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 "url.h"
  13 #include "utf8.h"
  14 #include "decorate.h"
  15 #include "oidset.h"
  16 #include "packfile.h"
  17 #include "submodule-config.h"
  18 #include "config.h"
  19 #include "credential.h"
  20 #include "help.h"
  21
  22 static struct oidset gitmodules_found = OIDSET_INIT;
  23 static struct oidset gitmodules_done = OIDSET_INIT;
  24
  25 #define FSCK_FATAL -1
  26 #define FSCK_INFO -2
  27
  28 #define FOREACH_MSG_ID(FUNC) \
  29         /* fatal errors */ \
  30         FUNC(NUL_IN_HEADER, FATAL) \
  31         FUNC(UNTERMINATED_HEADER, FATAL) \
  32         /* errors */ \
  33         FUNC(BAD_DATE, ERROR) \
  34         FUNC(BAD_DATE_OVERFLOW, ERROR) \
  35         FUNC(BAD_EMAIL, ERROR) \
  36         FUNC(BAD_NAME, ERROR) \
  37         FUNC(BAD_OBJECT_SHA1, ERROR) \
  38         FUNC(BAD_PARENT_SHA1, ERROR) \
  39         FUNC(BAD_TAG_OBJECT, ERROR) \
  40         FUNC(BAD_TIMEZONE, ERROR) \
  41         FUNC(BAD_TREE, ERROR) \
  42         FUNC(BAD_TREE_SHA1, ERROR) \
  43         FUNC(BAD_TYPE, ERROR) \
  44         FUNC(DUPLICATE_ENTRIES, ERROR) \
  45         FUNC(MISSING_AUTHOR, ERROR) \
  46         FUNC(MISSING_COMMITTER, ERROR) \
  47         FUNC(MISSING_EMAIL, ERROR) \
  48         FUNC(MISSING_GRAFT, ERROR) \
  49         FUNC(MISSING_NAME_BEFORE_EMAIL, ERROR) \
  50         FUNC(MISSING_OBJECT, ERROR) \
  51         FUNC(MISSING_PARENT, ERROR) \
  52         FUNC(MISSING_SPACE_BEFORE_DATE, ERROR) \
  53         FUNC(MISSING_SPACE_BEFORE_EMAIL, ERROR) \
  54         FUNC(MISSING_TAG, ERROR) \
  55         FUNC(MISSING_TAG_ENTRY, ERROR) \
  56         FUNC(MISSING_TAG_OBJECT, ERROR) \
  57         FUNC(MISSING_TREE, ERROR) \
  58         FUNC(MISSING_TREE_OBJECT, ERROR) \
  59         FUNC(MISSING_TYPE, ERROR) \
  60         FUNC(MISSING_TYPE_ENTRY, ERROR) \
  61         FUNC(MULTIPLE_AUTHORS, ERROR) \
  62         FUNC(TAG_OBJECT_NOT_TAG, ERROR) \
  63         FUNC(TREE_NOT_SORTED, ERROR) \
  64         FUNC(UNKNOWN_TYPE, ERROR) \
  65         FUNC(ZERO_PADDED_DATE, ERROR) \
  66         FUNC(GITMODULES_MISSING, ERROR) \
  67         FUNC(GITMODULES_BLOB, ERROR) \
  68         FUNC(GITMODULES_LARGE, ERROR) \
  69         FUNC(GITMODULES_NAME, ERROR) \
  70         FUNC(GITMODULES_SYMLINK, ERROR) \
  71         FUNC(GITMODULES_URL, ERROR) \
  72         FUNC(GITMODULES_PATH, ERROR) \
  73         FUNC(GITMODULES_UPDATE, ERROR) \
  74         /* warnings */ \
  75         FUNC(BAD_FILEMODE, WARN) \
  76         FUNC(EMPTY_NAME, WARN) \
  77         FUNC(FULL_PATHNAME, WARN) \
  78         FUNC(HAS_DOT, WARN) \
  79         FUNC(HAS_DOTDOT, WARN) \
  80         FUNC(HAS_DOTGIT, WARN) \
  81         FUNC(NULL_SHA1, WARN) \
  82         FUNC(ZERO_PADDED_FILEMODE, WARN) \
  83         FUNC(NUL_IN_COMMIT, WARN) \
  84         /* infos (reported as warnings, but ignored by default) */ \
  85         FUNC(GITMODULES_PARSE, INFO) \
  86         FUNC(BAD_TAG_NAME, INFO) \
  87         FUNC(MISSING_TAGGER_ENTRY, INFO)
  88
  89 #define MSG_ID(id, msg_type) FSCK_MSG_##id,
  90 enum fsck_msg_id {
  91         FOREACH_MSG_ID(MSG_ID)
  92         FSCK_MSG_MAX
  93 };
  94 #undef MSG_ID
  95
  96 #define STR(x) #x
  97 #define MSG_ID(id, msg_type) { STR(id), NULL, NULL, FSCK_##msg_type },
  98 static struct {
  99         const char *id_string;
 100         const char *downcased;
 101         const char *camelcased;
 102         int msg_type;
 103 } msg_id_info[FSCK_MSG_MAX + 1] = {
 104         FOREACH_MSG_ID(MSG_ID)
 105         { NULL, NULL, NULL, -1 }
 106 };
 107 #undef MSG_ID
 108
 109 static void prepare_msg_ids(void)
 110 {
 111         int i;
 112
 113         if (msg_id_info[0].downcased)
 114                 return;
 115
 116         /* convert id_string to lower case, without underscores. */
 117         for (i = 0; i < FSCK_MSG_MAX; i++) {
 118                 const char *p = msg_id_info[i].id_string;
 119                 int len = strlen(p);
 120                 char *q = xmalloc(len);
 121
 122                 msg_id_info[i].downcased = q;
 123                 while (*p)
 124                         if (*p == '_')
 125                                 p++;
 126                         else
 127                                 *(q)++ = tolower(*(p)++);
 128                 *q = '\0';
 129
 130                 p = msg_id_info[i].id_string;
 131                 q = xmalloc(len);
 132                 msg_id_info[i].camelcased = q;
 133                 while (*p) {
 134                         if (*p == '_') {
 135                                 p++;
 136                                 if (*p)
 137                                         *q++ = *p++;
 138                         } else {
 139                                 *q++ = tolower(*p++);
 140                         }
 141                 }
 142                 *q = '\0';
 143         }
 144 }
 145
 146 static int parse_msg_id(const char *text)
 147 {
 148         int i;
 149
 150         prepare_msg_ids();
 151
 152         for (i = 0; i < FSCK_MSG_MAX; i++)
 153                 if (!strcmp(text, msg_id_info[i].downcased))
 154                         return i;
 155
 156         return -1;
 157 }
 158
 159 void list_config_fsck_msg_ids(struct string_list *list, const char *prefix)
 160 {
 161         int i;
 162
 163         prepare_msg_ids();
 164
 165         for (i = 0; i < FSCK_MSG_MAX; i++)
 166                 list_config_item(list, prefix, msg_id_info[i].camelcased);
 167 }
 168
 169 static int fsck_msg_type(enum fsck_msg_id msg_id,
 170         struct fsck_options *options)
 171 {
 172         int msg_type;
 173
 174         assert(msg_id >= 0 && msg_id < FSCK_MSG_MAX);
 175
 176         if (options->msg_type)
 177                 msg_type = options->msg_type[msg_id];
 178         else {
 179                 msg_type = msg_id_info[msg_id].msg_type;
 180                 if (options->strict && msg_type == FSCK_WARN)
 181                         msg_type = FSCK_ERROR;
 182         }
 183
 184         return msg_type;
 185 }
 186
 187 static int parse_msg_type(const char *str)
 188 {
 189         if (!strcmp(str, "error"))
 190                 return FSCK_ERROR;
 191         else if (!strcmp(str, "warn"))
 192                 return FSCK_WARN;
 193         else if (!strcmp(str, "ignore"))
 194                 return FSCK_IGNORE;
 195         else
 196                 die("Unknown fsck message type: '%s'", str);
 197 }
 198
 199 int is_valid_msg_type(const char *msg_id, const char *msg_type)
 200 {
 201         if (parse_msg_id(msg_id) < 0)
 202                 return 0;
 203         parse_msg_type(msg_type);
 204         return 1;
 205 }
 206
 207 void fsck_set_msg_type(struct fsck_options *options,
 208                 const char *msg_id, const char *msg_type)
 209 {
 210         int id = parse_msg_id(msg_id), type;
 211
 212         if (id < 0)
 213                 die("Unhandled message id: %s", msg_id);
 214         type = parse_msg_type(msg_type);
 215
 216         if (type != FSCK_ERROR && msg_id_info[id].msg_type == FSCK_FATAL)
 217                 die("Cannot demote %s to %s", msg_id, msg_type);
 218
 219         if (!options->msg_type) {
 220                 int i;
 221                 int *msg_type;
 222                 ALLOC_ARRAY(msg_type, FSCK_MSG_MAX);
 223                 for (i = 0; i < FSCK_MSG_MAX; i++)
 224                         msg_type[i] = fsck_msg_type(i, options);
 225                 options->msg_type = msg_type;
 226         }
 227
 228         options->msg_type[id] = type;
 229 }
 230
 231 void fsck_set_msg_types(struct fsck_options *options, const char *values)
 232 {
 233         char *buf = xstrdup(values), *to_free = buf;
 234         int done = 0;
 235
 236         while (!done) {
 237                 int len = strcspn(buf, " ,|"), equal;
 238
 239                 done = !buf[len];
 240                 if (!len) {
 241                         buf++;
 242                         continue;
 243                 }
 244                 buf[len] = '\0';
 245
 246                 for (equal = 0;
 247                      equal < len && buf[equal] != '=' && buf[equal] != ':';
 248                      equal++)
 249                         buf[equal] = tolower(buf[equal]);
 250                 buf[equal] = '\0';
 251
 252                 if (!strcmp(buf, "skiplist")) {
 253                         if (equal == len)
 254                                 die("skiplist requires a path");
 255                         oidset_parse_file(&options->skiplist, buf + equal + 1);
 256                         buf += len + 1;
 257                         continue;
 258                 }
 259
 260                 if (equal == len)
 261                         die("Missing '=': '%s'", buf);
 262
 263                 fsck_set_msg_type(options, buf, buf + equal + 1);
 264                 buf += len + 1;
 265         }
 266         free(to_free);
 267 }
 268
 269 static void append_msg_id(struct strbuf *sb, const char *msg_id)
 270 {
 271         for (;;) {
 272                 char c = *(msg_id)++;
 273
 274                 if (!c)
 275                         break;
 276                 if (c != '_')
 277                         strbuf_addch(sb, tolower(c));
 278                 else {
 279                         assert(*msg_id);
 280                         strbuf_addch(sb, *(msg_id)++);
 281                 }
 282         }
 283
 284         strbuf_addstr(sb, ": ");
 285 }
 286
 287 static int object_on_skiplist(struct fsck_options *opts, struct object *obj)
 288 {
 289         return opts && obj && oidset_contains(&opts->skiplist, &obj->oid);
 290 }
 291
 292 __attribute__((format (printf, 4, 5)))
 293 static int report(struct fsck_options *options, struct object *object,
 294         enum fsck_msg_id id, const char *fmt, ...)
 295 {
 296         va_list ap;
 297         struct strbuf sb = STRBUF_INIT;
 298         int msg_type = fsck_msg_type(id, options), result;
 299
 300         if (msg_type == FSCK_IGNORE)
 301                 return 0;
 302
 303         if (object_on_skiplist(options, object))
 304                 return 0;
 305
 306         if (msg_type == FSCK_FATAL)
 307                 msg_type = FSCK_ERROR;
 308         else if (msg_type == FSCK_INFO)
 309                 msg_type = FSCK_WARN;
 310
 311         append_msg_id(&sb, msg_id_info[id].id_string);
 312
 313         va_start(ap, fmt);
 314         strbuf_vaddf(&sb, fmt, ap);
 315         result = options->error_func(options, object, msg_type, sb.buf);
 316         strbuf_release(&sb);
 317         va_end(ap);
 318
 319         return result;
 320 }
 321
 322 static char *get_object_name(struct fsck_options *options, struct object *obj)
 323 {
 324         if (!options->object_names)
 325                 return NULL;
 326         return lookup_decoration(options->object_names, obj);
 327 }
 328
 329 static void put_object_name(struct fsck_options *options, struct object *obj,
 330         const char *fmt, ...)
 331 {
 332         va_list ap;
 333         struct strbuf buf = STRBUF_INIT;
 334         char *existing;
 335
 336         if (!options->object_names)
 337                 return;
 338         existing = lookup_decoration(options->object_names, obj);
 339         if (existing)
 340                 return;
 341         va_start(ap, fmt);
 342         strbuf_vaddf(&buf, fmt, ap);
 343         add_decoration(options->object_names, obj, strbuf_detach(&buf, NULL));
 344         va_end(ap);
 345 }
 346
 347 static const char *describe_object(struct fsck_options *o, struct object *obj)
 348 {
 349         static struct strbuf buf = STRBUF_INIT;
 350         char *name;
 351
 352         strbuf_reset(&buf);
 353         strbuf_addstr(&buf, oid_to_hex(&obj->oid));
 354         if (o->object_names && (name = lookup_decoration(o->object_names, obj)))
 355                 strbuf_addf(&buf, " (%s)", name);
 356
 357         return buf.buf;
 358 }
 359
 360 static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *options)
 361 {
 362         struct tree_desc desc;
 363         struct name_entry entry;
 364         int res = 0;
 365         const char *name;
 366
 367         if (parse_tree(tree))
 368                 return -1;
 369
 370         name = get_object_name(options, &tree->object);
 371         if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
 372                 return -1;
 373         while (tree_entry_gently(&desc, &entry)) {
 374                 struct object *obj;
 375                 int result;
 376
 377                 if (S_ISGITLINK(entry.mode))
 378                         continue;
 379
 380                 if (S_ISDIR(entry.mode)) {
 381                         obj = (struct object *)lookup_tree(the_repository, &entry.oid);
 382                         if (name && obj)
 383                                 put_object_name(options, obj, "%s%s/", name,
 384                                         entry.path);
 385                         result = options->walk(obj, OBJ_TREE, data, options);
 386                 }
 387                 else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode)) {
 388                         obj = (struct object *)lookup_blob(the_repository, &entry.oid);
 389                         if (name && obj)
 390                                 put_object_name(options, obj, "%s%s", name,
 391                                         entry.path);
 392                         result = options->walk(obj, OBJ_BLOB, data, options);
 393                 }
 394                 else {
 395                         result = error("in tree %s: entry %s has bad mode %.6o",
 396                                         describe_object(options, &tree->object), entry.path, entry.mode);
 397                 }
 398                 if (result < 0)
 399                         return result;
 400                 if (!res)
 401                         res = result;
 402         }
 403         return res;
 404 }
 405
 406 static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_options *options)
 407 {
 408         int counter = 0, generation = 0, name_prefix_len = 0;
 409         struct commit_list *parents;
 410         int res;
 411         int result;
 412         const char *name;
 413
 414         if (parse_commit(commit))
 415                 return -1;
 416
 417         name = get_object_name(options, &commit->object);
 418         if (name)
 419                 put_object_name(options, &get_commit_tree(commit)->object,
 420                                 "%s:", name);
 421
 422         result = options->walk((struct object *)get_commit_tree(commit),
 423                                OBJ_TREE, data, options);
 424         if (result < 0)
 425                 return result;
 426         res = result;
 427
 428         parents = commit->parents;
 429         if (name && parents) {
 430                 int len = strlen(name), power;
 431
 432                 if (len && name[len - 1] == '^') {
 433                         generation = 1;
 434                         name_prefix_len = len - 1;
 435                 }
 436                 else { /* parse ~<generation> suffix */
 437                         for (generation = 0, power = 1;
 438                              len && isdigit(name[len - 1]);
 439                              power *= 10)
 440                                 generation += power * (name[--len] - '0');
 441                         if (power > 1 && len && name[len - 1] == '~')
 442                                 name_prefix_len = len - 1;
 443                 }
 444         }
 445
 446         while (parents) {
 447                 if (name) {
 448                         struct object *obj = &parents->item->object;
 449
 450                         if (counter++)
 451                                 put_object_name(options, obj, "%s^%d",
 452                                         name, counter);
 453                         else if (generation > 0)
 454                                 put_object_name(options, obj, "%.*s~%d",
 455                                         name_prefix_len, name, generation + 1);
 456                         else
 457                                 put_object_name(options, obj, "%s^", name);
 458                 }
 459                 result = options->walk((struct object *)parents->item, OBJ_COMMIT, data, options);
 460                 if (result < 0)
 461                         return result;
 462                 if (!res)
 463                         res = result;
 464                 parents = parents->next;
 465         }
 466         return res;
 467 }
 468
 469 static int fsck_walk_tag(struct tag *tag, void *data, struct fsck_options *options)
 470 {
 471         char *name = get_object_name(options, &tag->object);
 472
 473         if (parse_tag(tag))
 474                 return -1;
 475         if (name)
 476                 put_object_name(options, tag->tagged, "%s", name);
 477         return options->walk(tag->tagged, OBJ_ANY, data, options);
 478 }
 479
 480 int fsck_walk(struct object *obj, void *data, struct fsck_options *options)
 481 {
 482         if (!obj)
 483                 return -1;
 484
 485         if (obj->type == OBJ_NONE)
 486                 parse_object(the_repository, &obj->oid);
 487
 488         switch (obj->type) {
 489         case OBJ_BLOB:
 490                 return 0;
 491         case OBJ_TREE:
 492                 return fsck_walk_tree((struct tree *)obj, data, options);
 493         case OBJ_COMMIT:
 494                 return fsck_walk_commit((struct commit *)obj, data, options);
 495         case OBJ_TAG:
 496                 return fsck_walk_tag((struct tag *)obj, data, options);
 497         default:
 498                 error("Unknown object type for %s", describe_object(options, obj));
 499                 return -1;
 500         }
 501 }
 502
 503 /*
 504  * The entries in a tree are ordered in the _path_ order,
 505  * which means that a directory entry is ordered by adding
 506  * a slash to the end of it.
 507  *
 508  * So a directory called "a" is ordered _after_ a file
 509  * called "a.c", because "a/" sorts after "a.c".
 510  */
 511 #define TREE_UNORDERED (-1)
 512 #define TREE_HAS_DUPS  (-2)
 513
 514 static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
 515 {
 516         int len1 = strlen(name1);
 517         int len2 = strlen(name2);
 518         int len = len1 < len2 ? len1 : len2;
 519         unsigned char c1, c2;
 520         int cmp;
 521
 522         cmp = memcmp(name1, name2, len);
 523         if (cmp < 0)
 524                 return 0;
 525         if (cmp > 0)
 526                 return TREE_UNORDERED;
 527
 528         /*
 529          * Ok, the first <len> characters are the same.
 530          * Now we need to order the next one, but turn
 531          * a '\0' into a '/' for a directory entry.
 532          */
 533         c1 = name1[len];
 534         c2 = name2[len];
 535         if (!c1 && !c2)
 536                 /*
 537                  * git-write-tree used to write out a nonsense tree that has
 538                  * entries with the same name, one blob and one tree.  Make
 539                  * sure we do not have duplicate entries.
 540                  */
 541                 return TREE_HAS_DUPS;
 542         if (!c1 && S_ISDIR(mode1))
 543                 c1 = '/';
 544         if (!c2 && S_ISDIR(mode2))
 545                 c2 = '/';
 546         return c1 < c2 ? 0 : TREE_UNORDERED;
 547 }
 548
 549 static int fsck_tree(struct tree *item, struct fsck_options *options)
 550 {
 551         int retval = 0;
 552         int has_null_sha1 = 0;
 553         int has_full_path = 0;
 554         int has_empty_name = 0;
 555         int has_dot = 0;
 556         int has_dotdot = 0;
 557         int has_dotgit = 0;
 558         int has_zero_pad = 0;
 559         int has_bad_modes = 0;
 560         int has_dup_entries = 0;
 561         int not_properly_sorted = 0;
 562         struct tree_desc desc;
 563         unsigned o_mode;
 564         const char *o_name;
 565
 566         if (init_tree_desc_gently(&desc, item->buffer, item->size)) {
 567                 retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
 568                 return retval;
 569         }
 570
 571         o_mode = 0;
 572         o_name = NULL;
 573
 574         while (desc.size) {
 575                 unsigned short mode;
 576                 const char *name, *backslash;
 577                 const struct object_id *oid;
 578
 579                 oid = tree_entry_extract(&desc, &name, &mode);
 580
 581                 has_null_sha1 |= is_null_oid(oid);
 582                 has_full_path |= !!strchr(name, '/');
 583                 has_empty_name |= !*name;
 584                 has_dot |= !strcmp(name, ".");
 585                 has_dotdot |= !strcmp(name, "..");
 586                 has_dotgit |= is_hfs_dotgit(name) || is_ntfs_dotgit(name);
 587                 has_zero_pad |= *(char *)desc.buffer == '0';
 588
 589                 if (is_hfs_dotgitmodules(name) || is_ntfs_dotgitmodules(name)) {
 590                         if (!S_ISLNK(mode))
 591                                 oidset_insert(&gitmodules_found, oid);
 592                         else
 593                                 retval += report(options, &item->object,
 594                                                  FSCK_MSG_GITMODULES_SYMLINK,
 595                                                  ".gitmodules is a symbolic link");
 596                 }
 597
 598                 if ((backslash = strchr(name, '\\'))) {
 599                         while (backslash) {
 600                                 backslash++;
 601                                 has_dotgit |= is_ntfs_dotgit(backslash);
 602                                 if (is_ntfs_dotgitmodules(backslash)) {
 603                                         if (!S_ISLNK(mode))
 604                                                 oidset_insert(&gitmodules_found, oid);
 605                                         else
 606                                                 retval += report(options, &item->object,
 607                                                                  FSCK_MSG_GITMODULES_SYMLINK,
 608                                                                  ".gitmodules is a symbolic link");
 609                                 }
 610                                 backslash = strchr(backslash, '\\');
 611                         }
 612                 }
 613
 614                 if (update_tree_entry_gently(&desc)) {
 615                         retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
 616                         break;
 617                 }
 618
 619                 switch (mode) {
 620                 /*
 621                  * Standard modes..
 622                  */
 623                 case S_IFREG | 0755:
 624                 case S_IFREG | 0644:
 625                 case S_IFLNK:
 626                 case S_IFDIR:
 627                 case S_IFGITLINK:
 628                         break;
 629                 /*
 630                  * This is nonstandard, but we had a few of these
 631                  * early on when we honored the full set of mode
 632                  * bits..
 633                  */
 634                 case S_IFREG | 0664:
 635                         if (!options->strict)
 636                                 break;
 637                         /* fallthrough */
 638                 default:
 639                         has_bad_modes = 1;
 640                 }
 641
 642                 if (o_name) {
 643                         switch (verify_ordered(o_mode, o_name, mode, name)) {
 644                         case TREE_UNORDERED:
 645                                 not_properly_sorted = 1;
 646                                 break;
 647                         case TREE_HAS_DUPS:
 648                                 has_dup_entries = 1;
 649                                 break;
 650                         default:
 651                                 break;
 652                         }
 653                 }
 654
 655                 o_mode = mode;
 656                 o_name = name;
 657         }
 658
 659         if (has_null_sha1)
 660                 retval += report(options, &item->object, FSCK_MSG_NULL_SHA1, "contains entries pointing to null sha1");
 661         if (has_full_path)
 662                 retval += report(options, &item->object, FSCK_MSG_FULL_PATHNAME, "contains full pathnames");
 663         if (has_empty_name)
 664                 retval += report(options, &item->object, FSCK_MSG_EMPTY_NAME, "contains empty pathname");
 665         if (has_dot)
 666                 retval += report(options, &item->object, FSCK_MSG_HAS_DOT, "contains '.'");
 667         if (has_dotdot)
 668                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTDOT, "contains '..'");
 669         if (has_dotgit)
 670                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTGIT, "contains '.git'");
 671         if (has_zero_pad)
 672                 retval += report(options, &item->object, FSCK_MSG_ZERO_PADDED_FILEMODE, "contains zero-padded file modes");
 673         if (has_bad_modes)
 674                 retval += report(options, &item->object, FSCK_MSG_BAD_FILEMODE, "contains bad file modes");
 675         if (has_dup_entries)
 676                 retval += report(options, &item->object, FSCK_MSG_DUPLICATE_ENTRIES, "contains duplicate file entries");
 677         if (not_properly_sorted)
 678                 retval += report(options, &item->object, FSCK_MSG_TREE_NOT_SORTED, "not properly sorted");
 679         return retval;
 680 }
 681
 682 static int verify_headers(const void *data, unsigned long size,
 683                           struct object *obj, struct fsck_options *options)
 684 {
 685         const char *buffer = (const char *)data;
 686         unsigned long i;
 687
 688         for (i = 0; i < size; i++) {
 689                 switch (buffer[i]) {
 690                 case '\0':
 691                         return report(options, obj,
 692                                 FSCK_MSG_NUL_IN_HEADER,
 693                                 "unterminated header: NUL at offset %ld", i);
 694                 case '\n':
 695                         if (i + 1 < size && buffer[i + 1] == '\n')
 696                                 return 0;
 697                 }
 698         }
 699
 700         /*
 701          * We did not find double-LF that separates the header
 702          * and the body.  Not having a body is not a crime but
 703          * we do want to see the terminating LF for the last header
 704          * line.
 705          */
 706         if (size && buffer[size - 1] == '\n')
 707                 return 0;
 708
 709         return report(options, obj,
 710                 FSCK_MSG_UNTERMINATED_HEADER, "unterminated header");
 711 }
 712
 713 static int fsck_ident(const char **ident, struct object *obj, struct fsck_options *options)
 714 {
 715         const char *p = *ident;
 716         char *end;
 717
 718         *ident = strchrnul(*ident, '\n');
 719         if (**ident == '\n')
 720                 (*ident)++;
 721
 722         if (*p == '<')
 723                 return report(options, obj, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 724         p += strcspn(p, "<>\n");
 725         if (*p == '>')
 726                 return report(options, obj, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
 727         if (*p != '<')
 728                 return report(options, obj, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
 729         if (p[-1] != ' ')
 730                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 731         p++;
 732         p += strcspn(p, "<>\n");
 733         if (*p != '>')
 734                 return report(options, obj, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
 735         p++;
 736         if (*p != ' ')
 737                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
 738         p++;
 739         if (*p == '0' && p[1] != ' ')
 740                 return report(options, obj, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
 741         if (date_overflows(parse_timestamp(p, &end, 10)))
 742                 return report(options, obj, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
 743         if ((end == p || *end != ' '))
 744                 return report(options, obj, FSCK_MSG_BAD_DATE, "invalid author/committer line - bad date");
 745         p = end + 1;
 746         if ((*p != '+' && *p != '-') ||
 747             !isdigit(p[1]) ||
 748             !isdigit(p[2]) ||
 749             !isdigit(p[3]) ||
 750             !isdigit(p[4]) ||
 751             (p[5] != '\n'))
 752                 return report(options, obj, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
 753         p += 6;
 754         return 0;
 755 }
 756
 757 static int fsck_commit_buffer(struct commit *commit, const char *buffer,
 758         unsigned long size, struct fsck_options *options)
 759 {
 760         struct object_id tree_oid, oid;
 761         struct commit_graft *graft;
 762         unsigned parent_count, parent_line_count = 0, author_count;
 763         int err;
 764         const char *buffer_begin = buffer;
 765         const char *p;
 766
 767         if (verify_headers(buffer, size, &commit->object, options))
 768                 return -1;
 769
 770         if (!skip_prefix(buffer, "tree ", &buffer))
 771                 return report(options, &commit->object, FSCK_MSG_MISSING_TREE, "invalid format - expected 'tree' line");
 772         if (parse_oid_hex(buffer, &tree_oid, &p) || *p != '\n') {
 773                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE_SHA1, "invalid 'tree' line format - bad sha1");
 774                 if (err)
 775                         return err;
 776         }
 777         buffer = p + 1;
 778         while (skip_prefix(buffer, "parent ", &buffer)) {
 779                 if (parse_oid_hex(buffer, &oid, &p) || *p != '\n') {
 780                         err = report(options, &commit->object, FSCK_MSG_BAD_PARENT_SHA1, "invalid 'parent' line format - bad sha1");
 781                         if (err)
 782                                 return err;
 783                 }
 784                 buffer = p + 1;
 785                 parent_line_count++;
 786         }
 787         graft = lookup_commit_graft(the_repository, &commit->object.oid);
 788         parent_count = commit_list_count(commit->parents);
 789         if (graft) {
 790                 if (graft->nr_parent == -1 && !parent_count)
 791                         ; /* shallow commit */
 792                 else if (graft->nr_parent != parent_count) {
 793                         err = report(options, &commit->object, FSCK_MSG_MISSING_GRAFT, "graft objects missing");
 794                         if (err)
 795                                 return err;
 796                 }
 797         } else {
 798                 if (parent_count != parent_line_count) {
 799                         err = report(options, &commit->object, FSCK_MSG_MISSING_PARENT, "parent objects missing");
 800                         if (err)
 801                                 return err;
 802                 }
 803         }
 804         author_count = 0;
 805         while (skip_prefix(buffer, "author ", &buffer)) {
 806                 author_count++;
 807                 err = fsck_ident(&buffer, &commit->object, options);
 808                 if (err)
 809                         return err;
 810         }
 811         if (author_count < 1)
 812                 err = report(options, &commit->object, FSCK_MSG_MISSING_AUTHOR, "invalid format - expected 'author' line");
 813         else if (author_count > 1)
 814                 err = report(options, &commit->object, FSCK_MSG_MULTIPLE_AUTHORS, "invalid format - multiple 'author' lines");
 815         if (err)
 816                 return err;
 817         if (!skip_prefix(buffer, "committer ", &buffer))
 818                 return report(options, &commit->object, FSCK_MSG_MISSING_COMMITTER, "invalid format - expected 'committer' line");
 819         err = fsck_ident(&buffer, &commit->object, options);
 820         if (err)
 821                 return err;
 822         if (!get_commit_tree(commit)) {
 823                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE, "could not load commit's tree %s", oid_to_hex(&tree_oid));
 824                 if (err)
 825                         return err;
 826         }
 827         if (memchr(buffer_begin, '\0', size)) {
 828                 err = report(options, &commit->object, FSCK_MSG_NUL_IN_COMMIT,
 829                              "NUL byte in the commit object body");
 830                 if (err)
 831                         return err;
 832         }
 833         return 0;
 834 }
 835
 836 static int fsck_commit(struct commit *commit, const char *data,
 837         unsigned long size, struct fsck_options *options)
 838 {
 839         const char *buffer = data ?  data : get_commit_buffer(commit, &size);
 840         int ret = fsck_commit_buffer(commit, buffer, size, options);
 841         if (!data)
 842                 unuse_commit_buffer(commit, buffer);
 843         return ret;
 844 }
 845
 846 static int fsck_tag_buffer(struct tag *tag, const char *data,
 847         unsigned long size, struct fsck_options *options)
 848 {
 849         struct object_id oid;
 850         int ret = 0;
 851         const char *buffer;
 852         char *to_free = NULL, *eol;
 853         struct strbuf sb = STRBUF_INIT;
 854         const char *p;
 855
 856         if (data)
 857                 buffer = data;
 858         else {
 859                 enum object_type type;
 860
 861                 buffer = to_free =
 862                         read_object_file(&tag->object.oid, &type, &size);
 863                 if (!buffer)
 864                         return report(options, &tag->object,
 865                                 FSCK_MSG_MISSING_TAG_OBJECT,
 866                                 "cannot read tag object");
 867
 868                 if (type != OBJ_TAG) {
 869                         ret = report(options, &tag->object,
 870                                 FSCK_MSG_TAG_OBJECT_NOT_TAG,
 871                                 "expected tag got %s",
 872                             type_name(type));
 873                         goto done;
 874                 }
 875         }
 876
 877         ret = verify_headers(buffer, size, &tag->object, options);
 878         if (ret)
 879                 goto done;
 880
 881         if (!skip_prefix(buffer, "object ", &buffer)) {
 882                 ret = report(options, &tag->object, FSCK_MSG_MISSING_OBJECT, "invalid format - expected 'object' line");
 883                 goto done;
 884         }
 885         if (parse_oid_hex(buffer, &oid, &p) || *p != '\n') {
 886                 ret = report(options, &tag->object, FSCK_MSG_BAD_OBJECT_SHA1, "invalid 'object' line format - bad sha1");
 887                 if (ret)
 888                         goto done;
 889         }
 890         buffer = p + 1;
 891
 892         if (!skip_prefix(buffer, "type ", &buffer)) {
 893                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE_ENTRY, "invalid format - expected 'type' line");
 894                 goto done;
 895         }
 896         eol = strchr(buffer, '\n');
 897         if (!eol) {
 898                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE, "invalid format - unexpected end after 'type' line");
 899                 goto done;
 900         }
 901         if (type_from_string_gently(buffer, eol - buffer, 1) < 0)
 902                 ret = report(options, &tag->object, FSCK_MSG_BAD_TYPE, "invalid 'type' value");
 903         if (ret)
 904                 goto done;
 905         buffer = eol + 1;
 906
 907         if (!skip_prefix(buffer, "tag ", &buffer)) {
 908                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG_ENTRY, "invalid format - expected 'tag' line");
 909                 goto done;
 910         }
 911         eol = strchr(buffer, '\n');
 912         if (!eol) {
 913                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG, "invalid format - unexpected end after 'type' line");
 914                 goto done;
 915         }
 916         strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer);
 917         if (check_refname_format(sb.buf, 0)) {
 918                 ret = report(options, &tag->object, FSCK_MSG_BAD_TAG_NAME,
 919                            "invalid 'tag' name: %.*s",
 920                            (int)(eol - buffer), buffer);
 921                 if (ret)
 922                         goto done;
 923         }
 924         buffer = eol + 1;
 925
 926         if (!skip_prefix(buffer, "tagger ", &buffer)) {
 927                 /* early tags do not contain 'tagger' lines; warn only */
 928                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
 929                 if (ret)
 930                         goto done;
 931         }
 932         else
 933                 ret = fsck_ident(&buffer, &tag->object, options);
 934
 935 done:
 936         strbuf_release(&sb);
 937         free(to_free);
 938         return ret;
 939 }
 940
 941 static int fsck_tag(struct tag *tag, const char *data,
 942         unsigned long size, struct fsck_options *options)
 943 {
 944         struct object *tagged = tag->tagged;
 945
 946         if (!tagged)
 947                 return report(options, &tag->object, FSCK_MSG_BAD_TAG_OBJECT, "could not load tagged object");
 948
 949         return fsck_tag_buffer(tag, data, size, options);
 950 }
 951
 952 /*
 953  * Like builtin/submodule--helper.c's starts_with_dot_slash, but without
 954  * relying on the platform-dependent is_dir_sep helper.
 955  *
 956  * This is for use in checking whether a submodule URL is interpreted as
 957  * relative to the current directory on any platform, since \ is a
 958  * directory separator on Windows but not on other platforms.
 959  */
 960 static int starts_with_dot_slash(const char *str)
 961 {
 962         return str[0] == '.' && (str[1] == '/' || str[1] == '\\');
 963 }
 964
 965 /*
 966  * Like starts_with_dot_slash, this is a variant of submodule--helper's
 967  * helper of the same name with the twist that it accepts backslash as a
 968  * directory separator even on non-Windows platforms.
 969  */
 970 static int starts_with_dot_dot_slash(const char *str)
 971 {
 972         return str[0] == '.' && starts_with_dot_slash(str + 1);
 973 }
 974
 975 static int submodule_url_is_relative(const char *url)
 976 {
 977         return starts_with_dot_slash(url) || starts_with_dot_dot_slash(url);
 978 }
 979
 980 /*
 981  * Count directory components that a relative submodule URL should chop
 982  * from the remote_url it is to be resolved against.
 983  *
 984  * In other words, this counts "../" components at the start of a
 985  * submodule URL.
 986  *
 987  * Returns the number of directory components to chop and writes a
 988  * pointer to the next character of url after all leading "./" and
 989  * "../" components to out.
 990  */
 991 static int count_leading_dotdots(const char *url, const char **out)
 992 {
 993         int result = 0;
 994         while (1) {
 995                 if (starts_with_dot_dot_slash(url)) {
 996                         result++;
 997                         url += strlen("../");
 998                         continue;
 999                 }
1000                 if (starts_with_dot_slash(url)) {
1001                         url += strlen("./");
1002                         continue;
1003                 }
1004                 *out = url;
1005                 return result;
1006         }
1007 }
1008 /*
1009  * Check whether a transport is implemented by git-remote-curl.
1010  *
1011  * If it is, returns 1 and writes the URL that would be passed to
1012  * git-remote-curl to the "out" parameter.
1013  *
1014  * Otherwise, returns 0 and leaves "out" untouched.
1015  *
1016  * Examples:
1017  *   http::https://example.com/repo.git -> 1, https://example.com/repo.git
1018  *   https://example.com/repo.git -> 1, https://example.com/repo.git
1019  *   git://example.com/repo.git -> 0
1020  *
1021  * This is for use in checking for previously exploitable bugs that
1022  * required a submodule URL to be passed to git-remote-curl.
1023  */
1024 static int url_to_curl_url(const char *url, const char **out)
1025 {
1026         /*
1027          * We don't need to check for case-aliases, "http.exe", and so
1028          * on because in the default configuration, is_transport_allowed
1029          * prevents URLs with those schemes from being cloned
1030          * automatically.
1031          */
1032         if (skip_prefix(url, "http::", out) ||
1033             skip_prefix(url, "https::", out) ||
1034             skip_prefix(url, "ftp::", out) ||
1035             skip_prefix(url, "ftps::", out))
1036                 return 1;
1037         if (starts_with(url, "http://") ||
1038             starts_with(url, "https://") ||
1039             starts_with(url, "ftp://") ||
1040             starts_with(url, "ftps://")) {
1041                 *out = url;
1042                 return 1;
1043         }
1044         return 0;
1045 }
1046
1047 static int check_submodule_url(const char *url)
1048 {
1049         const char *curl_url;
1050
1051         if (looks_like_command_line_option(url))
1052                 return -1;
1053
1054         if (submodule_url_is_relative(url)) {
1055                 char *decoded;
1056                 const char *next;
1057                 int has_nl;
1058
1059                 /*
1060                  * This could be appended to an http URL and url-decoded;
1061                  * check for malicious characters.
1062                  */
1063                 decoded = url_decode(url);
1064                 has_nl = !!strchr(decoded, '\n');
1065
1066                 free(decoded);
1067                 if (has_nl)
1068                         return -1;
1069
1070                 /*
1071                  * URLs which escape their root via "../" can overwrite
1072                  * the host field and previous components, resolving to
1073                  * URLs like https::example.com/submodule.git and
1074                  * https:///example.com/submodule.git that were
1075                  * susceptible to CVE-2020-11008.
1076                  */
1077                 if (count_leading_dotdots(url, &next) > 0 &&
1078                     (*next == ':' || *next == '/'))
1079                         return -1;
1080         }
1081
1082         else if (url_to_curl_url(url, &curl_url)) {
1083                 struct credential c = CREDENTIAL_INIT;
1084                 int ret = 0;
1085                 if (credential_from_url_gently(&c, curl_url, 1) ||
1086                     !*c.host)
1087                         ret = -1;
1088                 credential_clear(&c);
1089                 return ret;
1090         }
1091
1092         return 0;
1093 }
1094
1095 struct fsck_gitmodules_data {
1096         struct object *obj;
1097         struct fsck_options *options;
1098         int ret;
1099 };
1100
1101 static int fsck_gitmodules_fn(const char *var, const char *value, void *vdata)
1102 {
1103         struct fsck_gitmodules_data *data = vdata;
1104         const char *subsection, *key;
1105         int subsection_len;
1106         char *name;
1107
1108         if (parse_config_key(var, "submodule", &subsection, &subsection_len, &key) < 0 ||
1109             !subsection)
1110                 return 0;
1111
1112         name = xmemdupz(subsection, subsection_len);
1113         if (check_submodule_name(name) < 0)
1114                 data->ret |= report(data->options, data->obj,
1115                                     FSCK_MSG_GITMODULES_NAME,
1116                                     "disallowed submodule name: %s",
1117                                     name);
1118         if (!strcmp(key, "url") && value &&
1119             check_submodule_url(value) < 0)
1120                 data->ret |= report(data->options, data->obj,
1121                                     FSCK_MSG_GITMODULES_URL,
1122                                     "disallowed submodule url: %s",
1123                                     value);
1124         if (!strcmp(key, "path") && value &&
1125             looks_like_command_line_option(value))
1126                 data->ret |= report(data->options, data->obj,
1127                                     FSCK_MSG_GITMODULES_PATH,
1128                                     "disallowed submodule path: %s",
1129                                     value);
1130         if (!strcmp(key, "update") && value &&
1131             parse_submodule_update_type(value) == SM_UPDATE_COMMAND)
1132                 data->ret |= report(data->options, data->obj,
1133                                     FSCK_MSG_GITMODULES_UPDATE,
1134                                     "disallowed submodule update setting: %s",
1135                                     value);
1136         free(name);
1137
1138         return 0;
1139 }
1140
1141 static int fsck_blob(struct blob *blob, const char *buf,
1142                      unsigned long size, struct fsck_options *options)
1143 {
1144         struct fsck_gitmodules_data data;
1145         struct config_options config_opts = { 0 };
1146
1147         if (!oidset_contains(&gitmodules_found, &blob->object.oid))
1148                 return 0;
1149         oidset_insert(&gitmodules_done, &blob->object.oid);
1150
1151         if (object_on_skiplist(options, &blob->object))
1152                 return 0;
1153
1154         if (!buf) {
1155                 /*
1156                  * A missing buffer here is a sign that the caller found the
1157                  * blob too gigantic to load into memory. Let's just consider
1158                  * that an error.
1159                  */
1160                 return report(options, &blob->object,
1161                               FSCK_MSG_GITMODULES_LARGE,
1162                               ".gitmodules too large to parse");
1163         }
1164
1165         data.obj = &blob->object;
1166         data.options = options;
1167         data.ret = 0;
1168         config_opts.error_action = CONFIG_ERROR_SILENT;
1169         if (git_config_from_mem(fsck_gitmodules_fn, CONFIG_ORIGIN_BLOB,
1170                                 ".gitmodules", buf, size, &data, &config_opts))
1171                 data.ret |= report(options, &blob->object,
1172                                    FSCK_MSG_GITMODULES_PARSE,
1173                                    "could not parse gitmodules blob");
1174
1175         return data.ret;
1176 }
1177
1178 int fsck_object(struct object *obj, void *data, unsigned long size,
1179         struct fsck_options *options)
1180 {
1181         if (!obj)
1182                 return report(options, obj, FSCK_MSG_BAD_OBJECT_SHA1, "no valid object to fsck");
1183
1184         if (obj->type == OBJ_BLOB)
1185                 return fsck_blob((struct blob *)obj, data, size, options);
1186         if (obj->type == OBJ_TREE)
1187                 return fsck_tree((struct tree *) obj, options);
1188         if (obj->type == OBJ_COMMIT)
1189                 return fsck_commit((struct commit *) obj, (const char *) data,
1190                         size, options);
1191         if (obj->type == OBJ_TAG)
1192                 return fsck_tag((struct tag *) obj, (const char *) data,
1193                         size, options);
1194
1195         return report(options, obj, FSCK_MSG_UNKNOWN_TYPE, "unknown type '%d' (internal fsck error)",
1196                           obj->type);
1197 }
1198
1199 int fsck_error_function(struct fsck_options *o,
1200         struct object *obj, int msg_type, const char *message)
1201 {
1202         if (msg_type == FSCK_WARN) {
1203                 warning("object %s: %s", describe_object(o, obj), message);
1204                 return 0;
1205         }
1206         error("object %s: %s", describe_object(o, obj), message);
1207         return 1;
1208 }
1209
1210 int fsck_finish(struct fsck_options *options)
1211 {
1212         int ret = 0;
1213         struct oidset_iter iter;
1214         const struct object_id *oid;
1215
1216         oidset_iter_init(&gitmodules_found, &iter);
1217         while ((oid = oidset_iter_next(&iter))) {
1218                 struct blob *blob;
1219                 enum object_type type;
1220                 unsigned long size;
1221                 char *buf;
1222
1223                 if (oidset_contains(&gitmodules_done, oid))
1224                         continue;
1225
1226                 blob = lookup_blob(the_repository, oid);
1227                 if (!blob) {
1228                         struct object *obj = lookup_unknown_object(oid);
1229                         ret |= report(options, obj,
1230                                       FSCK_MSG_GITMODULES_BLOB,
1231                                       "non-blob found at .gitmodules");
1232                         continue;
1233                 }
1234
1235                 buf = read_object_file(oid, &type, &size);
1236                 if (!buf) {
1237                         if (is_promisor_object(&blob->object.oid))
1238                                 continue;
1239                         ret |= report(options, &blob->object,
1240                                       FSCK_MSG_GITMODULES_MISSING,
1241                                       "unable to read .gitmodules blob");
1242                         continue;
1243                 }
1244
1245                 if (type == OBJ_BLOB)
1246                         ret |= fsck_blob(blob, buf, size, options);
1247                 else
1248                         ret |= report(options, &blob->object,
1249                                       FSCK_MSG_GITMODULES_BLOB,
1250                                       "non-blob found at .gitmodules");
1251                 free(buf);
1252         }
1253
1254
1255         oidset_clear(&gitmodules_found);
1256         oidset_clear(&gitmodules_done);
1257         return ret;
1258 }