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