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 <errno.h>
  25 #include <sys/stat.h>
  26 #include <fcntl.h>
  27
  28 #include <fat_filelib.h>
  29
  30 static int g_disk_fd = 0;
  31
  32 static int vtoy_disk_read(uint32 sector, uint8 *buffer, uint32 sector_count)
  33 {
  34     lseek(g_disk_fd, sector * 512, SEEK_SET);
  35     read(g_disk_fd, buffer, sector_count * 512);
  36
  37     return 1;
  38 }
  39
  40 static int get_ventoy_version(void)
  41 {
  42     int rc = 1;
  43     int size = 0;
  44     char *buf = NULL;
  45     char *pos = NULL;
  46     char *end = NULL;
  47     void *flfile = NULL;
  48
  49     flfile = fl_fopen("/grub/grub.cfg", "rb");
  50     if (flfile)
  51     {
  52         fl_fseek(flfile, 0, SEEK_END);
  53         size = (int)fl_ftell(flfile);
  54
  55         fl_fseek(flfile, 0, SEEK_SET);
  56
  57         buf = malloc(size + 1);
  58         if (buf)
  59         {
  60             fl_fread(buf, 1, size, flfile);
  61             buf[size] = 0;
  62
  63             pos = strstr(buf, "VENTOY_VERSION=");
  64             if (pos)
  65             {
  66                 pos += strlen("VENTOY_VERSION=");
  67                 if (*pos == '"')
  68                 {
  69                     pos++;
  70                 }
  71
  72                 end = pos;
  73                 while (*end != 0 && *end != '"' && *end != '\r' && *end != '\n')
  74                 {
  75                     end++;
  76                 }
  77
  78                 *end = 0;
  79
  80                 printf("%s\n", pos);
  81                 rc = 0;
  82             }
  83             free(buf);
  84         }
  85
  86         fl_fclose(flfile);
  87     }
  88
  89     return rc;
  90 }
  91
  92 int main(int argc, char **argv)
  93 {
  94     int rc = 1;
  95
  96     if (argc != 2)
  97     {
  98         printf("Usage: vtoyfat /dev/sdb \n");
  99         return 1;
 100     }
 101
 102     if (argv[1][0] == '-' && argv[1][1] == 'T')
 103     {
 104         return 0;
 105     }
 106
 107     g_disk_fd = open(argv[1], O_RDONLY);
 108     if (g_disk_fd < 0)
 109     {
 110         printf("Failed to open %s\n", argv[1]);
 111         return 1;
 112     }
 113
 114     fl_init();
 115
 116     if (0 == fl_attach_media(vtoy_disk_read, NULL))
 117     {
 118         rc = get_ventoy_version();
 119     }
 120
 121     fl_shutdown();
 122
 123     close(g_disk_fd);
 124
 125     return rc;
 126 }
 127