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