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Date:: Sat Mar 17 14:17:14 2018 UTC
Message:: initialize some output variables on failure
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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 
38 #include "got_sha1_lib.h"
39 #include "got_pack_lib.h"
40 #include "got_path_lib.h"
41 #include "got_delta_lib.h"
42 #include "got_zbuf_lib.h"
43 #include "got_object_lib.h"
44 #include "got_repository_lib.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_idx)
79 {
80 	struct stat sb;
81 	char *path_pack;
82 	char base_path[PATH_MAX];
83 	char *dot;
84 
85 	if (strlcpy(base_path, path_idx, PATH_MAX) > PATH_MAX)
86 		return got_error(GOT_ERR_NO_SPACE);
87 
88 	dot = strrchr(base_path, '.');
89 	if (dot == NULL)
90 		return got_error(GOT_ERR_BAD_PATH);
91 	*dot = '\0';
92 	if (asprintf(&path_pack, "%s.pack", base_path) == -1)
93 		return got_error(GOT_ERR_NO_MEM);
94 
95 	if (stat(path_pack, &sb) != 0) {
96 		free(path_pack);
97 		return got_error_from_errno();
98 	}
99 
100 	free(path_pack);
101 	*size = sb.st_size;
102 	return 0;
103 }
104 
105 const struct got_error *
106 got_packidx_open(struct got_packidx_v2_hdr **packidx, const char *path)
107 {
108 	struct got_packidx_v2_hdr *p;
109 	FILE *f;
110 	const struct got_error *err = NULL;
111 	size_t n, nobj, packfile_size;
112 	SHA1_CTX ctx;
113 	uint8_t sha1[SHA1_DIGEST_LENGTH];
114 
115 	SHA1Init(&ctx);
116 
117 	f = fopen(path, "rb");
118 	if (f == NULL)
119 		return got_error_from_errno();
120 
121 	err = get_packfile_size(&packfile_size, path);
122 	if (err)
123 		return err;
124 
125 	p = calloc(1, sizeof(*p));
126 	if (p == NULL) {
127 		err = got_error(GOT_ERR_NO_MEM);
128 		goto done;
129 	}
130 
131 	n = fread(&p->magic, sizeof(p->magic), 1, f);
132 	if (n != 1) {
133 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
134 		goto done;
135 	}
136 
137 	if (betoh32(p->magic) != GOT_PACKIDX_V2_MAGIC) {
138 		err = got_error(GOT_ERR_BAD_PACKIDX);
139 		goto done;
140 	}
141 
142 	SHA1Update(&ctx, (uint8_t *)&p->magic, sizeof(p->magic));
143 
144 	n = fread(&p->version, sizeof(p->version), 1, f);
145 	if (n != 1) {
146 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
147 		goto done;
148 	}
149 
150 	if (betoh32(p->version) != GOT_PACKIDX_VERSION) {
151 		err = got_error(GOT_ERR_BAD_PACKIDX);
152 		goto done;
153 	}
154 
155 	SHA1Update(&ctx, (uint8_t *)&p->version, sizeof(p->version));
156 
157 	n = fread(&p->fanout_table, sizeof(p->fanout_table), 1, f);
158 	if (n != 1) {
159 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
160 		goto done;
161 	}
162 
163 	err = verify_fanout_table(p->fanout_table);
164 	if (err)
165 		goto done;
166 
167 	SHA1Update(&ctx, (uint8_t *)p->fanout_table, sizeof(p->fanout_table));
168 
169 	nobj = betoh32(p->fanout_table[0xff]);
170 
171 	p->sorted_ids = calloc(nobj, sizeof(*p->sorted_ids));
172 	if (p->sorted_ids == NULL) {
173 		err = got_error(GOT_ERR_NO_MEM);
174 		goto done;
175 	}
176 
177 	n = fread(p->sorted_ids, sizeof(*p->sorted_ids), nobj, f);
178 	if (n != nobj) {
179 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
180 		goto done;
181 	}
182 
183 	SHA1Update(&ctx, (uint8_t *)p->sorted_ids,
184 	    nobj * sizeof(*p->sorted_ids));
185 
186 	p->crc32 = calloc(nobj, sizeof(*p->crc32));
187 	if (p->crc32 == NULL) {
188 		err = got_error(GOT_ERR_NO_MEM);
189 		goto done;
190 	}
191 
192 	n = fread(p->crc32, sizeof(*p->crc32), 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->crc32, nobj * sizeof(*p->crc32));
199 
200 	p->offsets = calloc(nobj, sizeof(*p->offsets));
201 	if (p->offsets == NULL) {
202 		err = got_error(GOT_ERR_NO_MEM);
203 		goto done;
204 	}
205 
206 	n = fread(p->offsets, sizeof(*p->offsets), nobj, f);
207 	if (n != nobj) {
208 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
209 		goto done;
210 	}
211 
212 	SHA1Update(&ctx, (uint8_t *)p->offsets, nobj * sizeof(*p->offsets));
213 
214 	/* Large file offsets are contained only in files > 2GB. */
215 	if (packfile_size <= 0x80000000)
216 		goto checksum;
217 
218 	p->large_offsets = calloc(nobj, sizeof(*p->large_offsets));
219 	if (p->large_offsets == NULL) {
220 		err = got_error(GOT_ERR_NO_MEM);
221 		goto done;
222 	}
223 
224 	n = fread(p->large_offsets, sizeof(*p->large_offsets), nobj, f);
225 	if (n != nobj) {
226 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
227 		goto done;
228 	}
229 
230 	SHA1Update(&ctx, (uint8_t*)p->large_offsets,
231 	    nobj * sizeof(*p->large_offsets));
232 
233 checksum:
234 	n = fread(&p->trailer, sizeof(p->trailer), 1, f);
235 	if (n != 1) {
236 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
237 		goto done;
238 	}
239 
240 	SHA1Update(&ctx, p->trailer.packfile_sha1, SHA1_DIGEST_LENGTH);
241 	SHA1Final(sha1, &ctx);
242 	if (memcmp(p->trailer.packidx_sha1, sha1, SHA1_DIGEST_LENGTH) != 0)
243 		err = got_error(GOT_ERR_PACKIDX_CSUM);
244 done:
245 	fclose(f);
246 	if (err)
247 		got_packidx_close(p);
248 	else
249 		*packidx = p;
250 	return err;
251 }
252 
253 void
254 got_packidx_close(struct got_packidx_v2_hdr *packidx)
255 {
256 	free(packidx->sorted_ids);
257 	free(packidx->offsets);
258 	free(packidx->crc32);
259 	free(packidx->large_offsets);
260 	free(packidx);
261 }
262 
263 static int
264 is_packidx_filename(const char *name, size_t len)
265 {
266 	if (len != GOT_PACKIDX_NAMELEN)
267 		return 0;
268 
269 	if (strncmp(name, GOT_PACK_PREFIX, strlen(GOT_PACK_PREFIX)) != 0)
270 		return 0;
271 
272 	if (strcmp(name + strlen(GOT_PACK_PREFIX) +
273 	    SHA1_DIGEST_STRING_LENGTH - 1, GOT_PACKIDX_SUFFIX) != 0)
274 		return 0;
275 
276 	return 1;
277 }
278 
279 static off_t
280 get_object_offset(struct got_packidx_v2_hdr *packidx, int idx)
281 {
282 	uint32_t totobj = betoh32(packidx->fanout_table[0xff]);
283 	uint32_t offset = betoh32(packidx->offsets[idx]);
284 	if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
285 		uint64_t loffset;
286 		idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
287 		if (idx < 0 || idx > totobj || packidx->large_offsets == NULL)
288 			return -1;
289 		loffset = betoh64(packidx->large_offsets[idx]);
290 		return (loffset > INT64_MAX ? -1 : (off_t)loffset);
291 	}
292 	return (off_t)(offset & GOT_PACKIDX_OFFSET_VAL_MASK);
293 }
294 
295 static int
296 get_object_idx(struct got_packidx_v2_hdr *packidx, struct got_object_id *id)
297 {
298 	u_int8_t id0 = id->sha1[0];
299 	uint32_t totobj = betoh32(packidx->fanout_table[0xff]);
300 	int i = 0;
301 
302 	if (id0 > 0)
303 		i = betoh32(packidx->fanout_table[id0 - 1]);
304 
305 	while (i < totobj) {
306 		struct got_object_id *oid = &packidx->sorted_ids[i];
307 		int cmp = got_object_id_cmp(id, oid);
308 
309 		if (cmp == 0)
310 			return i;
311 		i++;
312 	}
313 
314 	return -1;
315 }
316 
317 static struct got_packidx_v2_hdr *
318 dup_packidx(struct got_packidx_v2_hdr *packidx)
319 {
320 	struct got_packidx_v2_hdr *p;
321 	size_t nobj;
322 
323 	p = calloc(1, sizeof(*p));
324 	if (p == NULL)
325 		return NULL;
326 
327 	memcpy(p, packidx, sizeof(*p));
328 	p->sorted_ids = NULL;
329 	p->crc32 = NULL;
330 	p->offsets = NULL;
331 	p->large_offsets = NULL;
332 
333 	nobj = betoh32(p->fanout_table[0xff]);
334 
335 	p->sorted_ids = calloc(nobj, sizeof(*p->sorted_ids));
336 	if (p->sorted_ids == NULL)
337 		goto err;
338 	memcpy(p->sorted_ids, packidx->sorted_ids, nobj * sizeof(*p->sorted_ids));
339 
340 	p->crc32 = calloc(nobj, sizeof(*p->crc32));
341 	if (p->crc32 == NULL)
342 		goto err;
343 	memcpy(p->crc32, packidx->crc32, nobj * sizeof(*p->crc32));
344 
345 	p->offsets = calloc(nobj, sizeof(*p->offsets));
346 	if (p->offsets == NULL)
347 		goto err;
348 	memcpy(p->offsets, packidx->offsets, nobj * sizeof(*p->offsets));
349 
350 	if (p->large_offsets) {
351 		p->large_offsets = calloc(nobj, sizeof(*p->large_offsets));
352 		if (p->large_offsets == NULL)
353 			goto err;
354 		memcpy(p->large_offsets, packidx->large_offsets,
355 		    nobj * sizeof(*p->large_offsets));
356 	}
357 
358 	return p;
359 
360 err:
361 	free(p->large_offsets);
362 	free(p->offsets);
363 	free(p->crc32);
364 	free(p->sorted_ids);
365 	free(p);
366 	return NULL;
367 }
368 
369 static void
370 cache_packidx(struct got_packidx_v2_hdr *packidx, struct got_repository *repo)
371 {
372 	int i;
373 
374 	for (i = 0; i < nitems(repo->packidx_cache); i++) {
375 		if (repo->packidx_cache[i] == NULL)
376 			break;
377 	}
378 
379 	if (i == nitems(repo->packidx_cache)) {
380 		got_packidx_close(repo->packidx_cache[i - 1]);
381 		memmove(&repo->packidx_cache[1], &repo->packidx_cache[0],
382 		    sizeof(repo->packidx_cache) -
383 		    sizeof(repo->packidx_cache[0]));
384 		i = 0;
385 	}
386 
387 	repo->packidx_cache[i] = dup_packidx(packidx);
388 }
389 
390 static const struct got_error *
391 search_packidx(struct got_packidx_v2_hdr **packidx, int *idx,
392     struct got_repository *repo, struct got_object_id *id)
393 {
394 	const struct got_error *err;
395 	char *path_packdir;
396 	DIR *packdir;
397 	struct dirent *dent;
398 	char *path_packidx;
399 	int i;
400 
401 	/* Search pack index cache. */
402 	for (i = 0; i < nitems(repo->packidx_cache); i++) {
403 		if (repo->packidx_cache[i] == NULL)
404 			break;
405 		*idx = get_object_idx(repo->packidx_cache[i], id);
406 		if (*idx != -1) {
407 			*packidx = repo->packidx_cache[i];
408 			if (*packidx == NULL)
409 				return got_error(GOT_ERR_NO_MEM);
410 			return NULL;
411 		}
412 	}
413 	/* No luck. Search the filesystem. */
414 
415 	path_packdir = got_repo_get_path_objects_pack(repo);
416 	if (path_packdir == NULL)
417 		return got_error(GOT_ERR_NO_MEM);
418 
419 	packdir = opendir(path_packdir);
420 	if (packdir == NULL) {
421 		err = got_error_from_errno();
422 		goto done;
423 	}
424 
425 	while ((dent = readdir(packdir)) != NULL) {
426 		if (!is_packidx_filename(dent->d_name, dent->d_namlen))
427 			continue;
428 
429 		if (asprintf(&path_packidx, "%s/%s", path_packdir,
430 		    dent->d_name) == -1) {
431 			err = got_error(GOT_ERR_NO_MEM);
432 			goto done;
433 		}
434 
435 		err = got_packidx_open(packidx, path_packidx);
436 		free(path_packidx);
437 		if (err)
438 			goto done;
439 
440 		*idx = get_object_idx(*packidx, id);
441 		if (*idx != -1) {
442 			err = NULL; /* found the object */
443 			cache_packidx(*packidx, repo);
444 			goto done;
445 		}
446 
447 		got_packidx_close(*packidx);
448 		*packidx = NULL;
449 	}
450 
451 	err = got_error(GOT_ERR_NO_OBJ);
452 done:
453 	free(path_packdir);
454 	if (packdir && closedir(packdir) != 0 && err == 0)
455 		err = got_error_from_errno();
456 	return err;
457 }
458 
459 static const struct got_error *
460 get_packfile_path(char **path_packfile, struct got_repository *repo,
461     struct got_packidx_v2_hdr *packidx)
462 {
463 	char *path_packdir;
464 	char hex[SHA1_DIGEST_STRING_LENGTH];
465 	char *sha1str;
466 
467 	path_packdir = got_repo_get_path_objects_pack(repo);
468 	if (path_packdir == NULL)
469 		return got_error(GOT_ERR_NO_MEM);
470 
471 	sha1str = got_sha1_digest_to_str(packidx->trailer.packfile_sha1,
472 	    hex, sizeof(hex));
473 	if (sha1str == NULL)
474 		return got_error(GOT_ERR_PACKIDX_CSUM);
475 
476 	if (asprintf(path_packfile, "%s/%s%s%s", path_packdir,
477 	    GOT_PACK_PREFIX, sha1str, GOT_PACKFILE_SUFFIX) == -1) {
478 		*path_packfile = NULL;
479 		return got_error(GOT_ERR_NO_MEM);
480 	}
481 
482 	return NULL;
483 }
484 
485 const struct got_error *
486 read_packfile_hdr(FILE *f, struct got_packidx_v2_hdr *packidx)
487 {
488 	const struct got_error *err = NULL;
489 	uint32_t totobj = betoh32(packidx->fanout_table[0xff]);
490 	struct got_packfile_hdr hdr;
491 	size_t n;
492 
493 	n = fread(&hdr, sizeof(hdr), 1, f);
494 	if (n != 1)
495 		return got_ferror(f, GOT_ERR_BAD_PACKIDX);
496 
497 	if (betoh32(hdr.signature) != GOT_PACKFILE_SIGNATURE ||
498 	    betoh32(hdr.version) != GOT_PACKFILE_VERSION ||
499 	    betoh32(hdr.nobjects) != totobj)
500 		err = got_error(GOT_ERR_BAD_PACKFILE);
501 
502 	return err;
503 }
504 
505 #ifdef notyet
506 static const struct got_error *
507 map_packfile_segment(struct got_pack_mapping **map, const char *path_packfile,
508     off_t offset, size_t len)
509 {
510 	const struct got_error *err = NULL;
511 
512 	if (len < GOT_PACK_MAPPING_MIN_SIZE)
513 		len = GOT_PACK_MAPPING_MIN_SIZE;
514 
515 	if (len > GOT_PACK_MAPPING_MAX_SIZE)
516 		return got_error(GOT_ERR_NO_SPACE);
517 
518 	*map = calloc(1, sizeof(**map));
519 	if (*map == NULL)
520 		return got_error(GOT_ERR_NO_MEM);
521 
522 	(*map)->fd = open(path_packfile, O_RDONLY | O_NOFOLLOW);
523 	if ((*map)->fd == -1) {
524 		err = got_error_from_errno();
525 		free((*map));
526 		*map = NULL;
527 		return err;
528 	}
529 
530 	(*map)->addr = mmap(NULL, len, PROT_READ, MAP_PRIVATE, (*map)->fd, offset);
531 	if ((*map)->addr == NULL) {
532 		err = got_error_from_errno();
533 		close((*map)->fd);
534 		free((*map));
535 		*map = NULL;
536 		return err;
537 	}
538 
539 	(*map)->offset = offset;
540 	(*map)->len = len;
541 
542 	return NULL;
543 }
544 #endif
545 
546 static const struct got_error *
547 unmap_packfile_segment(struct got_pack_mapping *map)
548 {
549 	if (munmap(map->addr, map->len) == -1 || close(map->fd) == -1)
550 		return got_error_from_errno();
551 	free(map);
552 	return NULL;
553 }
554 
555 static const struct got_error *
556 open_packfile(FILE **packfile, const char *path_packfile,
557     struct got_repository *repo, struct got_packidx_v2_hdr *packidx)
558 {
559 	const struct got_error *err = NULL;
560 
561 	*packfile = NULL;
562 
563 	*packfile = fopen(path_packfile, "rb");
564 	if (*packfile == NULL) {
565 		err = got_error_from_errno();
566 		return err;
567 	}
568 
569 	if (packidx) {
570 		err = read_packfile_hdr(*packfile, packidx);
571 		if (err) {
572 			fclose(*packfile);
573 			*packfile = NULL;
574 		}
575 	}
576 	return err;
577 }
578 
579 const struct got_error *
580 got_pack_close(struct got_pack *pack)
581 {
582 	const struct got_error *err = NULL;
583 
584 	while (!TAILQ_EMPTY(&pack->mappings)) {
585 		struct got_pack_mapping *map = TAILQ_FIRST(&pack->mappings);
586 		err = unmap_packfile_segment(map);
587 		if (err)
588 			break;
589 		TAILQ_REMOVE(&pack->mappings, map, entry);
590 		pack->nmappings--;
591 	}
592 
593 	if (err == NULL) {
594 		fclose(pack->packfile);
595 		pack->packfile = NULL;
596 		free(pack->path_packfile);
597 		pack->path_packfile = NULL;
598 		pack->filesize = 0;
599 	}
600 
601 	return err;
602 }
603 
604 static const struct got_error *
605 cache_pack(struct got_pack **packp, const char *path_packfile,
606     struct got_packidx_v2_hdr *packidx, struct got_repository *repo)
607 {
608 	const struct got_error *err = NULL;
609 	struct got_pack *pack = NULL;
610 	int i;
611 
612 	if (packp)
613 		*packp = NULL;
614 
615 	for (i = 0; i < nitems(repo->packs); i++) {
616 		pack = &repo->packs[i];
617 		if (pack->path_packfile == NULL)
618 			break;
619 		if (strcmp(pack->path_packfile, path_packfile) == 0)
620 			return NULL;
621 	}
622 
623 	if (i == nitems(repo->packs) - 1) {
624 		got_pack_close(&repo->packs[i - 1]);
625 		memmove(&repo->packs[1], &repo->packs[0],
626 		    sizeof(repo->packs) - sizeof(repo->packs[0]));
627 		i = 0;
628 	}
629 
630 	pack = &repo->packs[i];
631 
632 	TAILQ_INIT(&pack->mappings);
633 
634 	pack->path_packfile = strdup(path_packfile);
635 	if (pack->path_packfile == NULL) {
636 		err = got_error(GOT_ERR_NO_MEM);
637 		goto done;
638 	}
639 
640 	err = open_packfile(&pack->packfile, path_packfile, repo, packidx);
641 	if (err)
642 		goto done;
643 
644 	err = get_packfile_size(&pack->filesize, path_packfile);
645 done:
646 	if (err) {
647 		if (pack)
648 			free(pack->path_packfile);
649 		free(pack);
650 	} else if (packp)
651 		*packp = pack;
652 	return err;
653 }
654 
655 struct got_pack *
656 get_cached_pack(const char *path_packfile, struct got_repository *repo)
657 {
658 	struct got_pack *pack = NULL;
659 	int i;
660 
661 	for (i = 0; i < nitems(repo->packs); i++) {
662 		pack = &repo->packs[i];
663 		if (pack->path_packfile == NULL)
664 			break;
665 		if (strcmp(pack->path_packfile, path_packfile) == 0)
666 			return pack;
667 	}
668 
669 	return NULL;
670 }
671 
672 static const struct got_error *
673 parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len,
674     FILE *packfile)
675 {
676 	uint8_t t = 0;
677 	uint64_t s = 0;
678 	uint8_t sizeN;
679 	size_t n;
680 	int i = 0;
681 
682 	do {
683 		/* We do not support size values which don't fit in 64 bit. */
684 		if (i > 9)
685 			return got_error(GOT_ERR_NO_SPACE);
686 
687 		n = fread(&sizeN, sizeof(sizeN), 1, packfile);
688 		if (n != 1)
689 			return got_ferror(packfile, GOT_ERR_BAD_PACKIDX);
690 
691 		if (i == 0) {
692 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
693 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
694 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
695 		} else {
696 			size_t shift = 4 + 7 * (i - 1);
697 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
698 		}
699 		i++;
700 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
701 
702 	*type = t;
703 	*size = s;
704 	*len = i * sizeof(sizeN);
705 	return NULL;
706 }
707 
708 static const struct got_error *
709 open_plain_object(struct got_object **obj, const char *path_packfile,
710     struct got_object_id *id, uint8_t type, off_t offset, size_t size)
711 {
712 	*obj = calloc(1, sizeof(**obj));
713 	if (*obj == NULL)
714 		return got_error(GOT_ERR_NO_MEM);
715 
716 	(*obj)->path_packfile = strdup(path_packfile);
717 	if ((*obj)->path_packfile == NULL) {
718 		free(*obj);
719 		*obj = NULL;
720 		return got_error(GOT_ERR_NO_MEM);
721 	}
722 
723 	(*obj)->type = type;
724 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
725 	(*obj)->hdrlen = 0;
726 	(*obj)->size = size;
727 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
728 	(*obj)->pack_offset = offset;
729 
730 	return NULL;
731 }
732 
733 static const struct got_error *
734 parse_negative_offset(int64_t *offset, size_t *len, FILE *packfile)
735 {
736 	int64_t o = 0;
737 	uint8_t offN;
738 	size_t n;
739 	int i = 0;
740 
741 	do {
742 		/* We do not support offset values which don't fit in 64 bit. */
743 		if (i > 8)
744 			return got_error(GOT_ERR_NO_SPACE);
745 
746 		n = fread(&offN, sizeof(offN), 1, packfile);
747 		if (n != 1)
748 			return got_ferror(packfile, GOT_ERR_BAD_PACKIDX);
749 
750 		if (i == 0)
751 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
752 		else {
753 			o++;
754 			o <<= 7;
755 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
756 		}
757 		i++;
758 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
759 
760 	*offset = o;
761 	*len = i * sizeof(offN);
762 	return NULL;
763 }
764 
765 static const struct got_error *
766 parse_offset_delta(off_t *base_offset, FILE *packfile, off_t offset)
767 {
768 	const struct got_error *err;
769 	int64_t negoffset;
770 	size_t negofflen;
771 
772 	err = parse_negative_offset(&negoffset, &negofflen, packfile);
773 	if (err)
774 		return err;
775 
776 	/* Compute the base object's offset (must be in the same pack file). */
777 	*base_offset = (offset - negoffset);
778 	if (*base_offset <= 0)
779 		return got_error(GOT_ERR_BAD_PACKFILE);
780 
781 	return NULL;
782 }
783 
784 static const struct got_error *
785 resolve_delta_chain(struct got_delta_chain *, struct got_repository *,
786     FILE *, const char *, off_t, size_t, int, size_t);
787 
788 static const struct got_error *
789 add_delta(struct got_delta_chain *deltas, const char *path_packfile,
790     off_t delta_offset, size_t tslen, int delta_type, size_t delta_size,
791     size_t delta_data_offset, uint8_t *delta_buf, size_t delta_len)
792 {
793 	struct got_delta *delta;
794 
795 	delta = got_delta_open(path_packfile, delta_offset, tslen,
796 	    delta_type, delta_size, delta_data_offset, delta_buf,
797 	    delta_len);
798 	if (delta == NULL)
799 		return got_error(GOT_ERR_NO_MEM);
800 	/* delta is freed in got_object_close() */
801 	deltas->nentries++;
802 	SIMPLEQ_INSERT_HEAD(&deltas->entries, delta, entry);
803 	return NULL;
804 }
805 
806 static const struct got_error *
807 resolve_offset_delta(struct got_delta_chain *deltas,
808     struct got_repository *repo, FILE *packfile, const char *path_packfile,
809     off_t delta_offset,size_t tslen, int delta_type, size_t delta_size)
810 
811 {
812 	const struct got_error *err;
813 	off_t base_offset;
814 	uint8_t base_type;
815 	uint64_t base_size;
816 	size_t base_tslen;
817 	off_t delta_data_offset;
818 	uint8_t *delta_buf;
819 	size_t delta_len;
820 
821 	err = parse_offset_delta(&base_offset, packfile, delta_offset);
822 	if (err)
823 		return err;
824 
825 	delta_data_offset = ftello(packfile);
826 	if (delta_data_offset == -1)
827 		return got_error_from_errno();
828 
829 	err = got_inflate_to_mem(&delta_buf, &delta_len, packfile);
830 	if (err)
831 		return err;
832 
833 	err = add_delta(deltas, path_packfile, delta_offset, tslen,
834 	    delta_type, delta_size, delta_data_offset, delta_buf, delta_len);
835 	if (err)
836 		return err;
837 
838 	/* An offset delta must be in the same packfile. */
839 	if (fseeko(packfile, base_offset, SEEK_SET) != 0)
840 		return got_error_from_errno();
841 
842 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
843 	    packfile);
844 	if (err)
845 		return err;
846 
847 	return resolve_delta_chain(deltas, repo, packfile, path_packfile,
848 	    base_offset, base_tslen, base_type, base_size);
849 }
850 
851 static const struct got_error *
852 resolve_ref_delta(struct got_delta_chain *deltas, struct got_repository *repo,
853     FILE *packfile, const char *path_packfile, off_t delta_offset,
854     size_t tslen, int delta_type, size_t delta_size)
855 {
856 	const struct got_error *err;
857 	struct got_object_id id;
858 	struct got_packidx_v2_hdr *packidx;
859 	int idx;
860 	off_t base_offset;
861 	uint8_t base_type;
862 	uint64_t base_size;
863 	size_t base_tslen;
864 	size_t n;
865 	char *path_base_packfile;
866 	struct got_pack *base_pack;
867 	off_t delta_data_offset;
868 	uint8_t *delta_buf;
869 	size_t delta_len;
870 
871 	n = fread(&id, sizeof(id), 1, packfile);
872 	if (n != 1)
873 		return got_ferror(packfile, GOT_ERR_IO);
874 
875 	delta_data_offset = ftello(packfile);
876 	if (delta_data_offset == -1)
877 		return got_error_from_errno();
878 
879 	err = got_inflate_to_mem(&delta_buf, &delta_len, packfile);
880 	if (err)
881 		return err;
882 
883 	err = add_delta(deltas, path_packfile, delta_offset, tslen,
884 	    delta_type, delta_size, delta_data_offset, delta_buf, delta_len);
885 	if (err)
886 		return err;
887 
888 	err = search_packidx(&packidx, &idx, repo, &id);
889 	if (err)
890 		return err;
891 
892 	base_offset = get_object_offset(packidx, idx);
893 	if (base_offset == (uint64_t)-1) {
894 		return got_error(GOT_ERR_BAD_PACKIDX);
895 	}
896 
897 	err = get_packfile_path(&path_base_packfile, repo, packidx);
898 	if (err)
899 		return err;
900 
901 	base_pack = get_cached_pack(path_base_packfile, repo);
902 	if (base_pack == NULL) {
903 		err = cache_pack(&base_pack, path_base_packfile, NULL, repo);
904 		if (err)
905 			goto done;
906 	}
907 
908 	if (fseeko(base_pack->packfile, base_offset, SEEK_SET) != 0) {
909 		err = got_error_from_errno();
910 		goto done;
911 	}
912 
913 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
914 	    base_pack->packfile);
915 	if (err)
916 		goto done;
917 
918 	err = resolve_delta_chain(deltas, repo, base_pack->packfile,
919 	    path_base_packfile, base_offset, base_tslen, base_type,
920 	    base_size);
921 done:
922 	free(path_base_packfile);
923 	return err;
924 }
925 
926 static const struct got_error *
927 resolve_delta_chain(struct got_delta_chain *deltas, struct got_repository *repo,
928     FILE *packfile, const char *path_packfile, off_t delta_offset, size_t tslen,
929     int delta_type, size_t delta_size)
930 {
931 	const struct got_error *err = NULL;
932 
933 	switch (delta_type) {
934 	case GOT_OBJ_TYPE_COMMIT:
935 	case GOT_OBJ_TYPE_TREE:
936 	case GOT_OBJ_TYPE_BLOB:
937 	case GOT_OBJ_TYPE_TAG:
938 		/* Plain types are the final delta base. Recursion ends. */
939 		err = add_delta(deltas, path_packfile, delta_offset, tslen,
940 		    delta_type, delta_size, 0, NULL, 0);
941 		break;
942 	case GOT_OBJ_TYPE_OFFSET_DELTA:
943 		err = resolve_offset_delta(deltas, repo, packfile,
944 		    path_packfile, delta_offset, tslen, delta_type,
945 		    delta_size);
946 		break;
947 	case GOT_OBJ_TYPE_REF_DELTA:
948 		err = resolve_ref_delta(deltas, repo, packfile,
949 		    path_packfile, delta_offset, tslen, delta_type,
950 		    delta_size);
951 		break;
952 	default:
953 		return got_error(GOT_ERR_NOT_IMPL);
954 	}
955 
956 	return err;
957 }
958 
959 static const struct got_error *
960 open_delta_object(struct got_object **obj, struct got_repository *repo,
961     struct got_packidx_v2_hdr *packidx, const char *path_packfile,
962     FILE *packfile, struct got_object_id *id, off_t offset, size_t tslen,
963     int delta_type, size_t delta_size)
964 {
965 	const struct got_error *err = NULL;
966 	int resolved_type;
967 
968 	*obj = calloc(1, sizeof(**obj));
969 	if (*obj == NULL)
970 		return got_error(GOT_ERR_NO_MEM);
971 
972 	(*obj)->flags = 0;
973 	(*obj)->hdrlen = 0;
974 	(*obj)->size = 0; /* Not known because deltas aren't applied yet. */
975 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
976 	(*obj)->pack_offset = offset + tslen;
977 
978 	(*obj)->path_packfile = strdup(path_packfile);
979 	if ((*obj)->path_packfile == NULL) {
980 		err = got_error(GOT_ERR_NO_MEM);
981 		goto done;
982 	}
983 	(*obj)->flags |= GOT_OBJ_FLAG_PACKED;
984 
985 	SIMPLEQ_INIT(&(*obj)->deltas.entries);
986 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
987 
988 	err = resolve_delta_chain(&(*obj)->deltas, repo, packfile,
989 	    path_packfile, offset, tslen, delta_type, delta_size);
990 	if (err)
991 		goto done;
992 
993 	err = got_delta_chain_get_base_type(&resolved_type, &(*obj)->deltas);
994 	if (err)
995 		goto done;
996 	(*obj)->type = resolved_type;
997 
998 done:
999 	if (err) {
1000 		got_object_close(*obj);
1001 		*obj = NULL;
1002 	}
1003 	return err;
1004 }
1005 
1006 static const struct got_error *
1007 open_packed_object(struct got_object **obj, struct got_repository *repo,
1008     struct got_packidx_v2_hdr *packidx, int idx, struct got_object_id *id)
1009 {
1010 	const struct got_error *err = NULL;
1011 	off_t offset;
1012 	char *path_packfile;
1013 	struct got_pack *pack;
1014 	uint8_t type;
1015 	uint64_t size;
1016 	size_t tslen;
1017 
1018 	*obj = NULL;
1019 
1020 	offset = get_object_offset(packidx, idx);
1021 	if (offset == (uint64_t)-1)
1022 		return got_error(GOT_ERR_BAD_PACKIDX);
1023 
1024 	err = get_packfile_path(&path_packfile, repo, packidx);
1025 	if (err)
1026 		return err;
1027 
1028 	pack = get_cached_pack(path_packfile, repo);
1029 	if (pack == NULL) {
1030 		err = cache_pack(&pack, path_packfile, packidx, repo);
1031 		if (err)
1032 			goto done;
1033 	}
1034 
1035 	if (fseeko(pack->packfile, offset, SEEK_SET) != 0) {
1036 		err = got_error_from_errno();
1037 		goto done;
1038 	}
1039 
1040 	err = parse_object_type_and_size(&type, &size, &tslen, pack->packfile);
1041 	if (err)
1042 		goto done;
1043 
1044 	switch (type) {
1045 	case GOT_OBJ_TYPE_COMMIT:
1046 	case GOT_OBJ_TYPE_TREE:
1047 	case GOT_OBJ_TYPE_BLOB:
1048 	case GOT_OBJ_TYPE_TAG:
1049 		err = open_plain_object(obj, path_packfile, id, type,
1050 		    offset + tslen, size);
1051 		break;
1052 
1053 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1054 	case GOT_OBJ_TYPE_REF_DELTA:
1055 		err = open_delta_object(obj, repo, packidx, path_packfile,
1056 		    pack->packfile, id, offset, tslen, type, size);
1057 		break;
1058 
1059 	default:
1060 		err = got_error(GOT_ERR_NOT_IMPL);
1061 		goto done;
1062 	}
1063 done:
1064 	free(path_packfile);
1065 	return err;
1066 }
1067 
1068 const struct got_error *
1069 got_packfile_open_object(struct got_object **obj, struct got_object_id *id,
1070     struct got_repository *repo)
1071 {
1072 	const struct got_error *err = NULL;
1073 	struct got_packidx_v2_hdr *packidx = NULL;
1074 	int idx;
1075 
1076 	err = search_packidx(&packidx, &idx, repo, id);
1077 	if (err)
1078 		return err;
1079 
1080 	err = open_packed_object(obj, repo, packidx, idx, id);
1081 	if (err)
1082 		return err;
1083 
1084 	err = cache_pack(NULL, (*obj)->path_packfile, packidx, repo);
1085 	return err;
1086 }
1087 
1088 static const struct got_error *
1089 get_delta_chain_max_size(uint64_t *max_size, struct got_delta_chain *deltas)
1090 {
1091 	struct got_delta *delta;
1092 	uint64_t base_size = 0, result_size = 0;
1093 
1094 	*max_size = 0;
1095 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1096 		/* Plain object types are the delta base. */
1097 		if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1098 		    delta->type != GOT_OBJ_TYPE_TREE &&
1099 		    delta->type != GOT_OBJ_TYPE_BLOB &&
1100 		    delta->type != GOT_OBJ_TYPE_TAG) {
1101 			const struct got_error *err;
1102 			err = got_delta_get_sizes(&base_size, &result_size,
1103 			    delta->delta_buf, delta->delta_len);
1104 			if (err)
1105 				return err;
1106 		} else
1107 			base_size = delta->size;
1108 		if (base_size > *max_size)
1109 			*max_size = base_size;
1110 		if (result_size > *max_size)
1111 			*max_size = result_size;
1112 	}
1113 
1114 	return NULL;
1115 }
1116 
1117 static const struct got_error *
1118 dump_delta_chain_to_file(size_t *result_size, struct got_delta_chain *deltas,
1119     FILE *outfile, struct got_pack *pack, struct got_repository *repo)
1120 {
1121 	const struct got_error *err = NULL;
1122 	struct got_delta *delta;
1123 	FILE *base_file = NULL, *accum_file = NULL;
1124 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1125 	size_t accum_size = 0;
1126 	uint64_t max_size;
1127 	int n = 0;
1128 
1129 	*result_size = 0;
1130 
1131 	if (SIMPLEQ_EMPTY(&deltas->entries))
1132 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1133 
1134 	/* We process small enough files entirely in memory for speed. */
1135 	err = get_delta_chain_max_size(&max_size, deltas);
1136 	if (err)
1137 		return err;
1138 	if (max_size < GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
1139 		accum_buf = malloc(max_size);
1140 		if (accum_buf == NULL)
1141 			return got_error(GOT_ERR_NO_MEM);
1142 	} else {
1143 		base_file = got_opentemp();
1144 		if (base_file == NULL)
1145 			return got_error_from_errno();
1146 
1147 		accum_file = got_opentemp();
1148 		if (accum_file == NULL) {
1149 			err = got_error_from_errno();
1150 			fclose(base_file);
1151 			return err;
1152 		}
1153 	}
1154 
1155 	/* Deltas are ordered in ascending order. */
1156 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1157 		if (n == 0) {
1158 			size_t base_len;
1159 
1160 			/* Plain object types are the delta base. */
1161 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1162 			    delta->type != GOT_OBJ_TYPE_TREE &&
1163 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1164 			    delta->type != GOT_OBJ_TYPE_TAG) {
1165 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1166 				goto done;
1167 			}
1168 
1169 			if (fseeko(pack->packfile, delta->offset + delta->tslen,
1170 			    SEEK_SET) != 0) {
1171 				err = got_error_from_errno();
1172 				goto done;
1173 			}
1174 			if (base_file)
1175 				err = got_inflate_to_file(&base_len,
1176 				    pack->packfile, base_file);
1177 			else {
1178 				err = got_inflate_to_mem(&base_buf, &base_len,
1179 				    pack->packfile);
1180 				if (base_len < max_size) {
1181 					uint8_t *p;
1182 					p = reallocarray(base_buf, 1, max_size);
1183 					if (p == NULL) {
1184 						err = got_error(GOT_ERR_NO_MEM);
1185 						goto done;
1186 					}
1187 					base_buf = p;
1188 				}
1189 			}
1190 			if (err)
1191 				goto done;
1192 			n++;
1193 			if (base_file)
1194 				rewind(base_file);
1195 			continue;
1196 		}
1197 
1198 		if (base_buf) {
1199 			err = got_delta_apply_in_mem(base_buf, delta->delta_buf,
1200 			    delta->delta_len, accum_buf, &accum_size);
1201 			n++;
1202 		} else {
1203 			err = got_delta_apply(base_file, delta->delta_buf,
1204 			    delta->delta_len,
1205 			    /* Final delta application writes to output file. */
1206 			    ++n < deltas->nentries ? accum_file : outfile,
1207 			    &accum_size);
1208 		}
1209 		if (err)
1210 			goto done;
1211 
1212 		if (n < deltas->nentries) {
1213 			/* Accumulated delta becomes the new base. */
1214 			if (base_buf) {
1215 				uint8_t *tmp = accum_buf;
1216 				accum_buf = base_buf;
1217 				base_buf = tmp;
1218 			} else {
1219 				FILE *tmp = accum_file;
1220 				accum_file = base_file;
1221 				base_file = tmp;
1222 				rewind(base_file);
1223 				rewind(accum_file);
1224 			}
1225 		}
1226 	}
1227 
1228 done:
1229 	free(base_buf);
1230 	if (accum_buf) {
1231 		size_t len = fwrite(accum_buf, 1, accum_size, outfile);
1232 		free(accum_buf);
1233 		if (len != accum_size)
1234 			return got_ferror(outfile, GOT_ERR_IO);
1235 	}
1236 	if (base_file)
1237 		fclose(base_file);
1238 	if (accum_file)
1239 		fclose(accum_file);
1240 	rewind(outfile);
1241 	if (err == NULL)
1242 		*result_size = accum_size;
1243 	return err;
1244 }
1245 
1246 static const struct got_error *
1247 dump_delta_chain_to_mem(uint8_t **outbuf, size_t *outlen,
1248     struct got_delta_chain *deltas, struct got_pack *pack,
1249     struct got_repository *repo)
1250 {
1251 	const struct got_error *err = NULL;
1252 	struct got_delta *delta;
1253 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1254 	size_t accum_size;
1255 	uint64_t max_size;
1256 	int n = 0;
1257 
1258 	*outbuf = NULL;
1259 	*outlen = 0;
1260 
1261 	if (SIMPLEQ_EMPTY(&deltas->entries))
1262 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1263 
1264 	err = get_delta_chain_max_size(&max_size, deltas);
1265 	if (err)
1266 		return err;
1267 	accum_buf = malloc(max_size);
1268 	if (accum_buf == NULL)
1269 		return got_error(GOT_ERR_NO_MEM);
1270 
1271 	/* Deltas are ordered in ascending order. */
1272 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1273 		if (n == 0) {
1274 			size_t base_len;
1275 
1276 			/* Plain object types are the delta base. */
1277 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1278 			    delta->type != GOT_OBJ_TYPE_TREE &&
1279 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1280 			    delta->type != GOT_OBJ_TYPE_TAG) {
1281 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1282 				goto done;
1283 			}
1284 
1285 			if (fseeko(pack->packfile, delta->offset + delta->tslen,
1286 			    SEEK_SET) != 0) {
1287 				err = got_error_from_errno();
1288 				goto done;
1289 			}
1290 			err = got_inflate_to_mem(&base_buf, &base_len,
1291 			    pack->packfile);
1292 			if (base_len < max_size) {
1293 				uint8_t *p;
1294 				p = reallocarray(base_buf, 1, max_size);
1295 				if (p == NULL) {
1296 					err = got_error(GOT_ERR_NO_MEM);
1297 					goto done;
1298 				}
1299 				base_buf = p;
1300 			}
1301 			if (err)
1302 				goto done;
1303 			n++;
1304 			continue;
1305 		}
1306 
1307 		err = got_delta_apply_in_mem(base_buf, delta->delta_buf,
1308 		    delta->delta_len, accum_buf, &accum_size);
1309 		n++;
1310 		if (err)
1311 			goto done;
1312 
1313 		if (n < deltas->nentries) {
1314 			/* Accumulated delta becomes the new base. */
1315 			uint8_t *tmp = accum_buf;
1316 			accum_buf = base_buf;
1317 			base_buf = tmp;
1318 		}
1319 	}
1320 
1321 done:
1322 	free(base_buf);
1323 	if (err) {
1324 		free(accum_buf);
1325 		*outbuf = NULL;
1326 		*outlen = 0;
1327 	} else {
1328 		*outbuf = accum_buf;
1329 		*outlen = accum_size;
1330 	}
1331 	return err;
1332 }
1333 
1334 const struct got_error *
1335 got_packfile_extract_object(FILE **f, struct got_object *obj,
1336     struct got_repository *repo)
1337 {
1338 	const struct got_error *err = NULL;
1339 	struct got_pack *pack;
1340 
1341 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1342 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1343 
1344 	pack = get_cached_pack(obj->path_packfile, repo);
1345 	if (pack == NULL) {
1346 		err = cache_pack(&pack, obj->path_packfile, NULL, repo);
1347 		if (err)
1348 			goto done;
1349 	}
1350 
1351 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1352 		if (fseeko(pack->packfile, obj->pack_offset, SEEK_SET) != 0) {
1353 			err = got_error_from_errno();
1354 			goto done;
1355 		}
1356 
1357 		if (obj->size < GOT_DELTA_RESULT_SIZE_CACHED_MAX)
1358 			*f = fmemopen(NULL, obj->size, "w+");
1359 		else
1360 			*f = got_opentemp();
1361 		if (*f == NULL) {
1362 			err = got_error(GOT_ERR_FILE_OPEN);
1363 			goto done;
1364 		}
1365 		err = got_inflate_to_file(&obj->size, pack->packfile, *f);
1366 	} else {
1367 		uint64_t max_size;
1368 
1369 		err = get_delta_chain_max_size(&max_size, &obj->deltas);
1370 		if (err)
1371 			return err;
1372 		if (max_size < GOT_DELTA_RESULT_SIZE_CACHED_MAX)
1373 			*f = fmemopen(NULL, max_size, "w+");
1374 		else
1375 			*f = got_opentemp();
1376 		if (*f == NULL) {
1377 			err = got_error(GOT_ERR_FILE_OPEN);
1378 			goto done;
1379 		}
1380 		err = dump_delta_chain_to_file(&obj->size, &obj->deltas, *f,
1381 		    pack, repo);
1382 	}
1383 done:
1384 	if (err && *f) {
1385 		fclose(*f);
1386 		*f = NULL;
1387 	}
1388 	return err;
1389 }
1390 
1391 const struct got_error *
1392 got_packfile_extract_object_to_mem(uint8_t **buf, size_t *len,
1393     struct got_object *obj, struct got_repository *repo)
1394 {
1395 	const struct got_error *err = NULL;
1396 	FILE *packfile = NULL;
1397 	struct got_pack *pack;
1398 
1399 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1400 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1401 
1402 	pack = get_cached_pack(obj->path_packfile, repo);
1403 	if (pack == NULL) {
1404 		err = cache_pack(&pack, obj->path_packfile, NULL, repo);
1405 		if (err)
1406 			goto done;
1407 	}
1408 
1409 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1410 		if (fseeko(pack->packfile, obj->pack_offset, SEEK_SET) != 0) {
1411 			err = got_error_from_errno();
1412 			goto done;
1413 		}
1414 
1415 		err = got_inflate_to_mem(buf, len, pack->packfile);
1416 	} else
1417 		err = dump_delta_chain_to_mem(buf, len, &obj->deltas, pack,
1418 		    repo);
1419 done:
1420 	if (packfile)
1421 		fclose(packfile);
1422 	return err;
1423 }