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//
// Copyright 2017 The Android Open Source Project
//
// 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.
//
#include "hci_packetizer.h"
#define LOG_TAG "android.hardware.bluetooth.hci_packetizer"
#include <android-base/logging.h>
#include <utils/Log.h>
#include <dlfcn.h>
#include <fcntl.h>
namespace {
const size_t preamble_size_for_type[] = {
0, HCI_COMMAND_PREAMBLE_SIZE, HCI_ACL_PREAMBLE_SIZE, HCI_SCO_PREAMBLE_SIZE,
HCI_EVENT_PREAMBLE_SIZE};
const size_t packet_length_offset_for_type[] = {
0, HCI_LENGTH_OFFSET_CMD, HCI_LENGTH_OFFSET_ACL, HCI_LENGTH_OFFSET_SCO,
HCI_LENGTH_OFFSET_EVT};
size_t HciGetPacketLengthForType(HciPacketType type, const uint8_t* preamble) {
size_t offset = packet_length_offset_for_type[type];
if (type != HCI_PACKET_TYPE_ACL_DATA) return preamble[offset];
return (((preamble[offset + 1]) << 8) | preamble[offset]);
}
} // namespace
namespace android {
namespace hardware {
namespace bluetooth {
namespace hci {
const hidl_vec<uint8_t>& HciPacketizer::GetPacket() const { return packet_; }
void HciPacketizer::OnDataReady(int fd, HciPacketType packet_type) {
switch (state_) {
case HCI_PREAMBLE: {
size_t bytes_read = TEMP_FAILURE_RETRY(
read(fd, preamble_ + bytes_read_,
preamble_size_for_type[packet_type] - bytes_read_));
CHECK(bytes_read > 0);
bytes_read_ += bytes_read;
if (bytes_read_ == preamble_size_for_type[packet_type]) {
size_t packet_length =
HciGetPacketLengthForType(packet_type, preamble_);
packet_.resize(preamble_size_for_type[packet_type] + packet_length);
memcpy(packet_.data(), preamble_, preamble_size_for_type[packet_type]);
bytes_remaining_ = packet_length;
state_ = HCI_PAYLOAD;
bytes_read_ = 0;
}
break;
}
case HCI_PAYLOAD: {
size_t bytes_read = TEMP_FAILURE_RETRY(read(
fd,
packet_.data() + preamble_size_for_type[packet_type] + bytes_read_,
bytes_remaining_));
CHECK(bytes_read > 0);
bytes_remaining_ -= bytes_read;
bytes_read_ += bytes_read;
if (bytes_remaining_ == 0) {
packet_ready_cb_();
state_ = HCI_PREAMBLE;
bytes_read_ = 0;
}
break;
}
}
}
} // namespace hci
} // namespace bluetooth
} // namespace hardware
} // namespace android
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