/******************************************************************************
*
* Copyright 1999-2012 Broadcom Corporation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
******************************************************************************/
/******************************************************************************
*
* This file contains the main L2CAP entry points
*
******************************************************************************/
#define LOG_TAG "bt_l2c_main"
#include <string.h>
#include "bt_common.h"
#include "bt_target.h"
#include "hci/include/btsnoop.h"
#include "hcimsgs.h"
#include "l2c_api.h"
#include "l2c_int.h"
#include "l2cdefs.h"
#include "main/shim/shim.h"
#include "osi/include/log.h"
#include "osi/include/osi.h"
/******************************************************************************/
/* L O C A L F U N C T I O N P R O T O T Y P E S */
/******************************************************************************/
static void process_l2cap_cmd(tL2C_LCB* p_lcb, uint8_t* p, uint16_t pkt_len);
/******************************************************************************/
/* G L O B A L L 2 C A P D A T A */
/******************************************************************************/
tL2C_CB l2cb;
/*******************************************************************************
*
* Function l2c_rcv_acl_data
*
* Description This function is called from the HCI Interface when an ACL
* data packet is received.
*
* Returns void
*
******************************************************************************/
void l2c_rcv_acl_data(BT_HDR* p_msg) {
uint8_t* p = (uint8_t*)(p_msg + 1) + p_msg->offset;
/* Extract the handle */
uint16_t handle;
STREAM_TO_UINT16(handle, p);
uint8_t pkt_type = HCID_GET_EVENT(handle);
handle = HCID_GET_HANDLE(handle);
/* Since the HCI Transport is putting segmented packets back together, we */
/* should never get a valid packet with the type set to "continuation" */
if (pkt_type == L2CAP_PKT_CONTINUE) {
L2CAP_TRACE_WARNING("L2CAP - received packet continuation");
osi_free(p_msg);
return;
}
uint16_t hci_len;
STREAM_TO_UINT16(hci_len, p);
if (hci_len < L2CAP_PKT_OVERHEAD || hci_len != p_msg->len - 4) {
/* Remote-declared packet size must match HCI_ACL size - ACL header (4) */
L2CAP_TRACE_WARNING("L2CAP - got incorrect hci header");
osi_free(p_msg);
return;
}
uint16_t l2cap_len, rcv_cid;
STREAM_TO_UINT16(l2cap_len, p);
STREAM_TO_UINT16(rcv_cid, p);
/* Find the LCB based on the handle */
tL2C_LCB* p_lcb = l2cu_find_lcb_by_handle(handle);
if (!p_lcb) {
/* There is a slight possibility (specifically with USB) that we get an */
/* L2CAP connection request before we get the HCI connection complete. */
/* So for these types of messages, hold them for up to 2 seconds. */
if (l2cap_len == 0) {
L2CAP_TRACE_WARNING("received empty L2CAP packet");
osi_free(p_msg);
return;
}
uint8_t cmd_code;
STREAM_TO_UINT8(cmd_code, p);
if ((p_msg->layer_specific != 0) || (rcv_cid != L2CAP_SIGNALLING_CID) ||
(cmd_code != L2CAP_CMD_INFO_REQ && cmd_code != L2CAP_CMD_CONN_REQ)) {
bool qcom_debug_log = (handle == 3804 && ((rcv_cid & 0xff) == 0xff) &&
p_msg->layer_specific == 0);
if (!qcom_debug_log) {
L2CAP_TRACE_ERROR(
"L2CAP - rcvd ACL for unknown handle:%d ls:%d cid:%d opcode:%d cur "
"count:%d",
handle, p_msg->layer_specific, rcv_cid, cmd_code,
list_length(l2cb.rcv_pending_q));
}
osi_free(p_msg);
return;
}
L2CAP_TRACE_WARNING(
"L2CAP - holding ACL for unknown handle:%d ls:%d cid:%d opcode:%d cur "
"count:%d",
handle, p_msg->layer_specific, rcv_cid, cmd_code,
list_length(l2cb.rcv_pending_q));
p_msg->layer_specific = 2;
list_append(l2cb.rcv_pending_q, p_msg);
if (list_length(l2cb.rcv_pending_q) == 1) {
alarm_set_on_mloop(l2cb.receive_hold_timer, BT_1SEC_TIMEOUT_MS,
l2c_receive_hold_timer_timeout, NULL);
}
return;
}
/* Update the buffer header */
p_msg->offset += 4;
/* for BLE channel, always notify connection when ACL data received on the
* link */
if (p_lcb && p_lcb->transport == BT_TRANSPORT_LE &&
p_lcb->link_state != LST_DISCONNECTING) {
/* only process fixed channel data as channel open indication when link is
* not in disconnecting mode */
l2cble_notify_le_connection(p_lcb->remote_bd_addr);
}
/* Find the CCB for this CID */
tL2C_CCB* p_ccb = NULL;
if (rcv_cid >= L2CAP_BASE_APPL_CID) {
p_ccb = l2cu_find_ccb_by_cid(p_lcb, rcv_cid);
if (!p_ccb) {
L2CAP_TRACE_WARNING("L2CAP - unknown CID: 0x%04x", rcv_cid);
osi_free(p_msg);
return;
}
}
p_msg->len = hci_len - L2CAP_PKT_OVERHEAD;
p_msg->offset += L2CAP_PKT_OVERHEAD;
if (l2cap_len != p_msg->len) {
L2CAP_TRACE_WARNING("L2CAP - bad length in pkt. Exp: %d Act: %d",
l2cap_len, p_msg->len);
osi_free(p_msg);
return;
}
/* Send the data through the channel state machine */
if (rcv_cid == L2CAP_SIGNALLING_CID) {
process_l2cap_cmd(p_lcb, p, l2cap_len);
osi_free(p_msg);
return;
}
if (rcv_cid == L2CAP_CONNECTIONLESS_CID) {
/* process_connectionless_data (p_lcb); */
osi_free(p_msg);
return;
}
if (rcv_cid == L2CAP_BLE_SIGNALLING_CID) {
l2cble_process_sig_cmd(p_lcb, p, l2cap_len);
osi_free(p_msg);
return;
}
if ((rcv_cid >= L2CAP_FIRST_FIXED_CHNL) &&
(rcv_cid <= L2CAP_LAST_FIXED_CHNL) &&
(l2cb.fixed_reg[rcv_cid - L2CAP_FIRST_FIXED_CHNL].pL2CA_FixedData_Cb !=
NULL)) {
/* only process fixed channel data when link is open or wait for data
* indication */
if (!p_lcb || p_lcb->link_state == LST_DISCONNECTING ||
!l2cu_initialize_fixed_ccb(p_lcb, rcv_cid)) {
osi_free(p_msg);
return;
}
/* If no CCB for this channel, allocate one */
p_ccb = p_lcb->p_fixed_ccbs[rcv_cid - L2CAP_FIRST_FIXED_CHNL];
p_ccb->metrics.rx(p_msg->len);
if (p_ccb->peer_cfg.fcr.mode != L2CAP_FCR_BASIC_MODE)
l2c_fcr_proc_pdu(p_ccb, p_msg);
else
(*l2cb.fixed_reg[rcv_cid - L2CAP_FIRST_FIXED_CHNL].pL2CA_FixedData_Cb)(
rcv_cid, p_lcb->remote_bd_addr, p_msg);
return;
}
if (!p_ccb) {
osi_free(p_msg);
return;
}
if (p_lcb->transport == BT_TRANSPORT_LE) {
l2c_lcc_proc_pdu(p_ccb, p_msg);
/* The remote device has one less credit left */
--p_ccb->remote_credit_count;
/* If the credits left on the remote device are getting low, send some */
if (p_ccb->remote_credit_count <= L2CAP_LE_CREDIT_THRESHOLD) {
uint16_t credits = L2CAP_LE_CREDIT_DEFAULT - p_ccb->remote_credit_count;
p_ccb->remote_credit_count = L2CAP_LE_CREDIT_DEFAULT;
/* Return back credits */
l2c_csm_execute(p_ccb, L2CEVT_L2CA_SEND_FLOW_CONTROL_CREDIT, &credits);
}
} else {
/* Basic mode packets go straight to the state machine */
if (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_BASIC_MODE)
l2c_csm_execute(p_ccb, L2CEVT_L2CAP_DATA, p_msg);
else {
/* eRTM or streaming mode, so we need to validate states first */
if ((p_ccb->chnl_state == CST_OPEN) || (p_ccb->chnl_state == CST_CONFIG))
l2c_fcr_proc_pdu(p_ccb, p_msg);
else
osi_free(p_msg);
}
}
}
/*******************************************************************************
*
* Function process_l2cap_cmd
*
* Description This function is called when a packet is received on the
* L2CAP signalling CID
*
* Returns void
*
******************************************************************************/
static void process_l2cap_cmd(tL2C_LCB* p_lcb, uint8_t* p, uint16_t pkt_len) {
tL2C_CONN_INFO con_info;
/* if l2cap command received in CID 1 on top of an LE link, ignore this
* command */
if (p_lcb->transport == BT_TRANSPORT_LE) {
LOG_INFO("Dropping data on CID 1 for LE link");
return;
}
/* Reject the packet if it exceeds the default Signalling Channel MTU */
bool pkt_size_rej = false;
if (pkt_len > L2CAP_DEFAULT_MTU) {
/* Core Spec requires a single response to the first command found in a
* multi-command L2cap packet. If only responses in the packet, then it
* will be ignored. Here we simply mark the bad packet and decide which cmd
* ID to reject later */
pkt_size_rej = true;
LOG_WARN("Signaling pkt_len=%d exceeds MTU size %d", pkt_len,
L2CAP_DEFAULT_MTU);
}
uint8_t* p_next_cmd = p;
uint8_t* p_pkt_end = p + pkt_len;
tL2CAP_CFG_INFO cfg_info;
memset(&cfg_info, 0, sizeof(cfg_info));
/* An L2CAP packet may contain multiple commands */
while (true) {
/* Smallest command is 4 bytes */
p = p_next_cmd;
if (p > (p_pkt_end - 4)) break;
uint8_t cmd_code, id;
uint16_t cmd_len;
STREAM_TO_UINT8(cmd_code, p);
STREAM_TO_UINT8(id, p);
STREAM_TO_UINT16(cmd_len, p);
if (cmd_len > BT_SMALL_BUFFER_SIZE) {
LOG_WARN("Command size %u exceeds limit %d", cmd_len,
BT_SMALL_BUFFER_SIZE);
l2cu_send_peer_cmd_reject(p_lcb, L2CAP_CMD_REJ_MTU_EXCEEDED, id, 0, 0);
return;
}
/* Check command length does not exceed packet length */
p_next_cmd = p + cmd_len;
if (p_next_cmd > p_pkt_end) {
LOG_WARN("cmd_len > pkt_len, pkt_len=%d, cmd_len=%d, code=%d", pkt_len,
cmd_len, cmd_code);
break;
}
LOG_DEBUG("cmd_code: %d, id:%d, cmd_len:%d", cmd_code, id, cmd_len);
/* Bad L2CAP packet length, look for cmd to reject */
if (pkt_size_rej) {
/* If command found rejected it and we're done, otherwise keep looking */
if (l2c_is_cmd_rejected(cmd_code, id, p_lcb)) {
LOG_WARN("Rejected command %d due to bad packet length", cmd_code);
return;
} else {
LOG_WARN("No need to reject command %d for bad packet len", cmd_code);
continue; /* Look for next cmd/response in current packet */
}
}
switch (cmd_code) {
case L2CAP_CMD_REJECT:
uint16_t rej_reason;
if (p + 2 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CMD_REJECT");
return;
}
STREAM_TO_UINT16(rej_reason, p);
if (rej_reason == L2CAP_CMD_REJ_MTU_EXCEEDED) {
uint16_t rej_mtu;
if (p + 2 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CMD_REJ_MTU_EXCEEDED");
return;
}
STREAM_TO_UINT16(rej_mtu, p);
/* What to do with the MTU reject ? We have negotiated an MTU. For now
* we will ignore it and let a higher protocol timeout take care of it
*/
LOG_WARN("MTU rej Handle: %d MTU: %d", p_lcb->Handle(), rej_mtu);
}
if (rej_reason == L2CAP_CMD_REJ_INVALID_CID) {
uint16_t lcid, rcid;
if (p + 4 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CMD_REJ_INVALID_CID");
return;
}
STREAM_TO_UINT16(rcid, p);
STREAM_TO_UINT16(lcid, p);
LOG_WARN("Rejected due to invalid CID, LCID: 0x%04x RCID: 0x%04x",
lcid, rcid);
/* Remote CID invalid. Treat as a disconnect */
tL2C_CCB* p_ccb = l2cu_find_ccb_by_cid(p_lcb, lcid);
if ((p_ccb != NULL) && (p_ccb->remote_cid == rcid)) {
/* Fake link disconnect - no reply is generated */
LOG_WARN("Remote CID is invalid, treat as disconnected");
l2c_csm_execute(p_ccb, L2CEVT_LP_DISCONNECT_IND, NULL);
}
}
/* SonyEricsson Info request Bug workaround (Continue connection) */
else if (rej_reason == L2CAP_CMD_REJ_NOT_UNDERSTOOD &&
p_lcb->w4_info_rsp) {
alarm_cancel(p_lcb->info_resp_timer);
p_lcb->w4_info_rsp = false;
tL2C_CONN_INFO ci;
ci.status = HCI_SUCCESS;
ci.bd_addr = p_lcb->remote_bd_addr;
/* For all channels, send the event through their FSMs */
for (tL2C_CCB* p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;
p_ccb = p_ccb->p_next_ccb) {
l2c_csm_execute(p_ccb, L2CEVT_L2CAP_INFO_RSP, &ci);
}
}
break;
case L2CAP_CMD_CONN_REQ: {
uint16_t rcid;
if (p + 4 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CMD_CONN_REQ");
return;
}
STREAM_TO_UINT16(con_info.psm, p);
STREAM_TO_UINT16(rcid, p);
tL2C_RCB* p_rcb = l2cu_find_rcb_by_psm(con_info.psm);
if (!p_rcb) {
LOG_WARN("Rcvd conn req for unknown PSM: %d", con_info.psm);
l2cu_reject_connection(p_lcb, rcid, id, L2CAP_CONN_NO_PSM);
break;
} else {
if (!p_rcb->api.pL2CA_ConnectInd_Cb) {
LOG_WARN("Rcvd conn req for outgoing-only connection PSM: %d",
con_info.psm);
l2cu_reject_connection(p_lcb, rcid, id, L2CAP_CONN_NO_PSM);
break;
}
}
tL2C_CCB* p_ccb = l2cu_allocate_ccb(p_lcb, 0);
if (p_ccb == nullptr) {
LOG_ERROR("Unable to allocate CCB");
l2cu_reject_connection(p_lcb, rcid, id, L2CAP_CONN_NO_RESOURCES);
break;
}
p_ccb->remote_id = id;
p_ccb->p_rcb = p_rcb;
p_ccb->remote_cid = rcid;
p_ccb->connection_initiator = L2CAP_INITIATOR_REMOTE;
if (p_rcb->psm == BT_PSM_RFCOMM) {
btsnoop_get_interface()->add_rfc_l2c_channel(
p_lcb->Handle(), p_ccb->local_cid, p_ccb->remote_cid);
} else if (p_rcb->log_packets) {
btsnoop_get_interface()->allowlist_l2c_channel(
p_lcb->Handle(), p_ccb->local_cid, p_ccb->remote_cid);
}
l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONNECT_REQ, &con_info);
break;
}
case L2CAP_CMD_CONN_RSP: {
uint16_t lcid;
if (p + 8 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CMD_CONN_REQ");
return;
}
STREAM_TO_UINT16(con_info.remote_cid, p);
STREAM_TO_UINT16(lcid, p);
STREAM_TO_UINT16(con_info.l2cap_result, p);
STREAM_TO_UINT16(con_info.l2cap_status, p);
tL2C_CCB* p_ccb = l2cu_find_ccb_by_cid(p_lcb, lcid);
if (!p_ccb) {
LOG_WARN("no CCB for conn rsp, LCID: %d RCID: %d", lcid,
con_info.remote_cid);
break;
}
if (p_ccb->local_id != id) {
LOG_WARN("con rsp - bad ID. Exp: %d Got: %d", p_ccb->local_id, id);
break;
}
if (con_info.l2cap_result == L2CAP_CONN_OK)
l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONNECT_RSP, &con_info);
else if (con_info.l2cap_result == L2CAP_CONN_PENDING)
l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONNECT_RSP_PND, &con_info);
else
l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONNECT_RSP_NEG, &con_info);
tL2C_RCB* p_rcb = p_ccb->p_rcb;
if (p_rcb->psm == BT_PSM_RFCOMM) {
btsnoop_get_interface()->add_rfc_l2c_channel(
p_lcb->Handle(), p_ccb->local_cid, p_ccb->remote_cid);
} else if (p_rcb->log_packets) {
btsnoop_get_interface()->allowlist_l2c_channel(
p_lcb->Handle(), p_ccb->local_cid, p_ccb->remote_cid);
}
break;
}
case L2CAP_CMD_CONFIG_REQ: {
uint8_t* p_cfg_end = p + cmd_len;
bool cfg_rej = false;
uint16_t cfg_rej_len = 0;
uint16_t lcid;
if (p + 4 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CMD_CONFIG_REQ");
return;
}
STREAM_TO_UINT16(lcid, p);
STREAM_TO_UINT16(cfg_info.flags, p);
uint8_t* p_cfg_start = p;
cfg_info.flush_to_present = cfg_info.mtu_present =
cfg_info.qos_present = cfg_info.fcr_present = cfg_info.fcs_present =
false;
while (p < p_cfg_end) {
uint8_t cfg_code, cfg_len;
if (p + 2 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CMD_CONFIG_REQ sub_event");
return;
}
STREAM_TO_UINT8(cfg_code, p);
STREAM_TO_UINT8(cfg_len, p);
switch (cfg_code & 0x7F) {
case L2CAP_CFG_TYPE_MTU:
cfg_info.mtu_present = true;
if (cfg_len != 2) {
android_errorWriteLog(0x534e4554, "119870451");
return;
}
if (p + cfg_len > p_next_cmd) {
android_errorWriteLog(0x534e4554, "74202041");
return;
}
STREAM_TO_UINT16(cfg_info.mtu, p);
break;
case L2CAP_CFG_TYPE_FLUSH_TOUT:
cfg_info.flush_to_present = true;
if (cfg_len != 2) {
android_errorWriteLog(0x534e4554, "119870451");
return;
}
if (p + cfg_len > p_next_cmd) {
android_errorWriteLog(0x534e4554, "74202041");
return;
}
STREAM_TO_UINT16(cfg_info.flush_to, p);
break;
case L2CAP_CFG_TYPE_QOS:
cfg_info.qos_present = true;
if (cfg_len != 2 + 5 * 4) {
android_errorWriteLog(0x534e4554, "119870451");
return;
}
if (p + cfg_len > p_next_cmd) {
android_errorWriteLog(0x534e4554, "74202041");
return;
}
STREAM_TO_UINT8(cfg_info.qos.qos_flags, p);
STREAM_TO_UINT8(cfg_info.qos.service_type, p);
STREAM_TO_UINT32(cfg_info.qos.token_rate, p);
STREAM_TO_UINT32(cfg_info.qos.token_bucket_size, p);
STREAM_TO_UINT32(cfg_info.qos.peak_bandwidth, p);
STREAM_TO_UINT32(cfg_info.qos.latency, p);
STREAM_TO_UINT32(cfg_info.qos.delay_variation, p);
break;
case L2CAP_CFG_TYPE_FCR:
cfg_info.fcr_present = true;
if (cfg_len != 3 + 3 * 2) {
android_errorWriteLog(0x534e4554, "119870451");
return;
}
if (p + cfg_len > p_next_cmd) {
android_errorWriteLog(0x534e4554, "74202041");
return;
}
STREAM_TO_UINT8(cfg_info.fcr.mode, p);
STREAM_TO_UINT8(cfg_info.fcr.tx_win_sz, p);
STREAM_TO_UINT8(cfg_info.fcr.max_transmit, p);
STREAM_TO_UINT16(cfg_info.fcr.rtrans_tout, p);
STREAM_TO_UINT16(cfg_info.fcr.mon_tout, p);
STREAM_TO_UINT16(cfg_info.fcr.mps, p);
break;
case L2CAP_CFG_TYPE_FCS:
cfg_info.fcs_present = true;
if (cfg_len != 1) {
android_errorWriteLog(0x534e4554, "119870451");
return;
}
if (p + cfg_len > p_next_cmd) {
android_errorWriteLog(0x534e4554, "74202041");
return;
}
STREAM_TO_UINT8(cfg_info.fcs, p);
break;
case L2CAP_CFG_TYPE_EXT_FLOW:
cfg_info.ext_flow_spec_present = true;
if (cfg_len != 2 + 2 + 3 * 4) {
android_errorWriteLog(0x534e4554, "119870451");
return;
}
if (p + cfg_len > p_next_cmd) {
android_errorWriteLog(0x534e4554, "74202041");
return;
}
STREAM_TO_UINT8(cfg_info.ext_flow_spec.id, p);
STREAM_TO_UINT8(cfg_info.ext_flow_spec.stype, p);
STREAM_TO_UINT16(cfg_info.ext_flow_spec.max_sdu_size, p);
STREAM_TO_UINT32(cfg_info.ext_flow_spec.sdu_inter_time, p);
STREAM_TO_UINT32(cfg_info.ext_flow_spec.access_latency, p);
STREAM_TO_UINT32(cfg_info.ext_flow_spec.flush_timeout, p);
break;
default:
/* sanity check option length */
if ((cfg_len + L2CAP_CFG_OPTION_OVERHEAD) <= cmd_len) {
if (p + cfg_len > p_next_cmd) return;
p += cfg_len;
if ((cfg_code & 0x80) == 0) {
cfg_rej_len += cfg_len + L2CAP_CFG_OPTION_OVERHEAD;
cfg_rej = true;
}
}
/* bad length; force loop exit */
else {
p = p_cfg_end;
cfg_rej = true;
}
break;
}
}
tL2C_CCB* p_ccb = l2cu_find_ccb_by_cid(p_lcb, lcid);
if (p_ccb) {
p_ccb->remote_id = id;
if (cfg_rej) {
l2cu_send_peer_config_rej(
p_ccb, p_cfg_start, (uint16_t)(cmd_len - L2CAP_CONFIG_REQ_LEN),
cfg_rej_len);
} else {
l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONFIG_REQ, &cfg_info);
}
} else {
/* updated spec says send command reject on invalid cid */
l2cu_send_peer_cmd_reject(p_lcb, L2CAP_CMD_REJ_INVALID_CID, id, 0, 0);
}
break;
}
case L2CAP_CMD_CONFIG_RSP: {
uint8_t* p_cfg_end = p + cmd_len;
uint16_t lcid;
if (p + 6 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CMD_CONFIG_RSP");
return;
}
STREAM_TO_UINT16(lcid, p);
STREAM_TO_UINT16(cfg_info.flags, p);
STREAM_TO_UINT16(cfg_info.result, p);
cfg_info.flush_to_present = cfg_info.mtu_present =
cfg_info.qos_present = cfg_info.fcr_present = cfg_info.fcs_present =
false;
while (p < p_cfg_end) {
uint8_t cfg_code, cfg_len;
if (p + 2 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CMD_CONFIG_RSP sub_event");
return;
}
STREAM_TO_UINT8(cfg_code, p);
STREAM_TO_UINT8(cfg_len, p);
switch (cfg_code & 0x7F) {
case L2CAP_CFG_TYPE_MTU:
cfg_info.mtu_present = true;
if (p + 2 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CFG_TYPE_MTU");
return;
}
STREAM_TO_UINT16(cfg_info.mtu, p);
break;
case L2CAP_CFG_TYPE_FLUSH_TOUT:
cfg_info.flush_to_present = true;
if (p + 2 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CFG_TYPE_FLUSH_TOUT");
return;
}
STREAM_TO_UINT16(cfg_info.flush_to, p);
break;
case L2CAP_CFG_TYPE_QOS:
cfg_info.qos_present = true;
if (p + 2 + 5 * 4 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CFG_TYPE_QOS");
return;
}
STREAM_TO_UINT8(cfg_info.qos.qos_flags, p);
STREAM_TO_UINT8(cfg_info.qos.service_type, p);
STREAM_TO_UINT32(cfg_info.qos.token_rate, p);
STREAM_TO_UINT32(cfg_info.qos.token_bucket_size, p);
STREAM_TO_UINT32(cfg_info.qos.peak_bandwidth, p);
STREAM_TO_UINT32(cfg_info.qos.latency, p);
STREAM_TO_UINT32(cfg_info.qos.delay_variation, p);
break;
case L2CAP_CFG_TYPE_FCR:
cfg_info.fcr_present = true;
if (p + 3 + 3 * 2 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CFG_TYPE_FCR");
return;
}
STREAM_TO_UINT8(cfg_info.fcr.mode, p);
STREAM_TO_UINT8(cfg_info.fcr.tx_win_sz, p);
STREAM_TO_UINT8(cfg_info.fcr.max_transmit, p);
STREAM_TO_UINT16(cfg_info.fcr.rtrans_tout, p);
STREAM_TO_UINT16(cfg_info.fcr.mon_tout, p);
STREAM_TO_UINT16(cfg_info.fcr.mps, p);
break;
case L2CAP_CFG_TYPE_FCS:
cfg_info.fcs_present = true;
if (p + 1 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CFG_TYPE_FCS");
return;
}
STREAM_TO_UINT8(cfg_info.fcs, p);
break;
case L2CAP_CFG_TYPE_EXT_FLOW:
cfg_info.ext_flow_spec_present = true;
if (p + 2 + 2 + 3 * 4 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CFG_TYPE_EXT_FLOW");
return;
}
STREAM_TO_UINT8(cfg_info.ext_flow_spec.id, p);
STREAM_TO_UINT8(cfg_info.ext_flow_spec.stype, p);
STREAM_TO_UINT16(cfg_info.ext_flow_spec.max_sdu_size, p);
STREAM_TO_UINT32(cfg_info.ext_flow_spec.sdu_inter_time, p);
STREAM_TO_UINT32(cfg_info.ext_flow_spec.access_latency, p);
STREAM_TO_UINT32(cfg_info.ext_flow_spec.flush_timeout, p);
break;
}
}
tL2C_CCB* p_ccb = l2cu_find_ccb_by_cid(p_lcb, lcid);
if (p_ccb) {
if (p_ccb->local_id != id) {
LOG_WARN("cfg rsp - bad ID. Exp: %d Got: %d", p_ccb->local_id, id);
break;
}
if (cfg_info.result == L2CAP_CFG_OK) {
l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONFIG_RSP, &cfg_info);
} else {
l2c_csm_execute(p_ccb, L2CEVT_L2CAP_CONFIG_RSP_NEG, &cfg_info);
}
} else {
LOG_WARN("Rcvd cfg rsp for unknown CID: 0x%04x", lcid);
}
break;
}
case L2CAP_CMD_DISC_REQ: {
uint16_t lcid, rcid;
if (p + 4 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CMD_DISC_REQ");
return;
}
STREAM_TO_UINT16(lcid, p);
STREAM_TO_UINT16(rcid, p);
tL2C_CCB* p_ccb = l2cu_find_ccb_by_cid(p_lcb, lcid);
if (p_ccb) {
if (p_ccb->remote_cid == rcid) {
p_ccb->remote_id = id;
l2c_csm_execute(p_ccb, L2CEVT_L2CAP_DISCONNECT_REQ, &con_info);
}
} else
l2cu_send_peer_disc_rsp(p_lcb, id, lcid, rcid);
break;
}
case L2CAP_CMD_DISC_RSP: {
uint16_t lcid, rcid;
if (p + 4 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CMD_DISC_RSP");
return;
}
STREAM_TO_UINT16(rcid, p);
STREAM_TO_UINT16(lcid, p);
tL2C_CCB* p_ccb = l2cu_find_ccb_by_cid(p_lcb, lcid);
if (p_ccb) {
if ((p_ccb->remote_cid == rcid) && (p_ccb->local_id == id)) {
l2c_csm_execute(p_ccb, L2CEVT_L2CAP_DISCONNECT_RSP, &con_info);
}
}
break;
}
case L2CAP_CMD_ECHO_REQ:
l2cu_send_peer_echo_rsp(p_lcb, id, p, cmd_len);
break;
case L2CAP_CMD_INFO_REQ: {
uint16_t info_type;
if (p + 2 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CMD_INFO_REQ");
return;
}
STREAM_TO_UINT16(info_type, p);
l2cu_send_peer_info_rsp(p_lcb, id, info_type);
break;
}
case L2CAP_CMD_INFO_RSP:
/* Stop the link connect timer if sent before L2CAP connection is up */
if (p_lcb->w4_info_rsp) {
alarm_cancel(p_lcb->info_resp_timer);
p_lcb->w4_info_rsp = false;
}
uint16_t info_type, result;
if (p + 4 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CMD_INFO_RSP");
return;
}
STREAM_TO_UINT16(info_type, p);
STREAM_TO_UINT16(result, p);
if ((info_type == L2CAP_EXTENDED_FEATURES_INFO_TYPE) &&
(result == L2CAP_INFO_RESP_RESULT_SUCCESS)) {
if (p + 4 > p_next_cmd) {
LOG_WARN("Not enough data for L2CAP_CMD_INFO_RSP sub_event");
return;
}
STREAM_TO_UINT32(p_lcb->peer_ext_fea, p);
if (p_lcb->peer_ext_fea & L2CAP_EXTFEA_FIXED_CHNLS) {
l2cu_send_peer_info_req(p_lcb, L2CAP_FIXED_CHANNELS_INFO_TYPE);
break;
} else {
l2cu_process_fixed_chnl_resp(p_lcb);
}
}
if (info_type == L2CAP_FIXED_CHANNELS_INFO_TYPE) {
if (result == L2CAP_INFO_RESP_RESULT_SUCCESS) {
if (p + L2CAP_FIXED_CHNL_ARRAY_SIZE > p_next_cmd) {
android_errorWriteLog(0x534e4554, "111215173");
return;
}
memcpy(p_lcb->peer_chnl_mask, p, L2CAP_FIXED_CHNL_ARRAY_SIZE);
}
l2cu_process_fixed_chnl_resp(p_lcb);
}
{
tL2C_CONN_INFO ci;
ci.status = HCI_SUCCESS;
ci.bd_addr = p_lcb->remote_bd_addr;
for (tL2C_CCB* p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb;
p_ccb = p_ccb->p_next_ccb) {
l2c_csm_execute(p_ccb, L2CEVT_L2CAP_INFO_RSP, &ci);
}
}
break;
default:
LOG_WARN("Bad cmd code: %d", cmd_code);
l2cu_send_peer_cmd_reject(p_lcb, L2CAP_CMD_REJ_NOT_UNDERSTOOD, id, 0,
0);
return;
}
}
}
/*******************************************************************************
*
* Function l2c_process_held_packets
*
* Description This function processes any L2CAP packets that arrived
* before the HCI connection complete arrived. It is a work
* around for badly behaved controllers.
*
* Returns void
*
******************************************************************************/
void l2c_process_held_packets(bool timed_out) {
if (list_is_empty(l2cb.rcv_pending_q)) return;
if (!timed_out) {
alarm_cancel(l2cb.receive_hold_timer);
L2CAP_TRACE_WARNING("L2CAP HOLD CONTINUE");
} else {
L2CAP_TRACE_WARNING("L2CAP HOLD TIMEOUT");
}
for (const list_node_t* node = list_begin(l2cb.rcv_pending_q);
node != list_end(l2cb.rcv_pending_q);) {
BT_HDR* p_buf = static_cast<BT_HDR*>(list_node(node));
node = list_next(node);
if (!timed_out || (!p_buf->layer_specific) ||
(--p_buf->layer_specific == 0)) {
list_remove(l2cb.rcv_pending_q, p_buf);
p_buf->layer_specific = 0xFFFF;
l2c_rcv_acl_data(p_buf);
}
}
/* If anyone still in the queue, restart the timeout */
if (!list_is_empty(l2cb.rcv_pending_q)) {
alarm_set_on_mloop(l2cb.receive_hold_timer, BT_1SEC_TIMEOUT_MS,
l2c_receive_hold_timer_timeout, NULL);
}
}
/*******************************************************************************
*
* Function l2c_init
*
* Description This function is called once at startup to initialize
* all the L2CAP structures
*
* Returns void
*
******************************************************************************/
void l2c_init(void) {
if (bluetooth::shim::is_gd_l2cap_enabled()) {
// L2CAP init should be handled by GD stack manager
return;
}
int16_t xx;
memset(&l2cb, 0, sizeof(tL2C_CB));
/* the LE PSM is increased by 1 before being used */
l2cb.le_dyn_psm = LE_DYNAMIC_PSM_START - 1;
/* Put all the channel control blocks on the free queue */
for (xx = 0; xx < MAX_L2CAP_CHANNELS - 1; xx++) {
l2cb.ccb_pool[xx].p_next_ccb = &l2cb.ccb_pool[xx + 1];
}
/* it will be set to L2CAP_PKT_START_NON_FLUSHABLE if controller supports */
l2cb.non_flushable_pbf = L2CAP_PKT_START << L2CAP_PKT_TYPE_SHIFT;
l2cb.p_free_ccb_first = &l2cb.ccb_pool[0];
l2cb.p_free_ccb_last = &l2cb.ccb_pool[MAX_L2CAP_CHANNELS - 1];
/* Set the default idle timeout */
l2cb.idle_timeout = L2CAP_LINK_INACTIVITY_TOUT;
#if defined(L2CAP_INITIAL_TRACE_LEVEL)
l2cb.l2cap_trace_level = L2CAP_INITIAL_TRACE_LEVEL;
#else
l2cb.l2cap_trace_level = BT_TRACE_LEVEL_NONE; /* No traces */
#endif
#if (L2CAP_CONFORMANCE_TESTING == TRUE)
/* Conformance testing needs a dynamic response */
l2cb.test_info_resp = L2CAP_EXTFEA_SUPPORTED_MASK;
#endif
/* Number of ACL buffers to use for high priority channel */
l2cb.l2c_ble_fixed_chnls_mask = L2CAP_FIXED_CHNL_ATT_BIT |
L2CAP_FIXED_CHNL_BLE_SIG_BIT |
L2CAP_FIXED_CHNL_SMP_BIT;
l2cb.rcv_pending_q = list_new(NULL);
CHECK(l2cb.rcv_pending_q != NULL);
l2cb.receive_hold_timer = alarm_new("l2c.receive_hold_timer");
}
void l2c_free(void) {
if (bluetooth::shim::is_gd_l2cap_enabled()) {
// L2CAP cleanup should be handled by GD stack manager
return;
}
list_free(l2cb.rcv_pending_q);
l2cb.rcv_pending_q = NULL;
}
void l2c_receive_hold_timer_timeout(UNUSED_ATTR void* data) {
/* Update the timeouts in the hold queue */
l2c_process_held_packets(true);
}
void l2c_ccb_timer_timeout(void* data) {
tL2C_CCB* p_ccb = (tL2C_CCB*)data;
l2c_csm_execute(p_ccb, L2CEVT_TIMEOUT, NULL);
}
void l2c_fcrb_ack_timer_timeout(void* data) {
tL2C_CCB* p_ccb = (tL2C_CCB*)data;
l2c_csm_execute(p_ccb, L2CEVT_ACK_TIMEOUT, NULL);
}
void l2c_lcb_timer_timeout(void* data) {
tL2C_LCB* p_lcb = (tL2C_LCB*)data;
l2c_link_timeout(p_lcb);
}
/*******************************************************************************
*
* Function l2c_data_write
*
* Description API functions call this function to write data.
*
* Returns L2CAP_DW_SUCCESS, if data accepted, else false
* L2CAP_DW_CONGESTED, if data accepted and the channel is
* congested
* L2CAP_DW_FAILED, if error
*
******************************************************************************/
uint8_t l2c_data_write(uint16_t cid, BT_HDR* p_data, uint16_t flags) {
/* Find the channel control block. We don't know the link it is on. */
tL2C_CCB* p_ccb = l2cu_find_ccb_by_cid(NULL, cid);
if (!p_ccb) {
L2CAP_TRACE_WARNING("L2CAP - no CCB for L2CA_DataWrite, CID: %d", cid);
osi_free(p_data);
return (L2CAP_DW_FAILED);
}
/* Sending message bigger than mtu size of peer is a violation of protocol */
uint16_t mtu;
if (p_ccb->p_lcb->transport == BT_TRANSPORT_LE)
mtu = p_ccb->peer_conn_cfg.mtu;
else
mtu = p_ccb->peer_cfg.mtu;
if (p_data->len > mtu) {
L2CAP_TRACE_WARNING(
"L2CAP - CID: 0x%04x cannot send message bigger than peer's mtu size: "
"len=%u mtu=%u",
cid, p_data->len, mtu);
osi_free(p_data);
return (L2CAP_DW_FAILED);
}
/* channel based, packet based flushable or non-flushable */
p_data->layer_specific = flags;
/* If already congested, do not accept any more packets */
if (p_ccb->cong_sent) {
L2CAP_TRACE_ERROR(
"L2CAP - CID: 0x%04x cannot send, already congested "
"xmit_hold_q.count: %u buff_quota: %u",
p_ccb->local_cid, fixed_queue_length(p_ccb->xmit_hold_q),
p_ccb->buff_quota);
osi_free(p_data);
return (L2CAP_DW_FAILED);
}
l2c_csm_execute(p_ccb, L2CEVT_L2CA_DATA_WRITE, p_data);
if (p_ccb->cong_sent) return (L2CAP_DW_CONGESTED);
return (L2CAP_DW_SUCCESS);
}