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 #include <sys/resource.h>
23 #include <sys/socket.h>
24 
25 #include <fcntl.h>
26 #include <errno.h>
27 #include <stdio.h>
28 #include <stdint.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <limits.h>
32 #include <sha1.h>
33 #include <endian.h>
34 #include <unistd.h>
35 #include <zlib.h>
36 #include <imsg.h>
37 
38 #include "got_error.h"
39 #include "got_object.h"
40 #include "got_path.h"
41 
42 #include "got_lib_sha1.h"
43 #include "got_lib_delta.h"
44 #include "got_lib_delta_cache.h"
45 #include "got_lib_inflate.h"
46 #include "got_lib_object.h"
47 #include "got_lib_object_parse.h"
48 #include "got_lib_privsep.h"
49 #include "got_lib_pack.h"
50 
51 #ifndef nitems
52 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
53 #endif
54 
55 #ifndef MIN
56 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
57 #endif
58 
59 static const struct got_error *
60 verify_fanout_table(uint32_t *fanout_table)
61 {
62 	int i;
63 
64 	for (i = 0; i < 0xff - 1; i++) {
65 		if (be32toh(fanout_table[i]) > be32toh(fanout_table[i + 1]))
66 			return got_error(GOT_ERR_BAD_PACKIDX);
67 	}
68 
69 	return NULL;
70 }
71 
72 const struct got_error *
73 got_packidx_init_hdr(struct got_packidx *p, int verify, off_t packfile_size)
74 {
75 	const struct got_error *err = NULL;
76 	struct got_packidx_v2_hdr *h;
77 	SHA1_CTX ctx;
78 	uint8_t sha1[SHA1_DIGEST_LENGTH];
79 	size_t nobj, len_fanout, len_ids, offset, remain;
80 	ssize_t n;
81 	int i;
82 
83 	SHA1Init(&ctx);
84 
85 	h = &p->hdr;
86 	offset = 0;
87 	remain = p->len;
88 
89 	if (remain < sizeof(*h->magic)) {
90 		err = got_error(GOT_ERR_BAD_PACKIDX);
91 		goto done;
92 	}
93 	if (p->map)
94 		h->magic = (uint32_t *)(p->map + offset);
95 	else {
96 		h->magic = malloc(sizeof(*h->magic));
97 		if (h->magic == NULL) {
98 			err = got_error_from_errno("malloc");
99 			goto done;
100 		}
101 		n = read(p->fd, h->magic, sizeof(*h->magic));
102 		if (n < 0) {
103 			err = got_error_from_errno("read");
104 			goto done;
105 		} else if (n != sizeof(*h->magic)) {
106 			err = got_error(GOT_ERR_BAD_PACKIDX);
107 			goto done;
108 		}
109 	}
110 	if (*h->magic != htobe32(GOT_PACKIDX_V2_MAGIC)) {
111 		err = got_error(GOT_ERR_BAD_PACKIDX);
112 		goto done;
113 	}
114 	offset += sizeof(*h->magic);
115 	remain -= sizeof(*h->magic);
116 
117 	if (verify)
118 		SHA1Update(&ctx, (uint8_t *)h->magic, sizeof(*h->magic));
119 
120 	if (remain < sizeof(*h->version)) {
121 		err = got_error(GOT_ERR_BAD_PACKIDX);
122 		goto done;
123 	}
124 	if (p->map)
125 		h->version = (uint32_t *)(p->map + offset);
126 	else {
127 		h->version = malloc(sizeof(*h->version));
128 		if (h->version == NULL) {
129 			err = got_error_from_errno("malloc");
130 			goto done;
131 		}
132 		n = read(p->fd, h->version, sizeof(*h->version));
133 		if (n < 0) {
134 			err = got_error_from_errno("read");
135 			goto done;
136 		} else if (n != sizeof(*h->version)) {
137 			err = got_error(GOT_ERR_BAD_PACKIDX);
138 			goto done;
139 		}
140 	}
141 	if (*h->version != htobe32(GOT_PACKIDX_VERSION)) {
142 		err = got_error(GOT_ERR_BAD_PACKIDX);
143 		goto done;
144 	}
145 	offset += sizeof(*h->version);
146 	remain -= sizeof(*h->version);
147 
148 	if (verify)
149 		SHA1Update(&ctx, (uint8_t *)h->version, sizeof(*h->version));
150 
151 	len_fanout =
152 	    sizeof(*h->fanout_table) * GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS;
153 	if (remain < len_fanout) {
154 		err = got_error(GOT_ERR_BAD_PACKIDX);
155 		goto done;
156 	}
157 	if (p->map)
158 		h->fanout_table = (uint32_t *)(p->map + offset);
159 	else {
160 		h->fanout_table = malloc(len_fanout);
161 		if (h->fanout_table == NULL) {
162 			err = got_error_from_errno("malloc");
163 			goto done;
164 		}
165 		n = read(p->fd, h->fanout_table, len_fanout);
166 		if (n < 0) {
167 			err = got_error_from_errno("read");
168 			goto done;
169 		} else if (n != len_fanout) {
170 			err = got_error(GOT_ERR_BAD_PACKIDX);
171 			goto done;
172 		}
173 	}
174 	err = verify_fanout_table(h->fanout_table);
175 	if (err)
176 		goto done;
177 	if (verify)
178 		SHA1Update(&ctx, (uint8_t *)h->fanout_table, len_fanout);
179 	offset += len_fanout;
180 	remain -= len_fanout;
181 
182 	nobj = be32toh(h->fanout_table[0xff]);
183 	len_ids = nobj * sizeof(*h->sorted_ids);
184 	if (len_ids <= nobj || len_ids > remain) {
185 		err = got_error(GOT_ERR_BAD_PACKIDX);
186 		goto done;
187 	}
188 	if (p->map)
189 		h->sorted_ids =
190 		    (struct got_packidx_object_id *)((uint8_t*)(p->map + offset));
191 	else {
192 		h->sorted_ids = malloc(len_ids);
193 		if (h->sorted_ids == NULL) {
194 			err = got_error(GOT_ERR_BAD_PACKIDX);
195 			goto done;
196 		}
197 		n = read(p->fd, h->sorted_ids, len_ids);
198 		if (n < 0)
199 			err = got_error_from_errno("read");
200 		else if (n != len_ids) {
201 			err = got_error(GOT_ERR_BAD_PACKIDX);
202 			goto done;
203 		}
204 	}
205 	if (verify)
206 		SHA1Update(&ctx, (uint8_t *)h->sorted_ids, len_ids);
207 	offset += len_ids;
208 	remain -= len_ids;
209 
210 	if (remain < nobj * sizeof(*h->crc32)) {
211 		err = got_error(GOT_ERR_BAD_PACKIDX);
212 		goto done;
213 	}
214 	if (p->map)
215 		h->crc32 = (uint32_t *)((uint8_t*)(p->map + offset));
216 	else {
217 		h->crc32 = malloc(nobj * sizeof(*h->crc32));
218 		if (h->crc32 == NULL) {
219 			err = got_error_from_errno("malloc");
220 			goto done;
221 		}
222 		n = read(p->fd, h->crc32, nobj * sizeof(*h->crc32));
223 		if (n < 0)
224 			err = got_error_from_errno("read");
225 		else if (n != nobj * sizeof(*h->crc32)) {
226 			err = got_error(GOT_ERR_BAD_PACKIDX);
227 			goto done;
228 		}
229 	}
230 	if (verify)
231 		SHA1Update(&ctx, (uint8_t *)h->crc32, nobj * sizeof(*h->crc32));
232 	remain -= nobj * sizeof(*h->crc32);
233 	offset += nobj * sizeof(*h->crc32);
234 
235 	if (remain < nobj * sizeof(*h->offsets)) {
236 		err = got_error(GOT_ERR_BAD_PACKIDX);
237 		goto done;
238 	}
239 	if (p->map)
240 		h->offsets = (uint32_t *)((uint8_t*)(p->map + offset));
241 	else {
242 		h->offsets = malloc(nobj * sizeof(*h->offsets));
243 		if (h->offsets == NULL) {
244 			err = got_error_from_errno("malloc");
245 			goto done;
246 		}
247 		n = read(p->fd, h->offsets, nobj * sizeof(*h->offsets));
248 		if (n < 0)
249 			err = got_error_from_errno("read");
250 		else if (n != nobj * sizeof(*h->offsets)) {
251 			err = got_error(GOT_ERR_BAD_PACKIDX);
252 			goto done;
253 		}
254 	}
255 	if (verify)
256 		SHA1Update(&ctx, (uint8_t *)h->offsets,
257 		    nobj * sizeof(*h->offsets));
258 	remain -= nobj * sizeof(*h->offsets);
259 	offset += nobj * sizeof(*h->offsets);
260 
261 	/* Large file offsets are contained only in files > 2GB. */
262 	if (verify || packfile_size > 0x7fffffff) {
263 		for (i = 0; i < nobj; i++) {
264 			uint32_t o = h->offsets[i];
265 			if (o & htobe32(GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX))
266 				p->nlargeobj++;
267 		}
268 	}
269 	if (p->nlargeobj == 0)
270 		goto checksum;
271 	else if (packfile_size <= 0x7fffffff) {
272 		err = got_error(GOT_ERR_BAD_PACKIDX);
273 		goto done;
274 	}
275 
276 	if (remain < p->nlargeobj * sizeof(*h->large_offsets)) {
277 		err = got_error(GOT_ERR_BAD_PACKIDX);
278 		goto done;
279 	}
280 	if (p->map)
281 		h->large_offsets = (uint64_t *)((uint8_t*)(p->map + offset));
282 	else {
283 		h->large_offsets = malloc(p->nlargeobj *
284 		    sizeof(*h->large_offsets));
285 		if (h->large_offsets == NULL) {
286 			err = got_error_from_errno("malloc");
287 			goto done;
288 		}
289 		n = read(p->fd, h->large_offsets,
290 		    p->nlargeobj * sizeof(*h->large_offsets));
291 		if (n < 0)
292 			err = got_error_from_errno("read");
293 		else if (n != p->nlargeobj * sizeof(*h->large_offsets)) {
294 			err = got_error(GOT_ERR_BAD_PACKIDX);
295 			goto done;
296 		}
297 	}
298 	if (verify)
299 		SHA1Update(&ctx, (uint8_t*)h->large_offsets,
300 		    p->nlargeobj * sizeof(*h->large_offsets));
301 	remain -= p->nlargeobj * sizeof(*h->large_offsets);
302 	offset += p->nlargeobj * sizeof(*h->large_offsets);
303 
304 checksum:
305 	if (remain < sizeof(*h->trailer)) {
306 		err = got_error(GOT_ERR_BAD_PACKIDX);
307 		goto done;
308 	}
309 	if (p->map)
310 		h->trailer =
311 		    (struct got_packidx_trailer *)((uint8_t*)(p->map + offset));
312 	else {
313 		h->trailer = malloc(sizeof(*h->trailer));
314 		if (h->trailer == NULL) {
315 			err = got_error_from_errno("malloc");
316 			goto done;
317 		}
318 		n = read(p->fd, h->trailer, sizeof(*h->trailer));
319 		if (n < 0)
320 			err = got_error_from_errno("read");
321 		else if (n != sizeof(*h->trailer)) {
322 			err = got_error(GOT_ERR_BAD_PACKIDX);
323 			goto done;
324 		}
325 	}
326 	if (verify) {
327 		SHA1Update(&ctx, h->trailer->packfile_sha1, SHA1_DIGEST_LENGTH);
328 		SHA1Final(sha1, &ctx);
329 		if (memcmp(h->trailer->packidx_sha1, sha1,
330 		    SHA1_DIGEST_LENGTH) != 0)
331 			err = got_error(GOT_ERR_PACKIDX_CSUM);
332 	}
333 done:
334 	return err;
335 }
336 
337 const struct got_error *
338 got_packidx_open(struct got_packidx **packidx,
339     int dir_fd, const char *relpath, int verify)
340 {
341 	const struct got_error *err = NULL;
342 	struct got_packidx *p = NULL;
343 	char *pack_relpath;
344 	struct stat idx_sb, pack_sb;
345 
346 	*packidx = NULL;
347 
348 	err = got_packidx_get_packfile_path(&pack_relpath, relpath);
349 	if (err)
350 		return err;
351 
352 	/*
353 	 * Ensure that a corresponding pack file exists.
354 	 * Some Git repositories have this problem. Git seems to ignore
355 	 * the existence of lonely pack index files but we do not.
356 	 */
357 	if (fstatat(dir_fd, pack_relpath, &pack_sb, 0) == -1) {
358 		if (errno == ENOENT) {
359 			err = got_error_fmt(GOT_ERR_LONELY_PACKIDX,
360 			    "%s", relpath);
361 		} else
362 			err = got_error_from_errno2("fstatat", pack_relpath);
363 		goto done;
364 	}
365 
366 	p = calloc(1, sizeof(*p));
367 	if (p == NULL) {
368 		err = got_error_from_errno("calloc");
369 		goto done;
370 	}
371 
372 	p->fd = openat(dir_fd, relpath, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
373 	if (p->fd == -1) {
374 		err = got_error_from_errno2("openat", relpath);
375 		goto done;
376 	}
377 
378 	if (fstat(p->fd, &idx_sb) != 0) {
379 		err = got_error_from_errno2("fstat", relpath);
380 		goto done;
381 	}
382 	p->len = idx_sb.st_size;
383 	if (p->len < sizeof(p->hdr)) {
384 		err = got_error(GOT_ERR_BAD_PACKIDX);
385 		goto done;
386 	}
387 
388 	p->path_packidx = strdup(relpath);
389 	if (p->path_packidx == NULL) {
390 		err = got_error_from_errno("strdup");
391 		goto done;
392 	}
393 
394 #ifndef GOT_PACK_NO_MMAP
395 	if (p->len > 0 && p->len <= SIZE_MAX) {
396 		p->map = mmap(NULL, p->len, PROT_READ, MAP_PRIVATE, p->fd, 0);
397 		if (p->map == MAP_FAILED) {
398 			if (errno != ENOMEM) {
399 				err = got_error_from_errno("mmap");
400 				goto done;
401 			}
402 			p->map = NULL; /* fall back to read(2) */
403 		}
404 	}
405 #endif
406 
407 	err = got_packidx_init_hdr(p, verify, pack_sb.st_size);
408 done:
409 	if (err) {
410 		if (p)
411 			got_packidx_close(p);
412 	} else
413 		*packidx = p;
414 	free(pack_relpath);
415 	return err;
416 }
417 
418 const struct got_error *
419 got_packidx_close(struct got_packidx *packidx)
420 {
421 	const struct got_error *err = NULL;
422 
423 	free(packidx->path_packidx);
424 	if (packidx->map) {
425 		if (munmap(packidx->map, packidx->len) == -1)
426 			err = got_error_from_errno("munmap");
427 	} else {
428 		free(packidx->hdr.magic);
429 		free(packidx->hdr.version);
430 		free(packidx->hdr.fanout_table);
431 		free(packidx->hdr.sorted_ids);
432 		free(packidx->hdr.crc32);
433 		free(packidx->hdr.offsets);
434 		free(packidx->hdr.large_offsets);
435 		free(packidx->hdr.trailer);
436 	}
437 	if (close(packidx->fd) == -1 && err == NULL)
438 		err = got_error_from_errno("close");
439 	free(packidx->sorted_offsets);
440 	free(packidx->sorted_large_offsets);
441 	free(packidx);
442 
443 	return err;
444 }
445 
446 const struct got_error *
447 got_packidx_get_packfile_path(char **path_packfile, const char *path_packidx)
448 {
449 	size_t size;
450 
451 	/* Packfile path contains ".pack" instead of ".idx", so add one byte. */
452 	size = strlen(path_packidx) + 2;
453 	if (size < GOT_PACKFILE_NAMELEN + 1)
454 		return got_error_path(path_packidx, GOT_ERR_BAD_PATH);
455 
456 	*path_packfile = malloc(size);
457 	if (*path_packfile == NULL)
458 		return got_error_from_errno("malloc");
459 
460 	/* Copy up to and excluding ".idx". */
461 	if (strlcpy(*path_packfile, path_packidx,
462 	    size - strlen(GOT_PACKIDX_SUFFIX) - 1) >= size)
463 		return got_error(GOT_ERR_NO_SPACE);
464 
465 	if (strlcat(*path_packfile, GOT_PACKFILE_SUFFIX, size) >= size)
466 		return got_error(GOT_ERR_NO_SPACE);
467 
468 	return NULL;
469 }
470 
471 off_t
472 got_packidx_get_object_offset(struct got_packidx *packidx, int idx)
473 {
474 	uint32_t offset = be32toh(packidx->hdr.offsets[idx]);
475 	if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
476 		uint64_t loffset;
477 		idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
478 		if (idx < 0 || idx >= packidx->nlargeobj ||
479 		    packidx->hdr.large_offsets == NULL)
480 			return -1;
481 		loffset = be64toh(packidx->hdr.large_offsets[idx]);
482 		return (loffset > INT64_MAX ? -1 : (off_t)loffset);
483 	}
484 	return (off_t)(offset & GOT_PACKIDX_OFFSET_VAL_MASK);
485 }
486 
487 int
488 got_packidx_get_object_idx(struct got_packidx *packidx,
489     struct got_object_id *id)
490 {
491 	u_int8_t id0 = id->sha1[0];
492 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
493 	int left = 0, right = totobj - 1;
494 
495 	if (id0 > 0)
496 		left = be32toh(packidx->hdr.fanout_table[id0 - 1]);
497 
498 	while (left <= right) {
499 		struct got_packidx_object_id *oid;
500 		int i, cmp;
501 
502 		i = ((left + right) / 2);
503 		oid = &packidx->hdr.sorted_ids[i];
504 		cmp = memcmp(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
505 		if (cmp == 0)
506 			return i;
507 		else if (cmp > 0)
508 			left = i + 1;
509 		else if (cmp < 0)
510 			right = i - 1;
511 	}
512 
513 	return -1;
514 }
515 
516 static int
517 offset_cmp(const void *pa, const void *pb)
518 {
519 	const struct got_pack_offset_index *a, *b;
520 
521 	a = (const struct got_pack_offset_index *)pa;
522 	b = (const struct got_pack_offset_index *)pb;
523 
524 	if (a->offset < b->offset)
525 		return -1;
526 	else if (a->offset > b->offset)
527 		return 1;
528 
529 	return 0;
530 }
531 
532 static int
533 large_offset_cmp(const void *pa, const void *pb)
534 {
535 	const struct got_pack_large_offset_index *a, *b;
536 
537 	a = (const struct got_pack_large_offset_index *)pa;
538 	b = (const struct got_pack_large_offset_index *)pb;
539 
540 	if (a->offset < b->offset)
541 		return -1;
542 	else if (a->offset > b->offset)
543 		return 1;
544 
545 	return 0;
546 }
547 
548 static const struct got_error *
549 build_offset_index(struct got_packidx *p)
550 {
551 	uint32_t nobj = be32toh(p->hdr.fanout_table[0xff]);
552 	unsigned int i, j, k;
553 
554 	p->sorted_offsets = calloc(nobj - p->nlargeobj,
555 	    sizeof(p->sorted_offsets[0]));
556 	if (p->sorted_offsets == NULL)
557 		return got_error_from_errno("calloc");
558 
559 	if (p->nlargeobj > 0) {
560 		p->sorted_large_offsets = calloc(p->nlargeobj,
561 		    sizeof(p->sorted_large_offsets[0]));
562 		if (p->sorted_large_offsets == NULL)
563 			return got_error_from_errno("calloc");
564 	}
565 
566 	j = 0;
567 	k = 0;
568 	for (i = 0; i < nobj; i++) {
569 		uint32_t offset = be32toh(p->hdr.offsets[i]);
570 		if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
571 			uint64_t loffset;
572 			uint32_t idx;
573 			idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
574 			if (idx >= p->nlargeobj ||
575 			    p->nlargeobj == 0 ||
576 			    p->hdr.large_offsets == NULL)
577 				return got_error(GOT_ERR_BAD_PACKIDX);
578 			loffset = be64toh(p->hdr.large_offsets[idx]);
579 			p->sorted_large_offsets[j].offset = loffset;
580 			p->sorted_large_offsets[j].idx = i;
581 			j++;
582 		} else {
583 			p->sorted_offsets[k].offset = offset;
584 			p->sorted_offsets[k].idx = i;
585 			k++;
586 		}
587 	}
588 	if (j != p->nlargeobj || k != nobj - p->nlargeobj)
589 		return got_error(GOT_ERR_BAD_PACKIDX);
590 
591 	qsort(p->sorted_offsets, nobj - p->nlargeobj,
592 	    sizeof(p->sorted_offsets[0]), offset_cmp);
593 
594 	if (p->sorted_large_offsets)
595 		qsort(p->sorted_large_offsets, p->nlargeobj,
596 		    sizeof(p->sorted_large_offsets[0]), large_offset_cmp);
597 
598 	return NULL;
599 }
600 
601 const struct got_error *
602 got_packidx_get_offset_idx(int *idx, struct got_packidx *packidx, off_t offset)
603 {
604 	const struct got_error *err;
605 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
606 	int i, left, right;
607 
608 	*idx = -1;
609 
610 	if (packidx->sorted_offsets == NULL) {
611 		err = build_offset_index(packidx);
612 		if (err)
613 			return err;
614 	}
615 
616 	if (offset >= 0x7fffffff) {
617 		uint64_t lo;
618 		left = 0, right = packidx->nlargeobj - 1;
619 		while (left <= right) {
620 			i = ((left + right) / 2);
621 			lo = packidx->sorted_large_offsets[i].offset;
622 			if (lo == offset) {
623 				*idx = packidx->sorted_large_offsets[i].idx;
624 				break;
625 			} else if (offset > lo)
626 				left = i + 1;
627 			else if (offset < lo)
628 				right = i - 1;
629 		}
630 	} else {
631 		uint32_t o;
632 		left = 0, right = totobj - packidx->nlargeobj - 1;
633 		while (left <= right) {
634 			i = ((left + right) / 2);
635 			o = packidx->sorted_offsets[i].offset;
636 			if (o == offset) {
637 				*idx = packidx->sorted_offsets[i].idx;
638 				break;
639 			} else if (offset > o)
640 				left = i + 1;
641 			else if (offset < o)
642 				right = i - 1;
643 		}
644 	}
645 
646 	return NULL;
647 }
648 
649 const struct got_error *
650 got_packidx_get_object_id(struct got_object_id *id,
651     struct got_packidx *packidx, int idx)
652 {
653 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
654 	struct got_packidx_object_id *oid;
655 
656 	if (idx < 0 || idx >= totobj)
657 		return got_error(GOT_ERR_NO_OBJ);
658 
659 	oid = &packidx->hdr.sorted_ids[idx];
660 	memcpy(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
661 	return NULL;
662 }
663 
664 const struct got_error *
665 got_packidx_match_id_str_prefix(struct got_object_id_queue *matched_ids,
666     struct got_packidx *packidx, const char *id_str_prefix)
667 {
668 	const struct got_error *err = NULL;
669 	u_int8_t id0;
670 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
671 	char hex[3];
672 	size_t prefix_len = strlen(id_str_prefix);
673 	struct got_packidx_object_id *oid;
674 	uint32_t i = 0;
675 
676 	STAILQ_INIT(matched_ids);
677 
678 	if (prefix_len < 2)
679 		return got_error_path(id_str_prefix, GOT_ERR_BAD_OBJ_ID_STR);
680 
681 	hex[0] = id_str_prefix[0];
682 	hex[1] = id_str_prefix[1];
683 	hex[2] = '\0';
684 	if (!got_parse_xdigit(&id0, hex))
685 		return got_error_path(id_str_prefix, GOT_ERR_BAD_OBJ_ID_STR);
686 
687 	if (id0 > 0)
688 		i = be32toh(packidx->hdr.fanout_table[id0 - 1]);
689 	oid = &packidx->hdr.sorted_ids[i];
690 	while (i < totobj && oid->sha1[0] == id0) {
691 		char id_str[SHA1_DIGEST_STRING_LENGTH];
692 		struct got_object_qid *qid;
693 		int cmp;
694 
695 		if (!got_sha1_digest_to_str(oid->sha1, id_str, sizeof(id_str)))
696 		        return got_error(GOT_ERR_NO_SPACE);
697 
698 		cmp = strncmp(id_str, id_str_prefix, prefix_len);
699 		if (cmp < 0) {
700 			oid = &packidx->hdr.sorted_ids[++i];
701 			continue;
702 		} else if (cmp > 0)
703 			break;
704 
705 		err = got_object_qid_alloc_partial(&qid);
706 		if (err)
707 			break;
708 		memcpy(qid->id.sha1, oid->sha1, SHA1_DIGEST_LENGTH);
709 		STAILQ_INSERT_TAIL(matched_ids, qid, entry);
710 
711 		oid = &packidx->hdr.sorted_ids[++i];
712 	}
713 
714 	if (err)
715 		got_object_id_queue_free(matched_ids);
716 	return err;
717 }
718 
719 static void
720 set_max_datasize(void)
721 {
722 	struct rlimit rl;
723 
724 	if (getrlimit(RLIMIT_DATA, &rl) != 0)
725 		return;
726 
727 	rl.rlim_cur = rl.rlim_max;
728 	setrlimit(RLIMIT_DATA, &rl);
729 }
730 
731 const struct got_error *
732 got_pack_start_privsep_child(struct got_pack *pack, struct got_packidx *packidx)
733 {
734 	const struct got_error *err = NULL;
735 	int imsg_fds[2];
736 	pid_t pid;
737 	struct imsgbuf *ibuf;
738 
739 	ibuf = calloc(1, sizeof(*ibuf));
740 	if (ibuf == NULL)
741 		return got_error_from_errno("calloc");
742 
743 	pack->privsep_child = calloc(1, sizeof(*pack->privsep_child));
744 	if (pack->privsep_child == NULL) {
745 		err = got_error_from_errno("calloc");
746 		free(ibuf);
747 		return err;
748 	}
749 	pack->child_has_tempfiles = 0;
750 	pack->child_has_delta_outfd = 0;
751 
752 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
753 		err = got_error_from_errno("socketpair");
754 		goto done;
755 	}
756 
757 	pid = fork();
758 	if (pid == -1) {
759 		err = got_error_from_errno("fork");
760 		goto done;
761 	} else if (pid == 0) {
762 		set_max_datasize();
763 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PACK,
764 		    pack->path_packfile);
765 		/* not reached */
766 	}
767 
768 	if (close(imsg_fds[1]) == -1)
769 		return got_error_from_errno("close");
770 	pack->privsep_child->imsg_fd = imsg_fds[0];
771 	pack->privsep_child->pid = pid;
772 	imsg_init(ibuf, imsg_fds[0]);
773 	pack->privsep_child->ibuf = ibuf;
774 
775 	err = got_privsep_init_pack_child(ibuf, pack, packidx);
776 	if (err) {
777 		const struct got_error *child_err;
778 		err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
779 		child_err = got_privsep_wait_for_child(
780 		    pack->privsep_child->pid);
781 		if (child_err && err == NULL)
782 			err = child_err;
783 	}
784 done:
785 	if (err) {
786 		free(ibuf);
787 		free(pack->privsep_child);
788 		pack->privsep_child = NULL;
789 	}
790 	return err;
791 }
792 
793 static const struct got_error *
794 pack_stop_privsep_child(struct got_pack *pack)
795 {
796 	const struct got_error *err = NULL, *close_err = NULL;
797 
798 	if (pack->privsep_child == NULL)
799 		return NULL;
800 
801 	err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
802 	if (err)
803 		return err;
804 	if (close(pack->privsep_child->imsg_fd) == -1)
805 		close_err = got_error_from_errno("close");
806 	err = got_privsep_wait_for_child(pack->privsep_child->pid);
807 	if (close_err && err == NULL)
808 		err = close_err;
809 	imsg_clear(pack->privsep_child->ibuf);
810 	free(pack->privsep_child->ibuf);
811 	free(pack->privsep_child);
812 	pack->privsep_child = NULL;
813 	return err;
814 }
815 
816 const struct got_error *
817 got_pack_close(struct got_pack *pack)
818 {
819 	const struct got_error *err = NULL;
820 
821 	err = pack_stop_privsep_child(pack);
822 	if (pack->map && munmap(pack->map, pack->filesize) == -1 && !err)
823 		err = got_error_from_errno("munmap");
824 	if (pack->fd != -1 && close(pack->fd) == -1 && err == NULL)
825 		err = got_error_from_errno("close");
826 	pack->fd = -1;
827 	free(pack->path_packfile);
828 	pack->path_packfile = NULL;
829 	pack->filesize = 0;
830 	if (pack->delta_cache) {
831 		got_delta_cache_free(pack->delta_cache);
832 		pack->delta_cache = NULL;
833 	}
834 
835 	/*
836 	 * Leave accumfd and basefd alone. They are managed by the
837 	 * repository layer and can be reused.
838 	 */
839 
840 	return err;
841 }
842 
843 const struct got_error *
844 got_pack_parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len,
845     struct got_pack *pack, off_t offset)
846 {
847 	uint8_t t = 0;
848 	uint64_t s = 0;
849 	uint8_t sizeN;
850 	size_t mapoff = 0;
851 	int i = 0;
852 
853 	*len = 0;
854 
855 	if (offset >= pack->filesize)
856 		return got_error(GOT_ERR_PACK_OFFSET);
857 
858 	if (pack->map) {
859 		if (offset > SIZE_MAX) {
860 			return got_error_fmt(GOT_ERR_PACK_OFFSET,
861 			    "offset %lld overflows size_t",
862 			    (long long)offset);
863 		}
864 
865 		mapoff = (size_t)offset;
866 	} else {
867 		if (lseek(pack->fd, offset, SEEK_SET) == -1)
868 			return got_error_from_errno("lseek");
869 	}
870 
871 	do {
872 		/* We do not support size values which don't fit in 64 bit. */
873 		if (i > 9)
874 			return got_error_fmt(GOT_ERR_OBJ_TOO_LARGE,
875 			    "packfile offset %lld", (long long)offset);
876 
877 		if (pack->map) {
878 			if (mapoff + sizeof(sizeN) >= pack->filesize)
879 				return got_error(GOT_ERR_BAD_PACKFILE);
880 			sizeN = *(pack->map + mapoff);
881 			mapoff += sizeof(sizeN);
882 		} else {
883 			ssize_t n = read(pack->fd, &sizeN, sizeof(sizeN));
884 			if (n < 0)
885 				return got_error_from_errno("read");
886 			if (n != sizeof(sizeN))
887 				return got_error(GOT_ERR_BAD_PACKFILE);
888 		}
889 		*len += sizeof(sizeN);
890 
891 		if (i == 0) {
892 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
893 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
894 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
895 		} else {
896 			size_t shift = 4 + 7 * (i - 1);
897 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
898 		}
899 		i++;
900 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
901 
902 	*type = t;
903 	*size = s;
904 	return NULL;
905 }
906 
907 static const struct got_error *
908 open_plain_object(struct got_object **obj, struct got_object_id *id,
909     uint8_t type, off_t offset, size_t size, int idx)
910 {
911 	*obj = calloc(1, sizeof(**obj));
912 	if (*obj == NULL)
913 		return got_error_from_errno("calloc");
914 
915 	(*obj)->type = type;
916 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
917 	(*obj)->pack_idx = idx;
918 	(*obj)->hdrlen = 0;
919 	(*obj)->size = size;
920 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
921 	(*obj)->pack_offset = offset;
922 
923 	return NULL;
924 }
925 
926 static const struct got_error *
927 parse_negative_offset(int64_t *offset, size_t *len, struct got_pack *pack,
928     off_t delta_offset)
929 {
930 	int64_t o = 0;
931 	uint8_t offN;
932 	int i = 0;
933 
934 	*offset = 0;
935 	*len = 0;
936 
937 	do {
938 		/* We do not support offset values which don't fit in 64 bit. */
939 		if (i > 8)
940 			return got_error(GOT_ERR_NO_SPACE);
941 
942 		if (pack->map) {
943 			size_t mapoff;
944 
945 			if (delta_offset + *len > SIZE_MAX) {
946 				return got_error_fmt(GOT_ERR_PACK_OFFSET,
947 				    "mapoff %lld would overflow size_t",
948 				    (long long)delta_offset + *len);
949 			}
950 
951 			mapoff = (size_t)delta_offset + *len;
952 			if (mapoff + sizeof(offN) >= pack->filesize)
953 				return got_error(GOT_ERR_PACK_OFFSET);
954 			offN = *(pack->map + mapoff);
955 		} else {
956 			ssize_t n;
957 			n = read(pack->fd, &offN, sizeof(offN));
958 			if (n < 0)
959 				return got_error_from_errno("read");
960 			if (n != sizeof(offN))
961 				return got_error(GOT_ERR_BAD_PACKFILE);
962 		}
963 		*len += sizeof(offN);
964 
965 		if (i == 0)
966 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
967 		else {
968 			o++;
969 			o <<= 7;
970 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
971 		}
972 		i++;
973 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
974 
975 	*offset = o;
976 	return NULL;
977 }
978 
979 const struct got_error *
980 got_pack_parse_offset_delta(off_t *base_offset, size_t *len,
981     struct got_pack *pack, off_t offset, size_t tslen)
982 {
983 	const struct got_error *err;
984 	int64_t negoffset;
985 	size_t negofflen;
986 
987 	*len = 0;
988 
989 	err = parse_negative_offset(&negoffset, &negofflen, pack,
990 	    offset + tslen);
991 	if (err)
992 		return err;
993 
994 	/* Compute the base object's offset (must be in the same pack file). */
995 	*base_offset = (offset - negoffset);
996 	if (*base_offset <= 0)
997 		return got_error(GOT_ERR_BAD_PACKFILE);
998 
999 	*len = negofflen;
1000 	return NULL;
1001 }
1002 
1003 static const struct got_error *
1004 read_delta_data(uint8_t **delta_buf, size_t *delta_len,
1005     size_t *delta_compressed_len, size_t delta_data_offset,
1006     struct got_pack *pack)
1007 {
1008 	const struct got_error *err = NULL;
1009 	size_t consumed = 0;
1010 
1011 	if (pack->map) {
1012 		if (delta_data_offset >= pack->filesize)
1013 			return got_error(GOT_ERR_PACK_OFFSET);
1014 		err = got_inflate_to_mem_mmap(delta_buf, delta_len,
1015 		    &consumed, NULL, pack->map, delta_data_offset,
1016 		    pack->filesize - delta_data_offset);
1017 		if (err)
1018 			return err;
1019 	} else {
1020 		if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1)
1021 			return got_error_from_errno("lseek");
1022 		err = got_inflate_to_mem_fd(delta_buf, delta_len,
1023 		    &consumed, NULL, 0, pack->fd);
1024 		if (err)
1025 			return err;
1026 	}
1027 
1028 	if (delta_compressed_len)
1029 		*delta_compressed_len = consumed;
1030 
1031 	return NULL;
1032 }
1033 
1034 static const struct got_error *
1035 add_delta(struct got_delta_chain *deltas, off_t delta_offset, size_t tslen,
1036     int delta_type, size_t delta_size, off_t delta_data_offset)
1037 {
1038 	struct got_delta *delta;
1039 
1040 	delta = got_delta_open(delta_offset, tslen, delta_type, delta_size,
1041 	    delta_data_offset);
1042 	if (delta == NULL)
1043 		return got_error_from_errno("got_delta_open");
1044 	/* delta is freed in got_object_close() */
1045 	deltas->nentries++;
1046 	STAILQ_INSERT_HEAD(&deltas->entries, delta, entry);
1047 	return NULL;
1048 }
1049 
1050 static const struct got_error *
1051 resolve_offset_delta(struct got_delta_chain *deltas,
1052     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
1053     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
1054 {
1055 	const struct got_error *err;
1056 	off_t base_offset;
1057 	uint8_t base_type;
1058 	uint64_t base_size;
1059 	size_t base_tslen;
1060 	off_t delta_data_offset;
1061 	size_t consumed;
1062 
1063 	err = got_pack_parse_offset_delta(&base_offset, &consumed, pack,
1064 	    delta_offset, tslen);
1065 	if (err)
1066 		return err;
1067 
1068 	delta_data_offset = delta_offset + tslen + consumed;
1069 	if (delta_data_offset >= pack->filesize)
1070 		return got_error(GOT_ERR_PACK_OFFSET);
1071 
1072 	if (pack->map == NULL) {
1073 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
1074 		if (delta_data_offset == -1)
1075 			return got_error_from_errno("lseek");
1076 	}
1077 
1078 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
1079 	    delta_data_offset);
1080 	if (err)
1081 		return err;
1082 
1083 	/* An offset delta must be in the same packfile. */
1084 	if (base_offset >= pack->filesize)
1085 		return got_error(GOT_ERR_PACK_OFFSET);
1086 
1087 	err = got_pack_parse_object_type_and_size(&base_type, &base_size,
1088 	    &base_tslen, pack, base_offset);
1089 	if (err)
1090 		return err;
1091 
1092 	return got_pack_resolve_delta_chain(deltas, packidx, pack, base_offset,
1093 	    base_tslen, base_type, base_size, recursion - 1);
1094 }
1095 
1096 const struct got_error *
1097 got_pack_parse_ref_delta(struct got_object_id *id,
1098     struct got_pack *pack, off_t delta_offset, int tslen)
1099 {
1100 	if (pack->map) {
1101 		size_t mapoff;
1102 
1103 		if (delta_offset + tslen > SIZE_MAX) {
1104 			return got_error_fmt(GOT_ERR_PACK_OFFSET,
1105 			    "mapoff %lld would overflow size_t",
1106 			    (long long)delta_offset + tslen);
1107 		}
1108 
1109 		mapoff = delta_offset + tslen;
1110 		if (mapoff + sizeof(*id) >= pack->filesize)
1111 			return got_error(GOT_ERR_PACK_OFFSET);
1112 		memcpy(id, pack->map + mapoff, sizeof(*id));
1113 	} else {
1114 		ssize_t n;
1115 		n = read(pack->fd, id, sizeof(*id));
1116 		if (n < 0)
1117 			return got_error_from_errno("read");
1118 		if (n != sizeof(*id))
1119 			return got_error(GOT_ERR_BAD_PACKFILE);
1120 	}
1121 
1122 	return NULL;
1123 }
1124 
1125 static const struct got_error *
1126 resolve_ref_delta(struct got_delta_chain *deltas, struct got_packidx *packidx,
1127     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
1128     size_t delta_size, unsigned int recursion)
1129 {
1130 	const struct got_error *err;
1131 	struct got_object_id id;
1132 	int idx;
1133 	off_t base_offset;
1134 	uint8_t base_type;
1135 	uint64_t base_size;
1136 	size_t base_tslen;
1137 	off_t delta_data_offset;
1138 
1139 	if (delta_offset + tslen >= pack->filesize)
1140 		return got_error(GOT_ERR_PACK_OFFSET);
1141 
1142 	err = got_pack_parse_ref_delta(&id, pack, delta_offset, tslen);
1143 	if (err)
1144 		return err;
1145 	if (pack->map) {
1146 		delta_data_offset = delta_offset + tslen + sizeof(id);
1147 	} else {
1148 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
1149 		if (delta_data_offset == -1)
1150 			return got_error_from_errno("lseek");
1151 	}
1152 
1153 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
1154 	    delta_data_offset);
1155 	if (err)
1156 		return err;
1157 
1158 	/* Delta base must be in the same pack file. */
1159 	idx = got_packidx_get_object_idx(packidx, &id);
1160 	if (idx == -1)
1161 		return got_error(GOT_ERR_NO_OBJ);
1162 
1163 	base_offset = got_packidx_get_object_offset(packidx, idx);
1164 	if (base_offset == -1)
1165 		return got_error(GOT_ERR_BAD_PACKIDX);
1166 
1167 	if (base_offset >= pack->filesize)
1168 		return got_error(GOT_ERR_PACK_OFFSET);
1169 
1170 	err = got_pack_parse_object_type_and_size(&base_type, &base_size,
1171 	    &base_tslen, pack, base_offset);
1172 	if (err)
1173 		return err;
1174 
1175 	return got_pack_resolve_delta_chain(deltas, packidx, pack, base_offset,
1176 	    base_tslen, base_type, base_size, recursion - 1);
1177 }
1178 
1179 const struct got_error *
1180 got_pack_resolve_delta_chain(struct got_delta_chain *deltas,
1181     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
1182     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
1183 {
1184 	const struct got_error *err = NULL;
1185 
1186 	if (--recursion == 0)
1187 		return got_error(GOT_ERR_RECURSION);
1188 
1189 	switch (delta_type) {
1190 	case GOT_OBJ_TYPE_COMMIT:
1191 	case GOT_OBJ_TYPE_TREE:
1192 	case GOT_OBJ_TYPE_BLOB:
1193 	case GOT_OBJ_TYPE_TAG:
1194 		/* Plain types are the final delta base. Recursion ends. */
1195 		err = add_delta(deltas, delta_offset, tslen, delta_type,
1196 		    delta_size, 0);
1197 		break;
1198 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1199 		err = resolve_offset_delta(deltas, packidx, pack,
1200 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
1201 		break;
1202 	case GOT_OBJ_TYPE_REF_DELTA:
1203 		err = resolve_ref_delta(deltas, packidx, pack,
1204 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
1205 		break;
1206 	default:
1207 		return got_error(GOT_ERR_OBJ_TYPE);
1208 	}
1209 
1210 	return err;
1211 }
1212 
1213 static const struct got_error *
1214 open_delta_object(struct got_object **obj, struct got_packidx *packidx,
1215     struct got_pack *pack, struct got_object_id *id, off_t offset,
1216     size_t tslen, int delta_type, size_t delta_size, int idx)
1217 {
1218 	const struct got_error *err = NULL;
1219 	int resolved_type;
1220 
1221 	*obj = calloc(1, sizeof(**obj));
1222 	if (*obj == NULL)
1223 		return got_error_from_errno("calloc");
1224 
1225 	(*obj)->flags = 0;
1226 	(*obj)->hdrlen = 0;
1227 	(*obj)->size = 0; /* Not known because deltas aren't applied yet. */
1228 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
1229 	(*obj)->pack_offset = offset + tslen;
1230 
1231 	STAILQ_INIT(&(*obj)->deltas.entries);
1232 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
1233 	(*obj)->flags |= GOT_OBJ_FLAG_PACKED;
1234 	(*obj)->pack_idx = idx;
1235 
1236 	err = got_pack_resolve_delta_chain(&(*obj)->deltas, packidx, pack,
1237 	    offset, tslen, delta_type, delta_size,
1238 	    GOT_DELTA_CHAIN_RECURSION_MAX);
1239 	if (err)
1240 		goto done;
1241 
1242 	err = got_delta_chain_get_base_type(&resolved_type, &(*obj)->deltas);
1243 	if (err)
1244 		goto done;
1245 	(*obj)->type = resolved_type;
1246 done:
1247 	if (err) {
1248 		got_object_close(*obj);
1249 		*obj = NULL;
1250 	}
1251 	return err;
1252 }
1253 
1254 const struct got_error *
1255 got_packfile_open_object(struct got_object **obj, struct got_pack *pack,
1256     struct got_packidx *packidx, int idx, struct got_object_id *id)
1257 {
1258 	const struct got_error *err = NULL;
1259 	off_t offset;
1260 	uint8_t type;
1261 	uint64_t size;
1262 	size_t tslen;
1263 
1264 	*obj = NULL;
1265 
1266 	offset = got_packidx_get_object_offset(packidx, idx);
1267 	if (offset == -1)
1268 		return got_error(GOT_ERR_BAD_PACKIDX);
1269 
1270 	err = got_pack_parse_object_type_and_size(&type, &size, &tslen,
1271 	    pack, offset);
1272 	if (err)
1273 		return err;
1274 
1275 	switch (type) {
1276 	case GOT_OBJ_TYPE_COMMIT:
1277 	case GOT_OBJ_TYPE_TREE:
1278 	case GOT_OBJ_TYPE_BLOB:
1279 	case GOT_OBJ_TYPE_TAG:
1280 		err = open_plain_object(obj, id, type, offset + tslen,
1281 		    size, idx);
1282 		break;
1283 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1284 	case GOT_OBJ_TYPE_REF_DELTA:
1285 		err = open_delta_object(obj, packidx, pack, id, offset,
1286 		    tslen, type, size, idx);
1287 		break;
1288 	default:
1289 		err = got_error(GOT_ERR_OBJ_TYPE);
1290 		break;
1291 	}
1292 
1293 	return err;
1294 }
1295 
1296 const struct got_error *
1297 got_pack_get_delta_chain_max_size(uint64_t *max_size,
1298     struct got_delta_chain *deltas, struct got_pack *pack)
1299 {
1300 	struct got_delta *delta;
1301 	uint64_t base_size = 0, result_size = 0;
1302 
1303 	*max_size = 0;
1304 	STAILQ_FOREACH(delta, &deltas->entries, entry) {
1305 		/* Plain object types are the delta base. */
1306 		if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1307 		    delta->type != GOT_OBJ_TYPE_TREE &&
1308 		    delta->type != GOT_OBJ_TYPE_BLOB &&
1309 		    delta->type != GOT_OBJ_TYPE_TAG) {
1310 			const struct got_error *err;
1311 			uint8_t *delta_buf = NULL;
1312 			size_t delta_len;
1313 			int cached = 1;
1314 
1315 			if (pack->delta_cache) {
1316 				got_delta_cache_get(&delta_buf, &delta_len,
1317 				    pack->delta_cache, delta->data_offset);
1318 			}
1319 			if (delta_buf == NULL) {
1320 				cached = 0;
1321 				err = read_delta_data(&delta_buf, &delta_len,
1322 				    NULL, delta->data_offset, pack);
1323 				if (err)
1324 					return err;
1325 			}
1326 			if (pack->delta_cache && !cached) {
1327 				err = got_delta_cache_add(pack->delta_cache,
1328 				    delta->data_offset, delta_buf, delta_len);
1329 				if (err == NULL)
1330 					cached = 1;
1331 				else if (err->code != GOT_ERR_NO_SPACE) {
1332 					free(delta_buf);
1333 					return err;
1334 				}
1335 			}
1336 			err = got_delta_get_sizes(&base_size, &result_size,
1337 			    delta_buf, delta_len);
1338 			if (!cached)
1339 				free(delta_buf);
1340 			if (err)
1341 				return err;
1342 		} else
1343 			base_size = delta->size;
1344 		if (base_size > *max_size)
1345 			*max_size = base_size;
1346 		if (result_size > *max_size)
1347 			*max_size = result_size;
1348 	}
1349 
1350 	return NULL;
1351 }
1352 
1353 const struct got_error *
1354 got_pack_get_max_delta_object_size(uint64_t *size, struct got_object *obj,
1355     struct got_pack *pack)
1356 {
1357 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0)
1358 		return got_error(GOT_ERR_OBJ_TYPE);
1359 
1360 	return got_pack_get_delta_chain_max_size(size, &obj->deltas, pack);
1361 }
1362 
1363 const struct got_error *
1364 got_pack_dump_delta_chain_to_file(size_t *result_size,
1365     struct got_delta_chain *deltas, struct got_pack *pack, FILE *outfile,
1366     FILE *base_file, FILE *accum_file)
1367 {
1368 	const struct got_error *err = NULL;
1369 	struct got_delta *delta;
1370 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1371 	size_t base_bufsz = 0, accum_bufsz = 0, accum_size = 0, delta_len;
1372 	/* We process small enough files entirely in memory for speed. */
1373 	const size_t max_bufsize = GOT_DELTA_RESULT_SIZE_CACHED_MAX;
1374 	uint64_t max_size = 0;
1375 	int n = 0;
1376 
1377 	*result_size = 0;
1378 
1379 	if (STAILQ_EMPTY(&deltas->entries))
1380 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1381 
1382 	if (fseeko(base_file, 0L, SEEK_SET) == -1)
1383 		return got_error_from_errno("fseeko");
1384 	if (fseeko(accum_file, 0L, SEEK_SET) == -1)
1385 		return got_error_from_errno("fseeko");
1386 
1387 	/* Deltas are ordered in ascending order. */
1388 	STAILQ_FOREACH(delta, &deltas->entries, entry) {
1389 		uint8_t *delta_buf = NULL;
1390 		uint64_t base_size, result_size = 0;
1391 		int cached = 1;
1392 		if (n == 0) {
1393 			size_t mapoff;
1394 			off_t delta_data_offset;
1395 
1396 			/* Plain object types are the delta base. */
1397 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1398 			    delta->type != GOT_OBJ_TYPE_TREE &&
1399 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1400 			    delta->type != GOT_OBJ_TYPE_TAG) {
1401 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1402 				goto done;
1403 			}
1404 
1405 			delta_data_offset = delta->offset + delta->tslen;
1406 			if (delta_data_offset >= pack->filesize) {
1407 				err = got_error(GOT_ERR_PACK_OFFSET);
1408 				goto done;
1409 			}
1410 			if (pack->map == NULL) {
1411 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1412 				    == -1) {
1413 					err = got_error_from_errno("lseek");
1414 					goto done;
1415 				}
1416 			}
1417 			if (delta->size > max_size)
1418 				max_size = delta->size;
1419 			if (max_size > max_bufsize) {
1420 				if (pack->map) {
1421 					if (delta_data_offset > SIZE_MAX) {
1422 						return got_error_fmt(
1423 						    GOT_ERR_RANGE,
1424 						    "delta offset %lld "
1425 						    "overflows size_t",
1426 						    (long long)
1427 						    delta_data_offset);
1428 					}
1429 
1430 					mapoff = delta_data_offset;
1431 					err = got_inflate_to_file_mmap(
1432 					    &base_bufsz, NULL, NULL, pack->map,
1433 					    mapoff, pack->filesize - mapoff,
1434 					    base_file);
1435 				} else
1436 					err = got_inflate_to_file_fd(
1437 					    &base_bufsz, NULL, NULL, pack->fd,
1438 					    base_file);
1439 			} else {
1440 				accum_buf = malloc(max_size);
1441 				if (accum_buf == NULL) {
1442 					err = got_error_from_errno("malloc");
1443 					goto done;
1444 				}
1445 				accum_bufsz = max_size;
1446 				if (pack->map) {
1447 					if (delta_data_offset > SIZE_MAX) {
1448 						return got_error_fmt(
1449 						    GOT_ERR_RANGE,
1450 						    "delta offset %lld "
1451 						    "overflows size_t",
1452 						    (long long)
1453 						    delta_data_offset);
1454 					}
1455 
1456 					mapoff = delta_data_offset;
1457 					err = got_inflate_to_mem_mmap(&base_buf,
1458 					    &base_bufsz, NULL, NULL,
1459 					    pack->map, mapoff,
1460 					    pack->filesize - mapoff);
1461 				} else
1462 					err = got_inflate_to_mem_fd(&base_buf,
1463 					    &base_bufsz, NULL, NULL, max_size,
1464 					    pack->fd);
1465 			}
1466 			if (err)
1467 				goto done;
1468 			n++;
1469 			if (base_buf == NULL)
1470 				rewind(base_file);
1471 			continue;
1472 		}
1473 
1474 		if (pack->delta_cache) {
1475 			got_delta_cache_get(&delta_buf, &delta_len,
1476 			    pack->delta_cache, delta->data_offset);
1477 		}
1478 		if (delta_buf == NULL) {
1479 			cached = 0;
1480 			err = read_delta_data(&delta_buf, &delta_len, NULL,
1481 			    delta->data_offset, pack);
1482 			if (err)
1483 				goto done;
1484 		}
1485 		if (pack->delta_cache && !cached) {
1486 			err = got_delta_cache_add(pack->delta_cache,
1487 			    delta->data_offset, delta_buf, delta_len);
1488 			if (err == NULL)
1489 				cached = 1;
1490 			else if (err->code != GOT_ERR_NO_SPACE) {
1491 				free(delta_buf);
1492 				goto done;
1493 			}
1494 		}
1495 
1496 		err = got_delta_get_sizes(&base_size, &result_size,
1497 		    delta_buf, delta_len);
1498 		if (err)
1499 			goto done;
1500 		if (base_size > max_size)
1501 			max_size = base_size;
1502 		if (result_size > max_size)
1503 			max_size = result_size;
1504 
1505 		if (base_buf && max_size > max_bufsize) {
1506 			/* Switch from buffers to temporary files. */
1507 			size_t w = fwrite(base_buf, 1, base_bufsz,
1508 			    base_file);
1509 			if (w != base_bufsz) {
1510 				err = got_ferror(outfile, GOT_ERR_IO);
1511 				goto done;
1512 			}
1513 			free(base_buf);
1514 			base_buf = NULL;
1515 			free(accum_buf);
1516 			accum_buf = NULL;
1517 		}
1518 
1519 		if (base_buf && max_size > base_bufsz) {
1520 			uint8_t *p = realloc(base_buf, max_size);
1521 			if (p == NULL) {
1522 				err = got_error_from_errno("realloc");
1523 				goto done;
1524 			}
1525 			base_buf = p;
1526 			base_bufsz = max_size;
1527 		}
1528 
1529 		if (accum_buf && max_size > accum_bufsz) {
1530 			uint8_t *p = realloc(accum_buf, max_size);
1531 			if (p == NULL) {
1532 				err = got_error_from_errno("realloc");
1533 				goto done;
1534 			}
1535 			accum_buf = p;
1536 			accum_bufsz = max_size;
1537 		}
1538 
1539 		if (base_buf) {
1540 			err = got_delta_apply_in_mem(base_buf, base_bufsz,
1541 			    delta_buf, delta_len, accum_buf,
1542 			    &accum_size, max_size);
1543 			n++;
1544 		} else {
1545 			err = got_delta_apply(base_file, delta_buf,
1546 			    delta_len,
1547 			    /* Final delta application writes to output file. */
1548 			    ++n < deltas->nentries ? accum_file : outfile,
1549 			    &accum_size);
1550 		}
1551 		if (!cached)
1552 			free(delta_buf);
1553 		if (err)
1554 			goto done;
1555 
1556 		if (n < deltas->nentries) {
1557 			/* Accumulated delta becomes the new base. */
1558 			if (base_buf) {
1559 				uint8_t *tmp = accum_buf;
1560 				size_t tmp_size = accum_bufsz;
1561 				accum_buf = base_buf;
1562 				accum_bufsz = base_bufsz;
1563 				base_buf = tmp;
1564 				base_bufsz = tmp_size;
1565 			} else {
1566 				FILE *tmp = accum_file;
1567 				accum_file = base_file;
1568 				base_file = tmp;
1569 				rewind(base_file);
1570 				rewind(accum_file);
1571 			}
1572 		}
1573 	}
1574 
1575 done:
1576 	free(base_buf);
1577 	if (accum_buf) {
1578 		size_t len = fwrite(accum_buf, 1, accum_size, outfile);
1579 		free(accum_buf);
1580 		if (len != accum_size)
1581 			err = got_ferror(outfile, GOT_ERR_IO);
1582 	}
1583 	rewind(outfile);
1584 	if (err == NULL)
1585 		*result_size = accum_size;
1586 	return err;
1587 }
1588 
1589 const struct got_error *
1590 got_pack_dump_delta_chain_to_mem(uint8_t **outbuf, size_t *outlen,
1591     struct got_delta_chain *deltas, struct got_pack *pack)
1592 {
1593 	const struct got_error *err = NULL;
1594 	struct got_delta *delta;
1595 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1596 	size_t base_bufsz = 0, accum_bufsz = 0, accum_size = 0, delta_len;
1597 	uint64_t max_size = 0;
1598 	int n = 0;
1599 
1600 	*outbuf = NULL;
1601 	*outlen = 0;
1602 
1603 	if (STAILQ_EMPTY(&deltas->entries))
1604 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1605 
1606 	/* Deltas are ordered in ascending order. */
1607 	STAILQ_FOREACH(delta, &deltas->entries, entry) {
1608 		uint8_t *delta_buf = NULL;
1609 		uint64_t base_size, result_size = 0;
1610 		int cached = 1;
1611 		if (n == 0) {
1612 			off_t delta_data_offset;
1613 
1614 			/* Plain object types are the delta base. */
1615 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1616 			    delta->type != GOT_OBJ_TYPE_TREE &&
1617 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1618 			    delta->type != GOT_OBJ_TYPE_TAG) {
1619 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1620 				goto done;
1621 			}
1622 
1623 			delta_data_offset = delta->offset + delta->tslen;
1624 			if (delta_data_offset >= pack->filesize) {
1625 				err = got_error(GOT_ERR_PACK_OFFSET);
1626 				goto done;
1627 			}
1628 
1629 			if (delta->size > max_size)
1630 				max_size = delta->size;
1631 
1632 			if (pack->map) {
1633 				size_t mapoff;
1634 
1635 				if (delta_data_offset > SIZE_MAX) {
1636 					return got_error_fmt(GOT_ERR_RANGE,
1637 					    "delta %lld offset would "
1638 					    "overflow size_t",
1639 					    (long long)delta_data_offset);
1640 				}
1641 
1642 				mapoff = delta_data_offset;
1643 				err = got_inflate_to_mem_mmap(&base_buf,
1644 				    &base_bufsz, NULL, NULL, pack->map,
1645 				    mapoff, pack->filesize - mapoff);
1646 			} else {
1647 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1648 				    == -1) {
1649 					err = got_error_from_errno("lseek");
1650 					goto done;
1651 				}
1652 				err = got_inflate_to_mem_fd(&base_buf,
1653 				    &base_bufsz, NULL, NULL, max_size,
1654 				    pack->fd);
1655 			}
1656 			if (err)
1657 				goto done;
1658 			n++;
1659 			continue;
1660 		}
1661 
1662 		if (pack->delta_cache) {
1663 			got_delta_cache_get(&delta_buf, &delta_len,
1664 			    pack->delta_cache, delta->data_offset);
1665 		}
1666 		if (delta_buf == NULL) {
1667 			cached = 0;
1668 			err = read_delta_data(&delta_buf, &delta_len, NULL,
1669 			    delta->data_offset, pack);
1670 			if (err)
1671 				goto done;
1672 		}
1673 		if (pack->delta_cache && !cached) {
1674 			err = got_delta_cache_add(pack->delta_cache,
1675 			    delta->data_offset, delta_buf, delta_len);
1676 			if (err == NULL)
1677 				cached = 1;
1678 			else if (err->code != GOT_ERR_NO_SPACE) {
1679 				free(delta_buf);
1680 				goto done;
1681 			}
1682 		}
1683 
1684 		err = got_delta_get_sizes(&base_size, &result_size,
1685 		    delta_buf, delta_len);
1686 		if (err)
1687 			goto done;
1688 		if (base_size > max_size)
1689 			max_size = base_size;
1690 		if (result_size > max_size)
1691 			max_size = result_size;
1692 
1693 		if (max_size > base_bufsz) {
1694 			uint8_t *p = realloc(base_buf, max_size);
1695 			if (p == NULL) {
1696 				err = got_error_from_errno("realloc");
1697 				goto done;
1698 			}
1699 			base_buf = p;
1700 			base_bufsz = max_size;
1701 		}
1702 
1703 		if (max_size > accum_bufsz) {
1704 			uint8_t *p = realloc(accum_buf, max_size);
1705 			if (p == NULL) {
1706 				err = got_error_from_errno("realloc");
1707 				goto done;
1708 			}
1709 			accum_buf = p;
1710 			accum_bufsz = max_size;
1711 		}
1712 
1713 		err = got_delta_apply_in_mem(base_buf, base_bufsz,
1714 		    delta_buf, delta_len, accum_buf,
1715 		    &accum_size, max_size);
1716 		if (!cached)
1717 			free(delta_buf);
1718 		n++;
1719 		if (err)
1720 			goto done;
1721 
1722 		if (n < deltas->nentries) {
1723 			/* Accumulated delta becomes the new base. */
1724 			uint8_t *tmp = accum_buf;
1725 			size_t tmp_size = accum_bufsz;
1726 			accum_buf = base_buf;
1727 			accum_bufsz = base_bufsz;
1728 			base_buf = tmp;
1729 			base_bufsz = tmp_size;
1730 		}
1731 	}
1732 
1733 done:
1734 	free(base_buf);
1735 	if (err) {
1736 		free(accum_buf);
1737 		*outbuf = NULL;
1738 		*outlen = 0;
1739 	} else {
1740 		*outbuf = accum_buf;
1741 		*outlen = accum_size;
1742 	}
1743 	return err;
1744 }
1745 
1746 const struct got_error *
1747 got_packfile_extract_object(struct got_pack *pack, struct got_object *obj,
1748     FILE *outfile, FILE *base_file, FILE *accum_file)
1749 {
1750 	const struct got_error *err = NULL;
1751 
1752 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1753 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1754 
1755 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1756 		if (obj->pack_offset >= pack->filesize)
1757 			return got_error(GOT_ERR_PACK_OFFSET);
1758 
1759 		if (pack->map) {
1760 			size_t mapoff;
1761 
1762 			if (obj->pack_offset > SIZE_MAX) {
1763 				return got_error_fmt(GOT_ERR_RANGE,
1764 				    "pack offset %lld would overflow size_t",
1765 				    (long long)obj->pack_offset);
1766 			}
1767 
1768 			mapoff = obj->pack_offset;
1769 			err = got_inflate_to_file_mmap(&obj->size, NULL, NULL,
1770 			    pack->map, mapoff, pack->filesize - mapoff,
1771 			    outfile);
1772 		} else {
1773 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1774 				return got_error_from_errno("lseek");
1775 			err = got_inflate_to_file_fd(&obj->size, NULL, NULL,
1776 			    pack->fd, outfile);
1777 		}
1778 	} else
1779 		err = got_pack_dump_delta_chain_to_file(&obj->size,
1780 		    &obj->deltas, pack, outfile, base_file, accum_file);
1781 
1782 	return err;
1783 }
1784 
1785 const struct got_error *
1786 got_packfile_extract_object_to_mem(uint8_t **buf, size_t *len,
1787     struct got_object *obj, struct got_pack *pack)
1788 {
1789 	const struct got_error *err = NULL;
1790 
1791 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1792 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1793 
1794 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1795 		if (obj->pack_offset >= pack->filesize)
1796 			return got_error(GOT_ERR_PACK_OFFSET);
1797 		if (pack->map) {
1798 			size_t mapoff;
1799 
1800 			if (obj->pack_offset > SIZE_MAX) {
1801 				return got_error_fmt(GOT_ERR_RANGE,
1802 				    "pack offset %lld would overflow size_t",
1803 				    (long long)obj->pack_offset);
1804 			}
1805 
1806 			mapoff = obj->pack_offset;
1807 			err = got_inflate_to_mem_mmap(buf, len, NULL, NULL,
1808 			    pack->map, mapoff, pack->filesize - mapoff);
1809 		} else {
1810 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1811 				return got_error_from_errno("lseek");
1812 			err = got_inflate_to_mem_fd(buf, len, NULL, NULL,
1813 			    obj->size, pack->fd);
1814 		}
1815 	} else
1816 		err = got_pack_dump_delta_chain_to_mem(buf, len, &obj->deltas,
1817 		    pack);
1818 
1819 	return err;
1820 }
1821 
1822 static const struct got_error *
1823 read_raw_delta_data(uint8_t **delta_buf, size_t *delta_len,
1824     size_t *delta_len_compressed, uint64_t *base_size, uint64_t *result_size,
1825     off_t delta_data_offset, struct got_pack *pack, struct got_packidx *packidx)
1826 {
1827 	const struct got_error *err = NULL;
1828 
1829 	/* Validate decompression and obtain the decompressed size. */
1830 	err = read_delta_data(delta_buf, delta_len, delta_len_compressed,
1831 	    delta_data_offset, pack);
1832 	if (err)
1833 		return err;
1834 
1835 	/* Read delta base/result sizes from head of delta stream. */
1836 	err = got_delta_get_sizes(base_size, result_size,
1837 	    *delta_buf, *delta_len);
1838 	if (err)
1839 		goto done;
1840 
1841 	/* Discard decompressed delta and read it again in compressed form. */
1842 	free(*delta_buf);
1843 	*delta_buf = malloc(*delta_len_compressed);
1844 	if (*delta_buf == NULL) {
1845 		err = got_error_from_errno("malloc");
1846 		goto done;
1847 	}
1848 	if (pack->map) {
1849 		if (delta_data_offset >= pack->filesize) {
1850 			err = got_error(GOT_ERR_PACK_OFFSET);
1851 			goto done;
1852 		}
1853 		memcpy(*delta_buf, pack->map + delta_data_offset,
1854 		    *delta_len_compressed);
1855 	} else {
1856 		ssize_t n;
1857 		if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1) {
1858 			err = got_error_from_errno("lseek");
1859 			goto done;
1860 		}
1861 		n = read(pack->fd, *delta_buf, *delta_len_compressed);
1862 		if (n < 0) {
1863 			err = got_error_from_errno("read");
1864 			goto done;
1865 		} else if (n != *delta_len_compressed) {
1866 			err = got_error(GOT_ERR_IO);
1867 			goto done;
1868 		}
1869 	}
1870 done:
1871 	if (err) {
1872 		free(*delta_buf);
1873 		*delta_buf = NULL;
1874 		*delta_len = 0;
1875 		*delta_len_compressed = 0;
1876 		*base_size = 0;
1877 		*result_size = 0;
1878 	}
1879 	return err;
1880 }
1881 
1882 const struct got_error *
1883 got_packfile_extract_raw_delta(uint8_t **delta_buf, size_t *delta_size,
1884     size_t *delta_compressed_size, off_t *delta_offset, off_t *base_offset,
1885     struct got_object_id *base_id, uint64_t *base_size, uint64_t *result_size,
1886     struct got_pack *pack, struct got_packidx *packidx, int idx)
1887 {
1888 	const struct got_error *err = NULL;
1889 	off_t offset;
1890 	uint8_t type;
1891 	uint64_t size;
1892 	size_t tslen, delta_hdrlen;
1893 	off_t delta_data_offset;
1894 
1895 	*delta_buf = NULL;
1896 	*delta_size = 0;
1897 	*delta_compressed_size = 0;
1898 	*delta_offset = 0;
1899 	*base_offset = 0;
1900 	*base_size = 0;
1901 	*result_size = 0;
1902 
1903 	offset = got_packidx_get_object_offset(packidx, idx);
1904 	if (offset == -1)
1905 		return got_error(GOT_ERR_BAD_PACKIDX);
1906 
1907 	if (offset >= pack->filesize)
1908 		return got_error(GOT_ERR_PACK_OFFSET);
1909 
1910 	err = got_pack_parse_object_type_and_size(&type, &size, &tslen,
1911 	    pack, offset);
1912 	if (err)
1913 		return err;
1914 
1915 	if (tslen + size < tslen || offset + size < size ||
1916 	    tslen + offset < tslen)
1917 		return got_error(GOT_ERR_PACK_OFFSET);
1918 
1919 	switch (type) {
1920 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1921 		err = got_pack_parse_offset_delta(base_offset, &delta_hdrlen,
1922 		    pack, offset, tslen);
1923 		if (err)
1924 			return err;
1925 		break;
1926 	case GOT_OBJ_TYPE_REF_DELTA:
1927 		err = got_pack_parse_ref_delta(base_id, pack, offset, tslen);
1928 		if (err)
1929 			return err;
1930 		delta_hdrlen = SHA1_DIGEST_LENGTH;
1931 		break;
1932 	default:
1933 		return got_error_fmt(GOT_ERR_OBJ_TYPE,
1934 		    "non-delta object type %d found at offset %lld",
1935 		    type, (long long)offset);
1936 	}
1937 
1938 	if (tslen + delta_hdrlen < delta_hdrlen ||
1939 	    offset + delta_hdrlen < delta_hdrlen)
1940 		return got_error(GOT_ERR_BAD_DELTA);
1941 
1942 	delta_data_offset = offset + tslen + delta_hdrlen;
1943 	err = read_raw_delta_data(delta_buf, delta_size, delta_compressed_size,
1944 	    base_size, result_size, delta_data_offset, pack, packidx);
1945 	if (err)
1946 		return err;
1947 
1948 	if (*delta_size != size) {
1949 		err = got_error(GOT_ERR_BAD_DELTA);
1950 		goto done;
1951 	}
1952 
1953 	*delta_offset = offset;
1954 done:
1955 	if (err) {
1956 		free(*delta_buf);
1957 		*delta_buf = NULL;
1958 		*delta_size = 0;
1959 		*delta_compressed_size = 0;
1960 		*delta_offset = 0;
1961 		*base_offset = 0;
1962 		*base_size = 0;
1963 		*result_size = 0;
1964 	}
1965 	return err;
1966 }