Gotweb

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