l2c_fcr.c revision 6c303aeca25783453333172d0b29e5472f1b1c93
1/******************************************************************************
2 *
3 *  Copyright (C) 2004-2012 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 L2CAP 1.2 Flow Control and retransmissions
22 *  functions
23 *
24 ******************************************************************************/
25
26#include <stdlib.h>
27#include <string.h>
28#include <stdio.h>
29
30#include "gki.h"
31#include "bt_types.h"
32#include "hcimsgs.h"
33#include "l2cdefs.h"
34#include "l2c_int.h"
35#include "l2c_api.h"
36#include "btu.h"
37#include "btm_api.h"
38#include "btm_int.h"
39
40
41/* Flag passed to retransmit_i_frames() when all packets should be retransmitted */
42#define L2C_FCR_RETX_ALL_PKTS   0xFF
43
44#if BT_TRACE_VERBOSE == TRUE
45static char *SAR_types[] = { "Unsegmented", "Start", "End", "Continuation" };
46static char *SUP_types[] = { "RR", "REJ", "RNR", "SREJ" };
47#endif
48
49/* Look-up table for the CRC calculation */
50static const unsigned short crctab[256] = {
51    0x0000, 0xc0c1, 0xc181, 0x0140, 0xc301, 0x03c0, 0x0280, 0xc241,
52    0xc601, 0x06c0, 0x0780, 0xc741, 0x0500, 0xc5c1, 0xc481, 0x0440,
53    0xcc01, 0x0cc0, 0x0d80, 0xcd41, 0x0f00, 0xcfc1, 0xce81, 0x0e40,
54    0x0a00, 0xcac1, 0xcb81, 0x0b40, 0xc901, 0x09c0, 0x0880, 0xc841,
55    0xd801, 0x18c0, 0x1980, 0xd941, 0x1b00, 0xdbc1, 0xda81, 0x1a40,
56    0x1e00, 0xdec1, 0xdf81, 0x1f40, 0xdd01, 0x1dc0, 0x1c80, 0xdc41,
57    0x1400, 0xd4c1, 0xd581, 0x1540, 0xd701, 0x17c0, 0x1680, 0xd641,
58    0xd201, 0x12c0, 0x1380, 0xd341, 0x1100, 0xd1c1, 0xd081, 0x1040,
59    0xf001, 0x30c0, 0x3180, 0xf141, 0x3300, 0xf3c1, 0xf281, 0x3240,
60    0x3600, 0xf6c1, 0xf781, 0x3740, 0xf501, 0x35c0, 0x3480, 0xf441,
61    0x3c00, 0xfcc1, 0xfd81, 0x3d40, 0xff01, 0x3fc0, 0x3e80, 0xfe41,
62    0xfa01, 0x3ac0, 0x3b80, 0xfb41, 0x3900, 0xf9c1, 0xf881, 0x3840,
63    0x2800, 0xe8c1, 0xe981, 0x2940, 0xeb01, 0x2bc0, 0x2a80, 0xea41,
64    0xee01, 0x2ec0, 0x2f80, 0xef41, 0x2d00, 0xedc1, 0xec81, 0x2c40,
65    0xe401, 0x24c0, 0x2580, 0xe541, 0x2700, 0xe7c1, 0xe681, 0x2640,
66    0x2200, 0xe2c1, 0xe381, 0x2340, 0xe101, 0x21c0, 0x2080, 0xe041,
67    0xa001, 0x60c0, 0x6180, 0xa141, 0x6300, 0xa3c1, 0xa281, 0x6240,
68    0x6600, 0xa6c1, 0xa781, 0x6740, 0xa501, 0x65c0, 0x6480, 0xa441,
69    0x6c00, 0xacc1, 0xad81, 0x6d40, 0xaf01, 0x6fc0, 0x6e80, 0xae41,
70    0xaa01, 0x6ac0, 0x6b80, 0xab41, 0x6900, 0xa9c1, 0xa881, 0x6840,
71    0x7800, 0xb8c1, 0xb981, 0x7940, 0xbb01, 0x7bc0, 0x7a80, 0xba41,
72    0xbe01, 0x7ec0, 0x7f80, 0xbf41, 0x7d00, 0xbdc1, 0xbc81, 0x7c40,
73    0xb401, 0x74c0, 0x7580, 0xb541, 0x7700, 0xb7c1, 0xb681, 0x7640,
74    0x7200, 0xb2c1, 0xb381, 0x7340, 0xb101, 0x71c0, 0x7080, 0xb041,
75    0x5000, 0x90c1, 0x9181, 0x5140, 0x9301, 0x53c0, 0x5280, 0x9241,
76    0x9601, 0x56c0, 0x5780, 0x9741, 0x5500, 0x95c1, 0x9481, 0x5440,
77    0x9c01, 0x5cc0, 0x5d80, 0x9d41, 0x5f00, 0x9fc1, 0x9e81, 0x5e40,
78    0x5a00, 0x9ac1, 0x9b81, 0x5b40, 0x9901, 0x59c0, 0x5880, 0x9841,
79    0x8801, 0x48c0, 0x4980, 0x8941, 0x4b00, 0x8bc1, 0x8a81, 0x4a40,
80    0x4e00, 0x8ec1, 0x8f81, 0x4f40, 0x8d01, 0x4dc0, 0x4c80, 0x8c41,
81    0x4400, 0x84c1, 0x8581, 0x4540, 0x8701, 0x47c0, 0x4680, 0x8641,
82    0x8201, 0x42c0, 0x4380, 0x8341, 0x4100, 0x81c1, 0x8081, 0x4040,
83};
84
85
86/*******************************************************************************
87**  Static local functions
88*/
89static BOOLEAN process_reqseq (tL2C_CCB *p_ccb, UINT16 ctrl_word);
90static void    process_s_frame (tL2C_CCB *p_ccb, BT_HDR *p_buf, UINT16 ctrl_word);
91static void    process_i_frame (tL2C_CCB *p_ccb, BT_HDR *p_buf, UINT16 ctrl_word, BOOLEAN delay_ack);
92static BOOLEAN retransmit_i_frames (tL2C_CCB *p_ccb, UINT8 tx_seq);
93static void    prepare_I_frame (tL2C_CCB *p_ccb, BT_HDR *p_buf, BOOLEAN is_retransmission);
94static void    process_stream_frame (tL2C_CCB *p_ccb, BT_HDR *p_buf);
95static BOOLEAN do_sar_reassembly (tL2C_CCB *p_ccb, BT_HDR *p_buf, UINT16 ctrl_word);
96
97#if L2CAP_CORRUPT_ERTM_PKTS == TRUE
98static BOOLEAN l2c_corrupt_the_fcr_packet (tL2C_CCB *p_ccb, BT_HDR *p_buf,
99                                           BOOLEAN is_rx, UINT16 ctrl_word);
100static BOOLEAN l2c_bypass_sframe_packet (tL2C_CCB *p_ccb);
101#endif
102
103#if (L2CAP_ERTM_STATS == TRUE)
104static void l2c_fcr_collect_ack_delay (tL2C_CCB *p_ccb, UINT8 num_bufs_acked);
105#endif
106
107/*******************************************************************************
108**
109** Function         l2c_fcr_updcrc
110**
111** Description      This function computes the CRC using the look-up table.
112**
113** Returns          CRC
114**
115*******************************************************************************/
116unsigned short l2c_fcr_updcrc(unsigned short icrc, unsigned char *icp, int icnt)
117{
118    register unsigned short crc = icrc;
119    register unsigned char  *cp = icp;
120    register          int   cnt = icnt;
121
122    while (cnt--)
123    {
124        crc = ((crc >> 8) & 0xff) ^ crctab[(crc & 0xff) ^ *cp++];
125    }
126
127    return(crc);
128}
129
130
131/*******************************************************************************
132**
133** Function         l2c_fcr_tx_get_fcs
134**
135** Description      This function computes the CRC for a frame to be TXed.
136**
137** Returns          CRC
138**
139*******************************************************************************/
140UINT16 l2c_fcr_tx_get_fcs (BT_HDR *p_buf)
141{
142    UINT8   *p = ((UINT8 *) (p_buf + 1)) + p_buf->offset;
143
144    return (l2c_fcr_updcrc (L2CAP_FCR_INIT_CRC, p, p_buf->len));
145}
146
147/*******************************************************************************
148**
149** Function         l2c_fcr_rx_get_fcs
150**
151** Description      This function computes the CRC for a received frame.
152**
153** Returns          CRC
154**
155*******************************************************************************/
156UINT16 l2c_fcr_rx_get_fcs (BT_HDR *p_buf)
157{
158    UINT8   *p = ((UINT8 *) (p_buf + 1)) + p_buf->offset;
159
160    /* offset points past the L2CAP header, but the CRC check includes it */
161    p -= L2CAP_PKT_OVERHEAD;
162
163    return (l2c_fcr_updcrc (L2CAP_FCR_INIT_CRC, p, p_buf->len + L2CAP_PKT_OVERHEAD));
164}
165
166/*******************************************************************************
167**
168** Function         l2c_fcr_start_timer
169**
170** Description      This function starts the (monitor or retransmission) timer.
171**
172** Returns          -
173**
174*******************************************************************************/
175void l2c_fcr_start_timer (tL2C_CCB *p_ccb)
176{
177    UINT32  tout;
178
179    /* The timers which are in milliseconds */
180    if (p_ccb->fcrb.wait_ack)
181    {
182        tout = (UINT32)p_ccb->our_cfg.fcr.mon_tout;
183    }
184    else
185    {
186        tout = (UINT32)p_ccb->our_cfg.fcr.rtrans_tout;
187    }
188/*
189    L2CAP_TRACE_DEBUG ("l2c_fcr_start_timer Tout: %u  Already Running: %u  wait_ack: %u  ack_q_count: %u",
190                        tout, p_ccb->timer_entry.in_use, p_ccb->fcrb.wait_ack, p_ccb->fcrb.waiting_for_ack_q.count);
191*/
192    /* Only start a timer that was not started */
193    if (p_ccb->fcrb.mon_retrans_timer.in_use == 0)
194        btu_start_quick_timer (&p_ccb->fcrb.mon_retrans_timer, BTU_TTYPE_L2CAP_CHNL, tout*QUICK_TIMER_TICKS_PER_SEC/1000);
195}
196
197/*******************************************************************************
198**
199** Function         l2c_fcr_stop_timer
200**
201** Description      This function stops the (monitor or transmission) timer.
202**
203** Returns          -
204**
205*******************************************************************************/
206void l2c_fcr_stop_timer (tL2C_CCB *p_ccb)
207{
208    if (p_ccb->fcrb.mon_retrans_timer.in_use)
209    {
210/*
211        L2CAP_TRACE_DEBUG ("l2c_fcr_stop_timer wait_ack: %u  ack_q_count: %u",
212                            p_ccb->fcrb.wait_ack, p_ccb->fcrb.waiting_for_ack_q.count);
213*/
214        btu_stop_quick_timer (&p_ccb->fcrb.mon_retrans_timer);
215    }
216}
217
218/*******************************************************************************
219**
220** Function         l2c_fcr_cleanup
221**
222** Description      This function cleans up the variable used for flow-control/retrans.
223**
224** Returns          -
225**
226*******************************************************************************/
227void l2c_fcr_cleanup (tL2C_CCB *p_ccb)
228{
229    tL2C_FCRB *p_fcrb = &p_ccb->fcrb;
230
231    l2c_fcr_stop_timer (p_ccb);
232
233    if (p_fcrb->p_rx_sdu)
234        GKI_freebuf (p_fcrb->p_rx_sdu);
235
236    while (!GKI_queue_is_empty(&p_fcrb->waiting_for_ack_q))
237        GKI_freebuf (GKI_dequeue (&p_fcrb->waiting_for_ack_q));
238
239    while (!GKI_queue_is_empty(&p_fcrb->srej_rcv_hold_q))
240        GKI_freebuf (GKI_dequeue (&p_fcrb->srej_rcv_hold_q));
241
242    while (!GKI_queue_is_empty(&p_fcrb->retrans_q))
243        GKI_freebuf (GKI_dequeue (&p_fcrb->retrans_q));
244
245    btu_stop_quick_timer (&p_fcrb->ack_timer);
246    btu_stop_quick_timer (&p_ccb->fcrb.mon_retrans_timer);
247
248#if (L2CAP_ERTM_STATS == TRUE)
249    if ( (p_ccb->local_cid >= L2CAP_BASE_APPL_CID) && (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_ERTM_MODE) )
250    {
251        UINT32  dur = GKI_get_os_tick_count() - p_ccb->fcrb.connect_tick_count;
252        char    *p_str = (char *)GKI_getbuf(120);
253        UINT16  i;
254        UINT32  throughput_avg, ack_delay_avg, ack_q_count_avg;
255
256        dur = GKI_OS_TICKS_TO_MS(dur);
257        BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC,
258                   "---  L2CAP ERTM  Stats for CID: 0x%04x   Duration: %08ums", p_ccb->local_cid, dur);
259        BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC,
260                   "Retransmissions:%08u Times Flow Controlled:%08u Retrans Touts:%08u Ack Touts:%08u",
261                    p_ccb->fcrb.pkts_retransmitted, p_ccb->fcrb.xmit_window_closed, p_ccb->fcrb.retrans_touts, p_ccb->fcrb.xmit_ack_touts);
262        BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC,
263                   "Times there is less than 2 packets in controller when flow controlled:%08u", p_ccb->fcrb.controller_idle);
264        BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC,
265                   "max_held_acks:%08u, in_cfg.fcr.tx_win_sz:%08u", p_ccb->fcrb.max_held_acks, p_ccb->peer_cfg.fcr.tx_win_sz );
266        if (p_str)
267        {
268            sprintf(p_str, "Sent Pkts:%08u Bytes:%10u(%06u/sec) RR:%08u REJ:%08u RNR:%08u SREJ:%08u",
269                p_ccb->fcrb.ertm_pkt_counts[0], p_ccb->fcrb.ertm_byte_counts[0],
270                (dur >= 10 ? (p_ccb->fcrb.ertm_byte_counts[0] * 100) / (dur / 10) : 0),
271                p_ccb->fcrb.s_frames_sent[0], p_ccb->fcrb.s_frames_sent[1], p_ccb->fcrb.s_frames_sent[2], p_ccb->fcrb.s_frames_sent[3]);
272
273            BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC, "%s", p_str);
274
275            sprintf(p_str, "Rcvd Pkts:%08u Bytes:%10u(%06u/sec) RR:%08u REJ:%08u RNR:%08u SREJ:%08u",
276                p_ccb->fcrb.ertm_pkt_counts[1], p_ccb->fcrb.ertm_byte_counts[1],
277                (dur >= 10 ? (p_ccb->fcrb.ertm_byte_counts[1] * 100) / (dur / 10) : 0),
278                p_ccb->fcrb.s_frames_rcvd[0], p_ccb->fcrb.s_frames_rcvd[1], p_ccb->fcrb.s_frames_rcvd[2], p_ccb->fcrb.s_frames_rcvd[3]);
279
280            BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC, "%s", p_str);
281
282            throughput_avg  = 0;
283            ack_delay_avg   = 0;
284            ack_q_count_avg = 0;
285
286            for (i = 0; i < L2CAP_ERTM_STATS_NUM_AVG; i++ )
287            {
288                if (i == p_ccb->fcrb.ack_delay_avg_index )
289                {
290                    BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC,
291                           "[%02u] collecting data ...", i );
292                    continue;
293                }
294
295                sprintf(p_str, "[%02u] throughput: %5u, ack_delay avg:%3u, min:%3u, max:%3u, ack_q_count avg:%3u, min:%3u, max:%3u",
296                        i, p_ccb->fcrb.throughput[i],
297                        p_ccb->fcrb.ack_delay_avg[i], p_ccb->fcrb.ack_delay_min[i], p_ccb->fcrb.ack_delay_max[i],
298                        p_ccb->fcrb.ack_q_count_avg[i], p_ccb->fcrb.ack_q_count_min[i], p_ccb->fcrb.ack_q_count_max[i] );
299
300                BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC, "%s", p_str);
301
302                throughput_avg  += p_ccb->fcrb.throughput[i];
303                ack_delay_avg   += p_ccb->fcrb.ack_delay_avg[i];
304                ack_q_count_avg += p_ccb->fcrb.ack_q_count_avg[i];
305            }
306
307            throughput_avg  /= (L2CAP_ERTM_STATS_NUM_AVG - 1);
308            ack_delay_avg   /= (L2CAP_ERTM_STATS_NUM_AVG - 1);
309            ack_q_count_avg /= (L2CAP_ERTM_STATS_NUM_AVG - 1);
310
311            BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC,
312                   "throughput_avg: %8u (kbytes/sec), ack_delay_avg: %8u ms, ack_q_count_avg: %8u",
313                    throughput_avg, ack_delay_avg, ack_q_count_avg );
314
315            GKI_freebuf(p_str);
316        }
317
318        BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC,
319                   "---");
320    }
321#endif
322
323    memset (p_fcrb, 0, sizeof (tL2C_FCRB));
324}
325
326/*******************************************************************************
327**
328** Function         l2c_fcr_clone_buf
329**
330** Description      This function allocates and copies requested part of a buffer
331**                  at a new-offset.
332**
333** Returns          pointer to new buffer
334**
335*******************************************************************************/
336BT_HDR *l2c_fcr_clone_buf (BT_HDR *p_buf, UINT16 new_offset, UINT16 no_of_bytes, UINT8 pool)
337{
338    BT_HDR *p_buf2;
339
340    /* If using the common pool, should be at least 10% free. */
341    if ( (pool == HCI_ACL_POOL_ID) && (GKI_poolutilization (pool) > 90) )
342    {
343        L2CAP_TRACE_ERROR ("L2CAP - failed to clone buffer on HCI_ACL_POOL_ID Utilization: %u", GKI_poolutilization(pool));
344        return (NULL);
345    }
346
347    if ((p_buf2 = (BT_HDR *)GKI_getpoolbuf(pool)) != NULL)
348    {
349        UINT16    pool_buf_size = GKI_get_pool_bufsize (pool);
350
351        /* Make sure buffer fits into buffer pool */
352        if ((no_of_bytes + sizeof(BT_HDR) + new_offset) > pool_buf_size)
353        {
354            L2CAP_TRACE_ERROR("##### l2c_fcr_clone_buf (NumBytes %d) -> Exceeds poolsize %d [bytes %d + BT_HDR %d + offset %d]",
355                               (no_of_bytes + sizeof(BT_HDR) + new_offset),
356                               pool_buf_size, no_of_bytes, sizeof(BT_HDR),
357                               new_offset);
358
359            GKI_freebuf(p_buf2);
360            return (NULL);
361        }
362
363        p_buf2->offset = new_offset;
364        p_buf2->len    = no_of_bytes;
365
366        memcpy (((UINT8 *)(p_buf2 + 1)) + p_buf2->offset,
367                ((UINT8 *)(p_buf + 1))  + p_buf->offset,
368                no_of_bytes);
369    }
370    else
371    {
372        L2CAP_TRACE_ERROR ("L2CAP - failed to clone buffer, Pool: %u  Count: %u", pool,  GKI_poolfreecount(pool));
373    }
374
375    return (p_buf2);
376}
377
378/*******************************************************************************
379**
380** Function         l2c_fcr_is_flow_controlled
381**
382** Description      This function checks if the CCB is flow controlled by peer.
383**
384** Returns          The control word
385**
386*******************************************************************************/
387BOOLEAN l2c_fcr_is_flow_controlled (tL2C_CCB *p_ccb)
388{
389    if (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_ERTM_MODE)
390    {
391        /* Check if remote side flowed us off or the transmit window is full */
392        if ( (p_ccb->fcrb.remote_busy == TRUE)
393         ||  (GKI_queue_length(&p_ccb->fcrb.waiting_for_ack_q) >= p_ccb->peer_cfg.fcr.tx_win_sz) )
394        {
395#if (L2CAP_ERTM_STATS == TRUE)
396            if (!GKI_queue_is_empty(&p_ccb->xmit_hold_q))
397            {
398                p_ccb->fcrb.xmit_window_closed++;
399
400                if ((p_ccb->p_lcb->sent_not_acked < 2)&&(l2cb.controller_xmit_window > 0))
401                    p_ccb->fcrb.controller_idle++;
402            }
403#endif
404            return (TRUE);
405        }
406    }
407    return (FALSE);
408}
409
410/*******************************************************************************
411**
412** Function         prepare_I_frame
413**
414** Description      This function sets the FCR variables in an I-frame that is
415**                  about to be sent to HCI for transmission. This may be the
416**                  first time the I-frame is sent, or a retransmission
417**
418** Returns          -
419**
420*******************************************************************************/
421static void prepare_I_frame (tL2C_CCB *p_ccb, BT_HDR *p_buf, BOOLEAN is_retransmission)
422{
423    tL2C_FCRB   *p_fcrb = &p_ccb->fcrb;
424    UINT8       *p;
425    UINT16      fcs;
426    UINT16      ctrl_word;
427    BOOLEAN     set_f_bit = p_fcrb->send_f_rsp;
428
429    p_fcrb->send_f_rsp = FALSE;
430
431    if (is_retransmission)
432    {
433        /* Get the old control word and clear out the old req_seq and F bits */
434        p = ((UINT8 *) (p_buf+1)) + p_buf->offset + L2CAP_PKT_OVERHEAD;
435
436        STREAM_TO_UINT16 (ctrl_word, p);
437
438        ctrl_word  &= ~(L2CAP_FCR_REQ_SEQ_BITS + L2CAP_FCR_F_BIT);
439    }
440    else
441    {
442        ctrl_word  = p_buf->layer_specific & L2CAP_FCR_SEG_BITS;                /* SAR bits */
443        ctrl_word |= (p_fcrb->next_tx_seq << L2CAP_FCR_TX_SEQ_BITS_SHIFT);      /* Tx Seq */
444
445        p_fcrb->next_tx_seq = (p_fcrb->next_tx_seq + 1) & L2CAP_FCR_SEQ_MODULO;
446    }
447
448    /* Set the F-bit and reqseq only if using re-transmission mode */
449    if (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_ERTM_MODE)
450    {
451        if (set_f_bit)
452            ctrl_word |= L2CAP_FCR_F_BIT;
453
454        ctrl_word |= (p_fcrb->next_seq_expected) << L2CAP_FCR_REQ_SEQ_BITS_SHIFT;
455
456        p_fcrb->last_ack_sent = p_ccb->fcrb.next_seq_expected;
457
458        if (p_ccb->fcrb.ack_timer.in_use)
459            btu_stop_quick_timer (&p_ccb->fcrb.ack_timer);
460    }
461
462    /* Set the control word */
463    p = ((UINT8 *) (p_buf+1)) + p_buf->offset + L2CAP_PKT_OVERHEAD;
464
465    UINT16_TO_STREAM (p, ctrl_word);
466
467    /* Compute the FCS and add to the end of the buffer if not bypassed */
468    if (p_ccb->bypass_fcs != L2CAP_BYPASS_FCS)
469    {
470        /* length field in l2cap header has to include FCS length */
471        p = ((UINT8 *) (p_buf+1)) + p_buf->offset;
472        UINT16_TO_STREAM (p, p_buf->len + L2CAP_FCS_LEN - L2CAP_PKT_OVERHEAD);
473
474        /* Calculate the FCS */
475        fcs = l2c_fcr_tx_get_fcs(p_buf);
476
477        /* Point to the end of the buffer and put the FCS there */
478        p = ((UINT8 *) (p_buf+1)) + p_buf->offset + p_buf->len;
479
480        UINT16_TO_STREAM (p, fcs);
481
482        p_buf->len += L2CAP_FCS_LEN;
483    }
484
485#if BT_TRACE_VERBOSE == TRUE
486    if (is_retransmission)
487    {
488        L2CAP_TRACE_EVENT ("L2CAP eRTM ReTx I-frame  CID: 0x%04x  Len: %u  SAR: %s  TxSeq: %u  ReqSeq: %u  F: %u",
489                            p_ccb->local_cid, p_buf->len,
490                            SAR_types[(ctrl_word & L2CAP_FCR_SAR_BITS) >> L2CAP_FCR_SAR_BITS_SHIFT],
491                            (ctrl_word & L2CAP_FCR_TX_SEQ_BITS) >> L2CAP_FCR_TX_SEQ_BITS_SHIFT,
492                            (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT,
493                            (ctrl_word & L2CAP_FCR_F_BIT) >> L2CAP_FCR_F_BIT_SHIFT);
494    }
495    else
496    {
497        L2CAP_TRACE_EVENT ("L2CAP eRTM Tx I-frame CID: 0x%04x  Len: %u  SAR: %-12s  TxSeq: %u  ReqSeq: %u  F: %u",
498                            p_ccb->local_cid, p_buf->len,
499                            SAR_types[(ctrl_word & L2CAP_FCR_SAR_BITS) >> L2CAP_FCR_SAR_BITS_SHIFT],
500                            (ctrl_word & L2CAP_FCR_TX_SEQ_BITS) >> L2CAP_FCR_TX_SEQ_BITS_SHIFT,
501                            (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT,
502                            (ctrl_word & L2CAP_FCR_F_BIT) >> L2CAP_FCR_F_BIT_SHIFT);
503    }
504#endif
505
506    /* Start the retransmission timer if not already running */
507    if (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_ERTM_MODE)
508        l2c_fcr_start_timer (p_ccb);
509}
510
511/*******************************************************************************
512**
513** Function         l2c_fcr_send_S_frame
514**
515** Description      This function formats and sends an S-frame for transmission.
516**
517** Returns          -
518**
519*******************************************************************************/
520void l2c_fcr_send_S_frame (tL2C_CCB *p_ccb, UINT16 function_code, UINT16 pf_bit)
521{
522    BT_HDR      *p_buf;
523    UINT8       *p;
524    UINT16      ctrl_word;
525    UINT16      fcs;
526
527#if L2CAP_CORRUPT_ERTM_PKTS == TRUE
528    /* Only used for conformance testing */
529    if (l2c_bypass_sframe_packet (p_ccb))
530        return;
531#endif
532
533    if ((!p_ccb->in_use) || (p_ccb->chnl_state != CST_OPEN))
534        return;
535
536#if (L2CAP_ERTM_STATS == TRUE)
537     p_ccb->fcrb.s_frames_sent[function_code]++;
538#endif
539
540    if (pf_bit == L2CAP_FCR_P_BIT)
541    {
542        p_ccb->fcrb.wait_ack = TRUE;
543
544        l2c_fcr_stop_timer (p_ccb);         /* Restart the monitor timer */
545        l2c_fcr_start_timer (p_ccb);
546    }
547
548    /* Create the control word to use */
549    ctrl_word = (function_code << L2CAP_FCR_SUP_SHIFT) | L2CAP_FCR_S_FRAME_BIT;
550    ctrl_word |= (p_ccb->fcrb.next_seq_expected << L2CAP_FCR_REQ_SEQ_BITS_SHIFT);
551    ctrl_word |= pf_bit;
552
553    if ((p_buf = (BT_HDR *)GKI_getpoolbuf (L2CAP_CMD_POOL_ID)) != NULL)
554    {
555        p_buf->offset = HCI_DATA_PREAMBLE_SIZE;
556        p_buf->len    = L2CAP_PKT_OVERHEAD + L2CAP_FCR_OVERHEAD;
557
558        /* Set the pointer to the beginning of the data */
559        p = (UINT8 *)(p_buf + 1) + p_buf->offset;
560
561        /* Put in the L2CAP header */
562        UINT16_TO_STREAM (p, L2CAP_FCR_OVERHEAD + L2CAP_FCS_LEN);
563        UINT16_TO_STREAM (p, p_ccb->remote_cid);
564        UINT16_TO_STREAM (p, ctrl_word);
565
566        /* Compute the FCS and add to the end of the buffer if not bypassed */
567        if (p_ccb->bypass_fcs != L2CAP_BYPASS_FCS)
568        {
569            fcs = l2c_fcr_tx_get_fcs (p_buf);
570
571            UINT16_TO_STREAM (p, fcs);
572            p_buf->len += L2CAP_FCS_LEN;
573        }
574        else /* rewrite the length without FCS length */
575        {
576            p -= 6;
577            UINT16_TO_STREAM (p, L2CAP_FCR_OVERHEAD);
578        }
579
580#if L2CAP_CORRUPT_ERTM_PKTS == TRUE
581        /* Get out if packet was dropped */
582        if (l2c_corrupt_the_fcr_packet (p_ccb, p_buf, FALSE, ctrl_word))
583            return;
584#endif
585        /* Now, the HCI transport header */
586        p_buf->layer_specific = L2CAP_NON_FLUSHABLE_PKT;
587        l2cu_set_acl_hci_header (p_buf, p_ccb);
588
589#if BT_TRACE_VERBOSE == TRUE
590        if ((((ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT) == 1)
591         || (((ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT) == 3))
592        {
593            L2CAP_TRACE_WARNING ("L2CAP eRTM Tx S-frame  CID: 0x%04x  ctrlword: 0x%04x  Type: %s  ReqSeq: %u  P: %u  F: %u",
594                            p_ccb->local_cid, ctrl_word,
595                            SUP_types[(ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT],
596                            (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT,
597                            (ctrl_word & L2CAP_FCR_P_BIT) >> L2CAP_FCR_P_BIT_SHIFT,
598                            (ctrl_word & L2CAP_FCR_F_BIT) >> L2CAP_FCR_F_BIT_SHIFT);
599            L2CAP_TRACE_WARNING ("                  Buf Len: %u", p_buf->len);
600        }
601        else
602        {
603            L2CAP_TRACE_EVENT ("L2CAP eRTM Tx S-frame  CID: 0x%04x  ctrlword: 0x%04x  Type: %s  ReqSeq: %u  P: %u  F: %u",
604                            p_ccb->local_cid, ctrl_word,
605                            SUP_types[(ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT],
606                            (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT,
607                            (ctrl_word & L2CAP_FCR_P_BIT) >> L2CAP_FCR_P_BIT_SHIFT,
608                            (ctrl_word & L2CAP_FCR_F_BIT) >> L2CAP_FCR_F_BIT_SHIFT);
609            L2CAP_TRACE_EVENT ("                  Buf Len: %u", p_buf->len);
610        }
611#endif  /* BT_TRACE_VERBOSE */
612
613        l2c_link_check_send_pkts (p_ccb->p_lcb, NULL, p_buf);
614
615        p_ccb->fcrb.last_ack_sent = p_ccb->fcrb.next_seq_expected;
616
617        if (p_ccb->fcrb.ack_timer.in_use)
618            btu_stop_quick_timer (&p_ccb->fcrb.ack_timer);
619    }
620    else
621    {
622        L2CAP_TRACE_ERROR ("l2c_fcr_send_S_frame(No Resources) cid 0x%04x, Type: 0x%4x",
623                             p_ccb->local_cid, function_code);
624    }
625}
626
627
628/*******************************************************************************
629**
630** Function         l2c_fcr_proc_pdu
631**
632** Description      This function is the entry point for processing of a
633**                  received PDU when in flow control and/or retransmission modes.
634**
635** Returns          -
636**
637*******************************************************************************/
638void l2c_fcr_proc_pdu (tL2C_CCB *p_ccb, BT_HDR *p_buf)
639{
640    UINT8       *p;
641    UINT16      fcs;
642    UINT16      min_pdu_len;
643    UINT16      ctrl_word;
644
645    /* Check the length */
646    min_pdu_len = (p_ccb->bypass_fcs == L2CAP_BYPASS_FCS) ?
647                  (UINT16)L2CAP_FCR_OVERHEAD : (UINT16)(L2CAP_FCS_LEN + L2CAP_FCR_OVERHEAD);
648
649    if (p_buf->len < min_pdu_len)
650    {
651        L2CAP_TRACE_WARNING ("Rx L2CAP PDU: CID: 0x%04x  Len too short: %u", p_ccb->local_cid, p_buf->len);
652        GKI_freebuf (p_buf);
653        return;
654    }
655
656    if (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_STREAM_MODE)
657    {
658        process_stream_frame (p_ccb, p_buf);
659        return;
660    }
661
662#if BT_TRACE_VERBOSE == TRUE
663    /* Get the control word */
664    p = ((UINT8 *)(p_buf+1)) + p_buf->offset;
665    STREAM_TO_UINT16 (ctrl_word, p);
666
667    if (ctrl_word & L2CAP_FCR_S_FRAME_BIT)
668    {
669        if ((((ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT) == 1)
670         || (((ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT) == 3))
671        {
672            /* REJ or SREJ */
673            L2CAP_TRACE_WARNING ("L2CAP eRTM Rx S-frame: cid: 0x%04x  Len: %u  Type: %s  ReqSeq: %u  P: %u  F: %u",
674                            p_ccb->local_cid, p_buf->len,
675                            SUP_types[(ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT],
676                            (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT,
677                            (ctrl_word & L2CAP_FCR_P_BIT) >> L2CAP_FCR_P_BIT_SHIFT,
678                            (ctrl_word & L2CAP_FCR_F_BIT) >> L2CAP_FCR_F_BIT_SHIFT);
679        }
680        else
681        {
682            L2CAP_TRACE_EVENT ("L2CAP eRTM Rx S-frame: cid: 0x%04x  Len: %u  Type: %s  ReqSeq: %u  P: %u  F: %u",
683                            p_ccb->local_cid, p_buf->len,
684                            SUP_types[(ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT],
685                            (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT,
686                            (ctrl_word & L2CAP_FCR_P_BIT) >> L2CAP_FCR_P_BIT_SHIFT,
687                            (ctrl_word & L2CAP_FCR_F_BIT) >> L2CAP_FCR_F_BIT_SHIFT);
688        }
689    }
690    else
691    {
692        L2CAP_TRACE_EVENT ("L2CAP eRTM Rx I-frame: cid: 0x%04x  Len: %u  SAR: %-12s  TxSeq: %u  ReqSeq: %u  F: %u",
693                            p_ccb->local_cid, p_buf->len,
694                            SAR_types[(ctrl_word & L2CAP_FCR_SAR_BITS) >> L2CAP_FCR_SAR_BITS_SHIFT],
695                            (ctrl_word & L2CAP_FCR_TX_SEQ_BITS) >> L2CAP_FCR_TX_SEQ_BITS_SHIFT,
696                            (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT,
697                            (ctrl_word & L2CAP_FCR_F_BIT) >> L2CAP_FCR_F_BIT_SHIFT);
698    }
699
700    L2CAP_TRACE_EVENT ("      eRTM Rx Nxt_tx_seq %u, Lst_rx_ack %u, Nxt_seq_exp %u, Lst_ack_snt %u, wt_q.cnt %u, tries %u",
701                        p_ccb->fcrb.next_tx_seq, p_ccb->fcrb.last_rx_ack, p_ccb->fcrb.next_seq_expected,
702                        p_ccb->fcrb.last_ack_sent, GKI_queue_length(&p_ccb->fcrb.waiting_for_ack_q), p_ccb->fcrb.num_tries);
703
704#endif /* BT_TRACE_VERBOSE */
705
706#if L2CAP_CORRUPT_ERTM_PKTS == TRUE
707    p = ((UINT8 *)(p_buf+1)) + p_buf->offset;
708    STREAM_TO_UINT16 (ctrl_word, p);
709
710    /* Get out if packet was dropped */
711    if (l2c_corrupt_the_fcr_packet (p_ccb, p_buf, TRUE, ctrl_word))
712        return;
713#endif  /* L2CAP_CORRUPT_ERTM_PKTS */
714
715    /* Verify FCS if using */
716    if (p_ccb->bypass_fcs != L2CAP_BYPASS_FCS)
717    {
718        p = ((UINT8 *)(p_buf+1)) + p_buf->offset + p_buf->len - L2CAP_FCS_LEN;
719
720        /* Extract and drop the FCS from the packet */
721        STREAM_TO_UINT16 (fcs, p);
722        p_buf->len -= L2CAP_FCS_LEN;
723
724        if (l2c_fcr_rx_get_fcs(p_buf) != fcs)
725        {
726            L2CAP_TRACE_WARNING ("Rx L2CAP PDU: CID: 0x%04x  BAD FCS", p_ccb->local_cid);
727            GKI_freebuf(p_buf);
728            return;
729        }
730    }
731
732    /* Get the control word */
733    p = ((UINT8 *)(p_buf+1)) + p_buf->offset;
734
735    STREAM_TO_UINT16 (ctrl_word, p);
736
737    p_buf->len    -= L2CAP_FCR_OVERHEAD;
738    p_buf->offset += L2CAP_FCR_OVERHEAD;
739
740    /* If we had a poll bit outstanding, check if we got a final response */
741    if (p_ccb->fcrb.wait_ack)
742    {
743        /* If final bit not set, ignore the frame unless it is a polled S-frame */
744        if ( !(ctrl_word & L2CAP_FCR_F_BIT) )
745        {
746            if ( (ctrl_word & L2CAP_FCR_P_BIT) && (ctrl_word & L2CAP_FCR_S_FRAME_BIT) )
747            {
748                if (p_ccb->fcrb.srej_sent)
749                    l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_SREJ, L2CAP_FCR_F_BIT);
750                else if (p_ccb->fcrb.local_busy)
751                    l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RNR, L2CAP_FCR_F_BIT);
752                else
753                    l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RR, L2CAP_FCR_F_BIT);
754
755                /* Got a poll while in wait_ack state, so re-start our timer with 1-second */
756                /* This is a small optimization... the monitor timer is 12 secs, but we saw */
757                /* that if the other side sends us a poll when we are waiting for a final,  */
758                /* then it speeds up recovery significantly if we poll him back soon after his poll. */
759                btu_start_quick_timer (&p_ccb->fcrb.mon_retrans_timer, BTU_TTYPE_L2CAP_CHNL, QUICK_TIMER_TICKS_PER_SEC);
760            }
761            GKI_freebuf (p_buf);
762            return;
763        }
764
765        p_ccb->fcrb.wait_ack  = FALSE;
766
767        /* P and F are mutually exclusive */
768        if (ctrl_word & L2CAP_FCR_S_FRAME_BIT)
769            ctrl_word &= ~L2CAP_FCR_P_BIT;
770
771        if (GKI_queue_is_empty(&p_ccb->fcrb.waiting_for_ack_q))
772            p_ccb->fcrb.num_tries = 0;
773
774        l2c_fcr_stop_timer (p_ccb);
775    }
776    else
777    {
778        /* Otherwise, ensure the final bit is ignored */
779        ctrl_word &= ~L2CAP_FCR_F_BIT;
780    }
781
782    /* Process receive sequence number */
783    if (!process_reqseq (p_ccb, ctrl_word))
784    {
785        GKI_freebuf (p_buf);
786        return;
787    }
788
789     /* Process based on whether it is an S-frame or an I-frame */
790    if (ctrl_word & L2CAP_FCR_S_FRAME_BIT)
791        process_s_frame (p_ccb, p_buf, ctrl_word);
792    else
793        process_i_frame (p_ccb, p_buf, ctrl_word, FALSE);
794
795    /* Return if the channel got disconnected by a bad packet or max retransmissions */
796    if ( (!p_ccb->in_use) || (p_ccb->chnl_state != CST_OPEN) )
797        return;
798
799    /* If we have some buffers held while doing SREJ, and SREJ has cleared, process them now */
800    if ( (!p_ccb->fcrb.local_busy) && (!p_ccb->fcrb.srej_sent) && (!GKI_queue_is_empty(&p_ccb->fcrb.srej_rcv_hold_q)))
801    {
802        BUFFER_Q temp_q = p_ccb->fcrb.srej_rcv_hold_q;
803
804        GKI_init_q (&p_ccb->fcrb.srej_rcv_hold_q);
805
806        while ((p_buf = (BT_HDR *)GKI_dequeue (&temp_q)) != NULL)
807        {
808            if (p_ccb->in_use && (p_ccb->chnl_state == CST_OPEN))
809            {
810                /* Get the control word */
811                p = ((UINT8 *)(p_buf+1)) + p_buf->offset - L2CAP_FCR_OVERHEAD;
812
813                STREAM_TO_UINT16 (ctrl_word, p);
814
815                L2CAP_TRACE_DEBUG ("l2c_fcr_proc_pdu() CID: 0x%04x  Process Buffer from SREJ_Hold_Q   TxSeq: %u  Expected_Seq: %u",
816                                    p_ccb->local_cid, (ctrl_word & L2CAP_FCR_TX_SEQ_BITS) >> L2CAP_FCR_TX_SEQ_BITS_SHIFT,
817                                    p_ccb->fcrb.next_seq_expected);
818
819                /* Process the SREJ held I-frame, but do not send an RR for each individual frame */
820                process_i_frame (p_ccb, p_buf, ctrl_word, TRUE);
821            }
822            else
823                GKI_freebuf (p_buf);
824
825            /* If more frames were lost during SREJ, send a REJ */
826            if (p_ccb->fcrb.rej_after_srej)
827            {
828                p_ccb->fcrb.rej_after_srej = FALSE;
829                p_ccb->fcrb.rej_sent       = TRUE;
830
831                l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_REJ, 0);
832            }
833        }
834
835        /* Now, if needed, send one RR for the whole held queue */
836        if ( (!p_ccb->fcrb.local_busy) && (!p_ccb->fcrb.rej_sent) && (!p_ccb->fcrb.srej_sent)
837         &&  (p_ccb->fcrb.next_seq_expected != p_ccb->fcrb.last_ack_sent) )
838            l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RR, 0);
839        else
840        {
841            L2CAP_TRACE_DEBUG ("l2c_fcr_proc_pdu() not sending RR CID: 0x%04x  local_busy:%d rej_sent:%d srej_sent:%d Expected_Seq:%u Last_Ack:%u",
842                                p_ccb->local_cid, p_ccb->fcrb.local_busy, p_ccb->fcrb.rej_sent, p_ccb->fcrb.srej_sent, p_ccb->fcrb.next_seq_expected,
843                                p_ccb->fcrb.last_ack_sent);
844        }
845    }
846
847    /* If a window has opened, check if we can send any more packets */
848    if ( (!GKI_queue_is_empty(&p_ccb->fcrb.retrans_q) || !GKI_queue_is_empty(&p_ccb->xmit_hold_q))
849      && (p_ccb->fcrb.wait_ack == FALSE)
850      && (l2c_fcr_is_flow_controlled (p_ccb) == FALSE) )
851    {
852        l2c_link_check_send_pkts (p_ccb->p_lcb, NULL, NULL);
853    }
854}
855
856/*******************************************************************************
857**
858** Function         l2c_fcr_proc_tout
859**
860** Description      Handle a timeout. We should be in error recovery state.
861**
862** Returns          -
863**
864*******************************************************************************/
865void l2c_fcr_proc_tout (tL2C_CCB *p_ccb)
866{
867    L2CAP_TRACE_DEBUG ("l2c_fcr_proc_tout:  CID: 0x%04x  num_tries: %u (max: %u)  wait_ack: %u  ack_q_count: %u",
868                        p_ccb->local_cid, p_ccb->fcrb.num_tries, p_ccb->peer_cfg.fcr.max_transmit,
869                        p_ccb->fcrb.wait_ack, GKI_queue_length(&p_ccb->fcrb.waiting_for_ack_q));
870
871#if (L2CAP_ERTM_STATS == TRUE)
872    p_ccb->fcrb.retrans_touts++;
873#endif
874
875    if ( (p_ccb->peer_cfg.fcr.max_transmit != 0) && (++p_ccb->fcrb.num_tries > p_ccb->peer_cfg.fcr.max_transmit) )
876    {
877        l2cu_disconnect_chnl (p_ccb);
878    }
879    else
880    {
881        if (!p_ccb->fcrb.srej_sent && !p_ccb->fcrb.rej_sent)
882        {
883            if (p_ccb->fcrb.local_busy)
884                l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RNR, L2CAP_FCR_P_BIT);
885            else
886                l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RR, L2CAP_FCR_P_BIT);
887        }
888    }
889}
890
891
892/*******************************************************************************
893**
894** Function         l2c_fcr_proc_ack_tout
895**
896** Description      Send RR/RNR if we have not acked I frame
897**
898** Returns          -
899**
900*******************************************************************************/
901void l2c_fcr_proc_ack_tout (tL2C_CCB *p_ccb)
902{
903    L2CAP_TRACE_DEBUG ("l2c_fcr_proc_ack_tout:  CID: 0x%04x State: %u  Wack:%u  Rq:%d  Acked:%d", p_ccb->local_cid,
904                        p_ccb->chnl_state, p_ccb->fcrb.wait_ack, p_ccb->fcrb.next_seq_expected, p_ccb->fcrb.last_ack_sent);
905
906    if ( (p_ccb->chnl_state == CST_OPEN) && (!p_ccb->fcrb.wait_ack)
907      && (p_ccb->fcrb.last_ack_sent != p_ccb->fcrb.next_seq_expected) )
908    {
909#if (L2CAP_ERTM_STATS == TRUE)
910        p_ccb->fcrb.xmit_ack_touts++;
911#endif
912        if (p_ccb->fcrb.local_busy)
913            l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RNR, 0);
914        else
915            l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RR, 0);
916    }
917}
918
919
920/*******************************************************************************
921**
922** Function         process_reqseq
923**
924** Description      Handle receive sequence number
925**
926** Returns          -
927**
928*******************************************************************************/
929static BOOLEAN process_reqseq (tL2C_CCB *p_ccb, UINT16 ctrl_word)
930{
931    tL2C_FCRB   *p_fcrb = &p_ccb->fcrb;
932    UINT8       req_seq, num_bufs_acked, xx;
933    UINT16      ls;
934    UINT16      full_sdus_xmitted;
935
936    /* Receive sequence number does not ack anything for SREJ with P-bit set to zero */
937    if ( (ctrl_word & L2CAP_FCR_S_FRAME_BIT)
938     &&  ((ctrl_word & L2CAP_FCR_SUP_BITS) == (L2CAP_FCR_SUP_SREJ << L2CAP_FCR_SUP_SHIFT))
939     &&  ((ctrl_word & L2CAP_FCR_P_BIT) == 0) )
940    {
941        /* If anything still waiting for ack, restart the timer if it was stopped */
942        if (!GKI_queue_is_empty(&p_fcrb->waiting_for_ack_q))
943            l2c_fcr_start_timer (p_ccb);
944
945        return (TRUE);
946    }
947
948    /* Extract the receive sequence number from the control word */
949    req_seq = (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT;
950
951    num_bufs_acked = (req_seq - p_fcrb->last_rx_ack) & L2CAP_FCR_SEQ_MODULO;
952
953    /* Verify the request sequence is in range before proceeding */
954    if (num_bufs_acked > GKI_queue_length(&p_fcrb->waiting_for_ack_q))
955    {
956        /* The channel is closed if ReqSeq is not in range */
957        L2CAP_TRACE_WARNING ("L2CAP eRTM Frame BAD Req_Seq - ctrl_word: 0x%04x  req_seq 0x%02x  last_rx_ack: 0x%02x  QCount: %u",
958                               ctrl_word, req_seq, p_fcrb->last_rx_ack, GKI_queue_length(&p_fcrb->waiting_for_ack_q));
959
960        l2cu_disconnect_chnl (p_ccb);
961        return (FALSE);
962    }
963
964/*
965    L2CAP_TRACE_DEBUG ("L2CAP process_reqseq 0x%02x  last_rx_ack: 0x%02x  QCount: %u",
966                           req_seq, p_fcrb->last_rx_ack, p_fcrb->waiting_for_ack_q.count);
967*/
968    p_fcrb->last_rx_ack = req_seq;
969
970    /* Now we can release all acknowledged frames, and restart the retransmission timer if needed */
971    if (num_bufs_acked != 0)
972    {
973        p_fcrb->num_tries = 0;
974        full_sdus_xmitted = 0;
975
976#if (L2CAP_ERTM_STATS == TRUE)
977        l2c_fcr_collect_ack_delay (p_ccb, num_bufs_acked);
978#endif
979
980        for (xx = 0; xx < num_bufs_acked; xx++)
981        {
982            ls = ((BT_HDR *)(GKI_getfirst(&p_fcrb->waiting_for_ack_q)))->layer_specific & L2CAP_FCR_SAR_BITS;
983
984            if ( (ls == L2CAP_FCR_UNSEG_SDU) || (ls == L2CAP_FCR_END_SDU) )
985                full_sdus_xmitted++;
986
987            GKI_freebuf (GKI_dequeue (&p_fcrb->waiting_for_ack_q));
988        }
989
990        /* If we are still in a wait_ack state, do not mess with the timer */
991        if (!p_ccb->fcrb.wait_ack)
992            l2c_fcr_stop_timer (p_ccb);
993
994        /* Check if we need to call the "packet_sent" callback */
995        if ( (p_ccb->p_rcb) && (p_ccb->p_rcb->api.pL2CA_TxComplete_Cb) && (full_sdus_xmitted) )
996        {
997            /* Special case for eRTM, if all packets sent, send 0xFFFF */
998            if (GKI_queue_is_empty(&p_fcrb->waiting_for_ack_q) && (GKI_queue_is_empty(&p_ccb->xmit_hold_q)))
999                full_sdus_xmitted = 0xFFFF;
1000
1001            (*p_ccb->p_rcb->api.pL2CA_TxComplete_Cb)(p_ccb->local_cid, full_sdus_xmitted);
1002        }
1003    }
1004
1005    /* If anything still waiting for ack, restart the timer if it was stopped */
1006    if (!GKI_queue_is_empty(&p_fcrb->waiting_for_ack_q))
1007        l2c_fcr_start_timer (p_ccb);
1008
1009    return (TRUE);
1010}
1011
1012
1013/*******************************************************************************
1014**
1015** Function         process_s_frame
1016**
1017** Description      Process an S frame
1018**
1019** Returns          -
1020**
1021*******************************************************************************/
1022static void process_s_frame (tL2C_CCB *p_ccb, BT_HDR *p_buf, UINT16 ctrl_word)
1023{
1024    tL2C_FCRB   *p_fcrb      = &p_ccb->fcrb;
1025    UINT16      s_frame_type = (ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT;
1026    BOOLEAN     remote_was_busy;
1027    BOOLEAN     all_ok = TRUE;
1028
1029    if (p_buf->len != 0)
1030    {
1031        L2CAP_TRACE_WARNING ("Incorrect S-frame Length (%d)", p_buf->len);
1032    }
1033
1034    L2CAP_TRACE_DEBUG ("process_s_frame ctrl_word 0x%04x fcrb_remote_busy:%d", ctrl_word, p_fcrb->remote_busy);
1035
1036#if (L2CAP_ERTM_STATS == TRUE)
1037    p_ccb->fcrb.s_frames_rcvd[s_frame_type]++;
1038#endif
1039
1040    if (ctrl_word & L2CAP_FCR_P_BIT)
1041    {
1042        p_fcrb->rej_sent   = FALSE;             /* After checkpoint, we can send anoher REJ */
1043        p_fcrb->send_f_rsp = TRUE;              /* Set a flag in case an I-frame is pending */
1044    }
1045
1046    switch (s_frame_type)
1047    {
1048    case L2CAP_FCR_SUP_RR:
1049        remote_was_busy     = p_fcrb->remote_busy;
1050        p_fcrb->remote_busy = FALSE;
1051
1052        if ( (ctrl_word & L2CAP_FCR_F_BIT) || (remote_was_busy) )
1053            all_ok = retransmit_i_frames (p_ccb, L2C_FCR_RETX_ALL_PKTS);
1054        break;
1055
1056    case L2CAP_FCR_SUP_REJ:
1057        p_fcrb->remote_busy = FALSE;
1058        all_ok = retransmit_i_frames (p_ccb, L2C_FCR_RETX_ALL_PKTS);
1059        break;
1060
1061    case L2CAP_FCR_SUP_RNR:
1062        p_fcrb->remote_busy = TRUE;
1063        l2c_fcr_stop_timer (p_ccb);
1064        break;
1065
1066    case L2CAP_FCR_SUP_SREJ:
1067        p_fcrb->remote_busy = FALSE;
1068        all_ok = retransmit_i_frames (p_ccb, (UINT8)((ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT));
1069        break;
1070    }
1071
1072    if (all_ok)
1073    {
1074        /* If polled, we need to respond with F-bit. Note, we may have sent a I-frame with the F-bit */
1075        if (p_fcrb->send_f_rsp)
1076        {
1077            if (p_fcrb->srej_sent)
1078                l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_SREJ, L2CAP_FCR_F_BIT);
1079            else if (p_fcrb->local_busy)
1080                l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RNR, L2CAP_FCR_F_BIT);
1081            else
1082                l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RR, L2CAP_FCR_F_BIT);
1083
1084            p_fcrb->send_f_rsp = FALSE;
1085        }
1086    }
1087    else
1088    {
1089        L2CAP_TRACE_DEBUG ("process_s_frame hit_max_retries");
1090    }
1091
1092    GKI_freebuf (p_buf);
1093}
1094
1095
1096/*******************************************************************************
1097**
1098** Function         process_i_frame
1099**
1100** Description      Process an I frame
1101**
1102** Returns          -
1103**
1104*******************************************************************************/
1105static void process_i_frame (tL2C_CCB *p_ccb, BT_HDR *p_buf, UINT16 ctrl_word, BOOLEAN delay_ack)
1106{
1107    tL2C_FCRB   *p_fcrb = &p_ccb->fcrb;
1108    UINT8       tx_seq, num_lost, num_to_ack, next_srej;
1109
1110    /* If we were doing checkpoint recovery, first retransmit all unacked I-frames */
1111    if (ctrl_word & L2CAP_FCR_F_BIT)
1112    {
1113        if (!retransmit_i_frames (p_ccb, L2C_FCR_RETX_ALL_PKTS))
1114        {
1115            GKI_freebuf(p_buf);
1116            return;
1117        }
1118    }
1119
1120#if (L2CAP_ERTM_STATS == TRUE)
1121    p_ccb->fcrb.ertm_pkt_counts[1]++;
1122    p_ccb->fcrb.ertm_byte_counts[1] += p_buf->len;
1123#endif
1124
1125    /* Extract the sequence number */
1126    tx_seq = (ctrl_word & L2CAP_FCR_TX_SEQ_BITS) >> L2CAP_FCR_TX_SEQ_BITS_SHIFT;
1127
1128    /* If we have flow controlled the peer, ignore any bad I-frames from him */
1129    if ( (tx_seq != p_fcrb->next_seq_expected) && (p_fcrb->local_busy) )
1130    {
1131        L2CAP_TRACE_WARNING ("Dropping bad I-Frame since we flowed off, tx_seq:%u", tx_seq);
1132        l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RNR, 0);
1133        GKI_freebuf(p_buf);
1134        return;
1135    }
1136
1137    /* If there are no free buffers in the user Rx queue, drop the  */
1138    /* received buffer now before we update any sequence numbers    */
1139    if (GKI_poolfreecount (p_ccb->ertm_info.user_rx_pool_id) == 0)
1140    {
1141        L2CAP_TRACE_WARNING ("L2CAP CID: 0x%04x  Dropping I-Frame seq: %u  User RX Pool: %u  (Size: %u)  has no free buffers!!",
1142                              p_ccb->local_cid, tx_seq, p_ccb->ertm_info.user_rx_pool_id,
1143                              GKI_poolcount (p_ccb->ertm_info.user_rx_pool_id));
1144        GKI_freebuf(p_buf);
1145        return;
1146    }
1147
1148    /* Check if tx-sequence is the expected one */
1149    if (tx_seq != p_fcrb->next_seq_expected)
1150    {
1151        num_lost = (tx_seq - p_fcrb->next_seq_expected) & L2CAP_FCR_SEQ_MODULO;
1152
1153        /* Is the frame a duplicate ? If so, just drop it */
1154        if (num_lost >= p_ccb->our_cfg.fcr.tx_win_sz)
1155        {
1156            /* Duplicate - simply drop it */
1157            L2CAP_TRACE_WARNING ("process_i_frame() Dropping Duplicate Frame tx_seq:%u  ExpectedTxSeq %u", tx_seq, p_fcrb->next_seq_expected);
1158            GKI_freebuf(p_buf);
1159        }
1160        else
1161        {
1162            L2CAP_TRACE_WARNING ("process_i_frame() CID: 0x%04x  Lost: %u  tx_seq:%u  ExpTxSeq %u  Rej: %u  SRej: %u",
1163                                 p_ccb->local_cid, num_lost, tx_seq, p_fcrb->next_seq_expected, p_fcrb->rej_sent, p_fcrb->srej_sent);
1164
1165            if (p_fcrb->srej_sent)
1166            {
1167                /* If SREJ sent, save the frame for later processing as long as it is in sequence */
1168                next_srej = (((BT_HDR *)GKI_getlast(&p_fcrb->srej_rcv_hold_q))->layer_specific + 1) & L2CAP_FCR_SEQ_MODULO;
1169
1170                if ( (tx_seq == next_srej) && (GKI_queue_length(&p_fcrb->srej_rcv_hold_q) < p_ccb->our_cfg.fcr.tx_win_sz) )
1171                {
1172                    /* If user gave us a pool for held rx buffers, use that */
1173                    if (p_ccb->ertm_info.fcr_rx_pool_id != HCI_ACL_POOL_ID)
1174                    {
1175                        BT_HDR *p_buf2;
1176
1177                        /* Adjust offset and len so that control word is copied */
1178                        p_buf->offset -= L2CAP_FCR_OVERHEAD;
1179                        p_buf->len    += L2CAP_FCR_OVERHEAD;
1180
1181                        p_buf2 = l2c_fcr_clone_buf (p_buf, p_buf->offset, p_buf->len, p_ccb->ertm_info.fcr_rx_pool_id);
1182
1183                        if (p_buf2)
1184                        {
1185                            GKI_freebuf (p_buf);
1186                            p_buf = p_buf2;
1187                        }
1188                        p_buf->offset += L2CAP_FCR_OVERHEAD;
1189                        p_buf->len -= L2CAP_FCR_OVERHEAD;
1190                    }
1191                    L2CAP_TRACE_DEBUG ("process_i_frame() Lost: %u  tx_seq:%u  ExpTxSeq %u  Rej: %u  SRej1",
1192                                         num_lost, tx_seq, p_fcrb->next_seq_expected, p_fcrb->rej_sent);
1193
1194                    p_buf->layer_specific = tx_seq;
1195                    GKI_enqueue (&p_fcrb->srej_rcv_hold_q, p_buf);
1196                }
1197                else
1198                {
1199                    L2CAP_TRACE_WARNING ("process_i_frame() CID: 0x%04x  frame dropped in Srej Sent next_srej:%u  hold_q.count:%u  win_sz:%u",
1200                                         p_ccb->local_cid, next_srej, GKI_queue_length(&p_fcrb->srej_rcv_hold_q), p_ccb->our_cfg.fcr.tx_win_sz);
1201
1202                    p_fcrb->rej_after_srej = TRUE;
1203                    GKI_freebuf (p_buf);
1204                }
1205            }
1206            else if (p_fcrb->rej_sent)
1207            {
1208                L2CAP_TRACE_WARNING ("process_i_frame() CID: 0x%04x  Lost: %u  tx_seq:%u  ExpTxSeq %u  Rej: 1  SRej: %u",
1209                                     p_ccb->local_cid, num_lost, tx_seq, p_fcrb->next_seq_expected, p_fcrb->srej_sent);
1210
1211                /* If REJ sent, just drop the frame */
1212                GKI_freebuf (p_buf);
1213            }
1214            else
1215            {
1216                L2CAP_TRACE_DEBUG ("process_i_frame() CID: 0x%04x  tx_seq:%u  ExpTxSeq %u  Rej: %u",
1217                                     p_ccb->local_cid, tx_seq, p_fcrb->next_seq_expected, p_fcrb->rej_sent);
1218
1219                /* If only one lost, we will send SREJ, otherwise we will send REJ */
1220                if (num_lost > 1)
1221                {
1222                    GKI_freebuf (p_buf);
1223                    p_fcrb->rej_sent = TRUE;
1224                    l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_REJ, 0);
1225                }
1226                else
1227                {
1228                    if (!GKI_queue_is_empty(&p_fcrb->srej_rcv_hold_q))
1229                    {
1230                        L2CAP_TRACE_ERROR ("process_i_frame() CID: 0x%04x  sending SREJ tx_seq:%d hold_q.count:%u",
1231                                             p_ccb->local_cid, tx_seq, GKI_queue_length(&p_fcrb->srej_rcv_hold_q));
1232                    }
1233                    p_buf->layer_specific = tx_seq;
1234                    GKI_enqueue (&p_fcrb->srej_rcv_hold_q, p_buf);
1235                    p_fcrb->srej_sent = TRUE;
1236                    l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_SREJ, 0);
1237                }
1238                btu_stop_quick_timer (&p_ccb->fcrb.ack_timer);
1239            }
1240        }
1241        return;
1242    }
1243
1244    /* Seq number is the next expected. Clear possible reject exception in case it occured */
1245    p_fcrb->rej_sent = p_fcrb->srej_sent = FALSE;
1246
1247    /* Adjust the next_seq, so that if the upper layer sends more data in the callback
1248       context, the received frame is acked by an I-frame. */
1249    p_fcrb->next_seq_expected = (tx_seq + 1) & L2CAP_FCR_SEQ_MODULO;
1250
1251    /* If any SAR problem in eRTM mode, spec says disconnect. */
1252    if (!do_sar_reassembly (p_ccb, p_buf, ctrl_word))
1253    {
1254        L2CAP_TRACE_WARNING ("process_i_frame() CID: 0x%04x  reassembly failed", p_ccb->local_cid);
1255        l2cu_disconnect_chnl (p_ccb);
1256        return;
1257    }
1258
1259    /* RR optimization - if peer can still send us more, then start an ACK timer */
1260    num_to_ack = (p_fcrb->next_seq_expected - p_fcrb->last_ack_sent) & L2CAP_FCR_SEQ_MODULO;
1261
1262    if ( (num_to_ack < p_ccb->fcrb.max_held_acks) && (!p_fcrb->local_busy) )
1263        delay_ack = TRUE;
1264
1265    /* We should neve never ack frame if we are not in OPEN state */
1266    if ((num_to_ack != 0) && p_ccb->in_use && (p_ccb->chnl_state == CST_OPEN))
1267    {
1268        /* If no frames are awaiting transmission or are held, send an RR or RNR S-frame for ack */
1269        if (delay_ack)
1270        {
1271            /* If it is the first I frame we did not ack, start ack timer */
1272            if (!p_ccb->fcrb.ack_timer.in_use)
1273            {
1274                btu_start_quick_timer (&p_ccb->fcrb.ack_timer, BTU_TTYPE_L2CAP_FCR_ACK,
1275                                        (L2CAP_FCR_ACK_TOUT*QUICK_TIMER_TICKS_PER_SEC)/1000);
1276            }
1277        }
1278        else if ( ((GKI_queue_is_empty(&p_ccb->xmit_hold_q)) || (l2c_fcr_is_flow_controlled (p_ccb)))
1279               &&  (GKI_queue_is_empty(&p_ccb->fcrb.srej_rcv_hold_q)))
1280        {
1281            if (p_fcrb->local_busy)
1282                l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RNR, 0);
1283            else
1284                l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RR, 0);
1285        }
1286    }
1287}
1288
1289
1290/*******************************************************************************
1291**
1292** Function         process_stream_frame
1293**
1294** Description      This function processes frames in streaming mode
1295**
1296** Returns          -
1297**
1298*******************************************************************************/
1299static void process_stream_frame (tL2C_CCB *p_ccb, BT_HDR *p_buf)
1300{
1301    UINT16      ctrl_word;
1302    UINT16      fcs;
1303    UINT8       *p;
1304    UINT8       tx_seq;
1305
1306    /* Verify FCS if using */
1307    if (p_ccb->bypass_fcs != L2CAP_BYPASS_FCS)
1308    {
1309        p = ((UINT8 *)(p_buf+1)) + p_buf->offset + p_buf->len - L2CAP_FCS_LEN;
1310
1311        /* Extract and drop the FCS from the packet */
1312        STREAM_TO_UINT16 (fcs, p);
1313        p_buf->len -= L2CAP_FCS_LEN;
1314
1315        if (l2c_fcr_rx_get_fcs(p_buf) != fcs)
1316        {
1317            L2CAP_TRACE_WARNING ("Rx L2CAP PDU: CID: 0x%04x  BAD FCS", p_ccb->local_cid);
1318            GKI_freebuf(p_buf);
1319            return;
1320        }
1321    }
1322
1323    /* Get the control word */
1324    p = ((UINT8 *)(p_buf+1)) + p_buf->offset;
1325
1326    STREAM_TO_UINT16 (ctrl_word, p);
1327
1328    p_buf->len    -= L2CAP_FCR_OVERHEAD;
1329    p_buf->offset += L2CAP_FCR_OVERHEAD;
1330
1331    /* Make sure it is an I-frame */
1332    if (ctrl_word & L2CAP_FCR_S_FRAME_BIT)
1333    {
1334        L2CAP_TRACE_WARNING ("Rx L2CAP PDU: CID: 0x%04x  BAD S-frame in streaming mode  ctrl_word: 0x%04x", p_ccb->local_cid, ctrl_word);
1335        GKI_freebuf (p_buf);
1336        return;
1337    }
1338
1339#if BT_TRACE_VERBOSE == TRUE
1340    L2CAP_TRACE_EVENT ("L2CAP eRTM Rx I-frame: cid: 0x%04x  Len: %u  SAR: %-12s  TxSeq: %u  ReqSeq: %u  F: %u",
1341                        p_ccb->local_cid, p_buf->len,
1342                        SAR_types[(ctrl_word & L2CAP_FCR_SAR_BITS) >> L2CAP_FCR_SAR_BITS_SHIFT],
1343                        (ctrl_word & L2CAP_FCR_TX_SEQ_BITS) >> L2CAP_FCR_TX_SEQ_BITS_SHIFT,
1344                        (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT,
1345                        (ctrl_word & L2CAP_FCR_F_BIT) >> L2CAP_FCR_F_BIT_SHIFT);
1346#endif
1347
1348    /* Extract the sequence number */
1349    tx_seq = (ctrl_word & L2CAP_FCR_TX_SEQ_BITS) >> L2CAP_FCR_TX_SEQ_BITS_SHIFT;
1350
1351    /* Check if tx-sequence is the expected one */
1352    if (tx_seq != p_ccb->fcrb.next_seq_expected)
1353    {
1354        L2CAP_TRACE_WARNING ("Rx L2CAP PDU: CID: 0x%04x  Lost frames Exp: %u  Got: %u  p_rx_sdu: 0x%08x",
1355                                p_ccb->local_cid, p_ccb->fcrb.next_seq_expected, tx_seq, p_ccb->fcrb.p_rx_sdu);
1356
1357        /* Lost one or more packets, so flush the SAR queue */
1358        if (p_ccb->fcrb.p_rx_sdu != NULL)
1359        {
1360            GKI_freebuf (p_ccb->fcrb.p_rx_sdu);
1361            p_ccb->fcrb.p_rx_sdu = NULL;
1362        }
1363    }
1364
1365    p_ccb->fcrb.next_seq_expected = (tx_seq + 1) & L2CAP_FCR_SEQ_MODULO;
1366
1367    if (!do_sar_reassembly (p_ccb, p_buf, ctrl_word))
1368    {
1369        /* Some sort of SAR error, so flush the SAR queue */
1370        if (p_ccb->fcrb.p_rx_sdu != NULL)
1371        {
1372            GKI_freebuf (p_ccb->fcrb.p_rx_sdu);
1373            p_ccb->fcrb.p_rx_sdu = NULL;
1374        }
1375    }
1376}
1377
1378
1379/*******************************************************************************
1380**
1381** Function         do_sar_reassembly
1382**
1383** Description      Process SAR bits and re-assemble frame
1384**
1385** Returns          TRUE if all OK, else FALSE
1386**
1387*******************************************************************************/
1388static BOOLEAN do_sar_reassembly (tL2C_CCB *p_ccb, BT_HDR *p_buf, UINT16 ctrl_word)
1389{
1390    tL2C_FCRB   *p_fcrb = &p_ccb->fcrb;
1391    UINT16      sar_type = ctrl_word & L2CAP_FCR_SEG_BITS;
1392    BOOLEAN     packet_ok = TRUE;
1393    UINT8       *p;
1394
1395    /* Check if the SAR state is correct */
1396    if ((sar_type == L2CAP_FCR_UNSEG_SDU) || (sar_type == L2CAP_FCR_START_SDU))
1397    {
1398        if (p_fcrb->p_rx_sdu != NULL)
1399        {
1400            L2CAP_TRACE_WARNING ("SAR - got unexpected unsegmented or start SDU  Expected len: %u  Got so far: %u",
1401                                  p_fcrb->rx_sdu_len, p_fcrb->p_rx_sdu->len);
1402
1403            packet_ok = FALSE;
1404        }
1405        /* Check the length of the packet */
1406        if ( (sar_type == L2CAP_FCR_START_SDU) && (p_buf->len < L2CAP_SDU_LEN_OVERHEAD) )
1407        {
1408            L2CAP_TRACE_WARNING ("SAR start packet too short: %u", p_buf->len);
1409            packet_ok = FALSE;
1410        }
1411    }
1412    else
1413    {
1414        if (p_fcrb->p_rx_sdu == NULL)
1415        {
1416            L2CAP_TRACE_WARNING ("SAR - got unexpected cont or end SDU");
1417            packet_ok = FALSE;
1418        }
1419    }
1420
1421    if ( (packet_ok) && (sar_type != L2CAP_FCR_UNSEG_SDU) )
1422    {
1423        p = ((UINT8 *)(p_buf + 1)) + p_buf->offset;
1424
1425        /* For start SDU packet, extract the SDU length */
1426        if (sar_type == L2CAP_FCR_START_SDU)
1427        {
1428            /* Get the SDU length */
1429            STREAM_TO_UINT16 (p_fcrb->rx_sdu_len, p);
1430            p_buf->offset += 2;
1431            p_buf->len    -= 2;
1432
1433            if (p_fcrb->rx_sdu_len > p_ccb->max_rx_mtu)
1434            {
1435                L2CAP_TRACE_WARNING ("SAR - SDU len: %u  larger than MTU: %u", p_fcrb->rx_sdu_len, p_fcrb->rx_sdu_len);
1436                packet_ok = FALSE;
1437            }
1438            else if ((p_fcrb->p_rx_sdu = (BT_HDR *)GKI_getpoolbuf (p_ccb->ertm_info.user_rx_pool_id)) == NULL)
1439            {
1440                L2CAP_TRACE_ERROR ("SAR - no buffer for SDU start user_rx_pool_id:%d", p_ccb->ertm_info.user_rx_pool_id);
1441                packet_ok = FALSE;
1442            }
1443            else
1444            {
1445                p_fcrb->p_rx_sdu->offset = 4; /* this is the minimal offset required by OBX to process incoming packets */
1446                p_fcrb->p_rx_sdu->len    = 0;
1447            }
1448        }
1449
1450        if (packet_ok)
1451        {
1452            if ((p_fcrb->p_rx_sdu->len + p_buf->len) > p_fcrb->rx_sdu_len)
1453            {
1454                L2CAP_TRACE_ERROR ("SAR - SDU len exceeded  Type: %u   Lengths: %u %u %u",
1455                                    sar_type, p_fcrb->p_rx_sdu->len, p_buf->len, p_fcrb->rx_sdu_len);
1456                packet_ok = FALSE;
1457            }
1458            else if ( (sar_type == L2CAP_FCR_END_SDU) && ((p_fcrb->p_rx_sdu->len + p_buf->len) != p_fcrb->rx_sdu_len) )
1459            {
1460                L2CAP_TRACE_WARNING ("SAR - SDU end rcvd but SDU incomplete: %u %u %u",
1461                                      p_fcrb->p_rx_sdu->len, p_buf->len, p_fcrb->rx_sdu_len);
1462                packet_ok = FALSE;
1463            }
1464            else
1465            {
1466                memcpy (((UINT8 *) (p_fcrb->p_rx_sdu + 1)) + p_fcrb->p_rx_sdu->offset + p_fcrb->p_rx_sdu->len, p, p_buf->len);
1467
1468                p_fcrb->p_rx_sdu->len += p_buf->len;
1469
1470                GKI_freebuf (p_buf);
1471                p_buf = NULL;
1472
1473                if (sar_type == L2CAP_FCR_END_SDU)
1474                {
1475                    p_buf            = p_fcrb->p_rx_sdu;
1476                    p_fcrb->p_rx_sdu = NULL;
1477                }
1478            }
1479        }
1480    }
1481
1482    if (packet_ok == FALSE)
1483    {
1484        GKI_freebuf (p_buf);
1485    }
1486    else if (p_buf != NULL)
1487    {
1488#if (L2CAP_NUM_FIXED_CHNLS > 0)
1489        if (p_ccb->local_cid < L2CAP_BASE_APPL_CID &&
1490            (p_ccb->local_cid >= L2CAP_FIRST_FIXED_CHNL && p_ccb->local_cid <= L2CAP_LAST_FIXED_CHNL))
1491        {
1492            if (l2cb.fixed_reg[p_ccb->local_cid - L2CAP_FIRST_FIXED_CHNL].pL2CA_FixedData_Cb)
1493                (*l2cb.fixed_reg[p_ccb->local_cid - L2CAP_FIRST_FIXED_CHNL].pL2CA_FixedData_Cb)(p_ccb->p_lcb->remote_bd_addr, p_buf);
1494        }
1495        else
1496#endif
1497            l2c_csm_execute (p_ccb, L2CEVT_L2CAP_DATA, p_buf);
1498    }
1499
1500    return (packet_ok);
1501}
1502
1503
1504/*******************************************************************************
1505**
1506** Function         retransmit_i_frames
1507**
1508** Description      This function retransmits i-frames awaiting acks.
1509**
1510** Returns          BOOLEAN - TRUE if retransmitted
1511**
1512*******************************************************************************/
1513static BOOLEAN retransmit_i_frames (tL2C_CCB *p_ccb, UINT8 tx_seq)
1514{
1515    BT_HDR      *p_buf, *p_buf2;
1516    UINT8       *p;
1517    UINT8       buf_seq;
1518    UINT16      ctrl_word;
1519
1520    if ( (GKI_getfirst(&p_ccb->fcrb.waiting_for_ack_q))
1521     &&  (p_ccb->peer_cfg.fcr.max_transmit != 0)
1522     &&  (p_ccb->fcrb.num_tries >= p_ccb->peer_cfg.fcr.max_transmit) )
1523    {
1524        L2CAP_TRACE_EVENT ("Max Tries Exceeded:  (last_acq: %d  CID: 0x%04x  num_tries: %u (max: %u) ack_q_count: %u",
1525                p_ccb->fcrb.last_rx_ack, p_ccb->local_cid, p_ccb->fcrb.num_tries, p_ccb->peer_cfg.fcr.max_transmit,
1526                GKI_queue_length(&p_ccb->fcrb.waiting_for_ack_q));
1527
1528        l2cu_disconnect_chnl (p_ccb);
1529        return (FALSE);
1530    }
1531
1532    /* tx_seq indicates whether to retransmit a specific sequence or all (if == L2C_FCR_RETX_ALL_PKTS) */
1533    if (tx_seq != L2C_FCR_RETX_ALL_PKTS)
1534    {
1535        /* If sending only one, the sequence number tells us which one. Look for it.
1536        */
1537        for (p_buf = (BT_HDR *)GKI_getfirst(&p_ccb->fcrb.waiting_for_ack_q); p_buf; p_buf = (BT_HDR *)GKI_getnext (p_buf))
1538        {
1539            /* Get the old control word */
1540            p = ((UINT8 *) (p_buf+1)) + p_buf->offset + L2CAP_PKT_OVERHEAD;
1541
1542            STREAM_TO_UINT16 (ctrl_word, p);
1543
1544            buf_seq = (ctrl_word & L2CAP_FCR_TX_SEQ_BITS) >> L2CAP_FCR_TX_SEQ_BITS_SHIFT;
1545
1546            L2CAP_TRACE_DEBUG ("retransmit_i_frames()   cur seq: %u  looking for: %u", buf_seq, tx_seq);
1547
1548            if (tx_seq == buf_seq)
1549                break;
1550        }
1551
1552        if (!p_buf)
1553        {
1554            L2CAP_TRACE_ERROR ("retransmit_i_frames() UNKNOWN seq: %u  q_count: %u", tx_seq, GKI_queue_length(&p_ccb->fcrb.waiting_for_ack_q));
1555            return (TRUE);
1556        }
1557    }
1558    else
1559    {
1560
1561        // Iterate though list and flush the amount requested from
1562        // the transmit data queue that satisfy the layer and event conditions.
1563        for (const list_node_t *node = list_begin(p_ccb->p_lcb->link_xmit_data_q);
1564            node != list_end(p_ccb->p_lcb->link_xmit_data_q);
1565            node = list_next(node)) {
1566
1567          BT_HDR *p_buf = (BT_HDR *)list_node(node);
1568            /* Do not flush other CIDs or partial segments */
1569          if ((p_buf->layer_specific == 0) && (p_buf->event == p_ccb->local_cid)) {
1570            list_remove(p_ccb->p_lcb->link_xmit_data_q, p_buf);
1571            GKI_freebuf(p_buf);
1572          }
1573        }
1574
1575        /* Also flush our retransmission queue */
1576        while (!GKI_queue_is_empty(&p_ccb->fcrb.retrans_q))
1577            GKI_freebuf (GKI_dequeue (&p_ccb->fcrb.retrans_q));
1578
1579        p_buf = (BT_HDR *)GKI_getfirst(&p_ccb->fcrb.waiting_for_ack_q);
1580    }
1581
1582    while (p_buf != NULL)
1583    {
1584        p_buf2 = l2c_fcr_clone_buf (p_buf, p_buf->offset, p_buf->len, p_ccb->ertm_info.fcr_tx_pool_id);
1585
1586        if (p_buf2)
1587        {
1588            p_buf2->layer_specific = p_buf->layer_specific;
1589
1590            GKI_enqueue (&p_ccb->fcrb.retrans_q, p_buf2);
1591        }
1592
1593        if ( (tx_seq != L2C_FCR_RETX_ALL_PKTS) || (p_buf2 == NULL) )
1594            break;
1595        else
1596            p_buf = (BT_HDR *)GKI_getnext (p_buf);
1597    }
1598
1599    l2c_link_check_send_pkts (p_ccb->p_lcb, NULL, NULL);
1600
1601    if (GKI_queue_length(&p_ccb->fcrb.waiting_for_ack_q))
1602    {
1603        p_ccb->fcrb.num_tries++;
1604        l2c_fcr_start_timer (p_ccb);
1605    }
1606
1607    return (TRUE);
1608}
1609
1610
1611/*******************************************************************************
1612**
1613** Function         l2c_fcr_get_next_xmit_sdu_seg
1614**
1615** Description      Get the next SDU segment to transmit.
1616**
1617** Returns          pointer to buffer with segment or NULL
1618**
1619*******************************************************************************/
1620BT_HDR *l2c_fcr_get_next_xmit_sdu_seg (tL2C_CCB *p_ccb, UINT16 max_packet_length)
1621{
1622    BOOLEAN     first_seg    = FALSE,       /* The segment is the first part of data  */
1623                mid_seg      = FALSE,       /* The segment is the middle part of data */
1624                last_seg     = FALSE;       /* The segment is the last part of data   */
1625    UINT16      sdu_len = 0;
1626    BT_HDR      *p_buf, *p_xmit;
1627    UINT8       *p;
1628    UINT16      max_pdu = p_ccb->tx_mps /* Needed? - L2CAP_MAX_HEADER_FCS*/;
1629
1630    /* If there is anything in the retransmit queue, that goes first
1631    */
1632    if (GKI_getfirst(&p_ccb->fcrb.retrans_q))
1633    {
1634        p_buf = (BT_HDR *)GKI_dequeue (&p_ccb->fcrb.retrans_q);
1635
1636        /* Update Rx Seq and FCS if we acked some packets while this one was queued */
1637        prepare_I_frame (p_ccb, p_buf, TRUE);
1638
1639        p_buf->event = p_ccb->local_cid;
1640
1641#if L2CAP_CORRUPT_ERTM_PKTS == TRUE
1642        /* Use sdu_len to hold the control word */
1643        p = ((UINT8 *) (p_buf+1)) + p_buf->offset + L2CAP_PKT_OVERHEAD;
1644        STREAM_TO_UINT16 (sdu_len, p);
1645
1646        /* Get out if packet was dropped; just pretend it went out */
1647        if (l2c_corrupt_the_fcr_packet (p_ccb, p_buf, FALSE, sdu_len))
1648            return (NULL);
1649#endif  /* L2CAP_CORRUPT_ERTM_PKTS */
1650
1651#if (L2CAP_ERTM_STATS == TRUE)
1652        p_ccb->fcrb.pkts_retransmitted++;
1653        p_ccb->fcrb.ertm_pkt_counts[0]++;
1654        p_ccb->fcrb.ertm_byte_counts[0] += (p_buf->len - 8);
1655#endif
1656        return (p_buf);
1657    }
1658
1659    /* For BD/EDR controller, max_packet_length is set to 0             */
1660    /* For AMP controller, max_packet_length is set by available blocks */
1661    if ( (max_packet_length > L2CAP_MAX_HEADER_FCS)
1662      && (max_pdu + L2CAP_MAX_HEADER_FCS > max_packet_length) )
1663    {
1664        max_pdu = max_packet_length - L2CAP_MAX_HEADER_FCS;
1665    }
1666
1667    p_buf = (BT_HDR *)GKI_getfirst(&p_ccb->xmit_hold_q);
1668
1669    /* If there is more data than the MPS, it requires segmentation */
1670    if (p_buf->len > max_pdu)
1671    {
1672        /* We are using the "event" field to tell is if we already started segmentation */
1673        if (p_buf->event == 0)
1674        {
1675            first_seg = TRUE;
1676            sdu_len   = p_buf->len;
1677        }
1678        else
1679            mid_seg = TRUE;
1680
1681        /* Get a new buffer and copy the data that can be sent in a PDU */
1682        p_xmit = l2c_fcr_clone_buf (p_buf, L2CAP_MIN_OFFSET + L2CAP_SDU_LEN_OFFSET,
1683                                    max_pdu, p_ccb->ertm_info.fcr_tx_pool_id);
1684
1685        if (p_xmit != NULL)
1686        {
1687            p_buf->event  = p_ccb->local_cid;
1688            p_xmit->event = p_ccb->local_cid;
1689
1690            p_buf->len    -= max_pdu;
1691            p_buf->offset += max_pdu;
1692
1693            /* copy PBF setting */
1694            p_xmit->layer_specific = p_buf->layer_specific;
1695        }
1696        else /* Should never happen if the application has configured buffers correctly */
1697        {
1698            L2CAP_TRACE_ERROR ("L2CAP - cannot get buffer, for segmentation, pool: %u", p_ccb->ertm_info.fcr_tx_pool_id);
1699            return (NULL);
1700        }
1701    }
1702    else    /* Use the original buffer if no segmentation, or the last segment */
1703    {
1704        p_xmit = (BT_HDR *)GKI_dequeue (&p_ccb->xmit_hold_q);
1705
1706        if (p_xmit->event != 0)
1707            last_seg = TRUE;
1708
1709        p_xmit->event = p_ccb->local_cid;
1710    }
1711
1712    /* Step back to add the L2CAP headers */
1713    p_xmit->offset -= (L2CAP_PKT_OVERHEAD + L2CAP_FCR_OVERHEAD);
1714    p_xmit->len    += L2CAP_PKT_OVERHEAD + L2CAP_FCR_OVERHEAD;
1715
1716    if (first_seg)
1717    {
1718        p_xmit->offset -= L2CAP_SDU_LEN_OVERHEAD;
1719        p_xmit->len    += L2CAP_SDU_LEN_OVERHEAD;
1720    }
1721
1722    /* Set the pointer to the beginning of the data */
1723    p = (UINT8 *)(p_xmit + 1) + p_xmit->offset;
1724
1725    /* Now the L2CAP header */
1726
1727    /* Note: if FCS has to be included then the length is recalculated later */
1728    UINT16_TO_STREAM (p, p_xmit->len - L2CAP_PKT_OVERHEAD);
1729
1730    UINT16_TO_STREAM (p, p_ccb->remote_cid);
1731
1732    if (first_seg)
1733    {
1734        /* Skip control word and add SDU length */
1735        p += 2;
1736        UINT16_TO_STREAM (p, sdu_len);
1737
1738        /* We will store the SAR type in layer-specific */
1739        /* layer_specific is shared with flushable flag(bits 0-1), don't clear it */
1740        p_xmit->layer_specific |= L2CAP_FCR_START_SDU;
1741
1742        first_seg = FALSE;
1743    }
1744    else if (mid_seg)
1745        p_xmit->layer_specific |= L2CAP_FCR_CONT_SDU;
1746    else if (last_seg)
1747        p_xmit->layer_specific |= L2CAP_FCR_END_SDU;
1748    else
1749        p_xmit->layer_specific |= L2CAP_FCR_UNSEG_SDU;
1750
1751    prepare_I_frame (p_ccb, p_xmit, FALSE);
1752
1753    if (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_ERTM_MODE)
1754    {
1755        BT_HDR *p_wack = l2c_fcr_clone_buf (p_xmit, HCI_DATA_PREAMBLE_SIZE, p_xmit->len, p_ccb->ertm_info.fcr_tx_pool_id);
1756
1757        if (!p_wack)
1758        {
1759            L2CAP_TRACE_ERROR ("L2CAP - no buffer for xmit cloning, CID: 0x%04x  Pool: %u  Count: %u",
1760                                p_ccb->local_cid, p_ccb->ertm_info.fcr_tx_pool_id,  GKI_poolfreecount(p_ccb->ertm_info.fcr_tx_pool_id));
1761
1762            /* We will not save the FCS in case we reconfigure and change options */
1763            if (p_ccb->bypass_fcs != L2CAP_BYPASS_FCS)
1764                p_xmit->len -= L2CAP_FCS_LEN;
1765
1766            /* Pretend we sent it and it got lost */
1767            GKI_enqueue (&p_ccb->fcrb.waiting_for_ack_q, p_xmit);
1768            return (NULL);
1769        }
1770        else
1771        {
1772#if (L2CAP_ERTM_STATS == TRUE)
1773            /* set timestamp at the end of tx I-frame to get acking delay */
1774            p = ((UINT8 *) (p_wack+1)) + p_wack->offset + p_wack->len;
1775            UINT32_TO_STREAM (p, GKI_get_os_tick_count());
1776#endif
1777            /* We will not save the FCS in case we reconfigure and change options */
1778            if (p_ccb->bypass_fcs != L2CAP_BYPASS_FCS)
1779                p_wack->len -= L2CAP_FCS_LEN;
1780
1781            p_wack->layer_specific = p_xmit->layer_specific;
1782            GKI_enqueue (&p_ccb->fcrb.waiting_for_ack_q, p_wack);
1783        }
1784
1785#if L2CAP_CORRUPT_ERTM_PKTS == TRUE
1786        {
1787            UINT16 ctrl_word;
1788            p = ((UINT8 *) (p_xmit+1)) + p_xmit->offset + L2CAP_PKT_OVERHEAD;
1789            STREAM_TO_UINT16 (ctrl_word, p);
1790
1791            /* Get out if packet was dropped; pretend it was sent */
1792            if (l2c_corrupt_the_fcr_packet (p_ccb, p_xmit, FALSE, ctrl_word))
1793                return (NULL);
1794        }
1795#endif
1796#if (L2CAP_ERTM_STATS == TRUE)
1797        p_ccb->fcrb.ertm_pkt_counts[0]++;
1798        p_ccb->fcrb.ertm_byte_counts[0] += (p_xmit->len - 8);
1799#endif
1800
1801    }
1802
1803    return (p_xmit);
1804}
1805
1806
1807/*******************************************************************************
1808** Configuration negotiation functions
1809**
1810** The following functions are used in negotiating channel modes during
1811** configuration
1812********************************************************************************/
1813
1814/*******************************************************************************
1815**
1816** Function         l2c_fcr_chk_chan_modes
1817**
1818** Description      Validates and adjusts if necessary, the FCR options
1819**                  based on remote EXT features.
1820**
1821**                  Note: This assumes peer EXT Features have been received.
1822**                      Basic mode is used if FCR Options have not been received
1823**
1824** Returns          UINT8 - nonzero if can continue, '0' if no compatible channels
1825**
1826*******************************************************************************/
1827UINT8 l2c_fcr_chk_chan_modes (tL2C_CCB *p_ccb)
1828{
1829    /* Remove nonbasic options that the peer does not support */
1830    if (!(p_ccb->p_lcb->peer_ext_fea & L2CAP_EXTFEA_ENH_RETRANS))
1831        p_ccb->ertm_info.allowed_modes &= ~L2CAP_FCR_CHAN_OPT_ERTM;
1832
1833    if (!(p_ccb->p_lcb->peer_ext_fea & L2CAP_EXTFEA_STREAM_MODE))
1834        p_ccb->ertm_info.allowed_modes &= ~L2CAP_FCR_CHAN_OPT_STREAM;
1835
1836    /* At least one type needs to be set (Basic, ERTM, STM) to continue */
1837    if (!p_ccb->ertm_info.allowed_modes)
1838    {
1839        L2CAP_TRACE_WARNING ("L2CAP - Peer does not support our desired channel types");
1840    }
1841
1842    return (p_ccb->ertm_info.allowed_modes);
1843}
1844
1845/*******************************************************************************
1846**
1847** Function         l2c_fcr_adj_our_req_options
1848**
1849** Description      Validates and sets up the FCR options passed in from
1850**                  L2CA_ConfigReq based on remote device's features.
1851**
1852** Returns          TRUE if no errors, Otherwise FALSE
1853**
1854*******************************************************************************/
1855BOOLEAN l2c_fcr_adj_our_req_options (tL2C_CCB *p_ccb, tL2CAP_CFG_INFO *p_cfg)
1856{
1857    tL2CAP_FCR_OPTS *p_fcr = &p_cfg->fcr;
1858
1859    if (p_fcr->mode != p_ccb->ertm_info.preferred_mode)
1860    {
1861        L2CAP_TRACE_WARNING ("l2c_fcr_adj_our_req_options - preferred_mode (%d), does not match mode (%d)",
1862                            p_ccb->ertm_info.preferred_mode, p_fcr->mode);
1863
1864        /* The preferred mode is passed in through tL2CAP_ERTM_INFO, so override this one */
1865        p_fcr->mode = p_ccb->ertm_info.preferred_mode;
1866    }
1867
1868    /* If upper layer did not request eRTM mode, BASIC must be used */
1869    if (p_ccb->ertm_info.allowed_modes == L2CAP_FCR_CHAN_OPT_BASIC)
1870    {
1871        if (p_cfg->fcr_present && p_fcr->mode != L2CAP_FCR_BASIC_MODE)
1872        {
1873            L2CAP_TRACE_WARNING ("l2c_fcr_adj_our_req_options (mode %d): ERROR: No FCR options set using BASIC mode", p_fcr->mode);
1874        }
1875        p_fcr->mode = L2CAP_FCR_BASIC_MODE;
1876    }
1877
1878    /* Process the FCR options if initial channel bring-up (not a reconfig request)
1879    ** Determine initial channel mode to try based on our options and remote's features
1880    */
1881    if (p_cfg->fcr_present && !(p_ccb->config_done & RECONFIG_FLAG))
1882    {
1883        /* We need to have at least one mode type common with the peer */
1884        if (!l2c_fcr_chk_chan_modes(p_ccb))
1885        {
1886            /* Two channels have incompatible supported types */
1887            l2cu_disconnect_chnl (p_ccb);
1888            return (FALSE);
1889        }
1890
1891        /* Basic is the only common channel mode between the two devices */
1892        else if (p_ccb->ertm_info.allowed_modes == L2CAP_FCR_CHAN_OPT_BASIC)
1893        {
1894            /* We only want to try Basic, so bypass sending the FCR options entirely */
1895            p_cfg->fcr_present = FALSE;
1896            p_cfg->fcs_present = FALSE;             /* Illegal to use FCS option in basic mode */
1897            p_cfg->ext_flow_spec_present = FALSE;   /* Illegal to use extended flow spec in basic mode */
1898        }
1899
1900        /* We have at least one non-basic mode available
1901         * Override mode from available mode options based on preference, if needed
1902         */
1903        else
1904        {
1905            /* If peer does not support STREAMING, try ERTM */
1906            if (p_fcr->mode == L2CAP_FCR_STREAM_MODE && !(p_ccb->ertm_info.allowed_modes & L2CAP_FCR_CHAN_OPT_STREAM))
1907            {
1908                L2CAP_TRACE_DEBUG ("L2C CFG: mode is STREAM, but peer does not support; Try ERTM");
1909                p_fcr->mode = L2CAP_FCR_ERTM_MODE;
1910            }
1911
1912            /* If peer does not support ERTM, try BASIC (will support this if made it here in the code) */
1913            if (p_fcr->mode == L2CAP_FCR_ERTM_MODE && !(p_ccb->ertm_info.allowed_modes & L2CAP_FCR_CHAN_OPT_ERTM))
1914            {
1915                L2CAP_TRACE_DEBUG ("L2C CFG: mode is ERTM, but peer does not support; Try BASIC");
1916                p_fcr->mode = L2CAP_FCR_BASIC_MODE;
1917            }
1918        }
1919
1920        if (p_fcr->mode != L2CAP_FCR_BASIC_MODE)
1921        {
1922            /* MTU must be smaller than buffer size */
1923            if ( (p_cfg->mtu_present) && (p_cfg->mtu > p_ccb->max_rx_mtu) )
1924            {
1925                L2CAP_TRACE_WARNING ("L2CAP - MTU: %u  larger than buf size: %u", p_cfg->mtu, p_ccb->max_rx_mtu);
1926                return (FALSE);
1927            }
1928
1929            /* application want to use the default MPS */
1930            if (p_fcr->mps == L2CAP_DEFAULT_ERM_MPS)
1931            {
1932                p_fcr->mps = L2CAP_MPS_OVER_BR_EDR;
1933            }
1934            /* MPS must be less than MTU */
1935            else if (p_fcr->mps > p_ccb->max_rx_mtu)
1936            {
1937                L2CAP_TRACE_WARNING ("L2CAP - MPS  %u  invalid  MTU: %u", p_fcr->mps, p_ccb->max_rx_mtu);
1938                return (FALSE);
1939            }
1940
1941            /* We always initially read into the HCI buffer pool, so make sure it fits */
1942            if (p_fcr->mps > (L2CAP_MTU_SIZE - L2CAP_MAX_HEADER_FCS))
1943                p_fcr->mps = L2CAP_MTU_SIZE - L2CAP_MAX_HEADER_FCS;
1944        }
1945        else
1946        {
1947            p_cfg->fcs_present = FALSE;             /* Illegal to use FCS option in basic mode */
1948            p_cfg->ext_flow_spec_present = FALSE;   /* Illegal to use extended flow spec in basic mode */
1949        }
1950
1951        p_ccb->our_cfg.fcr = *p_fcr;
1952    }
1953    else    /* Not sure how to send a reconfiguration(??) should fcr be included? */
1954    {
1955        p_ccb->our_cfg.fcr_present = FALSE;
1956    }
1957
1958    return (TRUE);
1959}
1960
1961
1962/*******************************************************************************
1963**
1964** Function         l2c_fcr_adj_monitor_retran_timeout
1965**
1966** Description      Overrides monitor/retrans timer value based on controller
1967**
1968** Returns          None
1969**
1970*******************************************************************************/
1971void l2c_fcr_adj_monitor_retran_timeout (tL2C_CCB *p_ccb)
1972{
1973    /* adjust our monitor/retran timeout */
1974    if (p_ccb->out_cfg_fcr_present)
1975    {
1976        /*
1977        ** if we requestd ERTM or accepted ERTM
1978        ** We may accept ERTM even if we didn't request ERTM, in case of requesting STREAM
1979        */
1980        if ((p_ccb->our_cfg.fcr.mode == L2CAP_FCR_ERTM_MODE)
1981          ||(p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_ERTM_MODE))
1982        {
1983            /* upper layer setting is ignored */
1984            p_ccb->our_cfg.fcr.mon_tout    = L2CAP_MIN_MONITOR_TOUT;
1985            p_ccb->our_cfg.fcr.rtrans_tout = L2CAP_MIN_RETRANS_TOUT;
1986        }
1987        else
1988        {
1989            p_ccb->our_cfg.fcr.mon_tout    = 0;
1990            p_ccb->our_cfg.fcr.rtrans_tout = 0;
1991        }
1992
1993        L2CAP_TRACE_DEBUG ("l2c_fcr_adj_monitor_retran_timeout: mon_tout:%d, rtrans_tout:%d",
1994                             p_ccb->our_cfg.fcr.mon_tout, p_ccb->our_cfg.fcr.rtrans_tout);
1995    }
1996}
1997/*******************************************************************************
1998**
1999** Function         l2c_fcr_adj_our_rsp_options
2000**
2001** Description      Overrides any neccesary FCR options passed in from
2002**                  L2CA_ConfigRsp based on our FCR options.
2003**                  Only makes adjustments if channel is in ERTM mode.
2004**
2005** Returns          None
2006**
2007*******************************************************************************/
2008void l2c_fcr_adj_our_rsp_options (tL2C_CCB *p_ccb, tL2CAP_CFG_INFO *p_cfg)
2009{
2010    /* adjust our monitor/retran timeout */
2011    l2c_fcr_adj_monitor_retran_timeout(p_ccb);
2012
2013    p_cfg->fcr_present = p_ccb->out_cfg_fcr_present;
2014
2015    if (p_cfg->fcr_present)
2016    {
2017// btla-specific ++
2018        /* Temporary - until a better algorithm is implemented */
2019        /* If peer's tx_wnd_sz requires too many buffers for us to support, then adjust it. For now, respond with our own tx_wnd_sz. */
2020        /* Note: peer is not guaranteed to obey our adjustment */
2021        if (p_ccb->peer_cfg.fcr.tx_win_sz > p_ccb->our_cfg.fcr.tx_win_sz)
2022        {
2023            L2CAP_TRACE_DEBUG ("%s: adjusting requested tx_win_sz from %i to %i", __FUNCTION__, p_ccb->peer_cfg.fcr.tx_win_sz, p_ccb->our_cfg.fcr.tx_win_sz);
2024            p_ccb->peer_cfg.fcr.tx_win_sz = p_ccb->our_cfg.fcr.tx_win_sz;
2025        }
2026// btla-specific --
2027
2028        p_cfg->fcr.mode         = p_ccb->peer_cfg.fcr.mode;
2029        p_cfg->fcr.tx_win_sz    = p_ccb->peer_cfg.fcr.tx_win_sz;
2030        p_cfg->fcr.max_transmit = p_ccb->peer_cfg.fcr.max_transmit;
2031        p_cfg->fcr.mps          = p_ccb->peer_cfg.fcr.mps;
2032        p_cfg->fcr.rtrans_tout  = p_ccb->our_cfg.fcr.rtrans_tout;
2033        p_cfg->fcr.mon_tout     = p_ccb->our_cfg.fcr.mon_tout;
2034    }
2035}
2036
2037/*******************************************************************************
2038**
2039** Function         l2c_fcr_renegotiate_chan
2040**
2041** Description      Called upon unsuccessful peer response to config request.
2042**                  If the error is because of the channel mode, it will try
2043**                  to resend using another supported optional channel.
2044**
2045** Returns          TRUE if resent configuration, False if channel matches or
2046**                  cannot match.
2047**
2048*******************************************************************************/
2049BOOLEAN l2c_fcr_renegotiate_chan(tL2C_CCB *p_ccb, tL2CAP_CFG_INFO *p_cfg)
2050{
2051    UINT8   peer_mode = p_ccb->our_cfg.fcr.mode;
2052    BOOLEAN can_renegotiate;
2053
2054    /* Skip if this is a reconfiguration from OPEN STATE or if FCR is not returned */
2055    if (!p_cfg->fcr_present || (p_ccb->config_done & RECONFIG_FLAG))
2056        return (FALSE);
2057
2058    /* Only retry if there are more channel options to try */
2059    if (p_cfg->result == L2CAP_CFG_UNACCEPTABLE_PARAMS)
2060    {
2061        peer_mode = (p_cfg->fcr_present) ? p_cfg->fcr.mode : L2CAP_FCR_BASIC_MODE;
2062
2063        if (p_ccb->our_cfg.fcr.mode != peer_mode)
2064        {
2065
2066            if ((--p_ccb->fcr_cfg_tries) == 0)
2067            {
2068                p_cfg->result = L2CAP_CFG_FAILED_NO_REASON;
2069                L2CAP_TRACE_WARNING ("l2c_fcr_renegotiate_chan (Max retries exceeded)");
2070            }
2071
2072            can_renegotiate = FALSE;
2073
2074            /* Try another supported mode if available based on our last attempted channel */
2075            switch (p_ccb->our_cfg.fcr.mode)
2076            {
2077                /* Our Streaming mode request was unnacceptable; try ERTM or Basic */
2078            case L2CAP_FCR_STREAM_MODE:
2079                /* Peer wants ERTM and we support it */
2080                if ( (peer_mode == L2CAP_FCR_ERTM_MODE) && (p_ccb->ertm_info.allowed_modes & L2CAP_FCR_CHAN_OPT_ERTM) )
2081                {
2082                    L2CAP_TRACE_DEBUG ("l2c_fcr_renegotiate_chan(Trying ERTM)");
2083                    p_ccb->our_cfg.fcr.mode = L2CAP_FCR_ERTM_MODE;
2084                    can_renegotiate = TRUE;
2085                }
2086                else    /* Falls through */
2087
2088            case L2CAP_FCR_ERTM_MODE:
2089                {
2090                    /* We can try basic for any other peer mode if we support it */
2091                    if (p_ccb->ertm_info.allowed_modes & L2CAP_FCR_CHAN_OPT_BASIC)
2092                    {
2093                        L2CAP_TRACE_DEBUG ("l2c_fcr_renegotiate_chan(Trying Basic)");
2094                        can_renegotiate = TRUE;
2095                        p_ccb->our_cfg.fcr.mode = L2CAP_FCR_BASIC_MODE;
2096                    }
2097                }
2098                break;
2099
2100            default:
2101                /* All other scenarios cannot be renegotiated */
2102                break;
2103            }
2104
2105            if (can_renegotiate)
2106            {
2107                p_ccb->our_cfg.fcr_present = TRUE;
2108
2109                if (p_ccb->our_cfg.fcr.mode == L2CAP_FCR_BASIC_MODE)
2110                {
2111                    p_ccb->our_cfg.fcs_present = FALSE;
2112                    p_ccb->our_cfg.ext_flow_spec_present = FALSE;
2113
2114                    /* Basic Mode uses ACL Data Pool, make sure the MTU fits */
2115                    if ( (p_cfg->mtu_present) && (p_cfg->mtu > L2CAP_MTU_SIZE) )
2116                    {
2117                        L2CAP_TRACE_WARNING ("L2CAP - adjust MTU: %u too large", p_cfg->mtu);
2118                        p_cfg->mtu = L2CAP_MTU_SIZE;
2119                    }
2120                }
2121
2122                l2cu_process_our_cfg_req (p_ccb, &p_ccb->our_cfg);
2123                l2cu_send_peer_config_req (p_ccb, &p_ccb->our_cfg);
2124                btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_CFG_TIMEOUT);
2125                return (TRUE);
2126            }
2127        }
2128    }
2129
2130    /* Disconnect if the channels do not match */
2131    if (p_ccb->our_cfg.fcr.mode != peer_mode)
2132    {
2133        L2CAP_TRACE_WARNING ("L2C CFG:  Channels incompatible (local %d, peer %d)",
2134                              p_ccb->our_cfg.fcr.mode, peer_mode);
2135        l2cu_disconnect_chnl (p_ccb);
2136    }
2137
2138    return (FALSE);
2139}
2140
2141
2142/*******************************************************************************
2143**
2144** Function         l2c_fcr_process_peer_cfg_req
2145**
2146** Description      This function is called to process the FCR options passed
2147**                  in the peer's configuration request.
2148**
2149** Returns          UINT8 - L2CAP_PEER_CFG_OK, L2CAP_PEER_CFG_UNACCEPTABLE,
2150**                          or L2CAP_PEER_CFG_DISCONNECT.
2151**
2152*******************************************************************************/
2153UINT8 l2c_fcr_process_peer_cfg_req(tL2C_CCB *p_ccb, tL2CAP_CFG_INFO *p_cfg)
2154{
2155    UINT16 max_retrans_size;
2156    UINT8  fcr_ok = L2CAP_PEER_CFG_OK;
2157
2158    p_ccb->p_lcb->w4_info_rsp = FALSE;      /* Handles T61x SonyEricsson Bug in Info Request */
2159
2160    L2CAP_TRACE_EVENT ("l2c_fcr_process_peer_cfg_req() CFG fcr_present:%d fcr.mode:%d CCB FCR mode:%d preferred: %u allowed:%u",
2161                        p_cfg->fcr_present, p_cfg->fcr.mode, p_ccb->our_cfg.fcr.mode, p_ccb->ertm_info.preferred_mode,
2162                        p_ccb->ertm_info.allowed_modes);
2163
2164    /* If Peer wants basic, we are done (accept it or disconnect) */
2165    if (p_cfg->fcr.mode == L2CAP_FCR_BASIC_MODE)
2166    {
2167        /* If we do not allow basic, disconnect */
2168        if ( !(p_ccb->ertm_info.allowed_modes & L2CAP_FCR_CHAN_OPT_BASIC) )
2169            fcr_ok = L2CAP_PEER_CFG_DISCONNECT;
2170    }
2171
2172    /* Need to negotiate if our modes are not the same */
2173    else if (p_cfg->fcr.mode != p_ccb->ertm_info.preferred_mode)
2174    {
2175        /* If peer wants a mode that we don't support then retry our mode (ex. rtx/flc), OR
2176        ** If we want ERTM and they wanted streaming retry our mode.
2177        ** Note: If we have already determined they support our mode previously
2178        **       from their EXF mask.
2179        */
2180        if ( (((1 << p_cfg->fcr.mode) & L2CAP_FCR_CHAN_OPT_ALL_MASK) == 0)
2181            || (p_ccb->ertm_info.preferred_mode == L2CAP_FCR_ERTM_MODE) )
2182        {
2183            p_cfg->fcr.mode = p_ccb->our_cfg.fcr.mode;
2184            p_cfg->fcr.tx_win_sz = p_ccb->our_cfg.fcr.tx_win_sz;
2185            p_cfg->fcr.max_transmit = p_ccb->our_cfg.fcr.max_transmit;
2186            fcr_ok = L2CAP_PEER_CFG_UNACCEPTABLE;
2187        }
2188
2189        /* If we wanted basic, then try to renegotiate it */
2190        else if (p_ccb->ertm_info.preferred_mode == L2CAP_FCR_BASIC_MODE)
2191        {
2192            p_cfg->fcr.mode = L2CAP_FCR_BASIC_MODE;
2193            p_cfg->fcr.max_transmit = p_cfg->fcr.tx_win_sz = 0;
2194            p_cfg->fcr.rtrans_tout = p_cfg->fcr.mon_tout = p_cfg->fcr.mps = 0;
2195            p_ccb->our_cfg.fcr.rtrans_tout = p_ccb->our_cfg.fcr.mon_tout = p_ccb->our_cfg.fcr.mps = 0;
2196            fcr_ok = L2CAP_PEER_CFG_UNACCEPTABLE;
2197        }
2198
2199        /* Only other valid case is if they want ERTM and we wanted STM which should be
2200           accepted if we support it; otherwise the channel should be disconnected */
2201        else if ( (p_cfg->fcr.mode != L2CAP_FCR_ERTM_MODE)
2202              || !(p_ccb->ertm_info.allowed_modes & L2CAP_FCR_CHAN_OPT_ERTM) )
2203        {
2204            fcr_ok = L2CAP_PEER_CFG_DISCONNECT;
2205        }
2206    }
2207
2208    /* Configuration for FCR channels so make any adjustments and fwd to upper layer */
2209    if (fcr_ok == L2CAP_PEER_CFG_OK)
2210    {
2211        /* by default don't need to send params in the response */
2212        p_ccb->out_cfg_fcr_present = FALSE;
2213
2214        /* Make any needed adjustments for the response to the peer */
2215        if (p_cfg->fcr_present && p_cfg->fcr.mode != L2CAP_FCR_BASIC_MODE)
2216        {
2217            /* Peer desires to bypass FCS check, and streaming or ERTM mode */
2218            if (p_cfg->fcs_present)
2219            {
2220                p_ccb->peer_cfg.fcs = p_cfg->fcs;
2221                p_ccb->peer_cfg_bits |= L2CAP_CH_CFG_MASK_FCS;
2222                if( p_cfg->fcs == L2CAP_CFG_FCS_BYPASS)
2223                    p_ccb->bypass_fcs |= L2CAP_CFG_FCS_PEER;
2224            }
2225
2226            max_retrans_size = GKI_get_pool_bufsize (p_ccb->ertm_info.fcr_tx_pool_id) - sizeof(BT_HDR)
2227                                            - L2CAP_MIN_OFFSET - L2CAP_SDU_LEN_OFFSET - L2CAP_FCS_LEN;
2228
2229            /* Ensure the MPS is not bigger than the MTU */
2230            if ( (p_cfg->fcr.mps == 0) || (p_cfg->fcr.mps > p_ccb->peer_cfg.mtu) )
2231            {
2232                p_cfg->fcr.mps = p_ccb->peer_cfg.mtu;
2233                p_ccb->out_cfg_fcr_present = TRUE;
2234            }
2235
2236            /* Ensure the MPS is not bigger than our retransmission buffer */
2237            if (p_cfg->fcr.mps > max_retrans_size)
2238            {
2239                L2CAP_TRACE_DEBUG("CFG: Overriding MPS to %d (orig %d)", max_retrans_size, p_cfg->fcr.mps);
2240
2241                p_cfg->fcr.mps = max_retrans_size;
2242                p_ccb->out_cfg_fcr_present = TRUE;
2243            }
2244
2245            if (p_cfg->fcr.mode == L2CAP_FCR_ERTM_MODE || p_cfg->fcr.mode == L2CAP_FCR_STREAM_MODE)
2246            {
2247                /* Always respond with FCR ERTM parameters */
2248                p_ccb->out_cfg_fcr_present = TRUE;
2249            }
2250        }
2251
2252        /* Everything ok, so save the peer's adjusted fcr options */
2253        p_ccb->peer_cfg.fcr = p_cfg->fcr;
2254
2255        if (p_cfg->fcr_present)
2256            p_ccb->peer_cfg_bits |= L2CAP_CH_CFG_MASK_FCR;
2257    }
2258    else if (fcr_ok == L2CAP_PEER_CFG_UNACCEPTABLE)
2259    {
2260        /* Allow peer only one retry for mode */
2261        if (p_ccb->peer_cfg_already_rejected)
2262            fcr_ok = L2CAP_PEER_CFG_DISCONNECT;
2263        else
2264            p_ccb->peer_cfg_already_rejected = TRUE;
2265    }
2266
2267    return (fcr_ok);
2268}
2269
2270
2271#if L2CAP_CORRUPT_ERTM_PKTS == TRUE
2272/*******************************************************************************
2273**  Functions used for testing ERTM mode
2274*/
2275/* If FALSE, will also corrupt cid, length, control word, etc. */
2276#ifndef L2CAP_CORR_FCS_ONLY
2277#define L2CAP_CORR_FCS_ONLY TRUE
2278#endif
2279
2280#define L2C_DISP_FRAME_SIZE 16
2281/*******************************************************************************
2282**
2283** Function         l2c_corrupt_the_fcr_packet
2284**
2285** Description      This function is used for testing purposes only.
2286**                  It systematically or randomly corrupts packets used with
2287**                  ERTM channels.
2288**
2289** Returns          BOOLEAN   TRUE if packet was dropped,
2290**                            FALSE if fcs corrupted or no corruption
2291**
2292*******************************************************************************/
2293static BOOLEAN l2c_corrupt_the_fcr_packet (tL2C_CCB *p_ccb, BT_HDR *p_buf,
2294                                           BOOLEAN is_rx, UINT16 ctrl_word)
2295{
2296    tL2C_FCR_TEST_CFG *p_cfg;
2297    UINT32   tc;
2298    UINT8   *p;
2299    UINT32   xx;
2300    char     buf[L2C_DISP_FRAME_SIZE];
2301
2302    if (!p_ccb || !p_ccb->fcrb.test_cb.cfg.in_use)
2303        return FALSE;
2304
2305    /* Prepare bad FCS */
2306    p = ((UINT8 *) (p_buf + 1)) + p_buf->offset;
2307    tc = GKI_get_os_tick_count();
2308    tc ^= p[p_buf->len - 1];
2309    xx = tc % 47;
2310
2311    p_cfg = &p_ccb->fcrb.test_cb.cfg;
2312#if 0
2313    L2CAP_TRACE_DEBUG ("testcfg: type: %d, freq: %d (NRM-0, RDM-1), is_rx: %d, count: %d",
2314        p_cfg->type, p_cfg->freq, p_cfg->is_rx, p_cfg->count);
2315#endif
2316    /* If not time to corrupt get out */
2317    if (p_cfg->freq == L2CAP_FCR_FREQ_RANDOM)
2318    {
2319        if (xx != 0)
2320            return FALSE;
2321    }
2322    else    /* check test criteria before corrupting */
2323    {
2324        if ( (p_cfg->count == 0)
2325          || (p_cfg->is_rx != is_rx)
2326          || ((UINT8)(ctrl_word & L2CAP_FCR_S_FRAME_BIT) != p_cfg->type) )
2327        {
2328            return FALSE;
2329        }
2330
2331        /* Turn off if done */
2332        if (--(p_cfg->count) == 0)
2333        {
2334            p_ccb->fcrb.test_cb.cfg.in_use = FALSE;
2335        }
2336    }
2337
2338#if L2CAP_CORR_FCS_ONLY == TRUE
2339    /* Corrupt the FCS check */
2340    p[p_buf->len - 1] = p[p_buf->len - 2] = 0;
2341#else
2342    /* If made it this far packet needs to be corrupted */
2343    xx = tc % p_buf->len;
2344
2345    /* Make sure the value was changed */
2346    if (p[xx + 1] == 0)
2347        p[xx + 1] = 0x5A;
2348
2349    p[xx] = p[xx] ^ p[xx + 1];
2350
2351#if 1   /* Enable if not wishing to corrupting frame type */
2352    {
2353        UINT8 *p_temp = ((UINT8 *) (p_buf + 1)) + p_buf->offset;
2354        p_temp += L2CAP_PKT_OVERHEAD;
2355        if ((UINT16)((*p_temp) & 0x01) != (ctrl_word & 0x0001))
2356        {
2357            (*p_temp) |= (UINT8)(ctrl_word & 0x0001);
2358        }
2359    }
2360#endif
2361#endif
2362
2363    if (is_rx)
2364    {
2365        if (ctrl_word & L2CAP_FCR_S_FRAME_BIT)
2366            BCM_STRCPY_S(buf, L2C_DISP_FRAME_SIZE, "Rx S-Frame");
2367        else
2368            BCM_STRCPY_S(buf, L2C_DISP_FRAME_SIZE, "Rx I-Frame");
2369    }
2370    else
2371    {
2372        if (ctrl_word & L2CAP_FCR_S_FRAME_BIT)
2373            BCM_STRCPY_S(buf, L2C_DISP_FRAME_SIZE, "Tx S-Frame");
2374        else
2375            BCM_STRCPY_S(buf, L2C_DISP_FRAME_SIZE, "Tx I-Frame");
2376    }
2377
2378    /* Lastly, just drop packet if FCS is not being used or if Tx */
2379    if (!is_rx || p_ccb->bypass_fcs == L2CAP_BYPASS_FCS)
2380    {
2381        L2CAP_TRACE_ERROR ("-=-=-=-=-=-=-=-   Dropping %s packet (0x%04x) tc: %u  Buf Len: %u  xx: %u  count: %d",
2382                        buf, (UINT32)p_buf, tc, p_buf->len, xx, p_cfg->count);
2383        GKI_freebuf(p_buf);
2384        return TRUE;
2385    }
2386    else
2387    {
2388        L2CAP_TRACE_ERROR ("-=-=-=-=-=-=-=-   Corrupting %s packet (0x%04x) tc: %u  Buf Len: %u  xx: %u  count: %d",
2389                        buf, (UINT32)p_buf, tc, p_buf->len, xx, p_cfg->count);
2390    }
2391
2392    return FALSE;
2393}
2394
2395
2396/*******************************************************************************
2397**
2398** Function         L2CA_SetupErtmTest
2399**
2400** Description      This function is used for testing purposes only.
2401**                  It corrupts or drops one or more packets used with ERTM channels.
2402**
2403** Parameters
2404**                  cid - channel ID  (0 uses RFCOMM PSM's CID)
2405**
2406**                  type - type of test to run (L2CAP_FCR_TTYPE_CORR_IFRAMES
2407**                                              L2CAP_FCR_TTYPE_CORR_SFRAME
2408**                                              L2CAP_FCR_TTYPE_STOP_TEST
2409**                                              L2CAP_FCR_TTYPE_GET_CID - returns rfcomm cid only)
2410**
2411**                  is_rx  - TRUE to corrupt Rx packet, FALSE for Tx packet)
2412**
2413**                  freq - L2CAP_FCR_FREQ_RANDOM    (turns on random corruptions/drops)
2414**                         L2CAP_FCR_FREQ_NORMAL    (turns on test with "count" corruptions/drops)
2415**
2416**                  count - number of packets in a row to drop or corrupt
2417**
2418** Returns          CID of channel running test
2419**
2420*******************************************************************************/
2421UINT16 L2CA_SetupErtmTest (UINT16 cid, UINT8 type, BOOLEAN is_rx, UINT8 freq, UINT16 count)
2422{
2423    tL2C_CCB *p_ccb = NULL;
2424    tL2C_CCB *p_temp_ccb;
2425    tL2C_FCR_TEST_CB *p_test_cb;
2426    UINT16 xx;
2427
2428    /* If '0' tests run on top of RFCOMM CID if active */
2429    if (cid == 0)
2430    {
2431        p_temp_ccb = l2cb.ccb_pool;
2432        for (xx = 0; xx < MAX_L2CAP_CHANNELS; xx++, p_temp_ccb++)
2433        {
2434            /* Fixed channels don't have p_rcb's */
2435            if (p_temp_ccb->in_use && p_temp_ccb->p_rcb && p_temp_ccb->p_rcb->psm == BT_PSM_RFCOMM)
2436            {
2437                p_ccb = p_temp_ccb;
2438                cid = L2CAP_BASE_APPL_CID + xx;
2439                break;
2440            }
2441        }
2442    }
2443    else
2444        p_ccb = l2cu_find_ccb_by_cid (NULL, cid);
2445
2446    if (!p_ccb || type == L2CAP_FCR_TTYPE_GET_CID)
2447    {
2448        if (type == L2CAP_FCR_TTYPE_GET_CID)
2449        {
2450            L2CAP_TRACE_API ("L2CA_SetupErtmTest (GET_CID): cid = 0x%04x", cid);
2451        }
2452        return (cid);
2453    }
2454
2455    p_test_cb = &p_ccb->fcrb.test_cb;
2456
2457    /* Turn off the current test */
2458    if (type == L2CAP_FCR_TTYPE_STOP_TEST)
2459    {
2460        if (p_test_cb->cfg.in_use)
2461        {
2462            L2CAP_TRACE_ERROR ("L2CA_SetupErtmTest (OFF): cid 0x%04x", cid);
2463        }
2464        p_test_cb->cfg.in_use = FALSE;
2465        p_test_cb->cfg.count = 0;
2466    }
2467
2468    /* Process the new request */
2469    else if (!p_test_cb->cfg.in_use)
2470    {
2471        /* count must be positive unless random is used */
2472        if (!count && freq != L2CAP_FCR_FREQ_RANDOM)
2473        {
2474            L2CAP_TRACE_ERROR ("L2CA_SetupErtmTest (FAIL): Count = 0, freq = %d", freq);
2475            return (cid);
2476        }
2477
2478        L2CAP_TRACE_ERROR ("L2CA_SetupErtmTest (START): cid 0x%04x, type %d, is_rx %d, freq %d, count %d",
2479                            cid, type, is_rx, freq, count);
2480
2481        p_test_cb->cfg.in_use = TRUE;
2482        p_test_cb->cfg.freq = freq;
2483        p_test_cb->cfg.type = type;
2484        p_test_cb->cfg.is_rx = is_rx;
2485        p_test_cb->cfg.count = count;
2486    }
2487    else /* Test already in progress so ignore */
2488    {
2489        L2CAP_TRACE_ERROR ("L2CA_SetupErtmTest (ignoring): cid 0x%04x, type %d, is_rx %d, freq %d, count %d",
2490                            cid, type, is_rx, freq, count);
2491    }
2492
2493    return (cid);
2494}
2495
2496
2497/*******************************************************************************
2498** The following routines are only used in conjunction with Conformance testing
2499********************************************************************************/
2500
2501/*******************************************************************************
2502**
2503** Function         L2CA_SendPolledSFrame
2504**
2505** Description      This function is used for testing purposes only.
2506**                  It Sends a Polled RR or RNR to the peer
2507**
2508** Parameters
2509**                  cid - channel ID
2510**
2511**                  sup_type - (L2CAP_FCR_SUP_RR or L2CAP_FCR_SUP_RNR)
2512**
2513** Returns          void
2514**
2515*******************************************************************************/
2516void L2CA_SendPolledSFrame (UINT16 cid, UINT16 sup_type)
2517{
2518    tL2C_CCB *p_ccb = l2cu_find_ccb_by_cid (NULL, cid);
2519
2520    if (p_ccb && (sup_type == L2CAP_FCR_SUP_RR || sup_type == L2CAP_FCR_SUP_RNR))
2521    {
2522        l2c_fcr_send_S_frame (p_ccb, sup_type, L2CAP_FCR_P_BIT);
2523    }
2524    else
2525    {
2526        L2CAP_TRACE_ERROR ("L2CA_SendPolledSFrame(ERROR): sup_type %u, p_ccb 0x%07x",
2527                            sup_type, (UINT32)p_ccb);
2528    }
2529}
2530
2531/*******************************************************************************
2532**
2533** Function         l2c_bypass_sframe_packet
2534**
2535** Description      This function is used for testing purposes only.
2536**                  It returns TRUE if S-Frame should be bypassed.
2537**
2538** Returns          void
2539**
2540*******************************************************************************/
2541static BOOLEAN l2c_bypass_sframe_packet (tL2C_CCB *p_ccb)
2542{
2543    if (p_ccb && p_ccb->fcrb.test_cb.cfm.in_use)
2544    {
2545        if (p_ccb->fcrb.test_cb.cfm.skip_sframe_count > 0)
2546        {
2547            L2CAP_TRACE_ERROR ("l2c_bypass_sframe_packet (count %d)",
2548                                p_ccb->fcrb.test_cb.cfm.skip_sframe_count);
2549
2550            if (--p_ccb->fcrb.test_cb.cfm.skip_sframe_count == 0)
2551                p_ccb->fcrb.test_cb.cfm.in_use = FALSE;
2552
2553            /* Bypass sending S-Frame */
2554            return TRUE;
2555        }
2556        else
2557            p_ccb->fcrb.test_cb.cfm.in_use = FALSE;
2558    }
2559
2560    return FALSE;
2561}
2562
2563/*******************************************************************************
2564**
2565** Function         L2CA_BypassSFrame
2566**
2567** Description      This function is used for testing purposes only.
2568**                  It skips sending 'count' S-Frames.
2569**
2570** Parameters
2571**                  cid - channel ID
2572**
2573**                  count - Number of S-Frames to skip sending
2574**
2575** Returns          void
2576**
2577*******************************************************************************/
2578void L2CA_BypassSFrame (UINT16 cid, UINT8 count)
2579{
2580    tL2C_CCB *p_ccb = l2cu_find_ccb_by_cid (NULL, cid);
2581    tL2C_FCR_CFM_TEST_CB *p_test_cb;
2582
2583    if (!p_ccb)
2584    {
2585        L2CAP_TRACE_WARNING ("L2CA_BypassSFrame(ERROR): no p_ccb (0x%07x)", (UINT32)p_ccb);
2586        return;
2587    }
2588
2589    p_test_cb = &p_ccb->fcrb.test_cb.cfm;
2590
2591    /* Initiate test if not active */
2592    if (!p_test_cb->in_use)
2593    {
2594        p_test_cb->in_use = TRUE;
2595        p_test_cb->skip_sframe_count = count;
2596    }
2597    else
2598    {
2599        L2CAP_TRACE_WARNING ("L2CA_BypassSFrame(ERROR): already in use (ignoring...)");
2600    }
2601}
2602
2603#endif  /* L2CAP_CORRUPT_ERTM_PKTS == TRUE */
2604
2605#if (L2CAP_ERTM_STATS == TRUE)
2606/*******************************************************************************
2607**
2608** Function         l2c_fcr_collect_ack_delay
2609**
2610** Description      collect throughput, delay, queue size of waiting ack
2611**
2612** Parameters
2613**                  tL2C_CCB
2614**
2615** Returns          void
2616**
2617*******************************************************************************/
2618static void l2c_fcr_collect_ack_delay (tL2C_CCB *p_ccb, UINT8 num_bufs_acked)
2619{
2620    UINT32  index;
2621    BT_HDR *p_buf;
2622    UINT8  *p;
2623    UINT32  timestamp, delay;
2624    UINT8   xx;
2625    UINT8   str[120];
2626
2627    index = p_ccb->fcrb.ack_delay_avg_index;
2628
2629    /* update sum, max and min of waiting for ack queue size */
2630    p_ccb->fcrb.ack_q_count_avg[index] += p_ccb->fcrb.waiting_for_ack_q.count;
2631
2632    if ( p_ccb->fcrb.waiting_for_ack_q.count > p_ccb->fcrb.ack_q_count_max[index] )
2633        p_ccb->fcrb.ack_q_count_max[index] = p_ccb->fcrb.waiting_for_ack_q.count;
2634
2635    if ( p_ccb->fcrb.waiting_for_ack_q.count < p_ccb->fcrb.ack_q_count_min[index] )
2636        p_ccb->fcrb.ack_q_count_min[index] = p_ccb->fcrb.waiting_for_ack_q.count;
2637
2638    /* update sum, max and min of round trip delay of acking */
2639    p_buf = (BT_HDR *)(p_ccb->fcrb.waiting_for_ack_q.p_first);
2640    for (xx = 0; (xx < num_bufs_acked)&&(p_buf); xx++)
2641    {
2642        /* adding up length of acked I-frames to get throughput */
2643        p_ccb->fcrb.throughput[index] += p_buf->len - 8;
2644
2645        if ( xx == num_bufs_acked - 1 )
2646        {
2647            /* get timestamp from tx I-frame that receiver is acking */
2648            p = ((UINT8 *) (p_buf+1)) + p_buf->offset + p_buf->len;
2649            if (p_ccb->bypass_fcs != L2CAP_BYPASS_FCS)
2650            {
2651                p += L2CAP_FCS_LEN;
2652            }
2653
2654            STREAM_TO_UINT32 (timestamp, p);
2655            delay = GKI_get_os_tick_count() - timestamp;
2656
2657            p_ccb->fcrb.ack_delay_avg[index] += delay;
2658            if ( delay > p_ccb->fcrb.ack_delay_max[index] )
2659                p_ccb->fcrb.ack_delay_max[index] = delay;
2660            if ( delay < p_ccb->fcrb.ack_delay_min[index] )
2661                p_ccb->fcrb.ack_delay_min[index] = delay;
2662        }
2663
2664        p_buf = GKI_getnext(p_buf);
2665    }
2666
2667    p_ccb->fcrb.ack_delay_avg_count++;
2668
2669    /* calculate average and initialize next avg, min and max */
2670    if (p_ccb->fcrb.ack_delay_avg_count > L2CAP_ERTM_STATS_AVG_NUM_SAMPLES)
2671    {
2672        p_ccb->fcrb.ack_delay_avg_count = 0;
2673
2674        p_ccb->fcrb.ack_q_count_avg[index] /= L2CAP_ERTM_STATS_AVG_NUM_SAMPLES;
2675        p_ccb->fcrb.ack_delay_avg[index] /= L2CAP_ERTM_STATS_AVG_NUM_SAMPLES;
2676
2677        /* calculate throughput */
2678        timestamp = GKI_get_os_tick_count();
2679        if (timestamp - p_ccb->fcrb.throughput_start > 0 )
2680            p_ccb->fcrb.throughput[index] /= (timestamp - p_ccb->fcrb.throughput_start);
2681
2682        p_ccb->fcrb.throughput_start = timestamp;
2683
2684        sprintf(str, "[%02u] throughput: %5u, ack_delay avg:%3u, min:%3u, max:%3u, ack_q_count avg:%3u, min:%3u, max:%3u",
2685                index, p_ccb->fcrb.throughput[index],
2686                p_ccb->fcrb.ack_delay_avg[index], p_ccb->fcrb.ack_delay_min[index], p_ccb->fcrb.ack_delay_max[index],
2687                p_ccb->fcrb.ack_q_count_avg[index], p_ccb->fcrb.ack_q_count_min[index], p_ccb->fcrb.ack_q_count_max[index] );
2688
2689        BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC, "%s", str);
2690
2691        index = (index + 1) % L2CAP_ERTM_STATS_NUM_AVG;
2692        p_ccb->fcrb.ack_delay_avg_index = index;
2693
2694        p_ccb->fcrb.ack_q_count_max[index] = 0;
2695        p_ccb->fcrb.ack_q_count_min[index] = 0xFFFFFFFF;
2696        p_ccb->fcrb.ack_q_count_avg[index] = 0;
2697
2698
2699        p_ccb->fcrb.ack_delay_max[index] = 0;
2700        p_ccb->fcrb.ack_delay_min[index] = 0xFFFFFFFF;
2701        p_ccb->fcrb.ack_delay_avg[index] = 0;
2702
2703        p_ccb->fcrb.throughput[index] = 0;
2704    }
2705}
2706#endif
2707
2708
2709
2710