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Date:: Sat Jun 29 21:28:23 2019 UTC
Message:: call got_object_id_queue_free() instead of implementing it inline
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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 		else if (n != sizeof(*h->magic)) {
101 			err = got_error(GOT_ERR_BAD_PACKIDX);
102 			goto done;
103 		}
104 	}
105 	if (betoh32(*h->magic) != GOT_PACKIDX_V2_MAGIC) {
106 		err = got_error(GOT_ERR_BAD_PACKIDX);
107 		goto done;
108 	}
109 	offset += sizeof(*h->magic);
110 	remain -= sizeof(*h->magic);
111 
112 	if (verify)
113 		SHA1Update(&ctx, (uint8_t *)h->magic, sizeof(*h->magic));
114 
115 	if (remain < sizeof(*h->version)) {
116 		err = got_error(GOT_ERR_BAD_PACKIDX);
117 		goto done;
118 	}
119 	if (p->map)
120 		h->version = (uint32_t *)(p->map + offset);
121 	else {
122 		h->version = malloc(sizeof(*h->version));
123 		if (h->version == NULL) {
124 			err = got_error_from_errno("malloc");
125 			goto done;
126 		}
127 		n = read(p->fd, h->version, sizeof(*h->version));
128 		if (n < 0)
129 			err = got_error_from_errno("read");
130 		else if (n != sizeof(*h->version)) {
131 			err = got_error(GOT_ERR_BAD_PACKIDX);
132 			goto done;
133 		}
134 	}
135 	if (betoh32(*h->version) != GOT_PACKIDX_VERSION) {
136 		err = got_error(GOT_ERR_BAD_PACKIDX);
137 		goto done;
138 	}
139 	offset += sizeof(*h->version);
140 	remain -= sizeof(*h->version);
141 
142 	if (verify)
143 		SHA1Update(&ctx, (uint8_t *)h->version, sizeof(*h->version));
144 
145 	len_fanout =
146 	    sizeof(*h->fanout_table) * GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS;
147 	if (remain < len_fanout) {
148 		err = got_error(GOT_ERR_BAD_PACKIDX);
149 		goto done;
150 	}
151 	if (p->map)
152 		h->fanout_table = (uint32_t *)(p->map + offset);
153 	else {
154 		h->fanout_table = malloc(len_fanout);
155 		if (h->fanout_table == NULL) {
156 			err = got_error_from_errno("malloc");
157 			goto done;
158 		}
159 		n = read(p->fd, h->fanout_table, len_fanout);
160 		if (n < 0)
161 			err = got_error_from_errno("read");
162 		else if (n != len_fanout) {
163 			err = got_error(GOT_ERR_BAD_PACKIDX);
164 			goto done;
165 		}
166 	}
167 	err = verify_fanout_table(h->fanout_table);
168 	if (err)
169 		goto done;
170 	if (verify)
171 		SHA1Update(&ctx, (uint8_t *)h->fanout_table, len_fanout);
172 	offset += len_fanout;
173 	remain -= len_fanout;
174 
175 	nobj = betoh32(h->fanout_table[0xff]);
176 	len_ids = nobj * sizeof(*h->sorted_ids);
177 	if (len_ids <= nobj || len_ids > remain) {
178 		err = got_error(GOT_ERR_BAD_PACKIDX);
179 		goto done;
180 	}
181 	if (p->map)
182 		h->sorted_ids =
183 		    (struct got_packidx_object_id *)((uint8_t*)(p->map + offset));
184 	else {
185 		h->sorted_ids = malloc(len_ids);
186 		if (h->sorted_ids == NULL) {
187 			err = got_error(GOT_ERR_BAD_PACKIDX);
188 			goto done;
189 		}
190 		n = read(p->fd, h->sorted_ids, len_ids);
191 		if (n < 0)
192 			err = got_error_from_errno("read");
193 		else if (n != len_ids) {
194 			err = got_error(GOT_ERR_BAD_PACKIDX);
195 			goto done;
196 		}
197 	}
198 	if (verify)
199 		SHA1Update(&ctx, (uint8_t *)h->sorted_ids, len_ids);
200 	offset += len_ids;
201 	remain -= len_ids;
202 
203 	if (remain < nobj * sizeof(*h->crc32)) {
204 		err = got_error(GOT_ERR_BAD_PACKIDX);
205 		goto done;
206 	}
207 	if (p->map)
208 		h->crc32 = (uint32_t *)((uint8_t*)(p->map + offset));
209 	else {
210 		h->crc32 = malloc(nobj * sizeof(*h->crc32));
211 		if (h->crc32 == NULL) {
212 			err = got_error_from_errno("malloc");
213 			goto done;
214 		}
215 		n = read(p->fd, h->crc32, nobj * sizeof(*h->crc32));
216 		if (n < 0)
217 			err = got_error_from_errno("read");
218 		else if (n != nobj * sizeof(*h->crc32)) {
219 			err = got_error(GOT_ERR_BAD_PACKIDX);
220 			goto done;
221 		}
222 	}
223 	if (verify)
224 		SHA1Update(&ctx, (uint8_t *)h->crc32, nobj * sizeof(*h->crc32));
225 	remain -= nobj * sizeof(*h->crc32);
226 	offset += nobj * sizeof(*h->crc32);
227 
228 	if (remain < nobj * sizeof(*h->offsets)) {
229 		err = got_error(GOT_ERR_BAD_PACKIDX);
230 		goto done;
231 	}
232 	if (p->map)
233 		h->offsets = (uint32_t *)((uint8_t*)(p->map + offset));
234 	else {
235 		h->offsets = malloc(nobj * sizeof(*h->offsets));
236 		if (h->offsets == NULL) {
237 			err = got_error_from_errno("malloc");
238 			goto done;
239 		}
240 		n = read(p->fd, h->offsets, nobj * sizeof(*h->offsets));
241 		if (n < 0)
242 			err = got_error_from_errno("read");
243 		else if (n != nobj * sizeof(*h->offsets)) {
244 			err = got_error(GOT_ERR_BAD_PACKIDX);
245 			goto done;
246 		}
247 	}
248 	if (verify)
249 		SHA1Update(&ctx, (uint8_t *)h->offsets,
250 		    nobj * sizeof(*h->offsets));
251 	remain -= nobj * sizeof(*h->offsets);
252 	offset += nobj * sizeof(*h->offsets);
253 
254 	/* Large file offsets are contained only in files > 2GB. */
255 	if (p->len <= 0x80000000)
256 		goto checksum;
257 
258 	if (remain < nobj * sizeof(*h->large_offsets)) {
259 		err = got_error(GOT_ERR_BAD_PACKIDX);
260 		goto done;
261 	}
262 	if (p->map)
263 		h->large_offsets = (uint64_t *)((uint8_t*)(p->map + offset));
264 	else {
265 		h->offsets = malloc(nobj * sizeof(*h->large_offsets));
266 		if (h->offsets == NULL) {
267 			err = got_error_from_errno("malloc");
268 			goto done;
269 		}
270 		n = read(p->fd, h->large_offsets,
271 		    nobj * sizeof(*h->large_offsets));
272 		if (n < 0)
273 			err = got_error_from_errno("read");
274 		else if (n != nobj * sizeof(*h->large_offsets)) {
275 			err = got_error(GOT_ERR_BAD_PACKIDX);
276 			goto done;
277 		}
278 	}
279 	if (verify)
280 		SHA1Update(&ctx, (uint8_t*)h->large_offsets,
281 		    nobj * sizeof(*h->large_offsets));
282 	remain -= nobj * sizeof(*h->large_offsets);
283 	offset += nobj * sizeof(*h->large_offsets);
284 
285 checksum:
286 	if (remain < sizeof(*h->trailer)) {
287 		err = got_error(GOT_ERR_BAD_PACKIDX);
288 		goto done;
289 	}
290 	if (p->map)
291 		h->trailer =
292 		    (struct got_packidx_trailer *)((uint8_t*)(p->map + offset));
293 	else {
294 		h->trailer = malloc(sizeof(*h->trailer));
295 		if (h->trailer == NULL) {
296 			err = got_error_from_errno("malloc");
297 			goto done;
298 		}
299 		n = read(p->fd, h->trailer, sizeof(*h->trailer));
300 		if (n < 0)
301 			err = got_error_from_errno("read");
302 		else if (n != sizeof(*h->trailer)) {
303 			err = got_error(GOT_ERR_BAD_PACKIDX);
304 			goto done;
305 		}
306 	}
307 	if (verify) {
308 		SHA1Update(&ctx, h->trailer->packfile_sha1, SHA1_DIGEST_LENGTH);
309 		SHA1Final(sha1, &ctx);
310 		if (memcmp(h->trailer->packidx_sha1, sha1,
311 		    SHA1_DIGEST_LENGTH) != 0)
312 			err = got_error(GOT_ERR_PACKIDX_CSUM);
313 	}
314 done:
315 	return err;
316 }
317 
318 const struct got_error *
319 got_packidx_open(struct got_packidx **packidx, const char *path, int verify)
320 {
321 	const struct got_error *err = NULL;
322 	struct got_packidx *p;
323 	struct stat sb;
324 
325 	*packidx = NULL;
326 
327 	p = calloc(1, sizeof(*p));
328 	if (p == NULL)
329 		return got_error_from_errno("calloc");
330 
331 	p->fd = open(path, O_RDONLY | O_NOFOLLOW);
332 	if (p->fd == -1)
333 		return got_error_from_errno2("open", path);
334 
335 	if (fstat(p->fd, &sb) != 0) {
336 		err = got_error_from_errno2("fstat", path);
337 		close(p->fd);
338 		free(p);
339 		return err;
340 	}
341 	p->len = sb.st_size;
342 	if (p->len < sizeof(p->hdr)) {
343 		err = got_error(GOT_ERR_BAD_PACKIDX);
344 		close(p->fd);
345 		free(p);
346 		return err;
347 	}
348 
349 	p->path_packidx = strdup(path);
350 	if (p->path_packidx == NULL) {
351 		err = got_error_from_errno("strdup");
352 		goto done;
353 	}
354 
355 #ifndef GOT_PACK_NO_MMAP
356 	p->map = mmap(NULL, p->len, PROT_READ, MAP_PRIVATE, p->fd, 0);
357 	if (p->map == MAP_FAILED) {
358 		if (errno != ENOMEM) {
359 			err = got_error_from_errno("mmap");
360 			goto done;
361 		}
362 		p->map = NULL; /* fall back to read(2) */
363 	}
364 #endif
365 
366 	err = got_packidx_init_hdr(p, verify);
367 done:
368 	if (err)
369 		got_packidx_close(p);
370 	else
371 		*packidx = p;
372 
373 	return err;
374 }
375 
376 const struct got_error *
377 got_packidx_close(struct got_packidx *packidx)
378 {
379 	const struct got_error *err = NULL;
380 
381 	free(packidx->path_packidx);
382 	if (packidx->map) {
383 		if (munmap(packidx->map, packidx->len) == -1)
384 			err = got_error_from_errno("munmap");
385 	} else {
386 		free(packidx->hdr.magic);
387 		free(packidx->hdr.version);
388 		free(packidx->hdr.fanout_table);
389 		free(packidx->hdr.sorted_ids);
390 		free(packidx->hdr.crc32);
391 		free(packidx->hdr.offsets);
392 		free(packidx->hdr.large_offsets);
393 		free(packidx->hdr.trailer);
394 	}
395 	if (close(packidx->fd) != 0 && err == NULL)
396 		err = got_error_from_errno("close");
397 	free(packidx);
398 
399 	return err;
400 }
401 
402 static off_t
403 get_object_offset(struct got_packidx *packidx, int idx)
404 {
405 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
406 	uint32_t offset = betoh32(packidx->hdr.offsets[idx]);
407 	if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
408 		uint64_t loffset;
409 		idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
410 		if (idx < 0 || idx > totobj ||
411 		    packidx->hdr.large_offsets == NULL)
412 			return -1;
413 		loffset = betoh64(packidx->hdr.large_offsets[idx]);
414 		return (loffset > INT64_MAX ? -1 : (off_t)loffset);
415 	}
416 	return (off_t)(offset & GOT_PACKIDX_OFFSET_VAL_MASK);
417 }
418 
419 int
420 got_packidx_get_object_idx(struct got_packidx *packidx, struct got_object_id *id)
421 {
422 	u_int8_t id0 = id->sha1[0];
423 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
424 	int left = 0, right = totobj - 1;
425 
426 	if (id0 > 0)
427 		left = betoh32(packidx->hdr.fanout_table[id0 - 1]);
428 
429 	while (left <= right) {
430 		struct got_packidx_object_id *oid;
431 		int i, cmp;
432 
433 		i = ((left + right) / 2);
434 		oid = &packidx->hdr.sorted_ids[i];
435 		cmp = memcmp(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
436 		if (cmp == 0)
437 			return i;
438 		else if (cmp > 0)
439 			left = i + 1;
440 		else if (cmp < 0)
441 			right = i - 1;
442 	}
443 
444 	return -1;
445 }
446 
447 const struct got_error *
448 got_packidx_match_id_str_prefix(struct got_object_id_queue *matched_ids,
449     struct got_packidx *packidx, const char *id_str_prefix)
450 {
451 	const struct got_error *err = NULL;
452 	u_int8_t id0;
453 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
454 	char hex[3];
455 	size_t prefix_len = strlen(id_str_prefix);
456 	struct got_packidx_object_id *oid;
457 	int i;
458 
459 	SIMPLEQ_INIT(matched_ids);
460 
461 	if (prefix_len < 2)
462 		return got_error(GOT_ERR_BAD_OBJ_ID_STR);
463 
464 	hex[0] = id_str_prefix[0];
465 	hex[1] = id_str_prefix[1];
466 	hex[2] = '\0';
467 	if (!got_parse_xdigit(&id0, hex))
468 		return got_error(GOT_ERR_BAD_OBJ_ID_STR);
469 
470 	i = betoh32(packidx->hdr.fanout_table[id0 - 1]);
471 	if (i == 0)
472 		return NULL;
473 
474 	oid = &packidx->hdr.sorted_ids[i];
475 	while (i < totobj && oid->sha1[0] == id0) {
476 		char id_str[SHA1_DIGEST_STRING_LENGTH];
477 		struct got_object_qid *qid;
478 		int cmp;
479 
480 		if (!got_sha1_digest_to_str(oid->sha1, id_str, sizeof(id_str)))
481 		        return got_error(GOT_ERR_NO_SPACE);
482 
483 		cmp = strncmp(id_str, id_str_prefix, prefix_len);
484 		if (cmp < 0) {
485 			oid = &packidx->hdr.sorted_ids[++i];
486 			continue;
487 		} else if (cmp > 0)
488 			break;
489 
490 		err = got_object_qid_alloc_partial(&qid);
491 		if (err)
492 			break;
493 		memcpy(qid->id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
494 		SIMPLEQ_INSERT_TAIL(matched_ids, qid, entry);
495 
496 		oid = &packidx->hdr.sorted_ids[++i];
497 	}
498 
499 	if (err)
500 		got_object_id_queue_free(matched_ids);
501 	return err;
502 }
503 
504 const struct got_error *
505 got_pack_stop_privsep_child(struct got_pack *pack)
506 {
507 	const struct got_error *err = NULL;
508 
509 	if (pack->privsep_child == NULL)
510 		return NULL;
511 
512 	err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
513 	if (err)
514 		return err;
515 	err = got_privsep_wait_for_child(pack->privsep_child->pid);
516 	if (close(pack->privsep_child->imsg_fd) != 0 && err == NULL)
517 		err = got_error_from_errno("close");
518 	free(pack->privsep_child);
519 	pack->privsep_child = NULL;
520 	return err;
521 }
522 
523 const struct got_error *
524 got_pack_close(struct got_pack *pack)
525 {
526 	const struct got_error *err = NULL;
527 
528 	err = got_pack_stop_privsep_child(pack);
529 	if (pack->map && munmap(pack->map, pack->filesize) == -1 && !err)
530 		err = got_error_from_errno("munmap");
531 	if (pack->fd != -1 && close(pack->fd) != 0 && err == NULL)
532 		err = got_error_from_errno("close");
533 	pack->fd = -1;
534 	free(pack->path_packfile);
535 	pack->path_packfile = NULL;
536 	pack->filesize = 0;
537 
538 	return err;
539 }
540 
541 static const struct got_error *
542 parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len,
543     struct got_pack *pack, off_t offset)
544 {
545 	uint8_t t = 0;
546 	uint64_t s = 0;
547 	uint8_t sizeN;
548 	size_t mapoff = 0;
549 	int i = 0;
550 
551 	*len = 0;
552 
553 	if (offset >= pack->filesize)
554 		return got_error(GOT_ERR_PACK_OFFSET);
555 
556 	if (pack->map) {
557 		mapoff = (size_t)offset;
558 	} else {
559 		if (lseek(pack->fd, offset, SEEK_SET) == -1)
560 			return got_error_from_errno("lseek");
561 	}
562 
563 	do {
564 		/* We do not support size values which don't fit in 64 bit. */
565 		if (i > 9)
566 			return got_error(GOT_ERR_NO_SPACE);
567 
568 		if (pack->map) {
569 			sizeN = *(pack->map + mapoff);
570 			mapoff += sizeof(sizeN);
571 		} else {
572 			ssize_t n = read(pack->fd, &sizeN, sizeof(sizeN));
573 			if (n < 0)
574 				return got_error_from_errno("read");
575 			if (n != sizeof(sizeN))
576 				return got_error(GOT_ERR_BAD_PACKFILE);
577 		}
578 		*len += sizeof(sizeN);
579 
580 		if (i == 0) {
581 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
582 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
583 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
584 		} else {
585 			size_t shift = 4 + 7 * (i - 1);
586 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
587 		}
588 		i++;
589 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
590 
591 	*type = t;
592 	*size = s;
593 	return NULL;
594 }
595 
596 static const struct got_error *
597 open_plain_object(struct got_object **obj, const char *path_packfile,
598     struct got_object_id *id, uint8_t type, off_t offset, size_t size, int idx)
599 {
600 	*obj = calloc(1, sizeof(**obj));
601 	if (*obj == NULL)
602 		return got_error_from_errno("calloc");
603 
604 	(*obj)->path_packfile = strdup(path_packfile);
605 	if ((*obj)->path_packfile == NULL) {
606 		const struct got_error *err = got_error_from_errno("strdup");
607 		free(*obj);
608 		*obj = NULL;
609 		return err;
610 	}
611 
612 	(*obj)->type = type;
613 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
614 	(*obj)->pack_idx = idx;
615 	(*obj)->hdrlen = 0;
616 	(*obj)->size = size;
617 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
618 	(*obj)->pack_offset = offset;
619 
620 	return NULL;
621 }
622 
623 static const struct got_error *
624 parse_negative_offset(int64_t *offset, size_t *len, struct got_pack *pack,
625     off_t delta_offset)
626 {
627 	int64_t o = 0;
628 	uint8_t offN;
629 	int i = 0;
630 
631 	*len = 0;
632 
633 	do {
634 		/* We do not support offset values which don't fit in 64 bit. */
635 		if (i > 8)
636 			return got_error(GOT_ERR_NO_SPACE);
637 
638 		if (pack->map) {
639 			size_t mapoff;
640 			if (delta_offset >= pack->filesize)
641 				return got_error(GOT_ERR_PACK_OFFSET);
642 			mapoff = (size_t)delta_offset + *len;
643 			offN = *(pack->map + mapoff);
644 		} else {
645 			ssize_t n;
646 			n = read(pack->fd, &offN, sizeof(offN));
647 			if (n < 0)
648 				return got_error_from_errno("read");
649 			if (n != sizeof(offN))
650 				return got_error(GOT_ERR_BAD_PACKFILE);
651 		}
652 		*len += sizeof(offN);
653 
654 		if (i == 0)
655 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
656 		else {
657 			o++;
658 			o <<= 7;
659 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
660 		}
661 		i++;
662 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
663 
664 	*offset = o;
665 	return NULL;
666 }
667 
668 static const struct got_error *
669 parse_offset_delta(off_t *base_offset, size_t *len, struct got_pack *pack,
670     off_t offset, int tslen)
671 {
672 	const struct got_error *err;
673 	int64_t negoffset;
674 	size_t negofflen;
675 
676 	*len = 0;
677 
678 	err = parse_negative_offset(&negoffset, &negofflen, pack,
679 	    offset + tslen);
680 	if (err)
681 		return err;
682 
683 	/* Compute the base object's offset (must be in the same pack file). */
684 	*base_offset = (offset - negoffset);
685 	if (*base_offset <= 0)
686 		return got_error(GOT_ERR_BAD_PACKFILE);
687 
688 	*len = negofflen;
689 	return NULL;
690 }
691 
692 static const struct got_error *
693 resolve_delta_chain(struct got_delta_chain *, struct got_packidx *,
694     struct got_pack *, off_t, size_t, int, size_t, unsigned int);
695 
696 static const struct got_error *
697 add_delta(struct got_delta_chain *deltas, off_t delta_offset, size_t tslen,
698     int delta_type, size_t delta_size, size_t delta_data_offset,
699     uint8_t *delta_buf, size_t delta_len)
700 {
701 	struct got_delta *delta;
702 
703 	delta = got_delta_open(delta_offset, tslen, delta_type, delta_size,
704 	    delta_data_offset, delta_buf,
705 	    delta_len);
706 	if (delta == NULL)
707 		return got_error_from_errno("got_delta_open");
708 	/* delta is freed in got_object_close() */
709 	deltas->nentries++;
710 	SIMPLEQ_INSERT_HEAD(&deltas->entries, delta, entry);
711 	return NULL;
712 }
713 
714 static const struct got_error *
715 resolve_offset_delta(struct got_delta_chain *deltas,
716     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
717     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
718 
719 {
720 	const struct got_error *err;
721 	off_t base_offset;
722 	uint8_t base_type;
723 	uint64_t base_size;
724 	size_t base_tslen;
725 	off_t delta_data_offset;
726 	uint8_t *delta_buf;
727 	size_t delta_len, consumed;
728 
729 	err = parse_offset_delta(&base_offset, &consumed, pack,
730 	    delta_offset, tslen);
731 	if (err)
732 		return err;
733 
734 	delta_data_offset = delta_offset + tslen + consumed;
735 	if (delta_data_offset >= pack->filesize)
736 		return got_error(GOT_ERR_PACK_OFFSET);
737 
738 	if (pack->map == NULL) {
739 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
740 		if (delta_data_offset == -1)
741 			return got_error_from_errno("lseek");
742 	}
743 
744 	if (pack->map) {
745 		size_t mapoff = (size_t)delta_data_offset;
746 		err = got_inflate_to_mem_mmap(&delta_buf, &delta_len, pack->map,
747 		    mapoff, pack->filesize - mapoff);
748 		if (err)
749 			return err;
750 	} else {
751 
752 		err = got_inflate_to_mem_fd(&delta_buf, &delta_len, pack->fd);
753 		if (err)
754 			return err;
755 	}
756 
757 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
758 	    delta_data_offset, delta_buf, delta_len);
759 	if (err)
760 		return err;
761 
762 	/* An offset delta must be in the same packfile. */
763 	if (base_offset >= pack->filesize)
764 		return got_error(GOT_ERR_PACK_OFFSET);
765 
766 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
767 	    pack, base_offset);
768 	if (err)
769 		return err;
770 
771 	return resolve_delta_chain(deltas, packidx, pack, base_offset,
772 	    base_tslen, base_type, base_size, recursion - 1);
773 }
774 
775 static const struct got_error *
776 resolve_ref_delta(struct got_delta_chain *deltas, struct got_packidx *packidx,
777     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
778     size_t delta_size, unsigned int recursion)
779 {
780 	const struct got_error *err;
781 	struct got_object_id id;
782 	int idx;
783 	off_t base_offset;
784 	uint8_t base_type;
785 	uint64_t base_size;
786 	size_t base_tslen;
787 	off_t delta_data_offset;
788 	uint8_t *delta_buf;
789 	size_t delta_len;
790 
791 	if (delta_offset >= pack->filesize)
792 		return got_error(GOT_ERR_PACK_OFFSET);
793 	delta_data_offset = delta_offset + tslen;
794 	if (delta_data_offset >= pack->filesize)
795 		return got_error(GOT_ERR_PACK_OFFSET);
796 
797 	if (pack->map == NULL) {
798 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
799 		if (delta_data_offset == -1)
800 			return got_error_from_errno("lseek");
801 	}
802 
803 	if (pack->map) {
804 		size_t mapoff = (size_t)delta_data_offset;
805 		memcpy(&id, pack->map + mapoff, sizeof(id));
806 		mapoff += sizeof(id);
807 		err = got_inflate_to_mem_mmap(&delta_buf, &delta_len, pack->map,
808 		    mapoff, pack->filesize - mapoff);
809 		if (err)
810 			return err;
811 	} else {
812 		ssize_t n = read(pack->fd, &id, sizeof(id));
813 		if (n < 0)
814 			return got_error_from_errno("read");
815 		if (n != sizeof(id))
816 			return got_error(GOT_ERR_BAD_PACKFILE);
817 		err = got_inflate_to_mem_fd(&delta_buf, &delta_len, pack->fd);
818 		if (err)
819 			return err;
820 	}
821 
822 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
823 	    delta_data_offset, delta_buf, delta_len);
824 	if (err)
825 		return err;
826 
827 	/* Delta base must be in the same pack file. */
828 	idx = got_packidx_get_object_idx(packidx, &id);
829 	if (idx == -1)
830 		return got_error(GOT_ERR_BAD_PACKFILE);
831 
832 	base_offset = get_object_offset(packidx, idx);
833 	if (base_offset == (uint64_t)-1)
834 		return got_error(GOT_ERR_BAD_PACKIDX);
835 
836 	if (base_offset >= pack->filesize)
837 		return got_error(GOT_ERR_PACK_OFFSET);
838 
839 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
840 	    pack, base_offset);
841 	if (err)
842 		return err;
843 
844 	return resolve_delta_chain(deltas, packidx, pack, base_offset,
845 	    base_tslen, base_type, base_size, recursion - 1);
846 }
847 
848 static const struct got_error *
849 resolve_delta_chain(struct got_delta_chain *deltas, struct got_packidx *packidx,
850     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
851     size_t delta_size, unsigned int recursion)
852 {
853 	const struct got_error *err = NULL;
854 
855 	if (--recursion == 0)
856 		return got_error(GOT_ERR_RECURSION);
857 
858 	switch (delta_type) {
859 	case GOT_OBJ_TYPE_COMMIT:
860 	case GOT_OBJ_TYPE_TREE:
861 	case GOT_OBJ_TYPE_BLOB:
862 	case GOT_OBJ_TYPE_TAG:
863 		/* Plain types are the final delta base. Recursion ends. */
864 		err = add_delta(deltas, delta_offset, tslen, delta_type,
865 		    delta_size, 0, NULL, 0);
866 		break;
867 	case GOT_OBJ_TYPE_OFFSET_DELTA:
868 		err = resolve_offset_delta(deltas, packidx, pack,
869 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
870 		break;
871 	case GOT_OBJ_TYPE_REF_DELTA:
872 		err = resolve_ref_delta(deltas, packidx, pack,
873 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
874 		break;
875 	default:
876 		return got_error(GOT_ERR_OBJ_TYPE);
877 	}
878 
879 	return err;
880 }
881 
882 static const struct got_error *
883 open_delta_object(struct got_object **obj, struct got_packidx *packidx,
884     struct got_pack *pack, struct got_object_id *id, off_t offset,
885     size_t tslen, int delta_type, size_t delta_size, int idx)
886 {
887 	const struct got_error *err = NULL;
888 	int resolved_type;
889 
890 	*obj = calloc(1, sizeof(**obj));
891 	if (*obj == NULL)
892 		return got_error_from_errno("calloc");
893 
894 	(*obj)->flags = 0;
895 	(*obj)->hdrlen = 0;
896 	(*obj)->size = 0; /* Not known because deltas aren't applied yet. */
897 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
898 	(*obj)->pack_offset = offset + tslen;
899 
900 	SIMPLEQ_INIT(&(*obj)->deltas.entries);
901 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
902 
903 	(*obj)->path_packfile = strdup(pack->path_packfile);
904 	if ((*obj)->path_packfile == NULL) {
905 		err = got_error_from_errno("strdup");
906 		goto done;
907 	}
908 	(*obj)->flags |= GOT_OBJ_FLAG_PACKED;
909 	(*obj)->pack_idx = idx;
910 
911 	err = resolve_delta_chain(&(*obj)->deltas, packidx, pack, offset,
912 	    tslen, delta_type, delta_size, GOT_DELTA_CHAIN_RECURSION_MAX);
913 	if (err)
914 		goto done;
915 
916 	err = got_delta_chain_get_base_type(&resolved_type, &(*obj)->deltas);
917 	if (err)
918 		goto done;
919 	(*obj)->type = resolved_type;
920 done:
921 	if (err) {
922 		got_object_close(*obj);
923 		*obj = NULL;
924 	}
925 	return err;
926 }
927 
928 const struct got_error *
929 got_packfile_open_object(struct got_object **obj, struct got_pack *pack,
930     struct got_packidx *packidx, int idx, struct got_object_id *id)
931 {
932 	const struct got_error *err = NULL;
933 	off_t offset;
934 	uint8_t type;
935 	uint64_t size;
936 	size_t tslen;
937 
938 	*obj = NULL;
939 
940 	offset = get_object_offset(packidx, idx);
941 	if (offset == (uint64_t)-1)
942 		return got_error(GOT_ERR_BAD_PACKIDX);
943 
944 	err = parse_object_type_and_size(&type, &size, &tslen, pack, offset);
945 	if (err)
946 		return err;
947 
948 	switch (type) {
949 	case GOT_OBJ_TYPE_COMMIT:
950 	case GOT_OBJ_TYPE_TREE:
951 	case GOT_OBJ_TYPE_BLOB:
952 	case GOT_OBJ_TYPE_TAG:
953 		err = open_plain_object(obj, pack->path_packfile, id, type,
954 		    offset + tslen, size, idx);
955 		break;
956 	case GOT_OBJ_TYPE_OFFSET_DELTA:
957 	case GOT_OBJ_TYPE_REF_DELTA:
958 		err = open_delta_object(obj, packidx, pack, id, offset,
959 		    tslen, type, size, idx);
960 		break;
961 	default:
962 		err = got_error(GOT_ERR_OBJ_TYPE);
963 		break;
964 	}
965 
966 	return err;
967 }
968 
969 static const struct got_error *
970 get_delta_chain_max_size(uint64_t *max_size, struct got_delta_chain *deltas)
971 {
972 	struct got_delta *delta;
973 	uint64_t base_size = 0, result_size = 0;
974 
975 	*max_size = 0;
976 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
977 		/* Plain object types are the delta base. */
978 		if (delta->type != GOT_OBJ_TYPE_COMMIT &&
979 		    delta->type != GOT_OBJ_TYPE_TREE &&
980 		    delta->type != GOT_OBJ_TYPE_BLOB &&
981 		    delta->type != GOT_OBJ_TYPE_TAG) {
982 			const struct got_error *err;
983 			err = got_delta_get_sizes(&base_size, &result_size,
984 			    delta->delta_buf, delta->delta_len);
985 			if (err)
986 				return err;
987 		} else
988 			base_size = delta->size;
989 		if (base_size > *max_size)
990 			*max_size = base_size;
991 		if (result_size > *max_size)
992 			*max_size = result_size;
993 	}
994 
995 	return NULL;
996 }
997 
998 const struct got_error *
999 got_pack_get_max_delta_object_size(uint64_t *size, struct got_object *obj)
1000 {
1001 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0)
1002 		return got_error(GOT_ERR_OBJ_TYPE);
1003 
1004 	return get_delta_chain_max_size(size, &obj->deltas);
1005 }
1006 
1007 static const struct got_error *
1008 dump_delta_chain_to_file(size_t *result_size, struct got_delta_chain *deltas,
1009     struct got_pack *pack, FILE *outfile, FILE *base_file, FILE *accum_file)
1010 {
1011 	const struct got_error *err = NULL;
1012 	struct got_delta *delta;
1013 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1014 	size_t base_bufsz = 0, accum_size = 0;
1015 	uint64_t max_size;
1016 	int n = 0;
1017 
1018 	*result_size = 0;
1019 
1020 	if (SIMPLEQ_EMPTY(&deltas->entries))
1021 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1022 
1023 	/* We process small enough files entirely in memory for speed. */
1024 	err = get_delta_chain_max_size(&max_size, deltas);
1025 	if (err)
1026 		return err;
1027 	if (max_size < GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
1028 		accum_buf = malloc(max_size);
1029 		if (accum_buf == NULL)
1030 			return got_error_from_errno("malloc");
1031 		base_file = NULL;
1032 		accum_file = NULL;
1033 	}
1034 
1035 	/* Deltas are ordered in ascending order. */
1036 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1037 		if (n == 0) {
1038 			size_t mapoff;
1039 			off_t delta_data_offset;
1040 
1041 			/* Plain object types are the delta base. */
1042 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1043 			    delta->type != GOT_OBJ_TYPE_TREE &&
1044 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1045 			    delta->type != GOT_OBJ_TYPE_TAG) {
1046 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1047 				goto done;
1048 			}
1049 
1050 			delta_data_offset = delta->offset + delta->tslen;
1051 			if (delta_data_offset >= pack->filesize) {
1052 				err = got_error(GOT_ERR_PACK_OFFSET);
1053 				goto done;
1054 			}
1055 			if (pack->map == NULL) {
1056 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1057 				    == -1) {
1058 					err = got_error_from_errno("lseek");
1059 					goto done;
1060 				}
1061 			}
1062 			if (base_file) {
1063 				if (pack->map) {
1064 					mapoff = (size_t)delta_data_offset;
1065 					err = got_inflate_to_file_mmap(
1066 					    &base_bufsz, pack->map, mapoff,
1067 					    pack->filesize - mapoff, base_file);
1068 				} else
1069 					err = got_inflate_to_file_fd(
1070 					    &base_bufsz, pack->fd, base_file);
1071 			} else {
1072 				if (pack->map) {
1073 					mapoff = (size_t)delta_data_offset;
1074 					err = got_inflate_to_mem_mmap(&base_buf,
1075 					    &base_bufsz, pack->map, mapoff,
1076 					    pack->filesize - mapoff);
1077 				} else
1078 					err = got_inflate_to_mem_fd(&base_buf,
1079 					    &base_bufsz, pack->fd);
1080 			}
1081 			if (err)
1082 				goto done;
1083 			n++;
1084 			if (base_file)
1085 				rewind(base_file);
1086 			continue;
1087 		}
1088 
1089 		if (base_buf) {
1090 			err = got_delta_apply_in_mem(base_buf, base_bufsz,
1091 			    delta->delta_buf, delta->delta_len, accum_buf,
1092 			    &accum_size, max_size);
1093 			n++;
1094 		} else {
1095 			err = got_delta_apply(base_file, delta->delta_buf,
1096 			    delta->delta_len,
1097 			    /* Final delta application writes to output file. */
1098 			    ++n < deltas->nentries ? accum_file : outfile,
1099 			    &accum_size);
1100 		}
1101 		if (err)
1102 			goto done;
1103 
1104 		if (n < deltas->nentries) {
1105 			/* Accumulated delta becomes the new base. */
1106 			if (base_buf) {
1107 				uint8_t *tmp = accum_buf;
1108 				/*
1109 				 * Base buffer switches roles with accumulation
1110 				 * buffer. Ensure it can hold the largest
1111 				 * result in the delta chain. The initial
1112 				 * allocation might have been smaller.
1113 				 */
1114 				if (base_bufsz < max_size) {
1115 					uint8_t *p;
1116 					p = reallocarray(base_buf, 1, max_size);
1117 					if (p == NULL) {
1118 						err = got_error_from_errno(
1119 						    "reallocarray");
1120 						goto done;
1121 					}
1122 					base_buf = p;
1123 					base_bufsz = max_size;
1124 				}
1125 				accum_buf = base_buf;
1126 				base_buf = tmp;
1127 			} else {
1128 				FILE *tmp = accum_file;
1129 				accum_file = base_file;
1130 				base_file = tmp;
1131 				rewind(base_file);
1132 				rewind(accum_file);
1133 			}
1134 		}
1135 	}
1136 
1137 done:
1138 	free(base_buf);
1139 	if (accum_buf) {
1140 		size_t len = fwrite(accum_buf, 1, accum_size, outfile);
1141 		free(accum_buf);
1142 		if (len != accum_size)
1143 			err = got_ferror(outfile, GOT_ERR_IO);
1144 	}
1145 	rewind(outfile);
1146 	if (err == NULL)
1147 		*result_size = accum_size;
1148 	return err;
1149 }
1150 
1151 static const struct got_error *
1152 dump_delta_chain_to_mem(uint8_t **outbuf, size_t *outlen,
1153     struct got_delta_chain *deltas, struct got_pack *pack)
1154 {
1155 	const struct got_error *err = NULL;
1156 	struct got_delta *delta;
1157 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1158 	size_t base_bufsz = 0, accum_size = 0;
1159 	uint64_t max_size;
1160 	int n = 0;
1161 
1162 	*outbuf = NULL;
1163 	*outlen = 0;
1164 
1165 	if (SIMPLEQ_EMPTY(&deltas->entries))
1166 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1167 
1168 	err = get_delta_chain_max_size(&max_size, deltas);
1169 	if (err)
1170 		return err;
1171 	accum_buf = malloc(max_size);
1172 	if (accum_buf == NULL)
1173 		return got_error_from_errno("malloc");
1174 
1175 	/* Deltas are ordered in ascending order. */
1176 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1177 		if (n == 0) {
1178 			size_t delta_data_offset;
1179 
1180 			/* Plain object types are the delta base. */
1181 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1182 			    delta->type != GOT_OBJ_TYPE_TREE &&
1183 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1184 			    delta->type != GOT_OBJ_TYPE_TAG) {
1185 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1186 				goto done;
1187 			}
1188 
1189 			delta_data_offset = delta->offset + delta->tslen;
1190 			if (delta_data_offset >= pack->filesize) {
1191 				err = got_error(GOT_ERR_PACK_OFFSET);
1192 				goto done;
1193 			}
1194 			if (pack->map) {
1195 				size_t mapoff = (size_t)delta_data_offset;
1196 				err = got_inflate_to_mem_mmap(&base_buf,
1197 				    &base_bufsz, pack->map, mapoff,
1198 				    pack->filesize - mapoff);
1199 			} else {
1200 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1201 				    == -1) {
1202 					err = got_error_from_errno("lseek");
1203 					goto done;
1204 				}
1205 				err = got_inflate_to_mem_fd(&base_buf,
1206 				    &base_bufsz, pack->fd);
1207 			}
1208 			if (err)
1209 				goto done;
1210 			n++;
1211 			continue;
1212 		}
1213 
1214 		err = got_delta_apply_in_mem(base_buf, base_bufsz,
1215 		    delta->delta_buf, delta->delta_len, accum_buf,
1216 		    &accum_size, max_size);
1217 		n++;
1218 		if (err)
1219 			goto done;
1220 
1221 		if (n < deltas->nentries) {
1222 			/* Accumulated delta becomes the new base. */
1223 			uint8_t *tmp = accum_buf;
1224 			/*
1225 			 * Base buffer switches roles with accumulation buffer.
1226 			 * Ensure it can hold the largest result in the delta
1227 			 * chain. Initial allocation might have been smaller.
1228 			 */
1229 			if (base_bufsz < max_size) {
1230 				uint8_t *p;
1231 				p = reallocarray(base_buf, 1, max_size);
1232 				if (p == NULL) {
1233 					err = got_error_from_errno(
1234 					    "reallocarray");
1235 					goto done;
1236 				}
1237 				base_buf = p;
1238 				base_bufsz = max_size;
1239 			}
1240 			accum_buf = base_buf;
1241 			base_buf = tmp;
1242 		}
1243 	}
1244 
1245 done:
1246 	free(base_buf);
1247 	if (err) {
1248 		free(accum_buf);
1249 		*outbuf = NULL;
1250 		*outlen = 0;
1251 	} else {
1252 		*outbuf = accum_buf;
1253 		*outlen = accum_size;
1254 	}
1255 	return err;
1256 }
1257 
1258 const struct got_error *
1259 got_packfile_extract_object(struct got_pack *pack, struct got_object *obj,
1260     FILE *outfile, FILE *base_file, FILE *accum_file)
1261 {
1262 	const struct got_error *err = NULL;
1263 
1264 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1265 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1266 
1267 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1268 		if (obj->pack_offset >= pack->filesize)
1269 			return got_error(GOT_ERR_PACK_OFFSET);
1270 
1271 		if (pack->map) {
1272 			size_t mapoff = (size_t)obj->pack_offset;
1273 			err = got_inflate_to_file_mmap(&obj->size, pack->map,
1274 			    mapoff, pack->filesize - mapoff, outfile);
1275 		} else {
1276 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1277 				return got_error_from_errno("lseek");
1278 			err = got_inflate_to_file_fd(&obj->size, pack->fd,
1279 			    outfile);
1280 		}
1281 	} else
1282 		err = dump_delta_chain_to_file(&obj->size, &obj->deltas, pack,
1283 		    outfile, base_file, accum_file);
1284 
1285 	return err;
1286 }
1287 
1288 const struct got_error *
1289 got_packfile_extract_object_to_mem(uint8_t **buf, size_t *len,
1290     struct got_object *obj, struct got_pack *pack)
1291 {
1292 	const struct got_error *err = NULL;
1293 
1294 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1295 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1296 
1297 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1298 		if (obj->pack_offset >= pack->filesize)
1299 			return got_error(GOT_ERR_PACK_OFFSET);
1300 		if (pack->map) {
1301 			size_t mapoff = (size_t)obj->pack_offset;
1302 			err = got_inflate_to_mem_mmap(buf, len, pack->map,
1303 			    mapoff, pack->filesize - mapoff);
1304 		} else {
1305 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1306 				return got_error_from_errno("lseek");
1307 			err = got_inflate_to_mem_fd(buf, len, pack->fd);
1308 		}
1309 	} else
1310 		err = dump_delta_chain_to_mem(buf, len, &obj->deltas, pack);
1311 
1312 	return err;
1313 }