l2c_fcr.c revision c0a87fe60f79ddf41595a30e75a77f43c19cd323
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 <assert.h>
27#include <stdio.h>
28#include <stdlib.h>
29#include <string.h>
30
31#include "bt_types.h"
32#include "gki.h"
33#include "hcimsgs.h"
34#include "l2c_api.h"
35#include "l2c_int.h"
36#include "l2cdefs.h"
37#include "btm_api.h"
38#include "btm_int.h"
39#include "btu.h"
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_ERTM_STATS == TRUE)
98static void l2c_fcr_collect_ack_delay (tL2C_CCB *p_ccb, UINT8 num_bufs_acked);
99#endif
100
101/*******************************************************************************
102**
103** Function         l2c_fcr_updcrc
104**
105** Description      This function computes the CRC using the look-up table.
106**
107** Returns          CRC
108**
109*******************************************************************************/
110static unsigned short l2c_fcr_updcrc(unsigned short icrc, unsigned char *icp, int icnt)
111{
112    register unsigned short crc = icrc;
113    register unsigned char  *cp = icp;
114    register          int   cnt = icnt;
115
116    while (cnt--)
117    {
118        crc = ((crc >> 8) & 0xff) ^ crctab[(crc & 0xff) ^ *cp++];
119    }
120
121    return(crc);
122}
123
124
125/*******************************************************************************
126**
127** Function         l2c_fcr_tx_get_fcs
128**
129** Description      This function computes the CRC for a frame to be TXed.
130**
131** Returns          CRC
132**
133*******************************************************************************/
134static UINT16 l2c_fcr_tx_get_fcs (BT_HDR *p_buf)
135{
136    UINT8   *p = ((UINT8 *) (p_buf + 1)) + p_buf->offset;
137
138    return (l2c_fcr_updcrc (L2CAP_FCR_INIT_CRC, p, p_buf->len));
139}
140
141/*******************************************************************************
142**
143** Function         l2c_fcr_rx_get_fcs
144**
145** Description      This function computes the CRC for a received frame.
146**
147** Returns          CRC
148**
149*******************************************************************************/
150static UINT16 l2c_fcr_rx_get_fcs (BT_HDR *p_buf)
151{
152    UINT8   *p = ((UINT8 *) (p_buf + 1)) + p_buf->offset;
153
154    /* offset points past the L2CAP header, but the CRC check includes it */
155    p -= L2CAP_PKT_OVERHEAD;
156
157    return (l2c_fcr_updcrc (L2CAP_FCR_INIT_CRC, p, p_buf->len + L2CAP_PKT_OVERHEAD));
158}
159
160/*******************************************************************************
161**
162** Function         l2c_fcr_start_timer
163**
164** Description      This function starts the (monitor or retransmission) timer.
165**
166** Returns          -
167**
168*******************************************************************************/
169void l2c_fcr_start_timer (tL2C_CCB *p_ccb)
170{
171    assert(p_ccb != NULL);
172    UINT32  tout;
173
174    /* The timers which are in milliseconds */
175    if (p_ccb->fcrb.wait_ack)
176    {
177        tout = (UINT32)p_ccb->our_cfg.fcr.mon_tout;
178    }
179    else
180    {
181        tout = (UINT32)p_ccb->our_cfg.fcr.rtrans_tout;
182    }
183
184    /* Only start a timer that was not started */
185    if (p_ccb->fcrb.mon_retrans_timer.in_use == 0)
186        btu_start_quick_timer (&p_ccb->fcrb.mon_retrans_timer, BTU_TTYPE_L2CAP_CHNL, tout*QUICK_TIMER_TICKS_PER_SEC/1000);
187}
188
189/*******************************************************************************
190**
191** Function         l2c_fcr_stop_timer
192**
193** Description      This function stops the (monitor or transmission) timer.
194**
195** Returns          -
196**
197*******************************************************************************/
198void l2c_fcr_stop_timer (tL2C_CCB *p_ccb)
199{
200    assert(p_ccb != NULL);
201    if (p_ccb->fcrb.mon_retrans_timer.in_use)
202    {
203        btu_stop_quick_timer (&p_ccb->fcrb.mon_retrans_timer);
204    }
205}
206
207/*******************************************************************************
208**
209** Function         l2c_fcr_cleanup
210**
211** Description      This function cleans up the variable used for flow-control/retrans.
212**
213** Returns          -
214**
215*******************************************************************************/
216void l2c_fcr_cleanup (tL2C_CCB *p_ccb)
217{
218    assert(p_ccb != NULL);
219    tL2C_FCRB *p_fcrb = &p_ccb->fcrb;
220
221    l2c_fcr_stop_timer (p_ccb);
222
223    if (p_fcrb->p_rx_sdu)
224        GKI_freebuf (p_fcrb->p_rx_sdu);
225
226    while (!GKI_queue_is_empty(&p_fcrb->waiting_for_ack_q))
227        GKI_freebuf (GKI_dequeue (&p_fcrb->waiting_for_ack_q));
228
229    while (!GKI_queue_is_empty(&p_fcrb->srej_rcv_hold_q))
230        GKI_freebuf (GKI_dequeue (&p_fcrb->srej_rcv_hold_q));
231
232    while (!GKI_queue_is_empty(&p_fcrb->retrans_q))
233        GKI_freebuf (GKI_dequeue (&p_fcrb->retrans_q));
234
235    btu_stop_quick_timer (&p_fcrb->ack_timer);
236    btu_stop_quick_timer (&p_ccb->fcrb.mon_retrans_timer);
237
238#if (L2CAP_ERTM_STATS == TRUE)
239    if ( (p_ccb->local_cid >= L2CAP_BASE_APPL_CID) && (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_ERTM_MODE) )
240    {
241        UINT32  dur = GKI_get_os_tick_count() - p_ccb->fcrb.connect_tick_count;
242        char    *p_str = (char *)GKI_getbuf(120);
243        UINT16  i;
244        UINT32  throughput_avg, ack_delay_avg, ack_q_count_avg;
245
246        BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC,
247                   "---  L2CAP ERTM  Stats for CID: 0x%04x   Duration: %08ums", p_ccb->local_cid, dur);
248        BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC,
249                   "Retransmissions:%08u Times Flow Controlled:%08u Retrans Touts:%08u Ack Touts:%08u",
250                    p_ccb->fcrb.pkts_retransmitted, p_ccb->fcrb.xmit_window_closed, p_ccb->fcrb.retrans_touts, p_ccb->fcrb.xmit_ack_touts);
251        BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC,
252                   "Times there is less than 2 packets in controller when flow controlled:%08u", p_ccb->fcrb.controller_idle);
253        BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC,
254                   "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 );
255        if (p_str)
256        {
257            sprintf(p_str, "Sent Pkts:%08u Bytes:%10u(%06u/sec) RR:%08u REJ:%08u RNR:%08u SREJ:%08u",
258                p_ccb->fcrb.ertm_pkt_counts[0], p_ccb->fcrb.ertm_byte_counts[0],
259                (dur >= 10 ? (p_ccb->fcrb.ertm_byte_counts[0] * 100) / (dur / 10) : 0),
260                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]);
261
262            BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC, "%s", p_str);
263
264            sprintf(p_str, "Rcvd Pkts:%08u Bytes:%10u(%06u/sec) RR:%08u REJ:%08u RNR:%08u SREJ:%08u",
265                p_ccb->fcrb.ertm_pkt_counts[1], p_ccb->fcrb.ertm_byte_counts[1],
266                (dur >= 10 ? (p_ccb->fcrb.ertm_byte_counts[1] * 100) / (dur / 10) : 0),
267                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]);
268
269            BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC, "%s", p_str);
270
271            throughput_avg  = 0;
272            ack_delay_avg   = 0;
273            ack_q_count_avg = 0;
274
275            for (i = 0; i < L2CAP_ERTM_STATS_NUM_AVG; i++ )
276            {
277                if (i == p_ccb->fcrb.ack_delay_avg_index )
278                {
279                    BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC,
280                           "[%02u] collecting data ...", i );
281                    continue;
282                }
283
284                sprintf(p_str, "[%02u] throughput: %5u, ack_delay avg:%3u, min:%3u, max:%3u, ack_q_count avg:%3u, min:%3u, max:%3u",
285                        i, p_ccb->fcrb.throughput[i],
286                        p_ccb->fcrb.ack_delay_avg[i], p_ccb->fcrb.ack_delay_min[i], p_ccb->fcrb.ack_delay_max[i],
287                        p_ccb->fcrb.ack_q_count_avg[i], p_ccb->fcrb.ack_q_count_min[i], p_ccb->fcrb.ack_q_count_max[i] );
288
289                BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC, "%s", p_str);
290
291                throughput_avg  += p_ccb->fcrb.throughput[i];
292                ack_delay_avg   += p_ccb->fcrb.ack_delay_avg[i];
293                ack_q_count_avg += p_ccb->fcrb.ack_q_count_avg[i];
294            }
295
296            throughput_avg  /= (L2CAP_ERTM_STATS_NUM_AVG - 1);
297            ack_delay_avg   /= (L2CAP_ERTM_STATS_NUM_AVG - 1);
298            ack_q_count_avg /= (L2CAP_ERTM_STATS_NUM_AVG - 1);
299
300            BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC,
301                   "throughput_avg: %8u (kbytes/sec), ack_delay_avg: %8u ms, ack_q_count_avg: %8u",
302                    throughput_avg, ack_delay_avg, ack_q_count_avg );
303
304            GKI_freebuf(p_str);
305        }
306
307        BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC,
308                   "---");
309    }
310#endif
311
312    memset (p_fcrb, 0, sizeof (tL2C_FCRB));
313}
314
315/*******************************************************************************
316**
317** Function         l2c_fcr_clone_buf
318**
319** Description      This function allocates and copies requested part of a buffer
320**                  at a new-offset.
321**
322** Returns          pointer to new buffer
323**
324*******************************************************************************/
325BT_HDR *l2c_fcr_clone_buf (BT_HDR *p_buf, UINT16 new_offset, UINT16 no_of_bytes, UINT8 pool)
326{
327    assert(p_buf != NULL);
328    BT_HDR *p_buf2;
329
330    /* If using the common pool, should be at least 10% free. */
331    if ( (pool == HCI_ACL_POOL_ID) && (GKI_poolutilization (pool) > 90) )
332    {
333        L2CAP_TRACE_ERROR ("L2CAP - failed to clone buffer on HCI_ACL_POOL_ID Utilization: %u", GKI_poolutilization(pool));
334        return (NULL);
335    }
336
337    if ((p_buf2 = (BT_HDR *)GKI_getpoolbuf(pool)) != NULL)
338    {
339        UINT16    pool_buf_size = GKI_get_pool_bufsize (pool);
340
341        /* Make sure buffer fits into buffer pool */
342        if ((no_of_bytes + sizeof(BT_HDR) + new_offset) > pool_buf_size)
343        {
344            L2CAP_TRACE_ERROR("##### l2c_fcr_clone_buf (NumBytes %d) -> Exceeds poolsize %d [bytes %d + BT_HDR %d + offset %d]",
345                               (no_of_bytes + sizeof(BT_HDR) + new_offset),
346                               pool_buf_size, no_of_bytes, sizeof(BT_HDR),
347                               new_offset);
348
349            GKI_freebuf(p_buf2);
350            return (NULL);
351        }
352
353        p_buf2->offset = new_offset;
354        p_buf2->len    = no_of_bytes;
355
356        memcpy (((UINT8 *)(p_buf2 + 1)) + p_buf2->offset,
357                ((UINT8 *)(p_buf + 1))  + p_buf->offset,
358                no_of_bytes);
359    }
360    else
361    {
362        L2CAP_TRACE_ERROR ("L2CAP - failed to clone buffer, Pool: %u  Count: %u", pool,  GKI_poolfreecount(pool));
363    }
364
365    return (p_buf2);
366}
367
368/*******************************************************************************
369**
370** Function         l2c_fcr_is_flow_controlled
371**
372** Description      This function checks if the CCB is flow controlled by peer.
373**
374** Returns          The control word
375**
376*******************************************************************************/
377BOOLEAN l2c_fcr_is_flow_controlled (tL2C_CCB *p_ccb)
378{
379    assert(p_ccb != NULL);
380    if (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_ERTM_MODE)
381    {
382        /* Check if remote side flowed us off or the transmit window is full */
383        if ( (p_ccb->fcrb.remote_busy == TRUE)
384         ||  (GKI_queue_length(&p_ccb->fcrb.waiting_for_ack_q) >= p_ccb->peer_cfg.fcr.tx_win_sz) )
385        {
386#if (L2CAP_ERTM_STATS == TRUE)
387            if (!GKI_queue_is_empty(&p_ccb->xmit_hold_q))
388            {
389                p_ccb->fcrb.xmit_window_closed++;
390
391                if ((p_ccb->p_lcb->sent_not_acked < 2)&&(l2cb.controller_xmit_window > 0))
392                    p_ccb->fcrb.controller_idle++;
393            }
394#endif
395            return (TRUE);
396        }
397    }
398    return (FALSE);
399}
400
401/*******************************************************************************
402**
403** Function         prepare_I_frame
404**
405** Description      This function sets the FCR variables in an I-frame that is
406**                  about to be sent to HCI for transmission. This may be the
407**                  first time the I-frame is sent, or a retransmission
408**
409** Returns          -
410**
411*******************************************************************************/
412static void prepare_I_frame (tL2C_CCB *p_ccb, BT_HDR *p_buf, BOOLEAN is_retransmission)
413{
414    assert(p_ccb != NULL);
415    assert(p_buf != NULL);
416    tL2C_FCRB   *p_fcrb = &p_ccb->fcrb;
417    UINT8       *p;
418    UINT16      fcs;
419    UINT16      ctrl_word;
420    BOOLEAN     set_f_bit = p_fcrb->send_f_rsp;
421
422    p_fcrb->send_f_rsp = FALSE;
423
424    if (is_retransmission)
425    {
426        /* Get the old control word and clear out the old req_seq and F bits */
427        p = ((UINT8 *) (p_buf+1)) + p_buf->offset + L2CAP_PKT_OVERHEAD;
428
429        STREAM_TO_UINT16 (ctrl_word, p);
430
431        ctrl_word  &= ~(L2CAP_FCR_REQ_SEQ_BITS + L2CAP_FCR_F_BIT);
432    }
433    else
434    {
435        ctrl_word  = p_buf->layer_specific & L2CAP_FCR_SEG_BITS;                /* SAR bits */
436        ctrl_word |= (p_fcrb->next_tx_seq << L2CAP_FCR_TX_SEQ_BITS_SHIFT);      /* Tx Seq */
437
438        p_fcrb->next_tx_seq = (p_fcrb->next_tx_seq + 1) & L2CAP_FCR_SEQ_MODULO;
439    }
440
441    /* Set the F-bit and reqseq only if using re-transmission mode */
442    if (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_ERTM_MODE)
443    {
444        if (set_f_bit)
445            ctrl_word |= L2CAP_FCR_F_BIT;
446
447        ctrl_word |= (p_fcrb->next_seq_expected) << L2CAP_FCR_REQ_SEQ_BITS_SHIFT;
448
449        p_fcrb->last_ack_sent = p_ccb->fcrb.next_seq_expected;
450
451        if (p_ccb->fcrb.ack_timer.in_use)
452            btu_stop_quick_timer (&p_ccb->fcrb.ack_timer);
453    }
454
455    /* Set the control word */
456    p = ((UINT8 *) (p_buf+1)) + p_buf->offset + L2CAP_PKT_OVERHEAD;
457
458    UINT16_TO_STREAM (p, ctrl_word);
459
460    /* Compute the FCS and add to the end of the buffer if not bypassed */
461    if (p_ccb->bypass_fcs != L2CAP_BYPASS_FCS)
462    {
463        /* length field in l2cap header has to include FCS length */
464        p = ((UINT8 *) (p_buf+1)) + p_buf->offset;
465        UINT16_TO_STREAM (p, p_buf->len + L2CAP_FCS_LEN - L2CAP_PKT_OVERHEAD);
466
467        /* Calculate the FCS */
468        fcs = l2c_fcr_tx_get_fcs(p_buf);
469
470        /* Point to the end of the buffer and put the FCS there */
471        p = ((UINT8 *) (p_buf+1)) + p_buf->offset + p_buf->len;
472
473        UINT16_TO_STREAM (p, fcs);
474
475        p_buf->len += L2CAP_FCS_LEN;
476    }
477
478#if BT_TRACE_VERBOSE == TRUE
479    if (is_retransmission)
480    {
481        L2CAP_TRACE_EVENT ("L2CAP eRTM ReTx I-frame  CID: 0x%04x  Len: %u  SAR: %s  TxSeq: %u  ReqSeq: %u  F: %u",
482                            p_ccb->local_cid, p_buf->len,
483                            SAR_types[(ctrl_word & L2CAP_FCR_SAR_BITS) >> L2CAP_FCR_SAR_BITS_SHIFT],
484                            (ctrl_word & L2CAP_FCR_TX_SEQ_BITS) >> L2CAP_FCR_TX_SEQ_BITS_SHIFT,
485                            (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT,
486                            (ctrl_word & L2CAP_FCR_F_BIT) >> L2CAP_FCR_F_BIT_SHIFT);
487    }
488    else
489    {
490        L2CAP_TRACE_EVENT ("L2CAP eRTM Tx I-frame CID: 0x%04x  Len: %u  SAR: %-12s  TxSeq: %u  ReqSeq: %u  F: %u",
491                            p_ccb->local_cid, p_buf->len,
492                            SAR_types[(ctrl_word & L2CAP_FCR_SAR_BITS) >> L2CAP_FCR_SAR_BITS_SHIFT],
493                            (ctrl_word & L2CAP_FCR_TX_SEQ_BITS) >> L2CAP_FCR_TX_SEQ_BITS_SHIFT,
494                            (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT,
495                            (ctrl_word & L2CAP_FCR_F_BIT) >> L2CAP_FCR_F_BIT_SHIFT);
496    }
497#endif
498
499    /* Start the retransmission timer if not already running */
500    if (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_ERTM_MODE)
501        l2c_fcr_start_timer (p_ccb);
502}
503
504/*******************************************************************************
505**
506** Function         l2c_fcr_send_S_frame
507**
508** Description      This function formats and sends an S-frame for transmission.
509**
510** Returns          -
511**
512*******************************************************************************/
513void l2c_fcr_send_S_frame (tL2C_CCB *p_ccb, UINT16 function_code, UINT16 pf_bit)
514{
515    assert(p_ccb != NULL);
516    BT_HDR      *p_buf;
517    UINT8       *p;
518    UINT16      ctrl_word;
519    UINT16      fcs;
520
521    if ((!p_ccb->in_use) || (p_ccb->chnl_state != CST_OPEN))
522        return;
523
524#if (L2CAP_ERTM_STATS == TRUE)
525     p_ccb->fcrb.s_frames_sent[function_code]++;
526#endif
527
528    if (pf_bit == L2CAP_FCR_P_BIT)
529    {
530        p_ccb->fcrb.wait_ack = TRUE;
531
532        l2c_fcr_stop_timer (p_ccb);         /* Restart the monitor timer */
533        l2c_fcr_start_timer (p_ccb);
534    }
535
536    /* Create the control word to use */
537    ctrl_word = (function_code << L2CAP_FCR_SUP_SHIFT) | L2CAP_FCR_S_FRAME_BIT;
538    ctrl_word |= (p_ccb->fcrb.next_seq_expected << L2CAP_FCR_REQ_SEQ_BITS_SHIFT);
539    ctrl_word |= pf_bit;
540
541    if ((p_buf = (BT_HDR *)GKI_getpoolbuf (L2CAP_CMD_POOL_ID)) != NULL)
542    {
543        p_buf->offset = HCI_DATA_PREAMBLE_SIZE;
544        p_buf->len    = L2CAP_PKT_OVERHEAD + L2CAP_FCR_OVERHEAD;
545
546        /* Set the pointer to the beginning of the data */
547        p = (UINT8 *)(p_buf + 1) + p_buf->offset;
548
549        /* Put in the L2CAP header */
550        UINT16_TO_STREAM (p, L2CAP_FCR_OVERHEAD + L2CAP_FCS_LEN);
551        UINT16_TO_STREAM (p, p_ccb->remote_cid);
552        UINT16_TO_STREAM (p, ctrl_word);
553
554        /* Compute the FCS and add to the end of the buffer if not bypassed */
555        if (p_ccb->bypass_fcs != L2CAP_BYPASS_FCS)
556        {
557            fcs = l2c_fcr_tx_get_fcs (p_buf);
558
559            UINT16_TO_STREAM (p, fcs);
560            p_buf->len += L2CAP_FCS_LEN;
561        }
562        else /* rewrite the length without FCS length */
563        {
564            p -= 6;
565            UINT16_TO_STREAM (p, L2CAP_FCR_OVERHEAD);
566        }
567
568        /* Now, the HCI transport header */
569        p_buf->layer_specific = L2CAP_NON_FLUSHABLE_PKT;
570        l2cu_set_acl_hci_header (p_buf, p_ccb);
571
572#if BT_TRACE_VERBOSE == TRUE
573        if ((((ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT) == 1)
574         || (((ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT) == 3))
575        {
576            L2CAP_TRACE_WARNING ("L2CAP eRTM Tx S-frame  CID: 0x%04x  ctrlword: 0x%04x  Type: %s  ReqSeq: %u  P: %u  F: %u",
577                            p_ccb->local_cid, ctrl_word,
578                            SUP_types[(ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT],
579                            (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT,
580                            (ctrl_word & L2CAP_FCR_P_BIT) >> L2CAP_FCR_P_BIT_SHIFT,
581                            (ctrl_word & L2CAP_FCR_F_BIT) >> L2CAP_FCR_F_BIT_SHIFT);
582            L2CAP_TRACE_WARNING ("                  Buf Len: %u", p_buf->len);
583        }
584        else
585        {
586            L2CAP_TRACE_EVENT ("L2CAP eRTM Tx S-frame  CID: 0x%04x  ctrlword: 0x%04x  Type: %s  ReqSeq: %u  P: %u  F: %u",
587                            p_ccb->local_cid, ctrl_word,
588                            SUP_types[(ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT],
589                            (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT,
590                            (ctrl_word & L2CAP_FCR_P_BIT) >> L2CAP_FCR_P_BIT_SHIFT,
591                            (ctrl_word & L2CAP_FCR_F_BIT) >> L2CAP_FCR_F_BIT_SHIFT);
592            L2CAP_TRACE_EVENT ("                  Buf Len: %u", p_buf->len);
593        }
594#endif  /* BT_TRACE_VERBOSE */
595
596        l2c_link_check_send_pkts (p_ccb->p_lcb, NULL, p_buf);
597
598        p_ccb->fcrb.last_ack_sent = p_ccb->fcrb.next_seq_expected;
599
600        if (p_ccb->fcrb.ack_timer.in_use)
601            btu_stop_quick_timer (&p_ccb->fcrb.ack_timer);
602    }
603    else
604    {
605        L2CAP_TRACE_ERROR ("l2c_fcr_send_S_frame(No Resources) cid 0x%04x, Type: 0x%4x",
606                             p_ccb->local_cid, function_code);
607    }
608}
609
610
611/*******************************************************************************
612**
613** Function         l2c_fcr_proc_pdu
614**
615** Description      This function is the entry point for processing of a
616**                  received PDU when in flow control and/or retransmission modes.
617**
618** Returns          -
619**
620*******************************************************************************/
621void l2c_fcr_proc_pdu (tL2C_CCB *p_ccb, BT_HDR *p_buf)
622{
623    assert(p_ccb != NULL);
624    assert(p_buf != NULL);
625    UINT8       *p;
626    UINT16      fcs;
627    UINT16      min_pdu_len;
628    UINT16      ctrl_word;
629
630    /* Check the length */
631    min_pdu_len = (p_ccb->bypass_fcs == L2CAP_BYPASS_FCS) ?
632                  (UINT16)L2CAP_FCR_OVERHEAD : (UINT16)(L2CAP_FCS_LEN + L2CAP_FCR_OVERHEAD);
633
634    if (p_buf->len < min_pdu_len)
635    {
636        L2CAP_TRACE_WARNING ("Rx L2CAP PDU: CID: 0x%04x  Len too short: %u", p_ccb->local_cid, p_buf->len);
637        GKI_freebuf (p_buf);
638        return;
639    }
640
641    if (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_STREAM_MODE)
642    {
643        process_stream_frame (p_ccb, p_buf);
644        return;
645    }
646
647#if BT_TRACE_VERBOSE == TRUE
648    /* Get the control word */
649    p = ((UINT8 *)(p_buf+1)) + p_buf->offset;
650    STREAM_TO_UINT16 (ctrl_word, p);
651
652    if (ctrl_word & L2CAP_FCR_S_FRAME_BIT)
653    {
654        if ((((ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT) == 1)
655         || (((ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT) == 3))
656        {
657            /* REJ or SREJ */
658            L2CAP_TRACE_WARNING ("L2CAP eRTM Rx S-frame: cid: 0x%04x  Len: %u  Type: %s  ReqSeq: %u  P: %u  F: %u",
659                            p_ccb->local_cid, p_buf->len,
660                            SUP_types[(ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT],
661                            (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT,
662                            (ctrl_word & L2CAP_FCR_P_BIT) >> L2CAP_FCR_P_BIT_SHIFT,
663                            (ctrl_word & L2CAP_FCR_F_BIT) >> L2CAP_FCR_F_BIT_SHIFT);
664        }
665        else
666        {
667            L2CAP_TRACE_EVENT ("L2CAP eRTM Rx S-frame: cid: 0x%04x  Len: %u  Type: %s  ReqSeq: %u  P: %u  F: %u",
668                            p_ccb->local_cid, p_buf->len,
669                            SUP_types[(ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT],
670                            (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT,
671                            (ctrl_word & L2CAP_FCR_P_BIT) >> L2CAP_FCR_P_BIT_SHIFT,
672                            (ctrl_word & L2CAP_FCR_F_BIT) >> L2CAP_FCR_F_BIT_SHIFT);
673        }
674    }
675    else
676    {
677        L2CAP_TRACE_EVENT ("L2CAP eRTM Rx I-frame: cid: 0x%04x  Len: %u  SAR: %-12s  TxSeq: %u  ReqSeq: %u  F: %u",
678                            p_ccb->local_cid, p_buf->len,
679                            SAR_types[(ctrl_word & L2CAP_FCR_SAR_BITS) >> L2CAP_FCR_SAR_BITS_SHIFT],
680                            (ctrl_word & L2CAP_FCR_TX_SEQ_BITS) >> L2CAP_FCR_TX_SEQ_BITS_SHIFT,
681                            (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT,
682                            (ctrl_word & L2CAP_FCR_F_BIT) >> L2CAP_FCR_F_BIT_SHIFT);
683    }
684
685    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",
686                        p_ccb->fcrb.next_tx_seq, p_ccb->fcrb.last_rx_ack, p_ccb->fcrb.next_seq_expected,
687                        p_ccb->fcrb.last_ack_sent, GKI_queue_length(&p_ccb->fcrb.waiting_for_ack_q), p_ccb->fcrb.num_tries);
688
689#endif /* BT_TRACE_VERBOSE */
690
691    /* Verify FCS if using */
692    if (p_ccb->bypass_fcs != L2CAP_BYPASS_FCS)
693    {
694        p = ((UINT8 *)(p_buf+1)) + p_buf->offset + p_buf->len - L2CAP_FCS_LEN;
695
696        /* Extract and drop the FCS from the packet */
697        STREAM_TO_UINT16 (fcs, p);
698        p_buf->len -= L2CAP_FCS_LEN;
699
700        if (l2c_fcr_rx_get_fcs(p_buf) != fcs)
701        {
702            L2CAP_TRACE_WARNING ("Rx L2CAP PDU: CID: 0x%04x  BAD FCS", p_ccb->local_cid);
703            GKI_freebuf(p_buf);
704            return;
705        }
706    }
707
708    /* Get the control word */
709    p = ((UINT8 *)(p_buf+1)) + p_buf->offset;
710
711    STREAM_TO_UINT16 (ctrl_word, p);
712
713    p_buf->len    -= L2CAP_FCR_OVERHEAD;
714    p_buf->offset += L2CAP_FCR_OVERHEAD;
715
716    /* If we had a poll bit outstanding, check if we got a final response */
717    if (p_ccb->fcrb.wait_ack)
718    {
719        /* If final bit not set, ignore the frame unless it is a polled S-frame */
720        if ( !(ctrl_word & L2CAP_FCR_F_BIT) )
721        {
722            if ( (ctrl_word & L2CAP_FCR_P_BIT) && (ctrl_word & L2CAP_FCR_S_FRAME_BIT) )
723            {
724                if (p_ccb->fcrb.srej_sent)
725                    l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_SREJ, L2CAP_FCR_F_BIT);
726                else if (p_ccb->fcrb.local_busy)
727                    l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RNR, L2CAP_FCR_F_BIT);
728                else
729                    l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RR, L2CAP_FCR_F_BIT);
730
731                /* Got a poll while in wait_ack state, so re-start our timer with 1-second */
732                /* This is a small optimization... the monitor timer is 12 secs, but we saw */
733                /* that if the other side sends us a poll when we are waiting for a final,  */
734                /* then it speeds up recovery significantly if we poll him back soon after his poll. */
735                btu_start_quick_timer (&p_ccb->fcrb.mon_retrans_timer, BTU_TTYPE_L2CAP_CHNL, QUICK_TIMER_TICKS_PER_SEC);
736            }
737            GKI_freebuf (p_buf);
738            return;
739        }
740
741        p_ccb->fcrb.wait_ack  = FALSE;
742
743        /* P and F are mutually exclusive */
744        if (ctrl_word & L2CAP_FCR_S_FRAME_BIT)
745            ctrl_word &= ~L2CAP_FCR_P_BIT;
746
747        if (GKI_queue_is_empty(&p_ccb->fcrb.waiting_for_ack_q))
748            p_ccb->fcrb.num_tries = 0;
749
750        l2c_fcr_stop_timer (p_ccb);
751    }
752    else
753    {
754        /* Otherwise, ensure the final bit is ignored */
755        ctrl_word &= ~L2CAP_FCR_F_BIT;
756    }
757
758    /* Process receive sequence number */
759    if (!process_reqseq (p_ccb, ctrl_word))
760    {
761        GKI_freebuf (p_buf);
762        return;
763    }
764
765     /* Process based on whether it is an S-frame or an I-frame */
766    if (ctrl_word & L2CAP_FCR_S_FRAME_BIT)
767        process_s_frame (p_ccb, p_buf, ctrl_word);
768    else
769        process_i_frame (p_ccb, p_buf, ctrl_word, FALSE);
770
771    /* Return if the channel got disconnected by a bad packet or max retransmissions */
772    if ( (!p_ccb->in_use) || (p_ccb->chnl_state != CST_OPEN) )
773        return;
774
775    /* If we have some buffers held while doing SREJ, and SREJ has cleared, process them now */
776    if ( (!p_ccb->fcrb.local_busy) && (!p_ccb->fcrb.srej_sent) && (!GKI_queue_is_empty(&p_ccb->fcrb.srej_rcv_hold_q)))
777    {
778        BUFFER_Q temp_q = p_ccb->fcrb.srej_rcv_hold_q;
779
780        GKI_init_q (&p_ccb->fcrb.srej_rcv_hold_q);
781
782        while ((p_buf = (BT_HDR *)GKI_dequeue (&temp_q)) != NULL)
783        {
784            if (p_ccb->in_use && (p_ccb->chnl_state == CST_OPEN))
785            {
786                /* Get the control word */
787                p = ((UINT8 *)(p_buf+1)) + p_buf->offset - L2CAP_FCR_OVERHEAD;
788
789                STREAM_TO_UINT16 (ctrl_word, p);
790
791                L2CAP_TRACE_DEBUG ("l2c_fcr_proc_pdu() CID: 0x%04x  Process Buffer from SREJ_Hold_Q   TxSeq: %u  Expected_Seq: %u",
792                                    p_ccb->local_cid, (ctrl_word & L2CAP_FCR_TX_SEQ_BITS) >> L2CAP_FCR_TX_SEQ_BITS_SHIFT,
793                                    p_ccb->fcrb.next_seq_expected);
794
795                /* Process the SREJ held I-frame, but do not send an RR for each individual frame */
796                process_i_frame (p_ccb, p_buf, ctrl_word, TRUE);
797            }
798            else
799                GKI_freebuf (p_buf);
800
801            /* If more frames were lost during SREJ, send a REJ */
802            if (p_ccb->fcrb.rej_after_srej)
803            {
804                p_ccb->fcrb.rej_after_srej = FALSE;
805                p_ccb->fcrb.rej_sent       = TRUE;
806
807                l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_REJ, 0);
808            }
809        }
810
811        /* Now, if needed, send one RR for the whole held queue */
812        if ( (!p_ccb->fcrb.local_busy) && (!p_ccb->fcrb.rej_sent) && (!p_ccb->fcrb.srej_sent)
813         &&  (p_ccb->fcrb.next_seq_expected != p_ccb->fcrb.last_ack_sent) )
814            l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RR, 0);
815        else
816        {
817            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",
818                                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,
819                                p_ccb->fcrb.last_ack_sent);
820        }
821    }
822
823    /* If a window has opened, check if we can send any more packets */
824    if ( (!GKI_queue_is_empty(&p_ccb->fcrb.retrans_q) || !GKI_queue_is_empty(&p_ccb->xmit_hold_q))
825      && (p_ccb->fcrb.wait_ack == FALSE)
826      && (l2c_fcr_is_flow_controlled (p_ccb) == FALSE) )
827    {
828        l2c_link_check_send_pkts (p_ccb->p_lcb, NULL, NULL);
829    }
830}
831
832/*******************************************************************************
833**
834** Function         l2c_fcr_proc_tout
835**
836** Description      Handle a timeout. We should be in error recovery state.
837**
838** Returns          -
839**
840*******************************************************************************/
841void l2c_fcr_proc_tout (tL2C_CCB *p_ccb)
842{
843    assert(p_ccb != NULL);
844    L2CAP_TRACE_DEBUG ("l2c_fcr_proc_tout:  CID: 0x%04x  num_tries: %u (max: %u)  wait_ack: %u  ack_q_count: %u",
845                        p_ccb->local_cid, p_ccb->fcrb.num_tries, p_ccb->peer_cfg.fcr.max_transmit,
846                        p_ccb->fcrb.wait_ack, GKI_queue_length(&p_ccb->fcrb.waiting_for_ack_q));
847
848#if (L2CAP_ERTM_STATS == TRUE)
849    p_ccb->fcrb.retrans_touts++;
850#endif
851
852    if ( (p_ccb->peer_cfg.fcr.max_transmit != 0) && (++p_ccb->fcrb.num_tries > p_ccb->peer_cfg.fcr.max_transmit) )
853    {
854        l2cu_disconnect_chnl (p_ccb);
855    }
856    else
857    {
858        if (!p_ccb->fcrb.srej_sent && !p_ccb->fcrb.rej_sent)
859        {
860            if (p_ccb->fcrb.local_busy)
861                l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RNR, L2CAP_FCR_P_BIT);
862            else
863                l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RR, L2CAP_FCR_P_BIT);
864        }
865    }
866}
867
868
869/*******************************************************************************
870**
871** Function         l2c_fcr_proc_ack_tout
872**
873** Description      Send RR/RNR if we have not acked I frame
874**
875** Returns          -
876**
877*******************************************************************************/
878void l2c_fcr_proc_ack_tout (tL2C_CCB *p_ccb)
879{
880    assert(p_ccb != NULL);
881    L2CAP_TRACE_DEBUG ("l2c_fcr_proc_ack_tout:  CID: 0x%04x State: %u  Wack:%u  Rq:%d  Acked:%d", p_ccb->local_cid,
882                        p_ccb->chnl_state, p_ccb->fcrb.wait_ack, p_ccb->fcrb.next_seq_expected, p_ccb->fcrb.last_ack_sent);
883
884    if ( (p_ccb->chnl_state == CST_OPEN) && (!p_ccb->fcrb.wait_ack)
885      && (p_ccb->fcrb.last_ack_sent != p_ccb->fcrb.next_seq_expected) )
886    {
887#if (L2CAP_ERTM_STATS == TRUE)
888        p_ccb->fcrb.xmit_ack_touts++;
889#endif
890        if (p_ccb->fcrb.local_busy)
891            l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RNR, 0);
892        else
893            l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RR, 0);
894    }
895}
896
897
898/*******************************************************************************
899**
900** Function         process_reqseq
901**
902** Description      Handle receive sequence number
903**
904** Returns          -
905**
906*******************************************************************************/
907static BOOLEAN process_reqseq (tL2C_CCB *p_ccb, UINT16 ctrl_word)
908{
909    assert(p_ccb != NULL);
910    tL2C_FCRB   *p_fcrb = &p_ccb->fcrb;
911    UINT8       req_seq, num_bufs_acked, xx;
912    UINT16      ls;
913    UINT16      full_sdus_xmitted;
914
915    /* Receive sequence number does not ack anything for SREJ with P-bit set to zero */
916    if ( (ctrl_word & L2CAP_FCR_S_FRAME_BIT)
917     &&  ((ctrl_word & L2CAP_FCR_SUP_BITS) == (L2CAP_FCR_SUP_SREJ << L2CAP_FCR_SUP_SHIFT))
918     &&  ((ctrl_word & L2CAP_FCR_P_BIT) == 0) )
919    {
920        /* If anything still waiting for ack, restart the timer if it was stopped */
921        if (!GKI_queue_is_empty(&p_fcrb->waiting_for_ack_q))
922            l2c_fcr_start_timer (p_ccb);
923
924        return (TRUE);
925    }
926
927    /* Extract the receive sequence number from the control word */
928    req_seq = (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT;
929
930    num_bufs_acked = (req_seq - p_fcrb->last_rx_ack) & L2CAP_FCR_SEQ_MODULO;
931
932    /* Verify the request sequence is in range before proceeding */
933    if (num_bufs_acked > GKI_queue_length(&p_fcrb->waiting_for_ack_q))
934    {
935        /* The channel is closed if ReqSeq is not in range */
936        L2CAP_TRACE_WARNING ("L2CAP eRTM Frame BAD Req_Seq - ctrl_word: 0x%04x  req_seq 0x%02x  last_rx_ack: 0x%02x  QCount: %u",
937                               ctrl_word, req_seq, p_fcrb->last_rx_ack, GKI_queue_length(&p_fcrb->waiting_for_ack_q));
938
939        l2cu_disconnect_chnl (p_ccb);
940        return (FALSE);
941    }
942
943    p_fcrb->last_rx_ack = req_seq;
944
945    /* Now we can release all acknowledged frames, and restart the retransmission timer if needed */
946    if (num_bufs_acked != 0)
947    {
948        p_fcrb->num_tries = 0;
949        full_sdus_xmitted = 0;
950
951#if (L2CAP_ERTM_STATS == TRUE)
952        l2c_fcr_collect_ack_delay (p_ccb, num_bufs_acked);
953#endif
954
955        for (xx = 0; xx < num_bufs_acked; xx++)
956        {
957            ls = ((BT_HDR *)(GKI_getfirst(&p_fcrb->waiting_for_ack_q)))->layer_specific & L2CAP_FCR_SAR_BITS;
958
959            if ( (ls == L2CAP_FCR_UNSEG_SDU) || (ls == L2CAP_FCR_END_SDU) )
960                full_sdus_xmitted++;
961
962            GKI_freebuf (GKI_dequeue (&p_fcrb->waiting_for_ack_q));
963        }
964
965        /* If we are still in a wait_ack state, do not mess with the timer */
966        if (!p_ccb->fcrb.wait_ack)
967            l2c_fcr_stop_timer (p_ccb);
968
969        /* Check if we need to call the "packet_sent" callback */
970        if ( (p_ccb->p_rcb) && (p_ccb->p_rcb->api.pL2CA_TxComplete_Cb) && (full_sdus_xmitted) )
971        {
972            /* Special case for eRTM, if all packets sent, send 0xFFFF */
973            if (GKI_queue_is_empty(&p_fcrb->waiting_for_ack_q) && (GKI_queue_is_empty(&p_ccb->xmit_hold_q)))
974                full_sdus_xmitted = 0xFFFF;
975
976            (*p_ccb->p_rcb->api.pL2CA_TxComplete_Cb)(p_ccb->local_cid, full_sdus_xmitted);
977        }
978    }
979
980    /* If anything still waiting for ack, restart the timer if it was stopped */
981    if (!GKI_queue_is_empty(&p_fcrb->waiting_for_ack_q))
982        l2c_fcr_start_timer (p_ccb);
983
984    return (TRUE);
985}
986
987
988/*******************************************************************************
989**
990** Function         process_s_frame
991**
992** Description      Process an S frame
993**
994** Returns          -
995**
996*******************************************************************************/
997static void process_s_frame (tL2C_CCB *p_ccb, BT_HDR *p_buf, UINT16 ctrl_word)
998{
999    assert(p_ccb != NULL);
1000    assert(p_buf != NULL);
1001
1002    tL2C_FCRB   *p_fcrb      = &p_ccb->fcrb;
1003    UINT16      s_frame_type = (ctrl_word & L2CAP_FCR_SUP_BITS) >> L2CAP_FCR_SUP_SHIFT;
1004    BOOLEAN     remote_was_busy;
1005    BOOLEAN     all_ok = TRUE;
1006
1007    if (p_buf->len != 0)
1008    {
1009        L2CAP_TRACE_WARNING ("Incorrect S-frame Length (%d)", p_buf->len);
1010    }
1011
1012    L2CAP_TRACE_DEBUG ("process_s_frame ctrl_word 0x%04x fcrb_remote_busy:%d", ctrl_word, p_fcrb->remote_busy);
1013
1014#if (L2CAP_ERTM_STATS == TRUE)
1015    p_ccb->fcrb.s_frames_rcvd[s_frame_type]++;
1016#endif
1017
1018    if (ctrl_word & L2CAP_FCR_P_BIT)
1019    {
1020        p_fcrb->rej_sent   = FALSE;             /* After checkpoint, we can send anoher REJ */
1021        p_fcrb->send_f_rsp = TRUE;              /* Set a flag in case an I-frame is pending */
1022    }
1023
1024    switch (s_frame_type)
1025    {
1026    case L2CAP_FCR_SUP_RR:
1027        remote_was_busy     = p_fcrb->remote_busy;
1028        p_fcrb->remote_busy = FALSE;
1029
1030        if ( (ctrl_word & L2CAP_FCR_F_BIT) || (remote_was_busy) )
1031            all_ok = retransmit_i_frames (p_ccb, L2C_FCR_RETX_ALL_PKTS);
1032        break;
1033
1034    case L2CAP_FCR_SUP_REJ:
1035        p_fcrb->remote_busy = FALSE;
1036        all_ok = retransmit_i_frames (p_ccb, L2C_FCR_RETX_ALL_PKTS);
1037        break;
1038
1039    case L2CAP_FCR_SUP_RNR:
1040        p_fcrb->remote_busy = TRUE;
1041        l2c_fcr_stop_timer (p_ccb);
1042        break;
1043
1044    case L2CAP_FCR_SUP_SREJ:
1045        p_fcrb->remote_busy = FALSE;
1046        all_ok = retransmit_i_frames (p_ccb, (UINT8)((ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT));
1047        break;
1048    }
1049
1050    if (all_ok)
1051    {
1052        /* If polled, we need to respond with F-bit. Note, we may have sent a I-frame with the F-bit */
1053        if (p_fcrb->send_f_rsp)
1054        {
1055            if (p_fcrb->srej_sent)
1056                l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_SREJ, L2CAP_FCR_F_BIT);
1057            else if (p_fcrb->local_busy)
1058                l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RNR, L2CAP_FCR_F_BIT);
1059            else
1060                l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RR, L2CAP_FCR_F_BIT);
1061
1062            p_fcrb->send_f_rsp = FALSE;
1063        }
1064    }
1065    else
1066    {
1067        L2CAP_TRACE_DEBUG ("process_s_frame hit_max_retries");
1068    }
1069
1070    GKI_freebuf (p_buf);
1071}
1072
1073
1074/*******************************************************************************
1075**
1076** Function         process_i_frame
1077**
1078** Description      Process an I frame
1079**
1080** Returns          -
1081**
1082*******************************************************************************/
1083static void process_i_frame (tL2C_CCB *p_ccb, BT_HDR *p_buf, UINT16 ctrl_word, BOOLEAN delay_ack)
1084{
1085    assert(p_ccb != NULL);
1086    assert(p_buf != NULL);
1087
1088    tL2C_FCRB   *p_fcrb = &p_ccb->fcrb;
1089    UINT8       tx_seq, num_lost, num_to_ack, next_srej;
1090
1091    /* If we were doing checkpoint recovery, first retransmit all unacked I-frames */
1092    if (ctrl_word & L2CAP_FCR_F_BIT)
1093    {
1094        if (!retransmit_i_frames (p_ccb, L2C_FCR_RETX_ALL_PKTS))
1095        {
1096            GKI_freebuf(p_buf);
1097            return;
1098        }
1099    }
1100
1101#if (L2CAP_ERTM_STATS == TRUE)
1102    p_ccb->fcrb.ertm_pkt_counts[1]++;
1103    p_ccb->fcrb.ertm_byte_counts[1] += p_buf->len;
1104#endif
1105
1106    /* Extract the sequence number */
1107    tx_seq = (ctrl_word & L2CAP_FCR_TX_SEQ_BITS) >> L2CAP_FCR_TX_SEQ_BITS_SHIFT;
1108
1109    /* If we have flow controlled the peer, ignore any bad I-frames from him */
1110    if ( (tx_seq != p_fcrb->next_seq_expected) && (p_fcrb->local_busy) )
1111    {
1112        L2CAP_TRACE_WARNING ("Dropping bad I-Frame since we flowed off, tx_seq:%u", tx_seq);
1113        l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RNR, 0);
1114        GKI_freebuf(p_buf);
1115        return;
1116    }
1117
1118    /* If there are no free buffers in the user Rx queue, drop the  */
1119    /* received buffer now before we update any sequence numbers    */
1120    if (GKI_poolfreecount (p_ccb->ertm_info.user_rx_pool_id) == 0)
1121    {
1122        L2CAP_TRACE_WARNING ("L2CAP CID: 0x%04x  Dropping I-Frame seq: %u  User RX Pool: %u  (Size: %u)  has no free buffers!!",
1123                              p_ccb->local_cid, tx_seq, p_ccb->ertm_info.user_rx_pool_id,
1124                              GKI_poolcount (p_ccb->ertm_info.user_rx_pool_id));
1125        GKI_freebuf(p_buf);
1126        return;
1127    }
1128
1129    /* Check if tx-sequence is the expected one */
1130    if (tx_seq != p_fcrb->next_seq_expected)
1131    {
1132        num_lost = (tx_seq - p_fcrb->next_seq_expected) & L2CAP_FCR_SEQ_MODULO;
1133
1134        /* Is the frame a duplicate ? If so, just drop it */
1135        if (num_lost >= p_ccb->our_cfg.fcr.tx_win_sz)
1136        {
1137            /* Duplicate - simply drop it */
1138            L2CAP_TRACE_WARNING ("process_i_frame() Dropping Duplicate Frame tx_seq:%u  ExpectedTxSeq %u", tx_seq, p_fcrb->next_seq_expected);
1139            GKI_freebuf(p_buf);
1140        }
1141        else
1142        {
1143            L2CAP_TRACE_WARNING ("process_i_frame() CID: 0x%04x  Lost: %u  tx_seq:%u  ExpTxSeq %u  Rej: %u  SRej: %u",
1144                                 p_ccb->local_cid, num_lost, tx_seq, p_fcrb->next_seq_expected, p_fcrb->rej_sent, p_fcrb->srej_sent);
1145
1146            if (p_fcrb->srej_sent)
1147            {
1148                /* If SREJ sent, save the frame for later processing as long as it is in sequence */
1149                next_srej = (((BT_HDR *)GKI_getlast(&p_fcrb->srej_rcv_hold_q))->layer_specific + 1) & L2CAP_FCR_SEQ_MODULO;
1150
1151                if ( (tx_seq == next_srej) && (GKI_queue_length(&p_fcrb->srej_rcv_hold_q) < p_ccb->our_cfg.fcr.tx_win_sz) )
1152                {
1153                    /* If user gave us a pool for held rx buffers, use that */
1154                    if (p_ccb->ertm_info.fcr_rx_pool_id != HCI_ACL_POOL_ID)
1155                    {
1156                        BT_HDR *p_buf2;
1157
1158                        /* Adjust offset and len so that control word is copied */
1159                        p_buf->offset -= L2CAP_FCR_OVERHEAD;
1160                        p_buf->len    += L2CAP_FCR_OVERHEAD;
1161
1162                        p_buf2 = l2c_fcr_clone_buf (p_buf, p_buf->offset, p_buf->len, p_ccb->ertm_info.fcr_rx_pool_id);
1163
1164                        if (p_buf2)
1165                        {
1166                            GKI_freebuf (p_buf);
1167                            p_buf = p_buf2;
1168                        }
1169                        p_buf->offset += L2CAP_FCR_OVERHEAD;
1170                        p_buf->len -= L2CAP_FCR_OVERHEAD;
1171                    }
1172                    L2CAP_TRACE_DEBUG ("process_i_frame() Lost: %u  tx_seq:%u  ExpTxSeq %u  Rej: %u  SRej1",
1173                                         num_lost, tx_seq, p_fcrb->next_seq_expected, p_fcrb->rej_sent);
1174
1175                    p_buf->layer_specific = tx_seq;
1176                    GKI_enqueue (&p_fcrb->srej_rcv_hold_q, p_buf);
1177                }
1178                else
1179                {
1180                    L2CAP_TRACE_WARNING ("process_i_frame() CID: 0x%04x  frame dropped in Srej Sent next_srej:%u  hold_q.count:%u  win_sz:%u",
1181                                         p_ccb->local_cid, next_srej, GKI_queue_length(&p_fcrb->srej_rcv_hold_q), p_ccb->our_cfg.fcr.tx_win_sz);
1182
1183                    p_fcrb->rej_after_srej = TRUE;
1184                    GKI_freebuf (p_buf);
1185                }
1186            }
1187            else if (p_fcrb->rej_sent)
1188            {
1189                L2CAP_TRACE_WARNING ("process_i_frame() CID: 0x%04x  Lost: %u  tx_seq:%u  ExpTxSeq %u  Rej: 1  SRej: %u",
1190                                     p_ccb->local_cid, num_lost, tx_seq, p_fcrb->next_seq_expected, p_fcrb->srej_sent);
1191
1192                /* If REJ sent, just drop the frame */
1193                GKI_freebuf (p_buf);
1194            }
1195            else
1196            {
1197                L2CAP_TRACE_DEBUG ("process_i_frame() CID: 0x%04x  tx_seq:%u  ExpTxSeq %u  Rej: %u",
1198                                     p_ccb->local_cid, tx_seq, p_fcrb->next_seq_expected, p_fcrb->rej_sent);
1199
1200                /* If only one lost, we will send SREJ, otherwise we will send REJ */
1201                if (num_lost > 1)
1202                {
1203                    GKI_freebuf (p_buf);
1204                    p_fcrb->rej_sent = TRUE;
1205                    l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_REJ, 0);
1206                }
1207                else
1208                {
1209                    if (!GKI_queue_is_empty(&p_fcrb->srej_rcv_hold_q))
1210                    {
1211                        L2CAP_TRACE_ERROR ("process_i_frame() CID: 0x%04x  sending SREJ tx_seq:%d hold_q.count:%u",
1212                                             p_ccb->local_cid, tx_seq, GKI_queue_length(&p_fcrb->srej_rcv_hold_q));
1213                    }
1214                    p_buf->layer_specific = tx_seq;
1215                    GKI_enqueue (&p_fcrb->srej_rcv_hold_q, p_buf);
1216                    p_fcrb->srej_sent = TRUE;
1217                    l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_SREJ, 0);
1218                }
1219                btu_stop_quick_timer (&p_ccb->fcrb.ack_timer);
1220            }
1221        }
1222        return;
1223    }
1224
1225    /* Seq number is the next expected. Clear possible reject exception in case it occured */
1226    p_fcrb->rej_sent = p_fcrb->srej_sent = FALSE;
1227
1228    /* Adjust the next_seq, so that if the upper layer sends more data in the callback
1229       context, the received frame is acked by an I-frame. */
1230    p_fcrb->next_seq_expected = (tx_seq + 1) & L2CAP_FCR_SEQ_MODULO;
1231
1232    /* If any SAR problem in eRTM mode, spec says disconnect. */
1233    if (!do_sar_reassembly (p_ccb, p_buf, ctrl_word))
1234    {
1235        L2CAP_TRACE_WARNING ("process_i_frame() CID: 0x%04x  reassembly failed", p_ccb->local_cid);
1236        l2cu_disconnect_chnl (p_ccb);
1237        return;
1238    }
1239
1240    /* RR optimization - if peer can still send us more, then start an ACK timer */
1241    num_to_ack = (p_fcrb->next_seq_expected - p_fcrb->last_ack_sent) & L2CAP_FCR_SEQ_MODULO;
1242
1243    if ( (num_to_ack < p_ccb->fcrb.max_held_acks) && (!p_fcrb->local_busy) )
1244        delay_ack = TRUE;
1245
1246    /* We should neve never ack frame if we are not in OPEN state */
1247    if ((num_to_ack != 0) && p_ccb->in_use && (p_ccb->chnl_state == CST_OPEN))
1248    {
1249        /* If no frames are awaiting transmission or are held, send an RR or RNR S-frame for ack */
1250        if (delay_ack)
1251        {
1252            /* If it is the first I frame we did not ack, start ack timer */
1253            if (!p_ccb->fcrb.ack_timer.in_use)
1254            {
1255                btu_start_quick_timer (&p_ccb->fcrb.ack_timer, BTU_TTYPE_L2CAP_FCR_ACK,
1256                                        (L2CAP_FCR_ACK_TOUT*QUICK_TIMER_TICKS_PER_SEC)/1000);
1257            }
1258        }
1259        else if ( ((GKI_queue_is_empty(&p_ccb->xmit_hold_q)) || (l2c_fcr_is_flow_controlled (p_ccb)))
1260               &&  (GKI_queue_is_empty(&p_ccb->fcrb.srej_rcv_hold_q)))
1261        {
1262            if (p_fcrb->local_busy)
1263                l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RNR, 0);
1264            else
1265                l2c_fcr_send_S_frame (p_ccb, L2CAP_FCR_SUP_RR, 0);
1266        }
1267    }
1268}
1269
1270
1271/*******************************************************************************
1272**
1273** Function         process_stream_frame
1274**
1275** Description      This function processes frames in streaming mode
1276**
1277** Returns          -
1278**
1279*******************************************************************************/
1280static void process_stream_frame (tL2C_CCB *p_ccb, BT_HDR *p_buf)
1281{
1282    assert(p_ccb != NULL);
1283    assert(p_buf != NULL);
1284
1285    UINT16      ctrl_word;
1286    UINT16      fcs;
1287    UINT8       *p;
1288    UINT8       tx_seq;
1289
1290    /* Verify FCS if using */
1291    if (p_ccb->bypass_fcs != L2CAP_BYPASS_FCS)
1292    {
1293        p = ((UINT8 *)(p_buf+1)) + p_buf->offset + p_buf->len - L2CAP_FCS_LEN;
1294
1295        /* Extract and drop the FCS from the packet */
1296        STREAM_TO_UINT16 (fcs, p);
1297        p_buf->len -= L2CAP_FCS_LEN;
1298
1299        if (l2c_fcr_rx_get_fcs(p_buf) != fcs)
1300        {
1301            L2CAP_TRACE_WARNING ("Rx L2CAP PDU: CID: 0x%04x  BAD FCS", p_ccb->local_cid);
1302            GKI_freebuf(p_buf);
1303            return;
1304        }
1305    }
1306
1307    /* Get the control word */
1308    p = ((UINT8 *)(p_buf+1)) + p_buf->offset;
1309
1310    STREAM_TO_UINT16 (ctrl_word, p);
1311
1312    p_buf->len    -= L2CAP_FCR_OVERHEAD;
1313    p_buf->offset += L2CAP_FCR_OVERHEAD;
1314
1315    /* Make sure it is an I-frame */
1316    if (ctrl_word & L2CAP_FCR_S_FRAME_BIT)
1317    {
1318        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);
1319        GKI_freebuf (p_buf);
1320        return;
1321    }
1322
1323#if BT_TRACE_VERBOSE == TRUE
1324    L2CAP_TRACE_EVENT ("L2CAP eRTM Rx I-frame: cid: 0x%04x  Len: %u  SAR: %-12s  TxSeq: %u  ReqSeq: %u  F: %u",
1325                        p_ccb->local_cid, p_buf->len,
1326                        SAR_types[(ctrl_word & L2CAP_FCR_SAR_BITS) >> L2CAP_FCR_SAR_BITS_SHIFT],
1327                        (ctrl_word & L2CAP_FCR_TX_SEQ_BITS) >> L2CAP_FCR_TX_SEQ_BITS_SHIFT,
1328                        (ctrl_word & L2CAP_FCR_REQ_SEQ_BITS) >> L2CAP_FCR_REQ_SEQ_BITS_SHIFT,
1329                        (ctrl_word & L2CAP_FCR_F_BIT) >> L2CAP_FCR_F_BIT_SHIFT);
1330#endif
1331
1332    /* Extract the sequence number */
1333    tx_seq = (ctrl_word & L2CAP_FCR_TX_SEQ_BITS) >> L2CAP_FCR_TX_SEQ_BITS_SHIFT;
1334
1335    /* Check if tx-sequence is the expected one */
1336    if (tx_seq != p_ccb->fcrb.next_seq_expected)
1337    {
1338        L2CAP_TRACE_WARNING ("Rx L2CAP PDU: CID: 0x%04x  Lost frames Exp: %u  Got: %u  p_rx_sdu: 0x%08x",
1339                                p_ccb->local_cid, p_ccb->fcrb.next_seq_expected, tx_seq, p_ccb->fcrb.p_rx_sdu);
1340
1341        /* Lost one or more packets, so flush the SAR queue */
1342        if (p_ccb->fcrb.p_rx_sdu != NULL)
1343        {
1344            GKI_freebuf (p_ccb->fcrb.p_rx_sdu);
1345            p_ccb->fcrb.p_rx_sdu = NULL;
1346        }
1347    }
1348
1349    p_ccb->fcrb.next_seq_expected = (tx_seq + 1) & L2CAP_FCR_SEQ_MODULO;
1350
1351    if (!do_sar_reassembly (p_ccb, p_buf, ctrl_word))
1352    {
1353        /* Some sort of SAR error, so flush the SAR queue */
1354        if (p_ccb->fcrb.p_rx_sdu != NULL)
1355        {
1356            GKI_freebuf (p_ccb->fcrb.p_rx_sdu);
1357            p_ccb->fcrb.p_rx_sdu = NULL;
1358        }
1359    }
1360}
1361
1362
1363/*******************************************************************************
1364**
1365** Function         do_sar_reassembly
1366**
1367** Description      Process SAR bits and re-assemble frame
1368**
1369** Returns          TRUE if all OK, else FALSE
1370**
1371*******************************************************************************/
1372static BOOLEAN do_sar_reassembly (tL2C_CCB *p_ccb, BT_HDR *p_buf, UINT16 ctrl_word)
1373{
1374    assert(p_ccb != NULL);
1375    assert(p_buf != NULL);
1376
1377    tL2C_FCRB   *p_fcrb = &p_ccb->fcrb;
1378    UINT16      sar_type = ctrl_word & L2CAP_FCR_SEG_BITS;
1379    BOOLEAN     packet_ok = TRUE;
1380    UINT8       *p;
1381
1382    /* Check if the SAR state is correct */
1383    if ((sar_type == L2CAP_FCR_UNSEG_SDU) || (sar_type == L2CAP_FCR_START_SDU))
1384    {
1385        if (p_fcrb->p_rx_sdu != NULL)
1386        {
1387            L2CAP_TRACE_WARNING ("SAR - got unexpected unsegmented or start SDU  Expected len: %u  Got so far: %u",
1388                                  p_fcrb->rx_sdu_len, p_fcrb->p_rx_sdu->len);
1389
1390            packet_ok = FALSE;
1391        }
1392        /* Check the length of the packet */
1393        if ( (sar_type == L2CAP_FCR_START_SDU) && (p_buf->len < L2CAP_SDU_LEN_OVERHEAD) )
1394        {
1395            L2CAP_TRACE_WARNING ("SAR start packet too short: %u", p_buf->len);
1396            packet_ok = FALSE;
1397        }
1398    }
1399    else
1400    {
1401        if (p_fcrb->p_rx_sdu == NULL)
1402        {
1403            L2CAP_TRACE_WARNING ("SAR - got unexpected cont or end SDU");
1404            packet_ok = FALSE;
1405        }
1406    }
1407
1408    if ( (packet_ok) && (sar_type != L2CAP_FCR_UNSEG_SDU) )
1409    {
1410        p = ((UINT8 *)(p_buf + 1)) + p_buf->offset;
1411
1412        /* For start SDU packet, extract the SDU length */
1413        if (sar_type == L2CAP_FCR_START_SDU)
1414        {
1415            /* Get the SDU length */
1416            STREAM_TO_UINT16 (p_fcrb->rx_sdu_len, p);
1417            p_buf->offset += 2;
1418            p_buf->len    -= 2;
1419
1420            if (p_fcrb->rx_sdu_len > p_ccb->max_rx_mtu)
1421            {
1422                L2CAP_TRACE_WARNING ("SAR - SDU len: %u  larger than MTU: %u", p_fcrb->rx_sdu_len, p_fcrb->rx_sdu_len);
1423                packet_ok = FALSE;
1424            }
1425            else if ((p_fcrb->p_rx_sdu = (BT_HDR *)GKI_getpoolbuf (p_ccb->ertm_info.user_rx_pool_id)) == NULL)
1426            {
1427                L2CAP_TRACE_ERROR ("SAR - no buffer for SDU start user_rx_pool_id:%d", p_ccb->ertm_info.user_rx_pool_id);
1428                packet_ok = FALSE;
1429            }
1430            else
1431            {
1432                p_fcrb->p_rx_sdu->offset = 4; /* this is the minimal offset required by OBX to process incoming packets */
1433                p_fcrb->p_rx_sdu->len    = 0;
1434            }
1435        }
1436
1437        if (packet_ok)
1438        {
1439            if ((p_fcrb->p_rx_sdu->len + p_buf->len) > p_fcrb->rx_sdu_len)
1440            {
1441                L2CAP_TRACE_ERROR ("SAR - SDU len exceeded  Type: %u   Lengths: %u %u %u",
1442                                    sar_type, p_fcrb->p_rx_sdu->len, p_buf->len, p_fcrb->rx_sdu_len);
1443                packet_ok = FALSE;
1444            }
1445            else if ( (sar_type == L2CAP_FCR_END_SDU) && ((p_fcrb->p_rx_sdu->len + p_buf->len) != p_fcrb->rx_sdu_len) )
1446            {
1447                L2CAP_TRACE_WARNING ("SAR - SDU end rcvd but SDU incomplete: %u %u %u",
1448                                      p_fcrb->p_rx_sdu->len, p_buf->len, p_fcrb->rx_sdu_len);
1449                packet_ok = FALSE;
1450            }
1451            else
1452            {
1453                memcpy (((UINT8 *) (p_fcrb->p_rx_sdu + 1)) + p_fcrb->p_rx_sdu->offset + p_fcrb->p_rx_sdu->len, p, p_buf->len);
1454
1455                p_fcrb->p_rx_sdu->len += p_buf->len;
1456
1457                GKI_freebuf (p_buf);
1458                p_buf = NULL;
1459
1460                if (sar_type == L2CAP_FCR_END_SDU)
1461                {
1462                    p_buf            = p_fcrb->p_rx_sdu;
1463                    p_fcrb->p_rx_sdu = NULL;
1464                }
1465            }
1466        }
1467    }
1468
1469    if (packet_ok == FALSE)
1470    {
1471        GKI_freebuf (p_buf);
1472    }
1473    else if (p_buf != NULL)
1474    {
1475#if (L2CAP_NUM_FIXED_CHNLS > 0)
1476        if (p_ccb->local_cid < L2CAP_BASE_APPL_CID &&
1477            (p_ccb->local_cid >= L2CAP_FIRST_FIXED_CHNL && p_ccb->local_cid <= L2CAP_LAST_FIXED_CHNL))
1478        {
1479            if (l2cb.fixed_reg[p_ccb->local_cid - L2CAP_FIRST_FIXED_CHNL].pL2CA_FixedData_Cb)
1480                (*l2cb.fixed_reg[p_ccb->local_cid - L2CAP_FIRST_FIXED_CHNL].pL2CA_FixedData_Cb)(p_ccb->p_lcb->remote_bd_addr, p_buf);
1481        }
1482        else
1483#endif
1484            l2c_csm_execute (p_ccb, L2CEVT_L2CAP_DATA, p_buf);
1485    }
1486
1487    return (packet_ok);
1488}
1489
1490
1491/*******************************************************************************
1492**
1493** Function         retransmit_i_frames
1494**
1495** Description      This function retransmits i-frames awaiting acks.
1496**
1497** Returns          BOOLEAN - TRUE if retransmitted
1498**
1499*******************************************************************************/
1500static BOOLEAN retransmit_i_frames (tL2C_CCB *p_ccb, UINT8 tx_seq)
1501{
1502    assert(p_ccb != NULL);
1503
1504    BT_HDR      *p_buf, *p_buf2;
1505    UINT8       *p;
1506    UINT8       buf_seq;
1507    UINT16      ctrl_word;
1508
1509    if ( (GKI_getfirst(&p_ccb->fcrb.waiting_for_ack_q))
1510     &&  (p_ccb->peer_cfg.fcr.max_transmit != 0)
1511     &&  (p_ccb->fcrb.num_tries >= p_ccb->peer_cfg.fcr.max_transmit) )
1512    {
1513        L2CAP_TRACE_EVENT ("Max Tries Exceeded:  (last_acq: %d  CID: 0x%04x  num_tries: %u (max: %u) ack_q_count: %u",
1514                p_ccb->fcrb.last_rx_ack, p_ccb->local_cid, p_ccb->fcrb.num_tries, p_ccb->peer_cfg.fcr.max_transmit,
1515                GKI_queue_length(&p_ccb->fcrb.waiting_for_ack_q));
1516
1517        l2cu_disconnect_chnl (p_ccb);
1518        return (FALSE);
1519    }
1520
1521    /* tx_seq indicates whether to retransmit a specific sequence or all (if == L2C_FCR_RETX_ALL_PKTS) */
1522    if (tx_seq != L2C_FCR_RETX_ALL_PKTS)
1523    {
1524        /* If sending only one, the sequence number tells us which one. Look for it.
1525        */
1526        for (p_buf = (BT_HDR *)GKI_getfirst(&p_ccb->fcrb.waiting_for_ack_q); p_buf; p_buf = (BT_HDR *)GKI_getnext (p_buf))
1527        {
1528            /* Get the old control word */
1529            p = ((UINT8 *) (p_buf+1)) + p_buf->offset + L2CAP_PKT_OVERHEAD;
1530
1531            STREAM_TO_UINT16 (ctrl_word, p);
1532
1533            buf_seq = (ctrl_word & L2CAP_FCR_TX_SEQ_BITS) >> L2CAP_FCR_TX_SEQ_BITS_SHIFT;
1534
1535            L2CAP_TRACE_DEBUG ("retransmit_i_frames()   cur seq: %u  looking for: %u", buf_seq, tx_seq);
1536
1537            if (tx_seq == buf_seq)
1538                break;
1539        }
1540
1541        if (!p_buf)
1542        {
1543            L2CAP_TRACE_ERROR ("retransmit_i_frames() UNKNOWN seq: %u  q_count: %u", tx_seq, GKI_queue_length(&p_ccb->fcrb.waiting_for_ack_q));
1544            return (TRUE);
1545        }
1546    }
1547    else
1548    {
1549        // Iterate though list and flush the amount requested from
1550        // the transmit data queue that satisfy the layer and event conditions.
1551        for (const list_node_t *node = list_begin(p_ccb->p_lcb->link_xmit_data_q);
1552            node != list_end(p_ccb->p_lcb->link_xmit_data_q);) {
1553          BT_HDR *p_buf = (BT_HDR *)list_node(node);
1554          node = list_next(node);
1555
1556            /* Do not flush other CIDs or partial segments */
1557          if ((p_buf->layer_specific == 0) && (p_buf->event == p_ccb->local_cid)) {
1558            list_remove(p_ccb->p_lcb->link_xmit_data_q, p_buf);
1559            GKI_freebuf(p_buf);
1560          }
1561        }
1562
1563        /* Also flush our retransmission queue */
1564        while (!GKI_queue_is_empty(&p_ccb->fcrb.retrans_q))
1565            GKI_freebuf (GKI_dequeue (&p_ccb->fcrb.retrans_q));
1566
1567        p_buf = (BT_HDR *)GKI_getfirst(&p_ccb->fcrb.waiting_for_ack_q);
1568    }
1569
1570    while (p_buf != NULL)
1571    {
1572        p_buf2 = l2c_fcr_clone_buf (p_buf, p_buf->offset, p_buf->len, p_ccb->ertm_info.fcr_tx_pool_id);
1573
1574        if (p_buf2)
1575        {
1576            p_buf2->layer_specific = p_buf->layer_specific;
1577
1578            GKI_enqueue (&p_ccb->fcrb.retrans_q, p_buf2);
1579        }
1580
1581        if ( (tx_seq != L2C_FCR_RETX_ALL_PKTS) || (p_buf2 == NULL) )
1582            break;
1583        else
1584            p_buf = (BT_HDR *)GKI_getnext (p_buf);
1585    }
1586
1587    l2c_link_check_send_pkts (p_ccb->p_lcb, NULL, NULL);
1588
1589    if (GKI_queue_length(&p_ccb->fcrb.waiting_for_ack_q))
1590    {
1591        p_ccb->fcrb.num_tries++;
1592        l2c_fcr_start_timer (p_ccb);
1593    }
1594
1595    return (TRUE);
1596}
1597
1598
1599/*******************************************************************************
1600**
1601** Function         l2c_fcr_get_next_xmit_sdu_seg
1602**
1603** Description      Get the next SDU segment to transmit.
1604**
1605** Returns          pointer to buffer with segment or NULL
1606**
1607*******************************************************************************/
1608BT_HDR *l2c_fcr_get_next_xmit_sdu_seg (tL2C_CCB *p_ccb, UINT16 max_packet_length)
1609{
1610    assert(p_ccb != NULL);
1611
1612    BOOLEAN     first_seg    = FALSE,       /* The segment is the first part of data  */
1613                mid_seg      = FALSE,       /* The segment is the middle part of data */
1614                last_seg     = FALSE;       /* The segment is the last part of data   */
1615    UINT16      sdu_len = 0;
1616    BT_HDR      *p_buf, *p_xmit;
1617    UINT8       *p;
1618    UINT16      max_pdu = p_ccb->tx_mps /* Needed? - L2CAP_MAX_HEADER_FCS*/;
1619
1620    /* If there is anything in the retransmit queue, that goes first
1621    */
1622    if (GKI_getfirst(&p_ccb->fcrb.retrans_q))
1623    {
1624        p_buf = (BT_HDR *)GKI_dequeue (&p_ccb->fcrb.retrans_q);
1625
1626        /* Update Rx Seq and FCS if we acked some packets while this one was queued */
1627        prepare_I_frame (p_ccb, p_buf, TRUE);
1628
1629        p_buf->event = p_ccb->local_cid;
1630
1631#if (L2CAP_ERTM_STATS == TRUE)
1632        p_ccb->fcrb.pkts_retransmitted++;
1633        p_ccb->fcrb.ertm_pkt_counts[0]++;
1634        p_ccb->fcrb.ertm_byte_counts[0] += (p_buf->len - 8);
1635#endif
1636        return (p_buf);
1637    }
1638
1639    /* For BD/EDR controller, max_packet_length is set to 0             */
1640    /* For AMP controller, max_packet_length is set by available blocks */
1641    if ( (max_packet_length > L2CAP_MAX_HEADER_FCS)
1642      && (max_pdu + L2CAP_MAX_HEADER_FCS > max_packet_length) )
1643    {
1644        max_pdu = max_packet_length - L2CAP_MAX_HEADER_FCS;
1645    }
1646
1647    p_buf = (BT_HDR *)GKI_getfirst(&p_ccb->xmit_hold_q);
1648
1649    /* If there is more data than the MPS, it requires segmentation */
1650    if (p_buf->len > max_pdu)
1651    {
1652        /* We are using the "event" field to tell is if we already started segmentation */
1653        if (p_buf->event == 0)
1654        {
1655            first_seg = TRUE;
1656            sdu_len   = p_buf->len;
1657        }
1658        else
1659            mid_seg = TRUE;
1660
1661        /* Get a new buffer and copy the data that can be sent in a PDU */
1662        p_xmit = l2c_fcr_clone_buf (p_buf, L2CAP_MIN_OFFSET + L2CAP_SDU_LEN_OFFSET,
1663                                    max_pdu, p_ccb->ertm_info.fcr_tx_pool_id);
1664
1665        if (p_xmit != NULL)
1666        {
1667            p_buf->event  = p_ccb->local_cid;
1668            p_xmit->event = p_ccb->local_cid;
1669
1670            p_buf->len    -= max_pdu;
1671            p_buf->offset += max_pdu;
1672
1673            /* copy PBF setting */
1674            p_xmit->layer_specific = p_buf->layer_specific;
1675        }
1676        else /* Should never happen if the application has configured buffers correctly */
1677        {
1678            L2CAP_TRACE_ERROR ("L2CAP - cannot get buffer, for segmentation, pool: %u", p_ccb->ertm_info.fcr_tx_pool_id);
1679            return (NULL);
1680        }
1681    }
1682    else    /* Use the original buffer if no segmentation, or the last segment */
1683    {
1684        p_xmit = (BT_HDR *)GKI_dequeue (&p_ccb->xmit_hold_q);
1685
1686        if (p_xmit->event != 0)
1687            last_seg = TRUE;
1688
1689        p_xmit->event = p_ccb->local_cid;
1690    }
1691
1692    /* Step back to add the L2CAP headers */
1693    p_xmit->offset -= (L2CAP_PKT_OVERHEAD + L2CAP_FCR_OVERHEAD);
1694    p_xmit->len    += L2CAP_PKT_OVERHEAD + L2CAP_FCR_OVERHEAD;
1695
1696    if (first_seg)
1697    {
1698        p_xmit->offset -= L2CAP_SDU_LEN_OVERHEAD;
1699        p_xmit->len    += L2CAP_SDU_LEN_OVERHEAD;
1700    }
1701
1702    /* Set the pointer to the beginning of the data */
1703    p = (UINT8 *)(p_xmit + 1) + p_xmit->offset;
1704
1705    /* Now the L2CAP header */
1706
1707    /* Note: if FCS has to be included then the length is recalculated later */
1708    UINT16_TO_STREAM (p, p_xmit->len - L2CAP_PKT_OVERHEAD);
1709
1710    UINT16_TO_STREAM (p, p_ccb->remote_cid);
1711
1712    if (first_seg)
1713    {
1714        /* Skip control word and add SDU length */
1715        p += 2;
1716        UINT16_TO_STREAM (p, sdu_len);
1717
1718        /* We will store the SAR type in layer-specific */
1719        /* layer_specific is shared with flushable flag(bits 0-1), don't clear it */
1720        p_xmit->layer_specific |= L2CAP_FCR_START_SDU;
1721
1722        first_seg = FALSE;
1723    }
1724    else if (mid_seg)
1725        p_xmit->layer_specific |= L2CAP_FCR_CONT_SDU;
1726    else if (last_seg)
1727        p_xmit->layer_specific |= L2CAP_FCR_END_SDU;
1728    else
1729        p_xmit->layer_specific |= L2CAP_FCR_UNSEG_SDU;
1730
1731    prepare_I_frame (p_ccb, p_xmit, FALSE);
1732
1733    if (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_ERTM_MODE)
1734    {
1735        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);
1736
1737        if (!p_wack)
1738        {
1739            L2CAP_TRACE_ERROR ("L2CAP - no buffer for xmit cloning, CID: 0x%04x  Pool: %u  Count: %u",
1740                                p_ccb->local_cid, p_ccb->ertm_info.fcr_tx_pool_id,  GKI_poolfreecount(p_ccb->ertm_info.fcr_tx_pool_id));
1741
1742            /* We will not save the FCS in case we reconfigure and change options */
1743            if (p_ccb->bypass_fcs != L2CAP_BYPASS_FCS)
1744                p_xmit->len -= L2CAP_FCS_LEN;
1745
1746            /* Pretend we sent it and it got lost */
1747            GKI_enqueue (&p_ccb->fcrb.waiting_for_ack_q, p_xmit);
1748            return (NULL);
1749        }
1750        else
1751        {
1752#if (L2CAP_ERTM_STATS == TRUE)
1753            /* set timestamp at the end of tx I-frame to get acking delay */
1754            p = ((UINT8 *) (p_wack+1)) + p_wack->offset + p_wack->len;
1755            UINT32_TO_STREAM (p, GKI_get_os_tick_count());
1756#endif
1757            /* We will not save the FCS in case we reconfigure and change options */
1758            if (p_ccb->bypass_fcs != L2CAP_BYPASS_FCS)
1759                p_wack->len -= L2CAP_FCS_LEN;
1760
1761            p_wack->layer_specific = p_xmit->layer_specific;
1762            GKI_enqueue (&p_ccb->fcrb.waiting_for_ack_q, p_wack);
1763        }
1764
1765#if (L2CAP_ERTM_STATS == TRUE)
1766        p_ccb->fcrb.ertm_pkt_counts[0]++;
1767        p_ccb->fcrb.ertm_byte_counts[0] += (p_xmit->len - 8);
1768#endif
1769
1770    }
1771
1772    return (p_xmit);
1773}
1774
1775
1776/*******************************************************************************
1777** Configuration negotiation functions
1778**
1779** The following functions are used in negotiating channel modes during
1780** configuration
1781********************************************************************************/
1782
1783/*******************************************************************************
1784**
1785** Function         l2c_fcr_chk_chan_modes
1786**
1787** Description      Validates and adjusts if necessary, the FCR options
1788**                  based on remote EXT features.
1789**
1790**                  Note: This assumes peer EXT Features have been received.
1791**                      Basic mode is used if FCR Options have not been received
1792**
1793** Returns          UINT8 - nonzero if can continue, '0' if no compatible channels
1794**
1795*******************************************************************************/
1796UINT8 l2c_fcr_chk_chan_modes (tL2C_CCB *p_ccb)
1797{
1798    assert(p_ccb != NULL);
1799
1800    /* Remove nonbasic options that the peer does not support */
1801    if (!(p_ccb->p_lcb->peer_ext_fea & L2CAP_EXTFEA_ENH_RETRANS))
1802        p_ccb->ertm_info.allowed_modes &= ~L2CAP_FCR_CHAN_OPT_ERTM;
1803
1804    if (!(p_ccb->p_lcb->peer_ext_fea & L2CAP_EXTFEA_STREAM_MODE))
1805        p_ccb->ertm_info.allowed_modes &= ~L2CAP_FCR_CHAN_OPT_STREAM;
1806
1807    /* At least one type needs to be set (Basic, ERTM, STM) to continue */
1808    if (!p_ccb->ertm_info.allowed_modes)
1809    {
1810        L2CAP_TRACE_WARNING ("L2CAP - Peer does not support our desired channel types");
1811    }
1812
1813    return (p_ccb->ertm_info.allowed_modes);
1814}
1815
1816/*******************************************************************************
1817**
1818** Function         l2c_fcr_adj_our_req_options
1819**
1820** Description      Validates and sets up the FCR options passed in from
1821**                  L2CA_ConfigReq based on remote device's features.
1822**
1823** Returns          TRUE if no errors, Otherwise FALSE
1824**
1825*******************************************************************************/
1826BOOLEAN l2c_fcr_adj_our_req_options (tL2C_CCB *p_ccb, tL2CAP_CFG_INFO *p_cfg)
1827{
1828    assert(p_ccb != NULL);
1829    assert(p_cfg != NULL);
1830
1831    tL2CAP_FCR_OPTS *p_fcr = &p_cfg->fcr;
1832
1833    if (p_fcr->mode != p_ccb->ertm_info.preferred_mode)
1834    {
1835        L2CAP_TRACE_WARNING ("l2c_fcr_adj_our_req_options - preferred_mode (%d), does not match mode (%d)",
1836                            p_ccb->ertm_info.preferred_mode, p_fcr->mode);
1837
1838        /* The preferred mode is passed in through tL2CAP_ERTM_INFO, so override this one */
1839        p_fcr->mode = p_ccb->ertm_info.preferred_mode;
1840    }
1841
1842    /* If upper layer did not request eRTM mode, BASIC must be used */
1843    if (p_ccb->ertm_info.allowed_modes == L2CAP_FCR_CHAN_OPT_BASIC)
1844    {
1845        if (p_cfg->fcr_present && p_fcr->mode != L2CAP_FCR_BASIC_MODE)
1846        {
1847            L2CAP_TRACE_WARNING ("l2c_fcr_adj_our_req_options (mode %d): ERROR: No FCR options set using BASIC mode", p_fcr->mode);
1848        }
1849        p_fcr->mode = L2CAP_FCR_BASIC_MODE;
1850    }
1851
1852    /* Process the FCR options if initial channel bring-up (not a reconfig request)
1853    ** Determine initial channel mode to try based on our options and remote's features
1854    */
1855    if (p_cfg->fcr_present && !(p_ccb->config_done & RECONFIG_FLAG))
1856    {
1857        /* We need to have at least one mode type common with the peer */
1858        if (!l2c_fcr_chk_chan_modes(p_ccb))
1859        {
1860            /* Two channels have incompatible supported types */
1861            l2cu_disconnect_chnl (p_ccb);
1862            return (FALSE);
1863        }
1864
1865        /* Basic is the only common channel mode between the two devices */
1866        else if (p_ccb->ertm_info.allowed_modes == L2CAP_FCR_CHAN_OPT_BASIC)
1867        {
1868            /* We only want to try Basic, so bypass sending the FCR options entirely */
1869            p_cfg->fcr_present = FALSE;
1870            p_cfg->fcs_present = FALSE;             /* Illegal to use FCS option in basic mode */
1871            p_cfg->ext_flow_spec_present = FALSE;   /* Illegal to use extended flow spec in basic mode */
1872        }
1873
1874        /* We have at least one non-basic mode available
1875         * Override mode from available mode options based on preference, if needed
1876         */
1877        else
1878        {
1879            /* If peer does not support STREAMING, try ERTM */
1880            if (p_fcr->mode == L2CAP_FCR_STREAM_MODE && !(p_ccb->ertm_info.allowed_modes & L2CAP_FCR_CHAN_OPT_STREAM))
1881            {
1882                L2CAP_TRACE_DEBUG ("L2C CFG: mode is STREAM, but peer does not support; Try ERTM");
1883                p_fcr->mode = L2CAP_FCR_ERTM_MODE;
1884            }
1885
1886            /* If peer does not support ERTM, try BASIC (will support this if made it here in the code) */
1887            if (p_fcr->mode == L2CAP_FCR_ERTM_MODE && !(p_ccb->ertm_info.allowed_modes & L2CAP_FCR_CHAN_OPT_ERTM))
1888            {
1889                L2CAP_TRACE_DEBUG ("L2C CFG: mode is ERTM, but peer does not support; Try BASIC");
1890                p_fcr->mode = L2CAP_FCR_BASIC_MODE;
1891            }
1892        }
1893
1894        if (p_fcr->mode != L2CAP_FCR_BASIC_MODE)
1895        {
1896            /* MTU must be smaller than buffer size */
1897            if ( (p_cfg->mtu_present) && (p_cfg->mtu > p_ccb->max_rx_mtu) )
1898            {
1899                L2CAP_TRACE_WARNING ("L2CAP - MTU: %u  larger than buf size: %u", p_cfg->mtu, p_ccb->max_rx_mtu);
1900                return (FALSE);
1901            }
1902
1903            /* application want to use the default MPS */
1904            if (p_fcr->mps == L2CAP_DEFAULT_ERM_MPS)
1905            {
1906                p_fcr->mps = L2CAP_MPS_OVER_BR_EDR;
1907            }
1908            /* MPS must be less than MTU */
1909            else if (p_fcr->mps > p_ccb->max_rx_mtu)
1910            {
1911                L2CAP_TRACE_WARNING ("L2CAP - MPS  %u  invalid  MTU: %u", p_fcr->mps, p_ccb->max_rx_mtu);
1912                return (FALSE);
1913            }
1914
1915            /* We always initially read into the HCI buffer pool, so make sure it fits */
1916            if (p_fcr->mps > (L2CAP_MTU_SIZE - L2CAP_MAX_HEADER_FCS))
1917                p_fcr->mps = L2CAP_MTU_SIZE - L2CAP_MAX_HEADER_FCS;
1918        }
1919        else
1920        {
1921            p_cfg->fcs_present = FALSE;             /* Illegal to use FCS option in basic mode */
1922            p_cfg->ext_flow_spec_present = FALSE;   /* Illegal to use extended flow spec in basic mode */
1923        }
1924
1925        p_ccb->our_cfg.fcr = *p_fcr;
1926    }
1927    else    /* Not sure how to send a reconfiguration(??) should fcr be included? */
1928    {
1929        p_ccb->our_cfg.fcr_present = FALSE;
1930    }
1931
1932    return (TRUE);
1933}
1934
1935
1936/*******************************************************************************
1937**
1938** Function         l2c_fcr_adj_monitor_retran_timeout
1939**
1940** Description      Overrides monitor/retrans timer value based on controller
1941**
1942** Returns          None
1943**
1944*******************************************************************************/
1945void l2c_fcr_adj_monitor_retran_timeout (tL2C_CCB *p_ccb)
1946{
1947    assert(p_ccb != NULL);
1948
1949    /* adjust our monitor/retran timeout */
1950    if (p_ccb->out_cfg_fcr_present)
1951    {
1952        /*
1953        ** if we requestd ERTM or accepted ERTM
1954        ** We may accept ERTM even if we didn't request ERTM, in case of requesting STREAM
1955        */
1956        if ((p_ccb->our_cfg.fcr.mode == L2CAP_FCR_ERTM_MODE)
1957          ||(p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_ERTM_MODE))
1958        {
1959            /* upper layer setting is ignored */
1960            p_ccb->our_cfg.fcr.mon_tout    = L2CAP_MIN_MONITOR_TOUT;
1961            p_ccb->our_cfg.fcr.rtrans_tout = L2CAP_MIN_RETRANS_TOUT;
1962        }
1963        else
1964        {
1965            p_ccb->our_cfg.fcr.mon_tout    = 0;
1966            p_ccb->our_cfg.fcr.rtrans_tout = 0;
1967        }
1968
1969        L2CAP_TRACE_DEBUG ("l2c_fcr_adj_monitor_retran_timeout: mon_tout:%d, rtrans_tout:%d",
1970                             p_ccb->our_cfg.fcr.mon_tout, p_ccb->our_cfg.fcr.rtrans_tout);
1971    }
1972}
1973/*******************************************************************************
1974**
1975** Function         l2c_fcr_adj_our_rsp_options
1976**
1977** Description      Overrides any neccesary FCR options passed in from
1978**                  L2CA_ConfigRsp based on our FCR options.
1979**                  Only makes adjustments if channel is in ERTM mode.
1980**
1981** Returns          None
1982**
1983*******************************************************************************/
1984void l2c_fcr_adj_our_rsp_options (tL2C_CCB *p_ccb, tL2CAP_CFG_INFO *p_cfg)
1985{
1986    assert(p_ccb != NULL);
1987    assert(p_cfg != NULL);
1988
1989    /* adjust our monitor/retran timeout */
1990    l2c_fcr_adj_monitor_retran_timeout(p_ccb);
1991
1992    p_cfg->fcr_present = p_ccb->out_cfg_fcr_present;
1993
1994    if (p_cfg->fcr_present)
1995    {
1996// btla-specific ++
1997        /* Temporary - until a better algorithm is implemented */
1998        /* 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. */
1999        /* Note: peer is not guaranteed to obey our adjustment */
2000        if (p_ccb->peer_cfg.fcr.tx_win_sz > p_ccb->our_cfg.fcr.tx_win_sz)
2001        {
2002            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);
2003            p_ccb->peer_cfg.fcr.tx_win_sz = p_ccb->our_cfg.fcr.tx_win_sz;
2004        }
2005// btla-specific --
2006
2007        p_cfg->fcr.mode         = p_ccb->peer_cfg.fcr.mode;
2008        p_cfg->fcr.tx_win_sz    = p_ccb->peer_cfg.fcr.tx_win_sz;
2009        p_cfg->fcr.max_transmit = p_ccb->peer_cfg.fcr.max_transmit;
2010        p_cfg->fcr.mps          = p_ccb->peer_cfg.fcr.mps;
2011        p_cfg->fcr.rtrans_tout  = p_ccb->our_cfg.fcr.rtrans_tout;
2012        p_cfg->fcr.mon_tout     = p_ccb->our_cfg.fcr.mon_tout;
2013    }
2014}
2015
2016/*******************************************************************************
2017**
2018** Function         l2c_fcr_renegotiate_chan
2019**
2020** Description      Called upon unsuccessful peer response to config request.
2021**                  If the error is because of the channel mode, it will try
2022**                  to resend using another supported optional channel.
2023**
2024** Returns          TRUE if resent configuration, False if channel matches or
2025**                  cannot match.
2026**
2027*******************************************************************************/
2028BOOLEAN l2c_fcr_renegotiate_chan(tL2C_CCB *p_ccb, tL2CAP_CFG_INFO *p_cfg)
2029{
2030    assert(p_ccb != NULL);
2031    assert(p_cfg != NULL);
2032
2033    UINT8   peer_mode = p_ccb->our_cfg.fcr.mode;
2034    BOOLEAN can_renegotiate;
2035
2036    /* Skip if this is a reconfiguration from OPEN STATE or if FCR is not returned */
2037    if (!p_cfg->fcr_present || (p_ccb->config_done & RECONFIG_FLAG))
2038        return (FALSE);
2039
2040    /* Only retry if there are more channel options to try */
2041    if (p_cfg->result == L2CAP_CFG_UNACCEPTABLE_PARAMS)
2042    {
2043        peer_mode = (p_cfg->fcr_present) ? p_cfg->fcr.mode : L2CAP_FCR_BASIC_MODE;
2044
2045        if (p_ccb->our_cfg.fcr.mode != peer_mode)
2046        {
2047
2048            if ((--p_ccb->fcr_cfg_tries) == 0)
2049            {
2050                p_cfg->result = L2CAP_CFG_FAILED_NO_REASON;
2051                L2CAP_TRACE_WARNING ("l2c_fcr_renegotiate_chan (Max retries exceeded)");
2052            }
2053
2054            can_renegotiate = FALSE;
2055
2056            /* Try another supported mode if available based on our last attempted channel */
2057            switch (p_ccb->our_cfg.fcr.mode)
2058            {
2059                /* Our Streaming mode request was unnacceptable; try ERTM or Basic */
2060            case L2CAP_FCR_STREAM_MODE:
2061                /* Peer wants ERTM and we support it */
2062                if ( (peer_mode == L2CAP_FCR_ERTM_MODE) && (p_ccb->ertm_info.allowed_modes & L2CAP_FCR_CHAN_OPT_ERTM) )
2063                {
2064                    L2CAP_TRACE_DEBUG ("l2c_fcr_renegotiate_chan(Trying ERTM)");
2065                    p_ccb->our_cfg.fcr.mode = L2CAP_FCR_ERTM_MODE;
2066                    can_renegotiate = TRUE;
2067                }
2068                else    /* Falls through */
2069
2070            case L2CAP_FCR_ERTM_MODE:
2071                {
2072                    /* We can try basic for any other peer mode if we support it */
2073                    if (p_ccb->ertm_info.allowed_modes & L2CAP_FCR_CHAN_OPT_BASIC)
2074                    {
2075                        L2CAP_TRACE_DEBUG ("l2c_fcr_renegotiate_chan(Trying Basic)");
2076                        can_renegotiate = TRUE;
2077                        p_ccb->our_cfg.fcr.mode = L2CAP_FCR_BASIC_MODE;
2078                    }
2079                }
2080                break;
2081
2082            default:
2083                /* All other scenarios cannot be renegotiated */
2084                break;
2085            }
2086
2087            if (can_renegotiate)
2088            {
2089                p_ccb->our_cfg.fcr_present = TRUE;
2090
2091                if (p_ccb->our_cfg.fcr.mode == L2CAP_FCR_BASIC_MODE)
2092                {
2093                    p_ccb->our_cfg.fcs_present = FALSE;
2094                    p_ccb->our_cfg.ext_flow_spec_present = FALSE;
2095
2096                    /* Basic Mode uses ACL Data Pool, make sure the MTU fits */
2097                    if ( (p_cfg->mtu_present) && (p_cfg->mtu > L2CAP_MTU_SIZE) )
2098                    {
2099                        L2CAP_TRACE_WARNING ("L2CAP - adjust MTU: %u too large", p_cfg->mtu);
2100                        p_cfg->mtu = L2CAP_MTU_SIZE;
2101                    }
2102                }
2103
2104                l2cu_process_our_cfg_req (p_ccb, &p_ccb->our_cfg);
2105                l2cu_send_peer_config_req (p_ccb, &p_ccb->our_cfg);
2106                btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_CFG_TIMEOUT);
2107                return (TRUE);
2108            }
2109        }
2110    }
2111
2112    /* Disconnect if the channels do not match */
2113    if (p_ccb->our_cfg.fcr.mode != peer_mode)
2114    {
2115        L2CAP_TRACE_WARNING ("L2C CFG:  Channels incompatible (local %d, peer %d)",
2116                              p_ccb->our_cfg.fcr.mode, peer_mode);
2117        l2cu_disconnect_chnl (p_ccb);
2118    }
2119
2120    return (FALSE);
2121}
2122
2123
2124/*******************************************************************************
2125**
2126** Function         l2c_fcr_process_peer_cfg_req
2127**
2128** Description      This function is called to process the FCR options passed
2129**                  in the peer's configuration request.
2130**
2131** Returns          UINT8 - L2CAP_PEER_CFG_OK, L2CAP_PEER_CFG_UNACCEPTABLE,
2132**                          or L2CAP_PEER_CFG_DISCONNECT.
2133**
2134*******************************************************************************/
2135UINT8 l2c_fcr_process_peer_cfg_req(tL2C_CCB *p_ccb, tL2CAP_CFG_INFO *p_cfg)
2136{
2137    assert(p_ccb != NULL);
2138    assert(p_cfg != NULL);
2139
2140    UINT16 max_retrans_size;
2141    UINT8  fcr_ok = L2CAP_PEER_CFG_OK;
2142
2143    p_ccb->p_lcb->w4_info_rsp = FALSE;      /* Handles T61x SonyEricsson Bug in Info Request */
2144
2145    L2CAP_TRACE_EVENT ("l2c_fcr_process_peer_cfg_req() CFG fcr_present:%d fcr.mode:%d CCB FCR mode:%d preferred: %u allowed:%u",
2146                        p_cfg->fcr_present, p_cfg->fcr.mode, p_ccb->our_cfg.fcr.mode, p_ccb->ertm_info.preferred_mode,
2147                        p_ccb->ertm_info.allowed_modes);
2148
2149    /* If Peer wants basic, we are done (accept it or disconnect) */
2150    if (p_cfg->fcr.mode == L2CAP_FCR_BASIC_MODE)
2151    {
2152        /* If we do not allow basic, disconnect */
2153        if ( !(p_ccb->ertm_info.allowed_modes & L2CAP_FCR_CHAN_OPT_BASIC) )
2154            fcr_ok = L2CAP_PEER_CFG_DISCONNECT;
2155    }
2156
2157    /* Need to negotiate if our modes are not the same */
2158    else if (p_cfg->fcr.mode != p_ccb->ertm_info.preferred_mode)
2159    {
2160        /* If peer wants a mode that we don't support then retry our mode (ex. rtx/flc), OR
2161        ** If we want ERTM and they wanted streaming retry our mode.
2162        ** Note: If we have already determined they support our mode previously
2163        **       from their EXF mask.
2164        */
2165        if ( (((1 << p_cfg->fcr.mode) & L2CAP_FCR_CHAN_OPT_ALL_MASK) == 0)
2166            || (p_ccb->ertm_info.preferred_mode == L2CAP_FCR_ERTM_MODE) )
2167        {
2168            p_cfg->fcr.mode = p_ccb->our_cfg.fcr.mode;
2169            p_cfg->fcr.tx_win_sz = p_ccb->our_cfg.fcr.tx_win_sz;
2170            p_cfg->fcr.max_transmit = p_ccb->our_cfg.fcr.max_transmit;
2171            fcr_ok = L2CAP_PEER_CFG_UNACCEPTABLE;
2172        }
2173
2174        /* If we wanted basic, then try to renegotiate it */
2175        else if (p_ccb->ertm_info.preferred_mode == L2CAP_FCR_BASIC_MODE)
2176        {
2177            p_cfg->fcr.mode = L2CAP_FCR_BASIC_MODE;
2178            p_cfg->fcr.max_transmit = p_cfg->fcr.tx_win_sz = 0;
2179            p_cfg->fcr.rtrans_tout = p_cfg->fcr.mon_tout = p_cfg->fcr.mps = 0;
2180            p_ccb->our_cfg.fcr.rtrans_tout = p_ccb->our_cfg.fcr.mon_tout = p_ccb->our_cfg.fcr.mps = 0;
2181            fcr_ok = L2CAP_PEER_CFG_UNACCEPTABLE;
2182        }
2183
2184        /* Only other valid case is if they want ERTM and we wanted STM which should be
2185           accepted if we support it; otherwise the channel should be disconnected */
2186        else if ( (p_cfg->fcr.mode != L2CAP_FCR_ERTM_MODE)
2187              || !(p_ccb->ertm_info.allowed_modes & L2CAP_FCR_CHAN_OPT_ERTM) )
2188        {
2189            fcr_ok = L2CAP_PEER_CFG_DISCONNECT;
2190        }
2191    }
2192
2193    /* Configuration for FCR channels so make any adjustments and fwd to upper layer */
2194    if (fcr_ok == L2CAP_PEER_CFG_OK)
2195    {
2196        /* by default don't need to send params in the response */
2197        p_ccb->out_cfg_fcr_present = FALSE;
2198
2199        /* Make any needed adjustments for the response to the peer */
2200        if (p_cfg->fcr_present && p_cfg->fcr.mode != L2CAP_FCR_BASIC_MODE)
2201        {
2202            /* Peer desires to bypass FCS check, and streaming or ERTM mode */
2203            if (p_cfg->fcs_present)
2204            {
2205                p_ccb->peer_cfg.fcs = p_cfg->fcs;
2206                p_ccb->peer_cfg_bits |= L2CAP_CH_CFG_MASK_FCS;
2207                if( p_cfg->fcs == L2CAP_CFG_FCS_BYPASS)
2208                    p_ccb->bypass_fcs |= L2CAP_CFG_FCS_PEER;
2209            }
2210
2211            max_retrans_size = GKI_get_pool_bufsize (p_ccb->ertm_info.fcr_tx_pool_id) - sizeof(BT_HDR)
2212                                            - L2CAP_MIN_OFFSET - L2CAP_SDU_LEN_OFFSET - L2CAP_FCS_LEN;
2213
2214            /* Ensure the MPS is not bigger than the MTU */
2215            if ( (p_cfg->fcr.mps == 0) || (p_cfg->fcr.mps > p_ccb->peer_cfg.mtu) )
2216            {
2217                p_cfg->fcr.mps = p_ccb->peer_cfg.mtu;
2218                p_ccb->out_cfg_fcr_present = TRUE;
2219            }
2220
2221            /* Ensure the MPS is not bigger than our retransmission buffer */
2222            if (p_cfg->fcr.mps > max_retrans_size)
2223            {
2224                L2CAP_TRACE_DEBUG("CFG: Overriding MPS to %d (orig %d)", max_retrans_size, p_cfg->fcr.mps);
2225
2226                p_cfg->fcr.mps = max_retrans_size;
2227                p_ccb->out_cfg_fcr_present = TRUE;
2228            }
2229
2230            if (p_cfg->fcr.mode == L2CAP_FCR_ERTM_MODE || p_cfg->fcr.mode == L2CAP_FCR_STREAM_MODE)
2231            {
2232                /* Always respond with FCR ERTM parameters */
2233                p_ccb->out_cfg_fcr_present = TRUE;
2234            }
2235        }
2236
2237        /* Everything ok, so save the peer's adjusted fcr options */
2238        p_ccb->peer_cfg.fcr = p_cfg->fcr;
2239
2240        if (p_cfg->fcr_present)
2241            p_ccb->peer_cfg_bits |= L2CAP_CH_CFG_MASK_FCR;
2242    }
2243    else if (fcr_ok == L2CAP_PEER_CFG_UNACCEPTABLE)
2244    {
2245        /* Allow peer only one retry for mode */
2246        if (p_ccb->peer_cfg_already_rejected)
2247            fcr_ok = L2CAP_PEER_CFG_DISCONNECT;
2248        else
2249            p_ccb->peer_cfg_already_rejected = TRUE;
2250    }
2251
2252    return (fcr_ok);
2253}
2254
2255#if (L2CAP_ERTM_STATS == TRUE)
2256/*******************************************************************************
2257**
2258** Function         l2c_fcr_collect_ack_delay
2259**
2260** Description      collect throughput, delay, queue size of waiting ack
2261**
2262** Parameters
2263**                  tL2C_CCB
2264**
2265** Returns          void
2266**
2267*******************************************************************************/
2268static void l2c_fcr_collect_ack_delay (tL2C_CCB *p_ccb, UINT8 num_bufs_acked)
2269{
2270    UINT32  index;
2271    BT_HDR *p_buf;
2272    UINT8  *p;
2273    UINT32  timestamp, delay;
2274    UINT8   xx;
2275    UINT8   str[120];
2276
2277    index = p_ccb->fcrb.ack_delay_avg_index;
2278
2279    /* update sum, max and min of waiting for ack queue size */
2280    p_ccb->fcrb.ack_q_count_avg[index] += p_ccb->fcrb.waiting_for_ack_q.count;
2281
2282    if ( p_ccb->fcrb.waiting_for_ack_q.count > p_ccb->fcrb.ack_q_count_max[index] )
2283        p_ccb->fcrb.ack_q_count_max[index] = p_ccb->fcrb.waiting_for_ack_q.count;
2284
2285    if ( p_ccb->fcrb.waiting_for_ack_q.count < p_ccb->fcrb.ack_q_count_min[index] )
2286        p_ccb->fcrb.ack_q_count_min[index] = p_ccb->fcrb.waiting_for_ack_q.count;
2287
2288    /* update sum, max and min of round trip delay of acking */
2289    p_buf = (BT_HDR *)(p_ccb->fcrb.waiting_for_ack_q.p_first);
2290    for (xx = 0; (xx < num_bufs_acked)&&(p_buf); xx++)
2291    {
2292        /* adding up length of acked I-frames to get throughput */
2293        p_ccb->fcrb.throughput[index] += p_buf->len - 8;
2294
2295        if ( xx == num_bufs_acked - 1 )
2296        {
2297            /* get timestamp from tx I-frame that receiver is acking */
2298            p = ((UINT8 *) (p_buf+1)) + p_buf->offset + p_buf->len;
2299            if (p_ccb->bypass_fcs != L2CAP_BYPASS_FCS)
2300            {
2301                p += L2CAP_FCS_LEN;
2302            }
2303
2304            STREAM_TO_UINT32 (timestamp, p);
2305            delay = GKI_get_os_tick_count() - timestamp;
2306
2307            p_ccb->fcrb.ack_delay_avg[index] += delay;
2308            if ( delay > p_ccb->fcrb.ack_delay_max[index] )
2309                p_ccb->fcrb.ack_delay_max[index] = delay;
2310            if ( delay < p_ccb->fcrb.ack_delay_min[index] )
2311                p_ccb->fcrb.ack_delay_min[index] = delay;
2312        }
2313
2314        p_buf = GKI_getnext(p_buf);
2315    }
2316
2317    p_ccb->fcrb.ack_delay_avg_count++;
2318
2319    /* calculate average and initialize next avg, min and max */
2320    if (p_ccb->fcrb.ack_delay_avg_count > L2CAP_ERTM_STATS_AVG_NUM_SAMPLES)
2321    {
2322        p_ccb->fcrb.ack_delay_avg_count = 0;
2323
2324        p_ccb->fcrb.ack_q_count_avg[index] /= L2CAP_ERTM_STATS_AVG_NUM_SAMPLES;
2325        p_ccb->fcrb.ack_delay_avg[index] /= L2CAP_ERTM_STATS_AVG_NUM_SAMPLES;
2326
2327        /* calculate throughput */
2328        timestamp = GKI_get_os_tick_count();
2329        if (timestamp - p_ccb->fcrb.throughput_start > 0 )
2330            p_ccb->fcrb.throughput[index] /= (timestamp - p_ccb->fcrb.throughput_start);
2331
2332        p_ccb->fcrb.throughput_start = timestamp;
2333
2334        sprintf(str, "[%02u] throughput: %5u, ack_delay avg:%3u, min:%3u, max:%3u, ack_q_count avg:%3u, min:%3u, max:%3u",
2335                index, p_ccb->fcrb.throughput[index],
2336                p_ccb->fcrb.ack_delay_avg[index], p_ccb->fcrb.ack_delay_min[index], p_ccb->fcrb.ack_delay_max[index],
2337                p_ccb->fcrb.ack_q_count_avg[index], p_ccb->fcrb.ack_q_count_min[index], p_ccb->fcrb.ack_q_count_max[index] );
2338
2339        BT_TRACE(TRACE_CTRL_GENERAL | TRACE_LAYER_GKI | TRACE_ORG_GKI , TRACE_TYPE_GENERIC, "%s", str);
2340
2341        index = (index + 1) % L2CAP_ERTM_STATS_NUM_AVG;
2342        p_ccb->fcrb.ack_delay_avg_index = index;
2343
2344        p_ccb->fcrb.ack_q_count_max[index] = 0;
2345        p_ccb->fcrb.ack_q_count_min[index] = 0xFFFFFFFF;
2346        p_ccb->fcrb.ack_q_count_avg[index] = 0;
2347
2348
2349        p_ccb->fcrb.ack_delay_max[index] = 0;
2350        p_ccb->fcrb.ack_delay_min[index] = 0xFFFFFFFF;
2351        p_ccb->fcrb.ack_delay_avg[index] = 0;
2352
2353        p_ccb->fcrb.throughput[index] = 0;
2354    }
2355}
2356#endif
2357