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