Merge "Implement MessageMutator and FamilyTracker" (a7287af8) · Commits · e / os / android_hardware_interfaces

automotive/can/1.0/default/libnl++/Android.bp

+2 −0

Original line number	Diff line number	Diff line
		@@ -22,6 +22,7 @@ cc_library_static {
		"protocols/common/Empty.cpp",
		"protocols/common/Error.cpp",
		"protocols/generic/Ctrl.cpp",
		"protocols/generic/FamilyTracker.cpp",
		"protocols/generic/Generic.cpp",
		"protocols/generic/GenericMessageBase.cpp",
		"protocols/generic/Unknown.cpp",
		@@ -34,6 +35,7 @@ cc_library_static {
		"protocols/all.cpp",
		"Attributes.cpp",
		"MessageFactory.cpp",
		"MessageMutator.cpp",
		"Socket.cpp",
		"common.cpp",
		"printer.cpp",

automotive/can/1.0/default/libnl++/MessageMutator.cpp

0 → 100644

+50 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 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 <libnl++/MessageMutator.h>

		namespace android::nl {

		MessageMutator::MessageMutator(nlmsghdr* buffer, size_t totalLen)
		: mConstBuffer(buffer, totalLen), mMutableBuffer(buffer) {
		CHECK(totalLen >= sizeof(nlmsghdr));
		}

		nlmsghdr* MessageMutator::operator->() const {
		return mMutableBuffer;
		}

		MessageMutator::operator Buffer<nlmsghdr>() const {
		return mConstBuffer;
		}

		uint64_t MessageMutator::read(Buffer<nlattr> attr) const {
		return attr.data<uint64_t>().copyFirst();
		}

		void MessageMutator::write(Buffer<nlattr> attr, uint64_t val) const {
		const auto attrData = attr.data<uint64_t>();
		const auto offset = mConstBuffer.getOffset(attrData);
		CHECK(offset.has_value()) << "Trying to write attribute that's not a member of this message";

		const auto writeableBuffer = reinterpret_cast<uint8_t>(mMutableBuffer) + offset;
		const auto attrSize = attrData.getRaw().len();

		if (attrSize > sizeof(val)) memset(writeableBuffer, 0, attrSize);
		memcpy(writeableBuffer, &val, std::min(sizeof(val), attrSize));
		}

		} // namespace android::nl

automotive/can/1.0/default/libnl++/include/libnl++/Attributes.h

+19 −4

Original line number	Diff line number	Diff line
		@@ -93,14 +93,29 @@ class Attributes : private Buffer<nlattr> {
		*/
		template <typename T>
		T get(nlattrtype_t attrtype) const {
		const auto& ind = index();
		const auto it = ind.find(attrtype);
		if (it == ind.end()) {
		const auto buffer = getBuffer(attrtype);
		if (!buffer.has_value()) {
		LOG(WARNING) << "Netlink attribute is missing: " << attrtype;
		return T{};
		}

		return parse<T>(it->second);
		return parse<T>(*buffer);
		}

		/**
		* Fetches underlying buffer of a given attribute.
		*
		* This is a low-level access method unlikely to be useful in most cases. Please consider
		* using #get instead.
		*
		* \param attrtype Attribute to fetch
		* \return Attribute buffer.
		*/
		std::optional<Buffer<nlattr>> getBuffer(nlattrtype_t attrtype) const {
		const auto& ind = index();
		const auto it = ind.find(attrtype);
		if (it == ind.end()) return std::nullopt;
		return it->second;
		}

		/**

automotive/can/1.0/default/libnl++/include/libnl++/Buffer.h

+12 −0

Original line number	Diff line number	Diff line
		@@ -91,6 +91,18 @@ class Buffer {
		return {impl::data<const T, const D>(mData, offset), dataEnd()};
		}

		template <typename B>
		std::optional<uintptr_t> getOffset(Buffer<B> inner) const {
		const auto selfStart = uintptr_t(mData);
		const auto selfEnd = uintptr_t(mBufferEnd);
		const auto innerStart = uintptr_t(inner.mData);
		const auto innerEnd = uintptr_t(inner.mBufferEnd);

		if (innerStart < selfStart \|\| innerEnd > selfEnd) return std::nullopt;

		return innerStart - selfStart;
		}

		class iterator {
		public:
		iterator() : mCurrent(nullptr, size_t(0)) {

automotive/can/1.0/default/libnl++/include/libnl++/MessageMutator.h

0 → 100644

+61 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 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.
		*/

		#pragma once

		#include <libnl++/Message.h>

		namespace android::nl {

		/**
		* In-place message mutator.
		*
		* Useful for making small changes (such as adjusting const-sized attributes or struct fields)
		* efficiently and in-place. However, if you need to rebuild the message (e.g. to modify variable
		* sized attributes or add/remove them), you need to use MessageFactory instead.
		*/
		class MessageMutator {
		public:
		/**
		* Construct message mutator object from editable buffer.
		*/
		MessageMutator(nlmsghdr* buffer, size_t totalLen);

		nlmsghdr* operator->() const;
		operator Buffer<nlmsghdr>() const;

		/**
		* Read current attribute value.
		*
		* \param Read-only attribute buffer.
		* \returns Attribute value.
		*/
		uint64_t read(Buffer<nlattr> attr) const;

		/**
		* Write new attribute value.
		*
		* \param Read-only attribute buffer.
		* \param val New value to set.
		*/
		void write(Buffer<nlattr> attr, uint64_t val) const;

		private:
		const Buffer<nlmsghdr> mConstBuffer;
		nlmsghdr* mMutableBuffer;
		};

		} // namespace android::nl