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 <unistd.h>
33 #include <zlib.h>
34 
35 #include "got_error.h"
36 #include "got_object.h"
37 #include "got_path.h"
38 
39 #include "got_lib_sha1.h"
40 #include "got_lib_delta.h"
41 #include "got_lib_delta_cache.h"
42 #include "got_lib_inflate.h"
43 #include "got_lib_object.h"
44 #include "got_lib_object_parse.h"
45 #include "got_lib_privsep.h"
46 #include "got_lib_pack.h"
47 
48 #ifndef nitems
49 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
50 #endif
51 
52 #ifndef MIN
53 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
54 #endif
55 
56 static const struct got_error *
57 verify_fanout_table(uint32_t *fanout_table)
58 {
59 	int i;
60 
61 	for (i = 0; i < 0xff - 1; i++) {
62 		if (be32toh(fanout_table[i]) > be32toh(fanout_table[i + 1]))
63 			return got_error(GOT_ERR_BAD_PACKIDX);
64 	}
65 
66 	return NULL;
67 }
68 
69 const struct got_error *
70 got_packidx_init_hdr(struct got_packidx *p, int verify, off_t packfile_size)
71 {
72 	const struct got_error *err = NULL;
73 	struct got_packidx_v2_hdr *h;
74 	SHA1_CTX ctx;
75 	uint8_t sha1[SHA1_DIGEST_LENGTH];
76 	size_t nobj, len_fanout, len_ids, offset, remain;
77 	ssize_t n;
78 	int i;
79 
80 	SHA1Init(&ctx);
81 
82 	h = &p->hdr;
83 	offset = 0;
84 	remain = p->len;
85 
86 	if (remain < sizeof(*h->magic)) {
87 		err = got_error(GOT_ERR_BAD_PACKIDX);
88 		goto done;
89 	}
90 	if (p->map)
91 		h->magic = (uint32_t *)(p->map + offset);
92 	else {
93 		h->magic = malloc(sizeof(*h->magic));
94 		if (h->magic == NULL) {
95 			err = got_error_from_errno("malloc");
96 			goto done;
97 		}
98 		n = read(p->fd, h->magic, sizeof(*h->magic));
99 		if (n < 0) {
100 			err = got_error_from_errno("read");
101 			goto done;
102 		} else if (n != sizeof(*h->magic)) {
103 			err = got_error(GOT_ERR_BAD_PACKIDX);
104 			goto done;
105 		}
106 	}
107 	if (*h->magic != htobe32(GOT_PACKIDX_V2_MAGIC)) {
108 		err = got_error(GOT_ERR_BAD_PACKIDX);
109 		goto done;
110 	}
111 	offset += sizeof(*h->magic);
112 	remain -= sizeof(*h->magic);
113 
114 	if (verify)
115 		SHA1Update(&ctx, (uint8_t *)h->magic, sizeof(*h->magic));
116 
117 	if (remain < sizeof(*h->version)) {
118 		err = got_error(GOT_ERR_BAD_PACKIDX);
119 		goto done;
120 	}
121 	if (p->map)
122 		h->version = (uint32_t *)(p->map + offset);
123 	else {
124 		h->version = malloc(sizeof(*h->version));
125 		if (h->version == NULL) {
126 			err = got_error_from_errno("malloc");
127 			goto done;
128 		}
129 		n = read(p->fd, h->version, sizeof(*h->version));
130 		if (n < 0) {
131 			err = got_error_from_errno("read");
132 			goto done;
133 		} else if (n != sizeof(*h->version)) {
134 			err = got_error(GOT_ERR_BAD_PACKIDX);
135 			goto done;
136 		}
137 	}
138 	if (*h->version != htobe32(GOT_PACKIDX_VERSION)) {
139 		err = got_error(GOT_ERR_BAD_PACKIDX);
140 		goto done;
141 	}
142 	offset += sizeof(*h->version);
143 	remain -= sizeof(*h->version);
144 
145 	if (verify)
146 		SHA1Update(&ctx, (uint8_t *)h->version, sizeof(*h->version));
147 
148 	len_fanout =
149 	    sizeof(*h->fanout_table) * GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS;
150 	if (remain < len_fanout) {
151 		err = got_error(GOT_ERR_BAD_PACKIDX);
152 		goto done;
153 	}
154 	if (p->map)
155 		h->fanout_table = (uint32_t *)(p->map + offset);
156 	else {
157 		h->fanout_table = malloc(len_fanout);
158 		if (h->fanout_table == NULL) {
159 			err = got_error_from_errno("malloc");
160 			goto done;
161 		}
162 		n = read(p->fd, h->fanout_table, len_fanout);
163 		if (n < 0) {
164 			err = got_error_from_errno("read");
165 			goto done;
166 		} else if (n != len_fanout) {
167 			err = got_error(GOT_ERR_BAD_PACKIDX);
168 			goto done;
169 		}
170 	}
171 	err = verify_fanout_table(h->fanout_table);
172 	if (err)
173 		goto done;
174 	if (verify)
175 		SHA1Update(&ctx, (uint8_t *)h->fanout_table, len_fanout);
176 	offset += len_fanout;
177 	remain -= len_fanout;
178 
179 	nobj = be32toh(h->fanout_table[0xff]);
180 	len_ids = nobj * sizeof(*h->sorted_ids);
181 	if (len_ids <= nobj || len_ids > remain) {
182 		err = got_error(GOT_ERR_BAD_PACKIDX);
183 		goto done;
184 	}
185 	if (p->map)
186 		h->sorted_ids =
187 		    (struct got_packidx_object_id *)((uint8_t*)(p->map + offset));
188 	else {
189 		h->sorted_ids = malloc(len_ids);
190 		if (h->sorted_ids == NULL) {
191 			err = got_error(GOT_ERR_BAD_PACKIDX);
192 			goto done;
193 		}
194 		n = read(p->fd, h->sorted_ids, len_ids);
195 		if (n < 0)
196 			err = got_error_from_errno("read");
197 		else if (n != len_ids) {
198 			err = got_error(GOT_ERR_BAD_PACKIDX);
199 			goto done;
200 		}
201 	}
202 	if (verify)
203 		SHA1Update(&ctx, (uint8_t *)h->sorted_ids, len_ids);
204 	offset += len_ids;
205 	remain -= len_ids;
206 
207 	if (remain < nobj * sizeof(*h->crc32)) {
208 		err = got_error(GOT_ERR_BAD_PACKIDX);
209 		goto done;
210 	}
211 	if (p->map)
212 		h->crc32 = (uint32_t *)((uint8_t*)(p->map + offset));
213 	else {
214 		h->crc32 = malloc(nobj * sizeof(*h->crc32));
215 		if (h->crc32 == NULL) {
216 			err = got_error_from_errno("malloc");
217 			goto done;
218 		}
219 		n = read(p->fd, h->crc32, nobj * sizeof(*h->crc32));
220 		if (n < 0)
221 			err = got_error_from_errno("read");
222 		else if (n != nobj * sizeof(*h->crc32)) {
223 			err = got_error(GOT_ERR_BAD_PACKIDX);
224 			goto done;
225 		}
226 	}
227 	if (verify)
228 		SHA1Update(&ctx, (uint8_t *)h->crc32, nobj * sizeof(*h->crc32));
229 	remain -= nobj * sizeof(*h->crc32);
230 	offset += nobj * sizeof(*h->crc32);
231 
232 	if (remain < nobj * sizeof(*h->offsets)) {
233 		err = got_error(GOT_ERR_BAD_PACKIDX);
234 		goto done;
235 	}
236 	if (p->map)
237 		h->offsets = (uint32_t *)((uint8_t*)(p->map + offset));
238 	else {
239 		h->offsets = malloc(nobj * sizeof(*h->offsets));
240 		if (h->offsets == NULL) {
241 			err = got_error_from_errno("malloc");
242 			goto done;
243 		}
244 		n = read(p->fd, h->offsets, nobj * sizeof(*h->offsets));
245 		if (n < 0)
246 			err = got_error_from_errno("read");
247 		else if (n != nobj * sizeof(*h->offsets)) {
248 			err = got_error(GOT_ERR_BAD_PACKIDX);
249 			goto done;
250 		}
251 	}
252 	if (verify)
253 		SHA1Update(&ctx, (uint8_t *)h->offsets,
254 		    nobj * sizeof(*h->offsets));
255 	remain -= nobj * sizeof(*h->offsets);
256 	offset += nobj * sizeof(*h->offsets);
257 
258 	/* Large file offsets are contained only in files > 2GB. */
259 	if (verify || packfile_size > 0x7fffffff) {
260 		for (i = 0; i < nobj; i++) {
261 			uint32_t o = h->offsets[i];
262 			if (o & htobe32(GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX))
263 				p->nlargeobj++;
264 		}
265 	}
266 	if (p->nlargeobj == 0)
267 		goto checksum;
268 	else if (packfile_size <= 0x7fffffff) {
269 		err = got_error(GOT_ERR_BAD_PACKIDX);
270 		goto done;
271 	}
272 
273 	if (remain < p->nlargeobj * sizeof(*h->large_offsets)) {
274 		err = got_error(GOT_ERR_BAD_PACKIDX);
275 		goto done;
276 	}
277 	if (p->map)
278 		h->large_offsets = (uint64_t *)((uint8_t*)(p->map + offset));
279 	else {
280 		h->large_offsets = malloc(p->nlargeobj *
281 		    sizeof(*h->large_offsets));
282 		if (h->large_offsets == NULL) {
283 			err = got_error_from_errno("malloc");
284 			goto done;
285 		}
286 		n = read(p->fd, h->large_offsets,
287 		    p->nlargeobj * sizeof(*h->large_offsets));
288 		if (n < 0)
289 			err = got_error_from_errno("read");
290 		else if (n != p->nlargeobj * sizeof(*h->large_offsets)) {
291 			err = got_error(GOT_ERR_BAD_PACKIDX);
292 			goto done;
293 		}
294 	}
295 	if (verify)
296 		SHA1Update(&ctx, (uint8_t*)h->large_offsets,
297 		    p->nlargeobj * sizeof(*h->large_offsets));
298 	remain -= p->nlargeobj * sizeof(*h->large_offsets);
299 	offset += p->nlargeobj * sizeof(*h->large_offsets);
300 
301 checksum:
302 	if (remain < sizeof(*h->trailer)) {
303 		err = got_error(GOT_ERR_BAD_PACKIDX);
304 		goto done;
305 	}
306 	if (p->map)
307 		h->trailer =
308 		    (struct got_packidx_trailer *)((uint8_t*)(p->map + offset));
309 	else {
310 		h->trailer = malloc(sizeof(*h->trailer));
311 		if (h->trailer == NULL) {
312 			err = got_error_from_errno("malloc");
313 			goto done;
314 		}
315 		n = read(p->fd, h->trailer, sizeof(*h->trailer));
316 		if (n < 0)
317 			err = got_error_from_errno("read");
318 		else if (n != sizeof(*h->trailer)) {
319 			err = got_error(GOT_ERR_BAD_PACKIDX);
320 			goto done;
321 		}
322 	}
323 	if (verify) {
324 		SHA1Update(&ctx, h->trailer->packfile_sha1, SHA1_DIGEST_LENGTH);
325 		SHA1Final(sha1, &ctx);
326 		if (memcmp(h->trailer->packidx_sha1, sha1,
327 		    SHA1_DIGEST_LENGTH) != 0)
328 			err = got_error(GOT_ERR_PACKIDX_CSUM);
329 	}
330 done:
331 	return err;
332 }
333 
334 const struct got_error *
335 got_packidx_open(struct got_packidx **packidx,
336     int dir_fd, const char *relpath, int verify)
337 {
338 	const struct got_error *err = NULL;
339 	struct got_packidx *p = NULL;
340 	char *pack_relpath;
341 	struct stat idx_sb, pack_sb;
342 
343 	*packidx = NULL;
344 
345 	err = got_packidx_get_packfile_path(&pack_relpath, relpath);
346 	if (err)
347 		return err;
348 
349 	/*
350 	 * Ensure that a corresponding pack file exists.
351 	 * Some Git repositories have this problem. Git seems to ignore
352 	 * the existence of lonely pack index files but we do not.
353 	 */
354 	if (fstatat(dir_fd, pack_relpath, &pack_sb, 0) == -1) {
355 		if (errno == ENOENT) {
356 			err = got_error_fmt(GOT_ERR_LONELY_PACKIDX,
357 			    "%s", relpath);
358 		} else
359 			err = got_error_from_errno2("fstatat", pack_relpath);
360 		goto done;
361 	}
362 
363 	p = calloc(1, sizeof(*p));
364 	if (p == NULL) {
365 		err = got_error_from_errno("calloc");
366 		goto done;
367 	}
368 
369 	p->fd = openat(dir_fd, relpath, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
370 	if (p->fd == -1) {
371 		err = got_error_from_errno2("openat", relpath);
372 		goto done;
373 	}
374 
375 	if (fstat(p->fd, &idx_sb) != 0) {
376 		err = got_error_from_errno2("fstat", relpath);
377 		goto done;
378 	}
379 	p->len = idx_sb.st_size;
380 	if (p->len < sizeof(p->hdr)) {
381 		err = got_error(GOT_ERR_BAD_PACKIDX);
382 		goto done;
383 	}
384 
385 	p->path_packidx = strdup(relpath);
386 	if (p->path_packidx == NULL) {
387 		err = got_error_from_errno("strdup");
388 		goto done;
389 	}
390 
391 #ifndef GOT_PACK_NO_MMAP
392 	if (p->len > 0 && p->len <= SIZE_MAX) {
393 		p->map = mmap(NULL, p->len, PROT_READ, MAP_PRIVATE, p->fd, 0);
394 		if (p->map == MAP_FAILED) {
395 			if (errno != ENOMEM) {
396 				err = got_error_from_errno("mmap");
397 				goto done;
398 			}
399 			p->map = NULL; /* fall back to read(2) */
400 		}
401 	}
402 #endif
403 
404 	err = got_packidx_init_hdr(p, verify, pack_sb.st_size);
405 done:
406 	if (err) {
407 		if (p)
408 			got_packidx_close(p);
409 	} else
410 		*packidx = p;
411 	free(pack_relpath);
412 	return err;
413 }
414 
415 const struct got_error *
416 got_packidx_close(struct got_packidx *packidx)
417 {
418 	const struct got_error *err = NULL;
419 
420 	free(packidx->path_packidx);
421 	if (packidx->map) {
422 		if (munmap(packidx->map, packidx->len) == -1)
423 			err = got_error_from_errno("munmap");
424 	} else {
425 		free(packidx->hdr.magic);
426 		free(packidx->hdr.version);
427 		free(packidx->hdr.fanout_table);
428 		free(packidx->hdr.sorted_ids);
429 		free(packidx->hdr.crc32);
430 		free(packidx->hdr.offsets);
431 		free(packidx->hdr.large_offsets);
432 		free(packidx->hdr.trailer);
433 	}
434 	if (close(packidx->fd) == -1 && err == NULL)
435 		err = got_error_from_errno("close");
436 	free(packidx->sorted_offsets);
437 	free(packidx->sorted_large_offsets);
438 	free(packidx);
439 
440 	return err;
441 }
442 
443 const struct got_error *
444 got_packidx_get_packfile_path(char **path_packfile, const char *path_packidx)
445 {
446 	size_t size;
447 
448 	/* Packfile path contains ".pack" instead of ".idx", so add one byte. */
449 	size = strlen(path_packidx) + 2;
450 	if (size < GOT_PACKFILE_NAMELEN + 1)
451 		return got_error_path(path_packidx, GOT_ERR_BAD_PATH);
452 
453 	*path_packfile = malloc(size);
454 	if (*path_packfile == NULL)
455 		return got_error_from_errno("malloc");
456 
457 	/* Copy up to and excluding ".idx". */
458 	if (strlcpy(*path_packfile, path_packidx,
459 	    size - strlen(GOT_PACKIDX_SUFFIX) - 1) >= size)
460 		return got_error(GOT_ERR_NO_SPACE);
461 
462 	if (strlcat(*path_packfile, GOT_PACKFILE_SUFFIX, size) >= size)
463 		return got_error(GOT_ERR_NO_SPACE);
464 
465 	return NULL;
466 }
467 
468 off_t
469 got_packidx_get_object_offset(struct got_packidx *packidx, int idx)
470 {
471 	uint32_t offset = be32toh(packidx->hdr.offsets[idx]);
472 	if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
473 		uint64_t loffset;
474 		idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
475 		if (idx < 0 || idx >= packidx->nlargeobj ||
476 		    packidx->hdr.large_offsets == NULL)
477 			return -1;
478 		loffset = be64toh(packidx->hdr.large_offsets[idx]);
479 		return (loffset > INT64_MAX ? -1 : (off_t)loffset);
480 	}
481 	return (off_t)(offset & GOT_PACKIDX_OFFSET_VAL_MASK);
482 }
483 
484 int
485 got_packidx_get_object_idx(struct got_packidx *packidx,
486     struct got_object_id *id)
487 {
488 	u_int8_t id0 = id->sha1[0];
489 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
490 	int left = 0, right = totobj - 1;
491 
492 	if (id0 > 0)
493 		left = be32toh(packidx->hdr.fanout_table[id0 - 1]);
494 
495 	while (left <= right) {
496 		struct got_packidx_object_id *oid;
497 		int i, cmp;
498 
499 		i = ((left + right) / 2);
500 		oid = &packidx->hdr.sorted_ids[i];
501 		cmp = memcmp(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
502 		if (cmp == 0)
503 			return i;
504 		else if (cmp > 0)
505 			left = i + 1;
506 		else if (cmp < 0)
507 			right = i - 1;
508 	}
509 
510 	return -1;
511 }
512 
513 static int
514 offset_cmp(const void *pa, const void *pb)
515 {
516 	const struct got_pack_offset_index *a, *b;
517 
518 	a = (const struct got_pack_offset_index *)pa;
519 	b = (const struct got_pack_offset_index *)pb;
520 
521 	if (a->offset < b->offset)
522 		return -1;
523 	else if (a->offset > b->offset)
524 		return 1;
525 
526 	return 0;
527 }
528 
529 static int
530 large_offset_cmp(const void *pa, const void *pb)
531 {
532 	const struct got_pack_large_offset_index *a, *b;
533 
534 	a = (const struct got_pack_large_offset_index *)pa;
535 	b = (const struct got_pack_large_offset_index *)pb;
536 
537 	if (a->offset < b->offset)
538 		return -1;
539 	else if (a->offset > b->offset)
540 		return 1;
541 
542 	return 0;
543 }
544 
545 static const struct got_error *
546 build_offset_index(struct got_packidx *p)
547 {
548 	uint32_t nobj = be32toh(p->hdr.fanout_table[0xff]);
549 	unsigned int i, j, k;
550 
551 	p->sorted_offsets = calloc(nobj - p->nlargeobj,
552 	    sizeof(p->sorted_offsets[0]));
553 	if (p->sorted_offsets == NULL)
554 		return got_error_from_errno("calloc");
555 
556 	if (p->nlargeobj > 0) {
557 		p->sorted_large_offsets = calloc(p->nlargeobj,
558 		    sizeof(p->sorted_large_offsets[0]));
559 		if (p->sorted_large_offsets == NULL)
560 			return got_error_from_errno("calloc");
561 	}
562 
563 	j = 0;
564 	k = 0;
565 	for (i = 0; i < nobj; i++) {
566 		uint32_t offset = be32toh(p->hdr.offsets[i]);
567 		if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
568 			uint64_t loffset;
569 			uint32_t idx;
570 			idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
571 			if (idx >= p->nlargeobj ||
572 			    p->nlargeobj == 0 ||
573 			    p->hdr.large_offsets == NULL)
574 				return got_error(GOT_ERR_BAD_PACKIDX);
575 			loffset = be64toh(p->hdr.large_offsets[idx]);
576 			p->sorted_large_offsets[j].offset = loffset;
577 			p->sorted_large_offsets[j].idx = i;
578 			j++;
579 		} else {
580 			p->sorted_offsets[k].offset = offset;
581 			p->sorted_offsets[k].idx = i;
582 			k++;
583 		}
584 	}
585 	if (j != p->nlargeobj || k != nobj - p->nlargeobj)
586 		return got_error(GOT_ERR_BAD_PACKIDX);
587 
588 	qsort(p->sorted_offsets, nobj - p->nlargeobj,
589 	    sizeof(p->sorted_offsets[0]), offset_cmp);
590 
591 	if (p->sorted_large_offsets)
592 		qsort(p->sorted_large_offsets, p->nlargeobj,
593 		    sizeof(p->sorted_large_offsets[0]), large_offset_cmp);
594 
595 	return NULL;
596 }
597 
598 const struct got_error *
599 got_packidx_get_offset_idx(int *idx, struct got_packidx *packidx, off_t offset)
600 {
601 	const struct got_error *err;
602 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
603 	int i, left, right;
604 
605 	*idx = -1;
606 
607 	if (packidx->sorted_offsets == NULL) {
608 		err = build_offset_index(packidx);
609 		if (err)
610 			return err;
611 	}
612 
613 	if (offset >= 0x7fffffff) {
614 		uint64_t lo;
615 		left = 0, right = packidx->nlargeobj - 1;
616 		while (left <= right) {
617 			i = ((left + right) / 2);
618 			lo = packidx->sorted_large_offsets[i].offset;
619 			if (lo == offset) {
620 				*idx = packidx->sorted_large_offsets[i].idx;
621 				break;
622 			} else if (offset > lo)
623 				left = i + 1;
624 			else if (offset < lo)
625 				right = i - 1;
626 		}
627 	} else {
628 		uint32_t o;
629 		left = 0, right = totobj - packidx->nlargeobj - 1;
630 		while (left <= right) {
631 			i = ((left + right) / 2);
632 			o = packidx->sorted_offsets[i].offset;
633 			if (o == offset) {
634 				*idx = packidx->sorted_offsets[i].idx;
635 				break;
636 			} else if (offset > o)
637 				left = i + 1;
638 			else if (offset < o)
639 				right = i - 1;
640 		}
641 	}
642 
643 	return NULL;
644 }
645 
646 const struct got_error *
647 got_packidx_get_object_id(struct got_object_id *id,
648     struct got_packidx *packidx, int idx)
649 {
650 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
651 	struct got_packidx_object_id *oid;
652 
653 	if (idx < 0 || idx >= totobj)
654 		return got_error(GOT_ERR_NO_OBJ);
655 
656 	oid = &packidx->hdr.sorted_ids[idx];
657 	memcpy(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
658 	return NULL;
659 }
660 
661 const struct got_error *
662 got_packidx_match_id_str_prefix(struct got_object_id_queue *matched_ids,
663     struct got_packidx *packidx, const char *id_str_prefix)
664 {
665 	const struct got_error *err = NULL;
666 	u_int8_t id0;
667 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
668 	char hex[3];
669 	size_t prefix_len = strlen(id_str_prefix);
670 	struct got_packidx_object_id *oid;
671 	uint32_t i = 0;
672 
673 	STAILQ_INIT(matched_ids);
674 
675 	if (prefix_len < 2)
676 		return got_error_path(id_str_prefix, GOT_ERR_BAD_OBJ_ID_STR);
677 
678 	hex[0] = id_str_prefix[0];
679 	hex[1] = id_str_prefix[1];
680 	hex[2] = '\0';
681 	if (!got_parse_xdigit(&id0, hex))
682 		return got_error_path(id_str_prefix, GOT_ERR_BAD_OBJ_ID_STR);
683 
684 	if (id0 > 0)
685 		i = be32toh(packidx->hdr.fanout_table[id0 - 1]);
686 	oid = &packidx->hdr.sorted_ids[i];
687 	while (i < totobj && oid->sha1[0] == id0) {
688 		char id_str[SHA1_DIGEST_STRING_LENGTH];
689 		struct got_object_qid *qid;
690 		int cmp;
691 
692 		if (!got_sha1_digest_to_str(oid->sha1, id_str, sizeof(id_str)))
693 		        return got_error(GOT_ERR_NO_SPACE);
694 
695 		cmp = strncmp(id_str, id_str_prefix, prefix_len);
696 		if (cmp < 0) {
697 			oid = &packidx->hdr.sorted_ids[++i];
698 			continue;
699 		} else if (cmp > 0)
700 			break;
701 
702 		err = got_object_qid_alloc_partial(&qid);
703 		if (err)
704 			break;
705 		memcpy(qid->id.sha1, oid->sha1, SHA1_DIGEST_LENGTH);
706 		STAILQ_INSERT_TAIL(matched_ids, qid, entry);
707 
708 		oid = &packidx->hdr.sorted_ids[++i];
709 	}
710 
711 	if (err)
712 		got_object_id_queue_free(matched_ids);
713 	return err;
714 }
715 
716 static void
717 set_max_datasize(void)
718 {
719 	struct rlimit rl;
720 
721 	if (getrlimit(RLIMIT_DATA, &rl) != 0)
722 		return;
723 
724 	rl.rlim_cur = rl.rlim_max;
725 	setrlimit(RLIMIT_DATA, &rl);
726 }
727 
728 const struct got_error *
729 got_pack_start_privsep_child(struct got_pack *pack, struct got_packidx *packidx)
730 {
731 	const struct got_error *err = NULL;
732 	int imsg_fds[2];
733 	pid_t pid;
734 	struct imsgbuf *ibuf;
735 
736 	ibuf = calloc(1, sizeof(*ibuf));
737 	if (ibuf == NULL)
738 		return got_error_from_errno("calloc");
739 
740 	pack->privsep_child = calloc(1, sizeof(*pack->privsep_child));
741 	if (pack->privsep_child == NULL) {
742 		err = got_error_from_errno("calloc");
743 		free(ibuf);
744 		return err;
745 	}
746 	pack->child_has_tempfiles = 0;
747 	pack->child_has_delta_outfd = 0;
748 
749 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
750 		err = got_error_from_errno("socketpair");
751 		goto done;
752 	}
753 
754 	pid = fork();
755 	if (pid == -1) {
756 		err = got_error_from_errno("fork");
757 		goto done;
758 	} else if (pid == 0) {
759 		set_max_datasize();
760 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PACK,
761 		    pack->path_packfile);
762 		/* not reached */
763 	}
764 
765 	if (close(imsg_fds[1]) == -1)
766 		return got_error_from_errno("close");
767 	pack->privsep_child->imsg_fd = imsg_fds[0];
768 	pack->privsep_child->pid = pid;
769 	imsg_init(ibuf, imsg_fds[0]);
770 	pack->privsep_child->ibuf = ibuf;
771 
772 	err = got_privsep_init_pack_child(ibuf, pack, packidx);
773 	if (err) {
774 		const struct got_error *child_err;
775 		err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
776 		child_err = got_privsep_wait_for_child(
777 		    pack->privsep_child->pid);
778 		if (child_err && err == NULL)
779 			err = child_err;
780 	}
781 done:
782 	if (err) {
783 		free(ibuf);
784 		free(pack->privsep_child);
785 		pack->privsep_child = NULL;
786 	}
787 	return err;
788 }
789 
790 static const struct got_error *
791 pack_stop_privsep_child(struct got_pack *pack)
792 {
793 	const struct got_error *err = NULL, *close_err = NULL;
794 
795 	if (pack->privsep_child == NULL)
796 		return NULL;
797 
798 	err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
799 	if (err)
800 		return err;
801 	if (close(pack->privsep_child->imsg_fd) == -1)
802 		close_err = got_error_from_errno("close");
803 	err = got_privsep_wait_for_child(pack->privsep_child->pid);
804 	if (close_err && err == NULL)
805 		err = close_err;
806 	imsg_clear(pack->privsep_child->ibuf);
807 	free(pack->privsep_child->ibuf);
808 	free(pack->privsep_child);
809 	pack->privsep_child = NULL;
810 	return err;
811 }
812 
813 const struct got_error *
814 got_pack_close(struct got_pack *pack)
815 {
816 	const struct got_error *err = NULL;
817 
818 	err = pack_stop_privsep_child(pack);
819 	if (pack->map && munmap(pack->map, pack->filesize) == -1 && !err)
820 		err = got_error_from_errno("munmap");
821 	if (pack->fd != -1 && close(pack->fd) == -1 && err == NULL)
822 		err = got_error_from_errno("close");
823 	pack->fd = -1;
824 	free(pack->path_packfile);
825 	pack->path_packfile = NULL;
826 	pack->filesize = 0;
827 	if (pack->delta_cache) {
828 		got_delta_cache_free(pack->delta_cache);
829 		pack->delta_cache = NULL;
830 	}
831 
832 	/*
833 	 * Leave accumfd and basefd alone. They are managed by the
834 	 * repository layer and can be reused.
835 	 */
836 
837 	return err;
838 }
839 
840 const struct got_error *
841 got_pack_parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len,
842     struct got_pack *pack, off_t offset)
843 {
844 	uint8_t t = 0;
845 	uint64_t s = 0;
846 	uint8_t sizeN;
847 	size_t mapoff = 0;
848 	int i = 0;
849 
850 	*len = 0;
851 
852 	if (offset >= pack->filesize)
853 		return got_error(GOT_ERR_PACK_OFFSET);
854 
855 	if (pack->map) {
856 		if (offset > SIZE_MAX) {
857 			return got_error_fmt(GOT_ERR_PACK_OFFSET,
858 			    "offset %lld overflows size_t",
859 			    (long long)offset);
860 		}
861 
862 		mapoff = (size_t)offset;
863 	} else {
864 		if (lseek(pack->fd, offset, SEEK_SET) == -1)
865 			return got_error_from_errno("lseek");
866 	}
867 
868 	do {
869 		/* We do not support size values which don't fit in 64 bit. */
870 		if (i > 9)
871 			return got_error_fmt(GOT_ERR_OBJ_TOO_LARGE,
872 			    "packfile offset %lld", (long long)offset);
873 
874 		if (pack->map) {
875 			if (mapoff + sizeof(sizeN) >= pack->filesize)
876 				return got_error(GOT_ERR_BAD_PACKFILE);
877 			sizeN = *(pack->map + mapoff);
878 			mapoff += sizeof(sizeN);
879 		} else {
880 			ssize_t n = read(pack->fd, &sizeN, sizeof(sizeN));
881 			if (n < 0)
882 				return got_error_from_errno("read");
883 			if (n != sizeof(sizeN))
884 				return got_error(GOT_ERR_BAD_PACKFILE);
885 		}
886 		*len += sizeof(sizeN);
887 
888 		if (i == 0) {
889 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
890 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
891 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
892 		} else {
893 			size_t shift = 4 + 7 * (i - 1);
894 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
895 		}
896 		i++;
897 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
898 
899 	*type = t;
900 	*size = s;
901 	return NULL;
902 }
903 
904 static const struct got_error *
905 open_plain_object(struct got_object **obj, struct got_object_id *id,
906     uint8_t type, off_t offset, size_t size, int idx)
907 {
908 	*obj = calloc(1, sizeof(**obj));
909 	if (*obj == NULL)
910 		return got_error_from_errno("calloc");
911 
912 	(*obj)->type = type;
913 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
914 	(*obj)->pack_idx = idx;
915 	(*obj)->hdrlen = 0;
916 	(*obj)->size = size;
917 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
918 	(*obj)->pack_offset = offset;
919 
920 	return NULL;
921 }
922 
923 static const struct got_error *
924 parse_negative_offset(int64_t *offset, size_t *len, struct got_pack *pack,
925     off_t delta_offset)
926 {
927 	int64_t o = 0;
928 	uint8_t offN;
929 	int i = 0;
930 
931 	*offset = 0;
932 	*len = 0;
933 
934 	do {
935 		/* We do not support offset values which don't fit in 64 bit. */
936 		if (i > 8)
937 			return got_error(GOT_ERR_NO_SPACE);
938 
939 		if (pack->map) {
940 			size_t mapoff;
941 
942 			if (delta_offset + *len > SIZE_MAX) {
943 				return got_error_fmt(GOT_ERR_PACK_OFFSET,
944 				    "mapoff %lld would overflow size_t",
945 				    (long long)delta_offset + *len);
946 			}
947 
948 			mapoff = (size_t)delta_offset + *len;
949 			if (mapoff + sizeof(offN) >= pack->filesize)
950 				return got_error(GOT_ERR_PACK_OFFSET);
951 			offN = *(pack->map + mapoff);
952 		} else {
953 			ssize_t n;
954 			n = read(pack->fd, &offN, sizeof(offN));
955 			if (n < 0)
956 				return got_error_from_errno("read");
957 			if (n != sizeof(offN))
958 				return got_error(GOT_ERR_BAD_PACKFILE);
959 		}
960 		*len += sizeof(offN);
961 
962 		if (i == 0)
963 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
964 		else {
965 			o++;
966 			o <<= 7;
967 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
968 		}
969 		i++;
970 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
971 
972 	*offset = o;
973 	return NULL;
974 }
975 
976 const struct got_error *
977 got_pack_parse_offset_delta(off_t *base_offset, size_t *len,
978     struct got_pack *pack, off_t offset, size_t tslen)
979 {
980 	const struct got_error *err;
981 	int64_t negoffset;
982 	size_t negofflen;
983 
984 	*len = 0;
985 
986 	err = parse_negative_offset(&negoffset, &negofflen, pack,
987 	    offset + tslen);
988 	if (err)
989 		return err;
990 
991 	/* Compute the base object's offset (must be in the same pack file). */
992 	*base_offset = (offset - negoffset);
993 	if (*base_offset <= 0)
994 		return got_error(GOT_ERR_BAD_PACKFILE);
995 
996 	*len = negofflen;
997 	return NULL;
998 }
999 
1000 static const struct got_error *
1001 read_delta_data(uint8_t **delta_buf, size_t *delta_len,
1002     size_t *delta_compressed_len, size_t delta_data_offset,
1003     struct got_pack *pack)
1004 {
1005 	const struct got_error *err = NULL;
1006 	size_t consumed = 0;
1007 
1008 	if (pack->map) {
1009 		if (delta_data_offset >= pack->filesize)
1010 			return got_error(GOT_ERR_PACK_OFFSET);
1011 		err = got_inflate_to_mem_mmap(delta_buf, delta_len,
1012 		    &consumed, NULL, pack->map, delta_data_offset,
1013 		    pack->filesize - delta_data_offset);
1014 		if (err)
1015 			return err;
1016 	} else {
1017 		if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1)
1018 			return got_error_from_errno("lseek");
1019 		err = got_inflate_to_mem_fd(delta_buf, delta_len,
1020 		    &consumed, NULL, 0, pack->fd);
1021 		if (err)
1022 			return err;
1023 	}
1024 
1025 	if (delta_compressed_len)
1026 		*delta_compressed_len = consumed;
1027 
1028 	return NULL;
1029 }
1030 
1031 static const struct got_error *
1032 add_delta(struct got_delta_chain *deltas, off_t delta_offset, size_t tslen,
1033     int delta_type, size_t delta_size, off_t delta_data_offset)
1034 {
1035 	struct got_delta *delta;
1036 
1037 	delta = got_delta_open(delta_offset, tslen, delta_type, delta_size,
1038 	    delta_data_offset);
1039 	if (delta == NULL)
1040 		return got_error_from_errno("got_delta_open");
1041 	/* delta is freed in got_object_close() */
1042 	deltas->nentries++;
1043 	STAILQ_INSERT_HEAD(&deltas->entries, delta, entry);
1044 	return NULL;
1045 }
1046 
1047 static const struct got_error *
1048 resolve_offset_delta(struct got_delta_chain *deltas,
1049     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
1050     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
1051 {
1052 	const struct got_error *err;
1053 	off_t base_offset;
1054 	uint8_t base_type;
1055 	uint64_t base_size;
1056 	size_t base_tslen;
1057 	off_t delta_data_offset;
1058 	size_t consumed;
1059 
1060 	err = got_pack_parse_offset_delta(&base_offset, &consumed, pack,
1061 	    delta_offset, tslen);
1062 	if (err)
1063 		return err;
1064 
1065 	delta_data_offset = delta_offset + tslen + consumed;
1066 	if (delta_data_offset >= pack->filesize)
1067 		return got_error(GOT_ERR_PACK_OFFSET);
1068 
1069 	if (pack->map == NULL) {
1070 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
1071 		if (delta_data_offset == -1)
1072 			return got_error_from_errno("lseek");
1073 	}
1074 
1075 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
1076 	    delta_data_offset);
1077 	if (err)
1078 		return err;
1079 
1080 	/* An offset delta must be in the same packfile. */
1081 	if (base_offset >= pack->filesize)
1082 		return got_error(GOT_ERR_PACK_OFFSET);
1083 
1084 	err = got_pack_parse_object_type_and_size(&base_type, &base_size,
1085 	    &base_tslen, pack, base_offset);
1086 	if (err)
1087 		return err;
1088 
1089 	return got_pack_resolve_delta_chain(deltas, packidx, pack, base_offset,
1090 	    base_tslen, base_type, base_size, recursion - 1);
1091 }
1092 
1093 const struct got_error *
1094 got_pack_parse_ref_delta(struct got_object_id *id,
1095     struct got_pack *pack, off_t delta_offset, int tslen)
1096 {
1097 	if (pack->map) {
1098 		size_t mapoff;
1099 
1100 		if (delta_offset + tslen > SIZE_MAX) {
1101 			return got_error_fmt(GOT_ERR_PACK_OFFSET,
1102 			    "mapoff %lld would overflow size_t",
1103 			    (long long)delta_offset + tslen);
1104 		}
1105 
1106 		mapoff = delta_offset + tslen;
1107 		if (mapoff + sizeof(*id) >= pack->filesize)
1108 			return got_error(GOT_ERR_PACK_OFFSET);
1109 		memcpy(id, pack->map + mapoff, sizeof(*id));
1110 	} else {
1111 		ssize_t n;
1112 		n = read(pack->fd, id, sizeof(*id));
1113 		if (n < 0)
1114 			return got_error_from_errno("read");
1115 		if (n != sizeof(*id))
1116 			return got_error(GOT_ERR_BAD_PACKFILE);
1117 	}
1118 
1119 	return NULL;
1120 }
1121 
1122 static const struct got_error *
1123 resolve_ref_delta(struct got_delta_chain *deltas, struct got_packidx *packidx,
1124     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
1125     size_t delta_size, unsigned int recursion)
1126 {
1127 	const struct got_error *err;
1128 	struct got_object_id id;
1129 	int idx;
1130 	off_t base_offset;
1131 	uint8_t base_type;
1132 	uint64_t base_size;
1133 	size_t base_tslen;
1134 	off_t delta_data_offset;
1135 
1136 	if (delta_offset + tslen >= pack->filesize)
1137 		return got_error(GOT_ERR_PACK_OFFSET);
1138 
1139 	err = got_pack_parse_ref_delta(&id, pack, delta_offset, tslen);
1140 	if (err)
1141 		return err;
1142 	if (pack->map) {
1143 		delta_data_offset = delta_offset + tslen + SHA1_DIGEST_LENGTH;
1144 	} else {
1145 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
1146 		if (delta_data_offset == -1)
1147 			return got_error_from_errno("lseek");
1148 	}
1149 
1150 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
1151 	    delta_data_offset);
1152 	if (err)
1153 		return err;
1154 
1155 	/* Delta base must be in the same pack file. */
1156 	idx = got_packidx_get_object_idx(packidx, &id);
1157 	if (idx == -1)
1158 		return got_error(GOT_ERR_NO_OBJ);
1159 
1160 	base_offset = got_packidx_get_object_offset(packidx, idx);
1161 	if (base_offset == -1)
1162 		return got_error(GOT_ERR_BAD_PACKIDX);
1163 
1164 	if (base_offset >= pack->filesize)
1165 		return got_error(GOT_ERR_PACK_OFFSET);
1166 
1167 	err = got_pack_parse_object_type_and_size(&base_type, &base_size,
1168 	    &base_tslen, pack, base_offset);
1169 	if (err)
1170 		return err;
1171 
1172 	return got_pack_resolve_delta_chain(deltas, packidx, pack, base_offset,
1173 	    base_tslen, base_type, base_size, recursion - 1);
1174 }
1175 
1176 const struct got_error *
1177 got_pack_resolve_delta_chain(struct got_delta_chain *deltas,
1178     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
1179     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
1180 {
1181 	const struct got_error *err = NULL;
1182 
1183 	if (--recursion == 0)
1184 		return got_error(GOT_ERR_RECURSION);
1185 
1186 	switch (delta_type) {
1187 	case GOT_OBJ_TYPE_COMMIT:
1188 	case GOT_OBJ_TYPE_TREE:
1189 	case GOT_OBJ_TYPE_BLOB:
1190 	case GOT_OBJ_TYPE_TAG:
1191 		/* Plain types are the final delta base. Recursion ends. */
1192 		err = add_delta(deltas, delta_offset, tslen, delta_type,
1193 		    delta_size, 0);
1194 		break;
1195 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1196 		err = resolve_offset_delta(deltas, packidx, pack,
1197 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
1198 		break;
1199 	case GOT_OBJ_TYPE_REF_DELTA:
1200 		err = resolve_ref_delta(deltas, packidx, pack,
1201 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
1202 		break;
1203 	default:
1204 		return got_error(GOT_ERR_OBJ_TYPE);
1205 	}
1206 
1207 	return err;
1208 }
1209 
1210 static const struct got_error *
1211 open_delta_object(struct got_object **obj, struct got_packidx *packidx,
1212     struct got_pack *pack, struct got_object_id *id, off_t offset,
1213     size_t tslen, int delta_type, size_t delta_size, int idx)
1214 {
1215 	const struct got_error *err = NULL;
1216 	int resolved_type;
1217 
1218 	*obj = calloc(1, sizeof(**obj));
1219 	if (*obj == NULL)
1220 		return got_error_from_errno("calloc");
1221 
1222 	(*obj)->flags = 0;
1223 	(*obj)->hdrlen = 0;
1224 	(*obj)->size = 0; /* Not known because deltas aren't applied yet. */
1225 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
1226 	(*obj)->pack_offset = offset + tslen;
1227 
1228 	STAILQ_INIT(&(*obj)->deltas.entries);
1229 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
1230 	(*obj)->flags |= GOT_OBJ_FLAG_PACKED;
1231 	(*obj)->pack_idx = idx;
1232 
1233 	err = got_pack_resolve_delta_chain(&(*obj)->deltas, packidx, pack,
1234 	    offset, tslen, delta_type, delta_size,
1235 	    GOT_DELTA_CHAIN_RECURSION_MAX);
1236 	if (err)
1237 		goto done;
1238 
1239 	err = got_delta_chain_get_base_type(&resolved_type, &(*obj)->deltas);
1240 	if (err)
1241 		goto done;
1242 	(*obj)->type = resolved_type;
1243 done:
1244 	if (err) {
1245 		got_object_close(*obj);
1246 		*obj = NULL;
1247 	}
1248 	return err;
1249 }
1250 
1251 const struct got_error *
1252 got_packfile_open_object(struct got_object **obj, struct got_pack *pack,
1253     struct got_packidx *packidx, int idx, struct got_object_id *id)
1254 {
1255 	const struct got_error *err = NULL;
1256 	off_t offset;
1257 	uint8_t type;
1258 	uint64_t size;
1259 	size_t tslen;
1260 
1261 	*obj = NULL;
1262 
1263 	offset = got_packidx_get_object_offset(packidx, idx);
1264 	if (offset == -1)
1265 		return got_error(GOT_ERR_BAD_PACKIDX);
1266 
1267 	err = got_pack_parse_object_type_and_size(&type, &size, &tslen,
1268 	    pack, offset);
1269 	if (err)
1270 		return err;
1271 
1272 	switch (type) {
1273 	case GOT_OBJ_TYPE_COMMIT:
1274 	case GOT_OBJ_TYPE_TREE:
1275 	case GOT_OBJ_TYPE_BLOB:
1276 	case GOT_OBJ_TYPE_TAG:
1277 		err = open_plain_object(obj, id, type, offset + tslen,
1278 		    size, idx);
1279 		break;
1280 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1281 	case GOT_OBJ_TYPE_REF_DELTA:
1282 		err = open_delta_object(obj, packidx, pack, id, offset,
1283 		    tslen, type, size, idx);
1284 		break;
1285 	default:
1286 		err = got_error(GOT_ERR_OBJ_TYPE);
1287 		break;
1288 	}
1289 
1290 	return err;
1291 }
1292 
1293 const struct got_error *
1294 got_pack_get_delta_chain_max_size(uint64_t *max_size,
1295     struct got_delta_chain *deltas, struct got_pack *pack)
1296 {
1297 	struct got_delta *delta;
1298 	uint64_t base_size = 0, result_size = 0;
1299 
1300 	*max_size = 0;
1301 	STAILQ_FOREACH(delta, &deltas->entries, entry) {
1302 		/* Plain object types are the delta base. */
1303 		if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1304 		    delta->type != GOT_OBJ_TYPE_TREE &&
1305 		    delta->type != GOT_OBJ_TYPE_BLOB &&
1306 		    delta->type != GOT_OBJ_TYPE_TAG) {
1307 			const struct got_error *err;
1308 			uint8_t *delta_buf = NULL;
1309 			size_t delta_len;
1310 			int cached = 1;
1311 
1312 			if (pack->delta_cache) {
1313 				got_delta_cache_get(&delta_buf, &delta_len,
1314 				    pack->delta_cache, delta->data_offset);
1315 			}
1316 			if (delta_buf == NULL) {
1317 				cached = 0;
1318 				err = read_delta_data(&delta_buf, &delta_len,
1319 				    NULL, delta->data_offset, pack);
1320 				if (err)
1321 					return err;
1322 			}
1323 			if (pack->delta_cache && !cached) {
1324 				err = got_delta_cache_add(pack->delta_cache,
1325 				    delta->data_offset, delta_buf, delta_len);
1326 				if (err == NULL)
1327 					cached = 1;
1328 				else if (err->code != GOT_ERR_NO_SPACE) {
1329 					free(delta_buf);
1330 					return err;
1331 				}
1332 			}
1333 			err = got_delta_get_sizes(&base_size, &result_size,
1334 			    delta_buf, delta_len);
1335 			if (!cached)
1336 				free(delta_buf);
1337 			if (err)
1338 				return err;
1339 		} else
1340 			base_size = delta->size;
1341 		if (base_size > *max_size)
1342 			*max_size = base_size;
1343 		if (result_size > *max_size)
1344 			*max_size = result_size;
1345 	}
1346 
1347 	return NULL;
1348 }
1349 
1350 const struct got_error *
1351 got_pack_get_max_delta_object_size(uint64_t *size, struct got_object *obj,
1352     struct got_pack *pack)
1353 {
1354 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0)
1355 		return got_error(GOT_ERR_OBJ_TYPE);
1356 
1357 	return got_pack_get_delta_chain_max_size(size, &obj->deltas, pack);
1358 }
1359 
1360 const struct got_error *
1361 got_pack_dump_delta_chain_to_file(size_t *result_size,
1362     struct got_delta_chain *deltas, struct got_pack *pack, FILE *outfile,
1363     FILE *base_file, FILE *accum_file)
1364 {
1365 	const struct got_error *err = NULL;
1366 	struct got_delta *delta;
1367 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1368 	size_t base_bufsz = 0, accum_bufsz = 0, accum_size = 0, delta_len;
1369 	/* We process small enough files entirely in memory for speed. */
1370 	const size_t max_bufsize = GOT_DELTA_RESULT_SIZE_CACHED_MAX;
1371 	uint64_t max_size = 0;
1372 	int n = 0;
1373 
1374 	*result_size = 0;
1375 
1376 	if (STAILQ_EMPTY(&deltas->entries))
1377 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1378 
1379 	if (fseeko(base_file, 0L, SEEK_SET) == -1)
1380 		return got_error_from_errno("fseeko");
1381 	if (fseeko(accum_file, 0L, SEEK_SET) == -1)
1382 		return got_error_from_errno("fseeko");
1383 
1384 	/* Deltas are ordered in ascending order. */
1385 	STAILQ_FOREACH(delta, &deltas->entries, entry) {
1386 		uint8_t *delta_buf = NULL;
1387 		uint64_t base_size, result_size = 0;
1388 		int cached = 1;
1389 		if (n == 0) {
1390 			size_t mapoff;
1391 			off_t delta_data_offset;
1392 
1393 			/* Plain object types are the delta base. */
1394 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1395 			    delta->type != GOT_OBJ_TYPE_TREE &&
1396 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1397 			    delta->type != GOT_OBJ_TYPE_TAG) {
1398 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1399 				goto done;
1400 			}
1401 
1402 			delta_data_offset = delta->offset + delta->tslen;
1403 			if (delta_data_offset >= pack->filesize) {
1404 				err = got_error(GOT_ERR_PACK_OFFSET);
1405 				goto done;
1406 			}
1407 			if (pack->map == NULL) {
1408 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1409 				    == -1) {
1410 					err = got_error_from_errno("lseek");
1411 					goto done;
1412 				}
1413 			}
1414 			if (delta->size > max_size)
1415 				max_size = delta->size;
1416 			if (max_size > max_bufsize) {
1417 				if (pack->map) {
1418 					if (delta_data_offset > SIZE_MAX) {
1419 						return got_error_fmt(
1420 						    GOT_ERR_RANGE,
1421 						    "delta offset %lld "
1422 						    "overflows size_t",
1423 						    (long long)
1424 						    delta_data_offset);
1425 					}
1426 
1427 					mapoff = delta_data_offset;
1428 					err = got_inflate_to_file_mmap(
1429 					    &base_bufsz, NULL, NULL, pack->map,
1430 					    mapoff, pack->filesize - mapoff,
1431 					    base_file);
1432 				} else
1433 					err = got_inflate_to_file_fd(
1434 					    &base_bufsz, NULL, NULL, pack->fd,
1435 					    base_file);
1436 			} else {
1437 				accum_buf = malloc(max_size);
1438 				if (accum_buf == NULL) {
1439 					err = got_error_from_errno("malloc");
1440 					goto done;
1441 				}
1442 				accum_bufsz = max_size;
1443 				if (pack->map) {
1444 					if (delta_data_offset > SIZE_MAX) {
1445 						return got_error_fmt(
1446 						    GOT_ERR_RANGE,
1447 						    "delta offset %lld "
1448 						    "overflows size_t",
1449 						    (long long)
1450 						    delta_data_offset);
1451 					}
1452 
1453 					mapoff = delta_data_offset;
1454 					err = got_inflate_to_mem_mmap(&base_buf,
1455 					    &base_bufsz, NULL, NULL,
1456 					    pack->map, mapoff,
1457 					    pack->filesize - mapoff);
1458 				} else
1459 					err = got_inflate_to_mem_fd(&base_buf,
1460 					    &base_bufsz, NULL, NULL, max_size,
1461 					    pack->fd);
1462 			}
1463 			if (err)
1464 				goto done;
1465 			n++;
1466 			if (base_buf == NULL)
1467 				rewind(base_file);
1468 			continue;
1469 		}
1470 
1471 		if (pack->delta_cache) {
1472 			got_delta_cache_get(&delta_buf, &delta_len,
1473 			    pack->delta_cache, delta->data_offset);
1474 		}
1475 		if (delta_buf == NULL) {
1476 			cached = 0;
1477 			err = read_delta_data(&delta_buf, &delta_len, NULL,
1478 			    delta->data_offset, pack);
1479 			if (err)
1480 				goto done;
1481 		}
1482 		if (pack->delta_cache && !cached) {
1483 			err = got_delta_cache_add(pack->delta_cache,
1484 			    delta->data_offset, delta_buf, delta_len);
1485 			if (err == NULL)
1486 				cached = 1;
1487 			else if (err->code != GOT_ERR_NO_SPACE) {
1488 				free(delta_buf);
1489 				goto done;
1490 			}
1491 		}
1492 
1493 		err = got_delta_get_sizes(&base_size, &result_size,
1494 		    delta_buf, delta_len);
1495 		if (err) {
1496 			if (!cached)
1497 				free(delta_buf);
1498 			goto done;
1499 		}
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 				if (!cached)
1512 					free(delta_buf);
1513 				goto done;
1514 			}
1515 			free(base_buf);
1516 			base_buf = NULL;
1517 			free(accum_buf);
1518 			accum_buf = NULL;
1519 		}
1520 
1521 		if (base_buf && max_size > base_bufsz) {
1522 			uint8_t *p = realloc(base_buf, max_size);
1523 			if (p == NULL) {
1524 				err = got_error_from_errno("realloc");
1525 				if (!cached)
1526 					free(delta_buf);
1527 				goto done;
1528 			}
1529 			base_buf = p;
1530 			base_bufsz = max_size;
1531 		}
1532 
1533 		if (accum_buf && max_size > accum_bufsz) {
1534 			uint8_t *p = realloc(accum_buf, max_size);
1535 			if (p == NULL) {
1536 				err = got_error_from_errno("realloc");
1537 				if (!cached)
1538 					free(delta_buf);
1539 				goto done;
1540 			}
1541 			accum_buf = p;
1542 			accum_bufsz = max_size;
1543 		}
1544 
1545 		if (base_buf) {
1546 			err = got_delta_apply_in_mem(base_buf, base_bufsz,
1547 			    delta_buf, delta_len, accum_buf,
1548 			    &accum_size, max_size);
1549 			n++;
1550 		} else {
1551 			err = got_delta_apply(base_file, delta_buf,
1552 			    delta_len,
1553 			    /* Final delta application writes to output file. */
1554 			    ++n < deltas->nentries ? accum_file : outfile,
1555 			    &accum_size);
1556 		}
1557 		if (!cached)
1558 			free(delta_buf);
1559 		if (err)
1560 			goto done;
1561 
1562 		if (n < deltas->nentries) {
1563 			/* Accumulated delta becomes the new base. */
1564 			if (base_buf) {
1565 				uint8_t *tmp = accum_buf;
1566 				size_t tmp_size = accum_bufsz;
1567 				accum_buf = base_buf;
1568 				accum_bufsz = base_bufsz;
1569 				base_buf = tmp;
1570 				base_bufsz = tmp_size;
1571 			} else {
1572 				FILE *tmp = accum_file;
1573 				accum_file = base_file;
1574 				base_file = tmp;
1575 				rewind(base_file);
1576 				rewind(accum_file);
1577 			}
1578 		}
1579 	}
1580 
1581 done:
1582 	free(base_buf);
1583 	if (accum_buf) {
1584 		size_t len = fwrite(accum_buf, 1, accum_size, outfile);
1585 		free(accum_buf);
1586 		if (len != accum_size)
1587 			err = got_ferror(outfile, GOT_ERR_IO);
1588 	}
1589 	rewind(outfile);
1590 	if (err == NULL)
1591 		*result_size = accum_size;
1592 	return err;
1593 }
1594 
1595 const struct got_error *
1596 got_pack_dump_delta_chain_to_mem(uint8_t **outbuf, size_t *outlen,
1597     struct got_delta_chain *deltas, struct got_pack *pack)
1598 {
1599 	const struct got_error *err = NULL;
1600 	struct got_delta *delta;
1601 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1602 	size_t base_bufsz = 0, accum_bufsz = 0, accum_size = 0, delta_len;
1603 	uint64_t max_size = 0;
1604 	int n = 0;
1605 
1606 	*outbuf = NULL;
1607 	*outlen = 0;
1608 
1609 	if (STAILQ_EMPTY(&deltas->entries))
1610 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1611 
1612 	/* Deltas are ordered in ascending order. */
1613 	STAILQ_FOREACH(delta, &deltas->entries, entry) {
1614 		uint8_t *delta_buf = NULL;
1615 		uint64_t base_size, result_size = 0;
1616 		int cached = 1;
1617 		if (n == 0) {
1618 			off_t delta_data_offset;
1619 
1620 			/* Plain object types are the delta base. */
1621 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1622 			    delta->type != GOT_OBJ_TYPE_TREE &&
1623 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1624 			    delta->type != GOT_OBJ_TYPE_TAG) {
1625 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1626 				goto done;
1627 			}
1628 
1629 			delta_data_offset = delta->offset + delta->tslen;
1630 			if (delta_data_offset >= pack->filesize) {
1631 				err = got_error(GOT_ERR_PACK_OFFSET);
1632 				goto done;
1633 			}
1634 
1635 			if (delta->size > max_size)
1636 				max_size = delta->size;
1637 
1638 			if (pack->map) {
1639 				size_t mapoff;
1640 
1641 				if (delta_data_offset > SIZE_MAX) {
1642 					return got_error_fmt(GOT_ERR_RANGE,
1643 					    "delta %lld offset would "
1644 					    "overflow size_t",
1645 					    (long long)delta_data_offset);
1646 				}
1647 
1648 				mapoff = delta_data_offset;
1649 				err = got_inflate_to_mem_mmap(&base_buf,
1650 				    &base_bufsz, NULL, NULL, pack->map,
1651 				    mapoff, pack->filesize - mapoff);
1652 			} else {
1653 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1654 				    == -1) {
1655 					err = got_error_from_errno("lseek");
1656 					goto done;
1657 				}
1658 				err = got_inflate_to_mem_fd(&base_buf,
1659 				    &base_bufsz, NULL, NULL, max_size,
1660 				    pack->fd);
1661 			}
1662 			if (err)
1663 				goto done;
1664 			n++;
1665 			continue;
1666 		}
1667 
1668 		if (pack->delta_cache) {
1669 			got_delta_cache_get(&delta_buf, &delta_len,
1670 			    pack->delta_cache, delta->data_offset);
1671 		}
1672 		if (delta_buf == NULL) {
1673 			cached = 0;
1674 			err = read_delta_data(&delta_buf, &delta_len, NULL,
1675 			    delta->data_offset, pack);
1676 			if (err)
1677 				goto done;
1678 		}
1679 		if (pack->delta_cache && !cached) {
1680 			err = got_delta_cache_add(pack->delta_cache,
1681 			    delta->data_offset, delta_buf, delta_len);
1682 			if (err == NULL)
1683 				cached = 1;
1684 			else if (err->code != GOT_ERR_NO_SPACE) {
1685 				free(delta_buf);
1686 				goto done;
1687 			}
1688 		}
1689 
1690 		err = got_delta_get_sizes(&base_size, &result_size,
1691 		    delta_buf, delta_len);
1692 		if (err) {
1693 			if (!cached)
1694 				free(delta_buf);
1695 			goto done;
1696 		}
1697 		if (base_size > max_size)
1698 			max_size = base_size;
1699 		if (result_size > max_size)
1700 			max_size = result_size;
1701 
1702 		if (max_size > base_bufsz) {
1703 			uint8_t *p = realloc(base_buf, max_size);
1704 			if (p == NULL) {
1705 				err = got_error_from_errno("realloc");
1706 				if (!cached)
1707 					free(delta_buf);
1708 				goto done;
1709 			}
1710 			base_buf = p;
1711 			base_bufsz = max_size;
1712 		}
1713 
1714 		if (max_size > accum_bufsz) {
1715 			uint8_t *p = realloc(accum_buf, max_size);
1716 			if (p == NULL) {
1717 				err = got_error_from_errno("realloc");
1718 				if (!cached)
1719 					free(delta_buf);
1720 				goto done;
1721 			}
1722 			accum_buf = p;
1723 			accum_bufsz = max_size;
1724 		}
1725 
1726 		err = got_delta_apply_in_mem(base_buf, base_bufsz,
1727 		    delta_buf, delta_len, accum_buf,
1728 		    &accum_size, max_size);
1729 		if (!cached)
1730 			free(delta_buf);
1731 		n++;
1732 		if (err)
1733 			goto done;
1734 
1735 		if (n < deltas->nentries) {
1736 			/* Accumulated delta becomes the new base. */
1737 			uint8_t *tmp = accum_buf;
1738 			size_t tmp_size = accum_bufsz;
1739 			accum_buf = base_buf;
1740 			accum_bufsz = base_bufsz;
1741 			base_buf = tmp;
1742 			base_bufsz = tmp_size;
1743 		}
1744 	}
1745 
1746 done:
1747 	free(base_buf);
1748 	if (err) {
1749 		free(accum_buf);
1750 		*outbuf = NULL;
1751 		*outlen = 0;
1752 	} else {
1753 		*outbuf = accum_buf;
1754 		*outlen = accum_size;
1755 	}
1756 	return err;
1757 }
1758 
1759 const struct got_error *
1760 got_packfile_extract_object(struct got_pack *pack, struct got_object *obj,
1761     FILE *outfile, FILE *base_file, FILE *accum_file)
1762 {
1763 	const struct got_error *err = NULL;
1764 
1765 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1766 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1767 
1768 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1769 		if (obj->pack_offset >= pack->filesize)
1770 			return got_error(GOT_ERR_PACK_OFFSET);
1771 
1772 		if (pack->map) {
1773 			size_t mapoff;
1774 
1775 			if (obj->pack_offset > SIZE_MAX) {
1776 				return got_error_fmt(GOT_ERR_RANGE,
1777 				    "pack offset %lld would overflow size_t",
1778 				    (long long)obj->pack_offset);
1779 			}
1780 
1781 			mapoff = obj->pack_offset;
1782 			err = got_inflate_to_file_mmap(&obj->size, NULL, NULL,
1783 			    pack->map, mapoff, pack->filesize - mapoff,
1784 			    outfile);
1785 		} else {
1786 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1787 				return got_error_from_errno("lseek");
1788 			err = got_inflate_to_file_fd(&obj->size, NULL, NULL,
1789 			    pack->fd, outfile);
1790 		}
1791 	} else
1792 		err = got_pack_dump_delta_chain_to_file(&obj->size,
1793 		    &obj->deltas, pack, outfile, base_file, accum_file);
1794 
1795 	return err;
1796 }
1797 
1798 const struct got_error *
1799 got_packfile_extract_object_to_mem(uint8_t **buf, size_t *len,
1800     struct got_object *obj, struct got_pack *pack)
1801 {
1802 	const struct got_error *err = NULL;
1803 
1804 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1805 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1806 
1807 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1808 		if (obj->pack_offset >= pack->filesize)
1809 			return got_error(GOT_ERR_PACK_OFFSET);
1810 		if (pack->map) {
1811 			size_t mapoff;
1812 
1813 			if (obj->pack_offset > SIZE_MAX) {
1814 				return got_error_fmt(GOT_ERR_RANGE,
1815 				    "pack offset %lld would overflow size_t",
1816 				    (long long)obj->pack_offset);
1817 			}
1818 
1819 			mapoff = obj->pack_offset;
1820 			err = got_inflate_to_mem_mmap(buf, len, NULL, NULL,
1821 			    pack->map, mapoff, pack->filesize - mapoff);
1822 		} else {
1823 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1824 				return got_error_from_errno("lseek");
1825 			err = got_inflate_to_mem_fd(buf, len, NULL, NULL,
1826 			    obj->size, pack->fd);
1827 		}
1828 	} else
1829 		err = got_pack_dump_delta_chain_to_mem(buf, len, &obj->deltas,
1830 		    pack);
1831 
1832 	return err;
1833 }
1834 
1835 static const struct got_error *
1836 read_raw_delta_data(uint8_t **delta_buf, size_t *delta_len,
1837     size_t *delta_len_compressed, uint64_t *base_size, uint64_t *result_size,
1838     off_t delta_data_offset, struct got_pack *pack, struct got_packidx *packidx)
1839 {
1840 	const struct got_error *err = NULL;
1841 
1842 	/* Validate decompression and obtain the decompressed size. */
1843 	err = read_delta_data(delta_buf, delta_len, delta_len_compressed,
1844 	    delta_data_offset, pack);
1845 	if (err)
1846 		return err;
1847 
1848 	/* Read delta base/result sizes from head of delta stream. */
1849 	err = got_delta_get_sizes(base_size, result_size,
1850 	    *delta_buf, *delta_len);
1851 	if (err)
1852 		goto done;
1853 
1854 	/* Discard decompressed delta and read it again in compressed form. */
1855 	free(*delta_buf);
1856 	*delta_buf = malloc(*delta_len_compressed);
1857 	if (*delta_buf == NULL) {
1858 		err = got_error_from_errno("malloc");
1859 		goto done;
1860 	}
1861 	if (pack->map) {
1862 		if (delta_data_offset >= pack->filesize) {
1863 			err = got_error(GOT_ERR_PACK_OFFSET);
1864 			goto done;
1865 		}
1866 		memcpy(*delta_buf, pack->map + delta_data_offset,
1867 		    *delta_len_compressed);
1868 	} else {
1869 		ssize_t n;
1870 		if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1) {
1871 			err = got_error_from_errno("lseek");
1872 			goto done;
1873 		}
1874 		n = read(pack->fd, *delta_buf, *delta_len_compressed);
1875 		if (n < 0) {
1876 			err = got_error_from_errno("read");
1877 			goto done;
1878 		} else if (n != *delta_len_compressed) {
1879 			err = got_error(GOT_ERR_IO);
1880 			goto done;
1881 		}
1882 	}
1883 done:
1884 	if (err) {
1885 		free(*delta_buf);
1886 		*delta_buf = NULL;
1887 		*delta_len = 0;
1888 		*delta_len_compressed = 0;
1889 		*base_size = 0;
1890 		*result_size = 0;
1891 	}
1892 	return err;
1893 }
1894 
1895 const struct got_error *
1896 got_packfile_extract_raw_delta(uint8_t **delta_buf, size_t *delta_size,
1897     size_t *delta_compressed_size, off_t *delta_offset,
1898     off_t *delta_data_offset, off_t *base_offset,
1899     struct got_object_id *base_id, uint64_t *base_size, uint64_t *result_size,
1900     struct got_pack *pack, struct got_packidx *packidx, int idx)
1901 {
1902 	const struct got_error *err = NULL;
1903 	off_t offset;
1904 	uint8_t type;
1905 	uint64_t size;
1906 	size_t tslen, delta_hdrlen;
1907 
1908 	*delta_buf = NULL;
1909 	*delta_size = 0;
1910 	*delta_compressed_size = 0;
1911 	*delta_offset = 0;
1912 	*delta_data_offset = 0;
1913 	*base_offset = 0;
1914 	*base_size = 0;
1915 	*result_size = 0;
1916 
1917 	offset = got_packidx_get_object_offset(packidx, idx);
1918 	if (offset == -1)
1919 		return got_error(GOT_ERR_BAD_PACKIDX);
1920 
1921 	if (offset >= pack->filesize)
1922 		return got_error(GOT_ERR_PACK_OFFSET);
1923 
1924 	err = got_pack_parse_object_type_and_size(&type, &size, &tslen,
1925 	    pack, offset);
1926 	if (err)
1927 		return err;
1928 
1929 	if (tslen + size < tslen || offset + size < size ||
1930 	    tslen + offset < tslen)
1931 		return got_error(GOT_ERR_PACK_OFFSET);
1932 
1933 	switch (type) {
1934 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1935 		err = got_pack_parse_offset_delta(base_offset, &delta_hdrlen,
1936 		    pack, offset, tslen);
1937 		if (err)
1938 			return err;
1939 		break;
1940 	case GOT_OBJ_TYPE_REF_DELTA:
1941 		err = got_pack_parse_ref_delta(base_id, pack, offset, tslen);
1942 		if (err)
1943 			return err;
1944 		delta_hdrlen = SHA1_DIGEST_LENGTH;
1945 		break;
1946 	default:
1947 		return got_error_fmt(GOT_ERR_OBJ_TYPE,
1948 		    "non-delta object type %d found at offset %lld",
1949 		    type, (long long)offset);
1950 	}
1951 
1952 	if (tslen + delta_hdrlen < delta_hdrlen ||
1953 	    offset + delta_hdrlen < delta_hdrlen)
1954 		return got_error(GOT_ERR_BAD_DELTA);
1955 
1956 	*delta_data_offset = offset + tslen + delta_hdrlen;
1957 	err = read_raw_delta_data(delta_buf, delta_size, delta_compressed_size,
1958 	    base_size, result_size, *delta_data_offset, pack, packidx);
1959 	if (err)
1960 		return err;
1961 
1962 	if (*delta_size != size) {
1963 		err = got_error(GOT_ERR_BAD_DELTA);
1964 		goto done;
1965 	}
1966 
1967 	*delta_offset = offset;
1968 done:
1969 	if (err) {
1970 		free(*delta_buf);
1971 		*delta_buf = NULL;
1972 		*delta_size = 0;
1973 		*delta_compressed_size = 0;
1974 		*delta_offset = 0;
1975 		*base_offset = 0;
1976 		*base_size = 0;
1977 		*result_size = 0;
1978 	}
1979 	return err;
1980 }