Atmosphere/stratosphere/boot/source/updater/updater_paths.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 <switch.h>
#include <stratosphere.hpp>
#include <sys/stat.h>

#include "updater_paths.hpp"

namespace sts::updater {

    namespace {

        /* Actual paths. */
        constexpr const char *BootImagePackageMountPath = "bip";
        constexpr const char *BctPathNx = "bip:/nx/bct";
        constexpr const char *Package1PathNx = "bip:/nx/package1";
        constexpr const char *Package2PathNx = "bip:/nx/package2";
        constexpr const char *BctPathA = "bip:/a/bct";
        constexpr const char *Package1PathA = "bip:/a/package1";
        constexpr const char *Package2PathA = "bip:/a/package2";

        const char *ChooseCandidatePath(const char * const *candidates, size_t num_candidates) {
            if (num_candidates == 0) {
                std::abort();
            }

            for (size_t i = 0; i < num_candidates; i++) {
                struct stat buf;
                if (stat(candidates[i], &buf) != 0) {
                    continue;
                }

                if (!S_ISREG(buf.st_mode)) {
                    continue;
                }

                return candidates[i];
            }

            /* Nintendo just uses the last candidate if they all fail...should we abort? */
            return candidates[num_candidates - 1];
        }

    }

    const char *GetBootImagePackageMountPath() {
        return BootImagePackageMountPath;
    }


    const char *GetBctPath(BootImageUpdateType boot_image_update_type) {
        switch (boot_image_update_type) {
            case BootImageUpdateType::Erista:
                {
                    constexpr const char *candidates[] = {BctPathNx};
                    return ChooseCandidatePath(candidates, sizeof(candidates) / sizeof(candidates[0]));
                }
            case BootImageUpdateType::Mariko:
                {
                    constexpr const char *candidates[] = {BctPathA, BctPathNx};
                    return ChooseCandidatePath(candidates, sizeof(candidates) / sizeof(candidates[0]));
                }
            default:
                std::abort();
        }
    }

    const char *GetPackage1Path(BootImageUpdateType boot_image_update_type) {
        switch (boot_image_update_type) {
            case BootImageUpdateType::Erista:
                {
                    constexpr const char *candidates[] = {Package1PathNx};
                    return ChooseCandidatePath(candidates, sizeof(candidates) / sizeof(candidates[0]));
                }
            case BootImageUpdateType::Mariko:
                {
                    constexpr const char *candidates[] = {Package1PathA, Package1PathNx};
                    return ChooseCandidatePath(candidates, sizeof(candidates) / sizeof(candidates[0]));
                }
            default:
                std::abort();
        }
    }

    const char *GetPackage2Path(BootImageUpdateType boot_image_update_type) {
        switch (boot_image_update_type) {
            case BootImageUpdateType::Erista:
                {
                    constexpr const char *candidates[] = {Package2PathNx};
                    return ChooseCandidatePath(candidates, sizeof(candidates) / sizeof(candidates[0]));
                }
            case BootImageUpdateType::Mariko:
                {
                    constexpr const char *candidates[] = {Package2PathA, Package2PathNx};
                    return ChooseCandidatePath(candidates, sizeof(candidates) / sizeof(candidates[0]));
                }
            default:
                std::abort();
        }
    }

}