From 7f8e819ded361e963df7aa648ca2c6d49c7b46b6 Mon Sep 17 00:00:00 2001
From: Daichi Hirono
Date: Thu, 27 Oct 2016 10:37:05 +0900
Subject: Add utility functions for FUSE.

The CL adds utility functions to framework to parse FUSE messages
from the kernel. The library will be used from framework JNI and service
JNI.

Bug: 32260320
Test: libappfuse_test
Change-Id: Ib89b26d34789e6c26a3288beceb3ea145c1ae780
---
 libappfuse/include/libappfuse/AppFuse.h | 76 +++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)
 create mode 100644 libappfuse/include/libappfuse/AppFuse.h

(limited to 'libappfuse/include/libappfuse')

diff --git a/libappfuse/include/libappfuse/AppFuse.h b/libappfuse/include/libappfuse/AppFuse.h
new file mode 100644
index 000000000..b6af48d78
--- /dev/null
+++ b/libappfuse/include/libappfuse/AppFuse.h
@@ -0,0 +1,76 @@
+/*
+ * 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_APPFUSE_H_
+#define ANDROID_LIBAPPFUSE_APPFUSE_H_
+
+#include <linux/fuse.h>
+
+namespace android {
+
+// The numbers came from sdcard.c.
+// Maximum number of bytes to write/read in one request/one reply.
+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;
+  bool Read(int fd);
+  bool Write(int fd) const;
+ private:
+  bool CheckHeaderLength() const;
+  bool CheckResult(int result, const char* operation_name) const;
+};
+
+struct FuseRequest : public FuseMessage<FuseRequest, fuse_in_header> {
+  union {
+    struct {
+      fuse_write_in write_in;
+      char write_data[kFuseMaxWrite];
+    };
+    fuse_open_in open_in;
+    fuse_init_in init_in;
+    fuse_read_in read_in;
+    char lookup_name[];
+  };
+};
+
+struct FuseResponse : public FuseMessage<FuseResponse, fuse_out_header> {
+  union {
+    fuse_init_out init_out;
+    fuse_entry_out entry_out;
+    fuse_attr_out attr_out;
+    fuse_open_out open_out;
+    char read_data[kFuseMaxRead];
+    fuse_write_out write_out;
+  };
+  void Reset(uint32_t data_length, int32_t error, uint64_t unique);
+  void ResetHeader(uint32_t data_length, int32_t error, uint64_t unique);
+};
+
+union FuseBuffer {
+  FuseRequest request;
+  FuseResponse response;
+
+  void HandleInit();
+  void HandleNotImpl();
+};
+
+}  // namespace android
+
+#endif  // ANDROID_LIBAPPFUSE_APPFUSE_H_
-- 
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