Merge "Fix checks for reading and writing FuseMessage." (d619026c) · Commits · e / os / android_system_core

libappfuse/FuseBuffer.cc

+25 −12

Original line number	Original line	Diff line number	Diff line
	@@ -34,26 +34,38 @@ static_assert(
	"FuseBuffer must be standard layout union.");		"FuseBuffer must be standard layout union.");

	template <typename T>		template <typename T>
	bool FuseMessage<T>::CheckHeaderLength() const {		bool FuseMessage<T>::CheckPacketSize(size_t size, const char* name) const {
	const auto& header = static_cast<const T*>(this)->header;		const auto& header = static_cast<const T*>(this)->header;
	if (sizeof(header) <= header.len && header.len <= sizeof(T)) {		if (size >= sizeof(header) && size <= sizeof(T)) {
	return true;		return true;
	} else {		} else {
	LOG(ERROR) << "Packet size is invalid=" << header.len;		LOG(ERROR) << name << " is invalid=" << size;
	return false;		return false;
	}		}
	}		}

	template <typename T>		template <typename T>
	bool FuseMessage<T>::CheckResult(		bool FuseMessage<T>::CheckResult(int result, const char* operation_name) const {
	int result, const char* operation_name) const {		if (result == 0) {
			// Expected close of other endpoints.
			return false;
			}
			if (result < 0) {
			PLOG(ERROR) << "Failed to " << operation_name << " a packet";
			return false;
			}
			return true;
			}

			template <typename T>
			bool FuseMessage<T>::CheckHeaderLength(int result, const char* operation_name) const {
	const auto& header = static_cast<const T*>(this)->header;		const auto& header = static_cast<const T*>(this)->header;
	if (result >= 0 && static_cast<uint32_t>(result) == header.len) {		if (static_cast<uint32_t>(result) == header.len) {
	return true;		return true;
	} else {		} else {
	PLOG(ERROR) << "Failed to " << operation_name		LOG(ERROR) << "Invalid header length: operation_name=" << operation_name
	<< " a packet. result=" << result << " header.len="		<< " result=" << result
	<< header.len;		<< " header.len=" << header.len;
	return false;		return false;
	}		}
	}		}
	@@ -61,17 +73,18 @@ bool FuseMessage<T>::CheckResult(
	template <typename T>		template <typename T>
	bool FuseMessage<T>::Read(int fd) {		bool FuseMessage<T>::Read(int fd) {
	const ssize_t result = TEMP_FAILURE_RETRY(::read(fd, this, sizeof(T)));		const ssize_t result = TEMP_FAILURE_RETRY(::read(fd, this, sizeof(T)));
	return CheckHeaderLength() && CheckResult(result, "read");		return CheckResult(result, "read") && CheckPacketSize(result, "read count") &&
			CheckHeaderLength(result, "read");
	}		}

	template <typename T>		template <typename T>
	bool FuseMessage<T>::Write(int fd) const {		bool FuseMessage<T>::Write(int fd) const {
	const auto& header = static_cast<const T*>(this)->header;		const auto& header = static_cast<const T*>(this)->header;
	if (!CheckHeaderLength()) {		if (!CheckPacketSize(header.len, "header.len")) {
	return false;		return false;
	}		}
	const ssize_t result = TEMP_FAILURE_RETRY(::write(fd, this, header.len));		const ssize_t result = TEMP_FAILURE_RETRY(::write(fd, this, header.len));
	return CheckResult(result, "write");		return CheckResult(result, "write") && CheckHeaderLength(result, "write");
	}		}

	template class FuseMessage<FuseRequest>;		template class FuseMessage<FuseRequest>;

libappfuse/include/libappfuse/FuseBuffer.h

+2 −1

Original line number	Original line	Diff line number	Diff line
	@@ -34,8 +34,9 @@ class FuseMessage {
	bool Read(int fd);		bool Read(int fd);
	bool Write(int fd) const;		bool Write(int fd) const;
	private:		private:
	bool CheckHeaderLength() const;		bool CheckPacketSize(size_t size, const char* name) const;
	bool CheckResult(int result, const char* operation_name) const;		bool CheckResult(int result, const char* operation_name) const;
			bool CheckHeaderLength(int result, const char* operation_name) const;
	};		};

	// FuseRequest represents file operation requests from /dev/fuse. It starts		// FuseRequest represents file operation requests from /dev/fuse. It starts