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Date:: Wed Sep 9 21:41:22 2020 UTC
Message:: use the POSIX standard endian functions and explicitly include <endian.h> ok stsp
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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 <unistd.h>
33 #include <zlib.h>
34 #include <imsg.h>
35 
36 #include "got_error.h"
37 #include "got_object.h"
38 #include "got_opentemp.h"
39 #include "got_path.h"
40 
41 #include "got_lib_sha1.h"
42 #include "got_lib_delta.h"
43 #include "got_lib_delta_cache.h"
44 #include "got_lib_inflate.h"
45 #include "got_lib_object.h"
46 #include "got_lib_object_parse.h"
47 #include "got_lib_privsep.h"
48 #include "got_lib_pack.h"
49 
50 #ifndef nitems
51 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
52 #endif
53 
54 #ifndef MIN
55 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
56 #endif
57 
58 static const struct got_error *
59 verify_fanout_table(uint32_t *fanout_table)
60 {
61 	int i;
62 
63 	for (i = 0; i < 0xff - 1; i++) {
64 		if (be32toh(fanout_table[i]) > be32toh(fanout_table[i + 1]))
65 			return got_error(GOT_ERR_BAD_PACKIDX);
66 	}
67 
68 	return NULL;
69 }
70 
71 const struct got_error *
72 got_packidx_init_hdr(struct got_packidx *p, int verify)
73 {
74 	const struct got_error *err = NULL;
75 	struct got_packidx_v2_hdr *h;
76 	SHA1_CTX ctx;
77 	uint8_t sha1[SHA1_DIGEST_LENGTH];
78 	size_t nobj, len_fanout, len_ids, offset, remain;
79 	ssize_t n;
80 	int i;
81 
82 	SHA1Init(&ctx);
83 
84 	h = &p->hdr;
85 	offset = 0;
86 	remain = p->len;
87 
88 	if (remain < sizeof(*h->magic)) {
89 		err = got_error(GOT_ERR_BAD_PACKIDX);
90 		goto done;
91 	}
92 	if (p->map)
93 		h->magic = (uint32_t *)(p->map + offset);
94 	else {
95 		h->magic = malloc(sizeof(*h->magic));
96 		if (h->magic == NULL) {
97 			err = got_error_from_errno("malloc");
98 			goto done;
99 		}
100 		n = read(p->fd, h->magic, sizeof(*h->magic));
101 		if (n < 0) {
102 			err = got_error_from_errno("read");
103 			goto done;
104 		} else if (n != sizeof(*h->magic)) {
105 			err = got_error(GOT_ERR_BAD_PACKIDX);
106 			goto done;
107 		}
108 	}
109 	if (be32toh(*h->magic) != GOT_PACKIDX_V2_MAGIC) {
110 		err = got_error(GOT_ERR_BAD_PACKIDX);
111 		goto done;
112 	}
113 	offset += sizeof(*h->magic);
114 	remain -= sizeof(*h->magic);
115 
116 	if (verify)
117 		SHA1Update(&ctx, (uint8_t *)h->magic, sizeof(*h->magic));
118 
119 	if (remain < sizeof(*h->version)) {
120 		err = got_error(GOT_ERR_BAD_PACKIDX);
121 		goto done;
122 	}
123 	if (p->map)
124 		h->version = (uint32_t *)(p->map + offset);
125 	else {
126 		h->version = malloc(sizeof(*h->version));
127 		if (h->version == NULL) {
128 			err = got_error_from_errno("malloc");
129 			goto done;
130 		}
131 		n = read(p->fd, h->version, sizeof(*h->version));
132 		if (n < 0) {
133 			err = got_error_from_errno("read");
134 			goto done;
135 		} else if (n != sizeof(*h->version)) {
136 			err = got_error(GOT_ERR_BAD_PACKIDX);
137 			goto done;
138 		}
139 	}
140 	if (be32toh(*h->version) != GOT_PACKIDX_VERSION) {
141 		err = got_error(GOT_ERR_BAD_PACKIDX);
142 		goto done;
143 	}
144 	offset += sizeof(*h->version);
145 	remain -= sizeof(*h->version);
146 
147 	if (verify)
148 		SHA1Update(&ctx, (uint8_t *)h->version, sizeof(*h->version));
149 
150 	len_fanout =
151 	    sizeof(*h->fanout_table) * GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS;
152 	if (remain < len_fanout) {
153 		err = got_error(GOT_ERR_BAD_PACKIDX);
154 		goto done;
155 	}
156 	if (p->map)
157 		h->fanout_table = (uint32_t *)(p->map + offset);
158 	else {
159 		h->fanout_table = malloc(len_fanout);
160 		if (h->fanout_table == NULL) {
161 			err = got_error_from_errno("malloc");
162 			goto done;
163 		}
164 		n = read(p->fd, h->fanout_table, len_fanout);
165 		if (n < 0) {
166 			err = got_error_from_errno("read");
167 			goto done;
168 		} else if (n != len_fanout) {
169 			err = got_error(GOT_ERR_BAD_PACKIDX);
170 			goto done;
171 		}
172 	}
173 	err = verify_fanout_table(h->fanout_table);
174 	if (err)
175 		goto done;
176 	if (verify)
177 		SHA1Update(&ctx, (uint8_t *)h->fanout_table, len_fanout);
178 	offset += len_fanout;
179 	remain -= len_fanout;
180 
181 	nobj = be32toh(h->fanout_table[0xff]);
182 	len_ids = nobj * sizeof(*h->sorted_ids);
183 	if (len_ids <= nobj || len_ids > remain) {
184 		err = got_error(GOT_ERR_BAD_PACKIDX);
185 		goto done;
186 	}
187 	if (p->map)
188 		h->sorted_ids =
189 		    (struct got_packidx_object_id *)((uint8_t*)(p->map + offset));
190 	else {
191 		h->sorted_ids = malloc(len_ids);
192 		if (h->sorted_ids == NULL) {
193 			err = got_error(GOT_ERR_BAD_PACKIDX);
194 			goto done;
195 		}
196 		n = read(p->fd, h->sorted_ids, len_ids);
197 		if (n < 0)
198 			err = got_error_from_errno("read");
199 		else if (n != len_ids) {
200 			err = got_error(GOT_ERR_BAD_PACKIDX);
201 			goto done;
202 		}
203 	}
204 	if (verify)
205 		SHA1Update(&ctx, (uint8_t *)h->sorted_ids, len_ids);
206 	offset += len_ids;
207 	remain -= len_ids;
208 
209 	if (remain < nobj * sizeof(*h->crc32)) {
210 		err = got_error(GOT_ERR_BAD_PACKIDX);
211 		goto done;
212 	}
213 	if (p->map)
214 		h->crc32 = (uint32_t *)((uint8_t*)(p->map + offset));
215 	else {
216 		h->crc32 = malloc(nobj * sizeof(*h->crc32));
217 		if (h->crc32 == NULL) {
218 			err = got_error_from_errno("malloc");
219 			goto done;
220 		}
221 		n = read(p->fd, h->crc32, nobj * sizeof(*h->crc32));
222 		if (n < 0)
223 			err = got_error_from_errno("read");
224 		else if (n != nobj * sizeof(*h->crc32)) {
225 			err = got_error(GOT_ERR_BAD_PACKIDX);
226 			goto done;
227 		}
228 	}
229 	if (verify)
230 		SHA1Update(&ctx, (uint8_t *)h->crc32, nobj * sizeof(*h->crc32));
231 	remain -= nobj * sizeof(*h->crc32);
232 	offset += nobj * sizeof(*h->crc32);
233 
234 	if (remain < nobj * sizeof(*h->offsets)) {
235 		err = got_error(GOT_ERR_BAD_PACKIDX);
236 		goto done;
237 	}
238 	if (p->map)
239 		h->offsets = (uint32_t *)((uint8_t*)(p->map + offset));
240 	else {
241 		h->offsets = malloc(nobj * sizeof(*h->offsets));
242 		if (h->offsets == NULL) {
243 			err = got_error_from_errno("malloc");
244 			goto done;
245 		}
246 		n = read(p->fd, h->offsets, nobj * sizeof(*h->offsets));
247 		if (n < 0)
248 			err = got_error_from_errno("read");
249 		else if (n != nobj * sizeof(*h->offsets)) {
250 			err = got_error(GOT_ERR_BAD_PACKIDX);
251 			goto done;
252 		}
253 	}
254 	if (verify)
255 		SHA1Update(&ctx, (uint8_t *)h->offsets,
256 		    nobj * sizeof(*h->offsets));
257 	remain -= nobj * sizeof(*h->offsets);
258 	offset += nobj * sizeof(*h->offsets);
259 
260 	/* Large file offsets are contained only in files > 2GB. */
261 	for (i = 0; i < nobj; i++) {
262 		uint32_t o = be32toh(h->offsets[i]);
263 		if (o & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX)
264 			p->nlargeobj++;
265 	}
266 	if (p->nlargeobj == 0)
267 		goto checksum;
268 
269 	if (remain < p->nlargeobj * sizeof(*h->large_offsets)) {
270 		err = got_error(GOT_ERR_BAD_PACKIDX);
271 		goto done;
272 	}
273 	if (p->map)
274 		h->large_offsets = (uint64_t *)((uint8_t*)(p->map + offset));
275 	else {
276 		h->large_offsets = malloc(p->nlargeobj *
277 		    sizeof(*h->large_offsets));
278 		if (h->large_offsets == NULL) {
279 			err = got_error_from_errno("malloc");
280 			goto done;
281 		}
282 		n = read(p->fd, h->large_offsets,
283 		    p->nlargeobj * sizeof(*h->large_offsets));
284 		if (n < 0)
285 			err = got_error_from_errno("read");
286 		else if (n != p->nlargeobj * sizeof(*h->large_offsets)) {
287 			err = got_error(GOT_ERR_BAD_PACKIDX);
288 			goto done;
289 		}
290 	}
291 	if (verify)
292 		SHA1Update(&ctx, (uint8_t*)h->large_offsets,
293 		    p->nlargeobj * sizeof(*h->large_offsets));
294 	remain -= p->nlargeobj * sizeof(*h->large_offsets);
295 	offset += p->nlargeobj * sizeof(*h->large_offsets);
296 
297 checksum:
298 	if (remain < sizeof(*h->trailer)) {
299 		err = got_error(GOT_ERR_BAD_PACKIDX);
300 		goto done;
301 	}
302 	if (p->map)
303 		h->trailer =
304 		    (struct got_packidx_trailer *)((uint8_t*)(p->map + offset));
305 	else {
306 		h->trailer = malloc(sizeof(*h->trailer));
307 		if (h->trailer == NULL) {
308 			err = got_error_from_errno("malloc");
309 			goto done;
310 		}
311 		n = read(p->fd, h->trailer, sizeof(*h->trailer));
312 		if (n < 0)
313 			err = got_error_from_errno("read");
314 		else if (n != sizeof(*h->trailer)) {
315 			err = got_error(GOT_ERR_BAD_PACKIDX);
316 			goto done;
317 		}
318 	}
319 	if (verify) {
320 		SHA1Update(&ctx, h->trailer->packfile_sha1, SHA1_DIGEST_LENGTH);
321 		SHA1Final(sha1, &ctx);
322 		if (memcmp(h->trailer->packidx_sha1, sha1,
323 		    SHA1_DIGEST_LENGTH) != 0)
324 			err = got_error(GOT_ERR_PACKIDX_CSUM);
325 	}
326 done:
327 	return err;
328 }
329 
330 const struct got_error *
331 got_packidx_open(struct got_packidx **packidx, const char *path, int verify)
332 {
333 	const struct got_error *err = NULL;
334 	struct got_packidx *p;
335 	struct stat sb;
336 
337 	*packidx = NULL;
338 
339 	p = calloc(1, sizeof(*p));
340 	if (p == NULL)
341 		return got_error_from_errno("calloc");
342 
343 	p->fd = open(path, O_RDONLY | O_NOFOLLOW);
344 	if (p->fd == -1) {
345 		err = got_error_from_errno2("open", path);
346 		free(p);
347 		return err;
348 	}
349 
350 	if (fstat(p->fd, &sb) != 0) {
351 		err = got_error_from_errno2("fstat", path);
352 		close(p->fd);
353 		free(p);
354 		return err;
355 	}
356 	p->len = sb.st_size;
357 	if (p->len < sizeof(p->hdr)) {
358 		err = got_error(GOT_ERR_BAD_PACKIDX);
359 		close(p->fd);
360 		free(p);
361 		return err;
362 	}
363 
364 	p->path_packidx = strdup(path);
365 	if (p->path_packidx == NULL) {
366 		err = got_error_from_errno("strdup");
367 		goto done;
368 	}
369 
370 #ifndef GOT_PACK_NO_MMAP
371 	p->map = mmap(NULL, p->len, PROT_READ, MAP_PRIVATE, p->fd, 0);
372 	if (p->map == MAP_FAILED) {
373 		if (errno != ENOMEM) {
374 			err = got_error_from_errno("mmap");
375 			goto done;
376 		}
377 		p->map = NULL; /* fall back to read(2) */
378 	}
379 #endif
380 
381 	err = got_packidx_init_hdr(p, verify);
382 done:
383 	if (err)
384 		got_packidx_close(p);
385 	else
386 		*packidx = p;
387 
388 	return err;
389 }
390 
391 const struct got_error *
392 got_packidx_close(struct got_packidx *packidx)
393 {
394 	const struct got_error *err = NULL;
395 
396 	free(packidx->path_packidx);
397 	if (packidx->map) {
398 		if (munmap(packidx->map, packidx->len) == -1)
399 			err = got_error_from_errno("munmap");
400 	} else {
401 		free(packidx->hdr.magic);
402 		free(packidx->hdr.version);
403 		free(packidx->hdr.fanout_table);
404 		free(packidx->hdr.sorted_ids);
405 		free(packidx->hdr.crc32);
406 		free(packidx->hdr.offsets);
407 		free(packidx->hdr.large_offsets);
408 		free(packidx->hdr.trailer);
409 	}
410 	if (close(packidx->fd) != 0 && err == NULL)
411 		err = got_error_from_errno("close");
412 	free(packidx);
413 
414 	return err;
415 }
416 
417 static off_t
418 get_object_offset(struct got_packidx *packidx, int idx)
419 {
420 	uint32_t offset = be32toh(packidx->hdr.offsets[idx]);
421 	if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
422 		uint64_t loffset;
423 		idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
424 		if (idx < 0 || idx >= packidx->nlargeobj ||
425 		    packidx->hdr.large_offsets == NULL)
426 			return -1;
427 		loffset = be64toh(packidx->hdr.large_offsets[idx]);
428 		return (loffset > INT64_MAX ? -1 : (off_t)loffset);
429 	}
430 	return (off_t)(offset & GOT_PACKIDX_OFFSET_VAL_MASK);
431 }
432 
433 int
434 got_packidx_get_object_idx(struct got_packidx *packidx, struct got_object_id *id)
435 {
436 	u_int8_t id0 = id->sha1[0];
437 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
438 	int left = 0, right = totobj - 1;
439 
440 	if (id0 > 0)
441 		left = be32toh(packidx->hdr.fanout_table[id0 - 1]);
442 
443 	while (left <= right) {
444 		struct got_packidx_object_id *oid;
445 		int i, cmp;
446 
447 		i = ((left + right) / 2);
448 		oid = &packidx->hdr.sorted_ids[i];
449 		cmp = memcmp(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
450 		if (cmp == 0)
451 			return i;
452 		else if (cmp > 0)
453 			left = i + 1;
454 		else if (cmp < 0)
455 			right = i - 1;
456 	}
457 
458 	return -1;
459 }
460 
461 const struct got_error *
462 got_packidx_match_id_str_prefix(struct got_object_id_queue *matched_ids,
463     struct got_packidx *packidx, const char *id_str_prefix)
464 {
465 	const struct got_error *err = NULL;
466 	u_int8_t id0;
467 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
468 	char hex[3];
469 	size_t prefix_len = strlen(id_str_prefix);
470 	struct got_packidx_object_id *oid;
471 	int i;
472 
473 	SIMPLEQ_INIT(matched_ids);
474 
475 	if (prefix_len < 2)
476 		return got_error_path(id_str_prefix, GOT_ERR_BAD_OBJ_ID_STR);
477 
478 	hex[0] = id_str_prefix[0];
479 	hex[1] = id_str_prefix[1];
480 	hex[2] = '\0';
481 	if (!got_parse_xdigit(&id0, hex))
482 		return got_error_path(id_str_prefix, GOT_ERR_BAD_OBJ_ID_STR);
483 
484 	i = be32toh(packidx->hdr.fanout_table[id0 - 1]);
485 	if (i == 0)
486 		return NULL;
487 
488 	oid = &packidx->hdr.sorted_ids[i];
489 	while (i < totobj && oid->sha1[0] == id0) {
490 		char id_str[SHA1_DIGEST_STRING_LENGTH];
491 		struct got_object_qid *qid;
492 		int cmp;
493 
494 		if (!got_sha1_digest_to_str(oid->sha1, id_str, sizeof(id_str)))
495 		        return got_error(GOT_ERR_NO_SPACE);
496 
497 		cmp = strncmp(id_str, id_str_prefix, prefix_len);
498 		if (cmp < 0) {
499 			oid = &packidx->hdr.sorted_ids[++i];
500 			continue;
501 		} else if (cmp > 0)
502 			break;
503 
504 		err = got_object_qid_alloc_partial(&qid);
505 		if (err)
506 			break;
507 		memcpy(qid->id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
508 		SIMPLEQ_INSERT_TAIL(matched_ids, qid, entry);
509 
510 		oid = &packidx->hdr.sorted_ids[++i];
511 	}
512 
513 	if (err)
514 		got_object_id_queue_free(matched_ids);
515 	return err;
516 }
517 
518 const struct got_error *
519 got_pack_stop_privsep_child(struct got_pack *pack)
520 {
521 	const struct got_error *err = NULL;
522 
523 	if (pack->privsep_child == NULL)
524 		return NULL;
525 
526 	err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
527 	if (err)
528 		return err;
529 	err = got_privsep_wait_for_child(pack->privsep_child->pid);
530 	if (close(pack->privsep_child->imsg_fd) != 0 && err == NULL)
531 		err = got_error_from_errno("close");
532 	free(pack->privsep_child);
533 	pack->privsep_child = NULL;
534 	return err;
535 }
536 
537 const struct got_error *
538 got_pack_close(struct got_pack *pack)
539 {
540 	const struct got_error *err = NULL;
541 
542 	err = got_pack_stop_privsep_child(pack);
543 	if (pack->map && munmap(pack->map, pack->filesize) == -1 && !err)
544 		err = got_error_from_errno("munmap");
545 	if (pack->fd != -1 && close(pack->fd) != 0 && err == NULL)
546 		err = got_error_from_errno("close");
547 	pack->fd = -1;
548 	free(pack->path_packfile);
549 	pack->path_packfile = NULL;
550 	pack->filesize = 0;
551 	if (pack->delta_cache) {
552 		got_delta_cache_free(pack->delta_cache);
553 		pack->delta_cache = NULL;
554 	}
555 
556 	return err;
557 }
558 
559 const struct got_error *
560 got_pack_parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len,
561     struct got_pack *pack, off_t offset)
562 {
563 	uint8_t t = 0;
564 	uint64_t s = 0;
565 	uint8_t sizeN;
566 	size_t mapoff = 0;
567 	int i = 0;
568 
569 	*len = 0;
570 
571 	if (offset >= pack->filesize)
572 		return got_error(GOT_ERR_PACK_OFFSET);
573 
574 	if (pack->map) {
575 		mapoff = (size_t)offset;
576 	} else {
577 		if (lseek(pack->fd, offset, SEEK_SET) == -1)
578 			return got_error_from_errno("lseek");
579 	}
580 
581 	do {
582 		/* We do not support size values which don't fit in 64 bit. */
583 		if (i > 9)
584 			return got_error(GOT_ERR_NO_SPACE);
585 
586 		if (pack->map) {
587 			sizeN = *(pack->map + mapoff);
588 			mapoff += sizeof(sizeN);
589 		} else {
590 			ssize_t n = read(pack->fd, &sizeN, sizeof(sizeN));
591 			if (n < 0)
592 				return got_error_from_errno("read");
593 			if (n != sizeof(sizeN))
594 				return got_error(GOT_ERR_BAD_PACKFILE);
595 		}
596 		*len += sizeof(sizeN);
597 
598 		if (i == 0) {
599 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
600 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
601 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
602 		} else {
603 			size_t shift = 4 + 7 * (i - 1);
604 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
605 		}
606 		i++;
607 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
608 
609 	*type = t;
610 	*size = s;
611 	return NULL;
612 }
613 
614 static const struct got_error *
615 open_plain_object(struct got_object **obj, struct got_object_id *id,
616     uint8_t type, off_t offset, size_t size, int idx)
617 {
618 	*obj = calloc(1, sizeof(**obj));
619 	if (*obj == NULL)
620 		return got_error_from_errno("calloc");
621 
622 	(*obj)->type = type;
623 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
624 	(*obj)->pack_idx = idx;
625 	(*obj)->hdrlen = 0;
626 	(*obj)->size = size;
627 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
628 	(*obj)->pack_offset = offset;
629 
630 	return NULL;
631 }
632 
633 static const struct got_error *
634 parse_negative_offset(int64_t *offset, size_t *len, struct got_pack *pack,
635     off_t delta_offset)
636 {
637 	int64_t o = 0;
638 	uint8_t offN;
639 	int i = 0;
640 
641 	*offset = 0;
642 	*len = 0;
643 
644 	do {
645 		/* We do not support offset values which don't fit in 64 bit. */
646 		if (i > 8)
647 			return got_error(GOT_ERR_NO_SPACE);
648 
649 		if (pack->map) {
650 			size_t mapoff;
651 			if (delta_offset >= pack->filesize)
652 				return got_error(GOT_ERR_PACK_OFFSET);
653 			mapoff = (size_t)delta_offset + *len;
654 			offN = *(pack->map + mapoff);
655 		} else {
656 			ssize_t n;
657 			n = read(pack->fd, &offN, sizeof(offN));
658 			if (n < 0)
659 				return got_error_from_errno("read");
660 			if (n != sizeof(offN))
661 				return got_error(GOT_ERR_BAD_PACKFILE);
662 		}
663 		*len += sizeof(offN);
664 
665 		if (i == 0)
666 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
667 		else {
668 			o++;
669 			o <<= 7;
670 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
671 		}
672 		i++;
673 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
674 
675 	*offset = o;
676 	return NULL;
677 }
678 
679 const struct got_error *
680 got_pack_parse_offset_delta(off_t *base_offset, size_t *len, struct got_pack *pack,
681     off_t offset, int tslen)
682 {
683 	const struct got_error *err;
684 	int64_t negoffset;
685 	size_t negofflen;
686 
687 	*len = 0;
688 
689 	err = parse_negative_offset(&negoffset, &negofflen, pack,
690 	    offset + tslen);
691 	if (err)
692 		return err;
693 
694 	/* Compute the base object's offset (must be in the same pack file). */
695 	*base_offset = (offset - negoffset);
696 	if (*base_offset <= 0)
697 		return got_error(GOT_ERR_BAD_PACKFILE);
698 
699 	*len = negofflen;
700 	return NULL;
701 }
702 
703 static const struct got_error *
704 read_delta_data(uint8_t **delta_buf, size_t *delta_len,
705     size_t delta_data_offset, struct got_pack *pack)
706 {
707 	const struct got_error *err = NULL;
708 
709 	if (pack->map) {
710 		if (delta_data_offset >= pack->filesize)
711 			return got_error(GOT_ERR_PACK_OFFSET);
712 		err = got_inflate_to_mem_mmap(delta_buf, delta_len,
713 		    NULL, NULL, pack->map, delta_data_offset,
714 		    pack->filesize - delta_data_offset);
715 	} else {
716 		if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1)
717 			return got_error_from_errno("lseek");
718 		err = got_inflate_to_mem_fd(delta_buf, delta_len, NULL,
719 		    NULL, 0, pack->fd);
720 	}
721 	return err;
722 }
723 
724 static const struct got_error *
725 add_delta(struct got_delta_chain *deltas, off_t delta_offset, size_t tslen,
726     int delta_type, size_t delta_size, size_t delta_data_offset)
727 {
728 	struct got_delta *delta;
729 
730 	delta = got_delta_open(delta_offset, tslen, delta_type, delta_size,
731 	    delta_data_offset);
732 	if (delta == NULL)
733 		return got_error_from_errno("got_delta_open");
734 	/* delta is freed in got_object_close() */
735 	deltas->nentries++;
736 	SIMPLEQ_INSERT_HEAD(&deltas->entries, delta, entry);
737 	return NULL;
738 }
739 
740 static const struct got_error *
741 resolve_offset_delta(struct got_delta_chain *deltas,
742     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
743     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
744 
745 {
746 	const struct got_error *err;
747 	off_t base_offset;
748 	uint8_t base_type;
749 	uint64_t base_size;
750 	size_t base_tslen;
751 	off_t delta_data_offset;
752 	size_t consumed;
753 
754 	err = got_pack_parse_offset_delta(&base_offset, &consumed, pack,
755 	    delta_offset, tslen);
756 	if (err)
757 		return err;
758 
759 	delta_data_offset = delta_offset + tslen + consumed;
760 	if (delta_data_offset >= pack->filesize)
761 		return got_error(GOT_ERR_PACK_OFFSET);
762 
763 	if (pack->map == NULL) {
764 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
765 		if (delta_data_offset == -1)
766 			return got_error_from_errno("lseek");
767 	}
768 
769 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
770 	    delta_data_offset);
771 	if (err)
772 		return err;
773 
774 	/* An offset delta must be in the same packfile. */
775 	if (base_offset >= pack->filesize)
776 		return got_error(GOT_ERR_PACK_OFFSET);
777 
778 	err = got_pack_parse_object_type_and_size(&base_type, &base_size,
779 	    &base_tslen, pack, base_offset);
780 	if (err)
781 		return err;
782 
783 	return got_pack_resolve_delta_chain(deltas, packidx, pack, base_offset,
784 	    base_tslen, base_type, base_size, recursion - 1);
785 }
786 
787 static const struct got_error *
788 resolve_ref_delta(struct got_delta_chain *deltas, struct got_packidx *packidx,
789     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
790     size_t delta_size, unsigned int recursion)
791 {
792 	const struct got_error *err;
793 	struct got_object_id id;
794 	int idx;
795 	off_t base_offset;
796 	uint8_t base_type;
797 	uint64_t base_size;
798 	size_t base_tslen;
799 	off_t delta_data_offset;
800 
801 	if (delta_offset + tslen >= pack->filesize)
802 		return got_error(GOT_ERR_PACK_OFFSET);
803 
804 	if (pack->map) {
805 		size_t mapoff = delta_offset + tslen;
806 		memcpy(&id, pack->map + mapoff, sizeof(id));
807 		mapoff += sizeof(id);
808 		delta_data_offset = (off_t)mapoff;
809 	} else {
810 		ssize_t n;
811 		n = read(pack->fd, &id, sizeof(id));
812 		if (n < 0)
813 			return got_error_from_errno("read");
814 		if (n != sizeof(id))
815 			return got_error(GOT_ERR_BAD_PACKFILE);
816 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
817 		if (delta_data_offset == -1)
818 			return got_error_from_errno("lseek");
819 	}
820 
821 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
822 	    delta_data_offset);
823 	if (err)
824 		return err;
825 
826 	/* Delta base must be in the same pack file. */
827 	idx = got_packidx_get_object_idx(packidx, &id);
828 	if (idx == -1)
829 		return got_error(GOT_ERR_NO_OBJ);
830 
831 	base_offset = get_object_offset(packidx, idx);
832 	if (base_offset == (uint64_t)-1)
833 		return got_error(GOT_ERR_BAD_PACKIDX);
834 
835 	if (base_offset >= pack->filesize)
836 		return got_error(GOT_ERR_PACK_OFFSET);
837 
838 	err = got_pack_parse_object_type_and_size(&base_type, &base_size,
839 	    &base_tslen, pack, base_offset);
840 	if (err)
841 		return err;
842 
843 	return got_pack_resolve_delta_chain(deltas, packidx, pack, base_offset,
844 	    base_tslen, base_type, base_size, recursion - 1);
845 }
846 
847 const struct got_error *
848 got_pack_resolve_delta_chain(struct got_delta_chain *deltas,
849     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
850     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
851 {
852 	const struct got_error *err = NULL;
853 
854 	if (--recursion == 0)
855 		return got_error(GOT_ERR_RECURSION);
856 
857 	switch (delta_type) {
858 	case GOT_OBJ_TYPE_COMMIT:
859 	case GOT_OBJ_TYPE_TREE:
860 	case GOT_OBJ_TYPE_BLOB:
861 	case GOT_OBJ_TYPE_TAG:
862 		/* Plain types are the final delta base. Recursion ends. */
863 		err = add_delta(deltas, delta_offset, tslen, delta_type,
864 		    delta_size, 0);
865 		break;
866 	case GOT_OBJ_TYPE_OFFSET_DELTA:
867 		err = resolve_offset_delta(deltas, packidx, pack,
868 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
869 		break;
870 	case GOT_OBJ_TYPE_REF_DELTA:
871 		err = resolve_ref_delta(deltas, packidx, pack,
872 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
873 		break;
874 	default:
875 		return got_error(GOT_ERR_OBJ_TYPE);
876 	}
877 
878 	return err;
879 }
880 
881 static const struct got_error *
882 open_delta_object(struct got_object **obj, struct got_packidx *packidx,
883     struct got_pack *pack, struct got_object_id *id, off_t offset,
884     size_t tslen, int delta_type, size_t delta_size, int idx)
885 {
886 	const struct got_error *err = NULL;
887 	int resolved_type;
888 
889 	*obj = calloc(1, sizeof(**obj));
890 	if (*obj == NULL)
891 		return got_error_from_errno("calloc");
892 
893 	(*obj)->flags = 0;
894 	(*obj)->hdrlen = 0;
895 	(*obj)->size = 0; /* Not known because deltas aren't applied yet. */
896 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
897 	(*obj)->pack_offset = offset + tslen;
898 
899 	SIMPLEQ_INIT(&(*obj)->deltas.entries);
900 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
901 	(*obj)->flags |= GOT_OBJ_FLAG_PACKED;
902 	(*obj)->pack_idx = idx;
903 
904 	err = got_pack_resolve_delta_chain(&(*obj)->deltas, packidx, pack,
905 	    offset, tslen, delta_type, delta_size,
906 	    GOT_DELTA_CHAIN_RECURSION_MAX);
907 	if (err)
908 		goto done;
909 
910 	err = got_delta_chain_get_base_type(&resolved_type, &(*obj)->deltas);
911 	if (err)
912 		goto done;
913 	(*obj)->type = resolved_type;
914 done:
915 	if (err) {
916 		got_object_close(*obj);
917 		*obj = NULL;
918 	}
919 	return err;
920 }
921 
922 const struct got_error *
923 got_packfile_open_object(struct got_object **obj, struct got_pack *pack,
924     struct got_packidx *packidx, int idx, struct got_object_id *id)
925 {
926 	const struct got_error *err = NULL;
927 	off_t offset;
928 	uint8_t type;
929 	uint64_t size;
930 	size_t tslen;
931 
932 	*obj = NULL;
933 
934 	offset = get_object_offset(packidx, idx);
935 	if (offset == (uint64_t)-1)
936 		return got_error(GOT_ERR_BAD_PACKIDX);
937 
938 	err = got_pack_parse_object_type_and_size(&type, &size, &tslen,
939 	    pack, offset);
940 	if (err)
941 		return err;
942 
943 	switch (type) {
944 	case GOT_OBJ_TYPE_COMMIT:
945 	case GOT_OBJ_TYPE_TREE:
946 	case GOT_OBJ_TYPE_BLOB:
947 	case GOT_OBJ_TYPE_TAG:
948 		err = open_plain_object(obj, id, type, offset + tslen,
949 		    size, idx);
950 		break;
951 	case GOT_OBJ_TYPE_OFFSET_DELTA:
952 	case GOT_OBJ_TYPE_REF_DELTA:
953 		err = open_delta_object(obj, packidx, pack, id, offset,
954 		    tslen, type, size, idx);
955 		break;
956 	default:
957 		err = got_error(GOT_ERR_OBJ_TYPE);
958 		break;
959 	}
960 
961 	return err;
962 }
963 
964 const struct got_error *
965 got_pack_get_delta_chain_max_size(uint64_t *max_size, struct got_delta_chain *deltas,
966     struct got_pack *pack)
967 {
968 	struct got_delta *delta;
969 	uint64_t base_size = 0, result_size = 0;
970 
971 	*max_size = 0;
972 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
973 		/* Plain object types are the delta base. */
974 		if (delta->type != GOT_OBJ_TYPE_COMMIT &&
975 		    delta->type != GOT_OBJ_TYPE_TREE &&
976 		    delta->type != GOT_OBJ_TYPE_BLOB &&
977 		    delta->type != GOT_OBJ_TYPE_TAG) {
978 			const struct got_error *err;
979 			uint8_t *delta_buf;
980 			size_t delta_len;
981 			int cached = 1;
982 
983 			got_delta_cache_get(&delta_buf, &delta_len,
984 			    pack->delta_cache, delta->data_offset);
985 			if (delta_buf == NULL) {
986 				cached = 0;
987 				err = read_delta_data(&delta_buf, &delta_len,
988 				    delta->data_offset, pack);
989 				if (err)
990 					return err;
991 				err = got_delta_cache_add(pack->delta_cache,
992 				    delta->data_offset, delta_buf, delta_len);
993 				if (err == NULL)
994 					cached = 1;
995 				else if (err->code != GOT_ERR_NO_SPACE) {
996 					free(delta_buf);
997 					return err;
998 				}
999 			}
1000 			err = got_delta_get_sizes(&base_size, &result_size,
1001 			    delta_buf, delta_len);
1002 			if (!cached)
1003 				free(delta_buf);
1004 			if (err)
1005 				return err;
1006 		} else
1007 			base_size = delta->size;
1008 		if (base_size > *max_size)
1009 			*max_size = base_size;
1010 		if (result_size > *max_size)
1011 			*max_size = result_size;
1012 	}
1013 
1014 	return NULL;
1015 }
1016 
1017 const struct got_error *
1018 got_pack_get_max_delta_object_size(uint64_t *size, struct got_object *obj,
1019     struct got_pack *pack)
1020 {
1021 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0)
1022 		return got_error(GOT_ERR_OBJ_TYPE);
1023 
1024 	return got_pack_get_delta_chain_max_size(size, &obj->deltas, pack);
1025 }
1026 
1027 const struct got_error *
1028 got_pack_dump_delta_chain_to_file(size_t *result_size,
1029     struct got_delta_chain *deltas, struct got_pack *pack, FILE *outfile,
1030     FILE *base_file, FILE *accum_file)
1031 {
1032 	const struct got_error *err = NULL;
1033 	struct got_delta *delta;
1034 	uint8_t *base_buf = NULL, *accum_buf = NULL, *delta_buf;
1035 	size_t base_bufsz = 0, accum_size = 0, delta_len;
1036 	uint64_t max_size;
1037 	int n = 0;
1038 
1039 	*result_size = 0;
1040 
1041 	if (SIMPLEQ_EMPTY(&deltas->entries))
1042 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1043 
1044 	/* We process small enough files entirely in memory for speed. */
1045 	err = got_pack_get_delta_chain_max_size(&max_size, deltas, pack);
1046 	if (err)
1047 		return err;
1048 	if (max_size < GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
1049 		accum_buf = malloc(max_size);
1050 		if (accum_buf == NULL)
1051 			return got_error_from_errno("malloc");
1052 		base_file = NULL;
1053 		accum_file = NULL;
1054 	}
1055 
1056 	/* Deltas are ordered in ascending order. */
1057 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1058 		int cached = 1;
1059 		if (n == 0) {
1060 			size_t mapoff;
1061 			off_t delta_data_offset;
1062 
1063 			/* Plain object types are the delta base. */
1064 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1065 			    delta->type != GOT_OBJ_TYPE_TREE &&
1066 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1067 			    delta->type != GOT_OBJ_TYPE_TAG) {
1068 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1069 				goto done;
1070 			}
1071 
1072 			delta_data_offset = delta->offset + delta->tslen;
1073 			if (delta_data_offset >= pack->filesize) {
1074 				err = got_error(GOT_ERR_PACK_OFFSET);
1075 				goto done;
1076 			}
1077 			if (pack->map == NULL) {
1078 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1079 				    == -1) {
1080 					err = got_error_from_errno("lseek");
1081 					goto done;
1082 				}
1083 			}
1084 			if (base_file) {
1085 				if (pack->map) {
1086 					mapoff = (size_t)delta_data_offset;
1087 					err = got_inflate_to_file_mmap(
1088 					    &base_bufsz, NULL, NULL, pack->map,
1089 					    mapoff, pack->filesize - mapoff,
1090 					    base_file);
1091 				} else
1092 					err = got_inflate_to_file_fd(
1093 					    &base_bufsz, NULL, NULL, pack->fd,
1094 					    base_file);
1095 			} else {
1096 				if (pack->map) {
1097 					mapoff = (size_t)delta_data_offset;
1098 					err = got_inflate_to_mem_mmap(&base_buf,
1099 					    &base_bufsz, NULL, NULL,
1100 					    pack->map, mapoff,
1101 					    pack->filesize - mapoff);
1102 				} else
1103 					err = got_inflate_to_mem_fd(&base_buf,
1104 					    &base_bufsz, NULL, NULL, max_size,
1105 					    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 const struct got_error *
1197 got_pack_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 = got_pack_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, NULL, NULL, pack->map,
1244 				    mapoff, 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, NULL, NULL, max_size,
1253 				    pack->fd);
1254 			}
1255 			if (err)
1256 				goto done;
1257 			n++;
1258 			continue;
1259 		}
1260 
1261 		got_delta_cache_get(&delta_buf, &delta_len,
1262 		    pack->delta_cache, delta->data_offset);
1263 		if (delta_buf == NULL) {
1264 			cached = 0;
1265 			err = read_delta_data(&delta_buf, &delta_len,
1266 			    delta->data_offset, pack);
1267 			if (err)
1268 				goto done;
1269 			err = got_delta_cache_add(pack->delta_cache,
1270 			    delta->data_offset, delta_buf, delta_len);
1271 			if (err == NULL)
1272 				cached = 1;
1273 			else if (err->code != GOT_ERR_NO_SPACE) {
1274 				free(delta_buf);
1275 				goto done;
1276 			}
1277 		}
1278 		err = got_delta_apply_in_mem(base_buf, base_bufsz,
1279 		    delta_buf, delta_len, accum_buf,
1280 		    &accum_size, max_size);
1281 		if (!cached)
1282 			free(delta_buf);
1283 		n++;
1284 		if (err)
1285 			goto done;
1286 
1287 		if (n < deltas->nentries) {
1288 			/* Accumulated delta becomes the new base. */
1289 			uint8_t *tmp = accum_buf;
1290 			/*
1291 			 * Base buffer switches roles with accumulation buffer.
1292 			 * Ensure it can hold the largest result in the delta
1293 			 * chain. Initial allocation might have been smaller.
1294 			 */
1295 			if (base_bufsz < max_size) {
1296 				uint8_t *p;
1297 				p = reallocarray(base_buf, 1, max_size);
1298 				if (p == NULL) {
1299 					err = got_error_from_errno(
1300 					    "reallocarray");
1301 					goto done;
1302 				}
1303 				base_buf = p;
1304 				base_bufsz = max_size;
1305 			}
1306 			accum_buf = base_buf;
1307 			base_buf = tmp;
1308 		}
1309 	}
1310 
1311 done:
1312 	free(base_buf);
1313 	if (err) {
1314 		free(accum_buf);
1315 		*outbuf = NULL;
1316 		*outlen = 0;
1317 	} else {
1318 		*outbuf = accum_buf;
1319 		*outlen = accum_size;
1320 	}
1321 	return err;
1322 }
1323 
1324 const struct got_error *
1325 got_packfile_extract_object(struct got_pack *pack, struct got_object *obj,
1326     FILE *outfile, FILE *base_file, FILE *accum_file)
1327 {
1328 	const struct got_error *err = NULL;
1329 
1330 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1331 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1332 
1333 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1334 		if (obj->pack_offset >= pack->filesize)
1335 			return got_error(GOT_ERR_PACK_OFFSET);
1336 
1337 		if (pack->map) {
1338 			size_t mapoff = (size_t)obj->pack_offset;
1339 			err = got_inflate_to_file_mmap(&obj->size, NULL, NULL,
1340 			    pack->map, mapoff, pack->filesize - mapoff,
1341 			    outfile);
1342 		} else {
1343 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1344 				return got_error_from_errno("lseek");
1345 			err = got_inflate_to_file_fd(&obj->size, NULL, NULL,
1346 			    pack->fd, outfile);
1347 		}
1348 	} else
1349 		err = got_pack_dump_delta_chain_to_file(&obj->size,
1350 		    &obj->deltas, pack, outfile, base_file, accum_file);
1351 
1352 	return err;
1353 }
1354 
1355 const struct got_error *
1356 got_packfile_extract_object_to_mem(uint8_t **buf, size_t *len,
1357     struct got_object *obj, struct got_pack *pack)
1358 {
1359 	const struct got_error *err = NULL;
1360 
1361 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1362 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1363 
1364 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1365 		if (obj->pack_offset >= pack->filesize)
1366 			return got_error(GOT_ERR_PACK_OFFSET);
1367 		if (pack->map) {
1368 			size_t mapoff = (size_t)obj->pack_offset;
1369 			err = got_inflate_to_mem_mmap(buf, len, NULL, NULL,
1370 			    pack->map, mapoff, pack->filesize - mapoff);
1371 		} else {
1372 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1373 				return got_error_from_errno("lseek");
1374 			err = got_inflate_to_mem_fd(buf, len, NULL, NULL,
1375 			    obj->size, pack->fd);
1376 		}
1377 	} else
1378 		err = got_pack_dump_delta_chain_to_mem(buf, len, &obj->deltas,
1379 		    pack);
1380 
1381 	return err;
1382 }