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 #include <stdlib.h>
26 #include <string.h>
27 #include <stdio.h>
28 
29 #include "device/include/controller.h"
30 #include "btcore/include/counter.h"
31 #include "bt_target.h"
32 #include "btm_int.h"
33 #include "btu.h"
34 #include "gki.h"
35 #include "hcimsgs.h"
36 #include "l2c_api.h"
37 #include "l2c_int.h"
38 #include "l2cdefs.h"
39 #include "osi/include/log.h"
40 
41 /********************************************************************************/
42 /*              L O C A L    F U N C T I O N     P R O T O T Y P E S            */
43 /********************************************************************************/
44 static void process_l2cap_cmd (tL2C_LCB *p_lcb, UINT8 *p, UINT16 pkt_len);
45 
46 /********************************************************************************/
47 /*                 G L O B A L      L 2 C A P       D A T A                     */
48 /********************************************************************************/
49 #if L2C_DYNAMIC_MEMORY == FALSE
50 tL2C_CB l2cb;
51 #endif
52 
53 /*******************************************************************************
54 **
55 ** Function         l2c_bcst_msg
56 **
57 ** Description
58 **
59 ** Returns          void
60 **
61 *******************************************************************************/
l2c_bcst_msg(BT_HDR * p_buf,UINT16 psm)62 void l2c_bcst_msg( BT_HDR *p_buf, UINT16 psm )
63 {
64     UINT8       *p;
65 
66     /* Ensure we have enough space in the buffer for the L2CAP and HCI headers */
67     if (p_buf->offset < L2CAP_BCST_MIN_OFFSET)
68     {
69         L2CAP_TRACE_ERROR ("L2CAP - cannot send buffer, offset: %d", p_buf->offset);
70         GKI_freebuf (p_buf);
71         return;
72     }
73 
74     /* Step back some bytes to add the headers */
75     p_buf->offset -= (HCI_DATA_PREAMBLE_SIZE + L2CAP_PKT_OVERHEAD + L2CAP_BCST_OVERHEAD);
76     p_buf->len    += L2CAP_PKT_OVERHEAD + L2CAP_BCST_OVERHEAD;
77 
78     /* Set the pointer to the beginning of the data */
79     p = (UINT8 *)(p_buf + 1) + p_buf->offset;
80 
81     /* First, the HCI transport header */
82     UINT16_TO_STREAM (p, 0x0050 | (L2CAP_PKT_START << 12) | (2 << 14));
83 
84     uint16_t acl_data_size = controller_get_interface()->get_acl_data_size_classic();
85     /* The HCI transport will segment the buffers. */
86     if (p_buf->len > acl_data_size)
87     {
88         UINT16_TO_STREAM (p, acl_data_size);
89     }
90     else
91     {
92         UINT16_TO_STREAM (p, p_buf->len);
93     }
94 
95     /* Now the L2CAP header */
96     UINT16_TO_STREAM (p, p_buf->len - L2CAP_PKT_OVERHEAD);
97     UINT16_TO_STREAM (p, L2CAP_CONNECTIONLESS_CID);
98     UINT16_TO_STREAM (p, psm);
99 
100     p_buf->len += HCI_DATA_PREAMBLE_SIZE;
101 
102     if (p_buf->len <= controller_get_interface()->get_acl_packet_size_classic())
103     {
104         counter_add("l2cap.ch2.tx.bytes", p_buf->len);
105         counter_add("l2cap.ch2.tx.pkts", 1);
106 
107         bte_main_hci_send(p_buf, BT_EVT_TO_LM_HCI_ACL);
108     }
109 }
110 
111 
112 /*******************************************************************************
113 **
114 ** Function         l2c_rcv_acl_data
115 **
116 ** Description      This function is called from the HCI Interface when an ACL
117 **                  data packet is received.
118 **
119 ** Returns          void
120 **
121 *******************************************************************************/
l2c_rcv_acl_data(BT_HDR * p_msg)122 void l2c_rcv_acl_data (BT_HDR *p_msg)
123 {
124     UINT8       *p = (UINT8 *)(p_msg + 1) + p_msg->offset;
125     UINT16      handle, hci_len;
126     UINT8       pkt_type;
127     tL2C_LCB    *p_lcb;
128     tL2C_CCB    *p_ccb = NULL;
129     UINT16      l2cap_len, rcv_cid, psm;
130 
131     /* Extract the handle */
132     STREAM_TO_UINT16 (handle, p);
133     pkt_type = HCID_GET_EVENT (handle);
134     handle   = HCID_GET_HANDLE (handle);
135 
136     /* Since the HCI Transport is putting segmented packets back together, we */
137     /* should never get a valid packet with the type set to "continuation"    */
138     if (pkt_type != L2CAP_PKT_CONTINUE)
139     {
140         /* Find the LCB based on the handle */
141         if ((p_lcb = l2cu_find_lcb_by_handle (handle)) == NULL)
142         {
143             UINT8       cmd_code;
144 
145             /* There is a slight possibility (specifically with USB) that we get an */
146             /* L2CAP connection request before we get the HCI connection complete.  */
147             /* So for these types of messages, hold them for up to 2 seconds.       */
148             STREAM_TO_UINT16 (hci_len, p);
149             STREAM_TO_UINT16 (l2cap_len, p);
150             STREAM_TO_UINT16 (rcv_cid, p);
151             STREAM_TO_UINT8  (cmd_code, p);
152 
153             if ((p_msg->layer_specific == 0) && (rcv_cid == L2CAP_SIGNALLING_CID)
154                     && (cmd_code == L2CAP_CMD_INFO_REQ || cmd_code == L2CAP_CMD_CONN_REQ)) {
155                 L2CAP_TRACE_WARNING ("L2CAP - holding ACL for unknown handle:%d ls:%d"
156                         "  cid:%d opcode:%d cur count:%d", handle, p_msg->layer_specific,
157                         rcv_cid, cmd_code, list_length(l2cb.rcv_pending_q));
158                 p_msg->layer_specific = 2;
159                 list_append(l2cb.rcv_pending_q, p_msg);
160 
161                 if (list_length(l2cb.rcv_pending_q) == 1)
162                     btu_start_timer (&l2cb.rcv_hold_tle, BTU_TTYPE_L2CAP_HOLD, BT_1SEC_TIMEOUT);
163 
164                 return;
165             } else {
166                 L2CAP_TRACE_ERROR ("L2CAP - rcvd ACL for unknown handle:%d ls:%d cid:%d"
167                         " opcode:%d cur count:%d", handle, p_msg->layer_specific, rcv_cid,
168                         cmd_code, list_length(l2cb.rcv_pending_q));
169             }
170             GKI_freebuf (p_msg);
171             return;
172         }
173     }
174     else
175     {
176         L2CAP_TRACE_WARNING ("L2CAP - expected pkt start or complete, got: %d", pkt_type);
177         GKI_freebuf (p_msg);
178         return;
179     }
180 
181     /* Extract the length and update the buffer header */
182     STREAM_TO_UINT16 (hci_len, p);
183     p_msg->offset += 4;
184 
185     /* Extract the length and CID */
186     STREAM_TO_UINT16 (l2cap_len, p);
187     STREAM_TO_UINT16 (rcv_cid, p);
188 
189 #if BLE_INCLUDED == TRUE
190    /* for BLE channel, always notify connection when ACL data received on the link */
191    if (p_lcb && p_lcb->transport == BT_TRANSPORT_LE && p_lcb->link_state != LST_DISCONNECTING)
192       /* only process fixed channel data as channel open indication when link is not in disconnecting mode */
193         l2cble_notify_le_connection(p_lcb->remote_bd_addr);
194 #endif
195 
196     /* Find the CCB for this CID */
197     if (rcv_cid >= L2CAP_BASE_APPL_CID)
198     {
199         if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, rcv_cid)) == NULL)
200         {
201             L2CAP_TRACE_WARNING ("L2CAP - unknown CID: 0x%04x", rcv_cid);
202             GKI_freebuf (p_msg);
203             return;
204         }
205     }
206 
207     if (hci_len >= L2CAP_PKT_OVERHEAD)  /* Must receive at least the L2CAP length and CID.*/
208     {
209         p_msg->len    = hci_len - L2CAP_PKT_OVERHEAD;
210         p_msg->offset += L2CAP_PKT_OVERHEAD;
211     }
212     else
213     {
214         L2CAP_TRACE_WARNING ("L2CAP - got incorrect hci header" );
215         GKI_freebuf (p_msg);
216         return;
217     }
218 
219     if (l2cap_len != p_msg->len)
220     {
221         L2CAP_TRACE_WARNING ("L2CAP - bad length in pkt. Exp: %d  Act: %d",
222                               l2cap_len, p_msg->len);
223 
224         GKI_freebuf (p_msg);
225         return;
226     }
227 
228     /* Send the data through the channel state machine */
229     if (rcv_cid == L2CAP_SIGNALLING_CID)
230     {
231         counter_add("l2cap.sig.rx.bytes", l2cap_len);
232         counter_add("l2cap.sig.rx.pkts", 1);
233         process_l2cap_cmd (p_lcb, p, l2cap_len);
234         GKI_freebuf (p_msg);
235     }
236     else if (rcv_cid == L2CAP_CONNECTIONLESS_CID)
237     {
238         counter_add("l2cap.ch2.rx.bytes", l2cap_len);
239         counter_add("l2cap.ch2.rx.pkts", 1);
240         /* process_connectionless_data (p_lcb); */
241         STREAM_TO_UINT16 (psm, p);
242         L2CAP_TRACE_DEBUG( "GOT CONNECTIONLESS DATA PSM:%d", psm ) ;
243 
244 #if (L2CAP_UCD_INCLUDED == TRUE)
245         /* if it is not broadcast, check UCD registration */
246         if ( l2c_ucd_check_rx_pkts( p_lcb, p_msg ) )
247         {
248             /* nothing to do */
249         }
250         else
251 #endif
252             GKI_freebuf (p_msg);
253     }
254 #if (BLE_INCLUDED == TRUE)
255     else if (rcv_cid == L2CAP_BLE_SIGNALLING_CID)
256     {
257         counter_add("l2cap.ble.rx.bytes", l2cap_len);
258         counter_add("l2cap.ble.rx.pkts", 1);
259         l2cble_process_sig_cmd (p_lcb, p, l2cap_len);
260         GKI_freebuf (p_msg);
261     }
262 #endif
263 #if (L2CAP_NUM_FIXED_CHNLS > 0)
264     else if ((rcv_cid >= L2CAP_FIRST_FIXED_CHNL) && (rcv_cid <= L2CAP_LAST_FIXED_CHNL) &&
265              (l2cb.fixed_reg[rcv_cid - L2CAP_FIRST_FIXED_CHNL].pL2CA_FixedData_Cb != NULL) )
266     {
267         counter_add("l2cap.fix.rx.bytes", l2cap_len);
268         counter_add("l2cap.fix.rx.pkts", 1);
269         /* If no CCB for this channel, allocate one */
270         if (p_lcb &&
271             /* only process fixed channel data when link is open or wait for data indication */
272             (p_lcb->link_state != LST_DISCONNECTING) &&
273             l2cu_initialize_fixed_ccb (p_lcb, rcv_cid, &l2cb.fixed_reg[rcv_cid - L2CAP_FIRST_FIXED_CHNL].fixed_chnl_opts))
274         {
275             p_ccb = p_lcb->p_fixed_ccbs[rcv_cid - L2CAP_FIRST_FIXED_CHNL];
276 
277             if (p_ccb->peer_cfg.fcr.mode != L2CAP_FCR_BASIC_MODE)
278                 l2c_fcr_proc_pdu (p_ccb, p_msg);
279             else
280                 (*l2cb.fixed_reg[rcv_cid - L2CAP_FIRST_FIXED_CHNL].pL2CA_FixedData_Cb)
281                     (rcv_cid, p_lcb->remote_bd_addr, p_msg);
282         }
283         else
284             GKI_freebuf (p_msg);
285     }
286 #endif
287 
288     else
289     {
290         counter_add("l2cap.dyn.rx.bytes", l2cap_len);
291         counter_add("l2cap.dyn.rx.pkts", 1);
292         if (p_ccb == NULL)
293             GKI_freebuf (p_msg);
294         else
295         {
296             /* Basic mode packets go straight to the state machine */
297             if (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_BASIC_MODE)
298                 l2c_csm_execute (p_ccb, L2CEVT_L2CAP_DATA, p_msg);
299             else
300             {
301                 /* eRTM or streaming mode, so we need to validate states first */
302                 if ((p_ccb->chnl_state == CST_OPEN) || (p_ccb->chnl_state == CST_CONFIG))
303                     l2c_fcr_proc_pdu (p_ccb, p_msg);
304                 else
305                     GKI_freebuf (p_msg);
306             }
307         }
308     }
309 }
310 
311 /*******************************************************************************
312 **
313 ** Function         process_l2cap_cmd
314 **
315 ** Description      This function is called when a packet is received on the
316 **                  L2CAP signalling CID
317 **
318 ** Returns          void
319 **
320 *******************************************************************************/
process_l2cap_cmd(tL2C_LCB * p_lcb,UINT8 * p,UINT16 pkt_len)321 static void process_l2cap_cmd (tL2C_LCB *p_lcb, UINT8 *p, UINT16 pkt_len)
322 {
323     UINT8           *p_pkt_end, *p_next_cmd, *p_cfg_end, *p_cfg_start;
324     UINT8           cmd_code, cfg_code, cfg_len, id;
325     tL2C_CONN_INFO  con_info;
326     tL2CAP_CFG_INFO cfg_info;
327     UINT16          rej_reason, rej_mtu, lcid, rcid, info_type;
328     tL2C_CCB        *p_ccb;
329     tL2C_RCB        *p_rcb;
330     BOOLEAN         cfg_rej, pkt_size_rej = FALSE;
331     UINT16          cfg_rej_len, cmd_len;
332     UINT16          result;
333     tL2C_CONN_INFO  ci;
334 
335 #if (defined BLE_INCLUDED && BLE_INCLUDED == TRUE)
336     /* if l2cap command received in CID 1 on top of an LE link, ignore this command */
337     if (p_lcb->transport == BT_TRANSPORT_LE)
338         return;
339 #endif
340 
341     /* Reject the packet if it exceeds the default Signalling Channel MTU */
342     if (pkt_len > L2CAP_DEFAULT_MTU)
343     {
344         /* Core Spec requires a single response to the first command found in a multi-command
345         ** L2cap packet.  If only responses in the packet, then it will be ignored.
346         ** Here we simply mark the bad packet and decide which cmd ID to reject later
347         */
348         pkt_size_rej = TRUE;
349         L2CAP_TRACE_ERROR ("L2CAP SIG MTU Pkt Len Exceeded (672) -> pkt_len: %d", pkt_len);
350     }
351 
352     p_next_cmd = p;
353     p_pkt_end  = p + pkt_len;
354 
355     memset (&cfg_info, 0, sizeof(cfg_info));
356 
357     /* An L2CAP packet may contain multiple commands */
358     while (TRUE)
359     {
360         /* Smallest command is 4 bytes */
361         if ((p = p_next_cmd) > (p_pkt_end - 4))
362             break;
363 
364         STREAM_TO_UINT8  (cmd_code, p);
365         STREAM_TO_UINT8  (id, p);
366         STREAM_TO_UINT16 (cmd_len, p);
367 
368         /* Check command length does not exceed packet length */
369         if ((p_next_cmd = p + cmd_len) > p_pkt_end)
370         {
371             L2CAP_TRACE_WARNING ("Command len bad  pkt_len: %d  cmd_len: %d  code: %d",
372                                   pkt_len, cmd_len, cmd_code);
373             break;
374         }
375 
376         L2CAP_TRACE_DEBUG ("cmd_code: %d, id:%d, cmd_len:%d", cmd_code, id, cmd_len);
377 
378         /* Bad L2CAP packet length, look or cmd to reject */
379         if (pkt_size_rej)
380         {
381             /* If command found rejected it and we're done, otherwise keep looking */
382             if (l2c_is_cmd_rejected(cmd_code, id, p_lcb))
383                 return;
384             else
385                 continue; /* Look for next cmd/response in current packet */
386         }
387 
388         switch (cmd_code)
389         {
390         case L2CAP_CMD_REJECT:
391             STREAM_TO_UINT16 (rej_reason, p);
392             if (rej_reason == L2CAP_CMD_REJ_MTU_EXCEEDED)
393             {
394                 STREAM_TO_UINT16 (rej_mtu, p);
395                 /* What to do with the MTU reject ? We have negotiated an MTU. For now */
396                 /* we will ignore it and let a higher protocol timeout take care of it */
397 
398                 L2CAP_TRACE_WARNING ("L2CAP - MTU rej Handle: %d MTU: %d", p_lcb->handle, rej_mtu);
399             }
400             if (rej_reason == L2CAP_CMD_REJ_INVALID_CID)
401             {
402                 STREAM_TO_UINT16 (rcid, p);
403                 STREAM_TO_UINT16 (lcid, p);
404 
405                 L2CAP_TRACE_WARNING ("L2CAP - rej with CID invalid, LCID: 0x%04x RCID: 0x%04x", lcid, rcid);
406 
407                 /* Remote CID invalid. Treat as a disconnect */
408                 if (((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) != NULL)
409                  && (p_ccb->remote_cid == rcid))
410                 {
411                     /* Fake link disconnect - no reply is generated */
412                     l2c_csm_execute (p_ccb, L2CEVT_LP_DISCONNECT_IND, NULL);
413                 }
414             }
415 
416             /* SonyEricsson Info request Bug workaround (Continue connection) */
417             else if (rej_reason == L2CAP_CMD_REJ_NOT_UNDERSTOOD && p_lcb->w4_info_rsp)
418             {
419                 btu_stop_timer (&p_lcb->info_timer_entry);
420 
421                 p_lcb->w4_info_rsp = FALSE;
422                 ci.status = HCI_SUCCESS;
423                 memcpy (ci.bd_addr, p_lcb->remote_bd_addr, sizeof(BD_ADDR));
424 
425                 /* For all channels, send the event through their FSMs */
426                 for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; p_ccb = p_ccb->p_next_ccb)
427                 {
428                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_INFO_RSP, &ci);
429                 }
430             }
431             break;
432 
433         case L2CAP_CMD_CONN_REQ:
434             STREAM_TO_UINT16 (con_info.psm, p);
435             STREAM_TO_UINT16 (rcid, p);
436             if ((p_rcb = l2cu_find_rcb_by_psm (con_info.psm)) == NULL)
437             {
438                 L2CAP_TRACE_WARNING ("L2CAP - rcvd conn req for unknown PSM: %d", con_info.psm);
439                 l2cu_reject_connection (p_lcb, rcid, id, L2CAP_CONN_NO_PSM);
440                 break;
441             }
442             else
443             {
444                 if (!p_rcb->api.pL2CA_ConnectInd_Cb)
445                 {
446                     L2CAP_TRACE_WARNING ("L2CAP - rcvd conn req for outgoing-only connection PSM: %d", con_info.psm);
447                     l2cu_reject_connection (p_lcb, rcid, id, L2CAP_CONN_NO_PSM);
448                     break;
449                 }
450             }
451             if ((p_ccb = l2cu_allocate_ccb (p_lcb, 0)) == NULL)
452             {
453                 L2CAP_TRACE_ERROR ("L2CAP - unable to allocate CCB");
454                 l2cu_reject_connection (p_lcb, rcid, id, L2CAP_CONN_NO_RESOURCES);
455                 break;
456             }
457             p_ccb->remote_id = id;
458             p_ccb->p_rcb = p_rcb;
459             p_ccb->remote_cid = rcid;
460 
461             l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONNECT_REQ, &con_info);
462             break;
463 
464         case L2CAP_CMD_CONN_RSP:
465             STREAM_TO_UINT16 (con_info.remote_cid, p);
466             STREAM_TO_UINT16 (lcid, p);
467             STREAM_TO_UINT16 (con_info.l2cap_result, p);
468             STREAM_TO_UINT16 (con_info.l2cap_status, p);
469 
470             if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) == NULL)
471             {
472                 L2CAP_TRACE_WARNING ("L2CAP - no CCB for conn rsp, LCID: %d RCID: %d",
473                                       lcid, con_info.remote_cid);
474                 break;
475             }
476             if (p_ccb->local_id != id)
477             {
478                 L2CAP_TRACE_WARNING ("L2CAP - con rsp - bad ID. Exp: %d Got: %d",
479                                       p_ccb->local_id, id);
480                 break;
481             }
482 
483             if (con_info.l2cap_result == L2CAP_CONN_OK)
484                 l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONNECT_RSP, &con_info);
485             else if (con_info.l2cap_result == L2CAP_CONN_PENDING)
486                 l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONNECT_RSP_PND, &con_info);
487             else
488                 l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONNECT_RSP_NEG, &con_info);
489 
490             break;
491 
492         case L2CAP_CMD_CONFIG_REQ:
493             p_cfg_end = p + cmd_len;
494             cfg_rej = FALSE;
495             cfg_rej_len = 0;
496 
497             STREAM_TO_UINT16 (lcid, p);
498             STREAM_TO_UINT16 (cfg_info.flags, p);
499 
500             p_cfg_start = p;
501 
502             cfg_info.flush_to_present = cfg_info.mtu_present = cfg_info.qos_present =
503                 cfg_info.fcr_present = cfg_info.fcs_present = FALSE;
504 
505             while (p < p_cfg_end)
506             {
507                 STREAM_TO_UINT8 (cfg_code, p);
508                 STREAM_TO_UINT8 (cfg_len, p);
509 
510                 switch (cfg_code & 0x7F)
511                 {
512                 case L2CAP_CFG_TYPE_MTU:
513                     cfg_info.mtu_present = TRUE;
514                     STREAM_TO_UINT16 (cfg_info.mtu, p);
515                     break;
516 
517                 case L2CAP_CFG_TYPE_FLUSH_TOUT:
518                     cfg_info.flush_to_present = TRUE;
519                     STREAM_TO_UINT16 (cfg_info.flush_to, p);
520                     break;
521 
522                 case L2CAP_CFG_TYPE_QOS:
523                     cfg_info.qos_present = TRUE;
524                     STREAM_TO_UINT8  (cfg_info.qos.qos_flags, p);
525                     STREAM_TO_UINT8  (cfg_info.qos.service_type, p);
526                     STREAM_TO_UINT32 (cfg_info.qos.token_rate, p);
527                     STREAM_TO_UINT32 (cfg_info.qos.token_bucket_size, p);
528                     STREAM_TO_UINT32 (cfg_info.qos.peak_bandwidth, p);
529                     STREAM_TO_UINT32 (cfg_info.qos.latency, p);
530                     STREAM_TO_UINT32 (cfg_info.qos.delay_variation, p);
531                     break;
532 
533                 case L2CAP_CFG_TYPE_FCR:
534                     cfg_info.fcr_present = TRUE;
535                     STREAM_TO_UINT8 (cfg_info.fcr.mode, p);
536                     STREAM_TO_UINT8 (cfg_info.fcr.tx_win_sz, p);
537                     STREAM_TO_UINT8 (cfg_info.fcr.max_transmit, p);
538                     STREAM_TO_UINT16 (cfg_info.fcr.rtrans_tout, p);
539                     STREAM_TO_UINT16 (cfg_info.fcr.mon_tout, p);
540                     STREAM_TO_UINT16 (cfg_info.fcr.mps, p);
541                     break;
542 
543                 case L2CAP_CFG_TYPE_FCS:
544                     cfg_info.fcs_present = TRUE;
545                     STREAM_TO_UINT8 (cfg_info.fcs, p);
546                     break;
547 
548                 case L2CAP_CFG_TYPE_EXT_FLOW:
549                     cfg_info.ext_flow_spec_present = TRUE;
550                     STREAM_TO_UINT8  (cfg_info.ext_flow_spec.id, p);
551                     STREAM_TO_UINT8  (cfg_info.ext_flow_spec.stype, p);
552                     STREAM_TO_UINT16 (cfg_info.ext_flow_spec.max_sdu_size, p);
553                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.sdu_inter_time, p);
554                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.access_latency, p);
555                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.flush_timeout, p);
556                     break;
557 
558                 default:
559                     /* sanity check option length */
560                     if ((cfg_len + L2CAP_CFG_OPTION_OVERHEAD) <= cmd_len)
561                     {
562                         p += cfg_len;
563                         if ((cfg_code & 0x80) == 0)
564                         {
565                             cfg_rej_len += cfg_len + L2CAP_CFG_OPTION_OVERHEAD;
566                             cfg_rej = TRUE;
567                         }
568                     }
569                     /* bad length; force loop exit */
570                     else
571                     {
572                         p = p_cfg_end;
573                         cfg_rej = TRUE;
574                     }
575                     break;
576                 }
577             }
578 
579             if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) != NULL)
580             {
581                 p_ccb->remote_id = id;
582                 if (cfg_rej)
583                 {
584                     l2cu_send_peer_config_rej (p_ccb, p_cfg_start, (UINT16) (cmd_len - L2CAP_CONFIG_REQ_LEN), cfg_rej_len);
585                 }
586                 else
587                 {
588                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_CONFIG_REQ, &cfg_info);
589                 }
590             }
591             else
592             {
593                 /* updated spec says send command reject on invalid cid */
594                 l2cu_send_peer_cmd_reject (p_lcb, L2CAP_CMD_REJ_INVALID_CID, id, 0, 0);
595             }
596             break;
597 
598         case L2CAP_CMD_CONFIG_RSP:
599             p_cfg_end = p + cmd_len;
600             STREAM_TO_UINT16 (lcid, p);
601             STREAM_TO_UINT16 (cfg_info.flags, p);
602             STREAM_TO_UINT16 (cfg_info.result, p);
603 
604             cfg_info.flush_to_present = cfg_info.mtu_present = cfg_info.qos_present =
605                 cfg_info.fcr_present = cfg_info.fcs_present = FALSE;
606 
607             while (p < p_cfg_end)
608             {
609                 STREAM_TO_UINT8 (cfg_code, p);
610                 STREAM_TO_UINT8 (cfg_len, p);
611 
612                 switch (cfg_code & 0x7F)
613                 {
614                 case L2CAP_CFG_TYPE_MTU:
615                     cfg_info.mtu_present = TRUE;
616                     STREAM_TO_UINT16 (cfg_info.mtu, p);
617                     break;
618 
619                 case L2CAP_CFG_TYPE_FLUSH_TOUT:
620                     cfg_info.flush_to_present = TRUE;
621                     STREAM_TO_UINT16 (cfg_info.flush_to, p);
622                     break;
623 
624                 case L2CAP_CFG_TYPE_QOS:
625                     cfg_info.qos_present = TRUE;
626                     STREAM_TO_UINT8  (cfg_info.qos.qos_flags, p);
627                     STREAM_TO_UINT8  (cfg_info.qos.service_type, p);
628                     STREAM_TO_UINT32 (cfg_info.qos.token_rate, p);
629                     STREAM_TO_UINT32 (cfg_info.qos.token_bucket_size, p);
630                     STREAM_TO_UINT32 (cfg_info.qos.peak_bandwidth, p);
631                     STREAM_TO_UINT32 (cfg_info.qos.latency, p);
632                     STREAM_TO_UINT32 (cfg_info.qos.delay_variation, p);
633                     break;
634 
635                 case L2CAP_CFG_TYPE_FCR:
636                     cfg_info.fcr_present = TRUE;
637                     STREAM_TO_UINT8 (cfg_info.fcr.mode, p);
638                     STREAM_TO_UINT8 (cfg_info.fcr.tx_win_sz, p);
639                     STREAM_TO_UINT8 (cfg_info.fcr.max_transmit, p);
640                     STREAM_TO_UINT16 (cfg_info.fcr.rtrans_tout, p);
641                     STREAM_TO_UINT16 (cfg_info.fcr.mon_tout, p);
642                     STREAM_TO_UINT16 (cfg_info.fcr.mps, p);
643                     break;
644 
645                 case L2CAP_CFG_TYPE_FCS:
646                     cfg_info.fcs_present = TRUE;
647                     STREAM_TO_UINT8 (cfg_info.fcs, p);
648                     break;
649 
650                 case L2CAP_CFG_TYPE_EXT_FLOW:
651                     cfg_info.ext_flow_spec_present = TRUE;
652                     STREAM_TO_UINT8  (cfg_info.ext_flow_spec.id, p);
653                     STREAM_TO_UINT8  (cfg_info.ext_flow_spec.stype, p);
654                     STREAM_TO_UINT16 (cfg_info.ext_flow_spec.max_sdu_size, p);
655                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.sdu_inter_time, p);
656                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.access_latency, p);
657                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.flush_timeout, p);
658                     break;
659                 }
660             }
661 
662             if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) != NULL)
663             {
664                 if (p_ccb->local_id != id)
665                 {
666                     L2CAP_TRACE_WARNING ("L2CAP - cfg rsp - bad ID. Exp: %d Got: %d",
667                                           p_ccb->local_id, id);
668                     break;
669                 }
670                 if ( (cfg_info.result == L2CAP_CFG_OK) || (cfg_info.result == L2CAP_CFG_PENDING) )
671                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_CONFIG_RSP, &cfg_info);
672                 else
673                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_CONFIG_RSP_NEG, &cfg_info);
674             }
675             else
676             {
677                 L2CAP_TRACE_WARNING ("L2CAP - rcvd cfg rsp for unknown CID: 0x%04x", lcid);
678             }
679             break;
680 
681 
682         case L2CAP_CMD_DISC_REQ:
683             STREAM_TO_UINT16 (lcid, p);
684             STREAM_TO_UINT16 (rcid, p);
685 
686             if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) != NULL)
687             {
688                 if (p_ccb->remote_cid == rcid)
689                 {
690                     p_ccb->remote_id = id;
691                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_DISCONNECT_REQ, &con_info);
692                 }
693             }
694             else
695                 l2cu_send_peer_disc_rsp (p_lcb, id, lcid, rcid);
696 
697             break;
698 
699         case L2CAP_CMD_DISC_RSP:
700             STREAM_TO_UINT16 (rcid, p);
701             STREAM_TO_UINT16 (lcid, p);
702 
703             if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) != NULL)
704             {
705                 if ((p_ccb->remote_cid == rcid) && (p_ccb->local_id == id))
706                 {
707                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_DISCONNECT_RSP, &con_info);
708                 }
709             }
710             break;
711 
712         case L2CAP_CMD_ECHO_REQ:
713             l2cu_send_peer_echo_rsp (p_lcb, id, NULL, 0);
714             break;
715 
716         case L2CAP_CMD_ECHO_RSP:
717             if (p_lcb->p_echo_rsp_cb)
718             {
719                 tL2CA_ECHO_RSP_CB *p_cb = p_lcb->p_echo_rsp_cb;
720 
721                 /* Zero out the callback in case app immediately calls us again */
722                 p_lcb->p_echo_rsp_cb = NULL;
723 
724                 (*p_cb) (L2CAP_PING_RESULT_OK);
725             }
726             break;
727 
728         case L2CAP_CMD_INFO_REQ:
729             STREAM_TO_UINT16 (info_type, p);
730             l2cu_send_peer_info_rsp (p_lcb, id, info_type);
731             break;
732 
733         case L2CAP_CMD_INFO_RSP:
734             /* Stop the link connect timer if sent before L2CAP connection is up */
735             if (p_lcb->w4_info_rsp)
736             {
737                 btu_stop_timer (&p_lcb->info_timer_entry);
738                 p_lcb->w4_info_rsp = FALSE;
739             }
740 
741             STREAM_TO_UINT16 (info_type, p);
742             STREAM_TO_UINT16 (result, p);
743 
744             p_lcb->info_rx_bits |= (1 << info_type);
745 
746             if ( (info_type == L2CAP_EXTENDED_FEATURES_INFO_TYPE)
747               && (result == L2CAP_INFO_RESP_RESULT_SUCCESS) )
748             {
749                 STREAM_TO_UINT32( p_lcb->peer_ext_fea, p );
750 
751 #if (L2CAP_NUM_FIXED_CHNLS > 0)
752                 if (p_lcb->peer_ext_fea & L2CAP_EXTFEA_FIXED_CHNLS)
753                 {
754                     l2cu_send_peer_info_req (p_lcb, L2CAP_FIXED_CHANNELS_INFO_TYPE);
755                     break;
756                 }
757                 else
758                 {
759                     l2cu_process_fixed_chnl_resp (p_lcb);
760                 }
761 #endif
762             }
763 
764 
765 #if (L2CAP_NUM_FIXED_CHNLS > 0)
766             if (info_type == L2CAP_FIXED_CHANNELS_INFO_TYPE)
767             {
768                 if (result == L2CAP_INFO_RESP_RESULT_SUCCESS)
769                 {
770                     memcpy (p_lcb->peer_chnl_mask, p, L2CAP_FIXED_CHNL_ARRAY_SIZE);
771                 }
772 
773                 l2cu_process_fixed_chnl_resp (p_lcb);
774             }
775 #endif
776 #if (L2CAP_UCD_INCLUDED == TRUE)
777             else if (info_type == L2CAP_CONNLESS_MTU_INFO_TYPE)
778             {
779                 if (result == L2CAP_INFO_RESP_RESULT_SUCCESS)
780                 {
781                     STREAM_TO_UINT16 (p_lcb->ucd_mtu, p);
782                 }
783             }
784 #endif
785 
786             ci.status = HCI_SUCCESS;
787             memcpy (ci.bd_addr, p_lcb->remote_bd_addr, sizeof(BD_ADDR));
788             for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; p_ccb = p_ccb->p_next_ccb)
789             {
790                 l2c_csm_execute (p_ccb, L2CEVT_L2CAP_INFO_RSP, &ci);
791             }
792             break;
793 
794         default:
795             L2CAP_TRACE_WARNING ("L2CAP - bad cmd code: %d", cmd_code);
796             l2cu_send_peer_cmd_reject (p_lcb, L2CAP_CMD_REJ_NOT_UNDERSTOOD, id, 0, 0);
797             return;
798         }
799     }
800 }
801 
802 /*******************************************************************************
803 **
804 ** Function         l2c_process_held_packets
805 **
806 ** Description      This function processes any L2CAP packets that arrived before
807 **                  the HCI connection complete arrived. It is a work around for
808 **                  badly behaved controllers.
809 **
810 ** Returns          void
811 **
812 *******************************************************************************/
l2c_process_held_packets(BOOLEAN timed_out)813 void l2c_process_held_packets(BOOLEAN timed_out) {
814     if (list_is_empty(l2cb.rcv_pending_q))
815         return;
816 
817     if (!timed_out) {
818         btu_stop_timer(&l2cb.rcv_hold_tle);
819         L2CAP_TRACE_WARNING("L2CAP HOLD CONTINUE");
820     } else {
821         L2CAP_TRACE_WARNING("L2CAP HOLD TIMEOUT");
822     }
823 
824     for (const list_node_t *node = list_begin(l2cb.rcv_pending_q);
825         node != list_end(l2cb.rcv_pending_q);)  {
826         BT_HDR *p_buf = list_node(node);
827         node = list_next(node);
828         if (!timed_out || (!p_buf->layer_specific) || (--p_buf->layer_specific == 0)) {
829             list_remove(l2cb.rcv_pending_q, p_buf);
830             p_buf->layer_specific = 0xFFFF;
831             l2c_rcv_acl_data(p_buf);
832         }
833     }
834 
835     /* If anyone still in the queue, restart the timeout */
836     if (!list_is_empty(l2cb.rcv_pending_q))
837         btu_start_timer (&l2cb.rcv_hold_tle, BTU_TTYPE_L2CAP_HOLD, BT_1SEC_TIMEOUT);
838 }
839 
840 
841 /*******************************************************************************
842 **
843 ** Function         l2c_init
844 **
845 ** Description      This function is called once at startup to initialize
846 **                  all the L2CAP structures
847 **
848 ** Returns          void
849 **
850 *******************************************************************************/
l2c_init(void)851 void l2c_init (void)
852 {
853     INT16  xx;
854 
855     memset (&l2cb, 0, sizeof (tL2C_CB));
856     /* the psm is increased by 2 before being used */
857     l2cb.dyn_psm = 0xFFF;
858 
859     /* Put all the channel control blocks on the free queue */
860     for (xx = 0; xx < MAX_L2CAP_CHANNELS - 1; xx++)
861     {
862         l2cb.ccb_pool[xx].p_next_ccb = &l2cb.ccb_pool[xx + 1];
863     }
864 
865 #if (L2CAP_NON_FLUSHABLE_PB_INCLUDED == TRUE)
866     /* it will be set to L2CAP_PKT_START_NON_FLUSHABLE if controller supports */
867     l2cb.non_flushable_pbf = L2CAP_PKT_START << L2CAP_PKT_TYPE_SHIFT;
868 #endif
869 
870 
871     l2cb.p_free_ccb_first = &l2cb.ccb_pool[0];
872     l2cb.p_free_ccb_last  = &l2cb.ccb_pool[MAX_L2CAP_CHANNELS - 1];
873 
874 #ifdef L2CAP_DESIRED_LINK_ROLE
875     l2cb.desire_role      = L2CAP_DESIRED_LINK_ROLE;
876 #else
877     l2cb.desire_role      = HCI_ROLE_SLAVE;
878 #endif
879 
880     /* Set the default idle timeout */
881     l2cb.idle_timeout = L2CAP_LINK_INACTIVITY_TOUT;
882 
883 #if defined(L2CAP_INITIAL_TRACE_LEVEL)
884     l2cb.l2cap_trace_level = L2CAP_INITIAL_TRACE_LEVEL;
885 #else
886     l2cb.l2cap_trace_level = BT_TRACE_LEVEL_NONE;    /* No traces */
887 #endif
888 
889 #if L2CAP_CONFORMANCE_TESTING == TRUE
890      /* Conformance testing needs a dynamic response */
891     l2cb.test_info_resp = L2CAP_EXTFEA_SUPPORTED_MASK;
892 #endif
893 
894     /* Number of ACL buffers to use for high priority channel */
895 #if (defined(L2CAP_HIGH_PRI_CHAN_QUOTA_IS_CONFIGURABLE) && (L2CAP_HIGH_PRI_CHAN_QUOTA_IS_CONFIGURABLE == TRUE))
896     l2cb.high_pri_min_xmit_quota = L2CAP_HIGH_PRI_MIN_XMIT_QUOTA;
897 #endif
898 
899 #if BLE_INCLUDED == TRUE
900     l2cb.l2c_ble_fixed_chnls_mask =
901          L2CAP_FIXED_CHNL_ATT_BIT | L2CAP_FIXED_CHNL_BLE_SIG_BIT | L2CAP_FIXED_CHNL_SMP_BIT;
902 #endif
903 
904     l2cb.rcv_pending_q = list_new(NULL);
905     if (l2cb.rcv_pending_q == NULL)
906         LOG_ERROR("%s unable to allocate memory for link layer control block", __func__);
907 }
908 
l2c_free(void)909 void l2c_free(void) {
910     list_free(l2cb.rcv_pending_q);
911 }
912 
913 /*******************************************************************************
914 **
915 ** Function         l2c_process_timeout
916 **
917 ** Description      This function is called when an L2CAP-related timeout occurs
918 **
919 ** Returns          void
920 **
921 *******************************************************************************/
l2c_process_timeout(TIMER_LIST_ENT * p_tle)922 void l2c_process_timeout (TIMER_LIST_ENT *p_tle)
923 {
924     /* What type of timeout ? */
925     switch (p_tle->event)
926     {
927     case BTU_TTYPE_L2CAP_LINK:
928         l2c_link_timeout ((tL2C_LCB *)p_tle->param);
929         break;
930 
931     case BTU_TTYPE_L2CAP_CHNL:
932         l2c_csm_execute (((tL2C_CCB *)p_tle->param), L2CEVT_TIMEOUT, NULL);
933         break;
934 
935     case BTU_TTYPE_L2CAP_FCR_ACK:
936         l2c_csm_execute (((tL2C_CCB *)p_tle->param), L2CEVT_ACK_TIMEOUT, NULL);
937         break;
938 
939     case BTU_TTYPE_L2CAP_HOLD:
940         /* Update the timeouts in the hold queue */
941         l2c_process_held_packets(TRUE);
942         break;
943 
944     case BTU_TTYPE_L2CAP_INFO:
945         l2c_info_timeout((tL2C_LCB *)p_tle->param);
946         break;
947     }
948 }
949 
950 /*******************************************************************************
951 **
952 ** Function         l2c_data_write
953 **
954 ** Description      API functions call this function to write data.
955 **
956 ** Returns          L2CAP_DW_SUCCESS, if data accepted, else FALSE
957 **                  L2CAP_DW_CONGESTED, if data accepted and the channel is congested
958 **                  L2CAP_DW_FAILED, if error
959 **
960 *******************************************************************************/
l2c_data_write(UINT16 cid,BT_HDR * p_data,UINT16 flags)961 UINT8 l2c_data_write (UINT16 cid, BT_HDR *p_data, UINT16 flags)
962 {
963     tL2C_CCB        *p_ccb;
964 
965     /* Find the channel control block. We don't know the link it is on. */
966     if ((p_ccb = l2cu_find_ccb_by_cid (NULL, cid)) == NULL)
967     {
968         L2CAP_TRACE_WARNING ("L2CAP - no CCB for L2CA_DataWrite, CID: %d", cid);
969         GKI_freebuf (p_data);
970         return (L2CAP_DW_FAILED);
971     }
972 
973 #ifndef TESTER /* Tester may send any amount of data. otherwise sending message
974                   bigger than mtu size of peer is a violation of protocol */
975     if (p_data->len > p_ccb->peer_cfg.mtu)
976     {
977         L2CAP_TRACE_WARNING ("L2CAP - CID: 0x%04x  cannot send message bigger than peer's mtu size", cid);
978         GKI_freebuf (p_data);
979         return (L2CAP_DW_FAILED);
980     }
981 #endif
982 
983     /* channel based, packet based flushable or non-flushable */
984     p_data->layer_specific = flags;
985 
986     /* If already congested, do not accept any more packets */
987     if (p_ccb->cong_sent)
988     {
989         L2CAP_TRACE_ERROR ("L2CAP - CID: 0x%04x cannot send, already congested  xmit_hold_q.count: %u  buff_quota: %u",
990                             p_ccb->local_cid, GKI_queue_length(&p_ccb->xmit_hold_q), p_ccb->buff_quota);
991 
992         GKI_freebuf (p_data);
993         return (L2CAP_DW_FAILED);
994     }
995 
996     counter_add("l2cap.dyn.tx.bytes", p_data->len);
997     counter_add("l2cap.dyn.tx.pkts", 1);
998 
999     l2c_csm_execute (p_ccb, L2CEVT_L2CA_DATA_WRITE, p_data);
1000 
1001     if (p_ccb->cong_sent)
1002         return (L2CAP_DW_CONGESTED);
1003 
1004     return (L2CAP_DW_SUCCESS);
1005 }
1006 
1007