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