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