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Date:: Mon Jun 4 14:22:01 2018 UTC
Message:: fix bogus free() in error path of cache_pack()
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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 
21 #include <dirent.h>
22 #include <fcntl.h>
23 #include <errno.h>
24 #include <stdio.h>
25 #include <stdint.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <limits.h>
29 #include <sha1.h>
30 #include <endian.h>
31 #include <zlib.h>
32 
33 #include "got_error.h"
34 #include "got_object.h"
35 #include "got_repository.h"
36 #include "got_opentemp.h"
37 
38 #include "got_lib_sha1.h"
39 #include "got_lib_pack.h"
40 #include "got_lib_path.h"
41 #include "got_lib_delta.h"
42 #include "got_lib_zbuf.h"
43 #include "got_lib_object.h"
44 #include "got_lib_repository.h"
45 
46 #ifndef nitems
47 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
48 #endif
49 
50 #define GOT_PACK_PREFIX		"pack-"
51 #define GOT_PACKFILE_SUFFIX	".pack"
52 #define GOT_PACKIDX_SUFFIX		".idx"
53 #define GOT_PACKFILE_NAMELEN	(strlen(GOT_PACK_PREFIX) + \
54 				SHA1_DIGEST_STRING_LENGTH - 1 + \
55 				strlen(GOT_PACKFILE_SUFFIX))
56 #define GOT_PACKIDX_NAMELEN	(strlen(GOT_PACK_PREFIX) + \
57 				SHA1_DIGEST_STRING_LENGTH - 1 + \
58 				strlen(GOT_PACKIDX_SUFFIX))
59 
60 #ifndef MIN
61 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
62 #endif
63 
64 static const struct got_error *
65 verify_fanout_table(uint32_t *fanout_table)
66 {
67 	int i;
68 
69 	for (i = 0; i < 0xff - 1; i++) {
70 		if (be32toh(fanout_table[i]) > be32toh(fanout_table[i + 1]))
71 			return got_error(GOT_ERR_BAD_PACKIDX);
72 	}
73 
74 	return NULL;
75 }
76 
77 static const struct got_error *
78 get_packfile_size(size_t *size, const char *path)
79 {
80 	struct stat sb;
81 	char *dot;
82 
83 	*size = 0;
84 
85 	dot = strrchr(path, '.');
86 	if (dot == NULL)
87 		return got_error(GOT_ERR_BAD_PATH);
88 
89 	/* Path must point to a pack index or to a pack file. */
90 	if (strcmp(dot, ".idx") == 0) {
91 		const struct got_error *err = NULL;
92 		char *path_pack;
93 		char base_path[PATH_MAX];
94 
95 		/* Convert pack index path to pack file path. */
96 		if (strlcpy(base_path, path, PATH_MAX) > PATH_MAX)
97 			return got_error(GOT_ERR_NO_SPACE);
98 		dot = strrchr(base_path, '.');
99 		if (dot == NULL)
100 			return got_error(GOT_ERR_BAD_PATH);
101 		*dot = '\0';
102 		if (asprintf(&path_pack, "%s.pack", base_path) == -1)
103 			return got_error_from_errno();
104 
105 		if (stat(path_pack, &sb) != 0)
106 			err = got_error_from_errno();
107 		free(path_pack);
108 		if (err)
109 			return err;
110 	} else if (strcmp(dot, ".pack") == 0) {
111 		if (stat(path, &sb) != 0)
112 			return got_error_from_errno();
113 	} else
114 		return got_error(GOT_ERR_BAD_PATH);
115 
116 	*size = sb.st_size;
117 	return 0;
118 }
119 
120 const struct got_error *
121 got_packidx_open(struct got_packidx_v2_hdr **packidx, const char *path)
122 {
123 	struct got_packidx_v2_hdr *p;
124 	FILE *f;
125 	const struct got_error *err = NULL;
126 	size_t n, nobj, packfile_size;
127 	SHA1_CTX ctx;
128 	uint8_t sha1[SHA1_DIGEST_LENGTH];
129 
130 	SHA1Init(&ctx);
131 
132 	f = fopen(path, "rb");
133 	if (f == NULL)
134 		return got_error_from_errno();
135 
136 	err = get_packfile_size(&packfile_size, path);
137 	if (err)
138 		return err;
139 
140 	p = calloc(1, sizeof(*p));
141 	if (p == NULL) {
142 		err = got_error_from_errno();
143 		goto done;
144 	}
145 
146 	n = fread(&p->magic, sizeof(p->magic), 1, f);
147 	if (n != 1) {
148 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
149 		goto done;
150 	}
151 
152 	if (betoh32(p->magic) != GOT_PACKIDX_V2_MAGIC) {
153 		err = got_error(GOT_ERR_BAD_PACKIDX);
154 		goto done;
155 	}
156 
157 	SHA1Update(&ctx, (uint8_t *)&p->magic, sizeof(p->magic));
158 
159 	n = fread(&p->version, sizeof(p->version), 1, f);
160 	if (n != 1) {
161 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
162 		goto done;
163 	}
164 
165 	if (betoh32(p->version) != GOT_PACKIDX_VERSION) {
166 		err = got_error(GOT_ERR_BAD_PACKIDX);
167 		goto done;
168 	}
169 
170 	SHA1Update(&ctx, (uint8_t *)&p->version, sizeof(p->version));
171 
172 	n = fread(&p->fanout_table, sizeof(p->fanout_table), 1, f);
173 	if (n != 1) {
174 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
175 		goto done;
176 	}
177 
178 	err = verify_fanout_table(p->fanout_table);
179 	if (err)
180 		goto done;
181 
182 	SHA1Update(&ctx, (uint8_t *)p->fanout_table, sizeof(p->fanout_table));
183 
184 	nobj = betoh32(p->fanout_table[0xff]);
185 
186 	p->sorted_ids = calloc(nobj, sizeof(*p->sorted_ids));
187 	if (p->sorted_ids == NULL) {
188 		err = got_error_from_errno();
189 		goto done;
190 	}
191 
192 	n = fread(p->sorted_ids, sizeof(*p->sorted_ids), nobj, f);
193 	if (n != nobj) {
194 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
195 		goto done;
196 	}
197 
198 	SHA1Update(&ctx, (uint8_t *)p->sorted_ids,
199 	    nobj * sizeof(*p->sorted_ids));
200 
201 	p->crc32 = calloc(nobj, sizeof(*p->crc32));
202 	if (p->crc32 == NULL) {
203 		err = got_error_from_errno();
204 		goto done;
205 	}
206 
207 	n = fread(p->crc32, sizeof(*p->crc32), nobj, f);
208 	if (n != nobj) {
209 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
210 		goto done;
211 	}
212 
213 	SHA1Update(&ctx, (uint8_t *)p->crc32, nobj * sizeof(*p->crc32));
214 
215 	p->offsets = calloc(nobj, sizeof(*p->offsets));
216 	if (p->offsets == NULL) {
217 		err = got_error_from_errno();
218 		goto done;
219 	}
220 
221 	n = fread(p->offsets, sizeof(*p->offsets), nobj, f);
222 	if (n != nobj) {
223 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
224 		goto done;
225 	}
226 
227 	SHA1Update(&ctx, (uint8_t *)p->offsets, nobj * sizeof(*p->offsets));
228 
229 	/* Large file offsets are contained only in files > 2GB. */
230 	if (packfile_size <= 0x80000000)
231 		goto checksum;
232 
233 	p->large_offsets = calloc(nobj, sizeof(*p->large_offsets));
234 	if (p->large_offsets == NULL) {
235 		err = got_error_from_errno();
236 		goto done;
237 	}
238 
239 	n = fread(p->large_offsets, sizeof(*p->large_offsets), nobj, f);
240 	if (n != nobj) {
241 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
242 		goto done;
243 	}
244 
245 	SHA1Update(&ctx, (uint8_t*)p->large_offsets,
246 	    nobj * sizeof(*p->large_offsets));
247 
248 checksum:
249 	n = fread(&p->trailer, sizeof(p->trailer), 1, f);
250 	if (n != 1) {
251 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
252 		goto done;
253 	}
254 
255 	SHA1Update(&ctx, p->trailer.packfile_sha1, SHA1_DIGEST_LENGTH);
256 	SHA1Final(sha1, &ctx);
257 	if (memcmp(p->trailer.packidx_sha1, sha1, SHA1_DIGEST_LENGTH) != 0)
258 		err = got_error(GOT_ERR_PACKIDX_CSUM);
259 done:
260 	fclose(f);
261 	if (err)
262 		got_packidx_close(p);
263 	else
264 		*packidx = p;
265 	return err;
266 }
267 
268 void
269 got_packidx_close(struct got_packidx_v2_hdr *packidx)
270 {
271 	free(packidx->sorted_ids);
272 	free(packidx->offsets);
273 	free(packidx->crc32);
274 	free(packidx->large_offsets);
275 	free(packidx);
276 }
277 
278 static int
279 is_packidx_filename(const char *name, size_t len)
280 {
281 	if (len != GOT_PACKIDX_NAMELEN)
282 		return 0;
283 
284 	if (strncmp(name, GOT_PACK_PREFIX, strlen(GOT_PACK_PREFIX)) != 0)
285 		return 0;
286 
287 	if (strcmp(name + strlen(GOT_PACK_PREFIX) +
288 	    SHA1_DIGEST_STRING_LENGTH - 1, GOT_PACKIDX_SUFFIX) != 0)
289 		return 0;
290 
291 	return 1;
292 }
293 
294 static off_t
295 get_object_offset(struct got_packidx_v2_hdr *packidx, int idx)
296 {
297 	uint32_t totobj = betoh32(packidx->fanout_table[0xff]);
298 	uint32_t offset = betoh32(packidx->offsets[idx]);
299 	if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
300 		uint64_t loffset;
301 		idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
302 		if (idx < 0 || idx > totobj || packidx->large_offsets == NULL)
303 			return -1;
304 		loffset = betoh64(packidx->large_offsets[idx]);
305 		return (loffset > INT64_MAX ? -1 : (off_t)loffset);
306 	}
307 	return (off_t)(offset & GOT_PACKIDX_OFFSET_VAL_MASK);
308 }
309 
310 static const struct got_error *
311 get_packfile_path(char **path_packfile, struct got_repository *repo,
312     struct got_packidx_v2_hdr *packidx);
313 
314 static int
315 get_object_idx(struct got_packidx_v2_hdr *packidx, struct got_object_id *id, struct got_repository *repo)
316 {
317 	u_int8_t id0 = id->sha1[0];
318 	uint32_t totobj = betoh32(packidx->fanout_table[0xff]);
319 	int i = 0;
320 
321 	if (id0 > 0)
322 		i = betoh32(packidx->fanout_table[id0 - 1]);
323 
324 	while (i < totobj) {
325 		struct got_object_id *oid = &packidx->sorted_ids[i];
326 		int cmp = got_object_id_cmp(id, oid);
327 
328 		if (cmp == 0)
329 			return i;
330 		i++;
331 	}
332 
333 	return -1;
334 }
335 
336 static struct got_packidx_v2_hdr *
337 dup_packidx(struct got_packidx_v2_hdr *packidx)
338 {
339 	struct got_packidx_v2_hdr *p;
340 	size_t nobj;
341 
342 	p = calloc(1, sizeof(*p));
343 	if (p == NULL)
344 		return NULL;
345 
346 	memcpy(p, packidx, sizeof(*p));
347 	p->sorted_ids = NULL;
348 	p->crc32 = NULL;
349 	p->offsets = NULL;
350 	p->large_offsets = NULL;
351 
352 	nobj = betoh32(p->fanout_table[0xff]);
353 
354 	p->sorted_ids = calloc(nobj, sizeof(*p->sorted_ids));
355 	if (p->sorted_ids == NULL)
356 		goto err;
357 	memcpy(p->sorted_ids, packidx->sorted_ids,
358 	    nobj * sizeof(*p->sorted_ids));
359 
360 	p->crc32 = calloc(nobj, sizeof(*p->crc32));
361 	if (p->crc32 == NULL)
362 		goto err;
363 	memcpy(p->crc32, packidx->crc32, nobj * sizeof(*p->crc32));
364 
365 	p->offsets = calloc(nobj, sizeof(*p->offsets));
366 	if (p->offsets == NULL)
367 		goto err;
368 	memcpy(p->offsets, packidx->offsets, nobj * sizeof(*p->offsets));
369 
370 	if (p->large_offsets) {
371 		p->large_offsets = calloc(nobj, sizeof(*p->large_offsets));
372 		if (p->large_offsets == NULL)
373 			goto err;
374 		memcpy(p->large_offsets, packidx->large_offsets,
375 		    nobj * sizeof(*p->large_offsets));
376 	}
377 
378 	return p;
379 
380 err:
381 	free(p->large_offsets);
382 	free(p->offsets);
383 	free(p->crc32);
384 	free(p->sorted_ids);
385 	free(p);
386 	return NULL;
387 }
388 
389 static void
390 cache_packidx(struct got_packidx_v2_hdr *packidx, struct got_repository *repo)
391 {
392 	int i;
393 
394 	for (i = 0; i < nitems(repo->packidx_cache); i++) {
395 		if (repo->packidx_cache[i] == NULL)
396 			break;
397 	}
398 
399 	if (i == nitems(repo->packidx_cache)) {
400 		got_packidx_close(repo->packidx_cache[i - 1]);
401 		memmove(&repo->packidx_cache[1], &repo->packidx_cache[0],
402 		    sizeof(repo->packidx_cache) -
403 		    sizeof(repo->packidx_cache[0]));
404 		i = 0;
405 	}
406 
407 	repo->packidx_cache[i] = dup_packidx(packidx);
408 }
409 
410 static const struct got_error *
411 search_packidx(struct got_packidx_v2_hdr **packidx, int *idx,
412     struct got_repository *repo, struct got_object_id *id)
413 {
414 	const struct got_error *err;
415 	char *path_packdir;
416 	DIR *packdir;
417 	struct dirent *dent;
418 	char *path_packidx;
419 	int i;
420 
421 	/* Search pack index cache. */
422 	for (i = 0; i < nitems(repo->packidx_cache); i++) {
423 		if (repo->packidx_cache[i] == NULL)
424 			break;
425 		*idx = get_object_idx(repo->packidx_cache[i], id, repo);
426 		if (*idx != -1) {
427 			*packidx = repo->packidx_cache[i];
428 			return NULL;
429 		}
430 	}
431 	/* No luck. Search the filesystem. */
432 
433 	path_packdir = got_repo_get_path_objects_pack(repo);
434 	if (path_packdir == NULL)
435 		return got_error_from_errno();
436 
437 	packdir = opendir(path_packdir);
438 	if (packdir == NULL) {
439 		err = got_error_from_errno();
440 		goto done;
441 	}
442 
443 	while ((dent = readdir(packdir)) != NULL) {
444 		if (!is_packidx_filename(dent->d_name, dent->d_namlen))
445 			continue;
446 
447 		if (asprintf(&path_packidx, "%s/%s", path_packdir,
448 		    dent->d_name) == -1) {
449 			err = got_error_from_errno();
450 			goto done;
451 		}
452 
453 		err = got_packidx_open(packidx, path_packidx);
454 		free(path_packidx);
455 		if (err)
456 			goto done;
457 
458 		*idx = get_object_idx(*packidx, id, repo);
459 		if (*idx != -1) {
460 			err = NULL; /* found the object */
461 			cache_packidx(*packidx, repo);
462 			goto done;
463 		}
464 
465 		got_packidx_close(*packidx);
466 		*packidx = NULL;
467 	}
468 
469 	err = got_error(GOT_ERR_NO_OBJ);
470 done:
471 	free(path_packdir);
472 	if (packdir && closedir(packdir) != 0 && err == 0)
473 		err = got_error_from_errno();
474 	return err;
475 }
476 
477 static const struct got_error *
478 get_packfile_path(char **path_packfile, struct got_repository *repo,
479     struct got_packidx_v2_hdr *packidx)
480 {
481 	char *path_packdir;
482 	char hex[SHA1_DIGEST_STRING_LENGTH];
483 	char *sha1str;
484 
485 	path_packdir = got_repo_get_path_objects_pack(repo);
486 	if (path_packdir == NULL)
487 		return got_error_from_errno();
488 
489 	sha1str = got_sha1_digest_to_str(packidx->trailer.packfile_sha1,
490 	    hex, sizeof(hex));
491 	if (sha1str == NULL)
492 		return got_error(GOT_ERR_PACKIDX_CSUM);
493 
494 	if (asprintf(path_packfile, "%s/%s%s%s", path_packdir,
495 	    GOT_PACK_PREFIX, sha1str, GOT_PACKFILE_SUFFIX) == -1) {
496 		*path_packfile = NULL;
497 		return got_error_from_errno();
498 	}
499 
500 	return NULL;
501 }
502 
503 const struct got_error *
504 read_packfile_hdr(int fd, struct got_packidx_v2_hdr *packidx)
505 {
506 	const struct got_error *err = NULL;
507 	uint32_t totobj = betoh32(packidx->fanout_table[0xff]);
508 	struct got_packfile_hdr hdr;
509 	ssize_t n;
510 
511 	n = read(fd, &hdr, sizeof(hdr));
512 	if (n < 0)
513 		return got_error_from_errno();
514 	if (n != sizeof(hdr))
515 		return got_error(GOT_ERR_BAD_PACKFILE);
516 
517 	if (betoh32(hdr.signature) != GOT_PACKFILE_SIGNATURE ||
518 	    betoh32(hdr.version) != GOT_PACKFILE_VERSION ||
519 	    betoh32(hdr.nobjects) != totobj)
520 		err = got_error(GOT_ERR_BAD_PACKFILE);
521 
522 	return err;
523 }
524 
525 static const struct got_error *
526 open_packfile(int *fd, const char *path_packfile,
527     struct got_repository *repo, struct got_packidx_v2_hdr *packidx)
528 {
529 	const struct got_error *err = NULL;
530 
531 	*fd = open(path_packfile, O_RDONLY | O_NOFOLLOW, GOT_DEFAULT_FILE_MODE);
532 	if (*fd == -1)
533 		return got_error_from_errno();
534 
535 	if (packidx) {
536 		err = read_packfile_hdr(*fd, packidx);
537 		if (err) {
538 			close(*fd);
539 			*fd = -1;
540 		}
541 	}
542 	return err;
543 }
544 
545 void
546 got_pack_close(struct got_pack *pack)
547 {
548 	close(pack->fd);
549 	pack->fd = -1;
550 	free(pack->path_packfile);
551 	pack->path_packfile = NULL;
552 	pack->filesize = 0;
553 }
554 
555 static const struct got_error *
556 cache_pack(struct got_pack **packp, const char *path_packfile,
557     struct got_packidx_v2_hdr *packidx, struct got_repository *repo)
558 {
559 	const struct got_error *err = NULL;
560 	struct got_pack *pack = NULL;
561 	int i;
562 
563 	if (packp)
564 		*packp = NULL;
565 
566 	for (i = 0; i < nitems(repo->packs); i++) {
567 		pack = &repo->packs[i];
568 		if (pack->path_packfile == NULL)
569 			break;
570 		if (strcmp(pack->path_packfile, path_packfile) == 0)
571 			return NULL;
572 	}
573 
574 	if (i == nitems(repo->packs) - 1) {
575 		got_pack_close(&repo->packs[i - 1]);
576 		memmove(&repo->packs[1], &repo->packs[0],
577 		    sizeof(repo->packs) - sizeof(repo->packs[0]));
578 		i = 0;
579 	}
580 
581 	pack = &repo->packs[i];
582 
583 	pack->path_packfile = strdup(path_packfile);
584 	if (pack->path_packfile == NULL) {
585 		err = got_error_from_errno();
586 		goto done;
587 	}
588 
589 	err = open_packfile(&pack->fd, path_packfile, repo, packidx);
590 	if (err)
591 		goto done;
592 
593 	err = get_packfile_size(&pack->filesize, path_packfile);
594 done:
595 	if (err) {
596 		if (pack) {
597 			free(pack->path_packfile);
598 			memset(pack, 0, sizeof(*pack));
599 		}
600 	} else if (packp)
601 		*packp = pack;
602 	return err;
603 }
604 
605 struct got_pack *
606 get_cached_pack(const char *path_packfile, struct got_repository *repo)
607 {
608 	struct got_pack *pack = NULL;
609 	int i;
610 
611 	for (i = 0; i < nitems(repo->packs); i++) {
612 		pack = &repo->packs[i];
613 		if (pack->path_packfile == NULL)
614 			break;
615 		if (strcmp(pack->path_packfile, path_packfile) == 0)
616 			return pack;
617 	}
618 
619 	return NULL;
620 }
621 
622 static const struct got_error *
623 parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len, int fd)
624 {
625 	uint8_t t = 0;
626 	uint64_t s = 0;
627 	uint8_t sizeN;
628 	ssize_t n;
629 	int i = 0;
630 
631 	do {
632 		/* We do not support size values which don't fit in 64 bit. */
633 		if (i > 9)
634 			return got_error(GOT_ERR_NO_SPACE);
635 
636 		n = read(fd, &sizeN, sizeof(sizeN));
637 		if (n < 0)
638 			return got_error_from_errno();
639 		if (n != sizeof(sizeN))
640 			return got_error(GOT_ERR_BAD_PACKFILE);
641 
642 		if (i == 0) {
643 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
644 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
645 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
646 		} else {
647 			size_t shift = 4 + 7 * (i - 1);
648 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
649 		}
650 		i++;
651 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
652 
653 	*type = t;
654 	*size = s;
655 	*len = i * sizeof(sizeN);
656 	return NULL;
657 }
658 
659 static const struct got_error *
660 open_plain_object(struct got_object **obj, const char *path_packfile,
661     struct got_object_id *id, uint8_t type, off_t offset, size_t size)
662 {
663 	*obj = calloc(1, sizeof(**obj));
664 	if (*obj == NULL)
665 		return got_error_from_errno();
666 
667 	(*obj)->path_packfile = strdup(path_packfile);
668 	if ((*obj)->path_packfile == NULL) {
669 		const struct got_error *err = got_error_from_errno();
670 		free(*obj);
671 		*obj = NULL;
672 		return err;
673 	}
674 
675 	(*obj)->type = type;
676 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
677 	(*obj)->hdrlen = 0;
678 	(*obj)->size = size;
679 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
680 	(*obj)->pack_offset = offset;
681 
682 	return NULL;
683 }
684 
685 static const struct got_error *
686 parse_negative_offset(int64_t *offset, size_t *len, int fd)
687 {
688 	int64_t o = 0;
689 	uint8_t offN;
690 	ssize_t n;
691 	int i = 0;
692 
693 	do {
694 		/* We do not support offset values which don't fit in 64 bit. */
695 		if (i > 8)
696 			return got_error(GOT_ERR_NO_SPACE);
697 
698 		n = read(fd, &offN, sizeof(offN));
699 		if (n < 0)
700 			return got_error_from_errno();
701 		if (n != sizeof(offN))
702 			return got_error(GOT_ERR_BAD_PACKFILE);
703 
704 		if (i == 0)
705 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
706 		else {
707 			o++;
708 			o <<= 7;
709 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
710 		}
711 		i++;
712 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
713 
714 	*offset = o;
715 	*len = i * sizeof(offN);
716 	return NULL;
717 }
718 
719 static const struct got_error *
720 parse_offset_delta(off_t *base_offset, int fd, off_t offset)
721 {
722 	const struct got_error *err;
723 	int64_t negoffset;
724 	size_t negofflen;
725 
726 	err = parse_negative_offset(&negoffset, &negofflen, fd);
727 	if (err)
728 		return err;
729 
730 	/* Compute the base object's offset (must be in the same pack file). */
731 	*base_offset = (offset - negoffset);
732 	if (*base_offset <= 0)
733 		return got_error(GOT_ERR_BAD_PACKFILE);
734 
735 	return NULL;
736 }
737 
738 static const struct got_error *
739 resolve_delta_chain(struct got_delta_chain *, struct got_repository *,
740     int, size_t, const char *, off_t, size_t, int, size_t, unsigned int);
741 
742 static const struct got_error *
743 add_delta(struct got_delta_chain *deltas, const char *path_packfile,
744     off_t delta_offset, size_t tslen, int delta_type, size_t delta_size,
745     size_t delta_data_offset, uint8_t *delta_buf, size_t delta_len)
746 {
747 	struct got_delta *delta;
748 
749 	delta = got_delta_open(path_packfile, delta_offset, tslen,
750 	    delta_type, delta_size, delta_data_offset, delta_buf,
751 	    delta_len);
752 	if (delta == NULL)
753 		return got_error_from_errno();
754 	/* delta is freed in got_object_close() */
755 	deltas->nentries++;
756 	SIMPLEQ_INSERT_HEAD(&deltas->entries, delta, entry);
757 	return NULL;
758 }
759 
760 static const struct got_error *
761 resolve_offset_delta(struct got_delta_chain *deltas,
762     struct got_repository *repo, int fd, size_t packfile_size,
763     const char *path_packfile, off_t delta_offset, size_t tslen,
764     int delta_type, size_t delta_size, unsigned int recursion)
765 
766 {
767 	const struct got_error *err;
768 	off_t base_offset;
769 	uint8_t base_type;
770 	uint64_t base_size;
771 	size_t base_tslen;
772 	off_t delta_data_offset;
773 	uint8_t *delta_buf;
774 	size_t delta_len;
775 
776 	err = parse_offset_delta(&base_offset, fd, delta_offset);
777 	if (err)
778 		return err;
779 
780 	delta_data_offset = lseek(fd, 0, SEEK_CUR);
781 	if (delta_data_offset == -1)
782 		return got_error_from_errno();
783 
784 	err = got_inflate_to_mem_fd(&delta_buf, &delta_len, fd);
785 	if (err)
786 		return err;
787 
788 	err = add_delta(deltas, path_packfile, delta_offset, tslen,
789 	    delta_type, delta_size, delta_data_offset, delta_buf, delta_len);
790 	if (err)
791 		return err;
792 
793 	/* An offset delta must be in the same packfile. */
794 	if (base_offset >= packfile_size)
795 		return got_error(GOT_ERR_PACK_OFFSET);
796 	if (lseek(fd, base_offset, SEEK_SET) == -1)
797 		return got_error_from_errno();
798 
799 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
800 	    fd);
801 	if (err)
802 		return err;
803 
804 	return resolve_delta_chain(deltas, repo, fd, packfile_size,
805 	    path_packfile, base_offset, base_tslen, base_type, base_size,
806 	    recursion - 1);
807 }
808 
809 static const struct got_error *
810 resolve_ref_delta(struct got_delta_chain *deltas, struct got_repository *repo,
811     int fd, const char *path_packfile, off_t delta_offset,
812     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
813 {
814 	const struct got_error *err;
815 	struct got_object_id id;
816 	struct got_packidx_v2_hdr *packidx;
817 	int idx;
818 	off_t base_offset;
819 	uint8_t base_type;
820 	uint64_t base_size;
821 	size_t base_tslen;
822 	ssize_t n;
823 	char *path_base_packfile;
824 	struct got_pack *base_pack;
825 	off_t delta_data_offset;
826 	uint8_t *delta_buf;
827 	size_t delta_len;
828 
829 	n = read(fd, &id, sizeof(id));
830 	if (n < 0)
831 		return got_error_from_errno();
832 	if (n != sizeof(id))
833 		return got_error(GOT_ERR_BAD_PACKFILE);
834 
835 	delta_data_offset = lseek(fd, 0, SEEK_CUR);
836 	if (delta_data_offset == -1)
837 		return got_error_from_errno();
838 
839 	err = got_inflate_to_mem_fd(&delta_buf, &delta_len, fd);
840 	if (err)
841 		return err;
842 
843 	err = add_delta(deltas, path_packfile, delta_offset, tslen,
844 	    delta_type, delta_size, delta_data_offset, delta_buf, delta_len);
845 	if (err)
846 		return err;
847 
848 	err = search_packidx(&packidx, &idx, repo, &id);
849 	if (err)
850 		return err;
851 
852 	base_offset = get_object_offset(packidx, idx);
853 	if (base_offset == (uint64_t)-1) {
854 		return got_error(GOT_ERR_BAD_PACKIDX);
855 	}
856 
857 	err = get_packfile_path(&path_base_packfile, repo, packidx);
858 	if (err)
859 		return err;
860 
861 	base_pack = get_cached_pack(path_base_packfile, repo);
862 	if (base_pack == NULL) {
863 		err = cache_pack(&base_pack, path_base_packfile, NULL, repo);
864 		if (err)
865 			goto done;
866 	}
867 
868 	if (base_offset >= base_pack->filesize) {
869 		err = got_error(GOT_ERR_PACK_OFFSET);
870 		goto done;
871 	}
872 	if (lseek(base_pack->fd, base_offset, SEEK_SET) == -1) {
873 		err = got_error_from_errno();
874 		goto done;
875 	}
876 
877 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
878 	    base_pack->fd);
879 	if (err)
880 		goto done;
881 
882 	err = resolve_delta_chain(deltas, repo, base_pack->fd,
883 	    base_pack->filesize, path_base_packfile, base_offset,
884 	    base_tslen, base_type, base_size, recursion - 1);
885 done:
886 	free(path_base_packfile);
887 	return err;
888 }
889 
890 static const struct got_error *
891 resolve_delta_chain(struct got_delta_chain *deltas, struct got_repository *repo,
892     int fd, size_t packfile_size, const char *path_packfile, off_t delta_offset,
893     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
894 {
895 	const struct got_error *err = NULL;
896 
897 	if (--recursion == 0)
898 		return got_error(GOT_ERR_RECURSION);
899 
900 	switch (delta_type) {
901 	case GOT_OBJ_TYPE_COMMIT:
902 	case GOT_OBJ_TYPE_TREE:
903 	case GOT_OBJ_TYPE_BLOB:
904 	case GOT_OBJ_TYPE_TAG:
905 		/* Plain types are the final delta base. Recursion ends. */
906 		err = add_delta(deltas, path_packfile, delta_offset, tslen,
907 		    delta_type, delta_size, 0, NULL, 0);
908 		break;
909 	case GOT_OBJ_TYPE_OFFSET_DELTA:
910 		err = resolve_offset_delta(deltas, repo, fd, packfile_size,
911 		    path_packfile, delta_offset, tslen, delta_type, delta_size,
912 		    recursion - 1);
913 		break;
914 	case GOT_OBJ_TYPE_REF_DELTA:
915 		err = resolve_ref_delta(deltas, repo, fd, path_packfile,
916 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
917 		break;
918 	default:
919 		return got_error(GOT_ERR_OBJ_TYPE);
920 	}
921 
922 	return err;
923 }
924 
925 static const struct got_error *
926 open_delta_object(struct got_object **obj, struct got_repository *repo,
927     struct got_packidx_v2_hdr *packidx, const char *path_packfile,
928     int fd, size_t packfile_size, struct got_object_id *id, off_t offset,
929     size_t tslen, int delta_type, size_t delta_size)
930 {
931 	const struct got_error *err = NULL;
932 	int resolved_type;
933 
934 	*obj = calloc(1, sizeof(**obj));
935 	if (*obj == NULL)
936 		return got_error_from_errno();
937 
938 	(*obj)->flags = 0;
939 	(*obj)->hdrlen = 0;
940 	(*obj)->size = 0; /* Not known because deltas aren't applied yet. */
941 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
942 	(*obj)->pack_offset = offset + tslen;
943 
944 	(*obj)->path_packfile = strdup(path_packfile);
945 	if ((*obj)->path_packfile == NULL) {
946 		err = got_error_from_errno();
947 		goto done;
948 	}
949 	(*obj)->flags |= GOT_OBJ_FLAG_PACKED;
950 
951 	SIMPLEQ_INIT(&(*obj)->deltas.entries);
952 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
953 
954 	err = resolve_delta_chain(&(*obj)->deltas, repo, fd, packfile_size,
955 	    path_packfile, offset, tslen, delta_type, delta_size,
956 	    GOT_DELTA_CHAIN_RECURSION_MAX);
957 	if (err)
958 		goto done;
959 
960 	err = got_delta_chain_get_base_type(&resolved_type, &(*obj)->deltas);
961 	if (err)
962 		goto done;
963 	(*obj)->type = resolved_type;
964 
965 done:
966 	if (err) {
967 		got_object_close(*obj);
968 		*obj = NULL;
969 	}
970 	return err;
971 }
972 
973 static const struct got_error *
974 open_packed_object(struct got_object **obj, struct got_repository *repo,
975     struct got_packidx_v2_hdr *packidx, int idx, struct got_object_id *id)
976 {
977 	const struct got_error *err = NULL;
978 	off_t offset;
979 	char *path_packfile;
980 	struct got_pack *pack;
981 	uint8_t type;
982 	uint64_t size;
983 	size_t tslen;
984 
985 	*obj = NULL;
986 
987 	offset = get_object_offset(packidx, idx);
988 	if (offset == (uint64_t)-1)
989 		return got_error(GOT_ERR_BAD_PACKIDX);
990 
991 	err = get_packfile_path(&path_packfile, repo, packidx);
992 	if (err)
993 		return err;
994 
995 	pack = get_cached_pack(path_packfile, repo);
996 	if (pack == NULL) {
997 		err = cache_pack(&pack, path_packfile, packidx, repo);
998 		if (err)
999 			goto done;
1000 	}
1001 
1002 	if (offset >= pack->filesize) {
1003 		err = got_error(GOT_ERR_PACK_OFFSET);
1004 		goto done;
1005 	}
1006 	if (lseek(pack->fd, offset, SEEK_SET) == -1) {
1007 		err = got_error_from_errno();
1008 		goto done;
1009 	}
1010 
1011 	err = parse_object_type_and_size(&type, &size, &tslen, pack->fd);
1012 	if (err)
1013 		goto done;
1014 
1015 	switch (type) {
1016 	case GOT_OBJ_TYPE_COMMIT:
1017 	case GOT_OBJ_TYPE_TREE:
1018 	case GOT_OBJ_TYPE_BLOB:
1019 	case GOT_OBJ_TYPE_TAG:
1020 		err = open_plain_object(obj, path_packfile, id, type,
1021 		    offset + tslen, size);
1022 		break;
1023 
1024 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1025 	case GOT_OBJ_TYPE_REF_DELTA:
1026 		err = open_delta_object(obj, repo, packidx, path_packfile,
1027 		    pack->fd, pack->filesize, id, offset, tslen, type, size);
1028 		break;
1029 
1030 	default:
1031 		err = got_error(GOT_ERR_OBJ_TYPE);
1032 		goto done;
1033 	}
1034 done:
1035 	free(path_packfile);
1036 	return err;
1037 }
1038 
1039 const struct got_error *
1040 got_packfile_open_object(struct got_object **obj, struct got_object_id *id,
1041     struct got_repository *repo)
1042 {
1043 	const struct got_error *err = NULL;
1044 	struct got_packidx_v2_hdr *packidx = NULL;
1045 	int idx;
1046 
1047 	err = search_packidx(&packidx, &idx, repo, id);
1048 	if (err)
1049 		return err;
1050 
1051 	err = open_packed_object(obj, repo, packidx, idx, id);
1052 	if (err)
1053 		return err;
1054 
1055 	err = cache_pack(NULL, (*obj)->path_packfile, packidx, repo);
1056 	return err;
1057 }
1058 
1059 static const struct got_error *
1060 get_delta_chain_max_size(uint64_t *max_size, struct got_delta_chain *deltas)
1061 {
1062 	struct got_delta *delta;
1063 	uint64_t base_size = 0, result_size = 0;
1064 
1065 	*max_size = 0;
1066 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1067 		/* Plain object types are the delta base. */
1068 		if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1069 		    delta->type != GOT_OBJ_TYPE_TREE &&
1070 		    delta->type != GOT_OBJ_TYPE_BLOB &&
1071 		    delta->type != GOT_OBJ_TYPE_TAG) {
1072 			const struct got_error *err;
1073 			err = got_delta_get_sizes(&base_size, &result_size,
1074 			    delta->delta_buf, delta->delta_len);
1075 			if (err)
1076 				return err;
1077 		} else
1078 			base_size = delta->size;
1079 		if (base_size > *max_size)
1080 			*max_size = base_size;
1081 		if (result_size > *max_size)
1082 			*max_size = result_size;
1083 	}
1084 
1085 	return NULL;
1086 }
1087 
1088 static const struct got_error *
1089 dump_delta_chain_to_file(size_t *result_size, struct got_delta_chain *deltas,
1090     FILE *outfile, struct got_repository *repo)
1091 {
1092 	const struct got_error *err = NULL;
1093 	struct got_delta *delta;
1094 	FILE *base_file = NULL, *accum_file = NULL;
1095 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1096 	size_t accum_size = 0;
1097 	uint64_t max_size;
1098 	int n = 0;
1099 
1100 	*result_size = 0;
1101 
1102 	if (SIMPLEQ_EMPTY(&deltas->entries))
1103 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1104 
1105 	/* We process small enough files entirely in memory for speed. */
1106 	err = get_delta_chain_max_size(&max_size, deltas);
1107 	if (err)
1108 		return err;
1109 	if (max_size < GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
1110 		accum_buf = malloc(max_size);
1111 		if (accum_buf == NULL)
1112 			return got_error_from_errno();
1113 	} else {
1114 		base_file = got_opentemp();
1115 		if (base_file == NULL)
1116 			return got_error_from_errno();
1117 
1118 		accum_file = got_opentemp();
1119 		if (accum_file == NULL) {
1120 			err = got_error_from_errno();
1121 			fclose(base_file);
1122 			return err;
1123 		}
1124 	}
1125 
1126 	/* Deltas are ordered in ascending order. */
1127 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1128 		if (n == 0) {
1129 			struct got_pack *pack;
1130 			size_t base_len;
1131 			off_t delta_data_offset;
1132 
1133 			/* Plain object types are the delta base. */
1134 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1135 			    delta->type != GOT_OBJ_TYPE_TREE &&
1136 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1137 			    delta->type != GOT_OBJ_TYPE_TAG) {
1138 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1139 				goto done;
1140 			}
1141 
1142 			pack = get_cached_pack(delta->path_packfile, repo);
1143 			if (pack == NULL) {
1144 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1145 				goto done;
1146 			}
1147 
1148 			delta_data_offset = delta->offset + delta->tslen;
1149 			if (delta_data_offset >= pack->filesize) {
1150 				err = got_error(GOT_ERR_PACK_OFFSET);
1151 				goto done;
1152 			}
1153 			if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1) {
1154 				err = got_error_from_errno();
1155 				goto done;
1156 			}
1157 			if (base_file)
1158 				err = got_inflate_to_file_fd(&base_len,
1159 				    pack->fd, base_file);
1160 			else {
1161 				err = got_inflate_to_mem_fd(&base_buf, &base_len,
1162 				    pack->fd);
1163 				if (base_len < max_size) {
1164 					uint8_t *p;
1165 					p = reallocarray(base_buf, 1, max_size);
1166 					if (p == NULL) {
1167 						err = got_error_from_errno();
1168 						goto done;
1169 					}
1170 					base_buf = p;
1171 				}
1172 			}
1173 			if (err)
1174 				goto done;
1175 			n++;
1176 			if (base_file)
1177 				rewind(base_file);
1178 			continue;
1179 		}
1180 
1181 		if (base_buf) {
1182 			err = got_delta_apply_in_mem(base_buf, delta->delta_buf,
1183 			    delta->delta_len, accum_buf, &accum_size);
1184 			n++;
1185 		} else {
1186 			err = got_delta_apply(base_file, delta->delta_buf,
1187 			    delta->delta_len,
1188 			    /* Final delta application writes to output file. */
1189 			    ++n < deltas->nentries ? accum_file : outfile,
1190 			    &accum_size);
1191 		}
1192 		if (err)
1193 			goto done;
1194 
1195 		if (n < deltas->nentries) {
1196 			/* Accumulated delta becomes the new base. */
1197 			if (base_buf) {
1198 				uint8_t *tmp = accum_buf;
1199 				accum_buf = base_buf;
1200 				base_buf = tmp;
1201 			} else {
1202 				FILE *tmp = accum_file;
1203 				accum_file = base_file;
1204 				base_file = tmp;
1205 				rewind(base_file);
1206 				rewind(accum_file);
1207 			}
1208 		}
1209 	}
1210 
1211 done:
1212 	free(base_buf);
1213 	if (accum_buf) {
1214 		size_t len = fwrite(accum_buf, 1, accum_size, outfile);
1215 		free(accum_buf);
1216 		if (len != accum_size)
1217 			return got_ferror(outfile, GOT_ERR_IO);
1218 	}
1219 	if (base_file)
1220 		fclose(base_file);
1221 	if (accum_file)
1222 		fclose(accum_file);
1223 	rewind(outfile);
1224 	if (err == NULL)
1225 		*result_size = accum_size;
1226 	return err;
1227 }
1228 
1229 static const struct got_error *
1230 dump_delta_chain_to_mem(uint8_t **outbuf, size_t *outlen,
1231     struct got_delta_chain *deltas, struct got_repository *repo)
1232 {
1233 	const struct got_error *err = NULL;
1234 	struct got_delta *delta;
1235 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1236 	size_t accum_size;
1237 	uint64_t max_size;
1238 	int n = 0;
1239 
1240 	*outbuf = NULL;
1241 	*outlen = 0;
1242 
1243 	if (SIMPLEQ_EMPTY(&deltas->entries))
1244 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1245 
1246 	err = get_delta_chain_max_size(&max_size, deltas);
1247 	if (err)
1248 		return err;
1249 	accum_buf = malloc(max_size);
1250 	if (accum_buf == NULL)
1251 		return got_error_from_errno();
1252 
1253 	/* Deltas are ordered in ascending order. */
1254 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1255 		if (n == 0) {
1256 			struct got_pack *pack;
1257 			size_t base_len;
1258 			size_t delta_data_offset;
1259 
1260 			/* Plain object types are the delta base. */
1261 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1262 			    delta->type != GOT_OBJ_TYPE_TREE &&
1263 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1264 			    delta->type != GOT_OBJ_TYPE_TAG) {
1265 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1266 				goto done;
1267 			}
1268 
1269 			pack = get_cached_pack(delta->path_packfile, repo);
1270 			if (pack == NULL) {
1271 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1272 				goto done;
1273 			}
1274 
1275 			delta_data_offset = delta->offset + delta->tslen;
1276 			if (delta_data_offset >= pack->filesize) {
1277 				err = got_error(GOT_ERR_PACK_OFFSET);
1278 				goto done;
1279 			}
1280 			if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1) {
1281 				err = got_error_from_errno();
1282 				goto done;
1283 			}
1284 			err = got_inflate_to_mem_fd(&base_buf, &base_len,
1285 			    pack->fd);
1286 			if (base_len < max_size) {
1287 				uint8_t *p;
1288 				p = reallocarray(base_buf, 1, max_size);
1289 				if (p == NULL) {
1290 					err = got_error_from_errno();
1291 					goto done;
1292 				}
1293 				base_buf = p;
1294 			}
1295 			if (err)
1296 				goto done;
1297 			n++;
1298 			continue;
1299 		}
1300 
1301 		err = got_delta_apply_in_mem(base_buf, delta->delta_buf,
1302 		    delta->delta_len, accum_buf, &accum_size);
1303 		n++;
1304 		if (err)
1305 			goto done;
1306 
1307 		if (n < deltas->nentries) {
1308 			/* Accumulated delta becomes the new base. */
1309 			uint8_t *tmp = accum_buf;
1310 			accum_buf = base_buf;
1311 			base_buf = tmp;
1312 		}
1313 	}
1314 
1315 done:
1316 	free(base_buf);
1317 	if (err) {
1318 		free(accum_buf);
1319 		*outbuf = NULL;
1320 		*outlen = 0;
1321 	} else {
1322 		*outbuf = accum_buf;
1323 		*outlen = accum_size;
1324 	}
1325 	return err;
1326 }
1327 
1328 const struct got_error *
1329 got_packfile_extract_object(FILE **f, struct got_object *obj,
1330     struct got_repository *repo)
1331 {
1332 	const struct got_error *err = NULL;
1333 
1334 	*f = NULL;
1335 
1336 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1337 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1338 
1339 	*f = got_opentemp();
1340 	if (*f == NULL) {
1341 		err = got_error_from_errno();
1342 		goto done;
1343 	}
1344 
1345 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1346 		struct got_pack *pack;
1347 
1348 		pack = get_cached_pack(obj->path_packfile, repo);
1349 		if (pack == NULL) {
1350 			err = cache_pack(&pack, obj->path_packfile, NULL, repo);
1351 			if (err)
1352 				goto done;
1353 		}
1354 
1355 		if (obj->pack_offset >= pack->filesize) {
1356 			err = got_error(GOT_ERR_PACK_OFFSET);
1357 			goto done;
1358 		}
1359 		if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1) {
1360 			err = got_error_from_errno();
1361 			goto done;
1362 		}
1363 
1364 		err = got_inflate_to_file_fd(&obj->size, pack->fd, *f);
1365 	} else
1366 		err = dump_delta_chain_to_file(&obj->size,
1367 		    &obj->deltas, *f, repo);
1368 done:
1369 	if (err && *f) {
1370 		fclose(*f);
1371 		*f = NULL;
1372 	}
1373 	return err;
1374 }
1375 
1376 const struct got_error *
1377 got_packfile_extract_object_to_mem(uint8_t **buf, size_t *len,
1378     struct got_object *obj, struct got_repository *repo)
1379 {
1380 	const struct got_error *err = NULL;
1381 
1382 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1383 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1384 
1385 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1386 		struct got_pack *pack;
1387 
1388 		pack = get_cached_pack(obj->path_packfile, repo);
1389 		if (pack == NULL) {
1390 			err = cache_pack(&pack, obj->path_packfile, NULL, repo);
1391 			if (err)
1392 				goto done;
1393 		}
1394 
1395 		if (obj->pack_offset >= pack->filesize) {
1396 			err = got_error(GOT_ERR_PACK_OFFSET);
1397 			goto done;
1398 		}
1399 		if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1) {
1400 			err = got_error_from_errno();
1401 			goto done;
1402 		}
1403 
1404 		err = got_inflate_to_mem_fd(buf, len, pack->fd);
1405 	} else
1406 		err = dump_delta_chain_to_mem(buf, len, &obj->deltas, repo);
1407 done:
1408 	return err;
1409 }