1 /*
2 * Copyright 2021 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_sniffer.h"
18
19 #include "hci/pcap_filter.h"
20 #include "pcap.h"
21
22 namespace rootcanal {
23
HciSniffer(std::shared_ptr<HciTransport> transport,std::shared_ptr<std::ostream> outputStream,std::shared_ptr<PcapFilter> filter)24 HciSniffer::HciSniffer(std::shared_ptr<HciTransport> transport,
25 std::shared_ptr<std::ostream> outputStream,
26 std::shared_ptr<PcapFilter> filter)
27 : transport_(transport), filter_(filter) {
28 SetOutputStream(outputStream);
29 }
30
SetPcapFilter(std::shared_ptr<PcapFilter> filter)31 void HciSniffer::SetPcapFilter(std::shared_ptr<PcapFilter> filter) {
32 filter_ = filter;
33 }
34
SetOutputStream(std::shared_ptr<std::ostream> outputStream)35 void HciSniffer::SetOutputStream(std::shared_ptr<std::ostream> outputStream) {
36 output_ = outputStream;
37 if (output_) {
38 uint32_t linktype = 201; // http://www.tcpdump.org/linktypes.html
39 // LINKTYPE_BLUETOOTH_HCI_H4_WITH_PHDR
40
41 pcap::WriteHeader(*output_, linktype);
42 }
43 }
44
AppendRecord(PacketDirection packet_direction,PacketType packet_type,const std::vector<uint8_t> & packet)45 void HciSniffer::AppendRecord(PacketDirection packet_direction,
46 PacketType packet_type,
47 const std::vector<uint8_t>& packet) {
48 if (output_ == nullptr) {
49 return;
50 }
51
52 pcap::WriteRecordHeader(*output_, 4 + 1 + packet.size());
53
54 // http://www.tcpdump.org/linktypes.html LINKTYPE_BLUETOOTH_HCI_H4_WITH_PHDR
55 // Note: the description given for the direction bit by tcpdump
56 // is in opposition with the implementation in wireshark.
57 // The values match wireshark's implementation here.
58 char direction[4] = {0, 0, 0, static_cast<char>(packet_direction)};
59 uint8_t idc = static_cast<uint8_t>(packet_type);
60 output_->write(direction, sizeof(direction));
61 output_->write((char*)&idc, 1);
62
63 // Apply the PCAP filter when provided.
64 if (filter_ != nullptr) {
65 std::vector<uint8_t> filtered_packet =
66 filter_->FilterHciPacket(packet, idc);
67 output_->write((char*)filtered_packet.data(), filtered_packet.size());
68 } else {
69 output_->write((char*)packet.data(), packet.size());
70 }
71
72 // Flush packet.
73 output_->flush();
74 }
75
RegisterCallbacks(PacketCallback command_callback,PacketCallback acl_callback,PacketCallback sco_callback,PacketCallback iso_callback,CloseCallback close_callback)76 void HciSniffer::RegisterCallbacks(PacketCallback command_callback,
77 PacketCallback acl_callback,
78 PacketCallback sco_callback,
79 PacketCallback iso_callback,
80 CloseCallback close_callback) {
81 transport_->RegisterCallbacks(
82 [this,
83 command_callback](const std::shared_ptr<std::vector<uint8_t>> command) {
84 AppendRecord(PacketDirection::HOST_TO_CONTROLLER, PacketType::COMMAND,
85 *command);
86 command_callback(command);
87 },
88 [this, acl_callback](const std::shared_ptr<std::vector<uint8_t>> acl) {
89 AppendRecord(PacketDirection::HOST_TO_CONTROLLER, PacketType::ACL,
90 *acl);
91 acl_callback(acl);
92 },
93 [this, sco_callback](const std::shared_ptr<std::vector<uint8_t>> sco) {
94 AppendRecord(PacketDirection::HOST_TO_CONTROLLER, PacketType::SCO,
95 *sco);
96 sco_callback(sco);
97 },
98 [this, iso_callback](const std::shared_ptr<std::vector<uint8_t>> iso) {
99 AppendRecord(PacketDirection::HOST_TO_CONTROLLER, PacketType::ISO,
100 *iso);
101 iso_callback(iso);
102 },
103 close_callback);
104 }
105
Tick()106 void HciSniffer::Tick() { transport_->Tick(); }
107
Close()108 void HciSniffer::Close() {
109 transport_->Close();
110 if (output_ != nullptr) {
111 output_->flush();
112 }
113 }
114
SendEvent(const std::vector<uint8_t> & packet)115 void HciSniffer::SendEvent(const std::vector<uint8_t>& packet) {
116 AppendRecord(PacketDirection::CONTROLLER_TO_HOST, PacketType::EVENT, packet);
117 transport_->SendEvent(packet);
118 }
119
SendAcl(const std::vector<uint8_t> & packet)120 void HciSniffer::SendAcl(const std::vector<uint8_t>& packet) {
121 AppendRecord(PacketDirection::CONTROLLER_TO_HOST, PacketType::ACL, packet);
122 transport_->SendAcl(packet);
123 }
124
SendSco(const std::vector<uint8_t> & packet)125 void HciSniffer::SendSco(const std::vector<uint8_t>& packet) {
126 AppendRecord(PacketDirection::CONTROLLER_TO_HOST, PacketType::SCO, packet);
127 transport_->SendSco(packet);
128 }
129
SendIso(const std::vector<uint8_t> & packet)130 void HciSniffer::SendIso(const std::vector<uint8_t>& packet) {
131 AppendRecord(PacketDirection::CONTROLLER_TO_HOST, PacketType::ISO, packet);
132 transport_->SendIso(packet);
133 }
134 } // namespace rootcanal
135