1 /*
2 * Copyright (C) 2019 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 #include "writer.h"
18
19 #include <android-base/file.h>
20
21 #include "utility.h"
22
23 using android::base::ErrnoError;
24 using android::base::Result;
25
26 namespace android {
27 namespace fs_mgr {
28
SerializeVBMetaTable(const VBMetaTable & input)29 std::string SerializeVBMetaTable(const VBMetaTable& input) {
30 std::string table;
31 table.append(reinterpret_cast<const char*>(&input.header), SUPER_VBMETA_HEADER_SIZE);
32
33 for (const auto& desc : input.descriptors) {
34 table.append(reinterpret_cast<const char*>(&desc), SUPER_VBMETA_DESCRIPTOR_SIZE);
35 table.append(desc.vbmeta_name);
36 }
37
38 // Ensure the size of vbmeta table is SUPER_VBMETA_TABLE_MAX_SIZE
39 table.resize(SUPER_VBMETA_TABLE_MAX_SIZE, '\0');
40
41 return table;
42 }
43
WritePrimaryVBMetaTable(int fd,const std::string & table)44 Result<void> WritePrimaryVBMetaTable(int fd, const std::string& table) {
45 const uint64_t offset = PRIMARY_SUPER_VBMETA_TABLE_OFFSET;
46 if (lseek(fd, offset, SEEK_SET) < 0) {
47 return ErrnoError() << __PRETTY_FUNCTION__ << " lseek failed";
48 }
49
50 if (!android::base::WriteFully(fd, table.data(), table.size())) {
51 return ErrnoError() << "Failed to write primary vbmeta table at offset " << offset;
52 }
53 return {};
54 }
55
WriteBackupVBMetaTable(int fd,const std::string & table)56 Result<void> WriteBackupVBMetaTable(int fd, const std::string& table) {
57 const uint64_t offset = BACKUP_SUPER_VBMETA_TABLE_OFFSET;
58 if (lseek(fd, offset, SEEK_SET) < 0) {
59 return ErrnoError() << __PRETTY_FUNCTION__ << " lseek failed";
60 }
61
62 if (!android::base::WriteFully(fd, table.data(), table.size())) {
63 return ErrnoError() << "Failed to write backup vbmeta table at offset " << offset;
64 }
65 return {};
66 }
67
WriteVBMetaImage(int fd,const uint8_t slot_number,const std::string & vbmeta_image)68 Result<void> WriteVBMetaImage(int fd, const uint8_t slot_number, const std::string& vbmeta_image) {
69 const uint64_t offset = IndexOffset(slot_number);
70 if (lseek(fd, offset, SEEK_SET) < 0) {
71 return ErrnoError() << __PRETTY_FUNCTION__ << " lseek failed";
72 }
73
74 if (!android::base::WriteFully(fd, vbmeta_image.data(), vbmeta_image.size())) {
75 return ErrnoError() << "Failed to write vbmeta image at offset " << offset;
76 }
77 return {};
78 }
79
80 } // namespace fs_mgr
81 } // namespace android