1 /*
2  * Copyright (c) 2018, 2019, 2022 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/mman.h>
18 #include <sys/queue.h>
19 #include <sys/types.h>
20 #include <sys/tree.h>
21 #include <sys/stat.h>
22 #include <sys/socket.h>
23 #include <sys/uio.h>
24 
25 #include <errno.h>
26 #include <imsg.h>
27 #include <stdio.h>
28 #include <stdint.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <sha1.h>
32 #include <limits.h>
33 #include <unistd.h>
34 
35 #include "got_error.h"
36 #include "got_object.h"
37 #include "got_repository.h"
38 #include "got_opentemp.h"
39 #include "got_path.h"
40 
41 #include "got_lib_delta.h"
42 #include "got_lib_object.h"
43 #include "got_lib_privsep.h"
44 #include "got_lib_object_cache.h"
45 #include "got_lib_pack.h"
46 #include "got_lib_repository.h"
47 
48 static const struct got_error *
49 request_packed_object(struct got_object **obj, struct got_pack *pack, int idx,
50     struct got_object_id *id)
51 {
52 	const struct got_error *err = NULL;
53 	struct imsgbuf *ibuf = pack->privsep_child->ibuf;
54 
55 	err = got_privsep_send_packed_obj_req(ibuf, idx, id);
56 	if (err)
57 		return err;
58 
59 	err = got_privsep_recv_obj(obj, ibuf);
60 	if (err)
61 		return err;
62 
63 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
64 
65 	return NULL;
66 }
67 
68 /* Create temporary files used during delta application. */
69 static const struct got_error *
70 pack_child_send_tempfiles(struct imsgbuf *ibuf, struct got_pack *pack)
71 {
72 	const struct got_error *err;
73 	int basefd = -1, accumfd = -1;
74 
75 	/*
76 	 * For performance reasons, the child will keep reusing the
77 	 * same temporary files during every object request.
78 	 * Opening and closing new files for every object request is
79 	 * too expensive during operations such as 'gotadmin pack'.
80 	 */
81 	if (pack->child_has_tempfiles)
82 		return NULL;
83 
84 	basefd = dup(pack->basefd);
85 	if (basefd == -1)
86 		return got_error_from_errno("dup");
87 
88 	accumfd = dup(pack->accumfd);
89 	if (accumfd == -1) {
90 		err = got_error_from_errno("dup");
91 		goto done;
92 	}
93 
94 	err = got_privsep_send_tmpfd(ibuf, basefd);
95 	if (err)
96 		goto done;
97 
98 	err = got_privsep_send_tmpfd(ibuf, accumfd);
99 done:
100 	if (err) {
101 		if (basefd != -1)
102 			close(basefd);
103 		if (accumfd != -1)
104 			close(accumfd);
105 	} else
106 		pack->child_has_tempfiles = 1;
107 	return NULL;
108 }
109 
110 static const struct got_error *
111 request_packed_object_raw(uint8_t **outbuf, off_t *size, size_t *hdrlen,
112     int outfd, struct got_pack *pack, int idx, struct got_object_id *id)
113 {
114 	const struct got_error *err = NULL;
115 	struct imsgbuf *ibuf = pack->privsep_child->ibuf;
116 	int outfd_child;
117 
118 	 err = pack_child_send_tempfiles(ibuf, pack);
119 	 if (err)
120 		return err;
121 
122 	outfd_child = dup(outfd);
123 	if (outfd_child == -1)
124 		return got_error_from_errno("dup");
125 
126 	err = got_privsep_send_packed_raw_obj_req(ibuf, idx, id);
127 	if (err) {
128 		close(outfd_child);
129 		return err;
130 	}
131 
132 	err = got_privsep_send_raw_obj_outfd(ibuf, outfd_child);
133 	if (err)
134 		return err;
135 
136 	err = got_privsep_recv_raw_obj(outbuf, size, hdrlen, ibuf);
137 	if (err)
138 		return err;
139 
140 	return NULL;
141 }
142 
143 static const struct got_error *
144 read_packed_object_privsep(struct got_object **obj,
145     struct got_repository *repo, struct got_pack *pack,
146     struct got_packidx *packidx, int idx, struct got_object_id *id)
147 {
148 	const struct got_error *err = NULL;
149 
150 	if (pack->privsep_child == NULL) {
151 		err = got_pack_start_privsep_child(pack, packidx);
152 		if (err)
153 			return err;
154 	}
155 
156 	return request_packed_object(obj, pack, idx, id);
157 }
158 
159 static const struct got_error *
160 read_packed_object_raw_privsep(uint8_t **outbuf, off_t *size, size_t *hdrlen,
161     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
162     struct got_object_id *id)
163 {
164 	const struct got_error *err = NULL;
165 
166 	if (pack->privsep_child == NULL) {
167 		err = got_pack_start_privsep_child(pack, packidx);
168 		if (err)
169 			return err;
170 	}
171 
172 	return request_packed_object_raw(outbuf, size, hdrlen, outfd, pack,
173 	    idx, id);
174 }
175 
176 const struct got_error *
177 got_object_open_packed(struct got_object **obj, struct got_object_id *id,
178     struct got_repository *repo)
179 {
180 	const struct got_error *err = NULL;
181 	struct got_pack *pack = NULL;
182 	struct got_packidx *packidx = NULL;
183 	int idx;
184 	char *path_packfile;
185 
186 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
187 	if (err)
188 		return err;
189 
190 	err = got_packidx_get_packfile_path(&path_packfile,
191 	    packidx->path_packidx);
192 	if (err)
193 		return err;
194 
195 	pack = got_repo_get_cached_pack(repo, path_packfile);
196 	if (pack == NULL) {
197 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
198 		if (err)
199 			goto done;
200 	}
201 
202 	err = read_packed_object_privsep(obj, repo, pack, packidx, idx, id);
203 	if (err)
204 		goto done;
205 done:
206 	free(path_packfile);
207 	return err;
208 }
209 
210 const struct got_error *
211 got_object_open_from_packfile(struct got_object **obj, struct got_object_id *id,
212     struct got_pack *pack, struct got_packidx *packidx, int obj_idx,
213     struct got_repository *repo)
214 {
215 	return read_packed_object_privsep(obj, repo, pack, packidx,
216 	    obj_idx, id);
217 }
218 
219 const struct got_error *
220 got_object_read_raw_delta(uint64_t *base_size, uint64_t *result_size,
221     off_t *delta_size, off_t *delta_compressed_size, off_t *delta_offset,
222     off_t *delta_out_offset, struct got_object_id **base_id, int delta_cache_fd,
223     struct got_packidx *packidx, int obj_idx, struct got_object_id *id,
224     struct got_repository *repo)
225 {
226 	const struct got_error *err = NULL;
227 	struct got_pack *pack = NULL;
228 	char *path_packfile;
229 
230 	*base_size = 0;
231 	*result_size = 0;
232 	*delta_size = 0;
233 	*delta_compressed_size = 0;
234 	*delta_offset = 0;
235 	*delta_out_offset = 0;
236 
237 	err = got_packidx_get_packfile_path(&path_packfile,
238 	    packidx->path_packidx);
239 	if (err)
240 		return err;
241 
242 	pack = got_repo_get_cached_pack(repo, path_packfile);
243 	if (pack == NULL) {
244 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
245 		if (err)
246 			return err;
247 	}
248 
249 	if (pack->privsep_child == NULL) {
250 		err = got_pack_start_privsep_child(pack, packidx);
251 		if (err)
252 			return err;
253 	}
254 
255 	if (!pack->child_has_delta_outfd) {
256 		int outfd_child;
257 		outfd_child = dup(delta_cache_fd);
258 		if (outfd_child == -1)
259 			return got_error_from_errno("dup");
260 		err = got_privsep_send_raw_delta_outfd(
261 		    pack->privsep_child->ibuf, outfd_child);
262 		if (err)
263 			return err;
264 		pack->child_has_delta_outfd = 1;
265 	}
266 
267 	err = got_privsep_send_raw_delta_req(pack->privsep_child->ibuf,
268 	    obj_idx, id);
269 	if (err)
270 		return err;
271 
272 	return got_privsep_recv_raw_delta(base_size, result_size, delta_size,
273 	    delta_compressed_size, delta_offset, delta_out_offset, base_id,
274 	    pack->privsep_child->ibuf);
275 }
276 
277 static const struct got_error *
278 request_object(struct got_object **obj, struct got_object_id *id,
279     struct got_repository *repo, int fd)
280 {
281 	const struct got_error *err = NULL;
282 	struct imsgbuf *ibuf;
283 
284 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf;
285 
286 	err = got_privsep_send_obj_req(ibuf, fd, id);
287 	if (err)
288 		return err;
289 
290 	return got_privsep_recv_obj(obj, ibuf);
291 }
292 
293 static const struct got_error *
294 request_raw_object(uint8_t **outbuf, off_t *size, size_t *hdrlen, int outfd,
295     struct got_object_id *id, struct got_repository *repo, int infd)
296 {
297 	const struct got_error *err = NULL;
298 	struct imsgbuf *ibuf;
299 	int outfd_child;
300 
301 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].ibuf;
302 
303 	outfd_child = dup(outfd);
304 	if (outfd_child == -1)
305 		return got_error_from_errno("dup");
306 
307 	err = got_privsep_send_raw_obj_req(ibuf, infd, id);
308 	if (err)
309 		return err;
310 
311 	err = got_privsep_send_raw_obj_outfd(ibuf, outfd_child);
312 	if (err)
313 		return err;
314 
315 	return got_privsep_recv_raw_obj(outbuf, size, hdrlen, ibuf);
316 }
317 
318 static const struct got_error *
319 start_child(struct got_repository *repo, int type)
320 {
321 	const struct got_error *err = NULL;
322 	int imsg_fds[2];
323 	pid_t pid;
324 	struct imsgbuf *ibuf;
325 	const char *prog_path;
326 
327 	switch (type) {
328 	case GOT_REPO_PRIVSEP_CHILD_OBJECT:
329 		prog_path = GOT_PATH_PROG_READ_OBJECT;
330 		break;
331 	case GOT_REPO_PRIVSEP_CHILD_TREE:
332 		prog_path = GOT_PATH_PROG_READ_TREE;
333 		break;
334 	case GOT_REPO_PRIVSEP_CHILD_COMMIT:
335 		prog_path = GOT_PATH_PROG_READ_COMMIT;
336 		break;
337 	case GOT_REPO_PRIVSEP_CHILD_BLOB:
338 		prog_path = GOT_PATH_PROG_READ_BLOB;
339 		break;
340 	case GOT_REPO_PRIVSEP_CHILD_TAG:
341 		prog_path = GOT_PATH_PROG_READ_TAG;
342 		break;
343 	default:
344 		return got_error(GOT_ERR_OBJ_TYPE);
345 	}
346 
347 	ibuf = calloc(1, sizeof(*ibuf));
348 	if (ibuf == NULL)
349 		return got_error_from_errno("calloc");
350 
351 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
352 		err = got_error_from_errno("socketpair");
353 		free(ibuf);
354 		return err;
355 	}
356 
357 	pid = fork();
358 	if (pid == -1) {
359 		err = got_error_from_errno("fork");
360 		free(ibuf);
361 		return err;
362 	}
363 	else if (pid == 0) {
364 		got_privsep_exec_child(imsg_fds, prog_path, repo->path);
365 		/* not reached */
366 	}
367 
368 	if (close(imsg_fds[1]) == -1) {
369 		err = got_error_from_errno("close");
370 		free(ibuf);
371 		return err;
372 	}
373 
374 	repo->privsep_children[type].imsg_fd = imsg_fds[0];
375 	repo->privsep_children[type].pid = pid;
376 	imsg_init(ibuf, imsg_fds[0]);
377 	repo->privsep_children[type].ibuf = ibuf;
378 
379 	return NULL;
380 }
381 
382 const struct got_error *
383 got_object_read_header_privsep(struct got_object **obj,
384     struct got_object_id *id, struct got_repository *repo, int obj_fd)
385 {
386 	const struct got_error *err;
387 
388 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd != -1)
389 		return request_object(obj, id, repo, obj_fd);
390 
391 	err = start_child(repo, GOT_REPO_PRIVSEP_CHILD_OBJECT);
392 	if (err)
393 		return err;
394 
395 	return request_object(obj, id, repo, obj_fd);
396 }
397 
398 static const struct got_error *
399 read_object_raw_privsep(uint8_t **outbuf, off_t *size, size_t *hdrlen,
400     int outfd, struct got_object_id *id, struct got_repository *repo,
401     int obj_fd)
402 {
403 	const struct got_error *err;
404 
405 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_OBJECT].imsg_fd != -1)
406 		return request_raw_object(outbuf, size, hdrlen, outfd, id,
407 		    repo, obj_fd);
408 
409 	err = start_child(repo, GOT_REPO_PRIVSEP_CHILD_OBJECT);
410 	if (err)
411 		return err;
412 
413 	return request_raw_object(outbuf, size, hdrlen, outfd, id, repo,
414 	    obj_fd);
415 }
416 
417 const struct got_error *
418 got_object_open(struct got_object **obj, struct got_repository *repo,
419     struct got_object_id *id)
420 {
421 	const struct got_error *err = NULL;
422 	int fd;
423 
424 	*obj = got_repo_get_cached_object(repo, id);
425 	if (*obj != NULL) {
426 		(*obj)->refcnt++;
427 		return NULL;
428 	}
429 
430 	err = got_object_open_packed(obj, id, repo);
431 	if (err && err->code != GOT_ERR_NO_OBJ)
432 		return err;
433 	if (*obj) {
434 		(*obj)->refcnt++;
435 		return got_repo_cache_object(repo, id, *obj);
436 	}
437 
438 	err = got_object_open_loose_fd(&fd, id, repo);
439 	if (err) {
440 		if (err->code == GOT_ERR_ERRNO && errno == ENOENT)
441 			err = got_error_no_obj(id);
442 		return err;
443 	}
444 
445 	err = got_object_read_header_privsep(obj, id, repo, fd);
446 	if (err)
447 		return err;
448 
449 	memcpy((*obj)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
450 
451 	(*obj)->refcnt++;
452 	return got_repo_cache_object(repo, id, *obj);
453 }
454 
455 /* *outfd must be initialized to -1 by caller */
456 const struct got_error *
457 got_object_raw_open(struct got_raw_object **obj, int *outfd,
458     struct got_repository *repo, struct got_object_id *id)
459 {
460 	const struct got_error *err = NULL;
461 	struct got_packidx *packidx = NULL;
462 	int idx;
463 	uint8_t *outbuf = NULL;
464 	off_t size = 0;
465 	size_t hdrlen = 0;
466 	char *path_packfile = NULL;
467 
468 	*obj = got_repo_get_cached_raw_object(repo, id);
469 	if (*obj != NULL) {
470 		(*obj)->refcnt++;
471 		return NULL;
472 	}
473 
474 	if (*outfd == -1) {
475 		*outfd = got_opentempfd();
476 		if (*outfd == -1)
477 			return got_error_from_errno("got_opentempfd");
478 	}
479 
480 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
481 	if (err == NULL) {
482 		struct got_pack *pack = NULL;
483 
484 		err = got_packidx_get_packfile_path(&path_packfile,
485 		    packidx->path_packidx);
486 		if (err)
487 			goto done;
488 
489 		pack = got_repo_get_cached_pack(repo, path_packfile);
490 		if (pack == NULL) {
491 			err = got_repo_cache_pack(&pack, repo, path_packfile,
492 			    packidx);
493 			if (err)
494 				goto done;
495 		}
496 		err = read_packed_object_raw_privsep(&outbuf, &size, &hdrlen,
497 		    *outfd, pack, packidx, idx, id);
498 		if (err)
499 			goto done;
500 	} else if (err->code == GOT_ERR_NO_OBJ) {
501 		int fd;
502 
503 		err = got_object_open_loose_fd(&fd, id, repo);
504 		if (err)
505 			goto done;
506 		err = read_object_raw_privsep(&outbuf, &size, &hdrlen, *outfd,
507 		    id, repo, fd);
508 		if (err)
509 			goto done;
510 	}
511 
512 	err = got_object_raw_alloc(obj, outbuf, outfd, hdrlen, size);
513 	if (err)
514 		goto done;
515 
516 	err = got_repo_cache_raw_object(repo, id, *obj);
517 done:
518 	free(path_packfile);
519 	if (err) {
520 		if (*obj) {
521 			got_object_raw_close(*obj);
522 			*obj = NULL;
523 		}
524 		free(outbuf);
525 	} else
526 		(*obj)->refcnt++;
527 	return err;
528 }
529 
530 static const struct got_error *
531 request_packed_commit(struct got_commit_object **commit, struct got_pack *pack,
532     int pack_idx, struct got_object_id *id)
533 {
534 	const struct got_error *err = NULL;
535 
536 	err = got_privsep_send_commit_req(pack->privsep_child->ibuf, -1, id,
537 	    pack_idx);
538 	if (err)
539 		return err;
540 
541 	err = got_privsep_recv_commit(commit, pack->privsep_child->ibuf);
542 	if (err)
543 		return err;
544 
545 	(*commit)->flags |= GOT_COMMIT_FLAG_PACKED;
546 	return NULL;
547 }
548 
549 static const struct got_error *
550 read_packed_commit_privsep(struct got_commit_object **commit,
551     struct got_pack *pack, struct got_packidx *packidx, int idx,
552     struct got_object_id *id)
553 {
554 	const struct got_error *err = NULL;
555 
556 	if (pack->privsep_child)
557 		return request_packed_commit(commit, pack, idx, id);
558 
559 	err = got_pack_start_privsep_child(pack, packidx);
560 	if (err)
561 		return err;
562 
563 	return request_packed_commit(commit, pack, idx, id);
564 }
565 
566 static const struct got_error *
567 request_commit(struct got_commit_object **commit, struct got_repository *repo,
568     int fd, struct got_object_id *id)
569 {
570 	const struct got_error *err = NULL;
571 	struct imsgbuf *ibuf;
572 
573 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].ibuf;
574 
575 	err = got_privsep_send_commit_req(ibuf, fd, id, -1);
576 	if (err)
577 		return err;
578 
579 	return got_privsep_recv_commit(commit, ibuf);
580 }
581 
582 static const struct got_error *
583 read_commit_privsep(struct got_commit_object **commit, int obj_fd,
584     struct got_object_id *id, struct got_repository *repo)
585 {
586 	const struct got_error *err;
587 
588 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_COMMIT].imsg_fd != -1)
589 		return request_commit(commit, repo, obj_fd, id);
590 
591 	err = start_child(repo, GOT_REPO_PRIVSEP_CHILD_COMMIT);
592 	if (err)
593 		return err;
594 
595 	return request_commit(commit, repo, obj_fd, id);
596 }
597 
598 static const struct got_error *
599 open_commit(struct got_commit_object **commit,
600     struct got_repository *repo, struct got_object_id *id, int check_cache)
601 {
602 	const struct got_error *err = NULL;
603 	struct got_packidx *packidx = NULL;
604 	int idx;
605 	char *path_packfile = NULL;
606 
607 	if (check_cache) {
608 		*commit = got_repo_get_cached_commit(repo, id);
609 		if (*commit != NULL) {
610 			(*commit)->refcnt++;
611 			return NULL;
612 		}
613 	} else
614 		*commit = NULL;
615 
616 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
617 	if (err == NULL) {
618 		struct got_pack *pack = NULL;
619 
620 		err = got_packidx_get_packfile_path(&path_packfile,
621 		    packidx->path_packidx);
622 		if (err)
623 			return err;
624 
625 		pack = got_repo_get_cached_pack(repo, path_packfile);
626 		if (pack == NULL) {
627 			err = got_repo_cache_pack(&pack, repo, path_packfile,
628 			    packidx);
629 			if (err)
630 				goto done;
631 		}
632 		err = read_packed_commit_privsep(commit, pack,
633 		    packidx, idx, id);
634 	} else if (err->code == GOT_ERR_NO_OBJ) {
635 		int fd;
636 
637 		err = got_object_open_loose_fd(&fd, id, repo);
638 		if (err)
639 			return err;
640 		err = read_commit_privsep(commit, fd, id, repo);
641 	}
642 
643 	if (err == NULL) {
644 		(*commit)->refcnt++;
645 		err = got_repo_cache_commit(repo, id, *commit);
646 	}
647 done:
648 	free(path_packfile);
649 	return err;
650 }
651 
652 const struct got_error *
653 got_object_open_as_commit(struct got_commit_object **commit,
654     struct got_repository *repo, struct got_object_id *id)
655 {
656 	*commit = got_repo_get_cached_commit(repo, id);
657 	if (*commit != NULL) {
658 		(*commit)->refcnt++;
659 		return NULL;
660 	}
661 
662 	return open_commit(commit, repo, id, 0);
663 }
664 
665 const struct got_error *
666 got_object_commit_open(struct got_commit_object **commit,
667     struct got_repository *repo, struct got_object *obj)
668 {
669 	return open_commit(commit, repo, got_object_get_id(obj), 1);
670 }
671 
672 static const struct got_error *
673 request_packed_tree(struct got_tree_object **tree, struct got_pack *pack,
674     int pack_idx, struct got_object_id *id)
675 {
676 	const struct got_error *err = NULL;
677 
678 	err = got_privsep_send_tree_req(pack->privsep_child->ibuf, -1, id,
679 	    pack_idx);
680 	if (err)
681 		return err;
682 
683 	return got_privsep_recv_tree(tree, pack->privsep_child->ibuf);
684 }
685 
686 static const struct got_error *
687 read_packed_tree_privsep(struct got_tree_object **tree,
688     struct got_pack *pack, struct got_packidx *packidx, int idx,
689     struct got_object_id *id)
690 {
691 	const struct got_error *err = NULL;
692 
693 	if (pack->privsep_child)
694 		return request_packed_tree(tree, pack, idx, id);
695 
696 	err = got_pack_start_privsep_child(pack, packidx);
697 	if (err)
698 		return err;
699 
700 	return request_packed_tree(tree, pack, idx, id);
701 }
702 
703 static const struct got_error *
704 request_tree(struct got_tree_object **tree, struct got_repository *repo,
705     int fd, struct got_object_id *id)
706 {
707 	const struct got_error *err = NULL;
708 	struct imsgbuf *ibuf;
709 
710 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].ibuf;
711 
712 	err = got_privsep_send_tree_req(ibuf, fd, id, -1);
713 	if (err)
714 		return err;
715 
716 	return got_privsep_recv_tree(tree, ibuf);
717 }
718 
719 static const struct got_error *
720 read_tree_privsep(struct got_tree_object **tree, int obj_fd,
721     struct got_object_id *id, struct got_repository *repo)
722 {
723 	const struct got_error *err;
724 
725 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TREE].imsg_fd != -1)
726 		return request_tree(tree, repo, obj_fd, id);
727 
728 	err = start_child(repo, GOT_REPO_PRIVSEP_CHILD_TREE);
729 	if (err)
730 		return err;
731 
732 	return request_tree(tree, repo, obj_fd, id);
733 }
734 
735 static const struct got_error *
736 open_tree(struct got_tree_object **tree, struct got_repository *repo,
737     struct got_object_id *id, int check_cache)
738 {
739 	const struct got_error *err = NULL;
740 	struct got_packidx *packidx = NULL;
741 	int idx;
742 	char *path_packfile = NULL;
743 
744 	if (check_cache) {
745 		*tree = got_repo_get_cached_tree(repo, id);
746 		if (*tree != NULL) {
747 			(*tree)->refcnt++;
748 			return NULL;
749 		}
750 	} else
751 		*tree = NULL;
752 
753 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
754 	if (err == NULL) {
755 		struct got_pack *pack = NULL;
756 
757 		err = got_packidx_get_packfile_path(&path_packfile,
758 		    packidx->path_packidx);
759 		if (err)
760 			return err;
761 
762 		pack = got_repo_get_cached_pack(repo, path_packfile);
763 		if (pack == NULL) {
764 			err = got_repo_cache_pack(&pack, repo, path_packfile,
765 			    packidx);
766 			if (err)
767 				goto done;
768 		}
769 		err = read_packed_tree_privsep(tree, pack,
770 		    packidx, idx, id);
771 	} else if (err->code == GOT_ERR_NO_OBJ) {
772 		int fd;
773 
774 		err = got_object_open_loose_fd(&fd, id, repo);
775 		if (err)
776 			return err;
777 		err = read_tree_privsep(tree, fd, id, repo);
778 	}
779 
780 	if (err == NULL) {
781 		(*tree)->refcnt++;
782 		err = got_repo_cache_tree(repo, id, *tree);
783 	}
784 done:
785 	free(path_packfile);
786 	return err;
787 }
788 
789 const struct got_error *
790 got_object_open_as_tree(struct got_tree_object **tree,
791     struct got_repository *repo, struct got_object_id *id)
792 {
793 	*tree = got_repo_get_cached_tree(repo, id);
794 	if (*tree != NULL) {
795 		(*tree)->refcnt++;
796 		return NULL;
797 	}
798 
799 	return open_tree(tree, repo, id, 0);
800 }
801 
802 const struct got_error *
803 got_object_tree_open(struct got_tree_object **tree,
804     struct got_repository *repo, struct got_object *obj)
805 {
806 	return open_tree(tree, repo, got_object_get_id(obj), 1);
807 }
808 
809 static const struct got_error *
810 request_packed_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
811     struct got_pack *pack, struct got_packidx *packidx, int idx,
812     struct got_object_id *id)
813 {
814 	const struct got_error *err = NULL;
815 	struct imsgbuf *ibuf = pack->privsep_child->ibuf;
816 	int outfd_child;
817 
818 	 err = pack_child_send_tempfiles(ibuf, pack);
819 	 if (err)
820 		return err;
821 
822 	outfd_child = dup(outfd);
823 	if (outfd_child == -1)
824 		return got_error_from_errno("dup");
825 
826 	err = got_privsep_send_blob_req(pack->privsep_child->ibuf, -1, id, idx);
827 	if (err)
828 		return err;
829 
830 	err = got_privsep_send_blob_outfd(pack->privsep_child->ibuf,
831 	    outfd_child);
832 	if (err) {
833 		return err;
834 	}
835 
836 	err = got_privsep_recv_blob(outbuf, size, hdrlen,
837 	    pack->privsep_child->ibuf);
838 	if (err)
839 		return err;
840 
841 	if (lseek(outfd, SEEK_SET, 0) == -1)
842 		err = got_error_from_errno("lseek");
843 
844 	return err;
845 }
846 
847 static const struct got_error *
848 read_packed_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
849     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
850     struct got_object_id *id)
851 {
852 	const struct got_error *err = NULL;
853 
854 	if (pack->privsep_child == NULL) {
855 		err = got_pack_start_privsep_child(pack, packidx);
856 		if (err)
857 			return err;
858 	}
859 
860 	return request_packed_blob(outbuf, size, hdrlen, outfd, pack, packidx,
861 	    idx, id);
862 }
863 
864 static const struct got_error *
865 request_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen, int outfd,
866     int infd, struct got_object_id *id, struct imsgbuf *ibuf)
867 {
868 	const struct got_error *err = NULL;
869 	int outfd_child;
870 
871 	outfd_child = dup(outfd);
872 	if (outfd_child == -1)
873 		return got_error_from_errno("dup");
874 
875 	err = got_privsep_send_blob_req(ibuf, infd, id, -1);
876 	if (err)
877 		return err;
878 
879 	err = got_privsep_send_blob_outfd(ibuf, outfd_child);
880 	if (err)
881 		return err;
882 
883 	err = got_privsep_recv_blob(outbuf, size, hdrlen, ibuf);
884 	if (err)
885 		return err;
886 
887 	if (lseek(outfd, SEEK_SET, 0) == -1)
888 		return got_error_from_errno("lseek");
889 
890 	return err;
891 }
892 
893 static const struct got_error *
894 read_blob_privsep(uint8_t **outbuf, size_t *size, size_t *hdrlen,
895     int outfd, int infd, struct got_object_id *id, struct got_repository *repo)
896 {
897 	const struct got_error *err;
898 	struct imsgbuf *ibuf;
899 
900 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].imsg_fd != -1) {
901 		ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf;
902 		return request_blob(outbuf, size, hdrlen, outfd, infd, id,
903 		    ibuf);
904 	}
905 
906 	err = start_child(repo, GOT_REPO_PRIVSEP_CHILD_BLOB);
907 	if (err)
908 		return err;
909 
910 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_BLOB].ibuf;
911 	return request_blob(outbuf, size, hdrlen, outfd, infd, id, ibuf);
912 }
913 
914 static const struct got_error *
915 open_blob(struct got_blob_object **blob, struct got_repository *repo,
916     struct got_object_id *id, size_t blocksize, int outfd)
917 {
918 	const struct got_error *err = NULL;
919 	struct got_packidx *packidx = NULL;
920 	int idx, dfd = -1;
921 	char *path_packfile = NULL;
922 	uint8_t *outbuf;
923 	size_t size, hdrlen;
924 	struct stat sb;
925 
926 	*blob = calloc(1, sizeof(**blob));
927 	if (*blob == NULL)
928 		return got_error_from_errno("calloc");
929 
930 	(*blob)->read_buf = malloc(blocksize);
931 	if ((*blob)->read_buf == NULL) {
932 		err = got_error_from_errno("malloc");
933 		goto done;
934 	}
935 
936 	if (ftruncate(outfd, 0L) == -1) {
937 		err = got_error_from_errno("ftruncate");
938 		goto done;
939 	}
940 	if (lseek(outfd, SEEK_SET, 0) == -1) {
941 		err = got_error_from_errno("lseek");
942 		goto done;
943 	}
944 
945 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
946 	if (err == NULL) {
947 		struct got_pack *pack = NULL;
948 
949 		err = got_packidx_get_packfile_path(&path_packfile,
950 		    packidx->path_packidx);
951 		if (err)
952 			goto done;
953 
954 		pack = got_repo_get_cached_pack(repo, path_packfile);
955 		if (pack == NULL) {
956 			err = got_repo_cache_pack(&pack, repo, path_packfile,
957 			    packidx);
958 			if (err)
959 				goto done;
960 		}
961 		err = read_packed_blob_privsep(&outbuf, &size, &hdrlen, outfd,
962 		    pack, packidx, idx, id);
963 	} else if (err->code == GOT_ERR_NO_OBJ) {
964 		int infd;
965 
966 		err = got_object_open_loose_fd(&infd, id, repo);
967 		if (err)
968 			goto done;
969 		err = read_blob_privsep(&outbuf, &size, &hdrlen, outfd, infd,
970 		    id, repo);
971 	}
972 	if (err)
973 		goto done;
974 
975 	if (hdrlen > size) {
976 		err = got_error(GOT_ERR_BAD_OBJ_HDR);
977 		goto done;
978 	}
979 
980 	if (outbuf) {
981 		(*blob)->f = fmemopen(outbuf, size, "rb");
982 		if ((*blob)->f == NULL) {
983 			err = got_error_from_errno("fmemopen");
984 			free(outbuf);
985 			goto done;
986 		}
987 		(*blob)->data = outbuf;
988 	} else {
989 		if (fstat(outfd, &sb) == -1) {
990 			err = got_error_from_errno("fstat");
991 			goto done;
992 		}
993 
994 		if (sb.st_size != size) {
995 			err = got_error(GOT_ERR_PRIVSEP_LEN);
996 			goto done;
997 		}
998 
999 		dfd = dup(outfd);
1000 		if (dfd == -1) {
1001 			err = got_error_from_errno("dup");
1002 			goto done;
1003 		}
1004 
1005 		(*blob)->f = fdopen(dfd, "rb");
1006 		if ((*blob)->f == NULL) {
1007 			err = got_error_from_errno("fdopen");
1008 			close(dfd);
1009 			dfd = -1;
1010 			goto done;
1011 		}
1012 	}
1013 
1014 	(*blob)->hdrlen = hdrlen;
1015 	(*blob)->blocksize = blocksize;
1016 	memcpy(&(*blob)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
1017 
1018 done:
1019 	free(path_packfile);
1020 	if (err) {
1021 		if (*blob) {
1022 			got_object_blob_close(*blob);
1023 			*blob = NULL;
1024 		}
1025 	}
1026 	return err;
1027 }
1028 
1029 const struct got_error *
1030 got_object_open_as_blob(struct got_blob_object **blob,
1031     struct got_repository *repo, struct got_object_id *id, size_t blocksize,
1032     int outfd)
1033 {
1034 	return open_blob(blob, repo, id, blocksize, outfd);
1035 }
1036 
1037 const struct got_error *
1038 got_object_blob_open(struct got_blob_object **blob,
1039     struct got_repository *repo, struct got_object *obj, size_t blocksize,
1040     int outfd)
1041 {
1042 	return open_blob(blob, repo, got_object_get_id(obj), blocksize, outfd);
1043 }
1044 
1045 static const struct got_error *
1046 request_packed_tag(struct got_tag_object **tag, struct got_pack *pack,
1047     int pack_idx, struct got_object_id *id)
1048 {
1049 	const struct got_error *err = NULL;
1050 
1051 	err = got_privsep_send_tag_req(pack->privsep_child->ibuf, -1, id,
1052 	    pack_idx);
1053 	if (err)
1054 		return err;
1055 
1056 	return got_privsep_recv_tag(tag, pack->privsep_child->ibuf);
1057 }
1058 
1059 static const struct got_error *
1060 read_packed_tag_privsep(struct got_tag_object **tag,
1061     struct got_pack *pack, struct got_packidx *packidx, int idx,
1062     struct got_object_id *id)
1063 {
1064 	const struct got_error *err = NULL;
1065 
1066 	if (pack->privsep_child)
1067 		return request_packed_tag(tag, pack, idx, id);
1068 
1069 	err = got_pack_start_privsep_child(pack, packidx);
1070 	if (err)
1071 		return err;
1072 
1073 	return request_packed_tag(tag, pack, idx, id);
1074 }
1075 
1076 static const struct got_error *
1077 request_tag(struct got_tag_object **tag, struct got_repository *repo,
1078     int fd, struct got_object_id *id)
1079 {
1080 	const struct got_error *err = NULL;
1081 	struct imsgbuf *ibuf;
1082 
1083 	ibuf = repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].ibuf;
1084 
1085 	err = got_privsep_send_tag_req(ibuf, fd, id, -1);
1086 	if (err)
1087 		return err;
1088 
1089 	return got_privsep_recv_tag(tag, ibuf);
1090 }
1091 
1092 static const struct got_error *
1093 read_tag_privsep(struct got_tag_object **tag, int obj_fd,
1094     struct got_object_id *id, struct got_repository *repo)
1095 {
1096 	const struct got_error *err;
1097 
1098 	if (repo->privsep_children[GOT_REPO_PRIVSEP_CHILD_TAG].imsg_fd != -1)
1099 		return request_tag(tag, repo, obj_fd, id);
1100 
1101 	err = start_child(repo, GOT_REPO_PRIVSEP_CHILD_TAG);
1102 	if (err)
1103 		return err;
1104 
1105 	return request_tag(tag, repo, obj_fd, id);
1106 }
1107 
1108 static const struct got_error *
1109 open_tag(struct got_tag_object **tag, struct got_repository *repo,
1110     struct got_object_id *id, int check_cache)
1111 {
1112 	const struct got_error *err = NULL;
1113 	struct got_packidx *packidx = NULL;
1114 	int idx;
1115 	char *path_packfile = NULL;
1116 	struct got_object *obj = NULL;
1117 	int obj_type = GOT_OBJ_TYPE_ANY;
1118 
1119 	if (check_cache) {
1120 		*tag = got_repo_get_cached_tag(repo, id);
1121 		if (*tag != NULL) {
1122 			(*tag)->refcnt++;
1123 			return NULL;
1124 		}
1125 	} else
1126 		*tag = NULL;
1127 
1128 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
1129 	if (err == NULL) {
1130 		struct got_pack *pack = NULL;
1131 
1132 		err = got_packidx_get_packfile_path(&path_packfile,
1133 		    packidx->path_packidx);
1134 		if (err)
1135 			return err;
1136 
1137 		pack = got_repo_get_cached_pack(repo, path_packfile);
1138 		if (pack == NULL) {
1139 			err = got_repo_cache_pack(&pack, repo, path_packfile,
1140 			    packidx);
1141 			if (err)
1142 				goto done;
1143 		}
1144 
1145 		/* Beware of "lightweight" tags: Check object type first. */
1146 		err = read_packed_object_privsep(&obj, repo, pack, packidx,
1147 		    idx, id);
1148 		if (err)
1149 			goto done;
1150 		obj_type = obj->type;
1151 		got_object_close(obj);
1152 		if (obj_type != GOT_OBJ_TYPE_TAG) {
1153 			err = got_error(GOT_ERR_OBJ_TYPE);
1154 			goto done;
1155 		}
1156 		err = read_packed_tag_privsep(tag, pack, packidx, idx, id);
1157 	} else if (err->code == GOT_ERR_NO_OBJ) {
1158 		int fd;
1159 
1160 		err = got_object_open_loose_fd(&fd, id, repo);
1161 		if (err)
1162 			return err;
1163 		err = got_object_read_header_privsep(&obj, id, repo, fd);
1164 		if (err)
1165 			return err;
1166 		obj_type = obj->type;
1167 		got_object_close(obj);
1168 		if (obj_type != GOT_OBJ_TYPE_TAG)
1169 			return got_error(GOT_ERR_OBJ_TYPE);
1170 
1171 		err = got_object_open_loose_fd(&fd, id, repo);
1172 		if (err)
1173 			return err;
1174 		err = read_tag_privsep(tag, fd, id, repo);
1175 	}
1176 
1177 	if (err == NULL) {
1178 		(*tag)->refcnt++;
1179 		err = got_repo_cache_tag(repo, id, *tag);
1180 	}
1181 done:
1182 	free(path_packfile);
1183 	return err;
1184 }
1185 
1186 const struct got_error *
1187 got_object_open_as_tag(struct got_tag_object **tag,
1188     struct got_repository *repo, struct got_object_id *id)
1189 {
1190 	*tag = got_repo_get_cached_tag(repo, id);
1191 	if (*tag != NULL) {
1192 		(*tag)->refcnt++;
1193 		return NULL;
1194 	}
1195 
1196 	return open_tag(tag, repo, id, 0);
1197 }
1198 
1199 const struct got_error *
1200 got_object_tag_open(struct got_tag_object **tag,
1201     struct got_repository *repo, struct got_object *obj)
1202 {
1203 	return open_tag(tag, repo, got_object_get_id(obj), 1);
1204 }
1205 
1206 const struct got_error *
1207 got_traverse_packed_commits(struct got_object_id_queue *traversed_commits,
1208     struct got_object_id *commit_id, const char *path,
1209     struct got_repository *repo)
1210 {
1211 	const struct got_error *err = NULL;
1212 	struct got_pack *pack = NULL;
1213 	struct got_packidx *packidx = NULL;
1214 	char *path_packfile = NULL;
1215 	struct got_commit_object *changed_commit = NULL;
1216 	struct got_object_id *changed_commit_id = NULL;
1217 	int idx;
1218 
1219 	err = got_repo_search_packidx(&packidx, &idx, repo, commit_id);
1220 	if (err) {
1221 		if (err->code != GOT_ERR_NO_OBJ)
1222 			return err;
1223 		return NULL;
1224 	}
1225 
1226 	err = got_packidx_get_packfile_path(&path_packfile,
1227 	    packidx->path_packidx);
1228 	if (err)
1229 		return err;
1230 
1231 	pack = got_repo_get_cached_pack(repo, path_packfile);
1232 	if (pack == NULL) {
1233 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
1234 		if (err)
1235 			goto done;
1236 	}
1237 
1238 	if (pack->privsep_child == NULL) {
1239 		err = got_pack_start_privsep_child(pack, packidx);
1240 		if (err)
1241 			goto done;
1242 	}
1243 
1244 	err = got_privsep_send_commit_traversal_request(
1245 	    pack->privsep_child->ibuf, commit_id, idx, path);
1246 	if (err)
1247 		goto done;
1248 
1249 	err = got_privsep_recv_traversed_commits(&changed_commit,
1250 	    &changed_commit_id, traversed_commits, pack->privsep_child->ibuf);
1251 	if (err)
1252 		goto done;
1253 
1254 	if (changed_commit) {
1255 		/*
1256 		 * Cache the commit in which the path was changed.
1257 		 * This commit might be opened again soon.
1258 		 */
1259 		changed_commit->refcnt++;
1260 		err = got_repo_cache_commit(repo, changed_commit_id,
1261 		    changed_commit);
1262 		got_object_commit_close(changed_commit);
1263 	}
1264 done:
1265 	free(path_packfile);
1266 	free(changed_commit_id);
1267 	return err;
1268 }
1269 
1270 const struct got_error *
1271 got_object_enumerate(int *found_all_objects,
1272     got_object_enumerate_commit_cb cb_commit,
1273     got_object_enumerate_tree_cb cb_tree, void *cb_arg,
1274     struct got_object_id **ours, int nours,
1275     struct got_object_id **theirs, int ntheirs,
1276     struct got_packidx *packidx, struct got_repository *repo)
1277 {
1278 	const struct got_error *err = NULL;
1279 	struct got_pack *pack;
1280 	char *path_packfile = NULL;
1281 
1282 	err = got_packidx_get_packfile_path(&path_packfile,
1283 	    packidx->path_packidx);
1284 	if (err)
1285 		return err;
1286 
1287 	pack = got_repo_get_cached_pack(repo, path_packfile);
1288 	if (pack == NULL) {
1289 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
1290 		if (err)
1291 			goto done;
1292 	}
1293 
1294 	if (pack->privsep_child == NULL) {
1295 		err = got_pack_start_privsep_child(pack, packidx);
1296 		if (err)
1297 			goto done;
1298 	}
1299 
1300 	err = got_privsep_send_object_enumeration_request(
1301 	    pack->privsep_child->ibuf);
1302 	if (err)
1303 		goto done;
1304 
1305 	err = got_privsep_send_object_idlist(pack->privsep_child->ibuf,
1306 	    ours, nours);
1307 	if (err)
1308 		goto done;
1309 	err = got_privsep_send_object_idlist_done(pack->privsep_child->ibuf);
1310 	if (err)
1311 		goto done;
1312 
1313 	err = got_privsep_send_object_idlist(pack->privsep_child->ibuf,
1314 	    theirs, ntheirs);
1315 	if (err)
1316 		goto done;
1317 	err = got_privsep_send_object_idlist_done(pack->privsep_child->ibuf);
1318 	if (err)
1319 		goto done;
1320 
1321 	err = got_privsep_recv_enumerated_objects(found_all_objects,
1322 	    pack->privsep_child->ibuf, cb_commit, cb_tree, cb_arg, repo);
1323 done:
1324 	free(path_packfile);
1325 	return err;
1326 }