fsck.c

   1 #include "cache.h"
   2 #include "object.h"
   3 #include "blob.h"
   4 #include "tree.h"
   5 #include "tree-walk.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "fsck.h"
   9 #include "refs.h"
  10 #include "url.h"
  11 #include "utf8.h"
  12 #include "sha1-array.h"
  13 #include "decorate.h"
  14 #include "oidset.h"
  15 #include "packfile.h"
  16 #include "submodule-config.h"
  17 #include "config.h"
  18 #include "credential.h"
  19
  20 static struct oidset gitmodules_found = OIDSET_INIT;
  21 static struct oidset gitmodules_done = OIDSET_INIT;
  22
  23 #define FSCK_FATAL -1
  24 #define FSCK_INFO -2
  25
  26 #define FOREACH_MSG_ID(FUNC) \
  27         /* fatal errors */ \
  28         FUNC(NUL_IN_HEADER, FATAL) \
  29         FUNC(UNTERMINATED_HEADER, FATAL) \
  30         /* errors */ \
  31         FUNC(BAD_DATE, ERROR) \
  32         FUNC(BAD_DATE_OVERFLOW, ERROR) \
  33         FUNC(BAD_EMAIL, ERROR) \
  34         FUNC(BAD_NAME, ERROR) \
  35         FUNC(BAD_OBJECT_SHA1, ERROR) \
  36         FUNC(BAD_PARENT_SHA1, ERROR) \
  37         FUNC(BAD_TAG_OBJECT, ERROR) \
  38         FUNC(BAD_TIMEZONE, ERROR) \
  39         FUNC(BAD_TREE, ERROR) \
  40         FUNC(BAD_TREE_SHA1, ERROR) \
  41         FUNC(BAD_TYPE, ERROR) \
  42         FUNC(DUPLICATE_ENTRIES, ERROR) \
  43         FUNC(MISSING_AUTHOR, ERROR) \
  44         FUNC(MISSING_COMMITTER, ERROR) \
  45         FUNC(MISSING_EMAIL, ERROR) \
  46         FUNC(MISSING_GRAFT, ERROR) \
  47         FUNC(MISSING_NAME_BEFORE_EMAIL, ERROR) \
  48         FUNC(MISSING_OBJECT, ERROR) \
  49         FUNC(MISSING_PARENT, ERROR) \
  50         FUNC(MISSING_SPACE_BEFORE_DATE, ERROR) \
  51         FUNC(MISSING_SPACE_BEFORE_EMAIL, ERROR) \
  52         FUNC(MISSING_TAG, ERROR) \
  53         FUNC(MISSING_TAG_ENTRY, ERROR) \
  54         FUNC(MISSING_TAG_OBJECT, ERROR) \
  55         FUNC(MISSING_TREE, ERROR) \
  56         FUNC(MISSING_TREE_OBJECT, ERROR) \
  57         FUNC(MISSING_TYPE, ERROR) \
  58         FUNC(MISSING_TYPE_ENTRY, ERROR) \
  59         FUNC(MULTIPLE_AUTHORS, ERROR) \
  60         FUNC(TAG_OBJECT_NOT_TAG, ERROR) \
  61         FUNC(TREE_NOT_SORTED, ERROR) \
  62         FUNC(UNKNOWN_TYPE, ERROR) \
  63         FUNC(ZERO_PADDED_DATE, ERROR) \
  64         FUNC(GITMODULES_MISSING, ERROR) \
  65         FUNC(GITMODULES_BLOB, ERROR) \
  66         FUNC(GITMODULES_PARSE, ERROR) \
  67         FUNC(GITMODULES_NAME, ERROR) \
  68         FUNC(GITMODULES_SYMLINK, ERROR) \
  69         FUNC(GITMODULES_URL, ERROR) \
  70         FUNC(GITMODULES_PATH, ERROR) \
  71         FUNC(GITMODULES_UPDATE, ERROR) \
  72         /* warnings */ \
  73         FUNC(BAD_FILEMODE, WARN) \
  74         FUNC(EMPTY_NAME, WARN) \
  75         FUNC(FULL_PATHNAME, WARN) \
  76         FUNC(HAS_DOT, WARN) \
  77         FUNC(HAS_DOTDOT, WARN) \
  78         FUNC(HAS_DOTGIT, WARN) \
  79         FUNC(NULL_SHA1, WARN) \
  80         FUNC(ZERO_PADDED_FILEMODE, WARN) \
  81         FUNC(NUL_IN_COMMIT, WARN) \
  82         /* infos (reported as warnings, but ignored by default) */ \
  83         FUNC(BAD_TAG_NAME, INFO) \
  84         FUNC(MISSING_TAGGER_ENTRY, INFO)
  85
  86 #define MSG_ID(id, msg_type) FSCK_MSG_##id,
  87 enum fsck_msg_id {
  88         FOREACH_MSG_ID(MSG_ID)
  89         FSCK_MSG_MAX
  90 };
  91 #undef MSG_ID
  92
  93 #define STR(x) #x
  94 #define MSG_ID(id, msg_type) { STR(id), NULL, FSCK_##msg_type },
  95 static struct {
  96         const char *id_string;
  97         const char *downcased;
  98         int msg_type;
  99 } msg_id_info[FSCK_MSG_MAX + 1] = {
 100         FOREACH_MSG_ID(MSG_ID)
 101         { NULL, NULL, -1 }
 102 };
 103 #undef MSG_ID
 104
 105 static int parse_msg_id(const char *text)
 106 {
 107         int i;
 108
 109         if (!msg_id_info[0].downcased) {
 110                 /* convert id_string to lower case, without underscores. */
 111                 for (i = 0; i < FSCK_MSG_MAX; i++) {
 112                         const char *p = msg_id_info[i].id_string;
 113                         int len = strlen(p);
 114                         char *q = xmalloc(len);
 115
 116                         msg_id_info[i].downcased = q;
 117                         while (*p)
 118                                 if (*p == '_')
 119                                         p++;
 120                                 else
 121                                         *(q)++ = tolower(*(p)++);
 122                         *q = '\0';
 123                 }
 124         }
 125
 126         for (i = 0; i < FSCK_MSG_MAX; i++)
 127                 if (!strcmp(text, msg_id_info[i].downcased))
 128                         return i;
 129
 130         return -1;
 131 }
 132
 133 static int fsck_msg_type(enum fsck_msg_id msg_id,
 134         struct fsck_options *options)
 135 {
 136         int msg_type;
 137
 138         assert(msg_id >= 0 && msg_id < FSCK_MSG_MAX);
 139
 140         if (options->msg_type)
 141                 msg_type = options->msg_type[msg_id];
 142         else {
 143                 msg_type = msg_id_info[msg_id].msg_type;
 144                 if (options->strict && msg_type == FSCK_WARN)
 145                         msg_type = FSCK_ERROR;
 146         }
 147
 148         return msg_type;
 149 }
 150
 151 static void init_skiplist(struct fsck_options *options, const char *path)
 152 {
 153         static struct oid_array skiplist = OID_ARRAY_INIT;
 154         int sorted, fd;
 155         char buffer[GIT_MAX_HEXSZ + 1];
 156         struct object_id oid;
 157
 158         if (options->skiplist)
 159                 sorted = options->skiplist->sorted;
 160         else {
 161                 sorted = 1;
 162                 options->skiplist = &skiplist;
 163         }
 164
 165         fd = open(path, O_RDONLY);
 166         if (fd < 0)
 167                 die("Could not open skip list: %s", path);
 168         for (;;) {
 169                 const char *p;
 170                 int result = read_in_full(fd, buffer, sizeof(buffer));
 171                 if (result < 0)
 172                         die_errno("Could not read '%s'", path);
 173                 if (!result)
 174                         break;
 175                 if (parse_oid_hex(buffer, &oid, &p) || *p != '\n')
 176                         die("Invalid SHA-1: %s", buffer);
 177                 oid_array_append(&skiplist, &oid);
 178                 if (sorted && skiplist.nr > 1 &&
 179                                 oidcmp(&skiplist.oid[skiplist.nr - 2],
 180                                        &oid) > 0)
 181                         sorted = 0;
 182         }
 183         close(fd);
 184
 185         if (sorted)
 186                 skiplist.sorted = 1;
 187 }
 188
 189 static int parse_msg_type(const char *str)
 190 {
 191         if (!strcmp(str, "error"))
 192                 return FSCK_ERROR;
 193         else if (!strcmp(str, "warn"))
 194                 return FSCK_WARN;
 195         else if (!strcmp(str, "ignore"))
 196                 return FSCK_IGNORE;
 197         else
 198                 die("Unknown fsck message type: '%s'", str);
 199 }
 200
 201 int is_valid_msg_type(const char *msg_id, const char *msg_type)
 202 {
 203         if (parse_msg_id(msg_id) < 0)
 204                 return 0;
 205         parse_msg_type(msg_type);
 206         return 1;
 207 }
 208
 209 void fsck_set_msg_type(struct fsck_options *options,
 210                 const char *msg_id, const char *msg_type)
 211 {
 212         int id = parse_msg_id(msg_id), type;
 213
 214         if (id < 0)
 215                 die("Unhandled message id: %s", msg_id);
 216         type = parse_msg_type(msg_type);
 217
 218         if (type != FSCK_ERROR && msg_id_info[id].msg_type == FSCK_FATAL)
 219                 die("Cannot demote %s to %s", msg_id, msg_type);
 220
 221         if (!options->msg_type) {
 222                 int i;
 223                 int *msg_type;
 224                 ALLOC_ARRAY(msg_type, FSCK_MSG_MAX);
 225                 for (i = 0; i < FSCK_MSG_MAX; i++)
 226                         msg_type[i] = fsck_msg_type(i, options);
 227                 options->msg_type = msg_type;
 228         }
 229
 230         options->msg_type[id] = type;
 231 }
 232
 233 void fsck_set_msg_types(struct fsck_options *options, const char *values)
 234 {
 235         char *buf = xstrdup(values), *to_free = buf;
 236         int done = 0;
 237
 238         while (!done) {
 239                 int len = strcspn(buf, " ,|"), equal;
 240
 241                 done = !buf[len];
 242                 if (!len) {
 243                         buf++;
 244                         continue;
 245                 }
 246                 buf[len] = '\0';
 247
 248                 for (equal = 0;
 249                      equal < len && buf[equal] != '=' && buf[equal] != ':';
 250                      equal++)
 251                         buf[equal] = tolower(buf[equal]);
 252                 buf[equal] = '\0';
 253
 254                 if (!strcmp(buf, "skiplist")) {
 255                         if (equal == len)
 256                                 die("skiplist requires a path");
 257                         init_skiplist(options, buf + equal + 1);
 258                         buf += len + 1;
 259                         continue;
 260                 }
 261
 262                 if (equal == len)
 263                         die("Missing '=': '%s'", buf);
 264
 265                 fsck_set_msg_type(options, buf, buf + equal + 1);
 266                 buf += len + 1;
 267         }
 268         free(to_free);
 269 }
 270
 271 static void append_msg_id(struct strbuf *sb, const char *msg_id)
 272 {
 273         for (;;) {
 274                 char c = *(msg_id)++;
 275
 276                 if (!c)
 277                         break;
 278                 if (c != '_')
 279                         strbuf_addch(sb, tolower(c));
 280                 else {
 281                         assert(*msg_id);
 282                         strbuf_addch(sb, *(msg_id)++);
 283                 }
 284         }
 285
 286         strbuf_addstr(sb, ": ");
 287 }
 288
 289 __attribute__((format (printf, 4, 5)))
 290 static int report(struct fsck_options *options, struct object *object,
 291         enum fsck_msg_id id, const char *fmt, ...)
 292 {
 293         va_list ap;
 294         struct strbuf sb = STRBUF_INIT;
 295         int msg_type = fsck_msg_type(id, options), result;
 296
 297         if (msg_type == FSCK_IGNORE)
 298                 return 0;
 299
 300         if (options->skiplist && object &&
 301                         oid_array_lookup(options->skiplist, &object->oid) >= 0)
 302                 return 0;
 303
 304         if (msg_type == FSCK_FATAL)
 305                 msg_type = FSCK_ERROR;
 306         else if (msg_type == FSCK_INFO)
 307                 msg_type = FSCK_WARN;
 308
 309         append_msg_id(&sb, msg_id_info[id].id_string);
 310
 311         va_start(ap, fmt);
 312         strbuf_vaddf(&sb, fmt, ap);
 313         result = options->error_func(options, object, msg_type, sb.buf);
 314         strbuf_release(&sb);
 315         va_end(ap);
 316
 317         return result;
 318 }
 319
 320 static char *get_object_name(struct fsck_options *options, struct object *obj)
 321 {
 322         if (!options->object_names)
 323                 return NULL;
 324         return lookup_decoration(options->object_names, obj);
 325 }
 326
 327 static void put_object_name(struct fsck_options *options, struct object *obj,
 328         const char *fmt, ...)
 329 {
 330         va_list ap;
 331         struct strbuf buf = STRBUF_INIT;
 332         char *existing;
 333
 334         if (!options->object_names)
 335                 return;
 336         existing = lookup_decoration(options->object_names, obj);
 337         if (existing)
 338                 return;
 339         va_start(ap, fmt);
 340         strbuf_vaddf(&buf, fmt, ap);
 341         add_decoration(options->object_names, obj, strbuf_detach(&buf, NULL));
 342         va_end(ap);
 343 }
 344
 345 static const char *describe_object(struct fsck_options *o, struct object *obj)
 346 {
 347         static struct strbuf buf = STRBUF_INIT;
 348         char *name;
 349
 350         strbuf_reset(&buf);
 351         strbuf_addstr(&buf, oid_to_hex(&obj->oid));
 352         if (o->object_names && (name = lookup_decoration(o->object_names, obj)))
 353                 strbuf_addf(&buf, " (%s)", name);
 354
 355         return buf.buf;
 356 }
 357
 358 static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *options)
 359 {
 360         struct tree_desc desc;
 361         struct name_entry entry;
 362         int res = 0;
 363         const char *name;
 364
 365         if (parse_tree(tree))
 366                 return -1;
 367
 368         name = get_object_name(options, &tree->object);
 369         if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
 370                 return -1;
 371         while (tree_entry_gently(&desc, &entry)) {
 372                 struct object *obj;
 373                 int result;
 374
 375                 if (S_ISGITLINK(entry.mode))
 376                         continue;
 377
 378                 if (S_ISDIR(entry.mode)) {
 379                         obj = (struct object *)lookup_tree(entry.oid);
 380                         if (name && obj)
 381                                 put_object_name(options, obj, "%s%s/", name,
 382                                         entry.path);
 383                         result = options->walk(obj, OBJ_TREE, data, options);
 384                 }
 385                 else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode)) {
 386                         obj = (struct object *)lookup_blob(entry.oid);
 387                         if (name && obj)
 388                                 put_object_name(options, obj, "%s%s", name,
 389                                         entry.path);
 390                         result = options->walk(obj, OBJ_BLOB, data, options);
 391                 }
 392                 else {
 393                         result = error("in tree %s: entry %s has bad mode %.6o",
 394                                         describe_object(options, &tree->object), entry.path, entry.mode);
 395                 }
 396                 if (result < 0)
 397                         return result;
 398                 if (!res)
 399                         res = result;
 400         }
 401         return res;
 402 }
 403
 404 static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_options *options)
 405 {
 406         int counter = 0, generation = 0, name_prefix_len = 0;
 407         struct commit_list *parents;
 408         int res;
 409         int result;
 410         const char *name;
 411
 412         if (parse_commit(commit))
 413                 return -1;
 414
 415         name = get_object_name(options, &commit->object);
 416         if (name)
 417                 put_object_name(options, &commit->tree->object, "%s:", name);
 418
 419         result = options->walk((struct object *)commit->tree, OBJ_TREE, data, options);
 420         if (result < 0)
 421                 return result;
 422         res = result;
 423
 424         parents = commit->parents;
 425         if (name && parents) {
 426                 int len = strlen(name), power;
 427
 428                 if (len && name[len - 1] == '^') {
 429                         generation = 1;
 430                         name_prefix_len = len - 1;
 431                 }
 432                 else { /* parse ~<generation> suffix */
 433                         for (generation = 0, power = 1;
 434                              len && isdigit(name[len - 1]);
 435                              power *= 10)
 436                                 generation += power * (name[--len] - '0');
 437                         if (power > 1 && len && name[len - 1] == '~')
 438                                 name_prefix_len = len - 1;
 439                 }
 440         }
 441
 442         while (parents) {
 443                 if (name) {
 444                         struct object *obj = &parents->item->object;
 445
 446                         if (++counter > 1)
 447                                 put_object_name(options, obj, "%s^%d",
 448                                         name, counter);
 449                         else if (generation > 0)
 450                                 put_object_name(options, obj, "%.*s~%d",
 451                                         name_prefix_len, name, generation + 1);
 452                         else
 453                                 put_object_name(options, obj, "%s^", name);
 454                 }
 455                 result = options->walk((struct object *)parents->item, OBJ_COMMIT, data, options);
 456                 if (result < 0)
 457                         return result;
 458                 if (!res)
 459                         res = result;
 460                 parents = parents->next;
 461         }
 462         return res;
 463 }
 464
 465 static int fsck_walk_tag(struct tag *tag, void *data, struct fsck_options *options)
 466 {
 467         char *name = get_object_name(options, &tag->object);
 468
 469         if (parse_tag(tag))
 470                 return -1;
 471         if (name)
 472                 put_object_name(options, tag->tagged, "%s", name);
 473         return options->walk(tag->tagged, OBJ_ANY, data, options);
 474 }
 475
 476 int fsck_walk(struct object *obj, void *data, struct fsck_options *options)
 477 {
 478         if (!obj)
 479                 return -1;
 480
 481         if (obj->type == OBJ_NONE)
 482                 parse_object(&obj->oid);
 483
 484         switch (obj->type) {
 485         case OBJ_BLOB:
 486                 return 0;
 487         case OBJ_TREE:
 488                 return fsck_walk_tree((struct tree *)obj, data, options);
 489         case OBJ_COMMIT:
 490                 return fsck_walk_commit((struct commit *)obj, data, options);
 491         case OBJ_TAG:
 492                 return fsck_walk_tag((struct tag *)obj, data, options);
 493         default:
 494                 error("Unknown object type for %s", describe_object(options, obj));
 495                 return -1;
 496         }
 497 }
 498
 499 /*
 500  * The entries in a tree are ordered in the _path_ order,
 501  * which means that a directory entry is ordered by adding
 502  * a slash to the end of it.
 503  *
 504  * So a directory called "a" is ordered _after_ a file
 505  * called "a.c", because "a/" sorts after "a.c".
 506  */
 507 #define TREE_UNORDERED (-1)
 508 #define TREE_HAS_DUPS  (-2)
 509
 510 static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
 511 {
 512         int len1 = strlen(name1);
 513         int len2 = strlen(name2);
 514         int len = len1 < len2 ? len1 : len2;
 515         unsigned char c1, c2;
 516         int cmp;
 517
 518         cmp = memcmp(name1, name2, len);
 519         if (cmp < 0)
 520                 return 0;
 521         if (cmp > 0)
 522                 return TREE_UNORDERED;
 523
 524         /*
 525          * Ok, the first <len> characters are the same.
 526          * Now we need to order the next one, but turn
 527          * a '\0' into a '/' for a directory entry.
 528          */
 529         c1 = name1[len];
 530         c2 = name2[len];
 531         if (!c1 && !c2)
 532                 /*
 533                  * git-write-tree used to write out a nonsense tree that has
 534                  * entries with the same name, one blob and one tree.  Make
 535                  * sure we do not have duplicate entries.
 536                  */
 537                 return TREE_HAS_DUPS;
 538         if (!c1 && S_ISDIR(mode1))
 539                 c1 = '/';
 540         if (!c2 && S_ISDIR(mode2))
 541                 c2 = '/';
 542         return c1 < c2 ? 0 : TREE_UNORDERED;
 543 }
 544
 545 static int fsck_tree(struct tree *item, struct fsck_options *options)
 546 {
 547         int retval = 0;
 548         int has_null_sha1 = 0;
 549         int has_full_path = 0;
 550         int has_empty_name = 0;
 551         int has_dot = 0;
 552         int has_dotdot = 0;
 553         int has_dotgit = 0;
 554         int has_zero_pad = 0;
 555         int has_bad_modes = 0;
 556         int has_dup_entries = 0;
 557         int not_properly_sorted = 0;
 558         struct tree_desc desc;
 559         unsigned o_mode;
 560         const char *o_name;
 561
 562         if (init_tree_desc_gently(&desc, item->buffer, item->size)) {
 563                 retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
 564                 return retval;
 565         }
 566
 567         o_mode = 0;
 568         o_name = NULL;
 569
 570         while (desc.size) {
 571                 unsigned mode;
 572                 const char *name, *backslash;
 573                 const struct object_id *oid;
 574
 575                 oid = tree_entry_extract(&desc, &name, &mode);
 576
 577                 has_null_sha1 |= is_null_oid(oid);
 578                 has_full_path |= !!strchr(name, '/');
 579                 has_empty_name |= !*name;
 580                 has_dot |= !strcmp(name, ".");
 581                 has_dotdot |= !strcmp(name, "..");
 582                 has_dotgit |= is_hfs_dotgit(name) || is_ntfs_dotgit(name);
 583                 has_zero_pad |= *(char *)desc.buffer == '0';
 584
 585                 if (is_hfs_dotgitmodules(name) || is_ntfs_dotgitmodules(name)) {
 586                         if (!S_ISLNK(mode))
 587                                 oidset_insert(&gitmodules_found, oid);
 588                         else
 589                                 retval += report(options, &item->object,
 590                                                  FSCK_MSG_GITMODULES_SYMLINK,
 591                                                  ".gitmodules is a symbolic link");
 592                 }
 593
 594                 if ((backslash = strchr(name, '\\'))) {
 595                         while (backslash) {
 596                                 backslash++;
 597                                 has_dotgit |= is_ntfs_dotgit(backslash);
 598                                 if (is_ntfs_dotgitmodules(backslash)) {
 599                                         if (!S_ISLNK(mode))
 600                                                 oidset_insert(&gitmodules_found, oid);
 601                                         else
 602                                                 retval += report(options, &item->object,
 603                                                                  FSCK_MSG_GITMODULES_SYMLINK,
 604                                                                  ".gitmodules is a symbolic link");
 605                                 }
 606                                 backslash = strchr(backslash, '\\');
 607                         }
 608                 }
 609
 610                 if (update_tree_entry_gently(&desc)) {
 611                         retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
 612                         break;
 613                 }
 614
 615                 switch (mode) {
 616                 /*
 617                  * Standard modes..
 618                  */
 619                 case S_IFREG | 0755:
 620                 case S_IFREG | 0644:
 621                 case S_IFLNK:
 622                 case S_IFDIR:
 623                 case S_IFGITLINK:
 624                         break;
 625                 /*
 626                  * This is nonstandard, but we had a few of these
 627                  * early on when we honored the full set of mode
 628                  * bits..
 629                  */
 630                 case S_IFREG | 0664:
 631                         if (!options->strict)
 632                                 break;
 633                         /* fallthrough */
 634                 default:
 635                         has_bad_modes = 1;
 636                 }
 637
 638                 if (o_name) {
 639                         switch (verify_ordered(o_mode, o_name, mode, name)) {
 640                         case TREE_UNORDERED:
 641                                 not_properly_sorted = 1;
 642                                 break;
 643                         case TREE_HAS_DUPS:
 644                                 has_dup_entries = 1;
 645                                 break;
 646                         default:
 647                                 break;
 648                         }
 649                 }
 650
 651                 o_mode = mode;
 652                 o_name = name;
 653         }
 654
 655         if (has_null_sha1)
 656                 retval += report(options, &item->object, FSCK_MSG_NULL_SHA1, "contains entries pointing to null sha1");
 657         if (has_full_path)
 658                 retval += report(options, &item->object, FSCK_MSG_FULL_PATHNAME, "contains full pathnames");
 659         if (has_empty_name)
 660                 retval += report(options, &item->object, FSCK_MSG_EMPTY_NAME, "contains empty pathname");
 661         if (has_dot)
 662                 retval += report(options, &item->object, FSCK_MSG_HAS_DOT, "contains '.'");
 663         if (has_dotdot)
 664                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTDOT, "contains '..'");
 665         if (has_dotgit)
 666                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTGIT, "contains '.git'");
 667         if (has_zero_pad)
 668                 retval += report(options, &item->object, FSCK_MSG_ZERO_PADDED_FILEMODE, "contains zero-padded file modes");
 669         if (has_bad_modes)
 670                 retval += report(options, &item->object, FSCK_MSG_BAD_FILEMODE, "contains bad file modes");
 671         if (has_dup_entries)
 672                 retval += report(options, &item->object, FSCK_MSG_DUPLICATE_ENTRIES, "contains duplicate file entries");
 673         if (not_properly_sorted)
 674                 retval += report(options, &item->object, FSCK_MSG_TREE_NOT_SORTED, "not properly sorted");
 675         return retval;
 676 }
 677
 678 static int verify_headers(const void *data, unsigned long size,
 679                           struct object *obj, struct fsck_options *options)
 680 {
 681         const char *buffer = (const char *)data;
 682         unsigned long i;
 683
 684         for (i = 0; i < size; i++) {
 685                 switch (buffer[i]) {
 686                 case '\0':
 687                         return report(options, obj,
 688                                 FSCK_MSG_NUL_IN_HEADER,
 689                                 "unterminated header: NUL at offset %ld", i);
 690                 case '\n':
 691                         if (i + 1 < size && buffer[i + 1] == '\n')
 692                                 return 0;
 693                 }
 694         }
 695
 696         /*
 697          * We did not find double-LF that separates the header
 698          * and the body.  Not having a body is not a crime but
 699          * we do want to see the terminating LF for the last header
 700          * line.
 701          */
 702         if (size && buffer[size - 1] == '\n')
 703                 return 0;
 704
 705         return report(options, obj,
 706                 FSCK_MSG_UNTERMINATED_HEADER, "unterminated header");
 707 }
 708
 709 static int fsck_ident(const char **ident, struct object *obj, struct fsck_options *options)
 710 {
 711         const char *p = *ident;
 712         char *end;
 713
 714         *ident = strchrnul(*ident, '\n');
 715         if (**ident == '\n')
 716                 (*ident)++;
 717
 718         if (*p == '<')
 719                 return report(options, obj, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 720         p += strcspn(p, "<>\n");
 721         if (*p == '>')
 722                 return report(options, obj, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
 723         if (*p != '<')
 724                 return report(options, obj, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
 725         if (p[-1] != ' ')
 726                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 727         p++;
 728         p += strcspn(p, "<>\n");
 729         if (*p != '>')
 730                 return report(options, obj, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
 731         p++;
 732         if (*p != ' ')
 733                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
 734         p++;
 735         if (*p == '0' && p[1] != ' ')
 736                 return report(options, obj, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
 737         if (date_overflows(parse_timestamp(p, &end, 10)))
 738                 return report(options, obj, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
 739         if ((end == p || *end != ' '))
 740                 return report(options, obj, FSCK_MSG_BAD_DATE, "invalid author/committer line - bad date");
 741         p = end + 1;
 742         if ((*p != '+' && *p != '-') ||
 743             !isdigit(p[1]) ||
 744             !isdigit(p[2]) ||
 745             !isdigit(p[3]) ||
 746             !isdigit(p[4]) ||
 747             (p[5] != '\n'))
 748                 return report(options, obj, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
 749         p += 6;
 750         return 0;
 751 }
 752
 753 static int fsck_commit_buffer(struct commit *commit, const char *buffer,
 754         unsigned long size, struct fsck_options *options)
 755 {
 756         unsigned char tree_sha1[20], sha1[20];
 757         struct commit_graft *graft;
 758         unsigned parent_count, parent_line_count = 0, author_count;
 759         int err;
 760         const char *buffer_begin = buffer;
 761
 762         if (verify_headers(buffer, size, &commit->object, options))
 763                 return -1;
 764
 765         if (!skip_prefix(buffer, "tree ", &buffer))
 766                 return report(options, &commit->object, FSCK_MSG_MISSING_TREE, "invalid format - expected 'tree' line");
 767         if (get_sha1_hex(buffer, tree_sha1) || buffer[40] != '\n') {
 768                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE_SHA1, "invalid 'tree' line format - bad sha1");
 769                 if (err)
 770                         return err;
 771         }
 772         buffer += 41;
 773         while (skip_prefix(buffer, "parent ", &buffer)) {
 774                 if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n') {
 775                         err = report(options, &commit->object, FSCK_MSG_BAD_PARENT_SHA1, "invalid 'parent' line format - bad sha1");
 776                         if (err)
 777                                 return err;
 778                 }
 779                 buffer += 41;
 780                 parent_line_count++;
 781         }
 782         graft = lookup_commit_graft(&commit->object.oid);
 783         parent_count = commit_list_count(commit->parents);
 784         if (graft) {
 785                 if (graft->nr_parent == -1 && !parent_count)
 786                         ; /* shallow commit */
 787                 else if (graft->nr_parent != parent_count) {
 788                         err = report(options, &commit->object, FSCK_MSG_MISSING_GRAFT, "graft objects missing");
 789                         if (err)
 790                                 return err;
 791                 }
 792         } else {
 793                 if (parent_count != parent_line_count) {
 794                         err = report(options, &commit->object, FSCK_MSG_MISSING_PARENT, "parent objects missing");
 795                         if (err)
 796                                 return err;
 797                 }
 798         }
 799         author_count = 0;
 800         while (skip_prefix(buffer, "author ", &buffer)) {
 801                 author_count++;
 802                 err = fsck_ident(&buffer, &commit->object, options);
 803                 if (err)
 804                         return err;
 805         }
 806         if (author_count < 1)
 807                 err = report(options, &commit->object, FSCK_MSG_MISSING_AUTHOR, "invalid format - expected 'author' line");
 808         else if (author_count > 1)
 809                 err = report(options, &commit->object, FSCK_MSG_MULTIPLE_AUTHORS, "invalid format - multiple 'author' lines");
 810         if (err)
 811                 return err;
 812         if (!skip_prefix(buffer, "committer ", &buffer))
 813                 return report(options, &commit->object, FSCK_MSG_MISSING_COMMITTER, "invalid format - expected 'committer' line");
 814         err = fsck_ident(&buffer, &commit->object, options);
 815         if (err)
 816                 return err;
 817         if (!commit->tree) {
 818                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE, "could not load commit's tree %s", sha1_to_hex(tree_sha1));
 819                 if (err)
 820                         return err;
 821         }
 822         if (memchr(buffer_begin, '\0', size)) {
 823                 err = report(options, &commit->object, FSCK_MSG_NUL_IN_COMMIT,
 824                              "NUL byte in the commit object body");
 825                 if (err)
 826                         return err;
 827         }
 828         return 0;
 829 }
 830
 831 static int fsck_commit(struct commit *commit, const char *data,
 832         unsigned long size, struct fsck_options *options)
 833 {
 834         const char *buffer = data ?  data : get_commit_buffer(commit, &size);
 835         int ret = fsck_commit_buffer(commit, buffer, size, options);
 836         if (!data)
 837                 unuse_commit_buffer(commit, buffer);
 838         return ret;
 839 }
 840
 841 static int fsck_tag_buffer(struct tag *tag, const char *data,
 842         unsigned long size, struct fsck_options *options)
 843 {
 844         unsigned char sha1[20];
 845         int ret = 0;
 846         const char *buffer;
 847         char *to_free = NULL, *eol;
 848         struct strbuf sb = STRBUF_INIT;
 849
 850         if (data)
 851                 buffer = data;
 852         else {
 853                 enum object_type type;
 854
 855                 buffer = to_free =
 856                         read_sha1_file(tag->object.oid.hash, &type, &size);
 857                 if (!buffer)
 858                         return report(options, &tag->object,
 859                                 FSCK_MSG_MISSING_TAG_OBJECT,
 860                                 "cannot read tag object");
 861
 862                 if (type != OBJ_TAG) {
 863                         ret = report(options, &tag->object,
 864                                 FSCK_MSG_TAG_OBJECT_NOT_TAG,
 865                                 "expected tag got %s",
 866                             type_name(type));
 867                         goto done;
 868                 }
 869         }
 870
 871         ret = verify_headers(buffer, size, &tag->object, options);
 872         if (ret)
 873                 goto done;
 874
 875         if (!skip_prefix(buffer, "object ", &buffer)) {
 876                 ret = report(options, &tag->object, FSCK_MSG_MISSING_OBJECT, "invalid format - expected 'object' line");
 877                 goto done;
 878         }
 879         if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n') {
 880                 ret = report(options, &tag->object, FSCK_MSG_BAD_OBJECT_SHA1, "invalid 'object' line format - bad sha1");
 881                 if (ret)
 882                         goto done;
 883         }
 884         buffer += 41;
 885
 886         if (!skip_prefix(buffer, "type ", &buffer)) {
 887                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE_ENTRY, "invalid format - expected 'type' line");
 888                 goto done;
 889         }
 890         eol = strchr(buffer, '\n');
 891         if (!eol) {
 892                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE, "invalid format - unexpected end after 'type' line");
 893                 goto done;
 894         }
 895         if (type_from_string_gently(buffer, eol - buffer, 1) < 0)
 896                 ret = report(options, &tag->object, FSCK_MSG_BAD_TYPE, "invalid 'type' value");
 897         if (ret)
 898                 goto done;
 899         buffer = eol + 1;
 900
 901         if (!skip_prefix(buffer, "tag ", &buffer)) {
 902                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG_ENTRY, "invalid format - expected 'tag' line");
 903                 goto done;
 904         }
 905         eol = strchr(buffer, '\n');
 906         if (!eol) {
 907                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG, "invalid format - unexpected end after 'type' line");
 908                 goto done;
 909         }
 910         strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer);
 911         if (check_refname_format(sb.buf, 0)) {
 912                 ret = report(options, &tag->object, FSCK_MSG_BAD_TAG_NAME,
 913                            "invalid 'tag' name: %.*s",
 914                            (int)(eol - buffer), buffer);
 915                 if (ret)
 916                         goto done;
 917         }
 918         buffer = eol + 1;
 919
 920         if (!skip_prefix(buffer, "tagger ", &buffer)) {
 921                 /* early tags do not contain 'tagger' lines; warn only */
 922                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
 923                 if (ret)
 924                         goto done;
 925         }
 926         else
 927                 ret = fsck_ident(&buffer, &tag->object, options);
 928
 929 done:
 930         strbuf_release(&sb);
 931         free(to_free);
 932         return ret;
 933 }
 934
 935 static int fsck_tag(struct tag *tag, const char *data,
 936         unsigned long size, struct fsck_options *options)
 937 {
 938         struct object *tagged = tag->tagged;
 939
 940         if (!tagged)
 941                 return report(options, &tag->object, FSCK_MSG_BAD_TAG_OBJECT, "could not load tagged object");
 942
 943         return fsck_tag_buffer(tag, data, size, options);
 944 }
 945
 946 /*
 947  * Like builtin/submodule--helper.c's starts_with_dot_slash, but without
 948  * relying on the platform-dependent is_dir_sep helper.
 949  *
 950  * This is for use in checking whether a submodule URL is interpreted as
 951  * relative to the current directory on any platform, since \ is a
 952  * directory separator on Windows but not on other platforms.
 953  */
 954 static int starts_with_dot_slash(const char *str)
 955 {
 956         return str[0] == '.' && (str[1] == '/' || str[1] == '\\');
 957 }
 958
 959 /*
 960  * Like starts_with_dot_slash, this is a variant of submodule--helper's
 961  * helper of the same name with the twist that it accepts backslash as a
 962  * directory separator even on non-Windows platforms.
 963  */
 964 static int starts_with_dot_dot_slash(const char *str)
 965 {
 966         return str[0] == '.' && starts_with_dot_slash(str + 1);
 967 }
 968
 969 static int submodule_url_is_relative(const char *url)
 970 {
 971         return starts_with_dot_slash(url) || starts_with_dot_dot_slash(url);
 972 }
 973
 974 /*
 975  * Count directory components that a relative submodule URL should chop
 976  * from the remote_url it is to be resolved against.
 977  *
 978  * In other words, this counts "../" components at the start of a
 979  * submodule URL.
 980  *
 981  * Returns the number of directory components to chop and writes a
 982  * pointer to the next character of url after all leading "./" and
 983  * "../" components to out.
 984  */
 985 static int count_leading_dotdots(const char *url, const char **out)
 986 {
 987         int result = 0;
 988         while (1) {
 989                 if (starts_with_dot_dot_slash(url)) {
 990                         result++;
 991                         url += strlen("../");
 992                         continue;
 993                 }
 994                 if (starts_with_dot_slash(url)) {
 995                         url += strlen("./");
 996                         continue;
 997                 }
 998                 *out = url;
 999                 return result;
1000         }
1001 }
1002 /*
1003  * Check whether a transport is implemented by git-remote-curl.
1004  *
1005  * If it is, returns 1 and writes the URL that would be passed to
1006  * git-remote-curl to the "out" parameter.
1007  *
1008  * Otherwise, returns 0 and leaves "out" untouched.
1009  *
1010  * Examples:
1011  *   http::https://example.com/repo.git -> 1, https://example.com/repo.git
1012  *   https://example.com/repo.git -> 1, https://example.com/repo.git
1013  *   git://example.com/repo.git -> 0
1014  *
1015  * This is for use in checking for previously exploitable bugs that
1016  * required a submodule URL to be passed to git-remote-curl.
1017  */
1018 static int url_to_curl_url(const char *url, const char **out)
1019 {
1020         /*
1021          * We don't need to check for case-aliases, "http.exe", and so
1022          * on because in the default configuration, is_transport_allowed
1023          * prevents URLs with those schemes from being cloned
1024          * automatically.
1025          */
1026         if (skip_prefix(url, "http::", out) ||
1027             skip_prefix(url, "https::", out) ||
1028             skip_prefix(url, "ftp::", out) ||
1029             skip_prefix(url, "ftps::", out))
1030                 return 1;
1031         if (starts_with(url, "http://") ||
1032             starts_with(url, "https://") ||
1033             starts_with(url, "ftp://") ||
1034             starts_with(url, "ftps://")) {
1035                 *out = url;
1036                 return 1;
1037         }
1038         return 0;
1039 }
1040
1041 static int check_submodule_url(const char *url)
1042 {
1043         const char *curl_url;
1044
1045         if (looks_like_command_line_option(url))
1046                 return -1;
1047
1048         if (submodule_url_is_relative(url)) {
1049                 char *decoded;
1050                 const char *next;
1051                 int has_nl;
1052
1053                 /*
1054                  * This could be appended to an http URL and url-decoded;
1055                  * check for malicious characters.
1056                  */
1057                 decoded = url_decode(url);
1058                 has_nl = !!strchr(decoded, '\n');
1059
1060                 free(decoded);
1061                 if (has_nl)
1062                         return -1;
1063
1064                 /*
1065                  * URLs which escape their root via "../" can overwrite
1066                  * the host field and previous components, resolving to
1067                  * URLs like https::example.com/submodule.git and
1068                  * https:///example.com/submodule.git that were
1069                  * susceptible to CVE-2020-11008.
1070                  */
1071                 if (count_leading_dotdots(url, &next) > 0 &&
1072                     (*next == ':' || *next == '/'))
1073                         return -1;
1074         }
1075
1076         else if (url_to_curl_url(url, &curl_url)) {
1077                 struct credential c = CREDENTIAL_INIT;
1078                 int ret = 0;
1079                 if (credential_from_url_gently(&c, curl_url, 1) ||
1080                     !*c.host)
1081                         ret = -1;
1082                 credential_clear(&c);
1083                 return ret;
1084         }
1085
1086         return 0;
1087 }
1088
1089 struct fsck_gitmodules_data {
1090         struct object *obj;
1091         struct fsck_options *options;
1092         int ret;
1093 };
1094
1095 static int fsck_gitmodules_fn(const char *var, const char *value, void *vdata)
1096 {
1097         struct fsck_gitmodules_data *data = vdata;
1098         const char *subsection, *key;
1099         int subsection_len;
1100         char *name;
1101
1102         if (parse_config_key(var, "submodule", &subsection, &subsection_len, &key) < 0 ||
1103             !subsection)
1104                 return 0;
1105
1106         name = xmemdupz(subsection, subsection_len);
1107         if (check_submodule_name(name) < 0)
1108                 data->ret |= report(data->options, data->obj,
1109                                     FSCK_MSG_GITMODULES_NAME,
1110                                     "disallowed submodule name: %s",
1111                                     name);
1112         if (!strcmp(key, "url") && value &&
1113             check_submodule_url(value) < 0)
1114                 data->ret |= report(data->options, data->obj,
1115                                     FSCK_MSG_GITMODULES_URL,
1116                                     "disallowed submodule url: %s",
1117                                     value);
1118         if (!strcmp(key, "path") && value &&
1119             looks_like_command_line_option(value))
1120                 data->ret |= report(data->options, data->obj,
1121                                     FSCK_MSG_GITMODULES_PATH,
1122                                     "disallowed submodule path: %s",
1123                                     value);
1124         if (!strcmp(key, "update") && value &&
1125             parse_submodule_update_type(value) == SM_UPDATE_COMMAND)
1126                 data->ret |= report(data->options, data->obj,
1127                                     FSCK_MSG_GITMODULES_UPDATE,
1128                                     "disallowed submodule update setting: %s",
1129                                     value);
1130         free(name);
1131
1132         return 0;
1133 }
1134
1135 static int fsck_blob(struct blob *blob, const char *buf,
1136                      unsigned long size, struct fsck_options *options)
1137 {
1138         struct fsck_gitmodules_data data;
1139
1140         if (!oidset_contains(&gitmodules_found, &blob->object.oid))
1141                 return 0;
1142         oidset_insert(&gitmodules_done, &blob->object.oid);
1143
1144         if (!buf) {
1145                 /*
1146                  * A missing buffer here is a sign that the caller found the
1147                  * blob too gigantic to load into memory. Let's just consider
1148                  * that an error.
1149                  */
1150                 return report(options, &blob->object,
1151                               FSCK_MSG_GITMODULES_PARSE,
1152                               ".gitmodules too large to parse");
1153         }
1154
1155         data.obj = &blob->object;
1156         data.options = options;
1157         data.ret = 0;
1158         if (git_config_from_mem(fsck_gitmodules_fn, CONFIG_ORIGIN_BLOB,
1159                                 ".gitmodules", buf, size, &data))
1160                 data.ret |= report(options, &blob->object,
1161                                    FSCK_MSG_GITMODULES_PARSE,
1162                                    "could not parse gitmodules blob");
1163
1164         return data.ret;
1165 }
1166
1167 int fsck_object(struct object *obj, void *data, unsigned long size,
1168         struct fsck_options *options)
1169 {
1170         if (!obj)
1171                 return report(options, obj, FSCK_MSG_BAD_OBJECT_SHA1, "no valid object to fsck");
1172
1173         if (obj->type == OBJ_BLOB)
1174                 return fsck_blob((struct blob *)obj, data, size, options);
1175         if (obj->type == OBJ_TREE)
1176                 return fsck_tree((struct tree *) obj, options);
1177         if (obj->type == OBJ_COMMIT)
1178                 return fsck_commit((struct commit *) obj, (const char *) data,
1179                         size, options);
1180         if (obj->type == OBJ_TAG)
1181                 return fsck_tag((struct tag *) obj, (const char *) data,
1182                         size, options);
1183
1184         return report(options, obj, FSCK_MSG_UNKNOWN_TYPE, "unknown type '%d' (internal fsck error)",
1185                           obj->type);
1186 }
1187
1188 int fsck_error_function(struct fsck_options *o,
1189         struct object *obj, int msg_type, const char *message)
1190 {
1191         if (msg_type == FSCK_WARN) {
1192                 warning("object %s: %s", describe_object(o, obj), message);
1193                 return 0;
1194         }
1195         error("object %s: %s", describe_object(o, obj), message);
1196         return 1;
1197 }
1198
1199 int fsck_finish(struct fsck_options *options)
1200 {
1201         int ret = 0;
1202         struct oidset_iter iter;
1203         const struct object_id *oid;
1204
1205         oidset_iter_init(&gitmodules_found, &iter);
1206         while ((oid = oidset_iter_next(&iter))) {
1207                 struct blob *blob;
1208                 enum object_type type;
1209                 unsigned long size;
1210                 char *buf;
1211
1212                 if (oidset_contains(&gitmodules_done, oid))
1213                         continue;
1214
1215                 blob = lookup_blob(oid);
1216                 if (!blob) {
1217                         ret |= report(options, &blob->object,
1218                                       FSCK_MSG_GITMODULES_BLOB,
1219                                       "non-blob found at .gitmodules");
1220                         continue;
1221                 }
1222
1223                 buf = read_sha1_file(oid->hash, &type, &size);
1224                 if (!buf) {
1225                         if (is_promisor_object(&blob->object.oid))
1226                                 continue;
1227                         ret |= report(options, &blob->object,
1228                                       FSCK_MSG_GITMODULES_MISSING,
1229                                       "unable to read .gitmodules blob");
1230                         continue;
1231                 }
1232
1233                 if (type == OBJ_BLOB)
1234                         ret |= fsck_blob(blob, buf, size, options);
1235                 else
1236                         ret |= report(options, &blob->object,
1237                                       FSCK_MSG_GITMODULES_BLOB,
1238                                       "non-blob found at .gitmodules");
1239                 free(buf);
1240         }
1241
1242
1243         oidset_clear(&gitmodules_found);
1244         oidset_clear(&gitmodules_done);
1245         return ret;
1246 }