Merge "Add FuseAppLoop to libappfuse." (1eda7847) · Commits · e / os / android_system_core

libappfuse/Android.bp

+10 −2

Original line number	Diff line number	Diff line
		@@ -15,12 +15,20 @@ cc_library_shared {
		name: "libappfuse",
		defaults: ["libappfuse_defaults"],
		export_include_dirs: ["include"],
		srcs: ["FuseBuffer.cc", "FuseBridgeLoop.cc"]
		srcs: [
		"FuseAppLoop.cc",
		"FuseBuffer.cc",
		"FuseBridgeLoop.cc",
		]
		}

		cc_test {
		name: "libappfuse_test",
		defaults: ["libappfuse_defaults"],
		shared_libs: ["libappfuse"],
		srcs: ["tests/FuseBridgeLoopTest.cc", "tests/FuseBufferTest.cc"]
		srcs: [
		"tests/FuseAppLoopTest.cc",
		"tests/FuseBridgeLoopTest.cc",
		"tests/FuseBufferTest.cc",
		]
		}

libappfuse/FuseAppLoop.cc

0 → 100644

+221 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2016 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 specic language governing permissions and
		* limitations under the License.
		*/

		#include "libappfuse/FuseAppLoop.h"

		#include <sys/stat.h>

		#include <android-base/logging.h>
		#include <android-base/unique_fd.h>

		namespace android {
		namespace fuse {

		namespace {

		void HandleLookUp(FuseBuffer* buffer, FuseAppLoopCallback* callback) {
		// AppFuse does not support directory structure now.
		// It can lookup only files under the mount point.
		if (buffer->request.header.nodeid != FUSE_ROOT_ID) {
		LOG(ERROR) << "Nodeid is not FUSE_ROOT_ID.";
		buffer->response.Reset(0, -ENOENT, buffer->request.header.unique);
		return;
		}

		// Ensure that the filename ends with 0.
		const size_t filename_length =
		buffer->request.header.len - sizeof(fuse_in_header);
		if (buffer->request.lookup_name[filename_length - 1] != 0) {
		LOG(ERROR) << "File name does not end with 0.";
		buffer->response.Reset(0, -ENOENT, buffer->request.header.unique);
		return;
		}

		const uint64_t inode =
		static_cast<uint64_t>(atol(buffer->request.lookup_name));
		if (inode == 0 \|\| inode == LONG_MAX) {
		LOG(ERROR) << "Invalid filename";
		buffer->response.Reset(0, -ENOENT, buffer->request.header.unique);
		return;
		}

		const int64_t size = callback->OnGetSize(inode);
		if (size < 0) {
		buffer->response.Reset(0, size, buffer->request.header.unique);
		return;
		}

		buffer->response.Reset(sizeof(fuse_entry_out), 0,
		buffer->request.header.unique);
		buffer->response.entry_out.nodeid = inode;
		buffer->response.entry_out.attr_valid = 10;
		buffer->response.entry_out.entry_valid = 10;
		buffer->response.entry_out.attr.ino = inode;
		buffer->response.entry_out.attr.mode = S_IFREG \| 0777;
		buffer->response.entry_out.attr.size = size;
		}

		void HandleGetAttr(FuseBuffer* buffer, FuseAppLoopCallback* callback) {
		const uint64_t nodeid = buffer->request.header.nodeid;
		int64_t size;
		uint32_t mode;
		if (nodeid == FUSE_ROOT_ID) {
		size = 0;
		mode = S_IFDIR \| 0777;
		} else {
		size = callback->OnGetSize(buffer->request.header.nodeid);
		if (size < 0) {
		buffer->response.Reset(0, size, buffer->request.header.unique);
		return;
		}
		mode = S_IFREG \| 0777;
		}

		buffer->response.Reset(sizeof(fuse_attr_out), 0,
		buffer->request.header.unique);
		buffer->response.attr_out.attr_valid = 10;
		buffer->response.attr_out.attr.ino = nodeid;
		buffer->response.attr_out.attr.mode = mode;
		buffer->response.attr_out.attr.size = size;
		}

		void HandleOpen(FuseBuffer* buffer, FuseAppLoopCallback* callback) {
		const int32_t file_handle = callback->OnOpen(buffer->request.header.nodeid);
		if (file_handle < 0) {
		buffer->response.Reset(0, file_handle, buffer->request.header.unique);
		return;
		}
		buffer->response.Reset(sizeof(fuse_open_out), kFuseSuccess,
		buffer->request.header.unique);
		buffer->response.open_out.fh = file_handle;
		}

		void HandleFsync(FuseBuffer* buffer, FuseAppLoopCallback* callback) {
		buffer->response.Reset(0, callback->OnFsync(buffer->request.header.nodeid),
		buffer->request.header.unique);
		}

		void HandleRelease(FuseBuffer* buffer, FuseAppLoopCallback* callback) {
		buffer->response.Reset(0, callback->OnRelease(buffer->request.header.nodeid),
		buffer->request.header.unique);
		}

		void HandleRead(FuseBuffer* buffer, FuseAppLoopCallback* callback) {
		const uint64_t unique = buffer->request.header.unique;
		const uint64_t nodeid = buffer->request.header.nodeid;
		const uint64_t offset = buffer->request.read_in.offset;
		const uint32_t size = buffer->request.read_in.size;

		if (size > kFuseMaxRead) {
		buffer->response.Reset(0, -EINVAL, buffer->request.header.unique);
		return;
		}

		const int32_t read_size = callback->OnRead(nodeid, offset, size,
		buffer->response.read_data);
		if (read_size < 0) {
		buffer->response.Reset(0, read_size, buffer->request.header.unique);
		return;
		}

		buffer->response.ResetHeader(read_size, kFuseSuccess, unique);
		}

		void HandleWrite(FuseBuffer* buffer, FuseAppLoopCallback* callback) {
		const uint64_t unique = buffer->request.header.unique;
		const uint64_t nodeid = buffer->request.header.nodeid;
		const uint64_t offset = buffer->request.write_in.offset;
		const uint32_t size = buffer->request.write_in.size;

		if (size > kFuseMaxWrite) {
		buffer->response.Reset(0, -EINVAL, buffer->request.header.unique);
		return;
		}

		const int32_t write_size = callback->OnWrite(nodeid, offset, size,
		buffer->request.write_data);
		if (write_size < 0) {
		buffer->response.Reset(0, write_size, buffer->request.header.unique);
		return;
		}

		buffer->response.Reset(sizeof(fuse_write_out), kFuseSuccess, unique);
		buffer->response.write_out.size = write_size;
		}

		} // namespace

		bool StartFuseAppLoop(int raw_fd, FuseAppLoopCallback* callback) {
		base::unique_fd fd(raw_fd);
		FuseBuffer buffer;

		LOG(DEBUG) << "Start fuse loop.";
		while (callback->IsActive()) {
		if (!buffer.request.Read(fd)) {
		return false;
		}

		const uint32_t opcode = buffer.request.header.opcode;
		LOG(VERBOSE) << "Read a fuse packet, opcode=" << opcode;
		switch (opcode) {
		case FUSE_FORGET:
		// Do not reply to FUSE_FORGET.
		continue;

		case FUSE_LOOKUP:
		HandleLookUp(&buffer, callback);
		break;

		case FUSE_GETATTR:
		HandleGetAttr(&buffer, callback);
		break;

		case FUSE_OPEN:
		HandleOpen(&buffer, callback);
		break;

		case FUSE_READ:
		HandleRead(&buffer, callback);
		break;

		case FUSE_WRITE:
		HandleWrite(&buffer, callback);
		break;

		case FUSE_RELEASE:
		HandleRelease(&buffer, callback);
		break;

		case FUSE_FSYNC:
		HandleFsync(&buffer, callback);
		break;

		default:
		buffer.HandleNotImpl();
		break;
		}

		if (!buffer.response.Write(fd)) {
		LOG(ERROR) << "Failed to write a response to the device.";
		return false;
		}
		}

		return true;
		}

		} // namespace fuse
		} // namespace android

libappfuse/FuseBridgeLoop.cc

+17 −8

Original line number	Diff line number	Diff line
		@@ -25,14 +25,15 @@ bool FuseBridgeLoop::Start(
		int raw_dev_fd, int raw_proxy_fd, FuseBridgeLoop::Callback* callback) {
		base::unique_fd dev_fd(raw_dev_fd);
		base::unique_fd proxy_fd(raw_proxy_fd);
		fuse::FuseBuffer buffer;

		LOG(DEBUG) << "Start fuse loop.";
		while (true) {
		if (!buffer_.request.Read(dev_fd)) {
		if (!buffer.request.Read(dev_fd)) {
		return false;
		}

		const uint32_t opcode = buffer_.request.header.opcode;
		const uint32_t opcode = buffer.request.header.opcode;
		LOG(VERBOSE) << "Read a fuse packet, opcode=" << opcode;
		switch (opcode) {
		case FUSE_FORGET:
		@@ -45,27 +46,27 @@ bool FuseBridgeLoop::Start(
		case FUSE_READ:
		case FUSE_WRITE:
		case FUSE_RELEASE:
		case FUSE_FLUSH:
		if (!buffer_.request.Write(proxy_fd)) {
		case FUSE_FSYNC:
		if (!buffer.request.Write(proxy_fd)) {
		LOG(ERROR) << "Failed to write a request to the proxy.";
		return false;
		}
		if (!buffer_.response.Read(proxy_fd)) {
		if (!buffer.response.Read(proxy_fd)) {
		LOG(ERROR) << "Failed to read a response from the proxy.";
		return false;
		}
		break;

		case FUSE_INIT:
		buffer_.HandleInit();
		buffer.HandleInit();
		break;

		default:
		buffer_.HandleNotImpl();
		buffer.HandleNotImpl();
		break;
		}

		if (!buffer_.response.Write(dev_fd)) {
		if (!buffer.response.Write(dev_fd)) {
		LOG(ERROR) << "Failed to write a response to the device.";
		return false;
		}
		@@ -76,4 +77,12 @@ bool FuseBridgeLoop::Start(
		}
		}

		namespace fuse {

		bool StartFuseBridgeLoop(
		int raw_dev_fd, int raw_proxy_fd, FuseBridgeLoopCallback* callback) {
		return FuseBridgeLoop().Start(raw_dev_fd, raw_proxy_fd, callback);
		}

		} // namespace fuse
		} // namespace android

libappfuse/FuseBuffer.cc

+11 −1

Original line number	Diff line number	Diff line
		@@ -26,6 +26,7 @@
		#include <android-base/macros.h>

		namespace android {
		namespace fuse {

		template <typename T, typename Header>
		bool FuseMessage<T, Header>::CheckHeaderLength() const {
		@@ -44,7 +45,7 @@ bool FuseMessage<T, Header>::CheckResult(
		return true;
		} else {
		PLOG(ERROR) << "Failed to " << operation_name
		<< " a packet from FD. result=" << result << " header.len="
		<< " a packet. result=" << result << " header.len="
		<< header.len;
		return false;
		}
		@@ -68,6 +69,14 @@ bool FuseMessage<T, Header>::Write(int fd) const {
		template struct FuseMessage<FuseRequest, fuse_in_header>;
		template struct FuseMessage<FuseResponse, fuse_out_header>;

		void FuseRequest::Reset(
		uint32_t data_length, uint32_t opcode, uint64_t unique) {
		memset(this, 0, sizeof(fuse_in_header) + data_length);
		header.len = sizeof(fuse_in_header) + data_length;
		header.opcode = opcode;
		header.unique = unique;
		}

		void FuseResponse::ResetHeader(
		uint32_t data_length, int32_t error, uint64_t unique) {
		CHECK_LE(error, 0) << "error should be zero or negative.";
		@@ -133,4 +142,5 @@ void FuseBuffer::HandleNotImpl() {
		response.Reset(0, -ENOSYS, unique);
		}

		} // namespace fuse
		} // namespace android

libappfuse/include/libappfuse/FuseAppLoop.h

0 → 100644

+44 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2016 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 specic language governing permissions and
		* limitations under the License.
		*/

		#ifndef ANDROID_LIBAPPFUSE_FUSEAPPLOOP_H_
		#define ANDROID_LIBAPPFUSE_FUSEAPPLOOP_H_

		#include "libappfuse/FuseBuffer.h"

		namespace android {
		namespace fuse {

		class FuseAppLoopCallback {
		public:
		virtual bool IsActive() = 0;
		virtual int64_t OnGetSize(uint64_t inode) = 0;
		virtual int32_t OnFsync(uint64_t inode) = 0;
		virtual int32_t OnWrite(
		uint64_t inode, uint64_t offset, uint32_t size, const void* data) = 0;
		virtual int32_t OnRead(
		uint64_t inode, uint64_t offset, uint32_t size, void* data) = 0;
		virtual int32_t OnOpen(uint64_t inode) = 0;
		virtual int32_t OnRelease(uint64_t inode) = 0;
		virtual ~FuseAppLoopCallback() = default;
		};

		bool StartFuseAppLoop(int fd, FuseAppLoopCallback* callback);

		} // namespace fuse
		} // namespace android

		#endif // ANDROID_LIBAPPFUSE_FUSEAPPLOOP_H_