fsck.c

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