Merge branch 'bw/server-options'
[git] / fsck.c
1 #include "cache.h"
2 #include "object.h"
3 #include "blob.h"
4 #include "tree.h"
5 #include "tree-walk.h"
6 #include "commit.h"
7 #include "tag.h"
8 #include "fsck.h"
9 #include "refs.h"
10 #include "utf8.h"
11 #include "sha1-array.h"
12 #include "decorate.h"
13
14 #define FSCK_FATAL -1
15 #define FSCK_INFO -2
16
17 #define FOREACH_MSG_ID(FUNC) \
18         /* fatal errors */ \
19         FUNC(NUL_IN_HEADER, FATAL) \
20         FUNC(UNTERMINATED_HEADER, FATAL) \
21         /* errors */ \
22         FUNC(BAD_DATE, ERROR) \
23         FUNC(BAD_DATE_OVERFLOW, ERROR) \
24         FUNC(BAD_EMAIL, ERROR) \
25         FUNC(BAD_NAME, ERROR) \
26         FUNC(BAD_OBJECT_SHA1, ERROR) \
27         FUNC(BAD_PARENT_SHA1, ERROR) \
28         FUNC(BAD_TAG_OBJECT, ERROR) \
29         FUNC(BAD_TIMEZONE, ERROR) \
30         FUNC(BAD_TREE, ERROR) \
31         FUNC(BAD_TREE_SHA1, ERROR) \
32         FUNC(BAD_TYPE, ERROR) \
33         FUNC(DUPLICATE_ENTRIES, ERROR) \
34         FUNC(MISSING_AUTHOR, ERROR) \
35         FUNC(MISSING_COMMITTER, ERROR) \
36         FUNC(MISSING_EMAIL, ERROR) \
37         FUNC(MISSING_GRAFT, ERROR) \
38         FUNC(MISSING_NAME_BEFORE_EMAIL, ERROR) \
39         FUNC(MISSING_OBJECT, ERROR) \
40         FUNC(MISSING_PARENT, ERROR) \
41         FUNC(MISSING_SPACE_BEFORE_DATE, ERROR) \
42         FUNC(MISSING_SPACE_BEFORE_EMAIL, ERROR) \
43         FUNC(MISSING_TAG, ERROR) \
44         FUNC(MISSING_TAG_ENTRY, ERROR) \
45         FUNC(MISSING_TAG_OBJECT, ERROR) \
46         FUNC(MISSING_TREE, ERROR) \
47         FUNC(MISSING_TYPE, ERROR) \
48         FUNC(MISSING_TYPE_ENTRY, ERROR) \
49         FUNC(MULTIPLE_AUTHORS, ERROR) \
50         FUNC(TAG_OBJECT_NOT_TAG, ERROR) \
51         FUNC(TREE_NOT_SORTED, ERROR) \
52         FUNC(UNKNOWN_TYPE, ERROR) \
53         FUNC(ZERO_PADDED_DATE, ERROR) \
54         /* warnings */ \
55         FUNC(BAD_FILEMODE, WARN) \
56         FUNC(EMPTY_NAME, WARN) \
57         FUNC(FULL_PATHNAME, WARN) \
58         FUNC(HAS_DOT, WARN) \
59         FUNC(HAS_DOTDOT, WARN) \
60         FUNC(HAS_DOTGIT, WARN) \
61         FUNC(NULL_SHA1, WARN) \
62         FUNC(ZERO_PADDED_FILEMODE, WARN) \
63         FUNC(NUL_IN_COMMIT, WARN) \
64         /* infos (reported as warnings, but ignored by default) */ \
65         FUNC(BAD_TAG_NAME, INFO) \
66         FUNC(MISSING_TAGGER_ENTRY, INFO)
67
68 #define MSG_ID(id, msg_type) FSCK_MSG_##id,
69 enum fsck_msg_id {
70         FOREACH_MSG_ID(MSG_ID)
71         FSCK_MSG_MAX
72 };
73 #undef MSG_ID
74
75 #define STR(x) #x
76 #define MSG_ID(id, msg_type) { STR(id), NULL, FSCK_##msg_type },
77 static struct {
78         const char *id_string;
79         const char *downcased;
80         int msg_type;
81 } msg_id_info[FSCK_MSG_MAX + 1] = {
82         FOREACH_MSG_ID(MSG_ID)
83         { NULL, NULL, -1 }
84 };
85 #undef MSG_ID
86
87 static int parse_msg_id(const char *text)
88 {
89         int i;
90
91         if (!msg_id_info[0].downcased) {
92                 /* convert id_string to lower case, without underscores. */
93                 for (i = 0; i < FSCK_MSG_MAX; i++) {
94                         const char *p = msg_id_info[i].id_string;
95                         int len = strlen(p);
96                         char *q = xmalloc(len);
97
98                         msg_id_info[i].downcased = q;
99                         while (*p)
100                                 if (*p == '_')
101                                         p++;
102                                 else
103                                         *(q)++ = tolower(*(p)++);
104                         *q = '\0';
105                 }
106         }
107
108         for (i = 0; i < FSCK_MSG_MAX; i++)
109                 if (!strcmp(text, msg_id_info[i].downcased))
110                         return i;
111
112         return -1;
113 }
114
115 static int fsck_msg_type(enum fsck_msg_id msg_id,
116         struct fsck_options *options)
117 {
118         int msg_type;
119
120         assert(msg_id >= 0 && msg_id < FSCK_MSG_MAX);
121
122         if (options->msg_type)
123                 msg_type = options->msg_type[msg_id];
124         else {
125                 msg_type = msg_id_info[msg_id].msg_type;
126                 if (options->strict && msg_type == FSCK_WARN)
127                         msg_type = FSCK_ERROR;
128         }
129
130         return msg_type;
131 }
132
133 static void init_skiplist(struct fsck_options *options, const char *path)
134 {
135         static struct 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
171 static 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
183 int 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
191 void 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
215 void 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
253 static 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)))
272 static 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
302 static 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
309 static 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
327 static 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
340 static 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
386 static 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
449 static 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
460 int 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
494 static 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
529 static 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
638 static 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
669 static 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
713 static 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
791 static 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
801 static 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
889 done:
890         strbuf_release(&sb);
891         free(to_free);
892         return ret;
893 }
894
895 static 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
906 int 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
927 int 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 }