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