op public repos

Blob

Date:: Sat May 19 14:57:12 2018 UTC
Message:: move got_opentmp* functions to public API; used from tog
Actions:: History | Blame | Raw File
1 /*
2  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <sys/stat.h>
19 #include <sys/queue.h>
20 
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 		free(pack);
599 	} else if (packp)
600 		*packp = pack;
601 	return err;
602 }
603 
604 struct got_pack *
605 get_cached_pack(const char *path_packfile, struct got_repository *repo)
606 {
607 	struct got_pack *pack = NULL;
608 	int i;
609 
610 	for (i = 0; i < nitems(repo->packs); i++) {
611 		pack = &repo->packs[i];
612 		if (pack->path_packfile == NULL)
613 			break;
614 		if (strcmp(pack->path_packfile, path_packfile) == 0)
615 			return pack;
616 	}
617 
618 	return NULL;
619 }
620 
621 static const struct got_error *
622 parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len, int fd)
623 {
624 	uint8_t t = 0;
625 	uint64_t s = 0;
626 	uint8_t sizeN;
627 	ssize_t n;
628 	int i = 0;
629 
630 	do {
631 		/* We do not support size values which don't fit in 64 bit. */
632 		if (i > 9)
633 			return got_error(GOT_ERR_NO_SPACE);
634 
635 		n = read(fd, &sizeN, sizeof(sizeN));
636 		if (n < 0)
637 			return got_error_from_errno();
638 		if (n != sizeof(sizeN))
639 			return got_error(GOT_ERR_BAD_PACKFILE);
640 
641 		if (i == 0) {
642 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
643 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
644 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
645 		} else {
646 			size_t shift = 4 + 7 * (i - 1);
647 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
648 		}
649 		i++;
650 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
651 
652 	*type = t;
653 	*size = s;
654 	*len = i * sizeof(sizeN);
655 	return NULL;
656 }
657 
658 static const struct got_error *
659 open_plain_object(struct got_object **obj, const char *path_packfile,
660     struct got_object_id *id, uint8_t type, off_t offset, size_t size)
661 {
662 	*obj = calloc(1, sizeof(**obj));
663 	if (*obj == NULL)
664 		return got_error_from_errno();
665 
666 	(*obj)->path_packfile = strdup(path_packfile);
667 	if ((*obj)->path_packfile == NULL) {
668 		const struct got_error *err = got_error_from_errno();
669 		free(*obj);
670 		*obj = NULL;
671 		return err;
672 	}
673 
674 	(*obj)->type = type;
675 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
676 	(*obj)->hdrlen = 0;
677 	(*obj)->size = size;
678 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
679 	(*obj)->pack_offset = offset;
680 
681 	return NULL;
682 }
683 
684 static const struct got_error *
685 parse_negative_offset(int64_t *offset, size_t *len, int fd)
686 {
687 	int64_t o = 0;
688 	uint8_t offN;
689 	ssize_t n;
690 	int i = 0;
691 
692 	do {
693 		/* We do not support offset values which don't fit in 64 bit. */
694 		if (i > 8)
695 			return got_error(GOT_ERR_NO_SPACE);
696 
697 		n = read(fd, &offN, sizeof(offN));
698 		if (n < 0)
699 			return got_error_from_errno();
700 		if (n != sizeof(offN))
701 			return got_error(GOT_ERR_BAD_PACKFILE);
702 
703 		if (i == 0)
704 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
705 		else {
706 			o++;
707 			o <<= 7;
708 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
709 		}
710 		i++;
711 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
712 
713 	*offset = o;
714 	*len = i * sizeof(offN);
715 	return NULL;
716 }
717 
718 static const struct got_error *
719 parse_offset_delta(off_t *base_offset, int fd, off_t offset)
720 {
721 	const struct got_error *err;
722 	int64_t negoffset;
723 	size_t negofflen;
724 
725 	err = parse_negative_offset(&negoffset, &negofflen, fd);
726 	if (err)
727 		return err;
728 
729 	/* Compute the base object's offset (must be in the same pack file). */
730 	*base_offset = (offset - negoffset);
731 	if (*base_offset <= 0)
732 		return got_error(GOT_ERR_BAD_PACKFILE);
733 
734 	return NULL;
735 }
736 
737 static const struct got_error *
738 resolve_delta_chain(struct got_delta_chain *, struct got_repository *,
739     int, size_t, const char *, off_t, size_t, int, size_t, unsigned int);
740 
741 static const struct got_error *
742 add_delta(struct got_delta_chain *deltas, const char *path_packfile,
743     off_t delta_offset, size_t tslen, int delta_type, size_t delta_size,
744     size_t delta_data_offset, uint8_t *delta_buf, size_t delta_len)
745 {
746 	struct got_delta *delta;
747 
748 	delta = got_delta_open(path_packfile, delta_offset, tslen,
749 	    delta_type, delta_size, delta_data_offset, delta_buf,
750 	    delta_len);
751 	if (delta == NULL)
752 		return got_error_from_errno();
753 	/* delta is freed in got_object_close() */
754 	deltas->nentries++;
755 	SIMPLEQ_INSERT_HEAD(&deltas->entries, delta, entry);
756 	return NULL;
757 }
758 
759 static const struct got_error *
760 resolve_offset_delta(struct got_delta_chain *deltas,
761     struct got_repository *repo, int fd, size_t packfile_size,
762     const char *path_packfile, off_t delta_offset, size_t tslen,
763     int delta_type, size_t delta_size, unsigned int recursion)
764 
765 {
766 	const struct got_error *err;
767 	off_t base_offset;
768 	uint8_t base_type;
769 	uint64_t base_size;
770 	size_t base_tslen;
771 	off_t delta_data_offset;
772 	uint8_t *delta_buf;
773 	size_t delta_len;
774 
775 	err = parse_offset_delta(&base_offset, fd, delta_offset);
776 	if (err)
777 		return err;
778 
779 	delta_data_offset = lseek(fd, 0, SEEK_CUR);
780 	if (delta_data_offset == -1)
781 		return got_error_from_errno();
782 
783 	err = got_inflate_to_mem_fd(&delta_buf, &delta_len, fd);
784 	if (err)
785 		return err;
786 
787 	err = add_delta(deltas, path_packfile, delta_offset, tslen,
788 	    delta_type, delta_size, delta_data_offset, delta_buf, delta_len);
789 	if (err)
790 		return err;
791 
792 	/* An offset delta must be in the same packfile. */
793 	if (base_offset >= packfile_size)
794 		return got_error(GOT_ERR_PACK_OFFSET);
795 	if (lseek(fd, base_offset, SEEK_SET) == -1)
796 		return got_error_from_errno();
797 
798 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
799 	    fd);
800 	if (err)
801 		return err;
802 
803 	return resolve_delta_chain(deltas, repo, fd, packfile_size,
804 	    path_packfile, base_offset, base_tslen, base_type, base_size,
805 	    recursion - 1);
806 }
807 
808 static const struct got_error *
809 resolve_ref_delta(struct got_delta_chain *deltas, struct got_repository *repo,
810     int fd, const char *path_packfile, off_t delta_offset,
811     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
812 {
813 	const struct got_error *err;
814 	struct got_object_id id;
815 	struct got_packidx_v2_hdr *packidx;
816 	int idx;
817 	off_t base_offset;
818 	uint8_t base_type;
819 	uint64_t base_size;
820 	size_t base_tslen;
821 	ssize_t n;
822 	char *path_base_packfile;
823 	struct got_pack *base_pack;
824 	off_t delta_data_offset;
825 	uint8_t *delta_buf;
826 	size_t delta_len;
827 
828 	n = read(fd, &id, sizeof(id));
829 	if (n < 0)
830 		return got_error_from_errno();
831 	if (n != sizeof(id))
832 		return got_error(GOT_ERR_BAD_PACKFILE);
833 
834 	delta_data_offset = lseek(fd, 0, SEEK_CUR);
835 	if (delta_data_offset == -1)
836 		return got_error_from_errno();
837 
838 	err = got_inflate_to_mem_fd(&delta_buf, &delta_len, fd);
839 	if (err)
840 		return err;
841 
842 	err = add_delta(deltas, path_packfile, delta_offset, tslen,
843 	    delta_type, delta_size, delta_data_offset, delta_buf, delta_len);
844 	if (err)
845 		return err;
846 
847 	err = search_packidx(&packidx, &idx, repo, &id);
848 	if (err)
849 		return err;
850 
851 	base_offset = get_object_offset(packidx, idx);
852 	if (base_offset == (uint64_t)-1) {
853 		return got_error(GOT_ERR_BAD_PACKIDX);
854 	}
855 
856 	err = get_packfile_path(&path_base_packfile, repo, packidx);
857 	if (err)
858 		return err;
859 
860 	base_pack = get_cached_pack(path_base_packfile, repo);
861 	if (base_pack == NULL) {
862 		err = cache_pack(&base_pack, path_base_packfile, NULL, repo);
863 		if (err)
864 			goto done;
865 	}
866 
867 	if (base_offset >= base_pack->filesize) {
868 		err = got_error(GOT_ERR_PACK_OFFSET);
869 		goto done;
870 	}
871 	if (lseek(base_pack->fd, base_offset, SEEK_SET) == -1) {
872 		err = got_error_from_errno();
873 		goto done;
874 	}
875 
876 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
877 	    base_pack->fd);
878 	if (err)
879 		goto done;
880 
881 	err = resolve_delta_chain(deltas, repo, base_pack->fd,
882 	    base_pack->filesize, path_base_packfile, base_offset,
883 	    base_tslen, base_type, base_size, recursion - 1);
884 done:
885 	free(path_base_packfile);
886 	return err;
887 }
888 
889 static const struct got_error *
890 resolve_delta_chain(struct got_delta_chain *deltas, struct got_repository *repo,
891     int fd, size_t packfile_size, const char *path_packfile, off_t delta_offset,
892     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
893 {
894 	const struct got_error *err = NULL;
895 
896 	if (--recursion == 0)
897 		return got_error(GOT_ERR_RECURSION);
898 
899 	switch (delta_type) {
900 	case GOT_OBJ_TYPE_COMMIT:
901 	case GOT_OBJ_TYPE_TREE:
902 	case GOT_OBJ_TYPE_BLOB:
903 	case GOT_OBJ_TYPE_TAG:
904 		/* Plain types are the final delta base. Recursion ends. */
905 		err = add_delta(deltas, path_packfile, delta_offset, tslen,
906 		    delta_type, delta_size, 0, NULL, 0);
907 		break;
908 	case GOT_OBJ_TYPE_OFFSET_DELTA:
909 		err = resolve_offset_delta(deltas, repo, fd, packfile_size,
910 		    path_packfile, delta_offset, tslen, delta_type, delta_size,
911 		    recursion - 1);
912 		break;
913 	case GOT_OBJ_TYPE_REF_DELTA:
914 		err = resolve_ref_delta(deltas, repo, fd, path_packfile,
915 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
916 		break;
917 	default:
918 		return got_error(GOT_ERR_OBJ_TYPE);
919 	}
920 
921 	return err;
922 }
923 
924 static const struct got_error *
925 open_delta_object(struct got_object **obj, struct got_repository *repo,
926     struct got_packidx_v2_hdr *packidx, const char *path_packfile,
927     int fd, size_t packfile_size, struct got_object_id *id, off_t offset,
928     size_t tslen, int delta_type, size_t delta_size)
929 {
930 	const struct got_error *err = NULL;
931 	int resolved_type;
932 
933 	*obj = calloc(1, sizeof(**obj));
934 	if (*obj == NULL)
935 		return got_error_from_errno();
936 
937 	(*obj)->flags = 0;
938 	(*obj)->hdrlen = 0;
939 	(*obj)->size = 0; /* Not known because deltas aren't applied yet. */
940 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
941 	(*obj)->pack_offset = offset + tslen;
942 
943 	(*obj)->path_packfile = strdup(path_packfile);
944 	if ((*obj)->path_packfile == NULL) {
945 		err = got_error_from_errno();
946 		goto done;
947 	}
948 	(*obj)->flags |= GOT_OBJ_FLAG_PACKED;
949 
950 	SIMPLEQ_INIT(&(*obj)->deltas.entries);
951 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
952 
953 	err = resolve_delta_chain(&(*obj)->deltas, repo, fd, packfile_size,
954 	    path_packfile, offset, tslen, delta_type, delta_size,
955 	    GOT_DELTA_CHAIN_RECURSION_MAX);
956 	if (err)
957 		goto done;
958 
959 	err = got_delta_chain_get_base_type(&resolved_type, &(*obj)->deltas);
960 	if (err)
961 		goto done;
962 	(*obj)->type = resolved_type;
963 
964 done:
965 	if (err) {
966 		got_object_close(*obj);
967 		*obj = NULL;
968 	}
969 	return err;
970 }
971 
972 static const struct got_error *
973 open_packed_object(struct got_object **obj, struct got_repository *repo,
974     struct got_packidx_v2_hdr *packidx, int idx, struct got_object_id *id)
975 {
976 	const struct got_error *err = NULL;
977 	off_t offset;
978 	char *path_packfile;
979 	struct got_pack *pack;
980 	uint8_t type;
981 	uint64_t size;
982 	size_t tslen;
983 
984 	*obj = NULL;
985 
986 	offset = get_object_offset(packidx, idx);
987 	if (offset == (uint64_t)-1)
988 		return got_error(GOT_ERR_BAD_PACKIDX);
989 
990 	err = get_packfile_path(&path_packfile, repo, packidx);
991 	if (err)
992 		return err;
993 
994 	pack = get_cached_pack(path_packfile, repo);
995 	if (pack == NULL) {
996 		err = cache_pack(&pack, path_packfile, packidx, repo);
997 		if (err)
998 			goto done;
999 	}
1000 
1001 	if (offset >= pack->filesize) {
1002 		err = got_error(GOT_ERR_PACK_OFFSET);
1003 		goto done;
1004 	}
1005 	if (lseek(pack->fd, offset, SEEK_SET) == -1) {
1006 		err = got_error_from_errno();
1007 		goto done;
1008 	}
1009 
1010 	err = parse_object_type_and_size(&type, &size, &tslen, pack->fd);
1011 	if (err)
1012 		goto done;
1013 
1014 	switch (type) {
1015 	case GOT_OBJ_TYPE_COMMIT:
1016 	case GOT_OBJ_TYPE_TREE:
1017 	case GOT_OBJ_TYPE_BLOB:
1018 	case GOT_OBJ_TYPE_TAG:
1019 		err = open_plain_object(obj, path_packfile, id, type,
1020 		    offset + tslen, size);
1021 		break;
1022 
1023 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1024 	case GOT_OBJ_TYPE_REF_DELTA:
1025 		err = open_delta_object(obj, repo, packidx, path_packfile,
1026 		    pack->fd, pack->filesize, id, offset, tslen, type, size);
1027 		break;
1028 
1029 	default:
1030 		err = got_error(GOT_ERR_OBJ_TYPE);
1031 		goto done;
1032 	}
1033 done:
1034 	free(path_packfile);
1035 	return err;
1036 }
1037 
1038 const struct got_error *
1039 got_packfile_open_object(struct got_object **obj, struct got_object_id *id,
1040     struct got_repository *repo)
1041 {
1042 	const struct got_error *err = NULL;
1043 	struct got_packidx_v2_hdr *packidx = NULL;
1044 	int idx;
1045 
1046 	err = search_packidx(&packidx, &idx, repo, id);
1047 	if (err)
1048 		return err;
1049 
1050 	err = open_packed_object(obj, repo, packidx, idx, id);
1051 	if (err)
1052 		return err;
1053 
1054 	err = cache_pack(NULL, (*obj)->path_packfile, packidx, repo);
1055 	return err;
1056 }
1057 
1058 static const struct got_error *
1059 get_delta_chain_max_size(uint64_t *max_size, struct got_delta_chain *deltas)
1060 {
1061 	struct got_delta *delta;
1062 	uint64_t base_size = 0, result_size = 0;
1063 
1064 	*max_size = 0;
1065 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1066 		/* Plain object types are the delta base. */
1067 		if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1068 		    delta->type != GOT_OBJ_TYPE_TREE &&
1069 		    delta->type != GOT_OBJ_TYPE_BLOB &&
1070 		    delta->type != GOT_OBJ_TYPE_TAG) {
1071 			const struct got_error *err;
1072 			err = got_delta_get_sizes(&base_size, &result_size,
1073 			    delta->delta_buf, delta->delta_len);
1074 			if (err)
1075 				return err;
1076 		} else
1077 			base_size = delta->size;
1078 		if (base_size > *max_size)
1079 			*max_size = base_size;
1080 		if (result_size > *max_size)
1081 			*max_size = result_size;
1082 	}
1083 
1084 	return NULL;
1085 }
1086 
1087 static const struct got_error *
1088 dump_delta_chain_to_file(size_t *result_size, struct got_delta_chain *deltas,
1089     FILE *outfile, struct got_repository *repo)
1090 {
1091 	const struct got_error *err = NULL;
1092 	struct got_delta *delta;
1093 	FILE *base_file = NULL, *accum_file = NULL;
1094 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1095 	size_t accum_size = 0;
1096 	uint64_t max_size;
1097 	int n = 0;
1098 
1099 	*result_size = 0;
1100 
1101 	if (SIMPLEQ_EMPTY(&deltas->entries))
1102 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1103 
1104 	/* We process small enough files entirely in memory for speed. */
1105 	err = get_delta_chain_max_size(&max_size, deltas);
1106 	if (err)
1107 		return err;
1108 	if (max_size < GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
1109 		accum_buf = malloc(max_size);
1110 		if (accum_buf == NULL)
1111 			return got_error_from_errno();
1112 	} else {
1113 		base_file = got_opentemp();
1114 		if (base_file == NULL)
1115 			return got_error_from_errno();
1116 
1117 		accum_file = got_opentemp();
1118 		if (accum_file == NULL) {
1119 			err = got_error_from_errno();
1120 			fclose(base_file);
1121 			return err;
1122 		}
1123 	}
1124 
1125 	/* Deltas are ordered in ascending order. */
1126 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1127 		if (n == 0) {
1128 			struct got_pack *pack;
1129 			size_t base_len;
1130 			off_t delta_data_offset;
1131 
1132 			/* Plain object types are the delta base. */
1133 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1134 			    delta->type != GOT_OBJ_TYPE_TREE &&
1135 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1136 			    delta->type != GOT_OBJ_TYPE_TAG) {
1137 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1138 				goto done;
1139 			}
1140 
1141 			pack = get_cached_pack(delta->path_packfile, repo);
1142 			if (pack == NULL) {
1143 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1144 				goto done;
1145 			}
1146 
1147 			delta_data_offset = delta->offset + delta->tslen;
1148 			if (delta_data_offset >= pack->filesize) {
1149 				err = got_error(GOT_ERR_PACK_OFFSET);
1150 				goto done;
1151 			}
1152 			if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1) {
1153 				err = got_error_from_errno();
1154 				goto done;
1155 			}
1156 			if (base_file)
1157 				err = got_inflate_to_file_fd(&base_len,
1158 				    pack->fd, base_file);
1159 			else {
1160 				err = got_inflate_to_mem_fd(&base_buf, &base_len,
1161 				    pack->fd);
1162 				if (base_len < max_size) {
1163 					uint8_t *p;
1164 					p = reallocarray(base_buf, 1, max_size);
1165 					if (p == NULL) {
1166 						err = got_error_from_errno();
1167 						goto done;
1168 					}
1169 					base_buf = p;
1170 				}
1171 			}
1172 			if (err)
1173 				goto done;
1174 			n++;
1175 			if (base_file)
1176 				rewind(base_file);
1177 			continue;
1178 		}
1179 
1180 		if (base_buf) {
1181 			err = got_delta_apply_in_mem(base_buf, delta->delta_buf,
1182 			    delta->delta_len, accum_buf, &accum_size);
1183 			n++;
1184 		} else {
1185 			err = got_delta_apply(base_file, delta->delta_buf,
1186 			    delta->delta_len,
1187 			    /* Final delta application writes to output file. */
1188 			    ++n < deltas->nentries ? accum_file : outfile,
1189 			    &accum_size);
1190 		}
1191 		if (err)
1192 			goto done;
1193 
1194 		if (n < deltas->nentries) {
1195 			/* Accumulated delta becomes the new base. */
1196 			if (base_buf) {
1197 				uint8_t *tmp = accum_buf;
1198 				accum_buf = base_buf;
1199 				base_buf = tmp;
1200 			} else {
1201 				FILE *tmp = accum_file;
1202 				accum_file = base_file;
1203 				base_file = tmp;
1204 				rewind(base_file);
1205 				rewind(accum_file);
1206 			}
1207 		}
1208 	}
1209 
1210 done:
1211 	free(base_buf);
1212 	if (accum_buf) {
1213 		size_t len = fwrite(accum_buf, 1, accum_size, outfile);
1214 		free(accum_buf);
1215 		if (len != accum_size)
1216 			return got_ferror(outfile, GOT_ERR_IO);
1217 	}
1218 	if (base_file)
1219 		fclose(base_file);
1220 	if (accum_file)
1221 		fclose(accum_file);
1222 	rewind(outfile);
1223 	if (err == NULL)
1224 		*result_size = accum_size;
1225 	return err;
1226 }
1227 
1228 static const struct got_error *
1229 dump_delta_chain_to_mem(uint8_t **outbuf, size_t *outlen,
1230     struct got_delta_chain *deltas, struct got_repository *repo)
1231 {
1232 	const struct got_error *err = NULL;
1233 	struct got_delta *delta;
1234 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1235 	size_t accum_size;
1236 	uint64_t max_size;
1237 	int n = 0;
1238 
1239 	*outbuf = NULL;
1240 	*outlen = 0;
1241 
1242 	if (SIMPLEQ_EMPTY(&deltas->entries))
1243 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1244 
1245 	err = get_delta_chain_max_size(&max_size, deltas);
1246 	if (err)
1247 		return err;
1248 	accum_buf = malloc(max_size);
1249 	if (accum_buf == NULL)
1250 		return got_error_from_errno();
1251 
1252 	/* Deltas are ordered in ascending order. */
1253 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1254 		if (n == 0) {
1255 			struct got_pack *pack;
1256 			size_t base_len;
1257 			size_t delta_data_offset;
1258 
1259 			/* Plain object types are the delta base. */
1260 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1261 			    delta->type != GOT_OBJ_TYPE_TREE &&
1262 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1263 			    delta->type != GOT_OBJ_TYPE_TAG) {
1264 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1265 				goto done;
1266 			}
1267 
1268 			pack = get_cached_pack(delta->path_packfile, repo);
1269 			if (pack == NULL) {
1270 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1271 				goto done;
1272 			}
1273 
1274 			delta_data_offset = delta->offset + delta->tslen;
1275 			if (delta_data_offset >= pack->filesize) {
1276 				err = got_error(GOT_ERR_PACK_OFFSET);
1277 				goto done;
1278 			}
1279 			if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1) {
1280 				err = got_error_from_errno();
1281 				goto done;
1282 			}
1283 			err = got_inflate_to_mem_fd(&base_buf, &base_len,
1284 			    pack->fd);
1285 			if (base_len < max_size) {
1286 				uint8_t *p;
1287 				p = reallocarray(base_buf, 1, max_size);
1288 				if (p == NULL) {
1289 					err = got_error_from_errno();
1290 					goto done;
1291 				}
1292 				base_buf = p;
1293 			}
1294 			if (err)
1295 				goto done;
1296 			n++;
1297 			continue;
1298 		}
1299 
1300 		err = got_delta_apply_in_mem(base_buf, delta->delta_buf,
1301 		    delta->delta_len, accum_buf, &accum_size);
1302 		n++;
1303 		if (err)
1304 			goto done;
1305 
1306 		if (n < deltas->nentries) {
1307 			/* Accumulated delta becomes the new base. */
1308 			uint8_t *tmp = accum_buf;
1309 			accum_buf = base_buf;
1310 			base_buf = tmp;
1311 		}
1312 	}
1313 
1314 done:
1315 	free(base_buf);
1316 	if (err) {
1317 		free(accum_buf);
1318 		*outbuf = NULL;
1319 		*outlen = 0;
1320 	} else {
1321 		*outbuf = accum_buf;
1322 		*outlen = accum_size;
1323 	}
1324 	return err;
1325 }
1326 
1327 const struct got_error *
1328 got_packfile_extract_object(FILE **f, struct got_object *obj,
1329     struct got_repository *repo)
1330 {
1331 	const struct got_error *err = NULL;
1332 
1333 	*f = NULL;
1334 
1335 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1336 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1337 
1338 	*f = got_opentemp();
1339 	if (*f == NULL) {
1340 		err = got_error_from_errno();
1341 		goto done;
1342 	}
1343 
1344 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1345 		struct got_pack *pack;
1346 
1347 		pack = get_cached_pack(obj->path_packfile, repo);
1348 		if (pack == NULL) {
1349 			err = cache_pack(&pack, obj->path_packfile, NULL, repo);
1350 			if (err)
1351 				goto done;
1352 		}
1353 
1354 		if (obj->pack_offset >= pack->filesize) {
1355 			err = got_error(GOT_ERR_PACK_OFFSET);
1356 			goto done;
1357 		}
1358 		if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1) {
1359 			err = got_error_from_errno();
1360 			goto done;
1361 		}
1362 
1363 		err = got_inflate_to_file_fd(&obj->size, pack->fd, *f);
1364 	} else
1365 		err = dump_delta_chain_to_file(&obj->size,
1366 		    &obj->deltas, *f, repo);
1367 done:
1368 	if (err && *f) {
1369 		fclose(*f);
1370 		*f = NULL;
1371 	}
1372 	return err;
1373 }
1374 
1375 const struct got_error *
1376 got_packfile_extract_object_to_mem(uint8_t **buf, size_t *len,
1377     struct got_object *obj, struct got_repository *repo)
1378 {
1379 	const struct got_error *err = NULL;
1380 
1381 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1382 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1383 
1384 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1385 		struct got_pack *pack;
1386 
1387 		pack = get_cached_pack(obj->path_packfile, repo);
1388 		if (pack == NULL) {
1389 			err = cache_pack(&pack, obj->path_packfile, NULL, repo);
1390 			if (err)
1391 				goto done;
1392 		}
1393 
1394 		if (obj->pack_offset >= pack->filesize) {
1395 			err = got_error(GOT_ERR_PACK_OFFSET);
1396 			goto done;
1397 		}
1398 		if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1) {
1399 			err = got_error_from_errno();
1400 			goto done;
1401 		}
1402 
1403 		err = got_inflate_to_mem_fd(buf, len, pack->fd);
1404 	} else
1405 		err = dump_delta_chain_to_mem(buf, len, &obj->deltas, repo);
1406 done:
1407 	return err;
1408 }