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Date:: Tue May 31 11:00:09 2022 UTC
Message:: open temporary files needed for delta application in got_repo_open() This prepares for callers of got_repo_open() that cannot afford to open files in /tmp, such as gotwebd. In a follow-up change, we could ask such callers to pass in the required amount of open temporary files. One consequence is that got_repo_open() now requires the "cpath" pledge promise. Add the "cpath" promise to affected callers and remove it once the repository has been opened. ok tracey
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1 /*
2  * Copyright (c) 2018, 2019, 2020 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <sys/stat.h>
19 #include <sys/queue.h>
20 #include <sys/uio.h>
21 #include <sys/mman.h>
22 
23 #include <fcntl.h>
24 #include <errno.h>
25 #include <stdio.h>
26 #include <stdint.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <limits.h>
30 #include <sha1.h>
31 #include <endian.h>
32 #include <unistd.h>
33 #include <zlib.h>
34 #include <imsg.h>
35 
36 #include "got_error.h"
37 #include "got_object.h"
38 #include "got_path.h"
39 
40 #include "got_lib_sha1.h"
41 #include "got_lib_delta.h"
42 #include "got_lib_delta_cache.h"
43 #include "got_lib_inflate.h"
44 #include "got_lib_object.h"
45 #include "got_lib_object_parse.h"
46 #include "got_lib_privsep.h"
47 #include "got_lib_pack.h"
48 
49 #ifndef nitems
50 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
51 #endif
52 
53 #ifndef MIN
54 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
55 #endif
56 
57 static const struct got_error *
58 verify_fanout_table(uint32_t *fanout_table)
59 {
60 	int i;
61 
62 	for (i = 0; i < 0xff - 1; i++) {
63 		if (be32toh(fanout_table[i]) > be32toh(fanout_table[i + 1]))
64 			return got_error(GOT_ERR_BAD_PACKIDX);
65 	}
66 
67 	return NULL;
68 }
69 
70 const struct got_error *
71 got_packidx_init_hdr(struct got_packidx *p, int verify, off_t packfile_size)
72 {
73 	const struct got_error *err = NULL;
74 	struct got_packidx_v2_hdr *h;
75 	SHA1_CTX ctx;
76 	uint8_t sha1[SHA1_DIGEST_LENGTH];
77 	size_t nobj, len_fanout, len_ids, offset, remain;
78 	ssize_t n;
79 	int i;
80 
81 	SHA1Init(&ctx);
82 
83 	h = &p->hdr;
84 	offset = 0;
85 	remain = p->len;
86 
87 	if (remain < sizeof(*h->magic)) {
88 		err = got_error(GOT_ERR_BAD_PACKIDX);
89 		goto done;
90 	}
91 	if (p->map)
92 		h->magic = (uint32_t *)(p->map + offset);
93 	else {
94 		h->magic = malloc(sizeof(*h->magic));
95 		if (h->magic == NULL) {
96 			err = got_error_from_errno("malloc");
97 			goto done;
98 		}
99 		n = read(p->fd, h->magic, sizeof(*h->magic));
100 		if (n < 0) {
101 			err = got_error_from_errno("read");
102 			goto done;
103 		} else if (n != sizeof(*h->magic)) {
104 			err = got_error(GOT_ERR_BAD_PACKIDX);
105 			goto done;
106 		}
107 	}
108 	if (*h->magic != htobe32(GOT_PACKIDX_V2_MAGIC)) {
109 		err = got_error(GOT_ERR_BAD_PACKIDX);
110 		goto done;
111 	}
112 	offset += sizeof(*h->magic);
113 	remain -= sizeof(*h->magic);
114 
115 	if (verify)
116 		SHA1Update(&ctx, (uint8_t *)h->magic, sizeof(*h->magic));
117 
118 	if (remain < sizeof(*h->version)) {
119 		err = got_error(GOT_ERR_BAD_PACKIDX);
120 		goto done;
121 	}
122 	if (p->map)
123 		h->version = (uint32_t *)(p->map + offset);
124 	else {
125 		h->version = malloc(sizeof(*h->version));
126 		if (h->version == NULL) {
127 			err = got_error_from_errno("malloc");
128 			goto done;
129 		}
130 		n = read(p->fd, h->version, sizeof(*h->version));
131 		if (n < 0) {
132 			err = got_error_from_errno("read");
133 			goto done;
134 		} else if (n != sizeof(*h->version)) {
135 			err = got_error(GOT_ERR_BAD_PACKIDX);
136 			goto done;
137 		}
138 	}
139 	if (*h->version != htobe32(GOT_PACKIDX_VERSION)) {
140 		err = got_error(GOT_ERR_BAD_PACKIDX);
141 		goto done;
142 	}
143 	offset += sizeof(*h->version);
144 	remain -= sizeof(*h->version);
145 
146 	if (verify)
147 		SHA1Update(&ctx, (uint8_t *)h->version, sizeof(*h->version));
148 
149 	len_fanout =
150 	    sizeof(*h->fanout_table) * GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS;
151 	if (remain < len_fanout) {
152 		err = got_error(GOT_ERR_BAD_PACKIDX);
153 		goto done;
154 	}
155 	if (p->map)
156 		h->fanout_table = (uint32_t *)(p->map + offset);
157 	else {
158 		h->fanout_table = malloc(len_fanout);
159 		if (h->fanout_table == NULL) {
160 			err = got_error_from_errno("malloc");
161 			goto done;
162 		}
163 		n = read(p->fd, h->fanout_table, len_fanout);
164 		if (n < 0) {
165 			err = got_error_from_errno("read");
166 			goto done;
167 		} else if (n != len_fanout) {
168 			err = got_error(GOT_ERR_BAD_PACKIDX);
169 			goto done;
170 		}
171 	}
172 	err = verify_fanout_table(h->fanout_table);
173 	if (err)
174 		goto done;
175 	if (verify)
176 		SHA1Update(&ctx, (uint8_t *)h->fanout_table, len_fanout);
177 	offset += len_fanout;
178 	remain -= len_fanout;
179 
180 	nobj = be32toh(h->fanout_table[0xff]);
181 	len_ids = nobj * sizeof(*h->sorted_ids);
182 	if (len_ids <= nobj || len_ids > remain) {
183 		err = got_error(GOT_ERR_BAD_PACKIDX);
184 		goto done;
185 	}
186 	if (p->map)
187 		h->sorted_ids =
188 		    (struct got_packidx_object_id *)((uint8_t*)(p->map + offset));
189 	else {
190 		h->sorted_ids = malloc(len_ids);
191 		if (h->sorted_ids == NULL) {
192 			err = got_error(GOT_ERR_BAD_PACKIDX);
193 			goto done;
194 		}
195 		n = read(p->fd, h->sorted_ids, len_ids);
196 		if (n < 0)
197 			err = got_error_from_errno("read");
198 		else if (n != len_ids) {
199 			err = got_error(GOT_ERR_BAD_PACKIDX);
200 			goto done;
201 		}
202 	}
203 	if (verify)
204 		SHA1Update(&ctx, (uint8_t *)h->sorted_ids, len_ids);
205 	offset += len_ids;
206 	remain -= len_ids;
207 
208 	if (remain < nobj * sizeof(*h->crc32)) {
209 		err = got_error(GOT_ERR_BAD_PACKIDX);
210 		goto done;
211 	}
212 	if (p->map)
213 		h->crc32 = (uint32_t *)((uint8_t*)(p->map + offset));
214 	else {
215 		h->crc32 = malloc(nobj * sizeof(*h->crc32));
216 		if (h->crc32 == NULL) {
217 			err = got_error_from_errno("malloc");
218 			goto done;
219 		}
220 		n = read(p->fd, h->crc32, nobj * sizeof(*h->crc32));
221 		if (n < 0)
222 			err = got_error_from_errno("read");
223 		else if (n != nobj * sizeof(*h->crc32)) {
224 			err = got_error(GOT_ERR_BAD_PACKIDX);
225 			goto done;
226 		}
227 	}
228 	if (verify)
229 		SHA1Update(&ctx, (uint8_t *)h->crc32, nobj * sizeof(*h->crc32));
230 	remain -= nobj * sizeof(*h->crc32);
231 	offset += nobj * sizeof(*h->crc32);
232 
233 	if (remain < nobj * sizeof(*h->offsets)) {
234 		err = got_error(GOT_ERR_BAD_PACKIDX);
235 		goto done;
236 	}
237 	if (p->map)
238 		h->offsets = (uint32_t *)((uint8_t*)(p->map + offset));
239 	else {
240 		h->offsets = malloc(nobj * sizeof(*h->offsets));
241 		if (h->offsets == NULL) {
242 			err = got_error_from_errno("malloc");
243 			goto done;
244 		}
245 		n = read(p->fd, h->offsets, nobj * sizeof(*h->offsets));
246 		if (n < 0)
247 			err = got_error_from_errno("read");
248 		else if (n != nobj * sizeof(*h->offsets)) {
249 			err = got_error(GOT_ERR_BAD_PACKIDX);
250 			goto done;
251 		}
252 	}
253 	if (verify)
254 		SHA1Update(&ctx, (uint8_t *)h->offsets,
255 		    nobj * sizeof(*h->offsets));
256 	remain -= nobj * sizeof(*h->offsets);
257 	offset += nobj * sizeof(*h->offsets);
258 
259 	/* Large file offsets are contained only in files > 2GB. */
260 	if (verify || packfile_size > 0x7fffffff) {
261 		for (i = 0; i < nobj; i++) {
262 			uint32_t o = h->offsets[i];
263 			if (o & htobe32(GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX))
264 				p->nlargeobj++;
265 		}
266 	}
267 	if (p->nlargeobj == 0)
268 		goto checksum;
269 	else if (packfile_size <= 0x7fffffff) {
270 		err = got_error(GOT_ERR_BAD_PACKIDX);
271 		goto done;
272 	}
273 
274 	if (remain < p->nlargeobj * sizeof(*h->large_offsets)) {
275 		err = got_error(GOT_ERR_BAD_PACKIDX);
276 		goto done;
277 	}
278 	if (p->map)
279 		h->large_offsets = (uint64_t *)((uint8_t*)(p->map + offset));
280 	else {
281 		h->large_offsets = malloc(p->nlargeobj *
282 		    sizeof(*h->large_offsets));
283 		if (h->large_offsets == NULL) {
284 			err = got_error_from_errno("malloc");
285 			goto done;
286 		}
287 		n = read(p->fd, h->large_offsets,
288 		    p->nlargeobj * sizeof(*h->large_offsets));
289 		if (n < 0)
290 			err = got_error_from_errno("read");
291 		else if (n != p->nlargeobj * sizeof(*h->large_offsets)) {
292 			err = got_error(GOT_ERR_BAD_PACKIDX);
293 			goto done;
294 		}
295 	}
296 	if (verify)
297 		SHA1Update(&ctx, (uint8_t*)h->large_offsets,
298 		    p->nlargeobj * sizeof(*h->large_offsets));
299 	remain -= p->nlargeobj * sizeof(*h->large_offsets);
300 	offset += p->nlargeobj * sizeof(*h->large_offsets);
301 
302 checksum:
303 	if (remain < sizeof(*h->trailer)) {
304 		err = got_error(GOT_ERR_BAD_PACKIDX);
305 		goto done;
306 	}
307 	if (p->map)
308 		h->trailer =
309 		    (struct got_packidx_trailer *)((uint8_t*)(p->map + offset));
310 	else {
311 		h->trailer = malloc(sizeof(*h->trailer));
312 		if (h->trailer == NULL) {
313 			err = got_error_from_errno("malloc");
314 			goto done;
315 		}
316 		n = read(p->fd, h->trailer, sizeof(*h->trailer));
317 		if (n < 0)
318 			err = got_error_from_errno("read");
319 		else if (n != sizeof(*h->trailer)) {
320 			err = got_error(GOT_ERR_BAD_PACKIDX);
321 			goto done;
322 		}
323 	}
324 	if (verify) {
325 		SHA1Update(&ctx, h->trailer->packfile_sha1, SHA1_DIGEST_LENGTH);
326 		SHA1Final(sha1, &ctx);
327 		if (memcmp(h->trailer->packidx_sha1, sha1,
328 		    SHA1_DIGEST_LENGTH) != 0)
329 			err = got_error(GOT_ERR_PACKIDX_CSUM);
330 	}
331 done:
332 	return err;
333 }
334 
335 const struct got_error *
336 got_packidx_open(struct got_packidx **packidx,
337     int dir_fd, const char *relpath, int verify)
338 {
339 	const struct got_error *err = NULL;
340 	struct got_packidx *p = NULL;
341 	char *pack_relpath;
342 	struct stat idx_sb, pack_sb;
343 
344 	*packidx = NULL;
345 
346 	err = got_packidx_get_packfile_path(&pack_relpath, relpath);
347 	if (err)
348 		return err;
349 
350 	/*
351 	 * Ensure that a corresponding pack file exists.
352 	 * Some Git repositories have this problem. Git seems to ignore
353 	 * the existence of lonely pack index files but we do not.
354 	 */
355 	if (fstatat(dir_fd, pack_relpath, &pack_sb, 0) == -1) {
356 		if (errno == ENOENT) {
357 			err = got_error_fmt(GOT_ERR_LONELY_PACKIDX,
358 			    "%s", relpath);
359 		} else
360 			err = got_error_from_errno2("fstatat", pack_relpath);
361 		goto done;
362 	}
363 
364 	p = calloc(1, sizeof(*p));
365 	if (p == NULL) {
366 		err = got_error_from_errno("calloc");
367 		goto done;
368 	}
369 
370 	p->fd = openat(dir_fd, relpath, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
371 	if (p->fd == -1) {
372 		err = got_error_from_errno2("openat", relpath);
373 		goto done;
374 	}
375 
376 	if (fstat(p->fd, &idx_sb) != 0) {
377 		err = got_error_from_errno2("fstat", relpath);
378 		goto done;
379 	}
380 	p->len = idx_sb.st_size;
381 	if (p->len < sizeof(p->hdr)) {
382 		err = got_error(GOT_ERR_BAD_PACKIDX);
383 		goto done;
384 	}
385 
386 	p->path_packidx = strdup(relpath);
387 	if (p->path_packidx == NULL) {
388 		err = got_error_from_errno("strdup");
389 		goto done;
390 	}
391 
392 #ifndef GOT_PACK_NO_MMAP
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 #endif
402 
403 	err = got_packidx_init_hdr(p, verify, pack_sb.st_size);
404 done:
405 	if (err) {
406 		if (p)
407 			got_packidx_close(p);
408 	} else
409 		*packidx = p;
410 	free(pack_relpath);
411 	return err;
412 }
413 
414 const struct got_error *
415 got_packidx_close(struct got_packidx *packidx)
416 {
417 	const struct got_error *err = NULL;
418 
419 	free(packidx->path_packidx);
420 	if (packidx->map) {
421 		if (munmap(packidx->map, packidx->len) == -1)
422 			err = got_error_from_errno("munmap");
423 	} else {
424 		free(packidx->hdr.magic);
425 		free(packidx->hdr.version);
426 		free(packidx->hdr.fanout_table);
427 		free(packidx->hdr.sorted_ids);
428 		free(packidx->hdr.crc32);
429 		free(packidx->hdr.offsets);
430 		free(packidx->hdr.large_offsets);
431 		free(packidx->hdr.trailer);
432 	}
433 	if (close(packidx->fd) == -1 && err == NULL)
434 		err = got_error_from_errno("close");
435 	free(packidx->sorted_offsets);
436 	free(packidx->sorted_large_offsets);
437 	free(packidx);
438 
439 	return err;
440 }
441 
442 const struct got_error *
443 got_packidx_get_packfile_path(char **path_packfile, const char *path_packidx)
444 {
445 	size_t size;
446 
447 	/* Packfile path contains ".pack" instead of ".idx", so add one byte. */
448 	size = strlen(path_packidx) + 2;
449 	if (size < GOT_PACKFILE_NAMELEN + 1)
450 		return got_error_path(path_packidx, GOT_ERR_BAD_PATH);
451 
452 	*path_packfile = malloc(size);
453 	if (*path_packfile == NULL)
454 		return got_error_from_errno("malloc");
455 
456 	/* Copy up to and excluding ".idx". */
457 	if (strlcpy(*path_packfile, path_packidx,
458 	    size - strlen(GOT_PACKIDX_SUFFIX) - 1) >= size)
459 		return got_error(GOT_ERR_NO_SPACE);
460 
461 	if (strlcat(*path_packfile, GOT_PACKFILE_SUFFIX, size) >= size)
462 		return got_error(GOT_ERR_NO_SPACE);
463 
464 	return NULL;
465 }
466 
467 off_t
468 got_packidx_get_object_offset(struct got_packidx *packidx, int idx)
469 {
470 	uint32_t offset = be32toh(packidx->hdr.offsets[idx]);
471 	if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
472 		uint64_t loffset;
473 		idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
474 		if (idx < 0 || idx >= packidx->nlargeobj ||
475 		    packidx->hdr.large_offsets == NULL)
476 			return -1;
477 		loffset = be64toh(packidx->hdr.large_offsets[idx]);
478 		return (loffset > INT64_MAX ? -1 : (off_t)loffset);
479 	}
480 	return (off_t)(offset & GOT_PACKIDX_OFFSET_VAL_MASK);
481 }
482 
483 int
484 got_packidx_get_object_idx(struct got_packidx *packidx,
485     struct got_object_id *id)
486 {
487 	u_int8_t id0 = id->sha1[0];
488 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
489 	int left = 0, right = totobj - 1;
490 
491 	if (id0 > 0)
492 		left = be32toh(packidx->hdr.fanout_table[id0 - 1]);
493 
494 	while (left <= right) {
495 		struct got_packidx_object_id *oid;
496 		int i, cmp;
497 
498 		i = ((left + right) / 2);
499 		oid = &packidx->hdr.sorted_ids[i];
500 		cmp = memcmp(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
501 		if (cmp == 0)
502 			return i;
503 		else if (cmp > 0)
504 			left = i + 1;
505 		else if (cmp < 0)
506 			right = i - 1;
507 	}
508 
509 	return -1;
510 }
511 
512 static int
513 offset_cmp(const void *pa, const void *pb)
514 {
515 	const struct got_pack_offset_index *a, *b;
516 
517 	a = (const struct got_pack_offset_index *)pa;
518 	b = (const struct got_pack_offset_index *)pb;
519 
520 	if (a->offset < b->offset)
521 		return -1;
522 	else if (a->offset > b->offset)
523 		return 1;
524 
525 	return 0;
526 }
527 
528 static int
529 large_offset_cmp(const void *pa, const void *pb)
530 {
531 	const struct got_pack_large_offset_index *a, *b;
532 
533 	a = (const struct got_pack_large_offset_index *)pa;
534 	b = (const struct got_pack_large_offset_index *)pb;
535 
536 	if (a->offset < b->offset)
537 		return -1;
538 	else if (a->offset > b->offset)
539 		return 1;
540 
541 	return 0;
542 }
543 
544 static const struct got_error *
545 build_offset_index(struct got_packidx *p)
546 {
547 	uint32_t nobj = be32toh(p->hdr.fanout_table[0xff]);
548 	unsigned int i, j, k;
549 
550 	p->sorted_offsets = calloc(nobj - p->nlargeobj,
551 	    sizeof(p->sorted_offsets[0]));
552 	if (p->sorted_offsets == NULL)
553 		return got_error_from_errno("calloc");
554 
555 	if (p->nlargeobj > 0) {
556 		p->sorted_large_offsets = calloc(p->nlargeobj,
557 		    sizeof(p->sorted_large_offsets[0]));
558 		if (p->sorted_large_offsets == NULL)
559 			return got_error_from_errno("calloc");
560 	}
561 
562 	j = 0;
563 	k = 0;
564 	for (i = 0; i < nobj; i++) {
565 		uint32_t offset = be32toh(p->hdr.offsets[i]);
566 		if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
567 			uint64_t loffset;
568 			uint32_t idx;
569 			idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
570 			if (idx >= p->nlargeobj ||
571 			    p->nlargeobj == 0 ||
572 			    p->hdr.large_offsets == NULL)
573 				return got_error(GOT_ERR_BAD_PACKIDX);
574 			loffset = be64toh(p->hdr.large_offsets[idx]);
575 			p->sorted_large_offsets[j].offset = loffset;
576 			p->sorted_large_offsets[j].idx = i;
577 			j++;
578 		} else {
579 			p->sorted_offsets[k].offset = offset;
580 			p->sorted_offsets[k].idx = i;
581 			k++;
582 		}
583 	}
584 	if (j != p->nlargeobj || k != nobj - p->nlargeobj)
585 		return got_error(GOT_ERR_BAD_PACKIDX);
586 
587 	qsort(p->sorted_offsets, nobj - p->nlargeobj,
588 	    sizeof(p->sorted_offsets[0]), offset_cmp);
589 
590 	if (p->sorted_large_offsets)
591 		qsort(p->sorted_large_offsets, p->nlargeobj,
592 		    sizeof(p->sorted_large_offsets[0]), large_offset_cmp);
593 
594 	return NULL;
595 }
596 
597 const struct got_error *
598 got_packidx_get_offset_idx(int *idx, struct got_packidx *packidx, off_t offset)
599 {
600 	const struct got_error *err;
601 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
602 	int i, left, right;
603 
604 	*idx = -1;
605 
606 	if (packidx->sorted_offsets == NULL) {
607 		err = build_offset_index(packidx);
608 		if (err)
609 			return err;
610 	}
611 
612 	if (offset >= 0x7fffffff) {
613 		uint64_t lo;
614 		left = 0, right = packidx->nlargeobj - 1;
615 		while (left <= right) {
616 			i = ((left + right) / 2);
617 			lo = packidx->sorted_large_offsets[i].offset;
618 			if (lo == offset) {
619 				*idx = packidx->sorted_large_offsets[i].idx;
620 				break;
621 			} else if (offset > lo)
622 				left = i + 1;
623 			else if (offset < lo)
624 				right = i - 1;
625 		}
626 	} else {
627 		uint32_t o;
628 		left = 0, right = totobj - packidx->nlargeobj - 1;
629 		while (left <= right) {
630 			i = ((left + right) / 2);
631 			o = packidx->sorted_offsets[i].offset;
632 			if (o == offset) {
633 				*idx = packidx->sorted_offsets[i].idx;
634 				break;
635 			} else if (offset > o)
636 				left = i + 1;
637 			else if (offset < o)
638 				right = i - 1;
639 		}
640 	}
641 
642 	return NULL;
643 }
644 
645 const struct got_error *
646 got_packidx_get_object_id(struct got_object_id *id,
647     struct got_packidx *packidx, int idx)
648 {
649 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
650 	struct got_packidx_object_id *oid;
651 
652 	if (idx < 0 || idx >= totobj)
653 		return got_error(GOT_ERR_NO_OBJ);
654 
655 	oid = &packidx->hdr.sorted_ids[idx];
656 	memcpy(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
657 	return NULL;
658 }
659 
660 const struct got_error *
661 got_packidx_match_id_str_prefix(struct got_object_id_queue *matched_ids,
662     struct got_packidx *packidx, const char *id_str_prefix)
663 {
664 	const struct got_error *err = NULL;
665 	u_int8_t id0;
666 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
667 	char hex[3];
668 	size_t prefix_len = strlen(id_str_prefix);
669 	struct got_packidx_object_id *oid;
670 	uint32_t i = 0;
671 
672 	STAILQ_INIT(matched_ids);
673 
674 	if (prefix_len < 2)
675 		return got_error_path(id_str_prefix, GOT_ERR_BAD_OBJ_ID_STR);
676 
677 	hex[0] = id_str_prefix[0];
678 	hex[1] = id_str_prefix[1];
679 	hex[2] = '\0';
680 	if (!got_parse_xdigit(&id0, hex))
681 		return got_error_path(id_str_prefix, GOT_ERR_BAD_OBJ_ID_STR);
682 
683 	if (id0 > 0)
684 		i = be32toh(packidx->hdr.fanout_table[id0 - 1]);
685 	oid = &packidx->hdr.sorted_ids[i];
686 	while (i < totobj && oid->sha1[0] == id0) {
687 		char id_str[SHA1_DIGEST_STRING_LENGTH];
688 		struct got_object_qid *qid;
689 		int cmp;
690 
691 		if (!got_sha1_digest_to_str(oid->sha1, id_str, sizeof(id_str)))
692 		        return got_error(GOT_ERR_NO_SPACE);
693 
694 		cmp = strncmp(id_str, id_str_prefix, prefix_len);
695 		if (cmp < 0) {
696 			oid = &packidx->hdr.sorted_ids[++i];
697 			continue;
698 		} else if (cmp > 0)
699 			break;
700 
701 		err = got_object_qid_alloc_partial(&qid);
702 		if (err)
703 			break;
704 		memcpy(qid->id.sha1, oid->sha1, SHA1_DIGEST_LENGTH);
705 		STAILQ_INSERT_TAIL(matched_ids, qid, entry);
706 
707 		oid = &packidx->hdr.sorted_ids[++i];
708 	}
709 
710 	if (err)
711 		got_object_id_queue_free(matched_ids);
712 	return err;
713 }
714 
715 static const struct got_error *
716 pack_stop_privsep_child(struct got_pack *pack)
717 {
718 	const struct got_error *err = NULL;
719 
720 	if (pack->privsep_child == NULL)
721 		return NULL;
722 
723 	err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
724 	if (err)
725 		return err;
726 	err = got_privsep_wait_for_child(pack->privsep_child->pid);
727 	if (close(pack->privsep_child->imsg_fd) == -1 && err == NULL)
728 		err = got_error_from_errno("close");
729 	free(pack->privsep_child->ibuf);
730 	free(pack->privsep_child);
731 	pack->privsep_child = NULL;
732 	return err;
733 }
734 
735 const struct got_error *
736 got_pack_close(struct got_pack *pack)
737 {
738 	const struct got_error *err = NULL;
739 
740 	err = pack_stop_privsep_child(pack);
741 	if (pack->map && munmap(pack->map, pack->filesize) == -1 && !err)
742 		err = got_error_from_errno("munmap");
743 	if (pack->fd != -1 && close(pack->fd) == -1 && err == NULL)
744 		err = got_error_from_errno("close");
745 	pack->fd = -1;
746 	free(pack->path_packfile);
747 	pack->path_packfile = NULL;
748 	pack->filesize = 0;
749 	if (pack->delta_cache) {
750 		got_delta_cache_free(pack->delta_cache);
751 		pack->delta_cache = NULL;
752 	}
753 
754 	/*
755 	 * Leave accumfd and basefd alone. They are managed by the
756 	 * repository layer and can be reused.
757 	 */
758 
759 	return err;
760 }
761 
762 const struct got_error *
763 got_pack_parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len,
764     struct got_pack *pack, off_t offset)
765 {
766 	uint8_t t = 0;
767 	uint64_t s = 0;
768 	uint8_t sizeN;
769 	size_t mapoff = 0;
770 	int i = 0;
771 
772 	*len = 0;
773 
774 	if (offset >= pack->filesize)
775 		return got_error(GOT_ERR_PACK_OFFSET);
776 
777 	if (pack->map) {
778 		mapoff = (size_t)offset;
779 	} else {
780 		if (lseek(pack->fd, offset, SEEK_SET) == -1)
781 			return got_error_from_errno("lseek");
782 	}
783 
784 	do {
785 		/* We do not support size values which don't fit in 64 bit. */
786 		if (i > 9)
787 			return got_error(GOT_ERR_NO_SPACE);
788 
789 		if (pack->map) {
790 			if (mapoff + sizeof(sizeN) >= pack->filesize)
791 				return got_error(GOT_ERR_BAD_PACKFILE);
792 			sizeN = *(pack->map + mapoff);
793 			mapoff += sizeof(sizeN);
794 		} else {
795 			ssize_t n = read(pack->fd, &sizeN, sizeof(sizeN));
796 			if (n < 0)
797 				return got_error_from_errno("read");
798 			if (n != sizeof(sizeN))
799 				return got_error(GOT_ERR_BAD_PACKFILE);
800 		}
801 		*len += sizeof(sizeN);
802 
803 		if (i == 0) {
804 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
805 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
806 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
807 		} else {
808 			size_t shift = 4 + 7 * (i - 1);
809 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
810 		}
811 		i++;
812 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
813 
814 	*type = t;
815 	*size = s;
816 	return NULL;
817 }
818 
819 static const struct got_error *
820 open_plain_object(struct got_object **obj, struct got_object_id *id,
821     uint8_t type, off_t offset, size_t size, int idx)
822 {
823 	*obj = calloc(1, sizeof(**obj));
824 	if (*obj == NULL)
825 		return got_error_from_errno("calloc");
826 
827 	(*obj)->type = type;
828 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
829 	(*obj)->pack_idx = idx;
830 	(*obj)->hdrlen = 0;
831 	(*obj)->size = size;
832 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
833 	(*obj)->pack_offset = offset;
834 
835 	return NULL;
836 }
837 
838 static const struct got_error *
839 parse_negative_offset(int64_t *offset, size_t *len, struct got_pack *pack,
840     off_t delta_offset)
841 {
842 	int64_t o = 0;
843 	uint8_t offN;
844 	int i = 0;
845 
846 	*offset = 0;
847 	*len = 0;
848 
849 	do {
850 		/* We do not support offset values which don't fit in 64 bit. */
851 		if (i > 8)
852 			return got_error(GOT_ERR_NO_SPACE);
853 
854 		if (pack->map) {
855 			size_t mapoff;
856 			mapoff = (size_t)delta_offset + *len;
857 			if (mapoff + sizeof(offN) >= pack->filesize)
858 				return got_error(GOT_ERR_PACK_OFFSET);
859 			offN = *(pack->map + mapoff);
860 		} else {
861 			ssize_t n;
862 			n = read(pack->fd, &offN, sizeof(offN));
863 			if (n < 0)
864 				return got_error_from_errno("read");
865 			if (n != sizeof(offN))
866 				return got_error(GOT_ERR_BAD_PACKFILE);
867 		}
868 		*len += sizeof(offN);
869 
870 		if (i == 0)
871 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
872 		else {
873 			o++;
874 			o <<= 7;
875 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
876 		}
877 		i++;
878 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
879 
880 	*offset = o;
881 	return NULL;
882 }
883 
884 const struct got_error *
885 got_pack_parse_offset_delta(off_t *base_offset, size_t *len,
886     struct got_pack *pack, off_t offset, int tslen)
887 {
888 	const struct got_error *err;
889 	int64_t negoffset;
890 	size_t negofflen;
891 
892 	*len = 0;
893 
894 	err = parse_negative_offset(&negoffset, &negofflen, pack,
895 	    offset + tslen);
896 	if (err)
897 		return err;
898 
899 	/* Compute the base object's offset (must be in the same pack file). */
900 	*base_offset = (offset - negoffset);
901 	if (*base_offset <= 0)
902 		return got_error(GOT_ERR_BAD_PACKFILE);
903 
904 	*len = negofflen;
905 	return NULL;
906 }
907 
908 static const struct got_error *
909 read_delta_data(uint8_t **delta_buf, size_t *delta_len,
910     size_t *delta_compressed_len, size_t delta_data_offset,
911     struct got_pack *pack)
912 {
913 	const struct got_error *err = NULL;
914 	size_t consumed = 0;
915 
916 	if (pack->map) {
917 		if (delta_data_offset >= pack->filesize)
918 			return got_error(GOT_ERR_PACK_OFFSET);
919 		err = got_inflate_to_mem_mmap(delta_buf, delta_len,
920 		    &consumed, NULL, pack->map, delta_data_offset,
921 		    pack->filesize - delta_data_offset);
922 		if (err)
923 			return err;
924 	} else {
925 		if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1)
926 			return got_error_from_errno("lseek");
927 		err = got_inflate_to_mem_fd(delta_buf, delta_len,
928 		    &consumed, NULL, 0, pack->fd);
929 		if (err)
930 			return err;
931 	}
932 
933 	if (delta_compressed_len)
934 		*delta_compressed_len = consumed;
935 
936 	return NULL;
937 }
938 
939 static const struct got_error *
940 add_delta(struct got_delta_chain *deltas, off_t delta_offset, size_t tslen,
941     int delta_type, size_t delta_size, size_t delta_data_offset)
942 {
943 	struct got_delta *delta;
944 
945 	delta = got_delta_open(delta_offset, tslen, delta_type, delta_size,
946 	    delta_data_offset);
947 	if (delta == NULL)
948 		return got_error_from_errno("got_delta_open");
949 	/* delta is freed in got_object_close() */
950 	deltas->nentries++;
951 	STAILQ_INSERT_HEAD(&deltas->entries, delta, entry);
952 	return NULL;
953 }
954 
955 static const struct got_error *
956 resolve_offset_delta(struct got_delta_chain *deltas,
957     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
958     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
959 
960 {
961 	const struct got_error *err;
962 	off_t base_offset;
963 	uint8_t base_type;
964 	uint64_t base_size;
965 	size_t base_tslen;
966 	off_t delta_data_offset;
967 	size_t consumed;
968 
969 	err = got_pack_parse_offset_delta(&base_offset, &consumed, pack,
970 	    delta_offset, tslen);
971 	if (err)
972 		return err;
973 
974 	delta_data_offset = delta_offset + tslen + consumed;
975 	if (delta_data_offset >= pack->filesize)
976 		return got_error(GOT_ERR_PACK_OFFSET);
977 
978 	if (pack->map == NULL) {
979 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
980 		if (delta_data_offset == -1)
981 			return got_error_from_errno("lseek");
982 	}
983 
984 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
985 	    delta_data_offset);
986 	if (err)
987 		return err;
988 
989 	/* An offset delta must be in the same packfile. */
990 	if (base_offset >= pack->filesize)
991 		return got_error(GOT_ERR_PACK_OFFSET);
992 
993 	err = got_pack_parse_object_type_and_size(&base_type, &base_size,
994 	    &base_tslen, pack, base_offset);
995 	if (err)
996 		return err;
997 
998 	return got_pack_resolve_delta_chain(deltas, packidx, pack, base_offset,
999 	    base_tslen, base_type, base_size, recursion - 1);
1000 }
1001 
1002 const struct got_error *
1003 got_pack_parse_ref_delta(struct got_object_id *id,
1004     struct got_pack *pack, off_t delta_offset, int tslen)
1005 {
1006 	if (pack->map) {
1007 		size_t mapoff = delta_offset + tslen;
1008 		if (mapoff + sizeof(*id) >= pack->filesize)
1009 			return got_error(GOT_ERR_PACK_OFFSET);
1010 		memcpy(id, pack->map + mapoff, sizeof(*id));
1011 	} else {
1012 		ssize_t n;
1013 		n = read(pack->fd, id, sizeof(*id));
1014 		if (n < 0)
1015 			return got_error_from_errno("read");
1016 		if (n != sizeof(*id))
1017 			return got_error(GOT_ERR_BAD_PACKFILE);
1018 	}
1019 
1020 	return NULL;
1021 }
1022 
1023 static const struct got_error *
1024 resolve_ref_delta(struct got_delta_chain *deltas, struct got_packidx *packidx,
1025     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
1026     size_t delta_size, unsigned int recursion)
1027 {
1028 	const struct got_error *err;
1029 	struct got_object_id id;
1030 	int idx;
1031 	off_t base_offset;
1032 	uint8_t base_type;
1033 	uint64_t base_size;
1034 	size_t base_tslen;
1035 	off_t delta_data_offset;
1036 
1037 	if (delta_offset + tslen >= pack->filesize)
1038 		return got_error(GOT_ERR_PACK_OFFSET);
1039 
1040 	err = got_pack_parse_ref_delta(&id, pack, delta_offset, tslen);
1041 	if (err)
1042 		return err;
1043 	if (pack->map) {
1044 		delta_data_offset = delta_offset + tslen + sizeof(id);
1045 	} else {
1046 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
1047 		if (delta_data_offset == -1)
1048 			return got_error_from_errno("lseek");
1049 	}
1050 
1051 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
1052 	    delta_data_offset);
1053 	if (err)
1054 		return err;
1055 
1056 	/* Delta base must be in the same pack file. */
1057 	idx = got_packidx_get_object_idx(packidx, &id);
1058 	if (idx == -1)
1059 		return got_error(GOT_ERR_NO_OBJ);
1060 
1061 	base_offset = got_packidx_get_object_offset(packidx, idx);
1062 	if (base_offset == (uint64_t)-1)
1063 		return got_error(GOT_ERR_BAD_PACKIDX);
1064 
1065 	if (base_offset >= pack->filesize)
1066 		return got_error(GOT_ERR_PACK_OFFSET);
1067 
1068 	err = got_pack_parse_object_type_and_size(&base_type, &base_size,
1069 	    &base_tslen, pack, base_offset);
1070 	if (err)
1071 		return err;
1072 
1073 	return got_pack_resolve_delta_chain(deltas, packidx, pack, base_offset,
1074 	    base_tslen, base_type, base_size, recursion - 1);
1075 }
1076 
1077 const struct got_error *
1078 got_pack_resolve_delta_chain(struct got_delta_chain *deltas,
1079     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
1080     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
1081 {
1082 	const struct got_error *err = NULL;
1083 
1084 	if (--recursion == 0)
1085 		return got_error(GOT_ERR_RECURSION);
1086 
1087 	switch (delta_type) {
1088 	case GOT_OBJ_TYPE_COMMIT:
1089 	case GOT_OBJ_TYPE_TREE:
1090 	case GOT_OBJ_TYPE_BLOB:
1091 	case GOT_OBJ_TYPE_TAG:
1092 		/* Plain types are the final delta base. Recursion ends. */
1093 		err = add_delta(deltas, delta_offset, tslen, delta_type,
1094 		    delta_size, 0);
1095 		break;
1096 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1097 		err = resolve_offset_delta(deltas, packidx, pack,
1098 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
1099 		break;
1100 	case GOT_OBJ_TYPE_REF_DELTA:
1101 		err = resolve_ref_delta(deltas, packidx, pack,
1102 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
1103 		break;
1104 	default:
1105 		return got_error(GOT_ERR_OBJ_TYPE);
1106 	}
1107 
1108 	return err;
1109 }
1110 
1111 static const struct got_error *
1112 open_delta_object(struct got_object **obj, struct got_packidx *packidx,
1113     struct got_pack *pack, struct got_object_id *id, off_t offset,
1114     size_t tslen, int delta_type, size_t delta_size, int idx)
1115 {
1116 	const struct got_error *err = NULL;
1117 	int resolved_type;
1118 
1119 	*obj = calloc(1, sizeof(**obj));
1120 	if (*obj == NULL)
1121 		return got_error_from_errno("calloc");
1122 
1123 	(*obj)->flags = 0;
1124 	(*obj)->hdrlen = 0;
1125 	(*obj)->size = 0; /* Not known because deltas aren't applied yet. */
1126 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
1127 	(*obj)->pack_offset = offset + tslen;
1128 
1129 	STAILQ_INIT(&(*obj)->deltas.entries);
1130 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
1131 	(*obj)->flags |= GOT_OBJ_FLAG_PACKED;
1132 	(*obj)->pack_idx = idx;
1133 
1134 	err = got_pack_resolve_delta_chain(&(*obj)->deltas, packidx, pack,
1135 	    offset, tslen, delta_type, delta_size,
1136 	    GOT_DELTA_CHAIN_RECURSION_MAX);
1137 	if (err)
1138 		goto done;
1139 
1140 	err = got_delta_chain_get_base_type(&resolved_type, &(*obj)->deltas);
1141 	if (err)
1142 		goto done;
1143 	(*obj)->type = resolved_type;
1144 done:
1145 	if (err) {
1146 		got_object_close(*obj);
1147 		*obj = NULL;
1148 	}
1149 	return err;
1150 }
1151 
1152 const struct got_error *
1153 got_packfile_open_object(struct got_object **obj, struct got_pack *pack,
1154     struct got_packidx *packidx, int idx, struct got_object_id *id)
1155 {
1156 	const struct got_error *err = NULL;
1157 	off_t offset;
1158 	uint8_t type;
1159 	uint64_t size;
1160 	size_t tslen;
1161 
1162 	*obj = NULL;
1163 
1164 	offset = got_packidx_get_object_offset(packidx, idx);
1165 	if (offset == (uint64_t)-1)
1166 		return got_error(GOT_ERR_BAD_PACKIDX);
1167 
1168 	err = got_pack_parse_object_type_and_size(&type, &size, &tslen,
1169 	    pack, offset);
1170 	if (err)
1171 		return err;
1172 
1173 	switch (type) {
1174 	case GOT_OBJ_TYPE_COMMIT:
1175 	case GOT_OBJ_TYPE_TREE:
1176 	case GOT_OBJ_TYPE_BLOB:
1177 	case GOT_OBJ_TYPE_TAG:
1178 		err = open_plain_object(obj, id, type, offset + tslen,
1179 		    size, idx);
1180 		break;
1181 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1182 	case GOT_OBJ_TYPE_REF_DELTA:
1183 		err = open_delta_object(obj, packidx, pack, id, offset,
1184 		    tslen, type, size, idx);
1185 		break;
1186 	default:
1187 		err = got_error(GOT_ERR_OBJ_TYPE);
1188 		break;
1189 	}
1190 
1191 	return err;
1192 }
1193 
1194 const struct got_error *
1195 got_pack_get_delta_chain_max_size(uint64_t *max_size,
1196     struct got_delta_chain *deltas, struct got_pack *pack)
1197 {
1198 	struct got_delta *delta;
1199 	uint64_t base_size = 0, result_size = 0;
1200 
1201 	*max_size = 0;
1202 	STAILQ_FOREACH(delta, &deltas->entries, entry) {
1203 		/* Plain object types are the delta base. */
1204 		if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1205 		    delta->type != GOT_OBJ_TYPE_TREE &&
1206 		    delta->type != GOT_OBJ_TYPE_BLOB &&
1207 		    delta->type != GOT_OBJ_TYPE_TAG) {
1208 			const struct got_error *err;
1209 			uint8_t *delta_buf;
1210 			size_t delta_len;
1211 			int cached = 1;
1212 
1213 			got_delta_cache_get(&delta_buf, &delta_len,
1214 			    pack->delta_cache, delta->data_offset);
1215 			if (delta_buf == NULL) {
1216 				cached = 0;
1217 				err = read_delta_data(&delta_buf, &delta_len,
1218 				    NULL, delta->data_offset, pack);
1219 				if (err)
1220 					return err;
1221 				err = got_delta_cache_add(pack->delta_cache,
1222 				    delta->data_offset, delta_buf, delta_len);
1223 				if (err == NULL)
1224 					cached = 1;
1225 				else if (err->code != GOT_ERR_NO_SPACE) {
1226 					free(delta_buf);
1227 					return err;
1228 				}
1229 			}
1230 			err = got_delta_get_sizes(&base_size, &result_size,
1231 			    delta_buf, delta_len);
1232 			if (!cached)
1233 				free(delta_buf);
1234 			if (err)
1235 				return err;
1236 		} else
1237 			base_size = delta->size;
1238 		if (base_size > *max_size)
1239 			*max_size = base_size;
1240 		if (result_size > *max_size)
1241 			*max_size = result_size;
1242 	}
1243 
1244 	return NULL;
1245 }
1246 
1247 const struct got_error *
1248 got_pack_get_max_delta_object_size(uint64_t *size, struct got_object *obj,
1249     struct got_pack *pack)
1250 {
1251 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0)
1252 		return got_error(GOT_ERR_OBJ_TYPE);
1253 
1254 	return got_pack_get_delta_chain_max_size(size, &obj->deltas, pack);
1255 }
1256 
1257 const struct got_error *
1258 got_pack_dump_delta_chain_to_file(size_t *result_size,
1259     struct got_delta_chain *deltas, struct got_pack *pack, FILE *outfile,
1260     FILE *base_file, FILE *accum_file)
1261 {
1262 	const struct got_error *err = NULL;
1263 	struct got_delta *delta;
1264 	uint8_t *base_buf = NULL, *accum_buf = NULL, *delta_buf;
1265 	size_t base_bufsz = 0, accum_bufsz = 0, accum_size = 0, delta_len;
1266 	/* We process small enough files entirely in memory for speed. */
1267 	const size_t max_bufsize = GOT_DELTA_RESULT_SIZE_CACHED_MAX;
1268 	uint64_t max_size = 0;
1269 	int n = 0;
1270 
1271 	*result_size = 0;
1272 
1273 	if (STAILQ_EMPTY(&deltas->entries))
1274 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1275 
1276 	if (fseeko(base_file, 0L, SEEK_SET) == -1)
1277 		return got_error_from_errno("fseeko");
1278 	if (fseeko(accum_file, 0L, SEEK_SET) == -1)
1279 		return got_error_from_errno("fseeko");
1280 
1281 	/* Deltas are ordered in ascending order. */
1282 	STAILQ_FOREACH(delta, &deltas->entries, entry) {
1283 		uint64_t base_size, result_size = 0;
1284 		int cached = 1;
1285 		if (n == 0) {
1286 			size_t mapoff;
1287 			off_t delta_data_offset;
1288 
1289 			/* Plain object types are the delta base. */
1290 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1291 			    delta->type != GOT_OBJ_TYPE_TREE &&
1292 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1293 			    delta->type != GOT_OBJ_TYPE_TAG) {
1294 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1295 				goto done;
1296 			}
1297 
1298 			delta_data_offset = delta->offset + delta->tslen;
1299 			if (delta_data_offset >= pack->filesize) {
1300 				err = got_error(GOT_ERR_PACK_OFFSET);
1301 				goto done;
1302 			}
1303 			if (pack->map == NULL) {
1304 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1305 				    == -1) {
1306 					err = got_error_from_errno("lseek");
1307 					goto done;
1308 				}
1309 			}
1310 			if (delta->size > max_size)
1311 				max_size = delta->size;
1312 			if (max_size > max_bufsize) {
1313 				if (pack->map) {
1314 					mapoff = (size_t)delta_data_offset;
1315 					err = got_inflate_to_file_mmap(
1316 					    &base_bufsz, NULL, NULL, pack->map,
1317 					    mapoff, pack->filesize - mapoff,
1318 					    base_file);
1319 				} else
1320 					err = got_inflate_to_file_fd(
1321 					    &base_bufsz, NULL, NULL, pack->fd,
1322 					    base_file);
1323 			} else {
1324 				accum_buf = malloc(max_size);
1325 				if (accum_buf == NULL) {
1326 					err = got_error_from_errno("malloc");
1327 					goto done;
1328 				}
1329 				accum_bufsz = max_size;
1330 				if (pack->map) {
1331 					mapoff = (size_t)delta_data_offset;
1332 					err = got_inflate_to_mem_mmap(&base_buf,
1333 					    &base_bufsz, NULL, NULL,
1334 					    pack->map, mapoff,
1335 					    pack->filesize - mapoff);
1336 				} else
1337 					err = got_inflate_to_mem_fd(&base_buf,
1338 					    &base_bufsz, NULL, NULL, max_size,
1339 					    pack->fd);
1340 			}
1341 			if (err)
1342 				goto done;
1343 			n++;
1344 			if (base_buf == NULL)
1345 				rewind(base_file);
1346 			continue;
1347 		}
1348 
1349 		got_delta_cache_get(&delta_buf, &delta_len,
1350 		    pack->delta_cache, delta->data_offset);
1351 		if (delta_buf == NULL) {
1352 			cached = 0;
1353 			err = read_delta_data(&delta_buf, &delta_len, NULL,
1354 			    delta->data_offset, pack);
1355 			if (err)
1356 				goto done;
1357 			err = got_delta_cache_add(pack->delta_cache,
1358 			    delta->data_offset, delta_buf, delta_len);
1359 			if (err == NULL)
1360 				cached = 1;
1361 			else if (err->code != GOT_ERR_NO_SPACE) {
1362 				free(delta_buf);
1363 				goto done;
1364 			}
1365 		}
1366 
1367 		err = got_delta_get_sizes(&base_size, &result_size,
1368 		    delta_buf, delta_len);
1369 		if (err)
1370 			goto done;
1371 		if (base_size > max_size)
1372 			max_size = base_size;
1373 		if (result_size > max_size)
1374 			max_size = result_size;
1375 
1376 		if (base_buf && max_size > max_bufsize) {
1377 			/* Switch from buffers to temporary files. */
1378 			size_t w = fwrite(base_buf, 1, base_bufsz,
1379 			    base_file);
1380 			if (w != base_bufsz) {
1381 				err = got_ferror(outfile, GOT_ERR_IO);
1382 				goto done;
1383 			}
1384 			free(base_buf);
1385 			base_buf = NULL;
1386 			free(accum_buf);
1387 			accum_buf = NULL;
1388 		}
1389 
1390 		if (base_buf && max_size > base_bufsz) {
1391 			uint8_t *p = realloc(base_buf, max_size);
1392 			if (p == NULL) {
1393 				err = got_error_from_errno("realloc");
1394 				goto done;
1395 			}
1396 			base_buf = p;
1397 			base_bufsz = max_size;
1398 		}
1399 
1400 		if (accum_buf && max_size > accum_bufsz) {
1401 			uint8_t *p = realloc(accum_buf, max_size);
1402 			if (p == NULL) {
1403 				err = got_error_from_errno("realloc");
1404 				goto done;
1405 			}
1406 			accum_buf = p;
1407 			accum_bufsz = max_size;
1408 		}
1409 
1410 		if (base_buf) {
1411 			err = got_delta_apply_in_mem(base_buf, base_bufsz,
1412 			    delta_buf, delta_len, accum_buf,
1413 			    &accum_size, max_size);
1414 			n++;
1415 		} else {
1416 			err = got_delta_apply(base_file, delta_buf,
1417 			    delta_len,
1418 			    /* Final delta application writes to output file. */
1419 			    ++n < deltas->nentries ? accum_file : outfile,
1420 			    &accum_size);
1421 		}
1422 		if (!cached)
1423 			free(delta_buf);
1424 		if (err)
1425 			goto done;
1426 
1427 		if (n < deltas->nentries) {
1428 			/* Accumulated delta becomes the new base. */
1429 			if (base_buf) {
1430 				uint8_t *tmp = accum_buf;
1431 				size_t tmp_size = accum_bufsz;
1432 				accum_buf = base_buf;
1433 				accum_bufsz = base_bufsz;
1434 				base_buf = tmp;
1435 				base_bufsz = tmp_size;
1436 			} else {
1437 				FILE *tmp = accum_file;
1438 				accum_file = base_file;
1439 				base_file = tmp;
1440 				rewind(base_file);
1441 				rewind(accum_file);
1442 			}
1443 		}
1444 	}
1445 
1446 done:
1447 	free(base_buf);
1448 	if (accum_buf) {
1449 		size_t len = fwrite(accum_buf, 1, accum_size, outfile);
1450 		free(accum_buf);
1451 		if (len != accum_size)
1452 			err = got_ferror(outfile, GOT_ERR_IO);
1453 	}
1454 	rewind(outfile);
1455 	if (err == NULL)
1456 		*result_size = accum_size;
1457 	return err;
1458 }
1459 
1460 const struct got_error *
1461 got_pack_dump_delta_chain_to_mem(uint8_t **outbuf, size_t *outlen,
1462     struct got_delta_chain *deltas, struct got_pack *pack)
1463 {
1464 	const struct got_error *err = NULL;
1465 	struct got_delta *delta;
1466 	uint8_t *base_buf = NULL, *accum_buf = NULL, *delta_buf;
1467 	size_t base_bufsz = 0, accum_bufsz = 0, accum_size = 0, delta_len;
1468 	uint64_t max_size = 0;
1469 	int n = 0;
1470 
1471 	*outbuf = NULL;
1472 	*outlen = 0;
1473 
1474 	if (STAILQ_EMPTY(&deltas->entries))
1475 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1476 
1477 	/* Deltas are ordered in ascending order. */
1478 	STAILQ_FOREACH(delta, &deltas->entries, entry) {
1479 		uint64_t base_size, result_size = 0;
1480 		int cached = 1;
1481 		if (n == 0) {
1482 			size_t delta_data_offset;
1483 
1484 			/* Plain object types are the delta base. */
1485 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1486 			    delta->type != GOT_OBJ_TYPE_TREE &&
1487 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1488 			    delta->type != GOT_OBJ_TYPE_TAG) {
1489 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1490 				goto done;
1491 			}
1492 
1493 			delta_data_offset = delta->offset + delta->tslen;
1494 			if (delta_data_offset >= pack->filesize) {
1495 				err = got_error(GOT_ERR_PACK_OFFSET);
1496 				goto done;
1497 			}
1498 
1499 			if (delta->size > max_size)
1500 				max_size = delta->size;
1501 
1502 			if (pack->map) {
1503 				size_t mapoff = (size_t)delta_data_offset;
1504 				err = got_inflate_to_mem_mmap(&base_buf,
1505 				    &base_bufsz, NULL, NULL, pack->map,
1506 				    mapoff, pack->filesize - mapoff);
1507 			} else {
1508 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1509 				    == -1) {
1510 					err = got_error_from_errno("lseek");
1511 					goto done;
1512 				}
1513 				err = got_inflate_to_mem_fd(&base_buf,
1514 				    &base_bufsz, NULL, NULL, max_size,
1515 				    pack->fd);
1516 			}
1517 			if (err)
1518 				goto done;
1519 			n++;
1520 			continue;
1521 		}
1522 
1523 		got_delta_cache_get(&delta_buf, &delta_len,
1524 		    pack->delta_cache, delta->data_offset);
1525 		if (delta_buf == NULL) {
1526 			cached = 0;
1527 			err = read_delta_data(&delta_buf, &delta_len, NULL,
1528 			    delta->data_offset, pack);
1529 			if (err)
1530 				goto done;
1531 			err = got_delta_cache_add(pack->delta_cache,
1532 			    delta->data_offset, delta_buf, delta_len);
1533 			if (err == NULL)
1534 				cached = 1;
1535 			else if (err->code != GOT_ERR_NO_SPACE) {
1536 				free(delta_buf);
1537 				goto done;
1538 			}
1539 		}
1540 
1541 		err = got_delta_get_sizes(&base_size, &result_size,
1542 		    delta_buf, delta_len);
1543 		if (err)
1544 			goto done;
1545 		if (base_size > max_size)
1546 			max_size = base_size;
1547 		if (result_size > max_size)
1548 			max_size = result_size;
1549 
1550 		if (max_size > base_bufsz) {
1551 			uint8_t *p = realloc(base_buf, max_size);
1552 			if (p == NULL) {
1553 				err = got_error_from_errno("realloc");
1554 				goto done;
1555 			}
1556 			base_buf = p;
1557 			base_bufsz = max_size;
1558 		}
1559 
1560 		if (max_size > accum_bufsz) {
1561 			uint8_t *p = realloc(accum_buf, max_size);
1562 			if (p == NULL) {
1563 				err = got_error_from_errno("realloc");
1564 				goto done;
1565 			}
1566 			accum_buf = p;
1567 			accum_bufsz = max_size;
1568 		}
1569 
1570 		err = got_delta_apply_in_mem(base_buf, base_bufsz,
1571 		    delta_buf, delta_len, accum_buf,
1572 		    &accum_size, max_size);
1573 		if (!cached)
1574 			free(delta_buf);
1575 		n++;
1576 		if (err)
1577 			goto done;
1578 
1579 		if (n < deltas->nentries) {
1580 			/* Accumulated delta becomes the new base. */
1581 			uint8_t *tmp = accum_buf;
1582 			size_t tmp_size = accum_bufsz;
1583 			accum_buf = base_buf;
1584 			accum_bufsz = base_bufsz;
1585 			base_buf = tmp;
1586 			base_bufsz = tmp_size;
1587 		}
1588 	}
1589 
1590 done:
1591 	free(base_buf);
1592 	if (err) {
1593 		free(accum_buf);
1594 		*outbuf = NULL;
1595 		*outlen = 0;
1596 	} else {
1597 		*outbuf = accum_buf;
1598 		*outlen = accum_size;
1599 	}
1600 	return err;
1601 }
1602 
1603 const struct got_error *
1604 got_packfile_extract_object(struct got_pack *pack, struct got_object *obj,
1605     FILE *outfile, FILE *base_file, FILE *accum_file)
1606 {
1607 	const struct got_error *err = NULL;
1608 
1609 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1610 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1611 
1612 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1613 		if (obj->pack_offset >= pack->filesize)
1614 			return got_error(GOT_ERR_PACK_OFFSET);
1615 
1616 		if (pack->map) {
1617 			size_t mapoff = (size_t)obj->pack_offset;
1618 			err = got_inflate_to_file_mmap(&obj->size, NULL, NULL,
1619 			    pack->map, mapoff, pack->filesize - mapoff,
1620 			    outfile);
1621 		} else {
1622 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1623 				return got_error_from_errno("lseek");
1624 			err = got_inflate_to_file_fd(&obj->size, NULL, NULL,
1625 			    pack->fd, outfile);
1626 		}
1627 	} else
1628 		err = got_pack_dump_delta_chain_to_file(&obj->size,
1629 		    &obj->deltas, pack, outfile, base_file, accum_file);
1630 
1631 	return err;
1632 }
1633 
1634 const struct got_error *
1635 got_packfile_extract_object_to_mem(uint8_t **buf, size_t *len,
1636     struct got_object *obj, struct got_pack *pack)
1637 {
1638 	const struct got_error *err = NULL;
1639 
1640 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1641 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1642 
1643 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1644 		if (obj->pack_offset >= pack->filesize)
1645 			return got_error(GOT_ERR_PACK_OFFSET);
1646 		if (pack->map) {
1647 			size_t mapoff = (size_t)obj->pack_offset;
1648 			err = got_inflate_to_mem_mmap(buf, len, NULL, NULL,
1649 			    pack->map, mapoff, pack->filesize - mapoff);
1650 		} else {
1651 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1652 				return got_error_from_errno("lseek");
1653 			err = got_inflate_to_mem_fd(buf, len, NULL, NULL,
1654 			    obj->size, pack->fd);
1655 		}
1656 	} else
1657 		err = got_pack_dump_delta_chain_to_mem(buf, len, &obj->deltas,
1658 		    pack);
1659 
1660 	return err;
1661 }
1662 
1663 static const struct got_error *
1664 read_raw_delta_data(uint8_t **delta_buf, size_t *delta_len,
1665     size_t *delta_len_compressed, uint64_t *base_size, uint64_t *result_size,
1666     off_t delta_data_offset, struct got_pack *pack, struct got_packidx *packidx)
1667 {
1668 	const struct got_error *err = NULL;
1669 
1670 	/* Validate decompression and obtain the decompressed size. */
1671 	err = read_delta_data(delta_buf, delta_len, delta_len_compressed,
1672 	    delta_data_offset, pack);
1673 	if (err)
1674 		return err;
1675 
1676 	/* Read delta base/result sizes from head of delta stream. */
1677 	err = got_delta_get_sizes(base_size, result_size,
1678 	    *delta_buf, *delta_len);
1679 	if (err)
1680 		goto done;
1681 
1682 	/* Discard decompressed delta and read it again in compressed form. */
1683 	free(*delta_buf);
1684 	*delta_buf = malloc(*delta_len_compressed);
1685 	if (*delta_buf == NULL) {
1686 		err = got_error_from_errno("malloc");
1687 		goto done;
1688 	}
1689 	if (pack->map) {
1690 		if (delta_data_offset >= pack->filesize)
1691 			err = got_error(GOT_ERR_PACK_OFFSET);
1692 		memcpy(*delta_buf, pack->map + delta_data_offset,
1693 		    *delta_len_compressed);
1694 	} else {
1695 		ssize_t n;
1696 		if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1) {
1697 			err = got_error_from_errno("lseek");
1698 			goto done;
1699 		}
1700 		n = read(pack->fd, *delta_buf, *delta_len_compressed);
1701 		if (n < 0) {
1702 			err = got_error_from_errno("read");
1703 			goto done;
1704 		} else if (n != *delta_len_compressed) {
1705 			err = got_error(GOT_ERR_IO);
1706 			goto done;
1707 		}
1708 	}
1709 done:
1710 	if (err) {
1711 		free(*delta_buf);
1712 		*delta_buf = NULL;
1713 		*delta_len = 0;
1714 		*delta_len_compressed = 0;
1715 		*base_size = 0;
1716 		*result_size = 0;
1717 	}
1718 	return err;
1719 }
1720 
1721 const struct got_error *
1722 got_packfile_extract_raw_delta(uint8_t **delta_buf, size_t *delta_size,
1723     size_t *delta_compressed_size, off_t *delta_offset, off_t *base_offset,
1724     struct got_object_id *base_id, uint64_t *base_size, uint64_t *result_size,
1725     struct got_pack *pack, struct got_packidx *packidx, int idx)
1726 {
1727 	const struct got_error *err = NULL;
1728 	off_t offset;
1729 	uint8_t type;
1730 	uint64_t size;
1731 	size_t tslen, delta_hdrlen;
1732 	off_t delta_data_offset;
1733 
1734 	*delta_buf = NULL;
1735 	*delta_size = 0;
1736 	*delta_compressed_size = 0;
1737 	*delta_offset = 0;
1738 	*base_offset = 0;
1739 	*base_size = 0;
1740 	*result_size = 0;
1741 
1742 	offset = got_packidx_get_object_offset(packidx, idx);
1743 	if (offset == (uint64_t)-1)
1744 		return got_error(GOT_ERR_BAD_PACKIDX);
1745 
1746 	if (offset >= pack->filesize)
1747 		return got_error(GOT_ERR_PACK_OFFSET);
1748 
1749 	err = got_pack_parse_object_type_and_size(&type, &size, &tslen,
1750 	    pack, offset);
1751 	if (err)
1752 		return err;
1753 
1754 	if (tslen + size < tslen || offset + size < size ||
1755 	    tslen + offset < tslen)
1756 		return got_error(GOT_ERR_PACK_OFFSET);
1757 
1758 	switch (type) {
1759 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1760 		err = got_pack_parse_offset_delta(base_offset, &delta_hdrlen,
1761 		    pack, offset, tslen);
1762 		if (err)
1763 			return err;
1764 		break;
1765 	case GOT_OBJ_TYPE_REF_DELTA:
1766 		err = got_pack_parse_ref_delta(base_id, pack, offset, tslen);
1767 		if (err)
1768 			return err;
1769 		delta_hdrlen = SHA1_DIGEST_LENGTH;
1770 		break;
1771 	default:
1772 		return got_error_fmt(GOT_ERR_OBJ_TYPE,
1773 		    "non-delta object type %d found at offset %llu",
1774 		    type, offset);
1775 	}
1776 
1777 	if (tslen + delta_hdrlen < delta_hdrlen ||
1778 	    offset + delta_hdrlen < delta_hdrlen)
1779 		return got_error(GOT_ERR_BAD_DELTA);
1780 
1781 	delta_data_offset = offset + tslen + delta_hdrlen;
1782 	err = read_raw_delta_data(delta_buf, delta_size, delta_compressed_size,
1783 	    base_size, result_size, delta_data_offset, pack, packidx);
1784 	if (err)
1785 		return err;
1786 
1787 	if (*delta_size != size) {
1788 		err = got_error(GOT_ERR_BAD_DELTA);
1789 		goto done;
1790 	}
1791 
1792 	*delta_offset = offset;
1793 done:
1794 	if (err) {
1795 		free(*delta_buf);
1796 		*delta_buf = NULL;
1797 		*delta_size = 0;
1798 		*delta_compressed_size = 0;
1799 		*delta_offset = 0;
1800 		*base_offset = 0;
1801 		*base_size = 0;
1802 		*result_size = 0;
1803 	}
1804 	return err;
1805 }