Andrew's git / gitweb.git / fsck.c
?
fsck.con commit Merge branch 'js/rebase-recreate-merge' (2c18e6a)
   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,
  69enum 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 },
  77static 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
  87static 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
 115static 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
 133static void init_skiplist(struct fsck_options *options, const char *path)
 134{
 135        static struct oid_array skiplist = OID_ARRAY_INIT;
 136        int sorted, fd;
 137        char buffer[GIT_MAX_HEXSZ + 1];
 138        struct object_id oid;
 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                const char *p;
 152                int result = read_in_full(fd, buffer, sizeof(buffer));
 153                if (result < 0)
 154                        die_errno("Could not read '%s'", path);
 155                if (!result)
 156                        break;
 157                if (parse_oid_hex(buffer, &oid, &p) || *p != '\n')
 158                        die("Invalid SHA-1: %s", buffer);
 159                oid_array_append(&skiplist, &oid);
 160                if (sorted && skiplist.nr > 1 &&
 161                                oidcmp(&skiplist.oid[skiplist.nr - 2],
 162                                       &oid) > 0)
 163                        sorted = 0;
 164        }
 165        close(fd);
 166
 167        if (sorted)
 168                skiplist.sorted = 1;
 169}
 170
 171static int parse_msg_type(const char *str)
 172{
 173        if (!strcmp(str, "error"))
 174                return FSCK_ERROR;
 175        else if (!strcmp(str, "warn"))
 176                return FSCK_WARN;
 177        else if (!strcmp(str, "ignore"))
 178                return FSCK_IGNORE;
 179        else
 180                die("Unknown fsck message type: '%s'", str);
 181}
 182
 183int is_valid_msg_type(const char *msg_id, const char *msg_type)
 184{
 185        if (parse_msg_id(msg_id) < 0)
 186                return 0;
 187        parse_msg_type(msg_type);
 188        return 1;
 189}
 190
 191void fsck_set_msg_type(struct fsck_options *options,
 192                const char *msg_id, const char *msg_type)
 193{
 194        int id = parse_msg_id(msg_id), type;
 195
 196        if (id < 0)
 197                die("Unhandled message id: %s", msg_id);
 198        type = parse_msg_type(msg_type);
 199
 200        if (type != FSCK_ERROR && msg_id_info[id].msg_type == FSCK_FATAL)
 201                die("Cannot demote %s to %s", msg_id, msg_type);
 202
 203        if (!options->msg_type) {
 204                int i;
 205                int *msg_type;
 206                ALLOC_ARRAY(msg_type, FSCK_MSG_MAX);
 207                for (i = 0; i < FSCK_MSG_MAX; i++)
 208                        msg_type[i] = fsck_msg_type(i, options);
 209                options->msg_type = msg_type;
 210        }
 211
 212        options->msg_type[id] = type;
 213}
 214
 215void fsck_set_msg_types(struct fsck_options *options, const char *values)
 216{
 217        char *buf = xstrdup(values), *to_free = buf;
 218        int done = 0;
 219
 220        while (!done) {
 221                int len = strcspn(buf, " ,|"), equal;
 222
 223                done = !buf[len];
 224                if (!len) {
 225                        buf++;
 226                        continue;
 227                }
 228                buf[len] = '\0';
 229
 230                for (equal = 0;
 231                     equal < len && buf[equal] != '=' && buf[equal] != ':';
 232                     equal++)
 233                        buf[equal] = tolower(buf[equal]);
 234                buf[equal] = '\0';
 235
 236                if (!strcmp(buf, "skiplist")) {
 237                        if (equal == len)
 238                                die("skiplist requires a path");
 239                        init_skiplist(options, buf + equal + 1);
 240                        buf += len + 1;
 241                        continue;
 242                }
 243
 244                if (equal == len)
 245                        die("Missing '=': '%s'", buf);
 246
 247                fsck_set_msg_type(options, buf, buf + equal + 1);
 248                buf += len + 1;
 249        }
 250        free(to_free);
 251}
 252
 253static void append_msg_id(struct strbuf *sb, const char *msg_id)
 254{
 255        for (;;) {
 256                char c = *(msg_id)++;
 257
 258                if (!c)
 259                        break;
 260                if (c != '_')
 261                        strbuf_addch(sb, tolower(c));
 262                else {
 263                        assert(*msg_id);
 264                        strbuf_addch(sb, *(msg_id)++);
 265                }
 266        }
 267
 268        strbuf_addstr(sb, ": ");
 269}
 270
 271__attribute__((format (printf, 4, 5)))
 272static int report(struct fsck_options *options, struct object *object,
 273        enum fsck_msg_id id, const char *fmt, ...)
 274{
 275        va_list ap;
 276        struct strbuf sb = STRBUF_INIT;
 277        int msg_type = fsck_msg_type(id, options), result;
 278
 279        if (msg_type == FSCK_IGNORE)
 280                return 0;
 281
 282        if (options->skiplist && object &&
 283                        oid_array_lookup(options->skiplist, &object->oid) >= 0)
 284                return 0;
 285
 286        if (msg_type == FSCK_FATAL)
 287                msg_type = FSCK_ERROR;
 288        else if (msg_type == FSCK_INFO)
 289                msg_type = FSCK_WARN;
 290
 291        append_msg_id(&sb, msg_id_info[id].id_string);
 292
 293        va_start(ap, fmt);
 294        strbuf_vaddf(&sb, fmt, ap);
 295        result = options->error_func(options, object, msg_type, sb.buf);
 296        strbuf_release(&sb);
 297        va_end(ap);
 298
 299        return result;
 300}
 301
 302static char *get_object_name(struct fsck_options *options, struct object *obj)
 303{
 304        if (!options->object_names)
 305                return NULL;
 306        return lookup_decoration(options->object_names, obj);
 307}
 308
 309static void put_object_name(struct fsck_options *options, struct object *obj,
 310        const char *fmt, ...)
 311{
 312        va_list ap;
 313        struct strbuf buf = STRBUF_INIT;
 314        char *existing;
 315
 316        if (!options->object_names)
 317                return;
 318        existing = lookup_decoration(options->object_names, obj);
 319        if (existing)
 320                return;
 321        va_start(ap, fmt);
 322        strbuf_vaddf(&buf, fmt, ap);
 323        add_decoration(options->object_names, obj, strbuf_detach(&buf, NULL));
 324        va_end(ap);
 325}
 326
 327static const char *describe_object(struct fsck_options *o, struct object *obj)
 328{
 329        static struct strbuf buf = STRBUF_INIT;
 330        char *name;
 331
 332        strbuf_reset(&buf);
 333        strbuf_addstr(&buf, oid_to_hex(&obj->oid));
 334        if (o->object_names && (name = lookup_decoration(o->object_names, obj)))
 335                strbuf_addf(&buf, " (%s)", name);
 336
 337        return buf.buf;
 338}
 339
 340static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *options)
 341{
 342        struct tree_desc desc;
 343        struct name_entry entry;
 344        int res = 0;
 345        const char *name;
 346
 347        if (parse_tree(tree))
 348                return -1;
 349
 350        name = get_object_name(options, &tree->object);
 351        if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
 352                return -1;
 353        while (tree_entry_gently(&desc, &entry)) {
 354                struct object *obj;
 355                int result;
 356
 357                if (S_ISGITLINK(entry.mode))
 358                        continue;
 359
 360                if (S_ISDIR(entry.mode)) {
 361                        obj = (struct object *)lookup_tree(entry.oid);
 362                        if (name && obj)
 363                                put_object_name(options, obj, "%s%s/", name,
 364                                        entry.path);
 365                        result = options->walk(obj, OBJ_TREE, data, options);
 366                }
 367                else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode)) {
 368                        obj = (struct object *)lookup_blob(entry.oid);
 369                        if (name && obj)
 370                                put_object_name(options, obj, "%s%s", name,
 371                                        entry.path);
 372                        result = options->walk(obj, OBJ_BLOB, data, options);
 373                }
 374                else {
 375                        result = error("in tree %s: entry %s has bad mode %.6o",
 376                                        describe_object(options, &tree->object), entry.path, entry.mode);
 377                }
 378                if (result < 0)
 379                        return result;
 380                if (!res)
 381                        res = result;
 382        }
 383        return res;
 384}
 385
 386static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_options *options)
 387{
 388        int counter = 0, generation = 0, name_prefix_len = 0;
 389        struct commit_list *parents;
 390        int res;
 391        int result;
 392        const char *name;
 393
 394        if (parse_commit(commit))
 395                return -1;
 396
 397        name = get_object_name(options, &commit->object);
 398        if (name)
 399                put_object_name(options, &get_commit_tree(commit)->object,
 400                                "%s:", name);
 401
 402        result = options->walk((struct object *)get_commit_tree(commit),
 403                               OBJ_TREE, data, options);
 404        if (result < 0)
 405                return result;
 406        res = result;
 407
 408        parents = commit->parents;
 409        if (name && parents) {
 410                int len = strlen(name), power;
 411
 412                if (len && name[len - 1] == '^') {
 413                        generation = 1;
 414                        name_prefix_len = len - 1;
 415                }
 416                else { /* parse ~<generation> suffix */
 417                        for (generation = 0, power = 1;
 418                             len && isdigit(name[len - 1]);
 419                             power *= 10)
 420                                generation += power * (name[--len] - '0');
 421                        if (power > 1 && len && name[len - 1] == '~')
 422                                name_prefix_len = len - 1;
 423                }
 424        }
 425
 426        while (parents) {
 427                if (name) {
 428                        struct object *obj = &parents->item->object;
 429
 430                        if (++counter > 1)
 431                                put_object_name(options, obj, "%s^%d",
 432                                        name, counter);
 433                        else if (generation > 0)
 434                                put_object_name(options, obj, "%.*s~%d",
 435                                        name_prefix_len, name, generation + 1);
 436                        else
 437                                put_object_name(options, obj, "%s^", name);
 438                }
 439                result = options->walk((struct object *)parents->item, OBJ_COMMIT, data, options);
 440                if (result < 0)
 441                        return result;
 442                if (!res)
 443                        res = result;
 444                parents = parents->next;
 445        }
 446        return res;
 447}
 448
 449static int fsck_walk_tag(struct tag *tag, void *data, struct fsck_options *options)
 450{
 451        char *name = get_object_name(options, &tag->object);
 452
 453        if (parse_tag(tag))
 454                return -1;
 455        if (name)
 456                put_object_name(options, tag->tagged, "%s", name);
 457        return options->walk(tag->tagged, OBJ_ANY, data, options);
 458}
 459
 460int fsck_walk(struct object *obj, void *data, struct fsck_options *options)
 461{
 462        if (!obj)
 463                return -1;
 464
 465        if (obj->type == OBJ_NONE)
 466                parse_object(&obj->oid);
 467
 468        switch (obj->type) {
 469        case OBJ_BLOB:
 470                return 0;
 471        case OBJ_TREE:
 472                return fsck_walk_tree((struct tree *)obj, data, options);
 473        case OBJ_COMMIT:
 474                return fsck_walk_commit((struct commit *)obj, data, options);
 475        case OBJ_TAG:
 476                return fsck_walk_tag((struct tag *)obj, data, options);
 477        default:
 478                error("Unknown object type for %s", describe_object(options, obj));
 479                return -1;
 480        }
 481}
 482
 483/*
 484 * The entries in a tree are ordered in the _path_ order,
 485 * which means that a directory entry is ordered by adding
 486 * a slash to the end of it.
 487 *
 488 * So a directory called "a" is ordered _after_ a file
 489 * called "a.c", because "a/" sorts after "a.c".
 490 */
 491#define TREE_UNORDERED (-1)
 492#define TREE_HAS_DUPS  (-2)
 493
 494static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
 495{
 496        int len1 = strlen(name1);
 497        int len2 = strlen(name2);
 498        int len = len1 < len2 ? len1 : len2;
 499        unsigned char c1, c2;
 500        int cmp;
 501
 502        cmp = memcmp(name1, name2, len);
 503        if (cmp < 0)
 504                return 0;
 505        if (cmp > 0)
 506                return TREE_UNORDERED;
 507
 508        /*
 509         * Ok, the first <len> characters are the same.
 510         * Now we need to order the next one, but turn
 511         * a '\0' into a '/' for a directory entry.
 512         */
 513        c1 = name1[len];
 514        c2 = name2[len];
 515        if (!c1 && !c2)
 516                /*
 517                 * git-write-tree used to write out a nonsense tree that has
 518                 * entries with the same name, one blob and one tree.  Make
 519                 * sure we do not have duplicate entries.
 520                 */
 521                return TREE_HAS_DUPS;
 522        if (!c1 && S_ISDIR(mode1))
 523                c1 = '/';
 524        if (!c2 && S_ISDIR(mode2))
 525                c2 = '/';
 526        return c1 < c2 ? 0 : TREE_UNORDERED;
 527}
 528
 529static int fsck_tree(struct tree *item, struct fsck_options *options)
 530{
 531        int retval = 0;
 532        int has_null_sha1 = 0;
 533        int has_full_path = 0;
 534        int has_empty_name = 0;
 535        int has_dot = 0;
 536        int has_dotdot = 0;
 537        int has_dotgit = 0;
 538        int has_zero_pad = 0;
 539        int has_bad_modes = 0;
 540        int has_dup_entries = 0;
 541        int not_properly_sorted = 0;
 542        struct tree_desc desc;
 543        unsigned o_mode;
 544        const char *o_name;
 545
 546        if (init_tree_desc_gently(&desc, item->buffer, item->size)) {
 547                retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
 548                return retval;
 549        }
 550
 551        o_mode = 0;
 552        o_name = NULL;
 553
 554        while (desc.size) {
 555                unsigned mode;
 556                const char *name;
 557                const struct object_id *oid;
 558
 559                oid = tree_entry_extract(&desc, &name, &mode);
 560
 561                has_null_sha1 |= is_null_oid(oid);
 562                has_full_path |= !!strchr(name, '/');
 563                has_empty_name |= !*name;
 564                has_dot |= !strcmp(name, ".");
 565                has_dotdot |= !strcmp(name, "..");
 566                has_dotgit |= (!strcmp(name, ".git") ||
 567                               is_hfs_dotgit(name) ||
 568                               is_ntfs_dotgit(name));
 569                has_zero_pad |= *(char *)desc.buffer == '0';
 570                if (update_tree_entry_gently(&desc)) {
 571                        retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
 572                        break;
 573                }
 574
 575                switch (mode) {
 576                /*
 577                 * Standard modes..
 578                 */
 579                case S_IFREG | 0755:
 580                case S_IFREG | 0644:
 581                case S_IFLNK:
 582                case S_IFDIR:
 583                case S_IFGITLINK:
 584                        break;
 585                /*
 586                 * This is nonstandard, but we had a few of these
 587                 * early on when we honored the full set of mode
 588                 * bits..
 589                 */
 590                case S_IFREG | 0664:
 591                        if (!options->strict)
 592                                break;
 593                        /* fallthrough */
 594                default:
 595                        has_bad_modes = 1;
 596                }
 597
 598                if (o_name) {
 599                        switch (verify_ordered(o_mode, o_name, mode, name)) {
 600                        case TREE_UNORDERED:
 601                                not_properly_sorted = 1;
 602                                break;
 603                        case TREE_HAS_DUPS:
 604                                has_dup_entries = 1;
 605                                break;
 606                        default:
 607                                break;
 608                        }
 609                }
 610
 611                o_mode = mode;
 612                o_name = name;
 613        }
 614
 615        if (has_null_sha1)
 616                retval += report(options, &item->object, FSCK_MSG_NULL_SHA1, "contains entries pointing to null sha1");
 617        if (has_full_path)
 618                retval += report(options, &item->object, FSCK_MSG_FULL_PATHNAME, "contains full pathnames");
 619        if (has_empty_name)
 620                retval += report(options, &item->object, FSCK_MSG_EMPTY_NAME, "contains empty pathname");
 621        if (has_dot)
 622                retval += report(options, &item->object, FSCK_MSG_HAS_DOT, "contains '.'");
 623        if (has_dotdot)
 624                retval += report(options, &item->object, FSCK_MSG_HAS_DOTDOT, "contains '..'");
 625        if (has_dotgit)
 626                retval += report(options, &item->object, FSCK_MSG_HAS_DOTGIT, "contains '.git'");
 627        if (has_zero_pad)
 628                retval += report(options, &item->object, FSCK_MSG_ZERO_PADDED_FILEMODE, "contains zero-padded file modes");
 629        if (has_bad_modes)
 630                retval += report(options, &item->object, FSCK_MSG_BAD_FILEMODE, "contains bad file modes");
 631        if (has_dup_entries)
 632                retval += report(options, &item->object, FSCK_MSG_DUPLICATE_ENTRIES, "contains duplicate file entries");
 633        if (not_properly_sorted)
 634                retval += report(options, &item->object, FSCK_MSG_TREE_NOT_SORTED, "not properly sorted");
 635        return retval;
 636}
 637
 638static int verify_headers(const void *data, unsigned long size,
 639                          struct object *obj, struct fsck_options *options)
 640{
 641        const char *buffer = (const char *)data;
 642        unsigned long i;
 643
 644        for (i = 0; i < size; i++) {
 645                switch (buffer[i]) {
 646                case '\0':
 647                        return report(options, obj,
 648                                FSCK_MSG_NUL_IN_HEADER,
 649                                "unterminated header: NUL at offset %ld", i);
 650                case '\n':
 651                        if (i + 1 < size && buffer[i + 1] == '\n')
 652                                return 0;
 653                }
 654        }
 655
 656        /*
 657         * We did not find double-LF that separates the header
 658         * and the body.  Not having a body is not a crime but
 659         * we do want to see the terminating LF for the last header
 660         * line.
 661         */
 662        if (size && buffer[size - 1] == '\n')
 663                return 0;
 664
 665        return report(options, obj,
 666                FSCK_MSG_UNTERMINATED_HEADER, "unterminated header");
 667}
 668
 669static int fsck_ident(const char **ident, struct object *obj, struct fsck_options *options)
 670{
 671        const char *p = *ident;
 672        char *end;
 673
 674        *ident = strchrnul(*ident, '\n');
 675        if (**ident == '\n')
 676                (*ident)++;
 677
 678        if (*p == '<')
 679                return report(options, obj, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 680        p += strcspn(p, "<>\n");
 681        if (*p == '>')
 682                return report(options, obj, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
 683        if (*p != '<')
 684                return report(options, obj, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
 685        if (p[-1] != ' ')
 686                return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 687        p++;
 688        p += strcspn(p, "<>\n");
 689        if (*p != '>')
 690                return report(options, obj, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
 691        p++;
 692        if (*p != ' ')
 693                return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
 694        p++;
 695        if (*p == '0' && p[1] != ' ')
 696                return report(options, obj, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
 697        if (date_overflows(parse_timestamp(p, &end, 10)))
 698                return report(options, obj, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
 699        if ((end == p || *end != ' '))
 700                return report(options, obj, FSCK_MSG_BAD_DATE, "invalid author/committer line - bad date");
 701        p = end + 1;
 702        if ((*p != '+' && *p != '-') ||
 703            !isdigit(p[1]) ||
 704            !isdigit(p[2]) ||
 705            !isdigit(p[3]) ||
 706            !isdigit(p[4]) ||
 707            (p[5] != '\n'))
 708                return report(options, obj, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
 709        p += 6;
 710        return 0;
 711}
 712
 713static int fsck_commit_buffer(struct commit *commit, const char *buffer,
 714        unsigned long size, struct fsck_options *options)
 715{
 716        unsigned char tree_sha1[20], sha1[20];
 717        struct commit_graft *graft;
 718        unsigned parent_count, parent_line_count = 0, author_count;
 719        int err;
 720        const char *buffer_begin = buffer;
 721
 722        if (verify_headers(buffer, size, &commit->object, options))
 723                return -1;
 724
 725        if (!skip_prefix(buffer, "tree ", &buffer))
 726                return report(options, &commit->object, FSCK_MSG_MISSING_TREE, "invalid format - expected 'tree' line");
 727        if (get_sha1_hex(buffer, tree_sha1) || buffer[40] != '\n') {
 728                err = report(options, &commit->object, FSCK_MSG_BAD_TREE_SHA1, "invalid 'tree' line format - bad sha1");
 729                if (err)
 730                        return err;
 731        }
 732        buffer += 41;
 733        while (skip_prefix(buffer, "parent ", &buffer)) {
 734                if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n') {
 735                        err = report(options, &commit->object, FSCK_MSG_BAD_PARENT_SHA1, "invalid 'parent' line format - bad sha1");
 736                        if (err)
 737                                return err;
 738                }
 739                buffer += 41;
 740                parent_line_count++;
 741        }
 742        graft = lookup_commit_graft(&commit->object.oid);
 743        parent_count = commit_list_count(commit->parents);
 744        if (graft) {
 745                if (graft->nr_parent == -1 && !parent_count)
 746                        ; /* shallow commit */
 747                else if (graft->nr_parent != parent_count) {
 748                        err = report(options, &commit->object, FSCK_MSG_MISSING_GRAFT, "graft objects missing");
 749                        if (err)
 750                                return err;
 751                }
 752        } else {
 753                if (parent_count != parent_line_count) {
 754                        err = report(options, &commit->object, FSCK_MSG_MISSING_PARENT, "parent objects missing");
 755                        if (err)
 756                                return err;
 757                }
 758        }
 759        author_count = 0;
 760        while (skip_prefix(buffer, "author ", &buffer)) {
 761                author_count++;
 762                err = fsck_ident(&buffer, &commit->object, options);
 763                if (err)
 764                        return err;
 765        }
 766        if (author_count < 1)
 767                err = report(options, &commit->object, FSCK_MSG_MISSING_AUTHOR, "invalid format - expected 'author' line");
 768        else if (author_count > 1)
 769                err = report(options, &commit->object, FSCK_MSG_MULTIPLE_AUTHORS, "invalid format - multiple 'author' lines");
 770        if (err)
 771                return err;
 772        if (!skip_prefix(buffer, "committer ", &buffer))
 773                return report(options, &commit->object, FSCK_MSG_MISSING_COMMITTER, "invalid format - expected 'committer' line");
 774        err = fsck_ident(&buffer, &commit->object, options);
 775        if (err)
 776                return err;
 777        if (!get_commit_tree(commit)) {
 778                err = report(options, &commit->object, FSCK_MSG_BAD_TREE, "could not load commit's tree %s", sha1_to_hex(tree_sha1));
 779                if (err)
 780                        return err;
 781        }
 782        if (memchr(buffer_begin, '\0', size)) {
 783                err = report(options, &commit->object, FSCK_MSG_NUL_IN_COMMIT,
 784                             "NUL byte in the commit object body");
 785                if (err)
 786                        return err;
 787        }
 788        return 0;
 789}
 790
 791static int fsck_commit(struct commit *commit, const char *data,
 792        unsigned long size, struct fsck_options *options)
 793{
 794        const char *buffer = data ?  data : get_commit_buffer(commit, &size);
 795        int ret = fsck_commit_buffer(commit, buffer, size, options);
 796        if (!data)
 797                unuse_commit_buffer(commit, buffer);
 798        return ret;
 799}
 800
 801static int fsck_tag_buffer(struct tag *tag, const char *data,
 802        unsigned long size, struct fsck_options *options)
 803{
 804        unsigned char sha1[20];
 805        int ret = 0;
 806        const char *buffer;
 807        char *to_free = NULL, *eol;
 808        struct strbuf sb = STRBUF_INIT;
 809
 810        if (data)
 811                buffer = data;
 812        else {
 813                enum object_type type;
 814
 815                buffer = to_free =
 816                        read_object_file(&tag->object.oid, &type, &size);
 817                if (!buffer)
 818                        return report(options, &tag->object,
 819                                FSCK_MSG_MISSING_TAG_OBJECT,
 820                                "cannot read tag object");
 821
 822                if (type != OBJ_TAG) {
 823                        ret = report(options, &tag->object,
 824                                FSCK_MSG_TAG_OBJECT_NOT_TAG,
 825                                "expected tag got %s",
 826                            type_name(type));
 827                        goto done;
 828                }
 829        }
 830
 831        ret = verify_headers(buffer, size, &tag->object, options);
 832        if (ret)
 833                goto done;
 834
 835        if (!skip_prefix(buffer, "object ", &buffer)) {
 836                ret = report(options, &tag->object, FSCK_MSG_MISSING_OBJECT, "invalid format - expected 'object' line");
 837                goto done;
 838        }
 839        if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n') {
 840                ret = report(options, &tag->object, FSCK_MSG_BAD_OBJECT_SHA1, "invalid 'object' line format - bad sha1");
 841                if (ret)
 842                        goto done;
 843        }
 844        buffer += 41;
 845
 846        if (!skip_prefix(buffer, "type ", &buffer)) {
 847                ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE_ENTRY, "invalid format - expected 'type' line");
 848                goto done;
 849        }
 850        eol = strchr(buffer, '\n');
 851        if (!eol) {
 852                ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE, "invalid format - unexpected end after 'type' line");
 853                goto done;
 854        }
 855        if (type_from_string_gently(buffer, eol - buffer, 1) < 0)
 856                ret = report(options, &tag->object, FSCK_MSG_BAD_TYPE, "invalid 'type' value");
 857        if (ret)
 858                goto done;
 859        buffer = eol + 1;
 860
 861        if (!skip_prefix(buffer, "tag ", &buffer)) {
 862                ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG_ENTRY, "invalid format - expected 'tag' line");
 863                goto done;
 864        }
 865        eol = strchr(buffer, '\n');
 866        if (!eol) {
 867                ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG, "invalid format - unexpected end after 'type' line");
 868                goto done;
 869        }
 870        strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer);
 871        if (check_refname_format(sb.buf, 0)) {
 872                ret = report(options, &tag->object, FSCK_MSG_BAD_TAG_NAME,
 873                           "invalid 'tag' name: %.*s",
 874                           (int)(eol - buffer), buffer);
 875                if (ret)
 876                        goto done;
 877        }
 878        buffer = eol + 1;
 879
 880        if (!skip_prefix(buffer, "tagger ", &buffer)) {
 881                /* early tags do not contain 'tagger' lines; warn only */
 882                ret = report(options, &tag->object, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
 883                if (ret)
 884                        goto done;
 885        }
 886        else
 887                ret = fsck_ident(&buffer, &tag->object, options);
 888
 889done:
 890        strbuf_release(&sb);
 891        free(to_free);
 892        return ret;
 893}
 894
 895static int fsck_tag(struct tag *tag, const char *data,
 896        unsigned long size, struct fsck_options *options)
 897{
 898        struct object *tagged = tag->tagged;
 899
 900        if (!tagged)
 901                return report(options, &tag->object, FSCK_MSG_BAD_TAG_OBJECT, "could not load tagged object");
 902
 903        return fsck_tag_buffer(tag, data, size, options);
 904}
 905
 906int fsck_object(struct object *obj, void *data, unsigned long size,
 907        struct fsck_options *options)
 908{
 909        if (!obj)
 910                return report(options, obj, FSCK_MSG_BAD_OBJECT_SHA1, "no valid object to fsck");
 911
 912        if (obj->type == OBJ_BLOB)
 913                return 0;
 914        if (obj->type == OBJ_TREE)
 915                return fsck_tree((struct tree *) obj, options);
 916        if (obj->type == OBJ_COMMIT)
 917                return fsck_commit((struct commit *) obj, (const char *) data,
 918                        size, options);
 919        if (obj->type == OBJ_TAG)
 920                return fsck_tag((struct tag *) obj, (const char *) data,
 921                        size, options);
 922
 923        return report(options, obj, FSCK_MSG_UNKNOWN_TYPE, "unknown type '%d' (internal fsck error)",
 924                          obj->type);
 925}
 926
 927int fsck_error_function(struct fsck_options *o,
 928        struct object *obj, int msg_type, const char *message)
 929{
 930        if (msg_type == FSCK_WARN) {
 931                warning("object %s: %s", describe_object(o, obj), message);
 932                return 0;
 933        }
 934        error("object %s: %s", describe_object(o, obj), message);
 935        return 1;
 936}