op public repos

Blob

Date:: Thu Nov 28 02:32:58 2019 UTC
Message:: convert tree entries from SIMPLEQ to an array
Actions:: History | Blame | Raw File
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 <util.h>
30 #include <zlib.h>
31 #include <time.h>
32 #include <libgen.h>
33 
34 #include "got_error.h"
35 #include "got_object.h"
36 #include "got_repository.h"
37 #include "got_reference.h"
38 #include "got_opentemp.h"
39 #include "got_path.h"
40 
41 #include "got_lib_sha1.h"
42 #include "got_lib_delta.h"
43 #include "got_lib_inflate.h"
44 #include "got_lib_object.h"
45 #include "got_lib_lockfile.h"
46 
47 #ifndef nitems
48 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
49 #endif
50 
51 #define GOT_REF_HEADS	"heads"
52 #define GOT_REF_TAGS	"tags"
53 #define GOT_REF_REMOTES	"remotes"
54 
55 /*
56  * We do not resolve tags yet, and don't yet care about sorting refs either,
57  * so packed-refs files we write contain a minimal header which disables all
58  * packed-refs "traits" supported by Git.
59  */
60 #define GOT_PACKED_REFS_HEADER	"# pack-refs with:"
61 
62 /* A symbolic reference. */
63 struct got_symref {
64 	char *name;
65 	char *ref;
66 };
67 
68 #define GOT_REF_RECURSE_MAX	20
69 
70 /* A non-symbolic reference (there is no better designation). */
71 struct got_ref {
72 	char *name;
73 	u_int8_t sha1[SHA1_DIGEST_LENGTH];
74 };
75 
76 /* A reference which points to an arbitrary object. */
77 struct got_reference {
78 	unsigned int flags;
79 #define GOT_REF_IS_SYMBOLIC	0x01
80 #define GOT_REF_IS_PACKED	0x02
81 
82 	union {
83 		struct got_ref ref;
84 		struct got_symref symref;
85 	} ref;
86 
87 	struct got_lockfile *lf;
88 };
89 
90 static const struct got_error *
91 alloc_ref(struct got_reference **ref, const char *name,
92     struct got_object_id *id, int flags)
93 {
94 	const struct got_error *err = NULL;
95 
96 	*ref = calloc(1, sizeof(**ref));
97 	if (*ref == NULL)
98 		return got_error_from_errno("calloc");
99 
100 	memcpy((*ref)->ref.ref.sha1, id->sha1, sizeof((*ref)->ref.ref.sha1));
101 	(*ref)->flags = flags;
102 	(*ref)->ref.ref.name = strdup(name);
103 	if ((*ref)->ref.ref.name == NULL) {
104 		err = got_error_from_errno("strdup");
105 		got_ref_close(*ref);
106 		*ref = NULL;
107 	}
108 	return err;
109 }
110 
111 static const struct got_error *
112 alloc_symref(struct got_reference **ref, const char *name,
113     const char *target_ref, int flags)
114 {
115 	const struct got_error *err = NULL;
116 
117 	*ref = calloc(1, sizeof(**ref));
118 	if (*ref == NULL)
119 		return got_error_from_errno("calloc");
120 
121 	(*ref)->flags = GOT_REF_IS_SYMBOLIC | flags;
122 	(*ref)->ref.symref.name = strdup(name);
123 	if ((*ref)->ref.symref.name == NULL) {
124 		err = got_error_from_errno("strdup");
125 		got_ref_close(*ref);
126 		*ref = NULL;
127 		return err;
128 	}
129 	(*ref)->ref.symref.ref = strdup(target_ref);
130 	if ((*ref)->ref.symref.ref == NULL) {
131 		err = got_error_from_errno("strdup");
132 		got_ref_close(*ref);
133 		*ref = NULL;
134 	}
135 	return err;
136 }
137 
138 static const struct got_error *
139 parse_symref(struct got_reference **ref, const char *name, const char *line)
140 {
141 	if (line[0] == '\0')
142 		return got_error(GOT_ERR_BAD_REF_DATA);
143 
144 	return alloc_symref(ref, name, line, 0);
145 }
146 
147 static const struct got_error *
148 parse_ref_line(struct got_reference **ref, const char *name, const char *line)
149 {
150 	struct got_object_id id;
151 
152 	if (strncmp(line, "ref: ", 5) == 0) {
153 		line += 5;
154 		return parse_symref(ref, name, line);
155 	}
156 
157 	if (!got_parse_sha1_digest(id.sha1, line))
158 		return got_error(GOT_ERR_BAD_REF_DATA);
159 
160 	return alloc_ref(ref, name, &id, 0);
161 }
162 
163 static const struct got_error *
164 parse_ref_file(struct got_reference **ref, const char *name,
165     const char *abspath, int lock)
166 {
167 	const struct got_error *err = NULL;
168 	FILE *f;
169 	char *line = NULL;
170 	size_t linesize = 0;
171 	ssize_t linelen;
172 	struct got_lockfile *lf = NULL;
173 
174 	if (lock) {
175 		err = got_lockfile_lock(&lf, abspath);
176 		if (err)
177 			return (err);
178 	}
179 
180 	f = fopen(abspath, "rb");
181 	if (f == NULL) {
182 		if (lock)
183 			got_lockfile_unlock(lf);
184 		return NULL;
185 	}
186 
187 	linelen = getline(&line, &linesize, f);
188 	if (linelen == -1) {
189 		if (feof(f))
190 			err = NULL; /* ignore empty files (could be locks) */
191 		else
192 			err = got_error_from_errno2("getline", abspath);
193 		if (lock)
194 			got_lockfile_unlock(lf);
195 		goto done;
196 	}
197 	while (linelen > 0 && line[linelen - 1] == '\n') {
198 		line[linelen - 1] = '\0';
199 		linelen--;
200 	}
201 
202 	err = parse_ref_line(ref, name, line);
203 	if (lock) {
204 		if (err)
205 			got_lockfile_unlock(lf);
206 		else {
207 			if (*ref)
208 				(*ref)->lf = lf;
209 			else
210 				got_lockfile_unlock(lf);
211 		}
212 	}
213 done:
214 	free(line);
215 	if (fclose(f) != 0 && err == NULL) {
216 		err = got_error_from_errno("fclose");
217 		if (*ref) {
218 			if (lock)
219 				got_ref_unlock(*ref);
220 			got_ref_close(*ref);
221 			*ref = NULL;
222 		}
223 	}
224 	return err;
225 }
226 
227 static int
228 is_well_known_ref(const char *refname)
229 {
230 	return (strcmp(refname, GOT_REF_HEAD) == 0 ||
231 	    strcmp(refname, GOT_REF_ORIG_HEAD) == 0 ||
232 	    strcmp(refname, GOT_REF_MERGE_HEAD) == 0 ||
233 	    strcmp(refname, GOT_REF_FETCH_HEAD) == 0);
234 }
235 
236 static char *
237 get_refs_dir_path(struct got_repository *repo, const char *refname)
238 {
239 	if (is_well_known_ref(refname) || strncmp(refname, "refs/", 5) == 0)
240 		return strdup(got_repo_get_path_git_dir(repo));
241 
242 	return got_repo_get_path_refs(repo);
243 }
244 
245 static int
246 is_valid_ref_name(const char *name)
247 {
248 	const char *s, *slash, *seg;
249 	const char forbidden[] = { ' ', '~', '^', ':', '?', '*', '[' , '\\' };
250 	const char *forbidden_seq[] = { "//", "..", "@{" };
251 	const char *lfs = GOT_LOCKFILE_SUFFIX;
252 	const size_t lfs_len = sizeof(GOT_LOCKFILE_SUFFIX) - 1;
253 	int i;
254 
255 	if (name[0] == '@' && name[1] == '\0')
256 		return 0;
257 
258 	slash = strchr(name, '/');
259 	if (slash == NULL)
260 		return 0;
261 
262 	s = name;
263 	seg = s;
264 	if (seg[0] == '\0' || seg[0] == '.' || seg[0] == '/')
265 		return 0;
266 	while (*s) {
267 		for (i = 0; i < nitems(forbidden); i++) {
268 			if (*s == forbidden[i])
269 				return 0;
270 		}
271 		for (i = 0; i < nitems(forbidden_seq); i++) {
272 			if (s[0] == forbidden_seq[i][0] &&
273 			    s[1] == forbidden_seq[i][1])
274 				return 0;
275 		}
276 		if (iscntrl((unsigned char)s[0]))
277 			return 0;
278 		if (s[0] == '.' && s[1] == '\0')
279 			return 0;
280 		if (*s == '/') {
281 			const char *nextseg = s + 1;
282 			if (nextseg[0] == '\0' || nextseg[0] == '.' ||
283 			    nextseg[0] == '/')
284 				return 0;
285 			if (seg <= s - lfs_len &&
286 			    strncmp(s - lfs_len, lfs, lfs_len) == 0)
287 				return 0;
288 			seg = nextseg;
289 		}
290 		s++;
291 	}
292 
293 	if (seg <= s - lfs_len &&
294 	    strncmp(s - lfs_len, lfs, lfs_len) == 0)
295 		return 0;
296 
297 	return 1;
298 }
299 
300 const struct got_error *
301 got_ref_alloc(struct got_reference **ref, const char *name,
302     struct got_object_id *id)
303 {
304 	if (!is_valid_ref_name(name))
305 		return got_error_path(name, GOT_ERR_BAD_REF_NAME);
306 
307 	return alloc_ref(ref, name, id, 0);
308 }
309 
310 const struct got_error *
311 got_ref_alloc_symref(struct got_reference **ref, const char *name,
312 	struct got_reference *target_ref)
313 {
314 	if (!is_valid_ref_name(name))
315 		return got_error_path(name, GOT_ERR_BAD_REF_NAME);
316 
317 	return alloc_symref(ref, name, got_ref_get_name(target_ref), 0);
318 }
319 
320 static const struct got_error *
321 parse_packed_ref_line(struct got_reference **ref, const char *abs_refname,
322     const char *line)
323 {
324 	struct got_object_id id;
325 	const char *name;
326 
327 	*ref = NULL;
328 
329 	if (line[0] == '#' || line[0] == '^')
330 		return NULL;
331 
332 	if (!got_parse_sha1_digest(id.sha1, line))
333 		return got_error(GOT_ERR_BAD_REF_DATA);
334 
335 	if (abs_refname) {
336 		if (strcmp(line + SHA1_DIGEST_STRING_LENGTH, abs_refname) != 0)
337 			return NULL;
338 		name = abs_refname;
339 	} else
340 		name = line + SHA1_DIGEST_STRING_LENGTH;
341 
342 	return alloc_ref(ref, name, &id, GOT_REF_IS_PACKED);
343 }
344 
345 static const struct got_error *
346 open_packed_ref(struct got_reference **ref, FILE *f, const char **subdirs,
347     int nsubdirs, const char *refname)
348 {
349 	const struct got_error *err = NULL;
350 	char *abs_refname;
351 	char *line;
352 	size_t len;
353 	const char delim[3] = {'\0', '\0', '\0'};
354 	int i, ref_is_absolute = (strncmp(refname, "refs/", 5) == 0);
355 
356 	*ref = NULL;
357 
358 	if (ref_is_absolute)
359 		abs_refname = (char *)refname;
360 	do {
361 		line = fparseln(f, &len, NULL, delim, 0);
362 		if (line == NULL) {
363 			if (feof(f))
364 				break;
365 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
366 			break;
367 		}
368 		for (i = 0; i < nsubdirs; i++) {
369 			if (!ref_is_absolute &&
370 			    asprintf(&abs_refname, "refs/%s/%s", subdirs[i],
371 			    refname) == -1)
372 				return got_error_from_errno("asprintf");
373 			err = parse_packed_ref_line(ref, abs_refname, line);
374 			if (!ref_is_absolute)
375 				free(abs_refname);
376 			if (err || *ref != NULL)
377 				break;
378 		}
379 		free(line);
380 		if (err)
381 			break;
382 	} while (*ref == NULL);
383 
384 	return err;
385 }
386 
387 static const struct got_error *
388 open_ref(struct got_reference **ref, const char *path_refs, const char *subdir,
389     const char *name, int lock)
390 {
391 	const struct got_error *err = NULL;
392 	char *path = NULL;
393 	char *absname = NULL;
394 	int ref_is_absolute = (strncmp(name, "refs/", 5) == 0);
395 	int ref_is_well_known = is_well_known_ref(name);
396 
397 	*ref = NULL;
398 
399 	if (ref_is_absolute || ref_is_well_known) {
400 		if (asprintf(&path, "%s/%s", path_refs, name) == -1)
401 			return got_error_from_errno("asprintf");
402 		absname = (char *)name;
403 	} else {
404 		if (asprintf(&path, "%s/%s%s%s", path_refs, subdir,
405 		    subdir[0] ? "/" : "", name) == -1)
406 			return got_error_from_errno("asprintf");
407 
408 		if (asprintf(&absname, "refs/%s%s%s",
409 		    subdir, subdir[0] ? "/" : "", name) == -1) {
410 			err = got_error_from_errno("asprintf");
411 			goto done;
412 		}
413 	}
414 
415 	err = parse_ref_file(ref, absname, path, lock);
416 done:
417 	if (!ref_is_absolute && !ref_is_well_known)
418 		free(absname);
419 	free(path);
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 const struct got_error *
540 got_reflist_entry_dup(struct got_reflist_entry **newp,
541     struct got_reflist_entry *re)
542 {
543 	const struct got_error *err = NULL;
544 	struct got_reflist_entry *new;
545 
546 	*newp = NULL;
547 
548 	new = malloc(sizeof(*new));
549 	if (new == NULL)
550 		return got_error_from_errno("malloc");
551 
552 	new->ref = got_ref_dup(re->ref);
553 	if (new->ref == NULL) {
554 		err = got_error_from_errno("got_ref_dup");
555 		free(new);
556 		return err;
557 	}
558 
559 	new->id = got_object_id_dup(re->id);
560 	if (new->id == NULL) {
561 		err = got_error_from_errno("got_ref_dup");
562 		free(new->id);
563 		free(new);
564 		return err;
565 	}
566 
567 	*newp = new;
568 	return NULL;
569 }
570 
571 static const struct got_error *
572 resolve_symbolic_ref(struct got_reference **resolved,
573     struct got_repository *repo, struct got_reference *ref)
574 {
575 	struct got_reference *nextref;
576 	const struct got_error *err;
577 
578 	err = got_ref_open(&nextref, repo, ref->ref.symref.ref, 0);
579 	if (err)
580 		return err;
581 
582 	if (nextref->flags & GOT_REF_IS_SYMBOLIC)
583 		err = resolve_symbolic_ref(resolved, repo, nextref);
584 	else
585 		*resolved = got_ref_dup(nextref);
586 
587 	got_ref_close(nextref);
588 	return err;
589 }
590 
591 static const struct got_error *
592 ref_resolve(struct got_object_id **id, struct got_repository *repo,
593     struct got_reference *ref, int recursion)
594 {
595 	const struct got_error *err;
596 
597 	if (recursion <= 0)
598 		return got_error_msg(GOT_ERR_RECURSION,
599 		    "reference recursion limit reached");
600 
601 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
602 		struct got_reference *resolved = NULL;
603 		err = resolve_symbolic_ref(&resolved, repo, ref);
604 		if (err == NULL)
605 			err = ref_resolve(id, repo, resolved, --recursion);
606 		if (resolved)
607 			got_ref_close(resolved);
608 		return err;
609 	}
610 
611 	*id = calloc(1, sizeof(**id));
612 	if (*id == NULL)
613 		return got_error_from_errno("calloc");
614 	memcpy((*id)->sha1, ref->ref.ref.sha1, sizeof((*id)->sha1));
615 	return NULL;
616 }
617 
618 const struct got_error *
619 got_ref_resolve(struct got_object_id **id, struct got_repository *repo,
620     struct got_reference *ref)
621 {
622 	return ref_resolve(id, repo, ref, GOT_REF_RECURSE_MAX);
623 }
624 
625 char *
626 got_ref_to_str(struct got_reference *ref)
627 {
628 	char *str;
629 
630 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
631 		return strdup(ref->ref.symref.ref);
632 
633 	str = malloc(SHA1_DIGEST_STRING_LENGTH);
634 	if (str == NULL)
635 		return NULL;
636 
637 	if (got_sha1_digest_to_str(ref->ref.ref.sha1, str,
638 	    SHA1_DIGEST_STRING_LENGTH) == NULL) {
639 		free(str);
640 		return NULL;
641 	}
642 
643 	return str;
644 }
645 
646 const char *
647 got_ref_get_name(struct got_reference *ref)
648 {
649 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
650 		return ref->ref.symref.name;
651 
652 	return ref->ref.ref.name;
653 }
654 
655 const char *
656 got_ref_get_symref_target(struct got_reference *ref)
657 {
658 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
659 		return ref->ref.symref.ref;
660 
661 	return NULL;
662 }
663 
664 const struct got_error *
665 got_ref_cmp_by_name(void *arg, int *cmp, struct got_reference *re1,
666     struct got_reference* re2)
667 {
668 	const char *name1 = got_ref_get_name(re1);
669 	const char *name2 = got_ref_get_name(re2);
670 
671 	*cmp = got_path_cmp(name1, name2, strlen(name1), strlen(name2));
672 	return NULL;
673 }
674 
675 static const struct got_error *
676 insert_ref(struct got_reflist_entry **newp, struct got_reflist_head *refs,
677     struct got_reference *ref, struct got_repository *repo,
678     got_ref_cmp_cb cmp_cb, void *cmp_arg)
679 {
680 	const struct got_error *err;
681 	struct got_object_id *id;
682 	struct got_reflist_entry *new, *re, *prev = NULL;
683 	int cmp;
684 
685 	*newp = NULL;
686 
687 	err = got_ref_resolve(&id, repo, ref);
688 	if (err)
689 		return err;
690 
691 	new = malloc(sizeof(*new));
692 	if (new == NULL) {
693 		free(id);
694 		return got_error_from_errno("malloc");
695 	}
696 	new->ref = ref;
697 	new->id = id;
698 	*newp = new;
699 
700 	/*
701 	 * We must de-duplicate entries on insert because packed-refs may
702 	 * contain redundant entries. On-disk refs take precedence.
703 	 * This code assumes that on-disk revs are read before packed-refs.
704 	 * We're iterating the list anyway, so insert elements sorted by name.
705 	 */
706 	re = SIMPLEQ_FIRST(refs);
707 	while (re) {
708 		err = (*cmp_cb)(cmp_arg, &cmp, re->ref, new->ref);
709 		if (err)
710 			return err;
711 		if (cmp == 0) {
712 			/* duplicate */
713 			free(new->id);
714 			free(new);
715 			*newp = NULL;
716 			return NULL;
717 		} else if (cmp > 0) {
718 			if (prev)
719 				SIMPLEQ_INSERT_AFTER(refs, prev, new, entry);
720 			else
721 				SIMPLEQ_INSERT_HEAD(refs, new, entry);
722 			return NULL;
723 		} else {
724 			prev = re;
725 			re = SIMPLEQ_NEXT(re, entry);
726 		}
727 	}
728 
729 	SIMPLEQ_INSERT_TAIL(refs, new, entry);
730 	return NULL;
731 }
732 
733 static const struct got_error *
734 gather_on_disk_refs(struct got_reflist_head *refs, const char *path_refs,
735     const char *subdir, struct got_repository *repo,
736     got_ref_cmp_cb cmp_cb, void *cmp_arg)
737 {
738 	const struct got_error *err = NULL;
739 	DIR *d = NULL;
740 	char *path_subdir;
741 
742 	if (asprintf(&path_subdir, "%s/%s", path_refs, subdir) == -1)
743 		return got_error_from_errno("asprintf");
744 
745 	d = opendir(path_subdir);
746 	if (d == NULL)
747 		goto done;
748 
749 	for (;;) {
750 		struct dirent *dent;
751 		struct got_reference *ref;
752 		char *child;
753 
754 		dent = readdir(d);
755 		if (dent == NULL)
756 			break;
757 
758 		if (strcmp(dent->d_name, ".") == 0 ||
759 		    strcmp(dent->d_name, "..") == 0)
760 			continue;
761 
762 		switch (dent->d_type) {
763 		case DT_REG:
764 			err = open_ref(&ref, path_refs, subdir, dent->d_name,
765 			    0);
766 			if (err)
767 				goto done;
768 			if (ref) {
769 				struct got_reflist_entry *new;
770 				err = insert_ref(&new, refs, ref, repo,
771 				    cmp_cb, cmp_arg);
772 				if (err || new == NULL /* duplicate */)
773 					got_ref_close(ref);
774 				if (err)
775 					goto done;
776 			}
777 			break;
778 		case DT_DIR:
779 			if (asprintf(&child, "%s%s%s", subdir,
780 			    subdir[0] == '\0' ? "" : "/", dent->d_name) == -1) {
781 				err = got_error_from_errno("asprintf");
782 				break;
783 			}
784 			err = gather_on_disk_refs(refs, path_refs, child, repo,
785 			    cmp_cb, cmp_arg);
786 			free(child);
787 			break;
788 		default:
789 			break;
790 		}
791 	}
792 done:
793 	if (d)
794 		closedir(d);
795 	free(path_subdir);
796 	return err;
797 }
798 
799 const struct got_error *
800 got_ref_list(struct got_reflist_head *refs, struct got_repository *repo,
801     const char *ref_namespace, got_ref_cmp_cb cmp_cb, void *cmp_arg)
802 {
803 	const struct got_error *err;
804 	char *packed_refs_path, *path_refs = NULL;
805 	const char *ondisk_ref_namespace = NULL;
806 	FILE *f = NULL;
807 	struct got_reference *ref;
808 	struct got_reflist_entry *new;
809 
810 	if (ref_namespace == NULL || ref_namespace[0] == '\0') {
811 		/* HEAD ref should always exist. */
812 		path_refs = get_refs_dir_path(repo, GOT_REF_HEAD);
813 		if (path_refs == NULL) {
814 			err = got_error_from_errno("get_refs_dir_path");
815 			goto done;
816 		}
817 		err = open_ref(&ref, path_refs, "", GOT_REF_HEAD, 0);
818 		if (err)
819 			goto done;
820 		err = insert_ref(&new, refs, ref, repo, cmp_cb, cmp_arg);
821 		if (err || new == NULL /* duplicate */)
822 			got_ref_close(ref);
823 		if (err)
824 			goto done;
825 	}
826 
827 	ondisk_ref_namespace = ref_namespace;
828 	if (ref_namespace && strncmp(ref_namespace, "refs/", 5) == 0)
829 		ondisk_ref_namespace += 5;
830 
831 	/* Gather on-disk refs before parsing packed-refs. */
832 	free(path_refs);
833 	path_refs = get_refs_dir_path(repo, "");
834 	if (path_refs == NULL) {
835 		err = got_error_from_errno("get_refs_dir_path");
836 		goto done;
837 	}
838 	err = gather_on_disk_refs(refs, path_refs,
839 	    ondisk_ref_namespace ? ondisk_ref_namespace : "", repo,
840 	    cmp_cb, cmp_arg);
841 	if (err)
842 		goto done;
843 
844 	/*
845 	 * The packed-refs file may contain redundant entries, in which
846 	 * case on-disk refs take precedence.
847 	 */
848 	packed_refs_path = got_repo_get_path_packed_refs(repo);
849 	if (packed_refs_path == NULL) {
850 		err = got_error_from_errno("got_repo_get_path_packed_refs");
851 		goto done;
852 	}
853 
854 	f = fopen(packed_refs_path, "r");
855 	free(packed_refs_path);
856 	if (f) {
857 		char *line;
858 		size_t len;
859 		const char delim[3] = {'\0', '\0', '\0'};
860 		for (;;) {
861 			line = fparseln(f, &len, NULL, delim, 0);
862 			if (line == NULL) {
863 				if (feof(f))
864 					break;
865 				err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
866 				goto done;
867 			}
868 			err = parse_packed_ref_line(&ref, NULL, line);
869 			free(line);
870 			if (err)
871 				goto done;
872 			if (ref) {
873 				if (ref_namespace) {
874 					const char *name;
875 					name = got_ref_get_name(ref);
876 					if (strncmp(name, ref_namespace,
877 					    strlen(ref_namespace)) != 0) {
878 						got_ref_close(ref);
879 						continue;
880 					}
881 				}
882 				err = insert_ref(&new, refs, ref, repo,
883 				    cmp_cb, cmp_arg);
884 				if (err || new == NULL /* duplicate */)
885 					got_ref_close(ref);
886 				if (err)
887 					goto done;
888 			}
889 		}
890 	}
891 done:
892 	free(path_refs);
893 	if (f && fclose(f) != 0 && err == NULL)
894 		err = got_error_from_errno("fclose");
895 	return err;
896 }
897 
898 void
899 got_ref_list_free(struct got_reflist_head *refs)
900 {
901 	struct got_reflist_entry *re;
902 
903 	while (!SIMPLEQ_EMPTY(refs)) {
904 		re = SIMPLEQ_FIRST(refs);
905 		SIMPLEQ_REMOVE_HEAD(refs, entry);
906 		got_ref_close(re->ref);
907 		free(re->id);
908 		free(re);
909 	}
910 
911 }
912 
913 int
914 got_ref_is_symbolic(struct got_reference *ref)
915 {
916 	return (ref->flags & GOT_REF_IS_SYMBOLIC);
917 }
918 
919 const struct got_error *
920 got_ref_change_ref(struct got_reference *ref, struct got_object_id *id)
921 {
922 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
923 		return got_error(GOT_ERR_BAD_REF_TYPE);
924 
925 	memcpy(ref->ref.ref.sha1, id->sha1, sizeof(ref->ref.ref.sha1));
926 	return NULL;
927 }
928 
929 const struct got_error *
930 got_ref_change_symref(struct got_reference *ref, char *refname)
931 {
932 	char *new_name;
933 
934 	if ((ref->flags & GOT_REF_IS_SYMBOLIC) == 0)
935 		return got_error(GOT_ERR_BAD_REF_TYPE);
936 
937 	new_name = strdup(refname);
938 	if (new_name == NULL)
939 		return got_error_from_errno("strdup");
940 
941 	free(ref->ref.symref.name);
942 	ref->ref.symref.name = new_name;
943 	return NULL;
944 }
945 
946 const struct got_error *
947 got_ref_write(struct got_reference *ref, struct got_repository *repo)
948 {
949 	const struct got_error *err = NULL, *unlock_err = NULL;
950 	const char *name = got_ref_get_name(ref);
951 	char *path_refs = NULL, *path = NULL, *tmppath = NULL;
952 	struct got_lockfile *lf = NULL;
953 	FILE *f = NULL;
954 	size_t n;
955 	struct stat sb;
956 
957 	path_refs = get_refs_dir_path(repo, name);
958 	if (path_refs == NULL) {
959 		err = got_error_from_errno2("get_refs_dir_path", name);
960 		goto done;
961 	}
962 
963 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
964 		err = got_error_from_errno("asprintf");
965 		goto done;
966 	}
967 
968 	err = got_opentemp_named(&tmppath, &f, path);
969 	if (err) {
970 		char *parent;
971 		if (!(err->code == GOT_ERR_ERRNO && errno == ENOENT))
972 			goto done;
973 		err = got_path_dirname(&parent, path);
974 		if (err)
975 			goto done;
976 		err = got_path_mkdir(parent);
977 		free(parent);
978 		if (err)
979 			goto done;
980 		err = got_opentemp_named(&tmppath, &f, path);
981 		if (err)
982 			goto done;
983 	}
984 
985 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
986 		n = fprintf(f, "ref: %s\n", ref->ref.symref.ref);
987 		if (n != strlen(ref->ref.symref.ref) + 6) {
988 			err = got_ferror(f, GOT_ERR_IO);
989 			goto done;
990 		}
991 	} else {
992 		char hex[SHA1_DIGEST_STRING_LENGTH];
993 		if (got_sha1_digest_to_str(ref->ref.ref.sha1, hex,
994 		    sizeof(hex)) == NULL) {
995 			err = got_error(GOT_ERR_BAD_REF_DATA);
996 			goto done;
997 		}
998 		n = fprintf(f, "%s\n", hex);
999 		if (n != sizeof(hex)) {
1000 			err = got_ferror(f, GOT_ERR_IO);
1001 			goto done;
1002 		}
1003 	}
1004 
1005 	if (ref->lf == NULL) {
1006 		err = got_lockfile_lock(&lf, path);
1007 		if (err)
1008 			goto done;
1009 	}
1010 
1011 	/* XXX: check if old content matches our expectations? */
1012 
1013 	if (stat(path, &sb) != 0) {
1014 		if (errno != ENOENT) {
1015 			err = got_error_from_errno2("stat", path);
1016 			goto done;
1017 		}
1018 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
1019 	}
1020 
1021 	if (rename(tmppath, path) != 0) {
1022 		err = got_error_from_errno3("rename", tmppath, path);
1023 		goto done;
1024 	}
1025 	free(tmppath);
1026 	tmppath = NULL;
1027 
1028 	if (chmod(path, sb.st_mode) != 0) {
1029 		err = got_error_from_errno2("chmod", path);
1030 		goto done;
1031 	}
1032 done:
1033 	if (ref->lf == NULL && lf)
1034 		unlock_err = got_lockfile_unlock(lf);
1035 	if (f) {
1036 		if (fclose(f) != 0 && err == NULL)
1037 			err = got_error_from_errno("fclose");
1038 	}
1039 	free(path_refs);
1040 	free(path);
1041 	if (tmppath) {
1042 		if (unlink(tmppath) != 0 && err == NULL)
1043 			err = got_error_from_errno2("unlink", tmppath);
1044 		free(tmppath);
1045 	}
1046 	return err ? err : unlock_err;
1047 }
1048 
1049 static const struct got_error *
1050 delete_packed_ref(struct got_reference *delref, struct got_repository *repo)
1051 {
1052 	const struct got_error *err = NULL, *unlock_err = NULL;
1053 	struct got_lockfile *lf = NULL;
1054 	FILE *f = NULL, *tmpf = NULL;
1055 	char *packed_refs_path, *tmppath = NULL;
1056 	struct got_reflist_head refs;
1057 	int found_delref = 0;
1058 
1059 	/* The packed-refs file does not cotain symbolic references. */
1060 	if (delref->flags & GOT_REF_IS_SYMBOLIC)
1061 		return got_error(GOT_ERR_BAD_REF_DATA);
1062 
1063 	SIMPLEQ_INIT(&refs);
1064 
1065 	packed_refs_path = got_repo_get_path_packed_refs(repo);
1066 	if (packed_refs_path == NULL)
1067 		return got_error_from_errno("got_repo_get_path_packed_refs");
1068 
1069 	err = got_opentemp_named(&tmppath, &tmpf, packed_refs_path);
1070 	if (err)
1071 		goto done;
1072 
1073 	if (delref->lf == NULL) {
1074 		err = got_lockfile_lock(&lf, packed_refs_path);
1075 		if (err)
1076 			goto done;
1077 	}
1078 
1079 	f = fopen(packed_refs_path, "r");
1080 	if (f == NULL) {
1081 		err = got_error_from_errno2("fopen", packed_refs_path);
1082 		goto done;
1083 	}
1084 	for (;;) {
1085 		char *line;
1086 		size_t len;
1087 		const char delim[3] = {'\0', '\0', '\0'};
1088 		struct got_reference *ref;
1089 		struct got_reflist_entry *new;
1090 
1091 		line = fparseln(f, &len, NULL, delim, 0);
1092 		if (line == NULL) {
1093 			if (feof(f))
1094 				break;
1095 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
1096 			goto done;
1097 		}
1098 		err = parse_packed_ref_line(&ref, NULL, line);
1099 		free(line);
1100 		if (err)
1101 			goto done;
1102 		if (ref == NULL)
1103 			continue;
1104 
1105 		if (strcmp(ref->ref.ref.name, delref->ref.ref.name) == 0 &&
1106 		    memcmp(ref->ref.ref.sha1, delref->ref.ref.sha1,
1107 		    sizeof(delref->ref.ref.sha1)) == 0) {
1108 			found_delref = 1;
1109 			got_ref_close(ref);
1110 			continue;
1111 		}
1112 
1113 		err = insert_ref(&new, &refs, ref, repo,
1114 		    got_ref_cmp_by_name, NULL);
1115 		if (err || new == NULL /* duplicate */)
1116 			got_ref_close(ref);
1117 		if (err)
1118 			goto done;
1119 	}
1120 
1121 	if (found_delref) {
1122 		struct got_reflist_entry *re;
1123 		size_t n;
1124 		struct stat sb;
1125 
1126 		n = fprintf(tmpf, "%s\n", GOT_PACKED_REFS_HEADER);
1127 		if (n != sizeof(GOT_PACKED_REFS_HEADER)) {
1128 			err = got_ferror(f, GOT_ERR_IO);
1129 			goto done;
1130 		}
1131 
1132 		SIMPLEQ_FOREACH(re, &refs, entry) {
1133 			uint8_t hex[SHA1_DIGEST_STRING_LENGTH];
1134 
1135 			if (got_sha1_digest_to_str(re->ref->ref.ref.sha1, hex,
1136 			    sizeof(hex)) == NULL) {
1137 				err = got_error(GOT_ERR_BAD_REF_DATA);
1138 				goto done;
1139 			}
1140 			n = fprintf(tmpf, "%s ", hex);
1141 			if (n != sizeof(hex)) {
1142 				err = got_ferror(f, GOT_ERR_IO);
1143 				goto done;
1144 			}
1145 			n = fprintf(tmpf, "%s\n", re->ref->ref.ref.name);
1146 			if (n != strlen(re->ref->ref.ref.name) + 1) {
1147 				err = got_ferror(f, GOT_ERR_IO);
1148 				goto done;
1149 			}
1150 		}
1151 
1152 		if (fflush(tmpf) != 0) {
1153 			err = got_error_from_errno("fflush");
1154 			goto done;
1155 		}
1156 
1157 		if (stat(packed_refs_path, &sb) != 0) {
1158 			if (errno != ENOENT) {
1159 				err = got_error_from_errno2("stat",
1160 				    packed_refs_path);
1161 				goto done;
1162 			}
1163 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
1164 		}
1165 
1166 		if (rename(tmppath, packed_refs_path) != 0) {
1167 			err = got_error_from_errno3("rename", tmppath,
1168 			    packed_refs_path);
1169 			goto done;
1170 		}
1171 
1172 		if (chmod(packed_refs_path, sb.st_mode) != 0) {
1173 			err = got_error_from_errno2("chmod",
1174 			    packed_refs_path);
1175 			goto done;
1176 		}
1177 	}
1178 done:
1179 	if (delref->lf == NULL && lf)
1180 		unlock_err = got_lockfile_unlock(lf);
1181 	if (f) {
1182 		if (fclose(f) != 0 && err == NULL)
1183 			err = got_error_from_errno("fclose");
1184 	}
1185 	if (tmpf) {
1186 		unlink(tmppath);
1187 		if (fclose(tmpf) != 0 && err == NULL)
1188 			err = got_error_from_errno("fclose");
1189 	}
1190 	free(tmppath);
1191 	free(packed_refs_path);
1192 	got_ref_list_free(&refs);
1193 	return err ? err : unlock_err;
1194 }
1195 
1196 const struct got_error *
1197 got_ref_delete(struct got_reference *ref, struct got_repository *repo)
1198 {
1199 	const struct got_error *err = NULL, *unlock_err = NULL;
1200 	const char *name = got_ref_get_name(ref);
1201 	char *path_refs = NULL, *path = NULL;
1202 	struct got_lockfile *lf = NULL;
1203 
1204 	if (ref->flags & GOT_REF_IS_PACKED)
1205 		return delete_packed_ref(ref, repo);
1206 
1207 	path_refs = get_refs_dir_path(repo, name);
1208 	if (path_refs == NULL) {
1209 		err = got_error_from_errno2("get_refs_dir_path", name);
1210 		goto done;
1211 	}
1212 
1213 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1214 		err = got_error_from_errno("asprintf");
1215 		goto done;
1216 	}
1217 
1218 	if (ref->lf == NULL) {
1219 		err = got_lockfile_lock(&lf, path);
1220 		if (err)
1221 			goto done;
1222 	}
1223 
1224 	/* XXX: check if old content matches our expectations? */
1225 
1226 	if (unlink(path) != 0)
1227 		err = got_error_from_errno2("unlink", path);
1228 done:
1229 	if (ref->lf == NULL && lf)
1230 		unlock_err = got_lockfile_unlock(lf);
1231 
1232 	free(path_refs);
1233 	free(path);
1234 	return err ? err : unlock_err;
1235 }
1236 
1237 const struct got_error *
1238 got_ref_unlock(struct got_reference *ref)
1239 {
1240 	const struct got_error *err;
1241 	err = got_lockfile_unlock(ref->lf);
1242 	ref->lf = NULL;
1243 	return err;
1244 }