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Date:: Thu Jul 23 14:21:30 2020 UTC
Message:: add symlink support to 'got cherrypick'; test non-conflict cases only for now
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1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <sys/stat.h>
19 #include <sys/queue.h>
20 #include <sys/uio.h>
21 #include <sys/socket.h>
22 #include <sys/wait.h>
23 #include <sys/syslimits.h>
24 #include <sys/resource.h>
25 
26 #include <errno.h>
27 #include <fcntl.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <stdint.h>
32 #include <sha1.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 	hdrlen = got_object_blob_get_hdrlen(blob);
873 	totlen = 0;
874 	offset = 0;
875 	do {
876 		char *p;
877 
878 		err = got_object_blob_read_block(&len, blob);
879 		if (err)
880 			return err;
881 
882 		if (len == 0)
883 			break;
884 
885 		totlen += len - hdrlen;
886 		p = realloc(*s, totlen + 1);
887 		if (p == NULL) {
888 			err = got_error_from_errno("realloc");
889 			free(*s);
890 			*s = NULL;
891 			return err;
892 		}
893 		*s = p;
894 		/* Skip blob object header first time around. */
895 		memcpy(*s + offset,
896 		    got_object_blob_get_read_buf(blob) + hdrlen, len - hdrlen);
897 		hdrlen = 0;
898 		offset = totlen;
899 	} while (len > 0);
900 
901 	(*s)[totlen] = '\0';
902 	return NULL;
903 }
904 
905 const struct got_error *
906 got_tree_entry_get_symlink_target(char **link_target, struct got_tree_entry *te,
907     struct got_repository *repo)
908 {
909 	const struct got_error *err = NULL;
910 	struct got_blob_object *blob = NULL;
911 
912 	*link_target = NULL;
913 
914 	if (!got_object_tree_entry_is_symlink(te))
915 		return got_error(GOT_ERR_TREE_ENTRY_TYPE);
916 
917 	err = got_object_open_as_blob(&blob, repo,
918 	    got_tree_entry_get_id(te), PATH_MAX);
919 	if (err)
920 		return err;
921 
922 	err = got_object_blob_read_to_str(link_target, blob);
923 	got_object_blob_close(blob);
924 	if (err) {
925 		free(*link_target);
926 		*link_target = NULL;
927 	}
928 	return err;
929 }
930 
931 int
932 got_tree_entry_get_index(struct got_tree_entry *te)
933 {
934 	return te->idx;
935 }
936 
937 struct got_tree_entry *
938 got_tree_entry_get_next(struct got_tree_object *tree,
939     struct got_tree_entry *te)
940 {
941 	return got_object_tree_get_entry(tree, te->idx + 1);
942 }
943 
944 struct got_tree_entry *
945 got_tree_entry_get_prev(struct got_tree_object *tree,
946     struct got_tree_entry *te)
947 {
948 	return got_object_tree_get_entry(tree, te->idx - 1);
949 }
950 
951 static const struct got_error *
952 request_packed_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
953     struct got_pack *pack, struct got_packidx *packidx, int idx,
954     struct got_object_id *id)
955 {
956 	const struct got_error *err = NULL;
957 	int outfd_child;
958 	int basefd, accumfd; /* temporary files for delta application */
959 
960 	basefd = got_opentempfd();
961 	if (basefd == -1)
962 		return got_error_from_errno("got_opentempfd");
963 	accumfd = got_opentempfd();
964 	if (accumfd == -1)
965 		return got_error_from_errno("got_opentempfd");
966 
967 	outfd_child = dup(outfd);
968 	if (outfd_child == -1)
969 		return got_error_from_errno("dup");
970 
971 	err = got_privsep_send_blob_req(pack->privsep_child->ibuf, -1, id, idx);
972 	if (err)
973 		return err;
974 
975 	err = got_privsep_send_blob_outfd(pack->privsep_child->ibuf,
976 	    outfd_child);
977 	if (err) {
978 		close(basefd);
979 		close(accumfd);
980 		return err;
981 	}
982 
983 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
984 	    basefd);
985 	if (err) {
986 		close(accumfd);
987 		return err;
988 	}
989 
990 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
991 	    accumfd);
992 	if (err)
993 		return err;
994 
995 	err = got_privsep_recv_blob(outbuf, size, hdrlen,
996 	    pack->privsep_child->ibuf);
997 	if (err)
998 		return err;
999 
1000 	if (lseek(outfd, SEEK_SET, 0) == -1)
1001 		err = got_error_from_errno("lseek");
1002 
1003 	return err;
1004 }
1005 
1006 static const struct got_error *
1007 read_packed_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1008     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
1009     struct got_object_id *id)
1010 {
1011 	const struct got_error *err = NULL;
1012 
1013 	if (pack->privsep_child == NULL) {
1014 		err = start_pack_privsep_child(pack, packidx);
1015 		if (err)
1016 			return err;
1017 	}
1018 
1019 	return request_packed_blob(outbuf, size, hdrlen, outfd, pack, packidx,
1020 	    idx, id);
1021 }
1022 
1023 static const struct got_error *
1024 request_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
1025     int infd, struct imsgbuf *ibuf)
1026 {
1027 	const struct got_error *err = NULL;
1028 	int outfd_child;
1029 
1030 	outfd_child = dup(outfd);
1031 	if (outfd_child == -1)
1032 		return got_error_from_errno("dup");
1033 
1034 	err = got_privsep_send_blob_req(ibuf, infd, NULL, -1);
1035 	if (err)
1036 		return err;
1037 
1038 	err = got_privsep_send_blob_outfd(ibuf, outfd_child);
1039 	if (err)
1040 		return err;
1041 
1042 	err = got_privsep_recv_blob(outbuf, size, hdrlen, ibuf);
1043 	if (err)
1044 		return err;
1045 
1046 	if (lseek(outfd, SEEK_SET, 0) == -1)
1047 		return got_error_from_errno("lseek");
1048 
1049 	return err;
1050 }
1051 
1052 static const struct got_error *
1053 read_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1054     int outfd, int infd, struct got_repository *repo)
1055 {
1056 	const struct got_error *err;
1057 	int imsg_fds[2];
1058 	pid_t pid;
1059 	struct imsgbuf *ibuf;
1060 
1061 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd != -1) {
1062 		ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf;
1063 		return request_blob(outbuf, size, hdrlen, outfd, infd, ibuf);
1064 	}
1065 
1066 	ibuf = calloc(1, sizeof(*ibuf));
1067 	if (ibuf == NULL)
1068 		return got_error_from_errno("calloc");
1069 
1070 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1071 		err = got_error_from_errno("socketpair");
1072 		free(ibuf);
1073 		return err;
1074 	}
1075 
1076 	pid = fork();
1077 	if (pid == -1) {
1078 		err = got_error_from_errno("fork");
1079 		free(ibuf);
1080 		return err;
1081 	}
1082 	else if (pid == 0) {
1083 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_BLOB,
1084 		    repo->path);
1085 		/* not reached */
1086 	}
1087 
1088 	if (close(imsg_fds[1]) != 0) {
1089 		err = got_error_from_errno("close");
1090 		free(ibuf);
1091 		return err;
1092 	}
1093 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd =
1094 	    imsg_fds[0];
1095 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].pid = pid;
1096 	imsg_init(ibuf, imsg_fds[0]);
1097 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf = ibuf;
1098 
1099 	return request_blob(outbuf, size, hdrlen, outfd, infd, ibuf);
1100 }
1101 
1102 static const struct got_error *
1103 open_blob(struct got_blob_object **blob, struct got_repository *repo,
1104     struct got_object_id *id, size_t blocksize)
1105 {
1106 	const struct got_error *err = NULL;
1107 	struct got_packidx *packidx = NULL;
1108 	int idx;
1109 	char *path_packfile = NULL;
1110 	uint8_t *outbuf;
1111 	int outfd;
1112 	size_t size, hdrlen;
1113 	struct stat sb;
1114 
1115 	*blob = calloc(1, sizeof(**blob));
1116 	if (*blob == NULL)
1117 		return got_error_from_errno("calloc");
1118 
1119 	outfd = got_opentempfd();
1120 	if (outfd == -1)
1121 		return got_error_from_errno("got_opentempfd");
1122 
1123 	(*blob)->read_buf = malloc(blocksize);
1124 	if ((*blob)->read_buf == NULL) {
1125 		err = got_error_from_errno("malloc");
1126 		goto done;
1127 	}
1128 
1129 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1130 	if (err == NULL) {
1131 		struct got_pack *pack = NULL;
1132 
1133 		err = get_packfile_path(&path_packfile, packidx);
1134 		if (err)
1135 			goto done;
1136 
1137 		pack = got_repo_get_cached_pack(repo, path_packfile);
1138 		if (pack == NULL) {
1139 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1140 			    packidx);
1141 			if (err)
1142 				goto done;
1143 		}
1144 		err = read_packed_blob_privsep(&outbuf, &size, &hdrlen, outfd,
1145 		    pack, packidx, idx, id);
1146 	} else if (err->code == GOT_ERR_NO_OBJ) {
1147 		int infd;
1148 
1149 		err = open_loose_object(&infd, id, repo);
1150 		if (err)
1151 			goto done;
1152 		err = read_blob_privsep(&outbuf, &size, &hdrlen, outfd, infd,
1153 		    repo);
1154 	}
1155 	if (err)
1156 		goto done;
1157 
1158 	if (hdrlen > size) {
1159 		err = got_error(GOT_ERR_BAD_OBJ_HDR);
1160 		goto done;
1161 	}
1162 
1163 	if (outbuf) {
1164 		if (close(outfd) != 0 && err == NULL)
1165 			err = got_error_from_errno("close");
1166 		outfd = -1;
1167 		(*blob)->f = fmemopen(outbuf, size, "rb");
1168 		if ((*blob)->f == NULL) {
1169 			err = got_error_from_errno("fmemopen");
1170 			free(outbuf);
1171 			goto done;
1172 		}
1173 		(*blob)->data = outbuf;
1174 	} else {
1175 		if (fstat(outfd, &sb) == -1) {
1176 			err = got_error_from_errno("fstat");
1177 			goto done;
1178 		}
1179 
1180 		if (sb.st_size != size) {
1181 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1182 			goto done;
1183 		}
1184 
1185 		(*blob)->f = fdopen(outfd, "rb");
1186 		if ((*blob)->f == NULL) {
1187 			err = got_error_from_errno("fdopen");
1188 			close(outfd);
1189 			outfd = -1;
1190 			goto done;
1191 		}
1192 	}
1193 
1194 	(*blob)->hdrlen = hdrlen;
1195 	(*blob)->blocksize = blocksize;
1196 	memcpy(&(*blob)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
1197 
1198 done:
1199 	free(path_packfile);
1200 	if (err) {
1201 		if (*blob) {
1202 			got_object_blob_close(*blob);
1203 			*blob = NULL;
1204 		} else if (outfd != -1)
1205 			close(outfd);
1206 	}
1207 	return err;
1208 }
1209 
1210 const struct got_error *
1211 got_object_open_as_blob(struct got_blob_object **blob,
1212     struct got_repository *repo, struct got_object_id *id,
1213     size_t blocksize)
1214 {
1215 	return open_blob(blob, repo, id, blocksize);
1216 }
1217 
1218 const struct got_error *
1219 got_object_blob_open(struct got_blob_object **blob,
1220     struct got_repository *repo, struct got_object *obj, size_t blocksize)
1221 {
1222 	return open_blob(blob, repo, got_object_get_id(obj), blocksize);
1223 }
1224 
1225 const struct got_error *
1226 got_object_blob_close(struct got_blob_object *blob)
1227 {
1228 	const struct got_error *err = NULL;
1229 	free(blob->read_buf);
1230 	if (blob->f && fclose(blob->f) != 0)
1231 		err = got_error_from_errno("fclose");
1232 	free(blob->data);
1233 	free(blob);
1234 	return err;
1235 }
1236 
1237 void
1238 got_object_blob_rewind(struct got_blob_object *blob)
1239 {
1240 	if (blob->f)
1241 		rewind(blob->f);
1242 }
1243 
1244 char *
1245 got_object_blob_id_str(struct got_blob_object *blob, char *buf, size_t size)
1246 {
1247 	return got_sha1_digest_to_str(blob->id.sha1, buf, size);
1248 }
1249 
1250 size_t
1251 got_object_blob_get_hdrlen(struct got_blob_object *blob)
1252 {
1253 	return blob->hdrlen;
1254 }
1255 
1256 const uint8_t *
1257 got_object_blob_get_read_buf(struct got_blob_object *blob)
1258 {
1259 	return blob->read_buf;
1260 }
1261 
1262 const struct got_error *
1263 got_object_blob_read_block(size_t *outlenp, struct got_blob_object *blob)
1264 {
1265 	size_t n;
1266 
1267 	n = fread(blob->read_buf, 1, blob->blocksize, blob->f);
1268 	if (n == 0 && ferror(blob->f))
1269 		return got_ferror(blob->f, GOT_ERR_IO);
1270 	*outlenp = n;
1271 	return NULL;
1272 }
1273 
1274 const struct got_error *
1275 got_object_blob_dump_to_file(size_t *filesize, int *nlines,
1276     off_t **line_offsets, FILE *outfile, struct got_blob_object *blob)
1277 {
1278 	const struct got_error *err = NULL;
1279 	size_t n, len, hdrlen;
1280 	const uint8_t *buf;
1281 	int i;
1282 	size_t noffsets = 0;
1283 	off_t off = 0, total_len = 0;
1284 
1285 	if (line_offsets)
1286 		*line_offsets = NULL;
1287 	if (filesize)
1288 		*filesize = 0;
1289 	if (nlines)
1290 		*nlines = 0;
1291 
1292 	hdrlen = got_object_blob_get_hdrlen(blob);
1293 	do {
1294 		err = got_object_blob_read_block(&len, blob);
1295 		if (err)
1296 			return err;
1297 		if (len == 0)
1298 			break;
1299 		buf = got_object_blob_get_read_buf(blob);
1300 		i = hdrlen;
1301 		if (line_offsets && nlines) {
1302 			if (*line_offsets == NULL) {
1303 				/* Have some data but perhaps no '\n'. */
1304 				noffsets = 1;
1305 				*nlines = 1;
1306 				*line_offsets = calloc(1, sizeof(**line_offsets));
1307 				if (*line_offsets == NULL)
1308 					return got_error_from_errno("calloc");
1309 
1310 				/* Skip forward over end of first line. */
1311 				while (i < len) {
1312 					if (buf[i] == '\n')
1313 						break;
1314 					i++;
1315 				}
1316 			}
1317 			/* Scan '\n' offsets in remaining chunk of data. */
1318 			while (i < len) {
1319 				if (buf[i] != '\n') {
1320 					i++;
1321 					continue;
1322 				}
1323 				(*nlines)++;
1324 				if (noffsets < *nlines) {
1325 					off_t *o = recallocarray(*line_offsets,
1326 					    noffsets, *nlines,
1327 					    sizeof(**line_offsets));
1328 					if (o == NULL) {
1329 						free(*line_offsets);
1330 						*line_offsets = NULL;
1331 						return got_error_from_errno(
1332 						    "recallocarray");
1333 					}
1334 					*line_offsets = o;
1335 					noffsets = *nlines;
1336 				}
1337 				off = total_len + i - hdrlen + 1;
1338 				(*line_offsets)[*nlines - 1] = off;
1339 				i++;
1340 			}
1341 		}
1342 		/* Skip blob object header first time around. */
1343 		n = fwrite(buf + hdrlen, 1, len - hdrlen, outfile);
1344 		if (n != len - hdrlen)
1345 			return got_ferror(outfile, GOT_ERR_IO);
1346 		total_len += len - hdrlen;
1347 		hdrlen = 0;
1348 	} while (len != 0);
1349 
1350 	if (fflush(outfile) != 0)
1351 		return got_error_from_errno("fflush");
1352 	rewind(outfile);
1353 
1354 	if (filesize)
1355 		*filesize = total_len;
1356 
1357 	return NULL;
1358 }
1359 
1360 static const struct got_error *
1361 request_packed_tag(struct got_tag_object **tag, struct got_pack *pack,
1362     int pack_idx, struct got_object_id *id)
1363 {
1364 	const struct got_error *err = NULL;
1365 
1366 	err = got_privsep_send_tag_req(pack->privsep_child->ibuf, -1, id,
1367 	    pack_idx);
1368 	if (err)
1369 		return err;
1370 
1371 	return got_privsep_recv_tag(tag, pack->privsep_child->ibuf);
1372 }
1373 
1374 static const struct got_error *
1375 read_packed_tag_privsep(struct got_tag_object **tag,
1376     struct got_pack *pack, struct got_packidx *packidx, int idx,
1377     struct got_object_id *id)
1378 {
1379 	const struct got_error *err = NULL;
1380 
1381 	if (pack->privsep_child)
1382 		return request_packed_tag(tag, pack, idx, id);
1383 
1384 	err = start_pack_privsep_child(pack, packidx);
1385 	if (err)
1386 		return err;
1387 
1388 	return request_packed_tag(tag, pack, idx, id);
1389 }
1390 
1391 static const struct got_error *
1392 request_tag(struct got_tag_object **tag, struct got_repository *repo,
1393     int fd)
1394 {
1395 	const struct got_error *err = NULL;
1396 	struct imsgbuf *ibuf;
1397 
1398 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf;
1399 
1400 	err = got_privsep_send_tag_req(ibuf, fd, NULL, -1);
1401 	if (err)
1402 		return err;
1403 
1404 	return got_privsep_recv_tag(tag, ibuf);
1405 }
1406 
1407 static const struct got_error *
1408 read_tag_privsep(struct got_tag_object **tag, int obj_fd,
1409     struct got_repository *repo)
1410 {
1411 	const struct got_error *err;
1412 	int imsg_fds[2];
1413 	pid_t pid;
1414 	struct imsgbuf *ibuf;
1415 
1416 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd != -1)
1417 		return request_tag(tag, repo, obj_fd);
1418 
1419 	ibuf = calloc(1, sizeof(*ibuf));
1420 	if (ibuf == NULL)
1421 		return got_error_from_errno("calloc");
1422 
1423 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1424 		err = got_error_from_errno("socketpair");
1425 		free(ibuf);
1426 		return err;
1427 	}
1428 
1429 	pid = fork();
1430 	if (pid == -1) {
1431 		err = got_error_from_errno("fork");
1432 		free(ibuf);
1433 		return err;
1434 	}
1435 	else if (pid == 0) {
1436 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TAG,
1437 		    repo->path);
1438 		/* not reached */
1439 	}
1440 
1441 	if (close(imsg_fds[1]) != 0) {
1442 		err = got_error_from_errno("close");
1443 		free(ibuf);
1444 		return err;
1445 	}
1446 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd =
1447 	    imsg_fds[0];
1448 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].pid = pid;
1449 	imsg_init(ibuf, imsg_fds[0]);
1450 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf = ibuf;
1451 
1452 	return request_tag(tag, repo, obj_fd);
1453 }
1454 
1455 static const struct got_error *
1456 open_tag(struct got_tag_object **tag, struct got_repository *repo,
1457     struct got_object_id *id, int check_cache)
1458 {
1459 	const struct got_error *err = NULL;
1460 	struct got_packidx *packidx = NULL;
1461 	int idx;
1462 	char *path_packfile = NULL;
1463 	struct got_object *obj = NULL;
1464 	int obj_type = GOT_OBJ_TYPE_ANY;
1465 
1466 	if (check_cache) {
1467 		*tag = got_repo_get_cached_tag(repo, id);
1468 		if (*tag != NULL) {
1469 			(*tag)->refcnt++;
1470 			return NULL;
1471 		}
1472 	} else
1473 		*tag = NULL;
1474 
1475 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1476 	if (err == NULL) {
1477 		struct got_pack *pack = NULL;
1478 
1479 		err = get_packfile_path(&path_packfile, packidx);
1480 		if (err)
1481 			return err;
1482 
1483 		pack = got_repo_get_cached_pack(repo, path_packfile);
1484 		if (pack == NULL) {
1485 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1486 			    packidx);
1487 			if (err)
1488 				goto done;
1489 		}
1490 
1491 		/* Beware of "lightweight" tags: Check object type first. */
1492 		err = read_packed_object_privsep(&obj, repo, pack, packidx,
1493 		    idx, id);
1494 		if (err)
1495 			goto done;
1496 		obj_type = obj->type;
1497 		got_object_close(obj);
1498 		if (obj_type != GOT_OBJ_TYPE_TAG) {
1499 			err = got_error(GOT_ERR_OBJ_TYPE);
1500 			goto done;
1501 		}
1502 		err = read_packed_tag_privsep(tag, pack, packidx, idx, id);
1503 	} else if (err->code == GOT_ERR_NO_OBJ) {
1504 		int fd;
1505 
1506 		err = open_loose_object(&fd, id, repo);
1507 		if (err)
1508 			return err;
1509 		err = read_object_header_privsep(&obj, repo, fd);
1510 		if (err)
1511 			return err;
1512 		obj_type = obj->type;
1513 		got_object_close(obj);
1514 		if (obj_type != GOT_OBJ_TYPE_TAG)
1515 			return got_error(GOT_ERR_OBJ_TYPE);
1516 
1517 		err = open_loose_object(&fd, id, repo);
1518 		if (err)
1519 			return err;
1520 		err = read_tag_privsep(tag, fd, repo);
1521 	}
1522 
1523 	if (err == NULL) {
1524 		(*tag)->refcnt++;
1525 		err = got_repo_cache_tag(repo, id, *tag);
1526 	}
1527 done:
1528 	free(path_packfile);
1529 	return err;
1530 }
1531 
1532 const struct got_error *
1533 got_object_open_as_tag(struct got_tag_object **tag,
1534     struct got_repository *repo, struct got_object_id *id)
1535 {
1536 	*tag = got_repo_get_cached_tag(repo, id);
1537 	if (*tag != NULL) {
1538 		(*tag)->refcnt++;
1539 		return NULL;
1540 	}
1541 
1542 	return open_tag(tag, repo, id, 0);
1543 }
1544 
1545 const struct got_error *
1546 got_object_tag_open(struct got_tag_object **tag,
1547     struct got_repository *repo, struct got_object *obj)
1548 {
1549 	return open_tag(tag, repo, got_object_get_id(obj), 1);
1550 }
1551 
1552 const char *
1553 got_object_tag_get_name(struct got_tag_object *tag)
1554 {
1555 	return tag->tag;
1556 }
1557 
1558 int
1559 got_object_tag_get_object_type(struct got_tag_object *tag)
1560 {
1561 	return tag->obj_type;
1562 }
1563 
1564 struct got_object_id *
1565 got_object_tag_get_object_id(struct got_tag_object *tag)
1566 {
1567 	return &tag->id;
1568 }
1569 
1570 time_t
1571 got_object_tag_get_tagger_time(struct got_tag_object *tag)
1572 {
1573 	return tag->tagger_time;
1574 }
1575 
1576 time_t
1577 got_object_tag_get_tagger_gmtoff(struct got_tag_object *tag)
1578 {
1579 	return tag->tagger_gmtoff;
1580 }
1581 
1582 const char *
1583 got_object_tag_get_tagger(struct got_tag_object *tag)
1584 {
1585 	return tag->tagger;
1586 }
1587 
1588 const char *
1589 got_object_tag_get_message(struct got_tag_object *tag)
1590 {
1591 	return tag->tagmsg;
1592 }
1593 
1594 static struct got_tree_entry *
1595 find_entry_by_name(struct got_tree_object *tree, const char *name, size_t len)
1596 {
1597 	int i;
1598 
1599 	/* Note that tree entries are sorted in strncmp() order. */
1600 	for (i = 0; i < tree->nentries; i++) {
1601 		struct got_tree_entry *te = &tree->entries[i];
1602 		int cmp = strncmp(te->name, name, len);
1603 		if (cmp < 0)
1604 			continue;
1605 		if (cmp > 0)
1606 			break;
1607 		if (te->name[len] == '\0')
1608 			return te;
1609 	}
1610 	return NULL;
1611 }
1612 
1613 struct got_tree_entry *
1614 got_object_tree_find_entry(struct got_tree_object *tree, const char *name)
1615 {
1616 	return find_entry_by_name(tree, name, strlen(name));
1617 }
1618 
1619 const struct got_error *
1620 got_object_id_by_path(struct got_object_id **id, struct got_repository *repo,
1621     struct got_object_id *commit_id, const char *path)
1622 {
1623 	const struct got_error *err = NULL;
1624 	struct got_commit_object *commit = NULL;
1625 	struct got_tree_object *tree = NULL;
1626 	struct got_tree_entry *te = NULL;
1627 	const char *seg, *s;
1628 	size_t seglen;
1629 
1630 	*id = NULL;
1631 
1632 	err = got_object_open_as_commit(&commit, repo, commit_id);
1633 	if (err)
1634 		goto done;
1635 
1636 	/* Handle opening of root of commit's tree. */
1637 	if (got_path_is_root_dir(path)) {
1638 		*id = got_object_id_dup(commit->tree_id);
1639 		if (*id == NULL)
1640 			err = got_error_from_errno("got_object_id_dup");
1641 		goto done;
1642 	}
1643 
1644 	err = got_object_open_as_tree(&tree, repo, commit->tree_id);
1645 	if (err)
1646 		goto done;
1647 
1648 	s = path;
1649 	while (s[0] == '/')
1650 		s++;
1651 	seg = s;
1652 	seglen = 0;
1653 	while (*s) {
1654 		struct got_tree_object *next_tree;
1655 
1656 		if (*s != '/') {
1657 			s++;
1658 			seglen++;
1659 			if (*s)
1660 				continue;
1661 		}
1662 
1663 		te = find_entry_by_name(tree, seg, seglen);
1664 		if (te == NULL) {
1665 			err = got_error(GOT_ERR_NO_TREE_ENTRY);
1666 			goto done;
1667 		}
1668 
1669 		if (*s == '\0')
1670 			break;
1671 
1672 		seg = s + 1;
1673 		seglen = 0;
1674 		s++;
1675 		if (*s) {
1676 			err = got_object_open_as_tree(&next_tree, repo,
1677 			    &te->id);
1678 			te = NULL;
1679 			if (err)
1680 				goto done;
1681 			got_object_tree_close(tree);
1682 			tree = next_tree;
1683 		}
1684 	}
1685 
1686 	if (te) {
1687 		*id = got_object_id_dup(&te->id);
1688 		if (*id == NULL)
1689 			return got_error_from_errno("got_object_id_dup");
1690 	} else
1691 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
1692 done:
1693 	if (commit)
1694 		got_object_commit_close(commit);
1695 	if (tree)
1696 		got_object_tree_close(tree);
1697 	return err;
1698 }
1699 
1700 /*
1701  * Normalize file mode bits to avoid false positive tree entry differences
1702  * in case tree entries have unexpected mode bits set.
1703  */
1704 static mode_t
1705 normalize_mode_for_comparison(mode_t mode)
1706 {
1707 	/*
1708 	 * For directories, the only relevant bit is the IFDIR bit.
1709 	 * This allows us to detect paths changing from a directory
1710 	 * to a file and vice versa.
1711 	 */
1712 	if (S_ISDIR(mode))
1713 		return mode & S_IFDIR;
1714 
1715 	/*
1716 	 * For symlinks, the only relevant bit is the IFLNK bit.
1717 	 * This allows us to detect paths changing from a symlinks
1718 	 * to a file or directory and vice versa.
1719 	 */
1720 	if (S_ISLNK(mode))
1721 		return mode & S_IFLNK;
1722 
1723 	/* For files, the only change we care about is the executable bit. */
1724 	return mode & S_IXUSR;
1725 }
1726 
1727 const struct got_error *
1728 got_object_tree_path_changed(int *changed,
1729     struct got_tree_object *tree01, struct got_tree_object *tree02,
1730     const char *path, struct got_repository *repo)
1731 {
1732 	const struct got_error *err = NULL;
1733 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
1734 	struct got_tree_entry *te1 = NULL, *te2 = NULL;
1735 	const char *seg, *s;
1736 	size_t seglen;
1737 
1738 	*changed = 0;
1739 
1740 	/* We not do support comparing the root path. */
1741 	if (got_path_is_root_dir(path))
1742 		return got_error_path(path, GOT_ERR_BAD_PATH);
1743 
1744 	tree1 = tree01;
1745 	tree2 = tree02;
1746 	s = path;
1747 	while (*s == '/')
1748 		s++;
1749 	seg = s;
1750 	seglen = 0;
1751 	while (*s) {
1752 		struct got_tree_object *next_tree1, *next_tree2;
1753 		mode_t mode1, mode2;
1754 
1755 		if (*s != '/') {
1756 			s++;
1757 			seglen++;
1758 			if (*s)
1759 				continue;
1760 		}
1761 
1762 		te1 = find_entry_by_name(tree1, seg, seglen);
1763 		if (te1 == NULL) {
1764 			err = got_error(GOT_ERR_NO_OBJ);
1765 			goto done;
1766 		}
1767 
1768 		te2 = find_entry_by_name(tree2, seg, seglen);
1769 		if (te2 == NULL) {
1770 			*changed = 1;
1771 			goto done;
1772 		}
1773 
1774 		mode1 = normalize_mode_for_comparison(te1->mode);
1775 		mode2 = normalize_mode_for_comparison(te2->mode);
1776 		if (mode1 != mode2) {
1777 			*changed = 1;
1778 			goto done;
1779 		}
1780 
1781 		if (got_object_id_cmp(&te1->id, &te2->id) == 0) {
1782 			*changed = 0;
1783 			goto done;
1784 		}
1785 
1786 		if (*s == '\0') { /* final path element */
1787 			*changed = 1;
1788 			goto done;
1789 		}
1790 
1791 		seg = s + 1;
1792 		s++;
1793 		seglen = 0;
1794 		if (*s) {
1795 			err = got_object_open_as_tree(&next_tree1, repo,
1796 			    &te1->id);
1797 			te1 = NULL;
1798 			if (err)
1799 				goto done;
1800 			if (tree1 != tree01)
1801 				got_object_tree_close(tree1);
1802 			tree1 = next_tree1;
1803 
1804 			err = got_object_open_as_tree(&next_tree2, repo,
1805 			    &te2->id);
1806 			te2 = NULL;
1807 			if (err)
1808 				goto done;
1809 			if (tree2 != tree02)
1810 				got_object_tree_close(tree2);
1811 			tree2 = next_tree2;
1812 		}
1813 	}
1814 done:
1815 	if (tree1 && tree1 != tree01)
1816 		got_object_tree_close(tree1);
1817 	if (tree2 && tree2 != tree02)
1818 		got_object_tree_close(tree2);
1819 	return err;
1820 }
1821 
1822 const struct got_error *
1823 got_object_tree_entry_dup(struct got_tree_entry **new_te,
1824     struct got_tree_entry *te)
1825 {
1826 	const struct got_error *err = NULL;
1827 
1828 	*new_te = calloc(1, sizeof(**new_te));
1829 	if (*new_te == NULL)
1830 		return got_error_from_errno("calloc");
1831 
1832 	(*new_te)->mode = te->mode;
1833 	memcpy((*new_te)->name, te->name, sizeof((*new_te)->name));
1834 	memcpy(&(*new_te)->id, &te->id, sizeof((*new_te)->id));
1835 	return err;
1836 }
1837 
1838 int
1839 got_object_tree_entry_is_submodule(struct got_tree_entry *te)
1840 {
1841 	return (te->mode & S_IFMT) == (S_IFDIR | S_IFLNK);
1842 }
1843 
1844 int
1845 got_object_tree_entry_is_symlink(struct got_tree_entry *te)
1846 {
1847 	/* S_IFDIR check avoids confusing symlinks with submodules. */
1848 	return ((te->mode & (S_IFDIR | S_IFLNK)) == S_IFLNK);
1849 }
1850 
1851 static const struct got_error *
1852 resolve_symlink(char **link_target, const char *path,
1853     struct got_object_id *commit_id, struct got_repository *repo)
1854 {
1855 	const struct got_error *err = NULL;
1856 	char *name, *parent_path = NULL;
1857 	struct got_object_id *tree_obj_id = NULL;
1858 	struct got_tree_object *tree = NULL;
1859 	struct got_tree_entry *te = NULL;
1860 
1861 	*link_target = NULL;
1862 	
1863 	name = basename(path);
1864 	if (name == NULL)
1865 		return got_error_from_errno2("basename", path);
1866 
1867 	err = got_path_dirname(&parent_path, path);
1868 	if (err)
1869 		return err;
1870 
1871 	err = got_object_id_by_path(&tree_obj_id, repo, commit_id,
1872 	    parent_path);
1873 	if (err) {
1874 		if (err->code == GOT_ERR_NO_TREE_ENTRY) {
1875 			/* Display the complete path in error message. */
1876 			err = got_error_path(path, err->code);
1877 		}
1878 		goto done;
1879 	}
1880 
1881 	err = got_object_open_as_tree(&tree, repo, tree_obj_id);
1882 	if (err)
1883 		goto done;
1884 
1885 	te = got_object_tree_find_entry(tree, name);
1886 	if (te == NULL) {
1887 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
1888 		goto done;
1889 	}
1890 
1891 	if (got_object_tree_entry_is_symlink(te)) {
1892 		err = got_tree_entry_get_symlink_target(link_target, te, repo);
1893 		if (err)
1894 			goto done;
1895 		if (!got_path_is_absolute(*link_target)) {
1896 			char *abspath;
1897 			if (asprintf(&abspath, "%s/%s", parent_path,
1898 			    *link_target) == -1) {
1899 				err = got_error_from_errno("asprintf");
1900 				goto done;
1901 			}
1902 			free(*link_target);
1903 			*link_target = malloc(PATH_MAX);
1904 			if (*link_target == NULL) {
1905 				err = got_error_from_errno("malloc");
1906 				goto done;
1907 			}
1908 			err = got_canonpath(abspath, *link_target, PATH_MAX);
1909 			free(abspath);
1910 			if (err)
1911 				goto done;
1912 		}
1913 	}
1914 done:
1915 	free(tree_obj_id);
1916 	if (tree)
1917 		got_object_tree_close(tree);
1918 	if (err) {
1919 		free(*link_target);
1920 		*link_target = NULL;
1921 	}
1922 	return err;
1923 }
1924 
1925 const struct got_error *
1926 got_object_resolve_symlinks(char **link_target, const char *path,
1927     struct got_object_id *commit_id, struct got_repository *repo)
1928 {
1929 	const struct got_error *err = NULL;
1930 	char *next_target = NULL;
1931 	int max_recursion = 40; /* matches Git */
1932 
1933 	*link_target = NULL;
1934 
1935 	do {
1936 		err = resolve_symlink(&next_target,
1937 		    *link_target ? *link_target : path, commit_id, repo);
1938 		if (err)
1939 			break;
1940 		if (next_target) {
1941 			free(*link_target);
1942 			if (--max_recursion == 0) {
1943 				err = got_error_path(path, GOT_ERR_RECURSION);
1944 				*link_target = NULL;
1945 				break;
1946 			}
1947 			*link_target = next_target;
1948 		}
1949 	} while (next_target);
1950 
1951 	return err;
1952 }
1953 
1954 const struct got_error *
1955 got_traverse_packed_commits(struct got_object_id_queue *traversed_commits,
1956     struct got_object_id *commit_id, const char *path,
1957     struct got_repository *repo)
1958 {
1959 	const struct got_error *err = NULL;
1960 	struct got_pack *pack = NULL;
1961 	struct got_packidx *packidx = NULL;
1962 	char *path_packfile = NULL;
1963 	struct got_commit_object *changed_commit = NULL;
1964 	struct got_object_id *changed_commit_id = NULL;
1965 	int idx;
1966 
1967 	err = got_repo_search_packidx(&packidx, &idx, repo, commit_id);
1968 	if (err) {
1969 		if (err->code != GOT_ERR_NO_OBJ)
1970 			return err;
1971 		return NULL;
1972 	}
1973 
1974 	err = get_packfile_path(&path_packfile, packidx);
1975 	if (err)
1976 		return err;
1977 
1978 	pack = got_repo_get_cached_pack(repo, path_packfile);
1979 	if (pack == NULL) {
1980 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
1981 		if (err)
1982 			goto done;
1983 	}
1984 
1985 	if (pack->privsep_child == NULL) {
1986 		err = start_pack_privsep_child(pack, packidx);
1987 		if (err)
1988 			goto done;
1989 	}
1990 
1991 	err = got_privsep_send_commit_traversal_request(
1992 	    pack->privsep_child->ibuf, commit_id, idx, path);
1993 	if (err)
1994 		goto done;
1995 
1996 	err = got_privsep_recv_traversed_commits(&changed_commit,
1997 	    &changed_commit_id, traversed_commits, pack->privsep_child->ibuf);
1998 	if (err)
1999 		goto done;
2000 
2001 	if (changed_commit) {
2002 		/*
2003 		 * Cache the commit in which the path was changed.
2004 		 * This commit might be opened again soon.
2005 		 */
2006 		changed_commit->refcnt++;
2007 		err = got_repo_cache_commit(repo, changed_commit_id,
2008 		    changed_commit);
2009 		got_object_commit_close(changed_commit);
2010 	}
2011 done:
2012 	free(path_packfile);
2013 	free(changed_commit_id);
2014 	return err;
2015 }