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Date:: Sun May 12 22:05:59 2019 UTC
Message:: fix leftover lockfiles from parse_ref_file()
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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 <sha1.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <util.h>
29 #include <zlib.h>
30 #include <time.h>
31 #include <libgen.h>
32 
33 #include "got_error.h"
34 #include "got_object.h"
35 #include "got_repository.h"
36 #include "got_reference.h"
37 #include "got_opentemp.h"
38 #include "got_path.h"
39 
40 #include "got_lib_sha1.h"
41 #include "got_lib_delta.h"
42 #include "got_lib_inflate.h"
43 #include "got_lib_object.h"
44 #include "got_lib_lockfile.h"
45 
46 #ifndef nitems
47 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
48 #endif
49 
50 #define GOT_REF_HEADS	"heads"
51 #define GOT_REF_TAGS	"tags"
52 #define GOT_REF_REMOTES	"remotes"
53 
54 /*
55  * We do not resolve tags yet, and don't yet care about sorting refs either,
56  * so packed-refs files we write contain a minimal header which disables all
57  * packed-refs "traits" supported by Git.
58  */
59 #define GOT_PACKED_REFS_HEADER	"# pack-refs with:"
60 
61 /* A symbolic reference. */
62 struct got_symref {
63 	char *name;
64 	char *ref;
65 };
66 
67 /* A non-symbolic reference (there is no better designation). */
68 struct got_ref {
69 	char *name;
70 	u_int8_t sha1[SHA1_DIGEST_LENGTH];
71 };
72 
73 /* A reference which points to an arbitrary object. */
74 struct got_reference {
75 	unsigned int flags;
76 #define GOT_REF_IS_SYMBOLIC	0x01
77 #define GOT_REF_IS_PACKED	0x02
78 
79 	union {
80 		struct got_ref ref;
81 		struct got_symref symref;
82 	} ref;
83 
84 	struct got_lockfile *lf;
85 };
86 
87 static const struct got_error *
88 alloc_ref(struct got_reference **ref, const char *name,
89     struct got_object_id *id, int flags)
90 {
91 	const struct got_error *err = NULL;
92 
93 	*ref = calloc(1, sizeof(**ref));
94 	if (*ref == NULL)
95 		return got_error_prefix_errno("calloc");
96 
97 	memcpy((*ref)->ref.ref.sha1, id->sha1, sizeof((*ref)->ref.ref.sha1));
98 	(*ref)->flags = flags;
99 	(*ref)->ref.ref.name = strdup(name);
100 	if ((*ref)->ref.ref.name == NULL) {
101 		err = got_error_prefix_errno("strdup");
102 		got_ref_close(*ref);
103 		*ref = NULL;
104 	}
105 	return err;
106 }
107 
108 static const struct got_error *
109 alloc_symref(struct got_reference **ref, const char *name,
110     const char *target_ref, int flags)
111 {
112 	const struct got_error *err = NULL;
113 
114 	*ref = calloc(1, sizeof(**ref));
115 	if (*ref == NULL)
116 		return got_error_prefix_errno("calloc");
117 
118 	(*ref)->flags = GOT_REF_IS_SYMBOLIC | flags;
119 	(*ref)->ref.symref.name = strdup(name);
120 	if ((*ref)->ref.symref.name == NULL) {
121 		err = got_error_prefix_errno("strdup");
122 		got_ref_close(*ref);
123 		*ref = NULL;
124 	}
125 	(*ref)->ref.symref.ref = strdup(target_ref);
126 	if ((*ref)->ref.symref.ref == NULL) {
127 		err = got_error_prefix_errno("strdup");
128 		got_ref_close(*ref);
129 		*ref = NULL;
130 	}
131 	return err;
132 }
133 
134 static const struct got_error *
135 parse_symref(struct got_reference **ref, const char *name, const char *line)
136 {
137 	if (line[0] == '\0')
138 		return got_error(GOT_ERR_BAD_REF_DATA);
139 
140 	return alloc_symref(ref, name, line, 0);
141 }
142 
143 static const struct got_error *
144 parse_ref_line(struct got_reference **ref, const char *name, const char *line)
145 {
146 	struct got_object_id id;
147 
148 	if (strncmp(line, "ref: ", 5) == 0) {
149 		line += 5;
150 		return parse_symref(ref, name, line);
151 	}
152 
153 	if (!got_parse_sha1_digest(id.sha1, line))
154 		return got_error(GOT_ERR_BAD_REF_DATA);
155 
156 	return alloc_ref(ref, name, &id, 0);
157 }
158 
159 static const struct got_error *
160 parse_ref_file(struct got_reference **ref, const char *name,
161     const char *abspath, int lock)
162 {
163 	const struct got_error *err = NULL;
164 	FILE *f;
165 	char *line;
166 	size_t len;
167 	const char delim[3] = {'\0', '\0', '\0'};
168 	struct got_lockfile *lf = NULL;
169 
170 	if (lock) {
171 		err = got_lockfile_lock(&lf, abspath);
172 		if (err)
173 			return (err);
174 	}
175 
176 	f = fopen(abspath, "rb");
177 	if (f == NULL) {
178 		if (lock)
179 			got_lockfile_unlock(lf);
180 		return NULL;
181 	}
182 
183 	line = fparseln(f, &len, NULL, delim, 0);
184 	if (line == NULL) {
185 		err = got_error(GOT_ERR_BAD_REF_DATA);
186 		if (lock)
187 			got_lockfile_unlock(lf);
188 		goto done;
189 	}
190 
191 	err = parse_ref_line(ref, name, line);
192 	if (lock) {
193 		if (err)
194 			got_lockfile_unlock(lf);
195 		else {
196 			if (*ref)
197 				(*ref)->lf = lf;
198 			else
199 				got_lockfile_unlock(lf);
200 		}
201 	}
202 done:
203 	free(line);
204 	if (fclose(f) != 0 && err == NULL) {
205 		err = got_error_prefix_errno("fclose");
206 		if (*ref) {
207 			if (lock)
208 				got_ref_unlock(*ref);
209 			got_ref_close(*ref);
210 			*ref = NULL;
211 		}
212 	}
213 	return err;
214 }
215 
216 static int
217 is_well_known_ref(const char *refname)
218 {
219 	return (strcmp(refname, GOT_REF_HEAD) == 0 ||
220 	    strcmp(refname, GOT_REF_ORIG_HEAD) == 0 ||
221 	    strcmp(refname, GOT_REF_MERGE_HEAD) == 0 ||
222 	    strcmp(refname, GOT_REF_FETCH_HEAD) == 0);
223 }
224 
225 static char *
226 get_refs_dir_path(struct got_repository *repo, const char *refname)
227 {
228 	if (is_well_known_ref(refname) || strncmp(refname, "refs/", 5) == 0)
229 		return strdup(got_repo_get_path_git_dir(repo));
230 
231 	return got_repo_get_path_refs(repo);
232 }
233 
234 static int
235 is_valid_ref_name(const char *name)
236 {
237 	const char *s, *slash, *seg;
238 	const char forbidden[] = { ' ', '~', '^', ':', '?', '*', '[' , '\\' };
239 	const char *forbidden_seq[] = { "//", "..", "@{" };
240 	const char *lfs = GOT_LOCKFILE_SUFFIX;
241 	const size_t lfs_len = sizeof(GOT_LOCKFILE_SUFFIX) - 1;
242 	int i;
243 
244 	if (name[0] == '@' && name[1] == '\0')
245 		return 0;
246 
247 	slash = strchr(name, '/');
248 	if (slash == NULL)
249 		return 0;
250 
251 	s = name;
252 	seg = s;
253 	if (seg[0] == '\0' || seg[0] == '.' || seg[0] == '/')
254 		return 0;
255 	while (*s) {
256 		for (i = 0; i < nitems(forbidden); i++) {
257 			if (*s == forbidden[i])
258 				return 0;
259 		}
260 		for (i = 0; i < nitems(forbidden_seq); i++) {
261 			if (s[0] == forbidden_seq[i][0] &&
262 			    s[1] == forbidden_seq[i][1])
263 				return 0;
264 		}
265 		if (iscntrl((unsigned char)s[0]))
266 			return 0;
267 		if (s[0] == '.' && s[1] == '\0')
268 			return 0;
269 		if (*s == '/') {
270 			const char *nextseg = s + 1;
271 			if (nextseg[0] == '\0' || nextseg[0] == '.' ||
272 			    nextseg[0] == '/')
273 				return 0;
274 			if (seg <= s - lfs_len &&
275 			    strncmp(s - lfs_len, lfs, lfs_len) == 0)
276 				return 0;
277 			seg = nextseg;
278 		}
279 		s++;
280 	}
281 
282 	if (seg <= s - lfs_len &&
283 	    strncmp(s - lfs_len, lfs, lfs_len) == 0)
284 		return 0;
285 
286 	return 1;
287 }
288 
289 const struct got_error *
290 got_ref_alloc(struct got_reference **ref, const char *name,
291     struct got_object_id *id)
292 {
293 	if (!is_valid_ref_name(name))
294 		return got_error(GOT_ERR_BAD_REF_NAME);
295 
296 	return alloc_ref(ref, name, id, 0);
297 }
298 
299 static const struct got_error *
300 parse_packed_ref_line(struct got_reference **ref, const char *abs_refname,
301     const char *line)
302 {
303 	struct got_object_id id;
304 	const char *name;
305 
306 	*ref = NULL;
307 
308 	if (line[0] == '#' || line[0] == '^')
309 		return NULL;
310 
311 	if (!got_parse_sha1_digest(id.sha1, line))
312 		return got_error(GOT_ERR_BAD_REF_DATA);
313 
314 	if (abs_refname) {
315 		if (strcmp(line + SHA1_DIGEST_STRING_LENGTH, abs_refname) != 0)
316 			return NULL;
317 		name = abs_refname;
318 	} else
319 		name = line + SHA1_DIGEST_STRING_LENGTH;
320 
321 	return alloc_ref(ref, name, &id, GOT_REF_IS_PACKED);
322 }
323 
324 static const struct got_error *
325 open_packed_ref(struct got_reference **ref, FILE *f, const char **subdirs,
326     int nsubdirs, const char *refname)
327 {
328 	const struct got_error *err = NULL;
329 	char *abs_refname;
330 	char *line;
331 	size_t len;
332 	const char delim[3] = {'\0', '\0', '\0'};
333 	int i, ref_is_absolute = (strncmp(refname, "refs/", 5) == 0);
334 
335 	*ref = NULL;
336 
337 	if (ref_is_absolute)
338 		abs_refname = (char *)refname;
339 	do {
340 		line = fparseln(f, &len, NULL, delim, 0);
341 		if (line == NULL) {
342 			if (feof(f))
343 				break;
344 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
345 			break;
346 		}
347 		for (i = 0; i < nsubdirs; i++) {
348 			if (!ref_is_absolute &&
349 			    asprintf(&abs_refname, "refs/%s/%s", subdirs[i],
350 			    refname) == -1)
351 				return got_error_prefix_errno("asprintf");
352 			err = parse_packed_ref_line(ref, abs_refname, line);
353 			if (!ref_is_absolute)
354 				free(abs_refname);
355 			if (err || *ref != NULL)
356 				break;
357 		}
358 		free(line);
359 		if (err)
360 			break;
361 	} while (*ref == NULL);
362 
363 	return err;
364 }
365 
366 static const struct got_error *
367 open_ref(struct got_reference **ref, const char *path_refs, const char *subdir,
368     const char *name, int lock)
369 {
370 	const struct got_error *err = NULL;
371 	char *path = NULL;
372 	char *normpath = NULL;
373 	char *absname = NULL;
374 	int ref_is_absolute = (strncmp(name, "refs/", 5) == 0);
375 	int ref_is_well_known = is_well_known_ref(name);
376 
377 	*ref = NULL;
378 
379 	if (ref_is_absolute || ref_is_well_known) {
380 		if (asprintf(&path, "%s/%s", path_refs, name) == -1)
381 			return got_error_prefix_errno("asprintf");
382 		absname = (char *)name;
383 	} else {
384 		if (asprintf(&path, "%s/%s%s%s", path_refs, subdir,
385 		    subdir[0] ? "/" : "", name) == -1)
386 			return got_error_prefix_errno("asprintf");
387 
388 		if (asprintf(&absname, "refs/%s%s%s",
389 		    subdir, subdir[0] ? "/" : "", name) == -1) {
390 			err = got_error_prefix_errno("asprintf");
391 			goto done;
392 		}
393 	}
394 
395 	normpath = got_path_normalize(path);
396 	if (normpath == NULL) {
397 		err = got_error_prefix_errno2("got_path_normalize", path);
398 		goto done;
399 	}
400 
401 	err = parse_ref_file(ref, absname, normpath, lock);
402 done:
403 	if (!ref_is_absolute && !ref_is_well_known)
404 		free(absname);
405 	free(path);
406 	free(normpath);
407 	return err;
408 }
409 
410 const struct got_error *
411 got_ref_open(struct got_reference **ref, struct got_repository *repo,
412    const char *refname, int lock)
413 {
414 	const struct got_error *err = NULL;
415 	char *path_refs = NULL;
416 	const char *subdirs[] = {
417 	    GOT_REF_HEADS, GOT_REF_TAGS, GOT_REF_REMOTES
418 	};
419 	int i, well_known = is_well_known_ref(refname);
420 	struct got_lockfile *lf = NULL;
421 
422 	*ref = NULL;
423 
424 	path_refs = get_refs_dir_path(repo, refname);
425 	if (path_refs == NULL) {
426 		err = got_error_prefix_errno2("get_refs_dir_path", refname);
427 		goto done;
428 	}
429 
430 	if (well_known) {
431 		err = open_ref(ref, path_refs, "", refname, lock);
432 	} else {
433 		char *packed_refs_path;
434 		FILE *f;
435 
436 		/* Search on-disk refs before packed refs! */
437 		for (i = 0; i < nitems(subdirs); i++) {
438 			err = open_ref(ref, path_refs, subdirs[i], refname,
439 			    lock);
440 			if (err || *ref)
441 				goto done;
442 		}
443 
444 		packed_refs_path = got_repo_get_path_packed_refs(repo);
445 		if (packed_refs_path == NULL) {
446 			err = got_error_prefix_errno(
447 			    "got_repo_get_path_packed_refs");
448 			goto done;
449 		}
450 
451 		if (lock) {
452 			err = got_lockfile_lock(&lf, packed_refs_path);
453 			if (err)
454 				goto done;
455 		}
456 		f = fopen(packed_refs_path, "rb");
457 		free(packed_refs_path);
458 		if (f != NULL) {
459 			err = open_packed_ref(ref, f, subdirs, nitems(subdirs),
460 			    refname);
461 			if (!err) {
462 				if (fclose(f) != 0) {
463 					err = got_error_prefix_errno("fclose");
464 					got_ref_close(*ref);
465 					*ref = NULL;
466 				} else
467 					(*ref)->lf = lf;
468 			}
469 		}
470 	}
471 done:
472 	if (!err && *ref == NULL)
473 		err = got_error_not_ref(refname);
474 	if (err && lf)
475 		got_lockfile_unlock(lf);
476 	free(path_refs);
477 	return err;
478 }
479 
480 void
481 got_ref_close(struct got_reference *ref)
482 {
483 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
484 		free(ref->ref.symref.name);
485 		free(ref->ref.symref.ref);
486 	} else
487 		free(ref->ref.ref.name);
488 	free(ref);
489 }
490 
491 struct got_reference *
492 got_ref_dup(struct got_reference *ref)
493 {
494 	struct got_reference *ret;
495 
496 	ret = calloc(1, sizeof(*ret));
497 	if (ret == NULL)
498 		return NULL;
499 
500 	ret->flags = ref->flags;
501 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
502 		ret->ref.symref.name = strdup(ref->ref.symref.name);
503 		if (ret->ref.symref.name == NULL) {
504 			free(ret);
505 			return NULL;
506 		}
507 		ret->ref.symref.ref = strdup(ref->ref.symref.ref);
508 		if (ret->ref.symref.ref == NULL) {
509 			free(ret->ref.symref.name);
510 			free(ret);
511 			return NULL;
512 		}
513 	} else {
514 		ref->ref.ref.name = strdup(ref->ref.ref.name);
515 		if (ref->ref.ref.name == NULL) {
516 			free(ret);
517 			return NULL;
518 		}
519 		memcpy(ret->ref.ref.sha1, ref->ref.ref.sha1,
520 		    sizeof(ret->ref.ref.sha1));
521 	}
522 
523 	return ret;
524 }
525 
526 static const struct got_error *
527 resolve_symbolic_ref(struct got_reference **resolved,
528     struct got_repository *repo, struct got_reference *ref)
529 {
530 	struct got_reference *nextref;
531 	const struct got_error *err;
532 
533 	err = got_ref_open(&nextref, repo, ref->ref.symref.ref, 0);
534 	if (err)
535 		return err;
536 
537 	if (nextref->flags & GOT_REF_IS_SYMBOLIC)
538 		err = resolve_symbolic_ref(resolved, repo, nextref);
539 	else
540 		*resolved = got_ref_dup(nextref);
541 
542 	got_ref_close(nextref);
543 	return err;
544 }
545 
546 const struct got_error *
547 got_ref_resolve(struct got_object_id **id, struct got_repository *repo,
548     struct got_reference *ref)
549 {
550 	const struct got_error *err;
551 
552 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
553 		struct got_reference *resolved = NULL;
554 		err = resolve_symbolic_ref(&resolved, repo, ref);
555 		if (err == NULL)
556 			err = got_ref_resolve(id, repo, resolved);
557 		if (resolved)
558 			got_ref_close(resolved);
559 		return err;
560 	}
561 
562 	*id = calloc(1, sizeof(**id));
563 	if (*id == NULL)
564 		return got_error_prefix_errno("calloc");
565 	memcpy((*id)->sha1, ref->ref.ref.sha1, sizeof((*id)->sha1));
566 	return NULL;
567 }
568 
569 char *
570 got_ref_to_str(struct got_reference *ref)
571 {
572 	char *str;
573 
574 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
575 		return strdup(ref->ref.symref.ref);
576 
577 	str = malloc(SHA1_DIGEST_STRING_LENGTH);
578 	if (str == NULL)
579 		return NULL;
580 
581 	if (got_sha1_digest_to_str(ref->ref.ref.sha1, str,
582 	    SHA1_DIGEST_STRING_LENGTH) == NULL) {
583 		free(str);
584 		return NULL;
585 	}
586 
587 	return str;
588 }
589 
590 const char *
591 got_ref_get_name(struct got_reference *ref)
592 {
593 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
594 		return ref->ref.symref.name;
595 
596 	return ref->ref.ref.name;
597 }
598 
599 static const struct got_error *
600 insert_ref(struct got_reflist_entry **newp, struct got_reflist_head *refs,
601     struct got_reference *ref, struct got_repository *repo)
602 {
603 	const struct got_error *err;
604 	struct got_object_id *id;
605 	struct got_reflist_entry *new, *re, *prev = NULL;
606 	int cmp;
607 
608 	*newp = NULL;
609 
610 	err = got_ref_resolve(&id, repo, ref);
611 	if (err)
612 		return err;
613 
614 	new = malloc(sizeof(*new));
615 	if (new == NULL) {
616 		free(id);
617 		return got_error_prefix_errno("malloc");
618 	}
619 	new->ref = ref;
620 	new->id = id;
621 	*newp = new;
622 
623 	/*
624 	 * We must de-duplicate entries on insert because packed-refs may
625 	 * contain redundant entries. On-disk refs take precedence.
626 	 * This code assumes that on-disk revs are read before packed-refs.
627 	 * We're iterating the list anyway, so insert elements sorted by name.
628 	 */
629 	re = SIMPLEQ_FIRST(refs);
630 	while (re) {
631 		cmp = got_path_cmp(got_ref_get_name(re->ref),
632 		    got_ref_get_name(new->ref));
633 		if (cmp == 0) {
634 			/* duplicate */
635 			free(new->id);
636 			free(new);
637 			*newp = NULL;
638 			return NULL;
639 		} else if (cmp > 0) {
640 			if (prev)
641 				SIMPLEQ_INSERT_AFTER(refs, prev, new, entry);
642 			else
643 				SIMPLEQ_INSERT_HEAD(refs, new, entry);
644 			return NULL;
645 		} else {
646 			prev = re;
647 			re = SIMPLEQ_NEXT(re, entry);
648 		}
649 	}
650 
651 	SIMPLEQ_INSERT_TAIL(refs, new, entry);
652 	return NULL;
653 }
654 
655 static const struct got_error *
656 gather_on_disk_refs(struct got_reflist_head *refs, const char *path_refs,
657     const char *subdir, struct got_repository *repo)
658 {
659 	const struct got_error *err = NULL;
660 	DIR *d = NULL;
661 	char *path_subdir;
662 
663 	if (asprintf(&path_subdir, "%s/%s", path_refs, subdir) == -1)
664 		return got_error_prefix_errno("asprintf");
665 
666 	d = opendir(path_subdir);
667 	if (d == NULL)
668 		goto done;
669 
670 	for (;;) {
671 		struct dirent *dent;
672 		struct got_reference *ref;
673 		char *child;
674 
675 		dent = readdir(d);
676 		if (dent == NULL)
677 			break;
678 
679 		if (strcmp(dent->d_name, ".") == 0 ||
680 		    strcmp(dent->d_name, "..") == 0)
681 			continue;
682 
683 		switch (dent->d_type) {
684 		case DT_REG:
685 			err = open_ref(&ref, path_refs, subdir, dent->d_name,
686 			    0);
687 			if (err)
688 				goto done;
689 			if (ref) {
690 				struct got_reflist_entry *new;
691 				err = insert_ref(&new, refs, ref, repo);
692 				if (err || new == NULL /* duplicate */)
693 					got_ref_close(ref);
694 				if (err)
695 					goto done;
696 			}
697 			break;
698 		case DT_DIR:
699 			if (asprintf(&child, "%s%s%s", subdir,
700 			    subdir[0] == '\0' ? "" : "/", dent->d_name) == -1) {
701 				err = got_error_prefix_errno("asprintf");
702 				break;
703 			}
704 			err = gather_on_disk_refs(refs, path_refs, child, repo);
705 			free(child);
706 			break;
707 		default:
708 			break;
709 		}
710 	}
711 done:
712 	if (d)
713 		closedir(d);
714 	free(path_subdir);
715 	return err;
716 }
717 
718 const struct got_error *
719 got_ref_list(struct got_reflist_head *refs, struct got_repository *repo)
720 {
721 	const struct got_error *err;
722 	char *packed_refs_path, *path_refs = NULL;
723 	FILE *f = NULL;
724 	struct got_reference *ref;
725 	struct got_reflist_entry *new;
726 
727 	/* HEAD ref should always exist. */
728 	path_refs = get_refs_dir_path(repo, GOT_REF_HEAD);
729 	if (path_refs == NULL) {
730 		err = got_error_prefix_errno("get_refs_dir_path");
731 		goto done;
732 	}
733 	err = open_ref(&ref, path_refs, "", GOT_REF_HEAD, 0);
734 	if (err)
735 		goto done;
736 	err = insert_ref(&new, refs, ref, repo);
737 	if (err || new == NULL /* duplicate */)
738 		got_ref_close(ref);
739 	if (err)
740 		goto done;
741 
742 	/* Gather on-disk refs before parsing packed-refs. */
743 	free(path_refs);
744 	path_refs = get_refs_dir_path(repo, "");
745 	if (path_refs == NULL) {
746 		err = got_error_prefix_errno("get_refs_dir_path");
747 		goto done;
748 	}
749 	err = gather_on_disk_refs(refs, path_refs, "", repo);
750 	if (err)
751 		goto done;
752 
753 	/*
754 	 * The packed-refs file may contain redundant entries, in which
755 	 * case on-disk refs take precedence.
756 	 */
757 	packed_refs_path = got_repo_get_path_packed_refs(repo);
758 	if (packed_refs_path == NULL) {
759 		err = got_error_prefix_errno("got_repo_get_path_packed_refs");
760 		goto done;
761 	}
762 
763 	f = fopen(packed_refs_path, "r");
764 	free(packed_refs_path);
765 	if (f) {
766 		char *line;
767 		size_t len;
768 		const char delim[3] = {'\0', '\0', '\0'};
769 		for (;;) {
770 			line = fparseln(f, &len, NULL, delim, 0);
771 			if (line == NULL) {
772 				if (feof(f))
773 					break;
774 				err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
775 				goto done;
776 			}
777 			err = parse_packed_ref_line(&ref, NULL, line);
778 			free(line);
779 			if (err)
780 				goto done;
781 			if (ref) {
782 				err = insert_ref(&new, refs, ref, repo);
783 				if (err || new == NULL /* duplicate */)
784 					got_ref_close(ref);
785 				if (err)
786 					goto done;
787 			}
788 		}
789 	}
790 done:
791 	free(path_refs);
792 	if (f && fclose(f) != 0 && err == NULL)
793 		err = got_error_prefix_errno("fclose");
794 	return err;
795 }
796 
797 void
798 got_ref_list_free(struct got_reflist_head *refs)
799 {
800 	struct got_reflist_entry *re;
801 
802 	while (!SIMPLEQ_EMPTY(refs)) {
803 		re = SIMPLEQ_FIRST(refs);
804 		SIMPLEQ_REMOVE_HEAD(refs, entry);
805 		got_ref_close(re->ref);
806 		free(re->id);
807 		free(re);
808 	}
809 
810 }
811 
812 int
813 got_ref_is_symbolic(struct got_reference *ref)
814 {
815 	return (ref->flags & GOT_REF_IS_SYMBOLIC);
816 }
817 
818 const struct got_error *
819 got_ref_change_ref(struct got_reference *ref, struct got_object_id *id)
820 {
821 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
822 		return got_error(GOT_ERR_BAD_REF_TYPE);
823 
824 	memcpy(ref->ref.ref.sha1, id->sha1, sizeof(ref->ref.ref.sha1));
825 	return NULL;
826 }
827 
828 const struct got_error *
829 got_ref_change_symref(struct got_reference *ref, char *refname)
830 {
831 	char *new_name;
832 
833 	if ((ref->flags & GOT_REF_IS_SYMBOLIC) == 0)
834 		return got_error(GOT_ERR_BAD_REF_TYPE);
835 
836 	new_name = strdup(refname);
837 	if (new_name == NULL)
838 		return got_error_prefix_errno("strdup");
839 
840 	free(ref->ref.symref.name);
841 	ref->ref.symref.name = new_name;
842 	return NULL;
843 }
844 
845 const struct got_error *
846 got_ref_write(struct got_reference *ref, struct got_repository *repo)
847 {
848 	const struct got_error *err = NULL, *unlock_err = NULL;
849 	const char *name = got_ref_get_name(ref);
850 	char *path_refs = NULL, *path = NULL, *tmppath = NULL;
851 	struct got_lockfile *lf = NULL;
852 	FILE *f = NULL;
853 	size_t n;
854 	struct stat sb;
855 
856 	path_refs = get_refs_dir_path(repo, name);
857 	if (path_refs == NULL) {
858 		err = got_error_prefix_errno2("get_refs_dir_path", name);
859 		goto done;
860 	}
861 
862 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
863 		err = got_error_prefix_errno("asprintf");
864 		goto done;
865 	}
866 
867 	err = got_opentemp_named(&tmppath, &f, path);
868 	if (err) {
869 		char *parent;
870 		if (!(err->code == GOT_ERR_ERRNO && errno == ENOENT))
871 			goto done;
872 		err = got_path_dirname(&parent, path);
873 		if (err)
874 			goto done;
875 		err = got_path_mkdir(parent);
876 		free(parent);
877 		if (err)
878 			goto done;
879 		err = got_opentemp_named(&tmppath, &f, path);
880 		if (err)
881 			goto done;
882 	}
883 
884 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
885 		n = fprintf(f, "ref: %s\n", ref->ref.symref.ref);
886 		if (n != strlen(ref->ref.symref.ref) + 6) {
887 			err = got_ferror(f, GOT_ERR_IO);
888 			goto done;
889 		}
890 	} else {
891 		char hex[SHA1_DIGEST_STRING_LENGTH];
892 		if (got_sha1_digest_to_str(ref->ref.ref.sha1, hex,
893 		    sizeof(hex)) == NULL) {
894 			err = got_error(GOT_ERR_BAD_REF_DATA);
895 			goto done;
896 		}
897 		n = fprintf(f, "%s\n", hex);
898 		if (n != sizeof(hex)) {
899 			err = got_ferror(f, GOT_ERR_IO);
900 			goto done;
901 		}
902 	}
903 
904 	if (ref->lf == NULL) {
905 		err = got_lockfile_lock(&lf, path);
906 		if (err)
907 			goto done;
908 	}
909 
910 	/* XXX: check if old content matches our expectations? */
911 
912 	if (stat(path, &sb) != 0) {
913 		if (errno != ENOENT) {
914 			err = got_error_prefix_errno2("stat", path);
915 			goto done;
916 		}
917 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
918 	}
919 
920 	if (rename(tmppath, path) != 0) {
921 		err = got_error_prefix_errno3("rename", tmppath, path);
922 		goto done;
923 	}
924 	free(tmppath);
925 	tmppath = NULL;
926 
927 	if (chmod(path, sb.st_mode) != 0) {
928 		err = got_error_prefix_errno2("chmod", path);
929 		goto done;
930 	}
931 done:
932 	if (ref->lf == NULL && lf)
933 		unlock_err = got_lockfile_unlock(lf);
934 	if (f) {
935 		if (fclose(f) != 0 && err == NULL)
936 			err = got_error_prefix_errno("fclose");
937 	}
938 	free(path_refs);
939 	free(path);
940 	if (tmppath) {
941 		if (unlink(tmppath) != 0 && err == NULL)
942 			err = got_error_prefix_errno2("unlink", tmppath);
943 		free(tmppath);
944 	}
945 	return err ? err : unlock_err;
946 }
947 
948 static const struct got_error *
949 delete_packed_ref(struct got_reference *delref, struct got_repository *repo)
950 {
951 	const struct got_error *err = NULL, *unlock_err = NULL;
952 	struct got_lockfile *lf = NULL;
953 	FILE *f = NULL, *tmpf = NULL;
954 	char *packed_refs_path, *tmppath = NULL;
955 	struct got_reflist_head refs;
956 	int found_delref = 0;
957 
958 	/* The packed-refs file does not cotain symbolic references. */
959 	if (delref->flags & GOT_REF_IS_SYMBOLIC)
960 		return got_error(GOT_ERR_BAD_REF_DATA);
961 
962 	SIMPLEQ_INIT(&refs);
963 
964 	packed_refs_path = got_repo_get_path_packed_refs(repo);
965 	if (packed_refs_path == NULL)
966 		return got_error_prefix_errno("got_repo_get_path_packed_refs");
967 
968 	err = got_opentemp_named(&tmppath, &tmpf, packed_refs_path);
969 	if (err)
970 		goto done;
971 
972 	if (delref->lf == NULL) {
973 		err = got_lockfile_lock(&lf, packed_refs_path);
974 		if (err)
975 			goto done;
976 	}
977 
978 	f = fopen(packed_refs_path, "r");
979 	if (f == NULL) {
980 		err = got_error_prefix_errno2("fopen", packed_refs_path);
981 		goto done;
982 	}
983 	for (;;) {
984 		char *line;
985 		size_t len;
986 		const char delim[3] = {'\0', '\0', '\0'};
987 		struct got_reference *ref;
988 		struct got_reflist_entry *new;
989 
990 		line = fparseln(f, &len, NULL, delim, 0);
991 		if (line == NULL) {
992 			if (feof(f))
993 				break;
994 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
995 			goto done;
996 		}
997 		err = parse_packed_ref_line(&ref, NULL, line);
998 		free(line);
999 		if (err)
1000 			goto done;
1001 		if (ref == NULL)
1002 			continue;
1003 
1004 		if (strcmp(ref->ref.ref.name, delref->ref.ref.name) == 0 &&
1005 		    memcmp(ref->ref.ref.sha1, delref->ref.ref.sha1,
1006 		    sizeof(delref->ref.ref.sha1)) == 0) {
1007 			found_delref = 1;
1008 			got_ref_close(ref);
1009 			continue;
1010 		}
1011 
1012 		err = insert_ref(&new, &refs, ref, repo);
1013 		if (err || new == NULL /* duplicate */)
1014 			got_ref_close(ref);
1015 		if (err)
1016 			goto done;
1017 	}
1018 
1019 	if (found_delref) {
1020 		struct got_reflist_entry *re;
1021 		size_t n;
1022 		struct stat sb;
1023 
1024 		n = fprintf(tmpf, "%s\n", GOT_PACKED_REFS_HEADER);
1025 		if (n != sizeof(GOT_PACKED_REFS_HEADER)) {
1026 			err = got_ferror(f, GOT_ERR_IO);
1027 			goto done;
1028 		}
1029 
1030 		SIMPLEQ_FOREACH(re, &refs, entry) {
1031 			uint8_t hex[SHA1_DIGEST_STRING_LENGTH];
1032 
1033 			if (got_sha1_digest_to_str(re->ref->ref.ref.sha1, hex,
1034 			    sizeof(hex)) == NULL) {
1035 				err = got_error(GOT_ERR_BAD_REF_DATA);
1036 				goto done;
1037 			}
1038 			n = fprintf(tmpf, "%s ", hex);
1039 			if (n != sizeof(hex)) {
1040 				err = got_ferror(f, GOT_ERR_IO);
1041 				goto done;
1042 			}
1043 			n = fprintf(tmpf, "%s\n", re->ref->ref.ref.name);
1044 			if (n != strlen(re->ref->ref.ref.name) + 1) {
1045 				err = got_ferror(f, GOT_ERR_IO);
1046 				goto done;
1047 			}
1048 		}
1049 
1050 		if (fflush(tmpf) != 0) {
1051 			err = got_error_prefix_errno("fflush");
1052 			goto done;
1053 		}
1054 
1055 		if (stat(packed_refs_path, &sb) != 0) {
1056 			if (errno != ENOENT) {
1057 				err = got_error_prefix_errno2("stat",
1058 				    packed_refs_path);
1059 				goto done;
1060 			}
1061 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
1062 		}
1063 
1064 		if (rename(tmppath, packed_refs_path) != 0) {
1065 			err = got_error_prefix_errno3("rename", tmppath,
1066 			    packed_refs_path);
1067 			goto done;
1068 		}
1069 
1070 		if (chmod(packed_refs_path, sb.st_mode) != 0) {
1071 			err = got_error_prefix_errno2("chmod",
1072 			    packed_refs_path);
1073 			goto done;
1074 		}
1075 	}
1076 done:
1077 	if (delref->lf == NULL && lf)
1078 		unlock_err = got_lockfile_unlock(lf);
1079 	if (f) {
1080 		if (fclose(f) != 0 && err == NULL)
1081 			err = got_error_prefix_errno("fclose");
1082 	}
1083 	if (tmpf) {
1084 		unlink(tmppath);
1085 		if (fclose(tmpf) != 0 && err == NULL)
1086 			err = got_error_prefix_errno("fclose");
1087 	}
1088 	free(tmppath);
1089 	free(packed_refs_path);
1090 	got_ref_list_free(&refs);
1091 	return err ? err : unlock_err;
1092 }
1093 
1094 const struct got_error *
1095 got_ref_delete(struct got_reference *ref, struct got_repository *repo)
1096 {
1097 	const struct got_error *err = NULL, *unlock_err = NULL;
1098 	const char *name = got_ref_get_name(ref);
1099 	char *path_refs = NULL, *path = NULL;
1100 	struct got_lockfile *lf = NULL;
1101 
1102 	if (ref->flags & GOT_REF_IS_PACKED)
1103 		return delete_packed_ref(ref, repo);
1104 
1105 	path_refs = get_refs_dir_path(repo, name);
1106 	if (path_refs == NULL) {
1107 		err = got_error_prefix_errno2("get_refs_dir_path", name);
1108 		goto done;
1109 	}
1110 
1111 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1112 		err = got_error_prefix_errno("asprintf");
1113 		goto done;
1114 	}
1115 
1116 	if (ref->lf == NULL) {
1117 		err = got_lockfile_lock(&lf, path);
1118 		if (err)
1119 			goto done;
1120 	}
1121 
1122 	/* XXX: check if old content matches our expectations? */
1123 
1124 	if (unlink(path) != 0)
1125 		err = got_error_prefix_errno2("unlink", path);
1126 done:
1127 	if (ref->lf == NULL && lf)
1128 		unlock_err = got_lockfile_unlock(lf);
1129 
1130 	free(path_refs);
1131 	free(path);
1132 	return err ? err : unlock_err;
1133 }
1134 
1135 const struct got_error *
1136 got_ref_unlock(struct got_reference *ref)
1137 {
1138 	const struct got_error *err;
1139 	err = got_lockfile_unlock(ref->lf);
1140 	ref->lf = NULL;
1141 	return err;
1142 }