Atmosphere/stratosphere/ams_mitm/source/set_mitm/setsys_mitm_service.cpp

/*
 * Copyright (c) 2018-2019 Atmosphère-NX
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include "setsys_mitm_service.hpp"

namespace ams::mitm::settings {

    using namespace ams::settings;

    namespace {

        os::Mutex g_firmware_version_lock;
        bool g_cached_firmware_version;
        settings::FirmwareVersion g_firmware_version;
        settings::FirmwareVersion g_ams_firmware_version;

        void CacheFirmwareVersion() {
            std::scoped_lock lk(g_firmware_version_lock);

            if (g_cached_firmware_version) {
                return;
            }

            /* Mount firmware version data archive. */
            R_ASSERT(romfsMountFromDataArchive(static_cast<u64>(ncm::ProgramId::ArchiveSystemVersion), NcmStorageId_BuiltInSystem, "sysver"));
            {
                ON_SCOPE_EXIT { romfsUnmount("sysver"); };

                /* Firmware version file must exist. */
                FILE *fp = fopen("sysver:/file", "rb");
                AMS_ASSERT(fp != nullptr);
                ON_SCOPE_EXIT { fclose(fp); };

                /* Must be possible to read firmware version from file. */
                AMS_ASSERT(fread(&g_firmware_version, sizeof(g_firmware_version), 1, fp) == 1);

                g_ams_firmware_version = g_firmware_version;
            }

            /* Modify the atmosphere firmware version to display a custom version string. */
            {
                const auto api_info = exosphere::GetApiInfo();
                const char emummc_char = emummc::IsActive() ? 'E' : 'S';

                /* GCC complains about the following snprintf possibly truncating, but this is not a problem and has been carefully accounted for. */
                #pragma GCC diagnostic push
                #pragma GCC diagnostic ignored "-Wformat-truncation"
                {
                    char display_version[sizeof(g_ams_firmware_version.display_version)];
                    std::snprintf(display_version, sizeof(display_version), "%s|AMS %u.%u.%u|%c", g_ams_firmware_version.display_version, api_info.major_version, api_info.minor_version, api_info.micro_version, emummc_char);
                    std::memcpy(g_ams_firmware_version.display_version, display_version, sizeof(display_version));
                }
                #pragma GCC diagnostic pop
            }

            g_cached_firmware_version = true;
        }

        Result GetFirmwareVersionImpl(settings::FirmwareVersion *out, const sm::MitmProcessInfo &client_info) {
            /* Ensure that we have the firmware version cached. */
            CacheFirmwareVersion();

            /* We want to give a special firmware version to the home menu title, and nothing else. */
            /* This means Qlaunch + Maintenance Menu, and nothing else. */
            if (client_info.program_id == ncm::ProgramId::AppletQlaunch || client_info.program_id == ncm::ProgramId::AppletMaintenanceMenu) {
                *out = g_ams_firmware_version;
            } else {
                *out = g_firmware_version;
            }

            return ResultSuccess();
        }

    }

    Result SetSysMitmService::GetFirmwareVersion(sf::Out<settings::FirmwareVersion> out) {
        R_TRY(GetFirmwareVersionImpl(out.GetPointer(), this->client_info));

        /* GetFirmwareVersion sanitizes the revision fields. */
        out.GetPointer()->revision_major = 0;
        out.GetPointer()->revision_minor = 0;
        return ResultSuccess();
    }

    Result SetSysMitmService::GetFirmwareVersion2(sf::Out<settings::FirmwareVersion> out) {
        return GetFirmwareVersionImpl(out.GetPointer(), this->client_info);
    }


}