Imported Upstream version 2.19.5
[platform/upstream/git.git] / fsck.c
1 #include "cache.h"
2 #include "object-store.h"
3 #include "repository.h"
4 #include "object.h"
5 #include "blob.h"
6 #include "tree.h"
7 #include "tree-walk.h"
8 #include "commit.h"
9 #include "tag.h"
10 #include "fsck.h"
11 #include "refs.h"
12 #include "url.h"
13 #include "utf8.h"
14 #include "sha1-array.h"
15 #include "decorate.h"
16 #include "oidset.h"
17 #include "packfile.h"
18 #include "submodule-config.h"
19 #include "config.h"
20 #include "credential.h"
21 #include "help.h"
22
23 static struct oidset gitmodules_found = OIDSET_INIT;
24 static struct oidset gitmodules_done = OIDSET_INIT;
25
26 #define FSCK_FATAL -1
27 #define FSCK_INFO -2
28
29 #define FOREACH_MSG_ID(FUNC) \
30         /* fatal errors */ \
31         FUNC(NUL_IN_HEADER, FATAL) \
32         FUNC(UNTERMINATED_HEADER, FATAL) \
33         /* errors */ \
34         FUNC(BAD_DATE, ERROR) \
35         FUNC(BAD_DATE_OVERFLOW, ERROR) \
36         FUNC(BAD_EMAIL, ERROR) \
37         FUNC(BAD_NAME, ERROR) \
38         FUNC(BAD_OBJECT_SHA1, ERROR) \
39         FUNC(BAD_PARENT_SHA1, ERROR) \
40         FUNC(BAD_TAG_OBJECT, ERROR) \
41         FUNC(BAD_TIMEZONE, ERROR) \
42         FUNC(BAD_TREE, ERROR) \
43         FUNC(BAD_TREE_SHA1, ERROR) \
44         FUNC(BAD_TYPE, ERROR) \
45         FUNC(DUPLICATE_ENTRIES, ERROR) \
46         FUNC(MISSING_AUTHOR, ERROR) \
47         FUNC(MISSING_COMMITTER, ERROR) \
48         FUNC(MISSING_EMAIL, ERROR) \
49         FUNC(MISSING_GRAFT, ERROR) \
50         FUNC(MISSING_NAME_BEFORE_EMAIL, ERROR) \
51         FUNC(MISSING_OBJECT, ERROR) \
52         FUNC(MISSING_PARENT, ERROR) \
53         FUNC(MISSING_SPACE_BEFORE_DATE, ERROR) \
54         FUNC(MISSING_SPACE_BEFORE_EMAIL, ERROR) \
55         FUNC(MISSING_TAG, ERROR) \
56         FUNC(MISSING_TAG_ENTRY, ERROR) \
57         FUNC(MISSING_TAG_OBJECT, ERROR) \
58         FUNC(MISSING_TREE, ERROR) \
59         FUNC(MISSING_TREE_OBJECT, ERROR) \
60         FUNC(MISSING_TYPE, ERROR) \
61         FUNC(MISSING_TYPE_ENTRY, ERROR) \
62         FUNC(MULTIPLE_AUTHORS, ERROR) \
63         FUNC(TAG_OBJECT_NOT_TAG, ERROR) \
64         FUNC(TREE_NOT_SORTED, ERROR) \
65         FUNC(UNKNOWN_TYPE, ERROR) \
66         FUNC(ZERO_PADDED_DATE, ERROR) \
67         FUNC(GITMODULES_MISSING, ERROR) \
68         FUNC(GITMODULES_BLOB, ERROR) \
69         FUNC(GITMODULES_LARGE, ERROR) \
70         FUNC(GITMODULES_NAME, ERROR) \
71         FUNC(GITMODULES_SYMLINK, ERROR) \
72         FUNC(GITMODULES_URL, ERROR) \
73         FUNC(GITMODULES_PATH, ERROR) \
74         FUNC(GITMODULES_UPDATE, ERROR) \
75         /* warnings */ \
76         FUNC(BAD_FILEMODE, WARN) \
77         FUNC(EMPTY_NAME, WARN) \
78         FUNC(FULL_PATHNAME, WARN) \
79         FUNC(HAS_DOT, WARN) \
80         FUNC(HAS_DOTDOT, WARN) \
81         FUNC(HAS_DOTGIT, WARN) \
82         FUNC(NULL_SHA1, WARN) \
83         FUNC(ZERO_PADDED_FILEMODE, WARN) \
84         FUNC(NUL_IN_COMMIT, WARN) \
85         /* infos (reported as warnings, but ignored by default) */ \
86         FUNC(GITMODULES_PARSE, INFO) \
87         FUNC(BAD_TAG_NAME, INFO) \
88         FUNC(MISSING_TAGGER_ENTRY, INFO)
89
90 #define MSG_ID(id, msg_type) FSCK_MSG_##id,
91 enum fsck_msg_id {
92         FOREACH_MSG_ID(MSG_ID)
93         FSCK_MSG_MAX
94 };
95 #undef MSG_ID
96
97 #define STR(x) #x
98 #define MSG_ID(id, msg_type) { STR(id), NULL, NULL, FSCK_##msg_type },
99 static struct {
100         const char *id_string;
101         const char *downcased;
102         const char *camelcased;
103         int msg_type;
104 } msg_id_info[FSCK_MSG_MAX + 1] = {
105         FOREACH_MSG_ID(MSG_ID)
106         { NULL, NULL, NULL, -1 }
107 };
108 #undef MSG_ID
109
110 static void prepare_msg_ids(void)
111 {
112         int i;
113
114         if (msg_id_info[0].downcased)
115                 return;
116
117         /* convert id_string to lower case, without underscores. */
118         for (i = 0; i < FSCK_MSG_MAX; i++) {
119                 const char *p = msg_id_info[i].id_string;
120                 int len = strlen(p);
121                 char *q = xmalloc(len);
122
123                 msg_id_info[i].downcased = q;
124                 while (*p)
125                         if (*p == '_')
126                                 p++;
127                         else
128                                 *(q)++ = tolower(*(p)++);
129                 *q = '\0';
130
131                 p = msg_id_info[i].id_string;
132                 q = xmalloc(len);
133                 msg_id_info[i].camelcased = q;
134                 while (*p) {
135                         if (*p == '_') {
136                                 p++;
137                                 if (*p)
138                                         *q++ = *p++;
139                         } else {
140                                 *q++ = tolower(*p++);
141                         }
142                 }
143                 *q = '\0';
144         }
145 }
146
147 static int parse_msg_id(const char *text)
148 {
149         int i;
150
151         prepare_msg_ids();
152
153         for (i = 0; i < FSCK_MSG_MAX; i++)
154                 if (!strcmp(text, msg_id_info[i].downcased))
155                         return i;
156
157         return -1;
158 }
159
160 void list_config_fsck_msg_ids(struct string_list *list, const char *prefix)
161 {
162         int i;
163
164         prepare_msg_ids();
165
166         for (i = 0; i < FSCK_MSG_MAX; i++)
167                 list_config_item(list, prefix, msg_id_info[i].camelcased);
168 }
169
170 static int fsck_msg_type(enum fsck_msg_id msg_id,
171         struct fsck_options *options)
172 {
173         int msg_type;
174
175         assert(msg_id >= 0 && msg_id < FSCK_MSG_MAX);
176
177         if (options->msg_type)
178                 msg_type = options->msg_type[msg_id];
179         else {
180                 msg_type = msg_id_info[msg_id].msg_type;
181                 if (options->strict && msg_type == FSCK_WARN)
182                         msg_type = FSCK_ERROR;
183         }
184
185         return msg_type;
186 }
187
188 static void init_skiplist(struct fsck_options *options, const char *path)
189 {
190         static struct oid_array skiplist = OID_ARRAY_INIT;
191         int sorted, fd;
192         char buffer[GIT_MAX_HEXSZ + 1];
193         struct object_id oid;
194
195         if (options->skiplist)
196                 sorted = options->skiplist->sorted;
197         else {
198                 sorted = 1;
199                 options->skiplist = &skiplist;
200         }
201
202         fd = open(path, O_RDONLY);
203         if (fd < 0)
204                 die("Could not open skip list: %s", path);
205         for (;;) {
206                 const char *p;
207                 int result = read_in_full(fd, buffer, sizeof(buffer));
208                 if (result < 0)
209                         die_errno("Could not read '%s'", path);
210                 if (!result)
211                         break;
212                 if (parse_oid_hex(buffer, &oid, &p) || *p != '\n')
213                         die("Invalid SHA-1: %s", buffer);
214                 oid_array_append(&skiplist, &oid);
215                 if (sorted && skiplist.nr > 1 &&
216                                 oidcmp(&skiplist.oid[skiplist.nr - 2],
217                                        &oid) > 0)
218                         sorted = 0;
219         }
220         close(fd);
221
222         if (sorted)
223                 skiplist.sorted = 1;
224 }
225
226 static int parse_msg_type(const char *str)
227 {
228         if (!strcmp(str, "error"))
229                 return FSCK_ERROR;
230         else if (!strcmp(str, "warn"))
231                 return FSCK_WARN;
232         else if (!strcmp(str, "ignore"))
233                 return FSCK_IGNORE;
234         else
235                 die("Unknown fsck message type: '%s'", str);
236 }
237
238 int is_valid_msg_type(const char *msg_id, const char *msg_type)
239 {
240         if (parse_msg_id(msg_id) < 0)
241                 return 0;
242         parse_msg_type(msg_type);
243         return 1;
244 }
245
246 void fsck_set_msg_type(struct fsck_options *options,
247                 const char *msg_id, const char *msg_type)
248 {
249         int id = parse_msg_id(msg_id), type;
250
251         if (id < 0)
252                 die("Unhandled message id: %s", msg_id);
253         type = parse_msg_type(msg_type);
254
255         if (type != FSCK_ERROR && msg_id_info[id].msg_type == FSCK_FATAL)
256                 die("Cannot demote %s to %s", msg_id, msg_type);
257
258         if (!options->msg_type) {
259                 int i;
260                 int *msg_type;
261                 ALLOC_ARRAY(msg_type, FSCK_MSG_MAX);
262                 for (i = 0; i < FSCK_MSG_MAX; i++)
263                         msg_type[i] = fsck_msg_type(i, options);
264                 options->msg_type = msg_type;
265         }
266
267         options->msg_type[id] = type;
268 }
269
270 void fsck_set_msg_types(struct fsck_options *options, const char *values)
271 {
272         char *buf = xstrdup(values), *to_free = buf;
273         int done = 0;
274
275         while (!done) {
276                 int len = strcspn(buf, " ,|"), equal;
277
278                 done = !buf[len];
279                 if (!len) {
280                         buf++;
281                         continue;
282                 }
283                 buf[len] = '\0';
284
285                 for (equal = 0;
286                      equal < len && buf[equal] != '=' && buf[equal] != ':';
287                      equal++)
288                         buf[equal] = tolower(buf[equal]);
289                 buf[equal] = '\0';
290
291                 if (!strcmp(buf, "skiplist")) {
292                         if (equal == len)
293                                 die("skiplist requires a path");
294                         init_skiplist(options, buf + equal + 1);
295                         buf += len + 1;
296                         continue;
297                 }
298
299                 if (equal == len)
300                         die("Missing '=': '%s'", buf);
301
302                 fsck_set_msg_type(options, buf, buf + equal + 1);
303                 buf += len + 1;
304         }
305         free(to_free);
306 }
307
308 static void append_msg_id(struct strbuf *sb, const char *msg_id)
309 {
310         for (;;) {
311                 char c = *(msg_id)++;
312
313                 if (!c)
314                         break;
315                 if (c != '_')
316                         strbuf_addch(sb, tolower(c));
317                 else {
318                         assert(*msg_id);
319                         strbuf_addch(sb, *(msg_id)++);
320                 }
321         }
322
323         strbuf_addstr(sb, ": ");
324 }
325
326 static int object_on_skiplist(struct fsck_options *opts, struct object *obj)
327 {
328         if (opts && opts->skiplist && obj)
329                 return oid_array_lookup(opts->skiplist, &obj->oid) >= 0;
330         return 0;
331 }
332
333 __attribute__((format (printf, 4, 5)))
334 static int report(struct fsck_options *options, struct object *object,
335         enum fsck_msg_id id, const char *fmt, ...)
336 {
337         va_list ap;
338         struct strbuf sb = STRBUF_INIT;
339         int msg_type = fsck_msg_type(id, options), result;
340
341         if (msg_type == FSCK_IGNORE)
342                 return 0;
343
344         if (object_on_skiplist(options, object))
345                 return 0;
346
347         if (msg_type == FSCK_FATAL)
348                 msg_type = FSCK_ERROR;
349         else if (msg_type == FSCK_INFO)
350                 msg_type = FSCK_WARN;
351
352         append_msg_id(&sb, msg_id_info[id].id_string);
353
354         va_start(ap, fmt);
355         strbuf_vaddf(&sb, fmt, ap);
356         result = options->error_func(options, object, msg_type, sb.buf);
357         strbuf_release(&sb);
358         va_end(ap);
359
360         return result;
361 }
362
363 static char *get_object_name(struct fsck_options *options, struct object *obj)
364 {
365         if (!options->object_names)
366                 return NULL;
367         return lookup_decoration(options->object_names, obj);
368 }
369
370 static void put_object_name(struct fsck_options *options, struct object *obj,
371         const char *fmt, ...)
372 {
373         va_list ap;
374         struct strbuf buf = STRBUF_INIT;
375         char *existing;
376
377         if (!options->object_names)
378                 return;
379         existing = lookup_decoration(options->object_names, obj);
380         if (existing)
381                 return;
382         va_start(ap, fmt);
383         strbuf_vaddf(&buf, fmt, ap);
384         add_decoration(options->object_names, obj, strbuf_detach(&buf, NULL));
385         va_end(ap);
386 }
387
388 static const char *describe_object(struct fsck_options *o, struct object *obj)
389 {
390         static struct strbuf buf = STRBUF_INIT;
391         char *name;
392
393         strbuf_reset(&buf);
394         strbuf_addstr(&buf, oid_to_hex(&obj->oid));
395         if (o->object_names && (name = lookup_decoration(o->object_names, obj)))
396                 strbuf_addf(&buf, " (%s)", name);
397
398         return buf.buf;
399 }
400
401 static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *options)
402 {
403         struct tree_desc desc;
404         struct name_entry entry;
405         int res = 0;
406         const char *name;
407
408         if (parse_tree(tree))
409                 return -1;
410
411         name = get_object_name(options, &tree->object);
412         if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
413                 return -1;
414         while (tree_entry_gently(&desc, &entry)) {
415                 struct object *obj;
416                 int result;
417
418                 if (S_ISGITLINK(entry.mode))
419                         continue;
420
421                 if (S_ISDIR(entry.mode)) {
422                         obj = (struct object *)lookup_tree(the_repository, entry.oid);
423                         if (name && obj)
424                                 put_object_name(options, obj, "%s%s/", name,
425                                         entry.path);
426                         result = options->walk(obj, OBJ_TREE, data, options);
427                 }
428                 else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode)) {
429                         obj = (struct object *)lookup_blob(the_repository, entry.oid);
430                         if (name && obj)
431                                 put_object_name(options, obj, "%s%s", name,
432                                         entry.path);
433                         result = options->walk(obj, OBJ_BLOB, data, options);
434                 }
435                 else {
436                         result = error("in tree %s: entry %s has bad mode %.6o",
437                                         describe_object(options, &tree->object), entry.path, entry.mode);
438                 }
439                 if (result < 0)
440                         return result;
441                 if (!res)
442                         res = result;
443         }
444         return res;
445 }
446
447 static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_options *options)
448 {
449         int counter = 0, generation = 0, name_prefix_len = 0;
450         struct commit_list *parents;
451         int res;
452         int result;
453         const char *name;
454
455         if (parse_commit(commit))
456                 return -1;
457
458         name = get_object_name(options, &commit->object);
459         if (name)
460                 put_object_name(options, &get_commit_tree(commit)->object,
461                                 "%s:", name);
462
463         result = options->walk((struct object *)get_commit_tree(commit),
464                                OBJ_TREE, data, options);
465         if (result < 0)
466                 return result;
467         res = result;
468
469         parents = commit->parents;
470         if (name && parents) {
471                 int len = strlen(name), power;
472
473                 if (len && name[len - 1] == '^') {
474                         generation = 1;
475                         name_prefix_len = len - 1;
476                 }
477                 else { /* parse ~<generation> suffix */
478                         for (generation = 0, power = 1;
479                              len && isdigit(name[len - 1]);
480                              power *= 10)
481                                 generation += power * (name[--len] - '0');
482                         if (power > 1 && len && name[len - 1] == '~')
483                                 name_prefix_len = len - 1;
484                 }
485         }
486
487         while (parents) {
488                 if (name) {
489                         struct object *obj = &parents->item->object;
490
491                         if (counter++)
492                                 put_object_name(options, obj, "%s^%d",
493                                         name, counter);
494                         else if (generation > 0)
495                                 put_object_name(options, obj, "%.*s~%d",
496                                         name_prefix_len, name, generation + 1);
497                         else
498                                 put_object_name(options, obj, "%s^", name);
499                 }
500                 result = options->walk((struct object *)parents->item, OBJ_COMMIT, data, options);
501                 if (result < 0)
502                         return result;
503                 if (!res)
504                         res = result;
505                 parents = parents->next;
506         }
507         return res;
508 }
509
510 static int fsck_walk_tag(struct tag *tag, void *data, struct fsck_options *options)
511 {
512         char *name = get_object_name(options, &tag->object);
513
514         if (parse_tag(tag))
515                 return -1;
516         if (name)
517                 put_object_name(options, tag->tagged, "%s", name);
518         return options->walk(tag->tagged, OBJ_ANY, data, options);
519 }
520
521 int fsck_walk(struct object *obj, void *data, struct fsck_options *options)
522 {
523         if (!obj)
524                 return -1;
525
526         if (obj->type == OBJ_NONE)
527                 parse_object(the_repository, &obj->oid);
528
529         switch (obj->type) {
530         case OBJ_BLOB:
531                 return 0;
532         case OBJ_TREE:
533                 return fsck_walk_tree((struct tree *)obj, data, options);
534         case OBJ_COMMIT:
535                 return fsck_walk_commit((struct commit *)obj, data, options);
536         case OBJ_TAG:
537                 return fsck_walk_tag((struct tag *)obj, data, options);
538         default:
539                 error("Unknown object type for %s", describe_object(options, obj));
540                 return -1;
541         }
542 }
543
544 /*
545  * The entries in a tree are ordered in the _path_ order,
546  * which means that a directory entry is ordered by adding
547  * a slash to the end of it.
548  *
549  * So a directory called "a" is ordered _after_ a file
550  * called "a.c", because "a/" sorts after "a.c".
551  */
552 #define TREE_UNORDERED (-1)
553 #define TREE_HAS_DUPS  (-2)
554
555 static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
556 {
557         int len1 = strlen(name1);
558         int len2 = strlen(name2);
559         int len = len1 < len2 ? len1 : len2;
560         unsigned char c1, c2;
561         int cmp;
562
563         cmp = memcmp(name1, name2, len);
564         if (cmp < 0)
565                 return 0;
566         if (cmp > 0)
567                 return TREE_UNORDERED;
568
569         /*
570          * Ok, the first <len> characters are the same.
571          * Now we need to order the next one, but turn
572          * a '\0' into a '/' for a directory entry.
573          */
574         c1 = name1[len];
575         c2 = name2[len];
576         if (!c1 && !c2)
577                 /*
578                  * git-write-tree used to write out a nonsense tree that has
579                  * entries with the same name, one blob and one tree.  Make
580                  * sure we do not have duplicate entries.
581                  */
582                 return TREE_HAS_DUPS;
583         if (!c1 && S_ISDIR(mode1))
584                 c1 = '/';
585         if (!c2 && S_ISDIR(mode2))
586                 c2 = '/';
587         return c1 < c2 ? 0 : TREE_UNORDERED;
588 }
589
590 static int fsck_tree(struct tree *item, struct fsck_options *options)
591 {
592         int retval = 0;
593         int has_null_sha1 = 0;
594         int has_full_path = 0;
595         int has_empty_name = 0;
596         int has_dot = 0;
597         int has_dotdot = 0;
598         int has_dotgit = 0;
599         int has_zero_pad = 0;
600         int has_bad_modes = 0;
601         int has_dup_entries = 0;
602         int not_properly_sorted = 0;
603         struct tree_desc desc;
604         unsigned o_mode;
605         const char *o_name;
606
607         if (init_tree_desc_gently(&desc, item->buffer, item->size)) {
608                 retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
609                 return retval;
610         }
611
612         o_mode = 0;
613         o_name = NULL;
614
615         while (desc.size) {
616                 unsigned mode;
617                 const char *name, *backslash;
618                 const struct object_id *oid;
619
620                 oid = tree_entry_extract(&desc, &name, &mode);
621
622                 has_null_sha1 |= is_null_oid(oid);
623                 has_full_path |= !!strchr(name, '/');
624                 has_empty_name |= !*name;
625                 has_dot |= !strcmp(name, ".");
626                 has_dotdot |= !strcmp(name, "..");
627                 has_dotgit |= is_hfs_dotgit(name) || is_ntfs_dotgit(name);
628                 has_zero_pad |= *(char *)desc.buffer == '0';
629
630                 if (is_hfs_dotgitmodules(name) || is_ntfs_dotgitmodules(name)) {
631                         if (!S_ISLNK(mode))
632                                 oidset_insert(&gitmodules_found, oid);
633                         else
634                                 retval += report(options, &item->object,
635                                                  FSCK_MSG_GITMODULES_SYMLINK,
636                                                  ".gitmodules is a symbolic link");
637                 }
638
639                 if ((backslash = strchr(name, '\\'))) {
640                         while (backslash) {
641                                 backslash++;
642                                 has_dotgit |= is_ntfs_dotgit(backslash);
643                                 if (is_ntfs_dotgitmodules(backslash)) {
644                                         if (!S_ISLNK(mode))
645                                                 oidset_insert(&gitmodules_found, oid);
646                                         else
647                                                 retval += report(options, &item->object,
648                                                                  FSCK_MSG_GITMODULES_SYMLINK,
649                                                                  ".gitmodules is a symbolic link");
650                                 }
651                                 backslash = strchr(backslash, '\\');
652                         }
653                 }
654
655                 if (update_tree_entry_gently(&desc)) {
656                         retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
657                         break;
658                 }
659
660                 switch (mode) {
661                 /*
662                  * Standard modes..
663                  */
664                 case S_IFREG | 0755:
665                 case S_IFREG | 0644:
666                 case S_IFLNK:
667                 case S_IFDIR:
668                 case S_IFGITLINK:
669                         break;
670                 /*
671                  * This is nonstandard, but we had a few of these
672                  * early on when we honored the full set of mode
673                  * bits..
674                  */
675                 case S_IFREG | 0664:
676                         if (!options->strict)
677                                 break;
678                         /* fallthrough */
679                 default:
680                         has_bad_modes = 1;
681                 }
682
683                 if (o_name) {
684                         switch (verify_ordered(o_mode, o_name, mode, name)) {
685                         case TREE_UNORDERED:
686                                 not_properly_sorted = 1;
687                                 break;
688                         case TREE_HAS_DUPS:
689                                 has_dup_entries = 1;
690                                 break;
691                         default:
692                                 break;
693                         }
694                 }
695
696                 o_mode = mode;
697                 o_name = name;
698         }
699
700         if (has_null_sha1)
701                 retval += report(options, &item->object, FSCK_MSG_NULL_SHA1, "contains entries pointing to null sha1");
702         if (has_full_path)
703                 retval += report(options, &item->object, FSCK_MSG_FULL_PATHNAME, "contains full pathnames");
704         if (has_empty_name)
705                 retval += report(options, &item->object, FSCK_MSG_EMPTY_NAME, "contains empty pathname");
706         if (has_dot)
707                 retval += report(options, &item->object, FSCK_MSG_HAS_DOT, "contains '.'");
708         if (has_dotdot)
709                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTDOT, "contains '..'");
710         if (has_dotgit)
711                 retval += report(options, &item->object, FSCK_MSG_HAS_DOTGIT, "contains '.git'");
712         if (has_zero_pad)
713                 retval += report(options, &item->object, FSCK_MSG_ZERO_PADDED_FILEMODE, "contains zero-padded file modes");
714         if (has_bad_modes)
715                 retval += report(options, &item->object, FSCK_MSG_BAD_FILEMODE, "contains bad file modes");
716         if (has_dup_entries)
717                 retval += report(options, &item->object, FSCK_MSG_DUPLICATE_ENTRIES, "contains duplicate file entries");
718         if (not_properly_sorted)
719                 retval += report(options, &item->object, FSCK_MSG_TREE_NOT_SORTED, "not properly sorted");
720         return retval;
721 }
722
723 static int verify_headers(const void *data, unsigned long size,
724                           struct object *obj, struct fsck_options *options)
725 {
726         const char *buffer = (const char *)data;
727         unsigned long i;
728
729         for (i = 0; i < size; i++) {
730                 switch (buffer[i]) {
731                 case '\0':
732                         return report(options, obj,
733                                 FSCK_MSG_NUL_IN_HEADER,
734                                 "unterminated header: NUL at offset %ld", i);
735                 case '\n':
736                         if (i + 1 < size && buffer[i + 1] == '\n')
737                                 return 0;
738                 }
739         }
740
741         /*
742          * We did not find double-LF that separates the header
743          * and the body.  Not having a body is not a crime but
744          * we do want to see the terminating LF for the last header
745          * line.
746          */
747         if (size && buffer[size - 1] == '\n')
748                 return 0;
749
750         return report(options, obj,
751                 FSCK_MSG_UNTERMINATED_HEADER, "unterminated header");
752 }
753
754 static int fsck_ident(const char **ident, struct object *obj, struct fsck_options *options)
755 {
756         const char *p = *ident;
757         char *end;
758
759         *ident = strchrnul(*ident, '\n');
760         if (**ident == '\n')
761                 (*ident)++;
762
763         if (*p == '<')
764                 return report(options, obj, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
765         p += strcspn(p, "<>\n");
766         if (*p == '>')
767                 return report(options, obj, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
768         if (*p != '<')
769                 return report(options, obj, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
770         if (p[-1] != ' ')
771                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
772         p++;
773         p += strcspn(p, "<>\n");
774         if (*p != '>')
775                 return report(options, obj, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
776         p++;
777         if (*p != ' ')
778                 return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
779         p++;
780         if (*p == '0' && p[1] != ' ')
781                 return report(options, obj, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
782         if (date_overflows(parse_timestamp(p, &end, 10)))
783                 return report(options, obj, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
784         if ((end == p || *end != ' '))
785                 return report(options, obj, FSCK_MSG_BAD_DATE, "invalid author/committer line - bad date");
786         p = end + 1;
787         if ((*p != '+' && *p != '-') ||
788             !isdigit(p[1]) ||
789             !isdigit(p[2]) ||
790             !isdigit(p[3]) ||
791             !isdigit(p[4]) ||
792             (p[5] != '\n'))
793                 return report(options, obj, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
794         p += 6;
795         return 0;
796 }
797
798 static int fsck_commit_buffer(struct commit *commit, const char *buffer,
799         unsigned long size, struct fsck_options *options)
800 {
801         struct object_id tree_oid, oid;
802         struct commit_graft *graft;
803         unsigned parent_count, parent_line_count = 0, author_count;
804         int err;
805         const char *buffer_begin = buffer;
806         const char *p;
807
808         if (verify_headers(buffer, size, &commit->object, options))
809                 return -1;
810
811         if (!skip_prefix(buffer, "tree ", &buffer))
812                 return report(options, &commit->object, FSCK_MSG_MISSING_TREE, "invalid format - expected 'tree' line");
813         if (parse_oid_hex(buffer, &tree_oid, &p) || *p != '\n') {
814                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE_SHA1, "invalid 'tree' line format - bad sha1");
815                 if (err)
816                         return err;
817         }
818         buffer = p + 1;
819         while (skip_prefix(buffer, "parent ", &buffer)) {
820                 if (parse_oid_hex(buffer, &oid, &p) || *p != '\n') {
821                         err = report(options, &commit->object, FSCK_MSG_BAD_PARENT_SHA1, "invalid 'parent' line format - bad sha1");
822                         if (err)
823                                 return err;
824                 }
825                 buffer = p + 1;
826                 parent_line_count++;
827         }
828         graft = lookup_commit_graft(the_repository, &commit->object.oid);
829         parent_count = commit_list_count(commit->parents);
830         if (graft) {
831                 if (graft->nr_parent == -1 && !parent_count)
832                         ; /* shallow commit */
833                 else if (graft->nr_parent != parent_count) {
834                         err = report(options, &commit->object, FSCK_MSG_MISSING_GRAFT, "graft objects missing");
835                         if (err)
836                                 return err;
837                 }
838         } else {
839                 if (parent_count != parent_line_count) {
840                         err = report(options, &commit->object, FSCK_MSG_MISSING_PARENT, "parent objects missing");
841                         if (err)
842                                 return err;
843                 }
844         }
845         author_count = 0;
846         while (skip_prefix(buffer, "author ", &buffer)) {
847                 author_count++;
848                 err = fsck_ident(&buffer, &commit->object, options);
849                 if (err)
850                         return err;
851         }
852         if (author_count < 1)
853                 err = report(options, &commit->object, FSCK_MSG_MISSING_AUTHOR, "invalid format - expected 'author' line");
854         else if (author_count > 1)
855                 err = report(options, &commit->object, FSCK_MSG_MULTIPLE_AUTHORS, "invalid format - multiple 'author' lines");
856         if (err)
857                 return err;
858         if (!skip_prefix(buffer, "committer ", &buffer))
859                 return report(options, &commit->object, FSCK_MSG_MISSING_COMMITTER, "invalid format - expected 'committer' line");
860         err = fsck_ident(&buffer, &commit->object, options);
861         if (err)
862                 return err;
863         if (!get_commit_tree(commit)) {
864                 err = report(options, &commit->object, FSCK_MSG_BAD_TREE, "could not load commit's tree %s", oid_to_hex(&tree_oid));
865                 if (err)
866                         return err;
867         }
868         if (memchr(buffer_begin, '\0', size)) {
869                 err = report(options, &commit->object, FSCK_MSG_NUL_IN_COMMIT,
870                              "NUL byte in the commit object body");
871                 if (err)
872                         return err;
873         }
874         return 0;
875 }
876
877 static int fsck_commit(struct commit *commit, const char *data,
878         unsigned long size, struct fsck_options *options)
879 {
880         const char *buffer = data ?  data : get_commit_buffer(commit, &size);
881         int ret = fsck_commit_buffer(commit, buffer, size, options);
882         if (!data)
883                 unuse_commit_buffer(commit, buffer);
884         return ret;
885 }
886
887 static int fsck_tag_buffer(struct tag *tag, const char *data,
888         unsigned long size, struct fsck_options *options)
889 {
890         struct object_id oid;
891         int ret = 0;
892         const char *buffer;
893         char *to_free = NULL, *eol;
894         struct strbuf sb = STRBUF_INIT;
895         const char *p;
896
897         if (data)
898                 buffer = data;
899         else {
900                 enum object_type type;
901
902                 buffer = to_free =
903                         read_object_file(&tag->object.oid, &type, &size);
904                 if (!buffer)
905                         return report(options, &tag->object,
906                                 FSCK_MSG_MISSING_TAG_OBJECT,
907                                 "cannot read tag object");
908
909                 if (type != OBJ_TAG) {
910                         ret = report(options, &tag->object,
911                                 FSCK_MSG_TAG_OBJECT_NOT_TAG,
912                                 "expected tag got %s",
913                             type_name(type));
914                         goto done;
915                 }
916         }
917
918         ret = verify_headers(buffer, size, &tag->object, options);
919         if (ret)
920                 goto done;
921
922         if (!skip_prefix(buffer, "object ", &buffer)) {
923                 ret = report(options, &tag->object, FSCK_MSG_MISSING_OBJECT, "invalid format - expected 'object' line");
924                 goto done;
925         }
926         if (parse_oid_hex(buffer, &oid, &p) || *p != '\n') {
927                 ret = report(options, &tag->object, FSCK_MSG_BAD_OBJECT_SHA1, "invalid 'object' line format - bad sha1");
928                 if (ret)
929                         goto done;
930         }
931         buffer = p + 1;
932
933         if (!skip_prefix(buffer, "type ", &buffer)) {
934                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE_ENTRY, "invalid format - expected 'type' line");
935                 goto done;
936         }
937         eol = strchr(buffer, '\n');
938         if (!eol) {
939                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE, "invalid format - unexpected end after 'type' line");
940                 goto done;
941         }
942         if (type_from_string_gently(buffer, eol - buffer, 1) < 0)
943                 ret = report(options, &tag->object, FSCK_MSG_BAD_TYPE, "invalid 'type' value");
944         if (ret)
945                 goto done;
946         buffer = eol + 1;
947
948         if (!skip_prefix(buffer, "tag ", &buffer)) {
949                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG_ENTRY, "invalid format - expected 'tag' line");
950                 goto done;
951         }
952         eol = strchr(buffer, '\n');
953         if (!eol) {
954                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG, "invalid format - unexpected end after 'type' line");
955                 goto done;
956         }
957         strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer);
958         if (check_refname_format(sb.buf, 0)) {
959                 ret = report(options, &tag->object, FSCK_MSG_BAD_TAG_NAME,
960                            "invalid 'tag' name: %.*s",
961                            (int)(eol - buffer), buffer);
962                 if (ret)
963                         goto done;
964         }
965         buffer = eol + 1;
966
967         if (!skip_prefix(buffer, "tagger ", &buffer)) {
968                 /* early tags do not contain 'tagger' lines; warn only */
969                 ret = report(options, &tag->object, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
970                 if (ret)
971                         goto done;
972         }
973         else
974                 ret = fsck_ident(&buffer, &tag->object, options);
975
976 done:
977         strbuf_release(&sb);
978         free(to_free);
979         return ret;
980 }
981
982 static int fsck_tag(struct tag *tag, const char *data,
983         unsigned long size, struct fsck_options *options)
984 {
985         struct object *tagged = tag->tagged;
986
987         if (!tagged)
988                 return report(options, &tag->object, FSCK_MSG_BAD_TAG_OBJECT, "could not load tagged object");
989
990         return fsck_tag_buffer(tag, data, size, options);
991 }
992
993 /*
994  * Like builtin/submodule--helper.c's starts_with_dot_slash, but without
995  * relying on the platform-dependent is_dir_sep helper.
996  *
997  * This is for use in checking whether a submodule URL is interpreted as
998  * relative to the current directory on any platform, since \ is a
999  * directory separator on Windows but not on other platforms.
1000  */
1001 static int starts_with_dot_slash(const char *str)
1002 {
1003         return str[0] == '.' && (str[1] == '/' || str[1] == '\\');
1004 }
1005
1006 /*
1007  * Like starts_with_dot_slash, this is a variant of submodule--helper's
1008  * helper of the same name with the twist that it accepts backslash as a
1009  * directory separator even on non-Windows platforms.
1010  */
1011 static int starts_with_dot_dot_slash(const char *str)
1012 {
1013         return str[0] == '.' && starts_with_dot_slash(str + 1);
1014 }
1015
1016 static int submodule_url_is_relative(const char *url)
1017 {
1018         return starts_with_dot_slash(url) || starts_with_dot_dot_slash(url);
1019 }
1020
1021 /*
1022  * Count directory components that a relative submodule URL should chop
1023  * from the remote_url it is to be resolved against.
1024  *
1025  * In other words, this counts "../" components at the start of a
1026  * submodule URL.
1027  *
1028  * Returns the number of directory components to chop and writes a
1029  * pointer to the next character of url after all leading "./" and
1030  * "../" components to out.
1031  */
1032 static int count_leading_dotdots(const char *url, const char **out)
1033 {
1034         int result = 0;
1035         while (1) {
1036                 if (starts_with_dot_dot_slash(url)) {
1037                         result++;
1038                         url += strlen("../");
1039                         continue;
1040                 }
1041                 if (starts_with_dot_slash(url)) {
1042                         url += strlen("./");
1043                         continue;
1044                 }
1045                 *out = url;
1046                 return result;
1047         }
1048 }
1049 /*
1050  * Check whether a transport is implemented by git-remote-curl.
1051  *
1052  * If it is, returns 1 and writes the URL that would be passed to
1053  * git-remote-curl to the "out" parameter.
1054  *
1055  * Otherwise, returns 0 and leaves "out" untouched.
1056  *
1057  * Examples:
1058  *   http::https://example.com/repo.git -> 1, https://example.com/repo.git
1059  *   https://example.com/repo.git -> 1, https://example.com/repo.git
1060  *   git://example.com/repo.git -> 0
1061  *
1062  * This is for use in checking for previously exploitable bugs that
1063  * required a submodule URL to be passed to git-remote-curl.
1064  */
1065 static int url_to_curl_url(const char *url, const char **out)
1066 {
1067         /*
1068          * We don't need to check for case-aliases, "http.exe", and so
1069          * on because in the default configuration, is_transport_allowed
1070          * prevents URLs with those schemes from being cloned
1071          * automatically.
1072          */
1073         if (skip_prefix(url, "http::", out) ||
1074             skip_prefix(url, "https::", out) ||
1075             skip_prefix(url, "ftp::", out) ||
1076             skip_prefix(url, "ftps::", out))
1077                 return 1;
1078         if (starts_with(url, "http://") ||
1079             starts_with(url, "https://") ||
1080             starts_with(url, "ftp://") ||
1081             starts_with(url, "ftps://")) {
1082                 *out = url;
1083                 return 1;
1084         }
1085         return 0;
1086 }
1087
1088 static int check_submodule_url(const char *url)
1089 {
1090         const char *curl_url;
1091
1092         if (looks_like_command_line_option(url))
1093                 return -1;
1094
1095         if (submodule_url_is_relative(url)) {
1096                 char *decoded;
1097                 const char *next;
1098                 int has_nl;
1099
1100                 /*
1101                  * This could be appended to an http URL and url-decoded;
1102                  * check for malicious characters.
1103                  */
1104                 decoded = url_decode(url);
1105                 has_nl = !!strchr(decoded, '\n');
1106
1107                 free(decoded);
1108                 if (has_nl)
1109                         return -1;
1110
1111                 /*
1112                  * URLs which escape their root via "../" can overwrite
1113                  * the host field and previous components, resolving to
1114                  * URLs like https::example.com/submodule.git and
1115                  * https:///example.com/submodule.git that were
1116                  * susceptible to CVE-2020-11008.
1117                  */
1118                 if (count_leading_dotdots(url, &next) > 0 &&
1119                     (*next == ':' || *next == '/'))
1120                         return -1;
1121         }
1122
1123         else if (url_to_curl_url(url, &curl_url)) {
1124                 struct credential c = CREDENTIAL_INIT;
1125                 int ret = 0;
1126                 if (credential_from_url_gently(&c, curl_url, 1) ||
1127                     !*c.host)
1128                         ret = -1;
1129                 credential_clear(&c);
1130                 return ret;
1131         }
1132
1133         return 0;
1134 }
1135
1136 struct fsck_gitmodules_data {
1137         struct object *obj;
1138         struct fsck_options *options;
1139         int ret;
1140 };
1141
1142 static int fsck_gitmodules_fn(const char *var, const char *value, void *vdata)
1143 {
1144         struct fsck_gitmodules_data *data = vdata;
1145         const char *subsection, *key;
1146         int subsection_len;
1147         char *name;
1148
1149         if (parse_config_key(var, "submodule", &subsection, &subsection_len, &key) < 0 ||
1150             !subsection)
1151                 return 0;
1152
1153         name = xmemdupz(subsection, subsection_len);
1154         if (check_submodule_name(name) < 0)
1155                 data->ret |= report(data->options, data->obj,
1156                                     FSCK_MSG_GITMODULES_NAME,
1157                                     "disallowed submodule name: %s",
1158                                     name);
1159         if (!strcmp(key, "url") && value &&
1160             check_submodule_url(value) < 0)
1161                 data->ret |= report(data->options, data->obj,
1162                                     FSCK_MSG_GITMODULES_URL,
1163                                     "disallowed submodule url: %s",
1164                                     value);
1165         if (!strcmp(key, "path") && value &&
1166             looks_like_command_line_option(value))
1167                 data->ret |= report(data->options, data->obj,
1168                                     FSCK_MSG_GITMODULES_PATH,
1169                                     "disallowed submodule path: %s",
1170                                     value);
1171         if (!strcmp(key, "update") && value &&
1172             parse_submodule_update_type(value) == SM_UPDATE_COMMAND)
1173                 data->ret |= report(data->options, data->obj,
1174                                     FSCK_MSG_GITMODULES_UPDATE,
1175                                     "disallowed submodule update setting: %s",
1176                                     value);
1177         free(name);
1178
1179         return 0;
1180 }
1181
1182 static int fsck_blob(struct blob *blob, const char *buf,
1183                      unsigned long size, struct fsck_options *options)
1184 {
1185         struct fsck_gitmodules_data data;
1186         struct config_options config_opts = { 0 };
1187
1188         if (!oidset_contains(&gitmodules_found, &blob->object.oid))
1189                 return 0;
1190         oidset_insert(&gitmodules_done, &blob->object.oid);
1191
1192         if (object_on_skiplist(options, &blob->object))
1193                 return 0;
1194
1195         if (!buf) {
1196                 /*
1197                  * A missing buffer here is a sign that the caller found the
1198                  * blob too gigantic to load into memory. Let's just consider
1199                  * that an error.
1200                  */
1201                 return report(options, &blob->object,
1202                               FSCK_MSG_GITMODULES_LARGE,
1203                               ".gitmodules too large to parse");
1204         }
1205
1206         data.obj = &blob->object;
1207         data.options = options;
1208         data.ret = 0;
1209         config_opts.error_action = CONFIG_ERROR_SILENT;
1210         if (git_config_from_mem(fsck_gitmodules_fn, CONFIG_ORIGIN_BLOB,
1211                                 ".gitmodules", buf, size, &data, &config_opts))
1212                 data.ret |= report(options, &blob->object,
1213                                    FSCK_MSG_GITMODULES_PARSE,
1214                                    "could not parse gitmodules blob");
1215
1216         return data.ret;
1217 }
1218
1219 int fsck_object(struct object *obj, void *data, unsigned long size,
1220         struct fsck_options *options)
1221 {
1222         if (!obj)
1223                 return report(options, obj, FSCK_MSG_BAD_OBJECT_SHA1, "no valid object to fsck");
1224
1225         if (obj->type == OBJ_BLOB)
1226                 return fsck_blob((struct blob *)obj, data, size, options);
1227         if (obj->type == OBJ_TREE)
1228                 return fsck_tree((struct tree *) obj, options);
1229         if (obj->type == OBJ_COMMIT)
1230                 return fsck_commit((struct commit *) obj, (const char *) data,
1231                         size, options);
1232         if (obj->type == OBJ_TAG)
1233                 return fsck_tag((struct tag *) obj, (const char *) data,
1234                         size, options);
1235
1236         return report(options, obj, FSCK_MSG_UNKNOWN_TYPE, "unknown type '%d' (internal fsck error)",
1237                           obj->type);
1238 }
1239
1240 int fsck_error_function(struct fsck_options *o,
1241         struct object *obj, int msg_type, const char *message)
1242 {
1243         if (msg_type == FSCK_WARN) {
1244                 warning("object %s: %s", describe_object(o, obj), message);
1245                 return 0;
1246         }
1247         error("object %s: %s", describe_object(o, obj), message);
1248         return 1;
1249 }
1250
1251 int fsck_finish(struct fsck_options *options)
1252 {
1253         int ret = 0;
1254         struct oidset_iter iter;
1255         const struct object_id *oid;
1256
1257         oidset_iter_init(&gitmodules_found, &iter);
1258         while ((oid = oidset_iter_next(&iter))) {
1259                 struct blob *blob;
1260                 enum object_type type;
1261                 unsigned long size;
1262                 char *buf;
1263
1264                 if (oidset_contains(&gitmodules_done, oid))
1265                         continue;
1266
1267                 blob = lookup_blob(the_repository, oid);
1268                 if (!blob) {
1269                         struct object *obj = lookup_unknown_object(oid->hash);
1270                         ret |= report(options, obj,
1271                                       FSCK_MSG_GITMODULES_BLOB,
1272                                       "non-blob found at .gitmodules");
1273                         continue;
1274                 }
1275
1276                 buf = read_object_file(oid, &type, &size);
1277                 if (!buf) {
1278                         if (is_promisor_object(&blob->object.oid))
1279                                 continue;
1280                         ret |= report(options, &blob->object,
1281                                       FSCK_MSG_GITMODULES_MISSING,
1282                                       "unable to read .gitmodules blob");
1283                         continue;
1284                 }
1285
1286                 if (type == OBJ_BLOB)
1287                         ret |= fsck_blob(blob, buf, size, options);
1288                 else
1289                         ret |= report(options, &blob->object,
1290                                       FSCK_MSG_GITMODULES_BLOB,
1291                                       "non-blob found at .gitmodules");
1292                 free(buf);
1293         }
1294
1295
1296         oidset_clear(&gitmodules_found);
1297         oidset_clear(&gitmodules_done);
1298         return ret;
1299 }