Fix: fragment packets (5fd6aecc) · Commits · e / os / android_packages_modules_Bluetooth

TEST_MAPPING

+4 −0

Original line number	Diff line number	Diff line
		@@ -84,6 +84,10 @@
		{
		"name" : "net_test_stack_gatt_native",
		"host" : true
		},
		{
		"name" : "net_test_hci_fragmenter_native",
		"host" : true
		}
		]
		}

system/hci/Android.bp

+37 −0

Original line number	Diff line number	Diff line
		@@ -112,3 +112,40 @@ cc_test {
		misc_undefined: ["bounds"],
		},
		}

		cc_test {
		name: "net_test_hci_fragmenter_native",
		test_suites: ["device-tests"],
		defaults: ["fluoride_defaults"],
		host_supported: true,
		local_include_dirs: [
		"include",
		],
		include_dirs: [
		"packages/modules/Bluetooth/system",
		"packages/modules/Bluetooth/system/stack/include",
		"packages/modules/Bluetooth/system/btcore/include",
		"packages/modules/Bluetooth/system/osi/test",
		],
		srcs: [
		"src/buffer_allocator.cc",
		"test/packet_fragmenter_host_test.cc",
		],
		shared_libs: [
		"libcrypto",
		"liblog",
		"libprotobuf-cpp-lite",
		],
		static_libs: [
		"libbt-common",
		"libbt-protos-lite",
		"libosi",
		"libosi-AllocationTestHarness",
		],
		sanitize: {
		address: true,
		cfi: true,
		misc_undefined: ["bounds"],
		},
		}

system/hci/src/packet_fragmenter.cc

+3 −3

Original line number	Diff line number	Diff line
		@@ -119,7 +119,7 @@ static bool check_uint16_overflow(uint16_t a, uint16_t b) {
		return (UINT16_MAX - a) < b;
		}

		static void reassemble_and_dispatch(UNUSED_ATTR BT_HDR* packet) {
		static void reassemble_and_dispatch(BT_HDR* packet) {
		if ((packet->event & MSG_EVT_MASK) == MSG_HC_TO_STACK_HCI_ACL) {
		uint8_t* stream = packet->data;
		uint16_t handle;
		@@ -213,8 +213,8 @@ static void reassemble_and_dispatch(UNUSED_ATTR BT_HDR* packet) {
		packet->offset = HCI_ACL_PREAMBLE_SIZE;
		uint16_t projected_offset =
		partial_packet->offset + (packet->len - HCI_ACL_PREAMBLE_SIZE);
		if (projected_offset >
		partial_packet->len) { // len stores the expected length
		if ((packet->len - packet->offset) >
		(partial_packet->len - partial_packet->offset)) {
		LOG_WARN(
		"%s got packet which would exceed expected length of %d. "
		"Truncating.",

system/hci/test/packet_fragmenter_host_test.cc

0 → 100644

+421 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright 2020 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 <base/logging.h>
		#include <gtest/gtest.h>
		#include <cstdint>
		#include <queue>

		#include "hci/src/packet_fragmenter.cc"
		#include "osi/test/AllocationTestHarness.h"

		extern void allocation_tracker_uninit(void);

		enum kPacketOrder {
		kStart = 1,
		kContinuation = 2,
		};

		struct AclPacketHeader {
		struct {
		uint16_t handle : 12;
		uint16_t continuation : 1;
		uint16_t start : 1;
		uint16_t reserved : 2;
		} s;
		uint16_t length;

		uint16_t GetRawHandle() const { return (uint16_t)(this); }

		uint16_t GetHandle() const { return s.handle; }
		uint16_t GetLength() const { return length; }
		} __attribute__((packed));

		struct L2capPacketHeader {
		uint16_t length;
		uint16_t cid;
		} __attribute__((packed));

		struct AclL2capPacketHeader {
		struct AclPacketHeader acl_header;
		struct L2capPacketHeader l2cap_header;
		} __attribute__((packed));

		namespace {

		constexpr uint16_t kHandle = 0x123;
		constexpr uint16_t kCid = 0x4567;
		constexpr uint16_t kMaxPacketSize = BT_DEFAULT_BUFFER_SIZE - sizeof(BT_HDR) -
		L2CAP_HEADER_SIZE - HCI_ACL_PREAMBLE_SIZE;
		constexpr size_t kTypicalPacketSizes[] = {
		1, 2, 3, 4, 8, 16, 32, 64, 127, 128, 129, 256, 1024, 2048, kMaxPacketSize};
		constexpr size_t kNumberOfTypicalPacketSizes =
		sizeof(kTypicalPacketSizes) / sizeof(kTypicalPacketSizes[0]);

		void FreeBuffer(BT_HDR* bt_hdr) { osi_free(bt_hdr); }

		struct TestMutables {
		struct {
		int access_count_{0};
		} fragmented;
		struct {
		int access_count_{0};
		std::queue<std::unique_ptr<BT_HDR, decltype(&FreeBuffer)>> queue;
		} reassembled;
		struct {
		int access_count_{0};
		} transmit_finished;
		};

		TestMutables test_state_;

		void OnFragmented(BT_HDR* packet, bool send_transmit_finished) {
		test_state_.fragmented.access_count_++;
		}

		void OnReassembled(BT_HDR* packet) {
		test_state_.reassembled.access_count_++;
		test_state_.reassembled.queue.push(
		std::unique_ptr<BT_HDR, decltype(&FreeBuffer)>(packet, &FreeBuffer));
		}

		void OnTransmitFinished(BT_HDR* packet, bool all_fragments_sent) {
		test_state_.transmit_finished.access_count_++;
		}

		packet_fragmenter_callbacks_t result_callbacks = {
		.fragmented = OnFragmented,
		.reassembled = OnReassembled,
		.transmit_finished = OnTransmitFinished,
		};

		AclPacketHeader* AclHeader(BT_HDR* packet) {
		return (AclPacketHeader*)packet->data;
		}
		L2capPacketHeader* L2capHeader(BT_HDR* packet) {
		return &((AclL2capPacketHeader*)packet->data)->l2cap_header;
		}

		uint8_t* Data(BT_HDR* packet) {
		AclPacketHeader* acl_header =
		reinterpret_cast<AclPacketHeader*>(packet->data);
		return acl_header->s.start
		? (uint8_t*)(packet->data + sizeof(AclL2capPacketHeader))
		: (uint8_t*)(packet->data + sizeof(AclPacketHeader));
		}

		} // namespace

		// Needed for linkage
		const controller_t* controller_get_interface() { return nullptr; }

		/**
		* Test class to test selected functionality in hci/src/hci_layer.cc
		*/
		class HciPacketFragmenterTest : public AllocationTestHarness {
		protected:
		void SetUp() override {
		AllocationTestHarness::SetUp();
		// Disable our allocation tracker to allow ASAN full range
		allocation_tracker_uninit();
		packet_fragmenter_ = packet_fragmenter_get_interface();
		packet_fragmenter_->init(&result_callbacks);
		test_state_ = TestMutables();
		}

		void TearDown() override {
		FlushPartialPackets();
		while (!test_state_.reassembled.queue.empty()) {
		test_state_.reassembled.queue.pop();
		}
		packet_fragmenter_->cleanup();
		AllocationTestHarness::TearDown();
		}
		const packet_fragmenter_t* packet_fragmenter_;

		// Start acl packet
		BT_HDR* AllocateL2capPacket(size_t l2cap_length,
		const std::vector<uint8_t> data) const {
		auto packet =
		AllocateAclPacket(data.size() + sizeof(L2capPacketHeader), kStart);
		L2capHeader(packet)->length = l2cap_length;
		L2capHeader(packet)->cid = kCid;
		std::copy(data.cbegin(), data.cend(), Data(packet));
		return packet;
		}

		// Continuation acl packet
		BT_HDR* AllocateL2capPacket(const std::vector<uint8_t> data) const {
		auto packet = AllocateAclPacket(data.size(), kContinuation);
		std::copy(data.cbegin(), data.cend(), Data(packet));
		return packet;
		}

		const std::vector<uint8_t> CreateData(size_t size) const {
		CHECK(size > 0);
		std::vector<uint8_t> v(size);
		uint8_t sum = 0;
		for (size_t s = 0; s < size; s++) {
		sum += v[s] = s;
		}
		v[0] = (~sum + 1); // First byte has sum complement
		return v;
		}

		// Verify packet integrity
		bool VerifyData(const uint8_t* data, size_t size) const {
		CHECK(size > 0);
		uint8_t sum = 0;
		for (size_t s = 0; s < size; s++) {
		sum += data[s];
		}
		return sum == 0;
		}

		private:
		BT_HDR* AllocateAclPacket(size_t acl_length,
		kPacketOrder packet_order) const {
		BT_HDR* packet = AllocatePacket(sizeof(AclPacketHeader) + acl_length,
		MSG_HC_TO_STACK_HCI_ACL);
		AclHeader(packet)->s.handle = kHandle;
		AclHeader(packet)->length = acl_length;
		switch (packet_order) {
		case kStart:
		AclHeader(packet)->s.start = 1;
		break;
		case kContinuation:
		AclHeader(packet)->s.continuation = 1;
		break;
		}
		return packet;
		}

		BT_HDR* AllocatePacket(size_t packet_length, uint16_t event_mask) const {
		BT_HDR* packet =
		static_cast<BT_HDR*>(osi_calloc(sizeof(BT_HDR) + packet_length));
		packet->event = event_mask;
		packet->len = static_cast<uint16_t>(packet_length);
		return packet;
		}

		void FlushPartialPackets() const {
		while (!partial_packets.empty()) {
		BT_HDR* partial_packet = partial_packets.at(kHandle);
		partial_packets.erase(kHandle);
		osi_free(partial_packet);
		}
		}
		};

		TEST_F(HciPacketFragmenterTest, TestStruct_Handle) {
		AclPacketHeader acl_header;
		memset(&acl_header, 0, sizeof(acl_header));

		for (uint16_t h = 0; h < UINT16_MAX; h++) {
		acl_header.s.handle = h;
		CHECK(acl_header.GetHandle() == (h & HANDLE_MASK));
		CHECK(acl_header.s.continuation == 0);
		CHECK(acl_header.s.start == 0);
		CHECK(acl_header.s.reserved == 0);

		CHECK((acl_header.GetRawHandle() & HANDLE_MASK) == (h & HANDLE_MASK));
		GET_BOUNDARY_FLAG(acl_header.GetRawHandle() == 0);
		}
		}

		TEST_F(HciPacketFragmenterTest, TestStruct_Continuation) {
		AclPacketHeader acl_header;
		memset(&acl_header, 0, sizeof(acl_header));

		for (uint16_t h = 0; h < UINT16_MAX; h++) {
		acl_header.s.continuation = h;
		CHECK(acl_header.GetHandle() == 0);
		CHECK(acl_header.s.continuation == (h & 0x1));
		CHECK(acl_header.s.start == 0);
		CHECK(acl_header.s.reserved == 0);

		CHECK((acl_header.GetRawHandle() & HANDLE_MASK) == 0);
		GET_BOUNDARY_FLAG(acl_header.GetRawHandle() == (h & 0x3));
		}
		}

		TEST_F(HciPacketFragmenterTest, TestStruct_Start) {
		AclPacketHeader acl_header;
		memset(&acl_header, 0, sizeof(acl_header));

		for (uint16_t h = 0; h < UINT16_MAX; h++) {
		acl_header.s.start = h;
		CHECK(acl_header.GetHandle() == 0);
		CHECK(acl_header.s.continuation == 0);
		CHECK(acl_header.s.start == (h & 0x1));
		CHECK(acl_header.s.reserved == 0);

		CHECK((acl_header.GetRawHandle() & HANDLE_MASK) == 0);
		GET_BOUNDARY_FLAG(acl_header.GetRawHandle() == (h & 0x3));
		}
		}

		TEST_F(HciPacketFragmenterTest, TestStruct_Reserved) {
		AclPacketHeader acl_header;
		memset(&acl_header, 0, sizeof(acl_header));

		for (uint16_t h = 0; h < UINT16_MAX; h++) {
		acl_header.s.reserved = h;
		CHECK(acl_header.GetHandle() == 0);
		CHECK(acl_header.s.continuation == 0);
		CHECK(acl_header.s.start == 0);
		CHECK(acl_header.s.reserved == (h & 0x3));
		}
		}
		TEST_F(HciPacketFragmenterTest, CreateAndVerifyPackets) {
		const size_t size_check[] = {1, 2, 3, 4, 8, 16, 32,
		64, 127, 128, 129, 256, 1024, 0xfff0};
		const std::vector<size_t> sizes(
		size_check, size_check + sizeof(size_check) / sizeof(size_check[0]));

		for (const auto packet_size : sizes) {
		const std::vector<uint8_t> data = CreateData(packet_size);
		uint8_t buf[packet_size];
		std::copy(data.cbegin(), data.cend(), buf);
		CHECK(VerifyData(buf, packet_size));
		}
		}

		TEST_F(HciPacketFragmenterTest, OnePacket_Immediate) {
		const std::vector<size_t> sizes(
		kTypicalPacketSizes, kTypicalPacketSizes + kNumberOfTypicalPacketSizes);

		int reassembled_access_count = 0;
		for (const auto packet_size : sizes) {
		const std::vector<uint8_t> data = CreateData(packet_size);
		reassemble_and_dispatch(AllocateL2capPacket(data.size(), data));

		CHECK(partial_packets.size() == 0);
		CHECK(test_state_.reassembled.access_count_ == ++reassembled_access_count);
		auto packet = std::move(test_state_.reassembled.queue.front());
		test_state_.reassembled.queue.pop();
		CHECK(VerifyData(Data(packet.get()), packet_size));
		}
		}

		TEST_F(HciPacketFragmenterTest, OnePacket_ImmediateTooBig) {
		const size_t packet_size = kMaxPacketSize + 1;
		const std::vector<uint8_t> data = CreateData(packet_size);
		reassemble_and_dispatch(AllocateL2capPacket(data.size(), data));

		CHECK(partial_packets.size() == 0);
		CHECK(test_state_.reassembled.access_count_ == 0);
		}

		TEST_F(HciPacketFragmenterTest, ThreePackets_Immediate) {
		const size_t packet_size = 512;
		const std::vector<uint8_t> data = CreateData(packet_size);
		reassemble_and_dispatch(AllocateL2capPacket(data.size(), data));
		reassemble_and_dispatch(AllocateL2capPacket(data.size(), data));
		reassemble_and_dispatch(AllocateL2capPacket(data.size(), data));
		CHECK(partial_packets.size() == 0);
		CHECK(test_state_.reassembled.access_count_ == 3);
		}

		TEST_F(HciPacketFragmenterTest, OnePacket_SplitTwo) {
		const std::vector<size_t> sizes(
		kTypicalPacketSizes, kTypicalPacketSizes + kNumberOfTypicalPacketSizes);

		int reassembled_access_count = 0;
		for (auto packet_size : sizes) {
		const std::vector<uint8_t> data = CreateData(packet_size);
		const std::vector<uint8_t> part1(data.cbegin(),
		data.cbegin() + packet_size / 2);
		reassemble_and_dispatch(AllocateL2capPacket(data.size(), part1));

		CHECK(partial_packets.size() == 1);
		CHECK(test_state_.reassembled.access_count_ == reassembled_access_count);

		const std::vector<uint8_t> part2(data.cbegin() + packet_size / 2,
		data.cend());
		reassemble_and_dispatch(AllocateL2capPacket(part2));

		CHECK(partial_packets.size() == 0);
		CHECK(test_state_.reassembled.access_count_ == ++reassembled_access_count);

		auto packet = std::move(test_state_.reassembled.queue.front());
		test_state_.reassembled.queue.pop();
		CHECK(VerifyData(Data(packet.get()), packet_size));
		}
		}

		TEST_F(HciPacketFragmenterTest, OnePacket_SplitALot) {
		const size_t packet_size = 512;
		const size_t stride = 2;

		const std::vector<uint8_t> data = CreateData(packet_size);
		const std::vector<uint8_t> first_part(data.cbegin(), data.cbegin() + stride);
		reassemble_and_dispatch(AllocateL2capPacket(data.size(), first_part));
		CHECK(partial_packets.size() == 1);

		for (size_t i = 2; i < packet_size - stride; i += stride) {
		const std::vector<uint8_t> middle_part(data.cbegin() + i,
		data.cbegin() + i + stride);
		reassemble_and_dispatch(AllocateL2capPacket(middle_part));
		}
		CHECK(partial_packets.size() == 1);
		CHECK(test_state_.reassembled.access_count_ == 0);

		const std::vector<uint8_t> last_part(data.cbegin() + packet_size - stride,
		data.cend());
		reassemble_and_dispatch(AllocateL2capPacket(last_part));

		CHECK(partial_packets.size() == 0);
		CHECK(test_state_.reassembled.access_count_ == 1);
		auto packet = std::move(test_state_.reassembled.queue.front());
		CHECK(VerifyData(Data(packet.get()), packet_size));
		}

		TEST_F(HciPacketFragmenterTest, TwoPacket_InvalidLength) {
		const size_t packet_size = UINT16_MAX;
		const std::vector<uint8_t> data = CreateData(packet_size);
		const std::vector<uint8_t> first_part(data.cbegin(),
		data.cbegin() + packet_size / 2);
		reassemble_and_dispatch(AllocateL2capPacket(data.size(), first_part));

		CHECK(partial_packets.size() == 0);
		CHECK(test_state_.reassembled.access_count_ == 0);

		const std::vector<uint8_t> second_part(data.cbegin() + packet_size / 2,
		data.cend());
		reassemble_and_dispatch(AllocateL2capPacket(second_part));

		CHECK(partial_packets.size() == 0);
		CHECK(test_state_.reassembled.access_count_ == 0);
		}

		TEST_F(HciPacketFragmenterTest, TwoPacket_HugeBogusSecond) {
		const size_t packet_size = kMaxPacketSize;
		const std::vector<uint8_t> data = CreateData(UINT16_MAX);
		const std::vector<uint8_t> first_part(data.cbegin(),
		data.cbegin() + packet_size - 1);
		reassemble_and_dispatch(AllocateL2capPacket(packet_size, first_part));

		CHECK(partial_packets.size() == 1);
		CHECK(test_state_.reassembled.access_count_ == 0);

		const std::vector<uint8_t> second_part(data.cbegin() + packet_size - 1,
		data.cend());
		reassemble_and_dispatch(AllocateL2capPacket(second_part));

		CHECK(partial_packets.size() == 0);
		CHECK(test_state_.reassembled.access_count_ == 1);
		}