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Date:: Fri Jun 22 18:56:40 2018 UTC
Message:: wrap overlong lines
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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/mman.h>
21 
22 #include <dirent.h>
23 #include <fcntl.h>
24 #include <errno.h>
25 #include <stdio.h>
26 #include <stdint.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <limits.h>
30 #include <sha1.h>
31 #include <endian.h>
32 #include <zlib.h>
33 
34 #include "got_error.h"
35 #include "got_object.h"
36 #include "got_repository.h"
37 #include "got_opentemp.h"
38 
39 #include "got_lib_sha1.h"
40 #include "got_lib_pack.h"
41 #include "got_lib_path.h"
42 #include "got_lib_delta.h"
43 #include "got_lib_zbuf.h"
44 #include "got_lib_object.h"
45 #include "got_lib_repository.h"
46 
47 #ifndef nitems
48 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
49 #endif
50 
51 #define GOT_PACK_PREFIX		"pack-"
52 #define GOT_PACKFILE_SUFFIX	".pack"
53 #define GOT_PACKIDX_SUFFIX		".idx"
54 #define GOT_PACKFILE_NAMELEN	(strlen(GOT_PACK_PREFIX) + \
55 				SHA1_DIGEST_STRING_LENGTH - 1 + \
56 				strlen(GOT_PACKFILE_SUFFIX))
57 #define GOT_PACKIDX_NAMELEN	(strlen(GOT_PACK_PREFIX) + \
58 				SHA1_DIGEST_STRING_LENGTH - 1 + \
59 				strlen(GOT_PACKIDX_SUFFIX))
60 
61 #ifndef MIN
62 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
63 #endif
64 
65 static const struct got_error *
66 verify_fanout_table(uint32_t *fanout_table)
67 {
68 	int i;
69 
70 	for (i = 0; i < 0xff - 1; i++) {
71 		if (be32toh(fanout_table[i]) > be32toh(fanout_table[i + 1]))
72 			return got_error(GOT_ERR_BAD_PACKIDX);
73 	}
74 
75 	return NULL;
76 }
77 
78 static const struct got_error *
79 get_packfile_size(size_t *size, const char *path)
80 {
81 	struct stat sb;
82 	char *dot;
83 
84 	*size = 0;
85 
86 	dot = strrchr(path, '.');
87 	if (dot == NULL)
88 		return got_error(GOT_ERR_BAD_PATH);
89 
90 	/* Path must point to a pack index or to a pack file. */
91 	if (strcmp(dot, GOT_PACKIDX_SUFFIX) == 0) {
92 		const struct got_error *err = NULL;
93 		char *path_pack;
94 		char base_path[PATH_MAX];
95 
96 		/* Convert pack index path to pack file path. */
97 		if (strlcpy(base_path, path, PATH_MAX) > PATH_MAX)
98 			return got_error(GOT_ERR_NO_SPACE);
99 		dot = strrchr(base_path, '.');
100 		if (dot == NULL)
101 			return got_error(GOT_ERR_BAD_PATH);
102 		*dot = '\0';
103 		if (asprintf(&path_pack, "%s.pack", base_path) == -1)
104 			return got_error_from_errno();
105 
106 		if (stat(path_pack, &sb) != 0)
107 			err = got_error_from_errno();
108 		free(path_pack);
109 		if (err)
110 			return err;
111 	} else if (strcmp(dot, GOT_PACKFILE_SUFFIX) == 0) {
112 		if (stat(path, &sb) != 0)
113 			return got_error_from_errno();
114 	} else
115 		return got_error(GOT_ERR_BAD_PATH);
116 
117 	*size = sb.st_size;
118 	return 0;
119 }
120 
121 const struct got_error *
122 got_packidx_open(struct got_packidx **packidx, const char *path)
123 {
124 	struct got_packidx *p;
125 	struct got_packidx_v2_hdr *h;
126 	const struct got_error *err = NULL;
127 	size_t nobj, len_fanout, len_ids, offset, remain;
128 	SHA1_CTX ctx;
129 	uint8_t sha1[SHA1_DIGEST_LENGTH];
130 
131 	*packidx = NULL;
132 
133 	SHA1Init(&ctx);
134 
135 	p = calloc(1, sizeof(*p));
136 	if (p == NULL)
137 		return got_error_from_errno();
138 
139 	p->fd = open(path, O_RDONLY | O_NOFOLLOW, GOT_DEFAULT_FILE_MODE);
140 	if (p->fd == -1)
141 		return got_error_from_errno();
142 
143 	err = get_packfile_size(&p->len, path);
144 	if (err) {
145 		close(p->fd);
146 		free(p);
147 		return err;
148 	}
149 	if (p->len < sizeof(p->hdr)) {
150 		err = got_error(GOT_ERR_BAD_PACKIDX);
151 		close(p->fd);
152 		free(p);
153 		return err;
154 	}
155 
156 	p->path_packidx = strdup(path);
157 	if (p->path_packidx == NULL) {
158 		err = got_error_from_errno();
159 		goto done;
160 	}
161 
162 	p->map = mmap(NULL, p->len, PROT_READ, MAP_PRIVATE, p->fd, 0);
163 	if (p->map == MAP_FAILED) {
164 		err = got_error_from_errno();
165 		goto done;
166 	}
167 	h = &p->hdr;
168 	offset = 0;
169 	remain = p->len;
170 
171 	if (remain < sizeof(*h->magic)) {
172 		err = got_error(GOT_ERR_BAD_PACKIDX);
173 		goto done;
174 	}
175 	h->magic = (uint32_t *)(p->map + offset);
176 	if (betoh32(*h->magic) != GOT_PACKIDX_V2_MAGIC) {
177 		err = got_error(GOT_ERR_BAD_PACKIDX);
178 		goto done;
179 	}
180 	offset += sizeof(*h->magic);
181 	remain -= sizeof(*h->magic);
182 
183 	SHA1Update(&ctx, (uint8_t *)h->magic, sizeof(*h->magic));
184 
185 	if (remain < sizeof(*h->version)) {
186 		err = got_error(GOT_ERR_BAD_PACKIDX);
187 		goto done;
188 	}
189 	h->version = (uint32_t *)(p->map + offset);
190 	if (betoh32(*h->version) != GOT_PACKIDX_VERSION) {
191 		err = got_error(GOT_ERR_BAD_PACKIDX);
192 		goto done;
193 	}
194 	offset += sizeof(*h->version);
195 	remain -= sizeof(*h->version);
196 
197 	SHA1Update(&ctx, (uint8_t *)h->version, sizeof(*h->version));
198 
199 	len_fanout =
200 	    sizeof(*h->fanout_table) * GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS;
201 	if (remain < len_fanout) {
202 		err = got_error(GOT_ERR_BAD_PACKIDX);
203 		goto done;
204 	}
205 	h->fanout_table = (uint32_t *)(p->map + offset);
206 	err = verify_fanout_table(h->fanout_table);
207 	if (err)
208 		goto done;
209 	SHA1Update(&ctx, (uint8_t *)h->fanout_table, len_fanout);
210 	offset += len_fanout;
211 	remain -= len_fanout;
212 
213 	nobj = betoh32(h->fanout_table[0xff]);
214 	len_ids = nobj * sizeof(*h->sorted_ids);
215 	if (len_ids <= nobj || len_ids > remain) {
216 		err = got_error(GOT_ERR_BAD_PACKIDX);
217 		goto done;
218 	}
219 	h->sorted_ids =
220 	    (struct got_packidx_object_id *)((uint8_t*)(p->map + offset));
221 	SHA1Update(&ctx, (uint8_t *)h->sorted_ids, len_ids);
222 	offset += len_ids;
223 	remain -= len_ids;
224 
225 	if (remain < nobj * sizeof(*h->crc32)) {
226 		err = got_error(GOT_ERR_BAD_PACKIDX);
227 		goto done;
228 	}
229 	h->crc32 = (uint32_t *)((uint8_t*)(p->map + offset));
230 	SHA1Update(&ctx, (uint8_t *)h->crc32, nobj * sizeof(*h->crc32));
231 	remain -= nobj * sizeof(*h->crc32);
232 	offset += nobj * sizeof(*h->crc32);
233 
234 	if (remain < nobj * sizeof(*h->offsets)) {
235 		err = got_error(GOT_ERR_BAD_PACKIDX);
236 		goto done;
237 	}
238 	h->offsets = (uint32_t *)((uint8_t*)(p->map + offset));
239 	SHA1Update(&ctx, (uint8_t *)h->offsets, nobj * sizeof(*h->offsets));
240 	remain -= nobj * sizeof(*h->offsets);
241 	offset += nobj * sizeof(*h->offsets);
242 
243 	/* Large file offsets are contained only in files > 2GB. */
244 	if (p->len <= 0x80000000)
245 		goto checksum;
246 
247 	if (remain < nobj * sizeof(*h->large_offsets)) {
248 		err = got_error(GOT_ERR_BAD_PACKIDX);
249 		goto done;
250 	}
251 	h->large_offsets = (uint64_t *)((uint8_t*)(p->map + offset));
252 	SHA1Update(&ctx, (uint8_t*)h->large_offsets,
253 	    nobj * sizeof(*h->large_offsets));
254 	remain -= nobj * sizeof(*h->large_offsets);
255 	offset += nobj * sizeof(*h->large_offsets);
256 
257 checksum:
258 	if (remain < sizeof(*h->trailer)) {
259 		err = got_error(GOT_ERR_BAD_PACKIDX);
260 		goto done;
261 	}
262 	h->trailer =
263 	    (struct got_packidx_trailer *)((uint8_t*)(p->map + offset));
264 	SHA1Update(&ctx, h->trailer->packfile_sha1, SHA1_DIGEST_LENGTH);
265 	SHA1Final(sha1, &ctx);
266 	if (memcmp(h->trailer->packidx_sha1, sha1, SHA1_DIGEST_LENGTH) != 0)
267 		err = got_error(GOT_ERR_PACKIDX_CSUM);
268 done:
269 	if (err)
270 		got_packidx_close(p);
271 	else
272 		*packidx = p;
273 	return err;
274 }
275 
276 const struct got_error *
277 got_packidx_close(struct got_packidx *packidx)
278 {
279 	const struct got_error *err = NULL;
280 
281 	free(packidx->path_packidx);
282 	if (packidx->map != NULL && packidx->map != MAP_FAILED) {
283 		if (munmap(packidx->map, packidx->len) == -1)
284 			err = got_error_from_errno();
285 	}
286 	close(packidx->fd);
287 	free(packidx);
288 
289 	return err;
290 }
291 
292 static int
293 is_packidx_filename(const char *name, size_t len)
294 {
295 	if (len != GOT_PACKIDX_NAMELEN)
296 		return 0;
297 
298 	if (strncmp(name, GOT_PACK_PREFIX, strlen(GOT_PACK_PREFIX)) != 0)
299 		return 0;
300 
301 	if (strcmp(name + strlen(GOT_PACK_PREFIX) +
302 	    SHA1_DIGEST_STRING_LENGTH - 1, GOT_PACKIDX_SUFFIX) != 0)
303 		return 0;
304 
305 	return 1;
306 }
307 
308 static off_t
309 get_object_offset(struct got_packidx *packidx, int idx)
310 {
311 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
312 	uint32_t offset = betoh32(packidx->hdr.offsets[idx]);
313 	if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
314 		uint64_t loffset;
315 		idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
316 		if (idx < 0 || idx > totobj ||
317 		    packidx->hdr.large_offsets == NULL)
318 			return -1;
319 		loffset = betoh64(packidx->hdr.large_offsets[idx]);
320 		return (loffset > INT64_MAX ? -1 : (off_t)loffset);
321 	}
322 	return (off_t)(offset & GOT_PACKIDX_OFFSET_VAL_MASK);
323 }
324 
325 static int
326 get_object_idx(struct got_packidx *packidx, struct got_object_id *id,
327     struct got_repository *repo)
328 {
329 	u_int8_t id0 = id->sha1[0];
330 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
331 	int left = 0, right = totobj - 1;
332 
333 	if (id0 > 0)
334 		left = betoh32(packidx->hdr.fanout_table[id0 - 1]);
335 
336 	while (left <= right) {
337 		struct got_packidx_object_id *oid;
338 		int i, cmp;
339 
340 		i = ((left + right) / 2);
341 		oid = &packidx->hdr.sorted_ids[i];
342 		cmp = memcmp(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
343 		if (cmp == 0)
344 			return i;
345 		else if (cmp > 0)
346 			left = i + 1;
347 		else if (cmp < 0)
348 			right = i - 1;
349 	}
350 
351 	return -1;
352 }
353 
354 static const struct got_error *
355 cache_packidx(struct got_packidx *packidx, struct got_repository *repo)
356 {
357 	const struct got_error *err = NULL;
358 	int i;
359 
360 	for (i = 0; i < nitems(repo->packidx_cache); i++) {
361 		if (repo->packidx_cache[i] == NULL)
362 			break;
363 	}
364 
365 	if (i == nitems(repo->packidx_cache)) {
366 		err = got_packidx_close(repo->packidx_cache[i - 1]);
367 		if (err)
368 			return err;
369 		memmove(&repo->packidx_cache[1], &repo->packidx_cache[0],
370 		    sizeof(repo->packidx_cache) -
371 		    sizeof(repo->packidx_cache[0]));
372 		i = 0;
373 	}
374 
375 	repo->packidx_cache[i] = packidx;
376 	return NULL;
377 }
378 
379 static const struct got_error *
380 search_packidx(struct got_packidx **packidx, int *idx,
381     struct got_repository *repo, struct got_object_id *id)
382 {
383 	const struct got_error *err;
384 	char *path_packdir;
385 	DIR *packdir;
386 	struct dirent *dent;
387 	char *path_packidx;
388 	int i;
389 
390 	/* Search pack index cache. */
391 	for (i = 0; i < nitems(repo->packidx_cache); i++) {
392 		if (repo->packidx_cache[i] == NULL)
393 			break;
394 		*idx = get_object_idx(repo->packidx_cache[i], id, repo);
395 		if (*idx != -1) {
396 			*packidx = repo->packidx_cache[i];
397 			return NULL;
398 		}
399 	}
400 	/* No luck. Search the filesystem. */
401 
402 	path_packdir = got_repo_get_path_objects_pack(repo);
403 	if (path_packdir == NULL)
404 		return got_error_from_errno();
405 
406 	packdir = opendir(path_packdir);
407 	if (packdir == NULL) {
408 		err = got_error_from_errno();
409 		goto done;
410 	}
411 
412 	while ((dent = readdir(packdir)) != NULL) {
413 		if (!is_packidx_filename(dent->d_name, dent->d_namlen))
414 			continue;
415 
416 		if (asprintf(&path_packidx, "%s/%s", path_packdir,
417 		    dent->d_name) == -1) {
418 			err = got_error_from_errno();
419 			goto done;
420 		}
421 
422 		err = got_packidx_open(packidx, path_packidx);
423 		free(path_packidx);
424 		if (err)
425 			goto done;
426 
427 		*idx = get_object_idx(*packidx, id, repo);
428 		if (*idx != -1) {
429 			err = NULL; /* found the object */
430 			err = cache_packidx(*packidx, repo);
431 			goto done;
432 		}
433 
434 		err = got_packidx_close(*packidx);
435 		*packidx = NULL;
436 		if (err)
437 			goto done;
438 	}
439 
440 	err = got_error(GOT_ERR_NO_OBJ);
441 done:
442 	free(path_packdir);
443 	if (packdir && closedir(packdir) != 0 && err == 0)
444 		err = got_error_from_errno();
445 	return err;
446 }
447 
448 static const struct got_error *
449 get_packfile_path(char **path_packfile, struct got_repository *repo,
450     struct got_packidx *packidx)
451 {
452 	size_t size;
453 
454 	/* Packfile path contains ".pack" instead of ".idx", so add one byte. */
455 	size = strlen(packidx->path_packidx) + 2;
456 	if (size < GOT_PACKFILE_NAMELEN + 1)
457 		return got_error(GOT_ERR_BAD_PATH);
458 
459 	*path_packfile = calloc(size, sizeof(**path_packfile));
460 	if (*path_packfile == NULL)
461 		return got_error_from_errno();
462 
463 	/* Copy up to and excluding ".idx". */
464 	if (strlcpy(*path_packfile, packidx->path_packidx,
465 	    size - strlen(GOT_PACKIDX_SUFFIX) - 1) >= size)
466 		return got_error(GOT_ERR_NO_SPACE);
467 
468 	if (strlcat(*path_packfile, GOT_PACKFILE_SUFFIX, size) >= size)
469 		return got_error(GOT_ERR_NO_SPACE);
470 
471 	return NULL;
472 }
473 
474 const struct got_error *
475 read_packfile_hdr(int fd, struct got_packidx *packidx)
476 {
477 	const struct got_error *err = NULL;
478 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
479 	struct got_packfile_hdr hdr;
480 	ssize_t n;
481 
482 	n = read(fd, &hdr, sizeof(hdr));
483 	if (n < 0)
484 		return got_error_from_errno();
485 	if (n != sizeof(hdr))
486 		return got_error(GOT_ERR_BAD_PACKFILE);
487 
488 	if (betoh32(hdr.signature) != GOT_PACKFILE_SIGNATURE ||
489 	    betoh32(hdr.version) != GOT_PACKFILE_VERSION ||
490 	    betoh32(hdr.nobjects) != totobj)
491 		err = got_error(GOT_ERR_BAD_PACKFILE);
492 
493 	return err;
494 }
495 
496 static const struct got_error *
497 open_packfile(int *fd, const char *path_packfile,
498     struct got_repository *repo, struct got_packidx *packidx)
499 {
500 	const struct got_error *err = NULL;
501 
502 	*fd = open(path_packfile, O_RDONLY | O_NOFOLLOW, GOT_DEFAULT_FILE_MODE);
503 	if (*fd == -1)
504 		return got_error_from_errno();
505 
506 	if (packidx) {
507 		err = read_packfile_hdr(*fd, packidx);
508 		if (err) {
509 			close(*fd);
510 			*fd = -1;
511 		}
512 	}
513 	return err;
514 }
515 
516 void
517 got_pack_close(struct got_pack *pack)
518 {
519 	close(pack->fd);
520 	pack->fd = -1;
521 	free(pack->path_packfile);
522 	pack->path_packfile = NULL;
523 	pack->filesize = 0;
524 }
525 
526 static const struct got_error *
527 cache_pack(struct got_pack **packp, const char *path_packfile,
528     struct got_packidx *packidx, struct got_repository *repo)
529 {
530 	const struct got_error *err = NULL;
531 	struct got_pack *pack = NULL;
532 	int i;
533 
534 	if (packp)
535 		*packp = NULL;
536 
537 	for (i = 0; i < nitems(repo->packs); i++) {
538 		pack = &repo->packs[i];
539 		if (pack->path_packfile == NULL)
540 			break;
541 		if (strcmp(pack->path_packfile, path_packfile) == 0)
542 			return NULL;
543 	}
544 
545 	if (i == nitems(repo->packs) - 1) {
546 		got_pack_close(&repo->packs[i - 1]);
547 		memmove(&repo->packs[1], &repo->packs[0],
548 		    sizeof(repo->packs) - sizeof(repo->packs[0]));
549 		i = 0;
550 	}
551 
552 	pack = &repo->packs[i];
553 
554 	pack->path_packfile = strdup(path_packfile);
555 	if (pack->path_packfile == NULL) {
556 		err = got_error_from_errno();
557 		goto done;
558 	}
559 
560 	err = open_packfile(&pack->fd, path_packfile, repo, packidx);
561 	if (err)
562 		goto done;
563 
564 	err = get_packfile_size(&pack->filesize, path_packfile);
565 done:
566 	if (err) {
567 		if (pack) {
568 			free(pack->path_packfile);
569 			memset(pack, 0, sizeof(*pack));
570 		}
571 	} else if (packp)
572 		*packp = pack;
573 	return err;
574 }
575 
576 struct got_pack *
577 get_cached_pack(const char *path_packfile, struct got_repository *repo)
578 {
579 	struct got_pack *pack = NULL;
580 	int i;
581 
582 	for (i = 0; i < nitems(repo->packs); i++) {
583 		pack = &repo->packs[i];
584 		if (pack->path_packfile == NULL)
585 			break;
586 		if (strcmp(pack->path_packfile, path_packfile) == 0)
587 			return pack;
588 	}
589 
590 	return NULL;
591 }
592 
593 static const struct got_error *
594 parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len, int fd)
595 {
596 	uint8_t t = 0;
597 	uint64_t s = 0;
598 	uint8_t sizeN;
599 	ssize_t n;
600 	int i = 0;
601 
602 	do {
603 		/* We do not support size values which don't fit in 64 bit. */
604 		if (i > 9)
605 			return got_error(GOT_ERR_NO_SPACE);
606 
607 		n = read(fd, &sizeN, sizeof(sizeN));
608 		if (n < 0)
609 			return got_error_from_errno();
610 		if (n != sizeof(sizeN))
611 			return got_error(GOT_ERR_BAD_PACKFILE);
612 
613 		if (i == 0) {
614 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
615 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
616 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
617 		} else {
618 			size_t shift = 4 + 7 * (i - 1);
619 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
620 		}
621 		i++;
622 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
623 
624 	*type = t;
625 	*size = s;
626 	*len = i * sizeof(sizeN);
627 	return NULL;
628 }
629 
630 static const struct got_error *
631 open_plain_object(struct got_object **obj, const char *path_packfile,
632     struct got_object_id *id, uint8_t type, off_t offset, size_t size)
633 {
634 	*obj = calloc(1, sizeof(**obj));
635 	if (*obj == NULL)
636 		return got_error_from_errno();
637 
638 	(*obj)->path_packfile = strdup(path_packfile);
639 	if ((*obj)->path_packfile == NULL) {
640 		const struct got_error *err = got_error_from_errno();
641 		free(*obj);
642 		*obj = NULL;
643 		return err;
644 	}
645 
646 	(*obj)->type = type;
647 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
648 	(*obj)->hdrlen = 0;
649 	(*obj)->size = size;
650 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
651 	(*obj)->pack_offset = offset;
652 
653 	return NULL;
654 }
655 
656 static const struct got_error *
657 parse_negative_offset(int64_t *offset, size_t *len, int fd)
658 {
659 	int64_t o = 0;
660 	uint8_t offN;
661 	ssize_t n;
662 	int i = 0;
663 
664 	do {
665 		/* We do not support offset values which don't fit in 64 bit. */
666 		if (i > 8)
667 			return got_error(GOT_ERR_NO_SPACE);
668 
669 		n = read(fd, &offN, sizeof(offN));
670 		if (n < 0)
671 			return got_error_from_errno();
672 		if (n != sizeof(offN))
673 			return got_error(GOT_ERR_BAD_PACKFILE);
674 
675 		if (i == 0)
676 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
677 		else {
678 			o++;
679 			o <<= 7;
680 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
681 		}
682 		i++;
683 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
684 
685 	*offset = o;
686 	*len = i * sizeof(offN);
687 	return NULL;
688 }
689 
690 static const struct got_error *
691 parse_offset_delta(off_t *base_offset, int fd, off_t offset)
692 {
693 	const struct got_error *err;
694 	int64_t negoffset;
695 	size_t negofflen;
696 
697 	err = parse_negative_offset(&negoffset, &negofflen, fd);
698 	if (err)
699 		return err;
700 
701 	/* Compute the base object's offset (must be in the same pack file). */
702 	*base_offset = (offset - negoffset);
703 	if (*base_offset <= 0)
704 		return got_error(GOT_ERR_BAD_PACKFILE);
705 
706 	return NULL;
707 }
708 
709 static const struct got_error *
710 resolve_delta_chain(struct got_delta_chain *, struct got_repository *,
711     struct got_packidx *, int, size_t, const char *, off_t, size_t, int,
712     size_t, unsigned int);
713 
714 static const struct got_error *
715 add_delta(struct got_delta_chain *deltas, const char *path_packfile,
716     off_t delta_offset, size_t tslen, int delta_type, size_t delta_size,
717     size_t delta_data_offset, uint8_t *delta_buf, size_t delta_len)
718 {
719 	struct got_delta *delta;
720 
721 	delta = got_delta_open(path_packfile, delta_offset, tslen,
722 	    delta_type, delta_size, delta_data_offset, delta_buf,
723 	    delta_len);
724 	if (delta == NULL)
725 		return got_error_from_errno();
726 	/* delta is freed in got_object_close() */
727 	deltas->nentries++;
728 	SIMPLEQ_INSERT_HEAD(&deltas->entries, delta, entry);
729 	return NULL;
730 }
731 
732 static const struct got_error *
733 resolve_offset_delta(struct got_delta_chain *deltas,
734     struct got_repository *repo, struct got_packidx *packidx, int fd,
735     size_t packfile_size, const char *path_packfile, off_t delta_offset,
736     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
737 
738 {
739 	const struct got_error *err;
740 	off_t base_offset;
741 	uint8_t base_type;
742 	uint64_t base_size;
743 	size_t base_tslen;
744 	off_t delta_data_offset;
745 	uint8_t *delta_buf;
746 	size_t delta_len;
747 
748 	err = parse_offset_delta(&base_offset, fd, delta_offset);
749 	if (err)
750 		return err;
751 
752 	delta_data_offset = lseek(fd, 0, SEEK_CUR);
753 	if (delta_data_offset == -1)
754 		return got_error_from_errno();
755 
756 	err = got_inflate_to_mem_fd(&delta_buf, &delta_len, fd);
757 	if (err)
758 		return err;
759 
760 	err = add_delta(deltas, path_packfile, delta_offset, tslen,
761 	    delta_type, delta_size, delta_data_offset, delta_buf, delta_len);
762 	if (err)
763 		return err;
764 
765 	/* An offset delta must be in the same packfile. */
766 	if (base_offset >= packfile_size)
767 		return got_error(GOT_ERR_PACK_OFFSET);
768 	if (lseek(fd, base_offset, SEEK_SET) == -1)
769 		return got_error_from_errno();
770 
771 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
772 	    fd);
773 	if (err)
774 		return err;
775 
776 	return resolve_delta_chain(deltas, repo, packidx, fd, packfile_size,
777 	    path_packfile, base_offset, base_tslen, base_type, base_size,
778 	    recursion - 1);
779 }
780 
781 static const struct got_error *
782 resolve_ref_delta(struct got_delta_chain *deltas, struct got_repository *repo,
783     struct got_packidx *packidx, int fd, const char *path_packfile,
784     off_t delta_offset, size_t tslen, int delta_type, size_t delta_size,
785     unsigned int recursion)
786 {
787 	const struct got_error *err;
788 	struct got_object_id id;
789 	int idx;
790 	off_t base_offset;
791 	uint8_t base_type;
792 	uint64_t base_size;
793 	size_t base_tslen;
794 	ssize_t n;
795 	char *path_base_packfile;
796 	struct got_pack *base_pack;
797 	off_t delta_data_offset;
798 	uint8_t *delta_buf;
799 	size_t delta_len;
800 
801 	n = read(fd, &id, sizeof(id));
802 	if (n < 0)
803 		return got_error_from_errno();
804 	if (n != sizeof(id))
805 		return got_error(GOT_ERR_BAD_PACKFILE);
806 
807 	delta_data_offset = lseek(fd, 0, SEEK_CUR);
808 	if (delta_data_offset == -1)
809 		return got_error_from_errno();
810 
811 	err = got_inflate_to_mem_fd(&delta_buf, &delta_len, fd);
812 	if (err)
813 		return err;
814 
815 	err = add_delta(deltas, path_packfile, delta_offset, tslen,
816 	    delta_type, delta_size, delta_data_offset, delta_buf, delta_len);
817 	if (err)
818 		return err;
819 
820 	/* Delta base must be in the same pack file. */
821 	idx = get_object_idx(packidx, &id, repo);
822 	if (idx == -1)
823 		return got_error(GOT_ERR_BAD_PACKFILE);
824 
825 	base_offset = get_object_offset(packidx, idx);
826 	if (base_offset == (uint64_t)-1) {
827 		return got_error(GOT_ERR_BAD_PACKIDX);
828 	}
829 
830 	err = get_packfile_path(&path_base_packfile, repo, packidx);
831 	if (err)
832 		return err;
833 
834 	base_pack = get_cached_pack(path_base_packfile, repo);
835 	if (base_pack == NULL) {
836 		err = cache_pack(&base_pack, path_base_packfile, NULL, repo);
837 		if (err)
838 			goto done;
839 	}
840 
841 	if (base_offset >= base_pack->filesize) {
842 		err = got_error(GOT_ERR_PACK_OFFSET);
843 		goto done;
844 	}
845 	if (lseek(base_pack->fd, base_offset, SEEK_SET) == -1) {
846 		err = got_error_from_errno();
847 		goto done;
848 	}
849 
850 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
851 	    base_pack->fd);
852 	if (err)
853 		goto done;
854 
855 	err = resolve_delta_chain(deltas, repo, packidx, base_pack->fd,
856 	    base_pack->filesize, path_base_packfile, base_offset,
857 	    base_tslen, base_type, base_size, recursion - 1);
858 done:
859 	free(path_base_packfile);
860 	return err;
861 }
862 
863 static const struct got_error *
864 resolve_delta_chain(struct got_delta_chain *deltas, struct got_repository *repo,
865     struct got_packidx *packidx, int fd, size_t packfile_size,
866     const char *path_packfile, off_t delta_offset, size_t tslen,
867     int delta_type, size_t delta_size, unsigned int recursion)
868 {
869 	const struct got_error *err = NULL;
870 
871 	if (--recursion == 0)
872 		return got_error(GOT_ERR_RECURSION);
873 
874 	switch (delta_type) {
875 	case GOT_OBJ_TYPE_COMMIT:
876 	case GOT_OBJ_TYPE_TREE:
877 	case GOT_OBJ_TYPE_BLOB:
878 	case GOT_OBJ_TYPE_TAG:
879 		/* Plain types are the final delta base. Recursion ends. */
880 		err = add_delta(deltas, path_packfile, delta_offset, tslen,
881 		    delta_type, delta_size, 0, NULL, 0);
882 		break;
883 	case GOT_OBJ_TYPE_OFFSET_DELTA:
884 		err = resolve_offset_delta(deltas, repo, packidx, fd,
885 		    packfile_size, path_packfile, delta_offset, tslen,
886 		    delta_type, delta_size, recursion - 1);
887 		break;
888 	case GOT_OBJ_TYPE_REF_DELTA:
889 		err = resolve_ref_delta(deltas, repo, packidx, fd,
890 		    path_packfile, delta_offset, tslen, delta_type,
891 		    delta_size, recursion - 1);
892 		break;
893 	default:
894 		return got_error(GOT_ERR_OBJ_TYPE);
895 	}
896 
897 	return err;
898 }
899 
900 static const struct got_error *
901 open_delta_object(struct got_object **obj, struct got_repository *repo,
902     struct got_packidx *packidx, const char *path_packfile, int fd,
903     size_t packfile_size, struct got_object_id *id, off_t offset, size_t tslen,
904     int delta_type, size_t delta_size)
905 {
906 	const struct got_error *err = NULL;
907 	int resolved_type;
908 
909 	*obj = calloc(1, sizeof(**obj));
910 	if (*obj == NULL)
911 		return got_error_from_errno();
912 
913 	(*obj)->flags = 0;
914 	(*obj)->hdrlen = 0;
915 	(*obj)->size = 0; /* Not known because deltas aren't applied yet. */
916 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
917 	(*obj)->pack_offset = offset + tslen;
918 
919 	(*obj)->path_packfile = strdup(path_packfile);
920 	if ((*obj)->path_packfile == NULL) {
921 		err = got_error_from_errno();
922 		goto done;
923 	}
924 	(*obj)->flags |= GOT_OBJ_FLAG_PACKED;
925 
926 	SIMPLEQ_INIT(&(*obj)->deltas.entries);
927 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
928 
929 	err = resolve_delta_chain(&(*obj)->deltas, repo, packidx, fd,
930 	    packfile_size, path_packfile, offset, tslen, delta_type, delta_size,
931 	    GOT_DELTA_CHAIN_RECURSION_MAX);
932 	if (err)
933 		goto done;
934 
935 	err = got_delta_chain_get_base_type(&resolved_type, &(*obj)->deltas);
936 	if (err)
937 		goto done;
938 	(*obj)->type = resolved_type;
939 
940 done:
941 	if (err) {
942 		got_object_close(*obj);
943 		*obj = NULL;
944 	}
945 	return err;
946 }
947 
948 static const struct got_error *
949 open_packed_object(struct got_object **obj, struct got_repository *repo,
950     struct got_packidx *packidx, int idx, struct got_object_id *id)
951 {
952 	const struct got_error *err = NULL;
953 	off_t offset;
954 	char *path_packfile;
955 	struct got_pack *pack;
956 	uint8_t type;
957 	uint64_t size;
958 	size_t tslen;
959 
960 	*obj = NULL;
961 
962 	offset = get_object_offset(packidx, idx);
963 	if (offset == (uint64_t)-1)
964 		return got_error(GOT_ERR_BAD_PACKIDX);
965 
966 	err = get_packfile_path(&path_packfile, repo, packidx);
967 	if (err)
968 		return err;
969 
970 	pack = get_cached_pack(path_packfile, repo);
971 	if (pack == NULL) {
972 		err = cache_pack(&pack, path_packfile, packidx, repo);
973 		if (err)
974 			goto done;
975 	}
976 
977 	if (offset >= pack->filesize) {
978 		err = got_error(GOT_ERR_PACK_OFFSET);
979 		goto done;
980 	}
981 	if (lseek(pack->fd, offset, SEEK_SET) == -1) {
982 		err = got_error_from_errno();
983 		goto done;
984 	}
985 
986 	err = parse_object_type_and_size(&type, &size, &tslen, pack->fd);
987 	if (err)
988 		goto done;
989 
990 	switch (type) {
991 	case GOT_OBJ_TYPE_COMMIT:
992 	case GOT_OBJ_TYPE_TREE:
993 	case GOT_OBJ_TYPE_BLOB:
994 	case GOT_OBJ_TYPE_TAG:
995 		err = open_plain_object(obj, path_packfile, id, type,
996 		    offset + tslen, size);
997 		break;
998 
999 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1000 	case GOT_OBJ_TYPE_REF_DELTA:
1001 		err = open_delta_object(obj, repo, packidx, path_packfile,
1002 		    pack->fd, pack->filesize, id, offset, tslen, type, size);
1003 		break;
1004 
1005 	default:
1006 		err = got_error(GOT_ERR_OBJ_TYPE);
1007 		goto done;
1008 	}
1009 done:
1010 	free(path_packfile);
1011 	return err;
1012 }
1013 
1014 const struct got_error *
1015 got_packfile_open_object(struct got_object **obj, struct got_object_id *id,
1016     struct got_repository *repo)
1017 {
1018 	const struct got_error *err = NULL;
1019 	struct got_packidx *packidx = NULL;
1020 	int idx;
1021 
1022 	err = search_packidx(&packidx, &idx, repo, id);
1023 	if (err)
1024 		return err;
1025 
1026 	err = open_packed_object(obj, repo, packidx, idx, id);
1027 	if (err)
1028 		return err;
1029 
1030 	err = cache_pack(NULL, (*obj)->path_packfile, packidx, repo);
1031 	return err;
1032 }
1033 
1034 static const struct got_error *
1035 get_delta_chain_max_size(uint64_t *max_size, struct got_delta_chain *deltas)
1036 {
1037 	struct got_delta *delta;
1038 	uint64_t base_size = 0, result_size = 0;
1039 
1040 	*max_size = 0;
1041 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1042 		/* Plain object types are the delta base. */
1043 		if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1044 		    delta->type != GOT_OBJ_TYPE_TREE &&
1045 		    delta->type != GOT_OBJ_TYPE_BLOB &&
1046 		    delta->type != GOT_OBJ_TYPE_TAG) {
1047 			const struct got_error *err;
1048 			err = got_delta_get_sizes(&base_size, &result_size,
1049 			    delta->delta_buf, delta->delta_len);
1050 			if (err)
1051 				return err;
1052 		} else
1053 			base_size = delta->size;
1054 		if (base_size > *max_size)
1055 			*max_size = base_size;
1056 		if (result_size > *max_size)
1057 			*max_size = result_size;
1058 	}
1059 
1060 	return NULL;
1061 }
1062 
1063 static const struct got_error *
1064 dump_delta_chain_to_file(size_t *result_size, struct got_delta_chain *deltas,
1065     FILE *outfile, struct got_repository *repo)
1066 {
1067 	const struct got_error *err = NULL;
1068 	struct got_delta *delta;
1069 	FILE *base_file = NULL, *accum_file = NULL;
1070 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1071 	size_t accum_size = 0;
1072 	uint64_t max_size;
1073 	int n = 0;
1074 
1075 	*result_size = 0;
1076 
1077 	if (SIMPLEQ_EMPTY(&deltas->entries))
1078 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1079 
1080 	/* We process small enough files entirely in memory for speed. */
1081 	err = get_delta_chain_max_size(&max_size, deltas);
1082 	if (err)
1083 		return err;
1084 	if (max_size < GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
1085 		accum_buf = malloc(max_size);
1086 		if (accum_buf == NULL)
1087 			return got_error_from_errno();
1088 	} else {
1089 		base_file = got_opentemp();
1090 		if (base_file == NULL)
1091 			return got_error_from_errno();
1092 
1093 		accum_file = got_opentemp();
1094 		if (accum_file == NULL) {
1095 			err = got_error_from_errno();
1096 			fclose(base_file);
1097 			return err;
1098 		}
1099 	}
1100 
1101 	/* Deltas are ordered in ascending order. */
1102 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1103 		if (n == 0) {
1104 			struct got_pack *pack;
1105 			size_t base_len;
1106 			off_t delta_data_offset;
1107 
1108 			/* Plain object types are the delta base. */
1109 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1110 			    delta->type != GOT_OBJ_TYPE_TREE &&
1111 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1112 			    delta->type != GOT_OBJ_TYPE_TAG) {
1113 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1114 				goto done;
1115 			}
1116 
1117 			pack = get_cached_pack(delta->path_packfile, repo);
1118 			if (pack == NULL) {
1119 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1120 				goto done;
1121 			}
1122 
1123 			delta_data_offset = delta->offset + delta->tslen;
1124 			if (delta_data_offset >= pack->filesize) {
1125 				err = got_error(GOT_ERR_PACK_OFFSET);
1126 				goto done;
1127 			}
1128 			if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1129 			    == -1) {
1130 				err = got_error_from_errno();
1131 				goto done;
1132 			}
1133 			if (base_file)
1134 				err = got_inflate_to_file_fd(&base_len,
1135 				    pack->fd, base_file);
1136 			else {
1137 				err = got_inflate_to_mem_fd(&base_buf,
1138 				    &base_len, pack->fd);
1139 				if (base_len < max_size) {
1140 					uint8_t *p;
1141 					p = reallocarray(base_buf, 1, max_size);
1142 					if (p == NULL) {
1143 						err = got_error_from_errno();
1144 						goto done;
1145 					}
1146 					base_buf = p;
1147 				}
1148 			}
1149 			if (err)
1150 				goto done;
1151 			n++;
1152 			if (base_file)
1153 				rewind(base_file);
1154 			continue;
1155 		}
1156 
1157 		if (base_buf) {
1158 			err = got_delta_apply_in_mem(base_buf, delta->delta_buf,
1159 			    delta->delta_len, accum_buf, &accum_size);
1160 			n++;
1161 		} else {
1162 			err = got_delta_apply(base_file, delta->delta_buf,
1163 			    delta->delta_len,
1164 			    /* Final delta application writes to output file. */
1165 			    ++n < deltas->nentries ? accum_file : outfile,
1166 			    &accum_size);
1167 		}
1168 		if (err)
1169 			goto done;
1170 
1171 		if (n < deltas->nentries) {
1172 			/* Accumulated delta becomes the new base. */
1173 			if (base_buf) {
1174 				uint8_t *tmp = accum_buf;
1175 				accum_buf = base_buf;
1176 				base_buf = tmp;
1177 			} else {
1178 				FILE *tmp = accum_file;
1179 				accum_file = base_file;
1180 				base_file = tmp;
1181 				rewind(base_file);
1182 				rewind(accum_file);
1183 			}
1184 		}
1185 	}
1186 
1187 done:
1188 	free(base_buf);
1189 	if (accum_buf) {
1190 		size_t len = fwrite(accum_buf, 1, accum_size, outfile);
1191 		free(accum_buf);
1192 		if (len != accum_size)
1193 			return got_ferror(outfile, GOT_ERR_IO);
1194 	}
1195 	if (base_file)
1196 		fclose(base_file);
1197 	if (accum_file)
1198 		fclose(accum_file);
1199 	rewind(outfile);
1200 	if (err == NULL)
1201 		*result_size = accum_size;
1202 	return err;
1203 }
1204 
1205 static const struct got_error *
1206 dump_delta_chain_to_mem(uint8_t **outbuf, size_t *outlen,
1207     struct got_delta_chain *deltas, struct got_repository *repo)
1208 {
1209 	const struct got_error *err = NULL;
1210 	struct got_delta *delta;
1211 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1212 	size_t accum_size;
1213 	uint64_t max_size;
1214 	int n = 0;
1215 
1216 	*outbuf = NULL;
1217 	*outlen = 0;
1218 
1219 	if (SIMPLEQ_EMPTY(&deltas->entries))
1220 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1221 
1222 	err = get_delta_chain_max_size(&max_size, deltas);
1223 	if (err)
1224 		return err;
1225 	accum_buf = malloc(max_size);
1226 	if (accum_buf == NULL)
1227 		return got_error_from_errno();
1228 
1229 	/* Deltas are ordered in ascending order. */
1230 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1231 		if (n == 0) {
1232 			struct got_pack *pack;
1233 			size_t base_len;
1234 			size_t delta_data_offset;
1235 
1236 			/* Plain object types are the delta base. */
1237 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1238 			    delta->type != GOT_OBJ_TYPE_TREE &&
1239 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1240 			    delta->type != GOT_OBJ_TYPE_TAG) {
1241 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1242 				goto done;
1243 			}
1244 
1245 			pack = get_cached_pack(delta->path_packfile, repo);
1246 			if (pack == NULL) {
1247 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1248 				goto done;
1249 			}
1250 
1251 			delta_data_offset = delta->offset + delta->tslen;
1252 			if (delta_data_offset >= pack->filesize) {
1253 				err = got_error(GOT_ERR_PACK_OFFSET);
1254 				goto done;
1255 			}
1256 			if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1257 			    == -1) {
1258 				err = got_error_from_errno();
1259 				goto done;
1260 			}
1261 			err = got_inflate_to_mem_fd(&base_buf, &base_len,
1262 			    pack->fd);
1263 			if (base_len < max_size) {
1264 				uint8_t *p;
1265 				p = reallocarray(base_buf, 1, max_size);
1266 				if (p == NULL) {
1267 					err = got_error_from_errno();
1268 					goto done;
1269 				}
1270 				base_buf = p;
1271 			}
1272 			if (err)
1273 				goto done;
1274 			n++;
1275 			continue;
1276 		}
1277 
1278 		err = got_delta_apply_in_mem(base_buf, delta->delta_buf,
1279 		    delta->delta_len, accum_buf, &accum_size);
1280 		n++;
1281 		if (err)
1282 			goto done;
1283 
1284 		if (n < deltas->nentries) {
1285 			/* Accumulated delta becomes the new base. */
1286 			uint8_t *tmp = accum_buf;
1287 			accum_buf = base_buf;
1288 			base_buf = tmp;
1289 		}
1290 	}
1291 
1292 done:
1293 	free(base_buf);
1294 	if (err) {
1295 		free(accum_buf);
1296 		*outbuf = NULL;
1297 		*outlen = 0;
1298 	} else {
1299 		*outbuf = accum_buf;
1300 		*outlen = accum_size;
1301 	}
1302 	return err;
1303 }
1304 
1305 const struct got_error *
1306 got_packfile_extract_object(FILE **f, struct got_object *obj,
1307     struct got_repository *repo)
1308 {
1309 	const struct got_error *err = NULL;
1310 
1311 	*f = NULL;
1312 
1313 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1314 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1315 
1316 	*f = got_opentemp();
1317 	if (*f == NULL) {
1318 		err = got_error_from_errno();
1319 		goto done;
1320 	}
1321 
1322 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1323 		struct got_pack *pack;
1324 
1325 		pack = get_cached_pack(obj->path_packfile, repo);
1326 		if (pack == NULL) {
1327 			err = cache_pack(&pack, obj->path_packfile, NULL, repo);
1328 			if (err)
1329 				goto done;
1330 		}
1331 
1332 		if (obj->pack_offset >= pack->filesize) {
1333 			err = got_error(GOT_ERR_PACK_OFFSET);
1334 			goto done;
1335 		}
1336 		if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1) {
1337 			err = got_error_from_errno();
1338 			goto done;
1339 		}
1340 
1341 		err = got_inflate_to_file_fd(&obj->size, pack->fd, *f);
1342 	} else
1343 		err = dump_delta_chain_to_file(&obj->size,
1344 		    &obj->deltas, *f, repo);
1345 done:
1346 	if (err && *f) {
1347 		fclose(*f);
1348 		*f = NULL;
1349 	}
1350 	return err;
1351 }
1352 
1353 const struct got_error *
1354 got_packfile_extract_object_to_mem(uint8_t **buf, size_t *len,
1355     struct got_object *obj, struct got_repository *repo)
1356 {
1357 	const struct got_error *err = NULL;
1358 
1359 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1360 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1361 
1362 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1363 		struct got_pack *pack;
1364 
1365 		pack = get_cached_pack(obj->path_packfile, repo);
1366 		if (pack == NULL) {
1367 			err = cache_pack(&pack, obj->path_packfile, NULL, repo);
1368 			if (err)
1369 				goto done;
1370 		}
1371 
1372 		if (obj->pack_offset >= pack->filesize) {
1373 			err = got_error(GOT_ERR_PACK_OFFSET);
1374 			goto done;
1375 		}
1376 		if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1) {
1377 			err = got_error_from_errno();
1378 			goto done;
1379 		}
1380 
1381 		err = got_inflate_to_mem_fd(buf, len, pack->fd);
1382 	} else
1383 		err = dump_delta_chain_to_mem(buf, len, &obj->deltas, repo);
1384 done:
1385 	return err;
1386 }