Merge "RootCanal: Extract pcap writing logic outside hci_sniffer" (62f86912) · Commits · e / os / android_packages_modules_Bluetooth

tools/rootcanal/include/pcap.h

0 → 100644

+61 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright 2022 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.
		*/

		#pragma once

		#include <chrono>
		#include <cstdint>
		#include <limits>
		#include <ostream>

		namespace rootcanal::pcap {

		using namespace std::literals;

		static void WriteHeader(std::ostream& output, uint32_t linktype) {
		// https://tools.ietf.org/id/draft-gharris-opsawg-pcap-00.html#name-file-header
		uint32_t magic_number = 0xa1b2c3d4;
		uint16_t major_version = 2;
		uint16_t minor_version = 4;
		uint32_t reserved1 = 0;
		uint32_t reserved2 = 0;
		uint32_t snaplen = std::numeric_limits<uint32_t>::max();

		output.write((char*)&magic_number, 4);
		output.write((char*)&major_version, 2);
		output.write((char*)&minor_version, 2);
		output.write((char*)&reserved1, 4);
		output.write((char*)&reserved2, 4);
		output.write((char*)&snaplen, 4);
		output.write((char*)&linktype, 4);
		}

		static void WriteRecordHeader(std::ostream& output, uint32_t length) {
		auto time = std::chrono::system_clock::now().time_since_epoch();

		// https://tools.ietf.org/id/draft-gharris-opsawg-pcap-00.html#name-packet-record
		uint32_t seconds = time / 1s;
		uint32_t microseconds = (time % 1s) / 1ms;
		uint32_t captured_packet_length = length;
		uint32_t original_packet_length = length;

		output.write((char*)&seconds, 4);
		output.write((char*)&microseconds, 4);
		output.write((char*)&captured_packet_length, 4);
		output.write((char*)&original_packet_length, 4);
		}

		} // namespace rootcanal::pcap

tools/rootcanal/model/hci/hci_sniffer.cc

+7 −37

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		@@ -16,65 +16,35 @@

		#include "hci_sniffer.h"

		#include <chrono>
		#include <limits>

		using namespace std::literals;
		#include "pcap.h"

		namespace rootcanal {

		static void writeHeader(std::ostream* stream) {
		// https://tools.ietf.org/id/draft-gharris-opsawg-pcap-00.xml#file-header
		uint32_t magic_number = 0xa1b2c3d4;
		uint16_t major_version = 2;
		uint16_t minor_version = 4;
		uint32_t reserved1 = 0;
		uint32_t reserved2 = 0;
		uint32_t snaplen = std::numeric_limits<uint32_t>::max();
		uint32_t linktype = 201; // http://www.tcpdump.org/linktypes.html
		// LINKTYPE_BLUETOOTH_HCI_H4_WITH_PHDR

		stream->write((char*)&magic_number, 4);
		stream->write((char*)&major_version, 2);
		stream->write((char*)&minor_version, 2);
		stream->write((char*)&reserved1, 4);
		stream->write((char*)&reserved2, 4);
		stream->write((char*)&snaplen, 4);
		stream->write((char*)&linktype, 4);
		}

		HciSniffer::HciSniffer(std::shared_ptr<HciTransport> transport,
		std::shared_ptr<std::ostream> outputStream)
		: transport_(transport), start_(std::chrono::steady_clock::now()) {
		: transport_(transport) {
		SetOutputStream(outputStream);
		}

		void HciSniffer::SetOutputStream(std::shared_ptr<std::ostream> outputStream) {
		output_ = outputStream;
		if (output_) {
		writeHeader(output_.get());
		uint32_t linktype = 201; // http://www.tcpdump.org/linktypes.html
		// LINKTYPE_BLUETOOTH_HCI_H4_WITH_PHDR

		pcap::WriteHeader(*output_, linktype);
		}
		}

		void HciSniffer::AppendRecord(PacketDirection packet_direction,
		PacketType packet_type,
		const std::vector<uint8_t>& packet) {
		auto time = std::chrono::steady_clock::now() - start_;

		// https://tools.ietf.org/id/draft-gharris-opsawg-pcap-00.xml#rfc.section.5
		uint32_t seconds = time / 1s;
		uint32_t microseconds = (time % 1s) / 1ms;
		uint32_t captured_packet_length = 4 + 1 + packet.size();
		uint32_t original_packet_length = captured_packet_length;
		pcap::WriteRecordHeader(*output_, 4 + 1 + packet.size());

		// http://www.tcpdump.org/linktypes.html LINKTYPE_BLUETOOTH_HCI_H4_WITH_PHDR
		uint32_t direction = static_cast<uint32_t>(packet_direction);
		uint8_t idc = static_cast<uint8_t>(packet_type);

		output_->write((char*)&seconds, 4);
		output_->write((char*)&microseconds, 4);
		output_->write((char*)&captured_packet_length, 4);
		output_->write((char*)&original_packet_length, 4);
		output_->write((char*)&direction, 4);
		output_->write((char*)&idc, 1);
		output_->write((char*)packet.data(), packet.size());

tools/rootcanal/model/hci/hci_sniffer.h

+0 −2

Original line number	Diff line number	Diff line
		@@ -16,7 +16,6 @@

		#pragma once

		#include <chrono>
		#include <cstdint>
		#include <fstream>
		#include <memory>
		@@ -73,7 +72,6 @@ class HciSniffer : public HciTransport {

		std::shared_ptr<std::ostream> output_;
		std::shared_ptr<HciTransport> transport_;
		std::chrono::time_point<std::chrono::steady_clock> start_;
		};

		} // namespace rootcanal