(p_mcb);
357 }
358
359 /* Notify port that RFC connection is gone */
360 port_rfc_closed(p_port, PORT_CLOSED);
361 }
362
363 /*******************************************************************************
364 *
365 * Function rfc_inc_credit
366 *
367 * Description The function is called when a credit is received in a UIH
368 * frame. It increments the TX credit count, and if data
369 * flow had halted, it restarts it.
370 *
371 * Returns void
372 *
373 ******************************************************************************/
rfc_inc_credit(tPORT * p_port,uint8_t credit)374 void rfc_inc_credit(tPORT* p_port, uint8_t credit) {
375 if (p_port->rfc.p_mcb->flow == PORT_FC_CREDIT) {
376 p_port->credit_tx += credit;
377
378 RFCOMM_TRACE_EVENT("rfc_inc_credit:%d", p_port->credit_tx);
379
380 if (p_port->tx.peer_fc) PORT_FlowInd(p_port->rfc.p_mcb, p_port->dlci, true);
381 }
382 }
383
384 /*******************************************************************************
385 *
386 * Function rfc_dec_credit
387 *
388 * Description The function is called when a UIH frame of user data is
389 * sent. It decrements the credit count. If credit count
390 * Reaches zero, peer_fc is set.
391 *
392 * Returns void
393 *
394 ******************************************************************************/
rfc_dec_credit(tPORT * p_port)395 void rfc_dec_credit(tPORT* p_port) {
396 if (p_port->rfc.p_mcb->flow == PORT_FC_CREDIT) {
397 if (p_port->credit_tx > 0) p_port->credit_tx--;
398
399 if (p_port->credit_tx == 0) p_port->tx.peer_fc = true;
400 }
401 }
402
403 /*******************************************************************************
404 *
405 * Function rfc_check_send_cmd
406 *
407 * Description This function is called to send an RFCOMM command message
408 * or to handle the RFCOMM command message queue.
409 *
410 * Returns void
411 *
412 ******************************************************************************/
rfc_check_send_cmd(tRFC_MCB * p_mcb,BT_HDR * p_buf)413 void rfc_check_send_cmd(tRFC_MCB* p_mcb, BT_HDR* p_buf) {
414 /* if passed a buffer queue it */
415 if (p_buf != NULL) {
416 if (p_mcb->cmd_q == NULL) {
417 RFCOMM_TRACE_ERROR(
418 "%s: empty queue: p_mcb = %p p_mcb->lcid = %u cached p_mcb = %p",
419 __func__, p_mcb, p_mcb->lcid, rfc_find_lcid_mcb(p_mcb->lcid));
420 }
421 fixed_queue_enqueue(p_mcb->cmd_q, p_buf);
422 }
423
424 /* handle queue if L2CAP not congested */
425 while (!p_mcb->l2cap_congested) {
426 BT_HDR* p = (BT_HDR*)fixed_queue_try_dequeue(p_mcb->cmd_q);
427 if (p == NULL) break;
428 L2CA_DataWrite(p_mcb->lcid, p);
429 }
430 }
431