MuditaOS/module-vfs/vfs-utils.cpp

#include <vfs.hpp>
#include <time/time_conversion.hpp>
#include <random>
#include <ticks.hpp>
#include <source/version.hpp>

std::string vfs::generateRandomId(size_t length = 0)
{
    const std::string CHARACTERS = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

    std::random_device random_device;
    std::mt19937 generator(random_device());
    generator.seed(utils::time::Timestamp().getTime());
    std::uniform_int_distribution<> distribution(0, CHARACTERS.size() - 1);

    std::string random_string;

    for (std::size_t i = 0; i < length; ++i) {
        random_string += CHARACTERS[distribution(generator)];
    }

    return random_string;
}

void vfs::computeCRC32(vfs::FILE *file, unsigned long *outCrc32)
{
    if (outCrc32 == nullptr)
        return;

    std::unique_ptr<unsigned char[]> buf(new unsigned char[purefs::buffer::crc_buf]);
    size_t bufLen;

    *outCrc32 = 0;

    while (!::vfs.eof(file)) {
        bufLen = ::vfs.fread(buf.get(), 1, purefs::buffer::crc_buf, file);
        if (bufLen <= 0)
            break;

        *outCrc32 = Crc32_ComputeBuf(*outCrc32, buf.get(), bufLen);
    }
}

bool vfs::verifyCRC(const std::string filePath, const unsigned long crc32)
{
    unsigned long crc32Read;
    auto lamb = [](vfs::FILE *stream) { ::vfs.fclose(stream); };

    std::unique_ptr<vfs::FILE, decltype(lamb)> fp(::vfs.fopen(filePath.c_str(), "r"), lamb);

    if (fp.get() != nullptr) {
        computeCRC32(fp.get(), &crc32Read);
        return (crc32Read == crc32);
    }
    LOG_ERROR("verifyCRC can't open %s", filePath.c_str());
    return (false);
}

bool vfs::verifyCRC(const fs::path filePath)
{
    auto lamb = [](vfs::FILE *stream) { ::vfs.fclose(stream); };
    std::unique_ptr<char[]> crcBuf(new char[purefs::buffer::crc_char_size]);

    fs::path crcFilePath(filePath);
    crcFilePath += purefs::extension::crc32;

    std::unique_ptr<vfs::FILE, decltype(lamb)> fp(::vfs.fopen(crcFilePath.c_str(), "r"), lamb);

    if (fp.get() != nullptr) {
        if (::vfs.fgets(crcBuf.get(), purefs::buffer::crc_char_size, fp.get()) == NULL) {
            LOG_ERROR("verifyCRC ff_fgets on %s returned NULL", crcFilePath.c_str());
            return (false);
        }

        const unsigned long crc32Read = strtoull(crcBuf.get(), nullptr, purefs::buffer::crc_radix);
        return (verifyCRC(filePath, crc32Read));
    }
    LOG_ERROR("verifyCRC can't open %s", crcFilePath.c_str());
    return (false);
}

std::string vfs::loadFileAsString(const fs::path &fileToLoad)
{
    auto lamb = [](vfs::FILE *stream) { ::vfs.fclose(stream); };
    std::unique_ptr<char[]> readBuf(new char[purefs::buffer::tar_buf]);
    std::unique_ptr<vfs::FILE, decltype(lamb)> fp(fopen(fileToLoad.c_str(), "r"), lamb);
    std::string contents;
    size_t readSize;

    if (fp.get() != nullptr) {
        while (!eof(fp.get())) {
            readSize = fread(readBuf.get(), 1, purefs::buffer::tar_buf, fp.get());
            contents.append(static_cast<const char *>(readBuf.get()), readSize);
        }
    }

    return contents;
}

bool vfs::replaceWithString(const fs::path &fileToModify, const std::string &stringToWrite)
{
    auto lamb = [](vfs::FILE *stream) { ::vfs.fclose(stream); };
    std::unique_ptr<vfs::FILE, decltype(lamb)> fp(fopen(fileToModify.c_str(), "w"), lamb);

    if (fp.get() != nullptr) {
        size_t dataWritten = fprintf(fp.get(), stringToWrite.c_str());
        return dataWritten == stringToWrite.length();
    }
    else {
        return false;
    }

    return true;
}

const fs::path vfs::getCurrentBootJSON()
{
    if (verifyCRC(purefs::file::boot_json)) {
        return relativeToRoot(purefs::file::boot_json);
    }

    LOG_INFO("vfs::getCurrentBootJSON crc check failed on %s", purefs::file::boot_json.c_str());
    return relativeToRoot(purefs::file::boot_json);
}

bool vfs::loadBootConfig(const fs::path &bootJsonPath)
{
    std::string parseErrors  = "";
    std::string jsonContents = loadFileAsString(bootJsonPath);

    LOG_INFO("vfs::getOSRootFromJSON parsing %s", bootJsonPath.c_str());
    LOG_INFO("vfs::getOSRootFromJSON \"%s\"", jsonContents.c_str());

    bootConfig.boot_json_parsed = json11::Json::parse(jsonContents, parseErrors);

    if (parseErrors == "") {
        bootConfig.os_type  = bootConfig.boot_json_parsed[purefs::json::main][purefs::json::os_type].string_value();
        bootConfig.os_image = bootConfig.boot_json_parsed[purefs::json::main][purefs::json::os_image].string_value();
        bootConfig.os_root_path = purefs::dir::eMMC_disk / bootConfig.os_type;
        bootConfig.boot_json    = bootJsonPath;
        bootConfig.bootloader_verion =
            bootConfig.boot_json_parsed[purefs::json::bootloader][purefs::json::os_version].string_value();
        bootConfig.timestamp = utils::time::Timestamp().str("%c");

        bootConfig.setVersion(std::string(VERSION));

        LOG_INFO("boot_config: %s", bootConfig.to_json().dump().c_str());
        return true;
    }
    else {
        bootConfig.os_type      = PATH_CURRENT;
        bootConfig.os_image     = purefs::file::boot_bin;
        bootConfig.os_root_path = purefs::dir::eMMC_disk / bootConfig.os_type;
        bootConfig.boot_json    = bootJsonPath;
        bootConfig.timestamp    = utils::time::Timestamp().str("%c");

        bootConfig.setVersion(std::string(VERSION));

        LOG_WARN("vfs::getOSRootFromJSON failed to parse %s: \"%s\"", bootJsonPath.c_str(), parseErrors.c_str());
        return false;
    }
}

bool vfs::updateFileCRC32(const fs::path &file)
{
    unsigned long fileCRC32 = 0;
    auto lamb               = [](vfs::FILE *stream) { ::vfs.fclose(stream); };

    std::unique_ptr<vfs::FILE, decltype(lamb)> fp(fopen(file.c_str(), "r"), lamb);

    if (fp.get() != nullptr) {
        std::unique_ptr<char[]> crc32Buf(new char[purefs::buffer::crc_char_size]);
        computeCRC32(fp.get(), &fileCRC32);
        if (fileCRC32 != 0) {
            snprintf(&crc32Buf[0], purefs::buffer::crc_char_size, "%lX", fileCRC32);
            fs::path fileCRC32Path = file;
            fileCRC32Path += purefs::extension::crc32;

            std::unique_ptr<vfs::FILE, decltype(lamb)> fpCRC32(fopen(fileCRC32Path.c_str(), "w"), lamb);

            if (fpCRC32.get() != nullptr) {
                fprintf(fpCRC32.get(), &crc32Buf[0]);
            }
        }
    }

    return true;
}

void vfs::updateTimestamp()
{
    bootConfig.timestamp = utils::time::Timestamp().str("%c");
    LOG_INFO("vfs::updateTimestamp \"%s\"", bootConfig.to_json().dump().c_str());

    if (replaceWithString(bootConfig.boot_json, bootConfig.to_json().dump())) {
        updateFileCRC32(bootConfig.boot_json);
    }
}

json11::Json purefs::boot_config_t::to_json() const
{
    return json11::Json::object{
        {purefs::json::main,
         json11::Json::object{{purefs::json::os_image, os_image},
                              {purefs::json::os_type, os_type},
                              {purefs::json::os_version, os_version},
                              {purefs::json::timestamp, timestamp}}},

        {purefs::json::git_info,
         json11::Json::object{{purefs::json::os_git_tag, std::string(GIT_TAG)},
                              {purefs::json::os_git_revision, std::string(GIT_REV)},
                              {purefs::json::os_git_branch, std::string(GIT_BRANCH)}}},
        {purefs::json::bootloader, json11::Json::object{{purefs::json::os_version, bootloader_verion}}}};
}

void purefs::boot_config_t::setVersion(const std::string versionString)
{
    os_version = versionString;
}