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Date:: Sun Sep 22 08:51:10 2019 UTC
Message:: plug error leak in got_packidx_init_hdr(); found by jj@ with scan-build
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1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <sys/stat.h>
19 #include <sys/queue.h>
20 #include <sys/uio.h>
21 #include <sys/mman.h>
22 
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 #include <imsg.h>
34 
35 #include "got_error.h"
36 #include "got_object.h"
37 #include "got_opentemp.h"
38 #include "got_path.h"
39 
40 #include "got_lib_sha1.h"
41 #include "got_lib_delta.h"
42 #include "got_lib_inflate.h"
43 #include "got_lib_object.h"
44 #include "got_lib_object_parse.h"
45 #include "got_lib_privsep.h"
46 #include "got_lib_pack.h"
47 
48 #ifndef nitems
49 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
50 #endif
51 
52 #ifndef MIN
53 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
54 #endif
55 
56 static const struct got_error *
57 verify_fanout_table(uint32_t *fanout_table)
58 {
59 	int i;
60 
61 	for (i = 0; i < 0xff - 1; i++) {
62 		if (be32toh(fanout_table[i]) > be32toh(fanout_table[i + 1]))
63 			return got_error(GOT_ERR_BAD_PACKIDX);
64 	}
65 
66 	return NULL;
67 }
68 
69 const struct got_error *
70 got_packidx_init_hdr(struct got_packidx *p, int verify)
71 {
72 	const struct got_error *err = NULL;
73 	struct got_packidx_v2_hdr *h;
74 	SHA1_CTX ctx;
75 	uint8_t sha1[SHA1_DIGEST_LENGTH];
76 	size_t nobj, len_fanout, len_ids, offset, remain;
77 	ssize_t n;
78 
79 	SHA1Init(&ctx);
80 
81 	h = &p->hdr;
82 	offset = 0;
83 	remain = p->len;
84 
85 	if (remain < sizeof(*h->magic)) {
86 		err = got_error(GOT_ERR_BAD_PACKIDX);
87 		goto done;
88 	}
89 	if (p->map)
90 		h->magic = (uint32_t *)(p->map + offset);
91 	else {
92 		h->magic = malloc(sizeof(*h->magic));
93 		if (h->magic == NULL) {
94 			err = got_error_from_errno("malloc");
95 			goto done;
96 		}
97 		n = read(p->fd, h->magic, sizeof(*h->magic));
98 		if (n < 0) {
99 			err = got_error_from_errno("read");
100 			goto done;
101 		} else if (n != sizeof(*h->magic)) {
102 			err = got_error(GOT_ERR_BAD_PACKIDX);
103 			goto done;
104 		}
105 	}
106 	if (betoh32(*h->magic) != GOT_PACKIDX_V2_MAGIC) {
107 		err = got_error(GOT_ERR_BAD_PACKIDX);
108 		goto done;
109 	}
110 	offset += sizeof(*h->magic);
111 	remain -= sizeof(*h->magic);
112 
113 	if (verify)
114 		SHA1Update(&ctx, (uint8_t *)h->magic, sizeof(*h->magic));
115 
116 	if (remain < sizeof(*h->version)) {
117 		err = got_error(GOT_ERR_BAD_PACKIDX);
118 		goto done;
119 	}
120 	if (p->map)
121 		h->version = (uint32_t *)(p->map + offset);
122 	else {
123 		h->version = malloc(sizeof(*h->version));
124 		if (h->version == NULL) {
125 			err = got_error_from_errno("malloc");
126 			goto done;
127 		}
128 		n = read(p->fd, h->version, sizeof(*h->version));
129 		if (n < 0)
130 			err = got_error_from_errno("read");
131 		else if (n != sizeof(*h->version)) {
132 			err = got_error(GOT_ERR_BAD_PACKIDX);
133 			goto done;
134 		}
135 	}
136 	if (betoh32(*h->version) != GOT_PACKIDX_VERSION) {
137 		err = got_error(GOT_ERR_BAD_PACKIDX);
138 		goto done;
139 	}
140 	offset += sizeof(*h->version);
141 	remain -= sizeof(*h->version);
142 
143 	if (verify)
144 		SHA1Update(&ctx, (uint8_t *)h->version, sizeof(*h->version));
145 
146 	len_fanout =
147 	    sizeof(*h->fanout_table) * GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS;
148 	if (remain < len_fanout) {
149 		err = got_error(GOT_ERR_BAD_PACKIDX);
150 		goto done;
151 	}
152 	if (p->map)
153 		h->fanout_table = (uint32_t *)(p->map + offset);
154 	else {
155 		h->fanout_table = malloc(len_fanout);
156 		if (h->fanout_table == NULL) {
157 			err = got_error_from_errno("malloc");
158 			goto done;
159 		}
160 		n = read(p->fd, h->fanout_table, len_fanout);
161 		if (n < 0)
162 			err = got_error_from_errno("read");
163 		else if (n != len_fanout) {
164 			err = got_error(GOT_ERR_BAD_PACKIDX);
165 			goto done;
166 		}
167 	}
168 	err = verify_fanout_table(h->fanout_table);
169 	if (err)
170 		goto done;
171 	if (verify)
172 		SHA1Update(&ctx, (uint8_t *)h->fanout_table, len_fanout);
173 	offset += len_fanout;
174 	remain -= len_fanout;
175 
176 	nobj = betoh32(h->fanout_table[0xff]);
177 	len_ids = nobj * sizeof(*h->sorted_ids);
178 	if (len_ids <= nobj || len_ids > remain) {
179 		err = got_error(GOT_ERR_BAD_PACKIDX);
180 		goto done;
181 	}
182 	if (p->map)
183 		h->sorted_ids =
184 		    (struct got_packidx_object_id *)((uint8_t*)(p->map + offset));
185 	else {
186 		h->sorted_ids = malloc(len_ids);
187 		if (h->sorted_ids == NULL) {
188 			err = got_error(GOT_ERR_BAD_PACKIDX);
189 			goto done;
190 		}
191 		n = read(p->fd, h->sorted_ids, len_ids);
192 		if (n < 0)
193 			err = got_error_from_errno("read");
194 		else if (n != len_ids) {
195 			err = got_error(GOT_ERR_BAD_PACKIDX);
196 			goto done;
197 		}
198 	}
199 	if (verify)
200 		SHA1Update(&ctx, (uint8_t *)h->sorted_ids, len_ids);
201 	offset += len_ids;
202 	remain -= len_ids;
203 
204 	if (remain < nobj * sizeof(*h->crc32)) {
205 		err = got_error(GOT_ERR_BAD_PACKIDX);
206 		goto done;
207 	}
208 	if (p->map)
209 		h->crc32 = (uint32_t *)((uint8_t*)(p->map + offset));
210 	else {
211 		h->crc32 = malloc(nobj * sizeof(*h->crc32));
212 		if (h->crc32 == NULL) {
213 			err = got_error_from_errno("malloc");
214 			goto done;
215 		}
216 		n = read(p->fd, h->crc32, nobj * sizeof(*h->crc32));
217 		if (n < 0)
218 			err = got_error_from_errno("read");
219 		else if (n != nobj * sizeof(*h->crc32)) {
220 			err = got_error(GOT_ERR_BAD_PACKIDX);
221 			goto done;
222 		}
223 	}
224 	if (verify)
225 		SHA1Update(&ctx, (uint8_t *)h->crc32, nobj * sizeof(*h->crc32));
226 	remain -= nobj * sizeof(*h->crc32);
227 	offset += nobj * sizeof(*h->crc32);
228 
229 	if (remain < nobj * sizeof(*h->offsets)) {
230 		err = got_error(GOT_ERR_BAD_PACKIDX);
231 		goto done;
232 	}
233 	if (p->map)
234 		h->offsets = (uint32_t *)((uint8_t*)(p->map + offset));
235 	else {
236 		h->offsets = malloc(nobj * sizeof(*h->offsets));
237 		if (h->offsets == NULL) {
238 			err = got_error_from_errno("malloc");
239 			goto done;
240 		}
241 		n = read(p->fd, h->offsets, nobj * sizeof(*h->offsets));
242 		if (n < 0)
243 			err = got_error_from_errno("read");
244 		else if (n != nobj * sizeof(*h->offsets)) {
245 			err = got_error(GOT_ERR_BAD_PACKIDX);
246 			goto done;
247 		}
248 	}
249 	if (verify)
250 		SHA1Update(&ctx, (uint8_t *)h->offsets,
251 		    nobj * sizeof(*h->offsets));
252 	remain -= nobj * sizeof(*h->offsets);
253 	offset += nobj * sizeof(*h->offsets);
254 
255 	/* Large file offsets are contained only in files > 2GB. */
256 	if (p->len <= 0x80000000)
257 		goto checksum;
258 
259 	if (remain < nobj * sizeof(*h->large_offsets)) {
260 		err = got_error(GOT_ERR_BAD_PACKIDX);
261 		goto done;
262 	}
263 	if (p->map)
264 		h->large_offsets = (uint64_t *)((uint8_t*)(p->map + offset));
265 	else {
266 		h->large_offsets = malloc(nobj * sizeof(*h->large_offsets));
267 		if (h->large_offsets == NULL) {
268 			err = got_error_from_errno("malloc");
269 			goto done;
270 		}
271 		n = read(p->fd, h->large_offsets,
272 		    nobj * sizeof(*h->large_offsets));
273 		if (n < 0)
274 			err = got_error_from_errno("read");
275 		else if (n != nobj * sizeof(*h->large_offsets)) {
276 			err = got_error(GOT_ERR_BAD_PACKIDX);
277 			goto done;
278 		}
279 	}
280 	if (verify)
281 		SHA1Update(&ctx, (uint8_t*)h->large_offsets,
282 		    nobj * sizeof(*h->large_offsets));
283 	remain -= nobj * sizeof(*h->large_offsets);
284 	offset += nobj * sizeof(*h->large_offsets);
285 
286 checksum:
287 	if (remain < sizeof(*h->trailer)) {
288 		err = got_error(GOT_ERR_BAD_PACKIDX);
289 		goto done;
290 	}
291 	if (p->map)
292 		h->trailer =
293 		    (struct got_packidx_trailer *)((uint8_t*)(p->map + offset));
294 	else {
295 		h->trailer = malloc(sizeof(*h->trailer));
296 		if (h->trailer == NULL) {
297 			err = got_error_from_errno("malloc");
298 			goto done;
299 		}
300 		n = read(p->fd, h->trailer, sizeof(*h->trailer));
301 		if (n < 0)
302 			err = got_error_from_errno("read");
303 		else if (n != sizeof(*h->trailer)) {
304 			err = got_error(GOT_ERR_BAD_PACKIDX);
305 			goto done;
306 		}
307 	}
308 	if (verify) {
309 		SHA1Update(&ctx, h->trailer->packfile_sha1, SHA1_DIGEST_LENGTH);
310 		SHA1Final(sha1, &ctx);
311 		if (memcmp(h->trailer->packidx_sha1, sha1,
312 		    SHA1_DIGEST_LENGTH) != 0)
313 			err = got_error(GOT_ERR_PACKIDX_CSUM);
314 	}
315 done:
316 	return err;
317 }
318 
319 const struct got_error *
320 got_packidx_open(struct got_packidx **packidx, const char *path, int verify)
321 {
322 	const struct got_error *err = NULL;
323 	struct got_packidx *p;
324 	struct stat sb;
325 
326 	*packidx = NULL;
327 
328 	p = calloc(1, sizeof(*p));
329 	if (p == NULL)
330 		return got_error_from_errno("calloc");
331 
332 	p->fd = open(path, O_RDONLY | O_NOFOLLOW);
333 	if (p->fd == -1) {
334 		err = got_error_from_errno2("open", path);
335 		free(p);
336 		return err;
337 	}
338 
339 	if (fstat(p->fd, &sb) != 0) {
340 		err = got_error_from_errno2("fstat", path);
341 		close(p->fd);
342 		free(p);
343 		return err;
344 	}
345 	p->len = sb.st_size;
346 	if (p->len < sizeof(p->hdr)) {
347 		err = got_error(GOT_ERR_BAD_PACKIDX);
348 		close(p->fd);
349 		free(p);
350 		return err;
351 	}
352 
353 	p->path_packidx = strdup(path);
354 	if (p->path_packidx == NULL) {
355 		err = got_error_from_errno("strdup");
356 		goto done;
357 	}
358 
359 #ifndef GOT_PACK_NO_MMAP
360 	p->map = mmap(NULL, p->len, PROT_READ, MAP_PRIVATE, p->fd, 0);
361 	if (p->map == MAP_FAILED) {
362 		if (errno != ENOMEM) {
363 			err = got_error_from_errno("mmap");
364 			goto done;
365 		}
366 		p->map = NULL; /* fall back to read(2) */
367 	}
368 #endif
369 
370 	err = got_packidx_init_hdr(p, verify);
371 done:
372 	if (err)
373 		got_packidx_close(p);
374 	else
375 		*packidx = p;
376 
377 	return err;
378 }
379 
380 const struct got_error *
381 got_packidx_close(struct got_packidx *packidx)
382 {
383 	const struct got_error *err = NULL;
384 
385 	free(packidx->path_packidx);
386 	if (packidx->map) {
387 		if (munmap(packidx->map, packidx->len) == -1)
388 			err = got_error_from_errno("munmap");
389 	} else {
390 		free(packidx->hdr.magic);
391 		free(packidx->hdr.version);
392 		free(packidx->hdr.fanout_table);
393 		free(packidx->hdr.sorted_ids);
394 		free(packidx->hdr.crc32);
395 		free(packidx->hdr.offsets);
396 		free(packidx->hdr.large_offsets);
397 		free(packidx->hdr.trailer);
398 	}
399 	if (close(packidx->fd) != 0 && err == NULL)
400 		err = got_error_from_errno("close");
401 	free(packidx);
402 
403 	return err;
404 }
405 
406 static off_t
407 get_object_offset(struct got_packidx *packidx, int idx)
408 {
409 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
410 	uint32_t offset = betoh32(packidx->hdr.offsets[idx]);
411 	if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
412 		uint64_t loffset;
413 		idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
414 		if (idx < 0 || idx > totobj ||
415 		    packidx->hdr.large_offsets == NULL)
416 			return -1;
417 		loffset = betoh64(packidx->hdr.large_offsets[idx]);
418 		return (loffset > INT64_MAX ? -1 : (off_t)loffset);
419 	}
420 	return (off_t)(offset & GOT_PACKIDX_OFFSET_VAL_MASK);
421 }
422 
423 int
424 got_packidx_get_object_idx(struct got_packidx *packidx, struct got_object_id *id)
425 {
426 	u_int8_t id0 = id->sha1[0];
427 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
428 	int left = 0, right = totobj - 1;
429 
430 	if (id0 > 0)
431 		left = betoh32(packidx->hdr.fanout_table[id0 - 1]);
432 
433 	while (left <= right) {
434 		struct got_packidx_object_id *oid;
435 		int i, cmp;
436 
437 		i = ((left + right) / 2);
438 		oid = &packidx->hdr.sorted_ids[i];
439 		cmp = memcmp(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
440 		if (cmp == 0)
441 			return i;
442 		else if (cmp > 0)
443 			left = i + 1;
444 		else if (cmp < 0)
445 			right = i - 1;
446 	}
447 
448 	return -1;
449 }
450 
451 const struct got_error *
452 got_packidx_match_id_str_prefix(struct got_object_id_queue *matched_ids,
453     struct got_packidx *packidx, const char *id_str_prefix)
454 {
455 	const struct got_error *err = NULL;
456 	u_int8_t id0;
457 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
458 	char hex[3];
459 	size_t prefix_len = strlen(id_str_prefix);
460 	struct got_packidx_object_id *oid;
461 	int i;
462 
463 	SIMPLEQ_INIT(matched_ids);
464 
465 	if (prefix_len < 2)
466 		return got_error(GOT_ERR_BAD_OBJ_ID_STR);
467 
468 	hex[0] = id_str_prefix[0];
469 	hex[1] = id_str_prefix[1];
470 	hex[2] = '\0';
471 	if (!got_parse_xdigit(&id0, hex))
472 		return got_error(GOT_ERR_BAD_OBJ_ID_STR);
473 
474 	i = betoh32(packidx->hdr.fanout_table[id0 - 1]);
475 	if (i == 0)
476 		return NULL;
477 
478 	oid = &packidx->hdr.sorted_ids[i];
479 	while (i < totobj && oid->sha1[0] == id0) {
480 		char id_str[SHA1_DIGEST_STRING_LENGTH];
481 		struct got_object_qid *qid;
482 		int cmp;
483 
484 		if (!got_sha1_digest_to_str(oid->sha1, id_str, sizeof(id_str)))
485 		        return got_error(GOT_ERR_NO_SPACE);
486 
487 		cmp = strncmp(id_str, id_str_prefix, prefix_len);
488 		if (cmp < 0) {
489 			oid = &packidx->hdr.sorted_ids[++i];
490 			continue;
491 		} else if (cmp > 0)
492 			break;
493 
494 		err = got_object_qid_alloc_partial(&qid);
495 		if (err)
496 			break;
497 		memcpy(qid->id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
498 		SIMPLEQ_INSERT_TAIL(matched_ids, qid, entry);
499 
500 		oid = &packidx->hdr.sorted_ids[++i];
501 	}
502 
503 	if (err)
504 		got_object_id_queue_free(matched_ids);
505 	return err;
506 }
507 
508 const struct got_error *
509 got_pack_stop_privsep_child(struct got_pack *pack)
510 {
511 	const struct got_error *err = NULL;
512 
513 	if (pack->privsep_child == NULL)
514 		return NULL;
515 
516 	err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
517 	if (err)
518 		return err;
519 	err = got_privsep_wait_for_child(pack->privsep_child->pid);
520 	if (close(pack->privsep_child->imsg_fd) != 0 && err == NULL)
521 		err = got_error_from_errno("close");
522 	free(pack->privsep_child);
523 	pack->privsep_child = NULL;
524 	return err;
525 }
526 
527 const struct got_error *
528 got_pack_close(struct got_pack *pack)
529 {
530 	const struct got_error *err = NULL;
531 
532 	err = got_pack_stop_privsep_child(pack);
533 	if (pack->map && munmap(pack->map, pack->filesize) == -1 && !err)
534 		err = got_error_from_errno("munmap");
535 	if (pack->fd != -1 && close(pack->fd) != 0 && err == NULL)
536 		err = got_error_from_errno("close");
537 	pack->fd = -1;
538 	free(pack->path_packfile);
539 	pack->path_packfile = NULL;
540 	pack->filesize = 0;
541 
542 	return err;
543 }
544 
545 static const struct got_error *
546 parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len,
547     struct got_pack *pack, off_t offset)
548 {
549 	uint8_t t = 0;
550 	uint64_t s = 0;
551 	uint8_t sizeN;
552 	size_t mapoff = 0;
553 	int i = 0;
554 
555 	*len = 0;
556 
557 	if (offset >= pack->filesize)
558 		return got_error(GOT_ERR_PACK_OFFSET);
559 
560 	if (pack->map) {
561 		mapoff = (size_t)offset;
562 	} else {
563 		if (lseek(pack->fd, offset, SEEK_SET) == -1)
564 			return got_error_from_errno("lseek");
565 	}
566 
567 	do {
568 		/* We do not support size values which don't fit in 64 bit. */
569 		if (i > 9)
570 			return got_error(GOT_ERR_NO_SPACE);
571 
572 		if (pack->map) {
573 			sizeN = *(pack->map + mapoff);
574 			mapoff += sizeof(sizeN);
575 		} else {
576 			ssize_t n = read(pack->fd, &sizeN, sizeof(sizeN));
577 			if (n < 0)
578 				return got_error_from_errno("read");
579 			if (n != sizeof(sizeN))
580 				return got_error(GOT_ERR_BAD_PACKFILE);
581 		}
582 		*len += sizeof(sizeN);
583 
584 		if (i == 0) {
585 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
586 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
587 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
588 		} else {
589 			size_t shift = 4 + 7 * (i - 1);
590 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
591 		}
592 		i++;
593 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
594 
595 	*type = t;
596 	*size = s;
597 	return NULL;
598 }
599 
600 static const struct got_error *
601 open_plain_object(struct got_object **obj, const char *path_packfile,
602     struct got_object_id *id, uint8_t type, off_t offset, size_t size, int idx)
603 {
604 	*obj = calloc(1, sizeof(**obj));
605 	if (*obj == NULL)
606 		return got_error_from_errno("calloc");
607 
608 	(*obj)->path_packfile = strdup(path_packfile);
609 	if ((*obj)->path_packfile == NULL) {
610 		const struct got_error *err = got_error_from_errno("strdup");
611 		free(*obj);
612 		*obj = NULL;
613 		return err;
614 	}
615 
616 	(*obj)->type = type;
617 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
618 	(*obj)->pack_idx = idx;
619 	(*obj)->hdrlen = 0;
620 	(*obj)->size = size;
621 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
622 	(*obj)->pack_offset = offset;
623 
624 	return NULL;
625 }
626 
627 static const struct got_error *
628 parse_negative_offset(int64_t *offset, size_t *len, struct got_pack *pack,
629     off_t delta_offset)
630 {
631 	int64_t o = 0;
632 	uint8_t offN;
633 	int i = 0;
634 
635 	*offset = 0;
636 	*len = 0;
637 
638 	do {
639 		/* We do not support offset values which don't fit in 64 bit. */
640 		if (i > 8)
641 			return got_error(GOT_ERR_NO_SPACE);
642 
643 		if (pack->map) {
644 			size_t mapoff;
645 			if (delta_offset >= pack->filesize)
646 				return got_error(GOT_ERR_PACK_OFFSET);
647 			mapoff = (size_t)delta_offset + *len;
648 			offN = *(pack->map + mapoff);
649 		} else {
650 			ssize_t n;
651 			n = read(pack->fd, &offN, sizeof(offN));
652 			if (n < 0)
653 				return got_error_from_errno("read");
654 			if (n != sizeof(offN))
655 				return got_error(GOT_ERR_BAD_PACKFILE);
656 		}
657 		*len += sizeof(offN);
658 
659 		if (i == 0)
660 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
661 		else {
662 			o++;
663 			o <<= 7;
664 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
665 		}
666 		i++;
667 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
668 
669 	*offset = o;
670 	return NULL;
671 }
672 
673 static const struct got_error *
674 parse_offset_delta(off_t *base_offset, size_t *len, struct got_pack *pack,
675     off_t offset, int tslen)
676 {
677 	const struct got_error *err;
678 	int64_t negoffset;
679 	size_t negofflen;
680 
681 	*len = 0;
682 
683 	err = parse_negative_offset(&negoffset, &negofflen, pack,
684 	    offset + tslen);
685 	if (err)
686 		return err;
687 
688 	/* Compute the base object's offset (must be in the same pack file). */
689 	*base_offset = (offset - negoffset);
690 	if (*base_offset <= 0)
691 		return got_error(GOT_ERR_BAD_PACKFILE);
692 
693 	*len = negofflen;
694 	return NULL;
695 }
696 
697 static const struct got_error *
698 resolve_delta_chain(struct got_delta_chain *, struct got_packidx *,
699     struct got_pack *, off_t, size_t, int, size_t, unsigned int);
700 
701 static const struct got_error *
702 add_delta(struct got_delta_chain *deltas, off_t delta_offset, size_t tslen,
703     int delta_type, size_t delta_size, size_t delta_data_offset,
704     uint8_t *delta_buf, size_t delta_len)
705 {
706 	struct got_delta *delta;
707 
708 	delta = got_delta_open(delta_offset, tslen, delta_type, delta_size,
709 	    delta_data_offset, delta_buf,
710 	    delta_len);
711 	if (delta == NULL)
712 		return got_error_from_errno("got_delta_open");
713 	/* delta is freed in got_object_close() */
714 	deltas->nentries++;
715 	SIMPLEQ_INSERT_HEAD(&deltas->entries, delta, entry);
716 	return NULL;
717 }
718 
719 static const struct got_error *
720 resolve_offset_delta(struct got_delta_chain *deltas,
721     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
722     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
723 
724 {
725 	const struct got_error *err;
726 	off_t base_offset;
727 	uint8_t base_type;
728 	uint64_t base_size;
729 	size_t base_tslen;
730 	off_t delta_data_offset;
731 	uint8_t *delta_buf;
732 	size_t delta_len, consumed;
733 
734 	err = parse_offset_delta(&base_offset, &consumed, pack,
735 	    delta_offset, tslen);
736 	if (err)
737 		return err;
738 
739 	delta_data_offset = delta_offset + tslen + consumed;
740 	if (delta_data_offset >= pack->filesize)
741 		return got_error(GOT_ERR_PACK_OFFSET);
742 
743 	if (pack->map == NULL) {
744 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
745 		if (delta_data_offset == -1)
746 			return got_error_from_errno("lseek");
747 	}
748 
749 	if (pack->map) {
750 		size_t mapoff = (size_t)delta_data_offset;
751 		err = got_inflate_to_mem_mmap(&delta_buf, &delta_len, pack->map,
752 		    mapoff, pack->filesize - mapoff);
753 		if (err)
754 			return err;
755 	} else {
756 
757 		err = got_inflate_to_mem_fd(&delta_buf, &delta_len, pack->fd);
758 		if (err)
759 			return err;
760 	}
761 
762 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
763 	    delta_data_offset, delta_buf, delta_len);
764 	if (err)
765 		return err;
766 
767 	/* An offset delta must be in the same packfile. */
768 	if (base_offset >= pack->filesize)
769 		return got_error(GOT_ERR_PACK_OFFSET);
770 
771 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
772 	    pack, base_offset);
773 	if (err)
774 		return err;
775 
776 	return resolve_delta_chain(deltas, packidx, pack, base_offset,
777 	    base_tslen, base_type, base_size, recursion - 1);
778 }
779 
780 static const struct got_error *
781 resolve_ref_delta(struct got_delta_chain *deltas, struct got_packidx *packidx,
782     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
783     size_t delta_size, unsigned int recursion)
784 {
785 	const struct got_error *err;
786 	struct got_object_id id;
787 	int idx;
788 	off_t base_offset;
789 	uint8_t base_type;
790 	uint64_t base_size;
791 	size_t base_tslen;
792 	off_t delta_data_offset;
793 	uint8_t *delta_buf;
794 	size_t delta_len;
795 
796 	if (delta_offset >= pack->filesize)
797 		return got_error(GOT_ERR_PACK_OFFSET);
798 	delta_data_offset = delta_offset + tslen;
799 	if (delta_data_offset >= pack->filesize)
800 		return got_error(GOT_ERR_PACK_OFFSET);
801 
802 	if (pack->map == NULL) {
803 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
804 		if (delta_data_offset == -1)
805 			return got_error_from_errno("lseek");
806 	}
807 
808 	if (pack->map) {
809 		size_t mapoff = (size_t)delta_data_offset;
810 		memcpy(&id, pack->map + mapoff, sizeof(id));
811 		mapoff += sizeof(id);
812 		err = got_inflate_to_mem_mmap(&delta_buf, &delta_len, pack->map,
813 		    mapoff, pack->filesize - mapoff);
814 		if (err)
815 			return err;
816 	} else {
817 		ssize_t n = read(pack->fd, &id, sizeof(id));
818 		if (n < 0)
819 			return got_error_from_errno("read");
820 		if (n != sizeof(id))
821 			return got_error(GOT_ERR_BAD_PACKFILE);
822 		err = got_inflate_to_mem_fd(&delta_buf, &delta_len, pack->fd);
823 		if (err)
824 			return err;
825 	}
826 
827 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
828 	    delta_data_offset, delta_buf, delta_len);
829 	if (err)
830 		return err;
831 
832 	/* Delta base must be in the same pack file. */
833 	idx = got_packidx_get_object_idx(packidx, &id);
834 	if (idx == -1)
835 		return got_error(GOT_ERR_BAD_PACKFILE);
836 
837 	base_offset = get_object_offset(packidx, idx);
838 	if (base_offset == (uint64_t)-1)
839 		return got_error(GOT_ERR_BAD_PACKIDX);
840 
841 	if (base_offset >= pack->filesize)
842 		return got_error(GOT_ERR_PACK_OFFSET);
843 
844 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
845 	    pack, base_offset);
846 	if (err)
847 		return err;
848 
849 	return resolve_delta_chain(deltas, packidx, pack, base_offset,
850 	    base_tslen, base_type, base_size, recursion - 1);
851 }
852 
853 static const struct got_error *
854 resolve_delta_chain(struct got_delta_chain *deltas, struct got_packidx *packidx,
855     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
856     size_t delta_size, unsigned int recursion)
857 {
858 	const struct got_error *err = NULL;
859 
860 	if (--recursion == 0)
861 		return got_error(GOT_ERR_RECURSION);
862 
863 	switch (delta_type) {
864 	case GOT_OBJ_TYPE_COMMIT:
865 	case GOT_OBJ_TYPE_TREE:
866 	case GOT_OBJ_TYPE_BLOB:
867 	case GOT_OBJ_TYPE_TAG:
868 		/* Plain types are the final delta base. Recursion ends. */
869 		err = add_delta(deltas, delta_offset, tslen, delta_type,
870 		    delta_size, 0, NULL, 0);
871 		break;
872 	case GOT_OBJ_TYPE_OFFSET_DELTA:
873 		err = resolve_offset_delta(deltas, packidx, pack,
874 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
875 		break;
876 	case GOT_OBJ_TYPE_REF_DELTA:
877 		err = resolve_ref_delta(deltas, packidx, pack,
878 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
879 		break;
880 	default:
881 		return got_error(GOT_ERR_OBJ_TYPE);
882 	}
883 
884 	return err;
885 }
886 
887 static const struct got_error *
888 open_delta_object(struct got_object **obj, struct got_packidx *packidx,
889     struct got_pack *pack, struct got_object_id *id, off_t offset,
890     size_t tslen, int delta_type, size_t delta_size, int idx)
891 {
892 	const struct got_error *err = NULL;
893 	int resolved_type;
894 
895 	*obj = calloc(1, sizeof(**obj));
896 	if (*obj == NULL)
897 		return got_error_from_errno("calloc");
898 
899 	(*obj)->flags = 0;
900 	(*obj)->hdrlen = 0;
901 	(*obj)->size = 0; /* Not known because deltas aren't applied yet. */
902 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
903 	(*obj)->pack_offset = offset + tslen;
904 
905 	SIMPLEQ_INIT(&(*obj)->deltas.entries);
906 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
907 
908 	(*obj)->path_packfile = strdup(pack->path_packfile);
909 	if ((*obj)->path_packfile == NULL) {
910 		err = got_error_from_errno("strdup");
911 		goto done;
912 	}
913 	(*obj)->flags |= GOT_OBJ_FLAG_PACKED;
914 	(*obj)->pack_idx = idx;
915 
916 	err = resolve_delta_chain(&(*obj)->deltas, packidx, pack, offset,
917 	    tslen, delta_type, delta_size, GOT_DELTA_CHAIN_RECURSION_MAX);
918 	if (err)
919 		goto done;
920 
921 	err = got_delta_chain_get_base_type(&resolved_type, &(*obj)->deltas);
922 	if (err)
923 		goto done;
924 	(*obj)->type = resolved_type;
925 done:
926 	if (err) {
927 		got_object_close(*obj);
928 		*obj = NULL;
929 	}
930 	return err;
931 }
932 
933 const struct got_error *
934 got_packfile_open_object(struct got_object **obj, struct got_pack *pack,
935     struct got_packidx *packidx, int idx, struct got_object_id *id)
936 {
937 	const struct got_error *err = NULL;
938 	off_t offset;
939 	uint8_t type;
940 	uint64_t size;
941 	size_t tslen;
942 
943 	*obj = NULL;
944 
945 	offset = get_object_offset(packidx, idx);
946 	if (offset == (uint64_t)-1)
947 		return got_error(GOT_ERR_BAD_PACKIDX);
948 
949 	err = parse_object_type_and_size(&type, &size, &tslen, pack, offset);
950 	if (err)
951 		return err;
952 
953 	switch (type) {
954 	case GOT_OBJ_TYPE_COMMIT:
955 	case GOT_OBJ_TYPE_TREE:
956 	case GOT_OBJ_TYPE_BLOB:
957 	case GOT_OBJ_TYPE_TAG:
958 		err = open_plain_object(obj, pack->path_packfile, id, type,
959 		    offset + tslen, size, idx);
960 		break;
961 	case GOT_OBJ_TYPE_OFFSET_DELTA:
962 	case GOT_OBJ_TYPE_REF_DELTA:
963 		err = open_delta_object(obj, packidx, pack, id, offset,
964 		    tslen, type, size, idx);
965 		break;
966 	default:
967 		err = got_error(GOT_ERR_OBJ_TYPE);
968 		break;
969 	}
970 
971 	return err;
972 }
973 
974 static const struct got_error *
975 get_delta_chain_max_size(uint64_t *max_size, struct got_delta_chain *deltas)
976 {
977 	struct got_delta *delta;
978 	uint64_t base_size = 0, result_size = 0;
979 
980 	*max_size = 0;
981 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
982 		/* Plain object types are the delta base. */
983 		if (delta->type != GOT_OBJ_TYPE_COMMIT &&
984 		    delta->type != GOT_OBJ_TYPE_TREE &&
985 		    delta->type != GOT_OBJ_TYPE_BLOB &&
986 		    delta->type != GOT_OBJ_TYPE_TAG) {
987 			const struct got_error *err;
988 			err = got_delta_get_sizes(&base_size, &result_size,
989 			    delta->delta_buf, delta->delta_len);
990 			if (err)
991 				return err;
992 		} else
993 			base_size = delta->size;
994 		if (base_size > *max_size)
995 			*max_size = base_size;
996 		if (result_size > *max_size)
997 			*max_size = result_size;
998 	}
999 
1000 	return NULL;
1001 }
1002 
1003 const struct got_error *
1004 got_pack_get_max_delta_object_size(uint64_t *size, struct got_object *obj)
1005 {
1006 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0)
1007 		return got_error(GOT_ERR_OBJ_TYPE);
1008 
1009 	return get_delta_chain_max_size(size, &obj->deltas);
1010 }
1011 
1012 static const struct got_error *
1013 dump_delta_chain_to_file(size_t *result_size, struct got_delta_chain *deltas,
1014     struct got_pack *pack, FILE *outfile, FILE *base_file, FILE *accum_file)
1015 {
1016 	const struct got_error *err = NULL;
1017 	struct got_delta *delta;
1018 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1019 	size_t base_bufsz = 0, accum_size = 0;
1020 	uint64_t max_size;
1021 	int n = 0;
1022 
1023 	*result_size = 0;
1024 
1025 	if (SIMPLEQ_EMPTY(&deltas->entries))
1026 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1027 
1028 	/* We process small enough files entirely in memory for speed. */
1029 	err = get_delta_chain_max_size(&max_size, deltas);
1030 	if (err)
1031 		return err;
1032 	if (max_size < GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
1033 		accum_buf = malloc(max_size);
1034 		if (accum_buf == NULL)
1035 			return got_error_from_errno("malloc");
1036 		base_file = NULL;
1037 		accum_file = NULL;
1038 	}
1039 
1040 	/* Deltas are ordered in ascending order. */
1041 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1042 		if (n == 0) {
1043 			size_t mapoff;
1044 			off_t delta_data_offset;
1045 
1046 			/* Plain object types are the delta base. */
1047 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1048 			    delta->type != GOT_OBJ_TYPE_TREE &&
1049 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1050 			    delta->type != GOT_OBJ_TYPE_TAG) {
1051 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1052 				goto done;
1053 			}
1054 
1055 			delta_data_offset = delta->offset + delta->tslen;
1056 			if (delta_data_offset >= pack->filesize) {
1057 				err = got_error(GOT_ERR_PACK_OFFSET);
1058 				goto done;
1059 			}
1060 			if (pack->map == NULL) {
1061 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1062 				    == -1) {
1063 					err = got_error_from_errno("lseek");
1064 					goto done;
1065 				}
1066 			}
1067 			if (base_file) {
1068 				if (pack->map) {
1069 					mapoff = (size_t)delta_data_offset;
1070 					err = got_inflate_to_file_mmap(
1071 					    &base_bufsz, pack->map, mapoff,
1072 					    pack->filesize - mapoff, base_file);
1073 				} else
1074 					err = got_inflate_to_file_fd(
1075 					    &base_bufsz, pack->fd, base_file);
1076 			} else {
1077 				if (pack->map) {
1078 					mapoff = (size_t)delta_data_offset;
1079 					err = got_inflate_to_mem_mmap(&base_buf,
1080 					    &base_bufsz, pack->map, mapoff,
1081 					    pack->filesize - mapoff);
1082 				} else
1083 					err = got_inflate_to_mem_fd(&base_buf,
1084 					    &base_bufsz, pack->fd);
1085 			}
1086 			if (err)
1087 				goto done;
1088 			n++;
1089 			if (base_file)
1090 				rewind(base_file);
1091 			continue;
1092 		}
1093 
1094 		if (base_buf) {
1095 			err = got_delta_apply_in_mem(base_buf, base_bufsz,
1096 			    delta->delta_buf, delta->delta_len, accum_buf,
1097 			    &accum_size, max_size);
1098 			n++;
1099 		} else {
1100 			err = got_delta_apply(base_file, delta->delta_buf,
1101 			    delta->delta_len,
1102 			    /* Final delta application writes to output file. */
1103 			    ++n < deltas->nentries ? accum_file : outfile,
1104 			    &accum_size);
1105 		}
1106 		if (err)
1107 			goto done;
1108 
1109 		if (n < deltas->nentries) {
1110 			/* Accumulated delta becomes the new base. */
1111 			if (base_buf) {
1112 				uint8_t *tmp = accum_buf;
1113 				/*
1114 				 * Base buffer switches roles with accumulation
1115 				 * buffer. Ensure it can hold the largest
1116 				 * result in the delta chain. The initial
1117 				 * allocation might have been smaller.
1118 				 */
1119 				if (base_bufsz < max_size) {
1120 					uint8_t *p;
1121 					p = reallocarray(base_buf, 1, max_size);
1122 					if (p == NULL) {
1123 						err = got_error_from_errno(
1124 						    "reallocarray");
1125 						goto done;
1126 					}
1127 					base_buf = p;
1128 					base_bufsz = max_size;
1129 				}
1130 				accum_buf = base_buf;
1131 				base_buf = tmp;
1132 			} else {
1133 				FILE *tmp = accum_file;
1134 				accum_file = base_file;
1135 				base_file = tmp;
1136 				rewind(base_file);
1137 				rewind(accum_file);
1138 			}
1139 		}
1140 	}
1141 
1142 done:
1143 	free(base_buf);
1144 	if (accum_buf) {
1145 		size_t len = fwrite(accum_buf, 1, accum_size, outfile);
1146 		free(accum_buf);
1147 		if (len != accum_size)
1148 			err = got_ferror(outfile, GOT_ERR_IO);
1149 	}
1150 	rewind(outfile);
1151 	if (err == NULL)
1152 		*result_size = accum_size;
1153 	return err;
1154 }
1155 
1156 static const struct got_error *
1157 dump_delta_chain_to_mem(uint8_t **outbuf, size_t *outlen,
1158     struct got_delta_chain *deltas, struct got_pack *pack)
1159 {
1160 	const struct got_error *err = NULL;
1161 	struct got_delta *delta;
1162 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1163 	size_t base_bufsz = 0, accum_size = 0;
1164 	uint64_t max_size;
1165 	int n = 0;
1166 
1167 	*outbuf = NULL;
1168 	*outlen = 0;
1169 
1170 	if (SIMPLEQ_EMPTY(&deltas->entries))
1171 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1172 
1173 	err = get_delta_chain_max_size(&max_size, deltas);
1174 	if (err)
1175 		return err;
1176 	accum_buf = malloc(max_size);
1177 	if (accum_buf == NULL)
1178 		return got_error_from_errno("malloc");
1179 
1180 	/* Deltas are ordered in ascending order. */
1181 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1182 		if (n == 0) {
1183 			size_t delta_data_offset;
1184 
1185 			/* Plain object types are the delta base. */
1186 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1187 			    delta->type != GOT_OBJ_TYPE_TREE &&
1188 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1189 			    delta->type != GOT_OBJ_TYPE_TAG) {
1190 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1191 				goto done;
1192 			}
1193 
1194 			delta_data_offset = delta->offset + delta->tslen;
1195 			if (delta_data_offset >= pack->filesize) {
1196 				err = got_error(GOT_ERR_PACK_OFFSET);
1197 				goto done;
1198 			}
1199 			if (pack->map) {
1200 				size_t mapoff = (size_t)delta_data_offset;
1201 				err = got_inflate_to_mem_mmap(&base_buf,
1202 				    &base_bufsz, pack->map, mapoff,
1203 				    pack->filesize - mapoff);
1204 			} else {
1205 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1206 				    == -1) {
1207 					err = got_error_from_errno("lseek");
1208 					goto done;
1209 				}
1210 				err = got_inflate_to_mem_fd(&base_buf,
1211 				    &base_bufsz, pack->fd);
1212 			}
1213 			if (err)
1214 				goto done;
1215 			n++;
1216 			continue;
1217 		}
1218 
1219 		err = got_delta_apply_in_mem(base_buf, base_bufsz,
1220 		    delta->delta_buf, delta->delta_len, accum_buf,
1221 		    &accum_size, max_size);
1222 		n++;
1223 		if (err)
1224 			goto done;
1225 
1226 		if (n < deltas->nentries) {
1227 			/* Accumulated delta becomes the new base. */
1228 			uint8_t *tmp = accum_buf;
1229 			/*
1230 			 * Base buffer switches roles with accumulation buffer.
1231 			 * Ensure it can hold the largest result in the delta
1232 			 * chain. Initial allocation might have been smaller.
1233 			 */
1234 			if (base_bufsz < max_size) {
1235 				uint8_t *p;
1236 				p = reallocarray(base_buf, 1, max_size);
1237 				if (p == NULL) {
1238 					err = got_error_from_errno(
1239 					    "reallocarray");
1240 					goto done;
1241 				}
1242 				base_buf = p;
1243 				base_bufsz = max_size;
1244 			}
1245 			accum_buf = base_buf;
1246 			base_buf = tmp;
1247 		}
1248 	}
1249 
1250 done:
1251 	free(base_buf);
1252 	if (err) {
1253 		free(accum_buf);
1254 		*outbuf = NULL;
1255 		*outlen = 0;
1256 	} else {
1257 		*outbuf = accum_buf;
1258 		*outlen = accum_size;
1259 	}
1260 	return err;
1261 }
1262 
1263 const struct got_error *
1264 got_packfile_extract_object(struct got_pack *pack, struct got_object *obj,
1265     FILE *outfile, FILE *base_file, FILE *accum_file)
1266 {
1267 	const struct got_error *err = NULL;
1268 
1269 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1270 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1271 
1272 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1273 		if (obj->pack_offset >= pack->filesize)
1274 			return got_error(GOT_ERR_PACK_OFFSET);
1275 
1276 		if (pack->map) {
1277 			size_t mapoff = (size_t)obj->pack_offset;
1278 			err = got_inflate_to_file_mmap(&obj->size, pack->map,
1279 			    mapoff, pack->filesize - mapoff, outfile);
1280 		} else {
1281 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1282 				return got_error_from_errno("lseek");
1283 			err = got_inflate_to_file_fd(&obj->size, pack->fd,
1284 			    outfile);
1285 		}
1286 	} else
1287 		err = dump_delta_chain_to_file(&obj->size, &obj->deltas, pack,
1288 		    outfile, base_file, accum_file);
1289 
1290 	return err;
1291 }
1292 
1293 const struct got_error *
1294 got_packfile_extract_object_to_mem(uint8_t **buf, size_t *len,
1295     struct got_object *obj, struct got_pack *pack)
1296 {
1297 	const struct got_error *err = NULL;
1298 
1299 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1300 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1301 
1302 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1303 		if (obj->pack_offset >= pack->filesize)
1304 			return got_error(GOT_ERR_PACK_OFFSET);
1305 		if (pack->map) {
1306 			size_t mapoff = (size_t)obj->pack_offset;
1307 			err = got_inflate_to_mem_mmap(buf, len, pack->map,
1308 			    mapoff, pack->filesize - mapoff);
1309 		} else {
1310 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1311 				return got_error_from_errno("lseek");
1312 			err = got_inflate_to_mem_fd(buf, len, pack->fd);
1313 		}
1314 	} else
1315 		err = dump_delta_chain_to_mem(buf, len, &obj->deltas, pack);
1316 
1317 	return err;
1318 }