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Date:: Fri Oct 15 09:24:56 2021 UTC
Message:: raw object blocksize and read buffer were unused; remove them
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/stat.h>
19 #include <sys/queue.h>
20 #include <sys/tree.h>
21 #include <sys/uio.h>
22 #include <sys/socket.h>
23 #include <sys/wait.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 <unistd.h>
34 #include <zlib.h>
35 #include <ctype.h>
36 #include <libgen.h>
37 #include <limits.h>
38 #include <imsg.h>
39 #include <time.h>
40 
41 #include "got_error.h"
42 #include "got_object.h"
43 #include "got_repository.h"
44 #include "got_opentemp.h"
45 #include "got_path.h"
46 
47 #include "got_lib_sha1.h"
48 #include "got_lib_delta.h"
49 #include "got_lib_inflate.h"
50 #include "got_lib_object.h"
51 #include "got_lib_privsep.h"
52 #include "got_lib_object_idcache.h"
53 #include "got_lib_object_cache.h"
54 #include "got_lib_object_parse.h"
55 #include "got_lib_pack.h"
56 #include "got_lib_repository.h"
57 
58 #ifndef MIN
59 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
60 #endif
61 
62 struct got_object_id *
63 got_object_get_id(struct got_object *obj)
64 {
65 	return &obj->id;
66 }
67 
68 const struct got_error *
69 got_object_get_id_str(char **outbuf, struct got_object *obj)
70 {
71 	return got_object_id_str(outbuf, &obj->id);
72 }
73 
74 const struct got_error *
75 got_object_get_type(int *type, struct got_repository *repo,
76     struct got_object_id *id)
77 {
78 	const struct got_error *err = NULL;
79 	struct got_object *obj;
80 
81 	err = got_object_open(&obj, repo, id);
82 	if (err)
83 		return err;
84 
85 	switch (obj->type) {
86 	case GOT_OBJ_TYPE_COMMIT:
87 	case GOT_OBJ_TYPE_TREE:
88 	case GOT_OBJ_TYPE_BLOB:
89 	case GOT_OBJ_TYPE_TAG:
90 		*type = obj->type;
91 		break;
92 	default:
93 		err = got_error(GOT_ERR_OBJ_TYPE);
94 		break;
95 	}
96 
97 	got_object_close(obj);
98 	return err;
99 }
100 
101 const struct got_error *
102 got_object_get_path(char **path, struct got_object_id *id,
103     struct got_repository *repo)
104 {
105 	const struct got_error *err = NULL;
106 	char *hex = NULL;
107 	char *path_objects;
108 
109 	*path = NULL;
110 
111 	path_objects = got_repo_get_path_objects(repo);
112 	if (path_objects == NULL)
113 		return got_error_from_errno("got_repo_get_path_objects");
114 
115 	err = got_object_id_str(&hex, id);
116 	if (err)
117 		goto done;
118 
119 	if (asprintf(path, "%s/%.2x/%s", path_objects,
120 	    id->sha1[0], hex + 2) == -1)
121 		err = got_error_from_errno("asprintf");
122 
123 done:
124 	free(hex);
125 	free(path_objects);
126 	return err;
127 }
128 
129 const struct got_error *
130 got_object_open_loose_fd(int *fd, struct got_object_id *id,
131     struct got_repository *repo)
132 {
133 	const struct got_error *err = NULL;
134 	char *path;
135 
136 	err = got_object_get_path(&path, id, repo);
137 	if (err)
138 		return err;
139 	*fd = open(path, O_RDONLY | O_NOFOLLOW);
140 	if (*fd == -1) {
141 		err = got_error_from_errno2("open", path);
142 		goto done;
143 	}
144 done:
145 	free(path);
146 	return err;
147 }
148 
149 static const struct got_error *
150 request_packed_object(struct got_object **obj, struct got_pack *pack, int idx,
151     struct got_object_id *id)
152 {
153 	const struct got_error *err = NULL;
154 	struct imsgbuf *ibuf = pack->privsep_child->ibuf;
155 
156 	err = got_privsep_send_packed_obj_req(ibuf, idx, id);
157 	if (err)
158 		return err;
159 
160 	err = got_privsep_recv_obj(obj, ibuf);
161 	if (err)
162 		return err;
163 
164 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
165 
166 	return NULL;
167 }
168 
169 static const struct got_error *
170 request_packed_object_raw(uint8_t **outbuf, off_t *size, size_t *hdrlen,
171     int outfd, struct got_pack *pack, int idx, struct got_object_id *id)
172 {
173 	const struct got_error *err = NULL;
174 	struct imsgbuf *ibuf = pack->privsep_child->ibuf;
175 	int outfd_child;
176 	int basefd, accumfd; /* temporary files for delta application */
177 
178 	basefd = got_opentempfd();
179 	if (basefd == -1)
180 		return got_error_from_errno("got_opentempfd");
181 
182 	accumfd = got_opentempfd();
183 	if (accumfd == -1) {
184 		close(basefd);
185 		return got_error_from_errno("got_opentempfd");
186 	}
187 
188 	outfd_child = dup(outfd);
189 	if (outfd_child == -1) {
190 		err = got_error_from_errno("dup");
191 		close(basefd);
192 		close(accumfd);
193 		return err;
194 	}
195 
196 	err = got_privsep_send_packed_raw_obj_req(ibuf, idx, id);
197 	if (err) {
198 		close(basefd);
199 		close(accumfd);
200 		close(outfd_child);
201 		return err;
202 	}
203 
204 	err = got_privsep_send_raw_obj_outfd(ibuf, outfd_child);
205 	if (err) {
206 		close(basefd);
207 		close(accumfd);
208 		return err;
209 	}
210 
211 
212 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
213 	    basefd);
214 	if (err) {
215 		close(accumfd);
216 		return err;
217 	}
218 
219 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
220 	    accumfd);
221 	if (err)
222 		return err;
223 
224 	err = got_privsep_recv_raw_obj(outbuf, size, hdrlen, ibuf);
225 	if (err)
226 		return err;
227 
228 	return NULL;
229 }
230 
231 static void
232 set_max_datasize(void)
233 {
234 	struct rlimit rl;
235 
236 	if (getrlimit(RLIMIT_DATA, &rl) != 0)
237 		return;
238 
239 	rl.rlim_cur = rl.rlim_max;
240 	setrlimit(RLIMIT_DATA, &rl);
241 }
242 
243 static const struct got_error *
244 start_pack_privsep_child(struct got_pack *pack, struct got_packidx *packidx)
245 {
246 	const struct got_error *err = NULL;
247 	int imsg_fds[2];
248 	pid_t pid;
249 	struct imsgbuf *ibuf;
250 
251 	ibuf = calloc(1, sizeof(*ibuf));
252 	if (ibuf == NULL)
253 		return got_error_from_errno("calloc");
254 
255 	pack->privsep_child = calloc(1, sizeof(*pack->privsep_child));
256 	if (pack->privsep_child == NULL) {
257 		err = got_error_from_errno("calloc");
258 		free(ibuf);
259 		return err;
260 	}
261 
262 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
263 		err = got_error_from_errno("socketpair");
264 		goto done;
265 	}
266 
267 	pid = fork();
268 	if (pid == -1) {
269 		err = got_error_from_errno("fork");
270 		goto done;
271 	} else if (pid == 0) {
272 		set_max_datasize();
273 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PACK,
274 		    pack->path_packfile);
275 		/* not reached */
276 	}
277 
278 	if (close(imsg_fds[1]) == -1)
279 		return got_error_from_errno("close");
280 	pack->privsep_child->imsg_fd = imsg_fds[0];
281 	pack->privsep_child->pid = pid;
282 	imsg_init(ibuf, imsg_fds[0]);
283 	pack->privsep_child->ibuf = ibuf;
284 
285 	err = got_privsep_init_pack_child(ibuf, pack, packidx);
286 	if (err) {
287 		const struct got_error *child_err;
288 		err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
289 		child_err = got_privsep_wait_for_child(
290 		    pack->privsep_child->pid);
291 		if (child_err && err == NULL)
292 			err = child_err;
293 	}
294 done:
295 	if (err) {
296 		free(ibuf);
297 		free(pack->privsep_child);
298 		pack->privsep_child = NULL;
299 	}
300 	return err;
301 }
302 
303 static const struct got_error *
304 read_packed_object_privsep(struct got_object **obj,
305     struct got_repository *repo, struct got_pack *pack,
306     struct got_packidx *packidx, int idx, struct got_object_id *id)
307 {
308 	const struct got_error *err = NULL;
309 
310 	if (pack->privsep_child == NULL) {
311 		err = start_pack_privsep_child(pack, packidx);
312 		if (err)
313 			return err;
314 	}
315 
316 	return request_packed_object(obj, pack, idx, id);
317 }
318 
319 static const struct got_error *
320 read_packed_object_raw_privsep(uint8_t **outbuf, off_t *size, size_t *hdrlen,
321     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
322     struct got_object_id *id)
323 {
324 	const struct got_error *err = NULL;
325 
326 	if (pack->privsep_child == NULL) {
327 		err = start_pack_privsep_child(pack, packidx);
328 		if (err)
329 			return err;
330 	}
331 
332 	return request_packed_object_raw(outbuf, size, hdrlen, outfd, pack,
333 	    idx, id);
334 }
335 
336 const struct got_error *
337 got_object_open_packed(struct got_object **obj, struct got_object_id *id,
338     struct got_repository *repo)
339 {
340 	const struct got_error *err = NULL;
341 	struct got_pack *pack = NULL;
342 	struct got_packidx *packidx = NULL;
343 	int idx;
344 	char *path_packfile;
345 
346 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
347 	if (err)
348 		return err;
349 
350 	err = got_packidx_get_packfile_path(&path_packfile,
351 	    packidx->path_packidx);
352 	if (err)
353 		return err;
354 
355 	pack = got_repo_get_cached_pack(repo, path_packfile);
356 	if (pack == NULL) {
357 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
358 		if (err)
359 			goto done;
360 	}
361 
362 	err = read_packed_object_privsep(obj, repo, pack, packidx, idx, id);
363 	if (err)
364 		goto done;
365 done:
366 	free(path_packfile);
367 	return err;
368 }
369 
370 static const struct got_error *
371 request_object(struct got_object **obj, struct got_object_id *id,
372     struct got_repository *repo, int fd)
373 {
374 	const struct got_error *err = NULL;
375 	struct imsgbuf *ibuf;
376 
377 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf;
378 
379 	err = got_privsep_send_obj_req(ibuf, fd, id);
380 	if (err)
381 		return err;
382 
383 	return got_privsep_recv_obj(obj, ibuf);
384 }
385 
386 static const struct got_error *
387 request_raw_object(uint8_t **outbuf, off_t *size, size_t *hdrlen, int outfd,
388     struct got_object_id *id, struct got_repository *repo, int infd)
389 {
390 	const struct got_error *err = NULL;
391 	struct imsgbuf *ibuf;
392 	int outfd_child;
393 
394 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf;
395 
396 	outfd_child = dup(outfd);
397 	if (outfd_child == -1)
398 		return got_error_from_errno("dup");
399 
400 	err = got_privsep_send_raw_obj_req(ibuf, infd, id);
401 	if (err)
402 		return err;
403 
404 	err = got_privsep_send_raw_obj_outfd(ibuf, outfd_child);
405 	if (err)
406 		return err;
407 
408 	return got_privsep_recv_raw_obj(outbuf, size, hdrlen, ibuf);
409 }
410 
411 static const struct got_error *
412 start_read_object_child(struct got_repository *repo)
413 {
414 	const struct got_error *err = NULL;
415 	int imsg_fds[2];
416 	pid_t pid;
417 	struct imsgbuf *ibuf;
418 
419 	ibuf = calloc(1, sizeof(*ibuf));
420 	if (ibuf == NULL)
421 		return got_error_from_errno("calloc");
422 
423 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
424 		err = got_error_from_errno("socketpair");
425 		free(ibuf);
426 		return err;
427 	}
428 
429 	pid = fork();
430 	if (pid == -1) {
431 		err = got_error_from_errno("fork");
432 		free(ibuf);
433 		return err;
434 	}
435 	else if (pid == 0) {
436 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_OBJECT,
437 		    repo->path);
438 		/* not reached */
439 	}
440 
441 	if (close(imsg_fds[1]) == -1) {
442 		err = got_error_from_errno("close");
443 		free(ibuf);
444 		return err;
445 	}
446 
447 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd =
448 	    imsg_fds[0];
449 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].pid = pid;
450 	imsg_init(ibuf, imsg_fds[0]);
451 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf = ibuf;
452 
453 	return NULL;
454 }
455 
456 const struct got_error *
457 got_object_read_header_privsep(struct got_object **obj,
458     struct got_object_id *id, struct got_repository *repo, int obj_fd)
459 {
460 	const struct got_error *err;
461 
462 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd != -1)
463 		return request_object(obj, id, repo, obj_fd);
464 
465 	err = start_read_object_child(repo);
466 	if (err) {
467 		close(obj_fd);
468 		return err;
469 	}
470 
471 	return request_object(obj, id, repo, obj_fd);
472 }
473 
474 static const struct got_error *
475 read_object_raw_privsep(uint8_t **outbuf, off_t *size, size_t *hdrlen,
476     int outfd, struct got_object_id *id, struct got_repository *repo,
477     int obj_fd)
478 {
479 	const struct got_error *err;
480 
481 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd != -1)
482 		return request_raw_object(outbuf, size, hdrlen, outfd, id,
483 		    repo, obj_fd);
484 
485 	err = start_read_object_child(repo);
486 	if (err)
487 		return err;
488 
489 	return request_raw_object(outbuf, size, hdrlen, outfd, id, repo,
490 	    obj_fd);
491 }
492 
493 const struct got_error *
494 got_object_open(struct got_object **obj, struct got_repository *repo,
495     struct got_object_id *id)
496 {
497 	const struct got_error *err = NULL;
498 	int fd;
499 
500 	*obj = got_repo_get_cached_object(repo, id);
501 	if (*obj != NULL) {
502 		(*obj)->refcnt++;
503 		return NULL;
504 	}
505 
506 	err = got_object_open_packed(obj, id, repo);
507 	if (err && err->code != GOT_ERR_NO_OBJ)
508 		return err;
509 	if (*obj) {
510 		(*obj)->refcnt++;
511 		return got_repo_cache_object(repo, id, *obj);
512 	}
513 
514 	err = got_object_open_loose_fd(&fd, id, repo);
515 	if (err) {
516 		if (err->code == GOT_ERR_ERRNO && errno == ENOENT)
517 			err = got_error_no_obj(id);
518 		return err;
519 	}
520 
521 	err = got_object_read_header_privsep(obj, id, repo, fd);
522 	if (err)
523 		return err;
524 
525 	memcpy((*obj)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
526 
527 	(*obj)->refcnt++;
528 	return got_repo_cache_object(repo, id, *obj);
529 }
530 
531 /* *outfd must be initialized to -1 by caller */
532 const struct got_error *
533 got_object_raw_open(struct got_raw_object **obj, int *outfd,
534     struct got_repository *repo, struct got_object_id *id)
535 {
536 	const struct got_error *err = NULL;
537 	struct got_packidx *packidx = NULL;
538 	int idx;
539 	uint8_t *outbuf = NULL;
540 	off_t size = 0;
541 	size_t hdrlen = 0;
542 	char *path_packfile = NULL;
543 
544 	*obj = got_repo_get_cached_raw_object(repo, id);
545 	if (*obj != NULL) {
546 		(*obj)->refcnt++;
547 		return NULL;
548 	}
549 
550 	if (*outfd == -1) {
551 		*outfd = got_opentempfd();
552 		if (*outfd == -1)
553 			return got_error_from_errno("got_opentempfd");
554 	}
555 
556 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
557 	if (err == NULL) {
558 		struct got_pack *pack = NULL;
559 
560 		err = got_packidx_get_packfile_path(&path_packfile,
561 		    packidx->path_packidx);
562 		if (err)
563 			goto done;
564 
565 		pack = got_repo_get_cached_pack(repo, path_packfile);
566 		if (pack == NULL) {
567 			err = got_repo_cache_pack(&pack, repo, path_packfile,
568 			    packidx);
569 			if (err)
570 				goto done;
571 		}
572 		err = read_packed_object_raw_privsep(&outbuf, &size, &hdrlen,
573 		    *outfd, pack, packidx, idx, id);
574 		if (err)
575 			goto done;
576 	} else if (err->code == GOT_ERR_NO_OBJ) {
577 		int fd;
578 
579 		err = got_object_open_loose_fd(&fd, id, repo);
580 		if (err)
581 			goto done;
582 		err = read_object_raw_privsep(&outbuf, &size, &hdrlen, *outfd,
583 		    id, repo, fd);
584 		if (err)
585 			goto done;
586 	}
587 
588 	*obj = calloc(1, sizeof(**obj));
589 	if (*obj == NULL) {
590 		err = got_error_from_errno("calloc");
591 		goto done;
592 	}
593 
594 	if (outbuf) {
595 		(*obj)->f = fmemopen(outbuf, hdrlen + size, "r");
596 		if ((*obj)->f == NULL) {
597 			err = got_error_from_errno("fdopen");
598 			goto done;
599 		}
600 		(*obj)->data = outbuf;
601 	} else {
602 		struct stat sb;
603 		if (fstat(*outfd, &sb) == -1) {
604 			err = got_error_from_errno("fstat");
605 			goto done;
606 		}
607 
608 		if (sb.st_size != hdrlen + size) {
609 			err = got_error(GOT_ERR_PRIVSEP_LEN);
610 			goto done;
611 		}
612 
613 		(*obj)->f = fdopen(*outfd, "r");
614 		if ((*obj)->f == NULL) {
615 			err = got_error_from_errno("fdopen");
616 			goto done;
617 		}
618 		(*obj)->data = NULL;
619 		*outfd = -1;
620 	}
621 	(*obj)->hdrlen = hdrlen;
622 	(*obj)->size = size;
623 	err = got_repo_cache_raw_object(repo, id, *obj);
624 done:
625 	free(path_packfile);
626 	if (err) {
627 		if (*obj) {
628 			got_object_raw_close(*obj);
629 			*obj = NULL;
630 		}
631 		free(outbuf);
632 	} else
633 		(*obj)->refcnt++;
634 	return err;
635 }
636 
637 const struct got_error *
638 got_object_open_by_id_str(struct got_object **obj, struct got_repository *repo,
639     const char *id_str)
640 {
641 	struct got_object_id id;
642 
643 	if (!got_parse_sha1_digest(id.sha1, id_str))
644 		return got_error_path(id_str, GOT_ERR_BAD_OBJ_ID_STR);
645 
646 	return got_object_open(obj, repo, &id);
647 }
648 
649 const struct got_error *
650 got_object_resolve_id_str(struct got_object_id **id,
651     struct got_repository *repo, const char *id_str)
652 {
653 	const struct got_error *err = NULL;
654 	struct got_object *obj;
655 
656 	err = got_object_open_by_id_str(&obj, repo, id_str);
657 	if (err)
658 		return err;
659 
660 	*id = got_object_id_dup(got_object_get_id(obj));
661 	got_object_close(obj);
662 	if (*id == NULL)
663 		return got_error_from_errno("got_object_id_dup");
664 
665 	return NULL;
666 }
667 
668 static const struct got_error *
669 request_packed_commit(struct got_commit_object **commit, struct got_pack *pack,
670     int pack_idx, struct got_object_id *id)
671 {
672 	const struct got_error *err = NULL;
673 
674 	err = got_privsep_send_commit_req(pack->privsep_child->ibuf, -1, id,
675 	    pack_idx);
676 	if (err)
677 		return err;
678 
679 	err = got_privsep_recv_commit(commit, pack->privsep_child->ibuf);
680 	if (err)
681 		return err;
682 
683 	(*commit)->flags |= GOT_COMMIT_FLAG_PACKED;
684 	return NULL;
685 }
686 
687 static const struct got_error *
688 read_packed_commit_privsep(struct got_commit_object **commit,
689     struct got_pack *pack, struct got_packidx *packidx, int idx,
690     struct got_object_id *id)
691 {
692 	const struct got_error *err = NULL;
693 
694 	if (pack->privsep_child)
695 		return request_packed_commit(commit, pack, idx, id);
696 
697 	err = start_pack_privsep_child(pack, packidx);
698 	if (err)
699 		return err;
700 
701 	return request_packed_commit(commit, pack, idx, id);
702 }
703 
704 static const struct got_error *
705 request_commit(struct got_commit_object **commit, struct got_repository *repo,
706     int fd, struct got_object_id *id)
707 {
708 	const struct got_error *err = NULL;
709 	struct imsgbuf *ibuf;
710 
711 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf;
712 
713 	err = got_privsep_send_commit_req(ibuf, fd, id, -1);
714 	if (err)
715 		return err;
716 
717 	return got_privsep_recv_commit(commit, ibuf);
718 }
719 
720 static const struct got_error *
721 read_commit_privsep(struct got_commit_object **commit, int obj_fd,
722     struct got_object_id *id, struct got_repository *repo)
723 {
724 	const struct got_error *err;
725 	int imsg_fds[2];
726 	pid_t pid;
727 	struct imsgbuf *ibuf;
728 
729 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd != -1)
730 		return request_commit(commit, repo, obj_fd, id);
731 
732 	ibuf = calloc(1, sizeof(*ibuf));
733 	if (ibuf == NULL)
734 		return got_error_from_errno("calloc");
735 
736 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
737 		err = got_error_from_errno("socketpair");
738 		free(ibuf);
739 		return err;
740 	}
741 
742 	pid = fork();
743 	if (pid == -1) {
744 		err = got_error_from_errno("fork");
745 		free(ibuf);
746 		return err;
747 	}
748 	else if (pid == 0) {
749 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_COMMIT,
750 		    repo->path);
751 		/* not reached */
752 	}
753 
754 	if (close(imsg_fds[1]) == -1) {
755 		err = got_error_from_errno("close");
756 		free(ibuf);
757 		return err;
758 	}
759 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd =
760 	    imsg_fds[0];
761 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].pid = pid;
762 	imsg_init(ibuf, imsg_fds[0]);
763 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf = ibuf;
764 
765 	return request_commit(commit, repo, obj_fd, id);
766 }
767 
768 
769 static const struct got_error *
770 open_commit(struct got_commit_object **commit,
771     struct got_repository *repo, struct got_object_id *id, int check_cache)
772 {
773 	const struct got_error *err = NULL;
774 	struct got_packidx *packidx = NULL;
775 	int idx;
776 	char *path_packfile = NULL;
777 
778 	if (check_cache) {
779 		*commit = got_repo_get_cached_commit(repo, id);
780 		if (*commit != NULL) {
781 			(*commit)->refcnt++;
782 			return NULL;
783 		}
784 	} else
785 		*commit = NULL;
786 
787 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
788 	if (err == NULL) {
789 		struct got_pack *pack = NULL;
790 
791 		err = got_packidx_get_packfile_path(&path_packfile,
792 		    packidx->path_packidx);
793 		if (err)
794 			return err;
795 
796 		pack = got_repo_get_cached_pack(repo, path_packfile);
797 		if (pack == NULL) {
798 			err = got_repo_cache_pack(&pack, repo, path_packfile,
799 			    packidx);
800 			if (err)
801 				goto done;
802 		}
803 		err = read_packed_commit_privsep(commit, pack,
804 		    packidx, idx, id);
805 	} else if (err->code == GOT_ERR_NO_OBJ) {
806 		int fd;
807 
808 		err = got_object_open_loose_fd(&fd, id, repo);
809 		if (err)
810 			return err;
811 		err = read_commit_privsep(commit, fd, id, repo);
812 	}
813 
814 	if (err == NULL) {
815 		(*commit)->refcnt++;
816 		err = got_repo_cache_commit(repo, id, *commit);
817 	}
818 done:
819 	free(path_packfile);
820 	return err;
821 }
822 
823 const struct got_error *
824 got_object_open_as_commit(struct got_commit_object **commit,
825     struct got_repository *repo, struct got_object_id *id)
826 {
827 	*commit = got_repo_get_cached_commit(repo, id);
828 	if (*commit != NULL) {
829 		(*commit)->refcnt++;
830 		return NULL;
831 	}
832 
833 	return open_commit(commit, repo, id, 0);
834 }
835 
836 const struct got_error *
837 got_object_commit_open(struct got_commit_object **commit,
838     struct got_repository *repo, struct got_object *obj)
839 {
840 	return open_commit(commit, repo, got_object_get_id(obj), 1);
841 }
842 
843 const struct got_error *
844 got_object_qid_alloc(struct got_object_qid **qid, struct got_object_id *id)
845 {
846 	const struct got_error *err = NULL;
847 
848 	*qid = calloc(1, sizeof(**qid));
849 	if (*qid == NULL)
850 		return got_error_from_errno("calloc");
851 
852 	(*qid)->id = got_object_id_dup(id);
853 	if ((*qid)->id == NULL) {
854 		err = got_error_from_errno("got_object_id_dup");
855 		got_object_qid_free(*qid);
856 		*qid = NULL;
857 		return err;
858 	}
859 
860 	return NULL;
861 }
862 
863 const struct got_error *
864 got_object_id_queue_copy(const struct got_object_id_queue *src,
865     struct got_object_id_queue *dest)
866 {
867 	const struct got_error *err;
868 	struct got_object_qid *qid;
869 
870 	STAILQ_FOREACH(qid, src, entry) {
871 		struct got_object_qid *new;
872 		/*
873 		 * Deep-copy the object ID only. Let the caller deal
874 		 * with setting up the new->data pointer if needed.
875 		 */
876 		err = got_object_qid_alloc(&new, qid->id); 
877 		if (err) {
878 			got_object_id_queue_free(dest);
879 			return err;
880 		}
881 		STAILQ_INSERT_TAIL(dest, new, entry);
882 	}
883 
884 	return NULL;
885 }
886 
887 static const struct got_error *
888 request_packed_tree(struct got_tree_object **tree, struct got_pack *pack,
889     int pack_idx, struct got_object_id *id)
890 {
891 	const struct got_error *err = NULL;
892 
893 	err = got_privsep_send_tree_req(pack->privsep_child->ibuf, -1, id,
894 	    pack_idx);
895 	if (err)
896 		return err;
897 
898 	return got_privsep_recv_tree(tree, pack->privsep_child->ibuf);
899 }
900 
901 static const struct got_error *
902 read_packed_tree_privsep(struct got_tree_object **tree,
903     struct got_pack *pack, struct got_packidx *packidx, int idx,
904     struct got_object_id *id)
905 {
906 	const struct got_error *err = NULL;
907 
908 	if (pack->privsep_child)
909 		return request_packed_tree(tree, pack, idx, id);
910 
911 	err = start_pack_privsep_child(pack, packidx);
912 	if (err)
913 		return err;
914 
915 	return request_packed_tree(tree, pack, idx, id);
916 }
917 
918 static const struct got_error *
919 request_tree(struct got_tree_object **tree, struct got_repository *repo,
920     int fd, struct got_object_id *id)
921 {
922 	const struct got_error *err = NULL;
923 	struct imsgbuf *ibuf;
924 
925 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf;
926 
927 	err = got_privsep_send_tree_req(ibuf, fd, id, -1);
928 	if (err)
929 		return err;
930 
931 	return got_privsep_recv_tree(tree, ibuf);
932 }
933 
934 const struct got_error *
935 read_tree_privsep(struct got_tree_object **tree, int obj_fd,
936     struct got_object_id *id, struct got_repository *repo)
937 {
938 	const struct got_error *err;
939 	int imsg_fds[2];
940 	pid_t pid;
941 	struct imsgbuf *ibuf;
942 
943 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd != -1)
944 		return request_tree(tree, repo, obj_fd, id);
945 
946 	ibuf = calloc(1, sizeof(*ibuf));
947 	if (ibuf == NULL)
948 		return got_error_from_errno("calloc");
949 
950 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
951 		err = got_error_from_errno("socketpair");
952 		free(ibuf);
953 		return err;
954 	}
955 
956 	pid = fork();
957 	if (pid == -1) {
958 		err = got_error_from_errno("fork");
959 		free(ibuf);
960 		return err;
961 	}
962 	else if (pid == 0) {
963 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TREE,
964 		    repo->path);
965 		/* not reached */
966 	}
967 
968 	if (close(imsg_fds[1]) == -1) {
969 		err = got_error_from_errno("close");
970 		free(ibuf);
971 		return err;
972 	}
973 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd =
974 	    imsg_fds[0];
975 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].pid = pid;
976 	imsg_init(ibuf, imsg_fds[0]);
977 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf = ibuf;
978 
979 
980 	return request_tree(tree, repo, obj_fd, id);
981 }
982 
983 static const struct got_error *
984 open_tree(struct got_tree_object **tree, struct got_repository *repo,
985     struct got_object_id *id, int check_cache)
986 {
987 	const struct got_error *err = NULL;
988 	struct got_packidx *packidx = NULL;
989 	int idx;
990 	char *path_packfile = NULL;
991 
992 	if (check_cache) {
993 		*tree = got_repo_get_cached_tree(repo, id);
994 		if (*tree != NULL) {
995 			(*tree)->refcnt++;
996 			return NULL;
997 		}
998 	} else
999 		*tree = NULL;
1000 
1001 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1002 	if (err == NULL) {
1003 		struct got_pack *pack = NULL;
1004 
1005 		err = got_packidx_get_packfile_path(&path_packfile,
1006 		    packidx->path_packidx);
1007 		if (err)
1008 			return err;
1009 
1010 		pack = got_repo_get_cached_pack(repo, path_packfile);
1011 		if (pack == NULL) {
1012 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1013 			    packidx);
1014 			if (err)
1015 				goto done;
1016 		}
1017 		err = read_packed_tree_privsep(tree, pack,
1018 		    packidx, idx, id);
1019 	} else if (err->code == GOT_ERR_NO_OBJ) {
1020 		int fd;
1021 
1022 		err = got_object_open_loose_fd(&fd, id, repo);
1023 		if (err)
1024 			return err;
1025 		err = read_tree_privsep(tree, fd, id, repo);
1026 	}
1027 
1028 	if (err == NULL) {
1029 		(*tree)->refcnt++;
1030 		err = got_repo_cache_tree(repo, id, *tree);
1031 	}
1032 done:
1033 	free(path_packfile);
1034 	return err;
1035 }
1036 
1037 const struct got_error *
1038 got_object_open_as_tree(struct got_tree_object **tree,
1039     struct got_repository *repo, struct got_object_id *id)
1040 {
1041 	*tree = got_repo_get_cached_tree(repo, id);
1042 	if (*tree != NULL) {
1043 		(*tree)->refcnt++;
1044 		return NULL;
1045 	}
1046 
1047 	return open_tree(tree, repo, id, 0);
1048 }
1049 
1050 const struct got_error *
1051 got_object_tree_open(struct got_tree_object **tree,
1052     struct got_repository *repo, struct got_object *obj)
1053 {
1054 	return open_tree(tree, repo, got_object_get_id(obj), 1);
1055 }
1056 
1057 int
1058 got_object_tree_get_nentries(struct got_tree_object *tree)
1059 {
1060 	return tree->nentries;
1061 }
1062 
1063 struct got_tree_entry *
1064 got_object_tree_get_first_entry(struct got_tree_object *tree)
1065 {
1066 	return got_object_tree_get_entry(tree, 0);
1067 }
1068 
1069 struct got_tree_entry *
1070 got_object_tree_get_last_entry(struct got_tree_object *tree)
1071 {
1072 	return got_object_tree_get_entry(tree, tree->nentries - 1);
1073 }
1074 
1075 struct got_tree_entry *
1076 got_object_tree_get_entry(struct got_tree_object *tree, int i)
1077 {
1078 	if (i < 0 || i >= tree->nentries)
1079 		return NULL;
1080 	return &tree->entries[i];
1081 }
1082 
1083 mode_t
1084 got_tree_entry_get_mode(struct got_tree_entry *te)
1085 {
1086 	return te->mode;
1087 }
1088 
1089 const char *
1090 got_tree_entry_get_name(struct got_tree_entry *te)
1091 {
1092 	return &te->name[0];
1093 }
1094 
1095 struct got_object_id *
1096 got_tree_entry_get_id(struct got_tree_entry *te)
1097 {
1098 	return &te->id;
1099 }
1100 
1101 const struct got_error *
1102 got_object_blob_read_to_str(char **s, struct got_blob_object *blob)
1103 {
1104 	const struct got_error *err = NULL;
1105 	size_t len, totlen, hdrlen, offset;
1106 
1107 	*s = NULL;
1108 
1109 	hdrlen = got_object_blob_get_hdrlen(blob);
1110 	totlen = 0;
1111 	offset = 0;
1112 	do {
1113 		char *p;
1114 
1115 		err = got_object_blob_read_block(&len, blob);
1116 		if (err)
1117 			return err;
1118 
1119 		if (len == 0)
1120 			break;
1121 
1122 		totlen += len - hdrlen;
1123 		p = realloc(*s, totlen + 1);
1124 		if (p == NULL) {
1125 			err = got_error_from_errno("realloc");
1126 			free(*s);
1127 			*s = NULL;
1128 			return err;
1129 		}
1130 		*s = p;
1131 		/* Skip blob object header first time around. */
1132 		memcpy(*s + offset,
1133 		    got_object_blob_get_read_buf(blob) + hdrlen, len - hdrlen);
1134 		hdrlen = 0;
1135 		offset = totlen;
1136 	} while (len > 0);
1137 
1138 	(*s)[totlen] = '\0';
1139 	return NULL;
1140 }
1141 
1142 const struct got_error *
1143 got_tree_entry_get_symlink_target(char **link_target, struct got_tree_entry *te,
1144     struct got_repository *repo)
1145 {
1146 	const struct got_error *err = NULL;
1147 	struct got_blob_object *blob = NULL;
1148 
1149 	*link_target = NULL;
1150 
1151 	if (!got_object_tree_entry_is_symlink(te))
1152 		return got_error(GOT_ERR_TREE_ENTRY_TYPE);
1153 
1154 	err = got_object_open_as_blob(&blob, repo,
1155 	    got_tree_entry_get_id(te), PATH_MAX);
1156 	if (err)
1157 		return err;
1158 
1159 	err = got_object_blob_read_to_str(link_target, blob);
1160 	got_object_blob_close(blob);
1161 	if (err) {
1162 		free(*link_target);
1163 		*link_target = NULL;
1164 	}
1165 	return err;
1166 }
1167 
1168 int
1169 got_tree_entry_get_index(struct got_tree_entry *te)
1170 {
1171 	return te->idx;
1172 }
1173 
1174 struct got_tree_entry *
1175 got_tree_entry_get_next(struct got_tree_object *tree,
1176     struct got_tree_entry *te)
1177 {
1178 	return got_object_tree_get_entry(tree, te->idx + 1);
1179 }
1180 
1181 struct got_tree_entry *
1182 got_tree_entry_get_prev(struct got_tree_object *tree,
1183     struct got_tree_entry *te)
1184 {
1185 	return got_object_tree_get_entry(tree, te->idx - 1);
1186 }
1187 
1188 static const struct got_error *
1189 request_packed_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
1190     struct got_pack *pack, struct got_packidx *packidx, int idx,
1191     struct got_object_id *id)
1192 {
1193 	const struct got_error *err = NULL;
1194 	int outfd_child;
1195 	int basefd, accumfd; /* temporary files for delta application */
1196 
1197 	basefd = got_opentempfd();
1198 	if (basefd == -1)
1199 		return got_error_from_errno("got_opentempfd");
1200 	accumfd = got_opentempfd();
1201 	if (accumfd == -1)
1202 		return got_error_from_errno("got_opentempfd");
1203 
1204 	outfd_child = dup(outfd);
1205 	if (outfd_child == -1)
1206 		return got_error_from_errno("dup");
1207 
1208 	err = got_privsep_send_blob_req(pack->privsep_child->ibuf, -1, id, idx);
1209 	if (err)
1210 		return err;
1211 
1212 	err = got_privsep_send_blob_outfd(pack->privsep_child->ibuf,
1213 	    outfd_child);
1214 	if (err) {
1215 		close(basefd);
1216 		close(accumfd);
1217 		return err;
1218 	}
1219 
1220 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
1221 	    basefd);
1222 	if (err) {
1223 		close(accumfd);
1224 		return err;
1225 	}
1226 
1227 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
1228 	    accumfd);
1229 	if (err)
1230 		return err;
1231 
1232 	err = got_privsep_recv_blob(outbuf, size, hdrlen,
1233 	    pack->privsep_child->ibuf);
1234 	if (err)
1235 		return err;
1236 
1237 	if (lseek(outfd, SEEK_SET, 0) == -1)
1238 		err = got_error_from_errno("lseek");
1239 
1240 	return err;
1241 }
1242 
1243 static const struct got_error *
1244 read_packed_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1245     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
1246     struct got_object_id *id)
1247 {
1248 	const struct got_error *err = NULL;
1249 
1250 	if (pack->privsep_child == NULL) {
1251 		err = start_pack_privsep_child(pack, packidx);
1252 		if (err)
1253 			return err;
1254 	}
1255 
1256 	return request_packed_blob(outbuf, size, hdrlen, outfd, pack, packidx,
1257 	    idx, id);
1258 }
1259 
1260 static const struct got_error *
1261 request_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
1262     int infd, struct got_object_id *id, struct imsgbuf *ibuf)
1263 {
1264 	const struct got_error *err = NULL;
1265 	int outfd_child;
1266 
1267 	outfd_child = dup(outfd);
1268 	if (outfd_child == -1)
1269 		return got_error_from_errno("dup");
1270 
1271 	err = got_privsep_send_blob_req(ibuf, infd, id, -1);
1272 	if (err)
1273 		return err;
1274 
1275 	err = got_privsep_send_blob_outfd(ibuf, outfd_child);
1276 	if (err)
1277 		return err;
1278 
1279 	err = got_privsep_recv_blob(outbuf, size, hdrlen, ibuf);
1280 	if (err)
1281 		return err;
1282 
1283 	if (lseek(outfd, SEEK_SET, 0) == -1)
1284 		return got_error_from_errno("lseek");
1285 
1286 	return err;
1287 }
1288 
1289 static const struct got_error *
1290 read_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1291     int outfd, int infd, struct got_object_id *id, struct got_repository *repo)
1292 {
1293 	const struct got_error *err;
1294 	int imsg_fds[2];
1295 	pid_t pid;
1296 	struct imsgbuf *ibuf;
1297 
1298 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd != -1) {
1299 		ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf;
1300 		return request_blob(outbuf, size, hdrlen, outfd, infd, id,
1301 		    ibuf);
1302 	}
1303 
1304 	ibuf = calloc(1, sizeof(*ibuf));
1305 	if (ibuf == NULL)
1306 		return got_error_from_errno("calloc");
1307 
1308 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1309 		err = got_error_from_errno("socketpair");
1310 		free(ibuf);
1311 		return err;
1312 	}
1313 
1314 	pid = fork();
1315 	if (pid == -1) {
1316 		err = got_error_from_errno("fork");
1317 		free(ibuf);
1318 		return err;
1319 	}
1320 	else if (pid == 0) {
1321 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_BLOB,
1322 		    repo->path);
1323 		/* not reached */
1324 	}
1325 
1326 	if (close(imsg_fds[1]) == -1) {
1327 		err = got_error_from_errno("close");
1328 		free(ibuf);
1329 		return err;
1330 	}
1331 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd =
1332 	    imsg_fds[0];
1333 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].pid = pid;
1334 	imsg_init(ibuf, imsg_fds[0]);
1335 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf = ibuf;
1336 
1337 	return request_blob(outbuf, size, hdrlen, outfd, infd, id, ibuf);
1338 }
1339 
1340 static const struct got_error *
1341 open_blob(struct got_blob_object **blob, struct got_repository *repo,
1342     struct got_object_id *id, size_t blocksize)
1343 {
1344 	const struct got_error *err = NULL;
1345 	struct got_packidx *packidx = NULL;
1346 	int idx;
1347 	char *path_packfile = NULL;
1348 	uint8_t *outbuf;
1349 	int outfd;
1350 	size_t size, hdrlen;
1351 	struct stat sb;
1352 
1353 	*blob = calloc(1, sizeof(**blob));
1354 	if (*blob == NULL)
1355 		return got_error_from_errno("calloc");
1356 
1357 	outfd = got_opentempfd();
1358 	if (outfd == -1)
1359 		return got_error_from_errno("got_opentempfd");
1360 
1361 	(*blob)->read_buf = malloc(blocksize);
1362 	if ((*blob)->read_buf == NULL) {
1363 		err = got_error_from_errno("malloc");
1364 		goto done;
1365 	}
1366 
1367 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1368 	if (err == NULL) {
1369 		struct got_pack *pack = NULL;
1370 
1371 		err = got_packidx_get_packfile_path(&path_packfile,
1372 		    packidx->path_packidx);
1373 		if (err)
1374 			goto done;
1375 
1376 		pack = got_repo_get_cached_pack(repo, path_packfile);
1377 		if (pack == NULL) {
1378 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1379 			    packidx);
1380 			if (err)
1381 				goto done;
1382 		}
1383 		err = read_packed_blob_privsep(&outbuf, &size, &hdrlen, outfd,
1384 		    pack, packidx, idx, id);
1385 	} else if (err->code == GOT_ERR_NO_OBJ) {
1386 		int infd;
1387 
1388 		err = got_object_open_loose_fd(&infd, id, repo);
1389 		if (err)
1390 			goto done;
1391 		err = read_blob_privsep(&outbuf, &size, &hdrlen, outfd, infd,
1392 		    id, repo);
1393 	}
1394 	if (err)
1395 		goto done;
1396 
1397 	if (hdrlen > size) {
1398 		err = got_error(GOT_ERR_BAD_OBJ_HDR);
1399 		goto done;
1400 	}
1401 
1402 	if (outbuf) {
1403 		if (close(outfd) == -1 && err == NULL)
1404 			err = got_error_from_errno("close");
1405 		outfd = -1;
1406 		(*blob)->f = fmemopen(outbuf, size, "rb");
1407 		if ((*blob)->f == NULL) {
1408 			err = got_error_from_errno("fmemopen");
1409 			free(outbuf);
1410 			goto done;
1411 		}
1412 		(*blob)->data = outbuf;
1413 	} else {
1414 		if (fstat(outfd, &sb) == -1) {
1415 			err = got_error_from_errno("fstat");
1416 			goto done;
1417 		}
1418 
1419 		if (sb.st_size != size) {
1420 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1421 			goto done;
1422 		}
1423 
1424 		(*blob)->f = fdopen(outfd, "rb");
1425 		if ((*blob)->f == NULL) {
1426 			err = got_error_from_errno("fdopen");
1427 			close(outfd);
1428 			outfd = -1;
1429 			goto done;
1430 		}
1431 	}
1432 
1433 	(*blob)->hdrlen = hdrlen;
1434 	(*blob)->blocksize = blocksize;
1435 	memcpy(&(*blob)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
1436 
1437 done:
1438 	free(path_packfile);
1439 	if (err) {
1440 		if (*blob) {
1441 			got_object_blob_close(*blob);
1442 			*blob = NULL;
1443 		} else if (outfd != -1)
1444 			close(outfd);
1445 	}
1446 	return err;
1447 }
1448 
1449 const struct got_error *
1450 got_object_open_as_blob(struct got_blob_object **blob,
1451     struct got_repository *repo, struct got_object_id *id,
1452     size_t blocksize)
1453 {
1454 	return open_blob(blob, repo, id, blocksize);
1455 }
1456 
1457 const struct got_error *
1458 got_object_blob_open(struct got_blob_object **blob,
1459     struct got_repository *repo, struct got_object *obj, size_t blocksize)
1460 {
1461 	return open_blob(blob, repo, got_object_get_id(obj), blocksize);
1462 }
1463 
1464 const struct got_error *
1465 got_object_blob_close(struct got_blob_object *blob)
1466 {
1467 	const struct got_error *err = NULL;
1468 	free(blob->read_buf);
1469 	if (blob->f && fclose(blob->f) == EOF)
1470 		err = got_error_from_errno("fclose");
1471 	free(blob->data);
1472 	free(blob);
1473 	return err;
1474 }
1475 
1476 void
1477 got_object_blob_rewind(struct got_blob_object *blob)
1478 {
1479 	if (blob->f)
1480 		rewind(blob->f);
1481 }
1482 
1483 char *
1484 got_object_blob_id_str(struct got_blob_object *blob, char *buf, size_t size)
1485 {
1486 	return got_sha1_digest_to_str(blob->id.sha1, buf, size);
1487 }
1488 
1489 size_t
1490 got_object_blob_get_hdrlen(struct got_blob_object *blob)
1491 {
1492 	return blob->hdrlen;
1493 }
1494 
1495 const uint8_t *
1496 got_object_blob_get_read_buf(struct got_blob_object *blob)
1497 {
1498 	return blob->read_buf;
1499 }
1500 
1501 const struct got_error *
1502 got_object_blob_read_block(size_t *outlenp, struct got_blob_object *blob)
1503 {
1504 	size_t n;
1505 
1506 	n = fread(blob->read_buf, 1, blob->blocksize, blob->f);
1507 	if (n == 0 && ferror(blob->f))
1508 		return got_ferror(blob->f, GOT_ERR_IO);
1509 	*outlenp = n;
1510 	return NULL;
1511 }
1512 
1513 const struct got_error *
1514 got_object_blob_dump_to_file(off_t *filesize, int *nlines,
1515     off_t **line_offsets, FILE *outfile, struct got_blob_object *blob)
1516 {
1517 	const struct got_error *err = NULL;
1518 	size_t n, len, hdrlen;
1519 	const uint8_t *buf;
1520 	int i;
1521 	const int alloc_chunksz = 512;
1522 	size_t nalloc = 0;
1523 	off_t off = 0, total_len = 0;
1524 
1525 	if (line_offsets)
1526 		*line_offsets = NULL;
1527 	if (filesize)
1528 		*filesize = 0;
1529 	if (nlines)
1530 		*nlines = 0;
1531 
1532 	hdrlen = got_object_blob_get_hdrlen(blob);
1533 	do {
1534 		err = got_object_blob_read_block(&len, blob);
1535 		if (err)
1536 			return err;
1537 		if (len == 0)
1538 			break;
1539 		buf = got_object_blob_get_read_buf(blob);
1540 		i = hdrlen;
1541 		if (nlines) {
1542 			if (line_offsets && *line_offsets == NULL) {
1543 				/* Have some data but perhaps no '\n'. */
1544 				*nlines = 1;
1545 				nalloc = alloc_chunksz;
1546 				*line_offsets = calloc(nalloc,
1547 				    sizeof(**line_offsets));
1548 				if (*line_offsets == NULL)
1549 					return got_error_from_errno("calloc");
1550 
1551 				/* Skip forward over end of first line. */
1552 				while (i < len) {
1553 					if (buf[i] == '\n')
1554 						break;
1555 					i++;
1556 				}
1557 			}
1558 			/* Scan '\n' offsets in remaining chunk of data. */
1559 			while (i < len) {
1560 				if (buf[i] != '\n') {
1561 					i++;
1562 					continue;
1563 				}
1564 				(*nlines)++;
1565 				if (line_offsets && nalloc < *nlines) {
1566 					size_t n = *nlines + alloc_chunksz;
1567 					off_t *o = recallocarray(*line_offsets,
1568 					    nalloc, n, sizeof(**line_offsets));
1569 					if (o == NULL) {
1570 						free(*line_offsets);
1571 						*line_offsets = NULL;
1572 						return got_error_from_errno(
1573 						    "recallocarray");
1574 					}
1575 					*line_offsets = o;
1576 					nalloc = n;
1577 				}
1578 				if (line_offsets) {
1579 					off = total_len + i - hdrlen + 1;
1580 					(*line_offsets)[*nlines - 1] = off;
1581 				}
1582 				i++;
1583 			}
1584 		}
1585 		/* Skip blob object header first time around. */
1586 		n = fwrite(buf + hdrlen, 1, len - hdrlen, outfile);
1587 		if (n != len - hdrlen)
1588 			return got_ferror(outfile, GOT_ERR_IO);
1589 		total_len += len - hdrlen;
1590 		hdrlen = 0;
1591 	} while (len != 0);
1592 
1593 	if (fflush(outfile) != 0)
1594 		return got_error_from_errno("fflush");
1595 	rewind(outfile);
1596 
1597 	if (filesize)
1598 		*filesize = total_len;
1599 
1600 	return NULL;
1601 }
1602 
1603 static const struct got_error *
1604 request_packed_tag(struct got_tag_object **tag, struct got_pack *pack,
1605     int pack_idx, struct got_object_id *id)
1606 {
1607 	const struct got_error *err = NULL;
1608 
1609 	err = got_privsep_send_tag_req(pack->privsep_child->ibuf, -1, id,
1610 	    pack_idx);
1611 	if (err)
1612 		return err;
1613 
1614 	return got_privsep_recv_tag(tag, pack->privsep_child->ibuf);
1615 }
1616 
1617 static const struct got_error *
1618 read_packed_tag_privsep(struct got_tag_object **tag,
1619     struct got_pack *pack, struct got_packidx *packidx, int idx,
1620     struct got_object_id *id)
1621 {
1622 	const struct got_error *err = NULL;
1623 
1624 	if (pack->privsep_child)
1625 		return request_packed_tag(tag, pack, idx, id);
1626 
1627 	err = start_pack_privsep_child(pack, packidx);
1628 	if (err)
1629 		return err;
1630 
1631 	return request_packed_tag(tag, pack, idx, id);
1632 }
1633 
1634 static const struct got_error *
1635 request_tag(struct got_tag_object **tag, struct got_repository *repo,
1636     int fd, struct got_object_id *id)
1637 {
1638 	const struct got_error *err = NULL;
1639 	struct imsgbuf *ibuf;
1640 
1641 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf;
1642 
1643 	err = got_privsep_send_tag_req(ibuf, fd, id, -1);
1644 	if (err)
1645 		return err;
1646 
1647 	return got_privsep_recv_tag(tag, ibuf);
1648 }
1649 
1650 static const struct got_error *
1651 read_tag_privsep(struct got_tag_object **tag, int obj_fd,
1652     struct got_object_id *id, struct got_repository *repo)
1653 {
1654 	const struct got_error *err;
1655 	int imsg_fds[2];
1656 	pid_t pid;
1657 	struct imsgbuf *ibuf;
1658 
1659 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd != -1)
1660 		return request_tag(tag, repo, obj_fd, id);
1661 
1662 	ibuf = calloc(1, sizeof(*ibuf));
1663 	if (ibuf == NULL)
1664 		return got_error_from_errno("calloc");
1665 
1666 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1667 		err = got_error_from_errno("socketpair");
1668 		free(ibuf);
1669 		return err;
1670 	}
1671 
1672 	pid = fork();
1673 	if (pid == -1) {
1674 		err = got_error_from_errno("fork");
1675 		free(ibuf);
1676 		return err;
1677 	}
1678 	else if (pid == 0) {
1679 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TAG,
1680 		    repo->path);
1681 		/* not reached */
1682 	}
1683 
1684 	if (close(imsg_fds[1]) == -1) {
1685 		err = got_error_from_errno("close");
1686 		free(ibuf);
1687 		return err;
1688 	}
1689 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd =
1690 	    imsg_fds[0];
1691 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].pid = pid;
1692 	imsg_init(ibuf, imsg_fds[0]);
1693 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf = ibuf;
1694 
1695 	return request_tag(tag, repo, obj_fd, id);
1696 }
1697 
1698 static const struct got_error *
1699 open_tag(struct got_tag_object **tag, struct got_repository *repo,
1700     struct got_object_id *id, int check_cache)
1701 {
1702 	const struct got_error *err = NULL;
1703 	struct got_packidx *packidx = NULL;
1704 	int idx;
1705 	char *path_packfile = NULL;
1706 	struct got_object *obj = NULL;
1707 	int obj_type = GOT_OBJ_TYPE_ANY;
1708 
1709 	if (check_cache) {
1710 		*tag = got_repo_get_cached_tag(repo, id);
1711 		if (*tag != NULL) {
1712 			(*tag)->refcnt++;
1713 			return NULL;
1714 		}
1715 	} else
1716 		*tag = NULL;
1717 
1718 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1719 	if (err == NULL) {
1720 		struct got_pack *pack = NULL;
1721 
1722 		err = got_packidx_get_packfile_path(&path_packfile,
1723 		    packidx->path_packidx);
1724 		if (err)
1725 			return err;
1726 
1727 		pack = got_repo_get_cached_pack(repo, path_packfile);
1728 		if (pack == NULL) {
1729 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1730 			    packidx);
1731 			if (err)
1732 				goto done;
1733 		}
1734 
1735 		/* Beware of "lightweight" tags: Check object type first. */
1736 		err = read_packed_object_privsep(&obj, repo, pack, packidx,
1737 		    idx, id);
1738 		if (err)
1739 			goto done;
1740 		obj_type = obj->type;
1741 		got_object_close(obj);
1742 		if (obj_type != GOT_OBJ_TYPE_TAG) {
1743 			err = got_error(GOT_ERR_OBJ_TYPE);
1744 			goto done;
1745 		}
1746 		err = read_packed_tag_privsep(tag, pack, packidx, idx, id);
1747 	} else if (err->code == GOT_ERR_NO_OBJ) {
1748 		int fd;
1749 
1750 		err = got_object_open_loose_fd(&fd, id, repo);
1751 		if (err)
1752 			return err;
1753 		err = got_object_read_header_privsep(&obj, id, repo, fd);
1754 		if (err)
1755 			return err;
1756 		obj_type = obj->type;
1757 		got_object_close(obj);
1758 		if (obj_type != GOT_OBJ_TYPE_TAG)
1759 			return got_error(GOT_ERR_OBJ_TYPE);
1760 
1761 		err = got_object_open_loose_fd(&fd, id, repo);
1762 		if (err)
1763 			return err;
1764 		err = read_tag_privsep(tag, fd, id, repo);
1765 	}
1766 
1767 	if (err == NULL) {
1768 		(*tag)->refcnt++;
1769 		err = got_repo_cache_tag(repo, id, *tag);
1770 	}
1771 done:
1772 	free(path_packfile);
1773 	return err;
1774 }
1775 
1776 const struct got_error *
1777 got_object_open_as_tag(struct got_tag_object **tag,
1778     struct got_repository *repo, struct got_object_id *id)
1779 {
1780 	*tag = got_repo_get_cached_tag(repo, id);
1781 	if (*tag != NULL) {
1782 		(*tag)->refcnt++;
1783 		return NULL;
1784 	}
1785 
1786 	return open_tag(tag, repo, id, 0);
1787 }
1788 
1789 const struct got_error *
1790 got_object_tag_open(struct got_tag_object **tag,
1791     struct got_repository *repo, struct got_object *obj)
1792 {
1793 	return open_tag(tag, repo, got_object_get_id(obj), 1);
1794 }
1795 
1796 const char *
1797 got_object_tag_get_name(struct got_tag_object *tag)
1798 {
1799 	return tag->tag;
1800 }
1801 
1802 int
1803 got_object_tag_get_object_type(struct got_tag_object *tag)
1804 {
1805 	return tag->obj_type;
1806 }
1807 
1808 struct got_object_id *
1809 got_object_tag_get_object_id(struct got_tag_object *tag)
1810 {
1811 	return &tag->id;
1812 }
1813 
1814 time_t
1815 got_object_tag_get_tagger_time(struct got_tag_object *tag)
1816 {
1817 	return tag->tagger_time;
1818 }
1819 
1820 time_t
1821 got_object_tag_get_tagger_gmtoff(struct got_tag_object *tag)
1822 {
1823 	return tag->tagger_gmtoff;
1824 }
1825 
1826 const char *
1827 got_object_tag_get_tagger(struct got_tag_object *tag)
1828 {
1829 	return tag->tagger;
1830 }
1831 
1832 const char *
1833 got_object_tag_get_message(struct got_tag_object *tag)
1834 {
1835 	return tag->tagmsg;
1836 }
1837 
1838 static struct got_tree_entry *
1839 find_entry_by_name(struct got_tree_object *tree, const char *name, size_t len)
1840 {
1841 	int i;
1842 
1843 	/* Note that tree entries are sorted in strncmp() order. */
1844 	for (i = 0; i < tree->nentries; i++) {
1845 		struct got_tree_entry *te = &tree->entries[i];
1846 		int cmp = strncmp(te->name, name, len);
1847 		if (cmp < 0)
1848 			continue;
1849 		if (cmp > 0)
1850 			break;
1851 		if (te->name[len] == '\0')
1852 			return te;
1853 	}
1854 	return NULL;
1855 }
1856 
1857 struct got_tree_entry *
1858 got_object_tree_find_entry(struct got_tree_object *tree, const char *name)
1859 {
1860 	return find_entry_by_name(tree, name, strlen(name));
1861 }
1862 
1863 const struct got_error *
1864 got_object_tree_find_path(struct got_object_id **id, mode_t *mode,
1865     struct got_repository *repo, struct got_tree_object *tree,
1866     const char *path)
1867 {
1868 	const struct got_error *err = NULL;
1869 	struct got_tree_object *subtree = NULL;
1870 	struct got_tree_entry *te = NULL;
1871 	const char *seg, *s;
1872 	size_t seglen;
1873 
1874 	*id = NULL;
1875 
1876 	s = path;
1877 	while (s[0] == '/')
1878 		s++;
1879 	seg = s;
1880 	seglen = 0;
1881 	subtree = tree;
1882 	while (*s) {
1883 		struct got_tree_object *next_tree;
1884 
1885 		if (*s != '/') {
1886 			s++;
1887 			seglen++;
1888 			if (*s)
1889 				continue;
1890 		}
1891 
1892 		te = find_entry_by_name(subtree, seg, seglen);
1893 		if (te == NULL) {
1894 			err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
1895 			goto done;
1896 		}
1897 
1898 		if (*s == '\0')
1899 			break;
1900 
1901 		seg = s + 1;
1902 		seglen = 0;
1903 		s++;
1904 		if (*s) {
1905 			err = got_object_open_as_tree(&next_tree, repo,
1906 			    &te->id);
1907 			te = NULL;
1908 			if (err)
1909 				goto done;
1910 			if (subtree != tree)
1911 				got_object_tree_close(subtree);
1912 			subtree = next_tree;
1913 		}
1914 	}
1915 
1916 	if (te) {
1917 		*id = got_object_id_dup(&te->id);
1918 		if (*id == NULL)
1919 			return got_error_from_errno("got_object_id_dup");
1920 		if (mode)
1921 			*mode = te->mode;
1922 	} else
1923 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
1924 done:
1925 	if (subtree && subtree != tree)
1926 		got_object_tree_close(subtree);
1927 	return err;
1928 }
1929 const struct got_error *
1930 got_object_id_by_path(struct got_object_id **id, struct got_repository *repo,
1931     struct got_object_id *commit_id, const char *path)
1932 {
1933 	const struct got_error *err = NULL;
1934 	struct got_commit_object *commit = NULL;
1935 	struct got_tree_object *tree = NULL;
1936 
1937 	*id = NULL;
1938 
1939 	err = got_object_open_as_commit(&commit, repo, commit_id);
1940 	if (err)
1941 		goto done;
1942 
1943 	/* Handle opening of root of commit's tree. */
1944 	if (got_path_is_root_dir(path)) {
1945 		*id = got_object_id_dup(commit->tree_id);
1946 		if (*id == NULL)
1947 			err = got_error_from_errno("got_object_id_dup");
1948 	} else {
1949 		err = got_object_open_as_tree(&tree, repo, commit->tree_id);
1950 		if (err)
1951 			goto done;
1952 		err = got_object_tree_find_path(id, NULL, repo, tree, path);
1953 	}
1954 done:
1955 	if (commit)
1956 		got_object_commit_close(commit);
1957 	if (tree)
1958 		got_object_tree_close(tree);
1959 	return err;
1960 }
1961 
1962 /*
1963  * Normalize file mode bits to avoid false positive tree entry differences
1964  * in case tree entries have unexpected mode bits set.
1965  */
1966 static mode_t
1967 normalize_mode_for_comparison(mode_t mode)
1968 {
1969 	/*
1970 	 * For directories, the only relevant bit is the IFDIR bit.
1971 	 * This allows us to detect paths changing from a directory
1972 	 * to a file and vice versa.
1973 	 */
1974 	if (S_ISDIR(mode))
1975 		return mode & S_IFDIR;
1976 
1977 	/*
1978 	 * For symlinks, the only relevant bit is the IFLNK bit.
1979 	 * This allows us to detect paths changing from a symlinks
1980 	 * to a file or directory and vice versa.
1981 	 */
1982 	if (S_ISLNK(mode))
1983 		return mode & S_IFLNK;
1984 
1985 	/* For files, the only change we care about is the executable bit. */
1986 	return mode & S_IXUSR;
1987 }
1988 
1989 const struct got_error *
1990 got_object_tree_path_changed(int *changed,
1991     struct got_tree_object *tree01, struct got_tree_object *tree02,
1992     const char *path, struct got_repository *repo)
1993 {
1994 	const struct got_error *err = NULL;
1995 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
1996 	struct got_tree_entry *te1 = NULL, *te2 = NULL;
1997 	const char *seg, *s;
1998 	size_t seglen;
1999 
2000 	*changed = 0;
2001 
2002 	/* We not do support comparing the root path. */
2003 	if (got_path_is_root_dir(path))
2004 		return got_error_path(path, GOT_ERR_BAD_PATH);
2005 
2006 	tree1 = tree01;
2007 	tree2 = tree02;
2008 	s = path;
2009 	while (*s == '/')
2010 		s++;
2011 	seg = s;
2012 	seglen = 0;
2013 	while (*s) {
2014 		struct got_tree_object *next_tree1, *next_tree2;
2015 		mode_t mode1, mode2;
2016 
2017 		if (*s != '/') {
2018 			s++;
2019 			seglen++;
2020 			if (*s)
2021 				continue;
2022 		}
2023 
2024 		te1 = find_entry_by_name(tree1, seg, seglen);
2025 		if (te1 == NULL) {
2026 			err = got_error(GOT_ERR_NO_OBJ);
2027 			goto done;
2028 		}
2029 
2030 		if (tree2)
2031 			te2 = find_entry_by_name(tree2, seg, seglen);
2032 
2033 		if (te2) {
2034 			mode1 = normalize_mode_for_comparison(te1->mode);
2035 			mode2 = normalize_mode_for_comparison(te2->mode);
2036 			if (mode1 != mode2) {
2037 				*changed = 1;
2038 				goto done;
2039 			}
2040 
2041 			if (got_object_id_cmp(&te1->id, &te2->id) == 0) {
2042 				*changed = 0;
2043 				goto done;
2044 			}
2045 		}
2046 
2047 		if (*s == '\0') { /* final path element */
2048 			*changed = 1;
2049 			goto done;
2050 		}
2051 
2052 		seg = s + 1;
2053 		s++;
2054 		seglen = 0;
2055 		if (*s) {
2056 			err = got_object_open_as_tree(&next_tree1, repo,
2057 			    &te1->id);
2058 			te1 = NULL;
2059 			if (err)
2060 				goto done;
2061 			if (tree1 != tree01)
2062 				got_object_tree_close(tree1);
2063 			tree1 = next_tree1;
2064 
2065 			if (te2) {
2066 				err = got_object_open_as_tree(&next_tree2, repo,
2067 				    &te2->id);
2068 				te2 = NULL;
2069 				if (err)
2070 					goto done;
2071 				if (tree2 != tree02)
2072 					got_object_tree_close(tree2);
2073 				tree2 = next_tree2;
2074 			} else if (tree2) {
2075 				if (tree2 != tree02)
2076 					got_object_tree_close(tree2);
2077 				tree2 = NULL;
2078 			}
2079 		}
2080 	}
2081 done:
2082 	if (tree1 && tree1 != tree01)
2083 		got_object_tree_close(tree1);
2084 	if (tree2 && tree2 != tree02)
2085 		got_object_tree_close(tree2);
2086 	return err;
2087 }
2088 
2089 const struct got_error *
2090 got_object_tree_entry_dup(struct got_tree_entry **new_te,
2091     struct got_tree_entry *te)
2092 {
2093 	const struct got_error *err = NULL;
2094 
2095 	*new_te = calloc(1, sizeof(**new_te));
2096 	if (*new_te == NULL)
2097 		return got_error_from_errno("calloc");
2098 
2099 	(*new_te)->mode = te->mode;
2100 	memcpy((*new_te)->name, te->name, sizeof((*new_te)->name));
2101 	memcpy(&(*new_te)->id, &te->id, sizeof((*new_te)->id));
2102 	return err;
2103 }
2104 
2105 int
2106 got_object_tree_entry_is_submodule(struct got_tree_entry *te)
2107 {
2108 	return (te->mode & S_IFMT) == (S_IFDIR | S_IFLNK);
2109 }
2110 
2111 int
2112 got_object_tree_entry_is_symlink(struct got_tree_entry *te)
2113 {
2114 	/* S_IFDIR check avoids confusing symlinks with submodules. */
2115 	return ((te->mode & (S_IFDIR | S_IFLNK)) == S_IFLNK);
2116 }
2117 
2118 static const struct got_error *
2119 resolve_symlink(char **link_target, const char *path,
2120     struct got_object_id *commit_id, struct got_repository *repo)
2121 {
2122 	const struct got_error *err = NULL;
2123 	char buf[PATH_MAX];
2124 	char *name, *parent_path = NULL;
2125 	struct got_object_id *tree_obj_id = NULL;
2126 	struct got_tree_object *tree = NULL;
2127 	struct got_tree_entry *te = NULL;
2128 
2129 	*link_target = NULL;
2130 
2131 	if (strlcpy(buf, path, sizeof(buf)) >= sizeof(buf))
2132 		return got_error(GOT_ERR_NO_SPACE);
2133 
2134 	name = basename(buf);
2135 	if (name == NULL)
2136 		return got_error_from_errno2("basename", path);
2137 
2138 	err = got_path_dirname(&parent_path, path);
2139 	if (err)
2140 		return err;
2141 
2142 	err = got_object_id_by_path(&tree_obj_id, repo, commit_id,
2143 	    parent_path);
2144 	if (err) {
2145 		if (err->code == GOT_ERR_NO_TREE_ENTRY) {
2146 			/* Display the complete path in error message. */
2147 			err = got_error_path(path, err->code);
2148 		}
2149 		goto done;
2150 	}
2151 
2152 	err = got_object_open_as_tree(&tree, repo, tree_obj_id);
2153 	if (err)
2154 		goto done;
2155 
2156 	te = got_object_tree_find_entry(tree, name);
2157 	if (te == NULL) {
2158 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
2159 		goto done;
2160 	}
2161 
2162 	if (got_object_tree_entry_is_symlink(te)) {
2163 		err = got_tree_entry_get_symlink_target(link_target, te, repo);
2164 		if (err)
2165 			goto done;
2166 		if (!got_path_is_absolute(*link_target)) {
2167 			char *abspath;
2168 			if (asprintf(&abspath, "%s/%s", parent_path,
2169 			    *link_target) == -1) {
2170 				err = got_error_from_errno("asprintf");
2171 				goto done;
2172 			}
2173 			free(*link_target);
2174 			*link_target = malloc(PATH_MAX);
2175 			if (*link_target == NULL) {
2176 				err = got_error_from_errno("malloc");
2177 				goto done;
2178 			}
2179 			err = got_canonpath(abspath, *link_target, PATH_MAX);
2180 			free(abspath);
2181 			if (err)
2182 				goto done;
2183 		}
2184 	}
2185 done:
2186 	free(tree_obj_id);
2187 	if (tree)
2188 		got_object_tree_close(tree);
2189 	if (err) {
2190 		free(*link_target);
2191 		*link_target = NULL;
2192 	}
2193 	return err;
2194 }
2195 
2196 const struct got_error *
2197 got_object_resolve_symlinks(char **link_target, const char *path,
2198     struct got_object_id *commit_id, struct got_repository *repo)
2199 {
2200 	const struct got_error *err = NULL;
2201 	char *next_target = NULL;
2202 	int max_recursion = 40; /* matches Git */
2203 
2204 	*link_target = NULL;
2205 
2206 	do {
2207 		err = resolve_symlink(&next_target,
2208 		    *link_target ? *link_target : path, commit_id, repo);
2209 		if (err)
2210 			break;
2211 		if (next_target) {
2212 			free(*link_target);
2213 			if (--max_recursion == 0) {
2214 				err = got_error_path(path, GOT_ERR_RECURSION);
2215 				*link_target = NULL;
2216 				break;
2217 			}
2218 			*link_target = next_target;
2219 		}
2220 	} while (next_target);
2221 
2222 	return err;
2223 }
2224 
2225 const struct got_error *
2226 got_traverse_packed_commits(struct got_object_id_queue *traversed_commits,
2227     struct got_object_id *commit_id, const char *path,
2228     struct got_repository *repo)
2229 {
2230 	const struct got_error *err = NULL;
2231 	struct got_pack *pack = NULL;
2232 	struct got_packidx *packidx = NULL;
2233 	char *path_packfile = NULL;
2234 	struct got_commit_object *changed_commit = NULL;
2235 	struct got_object_id *changed_commit_id = NULL;
2236 	int idx;
2237 
2238 	err = got_repo_search_packidx(&packidx, &idx, repo, commit_id);
2239 	if (err) {
2240 		if (err->code != GOT_ERR_NO_OBJ)
2241 			return err;
2242 		return NULL;
2243 	}
2244 
2245 	err = got_packidx_get_packfile_path(&path_packfile,
2246 	    packidx->path_packidx);
2247 	if (err)
2248 		return err;
2249 
2250 	pack = got_repo_get_cached_pack(repo, path_packfile);
2251 	if (pack == NULL) {
2252 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
2253 		if (err)
2254 			goto done;
2255 	}
2256 
2257 	if (pack->privsep_child == NULL) {
2258 		err = start_pack_privsep_child(pack, packidx);
2259 		if (err)
2260 			goto done;
2261 	}
2262 
2263 	err = got_privsep_send_commit_traversal_request(
2264 	    pack->privsep_child->ibuf, commit_id, idx, path);
2265 	if (err)
2266 		goto done;
2267 
2268 	err = got_privsep_recv_traversed_commits(&changed_commit,
2269 	    &changed_commit_id, traversed_commits, pack->privsep_child->ibuf);
2270 	if (err)
2271 		goto done;
2272 
2273 	if (changed_commit) {
2274 		/*
2275 		 * Cache the commit in which the path was changed.
2276 		 * This commit might be opened again soon.
2277 		 */
2278 		changed_commit->refcnt++;
2279 		err = got_repo_cache_commit(repo, changed_commit_id,
2280 		    changed_commit);
2281 		got_object_commit_close(changed_commit);
2282 	}
2283 done:
2284 	free(path_packfile);
2285 	free(changed_commit_id);
2286 	return err;
2287 }