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