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   1 /*
   2  * verify.c
   3  *
   4  * Some functions to verify that stuff in the WIM is valid.  Of course, not
   5  * *all* the verifications of the input data are in this file.
   6  */
   7
   8 /*
   9  * Copyright (C) 2012, 2013 Eric Biggers
  10  *
  11  * wimlib - Library for working with WIM files
  12  *
  13  * This file is part of wimlib, a library for working with WIM files.
  14  *
  15  * wimlib is free software; you can redistribute it and/or modify it under the
  16  * terms of the GNU General Public License as published by the Free
  17  * Software Foundation; either version 3 of the License, or (at your option)
  18  * any later version.
  19  *
  20  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  21  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  22  * A PARTICULAR PURPOSE. See the GNU General Public License for more
  23  * details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  27  */
  28
  29 #include "wimlib_internal.h"
  30 #include "dentry.h"
  31 #include "lookup_table.h"
  32
  33 static int verify_inode(struct wim_inode *inode, const WIMStruct *w)
  34 {
  35         const struct wim_lookup_table *table = w->lookup_table;
  36         const struct wim_security_data *sd = wim_const_security_data(w);
  37         const struct wim_dentry *first_dentry = inode_first_dentry(inode);
  38         const struct wim_dentry *dentry;
  39         int ret = WIMLIB_ERR_INVALID_DENTRY;
  40
  41         /* Check the security ID.  -1 is valid and means "no security
  42          * descriptor".  Anything else has to be a valid index into the WIM
  43          * image's security descriptors table. */
  44         if (inode->i_security_id < -1) {
  45                 ERROR("Dentry `%s' has an invalid security ID (%d)",
  46                         first_dentry->full_path, inode->i_security_id);
  47                 goto out;
  48         }
  49
  50         if (inode->i_security_id >= sd->num_entries) {
  51                 ERROR("Dentry `%s' has an invalid security ID (%d) "
  52                       "(there are only %u entries in the security table)",
  53                       first_dentry->full_path, inode->i_security_id,
  54                       sd->num_entries);
  55                 goto out;
  56         }
  57
  58         /* Check that lookup table entries for all the inode's stream exist,
  59          * except if the SHA1 message digest is all 0's, which indicates an
  60          * empty stream.
  61          *
  62          * This check is skipped on split WIMs. */
  63         if (w->hdr.total_parts == 1) {
  64                 for (unsigned i = 0; i <= inode->i_num_ads; i++) {
  65                         struct wim_lookup_table_entry *lte;
  66                         const u8 *hash;
  67                         hash = inode_stream_hash_unresolved(inode, i);
  68                         lte = __lookup_resource(table, hash);
  69                         if (!lte && !is_zero_hash(hash)) {
  70                                 ERROR("Could not find lookup table entry for stream "
  71                                       "%u of dentry `%s'", i, first_dentry->full_path);
  72                                 goto out;
  73                         }
  74                         if (lte)
  75                                 lte->real_refcnt += inode->i_nlink;
  76
  77                         /* The following is now done when required by
  78                          * wim_run_full_verifications(). */
  79
  80                 #if 0
  81                         if (lte && !w->full_verification_in_progress &&
  82                             lte->real_refcnt > lte->refcnt)
  83                         {
  84                         #ifdef ENABLE_ERROR_MESSAGES
  85                                 WARNING("The following lookup table entry "
  86                                         "has a reference count of %u, but",
  87                                         lte->refcnt);
  88                                 WARNING("We found %u references to it",
  89                                         lte->real_refcnt);
  90                                 WARNING("(One dentry referencing it is at `%s')",
  91                                          first_dentry->full_path_utf8);
  92
  93                                 print_lookup_table_entry(lte);
  94                         #endif
  95                                 /* Guess what!  install.wim for Windows 8
  96                                  * contains many streams referenced by more
  97                                  * dentries than the refcnt stated in the lookup
  98                                  * table entry.  So we will need to handle this
  99                                  * case and not just make it be an error...  I'm
 100                                  * just setting the reference count to the
 101                                  * number of references we found.
 102                                  * (Unfortunately, even after doing this, the
 103                                  * reference count could be too low if it's also
 104                                  * referenced in other WIM images) */
 105
 106                         #if 1
 107                                 lte->refcnt = lte->real_refcnt;
 108                                 WARNING("Fixing reference count");
 109                         #else
 110                                 goto out;
 111                         #endif
 112                         }
 113                 #endif
 114                 }
 115         }
 116
 117         /* Make sure there is only one unnamed data stream. */
 118         unsigned num_unnamed_streams = 0;
 119         for (unsigned i = 0; i <= inode->i_num_ads; i++) {
 120                 const u8 *hash;
 121                 hash = inode_stream_hash_unresolved(inode, i);
 122                 if (inode_stream_name_nbytes(inode, i) == 0 && !is_zero_hash(hash))
 123                         num_unnamed_streams++;
 124         }
 125         if (num_unnamed_streams > 1) {
 126                 ERROR("Dentry `%s' has multiple (%u) un-named streams",
 127                       first_dentry->full_path, num_unnamed_streams);
 128                 goto out;
 129         }
 130
 131         /* Files cannot have multiple DOS names, even if they have multiple
 132          * names in multiple directories (i.e. hard links).
 133          * Source: NTFS-3g authors. */
 134         const struct wim_dentry *dentry_with_dos_name = NULL;
 135         inode_for_each_dentry(dentry, inode) {
 136                 if (dentry_has_short_name(dentry)) {
 137                         if (dentry_with_dos_name) {
 138                                 ERROR("Hard-linked file has a DOS name at "
 139                                       "both `%s' and `%s'",
 140                                       dentry_with_dos_name->full_path,
 141                                       dentry->full_path);
 142                                 goto out;
 143                         }
 144                         dentry_with_dos_name = dentry;
 145                 }
 146         }
 147
 148         /* Directories with multiple links have not been tested. XXX */
 149         if (inode->i_nlink > 1 && inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY) {
 150                 ERROR("Hard-linked directory `%s' is unsupported",
 151                       first_dentry->full_path);
 152                 goto out;
 153         }
 154
 155         inode->i_verified = 1;
 156         ret = 0;
 157 out:
 158         return ret;
 159 }
 160
 161 /* Run some miscellaneous verifications on a WIM dentry */
 162 int verify_dentry(struct wim_dentry *dentry, void *wim)
 163 {
 164         int ret;
 165
 166         /* Verify the associated inode, but only one time no matter how many
 167          * dentries it has. */
 168         if (!dentry->d_inode->i_verified) {
 169                 ret = verify_inode(dentry->d_inode, wim);
 170                 if (ret != 0)
 171                         return ret;
 172         }
 173
 174         /* Make sure root dentry is unnamed, while every other dentry has at
 175          * least a long name.
 176          *
 177          * I am assuming that dentries having only a DOS name is illegal; i.e.,
 178          * Windows will always combine the Win32 name and DOS name for a file
 179          * into a single WIM dentry, even if they are stored separately on NTFS.
 180          * (This seems to be the case...) */
 181         if (dentry_is_root(dentry)) {
 182                 if (dentry_has_long_name(dentry) || dentry_has_short_name(dentry)) {
 183                         ERROR("The root dentry has a nonempty name!");
 184                         return WIMLIB_ERR_INVALID_DENTRY;
 185                 }
 186         } else {
 187                 if (!dentry_has_long_name(dentry)) {
 188                         ERROR("Dentry `%s' has no long name!",
 189                               dentry->full_path);
 190                         return WIMLIB_ERR_INVALID_DENTRY;
 191                 }
 192         }
 193
 194 #if 0
 195         /* Check timestamps */
 196         if (inode->i_last_access_time < inode->i_creation_time ||
 197             inode->i_last_write_time < inode->i_creation_time) {
 198                 WARNING("Dentry `%s' was created after it was last accessed or "
 199                       "written to", dentry->full_path_utf8);
 200         }
 201 #endif
 202
 203         return 0;
 204 }
 205
 206 static int image_run_full_verifications(WIMStruct *w)
 207 {
 208         return for_dentry_in_tree(wim_root_dentry(w), verify_dentry, w);
 209 }
 210
 211 static int lte_fix_refcnt(struct wim_lookup_table_entry *lte, void *ctr)
 212 {
 213         if (lte->refcnt != lte->real_refcnt) {
 214         #ifdef ENABLE_ERROR_MESSAGES
 215                 WARNING("The following lookup table entry has a reference "
 216                         "count of %u, but", lte->refcnt);
 217                 WARNING("We found %u references to it",
 218                         lte->real_refcnt);
 219                 print_lookup_table_entry(lte, stderr);
 220         #endif
 221                 lte->refcnt = lte->real_refcnt;
 222                 ++*(unsigned long *)ctr;
 223         }
 224         return 0;
 225 }
 226
 227 /* Ideally this would be unnecessary... however, the WIMs for Windows 8 are
 228  * screwed up because some lookup table entries are referenced more times than
 229  * their stated reference counts.  So theoretically, if we delete all the
 230  * references to a stream and then remove it, it might still be referenced
 231  * somewhere else, making a file be missing from the WIM... So, work around this
 232  * problem by looking at ALL the images to re-calculate the reference count of
 233  * EVERY lookup table entry.  This only absolutely has to be done before an image
 234  * is deleted or before an image is mounted read-write. */
 235 int wim_run_full_verifications(WIMStruct *w)
 236 {
 237         int ret;
 238
 239         for_lookup_table_entry(w->lookup_table, lte_zero_real_refcnt, NULL);
 240         w->all_images_verified = 1;
 241         w->full_verification_in_progress = 1;
 242         ret = for_image(w, WIMLIB_ALL_IMAGES, image_run_full_verifications);
 243         w->full_verification_in_progress = 0;
 244         if (ret == 0) {
 245                 unsigned long num_ltes_with_bogus_refcnt = 0;
 246                 for (int i = 0; i < w->hdr.image_count; i++)
 247                         w->image_metadata[i].metadata_lte->real_refcnt++;
 248                 for_lookup_table_entry(w->lookup_table, lte_fix_refcnt,
 249                                        &num_ltes_with_bogus_refcnt);
 250                 if (num_ltes_with_bogus_refcnt != 0) {
 251                         WARNING("A total of %lu entries in the WIM's stream "
 252                                 "lookup table had to have\n"
 253                                 "          their reference counts fixed.",
 254                                 num_ltes_with_bogus_refcnt);
 255                 }
 256         } else {
 257                 w->all_images_verified = 0;
 258         }
 259         return ret;
 260 }
 261
 262 /*
 263  * verify_swm_set: - Sanity checks to make sure a set of WIMs correctly
 264  *                   correspond to a spanned set.
 265  *
 266  * @w:
 267  *      Part 1 of the set.
 268  *
 269  * @additional_swms:
 270  *      All parts of the set other than part 1.
 271  *
 272  * @num_additional_swms:
 273  *      Number of WIMStructs in @additional_swms.  Or, the total number of parts
 274  *      in the set minus 1.
 275  *
 276  * @return:
 277  *      0 on success; WIMLIB_ERR_SPLIT_INVALID if the set is not valid.
 278  */
 279 int verify_swm_set(WIMStruct *w, WIMStruct **additional_swms,
 280                    unsigned num_additional_swms)
 281 {
 282         unsigned total_parts = w->hdr.total_parts;
 283         int ctype;
 284         const u8 *guid;
 285
 286         if (total_parts != num_additional_swms + 1) {
 287                 ERROR("`%s' says there are %u parts in the spanned set, "
 288                       "but %s%u part%s provided",
 289                       w->filename, total_parts,
 290                       (num_additional_swms + 1 < total_parts) ? "only " : "",
 291                       num_additional_swms + 1,
 292                       (num_additional_swms) ? "s were" : " was");
 293                 return WIMLIB_ERR_SPLIT_INVALID;
 294         }
 295         if (w->hdr.part_number != 1) {
 296                 ERROR("WIM `%s' is not the first part of the split WIM.",
 297                       w->filename);
 298                 return WIMLIB_ERR_SPLIT_INVALID;
 299         }
 300         for (unsigned i = 0; i < num_additional_swms; i++) {
 301                 if (additional_swms[i]->hdr.total_parts != total_parts) {
 302                         ERROR("WIM `%s' says there are %u parts in the spanned set, "
 303                               "but %u parts were provided",
 304                               additional_swms[i]->filename,
 305                               additional_swms[i]->hdr.total_parts,
 306                               total_parts);
 307                         return WIMLIB_ERR_SPLIT_INVALID;
 308                 }
 309         }
 310
 311         /* keep track of ctype and guid just to make sure they are the same for
 312          * all the WIMs. */
 313         ctype = wimlib_get_compression_type(w);
 314         guid = w->hdr.guid;
 315
 316         {
 317                 /* parts_to_swms is not allocated at function scope because it
 318                  * should only be allocated after num_additional_swms was
 319                  * checked to be the same as w->hdr.total_parts.  Otherwise, it
 320                  * could be unexpectedly high and cause a stack overflow. */
 321                 WIMStruct *parts_to_swms[num_additional_swms];
 322                 ZERO_ARRAY(parts_to_swms);
 323                 for (unsigned i = 0; i < num_additional_swms; i++) {
 324
 325                         WIMStruct *swm = additional_swms[i];
 326
 327                         if (wimlib_get_compression_type(swm) != ctype) {
 328                                 ERROR("The split WIMs do not all have the same "
 329                                       "compression type");
 330                                 return WIMLIB_ERR_SPLIT_INVALID;
 331                         }
 332                         if (memcmp(guid, swm->hdr.guid, WIM_GID_LEN) != 0) {
 333                                 ERROR("The split WIMs do not all have the same "
 334                                       "GUID");
 335                                 return WIMLIB_ERR_SPLIT_INVALID;
 336                         }
 337                         if (swm->hdr.part_number == 1) {
 338                                 ERROR("WIMs `%s' and `%s' both are marked as the "
 339                                       "first WIM in the spanned set",
 340                                       w->filename, swm->filename);
 341                                 return WIMLIB_ERR_SPLIT_INVALID;
 342                         }
 343                         if (swm->hdr.part_number == 0 ||
 344                             swm->hdr.part_number > total_parts)
 345                         {
 346                                 ERROR("WIM `%s' says it is part %u in the spanned set, "
 347                                       "but the part number must be in the range "
 348                                       "[1, %u]",
 349                                       swm->filename, swm->hdr.part_number, total_parts);
 350                                 return WIMLIB_ERR_SPLIT_INVALID;
 351                         }
 352                         if (parts_to_swms[swm->hdr.part_number - 2])
 353                         {
 354                                 ERROR("`%s' and `%s' are both marked as part %u of %u "
 355                                       "in the spanned set",
 356                                       parts_to_swms[swm->hdr.part_number - 2]->filename,
 357                                       swm->filename,
 358                                       swm->hdr.part_number,
 359                                       total_parts);
 360                                 return WIMLIB_ERR_SPLIT_INVALID;
 361                         } else {
 362                                 parts_to_swms[swm->hdr.part_number - 2] = swm;
 363                         }
 364                 }
 365         }
 366         return 0;
 367 }
 368