1 //
2 // Copyright (C) 2020 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 #include <stdio.h>
17 #include <unistd.h>
18
19 #include <iostream>
20 #include <string>
21
22 #include <android-base/logging.h>
23 #include <android-base/unique_fd.h>
24 #include <libsnapshot/cow_reader.h>
25
26 namespace android {
27 namespace snapshot {
28
MyLogger(android::base::LogId,android::base::LogSeverity severity,const char *,const char *,unsigned int,const char * message)29 void MyLogger(android::base::LogId, android::base::LogSeverity severity, const char*, const char*,
30 unsigned int, const char* message) {
31 if (severity == android::base::ERROR) {
32 fprintf(stderr, "%s\n", message);
33 } else {
34 fprintf(stdout, "%s\n", message);
35 }
36 }
37
usage(void)38 static void usage(void) {
39 LOG(ERROR) << "Usage: inspect_cow [-sd] <COW_FILE>";
40 LOG(ERROR) << "\t -s Run Silent";
41 LOG(ERROR) << "\t -d Attempt to decompress";
42 LOG(ERROR) << "\t -b Show data for failed decompress\n";
43 }
44
45 // Sink that always appends to the end of a string.
46 class StringSink : public IByteSink {
47 public:
GetBuffer(size_t requested,size_t * actual)48 void* GetBuffer(size_t requested, size_t* actual) override {
49 size_t old_size = stream_.size();
50 stream_.resize(old_size + requested, '\0');
51 *actual = requested;
52 return stream_.data() + old_size;
53 }
ReturnData(void *,size_t)54 bool ReturnData(void*, size_t) override { return true; }
Reset()55 void Reset() { stream_.clear(); }
56
stream()57 std::string& stream() { return stream_; }
58
59 private:
60 std::string stream_;
61 };
62
ShowBad(CowReader & reader,const struct CowOperation & op)63 static void ShowBad(CowReader& reader, const struct CowOperation& op) {
64 size_t count;
65 auto buffer = std::make_unique<uint8_t[]>(op.data_length);
66
67 if (!reader.GetRawBytes(op.source, buffer.get(), op.data_length, &count)) {
68 std::cerr << "Failed to read at all!\n";
69 } else {
70 std::cout << "The Block data is:\n";
71 for (int i = 0; i < op.data_length; i++) {
72 std::cout << std::hex << (int)buffer[i];
73 }
74 std::cout << std::dec << "\n\n";
75 if (op.data_length >= sizeof(CowOperation)) {
76 std::cout << "The start, as an op, would be " << *(CowOperation*)buffer.get() << "\n";
77 }
78 }
79 }
80
Inspect(const std::string & path,bool silent,bool decompress,bool show_bad)81 static bool Inspect(const std::string& path, bool silent, bool decompress, bool show_bad) {
82 android::base::unique_fd fd(open(path.c_str(), O_RDONLY));
83 if (fd < 0) {
84 PLOG(ERROR) << "open failed: " << path;
85 return false;
86 }
87
88 CowReader reader;
89 if (!reader.Parse(fd)) {
90 LOG(ERROR) << "parse failed: " << path;
91 return false;
92 }
93
94 CowHeader header;
95 if (!reader.GetHeader(&header)) {
96 LOG(ERROR) << "could not get header: " << path;
97 return false;
98 }
99 CowFooter footer;
100 bool has_footer = false;
101 if (reader.GetFooter(&footer)) has_footer = true;
102
103 if (!silent) {
104 std::cout << "Major version: " << header.major_version << "\n";
105 std::cout << "Minor version: " << header.minor_version << "\n";
106 std::cout << "Header size: " << header.header_size << "\n";
107 std::cout << "Footer size: " << header.footer_size << "\n";
108 std::cout << "Block size: " << header.block_size << "\n";
109 std::cout << "\n";
110 if (has_footer) {
111 std::cout << "Total Ops size: " << footer.op.ops_size << "\n";
112 std::cout << "Number of Ops: " << footer.op.num_ops << "\n";
113 std::cout << "\n";
114 }
115 }
116
117 auto iter = reader.GetOpIter();
118 StringSink sink;
119 bool success = true;
120 while (!iter->Done()) {
121 const CowOperation& op = iter->Get();
122
123 if (!silent) std::cout << op << "\n";
124
125 if (decompress && op.type == kCowReplaceOp && op.compression != kCowCompressNone) {
126 if (!reader.ReadData(op, &sink)) {
127 std::cerr << "Failed to decompress for :" << op << "\n";
128 success = false;
129 if (show_bad) ShowBad(reader, op);
130 }
131 sink.Reset();
132 }
133
134 iter->Next();
135 }
136
137 return success;
138 }
139
140 } // namespace snapshot
141 } // namespace android
142
main(int argc,char ** argv)143 int main(int argc, char** argv) {
144 int ch;
145 bool silent = false;
146 bool decompress = false;
147 bool show_bad = false;
148 while ((ch = getopt(argc, argv, "sdb")) != -1) {
149 switch (ch) {
150 case 's':
151 silent = true;
152 break;
153 case 'd':
154 decompress = true;
155 break;
156 case 'b':
157 show_bad = true;
158 break;
159 default:
160 android::snapshot::usage();
161 }
162 }
163 android::base::InitLogging(argv, android::snapshot::MyLogger);
164
165 if (argc < optind + 1) {
166 android::snapshot::usage();
167 return 1;
168 }
169
170 if (!android::snapshot::Inspect(argv[optind], silent, decompress, show_bad)) {
171 return 1;
172 }
173 return 0;
174 }
175