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Date:: Sun Mar 15 16:15:58 2020 UTC
Message:: remove unneeded memory allocations from ref delta parser which were leaking
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1 /*
2  * Copyright (c) 2018, 2019, 2020 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_sha1(struct got_packidx *packidx, uint8_t *sha1)
434 {
435 	u_int8_t id0 = 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(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 int
461 got_packidx_get_object_idx(struct got_packidx *packidx, struct got_object_id *id)
462 {
463 	return got_packidx_get_object_idx_sha1(packidx, id->sha1);
464 }
465 
466 const struct got_error *
467 got_packidx_match_id_str_prefix(struct got_object_id_queue *matched_ids,
468     struct got_packidx *packidx, const char *id_str_prefix)
469 {
470 	const struct got_error *err = NULL;
471 	u_int8_t id0;
472 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
473 	char hex[3];
474 	size_t prefix_len = strlen(id_str_prefix);
475 	struct got_packidx_object_id *oid;
476 	int i;
477 
478 	SIMPLEQ_INIT(matched_ids);
479 
480 	if (prefix_len < 2)
481 		return got_error_path(id_str_prefix, GOT_ERR_BAD_OBJ_ID_STR);
482 
483 	hex[0] = id_str_prefix[0];
484 	hex[1] = id_str_prefix[1];
485 	hex[2] = '\0';
486 	if (!got_parse_xdigit(&id0, hex))
487 		return got_error_path(id_str_prefix, GOT_ERR_BAD_OBJ_ID_STR);
488 
489 	i = betoh32(packidx->hdr.fanout_table[id0 - 1]);
490 	if (i == 0)
491 		return NULL;
492 
493 	oid = &packidx->hdr.sorted_ids[i];
494 	while (i < totobj && oid->sha1[0] == id0) {
495 		char id_str[SHA1_DIGEST_STRING_LENGTH];
496 		struct got_object_qid *qid;
497 		int cmp;
498 
499 		if (!got_sha1_digest_to_str(oid->sha1, id_str, sizeof(id_str)))
500 		        return got_error(GOT_ERR_NO_SPACE);
501 
502 		cmp = strncmp(id_str, id_str_prefix, prefix_len);
503 		if (cmp < 0) {
504 			oid = &packidx->hdr.sorted_ids[++i];
505 			continue;
506 		} else if (cmp > 0)
507 			break;
508 
509 		err = got_object_qid_alloc_partial(&qid);
510 		if (err)
511 			break;
512 		memcpy(qid->id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
513 		SIMPLEQ_INSERT_TAIL(matched_ids, qid, entry);
514 
515 		oid = &packidx->hdr.sorted_ids[++i];
516 	}
517 
518 	if (err)
519 		got_object_id_queue_free(matched_ids);
520 	return err;
521 }
522 
523 const struct got_error *
524 got_pack_stop_privsep_child(struct got_pack *pack)
525 {
526 	const struct got_error *err = NULL;
527 
528 	if (pack->privsep_child == NULL)
529 		return NULL;
530 
531 	err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
532 	if (err)
533 		return err;
534 	err = got_privsep_wait_for_child(pack->privsep_child->pid);
535 	if (close(pack->privsep_child->imsg_fd) != 0 && err == NULL)
536 		err = got_error_from_errno("close");
537 	free(pack->privsep_child);
538 	pack->privsep_child = NULL;
539 	return err;
540 }
541 
542 const struct got_error *
543 got_pack_close(struct got_pack *pack)
544 {
545 	const struct got_error *err = NULL;
546 
547 	err = got_pack_stop_privsep_child(pack);
548 	if (pack->map && munmap(pack->map, pack->filesize) == -1 && !err)
549 		err = got_error_from_errno("munmap");
550 	if (pack->fd != -1 && close(pack->fd) != 0 && err == NULL)
551 		err = got_error_from_errno("close");
552 	pack->fd = -1;
553 	free(pack->path_packfile);
554 	pack->path_packfile = NULL;
555 	pack->filesize = 0;
556 	if (pack->delta_cache) {
557 		got_delta_cache_free(pack->delta_cache);
558 		pack->delta_cache = NULL;
559 	}
560 
561 	return err;
562 }
563 
564 static const struct got_error *
565 parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len,
566     struct got_pack *pack, off_t offset)
567 {
568 	uint8_t t = 0;
569 	uint64_t s = 0;
570 	uint8_t sizeN;
571 	size_t mapoff = 0;
572 	int i = 0;
573 
574 	*len = 0;
575 
576 	if (offset >= pack->filesize)
577 		return got_error(GOT_ERR_PACK_OFFSET);
578 
579 	if (pack->map) {
580 		mapoff = (size_t)offset;
581 	} else {
582 		if (lseek(pack->fd, offset, SEEK_SET) == -1)
583 			return got_error_from_errno("lseek");
584 	}
585 
586 	do {
587 		/* We do not support size values which don't fit in 64 bit. */
588 		if (i > 9)
589 			return got_error(GOT_ERR_NO_SPACE);
590 
591 		if (pack->map) {
592 			sizeN = *(pack->map + mapoff);
593 			mapoff += sizeof(sizeN);
594 		} else {
595 			ssize_t n = read(pack->fd, &sizeN, sizeof(sizeN));
596 			if (n < 0)
597 				return got_error_from_errno("read");
598 			if (n != sizeof(sizeN))
599 				return got_error(GOT_ERR_BAD_PACKFILE);
600 		}
601 		*len += sizeof(sizeN);
602 
603 		if (i == 0) {
604 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
605 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
606 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
607 		} else {
608 			size_t shift = 4 + 7 * (i - 1);
609 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
610 		}
611 		i++;
612 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
613 
614 	*type = t;
615 	*size = s;
616 	return NULL;
617 }
618 
619 static const struct got_error *
620 open_plain_object(struct got_object **obj, struct got_object_id *id,
621     uint8_t type, off_t offset, size_t size, int idx)
622 {
623 	*obj = calloc(1, sizeof(**obj));
624 	if (*obj == NULL)
625 		return got_error_from_errno("calloc");
626 
627 	(*obj)->type = type;
628 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
629 	(*obj)->pack_idx = idx;
630 	(*obj)->hdrlen = 0;
631 	(*obj)->size = size;
632 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
633 	(*obj)->pack_offset = offset;
634 
635 	return NULL;
636 }
637 
638 static const struct got_error *
639 parse_negative_offset(int64_t *offset, size_t *len, struct got_pack *pack,
640     off_t delta_offset)
641 {
642 	int64_t o = 0;
643 	uint8_t offN;
644 	int i = 0;
645 
646 	*offset = 0;
647 	*len = 0;
648 
649 	do {
650 		/* We do not support offset values which don't fit in 64 bit. */
651 		if (i > 8)
652 			return got_error(GOT_ERR_NO_SPACE);
653 
654 		if (pack->map) {
655 			size_t mapoff;
656 			if (delta_offset >= pack->filesize)
657 				return got_error(GOT_ERR_PACK_OFFSET);
658 			mapoff = (size_t)delta_offset + *len;
659 			offN = *(pack->map + mapoff);
660 		} else {
661 			ssize_t n;
662 			n = read(pack->fd, &offN, sizeof(offN));
663 			if (n < 0)
664 				return got_error_from_errno("read");
665 			if (n != sizeof(offN))
666 				return got_error(GOT_ERR_BAD_PACKFILE);
667 		}
668 		*len += sizeof(offN);
669 
670 		if (i == 0)
671 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
672 		else {
673 			o++;
674 			o <<= 7;
675 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
676 		}
677 		i++;
678 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
679 
680 	*offset = o;
681 	return NULL;
682 }
683 
684 static const struct got_error *
685 parse_offset_delta(off_t *base_offset, size_t *len, struct got_pack *pack,
686     off_t offset, int tslen)
687 {
688 	const struct got_error *err;
689 	int64_t negoffset;
690 	size_t negofflen;
691 
692 	*len = 0;
693 
694 	err = parse_negative_offset(&negoffset, &negofflen, pack,
695 	    offset + tslen);
696 	if (err)
697 		return err;
698 
699 	/* Compute the base object's offset (must be in the same pack file). */
700 	*base_offset = (offset - negoffset);
701 	if (*base_offset <= 0)
702 		return got_error(GOT_ERR_BAD_PACKFILE);
703 
704 	*len = negofflen;
705 	return NULL;
706 }
707 
708 static const struct got_error *
709 resolve_delta_chain(struct got_delta_chain *, struct got_packidx *,
710     struct got_pack *, off_t, size_t, int, size_t, unsigned int);
711 
712 static const struct got_error *
713 read_delta_data(uint8_t **delta_buf, size_t *delta_len,
714     size_t delta_data_offset, struct got_pack *pack)
715 {
716 	const struct got_error *err = NULL;
717 
718 	if (pack->map) {
719 		if (delta_data_offset >= pack->filesize)
720 			return got_error(GOT_ERR_PACK_OFFSET);
721 		err = got_inflate_to_mem_mmap(delta_buf, delta_len, pack->map,
722 		    delta_data_offset, pack->filesize - delta_data_offset);
723 	} else {
724 		if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1)
725 			return got_error_from_errno("lseek");
726 		err = got_inflate_to_mem_fd(delta_buf, delta_len, pack->fd);
727 	}
728 	return err;
729 }
730 
731 static const struct got_error *
732 add_delta(struct got_delta_chain *deltas, off_t delta_offset, size_t tslen,
733     int delta_type, size_t delta_size, size_t delta_data_offset)
734 {
735 	struct got_delta *delta;
736 
737 	delta = got_delta_open(delta_offset, tslen, delta_type, delta_size,
738 	    delta_data_offset);
739 	if (delta == NULL)
740 		return got_error_from_errno("got_delta_open");
741 	/* delta is freed in got_object_close() */
742 	deltas->nentries++;
743 	SIMPLEQ_INSERT_HEAD(&deltas->entries, delta, entry);
744 	return NULL;
745 }
746 
747 static const struct got_error *
748 resolve_offset_delta(struct got_delta_chain *deltas,
749     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
750     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
751 
752 {
753 	const struct got_error *err;
754 	off_t base_offset;
755 	uint8_t base_type;
756 	uint64_t base_size;
757 	size_t base_tslen;
758 	off_t delta_data_offset;
759 	size_t consumed;
760 
761 	err = parse_offset_delta(&base_offset, &consumed, pack,
762 	    delta_offset, tslen);
763 	if (err)
764 		return err;
765 
766 	delta_data_offset = delta_offset + tslen + consumed;
767 	if (delta_data_offset >= pack->filesize)
768 		return got_error(GOT_ERR_PACK_OFFSET);
769 
770 	if (pack->map == NULL) {
771 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
772 		if (delta_data_offset == -1)
773 			return got_error_from_errno("lseek");
774 	}
775 
776 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
777 	    delta_data_offset);
778 	if (err)
779 		return err;
780 
781 	/* An offset delta must be in the same packfile. */
782 	if (base_offset >= pack->filesize)
783 		return got_error(GOT_ERR_PACK_OFFSET);
784 
785 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
786 	    pack, base_offset);
787 	if (err)
788 		return err;
789 
790 	return resolve_delta_chain(deltas, packidx, pack, base_offset,
791 	    base_tslen, base_type, base_size, recursion - 1);
792 }
793 
794 static const struct got_error *
795 resolve_ref_delta(struct got_delta_chain *deltas, struct got_packidx *packidx,
796     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
797     size_t delta_size, unsigned int recursion)
798 {
799 	const struct got_error *err;
800 	struct got_object_id id;
801 	int idx;
802 	off_t base_offset;
803 	uint8_t base_type;
804 	uint64_t base_size;
805 	size_t base_tslen;
806 	off_t delta_data_offset;
807 
808 	if (delta_offset + tslen >= pack->filesize)
809 		return got_error(GOT_ERR_PACK_OFFSET);
810 
811 	if (pack->map) {
812 		size_t mapoff = delta_offset + tslen;
813 		memcpy(&id, pack->map + mapoff, sizeof(id));
814 		mapoff += sizeof(id);
815 		delta_data_offset = (off_t)mapoff;
816 	} else {
817 		ssize_t n;
818 		n = read(pack->fd, &id, sizeof(id));
819 		if (n < 0)
820 			return got_error_from_errno("read");
821 		if (n != sizeof(id))
822 			return got_error(GOT_ERR_BAD_PACKFILE);
823 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
824 		if (delta_data_offset == -1)
825 			return got_error_from_errno("lseek");
826 	}
827 
828 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
829 	    delta_data_offset);
830 	if (err)
831 		return err;
832 
833 	/* Delta base must be in the same pack file. */
834 	idx = got_packidx_get_object_idx(packidx, &id);
835 	if (idx == -1)
836 		return got_error(GOT_ERR_BAD_PACKFILE);
837 
838 	base_offset = get_object_offset(packidx, idx);
839 	if (base_offset == (uint64_t)-1)
840 		return got_error(GOT_ERR_BAD_PACKIDX);
841 
842 	if (base_offset >= pack->filesize)
843 		return got_error(GOT_ERR_PACK_OFFSET);
844 
845 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
846 	    pack, base_offset);
847 	if (err)
848 		return err;
849 
850 	return resolve_delta_chain(deltas, packidx, pack, base_offset,
851 	    base_tslen, base_type, base_size, recursion - 1);
852 }
853 
854 static const struct got_error *
855 resolve_delta_chain(struct got_delta_chain *deltas, struct got_packidx *packidx,
856     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
857     size_t delta_size, unsigned int recursion)
858 {
859 	const struct got_error *err = NULL;
860 
861 	if (--recursion == 0)
862 		return got_error(GOT_ERR_RECURSION);
863 
864 	switch (delta_type) {
865 	case GOT_OBJ_TYPE_COMMIT:
866 	case GOT_OBJ_TYPE_TREE:
867 	case GOT_OBJ_TYPE_BLOB:
868 	case GOT_OBJ_TYPE_TAG:
869 		/* Plain types are the final delta base. Recursion ends. */
870 		err = add_delta(deltas, delta_offset, tslen, delta_type,
871 		    delta_size, 0);
872 		break;
873 	case GOT_OBJ_TYPE_OFFSET_DELTA:
874 		err = resolve_offset_delta(deltas, packidx, pack,
875 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
876 		break;
877 	case GOT_OBJ_TYPE_REF_DELTA:
878 		err = resolve_ref_delta(deltas, packidx, pack,
879 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
880 		break;
881 	default:
882 		return got_error(GOT_ERR_OBJ_TYPE);
883 	}
884 
885 	return err;
886 }
887 
888 static const struct got_error *
889 open_delta_object(struct got_object **obj, struct got_packidx *packidx,
890     struct got_pack *pack, struct got_object_id *id, off_t offset,
891     size_t tslen, int delta_type, size_t delta_size, int idx)
892 {
893 	const struct got_error *err = NULL;
894 	int resolved_type;
895 
896 	*obj = calloc(1, sizeof(**obj));
897 	if (*obj == NULL)
898 		return got_error_from_errno("calloc");
899 
900 	(*obj)->flags = 0;
901 	(*obj)->hdrlen = 0;
902 	(*obj)->size = 0; /* Not known because deltas aren't applied yet. */
903 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
904 	(*obj)->pack_offset = offset + tslen;
905 
906 	SIMPLEQ_INIT(&(*obj)->deltas.entries);
907 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
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, id, type, offset + tslen,
954 		    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     struct got_pack *pack)
972 {
973 	struct got_delta *delta;
974 	uint64_t base_size = 0, result_size = 0;
975 
976 	*max_size = 0;
977 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
978 		/* Plain object types are the delta base. */
979 		if (delta->type != GOT_OBJ_TYPE_COMMIT &&
980 		    delta->type != GOT_OBJ_TYPE_TREE &&
981 		    delta->type != GOT_OBJ_TYPE_BLOB &&
982 		    delta->type != GOT_OBJ_TYPE_TAG) {
983 			const struct got_error *err;
984 			uint8_t *delta_buf;
985 			size_t delta_len;
986 			int cached = 1;
987 
988 			got_delta_cache_get(&delta_buf, &delta_len,
989 			    pack->delta_cache, delta->data_offset);
990 			if (delta_buf == NULL) {
991 				cached = 0;
992 				err = read_delta_data(&delta_buf, &delta_len,
993 				    delta->data_offset, pack);
994 				if (err)
995 					return err;
996 				err = got_delta_cache_add(pack->delta_cache,
997 				    delta->data_offset, delta_buf, delta_len);
998 				if (err == NULL)
999 					cached = 1;
1000 				else if (err->code != GOT_ERR_NO_SPACE) {
1001 					free(delta_buf);
1002 					return err;
1003 				}
1004 			}
1005 			err = got_delta_get_sizes(&base_size, &result_size,
1006 			    delta_buf, delta_len);
1007 			if (!cached)
1008 				free(delta_buf);
1009 			if (err)
1010 				return err;
1011 		} else
1012 			base_size = delta->size;
1013 		if (base_size > *max_size)
1014 			*max_size = base_size;
1015 		if (result_size > *max_size)
1016 			*max_size = result_size;
1017 	}
1018 
1019 	return NULL;
1020 }
1021 
1022 const struct got_error *
1023 got_pack_get_max_delta_object_size(uint64_t *size, struct got_object *obj,
1024     struct got_pack *pack)
1025 {
1026 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0)
1027 		return got_error(GOT_ERR_OBJ_TYPE);
1028 
1029 	return get_delta_chain_max_size(size, &obj->deltas, pack);
1030 }
1031 
1032 static const struct got_error *
1033 dump_delta_chain_to_file(size_t *result_size, struct got_delta_chain *deltas,
1034     struct got_pack *pack, FILE *outfile, FILE *base_file, FILE *accum_file)
1035 {
1036 	const struct got_error *err = NULL;
1037 	struct got_delta *delta;
1038 	uint8_t *base_buf = NULL, *accum_buf = NULL, *delta_buf;
1039 	size_t base_bufsz = 0, accum_size = 0, delta_len;
1040 	uint64_t max_size;
1041 	int n = 0;
1042 
1043 	*result_size = 0;
1044 
1045 	if (SIMPLEQ_EMPTY(&deltas->entries))
1046 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1047 
1048 	/* We process small enough files entirely in memory for speed. */
1049 	err = get_delta_chain_max_size(&max_size, deltas, pack);
1050 	if (err)
1051 		return err;
1052 	if (max_size < GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
1053 		accum_buf = malloc(max_size);
1054 		if (accum_buf == NULL)
1055 			return got_error_from_errno("malloc");
1056 		base_file = NULL;
1057 		accum_file = NULL;
1058 	}
1059 
1060 	/* Deltas are ordered in ascending order. */
1061 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1062 		int cached = 1;
1063 		if (n == 0) {
1064 			size_t mapoff;
1065 			off_t delta_data_offset;
1066 
1067 			/* Plain object types are the delta base. */
1068 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1069 			    delta->type != GOT_OBJ_TYPE_TREE &&
1070 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1071 			    delta->type != GOT_OBJ_TYPE_TAG) {
1072 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1073 				goto done;
1074 			}
1075 
1076 			delta_data_offset = delta->offset + delta->tslen;
1077 			if (delta_data_offset >= pack->filesize) {
1078 				err = got_error(GOT_ERR_PACK_OFFSET);
1079 				goto done;
1080 			}
1081 			if (pack->map == NULL) {
1082 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1083 				    == -1) {
1084 					err = got_error_from_errno("lseek");
1085 					goto done;
1086 				}
1087 			}
1088 			if (base_file) {
1089 				if (pack->map) {
1090 					mapoff = (size_t)delta_data_offset;
1091 					err = got_inflate_to_file_mmap(
1092 					    &base_bufsz, pack->map, mapoff,
1093 					    pack->filesize - mapoff, base_file);
1094 				} else
1095 					err = got_inflate_to_file_fd(
1096 					    &base_bufsz, pack->fd, base_file);
1097 			} else {
1098 				if (pack->map) {
1099 					mapoff = (size_t)delta_data_offset;
1100 					err = got_inflate_to_mem_mmap(&base_buf,
1101 					    &base_bufsz, pack->map, mapoff,
1102 					    pack->filesize - mapoff);
1103 				} else
1104 					err = got_inflate_to_mem_fd(&base_buf,
1105 					    &base_bufsz, pack->fd);
1106 			}
1107 			if (err)
1108 				goto done;
1109 			n++;
1110 			if (base_file)
1111 				rewind(base_file);
1112 			continue;
1113 		}
1114 
1115 		got_delta_cache_get(&delta_buf, &delta_len,
1116 		    pack->delta_cache, delta->data_offset);
1117 		if (delta_buf == NULL) {
1118 			cached = 0;
1119 			err = read_delta_data(&delta_buf, &delta_len,
1120 			    delta->data_offset, pack);
1121 			if (err)
1122 				goto done;
1123 			err = got_delta_cache_add(pack->delta_cache,
1124 			    delta->data_offset, delta_buf, delta_len);
1125 			if (err == NULL)
1126 				cached = 1;
1127 			else if (err->code != GOT_ERR_NO_SPACE) {
1128 				free(delta_buf);
1129 				goto done;
1130 			}
1131 		}
1132 		if (base_buf) {
1133 			err = got_delta_apply_in_mem(base_buf, base_bufsz,
1134 			    delta_buf, delta_len, accum_buf,
1135 			    &accum_size, max_size);
1136 			n++;
1137 		} else {
1138 			err = got_delta_apply(base_file, delta_buf,
1139 			    delta_len,
1140 			    /* Final delta application writes to output file. */
1141 			    ++n < deltas->nentries ? accum_file : outfile,
1142 			    &accum_size);
1143 		}
1144 		if (!cached)
1145 			free(delta_buf);
1146 		if (err)
1147 			goto done;
1148 
1149 		if (n < deltas->nentries) {
1150 			/* Accumulated delta becomes the new base. */
1151 			if (base_buf) {
1152 				uint8_t *tmp = accum_buf;
1153 				/*
1154 				 * Base buffer switches roles with accumulation
1155 				 * buffer. Ensure it can hold the largest
1156 				 * result in the delta chain. The initial
1157 				 * allocation might have been smaller.
1158 				 */
1159 				if (base_bufsz < max_size) {
1160 					uint8_t *p;
1161 					p = reallocarray(base_buf, 1, max_size);
1162 					if (p == NULL) {
1163 						err = got_error_from_errno(
1164 						    "reallocarray");
1165 						goto done;
1166 					}
1167 					base_buf = p;
1168 					base_bufsz = max_size;
1169 				}
1170 				accum_buf = base_buf;
1171 				base_buf = tmp;
1172 			} else {
1173 				FILE *tmp = accum_file;
1174 				accum_file = base_file;
1175 				base_file = tmp;
1176 				rewind(base_file);
1177 				rewind(accum_file);
1178 			}
1179 		}
1180 	}
1181 
1182 done:
1183 	free(base_buf);
1184 	if (accum_buf) {
1185 		size_t len = fwrite(accum_buf, 1, accum_size, outfile);
1186 		free(accum_buf);
1187 		if (len != accum_size)
1188 			err = got_ferror(outfile, GOT_ERR_IO);
1189 	}
1190 	rewind(outfile);
1191 	if (err == NULL)
1192 		*result_size = accum_size;
1193 	return err;
1194 }
1195 
1196 static const struct got_error *
1197 dump_delta_chain_to_mem(uint8_t **outbuf, size_t *outlen,
1198     struct got_delta_chain *deltas, struct got_pack *pack)
1199 {
1200 	const struct got_error *err = NULL;
1201 	struct got_delta *delta;
1202 	uint8_t *base_buf = NULL, *accum_buf = NULL, *delta_buf;
1203 	size_t base_bufsz = 0, accum_size = 0, delta_len;
1204 	uint64_t max_size;
1205 	int n = 0;
1206 
1207 	*outbuf = NULL;
1208 	*outlen = 0;
1209 
1210 	if (SIMPLEQ_EMPTY(&deltas->entries))
1211 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1212 
1213 	err = get_delta_chain_max_size(&max_size, deltas, pack);
1214 	if (err)
1215 		return err;
1216 	accum_buf = malloc(max_size);
1217 	if (accum_buf == NULL)
1218 		return got_error_from_errno("malloc");
1219 
1220 	/* Deltas are ordered in ascending order. */
1221 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1222 		int cached = 1;
1223 		if (n == 0) {
1224 			size_t delta_data_offset;
1225 
1226 			/* Plain object types are the delta base. */
1227 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1228 			    delta->type != GOT_OBJ_TYPE_TREE &&
1229 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1230 			    delta->type != GOT_OBJ_TYPE_TAG) {
1231 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1232 				goto done;
1233 			}
1234 
1235 			delta_data_offset = delta->offset + delta->tslen;
1236 			if (delta_data_offset >= pack->filesize) {
1237 				err = got_error(GOT_ERR_PACK_OFFSET);
1238 				goto done;
1239 			}
1240 			if (pack->map) {
1241 				size_t mapoff = (size_t)delta_data_offset;
1242 				err = got_inflate_to_mem_mmap(&base_buf,
1243 				    &base_bufsz, pack->map, mapoff,
1244 				    pack->filesize - mapoff);
1245 			} else {
1246 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1247 				    == -1) {
1248 					err = got_error_from_errno("lseek");
1249 					goto done;
1250 				}
1251 				err = got_inflate_to_mem_fd(&base_buf,
1252 				    &base_bufsz, pack->fd);
1253 			}
1254 			if (err)
1255 				goto done;
1256 			n++;
1257 			continue;
1258 		}
1259 
1260 		got_delta_cache_get(&delta_buf, &delta_len,
1261 		    pack->delta_cache, delta->data_offset);
1262 		if (delta_buf == NULL) {
1263 			cached = 0;
1264 			err = read_delta_data(&delta_buf, &delta_len,
1265 			    delta->data_offset, pack);
1266 			if (err)
1267 				goto done;
1268 			err = got_delta_cache_add(pack->delta_cache,
1269 			    delta->data_offset, delta_buf, delta_len);
1270 			if (err == NULL)
1271 				cached = 1;
1272 			else if (err->code != GOT_ERR_NO_SPACE) {
1273 				free(delta_buf);
1274 				goto done;
1275 			}
1276 		}
1277 		err = got_delta_apply_in_mem(base_buf, base_bufsz,
1278 		    delta_buf, delta_len, accum_buf,
1279 		    &accum_size, max_size);
1280 		if (!cached)
1281 			free(delta_buf);
1282 		n++;
1283 		if (err)
1284 			goto done;
1285 
1286 		if (n < deltas->nentries) {
1287 			/* Accumulated delta becomes the new base. */
1288 			uint8_t *tmp = accum_buf;
1289 			/*
1290 			 * Base buffer switches roles with accumulation buffer.
1291 			 * Ensure it can hold the largest result in the delta
1292 			 * chain. Initial allocation might have been smaller.
1293 			 */
1294 			if (base_bufsz < max_size) {
1295 				uint8_t *p;
1296 				p = reallocarray(base_buf, 1, max_size);
1297 				if (p == NULL) {
1298 					err = got_error_from_errno(
1299 					    "reallocarray");
1300 					goto done;
1301 				}
1302 				base_buf = p;
1303 				base_bufsz = max_size;
1304 			}
1305 			accum_buf = base_buf;
1306 			base_buf = tmp;
1307 		}
1308 	}
1309 
1310 done:
1311 	free(base_buf);
1312 	if (err) {
1313 		free(accum_buf);
1314 		*outbuf = NULL;
1315 		*outlen = 0;
1316 	} else {
1317 		*outbuf = accum_buf;
1318 		*outlen = accum_size;
1319 	}
1320 	return err;
1321 }
1322 
1323 const struct got_error *
1324 got_packfile_extract_object(struct got_pack *pack, struct got_object *obj,
1325     FILE *outfile, FILE *base_file, FILE *accum_file)
1326 {
1327 	const struct got_error *err = NULL;
1328 
1329 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1330 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1331 
1332 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1333 		if (obj->pack_offset >= pack->filesize)
1334 			return got_error(GOT_ERR_PACK_OFFSET);
1335 
1336 		if (pack->map) {
1337 			size_t mapoff = (size_t)obj->pack_offset;
1338 			err = got_inflate_to_file_mmap(&obj->size, pack->map,
1339 			    mapoff, pack->filesize - mapoff, outfile);
1340 		} else {
1341 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1342 				return got_error_from_errno("lseek");
1343 			err = got_inflate_to_file_fd(&obj->size, pack->fd,
1344 			    outfile);
1345 		}
1346 	} else
1347 		err = dump_delta_chain_to_file(&obj->size, &obj->deltas, pack,
1348 		    outfile, base_file, accum_file);
1349 
1350 	return err;
1351 }
1352 
1353 const struct got_error *
1354 got_packfile_extract_object_to_mem(uint8_t **buf, size_t *len,
1355     struct got_object *obj, struct got_pack *pack)
1356 {
1357 	const struct got_error *err = NULL;
1358 
1359 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1360 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1361 
1362 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1363 		if (obj->pack_offset >= pack->filesize)
1364 			return got_error(GOT_ERR_PACK_OFFSET);
1365 		if (pack->map) {
1366 			size_t mapoff = (size_t)obj->pack_offset;
1367 			err = got_inflate_to_mem_mmap(buf, len, pack->map,
1368 			    mapoff, pack->filesize - mapoff);
1369 		} else {
1370 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1371 				return got_error_from_errno("lseek");
1372 			err = got_inflate_to_mem_fd(buf, len, pack->fd);
1373 		}
1374 	} else
1375 		err = dump_delta_chain_to_mem(buf, len, &obj->deltas, pack);
1376 
1377 	return err;
1378 }