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Date:: Mon Jul 23 09:41:06 2018 UTC
Message:: fix leak in object_path()
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_inflate.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 = malloc(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, int fd)
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 = malloc(zbsize);
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_fd(&zb, fd, &outlen);
208 		if (err)
209 			goto done;
210 		if (strchr(zb.outbuf, '\0') == NULL) {
211 			buf = reallocarray(buf, 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 	int status = 0;
235 
236 	setproctitle("read object header");
237 	close(imsg_fds[0]);
238 	imsg_init(&ibuf, imsg_fds[1]);
239 
240 	/* revoke access to most system calls */
241 	if (pledge("stdio", NULL) == -1) {
242 		err = got_error_from_errno();
243 		goto done;
244 	}
245 
246 	err = read_object_header(&obj, obj_fd);
247 	if (err)
248 		goto done;
249 
250 	err = got_privsep_send_obj(&ibuf, obj, 0);
251 done:
252 	if (obj)
253 		got_object_close(obj);
254 	if (err) {
255 		got_privsep_send_error(&ibuf, err);
256 		status = 1;
257 	}
258 	close(obj_fd);
259 	imsg_clear(&ibuf);
260 	close(imsg_fds[1]);
261 	_exit(status);
262 }
263 
264 static const struct got_error *
265 wait_for_child(pid_t pid)
266 {
267 	int child_status;
268 
269 	waitpid(pid, &child_status, 0);
270 
271 	if (!WIFEXITED(child_status))
272 		return got_error(GOT_ERR_PRIVSEP_DIED);
273 
274 	if (WEXITSTATUS(child_status) != 0)
275 		return got_error(GOT_ERR_PRIVSEP_EXIT);
276 
277 	return NULL;
278 }
279 
280 static const struct got_error *
281 read_object_header_privsep(struct got_object **obj, int fd)
282 {
283 	struct imsgbuf parent_ibuf;
284 	int imsg_fds[2];
285 	const struct got_error *err = NULL, *err_child = NULL;
286 	pid_t pid;
287 
288 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1)
289 		return got_error_from_errno();
290 
291 	pid = fork();
292 	if (pid == -1)
293 		return got_error_from_errno();
294 	else if (pid == 0) {
295 		read_object_header_privsep_child(fd, imsg_fds);
296 		/* not reached */
297 	}
298 
299 	close(imsg_fds[1]);
300 	imsg_init(&parent_ibuf, imsg_fds[0]);
301 	err = got_privsep_recv_obj(obj, &parent_ibuf);
302 	imsg_clear(&parent_ibuf);
303 	err_child = wait_for_child(pid);
304 	close(imsg_fds[0]);
305 	return err ? err : err_child;
306 }
307 
308 static const struct got_error *
309 object_path(char **path, struct got_object_id *id, struct got_repository *repo)
310 {
311 	const struct got_error *err = NULL;
312 	char *hex = NULL;
313 	char *path_objects = got_repo_get_path_objects(repo);
314 
315 	*path = NULL;
316 
317 	if (path_objects == NULL)
318 		return got_error_from_errno();
319 
320 	err = got_object_id_str(&hex, id);
321 	if (err)
322 		goto done;
323 
324 	if (asprintf(path, "%s/%.2x/%s", path_objects,
325 	    id->sha1[0], hex + 2) == -1)
326 		err = got_error_from_errno();
327 
328 done:
329 	free(hex);
330 	free(path_objects);
331 	return err;
332 }
333 
334 static const struct got_error *
335 open_loose_object(int *fd, struct got_object *obj, struct got_repository *repo)
336 {
337 	const struct got_error *err = NULL;
338 	char *path;
339 
340 	err = object_path(&path, &obj->id, repo);
341 	if (err)
342 		return err;
343 	*fd = open(path, O_RDONLY | O_NOFOLLOW, GOT_DEFAULT_FILE_MODE);
344 	if (*fd == -1) {
345 		err = got_error_from_errno();
346 		goto done;
347 	}
348 done:
349 	free(path);
350 	return err;
351 }
352 
353 const struct got_error *
354 got_object_open(struct got_object **obj, struct got_repository *repo,
355     struct got_object_id *id)
356 {
357 	const struct got_error *err = NULL;
358 	char *path;
359 	int fd;
360 
361 	*obj = got_repo_get_cached_object(repo, id);
362 	if (*obj != NULL) {
363 		(*obj)->refcnt++;
364 		return NULL;
365 	}
366 
367 	err = object_path(&path, id, repo);
368 	if (err)
369 		return err;
370 
371 	fd = open(path, O_RDONLY | O_NOFOLLOW, GOT_DEFAULT_FILE_MODE);
372 	if (fd == -1) {
373 		if (errno != ENOENT) {
374 			err = got_error_from_errno();
375 			goto done;
376 		}
377 		err = got_packfile_open_object(obj, id, repo);
378 		if (err)
379 			goto done;
380 		if (*obj == NULL)
381 			err = got_error(GOT_ERR_NO_OBJ);
382 	} else {
383 		err = read_object_header_privsep(obj, fd);
384 		if (err)
385 			goto done;
386 		memcpy((*obj)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
387 	}
388 
389 	if (err == NULL) {
390 		(*obj)->refcnt++;
391 		err = got_repo_cache_object(repo, id, *obj);
392 	}
393 done:
394 	free(path);
395 	if (fd != -1)
396 		close(fd);
397 	return err;
398 
399 }
400 
401 const struct got_error *
402 got_object_open_by_id_str(struct got_object **obj, struct got_repository *repo,
403     const char *id_str)
404 {
405 	struct got_object_id id;
406 
407 	if (!got_parse_sha1_digest(id.sha1, id_str))
408 		return got_error(GOT_ERR_BAD_OBJ_ID_STR);
409 
410 	return got_object_open(obj, repo, &id);
411 }
412 
413 void
414 got_object_close(struct got_object *obj)
415 {
416 	if (obj->refcnt > 0) {
417 		obj->refcnt--;
418 		if (obj->refcnt > 0)
419 			return;
420 	}
421 
422 	if (obj->flags & GOT_OBJ_FLAG_DELTIFIED) {
423 		struct got_delta *delta;
424 		while (!SIMPLEQ_EMPTY(&obj->deltas.entries)) {
425 			delta = SIMPLEQ_FIRST(&obj->deltas.entries);
426 			SIMPLEQ_REMOVE_HEAD(&obj->deltas.entries, entry);
427 			got_delta_close(delta);
428 		}
429 	}
430 	if (obj->flags & GOT_OBJ_FLAG_PACKED)
431 		free(obj->path_packfile);
432 	free(obj);
433 }
434 
435 struct got_commit_object *
436 got_object_commit_alloc_partial(void)
437 {
438 	struct got_commit_object *commit;
439 
440 	commit = calloc(1, sizeof(*commit));
441 	if (commit == NULL)
442 		return NULL;
443 	commit->tree_id = calloc(1, sizeof(*commit->tree_id));
444 	if (commit->tree_id == NULL) {
445 		free(commit);
446 		return NULL;
447 	}
448 
449 	SIMPLEQ_INIT(&commit->parent_ids);
450 
451 	return commit;
452 }
453 
454 const struct got_error *
455 got_object_open_as_commit(struct got_commit_object **commit,
456     struct got_repository *repo, struct got_object_id *id)
457 {
458 	const struct got_error *err;
459 	struct got_object *obj;
460 
461 	*commit = NULL;
462 
463 	err = got_object_open(&obj, repo, id);
464 	if (err)
465 		return err;
466 	if (got_object_get_type(obj) != GOT_OBJ_TYPE_COMMIT) {
467 		err = got_error(GOT_ERR_OBJ_TYPE);
468 		goto done;
469 	}
470 
471 	err = got_object_commit_open(commit, repo, obj);
472 done:
473 	got_object_close(obj);
474 	return err;
475 }
476 
477 const struct got_error *
478 got_object_qid_alloc(struct got_object_qid **qid, struct got_object_id *id)
479 {
480 	const struct got_error *err = NULL;
481 
482 	*qid = calloc(1, sizeof(**qid));
483 	if (*qid == NULL)
484 		return got_error_from_errno();
485 
486 	(*qid)->id = got_object_id_dup(id);
487 	if ((*qid)->id == NULL) {
488 		err = got_error_from_errno();
489 		got_object_qid_free(*qid);
490 		*qid = NULL;
491 		return err;
492 	}
493 
494 	return NULL;
495 }
496 
497 void
498 got_object_qid_free(struct got_object_qid *qid)
499 {
500 	free(qid->id);
501 	free(qid);
502 }
503 
504 const struct got_error *
505 got_object_commit_add_parent(struct got_commit_object *commit,
506     const char *id_str)
507 {
508 	const struct got_error *err = NULL;
509 	struct got_object_qid *qid;
510 
511 	qid = malloc(sizeof(*qid));
512 	if (qid == NULL)
513 		return got_error_from_errno();
514 
515 	qid->id = malloc(sizeof(*qid->id));
516 	if (qid->id == NULL) {
517 		err = got_error_from_errno();
518 		got_object_qid_free(qid);
519 		return err;
520 	}
521 
522 	if (!got_parse_sha1_digest(qid->id->sha1, id_str)) {
523 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
524 		free(qid->id);
525 		free(qid);
526 		return err;
527 	}
528 
529 	SIMPLEQ_INSERT_TAIL(&commit->parent_ids, qid, entry);
530 	commit->nparents++;
531 
532 	return NULL;
533 }
534 
535 static const struct got_error *
536 parse_gmtoff(time_t *gmtoff, const char *tzstr)
537 {
538 	int sign = 1;
539 	const char *p = tzstr;
540 	time_t h, m;
541 
542 	*gmtoff = 0;
543 
544 	if (*p == '-')
545 		sign = -1;
546 	else if (*p != '+')
547 		return got_error(GOT_ERR_BAD_OBJ_DATA);
548 	p++;
549 	if (!isdigit(*p) && !isdigit(*(p + 1)))
550 		return got_error(GOT_ERR_BAD_OBJ_DATA);
551 	h = (((*p - '0') * 10) + (*(p + 1) - '0'));
552 
553 	p += 2;
554 	if (!isdigit(*p) && !isdigit(*(p + 1)))
555 		return got_error(GOT_ERR_BAD_OBJ_DATA);
556 	m = ((*p - '0') * 10) + (*(p + 1) - '0');
557 
558 	*gmtoff = (h * 60 * 60 + m * 60) * sign;
559 	return NULL;
560 }
561 
562 static const struct got_error *
563 parse_commit_time(struct tm *tm, char *committer)
564 {
565 	const struct got_error *err = NULL;
566 	const char *errstr;
567 	char *space, *tzstr;
568 	time_t gmtoff;
569 	time_t time;
570 
571 	/* Parse and strip off trailing timezone indicator string. */
572 	space = strrchr(committer, ' ');
573 	if (space == NULL)
574 		return got_error(GOT_ERR_BAD_OBJ_DATA);
575 	tzstr = strdup(space + 1);
576 	if (tzstr == NULL)
577 		return got_error_from_errno();
578 	err = parse_gmtoff(&gmtoff, tzstr);
579 	free(tzstr);
580 	if (err)
581 		return err;
582 	*space = '\0';
583 
584 	/* Timestamp is separated from committer name + email by space. */
585 	space = strrchr(committer, ' ');
586 	if (space == NULL)
587 		return got_error(GOT_ERR_BAD_OBJ_DATA);
588 
589 	/* Timestamp parsed here is expressed in comitter's local time. */
590 	time = strtonum(space + 1, 0, INT64_MAX, &errstr);
591 	if (errstr)
592 		return got_error(GOT_ERR_BAD_OBJ_DATA);
593 
594 	/* Express the time stamp in UTC. */
595 	memset(tm, 0, sizeof(*tm));
596 	time -= gmtoff;
597 	if (localtime_r(&time, tm) == NULL)
598 		return got_error_from_errno();
599 	tm->tm_gmtoff = gmtoff;
600 
601 	/* Strip off parsed time information, leaving just author and email. */
602 	*space = '\0';
603 
604 	return NULL;
605 }
606 
607 static const struct got_error *
608 parse_commit_object(struct got_commit_object **commit, char *buf, size_t len)
609 {
610 	const struct got_error *err = NULL;
611 	char *s = buf;
612 	size_t tlen;
613 	ssize_t remain = (ssize_t)len;
614  
615 	*commit = got_object_commit_alloc_partial();
616 	if (*commit == NULL)
617 		return got_error_from_errno();
618 
619 	tlen = strlen(GOT_COMMIT_TAG_TREE);
620 	if (strncmp(s, GOT_COMMIT_TAG_TREE, 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 		if (!got_parse_sha1_digest((*commit)->tree_id->sha1, s)) {
628 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
629 			goto done;
630 		}
631 		remain -= SHA1_DIGEST_STRING_LENGTH;
632 		s += SHA1_DIGEST_STRING_LENGTH;
633 	} else {
634 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
635 		goto done;
636 	}
637 
638 	tlen = strlen(GOT_COMMIT_TAG_PARENT);
639 	while (strncmp(s, GOT_COMMIT_TAG_PARENT, tlen) == 0) {
640 		remain -= tlen;
641 		if (remain < SHA1_DIGEST_STRING_LENGTH) {
642 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
643 			goto done;
644 		}
645 		s += tlen;
646 		err = got_object_commit_add_parent(*commit, s);
647 		if (err)
648 			goto done;
649 
650 		remain -= SHA1_DIGEST_STRING_LENGTH;
651 		s += SHA1_DIGEST_STRING_LENGTH;
652 	}
653 
654 	tlen = strlen(GOT_COMMIT_TAG_AUTHOR);
655 	if (strncmp(s, GOT_COMMIT_TAG_AUTHOR, tlen) == 0) {
656 		char *p;
657 		size_t slen;
658 
659 		remain -= tlen;
660 		if (remain <= 0) {
661 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
662 			goto done;
663 		}
664 		s += tlen;
665 		p = strchr(s, '\n');
666 		if (p == NULL) {
667 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
668 			goto done;
669 		}
670 		*p = '\0';
671 		slen = strlen(s);
672 		err = parse_commit_time(&(*commit)->tm_author, s);
673 		if (err)
674 			goto done;
675 		(*commit)->author = strdup(s);
676 		if ((*commit)->author == NULL) {
677 			err = got_error_from_errno();
678 			goto done;
679 		}
680 		s += slen + 1;
681 		remain -= slen + 1;
682 	}
683 
684 	tlen = strlen(GOT_COMMIT_TAG_COMMITTER);
685 	if (strncmp(s, GOT_COMMIT_TAG_COMMITTER, tlen) == 0) {
686 		char *p;
687 		size_t slen;
688 
689 		remain -= tlen;
690 		if (remain <= 0) {
691 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
692 			goto done;
693 		}
694 		s += tlen;
695 		p = strchr(s, '\n');
696 		if (p == NULL) {
697 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
698 			goto done;
699 		}
700 		*p = '\0';
701 		slen = strlen(s);
702 		err = parse_commit_time(&(*commit)->tm_committer, s);
703 		if (err)
704 			goto done;
705 		(*commit)->committer = strdup(s);
706 		if ((*commit)->committer == NULL) {
707 			err = got_error_from_errno();
708 			goto done;
709 		}
710 		s += slen + 1;
711 		remain -= slen + 1;
712 	}
713 
714 	(*commit)->logmsg = strndup(s, remain);
715 	if ((*commit)->logmsg == NULL) {
716 		err = got_error_from_errno();
717 		goto done;
718 	}
719 done:
720 	if (err) {
721 		got_object_commit_close(*commit);
722 		*commit = NULL;
723 	}
724 	return err;
725 }
726 
727 static void
728 tree_entry_close(struct got_tree_entry *te)
729 {
730 	free(te->id);
731 	free(te->name);
732 	free(te);
733 }
734 
735 struct got_tree_entry *
736 got_alloc_tree_entry_partial(void)
737 {
738 	struct got_tree_entry *te;
739 
740 	te = calloc(1, sizeof(*te));
741 	if (te == NULL)
742 		return NULL;
743 
744 	te->id = calloc(1, sizeof(*te->id));
745 	if (te->id == NULL) {
746 		free(te);
747 		te = NULL;
748 	}
749 	return te;
750 }
751 
752 static const struct got_error *
753 parse_tree_entry(struct got_tree_entry **te, size_t *elen, char *buf,
754     size_t maxlen)
755 {
756 	char *p = buf, *space;
757 	const struct got_error *err = NULL;
758 
759 	*te = got_alloc_tree_entry_partial();
760 	if (*te == NULL)
761 		return got_error_from_errno();
762 
763 	*elen = strlen(buf) + 1;
764 	if (*elen > maxlen) {
765 		free(*te);
766 		*te = NULL;
767 		return got_error(GOT_ERR_BAD_OBJ_DATA);
768 	}
769 
770 	space = strchr(buf, ' ');
771 	if (space == NULL) {
772 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
773 		free(*te);
774 		*te = NULL;
775 		return err;
776 	}
777 	while (*p != ' ') {
778 		if (*p < '0' && *p > '7') {
779 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
780 			goto done;
781 		}
782 		(*te)->mode <<= 3;
783 		(*te)->mode |= *p - '0';
784 		p++;
785 	}
786 
787 	(*te)->name = strdup(space + 1);
788 	if (*elen > maxlen || maxlen - *elen < SHA1_DIGEST_LENGTH) {
789 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
790 		goto done;
791 	}
792 	buf += strlen(buf) + 1;
793 	memcpy((*te)->id->sha1, buf, SHA1_DIGEST_LENGTH);
794 	*elen += SHA1_DIGEST_LENGTH;
795 done:
796 	if (err) {
797 		tree_entry_close(*te);
798 		*te = NULL;
799 	}
800 	return err;
801 }
802 
803 static const struct got_error *
804 parse_tree_object(struct got_tree_object **tree, uint8_t *buf, size_t len)
805 {
806 	const struct got_error *err;
807 	size_t remain = len;
808 
809 	*tree = calloc(1, sizeof(**tree));
810 	if (*tree == NULL)
811 		return got_error_from_errno();
812 
813 	SIMPLEQ_INIT(&(*tree)->entries.head);
814 
815 	while (remain > 0) {
816 		struct got_tree_entry *te;
817 		size_t elen;
818 
819 		err = parse_tree_entry(&te, &elen, buf, remain);
820 		if (err)
821 			return err;
822 		(*tree)->entries.nentries++;
823 		SIMPLEQ_INSERT_TAIL(&(*tree)->entries.head, te, entry);
824 		buf += elen;
825 		remain -= elen;
826 	}
827 
828 	if (remain != 0) {
829 		got_object_tree_close(*tree);
830 		return got_error(GOT_ERR_BAD_OBJ_DATA);
831 	}
832 
833 	return NULL;
834 }
835 
836 static const struct got_error *
837 read_to_mem(uint8_t **outbuf, size_t *outlen, FILE *f)
838 {
839 	const struct got_error *err = NULL;
840 	static const size_t blocksize = 512;
841 	size_t n, total, remain;
842 	uint8_t *buf;
843 
844 	*outbuf = NULL;
845 	*outlen = 0;
846 
847 	buf = malloc(blocksize);
848 	if (buf == NULL)
849 		return got_error_from_errno();
850 
851 	remain = blocksize;
852 	total = 0;
853 	while (1) {
854 		if (remain == 0) {
855 			uint8_t *newbuf;
856 			newbuf = reallocarray(buf, 1, total + blocksize);
857 			if (newbuf == NULL) {
858 				err = got_error_from_errno();
859 				goto done;
860 			}
861 			buf = newbuf;
862 			remain += blocksize;
863 		}
864 		n = fread(buf + total, 1, remain, f);
865 		if (n == 0) {
866 			if (ferror(f)) {
867 				err = got_ferror(f, GOT_ERR_IO);
868 				goto done;
869 			}
870 			break; /* EOF */
871 		}
872 		remain -= n;
873 		total += n;
874 	};
875 
876 done:
877 	if (err == NULL) {
878 		*outbuf = buf;
879 		*outlen = total;
880 	} else
881 		free(buf);
882 	return err;
883 }
884 
885 static const struct got_error *
886 read_commit_object(struct got_commit_object **commit, struct got_object *obj,
887     FILE *f)
888 {
889 	const struct got_error *err = NULL;
890 	size_t len;
891 	uint8_t *p;
892 
893 	if (obj->flags & GOT_OBJ_FLAG_PACKED)
894 		err = read_to_mem(&p, &len, f);
895 	else
896 		err = got_inflate_to_mem(&p, &len, f);
897 	if (err)
898 		return err;
899 
900 	if (len < obj->hdrlen + obj->size) {
901 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
902 		goto done;
903 	}
904 
905 	/* Skip object header. */
906 	len -= obj->hdrlen;
907 	err = parse_commit_object(commit, p + obj->hdrlen, len);
908 	free(p);
909 done:
910 	return err;
911 }
912 
913 static void
914 read_commit_object_privsep_child(struct got_object *obj, int obj_fd,
915     int imsg_fds[2])
916 {
917 	const struct got_error *err = NULL;
918 	struct got_commit_object *commit = NULL;
919 	struct imsgbuf ibuf;
920 	FILE *f = NULL;
921 	int status = 0;
922 
923 	setproctitle("read commit object");
924 	close(imsg_fds[0]);
925 	imsg_init(&ibuf, imsg_fds[1]);
926 
927 	/* revoke access to most system calls */
928 	if (pledge("stdio", NULL) == -1) {
929 		err = got_error_from_errno();
930 		goto done;
931 	}
932 
933 	f = fdopen(obj_fd, "rb");
934 	if (f == NULL) {
935 		err = got_error_from_errno();
936 		close(obj_fd);
937 		goto done;
938 	}
939 
940 	err = read_commit_object(&commit, obj, f);
941 	if (err)
942 		goto done;
943 
944 	err = got_privsep_send_commit(&ibuf, commit);
945 done:
946 	if (commit)
947 		got_object_commit_close(commit);
948 	if (err) {
949 		got_privsep_send_error(&ibuf, err);
950 		status = 1;
951 	}
952 	if (f)
953 		fclose(f);
954 	imsg_clear(&ibuf);
955 	close(imsg_fds[1]);
956 	_exit(status);
957 }
958 
959 static const struct got_error *
960 read_commit_object_privsep(struct got_commit_object **commit,
961     struct got_repository *repo, struct got_object *obj, int fd)
962 {
963 	const struct got_error *err = NULL, *err_child = NULL;
964 	struct imsgbuf parent_ibuf;
965 	int imsg_fds[2];
966 	pid_t pid;
967 
968 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1)
969 		return got_error_from_errno();
970 
971 	pid = fork();
972 	if (pid == -1)
973 		return got_error_from_errno();
974 	else if (pid == 0) {
975 		read_commit_object_privsep_child(obj, fd, imsg_fds);
976 		/* not reached */
977 	}
978 
979 	close(imsg_fds[1]);
980 	imsg_init(&parent_ibuf, imsg_fds[0]);
981 	err = got_privsep_recv_commit(commit, &parent_ibuf);
982 	imsg_clear(&parent_ibuf);
983 	err_child = wait_for_child(pid);
984 	close(imsg_fds[0]);
985 	return err ? err : err_child;
986 }
987 
988 const struct got_error *
989 got_object_commit_open(struct got_commit_object **commit,
990     struct got_repository *repo, struct got_object *obj)
991 {
992 	const struct got_error *err = NULL;
993 
994 	*commit = got_repo_get_cached_commit(repo, &obj->id);
995 	if (*commit != NULL) {
996 		(*commit)->refcnt++;
997 		return NULL;
998 	}
999 
1000 	if (obj->type != GOT_OBJ_TYPE_COMMIT)
1001 		return got_error(GOT_ERR_OBJ_TYPE);
1002 
1003 	if (obj->flags & GOT_OBJ_FLAG_PACKED) {
1004 		uint8_t *buf;
1005 		size_t len;
1006 		err = got_packfile_extract_object_to_mem(&buf, &len, obj, repo);
1007 		if (err)
1008 			return err;
1009 		obj->size = len;
1010 		err = parse_commit_object(commit, buf, len);
1011 		free(buf);
1012 	} else {
1013 		int fd;
1014 		err = open_loose_object(&fd, obj, repo);
1015 		if (err)
1016 			return err;
1017 		err = read_commit_object_privsep(commit, repo, obj, fd);
1018 		close(fd);
1019 	}
1020 
1021 	if (err == NULL) {
1022 		(*commit)->refcnt++;
1023 		err = got_repo_cache_commit(repo, &obj->id, *commit);
1024 	}
1025 
1026 	return err;
1027 }
1028 
1029 void
1030 got_object_commit_close(struct got_commit_object *commit)
1031 {
1032 	struct got_object_qid *qid;
1033 
1034 	if (commit->refcnt > 0) {
1035 		commit->refcnt--;
1036 		if (commit->refcnt > 0)
1037 			return;
1038 	}
1039 
1040 	while (!SIMPLEQ_EMPTY(&commit->parent_ids)) {
1041 		qid = SIMPLEQ_FIRST(&commit->parent_ids);
1042 		SIMPLEQ_REMOVE_HEAD(&commit->parent_ids, entry);
1043 		got_object_qid_free(qid);
1044 	}
1045 
1046 	free(commit->tree_id);
1047 	free(commit->author);
1048 	free(commit->committer);
1049 	free(commit->logmsg);
1050 	free(commit);
1051 }
1052 
1053 static const struct got_error *
1054 read_tree_object(struct got_tree_object **tree, struct got_object *obj, FILE *f)
1055 {
1056 	const struct got_error *err = NULL;
1057 	size_t len;
1058 	uint8_t *p;
1059 
1060 	if (obj->flags & GOT_OBJ_FLAG_PACKED)
1061 		err = read_to_mem(&p, &len, f);
1062 	else
1063 		err = got_inflate_to_mem(&p, &len, f);
1064 	if (err)
1065 		return err;
1066 
1067 	if (len < obj->hdrlen + obj->size) {
1068 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
1069 		goto done;
1070 	}
1071 
1072 	/* Skip object header. */
1073 	len -= obj->hdrlen;
1074 	err = parse_tree_object(tree, p + obj->hdrlen, len);
1075 	free(p);
1076 done:
1077 	return err;
1078 }
1079 
1080 static void
1081 read_tree_object_privsep_child(struct got_object *obj, int obj_fd,
1082     int imsg_fds[2])
1083 {
1084 	const struct got_error *err = NULL;
1085 	struct got_tree_object *tree = NULL;
1086 	struct imsgbuf ibuf;
1087 	FILE *f = NULL;
1088 	int status = 0;
1089 
1090 	setproctitle("read tree object");
1091 	close(imsg_fds[0]);
1092 	imsg_init(&ibuf, imsg_fds[1]);
1093 
1094 	/* revoke access to most system calls */
1095 	if (pledge("stdio", NULL) == -1) {
1096 		err = got_error_from_errno();
1097 		goto done;
1098 	}
1099 
1100 	f = fdopen(obj_fd, "rb");
1101 	if (f == NULL) {
1102 		err = got_error_from_errno();
1103 		close(obj_fd);
1104 		goto done;
1105 	}
1106 
1107 	err = read_tree_object(&tree, obj, f);
1108 	if (err)
1109 		goto done;
1110 
1111 	err = got_privsep_send_tree(&ibuf, tree);
1112 done:
1113 	if (tree)
1114 		got_object_tree_close(tree);
1115 	if (err) {
1116 		got_privsep_send_error(&ibuf, err);
1117 		status = 1;
1118 	}
1119 	if (f)
1120 		fclose(f);
1121 	imsg_clear(&ibuf);
1122 	close(imsg_fds[1]);
1123 	_exit(status);
1124 }
1125 
1126 static const struct got_error *
1127 read_tree_object_privsep(struct got_tree_object **tree, struct got_object *obj,
1128     int fd)
1129 {
1130 	const struct got_error *err = NULL, *err_child = NULL;
1131 	struct imsgbuf parent_ibuf;
1132 	int imsg_fds[2];
1133 	pid_t pid;
1134 
1135 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1)
1136 		return got_error_from_errno();
1137 
1138 	pid = fork();
1139 	if (pid == -1)
1140 		return got_error_from_errno();
1141 	else if (pid == 0) {
1142 		read_tree_object_privsep_child(obj, fd, imsg_fds);
1143 		/* not reached */
1144 	}
1145 
1146 	close(imsg_fds[1]);
1147 	imsg_init(&parent_ibuf, imsg_fds[0]);
1148 	err = got_privsep_recv_tree(tree, &parent_ibuf);
1149 	imsg_clear(&parent_ibuf);
1150 	err_child = wait_for_child(pid);
1151 	close(imsg_fds[0]);
1152 	return err ? err : err_child;
1153 }
1154 
1155 const struct got_error *
1156 got_object_tree_open(struct got_tree_object **tree,
1157     struct got_repository *repo, struct got_object *obj)
1158 {
1159 	const struct got_error *err = NULL;
1160 
1161 	*tree = got_repo_get_cached_tree(repo, &obj->id);
1162 	if (*tree != NULL) {
1163 		(*tree)->refcnt++;
1164 		return NULL;
1165 	}
1166 
1167 	if (obj->type != GOT_OBJ_TYPE_TREE)
1168 		return got_error(GOT_ERR_OBJ_TYPE);
1169 
1170 	if (obj->flags & GOT_OBJ_FLAG_PACKED) {
1171 		uint8_t *buf;
1172 		size_t len;
1173 		err = got_packfile_extract_object_to_mem(&buf, &len, obj, repo);
1174 		if (err)
1175 			return err;
1176 		obj->size = len;
1177 		err = parse_tree_object(tree, buf, len);
1178 		free(buf);
1179 	} else {
1180 		int fd;
1181 		err = open_loose_object(&fd, obj, repo);
1182 		if (err)
1183 			return err;
1184 		err = read_tree_object_privsep(tree, obj, fd);
1185 		close(fd);
1186 	}
1187 
1188 	if (err == NULL) {
1189 		(*tree)->refcnt++;
1190 		err = got_repo_cache_tree(repo, &obj->id, *tree);
1191 	}
1192 
1193 	return err;
1194 }
1195 
1196 const struct got_error *
1197 got_object_open_as_tree(struct got_tree_object **tree,
1198     struct got_repository *repo, struct got_object_id *id)
1199 {
1200 	const struct got_error *err;
1201 	struct got_object *obj;
1202 
1203 	*tree = NULL;
1204 
1205 	err = got_object_open(&obj, repo, id);
1206 	if (err)
1207 		return err;
1208 	if (got_object_get_type(obj) != GOT_OBJ_TYPE_TREE) {
1209 		err = got_error(GOT_ERR_OBJ_TYPE);
1210 		goto done;
1211 	}
1212 
1213 	err = got_object_tree_open(tree, repo, obj);
1214 done:
1215 	got_object_close(obj);
1216 	return err;
1217 }
1218 
1219 void
1220 got_object_tree_close(struct got_tree_object *tree)
1221 {
1222 	struct got_tree_entry *te;
1223 
1224 	if (tree->refcnt > 0) {
1225 		tree->refcnt--;
1226 		if (tree->refcnt > 0)
1227 			return;
1228 	}
1229 
1230 	while (!SIMPLEQ_EMPTY(&tree->entries.head)) {
1231 		te = SIMPLEQ_FIRST(&tree->entries.head);
1232 		SIMPLEQ_REMOVE_HEAD(&tree->entries.head, entry);
1233 		tree_entry_close(te);
1234 	}
1235 
1236 	free(tree);
1237 }
1238 
1239 const struct got_tree_entries *
1240 got_object_tree_get_entries(struct got_tree_object *tree)
1241 {
1242 	return &tree->entries;
1243 }
1244 
1245 static const struct got_error *
1246 read_blob_object_privsep_child(int outfd, int infd, int imsg_fds[2])
1247 {
1248 	const struct got_error *err = NULL;
1249 	struct imsgbuf ibuf;
1250 	int status = 0;
1251 	size_t size;
1252 	FILE *infile = NULL;
1253 
1254 	setproctitle("read blob object");
1255 	close(imsg_fds[0]);
1256 	imsg_init(&ibuf, imsg_fds[1]);
1257 
1258 	/* revoke access to most system calls */
1259 	if (pledge("stdio", NULL) == -1) {
1260 		err = got_error_from_errno();
1261 		goto done;
1262 	}
1263 
1264 	infile = fdopen(infd, "rb");
1265 	if (infile == NULL) {
1266 		err = got_error_from_errno();
1267 		close(infd);
1268 		goto done;
1269 	}
1270 	err = got_inflate_to_fd(&size, infile, outfd);
1271 	fclose(infile);
1272 	if (err)
1273 		goto done;
1274 
1275 	err = got_privsep_send_blob(&ibuf, size);
1276 done:
1277 	if (err) {
1278 		got_privsep_send_error(&ibuf, err);
1279 		status = 1;
1280 	}
1281 	close(outfd);
1282 	imsg_clear(&ibuf);
1283 	close(imsg_fds[1]);
1284 	_exit(status);
1285 }
1286 
1287 static const struct got_error *
1288 read_blob_object_privsep(size_t *size, int outfd, int infd)
1289 {
1290 	struct imsgbuf parent_ibuf;
1291 	int imsg_fds[2];
1292 	const struct got_error *err = NULL, *err_child = NULL;
1293 	pid_t pid;
1294 
1295 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1)
1296 		return got_error_from_errno();
1297 
1298 	pid = fork();
1299 	if (pid == -1)
1300 		return got_error_from_errno();
1301 	else if (pid == 0) {
1302 		read_blob_object_privsep_child(outfd, infd, imsg_fds);
1303 		/* not reached */
1304 	}
1305 
1306 	close(imsg_fds[1]);
1307 	imsg_init(&parent_ibuf, imsg_fds[0]);
1308 	err = got_privsep_recv_blob(size, &parent_ibuf);
1309 	imsg_clear(&parent_ibuf);
1310 	err_child = wait_for_child(pid);
1311 	close(imsg_fds[0]);
1312 	if (lseek(outfd, SEEK_SET, 0) == -1)
1313 		err = got_error_from_errno();
1314 	return err ? err : err_child;
1315 }
1316 
1317 const struct got_error *
1318 got_object_blob_open(struct got_blob_object **blob,
1319     struct got_repository *repo, struct got_object *obj, size_t blocksize)
1320 {
1321 	const struct got_error *err = NULL;
1322 
1323 	if (obj->type != GOT_OBJ_TYPE_BLOB)
1324 		return got_error(GOT_ERR_OBJ_TYPE);
1325 
1326 	if (blocksize < obj->hdrlen)
1327 		return got_error(GOT_ERR_NO_SPACE);
1328 
1329 	*blob = calloc(1, sizeof(**blob));
1330 	if (*blob == NULL)
1331 		return got_error_from_errno();
1332 
1333 	(*blob)->read_buf = malloc(blocksize);
1334 	if ((*blob)->read_buf == NULL) {
1335 		err = got_error_from_errno();
1336 		goto done;
1337 	}
1338 	if (obj->flags & GOT_OBJ_FLAG_PACKED) {
1339 		err = got_packfile_extract_object(&((*blob)->f), obj, repo);
1340 		if (err)
1341 			goto done;
1342 	} else {
1343 		int infd, outfd;
1344 		size_t size;
1345 		struct stat sb;
1346 
1347 		err = open_loose_object(&infd, obj, repo);
1348 		if (err)
1349 			goto done;
1350 
1351 
1352 		outfd = got_opentempfd();
1353 		if (outfd == -1) {
1354 			err = got_error_from_errno();
1355 			close(infd);
1356 			goto done;
1357 		}
1358 
1359 		err = read_blob_object_privsep(&size, outfd, infd);
1360 		close(infd);
1361 		if (err)
1362 			goto done;
1363 
1364 		if (size != obj->hdrlen + obj->size) {
1365 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1366 			close(outfd);
1367 			goto done;
1368 		}
1369 
1370 		if (fstat(outfd, &sb) == -1) {
1371 			err = got_error_from_errno();
1372 			close(outfd);
1373 			goto done;
1374 		}
1375 
1376 		if (sb.st_size != size) {
1377 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1378 			close(outfd);
1379 			goto done;
1380 		}
1381 
1382 		(*blob)->f = fdopen(outfd, "rb");
1383 		if ((*blob)->f == NULL) {
1384 			err = got_error_from_errno();
1385 			close(outfd);
1386 			goto done;
1387 		}
1388 	}
1389 
1390 	(*blob)->hdrlen = obj->hdrlen;
1391 	(*blob)->blocksize = blocksize;
1392 	memcpy(&(*blob)->id.sha1, obj->id.sha1, SHA1_DIGEST_LENGTH);
1393 
1394 done:
1395 	if (err && *blob) {
1396 		if ((*blob)->f)
1397 			fclose((*blob)->f);
1398 		free((*blob)->read_buf);
1399 		free(*blob);
1400 		*blob = NULL;
1401 	}
1402 	return err;
1403 }
1404 
1405 const struct got_error *
1406 got_object_open_as_blob(struct got_blob_object **blob,
1407     struct got_repository *repo, struct got_object_id *id,
1408     size_t blocksize)
1409 {
1410 	const struct got_error *err;
1411 	struct got_object *obj;
1412 
1413 	*blob = NULL;
1414 
1415 	err = got_object_open(&obj, repo, id);
1416 	if (err)
1417 		return err;
1418 	if (got_object_get_type(obj) != GOT_OBJ_TYPE_BLOB) {
1419 		err = got_error(GOT_ERR_OBJ_TYPE);
1420 		goto done;
1421 	}
1422 
1423 	err = got_object_blob_open(blob, repo, obj, blocksize);
1424 done:
1425 	got_object_close(obj);
1426 	return err;
1427 }
1428 
1429 void
1430 got_object_blob_close(struct got_blob_object *blob)
1431 {
1432 	free(blob->read_buf);
1433 	fclose(blob->f);
1434 	free(blob);
1435 }
1436 
1437 char *
1438 got_object_blob_id_str(struct got_blob_object *blob, char *buf, size_t size)
1439 {
1440 	return got_sha1_digest_to_str(blob->id.sha1, buf, size);
1441 }
1442 
1443 size_t
1444 got_object_blob_get_hdrlen(struct got_blob_object *blob)
1445 {
1446 	return blob->hdrlen;
1447 }
1448 
1449 const uint8_t *
1450 got_object_blob_get_read_buf(struct got_blob_object *blob)
1451 {
1452 	return blob->read_buf;
1453 }
1454 
1455 const struct got_error *
1456 got_object_blob_read_block(size_t *outlenp, struct got_blob_object *blob)
1457 {
1458 	size_t n;
1459 
1460 	n = fread(blob->read_buf, 1, blob->blocksize, blob->f);
1461 	if (n == 0 && ferror(blob->f))
1462 		return got_ferror(blob->f, GOT_ERR_IO);
1463 	*outlenp = n;
1464 	return NULL;
1465 }
1466 
1467 const struct got_error *
1468 got_object_blob_dump_to_file(size_t *total_len, size_t *nlines,
1469     FILE *outfile, struct got_blob_object *blob)
1470 {
1471 	const struct got_error *err = NULL;
1472 	size_t len, hdrlen;
1473 	const uint8_t *buf;
1474 	int i;
1475 
1476 	if (total_len)
1477 		*total_len = 0;
1478 	if (nlines)
1479 		*nlines = 0;
1480 
1481 	hdrlen = got_object_blob_get_hdrlen(blob);
1482 	do {
1483 		err = got_object_blob_read_block(&len, blob);
1484 		if (err)
1485 			return err;
1486 		if (len == 0)
1487 			break;
1488 		if (total_len)
1489 			*total_len += len;
1490 		buf = got_object_blob_get_read_buf(blob);
1491 		if (nlines) {
1492 			for (i = 0; i < len; i++) {
1493 				if (buf[i] == '\n')
1494 					(*nlines)++;
1495 			}
1496 		}
1497 		/* Skip blob object header first time around. */
1498 		fwrite(buf + hdrlen, len - hdrlen, 1, outfile);
1499 		hdrlen = 0;
1500 	} while (len != 0);
1501 
1502 	fflush(outfile);
1503 	rewind(outfile);
1504 
1505 	return NULL;
1506 }
1507 
1508 static struct got_tree_entry *
1509 find_entry_by_name(struct got_tree_object *tree, const char *name)
1510 {
1511 	struct got_tree_entry *te;
1512 
1513 	SIMPLEQ_FOREACH(te, &tree->entries.head, entry) {
1514 		if (strcmp(te->name, name) == 0)
1515 			return te;
1516 	}
1517 	return NULL;
1518 }
1519 
1520 const struct got_error *
1521 got_object_open_by_path(struct got_object **obj, struct got_repository *repo,
1522     struct got_object_id *commit_id, const char *path)
1523 {
1524 	const struct got_error *err = NULL;
1525 	struct got_commit_object *commit = NULL;
1526 	struct got_tree_object *tree = NULL;
1527 	struct got_tree_entry *te = NULL;
1528 	char *seg, *s, *s0 = NULL;
1529 	size_t len = strlen(path);
1530 
1531 	*obj = NULL;
1532 
1533 	/* We are expecting an absolute in-repository path. */
1534 	if (path[0] != '/')
1535 		return got_error(GOT_ERR_NOT_ABSPATH);
1536 
1537 	err = got_object_open_as_commit(&commit, repo, commit_id);
1538 	if (err)
1539 		goto done;
1540 
1541 	/* Handle opening of root of commit's tree. */
1542 	if (path[1] == '\0') {
1543 		err = got_object_open(obj, repo, commit->tree_id);
1544 		goto done;
1545 	}
1546 
1547 	err = got_object_open_as_tree(&tree, repo, commit->tree_id);
1548 	if (err)
1549 		goto done;
1550 
1551 	s0 = strdup(path);
1552 	if (s0 == NULL) {
1553 		err = got_error_from_errno();
1554 		goto done;
1555 	}
1556 	err = got_canonpath(path, s0, len + 1);
1557 	if (err)
1558 		goto done;
1559 
1560 	s = s0;
1561 	s++; /* skip leading '/' */
1562 	len--;
1563 	seg = s;
1564 	while (len > 0) {
1565 		struct got_tree_object *next_tree;
1566 
1567 		if (*s != '/') {
1568 			s++;
1569 			len--;
1570 			if (*s)
1571 				continue;
1572 		}
1573 
1574 		/* end of path segment */
1575 		*s = '\0';
1576 
1577 		te = find_entry_by_name(tree, seg);
1578 		if (te == NULL) {
1579 			err = got_error(GOT_ERR_NO_OBJ);
1580 			goto done;
1581 		}
1582 
1583 		if (len == 0)
1584 			break;
1585 
1586 		seg = s + 1;
1587 		s++;
1588 		len--;
1589 		if (*s) {
1590 			err = got_object_open_as_tree(&next_tree, repo,
1591 			    te->id);
1592 			te = NULL;
1593 			if (err)
1594 				goto done;
1595 			got_object_tree_close(tree);
1596 			tree = next_tree;
1597 		}
1598 	}
1599 
1600 	if (te)
1601 		err = got_object_open(obj, repo, te->id);
1602 	else
1603 		err = got_error(GOT_ERR_NO_OBJ);
1604 done:
1605 	free(s0);
1606 	if (commit)
1607 		got_object_commit_close(commit);
1608 	if (tree)
1609 		got_object_tree_close(tree);
1610 	return err;
1611 }