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/stat.h>
19 #include <sys/queue.h>
20 #include <sys/uio.h>
21 #include <sys/socket.h>
22 #include <sys/wait.h>
23 #include <sys/syslimits.h>
24 #include <sys/resource.h>
25 
26 #include <errno.h>
27 #include <fcntl.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <stdint.h>
32 #include <sha1.h>
33 #include <zlib.h>
34 #include <ctype.h>
35 #include <libgen.h>
36 #include <limits.h>
37 #include <imsg.h>
38 #include <time.h>
39 
40 #include "got_error.h"
41 #include "got_object.h"
42 #include "got_repository.h"
43 #include "got_opentemp.h"
44 #include "got_path.h"
45 
46 #include "got_lib_sha1.h"
47 #include "got_lib_delta.h"
48 #include "got_lib_inflate.h"
49 #include "got_lib_object.h"
50 #include "got_lib_privsep.h"
51 #include "got_lib_object_idcache.h"
52 #include "got_lib_object_cache.h"
53 #include "got_lib_object_parse.h"
54 #include "got_lib_pack.h"
55 #include "got_lib_repository.h"
56 
57 #ifndef MIN
58 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
59 #endif
60 
61 struct got_object_id *
62 got_object_get_id(struct got_object *obj)
63 {
64 	return &obj->id;
65 }
66 
67 const struct got_error *
68 got_object_get_id_str(char **outbuf, struct got_object *obj)
69 {
70 	return got_object_id_str(outbuf, &obj->id);
71 }
72 
73 const struct got_error *
74 got_object_get_type(int *type, struct got_repository *repo,
75     struct got_object_id *id)
76 {
77 	const struct got_error *err = NULL;
78 	struct got_object *obj;
79 
80 	err = got_object_open(&obj, repo, id);
81 	if (err)
82 		return err;
83 
84 	switch (obj->type) {
85 	case GOT_OBJ_TYPE_COMMIT:
86 	case GOT_OBJ_TYPE_TREE:
87 	case GOT_OBJ_TYPE_BLOB:
88 	case GOT_OBJ_TYPE_TAG:
89 		*type = obj->type;
90 		break;
91 	default:
92 		err = got_error(GOT_ERR_OBJ_TYPE);
93 		break;
94 	}
95 
96 	got_object_close(obj);
97 	return err;
98 }
99 
100 const struct got_error *
101 got_object_get_path(char **path, struct got_object_id *id,
102     struct got_repository *repo)
103 {
104 	const struct got_error *err = NULL;
105 	char *hex = NULL;
106 	char *path_objects;
107 
108 	*path = NULL;
109 
110 	path_objects = got_repo_get_path_objects(repo);
111 	if (path_objects == NULL)
112 		return got_error_from_errno("got_repo_get_path_objects");
113 
114 	err = got_object_id_str(&hex, id);
115 	if (err)
116 		goto done;
117 
118 	if (asprintf(path, "%s/%.2x/%s", path_objects,
119 	    id->sha1[0], hex + 2) == -1)
120 		err = got_error_from_errno("asprintf");
121 
122 done:
123 	free(hex);
124 	free(path_objects);
125 	return err;
126 }
127 
128 static const struct got_error *
129 open_loose_object(int *fd, struct got_object_id *id,
130     struct got_repository *repo)
131 {
132 	const struct got_error *err = NULL;
133 	char *path;
134 
135 	err = got_object_get_path(&path, id, repo);
136 	if (err)
137 		return err;
138 	*fd = open(path, O_RDONLY | O_NOFOLLOW);
139 	if (*fd == -1) {
140 		err = got_error_from_errno2("open", path);
141 		goto done;
142 	}
143 done:
144 	free(path);
145 	return err;
146 }
147 
148 static const struct got_error *
149 get_packfile_path(char **path_packfile, struct got_packidx *packidx)
150 {
151 	size_t size;
152 
153 	/* Packfile path contains ".pack" instead of ".idx", so add one byte. */
154 	size = strlen(packidx->path_packidx) + 2;
155 	if (size < GOT_PACKFILE_NAMELEN + 1)
156 		return got_error_path(packidx->path_packidx, GOT_ERR_BAD_PATH);
157 
158 	*path_packfile = malloc(size);
159 	if (*path_packfile == NULL)
160 		return got_error_from_errno("malloc");
161 
162 	/* Copy up to and excluding ".idx". */
163 	if (strlcpy(*path_packfile, packidx->path_packidx,
164 	    size - strlen(GOT_PACKIDX_SUFFIX) - 1) >= size)
165 		return got_error(GOT_ERR_NO_SPACE);
166 
167 	if (strlcat(*path_packfile, GOT_PACKFILE_SUFFIX, size) >= size)
168 		return got_error(GOT_ERR_NO_SPACE);
169 
170 	return NULL;
171 }
172 
173 static const struct got_error *
174 request_packed_object(struct got_object **obj, struct got_pack *pack, int idx,
175     struct got_object_id *id)
176 {
177 	const struct got_error *err = NULL;
178 	struct imsgbuf *ibuf = pack->privsep_child->ibuf;
179 
180 	err = got_privsep_send_packed_obj_req(ibuf, idx, id);
181 	if (err)
182 		return err;
183 
184 	err = got_privsep_recv_obj(obj, ibuf);
185 	if (err)
186 		return err;
187 
188 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
189 
190 	return NULL;
191 }
192 
193 static void
194 set_max_datasize(void)
195 {
196 	struct rlimit rl;
197 
198 	if (getrlimit(RLIMIT_DATA, &rl) != 0)
199 		return;
200 
201 	rl.rlim_cur = rl.rlim_max;
202 	setrlimit(RLIMIT_DATA, &rl);
203 }
204 
205 static const struct got_error *
206 start_pack_privsep_child(struct got_pack *pack, struct got_packidx *packidx)
207 {
208 	const struct got_error *err = NULL;
209 	int imsg_fds[2];
210 	pid_t pid;
211 	struct imsgbuf *ibuf;
212 
213 	ibuf = calloc(1, sizeof(*ibuf));
214 	if (ibuf == NULL)
215 		return got_error_from_errno("calloc");
216 
217 	pack->privsep_child = calloc(1, sizeof(*pack->privsep_child));
218 	if (pack->privsep_child == NULL) {
219 		err = got_error_from_errno("calloc");
220 		free(ibuf);
221 		return err;
222 	}
223 
224 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
225 		err = got_error_from_errno("socketpair");
226 		goto done;
227 	}
228 
229 	pid = fork();
230 	if (pid == -1) {
231 		err = got_error_from_errno("fork");
232 		goto done;
233 	} else if (pid == 0) {
234 		set_max_datasize();
235 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PACK,
236 		    pack->path_packfile);
237 		/* not reached */
238 	}
239 
240 	if (close(imsg_fds[1]) != 0)
241 		return got_error_from_errno("close");
242 	pack->privsep_child->imsg_fd = imsg_fds[0];
243 	pack->privsep_child->pid = pid;
244 	imsg_init(ibuf, imsg_fds[0]);
245 	pack->privsep_child->ibuf = ibuf;
246 
247 	err = got_privsep_init_pack_child(ibuf, pack, packidx);
248 	if (err) {
249 		const struct got_error *child_err;
250 		err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
251 		child_err = got_privsep_wait_for_child(
252 		    pack->privsep_child->pid);
253 		if (child_err && err == NULL)
254 			err = child_err;
255 	}
256 done:
257 	if (err) {
258 		free(ibuf);
259 		free(pack->privsep_child);
260 		pack->privsep_child = NULL;
261 	}
262 	return err;
263 }
264 
265 static const struct got_error *
266 read_packed_object_privsep(struct got_object **obj,
267     struct got_repository *repo, struct got_pack *pack,
268     struct got_packidx *packidx, int idx, struct got_object_id *id)
269 {
270 	const struct got_error *err = NULL;
271 
272 	if (pack->privsep_child)
273 		return request_packed_object(obj, pack, idx, id);
274 
275 	err = start_pack_privsep_child(pack, packidx);
276 	if (err)
277 		return err;
278 
279 	return request_packed_object(obj, pack, idx, id);
280 }
281 
282 
283 static const struct got_error *
284 open_packed_object(struct got_object **obj, struct got_object_id *id,
285     struct got_repository *repo)
286 {
287 	const struct got_error *err = NULL;
288 	struct got_pack *pack = NULL;
289 	struct got_packidx *packidx = NULL;
290 	int idx;
291 	char *path_packfile;
292 
293 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
294 	if (err)
295 		return err;
296 
297 	err = get_packfile_path(&path_packfile, packidx);
298 	if (err)
299 		return err;
300 
301 	pack = got_repo_get_cached_pack(repo, path_packfile);
302 	if (pack == NULL) {
303 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
304 		if (err)
305 			goto done;
306 	}
307 
308 	err = read_packed_object_privsep(obj, repo, pack, packidx, idx, id);
309 	if (err)
310 		goto done;
311 done:
312 	free(path_packfile);
313 	return err;
314 }
315 
316 static const struct got_error *
317 request_object(struct got_object **obj, struct got_repository *repo, int fd)
318 {
319 	const struct got_error *err = NULL;
320 	struct imsgbuf *ibuf;
321 
322 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf;
323 
324 	err = got_privsep_send_obj_req(ibuf, fd);
325 	if (err)
326 		return err;
327 
328 	return got_privsep_recv_obj(obj, ibuf);
329 }
330 
331 static const struct got_error *
332 read_object_header_privsep(struct got_object **obj, struct got_repository *repo,
333     int obj_fd)
334 {
335 	const struct got_error *err;
336 	int imsg_fds[2];
337 	pid_t pid;
338 	struct imsgbuf *ibuf;
339 
340 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd != -1)
341 		return request_object(obj, repo, obj_fd);
342 
343 	ibuf = calloc(1, sizeof(*ibuf));
344 	if (ibuf == NULL)
345 		return got_error_from_errno("calloc");
346 
347 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
348 		err = got_error_from_errno("socketpair");
349 		free(ibuf);
350 		return err;
351 	}
352 
353 	pid = fork();
354 	if (pid == -1) {
355 		err = got_error_from_errno("fork");
356 		free(ibuf);
357 		return err;
358 	}
359 	else if (pid == 0) {
360 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_OBJECT,
361 		    repo->path);
362 		/* not reached */
363 	}
364 
365 	if (close(imsg_fds[1]) != 0) {
366 		err = got_error_from_errno("close");
367 		free(ibuf);
368 		return err;
369 	}
370 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd =
371 	    imsg_fds[0];
372 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].pid = pid;
373 	imsg_init(ibuf, imsg_fds[0]);
374 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf = ibuf;
375 
376 	return request_object(obj, repo, obj_fd);
377 }
378 
379 
380 const struct got_error *
381 got_object_open(struct got_object **obj, struct got_repository *repo,
382     struct got_object_id *id)
383 {
384 	const struct got_error *err = NULL;
385 	char *path;
386 	int fd;
387 
388 	*obj = got_repo_get_cached_object(repo, id);
389 	if (*obj != NULL) {
390 		(*obj)->refcnt++;
391 		return NULL;
392 	}
393 
394 	err = open_packed_object(obj, id, repo);
395 	if (err && err->code != GOT_ERR_NO_OBJ)
396 		return err;
397 	if (*obj) {
398 		(*obj)->refcnt++;
399 		return got_repo_cache_object(repo, id, *obj);
400 	}
401 
402 	err = got_object_get_path(&path, id, repo);
403 	if (err)
404 		return err;
405 
406 	fd = open(path, O_RDONLY | O_NOFOLLOW);
407 	if (fd == -1) {
408 		if (errno == ENOENT)
409 			err = got_error_no_obj(id);
410 		else
411 			err = got_error_from_errno2("open", path);
412 		goto done;
413 	} else {
414 		err = read_object_header_privsep(obj, repo, fd);
415 		if (err)
416 			goto done;
417 		memcpy((*obj)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
418 	}
419 
420 	(*obj)->refcnt++;
421 	err = got_repo_cache_object(repo, id, *obj);
422 done:
423 	free(path);
424 	return err;
425 
426 }
427 
428 const struct got_error *
429 got_object_open_by_id_str(struct got_object **obj, struct got_repository *repo,
430     const char *id_str)
431 {
432 	struct got_object_id id;
433 
434 	if (!got_parse_sha1_digest(id.sha1, id_str))
435 		return got_error_path(id_str, GOT_ERR_BAD_OBJ_ID_STR);
436 
437 	return got_object_open(obj, repo, &id);
438 }
439 
440 const struct got_error *
441 got_object_resolve_id_str(struct got_object_id **id,
442     struct got_repository *repo, const char *id_str)
443 {
444 	const struct got_error *err = NULL;
445 	struct got_object *obj;
446 
447 	err = got_object_open_by_id_str(&obj, repo, id_str);
448 	if (err)
449 		return err;
450 
451 	*id = got_object_id_dup(got_object_get_id(obj));
452 	got_object_close(obj);
453 	if (*id == NULL)
454 		return got_error_from_errno("got_object_id_dup");
455 
456 	return NULL;
457 }
458 
459 static const struct got_error *
460 request_packed_commit(struct got_commit_object **commit, struct got_pack *pack,
461     int pack_idx, struct got_object_id *id)
462 {
463 	const struct got_error *err = NULL;
464 
465 	err = got_privsep_send_commit_req(pack->privsep_child->ibuf, -1, id,
466 	    pack_idx);
467 	if (err)
468 		return err;
469 
470 	err = got_privsep_recv_commit(commit, pack->privsep_child->ibuf);
471 	if (err)
472 		return err;
473 
474 	(*commit)->flags |= GOT_COMMIT_FLAG_PACKED;
475 	return NULL;
476 }
477 
478 static const struct got_error *
479 read_packed_commit_privsep(struct got_commit_object **commit,
480     struct got_pack *pack, struct got_packidx *packidx, int idx,
481     struct got_object_id *id)
482 {
483 	const struct got_error *err = NULL;
484 
485 	if (pack->privsep_child)
486 		return request_packed_commit(commit, pack, idx, id);
487 
488 	err = start_pack_privsep_child(pack, packidx);
489 	if (err)
490 		return err;
491 
492 	return request_packed_commit(commit, pack, idx, id);
493 }
494 
495 static const struct got_error *
496 request_commit(struct got_commit_object **commit, struct got_repository *repo,
497     int fd)
498 {
499 	const struct got_error *err = NULL;
500 	struct imsgbuf *ibuf;
501 
502 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf;
503 
504 	err = got_privsep_send_commit_req(ibuf, fd, NULL, -1);
505 	if (err)
506 		return err;
507 
508 	return got_privsep_recv_commit(commit, ibuf);
509 }
510 
511 static const struct got_error *
512 read_commit_privsep(struct got_commit_object **commit, int obj_fd,
513     struct got_repository *repo)
514 {
515 	const struct got_error *err;
516 	int imsg_fds[2];
517 	pid_t pid;
518 	struct imsgbuf *ibuf;
519 
520 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd != -1)
521 		return request_commit(commit, repo, obj_fd);
522 
523 	ibuf = calloc(1, sizeof(*ibuf));
524 	if (ibuf == NULL)
525 		return got_error_from_errno("calloc");
526 
527 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
528 		err = got_error_from_errno("socketpair");
529 		free(ibuf);
530 		return err;
531 	}
532 
533 	pid = fork();
534 	if (pid == -1) {
535 		err = got_error_from_errno("fork");
536 		free(ibuf);
537 		return err;
538 	}
539 	else if (pid == 0) {
540 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_COMMIT,
541 		    repo->path);
542 		/* not reached */
543 	}
544 
545 	if (close(imsg_fds[1]) != 0) {
546 		err = got_error_from_errno("close");
547 		free(ibuf);
548 		return err;
549 	}
550 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd =
551 	    imsg_fds[0];
552 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].pid = pid;
553 	imsg_init(ibuf, imsg_fds[0]);
554 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf = ibuf;
555 
556 	return request_commit(commit, repo, obj_fd);
557 }
558 
559 
560 static const struct got_error *
561 open_commit(struct got_commit_object **commit,
562     struct got_repository *repo, struct got_object_id *id, int check_cache)
563 {
564 	const struct got_error *err = NULL;
565 	struct got_packidx *packidx = NULL;
566 	int idx;
567 	char *path_packfile = NULL;
568 
569 	if (check_cache) {
570 		*commit = got_repo_get_cached_commit(repo, id);
571 		if (*commit != NULL) {
572 			(*commit)->refcnt++;
573 			return NULL;
574 		}
575 	} else
576 		*commit = NULL;
577 
578 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
579 	if (err == NULL) {
580 		struct got_pack *pack = NULL;
581 
582 		err = get_packfile_path(&path_packfile, packidx);
583 		if (err)
584 			return err;
585 
586 		pack = got_repo_get_cached_pack(repo, path_packfile);
587 		if (pack == NULL) {
588 			err = got_repo_cache_pack(&pack, repo, path_packfile,
589 			    packidx);
590 			if (err)
591 				goto done;
592 		}
593 		err = read_packed_commit_privsep(commit, pack,
594 		    packidx, idx, id);
595 	} else if (err->code == GOT_ERR_NO_OBJ) {
596 		int fd;
597 
598 		err = open_loose_object(&fd, id, repo);
599 		if (err)
600 			return err;
601 		err = read_commit_privsep(commit, fd, repo);
602 	}
603 
604 	if (err == NULL) {
605 		(*commit)->refcnt++;
606 		err = got_repo_cache_commit(repo, id, *commit);
607 	}
608 done:
609 	free(path_packfile);
610 	return err;
611 }
612 
613 const struct got_error *
614 got_object_open_as_commit(struct got_commit_object **commit,
615     struct got_repository *repo, struct got_object_id *id)
616 {
617 	*commit = got_repo_get_cached_commit(repo, id);
618 	if (*commit != NULL) {
619 		(*commit)->refcnt++;
620 		return NULL;
621 	}
622 
623 	return open_commit(commit, repo, id, 0);
624 }
625 
626 const struct got_error *
627 got_object_commit_open(struct got_commit_object **commit,
628     struct got_repository *repo, struct got_object *obj)
629 {
630 	return open_commit(commit, repo, got_object_get_id(obj), 1);
631 }
632 
633 const struct got_error *
634 got_object_qid_alloc(struct got_object_qid **qid, struct got_object_id *id)
635 {
636 	const struct got_error *err = NULL;
637 
638 	*qid = calloc(1, sizeof(**qid));
639 	if (*qid == NULL)
640 		return got_error_from_errno("calloc");
641 
642 	(*qid)->id = got_object_id_dup(id);
643 	if ((*qid)->id == NULL) {
644 		err = got_error_from_errno("got_object_id_dup");
645 		got_object_qid_free(*qid);
646 		*qid = NULL;
647 		return err;
648 	}
649 
650 	return NULL;
651 }
652 
653 static const struct got_error *
654 request_packed_tree(struct got_tree_object **tree, struct got_pack *pack,
655     int pack_idx, struct got_object_id *id)
656 {
657 	const struct got_error *err = NULL;
658 
659 	err = got_privsep_send_tree_req(pack->privsep_child->ibuf, -1, id,
660 	    pack_idx);
661 	if (err)
662 		return err;
663 
664 	return got_privsep_recv_tree(tree, pack->privsep_child->ibuf);
665 }
666 
667 static const struct got_error *
668 read_packed_tree_privsep(struct got_tree_object **tree,
669     struct got_pack *pack, struct got_packidx *packidx, int idx,
670     struct got_object_id *id)
671 {
672 	const struct got_error *err = NULL;
673 
674 	if (pack->privsep_child)
675 		return request_packed_tree(tree, pack, idx, id);
676 
677 	err = start_pack_privsep_child(pack, packidx);
678 	if (err)
679 		return err;
680 
681 	return request_packed_tree(tree, pack, idx, id);
682 }
683 
684 static const struct got_error *
685 request_tree(struct got_tree_object **tree, struct got_repository *repo,
686     int fd)
687 {
688 	const struct got_error *err = NULL;
689 	struct imsgbuf *ibuf;
690 
691 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf;
692 
693 	err = got_privsep_send_tree_req(ibuf, fd, NULL, -1);
694 	if (err)
695 		return err;
696 
697 	return got_privsep_recv_tree(tree, ibuf);
698 }
699 
700 const struct got_error *
701 read_tree_privsep(struct got_tree_object **tree, int obj_fd,
702     struct got_repository *repo)
703 {
704 	const struct got_error *err;
705 	int imsg_fds[2];
706 	pid_t pid;
707 	struct imsgbuf *ibuf;
708 
709 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd != -1)
710 		return request_tree(tree, repo, obj_fd);
711 
712 	ibuf = calloc(1, sizeof(*ibuf));
713 	if (ibuf == NULL)
714 		return got_error_from_errno("calloc");
715 
716 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
717 		err = got_error_from_errno("socketpair");
718 		free(ibuf);
719 		return err;
720 	}
721 
722 	pid = fork();
723 	if (pid == -1) {
724 		err = got_error_from_errno("fork");
725 		free(ibuf);
726 		return err;
727 	}
728 	else if (pid == 0) {
729 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TREE,
730 		    repo->path);
731 		/* not reached */
732 	}
733 
734 	if (close(imsg_fds[1]) != 0) {
735 		err = got_error_from_errno("close");
736 		free(ibuf);
737 		return err;
738 	}
739 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd =
740 	    imsg_fds[0];
741 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].pid = pid;
742 	imsg_init(ibuf, imsg_fds[0]);
743 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf = ibuf;
744 
745 
746 	return request_tree(tree, repo, obj_fd);
747 }
748 
749 static const struct got_error *
750 open_tree(struct got_tree_object **tree, struct got_repository *repo,
751     struct got_object_id *id, int check_cache)
752 {
753 	const struct got_error *err = NULL;
754 	struct got_packidx *packidx = NULL;
755 	int idx;
756 	char *path_packfile = NULL;
757 
758 	if (check_cache) {
759 		*tree = got_repo_get_cached_tree(repo, id);
760 		if (*tree != NULL) {
761 			(*tree)->refcnt++;
762 			return NULL;
763 		}
764 	} else
765 		*tree = NULL;
766 
767 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
768 	if (err == NULL) {
769 		struct got_pack *pack = NULL;
770 
771 		err = get_packfile_path(&path_packfile, packidx);
772 		if (err)
773 			return err;
774 
775 		pack = got_repo_get_cached_pack(repo, path_packfile);
776 		if (pack == NULL) {
777 			err = got_repo_cache_pack(&pack, repo, path_packfile,
778 			    packidx);
779 			if (err)
780 				goto done;
781 		}
782 		err = read_packed_tree_privsep(tree, pack,
783 		    packidx, idx, id);
784 	} else if (err->code == GOT_ERR_NO_OBJ) {
785 		int fd;
786 
787 		err = open_loose_object(&fd, id, repo);
788 		if (err)
789 			return err;
790 		err = read_tree_privsep(tree, fd, repo);
791 	}
792 
793 	if (err == NULL) {
794 		(*tree)->refcnt++;
795 		err = got_repo_cache_tree(repo, id, *tree);
796 	}
797 done:
798 	free(path_packfile);
799 	return err;
800 }
801 
802 const struct got_error *
803 got_object_open_as_tree(struct got_tree_object **tree,
804     struct got_repository *repo, struct got_object_id *id)
805 {
806 	*tree = got_repo_get_cached_tree(repo, id);
807 	if (*tree != NULL) {
808 		(*tree)->refcnt++;
809 		return NULL;
810 	}
811 
812 	return open_tree(tree, repo, id, 0);
813 }
814 
815 const struct got_error *
816 got_object_tree_open(struct got_tree_object **tree,
817     struct got_repository *repo, struct got_object *obj)
818 {
819 	return open_tree(tree, repo, got_object_get_id(obj), 1);
820 }
821 
822 int
823 got_object_tree_get_nentries(struct got_tree_object *tree)
824 {
825 	return tree->nentries;
826 }
827 
828 struct got_tree_entry *
829 got_object_tree_get_first_entry(struct got_tree_object *tree)
830 {
831 	return got_object_tree_get_entry(tree, 0);
832 }
833 
834 struct got_tree_entry *
835 got_object_tree_get_last_entry(struct got_tree_object *tree)
836 {
837 	return got_object_tree_get_entry(tree, tree->nentries - 1);
838 }
839 
840 struct got_tree_entry *
841 got_object_tree_get_entry(struct got_tree_object *tree, int i)
842 {
843 	if (i < 0 || i >= tree->nentries)
844 		return NULL;
845 	return &tree->entries[i];
846 }
847 
848 mode_t
849 got_tree_entry_get_mode(struct got_tree_entry *te)
850 {
851 	return te->mode;
852 }
853 
854 const char *
855 got_tree_entry_get_name(struct got_tree_entry *te)
856 {
857 	return &te->name[0];
858 }
859 
860 struct got_object_id *
861 got_tree_entry_get_id(struct got_tree_entry *te)
862 {
863 	return &te->id;
864 }
865 
866 const struct got_error *
867 got_tree_entry_get_symlink_target(char **link_target, struct got_tree_entry *te,
868     struct got_repository *repo)
869 {
870 	const struct got_error *err = NULL;
871 	struct got_blob_object *blob = NULL;
872 	size_t len, totlen, hdrlen;
873 
874 	*link_target = NULL;
875 
876 	if (!got_object_tree_entry_is_symlink(te))
877 		return got_error(GOT_ERR_TREE_ENTRY_TYPE);
878 
879 	err = got_object_open_as_blob(&blob, repo,
880 	    got_tree_entry_get_id(te), PATH_MAX);
881 	if (err)
882 		return err;
883 	hdrlen = got_object_blob_get_hdrlen(blob);
884 	totlen = 0;
885 	do {
886 		char *p;
887 
888 		err = got_object_blob_read_block(&len, blob);
889 		if (err)
890 			goto done;
891 
892 		if (len == 0)
893 			break;
894 
895 		totlen += len - hdrlen;
896 		p = realloc(*link_target, totlen + 1);
897 		if (p == NULL) {
898 			err = got_error_from_errno("realloc");
899 			goto done;
900 		}
901 		*link_target = p;
902 		/* Skip blob object header first time around. */
903 		memcpy(*link_target,
904 		    got_object_blob_get_read_buf(blob) + hdrlen, len);
905 		hdrlen = 0;
906 	} while (len > 0);
907 	(*link_target)[totlen] = '\0';
908 done:
909 	if (blob)
910 		got_object_blob_close(blob);
911 	if (err) {
912 		free(*link_target);
913 		*link_target = NULL;
914 	}
915 	return err;
916 }
917 
918 int
919 got_tree_entry_get_index(struct got_tree_entry *te)
920 {
921 	return te->idx;
922 }
923 
924 struct got_tree_entry *
925 got_tree_entry_get_next(struct got_tree_object *tree,
926     struct got_tree_entry *te)
927 {
928 	return got_object_tree_get_entry(tree, te->idx + 1);
929 }
930 
931 struct got_tree_entry *
932 got_tree_entry_get_prev(struct got_tree_object *tree,
933     struct got_tree_entry *te)
934 {
935 	return got_object_tree_get_entry(tree, te->idx - 1);
936 }
937 
938 static const struct got_error *
939 request_packed_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
940     struct got_pack *pack, struct got_packidx *packidx, int idx,
941     struct got_object_id *id)
942 {
943 	const struct got_error *err = NULL;
944 	int outfd_child;
945 	int basefd, accumfd; /* temporary files for delta application */
946 
947 	basefd = got_opentempfd();
948 	if (basefd == -1)
949 		return got_error_from_errno("got_opentempfd");
950 	accumfd = got_opentempfd();
951 	if (accumfd == -1)
952 		return got_error_from_errno("got_opentempfd");
953 
954 	outfd_child = dup(outfd);
955 	if (outfd_child == -1)
956 		return got_error_from_errno("dup");
957 
958 	err = got_privsep_send_blob_req(pack->privsep_child->ibuf, -1, id, idx);
959 	if (err)
960 		return err;
961 
962 	err = got_privsep_send_blob_outfd(pack->privsep_child->ibuf,
963 	    outfd_child);
964 	if (err) {
965 		close(basefd);
966 		close(accumfd);
967 		return err;
968 	}
969 
970 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
971 	    basefd);
972 	if (err) {
973 		close(accumfd);
974 		return err;
975 	}
976 
977 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
978 	    accumfd);
979 	if (err)
980 		return err;
981 
982 	err = got_privsep_recv_blob(outbuf, size, hdrlen,
983 	    pack->privsep_child->ibuf);
984 	if (err)
985 		return err;
986 
987 	if (lseek(outfd, SEEK_SET, 0) == -1)
988 		err = got_error_from_errno("lseek");
989 
990 	return err;
991 }
992 
993 static const struct got_error *
994 read_packed_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
995     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
996     struct got_object_id *id)
997 {
998 	const struct got_error *err = NULL;
999 
1000 	if (pack->privsep_child == NULL) {
1001 		err = start_pack_privsep_child(pack, packidx);
1002 		if (err)
1003 			return err;
1004 	}
1005 
1006 	return request_packed_blob(outbuf, size, hdrlen, outfd, pack, packidx,
1007 	    idx, id);
1008 }
1009 
1010 static const struct got_error *
1011 request_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
1012     int infd, struct imsgbuf *ibuf)
1013 {
1014 	const struct got_error *err = NULL;
1015 	int outfd_child;
1016 
1017 	outfd_child = dup(outfd);
1018 	if (outfd_child == -1)
1019 		return got_error_from_errno("dup");
1020 
1021 	err = got_privsep_send_blob_req(ibuf, infd, NULL, -1);
1022 	if (err)
1023 		return err;
1024 
1025 	err = got_privsep_send_blob_outfd(ibuf, outfd_child);
1026 	if (err)
1027 		return err;
1028 
1029 	err = got_privsep_recv_blob(outbuf, size, hdrlen, ibuf);
1030 	if (err)
1031 		return err;
1032 
1033 	if (lseek(outfd, SEEK_SET, 0) == -1)
1034 		return got_error_from_errno("lseek");
1035 
1036 	return err;
1037 }
1038 
1039 static const struct got_error *
1040 read_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1041     int outfd, int infd, struct got_repository *repo)
1042 {
1043 	const struct got_error *err;
1044 	int imsg_fds[2];
1045 	pid_t pid;
1046 	struct imsgbuf *ibuf;
1047 
1048 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd != -1) {
1049 		ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf;
1050 		return request_blob(outbuf, size, hdrlen, outfd, infd, ibuf);
1051 	}
1052 
1053 	ibuf = calloc(1, sizeof(*ibuf));
1054 	if (ibuf == NULL)
1055 		return got_error_from_errno("calloc");
1056 
1057 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1058 		err = got_error_from_errno("socketpair");
1059 		free(ibuf);
1060 		return err;
1061 	}
1062 
1063 	pid = fork();
1064 	if (pid == -1) {
1065 		err = got_error_from_errno("fork");
1066 		free(ibuf);
1067 		return err;
1068 	}
1069 	else if (pid == 0) {
1070 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_BLOB,
1071 		    repo->path);
1072 		/* not reached */
1073 	}
1074 
1075 	if (close(imsg_fds[1]) != 0) {
1076 		err = got_error_from_errno("close");
1077 		free(ibuf);
1078 		return err;
1079 	}
1080 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd =
1081 	    imsg_fds[0];
1082 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].pid = pid;
1083 	imsg_init(ibuf, imsg_fds[0]);
1084 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf = ibuf;
1085 
1086 	return request_blob(outbuf, size, hdrlen, outfd, infd, ibuf);
1087 }
1088 
1089 static const struct got_error *
1090 open_blob(struct got_blob_object **blob, struct got_repository *repo,
1091     struct got_object_id *id, size_t blocksize)
1092 {
1093 	const struct got_error *err = NULL;
1094 	struct got_packidx *packidx = NULL;
1095 	int idx;
1096 	char *path_packfile = NULL;
1097 	uint8_t *outbuf;
1098 	int outfd;
1099 	size_t size, hdrlen;
1100 	struct stat sb;
1101 
1102 	*blob = calloc(1, sizeof(**blob));
1103 	if (*blob == NULL)
1104 		return got_error_from_errno("calloc");
1105 
1106 	outfd = got_opentempfd();
1107 	if (outfd == -1)
1108 		return got_error_from_errno("got_opentempfd");
1109 
1110 	(*blob)->read_buf = malloc(blocksize);
1111 	if ((*blob)->read_buf == NULL) {
1112 		err = got_error_from_errno("malloc");
1113 		goto done;
1114 	}
1115 
1116 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1117 	if (err == NULL) {
1118 		struct got_pack *pack = NULL;
1119 
1120 		err = get_packfile_path(&path_packfile, packidx);
1121 		if (err)
1122 			goto done;
1123 
1124 		pack = got_repo_get_cached_pack(repo, path_packfile);
1125 		if (pack == NULL) {
1126 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1127 			    packidx);
1128 			if (err)
1129 				goto done;
1130 		}
1131 		err = read_packed_blob_privsep(&outbuf, &size, &hdrlen, outfd,
1132 		    pack, packidx, idx, id);
1133 	} else if (err->code == GOT_ERR_NO_OBJ) {
1134 		int infd;
1135 
1136 		err = open_loose_object(&infd, id, repo);
1137 		if (err)
1138 			goto done;
1139 		err = read_blob_privsep(&outbuf, &size, &hdrlen, outfd, infd,
1140 		    repo);
1141 	}
1142 	if (err)
1143 		goto done;
1144 
1145 	if (hdrlen > size) {
1146 		err = got_error(GOT_ERR_BAD_OBJ_HDR);
1147 		goto done;
1148 	}
1149 
1150 	if (outbuf) {
1151 		if (close(outfd) != 0 && err == NULL)
1152 			err = got_error_from_errno("close");
1153 		outfd = -1;
1154 		(*blob)->f = fmemopen(outbuf, size, "rb");
1155 		if ((*blob)->f == NULL) {
1156 			err = got_error_from_errno("fmemopen");
1157 			free(outbuf);
1158 			goto done;
1159 		}
1160 		(*blob)->data = outbuf;
1161 	} else {
1162 		if (fstat(outfd, &sb) == -1) {
1163 			err = got_error_from_errno("fstat");
1164 			goto done;
1165 		}
1166 
1167 		if (sb.st_size != size) {
1168 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1169 			goto done;
1170 		}
1171 
1172 		(*blob)->f = fdopen(outfd, "rb");
1173 		if ((*blob)->f == NULL) {
1174 			err = got_error_from_errno("fdopen");
1175 			close(outfd);
1176 			outfd = -1;
1177 			goto done;
1178 		}
1179 	}
1180 
1181 	(*blob)->hdrlen = hdrlen;
1182 	(*blob)->blocksize = blocksize;
1183 	memcpy(&(*blob)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
1184 
1185 done:
1186 	free(path_packfile);
1187 	if (err) {
1188 		if (*blob) {
1189 			got_object_blob_close(*blob);
1190 			*blob = NULL;
1191 		} else if (outfd != -1)
1192 			close(outfd);
1193 	}
1194 	return err;
1195 }
1196 
1197 const struct got_error *
1198 got_object_open_as_blob(struct got_blob_object **blob,
1199     struct got_repository *repo, struct got_object_id *id,
1200     size_t blocksize)
1201 {
1202 	return open_blob(blob, repo, id, blocksize);
1203 }
1204 
1205 const struct got_error *
1206 got_object_blob_open(struct got_blob_object **blob,
1207     struct got_repository *repo, struct got_object *obj, size_t blocksize)
1208 {
1209 	return open_blob(blob, repo, got_object_get_id(obj), blocksize);
1210 }
1211 
1212 const struct got_error *
1213 got_object_blob_close(struct got_blob_object *blob)
1214 {
1215 	const struct got_error *err = NULL;
1216 	free(blob->read_buf);
1217 	if (blob->f && fclose(blob->f) != 0)
1218 		err = got_error_from_errno("fclose");
1219 	free(blob->data);
1220 	free(blob);
1221 	return err;
1222 }
1223 
1224 void
1225 got_object_blob_rewind(struct got_blob_object *blob)
1226 {
1227 	if (blob->f)
1228 		rewind(blob->f);
1229 }
1230 
1231 char *
1232 got_object_blob_id_str(struct got_blob_object *blob, char *buf, size_t size)
1233 {
1234 	return got_sha1_digest_to_str(blob->id.sha1, buf, size);
1235 }
1236 
1237 size_t
1238 got_object_blob_get_hdrlen(struct got_blob_object *blob)
1239 {
1240 	return blob->hdrlen;
1241 }
1242 
1243 const uint8_t *
1244 got_object_blob_get_read_buf(struct got_blob_object *blob)
1245 {
1246 	return blob->read_buf;
1247 }
1248 
1249 const struct got_error *
1250 got_object_blob_read_block(size_t *outlenp, struct got_blob_object *blob)
1251 {
1252 	size_t n;
1253 
1254 	n = fread(blob->read_buf, 1, blob->blocksize, blob->f);
1255 	if (n == 0 && ferror(blob->f))
1256 		return got_ferror(blob->f, GOT_ERR_IO);
1257 	*outlenp = n;
1258 	return NULL;
1259 }
1260 
1261 const struct got_error *
1262 got_object_blob_dump_to_file(size_t *filesize, int *nlines,
1263     off_t **line_offsets, FILE *outfile, struct got_blob_object *blob)
1264 {
1265 	const struct got_error *err = NULL;
1266 	size_t n, len, hdrlen;
1267 	const uint8_t *buf;
1268 	int i;
1269 	size_t noffsets = 0;
1270 	off_t off = 0, total_len = 0;
1271 
1272 	if (line_offsets)
1273 		*line_offsets = NULL;
1274 	if (filesize)
1275 		*filesize = 0;
1276 	if (nlines)
1277 		*nlines = 0;
1278 
1279 	hdrlen = got_object_blob_get_hdrlen(blob);
1280 	do {
1281 		err = got_object_blob_read_block(&len, blob);
1282 		if (err)
1283 			return err;
1284 		if (len == 0)
1285 			break;
1286 		buf = got_object_blob_get_read_buf(blob);
1287 		i = hdrlen;
1288 		if (line_offsets && nlines) {
1289 			if (*line_offsets == NULL) {
1290 				/* Have some data but perhaps no '\n'. */
1291 				noffsets = 1;
1292 				*nlines = 1;
1293 				*line_offsets = calloc(1, sizeof(**line_offsets));
1294 				if (*line_offsets == NULL)
1295 					return got_error_from_errno("calloc");
1296 
1297 				/* Skip forward over end of first line. */
1298 				while (i < len) {
1299 					if (buf[i] == '\n')
1300 						break;
1301 					i++;
1302 				}
1303 			}
1304 			/* Scan '\n' offsets in remaining chunk of data. */
1305 			while (i < len) {
1306 				if (buf[i] != '\n') {
1307 					i++;
1308 					continue;
1309 				}
1310 				(*nlines)++;
1311 				if (noffsets < *nlines) {
1312 					off_t *o = recallocarray(*line_offsets,
1313 					    noffsets, *nlines,
1314 					    sizeof(**line_offsets));
1315 					if (o == NULL) {
1316 						free(*line_offsets);
1317 						*line_offsets = NULL;
1318 						return got_error_from_errno(
1319 						    "recallocarray");
1320 					}
1321 					*line_offsets = o;
1322 					noffsets = *nlines;
1323 				}
1324 				off = total_len + i - hdrlen + 1;
1325 				(*line_offsets)[*nlines - 1] = off;
1326 				i++;
1327 			}
1328 		}
1329 		/* Skip blob object header first time around. */
1330 		n = fwrite(buf + hdrlen, 1, len - hdrlen, outfile);
1331 		if (n != len - hdrlen)
1332 			return got_ferror(outfile, GOT_ERR_IO);
1333 		total_len += len - hdrlen;
1334 		hdrlen = 0;
1335 	} while (len != 0);
1336 
1337 	if (fflush(outfile) != 0)
1338 		return got_error_from_errno("fflush");
1339 	rewind(outfile);
1340 
1341 	if (filesize)
1342 		*filesize = total_len;
1343 
1344 	return NULL;
1345 }
1346 
1347 static const struct got_error *
1348 request_packed_tag(struct got_tag_object **tag, struct got_pack *pack,
1349     int pack_idx, struct got_object_id *id)
1350 {
1351 	const struct got_error *err = NULL;
1352 
1353 	err = got_privsep_send_tag_req(pack->privsep_child->ibuf, -1, id,
1354 	    pack_idx);
1355 	if (err)
1356 		return err;
1357 
1358 	return got_privsep_recv_tag(tag, pack->privsep_child->ibuf);
1359 }
1360 
1361 static const struct got_error *
1362 read_packed_tag_privsep(struct got_tag_object **tag,
1363     struct got_pack *pack, struct got_packidx *packidx, int idx,
1364     struct got_object_id *id)
1365 {
1366 	const struct got_error *err = NULL;
1367 
1368 	if (pack->privsep_child)
1369 		return request_packed_tag(tag, pack, idx, id);
1370 
1371 	err = start_pack_privsep_child(pack, packidx);
1372 	if (err)
1373 		return err;
1374 
1375 	return request_packed_tag(tag, pack, idx, id);
1376 }
1377 
1378 static const struct got_error *
1379 request_tag(struct got_tag_object **tag, struct got_repository *repo,
1380     int fd)
1381 {
1382 	const struct got_error *err = NULL;
1383 	struct imsgbuf *ibuf;
1384 
1385 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf;
1386 
1387 	err = got_privsep_send_tag_req(ibuf, fd, NULL, -1);
1388 	if (err)
1389 		return err;
1390 
1391 	return got_privsep_recv_tag(tag, ibuf);
1392 }
1393 
1394 static const struct got_error *
1395 read_tag_privsep(struct got_tag_object **tag, int obj_fd,
1396     struct got_repository *repo)
1397 {
1398 	const struct got_error *err;
1399 	int imsg_fds[2];
1400 	pid_t pid;
1401 	struct imsgbuf *ibuf;
1402 
1403 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd != -1)
1404 		return request_tag(tag, repo, obj_fd);
1405 
1406 	ibuf = calloc(1, sizeof(*ibuf));
1407 	if (ibuf == NULL)
1408 		return got_error_from_errno("calloc");
1409 
1410 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1411 		err = got_error_from_errno("socketpair");
1412 		free(ibuf);
1413 		return err;
1414 	}
1415 
1416 	pid = fork();
1417 	if (pid == -1) {
1418 		err = got_error_from_errno("fork");
1419 		free(ibuf);
1420 		return err;
1421 	}
1422 	else if (pid == 0) {
1423 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TAG,
1424 		    repo->path);
1425 		/* not reached */
1426 	}
1427 
1428 	if (close(imsg_fds[1]) != 0) {
1429 		err = got_error_from_errno("close");
1430 		free(ibuf);
1431 		return err;
1432 	}
1433 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd =
1434 	    imsg_fds[0];
1435 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].pid = pid;
1436 	imsg_init(ibuf, imsg_fds[0]);
1437 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf = ibuf;
1438 
1439 	return request_tag(tag, repo, obj_fd);
1440 }
1441 
1442 static const struct got_error *
1443 open_tag(struct got_tag_object **tag, struct got_repository *repo,
1444     struct got_object_id *id, int check_cache)
1445 {
1446 	const struct got_error *err = NULL;
1447 	struct got_packidx *packidx = NULL;
1448 	int idx;
1449 	char *path_packfile = NULL;
1450 	struct got_object *obj = NULL;
1451 	int obj_type = GOT_OBJ_TYPE_ANY;
1452 
1453 	if (check_cache) {
1454 		*tag = got_repo_get_cached_tag(repo, id);
1455 		if (*tag != NULL) {
1456 			(*tag)->refcnt++;
1457 			return NULL;
1458 		}
1459 	} else
1460 		*tag = NULL;
1461 
1462 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1463 	if (err == NULL) {
1464 		struct got_pack *pack = NULL;
1465 
1466 		err = get_packfile_path(&path_packfile, packidx);
1467 		if (err)
1468 			return err;
1469 
1470 		pack = got_repo_get_cached_pack(repo, path_packfile);
1471 		if (pack == NULL) {
1472 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1473 			    packidx);
1474 			if (err)
1475 				goto done;
1476 		}
1477 
1478 		/* Beware of "lightweight" tags: Check object type first. */
1479 		err = read_packed_object_privsep(&obj, repo, pack, packidx,
1480 		    idx, id);
1481 		if (err)
1482 			goto done;
1483 		obj_type = obj->type;
1484 		got_object_close(obj);
1485 		if (obj_type != GOT_OBJ_TYPE_TAG) {
1486 			err = got_error(GOT_ERR_OBJ_TYPE);
1487 			goto done;
1488 		}
1489 		err = read_packed_tag_privsep(tag, pack, packidx, idx, id);
1490 	} else if (err->code == GOT_ERR_NO_OBJ) {
1491 		int fd;
1492 
1493 		err = open_loose_object(&fd, id, repo);
1494 		if (err)
1495 			return err;
1496 		err = read_object_header_privsep(&obj, repo, fd);
1497 		if (err)
1498 			return err;
1499 		obj_type = obj->type;
1500 		got_object_close(obj);
1501 		if (obj_type != GOT_OBJ_TYPE_TAG)
1502 			return got_error(GOT_ERR_OBJ_TYPE);
1503 
1504 		err = open_loose_object(&fd, id, repo);
1505 		if (err)
1506 			return err;
1507 		err = read_tag_privsep(tag, fd, repo);
1508 	}
1509 
1510 	if (err == NULL) {
1511 		(*tag)->refcnt++;
1512 		err = got_repo_cache_tag(repo, id, *tag);
1513 	}
1514 done:
1515 	free(path_packfile);
1516 	return err;
1517 }
1518 
1519 const struct got_error *
1520 got_object_open_as_tag(struct got_tag_object **tag,
1521     struct got_repository *repo, struct got_object_id *id)
1522 {
1523 	*tag = got_repo_get_cached_tag(repo, id);
1524 	if (*tag != NULL) {
1525 		(*tag)->refcnt++;
1526 		return NULL;
1527 	}
1528 
1529 	return open_tag(tag, repo, id, 0);
1530 }
1531 
1532 const struct got_error *
1533 got_object_tag_open(struct got_tag_object **tag,
1534     struct got_repository *repo, struct got_object *obj)
1535 {
1536 	return open_tag(tag, repo, got_object_get_id(obj), 1);
1537 }
1538 
1539 const char *
1540 got_object_tag_get_name(struct got_tag_object *tag)
1541 {
1542 	return tag->tag;
1543 }
1544 
1545 int
1546 got_object_tag_get_object_type(struct got_tag_object *tag)
1547 {
1548 	return tag->obj_type;
1549 }
1550 
1551 struct got_object_id *
1552 got_object_tag_get_object_id(struct got_tag_object *tag)
1553 {
1554 	return &tag->id;
1555 }
1556 
1557 time_t
1558 got_object_tag_get_tagger_time(struct got_tag_object *tag)
1559 {
1560 	return tag->tagger_time;
1561 }
1562 
1563 time_t
1564 got_object_tag_get_tagger_gmtoff(struct got_tag_object *tag)
1565 {
1566 	return tag->tagger_gmtoff;
1567 }
1568 
1569 const char *
1570 got_object_tag_get_tagger(struct got_tag_object *tag)
1571 {
1572 	return tag->tagger;
1573 }
1574 
1575 const char *
1576 got_object_tag_get_message(struct got_tag_object *tag)
1577 {
1578 	return tag->tagmsg;
1579 }
1580 
1581 static struct got_tree_entry *
1582 find_entry_by_name(struct got_tree_object *tree, const char *name, size_t len)
1583 {
1584 	int i;
1585 
1586 	/* Note that tree entries are sorted in strncmp() order. */
1587 	for (i = 0; i < tree->nentries; i++) {
1588 		struct got_tree_entry *te = &tree->entries[i];
1589 		int cmp = strncmp(te->name, name, len);
1590 		if (cmp < 0)
1591 			continue;
1592 		if (cmp > 0)
1593 			break;
1594 		if (te->name[len] == '\0')
1595 			return te;
1596 	}
1597 	return NULL;
1598 }
1599 
1600 struct got_tree_entry *
1601 got_object_tree_find_entry(struct got_tree_object *tree, const char *name)
1602 {
1603 	return find_entry_by_name(tree, name, strlen(name));
1604 }
1605 
1606 const struct got_error *
1607 got_object_id_by_path(struct got_object_id **id, struct got_repository *repo,
1608     struct got_object_id *commit_id, const char *path)
1609 {
1610 	const struct got_error *err = NULL;
1611 	struct got_commit_object *commit = NULL;
1612 	struct got_tree_object *tree = NULL;
1613 	struct got_tree_entry *te = NULL;
1614 	const char *seg, *s;
1615 	size_t seglen;
1616 
1617 	*id = NULL;
1618 
1619 	err = got_object_open_as_commit(&commit, repo, commit_id);
1620 	if (err)
1621 		goto done;
1622 
1623 	/* Handle opening of root of commit's tree. */
1624 	if (got_path_is_root_dir(path)) {
1625 		*id = got_object_id_dup(commit->tree_id);
1626 		if (*id == NULL)
1627 			err = got_error_from_errno("got_object_id_dup");
1628 		goto done;
1629 	}
1630 
1631 	err = got_object_open_as_tree(&tree, repo, commit->tree_id);
1632 	if (err)
1633 		goto done;
1634 
1635 	s = path;
1636 	while (s[0] == '/')
1637 		s++;
1638 	seg = s;
1639 	seglen = 0;
1640 	while (*s) {
1641 		struct got_tree_object *next_tree;
1642 
1643 		if (*s != '/') {
1644 			s++;
1645 			seglen++;
1646 			if (*s)
1647 				continue;
1648 		}
1649 
1650 		te = find_entry_by_name(tree, seg, seglen);
1651 		if (te == NULL) {
1652 			err = got_error(GOT_ERR_NO_TREE_ENTRY);
1653 			goto done;
1654 		}
1655 
1656 		if (*s == '\0')
1657 			break;
1658 
1659 		seg = s + 1;
1660 		seglen = 0;
1661 		s++;
1662 		if (*s) {
1663 			err = got_object_open_as_tree(&next_tree, repo,
1664 			    &te->id);
1665 			te = NULL;
1666 			if (err)
1667 				goto done;
1668 			got_object_tree_close(tree);
1669 			tree = next_tree;
1670 		}
1671 	}
1672 
1673 	if (te) {
1674 		*id = got_object_id_dup(&te->id);
1675 		if (*id == NULL)
1676 			return got_error_from_errno("got_object_id_dup");
1677 	} else
1678 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
1679 done:
1680 	if (commit)
1681 		got_object_commit_close(commit);
1682 	if (tree)
1683 		got_object_tree_close(tree);
1684 	return err;
1685 }
1686 
1687 /*
1688  * Normalize file mode bits to avoid false positive tree entry differences
1689  * in case tree entries have unexpected mode bits set.
1690  */
1691 static mode_t
1692 normalize_mode_for_comparison(mode_t mode)
1693 {
1694 	/*
1695 	 * For directories, the only relevant bit is the IFDIR bit.
1696 	 * This allows us to detect paths changing from a directory
1697 	 * to a file and vice versa.
1698 	 */
1699 	if (S_ISDIR(mode))
1700 		return mode & S_IFDIR;
1701 
1702 	/* For files, the only change we care about is the executable bit. */
1703 	return mode & S_IXUSR;
1704 }
1705 
1706 const struct got_error *
1707 got_object_tree_path_changed(int *changed,
1708     struct got_tree_object *tree01, struct got_tree_object *tree02,
1709     const char *path, struct got_repository *repo)
1710 {
1711 	const struct got_error *err = NULL;
1712 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
1713 	struct got_tree_entry *te1 = NULL, *te2 = NULL;
1714 	const char *seg, *s;
1715 	size_t seglen;
1716 
1717 	*changed = 0;
1718 
1719 	/* We not do support comparing the root path. */
1720 	if (got_path_is_root_dir(path))
1721 		return got_error_path(path, GOT_ERR_BAD_PATH);
1722 
1723 	tree1 = tree01;
1724 	tree2 = tree02;
1725 	s = path;
1726 	while (*s == '/')
1727 		s++;
1728 	seg = s;
1729 	seglen = 0;
1730 	while (*s) {
1731 		struct got_tree_object *next_tree1, *next_tree2;
1732 		mode_t mode1, mode2;
1733 
1734 		if (*s != '/') {
1735 			s++;
1736 			seglen++;
1737 			if (*s)
1738 				continue;
1739 		}
1740 
1741 		te1 = find_entry_by_name(tree1, seg, seglen);
1742 		if (te1 == NULL) {
1743 			err = got_error(GOT_ERR_NO_OBJ);
1744 			goto done;
1745 		}
1746 
1747 		te2 = find_entry_by_name(tree2, seg, seglen);
1748 		if (te2 == NULL) {
1749 			*changed = 1;
1750 			goto done;
1751 		}
1752 
1753 		mode1 = normalize_mode_for_comparison(te1->mode);
1754 		mode2 = normalize_mode_for_comparison(te2->mode);
1755 		if (mode1 != mode2) {
1756 			*changed = 1;
1757 			goto done;
1758 		}
1759 
1760 		if (got_object_id_cmp(&te1->id, &te2->id) == 0) {
1761 			*changed = 0;
1762 			goto done;
1763 		}
1764 
1765 		if (*s == '\0') { /* final path element */
1766 			*changed = 1;
1767 			goto done;
1768 		}
1769 
1770 		seg = s + 1;
1771 		s++;
1772 		seglen = 0;
1773 		if (*s) {
1774 			err = got_object_open_as_tree(&next_tree1, repo,
1775 			    &te1->id);
1776 			te1 = NULL;
1777 			if (err)
1778 				goto done;
1779 			if (tree1 != tree01)
1780 				got_object_tree_close(tree1);
1781 			tree1 = next_tree1;
1782 
1783 			err = got_object_open_as_tree(&next_tree2, repo,
1784 			    &te2->id);
1785 			te2 = NULL;
1786 			if (err)
1787 				goto done;
1788 			if (tree2 != tree02)
1789 				got_object_tree_close(tree2);
1790 			tree2 = next_tree2;
1791 		}
1792 	}
1793 done:
1794 	if (tree1 && tree1 != tree01)
1795 		got_object_tree_close(tree1);
1796 	if (tree2 && tree2 != tree02)
1797 		got_object_tree_close(tree2);
1798 	return err;
1799 }
1800 
1801 const struct got_error *
1802 got_object_tree_entry_dup(struct got_tree_entry **new_te,
1803     struct got_tree_entry *te)
1804 {
1805 	const struct got_error *err = NULL;
1806 
1807 	*new_te = calloc(1, sizeof(**new_te));
1808 	if (*new_te == NULL)
1809 		return got_error_from_errno("calloc");
1810 
1811 	(*new_te)->mode = te->mode;
1812 	memcpy((*new_te)->name, te->name, sizeof((*new_te)->name));
1813 	memcpy(&(*new_te)->id, &te->id, sizeof((*new_te)->id));
1814 	return err;
1815 }
1816 
1817 int
1818 got_object_tree_entry_is_submodule(struct got_tree_entry *te)
1819 {
1820 	return (te->mode & S_IFMT) == (S_IFDIR | S_IFLNK);
1821 }
1822 
1823 int
1824 got_object_tree_entry_is_symlink(struct got_tree_entry *te)
1825 {
1826 	/* S_IFDIR check avoids confusing symlinks with submodules. */
1827 	return ((te->mode & (S_IFDIR | S_IFLNK)) == S_IFLNK);
1828 }
1829 
1830 static const struct got_error *
1831 resolve_symlink(char **link_target, const char *path,
1832     struct got_object_id *commit_id, struct got_repository *repo)
1833 {
1834 	const struct got_error *err = NULL;
1835 	char *name, *parent_path = NULL;
1836 	struct got_object_id *tree_obj_id = NULL;
1837 	struct got_tree_object *tree = NULL;
1838 	struct got_tree_entry *te = NULL;
1839 
1840 	*link_target = NULL;
1841 	
1842 	name = basename(path);
1843 	if (name == NULL)
1844 		return got_error_from_errno2("basename", path);
1845 
1846 	err = got_path_dirname(&parent_path, path);
1847 	if (err)
1848 		return err;
1849 
1850 	err = got_object_id_by_path(&tree_obj_id, repo, commit_id,
1851 	    parent_path);
1852 	if (err) {
1853 		if (err->code == GOT_ERR_NO_TREE_ENTRY) {
1854 			/* Display the complete path in error message. */
1855 			err = got_error_path(path, err->code);
1856 		}
1857 		goto done;
1858 	}
1859 
1860 	err = got_object_open_as_tree(&tree, repo, tree_obj_id);
1861 	if (err)
1862 		goto done;
1863 
1864 	te = got_object_tree_find_entry(tree, name);
1865 	if (te == NULL) {
1866 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
1867 		goto done;
1868 	}
1869 
1870 	if (got_object_tree_entry_is_symlink(te)) {
1871 		err = got_tree_entry_get_symlink_target(link_target, te, repo);
1872 		if (err)
1873 			goto done;
1874 		if (!got_path_is_absolute(*link_target)) {
1875 			char *abspath;
1876 			if (asprintf(&abspath, "%s/%s", parent_path,
1877 			    *link_target) == -1) {
1878 				err = got_error_from_errno("asprintf");
1879 				goto done;
1880 			}
1881 			free(*link_target);
1882 			*link_target = malloc(PATH_MAX);
1883 			if (*link_target == NULL) {
1884 				err = got_error_from_errno("malloc");
1885 				goto done;
1886 			}
1887 			err = got_canonpath(abspath, *link_target, PATH_MAX);
1888 			free(abspath);
1889 			if (err)
1890 				goto done;
1891 		}
1892 	}
1893 done:
1894 	free(tree_obj_id);
1895 	if (tree)
1896 		got_object_tree_close(tree);
1897 	if (err) {
1898 		free(*link_target);
1899 		*link_target = NULL;
1900 	}
1901 	return err;
1902 }
1903 
1904 const struct got_error *
1905 got_object_resolve_symlinks(char **link_target, const char *path,
1906     struct got_object_id *commit_id, struct got_repository *repo)
1907 {
1908 	const struct got_error *err = NULL;
1909 	char *next_target = NULL;
1910 	int max_recursion = 40; /* matches Git */
1911 
1912 	*link_target = NULL;
1913 
1914 	do {
1915 		err = resolve_symlink(&next_target,
1916 		    *link_target ? *link_target : path, commit_id, repo);
1917 		if (err)
1918 			break;
1919 		if (next_target) {
1920 			free(*link_target);
1921 			if (--max_recursion == 0) {
1922 				err = got_error_path(path, GOT_ERR_RECURSION);
1923 				*link_target = NULL;
1924 				break;
1925 			}
1926 			*link_target = next_target;
1927 		}
1928 	} while (next_target);
1929 
1930 	return err;
1931 }
1932 
1933 const struct got_error *
1934 got_traverse_packed_commits(struct got_object_id_queue *traversed_commits,
1935     struct got_object_id *commit_id, const char *path,
1936     struct got_repository *repo)
1937 {
1938 	const struct got_error *err = NULL;
1939 	struct got_pack *pack = NULL;
1940 	struct got_packidx *packidx = NULL;
1941 	char *path_packfile = NULL;
1942 	struct got_commit_object *changed_commit = NULL;
1943 	struct got_object_id *changed_commit_id = NULL;
1944 	int idx;
1945 
1946 	err = got_repo_search_packidx(&packidx, &idx, repo, commit_id);
1947 	if (err) {
1948 		if (err->code != GOT_ERR_NO_OBJ)
1949 			return err;
1950 		return NULL;
1951 	}
1952 
1953 	err = get_packfile_path(&path_packfile, packidx);
1954 	if (err)
1955 		return err;
1956 
1957 	pack = got_repo_get_cached_pack(repo, path_packfile);
1958 	if (pack == NULL) {
1959 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
1960 		if (err)
1961 			goto done;
1962 	}
1963 
1964 	if (pack->privsep_child == NULL) {
1965 		err = start_pack_privsep_child(pack, packidx);
1966 		if (err)
1967 			goto done;
1968 	}
1969 
1970 	err = got_privsep_send_commit_traversal_request(
1971 	    pack->privsep_child->ibuf, commit_id, idx, path);
1972 	if (err)
1973 		goto done;
1974 
1975 	err = got_privsep_recv_traversed_commits(&changed_commit,
1976 	    &changed_commit_id, traversed_commits, pack->privsep_child->ibuf);
1977 	if (err)
1978 		goto done;
1979 
1980 	if (changed_commit) {
1981 		/*
1982 		 * Cache the commit in which the path was changed.
1983 		 * This commit might be opened again soon.
1984 		 */
1985 		changed_commit->refcnt++;
1986 		err = got_repo_cache_commit(repo, changed_commit_id,
1987 		    changed_commit);
1988 		got_object_commit_close(changed_commit);
1989 	}
1990 done:
1991 	free(path_packfile);
1992 	free(changed_commit_id);
1993 	return err;
1994 }