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      1 /******************************************************************************
      2  *
      3  *  Copyright (C) 1999-2012 Broadcom Corporation
      4  *
      5  *  Licensed under the Apache License, Version 2.0 (the "License");
      6  *  you may not use this file except in compliance with the License.
      7  *  You may obtain a copy of the License at:
      8  *
      9  *  http://www.apache.org/licenses/LICENSE-2.0
     10  *
     11  *  Unless required by applicable law or agreed to in writing, software
     12  *  distributed under the License is distributed on an "AS IS" BASIS,
     13  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14  *  See the License for the specific language governing permissions and
     15  *  limitations under the License.
     16  *
     17  ******************************************************************************/
     18 
     19 /******************************************************************************
     20  *
     21  *  This file contains the main L2CAP entry points
     22  *
     23  ******************************************************************************/
     24 
     25 #define LOG_TAG "bt_l2c_main"
     26 
     27 #include <stdio.h>
     28 #include <stdlib.h>
     29 #include <string.h>
     30 
     31 #include "bt_target.h"
     32 #include "btm_int.h"
     33 #include "btu.h"
     34 #include "device/include/controller.h"
     35 #include "bt_common.h"
     36 #include "hcimsgs.h"
     37 #include "l2c_api.h"
     38 #include "l2c_int.h"
     39 #include "l2cdefs.h"
     40 #include "osi/include/log.h"
     41 
     42 
     43 extern fixed_queue_t *btu_general_alarm_queue;
     44 
     45 /********************************************************************************/
     46 /*              L O C A L    F U N C T I O N     P R O T O T Y P E S            */
     47 /********************************************************************************/
     48 static void process_l2cap_cmd (tL2C_LCB *p_lcb, UINT8 *p, UINT16 pkt_len);
     49 
     50 /********************************************************************************/
     51 /*                 G L O B A L      L 2 C A P       D A T A                     */
     52 /********************************************************************************/
     53 #if L2C_DYNAMIC_MEMORY == FALSE
     54 tL2C_CB l2cb;
     55 #endif
     56 
     57 /*******************************************************************************
     58 **
     59 ** Function         l2c_rcv_acl_data
     60 **
     61 ** Description      This function is called from the HCI Interface when an ACL
     62 **                  data packet is received.
     63 **
     64 ** Returns          void
     65 **
     66 *******************************************************************************/
     67 void l2c_rcv_acl_data (BT_HDR *p_msg)
     68 {
     69     UINT8       *p = (UINT8 *)(p_msg + 1) + p_msg->offset;
     70     UINT16      handle, hci_len;
     71     UINT8       pkt_type;
     72     tL2C_LCB    *p_lcb;
     73     tL2C_CCB    *p_ccb = NULL;
     74     UINT16      l2cap_len, rcv_cid, psm;
     75     UINT16      credit;
     76 
     77     /* Extract the handle */
     78     STREAM_TO_UINT16 (handle, p);
     79     pkt_type = HCID_GET_EVENT (handle);
     80     handle   = HCID_GET_HANDLE (handle);
     81 
     82     /* Since the HCI Transport is putting segmented packets back together, we */
     83     /* should never get a valid packet with the type set to "continuation"    */
     84     if (pkt_type != L2CAP_PKT_CONTINUE)
     85     {
     86         /* Find the LCB based on the handle */
     87         if ((p_lcb = l2cu_find_lcb_by_handle (handle)) == NULL)
     88         {
     89             UINT8       cmd_code;
     90 
     91             /* There is a slight possibility (specifically with USB) that we get an */
     92             /* L2CAP connection request before we get the HCI connection complete.  */
     93             /* So for these types of messages, hold them for up to 2 seconds.       */
     94             STREAM_TO_UINT16 (hci_len, p);
     95             STREAM_TO_UINT16 (l2cap_len, p);
     96             STREAM_TO_UINT16 (rcv_cid, p);
     97             STREAM_TO_UINT8  (cmd_code, p);
     98 
     99             if ((p_msg->layer_specific == 0) && (rcv_cid == L2CAP_SIGNALLING_CID)
    100                     && (cmd_code == L2CAP_CMD_INFO_REQ || cmd_code == L2CAP_CMD_CONN_REQ)) {
    101                 L2CAP_TRACE_WARNING ("L2CAP - holding ACL for unknown handle:%d ls:%d"
    102                         "  cid:%d opcode:%d cur count:%d", handle, p_msg->layer_specific,
    103                         rcv_cid, cmd_code, list_length(l2cb.rcv_pending_q));
    104                 p_msg->layer_specific = 2;
    105                 list_append(l2cb.rcv_pending_q, p_msg);
    106 
    107                 if (list_length(l2cb.rcv_pending_q) == 1) {
    108                     alarm_set_on_queue(l2cb.receive_hold_timer,
    109                                        BT_1SEC_TIMEOUT_MS,
    110                                        l2c_receive_hold_timer_timeout, NULL,
    111                                        btu_general_alarm_queue);
    112                 }
    113 
    114                 return;
    115             } else {
    116                 L2CAP_TRACE_ERROR ("L2CAP - rcvd ACL for unknown handle:%d ls:%d cid:%d"
    117                         " opcode:%d cur count:%d", handle, p_msg->layer_specific, rcv_cid,
    118                         cmd_code, list_length(l2cb.rcv_pending_q));
    119             }
    120             osi_free(p_msg);
    121             return;
    122         }
    123     }
    124     else
    125     {
    126         L2CAP_TRACE_WARNING ("L2CAP - expected pkt start or complete, got: %d", pkt_type);
    127         osi_free(p_msg);
    128         return;
    129     }
    130 
    131     /* Extract the length and update the buffer header */
    132     STREAM_TO_UINT16 (hci_len, p);
    133     p_msg->offset += 4;
    134 
    135     /* Extract the length and CID */
    136     STREAM_TO_UINT16 (l2cap_len, p);
    137     STREAM_TO_UINT16 (rcv_cid, p);
    138 
    139 #if BLE_INCLUDED == TRUE
    140    /* for BLE channel, always notify connection when ACL data received on the link */
    141    if (p_lcb && p_lcb->transport == BT_TRANSPORT_LE && p_lcb->link_state != LST_DISCONNECTING)
    142       /* only process fixed channel data as channel open indication when link is not in disconnecting mode */
    143         l2cble_notify_le_connection(p_lcb->remote_bd_addr);
    144 #endif
    145 
    146     /* Find the CCB for this CID */
    147     if (rcv_cid >= L2CAP_BASE_APPL_CID)
    148     {
    149         if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, rcv_cid)) == NULL)
    150         {
    151             L2CAP_TRACE_WARNING ("L2CAP - unknown CID: 0x%04x", rcv_cid);
    152             osi_free(p_msg);
    153             return;
    154         }
    155     }
    156 
    157     if (hci_len >= L2CAP_PKT_OVERHEAD)  /* Must receive at least the L2CAP length and CID.*/
    158     {
    159         p_msg->len    = hci_len - L2CAP_PKT_OVERHEAD;
    160         p_msg->offset += L2CAP_PKT_OVERHEAD;
    161     }
    162     else
    163     {
    164         L2CAP_TRACE_WARNING ("L2CAP - got incorrect hci header" );
    165         osi_free(p_msg);
    166         return;
    167     }
    168 
    169     if (l2cap_len != p_msg->len)
    170     {
    171         L2CAP_TRACE_WARNING ("L2CAP - bad length in pkt. Exp: %d  Act: %d",
    172                               l2cap_len, p_msg->len);
    173 
    174         osi_free(p_msg);
    175         return;
    176     }
    177 
    178     /* Send the data through the channel state machine */
    179     if (rcv_cid == L2CAP_SIGNALLING_CID)
    180     {
    181         process_l2cap_cmd (p_lcb, p, l2cap_len);
    182         osi_free(p_msg);
    183     }
    184     else if (rcv_cid == L2CAP_CONNECTIONLESS_CID)
    185     {
    186         /* process_connectionless_data (p_lcb); */
    187         STREAM_TO_UINT16 (psm, p);
    188         L2CAP_TRACE_DEBUG( "GOT CONNECTIONLESS DATA PSM:%d", psm ) ;
    189 
    190 #if (L2CAP_UCD_INCLUDED == TRUE)
    191         /* if it is not broadcast, check UCD registration */
    192         if ( l2c_ucd_check_rx_pkts( p_lcb, p_msg ) )
    193         {
    194             /* nothing to do */
    195         }
    196         else
    197 #endif
    198             osi_free(p_msg);
    199     }
    200 #if (BLE_INCLUDED == TRUE)
    201     else if (rcv_cid == L2CAP_BLE_SIGNALLING_CID)
    202     {
    203         l2cble_process_sig_cmd (p_lcb, p, l2cap_len);
    204         osi_free(p_msg);
    205     }
    206 #endif
    207 #if (L2CAP_NUM_FIXED_CHNLS > 0)
    208     else if ((rcv_cid >= L2CAP_FIRST_FIXED_CHNL) && (rcv_cid <= L2CAP_LAST_FIXED_CHNL) &&
    209              (l2cb.fixed_reg[rcv_cid - L2CAP_FIRST_FIXED_CHNL].pL2CA_FixedData_Cb != NULL) )
    210     {
    211         /* If no CCB for this channel, allocate one */
    212         if (p_lcb &&
    213             /* only process fixed channel data when link is open or wait for data indication */
    214             (p_lcb->link_state != LST_DISCONNECTING) &&
    215             l2cu_initialize_fixed_ccb (p_lcb, rcv_cid, &l2cb.fixed_reg[rcv_cid - L2CAP_FIRST_FIXED_CHNL].fixed_chnl_opts))
    216         {
    217             p_ccb = p_lcb->p_fixed_ccbs[rcv_cid - L2CAP_FIRST_FIXED_CHNL];
    218 
    219             if (p_ccb->peer_cfg.fcr.mode != L2CAP_FCR_BASIC_MODE)
    220                 l2c_fcr_proc_pdu (p_ccb, p_msg);
    221             else
    222                 (*l2cb.fixed_reg[rcv_cid - L2CAP_FIRST_FIXED_CHNL].pL2CA_FixedData_Cb)
    223                     (rcv_cid, p_lcb->remote_bd_addr, p_msg);
    224         }
    225         else
    226             osi_free(p_msg);
    227     }
    228 #endif
    229 
    230     else
    231     {
    232         if (p_ccb == NULL)
    233             osi_free(p_msg);
    234         else
    235         {
    236             if (p_lcb->transport == BT_TRANSPORT_LE)
    237             {
    238                l2c_lcc_proc_pdu(p_ccb,p_msg);
    239                // Got a pkt, valid send out credits to the peer device
    240                credit = L2CAP_LE_DEFAULT_CREDIT;
    241                l2c_csm_execute(p_ccb, L2CEVT_L2CA_SEND_FLOW_CONTROL_CREDIT, &credit);
    242             }
    243             else
    244             {
    245                 /* Basic mode packets go straight to the state machine */
    246                 if (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_BASIC_MODE)
    247                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_DATA, p_msg);
    248                 else
    249                 {
    250                     /* eRTM or streaming mode, so we need to validate states first */
    251                     if ((p_ccb->chnl_state == CST_OPEN) || (p_ccb->chnl_state == CST_CONFIG))
    252                         l2c_fcr_proc_pdu (p_ccb, p_msg);
    253                     else
    254                         osi_free (p_msg);
    255                 }
    256             }
    257         }
    258     }
    259 }
    260 
    261 /*******************************************************************************
    262 **
    263 ** Function         process_l2cap_cmd
    264 **
    265 ** Description      This function is called when a packet is received on the
    266 **                  L2CAP signalling CID
    267 **
    268 ** Returns          void
    269 **
    270 *******************************************************************************/
    271 static void process_l2cap_cmd (tL2C_LCB *p_lcb, UINT8 *p, UINT16 pkt_len)
    272 {
    273     UINT8           *p_pkt_end, *p_next_cmd, *p_cfg_end, *p_cfg_start;
    274     UINT8           cmd_code, cfg_code, cfg_len, id;
    275     tL2C_CONN_INFO  con_info;
    276     tL2CAP_CFG_INFO cfg_info;
    277     UINT16          rej_reason, rej_mtu, lcid, rcid, info_type;
    278     tL2C_CCB        *p_ccb;
    279     tL2C_RCB        *p_rcb;
    280     BOOLEAN         cfg_rej, pkt_size_rej = FALSE;
    281     UINT16          cfg_rej_len, cmd_len;
    282     UINT16          result;
    283     tL2C_CONN_INFO  ci;
    284 
    285 #if (defined BLE_INCLUDED && BLE_INCLUDED == TRUE)
    286     /* if l2cap command received in CID 1 on top of an LE link, ignore this command */
    287     if (p_lcb->transport == BT_TRANSPORT_LE)
    288         return;
    289 #endif
    290 
    291     /* Reject the packet if it exceeds the default Signalling Channel MTU */
    292     if (pkt_len > L2CAP_DEFAULT_MTU)
    293     {
    294         /* Core Spec requires a single response to the first command found in a multi-command
    295         ** L2cap packet.  If only responses in the packet, then it will be ignored.
    296         ** Here we simply mark the bad packet and decide which cmd ID to reject later
    297         */
    298         pkt_size_rej = TRUE;
    299         L2CAP_TRACE_ERROR ("L2CAP SIG MTU Pkt Len Exceeded (672) -> pkt_len: %d", pkt_len);
    300     }
    301 
    302     p_next_cmd = p;
    303     p_pkt_end  = p + pkt_len;
    304 
    305     memset (&cfg_info, 0, sizeof(cfg_info));
    306 
    307     /* An L2CAP packet may contain multiple commands */
    308     while (TRUE)
    309     {
    310         /* Smallest command is 4 bytes */
    311         if ((p = p_next_cmd) > (p_pkt_end - 4))
    312             break;
    313 
    314         STREAM_TO_UINT8  (cmd_code, p);
    315         STREAM_TO_UINT8  (id, p);
    316         STREAM_TO_UINT16 (cmd_len, p);
    317 
    318         /* Check command length does not exceed packet length */
    319         if ((p_next_cmd = p + cmd_len) > p_pkt_end)
    320         {
    321             L2CAP_TRACE_WARNING ("Command len bad  pkt_len: %d  cmd_len: %d  code: %d",
    322                                   pkt_len, cmd_len, cmd_code);
    323             break;
    324         }
    325 
    326         L2CAP_TRACE_DEBUG ("cmd_code: %d, id:%d, cmd_len:%d", cmd_code, id, cmd_len);
    327 
    328         /* Bad L2CAP packet length, look or cmd to reject */
    329         if (pkt_size_rej)
    330         {
    331             /* If command found rejected it and we're done, otherwise keep looking */
    332             if (l2c_is_cmd_rejected(cmd_code, id, p_lcb))
    333                 return;
    334             else
    335                 continue; /* Look for next cmd/response in current packet */
    336         }
    337 
    338         switch (cmd_code)
    339         {
    340         case L2CAP_CMD_REJECT:
    341             STREAM_TO_UINT16 (rej_reason, p);
    342             if (rej_reason == L2CAP_CMD_REJ_MTU_EXCEEDED)
    343             {
    344                 STREAM_TO_UINT16 (rej_mtu, p);
    345                 /* What to do with the MTU reject ? We have negotiated an MTU. For now */
    346                 /* we will ignore it and let a higher protocol timeout take care of it */
    347 
    348                 L2CAP_TRACE_WARNING ("L2CAP - MTU rej Handle: %d MTU: %d", p_lcb->handle, rej_mtu);
    349             }
    350             if (rej_reason == L2CAP_CMD_REJ_INVALID_CID)
    351             {
    352                 STREAM_TO_UINT16 (rcid, p);
    353                 STREAM_TO_UINT16 (lcid, p);
    354 
    355                 L2CAP_TRACE_WARNING ("L2CAP - rej with CID invalid, LCID: 0x%04x RCID: 0x%04x", lcid, rcid);
    356 
    357                 /* Remote CID invalid. Treat as a disconnect */
    358                 if (((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) != NULL)
    359                  && (p_ccb->remote_cid == rcid))
    360                 {
    361                     /* Fake link disconnect - no reply is generated */
    362                     l2c_csm_execute (p_ccb, L2CEVT_LP_DISCONNECT_IND, NULL);
    363                 }
    364             }
    365 
    366             /* SonyEricsson Info request Bug workaround (Continue connection) */
    367             else if (rej_reason == L2CAP_CMD_REJ_NOT_UNDERSTOOD && p_lcb->w4_info_rsp)
    368             {
    369                 alarm_cancel(p_lcb->info_resp_timer);
    370 
    371                 p_lcb->w4_info_rsp = FALSE;
    372                 ci.status = HCI_SUCCESS;
    373                 memcpy (ci.bd_addr, p_lcb->remote_bd_addr, sizeof(BD_ADDR));
    374 
    375                 /* For all channels, send the event through their FSMs */
    376                 for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; p_ccb = p_ccb->p_next_ccb)
    377                 {
    378                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_INFO_RSP, &ci);
    379                 }
    380             }
    381             break;
    382 
    383         case L2CAP_CMD_CONN_REQ:
    384             STREAM_TO_UINT16 (con_info.psm, p);
    385             STREAM_TO_UINT16 (rcid, p);
    386             if ((p_rcb = l2cu_find_rcb_by_psm (con_info.psm)) == NULL)
    387             {
    388                 L2CAP_TRACE_WARNING ("L2CAP - rcvd conn req for unknown PSM: %d", con_info.psm);
    389                 l2cu_reject_connection (p_lcb, rcid, id, L2CAP_CONN_NO_PSM);
    390                 break;
    391             }
    392             else
    393             {
    394                 if (!p_rcb->api.pL2CA_ConnectInd_Cb)
    395                 {
    396                     L2CAP_TRACE_WARNING ("L2CAP - rcvd conn req for outgoing-only connection PSM: %d", con_info.psm);
    397                     l2cu_reject_connection (p_lcb, rcid, id, L2CAP_CONN_NO_PSM);
    398                     break;
    399                 }
    400             }
    401             if ((p_ccb = l2cu_allocate_ccb (p_lcb, 0)) == NULL)
    402             {
    403                 L2CAP_TRACE_ERROR ("L2CAP - unable to allocate CCB");
    404                 l2cu_reject_connection (p_lcb, rcid, id, L2CAP_CONN_NO_RESOURCES);
    405                 break;
    406             }
    407             p_ccb->remote_id = id;
    408             p_ccb->p_rcb = p_rcb;
    409             p_ccb->remote_cid = rcid;
    410 
    411             l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONNECT_REQ, &con_info);
    412             break;
    413 
    414         case L2CAP_CMD_CONN_RSP:
    415             STREAM_TO_UINT16 (con_info.remote_cid, p);
    416             STREAM_TO_UINT16 (lcid, p);
    417             STREAM_TO_UINT16 (con_info.l2cap_result, p);
    418             STREAM_TO_UINT16 (con_info.l2cap_status, p);
    419 
    420             if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) == NULL)
    421             {
    422                 L2CAP_TRACE_WARNING ("L2CAP - no CCB for conn rsp, LCID: %d RCID: %d",
    423                                       lcid, con_info.remote_cid);
    424                 break;
    425             }
    426             if (p_ccb->local_id != id)
    427             {
    428                 L2CAP_TRACE_WARNING ("L2CAP - con rsp - bad ID. Exp: %d Got: %d",
    429                                       p_ccb->local_id, id);
    430                 break;
    431             }
    432 
    433             if (con_info.l2cap_result == L2CAP_CONN_OK)
    434                 l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONNECT_RSP, &con_info);
    435             else if (con_info.l2cap_result == L2CAP_CONN_PENDING)
    436                 l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONNECT_RSP_PND, &con_info);
    437             else
    438                 l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONNECT_RSP_NEG, &con_info);
    439 
    440             break;
    441 
    442         case L2CAP_CMD_CONFIG_REQ:
    443             p_cfg_end = p + cmd_len;
    444             cfg_rej = FALSE;
    445             cfg_rej_len = 0;
    446 
    447             STREAM_TO_UINT16 (lcid, p);
    448             STREAM_TO_UINT16 (cfg_info.flags, p);
    449 
    450             p_cfg_start = p;
    451 
    452             cfg_info.flush_to_present = cfg_info.mtu_present = cfg_info.qos_present =
    453                 cfg_info.fcr_present = cfg_info.fcs_present = FALSE;
    454 
    455             while (p < p_cfg_end)
    456             {
    457                 STREAM_TO_UINT8 (cfg_code, p);
    458                 STREAM_TO_UINT8 (cfg_len, p);
    459 
    460                 switch (cfg_code & 0x7F)
    461                 {
    462                 case L2CAP_CFG_TYPE_MTU:
    463                     cfg_info.mtu_present = TRUE;
    464                     STREAM_TO_UINT16 (cfg_info.mtu, p);
    465                     break;
    466 
    467                 case L2CAP_CFG_TYPE_FLUSH_TOUT:
    468                     cfg_info.flush_to_present = TRUE;
    469                     STREAM_TO_UINT16 (cfg_info.flush_to, p);
    470                     break;
    471 
    472                 case L2CAP_CFG_TYPE_QOS:
    473                     cfg_info.qos_present = TRUE;
    474                     STREAM_TO_UINT8  (cfg_info.qos.qos_flags, p);
    475                     STREAM_TO_UINT8  (cfg_info.qos.service_type, p);
    476                     STREAM_TO_UINT32 (cfg_info.qos.token_rate, p);
    477                     STREAM_TO_UINT32 (cfg_info.qos.token_bucket_size, p);
    478                     STREAM_TO_UINT32 (cfg_info.qos.peak_bandwidth, p);
    479                     STREAM_TO_UINT32 (cfg_info.qos.latency, p);
    480                     STREAM_TO_UINT32 (cfg_info.qos.delay_variation, p);
    481                     break;
    482 
    483                 case L2CAP_CFG_TYPE_FCR:
    484                     cfg_info.fcr_present = TRUE;
    485                     STREAM_TO_UINT8 (cfg_info.fcr.mode, p);
    486                     STREAM_TO_UINT8 (cfg_info.fcr.tx_win_sz, p);
    487                     STREAM_TO_UINT8 (cfg_info.fcr.max_transmit, p);
    488                     STREAM_TO_UINT16 (cfg_info.fcr.rtrans_tout, p);
    489                     STREAM_TO_UINT16 (cfg_info.fcr.mon_tout, p);
    490                     STREAM_TO_UINT16 (cfg_info.fcr.mps, p);
    491                     break;
    492 
    493                 case L2CAP_CFG_TYPE_FCS:
    494                     cfg_info.fcs_present = TRUE;
    495                     STREAM_TO_UINT8 (cfg_info.fcs, p);
    496                     break;
    497 
    498                 case L2CAP_CFG_TYPE_EXT_FLOW:
    499                     cfg_info.ext_flow_spec_present = TRUE;
    500                     STREAM_TO_UINT8  (cfg_info.ext_flow_spec.id, p);
    501                     STREAM_TO_UINT8  (cfg_info.ext_flow_spec.stype, p);
    502                     STREAM_TO_UINT16 (cfg_info.ext_flow_spec.max_sdu_size, p);
    503                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.sdu_inter_time, p);
    504                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.access_latency, p);
    505                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.flush_timeout, p);
    506                     break;
    507 
    508                 default:
    509                     /* sanity check option length */
    510                     if ((cfg_len + L2CAP_CFG_OPTION_OVERHEAD) <= cmd_len)
    511                     {
    512                         p += cfg_len;
    513                         if ((cfg_code & 0x80) == 0)
    514                         {
    515                             cfg_rej_len += cfg_len + L2CAP_CFG_OPTION_OVERHEAD;
    516                             cfg_rej = TRUE;
    517                         }
    518                     }
    519                     /* bad length; force loop exit */
    520                     else
    521                     {
    522                         p = p_cfg_end;
    523                         cfg_rej = TRUE;
    524                     }
    525                     break;
    526                 }
    527             }
    528 
    529             if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) != NULL)
    530             {
    531                 p_ccb->remote_id = id;
    532                 if (cfg_rej)
    533                 {
    534                     l2cu_send_peer_config_rej (p_ccb, p_cfg_start, (UINT16) (cmd_len - L2CAP_CONFIG_REQ_LEN), cfg_rej_len);
    535                 }
    536                 else
    537                 {
    538                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_CONFIG_REQ, &cfg_info);
    539                 }
    540             }
    541             else
    542             {
    543                 /* updated spec says send command reject on invalid cid */
    544                 l2cu_send_peer_cmd_reject (p_lcb, L2CAP_CMD_REJ_INVALID_CID, id, 0, 0);
    545             }
    546             break;
    547 
    548         case L2CAP_CMD_CONFIG_RSP:
    549             p_cfg_end = p + cmd_len;
    550             STREAM_TO_UINT16 (lcid, p);
    551             STREAM_TO_UINT16 (cfg_info.flags, p);
    552             STREAM_TO_UINT16 (cfg_info.result, p);
    553 
    554             cfg_info.flush_to_present = cfg_info.mtu_present = cfg_info.qos_present =
    555                 cfg_info.fcr_present = cfg_info.fcs_present = FALSE;
    556 
    557             while (p < p_cfg_end)
    558             {
    559                 STREAM_TO_UINT8 (cfg_code, p);
    560                 STREAM_TO_UINT8 (cfg_len, p);
    561 
    562                 switch (cfg_code & 0x7F)
    563                 {
    564                 case L2CAP_CFG_TYPE_MTU:
    565                     cfg_info.mtu_present = TRUE;
    566                     STREAM_TO_UINT16 (cfg_info.mtu, p);
    567                     break;
    568 
    569                 case L2CAP_CFG_TYPE_FLUSH_TOUT:
    570                     cfg_info.flush_to_present = TRUE;
    571                     STREAM_TO_UINT16 (cfg_info.flush_to, p);
    572                     break;
    573 
    574                 case L2CAP_CFG_TYPE_QOS:
    575                     cfg_info.qos_present = TRUE;
    576                     STREAM_TO_UINT8  (cfg_info.qos.qos_flags, p);
    577                     STREAM_TO_UINT8  (cfg_info.qos.service_type, p);
    578                     STREAM_TO_UINT32 (cfg_info.qos.token_rate, p);
    579                     STREAM_TO_UINT32 (cfg_info.qos.token_bucket_size, p);
    580                     STREAM_TO_UINT32 (cfg_info.qos.peak_bandwidth, p);
    581                     STREAM_TO_UINT32 (cfg_info.qos.latency, p);
    582                     STREAM_TO_UINT32 (cfg_info.qos.delay_variation, p);
    583                     break;
    584 
    585                 case L2CAP_CFG_TYPE_FCR:
    586                     cfg_info.fcr_present = TRUE;
    587                     STREAM_TO_UINT8 (cfg_info.fcr.mode, p);
    588                     STREAM_TO_UINT8 (cfg_info.fcr.tx_win_sz, p);
    589                     STREAM_TO_UINT8 (cfg_info.fcr.max_transmit, p);
    590                     STREAM_TO_UINT16 (cfg_info.fcr.rtrans_tout, p);
    591                     STREAM_TO_UINT16 (cfg_info.fcr.mon_tout, p);
    592                     STREAM_TO_UINT16 (cfg_info.fcr.mps, p);
    593                     break;
    594 
    595                 case L2CAP_CFG_TYPE_FCS:
    596                     cfg_info.fcs_present = TRUE;
    597                     STREAM_TO_UINT8 (cfg_info.fcs, p);
    598                     break;
    599 
    600                 case L2CAP_CFG_TYPE_EXT_FLOW:
    601                     cfg_info.ext_flow_spec_present = TRUE;
    602                     STREAM_TO_UINT8  (cfg_info.ext_flow_spec.id, p);
    603                     STREAM_TO_UINT8  (cfg_info.ext_flow_spec.stype, p);
    604                     STREAM_TO_UINT16 (cfg_info.ext_flow_spec.max_sdu_size, p);
    605                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.sdu_inter_time, p);
    606                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.access_latency, p);
    607                     STREAM_TO_UINT32 (cfg_info.ext_flow_spec.flush_timeout, p);
    608                     break;
    609                 }
    610             }
    611 
    612             if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) != NULL)
    613             {
    614                 if (p_ccb->local_id != id)
    615                 {
    616                     L2CAP_TRACE_WARNING ("L2CAP - cfg rsp - bad ID. Exp: %d Got: %d",
    617                                           p_ccb->local_id, id);
    618                     break;
    619                 }
    620                 if ( (cfg_info.result == L2CAP_CFG_OK) || (cfg_info.result == L2CAP_CFG_PENDING) )
    621                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_CONFIG_RSP, &cfg_info);
    622                 else
    623                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_CONFIG_RSP_NEG, &cfg_info);
    624             }
    625             else
    626             {
    627                 L2CAP_TRACE_WARNING ("L2CAP - rcvd cfg rsp for unknown CID: 0x%04x", lcid);
    628             }
    629             break;
    630 
    631         case L2CAP_CMD_DISC_REQ:
    632             STREAM_TO_UINT16 (lcid, p);
    633             STREAM_TO_UINT16 (rcid, p);
    634 
    635             if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) != NULL)
    636             {
    637                 if (p_ccb->remote_cid == rcid)
    638                 {
    639                     p_ccb->remote_id = id;
    640                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_DISCONNECT_REQ, &con_info);
    641                 }
    642             }
    643             else
    644                 l2cu_send_peer_disc_rsp (p_lcb, id, lcid, rcid);
    645 
    646             break;
    647 
    648         case L2CAP_CMD_DISC_RSP:
    649             STREAM_TO_UINT16 (rcid, p);
    650             STREAM_TO_UINT16 (lcid, p);
    651 
    652             if ((p_ccb = l2cu_find_ccb_by_cid (p_lcb, lcid)) != NULL)
    653             {
    654                 if ((p_ccb->remote_cid == rcid) && (p_ccb->local_id == id))
    655                 {
    656                     l2c_csm_execute (p_ccb, L2CEVT_L2CAP_DISCONNECT_RSP, &con_info);
    657                 }
    658             }
    659             break;
    660 
    661         case L2CAP_CMD_ECHO_REQ:
    662             l2cu_send_peer_echo_rsp (p_lcb, id, NULL, 0);
    663             break;
    664 
    665         case L2CAP_CMD_ECHO_RSP:
    666             if (p_lcb->p_echo_rsp_cb)
    667             {
    668                 tL2CA_ECHO_RSP_CB *p_cb = p_lcb->p_echo_rsp_cb;
    669 
    670                 /* Zero out the callback in case app immediately calls us again */
    671                 p_lcb->p_echo_rsp_cb = NULL;
    672 
    673                 (*p_cb) (L2CAP_PING_RESULT_OK);
    674             }
    675             break;
    676 
    677         case L2CAP_CMD_INFO_REQ:
    678             STREAM_TO_UINT16 (info_type, p);
    679             l2cu_send_peer_info_rsp (p_lcb, id, info_type);
    680             break;
    681 
    682         case L2CAP_CMD_INFO_RSP:
    683             /* Stop the link connect timer if sent before L2CAP connection is up */
    684             if (p_lcb->w4_info_rsp)
    685             {
    686                 alarm_cancel(p_lcb->info_resp_timer);
    687                 p_lcb->w4_info_rsp = FALSE;
    688             }
    689 
    690             STREAM_TO_UINT16 (info_type, p);
    691             STREAM_TO_UINT16 (result, p);
    692 
    693             p_lcb->info_rx_bits |= (1 << info_type);
    694 
    695             if ( (info_type == L2CAP_EXTENDED_FEATURES_INFO_TYPE)
    696               && (result == L2CAP_INFO_RESP_RESULT_SUCCESS) )
    697             {
    698                 STREAM_TO_UINT32( p_lcb->peer_ext_fea, p );
    699 
    700 #if (L2CAP_NUM_FIXED_CHNLS > 0)
    701                 if (p_lcb->peer_ext_fea & L2CAP_EXTFEA_FIXED_CHNLS)
    702                 {
    703                     l2cu_send_peer_info_req (p_lcb, L2CAP_FIXED_CHANNELS_INFO_TYPE);
    704                     break;
    705                 }
    706                 else
    707                 {
    708                     l2cu_process_fixed_chnl_resp (p_lcb);
    709                 }
    710 #endif
    711             }
    712 
    713 #if (L2CAP_NUM_FIXED_CHNLS > 0)
    714             if (info_type == L2CAP_FIXED_CHANNELS_INFO_TYPE)
    715             {
    716                 if (result == L2CAP_INFO_RESP_RESULT_SUCCESS)
    717                 {
    718                     memcpy (p_lcb->peer_chnl_mask, p, L2CAP_FIXED_CHNL_ARRAY_SIZE);
    719                 }
    720 
    721                 l2cu_process_fixed_chnl_resp (p_lcb);
    722             }
    723 #endif
    724 #if (L2CAP_UCD_INCLUDED == TRUE)
    725             else if (info_type == L2CAP_CONNLESS_MTU_INFO_TYPE)
    726             {
    727                 if (result == L2CAP_INFO_RESP_RESULT_SUCCESS)
    728                 {
    729                     STREAM_TO_UINT16 (p_lcb->ucd_mtu, p);
    730                 }
    731             }
    732 #endif
    733 
    734             ci.status = HCI_SUCCESS;
    735             memcpy (ci.bd_addr, p_lcb->remote_bd_addr, sizeof(BD_ADDR));
    736             for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; p_ccb = p_ccb->p_next_ccb)
    737             {
    738                 l2c_csm_execute (p_ccb, L2CEVT_L2CAP_INFO_RSP, &ci);
    739             }
    740             break;
    741 
    742         default:
    743             L2CAP_TRACE_WARNING ("L2CAP - bad cmd code: %d", cmd_code);
    744             l2cu_send_peer_cmd_reject (p_lcb, L2CAP_CMD_REJ_NOT_UNDERSTOOD, id, 0, 0);
    745             return;
    746         }
    747     }
    748 }
    749 
    750 /*******************************************************************************
    751 **
    752 ** Function         l2c_process_held_packets
    753 **
    754 ** Description      This function processes any L2CAP packets that arrived before
    755 **                  the HCI connection complete arrived. It is a work around for
    756 **                  badly behaved controllers.
    757 **
    758 ** Returns          void
    759 **
    760 *******************************************************************************/
    761 void l2c_process_held_packets(BOOLEAN timed_out) {
    762     if (list_is_empty(l2cb.rcv_pending_q))
    763         return;
    764 
    765     if (!timed_out) {
    766         alarm_cancel(l2cb.receive_hold_timer);
    767         L2CAP_TRACE_WARNING("L2CAP HOLD CONTINUE");
    768     } else {
    769         L2CAP_TRACE_WARNING("L2CAP HOLD TIMEOUT");
    770     }
    771 
    772     for (const list_node_t *node = list_begin(l2cb.rcv_pending_q);
    773         node != list_end(l2cb.rcv_pending_q);)  {
    774         BT_HDR *p_buf = list_node(node);
    775         node = list_next(node);
    776         if (!timed_out || (!p_buf->layer_specific) || (--p_buf->layer_specific == 0)) {
    777             list_remove(l2cb.rcv_pending_q, p_buf);
    778             p_buf->layer_specific = 0xFFFF;
    779             l2c_rcv_acl_data(p_buf);
    780         }
    781     }
    782 
    783     /* If anyone still in the queue, restart the timeout */
    784     if (!list_is_empty(l2cb.rcv_pending_q)) {
    785         alarm_set_on_queue(l2cb.receive_hold_timer, BT_1SEC_TIMEOUT_MS,
    786                            l2c_receive_hold_timer_timeout, NULL,
    787                            btu_general_alarm_queue);
    788     }
    789 }
    790 
    791 /*******************************************************************************
    792 **
    793 ** Function         l2c_init
    794 **
    795 ** Description      This function is called once at startup to initialize
    796 **                  all the L2CAP structures
    797 **
    798 ** Returns          void
    799 **
    800 *******************************************************************************/
    801 void l2c_init (void)
    802 {
    803     INT16  xx;
    804 
    805     memset (&l2cb, 0, sizeof (tL2C_CB));
    806     /* the psm is increased by 2 before being used */
    807     l2cb.dyn_psm = 0xFFF;
    808 
    809     /* Put all the channel control blocks on the free queue */
    810     for (xx = 0; xx < MAX_L2CAP_CHANNELS - 1; xx++)
    811     {
    812         l2cb.ccb_pool[xx].p_next_ccb = &l2cb.ccb_pool[xx + 1];
    813     }
    814 
    815 #if (L2CAP_NON_FLUSHABLE_PB_INCLUDED == TRUE)
    816     /* it will be set to L2CAP_PKT_START_NON_FLUSHABLE if controller supports */
    817     l2cb.non_flushable_pbf = L2CAP_PKT_START << L2CAP_PKT_TYPE_SHIFT;
    818 #endif
    819 
    820     l2cb.p_free_ccb_first = &l2cb.ccb_pool[0];
    821     l2cb.p_free_ccb_last  = &l2cb.ccb_pool[MAX_L2CAP_CHANNELS - 1];
    822 
    823 #ifdef L2CAP_DESIRED_LINK_ROLE
    824     l2cb.desire_role      = L2CAP_DESIRED_LINK_ROLE;
    825 #else
    826     l2cb.desire_role      = HCI_ROLE_SLAVE;
    827 #endif
    828 
    829     /* Set the default idle timeout */
    830     l2cb.idle_timeout = L2CAP_LINK_INACTIVITY_TOUT;
    831 
    832 #if defined(L2CAP_INITIAL_TRACE_LEVEL)
    833     l2cb.l2cap_trace_level = L2CAP_INITIAL_TRACE_LEVEL;
    834 #else
    835     l2cb.l2cap_trace_level = BT_TRACE_LEVEL_NONE;    /* No traces */
    836 #endif
    837 
    838 #if L2CAP_CONFORMANCE_TESTING == TRUE
    839      /* Conformance testing needs a dynamic response */
    840     l2cb.test_info_resp = L2CAP_EXTFEA_SUPPORTED_MASK;
    841 #endif
    842 
    843     /* Number of ACL buffers to use for high priority channel */
    844 #if (defined(L2CAP_HIGH_PRI_CHAN_QUOTA_IS_CONFIGURABLE) && (L2CAP_HIGH_PRI_CHAN_QUOTA_IS_CONFIGURABLE == TRUE))
    845     l2cb.high_pri_min_xmit_quota = L2CAP_HIGH_PRI_MIN_XMIT_QUOTA;
    846 #endif
    847 
    848 #if BLE_INCLUDED == TRUE
    849     l2cb.l2c_ble_fixed_chnls_mask =
    850          L2CAP_FIXED_CHNL_ATT_BIT | L2CAP_FIXED_CHNL_BLE_SIG_BIT | L2CAP_FIXED_CHNL_SMP_BIT;
    851 #endif
    852 
    853     l2cb.rcv_pending_q = list_new(NULL);
    854     if (l2cb.rcv_pending_q == NULL)
    855         LOG_ERROR(LOG_TAG, "%s unable to allocate memory for link layer control block", __func__);
    856     l2cb.receive_hold_timer = alarm_new("l2c.receive_hold_timer");
    857 }
    858 
    859 void l2c_free(void) {
    860     list_free(l2cb.rcv_pending_q);
    861     l2cb.rcv_pending_q = NULL;
    862 }
    863 
    864 void l2c_receive_hold_timer_timeout(UNUSED_ATTR void *data)
    865 {
    866     /* Update the timeouts in the hold queue */
    867     l2c_process_held_packets(TRUE);
    868 }
    869 
    870 void l2c_ccb_timer_timeout(void *data)
    871 {
    872     tL2C_CCB *p_ccb = (tL2C_CCB *)data;
    873 
    874     l2c_csm_execute(p_ccb, L2CEVT_TIMEOUT, NULL);
    875 }
    876 
    877 void l2c_fcrb_ack_timer_timeout(void *data)
    878 {
    879     tL2C_CCB *p_ccb = (tL2C_CCB *)data;
    880 
    881     l2c_csm_execute(p_ccb, L2CEVT_ACK_TIMEOUT, NULL);
    882 }
    883 
    884 void l2c_lcb_timer_timeout(void *data)
    885 {
    886     tL2C_LCB *p_lcb = (tL2C_LCB *)data;
    887 
    888     l2c_link_timeout(p_lcb);
    889 }
    890 
    891 /*******************************************************************************
    892 **
    893 ** Function         l2c_data_write
    894 **
    895 ** Description      API functions call this function to write data.
    896 **
    897 ** Returns          L2CAP_DW_SUCCESS, if data accepted, else FALSE
    898 **                  L2CAP_DW_CONGESTED, if data accepted and the channel is congested
    899 **                  L2CAP_DW_FAILED, if error
    900 **
    901 *******************************************************************************/
    902 UINT8 l2c_data_write (UINT16 cid, BT_HDR *p_data, UINT16 flags)
    903 {
    904     tL2C_CCB        *p_ccb;
    905 
    906     /* Find the channel control block. We don't know the link it is on. */
    907     if ((p_ccb = l2cu_find_ccb_by_cid (NULL, cid)) == NULL)
    908     {
    909         L2CAP_TRACE_WARNING ("L2CAP - no CCB for L2CA_DataWrite, CID: %d", cid);
    910         osi_free(p_data);
    911         return (L2CAP_DW_FAILED);
    912     }
    913 
    914 #ifndef TESTER /* Tester may send any amount of data. otherwise sending message
    915                   bigger than mtu size of peer is a violation of protocol */
    916     UINT16 mtu;
    917 
    918     if (p_ccb->p_lcb->transport == BT_TRANSPORT_LE)
    919         mtu = p_ccb->peer_conn_cfg.mtu;
    920     else
    921         mtu = p_ccb->peer_cfg.mtu;
    922 
    923     if (p_data->len > mtu)
    924     {
    925         L2CAP_TRACE_WARNING ("L2CAP - CID: 0x%04x  cannot send message bigger than peer's mtu size", cid);
    926         osi_free(p_data);
    927         return (L2CAP_DW_FAILED);
    928     }
    929 #endif
    930 
    931     /* channel based, packet based flushable or non-flushable */
    932     p_data->layer_specific = flags;
    933 
    934     /* If already congested, do not accept any more packets */
    935     if (p_ccb->cong_sent)
    936     {
    937         L2CAP_TRACE_ERROR ("L2CAP - CID: 0x%04x cannot send, already congested  xmit_hold_q.count: %u  buff_quota: %u",
    938                            p_ccb->local_cid,
    939                            fixed_queue_length(p_ccb->xmit_hold_q),
    940                            p_ccb->buff_quota);
    941 
    942         osi_free(p_data);
    943         return (L2CAP_DW_FAILED);
    944     }
    945 
    946 
    947     l2c_csm_execute (p_ccb, L2CEVT_L2CA_DATA_WRITE, p_data);
    948 
    949     if (p_ccb->cong_sent)
    950         return (L2CAP_DW_CONGESTED);
    951 
    952     return (L2CAP_DW_SUCCESS);
    953 }
    954 
    955