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
  14 #define FSCK_FATAL -1
  15 #define FSCK_INFO -2
  16
  17 #define FOREACH_MSG_ID(FUNC) \
  18         /* fatal errors */ \
  19         FUNC(NUL_IN_HEADER, FATAL) \
  20         FUNC(UNTERMINATED_HEADER, FATAL) \
  21         /* errors */ \
  22         FUNC(BAD_DATE, ERROR) \
  23         FUNC(BAD_DATE_OVERFLOW, ERROR) \
  24         FUNC(BAD_EMAIL, ERROR) \
  25         FUNC(BAD_NAME, ERROR) \
  26         FUNC(BAD_OBJECT_SHA1, ERROR) \
  27         FUNC(BAD_PARENT_SHA1, ERROR) \
  28         FUNC(BAD_TAG_OBJECT, ERROR) \
  29         FUNC(BAD_TIMEZONE, ERROR) \
  30         FUNC(BAD_TREE, ERROR) \
  31         FUNC(BAD_TREE_SHA1, ERROR) \
  32         FUNC(BAD_TYPE, ERROR) \
  33         FUNC(DUPLICATE_ENTRIES, ERROR) \
  34         FUNC(MISSING_AUTHOR, ERROR) \
  35         FUNC(MISSING_COMMITTER, ERROR) \
  36         FUNC(MISSING_EMAIL, ERROR) \
  37         FUNC(MISSING_GRAFT, ERROR) \
  38         FUNC(MISSING_NAME_BEFORE_EMAIL, ERROR) \
  39         FUNC(MISSING_OBJECT, ERROR) \
  40         FUNC(MISSING_PARENT, ERROR) \
  41         FUNC(MISSING_SPACE_BEFORE_DATE, ERROR) \
  42         FUNC(MISSING_SPACE_BEFORE_EMAIL, ERROR) \
  43         FUNC(MISSING_TAG, ERROR) \
  44         FUNC(MISSING_TAG_ENTRY, ERROR) \
  45         FUNC(MISSING_TAG_OBJECT, ERROR) \
  46         FUNC(MISSING_TREE, ERROR) \
  47         FUNC(MISSING_TYPE, ERROR) \
  48         FUNC(MISSING_TYPE_ENTRY, ERROR) \
  49         FUNC(MULTIPLE_AUTHORS, ERROR) \
  50         FUNC(TAG_OBJECT_NOT_TAG, ERROR) \
  51         FUNC(TREE_NOT_SORTED, ERROR) \
  52         FUNC(UNKNOWN_TYPE, ERROR) \
  53         FUNC(ZERO_PADDED_DATE, ERROR) \
  54         /* warnings */ \
  55         FUNC(BAD_FILEMODE, WARN) \
  56         FUNC(EMPTY_NAME, WARN) \
  57         FUNC(FULL_PATHNAME, WARN) \
  58         FUNC(HAS_DOT, WARN) \
  59         FUNC(HAS_DOTDOT, WARN) \
  60         FUNC(HAS_DOTGIT, WARN) \
  61         FUNC(NULL_SHA1, WARN) \
  62         FUNC(ZERO_PADDED_FILEMODE, WARN) \
  63         FUNC(NUL_IN_COMMIT, WARN) \
  64         /* infos (reported as warnings, but ignored by default) */ \
  65         FUNC(BAD_TAG_NAME, INFO) \
  66         FUNC(MISSING_TAGGER_ENTRY, INFO)
  67
  68 #define MSG_ID(id, msg_type) FSCK_MSG_##id,
  69 enum fsck_msg_id {
  70         FOREACH_MSG_ID(MSG_ID)
  71         FSCK_MSG_MAX
  72 };
  73 #undef MSG_ID
  74
  75 #define STR(x) #x
  76 #define MSG_ID(id, msg_type) { STR(id), NULL, FSCK_##msg_type },
  77 static struct {
  78         const char *id_string;
  79         const char *downcased;
  80         int msg_type;
  81 } msg_id_info[FSCK_MSG_MAX + 1] = {
  82         FOREACH_MSG_ID(MSG_ID)
  83         { NULL, NULL, -1 }
  84 };
  85 #undef MSG_ID
  86
  87 static int parse_msg_id(const char *text)
  88 {
  89         int i;
  90
  91         if (!msg_id_info[0].downcased) {
  92                 /* convert id_string to lower case, without underscores. */
  93                 for (i = 0; i < FSCK_MSG_MAX; i++) {
  94                         const char *p = msg_id_info[i].id_string;
  95                         int len = strlen(p);
  96                         char *q = xmalloc(len);
  97
  98                         msg_id_info[i].downcased = q;
  99                         while (*p)
 100                                 if (*p == '_')
 101                                         p++;
 102                                 else
 103                                         *(q)++ = tolower(*(p)++);
 104                         *q = '\0';
 105                 }
 106         }
 107
 108         for (i = 0; i < FSCK_MSG_MAX; i++)
 109                 if (!strcmp(text, msg_id_info[i].downcased))
 110                         return i;
 111
 112         return -1;
 113 }
 114
 115 static int fsck_msg_type(enum fsck_msg_id msg_id,
 116         struct fsck_options *options)
 117 {
 118         int msg_type;
 119
 120         assert(msg_id >= 0 && msg_id < FSCK_MSG_MAX);
 121
 122         if (options->msg_type)
 123                 msg_type = options->msg_type[msg_id];
 124         else {
 125                 msg_type = msg_id_info[msg_id].msg_type;
 126                 if (options->strict && msg_type == FSCK_WARN)
 127                         msg_type = FSCK_ERROR;
 128         }
 129
 130         return msg_type;
 131 }
 132
 133 static void init_skiplist(struct fsck_options *options, const char *path)
 134 {
 135         static struct sha1_array skiplist = SHA1_ARRAY_INIT;
 136         int sorted, fd;
 137         char buffer[41];
 138         unsigned char sha1[20];
 139
 140         if (options->skiplist)
 141                 sorted = options->skiplist->sorted;
 142         else {
 143                 sorted = 1;
 144                 options->skiplist = &skiplist;
 145         }
 146
 147         fd = open(path, O_RDONLY);
 148         if (fd < 0)
 149                 die("Could not open skip list: %s", path);
 150         for (;;) {
 151                 int result = read_in_full(fd, buffer, sizeof(buffer));
 152                 if (result < 0)
 153                         die_errno("Could not read '%s'", path);
 154                 if (!result)
 155                         break;
 156                 if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n')
 157                         die("Invalid SHA-1: %s", buffer);
 158                 sha1_array_append(&skiplist, sha1);
 159                 if (sorted && skiplist.nr > 1 &&
 160                                 hashcmp(skiplist.sha1[skiplist.nr - 2],
 161                                         sha1) > 0)
 162                         sorted = 0;
 163         }
 164         close(fd);
 165
 166         if (sorted)
 167                 skiplist.sorted = 1;
 168 }
 169
 170 static int parse_msg_type(const char *str)
 171 {
 172         if (!strcmp(str, "error"))
 173                 return FSCK_ERROR;
 174         else if (!strcmp(str, "warn"))
 175                 return FSCK_WARN;
 176         else if (!strcmp(str, "ignore"))
 177                 return FSCK_IGNORE;
 178         else
 179                 die("Unknown fsck message type: '%s'", str);
 180 }
 181
 182 int is_valid_msg_type(const char *msg_id, const char *msg_type)
 183 {
 184         if (parse_msg_id(msg_id) < 0)
 185                 return 0;
 186         parse_msg_type(msg_type);
 187         return 1;
 188 }
 189
 190 void fsck_set_msg_type(struct fsck_options *options,
 191                 const char *msg_id, const char *msg_type)
 192 {
 193         int id = parse_msg_id(msg_id), type;
 194
 195         if (id < 0)
 196                 die("Unhandled message id: %s", msg_id);
 197         type = parse_msg_type(msg_type);
 198
 199         if (type != FSCK_ERROR && msg_id_info[id].msg_type == FSCK_FATAL)
 200                 die("Cannot demote %s to %s", msg_id, msg_type);
 201
 202         if (!options->msg_type) {
 203                 int i;
 204                 int *msg_type;
 205                 ALLOC_ARRAY(msg_type, FSCK_MSG_MAX);
 206                 for (i = 0; i < FSCK_MSG_MAX; i++)
 207                         msg_type[i] = fsck_msg_type(i, options);
 208                 options->msg_type = msg_type;
 209         }
 210
 211         options->msg_type[id] = type;
 212 }
 213
 214 void fsck_set_msg_types(struct fsck_options *options, const char *values)
 215 {
 216         char *buf = xstrdup(values), *to_free = buf;
 217         int done = 0;
 218
 219         while (!done) {
 220                 int len = strcspn(buf, " ,|"), equal;
 221
 222                 done = !buf[len];
 223                 if (!len) {
 224                         buf++;
 225                         continue;
 226                 }
 227                 buf[len] = '\0';
 228
 229                 for (equal = 0;
 230                      equal < len && buf[equal] != '=' && buf[equal] != ':';
 231                      equal++)
 232                         buf[equal] = tolower(buf[equal]);
 233                 buf[equal] = '\0';
 234
 235                 if (!strcmp(buf, "skiplist")) {
 236                         if (equal == len)
 237                                 die("skiplist requires a path");
 238                         init_skiplist(options, buf + equal + 1);
 239                         buf += len + 1;
 240                         continue;
 241                 }
 242
 243                 if (equal == len)
 244                         die("Missing '=': '%s'", buf);
 245
 246                 fsck_set_msg_type(options, buf, buf + equal + 1);
 247                 buf += len + 1;
 248         }
 249         free(to_free);
 250 }
 251
 252 static void append_msg_id(struct strbuf *sb, const char *msg_id)
 253 {
 254         for (;;) {
 255                 char c = *(msg_id)++;
 256
 257                 if (!c)
 258                         break;
 259                 if (c != '_')
 260                         strbuf_addch(sb, tolower(c));
 261                 else {
 262                         assert(*msg_id);
 263                         strbuf_addch(sb, *(msg_id)++);
 264                 }
 265         }
 266
 267         strbuf_addstr(sb, ": ");
 268 }
 269
 270 __attribute__((format (printf, 4, 5)))
 271 static int report(struct fsck_options *options, struct object *object,
 272         enum fsck_msg_id id, const char *fmt, ...)
 273 {
 274         va_list ap;
 275         struct strbuf sb = STRBUF_INIT;
 276         int msg_type = fsck_msg_type(id, options), result;
 277
 278         if (msg_type == FSCK_IGNORE)
 279                 return 0;
 280
 281         if (options->skiplist && object &&
 282                         sha1_array_lookup(options->skiplist, object->oid.hash) >= 0)
 283                 return 0;
 284
 285         if (msg_type == FSCK_FATAL)
 286                 msg_type = FSCK_ERROR;
 287         else if (msg_type == FSCK_INFO)
 288                 msg_type = FSCK_WARN;
 289
 290         append_msg_id(&sb, msg_id_info[id].id_string);
 291
 292         va_start(ap, fmt);
 293         strbuf_vaddf(&sb, fmt, ap);
 294         result = options->error_func(options, object, msg_type, sb.buf);
 295         strbuf_release(&sb);
 296         va_end(ap);
 297
 298         return result;
 299 }
 300
 301 static char *get_object_name(struct fsck_options *options, struct object *obj)
 302 {
 303         if (!options->object_names)
 304                 return NULL;
 305         return lookup_decoration(options->object_names, obj);
 306 }
 307
 308 static void put_object_name(struct fsck_options *options, struct object *obj,
 309         const char *fmt, ...)
 310 {
 311         va_list ap;
 312         struct strbuf buf = STRBUF_INIT;
 313         char *existing;
 314
 315         if (!options->object_names)
 316                 return;
 317         existing = lookup_decoration(options->object_names, obj);
 318         if (existing)
 319                 return;
 320         va_start(ap, fmt);
 321         strbuf_vaddf(&buf, fmt, ap);
 322         add_decoration(options->object_names, obj, strbuf_detach(&buf, NULL));
 323         va_end(ap);
 324 }
 325
 326 static const char *describe_object(struct fsck_options *o, struct object *obj)
 327 {
 328         static struct strbuf buf = STRBUF_INIT;
 329         char *name;
 330
 331         strbuf_reset(&buf);
 332         strbuf_addstr(&buf, oid_to_hex(&obj->oid));
 333         if (o->object_names && (name = lookup_decoration(o->object_names, obj)))
 334                 strbuf_addf(&buf, " (%s)", name);
 335
 336         return buf.buf;
 337 }
 338
 339 static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *options)
 340 {
 341         struct tree_desc desc;
 342         struct name_entry entry;
 343         int res = 0;
 344         const char *name;
 345
 346         if (parse_tree(tree))
 347                 return -1;
 348
 349         name = get_object_name(options, &tree->object);
 350         if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
 351                 return -1;
 352         while (tree_entry_gently(&desc, &entry)) {
 353                 struct object *obj;
 354                 int result;
 355
 356                 if (S_ISGITLINK(entry.mode))
 357                         continue;
 358
 359                 if (S_ISDIR(entry.mode)) {
 360                         obj = &lookup_tree(entry.oid->hash)->object;
 361                         if (name)
 362                                 put_object_name(options, obj, "%s%s/", name,
 363                                         entry.path);
 364                         result = options->walk(obj, OBJ_TREE, data, options);
 365                 }
 366                 else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode)) {
 367                         obj = &lookup_blob(entry.oid->hash)->object;
 368                         if (name)
 369                                 put_object_name(options, obj, "%s%s", name,
 370                                         entry.path);
 371                         result = options->walk(obj, OBJ_BLOB, data, options);
 372                 }
 373                 else {
 374                         result = error("in tree %s: entry %s has bad mode %.6o",
 375                                         describe_object(options, &tree->object), entry.path, entry.mode);
 376                 }
 377                 if (result < 0)
 378                         return result;
 379                 if (!res)
 380                         res = result;
 381         }
 382         return res;
 383 }
 384
 385 static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_options *options)
 386 {
 387         int counter = 0, generation = 0, name_prefix_len = 0;
 388         struct commit_list *parents;
 389         int res;
 390         int result;
 391         const char *name;
 392
 393         if (parse_commit(commit))
 394                 return -1;
 395
 396         name = get_object_name(options, &commit->object);
 397         if (name)
 398                 put_object_name(options, &commit->tree->object, "%s:", name);
 399
 400         result = options->walk((struct object *)commit->tree, OBJ_TREE, data, options);
 401         if (result < 0)
 402                 return result;
 403         res = result;
 404
 405         parents = commit->parents;
 406         if (name && parents) {
 407                 int len = strlen(name), power;
 408
 409                 if (len && name[len - 1] == '^') {
 410                         generation = 1;
 411                         name_prefix_len = len - 1;
 412                 }
 413                 else { /* parse ~<generation> suffix */
 414                         for (generation = 0, power = 1;
 415                              len && isdigit(name[len - 1]);
 416                              power *= 10)
 417                                 generation += power * (name[--len] - '0');
 418                         if (power > 1 && len && name[len - 1] == '~')
 419                                 name_prefix_len = len - 1;
 420                 }
 421         }
 422
 423         while (parents) {
 424                 if (name) {
 425                         struct object *obj = &parents->item->object;
 426
 427                         if (++counter > 1)
 428                                 put_object_name(options, obj, "%s^%d",
 429                                         name, counter);
 430                         else if (generation > 0)
 431                                 put_object_name(options, obj, "%.*s~%d",
 432                                         name_prefix_len, name, generation + 1);
 433                         else
 434                                 put_object_name(options, obj, "%s^", name);
 435                 }
 436                 result = options->walk((struct object *)parents->item, OBJ_COMMIT, data, options);
 437                 if (result < 0)
 438                         return result;
 439                 if (!res)
 440                         res = result;
 441                 parents = parents->next;
 442         }
 443         return res;
 444 }
 445
 446 static int fsck_walk_tag(struct tag *tag, void *data, struct fsck_options *options)
 447 {
 448         char *name = get_object_name(options, &tag->object);
 449
 450         if (parse_tag(tag))
 451                 return -1;
 452         if (name)
 453                 put_object_name(options, tag->tagged, "%s", name);
 454         return options->walk(tag->tagged, OBJ_ANY, data, options);
 455 }
 456
 457 int fsck_walk(struct object *obj, void *data, struct fsck_options *options)
 458 {
 459         if (!obj)
 460                 return -1;
 461
 462         if (obj->type == OBJ_NONE)
 463                 parse_object(obj->oid.hash);
 464
 465         switch (obj->type) {
 466         case OBJ_BLOB:
 467                 return 0;
 468         case OBJ_TREE:
 469                 return fsck_walk_tree((struct tree *)obj, data, options);
 470         case OBJ_COMMIT:
 471                 return fsck_walk_commit((struct commit *)obj, data, options);
 472         case OBJ_TAG:
 473                 return fsck_walk_tag((struct tag *)obj, data, options);
 474         default:
 475                 error("Unknown object type for %s", describe_object(options, obj));
 476                 return -1;
 477         }
 478 }
 479
 480 /*
 481  * The entries in a tree are ordered in the _path_ order,
 482  * which means that a directory entry is ordered by adding
 483  * a slash to the end of it.
 484  *
 485  * So a directory called "a" is ordered _after_ a file
 486  * called "a.c", because "a/" sorts after "a.c".
 487  */
 488 #define TREE_UNORDERED (-1)
 489 #define TREE_HAS_DUPS  (-2)
 490
 491 static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
 492 {
 493         int len1 = strlen(name1);
 494         int len2 = strlen(name2);
 495         int len = len1 < len2 ? len1 : len2;
 496         unsigned char c1, c2;
 497         int cmp;
 498
 499         cmp = memcmp(name1, name2, len);
 500         if (cmp < 0)
 501                 return 0;
 502         if (cmp > 0)
 503                 return TREE_UNORDERED;
 504
 505         /*
 506          * Ok, the first <len> characters are the same.
 507          * Now we need to order the next one, but turn
 508          * a '\0' into a '/' for a directory entry.
 509          */
 510         c1 = name1[len];
 511         c2 = name2[len];
 512         if (!c1 && !c2)
 513                 /*
 514                  * git-write-tree used to write out a nonsense tree that has
 515                  * entries with the same name, one blob and one tree.  Make
 516                  * sure we do not have duplicate entries.
 517                  */
 518                 return TREE_HAS_DUPS;
 519         if (!c1 && S_ISDIR(mode1))
 520                 c1 = '/';
 521         if (!c2 && S_ISDIR(mode2))
 522                 c2 = '/';
 523         return c1 < c2 ? 0 : TREE_UNORDERED;
 524 }
 525
 526 static int fsck_tree(struct tree *item, struct fsck_options *options)
 527 {
 528         int retval = 0;
 529         int has_null_sha1 = 0;
 530         int has_full_path = 0;
 531         int has_empty_name = 0;
 532         int has_dot = 0;
 533         int has_dotdot = 0;
 534         int has_dotgit = 0;
 535         int has_zero_pad = 0;
 536         int has_bad_modes = 0;
 537         int has_dup_entries = 0;
 538         int not_properly_sorted = 0;
 539         struct tree_desc desc;
 540         unsigned o_mode;
 541         const char *o_name;
 542
 543         if (init_tree_desc_gently(&desc, item->buffer, item->size)) {
 544                 retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
 545                 return retval;
 546         }
 547
 548         o_mode = 0;
 549         o_name = NULL;
 550
 551         while (desc.size) {
 552                 unsigned mode;
 553                 const char *name;
 554                 const struct object_id *oid;
 555
 556                 oid = tree_entry_extract(&desc, &name, &mode);
 557
 558                 has_null_sha1 |= is_null_oid(oid);
 559                 has_full_path |= !!strchr(name, '/');
 560                 has_empty_name |= !*name;
 561                 has_dot |= !strcmp(name, ".");
 562                 has_dotdot |= !strcmp(name, "..");
 563                 has_dotgit |= (!strcmp(name, ".git") ||
 564                                is_hfs_dotgit(name) ||
 565                                is_ntfs_dotgit(name));
 566                 has_zero_pad |= *(char *)desc.buffer == '0';
 567                 if (update_tree_entry_gently(&desc)) {
 568                         retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
 569                         break;
 570                 }
 571
 572                 switch (mode) {
 573                 /*
 574                  * Standard modes..
 575                  */
 576                 case S_IFREG | 0755:
 577                 case S_IFREG | 0644:
 578                 case S_IFLNK:
 579                 case S_IFDIR:
 580                 case S_IFGITLINK:
 581                         break;
 582                 /*
 583                  * This is nonstandard, but we had a few of these
 584                  * early on when we honored the full set of mode
 585                  * bits..
 586                  */
 587                 case S_IFREG | 0664:
 588                         if (!options->strict)
 589                                 break;
 590                 default:
 591                         has_bad_modes = 1;
 592                 }
 593
 594                 if (o_name) {
 595                         switch (verify_ordered(o_mode, o_name, mode, name)) {
 596                         case TREE_UNORDERED:
 597                                 not_properly_sorted = 1;
 598                                 break;
 599                         case TREE_HAS_DUPS:
 600                                 has_dup_entries = 1;
 601                                 break;
 602                         default:
 603                                 break;
 604                         }
 605                 }
 606
 607                 o_mode = mode;
 608                 o_name = name;
 609         }
 610
 611         if (has_null_sha1)
 612                 retval += report(options, &item->object, FSCK_MSG_NULL_SHA1, "contains entries pointing to null sha1");
 613         if (has_full_path)
 614                 retval += report(options, &item->object, FSCK_MSG_FULL_PATHNAME, "contains full pathnames");
 615         if (has_empty_name)
 616                 retval += report(options, &item->object, FSCK_MSG_EMPTY_NAME, "contains empty pathname");
 617         if (has_dot)
 618                 retval += report(options, &item->object, FSCK_MSG_HAS_DOT, "contains '.'");
 619         if (has_dotdot)
 620                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTDOT, "contains '..'");
 621         if (has_dotgit)
 622                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTGIT, "contains '.git'");
 623         if (has_zero_pad)
 624                 retval += report(options, &item->object, FSCK_MSG_ZERO_PADDED_FILEMODE, "contains zero-padded file modes");
 625         if (has_bad_modes)
 626                 retval += report(options, &item->object, FSCK_MSG_BAD_FILEMODE, "contains bad file modes");
 627         if (has_dup_entries)
 628                 retval += report(options, &item->object, FSCK_MSG_DUPLICATE_ENTRIES, "contains duplicate file entries");
 629         if (not_properly_sorted)
 630                 retval += report(options, &item->object, FSCK_MSG_TREE_NOT_SORTED, "not properly sorted");
 631         return retval;
 632 }
 633
 634 static int verify_headers(const void *data, unsigned long size,
 635                           struct object *obj, struct fsck_options *options)
 636 {
 637         const char *buffer = (const char *)data;
 638         unsigned long i;
 639
 640         for (i = 0; i < size; i++) {
 641                 switch (buffer[i]) {
 642                 case '\0':
 643                         return report(options, obj,
 644                                 FSCK_MSG_NUL_IN_HEADER,
 645                                 "unterminated header: NUL at offset %ld", i);
 646                 case '\n':
 647                         if (i + 1 < size && buffer[i + 1] == '\n')
 648                                 return 0;
 649                 }
 650         }
 651
 652         /*
 653          * We did not find double-LF that separates the header
 654          * and the body.  Not having a body is not a crime but
 655          * we do want to see the terminating LF for the last header
 656          * line.
 657          */
 658         if (size && buffer[size - 1] == '\n')
 659                 return 0;
 660
 661         return report(options, obj,
 662                 FSCK_MSG_UNTERMINATED_HEADER, "unterminated header");
 663 }
 664
 665 static int fsck_ident(const char **ident, struct object *obj, struct fsck_options *options)
 666 {
 667         const char *p = *ident;
 668         char *end;
 669
 670         *ident = strchrnul(*ident, '\n');
 671         if (**ident == '\n')
 672                 (*ident)++;
 673
 674         if (*p == '<')
 675                 return report(options, obj, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 676         p += strcspn(p, "<>\n");
 677         if (*p == '>')
 678                 return report(options, obj, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
 679         if (*p != '<')
 680                 return report(options, obj, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
 681         if (p[-1] != ' ')
 682                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 683         p++;
 684         p += strcspn(p, "<>\n");
 685         if (*p != '>')
 686                 return report(options, obj, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
 687         p++;
 688         if (*p != ' ')
 689                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
 690         p++;
 691         if (*p == '0' && p[1] != ' ')
 692                 return report(options, obj, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
 693         if (date_overflows(strtoul(p, &end, 10)))
 694                 return report(options, obj, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
 695         if ((end == p || *end != ' '))
 696                 return report(options, obj, FSCK_MSG_BAD_DATE, "invalid author/committer line - bad date");
 697         p = end + 1;
 698         if ((*p != '+' && *p != '-') ||
 699             !isdigit(p[1]) ||
 700             !isdigit(p[2]) ||
 701             !isdigit(p[3]) ||
 702             !isdigit(p[4]) ||
 703             (p[5] != '\n'))
 704                 return report(options, obj, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
 705         p += 6;
 706         return 0;
 707 }
 708
 709 static int fsck_commit_buffer(struct commit *commit, const char *buffer,
 710         unsigned long size, struct fsck_options *options)
 711 {
 712         unsigned char tree_sha1[20], sha1[20];
 713         struct commit_graft *graft;
 714         unsigned parent_count, parent_line_count = 0, author_count;
 715         int err;
 716         const char *buffer_begin = buffer;
 717
 718         if (verify_headers(buffer, size, &commit->object, options))
 719                 return -1;
 720
 721         if (!skip_prefix(buffer, "tree ", &buffer))
 722                 return report(options, &commit->object, FSCK_MSG_MISSING_TREE, "invalid format - expected 'tree' line");
 723         if (get_sha1_hex(buffer, tree_sha1) || buffer[40] != '\n') {
 724                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE_SHA1, "invalid 'tree' line format - bad sha1");
 725                 if (err)
 726                         return err;
 727         }
 728         buffer += 41;
 729         while (skip_prefix(buffer, "parent ", &buffer)) {
 730                 if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n') {
 731                         err = report(options, &commit->object, FSCK_MSG_BAD_PARENT_SHA1, "invalid 'parent' line format - bad sha1");
 732                         if (err)
 733                                 return err;
 734                 }
 735                 buffer += 41;
 736                 parent_line_count++;
 737         }
 738         graft = lookup_commit_graft(commit->object.oid.hash);
 739         parent_count = commit_list_count(commit->parents);
 740         if (graft) {
 741                 if (graft->nr_parent == -1 && !parent_count)
 742                         ; /* shallow commit */
 743                 else if (graft->nr_parent != parent_count) {
 744                         err = report(options, &commit->object, FSCK_MSG_MISSING_GRAFT, "graft objects missing");
 745                         if (err)
 746                                 return err;
 747                 }
 748         } else {
 749                 if (parent_count != parent_line_count) {
 750                         err = report(options, &commit->object, FSCK_MSG_MISSING_PARENT, "parent objects missing");
 751                         if (err)
 752                                 return err;
 753                 }
 754         }
 755         author_count = 0;
 756         while (skip_prefix(buffer, "author ", &buffer)) {
 757                 author_count++;
 758                 err = fsck_ident(&buffer, &commit->object, options);
 759                 if (err)
 760                         return err;
 761         }
 762         if (author_count < 1)
 763                 err = report(options, &commit->object, FSCK_MSG_MISSING_AUTHOR, "invalid format - expected 'author' line");
 764         else if (author_count > 1)
 765                 err = report(options, &commit->object, FSCK_MSG_MULTIPLE_AUTHORS, "invalid format - multiple 'author' lines");
 766         if (err)
 767                 return err;
 768         if (!skip_prefix(buffer, "committer ", &buffer))
 769                 return report(options, &commit->object, FSCK_MSG_MISSING_COMMITTER, "invalid format - expected 'committer' line");
 770         err = fsck_ident(&buffer, &commit->object, options);
 771         if (err)
 772                 return err;
 773         if (!commit->tree) {
 774                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE, "could not load commit's tree %s", sha1_to_hex(tree_sha1));
 775                 if (err)
 776                         return err;
 777         }
 778         if (memchr(buffer_begin, '\0', size)) {
 779                 err = report(options, &commit->object, FSCK_MSG_NUL_IN_COMMIT,
 780                              "NUL byte in the commit object body");
 781                 if (err)
 782                         return err;
 783         }
 784         return 0;
 785 }
 786
 787 static int fsck_commit(struct commit *commit, const char *data,
 788         unsigned long size, struct fsck_options *options)
 789 {
 790         const char *buffer = data ?  data : get_commit_buffer(commit, &size);
 791         int ret = fsck_commit_buffer(commit, buffer, size, options);
 792         if (!data)
 793                 unuse_commit_buffer(commit, buffer);
 794         return ret;
 795 }
 796
 797 static int fsck_tag_buffer(struct tag *tag, const char *data,
 798         unsigned long size, struct fsck_options *options)
 799 {
 800         unsigned char sha1[20];
 801         int ret = 0;
 802         const char *buffer;
 803         char *to_free = NULL, *eol;
 804         struct strbuf sb = STRBUF_INIT;
 805
 806         if (data)
 807                 buffer = data;
 808         else {
 809                 enum object_type type;
 810
 811                 buffer = to_free =
 812                         read_sha1_file(tag->object.oid.hash, &type, &size);
 813                 if (!buffer)
 814                         return report(options, &tag->object,
 815                                 FSCK_MSG_MISSING_TAG_OBJECT,
 816                                 "cannot read tag object");
 817
 818                 if (type != OBJ_TAG) {
 819                         ret = report(options, &tag->object,
 820                                 FSCK_MSG_TAG_OBJECT_NOT_TAG,
 821                                 "expected tag got %s",
 822                             typename(type));
 823                         goto done;
 824                 }
 825         }
 826
 827         ret = verify_headers(buffer, size, &tag->object, options);
 828         if (ret)
 829                 goto done;
 830
 831         if (!skip_prefix(buffer, "object ", &buffer)) {
 832                 ret = report(options, &tag->object, FSCK_MSG_MISSING_OBJECT, "invalid format - expected 'object' line");
 833                 goto done;
 834         }
 835         if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n') {
 836                 ret = report(options, &tag->object, FSCK_MSG_BAD_OBJECT_SHA1, "invalid 'object' line format - bad sha1");
 837                 if (ret)
 838                         goto done;
 839         }
 840         buffer += 41;
 841
 842         if (!skip_prefix(buffer, "type ", &buffer)) {
 843                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE_ENTRY, "invalid format - expected 'type' line");
 844                 goto done;
 845         }
 846         eol = strchr(buffer, '\n');
 847         if (!eol) {
 848                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE, "invalid format - unexpected end after 'type' line");
 849                 goto done;
 850         }
 851         if (type_from_string_gently(buffer, eol - buffer, 1) < 0)
 852                 ret = report(options, &tag->object, FSCK_MSG_BAD_TYPE, "invalid 'type' value");
 853         if (ret)
 854                 goto done;
 855         buffer = eol + 1;
 856
 857         if (!skip_prefix(buffer, "tag ", &buffer)) {
 858                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG_ENTRY, "invalid format - expected 'tag' line");
 859                 goto done;
 860         }
 861         eol = strchr(buffer, '\n');
 862         if (!eol) {
 863                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG, "invalid format - unexpected end after 'type' line");
 864                 goto done;
 865         }
 866         strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer);
 867         if (check_refname_format(sb.buf, 0)) {
 868                 ret = report(options, &tag->object, FSCK_MSG_BAD_TAG_NAME,
 869                            "invalid 'tag' name: %.*s",
 870                            (int)(eol - buffer), buffer);
 871                 if (ret)
 872                         goto done;
 873         }
 874         buffer = eol + 1;
 875
 876         if (!skip_prefix(buffer, "tagger ", &buffer)) {
 877                 /* early tags do not contain 'tagger' lines; warn only */
 878                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
 879                 if (ret)
 880                         goto done;
 881         }
 882         else
 883                 ret = fsck_ident(&buffer, &tag->object, options);
 884
 885 done:
 886         strbuf_release(&sb);
 887         free(to_free);
 888         return ret;
 889 }
 890
 891 static int fsck_tag(struct tag *tag, const char *data,
 892         unsigned long size, struct fsck_options *options)
 893 {
 894         struct object *tagged = tag->tagged;
 895
 896         if (!tagged)
 897                 return report(options, &tag->object, FSCK_MSG_BAD_TAG_OBJECT, "could not load tagged object");
 898
 899         return fsck_tag_buffer(tag, data, size, options);
 900 }
 901
 902 int fsck_object(struct object *obj, void *data, unsigned long size,
 903         struct fsck_options *options)
 904 {
 905         if (!obj)
 906                 return report(options, obj, FSCK_MSG_BAD_OBJECT_SHA1, "no valid object to fsck");
 907
 908         if (obj->type == OBJ_BLOB)
 909                 return 0;
 910         if (obj->type == OBJ_TREE)
 911                 return fsck_tree((struct tree *) obj, options);
 912         if (obj->type == OBJ_COMMIT)
 913                 return fsck_commit((struct commit *) obj, (const char *) data,
 914                         size, options);
 915         if (obj->type == OBJ_TAG)
 916                 return fsck_tag((struct tag *) obj, (const char *) data,
 917                         size, options);
 918
 919         return report(options, obj, FSCK_MSG_UNKNOWN_TYPE, "unknown type '%d' (internal fsck error)",
 920                           obj->type);
 921 }
 922
 923 int fsck_error_function(struct fsck_options *o,
 924         struct object *obj, int msg_type, const char *message)
 925 {
 926         if (msg_type == FSCK_WARN) {
 927                 warning("object %s: %s", describe_object(o, obj), message);
 928                 return 0;
 929         }
 930         error("object %s: %s", describe_object(o, obj), message);
 931         return 1;
 932 }