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Date:: Sun Nov 1 16:28:46 2020 UTC
Message:: convert all remaining instances of chmod(2) to fchmod(2) ok stsp
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1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <sys/queue.h>
19 #include <sys/stat.h>
20 
21 #include <errno.h>
22 #include <ctype.h>
23 #include <dirent.h>
24 #include <limits.h>
25 #include <sha1.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <unistd.h>
30 #include <util.h>
31 #include <zlib.h>
32 #include <time.h>
33 #include <libgen.h>
34 
35 #include "got_error.h"
36 #include "got_object.h"
37 #include "got_repository.h"
38 #include "got_reference.h"
39 #include "got_opentemp.h"
40 #include "got_path.h"
41 
42 #include "got_lib_sha1.h"
43 #include "got_lib_delta.h"
44 #include "got_lib_inflate.h"
45 #include "got_lib_object.h"
46 #include "got_lib_lockfile.h"
47 
48 #ifndef nitems
49 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
50 #endif
51 
52 #define GOT_REF_HEADS	"heads"
53 #define GOT_REF_TAGS	"tags"
54 #define GOT_REF_REMOTES	"remotes"
55 
56 /*
57  * We do not resolve tags yet, and don't yet care about sorting refs either,
58  * so packed-refs files we write contain a minimal header which disables all
59  * packed-refs "traits" supported by Git.
60  */
61 #define GOT_PACKED_REFS_HEADER	"# pack-refs with:"
62 
63 /* A symbolic reference. */
64 struct got_symref {
65 	char *name;
66 	char *ref;
67 };
68 
69 #define GOT_REF_RECURSE_MAX	20
70 
71 /* A non-symbolic reference (there is no better designation). */
72 struct got_ref {
73 	char *name;
74 	u_int8_t sha1[SHA1_DIGEST_LENGTH];
75 };
76 
77 /* A reference which points to an arbitrary object. */
78 struct got_reference {
79 	unsigned int flags;
80 #define GOT_REF_IS_SYMBOLIC	0x01
81 #define GOT_REF_IS_PACKED	0x02
82 
83 	union {
84 		struct got_ref ref;
85 		struct got_symref symref;
86 	} ref;
87 
88 	struct got_lockfile *lf;
89 };
90 
91 static const struct got_error *
92 alloc_ref(struct got_reference **ref, const char *name,
93     struct got_object_id *id, int flags)
94 {
95 	const struct got_error *err = NULL;
96 
97 	*ref = calloc(1, sizeof(**ref));
98 	if (*ref == NULL)
99 		return got_error_from_errno("calloc");
100 
101 	memcpy((*ref)->ref.ref.sha1, id->sha1, sizeof((*ref)->ref.ref.sha1));
102 	(*ref)->flags = flags;
103 	(*ref)->ref.ref.name = strdup(name);
104 	if ((*ref)->ref.ref.name == NULL) {
105 		err = got_error_from_errno("strdup");
106 		got_ref_close(*ref);
107 		*ref = NULL;
108 	}
109 	return err;
110 }
111 
112 static const struct got_error *
113 alloc_symref(struct got_reference **ref, const char *name,
114     const char *target_ref, int flags)
115 {
116 	const struct got_error *err = NULL;
117 
118 	*ref = calloc(1, sizeof(**ref));
119 	if (*ref == NULL)
120 		return got_error_from_errno("calloc");
121 
122 	(*ref)->flags = GOT_REF_IS_SYMBOLIC | flags;
123 	(*ref)->ref.symref.name = strdup(name);
124 	if ((*ref)->ref.symref.name == NULL) {
125 		err = got_error_from_errno("strdup");
126 		got_ref_close(*ref);
127 		*ref = NULL;
128 		return err;
129 	}
130 	(*ref)->ref.symref.ref = strdup(target_ref);
131 	if ((*ref)->ref.symref.ref == NULL) {
132 		err = got_error_from_errno("strdup");
133 		got_ref_close(*ref);
134 		*ref = NULL;
135 	}
136 	return err;
137 }
138 
139 static const struct got_error *
140 parse_symref(struct got_reference **ref, const char *name, const char *line)
141 {
142 	if (line[0] == '\0')
143 		return got_error(GOT_ERR_BAD_REF_DATA);
144 
145 	return alloc_symref(ref, name, line, 0);
146 }
147 
148 static const struct got_error *
149 parse_ref_line(struct got_reference **ref, const char *name, const char *line)
150 {
151 	struct got_object_id id;
152 
153 	if (strncmp(line, "ref: ", 5) == 0) {
154 		line += 5;
155 		return parse_symref(ref, name, line);
156 	}
157 
158 	if (!got_parse_sha1_digest(id.sha1, line))
159 		return got_error(GOT_ERR_BAD_REF_DATA);
160 
161 	return alloc_ref(ref, name, &id, 0);
162 }
163 
164 static const struct got_error *
165 parse_ref_file(struct got_reference **ref, const char *name,
166     const char *absname, const char *abspath, int lock)
167 {
168 	const struct got_error *err = NULL;
169 	FILE *f;
170 	char *line = NULL;
171 	size_t linesize = 0;
172 	ssize_t linelen;
173 	struct got_lockfile *lf = NULL;
174 
175 	if (lock) {
176 		err = got_lockfile_lock(&lf, abspath);
177 		if (err) {
178 			if (err->code == GOT_ERR_ERRNO && errno == ENOENT)
179 				err = got_error_not_ref(name);
180 			return err;
181 		}
182 	}
183 
184 	f = fopen(abspath, "rb");
185 	if (f == NULL) {
186 		if (errno != ENOTDIR && errno != ENOENT)
187 			err = got_error_from_errno2("fopen", abspath);
188 		else
189 			err = got_error_not_ref(name);
190 		if (lock)
191 			got_lockfile_unlock(lf);
192 		return err;
193 	}
194 
195 	linelen = getline(&line, &linesize, f);
196 	if (linelen == -1) {
197 		if (feof(f))
198 			err = NULL; /* ignore empty files (could be locks) */
199 		else {
200 			if (errno == EISDIR)
201 				err = got_error(GOT_ERR_NOT_REF);
202 			else if (ferror(f))
203 				err = got_ferror(f, GOT_ERR_IO);
204 			else
205 				err = got_error_from_errno2("getline", abspath);
206 		}
207 		if (lock)
208 			got_lockfile_unlock(lf);
209 		goto done;
210 	}
211 	while (linelen > 0 && line[linelen - 1] == '\n') {
212 		line[linelen - 1] = '\0';
213 		linelen--;
214 	}
215 
216 	err = parse_ref_line(ref, absname, line);
217 	if (lock) {
218 		if (err)
219 			got_lockfile_unlock(lf);
220 		else {
221 			if (*ref)
222 				(*ref)->lf = lf;
223 			else
224 				got_lockfile_unlock(lf);
225 		}
226 	}
227 done:
228 	free(line);
229 	if (fclose(f) != 0 && err == NULL) {
230 		err = got_error_from_errno("fclose");
231 		if (*ref) {
232 			if (lock)
233 				got_ref_unlock(*ref);
234 			got_ref_close(*ref);
235 			*ref = NULL;
236 		}
237 	}
238 	return err;
239 }
240 
241 static int
242 is_well_known_ref(const char *refname)
243 {
244 	return (strcmp(refname, GOT_REF_HEAD) == 0 ||
245 	    strcmp(refname, GOT_REF_ORIG_HEAD) == 0 ||
246 	    strcmp(refname, GOT_REF_MERGE_HEAD) == 0 ||
247 	    strcmp(refname, GOT_REF_FETCH_HEAD) == 0);
248 }
249 
250 static char *
251 get_refs_dir_path(struct got_repository *repo, const char *refname)
252 {
253 	if (is_well_known_ref(refname) || strncmp(refname, "refs/", 5) == 0)
254 		return strdup(got_repo_get_path_git_dir(repo));
255 
256 	return got_repo_get_path_refs(repo);
257 }
258 
259 static int
260 is_valid_ref_name(const char *name)
261 {
262 	const char *s, *seg;
263 	const char forbidden[] = { ' ', '~', '^', ':', '?', '*', '[' , '\\' };
264 	const char *forbidden_seq[] = { "//", "..", "@{" };
265 	const char *lfs = GOT_LOCKFILE_SUFFIX;
266 	const size_t lfs_len = sizeof(GOT_LOCKFILE_SUFFIX) - 1;
267 	int i;
268 
269 	if (name[0] == '@' && name[1] == '\0')
270 		return 0;
271 
272 	s = name;
273 	seg = s;
274 	if (seg[0] == '\0' || seg[0] == '.' || seg[0] == '/')
275 		return 0;
276 	while (*s) {
277 		for (i = 0; i < nitems(forbidden); i++) {
278 			if (*s == forbidden[i])
279 				return 0;
280 		}
281 		for (i = 0; i < nitems(forbidden_seq); i++) {
282 			if (s[0] == forbidden_seq[i][0] &&
283 			    s[1] == forbidden_seq[i][1])
284 				return 0;
285 		}
286 		if (iscntrl((unsigned char)s[0]))
287 			return 0;
288 		if (s[0] == '.' && s[1] == '\0')
289 			return 0;
290 		if (*s == '/') {
291 			const char *nextseg = s + 1;
292 			if (nextseg[0] == '\0' || nextseg[0] == '.' ||
293 			    nextseg[0] == '/')
294 				return 0;
295 			if (seg <= s - lfs_len &&
296 			    strncmp(s - lfs_len, lfs, lfs_len) == 0)
297 				return 0;
298 			seg = nextseg;
299 		}
300 		s++;
301 	}
302 
303 	if (seg <= s - lfs_len &&
304 	    strncmp(s - lfs_len, lfs, lfs_len) == 0)
305 		return 0;
306 
307 	return 1;
308 }
309 
310 const struct got_error *
311 got_ref_alloc(struct got_reference **ref, const char *name,
312     struct got_object_id *id)
313 {
314 	if (!is_valid_ref_name(name))
315 		return got_error_path(name, GOT_ERR_BAD_REF_NAME);
316 
317 	return alloc_ref(ref, name, id, 0);
318 }
319 
320 const struct got_error *
321 got_ref_alloc_symref(struct got_reference **ref, const char *name,
322 	struct got_reference *target_ref)
323 {
324 	if (!is_valid_ref_name(name))
325 		return got_error_path(name, GOT_ERR_BAD_REF_NAME);
326 
327 	return alloc_symref(ref, name, got_ref_get_name(target_ref), 0);
328 }
329 
330 static const struct got_error *
331 parse_packed_ref_line(struct got_reference **ref, const char *abs_refname,
332     const char *line)
333 {
334 	struct got_object_id id;
335 	const char *name;
336 
337 	*ref = NULL;
338 
339 	if (line[0] == '#' || line[0] == '^')
340 		return NULL;
341 
342 	if (!got_parse_sha1_digest(id.sha1, line))
343 		return got_error(GOT_ERR_BAD_REF_DATA);
344 
345 	if (abs_refname) {
346 		if (strcmp(line + SHA1_DIGEST_STRING_LENGTH, abs_refname) != 0)
347 			return NULL;
348 		name = abs_refname;
349 	} else
350 		name = line + SHA1_DIGEST_STRING_LENGTH;
351 
352 	return alloc_ref(ref, name, &id, GOT_REF_IS_PACKED);
353 }
354 
355 static const struct got_error *
356 open_packed_ref(struct got_reference **ref, FILE *f, const char **subdirs,
357     int nsubdirs, const char *refname)
358 {
359 	const struct got_error *err = NULL;
360 	char *abs_refname;
361 	char *line;
362 	size_t len;
363 	const char delim[3] = {'\0', '\0', '\0'};
364 	int i, ref_is_absolute = (strncmp(refname, "refs/", 5) == 0);
365 
366 	*ref = NULL;
367 
368 	if (ref_is_absolute)
369 		abs_refname = (char *)refname;
370 	do {
371 		line = fparseln(f, &len, NULL, delim, 0);
372 		if (line == NULL) {
373 			if (feof(f))
374 				break;
375 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
376 			break;
377 		}
378 		for (i = 0; i < nsubdirs; i++) {
379 			if (!ref_is_absolute &&
380 			    asprintf(&abs_refname, "refs/%s/%s", subdirs[i],
381 			    refname) == -1)
382 				return got_error_from_errno("asprintf");
383 			err = parse_packed_ref_line(ref, abs_refname, line);
384 			if (!ref_is_absolute)
385 				free(abs_refname);
386 			if (err || *ref != NULL)
387 				break;
388 		}
389 		free(line);
390 		if (err)
391 			break;
392 	} while (*ref == NULL);
393 
394 	return err;
395 }
396 
397 static const struct got_error *
398 open_ref(struct got_reference **ref, const char *path_refs, const char *subdir,
399     const char *name, int lock)
400 {
401 	const struct got_error *err = NULL;
402 	char *path = NULL;
403 	char *absname = NULL;
404 	int ref_is_absolute = (strncmp(name, "refs/", 5) == 0);
405 	int ref_is_well_known = (subdir[0] == '\0' && is_well_known_ref(name));
406 
407 	*ref = NULL;
408 
409 	if (ref_is_absolute || ref_is_well_known) {
410 		if (asprintf(&path, "%s/%s", path_refs, name) == -1)
411 			return got_error_from_errno("asprintf");
412 		absname = (char *)name;
413 	} else {
414 		if (asprintf(&path, "%s/%s%s%s", path_refs, subdir,
415 		    subdir[0] ? "/" : "", name) == -1)
416 			return got_error_from_errno("asprintf");
417 
418 		if (asprintf(&absname, "refs/%s%s%s",
419 		    subdir, subdir[0] ? "/" : "", name) == -1) {
420 			err = got_error_from_errno("asprintf");
421 			goto done;
422 		}
423 	}
424 
425 	err = parse_ref_file(ref, name, absname, path, lock);
426 done:
427 	if (!ref_is_absolute && !ref_is_well_known)
428 		free(absname);
429 	free(path);
430 	return err;
431 }
432 
433 const struct got_error *
434 got_ref_open(struct got_reference **ref, struct got_repository *repo,
435    const char *refname, int lock)
436 {
437 	const struct got_error *err = NULL;
438 	char *path_refs = NULL;
439 	const char *subdirs[] = {
440 	    GOT_REF_HEADS, GOT_REF_TAGS, GOT_REF_REMOTES
441 	};
442 	int i, well_known = is_well_known_ref(refname);
443 	struct got_lockfile *lf = NULL;
444 
445 	*ref = NULL;
446 
447 	path_refs = get_refs_dir_path(repo, refname);
448 	if (path_refs == NULL) {
449 		err = got_error_from_errno2("get_refs_dir_path", refname);
450 		goto done;
451 	}
452 
453 	if (well_known) {
454 		err = open_ref(ref, path_refs, "", refname, lock);
455 	} else {
456 		char *packed_refs_path;
457 		FILE *f;
458 
459 		/* Search on-disk refs before packed refs! */
460 		for (i = 0; i < nitems(subdirs); i++) {
461 			err = open_ref(ref, path_refs, subdirs[i], refname,
462 			    lock);
463 			if ((err && err->code != GOT_ERR_NOT_REF) || *ref)
464 				goto done;
465 		}
466 
467 		packed_refs_path = got_repo_get_path_packed_refs(repo);
468 		if (packed_refs_path == NULL) {
469 			err = got_error_from_errno(
470 			    "got_repo_get_path_packed_refs");
471 			goto done;
472 		}
473 
474 		if (lock) {
475 			err = got_lockfile_lock(&lf, packed_refs_path);
476 			if (err)
477 				goto done;
478 		}
479 		f = fopen(packed_refs_path, "rb");
480 		free(packed_refs_path);
481 		if (f != NULL) {
482 			err = open_packed_ref(ref, f, subdirs, nitems(subdirs),
483 			    refname);
484 			if (!err) {
485 				if (fclose(f) != 0) {
486 					err = got_error_from_errno("fclose");
487 					got_ref_close(*ref);
488 					*ref = NULL;
489 				} else if (*ref)
490 					(*ref)->lf = lf;
491 			}
492 		}
493 	}
494 done:
495 	if (!err && *ref == NULL)
496 		err = got_error_not_ref(refname);
497 	if (err && lf)
498 		got_lockfile_unlock(lf);
499 	free(path_refs);
500 	return err;
501 }
502 
503 void
504 got_ref_close(struct got_reference *ref)
505 {
506 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
507 		free(ref->ref.symref.name);
508 		free(ref->ref.symref.ref);
509 	} else
510 		free(ref->ref.ref.name);
511 	free(ref);
512 }
513 
514 struct got_reference *
515 got_ref_dup(struct got_reference *ref)
516 {
517 	struct got_reference *ret;
518 
519 	ret = calloc(1, sizeof(*ret));
520 	if (ret == NULL)
521 		return NULL;
522 
523 	ret->flags = ref->flags;
524 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
525 		ret->ref.symref.name = strdup(ref->ref.symref.name);
526 		if (ret->ref.symref.name == NULL) {
527 			free(ret);
528 			return NULL;
529 		}
530 		ret->ref.symref.ref = strdup(ref->ref.symref.ref);
531 		if (ret->ref.symref.ref == NULL) {
532 			free(ret->ref.symref.name);
533 			free(ret);
534 			return NULL;
535 		}
536 	} else {
537 		ref->ref.ref.name = strdup(ref->ref.ref.name);
538 		if (ref->ref.ref.name == NULL) {
539 			free(ret);
540 			return NULL;
541 		}
542 		memcpy(ret->ref.ref.sha1, ref->ref.ref.sha1,
543 		    sizeof(ret->ref.ref.sha1));
544 	}
545 
546 	return ret;
547 }
548 
549 const struct got_error *
550 got_reflist_entry_dup(struct got_reflist_entry **newp,
551     struct got_reflist_entry *re)
552 {
553 	const struct got_error *err = NULL;
554 	struct got_reflist_entry *new;
555 
556 	*newp = NULL;
557 
558 	new = malloc(sizeof(*new));
559 	if (new == NULL)
560 		return got_error_from_errno("malloc");
561 
562 	new->ref = got_ref_dup(re->ref);
563 	if (new->ref == NULL) {
564 		err = got_error_from_errno("got_ref_dup");
565 		free(new);
566 		return err;
567 	}
568 
569 	*newp = new;
570 	return NULL;
571 }
572 
573 static const struct got_error *
574 resolve_symbolic_ref(struct got_reference **resolved,
575     struct got_repository *repo, struct got_reference *ref)
576 {
577 	struct got_reference *nextref;
578 	const struct got_error *err;
579 
580 	err = got_ref_open(&nextref, repo, ref->ref.symref.ref, 0);
581 	if (err)
582 		return err;
583 
584 	if (nextref->flags & GOT_REF_IS_SYMBOLIC)
585 		err = resolve_symbolic_ref(resolved, repo, nextref);
586 	else
587 		*resolved = got_ref_dup(nextref);
588 
589 	got_ref_close(nextref);
590 	return err;
591 }
592 
593 static const struct got_error *
594 ref_resolve(struct got_object_id **id, struct got_repository *repo,
595     struct got_reference *ref, int recursion)
596 {
597 	const struct got_error *err;
598 
599 	if (recursion <= 0)
600 		return got_error_msg(GOT_ERR_RECURSION,
601 		    "reference recursion limit reached");
602 
603 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
604 		struct got_reference *resolved = NULL;
605 		err = resolve_symbolic_ref(&resolved, repo, ref);
606 		if (err == NULL)
607 			err = ref_resolve(id, repo, resolved, --recursion);
608 		if (resolved)
609 			got_ref_close(resolved);
610 		return err;
611 	}
612 
613 	*id = calloc(1, sizeof(**id));
614 	if (*id == NULL)
615 		return got_error_from_errno("calloc");
616 	memcpy((*id)->sha1, ref->ref.ref.sha1, sizeof((*id)->sha1));
617 	return NULL;
618 }
619 
620 const struct got_error *
621 got_ref_resolve(struct got_object_id **id, struct got_repository *repo,
622     struct got_reference *ref)
623 {
624 	return ref_resolve(id, repo, ref, GOT_REF_RECURSE_MAX);
625 }
626 
627 char *
628 got_ref_to_str(struct got_reference *ref)
629 {
630 	char *str;
631 
632 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
633 		return strdup(ref->ref.symref.ref);
634 
635 	str = malloc(SHA1_DIGEST_STRING_LENGTH);
636 	if (str == NULL)
637 		return NULL;
638 
639 	if (got_sha1_digest_to_str(ref->ref.ref.sha1, str,
640 	    SHA1_DIGEST_STRING_LENGTH) == NULL) {
641 		free(str);
642 		return NULL;
643 	}
644 
645 	return str;
646 }
647 
648 const char *
649 got_ref_get_name(struct got_reference *ref)
650 {
651 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
652 		return ref->ref.symref.name;
653 
654 	return ref->ref.ref.name;
655 }
656 
657 const char *
658 got_ref_get_symref_target(struct got_reference *ref)
659 {
660 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
661 		return ref->ref.symref.ref;
662 
663 	return NULL;
664 }
665 
666 const struct got_error *
667 got_ref_cmp_by_name(void *arg, int *cmp, struct got_reference *re1,
668     struct got_reference* re2)
669 {
670 	const char *name1 = got_ref_get_name(re1);
671 	const char *name2 = got_ref_get_name(re2);
672 
673 	*cmp = got_path_cmp(name1, name2, strlen(name1), strlen(name2));
674 	return NULL;
675 }
676 
677 const struct got_error *
678 got_ref_cmp_tags(void *arg, int *cmp, struct got_reference *ref1,
679     struct got_reference *ref2)
680 {
681 	const struct got_error *err = NULL;
682 	struct got_repository *repo = arg;
683 	struct got_object_id *id1, *id2 = NULL;
684 	struct got_tag_object *tag1 = NULL, *tag2 = NULL;
685 	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
686 	time_t time1, time2;
687 
688 	*cmp = 0;
689 
690 	err = got_ref_resolve(&id1, repo, ref1);
691 	if (err)
692 		return err;
693 	err = got_object_open_as_tag(&tag1, repo, id1);
694 	if (err) {
695 		if (err->code != GOT_ERR_OBJ_TYPE)
696 			goto done;
697 		/* "lightweight" tag */
698 		err = got_object_open_as_commit(&commit1, repo, id1);
699 		if (err)
700 			goto done;
701 		time1 = got_object_commit_get_committer_time(commit1);
702 	} else
703 		time1 = got_object_tag_get_tagger_time(tag1);
704 
705 	err = got_ref_resolve(&id2, repo, ref2);
706 	if (err)
707 		goto done;
708 	err = got_object_open_as_tag(&tag2, repo, id2);
709 	if (err) {
710 		if (err->code != GOT_ERR_OBJ_TYPE)
711 			goto done;
712 		/* "lightweight" tag */
713 		err = got_object_open_as_commit(&commit2, repo, id2);
714 		if (err)
715 			goto done;
716 		time2 = got_object_commit_get_committer_time(commit2);
717 	} else
718 		time2 = got_object_tag_get_tagger_time(tag2);
719 
720 	/* Put latest tags first. */
721 	if (time1 < time2)
722 		*cmp = 1;
723 	else if (time1 > time2)
724 		*cmp = -1;
725 	else
726 		err = got_ref_cmp_by_name(NULL, cmp, ref2, ref1);
727 done:
728 	free(id1);
729 	free(id2);
730 	if (tag1)
731 		got_object_tag_close(tag1);
732 	if (tag2)
733 		got_object_tag_close(tag2);
734 	if (commit1)
735 		got_object_commit_close(commit1);
736 	if (commit2)
737 		got_object_commit_close(commit2);
738 	return err;
739 }
740 
741 static const struct got_error *
742 insert_ref(struct got_reflist_entry **newp, struct got_reflist_head *refs,
743     struct got_reference *ref, struct got_repository *repo,
744     got_ref_cmp_cb cmp_cb, void *cmp_arg)
745 {
746 	const struct got_error *err;
747 	struct got_reflist_entry *new, *re, *prev = NULL;
748 	int cmp;
749 
750 	*newp = NULL;
751 
752 	new = malloc(sizeof(*new));
753 	if (new == NULL)
754 		return got_error_from_errno("malloc");
755 	new->ref = ref;
756 	*newp = new;
757 
758 	/*
759 	 * We must de-duplicate entries on insert because packed-refs may
760 	 * contain redundant entries. On-disk refs take precedence.
761 	 * This code assumes that on-disk revs are read before packed-refs.
762 	 * We're iterating the list anyway, so insert elements sorted by name.
763 	 */
764 	re = SIMPLEQ_FIRST(refs);
765 	while (re) {
766 		err = (*cmp_cb)(cmp_arg, &cmp, re->ref, new->ref);
767 		if (err)
768 			return err;
769 		if (cmp == 0) {
770 			/* duplicate */
771 			free(new);
772 			*newp = NULL;
773 			return NULL;
774 		} else if (cmp > 0) {
775 			if (prev)
776 				SIMPLEQ_INSERT_AFTER(refs, prev, new, entry);
777 			else
778 				SIMPLEQ_INSERT_HEAD(refs, new, entry);
779 			return NULL;
780 		} else {
781 			prev = re;
782 			re = SIMPLEQ_NEXT(re, entry);
783 		}
784 	}
785 
786 	SIMPLEQ_INSERT_TAIL(refs, new, entry);
787 	return NULL;
788 }
789 
790 static const struct got_error *
791 gather_on_disk_refs(struct got_reflist_head *refs, const char *path_refs,
792     const char *subdir, struct got_repository *repo,
793     got_ref_cmp_cb cmp_cb, void *cmp_arg)
794 {
795 	const struct got_error *err = NULL;
796 	DIR *d = NULL;
797 	char *path_subdir;
798 
799 	while (subdir[0] == '/')
800 		subdir++;
801 
802 	if (asprintf(&path_subdir, "%s/%s", path_refs, subdir) == -1)
803 		return got_error_from_errno("asprintf");
804 
805 	d = opendir(path_subdir);
806 	if (d == NULL)
807 		goto done;
808 
809 	for (;;) {
810 		struct dirent *dent;
811 		struct got_reference *ref;
812 		char *child;
813 		int type;
814 
815 		dent = readdir(d);
816 		if (dent == NULL)
817 			break;
818 
819 		if (strcmp(dent->d_name, ".") == 0 ||
820 		    strcmp(dent->d_name, "..") == 0)
821 			continue;
822 
823 		err = got_path_dirent_type(&type, path_subdir, dent);
824 		if (err)
825 			break;
826 
827 		switch (type) {
828 		case DT_REG:
829 			err = open_ref(&ref, path_refs, subdir, dent->d_name,
830 			    0);
831 			if (err)
832 				goto done;
833 			if (ref) {
834 				struct got_reflist_entry *new;
835 				err = insert_ref(&new, refs, ref, repo,
836 				    cmp_cb, cmp_arg);
837 				if (err || new == NULL /* duplicate */)
838 					got_ref_close(ref);
839 				if (err)
840 					goto done;
841 			}
842 			break;
843 		case DT_DIR:
844 			if (asprintf(&child, "%s%s%s", subdir,
845 			    subdir[0] == '\0' ? "" : "/", dent->d_name) == -1) {
846 				err = got_error_from_errno("asprintf");
847 				break;
848 			}
849 			err = gather_on_disk_refs(refs, path_refs, child, repo,
850 			    cmp_cb, cmp_arg);
851 			free(child);
852 			break;
853 		default:
854 			break;
855 		}
856 	}
857 done:
858 	if (d)
859 		closedir(d);
860 	free(path_subdir);
861 	return err;
862 }
863 
864 const struct got_error *
865 got_ref_list(struct got_reflist_head *refs, struct got_repository *repo,
866     const char *ref_namespace, got_ref_cmp_cb cmp_cb, void *cmp_arg)
867 {
868 	const struct got_error *err;
869 	char *packed_refs_path, *path_refs = NULL;
870 	char *abs_namespace = NULL;
871 	char *buf = NULL, *ondisk_ref_namespace = NULL;
872 	FILE *f = NULL;
873 	struct got_reference *ref;
874 	struct got_reflist_entry *new;
875 
876 	if (ref_namespace == NULL || ref_namespace[0] == '\0') {
877 		path_refs = get_refs_dir_path(repo, GOT_REF_HEAD);
878 		if (path_refs == NULL) {
879 			err = got_error_from_errno("get_refs_dir_path");
880 			goto done;
881 		}
882 		err = open_ref(&ref, path_refs, "", GOT_REF_HEAD, 0);
883 		if (err)
884 			goto done;
885 		err = insert_ref(&new, refs, ref, repo,
886 		    cmp_cb, cmp_arg);
887 		if (err || new == NULL /* duplicate */)
888 			got_ref_close(ref);
889 		if (err && err->code != GOT_ERR_NOT_REF)
890 			goto done;
891 	} else {
892 		/* Try listing a single reference. */
893 		const char *refname = ref_namespace;
894 		path_refs = get_refs_dir_path(repo, refname);
895 		if (path_refs == NULL) {
896 			err = got_error_from_errno("get_refs_dir_path");
897 			goto done;
898 		}
899 		err = open_ref(&ref, path_refs, "", refname, 0);
900 		if (err) {
901 			if (err->code != GOT_ERR_NOT_REF)
902 				goto done;
903 			/* Try to look up references in a given namespace. */
904 		} else {
905 			err = insert_ref(&new, refs, ref, repo,
906 			    cmp_cb, cmp_arg);
907 			if (err || new == NULL /* duplicate */)
908 				got_ref_close(ref);
909 			return err;
910 		}
911 	}
912 
913 	if (ref_namespace) {
914 		size_t len;
915 		/* Canonicalize the path to eliminate double-slashes if any. */
916 		if (asprintf(&abs_namespace, "/%s", ref_namespace) == -1) {
917 			err = got_error_from_errno("asprintf");
918 			goto done;
919 		}
920 		len = strlen(abs_namespace) + 1;
921 		buf = malloc(len);
922 		if (buf == NULL) {
923 			err = got_error_from_errno("malloc");
924 			goto done;
925 		}
926 		err = got_canonpath(abs_namespace, buf, len);
927 		if (err)
928 			goto done;
929 		ondisk_ref_namespace = buf;
930 		while (ondisk_ref_namespace[0] == '/')
931 			ondisk_ref_namespace++;
932 		if (strncmp(ondisk_ref_namespace, "refs/", 5) == 0)
933 			ondisk_ref_namespace += 5;
934 		else if (strcmp(ondisk_ref_namespace, "refs") == 0)
935 			ondisk_ref_namespace = "";
936 	}
937 
938 	/* Gather on-disk refs before parsing packed-refs. */
939 	free(path_refs);
940 	path_refs = get_refs_dir_path(repo, "");
941 	if (path_refs == NULL) {
942 		err = got_error_from_errno("get_refs_dir_path");
943 		goto done;
944 	}
945 	err = gather_on_disk_refs(refs, path_refs,
946 	    ondisk_ref_namespace ? ondisk_ref_namespace : "", repo,
947 	    cmp_cb, cmp_arg);
948 	if (err)
949 		goto done;
950 
951 	/*
952 	 * The packed-refs file may contain redundant entries, in which
953 	 * case on-disk refs take precedence.
954 	 */
955 	packed_refs_path = got_repo_get_path_packed_refs(repo);
956 	if (packed_refs_path == NULL) {
957 		err = got_error_from_errno("got_repo_get_path_packed_refs");
958 		goto done;
959 	}
960 
961 	f = fopen(packed_refs_path, "r");
962 	free(packed_refs_path);
963 	if (f) {
964 		char *line;
965 		size_t len;
966 		const char delim[3] = {'\0', '\0', '\0'};
967 		for (;;) {
968 			line = fparseln(f, &len, NULL, delim, 0);
969 			if (line == NULL) {
970 				if (feof(f))
971 					break;
972 				err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
973 				goto done;
974 			}
975 			err = parse_packed_ref_line(&ref, NULL, line);
976 			free(line);
977 			if (err)
978 				goto done;
979 			if (ref) {
980 				if (ref_namespace) {
981 					const char *name;
982 					name = got_ref_get_name(ref);
983 					if (!got_path_is_child(name,
984 					    ref_namespace,
985 					    strlen(ref_namespace))) {
986 						got_ref_close(ref);
987 						continue;
988 					}
989 				}
990 				err = insert_ref(&new, refs, ref, repo,
991 				    cmp_cb, cmp_arg);
992 				if (err || new == NULL /* duplicate */)
993 					got_ref_close(ref);
994 				if (err)
995 					goto done;
996 			}
997 		}
998 	}
999 done:
1000 	free(abs_namespace);
1001 	free(buf);
1002 	free(path_refs);
1003 	if (f && fclose(f) != 0 && err == NULL)
1004 		err = got_error_from_errno("fclose");
1005 	return err;
1006 }
1007 
1008 void
1009 got_ref_list_free(struct got_reflist_head *refs)
1010 {
1011 	struct got_reflist_entry *re;
1012 
1013 	while (!SIMPLEQ_EMPTY(refs)) {
1014 		re = SIMPLEQ_FIRST(refs);
1015 		SIMPLEQ_REMOVE_HEAD(refs, entry);
1016 		got_ref_close(re->ref);
1017 		free(re);
1018 	}
1019 
1020 }
1021 
1022 int
1023 got_ref_is_symbolic(struct got_reference *ref)
1024 {
1025 	return (ref->flags & GOT_REF_IS_SYMBOLIC);
1026 }
1027 
1028 const struct got_error *
1029 got_ref_change_ref(struct got_reference *ref, struct got_object_id *id)
1030 {
1031 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
1032 		return got_error(GOT_ERR_BAD_REF_TYPE);
1033 
1034 	memcpy(ref->ref.ref.sha1, id->sha1, sizeof(ref->ref.ref.sha1));
1035 	return NULL;
1036 }
1037 
1038 const struct got_error *
1039 got_ref_change_symref(struct got_reference *ref, const char *refname)
1040 {
1041 	char *new_name;
1042 
1043 	if ((ref->flags & GOT_REF_IS_SYMBOLIC) == 0)
1044 		return got_error(GOT_ERR_BAD_REF_TYPE);
1045 
1046 	new_name = strdup(refname);
1047 	if (new_name == NULL)
1048 		return got_error_from_errno("strdup");
1049 
1050 	free(ref->ref.symref.ref);
1051 	ref->ref.symref.ref = new_name;
1052 	return NULL;
1053 }
1054 
1055 const struct got_error *
1056 got_ref_change_symref_to_ref(struct got_reference *symref,
1057     struct got_object_id *id)
1058 {
1059 	if ((symref->flags & GOT_REF_IS_SYMBOLIC) == 0)
1060 		return got_error(GOT_ERR_BAD_REF_TYPE);
1061 
1062 	symref->ref.ref.name = symref->ref.symref.name;
1063 	memcpy(symref->ref.ref.sha1, id->sha1, SHA1_DIGEST_LENGTH);
1064 	symref->flags &= ~GOT_REF_IS_SYMBOLIC;
1065 	return NULL;
1066 }
1067 
1068 const struct got_error *
1069 got_ref_write(struct got_reference *ref, struct got_repository *repo)
1070 {
1071 	const struct got_error *err = NULL, *unlock_err = NULL;
1072 	const char *name = got_ref_get_name(ref);
1073 	char *path_refs = NULL, *path = NULL, *tmppath = NULL;
1074 	struct got_lockfile *lf = NULL;
1075 	FILE *f = NULL;
1076 	size_t n;
1077 	struct stat sb;
1078 
1079 	path_refs = get_refs_dir_path(repo, name);
1080 	if (path_refs == NULL) {
1081 		err = got_error_from_errno2("get_refs_dir_path", name);
1082 		goto done;
1083 	}
1084 
1085 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1086 		err = got_error_from_errno("asprintf");
1087 		goto done;
1088 	}
1089 
1090 	err = got_opentemp_named(&tmppath, &f, path);
1091 	if (err) {
1092 		char *parent;
1093 		if (!(err->code == GOT_ERR_ERRNO && errno == ENOENT))
1094 			goto done;
1095 		err = got_path_dirname(&parent, path);
1096 		if (err)
1097 			goto done;
1098 		err = got_path_mkdir(parent);
1099 		free(parent);
1100 		if (err)
1101 			goto done;
1102 		err = got_opentemp_named(&tmppath, &f, path);
1103 		if (err)
1104 			goto done;
1105 	}
1106 
1107 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
1108 		n = fprintf(f, "ref: %s\n", ref->ref.symref.ref);
1109 		if (n != strlen(ref->ref.symref.ref) + 6) {
1110 			err = got_ferror(f, GOT_ERR_IO);
1111 			goto done;
1112 		}
1113 	} else {
1114 		char hex[SHA1_DIGEST_STRING_LENGTH];
1115 		if (got_sha1_digest_to_str(ref->ref.ref.sha1, hex,
1116 		    sizeof(hex)) == NULL) {
1117 			err = got_error(GOT_ERR_BAD_REF_DATA);
1118 			goto done;
1119 		}
1120 		n = fprintf(f, "%s\n", hex);
1121 		if (n != sizeof(hex)) {
1122 			err = got_ferror(f, GOT_ERR_IO);
1123 			goto done;
1124 		}
1125 	}
1126 
1127 	if (ref->lf == NULL) {
1128 		err = got_lockfile_lock(&lf, path);
1129 		if (err)
1130 			goto done;
1131 	}
1132 
1133 	/* XXX: check if old content matches our expectations? */
1134 
1135 	if (stat(path, &sb) != 0) {
1136 		if (errno != ENOENT) {
1137 			err = got_error_from_errno2("stat", path);
1138 			goto done;
1139 		}
1140 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
1141 	}
1142 
1143 	if (fchmod(fileno(f), sb.st_mode) != 0) {
1144 		err = got_error_from_errno2("fchmod", tmppath);
1145 		goto done;
1146 	}
1147 
1148 	if (rename(tmppath, path) != 0) {
1149 		err = got_error_from_errno3("rename", tmppath, path);
1150 		goto done;
1151 	}
1152 	free(tmppath);
1153 	tmppath = NULL;
1154 done:
1155 	if (ref->lf == NULL && lf)
1156 		unlock_err = got_lockfile_unlock(lf);
1157 	if (f) {
1158 		if (fclose(f) != 0 && err == NULL)
1159 			err = got_error_from_errno("fclose");
1160 	}
1161 	free(path_refs);
1162 	free(path);
1163 	if (tmppath) {
1164 		if (unlink(tmppath) != 0 && err == NULL)
1165 			err = got_error_from_errno2("unlink", tmppath);
1166 		free(tmppath);
1167 	}
1168 	return err ? err : unlock_err;
1169 }
1170 
1171 static const struct got_error *
1172 delete_packed_ref(struct got_reference *delref, struct got_repository *repo)
1173 {
1174 	const struct got_error *err = NULL, *unlock_err = NULL;
1175 	struct got_lockfile *lf = NULL;
1176 	FILE *f = NULL, *tmpf = NULL;
1177 	char *packed_refs_path, *tmppath = NULL;
1178 	struct got_reflist_head refs;
1179 	int found_delref = 0;
1180 
1181 	/* The packed-refs file does not cotain symbolic references. */
1182 	if (delref->flags & GOT_REF_IS_SYMBOLIC)
1183 		return got_error(GOT_ERR_BAD_REF_DATA);
1184 
1185 	SIMPLEQ_INIT(&refs);
1186 
1187 	packed_refs_path = got_repo_get_path_packed_refs(repo);
1188 	if (packed_refs_path == NULL)
1189 		return got_error_from_errno("got_repo_get_path_packed_refs");
1190 
1191 	err = got_opentemp_named(&tmppath, &tmpf, packed_refs_path);
1192 	if (err)
1193 		goto done;
1194 
1195 	if (delref->lf == NULL) {
1196 		err = got_lockfile_lock(&lf, packed_refs_path);
1197 		if (err)
1198 			goto done;
1199 	}
1200 
1201 	f = fopen(packed_refs_path, "r");
1202 	if (f == NULL) {
1203 		err = got_error_from_errno2("fopen", packed_refs_path);
1204 		goto done;
1205 	}
1206 	for (;;) {
1207 		char *line;
1208 		size_t len;
1209 		const char delim[3] = {'\0', '\0', '\0'};
1210 		struct got_reference *ref;
1211 		struct got_reflist_entry *new;
1212 
1213 		line = fparseln(f, &len, NULL, delim, 0);
1214 		if (line == NULL) {
1215 			if (feof(f))
1216 				break;
1217 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
1218 			goto done;
1219 		}
1220 		err = parse_packed_ref_line(&ref, NULL, line);
1221 		free(line);
1222 		if (err)
1223 			goto done;
1224 		if (ref == NULL)
1225 			continue;
1226 
1227 		if (strcmp(ref->ref.ref.name, delref->ref.ref.name) == 0 &&
1228 		    memcmp(ref->ref.ref.sha1, delref->ref.ref.sha1,
1229 		    sizeof(delref->ref.ref.sha1)) == 0) {
1230 			found_delref = 1;
1231 			got_ref_close(ref);
1232 			continue;
1233 		}
1234 
1235 		err = insert_ref(&new, &refs, ref, repo,
1236 		    got_ref_cmp_by_name, NULL);
1237 		if (err || new == NULL /* duplicate */)
1238 			got_ref_close(ref);
1239 		if (err)
1240 			goto done;
1241 	}
1242 
1243 	if (found_delref) {
1244 		struct got_reflist_entry *re;
1245 		size_t n;
1246 		struct stat sb;
1247 
1248 		n = fprintf(tmpf, "%s\n", GOT_PACKED_REFS_HEADER);
1249 		if (n != sizeof(GOT_PACKED_REFS_HEADER)) {
1250 			err = got_ferror(f, GOT_ERR_IO);
1251 			goto done;
1252 		}
1253 
1254 		SIMPLEQ_FOREACH(re, &refs, entry) {
1255 			uint8_t hex[SHA1_DIGEST_STRING_LENGTH];
1256 
1257 			if (got_sha1_digest_to_str(re->ref->ref.ref.sha1, hex,
1258 			    sizeof(hex)) == NULL) {
1259 				err = got_error(GOT_ERR_BAD_REF_DATA);
1260 				goto done;
1261 			}
1262 			n = fprintf(tmpf, "%s ", hex);
1263 			if (n != sizeof(hex)) {
1264 				err = got_ferror(f, GOT_ERR_IO);
1265 				goto done;
1266 			}
1267 			n = fprintf(tmpf, "%s\n", re->ref->ref.ref.name);
1268 			if (n != strlen(re->ref->ref.ref.name) + 1) {
1269 				err = got_ferror(f, GOT_ERR_IO);
1270 				goto done;
1271 			}
1272 		}
1273 
1274 		if (fflush(tmpf) != 0) {
1275 			err = got_error_from_errno("fflush");
1276 			goto done;
1277 		}
1278 
1279 		if (fstat(fileno(f), &sb) != 0) {
1280 			if (errno != ENOENT) {
1281 				err = got_error_from_errno2("fstat",
1282 				    packed_refs_path);
1283 				goto done;
1284 			}
1285 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
1286 		}
1287 
1288 		if (fchmod(fileno(tmpf), sb.st_mode) != 0) {
1289 			err = got_error_from_errno2("fchmod", tmppath);
1290 			goto done;
1291 		}
1292 
1293 		if (rename(tmppath, packed_refs_path) != 0) {
1294 			err = got_error_from_errno3("rename", tmppath,
1295 			    packed_refs_path);
1296 			goto done;
1297 		}
1298 	}
1299 done:
1300 	if (delref->lf == NULL && lf)
1301 		unlock_err = got_lockfile_unlock(lf);
1302 	if (f) {
1303 		if (fclose(f) != 0 && err == NULL)
1304 			err = got_error_from_errno("fclose");
1305 	}
1306 	if (tmpf) {
1307 		unlink(tmppath);
1308 		if (fclose(tmpf) != 0 && err == NULL)
1309 			err = got_error_from_errno("fclose");
1310 	}
1311 	free(tmppath);
1312 	free(packed_refs_path);
1313 	got_ref_list_free(&refs);
1314 	return err ? err : unlock_err;
1315 }
1316 
1317 static const struct got_error *
1318 delete_loose_ref(struct got_reference *ref, struct got_repository *repo)
1319 {
1320 	const struct got_error *err = NULL, *unlock_err = NULL;
1321 	const char *name = got_ref_get_name(ref);
1322 	char *path_refs = NULL, *path = NULL;
1323 	struct got_lockfile *lf = NULL;
1324 
1325 	path_refs = get_refs_dir_path(repo, name);
1326 	if (path_refs == NULL) {
1327 		err = got_error_from_errno2("get_refs_dir_path", name);
1328 		goto done;
1329 	}
1330 
1331 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1332 		err = got_error_from_errno("asprintf");
1333 		goto done;
1334 	}
1335 
1336 	if (ref->lf == NULL) {
1337 		err = got_lockfile_lock(&lf, path);
1338 		if (err)
1339 			goto done;
1340 	}
1341 
1342 	/* XXX: check if old content matches our expectations? */
1343 
1344 	if (unlink(path) != 0)
1345 		err = got_error_from_errno2("unlink", path);
1346 done:
1347 	if (ref->lf == NULL && lf)
1348 		unlock_err = got_lockfile_unlock(lf);
1349 
1350 	free(path_refs);
1351 	free(path);
1352 	return err ? err : unlock_err;
1353 }
1354 
1355 const struct got_error *
1356 got_ref_delete(struct got_reference *ref, struct got_repository *repo)
1357 {
1358 	const struct got_error *err = NULL;
1359 	struct got_reference *ref2;
1360 
1361 	if (ref->flags & GOT_REF_IS_PACKED) {
1362 		err = delete_packed_ref(ref, repo);
1363 		if (err)
1364 			return err;
1365 
1366 		err = got_ref_open(&ref2, repo, got_ref_get_name(ref), 0);
1367 		if (err) {
1368 			if (err->code == GOT_ERR_NOT_REF)
1369 				return NULL;
1370 			return err;
1371 		}
1372 
1373 		err = delete_loose_ref(ref2, repo);
1374 		got_ref_close(ref2);
1375 		return err;
1376 	} else {
1377 		err = delete_loose_ref(ref, repo);
1378 		if (err)
1379 			return err;
1380 
1381 		err = got_ref_open(&ref2, repo, got_ref_get_name(ref), 0);
1382 		if (err) {
1383 			if (err->code == GOT_ERR_NOT_REF)
1384 				return NULL;
1385 			return err;
1386 		}
1387 
1388 		err = delete_packed_ref(ref2, repo);
1389 		got_ref_close(ref2);
1390 		return err;
1391 	}
1392 }
1393 
1394 const struct got_error *
1395 got_ref_unlock(struct got_reference *ref)
1396 {
1397 	const struct got_error *err;
1398 	err = got_lockfile_unlock(ref->lf);
1399 	ref->lf = NULL;
1400 	return err;
1401 }