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 void init_skiplist(struct fsck_options *options, const char *path)
 188 {
 189         FILE *fp;
 190         struct strbuf sb = STRBUF_INIT;
 191         struct object_id oid;
 192
 193         fp = fopen(path, "r");
 194         if (!fp)
 195                 die("Could not open skip list: %s", path);
 196         while (!strbuf_getline(&sb, fp)) {
 197                 const char *p;
 198                 const char *hash;
 199
 200                 /*
 201                  * Allow trailing comments, leading whitespace
 202                  * (including before commits), and empty or whitespace
 203                  * only lines.
 204                  */
 205                 hash = strchr(sb.buf, '#');
 206                 if (hash)
 207                         strbuf_setlen(&sb, hash - sb.buf);
 208                 strbuf_trim(&sb);
 209                 if (!sb.len)
 210                         continue;
 211
 212                 if (parse_oid_hex(sb.buf, &oid, &p) || *p != '\0')
 213                         die("Invalid SHA-1: %s", sb.buf);
 214                 oidset_insert(&options->skiplist, &oid);
 215         }
 216         if (ferror(fp))
 217                 die_errno("Could not read '%s'", path);
 218         fclose(fp);
 219         strbuf_release(&sb);
 220 }
 221
 222 static int parse_msg_type(const char *str)
 223 {
 224         if (!strcmp(str, "error"))
 225                 return FSCK_ERROR;
 226         else if (!strcmp(str, "warn"))
 227                 return FSCK_WARN;
 228         else if (!strcmp(str, "ignore"))
 229                 return FSCK_IGNORE;
 230         else
 231                 die("Unknown fsck message type: '%s'", str);
 232 }
 233
 234 int is_valid_msg_type(const char *msg_id, const char *msg_type)
 235 {
 236         if (parse_msg_id(msg_id) < 0)
 237                 return 0;
 238         parse_msg_type(msg_type);
 239         return 1;
 240 }
 241
 242 void fsck_set_msg_type(struct fsck_options *options,
 243                 const char *msg_id, const char *msg_type)
 244 {
 245         int id = parse_msg_id(msg_id), type;
 246
 247         if (id < 0)
 248                 die("Unhandled message id: %s", msg_id);
 249         type = parse_msg_type(msg_type);
 250
 251         if (type != FSCK_ERROR && msg_id_info[id].msg_type == FSCK_FATAL)
 252                 die("Cannot demote %s to %s", msg_id, msg_type);
 253
 254         if (!options->msg_type) {
 255                 int i;
 256                 int *msg_type;
 257                 ALLOC_ARRAY(msg_type, FSCK_MSG_MAX);
 258                 for (i = 0; i < FSCK_MSG_MAX; i++)
 259                         msg_type[i] = fsck_msg_type(i, options);
 260                 options->msg_type = msg_type;
 261         }
 262
 263         options->msg_type[id] = type;
 264 }
 265
 266 void fsck_set_msg_types(struct fsck_options *options, const char *values)
 267 {
 268         char *buf = xstrdup(values), *to_free = buf;
 269         int done = 0;
 270
 271         while (!done) {
 272                 int len = strcspn(buf, " ,|"), equal;
 273
 274                 done = !buf[len];
 275                 if (!len) {
 276                         buf++;
 277                         continue;
 278                 }
 279                 buf[len] = '\0';
 280
 281                 for (equal = 0;
 282                      equal < len && buf[equal] != '=' && buf[equal] != ':';
 283                      equal++)
 284                         buf[equal] = tolower(buf[equal]);
 285                 buf[equal] = '\0';
 286
 287                 if (!strcmp(buf, "skiplist")) {
 288                         if (equal == len)
 289                                 die("skiplist requires a path");
 290                         init_skiplist(options, buf + equal + 1);
 291                         buf += len + 1;
 292                         continue;
 293                 }
 294
 295                 if (equal == len)
 296                         die("Missing '=': '%s'", buf);
 297
 298                 fsck_set_msg_type(options, buf, buf + equal + 1);
 299                 buf += len + 1;
 300         }
 301         free(to_free);
 302 }
 303
 304 static void append_msg_id(struct strbuf *sb, const char *msg_id)
 305 {
 306         for (;;) {
 307                 char c = *(msg_id)++;
 308
 309                 if (!c)
 310                         break;
 311                 if (c != '_')
 312                         strbuf_addch(sb, tolower(c));
 313                 else {
 314                         assert(*msg_id);
 315                         strbuf_addch(sb, *(msg_id)++);
 316                 }
 317         }
 318
 319         strbuf_addstr(sb, ": ");
 320 }
 321
 322 static int object_on_skiplist(struct fsck_options *opts, struct object *obj)
 323 {
 324         return opts && obj && oidset_contains(&opts->skiplist, &obj->oid);
 325 }
 326
 327 __attribute__((format (printf, 4, 5)))
 328 static int report(struct fsck_options *options, struct object *object,
 329         enum fsck_msg_id id, const char *fmt, ...)
 330 {
 331         va_list ap;
 332         struct strbuf sb = STRBUF_INIT;
 333         int msg_type = fsck_msg_type(id, options), result;
 334
 335         if (msg_type == FSCK_IGNORE)
 336                 return 0;
 337
 338         if (object_on_skiplist(options, object))
 339                 return 0;
 340
 341         if (msg_type == FSCK_FATAL)
 342                 msg_type = FSCK_ERROR;
 343         else if (msg_type == FSCK_INFO)
 344                 msg_type = FSCK_WARN;
 345
 346         append_msg_id(&sb, msg_id_info[id].id_string);
 347
 348         va_start(ap, fmt);
 349         strbuf_vaddf(&sb, fmt, ap);
 350         result = options->error_func(options, object, msg_type, sb.buf);
 351         strbuf_release(&sb);
 352         va_end(ap);
 353
 354         return result;
 355 }
 356
 357 static char *get_object_name(struct fsck_options *options, struct object *obj)
 358 {
 359         if (!options->object_names)
 360                 return NULL;
 361         return lookup_decoration(options->object_names, obj);
 362 }
 363
 364 static void put_object_name(struct fsck_options *options, struct object *obj,
 365         const char *fmt, ...)
 366 {
 367         va_list ap;
 368         struct strbuf buf = STRBUF_INIT;
 369         char *existing;
 370
 371         if (!options->object_names)
 372                 return;
 373         existing = lookup_decoration(options->object_names, obj);
 374         if (existing)
 375                 return;
 376         va_start(ap, fmt);
 377         strbuf_vaddf(&buf, fmt, ap);
 378         add_decoration(options->object_names, obj, strbuf_detach(&buf, NULL));
 379         va_end(ap);
 380 }
 381
 382 static const char *describe_object(struct fsck_options *o, struct object *obj)
 383 {
 384         static struct strbuf buf = STRBUF_INIT;
 385         char *name;
 386
 387         strbuf_reset(&buf);
 388         strbuf_addstr(&buf, oid_to_hex(&obj->oid));
 389         if (o->object_names && (name = lookup_decoration(o->object_names, obj)))
 390                 strbuf_addf(&buf, " (%s)", name);
 391
 392         return buf.buf;
 393 }
 394
 395 static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *options)
 396 {
 397         struct tree_desc desc;
 398         struct name_entry entry;
 399         int res = 0;
 400         const char *name;
 401
 402         if (parse_tree(tree))
 403                 return -1;
 404
 405         name = get_object_name(options, &tree->object);
 406         if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
 407                 return -1;
 408         while (tree_entry_gently(&desc, &entry)) {
 409                 struct object *obj;
 410                 int result;
 411
 412                 if (S_ISGITLINK(entry.mode))
 413                         continue;
 414
 415                 if (S_ISDIR(entry.mode)) {
 416                         obj = (struct object *)lookup_tree(the_repository, entry.oid);
 417                         if (name && obj)
 418                                 put_object_name(options, obj, "%s%s/", name,
 419                                         entry.path);
 420                         result = options->walk(obj, OBJ_TREE, data, options);
 421                 }
 422                 else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode)) {
 423                         obj = (struct object *)lookup_blob(the_repository, entry.oid);
 424                         if (name && obj)
 425                                 put_object_name(options, obj, "%s%s", name,
 426                                         entry.path);
 427                         result = options->walk(obj, OBJ_BLOB, data, options);
 428                 }
 429                 else {
 430                         result = error("in tree %s: entry %s has bad mode %.6o",
 431                                         describe_object(options, &tree->object), entry.path, entry.mode);
 432                 }
 433                 if (result < 0)
 434                         return result;
 435                 if (!res)
 436                         res = result;
 437         }
 438         return res;
 439 }
 440
 441 static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_options *options)
 442 {
 443         int counter = 0, generation = 0, name_prefix_len = 0;
 444         struct commit_list *parents;
 445         int res;
 446         int result;
 447         const char *name;
 448
 449         if (parse_commit(commit))
 450                 return -1;
 451
 452         name = get_object_name(options, &commit->object);
 453         if (name)
 454                 put_object_name(options, &get_commit_tree(commit)->object,
 455                                 "%s:", name);
 456
 457         result = options->walk((struct object *)get_commit_tree(commit),
 458                                OBJ_TREE, data, options);
 459         if (result < 0)
 460                 return result;
 461         res = result;
 462
 463         parents = commit->parents;
 464         if (name && parents) {
 465                 int len = strlen(name), power;
 466
 467                 if (len && name[len - 1] == '^') {
 468                         generation = 1;
 469                         name_prefix_len = len - 1;
 470                 }
 471                 else { /* parse ~<generation> suffix */
 472                         for (generation = 0, power = 1;
 473                              len && isdigit(name[len - 1]);
 474                              power *= 10)
 475                                 generation += power * (name[--len] - '0');
 476                         if (power > 1 && len && name[len - 1] == '~')
 477                                 name_prefix_len = len - 1;
 478                 }
 479         }
 480
 481         while (parents) {
 482                 if (name) {
 483                         struct object *obj = &parents->item->object;
 484
 485                         if (counter++)
 486                                 put_object_name(options, obj, "%s^%d",
 487                                         name, counter);
 488                         else if (generation > 0)
 489                                 put_object_name(options, obj, "%.*s~%d",
 490                                         name_prefix_len, name, generation + 1);
 491                         else
 492                                 put_object_name(options, obj, "%s^", name);
 493                 }
 494                 result = options->walk((struct object *)parents->item, OBJ_COMMIT, data, options);
 495                 if (result < 0)
 496                         return result;
 497                 if (!res)
 498                         res = result;
 499                 parents = parents->next;
 500         }
 501         return res;
 502 }
 503
 504 static int fsck_walk_tag(struct tag *tag, void *data, struct fsck_options *options)
 505 {
 506         char *name = get_object_name(options, &tag->object);
 507
 508         if (parse_tag(tag))
 509                 return -1;
 510         if (name)
 511                 put_object_name(options, tag->tagged, "%s", name);
 512         return options->walk(tag->tagged, OBJ_ANY, data, options);
 513 }
 514
 515 int fsck_walk(struct object *obj, void *data, struct fsck_options *options)
 516 {
 517         if (!obj)
 518                 return -1;
 519
 520         if (obj->type == OBJ_NONE)
 521                 parse_object(the_repository, &obj->oid);
 522
 523         switch (obj->type) {
 524         case OBJ_BLOB:
 525                 return 0;
 526         case OBJ_TREE:
 527                 return fsck_walk_tree((struct tree *)obj, data, options);
 528         case OBJ_COMMIT:
 529                 return fsck_walk_commit((struct commit *)obj, data, options);
 530         case OBJ_TAG:
 531                 return fsck_walk_tag((struct tag *)obj, data, options);
 532         default:
 533                 error("Unknown object type for %s", describe_object(options, obj));
 534                 return -1;
 535         }
 536 }
 537
 538 /*
 539  * The entries in a tree are ordered in the _path_ order,
 540  * which means that a directory entry is ordered by adding
 541  * a slash to the end of it.
 542  *
 543  * So a directory called "a" is ordered _after_ a file
 544  * called "a.c", because "a/" sorts after "a.c".
 545  */
 546 #define TREE_UNORDERED (-1)
 547 #define TREE_HAS_DUPS  (-2)
 548
 549 static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
 550 {
 551         int len1 = strlen(name1);
 552         int len2 = strlen(name2);
 553         int len = len1 < len2 ? len1 : len2;
 554         unsigned char c1, c2;
 555         int cmp;
 556
 557         cmp = memcmp(name1, name2, len);
 558         if (cmp < 0)
 559                 return 0;
 560         if (cmp > 0)
 561                 return TREE_UNORDERED;
 562
 563         /*
 564          * Ok, the first <len> characters are the same.
 565          * Now we need to order the next one, but turn
 566          * a '\0' into a '/' for a directory entry.
 567          */
 568         c1 = name1[len];
 569         c2 = name2[len];
 570         if (!c1 && !c2)
 571                 /*
 572                  * git-write-tree used to write out a nonsense tree that has
 573                  * entries with the same name, one blob and one tree.  Make
 574                  * sure we do not have duplicate entries.
 575                  */
 576                 return TREE_HAS_DUPS;
 577         if (!c1 && S_ISDIR(mode1))
 578                 c1 = '/';
 579         if (!c2 && S_ISDIR(mode2))
 580                 c2 = '/';
 581         return c1 < c2 ? 0 : TREE_UNORDERED;
 582 }
 583
 584 static int fsck_tree(struct tree *item, struct fsck_options *options)
 585 {
 586         int retval = 0;
 587         int has_null_sha1 = 0;
 588         int has_full_path = 0;
 589         int has_empty_name = 0;
 590         int has_dot = 0;
 591         int has_dotdot = 0;
 592         int has_dotgit = 0;
 593         int has_zero_pad = 0;
 594         int has_bad_modes = 0;
 595         int has_dup_entries = 0;
 596         int not_properly_sorted = 0;
 597         struct tree_desc desc;
 598         unsigned o_mode;
 599         const char *o_name;
 600
 601         if (init_tree_desc_gently(&desc, item->buffer, item->size)) {
 602                 retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
 603                 return retval;
 604         }
 605
 606         o_mode = 0;
 607         o_name = NULL;
 608
 609         while (desc.size) {
 610                 unsigned mode;
 611                 const char *name, *backslash;
 612                 const struct object_id *oid;
 613
 614                 oid = tree_entry_extract(&desc, &name, &mode);
 615
 616                 has_null_sha1 |= is_null_oid(oid);
 617                 has_full_path |= !!strchr(name, '/');
 618                 has_empty_name |= !*name;
 619                 has_dot |= !strcmp(name, ".");
 620                 has_dotdot |= !strcmp(name, "..");
 621                 has_dotgit |= is_hfs_dotgit(name) || is_ntfs_dotgit(name);
 622                 has_zero_pad |= *(char *)desc.buffer == '0';
 623
 624                 if (is_hfs_dotgitmodules(name) || is_ntfs_dotgitmodules(name)) {
 625                         if (!S_ISLNK(mode))
 626                                 oidset_insert(&gitmodules_found, oid);
 627                         else
 628                                 retval += report(options, &item->object,
 629                                                  FSCK_MSG_GITMODULES_SYMLINK,
 630                                                  ".gitmodules is a symbolic link");
 631                 }
 632
 633                 if ((backslash = strchr(name, '\\'))) {
 634                         while (backslash) {
 635                                 backslash++;
 636                                 has_dotgit |= is_ntfs_dotgit(backslash);
 637                                 if (is_ntfs_dotgitmodules(backslash)) {
 638                                         if (!S_ISLNK(mode))
 639                                                 oidset_insert(&gitmodules_found, oid);
 640                                         else
 641                                                 retval += report(options, &item->object,
 642                                                                  FSCK_MSG_GITMODULES_SYMLINK,
 643                                                                  ".gitmodules is a symbolic link");
 644                                 }
 645                                 backslash = strchr(backslash, '\\');
 646                         }
 647                 }
 648
 649                 if (update_tree_entry_gently(&desc)) {
 650                         retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
 651                         break;
 652                 }
 653
 654                 switch (mode) {
 655                 /*
 656                  * Standard modes..
 657                  */
 658                 case S_IFREG | 0755:
 659                 case S_IFREG | 0644:
 660                 case S_IFLNK:
 661                 case S_IFDIR:
 662                 case S_IFGITLINK:
 663                         break;
 664                 /*
 665                  * This is nonstandard, but we had a few of these
 666                  * early on when we honored the full set of mode
 667                  * bits..
 668                  */
 669                 case S_IFREG | 0664:
 670                         if (!options->strict)
 671                                 break;
 672                         /* fallthrough */
 673                 default:
 674                         has_bad_modes = 1;
 675                 }
 676
 677                 if (o_name) {
 678                         switch (verify_ordered(o_mode, o_name, mode, name)) {
 679                         case TREE_UNORDERED:
 680                                 not_properly_sorted = 1;
 681                                 break;
 682                         case TREE_HAS_DUPS:
 683                                 has_dup_entries = 1;
 684                                 break;
 685                         default:
 686                                 break;
 687                         }
 688                 }
 689
 690                 o_mode = mode;
 691                 o_name = name;
 692         }
 693
 694         if (has_null_sha1)
 695                 retval += report(options, &item->object, FSCK_MSG_NULL_SHA1, "contains entries pointing to null sha1");
 696         if (has_full_path)
 697                 retval += report(options, &item->object, FSCK_MSG_FULL_PATHNAME, "contains full pathnames");
 698         if (has_empty_name)
 699                 retval += report(options, &item->object, FSCK_MSG_EMPTY_NAME, "contains empty pathname");
 700         if (has_dot)
 701                 retval += report(options, &item->object, FSCK_MSG_HAS_DOT, "contains '.'");
 702         if (has_dotdot)
 703                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTDOT, "contains '..'");
 704         if (has_dotgit)
 705                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTGIT, "contains '.git'");
 706         if (has_zero_pad)
 707                 retval += report(options, &item->object, FSCK_MSG_ZERO_PADDED_FILEMODE, "contains zero-padded file modes");
 708         if (has_bad_modes)
 709                 retval += report(options, &item->object, FSCK_MSG_BAD_FILEMODE, "contains bad file modes");
 710         if (has_dup_entries)
 711                 retval += report(options, &item->object, FSCK_MSG_DUPLICATE_ENTRIES, "contains duplicate file entries");
 712         if (not_properly_sorted)
 713                 retval += report(options, &item->object, FSCK_MSG_TREE_NOT_SORTED, "not properly sorted");
 714         return retval;
 715 }
 716
 717 static int verify_headers(const void *data, unsigned long size,
 718                           struct object *obj, struct fsck_options *options)
 719 {
 720         const char *buffer = (const char *)data;
 721         unsigned long i;
 722
 723         for (i = 0; i < size; i++) {
 724                 switch (buffer[i]) {
 725                 case '\0':
 726                         return report(options, obj,
 727                                 FSCK_MSG_NUL_IN_HEADER,
 728                                 "unterminated header: NUL at offset %ld", i);
 729                 case '\n':
 730                         if (i + 1 < size && buffer[i + 1] == '\n')
 731                                 return 0;
 732                 }
 733         }
 734
 735         /*
 736          * We did not find double-LF that separates the header
 737          * and the body.  Not having a body is not a crime but
 738          * we do want to see the terminating LF for the last header
 739          * line.
 740          */
 741         if (size && buffer[size - 1] == '\n')
 742                 return 0;
 743
 744         return report(options, obj,
 745                 FSCK_MSG_UNTERMINATED_HEADER, "unterminated header");
 746 }
 747
 748 static int fsck_ident(const char **ident, struct object *obj, struct fsck_options *options)
 749 {
 750         const char *p = *ident;
 751         char *end;
 752
 753         *ident = strchrnul(*ident, '\n');
 754         if (**ident == '\n')
 755                 (*ident)++;
 756
 757         if (*p == '<')
 758                 return report(options, obj, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 759         p += strcspn(p, "<>\n");
 760         if (*p == '>')
 761                 return report(options, obj, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
 762         if (*p != '<')
 763                 return report(options, obj, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
 764         if (p[-1] != ' ')
 765                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 766         p++;
 767         p += strcspn(p, "<>\n");
 768         if (*p != '>')
 769                 return report(options, obj, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
 770         p++;
 771         if (*p != ' ')
 772                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
 773         p++;
 774         if (*p == '0' && p[1] != ' ')
 775                 return report(options, obj, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
 776         if (date_overflows(parse_timestamp(p, &end, 10)))
 777                 return report(options, obj, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
 778         if ((end == p || *end != ' '))
 779                 return report(options, obj, FSCK_MSG_BAD_DATE, "invalid author/committer line - bad date");
 780         p = end + 1;
 781         if ((*p != '+' && *p != '-') ||
 782             !isdigit(p[1]) ||
 783             !isdigit(p[2]) ||
 784             !isdigit(p[3]) ||
 785             !isdigit(p[4]) ||
 786             (p[5] != '\n'))
 787                 return report(options, obj, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
 788         p += 6;
 789         return 0;
 790 }
 791
 792 static int fsck_commit_buffer(struct commit *commit, const char *buffer,
 793         unsigned long size, struct fsck_options *options)
 794 {
 795         struct object_id tree_oid, oid;
 796         struct commit_graft *graft;
 797         unsigned parent_count, parent_line_count = 0, author_count;
 798         int err;
 799         const char *buffer_begin = buffer;
 800         const char *p;
 801
 802         if (verify_headers(buffer, size, &commit->object, options))
 803                 return -1;
 804
 805         if (!skip_prefix(buffer, "tree ", &buffer))
 806                 return report(options, &commit->object, FSCK_MSG_MISSING_TREE, "invalid format - expected 'tree' line");
 807         if (parse_oid_hex(buffer, &tree_oid, &p) || *p != '\n') {
 808                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE_SHA1, "invalid 'tree' line format - bad sha1");
 809                 if (err)
 810                         return err;
 811         }
 812         buffer = p + 1;
 813         while (skip_prefix(buffer, "parent ", &buffer)) {
 814                 if (parse_oid_hex(buffer, &oid, &p) || *p != '\n') {
 815                         err = report(options, &commit->object, FSCK_MSG_BAD_PARENT_SHA1, "invalid 'parent' line format - bad sha1");
 816                         if (err)
 817                                 return err;
 818                 }
 819                 buffer = p + 1;
 820                 parent_line_count++;
 821         }
 822         graft = lookup_commit_graft(the_repository, &commit->object.oid);
 823         parent_count = commit_list_count(commit->parents);
 824         if (graft) {
 825                 if (graft->nr_parent == -1 && !parent_count)
 826                         ; /* shallow commit */
 827                 else if (graft->nr_parent != parent_count) {
 828                         err = report(options, &commit->object, FSCK_MSG_MISSING_GRAFT, "graft objects missing");
 829                         if (err)
 830                                 return err;
 831                 }
 832         } else {
 833                 if (parent_count != parent_line_count) {
 834                         err = report(options, &commit->object, FSCK_MSG_MISSING_PARENT, "parent objects missing");
 835                         if (err)
 836                                 return err;
 837                 }
 838         }
 839         author_count = 0;
 840         while (skip_prefix(buffer, "author ", &buffer)) {
 841                 author_count++;
 842                 err = fsck_ident(&buffer, &commit->object, options);
 843                 if (err)
 844                         return err;
 845         }
 846         if (author_count < 1)
 847                 err = report(options, &commit->object, FSCK_MSG_MISSING_AUTHOR, "invalid format - expected 'author' line");
 848         else if (author_count > 1)
 849                 err = report(options, &commit->object, FSCK_MSG_MULTIPLE_AUTHORS, "invalid format - multiple 'author' lines");
 850         if (err)
 851                 return err;
 852         if (!skip_prefix(buffer, "committer ", &buffer))
 853                 return report(options, &commit->object, FSCK_MSG_MISSING_COMMITTER, "invalid format - expected 'committer' line");
 854         err = fsck_ident(&buffer, &commit->object, options);
 855         if (err)
 856                 return err;
 857         if (!get_commit_tree(commit)) {
 858                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE, "could not load commit's tree %s", oid_to_hex(&tree_oid));
 859                 if (err)
 860                         return err;
 861         }
 862         if (memchr(buffer_begin, '\0', size)) {
 863                 err = report(options, &commit->object, FSCK_MSG_NUL_IN_COMMIT,
 864                              "NUL byte in the commit object body");
 865                 if (err)
 866                         return err;
 867         }
 868         return 0;
 869 }
 870
 871 static int fsck_commit(struct commit *commit, const char *data,
 872         unsigned long size, struct fsck_options *options)
 873 {
 874         const char *buffer = data ?  data : get_commit_buffer(commit, &size);
 875         int ret = fsck_commit_buffer(commit, buffer, size, options);
 876         if (!data)
 877                 unuse_commit_buffer(commit, buffer);
 878         return ret;
 879 }
 880
 881 static int fsck_tag_buffer(struct tag *tag, const char *data,
 882         unsigned long size, struct fsck_options *options)
 883 {
 884         struct object_id oid;
 885         int ret = 0;
 886         const char *buffer;
 887         char *to_free = NULL, *eol;
 888         struct strbuf sb = STRBUF_INIT;
 889         const char *p;
 890
 891         if (data)
 892                 buffer = data;
 893         else {
 894                 enum object_type type;
 895
 896                 buffer = to_free =
 897                         read_object_file(&tag->object.oid, &type, &size);
 898                 if (!buffer)
 899                         return report(options, &tag->object,
 900                                 FSCK_MSG_MISSING_TAG_OBJECT,
 901                                 "cannot read tag object");
 902
 903                 if (type != OBJ_TAG) {
 904                         ret = report(options, &tag->object,
 905                                 FSCK_MSG_TAG_OBJECT_NOT_TAG,
 906                                 "expected tag got %s",
 907                             type_name(type));
 908                         goto done;
 909                 }
 910         }
 911
 912         ret = verify_headers(buffer, size, &tag->object, options);
 913         if (ret)
 914                 goto done;
 915
 916         if (!skip_prefix(buffer, "object ", &buffer)) {
 917                 ret = report(options, &tag->object, FSCK_MSG_MISSING_OBJECT, "invalid format - expected 'object' line");
 918                 goto done;
 919         }
 920         if (parse_oid_hex(buffer, &oid, &p) || *p != '\n') {
 921                 ret = report(options, &tag->object, FSCK_MSG_BAD_OBJECT_SHA1, "invalid 'object' line format - bad sha1");
 922                 if (ret)
 923                         goto done;
 924         }
 925         buffer = p + 1;
 926
 927         if (!skip_prefix(buffer, "type ", &buffer)) {
 928                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE_ENTRY, "invalid format - expected 'type' line");
 929                 goto done;
 930         }
 931         eol = strchr(buffer, '\n');
 932         if (!eol) {
 933                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE, "invalid format - unexpected end after 'type' line");
 934                 goto done;
 935         }
 936         if (type_from_string_gently(buffer, eol - buffer, 1) < 0)
 937                 ret = report(options, &tag->object, FSCK_MSG_BAD_TYPE, "invalid 'type' value");
 938         if (ret)
 939                 goto done;
 940         buffer = eol + 1;
 941
 942         if (!skip_prefix(buffer, "tag ", &buffer)) {
 943                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG_ENTRY, "invalid format - expected 'tag' line");
 944                 goto done;
 945         }
 946         eol = strchr(buffer, '\n');
 947         if (!eol) {
 948                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG, "invalid format - unexpected end after 'type' line");
 949                 goto done;
 950         }
 951         strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer);
 952         if (check_refname_format(sb.buf, 0)) {
 953                 ret = report(options, &tag->object, FSCK_MSG_BAD_TAG_NAME,
 954                            "invalid 'tag' name: %.*s",
 955                            (int)(eol - buffer), buffer);
 956                 if (ret)
 957                         goto done;
 958         }
 959         buffer = eol + 1;
 960
 961         if (!skip_prefix(buffer, "tagger ", &buffer)) {
 962                 /* early tags do not contain 'tagger' lines; warn only */
 963                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
 964                 if (ret)
 965                         goto done;
 966         }
 967         else
 968                 ret = fsck_ident(&buffer, &tag->object, options);
 969
 970 done:
 971         strbuf_release(&sb);
 972         free(to_free);
 973         return ret;
 974 }
 975
 976 static int fsck_tag(struct tag *tag, const char *data,
 977         unsigned long size, struct fsck_options *options)
 978 {
 979         struct object *tagged = tag->tagged;
 980
 981         if (!tagged)
 982                 return report(options, &tag->object, FSCK_MSG_BAD_TAG_OBJECT, "could not load tagged object");
 983
 984         return fsck_tag_buffer(tag, data, size, options);
 985 }
 986
 987 /*
 988  * Like builtin/submodule--helper.c's starts_with_dot_slash, but without
 989  * relying on the platform-dependent is_dir_sep helper.
 990  *
 991  * This is for use in checking whether a submodule URL is interpreted as
 992  * relative to the current directory on any platform, since \ is a
 993  * directory separator on Windows but not on other platforms.
 994  */
 995 static int starts_with_dot_slash(const char *str)
 996 {
 997         return str[0] == '.' && (str[1] == '/' || str[1] == '\\');
 998 }
 999
1000 /*
1001  * Like starts_with_dot_slash, this is a variant of submodule--helper's
1002  * helper of the same name with the twist that it accepts backslash as a
1003  * directory separator even on non-Windows platforms.
1004  */
1005 static int starts_with_dot_dot_slash(const char *str)
1006 {
1007         return str[0] == '.' && starts_with_dot_slash(str + 1);
1008 }
1009
1010 static int submodule_url_is_relative(const char *url)
1011 {
1012         return starts_with_dot_slash(url) || starts_with_dot_dot_slash(url);
1013 }
1014
1015 /*
1016  * Count directory components that a relative submodule URL should chop
1017  * from the remote_url it is to be resolved against.
1018  *
1019  * In other words, this counts "../" components at the start of a
1020  * submodule URL.
1021  *
1022  * Returns the number of directory components to chop and writes a
1023  * pointer to the next character of url after all leading "./" and
1024  * "../" components to out.
1025  */
1026 static int count_leading_dotdots(const char *url, const char **out)
1027 {
1028         int result = 0;
1029         while (1) {
1030                 if (starts_with_dot_dot_slash(url)) {
1031                         result++;
1032                         url += strlen("../");
1033                         continue;
1034                 }
1035                 if (starts_with_dot_slash(url)) {
1036                         url += strlen("./");
1037                         continue;
1038                 }
1039                 *out = url;
1040                 return result;
1041         }
1042 }
1043 /*
1044  * Check whether a transport is implemented by git-remote-curl.
1045  *
1046  * If it is, returns 1 and writes the URL that would be passed to
1047  * git-remote-curl to the "out" parameter.
1048  *
1049  * Otherwise, returns 0 and leaves "out" untouched.
1050  *
1051  * Examples:
1052  *   http::https://example.com/repo.git -> 1, https://example.com/repo.git
1053  *   https://example.com/repo.git -> 1, https://example.com/repo.git
1054  *   git://example.com/repo.git -> 0
1055  *
1056  * This is for use in checking for previously exploitable bugs that
1057  * required a submodule URL to be passed to git-remote-curl.
1058  */
1059 static int url_to_curl_url(const char *url, const char **out)
1060 {
1061         /*
1062          * We don't need to check for case-aliases, "http.exe", and so
1063          * on because in the default configuration, is_transport_allowed
1064          * prevents URLs with those schemes from being cloned
1065          * automatically.
1066          */
1067         if (skip_prefix(url, "http::", out) ||
1068             skip_prefix(url, "https::", out) ||
1069             skip_prefix(url, "ftp::", out) ||
1070             skip_prefix(url, "ftps::", out))
1071                 return 1;
1072         if (starts_with(url, "http://") ||
1073             starts_with(url, "https://") ||
1074             starts_with(url, "ftp://") ||
1075             starts_with(url, "ftps://")) {
1076                 *out = url;
1077                 return 1;
1078         }
1079         return 0;
1080 }
1081
1082 static int check_submodule_url(const char *url)
1083 {
1084         const char *curl_url;
1085
1086         if (looks_like_command_line_option(url))
1087                 return -1;
1088
1089         if (submodule_url_is_relative(url)) {
1090                 char *decoded;
1091                 const char *next;
1092                 int has_nl;
1093
1094                 /*
1095                  * This could be appended to an http URL and url-decoded;
1096                  * check for malicious characters.
1097                  */
1098                 decoded = url_decode(url);
1099                 has_nl = !!strchr(decoded, '\n');
1100
1101                 free(decoded);
1102                 if (has_nl)
1103                         return -1;
1104
1105                 /*
1106                  * URLs which escape their root via "../" can overwrite
1107                  * the host field and previous components, resolving to
1108                  * URLs like https::example.com/submodule.git and
1109                  * https:///example.com/submodule.git that were
1110                  * susceptible to CVE-2020-11008.
1111                  */
1112                 if (count_leading_dotdots(url, &next) > 0 &&
1113                     (*next == ':' || *next == '/'))
1114                         return -1;
1115         }
1116
1117         else if (url_to_curl_url(url, &curl_url)) {
1118                 struct credential c = CREDENTIAL_INIT;
1119                 int ret = 0;
1120                 if (credential_from_url_gently(&c, curl_url, 1) ||
1121                     !*c.host)
1122                         ret = -1;
1123                 credential_clear(&c);
1124                 return ret;
1125         }
1126
1127         return 0;
1128 }
1129
1130 struct fsck_gitmodules_data {
1131         struct object *obj;
1132         struct fsck_options *options;
1133         int ret;
1134 };
1135
1136 static int fsck_gitmodules_fn(const char *var, const char *value, void *vdata)
1137 {
1138         struct fsck_gitmodules_data *data = vdata;
1139         const char *subsection, *key;
1140         int subsection_len;
1141         char *name;
1142
1143         if (parse_config_key(var, "submodule", &subsection, &subsection_len, &key) < 0 ||
1144             !subsection)
1145                 return 0;
1146
1147         name = xmemdupz(subsection, subsection_len);
1148         if (check_submodule_name(name) < 0)
1149                 data->ret |= report(data->options, data->obj,
1150                                     FSCK_MSG_GITMODULES_NAME,
1151                                     "disallowed submodule name: %s",
1152                                     name);
1153         if (!strcmp(key, "url") && value &&
1154             check_submodule_url(value) < 0)
1155                 data->ret |= report(data->options, data->obj,
1156                                     FSCK_MSG_GITMODULES_URL,
1157                                     "disallowed submodule url: %s",
1158                                     value);
1159         if (!strcmp(key, "path") && value &&
1160             looks_like_command_line_option(value))
1161                 data->ret |= report(data->options, data->obj,
1162                                     FSCK_MSG_GITMODULES_PATH,
1163                                     "disallowed submodule path: %s",
1164                                     value);
1165         if (!strcmp(key, "update") && value &&
1166             parse_submodule_update_type(value) == SM_UPDATE_COMMAND)
1167                 data->ret |= report(data->options, data->obj,
1168                                     FSCK_MSG_GITMODULES_UPDATE,
1169                                     "disallowed submodule update setting: %s",
1170                                     value);
1171         free(name);
1172
1173         return 0;
1174 }
1175
1176 static int fsck_blob(struct blob *blob, const char *buf,
1177                      unsigned long size, struct fsck_options *options)
1178 {
1179         struct fsck_gitmodules_data data;
1180         struct config_options config_opts = { 0 };
1181
1182         if (!oidset_contains(&gitmodules_found, &blob->object.oid))
1183                 return 0;
1184         oidset_insert(&gitmodules_done, &blob->object.oid);
1185
1186         if (object_on_skiplist(options, &blob->object))
1187                 return 0;
1188
1189         if (!buf) {
1190                 /*
1191                  * A missing buffer here is a sign that the caller found the
1192                  * blob too gigantic to load into memory. Let's just consider
1193                  * that an error.
1194                  */
1195                 return report(options, &blob->object,
1196                               FSCK_MSG_GITMODULES_LARGE,
1197                               ".gitmodules too large to parse");
1198         }
1199
1200         data.obj = &blob->object;
1201         data.options = options;
1202         data.ret = 0;
1203         config_opts.error_action = CONFIG_ERROR_SILENT;
1204         if (git_config_from_mem(fsck_gitmodules_fn, CONFIG_ORIGIN_BLOB,
1205                                 ".gitmodules", buf, size, &data, &config_opts))
1206                 data.ret |= report(options, &blob->object,
1207                                    FSCK_MSG_GITMODULES_PARSE,
1208                                    "could not parse gitmodules blob");
1209
1210         return data.ret;
1211 }
1212
1213 int fsck_object(struct object *obj, void *data, unsigned long size,
1214         struct fsck_options *options)
1215 {
1216         if (!obj)
1217                 return report(options, obj, FSCK_MSG_BAD_OBJECT_SHA1, "no valid object to fsck");
1218
1219         if (obj->type == OBJ_BLOB)
1220                 return fsck_blob((struct blob *)obj, data, size, options);
1221         if (obj->type == OBJ_TREE)
1222                 return fsck_tree((struct tree *) obj, options);
1223         if (obj->type == OBJ_COMMIT)
1224                 return fsck_commit((struct commit *) obj, (const char *) data,
1225                         size, options);
1226         if (obj->type == OBJ_TAG)
1227                 return fsck_tag((struct tag *) obj, (const char *) data,
1228                         size, options);
1229
1230         return report(options, obj, FSCK_MSG_UNKNOWN_TYPE, "unknown type '%d' (internal fsck error)",
1231                           obj->type);
1232 }
1233
1234 int fsck_error_function(struct fsck_options *o,
1235         struct object *obj, int msg_type, const char *message)
1236 {
1237         if (msg_type == FSCK_WARN) {
1238                 warning("object %s: %s", describe_object(o, obj), message);
1239                 return 0;
1240         }
1241         error("object %s: %s", describe_object(o, obj), message);
1242         return 1;
1243 }
1244
1245 int fsck_finish(struct fsck_options *options)
1246 {
1247         int ret = 0;
1248         struct oidset_iter iter;
1249         const struct object_id *oid;
1250
1251         oidset_iter_init(&gitmodules_found, &iter);
1252         while ((oid = oidset_iter_next(&iter))) {
1253                 struct blob *blob;
1254                 enum object_type type;
1255                 unsigned long size;
1256                 char *buf;
1257
1258                 if (oidset_contains(&gitmodules_done, oid))
1259                         continue;
1260
1261                 blob = lookup_blob(the_repository, oid);
1262                 if (!blob) {
1263                         struct object *obj = lookup_unknown_object(oid->hash);
1264                         ret |= report(options, obj,
1265                                       FSCK_MSG_GITMODULES_BLOB,
1266                                       "non-blob found at .gitmodules");
1267                         continue;
1268                 }
1269
1270                 buf = read_object_file(oid, &type, &size);
1271                 if (!buf) {
1272                         if (is_promisor_object(&blob->object.oid))
1273                                 continue;
1274                         ret |= report(options, &blob->object,
1275                                       FSCK_MSG_GITMODULES_MISSING,
1276                                       "unable to read .gitmodules blob");
1277                         continue;
1278                 }
1279
1280                 if (type == OBJ_BLOB)
1281                         ret |= fsck_blob(blob, buf, size, options);
1282                 else
1283                         ret |= report(options, &blob->object,
1284                                       FSCK_MSG_GITMODULES_BLOB,
1285                                       "non-blob found at .gitmodules");
1286                 free(buf);
1287         }
1288
1289
1290         oidset_clear(&gitmodules_found);
1291         oidset_clear(&gitmodules_done);
1292         return ret;
1293 }