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