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Date:: Wed Oct 13 11:09:15 2021 UTC
Message:: use RB_TREE instead of STAILQ to manage packindex bloom filters; much faster
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/tree.h>
21 #include <sys/uio.h>
22 #include <sys/socket.h>
23 #include <sys/wait.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 <unistd.h>
34 #include <zlib.h>
35 #include <ctype.h>
36 #include <libgen.h>
37 #include <limits.h>
38 #include <imsg.h>
39 #include <time.h>
40 
41 #include "got_error.h"
42 #include "got_object.h"
43 #include "got_repository.h"
44 #include "got_opentemp.h"
45 #include "got_path.h"
46 
47 #include "got_lib_sha1.h"
48 #include "got_lib_delta.h"
49 #include "got_lib_inflate.h"
50 #include "got_lib_object.h"
51 #include "got_lib_privsep.h"
52 #include "got_lib_object_idcache.h"
53 #include "got_lib_object_cache.h"
54 #include "got_lib_object_parse.h"
55 #include "got_lib_pack.h"
56 #include "got_lib_repository.h"
57 
58 #ifndef MIN
59 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
60 #endif
61 
62 struct got_object_id *
63 got_object_get_id(struct got_object *obj)
64 {
65 	return &obj->id;
66 }
67 
68 const struct got_error *
69 got_object_get_id_str(char **outbuf, struct got_object *obj)
70 {
71 	return got_object_id_str(outbuf, &obj->id);
72 }
73 
74 const struct got_error *
75 got_object_get_type(int *type, struct got_repository *repo,
76     struct got_object_id *id)
77 {
78 	const struct got_error *err = NULL;
79 	struct got_object *obj;
80 
81 	err = got_object_open(&obj, repo, id);
82 	if (err)
83 		return err;
84 
85 	switch (obj->type) {
86 	case GOT_OBJ_TYPE_COMMIT:
87 	case GOT_OBJ_TYPE_TREE:
88 	case GOT_OBJ_TYPE_BLOB:
89 	case GOT_OBJ_TYPE_TAG:
90 		*type = obj->type;
91 		break;
92 	default:
93 		err = got_error(GOT_ERR_OBJ_TYPE);
94 		break;
95 	}
96 
97 	got_object_close(obj);
98 	return err;
99 }
100 
101 const struct got_error *
102 got_object_get_path(char **path, struct got_object_id *id,
103     struct got_repository *repo)
104 {
105 	const struct got_error *err = NULL;
106 	char *hex = NULL;
107 	char *path_objects;
108 
109 	*path = NULL;
110 
111 	path_objects = got_repo_get_path_objects(repo);
112 	if (path_objects == NULL)
113 		return got_error_from_errno("got_repo_get_path_objects");
114 
115 	err = got_object_id_str(&hex, id);
116 	if (err)
117 		goto done;
118 
119 	if (asprintf(path, "%s/%.2x/%s", path_objects,
120 	    id->sha1[0], hex + 2) == -1)
121 		err = got_error_from_errno("asprintf");
122 
123 done:
124 	free(hex);
125 	free(path_objects);
126 	return err;
127 }
128 
129 const struct got_error *
130 got_object_open_loose_fd(int *fd, struct got_object_id *id,
131     struct got_repository *repo)
132 {
133 	const struct got_error *err = NULL;
134 	char *path;
135 
136 	err = got_object_get_path(&path, id, repo);
137 	if (err)
138 		return err;
139 	*fd = open(path, O_RDONLY | O_NOFOLLOW);
140 	if (*fd == -1) {
141 		err = got_error_from_errno2("open", path);
142 		goto done;
143 	}
144 done:
145 	free(path);
146 	return err;
147 }
148 
149 static const struct got_error *
150 request_packed_object(struct got_object **obj, struct got_pack *pack, int idx,
151     struct got_object_id *id)
152 {
153 	const struct got_error *err = NULL;
154 	struct imsgbuf *ibuf = pack->privsep_child->ibuf;
155 
156 	err = got_privsep_send_packed_obj_req(ibuf, idx, id);
157 	if (err)
158 		return err;
159 
160 	err = got_privsep_recv_obj(obj, ibuf);
161 	if (err)
162 		return err;
163 
164 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
165 
166 	return NULL;
167 }
168 
169 static const struct got_error *
170 request_packed_object_raw(uint8_t **outbuf, off_t *size, size_t *hdrlen,
171     int outfd, struct got_pack *pack, int idx, struct got_object_id *id)
172 {
173 	const struct got_error *err = NULL;
174 	struct imsgbuf *ibuf = pack->privsep_child->ibuf;
175 	int outfd_child;
176 	int basefd, accumfd; /* temporary files for delta application */
177 
178 	basefd = got_opentempfd();
179 	if (basefd == -1)
180 		return got_error_from_errno("got_opentempfd");
181 
182 	accumfd = got_opentempfd();
183 	if (accumfd == -1) {
184 		close(basefd);
185 		return got_error_from_errno("got_opentempfd");
186 	}
187 
188 	outfd_child = dup(outfd);
189 	if (outfd_child == -1) {
190 		err = got_error_from_errno("dup");
191 		close(basefd);
192 		close(accumfd);
193 		return err;
194 	}
195 
196 	err = got_privsep_send_packed_raw_obj_req(ibuf, idx, id);
197 	if (err) {
198 		close(basefd);
199 		close(accumfd);
200 		close(outfd_child);
201 		return err;
202 	}
203 
204 	err = got_privsep_send_raw_obj_outfd(ibuf, outfd_child);
205 	if (err) {
206 		close(basefd);
207 		close(accumfd);
208 		return err;
209 	}
210 
211 
212 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
213 	    basefd);
214 	if (err) {
215 		close(accumfd);
216 		return err;
217 	}
218 
219 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
220 	    accumfd);
221 	if (err)
222 		return err;
223 
224 	err = got_privsep_recv_raw_obj(outbuf, size, hdrlen, ibuf);
225 	if (err)
226 		return err;
227 
228 	return NULL;
229 }
230 
231 static void
232 set_max_datasize(void)
233 {
234 	struct rlimit rl;
235 
236 	if (getrlimit(RLIMIT_DATA, &rl) != 0)
237 		return;
238 
239 	rl.rlim_cur = rl.rlim_max;
240 	setrlimit(RLIMIT_DATA, &rl);
241 }
242 
243 static const struct got_error *
244 start_pack_privsep_child(struct got_pack *pack, struct got_packidx *packidx)
245 {
246 	const struct got_error *err = NULL;
247 	int imsg_fds[2];
248 	pid_t pid;
249 	struct imsgbuf *ibuf;
250 
251 	ibuf = calloc(1, sizeof(*ibuf));
252 	if (ibuf == NULL)
253 		return got_error_from_errno("calloc");
254 
255 	pack->privsep_child = calloc(1, sizeof(*pack->privsep_child));
256 	if (pack->privsep_child == NULL) {
257 		err = got_error_from_errno("calloc");
258 		free(ibuf);
259 		return err;
260 	}
261 
262 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
263 		err = got_error_from_errno("socketpair");
264 		goto done;
265 	}
266 
267 	pid = fork();
268 	if (pid == -1) {
269 		err = got_error_from_errno("fork");
270 		goto done;
271 	} else if (pid == 0) {
272 		set_max_datasize();
273 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PACK,
274 		    pack->path_packfile);
275 		/* not reached */
276 	}
277 
278 	if (close(imsg_fds[1]) == -1)
279 		return got_error_from_errno("close");
280 	pack->privsep_child->imsg_fd = imsg_fds[0];
281 	pack->privsep_child->pid = pid;
282 	imsg_init(ibuf, imsg_fds[0]);
283 	pack->privsep_child->ibuf = ibuf;
284 
285 	err = got_privsep_init_pack_child(ibuf, pack, packidx);
286 	if (err) {
287 		const struct got_error *child_err;
288 		err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
289 		child_err = got_privsep_wait_for_child(
290 		    pack->privsep_child->pid);
291 		if (child_err && err == NULL)
292 			err = child_err;
293 	}
294 done:
295 	if (err) {
296 		free(ibuf);
297 		free(pack->privsep_child);
298 		pack->privsep_child = NULL;
299 	}
300 	return err;
301 }
302 
303 static const struct got_error *
304 read_packed_object_privsep(struct got_object **obj,
305     struct got_repository *repo, struct got_pack *pack,
306     struct got_packidx *packidx, int idx, struct got_object_id *id)
307 {
308 	const struct got_error *err = NULL;
309 
310 	if (pack->privsep_child == NULL) {
311 		err = start_pack_privsep_child(pack, packidx);
312 		if (err)
313 			return err;
314 	}
315 
316 	return request_packed_object(obj, pack, idx, id);
317 }
318 
319 static const struct got_error *
320 read_packed_object_raw_privsep(uint8_t **outbuf, off_t *size, size_t *hdrlen,
321     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
322     struct got_object_id *id)
323 {
324 	const struct got_error *err = NULL;
325 
326 	if (pack->privsep_child == NULL) {
327 		err = start_pack_privsep_child(pack, packidx);
328 		if (err)
329 			return err;
330 	}
331 
332 	return request_packed_object_raw(outbuf, size, hdrlen, outfd, pack,
333 	    idx, id);
334 }
335 
336 const struct got_error *
337 got_object_open_packed(struct got_object **obj, struct got_object_id *id,
338     struct got_repository *repo)
339 {
340 	const struct got_error *err = NULL;
341 	struct got_pack *pack = NULL;
342 	struct got_packidx *packidx = NULL;
343 	int idx;
344 	char *path_packfile;
345 
346 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
347 	if (err)
348 		return err;
349 
350 	err = got_packidx_get_packfile_path(&path_packfile,
351 	    packidx->path_packidx);
352 	if (err)
353 		return err;
354 
355 	pack = got_repo_get_cached_pack(repo, path_packfile);
356 	if (pack == NULL) {
357 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
358 		if (err)
359 			goto done;
360 	}
361 
362 	err = read_packed_object_privsep(obj, repo, pack, packidx, idx, id);
363 	if (err)
364 		goto done;
365 done:
366 	free(path_packfile);
367 	return err;
368 }
369 
370 static const struct got_error *
371 request_object(struct got_object **obj, struct got_object_id *id,
372     struct got_repository *repo, int fd)
373 {
374 	const struct got_error *err = NULL;
375 	struct imsgbuf *ibuf;
376 
377 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf;
378 
379 	err = got_privsep_send_obj_req(ibuf, fd, id);
380 	if (err)
381 		return err;
382 
383 	return got_privsep_recv_obj(obj, ibuf);
384 }
385 
386 static const struct got_error *
387 request_raw_object(uint8_t **outbuf, off_t *size, size_t *hdrlen, int outfd,
388     struct got_object_id *id, struct got_repository *repo, int infd)
389 {
390 	const struct got_error *err = NULL;
391 	struct imsgbuf *ibuf;
392 	int outfd_child;
393 
394 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf;
395 
396 	outfd_child = dup(outfd);
397 	if (outfd_child == -1)
398 		return got_error_from_errno("dup");
399 
400 	err = got_privsep_send_raw_obj_req(ibuf, infd, id);
401 	if (err)
402 		return err;
403 
404 	err = got_privsep_send_raw_obj_outfd(ibuf, outfd_child);
405 	if (err)
406 		return err;
407 
408 	return got_privsep_recv_raw_obj(outbuf, size, hdrlen, ibuf);
409 }
410 
411 static const struct got_error *
412 start_read_object_child(struct got_repository *repo)
413 {
414 	const struct got_error *err = NULL;
415 	int imsg_fds[2];
416 	pid_t pid;
417 	struct imsgbuf *ibuf;
418 
419 	ibuf = calloc(1, sizeof(*ibuf));
420 	if (ibuf == NULL)
421 		return got_error_from_errno("calloc");
422 
423 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
424 		err = got_error_from_errno("socketpair");
425 		free(ibuf);
426 		return err;
427 	}
428 
429 	pid = fork();
430 	if (pid == -1) {
431 		err = got_error_from_errno("fork");
432 		free(ibuf);
433 		return err;
434 	}
435 	else if (pid == 0) {
436 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_OBJECT,
437 		    repo->path);
438 		/* not reached */
439 	}
440 
441 	if (close(imsg_fds[1]) == -1) {
442 		err = got_error_from_errno("close");
443 		free(ibuf);
444 		return err;
445 	}
446 
447 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd =
448 	    imsg_fds[0];
449 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].pid = pid;
450 	imsg_init(ibuf, imsg_fds[0]);
451 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf = ibuf;
452 
453 	return NULL;
454 }
455 
456 const struct got_error *
457 got_object_read_header_privsep(struct got_object **obj,
458     struct got_object_id *id, struct got_repository *repo, int obj_fd)
459 {
460 	const struct got_error *err;
461 
462 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd != -1)
463 		return request_object(obj, id, repo, obj_fd);
464 
465 	err = start_read_object_child(repo);
466 	if (err) {
467 		close(obj_fd);
468 		return err;
469 	}
470 
471 	return request_object(obj, id, repo, obj_fd);
472 }
473 
474 static const struct got_error *
475 read_object_raw_privsep(uint8_t **outbuf, off_t *size, size_t *hdrlen,
476     int outfd, struct got_object_id *id, struct got_repository *repo,
477     int obj_fd)
478 {
479 	const struct got_error *err;
480 
481 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd != -1)
482 		return request_raw_object(outbuf, size, hdrlen, outfd, id,
483 		    repo, obj_fd);
484 
485 	err = start_read_object_child(repo);
486 	if (err)
487 		return err;
488 
489 	return request_raw_object(outbuf, size, hdrlen, outfd, id, repo,
490 	    obj_fd);
491 }
492 
493 const struct got_error *
494 got_object_open(struct got_object **obj, struct got_repository *repo,
495     struct got_object_id *id)
496 {
497 	const struct got_error *err = NULL;
498 	int fd;
499 
500 	*obj = got_repo_get_cached_object(repo, id);
501 	if (*obj != NULL) {
502 		(*obj)->refcnt++;
503 		return NULL;
504 	}
505 
506 	err = got_object_open_packed(obj, id, repo);
507 	if (err && err->code != GOT_ERR_NO_OBJ)
508 		return err;
509 	if (*obj) {
510 		(*obj)->refcnt++;
511 		return got_repo_cache_object(repo, id, *obj);
512 	}
513 
514 	err = got_object_open_loose_fd(&fd, id, repo);
515 	if (err) {
516 		if (err->code == GOT_ERR_ERRNO && errno == ENOENT)
517 			err = got_error_no_obj(id);
518 		return err;
519 	}
520 
521 	err = got_object_read_header_privsep(obj, id, repo, fd);
522 	if (err)
523 		return err;
524 
525 	memcpy((*obj)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
526 
527 	(*obj)->refcnt++;
528 	return got_repo_cache_object(repo, id, *obj);
529 }
530 
531 const struct got_error *
532 got_object_raw_open(struct got_raw_object **obj, struct got_repository *repo,
533     struct got_object_id *id, size_t blocksize)
534 {
535 	const struct got_error *err = NULL;
536 	struct got_packidx *packidx = NULL;
537 	int idx;
538 	uint8_t *outbuf = NULL;
539 	int outfd = -1;
540 	off_t size = 0;
541 	size_t hdrlen = 0;
542 	char *path_packfile = NULL;
543 
544 	*obj = NULL;
545 
546 	outfd = got_opentempfd();
547 	if (outfd == -1)
548 		return got_error_from_errno("got_opentempfd");
549 
550 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
551 	if (err == NULL) {
552 		struct got_pack *pack = NULL;
553 
554 		err = got_packidx_get_packfile_path(&path_packfile,
555 		    packidx->path_packidx);
556 		if (err)
557 			goto done;
558 
559 		pack = got_repo_get_cached_pack(repo, path_packfile);
560 		if (pack == NULL) {
561 			err = got_repo_cache_pack(&pack, repo, path_packfile,
562 			    packidx);
563 			if (err)
564 				goto done;
565 		}
566 		err = read_packed_object_raw_privsep(&outbuf, &size, &hdrlen,
567 		    outfd, pack, packidx, idx, id);
568 	} else if (err->code == GOT_ERR_NO_OBJ) {
569 		int fd;
570 
571 		err = got_object_open_loose_fd(&fd, id, repo);
572 		if (err)
573 			goto done;
574 		err = read_object_raw_privsep(&outbuf, &size, &hdrlen, outfd,
575 		    id, repo, fd);
576 	}
577 
578 	*obj = calloc(1, sizeof(**obj));
579 	if (*obj == NULL) {
580 		err = got_error_from_errno("calloc");
581 		goto done;
582 	}
583 
584 	(*obj)->read_buf = malloc(blocksize);
585 	if ((*obj)->read_buf == NULL) {
586 		err = got_error_from_errno("malloc");
587 		goto done;
588 	}
589 
590 	if (outbuf) {
591 		if (close(outfd) == -1) {
592 			err = got_error_from_errno("close");
593 			goto done;
594 		}
595 		outfd = -1;
596 		(*obj)->f = fmemopen(outbuf, hdrlen + size, "r");
597 		if ((*obj)->f == NULL) {
598 			err = got_error_from_errno("fdopen");
599 			goto done;
600 		}
601 		(*obj)->data = outbuf;
602 	} else {
603 		struct stat sb;
604 		if (fstat(outfd, &sb) == -1) {
605 			err = got_error_from_errno("fstat");
606 			goto done;
607 		}
608 
609 		if (sb.st_size != hdrlen + size) {
610 			err = got_error(GOT_ERR_PRIVSEP_LEN);
611 			goto done;
612 		}
613 
614 		(*obj)->f = fdopen(outfd, "r");
615 		if ((*obj)->f == NULL) {
616 			err = got_error_from_errno("fdopen");
617 			goto done;
618 		}
619 		outfd = -1;
620 		(*obj)->data = NULL;
621 	}
622 	(*obj)->hdrlen = hdrlen;
623 	(*obj)->size = size;
624 	(*obj)->blocksize = blocksize;
625 done:
626 	free(path_packfile);
627 	if (err) {
628 		if (*obj) {
629 			got_object_raw_close(*obj);
630 			*obj = NULL;
631 		}
632 		if (outfd != -1)
633 			close(outfd);
634 		free(outbuf);
635 	}
636 	return err;
637 }
638 
639 void
640 got_object_raw_rewind(struct got_raw_object *obj)
641 {
642 	if (obj->f)
643 		rewind(obj->f);
644 }
645 
646 size_t
647 got_object_raw_get_hdrlen(struct got_raw_object *obj)
648 {
649 	return obj->hdrlen;
650 }
651 
652 const uint8_t *
653 got_object_raw_get_read_buf(struct got_raw_object *obj)
654 {
655 	return obj->read_buf;
656 }
657 
658 const struct got_error *
659 got_object_raw_read_block(size_t *outlenp, struct got_raw_object *obj)
660 {
661 	size_t n;
662 
663 	n = fread(obj->read_buf, 1, obj->blocksize, obj->f);
664 	if (n == 0 && ferror(obj->f))
665 		return got_ferror(obj->f, GOT_ERR_IO);
666 	*outlenp = n;
667 	return NULL;
668 }
669 
670 const struct got_error *
671 got_object_raw_close(struct got_raw_object *obj)
672 {
673 	const struct got_error *err = NULL;
674 
675 	free(obj->read_buf);
676 	if (obj->f != NULL && fclose(obj->f) == EOF && err == NULL)
677 		err = got_error_from_errno("fclose");
678 	free(obj->data);
679 	free(obj);
680 	return err;
681 }
682 
683 const struct got_error *
684 got_object_open_by_id_str(struct got_object **obj, struct got_repository *repo,
685     const char *id_str)
686 {
687 	struct got_object_id id;
688 
689 	if (!got_parse_sha1_digest(id.sha1, id_str))
690 		return got_error_path(id_str, GOT_ERR_BAD_OBJ_ID_STR);
691 
692 	return got_object_open(obj, repo, &id);
693 }
694 
695 const struct got_error *
696 got_object_resolve_id_str(struct got_object_id **id,
697     struct got_repository *repo, const char *id_str)
698 {
699 	const struct got_error *err = NULL;
700 	struct got_object *obj;
701 
702 	err = got_object_open_by_id_str(&obj, repo, id_str);
703 	if (err)
704 		return err;
705 
706 	*id = got_object_id_dup(got_object_get_id(obj));
707 	got_object_close(obj);
708 	if (*id == NULL)
709 		return got_error_from_errno("got_object_id_dup");
710 
711 	return NULL;
712 }
713 
714 static const struct got_error *
715 request_packed_commit(struct got_commit_object **commit, struct got_pack *pack,
716     int pack_idx, struct got_object_id *id)
717 {
718 	const struct got_error *err = NULL;
719 
720 	err = got_privsep_send_commit_req(pack->privsep_child->ibuf, -1, id,
721 	    pack_idx);
722 	if (err)
723 		return err;
724 
725 	err = got_privsep_recv_commit(commit, pack->privsep_child->ibuf);
726 	if (err)
727 		return err;
728 
729 	(*commit)->flags |= GOT_COMMIT_FLAG_PACKED;
730 	return NULL;
731 }
732 
733 static const struct got_error *
734 read_packed_commit_privsep(struct got_commit_object **commit,
735     struct got_pack *pack, struct got_packidx *packidx, int idx,
736     struct got_object_id *id)
737 {
738 	const struct got_error *err = NULL;
739 
740 	if (pack->privsep_child)
741 		return request_packed_commit(commit, pack, idx, id);
742 
743 	err = start_pack_privsep_child(pack, packidx);
744 	if (err)
745 		return err;
746 
747 	return request_packed_commit(commit, pack, idx, id);
748 }
749 
750 static const struct got_error *
751 request_commit(struct got_commit_object **commit, struct got_repository *repo,
752     int fd, struct got_object_id *id)
753 {
754 	const struct got_error *err = NULL;
755 	struct imsgbuf *ibuf;
756 
757 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf;
758 
759 	err = got_privsep_send_commit_req(ibuf, fd, id, -1);
760 	if (err)
761 		return err;
762 
763 	return got_privsep_recv_commit(commit, ibuf);
764 }
765 
766 static const struct got_error *
767 read_commit_privsep(struct got_commit_object **commit, int obj_fd,
768     struct got_object_id *id, struct got_repository *repo)
769 {
770 	const struct got_error *err;
771 	int imsg_fds[2];
772 	pid_t pid;
773 	struct imsgbuf *ibuf;
774 
775 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd != -1)
776 		return request_commit(commit, repo, obj_fd, id);
777 
778 	ibuf = calloc(1, sizeof(*ibuf));
779 	if (ibuf == NULL)
780 		return got_error_from_errno("calloc");
781 
782 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
783 		err = got_error_from_errno("socketpair");
784 		free(ibuf);
785 		return err;
786 	}
787 
788 	pid = fork();
789 	if (pid == -1) {
790 		err = got_error_from_errno("fork");
791 		free(ibuf);
792 		return err;
793 	}
794 	else if (pid == 0) {
795 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_COMMIT,
796 		    repo->path);
797 		/* not reached */
798 	}
799 
800 	if (close(imsg_fds[1]) == -1) {
801 		err = got_error_from_errno("close");
802 		free(ibuf);
803 		return err;
804 	}
805 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd =
806 	    imsg_fds[0];
807 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].pid = pid;
808 	imsg_init(ibuf, imsg_fds[0]);
809 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf = ibuf;
810 
811 	return request_commit(commit, repo, obj_fd, id);
812 }
813 
814 
815 static const struct got_error *
816 open_commit(struct got_commit_object **commit,
817     struct got_repository *repo, struct got_object_id *id, int check_cache)
818 {
819 	const struct got_error *err = NULL;
820 	struct got_packidx *packidx = NULL;
821 	int idx;
822 	char *path_packfile = NULL;
823 
824 	if (check_cache) {
825 		*commit = got_repo_get_cached_commit(repo, id);
826 		if (*commit != NULL) {
827 			(*commit)->refcnt++;
828 			return NULL;
829 		}
830 	} else
831 		*commit = NULL;
832 
833 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
834 	if (err == NULL) {
835 		struct got_pack *pack = NULL;
836 
837 		err = got_packidx_get_packfile_path(&path_packfile,
838 		    packidx->path_packidx);
839 		if (err)
840 			return err;
841 
842 		pack = got_repo_get_cached_pack(repo, path_packfile);
843 		if (pack == NULL) {
844 			err = got_repo_cache_pack(&pack, repo, path_packfile,
845 			    packidx);
846 			if (err)
847 				goto done;
848 		}
849 		err = read_packed_commit_privsep(commit, pack,
850 		    packidx, idx, id);
851 	} else if (err->code == GOT_ERR_NO_OBJ) {
852 		int fd;
853 
854 		err = got_object_open_loose_fd(&fd, id, repo);
855 		if (err)
856 			return err;
857 		err = read_commit_privsep(commit, fd, id, repo);
858 	}
859 
860 	if (err == NULL) {
861 		(*commit)->refcnt++;
862 		err = got_repo_cache_commit(repo, id, *commit);
863 	}
864 done:
865 	free(path_packfile);
866 	return err;
867 }
868 
869 const struct got_error *
870 got_object_open_as_commit(struct got_commit_object **commit,
871     struct got_repository *repo, struct got_object_id *id)
872 {
873 	*commit = got_repo_get_cached_commit(repo, id);
874 	if (*commit != NULL) {
875 		(*commit)->refcnt++;
876 		return NULL;
877 	}
878 
879 	return open_commit(commit, repo, id, 0);
880 }
881 
882 const struct got_error *
883 got_object_commit_open(struct got_commit_object **commit,
884     struct got_repository *repo, struct got_object *obj)
885 {
886 	return open_commit(commit, repo, got_object_get_id(obj), 1);
887 }
888 
889 const struct got_error *
890 got_object_qid_alloc(struct got_object_qid **qid, struct got_object_id *id)
891 {
892 	const struct got_error *err = NULL;
893 
894 	*qid = calloc(1, sizeof(**qid));
895 	if (*qid == NULL)
896 		return got_error_from_errno("calloc");
897 
898 	(*qid)->id = got_object_id_dup(id);
899 	if ((*qid)->id == NULL) {
900 		err = got_error_from_errno("got_object_id_dup");
901 		got_object_qid_free(*qid);
902 		*qid = NULL;
903 		return err;
904 	}
905 
906 	return NULL;
907 }
908 
909 const struct got_error *
910 got_object_id_queue_copy(const struct got_object_id_queue *src,
911     struct got_object_id_queue *dest)
912 {
913 	const struct got_error *err;
914 	struct got_object_qid *qid;
915 
916 	STAILQ_FOREACH(qid, src, entry) {
917 		struct got_object_qid *new;
918 		/*
919 		 * Deep-copy the object ID only. Let the caller deal
920 		 * with setting up the new->data pointer if needed.
921 		 */
922 		err = got_object_qid_alloc(&new, qid->id); 
923 		if (err) {
924 			got_object_id_queue_free(dest);
925 			return err;
926 		}
927 		STAILQ_INSERT_TAIL(dest, new, entry);
928 	}
929 
930 	return NULL;
931 }
932 
933 static const struct got_error *
934 request_packed_tree(struct got_tree_object **tree, struct got_pack *pack,
935     int pack_idx, struct got_object_id *id)
936 {
937 	const struct got_error *err = NULL;
938 
939 	err = got_privsep_send_tree_req(pack->privsep_child->ibuf, -1, id,
940 	    pack_idx);
941 	if (err)
942 		return err;
943 
944 	return got_privsep_recv_tree(tree, pack->privsep_child->ibuf);
945 }
946 
947 static const struct got_error *
948 read_packed_tree_privsep(struct got_tree_object **tree,
949     struct got_pack *pack, struct got_packidx *packidx, int idx,
950     struct got_object_id *id)
951 {
952 	const struct got_error *err = NULL;
953 
954 	if (pack->privsep_child)
955 		return request_packed_tree(tree, pack, idx, id);
956 
957 	err = start_pack_privsep_child(pack, packidx);
958 	if (err)
959 		return err;
960 
961 	return request_packed_tree(tree, pack, idx, id);
962 }
963 
964 static const struct got_error *
965 request_tree(struct got_tree_object **tree, struct got_repository *repo,
966     int fd, struct got_object_id *id)
967 {
968 	const struct got_error *err = NULL;
969 	struct imsgbuf *ibuf;
970 
971 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf;
972 
973 	err = got_privsep_send_tree_req(ibuf, fd, id, -1);
974 	if (err)
975 		return err;
976 
977 	return got_privsep_recv_tree(tree, ibuf);
978 }
979 
980 const struct got_error *
981 read_tree_privsep(struct got_tree_object **tree, int obj_fd,
982     struct got_object_id *id, struct got_repository *repo)
983 {
984 	const struct got_error *err;
985 	int imsg_fds[2];
986 	pid_t pid;
987 	struct imsgbuf *ibuf;
988 
989 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd != -1)
990 		return request_tree(tree, repo, obj_fd, id);
991 
992 	ibuf = calloc(1, sizeof(*ibuf));
993 	if (ibuf == NULL)
994 		return got_error_from_errno("calloc");
995 
996 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
997 		err = got_error_from_errno("socketpair");
998 		free(ibuf);
999 		return err;
1000 	}
1001 
1002 	pid = fork();
1003 	if (pid == -1) {
1004 		err = got_error_from_errno("fork");
1005 		free(ibuf);
1006 		return err;
1007 	}
1008 	else if (pid == 0) {
1009 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TREE,
1010 		    repo->path);
1011 		/* not reached */
1012 	}
1013 
1014 	if (close(imsg_fds[1]) == -1) {
1015 		err = got_error_from_errno("close");
1016 		free(ibuf);
1017 		return err;
1018 	}
1019 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd =
1020 	    imsg_fds[0];
1021 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].pid = pid;
1022 	imsg_init(ibuf, imsg_fds[0]);
1023 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf = ibuf;
1024 
1025 
1026 	return request_tree(tree, repo, obj_fd, id);
1027 }
1028 
1029 static const struct got_error *
1030 open_tree(struct got_tree_object **tree, struct got_repository *repo,
1031     struct got_object_id *id, int check_cache)
1032 {
1033 	const struct got_error *err = NULL;
1034 	struct got_packidx *packidx = NULL;
1035 	int idx;
1036 	char *path_packfile = NULL;
1037 
1038 	if (check_cache) {
1039 		*tree = got_repo_get_cached_tree(repo, id);
1040 		if (*tree != NULL) {
1041 			(*tree)->refcnt++;
1042 			return NULL;
1043 		}
1044 	} else
1045 		*tree = NULL;
1046 
1047 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1048 	if (err == NULL) {
1049 		struct got_pack *pack = NULL;
1050 
1051 		err = got_packidx_get_packfile_path(&path_packfile,
1052 		    packidx->path_packidx);
1053 		if (err)
1054 			return err;
1055 
1056 		pack = got_repo_get_cached_pack(repo, path_packfile);
1057 		if (pack == NULL) {
1058 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1059 			    packidx);
1060 			if (err)
1061 				goto done;
1062 		}
1063 		err = read_packed_tree_privsep(tree, pack,
1064 		    packidx, idx, id);
1065 	} else if (err->code == GOT_ERR_NO_OBJ) {
1066 		int fd;
1067 
1068 		err = got_object_open_loose_fd(&fd, id, repo);
1069 		if (err)
1070 			return err;
1071 		err = read_tree_privsep(tree, fd, id, repo);
1072 	}
1073 
1074 	if (err == NULL) {
1075 		(*tree)->refcnt++;
1076 		err = got_repo_cache_tree(repo, id, *tree);
1077 	}
1078 done:
1079 	free(path_packfile);
1080 	return err;
1081 }
1082 
1083 const struct got_error *
1084 got_object_open_as_tree(struct got_tree_object **tree,
1085     struct got_repository *repo, struct got_object_id *id)
1086 {
1087 	*tree = got_repo_get_cached_tree(repo, id);
1088 	if (*tree != NULL) {
1089 		(*tree)->refcnt++;
1090 		return NULL;
1091 	}
1092 
1093 	return open_tree(tree, repo, id, 0);
1094 }
1095 
1096 const struct got_error *
1097 got_object_tree_open(struct got_tree_object **tree,
1098     struct got_repository *repo, struct got_object *obj)
1099 {
1100 	return open_tree(tree, repo, got_object_get_id(obj), 1);
1101 }
1102 
1103 int
1104 got_object_tree_get_nentries(struct got_tree_object *tree)
1105 {
1106 	return tree->nentries;
1107 }
1108 
1109 struct got_tree_entry *
1110 got_object_tree_get_first_entry(struct got_tree_object *tree)
1111 {
1112 	return got_object_tree_get_entry(tree, 0);
1113 }
1114 
1115 struct got_tree_entry *
1116 got_object_tree_get_last_entry(struct got_tree_object *tree)
1117 {
1118 	return got_object_tree_get_entry(tree, tree->nentries - 1);
1119 }
1120 
1121 struct got_tree_entry *
1122 got_object_tree_get_entry(struct got_tree_object *tree, int i)
1123 {
1124 	if (i < 0 || i >= tree->nentries)
1125 		return NULL;
1126 	return &tree->entries[i];
1127 }
1128 
1129 mode_t
1130 got_tree_entry_get_mode(struct got_tree_entry *te)
1131 {
1132 	return te->mode;
1133 }
1134 
1135 const char *
1136 got_tree_entry_get_name(struct got_tree_entry *te)
1137 {
1138 	return &te->name[0];
1139 }
1140 
1141 struct got_object_id *
1142 got_tree_entry_get_id(struct got_tree_entry *te)
1143 {
1144 	return &te->id;
1145 }
1146 
1147 const struct got_error *
1148 got_object_blob_read_to_str(char **s, struct got_blob_object *blob)
1149 {
1150 	const struct got_error *err = NULL;
1151 	size_t len, totlen, hdrlen, offset;
1152 
1153 	*s = NULL;
1154 
1155 	hdrlen = got_object_blob_get_hdrlen(blob);
1156 	totlen = 0;
1157 	offset = 0;
1158 	do {
1159 		char *p;
1160 
1161 		err = got_object_blob_read_block(&len, blob);
1162 		if (err)
1163 			return err;
1164 
1165 		if (len == 0)
1166 			break;
1167 
1168 		totlen += len - hdrlen;
1169 		p = realloc(*s, totlen + 1);
1170 		if (p == NULL) {
1171 			err = got_error_from_errno("realloc");
1172 			free(*s);
1173 			*s = NULL;
1174 			return err;
1175 		}
1176 		*s = p;
1177 		/* Skip blob object header first time around. */
1178 		memcpy(*s + offset,
1179 		    got_object_blob_get_read_buf(blob) + hdrlen, len - hdrlen);
1180 		hdrlen = 0;
1181 		offset = totlen;
1182 	} while (len > 0);
1183 
1184 	(*s)[totlen] = '\0';
1185 	return NULL;
1186 }
1187 
1188 const struct got_error *
1189 got_tree_entry_get_symlink_target(char **link_target, struct got_tree_entry *te,
1190     struct got_repository *repo)
1191 {
1192 	const struct got_error *err = NULL;
1193 	struct got_blob_object *blob = NULL;
1194 
1195 	*link_target = NULL;
1196 
1197 	if (!got_object_tree_entry_is_symlink(te))
1198 		return got_error(GOT_ERR_TREE_ENTRY_TYPE);
1199 
1200 	err = got_object_open_as_blob(&blob, repo,
1201 	    got_tree_entry_get_id(te), PATH_MAX);
1202 	if (err)
1203 		return err;
1204 
1205 	err = got_object_blob_read_to_str(link_target, blob);
1206 	got_object_blob_close(blob);
1207 	if (err) {
1208 		free(*link_target);
1209 		*link_target = NULL;
1210 	}
1211 	return err;
1212 }
1213 
1214 int
1215 got_tree_entry_get_index(struct got_tree_entry *te)
1216 {
1217 	return te->idx;
1218 }
1219 
1220 struct got_tree_entry *
1221 got_tree_entry_get_next(struct got_tree_object *tree,
1222     struct got_tree_entry *te)
1223 {
1224 	return got_object_tree_get_entry(tree, te->idx + 1);
1225 }
1226 
1227 struct got_tree_entry *
1228 got_tree_entry_get_prev(struct got_tree_object *tree,
1229     struct got_tree_entry *te)
1230 {
1231 	return got_object_tree_get_entry(tree, te->idx - 1);
1232 }
1233 
1234 static const struct got_error *
1235 request_packed_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
1236     struct got_pack *pack, struct got_packidx *packidx, int idx,
1237     struct got_object_id *id)
1238 {
1239 	const struct got_error *err = NULL;
1240 	int outfd_child;
1241 	int basefd, accumfd; /* temporary files for delta application */
1242 
1243 	basefd = got_opentempfd();
1244 	if (basefd == -1)
1245 		return got_error_from_errno("got_opentempfd");
1246 	accumfd = got_opentempfd();
1247 	if (accumfd == -1)
1248 		return got_error_from_errno("got_opentempfd");
1249 
1250 	outfd_child = dup(outfd);
1251 	if (outfd_child == -1)
1252 		return got_error_from_errno("dup");
1253 
1254 	err = got_privsep_send_blob_req(pack->privsep_child->ibuf, -1, id, idx);
1255 	if (err)
1256 		return err;
1257 
1258 	err = got_privsep_send_blob_outfd(pack->privsep_child->ibuf,
1259 	    outfd_child);
1260 	if (err) {
1261 		close(basefd);
1262 		close(accumfd);
1263 		return err;
1264 	}
1265 
1266 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
1267 	    basefd);
1268 	if (err) {
1269 		close(accumfd);
1270 		return err;
1271 	}
1272 
1273 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
1274 	    accumfd);
1275 	if (err)
1276 		return err;
1277 
1278 	err = got_privsep_recv_blob(outbuf, size, hdrlen,
1279 	    pack->privsep_child->ibuf);
1280 	if (err)
1281 		return err;
1282 
1283 	if (lseek(outfd, SEEK_SET, 0) == -1)
1284 		err = got_error_from_errno("lseek");
1285 
1286 	return err;
1287 }
1288 
1289 static const struct got_error *
1290 read_packed_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1291     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
1292     struct got_object_id *id)
1293 {
1294 	const struct got_error *err = NULL;
1295 
1296 	if (pack->privsep_child == NULL) {
1297 		err = start_pack_privsep_child(pack, packidx);
1298 		if (err)
1299 			return err;
1300 	}
1301 
1302 	return request_packed_blob(outbuf, size, hdrlen, outfd, pack, packidx,
1303 	    idx, id);
1304 }
1305 
1306 static const struct got_error *
1307 request_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
1308     int infd, struct got_object_id *id, struct imsgbuf *ibuf)
1309 {
1310 	const struct got_error *err = NULL;
1311 	int outfd_child;
1312 
1313 	outfd_child = dup(outfd);
1314 	if (outfd_child == -1)
1315 		return got_error_from_errno("dup");
1316 
1317 	err = got_privsep_send_blob_req(ibuf, infd, id, -1);
1318 	if (err)
1319 		return err;
1320 
1321 	err = got_privsep_send_blob_outfd(ibuf, outfd_child);
1322 	if (err)
1323 		return err;
1324 
1325 	err = got_privsep_recv_blob(outbuf, size, hdrlen, ibuf);
1326 	if (err)
1327 		return err;
1328 
1329 	if (lseek(outfd, SEEK_SET, 0) == -1)
1330 		return got_error_from_errno("lseek");
1331 
1332 	return err;
1333 }
1334 
1335 static const struct got_error *
1336 read_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1337     int outfd, int infd, struct got_object_id *id, struct got_repository *repo)
1338 {
1339 	const struct got_error *err;
1340 	int imsg_fds[2];
1341 	pid_t pid;
1342 	struct imsgbuf *ibuf;
1343 
1344 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd != -1) {
1345 		ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf;
1346 		return request_blob(outbuf, size, hdrlen, outfd, infd, id,
1347 		    ibuf);
1348 	}
1349 
1350 	ibuf = calloc(1, sizeof(*ibuf));
1351 	if (ibuf == NULL)
1352 		return got_error_from_errno("calloc");
1353 
1354 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1355 		err = got_error_from_errno("socketpair");
1356 		free(ibuf);
1357 		return err;
1358 	}
1359 
1360 	pid = fork();
1361 	if (pid == -1) {
1362 		err = got_error_from_errno("fork");
1363 		free(ibuf);
1364 		return err;
1365 	}
1366 	else if (pid == 0) {
1367 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_BLOB,
1368 		    repo->path);
1369 		/* not reached */
1370 	}
1371 
1372 	if (close(imsg_fds[1]) == -1) {
1373 		err = got_error_from_errno("close");
1374 		free(ibuf);
1375 		return err;
1376 	}
1377 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd =
1378 	    imsg_fds[0];
1379 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].pid = pid;
1380 	imsg_init(ibuf, imsg_fds[0]);
1381 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf = ibuf;
1382 
1383 	return request_blob(outbuf, size, hdrlen, outfd, infd, id, ibuf);
1384 }
1385 
1386 static const struct got_error *
1387 open_blob(struct got_blob_object **blob, struct got_repository *repo,
1388     struct got_object_id *id, size_t blocksize)
1389 {
1390 	const struct got_error *err = NULL;
1391 	struct got_packidx *packidx = NULL;
1392 	int idx;
1393 	char *path_packfile = NULL;
1394 	uint8_t *outbuf;
1395 	int outfd;
1396 	size_t size, hdrlen;
1397 	struct stat sb;
1398 
1399 	*blob = calloc(1, sizeof(**blob));
1400 	if (*blob == NULL)
1401 		return got_error_from_errno("calloc");
1402 
1403 	outfd = got_opentempfd();
1404 	if (outfd == -1)
1405 		return got_error_from_errno("got_opentempfd");
1406 
1407 	(*blob)->read_buf = malloc(blocksize);
1408 	if ((*blob)->read_buf == NULL) {
1409 		err = got_error_from_errno("malloc");
1410 		goto done;
1411 	}
1412 
1413 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1414 	if (err == NULL) {
1415 		struct got_pack *pack = NULL;
1416 
1417 		err = got_packidx_get_packfile_path(&path_packfile,
1418 		    packidx->path_packidx);
1419 		if (err)
1420 			goto done;
1421 
1422 		pack = got_repo_get_cached_pack(repo, path_packfile);
1423 		if (pack == NULL) {
1424 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1425 			    packidx);
1426 			if (err)
1427 				goto done;
1428 		}
1429 		err = read_packed_blob_privsep(&outbuf, &size, &hdrlen, outfd,
1430 		    pack, packidx, idx, id);
1431 	} else if (err->code == GOT_ERR_NO_OBJ) {
1432 		int infd;
1433 
1434 		err = got_object_open_loose_fd(&infd, id, repo);
1435 		if (err)
1436 			goto done;
1437 		err = read_blob_privsep(&outbuf, &size, &hdrlen, outfd, infd,
1438 		    id, repo);
1439 	}
1440 	if (err)
1441 		goto done;
1442 
1443 	if (hdrlen > size) {
1444 		err = got_error(GOT_ERR_BAD_OBJ_HDR);
1445 		goto done;
1446 	}
1447 
1448 	if (outbuf) {
1449 		if (close(outfd) == -1 && err == NULL)
1450 			err = got_error_from_errno("close");
1451 		outfd = -1;
1452 		(*blob)->f = fmemopen(outbuf, size, "rb");
1453 		if ((*blob)->f == NULL) {
1454 			err = got_error_from_errno("fmemopen");
1455 			free(outbuf);
1456 			goto done;
1457 		}
1458 		(*blob)->data = outbuf;
1459 	} else {
1460 		if (fstat(outfd, &sb) == -1) {
1461 			err = got_error_from_errno("fstat");
1462 			goto done;
1463 		}
1464 
1465 		if (sb.st_size != size) {
1466 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1467 			goto done;
1468 		}
1469 
1470 		(*blob)->f = fdopen(outfd, "rb");
1471 		if ((*blob)->f == NULL) {
1472 			err = got_error_from_errno("fdopen");
1473 			close(outfd);
1474 			outfd = -1;
1475 			goto done;
1476 		}
1477 	}
1478 
1479 	(*blob)->hdrlen = hdrlen;
1480 	(*blob)->blocksize = blocksize;
1481 	memcpy(&(*blob)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
1482 
1483 done:
1484 	free(path_packfile);
1485 	if (err) {
1486 		if (*blob) {
1487 			got_object_blob_close(*blob);
1488 			*blob = NULL;
1489 		} else if (outfd != -1)
1490 			close(outfd);
1491 	}
1492 	return err;
1493 }
1494 
1495 const struct got_error *
1496 got_object_open_as_blob(struct got_blob_object **blob,
1497     struct got_repository *repo, struct got_object_id *id,
1498     size_t blocksize)
1499 {
1500 	return open_blob(blob, repo, id, blocksize);
1501 }
1502 
1503 const struct got_error *
1504 got_object_blob_open(struct got_blob_object **blob,
1505     struct got_repository *repo, struct got_object *obj, size_t blocksize)
1506 {
1507 	return open_blob(blob, repo, got_object_get_id(obj), blocksize);
1508 }
1509 
1510 const struct got_error *
1511 got_object_blob_close(struct got_blob_object *blob)
1512 {
1513 	const struct got_error *err = NULL;
1514 	free(blob->read_buf);
1515 	if (blob->f && fclose(blob->f) == EOF)
1516 		err = got_error_from_errno("fclose");
1517 	free(blob->data);
1518 	free(blob);
1519 	return err;
1520 }
1521 
1522 void
1523 got_object_blob_rewind(struct got_blob_object *blob)
1524 {
1525 	if (blob->f)
1526 		rewind(blob->f);
1527 }
1528 
1529 char *
1530 got_object_blob_id_str(struct got_blob_object *blob, char *buf, size_t size)
1531 {
1532 	return got_sha1_digest_to_str(blob->id.sha1, buf, size);
1533 }
1534 
1535 size_t
1536 got_object_blob_get_hdrlen(struct got_blob_object *blob)
1537 {
1538 	return blob->hdrlen;
1539 }
1540 
1541 const uint8_t *
1542 got_object_blob_get_read_buf(struct got_blob_object *blob)
1543 {
1544 	return blob->read_buf;
1545 }
1546 
1547 const struct got_error *
1548 got_object_blob_read_block(size_t *outlenp, struct got_blob_object *blob)
1549 {
1550 	size_t n;
1551 
1552 	n = fread(blob->read_buf, 1, blob->blocksize, blob->f);
1553 	if (n == 0 && ferror(blob->f))
1554 		return got_ferror(blob->f, GOT_ERR_IO);
1555 	*outlenp = n;
1556 	return NULL;
1557 }
1558 
1559 const struct got_error *
1560 got_object_blob_dump_to_file(off_t *filesize, int *nlines,
1561     off_t **line_offsets, FILE *outfile, struct got_blob_object *blob)
1562 {
1563 	const struct got_error *err = NULL;
1564 	size_t n, len, hdrlen;
1565 	const uint8_t *buf;
1566 	int i;
1567 	const int alloc_chunksz = 512;
1568 	size_t nalloc = 0;
1569 	off_t off = 0, total_len = 0;
1570 
1571 	if (line_offsets)
1572 		*line_offsets = NULL;
1573 	if (filesize)
1574 		*filesize = 0;
1575 	if (nlines)
1576 		*nlines = 0;
1577 
1578 	hdrlen = got_object_blob_get_hdrlen(blob);
1579 	do {
1580 		err = got_object_blob_read_block(&len, blob);
1581 		if (err)
1582 			return err;
1583 		if (len == 0)
1584 			break;
1585 		buf = got_object_blob_get_read_buf(blob);
1586 		i = hdrlen;
1587 		if (nlines) {
1588 			if (line_offsets && *line_offsets == NULL) {
1589 				/* Have some data but perhaps no '\n'. */
1590 				*nlines = 1;
1591 				nalloc = alloc_chunksz;
1592 				*line_offsets = calloc(nalloc,
1593 				    sizeof(**line_offsets));
1594 				if (*line_offsets == NULL)
1595 					return got_error_from_errno("calloc");
1596 
1597 				/* Skip forward over end of first line. */
1598 				while (i < len) {
1599 					if (buf[i] == '\n')
1600 						break;
1601 					i++;
1602 				}
1603 			}
1604 			/* Scan '\n' offsets in remaining chunk of data. */
1605 			while (i < len) {
1606 				if (buf[i] != '\n') {
1607 					i++;
1608 					continue;
1609 				}
1610 				(*nlines)++;
1611 				if (line_offsets && nalloc < *nlines) {
1612 					size_t n = *nlines + alloc_chunksz;
1613 					off_t *o = recallocarray(*line_offsets,
1614 					    nalloc, n, sizeof(**line_offsets));
1615 					if (o == NULL) {
1616 						free(*line_offsets);
1617 						*line_offsets = NULL;
1618 						return got_error_from_errno(
1619 						    "recallocarray");
1620 					}
1621 					*line_offsets = o;
1622 					nalloc = n;
1623 				}
1624 				if (line_offsets) {
1625 					off = total_len + i - hdrlen + 1;
1626 					(*line_offsets)[*nlines - 1] = off;
1627 				}
1628 				i++;
1629 			}
1630 		}
1631 		/* Skip blob object header first time around. */
1632 		n = fwrite(buf + hdrlen, 1, len - hdrlen, outfile);
1633 		if (n != len - hdrlen)
1634 			return got_ferror(outfile, GOT_ERR_IO);
1635 		total_len += len - hdrlen;
1636 		hdrlen = 0;
1637 	} while (len != 0);
1638 
1639 	if (fflush(outfile) != 0)
1640 		return got_error_from_errno("fflush");
1641 	rewind(outfile);
1642 
1643 	if (filesize)
1644 		*filesize = total_len;
1645 
1646 	return NULL;
1647 }
1648 
1649 static const struct got_error *
1650 request_packed_tag(struct got_tag_object **tag, struct got_pack *pack,
1651     int pack_idx, struct got_object_id *id)
1652 {
1653 	const struct got_error *err = NULL;
1654 
1655 	err = got_privsep_send_tag_req(pack->privsep_child->ibuf, -1, id,
1656 	    pack_idx);
1657 	if (err)
1658 		return err;
1659 
1660 	return got_privsep_recv_tag(tag, pack->privsep_child->ibuf);
1661 }
1662 
1663 static const struct got_error *
1664 read_packed_tag_privsep(struct got_tag_object **tag,
1665     struct got_pack *pack, struct got_packidx *packidx, int idx,
1666     struct got_object_id *id)
1667 {
1668 	const struct got_error *err = NULL;
1669 
1670 	if (pack->privsep_child)
1671 		return request_packed_tag(tag, pack, idx, id);
1672 
1673 	err = start_pack_privsep_child(pack, packidx);
1674 	if (err)
1675 		return err;
1676 
1677 	return request_packed_tag(tag, pack, idx, id);
1678 }
1679 
1680 static const struct got_error *
1681 request_tag(struct got_tag_object **tag, struct got_repository *repo,
1682     int fd, struct got_object_id *id)
1683 {
1684 	const struct got_error *err = NULL;
1685 	struct imsgbuf *ibuf;
1686 
1687 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf;
1688 
1689 	err = got_privsep_send_tag_req(ibuf, fd, id, -1);
1690 	if (err)
1691 		return err;
1692 
1693 	return got_privsep_recv_tag(tag, ibuf);
1694 }
1695 
1696 static const struct got_error *
1697 read_tag_privsep(struct got_tag_object **tag, int obj_fd,
1698     struct got_object_id *id, struct got_repository *repo)
1699 {
1700 	const struct got_error *err;
1701 	int imsg_fds[2];
1702 	pid_t pid;
1703 	struct imsgbuf *ibuf;
1704 
1705 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd != -1)
1706 		return request_tag(tag, repo, obj_fd, id);
1707 
1708 	ibuf = calloc(1, sizeof(*ibuf));
1709 	if (ibuf == NULL)
1710 		return got_error_from_errno("calloc");
1711 
1712 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1713 		err = got_error_from_errno("socketpair");
1714 		free(ibuf);
1715 		return err;
1716 	}
1717 
1718 	pid = fork();
1719 	if (pid == -1) {
1720 		err = got_error_from_errno("fork");
1721 		free(ibuf);
1722 		return err;
1723 	}
1724 	else if (pid == 0) {
1725 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_TAG,
1726 		    repo->path);
1727 		/* not reached */
1728 	}
1729 
1730 	if (close(imsg_fds[1]) == -1) {
1731 		err = got_error_from_errno("close");
1732 		free(ibuf);
1733 		return err;
1734 	}
1735 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd =
1736 	    imsg_fds[0];
1737 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].pid = pid;
1738 	imsg_init(ibuf, imsg_fds[0]);
1739 	repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf = ibuf;
1740 
1741 	return request_tag(tag, repo, obj_fd, id);
1742 }
1743 
1744 static const struct got_error *
1745 open_tag(struct got_tag_object **tag, struct got_repository *repo,
1746     struct got_object_id *id, int check_cache)
1747 {
1748 	const struct got_error *err = NULL;
1749 	struct got_packidx *packidx = NULL;
1750 	int idx;
1751 	char *path_packfile = NULL;
1752 	struct got_object *obj = NULL;
1753 	int obj_type = GOT_OBJ_TYPE_ANY;
1754 
1755 	if (check_cache) {
1756 		*tag = got_repo_get_cached_tag(repo, id);
1757 		if (*tag != NULL) {
1758 			(*tag)->refcnt++;
1759 			return NULL;
1760 		}
1761 	} else
1762 		*tag = NULL;
1763 
1764 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1765 	if (err == NULL) {
1766 		struct got_pack *pack = NULL;
1767 
1768 		err = got_packidx_get_packfile_path(&path_packfile,
1769 		    packidx->path_packidx);
1770 		if (err)
1771 			return err;
1772 
1773 		pack = got_repo_get_cached_pack(repo, path_packfile);
1774 		if (pack == NULL) {
1775 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1776 			    packidx);
1777 			if (err)
1778 				goto done;
1779 		}
1780 
1781 		/* Beware of "lightweight" tags: Check object type first. */
1782 		err = read_packed_object_privsep(&obj, repo, pack, packidx,
1783 		    idx, id);
1784 		if (err)
1785 			goto done;
1786 		obj_type = obj->type;
1787 		got_object_close(obj);
1788 		if (obj_type != GOT_OBJ_TYPE_TAG) {
1789 			err = got_error(GOT_ERR_OBJ_TYPE);
1790 			goto done;
1791 		}
1792 		err = read_packed_tag_privsep(tag, pack, packidx, idx, id);
1793 	} else if (err->code == GOT_ERR_NO_OBJ) {
1794 		int fd;
1795 
1796 		err = got_object_open_loose_fd(&fd, id, repo);
1797 		if (err)
1798 			return err;
1799 		err = got_object_read_header_privsep(&obj, id, repo, fd);
1800 		if (err)
1801 			return err;
1802 		obj_type = obj->type;
1803 		got_object_close(obj);
1804 		if (obj_type != GOT_OBJ_TYPE_TAG)
1805 			return got_error(GOT_ERR_OBJ_TYPE);
1806 
1807 		err = got_object_open_loose_fd(&fd, id, repo);
1808 		if (err)
1809 			return err;
1810 		err = read_tag_privsep(tag, fd, id, repo);
1811 	}
1812 
1813 	if (err == NULL) {
1814 		(*tag)->refcnt++;
1815 		err = got_repo_cache_tag(repo, id, *tag);
1816 	}
1817 done:
1818 	free(path_packfile);
1819 	return err;
1820 }
1821 
1822 const struct got_error *
1823 got_object_open_as_tag(struct got_tag_object **tag,
1824     struct got_repository *repo, struct got_object_id *id)
1825 {
1826 	*tag = got_repo_get_cached_tag(repo, id);
1827 	if (*tag != NULL) {
1828 		(*tag)->refcnt++;
1829 		return NULL;
1830 	}
1831 
1832 	return open_tag(tag, repo, id, 0);
1833 }
1834 
1835 const struct got_error *
1836 got_object_tag_open(struct got_tag_object **tag,
1837     struct got_repository *repo, struct got_object *obj)
1838 {
1839 	return open_tag(tag, repo, got_object_get_id(obj), 1);
1840 }
1841 
1842 const char *
1843 got_object_tag_get_name(struct got_tag_object *tag)
1844 {
1845 	return tag->tag;
1846 }
1847 
1848 int
1849 got_object_tag_get_object_type(struct got_tag_object *tag)
1850 {
1851 	return tag->obj_type;
1852 }
1853 
1854 struct got_object_id *
1855 got_object_tag_get_object_id(struct got_tag_object *tag)
1856 {
1857 	return &tag->id;
1858 }
1859 
1860 time_t
1861 got_object_tag_get_tagger_time(struct got_tag_object *tag)
1862 {
1863 	return tag->tagger_time;
1864 }
1865 
1866 time_t
1867 got_object_tag_get_tagger_gmtoff(struct got_tag_object *tag)
1868 {
1869 	return tag->tagger_gmtoff;
1870 }
1871 
1872 const char *
1873 got_object_tag_get_tagger(struct got_tag_object *tag)
1874 {
1875 	return tag->tagger;
1876 }
1877 
1878 const char *
1879 got_object_tag_get_message(struct got_tag_object *tag)
1880 {
1881 	return tag->tagmsg;
1882 }
1883 
1884 static struct got_tree_entry *
1885 find_entry_by_name(struct got_tree_object *tree, const char *name, size_t len)
1886 {
1887 	int i;
1888 
1889 	/* Note that tree entries are sorted in strncmp() order. */
1890 	for (i = 0; i < tree->nentries; i++) {
1891 		struct got_tree_entry *te = &tree->entries[i];
1892 		int cmp = strncmp(te->name, name, len);
1893 		if (cmp < 0)
1894 			continue;
1895 		if (cmp > 0)
1896 			break;
1897 		if (te->name[len] == '\0')
1898 			return te;
1899 	}
1900 	return NULL;
1901 }
1902 
1903 struct got_tree_entry *
1904 got_object_tree_find_entry(struct got_tree_object *tree, const char *name)
1905 {
1906 	return find_entry_by_name(tree, name, strlen(name));
1907 }
1908 
1909 const struct got_error *
1910 got_object_tree_find_path(struct got_object_id **id, mode_t *mode,
1911     struct got_repository *repo, struct got_tree_object *tree,
1912     const char *path)
1913 {
1914 	const struct got_error *err = NULL;
1915 	struct got_tree_object *subtree = NULL;
1916 	struct got_tree_entry *te = NULL;
1917 	const char *seg, *s;
1918 	size_t seglen;
1919 
1920 	*id = NULL;
1921 
1922 	s = path;
1923 	while (s[0] == '/')
1924 		s++;
1925 	seg = s;
1926 	seglen = 0;
1927 	subtree = tree;
1928 	while (*s) {
1929 		struct got_tree_object *next_tree;
1930 
1931 		if (*s != '/') {
1932 			s++;
1933 			seglen++;
1934 			if (*s)
1935 				continue;
1936 		}
1937 
1938 		te = find_entry_by_name(subtree, seg, seglen);
1939 		if (te == NULL) {
1940 			err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
1941 			goto done;
1942 		}
1943 
1944 		if (*s == '\0')
1945 			break;
1946 
1947 		seg = s + 1;
1948 		seglen = 0;
1949 		s++;
1950 		if (*s) {
1951 			err = got_object_open_as_tree(&next_tree, repo,
1952 			    &te->id);
1953 			te = NULL;
1954 			if (err)
1955 				goto done;
1956 			if (subtree != tree)
1957 				got_object_tree_close(subtree);
1958 			subtree = next_tree;
1959 		}
1960 	}
1961 
1962 	if (te) {
1963 		*id = got_object_id_dup(&te->id);
1964 		if (*id == NULL)
1965 			return got_error_from_errno("got_object_id_dup");
1966 		if (mode)
1967 			*mode = te->mode;
1968 	} else
1969 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
1970 done:
1971 	if (subtree && subtree != tree)
1972 		got_object_tree_close(subtree);
1973 	return err;
1974 }
1975 const struct got_error *
1976 got_object_id_by_path(struct got_object_id **id, struct got_repository *repo,
1977     struct got_object_id *commit_id, const char *path)
1978 {
1979 	const struct got_error *err = NULL;
1980 	struct got_commit_object *commit = NULL;
1981 	struct got_tree_object *tree = NULL;
1982 
1983 	*id = NULL;
1984 
1985 	err = got_object_open_as_commit(&commit, repo, commit_id);
1986 	if (err)
1987 		goto done;
1988 
1989 	/* Handle opening of root of commit's tree. */
1990 	if (got_path_is_root_dir(path)) {
1991 		*id = got_object_id_dup(commit->tree_id);
1992 		if (*id == NULL)
1993 			err = got_error_from_errno("got_object_id_dup");
1994 	} else {
1995 		err = got_object_open_as_tree(&tree, repo, commit->tree_id);
1996 		if (err)
1997 			goto done;
1998 		err = got_object_tree_find_path(id, NULL, repo, tree, path);
1999 	}
2000 done:
2001 	if (commit)
2002 		got_object_commit_close(commit);
2003 	if (tree)
2004 		got_object_tree_close(tree);
2005 	return err;
2006 }
2007 
2008 /*
2009  * Normalize file mode bits to avoid false positive tree entry differences
2010  * in case tree entries have unexpected mode bits set.
2011  */
2012 static mode_t
2013 normalize_mode_for_comparison(mode_t mode)
2014 {
2015 	/*
2016 	 * For directories, the only relevant bit is the IFDIR bit.
2017 	 * This allows us to detect paths changing from a directory
2018 	 * to a file and vice versa.
2019 	 */
2020 	if (S_ISDIR(mode))
2021 		return mode & S_IFDIR;
2022 
2023 	/*
2024 	 * For symlinks, the only relevant bit is the IFLNK bit.
2025 	 * This allows us to detect paths changing from a symlinks
2026 	 * to a file or directory and vice versa.
2027 	 */
2028 	if (S_ISLNK(mode))
2029 		return mode & S_IFLNK;
2030 
2031 	/* For files, the only change we care about is the executable bit. */
2032 	return mode & S_IXUSR;
2033 }
2034 
2035 const struct got_error *
2036 got_object_tree_path_changed(int *changed,
2037     struct got_tree_object *tree01, struct got_tree_object *tree02,
2038     const char *path, struct got_repository *repo)
2039 {
2040 	const struct got_error *err = NULL;
2041 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
2042 	struct got_tree_entry *te1 = NULL, *te2 = NULL;
2043 	const char *seg, *s;
2044 	size_t seglen;
2045 
2046 	*changed = 0;
2047 
2048 	/* We not do support comparing the root path. */
2049 	if (got_path_is_root_dir(path))
2050 		return got_error_path(path, GOT_ERR_BAD_PATH);
2051 
2052 	tree1 = tree01;
2053 	tree2 = tree02;
2054 	s = path;
2055 	while (*s == '/')
2056 		s++;
2057 	seg = s;
2058 	seglen = 0;
2059 	while (*s) {
2060 		struct got_tree_object *next_tree1, *next_tree2;
2061 		mode_t mode1, mode2;
2062 
2063 		if (*s != '/') {
2064 			s++;
2065 			seglen++;
2066 			if (*s)
2067 				continue;
2068 		}
2069 
2070 		te1 = find_entry_by_name(tree1, seg, seglen);
2071 		if (te1 == NULL) {
2072 			err = got_error(GOT_ERR_NO_OBJ);
2073 			goto done;
2074 		}
2075 
2076 		if (tree2)
2077 			te2 = find_entry_by_name(tree2, seg, seglen);
2078 
2079 		if (te2) {
2080 			mode1 = normalize_mode_for_comparison(te1->mode);
2081 			mode2 = normalize_mode_for_comparison(te2->mode);
2082 			if (mode1 != mode2) {
2083 				*changed = 1;
2084 				goto done;
2085 			}
2086 
2087 			if (got_object_id_cmp(&te1->id, &te2->id) == 0) {
2088 				*changed = 0;
2089 				goto done;
2090 			}
2091 		}
2092 
2093 		if (*s == '\0') { /* final path element */
2094 			*changed = 1;
2095 			goto done;
2096 		}
2097 
2098 		seg = s + 1;
2099 		s++;
2100 		seglen = 0;
2101 		if (*s) {
2102 			err = got_object_open_as_tree(&next_tree1, repo,
2103 			    &te1->id);
2104 			te1 = NULL;
2105 			if (err)
2106 				goto done;
2107 			if (tree1 != tree01)
2108 				got_object_tree_close(tree1);
2109 			tree1 = next_tree1;
2110 
2111 			if (te2) {
2112 				err = got_object_open_as_tree(&next_tree2, repo,
2113 				    &te2->id);
2114 				te2 = NULL;
2115 				if (err)
2116 					goto done;
2117 				if (tree2 != tree02)
2118 					got_object_tree_close(tree2);
2119 				tree2 = next_tree2;
2120 			} else if (tree2) {
2121 				if (tree2 != tree02)
2122 					got_object_tree_close(tree2);
2123 				tree2 = NULL;
2124 			}
2125 		}
2126 	}
2127 done:
2128 	if (tree1 && tree1 != tree01)
2129 		got_object_tree_close(tree1);
2130 	if (tree2 && tree2 != tree02)
2131 		got_object_tree_close(tree2);
2132 	return err;
2133 }
2134 
2135 const struct got_error *
2136 got_object_tree_entry_dup(struct got_tree_entry **new_te,
2137     struct got_tree_entry *te)
2138 {
2139 	const struct got_error *err = NULL;
2140 
2141 	*new_te = calloc(1, sizeof(**new_te));
2142 	if (*new_te == NULL)
2143 		return got_error_from_errno("calloc");
2144 
2145 	(*new_te)->mode = te->mode;
2146 	memcpy((*new_te)->name, te->name, sizeof((*new_te)->name));
2147 	memcpy(&(*new_te)->id, &te->id, sizeof((*new_te)->id));
2148 	return err;
2149 }
2150 
2151 int
2152 got_object_tree_entry_is_submodule(struct got_tree_entry *te)
2153 {
2154 	return (te->mode & S_IFMT) == (S_IFDIR | S_IFLNK);
2155 }
2156 
2157 int
2158 got_object_tree_entry_is_symlink(struct got_tree_entry *te)
2159 {
2160 	/* S_IFDIR check avoids confusing symlinks with submodules. */
2161 	return ((te->mode & (S_IFDIR | S_IFLNK)) == S_IFLNK);
2162 }
2163 
2164 static const struct got_error *
2165 resolve_symlink(char **link_target, const char *path,
2166     struct got_object_id *commit_id, struct got_repository *repo)
2167 {
2168 	const struct got_error *err = NULL;
2169 	char buf[PATH_MAX];
2170 	char *name, *parent_path = NULL;
2171 	struct got_object_id *tree_obj_id = NULL;
2172 	struct got_tree_object *tree = NULL;
2173 	struct got_tree_entry *te = NULL;
2174 
2175 	*link_target = NULL;
2176 
2177 	if (strlcpy(buf, path, sizeof(buf)) >= sizeof(buf))
2178 		return got_error(GOT_ERR_NO_SPACE);
2179 
2180 	name = basename(buf);
2181 	if (name == NULL)
2182 		return got_error_from_errno2("basename", path);
2183 
2184 	err = got_path_dirname(&parent_path, path);
2185 	if (err)
2186 		return err;
2187 
2188 	err = got_object_id_by_path(&tree_obj_id, repo, commit_id,
2189 	    parent_path);
2190 	if (err) {
2191 		if (err->code == GOT_ERR_NO_TREE_ENTRY) {
2192 			/* Display the complete path in error message. */
2193 			err = got_error_path(path, err->code);
2194 		}
2195 		goto done;
2196 	}
2197 
2198 	err = got_object_open_as_tree(&tree, repo, tree_obj_id);
2199 	if (err)
2200 		goto done;
2201 
2202 	te = got_object_tree_find_entry(tree, name);
2203 	if (te == NULL) {
2204 		err = got_error_path(path, GOT_ERR_NO_TREE_ENTRY);
2205 		goto done;
2206 	}
2207 
2208 	if (got_object_tree_entry_is_symlink(te)) {
2209 		err = got_tree_entry_get_symlink_target(link_target, te, repo);
2210 		if (err)
2211 			goto done;
2212 		if (!got_path_is_absolute(*link_target)) {
2213 			char *abspath;
2214 			if (asprintf(&abspath, "%s/%s", parent_path,
2215 			    *link_target) == -1) {
2216 				err = got_error_from_errno("asprintf");
2217 				goto done;
2218 			}
2219 			free(*link_target);
2220 			*link_target = malloc(PATH_MAX);
2221 			if (*link_target == NULL) {
2222 				err = got_error_from_errno("malloc");
2223 				goto done;
2224 			}
2225 			err = got_canonpath(abspath, *link_target, PATH_MAX);
2226 			free(abspath);
2227 			if (err)
2228 				goto done;
2229 		}
2230 	}
2231 done:
2232 	free(tree_obj_id);
2233 	if (tree)
2234 		got_object_tree_close(tree);
2235 	if (err) {
2236 		free(*link_target);
2237 		*link_target = NULL;
2238 	}
2239 	return err;
2240 }
2241 
2242 const struct got_error *
2243 got_object_resolve_symlinks(char **link_target, const char *path,
2244     struct got_object_id *commit_id, struct got_repository *repo)
2245 {
2246 	const struct got_error *err = NULL;
2247 	char *next_target = NULL;
2248 	int max_recursion = 40; /* matches Git */
2249 
2250 	*link_target = NULL;
2251 
2252 	do {
2253 		err = resolve_symlink(&next_target,
2254 		    *link_target ? *link_target : path, commit_id, repo);
2255 		if (err)
2256 			break;
2257 		if (next_target) {
2258 			free(*link_target);
2259 			if (--max_recursion == 0) {
2260 				err = got_error_path(path, GOT_ERR_RECURSION);
2261 				*link_target = NULL;
2262 				break;
2263 			}
2264 			*link_target = next_target;
2265 		}
2266 	} while (next_target);
2267 
2268 	return err;
2269 }
2270 
2271 const struct got_error *
2272 got_traverse_packed_commits(struct got_object_id_queue *traversed_commits,
2273     struct got_object_id *commit_id, const char *path,
2274     struct got_repository *repo)
2275 {
2276 	const struct got_error *err = NULL;
2277 	struct got_pack *pack = NULL;
2278 	struct got_packidx *packidx = NULL;
2279 	char *path_packfile = NULL;
2280 	struct got_commit_object *changed_commit = NULL;
2281 	struct got_object_id *changed_commit_id = NULL;
2282 	int idx;
2283 
2284 	err = got_repo_search_packidx(&packidx, &idx, repo, commit_id);
2285 	if (err) {
2286 		if (err->code != GOT_ERR_NO_OBJ)
2287 			return err;
2288 		return NULL;
2289 	}
2290 
2291 	err = got_packidx_get_packfile_path(&path_packfile,
2292 	    packidx->path_packidx);
2293 	if (err)
2294 		return err;
2295 
2296 	pack = got_repo_get_cached_pack(repo, path_packfile);
2297 	if (pack == NULL) {
2298 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
2299 		if (err)
2300 			goto done;
2301 	}
2302 
2303 	if (pack->privsep_child == NULL) {
2304 		err = start_pack_privsep_child(pack, packidx);
2305 		if (err)
2306 			goto done;
2307 	}
2308 
2309 	err = got_privsep_send_commit_traversal_request(
2310 	    pack->privsep_child->ibuf, commit_id, idx, path);
2311 	if (err)
2312 		goto done;
2313 
2314 	err = got_privsep_recv_traversed_commits(&changed_commit,
2315 	    &changed_commit_id, traversed_commits, pack->privsep_child->ibuf);
2316 	if (err)
2317 		goto done;
2318 
2319 	if (changed_commit) {
2320 		/*
2321 		 * Cache the commit in which the path was changed.
2322 		 * This commit might be opened again soon.
2323 		 */
2324 		changed_commit->refcnt++;
2325 		err = got_repo_cache_commit(repo, changed_commit_id,
2326 		    changed_commit);
2327 		got_object_commit_close(changed_commit);
2328 	}
2329 done:
2330 	free(path_packfile);
2331 	free(changed_commit_id);
2332 	return err;
2333 }