fsck.c

   1 #include "cache.h"
   2 #include "object-store.h"
   3 #include "repository.h"
   4 #include "object.h"
   5 #include "blob.h"
   6 #include "tree.h"
   7 #include "tree-walk.h"
   8 #include "commit.h"
   9 #include "tag.h"
  10 #include "fsck.h"
  11 #include "refs.h"
  12 #include "utf8.h"
  13 #include "decorate.h"
  14 #include "oidset.h"
  15 #include "packfile.h"
  16 #include "submodule-config.h"
  17 #include "config.h"
  18 #include "help.h"
  19
  20 static struct oidset gitmodules_found = OIDSET_INIT;
  21 static struct oidset gitmodules_done = OIDSET_INIT;
  22
  23 #define FSCK_FATAL -1
  24 #define FSCK_INFO -2
  25
  26 #define FOREACH_MSG_ID(FUNC) \
  27         /* fatal errors */ \
  28         FUNC(NUL_IN_HEADER, FATAL) \
  29         FUNC(UNTERMINATED_HEADER, FATAL) \
  30         /* errors */ \
  31         FUNC(BAD_DATE, ERROR) \
  32         FUNC(BAD_DATE_OVERFLOW, ERROR) \
  33         FUNC(BAD_EMAIL, ERROR) \
  34         FUNC(BAD_NAME, ERROR) \
  35         FUNC(BAD_OBJECT_SHA1, ERROR) \
  36         FUNC(BAD_PARENT_SHA1, ERROR) \
  37         FUNC(BAD_TAG_OBJECT, ERROR) \
  38         FUNC(BAD_TIMEZONE, ERROR) \
  39         FUNC(BAD_TREE, ERROR) \
  40         FUNC(BAD_TREE_SHA1, ERROR) \
  41         FUNC(BAD_TYPE, ERROR) \
  42         FUNC(DUPLICATE_ENTRIES, ERROR) \
  43         FUNC(MISSING_AUTHOR, ERROR) \
  44         FUNC(MISSING_COMMITTER, ERROR) \
  45         FUNC(MISSING_EMAIL, ERROR) \
  46         FUNC(MISSING_GRAFT, ERROR) \
  47         FUNC(MISSING_NAME_BEFORE_EMAIL, ERROR) \
  48         FUNC(MISSING_OBJECT, ERROR) \
  49         FUNC(MISSING_PARENT, ERROR) \
  50         FUNC(MISSING_SPACE_BEFORE_DATE, ERROR) \
  51         FUNC(MISSING_SPACE_BEFORE_EMAIL, ERROR) \
  52         FUNC(MISSING_TAG, ERROR) \
  53         FUNC(MISSING_TAG_ENTRY, ERROR) \
  54         FUNC(MISSING_TAG_OBJECT, ERROR) \
  55         FUNC(MISSING_TREE, ERROR) \
  56         FUNC(MISSING_TREE_OBJECT, ERROR) \
  57         FUNC(MISSING_TYPE, ERROR) \
  58         FUNC(MISSING_TYPE_ENTRY, ERROR) \
  59         FUNC(MULTIPLE_AUTHORS, ERROR) \
  60         FUNC(TAG_OBJECT_NOT_TAG, ERROR) \
  61         FUNC(TREE_NOT_SORTED, ERROR) \
  62         FUNC(UNKNOWN_TYPE, ERROR) \
  63         FUNC(ZERO_PADDED_DATE, ERROR) \
  64         FUNC(GITMODULES_MISSING, ERROR) \
  65         FUNC(GITMODULES_BLOB, ERROR) \
  66         FUNC(GITMODULES_LARGE, ERROR) \
  67         FUNC(GITMODULES_NAME, ERROR) \
  68         FUNC(GITMODULES_SYMLINK, ERROR) \
  69         FUNC(GITMODULES_URL, ERROR) \
  70         FUNC(GITMODULES_PATH, ERROR) \
  71         /* warnings */ \
  72         FUNC(BAD_FILEMODE, WARN) \
  73         FUNC(EMPTY_NAME, WARN) \
  74         FUNC(FULL_PATHNAME, WARN) \
  75         FUNC(HAS_DOT, WARN) \
  76         FUNC(HAS_DOTDOT, WARN) \
  77         FUNC(HAS_DOTGIT, WARN) \
  78         FUNC(NULL_SHA1, WARN) \
  79         FUNC(ZERO_PADDED_FILEMODE, WARN) \
  80         FUNC(NUL_IN_COMMIT, WARN) \
  81         /* infos (reported as warnings, but ignored by default) */ \
  82         FUNC(GITMODULES_PARSE, INFO) \
  83         FUNC(BAD_TAG_NAME, INFO) \
  84         FUNC(MISSING_TAGGER_ENTRY, INFO)
  85
  86 #define MSG_ID(id, msg_type) FSCK_MSG_##id,
  87 enum fsck_msg_id {
  88         FOREACH_MSG_ID(MSG_ID)
  89         FSCK_MSG_MAX
  90 };
  91 #undef MSG_ID
  92
  93 #define STR(x) #x
  94 #define MSG_ID(id, msg_type) { STR(id), NULL, NULL, FSCK_##msg_type },
  95 static struct {
  96         const char *id_string;
  97         const char *downcased;
  98         const char *camelcased;
  99         int msg_type;
 100 } msg_id_info[FSCK_MSG_MAX + 1] = {
 101         FOREACH_MSG_ID(MSG_ID)
 102         { NULL, NULL, NULL, -1 }
 103 };
 104 #undef MSG_ID
 105
 106 static void prepare_msg_ids(void)
 107 {
 108         int i;
 109
 110         if (msg_id_info[0].downcased)
 111                 return;
 112
 113         /* convert id_string to lower case, without underscores. */
 114         for (i = 0; i < FSCK_MSG_MAX; i++) {
 115                 const char *p = msg_id_info[i].id_string;
 116                 int len = strlen(p);
 117                 char *q = xmalloc(len);
 118
 119                 msg_id_info[i].downcased = q;
 120                 while (*p)
 121                         if (*p == '_')
 122                                 p++;
 123                         else
 124                                 *(q)++ = tolower(*(p)++);
 125                 *q = '\0';
 126
 127                 p = msg_id_info[i].id_string;
 128                 q = xmalloc(len);
 129                 msg_id_info[i].camelcased = q;
 130                 while (*p) {
 131                         if (*p == '_') {
 132                                 p++;
 133                                 if (*p)
 134                                         *q++ = *p++;
 135                         } else {
 136                                 *q++ = tolower(*p++);
 137                         }
 138                 }
 139                 *q = '\0';
 140         }
 141 }
 142
 143 static int parse_msg_id(const char *text)
 144 {
 145         int i;
 146
 147         prepare_msg_ids();
 148
 149         for (i = 0; i < FSCK_MSG_MAX; i++)
 150                 if (!strcmp(text, msg_id_info[i].downcased))
 151                         return i;
 152
 153         return -1;
 154 }
 155
 156 void list_config_fsck_msg_ids(struct string_list *list, const char *prefix)
 157 {
 158         int i;
 159
 160         prepare_msg_ids();
 161
 162         for (i = 0; i < FSCK_MSG_MAX; i++)
 163                 list_config_item(list, prefix, msg_id_info[i].camelcased);
 164 }
 165
 166 static int fsck_msg_type(enum fsck_msg_id msg_id,
 167         struct fsck_options *options)
 168 {
 169         int msg_type;
 170
 171         assert(msg_id >= 0 && msg_id < FSCK_MSG_MAX);
 172
 173         if (options->msg_type)
 174                 msg_type = options->msg_type[msg_id];
 175         else {
 176                 msg_type = msg_id_info[msg_id].msg_type;
 177                 if (options->strict && msg_type == FSCK_WARN)
 178                         msg_type = FSCK_ERROR;
 179         }
 180
 181         return msg_type;
 182 }
 183
 184 static int parse_msg_type(const char *str)
 185 {
 186         if (!strcmp(str, "error"))
 187                 return FSCK_ERROR;
 188         else if (!strcmp(str, "warn"))
 189                 return FSCK_WARN;
 190         else if (!strcmp(str, "ignore"))
 191                 return FSCK_IGNORE;
 192         else
 193                 die("Unknown fsck message type: '%s'", str);
 194 }
 195
 196 int is_valid_msg_type(const char *msg_id, const char *msg_type)
 197 {
 198         if (parse_msg_id(msg_id) < 0)
 199                 return 0;
 200         parse_msg_type(msg_type);
 201         return 1;
 202 }
 203
 204 void fsck_set_msg_type(struct fsck_options *options,
 205                 const char *msg_id, const char *msg_type)
 206 {
 207         int id = parse_msg_id(msg_id), type;
 208
 209         if (id < 0)
 210                 die("Unhandled message id: %s", msg_id);
 211         type = parse_msg_type(msg_type);
 212
 213         if (type != FSCK_ERROR && msg_id_info[id].msg_type == FSCK_FATAL)
 214                 die("Cannot demote %s to %s", msg_id, msg_type);
 215
 216         if (!options->msg_type) {
 217                 int i;
 218                 int *msg_type;
 219                 ALLOC_ARRAY(msg_type, FSCK_MSG_MAX);
 220                 for (i = 0; i < FSCK_MSG_MAX; i++)
 221                         msg_type[i] = fsck_msg_type(i, options);
 222                 options->msg_type = msg_type;
 223         }
 224
 225         options->msg_type[id] = type;
 226 }
 227
 228 void fsck_set_msg_types(struct fsck_options *options, const char *values)
 229 {
 230         char *buf = xstrdup(values), *to_free = buf;
 231         int done = 0;
 232
 233         while (!done) {
 234                 int len = strcspn(buf, " ,|"), equal;
 235
 236                 done = !buf[len];
 237                 if (!len) {
 238                         buf++;
 239                         continue;
 240                 }
 241                 buf[len] = '\0';
 242
 243                 for (equal = 0;
 244                      equal < len && buf[equal] != '=' && buf[equal] != ':';
 245                      equal++)
 246                         buf[equal] = tolower(buf[equal]);
 247                 buf[equal] = '\0';
 248
 249                 if (!strcmp(buf, "skiplist")) {
 250                         if (equal == len)
 251                                 die("skiplist requires a path");
 252                         oidset_parse_file(&options->skiplist, buf + equal + 1);
 253                         buf += len + 1;
 254                         continue;
 255                 }
 256
 257                 if (equal == len)
 258                         die("Missing '=': '%s'", buf);
 259
 260                 fsck_set_msg_type(options, buf, buf + equal + 1);
 261                 buf += len + 1;
 262         }
 263         free(to_free);
 264 }
 265
 266 static void append_msg_id(struct strbuf *sb, const char *msg_id)
 267 {
 268         for (;;) {
 269                 char c = *(msg_id)++;
 270
 271                 if (!c)
 272                         break;
 273                 if (c != '_')
 274                         strbuf_addch(sb, tolower(c));
 275                 else {
 276                         assert(*msg_id);
 277                         strbuf_addch(sb, *(msg_id)++);
 278                 }
 279         }
 280
 281         strbuf_addstr(sb, ": ");
 282 }
 283
 284 static int object_on_skiplist(struct fsck_options *opts, struct object *obj)
 285 {
 286         return opts && obj && oidset_contains(&opts->skiplist, &obj->oid);
 287 }
 288
 289 __attribute__((format (printf, 4, 5)))
 290 static int report(struct fsck_options *options, struct object *object,
 291         enum fsck_msg_id id, const char *fmt, ...)
 292 {
 293         va_list ap;
 294         struct strbuf sb = STRBUF_INIT;
 295         int msg_type = fsck_msg_type(id, options), result;
 296
 297         if (msg_type == FSCK_IGNORE)
 298                 return 0;
 299
 300         if (object_on_skiplist(options, object))
 301                 return 0;
 302
 303         if (msg_type == FSCK_FATAL)
 304                 msg_type = FSCK_ERROR;
 305         else if (msg_type == FSCK_INFO)
 306                 msg_type = FSCK_WARN;
 307
 308         append_msg_id(&sb, msg_id_info[id].id_string);
 309
 310         va_start(ap, fmt);
 311         strbuf_vaddf(&sb, fmt, ap);
 312         result = options->error_func(options, object, msg_type, sb.buf);
 313         strbuf_release(&sb);
 314         va_end(ap);
 315
 316         return result;
 317 }
 318
 319 static char *get_object_name(struct fsck_options *options, struct object *obj)
 320 {
 321         if (!options->object_names)
 322                 return NULL;
 323         return lookup_decoration(options->object_names, obj);
 324 }
 325
 326 static void put_object_name(struct fsck_options *options, struct object *obj,
 327         const char *fmt, ...)
 328 {
 329         va_list ap;
 330         struct strbuf buf = STRBUF_INIT;
 331         char *existing;
 332
 333         if (!options->object_names)
 334                 return;
 335         existing = lookup_decoration(options->object_names, obj);
 336         if (existing)
 337                 return;
 338         va_start(ap, fmt);
 339         strbuf_vaddf(&buf, fmt, ap);
 340         add_decoration(options->object_names, obj, strbuf_detach(&buf, NULL));
 341         va_end(ap);
 342 }
 343
 344 static const char *describe_object(struct fsck_options *o, struct object *obj)
 345 {
 346         static struct strbuf buf = STRBUF_INIT;
 347         char *name;
 348
 349         strbuf_reset(&buf);
 350         strbuf_addstr(&buf, oid_to_hex(&obj->oid));
 351         if (o->object_names && (name = lookup_decoration(o->object_names, obj)))
 352                 strbuf_addf(&buf, " (%s)", name);
 353
 354         return buf.buf;
 355 }
 356
 357 static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *options)
 358 {
 359         struct tree_desc desc;
 360         struct name_entry entry;
 361         int res = 0;
 362         const char *name;
 363
 364         if (parse_tree(tree))
 365                 return -1;
 366
 367         name = get_object_name(options, &tree->object);
 368         if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
 369                 return -1;
 370         while (tree_entry_gently(&desc, &entry)) {
 371                 struct object *obj;
 372                 int result;
 373
 374                 if (S_ISGITLINK(entry.mode))
 375                         continue;
 376
 377                 if (S_ISDIR(entry.mode)) {
 378                         obj = (struct object *)lookup_tree(the_repository, &entry.oid);
 379                         if (name && obj)
 380                                 put_object_name(options, obj, "%s%s/", name,
 381                                         entry.path);
 382                         result = options->walk(obj, OBJ_TREE, data, options);
 383                 }
 384                 else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode)) {
 385                         obj = (struct object *)lookup_blob(the_repository, &entry.oid);
 386                         if (name && obj)
 387                                 put_object_name(options, obj, "%s%s", name,
 388                                         entry.path);
 389                         result = options->walk(obj, OBJ_BLOB, data, options);
 390                 }
 391                 else {
 392                         result = error("in tree %s: entry %s has bad mode %.6o",
 393                                         describe_object(options, &tree->object), entry.path, entry.mode);
 394                 }
 395                 if (result < 0)
 396                         return result;
 397                 if (!res)
 398                         res = result;
 399         }
 400         return res;
 401 }
 402
 403 static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_options *options)
 404 {
 405         int counter = 0, generation = 0, name_prefix_len = 0;
 406         struct commit_list *parents;
 407         int res;
 408         int result;
 409         const char *name;
 410
 411         if (parse_commit(commit))
 412                 return -1;
 413
 414         name = get_object_name(options, &commit->object);
 415         if (name)
 416                 put_object_name(options, &get_commit_tree(commit)->object,
 417                                 "%s:", name);
 418
 419         result = options->walk((struct object *)get_commit_tree(commit),
 420                                OBJ_TREE, data, options);
 421         if (result < 0)
 422                 return result;
 423         res = result;
 424
 425         parents = commit->parents;
 426         if (name && parents) {
 427                 int len = strlen(name), power;
 428
 429                 if (len && name[len - 1] == '^') {
 430                         generation = 1;
 431                         name_prefix_len = len - 1;
 432                 }
 433                 else { /* parse ~<generation> suffix */
 434                         for (generation = 0, power = 1;
 435                              len && isdigit(name[len - 1]);
 436                              power *= 10)
 437                                 generation += power * (name[--len] - '0');
 438                         if (power > 1 && len && name[len - 1] == '~')
 439                                 name_prefix_len = len - 1;
 440                 }
 441         }
 442
 443         while (parents) {
 444                 if (name) {
 445                         struct object *obj = &parents->item->object;
 446
 447                         if (counter++)
 448                                 put_object_name(options, obj, "%s^%d",
 449                                         name, counter);
 450                         else if (generation > 0)
 451                                 put_object_name(options, obj, "%.*s~%d",
 452                                         name_prefix_len, name, generation + 1);
 453                         else
 454                                 put_object_name(options, obj, "%s^", name);
 455                 }
 456                 result = options->walk((struct object *)parents->item, OBJ_COMMIT, data, options);
 457                 if (result < 0)
 458                         return result;
 459                 if (!res)
 460                         res = result;
 461                 parents = parents->next;
 462         }
 463         return res;
 464 }
 465
 466 static int fsck_walk_tag(struct tag *tag, void *data, struct fsck_options *options)
 467 {
 468         char *name = get_object_name(options, &tag->object);
 469
 470         if (parse_tag(tag))
 471                 return -1;
 472         if (name)
 473                 put_object_name(options, tag->tagged, "%s", name);
 474         return options->walk(tag->tagged, OBJ_ANY, data, options);
 475 }
 476
 477 int fsck_walk(struct object *obj, void *data, struct fsck_options *options)
 478 {
 479         if (!obj)
 480                 return -1;
 481
 482         if (obj->type == OBJ_NONE)
 483                 parse_object(the_repository, &obj->oid);
 484
 485         switch (obj->type) {
 486         case OBJ_BLOB:
 487                 return 0;
 488         case OBJ_TREE:
 489                 return fsck_walk_tree((struct tree *)obj, data, options);
 490         case OBJ_COMMIT:
 491                 return fsck_walk_commit((struct commit *)obj, data, options);
 492         case OBJ_TAG:
 493                 return fsck_walk_tag((struct tag *)obj, data, options);
 494         default:
 495                 error("Unknown object type for %s", describe_object(options, obj));
 496                 return -1;
 497         }
 498 }
 499
 500 /*
 501  * The entries in a tree are ordered in the _path_ order,
 502  * which means that a directory entry is ordered by adding
 503  * a slash to the end of it.
 504  *
 505  * So a directory called "a" is ordered _after_ a file
 506  * called "a.c", because "a/" sorts after "a.c".
 507  */
 508 #define TREE_UNORDERED (-1)
 509 #define TREE_HAS_DUPS  (-2)
 510
 511 static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
 512 {
 513         int len1 = strlen(name1);
 514         int len2 = strlen(name2);
 515         int len = len1 < len2 ? len1 : len2;
 516         unsigned char c1, c2;
 517         int cmp;
 518
 519         cmp = memcmp(name1, name2, len);
 520         if (cmp < 0)
 521                 return 0;
 522         if (cmp > 0)
 523                 return TREE_UNORDERED;
 524
 525         /*
 526          * Ok, the first <len> characters are the same.
 527          * Now we need to order the next one, but turn
 528          * a '\0' into a '/' for a directory entry.
 529          */
 530         c1 = name1[len];
 531         c2 = name2[len];
 532         if (!c1 && !c2)
 533                 /*
 534                  * git-write-tree used to write out a nonsense tree that has
 535                  * entries with the same name, one blob and one tree.  Make
 536                  * sure we do not have duplicate entries.
 537                  */
 538                 return TREE_HAS_DUPS;
 539         if (!c1 && S_ISDIR(mode1))
 540                 c1 = '/';
 541         if (!c2 && S_ISDIR(mode2))
 542                 c2 = '/';
 543         return c1 < c2 ? 0 : TREE_UNORDERED;
 544 }
 545
 546 static int fsck_tree(struct tree *item, struct fsck_options *options)
 547 {
 548         int retval = 0;
 549         int has_null_sha1 = 0;
 550         int has_full_path = 0;
 551         int has_empty_name = 0;
 552         int has_dot = 0;
 553         int has_dotdot = 0;
 554         int has_dotgit = 0;
 555         int has_zero_pad = 0;
 556         int has_bad_modes = 0;
 557         int has_dup_entries = 0;
 558         int not_properly_sorted = 0;
 559         struct tree_desc desc;
 560         unsigned o_mode;
 561         const char *o_name;
 562
 563         if (init_tree_desc_gently(&desc, item->buffer, item->size)) {
 564                 retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
 565                 return retval;
 566         }
 567
 568         o_mode = 0;
 569         o_name = NULL;
 570
 571         while (desc.size) {
 572                 unsigned short mode;
 573                 const char *name;
 574                 const struct object_id *oid;
 575
 576                 oid = tree_entry_extract(&desc, &name, &mode);
 577
 578                 has_null_sha1 |= is_null_oid(oid);
 579                 has_full_path |= !!strchr(name, '/');
 580                 has_empty_name |= !*name;
 581                 has_dot |= !strcmp(name, ".");
 582                 has_dotdot |= !strcmp(name, "..");
 583                 has_dotgit |= is_hfs_dotgit(name) || is_ntfs_dotgit(name);
 584                 has_zero_pad |= *(char *)desc.buffer == '0';
 585
 586                 if (is_hfs_dotgitmodules(name) || is_ntfs_dotgitmodules(name)) {
 587                         if (!S_ISLNK(mode))
 588                                 oidset_insert(&gitmodules_found, oid);
 589                         else
 590                                 retval += report(options, &item->object,
 591                                                  FSCK_MSG_GITMODULES_SYMLINK,
 592                                                  ".gitmodules is a symbolic link");
 593                 }
 594
 595                 if (update_tree_entry_gently(&desc)) {
 596                         retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
 597                         break;
 598                 }
 599
 600                 switch (mode) {
 601                 /*
 602                  * Standard modes..
 603                  */
 604                 case S_IFREG | 0755:
 605                 case S_IFREG | 0644:
 606                 case S_IFLNK:
 607                 case S_IFDIR:
 608                 case S_IFGITLINK:
 609                         break;
 610                 /*
 611                  * This is nonstandard, but we had a few of these
 612                  * early on when we honored the full set of mode
 613                  * bits..
 614                  */
 615                 case S_IFREG | 0664:
 616                         if (!options->strict)
 617                                 break;
 618                         /* fallthrough */
 619                 default:
 620                         has_bad_modes = 1;
 621                 }
 622
 623                 if (o_name) {
 624                         switch (verify_ordered(o_mode, o_name, mode, name)) {
 625                         case TREE_UNORDERED:
 626                                 not_properly_sorted = 1;
 627                                 break;
 628                         case TREE_HAS_DUPS:
 629                                 has_dup_entries = 1;
 630                                 break;
 631                         default:
 632                                 break;
 633                         }
 634                 }
 635
 636                 o_mode = mode;
 637                 o_name = name;
 638         }
 639
 640         if (has_null_sha1)
 641                 retval += report(options, &item->object, FSCK_MSG_NULL_SHA1, "contains entries pointing to null sha1");
 642         if (has_full_path)
 643                 retval += report(options, &item->object, FSCK_MSG_FULL_PATHNAME, "contains full pathnames");
 644         if (has_empty_name)
 645                 retval += report(options, &item->object, FSCK_MSG_EMPTY_NAME, "contains empty pathname");
 646         if (has_dot)
 647                 retval += report(options, &item->object, FSCK_MSG_HAS_DOT, "contains '.'");
 648         if (has_dotdot)
 649                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTDOT, "contains '..'");
 650         if (has_dotgit)
 651                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTGIT, "contains '.git'");
 652         if (has_zero_pad)
 653                 retval += report(options, &item->object, FSCK_MSG_ZERO_PADDED_FILEMODE, "contains zero-padded file modes");
 654         if (has_bad_modes)
 655                 retval += report(options, &item->object, FSCK_MSG_BAD_FILEMODE, "contains bad file modes");
 656         if (has_dup_entries)
 657                 retval += report(options, &item->object, FSCK_MSG_DUPLICATE_ENTRIES, "contains duplicate file entries");
 658         if (not_properly_sorted)
 659                 retval += report(options, &item->object, FSCK_MSG_TREE_NOT_SORTED, "not properly sorted");
 660         return retval;
 661 }
 662
 663 static int verify_headers(const void *data, unsigned long size,
 664                           struct object *obj, struct fsck_options *options)
 665 {
 666         const char *buffer = (const char *)data;
 667         unsigned long i;
 668
 669         for (i = 0; i < size; i++) {
 670                 switch (buffer[i]) {
 671                 case '\0':
 672                         return report(options, obj,
 673                                 FSCK_MSG_NUL_IN_HEADER,
 674                                 "unterminated header: NUL at offset %ld", i);
 675                 case '\n':
 676                         if (i + 1 < size && buffer[i + 1] == '\n')
 677                                 return 0;
 678                 }
 679         }
 680
 681         /*
 682          * We did not find double-LF that separates the header
 683          * and the body.  Not having a body is not a crime but
 684          * we do want to see the terminating LF for the last header
 685          * line.
 686          */
 687         if (size && buffer[size - 1] == '\n')
 688                 return 0;
 689
 690         return report(options, obj,
 691                 FSCK_MSG_UNTERMINATED_HEADER, "unterminated header");
 692 }
 693
 694 static int fsck_ident(const char **ident, struct object *obj, struct fsck_options *options)
 695 {
 696         const char *p = *ident;
 697         char *end;
 698
 699         *ident = strchrnul(*ident, '\n');
 700         if (**ident == '\n')
 701                 (*ident)++;
 702
 703         if (*p == '<')
 704                 return report(options, obj, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 705         p += strcspn(p, "<>\n");
 706         if (*p == '>')
 707                 return report(options, obj, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
 708         if (*p != '<')
 709                 return report(options, obj, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
 710         if (p[-1] != ' ')
 711                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 712         p++;
 713         p += strcspn(p, "<>\n");
 714         if (*p != '>')
 715                 return report(options, obj, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
 716         p++;
 717         if (*p != ' ')
 718                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
 719         p++;
 720         if (*p == '0' && p[1] != ' ')
 721                 return report(options, obj, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
 722         if (date_overflows(parse_timestamp(p, &end, 10)))
 723                 return report(options, obj, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
 724         if ((end == p || *end != ' '))
 725                 return report(options, obj, FSCK_MSG_BAD_DATE, "invalid author/committer line - bad date");
 726         p = end + 1;
 727         if ((*p != '+' && *p != '-') ||
 728             !isdigit(p[1]) ||
 729             !isdigit(p[2]) ||
 730             !isdigit(p[3]) ||
 731             !isdigit(p[4]) ||
 732             (p[5] != '\n'))
 733                 return report(options, obj, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
 734         p += 6;
 735         return 0;
 736 }
 737
 738 static int fsck_commit_buffer(struct commit *commit, const char *buffer,
 739         unsigned long size, struct fsck_options *options)
 740 {
 741         struct object_id tree_oid, oid;
 742         struct commit_graft *graft;
 743         unsigned parent_count, parent_line_count = 0, author_count;
 744         int err;
 745         const char *buffer_begin = buffer;
 746         const char *p;
 747
 748         if (verify_headers(buffer, size, &commit->object, options))
 749                 return -1;
 750
 751         if (!skip_prefix(buffer, "tree ", &buffer))
 752                 return report(options, &commit->object, FSCK_MSG_MISSING_TREE, "invalid format - expected 'tree' line");
 753         if (parse_oid_hex(buffer, &tree_oid, &p) || *p != '\n') {
 754                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE_SHA1, "invalid 'tree' line format - bad sha1");
 755                 if (err)
 756                         return err;
 757         }
 758         buffer = p + 1;
 759         while (skip_prefix(buffer, "parent ", &buffer)) {
 760                 if (parse_oid_hex(buffer, &oid, &p) || *p != '\n') {
 761                         err = report(options, &commit->object, FSCK_MSG_BAD_PARENT_SHA1, "invalid 'parent' line format - bad sha1");
 762                         if (err)
 763                                 return err;
 764                 }
 765                 buffer = p + 1;
 766                 parent_line_count++;
 767         }
 768         graft = lookup_commit_graft(the_repository, &commit->object.oid);
 769         parent_count = commit_list_count(commit->parents);
 770         if (graft) {
 771                 if (graft->nr_parent == -1 && !parent_count)
 772                         ; /* shallow commit */
 773                 else if (graft->nr_parent != parent_count) {
 774                         err = report(options, &commit->object, FSCK_MSG_MISSING_GRAFT, "graft objects missing");
 775                         if (err)
 776                                 return err;
 777                 }
 778         } else {
 779                 if (parent_count != parent_line_count) {
 780                         err = report(options, &commit->object, FSCK_MSG_MISSING_PARENT, "parent objects missing");
 781                         if (err)
 782                                 return err;
 783                 }
 784         }
 785         author_count = 0;
 786         while (skip_prefix(buffer, "author ", &buffer)) {
 787                 author_count++;
 788                 err = fsck_ident(&buffer, &commit->object, options);
 789                 if (err)
 790                         return err;
 791         }
 792         if (author_count < 1)
 793                 err = report(options, &commit->object, FSCK_MSG_MISSING_AUTHOR, "invalid format - expected 'author' line");
 794         else if (author_count > 1)
 795                 err = report(options, &commit->object, FSCK_MSG_MULTIPLE_AUTHORS, "invalid format - multiple 'author' lines");
 796         if (err)
 797                 return err;
 798         if (!skip_prefix(buffer, "committer ", &buffer))
 799                 return report(options, &commit->object, FSCK_MSG_MISSING_COMMITTER, "invalid format - expected 'committer' line");
 800         err = fsck_ident(&buffer, &commit->object, options);
 801         if (err)
 802                 return err;
 803         if (!get_commit_tree(commit)) {
 804                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE, "could not load commit's tree %s", oid_to_hex(&tree_oid));
 805                 if (err)
 806                         return err;
 807         }
 808         if (memchr(buffer_begin, '\0', size)) {
 809                 err = report(options, &commit->object, FSCK_MSG_NUL_IN_COMMIT,
 810                              "NUL byte in the commit object body");
 811                 if (err)
 812                         return err;
 813         }
 814         return 0;
 815 }
 816
 817 static int fsck_commit(struct commit *commit, const char *data,
 818         unsigned long size, struct fsck_options *options)
 819 {
 820         const char *buffer = data ?  data : get_commit_buffer(commit, &size);
 821         int ret = fsck_commit_buffer(commit, buffer, size, options);
 822         if (!data)
 823                 unuse_commit_buffer(commit, buffer);
 824         return ret;
 825 }
 826
 827 static int fsck_tag_buffer(struct tag *tag, const char *data,
 828         unsigned long size, struct fsck_options *options)
 829 {
 830         struct object_id oid;
 831         int ret = 0;
 832         const char *buffer;
 833         char *to_free = NULL, *eol;
 834         struct strbuf sb = STRBUF_INIT;
 835         const char *p;
 836
 837         if (data)
 838                 buffer = data;
 839         else {
 840                 enum object_type type;
 841
 842                 buffer = to_free =
 843                         read_object_file(&tag->object.oid, &type, &size);
 844                 if (!buffer)
 845                         return report(options, &tag->object,
 846                                 FSCK_MSG_MISSING_TAG_OBJECT,
 847                                 "cannot read tag object");
 848
 849                 if (type != OBJ_TAG) {
 850                         ret = report(options, &tag->object,
 851                                 FSCK_MSG_TAG_OBJECT_NOT_TAG,
 852                                 "expected tag got %s",
 853                             type_name(type));
 854                         goto done;
 855                 }
 856         }
 857
 858         ret = verify_headers(buffer, size, &tag->object, options);
 859         if (ret)
 860                 goto done;
 861
 862         if (!skip_prefix(buffer, "object ", &buffer)) {
 863                 ret = report(options, &tag->object, FSCK_MSG_MISSING_OBJECT, "invalid format - expected 'object' line");
 864                 goto done;
 865         }
 866         if (parse_oid_hex(buffer, &oid, &p) || *p != '\n') {
 867                 ret = report(options, &tag->object, FSCK_MSG_BAD_OBJECT_SHA1, "invalid 'object' line format - bad sha1");
 868                 if (ret)
 869                         goto done;
 870         }
 871         buffer = p + 1;
 872
 873         if (!skip_prefix(buffer, "type ", &buffer)) {
 874                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE_ENTRY, "invalid format - expected 'type' line");
 875                 goto done;
 876         }
 877         eol = strchr(buffer, '\n');
 878         if (!eol) {
 879                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE, "invalid format - unexpected end after 'type' line");
 880                 goto done;
 881         }
 882         if (type_from_string_gently(buffer, eol - buffer, 1) < 0)
 883                 ret = report(options, &tag->object, FSCK_MSG_BAD_TYPE, "invalid 'type' value");
 884         if (ret)
 885                 goto done;
 886         buffer = eol + 1;
 887
 888         if (!skip_prefix(buffer, "tag ", &buffer)) {
 889                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG_ENTRY, "invalid format - expected 'tag' line");
 890                 goto done;
 891         }
 892         eol = strchr(buffer, '\n');
 893         if (!eol) {
 894                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG, "invalid format - unexpected end after 'type' line");
 895                 goto done;
 896         }
 897         strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer);
 898         if (check_refname_format(sb.buf, 0)) {
 899                 ret = report(options, &tag->object, FSCK_MSG_BAD_TAG_NAME,
 900                            "invalid 'tag' name: %.*s",
 901                            (int)(eol - buffer), buffer);
 902                 if (ret)
 903                         goto done;
 904         }
 905         buffer = eol + 1;
 906
 907         if (!skip_prefix(buffer, "tagger ", &buffer)) {
 908                 /* early tags do not contain 'tagger' lines; warn only */
 909                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
 910                 if (ret)
 911                         goto done;
 912         }
 913         else
 914                 ret = fsck_ident(&buffer, &tag->object, options);
 915
 916 done:
 917         strbuf_release(&sb);
 918         free(to_free);
 919         return ret;
 920 }
 921
 922 static int fsck_tag(struct tag *tag, const char *data,
 923         unsigned long size, struct fsck_options *options)
 924 {
 925         struct object *tagged = tag->tagged;
 926
 927         if (!tagged)
 928                 return report(options, &tag->object, FSCK_MSG_BAD_TAG_OBJECT, "could not load tagged object");
 929
 930         return fsck_tag_buffer(tag, data, size, options);
 931 }
 932
 933 struct fsck_gitmodules_data {
 934         struct object *obj;
 935         struct fsck_options *options;
 936         int ret;
 937 };
 938
 939 static int fsck_gitmodules_fn(const char *var, const char *value, void *vdata)
 940 {
 941         struct fsck_gitmodules_data *data = vdata;
 942         const char *subsection, *key;
 943         int subsection_len;
 944         char *name;
 945
 946         if (parse_config_key(var, "submodule", &subsection, &subsection_len, &key) < 0 ||
 947             !subsection)
 948                 return 0;
 949
 950         name = xmemdupz(subsection, subsection_len);
 951         if (check_submodule_name(name) < 0)
 952                 data->ret |= report(data->options, data->obj,
 953                                     FSCK_MSG_GITMODULES_NAME,
 954                                     "disallowed submodule name: %s",
 955                                     name);
 956         if (!strcmp(key, "url") && value &&
 957             looks_like_command_line_option(value))
 958                 data->ret |= report(data->options, data->obj,
 959                                     FSCK_MSG_GITMODULES_URL,
 960                                     "disallowed submodule url: %s",
 961                                     value);
 962         if (!strcmp(key, "path") && value &&
 963             looks_like_command_line_option(value))
 964                 data->ret |= report(data->options, data->obj,
 965                                     FSCK_MSG_GITMODULES_PATH,
 966                                     "disallowed submodule path: %s",
 967                                     value);
 968         free(name);
 969
 970         return 0;
 971 }
 972
 973 static int fsck_blob(struct blob *blob, const char *buf,
 974                      unsigned long size, struct fsck_options *options)
 975 {
 976         struct fsck_gitmodules_data data;
 977         struct config_options config_opts = { 0 };
 978
 979         if (!oidset_contains(&gitmodules_found, &blob->object.oid))
 980                 return 0;
 981         oidset_insert(&gitmodules_done, &blob->object.oid);
 982
 983         if (object_on_skiplist(options, &blob->object))
 984                 return 0;
 985
 986         if (!buf) {
 987                 /*
 988                  * A missing buffer here is a sign that the caller found the
 989                  * blob too gigantic to load into memory. Let's just consider
 990                  * that an error.
 991                  */
 992                 return report(options, &blob->object,
 993                               FSCK_MSG_GITMODULES_LARGE,
 994                               ".gitmodules too large to parse");
 995         }
 996
 997         data.obj = &blob->object;
 998         data.options = options;
 999         data.ret = 0;
1000         config_opts.error_action = CONFIG_ERROR_SILENT;
1001         if (git_config_from_mem(fsck_gitmodules_fn, CONFIG_ORIGIN_BLOB,
1002                                 ".gitmodules", buf, size, &data, &config_opts))
1003                 data.ret |= report(options, &blob->object,
1004                                    FSCK_MSG_GITMODULES_PARSE,
1005                                    "could not parse gitmodules blob");
1006
1007         return data.ret;
1008 }
1009
1010 int fsck_object(struct object *obj, void *data, unsigned long size,
1011         struct fsck_options *options)
1012 {
1013         if (!obj)
1014                 return report(options, obj, FSCK_MSG_BAD_OBJECT_SHA1, "no valid object to fsck");
1015
1016         if (obj->type == OBJ_BLOB)
1017                 return fsck_blob((struct blob *)obj, data, size, options);
1018         if (obj->type == OBJ_TREE)
1019                 return fsck_tree((struct tree *) obj, options);
1020         if (obj->type == OBJ_COMMIT)
1021                 return fsck_commit((struct commit *) obj, (const char *) data,
1022                         size, options);
1023         if (obj->type == OBJ_TAG)
1024                 return fsck_tag((struct tag *) obj, (const char *) data,
1025                         size, options);
1026
1027         return report(options, obj, FSCK_MSG_UNKNOWN_TYPE, "unknown type '%d' (internal fsck error)",
1028                           obj->type);
1029 }
1030
1031 int fsck_error_function(struct fsck_options *o,
1032         struct object *obj, int msg_type, const char *message)
1033 {
1034         if (msg_type == FSCK_WARN) {
1035                 warning("object %s: %s", describe_object(o, obj), message);
1036                 return 0;
1037         }
1038         error("object %s: %s", describe_object(o, obj), message);
1039         return 1;
1040 }
1041
1042 int fsck_finish(struct fsck_options *options)
1043 {
1044         int ret = 0;
1045         struct oidset_iter iter;
1046         const struct object_id *oid;
1047
1048         oidset_iter_init(&gitmodules_found, &iter);
1049         while ((oid = oidset_iter_next(&iter))) {
1050                 struct blob *blob;
1051                 enum object_type type;
1052                 unsigned long size;
1053                 char *buf;
1054
1055                 if (oidset_contains(&gitmodules_done, oid))
1056                         continue;
1057
1058                 blob = lookup_blob(the_repository, oid);
1059                 if (!blob) {
1060                         struct object *obj = lookup_unknown_object(oid);
1061                         ret |= report(options, obj,
1062                                       FSCK_MSG_GITMODULES_BLOB,
1063                                       "non-blob found at .gitmodules");
1064                         continue;
1065                 }
1066
1067                 buf = read_object_file(oid, &type, &size);
1068                 if (!buf) {
1069                         if (is_promisor_object(&blob->object.oid))
1070                                 continue;
1071                         ret |= report(options, &blob->object,
1072                                       FSCK_MSG_GITMODULES_MISSING,
1073                                       "unable to read .gitmodules blob");
1074                         continue;
1075                 }
1076
1077                 if (type == OBJ_BLOB)
1078                         ret |= fsck_blob(blob, buf, size, options);
1079                 else
1080                         ret |= report(options, &blob->object,
1081                                       FSCK_MSG_GITMODULES_BLOB,
1082                                       "non-blob found at .gitmodules");
1083                 free(buf);
1084         }
1085
1086
1087         oidset_clear(&gitmodules_found);
1088         oidset_clear(&gitmodules_done);
1089         return ret;
1090 }