1 /******************************************************************************
2  *
3  *  Copyright (C) 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 "bt_target.h"
26 #include "bt_common.h"
27 
28 #include "btm_api.h"
29 #include "btm_int.h"
30 #include "rfcdefs.h"
31 #include "port_api.h"
32 #include "port_ext.h"
33 #include "port_int.h"
34 #include "rfc_int.h"
35 #include "btu.h"
36 #include "bt_utils.h"
37 
38 #include <string.h>
39 
40 extern fixed_queue_t *btu_general_alarm_queue;
41 
42 /*******************************************************************************
43 **
44 ** Function         rfc_calc_fcs
45 **
46 ** Description      Reversed CRC Table , 8-bit, poly=0x07
47 **                  (GSM 07.10 TS 101 369 V6.3.0)
48 *******************************************************************************/
49 static const UINT8 rfc_crctable[] =
50 {
51     0x00, 0x91, 0xE3, 0x72, 0x07, 0x96, 0xE4, 0x75,  0x0E, 0x9F, 0xED, 0x7C, 0x09, 0x98, 0xEA, 0x7B,
52     0x1C, 0x8D, 0xFF, 0x6E, 0x1B, 0x8A, 0xF8, 0x69,  0x12, 0x83, 0xF1, 0x60, 0x15, 0x84, 0xF6, 0x67,
53     0x38, 0xA9, 0xDB, 0x4A, 0x3F, 0xAE, 0xDC, 0x4D,  0x36, 0xA7, 0xD5, 0x44, 0x31, 0xA0, 0xD2, 0x43,
54     0x24, 0xB5, 0xC7, 0x56, 0x23, 0xB2, 0xC0, 0x51,  0x2A, 0xBB, 0xC9, 0x58, 0x2D, 0xBC, 0xCE, 0x5F,
55 
56     0x70, 0xE1, 0x93, 0x02, 0x77, 0xE6, 0x94, 0x05,  0x7E, 0xEF, 0x9D, 0x0C, 0x79, 0xE8, 0x9A, 0x0B,
57     0x6C, 0xFD, 0x8F, 0x1E, 0x6B, 0xFA, 0x88, 0x19,  0x62, 0xF3, 0x81, 0x10, 0x65, 0xF4, 0x86, 0x17,
58     0x48, 0xD9, 0xAB, 0x3A, 0x4F, 0xDE, 0xAC, 0x3D,  0x46, 0xD7, 0xA5, 0x34, 0x41, 0xD0, 0xA2, 0x33,
59     0x54, 0xC5, 0xB7, 0x26, 0x53, 0xC2, 0xB0, 0x21,  0x5A, 0xCB, 0xB9, 0x28, 0x5D, 0xCC, 0xBE, 0x2F,
60 
61     0xE0, 0x71, 0x03, 0x92, 0xE7, 0x76, 0x04, 0x95,  0xEE, 0x7F, 0x0D, 0x9C, 0xE9, 0x78, 0x0A, 0x9B,
62     0xFC, 0x6D, 0x1F, 0x8E, 0xFB, 0x6A, 0x18, 0x89,  0xF2, 0x63, 0x11, 0x80, 0xF5, 0x64, 0x16, 0x87,
63     0xD8, 0x49, 0x3B, 0xAA, 0xDF, 0x4E, 0x3C, 0xAD,  0xD6, 0x47, 0x35, 0xA4, 0xD1, 0x40, 0x32, 0xA3,
64     0xC4, 0x55, 0x27, 0xB6, 0xC3, 0x52, 0x20, 0xB1,  0xCA, 0x5B, 0x29, 0xB8, 0xCD, 0x5C, 0x2E, 0xBF,
65 
66     0x90, 0x01, 0x73, 0xE2, 0x97, 0x06, 0x74, 0xE5,  0x9E, 0x0F, 0x7D, 0xEC, 0x99, 0x08, 0x7A, 0xEB,
67     0x8C, 0x1D, 0x6F, 0xFE, 0x8B, 0x1A, 0x68, 0xF9,  0x82, 0x13, 0x61, 0xF0, 0x85, 0x14, 0x66, 0xF7,
68     0xA8, 0x39, 0x4B, 0xDA, 0xAF, 0x3E, 0x4C, 0xDD,  0xA6, 0x37, 0x45, 0xD4, 0xA1, 0x30, 0x42, 0xD3,
69     0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50, 0xC1,  0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF
70 };
71 
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 len,UINT8 * p)84 UINT8 rfc_calc_fcs (UINT16 len, UINT8 *p)
85 {
86     UINT8  fcs = 0xFF;
87 
88     while (len--)
89     {
90         fcs = rfc_crctable[fcs ^ *p++];
91     }
92 
93     /* Ones compliment */
94     return (0xFF - fcs);
95 }
96 
97 
98 /*******************************************************************************
99 **
100 ** Function         rfc_check_fcs
101 **
102 ** Description      This function checks FCS for the RFCOMM frame
103 **                  (GSM 07.10 TS 101 369 V6.3.0)
104 **
105 ** Input            len          - number of bytes in the message
106 **                  p            - points to message
107 **                  received_fcs - received FCS
108 **
109 *******************************************************************************/
rfc_check_fcs(UINT16 len,UINT8 * p,UINT8 received_fcs)110 BOOLEAN rfc_check_fcs (UINT16 len, UINT8 *p, UINT8 received_fcs)
111 {
112     UINT8  fcs = 0xFF;
113 
114     while (len--)
115     {
116         fcs = rfc_crctable[fcs ^ *p++];
117     }
118 
119     /* Ones compliment */
120     fcs = rfc_crctable[fcs ^ received_fcs];
121 
122     /*0xCF is the reversed order of 11110011.*/
123     return (fcs == 0xCF);
124 }
125 
126 
127 /*******************************************************************************
128 **
129 ** Function         rfc_alloc_multiplexer_channel
130 **
131 ** Description      This function returns existing or new control block for
132 **                  the BD_ADDR.
133 **
134 *******************************************************************************/
rfc_alloc_multiplexer_channel(BD_ADDR bd_addr,BOOLEAN is_initiator)135 tRFC_MCB *rfc_alloc_multiplexer_channel (BD_ADDR bd_addr, BOOLEAN is_initiator)
136 {
137     int i, j;
138     tRFC_MCB *p_mcb = NULL;
139     RFCOMM_TRACE_DEBUG("rfc_alloc_multiplexer_channel: bd_addr:%02x:%02x:%02x:%02x:%02x:%02x",
140                                 bd_addr[0], bd_addr[1], bd_addr[2], bd_addr[3], bd_addr[4], bd_addr[5]);
141     RFCOMM_TRACE_DEBUG("rfc_alloc_multiplexer_channel:is_initiator:%d", is_initiator);
142 
143     for (i = 0; i < MAX_BD_CONNECTIONS; i++)
144     {
145         RFCOMM_TRACE_DEBUG("rfc_alloc_multiplexer_channel rfc_cb.port.rfc_mcb[%d].state:%d",
146                             i, rfc_cb.port.rfc_mcb[i].state);
147         RFCOMM_TRACE_DEBUG("(rfc_cb.port.rfc_mcb[i].bd_addr:%02x:%02x:%02x:%02x:%02x:%02x",
148                                 rfc_cb.port.rfc_mcb[i].bd_addr[0], rfc_cb.port.rfc_mcb[i].bd_addr[1],
149                                 rfc_cb.port.rfc_mcb[i].bd_addr[2], rfc_cb.port.rfc_mcb[i].bd_addr[3],
150                                 rfc_cb.port.rfc_mcb[i].bd_addr[4], rfc_cb.port.rfc_mcb[i].bd_addr[5]);
151 
152         if ((rfc_cb.port.rfc_mcb[i].state != RFC_MX_STATE_IDLE)
153          && (!memcmp (rfc_cb.port.rfc_mcb[i].bd_addr, bd_addr, BD_ADDR_LEN)))
154         {
155             /* Multiplexer channel found do not change anything */
156             /* If there was an inactivity timer running stop it now */
157             if (rfc_cb.port.rfc_mcb[i].state == RFC_MX_STATE_CONNECTED)
158                 rfc_timer_stop (&rfc_cb.port.rfc_mcb[i]);
159             RFCOMM_TRACE_DEBUG("rfc_alloc_multiplexer_channel:is_initiator:%d, found, state:%d, p_mcb:%p",
160                                 is_initiator, rfc_cb.port.rfc_mcb[i].state, &rfc_cb.port.rfc_mcb[i]);
161             return (&rfc_cb.port.rfc_mcb[i]);
162         }
163     }
164 
165     /* connection with bd_addr does not exist */
166     for (i = 0, j = rfc_cb.rfc.last_mux + 1; i < MAX_BD_CONNECTIONS; i++, j++)
167     {
168         if (j >= MAX_BD_CONNECTIONS)
169             j = 0;
170 
171         p_mcb = &rfc_cb.port.rfc_mcb[j];
172         if (rfc_cb.port.rfc_mcb[j].state == RFC_MX_STATE_IDLE)
173         {
174             /* New multiplexer control block */
175             alarm_free(p_mcb->mcb_timer);
176             fixed_queue_free(p_mcb->cmd_q, NULL);
177             memset (p_mcb, 0, sizeof (tRFC_MCB));
178             memcpy (p_mcb->bd_addr, bd_addr, BD_ADDR_LEN);
179             RFCOMM_TRACE_DEBUG("rfc_alloc_multiplexer_channel:is_initiator:%d, create new p_mcb:%p, index:%d",
180                                 is_initiator, &rfc_cb.port.rfc_mcb[j], j);
181 
182             p_mcb->mcb_timer = alarm_new("rfcomm_mcb.mcb_timer");
183             p_mcb->cmd_q = fixed_queue_new(SIZE_MAX);
184 
185             p_mcb->is_initiator = is_initiator;
186 
187             rfc_timer_start (p_mcb, RFC_MCB_INIT_INACT_TIMER);
188 
189             rfc_cb.rfc.last_mux = (UINT8) j;
190             return (p_mcb);
191         }
192     }
193     return (NULL);
194 }
195 
196 
197 /*******************************************************************************
198 **
199 ** Function         rfc_release_multiplexer_channel
200 **
201 ** Description      Release a multiplexer control block
202 **
203 *******************************************************************************/
rfc_release_multiplexer_channel(tRFC_MCB * p_mcb)204 void rfc_release_multiplexer_channel (tRFC_MCB *p_mcb)
205 {
206     /* Remove the MCB from the mapping table */
207     rfc_save_lcid_mcb(NULL, p_mcb->lcid);
208 
209     /* Remove the MCB from the ports */
210     for (int i = 0; i < MAX_RFC_PORTS; i++) {
211         if (rfc_cb.port.port[i].rfc.p_mcb == p_mcb)
212             rfc_cb.port.port[i].rfc.p_mcb = NULL;
213     }
214 
215     rfc_timer_stop (p_mcb);
216     alarm_free(p_mcb->mcb_timer);
217 
218     fixed_queue_free(p_mcb->cmd_q, osi_free);
219 
220     memset (p_mcb, 0, sizeof (tRFC_MCB));
221     p_mcb->state = RFC_MX_STATE_IDLE;
222 }
223 
224 
225 /*******************************************************************************
226 **
227 ** Function         rfc_timer_start
228 **
229 ** Description      Start RFC Timer
230 **
231 *******************************************************************************/
rfc_timer_start(tRFC_MCB * p_mcb,UINT16 timeout)232 void rfc_timer_start(tRFC_MCB *p_mcb, UINT16 timeout)
233 {
234     RFCOMM_TRACE_EVENT ("%s - timeout:%d seconds", __func__, timeout);
235 
236     period_ms_t interval_ms = timeout * 1000;
237     alarm_set_on_queue(p_mcb->mcb_timer, interval_ms,
238                        rfcomm_mcb_timer_timeout, p_mcb,
239                        btu_general_alarm_queue);
240 }
241 
242 
243 /*******************************************************************************
244 **
245 ** Function         rfc_timer_stop
246 **
247 ** Description      Stop RFC Timer
248 **
249 *******************************************************************************/
rfc_timer_stop(tRFC_MCB * p_mcb)250 void rfc_timer_stop(tRFC_MCB *p_mcb)
251 {
252     RFCOMM_TRACE_EVENT("%s", __func__);
253 
254     alarm_cancel(p_mcb->mcb_timer);
255 }
256 
257 
258 /*******************************************************************************
259 **
260 ** Function         rfc_port_timer_start
261 **
262 ** Description      Start RFC Timer
263 **
264 *******************************************************************************/
rfc_port_timer_start(tPORT * p_port,UINT16 timeout)265 void rfc_port_timer_start(tPORT *p_port, UINT16 timeout)
266 {
267     RFCOMM_TRACE_EVENT("%s - timeout:%d seconds", __func__, timeout);
268 
269     period_ms_t interval_ms = timeout * 1000;
270     alarm_set_on_queue(p_port->rfc.port_timer, interval_ms,
271                        rfcomm_port_timer_timeout, p_port,
272                        btu_general_alarm_queue);
273 }
274 
275 /*******************************************************************************
276 **
277 ** Function         rfc_port_timer_stop
278 **
279 ** Description      Stop RFC Timer
280 **
281 *******************************************************************************/
rfc_port_timer_stop(tPORT * p_port)282 void rfc_port_timer_stop(tPORT *p_port)
283 {
284     RFCOMM_TRACE_EVENT ("%s", __func__);
285 
286     alarm_cancel(p_port->rfc.port_timer);
287 }
288 
289 
290 /*******************************************************************************
291 **
292 ** Function         rfc_check_mcb_active
293 **
294 ** Description      Check if there are any opened ports on the MCB if not
295 **                  start MCB Inact timer.
296 **
297 ** Returns          void
298 **
299 *******************************************************************************/
rfc_check_mcb_active(tRFC_MCB * p_mcb)300 void rfc_check_mcb_active (tRFC_MCB *p_mcb)
301 {
302     UINT16 i;
303 
304     for (i = 0; i < RFCOMM_MAX_DLCI; i++)
305     {
306         if (p_mcb->port_inx[i] != 0)
307         {
308             p_mcb->is_disc_initiator = FALSE;
309             return;
310         }
311     }
312     /* The last port was DISCed.  On the client side start disconnecting Mx */
313     /* On the server side start inactivity timer */
314     if (p_mcb->is_disc_initiator)
315     {
316         p_mcb->is_disc_initiator = FALSE;
317         rfc_mx_sm_execute (p_mcb, RFC_MX_EVENT_CLOSE_REQ, NULL);
318     }
319     else
320         rfc_timer_start (p_mcb, RFC_MCB_RELEASE_INACT_TIMER);
321 }
322 
rfcomm_port_timer_timeout(void * data)323 void rfcomm_port_timer_timeout(void *data)
324 {
325     tPORT *p_port = (tPORT *)data;
326 
327     rfc_port_sm_execute(p_port, RFC_EVENT_TIMEOUT, NULL);
328 }
329 
rfcomm_mcb_timer_timeout(void * data)330 void rfcomm_mcb_timer_timeout(void *data)
331 {
332     tRFC_MCB *p_mcb = (tRFC_MCB *)data;
333 
334     rfc_mx_sm_execute(p_mcb, RFC_EVENT_TIMEOUT, NULL);
335 }
336 
337 /*******************************************************************************
338 **
339 ** Function         rfc_sec_check_complete
340 **
341 ** Description      The function called when Security Manager finishes
342 **                  verification of the service side connection
343 **
344 ** Returns          void
345 **
346 *******************************************************************************/
rfc_sec_check_complete(BD_ADDR bd_addr,tBT_TRANSPORT transport,void * p_ref_data,UINT8 res)347 void rfc_sec_check_complete (BD_ADDR bd_addr, tBT_TRANSPORT transport, void *p_ref_data, UINT8 res)
348 {
349     tPORT *p_port = (tPORT *)p_ref_data;
350     UNUSED(bd_addr);
351     UNUSED(transport);
352 
353     /* Verify that PORT is still waiting for Security to complete */
354     if (!p_port->in_use
355      || ((p_port->rfc.state != RFC_STATE_ORIG_WAIT_SEC_CHECK)
356       && (p_port->rfc.state != RFC_STATE_TERM_WAIT_SEC_CHECK)))
357         return;
358 
359     rfc_port_sm_execute ((tPORT *)p_ref_data, RFC_EVENT_SEC_COMPLETE, &res);
360 }
361 
362 
363 /*******************************************************************************
364 **
365 ** Function         rfc_port_closed
366 **
367 ** Description      The function is called when port is released based on the
368 **                  event received from the lower layer, typically L2CAP
369 **                  connection down, DISC, or DM frame.
370 **
371 ** Returns          void
372 **
373 *******************************************************************************/
rfc_port_closed(tPORT * p_port)374 void rfc_port_closed (tPORT *p_port)
375 {
376     tRFC_MCB *p_mcb = p_port->rfc.p_mcb;
377 
378     RFCOMM_TRACE_DEBUG ("rfc_port_closed");
379 
380     rfc_port_timer_stop (p_port);
381 
382     p_port->rfc.state = RFC_STATE_CLOSED;
383 
384     /* If multiplexer channel was up mark it as down */
385     if (p_mcb)
386     {
387         p_mcb->port_inx[p_port->dlci] = 0;
388 
389         /* If there are no more ports opened on this MCB release it */
390         rfc_check_mcb_active (p_mcb);
391     }
392 
393     /* Notify port that RFC connection is gone */
394     port_rfc_closed (p_port, PORT_CLOSED);
395 }
396 
397 /*******************************************************************************
398 **
399 ** Function         rfc_inc_credit
400 **
401 ** Description      The function is called when a credit is received in a UIH
402 **                  frame.  It increments the TX credit count, and if data
403 **                  flow had halted, it restarts it.
404 **
405 ** Returns          void
406 **
407 *******************************************************************************/
rfc_inc_credit(tPORT * p_port,UINT8 credit)408 void rfc_inc_credit (tPORT *p_port, UINT8 credit)
409 {
410     if (p_port->rfc.p_mcb->flow == PORT_FC_CREDIT)
411     {
412         p_port->credit_tx += credit;
413 
414         RFCOMM_TRACE_EVENT ("rfc_inc_credit:%d", p_port->credit_tx);
415 
416         if (p_port->tx.peer_fc == TRUE)
417             PORT_FlowInd(p_port->rfc.p_mcb, p_port->dlci, TRUE);
418     }
419 }
420 
421 /*******************************************************************************
422 **
423 ** Function         rfc_dec_credit
424 **
425 ** Description      The function is called when a UIH frame of user data is
426 **                  sent.  It decrements the credit count.  If credit count
427 **                  Reaches zero, peer_fc is set.
428 **
429 ** Returns          void
430 **
431 *******************************************************************************/
rfc_dec_credit(tPORT * p_port)432 void rfc_dec_credit (tPORT *p_port)
433 {
434     if (p_port->rfc.p_mcb->flow == PORT_FC_CREDIT)
435     {
436         if (p_port->credit_tx > 0)
437             p_port->credit_tx--;
438 
439         if (p_port->credit_tx == 0)
440             p_port->tx.peer_fc = TRUE;
441     }
442 }
443 
444 
445 /*******************************************************************************
446 **
447 ** Function         rfc_check_send_cmd
448 **
449 ** Description      This function is called to send an RFCOMM command message
450 **                  or to handle the RFCOMM command message queue.
451 **
452 ** Returns          void
453 **
454 *******************************************************************************/
rfc_check_send_cmd(tRFC_MCB * p_mcb,BT_HDR * p_buf)455 void rfc_check_send_cmd(tRFC_MCB *p_mcb, BT_HDR *p_buf)
456 {
457     /* if passed a buffer queue it */
458     if (p_buf != NULL) {
459         if (p_mcb->cmd_q == NULL) {
460             RFCOMM_TRACE_ERROR("%s: empty queue: p_mcb = %p p_mcb->lcid = %u cached p_mcb = %p",
461                                __func__, p_mcb, p_mcb->lcid,
462                                rfc_find_lcid_mcb(p_mcb->lcid));
463         }
464         fixed_queue_enqueue(p_mcb->cmd_q, p_buf);
465     }
466 
467     /* handle queue if L2CAP not congested */
468     while (p_mcb->l2cap_congested == FALSE) {
469         BT_HDR *p = (BT_HDR *)fixed_queue_try_dequeue(p_mcb->cmd_q);
470         if (p == NULL)
471             break;
472         L2CA_DataWrite(p_mcb->lcid, p);
473     }
474 }
475