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 static const struct got_error *
129 open_loose_object(int *fd, struct got_object_id *id,
130     struct got_repository *repo)
131 {
132 	const struct got_error *err = NULL;
133 	char *path;
134 
135 	err = got_object_get_path(&path, id, repo);
136 	if (err)
137 		return err;
138 	*fd = open(path, O_RDONLY | O_NOFOLLOW);
139 	if (*fd == -1) {
140 		err = got_error_from_errno2("open", path);
141 		goto done;
142 	}
143 done:
144 	free(path);
145 	return err;
146 }
147 
148 static const struct got_error *
149 get_packfile_path(char **path_packfile, struct got_packidx *packidx)
150 {
151 	size_t size;
152 
153 	/* Packfile path contains ".pack" instead of ".idx", so add one byte. */
154 	size = strlen(packidx->path_packidx) + 2;
155 	if (size < GOT_PACKFILE_NAMELEN + 1)
156 		return got_error_path(packidx->path_packidx, GOT_ERR_BAD_PATH);
157 
158 	*path_packfile = malloc(size);
159 	if (*path_packfile == NULL)
160 		return got_error_from_errno("malloc");
161 
162 	/* Copy up to and excluding ".idx". */
163 	if (strlcpy(*path_packfile, packidx->path_packidx,
164 	    size - strlen(GOT_PACKIDX_SUFFIX) - 1) >= size)
165 		return got_error(GOT_ERR_NO_SPACE);
166 
167 	if (strlcat(*path_packfile, GOT_PACKFILE_SUFFIX, size) >= size)
168 		return got_error(GOT_ERR_NO_SPACE);
169 
170 	return NULL;
171 }
172 
173 static const struct got_error *
174 request_packed_object(struct got_object **obj, struct got_pack *pack, int idx,
175     struct got_object_id *id)
176 {
177 	const struct got_error *err = NULL;
178 	struct imsgbuf *ibuf = pack->privsep_child->ibuf;
179 
180 	err = got_privsep_send_packed_obj_req(ibuf, idx, id);
181 	if (err)
182 		return err;
183 
184 	err = got_privsep_recv_obj(obj, ibuf);
185 	if (err)
186 		return err;
187 
188 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
189 
190 	return NULL;
191 }
192 
193 static const struct got_error *
194 request_packed_object_raw(uint8_t **outbuf, off_t *size, size_t *hdrlen,
195     int outfd, struct got_pack *pack, int idx, struct got_object_id *id)
196 {
197 	const struct got_error *err = NULL;
198 	struct imsgbuf *ibuf = pack->privsep_child->ibuf;
199 	int outfd_child;
200 	int basefd, accumfd; /* temporary files for delta application */
201 
202 	basefd = got_opentempfd();
203 	if (basefd == -1)
204 		return got_error_from_errno("got_opentempfd");
205 
206 	accumfd = got_opentempfd();
207 	if (accumfd == -1) {
208 		close(basefd);
209 		return got_error_from_errno("got_opentempfd");
210 	}
211 
212 	outfd_child = dup(outfd);
213 	if (outfd_child == -1) {
214 		err = got_error_from_errno("dup");
215 		close(basefd);
216 		close(accumfd);
217 		return err;
218 	}
219 
220 	err = got_privsep_send_packed_raw_obj_req(ibuf, idx, id);
221 	if (err) {
222 		close(basefd);
223 		close(accumfd);
224 		close(outfd_child);
225 		return err;
226 	}
227 
228 	err = got_privsep_send_raw_obj_outfd(ibuf, outfd_child);
229 	if (err) {
230 		close(basefd);
231 		close(accumfd);
232 		return err;
233 	}
234 
235 
236 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
237 	    basefd);
238 	if (err) {
239 		close(accumfd);
240 		return err;
241 	}
242 
243 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
244 	    accumfd);
245 	if (err)
246 		return err;
247 
248 	err = got_privsep_recv_raw_obj(outbuf, size, hdrlen, ibuf);
249 	if (err)
250 		return err;
251 
252 	return NULL;
253 }
254 
255 static void
256 set_max_datasize(void)
257 {
258 	struct rlimit rl;
259 
260 	if (getrlimit(RLIMIT_DATA, &rl) != 0)
261 		return;
262 
263 	rl.rlim_cur = rl.rlim_max;
264 	setrlimit(RLIMIT_DATA, &rl);
265 }
266 
267 static const struct got_error *
268 start_pack_privsep_child(struct got_pack *pack, struct got_packidx *packidx)
269 {
270 	const struct got_error *err = NULL;
271 	int imsg_fds[2];
272 	pid_t pid;
273 	struct imsgbuf *ibuf;
274 
275 	ibuf = calloc(1, sizeof(*ibuf));
276 	if (ibuf == NULL)
277 		return got_error_from_errno("calloc");
278 
279 	pack->privsep_child = calloc(1, sizeof(*pack->privsep_child));
280 	if (pack->privsep_child == NULL) {
281 		err = got_error_from_errno("calloc");
282 		free(ibuf);
283 		return err;
284 	}
285 
286 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
287 		err = got_error_from_errno("socketpair");
288 		goto done;
289 	}
290 
291 	pid = fork();
292 	if (pid == -1) {
293 		err = got_error_from_errno("fork");
294 		goto done;
295 	} else if (pid == 0) {
296 		set_max_datasize();
297 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PACK,
298 		    pack->path_packfile);
299 		/* not reached */
300 	}
301 
302 	if (close(imsg_fds[1]) == -1)
303 		return got_error_from_errno("close");
304 	pack->privsep_child->imsg_fd = imsg_fds[0];
305 	pack->privsep_child->pid = pid;
306 	imsg_init(ibuf, imsg_fds[0]);
307 	pack->privsep_child->ibuf = ibuf;
308 
309 	err = got_privsep_init_pack_child(ibuf, pack, packidx);
310 	if (err) {
311 		const struct got_error *child_err;
312 		err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
313 		child_err = got_privsep_wait_for_child(
314 		    pack->privsep_child->pid);
315 		if (child_err && err == NULL)
316 			err = child_err;
317 	}
318 done:
319 	if (err) {
320 		free(ibuf);
321 		free(pack->privsep_child);
322 		pack->privsep_child = NULL;
323 	}
324 	return err;
325 }
326 
327 static const struct got_error *
328 read_packed_object_privsep(struct got_object **obj,
329     struct got_repository *repo, struct got_pack *pack,
330     struct got_packidx *packidx, int idx, struct got_object_id *id)
331 {
332 	const struct got_error *err = NULL;
333 
334 	if (pack->privsep_child == NULL) {
335 		err = start_pack_privsep_child(pack, packidx);
336 		if (err)
337 			return err;
338 	}
339 
340 	return request_packed_object(obj, pack, idx, id);
341 }
342 
343 static const struct got_error *
344 read_packed_object_raw_privsep(uint8_t **outbuf, off_t *size, size_t *hdrlen,
345     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
346     struct got_object_id *id)
347 {
348 	const struct got_error *err = NULL;
349 
350 	if (pack->privsep_child == NULL) {
351 		err = start_pack_privsep_child(pack, packidx);
352 		if (err)
353 			return err;
354 	}
355 
356 	return request_packed_object_raw(outbuf, size, hdrlen, outfd, pack,
357 	    idx, id);
358 }
359 
360 static const struct got_error *
361 open_packed_object(struct got_object **obj, struct got_object_id *id,
362     struct got_repository *repo)
363 {
364 	const struct got_error *err = NULL;
365 	struct got_pack *pack = NULL;
366 	struct got_packidx *packidx = NULL;
367 	int idx;
368 	char *path_packfile;
369 
370 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
371 	if (err)
372 		return err;
373 
374 	err = get_packfile_path(&path_packfile, packidx);
375 	if (err)
376 		return err;
377 
378 	pack = got_repo_get_cached_pack(repo, path_packfile);
379 	if (pack == NULL) {
380 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
381 		if (err)
382 			goto done;
383 	}
384 
385 	err = read_packed_object_privsep(obj, repo, pack, packidx, idx, id);
386 	if (err)
387 		goto done;
388 done:
389 	free(path_packfile);
390 	return err;
391 }
392 
393 static const struct got_error *
394 request_object(struct got_object **obj, struct got_repository *repo, int fd)
395 {
396 	const struct got_error *err = NULL;
397 	struct imsgbuf *ibuf;
398 
399 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf;
400 
401 	err = got_privsep_send_obj_req(ibuf, fd);
402 	if (err)
403 		return err;
404 
405 	return got_privsep_recv_obj(obj, ibuf);
406 }
407 
408 static const struct got_error *
409 request_raw_object(uint8_t **outbuf, off_t *size, size_t *hdrlen, int outfd,
410     struct got_repository *repo, int infd)
411 {
412 	const struct got_error *err = NULL;
413 	struct imsgbuf *ibuf;
414 	int outfd_child;
415 
416 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf;
417 
418 	outfd_child = dup(outfd);
419 	if (outfd_child == -1)
420 		return got_error_from_errno("dup");
421 
422 	err = got_privsep_send_raw_obj_req(ibuf, infd);
423 	if (err)
424 		return err;
425 
426 	err = got_privsep_send_raw_obj_outfd(ibuf, outfd_child);
427 	if (err)
428 		return err;
429 
430 	return got_privsep_recv_raw_obj(outbuf, size, hdrlen, ibuf);
431 }
432 
433 static const struct got_error *
434 start_read_object_child(struct got_repository *repo)
435 {
436 	const struct got_error *err = NULL;
437 	int imsg_fds[2];
438 	pid_t pid;
439 	struct imsgbuf *ibuf;
440 
441 	ibuf = calloc(1, sizeof(*ibuf));
442 	if (ibuf == NULL)
443 		return got_error_from_errno("calloc");
444 
445 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
446 		err = got_error_from_errno("socketpair");
447 		free(ibuf);
448 		return err;
449 	}
450 
451 	pid = fork();
452 	if (pid == -1) {
453 		err = got_error_from_errno("fork");
454 		free(ibuf);
455 		return err;
456 	}
457 	else if (pid == 0) {
458 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_OBJECT,
459 		    repo->path);
460 		/* not reached */
461 	}
462 
463 	if (close(imsg_fds[1]) == -1) {
464 		err = got_error_from_errno("close");
465 		free(ibuf);
466 		return err;
467 	}
468 
469 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd =
470 	    imsg_fds[0];
471 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].pid = pid;
472 	imsg_init(ibuf, imsg_fds[0]);
473 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf = ibuf;
474 
475 	return NULL;
476 }
477 
478 static const struct got_error *
479 read_object_header_privsep(struct got_object **obj, struct got_repository *repo,
480     int obj_fd)
481 {
482 	const struct got_error *err;
483 
484 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd != -1)
485 		return request_object(obj, repo, obj_fd);
486 
487 	err = start_read_object_child(repo);
488 	if (err)
489 		return err;
490 
491 	return request_object(obj, repo, obj_fd);
492 }
493 
494 static const struct got_error *
495 read_object_raw_privsep(uint8_t **outbuf, off_t *size, size_t *hdrlen,
496     int outfd, struct got_repository *repo, int obj_fd)
497 {
498 	const struct got_error *err;
499 
500 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd != -1)
501 		return request_raw_object(outbuf, size, hdrlen, outfd, repo,
502 		    obj_fd);
503 
504 	err = start_read_object_child(repo);
505 	if (err)
506 		return err;
507 
508 	return request_raw_object(outbuf, size, hdrlen, outfd, repo, obj_fd);
509 }
510 
511 const struct got_error *
512 got_object_open(struct got_object **obj, struct got_repository *repo,
513     struct got_object_id *id)
514 {
515 	const struct got_error *err = NULL;
516 	char *path;
517 	int fd;
518 
519 	*obj = got_repo_get_cached_object(repo, id);
520 	if (*obj != NULL) {
521 		(*obj)->refcnt++;
522 		return NULL;
523 	}
524 
525 	err = open_packed_object(obj, id, repo);
526 	if (err && err->code != GOT_ERR_NO_OBJ)
527 		return err;
528 	if (*obj) {
529 		(*obj)->refcnt++;
530 		return got_repo_cache_object(repo, id, *obj);
531 	}
532 
533 	err = got_object_get_path(&path, id, repo);
534 	if (err)
535 		return err;
536 
537 	fd = open(path, O_RDONLY | O_NOFOLLOW);
538 	if (fd == -1) {
539 		if (errno == ENOENT)
540 			err = got_error_no_obj(id);
541 		else
542 			err = got_error_from_errno2("open", path);
543 		goto done;
544 	} else {
545 		err = read_object_header_privsep(obj, repo, fd);
546 		if (err)
547 			goto done;
548 		memcpy((*obj)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
549 	}
550 
551 	(*obj)->refcnt++;
552 	err = got_repo_cache_object(repo, id, *obj);
553 done:
554 	free(path);
555 	return err;
556 }
557 
558 const struct got_error *
559 got_object_raw_open(struct got_raw_object **obj, struct got_repository *repo,
560     struct got_object_id *id, size_t blocksize)
561 {
562 	const struct got_error *err = NULL;
563 	struct got_packidx *packidx = NULL;
564 	int idx;
565 	uint8_t *outbuf = NULL;
566 	int outfd = -1;
567 	off_t size = 0;
568 	size_t hdrlen = 0;
569 	char *path_packfile = NULL;
570 
571 	*obj = NULL;
572 
573 	outfd = got_opentempfd();
574 	if (outfd == -1)
575 		return got_error_from_errno("got_opentempfd");
576 
577 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
578 	if (err == NULL) {
579 		struct got_pack *pack = NULL;
580 
581 		err = get_packfile_path(&path_packfile, packidx);
582 		if (err)
583 			goto done;
584 
585 		pack = got_repo_get_cached_pack(repo, path_packfile);
586 		if (pack == NULL) {
587 			err = got_repo_cache_pack(&pack, repo, path_packfile,
588 			    packidx);
589 			if (err)
590 				goto done;
591 		}
592 		err = read_packed_object_raw_privsep(&outbuf, &size, &hdrlen,
593 		    outfd, pack, packidx, idx, id);
594 	} else if (err->code == GOT_ERR_NO_OBJ) {
595 		int fd;
596 
597 		err = open_loose_object(&fd, id, repo);
598 		if (err)
599 			goto done;
600 		err = read_object_raw_privsep(&outbuf, &size, &hdrlen, outfd,
601 		    repo, fd);
602 	}
603 
604 	if (hdrlen > size) {
605 		err = got_error(GOT_ERR_BAD_OBJ_HDR);
606 		goto done;
607 	}
608 
609 	*obj = calloc(1, sizeof(**obj));
610 	if (*obj == NULL) {
611 		err = got_error_from_errno("calloc");
612 		goto done;
613 	}
614 
615 	(*obj)->read_buf = malloc(blocksize);
616 	if ((*obj)->read_buf == NULL) {
617 		err = got_error_from_errno("malloc");
618 		goto done;
619 	}
620 
621 	if (outbuf) {
622 		if (close(outfd) == -1) {
623 			err = got_error_from_errno("close");
624 			goto done;
625 		}
626 		outfd = -1;
627 		(*obj)->f = fmemopen(outbuf, hdrlen + size, "r");
628 		if ((*obj)->f == NULL) {
629 			err = got_error_from_errno("fdopen");
630 			goto done;
631 		}
632 		(*obj)->data = outbuf;
633 	} else {
634 		struct stat sb;
635 		if (fstat(outfd, &sb) == -1) {
636 			err = got_error_from_errno("fstat");
637 			goto done;
638 		}
639 
640 		if (sb.st_size != size) {
641 			err = got_error(GOT_ERR_PRIVSEP_LEN);
642 			goto done;
643 		}
644 
645 		(*obj)->f = fdopen(outfd, "r");
646 		if ((*obj)->f == NULL) {
647 			err = got_error_from_errno("fdopen");
648 			goto done;
649 		}
650 		outfd = -1;
651 		(*obj)->data = NULL;
652 	}
653 	(*obj)->hdrlen = hdrlen;
654 	(*obj)->size = size;
655 	(*obj)->blocksize = blocksize;
656 done:
657 	free(path_packfile);
658 	if (err) {
659 		if (*obj) {
660 			got_object_raw_close(*obj);
661 			*obj = NULL;
662 		}
663 		if (outfd != -1)
664 			close(outfd);
665 		free(outbuf);
666 	}
667 	return err;
668 }
669 
670 void
671 got_object_raw_rewind(struct got_raw_object *obj)
672 {
673 	if (obj->f)
674 		rewind(obj->f);
675 }
676 
677 size_t
678 got_object_raw_get_hdrlen(struct got_raw_object *obj)
679 {
680 	return obj->hdrlen;
681 }
682 
683 const uint8_t *
684 got_object_raw_get_read_buf(struct got_raw_object *obj)
685 {
686 	return obj->read_buf;
687 }
688 
689 const struct got_error *
690 got_object_raw_read_block(size_t *outlenp, struct got_raw_object *obj)
691 {
692 	size_t n;
693 
694 	n = fread(obj->read_buf, 1, obj->blocksize, obj->f);
695 	if (n == 0 && ferror(obj->f))
696 		return got_ferror(obj->f, GOT_ERR_IO);
697 	*outlenp = n;
698 	return NULL;
699 }
700 
701 const struct got_error *
702 got_object_raw_close(struct got_raw_object *obj)
703 {
704 	const struct got_error *err = NULL;
705 
706 	free(obj->read_buf);
707 	if (obj->f != NULL && fclose(obj->f) == EOF && err == NULL)
708 		err = got_error_from_errno("fclose");
709 	free(obj->data);
710 	free(obj);
711 	return err;
712 }
713 
714 const struct got_error *
715 got_object_open_by_id_str(struct got_object **obj, struct got_repository *repo,
716     const char *id_str)
717 {
718 	struct got_object_id id;
719 
720 	if (!got_parse_sha1_digest(id.sha1, id_str))
721 		return got_error_path(id_str, GOT_ERR_BAD_OBJ_ID_STR);
722 
723 	return got_object_open(obj, repo, &id);
724 }
725 
726 const struct got_error *
727 got_object_resolve_id_str(struct got_object_id **id,
728     struct got_repository *repo, const char *id_str)
729 {
730 	const struct got_error *err = NULL;
731 	struct got_object *obj;
732 
733 	err = got_object_open_by_id_str(&obj, repo, id_str);
734 	if (err)
735 		return err;
736 
737 	*id = got_object_id_dup(got_object_get_id(obj));
738 	got_object_close(obj);
739 	if (*id == NULL)
740 		return got_error_from_errno("got_object_id_dup");
741 
742 	return NULL;
743 }
744 
745 static const struct got_error *
746 request_packed_commit(struct got_commit_object **commit, struct got_pack *pack,
747     int pack_idx, struct got_object_id *id)
748 {
749 	const struct got_error *err = NULL;
750 
751 	err = got_privsep_send_commit_req(pack->privsep_child->ibuf, -1, id,
752 	    pack_idx);
753 	if (err)
754 		return err;
755 
756 	err = got_privsep_recv_commit(commit, pack->privsep_child->ibuf);
757 	if (err)
758 		return err;
759 
760 	(*commit)->flags |= GOT_COMMIT_FLAG_PACKED;
761 	return NULL;
762 }
763 
764 static const struct got_error *
765 read_packed_commit_privsep(struct got_commit_object **commit,
766     struct got_pack *pack, struct got_packidx *packidx, int idx,
767     struct got_object_id *id)
768 {
769 	const struct got_error *err = NULL;
770 
771 	if (pack->privsep_child)
772 		return request_packed_commit(commit, pack, idx, id);
773 
774 	err = start_pack_privsep_child(pack, packidx);
775 	if (err)
776 		return err;
777 
778 	return request_packed_commit(commit, pack, idx, id);
779 }
780 
781 static const struct got_error *
782 request_commit(struct got_commit_object **commit, struct got_repository *repo,
783     int fd)
784 {
785 	const struct got_error *err = NULL;
786 	struct imsgbuf *ibuf;
787 
788 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf;
789 
790 	err = got_privsep_send_commit_req(ibuf, fd, NULL, -1);
791 	if (err)
792 		return err;
793 
794 	return got_privsep_recv_commit(commit, ibuf);
795 }
796 
797 static const struct got_error *
798 read_commit_privsep(struct got_commit_object **commit, int obj_fd,
799     struct got_repository *repo)
800 {
801 	const struct got_error *err;
802 	int imsg_fds[2];
803 	pid_t pid;
804 	struct imsgbuf *ibuf;
805 
806 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd != -1)
807 		return request_commit(commit, repo, obj_fd);
808 
809 	ibuf = calloc(1, sizeof(*ibuf));
810 	if (ibuf == NULL)
811 		return got_error_from_errno("calloc");
812 
813 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
814 		err = got_error_from_errno("socketpair");
815 		free(ibuf);
816 		return err;
817 	}
818 
819 	pid = fork();
820 	if (pid == -1) {
821 		err = got_error_from_errno("fork");
822 		free(ibuf);
823 		return err;
824 	}
825 	else if (pid == 0) {
826 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_COMMIT,
827 		    repo->path);
828 		/* not reached */
829 	}
830 
831 	if (close(imsg_fds[1]) == -1) {
832 		err = got_error_from_errno("close");
833 		free(ibuf);
834 		return err;
835 	}
836 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd =
837 	    imsg_fds[0];
838 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].pid = pid;
839 	imsg_init(ibuf, imsg_fds[0]);
840 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf = ibuf;
841 
842 	return request_commit(commit, repo, obj_fd);
843 }
844 
845 
846 static const struct got_error *
847 open_commit(struct got_commit_object **commit,
848     struct got_repository *repo, struct got_object_id *id, int check_cache)
849 {
850 	const struct got_error *err = NULL;
851 	struct got_packidx *packidx = NULL;
852 	int idx;
853 	char *path_packfile = NULL;
854 
855 	if (check_cache) {
856 		*commit = got_repo_get_cached_commit(repo, id);
857 		if (*commit != NULL) {
858 			(*commit)->refcnt++;
859 			return NULL;
860 		}
861 	} else
862 		*commit = NULL;
863 
864 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
865 	if (err == NULL) {
866 		struct got_pack *pack = NULL;
867 
868 		err = get_packfile_path(&path_packfile, packidx);
869 		if (err)
870 			return err;
871 
872 		pack = got_repo_get_cached_pack(repo, path_packfile);
873 		if (pack == NULL) {
874 			err = got_repo_cache_pack(&pack, repo, path_packfile,
875 			    packidx);
876 			if (err)
877 				goto done;
878 		}
879 		err = read_packed_commit_privsep(commit, pack,
880 		    packidx, idx, id);
881 	} else if (err->code == GOT_ERR_NO_OBJ) {
882 		int fd;
883 
884 		err = open_loose_object(&fd, id, repo);
885 		if (err)
886 			return err;
887 		err = read_commit_privsep(commit, fd, repo);
888 	}
889 
890 	if (err == NULL) {
891 		(*commit)->refcnt++;
892 		err = got_repo_cache_commit(repo, id, *commit);
893 	}
894 done:
895 	free(path_packfile);
896 	return err;
897 }
898 
899 const struct got_error *
900 got_object_open_as_commit(struct got_commit_object **commit,
901     struct got_repository *repo, struct got_object_id *id)
902 {
903 	*commit = got_repo_get_cached_commit(repo, id);
904 	if (*commit != NULL) {
905 		(*commit)->refcnt++;
906 		return NULL;
907 	}
908 
909 	return open_commit(commit, repo, id, 0);
910 }
911 
912 const struct got_error *
913 got_object_commit_open(struct got_commit_object **commit,
914     struct got_repository *repo, struct got_object *obj)
915 {
916 	return open_commit(commit, repo, got_object_get_id(obj), 1);
917 }
918 
919 const struct got_error *
920 got_object_qid_alloc(struct got_object_qid **qid, struct got_object_id *id)
921 {
922 	const struct got_error *err = NULL;
923 
924 	*qid = calloc(1, sizeof(**qid));
925 	if (*qid == NULL)
926 		return got_error_from_errno("calloc");
927 
928 	(*qid)->id = got_object_id_dup(id);
929 	if ((*qid)->id == NULL) {
930 		err = got_error_from_errno("got_object_id_dup");
931 		got_object_qid_free(*qid);
932 		*qid = NULL;
933 		return err;
934 	}
935 
936 	return NULL;
937 }
938 
939 static const struct got_error *
940 request_packed_tree(struct got_tree_object **tree, struct got_pack *pack,
941     int pack_idx, struct got_object_id *id)
942 {
943 	const struct got_error *err = NULL;
944 
945 	err = got_privsep_send_tree_req(pack->privsep_child->ibuf, -1, id,
946 	    pack_idx);
947 	if (err)
948 		return err;
949 
950 	return got_privsep_recv_tree(tree, pack->privsep_child->ibuf);
951 }
952 
953 static const struct got_error *
954 read_packed_tree_privsep(struct got_tree_object **tree,
955     struct got_pack *pack, struct got_packidx *packidx, int idx,
956     struct got_object_id *id)
957 {
958 	const struct got_error *err = NULL;
959 
960 	if (pack->privsep_child)
961 		return request_packed_tree(tree, pack, idx, id);
962 
963 	err = start_pack_privsep_child(pack, packidx);
964 	if (err)
965 		return err;
966 
967 	return request_packed_tree(tree, pack, idx, id);
968 }
969 
970 static const struct got_error *
971 request_tree(struct got_tree_object **tree, struct got_repository *repo,
972     int fd)
973 {
974 	const struct got_error *err = NULL;
975 	struct imsgbuf *ibuf;
976 
977 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf;
978 
979 	err = got_privsep_send_tree_req(ibuf, fd, NULL, -1);
980 	if (err)
981 		return err;
982 
983 	return got_privsep_recv_tree(tree, ibuf);
984 }
985 
986 const struct got_error *
987 read_tree_privsep(struct got_tree_object **tree, int obj_fd,
988     struct got_repository *repo)
989 {
990 	const struct got_error *err;
991 	int imsg_fds[2];
992 	pid_t pid;
993 	struct imsgbuf *ibuf;
994 
995 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd != -1)
996 		return request_tree(tree, repo, obj_fd);
997 
998 	ibuf = calloc(1, sizeof(*ibuf));
999 	if (ibuf == NULL)
1000 		return got_error_from_errno("calloc");
1001 
1002 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1003 		err = got_error_from_errno("socketpair");
1004 		free(ibuf);
1005 		return err;
1006 	}
1007 
1008 	pid = fork();
1009 	if (pid == -1) {
1010 		err = got_error_from_errno("fork");
1011 		free(ibuf);
1012 		return err;
1013 	}
1014 	else if (pid == 0) {
1015 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TREE,
1016 		    repo->path);
1017 		/* not reached */
1018 	}
1019 
1020 	if (close(imsg_fds[1]) == -1) {
1021 		err = got_error_from_errno("close");
1022 		free(ibuf);
1023 		return err;
1024 	}
1025 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd =
1026 	    imsg_fds[0];
1027 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].pid = pid;
1028 	imsg_init(ibuf, imsg_fds[0]);
1029 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf = ibuf;
1030 
1031 
1032 	return request_tree(tree, repo, obj_fd);
1033 }
1034 
1035 static const struct got_error *
1036 open_tree(struct got_tree_object **tree, struct got_repository *repo,
1037     struct got_object_id *id, int check_cache)
1038 {
1039 	const struct got_error *err = NULL;
1040 	struct got_packidx *packidx = NULL;
1041 	int idx;
1042 	char *path_packfile = NULL;
1043 
1044 	if (check_cache) {
1045 		*tree = got_repo_get_cached_tree(repo, id);
1046 		if (*tree != NULL) {
1047 			(*tree)->refcnt++;
1048 			return NULL;
1049 		}
1050 	} else
1051 		*tree = NULL;
1052 
1053 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1054 	if (err == NULL) {
1055 		struct got_pack *pack = NULL;
1056 
1057 		err = get_packfile_path(&path_packfile, packidx);
1058 		if (err)
1059 			return err;
1060 
1061 		pack = got_repo_get_cached_pack(repo, path_packfile);
1062 		if (pack == NULL) {
1063 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1064 			    packidx);
1065 			if (err)
1066 				goto done;
1067 		}
1068 		err = read_packed_tree_privsep(tree, pack,
1069 		    packidx, idx, id);
1070 	} else if (err->code == GOT_ERR_NO_OBJ) {
1071 		int fd;
1072 
1073 		err = open_loose_object(&fd, id, repo);
1074 		if (err)
1075 			return err;
1076 		err = read_tree_privsep(tree, fd, repo);
1077 	}
1078 
1079 	if (err == NULL) {
1080 		(*tree)->refcnt++;
1081 		err = got_repo_cache_tree(repo, id, *tree);
1082 	}
1083 done:
1084 	free(path_packfile);
1085 	return err;
1086 }
1087 
1088 const struct got_error *
1089 got_object_open_as_tree(struct got_tree_object **tree,
1090     struct got_repository *repo, struct got_object_id *id)
1091 {
1092 	*tree = got_repo_get_cached_tree(repo, id);
1093 	if (*tree != NULL) {
1094 		(*tree)->refcnt++;
1095 		return NULL;
1096 	}
1097 
1098 	return open_tree(tree, repo, id, 0);
1099 }
1100 
1101 const struct got_error *
1102 got_object_tree_open(struct got_tree_object **tree,
1103     struct got_repository *repo, struct got_object *obj)
1104 {
1105 	return open_tree(tree, repo, got_object_get_id(obj), 1);
1106 }
1107 
1108 int
1109 got_object_tree_get_nentries(struct got_tree_object *tree)
1110 {
1111 	return tree->nentries;
1112 }
1113 
1114 struct got_tree_entry *
1115 got_object_tree_get_first_entry(struct got_tree_object *tree)
1116 {
1117 	return got_object_tree_get_entry(tree, 0);
1118 }
1119 
1120 struct got_tree_entry *
1121 got_object_tree_get_last_entry(struct got_tree_object *tree)
1122 {
1123 	return got_object_tree_get_entry(tree, tree->nentries - 1);
1124 }
1125 
1126 struct got_tree_entry *
1127 got_object_tree_get_entry(struct got_tree_object *tree, int i)
1128 {
1129 	if (i < 0 || i >= tree->nentries)
1130 		return NULL;
1131 	return &tree->entries[i];
1132 }
1133 
1134 mode_t
1135 got_tree_entry_get_mode(struct got_tree_entry *te)
1136 {
1137 	return te->mode;
1138 }
1139 
1140 const char *
1141 got_tree_entry_get_name(struct got_tree_entry *te)
1142 {
1143 	return &te->name[0];
1144 }
1145 
1146 struct got_object_id *
1147 got_tree_entry_get_id(struct got_tree_entry *te)
1148 {
1149 	return &te->id;
1150 }
1151 
1152 const struct got_error *
1153 got_object_blob_read_to_str(char **s, struct got_blob_object *blob)
1154 {
1155 	const struct got_error *err = NULL;
1156 	size_t len, totlen, hdrlen, offset;
1157 
1158 	*s = NULL;
1159 
1160 	hdrlen = got_object_blob_get_hdrlen(blob);
1161 	totlen = 0;
1162 	offset = 0;
1163 	do {
1164 		char *p;
1165 
1166 		err = got_object_blob_read_block(&len, blob);
1167 		if (err)
1168 			return err;
1169 
1170 		if (len == 0)
1171 			break;
1172 
1173 		totlen += len - hdrlen;
1174 		p = realloc(*s, totlen + 1);
1175 		if (p == NULL) {
1176 			err = got_error_from_errno("realloc");
1177 			free(*s);
1178 			*s = NULL;
1179 			return err;
1180 		}
1181 		*s = p;
1182 		/* Skip blob object header first time around. */
1183 		memcpy(*s + offset,
1184 		    got_object_blob_get_read_buf(blob) + hdrlen, len - hdrlen);
1185 		hdrlen = 0;
1186 		offset = totlen;
1187 	} while (len > 0);
1188 
1189 	(*s)[totlen] = '\0';
1190 	return NULL;
1191 }
1192 
1193 const struct got_error *
1194 got_tree_entry_get_symlink_target(char **link_target, struct got_tree_entry *te,
1195     struct got_repository *repo)
1196 {
1197 	const struct got_error *err = NULL;
1198 	struct got_blob_object *blob = NULL;
1199 
1200 	*link_target = NULL;
1201 
1202 	if (!got_object_tree_entry_is_symlink(te))
1203 		return got_error(GOT_ERR_TREE_ENTRY_TYPE);
1204 
1205 	err = got_object_open_as_blob(&blob, repo,
1206 	    got_tree_entry_get_id(te), PATH_MAX);
1207 	if (err)
1208 		return err;
1209 
1210 	err = got_object_blob_read_to_str(link_target, blob);
1211 	got_object_blob_close(blob);
1212 	if (err) {
1213 		free(*link_target);
1214 		*link_target = NULL;
1215 	}
1216 	return err;
1217 }
1218 
1219 int
1220 got_tree_entry_get_index(struct got_tree_entry *te)
1221 {
1222 	return te->idx;
1223 }
1224 
1225 struct got_tree_entry *
1226 got_tree_entry_get_next(struct got_tree_object *tree,
1227     struct got_tree_entry *te)
1228 {
1229 	return got_object_tree_get_entry(tree, te->idx + 1);
1230 }
1231 
1232 struct got_tree_entry *
1233 got_tree_entry_get_prev(struct got_tree_object *tree,
1234     struct got_tree_entry *te)
1235 {
1236 	return got_object_tree_get_entry(tree, te->idx - 1);
1237 }
1238 
1239 static const struct got_error *
1240 request_packed_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
1241     struct got_pack *pack, struct got_packidx *packidx, int idx,
1242     struct got_object_id *id)
1243 {
1244 	const struct got_error *err = NULL;
1245 	int outfd_child;
1246 	int basefd, accumfd; /* temporary files for delta application */
1247 
1248 	basefd = got_opentempfd();
1249 	if (basefd == -1)
1250 		return got_error_from_errno("got_opentempfd");
1251 	accumfd = got_opentempfd();
1252 	if (accumfd == -1)
1253 		return got_error_from_errno("got_opentempfd");
1254 
1255 	outfd_child = dup(outfd);
1256 	if (outfd_child == -1)
1257 		return got_error_from_errno("dup");
1258 
1259 	err = got_privsep_send_blob_req(pack->privsep_child->ibuf, -1, id, idx);
1260 	if (err)
1261 		return err;
1262 
1263 	err = got_privsep_send_blob_outfd(pack->privsep_child->ibuf,
1264 	    outfd_child);
1265 	if (err) {
1266 		close(basefd);
1267 		close(accumfd);
1268 		return err;
1269 	}
1270 
1271 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
1272 	    basefd);
1273 	if (err) {
1274 		close(accumfd);
1275 		return err;
1276 	}
1277 
1278 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
1279 	    accumfd);
1280 	if (err)
1281 		return err;
1282 
1283 	err = got_privsep_recv_blob(outbuf, size, hdrlen,
1284 	    pack->privsep_child->ibuf);
1285 	if (err)
1286 		return err;
1287 
1288 	if (lseek(outfd, SEEK_SET, 0) == -1)
1289 		err = got_error_from_errno("lseek");
1290 
1291 	return err;
1292 }
1293 
1294 static const struct got_error *
1295 read_packed_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1296     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
1297     struct got_object_id *id)
1298 {
1299 	const struct got_error *err = NULL;
1300 
1301 	if (pack->privsep_child == NULL) {
1302 		err = start_pack_privsep_child(pack, packidx);
1303 		if (err)
1304 			return err;
1305 	}
1306 
1307 	return request_packed_blob(outbuf, size, hdrlen, outfd, pack, packidx,
1308 	    idx, id);
1309 }
1310 
1311 static const struct got_error *
1312 request_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
1313     int infd, struct imsgbuf *ibuf)
1314 {
1315 	const struct got_error *err = NULL;
1316 	int outfd_child;
1317 
1318 	outfd_child = dup(outfd);
1319 	if (outfd_child == -1)
1320 		return got_error_from_errno("dup");
1321 
1322 	err = got_privsep_send_blob_req(ibuf, infd, NULL, -1);
1323 	if (err)
1324 		return err;
1325 
1326 	err = got_privsep_send_blob_outfd(ibuf, outfd_child);
1327 	if (err)
1328 		return err;
1329 
1330 	err = got_privsep_recv_blob(outbuf, size, hdrlen, ibuf);
1331 	if (err)
1332 		return err;
1333 
1334 	if (lseek(outfd, SEEK_SET, 0) == -1)
1335 		return got_error_from_errno("lseek");
1336 
1337 	return err;
1338 }
1339 
1340 static const struct got_error *
1341 read_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1342     int outfd, int infd, struct got_repository *repo)
1343 {
1344 	const struct got_error *err;
1345 	int imsg_fds[2];
1346 	pid_t pid;
1347 	struct imsgbuf *ibuf;
1348 
1349 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd != -1) {
1350 		ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf;
1351 		return request_blob(outbuf, size, hdrlen, outfd, infd, ibuf);
1352 	}
1353 
1354 	ibuf = calloc(1, sizeof(*ibuf));
1355 	if (ibuf == NULL)
1356 		return got_error_from_errno("calloc");
1357 
1358 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1359 		err = got_error_from_errno("socketpair");
1360 		free(ibuf);
1361 		return err;
1362 	}
1363 
1364 	pid = fork();
1365 	if (pid == -1) {
1366 		err = got_error_from_errno("fork");
1367 		free(ibuf);
1368 		return err;
1369 	}
1370 	else if (pid == 0) {
1371 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_BLOB,
1372 		    repo->path);
1373 		/* not reached */
1374 	}
1375 
1376 	if (close(imsg_fds[1]) == -1) {
1377 		err = got_error_from_errno("close");
1378 		free(ibuf);
1379 		return err;
1380 	}
1381 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd =
1382 	    imsg_fds[0];
1383 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].pid = pid;
1384 	imsg_init(ibuf, imsg_fds[0]);
1385 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf = ibuf;
1386 
1387 	return request_blob(outbuf, size, hdrlen, outfd, infd, ibuf);
1388 }
1389 
1390 static const struct got_error *
1391 open_blob(struct got_blob_object **blob, struct got_repository *repo,
1392     struct got_object_id *id, size_t blocksize)
1393 {
1394 	const struct got_error *err = NULL;
1395 	struct got_packidx *packidx = NULL;
1396 	int idx;
1397 	char *path_packfile = NULL;
1398 	uint8_t *outbuf;
1399 	int outfd;
1400 	size_t size, hdrlen;
1401 	struct stat sb;
1402 
1403 	*blob = calloc(1, sizeof(**blob));
1404 	if (*blob == NULL)
1405 		return got_error_from_errno("calloc");
1406 
1407 	outfd = got_opentempfd();
1408 	if (outfd == -1)
1409 		return got_error_from_errno("got_opentempfd");
1410 
1411 	(*blob)->read_buf = malloc(blocksize);
1412 	if ((*blob)->read_buf == NULL) {
1413 		err = got_error_from_errno("malloc");
1414 		goto done;
1415 	}
1416 
1417 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1418 	if (err == NULL) {
1419 		struct got_pack *pack = NULL;
1420 
1421 		err = get_packfile_path(&path_packfile, packidx);
1422 		if (err)
1423 			goto done;
1424 
1425 		pack = got_repo_get_cached_pack(repo, path_packfile);
1426 		if (pack == NULL) {
1427 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1428 			    packidx);
1429 			if (err)
1430 				goto done;
1431 		}
1432 		err = read_packed_blob_privsep(&outbuf, &size, &hdrlen, outfd,
1433 		    pack, packidx, idx, id);
1434 	} else if (err->code == GOT_ERR_NO_OBJ) {
1435 		int infd;
1436 
1437 		err = open_loose_object(&infd, id, repo);
1438 		if (err)
1439 			goto done;
1440 		err = read_blob_privsep(&outbuf, &size, &hdrlen, outfd, infd,
1441 		    repo);
1442 	}
1443 	if (err)
1444 		goto done;
1445 
1446 	if (hdrlen > size) {
1447 		err = got_error(GOT_ERR_BAD_OBJ_HDR);
1448 		goto done;
1449 	}
1450 
1451 	if (outbuf) {
1452 		if (close(outfd) == -1 && err == NULL)
1453 			err = got_error_from_errno("close");
1454 		outfd = -1;
1455 		(*blob)->f = fmemopen(outbuf, size, "rb");
1456 		if ((*blob)->f == NULL) {
1457 			err = got_error_from_errno("fmemopen");
1458 			free(outbuf);
1459 			goto done;
1460 		}
1461 		(*blob)->data = outbuf;
1462 	} else {
1463 		if (fstat(outfd, &sb) == -1) {
1464 			err = got_error_from_errno("fstat");
1465 			goto done;
1466 		}
1467 
1468 		if (sb.st_size != size) {
1469 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1470 			goto done;
1471 		}
1472 
1473 		(*blob)->f = fdopen(outfd, "rb");
1474 		if ((*blob)->f == NULL) {
1475 			err = got_error_from_errno("fdopen");
1476 			close(outfd);
1477 			outfd = -1;
1478 			goto done;
1479 		}
1480 	}
1481 
1482 	(*blob)->hdrlen = hdrlen;
1483 	(*blob)->blocksize = blocksize;
1484 	memcpy(&(*blob)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
1485 
1486 done:
1487 	free(path_packfile);
1488 	if (err) {
1489 		if (*blob) {
1490 			got_object_blob_close(*blob);
1491 			*blob = NULL;
1492 		} else if (outfd != -1)
1493 			close(outfd);
1494 	}
1495 	return err;
1496 }
1497 
1498 const struct got_error *
1499 got_object_open_as_blob(struct got_blob_object **blob,
1500     struct got_repository *repo, struct got_object_id *id,
1501     size_t blocksize)
1502 {
1503 	return open_blob(blob, repo, id, blocksize);
1504 }
1505 
1506 const struct got_error *
1507 got_object_blob_open(struct got_blob_object **blob,
1508     struct got_repository *repo, struct got_object *obj, size_t blocksize)
1509 {
1510 	return open_blob(blob, repo, got_object_get_id(obj), blocksize);
1511 }
1512 
1513 const struct got_error *
1514 got_object_blob_close(struct got_blob_object *blob)
1515 {
1516 	const struct got_error *err = NULL;
1517 	free(blob->read_buf);
1518 	if (blob->f && fclose(blob->f) == EOF)
1519 		err = got_error_from_errno("fclose");
1520 	free(blob->data);
1521 	free(blob);
1522 	return err;
1523 }
1524 
1525 void
1526 got_object_blob_rewind(struct got_blob_object *blob)
1527 {
1528 	if (blob->f)
1529 		rewind(blob->f);
1530 }
1531 
1532 char *
1533 got_object_blob_id_str(struct got_blob_object *blob, char *buf, size_t size)
1534 {
1535 	return got_sha1_digest_to_str(blob->id.sha1, buf, size);
1536 }
1537 
1538 size_t
1539 got_object_blob_get_hdrlen(struct got_blob_object *blob)
1540 {
1541 	return blob->hdrlen;
1542 }
1543 
1544 const uint8_t *
1545 got_object_blob_get_read_buf(struct got_blob_object *blob)
1546 {
1547 	return blob->read_buf;
1548 }
1549 
1550 const struct got_error *
1551 got_object_blob_read_block(size_t *outlenp, struct got_blob_object *blob)
1552 {
1553 	size_t n;
1554 
1555 	n = fread(blob->read_buf, 1, blob->blocksize, blob->f);
1556 	if (n == 0 && ferror(blob->f))
1557 		return got_ferror(blob->f, GOT_ERR_IO);
1558 	*outlenp = n;
1559 	return NULL;
1560 }
1561 
1562 const struct got_error *
1563 got_object_blob_dump_to_file(off_t *filesize, int *nlines,
1564     off_t **line_offsets, FILE *outfile, struct got_blob_object *blob)
1565 {
1566 	const struct got_error *err = NULL;
1567 	size_t n, len, hdrlen;
1568 	const uint8_t *buf;
1569 	int i;
1570 	const int alloc_chunksz = 512;
1571 	size_t nalloc = 0;
1572 	off_t off = 0, total_len = 0;
1573 
1574 	if (line_offsets)
1575 		*line_offsets = NULL;
1576 	if (filesize)
1577 		*filesize = 0;
1578 	if (nlines)
1579 		*nlines = 0;
1580 
1581 	hdrlen = got_object_blob_get_hdrlen(blob);
1582 	do {
1583 		err = got_object_blob_read_block(&len, blob);
1584 		if (err)
1585 			return err;
1586 		if (len == 0)
1587 			break;
1588 		buf = got_object_blob_get_read_buf(blob);
1589 		i = hdrlen;
1590 		if (nlines) {
1591 			if (line_offsets && *line_offsets == NULL) {
1592 				/* Have some data but perhaps no '\n'. */
1593 				*nlines = 1;
1594 				nalloc = alloc_chunksz;
1595 				*line_offsets = calloc(nalloc,
1596 				    sizeof(**line_offsets));
1597 				if (*line_offsets == NULL)
1598 					return got_error_from_errno("calloc");
1599 
1600 				/* Skip forward over end of first line. */
1601 				while (i < len) {
1602 					if (buf[i] == '\n')
1603 						break;
1604 					i++;
1605 				}
1606 			}
1607 			/* Scan '\n' offsets in remaining chunk of data. */
1608 			while (i < len) {
1609 				if (buf[i] != '\n') {
1610 					i++;
1611 					continue;
1612 				}
1613 				(*nlines)++;
1614 				if (line_offsets && nalloc < *nlines) {
1615 					size_t n = *nlines + alloc_chunksz;
1616 					off_t *o = recallocarray(*line_offsets,
1617 					    nalloc, n, sizeof(**line_offsets));
1618 					if (o == NULL) {
1619 						free(*line_offsets);
1620 						*line_offsets = NULL;
1621 						return got_error_from_errno(
1622 						    "recallocarray");
1623 					}
1624 					*line_offsets = o;
1625 					nalloc = n;
1626 				}
1627 				if (line_offsets) {
1628 					off = total_len + i - hdrlen + 1;
1629 					(*line_offsets)[*nlines - 1] = off;
1630 				}
1631 				i++;
1632 			}
1633 		}
1634 		/* Skip blob object header first time around. */
1635 		n = fwrite(buf + hdrlen, 1, len - hdrlen, outfile);
1636 		if (n != len - hdrlen)
1637 			return got_ferror(outfile, GOT_ERR_IO);
1638 		total_len += len - hdrlen;
1639 		hdrlen = 0;
1640 	} while (len != 0);
1641 
1642 	if (fflush(outfile) != 0)
1643 		return got_error_from_errno("fflush");
1644 	rewind(outfile);
1645 
1646 	if (filesize)
1647 		*filesize = total_len;
1648 
1649 	return NULL;
1650 }
1651 
1652 static const struct got_error *
1653 request_packed_tag(struct got_tag_object **tag, struct got_pack *pack,
1654     int pack_idx, struct got_object_id *id)
1655 {
1656 	const struct got_error *err = NULL;
1657 
1658 	err = got_privsep_send_tag_req(pack->privsep_child->ibuf, -1, id,
1659 	    pack_idx);
1660 	if (err)
1661 		return err;
1662 
1663 	return got_privsep_recv_tag(tag, pack->privsep_child->ibuf);
1664 }
1665 
1666 static const struct got_error *
1667 read_packed_tag_privsep(struct got_tag_object **tag,
1668     struct got_pack *pack, struct got_packidx *packidx, int idx,
1669     struct got_object_id *id)
1670 {
1671 	const struct got_error *err = NULL;
1672 
1673 	if (pack->privsep_child)
1674 		return request_packed_tag(tag, pack, idx, id);
1675 
1676 	err = start_pack_privsep_child(pack, packidx);
1677 	if (err)
1678 		return err;
1679 
1680 	return request_packed_tag(tag, pack, idx, id);
1681 }
1682 
1683 static const struct got_error *
1684 request_tag(struct got_tag_object **tag, struct got_repository *repo,
1685     int fd)
1686 {
1687 	const struct got_error *err = NULL;
1688 	struct imsgbuf *ibuf;
1689 
1690 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf;
1691 
1692 	err = got_privsep_send_tag_req(ibuf, fd, NULL, -1);
1693 	if (err)
1694 		return err;
1695 
1696 	return got_privsep_recv_tag(tag, ibuf);
1697 }
1698 
1699 static const struct got_error *
1700 read_tag_privsep(struct got_tag_object **tag, int obj_fd,
1701     struct got_repository *repo)
1702 {
1703 	const struct got_error *err;
1704 	int imsg_fds[2];
1705 	pid_t pid;
1706 	struct imsgbuf *ibuf;
1707 
1708 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd != -1)
1709 		return request_tag(tag, repo, obj_fd);
1710 
1711 	ibuf = calloc(1, sizeof(*ibuf));
1712 	if (ibuf == NULL)
1713 		return got_error_from_errno("calloc");
1714 
1715 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1716 		err = got_error_from_errno("socketpair");
1717 		free(ibuf);
1718 		return err;
1719 	}
1720 
1721 	pid = fork();
1722 	if (pid == -1) {
1723 		err = got_error_from_errno("fork");
1724 		free(ibuf);
1725 		return err;
1726 	}
1727 	else if (pid == 0) {
1728 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TAG,
1729 		    repo->path);
1730 		/* not reached */
1731 	}
1732 
1733 	if (close(imsg_fds[1]) == -1) {
1734 		err = got_error_from_errno("close");
1735 		free(ibuf);
1736 		return err;
1737 	}
1738 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd =
1739 	    imsg_fds[0];
1740 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].pid = pid;
1741 	imsg_init(ibuf, imsg_fds[0]);
1742 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf = ibuf;
1743 
1744 	return request_tag(tag, repo, obj_fd);
1745 }
1746 
1747 static const struct got_error *
1748 open_tag(struct got_tag_object **tag, struct got_repository *repo,
1749     struct got_object_id *id, int check_cache)
1750 {
1751 	const struct got_error *err = NULL;
1752 	struct got_packidx *packidx = NULL;
1753 	int idx;
1754 	char *path_packfile = NULL;
1755 	struct got_object *obj = NULL;
1756 	int obj_type = GOT_OBJ_TYPE_ANY;
1757 
1758 	if (check_cache) {
1759 		*tag = got_repo_get_cached_tag(repo, id);
1760 		if (*tag != NULL) {
1761 			(*tag)->refcnt++;
1762 			return NULL;
1763 		}
1764 	} else
1765 		*tag = NULL;
1766 
1767 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1768 	if (err == NULL) {
1769 		struct got_pack *pack = NULL;
1770 
1771 		err = get_packfile_path(&path_packfile, packidx);
1772 		if (err)
1773 			return err;
1774 
1775 		pack = got_repo_get_cached_pack(repo, path_packfile);
1776 		if (pack == NULL) {
1777 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1778 			    packidx);
1779 			if (err)
1780 				goto done;
1781 		}
1782 
1783 		/* Beware of "lightweight" tags: Check object type first. */
1784 		err = read_packed_object_privsep(&obj, repo, pack, packidx,
1785 		    idx, id);
1786 		if (err)
1787 			goto done;
1788 		obj_type = obj->type;
1789 		got_object_close(obj);
1790 		if (obj_type != GOT_OBJ_TYPE_TAG) {
1791 			err = got_error(GOT_ERR_OBJ_TYPE);
1792 			goto done;
1793 		}
1794 		err = read_packed_tag_privsep(tag, pack, packidx, idx, id);
1795 	} else if (err->code == GOT_ERR_NO_OBJ) {
1796 		int fd;
1797 
1798 		err = open_loose_object(&fd, id, repo);
1799 		if (err)
1800 			return err;
1801 		err = read_object_header_privsep(&obj, repo, fd);
1802 		if (err)
1803 			return err;
1804 		obj_type = obj->type;
1805 		got_object_close(obj);
1806 		if (obj_type != GOT_OBJ_TYPE_TAG)
1807 			return got_error(GOT_ERR_OBJ_TYPE);
1808 
1809 		err = open_loose_object(&fd, id, repo);
1810 		if (err)
1811 			return err;
1812 		err = read_tag_privsep(tag, fd, repo);
1813 	}
1814 
1815 	if (err == NULL) {
1816 		(*tag)->refcnt++;
1817 		err = got_repo_cache_tag(repo, id, *tag);
1818 	}
1819 done:
1820 	free(path_packfile);
1821 	return err;
1822 }
1823 
1824 const struct got_error *
1825 got_object_open_as_tag(struct got_tag_object **tag,
1826     struct got_repository *repo, struct got_object_id *id)
1827 {
1828 	*tag = got_repo_get_cached_tag(repo, id);
1829 	if (*tag != NULL) {
1830 		(*tag)->refcnt++;
1831 		return NULL;
1832 	}
1833 
1834 	return open_tag(tag, repo, id, 0);
1835 }
1836 
1837 const struct got_error *
1838 got_object_tag_open(struct got_tag_object **tag,
1839     struct got_repository *repo, struct got_object *obj)
1840 {
1841 	return open_tag(tag, repo, got_object_get_id(obj), 1);
1842 }
1843 
1844 const char *
1845 got_object_tag_get_name(struct got_tag_object *tag)
1846 {
1847 	return tag->tag;
1848 }
1849 
1850 int
1851 got_object_tag_get_object_type(struct got_tag_object *tag)
1852 {
1853 	return tag->obj_type;
1854 }
1855 
1856 struct got_object_id *
1857 got_object_tag_get_object_id(struct got_tag_object *tag)
1858 {
1859 	return &tag->id;
1860 }
1861 
1862 time_t
1863 got_object_tag_get_tagger_time(struct got_tag_object *tag)
1864 {
1865 	return tag->tagger_time;
1866 }
1867 
1868 time_t
1869 got_object_tag_get_tagger_gmtoff(struct got_tag_object *tag)
1870 {
1871 	return tag->tagger_gmtoff;
1872 }
1873 
1874 const char *
1875 got_object_tag_get_tagger(struct got_tag_object *tag)
1876 {
1877 	return tag->tagger;
1878 }
1879 
1880 const char *
1881 got_object_tag_get_message(struct got_tag_object *tag)
1882 {
1883 	return tag->tagmsg;
1884 }
1885 
1886 static struct got_tree_entry *
1887 find_entry_by_name(struct got_tree_object *tree, const char *name, size_t len)
1888 {
1889 	int i;
1890 
1891 	/* Note that tree entries are sorted in strncmp() order. */
1892 	for (i = 0; i < tree->nentries; i++) {
1893 		struct got_tree_entry *te = &tree->entries[i];
1894 		int cmp = strncmp(te->name, name, len);
1895 		if (cmp < 0)
1896 			continue;
1897 		if (cmp > 0)
1898 			break;
1899 		if (te->name[len] == '\0')
1900 			return te;
1901 	}
1902 	return NULL;
1903 }
1904 
1905 struct got_tree_entry *
1906 got_object_tree_find_entry(struct got_tree_object *tree, const char *name)
1907 {
1908 	return find_entry_by_name(tree, name, strlen(name));
1909 }
1910 
1911 const struct got_error *
1912 got_object_id_by_path(struct got_object_id **id, struct got_repository *repo,
1913     struct got_object_id *commit_id, const char *path)
1914 {
1915 	const struct got_error *err = NULL;
1916 	struct got_commit_object *commit = NULL;
1917 	struct got_tree_object *tree = NULL;
1918 	struct got_tree_entry *te = NULL;
1919 	const char *seg, *s;
1920 	size_t seglen;
1921 
1922 	*id = NULL;
1923 
1924 	err = got_object_open_as_commit(&commit, repo, commit_id);
1925 	if (err)
1926 		goto done;
1927 
1928 	/* Handle opening of root of commit's tree. */
1929 	if (got_path_is_root_dir(path)) {
1930 		*id = got_object_id_dup(commit->tree_id);
1931 		if (*id == NULL)
1932 			err = got_error_from_errno("got_object_id_dup");
1933 		goto done;
1934 	}
1935 
1936 	err = got_object_open_as_tree(&tree, repo, commit->tree_id);
1937 	if (err)
1938 		goto done;
1939 
1940 	s = path;
1941 	while (s[0] == '/')
1942 		s++;
1943 	seg = s;
1944 	seglen = 0;
1945 	while (*s) {
1946 		struct got_tree_object *next_tree;
1947 
1948 		if (*s != '/') {
1949 			s++;
1950 			seglen++;
1951 			if (*s)
1952 				continue;
1953 		}
1954 
1955 		te = find_entry_by_name(tree, seg, seglen);
1956 		if (te == NULL) {
1957 			err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
1958 			goto done;
1959 		}
1960 
1961 		if (*s == '\0')
1962 			break;
1963 
1964 		seg = s + 1;
1965 		seglen = 0;
1966 		s++;
1967 		if (*s) {
1968 			err = got_object_open_as_tree(&next_tree, repo,
1969 			    &te->id);
1970 			te = NULL;
1971 			if (err)
1972 				goto done;
1973 			got_object_tree_close(tree);
1974 			tree = next_tree;
1975 		}
1976 	}
1977 
1978 	if (te) {
1979 		*id = got_object_id_dup(&te->id);
1980 		if (*id == NULL)
1981 			return got_error_from_errno("got_object_id_dup");
1982 	} else
1983 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
1984 done:
1985 	if (commit)
1986 		got_object_commit_close(commit);
1987 	if (tree)
1988 		got_object_tree_close(tree);
1989 	return err;
1990 }
1991 
1992 /*
1993  * Normalize file mode bits to avoid false positive tree entry differences
1994  * in case tree entries have unexpected mode bits set.
1995  */
1996 static mode_t
1997 normalize_mode_for_comparison(mode_t mode)
1998 {
1999 	/*
2000 	 * For directories, the only relevant bit is the IFDIR bit.
2001 	 * This allows us to detect paths changing from a directory
2002 	 * to a file and vice versa.
2003 	 */
2004 	if (S_ISDIR(mode))
2005 		return mode & S_IFDIR;
2006 
2007 	/*
2008 	 * For symlinks, the only relevant bit is the IFLNK bit.
2009 	 * This allows us to detect paths changing from a symlinks
2010 	 * to a file or directory and vice versa.
2011 	 */
2012 	if (S_ISLNK(mode))
2013 		return mode & S_IFLNK;
2014 
2015 	/* For files, the only change we care about is the executable bit. */
2016 	return mode & S_IXUSR;
2017 }
2018 
2019 const struct got_error *
2020 got_object_tree_path_changed(int *changed,
2021     struct got_tree_object *tree01, struct got_tree_object *tree02,
2022     const char *path, struct got_repository *repo)
2023 {
2024 	const struct got_error *err = NULL;
2025 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
2026 	struct got_tree_entry *te1 = NULL, *te2 = NULL;
2027 	const char *seg, *s;
2028 	size_t seglen;
2029 
2030 	*changed = 0;
2031 
2032 	/* We not do support comparing the root path. */
2033 	if (got_path_is_root_dir(path))
2034 		return got_error_path(path, GOT_ERR_BAD_PATH);
2035 
2036 	tree1 = tree01;
2037 	tree2 = tree02;
2038 	s = path;
2039 	while (*s == '/')
2040 		s++;
2041 	seg = s;
2042 	seglen = 0;
2043 	while (*s) {
2044 		struct got_tree_object *next_tree1, *next_tree2;
2045 		mode_t mode1, mode2;
2046 
2047 		if (*s != '/') {
2048 			s++;
2049 			seglen++;
2050 			if (*s)
2051 				continue;
2052 		}
2053 
2054 		te1 = find_entry_by_name(tree1, seg, seglen);
2055 		if (te1 == NULL) {
2056 			err = got_error(GOT_ERR_NO_OBJ);
2057 			goto done;
2058 		}
2059 
2060 		if (tree2)
2061 			te2 = find_entry_by_name(tree2, seg, seglen);
2062 
2063 		if (te2) {
2064 			mode1 = normalize_mode_for_comparison(te1->mode);
2065 			mode2 = normalize_mode_for_comparison(te2->mode);
2066 			if (mode1 != mode2) {
2067 				*changed = 1;
2068 				goto done;
2069 			}
2070 
2071 			if (got_object_id_cmp(&te1->id, &te2->id) == 0) {
2072 				*changed = 0;
2073 				goto done;
2074 			}
2075 		}
2076 
2077 		if (*s == '\0') { /* final path element */
2078 			*changed = 1;
2079 			goto done;
2080 		}
2081 
2082 		seg = s + 1;
2083 		s++;
2084 		seglen = 0;
2085 		if (*s) {
2086 			err = got_object_open_as_tree(&next_tree1, repo,
2087 			    &te1->id);
2088 			te1 = NULL;
2089 			if (err)
2090 				goto done;
2091 			if (tree1 != tree01)
2092 				got_object_tree_close(tree1);
2093 			tree1 = next_tree1;
2094 
2095 			if (te2) {
2096 				err = got_object_open_as_tree(&next_tree2, repo,
2097 				    &te2->id);
2098 				te2 = NULL;
2099 				if (err)
2100 					goto done;
2101 				if (tree2 != tree02)
2102 					got_object_tree_close(tree2);
2103 				tree2 = next_tree2;
2104 			} else if (tree2) {
2105 				if (tree2 != tree02)
2106 					got_object_tree_close(tree2);
2107 				tree2 = NULL;
2108 			}
2109 		}
2110 	}
2111 done:
2112 	if (tree1 && tree1 != tree01)
2113 		got_object_tree_close(tree1);
2114 	if (tree2 && tree2 != tree02)
2115 		got_object_tree_close(tree2);
2116 	return err;
2117 }
2118 
2119 const struct got_error *
2120 got_object_tree_entry_dup(struct got_tree_entry **new_te,
2121     struct got_tree_entry *te)
2122 {
2123 	const struct got_error *err = NULL;
2124 
2125 	*new_te = calloc(1, sizeof(**new_te));
2126 	if (*new_te == NULL)
2127 		return got_error_from_errno("calloc");
2128 
2129 	(*new_te)->mode = te->mode;
2130 	memcpy((*new_te)->name, te->name, sizeof((*new_te)->name));
2131 	memcpy(&(*new_te)->id, &te->id, sizeof((*new_te)->id));
2132 	return err;
2133 }
2134 
2135 int
2136 got_object_tree_entry_is_submodule(struct got_tree_entry *te)
2137 {
2138 	return (te->mode & S_IFMT) == (S_IFDIR | S_IFLNK);
2139 }
2140 
2141 int
2142 got_object_tree_entry_is_symlink(struct got_tree_entry *te)
2143 {
2144 	/* S_IFDIR check avoids confusing symlinks with submodules. */
2145 	return ((te->mode & (S_IFDIR | S_IFLNK)) == S_IFLNK);
2146 }
2147 
2148 static const struct got_error *
2149 resolve_symlink(char **link_target, const char *path,
2150     struct got_object_id *commit_id, struct got_repository *repo)
2151 {
2152 	const struct got_error *err = NULL;
2153 	char buf[PATH_MAX];
2154 	char *name, *parent_path = NULL;
2155 	struct got_object_id *tree_obj_id = NULL;
2156 	struct got_tree_object *tree = NULL;
2157 	struct got_tree_entry *te = NULL;
2158 
2159 	*link_target = NULL;
2160 
2161 	if (strlcpy(buf, path, sizeof(buf)) >= sizeof(buf))
2162 		return got_error(GOT_ERR_NO_SPACE);
2163 
2164 	name = basename(buf);
2165 	if (name == NULL)
2166 		return got_error_from_errno2("basename", path);
2167 
2168 	err = got_path_dirname(&parent_path, path);
2169 	if (err)
2170 		return err;
2171 
2172 	err = got_object_id_by_path(&tree_obj_id, repo, commit_id,
2173 	    parent_path);
2174 	if (err) {
2175 		if (err->code == GOT_ERR_NO_TREE_ENTRY) {
2176 			/* Display the complete path in error message. */
2177 			err = got_error_path(path, err->code);
2178 		}
2179 		goto done;
2180 	}
2181 
2182 	err = got_object_open_as_tree(&tree, repo, tree_obj_id);
2183 	if (err)
2184 		goto done;
2185 
2186 	te = got_object_tree_find_entry(tree, name);
2187 	if (te == NULL) {
2188 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
2189 		goto done;
2190 	}
2191 
2192 	if (got_object_tree_entry_is_symlink(te)) {
2193 		err = got_tree_entry_get_symlink_target(link_target, te, repo);
2194 		if (err)
2195 			goto done;
2196 		if (!got_path_is_absolute(*link_target)) {
2197 			char *abspath;
2198 			if (asprintf(&abspath, "%s/%s", parent_path,
2199 			    *link_target) == -1) {
2200 				err = got_error_from_errno("asprintf");
2201 				goto done;
2202 			}
2203 			free(*link_target);
2204 			*link_target = malloc(PATH_MAX);
2205 			if (*link_target == NULL) {
2206 				err = got_error_from_errno("malloc");
2207 				goto done;
2208 			}
2209 			err = got_canonpath(abspath, *link_target, PATH_MAX);
2210 			free(abspath);
2211 			if (err)
2212 				goto done;
2213 		}
2214 	}
2215 done:
2216 	free(tree_obj_id);
2217 	if (tree)
2218 		got_object_tree_close(tree);
2219 	if (err) {
2220 		free(*link_target);
2221 		*link_target = NULL;
2222 	}
2223 	return err;
2224 }
2225 
2226 const struct got_error *
2227 got_object_resolve_symlinks(char **link_target, const char *path,
2228     struct got_object_id *commit_id, struct got_repository *repo)
2229 {
2230 	const struct got_error *err = NULL;
2231 	char *next_target = NULL;
2232 	int max_recursion = 40; /* matches Git */
2233 
2234 	*link_target = NULL;
2235 
2236 	do {
2237 		err = resolve_symlink(&next_target,
2238 		    *link_target ? *link_target : path, commit_id, repo);
2239 		if (err)
2240 			break;
2241 		if (next_target) {
2242 			free(*link_target);
2243 			if (--max_recursion == 0) {
2244 				err = got_error_path(path, GOT_ERR_RECURSION);
2245 				*link_target = NULL;
2246 				break;
2247 			}
2248 			*link_target = next_target;
2249 		}
2250 	} while (next_target);
2251 
2252 	return err;
2253 }
2254 
2255 const struct got_error *
2256 got_traverse_packed_commits(struct got_object_id_queue *traversed_commits,
2257     struct got_object_id *commit_id, const char *path,
2258     struct got_repository *repo)
2259 {
2260 	const struct got_error *err = NULL;
2261 	struct got_pack *pack = NULL;
2262 	struct got_packidx *packidx = NULL;
2263 	char *path_packfile = NULL;
2264 	struct got_commit_object *changed_commit = NULL;
2265 	struct got_object_id *changed_commit_id = NULL;
2266 	int idx;
2267 
2268 	err = got_repo_search_packidx(&packidx, &idx, repo, commit_id);
2269 	if (err) {
2270 		if (err->code != GOT_ERR_NO_OBJ)
2271 			return err;
2272 		return NULL;
2273 	}
2274 
2275 	err = get_packfile_path(&path_packfile, packidx);
2276 	if (err)
2277 		return err;
2278 
2279 	pack = got_repo_get_cached_pack(repo, path_packfile);
2280 	if (pack == NULL) {
2281 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
2282 		if (err)
2283 			goto done;
2284 	}
2285 
2286 	if (pack->privsep_child == NULL) {
2287 		err = start_pack_privsep_child(pack, packidx);
2288 		if (err)
2289 			goto done;
2290 	}
2291 
2292 	err = got_privsep_send_commit_traversal_request(
2293 	    pack->privsep_child->ibuf, commit_id, idx, path);
2294 	if (err)
2295 		goto done;
2296 
2297 	err = got_privsep_recv_traversed_commits(&changed_commit,
2298 	    &changed_commit_id, traversed_commits, pack->privsep_child->ibuf);
2299 	if (err)
2300 		goto done;
2301 
2302 	if (changed_commit) {
2303 		/*
2304 		 * Cache the commit in which the path was changed.
2305 		 * This commit might be opened again soon.
2306 		 */
2307 		changed_commit->refcnt++;
2308 		err = got_repo_cache_commit(repo, changed_commit_id,
2309 		    changed_commit);
2310 		got_object_commit_close(changed_commit);
2311 	}
2312 done:
2313 	free(path_packfile);
2314 	free(changed_commit_id);
2315 	return err;
2316 }