Bluetooth: Make HciPacketizer reusable

Test: VtsHalBluetoothV1_0TargetTest passes
Change-Id: I480d156225af2a5dd879f47a897af0b01dab5663
diff --git a/bluetooth/1.0/default/hci_packetizer.cc b/bluetooth/1.0/default/hci_packetizer.cc
new file mode 100644
index 0000000..1a50196
--- /dev/null
+++ b/bluetooth/1.0/default/hci_packetizer.cc
@@ -0,0 +1,115 @@
+//
+// 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 <cutils/properties.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 {
+
+HciPacketType HciPacketizer::GetPacketType() const {
+  return hci_packet_type_;
+}
+
+const hidl_vec<uint8_t>& HciPacketizer::GetPacket() const {
+  return hci_packet_;
+}
+
+void HciPacketizer::OnDataReady(int fd) {
+  switch (hci_parser_state_) {
+    case HCI_IDLE: {
+      uint8_t buffer[1] = {0};
+      size_t bytes_read = TEMP_FAILURE_RETRY(read(fd, buffer, 1));
+      CHECK(bytes_read == 1);
+      hci_packet_type_ = static_cast<HciPacketType>(buffer[0]);
+      CHECK(hci_packet_type_ >= HCI_PACKET_TYPE_ACL_DATA &&
+            hci_packet_type_ <= HCI_PACKET_TYPE_EVENT)
+          << "buffer[0] = " << static_cast<unsigned int>(buffer[0]);
+      hci_parser_state_ = HCI_TYPE_READY;
+      hci_packet_bytes_remaining_ = preamble_size_for_type[hci_packet_type_];
+      hci_packet_bytes_read_ = 0;
+      break;
+    }
+
+    case HCI_TYPE_READY: {
+      size_t bytes_read = TEMP_FAILURE_RETRY(
+          read(fd, hci_packet_preamble_ + hci_packet_bytes_read_,
+               hci_packet_bytes_remaining_));
+      CHECK(bytes_read > 0);
+      hci_packet_bytes_remaining_ -= bytes_read;
+      hci_packet_bytes_read_ += bytes_read;
+      if (hci_packet_bytes_remaining_ == 0) {
+        size_t packet_length =
+            HciGetPacketLengthForType(hci_packet_type_, hci_packet_preamble_);
+        hci_packet_.resize(preamble_size_for_type[hci_packet_type_] +
+                           packet_length);
+        memcpy(hci_packet_.data(), hci_packet_preamble_,
+               preamble_size_for_type[hci_packet_type_]);
+        hci_packet_bytes_remaining_ = packet_length;
+        hci_parser_state_ = HCI_PAYLOAD;
+        hci_packet_bytes_read_ = 0;
+      }
+      break;
+    }
+
+    case HCI_PAYLOAD: {
+      size_t bytes_read = TEMP_FAILURE_RETRY(
+          read(fd,
+               hci_packet_.data() + preamble_size_for_type[hci_packet_type_] +
+                   hci_packet_bytes_read_,
+               hci_packet_bytes_remaining_));
+      CHECK(bytes_read > 0);
+      hci_packet_bytes_remaining_ -= bytes_read;
+      hci_packet_bytes_read_ += bytes_read;
+      if (hci_packet_bytes_remaining_ == 0) {
+        hci_packet_ready_cb_();
+        hci_parser_state_ = HCI_IDLE;
+      }
+      break;
+    }
+  }
+}
+
+}  // namespace hci
+}  // namespace bluetooth
+}  // namespace hardware
+}  // namespace android