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 const struct got_error *
532 got_object_raw_open(struct got_raw_object **obj, int outfd,
533     struct got_repository *repo, struct got_object_id *id, size_t blocksize)
534 {
535 	const struct got_error *err = NULL;
536 	struct got_packidx *packidx = NULL;
537 	int idx;
538 	uint8_t *outbuf = NULL;
539 	off_t size = 0;
540 	size_t hdrlen = 0;
541 	char *path_packfile = NULL;
542 
543 	*obj = NULL;
544 
545 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
546 	if (err == NULL) {
547 		struct got_pack *pack = NULL;
548 
549 		err = got_packidx_get_packfile_path(&path_packfile,
550 		    packidx->path_packidx);
551 		if (err)
552 			goto done;
553 
554 		pack = got_repo_get_cached_pack(repo, path_packfile);
555 		if (pack == NULL) {
556 			err = got_repo_cache_pack(&pack, repo, path_packfile,
557 			    packidx);
558 			if (err)
559 				goto done;
560 		}
561 		err = read_packed_object_raw_privsep(&outbuf, &size, &hdrlen,
562 		    outfd, pack, packidx, idx, id);
563 		if (err)
564 			goto done;
565 	} else if (err->code == GOT_ERR_NO_OBJ) {
566 		int fd;
567 
568 		err = got_object_open_loose_fd(&fd, id, repo);
569 		if (err)
570 			goto done;
571 		err = read_object_raw_privsep(&outbuf, &size, &hdrlen, outfd,
572 		    id, repo, fd);
573 		if (err)
574 			goto done;
575 	}
576 
577 	*obj = calloc(1, sizeof(**obj));
578 	if (*obj == NULL) {
579 		err = got_error_from_errno("calloc");
580 		goto done;
581 	}
582 
583 	(*obj)->read_buf = malloc(blocksize);
584 	if ((*obj)->read_buf == NULL) {
585 		err = got_error_from_errno("malloc");
586 		goto done;
587 	}
588 
589 	if (outbuf) {
590 		(*obj)->f = fmemopen(outbuf, hdrlen + size, "r");
591 		if ((*obj)->f == NULL) {
592 			err = got_error_from_errno("fdopen");
593 			goto done;
594 		}
595 		(*obj)->data = outbuf;
596 	} else {
597 		struct stat sb;
598 		if (fstat(outfd, &sb) == -1) {
599 			err = got_error_from_errno("fstat");
600 			goto done;
601 		}
602 
603 		if (sb.st_size != hdrlen + size) {
604 			err = got_error(GOT_ERR_PRIVSEP_LEN);
605 			goto done;
606 		}
607 
608 		(*obj)->f = fdopen(outfd, "r");
609 		if ((*obj)->f == NULL) {
610 			err = got_error_from_errno("fdopen");
611 			goto done;
612 		}
613 		(*obj)->data = NULL;
614 	}
615 	(*obj)->hdrlen = hdrlen;
616 	(*obj)->size = size;
617 	(*obj)->blocksize = blocksize;
618 done:
619 	free(path_packfile);
620 	if (err) {
621 		if (*obj) {
622 			got_object_raw_close(*obj);
623 			*obj = NULL;
624 		}
625 		free(outbuf);
626 	}
627 	return err;
628 }
629 
630 void
631 got_object_raw_rewind(struct got_raw_object *obj)
632 {
633 	if (obj->f)
634 		rewind(obj->f);
635 }
636 
637 size_t
638 got_object_raw_get_hdrlen(struct got_raw_object *obj)
639 {
640 	return obj->hdrlen;
641 }
642 
643 const uint8_t *
644 got_object_raw_get_read_buf(struct got_raw_object *obj)
645 {
646 	return obj->read_buf;
647 }
648 
649 const struct got_error *
650 got_object_raw_read_block(size_t *outlenp, struct got_raw_object *obj)
651 {
652 	size_t n;
653 
654 	n = fread(obj->read_buf, 1, obj->blocksize, obj->f);
655 	if (n == 0 && ferror(obj->f))
656 		return got_ferror(obj->f, GOT_ERR_IO);
657 	*outlenp = n;
658 	return NULL;
659 }
660 
661 const struct got_error *
662 got_object_raw_close(struct got_raw_object *obj)
663 {
664 	const struct got_error *err = NULL;
665 
666 	free(obj->read_buf);
667 	if (obj->f != NULL && fclose(obj->f) == EOF && err == NULL)
668 		err = got_error_from_errno("fclose");
669 	free(obj->data);
670 	free(obj);
671 	return err;
672 }
673 
674 const struct got_error *
675 got_object_open_by_id_str(struct got_object **obj, struct got_repository *repo,
676     const char *id_str)
677 {
678 	struct got_object_id id;
679 
680 	if (!got_parse_sha1_digest(id.sha1, id_str))
681 		return got_error_path(id_str, GOT_ERR_BAD_OBJ_ID_STR);
682 
683 	return got_object_open(obj, repo, &id);
684 }
685 
686 const struct got_error *
687 got_object_resolve_id_str(struct got_object_id **id,
688     struct got_repository *repo, const char *id_str)
689 {
690 	const struct got_error *err = NULL;
691 	struct got_object *obj;
692 
693 	err = got_object_open_by_id_str(&obj, repo, id_str);
694 	if (err)
695 		return err;
696 
697 	*id = got_object_id_dup(got_object_get_id(obj));
698 	got_object_close(obj);
699 	if (*id == NULL)
700 		return got_error_from_errno("got_object_id_dup");
701 
702 	return NULL;
703 }
704 
705 static const struct got_error *
706 request_packed_commit(struct got_commit_object **commit, struct got_pack *pack,
707     int pack_idx, struct got_object_id *id)
708 {
709 	const struct got_error *err = NULL;
710 
711 	err = got_privsep_send_commit_req(pack->privsep_child->ibuf, -1, id,
712 	    pack_idx);
713 	if (err)
714 		return err;
715 
716 	err = got_privsep_recv_commit(commit, pack->privsep_child->ibuf);
717 	if (err)
718 		return err;
719 
720 	(*commit)->flags |= GOT_COMMIT_FLAG_PACKED;
721 	return NULL;
722 }
723 
724 static const struct got_error *
725 read_packed_commit_privsep(struct got_commit_object **commit,
726     struct got_pack *pack, struct got_packidx *packidx, int idx,
727     struct got_object_id *id)
728 {
729 	const struct got_error *err = NULL;
730 
731 	if (pack->privsep_child)
732 		return request_packed_commit(commit, pack, idx, id);
733 
734 	err = start_pack_privsep_child(pack, packidx);
735 	if (err)
736 		return err;
737 
738 	return request_packed_commit(commit, pack, idx, id);
739 }
740 
741 static const struct got_error *
742 request_commit(struct got_commit_object **commit, struct got_repository *repo,
743     int fd, struct got_object_id *id)
744 {
745 	const struct got_error *err = NULL;
746 	struct imsgbuf *ibuf;
747 
748 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf;
749 
750 	err = got_privsep_send_commit_req(ibuf, fd, id, -1);
751 	if (err)
752 		return err;
753 
754 	return got_privsep_recv_commit(commit, ibuf);
755 }
756 
757 static const struct got_error *
758 read_commit_privsep(struct got_commit_object **commit, int obj_fd,
759     struct got_object_id *id, struct got_repository *repo)
760 {
761 	const struct got_error *err;
762 	int imsg_fds[2];
763 	pid_t pid;
764 	struct imsgbuf *ibuf;
765 
766 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd != -1)
767 		return request_commit(commit, repo, obj_fd, id);
768 
769 	ibuf = calloc(1, sizeof(*ibuf));
770 	if (ibuf == NULL)
771 		return got_error_from_errno("calloc");
772 
773 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
774 		err = got_error_from_errno("socketpair");
775 		free(ibuf);
776 		return err;
777 	}
778 
779 	pid = fork();
780 	if (pid == -1) {
781 		err = got_error_from_errno("fork");
782 		free(ibuf);
783 		return err;
784 	}
785 	else if (pid == 0) {
786 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_COMMIT,
787 		    repo->path);
788 		/* not reached */
789 	}
790 
791 	if (close(imsg_fds[1]) == -1) {
792 		err = got_error_from_errno("close");
793 		free(ibuf);
794 		return err;
795 	}
796 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd =
797 	    imsg_fds[0];
798 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].pid = pid;
799 	imsg_init(ibuf, imsg_fds[0]);
800 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf = ibuf;
801 
802 	return request_commit(commit, repo, obj_fd, id);
803 }
804 
805 
806 static const struct got_error *
807 open_commit(struct got_commit_object **commit,
808     struct got_repository *repo, struct got_object_id *id, int check_cache)
809 {
810 	const struct got_error *err = NULL;
811 	struct got_packidx *packidx = NULL;
812 	int idx;
813 	char *path_packfile = NULL;
814 
815 	if (check_cache) {
816 		*commit = got_repo_get_cached_commit(repo, id);
817 		if (*commit != NULL) {
818 			(*commit)->refcnt++;
819 			return NULL;
820 		}
821 	} else
822 		*commit = NULL;
823 
824 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
825 	if (err == NULL) {
826 		struct got_pack *pack = NULL;
827 
828 		err = got_packidx_get_packfile_path(&path_packfile,
829 		    packidx->path_packidx);
830 		if (err)
831 			return err;
832 
833 		pack = got_repo_get_cached_pack(repo, path_packfile);
834 		if (pack == NULL) {
835 			err = got_repo_cache_pack(&pack, repo, path_packfile,
836 			    packidx);
837 			if (err)
838 				goto done;
839 		}
840 		err = read_packed_commit_privsep(commit, pack,
841 		    packidx, idx, id);
842 	} else if (err->code == GOT_ERR_NO_OBJ) {
843 		int fd;
844 
845 		err = got_object_open_loose_fd(&fd, id, repo);
846 		if (err)
847 			return err;
848 		err = read_commit_privsep(commit, fd, id, repo);
849 	}
850 
851 	if (err == NULL) {
852 		(*commit)->refcnt++;
853 		err = got_repo_cache_commit(repo, id, *commit);
854 	}
855 done:
856 	free(path_packfile);
857 	return err;
858 }
859 
860 const struct got_error *
861 got_object_open_as_commit(struct got_commit_object **commit,
862     struct got_repository *repo, struct got_object_id *id)
863 {
864 	*commit = got_repo_get_cached_commit(repo, id);
865 	if (*commit != NULL) {
866 		(*commit)->refcnt++;
867 		return NULL;
868 	}
869 
870 	return open_commit(commit, repo, id, 0);
871 }
872 
873 const struct got_error *
874 got_object_commit_open(struct got_commit_object **commit,
875     struct got_repository *repo, struct got_object *obj)
876 {
877 	return open_commit(commit, repo, got_object_get_id(obj), 1);
878 }
879 
880 const struct got_error *
881 got_object_qid_alloc(struct got_object_qid **qid, struct got_object_id *id)
882 {
883 	const struct got_error *err = NULL;
884 
885 	*qid = calloc(1, sizeof(**qid));
886 	if (*qid == NULL)
887 		return got_error_from_errno("calloc");
888 
889 	(*qid)->id = got_object_id_dup(id);
890 	if ((*qid)->id == NULL) {
891 		err = got_error_from_errno("got_object_id_dup");
892 		got_object_qid_free(*qid);
893 		*qid = NULL;
894 		return err;
895 	}
896 
897 	return NULL;
898 }
899 
900 const struct got_error *
901 got_object_id_queue_copy(const struct got_object_id_queue *src,
902     struct got_object_id_queue *dest)
903 {
904 	const struct got_error *err;
905 	struct got_object_qid *qid;
906 
907 	STAILQ_FOREACH(qid, src, entry) {
908 		struct got_object_qid *new;
909 		/*
910 		 * Deep-copy the object ID only. Let the caller deal
911 		 * with setting up the new->data pointer if needed.
912 		 */
913 		err = got_object_qid_alloc(&new, qid->id); 
914 		if (err) {
915 			got_object_id_queue_free(dest);
916 			return err;
917 		}
918 		STAILQ_INSERT_TAIL(dest, new, entry);
919 	}
920 
921 	return NULL;
922 }
923 
924 static const struct got_error *
925 request_packed_tree(struct got_tree_object **tree, struct got_pack *pack,
926     int pack_idx, struct got_object_id *id)
927 {
928 	const struct got_error *err = NULL;
929 
930 	err = got_privsep_send_tree_req(pack->privsep_child->ibuf, -1, id,
931 	    pack_idx);
932 	if (err)
933 		return err;
934 
935 	return got_privsep_recv_tree(tree, pack->privsep_child->ibuf);
936 }
937 
938 static const struct got_error *
939 read_packed_tree_privsep(struct got_tree_object **tree,
940     struct got_pack *pack, struct got_packidx *packidx, int idx,
941     struct got_object_id *id)
942 {
943 	const struct got_error *err = NULL;
944 
945 	if (pack->privsep_child)
946 		return request_packed_tree(tree, pack, idx, id);
947 
948 	err = start_pack_privsep_child(pack, packidx);
949 	if (err)
950 		return err;
951 
952 	return request_packed_tree(tree, pack, idx, id);
953 }
954 
955 static const struct got_error *
956 request_tree(struct got_tree_object **tree, struct got_repository *repo,
957     int fd, struct got_object_id *id)
958 {
959 	const struct got_error *err = NULL;
960 	struct imsgbuf *ibuf;
961 
962 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf;
963 
964 	err = got_privsep_send_tree_req(ibuf, fd, id, -1);
965 	if (err)
966 		return err;
967 
968 	return got_privsep_recv_tree(tree, ibuf);
969 }
970 
971 const struct got_error *
972 read_tree_privsep(struct got_tree_object **tree, int obj_fd,
973     struct got_object_id *id, struct got_repository *repo)
974 {
975 	const struct got_error *err;
976 	int imsg_fds[2];
977 	pid_t pid;
978 	struct imsgbuf *ibuf;
979 
980 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd != -1)
981 		return request_tree(tree, repo, obj_fd, id);
982 
983 	ibuf = calloc(1, sizeof(*ibuf));
984 	if (ibuf == NULL)
985 		return got_error_from_errno("calloc");
986 
987 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
988 		err = got_error_from_errno("socketpair");
989 		free(ibuf);
990 		return err;
991 	}
992 
993 	pid = fork();
994 	if (pid == -1) {
995 		err = got_error_from_errno("fork");
996 		free(ibuf);
997 		return err;
998 	}
999 	else if (pid == 0) {
1000 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TREE,
1001 		    repo->path);
1002 		/* not reached */
1003 	}
1004 
1005 	if (close(imsg_fds[1]) == -1) {
1006 		err = got_error_from_errno("close");
1007 		free(ibuf);
1008 		return err;
1009 	}
1010 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd =
1011 	    imsg_fds[0];
1012 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].pid = pid;
1013 	imsg_init(ibuf, imsg_fds[0]);
1014 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf = ibuf;
1015 
1016 
1017 	return request_tree(tree, repo, obj_fd, id);
1018 }
1019 
1020 static const struct got_error *
1021 open_tree(struct got_tree_object **tree, struct got_repository *repo,
1022     struct got_object_id *id, int check_cache)
1023 {
1024 	const struct got_error *err = NULL;
1025 	struct got_packidx *packidx = NULL;
1026 	int idx;
1027 	char *path_packfile = NULL;
1028 
1029 	if (check_cache) {
1030 		*tree = got_repo_get_cached_tree(repo, id);
1031 		if (*tree != NULL) {
1032 			(*tree)->refcnt++;
1033 			return NULL;
1034 		}
1035 	} else
1036 		*tree = NULL;
1037 
1038 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1039 	if (err == NULL) {
1040 		struct got_pack *pack = NULL;
1041 
1042 		err = got_packidx_get_packfile_path(&path_packfile,
1043 		    packidx->path_packidx);
1044 		if (err)
1045 			return err;
1046 
1047 		pack = got_repo_get_cached_pack(repo, path_packfile);
1048 		if (pack == NULL) {
1049 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1050 			    packidx);
1051 			if (err)
1052 				goto done;
1053 		}
1054 		err = read_packed_tree_privsep(tree, pack,
1055 		    packidx, idx, id);
1056 	} else if (err->code == GOT_ERR_NO_OBJ) {
1057 		int fd;
1058 
1059 		err = got_object_open_loose_fd(&fd, id, repo);
1060 		if (err)
1061 			return err;
1062 		err = read_tree_privsep(tree, fd, id, repo);
1063 	}
1064 
1065 	if (err == NULL) {
1066 		(*tree)->refcnt++;
1067 		err = got_repo_cache_tree(repo, id, *tree);
1068 	}
1069 done:
1070 	free(path_packfile);
1071 	return err;
1072 }
1073 
1074 const struct got_error *
1075 got_object_open_as_tree(struct got_tree_object **tree,
1076     struct got_repository *repo, struct got_object_id *id)
1077 {
1078 	*tree = got_repo_get_cached_tree(repo, id);
1079 	if (*tree != NULL) {
1080 		(*tree)->refcnt++;
1081 		return NULL;
1082 	}
1083 
1084 	return open_tree(tree, repo, id, 0);
1085 }
1086 
1087 const struct got_error *
1088 got_object_tree_open(struct got_tree_object **tree,
1089     struct got_repository *repo, struct got_object *obj)
1090 {
1091 	return open_tree(tree, repo, got_object_get_id(obj), 1);
1092 }
1093 
1094 int
1095 got_object_tree_get_nentries(struct got_tree_object *tree)
1096 {
1097 	return tree->nentries;
1098 }
1099 
1100 struct got_tree_entry *
1101 got_object_tree_get_first_entry(struct got_tree_object *tree)
1102 {
1103 	return got_object_tree_get_entry(tree, 0);
1104 }
1105 
1106 struct got_tree_entry *
1107 got_object_tree_get_last_entry(struct got_tree_object *tree)
1108 {
1109 	return got_object_tree_get_entry(tree, tree->nentries - 1);
1110 }
1111 
1112 struct got_tree_entry *
1113 got_object_tree_get_entry(struct got_tree_object *tree, int i)
1114 {
1115 	if (i < 0 || i >= tree->nentries)
1116 		return NULL;
1117 	return &tree->entries[i];
1118 }
1119 
1120 mode_t
1121 got_tree_entry_get_mode(struct got_tree_entry *te)
1122 {
1123 	return te->mode;
1124 }
1125 
1126 const char *
1127 got_tree_entry_get_name(struct got_tree_entry *te)
1128 {
1129 	return &te->name[0];
1130 }
1131 
1132 struct got_object_id *
1133 got_tree_entry_get_id(struct got_tree_entry *te)
1134 {
1135 	return &te->id;
1136 }
1137 
1138 const struct got_error *
1139 got_object_blob_read_to_str(char **s, struct got_blob_object *blob)
1140 {
1141 	const struct got_error *err = NULL;
1142 	size_t len, totlen, hdrlen, offset;
1143 
1144 	*s = NULL;
1145 
1146 	hdrlen = got_object_blob_get_hdrlen(blob);
1147 	totlen = 0;
1148 	offset = 0;
1149 	do {
1150 		char *p;
1151 
1152 		err = got_object_blob_read_block(&len, blob);
1153 		if (err)
1154 			return err;
1155 
1156 		if (len == 0)
1157 			break;
1158 
1159 		totlen += len - hdrlen;
1160 		p = realloc(*s, totlen + 1);
1161 		if (p == NULL) {
1162 			err = got_error_from_errno("realloc");
1163 			free(*s);
1164 			*s = NULL;
1165 			return err;
1166 		}
1167 		*s = p;
1168 		/* Skip blob object header first time around. */
1169 		memcpy(*s + offset,
1170 		    got_object_blob_get_read_buf(blob) + hdrlen, len - hdrlen);
1171 		hdrlen = 0;
1172 		offset = totlen;
1173 	} while (len > 0);
1174 
1175 	(*s)[totlen] = '\0';
1176 	return NULL;
1177 }
1178 
1179 const struct got_error *
1180 got_tree_entry_get_symlink_target(char **link_target, struct got_tree_entry *te,
1181     struct got_repository *repo)
1182 {
1183 	const struct got_error *err = NULL;
1184 	struct got_blob_object *blob = NULL;
1185 
1186 	*link_target = NULL;
1187 
1188 	if (!got_object_tree_entry_is_symlink(te))
1189 		return got_error(GOT_ERR_TREE_ENTRY_TYPE);
1190 
1191 	err = got_object_open_as_blob(&blob, repo,
1192 	    got_tree_entry_get_id(te), PATH_MAX);
1193 	if (err)
1194 		return err;
1195 
1196 	err = got_object_blob_read_to_str(link_target, blob);
1197 	got_object_blob_close(blob);
1198 	if (err) {
1199 		free(*link_target);
1200 		*link_target = NULL;
1201 	}
1202 	return err;
1203 }
1204 
1205 int
1206 got_tree_entry_get_index(struct got_tree_entry *te)
1207 {
1208 	return te->idx;
1209 }
1210 
1211 struct got_tree_entry *
1212 got_tree_entry_get_next(struct got_tree_object *tree,
1213     struct got_tree_entry *te)
1214 {
1215 	return got_object_tree_get_entry(tree, te->idx + 1);
1216 }
1217 
1218 struct got_tree_entry *
1219 got_tree_entry_get_prev(struct got_tree_object *tree,
1220     struct got_tree_entry *te)
1221 {
1222 	return got_object_tree_get_entry(tree, te->idx - 1);
1223 }
1224 
1225 static const struct got_error *
1226 request_packed_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
1227     struct got_pack *pack, struct got_packidx *packidx, int idx,
1228     struct got_object_id *id)
1229 {
1230 	const struct got_error *err = NULL;
1231 	int outfd_child;
1232 	int basefd, accumfd; /* temporary files for delta application */
1233 
1234 	basefd = got_opentempfd();
1235 	if (basefd == -1)
1236 		return got_error_from_errno("got_opentempfd");
1237 	accumfd = got_opentempfd();
1238 	if (accumfd == -1)
1239 		return got_error_from_errno("got_opentempfd");
1240 
1241 	outfd_child = dup(outfd);
1242 	if (outfd_child == -1)
1243 		return got_error_from_errno("dup");
1244 
1245 	err = got_privsep_send_blob_req(pack->privsep_child->ibuf, -1, id, idx);
1246 	if (err)
1247 		return err;
1248 
1249 	err = got_privsep_send_blob_outfd(pack->privsep_child->ibuf,
1250 	    outfd_child);
1251 	if (err) {
1252 		close(basefd);
1253 		close(accumfd);
1254 		return err;
1255 	}
1256 
1257 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
1258 	    basefd);
1259 	if (err) {
1260 		close(accumfd);
1261 		return err;
1262 	}
1263 
1264 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
1265 	    accumfd);
1266 	if (err)
1267 		return err;
1268 
1269 	err = got_privsep_recv_blob(outbuf, size, hdrlen,
1270 	    pack->privsep_child->ibuf);
1271 	if (err)
1272 		return err;
1273 
1274 	if (lseek(outfd, SEEK_SET, 0) == -1)
1275 		err = got_error_from_errno("lseek");
1276 
1277 	return err;
1278 }
1279 
1280 static const struct got_error *
1281 read_packed_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1282     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
1283     struct got_object_id *id)
1284 {
1285 	const struct got_error *err = NULL;
1286 
1287 	if (pack->privsep_child == NULL) {
1288 		err = start_pack_privsep_child(pack, packidx);
1289 		if (err)
1290 			return err;
1291 	}
1292 
1293 	return request_packed_blob(outbuf, size, hdrlen, outfd, pack, packidx,
1294 	    idx, id);
1295 }
1296 
1297 static const struct got_error *
1298 request_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
1299     int infd, struct got_object_id *id, struct imsgbuf *ibuf)
1300 {
1301 	const struct got_error *err = NULL;
1302 	int outfd_child;
1303 
1304 	outfd_child = dup(outfd);
1305 	if (outfd_child == -1)
1306 		return got_error_from_errno("dup");
1307 
1308 	err = got_privsep_send_blob_req(ibuf, infd, id, -1);
1309 	if (err)
1310 		return err;
1311 
1312 	err = got_privsep_send_blob_outfd(ibuf, outfd_child);
1313 	if (err)
1314 		return err;
1315 
1316 	err = got_privsep_recv_blob(outbuf, size, hdrlen, ibuf);
1317 	if (err)
1318 		return err;
1319 
1320 	if (lseek(outfd, SEEK_SET, 0) == -1)
1321 		return got_error_from_errno("lseek");
1322 
1323 	return err;
1324 }
1325 
1326 static const struct got_error *
1327 read_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1328     int outfd, int infd, struct got_object_id *id, struct got_repository *repo)
1329 {
1330 	const struct got_error *err;
1331 	int imsg_fds[2];
1332 	pid_t pid;
1333 	struct imsgbuf *ibuf;
1334 
1335 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd != -1) {
1336 		ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf;
1337 		return request_blob(outbuf, size, hdrlen, outfd, infd, id,
1338 		    ibuf);
1339 	}
1340 
1341 	ibuf = calloc(1, sizeof(*ibuf));
1342 	if (ibuf == NULL)
1343 		return got_error_from_errno("calloc");
1344 
1345 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1346 		err = got_error_from_errno("socketpair");
1347 		free(ibuf);
1348 		return err;
1349 	}
1350 
1351 	pid = fork();
1352 	if (pid == -1) {
1353 		err = got_error_from_errno("fork");
1354 		free(ibuf);
1355 		return err;
1356 	}
1357 	else if (pid == 0) {
1358 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_BLOB,
1359 		    repo->path);
1360 		/* not reached */
1361 	}
1362 
1363 	if (close(imsg_fds[1]) == -1) {
1364 		err = got_error_from_errno("close");
1365 		free(ibuf);
1366 		return err;
1367 	}
1368 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd =
1369 	    imsg_fds[0];
1370 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].pid = pid;
1371 	imsg_init(ibuf, imsg_fds[0]);
1372 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf = ibuf;
1373 
1374 	return request_blob(outbuf, size, hdrlen, outfd, infd, id, ibuf);
1375 }
1376 
1377 static const struct got_error *
1378 open_blob(struct got_blob_object **blob, struct got_repository *repo,
1379     struct got_object_id *id, size_t blocksize)
1380 {
1381 	const struct got_error *err = NULL;
1382 	struct got_packidx *packidx = NULL;
1383 	int idx;
1384 	char *path_packfile = NULL;
1385 	uint8_t *outbuf;
1386 	int outfd;
1387 	size_t size, hdrlen;
1388 	struct stat sb;
1389 
1390 	*blob = calloc(1, sizeof(**blob));
1391 	if (*blob == NULL)
1392 		return got_error_from_errno("calloc");
1393 
1394 	outfd = got_opentempfd();
1395 	if (outfd == -1)
1396 		return got_error_from_errno("got_opentempfd");
1397 
1398 	(*blob)->read_buf = malloc(blocksize);
1399 	if ((*blob)->read_buf == NULL) {
1400 		err = got_error_from_errno("malloc");
1401 		goto done;
1402 	}
1403 
1404 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1405 	if (err == NULL) {
1406 		struct got_pack *pack = NULL;
1407 
1408 		err = got_packidx_get_packfile_path(&path_packfile,
1409 		    packidx->path_packidx);
1410 		if (err)
1411 			goto done;
1412 
1413 		pack = got_repo_get_cached_pack(repo, path_packfile);
1414 		if (pack == NULL) {
1415 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1416 			    packidx);
1417 			if (err)
1418 				goto done;
1419 		}
1420 		err = read_packed_blob_privsep(&outbuf, &size, &hdrlen, outfd,
1421 		    pack, packidx, idx, id);
1422 	} else if (err->code == GOT_ERR_NO_OBJ) {
1423 		int infd;
1424 
1425 		err = got_object_open_loose_fd(&infd, id, repo);
1426 		if (err)
1427 			goto done;
1428 		err = read_blob_privsep(&outbuf, &size, &hdrlen, outfd, infd,
1429 		    id, repo);
1430 	}
1431 	if (err)
1432 		goto done;
1433 
1434 	if (hdrlen > size) {
1435 		err = got_error(GOT_ERR_BAD_OBJ_HDR);
1436 		goto done;
1437 	}
1438 
1439 	if (outbuf) {
1440 		if (close(outfd) == -1 && err == NULL)
1441 			err = got_error_from_errno("close");
1442 		outfd = -1;
1443 		(*blob)->f = fmemopen(outbuf, size, "rb");
1444 		if ((*blob)->f == NULL) {
1445 			err = got_error_from_errno("fmemopen");
1446 			free(outbuf);
1447 			goto done;
1448 		}
1449 		(*blob)->data = outbuf;
1450 	} else {
1451 		if (fstat(outfd, &sb) == -1) {
1452 			err = got_error_from_errno("fstat");
1453 			goto done;
1454 		}
1455 
1456 		if (sb.st_size != size) {
1457 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1458 			goto done;
1459 		}
1460 
1461 		(*blob)->f = fdopen(outfd, "rb");
1462 		if ((*blob)->f == NULL) {
1463 			err = got_error_from_errno("fdopen");
1464 			close(outfd);
1465 			outfd = -1;
1466 			goto done;
1467 		}
1468 	}
1469 
1470 	(*blob)->hdrlen = hdrlen;
1471 	(*blob)->blocksize = blocksize;
1472 	memcpy(&(*blob)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
1473 
1474 done:
1475 	free(path_packfile);
1476 	if (err) {
1477 		if (*blob) {
1478 			got_object_blob_close(*blob);
1479 			*blob = NULL;
1480 		} else if (outfd != -1)
1481 			close(outfd);
1482 	}
1483 	return err;
1484 }
1485 
1486 const struct got_error *
1487 got_object_open_as_blob(struct got_blob_object **blob,
1488     struct got_repository *repo, struct got_object_id *id,
1489     size_t blocksize)
1490 {
1491 	return open_blob(blob, repo, id, blocksize);
1492 }
1493 
1494 const struct got_error *
1495 got_object_blob_open(struct got_blob_object **blob,
1496     struct got_repository *repo, struct got_object *obj, size_t blocksize)
1497 {
1498 	return open_blob(blob, repo, got_object_get_id(obj), blocksize);
1499 }
1500 
1501 const struct got_error *
1502 got_object_blob_close(struct got_blob_object *blob)
1503 {
1504 	const struct got_error *err = NULL;
1505 	free(blob->read_buf);
1506 	if (blob->f && fclose(blob->f) == EOF)
1507 		err = got_error_from_errno("fclose");
1508 	free(blob->data);
1509 	free(blob);
1510 	return err;
1511 }
1512 
1513 void
1514 got_object_blob_rewind(struct got_blob_object *blob)
1515 {
1516 	if (blob->f)
1517 		rewind(blob->f);
1518 }
1519 
1520 char *
1521 got_object_blob_id_str(struct got_blob_object *blob, char *buf, size_t size)
1522 {
1523 	return got_sha1_digest_to_str(blob->id.sha1, buf, size);
1524 }
1525 
1526 size_t
1527 got_object_blob_get_hdrlen(struct got_blob_object *blob)
1528 {
1529 	return blob->hdrlen;
1530 }
1531 
1532 const uint8_t *
1533 got_object_blob_get_read_buf(struct got_blob_object *blob)
1534 {
1535 	return blob->read_buf;
1536 }
1537 
1538 const struct got_error *
1539 got_object_blob_read_block(size_t *outlenp, struct got_blob_object *blob)
1540 {
1541 	size_t n;
1542 
1543 	n = fread(blob->read_buf, 1, blob->blocksize, blob->f);
1544 	if (n == 0 && ferror(blob->f))
1545 		return got_ferror(blob->f, GOT_ERR_IO);
1546 	*outlenp = n;
1547 	return NULL;
1548 }
1549 
1550 const struct got_error *
1551 got_object_blob_dump_to_file(off_t *filesize, int *nlines,
1552     off_t **line_offsets, FILE *outfile, struct got_blob_object *blob)
1553 {
1554 	const struct got_error *err = NULL;
1555 	size_t n, len, hdrlen;
1556 	const uint8_t *buf;
1557 	int i;
1558 	const int alloc_chunksz = 512;
1559 	size_t nalloc = 0;
1560 	off_t off = 0, total_len = 0;
1561 
1562 	if (line_offsets)
1563 		*line_offsets = NULL;
1564 	if (filesize)
1565 		*filesize = 0;
1566 	if (nlines)
1567 		*nlines = 0;
1568 
1569 	hdrlen = got_object_blob_get_hdrlen(blob);
1570 	do {
1571 		err = got_object_blob_read_block(&len, blob);
1572 		if (err)
1573 			return err;
1574 		if (len == 0)
1575 			break;
1576 		buf = got_object_blob_get_read_buf(blob);
1577 		i = hdrlen;
1578 		if (nlines) {
1579 			if (line_offsets && *line_offsets == NULL) {
1580 				/* Have some data but perhaps no '\n'. */
1581 				*nlines = 1;
1582 				nalloc = alloc_chunksz;
1583 				*line_offsets = calloc(nalloc,
1584 				    sizeof(**line_offsets));
1585 				if (*line_offsets == NULL)
1586 					return got_error_from_errno("calloc");
1587 
1588 				/* Skip forward over end of first line. */
1589 				while (i < len) {
1590 					if (buf[i] == '\n')
1591 						break;
1592 					i++;
1593 				}
1594 			}
1595 			/* Scan '\n' offsets in remaining chunk of data. */
1596 			while (i < len) {
1597 				if (buf[i] != '\n') {
1598 					i++;
1599 					continue;
1600 				}
1601 				(*nlines)++;
1602 				if (line_offsets && nalloc < *nlines) {
1603 					size_t n = *nlines + alloc_chunksz;
1604 					off_t *o = recallocarray(*line_offsets,
1605 					    nalloc, n, sizeof(**line_offsets));
1606 					if (o == NULL) {
1607 						free(*line_offsets);
1608 						*line_offsets = NULL;
1609 						return got_error_from_errno(
1610 						    "recallocarray");
1611 					}
1612 					*line_offsets = o;
1613 					nalloc = n;
1614 				}
1615 				if (line_offsets) {
1616 					off = total_len + i - hdrlen + 1;
1617 					(*line_offsets)[*nlines - 1] = off;
1618 				}
1619 				i++;
1620 			}
1621 		}
1622 		/* Skip blob object header first time around. */
1623 		n = fwrite(buf + hdrlen, 1, len - hdrlen, outfile);
1624 		if (n != len - hdrlen)
1625 			return got_ferror(outfile, GOT_ERR_IO);
1626 		total_len += len - hdrlen;
1627 		hdrlen = 0;
1628 	} while (len != 0);
1629 
1630 	if (fflush(outfile) != 0)
1631 		return got_error_from_errno("fflush");
1632 	rewind(outfile);
1633 
1634 	if (filesize)
1635 		*filesize = total_len;
1636 
1637 	return NULL;
1638 }
1639 
1640 static const struct got_error *
1641 request_packed_tag(struct got_tag_object **tag, struct got_pack *pack,
1642     int pack_idx, struct got_object_id *id)
1643 {
1644 	const struct got_error *err = NULL;
1645 
1646 	err = got_privsep_send_tag_req(pack->privsep_child->ibuf, -1, id,
1647 	    pack_idx);
1648 	if (err)
1649 		return err;
1650 
1651 	return got_privsep_recv_tag(tag, pack->privsep_child->ibuf);
1652 }
1653 
1654 static const struct got_error *
1655 read_packed_tag_privsep(struct got_tag_object **tag,
1656     struct got_pack *pack, struct got_packidx *packidx, int idx,
1657     struct got_object_id *id)
1658 {
1659 	const struct got_error *err = NULL;
1660 
1661 	if (pack->privsep_child)
1662 		return request_packed_tag(tag, pack, idx, id);
1663 
1664 	err = start_pack_privsep_child(pack, packidx);
1665 	if (err)
1666 		return err;
1667 
1668 	return request_packed_tag(tag, pack, idx, id);
1669 }
1670 
1671 static const struct got_error *
1672 request_tag(struct got_tag_object **tag, struct got_repository *repo,
1673     int fd, struct got_object_id *id)
1674 {
1675 	const struct got_error *err = NULL;
1676 	struct imsgbuf *ibuf;
1677 
1678 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf;
1679 
1680 	err = got_privsep_send_tag_req(ibuf, fd, id, -1);
1681 	if (err)
1682 		return err;
1683 
1684 	return got_privsep_recv_tag(tag, ibuf);
1685 }
1686 
1687 static const struct got_error *
1688 read_tag_privsep(struct got_tag_object **tag, int obj_fd,
1689     struct got_object_id *id, struct got_repository *repo)
1690 {
1691 	const struct got_error *err;
1692 	int imsg_fds[2];
1693 	pid_t pid;
1694 	struct imsgbuf *ibuf;
1695 
1696 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd != -1)
1697 		return request_tag(tag, repo, obj_fd, id);
1698 
1699 	ibuf = calloc(1, sizeof(*ibuf));
1700 	if (ibuf == NULL)
1701 		return got_error_from_errno("calloc");
1702 
1703 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1704 		err = got_error_from_errno("socketpair");
1705 		free(ibuf);
1706 		return err;
1707 	}
1708 
1709 	pid = fork();
1710 	if (pid == -1) {
1711 		err = got_error_from_errno("fork");
1712 		free(ibuf);
1713 		return err;
1714 	}
1715 	else if (pid == 0) {
1716 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TAG,
1717 		    repo->path);
1718 		/* not reached */
1719 	}
1720 
1721 	if (close(imsg_fds[1]) == -1) {
1722 		err = got_error_from_errno("close");
1723 		free(ibuf);
1724 		return err;
1725 	}
1726 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd =
1727 	    imsg_fds[0];
1728 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].pid = pid;
1729 	imsg_init(ibuf, imsg_fds[0]);
1730 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf = ibuf;
1731 
1732 	return request_tag(tag, repo, obj_fd, id);
1733 }
1734 
1735 static const struct got_error *
1736 open_tag(struct got_tag_object **tag, struct got_repository *repo,
1737     struct got_object_id *id, int check_cache)
1738 {
1739 	const struct got_error *err = NULL;
1740 	struct got_packidx *packidx = NULL;
1741 	int idx;
1742 	char *path_packfile = NULL;
1743 	struct got_object *obj = NULL;
1744 	int obj_type = GOT_OBJ_TYPE_ANY;
1745 
1746 	if (check_cache) {
1747 		*tag = got_repo_get_cached_tag(repo, id);
1748 		if (*tag != NULL) {
1749 			(*tag)->refcnt++;
1750 			return NULL;
1751 		}
1752 	} else
1753 		*tag = NULL;
1754 
1755 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1756 	if (err == NULL) {
1757 		struct got_pack *pack = NULL;
1758 
1759 		err = got_packidx_get_packfile_path(&path_packfile,
1760 		    packidx->path_packidx);
1761 		if (err)
1762 			return err;
1763 
1764 		pack = got_repo_get_cached_pack(repo, path_packfile);
1765 		if (pack == NULL) {
1766 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1767 			    packidx);
1768 			if (err)
1769 				goto done;
1770 		}
1771 
1772 		/* Beware of "lightweight" tags: Check object type first. */
1773 		err = read_packed_object_privsep(&obj, repo, pack, packidx,
1774 		    idx, id);
1775 		if (err)
1776 			goto done;
1777 		obj_type = obj->type;
1778 		got_object_close(obj);
1779 		if (obj_type != GOT_OBJ_TYPE_TAG) {
1780 			err = got_error(GOT_ERR_OBJ_TYPE);
1781 			goto done;
1782 		}
1783 		err = read_packed_tag_privsep(tag, pack, packidx, idx, id);
1784 	} else if (err->code == GOT_ERR_NO_OBJ) {
1785 		int fd;
1786 
1787 		err = got_object_open_loose_fd(&fd, id, repo);
1788 		if (err)
1789 			return err;
1790 		err = got_object_read_header_privsep(&obj, id, repo, fd);
1791 		if (err)
1792 			return err;
1793 		obj_type = obj->type;
1794 		got_object_close(obj);
1795 		if (obj_type != GOT_OBJ_TYPE_TAG)
1796 			return got_error(GOT_ERR_OBJ_TYPE);
1797 
1798 		err = got_object_open_loose_fd(&fd, id, repo);
1799 		if (err)
1800 			return err;
1801 		err = read_tag_privsep(tag, fd, id, repo);
1802 	}
1803 
1804 	if (err == NULL) {
1805 		(*tag)->refcnt++;
1806 		err = got_repo_cache_tag(repo, id, *tag);
1807 	}
1808 done:
1809 	free(path_packfile);
1810 	return err;
1811 }
1812 
1813 const struct got_error *
1814 got_object_open_as_tag(struct got_tag_object **tag,
1815     struct got_repository *repo, struct got_object_id *id)
1816 {
1817 	*tag = got_repo_get_cached_tag(repo, id);
1818 	if (*tag != NULL) {
1819 		(*tag)->refcnt++;
1820 		return NULL;
1821 	}
1822 
1823 	return open_tag(tag, repo, id, 0);
1824 }
1825 
1826 const struct got_error *
1827 got_object_tag_open(struct got_tag_object **tag,
1828     struct got_repository *repo, struct got_object *obj)
1829 {
1830 	return open_tag(tag, repo, got_object_get_id(obj), 1);
1831 }
1832 
1833 const char *
1834 got_object_tag_get_name(struct got_tag_object *tag)
1835 {
1836 	return tag->tag;
1837 }
1838 
1839 int
1840 got_object_tag_get_object_type(struct got_tag_object *tag)
1841 {
1842 	return tag->obj_type;
1843 }
1844 
1845 struct got_object_id *
1846 got_object_tag_get_object_id(struct got_tag_object *tag)
1847 {
1848 	return &tag->id;
1849 }
1850 
1851 time_t
1852 got_object_tag_get_tagger_time(struct got_tag_object *tag)
1853 {
1854 	return tag->tagger_time;
1855 }
1856 
1857 time_t
1858 got_object_tag_get_tagger_gmtoff(struct got_tag_object *tag)
1859 {
1860 	return tag->tagger_gmtoff;
1861 }
1862 
1863 const char *
1864 got_object_tag_get_tagger(struct got_tag_object *tag)
1865 {
1866 	return tag->tagger;
1867 }
1868 
1869 const char *
1870 got_object_tag_get_message(struct got_tag_object *tag)
1871 {
1872 	return tag->tagmsg;
1873 }
1874 
1875 static struct got_tree_entry *
1876 find_entry_by_name(struct got_tree_object *tree, const char *name, size_t len)
1877 {
1878 	int i;
1879 
1880 	/* Note that tree entries are sorted in strncmp() order. */
1881 	for (i = 0; i < tree->nentries; i++) {
1882 		struct got_tree_entry *te = &tree->entries[i];
1883 		int cmp = strncmp(te->name, name, len);
1884 		if (cmp < 0)
1885 			continue;
1886 		if (cmp > 0)
1887 			break;
1888 		if (te->name[len] == '\0')
1889 			return te;
1890 	}
1891 	return NULL;
1892 }
1893 
1894 struct got_tree_entry *
1895 got_object_tree_find_entry(struct got_tree_object *tree, const char *name)
1896 {
1897 	return find_entry_by_name(tree, name, strlen(name));
1898 }
1899 
1900 const struct got_error *
1901 got_object_tree_find_path(struct got_object_id **id, mode_t *mode,
1902     struct got_repository *repo, struct got_tree_object *tree,
1903     const char *path)
1904 {
1905 	const struct got_error *err = NULL;
1906 	struct got_tree_object *subtree = NULL;
1907 	struct got_tree_entry *te = NULL;
1908 	const char *seg, *s;
1909 	size_t seglen;
1910 
1911 	*id = NULL;
1912 
1913 	s = path;
1914 	while (s[0] == '/')
1915 		s++;
1916 	seg = s;
1917 	seglen = 0;
1918 	subtree = tree;
1919 	while (*s) {
1920 		struct got_tree_object *next_tree;
1921 
1922 		if (*s != '/') {
1923 			s++;
1924 			seglen++;
1925 			if (*s)
1926 				continue;
1927 		}
1928 
1929 		te = find_entry_by_name(subtree, seg, seglen);
1930 		if (te == NULL) {
1931 			err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
1932 			goto done;
1933 		}
1934 
1935 		if (*s == '\0')
1936 			break;
1937 
1938 		seg = s + 1;
1939 		seglen = 0;
1940 		s++;
1941 		if (*s) {
1942 			err = got_object_open_as_tree(&next_tree, repo,
1943 			    &te->id);
1944 			te = NULL;
1945 			if (err)
1946 				goto done;
1947 			if (subtree != tree)
1948 				got_object_tree_close(subtree);
1949 			subtree = next_tree;
1950 		}
1951 	}
1952 
1953 	if (te) {
1954 		*id = got_object_id_dup(&te->id);
1955 		if (*id == NULL)
1956 			return got_error_from_errno("got_object_id_dup");
1957 		if (mode)
1958 			*mode = te->mode;
1959 	} else
1960 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
1961 done:
1962 	if (subtree && subtree != tree)
1963 		got_object_tree_close(subtree);
1964 	return err;
1965 }
1966 const struct got_error *
1967 got_object_id_by_path(struct got_object_id **id, struct got_repository *repo,
1968     struct got_object_id *commit_id, const char *path)
1969 {
1970 	const struct got_error *err = NULL;
1971 	struct got_commit_object *commit = NULL;
1972 	struct got_tree_object *tree = NULL;
1973 
1974 	*id = NULL;
1975 
1976 	err = got_object_open_as_commit(&commit, repo, commit_id);
1977 	if (err)
1978 		goto done;
1979 
1980 	/* Handle opening of root of commit's tree. */
1981 	if (got_path_is_root_dir(path)) {
1982 		*id = got_object_id_dup(commit->tree_id);
1983 		if (*id == NULL)
1984 			err = got_error_from_errno("got_object_id_dup");
1985 	} else {
1986 		err = got_object_open_as_tree(&tree, repo, commit->tree_id);
1987 		if (err)
1988 			goto done;
1989 		err = got_object_tree_find_path(id, NULL, repo, tree, path);
1990 	}
1991 done:
1992 	if (commit)
1993 		got_object_commit_close(commit);
1994 	if (tree)
1995 		got_object_tree_close(tree);
1996 	return err;
1997 }
1998 
1999 /*
2000  * Normalize file mode bits to avoid false positive tree entry differences
2001  * in case tree entries have unexpected mode bits set.
2002  */
2003 static mode_t
2004 normalize_mode_for_comparison(mode_t mode)
2005 {
2006 	/*
2007 	 * For directories, the only relevant bit is the IFDIR bit.
2008 	 * This allows us to detect paths changing from a directory
2009 	 * to a file and vice versa.
2010 	 */
2011 	if (S_ISDIR(mode))
2012 		return mode & S_IFDIR;
2013 
2014 	/*
2015 	 * For symlinks, the only relevant bit is the IFLNK bit.
2016 	 * This allows us to detect paths changing from a symlinks
2017 	 * to a file or directory and vice versa.
2018 	 */
2019 	if (S_ISLNK(mode))
2020 		return mode & S_IFLNK;
2021 
2022 	/* For files, the only change we care about is the executable bit. */
2023 	return mode & S_IXUSR;
2024 }
2025 
2026 const struct got_error *
2027 got_object_tree_path_changed(int *changed,
2028     struct got_tree_object *tree01, struct got_tree_object *tree02,
2029     const char *path, struct got_repository *repo)
2030 {
2031 	const struct got_error *err = NULL;
2032 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
2033 	struct got_tree_entry *te1 = NULL, *te2 = NULL;
2034 	const char *seg, *s;
2035 	size_t seglen;
2036 
2037 	*changed = 0;
2038 
2039 	/* We not do support comparing the root path. */
2040 	if (got_path_is_root_dir(path))
2041 		return got_error_path(path, GOT_ERR_BAD_PATH);
2042 
2043 	tree1 = tree01;
2044 	tree2 = tree02;
2045 	s = path;
2046 	while (*s == '/')
2047 		s++;
2048 	seg = s;
2049 	seglen = 0;
2050 	while (*s) {
2051 		struct got_tree_object *next_tree1, *next_tree2;
2052 		mode_t mode1, mode2;
2053 
2054 		if (*s != '/') {
2055 			s++;
2056 			seglen++;
2057 			if (*s)
2058 				continue;
2059 		}
2060 
2061 		te1 = find_entry_by_name(tree1, seg, seglen);
2062 		if (te1 == NULL) {
2063 			err = got_error(GOT_ERR_NO_OBJ);
2064 			goto done;
2065 		}
2066 
2067 		if (tree2)
2068 			te2 = find_entry_by_name(tree2, seg, seglen);
2069 
2070 		if (te2) {
2071 			mode1 = normalize_mode_for_comparison(te1->mode);
2072 			mode2 = normalize_mode_for_comparison(te2->mode);
2073 			if (mode1 != mode2) {
2074 				*changed = 1;
2075 				goto done;
2076 			}
2077 
2078 			if (got_object_id_cmp(&te1->id, &te2->id) == 0) {
2079 				*changed = 0;
2080 				goto done;
2081 			}
2082 		}
2083 
2084 		if (*s == '\0') { /* final path element */
2085 			*changed = 1;
2086 			goto done;
2087 		}
2088 
2089 		seg = s + 1;
2090 		s++;
2091 		seglen = 0;
2092 		if (*s) {
2093 			err = got_object_open_as_tree(&next_tree1, repo,
2094 			    &te1->id);
2095 			te1 = NULL;
2096 			if (err)
2097 				goto done;
2098 			if (tree1 != tree01)
2099 				got_object_tree_close(tree1);
2100 			tree1 = next_tree1;
2101 
2102 			if (te2) {
2103 				err = got_object_open_as_tree(&next_tree2, repo,
2104 				    &te2->id);
2105 				te2 = NULL;
2106 				if (err)
2107 					goto done;
2108 				if (tree2 != tree02)
2109 					got_object_tree_close(tree2);
2110 				tree2 = next_tree2;
2111 			} else if (tree2) {
2112 				if (tree2 != tree02)
2113 					got_object_tree_close(tree2);
2114 				tree2 = NULL;
2115 			}
2116 		}
2117 	}
2118 done:
2119 	if (tree1 && tree1 != tree01)
2120 		got_object_tree_close(tree1);
2121 	if (tree2 && tree2 != tree02)
2122 		got_object_tree_close(tree2);
2123 	return err;
2124 }
2125 
2126 const struct got_error *
2127 got_object_tree_entry_dup(struct got_tree_entry **new_te,
2128     struct got_tree_entry *te)
2129 {
2130 	const struct got_error *err = NULL;
2131 
2132 	*new_te = calloc(1, sizeof(**new_te));
2133 	if (*new_te == NULL)
2134 		return got_error_from_errno("calloc");
2135 
2136 	(*new_te)->mode = te->mode;
2137 	memcpy((*new_te)->name, te->name, sizeof((*new_te)->name));
2138 	memcpy(&(*new_te)->id, &te->id, sizeof((*new_te)->id));
2139 	return err;
2140 }
2141 
2142 int
2143 got_object_tree_entry_is_submodule(struct got_tree_entry *te)
2144 {
2145 	return (te->mode & S_IFMT) == (S_IFDIR | S_IFLNK);
2146 }
2147 
2148 int
2149 got_object_tree_entry_is_symlink(struct got_tree_entry *te)
2150 {
2151 	/* S_IFDIR check avoids confusing symlinks with submodules. */
2152 	return ((te->mode & (S_IFDIR | S_IFLNK)) == S_IFLNK);
2153 }
2154 
2155 static const struct got_error *
2156 resolve_symlink(char **link_target, const char *path,
2157     struct got_object_id *commit_id, struct got_repository *repo)
2158 {
2159 	const struct got_error *err = NULL;
2160 	char buf[PATH_MAX];
2161 	char *name, *parent_path = NULL;
2162 	struct got_object_id *tree_obj_id = NULL;
2163 	struct got_tree_object *tree = NULL;
2164 	struct got_tree_entry *te = NULL;
2165 
2166 	*link_target = NULL;
2167 
2168 	if (strlcpy(buf, path, sizeof(buf)) >= sizeof(buf))
2169 		return got_error(GOT_ERR_NO_SPACE);
2170 
2171 	name = basename(buf);
2172 	if (name == NULL)
2173 		return got_error_from_errno2("basename", path);
2174 
2175 	err = got_path_dirname(&parent_path, path);
2176 	if (err)
2177 		return err;
2178 
2179 	err = got_object_id_by_path(&tree_obj_id, repo, commit_id,
2180 	    parent_path);
2181 	if (err) {
2182 		if (err->code == GOT_ERR_NO_TREE_ENTRY) {
2183 			/* Display the complete path in error message. */
2184 			err = got_error_path(path, err->code);
2185 		}
2186 		goto done;
2187 	}
2188 
2189 	err = got_object_open_as_tree(&tree, repo, tree_obj_id);
2190 	if (err)
2191 		goto done;
2192 
2193 	te = got_object_tree_find_entry(tree, name);
2194 	if (te == NULL) {
2195 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
2196 		goto done;
2197 	}
2198 
2199 	if (got_object_tree_entry_is_symlink(te)) {
2200 		err = got_tree_entry_get_symlink_target(link_target, te, repo);
2201 		if (err)
2202 			goto done;
2203 		if (!got_path_is_absolute(*link_target)) {
2204 			char *abspath;
2205 			if (asprintf(&abspath, "%s/%s", parent_path,
2206 			    *link_target) == -1) {
2207 				err = got_error_from_errno("asprintf");
2208 				goto done;
2209 			}
2210 			free(*link_target);
2211 			*link_target = malloc(PATH_MAX);
2212 			if (*link_target == NULL) {
2213 				err = got_error_from_errno("malloc");
2214 				goto done;
2215 			}
2216 			err = got_canonpath(abspath, *link_target, PATH_MAX);
2217 			free(abspath);
2218 			if (err)
2219 				goto done;
2220 		}
2221 	}
2222 done:
2223 	free(tree_obj_id);
2224 	if (tree)
2225 		got_object_tree_close(tree);
2226 	if (err) {
2227 		free(*link_target);
2228 		*link_target = NULL;
2229 	}
2230 	return err;
2231 }
2232 
2233 const struct got_error *
2234 got_object_resolve_symlinks(char **link_target, const char *path,
2235     struct got_object_id *commit_id, struct got_repository *repo)
2236 {
2237 	const struct got_error *err = NULL;
2238 	char *next_target = NULL;
2239 	int max_recursion = 40; /* matches Git */
2240 
2241 	*link_target = NULL;
2242 
2243 	do {
2244 		err = resolve_symlink(&next_target,
2245 		    *link_target ? *link_target : path, commit_id, repo);
2246 		if (err)
2247 			break;
2248 		if (next_target) {
2249 			free(*link_target);
2250 			if (--max_recursion == 0) {
2251 				err = got_error_path(path, GOT_ERR_RECURSION);
2252 				*link_target = NULL;
2253 				break;
2254 			}
2255 			*link_target = next_target;
2256 		}
2257 	} while (next_target);
2258 
2259 	return err;
2260 }
2261 
2262 const struct got_error *
2263 got_traverse_packed_commits(struct got_object_id_queue *traversed_commits,
2264     struct got_object_id *commit_id, const char *path,
2265     struct got_repository *repo)
2266 {
2267 	const struct got_error *err = NULL;
2268 	struct got_pack *pack = NULL;
2269 	struct got_packidx *packidx = NULL;
2270 	char *path_packfile = NULL;
2271 	struct got_commit_object *changed_commit = NULL;
2272 	struct got_object_id *changed_commit_id = NULL;
2273 	int idx;
2274 
2275 	err = got_repo_search_packidx(&packidx, &idx, repo, commit_id);
2276 	if (err) {
2277 		if (err->code != GOT_ERR_NO_OBJ)
2278 			return err;
2279 		return NULL;
2280 	}
2281 
2282 	err = got_packidx_get_packfile_path(&path_packfile,
2283 	    packidx->path_packidx);
2284 	if (err)
2285 		return err;
2286 
2287 	pack = got_repo_get_cached_pack(repo, path_packfile);
2288 	if (pack == NULL) {
2289 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
2290 		if (err)
2291 			goto done;
2292 	}
2293 
2294 	if (pack->privsep_child == NULL) {
2295 		err = start_pack_privsep_child(pack, packidx);
2296 		if (err)
2297 			goto done;
2298 	}
2299 
2300 	err = got_privsep_send_commit_traversal_request(
2301 	    pack->privsep_child->ibuf, commit_id, idx, path);
2302 	if (err)
2303 		goto done;
2304 
2305 	err = got_privsep_recv_traversed_commits(&changed_commit,
2306 	    &changed_commit_id, traversed_commits, pack->privsep_child->ibuf);
2307 	if (err)
2308 		goto done;
2309 
2310 	if (changed_commit) {
2311 		/*
2312 		 * Cache the commit in which the path was changed.
2313 		 * This commit might be opened again soon.
2314 		 */
2315 		changed_commit->refcnt++;
2316 		err = got_repo_cache_commit(repo, changed_commit_id,
2317 		    changed_commit);
2318 		got_object_commit_close(changed_commit);
2319 	}
2320 done:
2321 	free(path_packfile);
2322 	free(changed_commit_id);
2323 	return err;
2324 }