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Date:: Wed Jul 10 16:08:47 2019 UTC
Message:: introduce got_ref_alloc_symref() and got_ref_get_symref_target()
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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_from_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_from_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_from_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_from_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_from_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_from_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 const struct got_error *
300 got_ref_alloc_symref(struct got_reference **ref, const char *name,
301 	struct got_reference *target_ref)
302 {
303 	if (!is_valid_ref_name(name))
304 		return got_error(GOT_ERR_BAD_REF_NAME);
305 
306 	return alloc_symref(ref, name, got_ref_get_name(target_ref), 0);
307 }
308 
309 static const struct got_error *
310 parse_packed_ref_line(struct got_reference **ref, const char *abs_refname,
311     const char *line)
312 {
313 	struct got_object_id id;
314 	const char *name;
315 
316 	*ref = NULL;
317 
318 	if (line[0] == '#' || line[0] == '^')
319 		return NULL;
320 
321 	if (!got_parse_sha1_digest(id.sha1, line))
322 		return got_error(GOT_ERR_BAD_REF_DATA);
323 
324 	if (abs_refname) {
325 		if (strcmp(line + SHA1_DIGEST_STRING_LENGTH, abs_refname) != 0)
326 			return NULL;
327 		name = abs_refname;
328 	} else
329 		name = line + SHA1_DIGEST_STRING_LENGTH;
330 
331 	return alloc_ref(ref, name, &id, GOT_REF_IS_PACKED);
332 }
333 
334 static const struct got_error *
335 open_packed_ref(struct got_reference **ref, FILE *f, const char **subdirs,
336     int nsubdirs, const char *refname)
337 {
338 	const struct got_error *err = NULL;
339 	char *abs_refname;
340 	char *line;
341 	size_t len;
342 	const char delim[3] = {'\0', '\0', '\0'};
343 	int i, ref_is_absolute = (strncmp(refname, "refs/", 5) == 0);
344 
345 	*ref = NULL;
346 
347 	if (ref_is_absolute)
348 		abs_refname = (char *)refname;
349 	do {
350 		line = fparseln(f, &len, NULL, delim, 0);
351 		if (line == NULL) {
352 			if (feof(f))
353 				break;
354 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
355 			break;
356 		}
357 		for (i = 0; i < nsubdirs; i++) {
358 			if (!ref_is_absolute &&
359 			    asprintf(&abs_refname, "refs/%s/%s", subdirs[i],
360 			    refname) == -1)
361 				return got_error_from_errno("asprintf");
362 			err = parse_packed_ref_line(ref, abs_refname, line);
363 			if (!ref_is_absolute)
364 				free(abs_refname);
365 			if (err || *ref != NULL)
366 				break;
367 		}
368 		free(line);
369 		if (err)
370 			break;
371 	} while (*ref == NULL);
372 
373 	return err;
374 }
375 
376 static const struct got_error *
377 open_ref(struct got_reference **ref, const char *path_refs, const char *subdir,
378     const char *name, int lock)
379 {
380 	const struct got_error *err = NULL;
381 	char *path = NULL;
382 	char *normpath = NULL;
383 	char *absname = NULL;
384 	int ref_is_absolute = (strncmp(name, "refs/", 5) == 0);
385 	int ref_is_well_known = is_well_known_ref(name);
386 
387 	*ref = NULL;
388 
389 	if (ref_is_absolute || ref_is_well_known) {
390 		if (asprintf(&path, "%s/%s", path_refs, name) == -1)
391 			return got_error_from_errno("asprintf");
392 		absname = (char *)name;
393 	} else {
394 		if (asprintf(&path, "%s/%s%s%s", path_refs, subdir,
395 		    subdir[0] ? "/" : "", name) == -1)
396 			return got_error_from_errno("asprintf");
397 
398 		if (asprintf(&absname, "refs/%s%s%s",
399 		    subdir, subdir[0] ? "/" : "", name) == -1) {
400 			err = got_error_from_errno("asprintf");
401 			goto done;
402 		}
403 	}
404 
405 	normpath = got_path_normalize(path);
406 	if (normpath == NULL) {
407 		if (errno == ENOENT)
408 			err = NULL;
409 		else
410 			err = got_error_from_errno2("got_path_normalize", path);
411 		goto done;
412 	}
413 
414 	err = parse_ref_file(ref, absname, normpath, lock);
415 done:
416 	if (!ref_is_absolute && !ref_is_well_known)
417 		free(absname);
418 	free(path);
419 	free(normpath);
420 	return err;
421 }
422 
423 const struct got_error *
424 got_ref_open(struct got_reference **ref, struct got_repository *repo,
425    const char *refname, int lock)
426 {
427 	const struct got_error *err = NULL;
428 	char *path_refs = NULL;
429 	const char *subdirs[] = {
430 	    GOT_REF_HEADS, GOT_REF_TAGS, GOT_REF_REMOTES
431 	};
432 	int i, well_known = is_well_known_ref(refname);
433 	struct got_lockfile *lf = NULL;
434 
435 	*ref = NULL;
436 
437 	path_refs = get_refs_dir_path(repo, refname);
438 	if (path_refs == NULL) {
439 		err = got_error_from_errno2("get_refs_dir_path", refname);
440 		goto done;
441 	}
442 
443 	if (well_known) {
444 		err = open_ref(ref, path_refs, "", refname, lock);
445 	} else {
446 		char *packed_refs_path;
447 		FILE *f;
448 
449 		/* Search on-disk refs before packed refs! */
450 		for (i = 0; i < nitems(subdirs); i++) {
451 			err = open_ref(ref, path_refs, subdirs[i], refname,
452 			    lock);
453 			if (err || *ref)
454 				goto done;
455 		}
456 
457 		packed_refs_path = got_repo_get_path_packed_refs(repo);
458 		if (packed_refs_path == NULL) {
459 			err = got_error_from_errno(
460 			    "got_repo_get_path_packed_refs");
461 			goto done;
462 		}
463 
464 		if (lock) {
465 			err = got_lockfile_lock(&lf, packed_refs_path);
466 			if (err)
467 				goto done;
468 		}
469 		f = fopen(packed_refs_path, "rb");
470 		free(packed_refs_path);
471 		if (f != NULL) {
472 			err = open_packed_ref(ref, f, subdirs, nitems(subdirs),
473 			    refname);
474 			if (!err) {
475 				if (fclose(f) != 0) {
476 					err = got_error_from_errno("fclose");
477 					got_ref_close(*ref);
478 					*ref = NULL;
479 				} else if (*ref)
480 					(*ref)->lf = lf;
481 			}
482 		}
483 	}
484 done:
485 	if (!err && *ref == NULL)
486 		err = got_error_not_ref(refname);
487 	if (err && lf)
488 		got_lockfile_unlock(lf);
489 	free(path_refs);
490 	return err;
491 }
492 
493 void
494 got_ref_close(struct got_reference *ref)
495 {
496 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
497 		free(ref->ref.symref.name);
498 		free(ref->ref.symref.ref);
499 	} else
500 		free(ref->ref.ref.name);
501 	free(ref);
502 }
503 
504 struct got_reference *
505 got_ref_dup(struct got_reference *ref)
506 {
507 	struct got_reference *ret;
508 
509 	ret = calloc(1, sizeof(*ret));
510 	if (ret == NULL)
511 		return NULL;
512 
513 	ret->flags = ref->flags;
514 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
515 		ret->ref.symref.name = strdup(ref->ref.symref.name);
516 		if (ret->ref.symref.name == NULL) {
517 			free(ret);
518 			return NULL;
519 		}
520 		ret->ref.symref.ref = strdup(ref->ref.symref.ref);
521 		if (ret->ref.symref.ref == NULL) {
522 			free(ret->ref.symref.name);
523 			free(ret);
524 			return NULL;
525 		}
526 	} else {
527 		ref->ref.ref.name = strdup(ref->ref.ref.name);
528 		if (ref->ref.ref.name == NULL) {
529 			free(ret);
530 			return NULL;
531 		}
532 		memcpy(ret->ref.ref.sha1, ref->ref.ref.sha1,
533 		    sizeof(ret->ref.ref.sha1));
534 	}
535 
536 	return ret;
537 }
538 
539 static const struct got_error *
540 resolve_symbolic_ref(struct got_reference **resolved,
541     struct got_repository *repo, struct got_reference *ref)
542 {
543 	struct got_reference *nextref;
544 	const struct got_error *err;
545 
546 	err = got_ref_open(&nextref, repo, ref->ref.symref.ref, 0);
547 	if (err)
548 		return err;
549 
550 	if (nextref->flags & GOT_REF_IS_SYMBOLIC)
551 		err = resolve_symbolic_ref(resolved, repo, nextref);
552 	else
553 		*resolved = got_ref_dup(nextref);
554 
555 	got_ref_close(nextref);
556 	return err;
557 }
558 
559 const struct got_error *
560 got_ref_resolve(struct got_object_id **id, struct got_repository *repo,
561     struct got_reference *ref)
562 {
563 	const struct got_error *err;
564 
565 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
566 		struct got_reference *resolved = NULL;
567 		err = resolve_symbolic_ref(&resolved, repo, ref);
568 		if (err == NULL)
569 			err = got_ref_resolve(id, repo, resolved);
570 		if (resolved)
571 			got_ref_close(resolved);
572 		return err;
573 	}
574 
575 	*id = calloc(1, sizeof(**id));
576 	if (*id == NULL)
577 		return got_error_from_errno("calloc");
578 	memcpy((*id)->sha1, ref->ref.ref.sha1, sizeof((*id)->sha1));
579 	return NULL;
580 }
581 
582 char *
583 got_ref_to_str(struct got_reference *ref)
584 {
585 	char *str;
586 
587 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
588 		return strdup(ref->ref.symref.ref);
589 
590 	str = malloc(SHA1_DIGEST_STRING_LENGTH);
591 	if (str == NULL)
592 		return NULL;
593 
594 	if (got_sha1_digest_to_str(ref->ref.ref.sha1, str,
595 	    SHA1_DIGEST_STRING_LENGTH) == NULL) {
596 		free(str);
597 		return NULL;
598 	}
599 
600 	return str;
601 }
602 
603 const char *
604 got_ref_get_name(struct got_reference *ref)
605 {
606 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
607 		return ref->ref.symref.name;
608 
609 	return ref->ref.ref.name;
610 }
611 
612 const char *
613 got_ref_get_symref_target(struct got_reference *ref)
614 {
615 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
616 		return ref->ref.symref.ref;
617 
618 	return NULL;
619 }
620 
621 static const struct got_error *
622 insert_ref(struct got_reflist_entry **newp, struct got_reflist_head *refs,
623     struct got_reference *ref, struct got_repository *repo)
624 {
625 	const struct got_error *err;
626 	struct got_object_id *id;
627 	struct got_reflist_entry *new, *re, *prev = NULL;
628 	int cmp;
629 
630 	*newp = NULL;
631 
632 	err = got_ref_resolve(&id, repo, ref);
633 	if (err)
634 		return err;
635 
636 	new = malloc(sizeof(*new));
637 	if (new == NULL) {
638 		free(id);
639 		return got_error_from_errno("malloc");
640 	}
641 	new->ref = ref;
642 	new->id = id;
643 	*newp = new;
644 
645 	/*
646 	 * We must de-duplicate entries on insert because packed-refs may
647 	 * contain redundant entries. On-disk refs take precedence.
648 	 * This code assumes that on-disk revs are read before packed-refs.
649 	 * We're iterating the list anyway, so insert elements sorted by name.
650 	 */
651 	re = SIMPLEQ_FIRST(refs);
652 	while (re) {
653 		cmp = got_path_cmp(got_ref_get_name(re->ref),
654 		    got_ref_get_name(new->ref));
655 		if (cmp == 0) {
656 			/* duplicate */
657 			free(new->id);
658 			free(new);
659 			*newp = NULL;
660 			return NULL;
661 		} else if (cmp > 0) {
662 			if (prev)
663 				SIMPLEQ_INSERT_AFTER(refs, prev, new, entry);
664 			else
665 				SIMPLEQ_INSERT_HEAD(refs, new, entry);
666 			return NULL;
667 		} else {
668 			prev = re;
669 			re = SIMPLEQ_NEXT(re, entry);
670 		}
671 	}
672 
673 	SIMPLEQ_INSERT_TAIL(refs, new, entry);
674 	return NULL;
675 }
676 
677 static const struct got_error *
678 gather_on_disk_refs(struct got_reflist_head *refs, const char *path_refs,
679     const char *subdir, struct got_repository *repo)
680 {
681 	const struct got_error *err = NULL;
682 	DIR *d = NULL;
683 	char *path_subdir;
684 
685 	if (asprintf(&path_subdir, "%s/%s", path_refs, subdir) == -1)
686 		return got_error_from_errno("asprintf");
687 
688 	d = opendir(path_subdir);
689 	if (d == NULL)
690 		goto done;
691 
692 	for (;;) {
693 		struct dirent *dent;
694 		struct got_reference *ref;
695 		char *child;
696 
697 		dent = readdir(d);
698 		if (dent == NULL)
699 			break;
700 
701 		if (strcmp(dent->d_name, ".") == 0 ||
702 		    strcmp(dent->d_name, "..") == 0)
703 			continue;
704 
705 		switch (dent->d_type) {
706 		case DT_REG:
707 			err = open_ref(&ref, path_refs, subdir, dent->d_name,
708 			    0);
709 			if (err)
710 				goto done;
711 			if (ref) {
712 				struct got_reflist_entry *new;
713 				err = insert_ref(&new, refs, ref, repo);
714 				if (err || new == NULL /* duplicate */)
715 					got_ref_close(ref);
716 				if (err)
717 					goto done;
718 			}
719 			break;
720 		case DT_DIR:
721 			if (asprintf(&child, "%s%s%s", subdir,
722 			    subdir[0] == '\0' ? "" : "/", dent->d_name) == -1) {
723 				err = got_error_from_errno("asprintf");
724 				break;
725 			}
726 			err = gather_on_disk_refs(refs, path_refs, child, repo);
727 			free(child);
728 			break;
729 		default:
730 			break;
731 		}
732 	}
733 done:
734 	if (d)
735 		closedir(d);
736 	free(path_subdir);
737 	return err;
738 }
739 
740 const struct got_error *
741 got_ref_list(struct got_reflist_head *refs, struct got_repository *repo)
742 {
743 	const struct got_error *err;
744 	char *packed_refs_path, *path_refs = NULL;
745 	FILE *f = NULL;
746 	struct got_reference *ref;
747 	struct got_reflist_entry *new;
748 
749 	/* HEAD ref should always exist. */
750 	path_refs = get_refs_dir_path(repo, GOT_REF_HEAD);
751 	if (path_refs == NULL) {
752 		err = got_error_from_errno("get_refs_dir_path");
753 		goto done;
754 	}
755 	err = open_ref(&ref, path_refs, "", GOT_REF_HEAD, 0);
756 	if (err)
757 		goto done;
758 	err = insert_ref(&new, refs, ref, repo);
759 	if (err || new == NULL /* duplicate */)
760 		got_ref_close(ref);
761 	if (err)
762 		goto done;
763 
764 	/* Gather on-disk refs before parsing packed-refs. */
765 	free(path_refs);
766 	path_refs = get_refs_dir_path(repo, "");
767 	if (path_refs == NULL) {
768 		err = got_error_from_errno("get_refs_dir_path");
769 		goto done;
770 	}
771 	err = gather_on_disk_refs(refs, path_refs, "", repo);
772 	if (err)
773 		goto done;
774 
775 	/*
776 	 * The packed-refs file may contain redundant entries, in which
777 	 * case on-disk refs take precedence.
778 	 */
779 	packed_refs_path = got_repo_get_path_packed_refs(repo);
780 	if (packed_refs_path == NULL) {
781 		err = got_error_from_errno("got_repo_get_path_packed_refs");
782 		goto done;
783 	}
784 
785 	f = fopen(packed_refs_path, "r");
786 	free(packed_refs_path);
787 	if (f) {
788 		char *line;
789 		size_t len;
790 		const char delim[3] = {'\0', '\0', '\0'};
791 		for (;;) {
792 			line = fparseln(f, &len, NULL, delim, 0);
793 			if (line == NULL) {
794 				if (feof(f))
795 					break;
796 				err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
797 				goto done;
798 			}
799 			err = parse_packed_ref_line(&ref, NULL, line);
800 			free(line);
801 			if (err)
802 				goto done;
803 			if (ref) {
804 				err = insert_ref(&new, refs, ref, repo);
805 				if (err || new == NULL /* duplicate */)
806 					got_ref_close(ref);
807 				if (err)
808 					goto done;
809 			}
810 		}
811 	}
812 done:
813 	free(path_refs);
814 	if (f && fclose(f) != 0 && err == NULL)
815 		err = got_error_from_errno("fclose");
816 	return err;
817 }
818 
819 void
820 got_ref_list_free(struct got_reflist_head *refs)
821 {
822 	struct got_reflist_entry *re;
823 
824 	while (!SIMPLEQ_EMPTY(refs)) {
825 		re = SIMPLEQ_FIRST(refs);
826 		SIMPLEQ_REMOVE_HEAD(refs, entry);
827 		got_ref_close(re->ref);
828 		free(re->id);
829 		free(re);
830 	}
831 
832 }
833 
834 int
835 got_ref_is_symbolic(struct got_reference *ref)
836 {
837 	return (ref->flags & GOT_REF_IS_SYMBOLIC);
838 }
839 
840 const struct got_error *
841 got_ref_change_ref(struct got_reference *ref, struct got_object_id *id)
842 {
843 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
844 		return got_error(GOT_ERR_BAD_REF_TYPE);
845 
846 	memcpy(ref->ref.ref.sha1, id->sha1, sizeof(ref->ref.ref.sha1));
847 	return NULL;
848 }
849 
850 const struct got_error *
851 got_ref_change_symref(struct got_reference *ref, char *refname)
852 {
853 	char *new_name;
854 
855 	if ((ref->flags & GOT_REF_IS_SYMBOLIC) == 0)
856 		return got_error(GOT_ERR_BAD_REF_TYPE);
857 
858 	new_name = strdup(refname);
859 	if (new_name == NULL)
860 		return got_error_from_errno("strdup");
861 
862 	free(ref->ref.symref.name);
863 	ref->ref.symref.name = new_name;
864 	return NULL;
865 }
866 
867 const struct got_error *
868 got_ref_write(struct got_reference *ref, struct got_repository *repo)
869 {
870 	const struct got_error *err = NULL, *unlock_err = NULL;
871 	const char *name = got_ref_get_name(ref);
872 	char *path_refs = NULL, *path = NULL, *tmppath = NULL;
873 	struct got_lockfile *lf = NULL;
874 	FILE *f = NULL;
875 	size_t n;
876 	struct stat sb;
877 
878 	path_refs = get_refs_dir_path(repo, name);
879 	if (path_refs == NULL) {
880 		err = got_error_from_errno2("get_refs_dir_path", name);
881 		goto done;
882 	}
883 
884 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
885 		err = got_error_from_errno("asprintf");
886 		goto done;
887 	}
888 
889 	err = got_opentemp_named(&tmppath, &f, path);
890 	if (err) {
891 		char *parent;
892 		if (!(err->code == GOT_ERR_ERRNO && errno == ENOENT))
893 			goto done;
894 		err = got_path_dirname(&parent, path);
895 		if (err)
896 			goto done;
897 		err = got_path_mkdir(parent);
898 		free(parent);
899 		if (err)
900 			goto done;
901 		err = got_opentemp_named(&tmppath, &f, path);
902 		if (err)
903 			goto done;
904 	}
905 
906 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
907 		n = fprintf(f, "ref: %s\n", ref->ref.symref.ref);
908 		if (n != strlen(ref->ref.symref.ref) + 6) {
909 			err = got_ferror(f, GOT_ERR_IO);
910 			goto done;
911 		}
912 	} else {
913 		char hex[SHA1_DIGEST_STRING_LENGTH];
914 		if (got_sha1_digest_to_str(ref->ref.ref.sha1, hex,
915 		    sizeof(hex)) == NULL) {
916 			err = got_error(GOT_ERR_BAD_REF_DATA);
917 			goto done;
918 		}
919 		n = fprintf(f, "%s\n", hex);
920 		if (n != sizeof(hex)) {
921 			err = got_ferror(f, GOT_ERR_IO);
922 			goto done;
923 		}
924 	}
925 
926 	if (ref->lf == NULL) {
927 		err = got_lockfile_lock(&lf, path);
928 		if (err)
929 			goto done;
930 	}
931 
932 	/* XXX: check if old content matches our expectations? */
933 
934 	if (stat(path, &sb) != 0) {
935 		if (errno != ENOENT) {
936 			err = got_error_from_errno2("stat", path);
937 			goto done;
938 		}
939 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
940 	}
941 
942 	if (rename(tmppath, path) != 0) {
943 		err = got_error_from_errno3("rename", tmppath, path);
944 		goto done;
945 	}
946 	free(tmppath);
947 	tmppath = NULL;
948 
949 	if (chmod(path, sb.st_mode) != 0) {
950 		err = got_error_from_errno2("chmod", path);
951 		goto done;
952 	}
953 done:
954 	if (ref->lf == NULL && lf)
955 		unlock_err = got_lockfile_unlock(lf);
956 	if (f) {
957 		if (fclose(f) != 0 && err == NULL)
958 			err = got_error_from_errno("fclose");
959 	}
960 	free(path_refs);
961 	free(path);
962 	if (tmppath) {
963 		if (unlink(tmppath) != 0 && err == NULL)
964 			err = got_error_from_errno2("unlink", tmppath);
965 		free(tmppath);
966 	}
967 	return err ? err : unlock_err;
968 }
969 
970 static const struct got_error *
971 delete_packed_ref(struct got_reference *delref, struct got_repository *repo)
972 {
973 	const struct got_error *err = NULL, *unlock_err = NULL;
974 	struct got_lockfile *lf = NULL;
975 	FILE *f = NULL, *tmpf = NULL;
976 	char *packed_refs_path, *tmppath = NULL;
977 	struct got_reflist_head refs;
978 	int found_delref = 0;
979 
980 	/* The packed-refs file does not cotain symbolic references. */
981 	if (delref->flags & GOT_REF_IS_SYMBOLIC)
982 		return got_error(GOT_ERR_BAD_REF_DATA);
983 
984 	SIMPLEQ_INIT(&refs);
985 
986 	packed_refs_path = got_repo_get_path_packed_refs(repo);
987 	if (packed_refs_path == NULL)
988 		return got_error_from_errno("got_repo_get_path_packed_refs");
989 
990 	err = got_opentemp_named(&tmppath, &tmpf, packed_refs_path);
991 	if (err)
992 		goto done;
993 
994 	if (delref->lf == NULL) {
995 		err = got_lockfile_lock(&lf, packed_refs_path);
996 		if (err)
997 			goto done;
998 	}
999 
1000 	f = fopen(packed_refs_path, "r");
1001 	if (f == NULL) {
1002 		err = got_error_from_errno2("fopen", packed_refs_path);
1003 		goto done;
1004 	}
1005 	for (;;) {
1006 		char *line;
1007 		size_t len;
1008 		const char delim[3] = {'\0', '\0', '\0'};
1009 		struct got_reference *ref;
1010 		struct got_reflist_entry *new;
1011 
1012 		line = fparseln(f, &len, NULL, delim, 0);
1013 		if (line == NULL) {
1014 			if (feof(f))
1015 				break;
1016 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
1017 			goto done;
1018 		}
1019 		err = parse_packed_ref_line(&ref, NULL, line);
1020 		free(line);
1021 		if (err)
1022 			goto done;
1023 		if (ref == NULL)
1024 			continue;
1025 
1026 		if (strcmp(ref->ref.ref.name, delref->ref.ref.name) == 0 &&
1027 		    memcmp(ref->ref.ref.sha1, delref->ref.ref.sha1,
1028 		    sizeof(delref->ref.ref.sha1)) == 0) {
1029 			found_delref = 1;
1030 			got_ref_close(ref);
1031 			continue;
1032 		}
1033 
1034 		err = insert_ref(&new, &refs, ref, repo);
1035 		if (err || new == NULL /* duplicate */)
1036 			got_ref_close(ref);
1037 		if (err)
1038 			goto done;
1039 	}
1040 
1041 	if (found_delref) {
1042 		struct got_reflist_entry *re;
1043 		size_t n;
1044 		struct stat sb;
1045 
1046 		n = fprintf(tmpf, "%s\n", GOT_PACKED_REFS_HEADER);
1047 		if (n != sizeof(GOT_PACKED_REFS_HEADER)) {
1048 			err = got_ferror(f, GOT_ERR_IO);
1049 			goto done;
1050 		}
1051 
1052 		SIMPLEQ_FOREACH(re, &refs, entry) {
1053 			uint8_t hex[SHA1_DIGEST_STRING_LENGTH];
1054 
1055 			if (got_sha1_digest_to_str(re->ref->ref.ref.sha1, hex,
1056 			    sizeof(hex)) == NULL) {
1057 				err = got_error(GOT_ERR_BAD_REF_DATA);
1058 				goto done;
1059 			}
1060 			n = fprintf(tmpf, "%s ", hex);
1061 			if (n != sizeof(hex)) {
1062 				err = got_ferror(f, GOT_ERR_IO);
1063 				goto done;
1064 			}
1065 			n = fprintf(tmpf, "%s\n", re->ref->ref.ref.name);
1066 			if (n != strlen(re->ref->ref.ref.name) + 1) {
1067 				err = got_ferror(f, GOT_ERR_IO);
1068 				goto done;
1069 			}
1070 		}
1071 
1072 		if (fflush(tmpf) != 0) {
1073 			err = got_error_from_errno("fflush");
1074 			goto done;
1075 		}
1076 
1077 		if (stat(packed_refs_path, &sb) != 0) {
1078 			if (errno != ENOENT) {
1079 				err = got_error_from_errno2("stat",
1080 				    packed_refs_path);
1081 				goto done;
1082 			}
1083 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
1084 		}
1085 
1086 		if (rename(tmppath, packed_refs_path) != 0) {
1087 			err = got_error_from_errno3("rename", tmppath,
1088 			    packed_refs_path);
1089 			goto done;
1090 		}
1091 
1092 		if (chmod(packed_refs_path, sb.st_mode) != 0) {
1093 			err = got_error_from_errno2("chmod",
1094 			    packed_refs_path);
1095 			goto done;
1096 		}
1097 	}
1098 done:
1099 	if (delref->lf == NULL && lf)
1100 		unlock_err = got_lockfile_unlock(lf);
1101 	if (f) {
1102 		if (fclose(f) != 0 && err == NULL)
1103 			err = got_error_from_errno("fclose");
1104 	}
1105 	if (tmpf) {
1106 		unlink(tmppath);
1107 		if (fclose(tmpf) != 0 && err == NULL)
1108 			err = got_error_from_errno("fclose");
1109 	}
1110 	free(tmppath);
1111 	free(packed_refs_path);
1112 	got_ref_list_free(&refs);
1113 	return err ? err : unlock_err;
1114 }
1115 
1116 const struct got_error *
1117 got_ref_delete(struct got_reference *ref, struct got_repository *repo)
1118 {
1119 	const struct got_error *err = NULL, *unlock_err = NULL;
1120 	const char *name = got_ref_get_name(ref);
1121 	char *path_refs = NULL, *path = NULL;
1122 	struct got_lockfile *lf = NULL;
1123 
1124 	if (ref->flags & GOT_REF_IS_PACKED)
1125 		return delete_packed_ref(ref, repo);
1126 
1127 	path_refs = get_refs_dir_path(repo, name);
1128 	if (path_refs == NULL) {
1129 		err = got_error_from_errno2("get_refs_dir_path", name);
1130 		goto done;
1131 	}
1132 
1133 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1134 		err = got_error_from_errno("asprintf");
1135 		goto done;
1136 	}
1137 
1138 	if (ref->lf == NULL) {
1139 		err = got_lockfile_lock(&lf, path);
1140 		if (err)
1141 			goto done;
1142 	}
1143 
1144 	/* XXX: check if old content matches our expectations? */
1145 
1146 	if (unlink(path) != 0)
1147 		err = got_error_from_errno2("unlink", path);
1148 done:
1149 	if (ref->lf == NULL && lf)
1150 		unlock_err = got_lockfile_unlock(lf);
1151 
1152 	free(path_refs);
1153 	free(path);
1154 	return err ? err : unlock_err;
1155 }
1156 
1157 const struct got_error *
1158 got_ref_unlock(struct got_reference *ref)
1159 {
1160 	const struct got_error *err;
1161 	err = got_lockfile_unlock(ref->lf);
1162 	ref->lf = NULL;
1163 	return err;
1164 }