config: add options parameter to git_config_from_mem
[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 #include "oidset.h"
14 #include "packfile.h"
15 #include "submodule-config.h"
16 #include "config.h"
17 #include "help.h"
18
19 static struct oidset gitmodules_found = OIDSET_INIT;
20 static struct oidset gitmodules_done = OIDSET_INIT;
21
22 #define FSCK_FATAL -1
23 #define FSCK_INFO -2
24
25 #define FOREACH_MSG_ID(FUNC) \
26         /* fatal errors */ \
27         FUNC(NUL_IN_HEADER, FATAL) \
28         FUNC(UNTERMINATED_HEADER, FATAL) \
29         /* errors */ \
30         FUNC(BAD_DATE, ERROR) \
31         FUNC(BAD_DATE_OVERFLOW, ERROR) \
32         FUNC(BAD_EMAIL, ERROR) \
33         FUNC(BAD_NAME, ERROR) \
34         FUNC(BAD_OBJECT_SHA1, ERROR) \
35         FUNC(BAD_PARENT_SHA1, ERROR) \
36         FUNC(BAD_TAG_OBJECT, ERROR) \
37         FUNC(BAD_TIMEZONE, ERROR) \
38         FUNC(BAD_TREE, ERROR) \
39         FUNC(BAD_TREE_SHA1, ERROR) \
40         FUNC(BAD_TYPE, ERROR) \
41         FUNC(DUPLICATE_ENTRIES, ERROR) \
42         FUNC(MISSING_AUTHOR, ERROR) \
43         FUNC(MISSING_COMMITTER, ERROR) \
44         FUNC(MISSING_EMAIL, ERROR) \
45         FUNC(MISSING_GRAFT, ERROR) \
46         FUNC(MISSING_NAME_BEFORE_EMAIL, ERROR) \
47         FUNC(MISSING_OBJECT, ERROR) \
48         FUNC(MISSING_PARENT, ERROR) \
49         FUNC(MISSING_SPACE_BEFORE_DATE, ERROR) \
50         FUNC(MISSING_SPACE_BEFORE_EMAIL, ERROR) \
51         FUNC(MISSING_TAG, ERROR) \
52         FUNC(MISSING_TAG_ENTRY, ERROR) \
53         FUNC(MISSING_TAG_OBJECT, ERROR) \
54         FUNC(MISSING_TREE, ERROR) \
55         FUNC(MISSING_TREE_OBJECT, ERROR) \
56         FUNC(MISSING_TYPE, ERROR) \
57         FUNC(MISSING_TYPE_ENTRY, ERROR) \
58         FUNC(MULTIPLE_AUTHORS, ERROR) \
59         FUNC(TAG_OBJECT_NOT_TAG, ERROR) \
60         FUNC(TREE_NOT_SORTED, ERROR) \
61         FUNC(UNKNOWN_TYPE, ERROR) \
62         FUNC(ZERO_PADDED_DATE, ERROR) \
63         FUNC(GITMODULES_MISSING, ERROR) \
64         FUNC(GITMODULES_BLOB, ERROR) \
65         FUNC(GITMODULES_PARSE, ERROR) \
66         FUNC(GITMODULES_NAME, ERROR) \
67         FUNC(GITMODULES_SYMLINK, ERROR) \
68         /* warnings */ \
69         FUNC(BAD_FILEMODE, WARN) \
70         FUNC(EMPTY_NAME, WARN) \
71         FUNC(FULL_PATHNAME, WARN) \
72         FUNC(HAS_DOT, WARN) \
73         FUNC(HAS_DOTDOT, WARN) \
74         FUNC(HAS_DOTGIT, WARN) \
75         FUNC(NULL_SHA1, WARN) \
76         FUNC(ZERO_PADDED_FILEMODE, WARN) \
77         FUNC(NUL_IN_COMMIT, WARN) \
78         /* infos (reported as warnings, but ignored by default) */ \
79         FUNC(BAD_TAG_NAME, INFO) \
80         FUNC(MISSING_TAGGER_ENTRY, INFO)
81
82 #define MSG_ID(id, msg_type) FSCK_MSG_##id,
83 enum fsck_msg_id {
84         FOREACH_MSG_ID(MSG_ID)
85         FSCK_MSG_MAX
86 };
87 #undef MSG_ID
88
89 #define STR(x) #x
90 #define MSG_ID(id, msg_type) { STR(id), NULL, NULL, FSCK_##msg_type },
91 static struct {
92         const char *id_string;
93         const char *downcased;
94         const char *camelcased;
95         int msg_type;
96 } msg_id_info[FSCK_MSG_MAX + 1] = {
97         FOREACH_MSG_ID(MSG_ID)
98         { NULL, NULL, NULL, -1 }
99 };
100 #undef MSG_ID
101
102 static void prepare_msg_ids(void)
103 {
104         int i;
105
106         if (msg_id_info[0].downcased)
107                 return;
108
109         /* convert id_string to lower case, without underscores. */
110         for (i = 0; i < FSCK_MSG_MAX; i++) {
111                 const char *p = msg_id_info[i].id_string;
112                 int len = strlen(p);
113                 char *q = xmalloc(len);
114
115                 msg_id_info[i].downcased = q;
116                 while (*p)
117                         if (*p == '_')
118                                 p++;
119                         else
120                                 *(q)++ = tolower(*(p)++);
121                 *q = '\0';
122
123                 p = msg_id_info[i].id_string;
124                 q = xmalloc(len);
125                 msg_id_info[i].camelcased = q;
126                 while (*p) {
127                         if (*p == '_') {
128                                 p++;
129                                 if (*p)
130                                         *q++ = *p++;
131                         } else {
132                                 *q++ = tolower(*p++);
133                         }
134                 }
135                 *q = '\0';
136         }
137 }
138
139 static int parse_msg_id(const char *text)
140 {
141         int i;
142
143         prepare_msg_ids();
144
145         for (i = 0; i < FSCK_MSG_MAX; i++)
146                 if (!strcmp(text, msg_id_info[i].downcased))
147                         return i;
148
149         return -1;
150 }
151
152 void list_config_fsck_msg_ids(struct string_list *list, const char *prefix)
153 {
154         int i;
155
156         prepare_msg_ids();
157
158         for (i = 0; i < FSCK_MSG_MAX; i++)
159                 list_config_item(list, prefix, msg_id_info[i].camelcased);
160 }
161
162 static int fsck_msg_type(enum fsck_msg_id msg_id,
163         struct fsck_options *options)
164 {
165         int msg_type;
166
167         assert(msg_id >= 0 && msg_id < FSCK_MSG_MAX);
168
169         if (options->msg_type)
170                 msg_type = options->msg_type[msg_id];
171         else {
172                 msg_type = msg_id_info[msg_id].msg_type;
173                 if (options->strict && msg_type == FSCK_WARN)
174                         msg_type = FSCK_ERROR;
175         }
176
177         return msg_type;
178 }
179
180 static void init_skiplist(struct fsck_options *options, const char *path)
181 {
182         static struct oid_array skiplist = OID_ARRAY_INIT;
183         int sorted, fd;
184         char buffer[GIT_MAX_HEXSZ + 1];
185         struct object_id oid;
186
187         if (options->skiplist)
188                 sorted = options->skiplist->sorted;
189         else {
190                 sorted = 1;
191                 options->skiplist = &skiplist;
192         }
193
194         fd = open(path, O_RDONLY);
195         if (fd < 0)
196                 die("Could not open skip list: %s", path);
197         for (;;) {
198                 const char *p;
199                 int result = read_in_full(fd, buffer, sizeof(buffer));
200                 if (result < 0)
201                         die_errno("Could not read '%s'", path);
202                 if (!result)
203                         break;
204                 if (parse_oid_hex(buffer, &oid, &p) || *p != '\n')
205                         die("Invalid SHA-1: %s", buffer);
206                 oid_array_append(&skiplist, &oid);
207                 if (sorted && skiplist.nr > 1 &&
208                                 oidcmp(&skiplist.oid[skiplist.nr - 2],
209                                        &oid) > 0)
210                         sorted = 0;
211         }
212         close(fd);
213
214         if (sorted)
215                 skiplist.sorted = 1;
216 }
217
218 static int parse_msg_type(const char *str)
219 {
220         if (!strcmp(str, "error"))
221                 return FSCK_ERROR;
222         else if (!strcmp(str, "warn"))
223                 return FSCK_WARN;
224         else if (!strcmp(str, "ignore"))
225                 return FSCK_IGNORE;
226         else
227                 die("Unknown fsck message type: '%s'", str);
228 }
229
230 int is_valid_msg_type(const char *msg_id, const char *msg_type)
231 {
232         if (parse_msg_id(msg_id) < 0)
233                 return 0;
234         parse_msg_type(msg_type);
235         return 1;
236 }
237
238 void fsck_set_msg_type(struct fsck_options *options,
239                 const char *msg_id, const char *msg_type)
240 {
241         int id = parse_msg_id(msg_id), type;
242
243         if (id < 0)
244                 die("Unhandled message id: %s", msg_id);
245         type = parse_msg_type(msg_type);
246
247         if (type != FSCK_ERROR && msg_id_info[id].msg_type == FSCK_FATAL)
248                 die("Cannot demote %s to %s", msg_id, msg_type);
249
250         if (!options->msg_type) {
251                 int i;
252                 int *msg_type;
253                 ALLOC_ARRAY(msg_type, FSCK_MSG_MAX);
254                 for (i = 0; i < FSCK_MSG_MAX; i++)
255                         msg_type[i] = fsck_msg_type(i, options);
256                 options->msg_type = msg_type;
257         }
258
259         options->msg_type[id] = type;
260 }
261
262 void fsck_set_msg_types(struct fsck_options *options, const char *values)
263 {
264         char *buf = xstrdup(values), *to_free = buf;
265         int done = 0;
266
267         while (!done) {
268                 int len = strcspn(buf, " ,|"), equal;
269
270                 done = !buf[len];
271                 if (!len) {
272                         buf++;
273                         continue;
274                 }
275                 buf[len] = '\0';
276
277                 for (equal = 0;
278                      equal < len && buf[equal] != '=' && buf[equal] != ':';
279                      equal++)
280                         buf[equal] = tolower(buf[equal]);
281                 buf[equal] = '\0';
282
283                 if (!strcmp(buf, "skiplist")) {
284                         if (equal == len)
285                                 die("skiplist requires a path");
286                         init_skiplist(options, buf + equal + 1);
287                         buf += len + 1;
288                         continue;
289                 }
290
291                 if (equal == len)
292                         die("Missing '=': '%s'", buf);
293
294                 fsck_set_msg_type(options, buf, buf + equal + 1);
295                 buf += len + 1;
296         }
297         free(to_free);
298 }
299
300 static void append_msg_id(struct strbuf *sb, const char *msg_id)
301 {
302         for (;;) {
303                 char c = *(msg_id)++;
304
305                 if (!c)
306                         break;
307                 if (c != '_')
308                         strbuf_addch(sb, tolower(c));
309                 else {
310                         assert(*msg_id);
311                         strbuf_addch(sb, *(msg_id)++);
312                 }
313         }
314
315         strbuf_addstr(sb, ": ");
316 }
317
318 __attribute__((format (printf, 4, 5)))
319 static int report(struct fsck_options *options, struct object *object,
320         enum fsck_msg_id id, const char *fmt, ...)
321 {
322         va_list ap;
323         struct strbuf sb = STRBUF_INIT;
324         int msg_type = fsck_msg_type(id, options), result;
325
326         if (msg_type == FSCK_IGNORE)
327                 return 0;
328
329         if (options->skiplist && object &&
330                         oid_array_lookup(options->skiplist, &object->oid) >= 0)
331                 return 0;
332
333         if (msg_type == FSCK_FATAL)
334                 msg_type = FSCK_ERROR;
335         else if (msg_type == FSCK_INFO)
336                 msg_type = FSCK_WARN;
337
338         append_msg_id(&sb, msg_id_info[id].id_string);
339
340         va_start(ap, fmt);
341         strbuf_vaddf(&sb, fmt, ap);
342         result = options->error_func(options, object, msg_type, sb.buf);
343         strbuf_release(&sb);
344         va_end(ap);
345
346         return result;
347 }
348
349 static char *get_object_name(struct fsck_options *options, struct object *obj)
350 {
351         if (!options->object_names)
352                 return NULL;
353         return lookup_decoration(options->object_names, obj);
354 }
355
356 static void put_object_name(struct fsck_options *options, struct object *obj,
357         const char *fmt, ...)
358 {
359         va_list ap;
360         struct strbuf buf = STRBUF_INIT;
361         char *existing;
362
363         if (!options->object_names)
364                 return;
365         existing = lookup_decoration(options->object_names, obj);
366         if (existing)
367                 return;
368         va_start(ap, fmt);
369         strbuf_vaddf(&buf, fmt, ap);
370         add_decoration(options->object_names, obj, strbuf_detach(&buf, NULL));
371         va_end(ap);
372 }
373
374 static const char *describe_object(struct fsck_options *o, struct object *obj)
375 {
376         static struct strbuf buf = STRBUF_INIT;
377         char *name;
378
379         strbuf_reset(&buf);
380         strbuf_addstr(&buf, oid_to_hex(&obj->oid));
381         if (o->object_names && (name = lookup_decoration(o->object_names, obj)))
382                 strbuf_addf(&buf, " (%s)", name);
383
384         return buf.buf;
385 }
386
387 static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *options)
388 {
389         struct tree_desc desc;
390         struct name_entry entry;
391         int res = 0;
392         const char *name;
393
394         if (parse_tree(tree))
395                 return -1;
396
397         name = get_object_name(options, &tree->object);
398         if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
399                 return -1;
400         while (tree_entry_gently(&desc, &entry)) {
401                 struct object *obj;
402                 int result;
403
404                 if (S_ISGITLINK(entry.mode))
405                         continue;
406
407                 if (S_ISDIR(entry.mode)) {
408                         obj = (struct object *)lookup_tree(entry.oid);
409                         if (name && obj)
410                                 put_object_name(options, obj, "%s%s/", name,
411                                         entry.path);
412                         result = options->walk(obj, OBJ_TREE, data, options);
413                 }
414                 else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode)) {
415                         obj = (struct object *)lookup_blob(entry.oid);
416                         if (name && obj)
417                                 put_object_name(options, obj, "%s%s", name,
418                                         entry.path);
419                         result = options->walk(obj, OBJ_BLOB, data, options);
420                 }
421                 else {
422                         result = error("in tree %s: entry %s has bad mode %.6o",
423                                         describe_object(options, &tree->object), entry.path, entry.mode);
424                 }
425                 if (result < 0)
426                         return result;
427                 if (!res)
428                         res = result;
429         }
430         return res;
431 }
432
433 static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_options *options)
434 {
435         int counter = 0, generation = 0, name_prefix_len = 0;
436         struct commit_list *parents;
437         int res;
438         int result;
439         const char *name;
440
441         if (parse_commit(commit))
442                 return -1;
443
444         name = get_object_name(options, &commit->object);
445         if (name)
446                 put_object_name(options, &get_commit_tree(commit)->object,
447                                 "%s:", name);
448
449         result = options->walk((struct object *)get_commit_tree(commit),
450                                OBJ_TREE, data, options);
451         if (result < 0)
452                 return result;
453         res = result;
454
455         parents = commit->parents;
456         if (name && parents) {
457                 int len = strlen(name), power;
458
459                 if (len && name[len - 1] == '^') {
460                         generation = 1;
461                         name_prefix_len = len - 1;
462                 }
463                 else { /* parse ~<generation> suffix */
464                         for (generation = 0, power = 1;
465                              len && isdigit(name[len - 1]);
466                              power *= 10)
467                                 generation += power * (name[--len] - '0');
468                         if (power > 1 && len && name[len - 1] == '~')
469                                 name_prefix_len = len - 1;
470                 }
471         }
472
473         while (parents) {
474                 if (name) {
475                         struct object *obj = &parents->item->object;
476
477                         if (++counter > 1)
478                                 put_object_name(options, obj, "%s^%d",
479                                         name, counter);
480                         else if (generation > 0)
481                                 put_object_name(options, obj, "%.*s~%d",
482                                         name_prefix_len, name, generation + 1);
483                         else
484                                 put_object_name(options, obj, "%s^", name);
485                 }
486                 result = options->walk((struct object *)parents->item, OBJ_COMMIT, data, options);
487                 if (result < 0)
488                         return result;
489                 if (!res)
490                         res = result;
491                 parents = parents->next;
492         }
493         return res;
494 }
495
496 static int fsck_walk_tag(struct tag *tag, void *data, struct fsck_options *options)
497 {
498         char *name = get_object_name(options, &tag->object);
499
500         if (parse_tag(tag))
501                 return -1;
502         if (name)
503                 put_object_name(options, tag->tagged, "%s", name);
504         return options->walk(tag->tagged, OBJ_ANY, data, options);
505 }
506
507 int fsck_walk(struct object *obj, void *data, struct fsck_options *options)
508 {
509         if (!obj)
510                 return -1;
511
512         if (obj->type == OBJ_NONE)
513                 parse_object(&obj->oid);
514
515         switch (obj->type) {
516         case OBJ_BLOB:
517                 return 0;
518         case OBJ_TREE:
519                 return fsck_walk_tree((struct tree *)obj, data, options);
520         case OBJ_COMMIT:
521                 return fsck_walk_commit((struct commit *)obj, data, options);
522         case OBJ_TAG:
523                 return fsck_walk_tag((struct tag *)obj, data, options);
524         default:
525                 error("Unknown object type for %s", describe_object(options, obj));
526                 return -1;
527         }
528 }
529
530 /*
531  * The entries in a tree are ordered in the _path_ order,
532  * which means that a directory entry is ordered by adding
533  * a slash to the end of it.
534  *
535  * So a directory called "a" is ordered _after_ a file
536  * called "a.c", because "a/" sorts after "a.c".
537  */
538 #define TREE_UNORDERED (-1)
539 #define TREE_HAS_DUPS  (-2)
540
541 static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
542 {
543         int len1 = strlen(name1);
544         int len2 = strlen(name2);
545         int len = len1 < len2 ? len1 : len2;
546         unsigned char c1, c2;
547         int cmp;
548
549         cmp = memcmp(name1, name2, len);
550         if (cmp < 0)
551                 return 0;
552         if (cmp > 0)
553                 return TREE_UNORDERED;
554
555         /*
556          * Ok, the first <len> characters are the same.
557          * Now we need to order the next one, but turn
558          * a '\0' into a '/' for a directory entry.
559          */
560         c1 = name1[len];
561         c2 = name2[len];
562         if (!c1 && !c2)
563                 /*
564                  * git-write-tree used to write out a nonsense tree that has
565                  * entries with the same name, one blob and one tree.  Make
566                  * sure we do not have duplicate entries.
567                  */
568                 return TREE_HAS_DUPS;
569         if (!c1 && S_ISDIR(mode1))
570                 c1 = '/';
571         if (!c2 && S_ISDIR(mode2))
572                 c2 = '/';
573         return c1 < c2 ? 0 : TREE_UNORDERED;
574 }
575
576 static int fsck_tree(struct tree *item, struct fsck_options *options)
577 {
578         int retval = 0;
579         int has_null_sha1 = 0;
580         int has_full_path = 0;
581         int has_empty_name = 0;
582         int has_dot = 0;
583         int has_dotdot = 0;
584         int has_dotgit = 0;
585         int has_zero_pad = 0;
586         int has_bad_modes = 0;
587         int has_dup_entries = 0;
588         int not_properly_sorted = 0;
589         struct tree_desc desc;
590         unsigned o_mode;
591         const char *o_name;
592
593         if (init_tree_desc_gently(&desc, item->buffer, item->size)) {
594                 retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
595                 return retval;
596         }
597
598         o_mode = 0;
599         o_name = NULL;
600
601         while (desc.size) {
602                 unsigned mode;
603                 const char *name;
604                 const struct object_id *oid;
605
606                 oid = tree_entry_extract(&desc, &name, &mode);
607
608                 has_null_sha1 |= is_null_oid(oid);
609                 has_full_path |= !!strchr(name, '/');
610                 has_empty_name |= !*name;
611                 has_dot |= !strcmp(name, ".");
612                 has_dotdot |= !strcmp(name, "..");
613                 has_dotgit |= is_hfs_dotgit(name) || is_ntfs_dotgit(name);
614                 has_zero_pad |= *(char *)desc.buffer == '0';
615
616                 if (is_hfs_dotgitmodules(name) || is_ntfs_dotgitmodules(name)) {
617                         if (!S_ISLNK(mode))
618                                 oidset_insert(&gitmodules_found, oid);
619                         else
620                                 retval += report(options, &item->object,
621                                                  FSCK_MSG_GITMODULES_SYMLINK,
622                                                  ".gitmodules is a symbolic link");
623                 }
624
625                 if (update_tree_entry_gently(&desc)) {
626                         retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
627                         break;
628                 }
629
630                 switch (mode) {
631                 /*
632                  * Standard modes..
633                  */
634                 case S_IFREG | 0755:
635                 case S_IFREG | 0644:
636                 case S_IFLNK:
637                 case S_IFDIR:
638                 case S_IFGITLINK:
639                         break;
640                 /*
641                  * This is nonstandard, but we had a few of these
642                  * early on when we honored the full set of mode
643                  * bits..
644                  */
645                 case S_IFREG | 0664:
646                         if (!options->strict)
647                                 break;
648                         /* fallthrough */
649                 default:
650                         has_bad_modes = 1;
651                 }
652
653                 if (o_name) {
654                         switch (verify_ordered(o_mode, o_name, mode, name)) {
655                         case TREE_UNORDERED:
656                                 not_properly_sorted = 1;
657                                 break;
658                         case TREE_HAS_DUPS:
659                                 has_dup_entries = 1;
660                                 break;
661                         default:
662                                 break;
663                         }
664                 }
665
666                 o_mode = mode;
667                 o_name = name;
668         }
669
670         if (has_null_sha1)
671                 retval += report(options, &item->object, FSCK_MSG_NULL_SHA1, "contains entries pointing to null sha1");
672         if (has_full_path)
673                 retval += report(options, &item->object, FSCK_MSG_FULL_PATHNAME, "contains full pathnames");
674         if (has_empty_name)
675                 retval += report(options, &item->object, FSCK_MSG_EMPTY_NAME, "contains empty pathname");
676         if (has_dot)
677                 retval += report(options, &item->object, FSCK_MSG_HAS_DOT, "contains '.'");
678         if (has_dotdot)
679                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTDOT, "contains '..'");
680         if (has_dotgit)
681                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTGIT, "contains '.git'");
682         if (has_zero_pad)
683                 retval += report(options, &item->object, FSCK_MSG_ZERO_PADDED_FILEMODE, "contains zero-padded file modes");
684         if (has_bad_modes)
685                 retval += report(options, &item->object, FSCK_MSG_BAD_FILEMODE, "contains bad file modes");
686         if (has_dup_entries)
687                 retval += report(options, &item->object, FSCK_MSG_DUPLICATE_ENTRIES, "contains duplicate file entries");
688         if (not_properly_sorted)
689                 retval += report(options, &item->object, FSCK_MSG_TREE_NOT_SORTED, "not properly sorted");
690         return retval;
691 }
692
693 static int verify_headers(const void *data, unsigned long size,
694                           struct object *obj, struct fsck_options *options)
695 {
696         const char *buffer = (const char *)data;
697         unsigned long i;
698
699         for (i = 0; i < size; i++) {
700                 switch (buffer[i]) {
701                 case '\0':
702                         return report(options, obj,
703                                 FSCK_MSG_NUL_IN_HEADER,
704                                 "unterminated header: NUL at offset %ld", i);
705                 case '\n':
706                         if (i + 1 < size && buffer[i + 1] == '\n')
707                                 return 0;
708                 }
709         }
710
711         /*
712          * We did not find double-LF that separates the header
713          * and the body.  Not having a body is not a crime but
714          * we do want to see the terminating LF for the last header
715          * line.
716          */
717         if (size && buffer[size - 1] == '\n')
718                 return 0;
719
720         return report(options, obj,
721                 FSCK_MSG_UNTERMINATED_HEADER, "unterminated header");
722 }
723
724 static int fsck_ident(const char **ident, struct object *obj, struct fsck_options *options)
725 {
726         const char *p = *ident;
727         char *end;
728
729         *ident = strchrnul(*ident, '\n');
730         if (**ident == '\n')
731                 (*ident)++;
732
733         if (*p == '<')
734                 return report(options, obj, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
735         p += strcspn(p, "<>\n");
736         if (*p == '>')
737                 return report(options, obj, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
738         if (*p != '<')
739                 return report(options, obj, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
740         if (p[-1] != ' ')
741                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
742         p++;
743         p += strcspn(p, "<>\n");
744         if (*p != '>')
745                 return report(options, obj, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
746         p++;
747         if (*p != ' ')
748                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
749         p++;
750         if (*p == '0' && p[1] != ' ')
751                 return report(options, obj, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
752         if (date_overflows(parse_timestamp(p, &end, 10)))
753                 return report(options, obj, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
754         if ((end == p || *end != ' '))
755                 return report(options, obj, FSCK_MSG_BAD_DATE, "invalid author/committer line - bad date");
756         p = end + 1;
757         if ((*p != '+' && *p != '-') ||
758             !isdigit(p[1]) ||
759             !isdigit(p[2]) ||
760             !isdigit(p[3]) ||
761             !isdigit(p[4]) ||
762             (p[5] != '\n'))
763                 return report(options, obj, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
764         p += 6;
765         return 0;
766 }
767
768 static int fsck_commit_buffer(struct commit *commit, const char *buffer,
769         unsigned long size, struct fsck_options *options)
770 {
771         struct object_id tree_oid, oid;
772         struct commit_graft *graft;
773         unsigned parent_count, parent_line_count = 0, author_count;
774         int err;
775         const char *buffer_begin = buffer;
776         const char *p;
777
778         if (verify_headers(buffer, size, &commit->object, options))
779                 return -1;
780
781         if (!skip_prefix(buffer, "tree ", &buffer))
782                 return report(options, &commit->object, FSCK_MSG_MISSING_TREE, "invalid format - expected 'tree' line");
783         if (parse_oid_hex(buffer, &tree_oid, &p) || *p != '\n') {
784                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE_SHA1, "invalid 'tree' line format - bad sha1");
785                 if (err)
786                         return err;
787         }
788         buffer = p + 1;
789         while (skip_prefix(buffer, "parent ", &buffer)) {
790                 if (parse_oid_hex(buffer, &oid, &p) || *p != '\n') {
791                         err = report(options, &commit->object, FSCK_MSG_BAD_PARENT_SHA1, "invalid 'parent' line format - bad sha1");
792                         if (err)
793                                 return err;
794                 }
795                 buffer = p + 1;
796                 parent_line_count++;
797         }
798         graft = lookup_commit_graft(&commit->object.oid);
799         parent_count = commit_list_count(commit->parents);
800         if (graft) {
801                 if (graft->nr_parent == -1 && !parent_count)
802                         ; /* shallow commit */
803                 else if (graft->nr_parent != parent_count) {
804                         err = report(options, &commit->object, FSCK_MSG_MISSING_GRAFT, "graft objects missing");
805                         if (err)
806                                 return err;
807                 }
808         } else {
809                 if (parent_count != parent_line_count) {
810                         err = report(options, &commit->object, FSCK_MSG_MISSING_PARENT, "parent objects missing");
811                         if (err)
812                                 return err;
813                 }
814         }
815         author_count = 0;
816         while (skip_prefix(buffer, "author ", &buffer)) {
817                 author_count++;
818                 err = fsck_ident(&buffer, &commit->object, options);
819                 if (err)
820                         return err;
821         }
822         if (author_count < 1)
823                 err = report(options, &commit->object, FSCK_MSG_MISSING_AUTHOR, "invalid format - expected 'author' line");
824         else if (author_count > 1)
825                 err = report(options, &commit->object, FSCK_MSG_MULTIPLE_AUTHORS, "invalid format - multiple 'author' lines");
826         if (err)
827                 return err;
828         if (!skip_prefix(buffer, "committer ", &buffer))
829                 return report(options, &commit->object, FSCK_MSG_MISSING_COMMITTER, "invalid format - expected 'committer' line");
830         err = fsck_ident(&buffer, &commit->object, options);
831         if (err)
832                 return err;
833         if (!get_commit_tree(commit)) {
834                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE, "could not load commit's tree %s", oid_to_hex(&tree_oid));
835                 if (err)
836                         return err;
837         }
838         if (memchr(buffer_begin, '\0', size)) {
839                 err = report(options, &commit->object, FSCK_MSG_NUL_IN_COMMIT,
840                              "NUL byte in the commit object body");
841                 if (err)
842                         return err;
843         }
844         return 0;
845 }
846
847 static int fsck_commit(struct commit *commit, const char *data,
848         unsigned long size, struct fsck_options *options)
849 {
850         const char *buffer = data ?  data : get_commit_buffer(commit, &size);
851         int ret = fsck_commit_buffer(commit, buffer, size, options);
852         if (!data)
853                 unuse_commit_buffer(commit, buffer);
854         return ret;
855 }
856
857 static int fsck_tag_buffer(struct tag *tag, const char *data,
858         unsigned long size, struct fsck_options *options)
859 {
860         struct object_id oid;
861         int ret = 0;
862         const char *buffer;
863         char *to_free = NULL, *eol;
864         struct strbuf sb = STRBUF_INIT;
865         const char *p;
866
867         if (data)
868                 buffer = data;
869         else {
870                 enum object_type type;
871
872                 buffer = to_free =
873                         read_object_file(&tag->object.oid, &type, &size);
874                 if (!buffer)
875                         return report(options, &tag->object,
876                                 FSCK_MSG_MISSING_TAG_OBJECT,
877                                 "cannot read tag object");
878
879                 if (type != OBJ_TAG) {
880                         ret = report(options, &tag->object,
881                                 FSCK_MSG_TAG_OBJECT_NOT_TAG,
882                                 "expected tag got %s",
883                             type_name(type));
884                         goto done;
885                 }
886         }
887
888         ret = verify_headers(buffer, size, &tag->object, options);
889         if (ret)
890                 goto done;
891
892         if (!skip_prefix(buffer, "object ", &buffer)) {
893                 ret = report(options, &tag->object, FSCK_MSG_MISSING_OBJECT, "invalid format - expected 'object' line");
894                 goto done;
895         }
896         if (parse_oid_hex(buffer, &oid, &p) || *p != '\n') {
897                 ret = report(options, &tag->object, FSCK_MSG_BAD_OBJECT_SHA1, "invalid 'object' line format - bad sha1");
898                 if (ret)
899                         goto done;
900         }
901         buffer = p + 1;
902
903         if (!skip_prefix(buffer, "type ", &buffer)) {
904                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE_ENTRY, "invalid format - expected 'type' line");
905                 goto done;
906         }
907         eol = strchr(buffer, '\n');
908         if (!eol) {
909                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE, "invalid format - unexpected end after 'type' line");
910                 goto done;
911         }
912         if (type_from_string_gently(buffer, eol - buffer, 1) < 0)
913                 ret = report(options, &tag->object, FSCK_MSG_BAD_TYPE, "invalid 'type' value");
914         if (ret)
915                 goto done;
916         buffer = eol + 1;
917
918         if (!skip_prefix(buffer, "tag ", &buffer)) {
919                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG_ENTRY, "invalid format - expected 'tag' line");
920                 goto done;
921         }
922         eol = strchr(buffer, '\n');
923         if (!eol) {
924                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG, "invalid format - unexpected end after 'type' line");
925                 goto done;
926         }
927         strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer);
928         if (check_refname_format(sb.buf, 0)) {
929                 ret = report(options, &tag->object, FSCK_MSG_BAD_TAG_NAME,
930                            "invalid 'tag' name: %.*s",
931                            (int)(eol - buffer), buffer);
932                 if (ret)
933                         goto done;
934         }
935         buffer = eol + 1;
936
937         if (!skip_prefix(buffer, "tagger ", &buffer)) {
938                 /* early tags do not contain 'tagger' lines; warn only */
939                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
940                 if (ret)
941                         goto done;
942         }
943         else
944                 ret = fsck_ident(&buffer, &tag->object, options);
945
946 done:
947         strbuf_release(&sb);
948         free(to_free);
949         return ret;
950 }
951
952 static int fsck_tag(struct tag *tag, const char *data,
953         unsigned long size, struct fsck_options *options)
954 {
955         struct object *tagged = tag->tagged;
956
957         if (!tagged)
958                 return report(options, &tag->object, FSCK_MSG_BAD_TAG_OBJECT, "could not load tagged object");
959
960         return fsck_tag_buffer(tag, data, size, options);
961 }
962
963 struct fsck_gitmodules_data {
964         struct object *obj;
965         struct fsck_options *options;
966         int ret;
967 };
968
969 static int fsck_gitmodules_fn(const char *var, const char *value, void *vdata)
970 {
971         struct fsck_gitmodules_data *data = vdata;
972         const char *subsection, *key;
973         int subsection_len;
974         char *name;
975
976         if (parse_config_key(var, "submodule", &subsection, &subsection_len, &key) < 0 ||
977             !subsection)
978                 return 0;
979
980         name = xmemdupz(subsection, subsection_len);
981         if (check_submodule_name(name) < 0)
982                 data->ret |= report(data->options, data->obj,
983                                     FSCK_MSG_GITMODULES_NAME,
984                                     "disallowed submodule name: %s",
985                                     name);
986         free(name);
987
988         return 0;
989 }
990
991 static int fsck_blob(struct blob *blob, const char *buf,
992                      unsigned long size, struct fsck_options *options)
993 {
994         struct fsck_gitmodules_data data;
995
996         if (!oidset_contains(&gitmodules_found, &blob->object.oid))
997                 return 0;
998         oidset_insert(&gitmodules_done, &blob->object.oid);
999
1000         if (!buf) {
1001                 /*
1002                  * A missing buffer here is a sign that the caller found the
1003                  * blob too gigantic to load into memory. Let's just consider
1004                  * that an error.
1005                  */
1006                 return report(options, &blob->object,
1007                               FSCK_MSG_GITMODULES_PARSE,
1008                               ".gitmodules too large to parse");
1009         }
1010
1011         data.obj = &blob->object;
1012         data.options = options;
1013         data.ret = 0;
1014         if (git_config_from_mem(fsck_gitmodules_fn, CONFIG_ORIGIN_BLOB,
1015                                 ".gitmodules", buf, size, &data, NULL))
1016                 data.ret |= report(options, &blob->object,
1017                                    FSCK_MSG_GITMODULES_PARSE,
1018                                    "could not parse gitmodules blob");
1019
1020         return data.ret;
1021 }
1022
1023 int fsck_object(struct object *obj, void *data, unsigned long size,
1024         struct fsck_options *options)
1025 {
1026         if (!obj)
1027                 return report(options, obj, FSCK_MSG_BAD_OBJECT_SHA1, "no valid object to fsck");
1028
1029         if (obj->type == OBJ_BLOB)
1030                 return fsck_blob((struct blob *)obj, data, size, options);
1031         if (obj->type == OBJ_TREE)
1032                 return fsck_tree((struct tree *) obj, options);
1033         if (obj->type == OBJ_COMMIT)
1034                 return fsck_commit((struct commit *) obj, (const char *) data,
1035                         size, options);
1036         if (obj->type == OBJ_TAG)
1037                 return fsck_tag((struct tag *) obj, (const char *) data,
1038                         size, options);
1039
1040         return report(options, obj, FSCK_MSG_UNKNOWN_TYPE, "unknown type '%d' (internal fsck error)",
1041                           obj->type);
1042 }
1043
1044 int fsck_error_function(struct fsck_options *o,
1045         struct object *obj, int msg_type, const char *message)
1046 {
1047         if (msg_type == FSCK_WARN) {
1048                 warning("object %s: %s", describe_object(o, obj), message);
1049                 return 0;
1050         }
1051         error("object %s: %s", describe_object(o, obj), message);
1052         return 1;
1053 }
1054
1055 int fsck_finish(struct fsck_options *options)
1056 {
1057         int ret = 0;
1058         struct oidset_iter iter;
1059         const struct object_id *oid;
1060
1061         oidset_iter_init(&gitmodules_found, &iter);
1062         while ((oid = oidset_iter_next(&iter))) {
1063                 struct blob *blob;
1064                 enum object_type type;
1065                 unsigned long size;
1066                 char *buf;
1067
1068                 if (oidset_contains(&gitmodules_done, oid))
1069                         continue;
1070
1071                 blob = lookup_blob(oid);
1072                 if (!blob) {
1073                         struct object *obj = lookup_unknown_object(oid->hash);
1074                         ret |= report(options, obj,
1075                                       FSCK_MSG_GITMODULES_BLOB,
1076                                       "non-blob found at .gitmodules");
1077                         continue;
1078                 }
1079
1080                 buf = read_object_file(oid, &type, &size);
1081                 if (!buf) {
1082                         if (is_promisor_object(&blob->object.oid))
1083                                 continue;
1084                         ret |= report(options, &blob->object,
1085                                       FSCK_MSG_GITMODULES_MISSING,
1086                                       "unable to read .gitmodules blob");
1087                         continue;
1088                 }
1089
1090                 if (type == OBJ_BLOB)
1091                         ret |= fsck_blob(blob, buf, size, options);
1092                 else
1093                         ret |= report(options, &blob->object,
1094                                       FSCK_MSG_GITMODULES_BLOB,
1095                                       "non-blob found at .gitmodules");
1096                 free(buf);
1097         }
1098
1099
1100         oidset_clear(&gitmodules_found);
1101         oidset_clear(&gitmodules_done);
1102         return ret;
1103 }