ntloader/utils/fsuuid.c

/*
 *  ntloader  --  Microsoft Windows NT6+ loader
 *  Copyright (C) 2025  A1ive.
 *
 *  ntloader is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published
 *  by the Free Software Foundation, either version 3 of the License,
 *  or (at your option) any later version.
 *
 *  ntloader is distributed in the hope that 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 ntloader.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <ctype.h>
#ifdef _WIN32
#include <windows.h>
#endif
#include "fsuuid.h"

static int fsuuid_help (const char *prog)
{
    printf ("Usage:\n"
            "%s VOLUME\n"
#ifdef _WIN32
            "-l List all volumes\n"
#endif
            , prog);
    return 0;
}

#ifdef _WIN32
static int fsuuid_list (void)
{
    BOOL rc;
    HANDLE search;
    WCHAR volume[MAX_PATH];
    for (rc = TRUE, search = FindFirstVolumeW (volume, MAX_PATH);
         rc && search != INVALID_HANDLE_VALUE;
         rc = FindNextVolumeW (search, volume, MAX_PATH))
    {
        /* Removing trailing backslash */
        size_t len = wcslen (volume);
        if (len >= 1 && volume[len - 1] == L'\\')
            volume[len - 1] = L'\0';
        printf ("%ls\n", volume);
    }
    if (search != INVALID_HANDLE_VALUE)
        FindVolumeClose (search);
    return 0;
}
#endif

static void fsuuid_get (const char *volume)
{
    char uuid[17] = "";
    union volume_boot_record vbr;
    FILE *fd = fopen (volume, "rb");

    if (fd == NULL)
    {
        fprintf (stderr, "Could not open %s.\n", volume);
        return;
    }

    if (fread (&vbr, sizeof (vbr), 1, fd) != 1)
    {
        fprintf (stderr, "Could not read %s.\n", volume);
        fclose (fd);
        return;
    }

    if (memcmp (vbr.exfat.oem_name, "EXFAT", 5) == 0)
    {
        snprintf (uuid, 17, "%04x-%04x",
                  (uint16_t) (vbr.exfat.num_serial >> 16),
                  (uint16_t) vbr.exfat.num_serial);
    }
    else if (memcmp (vbr.ntfs.oem_name, "NTFS", 4) == 0)
    {
        snprintf (uuid, 17, "%016llx", (unsigned long long) vbr.ntfs.num_serial);
    }
    else if (memcmp (vbr.fat.version.fat12_or_fat16.fstype, "FAT12", 5) == 0)
    {
        snprintf (uuid, 17, "%04x-%04x",
                  (uint16_t) (vbr.fat.version.fat12_or_fat16.num_serial >> 16),
                  (uint16_t) vbr.fat.version.fat12_or_fat16.num_serial);
    }
    else if (memcmp (vbr.fat.version.fat12_or_fat16.fstype, "FAT16", 5) == 0)
    {
        snprintf (uuid, 17, "%04x-%04x",
                  (uint16_t) (vbr.fat.version.fat12_or_fat16.num_serial >> 16),
                  (uint16_t) vbr.fat.version.fat12_or_fat16.num_serial);
    }
    else if (memcmp (vbr.fat.version.fat32.fstype, "FAT32", 5) == 0)
    {
        snprintf (uuid, 17, "%04x-%04x",
                  (uint16_t) (vbr.fat.version.fat32.num_serial >> 16),
                  (uint16_t) vbr.fat.version.fat32.num_serial);
    }

    if (uuid[0])
        printf ("%s\n", uuid);
    else
        fprintf (stderr, "Unsupported filesystem.\n");

    fclose (fd);
}

int main (int argc, char *argv[])
{
    int i;
    if (argc <= 1)
        return fsuuid_help (argv[0]);
#ifdef _WIN32
    if (argc == 2 && strcasecmp (argv[1], "-l") == 0)
        return fsuuid_list ();
#endif
    for (i = 1; i < argc; i++)
    {
        char *volume = argv[i];
#ifdef _WIN32
        char drive_letter[] = "\\\\.\\c:";
        if (isalpha (argv[i][0])
            && (argv[i][1] == ':' || argv[i][1] == '\0')
            && strlen (argv[i]) <= 3 /* c:\ */)
        {
            drive_letter[4] = argv[i][0];
            volume = drive_letter;
        }
#endif
        fsuuid_get (volume);
    }
    return 0;
}