1 // 2 // Copyright 2017 The Android Open Source Project 3 // 4 // Licensed under the Apache License, Version 2.0 (the "License"); 5 // you may not use this file except in compliance with the License. 6 // You may obtain a copy of the License at 7 // 8 // http://www.apache.org/licenses/LICENSE-2.0 9 // 10 // Unless required by applicable law or agreed to in writing, software 11 // distributed under the License is distributed on an "AS IS" BASIS, 12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 // See the License for the specific language governing permissions and 14 // limitations under the License. 15 // 16 17 #include "hci_packetizer.h" 18 19 #define LOG_TAG "android.hardware.bluetooth.hci_packetizer" 20 21 #include <dlfcn.h> 22 #include <errno.h> 23 #include <fcntl.h> 24 #include <unistd.h> 25 #include <utils/Log.h> 26 27 namespace { 28 29 const size_t preamble_size_for_type[] = { 30 0, HCI_COMMAND_PREAMBLE_SIZE, HCI_ACL_PREAMBLE_SIZE, HCI_SCO_PREAMBLE_SIZE, 31 HCI_EVENT_PREAMBLE_SIZE}; 32 const size_t packet_length_offset_for_type[] = { 33 0, HCI_LENGTH_OFFSET_CMD, HCI_LENGTH_OFFSET_ACL, HCI_LENGTH_OFFSET_SCO, 34 HCI_LENGTH_OFFSET_EVT}; 35 36 size_t HciGetPacketLengthForType(HciPacketType type, const uint8_t* preamble) { 37 size_t offset = packet_length_offset_for_type[type]; 38 if (type != HCI_PACKET_TYPE_ACL_DATA) return preamble[offset]; 39 return (((preamble[offset + 1]) << 8) | preamble[offset]); 40 } 41 42 } // namespace 43 44 namespace android { 45 namespace hardware { 46 namespace bluetooth { 47 namespace hci { 48 49 const hidl_vec<uint8_t>& HciPacketizer::GetPacket() const { return packet_; } 50 51 void HciPacketizer::OnDataReady(int fd, HciPacketType packet_type) { 52 switch (state_) { 53 case HCI_PREAMBLE: { 54 ssize_t bytes_read = TEMP_FAILURE_RETRY( 55 read(fd, preamble_ + bytes_read_, 56 preamble_size_for_type[packet_type] - bytes_read_)); 57 if (bytes_read == 0) { 58 // This is only expected if the UART got closed when shutting down. 59 ALOGE("%s: Unexpected EOF reading the header!", __func__); 60 sleep(5); // Expect to be shut down within 5 seconds. 61 return; 62 } 63 if (bytes_read < 0) { 64 LOG_ALWAYS_FATAL("%s: Read header error: %s", __func__, 65 strerror(errno)); 66 } 67 bytes_read_ += bytes_read; 68 if (bytes_read_ == preamble_size_for_type[packet_type]) { 69 size_t packet_length = 70 HciGetPacketLengthForType(packet_type, preamble_); 71 packet_.resize(preamble_size_for_type[packet_type] + packet_length); 72 memcpy(packet_.data(), preamble_, preamble_size_for_type[packet_type]); 73 bytes_remaining_ = packet_length; 74 state_ = HCI_PAYLOAD; 75 bytes_read_ = 0; 76 } 77 break; 78 } 79 80 case HCI_PAYLOAD: { 81 ssize_t bytes_read = TEMP_FAILURE_RETRY(read( 82 fd, 83 packet_.data() + preamble_size_for_type[packet_type] + bytes_read_, 84 bytes_remaining_)); 85 if (bytes_read == 0) { 86 // This is only expected if the UART got closed when shutting down. 87 ALOGE("%s: Unexpected EOF reading the payload!", __func__); 88 sleep(5); // Expect to be shut down within 5 seconds. 89 return; 90 } 91 if (bytes_read < 0) { 92 LOG_ALWAYS_FATAL("%s: Read payload error: %s", __func__, 93 strerror(errno)); 94 } 95 bytes_remaining_ -= bytes_read; 96 bytes_read_ += bytes_read; 97 if (bytes_remaining_ == 0) { 98 packet_ready_cb_(); 99 state_ = HCI_PREAMBLE; 100 bytes_read_ = 0; 101 } 102 break; 103 } 104 } 105 } 106 107 } // namespace hci 108 } // namespace bluetooth 109 } // namespace hardware 110 } // namespace android 111
