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Date:: Sun Apr 22 12:51:49 2018 UTC
Message:: read object headers with privsep
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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 
36 #include "got_error.h"
37 #include "got_object.h"
38 #include "got_repository.h"
39 
40 #include "got_lib_sha1.h"
41 #include "got_lib_delta.h"
42 #include "got_lib_pack.h"
43 #include "got_lib_path.h"
44 #include "got_lib_zbuf.h"
45 #include "got_lib_object.h"
46 #include "got_lib_privsep.h"
47 
48 #ifndef MIN
49 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
50 #endif
51 
52 #ifndef nitems
53 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
54 #endif
55 
56 #define GOT_OBJ_TAG_COMMIT	"commit"
57 #define GOT_OBJ_TAG_TREE	"tree"
58 #define GOT_OBJ_TAG_BLOB	"blob"
59 
60 #define GOT_COMMIT_TAG_TREE		"tree "
61 #define GOT_COMMIT_TAG_PARENT		"parent "
62 #define GOT_COMMIT_TAG_AUTHOR		"author "
63 #define GOT_COMMIT_TAG_COMMITTER	"committer "
64 
65 const struct got_error *
66 got_object_id_str(char **outbuf, struct got_object_id *id)
67 {
68 	static const size_t len = SHA1_DIGEST_STRING_LENGTH;
69 
70 	*outbuf = calloc(1, len);
71 	if (*outbuf == NULL)
72 		return got_error_from_errno();
73 
74 	if (got_sha1_digest_to_str(id->sha1, *outbuf, len) == NULL) {
75 		free(*outbuf);
76 		*outbuf = NULL;
77 		return got_error(GOT_ERR_BAD_OBJ_ID_STR);
78 	}
79 
80 	return NULL;
81 }
82 
83 int
84 got_object_id_cmp(struct got_object_id *id1, struct got_object_id *id2)
85 {
86 	return memcmp(id1->sha1, id2->sha1, SHA1_DIGEST_LENGTH);
87 }
88 
89 struct got_object_id *
90 got_object_id_dup(struct got_object_id *id1)
91 {
92 	struct got_object_id *id2;
93 
94 	id2 = malloc(sizeof(*id2));
95 	if (id2 == NULL)
96 		return NULL;
97 	memcpy(id2, id1, sizeof(*id2));
98 	return id2;
99 }
100 
101 struct got_object_id *
102 got_object_get_id(struct got_object *obj)
103 {
104 	return got_object_id_dup(&obj->id);
105 }
106 
107 int
108 got_object_get_type(struct got_object *obj)
109 {
110 	switch (obj->type) {
111 	case GOT_OBJ_TYPE_COMMIT:
112 	case GOT_OBJ_TYPE_TREE:
113 	case GOT_OBJ_TYPE_BLOB:
114 	case GOT_OBJ_TYPE_TAG:
115 		return obj->type;
116 	default:
117 		abort();
118 		break;
119 	}
120 
121 	/* not reached */
122 	return 0;
123 }
124 
125 static const struct got_error *
126 parse_object_header(struct got_object **obj, char *buf, size_t len)
127 {
128 	const char *obj_tags[] = {
129 		GOT_OBJ_TAG_COMMIT,
130 		GOT_OBJ_TAG_TREE,
131 		GOT_OBJ_TAG_BLOB
132 	};
133 	const int obj_types[] = {
134 		GOT_OBJ_TYPE_COMMIT,
135 		GOT_OBJ_TYPE_TREE,
136 		GOT_OBJ_TYPE_BLOB,
137 	};
138 	int type = 0;
139 	size_t size = 0, hdrlen = 0;
140 	int i;
141 	char *p = strchr(buf, '\0');
142 
143 	if (p == NULL)
144 		return got_error(GOT_ERR_BAD_OBJ_HDR);
145 
146 	hdrlen = strlen(buf) + 1 /* '\0' */;
147 
148 	for (i = 0; i < nitems(obj_tags); i++) {
149 		const char *tag = obj_tags[i];
150 		size_t tlen = strlen(tag);
151 		const char *errstr;
152 
153 		if (strncmp(buf, tag, tlen) != 0)
154 			continue;
155 
156 		type = obj_types[i];
157 		if (len <= tlen)
158 			return got_error(GOT_ERR_BAD_OBJ_HDR);
159 		size = strtonum(buf + tlen, 0, LONG_MAX, &errstr);
160 		if (errstr != NULL)
161 			return got_error(GOT_ERR_BAD_OBJ_HDR);
162 		break;
163 	}
164 
165 	if (type == 0)
166 		return got_error(GOT_ERR_BAD_OBJ_HDR);
167 
168 	*obj = calloc(1, sizeof(**obj));
169 	if (*obj == NULL)
170 		return got_error_from_errno();
171 	(*obj)->type = type;
172 	(*obj)->hdrlen = hdrlen;
173 	(*obj)->size = size;
174 	return NULL;
175 }
176 
177 static const struct got_error *
178 read_object_header(struct got_object **obj, FILE *f)
179 {
180 	const struct got_error *err;
181 	struct got_zstream_buf zb;
182 	char *buf;
183 	const size_t zbsize = 64;
184 	size_t outlen, totlen;
185 	int i;
186 
187 	buf = calloc(zbsize, sizeof(char));
188 	if (buf == NULL)
189 		return got_error_from_errno();
190 
191 	err = got_inflate_init(&zb, NULL, zbsize);
192 	if (err)
193 		return err;
194 
195 	i = 0;
196 	totlen = 0;
197 	do {
198 		err = got_inflate_read(&zb, f, &outlen);
199 		if (err)
200 			goto done;
201 		if (strchr(zb.outbuf, '\0') == NULL) {
202 			buf = recallocarray(buf, 1 + i, 2 + i, zbsize);
203 			if (buf == NULL) {
204 				err = got_error_from_errno();
205 				goto done;
206 			}
207 		}
208 		memcpy(buf + totlen, zb.outbuf, outlen);
209 		totlen += outlen;
210 		i++;
211 	} while (strchr(zb.outbuf, '\0') == NULL);
212 
213 	err = parse_object_header(obj, buf, totlen);
214 done:
215 	got_inflate_end(&zb);
216 	return err;
217 }
218 
219 static const struct got_error *
220 read_object_header_privsep(struct got_object **obj, int fd)
221 {
222 	struct imsgbuf parent_ibuf;
223 	int imsg_fds[2];
224 	const struct got_error *err = NULL;
225 	pid_t pid;
226 	int child_status;
227 
228 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1)
229 		return got_error_from_errno();
230 
231 	pid = fork();
232 	if (pid == -1)
233 		return got_error_from_errno();
234 	else if (pid == 0) {
235 		struct got_object *child_obj = NULL;
236 		struct imsgbuf child_ibuf;
237 		FILE *f = NULL;
238 		int status = 0;
239 
240 		setproctitle("got: read object header");
241 		close(imsg_fds[0]);
242 		imsg_init(&child_ibuf, imsg_fds[1]);
243 		if (err)
244 			goto done;
245 
246 		/* revoke access to most system calls */
247 		if (pledge("stdio", NULL) == -1) {
248 			err = got_error_from_errno();
249 			goto done;
250 		}
251 
252 		f = fdopen(fd, "rb");
253 		if (f == NULL) {
254 			err = got_error_from_errno();
255 			goto done;
256 		}
257 
258 		err = read_object_header(&child_obj, f);
259 		if (err)
260 			goto done;
261 
262 		err = got_privsep_send_obj(&child_ibuf, child_obj, 0);
263 done:
264 		if (child_obj)
265 			got_object_close(child_obj);
266 		if (err) {
267 			got_privsep_send_error(&child_ibuf, err);
268 			status = 1;
269 		}
270 		if (f)
271 			fclose(f);
272 		imsg_clear(&child_ibuf);
273 		_exit(status);
274 	}
275 
276 	close(imsg_fds[1]);
277 	imsg_init(&parent_ibuf, imsg_fds[0]);
278 	err = got_privsep_recv_obj(obj, &parent_ibuf);
279 	imsg_clear(&parent_ibuf);
280 	waitpid(pid, &child_status, 0);
281 	close(imsg_fds[0]);
282 	return err;
283 }
284 
285 static const struct got_error *
286 object_path(char **path, struct got_object_id *id, struct got_repository *repo)
287 {
288 	const struct got_error *err = NULL;
289 	char *hex;
290 	char *path_objects = got_repo_get_path_objects(repo);
291 
292 	*path = NULL;
293 
294 	if (path_objects == NULL)
295 		return got_error_from_errno();
296 
297 	err = got_object_id_str(&hex, id);
298 	if (err)
299 		return err;
300 
301 	if (asprintf(path, "%s/%.2x/%s", path_objects,
302 	    id->sha1[0], hex + 2) == -1)
303 		err = got_error_from_errno();
304 
305 	free(hex);
306 	free(path_objects);
307 	return err;
308 }
309 
310 static const struct got_error *
311 open_loose_object(FILE **f, struct got_object *obj, struct got_repository *repo)
312 {
313 	const struct got_error *err = NULL;
314 	char *path;
315 
316 	err = object_path(&path, &obj->id, repo);
317 	if (err)
318 		return err;
319 	*f = fopen(path, "rb");
320 	if (*f == NULL) {
321 		err = got_error_from_errno();
322 		goto done;
323 	}
324 done:
325 	free(path);
326 	return err;
327 }
328 
329 const struct got_error *
330 got_object_open(struct got_object **obj, struct got_repository *repo,
331     struct got_object_id *id)
332 {
333 	const struct got_error *err = NULL;
334 	char *path;
335 	int fd;
336 
337 	err = object_path(&path, id, repo);
338 	if (err)
339 		return err;
340 
341 	fd = open(path, O_RDONLY | O_NOFOLLOW, GOT_DEFAULT_FILE_MODE);
342 	if (fd == -1) {
343 		if (errno != ENOENT) {
344 			err = got_error_from_errno();
345 			goto done;
346 		}
347 		err = got_packfile_open_object(obj, id, repo);
348 		if (err)
349 			goto done;
350 		if (*obj == NULL)
351 			err = got_error(GOT_ERR_NO_OBJ);
352 	} else {
353 		err = read_object_header_privsep(obj, fd);
354 		if (err)
355 			goto done;
356 		memcpy((*obj)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
357 	}
358 done:
359 	free(path);
360 	if (fd != -1)
361 		close(fd);
362 	return err;
363 
364 }
365 
366 const struct got_error *
367 got_object_open_by_id_str(struct got_object **obj, struct got_repository *repo,
368     const char *id_str)
369 {
370 	struct got_object_id id;
371 
372 	if (!got_parse_sha1_digest(id.sha1, id_str))
373 		return got_error(GOT_ERR_BAD_OBJ_ID_STR);
374 
375 	return got_object_open(obj, repo, &id);
376 }
377 
378 void
379 got_object_close(struct got_object *obj)
380 {
381 	if (obj->flags & GOT_OBJ_FLAG_DELTIFIED) {
382 		struct got_delta *delta;
383 		while (!SIMPLEQ_EMPTY(&obj->deltas.entries)) {
384 			delta = SIMPLEQ_FIRST(&obj->deltas.entries);
385 			SIMPLEQ_REMOVE_HEAD(&obj->deltas.entries, entry);
386 			got_delta_close(delta);
387 		}
388 	}
389 	if (obj->flags & GOT_OBJ_FLAG_PACKED)
390 		free(obj->path_packfile);
391 	free(obj);
392 }
393 
394 static const struct got_error *
395 parse_commit_object(struct got_commit_object **commit, char *buf, size_t len)
396 {
397 	const struct got_error *err = NULL;
398 	char *s = buf;
399 	size_t tlen;
400 	ssize_t remain = (ssize_t)len;
401  
402 	*commit = calloc(1, sizeof(**commit));
403 	if (*commit == NULL)
404 		return got_error_from_errno();
405 	(*commit)->tree_id = calloc(1, sizeof(*(*commit)->tree_id));
406 	if ((*commit)->tree_id == NULL) {
407 		err = got_error_from_errno();
408 		free(*commit);
409 		*commit = NULL;
410 		return err;
411 	}
412 
413 	SIMPLEQ_INIT(&(*commit)->parent_ids);
414 
415 	tlen = strlen(GOT_COMMIT_TAG_TREE);
416 	if (strncmp(s, GOT_COMMIT_TAG_TREE, tlen) == 0) {
417 		remain -= tlen;
418 		if (remain < SHA1_DIGEST_STRING_LENGTH) {
419 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
420 			goto done;
421 		}
422 		s += tlen;
423 		if (!got_parse_sha1_digest((*commit)->tree_id->sha1, s)) {
424 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
425 			goto done;
426 		}
427 		remain -= SHA1_DIGEST_STRING_LENGTH;
428 		s += SHA1_DIGEST_STRING_LENGTH;
429 	} else {
430 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
431 		goto done;
432 	}
433 
434 	tlen = strlen(GOT_COMMIT_TAG_PARENT);
435 	while (strncmp(s, GOT_COMMIT_TAG_PARENT, tlen) == 0) {
436 		struct got_parent_id *pid;
437 
438 		remain -= tlen;
439 		if (remain < SHA1_DIGEST_STRING_LENGTH) {
440 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
441 			goto done;
442 		}
443 
444 		pid = calloc(1, sizeof(*pid));
445 		if (pid == NULL) {
446 			err = got_error_from_errno();
447 			goto done;
448 		}
449 		pid->id = calloc(1, sizeof(*pid->id));
450 		if (pid->id == NULL) {
451 			err = got_error_from_errno();
452 			free(pid);
453 			goto done;
454 		}
455 		s += tlen;
456 		if (!got_parse_sha1_digest(pid->id->sha1, s)) {
457 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
458 			free(pid->id);
459 			free(pid);
460 			goto done;
461 		}
462 		SIMPLEQ_INSERT_TAIL(&(*commit)->parent_ids, pid, entry);
463 		(*commit)->nparents++;
464 
465 		remain -= SHA1_DIGEST_STRING_LENGTH;
466 		s += SHA1_DIGEST_STRING_LENGTH;
467 	}
468 
469 	tlen = strlen(GOT_COMMIT_TAG_AUTHOR);
470 	if (strncmp(s, GOT_COMMIT_TAG_AUTHOR, tlen) == 0) {
471 		char *p;
472 
473 		remain -= tlen;
474 		if (remain <= 0) {
475 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
476 			goto done;
477 		}
478 		s += tlen;
479 		p = strchr(s, '\n');
480 		if (p == NULL) {
481 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
482 			goto done;
483 		}
484 		*p = '\0';
485 		(*commit)->author = strdup(s);
486 		if ((*commit)->author == NULL) {
487 			err = got_error_from_errno();
488 			goto done;
489 		}
490 		s += strlen((*commit)->author) + 1;
491 		remain -= strlen((*commit)->author) + 1;
492 	}
493 
494 	tlen = strlen(GOT_COMMIT_TAG_COMMITTER);
495 	if (strncmp(s, GOT_COMMIT_TAG_COMMITTER, tlen) == 0) {
496 		char *p;
497 
498 		remain -= tlen;
499 		if (remain <= 0) {
500 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
501 			goto done;
502 		}
503 		s += tlen;
504 		p = strchr(s, '\n');
505 		if (p == NULL) {
506 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
507 			goto done;
508 		}
509 		*p = '\0';
510 		(*commit)->committer = strdup(s);
511 		if ((*commit)->committer == NULL) {
512 			err = got_error_from_errno();
513 			goto done;
514 		}
515 		s += strlen((*commit)->committer) + 1;
516 		remain -= strlen((*commit)->committer) + 1;
517 	}
518 
519 	(*commit)->logmsg = strndup(s, remain);
520 	if ((*commit)->logmsg == NULL) {
521 		err = got_error_from_errno();
522 		goto done;
523 	}
524 done:
525 	if (err) {
526 		got_object_commit_close(*commit);
527 		*commit = NULL;
528 	}
529 	return err;
530 }
531 
532 static void
533 tree_entry_close(struct got_tree_entry *te)
534 {
535 	free(te->id);
536 	free(te->name);
537 	free(te);
538 }
539 
540 static const struct got_error *
541 parse_tree_entry(struct got_tree_entry **te, size_t *elen, char *buf,
542     size_t maxlen)
543 {
544 	char *p = buf, *space;
545 	const struct got_error *err = NULL;
546 
547 	*te = calloc(1, sizeof(**te));
548 	if (*te == NULL)
549 		return got_error_from_errno();
550 
551 	(*te)->id = calloc(1, sizeof(*(*te)->id));
552 	if ((*te)->id == NULL) {
553 		err = got_error_from_errno();
554 		free(*te);
555 		*te = NULL;
556 		return err;
557 	}
558 
559 	*elen = strlen(buf) + 1;
560 	if (*elen > maxlen) {
561 		free(*te);
562 		*te = NULL;
563 		return got_error(GOT_ERR_BAD_OBJ_DATA);
564 	}
565 
566 	space = strchr(buf, ' ');
567 	if (space == NULL) {
568 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
569 		free(*te);
570 		*te = NULL;
571 		return err;
572 	}
573 	while (*p != ' ') {
574 		if (*p < '0' && *p > '7') {
575 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
576 			goto done;
577 		}
578 		(*te)->mode <<= 3;
579 		(*te)->mode |= *p - '0';
580 		p++;
581 	}
582 
583 	(*te)->name = strdup(space + 1);
584 	if (*elen > maxlen || maxlen - *elen < SHA1_DIGEST_LENGTH) {
585 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
586 		goto done;
587 	}
588 	buf += strlen(buf) + 1;
589 	memcpy((*te)->id->sha1, buf, SHA1_DIGEST_LENGTH);
590 	*elen += SHA1_DIGEST_LENGTH;
591 done:
592 	if (err) {
593 		tree_entry_close(*te);
594 		*te = NULL;
595 	}
596 	return err;
597 }
598 
599 static const struct got_error *
600 parse_tree_object(struct got_tree_object **tree, struct got_repository *repo,
601     uint8_t *buf, size_t len)
602 {
603 	const struct got_error *err;
604 	size_t remain = len;
605 
606 	*tree = calloc(1, sizeof(**tree));
607 	if (*tree == NULL)
608 		return got_error_from_errno();
609 
610 	SIMPLEQ_INIT(&(*tree)->entries);
611 
612 	while (remain > 0) {
613 		struct got_tree_entry *te;
614 		size_t elen;
615 
616 		err = parse_tree_entry(&te, &elen, buf, remain);
617 		if (err)
618 			return err;
619 		(*tree)->nentries++;
620 		SIMPLEQ_INSERT_TAIL(&(*tree)->entries, te, entry);
621 		buf += elen;
622 		remain -= elen;
623 	}
624 
625 	if (remain != 0) {
626 		got_object_tree_close(*tree);
627 		return got_error(GOT_ERR_BAD_OBJ_DATA);
628 	}
629 
630 	return NULL;
631 }
632 
633 static const struct got_error *
634 read_to_mem(uint8_t **outbuf, size_t *outlen, FILE *f)
635 {
636 	const struct got_error *err = NULL;
637 	static const size_t blocksize = 512;
638 	size_t n, total, remain;
639 	uint8_t *buf;
640 
641 	*outbuf = NULL;
642 	*outlen = 0;
643 
644 	buf = calloc(1, blocksize);
645 	if (buf == NULL)
646 		return got_error_from_errno();
647 
648 	remain = blocksize;
649 	total = 0;
650 	while (1) {
651 		if (remain == 0) {
652 			uint8_t *newbuf;
653 			newbuf = reallocarray(buf, 1, total + blocksize);
654 			if (newbuf == NULL) {
655 				err = got_error_from_errno();
656 				goto done;
657 			}
658 			buf = newbuf;
659 			remain += blocksize;
660 		}
661 		n = fread(buf + total, 1, remain, f);
662 		if (n == 0) {
663 			if (ferror(f)) {
664 				err = got_ferror(f, GOT_ERR_IO);
665 				goto done;
666 			}
667 			break; /* EOF */
668 		}
669 		remain -= n;
670 		total += n;
671 	};
672 
673 done:
674 	if (err == NULL) {
675 		*outbuf = buf;
676 		*outlen = total;
677 	} else
678 		free(buf);
679 	return err;
680 }
681 
682 static const struct got_error *
683 read_commit_object(struct got_commit_object **commit,
684     struct got_repository *repo, struct got_object *obj, FILE *f)
685 {
686 	const struct got_error *err = NULL;
687 	size_t len;
688 	uint8_t *p;
689 
690 	if (obj->flags & GOT_OBJ_FLAG_PACKED)
691 		err = read_to_mem(&p, &len, f);
692 	else
693 		err = got_inflate_to_mem(&p, &len, f);
694 	if (err)
695 		return err;
696 
697 	if (len < obj->hdrlen + obj->size) {
698 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
699 		goto done;
700 	}
701 
702 	/* Skip object header. */
703 	len -= obj->hdrlen;
704 	err = parse_commit_object(commit, p + obj->hdrlen, len);
705 	free(p);
706 done:
707 	return err;
708 }
709 
710 const struct got_error *
711 got_object_commit_open(struct got_commit_object **commit,
712     struct got_repository *repo, struct got_object *obj)
713 {
714 	const struct got_error *err = NULL;
715 
716 	if (obj->type != GOT_OBJ_TYPE_COMMIT)
717 		return got_error(GOT_ERR_OBJ_TYPE);
718 
719 	if (obj->flags & GOT_OBJ_FLAG_PACKED) {
720 		uint8_t *buf;
721 		size_t len;
722 		err = got_packfile_extract_object_to_mem(&buf, &len, obj, repo);
723 		if (err)
724 			return err;
725 		obj->size = len;
726 		err = parse_commit_object(commit, buf, len);
727 		free(buf);
728 	} else {
729 		FILE *f;
730 		err = open_loose_object(&f, obj, repo);
731 		if (err)
732 			return err;
733 		err = read_commit_object(commit, repo, obj, f);
734 		fclose(f);
735 	}
736 	return err;
737 }
738 
739 void
740 got_object_commit_close(struct got_commit_object *commit)
741 {
742 	struct got_parent_id *pid;
743 
744 	while (!SIMPLEQ_EMPTY(&commit->parent_ids)) {
745 		pid = SIMPLEQ_FIRST(&commit->parent_ids);
746 		SIMPLEQ_REMOVE_HEAD(&commit->parent_ids, entry);
747 		free(pid->id);
748 		free(pid);
749 	}
750 
751 	free(commit->tree_id);
752 	free(commit->author);
753 	free(commit->committer);
754 	free(commit->logmsg);
755 	free(commit);
756 }
757 
758 static const struct got_error *
759 read_tree_object(struct got_tree_object **tree,
760     struct got_repository *repo, struct got_object *obj, FILE *f)
761 {
762 	const struct got_error *err = NULL;
763 	size_t len;
764 	uint8_t *p;
765 
766 	if (obj->flags & GOT_OBJ_FLAG_PACKED)
767 		err = read_to_mem(&p, &len, f);
768 	else
769 		err = got_inflate_to_mem(&p, &len, f);
770 	if (err)
771 		return err;
772 
773 	if (len < obj->hdrlen + obj->size) {
774 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
775 		goto done;
776 	}
777 
778 	/* Skip object header. */
779 	len -= obj->hdrlen;
780 	err = parse_tree_object(tree, repo, p + obj->hdrlen, len);
781 	free(p);
782 done:
783 	return err;
784 }
785 
786 const struct got_error *
787 got_object_tree_open(struct got_tree_object **tree,
788     struct got_repository *repo, struct got_object *obj)
789 {
790 	const struct got_error *err = NULL;
791 
792 	if (obj->type != GOT_OBJ_TYPE_TREE)
793 		return got_error(GOT_ERR_OBJ_TYPE);
794 
795 	if (obj->flags & GOT_OBJ_FLAG_PACKED) {
796 		uint8_t *buf;
797 		size_t len;
798 		err = got_packfile_extract_object_to_mem(&buf, &len, obj, repo);
799 		if (err)
800 			return err;
801 		obj->size = len;
802 		err = parse_tree_object(tree, repo, buf, len);
803 		free(buf);
804 	} else {
805 		FILE *f;
806 		err = open_loose_object(&f, obj, repo);
807 		if (err)
808 			return err;
809 		err = read_tree_object(tree, repo, obj, f);
810 		fclose(f);
811 	}
812 	return err;
813 }
814 
815 void
816 got_object_tree_close(struct got_tree_object *tree)
817 {
818 	struct got_tree_entry *te;
819 
820 	while (!SIMPLEQ_EMPTY(&tree->entries)) {
821 		te = SIMPLEQ_FIRST(&tree->entries);
822 		SIMPLEQ_REMOVE_HEAD(&tree->entries, entry);
823 		tree_entry_close(te);
824 	}
825 
826 	free(tree);
827 }
828 
829 const struct got_error *
830 got_object_blob_open(struct got_blob_object **blob,
831     struct got_repository *repo, struct got_object *obj, size_t blocksize)
832 {
833 	const struct got_error *err = NULL;
834 
835 	if (obj->type != GOT_OBJ_TYPE_BLOB)
836 		return got_error(GOT_ERR_OBJ_TYPE);
837 
838 	if (blocksize < obj->hdrlen)
839 		return got_error(GOT_ERR_NO_SPACE);
840 
841 	*blob = calloc(1, sizeof(**blob));
842 	if (*blob == NULL)
843 		return got_error_from_errno();
844 
845 	if (obj->flags & GOT_OBJ_FLAG_PACKED) {
846 		(*blob)->read_buf = calloc(1, blocksize);
847 		if ((*blob)->read_buf == NULL) {
848 			err = got_error_from_errno();
849 			free(*blob);
850 			*blob = NULL;
851 			return err;
852 		}
853 		err = got_packfile_extract_object(&((*blob)->f), obj, repo);
854 		if (err) {
855 			free((*blob)->read_buf);
856 			free(*blob);
857 			*blob = NULL;
858 			return err;
859 		}
860 	} else {
861 		err = open_loose_object(&((*blob)->f), obj, repo);
862 		if (err) {
863 			free(*blob);
864 			*blob = NULL;
865 			return err;
866 		}
867 
868 		err = got_inflate_init(&(*blob)->zb, NULL, blocksize);
869 		if (err != NULL) {
870 			fclose((*blob)->f);
871 			free(*blob);
872 			*blob = NULL;
873 			return err;
874 		}
875 
876 		(*blob)->read_buf = (*blob)->zb.outbuf;
877 		(*blob)->flags |= GOT_BLOB_F_COMPRESSED;
878 	}
879 
880 	(*blob)->hdrlen = obj->hdrlen;
881 	(*blob)->blocksize = blocksize;
882 	memcpy(&(*blob)->id.sha1, obj->id.sha1, SHA1_DIGEST_LENGTH);
883 
884 	return err;
885 }
886 
887 void
888 got_object_blob_close(struct got_blob_object *blob)
889 {
890 	if (blob->flags & GOT_BLOB_F_COMPRESSED)
891 		got_inflate_end(&blob->zb);
892 	else
893 		free(blob->read_buf);
894 	fclose(blob->f);
895 	free(blob);
896 }
897 
898 char *
899 got_object_blob_id_str(struct got_blob_object *blob, char *buf, size_t size)
900 {
901 	return got_sha1_digest_to_str(blob->id.sha1, buf, size);
902 }
903 
904 size_t
905 got_object_blob_get_hdrlen(struct got_blob_object *blob)
906 {
907 	return blob->hdrlen;
908 }
909 
910 const uint8_t *
911 got_object_blob_get_read_buf(struct got_blob_object *blob)
912 {
913 	return blob->read_buf;
914 }
915 
916 const struct got_error *
917 got_object_blob_read_block(size_t *outlenp, struct got_blob_object *blob)
918 {
919 	size_t n;
920 
921 	if (blob->flags & GOT_BLOB_F_COMPRESSED)
922 		return got_inflate_read(&blob->zb, blob->f, outlenp);
923 
924 	n = fread(blob->read_buf, 1, blob->blocksize, blob->f);
925 	if (n == 0 && ferror(blob->f))
926 		return got_ferror(blob->f, GOT_ERR_IO);
927 	*outlenp = n;
928 	return NULL;
929 }