Merge "Add static assert to check if FuseBuffer is standard layout union." (a0967504) · Commits · e / os / android_system_core

libappfuse/FuseBuffer.cc

+19 −11

Original line number	Diff line number	Diff line
		@@ -21,6 +21,7 @@
		#include <unistd.h>

		#include <algorithm>
		#include <type_traits>

		#include <android-base/logging.h>
		#include <android-base/macros.h>
		@@ -28,9 +29,14 @@
		namespace android {
		namespace fuse {

		template <typename T, typename Header>
		bool FuseMessage<T, Header>::CheckHeaderLength() const {
		if (sizeof(Header) <= header.len && header.len <= sizeof(T)) {
		static_assert(
		std::is_standard_layout<FuseBuffer>::value,
		"FuseBuffer must be standard layout union.");

		template <typename T>
		bool FuseMessage<T>::CheckHeaderLength() const {
		const auto& header = static_cast<const T*>(this)->header;
		if (sizeof(header) <= header.len && header.len <= sizeof(T)) {
		return true;
		} else {
		LOG(ERROR) << "Packet size is invalid=" << header.len;
		@@ -38,9 +44,10 @@ bool FuseMessage<T, Header>::CheckHeaderLength() const {
		}
		}

		template <typename T, typename Header>
		bool FuseMessage<T, Header>::CheckResult(
		template <typename T>
		bool FuseMessage<T>::CheckResult(
		int result, const char* operation_name) const {
		const auto& header = static_cast<const T*>(this)->header;
		if (result >= 0 && static_cast<uint32_t>(result) == header.len) {
		return true;
		} else {
		@@ -51,14 +58,15 @@ bool FuseMessage<T, Header>::CheckResult(
		}
		}

		template <typename T, typename Header>
		bool FuseMessage<T, Header>::Read(int fd) {
		template <typename T>
		bool FuseMessage<T>::Read(int fd) {
		const ssize_t result = TEMP_FAILURE_RETRY(::read(fd, this, sizeof(T)));
		return CheckHeaderLength() && CheckResult(result, "read");
		}

		template <typename T, typename Header>
		bool FuseMessage<T, Header>::Write(int fd) const {
		template <typename T>
		bool FuseMessage<T>::Write(int fd) const {
		const auto& header = static_cast<const T*>(this)->header;
		if (!CheckHeaderLength()) {
		return false;
		}
		@@ -66,8 +74,8 @@ bool FuseMessage<T, Header>::Write(int fd) const {
		return CheckResult(result, "write");
		}

		template struct FuseMessage<FuseRequest, fuse_in_header>;
		template struct FuseMessage<FuseResponse, fuse_out_header>;
		template class FuseMessage<FuseRequest>;
		template class FuseMessage<FuseResponse>;

		void FuseRequest::Reset(
		uint32_t data_length, uint32_t opcode, uint64_t unique) {

libappfuse/include/libappfuse/FuseBuffer.h

+7 −5

Original line number	Diff line number	Diff line
		@@ -28,9 +28,9 @@ constexpr size_t kFuseMaxWrite = 256 * 1024;
		constexpr size_t kFuseMaxRead = 128 * 1024;
		constexpr int32_t kFuseSuccess = 0;

		template<typename T, typename Header>
		struct FuseMessage {
		Header header;
		template<typename T>
		class FuseMessage {
		public:
		bool Read(int fd);
		bool Write(int fd) const;
		private:
		@@ -40,7 +40,8 @@ struct FuseMessage {

		// FuseRequest represents file operation requests from /dev/fuse. It starts
		// from fuse_in_header. The body layout depends on the operation code.
		struct FuseRequest final : public FuseMessage<FuseRequest, fuse_in_header> {
		struct FuseRequest : public FuseMessage<FuseRequest> {
		fuse_in_header header;
		union {
		// for FUSE_WRITE
		struct {
		@@ -61,7 +62,8 @@ struct FuseRequest final : public FuseMessage<FuseRequest, fuse_in_header> {

		// FuseResponse represents file operation responses to /dev/fuse. It starts
		// from fuse_out_header. The body layout depends on the operation code.
		struct FuseResponse final : public FuseMessage<FuseResponse, fuse_out_header> {
		struct FuseResponse : public FuseMessage<FuseResponse> {
		fuse_out_header header;
		union {
		// for FUSE_INIT
		fuse_init_out init_out;