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Date:: Tue Jun 7 19:20:01 2022 UTC
Message:: revert object enumeration in got-read-pack for now; needs more work This implementation marked commits and trees as enumerated before all trees which they depend on were enumerated. This behaviour leads to incomplete pack files when a tree is only partially packed and got-read-pack hits a missing tree entry as a result. The algorithm must be reworked such that packed leave nodes are marked enumerated first, then bubble-up. Found by op@
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1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <sys/stat.h>
19 #include <sys/queue.h>
20 #include <sys/tree.h>
21 #include <sys/uio.h>
22 #include <sys/socket.h>
23 #include <sys/wait.h>
24 #include <sys/resource.h>
25 #include <sys/mman.h>
26 
27 #include <errno.h>
28 #include <fcntl.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <stdint.h>
33 #include <sha1.h>
34 #include <unistd.h>
35 #include <zlib.h>
36 #include <ctype.h>
37 #include <libgen.h>
38 #include <limits.h>
39 #include <imsg.h>
40 #include <time.h>
41 
42 #include "got_error.h"
43 #include "got_object.h"
44 #include "got_repository.h"
45 #include "got_opentemp.h"
46 #include "got_path.h"
47 
48 #include "got_lib_sha1.h"
49 #include "got_lib_delta.h"
50 #include "got_lib_inflate.h"
51 #include "got_lib_object.h"
52 #include "got_lib_privsep.h"
53 #include "got_lib_object_idcache.h"
54 #include "got_lib_object_cache.h"
55 #include "got_lib_object_parse.h"
56 #include "got_lib_pack.h"
57 #include "got_lib_repository.h"
58 
59 #ifndef MIN
60 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
61 #endif
62 
63 struct got_object_id *
64 got_object_get_id(struct got_object *obj)
65 {
66 	return &obj->id;
67 }
68 
69 const struct got_error *
70 got_object_get_id_str(char **outbuf, struct got_object *obj)
71 {
72 	return got_object_id_str(outbuf, &obj->id);
73 }
74 
75 const struct got_error *
76 got_object_get_type(int *type, struct got_repository *repo,
77     struct got_object_id *id)
78 {
79 	const struct got_error *err = NULL;
80 	struct got_object *obj;
81 
82 	err = got_object_open(&obj, repo, id);
83 	if (err)
84 		return err;
85 
86 	switch (obj->type) {
87 	case GOT_OBJ_TYPE_COMMIT:
88 	case GOT_OBJ_TYPE_TREE:
89 	case GOT_OBJ_TYPE_BLOB:
90 	case GOT_OBJ_TYPE_TAG:
91 		*type = obj->type;
92 		break;
93 	default:
94 		err = got_error(GOT_ERR_OBJ_TYPE);
95 		break;
96 	}
97 
98 	got_object_close(obj);
99 	return err;
100 }
101 
102 const struct got_error *
103 got_object_get_path(char **path, struct got_object_id *id,
104     struct got_repository *repo)
105 {
106 	const struct got_error *err = NULL;
107 	char *hex = NULL;
108 	char *path_objects;
109 
110 	*path = NULL;
111 
112 	path_objects = got_repo_get_path_objects(repo);
113 	if (path_objects == NULL)
114 		return got_error_from_errno("got_repo_get_path_objects");
115 
116 	err = got_object_id_str(&hex, id);
117 	if (err)
118 		goto done;
119 
120 	if (asprintf(path, "%s/%.2x/%s", path_objects,
121 	    id->sha1[0], hex + 2) == -1)
122 		err = got_error_from_errno("asprintf");
123 
124 done:
125 	free(hex);
126 	free(path_objects);
127 	return err;
128 }
129 
130 const struct got_error *
131 got_object_open_loose_fd(int *fd, struct got_object_id *id,
132     struct got_repository *repo)
133 {
134 	const struct got_error *err = NULL;
135 	char *path;
136 
137 	err = got_object_get_path(&path, id, repo);
138 	if (err)
139 		return err;
140 	*fd = open(path, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
141 	if (*fd == -1) {
142 		err = got_error_from_errno2("open", path);
143 		goto done;
144 	}
145 done:
146 	free(path);
147 	return err;
148 }
149 
150 static const struct got_error *
151 request_packed_object(struct got_object **obj, struct got_pack *pack, int idx,
152     struct got_object_id *id)
153 {
154 	const struct got_error *err = NULL;
155 	struct imsgbuf *ibuf = pack->privsep_child->ibuf;
156 
157 	err = got_privsep_send_packed_obj_req(ibuf, idx, id);
158 	if (err)
159 		return err;
160 
161 	err = got_privsep_recv_obj(obj, ibuf);
162 	if (err)
163 		return err;
164 
165 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
166 
167 	return NULL;
168 }
169 
170 /* Create temporary files used during delta application. */
171 static const struct got_error *
172 pack_child_send_tempfiles(struct imsgbuf *ibuf, struct got_pack *pack)
173 {
174 	const struct got_error *err;
175 	int basefd = -1, accumfd = -1;
176 
177 	/* 
178 	 * For performance reasons, the child will keep reusing the
179 	 * same temporary files during every object request.
180 	 * Opening and closing new files for every object request is
181 	 * too expensive during operations such as 'gotadmin pack'.
182 	 */
183 	if (pack->child_has_tempfiles)
184 		return NULL;
185 
186 	basefd = dup(pack->basefd);
187 	if (basefd == -1)
188 		return got_error_from_errno("dup");
189 
190 	accumfd = dup(pack->accumfd);
191 	if (accumfd == -1) {
192 		err = got_error_from_errno("dup");
193 		goto done;
194 	}
195 
196 	err = got_privsep_send_tmpfd(ibuf, basefd);
197 	if (err)
198 		goto done;
199 
200 	err = got_privsep_send_tmpfd(ibuf, accumfd);
201 done:
202 	if (err) {
203 		if (basefd != -1)
204 			close(basefd);
205 		if (accumfd != -1)
206 			close(accumfd);
207 	} else
208 		pack->child_has_tempfiles = 1;
209 	return NULL;
210 }
211 
212 static const struct got_error *
213 request_packed_object_raw(uint8_t **outbuf, off_t *size, size_t *hdrlen,
214     int outfd, struct got_pack *pack, int idx, struct got_object_id *id)
215 {
216 	const struct got_error *err = NULL;
217 	struct imsgbuf *ibuf = pack->privsep_child->ibuf;
218 	int outfd_child;
219 
220 	 err = pack_child_send_tempfiles(ibuf, pack);
221 	 if (err)
222 		return err;
223 
224 	outfd_child = dup(outfd);
225 	if (outfd_child == -1)
226 		return got_error_from_errno("dup");
227 
228 	err = got_privsep_send_packed_raw_obj_req(ibuf, idx, id);
229 	if (err) {
230 		close(outfd_child);
231 		return err;
232 	}
233 
234 	err = got_privsep_send_raw_obj_outfd(ibuf, outfd_child);
235 	if (err)
236 		return err;
237 
238 	err = got_privsep_recv_raw_obj(outbuf, size, hdrlen, ibuf);
239 	if (err)
240 		return err;
241 
242 	return NULL;
243 }
244 
245 static void
246 set_max_datasize(void)
247 {
248 	struct rlimit rl;
249 
250 	if (getrlimit(RLIMIT_DATA, &rl) != 0)
251 		return;
252 
253 	rl.rlim_cur = rl.rlim_max;
254 	setrlimit(RLIMIT_DATA, &rl);
255 }
256 
257 static const struct got_error *
258 start_pack_privsep_child(struct got_pack *pack, struct got_packidx *packidx)
259 {
260 	const struct got_error *err = NULL;
261 	int imsg_fds[2];
262 	pid_t pid;
263 	struct imsgbuf *ibuf;
264 
265 	ibuf = calloc(1, sizeof(*ibuf));
266 	if (ibuf == NULL)
267 		return got_error_from_errno("calloc");
268 
269 	pack->privsep_child = calloc(1, sizeof(*pack->privsep_child));
270 	if (pack->privsep_child == NULL) {
271 		err = got_error_from_errno("calloc");
272 		free(ibuf);
273 		return err;
274 	}
275 	pack->child_has_tempfiles = 0;
276 	pack->child_has_delta_outfd = 0;
277 
278 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
279 		err = got_error_from_errno("socketpair");
280 		goto done;
281 	}
282 
283 	pid = fork();
284 	if (pid == -1) {
285 		err = got_error_from_errno("fork");
286 		goto done;
287 	} else if (pid == 0) {
288 		set_max_datasize();
289 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PACK,
290 		    pack->path_packfile);
291 		/* not reached */
292 	}
293 
294 	if (close(imsg_fds[1]) == -1)
295 		return got_error_from_errno("close");
296 	pack->privsep_child->imsg_fd = imsg_fds[0];
297 	pack->privsep_child->pid = pid;
298 	imsg_init(ibuf, imsg_fds[0]);
299 	pack->privsep_child->ibuf = ibuf;
300 
301 	err = got_privsep_init_pack_child(ibuf, pack, packidx);
302 	if (err) {
303 		const struct got_error *child_err;
304 		err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
305 		child_err = got_privsep_wait_for_child(
306 		    pack->privsep_child->pid);
307 		if (child_err && err == NULL)
308 			err = child_err;
309 	}
310 done:
311 	if (err) {
312 		free(ibuf);
313 		free(pack->privsep_child);
314 		pack->privsep_child = NULL;
315 	}
316 	return err;
317 }
318 
319 static const struct got_error *
320 read_packed_object_privsep(struct got_object **obj,
321     struct got_repository *repo, struct got_pack *pack,
322     struct got_packidx *packidx, int idx, struct got_object_id *id)
323 {
324 	const struct got_error *err = NULL;
325 
326 	if (pack->privsep_child == NULL) {
327 		err = start_pack_privsep_child(pack, packidx);
328 		if (err)
329 			return err;
330 	}
331 
332 	return request_packed_object(obj, pack, idx, id);
333 }
334 
335 static const struct got_error *
336 read_packed_object_raw_privsep(uint8_t **outbuf, off_t *size, size_t *hdrlen,
337     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
338     struct got_object_id *id)
339 {
340 	const struct got_error *err = NULL;
341 
342 	if (pack->privsep_child == NULL) {
343 		err = start_pack_privsep_child(pack, packidx);
344 		if (err)
345 			return err;
346 	}
347 
348 	return request_packed_object_raw(outbuf, size, hdrlen, outfd, pack,
349 	    idx, id);
350 }
351 
352 const struct got_error *
353 got_object_open_packed(struct got_object **obj, struct got_object_id *id,
354     struct got_repository *repo)
355 {
356 	const struct got_error *err = NULL;
357 	struct got_pack *pack = NULL;
358 	struct got_packidx *packidx = NULL;
359 	int idx;
360 	char *path_packfile;
361 
362 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
363 	if (err)
364 		return err;
365 
366 	err = got_packidx_get_packfile_path(&path_packfile,
367 	    packidx->path_packidx);
368 	if (err)
369 		return err;
370 
371 	pack = got_repo_get_cached_pack(repo, path_packfile);
372 	if (pack == NULL) {
373 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
374 		if (err)
375 			goto done;
376 	}
377 
378 	err = read_packed_object_privsep(obj, repo, pack, packidx, idx, id);
379 	if (err)
380 		goto done;
381 done:
382 	free(path_packfile);
383 	return err;
384 }
385 
386 const struct got_error *
387 got_object_open_from_packfile(struct got_object **obj, struct got_object_id *id,
388     struct got_pack *pack, struct got_packidx *packidx, int obj_idx,
389     struct got_repository *repo)
390 {
391 	return read_packed_object_privsep(obj, repo, pack, packidx,
392 	    obj_idx, id);
393 }
394 
395 const struct got_error *
396 got_object_read_raw_delta(uint64_t *base_size, uint64_t *result_size,
397     off_t *delta_size, off_t *delta_compressed_size, off_t *delta_offset,
398     off_t *delta_out_offset, struct got_object_id **base_id, int delta_cache_fd,
399     struct got_packidx *packidx, int obj_idx, struct got_object_id *id,
400     struct got_repository *repo)
401 {
402 	const struct got_error *err = NULL;
403 	struct got_pack *pack = NULL;
404 	char *path_packfile;
405 
406 	*base_size = 0;
407 	*result_size = 0;
408 	*delta_size = 0;
409 	*delta_compressed_size = 0;
410 	*delta_offset = 0;
411 	*delta_out_offset = 0;
412 
413 	err = got_packidx_get_packfile_path(&path_packfile,
414 	    packidx->path_packidx);
415 	if (err)
416 		return err;
417 
418 	pack = got_repo_get_cached_pack(repo, path_packfile);
419 	if (pack == NULL) {
420 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
421 		if (err)
422 			return err;
423 	}
424 
425 	if (pack->privsep_child == NULL) {
426 		err = start_pack_privsep_child(pack, packidx);
427 		if (err)
428 			return err;
429 	}
430 
431 	if (!pack->child_has_delta_outfd) {
432 		int outfd_child;
433 		outfd_child = dup(delta_cache_fd);
434 		if (outfd_child == -1)
435 			return got_error_from_errno("dup");
436 		err = got_privsep_send_raw_delta_outfd(
437 		    pack->privsep_child->ibuf, outfd_child);
438 		if (err)
439 			return err;
440 		pack->child_has_delta_outfd = 1;
441 	}
442 
443 	err = got_privsep_send_raw_delta_req(pack->privsep_child->ibuf,
444 	    obj_idx, id);
445 	if (err)
446 		return err;
447 
448 	return got_privsep_recv_raw_delta(base_size, result_size, delta_size,
449 	    delta_compressed_size, delta_offset, delta_out_offset, base_id,
450 	    pack->privsep_child->ibuf);
451 }
452 
453 /*
454  * XXX This function does not really belong in object.c. It is only here
455  * because it needs start_pack_privsep_child(); relevant code should
456  * probably be moved to pack.c/pack_create.c.
457  */
458 const struct got_error *
459 got_object_prepare_delta_reuse(struct got_pack **pack,
460     struct got_packidx *packidx, int delta_outfd, struct got_repository *repo)
461 {
462 	const struct got_error *err = NULL;
463 	char *path_packfile = NULL;
464 
465 	err = got_packidx_get_packfile_path(&path_packfile,
466 	    packidx->path_packidx);
467 	if (err)
468 		return err;
469 
470 	*pack = got_repo_get_cached_pack(repo, path_packfile);
471 	if (*pack == NULL) {
472 		err = got_repo_cache_pack(pack, repo, path_packfile, packidx);
473 		if (err)
474 			goto done;
475 	}
476 	if ((*pack)->privsep_child == NULL) {
477 		err = start_pack_privsep_child(*pack, packidx);
478 		if (err)
479 			goto done;
480 	}
481 
482 	if (!(*pack)->child_has_delta_outfd) {
483 		int outfd_child;
484 		outfd_child = dup(delta_outfd);
485 		if (outfd_child == -1) {
486 			err = got_error_from_errno("dup");
487 			goto done;
488 		}
489 		err = got_privsep_send_raw_delta_outfd(
490 		    (*pack)->privsep_child->ibuf, outfd_child);
491 		if (err)
492 			goto done;
493 		(*pack)->child_has_delta_outfd = 1;
494 	}
495 
496 	err = got_privsep_send_delta_reuse_req((*pack)->privsep_child->ibuf);
497 done:
498 	free(path_packfile);
499 	return err;
500 }
501 
502 static const struct got_error *
503 request_object(struct got_object **obj, struct got_object_id *id,
504     struct got_repository *repo, int fd)
505 {
506 	const struct got_error *err = NULL;
507 	struct imsgbuf *ibuf;
508 
509 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf;
510 
511 	err = got_privsep_send_obj_req(ibuf, fd, id);
512 	if (err)
513 		return err;
514 
515 	return got_privsep_recv_obj(obj, ibuf);
516 }
517 
518 static const struct got_error *
519 request_raw_object(uint8_t **outbuf, off_t *size, size_t *hdrlen, int outfd,
520     struct got_object_id *id, struct got_repository *repo, int infd)
521 {
522 	const struct got_error *err = NULL;
523 	struct imsgbuf *ibuf;
524 	int outfd_child;
525 
526 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf;
527 
528 	outfd_child = dup(outfd);
529 	if (outfd_child == -1)
530 		return got_error_from_errno("dup");
531 
532 	err = got_privsep_send_raw_obj_req(ibuf, infd, id);
533 	if (err)
534 		return err;
535 
536 	err = got_privsep_send_raw_obj_outfd(ibuf, outfd_child);
537 	if (err)
538 		return err;
539 
540 	return got_privsep_recv_raw_obj(outbuf, size, hdrlen, ibuf);
541 }
542 
543 static const struct got_error *
544 start_read_object_child(struct got_repository *repo)
545 {
546 	const struct got_error *err = NULL;
547 	int imsg_fds[2];
548 	pid_t pid;
549 	struct imsgbuf *ibuf;
550 
551 	ibuf = calloc(1, sizeof(*ibuf));
552 	if (ibuf == NULL)
553 		return got_error_from_errno("calloc");
554 
555 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
556 		err = got_error_from_errno("socketpair");
557 		free(ibuf);
558 		return err;
559 	}
560 
561 	pid = fork();
562 	if (pid == -1) {
563 		err = got_error_from_errno("fork");
564 		free(ibuf);
565 		return err;
566 	}
567 	else if (pid == 0) {
568 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_OBJECT,
569 		    repo->path);
570 		/* not reached */
571 	}
572 
573 	if (close(imsg_fds[1]) == -1) {
574 		err = got_error_from_errno("close");
575 		free(ibuf);
576 		return err;
577 	}
578 
579 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd =
580 	    imsg_fds[0];
581 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].pid = pid;
582 	imsg_init(ibuf, imsg_fds[0]);
583 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf = ibuf;
584 
585 	return NULL;
586 }
587 
588 const struct got_error *
589 got_object_read_header_privsep(struct got_object **obj,
590     struct got_object_id *id, struct got_repository *repo, int obj_fd)
591 {
592 	const struct got_error *err;
593 
594 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd != -1)
595 		return request_object(obj, id, repo, obj_fd);
596 
597 	err = start_read_object_child(repo);
598 	if (err) {
599 		close(obj_fd);
600 		return err;
601 	}
602 
603 	return request_object(obj, id, repo, obj_fd);
604 }
605 
606 static const struct got_error *
607 read_object_raw_privsep(uint8_t **outbuf, off_t *size, size_t *hdrlen,
608     int outfd, struct got_object_id *id, struct got_repository *repo,
609     int obj_fd)
610 {
611 	const struct got_error *err;
612 
613 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd != -1)
614 		return request_raw_object(outbuf, size, hdrlen, outfd, id,
615 		    repo, obj_fd);
616 
617 	err = start_read_object_child(repo);
618 	if (err)
619 		return err;
620 
621 	return request_raw_object(outbuf, size, hdrlen, outfd, id, repo,
622 	    obj_fd);
623 }
624 
625 const struct got_error *
626 got_object_open(struct got_object **obj, struct got_repository *repo,
627     struct got_object_id *id)
628 {
629 	const struct got_error *err = NULL;
630 	int fd;
631 
632 	*obj = got_repo_get_cached_object(repo, id);
633 	if (*obj != NULL) {
634 		(*obj)->refcnt++;
635 		return NULL;
636 	}
637 
638 	err = got_object_open_packed(obj, id, repo);
639 	if (err && err->code != GOT_ERR_NO_OBJ)
640 		return err;
641 	if (*obj) {
642 		(*obj)->refcnt++;
643 		return got_repo_cache_object(repo, id, *obj);
644 	}
645 
646 	err = got_object_open_loose_fd(&fd, id, repo);
647 	if (err) {
648 		if (err->code == GOT_ERR_ERRNO && errno == ENOENT)
649 			err = got_error_no_obj(id);
650 		return err;
651 	}
652 
653 	err = got_object_read_header_privsep(obj, id, repo, fd);
654 	if (err)
655 		return err;
656 
657 	memcpy((*obj)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
658 
659 	(*obj)->refcnt++;
660 	return got_repo_cache_object(repo, id, *obj);
661 }
662 
663 /* *outfd must be initialized to -1 by caller */
664 const struct got_error *
665 got_object_raw_open(struct got_raw_object **obj, int *outfd,
666     struct got_repository *repo, struct got_object_id *id)
667 {
668 	const struct got_error *err = NULL;
669 	struct got_packidx *packidx = NULL;
670 	int idx;
671 	uint8_t *outbuf = NULL;
672 	off_t size = 0;
673 	size_t hdrlen = 0;
674 	char *path_packfile = NULL;
675 
676 	*obj = got_repo_get_cached_raw_object(repo, id);
677 	if (*obj != NULL) {
678 		(*obj)->refcnt++;
679 		return NULL;
680 	}
681 
682 	if (*outfd == -1) {
683 		*outfd = got_opentempfd();
684 		if (*outfd == -1)
685 			return got_error_from_errno("got_opentempfd");
686 	}
687 
688 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
689 	if (err == NULL) {
690 		struct got_pack *pack = NULL;
691 
692 		err = got_packidx_get_packfile_path(&path_packfile,
693 		    packidx->path_packidx);
694 		if (err)
695 			goto done;
696 
697 		pack = got_repo_get_cached_pack(repo, path_packfile);
698 		if (pack == NULL) {
699 			err = got_repo_cache_pack(&pack, repo, path_packfile,
700 			    packidx);
701 			if (err)
702 				goto done;
703 		}
704 		err = read_packed_object_raw_privsep(&outbuf, &size, &hdrlen,
705 		    *outfd, pack, packidx, idx, id);
706 		if (err)
707 			goto done;
708 	} else if (err->code == GOT_ERR_NO_OBJ) {
709 		int fd;
710 
711 		err = got_object_open_loose_fd(&fd, id, repo);
712 		if (err)
713 			goto done;
714 		err = read_object_raw_privsep(&outbuf, &size, &hdrlen, *outfd,
715 		    id, repo, fd);
716 		if (err)
717 			goto done;
718 	}
719 
720 	*obj = calloc(1, sizeof(**obj));
721 	if (*obj == NULL) {
722 		err = got_error_from_errno("calloc");
723 		goto done;
724 	}
725 	(*obj)->fd = -1;
726 
727 	if (outbuf) {
728 		(*obj)->data = outbuf;
729 	} else {
730 		struct stat sb;
731 		if (fstat(*outfd, &sb) == -1) {
732 			err = got_error_from_errno("fstat");
733 			goto done;
734 		}
735 
736 		if (sb.st_size != hdrlen + size) {
737 			err = got_error(GOT_ERR_PRIVSEP_LEN);
738 			goto done;
739 		}
740 #ifndef GOT_PACK_NO_MMAP
741 		if (hdrlen + size > 0) {
742 			(*obj)->data = mmap(NULL, hdrlen + size, PROT_READ,
743 			    MAP_PRIVATE, *outfd, 0);
744 			if ((*obj)->data == MAP_FAILED) {
745 				if (errno != ENOMEM) {
746 					err = got_error_from_errno("mmap");
747 					goto done;
748 				}
749 				(*obj)->data = NULL;
750 			} else {
751 				(*obj)->fd = *outfd;
752 				*outfd = -1;
753 			}
754 		}
755 #endif
756 		if (*outfd != -1) {
757 			(*obj)->f = fdopen(*outfd, "r");
758 			if ((*obj)->f == NULL) {
759 				err = got_error_from_errno("fdopen");
760 				goto done;
761 			}
762 			*outfd = -1;
763 		}
764 	}
765 	(*obj)->hdrlen = hdrlen;
766 	(*obj)->size = size;
767 	err = got_repo_cache_raw_object(repo, id, *obj);
768 done:
769 	free(path_packfile);
770 	if (err) {
771 		if (*obj) {
772 			got_object_raw_close(*obj);
773 			*obj = NULL;
774 		}
775 		free(outbuf);
776 	} else
777 		(*obj)->refcnt++;
778 	return err;
779 }
780 
781 const struct got_error *
782 got_object_open_by_id_str(struct got_object **obj, struct got_repository *repo,
783     const char *id_str)
784 {
785 	struct got_object_id id;
786 
787 	if (!got_parse_sha1_digest(id.sha1, id_str))
788 		return got_error_path(id_str, GOT_ERR_BAD_OBJ_ID_STR);
789 
790 	return got_object_open(obj, repo, &id);
791 }
792 
793 const struct got_error *
794 got_object_resolve_id_str(struct got_object_id **id,
795     struct got_repository *repo, const char *id_str)
796 {
797 	const struct got_error *err = NULL;
798 	struct got_object *obj;
799 
800 	err = got_object_open_by_id_str(&obj, repo, id_str);
801 	if (err)
802 		return err;
803 
804 	*id = got_object_id_dup(got_object_get_id(obj));
805 	got_object_close(obj);
806 	if (*id == NULL)
807 		return got_error_from_errno("got_object_id_dup");
808 
809 	return NULL;
810 }
811 
812 static const struct got_error *
813 request_packed_commit(struct got_commit_object **commit, struct got_pack *pack,
814     int pack_idx, struct got_object_id *id)
815 {
816 	const struct got_error *err = NULL;
817 
818 	err = got_privsep_send_commit_req(pack->privsep_child->ibuf, -1, id,
819 	    pack_idx);
820 	if (err)
821 		return err;
822 
823 	err = got_privsep_recv_commit(commit, pack->privsep_child->ibuf);
824 	if (err)
825 		return err;
826 
827 	(*commit)->flags |= GOT_COMMIT_FLAG_PACKED;
828 	return NULL;
829 }
830 
831 static const struct got_error *
832 read_packed_commit_privsep(struct got_commit_object **commit,
833     struct got_pack *pack, struct got_packidx *packidx, int idx,
834     struct got_object_id *id)
835 {
836 	const struct got_error *err = NULL;
837 
838 	if (pack->privsep_child)
839 		return request_packed_commit(commit, pack, idx, id);
840 
841 	err = start_pack_privsep_child(pack, packidx);
842 	if (err)
843 		return err;
844 
845 	return request_packed_commit(commit, pack, idx, id);
846 }
847 
848 static const struct got_error *
849 request_commit(struct got_commit_object **commit, struct got_repository *repo,
850     int fd, struct got_object_id *id)
851 {
852 	const struct got_error *err = NULL;
853 	struct imsgbuf *ibuf;
854 
855 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf;
856 
857 	err = got_privsep_send_commit_req(ibuf, fd, id, -1);
858 	if (err)
859 		return err;
860 
861 	return got_privsep_recv_commit(commit, ibuf);
862 }
863 
864 static const struct got_error *
865 read_commit_privsep(struct got_commit_object **commit, int obj_fd,
866     struct got_object_id *id, struct got_repository *repo)
867 {
868 	const struct got_error *err;
869 	int imsg_fds[2];
870 	pid_t pid;
871 	struct imsgbuf *ibuf;
872 
873 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd != -1)
874 		return request_commit(commit, repo, obj_fd, id);
875 
876 	ibuf = calloc(1, sizeof(*ibuf));
877 	if (ibuf == NULL)
878 		return got_error_from_errno("calloc");
879 
880 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
881 		err = got_error_from_errno("socketpair");
882 		free(ibuf);
883 		return err;
884 	}
885 
886 	pid = fork();
887 	if (pid == -1) {
888 		err = got_error_from_errno("fork");
889 		free(ibuf);
890 		return err;
891 	}
892 	else if (pid == 0) {
893 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_COMMIT,
894 		    repo->path);
895 		/* not reached */
896 	}
897 
898 	if (close(imsg_fds[1]) == -1) {
899 		err = got_error_from_errno("close");
900 		free(ibuf);
901 		return err;
902 	}
903 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd =
904 	    imsg_fds[0];
905 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].pid = pid;
906 	imsg_init(ibuf, imsg_fds[0]);
907 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf = ibuf;
908 
909 	return request_commit(commit, repo, obj_fd, id);
910 }
911 
912 
913 static const struct got_error *
914 open_commit(struct got_commit_object **commit,
915     struct got_repository *repo, struct got_object_id *id, int check_cache)
916 {
917 	const struct got_error *err = NULL;
918 	struct got_packidx *packidx = NULL;
919 	int idx;
920 	char *path_packfile = NULL;
921 
922 	if (check_cache) {
923 		*commit = got_repo_get_cached_commit(repo, id);
924 		if (*commit != NULL) {
925 			(*commit)->refcnt++;
926 			return NULL;
927 		}
928 	} else
929 		*commit = NULL;
930 
931 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
932 	if (err == NULL) {
933 		struct got_pack *pack = NULL;
934 
935 		err = got_packidx_get_packfile_path(&path_packfile,
936 		    packidx->path_packidx);
937 		if (err)
938 			return err;
939 
940 		pack = got_repo_get_cached_pack(repo, path_packfile);
941 		if (pack == NULL) {
942 			err = got_repo_cache_pack(&pack, repo, path_packfile,
943 			    packidx);
944 			if (err)
945 				goto done;
946 		}
947 		err = read_packed_commit_privsep(commit, pack,
948 		    packidx, idx, id);
949 	} else if (err->code == GOT_ERR_NO_OBJ) {
950 		int fd;
951 
952 		err = got_object_open_loose_fd(&fd, id, repo);
953 		if (err)
954 			return err;
955 		err = read_commit_privsep(commit, fd, id, repo);
956 	}
957 
958 	if (err == NULL) {
959 		(*commit)->refcnt++;
960 		err = got_repo_cache_commit(repo, id, *commit);
961 	}
962 done:
963 	free(path_packfile);
964 	return err;
965 }
966 
967 const struct got_error *
968 got_object_open_as_commit(struct got_commit_object **commit,
969     struct got_repository *repo, struct got_object_id *id)
970 {
971 	*commit = got_repo_get_cached_commit(repo, id);
972 	if (*commit != NULL) {
973 		(*commit)->refcnt++;
974 		return NULL;
975 	}
976 
977 	return open_commit(commit, repo, id, 0);
978 }
979 
980 const struct got_error *
981 got_object_commit_open(struct got_commit_object **commit,
982     struct got_repository *repo, struct got_object *obj)
983 {
984 	return open_commit(commit, repo, got_object_get_id(obj), 1);
985 }
986 
987 const struct got_error *
988 got_object_qid_alloc(struct got_object_qid **qid, struct got_object_id *id)
989 {
990 	*qid = calloc(1, sizeof(**qid));
991 	if (*qid == NULL)
992 		return got_error_from_errno("calloc");
993 
994 	memcpy(&(*qid)->id, id, sizeof((*qid)->id));
995 	return NULL;
996 }
997 
998 const struct got_error *
999 got_object_id_queue_copy(const struct got_object_id_queue *src,
1000     struct got_object_id_queue *dest)
1001 {
1002 	const struct got_error *err;
1003 	struct got_object_qid *qid;
1004 
1005 	STAILQ_FOREACH(qid, src, entry) {
1006 		struct got_object_qid *new;
1007 		/*
1008 		 * Deep-copy the object ID only. Let the caller deal
1009 		 * with setting up the new->data pointer if needed.
1010 		 */
1011 		err = got_object_qid_alloc(&new, &qid->id); 
1012 		if (err) {
1013 			got_object_id_queue_free(dest);
1014 			return err;
1015 		}
1016 		STAILQ_INSERT_TAIL(dest, new, entry);
1017 	}
1018 
1019 	return NULL;
1020 }
1021 
1022 static const struct got_error *
1023 request_packed_tree(struct got_tree_object **tree, struct got_pack *pack,
1024     int pack_idx, struct got_object_id *id)
1025 {
1026 	const struct got_error *err = NULL;
1027 
1028 	err = got_privsep_send_tree_req(pack->privsep_child->ibuf, -1, id,
1029 	    pack_idx);
1030 	if (err)
1031 		return err;
1032 
1033 	return got_privsep_recv_tree(tree, pack->privsep_child->ibuf);
1034 }
1035 
1036 static const struct got_error *
1037 read_packed_tree_privsep(struct got_tree_object **tree,
1038     struct got_pack *pack, struct got_packidx *packidx, int idx,
1039     struct got_object_id *id)
1040 {
1041 	const struct got_error *err = NULL;
1042 
1043 	if (pack->privsep_child)
1044 		return request_packed_tree(tree, pack, idx, id);
1045 
1046 	err = start_pack_privsep_child(pack, packidx);
1047 	if (err)
1048 		return err;
1049 
1050 	return request_packed_tree(tree, pack, idx, id);
1051 }
1052 
1053 static const struct got_error *
1054 request_tree(struct got_tree_object **tree, struct got_repository *repo,
1055     int fd, struct got_object_id *id)
1056 {
1057 	const struct got_error *err = NULL;
1058 	struct imsgbuf *ibuf;
1059 
1060 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf;
1061 
1062 	err = got_privsep_send_tree_req(ibuf, fd, id, -1);
1063 	if (err)
1064 		return err;
1065 
1066 	return got_privsep_recv_tree(tree, ibuf);
1067 }
1068 
1069 const struct got_error *
1070 read_tree_privsep(struct got_tree_object **tree, int obj_fd,
1071     struct got_object_id *id, struct got_repository *repo)
1072 {
1073 	const struct got_error *err;
1074 	int imsg_fds[2];
1075 	pid_t pid;
1076 	struct imsgbuf *ibuf;
1077 
1078 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd != -1)
1079 		return request_tree(tree, repo, obj_fd, id);
1080 
1081 	ibuf = calloc(1, sizeof(*ibuf));
1082 	if (ibuf == NULL)
1083 		return got_error_from_errno("calloc");
1084 
1085 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1086 		err = got_error_from_errno("socketpair");
1087 		free(ibuf);
1088 		return err;
1089 	}
1090 
1091 	pid = fork();
1092 	if (pid == -1) {
1093 		err = got_error_from_errno("fork");
1094 		free(ibuf);
1095 		return err;
1096 	}
1097 	else if (pid == 0) {
1098 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TREE,
1099 		    repo->path);
1100 		/* not reached */
1101 	}
1102 
1103 	if (close(imsg_fds[1]) == -1) {
1104 		err = got_error_from_errno("close");
1105 		free(ibuf);
1106 		return err;
1107 	}
1108 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd =
1109 	    imsg_fds[0];
1110 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].pid = pid;
1111 	imsg_init(ibuf, imsg_fds[0]);
1112 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf = ibuf;
1113 
1114 
1115 	return request_tree(tree, repo, obj_fd, id);
1116 }
1117 
1118 static const struct got_error *
1119 open_tree(struct got_tree_object **tree, struct got_repository *repo,
1120     struct got_object_id *id, int check_cache)
1121 {
1122 	const struct got_error *err = NULL;
1123 	struct got_packidx *packidx = NULL;
1124 	int idx;
1125 	char *path_packfile = NULL;
1126 
1127 	if (check_cache) {
1128 		*tree = got_repo_get_cached_tree(repo, id);
1129 		if (*tree != NULL) {
1130 			(*tree)->refcnt++;
1131 			return NULL;
1132 		}
1133 	} else
1134 		*tree = NULL;
1135 
1136 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1137 	if (err == NULL) {
1138 		struct got_pack *pack = NULL;
1139 
1140 		err = got_packidx_get_packfile_path(&path_packfile,
1141 		    packidx->path_packidx);
1142 		if (err)
1143 			return err;
1144 
1145 		pack = got_repo_get_cached_pack(repo, path_packfile);
1146 		if (pack == NULL) {
1147 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1148 			    packidx);
1149 			if (err)
1150 				goto done;
1151 		}
1152 		err = read_packed_tree_privsep(tree, pack,
1153 		    packidx, idx, id);
1154 	} else if (err->code == GOT_ERR_NO_OBJ) {
1155 		int fd;
1156 
1157 		err = got_object_open_loose_fd(&fd, id, repo);
1158 		if (err)
1159 			return err;
1160 		err = read_tree_privsep(tree, fd, id, repo);
1161 	}
1162 
1163 	if (err == NULL) {
1164 		(*tree)->refcnt++;
1165 		err = got_repo_cache_tree(repo, id, *tree);
1166 	}
1167 done:
1168 	free(path_packfile);
1169 	return err;
1170 }
1171 
1172 const struct got_error *
1173 got_object_open_as_tree(struct got_tree_object **tree,
1174     struct got_repository *repo, struct got_object_id *id)
1175 {
1176 	*tree = got_repo_get_cached_tree(repo, id);
1177 	if (*tree != NULL) {
1178 		(*tree)->refcnt++;
1179 		return NULL;
1180 	}
1181 
1182 	return open_tree(tree, repo, id, 0);
1183 }
1184 
1185 const struct got_error *
1186 got_object_tree_open(struct got_tree_object **tree,
1187     struct got_repository *repo, struct got_object *obj)
1188 {
1189 	return open_tree(tree, repo, got_object_get_id(obj), 1);
1190 }
1191 
1192 int
1193 got_object_tree_get_nentries(struct got_tree_object *tree)
1194 {
1195 	return tree->nentries;
1196 }
1197 
1198 struct got_tree_entry *
1199 got_object_tree_get_first_entry(struct got_tree_object *tree)
1200 {
1201 	return got_object_tree_get_entry(tree, 0);
1202 }
1203 
1204 struct got_tree_entry *
1205 got_object_tree_get_last_entry(struct got_tree_object *tree)
1206 {
1207 	return got_object_tree_get_entry(tree, tree->nentries - 1);
1208 }
1209 
1210 struct got_tree_entry *
1211 got_object_tree_get_entry(struct got_tree_object *tree, int i)
1212 {
1213 	if (i < 0 || i >= tree->nentries)
1214 		return NULL;
1215 	return &tree->entries[i];
1216 }
1217 
1218 mode_t
1219 got_tree_entry_get_mode(struct got_tree_entry *te)
1220 {
1221 	return te->mode;
1222 }
1223 
1224 const char *
1225 got_tree_entry_get_name(struct got_tree_entry *te)
1226 {
1227 	return &te->name[0];
1228 }
1229 
1230 struct got_object_id *
1231 got_tree_entry_get_id(struct got_tree_entry *te)
1232 {
1233 	return &te->id;
1234 }
1235 
1236 const struct got_error *
1237 got_object_blob_read_to_str(char **s, struct got_blob_object *blob)
1238 {
1239 	const struct got_error *err = NULL;
1240 	size_t len, totlen, hdrlen, offset;
1241 
1242 	*s = NULL;
1243 
1244 	hdrlen = got_object_blob_get_hdrlen(blob);
1245 	totlen = 0;
1246 	offset = 0;
1247 	do {
1248 		char *p;
1249 
1250 		err = got_object_blob_read_block(&len, blob);
1251 		if (err)
1252 			return err;
1253 
1254 		if (len == 0)
1255 			break;
1256 
1257 		totlen += len - hdrlen;
1258 		p = realloc(*s, totlen + 1);
1259 		if (p == NULL) {
1260 			err = got_error_from_errno("realloc");
1261 			free(*s);
1262 			*s = NULL;
1263 			return err;
1264 		}
1265 		*s = p;
1266 		/* Skip blob object header first time around. */
1267 		memcpy(*s + offset,
1268 		    got_object_blob_get_read_buf(blob) + hdrlen, len - hdrlen);
1269 		hdrlen = 0;
1270 		offset = totlen;
1271 	} while (len > 0);
1272 
1273 	(*s)[totlen] = '\0';
1274 	return NULL;
1275 }
1276 
1277 const struct got_error *
1278 got_tree_entry_get_symlink_target(char **link_target, struct got_tree_entry *te,
1279     struct got_repository *repo)
1280 {
1281 	const struct got_error *err = NULL;
1282 	struct got_blob_object *blob = NULL;
1283 
1284 	*link_target = NULL;
1285 
1286 	if (!got_object_tree_entry_is_symlink(te))
1287 		return got_error(GOT_ERR_TREE_ENTRY_TYPE);
1288 
1289 	err = got_object_open_as_blob(&blob, repo,
1290 	    got_tree_entry_get_id(te), PATH_MAX);
1291 	if (err)
1292 		return err;
1293 
1294 	err = got_object_blob_read_to_str(link_target, blob);
1295 	got_object_blob_close(blob);
1296 	if (err) {
1297 		free(*link_target);
1298 		*link_target = NULL;
1299 	}
1300 	return err;
1301 }
1302 
1303 int
1304 got_tree_entry_get_index(struct got_tree_entry *te)
1305 {
1306 	return te->idx;
1307 }
1308 
1309 struct got_tree_entry *
1310 got_tree_entry_get_next(struct got_tree_object *tree,
1311     struct got_tree_entry *te)
1312 {
1313 	return got_object_tree_get_entry(tree, te->idx + 1);
1314 }
1315 
1316 struct got_tree_entry *
1317 got_tree_entry_get_prev(struct got_tree_object *tree,
1318     struct got_tree_entry *te)
1319 {
1320 	return got_object_tree_get_entry(tree, te->idx - 1);
1321 }
1322 
1323 static const struct got_error *
1324 request_packed_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
1325     struct got_pack *pack, struct got_packidx *packidx, int idx,
1326     struct got_object_id *id)
1327 {
1328 	const struct got_error *err = NULL;
1329 	struct imsgbuf *ibuf = pack->privsep_child->ibuf;
1330 	int outfd_child;
1331 
1332 	 err = pack_child_send_tempfiles(ibuf, pack);
1333 	 if (err)
1334 		return err;
1335 
1336 	outfd_child = dup(outfd);
1337 	if (outfd_child == -1)
1338 		return got_error_from_errno("dup");
1339 
1340 	err = got_privsep_send_blob_req(pack->privsep_child->ibuf, -1, id, idx);
1341 	if (err)
1342 		return err;
1343 
1344 	err = got_privsep_send_blob_outfd(pack->privsep_child->ibuf,
1345 	    outfd_child);
1346 	if (err) {
1347 		return err;
1348 	}
1349 
1350 	err = got_privsep_recv_blob(outbuf, size, hdrlen,
1351 	    pack->privsep_child->ibuf);
1352 	if (err)
1353 		return err;
1354 
1355 	if (lseek(outfd, SEEK_SET, 0) == -1)
1356 		err = got_error_from_errno("lseek");
1357 
1358 	return err;
1359 }
1360 
1361 static const struct got_error *
1362 read_packed_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1363     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
1364     struct got_object_id *id)
1365 {
1366 	const struct got_error *err = NULL;
1367 
1368 	if (pack->privsep_child == NULL) {
1369 		err = start_pack_privsep_child(pack, packidx);
1370 		if (err)
1371 			return err;
1372 	}
1373 
1374 	return request_packed_blob(outbuf, size, hdrlen, outfd, pack, packidx,
1375 	    idx, id);
1376 }
1377 
1378 static const struct got_error *
1379 request_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
1380     int infd, struct got_object_id *id, struct imsgbuf *ibuf)
1381 {
1382 	const struct got_error *err = NULL;
1383 	int outfd_child;
1384 
1385 	outfd_child = dup(outfd);
1386 	if (outfd_child == -1)
1387 		return got_error_from_errno("dup");
1388 
1389 	err = got_privsep_send_blob_req(ibuf, infd, id, -1);
1390 	if (err)
1391 		return err;
1392 
1393 	err = got_privsep_send_blob_outfd(ibuf, outfd_child);
1394 	if (err)
1395 		return err;
1396 
1397 	err = got_privsep_recv_blob(outbuf, size, hdrlen, ibuf);
1398 	if (err)
1399 		return err;
1400 
1401 	if (lseek(outfd, SEEK_SET, 0) == -1)
1402 		return got_error_from_errno("lseek");
1403 
1404 	return err;
1405 }
1406 
1407 static const struct got_error *
1408 read_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1409     int outfd, int infd, struct got_object_id *id, struct got_repository *repo)
1410 {
1411 	const struct got_error *err;
1412 	int imsg_fds[2];
1413 	pid_t pid;
1414 	struct imsgbuf *ibuf;
1415 
1416 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd != -1) {
1417 		ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf;
1418 		return request_blob(outbuf, size, hdrlen, outfd, infd, id,
1419 		    ibuf);
1420 	}
1421 
1422 	ibuf = calloc(1, sizeof(*ibuf));
1423 	if (ibuf == NULL)
1424 		return got_error_from_errno("calloc");
1425 
1426 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1427 		err = got_error_from_errno("socketpair");
1428 		free(ibuf);
1429 		return err;
1430 	}
1431 
1432 	pid = fork();
1433 	if (pid == -1) {
1434 		err = got_error_from_errno("fork");
1435 		free(ibuf);
1436 		return err;
1437 	}
1438 	else if (pid == 0) {
1439 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_BLOB,
1440 		    repo->path);
1441 		/* not reached */
1442 	}
1443 
1444 	if (close(imsg_fds[1]) == -1) {
1445 		err = got_error_from_errno("close");
1446 		free(ibuf);
1447 		return err;
1448 	}
1449 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd =
1450 	    imsg_fds[0];
1451 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].pid = pid;
1452 	imsg_init(ibuf, imsg_fds[0]);
1453 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf = ibuf;
1454 
1455 	return request_blob(outbuf, size, hdrlen, outfd, infd, id, ibuf);
1456 }
1457 
1458 static const struct got_error *
1459 open_blob(struct got_blob_object **blob, struct got_repository *repo,
1460     struct got_object_id *id, size_t blocksize)
1461 {
1462 	const struct got_error *err = NULL;
1463 	struct got_packidx *packidx = NULL;
1464 	int idx;
1465 	char *path_packfile = NULL;
1466 	uint8_t *outbuf;
1467 	int outfd;
1468 	size_t size, hdrlen;
1469 	struct stat sb;
1470 
1471 	*blob = calloc(1, sizeof(**blob));
1472 	if (*blob == NULL)
1473 		return got_error_from_errno("calloc");
1474 
1475 	outfd = got_opentempfd();
1476 	if (outfd == -1)
1477 		return got_error_from_errno("got_opentempfd");
1478 
1479 	(*blob)->read_buf = malloc(blocksize);
1480 	if ((*blob)->read_buf == NULL) {
1481 		err = got_error_from_errno("malloc");
1482 		goto done;
1483 	}
1484 
1485 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1486 	if (err == NULL) {
1487 		struct got_pack *pack = NULL;
1488 
1489 		err = got_packidx_get_packfile_path(&path_packfile,
1490 		    packidx->path_packidx);
1491 		if (err)
1492 			goto done;
1493 
1494 		pack = got_repo_get_cached_pack(repo, path_packfile);
1495 		if (pack == NULL) {
1496 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1497 			    packidx);
1498 			if (err)
1499 				goto done;
1500 		}
1501 		err = read_packed_blob_privsep(&outbuf, &size, &hdrlen, outfd,
1502 		    pack, packidx, idx, id);
1503 	} else if (err->code == GOT_ERR_NO_OBJ) {
1504 		int infd;
1505 
1506 		err = got_object_open_loose_fd(&infd, id, repo);
1507 		if (err)
1508 			goto done;
1509 		err = read_blob_privsep(&outbuf, &size, &hdrlen, outfd, infd,
1510 		    id, repo);
1511 	}
1512 	if (err)
1513 		goto done;
1514 
1515 	if (hdrlen > size) {
1516 		err = got_error(GOT_ERR_BAD_OBJ_HDR);
1517 		goto done;
1518 	}
1519 
1520 	if (outbuf) {
1521 		if (close(outfd) == -1 && err == NULL)
1522 			err = got_error_from_errno("close");
1523 		outfd = -1;
1524 		(*blob)->f = fmemopen(outbuf, size, "rb");
1525 		if ((*blob)->f == NULL) {
1526 			err = got_error_from_errno("fmemopen");
1527 			free(outbuf);
1528 			goto done;
1529 		}
1530 		(*blob)->data = outbuf;
1531 	} else {
1532 		if (fstat(outfd, &sb) == -1) {
1533 			err = got_error_from_errno("fstat");
1534 			goto done;
1535 		}
1536 
1537 		if (sb.st_size != size) {
1538 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1539 			goto done;
1540 		}
1541 
1542 		(*blob)->f = fdopen(outfd, "rb");
1543 		if ((*blob)->f == NULL) {
1544 			err = got_error_from_errno("fdopen");
1545 			close(outfd);
1546 			outfd = -1;
1547 			goto done;
1548 		}
1549 	}
1550 
1551 	(*blob)->hdrlen = hdrlen;
1552 	(*blob)->blocksize = blocksize;
1553 	memcpy(&(*blob)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
1554 
1555 done:
1556 	free(path_packfile);
1557 	if (err) {
1558 		if (*blob) {
1559 			got_object_blob_close(*blob);
1560 			*blob = NULL;
1561 		} else if (outfd != -1)
1562 			close(outfd);
1563 	}
1564 	return err;
1565 }
1566 
1567 const struct got_error *
1568 got_object_open_as_blob(struct got_blob_object **blob,
1569     struct got_repository *repo, struct got_object_id *id,
1570     size_t blocksize)
1571 {
1572 	return open_blob(blob, repo, id, blocksize);
1573 }
1574 
1575 const struct got_error *
1576 got_object_blob_open(struct got_blob_object **blob,
1577     struct got_repository *repo, struct got_object *obj, size_t blocksize)
1578 {
1579 	return open_blob(blob, repo, got_object_get_id(obj), blocksize);
1580 }
1581 
1582 const struct got_error *
1583 got_object_blob_close(struct got_blob_object *blob)
1584 {
1585 	const struct got_error *err = NULL;
1586 	free(blob->read_buf);
1587 	if (blob->f && fclose(blob->f) == EOF)
1588 		err = got_error_from_errno("fclose");
1589 	free(blob->data);
1590 	free(blob);
1591 	return err;
1592 }
1593 
1594 void
1595 got_object_blob_rewind(struct got_blob_object *blob)
1596 {
1597 	if (blob->f)
1598 		rewind(blob->f);
1599 }
1600 
1601 char *
1602 got_object_blob_id_str(struct got_blob_object *blob, char *buf, size_t size)
1603 {
1604 	return got_sha1_digest_to_str(blob->id.sha1, buf, size);
1605 }
1606 
1607 size_t
1608 got_object_blob_get_hdrlen(struct got_blob_object *blob)
1609 {
1610 	return blob->hdrlen;
1611 }
1612 
1613 const uint8_t *
1614 got_object_blob_get_read_buf(struct got_blob_object *blob)
1615 {
1616 	return blob->read_buf;
1617 }
1618 
1619 const struct got_error *
1620 got_object_blob_read_block(size_t *outlenp, struct got_blob_object *blob)
1621 {
1622 	size_t n;
1623 
1624 	n = fread(blob->read_buf, 1, blob->blocksize, blob->f);
1625 	if (n == 0 && ferror(blob->f))
1626 		return got_ferror(blob->f, GOT_ERR_IO);
1627 	*outlenp = n;
1628 	return NULL;
1629 }
1630 
1631 const struct got_error *
1632 got_object_blob_dump_to_file(off_t *filesize, int *nlines,
1633     off_t **line_offsets, FILE *outfile, struct got_blob_object *blob)
1634 {
1635 	const struct got_error *err = NULL;
1636 	size_t n, len, hdrlen;
1637 	const uint8_t *buf;
1638 	int i;
1639 	const int alloc_chunksz = 512;
1640 	size_t nalloc = 0;
1641 	off_t off = 0, total_len = 0;
1642 
1643 	if (line_offsets)
1644 		*line_offsets = NULL;
1645 	if (filesize)
1646 		*filesize = 0;
1647 	if (nlines)
1648 		*nlines = 0;
1649 
1650 	hdrlen = got_object_blob_get_hdrlen(blob);
1651 	do {
1652 		err = got_object_blob_read_block(&len, blob);
1653 		if (err)
1654 			return err;
1655 		if (len == 0)
1656 			break;
1657 		buf = got_object_blob_get_read_buf(blob);
1658 		i = hdrlen;
1659 		if (nlines) {
1660 			if (line_offsets && *line_offsets == NULL) {
1661 				/* Have some data but perhaps no '\n'. */
1662 				*nlines = 1;
1663 				nalloc = alloc_chunksz;
1664 				*line_offsets = calloc(nalloc,
1665 				    sizeof(**line_offsets));
1666 				if (*line_offsets == NULL)
1667 					return got_error_from_errno("calloc");
1668 
1669 				/* Skip forward over end of first line. */
1670 				while (i < len) {
1671 					if (buf[i] == '\n')
1672 						break;
1673 					i++;
1674 				}
1675 			}
1676 			/* Scan '\n' offsets in remaining chunk of data. */
1677 			while (i < len) {
1678 				if (buf[i] != '\n') {
1679 					i++;
1680 					continue;
1681 				}
1682 				(*nlines)++;
1683 				if (line_offsets && nalloc < *nlines) {
1684 					size_t n = *nlines + alloc_chunksz;
1685 					off_t *o = recallocarray(*line_offsets,
1686 					    nalloc, n, sizeof(**line_offsets));
1687 					if (o == NULL) {
1688 						free(*line_offsets);
1689 						*line_offsets = NULL;
1690 						return got_error_from_errno(
1691 						    "recallocarray");
1692 					}
1693 					*line_offsets = o;
1694 					nalloc = n;
1695 				}
1696 				if (line_offsets) {
1697 					off = total_len + i - hdrlen + 1;
1698 					(*line_offsets)[*nlines - 1] = off;
1699 				}
1700 				i++;
1701 			}
1702 		}
1703 		/* Skip blob object header first time around. */
1704 		n = fwrite(buf + hdrlen, 1, len - hdrlen, outfile);
1705 		if (n != len - hdrlen)
1706 			return got_ferror(outfile, GOT_ERR_IO);
1707 		total_len += len - hdrlen;
1708 		hdrlen = 0;
1709 	} while (len != 0);
1710 
1711 	if (fflush(outfile) != 0)
1712 		return got_error_from_errno("fflush");
1713 	rewind(outfile);
1714 
1715 	if (filesize)
1716 		*filesize = total_len;
1717 
1718 	return NULL;
1719 }
1720 
1721 static const struct got_error *
1722 request_packed_tag(struct got_tag_object **tag, struct got_pack *pack,
1723     int pack_idx, struct got_object_id *id)
1724 {
1725 	const struct got_error *err = NULL;
1726 
1727 	err = got_privsep_send_tag_req(pack->privsep_child->ibuf, -1, id,
1728 	    pack_idx);
1729 	if (err)
1730 		return err;
1731 
1732 	return got_privsep_recv_tag(tag, pack->privsep_child->ibuf);
1733 }
1734 
1735 static const struct got_error *
1736 read_packed_tag_privsep(struct got_tag_object **tag,
1737     struct got_pack *pack, struct got_packidx *packidx, int idx,
1738     struct got_object_id *id)
1739 {
1740 	const struct got_error *err = NULL;
1741 
1742 	if (pack->privsep_child)
1743 		return request_packed_tag(tag, pack, idx, id);
1744 
1745 	err = start_pack_privsep_child(pack, packidx);
1746 	if (err)
1747 		return err;
1748 
1749 	return request_packed_tag(tag, pack, idx, id);
1750 }
1751 
1752 static const struct got_error *
1753 request_tag(struct got_tag_object **tag, struct got_repository *repo,
1754     int fd, struct got_object_id *id)
1755 {
1756 	const struct got_error *err = NULL;
1757 	struct imsgbuf *ibuf;
1758 
1759 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf;
1760 
1761 	err = got_privsep_send_tag_req(ibuf, fd, id, -1);
1762 	if (err)
1763 		return err;
1764 
1765 	return got_privsep_recv_tag(tag, ibuf);
1766 }
1767 
1768 static const struct got_error *
1769 read_tag_privsep(struct got_tag_object **tag, int obj_fd,
1770     struct got_object_id *id, struct got_repository *repo)
1771 {
1772 	const struct got_error *err;
1773 	int imsg_fds[2];
1774 	pid_t pid;
1775 	struct imsgbuf *ibuf;
1776 
1777 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd != -1)
1778 		return request_tag(tag, repo, obj_fd, id);
1779 
1780 	ibuf = calloc(1, sizeof(*ibuf));
1781 	if (ibuf == NULL)
1782 		return got_error_from_errno("calloc");
1783 
1784 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1785 		err = got_error_from_errno("socketpair");
1786 		free(ibuf);
1787 		return err;
1788 	}
1789 
1790 	pid = fork();
1791 	if (pid == -1) {
1792 		err = got_error_from_errno("fork");
1793 		free(ibuf);
1794 		return err;
1795 	}
1796 	else if (pid == 0) {
1797 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TAG,
1798 		    repo->path);
1799 		/* not reached */
1800 	}
1801 
1802 	if (close(imsg_fds[1]) == -1) {
1803 		err = got_error_from_errno("close");
1804 		free(ibuf);
1805 		return err;
1806 	}
1807 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd =
1808 	    imsg_fds[0];
1809 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].pid = pid;
1810 	imsg_init(ibuf, imsg_fds[0]);
1811 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf = ibuf;
1812 
1813 	return request_tag(tag, repo, obj_fd, id);
1814 }
1815 
1816 static const struct got_error *
1817 open_tag(struct got_tag_object **tag, struct got_repository *repo,
1818     struct got_object_id *id, int check_cache)
1819 {
1820 	const struct got_error *err = NULL;
1821 	struct got_packidx *packidx = NULL;
1822 	int idx;
1823 	char *path_packfile = NULL;
1824 	struct got_object *obj = NULL;
1825 	int obj_type = GOT_OBJ_TYPE_ANY;
1826 
1827 	if (check_cache) {
1828 		*tag = got_repo_get_cached_tag(repo, id);
1829 		if (*tag != NULL) {
1830 			(*tag)->refcnt++;
1831 			return NULL;
1832 		}
1833 	} else
1834 		*tag = NULL;
1835 
1836 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1837 	if (err == NULL) {
1838 		struct got_pack *pack = NULL;
1839 
1840 		err = got_packidx_get_packfile_path(&path_packfile,
1841 		    packidx->path_packidx);
1842 		if (err)
1843 			return err;
1844 
1845 		pack = got_repo_get_cached_pack(repo, path_packfile);
1846 		if (pack == NULL) {
1847 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1848 			    packidx);
1849 			if (err)
1850 				goto done;
1851 		}
1852 
1853 		/* Beware of "lightweight" tags: Check object type first. */
1854 		err = read_packed_object_privsep(&obj, repo, pack, packidx,
1855 		    idx, id);
1856 		if (err)
1857 			goto done;
1858 		obj_type = obj->type;
1859 		got_object_close(obj);
1860 		if (obj_type != GOT_OBJ_TYPE_TAG) {
1861 			err = got_error(GOT_ERR_OBJ_TYPE);
1862 			goto done;
1863 		}
1864 		err = read_packed_tag_privsep(tag, pack, packidx, idx, id);
1865 	} else if (err->code == GOT_ERR_NO_OBJ) {
1866 		int fd;
1867 
1868 		err = got_object_open_loose_fd(&fd, id, repo);
1869 		if (err)
1870 			return err;
1871 		err = got_object_read_header_privsep(&obj, id, repo, fd);
1872 		if (err)
1873 			return err;
1874 		obj_type = obj->type;
1875 		got_object_close(obj);
1876 		if (obj_type != GOT_OBJ_TYPE_TAG)
1877 			return got_error(GOT_ERR_OBJ_TYPE);
1878 
1879 		err = got_object_open_loose_fd(&fd, id, repo);
1880 		if (err)
1881 			return err;
1882 		err = read_tag_privsep(tag, fd, id, repo);
1883 	}
1884 
1885 	if (err == NULL) {
1886 		(*tag)->refcnt++;
1887 		err = got_repo_cache_tag(repo, id, *tag);
1888 	}
1889 done:
1890 	free(path_packfile);
1891 	return err;
1892 }
1893 
1894 const struct got_error *
1895 got_object_open_as_tag(struct got_tag_object **tag,
1896     struct got_repository *repo, struct got_object_id *id)
1897 {
1898 	*tag = got_repo_get_cached_tag(repo, id);
1899 	if (*tag != NULL) {
1900 		(*tag)->refcnt++;
1901 		return NULL;
1902 	}
1903 
1904 	return open_tag(tag, repo, id, 0);
1905 }
1906 
1907 const struct got_error *
1908 got_object_tag_open(struct got_tag_object **tag,
1909     struct got_repository *repo, struct got_object *obj)
1910 {
1911 	return open_tag(tag, repo, got_object_get_id(obj), 1);
1912 }
1913 
1914 const char *
1915 got_object_tag_get_name(struct got_tag_object *tag)
1916 {
1917 	return tag->tag;
1918 }
1919 
1920 int
1921 got_object_tag_get_object_type(struct got_tag_object *tag)
1922 {
1923 	return tag->obj_type;
1924 }
1925 
1926 struct got_object_id *
1927 got_object_tag_get_object_id(struct got_tag_object *tag)
1928 {
1929 	return &tag->id;
1930 }
1931 
1932 time_t
1933 got_object_tag_get_tagger_time(struct got_tag_object *tag)
1934 {
1935 	return tag->tagger_time;
1936 }
1937 
1938 time_t
1939 got_object_tag_get_tagger_gmtoff(struct got_tag_object *tag)
1940 {
1941 	return tag->tagger_gmtoff;
1942 }
1943 
1944 const char *
1945 got_object_tag_get_tagger(struct got_tag_object *tag)
1946 {
1947 	return tag->tagger;
1948 }
1949 
1950 const char *
1951 got_object_tag_get_message(struct got_tag_object *tag)
1952 {
1953 	return tag->tagmsg;
1954 }
1955 
1956 static struct got_tree_entry *
1957 find_entry_by_name(struct got_tree_object *tree, const char *name, size_t len)
1958 {
1959 	int i;
1960 
1961 	/* Note that tree entries are sorted in strncmp() order. */
1962 	for (i = 0; i < tree->nentries; i++) {
1963 		struct got_tree_entry *te = &tree->entries[i];
1964 		int cmp = strncmp(te->name, name, len);
1965 		if (cmp < 0)
1966 			continue;
1967 		if (cmp > 0)
1968 			break;
1969 		if (te->name[len] == '\0')
1970 			return te;
1971 	}
1972 	return NULL;
1973 }
1974 
1975 struct got_tree_entry *
1976 got_object_tree_find_entry(struct got_tree_object *tree, const char *name)
1977 {
1978 	return find_entry_by_name(tree, name, strlen(name));
1979 }
1980 
1981 const struct got_error *
1982 got_object_tree_find_path(struct got_object_id **id, mode_t *mode,
1983     struct got_repository *repo, struct got_tree_object *tree,
1984     const char *path)
1985 {
1986 	const struct got_error *err = NULL;
1987 	struct got_tree_object *subtree = NULL;
1988 	struct got_tree_entry *te = NULL;
1989 	const char *seg, *s;
1990 	size_t seglen;
1991 
1992 	*id = NULL;
1993 
1994 	s = path;
1995 	while (s[0] == '/')
1996 		s++;
1997 	seg = s;
1998 	seglen = 0;
1999 	subtree = tree;
2000 	while (*s) {
2001 		struct got_tree_object *next_tree;
2002 
2003 		if (*s != '/') {
2004 			s++;
2005 			seglen++;
2006 			if (*s)
2007 				continue;
2008 		}
2009 
2010 		te = find_entry_by_name(subtree, seg, seglen);
2011 		if (te == NULL) {
2012 			err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
2013 			goto done;
2014 		}
2015 
2016 		if (*s == '\0')
2017 			break;
2018 
2019 		seg = s + 1;
2020 		seglen = 0;
2021 		s++;
2022 		if (*s) {
2023 			err = got_object_open_as_tree(&next_tree, repo,
2024 			    &te->id);
2025 			te = NULL;
2026 			if (err)
2027 				goto done;
2028 			if (subtree != tree)
2029 				got_object_tree_close(subtree);
2030 			subtree = next_tree;
2031 		}
2032 	}
2033 
2034 	if (te) {
2035 		*id = got_object_id_dup(&te->id);
2036 		if (*id == NULL)
2037 			return got_error_from_errno("got_object_id_dup");
2038 		if (mode)
2039 			*mode = te->mode;
2040 	} else
2041 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
2042 done:
2043 	if (subtree && subtree != tree)
2044 		got_object_tree_close(subtree);
2045 	return err;
2046 }
2047 const struct got_error *
2048 got_object_id_by_path(struct got_object_id **id, struct got_repository *repo,
2049     struct got_commit_object *commit, const char *path)
2050 {
2051 	const struct got_error *err = NULL;
2052 	struct got_tree_object *tree = NULL;
2053 
2054 	*id = NULL;
2055 
2056 	/* Handle opening of root of commit's tree. */
2057 	if (got_path_is_root_dir(path)) {
2058 		*id = got_object_id_dup(commit->tree_id);
2059 		if (*id == NULL)
2060 			err = got_error_from_errno("got_object_id_dup");
2061 	} else {
2062 		err = got_object_open_as_tree(&tree, repo, commit->tree_id);
2063 		if (err)
2064 			goto done;
2065 		err = got_object_tree_find_path(id, NULL, repo, tree, path);
2066 	}
2067 done:
2068 	if (tree)
2069 		got_object_tree_close(tree);
2070 	return err;
2071 }
2072 
2073 /*
2074  * Normalize file mode bits to avoid false positive tree entry differences
2075  * in case tree entries have unexpected mode bits set.
2076  */
2077 static mode_t
2078 normalize_mode_for_comparison(mode_t mode)
2079 {
2080 	/*
2081 	 * For directories, the only relevant bit is the IFDIR bit.
2082 	 * This allows us to detect paths changing from a directory
2083 	 * to a file and vice versa.
2084 	 */
2085 	if (S_ISDIR(mode))
2086 		return mode & S_IFDIR;
2087 
2088 	/*
2089 	 * For symlinks, the only relevant bit is the IFLNK bit.
2090 	 * This allows us to detect paths changing from a symlinks
2091 	 * to a file or directory and vice versa.
2092 	 */
2093 	if (S_ISLNK(mode))
2094 		return mode & S_IFLNK;
2095 
2096 	/* For files, the only change we care about is the executable bit. */
2097 	return mode & S_IXUSR;
2098 }
2099 
2100 const struct got_error *
2101 got_object_tree_path_changed(int *changed,
2102     struct got_tree_object *tree01, struct got_tree_object *tree02,
2103     const char *path, struct got_repository *repo)
2104 {
2105 	const struct got_error *err = NULL;
2106 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
2107 	struct got_tree_entry *te1 = NULL, *te2 = NULL;
2108 	const char *seg, *s;
2109 	size_t seglen;
2110 
2111 	*changed = 0;
2112 
2113 	/* We not do support comparing the root path. */
2114 	if (got_path_is_root_dir(path))
2115 		return got_error_path(path, GOT_ERR_BAD_PATH);
2116 
2117 	tree1 = tree01;
2118 	tree2 = tree02;
2119 	s = path;
2120 	while (*s == '/')
2121 		s++;
2122 	seg = s;
2123 	seglen = 0;
2124 	while (*s) {
2125 		struct got_tree_object *next_tree1, *next_tree2;
2126 		mode_t mode1, mode2;
2127 
2128 		if (*s != '/') {
2129 			s++;
2130 			seglen++;
2131 			if (*s)
2132 				continue;
2133 		}
2134 
2135 		te1 = find_entry_by_name(tree1, seg, seglen);
2136 		if (te1 == NULL) {
2137 			err = got_error(GOT_ERR_NO_OBJ);
2138 			goto done;
2139 		}
2140 
2141 		if (tree2)
2142 			te2 = find_entry_by_name(tree2, seg, seglen);
2143 
2144 		if (te2) {
2145 			mode1 = normalize_mode_for_comparison(te1->mode);
2146 			mode2 = normalize_mode_for_comparison(te2->mode);
2147 			if (mode1 != mode2) {
2148 				*changed = 1;
2149 				goto done;
2150 			}
2151 
2152 			if (got_object_id_cmp(&te1->id, &te2->id) == 0) {
2153 				*changed = 0;
2154 				goto done;
2155 			}
2156 		}
2157 
2158 		if (*s == '\0') { /* final path element */
2159 			*changed = 1;
2160 			goto done;
2161 		}
2162 
2163 		seg = s + 1;
2164 		s++;
2165 		seglen = 0;
2166 		if (*s) {
2167 			err = got_object_open_as_tree(&next_tree1, repo,
2168 			    &te1->id);
2169 			te1 = NULL;
2170 			if (err)
2171 				goto done;
2172 			if (tree1 != tree01)
2173 				got_object_tree_close(tree1);
2174 			tree1 = next_tree1;
2175 
2176 			if (te2) {
2177 				err = got_object_open_as_tree(&next_tree2, repo,
2178 				    &te2->id);
2179 				te2 = NULL;
2180 				if (err)
2181 					goto done;
2182 				if (tree2 != tree02)
2183 					got_object_tree_close(tree2);
2184 				tree2 = next_tree2;
2185 			} else if (tree2) {
2186 				if (tree2 != tree02)
2187 					got_object_tree_close(tree2);
2188 				tree2 = NULL;
2189 			}
2190 		}
2191 	}
2192 done:
2193 	if (tree1 && tree1 != tree01)
2194 		got_object_tree_close(tree1);
2195 	if (tree2 && tree2 != tree02)
2196 		got_object_tree_close(tree2);
2197 	return err;
2198 }
2199 
2200 const struct got_error *
2201 got_object_tree_entry_dup(struct got_tree_entry **new_te,
2202     struct got_tree_entry *te)
2203 {
2204 	const struct got_error *err = NULL;
2205 
2206 	*new_te = calloc(1, sizeof(**new_te));
2207 	if (*new_te == NULL)
2208 		return got_error_from_errno("calloc");
2209 
2210 	(*new_te)->mode = te->mode;
2211 	memcpy((*new_te)->name, te->name, sizeof((*new_te)->name));
2212 	memcpy(&(*new_te)->id, &te->id, sizeof((*new_te)->id));
2213 	return err;
2214 }
2215 
2216 int
2217 got_object_tree_entry_is_submodule(struct got_tree_entry *te)
2218 {
2219 	return (te->mode & S_IFMT) == (S_IFDIR | S_IFLNK);
2220 }
2221 
2222 int
2223 got_object_tree_entry_is_symlink(struct got_tree_entry *te)
2224 {
2225 	/* S_IFDIR check avoids confusing symlinks with submodules. */
2226 	return ((te->mode & (S_IFDIR | S_IFLNK)) == S_IFLNK);
2227 }
2228 
2229 static const struct got_error *
2230 resolve_symlink(char **link_target, const char *path,
2231     struct got_commit_object *commit, struct got_repository *repo)
2232 {
2233 	const struct got_error *err = NULL;
2234 	char buf[PATH_MAX];
2235 	char *name, *parent_path = NULL;
2236 	struct got_object_id *tree_obj_id = NULL;
2237 	struct got_tree_object *tree = NULL;
2238 	struct got_tree_entry *te = NULL;
2239 
2240 	*link_target = NULL;
2241 
2242 	if (strlcpy(buf, path, sizeof(buf)) >= sizeof(buf))
2243 		return got_error(GOT_ERR_NO_SPACE);
2244 
2245 	name = basename(buf);
2246 	if (name == NULL)
2247 		return got_error_from_errno2("basename", path);
2248 
2249 	err = got_path_dirname(&parent_path, path);
2250 	if (err)
2251 		return err;
2252 
2253 	err = got_object_id_by_path(&tree_obj_id, repo, commit,
2254 	    parent_path);
2255 	if (err) {
2256 		if (err->code == GOT_ERR_NO_TREE_ENTRY) {
2257 			/* Display the complete path in error message. */
2258 			err = got_error_path(path, err->code);
2259 		}
2260 		goto done;
2261 	}
2262 
2263 	err = got_object_open_as_tree(&tree, repo, tree_obj_id);
2264 	if (err)
2265 		goto done;
2266 
2267 	te = got_object_tree_find_entry(tree, name);
2268 	if (te == NULL) {
2269 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
2270 		goto done;
2271 	}
2272 
2273 	if (got_object_tree_entry_is_symlink(te)) {
2274 		err = got_tree_entry_get_symlink_target(link_target, te, repo);
2275 		if (err)
2276 			goto done;
2277 		if (!got_path_is_absolute(*link_target)) {
2278 			char *abspath;
2279 			if (asprintf(&abspath, "%s/%s", parent_path,
2280 			    *link_target) == -1) {
2281 				err = got_error_from_errno("asprintf");
2282 				goto done;
2283 			}
2284 			free(*link_target);
2285 			*link_target = malloc(PATH_MAX);
2286 			if (*link_target == NULL) {
2287 				err = got_error_from_errno("malloc");
2288 				goto done;
2289 			}
2290 			err = got_canonpath(abspath, *link_target, PATH_MAX);
2291 			free(abspath);
2292 			if (err)
2293 				goto done;
2294 		}
2295 	}
2296 done:
2297 	free(tree_obj_id);
2298 	if (tree)
2299 		got_object_tree_close(tree);
2300 	if (err) {
2301 		free(*link_target);
2302 		*link_target = NULL;
2303 	}
2304 	return err;
2305 }
2306 
2307 const struct got_error *
2308 got_object_resolve_symlinks(char **link_target, const char *path,
2309     struct got_commit_object *commit, struct got_repository *repo)
2310 {
2311 	const struct got_error *err = NULL;
2312 	char *next_target = NULL;
2313 	int max_recursion = 40; /* matches Git */
2314 
2315 	*link_target = NULL;
2316 
2317 	do {
2318 		err = resolve_symlink(&next_target,
2319 		    *link_target ? *link_target : path, commit, repo);
2320 		if (err)
2321 			break;
2322 		if (next_target) {
2323 			free(*link_target);
2324 			if (--max_recursion == 0) {
2325 				err = got_error_path(path, GOT_ERR_RECURSION);
2326 				*link_target = NULL;
2327 				break;
2328 			}
2329 			*link_target = next_target;
2330 		}
2331 	} while (next_target);
2332 
2333 	return err;
2334 }
2335 
2336 const struct got_error *
2337 got_traverse_packed_commits(struct got_object_id_queue *traversed_commits,
2338     struct got_object_id *commit_id, const char *path,
2339     struct got_repository *repo)
2340 {
2341 	const struct got_error *err = NULL;
2342 	struct got_pack *pack = NULL;
2343 	struct got_packidx *packidx = NULL;
2344 	char *path_packfile = NULL;
2345 	struct got_commit_object *changed_commit = NULL;
2346 	struct got_object_id *changed_commit_id = NULL;
2347 	int idx;
2348 
2349 	err = got_repo_search_packidx(&packidx, &idx, repo, commit_id);
2350 	if (err) {
2351 		if (err->code != GOT_ERR_NO_OBJ)
2352 			return err;
2353 		return NULL;
2354 	}
2355 
2356 	err = got_packidx_get_packfile_path(&path_packfile,
2357 	    packidx->path_packidx);
2358 	if (err)
2359 		return err;
2360 
2361 	pack = got_repo_get_cached_pack(repo, path_packfile);
2362 	if (pack == NULL) {
2363 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
2364 		if (err)
2365 			goto done;
2366 	}
2367 
2368 	if (pack->privsep_child == NULL) {
2369 		err = start_pack_privsep_child(pack, packidx);
2370 		if (err)
2371 			goto done;
2372 	}
2373 
2374 	err = got_privsep_send_commit_traversal_request(
2375 	    pack->privsep_child->ibuf, commit_id, idx, path);
2376 	if (err)
2377 		goto done;
2378 
2379 	err = got_privsep_recv_traversed_commits(&changed_commit,
2380 	    &changed_commit_id, traversed_commits, pack->privsep_child->ibuf);
2381 	if (err)
2382 		goto done;
2383 
2384 	if (changed_commit) {
2385 		/*
2386 		 * Cache the commit in which the path was changed.
2387 		 * This commit might be opened again soon.
2388 		 */
2389 		changed_commit->refcnt++;
2390 		err = got_repo_cache_commit(repo, changed_commit_id,
2391 		    changed_commit);
2392 		got_object_commit_close(changed_commit);
2393 	}
2394 done:
2395 	free(path_packfile);
2396 	free(changed_commit_id);
2397 	return err;
2398 }