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Date:: Tue Nov 26 22:43:12 2019 UTC
Message:: remove obj->path_packfile which is unused nowadays; saves a few free() calls
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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_delta_cache.h"
43 #include "got_lib_inflate.h"
44 #include "got_lib_object.h"
45 #include "got_lib_object_parse.h"
46 #include "got_lib_privsep.h"
47 #include "got_lib_pack.h"
48 
49 #ifndef nitems
50 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
51 #endif
52 
53 #ifndef MIN
54 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
55 #endif
56 
57 static const struct got_error *
58 verify_fanout_table(uint32_t *fanout_table)
59 {
60 	int i;
61 
62 	for (i = 0; i < 0xff - 1; i++) {
63 		if (be32toh(fanout_table[i]) > be32toh(fanout_table[i + 1]))
64 			return got_error(GOT_ERR_BAD_PACKIDX);
65 	}
66 
67 	return NULL;
68 }
69 
70 const struct got_error *
71 got_packidx_init_hdr(struct got_packidx *p, int verify)
72 {
73 	const struct got_error *err = NULL;
74 	struct got_packidx_v2_hdr *h;
75 	SHA1_CTX ctx;
76 	uint8_t sha1[SHA1_DIGEST_LENGTH];
77 	size_t nobj, len_fanout, len_ids, offset, remain;
78 	ssize_t n;
79 	int i;
80 
81 	SHA1Init(&ctx);
82 
83 	h = &p->hdr;
84 	offset = 0;
85 	remain = p->len;
86 
87 	if (remain < sizeof(*h->magic)) {
88 		err = got_error(GOT_ERR_BAD_PACKIDX);
89 		goto done;
90 	}
91 	if (p->map)
92 		h->magic = (uint32_t *)(p->map + offset);
93 	else {
94 		h->magic = malloc(sizeof(*h->magic));
95 		if (h->magic == NULL) {
96 			err = got_error_from_errno("malloc");
97 			goto done;
98 		}
99 		n = read(p->fd, h->magic, sizeof(*h->magic));
100 		if (n < 0) {
101 			err = got_error_from_errno("read");
102 			goto done;
103 		} else if (n != sizeof(*h->magic)) {
104 			err = got_error(GOT_ERR_BAD_PACKIDX);
105 			goto done;
106 		}
107 	}
108 	if (betoh32(*h->magic) != GOT_PACKIDX_V2_MAGIC) {
109 		err = got_error(GOT_ERR_BAD_PACKIDX);
110 		goto done;
111 	}
112 	offset += sizeof(*h->magic);
113 	remain -= sizeof(*h->magic);
114 
115 	if (verify)
116 		SHA1Update(&ctx, (uint8_t *)h->magic, sizeof(*h->magic));
117 
118 	if (remain < sizeof(*h->version)) {
119 		err = got_error(GOT_ERR_BAD_PACKIDX);
120 		goto done;
121 	}
122 	if (p->map)
123 		h->version = (uint32_t *)(p->map + offset);
124 	else {
125 		h->version = malloc(sizeof(*h->version));
126 		if (h->version == NULL) {
127 			err = got_error_from_errno("malloc");
128 			goto done;
129 		}
130 		n = read(p->fd, h->version, sizeof(*h->version));
131 		if (n < 0) {
132 			err = got_error_from_errno("read");
133 			goto done;
134 		} else if (n != sizeof(*h->version)) {
135 			err = got_error(GOT_ERR_BAD_PACKIDX);
136 			goto done;
137 		}
138 	}
139 	if (betoh32(*h->version) != GOT_PACKIDX_VERSION) {
140 		err = got_error(GOT_ERR_BAD_PACKIDX);
141 		goto done;
142 	}
143 	offset += sizeof(*h->version);
144 	remain -= sizeof(*h->version);
145 
146 	if (verify)
147 		SHA1Update(&ctx, (uint8_t *)h->version, sizeof(*h->version));
148 
149 	len_fanout =
150 	    sizeof(*h->fanout_table) * GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS;
151 	if (remain < len_fanout) {
152 		err = got_error(GOT_ERR_BAD_PACKIDX);
153 		goto done;
154 	}
155 	if (p->map)
156 		h->fanout_table = (uint32_t *)(p->map + offset);
157 	else {
158 		h->fanout_table = malloc(len_fanout);
159 		if (h->fanout_table == NULL) {
160 			err = got_error_from_errno("malloc");
161 			goto done;
162 		}
163 		n = read(p->fd, h->fanout_table, len_fanout);
164 		if (n < 0) {
165 			err = got_error_from_errno("read");
166 			goto done;
167 		} else if (n != len_fanout) {
168 			err = got_error(GOT_ERR_BAD_PACKIDX);
169 			goto done;
170 		}
171 	}
172 	err = verify_fanout_table(h->fanout_table);
173 	if (err)
174 		goto done;
175 	if (verify)
176 		SHA1Update(&ctx, (uint8_t *)h->fanout_table, len_fanout);
177 	offset += len_fanout;
178 	remain -= len_fanout;
179 
180 	nobj = betoh32(h->fanout_table[0xff]);
181 	len_ids = nobj * sizeof(*h->sorted_ids);
182 	if (len_ids <= nobj || len_ids > remain) {
183 		err = got_error(GOT_ERR_BAD_PACKIDX);
184 		goto done;
185 	}
186 	if (p->map)
187 		h->sorted_ids =
188 		    (struct got_packidx_object_id *)((uint8_t*)(p->map + offset));
189 	else {
190 		h->sorted_ids = malloc(len_ids);
191 		if (h->sorted_ids == NULL) {
192 			err = got_error(GOT_ERR_BAD_PACKIDX);
193 			goto done;
194 		}
195 		n = read(p->fd, h->sorted_ids, len_ids);
196 		if (n < 0)
197 			err = got_error_from_errno("read");
198 		else if (n != len_ids) {
199 			err = got_error(GOT_ERR_BAD_PACKIDX);
200 			goto done;
201 		}
202 	}
203 	if (verify)
204 		SHA1Update(&ctx, (uint8_t *)h->sorted_ids, len_ids);
205 	offset += len_ids;
206 	remain -= len_ids;
207 
208 	if (remain < nobj * sizeof(*h->crc32)) {
209 		err = got_error(GOT_ERR_BAD_PACKIDX);
210 		goto done;
211 	}
212 	if (p->map)
213 		h->crc32 = (uint32_t *)((uint8_t*)(p->map + offset));
214 	else {
215 		h->crc32 = malloc(nobj * sizeof(*h->crc32));
216 		if (h->crc32 == NULL) {
217 			err = got_error_from_errno("malloc");
218 			goto done;
219 		}
220 		n = read(p->fd, h->crc32, nobj * sizeof(*h->crc32));
221 		if (n < 0)
222 			err = got_error_from_errno("read");
223 		else if (n != nobj * sizeof(*h->crc32)) {
224 			err = got_error(GOT_ERR_BAD_PACKIDX);
225 			goto done;
226 		}
227 	}
228 	if (verify)
229 		SHA1Update(&ctx, (uint8_t *)h->crc32, nobj * sizeof(*h->crc32));
230 	remain -= nobj * sizeof(*h->crc32);
231 	offset += nobj * sizeof(*h->crc32);
232 
233 	if (remain < nobj * sizeof(*h->offsets)) {
234 		err = got_error(GOT_ERR_BAD_PACKIDX);
235 		goto done;
236 	}
237 	if (p->map)
238 		h->offsets = (uint32_t *)((uint8_t*)(p->map + offset));
239 	else {
240 		h->offsets = malloc(nobj * sizeof(*h->offsets));
241 		if (h->offsets == NULL) {
242 			err = got_error_from_errno("malloc");
243 			goto done;
244 		}
245 		n = read(p->fd, h->offsets, nobj * sizeof(*h->offsets));
246 		if (n < 0)
247 			err = got_error_from_errno("read");
248 		else if (n != nobj * sizeof(*h->offsets)) {
249 			err = got_error(GOT_ERR_BAD_PACKIDX);
250 			goto done;
251 		}
252 	}
253 	if (verify)
254 		SHA1Update(&ctx, (uint8_t *)h->offsets,
255 		    nobj * sizeof(*h->offsets));
256 	remain -= nobj * sizeof(*h->offsets);
257 	offset += nobj * sizeof(*h->offsets);
258 
259 	/* Large file offsets are contained only in files > 2GB. */
260 	for (i = 0; i < nobj; i++) {
261 		uint32_t o = betoh32(h->offsets[i]);
262 		if (o & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX)
263 			p->nlargeobj++;
264 	}
265 	if (p->nlargeobj == 0)
266 		goto checksum;
267 
268 	if (remain < p->nlargeobj * sizeof(*h->large_offsets)) {
269 		err = got_error(GOT_ERR_BAD_PACKIDX);
270 		goto done;
271 	}
272 	if (p->map)
273 		h->large_offsets = (uint64_t *)((uint8_t*)(p->map + offset));
274 	else {
275 		h->large_offsets = malloc(p->nlargeobj *
276 		    sizeof(*h->large_offsets));
277 		if (h->large_offsets == NULL) {
278 			err = got_error_from_errno("malloc");
279 			goto done;
280 		}
281 		n = read(p->fd, h->large_offsets,
282 		    p->nlargeobj * sizeof(*h->large_offsets));
283 		if (n < 0)
284 			err = got_error_from_errno("read");
285 		else if (n != p->nlargeobj * sizeof(*h->large_offsets)) {
286 			err = got_error(GOT_ERR_BAD_PACKIDX);
287 			goto done;
288 		}
289 	}
290 	if (verify)
291 		SHA1Update(&ctx, (uint8_t*)h->large_offsets,
292 		    p->nlargeobj * sizeof(*h->large_offsets));
293 	remain -= p->nlargeobj * sizeof(*h->large_offsets);
294 	offset += p->nlargeobj * sizeof(*h->large_offsets);
295 
296 checksum:
297 	if (remain < sizeof(*h->trailer)) {
298 		err = got_error(GOT_ERR_BAD_PACKIDX);
299 		goto done;
300 	}
301 	if (p->map)
302 		h->trailer =
303 		    (struct got_packidx_trailer *)((uint8_t*)(p->map + offset));
304 	else {
305 		h->trailer = malloc(sizeof(*h->trailer));
306 		if (h->trailer == NULL) {
307 			err = got_error_from_errno("malloc");
308 			goto done;
309 		}
310 		n = read(p->fd, h->trailer, sizeof(*h->trailer));
311 		if (n < 0)
312 			err = got_error_from_errno("read");
313 		else if (n != sizeof(*h->trailer)) {
314 			err = got_error(GOT_ERR_BAD_PACKIDX);
315 			goto done;
316 		}
317 	}
318 	if (verify) {
319 		SHA1Update(&ctx, h->trailer->packfile_sha1, SHA1_DIGEST_LENGTH);
320 		SHA1Final(sha1, &ctx);
321 		if (memcmp(h->trailer->packidx_sha1, sha1,
322 		    SHA1_DIGEST_LENGTH) != 0)
323 			err = got_error(GOT_ERR_PACKIDX_CSUM);
324 	}
325 done:
326 	return err;
327 }
328 
329 const struct got_error *
330 got_packidx_open(struct got_packidx **packidx, const char *path, int verify)
331 {
332 	const struct got_error *err = NULL;
333 	struct got_packidx *p;
334 	struct stat sb;
335 
336 	*packidx = NULL;
337 
338 	p = calloc(1, sizeof(*p));
339 	if (p == NULL)
340 		return got_error_from_errno("calloc");
341 
342 	p->fd = open(path, O_RDONLY | O_NOFOLLOW);
343 	if (p->fd == -1) {
344 		err = got_error_from_errno2("open", path);
345 		free(p);
346 		return err;
347 	}
348 
349 	if (fstat(p->fd, &sb) != 0) {
350 		err = got_error_from_errno2("fstat", path);
351 		close(p->fd);
352 		free(p);
353 		return err;
354 	}
355 	p->len = sb.st_size;
356 	if (p->len < sizeof(p->hdr)) {
357 		err = got_error(GOT_ERR_BAD_PACKIDX);
358 		close(p->fd);
359 		free(p);
360 		return err;
361 	}
362 
363 	p->path_packidx = strdup(path);
364 	if (p->path_packidx == NULL) {
365 		err = got_error_from_errno("strdup");
366 		goto done;
367 	}
368 
369 #ifndef GOT_PACK_NO_MMAP
370 	p->map = mmap(NULL, p->len, PROT_READ, MAP_PRIVATE, p->fd, 0);
371 	if (p->map == MAP_FAILED) {
372 		if (errno != ENOMEM) {
373 			err = got_error_from_errno("mmap");
374 			goto done;
375 		}
376 		p->map = NULL; /* fall back to read(2) */
377 	}
378 #endif
379 
380 	err = got_packidx_init_hdr(p, verify);
381 done:
382 	if (err)
383 		got_packidx_close(p);
384 	else
385 		*packidx = p;
386 
387 	return err;
388 }
389 
390 const struct got_error *
391 got_packidx_close(struct got_packidx *packidx)
392 {
393 	const struct got_error *err = NULL;
394 
395 	free(packidx->path_packidx);
396 	if (packidx->map) {
397 		if (munmap(packidx->map, packidx->len) == -1)
398 			err = got_error_from_errno("munmap");
399 	} else {
400 		free(packidx->hdr.magic);
401 		free(packidx->hdr.version);
402 		free(packidx->hdr.fanout_table);
403 		free(packidx->hdr.sorted_ids);
404 		free(packidx->hdr.crc32);
405 		free(packidx->hdr.offsets);
406 		free(packidx->hdr.large_offsets);
407 		free(packidx->hdr.trailer);
408 	}
409 	if (close(packidx->fd) != 0 && err == NULL)
410 		err = got_error_from_errno("close");
411 	free(packidx);
412 
413 	return err;
414 }
415 
416 static off_t
417 get_object_offset(struct got_packidx *packidx, int idx)
418 {
419 	uint32_t offset = betoh32(packidx->hdr.offsets[idx]);
420 	if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
421 		uint64_t loffset;
422 		idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
423 		if (idx < 0 || idx >= packidx->nlargeobj ||
424 		    packidx->hdr.large_offsets == NULL)
425 			return -1;
426 		loffset = betoh64(packidx->hdr.large_offsets[idx]);
427 		return (loffset > INT64_MAX ? -1 : (off_t)loffset);
428 	}
429 	return (off_t)(offset & GOT_PACKIDX_OFFSET_VAL_MASK);
430 }
431 
432 int
433 got_packidx_get_object_idx(struct got_packidx *packidx, struct got_object_id *id)
434 {
435 	u_int8_t id0 = id->sha1[0];
436 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
437 	int left = 0, right = totobj - 1;
438 
439 	if (id0 > 0)
440 		left = betoh32(packidx->hdr.fanout_table[id0 - 1]);
441 
442 	while (left <= right) {
443 		struct got_packidx_object_id *oid;
444 		int i, cmp;
445 
446 		i = ((left + right) / 2);
447 		oid = &packidx->hdr.sorted_ids[i];
448 		cmp = memcmp(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
449 		if (cmp == 0)
450 			return i;
451 		else if (cmp > 0)
452 			left = i + 1;
453 		else if (cmp < 0)
454 			right = i - 1;
455 	}
456 
457 	return -1;
458 }
459 
460 const struct got_error *
461 got_packidx_match_id_str_prefix(struct got_object_id_queue *matched_ids,
462     struct got_packidx *packidx, const char *id_str_prefix)
463 {
464 	const struct got_error *err = NULL;
465 	u_int8_t id0;
466 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
467 	char hex[3];
468 	size_t prefix_len = strlen(id_str_prefix);
469 	struct got_packidx_object_id *oid;
470 	int i;
471 
472 	SIMPLEQ_INIT(matched_ids);
473 
474 	if (prefix_len < 2)
475 		return got_error_path(id_str_prefix, GOT_ERR_BAD_OBJ_ID_STR);
476 
477 	hex[0] = id_str_prefix[0];
478 	hex[1] = id_str_prefix[1];
479 	hex[2] = '\0';
480 	if (!got_parse_xdigit(&id0, hex))
481 		return got_error_path(id_str_prefix, GOT_ERR_BAD_OBJ_ID_STR);
482 
483 	i = betoh32(packidx->hdr.fanout_table[id0 - 1]);
484 	if (i == 0)
485 		return NULL;
486 
487 	oid = &packidx->hdr.sorted_ids[i];
488 	while (i < totobj && oid->sha1[0] == id0) {
489 		char id_str[SHA1_DIGEST_STRING_LENGTH];
490 		struct got_object_qid *qid;
491 		int cmp;
492 
493 		if (!got_sha1_digest_to_str(oid->sha1, id_str, sizeof(id_str)))
494 		        return got_error(GOT_ERR_NO_SPACE);
495 
496 		cmp = strncmp(id_str, id_str_prefix, prefix_len);
497 		if (cmp < 0) {
498 			oid = &packidx->hdr.sorted_ids[++i];
499 			continue;
500 		} else if (cmp > 0)
501 			break;
502 
503 		err = got_object_qid_alloc_partial(&qid);
504 		if (err)
505 			break;
506 		memcpy(qid->id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
507 		SIMPLEQ_INSERT_TAIL(matched_ids, qid, entry);
508 
509 		oid = &packidx->hdr.sorted_ids[++i];
510 	}
511 
512 	if (err)
513 		got_object_id_queue_free(matched_ids);
514 	return err;
515 }
516 
517 const struct got_error *
518 got_pack_stop_privsep_child(struct got_pack *pack)
519 {
520 	const struct got_error *err = NULL;
521 
522 	if (pack->privsep_child == NULL)
523 		return NULL;
524 
525 	err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
526 	if (err)
527 		return err;
528 	err = got_privsep_wait_for_child(pack->privsep_child->pid);
529 	if (close(pack->privsep_child->imsg_fd) != 0 && err == NULL)
530 		err = got_error_from_errno("close");
531 	free(pack->privsep_child);
532 	pack->privsep_child = NULL;
533 	return err;
534 }
535 
536 const struct got_error *
537 got_pack_close(struct got_pack *pack)
538 {
539 	const struct got_error *err = NULL;
540 
541 	err = got_pack_stop_privsep_child(pack);
542 	if (pack->map && munmap(pack->map, pack->filesize) == -1 && !err)
543 		err = got_error_from_errno("munmap");
544 	if (pack->fd != -1 && close(pack->fd) != 0 && err == NULL)
545 		err = got_error_from_errno("close");
546 	pack->fd = -1;
547 	free(pack->path_packfile);
548 	pack->path_packfile = NULL;
549 	pack->filesize = 0;
550 	if (pack->delta_cache) {
551 		got_delta_cache_free(pack->delta_cache);
552 		pack->delta_cache = NULL;
553 	}
554 
555 	return err;
556 }
557 
558 static const struct got_error *
559 parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len,
560     struct got_pack *pack, off_t offset)
561 {
562 	uint8_t t = 0;
563 	uint64_t s = 0;
564 	uint8_t sizeN;
565 	size_t mapoff = 0;
566 	int i = 0;
567 
568 	*len = 0;
569 
570 	if (offset >= pack->filesize)
571 		return got_error(GOT_ERR_PACK_OFFSET);
572 
573 	if (pack->map) {
574 		mapoff = (size_t)offset;
575 	} else {
576 		if (lseek(pack->fd, offset, SEEK_SET) == -1)
577 			return got_error_from_errno("lseek");
578 	}
579 
580 	do {
581 		/* We do not support size values which don't fit in 64 bit. */
582 		if (i > 9)
583 			return got_error(GOT_ERR_NO_SPACE);
584 
585 		if (pack->map) {
586 			sizeN = *(pack->map + mapoff);
587 			mapoff += sizeof(sizeN);
588 		} else {
589 			ssize_t n = read(pack->fd, &sizeN, sizeof(sizeN));
590 			if (n < 0)
591 				return got_error_from_errno("read");
592 			if (n != sizeof(sizeN))
593 				return got_error(GOT_ERR_BAD_PACKFILE);
594 		}
595 		*len += sizeof(sizeN);
596 
597 		if (i == 0) {
598 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
599 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
600 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
601 		} else {
602 			size_t shift = 4 + 7 * (i - 1);
603 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
604 		}
605 		i++;
606 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
607 
608 	*type = t;
609 	*size = s;
610 	return NULL;
611 }
612 
613 static const struct got_error *
614 open_plain_object(struct got_object **obj, struct got_object_id *id,
615     uint8_t type, off_t offset, size_t size, int idx)
616 {
617 	*obj = calloc(1, sizeof(**obj));
618 	if (*obj == NULL)
619 		return got_error_from_errno("calloc");
620 
621 	(*obj)->type = type;
622 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
623 	(*obj)->pack_idx = idx;
624 	(*obj)->hdrlen = 0;
625 	(*obj)->size = size;
626 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
627 	(*obj)->pack_offset = offset;
628 
629 	return NULL;
630 }
631 
632 static const struct got_error *
633 parse_negative_offset(int64_t *offset, size_t *len, struct got_pack *pack,
634     off_t delta_offset)
635 {
636 	int64_t o = 0;
637 	uint8_t offN;
638 	int i = 0;
639 
640 	*offset = 0;
641 	*len = 0;
642 
643 	do {
644 		/* We do not support offset values which don't fit in 64 bit. */
645 		if (i > 8)
646 			return got_error(GOT_ERR_NO_SPACE);
647 
648 		if (pack->map) {
649 			size_t mapoff;
650 			if (delta_offset >= pack->filesize)
651 				return got_error(GOT_ERR_PACK_OFFSET);
652 			mapoff = (size_t)delta_offset + *len;
653 			offN = *(pack->map + mapoff);
654 		} else {
655 			ssize_t n;
656 			n = read(pack->fd, &offN, sizeof(offN));
657 			if (n < 0)
658 				return got_error_from_errno("read");
659 			if (n != sizeof(offN))
660 				return got_error(GOT_ERR_BAD_PACKFILE);
661 		}
662 		*len += sizeof(offN);
663 
664 		if (i == 0)
665 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
666 		else {
667 			o++;
668 			o <<= 7;
669 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
670 		}
671 		i++;
672 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
673 
674 	*offset = o;
675 	return NULL;
676 }
677 
678 static const struct got_error *
679 parse_offset_delta(off_t *base_offset, size_t *len, struct got_pack *pack,
680     off_t offset, int tslen)
681 {
682 	const struct got_error *err;
683 	int64_t negoffset;
684 	size_t negofflen;
685 
686 	*len = 0;
687 
688 	err = parse_negative_offset(&negoffset, &negofflen, pack,
689 	    offset + tslen);
690 	if (err)
691 		return err;
692 
693 	/* Compute the base object's offset (must be in the same pack file). */
694 	*base_offset = (offset - negoffset);
695 	if (*base_offset <= 0)
696 		return got_error(GOT_ERR_BAD_PACKFILE);
697 
698 	*len = negofflen;
699 	return NULL;
700 }
701 
702 static const struct got_error *
703 resolve_delta_chain(struct got_delta_chain *, struct got_packidx *,
704     struct got_pack *, off_t, size_t, int, size_t, unsigned int);
705 
706 static const struct got_error *
707 read_delta_data(uint8_t **delta_buf, size_t *delta_len,
708     size_t delta_data_offset, struct got_pack *pack)
709 {
710 	const struct got_error *err = NULL;
711 
712 	if (pack->map) {
713 		if (delta_data_offset >= pack->filesize)
714 			return got_error(GOT_ERR_PACK_OFFSET);
715 		err = got_inflate_to_mem_mmap(delta_buf, delta_len, pack->map,
716 		    delta_data_offset, pack->filesize - delta_data_offset);
717 	} else {
718 		if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1)
719 			return got_error_from_errno("lseek");
720 		err = got_inflate_to_mem_fd(delta_buf, delta_len, pack->fd);
721 	}
722 	return err;
723 }
724 
725 static const struct got_error *
726 add_delta(struct got_delta_chain *deltas, off_t delta_offset, size_t tslen,
727     int delta_type, size_t delta_size, size_t delta_data_offset)
728 {
729 	struct got_delta *delta;
730 
731 	delta = got_delta_open(delta_offset, tslen, delta_type, delta_size,
732 	    delta_data_offset);
733 	if (delta == NULL)
734 		return got_error_from_errno("got_delta_open");
735 	/* delta is freed in got_object_close() */
736 	deltas->nentries++;
737 	SIMPLEQ_INSERT_HEAD(&deltas->entries, delta, entry);
738 	return NULL;
739 }
740 
741 static const struct got_error *
742 resolve_offset_delta(struct got_delta_chain *deltas,
743     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
744     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
745 
746 {
747 	const struct got_error *err;
748 	off_t base_offset;
749 	uint8_t base_type;
750 	uint64_t base_size;
751 	size_t base_tslen;
752 	off_t delta_data_offset;
753 	size_t consumed;
754 
755 	err = parse_offset_delta(&base_offset, &consumed, pack,
756 	    delta_offset, tslen);
757 	if (err)
758 		return err;
759 
760 	delta_data_offset = delta_offset + tslen + consumed;
761 	if (delta_data_offset >= pack->filesize)
762 		return got_error(GOT_ERR_PACK_OFFSET);
763 
764 	if (pack->map == NULL) {
765 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
766 		if (delta_data_offset == -1)
767 			return got_error_from_errno("lseek");
768 	}
769 
770 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
771 	    delta_data_offset);
772 	if (err)
773 		return err;
774 
775 	/* An offset delta must be in the same packfile. */
776 	if (base_offset >= pack->filesize)
777 		return got_error(GOT_ERR_PACK_OFFSET);
778 
779 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
780 	    pack, base_offset);
781 	if (err)
782 		return err;
783 
784 	return resolve_delta_chain(deltas, packidx, pack, base_offset,
785 	    base_tslen, base_type, base_size, recursion - 1);
786 }
787 
788 static const struct got_error *
789 resolve_ref_delta(struct got_delta_chain *deltas, struct got_packidx *packidx,
790     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
791     size_t delta_size, unsigned int recursion)
792 {
793 	const struct got_error *err;
794 	struct got_object_id id;
795 	int idx;
796 	off_t base_offset;
797 	uint8_t base_type;
798 	uint64_t base_size;
799 	size_t base_tslen;
800 	off_t delta_data_offset;
801 	uint8_t *delta_buf;
802 	size_t delta_len;
803 
804 	if (delta_offset + tslen >= pack->filesize)
805 		return got_error(GOT_ERR_PACK_OFFSET);
806 
807 	if (pack->map == NULL) {
808 	}
809 
810 	if (pack->map) {
811 		size_t mapoff = delta_offset + tslen;
812 		memcpy(&id, pack->map + mapoff, sizeof(id));
813 		mapoff += sizeof(id);
814 		delta_data_offset = (off_t)mapoff;
815 		err = got_inflate_to_mem_mmap(&delta_buf, &delta_len, pack->map,
816 		    mapoff, pack->filesize - mapoff);
817 		if (err)
818 			return err;
819 	} else {
820 		ssize_t n;
821 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
822 		if (delta_data_offset == -1)
823 			return got_error_from_errno("lseek");
824 		n = read(pack->fd, &id, sizeof(id));
825 		if (n < 0)
826 			return got_error_from_errno("read");
827 		if (n != sizeof(id))
828 			return got_error(GOT_ERR_BAD_PACKFILE);
829 		err = got_inflate_to_mem_fd(&delta_buf, &delta_len, pack->fd);
830 		if (err)
831 			return err;
832 	}
833 
834 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
835 	    delta_data_offset);
836 	if (err)
837 		return err;
838 
839 	/* Delta base must be in the same pack file. */
840 	idx = got_packidx_get_object_idx(packidx, &id);
841 	if (idx == -1)
842 		return got_error(GOT_ERR_BAD_PACKFILE);
843 
844 	base_offset = get_object_offset(packidx, idx);
845 	if (base_offset == (uint64_t)-1)
846 		return got_error(GOT_ERR_BAD_PACKIDX);
847 
848 	if (base_offset >= pack->filesize)
849 		return got_error(GOT_ERR_PACK_OFFSET);
850 
851 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
852 	    pack, base_offset);
853 	if (err)
854 		return err;
855 
856 	return resolve_delta_chain(deltas, packidx, pack, base_offset,
857 	    base_tslen, base_type, base_size, recursion - 1);
858 }
859 
860 static const struct got_error *
861 resolve_delta_chain(struct got_delta_chain *deltas, struct got_packidx *packidx,
862     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
863     size_t delta_size, unsigned int recursion)
864 {
865 	const struct got_error *err = NULL;
866 
867 	if (--recursion == 0)
868 		return got_error(GOT_ERR_RECURSION);
869 
870 	switch (delta_type) {
871 	case GOT_OBJ_TYPE_COMMIT:
872 	case GOT_OBJ_TYPE_TREE:
873 	case GOT_OBJ_TYPE_BLOB:
874 	case GOT_OBJ_TYPE_TAG:
875 		/* Plain types are the final delta base. Recursion ends. */
876 		err = add_delta(deltas, delta_offset, tslen, delta_type,
877 		    delta_size, 0);
878 		break;
879 	case GOT_OBJ_TYPE_OFFSET_DELTA:
880 		err = resolve_offset_delta(deltas, packidx, pack,
881 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
882 		break;
883 	case GOT_OBJ_TYPE_REF_DELTA:
884 		err = resolve_ref_delta(deltas, packidx, pack,
885 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
886 		break;
887 	default:
888 		return got_error(GOT_ERR_OBJ_TYPE);
889 	}
890 
891 	return err;
892 }
893 
894 static const struct got_error *
895 open_delta_object(struct got_object **obj, struct got_packidx *packidx,
896     struct got_pack *pack, struct got_object_id *id, off_t offset,
897     size_t tslen, int delta_type, size_t delta_size, int idx)
898 {
899 	const struct got_error *err = NULL;
900 	int resolved_type;
901 
902 	*obj = calloc(1, sizeof(**obj));
903 	if (*obj == NULL)
904 		return got_error_from_errno("calloc");
905 
906 	(*obj)->flags = 0;
907 	(*obj)->hdrlen = 0;
908 	(*obj)->size = 0; /* Not known because deltas aren't applied yet. */
909 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
910 	(*obj)->pack_offset = offset + tslen;
911 
912 	SIMPLEQ_INIT(&(*obj)->deltas.entries);
913 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
914 	(*obj)->flags |= GOT_OBJ_FLAG_PACKED;
915 	(*obj)->pack_idx = idx;
916 
917 	err = resolve_delta_chain(&(*obj)->deltas, packidx, pack, offset,
918 	    tslen, delta_type, delta_size, GOT_DELTA_CHAIN_RECURSION_MAX);
919 	if (err)
920 		goto done;
921 
922 	err = got_delta_chain_get_base_type(&resolved_type, &(*obj)->deltas);
923 	if (err)
924 		goto done;
925 	(*obj)->type = resolved_type;
926 done:
927 	if (err) {
928 		got_object_close(*obj);
929 		*obj = NULL;
930 	}
931 	return err;
932 }
933 
934 const struct got_error *
935 got_packfile_open_object(struct got_object **obj, struct got_pack *pack,
936     struct got_packidx *packidx, int idx, struct got_object_id *id)
937 {
938 	const struct got_error *err = NULL;
939 	off_t offset;
940 	uint8_t type;
941 	uint64_t size;
942 	size_t tslen;
943 
944 	*obj = NULL;
945 
946 	offset = get_object_offset(packidx, idx);
947 	if (offset == (uint64_t)-1)
948 		return got_error(GOT_ERR_BAD_PACKIDX);
949 
950 	err = parse_object_type_and_size(&type, &size, &tslen, pack, offset);
951 	if (err)
952 		return err;
953 
954 	switch (type) {
955 	case GOT_OBJ_TYPE_COMMIT:
956 	case GOT_OBJ_TYPE_TREE:
957 	case GOT_OBJ_TYPE_BLOB:
958 	case GOT_OBJ_TYPE_TAG:
959 		err = open_plain_object(obj, id, type, offset + tslen,
960 		    size, idx);
961 		break;
962 	case GOT_OBJ_TYPE_OFFSET_DELTA:
963 	case GOT_OBJ_TYPE_REF_DELTA:
964 		err = open_delta_object(obj, packidx, pack, id, offset,
965 		    tslen, type, size, idx);
966 		break;
967 	default:
968 		err = got_error(GOT_ERR_OBJ_TYPE);
969 		break;
970 	}
971 
972 	return err;
973 }
974 
975 static const struct got_error *
976 get_delta_chain_max_size(uint64_t *max_size, struct got_delta_chain *deltas,
977     struct got_pack *pack)
978 {
979 	struct got_delta *delta;
980 	uint64_t base_size = 0, result_size = 0;
981 
982 	*max_size = 0;
983 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
984 		/* Plain object types are the delta base. */
985 		if (delta->type != GOT_OBJ_TYPE_COMMIT &&
986 		    delta->type != GOT_OBJ_TYPE_TREE &&
987 		    delta->type != GOT_OBJ_TYPE_BLOB &&
988 		    delta->type != GOT_OBJ_TYPE_TAG) {
989 			const struct got_error *err;
990 			uint8_t *delta_buf;
991 			size_t delta_len;
992 			int cached = 1;
993 
994 			got_delta_cache_get(&delta_buf, &delta_len,
995 			    pack->delta_cache, delta->data_offset);
996 			if (delta_buf == NULL) {
997 				cached = 0;
998 				err = read_delta_data(&delta_buf, &delta_len,
999 				    delta->data_offset, pack);
1000 				if (err)
1001 					return err;
1002 				err = got_delta_cache_add(pack->delta_cache,
1003 				    delta->data_offset, delta_buf, delta_len);
1004 				if (err == NULL)
1005 					cached = 1;
1006 				else if (err->code != GOT_ERR_NO_SPACE) {
1007 					free(delta_buf);
1008 					return err;
1009 				}
1010 			}
1011 			err = got_delta_get_sizes(&base_size, &result_size,
1012 			    delta_buf, delta_len);
1013 			if (!cached)
1014 				free(delta_buf);
1015 			if (err)
1016 				return err;
1017 		} else
1018 			base_size = delta->size;
1019 		if (base_size > *max_size)
1020 			*max_size = base_size;
1021 		if (result_size > *max_size)
1022 			*max_size = result_size;
1023 	}
1024 
1025 	return NULL;
1026 }
1027 
1028 const struct got_error *
1029 got_pack_get_max_delta_object_size(uint64_t *size, struct got_object *obj,
1030     struct got_pack *pack)
1031 {
1032 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0)
1033 		return got_error(GOT_ERR_OBJ_TYPE);
1034 
1035 	return get_delta_chain_max_size(size, &obj->deltas, pack);
1036 }
1037 
1038 static const struct got_error *
1039 dump_delta_chain_to_file(size_t *result_size, struct got_delta_chain *deltas,
1040     struct got_pack *pack, FILE *outfile, FILE *base_file, FILE *accum_file)
1041 {
1042 	const struct got_error *err = NULL;
1043 	struct got_delta *delta;
1044 	uint8_t *base_buf = NULL, *accum_buf = NULL, *delta_buf;
1045 	size_t base_bufsz = 0, accum_size = 0, delta_len;
1046 	uint64_t max_size;
1047 	int n = 0;
1048 
1049 	*result_size = 0;
1050 
1051 	if (SIMPLEQ_EMPTY(&deltas->entries))
1052 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1053 
1054 	/* We process small enough files entirely in memory for speed. */
1055 	err = get_delta_chain_max_size(&max_size, deltas, pack);
1056 	if (err)
1057 		return err;
1058 	if (max_size < GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
1059 		accum_buf = malloc(max_size);
1060 		if (accum_buf == NULL)
1061 			return got_error_from_errno("malloc");
1062 		base_file = NULL;
1063 		accum_file = NULL;
1064 	}
1065 
1066 	/* Deltas are ordered in ascending order. */
1067 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1068 		int cached = 1;
1069 		if (n == 0) {
1070 			size_t mapoff;
1071 			off_t delta_data_offset;
1072 
1073 			/* Plain object types are the delta base. */
1074 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1075 			    delta->type != GOT_OBJ_TYPE_TREE &&
1076 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1077 			    delta->type != GOT_OBJ_TYPE_TAG) {
1078 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1079 				goto done;
1080 			}
1081 
1082 			delta_data_offset = delta->offset + delta->tslen;
1083 			if (delta_data_offset >= pack->filesize) {
1084 				err = got_error(GOT_ERR_PACK_OFFSET);
1085 				goto done;
1086 			}
1087 			if (pack->map == NULL) {
1088 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1089 				    == -1) {
1090 					err = got_error_from_errno("lseek");
1091 					goto done;
1092 				}
1093 			}
1094 			if (base_file) {
1095 				if (pack->map) {
1096 					mapoff = (size_t)delta_data_offset;
1097 					err = got_inflate_to_file_mmap(
1098 					    &base_bufsz, pack->map, mapoff,
1099 					    pack->filesize - mapoff, base_file);
1100 				} else
1101 					err = got_inflate_to_file_fd(
1102 					    &base_bufsz, pack->fd, base_file);
1103 			} else {
1104 				if (pack->map) {
1105 					mapoff = (size_t)delta_data_offset;
1106 					err = got_inflate_to_mem_mmap(&base_buf,
1107 					    &base_bufsz, pack->map, mapoff,
1108 					    pack->filesize - mapoff);
1109 				} else
1110 					err = got_inflate_to_mem_fd(&base_buf,
1111 					    &base_bufsz, pack->fd);
1112 			}
1113 			if (err)
1114 				goto done;
1115 			n++;
1116 			if (base_file)
1117 				rewind(base_file);
1118 			continue;
1119 		}
1120 
1121 		got_delta_cache_get(&delta_buf, &delta_len,
1122 		    pack->delta_cache, delta->data_offset);
1123 		if (delta_buf == NULL) {
1124 			cached = 0;
1125 			err = read_delta_data(&delta_buf, &delta_len,
1126 			    delta->data_offset, pack);
1127 			if (err)
1128 				goto done;
1129 			err = got_delta_cache_add(pack->delta_cache,
1130 			    delta->data_offset, delta_buf, delta_len);
1131 			if (err == NULL)
1132 				cached = 1;
1133 			else if (err->code != GOT_ERR_NO_SPACE) {
1134 				free(delta_buf);
1135 				goto done;
1136 			}
1137 		}
1138 		if (base_buf) {
1139 			err = got_delta_apply_in_mem(base_buf, base_bufsz,
1140 			    delta_buf, delta_len, accum_buf,
1141 			    &accum_size, max_size);
1142 			n++;
1143 		} else {
1144 			err = got_delta_apply(base_file, delta_buf,
1145 			    delta_len,
1146 			    /* Final delta application writes to output file. */
1147 			    ++n < deltas->nentries ? accum_file : outfile,
1148 			    &accum_size);
1149 		}
1150 		if (!cached)
1151 			free(delta_buf);
1152 		if (err)
1153 			goto done;
1154 
1155 		if (n < deltas->nentries) {
1156 			/* Accumulated delta becomes the new base. */
1157 			if (base_buf) {
1158 				uint8_t *tmp = accum_buf;
1159 				/*
1160 				 * Base buffer switches roles with accumulation
1161 				 * buffer. Ensure it can hold the largest
1162 				 * result in the delta chain. The initial
1163 				 * allocation might have been smaller.
1164 				 */
1165 				if (base_bufsz < max_size) {
1166 					uint8_t *p;
1167 					p = reallocarray(base_buf, 1, max_size);
1168 					if (p == NULL) {
1169 						err = got_error_from_errno(
1170 						    "reallocarray");
1171 						goto done;
1172 					}
1173 					base_buf = p;
1174 					base_bufsz = max_size;
1175 				}
1176 				accum_buf = base_buf;
1177 				base_buf = tmp;
1178 			} else {
1179 				FILE *tmp = accum_file;
1180 				accum_file = base_file;
1181 				base_file = tmp;
1182 				rewind(base_file);
1183 				rewind(accum_file);
1184 			}
1185 		}
1186 	}
1187 
1188 done:
1189 	free(base_buf);
1190 	if (accum_buf) {
1191 		size_t len = fwrite(accum_buf, 1, accum_size, outfile);
1192 		free(accum_buf);
1193 		if (len != accum_size)
1194 			err = got_ferror(outfile, GOT_ERR_IO);
1195 	}
1196 	rewind(outfile);
1197 	if (err == NULL)
1198 		*result_size = accum_size;
1199 	return err;
1200 }
1201 
1202 static const struct got_error *
1203 dump_delta_chain_to_mem(uint8_t **outbuf, size_t *outlen,
1204     struct got_delta_chain *deltas, struct got_pack *pack)
1205 {
1206 	const struct got_error *err = NULL;
1207 	struct got_delta *delta;
1208 	uint8_t *base_buf = NULL, *accum_buf = NULL, *delta_buf;
1209 	size_t base_bufsz = 0, accum_size = 0, delta_len;
1210 	uint64_t max_size;
1211 	int n = 0;
1212 
1213 	*outbuf = NULL;
1214 	*outlen = 0;
1215 
1216 	if (SIMPLEQ_EMPTY(&deltas->entries))
1217 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1218 
1219 	err = get_delta_chain_max_size(&max_size, deltas, pack);
1220 	if (err)
1221 		return err;
1222 	accum_buf = malloc(max_size);
1223 	if (accum_buf == NULL)
1224 		return got_error_from_errno("malloc");
1225 
1226 	/* Deltas are ordered in ascending order. */
1227 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1228 		int cached = 1;
1229 		if (n == 0) {
1230 			size_t delta_data_offset;
1231 
1232 			/* Plain object types are the delta base. */
1233 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1234 			    delta->type != GOT_OBJ_TYPE_TREE &&
1235 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1236 			    delta->type != GOT_OBJ_TYPE_TAG) {
1237 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1238 				goto done;
1239 			}
1240 
1241 			delta_data_offset = delta->offset + delta->tslen;
1242 			if (delta_data_offset >= pack->filesize) {
1243 				err = got_error(GOT_ERR_PACK_OFFSET);
1244 				goto done;
1245 			}
1246 			if (pack->map) {
1247 				size_t mapoff = (size_t)delta_data_offset;
1248 				err = got_inflate_to_mem_mmap(&base_buf,
1249 				    &base_bufsz, pack->map, mapoff,
1250 				    pack->filesize - mapoff);
1251 			} else {
1252 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1253 				    == -1) {
1254 					err = got_error_from_errno("lseek");
1255 					goto done;
1256 				}
1257 				err = got_inflate_to_mem_fd(&base_buf,
1258 				    &base_bufsz, pack->fd);
1259 			}
1260 			if (err)
1261 				goto done;
1262 			n++;
1263 			continue;
1264 		}
1265 
1266 		got_delta_cache_get(&delta_buf, &delta_len,
1267 		    pack->delta_cache, delta->data_offset);
1268 		if (delta_buf == NULL) {
1269 			cached = 0;
1270 			err = read_delta_data(&delta_buf, &delta_len,
1271 			    delta->data_offset, pack);
1272 			if (err)
1273 				goto done;
1274 			err = got_delta_cache_add(pack->delta_cache,
1275 			    delta->data_offset, delta_buf, delta_len);
1276 			if (err == NULL)
1277 				cached = 1;
1278 			else if (err->code != GOT_ERR_NO_SPACE) {
1279 				free(delta_buf);
1280 				goto done;
1281 			}
1282 		}
1283 		err = got_delta_apply_in_mem(base_buf, base_bufsz,
1284 		    delta_buf, delta_len, accum_buf,
1285 		    &accum_size, max_size);
1286 		if (!cached)
1287 			free(delta_buf);
1288 		n++;
1289 		if (err)
1290 			goto done;
1291 
1292 		if (n < deltas->nentries) {
1293 			/* Accumulated delta becomes the new base. */
1294 			uint8_t *tmp = accum_buf;
1295 			/*
1296 			 * Base buffer switches roles with accumulation buffer.
1297 			 * Ensure it can hold the largest result in the delta
1298 			 * chain. Initial allocation might have been smaller.
1299 			 */
1300 			if (base_bufsz < max_size) {
1301 				uint8_t *p;
1302 				p = reallocarray(base_buf, 1, max_size);
1303 				if (p == NULL) {
1304 					err = got_error_from_errno(
1305 					    "reallocarray");
1306 					goto done;
1307 				}
1308 				base_buf = p;
1309 				base_bufsz = max_size;
1310 			}
1311 			accum_buf = base_buf;
1312 			base_buf = tmp;
1313 		}
1314 	}
1315 
1316 done:
1317 	free(base_buf);
1318 	if (err) {
1319 		free(accum_buf);
1320 		*outbuf = NULL;
1321 		*outlen = 0;
1322 	} else {
1323 		*outbuf = accum_buf;
1324 		*outlen = accum_size;
1325 	}
1326 	return err;
1327 }
1328 
1329 const struct got_error *
1330 got_packfile_extract_object(struct got_pack *pack, struct got_object *obj,
1331     FILE *outfile, FILE *base_file, FILE *accum_file)
1332 {
1333 	const struct got_error *err = NULL;
1334 
1335 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1336 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1337 
1338 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1339 		if (obj->pack_offset >= pack->filesize)
1340 			return got_error(GOT_ERR_PACK_OFFSET);
1341 
1342 		if (pack->map) {
1343 			size_t mapoff = (size_t)obj->pack_offset;
1344 			err = got_inflate_to_file_mmap(&obj->size, pack->map,
1345 			    mapoff, pack->filesize - mapoff, outfile);
1346 		} else {
1347 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1348 				return got_error_from_errno("lseek");
1349 			err = got_inflate_to_file_fd(&obj->size, pack->fd,
1350 			    outfile);
1351 		}
1352 	} else
1353 		err = dump_delta_chain_to_file(&obj->size, &obj->deltas, pack,
1354 		    outfile, base_file, accum_file);
1355 
1356 	return err;
1357 }
1358 
1359 const struct got_error *
1360 got_packfile_extract_object_to_mem(uint8_t **buf, size_t *len,
1361     struct got_object *obj, struct got_pack *pack)
1362 {
1363 	const struct got_error *err = NULL;
1364 
1365 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1366 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1367 
1368 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1369 		if (obj->pack_offset >= pack->filesize)
1370 			return got_error(GOT_ERR_PACK_OFFSET);
1371 		if (pack->map) {
1372 			size_t mapoff = (size_t)obj->pack_offset;
1373 			err = got_inflate_to_mem_mmap(buf, len, pack->map,
1374 			    mapoff, pack->filesize - mapoff);
1375 		} else {
1376 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1377 				return got_error_from_errno("lseek");
1378 			err = got_inflate_to_mem_fd(buf, len, pack->fd);
1379 		}
1380 	} else
1381 		err = dump_delta_chain_to_mem(buf, len, &obj->deltas, pack);
1382 
1383 	return err;
1384 }