1/*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef TRUSTY_NVRAM_TRUSTY_NVRAM_IMPLEMENTATION_H_
18#define TRUSTY_NVRAM_TRUSTY_NVRAM_IMPLEMENTATION_H_
19
20#include <stdint.h>
21
22#include <nvram/hal/nvram_device_adapter.h>
23#include <nvram/messages/nvram_messages.h>
24
25namespace nvram {
26
27// |TrustyNvramImplementation| proxies requests to the Trusty NVRAM app. It
28// serializes the request objects, sends it to the Trusty app and finally reads
29// back the result and decodes it.
30class TrustyNvramImplementation : public nvram::NvramImplementation {
31 public:
32  ~TrustyNvramImplementation() override;
33
34  void Execute(const nvram::Request& request,
35               nvram::Response* response) override;
36
37 private:
38  // Connects the IPC channel to the Trusty app if it is not already open.
39  // Returns true if the channel is open, false on errors.
40  bool Connect();
41
42  // Dispatches a command to the trust app. Returns true if successful (note
43  // that the response may still indicate an error on the Trusty side), false if
44  // there are any I/O or encoding/decoding errors.
45  bool SendRequest(const nvram::Request& request,
46                   nvram::Response* response);
47
48  // The file descriptor for the IPC connection to the Trusty app.
49  int tipc_nvram_fd_ = -1;
50
51  // Response buffer. This puts a hard size limit on the responses from the
52  // Trusty app. 4096 matches the maximum IPC message size currently supported
53  // by Trusty.
54  uint8_t response_buffer_[4096];
55};
56
57}  // namespace nvram
58
59#endif  // TRUSTY_NVRAM_TRUSTY_NVRAM_IMPLEMENTATION_H_
60