Gotweb

Blob

Date:: Fri Jun 22 09:45:31 2018 UTC
Message:: fix mem leak introduced with caching: actually close objects
Actions:: History | Blame | Raw File
1 /*
2  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <sys/stat.h>
19 #include <sys/queue.h>
20 #include <sys/uio.h>
21 #include <sys/socket.h>
22 #include <sys/wait.h>
23 
24 #include <errno.h>
25 #include <fcntl.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <stdint.h>
30 #include <sha1.h>
31 #include <zlib.h>
32 #include <ctype.h>
33 #include <limits.h>
34 #include <imsg.h>
35 #include <time.h>
36 
37 #include "got_error.h"
38 #include "got_object.h"
39 #include "got_repository.h"
40 #include "got_opentemp.h"
41 
42 #include "got_lib_sha1.h"
43 #include "got_lib_delta.h"
44 #include "got_lib_pack.h"
45 #include "got_lib_path.h"
46 #include "got_lib_zbuf.h"
47 #include "got_lib_object.h"
48 #include "got_lib_privsep.h"
49 #include "got_lib_repository.h"
50 
51 #ifndef MIN
52 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
53 #endif
54 
55 #ifndef nitems
56 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
57 #endif
58 
59 #define GOT_OBJ_TAG_COMMIT	"commit"
60 #define GOT_OBJ_TAG_TREE	"tree"
61 #define GOT_OBJ_TAG_BLOB	"blob"
62 
63 #define GOT_COMMIT_TAG_TREE		"tree "
64 #define GOT_COMMIT_TAG_PARENT		"parent "
65 #define GOT_COMMIT_TAG_AUTHOR		"author "
66 #define GOT_COMMIT_TAG_COMMITTER	"committer "
67 
68 const struct got_error *
69 got_object_id_str(char **outbuf, struct got_object_id *id)
70 {
71 	static const size_t len = SHA1_DIGEST_STRING_LENGTH;
72 
73 	*outbuf = calloc(1, len);
74 	if (*outbuf == NULL)
75 		return got_error_from_errno();
76 
77 	if (got_sha1_digest_to_str(id->sha1, *outbuf, len) == NULL) {
78 		free(*outbuf);
79 		*outbuf = NULL;
80 		return got_error(GOT_ERR_BAD_OBJ_ID_STR);
81 	}
82 
83 	return NULL;
84 }
85 
86 int
87 got_object_id_cmp(struct got_object_id *id1, struct got_object_id *id2)
88 {
89 	return memcmp(id1->sha1, id2->sha1, SHA1_DIGEST_LENGTH);
90 }
91 
92 struct got_object_id *
93 got_object_id_dup(struct got_object_id *id1)
94 {
95 	struct got_object_id *id2;
96 
97 	id2 = malloc(sizeof(*id2));
98 	if (id2 == NULL)
99 		return NULL;
100 	memcpy(id2, id1, sizeof(*id2));
101 	return id2;
102 }
103 
104 struct got_object_id *
105 got_object_get_id(struct got_object *obj)
106 {
107 	return got_object_id_dup(&obj->id);
108 }
109 
110 const struct got_error *
111 got_object_get_id_str(char **outbuf, struct got_object *obj)
112 {
113 	return got_object_id_str(outbuf, &obj->id);
114 }
115 
116 int
117 got_object_get_type(struct got_object *obj)
118 {
119 	switch (obj->type) {
120 	case GOT_OBJ_TYPE_COMMIT:
121 	case GOT_OBJ_TYPE_TREE:
122 	case GOT_OBJ_TYPE_BLOB:
123 	case GOT_OBJ_TYPE_TAG:
124 		return obj->type;
125 	default:
126 		abort();
127 		break;
128 	}
129 
130 	/* not reached */
131 	return 0;
132 }
133 
134 static const struct got_error *
135 parse_object_header(struct got_object **obj, char *buf, size_t len)
136 {
137 	const char *obj_tags[] = {
138 		GOT_OBJ_TAG_COMMIT,
139 		GOT_OBJ_TAG_TREE,
140 		GOT_OBJ_TAG_BLOB
141 	};
142 	const int obj_types[] = {
143 		GOT_OBJ_TYPE_COMMIT,
144 		GOT_OBJ_TYPE_TREE,
145 		GOT_OBJ_TYPE_BLOB,
146 	};
147 	int type = 0;
148 	size_t size = 0, hdrlen = 0;
149 	int i;
150 	char *p = strchr(buf, '\0');
151 
152 	if (p == NULL)
153 		return got_error(GOT_ERR_BAD_OBJ_HDR);
154 
155 	hdrlen = strlen(buf) + 1 /* '\0' */;
156 
157 	for (i = 0; i < nitems(obj_tags); i++) {
158 		const char *tag = obj_tags[i];
159 		size_t tlen = strlen(tag);
160 		const char *errstr;
161 
162 		if (strncmp(buf, tag, tlen) != 0)
163 			continue;
164 
165 		type = obj_types[i];
166 		if (len <= tlen)
167 			return got_error(GOT_ERR_BAD_OBJ_HDR);
168 		size = strtonum(buf + tlen, 0, LONG_MAX, &errstr);
169 		if (errstr != NULL)
170 			return got_error(GOT_ERR_BAD_OBJ_HDR);
171 		break;
172 	}
173 
174 	if (type == 0)
175 		return got_error(GOT_ERR_BAD_OBJ_HDR);
176 
177 	*obj = calloc(1, sizeof(**obj));
178 	if (*obj == NULL)
179 		return got_error_from_errno();
180 	(*obj)->type = type;
181 	(*obj)->hdrlen = hdrlen;
182 	(*obj)->size = size;
183 	return NULL;
184 }
185 
186 static const struct got_error *
187 read_object_header(struct got_object **obj, FILE *f)
188 {
189 	const struct got_error *err;
190 	struct got_zstream_buf zb;
191 	char *buf;
192 	const size_t zbsize = 64;
193 	size_t outlen, totlen;
194 	int i;
195 
196 	buf = calloc(zbsize, sizeof(char));
197 	if (buf == NULL)
198 		return got_error_from_errno();
199 
200 	err = got_inflate_init(&zb, NULL, zbsize);
201 	if (err)
202 		return err;
203 
204 	i = 0;
205 	totlen = 0;
206 	do {
207 		err = got_inflate_read(&zb, f, &outlen);
208 		if (err)
209 			goto done;
210 		if (strchr(zb.outbuf, '\0') == NULL) {
211 			buf = recallocarray(buf, 1 + i, 2 + i, zbsize);
212 			if (buf == NULL) {
213 				err = got_error_from_errno();
214 				goto done;
215 			}
216 		}
217 		memcpy(buf + totlen, zb.outbuf, outlen);
218 		totlen += outlen;
219 		i++;
220 	} while (strchr(zb.outbuf, '\0') == NULL);
221 
222 	err = parse_object_header(obj, buf, totlen);
223 done:
224 	got_inflate_end(&zb);
225 	return err;
226 }
227 
228 static void
229 read_object_header_privsep_child(int obj_fd, int imsg_fds[2])
230 {
231 	const struct got_error *err = NULL;
232 	struct got_object *obj = NULL;
233 	struct imsgbuf ibuf;
234 	FILE *f = NULL;
235 	int status = 0;
236 
237 	setproctitle("read object header");
238 	close(imsg_fds[0]);
239 	imsg_init(&ibuf, imsg_fds[1]);
240 
241 	/* revoke access to most system calls */
242 	if (pledge("stdio", NULL) == -1) {
243 		err = got_error_from_errno();
244 		goto done;
245 	}
246 
247 	f = fdopen(obj_fd, "rb");
248 	if (f == NULL) {
249 		err = got_error_from_errno();
250 		close(obj_fd);
251 		goto done;
252 	}
253 
254 	err = read_object_header(&obj, f);
255 	if (err)
256 		goto done;
257 
258 	err = got_privsep_send_obj(&ibuf, obj, 0);
259 done:
260 	if (obj)
261 		got_object_close(obj);
262 	if (err) {
263 		got_privsep_send_error(&ibuf, err);
264 		status = 1;
265 	}
266 	if (f)
267 		fclose(f);
268 	imsg_clear(&ibuf);
269 	close(imsg_fds[1]);
270 	_exit(status);
271 }
272 
273 static const struct got_error *
274 wait_for_child(pid_t pid)
275 {
276 	int child_status;
277 
278 	waitpid(pid, &child_status, 0);
279 
280 	if (!WIFEXITED(child_status))
281 		return got_error(GOT_ERR_PRIVSEP_DIED);
282 
283 	if (WEXITSTATUS(child_status) != 0)
284 		return got_error(GOT_ERR_PRIVSEP_EXIT);
285 
286 	return NULL;
287 }
288 
289 static const struct got_error *
290 read_object_header_privsep(struct got_object **obj, int fd)
291 {
292 	struct imsgbuf parent_ibuf;
293 	int imsg_fds[2];
294 	const struct got_error *err = NULL, *err_child = NULL;
295 	pid_t pid;
296 
297 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1)
298 		return got_error_from_errno();
299 
300 	pid = fork();
301 	if (pid == -1)
302 		return got_error_from_errno();
303 	else if (pid == 0) {
304 		read_object_header_privsep_child(fd, imsg_fds);
305 		/* not reached */
306 	}
307 
308 	close(imsg_fds[1]);
309 	imsg_init(&parent_ibuf, imsg_fds[0]);
310 	err = got_privsep_recv_obj(obj, &parent_ibuf);
311 	imsg_clear(&parent_ibuf);
312 	err_child = wait_for_child(pid);
313 	close(imsg_fds[0]);
314 	return err ? err : err_child;
315 }
316 
317 static const struct got_error *
318 object_path(char **path, struct got_object_id *id, struct got_repository *repo)
319 {
320 	const struct got_error *err = NULL;
321 	char *hex;
322 	char *path_objects = got_repo_get_path_objects(repo);
323 
324 	*path = NULL;
325 
326 	if (path_objects == NULL)
327 		return got_error_from_errno();
328 
329 	err = got_object_id_str(&hex, id);
330 	if (err)
331 		return err;
332 
333 	if (asprintf(path, "%s/%.2x/%s", path_objects,
334 	    id->sha1[0], hex + 2) == -1)
335 		err = got_error_from_errno();
336 
337 	free(hex);
338 	free(path_objects);
339 	return err;
340 }
341 
342 static const struct got_error *
343 open_loose_object(int *fd, struct got_object *obj, struct got_repository *repo)
344 {
345 	const struct got_error *err = NULL;
346 	char *path;
347 
348 	err = object_path(&path, &obj->id, repo);
349 	if (err)
350 		return err;
351 	*fd = open(path, O_RDONLY | O_NOFOLLOW, GOT_DEFAULT_FILE_MODE);
352 	if (*fd == -1) {
353 		err = got_error_from_errno();
354 		goto done;
355 	}
356 done:
357 	free(path);
358 	return err;
359 }
360 
361 const struct got_error *
362 got_object_open(struct got_object **obj, struct got_repository *repo,
363     struct got_object_id *id)
364 {
365 	const struct got_error *err = NULL;
366 	char *path;
367 	int fd;
368 
369 	*obj = got_repo_get_cached_object(repo, id);
370 	if (*obj != NULL) {
371 		(*obj)->refcnt++;
372 		return NULL;
373 	}
374 
375 	err = object_path(&path, id, repo);
376 	if (err)
377 		return err;
378 
379 	fd = open(path, O_RDONLY | O_NOFOLLOW, GOT_DEFAULT_FILE_MODE);
380 	if (fd == -1) {
381 		if (errno != ENOENT) {
382 			err = got_error_from_errno();
383 			goto done;
384 		}
385 		err = got_packfile_open_object(obj, id, repo);
386 		if (err)
387 			goto done;
388 		if (*obj == NULL)
389 			err = got_error(GOT_ERR_NO_OBJ);
390 	} else {
391 		err = read_object_header_privsep(obj, fd);
392 		if (err)
393 			goto done;
394 		memcpy((*obj)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
395 	}
396 
397 	if (err == NULL) {
398 		(*obj)->refcnt++;
399 		err = got_repo_cache_object(repo, id, *obj);
400 	}
401 done:
402 	free(path);
403 	if (fd != -1)
404 		close(fd);
405 	return err;
406 
407 }
408 
409 const struct got_error *
410 got_object_open_by_id_str(struct got_object **obj, struct got_repository *repo,
411     const char *id_str)
412 {
413 	struct got_object_id id;
414 
415 	if (!got_parse_sha1_digest(id.sha1, id_str))
416 		return got_error(GOT_ERR_BAD_OBJ_ID_STR);
417 
418 	return got_object_open(obj, repo, &id);
419 }
420 
421 void
422 got_object_close(struct got_object *obj)
423 {
424 	if (obj->refcnt > 0) {
425 		obj->refcnt--;
426 		if (obj->refcnt > 0)
427 			return;
428 	}
429 
430 	if (obj->flags & GOT_OBJ_FLAG_DELTIFIED) {
431 		struct got_delta *delta;
432 		while (!SIMPLEQ_EMPTY(&obj->deltas.entries)) {
433 			delta = SIMPLEQ_FIRST(&obj->deltas.entries);
434 			SIMPLEQ_REMOVE_HEAD(&obj->deltas.entries, entry);
435 			got_delta_close(delta);
436 		}
437 	}
438 	if (obj->flags & GOT_OBJ_FLAG_PACKED)
439 		free(obj->path_packfile);
440 	free(obj);
441 }
442 
443 struct got_commit_object *
444 got_object_commit_alloc_partial(void)
445 {
446 	struct got_commit_object *commit;
447 
448 	commit = calloc(1, sizeof(*commit));
449 	if (commit == NULL)
450 		return NULL;
451 	commit->tree_id = calloc(1, sizeof(*commit->tree_id));
452 	if (commit->tree_id == NULL) {
453 		free(commit);
454 		return NULL;
455 	}
456 
457 	SIMPLEQ_INIT(&commit->parent_ids);
458 
459 	return commit;
460 }
461 
462 const struct got_error *
463 got_object_open_as_commit(struct got_commit_object **commit,
464     struct got_repository *repo, struct got_object_id *id)
465 {
466 	const struct got_error *err;
467 	struct got_object *obj;
468 
469 	*commit = NULL;
470 
471 	err = got_object_open(&obj, repo, id);
472 	if (err)
473 		return err;
474 	if (got_object_get_type(obj) != GOT_OBJ_TYPE_COMMIT) {
475 		err = got_error(GOT_ERR_OBJ_TYPE);
476 		goto done;
477 	}
478 
479 	err = got_object_commit_open(commit, repo, obj);
480 done:
481 	got_object_close(obj);
482 	return err;
483 }
484 
485 const struct got_error *
486 got_object_commit_add_parent(struct got_commit_object *commit,
487     const char *id_str)
488 {
489 	const struct got_error *err = NULL;
490 	struct got_object_qid *qid;
491 
492 	qid = calloc(1, sizeof(*qid));
493 	if (qid == NULL)
494 		return got_error_from_errno();
495 
496 	qid->id = calloc(1, sizeof(*qid->id));
497 	if (qid->id == NULL) {
498 		err = got_error_from_errno();
499 		free(qid);
500 		return err;
501 	}
502 
503 	if (!got_parse_sha1_digest(qid->id->sha1, id_str)) {
504 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
505 		free(qid->id);
506 		free(qid);
507 		return err;
508 	}
509 
510 	SIMPLEQ_INSERT_TAIL(&commit->parent_ids, qid, entry);
511 	commit->nparents++;
512 
513 	return NULL;
514 }
515 
516 static const struct got_error *
517 parse_gmtoff(time_t *gmtoff, const char *tzstr)
518 {
519 	int sign = 1;
520 	const char *p = tzstr;
521 	time_t h, m;
522 
523 	*gmtoff = 0;
524 
525 	if (*p == '-')
526 		sign = -1;
527 	else if (*p != '+')
528 		return got_error(GOT_ERR_BAD_OBJ_DATA);
529 	p++;
530 	if (!isdigit(*p) && !isdigit(*(p + 1)))
531 		return got_error(GOT_ERR_BAD_OBJ_DATA);
532 	h = (((*p - '0') * 10) + (*(p + 1) - '0'));
533 
534 	p += 2;
535 	if (!isdigit(*p) && !isdigit(*(p + 1)))
536 		return got_error(GOT_ERR_BAD_OBJ_DATA);
537 	m = ((*p - '0') * 10) + (*(p + 1) - '0');
538 
539 	*gmtoff = (h * 60 * 60 + m * 60) * sign;
540 	return NULL;
541 }
542 
543 static const struct got_error *
544 parse_commit_time(struct tm *tm, char *committer)
545 {
546 	const struct got_error *err = NULL;
547 	const char *errstr;
548 	char *space, *tzstr;
549 	time_t gmtoff;
550 	time_t time;
551 
552 	/* Parse and strip off trailing timezone indicator string. */
553 	space = strrchr(committer, ' ');
554 	if (space == NULL)
555 		return got_error(GOT_ERR_BAD_OBJ_DATA);
556 	tzstr = strdup(space + 1);
557 	if (tzstr == NULL)
558 		return got_error_from_errno();
559 	err = parse_gmtoff(&gmtoff, tzstr);
560 	free(tzstr);
561 	if (err)
562 		return err;
563 	*space = '\0';
564 
565 	/* Timestamp is separated from committer name + email by space. */
566 	space = strrchr(committer, ' ');
567 	if (space == NULL)
568 		return got_error(GOT_ERR_BAD_OBJ_DATA);
569 
570 	/* Timestamp parsed here is expressed in comitter's local time. */
571 	time = strtonum(space + 1, 0, INT64_MAX, &errstr);
572 	if (errstr)
573 		return got_error(GOT_ERR_BAD_OBJ_DATA);
574 
575 	/* Express the time stamp in UTC. */
576 	memset(tm, 0, sizeof(*tm));
577 	time -= gmtoff;
578 	if (localtime_r(&time, tm) == NULL)
579 		return got_error_from_errno();
580 	tm->tm_gmtoff = gmtoff;
581 
582 	/* Strip off parsed time information, leaving just author and email. */
583 	*space = '\0';
584 
585 	return NULL;
586 }
587 
588 static const struct got_error *
589 parse_commit_object(struct got_commit_object **commit, char *buf, size_t len)
590 {
591 	const struct got_error *err = NULL;
592 	char *s = buf;
593 	size_t tlen;
594 	ssize_t remain = (ssize_t)len;
595  
596 	*commit = got_object_commit_alloc_partial();
597 	if (*commit == NULL)
598 		return got_error_from_errno();
599 
600 	tlen = strlen(GOT_COMMIT_TAG_TREE);
601 	if (strncmp(s, GOT_COMMIT_TAG_TREE, tlen) == 0) {
602 		remain -= tlen;
603 		if (remain < SHA1_DIGEST_STRING_LENGTH) {
604 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
605 			goto done;
606 		}
607 		s += tlen;
608 		if (!got_parse_sha1_digest((*commit)->tree_id->sha1, s)) {
609 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
610 			goto done;
611 		}
612 		remain -= SHA1_DIGEST_STRING_LENGTH;
613 		s += SHA1_DIGEST_STRING_LENGTH;
614 	} else {
615 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
616 		goto done;
617 	}
618 
619 	tlen = strlen(GOT_COMMIT_TAG_PARENT);
620 	while (strncmp(s, GOT_COMMIT_TAG_PARENT, tlen) == 0) {
621 		remain -= tlen;
622 		if (remain < SHA1_DIGEST_STRING_LENGTH) {
623 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
624 			goto done;
625 		}
626 		s += tlen;
627 		err = got_object_commit_add_parent(*commit, s);
628 		if (err)
629 			goto done;
630 
631 		remain -= SHA1_DIGEST_STRING_LENGTH;
632 		s += SHA1_DIGEST_STRING_LENGTH;
633 	}
634 
635 	tlen = strlen(GOT_COMMIT_TAG_AUTHOR);
636 	if (strncmp(s, GOT_COMMIT_TAG_AUTHOR, tlen) == 0) {
637 		char *p;
638 		size_t slen;
639 
640 		remain -= tlen;
641 		if (remain <= 0) {
642 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
643 			goto done;
644 		}
645 		s += tlen;
646 		p = strchr(s, '\n');
647 		if (p == NULL) {
648 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
649 			goto done;
650 		}
651 		*p = '\0';
652 		slen = strlen(s);
653 		err = parse_commit_time(&(*commit)->tm_author, s);
654 		if (err)
655 			goto done;
656 		(*commit)->author = strdup(s);
657 		if ((*commit)->author == NULL) {
658 			err = got_error_from_errno();
659 			goto done;
660 		}
661 		s += slen + 1;
662 		remain -= slen + 1;
663 	}
664 
665 	tlen = strlen(GOT_COMMIT_TAG_COMMITTER);
666 	if (strncmp(s, GOT_COMMIT_TAG_COMMITTER, tlen) == 0) {
667 		char *p;
668 		size_t slen;
669 
670 		remain -= tlen;
671 		if (remain <= 0) {
672 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
673 			goto done;
674 		}
675 		s += tlen;
676 		p = strchr(s, '\n');
677 		if (p == NULL) {
678 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
679 			goto done;
680 		}
681 		*p = '\0';
682 		slen = strlen(s);
683 		err = parse_commit_time(&(*commit)->tm_committer, s);
684 		if (err)
685 			goto done;
686 		(*commit)->committer = strdup(s);
687 		if ((*commit)->committer == NULL) {
688 			err = got_error_from_errno();
689 			goto done;
690 		}
691 		s += slen + 1;
692 		remain -= slen + 1;
693 	}
694 
695 	(*commit)->logmsg = strndup(s, remain);
696 	if ((*commit)->logmsg == NULL) {
697 		err = got_error_from_errno();
698 		goto done;
699 	}
700 done:
701 	if (err) {
702 		got_object_commit_close(*commit);
703 		*commit = NULL;
704 	}
705 	return err;
706 }
707 
708 static void
709 tree_entry_close(struct got_tree_entry *te)
710 {
711 	free(te->id);
712 	free(te->name);
713 	free(te);
714 }
715 
716 struct got_tree_entry *
717 got_alloc_tree_entry_partial(void)
718 {
719 	struct got_tree_entry *te;
720 
721 	te = calloc(1, sizeof(*te));
722 	if (te == NULL)
723 		return NULL;
724 
725 	te->id = calloc(1, sizeof(*te->id));
726 	if (te->id == NULL) {
727 		free(te);
728 		te = NULL;
729 	}
730 	return te;
731 }
732 
733 static const struct got_error *
734 parse_tree_entry(struct got_tree_entry **te, size_t *elen, char *buf,
735     size_t maxlen)
736 {
737 	char *p = buf, *space;
738 	const struct got_error *err = NULL;
739 
740 	*te = got_alloc_tree_entry_partial();
741 	if (*te == NULL)
742 		return got_error_from_errno();
743 
744 	*elen = strlen(buf) + 1;
745 	if (*elen > maxlen) {
746 		free(*te);
747 		*te = NULL;
748 		return got_error(GOT_ERR_BAD_OBJ_DATA);
749 	}
750 
751 	space = strchr(buf, ' ');
752 	if (space == NULL) {
753 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
754 		free(*te);
755 		*te = NULL;
756 		return err;
757 	}
758 	while (*p != ' ') {
759 		if (*p < '0' && *p > '7') {
760 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
761 			goto done;
762 		}
763 		(*te)->mode <<= 3;
764 		(*te)->mode |= *p - '0';
765 		p++;
766 	}
767 
768 	(*te)->name = strdup(space + 1);
769 	if (*elen > maxlen || maxlen - *elen < SHA1_DIGEST_LENGTH) {
770 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
771 		goto done;
772 	}
773 	buf += strlen(buf) + 1;
774 	memcpy((*te)->id->sha1, buf, SHA1_DIGEST_LENGTH);
775 	*elen += SHA1_DIGEST_LENGTH;
776 done:
777 	if (err) {
778 		tree_entry_close(*te);
779 		*te = NULL;
780 	}
781 	return err;
782 }
783 
784 static const struct got_error *
785 parse_tree_object(struct got_tree_object **tree, uint8_t *buf, size_t len)
786 {
787 	const struct got_error *err;
788 	size_t remain = len;
789 
790 	*tree = calloc(1, sizeof(**tree));
791 	if (*tree == NULL)
792 		return got_error_from_errno();
793 
794 	SIMPLEQ_INIT(&(*tree)->entries);
795 
796 	while (remain > 0) {
797 		struct got_tree_entry *te;
798 		size_t elen;
799 
800 		err = parse_tree_entry(&te, &elen, buf, remain);
801 		if (err)
802 			return err;
803 		(*tree)->nentries++;
804 		SIMPLEQ_INSERT_TAIL(&(*tree)->entries, te, entry);
805 		buf += elen;
806 		remain -= elen;
807 	}
808 
809 	if (remain != 0) {
810 		got_object_tree_close(*tree);
811 		return got_error(GOT_ERR_BAD_OBJ_DATA);
812 	}
813 
814 	return NULL;
815 }
816 
817 static const struct got_error *
818 read_to_mem(uint8_t **outbuf, size_t *outlen, FILE *f)
819 {
820 	const struct got_error *err = NULL;
821 	static const size_t blocksize = 512;
822 	size_t n, total, remain;
823 	uint8_t *buf;
824 
825 	*outbuf = NULL;
826 	*outlen = 0;
827 
828 	buf = calloc(1, blocksize);
829 	if (buf == NULL)
830 		return got_error_from_errno();
831 
832 	remain = blocksize;
833 	total = 0;
834 	while (1) {
835 		if (remain == 0) {
836 			uint8_t *newbuf;
837 			newbuf = reallocarray(buf, 1, total + blocksize);
838 			if (newbuf == NULL) {
839 				err = got_error_from_errno();
840 				goto done;
841 			}
842 			buf = newbuf;
843 			remain += blocksize;
844 		}
845 		n = fread(buf + total, 1, remain, f);
846 		if (n == 0) {
847 			if (ferror(f)) {
848 				err = got_ferror(f, GOT_ERR_IO);
849 				goto done;
850 			}
851 			break; /* EOF */
852 		}
853 		remain -= n;
854 		total += n;
855 	};
856 
857 done:
858 	if (err == NULL) {
859 		*outbuf = buf;
860 		*outlen = total;
861 	} else
862 		free(buf);
863 	return err;
864 }
865 
866 static const struct got_error *
867 read_commit_object(struct got_commit_object **commit, struct got_object *obj,
868     FILE *f)
869 {
870 	const struct got_error *err = NULL;
871 	size_t len;
872 	uint8_t *p;
873 
874 	if (obj->flags & GOT_OBJ_FLAG_PACKED)
875 		err = read_to_mem(&p, &len, f);
876 	else
877 		err = got_inflate_to_mem(&p, &len, f);
878 	if (err)
879 		return err;
880 
881 	if (len < obj->hdrlen + obj->size) {
882 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
883 		goto done;
884 	}
885 
886 	/* Skip object header. */
887 	len -= obj->hdrlen;
888 	err = parse_commit_object(commit, p + obj->hdrlen, len);
889 	free(p);
890 done:
891 	return err;
892 }
893 
894 static void
895 read_commit_object_privsep_child(struct got_object *obj, int obj_fd,
896     int imsg_fds[2])
897 {
898 	const struct got_error *err = NULL;
899 	struct got_commit_object *commit = NULL;
900 	struct imsgbuf ibuf;
901 	FILE *f = NULL;
902 	int status = 0;
903 
904 	setproctitle("read commit object");
905 	close(imsg_fds[0]);
906 	imsg_init(&ibuf, imsg_fds[1]);
907 
908 	/* revoke access to most system calls */
909 	if (pledge("stdio", NULL) == -1) {
910 		err = got_error_from_errno();
911 		goto done;
912 	}
913 
914 	f = fdopen(obj_fd, "rb");
915 	if (f == NULL) {
916 		err = got_error_from_errno();
917 		close(obj_fd);
918 		goto done;
919 	}
920 
921 	err = read_commit_object(&commit, obj, f);
922 	if (err)
923 		goto done;
924 
925 	err = got_privsep_send_commit(&ibuf, commit);
926 done:
927 	if (commit)
928 		got_object_commit_close(commit);
929 	if (err) {
930 		got_privsep_send_error(&ibuf, err);
931 		status = 1;
932 	}
933 	if (f)
934 		fclose(f);
935 	imsg_clear(&ibuf);
936 	close(imsg_fds[1]);
937 	_exit(status);
938 }
939 
940 static const struct got_error *
941 read_commit_object_privsep(struct got_commit_object **commit,
942     struct got_repository *repo, struct got_object *obj, int fd)
943 {
944 	const struct got_error *err = NULL, *err_child = NULL;
945 	struct imsgbuf parent_ibuf;
946 	int imsg_fds[2];
947 	pid_t pid;
948 
949 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1)
950 		return got_error_from_errno();
951 
952 	pid = fork();
953 	if (pid == -1)
954 		return got_error_from_errno();
955 	else if (pid == 0) {
956 		read_commit_object_privsep_child(obj, fd, imsg_fds);
957 		/* not reached */
958 	}
959 
960 	close(imsg_fds[1]);
961 	imsg_init(&parent_ibuf, imsg_fds[0]);
962 	err = got_privsep_recv_commit(commit, &parent_ibuf);
963 	imsg_clear(&parent_ibuf);
964 	err_child = wait_for_child(pid);
965 	close(imsg_fds[0]);
966 	return err ? err : err_child;
967 }
968 
969 const struct got_error *
970 got_object_commit_open(struct got_commit_object **commit,
971     struct got_repository *repo, struct got_object *obj)
972 {
973 	const struct got_error *err = NULL;
974 
975 	*commit = got_repo_get_cached_commit(repo, &obj->id);
976 	if (*commit != NULL) {
977 		(*commit)->refcnt++;
978 		return NULL;
979 	}
980 
981 	if (obj->type != GOT_OBJ_TYPE_COMMIT)
982 		return got_error(GOT_ERR_OBJ_TYPE);
983 
984 	if (obj->flags & GOT_OBJ_FLAG_PACKED) {
985 		uint8_t *buf;
986 		size_t len;
987 		err = got_packfile_extract_object_to_mem(&buf, &len, obj, repo);
988 		if (err)
989 			return err;
990 		obj->size = len;
991 		err = parse_commit_object(commit, buf, len);
992 		free(buf);
993 	} else {
994 		int fd;
995 		err = open_loose_object(&fd, obj, repo);
996 		if (err)
997 			return err;
998 		err = read_commit_object_privsep(commit, repo, obj, fd);
999 		close(fd);
1000 	}
1001 
1002 	if (err == NULL) {
1003 		(*commit)->refcnt++;
1004 		err = got_repo_cache_commit(repo, &obj->id, *commit);
1005 	}
1006 
1007 	return err;
1008 }
1009 
1010 void
1011 got_object_commit_close(struct got_commit_object *commit)
1012 {
1013 	struct got_object_qid *qid;
1014 
1015 	if (commit->refcnt > 0) {
1016 		commit->refcnt--;
1017 		if (commit->refcnt > 0)
1018 			return;
1019 	}
1020 
1021 	while (!SIMPLEQ_EMPTY(&commit->parent_ids)) {
1022 		qid = SIMPLEQ_FIRST(&commit->parent_ids);
1023 		SIMPLEQ_REMOVE_HEAD(&commit->parent_ids, entry);
1024 		free(qid->id);
1025 		free(qid);
1026 	}
1027 
1028 	free(commit->tree_id);
1029 	free(commit->author);
1030 	free(commit->committer);
1031 	free(commit->logmsg);
1032 	free(commit);
1033 }
1034 
1035 static const struct got_error *
1036 read_tree_object(struct got_tree_object **tree, struct got_object *obj, FILE *f)
1037 {
1038 	const struct got_error *err = NULL;
1039 	size_t len;
1040 	uint8_t *p;
1041 
1042 	if (obj->flags & GOT_OBJ_FLAG_PACKED)
1043 		err = read_to_mem(&p, &len, f);
1044 	else
1045 		err = got_inflate_to_mem(&p, &len, f);
1046 	if (err)
1047 		return err;
1048 
1049 	if (len < obj->hdrlen + obj->size) {
1050 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
1051 		goto done;
1052 	}
1053 
1054 	/* Skip object header. */
1055 	len -= obj->hdrlen;
1056 	err = parse_tree_object(tree, p + obj->hdrlen, len);
1057 	free(p);
1058 done:
1059 	return err;
1060 }
1061 
1062 static void
1063 read_tree_object_privsep_child(struct got_object *obj, int obj_fd,
1064     int imsg_fds[2])
1065 {
1066 	const struct got_error *err = NULL;
1067 	struct got_tree_object *tree = NULL;
1068 	struct imsgbuf ibuf;
1069 	FILE *f = NULL;
1070 	int status = 0;
1071 
1072 	setproctitle("read tree object");
1073 	close(imsg_fds[0]);
1074 	imsg_init(&ibuf, imsg_fds[1]);
1075 
1076 	/* revoke access to most system calls */
1077 	if (pledge("stdio", NULL) == -1) {
1078 		err = got_error_from_errno();
1079 		goto done;
1080 	}
1081 
1082 	f = fdopen(obj_fd, "rb");
1083 	if (f == NULL) {
1084 		err = got_error_from_errno();
1085 		close(obj_fd);
1086 		goto done;
1087 	}
1088 
1089 	err = read_tree_object(&tree, obj, f);
1090 	if (err)
1091 		goto done;
1092 
1093 	err = got_privsep_send_tree(&ibuf, tree);
1094 done:
1095 	if (tree)
1096 		got_object_tree_close(tree);
1097 	if (err) {
1098 		got_privsep_send_error(&ibuf, err);
1099 		status = 1;
1100 	}
1101 	if (f)
1102 		fclose(f);
1103 	imsg_clear(&ibuf);
1104 	close(imsg_fds[1]);
1105 	_exit(status);
1106 }
1107 
1108 static const struct got_error *
1109 read_tree_object_privsep(struct got_tree_object **tree, struct got_object *obj,
1110     int fd)
1111 {
1112 	const struct got_error *err = NULL, *err_child = NULL;
1113 	struct imsgbuf parent_ibuf;
1114 	int imsg_fds[2];
1115 	pid_t pid;
1116 
1117 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1)
1118 		return got_error_from_errno();
1119 
1120 	pid = fork();
1121 	if (pid == -1)
1122 		return got_error_from_errno();
1123 	else if (pid == 0) {
1124 		read_tree_object_privsep_child(obj, fd, imsg_fds);
1125 		/* not reached */
1126 	}
1127 
1128 	close(imsg_fds[1]);
1129 	imsg_init(&parent_ibuf, imsg_fds[0]);
1130 	err = got_privsep_recv_tree(tree, &parent_ibuf);
1131 	imsg_clear(&parent_ibuf);
1132 	err_child = wait_for_child(pid);
1133 	close(imsg_fds[0]);
1134 	return err ? err : err_child;
1135 }
1136 
1137 const struct got_error *
1138 got_object_tree_open(struct got_tree_object **tree,
1139     struct got_repository *repo, struct got_object *obj)
1140 {
1141 	const struct got_error *err = NULL;
1142 
1143 	*tree = got_repo_get_cached_tree(repo, &obj->id);
1144 	if (*tree != NULL) {
1145 		(*tree)->refcnt++;
1146 		return NULL;
1147 	}
1148 
1149 	if (obj->type != GOT_OBJ_TYPE_TREE)
1150 		return got_error(GOT_ERR_OBJ_TYPE);
1151 
1152 	if (obj->flags & GOT_OBJ_FLAG_PACKED) {
1153 		uint8_t *buf;
1154 		size_t len;
1155 		err = got_packfile_extract_object_to_mem(&buf, &len, obj, repo);
1156 		if (err)
1157 			return err;
1158 		obj->size = len;
1159 		err = parse_tree_object(tree, buf, len);
1160 		free(buf);
1161 	} else {
1162 		int fd;
1163 		err = open_loose_object(&fd, obj, repo);
1164 		if (err)
1165 			return err;
1166 		err = read_tree_object_privsep(tree, obj, fd);
1167 		close(fd);
1168 	}
1169 
1170 	if (err == NULL) {
1171 		(*tree)->refcnt++;
1172 		err = got_repo_cache_tree(repo, &obj->id, *tree);
1173 	}
1174 
1175 	return err;
1176 }
1177 
1178 const struct got_error *
1179 got_object_open_as_tree(struct got_tree_object **tree,
1180     struct got_repository *repo, struct got_object_id *id)
1181 {
1182 	const struct got_error *err;
1183 	struct got_object *obj;
1184 
1185 	*tree = NULL;
1186 
1187 	err = got_object_open(&obj, repo, id);
1188 	if (err)
1189 		return err;
1190 	if (got_object_get_type(obj) != GOT_OBJ_TYPE_TREE) {
1191 		err = got_error(GOT_ERR_OBJ_TYPE);
1192 		goto done;
1193 	}
1194 
1195 	err = got_object_tree_open(tree, repo, obj);
1196 done:
1197 	got_object_close(obj);
1198 	return err;
1199 }
1200 
1201 void
1202 got_object_tree_close(struct got_tree_object *tree)
1203 {
1204 	struct got_tree_entry *te;
1205 
1206 	if (tree->refcnt > 0) {
1207 		tree->refcnt--;
1208 		if (tree->refcnt > 0)
1209 			return;
1210 	}
1211 
1212 	while (!SIMPLEQ_EMPTY(&tree->entries)) {
1213 		te = SIMPLEQ_FIRST(&tree->entries);
1214 		SIMPLEQ_REMOVE_HEAD(&tree->entries, entry);
1215 		tree_entry_close(te);
1216 	}
1217 
1218 	free(tree);
1219 }
1220 
1221 static const struct got_error *
1222 read_blob_object_privsep_child(int outfd, int infd, int imsg_fds[2])
1223 {
1224 	const struct got_error *err = NULL;
1225 	struct imsgbuf ibuf;
1226 	int status = 0;
1227 	size_t size;
1228 	FILE *infile = NULL;
1229 
1230 	setproctitle("read blob object");
1231 	close(imsg_fds[0]);
1232 	imsg_init(&ibuf, imsg_fds[1]);
1233 
1234 	/* revoke access to most system calls */
1235 	if (pledge("stdio", NULL) == -1) {
1236 		err = got_error_from_errno();
1237 		goto done;
1238 	}
1239 
1240 	infile = fdopen(infd, "rb");
1241 	if (infile == NULL) {
1242 		err = got_error_from_errno();
1243 		close(infd);
1244 		goto done;
1245 	}
1246 	err = got_inflate_to_fd(&size, infile, outfd);
1247 	fclose(infile);
1248 	if (err)
1249 		goto done;
1250 
1251 	err = got_privsep_send_blob(&ibuf, size);
1252 done:
1253 	if (err) {
1254 		got_privsep_send_error(&ibuf, err);
1255 		status = 1;
1256 	}
1257 	close(outfd);
1258 	imsg_clear(&ibuf);
1259 	close(imsg_fds[1]);
1260 	_exit(status);
1261 }
1262 
1263 static const struct got_error *
1264 read_blob_object_privsep(size_t *size, int outfd, int infd)
1265 {
1266 	struct imsgbuf parent_ibuf;
1267 	int imsg_fds[2];
1268 	const struct got_error *err = NULL, *err_child = NULL;
1269 	pid_t pid;
1270 
1271 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1)
1272 		return got_error_from_errno();
1273 
1274 	pid = fork();
1275 	if (pid == -1)
1276 		return got_error_from_errno();
1277 	else if (pid == 0) {
1278 		read_blob_object_privsep_child(outfd, infd, imsg_fds);
1279 		/* not reached */
1280 	}
1281 
1282 	close(imsg_fds[1]);
1283 	imsg_init(&parent_ibuf, imsg_fds[0]);
1284 	err = got_privsep_recv_blob(size, &parent_ibuf);
1285 	imsg_clear(&parent_ibuf);
1286 	err_child = wait_for_child(pid);
1287 	close(imsg_fds[0]);
1288 	if (lseek(outfd, SEEK_SET, 0) == -1)
1289 		err = got_error_from_errno();
1290 	return err ? err : err_child;
1291 }
1292 
1293 const struct got_error *
1294 got_object_blob_open(struct got_blob_object **blob,
1295     struct got_repository *repo, struct got_object *obj, size_t blocksize)
1296 {
1297 	const struct got_error *err = NULL;
1298 
1299 	if (obj->type != GOT_OBJ_TYPE_BLOB)
1300 		return got_error(GOT_ERR_OBJ_TYPE);
1301 
1302 	if (blocksize < obj->hdrlen)
1303 		return got_error(GOT_ERR_NO_SPACE);
1304 
1305 	*blob = calloc(1, sizeof(**blob));
1306 	if (*blob == NULL)
1307 		return got_error_from_errno();
1308 
1309 	(*blob)->read_buf = calloc(1, blocksize);
1310 	if ((*blob)->read_buf == NULL) {
1311 		err = got_error_from_errno();
1312 		goto done;
1313 	}
1314 	if (obj->flags & GOT_OBJ_FLAG_PACKED) {
1315 		err = got_packfile_extract_object(&((*blob)->f), obj, repo);
1316 		if (err)
1317 			goto done;
1318 	} else {
1319 		int infd, outfd;
1320 		size_t size;
1321 		struct stat sb;
1322 
1323 		err = open_loose_object(&infd, obj, repo);
1324 		if (err)
1325 			goto done;
1326 
1327 
1328 		outfd = got_opentempfd();
1329 		if (outfd == -1) {
1330 			err = got_error_from_errno();
1331 			close(infd);
1332 			goto done;
1333 		}
1334 
1335 		err = read_blob_object_privsep(&size, outfd, infd);
1336 		close(infd);
1337 		if (err)
1338 			goto done;
1339 
1340 		if (size != obj->hdrlen + obj->size) {
1341 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1342 			close(outfd);
1343 			goto done;
1344 		}
1345 
1346 		if (fstat(outfd, &sb) == -1) {
1347 			err = got_error_from_errno();
1348 			close(outfd);
1349 			goto done;
1350 		}
1351 
1352 		if (sb.st_size != size) {
1353 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1354 			close(outfd);
1355 			goto done;
1356 		}
1357 
1358 		(*blob)->f = fdopen(outfd, "rb");
1359 		if ((*blob)->f == NULL) {
1360 			err = got_error_from_errno();
1361 			close(outfd);
1362 			goto done;
1363 		}
1364 	}
1365 
1366 	(*blob)->hdrlen = obj->hdrlen;
1367 	(*blob)->blocksize = blocksize;
1368 	memcpy(&(*blob)->id.sha1, obj->id.sha1, SHA1_DIGEST_LENGTH);
1369 
1370 done:
1371 	if (err && *blob) {
1372 		if ((*blob)->f)
1373 			fclose((*blob)->f);
1374 		free((*blob)->read_buf);
1375 		free(*blob);
1376 		*blob = NULL;
1377 	}
1378 	return err;
1379 }
1380 
1381 const struct got_error *
1382 got_object_open_as_blob(struct got_blob_object **blob,
1383     struct got_repository *repo, struct got_object_id *id,
1384     size_t blocksize)
1385 {
1386 	const struct got_error *err;
1387 	struct got_object *obj;
1388 
1389 	*blob = NULL;
1390 
1391 	err = got_object_open(&obj, repo, id);
1392 	if (err)
1393 		return err;
1394 	if (got_object_get_type(obj) != GOT_OBJ_TYPE_BLOB) {
1395 		err = got_error(GOT_ERR_OBJ_TYPE);
1396 		goto done;
1397 	}
1398 
1399 	err = got_object_blob_open(blob, repo, obj, blocksize);
1400 done:
1401 	got_object_close(obj);
1402 	return err;
1403 }
1404 
1405 void
1406 got_object_blob_close(struct got_blob_object *blob)
1407 {
1408 	free(blob->read_buf);
1409 	fclose(blob->f);
1410 	free(blob);
1411 }
1412 
1413 char *
1414 got_object_blob_id_str(struct got_blob_object *blob, char *buf, size_t size)
1415 {
1416 	return got_sha1_digest_to_str(blob->id.sha1, buf, size);
1417 }
1418 
1419 size_t
1420 got_object_blob_get_hdrlen(struct got_blob_object *blob)
1421 {
1422 	return blob->hdrlen;
1423 }
1424 
1425 const uint8_t *
1426 got_object_blob_get_read_buf(struct got_blob_object *blob)
1427 {
1428 	return blob->read_buf;
1429 }
1430 
1431 const struct got_error *
1432 got_object_blob_read_block(size_t *outlenp, struct got_blob_object *blob)
1433 {
1434 	size_t n;
1435 
1436 	n = fread(blob->read_buf, 1, blob->blocksize, blob->f);
1437 	if (n == 0 && ferror(blob->f))
1438 		return got_ferror(blob->f, GOT_ERR_IO);
1439 	*outlenp = n;
1440 	return NULL;
1441 }
1442 
1443 const struct got_error *
1444 got_object_blob_dump_to_file(size_t *total_len, FILE *outfile,
1445     struct got_blob_object *blob)
1446 {
1447 	const struct got_error *err = NULL;
1448 	size_t len, hdrlen;
1449 
1450 	*total_len = 0;
1451 	hdrlen = got_object_blob_get_hdrlen(blob);
1452 	do {
1453 		err = got_object_blob_read_block(&len, blob);
1454 		if (err)
1455 			return err;
1456 		if (len == 0)
1457 			break;
1458 		*total_len += len;
1459 		/* Skip blob object header first time around. */
1460 		fwrite(got_object_blob_get_read_buf(blob) + hdrlen,
1461 		    len - hdrlen, 1, outfile);
1462 		hdrlen = 0;
1463 	} while (len != 0);
1464 
1465 	fflush(outfile);
1466 	rewind(outfile);
1467 
1468 	return NULL;
1469 }
1470 
1471 static struct got_tree_entry *
1472 find_entry_by_name(struct got_tree_object *tree, const char *name)
1473 {
1474 	struct got_tree_entry *te;
1475 
1476 	SIMPLEQ_FOREACH(te, &tree->entries, entry) {
1477 		if (strcmp(te->name, name) == 0)
1478 			return te;
1479 	}
1480 	return NULL;
1481 }
1482 
1483 const struct got_error *
1484 got_object_open_by_path(struct got_object **obj, struct got_repository *repo,
1485     struct got_object_id *commit_id, const char *path)
1486 {
1487 	const struct got_error *err = NULL;
1488 	struct got_commit_object *commit = NULL;
1489 	struct got_tree_object *tree = NULL;
1490 	struct got_tree_entry *te = NULL;
1491 	char *seg, *s, *s0 = NULL;
1492 	size_t len = strlen(path);
1493 
1494 	*obj = NULL;
1495 
1496 	/* We are expecting an absolute in-repository path. */
1497 	if (path[0] != '/')
1498 		return got_error(GOT_ERR_NOT_ABSPATH);
1499 
1500 	err = got_object_open_as_commit(&commit, repo, commit_id);
1501 	if (err)
1502 		goto done;
1503 
1504 	/* Handle opening of root of commit's tree. */
1505 	if (path[1] == '\0') {
1506 		err = got_object_open(obj, repo, commit->tree_id);
1507 		if (err)
1508 			goto done;
1509 		return NULL;
1510 	}
1511 
1512 	err = got_object_open_as_tree(&tree, repo, commit->tree_id);
1513 	if (err)
1514 		goto done;
1515 
1516 	s0 = strdup(path);
1517 	if (s0 == NULL) {
1518 		err = got_error_from_errno();
1519 		goto done;
1520 	}
1521 	err = got_canonpath(path, s0, len + 1);
1522 	if (err)
1523 		goto done;
1524 
1525 	s = s0;
1526 	s++; /* skip leading '/' */
1527 	len--;
1528 	seg = s;
1529 	while (len > 0) {
1530 		struct got_tree_object *next_tree;
1531 
1532 		if (*s != '/') {
1533 			s++;
1534 			len--;
1535 			if (*s)
1536 				continue;
1537 		}
1538 
1539 		/* end of path segment */
1540 		*s = '\0';
1541 
1542 		te = find_entry_by_name(tree, seg);
1543 		if (te == NULL) {
1544 			err = got_error(GOT_ERR_NO_OBJ);
1545 			goto done;
1546 		}
1547 
1548 		if (len == 0)
1549 			break;
1550 
1551 		seg = s + 1;
1552 		s++;
1553 		len--;
1554 		if (*s) {
1555 			err = got_object_open_as_tree(&next_tree, repo,
1556 			    te->id);
1557 			te = NULL;
1558 			if (err)
1559 				goto done;
1560 			got_object_tree_close(tree);
1561 			tree = next_tree;
1562 		}
1563 	}
1564 
1565 	if (te) {
1566 		err = got_object_open(obj, repo, te->id);
1567 		if (err)
1568 			goto done;
1569 	} else
1570 		err = got_error(GOT_ERR_NO_OBJ);
1571 done:
1572 	free(s0);
1573 	if (commit)
1574 		got_object_commit_close(commit);
1575 	if (tree)
1576 		got_object_tree_close(tree);
1577 	return err;
1578 }