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