Andrew's git / gitweb.git / fsck.c
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fsck.con commit Merge branch 'va/mailinfo-doc-typofix' into maint (31efe2a)
   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,
  67enum 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 },
  75static 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
  85static 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
 113static 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
 131static 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
 168static 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
 180int 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
 188void 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
 212void 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
 250static 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)))
 269static 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
 299static 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.sha1)->object, OBJ_TREE, data, options);
 316                else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode))
 317                        result = options->walk(&lookup_blob(entry.sha1)->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
 330static 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
 356static 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
 363int 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
 393static 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
 428static 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 unsigned char *sha1;
 454
 455                sha1 = tree_entry_extract(&desc, &name, &mode);
 456
 457                has_null_sha1 |= is_null_sha1(sha1);
 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
 531static 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
 562static 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
 606static 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
 675static 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
 685static 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
 773done:
 774        strbuf_release(&sb);
 775        free(to_free);
 776        return ret;
 777}
 778
 779static 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
 790int 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
 811int 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}