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