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 <unistd.h>
33 #include <zlib.h>
34 #include <ctype.h>
35 #include <libgen.h>
36 #include <limits.h>
37 #include <time.h>
38 
39 #include "got_compat.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, size_t blocksize)
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 	(*obj)->blocksize = blocksize;
624 	err = got_repo_cache_raw_object(repo, id, *obj);
625 done:
626 	free(path_packfile);
627 	if (err) {
628 		if (*obj) {
629 			got_object_raw_close(*obj);
630 			*obj = NULL;
631 		}
632 		free(outbuf);
633 	} else
634 		(*obj)->refcnt++;
635 	return err;
636 }
637 
638 void
639 got_object_raw_rewind(struct got_raw_object *obj)
640 {
641 	if (obj->f)
642 		rewind(obj->f);
643 }
644 
645 size_t
646 got_object_raw_get_hdrlen(struct got_raw_object *obj)
647 {
648 	return obj->hdrlen;
649 }
650 
651 const uint8_t *
652 got_object_raw_get_read_buf(struct got_raw_object *obj)
653 {
654 	return obj->read_buf;
655 }
656 
657 const struct got_error *
658 got_object_raw_read_block(size_t *outlenp, struct got_raw_object *obj)
659 {
660 	size_t n;
661 
662 	n = fread(obj->read_buf, 1, obj->blocksize, obj->f);
663 	if (n == 0 && ferror(obj->f))
664 		return got_ferror(obj->f, GOT_ERR_IO);
665 	*outlenp = n;
666 	return NULL;
667 }
668 
669 const struct got_error *
670 got_object_open_by_id_str(struct got_object **obj, struct got_repository *repo,
671     const char *id_str)
672 {
673 	struct got_object_id id;
674 
675 	if (!got_parse_sha1_digest(id.sha1, id_str))
676 		return got_error_path(id_str, GOT_ERR_BAD_OBJ_ID_STR);
677 
678 	return got_object_open(obj, repo, &id);
679 }
680 
681 const struct got_error *
682 got_object_resolve_id_str(struct got_object_id **id,
683     struct got_repository *repo, const char *id_str)
684 {
685 	const struct got_error *err = NULL;
686 	struct got_object *obj;
687 
688 	err = got_object_open_by_id_str(&obj, repo, id_str);
689 	if (err)
690 		return err;
691 
692 	*id = got_object_id_dup(got_object_get_id(obj));
693 	got_object_close(obj);
694 	if (*id == NULL)
695 		return got_error_from_errno("got_object_id_dup");
696 
697 	return NULL;
698 }
699 
700 static const struct got_error *
701 request_packed_commit(struct got_commit_object **commit, struct got_pack *pack,
702     int pack_idx, struct got_object_id *id)
703 {
704 	const struct got_error *err = NULL;
705 
706 	err = got_privsep_send_commit_req(pack->privsep_child->ibuf, -1, id,
707 	    pack_idx);
708 	if (err)
709 		return err;
710 
711 	err = got_privsep_recv_commit(commit, pack->privsep_child->ibuf);
712 	if (err)
713 		return err;
714 
715 	(*commit)->flags |= GOT_COMMIT_FLAG_PACKED;
716 	return NULL;
717 }
718 
719 static const struct got_error *
720 read_packed_commit_privsep(struct got_commit_object **commit,
721     struct got_pack *pack, struct got_packidx *packidx, int idx,
722     struct got_object_id *id)
723 {
724 	const struct got_error *err = NULL;
725 
726 	if (pack->privsep_child)
727 		return request_packed_commit(commit, pack, idx, id);
728 
729 	err = start_pack_privsep_child(pack, packidx);
730 	if (err)
731 		return err;
732 
733 	return request_packed_commit(commit, pack, idx, id);
734 }
735 
736 static const struct got_error *
737 request_commit(struct got_commit_object **commit, struct got_repository *repo,
738     int fd, struct got_object_id *id)
739 {
740 	const struct got_error *err = NULL;
741 	struct imsgbuf *ibuf;
742 
743 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf;
744 
745 	err = got_privsep_send_commit_req(ibuf, fd, id, -1);
746 	if (err)
747 		return err;
748 
749 	return got_privsep_recv_commit(commit, ibuf);
750 }
751 
752 static const struct got_error *
753 read_commit_privsep(struct got_commit_object **commit, int obj_fd,
754     struct got_object_id *id, struct got_repository *repo)
755 {
756 	const struct got_error *err;
757 	int imsg_fds[2];
758 	pid_t pid;
759 	struct imsgbuf *ibuf;
760 
761 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd != -1)
762 		return request_commit(commit, repo, obj_fd, id);
763 
764 	ibuf = calloc(1, sizeof(*ibuf));
765 	if (ibuf == NULL)
766 		return got_error_from_errno("calloc");
767 
768 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
769 		err = got_error_from_errno("socketpair");
770 		free(ibuf);
771 		return err;
772 	}
773 
774 	pid = fork();
775 	if (pid == -1) {
776 		err = got_error_from_errno("fork");
777 		free(ibuf);
778 		return err;
779 	}
780 	else if (pid == 0) {
781 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_COMMIT,
782 		    repo->path);
783 		/* not reached */
784 	}
785 
786 	if (close(imsg_fds[1]) == -1) {
787 		err = got_error_from_errno("close");
788 		free(ibuf);
789 		return err;
790 	}
791 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd =
792 	    imsg_fds[0];
793 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].pid = pid;
794 	imsg_init(ibuf, imsg_fds[0]);
795 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf = ibuf;
796 
797 	return request_commit(commit, repo, obj_fd, id);
798 }
799 
800 
801 static const struct got_error *
802 open_commit(struct got_commit_object **commit,
803     struct got_repository *repo, struct got_object_id *id, int check_cache)
804 {
805 	const struct got_error *err = NULL;
806 	struct got_packidx *packidx = NULL;
807 	int idx;
808 	char *path_packfile = NULL;
809 
810 	if (check_cache) {
811 		*commit = got_repo_get_cached_commit(repo, id);
812 		if (*commit != NULL) {
813 			(*commit)->refcnt++;
814 			return NULL;
815 		}
816 	} else
817 		*commit = NULL;
818 
819 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
820 	if (err == NULL) {
821 		struct got_pack *pack = NULL;
822 
823 		err = got_packidx_get_packfile_path(&path_packfile,
824 		    packidx->path_packidx);
825 		if (err)
826 			return err;
827 
828 		pack = got_repo_get_cached_pack(repo, path_packfile);
829 		if (pack == NULL) {
830 			err = got_repo_cache_pack(&pack, repo, path_packfile,
831 			    packidx);
832 			if (err)
833 				goto done;
834 		}
835 		err = read_packed_commit_privsep(commit, pack,
836 		    packidx, idx, id);
837 	} else if (err->code == GOT_ERR_NO_OBJ) {
838 		int fd;
839 
840 		err = got_object_open_loose_fd(&fd, id, repo);
841 		if (err)
842 			return err;
843 		err = read_commit_privsep(commit, fd, id, repo);
844 	}
845 
846 	if (err == NULL) {
847 		(*commit)->refcnt++;
848 		err = got_repo_cache_commit(repo, id, *commit);
849 	}
850 done:
851 	free(path_packfile);
852 	return err;
853 }
854 
855 const struct got_error *
856 got_object_open_as_commit(struct got_commit_object **commit,
857     struct got_repository *repo, struct got_object_id *id)
858 {
859 	*commit = got_repo_get_cached_commit(repo, id);
860 	if (*commit != NULL) {
861 		(*commit)->refcnt++;
862 		return NULL;
863 	}
864 
865 	return open_commit(commit, repo, id, 0);
866 }
867 
868 const struct got_error *
869 got_object_commit_open(struct got_commit_object **commit,
870     struct got_repository *repo, struct got_object *obj)
871 {
872 	return open_commit(commit, repo, got_object_get_id(obj), 1);
873 }
874 
875 const struct got_error *
876 got_object_qid_alloc(struct got_object_qid **qid, struct got_object_id *id)
877 {
878 	const struct got_error *err = NULL;
879 
880 	*qid = calloc(1, sizeof(**qid));
881 	if (*qid == NULL)
882 		return got_error_from_errno("calloc");
883 
884 	(*qid)->id = got_object_id_dup(id);
885 	if ((*qid)->id == NULL) {
886 		err = got_error_from_errno("got_object_id_dup");
887 		got_object_qid_free(*qid);
888 		*qid = NULL;
889 		return err;
890 	}
891 
892 	return NULL;
893 }
894 
895 const struct got_error *
896 got_object_id_queue_copy(const struct got_object_id_queue *src,
897     struct got_object_id_queue *dest)
898 {
899 	const struct got_error *err;
900 	struct got_object_qid *qid;
901 
902 	STAILQ_FOREACH(qid, src, entry) {
903 		struct got_object_qid *new;
904 		/*
905 		 * Deep-copy the object ID only. Let the caller deal
906 		 * with setting up the new->data pointer if needed.
907 		 */
908 		err = got_object_qid_alloc(&new, qid->id); 
909 		if (err) {
910 			got_object_id_queue_free(dest);
911 			return err;
912 		}
913 		STAILQ_INSERT_TAIL(dest, new, entry);
914 	}
915 
916 	return NULL;
917 }
918 
919 static const struct got_error *
920 request_packed_tree(struct got_tree_object **tree, struct got_pack *pack,
921     int pack_idx, struct got_object_id *id)
922 {
923 	const struct got_error *err = NULL;
924 
925 	err = got_privsep_send_tree_req(pack->privsep_child->ibuf, -1, id,
926 	    pack_idx);
927 	if (err)
928 		return err;
929 
930 	return got_privsep_recv_tree(tree, pack->privsep_child->ibuf);
931 }
932 
933 static const struct got_error *
934 read_packed_tree_privsep(struct got_tree_object **tree,
935     struct got_pack *pack, struct got_packidx *packidx, int idx,
936     struct got_object_id *id)
937 {
938 	const struct got_error *err = NULL;
939 
940 	if (pack->privsep_child)
941 		return request_packed_tree(tree, pack, idx, id);
942 
943 	err = start_pack_privsep_child(pack, packidx);
944 	if (err)
945 		return err;
946 
947 	return request_packed_tree(tree, pack, idx, id);
948 }
949 
950 static const struct got_error *
951 request_tree(struct got_tree_object **tree, struct got_repository *repo,
952     int fd, struct got_object_id *id)
953 {
954 	const struct got_error *err = NULL;
955 	struct imsgbuf *ibuf;
956 
957 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf;
958 
959 	err = got_privsep_send_tree_req(ibuf, fd, id, -1);
960 	if (err)
961 		return err;
962 
963 	return got_privsep_recv_tree(tree, ibuf);
964 }
965 
966 const struct got_error *
967 read_tree_privsep(struct got_tree_object **tree, int obj_fd,
968     struct got_object_id *id, struct got_repository *repo)
969 {
970 	const struct got_error *err;
971 	int imsg_fds[2];
972 	pid_t pid;
973 	struct imsgbuf *ibuf;
974 
975 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd != -1)
976 		return request_tree(tree, repo, obj_fd, id);
977 
978 	ibuf = calloc(1, sizeof(*ibuf));
979 	if (ibuf == NULL)
980 		return got_error_from_errno("calloc");
981 
982 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
983 		err = got_error_from_errno("socketpair");
984 		free(ibuf);
985 		return err;
986 	}
987 
988 	pid = fork();
989 	if (pid == -1) {
990 		err = got_error_from_errno("fork");
991 		free(ibuf);
992 		return err;
993 	}
994 	else if (pid == 0) {
995 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TREE,
996 		    repo->path);
997 		/* not reached */
998 	}
999 
1000 	if (close(imsg_fds[1]) == -1) {
1001 		err = got_error_from_errno("close");
1002 		free(ibuf);
1003 		return err;
1004 	}
1005 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd =
1006 	    imsg_fds[0];
1007 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].pid = pid;
1008 	imsg_init(ibuf, imsg_fds[0]);
1009 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf = ibuf;
1010 
1011 
1012 	return request_tree(tree, repo, obj_fd, id);
1013 }
1014 
1015 static const struct got_error *
1016 open_tree(struct got_tree_object **tree, struct got_repository *repo,
1017     struct got_object_id *id, int check_cache)
1018 {
1019 	const struct got_error *err = NULL;
1020 	struct got_packidx *packidx = NULL;
1021 	int idx;
1022 	char *path_packfile = NULL;
1023 
1024 	if (check_cache) {
1025 		*tree = got_repo_get_cached_tree(repo, id);
1026 		if (*tree != NULL) {
1027 			(*tree)->refcnt++;
1028 			return NULL;
1029 		}
1030 	} else
1031 		*tree = NULL;
1032 
1033 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1034 	if (err == NULL) {
1035 		struct got_pack *pack = NULL;
1036 
1037 		err = got_packidx_get_packfile_path(&path_packfile,
1038 		    packidx->path_packidx);
1039 		if (err)
1040 			return err;
1041 
1042 		pack = got_repo_get_cached_pack(repo, path_packfile);
1043 		if (pack == NULL) {
1044 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1045 			    packidx);
1046 			if (err)
1047 				goto done;
1048 		}
1049 		err = read_packed_tree_privsep(tree, pack,
1050 		    packidx, idx, id);
1051 	} else if (err->code == GOT_ERR_NO_OBJ) {
1052 		int fd;
1053 
1054 		err = got_object_open_loose_fd(&fd, id, repo);
1055 		if (err)
1056 			return err;
1057 		err = read_tree_privsep(tree, fd, id, repo);
1058 	}
1059 
1060 	if (err == NULL) {
1061 		(*tree)->refcnt++;
1062 		err = got_repo_cache_tree(repo, id, *tree);
1063 	}
1064 done:
1065 	free(path_packfile);
1066 	return err;
1067 }
1068 
1069 const struct got_error *
1070 got_object_open_as_tree(struct got_tree_object **tree,
1071     struct got_repository *repo, struct got_object_id *id)
1072 {
1073 	*tree = got_repo_get_cached_tree(repo, id);
1074 	if (*tree != NULL) {
1075 		(*tree)->refcnt++;
1076 		return NULL;
1077 	}
1078 
1079 	return open_tree(tree, repo, id, 0);
1080 }
1081 
1082 const struct got_error *
1083 got_object_tree_open(struct got_tree_object **tree,
1084     struct got_repository *repo, struct got_object *obj)
1085 {
1086 	return open_tree(tree, repo, got_object_get_id(obj), 1);
1087 }
1088 
1089 int
1090 got_object_tree_get_nentries(struct got_tree_object *tree)
1091 {
1092 	return tree->nentries;
1093 }
1094 
1095 struct got_tree_entry *
1096 got_object_tree_get_first_entry(struct got_tree_object *tree)
1097 {
1098 	return got_object_tree_get_entry(tree, 0);
1099 }
1100 
1101 struct got_tree_entry *
1102 got_object_tree_get_last_entry(struct got_tree_object *tree)
1103 {
1104 	return got_object_tree_get_entry(tree, tree->nentries - 1);
1105 }
1106 
1107 struct got_tree_entry *
1108 got_object_tree_get_entry(struct got_tree_object *tree, int i)
1109 {
1110 	if (i < 0 || i >= tree->nentries)
1111 		return NULL;
1112 	return &tree->entries[i];
1113 }
1114 
1115 mode_t
1116 got_tree_entry_get_mode(struct got_tree_entry *te)
1117 {
1118 	return te->mode;
1119 }
1120 
1121 const char *
1122 got_tree_entry_get_name(struct got_tree_entry *te)
1123 {
1124 	return &te->name[0];
1125 }
1126 
1127 struct got_object_id *
1128 got_tree_entry_get_id(struct got_tree_entry *te)
1129 {
1130 	return &te->id;
1131 }
1132 
1133 const struct got_error *
1134 got_object_blob_read_to_str(char **s, struct got_blob_object *blob)
1135 {
1136 	const struct got_error *err = NULL;
1137 	size_t len, totlen, hdrlen, offset;
1138 
1139 	*s = NULL;
1140 
1141 	hdrlen = got_object_blob_get_hdrlen(blob);
1142 	totlen = 0;
1143 	offset = 0;
1144 	do {
1145 		char *p;
1146 
1147 		err = got_object_blob_read_block(&len, blob);
1148 		if (err)
1149 			return err;
1150 
1151 		if (len == 0)
1152 			break;
1153 
1154 		totlen += len - hdrlen;
1155 		p = realloc(*s, totlen + 1);
1156 		if (p == NULL) {
1157 			err = got_error_from_errno("realloc");
1158 			free(*s);
1159 			*s = NULL;
1160 			return err;
1161 		}
1162 		*s = p;
1163 		/* Skip blob object header first time around. */
1164 		memcpy(*s + offset,
1165 		    got_object_blob_get_read_buf(blob) + hdrlen, len - hdrlen);
1166 		hdrlen = 0;
1167 		offset = totlen;
1168 	} while (len > 0);
1169 
1170 	(*s)[totlen] = '\0';
1171 	return NULL;
1172 }
1173 
1174 const struct got_error *
1175 got_tree_entry_get_symlink_target(char **link_target, struct got_tree_entry *te,
1176     struct got_repository *repo)
1177 {
1178 	const struct got_error *err = NULL;
1179 	struct got_blob_object *blob = NULL;
1180 
1181 	*link_target = NULL;
1182 
1183 	if (!got_object_tree_entry_is_symlink(te))
1184 		return got_error(GOT_ERR_TREE_ENTRY_TYPE);
1185 
1186 	err = got_object_open_as_blob(&blob, repo,
1187 	    got_tree_entry_get_id(te), PATH_MAX);
1188 	if (err)
1189 		return err;
1190 
1191 	err = got_object_blob_read_to_str(link_target, blob);
1192 	got_object_blob_close(blob);
1193 	if (err) {
1194 		free(*link_target);
1195 		*link_target = NULL;
1196 	}
1197 	return err;
1198 }
1199 
1200 int
1201 got_tree_entry_get_index(struct got_tree_entry *te)
1202 {
1203 	return te->idx;
1204 }
1205 
1206 struct got_tree_entry *
1207 got_tree_entry_get_next(struct got_tree_object *tree,
1208     struct got_tree_entry *te)
1209 {
1210 	return got_object_tree_get_entry(tree, te->idx + 1);
1211 }
1212 
1213 struct got_tree_entry *
1214 got_tree_entry_get_prev(struct got_tree_object *tree,
1215     struct got_tree_entry *te)
1216 {
1217 	return got_object_tree_get_entry(tree, te->idx - 1);
1218 }
1219 
1220 static const struct got_error *
1221 request_packed_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
1222     struct got_pack *pack, struct got_packidx *packidx, int idx,
1223     struct got_object_id *id)
1224 {
1225 	const struct got_error *err = NULL;
1226 	int outfd_child;
1227 	int basefd, accumfd; /* temporary files for delta application */
1228 
1229 	basefd = got_opentempfd();
1230 	if (basefd == -1)
1231 		return got_error_from_errno("got_opentempfd");
1232 	accumfd = got_opentempfd();
1233 	if (accumfd == -1)
1234 		return got_error_from_errno("got_opentempfd");
1235 
1236 	outfd_child = dup(outfd);
1237 	if (outfd_child == -1)
1238 		return got_error_from_errno("dup");
1239 
1240 	err = got_privsep_send_blob_req(pack->privsep_child->ibuf, -1, id, idx);
1241 	if (err)
1242 		return err;
1243 
1244 	err = got_privsep_send_blob_outfd(pack->privsep_child->ibuf,
1245 	    outfd_child);
1246 	if (err) {
1247 		close(basefd);
1248 		close(accumfd);
1249 		return err;
1250 	}
1251 
1252 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
1253 	    basefd);
1254 	if (err) {
1255 		close(accumfd);
1256 		return err;
1257 	}
1258 
1259 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
1260 	    accumfd);
1261 	if (err)
1262 		return err;
1263 
1264 	err = got_privsep_recv_blob(outbuf, size, hdrlen,
1265 	    pack->privsep_child->ibuf);
1266 	if (err)
1267 		return err;
1268 
1269 	if (lseek(outfd, SEEK_SET, 0) == -1)
1270 		err = got_error_from_errno("lseek");
1271 
1272 	return err;
1273 }
1274 
1275 static const struct got_error *
1276 read_packed_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1277     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
1278     struct got_object_id *id)
1279 {
1280 	const struct got_error *err = NULL;
1281 
1282 	if (pack->privsep_child == NULL) {
1283 		err = start_pack_privsep_child(pack, packidx);
1284 		if (err)
1285 			return err;
1286 	}
1287 
1288 	return request_packed_blob(outbuf, size, hdrlen, outfd, pack, packidx,
1289 	    idx, id);
1290 }
1291 
1292 static const struct got_error *
1293 request_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
1294     int infd, struct got_object_id *id, struct imsgbuf *ibuf)
1295 {
1296 	const struct got_error *err = NULL;
1297 	int outfd_child;
1298 
1299 	outfd_child = dup(outfd);
1300 	if (outfd_child == -1)
1301 		return got_error_from_errno("dup");
1302 
1303 	err = got_privsep_send_blob_req(ibuf, infd, id, -1);
1304 	if (err)
1305 		return err;
1306 
1307 	err = got_privsep_send_blob_outfd(ibuf, outfd_child);
1308 	if (err)
1309 		return err;
1310 
1311 	err = got_privsep_recv_blob(outbuf, size, hdrlen, ibuf);
1312 	if (err)
1313 		return err;
1314 
1315 	if (lseek(outfd, SEEK_SET, 0) == -1)
1316 		return got_error_from_errno("lseek");
1317 
1318 	return err;
1319 }
1320 
1321 static const struct got_error *
1322 read_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1323     int outfd, int infd, struct got_object_id *id, struct got_repository *repo)
1324 {
1325 	const struct got_error *err;
1326 	int imsg_fds[2];
1327 	pid_t pid;
1328 	struct imsgbuf *ibuf;
1329 
1330 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd != -1) {
1331 		ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf;
1332 		return request_blob(outbuf, size, hdrlen, outfd, infd, id,
1333 		    ibuf);
1334 	}
1335 
1336 	ibuf = calloc(1, sizeof(*ibuf));
1337 	if (ibuf == NULL)
1338 		return got_error_from_errno("calloc");
1339 
1340 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1341 		err = got_error_from_errno("socketpair");
1342 		free(ibuf);
1343 		return err;
1344 	}
1345 
1346 	pid = fork();
1347 	if (pid == -1) {
1348 		err = got_error_from_errno("fork");
1349 		free(ibuf);
1350 		return err;
1351 	}
1352 	else if (pid == 0) {
1353 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_BLOB,
1354 		    repo->path);
1355 		/* not reached */
1356 	}
1357 
1358 	if (close(imsg_fds[1]) == -1) {
1359 		err = got_error_from_errno("close");
1360 		free(ibuf);
1361 		return err;
1362 	}
1363 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd =
1364 	    imsg_fds[0];
1365 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].pid = pid;
1366 	imsg_init(ibuf, imsg_fds[0]);
1367 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf = ibuf;
1368 
1369 	return request_blob(outbuf, size, hdrlen, outfd, infd, id, ibuf);
1370 }
1371 
1372 static const struct got_error *
1373 open_blob(struct got_blob_object **blob, struct got_repository *repo,
1374     struct got_object_id *id, size_t blocksize)
1375 {
1376 	const struct got_error *err = NULL;
1377 	struct got_packidx *packidx = NULL;
1378 	int idx;
1379 	char *path_packfile = NULL;
1380 	uint8_t *outbuf;
1381 	int outfd;
1382 	size_t size, hdrlen;
1383 	struct stat sb;
1384 
1385 	*blob = calloc(1, sizeof(**blob));
1386 	if (*blob == NULL)
1387 		return got_error_from_errno("calloc");
1388 
1389 	outfd = got_opentempfd();
1390 	if (outfd == -1)
1391 		return got_error_from_errno("got_opentempfd");
1392 
1393 	(*blob)->read_buf = malloc(blocksize);
1394 	if ((*blob)->read_buf == NULL) {
1395 		err = got_error_from_errno("malloc");
1396 		goto done;
1397 	}
1398 
1399 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1400 	if (err == NULL) {
1401 		struct got_pack *pack = NULL;
1402 
1403 		err = got_packidx_get_packfile_path(&path_packfile,
1404 		    packidx->path_packidx);
1405 		if (err)
1406 			goto done;
1407 
1408 		pack = got_repo_get_cached_pack(repo, path_packfile);
1409 		if (pack == NULL) {
1410 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1411 			    packidx);
1412 			if (err)
1413 				goto done;
1414 		}
1415 		err = read_packed_blob_privsep(&outbuf, &size, &hdrlen, outfd,
1416 		    pack, packidx, idx, id);
1417 	} else if (err->code == GOT_ERR_NO_OBJ) {
1418 		int infd;
1419 
1420 		err = got_object_open_loose_fd(&infd, id, repo);
1421 		if (err)
1422 			goto done;
1423 		err = read_blob_privsep(&outbuf, &size, &hdrlen, outfd, infd,
1424 		    id, repo);
1425 	}
1426 	if (err)
1427 		goto done;
1428 
1429 	if (hdrlen > size) {
1430 		err = got_error(GOT_ERR_BAD_OBJ_HDR);
1431 		goto done;
1432 	}
1433 
1434 	if (outbuf) {
1435 		if (close(outfd) == -1 && err == NULL)
1436 			err = got_error_from_errno("close");
1437 		outfd = -1;
1438 		(*blob)->f = fmemopen(outbuf, size, "rb");
1439 		if ((*blob)->f == NULL) {
1440 			err = got_error_from_errno("fmemopen");
1441 			free(outbuf);
1442 			goto done;
1443 		}
1444 		(*blob)->data = outbuf;
1445 	} else {
1446 		if (fstat(outfd, &sb) == -1) {
1447 			err = got_error_from_errno("fstat");
1448 			goto done;
1449 		}
1450 
1451 		if (sb.st_size != size) {
1452 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1453 			goto done;
1454 		}
1455 
1456 		(*blob)->f = fdopen(outfd, "rb");
1457 		if ((*blob)->f == NULL) {
1458 			err = got_error_from_errno("fdopen");
1459 			close(outfd);
1460 			outfd = -1;
1461 			goto done;
1462 		}
1463 	}
1464 
1465 	(*blob)->hdrlen = hdrlen;
1466 	(*blob)->blocksize = blocksize;
1467 	memcpy(&(*blob)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
1468 
1469 done:
1470 	free(path_packfile);
1471 	if (err) {
1472 		if (*blob) {
1473 			got_object_blob_close(*blob);
1474 			*blob = NULL;
1475 		} else if (outfd != -1)
1476 			close(outfd);
1477 	}
1478 	return err;
1479 }
1480 
1481 const struct got_error *
1482 got_object_open_as_blob(struct got_blob_object **blob,
1483     struct got_repository *repo, struct got_object_id *id,
1484     size_t blocksize)
1485 {
1486 	return open_blob(blob, repo, id, blocksize);
1487 }
1488 
1489 const struct got_error *
1490 got_object_blob_open(struct got_blob_object **blob,
1491     struct got_repository *repo, struct got_object *obj, size_t blocksize)
1492 {
1493 	return open_blob(blob, repo, got_object_get_id(obj), blocksize);
1494 }
1495 
1496 const struct got_error *
1497 got_object_blob_close(struct got_blob_object *blob)
1498 {
1499 	const struct got_error *err = NULL;
1500 	free(blob->read_buf);
1501 	if (blob->f && fclose(blob->f) == EOF)
1502 		err = got_error_from_errno("fclose");
1503 	free(blob->data);
1504 	free(blob);
1505 	return err;
1506 }
1507 
1508 void
1509 got_object_blob_rewind(struct got_blob_object *blob)
1510 {
1511 	if (blob->f)
1512 		rewind(blob->f);
1513 }
1514 
1515 char *
1516 got_object_blob_id_str(struct got_blob_object *blob, char *buf, size_t size)
1517 {
1518 	return got_sha1_digest_to_str(blob->id.sha1, buf, size);
1519 }
1520 
1521 size_t
1522 got_object_blob_get_hdrlen(struct got_blob_object *blob)
1523 {
1524 	return blob->hdrlen;
1525 }
1526 
1527 const uint8_t *
1528 got_object_blob_get_read_buf(struct got_blob_object *blob)
1529 {
1530 	return blob->read_buf;
1531 }
1532 
1533 const struct got_error *
1534 got_object_blob_read_block(size_t *outlenp, struct got_blob_object *blob)
1535 {
1536 	size_t n;
1537 
1538 	n = fread(blob->read_buf, 1, blob->blocksize, blob->f);
1539 	if (n == 0 && ferror(blob->f))
1540 		return got_ferror(blob->f, GOT_ERR_IO);
1541 	*outlenp = n;
1542 	return NULL;
1543 }
1544 
1545 const struct got_error *
1546 got_object_blob_dump_to_file(off_t *filesize, int *nlines,
1547     off_t **line_offsets, FILE *outfile, struct got_blob_object *blob)
1548 {
1549 	const struct got_error *err = NULL;
1550 	size_t n, len, hdrlen;
1551 	const uint8_t *buf;
1552 	int i;
1553 	const int alloc_chunksz = 512;
1554 	size_t nalloc = 0;
1555 	off_t off = 0, total_len = 0;
1556 
1557 	if (line_offsets)
1558 		*line_offsets = NULL;
1559 	if (filesize)
1560 		*filesize = 0;
1561 	if (nlines)
1562 		*nlines = 0;
1563 
1564 	hdrlen = got_object_blob_get_hdrlen(blob);
1565 	do {
1566 		err = got_object_blob_read_block(&len, blob);
1567 		if (err)
1568 			return err;
1569 		if (len == 0)
1570 			break;
1571 		buf = got_object_blob_get_read_buf(blob);
1572 		i = hdrlen;
1573 		if (nlines) {
1574 			if (line_offsets && *line_offsets == NULL) {
1575 				/* Have some data but perhaps no '\n'. */
1576 				*nlines = 1;
1577 				nalloc = alloc_chunksz;
1578 				*line_offsets = calloc(nalloc,
1579 				    sizeof(**line_offsets));
1580 				if (*line_offsets == NULL)
1581 					return got_error_from_errno("calloc");
1582 
1583 				/* Skip forward over end of first line. */
1584 				while (i < len) {
1585 					if (buf[i] == '\n')
1586 						break;
1587 					i++;
1588 				}
1589 			}
1590 			/* Scan '\n' offsets in remaining chunk of data. */
1591 			while (i < len) {
1592 				if (buf[i] != '\n') {
1593 					i++;
1594 					continue;
1595 				}
1596 				(*nlines)++;
1597 				if (line_offsets && nalloc < *nlines) {
1598 					size_t n = *nlines + alloc_chunksz;
1599 					off_t *o = recallocarray(*line_offsets,
1600 					    nalloc, n, sizeof(**line_offsets));
1601 					if (o == NULL) {
1602 						free(*line_offsets);
1603 						*line_offsets = NULL;
1604 						return got_error_from_errno(
1605 						    "recallocarray");
1606 					}
1607 					*line_offsets = o;
1608 					nalloc = n;
1609 				}
1610 				if (line_offsets) {
1611 					off = total_len + i - hdrlen + 1;
1612 					(*line_offsets)[*nlines - 1] = off;
1613 				}
1614 				i++;
1615 			}
1616 		}
1617 		/* Skip blob object header first time around. */
1618 		n = fwrite(buf + hdrlen, 1, len - hdrlen, outfile);
1619 		if (n != len - hdrlen)
1620 			return got_ferror(outfile, GOT_ERR_IO);
1621 		total_len += len - hdrlen;
1622 		hdrlen = 0;
1623 	} while (len != 0);
1624 
1625 	if (fflush(outfile) != 0)
1626 		return got_error_from_errno("fflush");
1627 	rewind(outfile);
1628 
1629 	if (filesize)
1630 		*filesize = total_len;
1631 
1632 	return NULL;
1633 }
1634 
1635 static const struct got_error *
1636 request_packed_tag(struct got_tag_object **tag, struct got_pack *pack,
1637     int pack_idx, struct got_object_id *id)
1638 {
1639 	const struct got_error *err = NULL;
1640 
1641 	err = got_privsep_send_tag_req(pack->privsep_child->ibuf, -1, id,
1642 	    pack_idx);
1643 	if (err)
1644 		return err;
1645 
1646 	return got_privsep_recv_tag(tag, pack->privsep_child->ibuf);
1647 }
1648 
1649 static const struct got_error *
1650 read_packed_tag_privsep(struct got_tag_object **tag,
1651     struct got_pack *pack, struct got_packidx *packidx, int idx,
1652     struct got_object_id *id)
1653 {
1654 	const struct got_error *err = NULL;
1655 
1656 	if (pack->privsep_child)
1657 		return request_packed_tag(tag, pack, idx, id);
1658 
1659 	err = start_pack_privsep_child(pack, packidx);
1660 	if (err)
1661 		return err;
1662 
1663 	return request_packed_tag(tag, pack, idx, id);
1664 }
1665 
1666 static const struct got_error *
1667 request_tag(struct got_tag_object **tag, struct got_repository *repo,
1668     int fd, struct got_object_id *id)
1669 {
1670 	const struct got_error *err = NULL;
1671 	struct imsgbuf *ibuf;
1672 
1673 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf;
1674 
1675 	err = got_privsep_send_tag_req(ibuf, fd, id, -1);
1676 	if (err)
1677 		return err;
1678 
1679 	return got_privsep_recv_tag(tag, ibuf);
1680 }
1681 
1682 static const struct got_error *
1683 read_tag_privsep(struct got_tag_object **tag, int obj_fd,
1684     struct got_object_id *id, struct got_repository *repo)
1685 {
1686 	const struct got_error *err;
1687 	int imsg_fds[2];
1688 	pid_t pid;
1689 	struct imsgbuf *ibuf;
1690 
1691 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd != -1)
1692 		return request_tag(tag, repo, obj_fd, id);
1693 
1694 	ibuf = calloc(1, sizeof(*ibuf));
1695 	if (ibuf == NULL)
1696 		return got_error_from_errno("calloc");
1697 
1698 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1699 		err = got_error_from_errno("socketpair");
1700 		free(ibuf);
1701 		return err;
1702 	}
1703 
1704 	pid = fork();
1705 	if (pid == -1) {
1706 		err = got_error_from_errno("fork");
1707 		free(ibuf);
1708 		return err;
1709 	}
1710 	else if (pid == 0) {
1711 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TAG,
1712 		    repo->path);
1713 		/* not reached */
1714 	}
1715 
1716 	if (close(imsg_fds[1]) == -1) {
1717 		err = got_error_from_errno("close");
1718 		free(ibuf);
1719 		return err;
1720 	}
1721 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd =
1722 	    imsg_fds[0];
1723 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].pid = pid;
1724 	imsg_init(ibuf, imsg_fds[0]);
1725 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf = ibuf;
1726 
1727 	return request_tag(tag, repo, obj_fd, id);
1728 }
1729 
1730 static const struct got_error *
1731 open_tag(struct got_tag_object **tag, struct got_repository *repo,
1732     struct got_object_id *id, int check_cache)
1733 {
1734 	const struct got_error *err = NULL;
1735 	struct got_packidx *packidx = NULL;
1736 	int idx;
1737 	char *path_packfile = NULL;
1738 	struct got_object *obj = NULL;
1739 	int obj_type = GOT_OBJ_TYPE_ANY;
1740 
1741 	if (check_cache) {
1742 		*tag = got_repo_get_cached_tag(repo, id);
1743 		if (*tag != NULL) {
1744 			(*tag)->refcnt++;
1745 			return NULL;
1746 		}
1747 	} else
1748 		*tag = NULL;
1749 
1750 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1751 	if (err == NULL) {
1752 		struct got_pack *pack = NULL;
1753 
1754 		err = got_packidx_get_packfile_path(&path_packfile,
1755 		    packidx->path_packidx);
1756 		if (err)
1757 			return err;
1758 
1759 		pack = got_repo_get_cached_pack(repo, path_packfile);
1760 		if (pack == NULL) {
1761 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1762 			    packidx);
1763 			if (err)
1764 				goto done;
1765 		}
1766 
1767 		/* Beware of "lightweight" tags: Check object type first. */
1768 		err = read_packed_object_privsep(&obj, repo, pack, packidx,
1769 		    idx, id);
1770 		if (err)
1771 			goto done;
1772 		obj_type = obj->type;
1773 		got_object_close(obj);
1774 		if (obj_type != GOT_OBJ_TYPE_TAG) {
1775 			err = got_error(GOT_ERR_OBJ_TYPE);
1776 			goto done;
1777 		}
1778 		err = read_packed_tag_privsep(tag, pack, packidx, idx, id);
1779 	} else if (err->code == GOT_ERR_NO_OBJ) {
1780 		int fd;
1781 
1782 		err = got_object_open_loose_fd(&fd, id, repo);
1783 		if (err)
1784 			return err;
1785 		err = got_object_read_header_privsep(&obj, id, repo, fd);
1786 		if (err)
1787 			return err;
1788 		obj_type = obj->type;
1789 		got_object_close(obj);
1790 		if (obj_type != GOT_OBJ_TYPE_TAG)
1791 			return got_error(GOT_ERR_OBJ_TYPE);
1792 
1793 		err = got_object_open_loose_fd(&fd, id, repo);
1794 		if (err)
1795 			return err;
1796 		err = read_tag_privsep(tag, fd, id, repo);
1797 	}
1798 
1799 	if (err == NULL) {
1800 		(*tag)->refcnt++;
1801 		err = got_repo_cache_tag(repo, id, *tag);
1802 	}
1803 done:
1804 	free(path_packfile);
1805 	return err;
1806 }
1807 
1808 const struct got_error *
1809 got_object_open_as_tag(struct got_tag_object **tag,
1810     struct got_repository *repo, struct got_object_id *id)
1811 {
1812 	*tag = got_repo_get_cached_tag(repo, id);
1813 	if (*tag != NULL) {
1814 		(*tag)->refcnt++;
1815 		return NULL;
1816 	}
1817 
1818 	return open_tag(tag, repo, id, 0);
1819 }
1820 
1821 const struct got_error *
1822 got_object_tag_open(struct got_tag_object **tag,
1823     struct got_repository *repo, struct got_object *obj)
1824 {
1825 	return open_tag(tag, repo, got_object_get_id(obj), 1);
1826 }
1827 
1828 const char *
1829 got_object_tag_get_name(struct got_tag_object *tag)
1830 {
1831 	return tag->tag;
1832 }
1833 
1834 int
1835 got_object_tag_get_object_type(struct got_tag_object *tag)
1836 {
1837 	return tag->obj_type;
1838 }
1839 
1840 struct got_object_id *
1841 got_object_tag_get_object_id(struct got_tag_object *tag)
1842 {
1843 	return &tag->id;
1844 }
1845 
1846 time_t
1847 got_object_tag_get_tagger_time(struct got_tag_object *tag)
1848 {
1849 	return tag->tagger_time;
1850 }
1851 
1852 time_t
1853 got_object_tag_get_tagger_gmtoff(struct got_tag_object *tag)
1854 {
1855 	return tag->tagger_gmtoff;
1856 }
1857 
1858 const char *
1859 got_object_tag_get_tagger(struct got_tag_object *tag)
1860 {
1861 	return tag->tagger;
1862 }
1863 
1864 const char *
1865 got_object_tag_get_message(struct got_tag_object *tag)
1866 {
1867 	return tag->tagmsg;
1868 }
1869 
1870 static struct got_tree_entry *
1871 find_entry_by_name(struct got_tree_object *tree, const char *name, size_t len)
1872 {
1873 	int i;
1874 
1875 	/* Note that tree entries are sorted in strncmp() order. */
1876 	for (i = 0; i < tree->nentries; i++) {
1877 		struct got_tree_entry *te = &tree->entries[i];
1878 		int cmp = strncmp(te->name, name, len);
1879 		if (cmp < 0)
1880 			continue;
1881 		if (cmp > 0)
1882 			break;
1883 		if (te->name[len] == '\0')
1884 			return te;
1885 	}
1886 	return NULL;
1887 }
1888 
1889 struct got_tree_entry *
1890 got_object_tree_find_entry(struct got_tree_object *tree, const char *name)
1891 {
1892 	return find_entry_by_name(tree, name, strlen(name));
1893 }
1894 
1895 const struct got_error *
1896 got_object_tree_find_path(struct got_object_id **id, mode_t *mode,
1897     struct got_repository *repo, struct got_tree_object *tree,
1898     const char *path)
1899 {
1900 	const struct got_error *err = NULL;
1901 	struct got_tree_object *subtree = NULL;
1902 	struct got_tree_entry *te = NULL;
1903 	const char *seg, *s;
1904 	size_t seglen;
1905 
1906 	*id = NULL;
1907 
1908 	s = path;
1909 	while (s[0] == '/')
1910 		s++;
1911 	seg = s;
1912 	seglen = 0;
1913 	subtree = tree;
1914 	while (*s) {
1915 		struct got_tree_object *next_tree;
1916 
1917 		if (*s != '/') {
1918 			s++;
1919 			seglen++;
1920 			if (*s)
1921 				continue;
1922 		}
1923 
1924 		te = find_entry_by_name(subtree, seg, seglen);
1925 		if (te == NULL) {
1926 			err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
1927 			goto done;
1928 		}
1929 
1930 		if (*s == '\0')
1931 			break;
1932 
1933 		seg = s + 1;
1934 		seglen = 0;
1935 		s++;
1936 		if (*s) {
1937 			err = got_object_open_as_tree(&next_tree, repo,
1938 			    &te->id);
1939 			te = NULL;
1940 			if (err)
1941 				goto done;
1942 			if (subtree != tree)
1943 				got_object_tree_close(subtree);
1944 			subtree = next_tree;
1945 		}
1946 	}
1947 
1948 	if (te) {
1949 		*id = got_object_id_dup(&te->id);
1950 		if (*id == NULL)
1951 			return got_error_from_errno("got_object_id_dup");
1952 		if (mode)
1953 			*mode = te->mode;
1954 	} else
1955 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
1956 done:
1957 	if (subtree && subtree != tree)
1958 		got_object_tree_close(subtree);
1959 	return err;
1960 }
1961 const struct got_error *
1962 got_object_id_by_path(struct got_object_id **id, struct got_repository *repo,
1963     struct got_object_id *commit_id, const char *path)
1964 {
1965 	const struct got_error *err = NULL;
1966 	struct got_commit_object *commit = NULL;
1967 	struct got_tree_object *tree = NULL;
1968 
1969 	*id = NULL;
1970 
1971 	err = got_object_open_as_commit(&commit, repo, commit_id);
1972 	if (err)
1973 		goto done;
1974 
1975 	/* Handle opening of root of commit's tree. */
1976 	if (got_path_is_root_dir(path)) {
1977 		*id = got_object_id_dup(commit->tree_id);
1978 		if (*id == NULL)
1979 			err = got_error_from_errno("got_object_id_dup");
1980 	} else {
1981 		err = got_object_open_as_tree(&tree, repo, commit->tree_id);
1982 		if (err)
1983 			goto done;
1984 		err = got_object_tree_find_path(id, NULL, repo, tree, path);
1985 	}
1986 done:
1987 	if (commit)
1988 		got_object_commit_close(commit);
1989 	if (tree)
1990 		got_object_tree_close(tree);
1991 	return err;
1992 }
1993 
1994 /*
1995  * Normalize file mode bits to avoid false positive tree entry differences
1996  * in case tree entries have unexpected mode bits set.
1997  */
1998 static mode_t
1999 normalize_mode_for_comparison(mode_t mode)
2000 {
2001 	/*
2002 	 * For directories, the only relevant bit is the IFDIR bit.
2003 	 * This allows us to detect paths changing from a directory
2004 	 * to a file and vice versa.
2005 	 */
2006 	if (S_ISDIR(mode))
2007 		return mode & S_IFDIR;
2008 
2009 	/*
2010 	 * For symlinks, the only relevant bit is the IFLNK bit.
2011 	 * This allows us to detect paths changing from a symlinks
2012 	 * to a file or directory and vice versa.
2013 	 */
2014 	if (S_ISLNK(mode))
2015 		return mode & S_IFLNK;
2016 
2017 	/* For files, the only change we care about is the executable bit. */
2018 	return mode & S_IXUSR;
2019 }
2020 
2021 const struct got_error *
2022 got_object_tree_path_changed(int *changed,
2023     struct got_tree_object *tree01, struct got_tree_object *tree02,
2024     const char *path, struct got_repository *repo)
2025 {
2026 	const struct got_error *err = NULL;
2027 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
2028 	struct got_tree_entry *te1 = NULL, *te2 = NULL;
2029 	const char *seg, *s;
2030 	size_t seglen;
2031 
2032 	*changed = 0;
2033 
2034 	/* We not do support comparing the root path. */
2035 	if (got_path_is_root_dir(path))
2036 		return got_error_path(path, GOT_ERR_BAD_PATH);
2037 
2038 	tree1 = tree01;
2039 	tree2 = tree02;
2040 	s = path;
2041 	while (*s == '/')
2042 		s++;
2043 	seg = s;
2044 	seglen = 0;
2045 	while (*s) {
2046 		struct got_tree_object *next_tree1, *next_tree2;
2047 		mode_t mode1, mode2;
2048 
2049 		if (*s != '/') {
2050 			s++;
2051 			seglen++;
2052 			if (*s)
2053 				continue;
2054 		}
2055 
2056 		te1 = find_entry_by_name(tree1, seg, seglen);
2057 		if (te1 == NULL) {
2058 			err = got_error(GOT_ERR_NO_OBJ);
2059 			goto done;
2060 		}
2061 
2062 		if (tree2)
2063 			te2 = find_entry_by_name(tree2, seg, seglen);
2064 
2065 		if (te2) {
2066 			mode1 = normalize_mode_for_comparison(te1->mode);
2067 			mode2 = normalize_mode_for_comparison(te2->mode);
2068 			if (mode1 != mode2) {
2069 				*changed = 1;
2070 				goto done;
2071 			}
2072 
2073 			if (got_object_id_cmp(&te1->id, &te2->id) == 0) {
2074 				*changed = 0;
2075 				goto done;
2076 			}
2077 		}
2078 
2079 		if (*s == '\0') { /* final path element */
2080 			*changed = 1;
2081 			goto done;
2082 		}
2083 
2084 		seg = s + 1;
2085 		s++;
2086 		seglen = 0;
2087 		if (*s) {
2088 			err = got_object_open_as_tree(&next_tree1, repo,
2089 			    &te1->id);
2090 			te1 = NULL;
2091 			if (err)
2092 				goto done;
2093 			if (tree1 != tree01)
2094 				got_object_tree_close(tree1);
2095 			tree1 = next_tree1;
2096 
2097 			if (te2) {
2098 				err = got_object_open_as_tree(&next_tree2, repo,
2099 				    &te2->id);
2100 				te2 = NULL;
2101 				if (err)
2102 					goto done;
2103 				if (tree2 != tree02)
2104 					got_object_tree_close(tree2);
2105 				tree2 = next_tree2;
2106 			} else if (tree2) {
2107 				if (tree2 != tree02)
2108 					got_object_tree_close(tree2);
2109 				tree2 = NULL;
2110 			}
2111 		}
2112 	}
2113 done:
2114 	if (tree1 && tree1 != tree01)
2115 		got_object_tree_close(tree1);
2116 	if (tree2 && tree2 != tree02)
2117 		got_object_tree_close(tree2);
2118 	return err;
2119 }
2120 
2121 const struct got_error *
2122 got_object_tree_entry_dup(struct got_tree_entry **new_te,
2123     struct got_tree_entry *te)
2124 {
2125 	const struct got_error *err = NULL;
2126 
2127 	*new_te = calloc(1, sizeof(**new_te));
2128 	if (*new_te == NULL)
2129 		return got_error_from_errno("calloc");
2130 
2131 	(*new_te)->mode = te->mode;
2132 	memcpy((*new_te)->name, te->name, sizeof((*new_te)->name));
2133 	memcpy(&(*new_te)->id, &te->id, sizeof((*new_te)->id));
2134 	return err;
2135 }
2136 
2137 int
2138 got_object_tree_entry_is_submodule(struct got_tree_entry *te)
2139 {
2140 	return (te->mode & S_IFMT) == (S_IFDIR | S_IFLNK);
2141 }
2142 
2143 int
2144 got_object_tree_entry_is_symlink(struct got_tree_entry *te)
2145 {
2146 	/* S_IFDIR check avoids confusing symlinks with submodules. */
2147 	return ((te->mode & (S_IFDIR | S_IFLNK)) == S_IFLNK);
2148 }
2149 
2150 static const struct got_error *
2151 resolve_symlink(char **link_target, const char *path,
2152     struct got_object_id *commit_id, struct got_repository *repo)
2153 {
2154 	const struct got_error *err = NULL;
2155 	char buf[PATH_MAX];
2156 	char *name, *parent_path = NULL;
2157 	struct got_object_id *tree_obj_id = NULL;
2158 	struct got_tree_object *tree = NULL;
2159 	struct got_tree_entry *te = NULL;
2160 
2161 	*link_target = NULL;
2162 
2163 	if (strlcpy(buf, path, sizeof(buf)) >= sizeof(buf))
2164 		return got_error(GOT_ERR_NO_SPACE);
2165 
2166 	name = basename(buf);
2167 	if (name == NULL)
2168 		return got_error_from_errno2("basename", path);
2169 
2170 	err = got_path_dirname(&parent_path, path);
2171 	if (err)
2172 		return err;
2173 
2174 	err = got_object_id_by_path(&tree_obj_id, repo, commit_id,
2175 	    parent_path);
2176 	if (err) {
2177 		if (err->code == GOT_ERR_NO_TREE_ENTRY) {
2178 			/* Display the complete path in error message. */
2179 			err = got_error_path(path, err->code);
2180 		}
2181 		goto done;
2182 	}
2183 
2184 	err = got_object_open_as_tree(&tree, repo, tree_obj_id);
2185 	if (err)
2186 		goto done;
2187 
2188 	te = got_object_tree_find_entry(tree, name);
2189 	if (te == NULL) {
2190 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
2191 		goto done;
2192 	}
2193 
2194 	if (got_object_tree_entry_is_symlink(te)) {
2195 		err = got_tree_entry_get_symlink_target(link_target, te, repo);
2196 		if (err)
2197 			goto done;
2198 		if (!got_path_is_absolute(*link_target)) {
2199 			char *abspath;
2200 			if (asprintf(&abspath, "%s/%s", parent_path,
2201 			    *link_target) == -1) {
2202 				err = got_error_from_errno("asprintf");
2203 				goto done;
2204 			}
2205 			free(*link_target);
2206 			*link_target = malloc(PATH_MAX);
2207 			if (*link_target == NULL) {
2208 				err = got_error_from_errno("malloc");
2209 				goto done;
2210 			}
2211 			err = got_canonpath(abspath, *link_target, PATH_MAX);
2212 			free(abspath);
2213 			if (err)
2214 				goto done;
2215 		}
2216 	}
2217 done:
2218 	free(tree_obj_id);
2219 	if (tree)
2220 		got_object_tree_close(tree);
2221 	if (err) {
2222 		free(*link_target);
2223 		*link_target = NULL;
2224 	}
2225 	return err;
2226 }
2227 
2228 const struct got_error *
2229 got_object_resolve_symlinks(char **link_target, const char *path,
2230     struct got_object_id *commit_id, struct got_repository *repo)
2231 {
2232 	const struct got_error *err = NULL;
2233 	char *next_target = NULL;
2234 	int max_recursion = 40; /* matches Git */
2235 
2236 	*link_target = NULL;
2237 
2238 	do {
2239 		err = resolve_symlink(&next_target,
2240 		    *link_target ? *link_target : path, commit_id, repo);
2241 		if (err)
2242 			break;
2243 		if (next_target) {
2244 			free(*link_target);
2245 			if (--max_recursion == 0) {
2246 				err = got_error_path(path, GOT_ERR_RECURSION);
2247 				*link_target = NULL;
2248 				break;
2249 			}
2250 			*link_target = next_target;
2251 		}
2252 	} while (next_target);
2253 
2254 	return err;
2255 }
2256 
2257 const struct got_error *
2258 got_traverse_packed_commits(struct got_object_id_queue *traversed_commits,
2259     struct got_object_id *commit_id, const char *path,
2260     struct got_repository *repo)
2261 {
2262 	const struct got_error *err = NULL;
2263 	struct got_pack *pack = NULL;
2264 	struct got_packidx *packidx = NULL;
2265 	char *path_packfile = NULL;
2266 	struct got_commit_object *changed_commit = NULL;
2267 	struct got_object_id *changed_commit_id = NULL;
2268 	int idx;
2269 
2270 	err = got_repo_search_packidx(&packidx, &idx, repo, commit_id);
2271 	if (err) {
2272 		if (err->code != GOT_ERR_NO_OBJ)
2273 			return err;
2274 		return NULL;
2275 	}
2276 
2277 	err = got_packidx_get_packfile_path(&path_packfile,
2278 	    packidx->path_packidx);
2279 	if (err)
2280 		return err;
2281 
2282 	pack = got_repo_get_cached_pack(repo, path_packfile);
2283 	if (pack == NULL) {
2284 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
2285 		if (err)
2286 			goto done;
2287 	}
2288 
2289 	if (pack->privsep_child == NULL) {
2290 		err = start_pack_privsep_child(pack, packidx);
2291 		if (err)
2292 			goto done;
2293 	}
2294 
2295 	err = got_privsep_send_commit_traversal_request(
2296 	    pack->privsep_child->ibuf, commit_id, idx, path);
2297 	if (err)
2298 		goto done;
2299 
2300 	err = got_privsep_recv_traversed_commits(&changed_commit,
2301 	    &changed_commit_id, traversed_commits, pack->privsep_child->ibuf);
2302 	if (err)
2303 		goto done;
2304 
2305 	if (changed_commit) {
2306 		/*
2307 		 * Cache the commit in which the path was changed.
2308 		 * This commit might be opened again soon.
2309 		 */
2310 		changed_commit->refcnt++;
2311 		err = got_repo_cache_commit(repo, changed_commit_id,
2312 		    changed_commit);
2313 		got_object_commit_close(changed_commit);
2314 	}
2315 done:
2316 	free(path_packfile);
2317 	free(changed_commit_id);
2318 	return err;
2319 }