1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <sys/stat.h>
19 #include <sys/queue.h>
20 #include <sys/uio.h>
21 #include <sys/socket.h>
22 #include <sys/wait.h>
23 #include <sys/resource.h>
24 
25 #include <errno.h>
26 #include <fcntl.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <stdint.h>
31 #include <sha1.h>
32 #include <unistd.h>
33 #include <zlib.h>
34 #include <ctype.h>
35 #include <libgen.h>
36 #include <limits.h>
37 #include <imsg.h>
38 #include <time.h>
39 
40 #include "got_error.h"
41 #include "got_object.h"
42 #include "got_repository.h"
43 #include "got_opentemp.h"
44 #include "got_path.h"
45 
46 #include "got_lib_sha1.h"
47 #include "got_lib_delta.h"
48 #include "got_lib_inflate.h"
49 #include "got_lib_object.h"
50 #include "got_lib_privsep.h"
51 #include "got_lib_object_idcache.h"
52 #include "got_lib_object_cache.h"
53 #include "got_lib_object_parse.h"
54 #include "got_lib_pack.h"
55 #include "got_lib_repository.h"
56 
57 #ifndef MIN
58 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
59 #endif
60 
61 struct got_object_id *
62 got_object_get_id(struct got_object *obj)
63 {
64 	return &obj->id;
65 }
66 
67 const struct got_error *
68 got_object_get_id_str(char **outbuf, struct got_object *obj)
69 {
70 	return got_object_id_str(outbuf, &obj->id);
71 }
72 
73 const struct got_error *
74 got_object_get_type(int *type, struct got_repository *repo,
75     struct got_object_id *id)
76 {
77 	const struct got_error *err = NULL;
78 	struct got_object *obj;
79 
80 	err = got_object_open(&obj, repo, id);
81 	if (err)
82 		return err;
83 
84 	switch (obj->type) {
85 	case GOT_OBJ_TYPE_COMMIT:
86 	case GOT_OBJ_TYPE_TREE:
87 	case GOT_OBJ_TYPE_BLOB:
88 	case GOT_OBJ_TYPE_TAG:
89 		*type = obj->type;
90 		break;
91 	default:
92 		err = got_error(GOT_ERR_OBJ_TYPE);
93 		break;
94 	}
95 
96 	got_object_close(obj);
97 	return err;
98 }
99 
100 const struct got_error *
101 got_object_get_path(char **path, struct got_object_id *id,
102     struct got_repository *repo)
103 {
104 	const struct got_error *err = NULL;
105 	char *hex = NULL;
106 	char *path_objects;
107 
108 	*path = NULL;
109 
110 	path_objects = got_repo_get_path_objects(repo);
111 	if (path_objects == NULL)
112 		return got_error_from_errno("got_repo_get_path_objects");
113 
114 	err = got_object_id_str(&hex, id);
115 	if (err)
116 		goto done;
117 
118 	if (asprintf(path, "%s/%.2x/%s", path_objects,
119 	    id->sha1[0], hex + 2) == -1)
120 		err = got_error_from_errno("asprintf");
121 
122 done:
123 	free(hex);
124 	free(path_objects);
125 	return err;
126 }
127 
128 const struct got_error *
129 got_object_open_loose_fd(int *fd, struct got_object_id *id,
130     struct got_repository *repo)
131 {
132 	const struct got_error *err = NULL;
133 	char *path;
134 
135 	err = got_object_get_path(&path, id, repo);
136 	if (err)
137 		return err;
138 	*fd = open(path, O_RDONLY | O_NOFOLLOW);
139 	if (*fd == -1) {
140 		err = got_error_from_errno2("open", path);
141 		goto done;
142 	}
143 done:
144 	free(path);
145 	return err;
146 }
147 
148 static const struct got_error *
149 request_packed_object(struct got_object **obj, struct got_pack *pack, int idx,
150     struct got_object_id *id)
151 {
152 	const struct got_error *err = NULL;
153 	struct imsgbuf *ibuf = pack->privsep_child->ibuf;
154 
155 	err = got_privsep_send_packed_obj_req(ibuf, idx, id);
156 	if (err)
157 		return err;
158 
159 	err = got_privsep_recv_obj(obj, ibuf);
160 	if (err)
161 		return err;
162 
163 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
164 
165 	return NULL;
166 }
167 
168 static const struct got_error *
169 request_packed_object_raw(uint8_t **outbuf, off_t *size, size_t *hdrlen,
170     int outfd, struct got_pack *pack, int idx, struct got_object_id *id)
171 {
172 	const struct got_error *err = NULL;
173 	struct imsgbuf *ibuf = pack->privsep_child->ibuf;
174 	int outfd_child;
175 	int basefd, accumfd; /* temporary files for delta application */
176 
177 	basefd = got_opentempfd();
178 	if (basefd == -1)
179 		return got_error_from_errno("got_opentempfd");
180 
181 	accumfd = got_opentempfd();
182 	if (accumfd == -1) {
183 		close(basefd);
184 		return got_error_from_errno("got_opentempfd");
185 	}
186 
187 	outfd_child = dup(outfd);
188 	if (outfd_child == -1) {
189 		err = got_error_from_errno("dup");
190 		close(basefd);
191 		close(accumfd);
192 		return err;
193 	}
194 
195 	err = got_privsep_send_packed_raw_obj_req(ibuf, idx, id);
196 	if (err) {
197 		close(basefd);
198 		close(accumfd);
199 		close(outfd_child);
200 		return err;
201 	}
202 
203 	err = got_privsep_send_raw_obj_outfd(ibuf, outfd_child);
204 	if (err) {
205 		close(basefd);
206 		close(accumfd);
207 		return err;
208 	}
209 
210 
211 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
212 	    basefd);
213 	if (err) {
214 		close(accumfd);
215 		return err;
216 	}
217 
218 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
219 	    accumfd);
220 	if (err)
221 		return err;
222 
223 	err = got_privsep_recv_raw_obj(outbuf, size, hdrlen, ibuf);
224 	if (err)
225 		return err;
226 
227 	return NULL;
228 }
229 
230 static void
231 set_max_datasize(void)
232 {
233 	struct rlimit rl;
234 
235 	if (getrlimit(RLIMIT_DATA, &rl) != 0)
236 		return;
237 
238 	rl.rlim_cur = rl.rlim_max;
239 	setrlimit(RLIMIT_DATA, &rl);
240 }
241 
242 static const struct got_error *
243 start_pack_privsep_child(struct got_pack *pack, struct got_packidx *packidx)
244 {
245 	const struct got_error *err = NULL;
246 	int imsg_fds[2];
247 	pid_t pid;
248 	struct imsgbuf *ibuf;
249 
250 	ibuf = calloc(1, sizeof(*ibuf));
251 	if (ibuf == NULL)
252 		return got_error_from_errno("calloc");
253 
254 	pack->privsep_child = calloc(1, sizeof(*pack->privsep_child));
255 	if (pack->privsep_child == NULL) {
256 		err = got_error_from_errno("calloc");
257 		free(ibuf);
258 		return err;
259 	}
260 
261 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
262 		err = got_error_from_errno("socketpair");
263 		goto done;
264 	}
265 
266 	pid = fork();
267 	if (pid == -1) {
268 		err = got_error_from_errno("fork");
269 		goto done;
270 	} else if (pid == 0) {
271 		set_max_datasize();
272 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PACK,
273 		    pack->path_packfile);
274 		/* not reached */
275 	}
276 
277 	if (close(imsg_fds[1]) == -1)
278 		return got_error_from_errno("close");
279 	pack->privsep_child->imsg_fd = imsg_fds[0];
280 	pack->privsep_child->pid = pid;
281 	imsg_init(ibuf, imsg_fds[0]);
282 	pack->privsep_child->ibuf = ibuf;
283 
284 	err = got_privsep_init_pack_child(ibuf, pack, packidx);
285 	if (err) {
286 		const struct got_error *child_err;
287 		err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
288 		child_err = got_privsep_wait_for_child(
289 		    pack->privsep_child->pid);
290 		if (child_err && err == NULL)
291 			err = child_err;
292 	}
293 done:
294 	if (err) {
295 		free(ibuf);
296 		free(pack->privsep_child);
297 		pack->privsep_child = NULL;
298 	}
299 	return err;
300 }
301 
302 static const struct got_error *
303 read_packed_object_privsep(struct got_object **obj,
304     struct got_repository *repo, struct got_pack *pack,
305     struct got_packidx *packidx, int idx, struct got_object_id *id)
306 {
307 	const struct got_error *err = NULL;
308 
309 	if (pack->privsep_child == NULL) {
310 		err = start_pack_privsep_child(pack, packidx);
311 		if (err)
312 			return err;
313 	}
314 
315 	return request_packed_object(obj, pack, idx, id);
316 }
317 
318 static const struct got_error *
319 read_packed_object_raw_privsep(uint8_t **outbuf, off_t *size, size_t *hdrlen,
320     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
321     struct got_object_id *id)
322 {
323 	const struct got_error *err = NULL;
324 
325 	if (pack->privsep_child == NULL) {
326 		err = start_pack_privsep_child(pack, packidx);
327 		if (err)
328 			return err;
329 	}
330 
331 	return request_packed_object_raw(outbuf, size, hdrlen, outfd, pack,
332 	    idx, id);
333 }
334 
335 const struct got_error *
336 got_object_open_packed(struct got_object **obj, struct got_object_id *id,
337     struct got_repository *repo)
338 {
339 	const struct got_error *err = NULL;
340 	struct got_pack *pack = NULL;
341 	struct got_packidx *packidx = NULL;
342 	int idx;
343 	char *path_packfile;
344 
345 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
346 	if (err)
347 		return err;
348 
349 	err = got_packidx_get_packfile_path(&path_packfile,
350 	    packidx->path_packidx);
351 	if (err)
352 		return err;
353 
354 	pack = got_repo_get_cached_pack(repo, path_packfile);
355 	if (pack == NULL) {
356 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
357 		if (err)
358 			goto done;
359 	}
360 
361 	err = read_packed_object_privsep(obj, repo, pack, packidx, idx, id);
362 	if (err)
363 		goto done;
364 done:
365 	free(path_packfile);
366 	return err;
367 }
368 
369 static const struct got_error *
370 request_object(struct got_object **obj, struct got_repository *repo, int fd)
371 {
372 	const struct got_error *err = NULL;
373 	struct imsgbuf *ibuf;
374 
375 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf;
376 
377 	err = got_privsep_send_obj_req(ibuf, fd);
378 	if (err)
379 		return err;
380 
381 	return got_privsep_recv_obj(obj, ibuf);
382 }
383 
384 static const struct got_error *
385 request_raw_object(uint8_t **outbuf, off_t *size, size_t *hdrlen, int outfd,
386     struct got_repository *repo, int infd)
387 {
388 	const struct got_error *err = NULL;
389 	struct imsgbuf *ibuf;
390 	int outfd_child;
391 
392 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf;
393 
394 	outfd_child = dup(outfd);
395 	if (outfd_child == -1)
396 		return got_error_from_errno("dup");
397 
398 	err = got_privsep_send_raw_obj_req(ibuf, infd);
399 	if (err)
400 		return err;
401 
402 	err = got_privsep_send_raw_obj_outfd(ibuf, outfd_child);
403 	if (err)
404 		return err;
405 
406 	return got_privsep_recv_raw_obj(outbuf, size, hdrlen, ibuf);
407 }
408 
409 static const struct got_error *
410 start_read_object_child(struct got_repository *repo)
411 {
412 	const struct got_error *err = NULL;
413 	int imsg_fds[2];
414 	pid_t pid;
415 	struct imsgbuf *ibuf;
416 
417 	ibuf = calloc(1, sizeof(*ibuf));
418 	if (ibuf == NULL)
419 		return got_error_from_errno("calloc");
420 
421 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
422 		err = got_error_from_errno("socketpair");
423 		free(ibuf);
424 		return err;
425 	}
426 
427 	pid = fork();
428 	if (pid == -1) {
429 		err = got_error_from_errno("fork");
430 		free(ibuf);
431 		return err;
432 	}
433 	else if (pid == 0) {
434 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_OBJECT,
435 		    repo->path);
436 		/* not reached */
437 	}
438 
439 	if (close(imsg_fds[1]) == -1) {
440 		err = got_error_from_errno("close");
441 		free(ibuf);
442 		return err;
443 	}
444 
445 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd =
446 	    imsg_fds[0];
447 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].pid = pid;
448 	imsg_init(ibuf, imsg_fds[0]);
449 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf = ibuf;
450 
451 	return NULL;
452 }
453 
454 const struct got_error *
455 got_object_read_header_privsep(struct got_object **obj,
456     struct got_repository *repo, int obj_fd)
457 {
458 	const struct got_error *err;
459 
460 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd != -1)
461 		return request_object(obj, repo, obj_fd);
462 
463 	err = start_read_object_child(repo);
464 	if (err) {
465 		close(obj_fd);
466 		return err;
467 	}
468 
469 	return request_object(obj, repo, obj_fd);
470 }
471 
472 static const struct got_error *
473 read_object_raw_privsep(uint8_t **outbuf, off_t *size, size_t *hdrlen,
474     int outfd, struct got_repository *repo, int obj_fd)
475 {
476 	const struct got_error *err;
477 
478 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd != -1)
479 		return request_raw_object(outbuf, size, hdrlen, outfd, repo,
480 		    obj_fd);
481 
482 	err = start_read_object_child(repo);
483 	if (err)
484 		return err;
485 
486 	return request_raw_object(outbuf, size, hdrlen, outfd, repo, obj_fd);
487 }
488 
489 const struct got_error *
490 got_object_open(struct got_object **obj, struct got_repository *repo,
491     struct got_object_id *id)
492 {
493 	const struct got_error *err = NULL;
494 	int fd;
495 
496 	*obj = got_repo_get_cached_object(repo, id);
497 	if (*obj != NULL) {
498 		(*obj)->refcnt++;
499 		return NULL;
500 	}
501 
502 	err = got_object_open_packed(obj, id, repo);
503 	if (err && err->code != GOT_ERR_NO_OBJ)
504 		return err;
505 	if (*obj) {
506 		(*obj)->refcnt++;
507 		return got_repo_cache_object(repo, id, *obj);
508 	}
509 
510 	err = got_object_open_loose_fd(&fd, id, repo);
511 	if (err) {
512 		if (err->code == GOT_ERR_ERRNO && errno == ENOENT)
513 			err = got_error_no_obj(id);
514 		return err;
515 	}
516 
517 	err = got_object_read_header_privsep(obj, repo, fd);
518 	if (err)
519 		return err;
520 
521 	memcpy((*obj)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
522 
523 	(*obj)->refcnt++;
524 	return got_repo_cache_object(repo, id, *obj);
525 }
526 
527 const struct got_error *
528 got_object_raw_open(struct got_raw_object **obj, struct got_repository *repo,
529     struct got_object_id *id, size_t blocksize)
530 {
531 	const struct got_error *err = NULL;
532 	struct got_packidx *packidx = NULL;
533 	int idx;
534 	uint8_t *outbuf = NULL;
535 	int outfd = -1;
536 	off_t size = 0;
537 	size_t hdrlen = 0;
538 	char *path_packfile = NULL;
539 
540 	*obj = NULL;
541 
542 	outfd = got_opentempfd();
543 	if (outfd == -1)
544 		return got_error_from_errno("got_opentempfd");
545 
546 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
547 	if (err == NULL) {
548 		struct got_pack *pack = NULL;
549 
550 		err = got_packidx_get_packfile_path(&path_packfile,
551 		    packidx->path_packidx);
552 		if (err)
553 			goto done;
554 
555 		pack = got_repo_get_cached_pack(repo, path_packfile);
556 		if (pack == NULL) {
557 			err = got_repo_cache_pack(&pack, repo, path_packfile,
558 			    packidx);
559 			if (err)
560 				goto done;
561 		}
562 		err = read_packed_object_raw_privsep(&outbuf, &size, &hdrlen,
563 		    outfd, pack, packidx, idx, id);
564 	} else if (err->code == GOT_ERR_NO_OBJ) {
565 		int fd;
566 
567 		err = got_object_open_loose_fd(&fd, id, repo);
568 		if (err)
569 			goto done;
570 		err = read_object_raw_privsep(&outbuf, &size, &hdrlen, outfd,
571 		    repo, fd);
572 	}
573 
574 	*obj = calloc(1, sizeof(**obj));
575 	if (*obj == NULL) {
576 		err = got_error_from_errno("calloc");
577 		goto done;
578 	}
579 
580 	(*obj)->read_buf = malloc(blocksize);
581 	if ((*obj)->read_buf == NULL) {
582 		err = got_error_from_errno("malloc");
583 		goto done;
584 	}
585 
586 	if (outbuf) {
587 		if (close(outfd) == -1) {
588 			err = got_error_from_errno("close");
589 			goto done;
590 		}
591 		outfd = -1;
592 		(*obj)->f = fmemopen(outbuf, hdrlen + size, "r");
593 		if ((*obj)->f == NULL) {
594 			err = got_error_from_errno("fdopen");
595 			goto done;
596 		}
597 		(*obj)->data = outbuf;
598 	} else {
599 		struct stat sb;
600 		if (fstat(outfd, &sb) == -1) {
601 			err = got_error_from_errno("fstat");
602 			goto done;
603 		}
604 
605 		if (sb.st_size != hdrlen + size) {
606 			err = got_error(GOT_ERR_PRIVSEP_LEN);
607 			goto done;
608 		}
609 
610 		(*obj)->f = fdopen(outfd, "r");
611 		if ((*obj)->f == NULL) {
612 			err = got_error_from_errno("fdopen");
613 			goto done;
614 		}
615 		outfd = -1;
616 		(*obj)->data = NULL;
617 	}
618 	(*obj)->hdrlen = hdrlen;
619 	(*obj)->size = size;
620 	(*obj)->blocksize = blocksize;
621 done:
622 	free(path_packfile);
623 	if (err) {
624 		if (*obj) {
625 			got_object_raw_close(*obj);
626 			*obj = NULL;
627 		}
628 		if (outfd != -1)
629 			close(outfd);
630 		free(outbuf);
631 	}
632 	return err;
633 }
634 
635 void
636 got_object_raw_rewind(struct got_raw_object *obj)
637 {
638 	if (obj->f)
639 		rewind(obj->f);
640 }
641 
642 size_t
643 got_object_raw_get_hdrlen(struct got_raw_object *obj)
644 {
645 	return obj->hdrlen;
646 }
647 
648 const uint8_t *
649 got_object_raw_get_read_buf(struct got_raw_object *obj)
650 {
651 	return obj->read_buf;
652 }
653 
654 const struct got_error *
655 got_object_raw_read_block(size_t *outlenp, struct got_raw_object *obj)
656 {
657 	size_t n;
658 
659 	n = fread(obj->read_buf, 1, obj->blocksize, obj->f);
660 	if (n == 0 && ferror(obj->f))
661 		return got_ferror(obj->f, GOT_ERR_IO);
662 	*outlenp = n;
663 	return NULL;
664 }
665 
666 const struct got_error *
667 got_object_raw_close(struct got_raw_object *obj)
668 {
669 	const struct got_error *err = NULL;
670 
671 	free(obj->read_buf);
672 	if (obj->f != NULL && fclose(obj->f) == EOF && err == NULL)
673 		err = got_error_from_errno("fclose");
674 	free(obj->data);
675 	free(obj);
676 	return err;
677 }
678 
679 const struct got_error *
680 got_object_open_by_id_str(struct got_object **obj, struct got_repository *repo,
681     const char *id_str)
682 {
683 	struct got_object_id id;
684 
685 	if (!got_parse_sha1_digest(id.sha1, id_str))
686 		return got_error_path(id_str, GOT_ERR_BAD_OBJ_ID_STR);
687 
688 	return got_object_open(obj, repo, &id);
689 }
690 
691 const struct got_error *
692 got_object_resolve_id_str(struct got_object_id **id,
693     struct got_repository *repo, const char *id_str)
694 {
695 	const struct got_error *err = NULL;
696 	struct got_object *obj;
697 
698 	err = got_object_open_by_id_str(&obj, repo, id_str);
699 	if (err)
700 		return err;
701 
702 	*id = got_object_id_dup(got_object_get_id(obj));
703 	got_object_close(obj);
704 	if (*id == NULL)
705 		return got_error_from_errno("got_object_id_dup");
706 
707 	return NULL;
708 }
709 
710 static const struct got_error *
711 request_packed_commit(struct got_commit_object **commit, struct got_pack *pack,
712     int pack_idx, struct got_object_id *id)
713 {
714 	const struct got_error *err = NULL;
715 
716 	err = got_privsep_send_commit_req(pack->privsep_child->ibuf, -1, id,
717 	    pack_idx);
718 	if (err)
719 		return err;
720 
721 	err = got_privsep_recv_commit(commit, pack->privsep_child->ibuf);
722 	if (err)
723 		return err;
724 
725 	(*commit)->flags |= GOT_COMMIT_FLAG_PACKED;
726 	return NULL;
727 }
728 
729 static const struct got_error *
730 read_packed_commit_privsep(struct got_commit_object **commit,
731     struct got_pack *pack, struct got_packidx *packidx, int idx,
732     struct got_object_id *id)
733 {
734 	const struct got_error *err = NULL;
735 
736 	if (pack->privsep_child)
737 		return request_packed_commit(commit, pack, idx, id);
738 
739 	err = start_pack_privsep_child(pack, packidx);
740 	if (err)
741 		return err;
742 
743 	return request_packed_commit(commit, pack, idx, id);
744 }
745 
746 static const struct got_error *
747 request_commit(struct got_commit_object **commit, struct got_repository *repo,
748     int fd)
749 {
750 	const struct got_error *err = NULL;
751 	struct imsgbuf *ibuf;
752 
753 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf;
754 
755 	err = got_privsep_send_commit_req(ibuf, fd, NULL, -1);
756 	if (err)
757 		return err;
758 
759 	return got_privsep_recv_commit(commit, ibuf);
760 }
761 
762 static const struct got_error *
763 read_commit_privsep(struct got_commit_object **commit, int obj_fd,
764     struct got_repository *repo)
765 {
766 	const struct got_error *err;
767 	int imsg_fds[2];
768 	pid_t pid;
769 	struct imsgbuf *ibuf;
770 
771 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd != -1)
772 		return request_commit(commit, repo, obj_fd);
773 
774 	ibuf = calloc(1, sizeof(*ibuf));
775 	if (ibuf == NULL)
776 		return got_error_from_errno("calloc");
777 
778 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
779 		err = got_error_from_errno("socketpair");
780 		free(ibuf);
781 		return err;
782 	}
783 
784 	pid = fork();
785 	if (pid == -1) {
786 		err = got_error_from_errno("fork");
787 		free(ibuf);
788 		return err;
789 	}
790 	else if (pid == 0) {
791 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_COMMIT,
792 		    repo->path);
793 		/* not reached */
794 	}
795 
796 	if (close(imsg_fds[1]) == -1) {
797 		err = got_error_from_errno("close");
798 		free(ibuf);
799 		return err;
800 	}
801 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd =
802 	    imsg_fds[0];
803 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].pid = pid;
804 	imsg_init(ibuf, imsg_fds[0]);
805 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf = ibuf;
806 
807 	return request_commit(commit, repo, obj_fd);
808 }
809 
810 
811 static const struct got_error *
812 open_commit(struct got_commit_object **commit,
813     struct got_repository *repo, struct got_object_id *id, int check_cache)
814 {
815 	const struct got_error *err = NULL;
816 	struct got_packidx *packidx = NULL;
817 	int idx;
818 	char *path_packfile = NULL;
819 
820 	if (check_cache) {
821 		*commit = got_repo_get_cached_commit(repo, id);
822 		if (*commit != NULL) {
823 			(*commit)->refcnt++;
824 			return NULL;
825 		}
826 	} else
827 		*commit = NULL;
828 
829 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
830 	if (err == NULL) {
831 		struct got_pack *pack = NULL;
832 
833 		err = got_packidx_get_packfile_path(&path_packfile,
834 		    packidx->path_packidx);
835 		if (err)
836 			return err;
837 
838 		pack = got_repo_get_cached_pack(repo, path_packfile);
839 		if (pack == NULL) {
840 			err = got_repo_cache_pack(&pack, repo, path_packfile,
841 			    packidx);
842 			if (err)
843 				goto done;
844 		}
845 		err = read_packed_commit_privsep(commit, pack,
846 		    packidx, idx, id);
847 	} else if (err->code == GOT_ERR_NO_OBJ) {
848 		int fd;
849 
850 		err = got_object_open_loose_fd(&fd, id, repo);
851 		if (err)
852 			return err;
853 		err = read_commit_privsep(commit, fd, repo);
854 	}
855 
856 	if (err == NULL) {
857 		(*commit)->refcnt++;
858 		err = got_repo_cache_commit(repo, id, *commit);
859 	}
860 done:
861 	free(path_packfile);
862 	return err;
863 }
864 
865 const struct got_error *
866 got_object_open_as_commit(struct got_commit_object **commit,
867     struct got_repository *repo, struct got_object_id *id)
868 {
869 	*commit = got_repo_get_cached_commit(repo, id);
870 	if (*commit != NULL) {
871 		(*commit)->refcnt++;
872 		return NULL;
873 	}
874 
875 	return open_commit(commit, repo, id, 0);
876 }
877 
878 const struct got_error *
879 got_object_commit_open(struct got_commit_object **commit,
880     struct got_repository *repo, struct got_object *obj)
881 {
882 	return open_commit(commit, repo, got_object_get_id(obj), 1);
883 }
884 
885 const struct got_error *
886 got_object_qid_alloc(struct got_object_qid **qid, struct got_object_id *id)
887 {
888 	const struct got_error *err = NULL;
889 
890 	*qid = calloc(1, sizeof(**qid));
891 	if (*qid == NULL)
892 		return got_error_from_errno("calloc");
893 
894 	(*qid)->id = got_object_id_dup(id);
895 	if ((*qid)->id == NULL) {
896 		err = got_error_from_errno("got_object_id_dup");
897 		got_object_qid_free(*qid);
898 		*qid = NULL;
899 		return err;
900 	}
901 
902 	return NULL;
903 }
904 
905 const struct got_error *
906 got_object_id_queue_copy(const struct got_object_id_queue *src,
907     struct got_object_id_queue *dest)
908 {
909 	const struct got_error *err;
910 	struct got_object_qid *qid;
911 
912 	STAILQ_FOREACH(qid, src, entry) {
913 		struct got_object_qid *new;
914 		/*
915 		 * Deep-copy the object ID only. Let the caller deal
916 		 * with setting up the new->data pointer if needed.
917 		 */
918 		err = got_object_qid_alloc(&new, qid->id); 
919 		if (err) {
920 			got_object_id_queue_free(dest);
921 			return err;
922 		}
923 		STAILQ_INSERT_TAIL(dest, new, entry);
924 	}
925 
926 	return NULL;
927 }
928 
929 static const struct got_error *
930 request_packed_tree(struct got_tree_object **tree, struct got_pack *pack,
931     int pack_idx, struct got_object_id *id)
932 {
933 	const struct got_error *err = NULL;
934 
935 	err = got_privsep_send_tree_req(pack->privsep_child->ibuf, -1, id,
936 	    pack_idx);
937 	if (err)
938 		return err;
939 
940 	return got_privsep_recv_tree(tree, pack->privsep_child->ibuf);
941 }
942 
943 static const struct got_error *
944 read_packed_tree_privsep(struct got_tree_object **tree,
945     struct got_pack *pack, struct got_packidx *packidx, int idx,
946     struct got_object_id *id)
947 {
948 	const struct got_error *err = NULL;
949 
950 	if (pack->privsep_child)
951 		return request_packed_tree(tree, pack, idx, id);
952 
953 	err = start_pack_privsep_child(pack, packidx);
954 	if (err)
955 		return err;
956 
957 	return request_packed_tree(tree, pack, idx, id);
958 }
959 
960 static const struct got_error *
961 request_tree(struct got_tree_object **tree, struct got_repository *repo,
962     int fd)
963 {
964 	const struct got_error *err = NULL;
965 	struct imsgbuf *ibuf;
966 
967 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf;
968 
969 	err = got_privsep_send_tree_req(ibuf, fd, NULL, -1);
970 	if (err)
971 		return err;
972 
973 	return got_privsep_recv_tree(tree, ibuf);
974 }
975 
976 const struct got_error *
977 read_tree_privsep(struct got_tree_object **tree, int obj_fd,
978     struct got_repository *repo)
979 {
980 	const struct got_error *err;
981 	int imsg_fds[2];
982 	pid_t pid;
983 	struct imsgbuf *ibuf;
984 
985 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd != -1)
986 		return request_tree(tree, repo, obj_fd);
987 
988 	ibuf = calloc(1, sizeof(*ibuf));
989 	if (ibuf == NULL)
990 		return got_error_from_errno("calloc");
991 
992 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
993 		err = got_error_from_errno("socketpair");
994 		free(ibuf);
995 		return err;
996 	}
997 
998 	pid = fork();
999 	if (pid == -1) {
1000 		err = got_error_from_errno("fork");
1001 		free(ibuf);
1002 		return err;
1003 	}
1004 	else if (pid == 0) {
1005 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TREE,
1006 		    repo->path);
1007 		/* not reached */
1008 	}
1009 
1010 	if (close(imsg_fds[1]) == -1) {
1011 		err = got_error_from_errno("close");
1012 		free(ibuf);
1013 		return err;
1014 	}
1015 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd =
1016 	    imsg_fds[0];
1017 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].pid = pid;
1018 	imsg_init(ibuf, imsg_fds[0]);
1019 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf = ibuf;
1020 
1021 
1022 	return request_tree(tree, repo, obj_fd);
1023 }
1024 
1025 static const struct got_error *
1026 open_tree(struct got_tree_object **tree, struct got_repository *repo,
1027     struct got_object_id *id, int check_cache)
1028 {
1029 	const struct got_error *err = NULL;
1030 	struct got_packidx *packidx = NULL;
1031 	int idx;
1032 	char *path_packfile = NULL;
1033 
1034 	if (check_cache) {
1035 		*tree = got_repo_get_cached_tree(repo, id);
1036 		if (*tree != NULL) {
1037 			(*tree)->refcnt++;
1038 			return NULL;
1039 		}
1040 	} else
1041 		*tree = NULL;
1042 
1043 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1044 	if (err == NULL) {
1045 		struct got_pack *pack = NULL;
1046 
1047 		err = got_packidx_get_packfile_path(&path_packfile,
1048 		    packidx->path_packidx);
1049 		if (err)
1050 			return err;
1051 
1052 		pack = got_repo_get_cached_pack(repo, path_packfile);
1053 		if (pack == NULL) {
1054 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1055 			    packidx);
1056 			if (err)
1057 				goto done;
1058 		}
1059 		err = read_packed_tree_privsep(tree, pack,
1060 		    packidx, idx, id);
1061 	} else if (err->code == GOT_ERR_NO_OBJ) {
1062 		int fd;
1063 
1064 		err = got_object_open_loose_fd(&fd, id, repo);
1065 		if (err)
1066 			return err;
1067 		err = read_tree_privsep(tree, fd, repo);
1068 	}
1069 
1070 	if (err == NULL) {
1071 		(*tree)->refcnt++;
1072 		err = got_repo_cache_tree(repo, id, *tree);
1073 	}
1074 done:
1075 	free(path_packfile);
1076 	return err;
1077 }
1078 
1079 const struct got_error *
1080 got_object_open_as_tree(struct got_tree_object **tree,
1081     struct got_repository *repo, struct got_object_id *id)
1082 {
1083 	*tree = got_repo_get_cached_tree(repo, id);
1084 	if (*tree != NULL) {
1085 		(*tree)->refcnt++;
1086 		return NULL;
1087 	}
1088 
1089 	return open_tree(tree, repo, id, 0);
1090 }
1091 
1092 const struct got_error *
1093 got_object_tree_open(struct got_tree_object **tree,
1094     struct got_repository *repo, struct got_object *obj)
1095 {
1096 	return open_tree(tree, repo, got_object_get_id(obj), 1);
1097 }
1098 
1099 int
1100 got_object_tree_get_nentries(struct got_tree_object *tree)
1101 {
1102 	return tree->nentries;
1103 }
1104 
1105 struct got_tree_entry *
1106 got_object_tree_get_first_entry(struct got_tree_object *tree)
1107 {
1108 	return got_object_tree_get_entry(tree, 0);
1109 }
1110 
1111 struct got_tree_entry *
1112 got_object_tree_get_last_entry(struct got_tree_object *tree)
1113 {
1114 	return got_object_tree_get_entry(tree, tree->nentries - 1);
1115 }
1116 
1117 struct got_tree_entry *
1118 got_object_tree_get_entry(struct got_tree_object *tree, int i)
1119 {
1120 	if (i < 0 || i >= tree->nentries)
1121 		return NULL;
1122 	return &tree->entries[i];
1123 }
1124 
1125 mode_t
1126 got_tree_entry_get_mode(struct got_tree_entry *te)
1127 {
1128 	return te->mode;
1129 }
1130 
1131 const char *
1132 got_tree_entry_get_name(struct got_tree_entry *te)
1133 {
1134 	return &te->name[0];
1135 }
1136 
1137 struct got_object_id *
1138 got_tree_entry_get_id(struct got_tree_entry *te)
1139 {
1140 	return &te->id;
1141 }
1142 
1143 const struct got_error *
1144 got_object_blob_read_to_str(char **s, struct got_blob_object *blob)
1145 {
1146 	const struct got_error *err = NULL;
1147 	size_t len, totlen, hdrlen, offset;
1148 
1149 	*s = NULL;
1150 
1151 	hdrlen = got_object_blob_get_hdrlen(blob);
1152 	totlen = 0;
1153 	offset = 0;
1154 	do {
1155 		char *p;
1156 
1157 		err = got_object_blob_read_block(&len, blob);
1158 		if (err)
1159 			return err;
1160 
1161 		if (len == 0)
1162 			break;
1163 
1164 		totlen += len - hdrlen;
1165 		p = realloc(*s, totlen + 1);
1166 		if (p == NULL) {
1167 			err = got_error_from_errno("realloc");
1168 			free(*s);
1169 			*s = NULL;
1170 			return err;
1171 		}
1172 		*s = p;
1173 		/* Skip blob object header first time around. */
1174 		memcpy(*s + offset,
1175 		    got_object_blob_get_read_buf(blob) + hdrlen, len - hdrlen);
1176 		hdrlen = 0;
1177 		offset = totlen;
1178 	} while (len > 0);
1179 
1180 	(*s)[totlen] = '\0';
1181 	return NULL;
1182 }
1183 
1184 const struct got_error *
1185 got_tree_entry_get_symlink_target(char **link_target, struct got_tree_entry *te,
1186     struct got_repository *repo)
1187 {
1188 	const struct got_error *err = NULL;
1189 	struct got_blob_object *blob = NULL;
1190 
1191 	*link_target = NULL;
1192 
1193 	if (!got_object_tree_entry_is_symlink(te))
1194 		return got_error(GOT_ERR_TREE_ENTRY_TYPE);
1195 
1196 	err = got_object_open_as_blob(&blob, repo,
1197 	    got_tree_entry_get_id(te), PATH_MAX);
1198 	if (err)
1199 		return err;
1200 
1201 	err = got_object_blob_read_to_str(link_target, blob);
1202 	got_object_blob_close(blob);
1203 	if (err) {
1204 		free(*link_target);
1205 		*link_target = NULL;
1206 	}
1207 	return err;
1208 }
1209 
1210 int
1211 got_tree_entry_get_index(struct got_tree_entry *te)
1212 {
1213 	return te->idx;
1214 }
1215 
1216 struct got_tree_entry *
1217 got_tree_entry_get_next(struct got_tree_object *tree,
1218     struct got_tree_entry *te)
1219 {
1220 	return got_object_tree_get_entry(tree, te->idx + 1);
1221 }
1222 
1223 struct got_tree_entry *
1224 got_tree_entry_get_prev(struct got_tree_object *tree,
1225     struct got_tree_entry *te)
1226 {
1227 	return got_object_tree_get_entry(tree, te->idx - 1);
1228 }
1229 
1230 static const struct got_error *
1231 request_packed_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
1232     struct got_pack *pack, struct got_packidx *packidx, int idx,
1233     struct got_object_id *id)
1234 {
1235 	const struct got_error *err = NULL;
1236 	int outfd_child;
1237 	int basefd, accumfd; /* temporary files for delta application */
1238 
1239 	basefd = got_opentempfd();
1240 	if (basefd == -1)
1241 		return got_error_from_errno("got_opentempfd");
1242 	accumfd = got_opentempfd();
1243 	if (accumfd == -1)
1244 		return got_error_from_errno("got_opentempfd");
1245 
1246 	outfd_child = dup(outfd);
1247 	if (outfd_child == -1)
1248 		return got_error_from_errno("dup");
1249 
1250 	err = got_privsep_send_blob_req(pack->privsep_child->ibuf, -1, id, idx);
1251 	if (err)
1252 		return err;
1253 
1254 	err = got_privsep_send_blob_outfd(pack->privsep_child->ibuf,
1255 	    outfd_child);
1256 	if (err) {
1257 		close(basefd);
1258 		close(accumfd);
1259 		return err;
1260 	}
1261 
1262 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
1263 	    basefd);
1264 	if (err) {
1265 		close(accumfd);
1266 		return err;
1267 	}
1268 
1269 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
1270 	    accumfd);
1271 	if (err)
1272 		return err;
1273 
1274 	err = got_privsep_recv_blob(outbuf, size, hdrlen,
1275 	    pack->privsep_child->ibuf);
1276 	if (err)
1277 		return err;
1278 
1279 	if (lseek(outfd, SEEK_SET, 0) == -1)
1280 		err = got_error_from_errno("lseek");
1281 
1282 	return err;
1283 }
1284 
1285 static const struct got_error *
1286 read_packed_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1287     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
1288     struct got_object_id *id)
1289 {
1290 	const struct got_error *err = NULL;
1291 
1292 	if (pack->privsep_child == NULL) {
1293 		err = start_pack_privsep_child(pack, packidx);
1294 		if (err)
1295 			return err;
1296 	}
1297 
1298 	return request_packed_blob(outbuf, size, hdrlen, outfd, pack, packidx,
1299 	    idx, id);
1300 }
1301 
1302 static const struct got_error *
1303 request_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
1304     int infd, struct imsgbuf *ibuf)
1305 {
1306 	const struct got_error *err = NULL;
1307 	int outfd_child;
1308 
1309 	outfd_child = dup(outfd);
1310 	if (outfd_child == -1)
1311 		return got_error_from_errno("dup");
1312 
1313 	err = got_privsep_send_blob_req(ibuf, infd, NULL, -1);
1314 	if (err)
1315 		return err;
1316 
1317 	err = got_privsep_send_blob_outfd(ibuf, outfd_child);
1318 	if (err)
1319 		return err;
1320 
1321 	err = got_privsep_recv_blob(outbuf, size, hdrlen, ibuf);
1322 	if (err)
1323 		return err;
1324 
1325 	if (lseek(outfd, SEEK_SET, 0) == -1)
1326 		return got_error_from_errno("lseek");
1327 
1328 	return err;
1329 }
1330 
1331 static const struct got_error *
1332 read_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1333     int outfd, int infd, struct got_repository *repo)
1334 {
1335 	const struct got_error *err;
1336 	int imsg_fds[2];
1337 	pid_t pid;
1338 	struct imsgbuf *ibuf;
1339 
1340 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd != -1) {
1341 		ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf;
1342 		return request_blob(outbuf, size, hdrlen, outfd, infd, ibuf);
1343 	}
1344 
1345 	ibuf = calloc(1, sizeof(*ibuf));
1346 	if (ibuf == NULL)
1347 		return got_error_from_errno("calloc");
1348 
1349 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1350 		err = got_error_from_errno("socketpair");
1351 		free(ibuf);
1352 		return err;
1353 	}
1354 
1355 	pid = fork();
1356 	if (pid == -1) {
1357 		err = got_error_from_errno("fork");
1358 		free(ibuf);
1359 		return err;
1360 	}
1361 	else if (pid == 0) {
1362 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_BLOB,
1363 		    repo->path);
1364 		/* not reached */
1365 	}
1366 
1367 	if (close(imsg_fds[1]) == -1) {
1368 		err = got_error_from_errno("close");
1369 		free(ibuf);
1370 		return err;
1371 	}
1372 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd =
1373 	    imsg_fds[0];
1374 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].pid = pid;
1375 	imsg_init(ibuf, imsg_fds[0]);
1376 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf = ibuf;
1377 
1378 	return request_blob(outbuf, size, hdrlen, outfd, infd, ibuf);
1379 }
1380 
1381 static const struct got_error *
1382 open_blob(struct got_blob_object **blob, struct got_repository *repo,
1383     struct got_object_id *id, size_t blocksize)
1384 {
1385 	const struct got_error *err = NULL;
1386 	struct got_packidx *packidx = NULL;
1387 	int idx;
1388 	char *path_packfile = NULL;
1389 	uint8_t *outbuf;
1390 	int outfd;
1391 	size_t size, hdrlen;
1392 	struct stat sb;
1393 
1394 	*blob = calloc(1, sizeof(**blob));
1395 	if (*blob == NULL)
1396 		return got_error_from_errno("calloc");
1397 
1398 	outfd = got_opentempfd();
1399 	if (outfd == -1)
1400 		return got_error_from_errno("got_opentempfd");
1401 
1402 	(*blob)->read_buf = malloc(blocksize);
1403 	if ((*blob)->read_buf == NULL) {
1404 		err = got_error_from_errno("malloc");
1405 		goto done;
1406 	}
1407 
1408 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1409 	if (err == NULL) {
1410 		struct got_pack *pack = NULL;
1411 
1412 		err = got_packidx_get_packfile_path(&path_packfile,
1413 		    packidx->path_packidx);
1414 		if (err)
1415 			goto done;
1416 
1417 		pack = got_repo_get_cached_pack(repo, path_packfile);
1418 		if (pack == NULL) {
1419 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1420 			    packidx);
1421 			if (err)
1422 				goto done;
1423 		}
1424 		err = read_packed_blob_privsep(&outbuf, &size, &hdrlen, outfd,
1425 		    pack, packidx, idx, id);
1426 	} else if (err->code == GOT_ERR_NO_OBJ) {
1427 		int infd;
1428 
1429 		err = got_object_open_loose_fd(&infd, id, repo);
1430 		if (err)
1431 			goto done;
1432 		err = read_blob_privsep(&outbuf, &size, &hdrlen, outfd, infd,
1433 		    repo);
1434 	}
1435 	if (err)
1436 		goto done;
1437 
1438 	if (hdrlen > size) {
1439 		err = got_error(GOT_ERR_BAD_OBJ_HDR);
1440 		goto done;
1441 	}
1442 
1443 	if (outbuf) {
1444 		if (close(outfd) == -1 && err == NULL)
1445 			err = got_error_from_errno("close");
1446 		outfd = -1;
1447 		(*blob)->f = fmemopen(outbuf, size, "rb");
1448 		if ((*blob)->f == NULL) {
1449 			err = got_error_from_errno("fmemopen");
1450 			free(outbuf);
1451 			goto done;
1452 		}
1453 		(*blob)->data = outbuf;
1454 	} else {
1455 		if (fstat(outfd, &sb) == -1) {
1456 			err = got_error_from_errno("fstat");
1457 			goto done;
1458 		}
1459 
1460 		if (sb.st_size != size) {
1461 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1462 			goto done;
1463 		}
1464 
1465 		(*blob)->f = fdopen(outfd, "rb");
1466 		if ((*blob)->f == NULL) {
1467 			err = got_error_from_errno("fdopen");
1468 			close(outfd);
1469 			outfd = -1;
1470 			goto done;
1471 		}
1472 	}
1473 
1474 	(*blob)->hdrlen = hdrlen;
1475 	(*blob)->blocksize = blocksize;
1476 	memcpy(&(*blob)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
1477 
1478 done:
1479 	free(path_packfile);
1480 	if (err) {
1481 		if (*blob) {
1482 			got_object_blob_close(*blob);
1483 			*blob = NULL;
1484 		} else if (outfd != -1)
1485 			close(outfd);
1486 	}
1487 	return err;
1488 }
1489 
1490 const struct got_error *
1491 got_object_open_as_blob(struct got_blob_object **blob,
1492     struct got_repository *repo, struct got_object_id *id,
1493     size_t blocksize)
1494 {
1495 	return open_blob(blob, repo, id, blocksize);
1496 }
1497 
1498 const struct got_error *
1499 got_object_blob_open(struct got_blob_object **blob,
1500     struct got_repository *repo, struct got_object *obj, size_t blocksize)
1501 {
1502 	return open_blob(blob, repo, got_object_get_id(obj), blocksize);
1503 }
1504 
1505 const struct got_error *
1506 got_object_blob_close(struct got_blob_object *blob)
1507 {
1508 	const struct got_error *err = NULL;
1509 	free(blob->read_buf);
1510 	if (blob->f && fclose(blob->f) == EOF)
1511 		err = got_error_from_errno("fclose");
1512 	free(blob->data);
1513 	free(blob);
1514 	return err;
1515 }
1516 
1517 void
1518 got_object_blob_rewind(struct got_blob_object *blob)
1519 {
1520 	if (blob->f)
1521 		rewind(blob->f);
1522 }
1523 
1524 char *
1525 got_object_blob_id_str(struct got_blob_object *blob, char *buf, size_t size)
1526 {
1527 	return got_sha1_digest_to_str(blob->id.sha1, buf, size);
1528 }
1529 
1530 size_t
1531 got_object_blob_get_hdrlen(struct got_blob_object *blob)
1532 {
1533 	return blob->hdrlen;
1534 }
1535 
1536 const uint8_t *
1537 got_object_blob_get_read_buf(struct got_blob_object *blob)
1538 {
1539 	return blob->read_buf;
1540 }
1541 
1542 const struct got_error *
1543 got_object_blob_read_block(size_t *outlenp, struct got_blob_object *blob)
1544 {
1545 	size_t n;
1546 
1547 	n = fread(blob->read_buf, 1, blob->blocksize, blob->f);
1548 	if (n == 0 && ferror(blob->f))
1549 		return got_ferror(blob->f, GOT_ERR_IO);
1550 	*outlenp = n;
1551 	return NULL;
1552 }
1553 
1554 const struct got_error *
1555 got_object_blob_dump_to_file(off_t *filesize, int *nlines,
1556     off_t **line_offsets, FILE *outfile, struct got_blob_object *blob)
1557 {
1558 	const struct got_error *err = NULL;
1559 	size_t n, len, hdrlen;
1560 	const uint8_t *buf;
1561 	int i;
1562 	const int alloc_chunksz = 512;
1563 	size_t nalloc = 0;
1564 	off_t off = 0, total_len = 0;
1565 
1566 	if (line_offsets)
1567 		*line_offsets = NULL;
1568 	if (filesize)
1569 		*filesize = 0;
1570 	if (nlines)
1571 		*nlines = 0;
1572 
1573 	hdrlen = got_object_blob_get_hdrlen(blob);
1574 	do {
1575 		err = got_object_blob_read_block(&len, blob);
1576 		if (err)
1577 			return err;
1578 		if (len == 0)
1579 			break;
1580 		buf = got_object_blob_get_read_buf(blob);
1581 		i = hdrlen;
1582 		if (nlines) {
1583 			if (line_offsets && *line_offsets == NULL) {
1584 				/* Have some data but perhaps no '\n'. */
1585 				*nlines = 1;
1586 				nalloc = alloc_chunksz;
1587 				*line_offsets = calloc(nalloc,
1588 				    sizeof(**line_offsets));
1589 				if (*line_offsets == NULL)
1590 					return got_error_from_errno("calloc");
1591 
1592 				/* Skip forward over end of first line. */
1593 				while (i < len) {
1594 					if (buf[i] == '\n')
1595 						break;
1596 					i++;
1597 				}
1598 			}
1599 			/* Scan '\n' offsets in remaining chunk of data. */
1600 			while (i < len) {
1601 				if (buf[i] != '\n') {
1602 					i++;
1603 					continue;
1604 				}
1605 				(*nlines)++;
1606 				if (line_offsets && nalloc < *nlines) {
1607 					size_t n = *nlines + alloc_chunksz;
1608 					off_t *o = recallocarray(*line_offsets,
1609 					    nalloc, n, sizeof(**line_offsets));
1610 					if (o == NULL) {
1611 						free(*line_offsets);
1612 						*line_offsets = NULL;
1613 						return got_error_from_errno(
1614 						    "recallocarray");
1615 					}
1616 					*line_offsets = o;
1617 					nalloc = n;
1618 				}
1619 				if (line_offsets) {
1620 					off = total_len + i - hdrlen + 1;
1621 					(*line_offsets)[*nlines - 1] = off;
1622 				}
1623 				i++;
1624 			}
1625 		}
1626 		/* Skip blob object header first time around. */
1627 		n = fwrite(buf + hdrlen, 1, len - hdrlen, outfile);
1628 		if (n != len - hdrlen)
1629 			return got_ferror(outfile, GOT_ERR_IO);
1630 		total_len += len - hdrlen;
1631 		hdrlen = 0;
1632 	} while (len != 0);
1633 
1634 	if (fflush(outfile) != 0)
1635 		return got_error_from_errno("fflush");
1636 	rewind(outfile);
1637 
1638 	if (filesize)
1639 		*filesize = total_len;
1640 
1641 	return NULL;
1642 }
1643 
1644 static const struct got_error *
1645 request_packed_tag(struct got_tag_object **tag, struct got_pack *pack,
1646     int pack_idx, struct got_object_id *id)
1647 {
1648 	const struct got_error *err = NULL;
1649 
1650 	err = got_privsep_send_tag_req(pack->privsep_child->ibuf, -1, id,
1651 	    pack_idx);
1652 	if (err)
1653 		return err;
1654 
1655 	return got_privsep_recv_tag(tag, pack->privsep_child->ibuf);
1656 }
1657 
1658 static const struct got_error *
1659 read_packed_tag_privsep(struct got_tag_object **tag,
1660     struct got_pack *pack, struct got_packidx *packidx, int idx,
1661     struct got_object_id *id)
1662 {
1663 	const struct got_error *err = NULL;
1664 
1665 	if (pack->privsep_child)
1666 		return request_packed_tag(tag, pack, idx, id);
1667 
1668 	err = start_pack_privsep_child(pack, packidx);
1669 	if (err)
1670 		return err;
1671 
1672 	return request_packed_tag(tag, pack, idx, id);
1673 }
1674 
1675 static const struct got_error *
1676 request_tag(struct got_tag_object **tag, struct got_repository *repo,
1677     int fd)
1678 {
1679 	const struct got_error *err = NULL;
1680 	struct imsgbuf *ibuf;
1681 
1682 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf;
1683 
1684 	err = got_privsep_send_tag_req(ibuf, fd, NULL, -1);
1685 	if (err)
1686 		return err;
1687 
1688 	return got_privsep_recv_tag(tag, ibuf);
1689 }
1690 
1691 static const struct got_error *
1692 read_tag_privsep(struct got_tag_object **tag, int obj_fd,
1693     struct got_repository *repo)
1694 {
1695 	const struct got_error *err;
1696 	int imsg_fds[2];
1697 	pid_t pid;
1698 	struct imsgbuf *ibuf;
1699 
1700 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd != -1)
1701 		return request_tag(tag, repo, obj_fd);
1702 
1703 	ibuf = calloc(1, sizeof(*ibuf));
1704 	if (ibuf == NULL)
1705 		return got_error_from_errno("calloc");
1706 
1707 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1708 		err = got_error_from_errno("socketpair");
1709 		free(ibuf);
1710 		return err;
1711 	}
1712 
1713 	pid = fork();
1714 	if (pid == -1) {
1715 		err = got_error_from_errno("fork");
1716 		free(ibuf);
1717 		return err;
1718 	}
1719 	else if (pid == 0) {
1720 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TAG,
1721 		    repo->path);
1722 		/* not reached */
1723 	}
1724 
1725 	if (close(imsg_fds[1]) == -1) {
1726 		err = got_error_from_errno("close");
1727 		free(ibuf);
1728 		return err;
1729 	}
1730 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd =
1731 	    imsg_fds[0];
1732 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].pid = pid;
1733 	imsg_init(ibuf, imsg_fds[0]);
1734 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf = ibuf;
1735 
1736 	return request_tag(tag, repo, obj_fd);
1737 }
1738 
1739 static const struct got_error *
1740 open_tag(struct got_tag_object **tag, struct got_repository *repo,
1741     struct got_object_id *id, int check_cache)
1742 {
1743 	const struct got_error *err = NULL;
1744 	struct got_packidx *packidx = NULL;
1745 	int idx;
1746 	char *path_packfile = NULL;
1747 	struct got_object *obj = NULL;
1748 	int obj_type = GOT_OBJ_TYPE_ANY;
1749 
1750 	if (check_cache) {
1751 		*tag = got_repo_get_cached_tag(repo, id);
1752 		if (*tag != NULL) {
1753 			(*tag)->refcnt++;
1754 			return NULL;
1755 		}
1756 	} else
1757 		*tag = NULL;
1758 
1759 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1760 	if (err == NULL) {
1761 		struct got_pack *pack = NULL;
1762 
1763 		err = got_packidx_get_packfile_path(&path_packfile,
1764 		    packidx->path_packidx);
1765 		if (err)
1766 			return err;
1767 
1768 		pack = got_repo_get_cached_pack(repo, path_packfile);
1769 		if (pack == NULL) {
1770 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1771 			    packidx);
1772 			if (err)
1773 				goto done;
1774 		}
1775 
1776 		/* Beware of "lightweight" tags: Check object type first. */
1777 		err = read_packed_object_privsep(&obj, repo, pack, packidx,
1778 		    idx, id);
1779 		if (err)
1780 			goto done;
1781 		obj_type = obj->type;
1782 		got_object_close(obj);
1783 		if (obj_type != GOT_OBJ_TYPE_TAG) {
1784 			err = got_error(GOT_ERR_OBJ_TYPE);
1785 			goto done;
1786 		}
1787 		err = read_packed_tag_privsep(tag, pack, packidx, idx, id);
1788 	} else if (err->code == GOT_ERR_NO_OBJ) {
1789 		int fd;
1790 
1791 		err = got_object_open_loose_fd(&fd, id, repo);
1792 		if (err)
1793 			return err;
1794 		err = got_object_read_header_privsep(&obj, repo, fd);
1795 		if (err)
1796 			return err;
1797 		obj_type = obj->type;
1798 		got_object_close(obj);
1799 		if (obj_type != GOT_OBJ_TYPE_TAG)
1800 			return got_error(GOT_ERR_OBJ_TYPE);
1801 
1802 		err = got_object_open_loose_fd(&fd, id, repo);
1803 		if (err)
1804 			return err;
1805 		err = read_tag_privsep(tag, fd, repo);
1806 	}
1807 
1808 	if (err == NULL) {
1809 		(*tag)->refcnt++;
1810 		err = got_repo_cache_tag(repo, id, *tag);
1811 	}
1812 done:
1813 	free(path_packfile);
1814 	return err;
1815 }
1816 
1817 const struct got_error *
1818 got_object_open_as_tag(struct got_tag_object **tag,
1819     struct got_repository *repo, struct got_object_id *id)
1820 {
1821 	*tag = got_repo_get_cached_tag(repo, id);
1822 	if (*tag != NULL) {
1823 		(*tag)->refcnt++;
1824 		return NULL;
1825 	}
1826 
1827 	return open_tag(tag, repo, id, 0);
1828 }
1829 
1830 const struct got_error *
1831 got_object_tag_open(struct got_tag_object **tag,
1832     struct got_repository *repo, struct got_object *obj)
1833 {
1834 	return open_tag(tag, repo, got_object_get_id(obj), 1);
1835 }
1836 
1837 const char *
1838 got_object_tag_get_name(struct got_tag_object *tag)
1839 {
1840 	return tag->tag;
1841 }
1842 
1843 int
1844 got_object_tag_get_object_type(struct got_tag_object *tag)
1845 {
1846 	return tag->obj_type;
1847 }
1848 
1849 struct got_object_id *
1850 got_object_tag_get_object_id(struct got_tag_object *tag)
1851 {
1852 	return &tag->id;
1853 }
1854 
1855 time_t
1856 got_object_tag_get_tagger_time(struct got_tag_object *tag)
1857 {
1858 	return tag->tagger_time;
1859 }
1860 
1861 time_t
1862 got_object_tag_get_tagger_gmtoff(struct got_tag_object *tag)
1863 {
1864 	return tag->tagger_gmtoff;
1865 }
1866 
1867 const char *
1868 got_object_tag_get_tagger(struct got_tag_object *tag)
1869 {
1870 	return tag->tagger;
1871 }
1872 
1873 const char *
1874 got_object_tag_get_message(struct got_tag_object *tag)
1875 {
1876 	return tag->tagmsg;
1877 }
1878 
1879 static struct got_tree_entry *
1880 find_entry_by_name(struct got_tree_object *tree, const char *name, size_t len)
1881 {
1882 	int i;
1883 
1884 	/* Note that tree entries are sorted in strncmp() order. */
1885 	for (i = 0; i < tree->nentries; i++) {
1886 		struct got_tree_entry *te = &tree->entries[i];
1887 		int cmp = strncmp(te->name, name, len);
1888 		if (cmp < 0)
1889 			continue;
1890 		if (cmp > 0)
1891 			break;
1892 		if (te->name[len] == '\0')
1893 			return te;
1894 	}
1895 	return NULL;
1896 }
1897 
1898 struct got_tree_entry *
1899 got_object_tree_find_entry(struct got_tree_object *tree, const char *name)
1900 {
1901 	return find_entry_by_name(tree, name, strlen(name));
1902 }
1903 
1904 const struct got_error *
1905 got_object_id_by_path(struct got_object_id **id, struct got_repository *repo,
1906     struct got_object_id *commit_id, const char *path)
1907 {
1908 	const struct got_error *err = NULL;
1909 	struct got_commit_object *commit = NULL;
1910 	struct got_tree_object *tree = NULL;
1911 	struct got_tree_entry *te = NULL;
1912 	const char *seg, *s;
1913 	size_t seglen;
1914 
1915 	*id = NULL;
1916 
1917 	err = got_object_open_as_commit(&commit, repo, commit_id);
1918 	if (err)
1919 		goto done;
1920 
1921 	/* Handle opening of root of commit's tree. */
1922 	if (got_path_is_root_dir(path)) {
1923 		*id = got_object_id_dup(commit->tree_id);
1924 		if (*id == NULL)
1925 			err = got_error_from_errno("got_object_id_dup");
1926 		goto done;
1927 	}
1928 
1929 	err = got_object_open_as_tree(&tree, repo, commit->tree_id);
1930 	if (err)
1931 		goto done;
1932 
1933 	s = path;
1934 	while (s[0] == '/')
1935 		s++;
1936 	seg = s;
1937 	seglen = 0;
1938 	while (*s) {
1939 		struct got_tree_object *next_tree;
1940 
1941 		if (*s != '/') {
1942 			s++;
1943 			seglen++;
1944 			if (*s)
1945 				continue;
1946 		}
1947 
1948 		te = find_entry_by_name(tree, seg, seglen);
1949 		if (te == NULL) {
1950 			err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
1951 			goto done;
1952 		}
1953 
1954 		if (*s == '\0')
1955 			break;
1956 
1957 		seg = s + 1;
1958 		seglen = 0;
1959 		s++;
1960 		if (*s) {
1961 			err = got_object_open_as_tree(&next_tree, repo,
1962 			    &te->id);
1963 			te = NULL;
1964 			if (err)
1965 				goto done;
1966 			got_object_tree_close(tree);
1967 			tree = next_tree;
1968 		}
1969 	}
1970 
1971 	if (te) {
1972 		*id = got_object_id_dup(&te->id);
1973 		if (*id == NULL)
1974 			return got_error_from_errno("got_object_id_dup");
1975 	} else
1976 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
1977 done:
1978 	if (commit)
1979 		got_object_commit_close(commit);
1980 	if (tree)
1981 		got_object_tree_close(tree);
1982 	return err;
1983 }
1984 
1985 /*
1986  * Normalize file mode bits to avoid false positive tree entry differences
1987  * in case tree entries have unexpected mode bits set.
1988  */
1989 static mode_t
1990 normalize_mode_for_comparison(mode_t mode)
1991 {
1992 	/*
1993 	 * For directories, the only relevant bit is the IFDIR bit.
1994 	 * This allows us to detect paths changing from a directory
1995 	 * to a file and vice versa.
1996 	 */
1997 	if (S_ISDIR(mode))
1998 		return mode & S_IFDIR;
1999 
2000 	/*
2001 	 * For symlinks, the only relevant bit is the IFLNK bit.
2002 	 * This allows us to detect paths changing from a symlinks
2003 	 * to a file or directory and vice versa.
2004 	 */
2005 	if (S_ISLNK(mode))
2006 		return mode & S_IFLNK;
2007 
2008 	/* For files, the only change we care about is the executable bit. */
2009 	return mode & S_IXUSR;
2010 }
2011 
2012 const struct got_error *
2013 got_object_tree_path_changed(int *changed,
2014     struct got_tree_object *tree01, struct got_tree_object *tree02,
2015     const char *path, struct got_repository *repo)
2016 {
2017 	const struct got_error *err = NULL;
2018 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
2019 	struct got_tree_entry *te1 = NULL, *te2 = NULL;
2020 	const char *seg, *s;
2021 	size_t seglen;
2022 
2023 	*changed = 0;
2024 
2025 	/* We not do support comparing the root path. */
2026 	if (got_path_is_root_dir(path))
2027 		return got_error_path(path, GOT_ERR_BAD_PATH);
2028 
2029 	tree1 = tree01;
2030 	tree2 = tree02;
2031 	s = path;
2032 	while (*s == '/')
2033 		s++;
2034 	seg = s;
2035 	seglen = 0;
2036 	while (*s) {
2037 		struct got_tree_object *next_tree1, *next_tree2;
2038 		mode_t mode1, mode2;
2039 
2040 		if (*s != '/') {
2041 			s++;
2042 			seglen++;
2043 			if (*s)
2044 				continue;
2045 		}
2046 
2047 		te1 = find_entry_by_name(tree1, seg, seglen);
2048 		if (te1 == NULL) {
2049 			err = got_error(GOT_ERR_NO_OBJ);
2050 			goto done;
2051 		}
2052 
2053 		if (tree2)
2054 			te2 = find_entry_by_name(tree2, seg, seglen);
2055 
2056 		if (te2) {
2057 			mode1 = normalize_mode_for_comparison(te1->mode);
2058 			mode2 = normalize_mode_for_comparison(te2->mode);
2059 			if (mode1 != mode2) {
2060 				*changed = 1;
2061 				goto done;
2062 			}
2063 
2064 			if (got_object_id_cmp(&te1->id, &te2->id) == 0) {
2065 				*changed = 0;
2066 				goto done;
2067 			}
2068 		}
2069 
2070 		if (*s == '\0') { /* final path element */
2071 			*changed = 1;
2072 			goto done;
2073 		}
2074 
2075 		seg = s + 1;
2076 		s++;
2077 		seglen = 0;
2078 		if (*s) {
2079 			err = got_object_open_as_tree(&next_tree1, repo,
2080 			    &te1->id);
2081 			te1 = NULL;
2082 			if (err)
2083 				goto done;
2084 			if (tree1 != tree01)
2085 				got_object_tree_close(tree1);
2086 			tree1 = next_tree1;
2087 
2088 			if (te2) {
2089 				err = got_object_open_as_tree(&next_tree2, repo,
2090 				    &te2->id);
2091 				te2 = NULL;
2092 				if (err)
2093 					goto done;
2094 				if (tree2 != tree02)
2095 					got_object_tree_close(tree2);
2096 				tree2 = next_tree2;
2097 			} else if (tree2) {
2098 				if (tree2 != tree02)
2099 					got_object_tree_close(tree2);
2100 				tree2 = NULL;
2101 			}
2102 		}
2103 	}
2104 done:
2105 	if (tree1 && tree1 != tree01)
2106 		got_object_tree_close(tree1);
2107 	if (tree2 && tree2 != tree02)
2108 		got_object_tree_close(tree2);
2109 	return err;
2110 }
2111 
2112 const struct got_error *
2113 got_object_tree_entry_dup(struct got_tree_entry **new_te,
2114     struct got_tree_entry *te)
2115 {
2116 	const struct got_error *err = NULL;
2117 
2118 	*new_te = calloc(1, sizeof(**new_te));
2119 	if (*new_te == NULL)
2120 		return got_error_from_errno("calloc");
2121 
2122 	(*new_te)->mode = te->mode;
2123 	memcpy((*new_te)->name, te->name, sizeof((*new_te)->name));
2124 	memcpy(&(*new_te)->id, &te->id, sizeof((*new_te)->id));
2125 	return err;
2126 }
2127 
2128 int
2129 got_object_tree_entry_is_submodule(struct got_tree_entry *te)
2130 {
2131 	return (te->mode & S_IFMT) == (S_IFDIR | S_IFLNK);
2132 }
2133 
2134 int
2135 got_object_tree_entry_is_symlink(struct got_tree_entry *te)
2136 {
2137 	/* S_IFDIR check avoids confusing symlinks with submodules. */
2138 	return ((te->mode & (S_IFDIR | S_IFLNK)) == S_IFLNK);
2139 }
2140 
2141 static const struct got_error *
2142 resolve_symlink(char **link_target, const char *path,
2143     struct got_object_id *commit_id, struct got_repository *repo)
2144 {
2145 	const struct got_error *err = NULL;
2146 	char buf[PATH_MAX];
2147 	char *name, *parent_path = NULL;
2148 	struct got_object_id *tree_obj_id = NULL;
2149 	struct got_tree_object *tree = NULL;
2150 	struct got_tree_entry *te = NULL;
2151 
2152 	*link_target = NULL;
2153 
2154 	if (strlcpy(buf, path, sizeof(buf)) >= sizeof(buf))
2155 		return got_error(GOT_ERR_NO_SPACE);
2156 
2157 	name = basename(buf);
2158 	if (name == NULL)
2159 		return got_error_from_errno2("basename", path);
2160 
2161 	err = got_path_dirname(&parent_path, path);
2162 	if (err)
2163 		return err;
2164 
2165 	err = got_object_id_by_path(&tree_obj_id, repo, commit_id,
2166 	    parent_path);
2167 	if (err) {
2168 		if (err->code == GOT_ERR_NO_TREE_ENTRY) {
2169 			/* Display the complete path in error message. */
2170 			err = got_error_path(path, err->code);
2171 		}
2172 		goto done;
2173 	}
2174 
2175 	err = got_object_open_as_tree(&tree, repo, tree_obj_id);
2176 	if (err)
2177 		goto done;
2178 
2179 	te = got_object_tree_find_entry(tree, name);
2180 	if (te == NULL) {
2181 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
2182 		goto done;
2183 	}
2184 
2185 	if (got_object_tree_entry_is_symlink(te)) {
2186 		err = got_tree_entry_get_symlink_target(link_target, te, repo);
2187 		if (err)
2188 			goto done;
2189 		if (!got_path_is_absolute(*link_target)) {
2190 			char *abspath;
2191 			if (asprintf(&abspath, "%s/%s", parent_path,
2192 			    *link_target) == -1) {
2193 				err = got_error_from_errno("asprintf");
2194 				goto done;
2195 			}
2196 			free(*link_target);
2197 			*link_target = malloc(PATH_MAX);
2198 			if (*link_target == NULL) {
2199 				err = got_error_from_errno("malloc");
2200 				goto done;
2201 			}
2202 			err = got_canonpath(abspath, *link_target, PATH_MAX);
2203 			free(abspath);
2204 			if (err)
2205 				goto done;
2206 		}
2207 	}
2208 done:
2209 	free(tree_obj_id);
2210 	if (tree)
2211 		got_object_tree_close(tree);
2212 	if (err) {
2213 		free(*link_target);
2214 		*link_target = NULL;
2215 	}
2216 	return err;
2217 }
2218 
2219 const struct got_error *
2220 got_object_resolve_symlinks(char **link_target, const char *path,
2221     struct got_object_id *commit_id, struct got_repository *repo)
2222 {
2223 	const struct got_error *err = NULL;
2224 	char *next_target = NULL;
2225 	int max_recursion = 40; /* matches Git */
2226 
2227 	*link_target = NULL;
2228 
2229 	do {
2230 		err = resolve_symlink(&next_target,
2231 		    *link_target ? *link_target : path, commit_id, repo);
2232 		if (err)
2233 			break;
2234 		if (next_target) {
2235 			free(*link_target);
2236 			if (--max_recursion == 0) {
2237 				err = got_error_path(path, GOT_ERR_RECURSION);
2238 				*link_target = NULL;
2239 				break;
2240 			}
2241 			*link_target = next_target;
2242 		}
2243 	} while (next_target);
2244 
2245 	return err;
2246 }
2247 
2248 const struct got_error *
2249 got_traverse_packed_commits(struct got_object_id_queue *traversed_commits,
2250     struct got_object_id *commit_id, const char *path,
2251     struct got_repository *repo)
2252 {
2253 	const struct got_error *err = NULL;
2254 	struct got_pack *pack = NULL;
2255 	struct got_packidx *packidx = NULL;
2256 	char *path_packfile = NULL;
2257 	struct got_commit_object *changed_commit = NULL;
2258 	struct got_object_id *changed_commit_id = NULL;
2259 	int idx;
2260 
2261 	err = got_repo_search_packidx(&packidx, &idx, repo, commit_id);
2262 	if (err) {
2263 		if (err->code != GOT_ERR_NO_OBJ)
2264 			return err;
2265 		return NULL;
2266 	}
2267 
2268 	err = got_packidx_get_packfile_path(&path_packfile,
2269 	    packidx->path_packidx);
2270 	if (err)
2271 		return err;
2272 
2273 	pack = got_repo_get_cached_pack(repo, path_packfile);
2274 	if (pack == NULL) {
2275 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
2276 		if (err)
2277 			goto done;
2278 	}
2279 
2280 	if (pack->privsep_child == NULL) {
2281 		err = start_pack_privsep_child(pack, packidx);
2282 		if (err)
2283 			goto done;
2284 	}
2285 
2286 	err = got_privsep_send_commit_traversal_request(
2287 	    pack->privsep_child->ibuf, commit_id, idx, path);
2288 	if (err)
2289 		goto done;
2290 
2291 	err = got_privsep_recv_traversed_commits(&changed_commit,
2292 	    &changed_commit_id, traversed_commits, pack->privsep_child->ibuf);
2293 	if (err)
2294 		goto done;
2295 
2296 	if (changed_commit) {
2297 		/*
2298 		 * Cache the commit in which the path was changed.
2299 		 * This commit might be opened again soon.
2300 		 */
2301 		changed_commit->refcnt++;
2302 		err = got_repo_cache_commit(repo, changed_commit_id,
2303 		    changed_commit);
2304 		got_object_commit_close(changed_commit);
2305 	}
2306 done:
2307 	free(path_packfile);
2308 	free(changed_commit_id);
2309 	return err;
2310 }