GRUB2/grub-2.04/grub-core/commands/blocklist.c

   1 /* blocklist.c - print the block list of a file */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2006,2007  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/dl.h>
  21 #include <grub/misc.h>
  22 #include <grub/file.h>
  23 #include <grub/mm.h>
  24 #include <grub/disk.h>
  25 #include <grub/partition.h>
  26 #include <grub/command.h>
  27 #include <grub/i18n.h>
  28
  29 GRUB_MOD_LICENSE ("GPLv3+");
  30
  31 /* Context for grub_cmd_blocklist.  */
  32 struct blocklist_ctx
  33 {
  34   unsigned long start_sector;
  35   unsigned num_sectors;
  36   int num_entries;
  37   grub_disk_addr_t part_start;
  38 };
  39
  40 /* Helper for grub_cmd_blocklist.  */
  41 static void
  42 print_blocklist (grub_disk_addr_t sector, unsigned num,
  43                  unsigned offset, unsigned length, struct blocklist_ctx *ctx)
  44 {
  45   if (ctx->num_entries++)
  46     grub_printf (",");
  47
  48   grub_printf ("%llu", (unsigned long long) (sector - ctx->part_start));
  49   if (num > 0)
  50     grub_printf ("+%u", num);
  51   if (offset != 0 || length != 0)
  52     grub_printf ("[%u-%u]", offset, offset + length);
  53 }
  54
  55 /* Helper for grub_cmd_blocklist.  */
  56 static void
  57 read_blocklist (grub_disk_addr_t sector, unsigned offset, unsigned length,
  58                 void *data)
  59 {
  60   struct blocklist_ctx *ctx = data;
  61
  62   if (ctx->num_sectors > 0)
  63     {
  64       if (ctx->start_sector + ctx->num_sectors == sector
  65           && offset == 0 && length >= GRUB_DISK_SECTOR_SIZE)
  66         {
  67           ctx->num_sectors += length >> GRUB_DISK_SECTOR_BITS;
  68           sector += length >> GRUB_DISK_SECTOR_BITS;
  69           length &= (GRUB_DISK_SECTOR_SIZE - 1);
  70         }
  71
  72       if (!length)
  73         return;
  74       print_blocklist (ctx->start_sector, ctx->num_sectors, 0, 0, ctx);
  75       ctx->num_sectors = 0;
  76     }
  77
  78   if (offset)
  79     {
  80       unsigned l = length + offset;
  81       l &= (GRUB_DISK_SECTOR_SIZE - 1);
  82       l -= offset;
  83       print_blocklist (sector, 0, offset, l, ctx);
  84       length -= l;
  85       sector++;
  86       offset = 0;
  87     }
  88
  89   if (!length)
  90     return;
  91
  92   if (length & (GRUB_DISK_SECTOR_SIZE - 1))
  93     {
  94       if (length >> GRUB_DISK_SECTOR_BITS)
  95         {
  96           print_blocklist (sector, length >> GRUB_DISK_SECTOR_BITS, 0, 0, ctx);
  97           sector += length >> GRUB_DISK_SECTOR_BITS;
  98         }
  99       print_blocklist (sector, 0, 0, length & (GRUB_DISK_SECTOR_SIZE - 1), ctx);
 100     }
 101   else
 102     {
 103       ctx->start_sector = sector;
 104       ctx->num_sectors = length >> GRUB_DISK_SECTOR_BITS;
 105     }
 106 }
 107
 108 static grub_err_t
 109 grub_cmd_blocklist (grub_command_t cmd __attribute__ ((unused)),
 110                     int argc, char **args)
 111 {
 112   grub_file_t file;
 113   char buf[GRUB_DISK_SECTOR_SIZE];
 114   struct blocklist_ctx ctx = {
 115     .start_sector = 0,
 116     .num_sectors = 0,
 117     .num_entries = 0,
 118     .part_start = 0
 119   };
 120
 121   if (argc < 1)
 122     return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));
 123
 124   file = grub_file_open (args[0], GRUB_FILE_TYPE_PRINT_BLOCKLIST
 125                          | GRUB_FILE_TYPE_NO_DECOMPRESS);
 126   if (! file)
 127     return grub_errno;
 128
 129   if (! file->device->disk)
 130     return grub_error (GRUB_ERR_BAD_DEVICE,
 131                        "this command is available only for disk devices");
 132
 133   ctx.part_start = grub_partition_get_start (file->device->disk->partition);
 134
 135   file->read_hook = read_blocklist;
 136   file->read_hook_data = &ctx;
 137
 138   while (grub_file_read (file, buf, sizeof (buf)) > 0)
 139     ;
 140
 141   if (ctx.num_sectors > 0)
 142     print_blocklist (ctx.start_sector, ctx.num_sectors, 0, 0, &ctx);
 143
 144   grub_printf("\nentry number:%d \n", ctx.num_entries);
 145
 146   grub_file_close (file);
 147
 148   return grub_errno;
 149 }
 150
 151 static grub_command_t cmd;
 152 \f
 153 GRUB_MOD_INIT(blocklist)
 154 {
 155   cmd = grub_register_command ("blocklist", grub_cmd_blocklist,
 156                                N_("FILE"), N_("Print a block list."));
 157 }
 158
 159 GRUB_MOD_FINI(blocklist)
 160 {
 161   grub_unregister_command (cmd);
 162 }