Update callers of check_ref_format()
[git/git.git] / refs.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "tag.h"
5 #include "dir.h"
6
7 /* ISSYMREF=01 and ISPACKED=02 are public interfaces */
8 #define REF_KNOWS_PEELED 04
9
10 struct ref_list {
11 struct ref_list *next;
12 unsigned char flag; /* ISSYMREF? ISPACKED? */
13 unsigned char sha1[20];
14 unsigned char peeled[20];
15 char name[FLEX_ARRAY];
16 };
17
18 static const char *parse_ref_line(char *line, unsigned char *sha1)
19 {
20 /*
21 * 42: the answer to everything.
22 *
23 * In this case, it happens to be the answer to
24 * 40 (length of sha1 hex representation)
25 * +1 (space in between hex and name)
26 * +1 (newline at the end of the line)
27 */
28 int len = strlen(line) - 42;
29
30 if (len <= 0)
31 return NULL;
32 if (get_sha1_hex(line, sha1) < 0)
33 return NULL;
34 if (!isspace(line[40]))
35 return NULL;
36 line += 41;
37 if (isspace(*line))
38 return NULL;
39 if (line[len] != '\n')
40 return NULL;
41 line[len] = 0;
42
43 return line;
44 }
45
46 static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
47 int flag, struct ref_list *list,
48 struct ref_list **new_entry)
49 {
50 int len;
51 struct ref_list *entry;
52
53 /* Allocate it and add it in.. */
54 len = strlen(name) + 1;
55 entry = xmalloc(sizeof(struct ref_list) + len);
56 hashcpy(entry->sha1, sha1);
57 hashclr(entry->peeled);
58 memcpy(entry->name, name, len);
59 entry->flag = flag;
60 entry->next = list;
61 if (new_entry)
62 *new_entry = entry;
63 return entry;
64 }
65
66 /* merge sort the ref list */
67 static struct ref_list *sort_ref_list(struct ref_list *list)
68 {
69 int psize, qsize, last_merge_count, cmp;
70 struct ref_list *p, *q, *l, *e;
71 struct ref_list *new_list = list;
72 int k = 1;
73 int merge_count = 0;
74
75 if (!list)
76 return list;
77
78 do {
79 last_merge_count = merge_count;
80 merge_count = 0;
81
82 psize = 0;
83
84 p = new_list;
85 q = new_list;
86 new_list = NULL;
87 l = NULL;
88
89 while (p) {
90 merge_count++;
91
92 while (psize < k && q->next) {
93 q = q->next;
94 psize++;
95 }
96 qsize = k;
97
98 while ((psize > 0) || (qsize > 0 && q)) {
99 if (qsize == 0 || !q) {
100 e = p;
101 p = p->next;
102 psize--;
103 } else if (psize == 0) {
104 e = q;
105 q = q->next;
106 qsize--;
107 } else {
108 cmp = strcmp(q->name, p->name);
109 if (cmp < 0) {
110 e = q;
111 q = q->next;
112 qsize--;
113 } else if (cmp > 0) {
114 e = p;
115 p = p->next;
116 psize--;
117 } else {
118 if (hashcmp(q->sha1, p->sha1))
119 die("Duplicated ref, and SHA1s don't match: %s",
120 q->name);
121 warning("Duplicated ref: %s", q->name);
122 e = q;
123 q = q->next;
124 qsize--;
125 free(e);
126 e = p;
127 p = p->next;
128 psize--;
129 }
130 }
131
132 e->next = NULL;
133
134 if (l)
135 l->next = e;
136 if (!new_list)
137 new_list = e;
138 l = e;
139 }
140
141 p = q;
142 };
143
144 k = k * 2;
145 } while ((last_merge_count != merge_count) || (last_merge_count != 1));
146
147 return new_list;
148 }
149
150 /*
151 * Future: need to be in "struct repository"
152 * when doing a full libification.
153 */
154 static struct cached_refs {
155 char did_loose;
156 char did_packed;
157 struct ref_list *loose;
158 struct ref_list *packed;
159 } cached_refs;
160
161 static void free_ref_list(struct ref_list *list)
162 {
163 struct ref_list *next;
164 for ( ; list; list = next) {
165 next = list->next;
166 free(list);
167 }
168 }
169
170 static void invalidate_cached_refs(void)
171 {
172 struct cached_refs *ca = &cached_refs;
173
174 if (ca->did_loose && ca->loose)
175 free_ref_list(ca->loose);
176 if (ca->did_packed && ca->packed)
177 free_ref_list(ca->packed);
178 ca->loose = ca->packed = NULL;
179 ca->did_loose = ca->did_packed = 0;
180 }
181
182 static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
183 {
184 struct ref_list *list = NULL;
185 struct ref_list *last = NULL;
186 char refline[PATH_MAX];
187 int flag = REF_ISPACKED;
188
189 while (fgets(refline, sizeof(refline), f)) {
190 unsigned char sha1[20];
191 const char *name;
192 static const char header[] = "# pack-refs with:";
193
194 if (!strncmp(refline, header, sizeof(header)-1)) {
195 const char *traits = refline + sizeof(header) - 1;
196 if (strstr(traits, " peeled "))
197 flag |= REF_KNOWS_PEELED;
198 /* perhaps other traits later as well */
199 continue;
200 }
201
202 name = parse_ref_line(refline, sha1);
203 if (name) {
204 list = add_ref(name, sha1, flag, list, &last);
205 continue;
206 }
207 if (last &&
208 refline[0] == '^' &&
209 strlen(refline) == 42 &&
210 refline[41] == '\n' &&
211 !get_sha1_hex(refline + 1, sha1))
212 hashcpy(last->peeled, sha1);
213 }
214 cached_refs->packed = sort_ref_list(list);
215 }
216
217 static struct ref_list *get_packed_refs(void)
218 {
219 if (!cached_refs.did_packed) {
220 FILE *f = fopen(git_path("packed-refs"), "r");
221 cached_refs.packed = NULL;
222 if (f) {
223 read_packed_refs(f, &cached_refs);
224 fclose(f);
225 }
226 cached_refs.did_packed = 1;
227 }
228 return cached_refs.packed;
229 }
230
231 static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
232 {
233 DIR *dir = opendir(git_path("%s", base));
234
235 if (dir) {
236 struct dirent *de;
237 int baselen = strlen(base);
238 char *ref = xmalloc(baselen + 257);
239
240 memcpy(ref, base, baselen);
241 if (baselen && base[baselen-1] != '/')
242 ref[baselen++] = '/';
243
244 while ((de = readdir(dir)) != NULL) {
245 unsigned char sha1[20];
246 struct stat st;
247 int flag;
248 int namelen;
249
250 if (de->d_name[0] == '.')
251 continue;
252 namelen = strlen(de->d_name);
253 if (namelen > 255)
254 continue;
255 if (has_extension(de->d_name, ".lock"))
256 continue;
257 memcpy(ref + baselen, de->d_name, namelen+1);
258 if (stat(git_path("%s", ref), &st) < 0)
259 continue;
260 if (S_ISDIR(st.st_mode)) {
261 list = get_ref_dir(ref, list);
262 continue;
263 }
264 if (!resolve_ref(ref, sha1, 1, &flag)) {
265 error("%s points nowhere!", ref);
266 continue;
267 }
268 list = add_ref(ref, sha1, flag, list, NULL);
269 }
270 free(ref);
271 closedir(dir);
272 }
273 return sort_ref_list(list);
274 }
275
276 static struct ref_list *get_loose_refs(void)
277 {
278 if (!cached_refs.did_loose) {
279 cached_refs.loose = get_ref_dir("refs", NULL);
280 cached_refs.did_loose = 1;
281 }
282 return cached_refs.loose;
283 }
284
285 /* We allow "recursive" symbolic refs. Only within reason, though */
286 #define MAXDEPTH 5
287 #define MAXREFLEN (1024)
288
289 static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
290 {
291 FILE *f;
292 struct cached_refs refs;
293 struct ref_list *ref;
294 int retval;
295
296 strcpy(name + pathlen, "packed-refs");
297 f = fopen(name, "r");
298 if (!f)
299 return -1;
300 read_packed_refs(f, &refs);
301 fclose(f);
302 ref = refs.packed;
303 retval = -1;
304 while (ref) {
305 if (!strcmp(ref->name, refname)) {
306 retval = 0;
307 memcpy(result, ref->sha1, 20);
308 break;
309 }
310 ref = ref->next;
311 }
312 free_ref_list(refs.packed);
313 return retval;
314 }
315
316 static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
317 {
318 int fd, len = strlen(refname);
319 char buffer[128], *p;
320
321 if (recursion > MAXDEPTH || len > MAXREFLEN)
322 return -1;
323 memcpy(name + pathlen, refname, len+1);
324 fd = open(name, O_RDONLY);
325 if (fd < 0)
326 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
327
328 len = read(fd, buffer, sizeof(buffer)-1);
329 close(fd);
330 if (len < 0)
331 return -1;
332 while (len && isspace(buffer[len-1]))
333 len--;
334 buffer[len] = 0;
335
336 /* Was it a detached head or an old-fashioned symlink? */
337 if (!get_sha1_hex(buffer, result))
338 return 0;
339
340 /* Symref? */
341 if (strncmp(buffer, "ref:", 4))
342 return -1;
343 p = buffer + 4;
344 while (isspace(*p))
345 p++;
346
347 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
348 }
349
350 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
351 {
352 int len = strlen(path), retval;
353 char *gitdir;
354
355 while (len && path[len-1] == '/')
356 len--;
357 if (!len)
358 return -1;
359 gitdir = xmalloc(len + MAXREFLEN + 8);
360 memcpy(gitdir, path, len);
361 memcpy(gitdir + len, "/.git/", 7);
362
363 retval = resolve_gitlink_ref_recursive(gitdir, len+6, refname, result, 0);
364 free(gitdir);
365 return retval;
366 }
367
368 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
369 {
370 int depth = MAXDEPTH, len;
371 char buffer[256];
372 static char ref_buffer[256];
373
374 if (flag)
375 *flag = 0;
376
377 for (;;) {
378 const char *path = git_path("%s", ref);
379 struct stat st;
380 char *buf;
381 int fd;
382
383 if (--depth < 0)
384 return NULL;
385
386 /* Special case: non-existing file.
387 * Not having the refs/heads/new-branch is OK
388 * if we are writing into it, so is .git/HEAD
389 * that points at refs/heads/master still to be
390 * born. It is NOT OK if we are resolving for
391 * reading.
392 */
393 if (lstat(path, &st) < 0) {
394 struct ref_list *list = get_packed_refs();
395 while (list) {
396 if (!strcmp(ref, list->name)) {
397 hashcpy(sha1, list->sha1);
398 if (flag)
399 *flag |= REF_ISPACKED;
400 return ref;
401 }
402 list = list->next;
403 }
404 if (reading || errno != ENOENT)
405 return NULL;
406 hashclr(sha1);
407 return ref;
408 }
409
410 /* Follow "normalized" - ie "refs/.." symlinks by hand */
411 if (S_ISLNK(st.st_mode)) {
412 len = readlink(path, buffer, sizeof(buffer)-1);
413 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
414 buffer[len] = 0;
415 strcpy(ref_buffer, buffer);
416 ref = ref_buffer;
417 if (flag)
418 *flag |= REF_ISSYMREF;
419 continue;
420 }
421 }
422
423 /* Is it a directory? */
424 if (S_ISDIR(st.st_mode)) {
425 errno = EISDIR;
426 return NULL;
427 }
428
429 /*
430 * Anything else, just open it and try to use it as
431 * a ref
432 */
433 fd = open(path, O_RDONLY);
434 if (fd < 0)
435 return NULL;
436 len = read_in_full(fd, buffer, sizeof(buffer)-1);
437 close(fd);
438
439 /*
440 * Is it a symbolic ref?
441 */
442 if (len < 4 || memcmp("ref:", buffer, 4))
443 break;
444 buf = buffer + 4;
445 len -= 4;
446 while (len && isspace(*buf))
447 buf++, len--;
448 while (len && isspace(buf[len-1]))
449 len--;
450 buf[len] = 0;
451 memcpy(ref_buffer, buf, len + 1);
452 ref = ref_buffer;
453 if (flag)
454 *flag |= REF_ISSYMREF;
455 }
456 if (len < 40 || get_sha1_hex(buffer, sha1))
457 return NULL;
458 return ref;
459 }
460
461 int read_ref(const char *ref, unsigned char *sha1)
462 {
463 if (resolve_ref(ref, sha1, 1, NULL))
464 return 0;
465 return -1;
466 }
467
468 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
469 void *cb_data, struct ref_list *entry)
470 {
471 if (strncmp(base, entry->name, trim))
472 return 0;
473 if (is_null_sha1(entry->sha1))
474 return 0;
475 if (!has_sha1_file(entry->sha1)) {
476 error("%s does not point to a valid object!", entry->name);
477 return 0;
478 }
479 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
480 }
481
482 int peel_ref(const char *ref, unsigned char *sha1)
483 {
484 int flag;
485 unsigned char base[20];
486 struct object *o;
487
488 if (!resolve_ref(ref, base, 1, &flag))
489 return -1;
490
491 if ((flag & REF_ISPACKED)) {
492 struct ref_list *list = get_packed_refs();
493
494 while (list) {
495 if (!strcmp(list->name, ref)) {
496 if (list->flag & REF_KNOWS_PEELED) {
497 hashcpy(sha1, list->peeled);
498 return 0;
499 }
500 /* older pack-refs did not leave peeled ones */
501 break;
502 }
503 list = list->next;
504 }
505 }
506
507 /* fallback - callers should not call this for unpacked refs */
508 o = parse_object(base);
509 if (o->type == OBJ_TAG) {
510 o = deref_tag(o, ref, 0);
511 if (o) {
512 hashcpy(sha1, o->sha1);
513 return 0;
514 }
515 }
516 return -1;
517 }
518
519 static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
520 void *cb_data)
521 {
522 int retval;
523 struct ref_list *packed = get_packed_refs();
524 struct ref_list *loose = get_loose_refs();
525
526 while (packed && loose) {
527 struct ref_list *entry;
528 int cmp = strcmp(packed->name, loose->name);
529 if (!cmp) {
530 packed = packed->next;
531 continue;
532 }
533 if (cmp > 0) {
534 entry = loose;
535 loose = loose->next;
536 } else {
537 entry = packed;
538 packed = packed->next;
539 }
540 retval = do_one_ref(base, fn, trim, cb_data, entry);
541 if (retval)
542 return retval;
543 }
544
545 for (packed = packed ? packed : loose; packed; packed = packed->next) {
546 retval = do_one_ref(base, fn, trim, cb_data, packed);
547 if (retval)
548 return retval;
549 }
550 return 0;
551 }
552
553 int head_ref(each_ref_fn fn, void *cb_data)
554 {
555 unsigned char sha1[20];
556 int flag;
557
558 if (resolve_ref("HEAD", sha1, 1, &flag))
559 return fn("HEAD", sha1, flag, cb_data);
560 return 0;
561 }
562
563 int for_each_ref(each_ref_fn fn, void *cb_data)
564 {
565 return do_for_each_ref("refs/", fn, 0, cb_data);
566 }
567
568 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
569 {
570 return do_for_each_ref("refs/tags/", fn, 10, cb_data);
571 }
572
573 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
574 {
575 return do_for_each_ref("refs/heads/", fn, 11, cb_data);
576 }
577
578 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
579 {
580 return do_for_each_ref("refs/remotes/", fn, 13, cb_data);
581 }
582
583 /*
584 * Make sure "ref" is something reasonable to have under ".git/refs/";
585 * We do not like it if:
586 *
587 * - any path component of it begins with ".", or
588 * - it has double dots "..", or
589 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
590 * - it ends with a "/".
591 */
592
593 static inline int bad_ref_char(int ch)
594 {
595 if (((unsigned) ch) <= ' ' ||
596 ch == '~' || ch == '^' || ch == ':')
597 return 1;
598 /* 2.13 Pattern Matching Notation */
599 if (ch == '?' || ch == '[') /* Unsupported */
600 return 1;
601 if (ch == '*') /* Supported at the end */
602 return 2;
603 return 0;
604 }
605
606 int check_ref_format(const char *ref)
607 {
608 int ch, level, bad_type;
609 const char *cp = ref;
610
611 level = 0;
612 while (1) {
613 while ((ch = *cp++) == '/')
614 ; /* tolerate duplicated slashes */
615 if (!ch)
616 /* should not end with slashes */
617 return CHECK_REF_FORMAT_ERROR;
618
619 /* we are at the beginning of the path component */
620 if (ch == '.')
621 return CHECK_REF_FORMAT_ERROR;
622 bad_type = bad_ref_char(ch);
623 if (bad_type) {
624 return (bad_type == 2 && !*cp)
625 ? CHECK_REF_FORMAT_WILDCARD
626 : CHECK_REF_FORMAT_ERROR;
627 }
628
629 /* scan the rest of the path component */
630 while ((ch = *cp++) != 0) {
631 bad_type = bad_ref_char(ch);
632 if (bad_type) {
633 return (bad_type == 2 && !*cp)
634 ? CHECK_REF_FORMAT_WILDCARD
635 : CHECK_REF_FORMAT_ERROR;
636 }
637 if (ch == '/')
638 break;
639 if (ch == '.' && *cp == '.')
640 return CHECK_REF_FORMAT_ERROR;
641 }
642 level++;
643 if (!ch) {
644 if (level < 2)
645 return CHECK_REF_FORMAT_ONELEVEL;
646 return CHECK_REF_FORMAT_OK;
647 }
648 }
649 }
650
651 const char *ref_rev_parse_rules[] = {
652 "%.*s",
653 "refs/%.*s",
654 "refs/tags/%.*s",
655 "refs/heads/%.*s",
656 "refs/remotes/%.*s",
657 "refs/remotes/%.*s/HEAD",
658 NULL
659 };
660
661 const char *ref_fetch_rules[] = {
662 "%.*s",
663 "refs/%.*s",
664 "refs/heads/%.*s",
665 NULL
666 };
667
668 int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
669 {
670 const char **p;
671 const int abbrev_name_len = strlen(abbrev_name);
672
673 for (p = rules; *p; p++) {
674 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
675 return 1;
676 }
677 }
678
679 return 0;
680 }
681
682 static struct ref_lock *verify_lock(struct ref_lock *lock,
683 const unsigned char *old_sha1, int mustexist)
684 {
685 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
686 error("Can't verify ref %s", lock->ref_name);
687 unlock_ref(lock);
688 return NULL;
689 }
690 if (hashcmp(lock->old_sha1, old_sha1)) {
691 error("Ref %s is at %s but expected %s", lock->ref_name,
692 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
693 unlock_ref(lock);
694 return NULL;
695 }
696 return lock;
697 }
698
699 static int remove_empty_directories(const char *file)
700 {
701 /* we want to create a file but there is a directory there;
702 * if that is an empty directory (or a directory that contains
703 * only empty directories), remove them.
704 */
705 struct strbuf path;
706 int result;
707
708 strbuf_init(&path, 20);
709 strbuf_addstr(&path, file);
710
711 result = remove_dir_recursively(&path, 1);
712
713 strbuf_release(&path);
714
715 return result;
716 }
717
718 static int is_refname_available(const char *ref, const char *oldref,
719 struct ref_list *list, int quiet)
720 {
721 int namlen = strlen(ref); /* e.g. 'foo/bar' */
722 while (list) {
723 /* list->name could be 'foo' or 'foo/bar/baz' */
724 if (!oldref || strcmp(oldref, list->name)) {
725 int len = strlen(list->name);
726 int cmplen = (namlen < len) ? namlen : len;
727 const char *lead = (namlen < len) ? list->name : ref;
728 if (!strncmp(ref, list->name, cmplen) &&
729 lead[cmplen] == '/') {
730 if (!quiet)
731 error("'%s' exists; cannot create '%s'",
732 list->name, ref);
733 return 0;
734 }
735 }
736 list = list->next;
737 }
738 return 1;
739 }
740
741 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
742 {
743 char *ref_file;
744 const char *orig_ref = ref;
745 struct ref_lock *lock;
746 struct stat st;
747 int last_errno = 0;
748 int type;
749 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
750
751 lock = xcalloc(1, sizeof(struct ref_lock));
752 lock->lock_fd = -1;
753
754 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
755 if (!ref && errno == EISDIR) {
756 /* we are trying to lock foo but we used to
757 * have foo/bar which now does not exist;
758 * it is normal for the empty directory 'foo'
759 * to remain.
760 */
761 ref_file = git_path("%s", orig_ref);
762 if (remove_empty_directories(ref_file)) {
763 last_errno = errno;
764 error("there are still refs under '%s'", orig_ref);
765 goto error_return;
766 }
767 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
768 }
769 if (type_p)
770 *type_p = type;
771 if (!ref) {
772 last_errno = errno;
773 error("unable to resolve reference %s: %s",
774 orig_ref, strerror(errno));
775 goto error_return;
776 }
777 /* When the ref did not exist and we are creating it,
778 * make sure there is no existing ref that is packed
779 * whose name begins with our refname, nor a ref whose
780 * name is a proper prefix of our refname.
781 */
782 if (is_null_sha1(lock->old_sha1) &&
783 !is_refname_available(ref, NULL, get_packed_refs(), 0))
784 goto error_return;
785
786 lock->lk = xcalloc(1, sizeof(struct lock_file));
787
788 if (flags & REF_NODEREF)
789 ref = orig_ref;
790 lock->ref_name = xstrdup(ref);
791 lock->orig_ref_name = xstrdup(orig_ref);
792 ref_file = git_path("%s", ref);
793 if (lstat(ref_file, &st) && errno == ENOENT)
794 lock->force_write = 1;
795 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
796 lock->force_write = 1;
797
798 if (safe_create_leading_directories(ref_file)) {
799 last_errno = errno;
800 error("unable to create directory for %s", ref_file);
801 goto error_return;
802 }
803 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
804
805 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
806
807 error_return:
808 unlock_ref(lock);
809 errno = last_errno;
810 return NULL;
811 }
812
813 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
814 {
815 char refpath[PATH_MAX];
816 if (check_ref_format(ref))
817 return NULL;
818 strcpy(refpath, mkpath("refs/%s", ref));
819 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
820 }
821
822 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
823 {
824 switch (check_ref_format(ref)) {
825 default:
826 return NULL;
827 case 0:
828 case CHECK_REF_FORMAT_ONELEVEL:
829 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
830 }
831 }
832
833 static struct lock_file packlock;
834
835 static int repack_without_ref(const char *refname)
836 {
837 struct ref_list *list, *packed_ref_list;
838 int fd;
839 int found = 0;
840
841 packed_ref_list = get_packed_refs();
842 for (list = packed_ref_list; list; list = list->next) {
843 if (!strcmp(refname, list->name)) {
844 found = 1;
845 break;
846 }
847 }
848 if (!found)
849 return 0;
850 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
851 if (fd < 0)
852 return error("cannot delete '%s' from packed refs", refname);
853
854 for (list = packed_ref_list; list; list = list->next) {
855 char line[PATH_MAX + 100];
856 int len;
857
858 if (!strcmp(refname, list->name))
859 continue;
860 len = snprintf(line, sizeof(line), "%s %s\n",
861 sha1_to_hex(list->sha1), list->name);
862 /* this should not happen but just being defensive */
863 if (len > sizeof(line))
864 die("too long a refname '%s'", list->name);
865 write_or_die(fd, line, len);
866 }
867 close(fd);
868 return commit_lock_file(&packlock);
869 }
870
871 int delete_ref(const char *refname, const unsigned char *sha1)
872 {
873 struct ref_lock *lock;
874 int err, i, ret = 0, flag = 0;
875
876 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
877 if (!lock)
878 return 1;
879 if (!(flag & REF_ISPACKED)) {
880 /* loose */
881 i = strlen(lock->lk->filename) - 5; /* .lock */
882 lock->lk->filename[i] = 0;
883 err = unlink(lock->lk->filename);
884 if (err) {
885 ret = 1;
886 error("unlink(%s) failed: %s",
887 lock->lk->filename, strerror(errno));
888 }
889 lock->lk->filename[i] = '.';
890 }
891 /* removing the loose one could have resurrected an earlier
892 * packed one. Also, if it was not loose we need to repack
893 * without it.
894 */
895 ret |= repack_without_ref(refname);
896
897 err = unlink(git_path("logs/%s", lock->ref_name));
898 if (err && errno != ENOENT)
899 fprintf(stderr, "warning: unlink(%s) failed: %s",
900 git_path("logs/%s", lock->ref_name), strerror(errno));
901 invalidate_cached_refs();
902 unlock_ref(lock);
903 return ret;
904 }
905
906 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
907 {
908 static const char renamed_ref[] = "RENAMED-REF";
909 unsigned char sha1[20], orig_sha1[20];
910 int flag = 0, logmoved = 0;
911 struct ref_lock *lock;
912 struct stat loginfo;
913 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
914
915 if (S_ISLNK(loginfo.st_mode))
916 return error("reflog for %s is a symlink", oldref);
917
918 if (!resolve_ref(oldref, orig_sha1, 1, &flag))
919 return error("refname %s not found", oldref);
920
921 if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
922 return 1;
923
924 if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
925 return 1;
926
927 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
928 if (!lock)
929 return error("unable to lock %s", renamed_ref);
930 lock->force_write = 1;
931 if (write_ref_sha1(lock, orig_sha1, logmsg))
932 return error("unable to save current sha1 in %s", renamed_ref);
933
934 if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
935 return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
936 oldref, strerror(errno));
937
938 if (delete_ref(oldref, orig_sha1)) {
939 error("unable to delete old %s", oldref);
940 goto rollback;
941 }
942
943 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1)) {
944 if (errno==EISDIR) {
945 if (remove_empty_directories(git_path("%s", newref))) {
946 error("Directory not empty: %s", newref);
947 goto rollback;
948 }
949 } else {
950 error("unable to delete existing %s", newref);
951 goto rollback;
952 }
953 }
954
955 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
956 error("unable to create directory for %s", newref);
957 goto rollback;
958 }
959
960 retry:
961 if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
962 if (errno==EISDIR || errno==ENOTDIR) {
963 /*
964 * rename(a, b) when b is an existing
965 * directory ought to result in ISDIR, but
966 * Solaris 5.8 gives ENOTDIR. Sheesh.
967 */
968 if (remove_empty_directories(git_path("logs/%s", newref))) {
969 error("Directory not empty: logs/%s", newref);
970 goto rollback;
971 }
972 goto retry;
973 } else {
974 error("unable to move logfile tmp-renamed-log to logs/%s: %s",
975 newref, strerror(errno));
976 goto rollback;
977 }
978 }
979 logmoved = log;
980
981 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
982 if (!lock) {
983 error("unable to lock %s for update", newref);
984 goto rollback;
985 }
986
987 lock->force_write = 1;
988 hashcpy(lock->old_sha1, orig_sha1);
989 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
990 error("unable to write current sha1 into %s", newref);
991 goto rollback;
992 }
993
994 return 0;
995
996 rollback:
997 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
998 if (!lock) {
999 error("unable to lock %s for rollback", oldref);
1000 goto rollbacklog;
1001 }
1002
1003 lock->force_write = 1;
1004 flag = log_all_ref_updates;
1005 log_all_ref_updates = 0;
1006 if (write_ref_sha1(lock, orig_sha1, NULL))
1007 error("unable to write current sha1 into %s", oldref);
1008 log_all_ref_updates = flag;
1009
1010 rollbacklog:
1011 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1012 error("unable to restore logfile %s from %s: %s",
1013 oldref, newref, strerror(errno));
1014 if (!logmoved && log &&
1015 rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
1016 error("unable to restore logfile %s from tmp-renamed-log: %s",
1017 oldref, strerror(errno));
1018
1019 return 1;
1020 }
1021
1022 void unlock_ref(struct ref_lock *lock)
1023 {
1024 if (lock->lock_fd >= 0) {
1025 close(lock->lock_fd);
1026 /* Do not free lock->lk -- atexit() still looks at them */
1027 if (lock->lk)
1028 rollback_lock_file(lock->lk);
1029 }
1030 free(lock->ref_name);
1031 free(lock->orig_ref_name);
1032 free(lock);
1033 }
1034
1035 /*
1036 * copy the reflog message msg to buf, which has been allocated sufficiently
1037 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1038 * because reflog file is one line per entry.
1039 */
1040 static int copy_msg(char *buf, const char *msg)
1041 {
1042 char *cp = buf;
1043 char c;
1044 int wasspace = 1;
1045
1046 *cp++ = '\t';
1047 while ((c = *msg++)) {
1048 if (wasspace && isspace(c))
1049 continue;
1050 wasspace = isspace(c);
1051 if (wasspace)
1052 c = ' ';
1053 *cp++ = c;
1054 }
1055 while (buf < cp && isspace(cp[-1]))
1056 cp--;
1057 *cp++ = '\n';
1058 return cp - buf;
1059 }
1060
1061 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1062 const unsigned char *new_sha1, const char *msg)
1063 {
1064 int logfd, written, oflags = O_APPEND | O_WRONLY;
1065 unsigned maxlen, len;
1066 int msglen;
1067 char *log_file, *logrec;
1068 const char *committer;
1069
1070 if (log_all_ref_updates < 0)
1071 log_all_ref_updates = !is_bare_repository();
1072
1073 log_file = git_path("logs/%s", ref_name);
1074
1075 if (log_all_ref_updates &&
1076 (!prefixcmp(ref_name, "refs/heads/") ||
1077 !prefixcmp(ref_name, "refs/remotes/") ||
1078 !strcmp(ref_name, "HEAD"))) {
1079 if (safe_create_leading_directories(log_file) < 0)
1080 return error("unable to create directory for %s",
1081 log_file);
1082 oflags |= O_CREAT;
1083 }
1084
1085 logfd = open(log_file, oflags, 0666);
1086 if (logfd < 0) {
1087 if (!(oflags & O_CREAT) && errno == ENOENT)
1088 return 0;
1089
1090 if ((oflags & O_CREAT) && errno == EISDIR) {
1091 if (remove_empty_directories(log_file)) {
1092 return error("There are still logs under '%s'",
1093 log_file);
1094 }
1095 logfd = open(log_file, oflags, 0666);
1096 }
1097
1098 if (logfd < 0)
1099 return error("Unable to append to %s: %s",
1100 log_file, strerror(errno));
1101 }
1102
1103 adjust_shared_perm(log_file);
1104
1105 msglen = msg ? strlen(msg) : 0;
1106 committer = git_committer_info(0);
1107 maxlen = strlen(committer) + msglen + 100;
1108 logrec = xmalloc(maxlen);
1109 len = sprintf(logrec, "%s %s %s\n",
1110 sha1_to_hex(old_sha1),
1111 sha1_to_hex(new_sha1),
1112 committer);
1113 if (msglen)
1114 len += copy_msg(logrec + len - 1, msg) - 1;
1115 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1116 free(logrec);
1117 if (close(logfd) != 0 || written != len)
1118 return error("Unable to append to %s", log_file);
1119 return 0;
1120 }
1121
1122 int write_ref_sha1(struct ref_lock *lock,
1123 const unsigned char *sha1, const char *logmsg)
1124 {
1125 static char term = '\n';
1126
1127 if (!lock)
1128 return -1;
1129 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1130 unlock_ref(lock);
1131 return 0;
1132 }
1133 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1134 write_in_full(lock->lock_fd, &term, 1) != 1
1135 || close(lock->lock_fd) < 0) {
1136 error("Couldn't write %s", lock->lk->filename);
1137 unlock_ref(lock);
1138 return -1;
1139 }
1140 invalidate_cached_refs();
1141 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1142 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1143 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1144 unlock_ref(lock);
1145 return -1;
1146 }
1147 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1148 /*
1149 * Special hack: If a branch is updated directly and HEAD
1150 * points to it (may happen on the remote side of a push
1151 * for example) then logically the HEAD reflog should be
1152 * updated too.
1153 * A generic solution implies reverse symref information,
1154 * but finding all symrefs pointing to the given branch
1155 * would be rather costly for this rare event (the direct
1156 * update of a branch) to be worth it. So let's cheat and
1157 * check with HEAD only which should cover 99% of all usage
1158 * scenarios (even 100% of the default ones).
1159 */
1160 unsigned char head_sha1[20];
1161 int head_flag;
1162 const char *head_ref;
1163 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1164 if (head_ref && (head_flag & REF_ISSYMREF) &&
1165 !strcmp(head_ref, lock->ref_name))
1166 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1167 }
1168 if (commit_lock_file(lock->lk)) {
1169 error("Couldn't set %s", lock->ref_name);
1170 unlock_ref(lock);
1171 return -1;
1172 }
1173 lock->lock_fd = -1;
1174 unlock_ref(lock);
1175 return 0;
1176 }
1177
1178 int create_symref(const char *ref_target, const char *refs_heads_master,
1179 const char *logmsg)
1180 {
1181 const char *lockpath;
1182 char ref[1000];
1183 int fd, len, written;
1184 char *git_HEAD = xstrdup(git_path("%s", ref_target));
1185 unsigned char old_sha1[20], new_sha1[20];
1186
1187 if (logmsg && read_ref(ref_target, old_sha1))
1188 hashclr(old_sha1);
1189
1190 if (safe_create_leading_directories(git_HEAD) < 0)
1191 return error("unable to create directory for %s", git_HEAD);
1192
1193 #ifndef NO_SYMLINK_HEAD
1194 if (prefer_symlink_refs) {
1195 unlink(git_HEAD);
1196 if (!symlink(refs_heads_master, git_HEAD))
1197 goto done;
1198 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1199 }
1200 #endif
1201
1202 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1203 if (sizeof(ref) <= len) {
1204 error("refname too long: %s", refs_heads_master);
1205 goto error_free_return;
1206 }
1207 lockpath = mkpath("%s.lock", git_HEAD);
1208 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1209 if (fd < 0) {
1210 error("Unable to open %s for writing", lockpath);
1211 goto error_free_return;
1212 }
1213 written = write_in_full(fd, ref, len);
1214 if (close(fd) != 0 || written != len) {
1215 error("Unable to write to %s", lockpath);
1216 goto error_unlink_return;
1217 }
1218 if (rename(lockpath, git_HEAD) < 0) {
1219 error("Unable to create %s", git_HEAD);
1220 goto error_unlink_return;
1221 }
1222 if (adjust_shared_perm(git_HEAD)) {
1223 error("Unable to fix permissions on %s", lockpath);
1224 error_unlink_return:
1225 unlink(lockpath);
1226 error_free_return:
1227 free(git_HEAD);
1228 return -1;
1229 }
1230
1231 #ifndef NO_SYMLINK_HEAD
1232 done:
1233 #endif
1234 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1235 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1236
1237 free(git_HEAD);
1238 return 0;
1239 }
1240
1241 static char *ref_msg(const char *line, const char *endp)
1242 {
1243 const char *ep;
1244 line += 82;
1245 ep = memchr(line, '\n', endp - line);
1246 if (!ep)
1247 ep = endp;
1248 return xmemdupz(line, ep - line);
1249 }
1250
1251 int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned char *sha1, char **msg, unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
1252 {
1253 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1254 char *tz_c;
1255 int logfd, tz, reccnt = 0;
1256 struct stat st;
1257 unsigned long date;
1258 unsigned char logged_sha1[20];
1259 void *log_mapped;
1260 size_t mapsz;
1261
1262 logfile = git_path("logs/%s", ref);
1263 logfd = open(logfile, O_RDONLY, 0);
1264 if (logfd < 0)
1265 die("Unable to read log %s: %s", logfile, strerror(errno));
1266 fstat(logfd, &st);
1267 if (!st.st_size)
1268 die("Log %s is empty.", logfile);
1269 mapsz = xsize_t(st.st_size);
1270 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1271 logdata = log_mapped;
1272 close(logfd);
1273
1274 lastrec = NULL;
1275 rec = logend = logdata + st.st_size;
1276 while (logdata < rec) {
1277 reccnt++;
1278 if (logdata < rec && *(rec-1) == '\n')
1279 rec--;
1280 lastgt = NULL;
1281 while (logdata < rec && *(rec-1) != '\n') {
1282 rec--;
1283 if (*rec == '>')
1284 lastgt = rec;
1285 }
1286 if (!lastgt)
1287 die("Log %s is corrupt.", logfile);
1288 date = strtoul(lastgt + 1, &tz_c, 10);
1289 if (date <= at_time || cnt == 0) {
1290 tz = strtoul(tz_c, NULL, 10);
1291 if (msg)
1292 *msg = ref_msg(rec, logend);
1293 if (cutoff_time)
1294 *cutoff_time = date;
1295 if (cutoff_tz)
1296 *cutoff_tz = tz;
1297 if (cutoff_cnt)
1298 *cutoff_cnt = reccnt - 1;
1299 if (lastrec) {
1300 if (get_sha1_hex(lastrec, logged_sha1))
1301 die("Log %s is corrupt.", logfile);
1302 if (get_sha1_hex(rec + 41, sha1))
1303 die("Log %s is corrupt.", logfile);
1304 if (hashcmp(logged_sha1, sha1)) {
1305 fprintf(stderr,
1306 "warning: Log %s has gap after %s.\n",
1307 logfile, show_date(date, tz, DATE_RFC2822));
1308 }
1309 }
1310 else if (date == at_time) {
1311 if (get_sha1_hex(rec + 41, sha1))
1312 die("Log %s is corrupt.", logfile);
1313 }
1314 else {
1315 if (get_sha1_hex(rec + 41, logged_sha1))
1316 die("Log %s is corrupt.", logfile);
1317 if (hashcmp(logged_sha1, sha1)) {
1318 fprintf(stderr,
1319 "warning: Log %s unexpectedly ended on %s.\n",
1320 logfile, show_date(date, tz, DATE_RFC2822));
1321 }
1322 }
1323 munmap(log_mapped, mapsz);
1324 return 0;
1325 }
1326 lastrec = rec;
1327 if (cnt > 0)
1328 cnt--;
1329 }
1330
1331 rec = logdata;
1332 while (rec < logend && *rec != '>' && *rec != '\n')
1333 rec++;
1334 if (rec == logend || *rec == '\n')
1335 die("Log %s is corrupt.", logfile);
1336 date = strtoul(rec + 1, &tz_c, 10);
1337 tz = strtoul(tz_c, NULL, 10);
1338 if (get_sha1_hex(logdata, sha1))
1339 die("Log %s is corrupt.", logfile);
1340 if (msg)
1341 *msg = ref_msg(logdata, logend);
1342 munmap(log_mapped, mapsz);
1343
1344 if (cutoff_time)
1345 *cutoff_time = date;
1346 if (cutoff_tz)
1347 *cutoff_tz = tz;
1348 if (cutoff_cnt)
1349 *cutoff_cnt = reccnt;
1350 return 1;
1351 }
1352
1353 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1354 {
1355 const char *logfile;
1356 FILE *logfp;
1357 char buf[1024];
1358 int ret = 0;
1359
1360 logfile = git_path("logs/%s", ref);
1361 logfp = fopen(logfile, "r");
1362 if (!logfp)
1363 return -1;
1364 while (fgets(buf, sizeof(buf), logfp)) {
1365 unsigned char osha1[20], nsha1[20];
1366 char *email_end, *message;
1367 unsigned long timestamp;
1368 int len, tz;
1369
1370 /* old SP new SP name <email> SP time TAB msg LF */
1371 len = strlen(buf);
1372 if (len < 83 || buf[len-1] != '\n' ||
1373 get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
1374 get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
1375 !(email_end = strchr(buf + 82, '>')) ||
1376 email_end[1] != ' ' ||
1377 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1378 !message || message[0] != ' ' ||
1379 (message[1] != '+' && message[1] != '-') ||
1380 !isdigit(message[2]) || !isdigit(message[3]) ||
1381 !isdigit(message[4]) || !isdigit(message[5]))
1382 continue; /* corrupt? */
1383 email_end[1] = '\0';
1384 tz = strtol(message + 1, NULL, 10);
1385 if (message[6] != '\t')
1386 message += 6;
1387 else
1388 message += 7;
1389 ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
1390 if (ret)
1391 break;
1392 }
1393 fclose(logfp);
1394 return ret;
1395 }
1396
1397 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1398 {
1399 DIR *dir = opendir(git_path("logs/%s", base));
1400 int retval = 0;
1401
1402 if (dir) {
1403 struct dirent *de;
1404 int baselen = strlen(base);
1405 char *log = xmalloc(baselen + 257);
1406
1407 memcpy(log, base, baselen);
1408 if (baselen && base[baselen-1] != '/')
1409 log[baselen++] = '/';
1410
1411 while ((de = readdir(dir)) != NULL) {
1412 struct stat st;
1413 int namelen;
1414
1415 if (de->d_name[0] == '.')
1416 continue;
1417 namelen = strlen(de->d_name);
1418 if (namelen > 255)
1419 continue;
1420 if (has_extension(de->d_name, ".lock"))
1421 continue;
1422 memcpy(log + baselen, de->d_name, namelen+1);
1423 if (stat(git_path("logs/%s", log), &st) < 0)
1424 continue;
1425 if (S_ISDIR(st.st_mode)) {
1426 retval = do_for_each_reflog(log, fn, cb_data);
1427 } else {
1428 unsigned char sha1[20];
1429 if (!resolve_ref(log, sha1, 0, NULL))
1430 retval = error("bad ref for %s", log);
1431 else
1432 retval = fn(log, sha1, 0, cb_data);
1433 }
1434 if (retval)
1435 break;
1436 }
1437 free(log);
1438 closedir(dir);
1439 }
1440 else if (*base)
1441 return errno;
1442 return retval;
1443 }
1444
1445 int for_each_reflog(each_ref_fn fn, void *cb_data)
1446 {
1447 return do_for_each_reflog("", fn, cb_data);
1448 }
1449
1450 int update_ref(const char *action, const char *refname,
1451 const unsigned char *sha1, const unsigned char *oldval,
1452 int flags, enum action_on_err onerr)
1453 {
1454 static struct ref_lock *lock;
1455 lock = lock_any_ref_for_update(refname, oldval, flags);
1456 if (!lock) {
1457 const char *str = "Cannot lock the ref '%s'.";
1458 switch (onerr) {
1459 case MSG_ON_ERR: error(str, refname); break;
1460 case DIE_ON_ERR: die(str, refname); break;
1461 case QUIET_ON_ERR: break;
1462 }
1463 return 1;
1464 }
1465 if (write_ref_sha1(lock, sha1, action) < 0) {
1466 const char *str = "Cannot update the ref '%s'.";
1467 switch (onerr) {
1468 case MSG_ON_ERR: error(str, refname); break;
1469 case DIE_ON_ERR: die(str, refname); break;
1470 case QUIET_ON_ERR: break;
1471 }
1472 return 1;
1473 }
1474 return 0;
1475 }
1476
1477 struct ref *find_ref_by_name(struct ref *list, const char *name)
1478 {
1479 for ( ; list; list = list->next)
1480 if (!strcmp(list->name, name))
1481 return list;
1482 return NULL;
1483 }