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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 the main L2CAP entry points
22  *
23  ******************************************************************************/
24 
25 #define LOG_TAG "bt_l2c_main"
26 
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 
31 #include "bt_target.h"
32 #include "btm_int.h"
33 #include "btu.h"
34 #include "device/include/controller.h"
35 #include "bt_common.h"
36 #include "hcimsgs.h"
37 #include "l2c_api.h"
38 #include "l2c_int.h"
39 #include "l2cdefs.h"
40 #include "osi/include/log.h"
41 
42 
43 extern fixed_queue_t *btu_general_alarm_queue;
44 
45 /********************************************************************************/
46 /*              L O C A L    F U N C T I O N     P R O T O T Y P E S            */
47 /********************************************************************************/
48 static void process_l2cap_cmd (tL2C_LCB *p_lcb, UINT8 *p, UINT16 pkt_len);
49 
50 /********************************************************************************/
51 /*                 G L O B A L      L 2 C A P       D A T A                     */
52 /********************************************************************************/
53 #if L2C_DYNAMIC_MEMORY == FALSE
54 tL2C_CB l2cb;
55 #endif
56 
57 /*******************************************************************************
58 **
59 ** Function         l2c_rcv_acl_data
60 **
61 ** Description      This function is called from the HCI Interface when an ACL
62 **                  data packet is received.
63 **
64 ** Returns          void
65 **
66 *******************************************************************************/
l2c_rcv_acl_data(BT_HDR * p_msg)67 void l2c_rcv_acl_data (BT_HDR *p_msg)
68 {
69     UINT8       *p = (UINT8 *)(p_msg + 1) + p_msg->offset;
70     UINT16      handle, hci_len;
71     UINT8       pkt_type;
72     tL2C_LCB    *p_lcb;
73     tL2C_CCB    *p_ccb = NULL;
74     UINT16      l2cap_len, rcv_cid, psm;
75     UINT16      credit;
76 
77     /* Extract the handle */
78     STREAM_TO_UINT16 (handle, p);
79     pkt_type = HCID_GET_EVENT (handle);
80     handle   = HCID_GET_HANDLE (handle);
81 
82     /* Since the HCI Transport is putting segmented packets back together, we */
83     /* should never get a valid packet with the type set to "continuation"    */
84     if (pkt_type != L2CAP_PKT_CONTINUE)
85     {
86         /* Find the LCB based on the handle */
87         if ((p_lcb = l2cu_find_lcb_by_handle (handle)) == NULL)
88         {
89             UINT8       cmd_code;
90 
91             /* There is a slight possibility (specifically with USB) that we get an */
92             /* L2CAP connection request before we get the HCI connection complete.  */
93             /* So for these types of messages, hold them for up to 2 seconds.       */
94             STREAM_TO_UINT16 (hci_len, p);
95             STREAM_TO_UINT16 (l2cap_len, p);
96             STREAM_TO_UINT16 (rcv_cid, p);
97             STREAM_TO_UINT8  (cmd_code, p);
98 
99             if ((p_msg->layer_specific == 0) && (rcv_cid == L2CAP_SIGNALLING_CID)
100                     && (cmd_code == L2CAP_CMD_INFO_REQ || cmd_code == L2CAP_CMD_CONN_REQ)) {
101                 L2CAP_TRACE_WARNING ("L2CAP - holding ACL for unknown handle:%d ls:%d"
102                         "  cid:%d opcode:%d cur count:%d", handle, p_msg->layer_specific,
103                         rcv_cid, cmd_code, list_length(l2cb.rcv_pending_q));
104                 p_msg->layer_specific = 2;
105                 list_append(l2cb.rcv_pending_q, p_msg);
106 
107                 if (list_length(l2cb.rcv_pending_q) == 1) {
108                     alarm_set_on_queue(l2cb.receive_hold_timer,
109                                        BT_1SEC_TIMEOUT_MS,
110                                        l2c_receive_hold_timer_timeout, NULL,
111                                        btu_general_alarm_queue);
112                 }
113 
114                 return;
115             } else {
116                 L2CAP_TRACE_ERROR ("L2CAP - rcvd ACL for unknown handle:%d ls:%d cid:%d"
117                         " opcode:%d cur count:%d", handle, p_msg->layer_specific, rcv_cid,
118                         cmd_code, list_length(l2cb.rcv_pending_q));
119             }
120             osi_free(p_msg);
121             return;
122         }
123     }
124     else
125     {
126         L2CAP_TRACE_WARNING ("L2CAP - expected pkt start or complete, got: %d", pkt_type);
127         osi_free(p_msg);
128         return;
129     }
130 
131     /* Extract the length and update the buffer header */
132     STREAM_TO_UINT16 (hci_len, p);
133     p_msg->offset += 4;
134 
135     /* Extract the length and CID */
136     STREAM_TO_UINT16 (l2cap_len, p);
137     STREAM_TO_UINT16 (rcv_cid, p);
138 
139 #if BLE_INCLUDED == TRUE
140    /* for BLE channel, always notify connection when ACL data received on the link */
141    if (p_lcb && p_lcb->transport == BT_TRANSPORT_LE && p_lcb->link_state != LST_DISCONNECTING)
142       /* only process fixed channel data as channel open indication when link is not in disconnecting mode */
143         l2cble_notify_le_connection(p_lcb->remote_bd_addr);
144 #endif
145 
146     /* Find the CCB for this CID */
147     if (rcv_cid >= L2CAP_BASE_APPL_CID)
148     {
149         if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, rcv_cid)) == NULL)
150         {
151             L2CAP_TRACE_WARNING ("L2CAP - unknown CID: 0x%04x", rcv_cid);
152             osi_free(p_msg);
153             return;
154         }
155     }
156 
157     if (hci_len >= L2CAP_PKT_OVERHEAD)  /* Must receive at least the L2CAP length and CID.*/
158     {
159         p_msg->len    = hci_len - L2CAP_PKT_OVERHEAD;
160         p_msg->offset += L2CAP_PKT_OVERHEAD;
161     }
162     else
163     {
164         L2CAP_TRACE_WARNING ("L2CAP - got incorrect hci header" );
165         osi_free(p_msg);
166         return;
167     }
168 
169     if (l2cap_len != p_msg->len)
170     {
171         L2CAP_TRACE_WARNING ("L2CAP - bad length in pkt. Exp: %d  Act: %d",
172                               l2cap_len, p_msg->len);
173 
174         osi_free(p_msg);
175         return;
176     }
177 
178     /* Send the data through the channel state machine */
179     if (rcv_cid == L2CAP_SIGNALLING_CID)
180     {
181         process_l2cap_cmd (p_lcb, p, l2cap_len);
182         osi_free(p_msg);
183     }
184     else if (rcv_cid == L2CAP_CONNECTIONLESS_CID)
185     {
186         /* process_connectionless_data (p_lcb); */
187         STREAM_TO_UINT16 (psm, p);
188         L2CAP_TRACE_DEBUG( "GOT CONNECTIONLESS DATA PSM:%d", psm ) ;
189 
190 #if (L2CAP_UCD_INCLUDED == TRUE)
191         /* if it is not broadcast, check UCD registration */
192         if ( l2c_ucd_check_rx_pkts( p_lcb, p_msg ) )
193         {
194             /* nothing to do */
195         }
196         else
197 #endif
198             osi_free(p_msg);
199     }
200 #if (BLE_INCLUDED == TRUE)
201     else if (rcv_cid == L2CAP_BLE_SIGNALLING_CID)
202     {
203         l2cble_process_sig_cmd (p_lcb, p, l2cap_len);
204         osi_free(p_msg);
205     }
206 #endif
207 #if (L2CAP_NUM_FIXED_CHNLS > 0)
208     else if ((rcv_cid >= L2CAP_FIRST_FIXED_CHNL) && (rcv_cid <= L2CAP_LAST_FIXED_CHNL) &&
209              (l2cb.fixed_reg[rcv_cid - L2CAP_FIRST_FIXED_CHNL].pL2CA_FixedData_Cb != NULL) )
210     {
211         /* If no CCB for this channel, allocate one */
212         if (p_lcb &&
213             /* only process fixed channel data when link is open or wait for data indication */
214             (p_lcb->link_state != LST_DISCONNECTING) &&
215             l2cu_initialize_fixed_ccb (p_lcb, rcv_cid, &l2cb.fixed_reg[rcv_cid - L2CAP_FIRST_FIXED_CHNL].fixed_chnl_opts))
216         {
217             p_ccb = p_lcb->p_fixed_ccbs[rcv_cid - L2CAP_FIRST_FIXED_CHNL];
218 
219             if (p_ccb->peer_cfg.fcr.mode != L2CAP_FCR_BASIC_MODE)
220                 l2c_fcr_proc_pdu (p_ccb, p_msg);
221             else
222                 (*l2cb.fixed_reg[rcv_cid - L2CAP_FIRST_FIXED_CHNL].pL2CA_FixedData_Cb)
223                     (rcv_cid, p_lcb->remote_bd_addr, p_msg);
224         }
225         else
226             osi_free(p_msg);
227     }
228 #endif
229 
230     else
231     {
232         if (p_ccb == NULL)
233             osi_free(p_msg);
234         else
235         {
236             if (p_lcb->transport == BT_TRANSPORT_LE)
237             {
238                l2c_lcc_proc_pdu(p_ccb,p_msg);
239                // Got a pkt, valid send out credits to the peer device
240                credit = L2CAP_LE_DEFAULT_CREDIT;
241                l2c_csm_execute(p_ccb, L2CEVT_L2CA_SEND_FLOW_CONTROL_CREDIT, &credit);
242             }
243             else
244             {
245                 /* Basic mode packets go straight to the state machine */
246                 if (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_BASIC_MODE)
247                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_DATA, p_msg);
248                 else
249                 {
250                     /* eRTM or streaming mode, so we need to validate states first */
251                     if ((p_ccb->chnl_state == CST_OPEN) || (p_ccb->chnl_state == CST_CONFIG))
252                         l2c_fcr_proc_pdu (p_ccb, p_msg);
253                     else
254                         osi_free (p_msg);
255                 }
256             }
257         }
258     }
259 }
260 
261 /*******************************************************************************
262 **
263 ** Function         process_l2cap_cmd
264 **
265 ** Description      This function is called when a packet is received on the
266 **                  L2CAP signalling CID
267 **
268 ** Returns          void
269 **
270 *******************************************************************************/
process_l2cap_cmd(tL2C_LCB * p_lcb,UINT8 * p,UINT16 pkt_len)271 static void process_l2cap_cmd (tL2C_LCB *p_lcb, UINT8 *p, UINT16 pkt_len)
272 {
273     UINT8           *p_pkt_end, *p_next_cmd, *p_cfg_end, *p_cfg_start;
274     UINT8           cmd_code, cfg_code, cfg_len, id;
275     tL2C_CONN_INFO  con_info;
276     tL2CAP_CFG_INFO cfg_info;
277     UINT16          rej_reason, rej_mtu, lcid, rcid, info_type;
278     tL2C_CCB        *p_ccb;
279     tL2C_RCB        *p_rcb;
280     BOOLEAN         cfg_rej, pkt_size_rej = FALSE;
281     UINT16          cfg_rej_len, cmd_len;
282     UINT16          result;
283     tL2C_CONN_INFO  ci;
284 
285 #if (defined BLE_INCLUDED && BLE_INCLUDED == TRUE)
286     /* if l2cap command received in CID 1 on top of an LE link, ignore this command */
287     if (p_lcb->transport == BT_TRANSPORT_LE)
288         return;
289 #endif
290 
291     /* Reject the packet if it exceeds the default Signalling Channel MTU */
292     if (pkt_len > L2CAP_DEFAULT_MTU)
293     {
294         /* Core Spec requires a single response to the first command found in a multi-command
295         ** L2cap packet.  If only responses in the packet, then it will be ignored.
296         ** Here we simply mark the bad packet and decide which cmd ID to reject later
297         */
298         pkt_size_rej = TRUE;
299         L2CAP_TRACE_ERROR ("L2CAP SIG MTU Pkt Len Exceeded (672) -> pkt_len: %d", pkt_len);
300     }
301 
302     p_next_cmd = p;
303     p_pkt_end  = p + pkt_len;
304 
305     memset (&cfg_info, 0, sizeof(cfg_info));
306 
307     /* An L2CAP packet may contain multiple commands */
308     while (TRUE)
309     {
310         /* Smallest command is 4 bytes */
311         if ((p = p_next_cmd) > (p_pkt_end - 4))
312             break;
313 
314         STREAM_TO_UINT8  (cmd_code, p);
315         STREAM_TO_UINT8  (id, p);
316         STREAM_TO_UINT16 (cmd_len, p);
317 
318         /* Check command length does not exceed packet length */
319         if ((p_next_cmd = p + cmd_len) > p_pkt_end)
320         {
321             L2CAP_TRACE_WARNING ("Command len bad  pkt_len: %d  cmd_len: %d  code: %d",
322                                   pkt_len, cmd_len, cmd_code);
323             break;
324         }
325 
326         L2CAP_TRACE_DEBUG ("cmd_code: %d, id:%d, cmd_len:%d", cmd_code, id, cmd_len);
327 
328         /* Bad L2CAP packet length, look or cmd to reject */
329         if (pkt_size_rej)
330         {
331             /* If command found rejected it and we're done, otherwise keep looking */
332             if (l2c_is_cmd_rejected(cmd_code, id, p_lcb))
333                 return;
334             else
335                 continue; /* Look for next cmd/response in current packet */
336         }
337 
338         switch (cmd_code)
339         {
340         case L2CAP_CMD_REJECT:
341             STREAM_TO_UINT16 (rej_reason, p);
342             if (rej_reason == L2CAP_CMD_REJ_MTU_EXCEEDED)
343             {
344                 STREAM_TO_UINT16 (rej_mtu, p);
345                 /* What to do with the MTU reject ? We have negotiated an MTU. For now */
346                 /* we will ignore it and let a higher protocol timeout take care of it */
347 
348                 L2CAP_TRACE_WARNING ("L2CAP - MTU rej Handle: %d MTU: %d", p_lcb->handle, rej_mtu);
349             }
350             if (rej_reason == L2CAP_CMD_REJ_INVALID_CID)
351             {
352                 STREAM_TO_UINT16 (rcid, p);
353                 STREAM_TO_UINT16 (lcid, p);
354 
355                 L2CAP_TRACE_WARNING ("L2CAP - rej with CID invalid, LCID: 0x%04x RCID: 0x%04x", lcid, rcid);
356 
357                 /* Remote CID invalid. Treat as a disconnect */
358                 if (((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) != NULL)
359                  && (p_ccb->remote_cid == rcid))
360                 {
361                     /* Fake link disconnect - no reply is generated */
362                     l2c_csm_execute (p_ccb, L2CEVT_LP_DISCONNECT_IND, NULL);
363                 }
364             }
365 
366             /* SonyEricsson Info request Bug workaround (Continue connection) */
367             else if (rej_reason == L2CAP_CMD_REJ_NOT_UNDERSTOOD && p_lcb->w4_info_rsp)
368             {
369                 alarm_cancel(p_lcb->info_resp_timer);
370 
371                 p_lcb->w4_info_rsp = FALSE;
372                 ci.status = HCI_SUCCESS;
373                 memcpy (ci.bd_addr, p_lcb->remote_bd_addr, sizeof(BD_ADDR));
374 
375                 /* For all channels, send the event through their FSMs */
376                 for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; p_ccb = p_ccb->p_next_ccb)
377                 {
378                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_INFO_RSP, &ci);
379                 }
380             }
381             break;
382 
383         case L2CAP_CMD_CONN_REQ:
384             STREAM_TO_UINT16 (con_info.psm, p);
385             STREAM_TO_UINT16 (rcid, p);
386             if ((p_rcb = l2cu_find_rcb_by_psm (con_info.psm)) == NULL)
387             {
388                 L2CAP_TRACE_WARNING ("L2CAP - rcvd conn req for unknown PSM: %d", con_info.psm);
389                 l2cu_reject_connection (p_lcb, rcid, id, L2CAP_CONN_NO_PSM);
390                 break;
391             }
392             else
393             {
394                 if (!p_rcb->api.pL2CA_ConnectInd_Cb)
395                 {
396                     L2CAP_TRACE_WARNING ("L2CAP - rcvd conn req for outgoing-only connection PSM: %d", con_info.psm);
397                     l2cu_reject_connection (p_lcb, rcid, id, L2CAP_CONN_NO_PSM);
398                     break;
399                 }
400             }
401             if ((p_ccb = l2cu_allocate_ccb (p_lcb, 0)) == NULL)
402             {
403                 L2CAP_TRACE_ERROR ("L2CAP - unable to allocate CCB");
404                 l2cu_reject_connection (p_lcb, rcid, id, L2CAP_CONN_NO_RESOURCES);
405                 break;
406             }
407             p_ccb->remote_id = id;
408             p_ccb->p_rcb = p_rcb;
409             p_ccb->remote_cid = rcid;
410 
411             l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONNECT_REQ, &con_info);
412             break;
413 
414         case L2CAP_CMD_CONN_RSP:
415             STREAM_TO_UINT16 (con_info.remote_cid, p);
416             STREAM_TO_UINT16 (lcid, p);
417             STREAM_TO_UINT16 (con_info.l2cap_result, p);
418             STREAM_TO_UINT16 (con_info.l2cap_status, p);
419 
420             if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) == NULL)
421             {
422                 L2CAP_TRACE_WARNING ("L2CAP - no CCB for conn rsp, LCID: %d RCID: %d",
423                                       lcid, con_info.remote_cid);
424                 break;
425             }
426             if (p_ccb->local_id != id)
427             {
428                 L2CAP_TRACE_WARNING ("L2CAP - con rsp - bad ID. Exp: %d Got: %d",
429                                       p_ccb->local_id, id);
430                 break;
431             }
432 
433             if (con_info.l2cap_result == L2CAP_CONN_OK)
434                 l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONNECT_RSP, &con_info);
435             else if (con_info.l2cap_result == L2CAP_CONN_PENDING)
436                 l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONNECT_RSP_PND, &con_info);
437             else
438                 l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONNECT_RSP_NEG, &con_info);
439 
440             break;
441 
442         case L2CAP_CMD_CONFIG_REQ:
443             p_cfg_end = p + cmd_len;
444             cfg_rej = FALSE;
445             cfg_rej_len = 0;
446 
447             STREAM_TO_UINT16 (lcid, p);
448             STREAM_TO_UINT16 (cfg_info.flags, p);
449 
450             p_cfg_start = p;
451 
452             cfg_info.flush_to_present = cfg_info.mtu_present = cfg_info.qos_present =
453                 cfg_info.fcr_present = cfg_info.fcs_present = FALSE;
454 
455             while (p < p_cfg_end)
456             {
457                 STREAM_TO_UINT8 (cfg_code, p);
458                 STREAM_TO_UINT8 (cfg_len, p);
459 
460                 switch (cfg_code & 0x7F)
461                 {
462                 case L2CAP_CFG_TYPE_MTU:
463                     cfg_info.mtu_present = TRUE;
464                     STREAM_TO_UINT16 (cfg_info.mtu, p);
465                     break;
466 
467                 case L2CAP_CFG_TYPE_FLUSH_TOUT:
468                     cfg_info.flush_to_present = TRUE;
469                     STREAM_TO_UINT16 (cfg_info.flush_to, p);
470                     break;
471 
472                 case L2CAP_CFG_TYPE_QOS:
473                     cfg_info.qos_present = TRUE;
474                     STREAM_TO_UINT8  (cfg_info.qos.qos_flags, p);
475                     STREAM_TO_UINT8  (cfg_info.qos.service_type, p);
476                     STREAM_TO_UINT32 (cfg_info.qos.token_rate, p);
477                     STREAM_TO_UINT32 (cfg_info.qos.token_bucket_size, p);
478                     STREAM_TO_UINT32 (cfg_info.qos.peak_bandwidth, p);
479                     STREAM_TO_UINT32 (cfg_info.qos.latency, p);
480                     STREAM_TO_UINT32 (cfg_info.qos.delay_variation, p);
481                     break;
482 
483                 case L2CAP_CFG_TYPE_FCR:
484                     cfg_info.fcr_present = TRUE;
485                     STREAM_TO_UINT8 (cfg_info.fcr.mode, p);
486                     STREAM_TO_UINT8 (cfg_info.fcr.tx_win_sz, p);
487                     STREAM_TO_UINT8 (cfg_info.fcr.max_transmit, p);
488                     STREAM_TO_UINT16 (cfg_info.fcr.rtrans_tout, p);
489                     STREAM_TO_UINT16 (cfg_info.fcr.mon_tout, p);
490                     STREAM_TO_UINT16 (cfg_info.fcr.mps, p);
491                     break;
492 
493                 case L2CAP_CFG_TYPE_FCS:
494                     cfg_info.fcs_present = TRUE;
495                     STREAM_TO_UINT8 (cfg_info.fcs, p);
496                     break;
497 
498                 case L2CAP_CFG_TYPE_EXT_FLOW:
499                     cfg_info.ext_flow_spec_present = TRUE;
500                     STREAM_TO_UINT8  (cfg_info.ext_flow_spec.id, p);
501                     STREAM_TO_UINT8  (cfg_info.ext_flow_spec.stype, p);
502                     STREAM_TO_UINT16 (cfg_info.ext_flow_spec.max_sdu_size, p);
503                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.sdu_inter_time, p);
504                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.access_latency, p);
505                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.flush_timeout, p);
506                     break;
507 
508                 default:
509                     /* sanity check option length */
510                     if ((cfg_len + L2CAP_CFG_OPTION_OVERHEAD) <= cmd_len)
511                     {
512                         p += cfg_len;
513                         if ((cfg_code & 0x80) == 0)
514                         {
515                             cfg_rej_len += cfg_len + L2CAP_CFG_OPTION_OVERHEAD;
516                             cfg_rej = TRUE;
517                         }
518                     }
519                     /* bad length; force loop exit */
520                     else
521                     {
522                         p = p_cfg_end;
523                         cfg_rej = TRUE;
524                     }
525                     break;
526                 }
527             }
528 
529             if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) != NULL)
530             {
531                 p_ccb->remote_id = id;
532                 if (cfg_rej)
533                 {
534                     l2cu_send_peer_config_rej (p_ccb, p_cfg_start, (UINT16) (cmd_len - L2CAP_CONFIG_REQ_LEN), cfg_rej_len);
535                 }
536                 else
537                 {
538                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_CONFIG_REQ, &cfg_info);
539                 }
540             }
541             else
542             {
543                 /* updated spec says send command reject on invalid cid */
544                 l2cu_send_peer_cmd_reject (p_lcb, L2CAP_CMD_REJ_INVALID_CID, id, 0, 0);
545             }
546             break;
547 
548         case L2CAP_CMD_CONFIG_RSP:
549             p_cfg_end = p + cmd_len;
550             STREAM_TO_UINT16 (lcid, p);
551             STREAM_TO_UINT16 (cfg_info.flags, p);
552             STREAM_TO_UINT16 (cfg_info.result, p);
553 
554             cfg_info.flush_to_present = cfg_info.mtu_present = cfg_info.qos_present =
555                 cfg_info.fcr_present = cfg_info.fcs_present = FALSE;
556 
557             while (p < p_cfg_end)
558             {
559                 STREAM_TO_UINT8 (cfg_code, p);
560                 STREAM_TO_UINT8 (cfg_len, p);
561 
562                 switch (cfg_code & 0x7F)
563                 {
564                 case L2CAP_CFG_TYPE_MTU:
565                     cfg_info.mtu_present = TRUE;
566                     STREAM_TO_UINT16 (cfg_info.mtu, p);
567                     break;
568 
569                 case L2CAP_CFG_TYPE_FLUSH_TOUT:
570                     cfg_info.flush_to_present = TRUE;
571                     STREAM_TO_UINT16 (cfg_info.flush_to, p);
572                     break;
573 
574                 case L2CAP_CFG_TYPE_QOS:
575                     cfg_info.qos_present = TRUE;
576                     STREAM_TO_UINT8  (cfg_info.qos.qos_flags, p);
577                     STREAM_TO_UINT8  (cfg_info.qos.service_type, p);
578                     STREAM_TO_UINT32 (cfg_info.qos.token_rate, p);
579                     STREAM_TO_UINT32 (cfg_info.qos.token_bucket_size, p);
580                     STREAM_TO_UINT32 (cfg_info.qos.peak_bandwidth, p);
581                     STREAM_TO_UINT32 (cfg_info.qos.latency, p);
582                     STREAM_TO_UINT32 (cfg_info.qos.delay_variation, p);
583                     break;
584 
585                 case L2CAP_CFG_TYPE_FCR:
586                     cfg_info.fcr_present = TRUE;
587                     STREAM_TO_UINT8 (cfg_info.fcr.mode, p);
588                     STREAM_TO_UINT8 (cfg_info.fcr.tx_win_sz, p);
589                     STREAM_TO_UINT8 (cfg_info.fcr.max_transmit, p);
590                     STREAM_TO_UINT16 (cfg_info.fcr.rtrans_tout, p);
591                     STREAM_TO_UINT16 (cfg_info.fcr.mon_tout, p);
592                     STREAM_TO_UINT16 (cfg_info.fcr.mps, p);
593                     break;
594 
595                 case L2CAP_CFG_TYPE_FCS:
596                     cfg_info.fcs_present = TRUE;
597                     STREAM_TO_UINT8 (cfg_info.fcs, p);
598                     break;
599 
600                 case L2CAP_CFG_TYPE_EXT_FLOW:
601                     cfg_info.ext_flow_spec_present = TRUE;
602                     STREAM_TO_UINT8  (cfg_info.ext_flow_spec.id, p);
603                     STREAM_TO_UINT8  (cfg_info.ext_flow_spec.stype, p);
604                     STREAM_TO_UINT16 (cfg_info.ext_flow_spec.max_sdu_size, p);
605                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.sdu_inter_time, p);
606                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.access_latency, p);
607                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.flush_timeout, p);
608                     break;
609                 }
610             }
611 
612             if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) != NULL)
613             {
614                 if (p_ccb->local_id != id)
615                 {
616                     L2CAP_TRACE_WARNING ("L2CAP - cfg rsp - bad ID. Exp: %d Got: %d",
617                                           p_ccb->local_id, id);
618                     break;
619                 }
620                 if ( (cfg_info.result == L2CAP_CFG_OK) || (cfg_info.result == L2CAP_CFG_PENDING) )
621                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_CONFIG_RSP, &cfg_info);
622                 else
623                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_CONFIG_RSP_NEG, &cfg_info);
624             }
625             else
626             {
627                 L2CAP_TRACE_WARNING ("L2CAP - rcvd cfg rsp for unknown CID: 0x%04x", lcid);
628             }
629             break;
630 
631         case L2CAP_CMD_DISC_REQ:
632             STREAM_TO_UINT16 (lcid, p);
633             STREAM_TO_UINT16 (rcid, p);
634 
635             if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) != NULL)
636             {
637                 if (p_ccb->remote_cid == rcid)
638                 {
639                     p_ccb->remote_id = id;
640                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_DISCONNECT_REQ, &con_info);
641                 }
642             }
643             else
644                 l2cu_send_peer_disc_rsp (p_lcb, id, lcid, rcid);
645 
646             break;
647 
648         case L2CAP_CMD_DISC_RSP:
649             STREAM_TO_UINT16 (rcid, p);
650             STREAM_TO_UINT16 (lcid, p);
651 
652             if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) != NULL)
653             {
654                 if ((p_ccb->remote_cid == rcid) && (p_ccb->local_id == id))
655                 {
656                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_DISCONNECT_RSP, &con_info);
657                 }
658             }
659             break;
660 
661         case L2CAP_CMD_ECHO_REQ:
662             l2cu_send_peer_echo_rsp (p_lcb, id, NULL, 0);
663             break;
664 
665         case L2CAP_CMD_ECHO_RSP:
666             if (p_lcb->p_echo_rsp_cb)
667             {
668                 tL2CA_ECHO_RSP_CB *p_cb = p_lcb->p_echo_rsp_cb;
669 
670                 /* Zero out the callback in case app immediately calls us again */
671                 p_lcb->p_echo_rsp_cb = NULL;
672 
673                 (*p_cb) (L2CAP_PING_RESULT_OK);
674             }
675             break;
676 
677         case L2CAP_CMD_INFO_REQ:
678             STREAM_TO_UINT16 (info_type, p);
679             l2cu_send_peer_info_rsp (p_lcb, id, info_type);
680             break;
681 
682         case L2CAP_CMD_INFO_RSP:
683             /* Stop the link connect timer if sent before L2CAP connection is up */
684             if (p_lcb->w4_info_rsp)
685             {
686                 alarm_cancel(p_lcb->info_resp_timer);
687                 p_lcb->w4_info_rsp = FALSE;
688             }
689 
690             STREAM_TO_UINT16 (info_type, p);
691             STREAM_TO_UINT16 (result, p);
692 
693             p_lcb->info_rx_bits |= (1 << info_type);
694 
695             if ( (info_type == L2CAP_EXTENDED_FEATURES_INFO_TYPE)
696               && (result == L2CAP_INFO_RESP_RESULT_SUCCESS) )
697             {
698                 STREAM_TO_UINT32( p_lcb->peer_ext_fea, p );
699 
700 #if (L2CAP_NUM_FIXED_CHNLS > 0)
701                 if (p_lcb->peer_ext_fea & L2CAP_EXTFEA_FIXED_CHNLS)
702                 {
703                     l2cu_send_peer_info_req (p_lcb, L2CAP_FIXED_CHANNELS_INFO_TYPE);
704                     break;
705                 }
706                 else
707                 {
708                     l2cu_process_fixed_chnl_resp (p_lcb);
709                 }
710 #endif
711             }
712 
713 #if (L2CAP_NUM_FIXED_CHNLS > 0)
714             if (info_type == L2CAP_FIXED_CHANNELS_INFO_TYPE)
715             {
716                 if (result == L2CAP_INFO_RESP_RESULT_SUCCESS)
717                 {
718                     memcpy (p_lcb->peer_chnl_mask, p, L2CAP_FIXED_CHNL_ARRAY_SIZE);
719                 }
720 
721                 l2cu_process_fixed_chnl_resp (p_lcb);
722             }
723 #endif
724 #if (L2CAP_UCD_INCLUDED == TRUE)
725             else if (info_type == L2CAP_CONNLESS_MTU_INFO_TYPE)
726             {
727                 if (result == L2CAP_INFO_RESP_RESULT_SUCCESS)
728                 {
729                     STREAM_TO_UINT16 (p_lcb->ucd_mtu, p);
730                 }
731             }
732 #endif
733 
734             ci.status = HCI_SUCCESS;
735             memcpy (ci.bd_addr, p_lcb->remote_bd_addr, sizeof(BD_ADDR));
736             for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; p_ccb = p_ccb->p_next_ccb)
737             {
738                 l2c_csm_execute (p_ccb, L2CEVT_L2CAP_INFO_RSP, &ci);
739             }
740             break;
741 
742         default:
743             L2CAP_TRACE_WARNING ("L2CAP - bad cmd code: %d", cmd_code);
744             l2cu_send_peer_cmd_reject (p_lcb, L2CAP_CMD_REJ_NOT_UNDERSTOOD, id, 0, 0);
745             return;
746         }
747     }
748 }
749 
750 /*******************************************************************************
751 **
752 ** Function         l2c_process_held_packets
753 **
754 ** Description      This function processes any L2CAP packets that arrived before
755 **                  the HCI connection complete arrived. It is a work around for
756 **                  badly behaved controllers.
757 **
758 ** Returns          void
759 **
760 *******************************************************************************/
l2c_process_held_packets(BOOLEAN timed_out)761 void l2c_process_held_packets(BOOLEAN timed_out) {
762     if (list_is_empty(l2cb.rcv_pending_q))
763         return;
764 
765     if (!timed_out) {
766         alarm_cancel(l2cb.receive_hold_timer);
767         L2CAP_TRACE_WARNING("L2CAP HOLD CONTINUE");
768     } else {
769         L2CAP_TRACE_WARNING("L2CAP HOLD TIMEOUT");
770     }
771 
772     for (const list_node_t *node = list_begin(l2cb.rcv_pending_q);
773         node != list_end(l2cb.rcv_pending_q);)  {
774         BT_HDR *p_buf = list_node(node);
775         node = list_next(node);
776         if (!timed_out || (!p_buf->layer_specific) || (--p_buf->layer_specific == 0)) {
777             list_remove(l2cb.rcv_pending_q, p_buf);
778             p_buf->layer_specific = 0xFFFF;
779             l2c_rcv_acl_data(p_buf);
780         }
781     }
782 
783     /* If anyone still in the queue, restart the timeout */
784     if (!list_is_empty(l2cb.rcv_pending_q)) {
785         alarm_set_on_queue(l2cb.receive_hold_timer, BT_1SEC_TIMEOUT_MS,
786                            l2c_receive_hold_timer_timeout, NULL,
787                            btu_general_alarm_queue);
788     }
789 }
790 
791 /*******************************************************************************
792 **
793 ** Function         l2c_init
794 **
795 ** Description      This function is called once at startup to initialize
796 **                  all the L2CAP structures
797 **
798 ** Returns          void
799 **
800 *******************************************************************************/
l2c_init(void)801 void l2c_init (void)
802 {
803     INT16  xx;
804 
805     memset (&l2cb, 0, sizeof (tL2C_CB));
806     /* the psm is increased by 2 before being used */
807     l2cb.dyn_psm = 0xFFF;
808 
809     /* Put all the channel control blocks on the free queue */
810     for (xx = 0; xx < MAX_L2CAP_CHANNELS - 1; xx++)
811     {
812         l2cb.ccb_pool[xx].p_next_ccb = &l2cb.ccb_pool[xx + 1];
813     }
814 
815 #if (L2CAP_NON_FLUSHABLE_PB_INCLUDED == TRUE)
816     /* it will be set to L2CAP_PKT_START_NON_FLUSHABLE if controller supports */
817     l2cb.non_flushable_pbf = L2CAP_PKT_START << L2CAP_PKT_TYPE_SHIFT;
818 #endif
819 
820     l2cb.p_free_ccb_first = &l2cb.ccb_pool[0];
821     l2cb.p_free_ccb_last  = &l2cb.ccb_pool[MAX_L2CAP_CHANNELS - 1];
822 
823 #ifdef L2CAP_DESIRED_LINK_ROLE
824     l2cb.desire_role      = L2CAP_DESIRED_LINK_ROLE;
825 #else
826     l2cb.desire_role      = HCI_ROLE_SLAVE;
827 #endif
828 
829     /* Set the default idle timeout */
830     l2cb.idle_timeout = L2CAP_LINK_INACTIVITY_TOUT;
831 
832 #if defined(L2CAP_INITIAL_TRACE_LEVEL)
833     l2cb.l2cap_trace_level = L2CAP_INITIAL_TRACE_LEVEL;
834 #else
835     l2cb.l2cap_trace_level = BT_TRACE_LEVEL_NONE;    /* No traces */
836 #endif
837 
838 #if L2CAP_CONFORMANCE_TESTING == TRUE
839      /* Conformance testing needs a dynamic response */
840     l2cb.test_info_resp = L2CAP_EXTFEA_SUPPORTED_MASK;
841 #endif
842 
843     /* Number of ACL buffers to use for high priority channel */
844 #if (defined(L2CAP_HIGH_PRI_CHAN_QUOTA_IS_CONFIGURABLE) && (L2CAP_HIGH_PRI_CHAN_QUOTA_IS_CONFIGURABLE == TRUE))
845     l2cb.high_pri_min_xmit_quota = L2CAP_HIGH_PRI_MIN_XMIT_QUOTA;
846 #endif
847 
848 #if BLE_INCLUDED == TRUE
849     l2cb.l2c_ble_fixed_chnls_mask =
850          L2CAP_FIXED_CHNL_ATT_BIT | L2CAP_FIXED_CHNL_BLE_SIG_BIT | L2CAP_FIXED_CHNL_SMP_BIT;
851 #endif
852 
853     l2cb.rcv_pending_q = list_new(NULL);
854     if (l2cb.rcv_pending_q == NULL)
855         LOG_ERROR(LOG_TAG, "%s unable to allocate memory for link layer control block", __func__);
856     l2cb.receive_hold_timer = alarm_new("l2c.receive_hold_timer");
857 }
858 
l2c_free(void)859 void l2c_free(void) {
860     list_free(l2cb.rcv_pending_q);
861     l2cb.rcv_pending_q = NULL;
862 }
863 
l2c_receive_hold_timer_timeout(UNUSED_ATTR void * data)864 void l2c_receive_hold_timer_timeout(UNUSED_ATTR void *data)
865 {
866     /* Update the timeouts in the hold queue */
867     l2c_process_held_packets(TRUE);
868 }
869 
l2c_ccb_timer_timeout(void * data)870 void l2c_ccb_timer_timeout(void *data)
871 {
872     tL2C_CCB *p_ccb = (tL2C_CCB *)data;
873 
874     l2c_csm_execute(p_ccb, L2CEVT_TIMEOUT, NULL);
875 }
876 
l2c_fcrb_ack_timer_timeout(void * data)877 void l2c_fcrb_ack_timer_timeout(void *data)
878 {
879     tL2C_CCB *p_ccb = (tL2C_CCB *)data;
880 
881     l2c_csm_execute(p_ccb, L2CEVT_ACK_TIMEOUT, NULL);
882 }
883 
l2c_lcb_timer_timeout(void * data)884 void l2c_lcb_timer_timeout(void *data)
885 {
886     tL2C_LCB *p_lcb = (tL2C_LCB *)data;
887 
888     l2c_link_timeout(p_lcb);
889 }
890 
891 /*******************************************************************************
892 **
893 ** Function         l2c_data_write
894 **
895 ** Description      API functions call this function to write data.
896 **
897 ** Returns          L2CAP_DW_SUCCESS, if data accepted, else FALSE
898 **                  L2CAP_DW_CONGESTED, if data accepted and the channel is congested
899 **                  L2CAP_DW_FAILED, if error
900 **
901 *******************************************************************************/
l2c_data_write(UINT16 cid,BT_HDR * p_data,UINT16 flags)902 UINT8 l2c_data_write (UINT16 cid, BT_HDR *p_data, UINT16 flags)
903 {
904     tL2C_CCB        *p_ccb;
905 
906     /* Find the channel control block. We don't know the link it is on. */
907     if ((p_ccb = l2cu_find_ccb_by_cid (NULL, cid)) == NULL)
908     {
909         L2CAP_TRACE_WARNING ("L2CAP - no CCB for L2CA_DataWrite, CID: %d", cid);
910         osi_free(p_data);
911         return (L2CAP_DW_FAILED);
912     }
913 
914 #ifndef TESTER /* Tester may send any amount of data. otherwise sending message
915                   bigger than mtu size of peer is a violation of protocol */
916     UINT16 mtu;
917 
918     if (p_ccb->p_lcb->transport == BT_TRANSPORT_LE)
919         mtu = p_ccb->peer_conn_cfg.mtu;
920     else
921         mtu = p_ccb->peer_cfg.mtu;
922 
923     if (p_data->len > mtu)
924     {
925         L2CAP_TRACE_WARNING ("L2CAP - CID: 0x%04x  cannot send message bigger than peer's mtu size", cid);
926         osi_free(p_data);
927         return (L2CAP_DW_FAILED);
928     }
929 #endif
930 
931     /* channel based, packet based flushable or non-flushable */
932     p_data->layer_specific = flags;
933 
934     /* If already congested, do not accept any more packets */
935     if (p_ccb->cong_sent)
936     {
937         L2CAP_TRACE_ERROR ("L2CAP - CID: 0x%04x cannot send, already congested  xmit_hold_q.count: %u  buff_quota: %u",
938                            p_ccb->local_cid,
939                            fixed_queue_length(p_ccb->xmit_hold_q),
940                            p_ccb->buff_quota);
941 
942         osi_free(p_data);
943         return (L2CAP_DW_FAILED);
944     }
945 
946 
947     l2c_csm_execute (p_ccb, L2CEVT_L2CA_DATA_WRITE, p_data);
948 
949     if (p_ccb->cong_sent)
950         return (L2CAP_DW_CONGESTED);
951 
952     return (L2CAP_DW_SUCCESS);
953 }
954 
955