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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 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 inline struct dentry *inode_first_dentry(struct inode *inode)
  34 {
  35         wimlib_assert(inode->dentry_list.next != &inode->dentry_list);
  36         return container_of(inode->dentry_list.next, struct dentry,
  37                             inode_dentry_list);
  38 }
  39
  40 static int verify_inode(struct inode *inode, const WIMStruct *w)
  41 {
  42         const struct lookup_table *table = w->lookup_table;
  43         const struct wim_security_data *sd = wim_const_security_data(w);
  44         const struct dentry *first_dentry = inode_first_dentry(inode);
  45         int ret = WIMLIB_ERR_INVALID_DENTRY;
  46
  47         /* Check the security ID */
  48         if (inode->security_id < -1) {
  49                 ERROR("Dentry `%s' has an invalid security ID (%d)",
  50                         first_dentry->full_path_utf8, inode->security_id);
  51                 goto out;
  52         }
  53         if (inode->security_id >= sd->num_entries) {
  54                 ERROR("Dentry `%s' has an invalid security ID (%d) "
  55                       "(there are only %u entries in the security table)",
  56                         first_dentry->full_path_utf8, inode->security_id,
  57                         sd->num_entries);
  58                 goto out;
  59         }
  60
  61         /* Check that lookup table entries for all the resources exist, except
  62          * if the SHA1 message digest is all 0's, which indicates there is
  63          * intentionally no resource there.  */
  64         if (w->hdr.total_parts == 1) {
  65                 for (unsigned i = 0; i <= inode->num_ads; i++) {
  66                         struct 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 `%s'", i, first_dentry->full_path_utf8);
  73                                 goto out;
  74                         }
  75                         if (lte)
  76                                 lte->real_refcnt += inode->link_count;
  77
  78                         /* The following is now done when required by
  79                          * wim_run_full_verifications(). */
  80
  81                 #if 0
  82                         if (lte && !w->full_verification_in_progress &&
  83                             lte->real_refcnt > lte->refcnt)
  84                         {
  85                         #ifdef ENABLE_ERROR_MESSAGES
  86                                 WARNING("The following lookup table entry "
  87                                         "has a reference count of %u, but",
  88                                         lte->refcnt);
  89                                 WARNING("We found %u references to it",
  90                                         lte->real_refcnt);
  91                                 WARNING("(One dentry referencing it is at `%s')",
  92                                          first_dentry->full_path_utf8);
  93
  94                                 print_lookup_table_entry(lte);
  95                         #endif
  96                                 /* Guess what!  install.wim for Windows 8
  97                                  * contains many streams referenced by more
  98                                  * dentries than the refcnt stated in the lookup
  99                                  * table entry.  So we will need to handle this
 100                                  * case and not just make it be an error...  I'm
 101                                  * just setting the reference count to the
 102                                  * number of references we found.
 103                                  * (Unfortunately, even after doing this, the
 104                                  * reference count could be too low if it's also
 105                                  * referenced in other WIM images) */
 106
 107                         #if 1
 108                                 lte->refcnt = lte->real_refcnt;
 109                                 WARNING("Fixing reference count");
 110                         #else
 111                                 goto out;
 112                         #endif
 113                         }
 114                 #endif
 115                 }
 116         }
 117
 118         /* Make sure there is only one un-named stream. */
 119         unsigned num_unnamed_streams = 0;
 120         for (unsigned i = 0; i <= inode->num_ads; i++) {
 121                 const u8 *hash;
 122                 hash = inode_stream_hash_unresolved(inode, i);
 123                 if (!inode_stream_name_len(inode, i) && !is_zero_hash(hash))
 124                         num_unnamed_streams++;
 125         }
 126         if (num_unnamed_streams > 1) {
 127                 ERROR("Dentry `%s' has multiple (%u) un-named streams",
 128                       first_dentry->full_path_utf8, num_unnamed_streams);
 129                 goto out;
 130         }
 131         inode->verified = true;
 132         ret = 0;
 133 out:
 134         return ret;
 135 }
 136
 137 /* Run some miscellaneous verifications on a WIM dentry */
 138 int verify_dentry(struct dentry *dentry, void *wim)
 139 {
 140         int ret;
 141
 142         if (!dentry->d_inode->verified) {
 143                 ret = verify_inode(dentry->d_inode, wim);
 144                 if (ret != 0)
 145                         return ret;
 146         }
 147
 148         /* Cannot have a short name but no long name */
 149         if (dentry->short_name_len && !dentry->file_name_len) {
 150                 ERROR("Dentry `%s' has a short name but no long name",
 151                       dentry->full_path_utf8);
 152                 return WIMLIB_ERR_INVALID_DENTRY;
 153         }
 154
 155         /* Make sure root dentry is unnamed */
 156         if (dentry_is_root(dentry)) {
 157                 if (dentry->file_name_len) {
 158                         ERROR("The root dentry is named `%s', but it must "
 159                               "be unnamed", dentry->file_name_utf8);
 160                         return WIMLIB_ERR_INVALID_DENTRY;
 161                 }
 162         }
 163
 164 #if 0
 165         /* Check timestamps */
 166         if (inode->last_access_time < inode->creation_time ||
 167             inode->last_write_time < inode->creation_time) {
 168                 WARNING("Dentry `%s' was created after it was last accessed or "
 169                       "written to", dentry->full_path_utf8);
 170         }
 171 #endif
 172
 173         return 0;
 174 }
 175
 176 static int image_run_full_verifications(WIMStruct *w)
 177 {
 178         return for_dentry_in_tree(wim_root_dentry(w), verify_dentry, w);
 179 }
 180
 181 static int lte_fix_refcnt(struct lookup_table_entry *lte, void *ctr)
 182 {
 183         if (lte->refcnt != lte->real_refcnt) {
 184                 WARNING("The following lookup table entry has a reference "
 185                         "count of %u, but", lte->refcnt);
 186                 WARNING("We found %u references to it",
 187                         lte->real_refcnt);
 188                 print_lookup_table_entry(lte);
 189                 lte->refcnt = lte->real_refcnt;
 190                 ++*(unsigned long *)ctr;
 191         }
 192         return 0;
 193 }
 194
 195 /* Ideally this would be unnecessary... however, the WIMs for Windows 8 are
 196  * screwed up because some lookup table entries are referenced more times than
 197  * their stated reference counts.  So theoretically, if we delete all the
 198  * references to a stream and then remove it, it might still be referenced
 199  * somewhere else, making a file be missing from the WIM... So, work around this
 200  * problem by looking at ALL the images to re-calculate the reference count of
 201  * EVERY lookup table entry.  This only absolutely has to be done before an image
 202  * is deleted or before an image is mounted read-write. */
 203 int wim_run_full_verifications(WIMStruct *w)
 204 {
 205         int ret;
 206
 207         for_lookup_table_entry(w->lookup_table, lte_zero_real_refcnt, NULL);
 208         w->all_images_verified = 1;
 209         w->full_verification_in_progress = 1;
 210         ret = for_image(w, WIMLIB_ALL_IMAGES, image_run_full_verifications);
 211         w->full_verification_in_progress = 0;
 212         if (ret == 0) {
 213                 unsigned long num_ltes_with_bogus_refcnt = 0;
 214                 for (int i = 0; i < w->hdr.image_count; i++)
 215                         w->image_metadata[i].metadata_lte->real_refcnt++;
 216                 for_lookup_table_entry(w->lookup_table, lte_fix_refcnt,
 217                                        &num_ltes_with_bogus_refcnt);
 218                 if (num_ltes_with_bogus_refcnt != 0) {
 219                         WARNING("A total of %lu entries in the WIM's stream "
 220                                 "lookup table had to have\n"
 221                                 "          their reference counts fixed.",
 222                                 num_ltes_with_bogus_refcnt);
 223                 }
 224         } else {
 225                 w->all_images_verified = 0;
 226         }
 227         return ret;
 228 }
 229
 230 /*
 231  * Sanity checks to make sure a set of WIMs correctly correspond to a spanned
 232  * set.
 233  *
 234  * @w:
 235  *      Part 1 of the set.
 236  *
 237  * @additional_swms:
 238  *      All parts of the set other than part 1.
 239  *
 240  * @num_additional_swms:
 241  *      Number of WIMStructs in @additional_swms.  Or, the total number of parts
 242  *      in the set minus 1.
 243  *
 244  * @return:
 245  *      0 on success; WIMLIB_ERR_SPLIT_INVALID if the set is not valid.
 246  */
 247 int verify_swm_set(WIMStruct *w, WIMStruct **additional_swms,
 248                    unsigned num_additional_swms)
 249 {
 250         unsigned total_parts = w->hdr.total_parts;
 251         int ctype;
 252         const u8 *guid;
 253
 254         if (total_parts != num_additional_swms + 1) {
 255                 ERROR("`%s' says there are %u parts in the spanned set, "
 256                       "but %s%u part%s provided",
 257                       w->filename, total_parts,
 258                       (num_additional_swms + 1 < total_parts) ? "only " : "",
 259                       num_additional_swms + 1,
 260                       (num_additional_swms) ? "s were" : " was");
 261                 return WIMLIB_ERR_SPLIT_INVALID;
 262         }
 263         if (w->hdr.part_number != 1) {
 264                 ERROR("WIM `%s' is not the first part of the split WIM.",
 265                       w->filename);
 266                 return WIMLIB_ERR_SPLIT_INVALID;
 267         }
 268         for (unsigned i = 0; i < num_additional_swms; i++) {
 269                 if (additional_swms[i]->hdr.total_parts != total_parts) {
 270                         ERROR("WIM `%s' says there are %u parts in the spanned set, "
 271                               "but %u parts were provided",
 272                               additional_swms[i]->filename,
 273                               additional_swms[i]->hdr.total_parts,
 274                               total_parts);
 275                         return WIMLIB_ERR_SPLIT_INVALID;
 276                 }
 277         }
 278
 279         /* keep track of ctype and guid just to make sure they are the same for
 280          * all the WIMs. */
 281         ctype = wimlib_get_compression_type(w);
 282         guid = w->hdr.guid;
 283
 284         WIMStruct *parts_to_swms[num_additional_swms];
 285         ZERO_ARRAY(parts_to_swms);
 286         for (unsigned i = 0; i < num_additional_swms; i++) {
 287
 288                 WIMStruct *swm = additional_swms[i];
 289
 290                 if (wimlib_get_compression_type(swm) != ctype) {
 291                         ERROR("The split WIMs do not all have the same "
 292                               "compression type");
 293                         return WIMLIB_ERR_SPLIT_INVALID;
 294                 }
 295                 if (memcmp(guid, swm->hdr.guid, WIM_GID_LEN) != 0) {
 296                         ERROR("The split WIMs do not all have the same "
 297                               "GUID");
 298                         return WIMLIB_ERR_SPLIT_INVALID;
 299                 }
 300                 if (swm->hdr.part_number == 1) {
 301                         ERROR("WIMs `%s' and `%s' both are marked as the "
 302                               "first WIM in the spanned set",
 303                               w->filename, swm->filename);
 304                         return WIMLIB_ERR_SPLIT_INVALID;
 305                 }
 306                 if (swm->hdr.part_number == 0 ||
 307                     swm->hdr.part_number > total_parts)
 308                 {
 309                         ERROR("WIM `%s' says it is part %u in the spanned set, "
 310                               "but the part number must be in the range "
 311                               "[1, %u]",
 312                               swm->filename, swm->hdr.part_number, total_parts);
 313                         return WIMLIB_ERR_SPLIT_INVALID;
 314                 }
 315                 if (parts_to_swms[swm->hdr.part_number - 2])
 316                 {
 317                         ERROR("`%s' and `%s' are both marked as part %u of %u "
 318                               "in the spanned set",
 319                               parts_to_swms[swm->hdr.part_number - 2]->filename,
 320                               swm->filename,
 321                               swm->hdr.part_number,
 322                               total_parts);
 323                         return WIMLIB_ERR_SPLIT_INVALID;
 324                 } else {
 325                         parts_to_swms[swm->hdr.part_number - 2] = swm;
 326                 }
 327         }
 328         return 0;
 329 }
 330