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 #define LOG_TAG "TrustyNVRAM"
18
19 #include "trusty_nvram_implementation.h"
20
21 #include <errno.h>
22 #include <string.h>
23 #include <unistd.h>
24
25 #include <hardware/nvram.h>
26 #include <log/log.h>
27 #include <trusty/tipc.h>
28
29 #include <nvram/messages/blob.h>
30
31 namespace nvram {
32 namespace {
33
34 // Character device to open for Trusty IPC connections.
35 const char kTrustyDeviceName[] = "/dev/trusty-ipc-dev0";
36
37 // App identifier of the NVRAM app.
38 const char kTrustyNvramAppId[] = "com.android.trusty.nvram";
39
40 } // namespace
41
~TrustyNvramImplementation()42 TrustyNvramImplementation::~TrustyNvramImplementation() {
43 if (tipc_nvram_fd_ != -1) {
44 tipc_close(tipc_nvram_fd_);
45 tipc_nvram_fd_ = -1;
46 }
47 }
48
Execute(const nvram::Request & request,nvram::Response * response)49 void TrustyNvramImplementation::Execute(const nvram::Request& request,
50 nvram::Response* response) {
51 if (!SendRequest(request, response)) {
52 response->result = NV_RESULT_INTERNAL_ERROR;
53 }
54 }
55
Connect()56 bool TrustyNvramImplementation::Connect() {
57 if (tipc_nvram_fd_ != -1) {
58 return true;
59 }
60
61 int rc = tipc_connect(kTrustyDeviceName, kTrustyNvramAppId);
62 if (rc < 0) {
63 ALOGE("Failed to connect to Trusty NVRAM app: %s\n", strerror(-rc));
64 return false;
65 }
66
67 tipc_nvram_fd_ = rc;
68 return true;
69 }
70
SendRequest(const nvram::Request & request,nvram::Response * response)71 bool TrustyNvramImplementation::SendRequest(const nvram::Request& request,
72 nvram::Response* response) {
73 if (!Connect()) {
74 return false;
75 }
76
77 nvram::Blob request_buffer;
78 if (!nvram::Encode(request, &request_buffer)) {
79 ALOGE("Failed to encode NVRAM request.\n");
80 return false;
81 }
82
83 ssize_t rc =
84 write(tipc_nvram_fd_, request_buffer.data(), request_buffer.size());
85 if (rc < 0) {
86 ALOGE("Failed to send NVRAM request: %s\n", strerror(-rc));
87 return false;
88 }
89 if (static_cast<size_t>(rc) != request_buffer.size()) {
90 ALOGE("Failed to send full request buffer: %zd\n", rc);
91 return false;
92 }
93
94 rc = read(tipc_nvram_fd_, response_buffer_, sizeof(response_buffer_));
95 if (rc < 0) {
96 ALOGE("Failed to read NVRAM response: %s\n", strerror(-rc));
97 return false;
98 }
99
100 if (static_cast<size_t>(rc) >= sizeof(response_buffer_)) {
101 ALOGE("NVRAM response exceeds response buffer size.\n");
102 return false;
103 }
104
105 if (!nvram::Decode(response_buffer_, static_cast<size_t>(rc), response)) {
106 ALOGE("Failed to decode NVRAM response.\n");
107 return false;
108 }
109
110 return true;
111 }
112
113 } // namespace nvram
114