fsck.c

   1 #include "git-compat-util.h"
   2 #include "date.h"
   3 #include "dir.h"
   4 #include "hex.h"
   5 #include "object-store-ll.h"
   6 #include "path.h"
   7 #include "repository.h"
   8 #include "object.h"
   9 #include "attr.h"
  10 #include "blob.h"
  11 #include "tree.h"
  12 #include "tree-walk.h"
  13 #include "commit.h"
  14 #include "tag.h"
  15 #include "fsck.h"
  16 #include "refs.h"
  17 #include "url.h"
  18 #include "utf8.h"
  19 #include "decorate.h"
  20 #include "oidset.h"
  21 #include "packfile.h"
  22 #include "submodule-config.h"
  23 #include "config.h"
  24 #include "credential.h"
  25 #include "help.h"
  26
  27 #define STR(x) #x
  28 #define MSG_ID(id, msg_type) { STR(id), NULL, NULL, FSCK_##msg_type },
  29 static struct {
  30         const char *id_string;
  31         const char *downcased;
  32         const char *camelcased;
  33         enum fsck_msg_type msg_type;
  34 } msg_id_info[FSCK_MSG_MAX + 1] = {
  35         FOREACH_FSCK_MSG_ID(MSG_ID)
  36         { NULL, NULL, NULL, -1 }
  37 };
  38 #undef MSG_ID
  39 #undef STR
  40
  41 static void prepare_msg_ids(void)
  42 {
  43         int i;
  44
  45         if (msg_id_info[0].downcased)
  46                 return;
  47
  48         /* convert id_string to lower case, without underscores. */
  49         for (i = 0; i < FSCK_MSG_MAX; i++) {
  50                 const char *p = msg_id_info[i].id_string;
  51                 int len = strlen(p);
  52                 char *q = xmalloc(len);
  53
  54                 msg_id_info[i].downcased = q;
  55                 while (*p)
  56                         if (*p == '_')
  57                                 p++;
  58                         else
  59                                 *(q)++ = tolower(*(p)++);
  60                 *q = '\0';
  61
  62                 p = msg_id_info[i].id_string;
  63                 q = xmalloc(len);
  64                 msg_id_info[i].camelcased = q;
  65                 while (*p) {
  66                         if (*p == '_') {
  67                                 p++;
  68                                 if (*p)
  69                                         *q++ = *p++;
  70                         } else {
  71                                 *q++ = tolower(*p++);
  72                         }
  73                 }
  74                 *q = '\0';
  75         }
  76 }
  77
  78 static int parse_msg_id(const char *text)
  79 {
  80         int i;
  81
  82         prepare_msg_ids();
  83
  84         for (i = 0; i < FSCK_MSG_MAX; i++)
  85                 if (!strcmp(text, msg_id_info[i].downcased))
  86                         return i;
  87
  88         return -1;
  89 }
  90
  91 void list_config_fsck_msg_ids(struct string_list *list, const char *prefix)
  92 {
  93         int i;
  94
  95         prepare_msg_ids();
  96
  97         for (i = 0; i < FSCK_MSG_MAX; i++)
  98                 list_config_item(list, prefix, msg_id_info[i].camelcased);
  99 }
 100
 101 static enum fsck_msg_type fsck_msg_type(enum fsck_msg_id msg_id,
 102         struct fsck_options *options)
 103 {
 104         assert(msg_id >= 0 && msg_id < FSCK_MSG_MAX);
 105
 106         if (!options->msg_type) {
 107                 enum fsck_msg_type msg_type = msg_id_info[msg_id].msg_type;
 108
 109                 if (options->strict && msg_type == FSCK_WARN)
 110                         msg_type = FSCK_ERROR;
 111                 return msg_type;
 112         }
 113
 114         return options->msg_type[msg_id];
 115 }
 116
 117 static enum fsck_msg_type parse_msg_type(const char *str)
 118 {
 119         if (!strcmp(str, "error"))
 120                 return FSCK_ERROR;
 121         else if (!strcmp(str, "warn"))
 122                 return FSCK_WARN;
 123         else if (!strcmp(str, "ignore"))
 124                 return FSCK_IGNORE;
 125         else
 126                 die("Unknown fsck message type: '%s'", str);
 127 }
 128
 129 int is_valid_msg_type(const char *msg_id, const char *msg_type)
 130 {
 131         if (parse_msg_id(msg_id) < 0)
 132                 return 0;
 133         parse_msg_type(msg_type);
 134         return 1;
 135 }
 136
 137 void fsck_set_msg_type_from_ids(struct fsck_options *options,
 138                                 enum fsck_msg_id msg_id,
 139                                 enum fsck_msg_type msg_type)
 140 {
 141         if (!options->msg_type) {
 142                 int i;
 143                 enum fsck_msg_type *severity;
 144                 ALLOC_ARRAY(severity, FSCK_MSG_MAX);
 145                 for (i = 0; i < FSCK_MSG_MAX; i++)
 146                         severity[i] = fsck_msg_type(i, options);
 147                 options->msg_type = severity;
 148         }
 149
 150         options->msg_type[msg_id] = msg_type;
 151 }
 152
 153 void fsck_set_msg_type(struct fsck_options *options,
 154                        const char *msg_id_str, const char *msg_type_str)
 155 {
 156         int msg_id = parse_msg_id(msg_id_str);
 157         enum fsck_msg_type msg_type = parse_msg_type(msg_type_str);
 158
 159         if (msg_id < 0)
 160                 die("Unhandled message id: %s", msg_id_str);
 161
 162         if (msg_type != FSCK_ERROR && msg_id_info[msg_id].msg_type == FSCK_FATAL)
 163                 die("Cannot demote %s to %s", msg_id_str, msg_type_str);
 164
 165         fsck_set_msg_type_from_ids(options, msg_id, msg_type);
 166 }
 167
 168 void fsck_set_msg_types(struct fsck_options *options, const char *values)
 169 {
 170         char *buf = xstrdup(values), *to_free = buf;
 171         int done = 0;
 172
 173         while (!done) {
 174                 int len = strcspn(buf, " ,|"), equal;
 175
 176                 done = !buf[len];
 177                 if (!len) {
 178                         buf++;
 179                         continue;
 180                 }
 181                 buf[len] = '\0';
 182
 183                 for (equal = 0;
 184                      equal < len && buf[equal] != '=' && buf[equal] != ':';
 185                      equal++)
 186                         buf[equal] = tolower(buf[equal]);
 187                 buf[equal] = '\0';
 188
 189                 if (!strcmp(buf, "skiplist")) {
 190                         if (equal == len)
 191                                 die("skiplist requires a path");
 192                         oidset_parse_file(&options->skiplist, buf + equal + 1);
 193                         buf += len + 1;
 194                         continue;
 195                 }
 196
 197                 if (equal == len)
 198                         die("Missing '=': '%s'", buf);
 199
 200                 fsck_set_msg_type(options, buf, buf + equal + 1);
 201                 buf += len + 1;
 202         }
 203         free(to_free);
 204 }
 205
 206 static int object_on_skiplist(struct fsck_options *opts,
 207                               const struct object_id *oid)
 208 {
 209         return opts && oid && oidset_contains(&opts->skiplist, oid);
 210 }
 211
 212 __attribute__((format (printf, 5, 6)))
 213 static int report(struct fsck_options *options,
 214                   const struct object_id *oid, enum object_type object_type,
 215                   enum fsck_msg_id msg_id, const char *fmt, ...)
 216 {
 217         va_list ap;
 218         struct strbuf sb = STRBUF_INIT;
 219         enum fsck_msg_type msg_type = fsck_msg_type(msg_id, options);
 220         int result;
 221
 222         if (msg_type == FSCK_IGNORE)
 223                 return 0;
 224
 225         if (object_on_skiplist(options, oid))
 226                 return 0;
 227
 228         if (msg_type == FSCK_FATAL)
 229                 msg_type = FSCK_ERROR;
 230         else if (msg_type == FSCK_INFO)
 231                 msg_type = FSCK_WARN;
 232
 233         prepare_msg_ids();
 234         strbuf_addf(&sb, "%s: ", msg_id_info[msg_id].camelcased);
 235
 236         va_start(ap, fmt);
 237         strbuf_vaddf(&sb, fmt, ap);
 238         result = options->error_func(options, oid, object_type,
 239                                      msg_type, msg_id, sb.buf);
 240         strbuf_release(&sb);
 241         va_end(ap);
 242
 243         return result;
 244 }
 245
 246 void fsck_enable_object_names(struct fsck_options *options)
 247 {
 248         if (!options->object_names)
 249                 options->object_names = kh_init_oid_map();
 250 }
 251
 252 const char *fsck_get_object_name(struct fsck_options *options,
 253                                  const struct object_id *oid)
 254 {
 255         khiter_t pos;
 256         if (!options->object_names)
 257                 return NULL;
 258         pos = kh_get_oid_map(options->object_names, *oid);
 259         if (pos >= kh_end(options->object_names))
 260                 return NULL;
 261         return kh_value(options->object_names, pos);
 262 }
 263
 264 void fsck_put_object_name(struct fsck_options *options,
 265                           const struct object_id *oid,
 266                           const char *fmt, ...)
 267 {
 268         va_list ap;
 269         struct strbuf buf = STRBUF_INIT;
 270         khiter_t pos;
 271         int hashret;
 272
 273         if (!options->object_names)
 274                 return;
 275
 276         pos = kh_put_oid_map(options->object_names, *oid, &hashret);
 277         if (!hashret)
 278                 return;
 279         va_start(ap, fmt);
 280         strbuf_vaddf(&buf, fmt, ap);
 281         kh_value(options->object_names, pos) = strbuf_detach(&buf, NULL);
 282         va_end(ap);
 283 }
 284
 285 const char *fsck_describe_object(struct fsck_options *options,
 286                                  const struct object_id *oid)
 287 {
 288         static struct strbuf bufs[] = {
 289                 STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
 290         };
 291         static int b = 0;
 292         struct strbuf *buf;
 293         const char *name = fsck_get_object_name(options, oid);
 294
 295         buf = bufs + b;
 296         b = (b + 1) % ARRAY_SIZE(bufs);
 297         strbuf_reset(buf);
 298         strbuf_addstr(buf, oid_to_hex(oid));
 299         if (name)
 300                 strbuf_addf(buf, " (%s)", name);
 301
 302         return buf->buf;
 303 }
 304
 305 static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *options)
 306 {
 307         struct tree_desc desc;
 308         struct name_entry entry;
 309         int res = 0;
 310         const char *name;
 311
 312         if (parse_tree(tree))
 313                 return -1;
 314
 315         name = fsck_get_object_name(options, &tree->object.oid);
 316         if (init_tree_desc_gently(&desc, tree->buffer, tree->size, 0))
 317                 return -1;
 318         while (tree_entry_gently(&desc, &entry)) {
 319                 struct object *obj;
 320                 int result;
 321
 322                 if (S_ISGITLINK(entry.mode))
 323                         continue;
 324
 325                 if (S_ISDIR(entry.mode)) {
 326                         obj = (struct object *)lookup_tree(the_repository, &entry.oid);
 327                         if (name && obj)
 328                                 fsck_put_object_name(options, &entry.oid, "%s%s/",
 329                                                      name, entry.path);
 330                         result = options->walk(obj, OBJ_TREE, data, options);
 331                 }
 332                 else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode)) {
 333                         obj = (struct object *)lookup_blob(the_repository, &entry.oid);
 334                         if (name && obj)
 335                                 fsck_put_object_name(options, &entry.oid, "%s%s",
 336                                                      name, entry.path);
 337                         result = options->walk(obj, OBJ_BLOB, data, options);
 338                 }
 339                 else {
 340                         result = error("in tree %s: entry %s has bad mode %.6o",
 341                                        fsck_describe_object(options, &tree->object.oid),
 342                                        entry.path, entry.mode);
 343                 }
 344                 if (result < 0)
 345                         return result;
 346                 if (!res)
 347                         res = result;
 348         }
 349         return res;
 350 }
 351
 352 static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_options *options)
 353 {
 354         int counter = 0, generation = 0, name_prefix_len = 0;
 355         struct commit_list *parents;
 356         int res;
 357         int result;
 358         const char *name;
 359
 360         if (repo_parse_commit(the_repository, commit))
 361                 return -1;
 362
 363         name = fsck_get_object_name(options, &commit->object.oid);
 364         if (name)
 365                 fsck_put_object_name(options, get_commit_tree_oid(commit),
 366                                      "%s:", name);
 367
 368         result = options->walk((struct object *) repo_get_commit_tree(the_repository, commit),
 369                                OBJ_TREE, data, options);
 370         if (result < 0)
 371                 return result;
 372         res = result;
 373
 374         parents = commit->parents;
 375         if (name && parents) {
 376                 int len = strlen(name), power;
 377
 378                 if (len && name[len - 1] == '^') {
 379                         generation = 1;
 380                         name_prefix_len = len - 1;
 381                 }
 382                 else { /* parse ~<generation> suffix */
 383                         for (generation = 0, power = 1;
 384                              len && isdigit(name[len - 1]);
 385                              power *= 10)
 386                                 generation += power * (name[--len] - '0');
 387                         if (power > 1 && len && name[len - 1] == '~')
 388                                 name_prefix_len = len - 1;
 389                         else {
 390                                 /* Maybe a non-first parent, e.g. HEAD^2 */
 391                                 generation = 0;
 392                                 name_prefix_len = len;
 393                         }
 394                 }
 395         }
 396
 397         while (parents) {
 398                 if (name) {
 399                         struct object_id *oid = &parents->item->object.oid;
 400
 401                         if (counter++)
 402                                 fsck_put_object_name(options, oid, "%s^%d",
 403                                                      name, counter);
 404                         else if (generation > 0)
 405                                 fsck_put_object_name(options, oid, "%.*s~%d",
 406                                                      name_prefix_len, name,
 407                                                      generation + 1);
 408                         else
 409                                 fsck_put_object_name(options, oid, "%s^", name);
 410                 }
 411                 result = options->walk((struct object *)parents->item, OBJ_COMMIT, data, options);
 412                 if (result < 0)
 413                         return result;
 414                 if (!res)
 415                         res = result;
 416                 parents = parents->next;
 417         }
 418         return res;
 419 }
 420
 421 static int fsck_walk_tag(struct tag *tag, void *data, struct fsck_options *options)
 422 {
 423         const char *name = fsck_get_object_name(options, &tag->object.oid);
 424
 425         if (parse_tag(tag))
 426                 return -1;
 427         if (name)
 428                 fsck_put_object_name(options, &tag->tagged->oid, "%s", name);
 429         return options->walk(tag->tagged, OBJ_ANY, data, options);
 430 }
 431
 432 int fsck_walk(struct object *obj, void *data, struct fsck_options *options)
 433 {
 434         if (!obj)
 435                 return -1;
 436
 437         if (obj->type == OBJ_NONE)
 438                 parse_object(the_repository, &obj->oid);
 439
 440         switch (obj->type) {
 441         case OBJ_BLOB:
 442                 return 0;
 443         case OBJ_TREE:
 444                 return fsck_walk_tree((struct tree *)obj, data, options);
 445         case OBJ_COMMIT:
 446                 return fsck_walk_commit((struct commit *)obj, data, options);
 447         case OBJ_TAG:
 448                 return fsck_walk_tag((struct tag *)obj, data, options);
 449         default:
 450                 error("Unknown object type for %s",
 451                       fsck_describe_object(options, &obj->oid));
 452                 return -1;
 453         }
 454 }
 455
 456 struct name_stack {
 457         const char **names;
 458         size_t nr, alloc;
 459 };
 460
 461 static void name_stack_push(struct name_stack *stack, const char *name)
 462 {
 463         ALLOC_GROW(stack->names, stack->nr + 1, stack->alloc);
 464         stack->names[stack->nr++] = name;
 465 }
 466
 467 static const char *name_stack_pop(struct name_stack *stack)
 468 {
 469         return stack->nr ? stack->names[--stack->nr] : NULL;
 470 }
 471
 472 static void name_stack_clear(struct name_stack *stack)
 473 {
 474         FREE_AND_NULL(stack->names);
 475         stack->nr = stack->alloc = 0;
 476 }
 477
 478 /*
 479  * The entries in a tree are ordered in the _path_ order,
 480  * which means that a directory entry is ordered by adding
 481  * a slash to the end of it.
 482  *
 483  * So a directory called "a" is ordered _after_ a file
 484  * called "a.c", because "a/" sorts after "a.c".
 485  */
 486 #define TREE_UNORDERED (-1)
 487 #define TREE_HAS_DUPS  (-2)
 488
 489 static int is_less_than_slash(unsigned char c)
 490 {
 491         return '\0' < c && c < '/';
 492 }
 493
 494 static int verify_ordered(unsigned mode1, const char *name1,
 495                           unsigned mode2, const char *name2,
 496                           struct name_stack *candidates)
 497 {
 498         int len1 = strlen(name1);
 499         int len2 = strlen(name2);
 500         int len = len1 < len2 ? len1 : len2;
 501         unsigned char c1, c2;
 502         int cmp;
 503
 504         cmp = memcmp(name1, name2, len);
 505         if (cmp < 0)
 506                 return 0;
 507         if (cmp > 0)
 508                 return TREE_UNORDERED;
 509
 510         /*
 511          * Ok, the first <len> characters are the same.
 512          * Now we need to order the next one, but turn
 513          * a '\0' into a '/' for a directory entry.
 514          */
 515         c1 = name1[len];
 516         c2 = name2[len];
 517         if (!c1 && !c2)
 518                 /*
 519                  * git-write-tree used to write out a nonsense tree that has
 520                  * entries with the same name, one blob and one tree.  Make
 521                  * sure we do not have duplicate entries.
 522                  */
 523                 return TREE_HAS_DUPS;
 524         if (!c1 && S_ISDIR(mode1))
 525                 c1 = '/';
 526         if (!c2 && S_ISDIR(mode2))
 527                 c2 = '/';
 528
 529         /*
 530          * There can be non-consecutive duplicates due to the implicitly
 531          * added slash, e.g.:
 532          *
 533          *   foo
 534          *   foo.bar
 535          *   foo.bar.baz
 536          *   foo.bar/
 537          *   foo/
 538          *
 539          * Record non-directory candidates (like "foo" and "foo.bar" in
 540          * the example) on a stack and check directory candidates (like
 541          * foo/" and "foo.bar/") against that stack.
 542          */
 543         if (!c1 && is_less_than_slash(c2)) {
 544                 name_stack_push(candidates, name1);
 545         } else if (c2 == '/' && is_less_than_slash(c1)) {
 546                 for (;;) {
 547                         const char *p;
 548                         const char *f_name = name_stack_pop(candidates);
 549
 550                         if (!f_name)
 551                                 break;
 552                         if (!skip_prefix(name2, f_name, &p))
 553                                 continue;
 554                         if (!*p)
 555                                 return TREE_HAS_DUPS;
 556                         if (is_less_than_slash(*p)) {
 557                                 name_stack_push(candidates, f_name);
 558                                 break;
 559                         }
 560                 }
 561         }
 562
 563         return c1 < c2 ? 0 : TREE_UNORDERED;
 564 }
 565
 566 static int fsck_tree(const struct object_id *tree_oid,
 567                      const char *buffer, unsigned long size,
 568                      struct fsck_options *options)
 569 {
 570         int retval = 0;
 571         int has_null_sha1 = 0;
 572         int has_full_path = 0;
 573         int has_empty_name = 0;
 574         int has_dot = 0;
 575         int has_dotdot = 0;
 576         int has_dotgit = 0;
 577         int has_zero_pad = 0;
 578         int has_bad_modes = 0;
 579         int has_dup_entries = 0;
 580         int not_properly_sorted = 0;
 581         struct tree_desc desc;
 582         unsigned o_mode;
 583         const char *o_name;
 584         struct name_stack df_dup_candidates = { NULL };
 585
 586         if (init_tree_desc_gently(&desc, buffer, size, TREE_DESC_RAW_MODES)) {
 587                 retval += report(options, tree_oid, OBJ_TREE,
 588                                  FSCK_MSG_BAD_TREE,
 589                                  "cannot be parsed as a tree");
 590                 return retval;
 591         }
 592
 593         o_mode = 0;
 594         o_name = NULL;
 595
 596         while (desc.size) {
 597                 unsigned short mode;
 598                 const char *name, *backslash;
 599                 const struct object_id *entry_oid;
 600
 601                 entry_oid = tree_entry_extract(&desc, &name, &mode);
 602
 603                 has_null_sha1 |= is_null_oid(entry_oid);
 604                 has_full_path |= !!strchr(name, '/');
 605                 has_empty_name |= !*name;
 606                 has_dot |= !strcmp(name, ".");
 607                 has_dotdot |= !strcmp(name, "..");
 608                 has_dotgit |= is_hfs_dotgit(name) || is_ntfs_dotgit(name);
 609                 has_zero_pad |= *(char *)desc.buffer == '0';
 610
 611                 if (is_hfs_dotgitmodules(name) || is_ntfs_dotgitmodules(name)) {
 612                         if (!S_ISLNK(mode))
 613                                 oidset_insert(&options->gitmodules_found,
 614                                               entry_oid);
 615                         else
 616                                 retval += report(options,
 617                                                  tree_oid, OBJ_TREE,
 618                                                  FSCK_MSG_GITMODULES_SYMLINK,
 619                                                  ".gitmodules is a symbolic link");
 620                 }
 621
 622                 if (is_hfs_dotgitattributes(name) || is_ntfs_dotgitattributes(name)) {
 623                         if (!S_ISLNK(mode))
 624                                 oidset_insert(&options->gitattributes_found,
 625                                               entry_oid);
 626                         else
 627                                 retval += report(options, tree_oid, OBJ_TREE,
 628                                                  FSCK_MSG_GITATTRIBUTES_SYMLINK,
 629                                                  ".gitattributes is a symlink");
 630                 }
 631
 632                 if (S_ISLNK(mode)) {
 633                         if (is_hfs_dotgitignore(name) ||
 634                             is_ntfs_dotgitignore(name))
 635                                 retval += report(options, tree_oid, OBJ_TREE,
 636                                                  FSCK_MSG_GITIGNORE_SYMLINK,
 637                                                  ".gitignore is a symlink");
 638                         if (is_hfs_dotmailmap(name) ||
 639                             is_ntfs_dotmailmap(name))
 640                                 retval += report(options, tree_oid, OBJ_TREE,
 641                                                  FSCK_MSG_MAILMAP_SYMLINK,
 642                                                  ".mailmap is a symlink");
 643                 }
 644
 645                 if ((backslash = strchr(name, '\\'))) {
 646                         while (backslash) {
 647                                 backslash++;
 648                                 has_dotgit |= is_ntfs_dotgit(backslash);
 649                                 if (is_ntfs_dotgitmodules(backslash)) {
 650                                         if (!S_ISLNK(mode))
 651                                                 oidset_insert(&options->gitmodules_found,
 652                                                               entry_oid);
 653                                         else
 654                                                 retval += report(options, tree_oid, OBJ_TREE,
 655                                                                  FSCK_MSG_GITMODULES_SYMLINK,
 656                                                                  ".gitmodules is a symbolic link");
 657                                 }
 658                                 backslash = strchr(backslash, '\\');
 659                         }
 660                 }
 661
 662                 if (update_tree_entry_gently(&desc)) {
 663                         retval += report(options, tree_oid, OBJ_TREE,
 664                                          FSCK_MSG_BAD_TREE,
 665                                          "cannot be parsed as a tree");
 666                         break;
 667                 }
 668
 669                 switch (mode) {
 670                 /*
 671                  * Standard modes..
 672                  */
 673                 case S_IFREG | 0755:
 674                 case S_IFREG | 0644:
 675                 case S_IFLNK:
 676                 case S_IFDIR:
 677                 case S_IFGITLINK:
 678                         break;
 679                 /*
 680                  * This is nonstandard, but we had a few of these
 681                  * early on when we honored the full set of mode
 682                  * bits..
 683                  */
 684                 case S_IFREG | 0664:
 685                         if (!options->strict)
 686                                 break;
 687                         /* fallthrough */
 688                 default:
 689                         has_bad_modes = 1;
 690                 }
 691
 692                 if (o_name) {
 693                         switch (verify_ordered(o_mode, o_name, mode, name,
 694                                                &df_dup_candidates)) {
 695                         case TREE_UNORDERED:
 696                                 not_properly_sorted = 1;
 697                                 break;
 698                         case TREE_HAS_DUPS:
 699                                 has_dup_entries = 1;
 700                                 break;
 701                         default:
 702                                 break;
 703                         }
 704                 }
 705
 706                 o_mode = mode;
 707                 o_name = name;
 708         }
 709
 710         name_stack_clear(&df_dup_candidates);
 711
 712         if (has_null_sha1)
 713                 retval += report(options, tree_oid, OBJ_TREE,
 714                                  FSCK_MSG_NULL_SHA1,
 715                                  "contains entries pointing to null sha1");
 716         if (has_full_path)
 717                 retval += report(options, tree_oid, OBJ_TREE,
 718                                  FSCK_MSG_FULL_PATHNAME,
 719                                  "contains full pathnames");
 720         if (has_empty_name)
 721                 retval += report(options, tree_oid, OBJ_TREE,
 722                                  FSCK_MSG_EMPTY_NAME,
 723                                  "contains empty pathname");
 724         if (has_dot)
 725                 retval += report(options, tree_oid, OBJ_TREE,
 726                                  FSCK_MSG_HAS_DOT,
 727                                  "contains '.'");
 728         if (has_dotdot)
 729                 retval += report(options, tree_oid, OBJ_TREE,
 730                                  FSCK_MSG_HAS_DOTDOT,
 731                                  "contains '..'");
 732         if (has_dotgit)
 733                 retval += report(options, tree_oid, OBJ_TREE,
 734                                  FSCK_MSG_HAS_DOTGIT,
 735                                  "contains '.git'");
 736         if (has_zero_pad)
 737                 retval += report(options, tree_oid, OBJ_TREE,
 738                                  FSCK_MSG_ZERO_PADDED_FILEMODE,
 739                                  "contains zero-padded file modes");
 740         if (has_bad_modes)
 741                 retval += report(options, tree_oid, OBJ_TREE,
 742                                  FSCK_MSG_BAD_FILEMODE,
 743                                  "contains bad file modes");
 744         if (has_dup_entries)
 745                 retval += report(options, tree_oid, OBJ_TREE,
 746                                  FSCK_MSG_DUPLICATE_ENTRIES,
 747                                  "contains duplicate file entries");
 748         if (not_properly_sorted)
 749                 retval += report(options, tree_oid, OBJ_TREE,
 750                                  FSCK_MSG_TREE_NOT_SORTED,
 751                                  "not properly sorted");
 752         return retval;
 753 }
 754
 755 /*
 756  * Confirm that the headers of a commit or tag object end in a reasonable way,
 757  * either with the usual "\n\n" separator, or at least with a trailing newline
 758  * on the final header line.
 759  *
 760  * This property is important for the memory safety of our callers. It allows
 761  * them to scan the buffer linewise without constantly checking the remaining
 762  * size as long as:
 763  *
 764  *   - they check that there are bytes left in the buffer at the start of any
 765  *     line (i.e., that the last newline they saw was not the final one we
 766  *     found here)
 767  *
 768  *   - any intra-line scanning they do will stop at a newline, which will worst
 769  *     case hit the newline we found here as the end-of-header. This makes it
 770  *     OK for them to use helpers like parse_oid_hex(), or even skip_prefix().
 771  */
 772 static int verify_headers(const void *data, unsigned long size,
 773                           const struct object_id *oid, enum object_type type,
 774                           struct fsck_options *options)
 775 {
 776         const char *buffer = (const char *)data;
 777         unsigned long i;
 778
 779         for (i = 0; i < size; i++) {
 780                 switch (buffer[i]) {
 781                 case '\0':
 782                         return report(options, oid, type,
 783                                 FSCK_MSG_NUL_IN_HEADER,
 784                                 "unterminated header: NUL at offset %ld", i);
 785                 case '\n':
 786                         if (i + 1 < size && buffer[i + 1] == '\n')
 787                                 return 0;
 788                 }
 789         }
 790
 791         /*
 792          * We did not find double-LF that separates the header
 793          * and the body.  Not having a body is not a crime but
 794          * we do want to see the terminating LF for the last header
 795          * line.
 796          */
 797         if (size && buffer[size - 1] == '\n')
 798                 return 0;
 799
 800         return report(options, oid, type,
 801                 FSCK_MSG_UNTERMINATED_HEADER, "unterminated header");
 802 }
 803
 804 static int fsck_ident(const char **ident,
 805                       const struct object_id *oid, enum object_type type,
 806                       struct fsck_options *options)
 807 {
 808         const char *p = *ident;
 809         char *end;
 810
 811         *ident = strchrnul(*ident, '\n');
 812         if (**ident == '\n')
 813                 (*ident)++;
 814
 815         if (*p == '<')
 816                 return report(options, oid, type, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 817         p += strcspn(p, "<>\n");
 818         if (*p == '>')
 819                 return report(options, oid, type, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
 820         if (*p != '<')
 821                 return report(options, oid, type, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
 822         if (p[-1] != ' ')
 823                 return report(options, oid, type, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 824         p++;
 825         p += strcspn(p, "<>\n");
 826         if (*p != '>')
 827                 return report(options, oid, type, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
 828         p++;
 829         if (*p != ' ')
 830                 return report(options, oid, type, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
 831         p++;
 832         /*
 833          * Our timestamp parser is based on the C strto*() functions, which
 834          * will happily eat whitespace, including the newline that is supposed
 835          * to prevent us walking past the end of the buffer. So do our own
 836          * scan, skipping linear whitespace but not newlines, and then
 837          * confirming we found a digit. We _could_ be even more strict here,
 838          * as we really expect only a single space, but since we have
 839          * traditionally allowed extra whitespace, we'll continue to do so.
 840          */
 841         while (*p == ' ' || *p == '\t')
 842                 p++;
 843         if (!isdigit(*p))
 844                 return report(options, oid, type, FSCK_MSG_BAD_DATE,
 845                               "invalid author/committer line - bad date");
 846         if (*p == '0' && p[1] != ' ')
 847                 return report(options, oid, type, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
 848         if (date_overflows(parse_timestamp(p, &end, 10)))
 849                 return report(options, oid, type, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
 850         if ((end == p || *end != ' '))
 851                 return report(options, oid, type, FSCK_MSG_BAD_DATE, "invalid author/committer line - bad date");
 852         p = end + 1;
 853         if ((*p != '+' && *p != '-') ||
 854             !isdigit(p[1]) ||
 855             !isdigit(p[2]) ||
 856             !isdigit(p[3]) ||
 857             !isdigit(p[4]) ||
 858             (p[5] != '\n'))
 859                 return report(options, oid, type, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
 860         p += 6;
 861         return 0;
 862 }
 863
 864 static int fsck_commit(const struct object_id *oid,
 865                        const char *buffer, unsigned long size,
 866                        struct fsck_options *options)
 867 {
 868         struct object_id tree_oid, parent_oid;
 869         unsigned author_count;
 870         int err;
 871         const char *buffer_begin = buffer;
 872         const char *buffer_end = buffer + size;
 873         const char *p;
 874
 875         /*
 876          * We _must_ stop parsing immediately if this reports failure, as the
 877          * memory safety of the rest of the function depends on it. See the
 878          * comment above the definition of verify_headers() for more details.
 879          */
 880         if (verify_headers(buffer, size, oid, OBJ_COMMIT, options))
 881                 return -1;
 882
 883         if (buffer >= buffer_end || !skip_prefix(buffer, "tree ", &buffer))
 884                 return report(options, oid, OBJ_COMMIT, FSCK_MSG_MISSING_TREE, "invalid format - expected 'tree' line");
 885         if (parse_oid_hex(buffer, &tree_oid, &p) || *p != '\n') {
 886                 err = report(options, oid, OBJ_COMMIT, FSCK_MSG_BAD_TREE_SHA1, "invalid 'tree' line format - bad sha1");
 887                 if (err)
 888                         return err;
 889         }
 890         buffer = p + 1;
 891         while (buffer < buffer_end && skip_prefix(buffer, "parent ", &buffer)) {
 892                 if (parse_oid_hex(buffer, &parent_oid, &p) || *p != '\n') {
 893                         err = report(options, oid, OBJ_COMMIT, FSCK_MSG_BAD_PARENT_SHA1, "invalid 'parent' line format - bad sha1");
 894                         if (err)
 895                                 return err;
 896                 }
 897                 buffer = p + 1;
 898         }
 899         author_count = 0;
 900         while (buffer < buffer_end && skip_prefix(buffer, "author ", &buffer)) {
 901                 author_count++;
 902                 err = fsck_ident(&buffer, oid, OBJ_COMMIT, options);
 903                 if (err)
 904                         return err;
 905         }
 906         if (author_count < 1)
 907                 err = report(options, oid, OBJ_COMMIT, FSCK_MSG_MISSING_AUTHOR, "invalid format - expected 'author' line");
 908         else if (author_count > 1)
 909                 err = report(options, oid, OBJ_COMMIT, FSCK_MSG_MULTIPLE_AUTHORS, "invalid format - multiple 'author' lines");
 910         if (err)
 911                 return err;
 912         if (buffer >= buffer_end || !skip_prefix(buffer, "committer ", &buffer))
 913                 return report(options, oid, OBJ_COMMIT, FSCK_MSG_MISSING_COMMITTER, "invalid format - expected 'committer' line");
 914         err = fsck_ident(&buffer, oid, OBJ_COMMIT, options);
 915         if (err)
 916                 return err;
 917         if (memchr(buffer_begin, '\0', size)) {
 918                 err = report(options, oid, OBJ_COMMIT, FSCK_MSG_NUL_IN_COMMIT,
 919                              "NUL byte in the commit object body");
 920                 if (err)
 921                         return err;
 922         }
 923         return 0;
 924 }
 925
 926 static int fsck_tag(const struct object_id *oid, const char *buffer,
 927                     unsigned long size, struct fsck_options *options)
 928 {
 929         struct object_id tagged_oid;
 930         int tagged_type;
 931         return fsck_tag_standalone(oid, buffer, size, options, &tagged_oid,
 932                                    &tagged_type);
 933 }
 934
 935 int fsck_tag_standalone(const struct object_id *oid, const char *buffer,
 936                         unsigned long size, struct fsck_options *options,
 937                         struct object_id *tagged_oid,
 938                         int *tagged_type)
 939 {
 940         int ret = 0;
 941         char *eol;
 942         struct strbuf sb = STRBUF_INIT;
 943         const char *buffer_end = buffer + size;
 944         const char *p;
 945
 946         /*
 947          * We _must_ stop parsing immediately if this reports failure, as the
 948          * memory safety of the rest of the function depends on it. See the
 949          * comment above the definition of verify_headers() for more details.
 950          */
 951         ret = verify_headers(buffer, size, oid, OBJ_TAG, options);
 952         if (ret)
 953                 goto done;
 954
 955         if (buffer >= buffer_end || !skip_prefix(buffer, "object ", &buffer)) {
 956                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_OBJECT, "invalid format - expected 'object' line");
 957                 goto done;
 958         }
 959         if (parse_oid_hex(buffer, tagged_oid, &p) || *p != '\n') {
 960                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_BAD_OBJECT_SHA1, "invalid 'object' line format - bad sha1");
 961                 if (ret)
 962                         goto done;
 963         }
 964         buffer = p + 1;
 965
 966         if (buffer >= buffer_end || !skip_prefix(buffer, "type ", &buffer)) {
 967                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_TYPE_ENTRY, "invalid format - expected 'type' line");
 968                 goto done;
 969         }
 970         eol = memchr(buffer, '\n', buffer_end - buffer);
 971         if (!eol) {
 972                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_TYPE, "invalid format - unexpected end after 'type' line");
 973                 goto done;
 974         }
 975         *tagged_type = type_from_string_gently(buffer, eol - buffer, 1);
 976         if (*tagged_type < 0)
 977                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_BAD_TYPE, "invalid 'type' value");
 978         if (ret)
 979                 goto done;
 980         buffer = eol + 1;
 981
 982         if (buffer >= buffer_end || !skip_prefix(buffer, "tag ", &buffer)) {
 983                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_TAG_ENTRY, "invalid format - expected 'tag' line");
 984                 goto done;
 985         }
 986         eol = memchr(buffer, '\n', buffer_end - buffer);
 987         if (!eol) {
 988                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_TAG, "invalid format - unexpected end after 'type' line");
 989                 goto done;
 990         }
 991         strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer);
 992         if (check_refname_format(sb.buf, 0)) {
 993                 ret = report(options, oid, OBJ_TAG,
 994                              FSCK_MSG_BAD_TAG_NAME,
 995                              "invalid 'tag' name: %.*s",
 996                              (int)(eol - buffer), buffer);
 997                 if (ret)
 998                         goto done;
 999         }
1000         buffer = eol + 1;
1001
1002         if (buffer >= buffer_end || !skip_prefix(buffer, "tagger ", &buffer)) {
1003                 /* early tags do not contain 'tagger' lines; warn only */
1004                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
1005                 if (ret)
1006                         goto done;
1007         }
1008         else
1009                 ret = fsck_ident(&buffer, oid, OBJ_TAG, options);
1010
1011         if (buffer < buffer_end && !starts_with(buffer, "\n")) {
1012                 /*
1013                  * The verify_headers() check will allow
1014                  * e.g. "[...]tagger <tagger>\nsome
1015                  * garbage\n\nmessage" to pass, thinking "some
1016                  * garbage" could be a custom header. E.g. "mktag"
1017                  * doesn't want any unknown headers.
1018                  */
1019                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_EXTRA_HEADER_ENTRY, "invalid format - extra header(s) after 'tagger'");
1020                 if (ret)
1021                         goto done;
1022         }
1023
1024 done:
1025         strbuf_release(&sb);
1026         return ret;
1027 }
1028
1029 static int starts_with_dot_slash(const char *const path)
1030 {
1031         return path_match_flags(path, PATH_MATCH_STARTS_WITH_DOT_SLASH |
1032                                 PATH_MATCH_XPLATFORM);
1033 }
1034
1035 static int starts_with_dot_dot_slash(const char *const path)
1036 {
1037         return path_match_flags(path, PATH_MATCH_STARTS_WITH_DOT_DOT_SLASH |
1038                                 PATH_MATCH_XPLATFORM);
1039 }
1040
1041 static int submodule_url_is_relative(const char *url)
1042 {
1043         return starts_with_dot_slash(url) || starts_with_dot_dot_slash(url);
1044 }
1045
1046 /*
1047  * Count directory components that a relative submodule URL should chop
1048  * from the remote_url it is to be resolved against.
1049  *
1050  * In other words, this counts "../" components at the start of a
1051  * submodule URL.
1052  *
1053  * Returns the number of directory components to chop and writes a
1054  * pointer to the next character of url after all leading "./" and
1055  * "../" components to out.
1056  */
1057 static int count_leading_dotdots(const char *url, const char **out)
1058 {
1059         int result = 0;
1060         while (1) {
1061                 if (starts_with_dot_dot_slash(url)) {
1062                         result++;
1063                         url += strlen("../");
1064                         continue;
1065                 }
1066                 if (starts_with_dot_slash(url)) {
1067                         url += strlen("./");
1068                         continue;
1069                 }
1070                 *out = url;
1071                 return result;
1072         }
1073 }
1074 /*
1075  * Check whether a transport is implemented by git-remote-curl.
1076  *
1077  * If it is, returns 1 and writes the URL that would be passed to
1078  * git-remote-curl to the "out" parameter.
1079  *
1080  * Otherwise, returns 0 and leaves "out" untouched.
1081  *
1082  * Examples:
1083  *   http::https://example.com/repo.git -> 1, https://example.com/repo.git
1084  *   https://example.com/repo.git -> 1, https://example.com/repo.git
1085  *   git://example.com/repo.git -> 0
1086  *
1087  * This is for use in checking for previously exploitable bugs that
1088  * required a submodule URL to be passed to git-remote-curl.
1089  */
1090 static int url_to_curl_url(const char *url, const char **out)
1091 {
1092         /*
1093          * We don't need to check for case-aliases, "http.exe", and so
1094          * on because in the default configuration, is_transport_allowed
1095          * prevents URLs with those schemes from being cloned
1096          * automatically.
1097          */
1098         if (skip_prefix(url, "http::", out) ||
1099             skip_prefix(url, "https::", out) ||
1100             skip_prefix(url, "ftp::", out) ||
1101             skip_prefix(url, "ftps::", out))
1102                 return 1;
1103         if (starts_with(url, "http://") ||
1104             starts_with(url, "https://") ||
1105             starts_with(url, "ftp://") ||
1106             starts_with(url, "ftps://")) {
1107                 *out = url;
1108                 return 1;
1109         }
1110         return 0;
1111 }
1112
1113 static int check_submodule_url(const char *url)
1114 {
1115         const char *curl_url;
1116
1117         if (looks_like_command_line_option(url))
1118                 return -1;
1119
1120         if (submodule_url_is_relative(url) || starts_with(url, "git://")) {
1121                 char *decoded;
1122                 const char *next;
1123                 int has_nl;
1124
1125                 /*
1126                  * This could be appended to an http URL and url-decoded;
1127                  * check for malicious characters.
1128                  */
1129                 decoded = url_decode(url);
1130                 has_nl = !!strchr(decoded, '\n');
1131
1132                 free(decoded);
1133                 if (has_nl)
1134                         return -1;
1135
1136                 /*
1137                  * URLs which escape their root via "../" can overwrite
1138                  * the host field and previous components, resolving to
1139                  * URLs like https::example.com/submodule.git and
1140                  * https:///example.com/submodule.git that were
1141                  * susceptible to CVE-2020-11008.
1142                  */
1143                 if (count_leading_dotdots(url, &next) > 0 &&
1144                     (*next == ':' || *next == '/'))
1145                         return -1;
1146         }
1147
1148         else if (url_to_curl_url(url, &curl_url)) {
1149                 struct credential c = CREDENTIAL_INIT;
1150                 int ret = 0;
1151                 if (credential_from_url_gently(&c, curl_url, 1) ||
1152                     !*c.host)
1153                         ret = -1;
1154                 credential_clear(&c);
1155                 return ret;
1156         }
1157
1158         return 0;
1159 }
1160
1161 struct fsck_gitmodules_data {
1162         const struct object_id *oid;
1163         struct fsck_options *options;
1164         int ret;
1165 };
1166
1167 static int fsck_gitmodules_fn(const char *var, const char *value,
1168                               const struct config_context *ctx UNUSED,
1169                               void *vdata)
1170 {
1171         struct fsck_gitmodules_data *data = vdata;
1172         const char *subsection, *key;
1173         size_t subsection_len;
1174         char *name;
1175
1176         if (parse_config_key(var, "submodule", &subsection, &subsection_len, &key) < 0 ||
1177             !subsection)
1178                 return 0;
1179
1180         name = xmemdupz(subsection, subsection_len);
1181         if (check_submodule_name(name) < 0)
1182                 data->ret |= report(data->options,
1183                                     data->oid, OBJ_BLOB,
1184                                     FSCK_MSG_GITMODULES_NAME,
1185                                     "disallowed submodule name: %s",
1186                                     name);
1187         if (!strcmp(key, "url") && value &&
1188             check_submodule_url(value) < 0)
1189                 data->ret |= report(data->options,
1190                                     data->oid, OBJ_BLOB,
1191                                     FSCK_MSG_GITMODULES_URL,
1192                                     "disallowed submodule url: %s",
1193                                     value);
1194         if (!strcmp(key, "path") && value &&
1195             looks_like_command_line_option(value))
1196                 data->ret |= report(data->options,
1197                                     data->oid, OBJ_BLOB,
1198                                     FSCK_MSG_GITMODULES_PATH,
1199                                     "disallowed submodule path: %s",
1200                                     value);
1201         if (!strcmp(key, "update") && value &&
1202             parse_submodule_update_type(value) == SM_UPDATE_COMMAND)
1203                 data->ret |= report(data->options, data->oid, OBJ_BLOB,
1204                                     FSCK_MSG_GITMODULES_UPDATE,
1205                                     "disallowed submodule update setting: %s",
1206                                     value);
1207         free(name);
1208
1209         return 0;
1210 }
1211
1212 static int fsck_blob(const struct object_id *oid, const char *buf,
1213                      unsigned long size, struct fsck_options *options)
1214 {
1215         int ret = 0;
1216
1217         if (object_on_skiplist(options, oid))
1218                 return 0;
1219
1220         if (oidset_contains(&options->gitmodules_found, oid)) {
1221                 struct config_options config_opts = { 0 };
1222                 struct fsck_gitmodules_data data;
1223
1224                 oidset_insert(&options->gitmodules_done, oid);
1225
1226                 if (!buf) {
1227                         /*
1228                          * A missing buffer here is a sign that the caller found the
1229                          * blob too gigantic to load into memory. Let's just consider
1230                          * that an error.
1231                          */
1232                         return report(options, oid, OBJ_BLOB,
1233                                         FSCK_MSG_GITMODULES_LARGE,
1234                                         ".gitmodules too large to parse");
1235                 }
1236
1237                 data.oid = oid;
1238                 data.options = options;
1239                 data.ret = 0;
1240                 config_opts.error_action = CONFIG_ERROR_SILENT;
1241                 if (git_config_from_mem(fsck_gitmodules_fn, CONFIG_ORIGIN_BLOB,
1242                                         ".gitmodules", buf, size, &data,
1243                                         CONFIG_SCOPE_UNKNOWN, &config_opts))
1244                         data.ret |= report(options, oid, OBJ_BLOB,
1245                                         FSCK_MSG_GITMODULES_PARSE,
1246                                         "could not parse gitmodules blob");
1247                 ret |= data.ret;
1248         }
1249
1250         if (oidset_contains(&options->gitattributes_found, oid)) {
1251                 const char *ptr;
1252
1253                 oidset_insert(&options->gitattributes_done, oid);
1254
1255                 if (!buf || size > ATTR_MAX_FILE_SIZE) {
1256                         /*
1257                          * A missing buffer here is a sign that the caller found the
1258                          * blob too gigantic to load into memory. Let's just consider
1259                          * that an error.
1260                          */
1261                         return report(options, oid, OBJ_BLOB,
1262                                         FSCK_MSG_GITATTRIBUTES_LARGE,
1263                                         ".gitattributes too large to parse");
1264                 }
1265
1266                 for (ptr = buf; *ptr; ) {
1267                         const char *eol = strchrnul(ptr, '\n');
1268                         if (eol - ptr >= ATTR_MAX_LINE_LENGTH) {
1269                                 ret |= report(options, oid, OBJ_BLOB,
1270                                               FSCK_MSG_GITATTRIBUTES_LINE_LENGTH,
1271                                               ".gitattributes has too long lines to parse");
1272                                 break;
1273                         }
1274
1275                         ptr = *eol ? eol + 1 : eol;
1276                 }
1277         }
1278
1279         return ret;
1280 }
1281
1282 int fsck_object(struct object *obj, void *data, unsigned long size,
1283         struct fsck_options *options)
1284 {
1285         if (!obj)
1286                 return report(options, NULL, OBJ_NONE, FSCK_MSG_BAD_OBJECT_SHA1, "no valid object to fsck");
1287
1288         return fsck_buffer(&obj->oid, obj->type, data, size, options);
1289 }
1290
1291 int fsck_buffer(const struct object_id *oid, enum object_type type,
1292                 void *data, unsigned long size,
1293                 struct fsck_options *options)
1294 {
1295         if (type == OBJ_BLOB)
1296                 return fsck_blob(oid, data, size, options);
1297         if (type == OBJ_TREE)
1298                 return fsck_tree(oid, data, size, options);
1299         if (type == OBJ_COMMIT)
1300                 return fsck_commit(oid, data, size, options);
1301         if (type == OBJ_TAG)
1302                 return fsck_tag(oid, data, size, options);
1303
1304         return report(options, oid, type,
1305                       FSCK_MSG_UNKNOWN_TYPE,
1306                       "unknown type '%d' (internal fsck error)",
1307                       type);
1308 }
1309
1310 int fsck_error_function(struct fsck_options *o,
1311                         const struct object_id *oid,
1312                         enum object_type object_type,
1313                         enum fsck_msg_type msg_type,
1314                         enum fsck_msg_id msg_id,
1315                         const char *message)
1316 {
1317         if (msg_type == FSCK_WARN) {
1318                 warning("object %s: %s", fsck_describe_object(o, oid), message);
1319                 return 0;
1320         }
1321         error("object %s: %s", fsck_describe_object(o, oid), message);
1322         return 1;
1323 }
1324
1325 static int fsck_blobs(struct oidset *blobs_found, struct oidset *blobs_done,
1326                       enum fsck_msg_id msg_missing, enum fsck_msg_id msg_type,
1327                       struct fsck_options *options, const char *blob_type)
1328 {
1329         int ret = 0;
1330         struct oidset_iter iter;
1331         const struct object_id *oid;
1332
1333         oidset_iter_init(blobs_found, &iter);
1334         while ((oid = oidset_iter_next(&iter))) {
1335                 enum object_type type;
1336                 unsigned long size;
1337                 char *buf;
1338
1339                 if (oidset_contains(blobs_done, oid))
1340                         continue;
1341
1342                 buf = repo_read_object_file(the_repository, oid, &type, &size);
1343                 if (!buf) {
1344                         if (is_promisor_object(oid))
1345                                 continue;
1346                         ret |= report(options,
1347                                       oid, OBJ_BLOB, msg_missing,
1348                                       "unable to read %s blob", blob_type);
1349                         continue;
1350                 }
1351
1352                 if (type == OBJ_BLOB)
1353                         ret |= fsck_blob(oid, buf, size, options);
1354                 else
1355                         ret |= report(options, oid, type, msg_type,
1356                                       "non-blob found at %s", blob_type);
1357                 free(buf);
1358         }
1359
1360         oidset_clear(blobs_found);
1361         oidset_clear(blobs_done);
1362
1363         return ret;
1364 }
1365
1366 int fsck_finish(struct fsck_options *options)
1367 {
1368         int ret = 0;
1369
1370         ret |= fsck_blobs(&options->gitmodules_found, &options->gitmodules_done,
1371                           FSCK_MSG_GITMODULES_MISSING, FSCK_MSG_GITMODULES_BLOB,
1372                           options, ".gitmodules");
1373         ret |= fsck_blobs(&options->gitattributes_found, &options->gitattributes_done,
1374                           FSCK_MSG_GITATTRIBUTES_MISSING, FSCK_MSG_GITATTRIBUTES_BLOB,
1375                           options, ".gitattributes");
1376
1377         return ret;
1378 }
1379
1380 int git_fsck_config(const char *var, const char *value,
1381                     const struct config_context *ctx, void *cb)
1382 {
1383         struct fsck_options *options = cb;
1384         if (strcmp(var, "fsck.skiplist") == 0) {
1385                 const char *path;
1386                 struct strbuf sb = STRBUF_INIT;
1387
1388                 if (git_config_pathname(&path, var, value))
1389                         return 1;
1390                 strbuf_addf(&sb, "skiplist=%s", path);
1391                 free((char *)path);
1392                 fsck_set_msg_types(options, sb.buf);
1393                 strbuf_release(&sb);
1394                 return 0;
1395         }
1396
1397         if (skip_prefix(var, "fsck.", &var)) {
1398                 fsck_set_msg_type(options, var, value);
1399                 return 0;
1400         }
1401
1402         return git_default_config(var, value, ctx, cb);
1403 }
1404
1405 /*
1406  * Custom error callbacks that are used in more than one place.
1407  */
1408
1409 int fsck_error_cb_print_missing_gitmodules(struct fsck_options *o,
1410                                            const struct object_id *oid,
1411                                            enum object_type object_type,
1412                                            enum fsck_msg_type msg_type,
1413                                            enum fsck_msg_id msg_id,
1414                                            const char *message)
1415 {
1416         if (msg_id == FSCK_MSG_GITMODULES_MISSING) {
1417                 puts(oid_to_hex(oid));
1418                 return 0;
1419         }
1420         return fsck_error_function(o, oid, object_type, msg_type, msg_id, message);
1421 }