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_NAME_BEFORE_EMAIL, ERROR) \
  49         FUNC(MISSING_OBJECT, 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_TREE, ERROR) \
  55         FUNC(MISSING_TREE_OBJECT, ERROR) \
  56         FUNC(MISSING_TYPE, ERROR) \
  57         FUNC(MISSING_TYPE_ENTRY, ERROR) \
  58         FUNC(MULTIPLE_AUTHORS, ERROR) \
  59         FUNC(TREE_NOT_SORTED, ERROR) \
  60         FUNC(UNKNOWN_TYPE, ERROR) \
  61         FUNC(ZERO_PADDED_DATE, ERROR) \
  62         FUNC(GITMODULES_MISSING, ERROR) \
  63         FUNC(GITMODULES_BLOB, ERROR) \
  64         FUNC(GITMODULES_LARGE, ERROR) \
  65         FUNC(GITMODULES_NAME, ERROR) \
  66         FUNC(GITMODULES_SYMLINK, ERROR) \
  67         FUNC(GITMODULES_URL, ERROR) \
  68         FUNC(GITMODULES_PATH, ERROR) \
  69         FUNC(GITMODULES_UPDATE, ERROR) \
  70         /* warnings */ \
  71         FUNC(BAD_FILEMODE, WARN) \
  72         FUNC(EMPTY_NAME, WARN) \
  73         FUNC(FULL_PATHNAME, WARN) \
  74         FUNC(HAS_DOT, WARN) \
  75         FUNC(HAS_DOTDOT, WARN) \
  76         FUNC(HAS_DOTGIT, WARN) \
  77         FUNC(NULL_SHA1, WARN) \
  78         FUNC(ZERO_PADDED_FILEMODE, WARN) \
  79         FUNC(NUL_IN_COMMIT, WARN) \
  80         /* infos (reported as warnings, but ignored by default) */ \
  81         FUNC(GITMODULES_PARSE, INFO) \
  82         FUNC(BAD_TAG_NAME, INFO) \
  83         FUNC(MISSING_TAGGER_ENTRY, INFO)
  84
  85 #define MSG_ID(id, msg_type) FSCK_MSG_##id,
  86 enum fsck_msg_id {
  87         FOREACH_MSG_ID(MSG_ID)
  88         FSCK_MSG_MAX
  89 };
  90 #undef MSG_ID
  91
  92 #define STR(x) #x
  93 #define MSG_ID(id, msg_type) { STR(id), NULL, NULL, FSCK_##msg_type },
  94 static struct {
  95         const char *id_string;
  96         const char *downcased;
  97         const char *camelcased;
  98         int msg_type;
  99 } msg_id_info[FSCK_MSG_MAX + 1] = {
 100         FOREACH_MSG_ID(MSG_ID)
 101         { NULL, NULL, NULL, -1 }
 102 };
 103 #undef MSG_ID
 104
 105 static void prepare_msg_ids(void)
 106 {
 107         int i;
 108
 109         if (msg_id_info[0].downcased)
 110                 return;
 111
 112         /* convert id_string to lower case, without underscores. */
 113         for (i = 0; i < FSCK_MSG_MAX; i++) {
 114                 const char *p = msg_id_info[i].id_string;
 115                 int len = strlen(p);
 116                 char *q = xmalloc(len);
 117
 118                 msg_id_info[i].downcased = q;
 119                 while (*p)
 120                         if (*p == '_')
 121                                 p++;
 122                         else
 123                                 *(q)++ = tolower(*(p)++);
 124                 *q = '\0';
 125
 126                 p = msg_id_info[i].id_string;
 127                 q = xmalloc(len);
 128                 msg_id_info[i].camelcased = q;
 129                 while (*p) {
 130                         if (*p == '_') {
 131                                 p++;
 132                                 if (*p)
 133                                         *q++ = *p++;
 134                         } else {
 135                                 *q++ = tolower(*p++);
 136                         }
 137                 }
 138                 *q = '\0';
 139         }
 140 }
 141
 142 static int parse_msg_id(const char *text)
 143 {
 144         int i;
 145
 146         prepare_msg_ids();
 147
 148         for (i = 0; i < FSCK_MSG_MAX; i++)
 149                 if (!strcmp(text, msg_id_info[i].downcased))
 150                         return i;
 151
 152         return -1;
 153 }
 154
 155 void list_config_fsck_msg_ids(struct string_list *list, const char *prefix)
 156 {
 157         int i;
 158
 159         prepare_msg_ids();
 160
 161         for (i = 0; i < FSCK_MSG_MAX; i++)
 162                 list_config_item(list, prefix, msg_id_info[i].camelcased);
 163 }
 164
 165 static int fsck_msg_type(enum fsck_msg_id msg_id,
 166         struct fsck_options *options)
 167 {
 168         int msg_type;
 169
 170         assert(msg_id >= 0 && msg_id < FSCK_MSG_MAX);
 171
 172         if (options->msg_type)
 173                 msg_type = options->msg_type[msg_id];
 174         else {
 175                 msg_type = msg_id_info[msg_id].msg_type;
 176                 if (options->strict && msg_type == FSCK_WARN)
 177                         msg_type = FSCK_ERROR;
 178         }
 179
 180         return msg_type;
 181 }
 182
 183 static int parse_msg_type(const char *str)
 184 {
 185         if (!strcmp(str, "error"))
 186                 return FSCK_ERROR;
 187         else if (!strcmp(str, "warn"))
 188                 return FSCK_WARN;
 189         else if (!strcmp(str, "ignore"))
 190                 return FSCK_IGNORE;
 191         else
 192                 die("Unknown fsck message type: '%s'", str);
 193 }
 194
 195 int is_valid_msg_type(const char *msg_id, const char *msg_type)
 196 {
 197         if (parse_msg_id(msg_id) < 0)
 198                 return 0;
 199         parse_msg_type(msg_type);
 200         return 1;
 201 }
 202
 203 void fsck_set_msg_type(struct fsck_options *options,
 204                 const char *msg_id, const char *msg_type)
 205 {
 206         int id = parse_msg_id(msg_id), type;
 207
 208         if (id < 0)
 209                 die("Unhandled message id: %s", msg_id);
 210         type = parse_msg_type(msg_type);
 211
 212         if (type != FSCK_ERROR && msg_id_info[id].msg_type == FSCK_FATAL)
 213                 die("Cannot demote %s to %s", msg_id, msg_type);
 214
 215         if (!options->msg_type) {
 216                 int i;
 217                 int *msg_type;
 218                 ALLOC_ARRAY(msg_type, FSCK_MSG_MAX);
 219                 for (i = 0; i < FSCK_MSG_MAX; i++)
 220                         msg_type[i] = fsck_msg_type(i, options);
 221                 options->msg_type = msg_type;
 222         }
 223
 224         options->msg_type[id] = type;
 225 }
 226
 227 void fsck_set_msg_types(struct fsck_options *options, const char *values)
 228 {
 229         char *buf = xstrdup(values), *to_free = buf;
 230         int done = 0;
 231
 232         while (!done) {
 233                 int len = strcspn(buf, " ,|"), equal;
 234
 235                 done = !buf[len];
 236                 if (!len) {
 237                         buf++;
 238                         continue;
 239                 }
 240                 buf[len] = '\0';
 241
 242                 for (equal = 0;
 243                      equal < len && buf[equal] != '=' && buf[equal] != ':';
 244                      equal++)
 245                         buf[equal] = tolower(buf[equal]);
 246                 buf[equal] = '\0';
 247
 248                 if (!strcmp(buf, "skiplist")) {
 249                         if (equal == len)
 250                                 die("skiplist requires a path");
 251                         oidset_parse_file(&options->skiplist, buf + equal + 1);
 252                         buf += len + 1;
 253                         continue;
 254                 }
 255
 256                 if (equal == len)
 257                         die("Missing '=': '%s'", buf);
 258
 259                 fsck_set_msg_type(options, buf, buf + equal + 1);
 260                 buf += len + 1;
 261         }
 262         free(to_free);
 263 }
 264
 265 static void append_msg_id(struct strbuf *sb, const char *msg_id)
 266 {
 267         for (;;) {
 268                 char c = *(msg_id)++;
 269
 270                 if (!c)
 271                         break;
 272                 if (c != '_')
 273                         strbuf_addch(sb, tolower(c));
 274                 else {
 275                         assert(*msg_id);
 276                         strbuf_addch(sb, *(msg_id)++);
 277                 }
 278         }
 279
 280         strbuf_addstr(sb, ": ");
 281 }
 282
 283 static int object_on_skiplist(struct fsck_options *opts,
 284                               const struct object_id *oid)
 285 {
 286         return opts && oid && oidset_contains(&opts->skiplist, oid);
 287 }
 288
 289 __attribute__((format (printf, 5, 6)))
 290 static int report(struct fsck_options *options,
 291                   const struct object_id *oid, enum object_type object_type,
 292                   enum fsck_msg_id id, const char *fmt, ...)
 293 {
 294         va_list ap;
 295         struct strbuf sb = STRBUF_INIT;
 296         int msg_type = fsck_msg_type(id, options), result;
 297
 298         if (msg_type == FSCK_IGNORE)
 299                 return 0;
 300
 301         if (object_on_skiplist(options, oid))
 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, oid, object_type,
 314                                      msg_type, sb.buf);
 315         strbuf_release(&sb);
 316         va_end(ap);
 317
 318         return result;
 319 }
 320
 321 void fsck_enable_object_names(struct fsck_options *options)
 322 {
 323         if (!options->object_names)
 324                 options->object_names = kh_init_oid_map();
 325 }
 326
 327 const char *fsck_get_object_name(struct fsck_options *options,
 328                                  const struct object_id *oid)
 329 {
 330         khiter_t pos;
 331         if (!options->object_names)
 332                 return NULL;
 333         pos = kh_get_oid_map(options->object_names, *oid);
 334         if (pos >= kh_end(options->object_names))
 335                 return NULL;
 336         return kh_value(options->object_names, pos);
 337 }
 338
 339 void fsck_put_object_name(struct fsck_options *options,
 340                           const struct object_id *oid,
 341                           const char *fmt, ...)
 342 {
 343         va_list ap;
 344         struct strbuf buf = STRBUF_INIT;
 345         khiter_t pos;
 346         int hashret;
 347
 348         if (!options->object_names)
 349                 return;
 350
 351         pos = kh_put_oid_map(options->object_names, *oid, &hashret);
 352         if (!hashret)
 353                 return;
 354         va_start(ap, fmt);
 355         strbuf_vaddf(&buf, fmt, ap);
 356         kh_value(options->object_names, pos) = strbuf_detach(&buf, NULL);
 357         va_end(ap);
 358 }
 359
 360 const char *fsck_describe_object(struct fsck_options *options,
 361                                  const struct object_id *oid)
 362 {
 363         static struct strbuf bufs[] = {
 364                 STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
 365         };
 366         static int b = 0;
 367         struct strbuf *buf;
 368         const char *name = fsck_get_object_name(options, oid);
 369
 370         buf = bufs + b;
 371         b = (b + 1) % ARRAY_SIZE(bufs);
 372         strbuf_reset(buf);
 373         strbuf_addstr(buf, oid_to_hex(oid));
 374         if (name)
 375                 strbuf_addf(buf, " (%s)", name);
 376
 377         return buf->buf;
 378 }
 379
 380 static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *options)
 381 {
 382         struct tree_desc desc;
 383         struct name_entry entry;
 384         int res = 0;
 385         const char *name;
 386
 387         if (parse_tree(tree))
 388                 return -1;
 389
 390         name = fsck_get_object_name(options, &tree->object.oid);
 391         if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
 392                 return -1;
 393         while (tree_entry_gently(&desc, &entry)) {
 394                 struct object *obj;
 395                 int result;
 396
 397                 if (S_ISGITLINK(entry.mode))
 398                         continue;
 399
 400                 if (S_ISDIR(entry.mode)) {
 401                         obj = (struct object *)lookup_tree(the_repository, &entry.oid);
 402                         if (name && obj)
 403                                 fsck_put_object_name(options, &entry.oid, "%s%s/",
 404                                                      name, entry.path);
 405                         result = options->walk(obj, OBJ_TREE, data, options);
 406                 }
 407                 else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode)) {
 408                         obj = (struct object *)lookup_blob(the_repository, &entry.oid);
 409                         if (name && obj)
 410                                 fsck_put_object_name(options, &entry.oid, "%s%s",
 411                                                      name, entry.path);
 412                         result = options->walk(obj, OBJ_BLOB, data, options);
 413                 }
 414                 else {
 415                         result = error("in tree %s: entry %s has bad mode %.6o",
 416                                        fsck_describe_object(options, &tree->object.oid),
 417                                        entry.path, entry.mode);
 418                 }
 419                 if (result < 0)
 420                         return result;
 421                 if (!res)
 422                         res = result;
 423         }
 424         return res;
 425 }
 426
 427 static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_options *options)
 428 {
 429         int counter = 0, generation = 0, name_prefix_len = 0;
 430         struct commit_list *parents;
 431         int res;
 432         int result;
 433         const char *name;
 434
 435         if (parse_commit(commit))
 436                 return -1;
 437
 438         name = fsck_get_object_name(options, &commit->object.oid);
 439         if (name)
 440                 fsck_put_object_name(options, get_commit_tree_oid(commit),
 441                                      "%s:", name);
 442
 443         result = options->walk((struct object *)get_commit_tree(commit),
 444                                OBJ_TREE, data, options);
 445         if (result < 0)
 446                 return result;
 447         res = result;
 448
 449         parents = commit->parents;
 450         if (name && parents) {
 451                 int len = strlen(name), power;
 452
 453                 if (len && name[len - 1] == '^') {
 454                         generation = 1;
 455                         name_prefix_len = len - 1;
 456                 }
 457                 else { /* parse ~<generation> suffix */
 458                         for (generation = 0, power = 1;
 459                              len && isdigit(name[len - 1]);
 460                              power *= 10)
 461                                 generation += power * (name[--len] - '0');
 462                         if (power > 1 && len && name[len - 1] == '~')
 463                                 name_prefix_len = len - 1;
 464                 }
 465         }
 466
 467         while (parents) {
 468                 if (name) {
 469                         struct object_id *oid = &parents->item->object.oid;
 470
 471                         if (counter++)
 472                                 fsck_put_object_name(options, oid, "%s^%d",
 473                                                      name, counter);
 474                         else if (generation > 0)
 475                                 fsck_put_object_name(options, oid, "%.*s~%d",
 476                                                      name_prefix_len, name,
 477                                                      generation + 1);
 478                         else
 479                                 fsck_put_object_name(options, oid, "%s^", name);
 480                 }
 481                 result = options->walk((struct object *)parents->item, OBJ_COMMIT, data, options);
 482                 if (result < 0)
 483                         return result;
 484                 if (!res)
 485                         res = result;
 486                 parents = parents->next;
 487         }
 488         return res;
 489 }
 490
 491 static int fsck_walk_tag(struct tag *tag, void *data, struct fsck_options *options)
 492 {
 493         const char *name = fsck_get_object_name(options, &tag->object.oid);
 494
 495         if (parse_tag(tag))
 496                 return -1;
 497         if (name)
 498                 fsck_put_object_name(options, &tag->tagged->oid, "%s", name);
 499         return options->walk(tag->tagged, OBJ_ANY, data, options);
 500 }
 501
 502 int fsck_walk(struct object *obj, void *data, struct fsck_options *options)
 503 {
 504         if (!obj)
 505                 return -1;
 506
 507         if (obj->type == OBJ_NONE)
 508                 parse_object(the_repository, &obj->oid);
 509
 510         switch (obj->type) {
 511         case OBJ_BLOB:
 512                 return 0;
 513         case OBJ_TREE:
 514                 return fsck_walk_tree((struct tree *)obj, data, options);
 515         case OBJ_COMMIT:
 516                 return fsck_walk_commit((struct commit *)obj, data, options);
 517         case OBJ_TAG:
 518                 return fsck_walk_tag((struct tag *)obj, data, options);
 519         default:
 520                 error("Unknown object type for %s",
 521                       fsck_describe_object(options, &obj->oid));
 522                 return -1;
 523         }
 524 }
 525
 526 struct name_stack {
 527         const char **names;
 528         size_t nr, alloc;
 529 };
 530
 531 static void name_stack_push(struct name_stack *stack, const char *name)
 532 {
 533         ALLOC_GROW(stack->names, stack->nr + 1, stack->alloc);
 534         stack->names[stack->nr++] = name;
 535 }
 536
 537 static const char *name_stack_pop(struct name_stack *stack)
 538 {
 539         return stack->nr ? stack->names[--stack->nr] : NULL;
 540 }
 541
 542 static void name_stack_clear(struct name_stack *stack)
 543 {
 544         FREE_AND_NULL(stack->names);
 545         stack->nr = stack->alloc = 0;
 546 }
 547
 548 /*
 549  * The entries in a tree are ordered in the _path_ order,
 550  * which means that a directory entry is ordered by adding
 551  * a slash to the end of it.
 552  *
 553  * So a directory called "a" is ordered _after_ a file
 554  * called "a.c", because "a/" sorts after "a.c".
 555  */
 556 #define TREE_UNORDERED (-1)
 557 #define TREE_HAS_DUPS  (-2)
 558
 559 static int is_less_than_slash(unsigned char c)
 560 {
 561         return '\0' < c && c < '/';
 562 }
 563
 564 static int verify_ordered(unsigned mode1, const char *name1,
 565                           unsigned mode2, const char *name2,
 566                           struct name_stack *candidates)
 567 {
 568         int len1 = strlen(name1);
 569         int len2 = strlen(name2);
 570         int len = len1 < len2 ? len1 : len2;
 571         unsigned char c1, c2;
 572         int cmp;
 573
 574         cmp = memcmp(name1, name2, len);
 575         if (cmp < 0)
 576                 return 0;
 577         if (cmp > 0)
 578                 return TREE_UNORDERED;
 579
 580         /*
 581          * Ok, the first <len> characters are the same.
 582          * Now we need to order the next one, but turn
 583          * a '\0' into a '/' for a directory entry.
 584          */
 585         c1 = name1[len];
 586         c2 = name2[len];
 587         if (!c1 && !c2)
 588                 /*
 589                  * git-write-tree used to write out a nonsense tree that has
 590                  * entries with the same name, one blob and one tree.  Make
 591                  * sure we do not have duplicate entries.
 592                  */
 593                 return TREE_HAS_DUPS;
 594         if (!c1 && S_ISDIR(mode1))
 595                 c1 = '/';
 596         if (!c2 && S_ISDIR(mode2))
 597                 c2 = '/';
 598
 599         /*
 600          * There can be non-consecutive duplicates due to the implicitly
 601          * add slash, e.g.:
 602          *
 603          *   foo
 604          *   foo.bar
 605          *   foo.bar.baz
 606          *   foo.bar/
 607          *   foo/
 608          *
 609          * Record non-directory candidates (like "foo" and "foo.bar" in
 610          * the example) on a stack and check directory candidates (like
 611          * foo/" and "foo.bar/") against that stack.
 612          */
 613         if (!c1 && is_less_than_slash(c2)) {
 614                 name_stack_push(candidates, name1);
 615         } else if (c2 == '/' && is_less_than_slash(c1)) {
 616                 for (;;) {
 617                         const char *p;
 618                         const char *f_name = name_stack_pop(candidates);
 619
 620                         if (!f_name)
 621                                 break;
 622                         if (!skip_prefix(name2, f_name, &p))
 623                                 break;
 624                         if (!*p)
 625                                 return TREE_HAS_DUPS;
 626                         if (is_less_than_slash(*p)) {
 627                                 name_stack_push(candidates, f_name);
 628                                 break;
 629                         }
 630                 }
 631         }
 632
 633         return c1 < c2 ? 0 : TREE_UNORDERED;
 634 }
 635
 636 static int fsck_tree(const struct object_id *oid,
 637                      const char *buffer, unsigned long size,
 638                      struct fsck_options *options)
 639 {
 640         int retval = 0;
 641         int has_null_sha1 = 0;
 642         int has_full_path = 0;
 643         int has_empty_name = 0;
 644         int has_dot = 0;
 645         int has_dotdot = 0;
 646         int has_dotgit = 0;
 647         int has_zero_pad = 0;
 648         int has_bad_modes = 0;
 649         int has_dup_entries = 0;
 650         int not_properly_sorted = 0;
 651         struct tree_desc desc;
 652         unsigned o_mode;
 653         const char *o_name;
 654         struct name_stack df_dup_candidates = { NULL };
 655
 656         if (init_tree_desc_gently(&desc, buffer, size)) {
 657                 retval += report(options, oid, OBJ_TREE, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
 658                 return retval;
 659         }
 660
 661         o_mode = 0;
 662         o_name = NULL;
 663
 664         while (desc.size) {
 665                 unsigned short mode;
 666                 const char *name, *backslash;
 667                 const struct object_id *oid;
 668
 669                 oid = tree_entry_extract(&desc, &name, &mode);
 670
 671                 has_null_sha1 |= is_null_oid(oid);
 672                 has_full_path |= !!strchr(name, '/');
 673                 has_empty_name |= !*name;
 674                 has_dot |= !strcmp(name, ".");
 675                 has_dotdot |= !strcmp(name, "..");
 676                 has_dotgit |= is_hfs_dotgit(name) || is_ntfs_dotgit(name);
 677                 has_zero_pad |= *(char *)desc.buffer == '0';
 678
 679                 if (is_hfs_dotgitmodules(name) || is_ntfs_dotgitmodules(name)) {
 680                         if (!S_ISLNK(mode))
 681                                 oidset_insert(&gitmodules_found, oid);
 682                         else
 683                                 retval += report(options,
 684                                                  oid, OBJ_TREE,
 685                                                  FSCK_MSG_GITMODULES_SYMLINK,
 686                                                  ".gitmodules is a symbolic link");
 687                 }
 688
 689                 if ((backslash = strchr(name, '\\'))) {
 690                         while (backslash) {
 691                                 backslash++;
 692                                 has_dotgit |= is_ntfs_dotgit(backslash);
 693                                 if (is_ntfs_dotgitmodules(backslash)) {
 694                                         if (!S_ISLNK(mode))
 695                                                 oidset_insert(&gitmodules_found, oid);
 696                                         else
 697                                                 retval += report(options, oid, OBJ_TREE,
 698                                                                  FSCK_MSG_GITMODULES_SYMLINK,
 699                                                                  ".gitmodules is a symbolic link");
 700                                 }
 701                                 backslash = strchr(backslash, '\\');
 702                         }
 703                 }
 704
 705                 if (update_tree_entry_gently(&desc)) {
 706                         retval += report(options, oid, OBJ_TREE, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
 707                         break;
 708                 }
 709
 710                 switch (mode) {
 711                 /*
 712                  * Standard modes..
 713                  */
 714                 case S_IFREG | 0755:
 715                 case S_IFREG | 0644:
 716                 case S_IFLNK:
 717                 case S_IFDIR:
 718                 case S_IFGITLINK:
 719                         break;
 720                 /*
 721                  * This is nonstandard, but we had a few of these
 722                  * early on when we honored the full set of mode
 723                  * bits..
 724                  */
 725                 case S_IFREG | 0664:
 726                         if (!options->strict)
 727                                 break;
 728                         /* fallthrough */
 729                 default:
 730                         has_bad_modes = 1;
 731                 }
 732
 733                 if (o_name) {
 734                         switch (verify_ordered(o_mode, o_name, mode, name,
 735                                                &df_dup_candidates)) {
 736                         case TREE_UNORDERED:
 737                                 not_properly_sorted = 1;
 738                                 break;
 739                         case TREE_HAS_DUPS:
 740                                 has_dup_entries = 1;
 741                                 break;
 742                         default:
 743                                 break;
 744                         }
 745                 }
 746
 747                 o_mode = mode;
 748                 o_name = name;
 749         }
 750
 751         name_stack_clear(&df_dup_candidates);
 752
 753         if (has_null_sha1)
 754                 retval += report(options, oid, OBJ_TREE, FSCK_MSG_NULL_SHA1, "contains entries pointing to null sha1");
 755         if (has_full_path)
 756                 retval += report(options, oid, OBJ_TREE, FSCK_MSG_FULL_PATHNAME, "contains full pathnames");
 757         if (has_empty_name)
 758                 retval += report(options, oid, OBJ_TREE, FSCK_MSG_EMPTY_NAME, "contains empty pathname");
 759         if (has_dot)
 760                 retval += report(options, oid, OBJ_TREE, FSCK_MSG_HAS_DOT, "contains '.'");
 761         if (has_dotdot)
 762                 retval += report(options, oid, OBJ_TREE, FSCK_MSG_HAS_DOTDOT, "contains '..'");
 763         if (has_dotgit)
 764                 retval += report(options, oid, OBJ_TREE, FSCK_MSG_HAS_DOTGIT, "contains '.git'");
 765         if (has_zero_pad)
 766                 retval += report(options, oid, OBJ_TREE, FSCK_MSG_ZERO_PADDED_FILEMODE, "contains zero-padded file modes");
 767         if (has_bad_modes)
 768                 retval += report(options, oid, OBJ_TREE, FSCK_MSG_BAD_FILEMODE, "contains bad file modes");
 769         if (has_dup_entries)
 770                 retval += report(options, oid, OBJ_TREE, FSCK_MSG_DUPLICATE_ENTRIES, "contains duplicate file entries");
 771         if (not_properly_sorted)
 772                 retval += report(options, oid, OBJ_TREE, FSCK_MSG_TREE_NOT_SORTED, "not properly sorted");
 773         return retval;
 774 }
 775
 776 static int verify_headers(const void *data, unsigned long size,
 777                           const struct object_id *oid, enum object_type type,
 778                           struct fsck_options *options)
 779 {
 780         const char *buffer = (const char *)data;
 781         unsigned long i;
 782
 783         for (i = 0; i < size; i++) {
 784                 switch (buffer[i]) {
 785                 case '\0':
 786                         return report(options, oid, type,
 787                                 FSCK_MSG_NUL_IN_HEADER,
 788                                 "unterminated header: NUL at offset %ld", i);
 789                 case '\n':
 790                         if (i + 1 < size && buffer[i + 1] == '\n')
 791                                 return 0;
 792                 }
 793         }
 794
 795         /*
 796          * We did not find double-LF that separates the header
 797          * and the body.  Not having a body is not a crime but
 798          * we do want to see the terminating LF for the last header
 799          * line.
 800          */
 801         if (size && buffer[size - 1] == '\n')
 802                 return 0;
 803
 804         return report(options, oid, type,
 805                 FSCK_MSG_UNTERMINATED_HEADER, "unterminated header");
 806 }
 807
 808 static int fsck_ident(const char **ident,
 809                       const struct object_id *oid, enum object_type type,
 810                       struct fsck_options *options)
 811 {
 812         const char *p = *ident;
 813         char *end;
 814
 815         *ident = strchrnul(*ident, '\n');
 816         if (**ident == '\n')
 817                 (*ident)++;
 818
 819         if (*p == '<')
 820                 return report(options, oid, type, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 821         p += strcspn(p, "<>\n");
 822         if (*p == '>')
 823                 return report(options, oid, type, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
 824         if (*p != '<')
 825                 return report(options, oid, type, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
 826         if (p[-1] != ' ')
 827                 return report(options, oid, type, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 828         p++;
 829         p += strcspn(p, "<>\n");
 830         if (*p != '>')
 831                 return report(options, oid, type, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
 832         p++;
 833         if (*p != ' ')
 834                 return report(options, oid, type, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
 835         p++;
 836         if (*p == '0' && p[1] != ' ')
 837                 return report(options, oid, type, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
 838         if (date_overflows(parse_timestamp(p, &end, 10)))
 839                 return report(options, oid, type, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
 840         if ((end == p || *end != ' '))
 841                 return report(options, oid, type, FSCK_MSG_BAD_DATE, "invalid author/committer line - bad date");
 842         p = end + 1;
 843         if ((*p != '+' && *p != '-') ||
 844             !isdigit(p[1]) ||
 845             !isdigit(p[2]) ||
 846             !isdigit(p[3]) ||
 847             !isdigit(p[4]) ||
 848             (p[5] != '\n'))
 849                 return report(options, oid, type, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
 850         p += 6;
 851         return 0;
 852 }
 853
 854 static int fsck_commit(const struct object_id *oid,
 855                        const char *buffer, unsigned long size,
 856                        struct fsck_options *options)
 857 {
 858         struct object_id tree_oid, parent_oid;
 859         unsigned author_count;
 860         int err;
 861         const char *buffer_begin = buffer;
 862         const char *p;
 863
 864         if (verify_headers(buffer, size, oid, OBJ_COMMIT, options))
 865                 return -1;
 866
 867         if (!skip_prefix(buffer, "tree ", &buffer))
 868                 return report(options, oid, OBJ_COMMIT, FSCK_MSG_MISSING_TREE, "invalid format - expected 'tree' line");
 869         if (parse_oid_hex(buffer, &tree_oid, &p) || *p != '\n') {
 870                 err = report(options, oid, OBJ_COMMIT, FSCK_MSG_BAD_TREE_SHA1, "invalid 'tree' line format - bad sha1");
 871                 if (err)
 872                         return err;
 873         }
 874         buffer = p + 1;
 875         while (skip_prefix(buffer, "parent ", &buffer)) {
 876                 if (parse_oid_hex(buffer, &parent_oid, &p) || *p != '\n') {
 877                         err = report(options, oid, OBJ_COMMIT, FSCK_MSG_BAD_PARENT_SHA1, "invalid 'parent' line format - bad sha1");
 878                         if (err)
 879                                 return err;
 880                 }
 881                 buffer = p + 1;
 882         }
 883         author_count = 0;
 884         while (skip_prefix(buffer, "author ", &buffer)) {
 885                 author_count++;
 886                 err = fsck_ident(&buffer, oid, OBJ_COMMIT, options);
 887                 if (err)
 888                         return err;
 889         }
 890         if (author_count < 1)
 891                 err = report(options, oid, OBJ_COMMIT, FSCK_MSG_MISSING_AUTHOR, "invalid format - expected 'author' line");
 892         else if (author_count > 1)
 893                 err = report(options, oid, OBJ_COMMIT, FSCK_MSG_MULTIPLE_AUTHORS, "invalid format - multiple 'author' lines");
 894         if (err)
 895                 return err;
 896         if (!skip_prefix(buffer, "committer ", &buffer))
 897                 return report(options, oid, OBJ_COMMIT, FSCK_MSG_MISSING_COMMITTER, "invalid format - expected 'committer' line");
 898         err = fsck_ident(&buffer, oid, OBJ_COMMIT, options);
 899         if (err)
 900                 return err;
 901         if (memchr(buffer_begin, '\0', size)) {
 902                 err = report(options, oid, OBJ_COMMIT, FSCK_MSG_NUL_IN_COMMIT,
 903                              "NUL byte in the commit object body");
 904                 if (err)
 905                         return err;
 906         }
 907         return 0;
 908 }
 909
 910 static int fsck_tag(const struct object_id *oid, const char *buffer,
 911                     unsigned long size, struct fsck_options *options)
 912 {
 913         struct object_id tagged_oid;
 914         int ret = 0;
 915         char *eol;
 916         struct strbuf sb = STRBUF_INIT;
 917         const char *p;
 918
 919         ret = verify_headers(buffer, size, oid, OBJ_TAG, options);
 920         if (ret)
 921                 goto done;
 922
 923         if (!skip_prefix(buffer, "object ", &buffer)) {
 924                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_OBJECT, "invalid format - expected 'object' line");
 925                 goto done;
 926         }
 927         if (parse_oid_hex(buffer, &tagged_oid, &p) || *p != '\n') {
 928                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_BAD_OBJECT_SHA1, "invalid 'object' line format - bad sha1");
 929                 if (ret)
 930                         goto done;
 931         }
 932         buffer = p + 1;
 933
 934         if (!skip_prefix(buffer, "type ", &buffer)) {
 935                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_TYPE_ENTRY, "invalid format - expected 'type' line");
 936                 goto done;
 937         }
 938         eol = strchr(buffer, '\n');
 939         if (!eol) {
 940                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_TYPE, "invalid format - unexpected end after 'type' line");
 941                 goto done;
 942         }
 943         if (type_from_string_gently(buffer, eol - buffer, 1) < 0)
 944                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_BAD_TYPE, "invalid 'type' value");
 945         if (ret)
 946                 goto done;
 947         buffer = eol + 1;
 948
 949         if (!skip_prefix(buffer, "tag ", &buffer)) {
 950                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_TAG_ENTRY, "invalid format - expected 'tag' line");
 951                 goto done;
 952         }
 953         eol = strchr(buffer, '\n');
 954         if (!eol) {
 955                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_TAG, "invalid format - unexpected end after 'type' line");
 956                 goto done;
 957         }
 958         strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer);
 959         if (check_refname_format(sb.buf, 0)) {
 960                 ret = report(options, oid, OBJ_TAG,
 961                              FSCK_MSG_BAD_TAG_NAME,
 962                              "invalid 'tag' name: %.*s",
 963                              (int)(eol - buffer), buffer);
 964                 if (ret)
 965                         goto done;
 966         }
 967         buffer = eol + 1;
 968
 969         if (!skip_prefix(buffer, "tagger ", &buffer)) {
 970                 /* early tags do not contain 'tagger' lines; warn only */
 971                 ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
 972                 if (ret)
 973                         goto done;
 974         }
 975         else
 976                 ret = fsck_ident(&buffer, oid, OBJ_TAG, options);
 977
 978 done:
 979         strbuf_release(&sb);
 980         return ret;
 981 }
 982
 983 /*
 984  * Like builtin/submodule--helper.c's starts_with_dot_slash, but without
 985  * relying on the platform-dependent is_dir_sep helper.
 986  *
 987  * This is for use in checking whether a submodule URL is interpreted as
 988  * relative to the current directory on any platform, since \ is a
 989  * directory separator on Windows but not on other platforms.
 990  */
 991 static int starts_with_dot_slash(const char *str)
 992 {
 993         return str[0] == '.' && (str[1] == '/' || str[1] == '\\');
 994 }
 995
 996 /*
 997  * Like starts_with_dot_slash, this is a variant of submodule--helper's
 998  * helper of the same name with the twist that it accepts backslash as a
 999  * directory separator even on non-Windows platforms.
1000  */
1001 static int starts_with_dot_dot_slash(const char *str)
1002 {
1003         return str[0] == '.' && starts_with_dot_slash(str + 1);
1004 }
1005
1006 static int submodule_url_is_relative(const char *url)
1007 {
1008         return starts_with_dot_slash(url) || starts_with_dot_dot_slash(url);
1009 }
1010
1011 /*
1012  * Count directory components that a relative submodule URL should chop
1013  * from the remote_url it is to be resolved against.
1014  *
1015  * In other words, this counts "../" components at the start of a
1016  * submodule URL.
1017  *
1018  * Returns the number of directory components to chop and writes a
1019  * pointer to the next character of url after all leading "./" and
1020  * "../" components to out.
1021  */
1022 static int count_leading_dotdots(const char *url, const char **out)
1023 {
1024         int result = 0;
1025         while (1) {
1026                 if (starts_with_dot_dot_slash(url)) {
1027                         result++;
1028                         url += strlen("../");
1029                         continue;
1030                 }
1031                 if (starts_with_dot_slash(url)) {
1032                         url += strlen("./");
1033                         continue;
1034                 }
1035                 *out = url;
1036                 return result;
1037         }
1038 }
1039 /*
1040  * Check whether a transport is implemented by git-remote-curl.
1041  *
1042  * If it is, returns 1 and writes the URL that would be passed to
1043  * git-remote-curl to the "out" parameter.
1044  *
1045  * Otherwise, returns 0 and leaves "out" untouched.
1046  *
1047  * Examples:
1048  *   http::https://example.com/repo.git -> 1, https://example.com/repo.git
1049  *   https://example.com/repo.git -> 1, https://example.com/repo.git
1050  *   git://example.com/repo.git -> 0
1051  *
1052  * This is for use in checking for previously exploitable bugs that
1053  * required a submodule URL to be passed to git-remote-curl.
1054  */
1055 static int url_to_curl_url(const char *url, const char **out)
1056 {
1057         /*
1058          * We don't need to check for case-aliases, "http.exe", and so
1059          * on because in the default configuration, is_transport_allowed
1060          * prevents URLs with those schemes from being cloned
1061          * automatically.
1062          */
1063         if (skip_prefix(url, "http::", out) ||
1064             skip_prefix(url, "https::", out) ||
1065             skip_prefix(url, "ftp::", out) ||
1066             skip_prefix(url, "ftps::", out))
1067                 return 1;
1068         if (starts_with(url, "http://") ||
1069             starts_with(url, "https://") ||
1070             starts_with(url, "ftp://") ||
1071             starts_with(url, "ftps://")) {
1072                 *out = url;
1073                 return 1;
1074         }
1075         return 0;
1076 }
1077
1078 static int check_submodule_url(const char *url)
1079 {
1080         const char *curl_url;
1081
1082         if (looks_like_command_line_option(url))
1083                 return -1;
1084
1085         if (submodule_url_is_relative(url)) {
1086                 char *decoded;
1087                 const char *next;
1088                 int has_nl;
1089
1090                 /*
1091                  * This could be appended to an http URL and url-decoded;
1092                  * check for malicious characters.
1093                  */
1094                 decoded = url_decode(url);
1095                 has_nl = !!strchr(decoded, '\n');
1096
1097                 free(decoded);
1098                 if (has_nl)
1099                         return -1;
1100
1101                 /*
1102                  * URLs which escape their root via "../" can overwrite
1103                  * the host field and previous components, resolving to
1104                  * URLs like https::example.com/submodule.git and
1105                  * https:///example.com/submodule.git that were
1106                  * susceptible to CVE-2020-11008.
1107                  */
1108                 if (count_leading_dotdots(url, &next) > 0 &&
1109                     (*next == ':' || *next == '/'))
1110                         return -1;
1111         }
1112
1113         else if (url_to_curl_url(url, &curl_url)) {
1114                 struct credential c = CREDENTIAL_INIT;
1115                 int ret = 0;
1116                 if (credential_from_url_gently(&c, curl_url, 1) ||
1117                     !*c.host)
1118                         ret = -1;
1119                 credential_clear(&c);
1120                 return ret;
1121         }
1122
1123         return 0;
1124 }
1125
1126 struct fsck_gitmodules_data {
1127         const struct object_id *oid;
1128         struct fsck_options *options;
1129         int ret;
1130 };
1131
1132 static int fsck_gitmodules_fn(const char *var, const char *value, void *vdata)
1133 {
1134         struct fsck_gitmodules_data *data = vdata;
1135         const char *subsection, *key;
1136         size_t subsection_len;
1137         char *name;
1138
1139         if (parse_config_key(var, "submodule", &subsection, &subsection_len, &key) < 0 ||
1140             !subsection)
1141                 return 0;
1142
1143         name = xmemdupz(subsection, subsection_len);
1144         if (check_submodule_name(name) < 0)
1145                 data->ret |= report(data->options,
1146                                     data->oid, OBJ_BLOB,
1147                                     FSCK_MSG_GITMODULES_NAME,
1148                                     "disallowed submodule name: %s",
1149                                     name);
1150         if (!strcmp(key, "url") && value &&
1151             check_submodule_url(value) < 0)
1152                 data->ret |= report(data->options,
1153                                     data->oid, OBJ_BLOB,
1154                                     FSCK_MSG_GITMODULES_URL,
1155                                     "disallowed submodule url: %s",
1156                                     value);
1157         if (!strcmp(key, "path") && value &&
1158             looks_like_command_line_option(value))
1159                 data->ret |= report(data->options,
1160                                     data->oid, OBJ_BLOB,
1161                                     FSCK_MSG_GITMODULES_PATH,
1162                                     "disallowed submodule path: %s",
1163                                     value);
1164         if (!strcmp(key, "update") && value &&
1165             parse_submodule_update_type(value) == SM_UPDATE_COMMAND)
1166                 data->ret |= report(data->options, data->oid, OBJ_BLOB,
1167                                     FSCK_MSG_GITMODULES_UPDATE,
1168                                     "disallowed submodule update setting: %s",
1169                                     value);
1170         free(name);
1171
1172         return 0;
1173 }
1174
1175 static int fsck_blob(const struct object_id *oid, const char *buf,
1176                      unsigned long size, struct fsck_options *options)
1177 {
1178         struct fsck_gitmodules_data data;
1179         struct config_options config_opts = { 0 };
1180
1181         if (!oidset_contains(&gitmodules_found, oid))
1182                 return 0;
1183         oidset_insert(&gitmodules_done, oid);
1184
1185         if (object_on_skiplist(options, oid))
1186                 return 0;
1187
1188         if (!buf) {
1189                 /*
1190                  * A missing buffer here is a sign that the caller found the
1191                  * blob too gigantic to load into memory. Let's just consider
1192                  * that an error.
1193                  */
1194                 return report(options, oid, OBJ_BLOB,
1195                               FSCK_MSG_GITMODULES_LARGE,
1196                               ".gitmodules too large to parse");
1197         }
1198
1199         data.oid = oid;
1200         data.options = options;
1201         data.ret = 0;
1202         config_opts.error_action = CONFIG_ERROR_SILENT;
1203         if (git_config_from_mem(fsck_gitmodules_fn, CONFIG_ORIGIN_BLOB,
1204                                 ".gitmodules", buf, size, &data, &config_opts))
1205                 data.ret |= report(options, oid, OBJ_BLOB,
1206                                    FSCK_MSG_GITMODULES_PARSE,
1207                                    "could not parse gitmodules blob");
1208
1209         return data.ret;
1210 }
1211
1212 int fsck_object(struct object *obj, void *data, unsigned long size,
1213         struct fsck_options *options)
1214 {
1215         if (!obj)
1216                 return report(options, NULL, OBJ_NONE, FSCK_MSG_BAD_OBJECT_SHA1, "no valid object to fsck");
1217
1218         if (obj->type == OBJ_BLOB)
1219                 return fsck_blob(&obj->oid, data, size, options);
1220         if (obj->type == OBJ_TREE)
1221                 return fsck_tree(&obj->oid, data, size, options);
1222         if (obj->type == OBJ_COMMIT)
1223                 return fsck_commit(&obj->oid, data, size, options);
1224         if (obj->type == OBJ_TAG)
1225                 return fsck_tag(&obj->oid, data, size, options);
1226
1227         return report(options, &obj->oid, obj->type,
1228                       FSCK_MSG_UNKNOWN_TYPE,
1229                       "unknown type '%d' (internal fsck error)",
1230                       obj->type);
1231 }
1232
1233 int fsck_error_function(struct fsck_options *o,
1234                         const struct object_id *oid,
1235                         enum object_type object_type,
1236                         int msg_type, const char *message)
1237 {
1238         if (msg_type == FSCK_WARN) {
1239                 warning("object %s: %s", fsck_describe_object(o, oid), message);
1240                 return 0;
1241         }
1242         error("object %s: %s", fsck_describe_object(o, oid), message);
1243         return 1;
1244 }
1245
1246 int fsck_finish(struct fsck_options *options)
1247 {
1248         int ret = 0;
1249         struct oidset_iter iter;
1250         const struct object_id *oid;
1251
1252         oidset_iter_init(&gitmodules_found, &iter);
1253         while ((oid = oidset_iter_next(&iter))) {
1254                 enum object_type type;
1255                 unsigned long size;
1256                 char *buf;
1257
1258                 if (oidset_contains(&gitmodules_done, oid))
1259                         continue;
1260
1261                 buf = read_object_file(oid, &type, &size);
1262                 if (!buf) {
1263                         if (is_promisor_object(oid))
1264                                 continue;
1265                         ret |= report(options,
1266                                       oid, OBJ_BLOB,
1267                                       FSCK_MSG_GITMODULES_MISSING,
1268                                       "unable to read .gitmodules blob");
1269                         continue;
1270                 }
1271
1272                 if (type == OBJ_BLOB)
1273                         ret |= fsck_blob(oid, buf, size, options);
1274                 else
1275                         ret |= report(options,
1276                                       oid, type,
1277                                       FSCK_MSG_GITMODULES_BLOB,
1278                                       "non-blob found at .gitmodules");
1279                 free(buf);
1280         }
1281
1282
1283         oidset_clear(&gitmodules_found);
1284         oidset_clear(&gitmodules_done);
1285         return ret;
1286 }