vtoyfat/vtoyfat_linux.c

   1 /******************************************************************************
   2  * vtoyfat.c  ---- Parse fat file system
   3  *
   4  * Copyright (c) 2020, longpanda <admin@ventoy.net>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation; either version 3 of the
   9  * License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25 #include <errno.h>
  26 #include <sys/stat.h>
  27 #include <fcntl.h>
  28
  29 #include <fat_filelib.h>
  30
  31 static int g_disk_fd = 0;
  32
  33 static int vtoy_disk_read(uint32 sector, uint8 *buffer, uint32 sector_count)
  34 {
  35     lseek(g_disk_fd, sector * 512, SEEK_SET);
  36     read(g_disk_fd, buffer, sector_count * 512);
  37
  38     return 1;
  39 }
  40
  41 static int check_secure_boot(void)
  42 {
  43     void *flfile = NULL;
  44
  45     flfile = fl_fopen("/EFI/BOOT/grubx64_real.efi", "rb");
  46     if (flfile)
  47     {
  48         fl_fclose(flfile);
  49         return 0;
  50     }
  51
  52     return 1;
  53 }
  54
  55 static int get_ventoy_version(void)
  56 {
  57     int rc = 1;
  58     int size = 0;
  59     char *buf = NULL;
  60     char *pos = NULL;
  61     char *end = NULL;
  62     void *flfile = NULL;
  63
  64     flfile = fl_fopen("/grub/grub.cfg", "rb");
  65     if (flfile)
  66     {
  67         fl_fseek(flfile, 0, SEEK_END);
  68         size = (int)fl_ftell(flfile);
  69
  70         fl_fseek(flfile, 0, SEEK_SET);
  71
  72         buf = malloc(size + 1);
  73         if (buf)
  74         {
  75             fl_fread(buf, 1, size, flfile);
  76             buf[size] = 0;
  77
  78             pos = strstr(buf, "VENTOY_VERSION=");
  79             if (pos)
  80             {
  81                 pos += strlen("VENTOY_VERSION=");
  82                 if (*pos == '"')
  83                 {
  84                     pos++;
  85                 }
  86
  87                 end = pos;
  88                 while (*end != 0 && *end != '"' && *end != '\r' && *end != '\n')
  89                 {
  90                     end++;
  91                 }
  92
  93                 *end = 0;
  94
  95                 printf("%s\n", pos);
  96                 rc = 0;
  97             }
  98             free(buf);
  99         }
 100
 101         fl_fclose(flfile);
 102     }
 103
 104     return rc;
 105 }
 106
 107 int main(int argc, char **argv)
 108 {
 109     int op = 0;
 110     int rc = 1;
 111     char *disk;
 112
 113     if (argc != 2 && argc != 3)
 114     {
 115         printf("Usage: vtoyfat /dev/sdbs \n");
 116         printf("Usage: vtoyfat -s /dev/sdbs \n");
 117         return 1;
 118     }
 119
 120     if (argv[1][0] == '-' && argv[1][1] == 'T')
 121     {
 122         return 0;
 123     }
 124
 125     disk = argv[1];
 126     if (argv[1][0] == '-' && argv[1][1] == 's')
 127     {
 128         op = 1;
 129         disk = argv[2];
 130     }
 131
 132     g_disk_fd = open(disk, O_RDONLY);
 133     if (g_disk_fd < 0)
 134     {
 135         printf("Failed to open %s\n", disk);
 136         return 1;
 137     }
 138
 139     fl_init();
 140
 141     if (0 == fl_attach_media(vtoy_disk_read, NULL))
 142     {
 143         if (op == 0)
 144         {
 145             rc = get_ventoy_version();
 146         }
 147         else
 148         {
 149             rc = check_secure_boot();
 150         }
 151     }
 152
 153     fl_shutdown();
 154
 155     close(g_disk_fd);
 156
 157     return rc;
 158 }
 159