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Commit 3fa66c72 authored by David Anderson's avatar David Anderson
Browse files

libsnapshot: Add a tool for inspecting COW files. 

This simple tool will dump the COW header and included ops to stdout.

Bug: N/A
Test: mm inspect_cow && inspect_cow <file>
Change-Id: I369c4a21a84c95ffc10670bd9eeb2ceccb2a56d6
parent 07ad1b35

fs_mgr/libsnapshot/Android.bp

+24 −0
Original line number Diff line number Diff line
@@ -572,3 +572,27 @@ cc_test { 
    auto_gen_config: true,

    require_root: false,

}



cc_binary {

    name: "inspect_cow",

    host_supported: true,

    device_supported: true,

    cflags: [

        "-D_FILE_OFFSET_BITS=64",

        "-Wall",

        "-Werror",

    ],

    static_libs: [

        "libbase",

        "libbrotli",

        "libcrypto_static",

        "liblog",

        "libsnapshot_cow",

        "libz",

    ],

    shared_libs: [

    ],

    srcs: [

        "inspect_cow.cpp",

    ],

}

fs_mgr/libsnapshot/inspect_cow.cpp

0 → 100644
+90 −0
Original line number Diff line number Diff line 
//

// Copyright (C) 2020 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 specific language governing permissions and

// limitations under the License.

//

#include <stdio.h>



#include <iostream>

#include <string>



#include <android-base/logging.h>

#include <android-base/unique_fd.h>

#include <libsnapshot/cow_reader.h>



namespace android {

namespace snapshot {



void MyLogger(android::base::LogId, android::base::LogSeverity severity, const char*, const char*,

              unsigned int, const char* message) {

    if (severity == android::base::ERROR) {

        fprintf(stderr, "%s\n", message);

    } else {

        fprintf(stdout, "%s\n", message);

    }

}



static bool Inspect(const std::string& path) {

    android::base::unique_fd fd(open(path.c_str(), O_RDONLY));

    if (fd < 0) {

        PLOG(ERROR) << "open failed: " << path;

        return false;

    }



    CowReader reader;

    if (!reader.Parse(fd)) {

        LOG(ERROR) << "parse failed: " << path;

        return false;

    }



    CowHeader header;

    if (!reader.GetHeader(&header)) {

        LOG(ERROR) << "could not get header: " << path;

        return false;

    }



    std::cout << "Major version: " << header.major_version << "\n";

    std::cout << "Minor version: " << header.minor_version << "\n";

    std::cout << "Header size: " << header.header_size << "\n";

    std::cout << "Footer size: " << header.footer_size << "\n";

    std::cout << "Block size: " << header.block_size << "\n";

    std::cout << "\n";



    auto iter = reader.GetOpIter();

    while (!iter->Done()) {

        const CowOperation& op = iter->Get();



        std::cout << op << "\n";



        iter->Next();

    }



    return true;

}



}  // namespace snapshot

}  // namespace android



int main(int argc, char** argv) {

    android::base::InitLogging(argv, android::snapshot::MyLogger);



    if (argc < 2) {

        LOG(ERROR) << "Usage: inspect_cow <COW_FILE>";

        return 1;

    }



    if (!android::snapshot::Inspect(argv[1])) {

        return 1;

    }

    return 0;

}