arch/all-pc/boot/grub2-aros/grub-core/fs/tar.c

   1 /* cpio.c - cpio and tar filesystem.  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2007,2008,2009,2013 Free Software Foundation, Inc.
   5  *
   6  *  This program 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  *  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/misc.h>
  21 #include <grub/disk.h>
  22 #include <grub/archelp.h>
  23
  24 #include <grub/file.h>
  25 #include <grub/mm.h>
  26 #include <grub/dl.h>
  27 #include <grub/i18n.h>
  28
  29 GRUB_MOD_LICENSE ("GPLv3+");
  30
  31 /* tar support */
  32 #define MAGIC   "ustar"
  33 struct head
  34 {
  35   char name[100];
  36   char mode[8];
  37   char uid[8];
  38   char gid[8];
  39   char size[12];
  40   char mtime[12];
  41   char chksum[8];
  42   char typeflag;
  43   char linkname[100];
  44   char magic[6];
  45   char version[2];
  46   char uname[32];
  47   char gname[32];
  48   char devmajor[8];
  49   char devminor[8];
  50   char prefix[155];
  51 } GRUB_PACKED;
  52
  53 static inline unsigned long long
  54 read_number (const char *str, grub_size_t size)
  55 {
  56   unsigned long long ret = 0;
  57   while (size-- && *str >= '0' && *str <= '7')
  58     ret = (ret << 3) | (*str++ & 0xf);
  59   return ret;
  60 }
  61
  62 struct grub_archelp_data
  63 {
  64   grub_disk_t disk;
  65   grub_off_t hofs, next_hofs;
  66   grub_off_t dofs;
  67   grub_off_t size;
  68   char *linkname;
  69   grub_size_t linkname_alloc;
  70 };
  71
  72 static grub_err_t
  73 grub_cpio_find_file (struct grub_archelp_data *data, char **name,
  74                      grub_int32_t *mtime,
  75                      grub_uint32_t *mode)
  76 {
  77   struct head hd;
  78   int reread = 0, have_longname = 0, have_longlink = 0;
  79
  80   data->hofs = data->next_hofs;
  81
  82   for (reread = 0; reread < 3; reread++)
  83     {
  84       if (grub_disk_read (data->disk, 0, data->hofs, sizeof (hd), &hd))
  85         return grub_errno;
  86
  87       if (!hd.name[0] && !hd.prefix[0])
  88         {
  89           *mode = GRUB_ARCHELP_ATTR_END;
  90           return GRUB_ERR_NONE;
  91         }
  92
  93       if (grub_memcmp (hd.magic, MAGIC, sizeof (MAGIC) - 1))
  94         return grub_error (GRUB_ERR_BAD_FS, "invalid tar archive");
  95
  96       if (hd.typeflag == 'L')
  97         {
  98           grub_err_t err;
  99           grub_size_t namesize = read_number (hd.size, sizeof (hd.size));
 100           *name = grub_malloc (namesize + 1);
 101           if (*name == NULL)
 102             return grub_errno;
 103           err = grub_disk_read (data->disk, 0,
 104                                 data->hofs + GRUB_DISK_SECTOR_SIZE, namesize,
 105                                 *name);
 106           (*name)[namesize] = 0;
 107           if (err)
 108             return err;
 109           data->hofs += GRUB_DISK_SECTOR_SIZE
 110             + ((namesize + GRUB_DISK_SECTOR_SIZE - 1) &
 111                ~(GRUB_DISK_SECTOR_SIZE - 1));
 112           have_longname = 1;
 113           continue;
 114         }
 115
 116       if (hd.typeflag == 'K')
 117         {
 118           grub_err_t err;
 119           grub_size_t linksize = read_number (hd.size, sizeof (hd.size));
 120           if (data->linkname_alloc < linksize + 1)
 121             {
 122               char *n;
 123               n = grub_malloc (2 * (linksize + 1));
 124               if (!n)
 125                 return grub_errno;
 126               grub_free (data->linkname);
 127               data->linkname = n;
 128               data->linkname_alloc = 2 * (linksize + 1);
 129             }
 130
 131           err = grub_disk_read (data->disk, 0,
 132                                 data->hofs + GRUB_DISK_SECTOR_SIZE, linksize,
 133                                 data->linkname);
 134           if (err)
 135             return err;
 136           data->linkname[linksize] = 0;
 137           data->hofs += GRUB_DISK_SECTOR_SIZE
 138             + ((linksize + GRUB_DISK_SECTOR_SIZE - 1) &
 139                ~(GRUB_DISK_SECTOR_SIZE - 1));
 140           have_longlink = 1;
 141           continue;
 142         }
 143
 144       if (!have_longname)
 145         {
 146           grub_size_t extra_size = 0;
 147
 148           while (extra_size < sizeof (hd.prefix)
 149                  && hd.prefix[extra_size])
 150             extra_size++;
 151           *name = grub_malloc (sizeof (hd.name) + extra_size + 2);
 152           if (*name == NULL)
 153             return grub_errno;
 154           if (hd.prefix[0])
 155             {
 156               grub_memcpy (*name, hd.prefix, extra_size);
 157               (*name)[extra_size++] = '/';
 158             }
 159           grub_memcpy (*name + extra_size, hd.name, sizeof (hd.name));
 160           (*name)[extra_size + sizeof (hd.name)] = 0;
 161         }
 162
 163       data->size = read_number (hd.size, sizeof (hd.size));
 164       data->dofs = data->hofs + GRUB_DISK_SECTOR_SIZE;
 165       data->next_hofs = data->dofs + ((data->size + GRUB_DISK_SECTOR_SIZE - 1) &
 166                            ~(GRUB_DISK_SECTOR_SIZE - 1));
 167       if (mtime)
 168         *mtime = read_number (hd.mtime, sizeof (hd.mtime));
 169       if (mode)
 170         {
 171           *mode = read_number (hd.mode, sizeof (hd.mode));
 172           switch (hd.typeflag)
 173             {
 174               /* Hardlink.  */
 175             case '1':
 176               /* Symlink.  */
 177             case '2':
 178               *mode |= GRUB_ARCHELP_ATTR_LNK;
 179               break;
 180             case '0':
 181               *mode |= GRUB_ARCHELP_ATTR_FILE;
 182               break;
 183             case '5':
 184               *mode |= GRUB_ARCHELP_ATTR_DIR;
 185               break;
 186             }
 187         }
 188       if (!have_longlink)
 189         {
 190           if (data->linkname_alloc < 101)
 191             {
 192               char *n;
 193               n = grub_malloc (101);
 194               if (!n)
 195                 return grub_errno;
 196               grub_free (data->linkname);
 197               data->linkname = n;
 198               data->linkname_alloc = 101;
 199             }
 200           grub_memcpy (data->linkname, hd.linkname, sizeof (hd.linkname));
 201           data->linkname[100] = 0;
 202         }
 203       return GRUB_ERR_NONE;
 204     }
 205   return GRUB_ERR_NONE;
 206 }
 207
 208 static char *
 209 grub_cpio_get_link_target (struct grub_archelp_data *data)
 210 {
 211   return grub_strdup (data->linkname);
 212 }
 213
 214 static void
 215 grub_cpio_rewind (struct grub_archelp_data *data)
 216 {
 217   data->next_hofs = 0;
 218 }
 219
 220 static struct grub_archelp_ops arcops =
 221   {
 222     .find_file = grub_cpio_find_file,
 223     .get_link_target = grub_cpio_get_link_target,
 224     .rewind = grub_cpio_rewind
 225   };
 226
 227 static struct grub_archelp_data *
 228 grub_cpio_mount (grub_disk_t disk)
 229 {
 230   struct head hd;
 231   struct grub_archelp_data *data;
 232
 233   if (grub_disk_read (disk, 0, 0, sizeof (hd), &hd))
 234     goto fail;
 235
 236   if (grub_memcmp (hd.magic, MAGIC, sizeof (MAGIC) - 1))
 237     goto fail;
 238
 239   data = (struct grub_archelp_data *) grub_zalloc (sizeof (*data));
 240   if (!data)
 241     goto fail;
 242
 243   data->disk = disk;
 244
 245   return data;
 246
 247 fail:
 248   grub_error (GRUB_ERR_BAD_FS, "not a tarfs filesystem");
 249   return 0;
 250 }
 251
 252 static grub_err_t
 253 grub_cpio_dir (grub_device_t device, const char *path_in,
 254                grub_fs_dir_hook_t hook, void *hook_data)
 255 {
 256   struct grub_archelp_data *data;
 257   grub_err_t err;
 258
 259   data = grub_cpio_mount (device->disk);
 260   if (!data)
 261     return grub_errno;
 262
 263   err = grub_archelp_dir (data, &arcops,
 264                           path_in, hook, hook_data);
 265
 266   grub_free (data->linkname);
 267   grub_free (data);
 268
 269   return err;
 270 }
 271
 272 static grub_err_t
 273 grub_cpio_open (grub_file_t file, const char *name_in)
 274 {
 275   struct grub_archelp_data *data;
 276   grub_err_t err;
 277
 278   data = grub_cpio_mount (file->device->disk);
 279   if (!data)
 280     return grub_errno;
 281
 282   err = grub_archelp_open (data, &arcops, name_in);
 283   if (err)
 284     {
 285       grub_free (data->linkname);
 286       grub_free (data);
 287     }
 288   else
 289     {
 290       file->data = data;
 291       file->size = data->size;
 292     }
 293   return err;
 294 }
 295
 296 static grub_ssize_t
 297 grub_cpio_read (grub_file_t file, char *buf, grub_size_t len)
 298 {
 299   struct grub_archelp_data *data;
 300   grub_ssize_t ret;
 301
 302   data = file->data;
 303
 304   data->disk->read_hook = file->read_hook;
 305   data->disk->read_hook_data = file->read_hook_data;
 306   ret = (grub_disk_read (data->disk, 0, data->dofs + file->offset,
 307                          len, buf)) ? -1 : (grub_ssize_t) len;
 308   data->disk->read_hook = 0;
 309
 310   return ret;
 311 }
 312
 313 static grub_err_t
 314 grub_cpio_close (grub_file_t file)
 315 {
 316   struct grub_archelp_data *data;
 317
 318   data = file->data;
 319   grub_free (data->linkname);
 320   grub_free (data);
 321
 322   return grub_errno;
 323 }
 324
 325 static struct grub_fs grub_cpio_fs = {
 326   .name = "tarfs",
 327   .dir = grub_cpio_dir,
 328   .open = grub_cpio_open,
 329   .read = grub_cpio_read,
 330   .close = grub_cpio_close,
 331 #ifdef GRUB_UTIL
 332   .reserved_first_sector = 0,
 333   .blocklist_install = 0,
 334 #endif
 335 };
 336
 337 GRUB_MOD_INIT (tar)
 338 {
 339   grub_fs_register (&grub_cpio_fs);
 340 }
 341
 342 GRUB_MOD_FINI (tar)
 343 {
 344   grub_fs_unregister (&grub_cpio_fs);
 345 }