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Date:: Sun Sep 9 15:24:46 2018 UTC
Message:: make got_packfile_extract_object_to_mem() accept pack instead of repo
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1 /*
2  * Copyright (c) 2018 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/mman.h>
21 
22 #include <fcntl.h>
23 #include <errno.h>
24 #include <stdio.h>
25 #include <stdint.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <limits.h>
29 #include <sha1.h>
30 #include <endian.h>
31 #include <zlib.h>
32 
33 #include "got_error.h"
34 #include "got_object.h"
35 #include "got_repository.h"
36 #include "got_opentemp.h"
37 
38 #include "got_lib_sha1.h"
39 #include "got_lib_pack.h"
40 #include "got_lib_path.h"
41 #include "got_lib_delta.h"
42 #include "got_lib_inflate.h"
43 #include "got_lib_object.h"
44 #include "got_lib_repository.h"
45 
46 #ifndef nitems
47 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
48 #endif
49 
50 #ifndef MIN
51 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
52 #endif
53 
54 static const struct got_error *
55 verify_fanout_table(uint32_t *fanout_table)
56 {
57 	int i;
58 
59 	for (i = 0; i < 0xff - 1; i++) {
60 		if (be32toh(fanout_table[i]) > be32toh(fanout_table[i + 1]))
61 			return got_error(GOT_ERR_BAD_PACKIDX);
62 	}
63 
64 	return NULL;
65 }
66 
67 const struct got_error *
68 got_pack_get_packfile_size(size_t *size, const char *path)
69 {
70 	struct stat sb;
71 	char *dot;
72 
73 	*size = 0;
74 
75 	dot = strrchr(path, '.');
76 	if (dot == NULL)
77 		return got_error(GOT_ERR_BAD_PATH);
78 
79 	/* Path must point to a pack index or to a pack file. */
80 	if (strcmp(dot, GOT_PACKIDX_SUFFIX) == 0) {
81 		const struct got_error *err = NULL;
82 		char *path_pack;
83 		char base_path[PATH_MAX];
84 
85 		/* Convert pack index path to pack file path. */
86 		if (strlcpy(base_path, path, PATH_MAX) > PATH_MAX)
87 			return got_error(GOT_ERR_NO_SPACE);
88 		dot = strrchr(base_path, '.');
89 		if (dot == NULL)
90 			return got_error(GOT_ERR_BAD_PATH);
91 		*dot = '\0';
92 		if (asprintf(&path_pack, "%s.pack", base_path) == -1)
93 			return got_error_from_errno();
94 
95 		if (stat(path_pack, &sb) != 0)
96 			err = got_error_from_errno();
97 		free(path_pack);
98 		if (err)
99 			return err;
100 	} else if (strcmp(dot, GOT_PACKFILE_SUFFIX) == 0) {
101 		if (stat(path, &sb) != 0)
102 			return got_error_from_errno();
103 	} else
104 		return got_error(GOT_ERR_BAD_PATH);
105 
106 	*size = sb.st_size;
107 	return 0;
108 }
109 
110 const struct got_error *
111 got_packidx_init_hdr(struct got_packidx *p, int verify)
112 {
113 	const struct got_error *err = NULL;
114 	struct got_packidx_v2_hdr *h;
115 	SHA1_CTX ctx;
116 	uint8_t sha1[SHA1_DIGEST_LENGTH];
117 	size_t nobj, len_fanout, len_ids, offset, remain;
118 	ssize_t n;
119 
120 	SHA1Init(&ctx);
121 
122 	h = &p->hdr;
123 	offset = 0;
124 	remain = p->len;
125 
126 	if (remain < sizeof(*h->magic)) {
127 		err = got_error(GOT_ERR_BAD_PACKIDX);
128 		goto done;
129 	}
130 	if (p->map)
131 		h->magic = (uint32_t *)(p->map + offset);
132 	else {
133 		h->magic = malloc(sizeof(*h->magic));
134 		if (h->magic == NULL) {
135 			err = got_error_from_errno();
136 			goto done;
137 		}
138 		n = read(p->fd, h->magic, sizeof(*h->magic));
139 		if (n != sizeof(*h->magic)) {
140 			err = got_error(GOT_ERR_BAD_PACKIDX);
141 			goto done;
142 		}
143 	}
144 	if (betoh32(*h->magic) != GOT_PACKIDX_V2_MAGIC) {
145 		err = got_error(GOT_ERR_BAD_PACKIDX);
146 		goto done;
147 	}
148 	offset += sizeof(*h->magic);
149 	remain -= sizeof(*h->magic);
150 
151 	if (verify)
152 		SHA1Update(&ctx, (uint8_t *)h->magic, sizeof(*h->magic));
153 
154 	if (remain < sizeof(*h->version)) {
155 		err = got_error(GOT_ERR_BAD_PACKIDX);
156 		goto done;
157 	}
158 	if (p->map)
159 		h->version = (uint32_t *)(p->map + offset);
160 	else {
161 		h->version = malloc(sizeof(*h->version));
162 		if (h->version == NULL) {
163 			err = got_error_from_errno();
164 			goto done;
165 		}
166 		n = read(p->fd, h->version, sizeof(*h->version));
167 		if (n != sizeof(*h->version)) {
168 			err = got_error(GOT_ERR_BAD_PACKIDX);
169 			goto done;
170 		}
171 	}
172 	if (betoh32(*h->version) != GOT_PACKIDX_VERSION) {
173 		err = got_error(GOT_ERR_BAD_PACKIDX);
174 		goto done;
175 	}
176 	offset += sizeof(*h->version);
177 	remain -= sizeof(*h->version);
178 
179 	if (verify)
180 		SHA1Update(&ctx, (uint8_t *)h->version, sizeof(*h->version));
181 
182 	len_fanout =
183 	    sizeof(*h->fanout_table) * GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS;
184 	if (remain < len_fanout) {
185 		err = got_error(GOT_ERR_BAD_PACKIDX);
186 		goto done;
187 	}
188 	if (p->map)
189 		h->fanout_table = (uint32_t *)(p->map + offset);
190 	else {
191 		h->fanout_table = malloc(len_fanout);
192 		if (h->fanout_table == NULL) {
193 			err = got_error_from_errno();
194 			goto done;
195 		}
196 		n = read(p->fd, h->fanout_table, len_fanout);
197 		if (n != len_fanout) {
198 			err = got_error(GOT_ERR_BAD_PACKIDX);
199 			goto done;
200 		}
201 	}
202 	err = verify_fanout_table(h->fanout_table);
203 	if (err)
204 		goto done;
205 	if (verify)
206 		SHA1Update(&ctx, (uint8_t *)h->fanout_table, len_fanout);
207 	offset += len_fanout;
208 	remain -= len_fanout;
209 
210 	nobj = betoh32(h->fanout_table[0xff]);
211 	len_ids = nobj * sizeof(*h->sorted_ids);
212 	if (len_ids <= nobj || len_ids > remain) {
213 		err = got_error(GOT_ERR_BAD_PACKIDX);
214 		goto done;
215 	}
216 	if (p->map)
217 		h->sorted_ids =
218 		    (struct got_packidx_object_id *)((uint8_t*)(p->map + offset));
219 	else {
220 		h->sorted_ids = malloc(len_ids);
221 		if (h->sorted_ids == NULL) {
222 			err = got_error(GOT_ERR_BAD_PACKIDX);
223 			goto done;
224 		}
225 		n = read(p->fd, h->sorted_ids, len_ids);
226 		if (n != len_ids) {
227 			err = got_error(GOT_ERR_BAD_PACKIDX);
228 			goto done;
229 		}
230 	}
231 	if (verify)
232 		SHA1Update(&ctx, (uint8_t *)h->sorted_ids, len_ids);
233 	offset += len_ids;
234 	remain -= len_ids;
235 
236 	if (remain < nobj * sizeof(*h->crc32)) {
237 		err = got_error(GOT_ERR_BAD_PACKIDX);
238 		goto done;
239 	}
240 	if (p->map)
241 		h->crc32 = (uint32_t *)((uint8_t*)(p->map + offset));
242 	else {
243 		h->crc32 = malloc(nobj * sizeof(*h->crc32));
244 		if (h->crc32 == NULL) {
245 			err = got_error_from_errno();
246 			goto done;
247 		}
248 		n = read(p->fd, h->crc32, nobj * sizeof(*h->crc32));
249 		if (n != nobj * sizeof(*h->crc32)) {
250 			err = got_error(GOT_ERR_BAD_PACKIDX);
251 			goto done;
252 		}
253 	}
254 	if (verify)
255 		SHA1Update(&ctx, (uint8_t *)h->crc32, nobj * sizeof(*h->crc32));
256 	remain -= nobj * sizeof(*h->crc32);
257 	offset += nobj * sizeof(*h->crc32);
258 
259 	if (remain < nobj * sizeof(*h->offsets)) {
260 		err = got_error(GOT_ERR_BAD_PACKIDX);
261 		goto done;
262 	}
263 	if (p->map)
264 		h->offsets = (uint32_t *)((uint8_t*)(p->map + offset));
265 	else {
266 		h->offsets = malloc(nobj * sizeof(*h->offsets));
267 		if (h->offsets == NULL) {
268 			err = got_error_from_errno();
269 			goto done;
270 		}
271 		n = read(p->fd, h->offsets, nobj * sizeof(*h->offsets));
272 		if (n != nobj * sizeof(*h->offsets)) {
273 			err = got_error(GOT_ERR_BAD_PACKIDX);
274 			goto done;
275 		}
276 	}
277 	if (verify)
278 		SHA1Update(&ctx, (uint8_t *)h->offsets,
279 		    nobj * sizeof(*h->offsets));
280 	remain -= nobj * sizeof(*h->offsets);
281 	offset += nobj * sizeof(*h->offsets);
282 
283 	/* Large file offsets are contained only in files > 2GB. */
284 	if (p->len <= 0x80000000)
285 		goto checksum;
286 
287 	if (remain < nobj * sizeof(*h->large_offsets)) {
288 		err = got_error(GOT_ERR_BAD_PACKIDX);
289 		goto done;
290 	}
291 	if (p->map)
292 		h->large_offsets = (uint64_t *)((uint8_t*)(p->map + offset));
293 	else {
294 		h->offsets = malloc(nobj * sizeof(*h->large_offsets));
295 		if (h->offsets == NULL) {
296 			err = got_error_from_errno();
297 			goto done;
298 		}
299 		n = read(p->fd, h->large_offsets,
300 		    nobj * sizeof(*h->large_offsets));
301 		if (n != nobj * sizeof(*h->large_offsets)) {
302 			err = got_error(GOT_ERR_BAD_PACKIDX);
303 			goto done;
304 		}
305 	}
306 	if (verify)
307 		SHA1Update(&ctx, (uint8_t*)h->large_offsets,
308 		    nobj * sizeof(*h->large_offsets));
309 	remain -= nobj * sizeof(*h->large_offsets);
310 	offset += nobj * sizeof(*h->large_offsets);
311 
312 checksum:
313 	if (remain < sizeof(*h->trailer)) {
314 		err = got_error(GOT_ERR_BAD_PACKIDX);
315 		goto done;
316 	}
317 	if (p->map)
318 		h->trailer =
319 		    (struct got_packidx_trailer *)((uint8_t*)(p->map + offset));
320 	else {
321 		h->trailer = malloc(sizeof(*h->trailer));
322 		if (h->trailer == NULL) {
323 			err = got_error_from_errno();
324 			goto done;
325 		}
326 		n = read(p->fd, h->trailer, sizeof(*h->trailer));
327 		if (n != sizeof(*h->trailer)) {
328 			err = got_error(GOT_ERR_BAD_PACKIDX);
329 			goto done;
330 		}
331 	}
332 	if (verify) {
333 		SHA1Update(&ctx, h->trailer->packfile_sha1, SHA1_DIGEST_LENGTH);
334 		SHA1Final(sha1, &ctx);
335 		if (memcmp(h->trailer->packidx_sha1, sha1,
336 		    SHA1_DIGEST_LENGTH) != 0)
337 			err = got_error(GOT_ERR_PACKIDX_CSUM);
338 	}
339 done:
340 	return err;
341 }
342 
343 const struct got_error *
344 got_packidx_open(struct got_packidx **packidx, const char *path, int verify)
345 {
346 	const struct got_error *err = NULL;
347 	struct got_packidx *p;
348 
349 	*packidx = NULL;
350 
351 	p = calloc(1, sizeof(*p));
352 	if (p == NULL)
353 		return got_error_from_errno();
354 
355 	p->fd = open(path, O_RDONLY | O_NOFOLLOW, GOT_DEFAULT_FILE_MODE);
356 	if (p->fd == -1)
357 		return got_error_from_errno();
358 
359 	err = got_pack_get_packfile_size(&p->len, path);
360 	if (err) {
361 		close(p->fd);
362 		free(p);
363 		return err;
364 	}
365 	if (p->len < sizeof(p->hdr)) {
366 		err = got_error(GOT_ERR_BAD_PACKIDX);
367 		close(p->fd);
368 		free(p);
369 		return err;
370 	}
371 
372 	p->path_packidx = strdup(path);
373 	if (p->path_packidx == NULL) {
374 		err = got_error_from_errno();
375 		goto done;
376 	}
377 
378 #ifndef GOT_PACK_NO_MMAP
379 	p->map = mmap(NULL, p->len, PROT_READ, MAP_PRIVATE, p->fd, 0);
380 	if (p->map == MAP_FAILED)
381 		p->map = NULL; /* fall back to read(2) */
382 #endif
383 
384 	err = got_packidx_init_hdr(p, verify);
385 done:
386 	if (err)
387 		got_packidx_close(p);
388 	else
389 		*packidx = p;
390 
391 	return err;
392 }
393 
394 const struct got_error *
395 got_packidx_close(struct got_packidx *packidx)
396 {
397 	const struct got_error *err = NULL;
398 
399 	free(packidx->path_packidx);
400 	if (packidx->map) {
401 		if (munmap(packidx->map, packidx->len) == -1)
402 			err = got_error_from_errno();
403 	} else {
404 		free(packidx->hdr.magic);
405 		free(packidx->hdr.version);
406 		free(packidx->hdr.fanout_table);
407 		free(packidx->hdr.sorted_ids);
408 		free(packidx->hdr.crc32);
409 		free(packidx->hdr.offsets);
410 		free(packidx->hdr.large_offsets);
411 		free(packidx->hdr.trailer);
412 	}
413 	close(packidx->fd);
414 	free(packidx);
415 
416 	return err;
417 }
418 
419 static off_t
420 get_object_offset(struct got_packidx *packidx, int idx)
421 {
422 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
423 	uint32_t offset = betoh32(packidx->hdr.offsets[idx]);
424 	if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
425 		uint64_t loffset;
426 		idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
427 		if (idx < 0 || idx > totobj ||
428 		    packidx->hdr.large_offsets == NULL)
429 			return -1;
430 		loffset = betoh64(packidx->hdr.large_offsets[idx]);
431 		return (loffset > INT64_MAX ? -1 : (off_t)loffset);
432 	}
433 	return (off_t)(offset & GOT_PACKIDX_OFFSET_VAL_MASK);
434 }
435 
436 int
437 got_packidx_get_object_idx(struct got_packidx *packidx, struct got_object_id *id)
438 {
439 	u_int8_t id0 = id->sha1[0];
440 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
441 	int left = 0, right = totobj - 1;
442 
443 	if (id0 > 0)
444 		left = betoh32(packidx->hdr.fanout_table[id0 - 1]);
445 
446 	while (left <= right) {
447 		struct got_packidx_object_id *oid;
448 		int i, cmp;
449 
450 		i = ((left + right) / 2);
451 		oid = &packidx->hdr.sorted_ids[i];
452 		cmp = memcmp(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
453 		if (cmp == 0)
454 			return i;
455 		else if (cmp > 0)
456 			left = i + 1;
457 		else if (cmp < 0)
458 			right = i - 1;
459 	}
460 
461 	return -1;
462 }
463 
464 const struct got_error *
465 got_pack_close(struct got_pack *pack)
466 {
467 	const struct got_error *err = NULL;
468 
469 	if (pack->map && munmap(pack->map, pack->filesize) == -1)
470 		err = got_error_from_errno();
471 	close(pack->fd);
472 	pack->fd = -1;
473 	free(pack->path_packfile);
474 	pack->path_packfile = NULL;
475 	pack->filesize = 0;
476 
477 	return err;
478 }
479 
480 static const struct got_error *
481 parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len,
482     struct got_pack *pack, off_t offset)
483 {
484 	uint8_t t = 0;
485 	uint64_t s = 0;
486 	uint8_t sizeN;
487 	size_t mapoff = 0;
488 	int i = 0;
489 
490 	*len = 0;
491 
492 	if (offset >= pack->filesize)
493 		return got_error(GOT_ERR_PACK_OFFSET);
494 
495 	if (pack->map) {
496 		mapoff = (size_t)offset;
497 	} else {
498 		if (lseek(pack->fd, offset, SEEK_SET) == -1)
499 			return got_error_from_errno();
500 	}
501 
502 	do {
503 		/* We do not support size values which don't fit in 64 bit. */
504 		if (i > 9)
505 			return got_error(GOT_ERR_NO_SPACE);
506 
507 		if (pack->map) {
508 			sizeN = *(pack->map + mapoff);
509 			mapoff += sizeof(sizeN);
510 		} else {
511 			ssize_t n = read(pack->fd, &sizeN, sizeof(sizeN));
512 			if (n < 0)
513 				return got_error_from_errno();
514 			if (n != sizeof(sizeN))
515 				return got_error(GOT_ERR_BAD_PACKFILE);
516 		}
517 		*len += sizeof(sizeN);
518 
519 		if (i == 0) {
520 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
521 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
522 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
523 		} else {
524 			size_t shift = 4 + 7 * (i - 1);
525 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
526 		}
527 		i++;
528 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
529 
530 	*type = t;
531 	*size = s;
532 	return NULL;
533 }
534 
535 static const struct got_error *
536 open_plain_object(struct got_object **obj, const char *path_packfile,
537     struct got_object_id *id, uint8_t type, off_t offset, size_t size)
538 {
539 	*obj = calloc(1, sizeof(**obj));
540 	if (*obj == NULL)
541 		return got_error_from_errno();
542 
543 	(*obj)->path_packfile = strdup(path_packfile);
544 	if ((*obj)->path_packfile == NULL) {
545 		const struct got_error *err = got_error_from_errno();
546 		free(*obj);
547 		*obj = NULL;
548 		return err;
549 	}
550 
551 	(*obj)->type = type;
552 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
553 	(*obj)->hdrlen = 0;
554 	(*obj)->size = size;
555 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
556 	(*obj)->pack_offset = offset;
557 
558 	return NULL;
559 }
560 
561 static const struct got_error *
562 parse_negative_offset(int64_t *offset, size_t *len, struct got_pack *pack,
563     off_t delta_offset)
564 {
565 	int64_t o = 0;
566 	uint8_t offN;
567 	int i = 0;
568 
569 	*len = 0;
570 
571 	do {
572 		/* We do not support offset values which don't fit in 64 bit. */
573 		if (i > 8)
574 			return got_error(GOT_ERR_NO_SPACE);
575 
576 		if (pack->map) {
577 			size_t mapoff;
578 			if (delta_offset >= pack->filesize)
579 				return got_error(GOT_ERR_PACK_OFFSET);
580 			mapoff = (size_t)delta_offset + *len;
581 			offN = *(pack->map + mapoff);
582 		} else {
583 			ssize_t n;
584 			n = read(pack->fd, &offN, sizeof(offN));
585 			if (n < 0)
586 				return got_error_from_errno();
587 			if (n != sizeof(offN))
588 				return got_error(GOT_ERR_BAD_PACKFILE);
589 		}
590 		*len += sizeof(offN);
591 
592 		if (i == 0)
593 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
594 		else {
595 			o++;
596 			o <<= 7;
597 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
598 		}
599 		i++;
600 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
601 
602 	*offset = o;
603 	return NULL;
604 }
605 
606 static const struct got_error *
607 parse_offset_delta(off_t *base_offset, size_t *len, struct got_pack *pack,
608     off_t offset, int tslen)
609 {
610 	const struct got_error *err;
611 	int64_t negoffset;
612 	size_t negofflen;
613 
614 	*len = 0;
615 
616 	err = parse_negative_offset(&negoffset, &negofflen, pack,
617 	    offset + tslen);
618 	if (err)
619 		return err;
620 
621 	/* Compute the base object's offset (must be in the same pack file). */
622 	*base_offset = (offset - negoffset);
623 	if (*base_offset <= 0)
624 		return got_error(GOT_ERR_BAD_PACKFILE);
625 
626 	*len = negofflen;
627 	return NULL;
628 }
629 
630 static const struct got_error *
631 resolve_delta_chain(struct got_delta_chain *, struct got_packidx *,
632     struct got_pack *, off_t, size_t, int, size_t, unsigned int);
633 
634 static const struct got_error *
635 add_delta(struct got_delta_chain *deltas, off_t delta_offset, size_t tslen,
636     int delta_type, size_t delta_size, size_t delta_data_offset,
637     uint8_t *delta_buf, size_t delta_len)
638 {
639 	struct got_delta *delta;
640 
641 	delta = got_delta_open(delta_offset, tslen, delta_type, delta_size,
642 	    delta_data_offset, delta_buf,
643 	    delta_len);
644 	if (delta == NULL)
645 		return got_error_from_errno();
646 	/* delta is freed in got_object_close() */
647 	deltas->nentries++;
648 	SIMPLEQ_INSERT_HEAD(&deltas->entries, delta, entry);
649 	return NULL;
650 }
651 
652 static const struct got_error *
653 resolve_offset_delta(struct got_delta_chain *deltas,
654     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
655     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
656 
657 {
658 	const struct got_error *err;
659 	off_t base_offset;
660 	uint8_t base_type;
661 	uint64_t base_size;
662 	size_t base_tslen;
663 	off_t delta_data_offset;
664 	uint8_t *delta_buf;
665 	size_t delta_len, consumed;
666 
667 	err = parse_offset_delta(&base_offset, &consumed, pack,
668 	    delta_offset, tslen);
669 	if (err)
670 		return err;
671 
672 	delta_data_offset = delta_offset + tslen + consumed;
673 	if (delta_data_offset >= pack->filesize)
674 		return got_error(GOT_ERR_PACK_OFFSET);
675 
676 	if (pack->map == NULL) {
677 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
678 		if (delta_data_offset == -1)
679 			return got_error_from_errno();
680 	}
681 
682 	if (pack->map) {
683 		size_t mapoff = (size_t)delta_data_offset;
684 		err = got_inflate_to_mem_mmap(&delta_buf, &delta_len, pack->map,
685 		    mapoff, pack->filesize - mapoff);
686 		if (err)
687 			return err;
688 	} else {
689 
690 		err = got_inflate_to_mem_fd(&delta_buf, &delta_len, pack->fd);
691 		if (err)
692 			return err;
693 	}
694 
695 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
696 	    delta_data_offset, delta_buf, delta_len);
697 	if (err)
698 		goto done;
699 
700 	/* An offset delta must be in the same packfile. */
701 	if (base_offset >= pack->filesize) {
702 		err = got_error(GOT_ERR_PACK_OFFSET);
703 		goto done;
704 	}
705 
706 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
707 	    pack, base_offset);
708 	if (err)
709 		goto done;
710 
711 	err = resolve_delta_chain(deltas, packidx, pack, base_offset,
712 	    base_tslen, base_type, base_size, recursion - 1);
713 done:
714 	if (err)
715 		free(delta_buf);
716 	return err;
717 }
718 
719 static const struct got_error *
720 resolve_ref_delta(struct got_delta_chain *deltas, struct got_packidx *packidx,
721     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
722     size_t delta_size, unsigned int recursion)
723 {
724 	const struct got_error *err;
725 	struct got_object_id id;
726 	int idx;
727 	off_t base_offset;
728 	uint8_t base_type;
729 	uint64_t base_size;
730 	size_t base_tslen;
731 	off_t delta_data_offset;
732 	uint8_t *delta_buf = NULL;
733 	size_t delta_len;
734 
735 	if (delta_offset >= pack->filesize)
736 		return got_error(GOT_ERR_PACK_OFFSET);
737 	delta_data_offset = delta_offset + tslen;
738 	if (delta_data_offset >= pack->filesize)
739 		return got_error(GOT_ERR_PACK_OFFSET);
740 
741 	if (pack->map == NULL) {
742 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
743 		if (delta_data_offset == -1)
744 			return got_error_from_errno();
745 	}
746 
747 
748 	if (pack->map) {
749 		size_t mapoff = (size_t)delta_data_offset;
750 		memcpy(&id, pack->map + mapoff, sizeof(id));
751 		mapoff += sizeof(id);
752 		err = got_inflate_to_mem_mmap(&delta_buf, &delta_len, pack->map,
753 		    mapoff, pack->filesize - mapoff);
754 		if (err)
755 			goto done;
756 	} else {
757 		ssize_t n = read(pack->fd, &id, sizeof(id));
758 		if (n < 0)
759 			return got_error_from_errno();
760 		if (n != sizeof(id))
761 			return got_error(GOT_ERR_BAD_PACKFILE);
762 		err = got_inflate_to_mem_fd(&delta_buf, &delta_len, pack->fd);
763 		if (err)
764 			goto done;
765 	}
766 
767 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
768 	    delta_data_offset, delta_buf, delta_len);
769 	if (err)
770 		goto done;
771 
772 	/* Delta base must be in the same pack file. */
773 	idx = got_packidx_get_object_idx(packidx, &id);
774 	if (idx == -1) {
775 		err = got_error(GOT_ERR_BAD_PACKFILE);
776 		goto done;
777 	}
778 
779 	base_offset = get_object_offset(packidx, idx);
780 	if (base_offset == (uint64_t)-1) {
781 		err = got_error(GOT_ERR_BAD_PACKIDX);
782 		goto done;
783 	}
784 
785 	if (base_offset >= pack->filesize) {
786 		err = got_error(GOT_ERR_PACK_OFFSET);
787 		goto done;
788 	}
789 
790 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
791 	    pack, base_offset);
792 	if (err)
793 		goto done;
794 
795 	err = resolve_delta_chain(deltas, packidx, pack, base_offset,
796 	    base_tslen, base_type, base_size, recursion - 1);
797 done:
798 	if (err)
799 		free(delta_buf);
800 	return err;
801 }
802 
803 static const struct got_error *
804 resolve_delta_chain(struct got_delta_chain *deltas, struct got_packidx *packidx,
805     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
806     size_t delta_size, unsigned int recursion)
807 {
808 	const struct got_error *err = NULL;
809 
810 	if (--recursion == 0)
811 		return got_error(GOT_ERR_RECURSION);
812 
813 	switch (delta_type) {
814 	case GOT_OBJ_TYPE_COMMIT:
815 	case GOT_OBJ_TYPE_TREE:
816 	case GOT_OBJ_TYPE_BLOB:
817 	case GOT_OBJ_TYPE_TAG:
818 		/* Plain types are the final delta base. Recursion ends. */
819 		err = add_delta(deltas, delta_offset, tslen, delta_type,
820 		    delta_size, 0, NULL, 0);
821 		break;
822 	case GOT_OBJ_TYPE_OFFSET_DELTA:
823 		err = resolve_offset_delta(deltas, packidx, pack,
824 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
825 		break;
826 	case GOT_OBJ_TYPE_REF_DELTA:
827 		err = resolve_ref_delta(deltas, packidx, pack,
828 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
829 		break;
830 	default:
831 		return got_error(GOT_ERR_OBJ_TYPE);
832 	}
833 
834 	return err;
835 }
836 
837 static const struct got_error *
838 open_delta_object(struct got_object **obj, struct got_packidx *packidx,
839     struct got_pack *pack, struct got_object_id *id, off_t offset,
840     size_t tslen, int delta_type, size_t delta_size)
841 {
842 	const struct got_error *err = NULL;
843 	int resolved_type;
844 
845 	*obj = calloc(1, sizeof(**obj));
846 	if (*obj == NULL)
847 		return got_error_from_errno();
848 
849 	(*obj)->flags = 0;
850 	(*obj)->hdrlen = 0;
851 	(*obj)->size = 0; /* Not known because deltas aren't applied yet. */
852 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
853 	(*obj)->pack_offset = offset + tslen;
854 
855 	(*obj)->path_packfile = strdup(pack->path_packfile);
856 	if ((*obj)->path_packfile == NULL) {
857 		err = got_error_from_errno();
858 		goto done;
859 	}
860 	(*obj)->flags |= GOT_OBJ_FLAG_PACKED;
861 
862 	SIMPLEQ_INIT(&(*obj)->deltas.entries);
863 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
864 
865 	err = resolve_delta_chain(&(*obj)->deltas, packidx, pack, offset,
866 	    tslen, delta_type, delta_size, GOT_DELTA_CHAIN_RECURSION_MAX);
867 	if (err)
868 		goto done;
869 
870 	err = got_delta_chain_get_base_type(&resolved_type, &(*obj)->deltas);
871 	if (err)
872 		goto done;
873 	(*obj)->type = resolved_type;
874 
875 done:
876 	if (err) {
877 		got_object_close(*obj);
878 		*obj = NULL;
879 	}
880 	return err;
881 }
882 
883 const struct got_error *
884 got_packfile_open_object(struct got_object **obj, struct got_pack *pack,
885     struct got_packidx *packidx, int idx, struct got_object_id *id)
886 {
887 	const struct got_error *err = NULL;
888 	off_t offset;
889 	uint8_t type;
890 	uint64_t size;
891 	size_t tslen;
892 
893 	*obj = NULL;
894 
895 	offset = get_object_offset(packidx, idx);
896 	if (offset == (uint64_t)-1)
897 		return got_error(GOT_ERR_BAD_PACKIDX);
898 
899 	err = parse_object_type_and_size(&type, &size, &tslen, pack, offset);
900 	if (err)
901 		return err;
902 
903 	switch (type) {
904 	case GOT_OBJ_TYPE_COMMIT:
905 	case GOT_OBJ_TYPE_TREE:
906 	case GOT_OBJ_TYPE_BLOB:
907 	case GOT_OBJ_TYPE_TAG:
908 		err = open_plain_object(obj, pack->path_packfile, id, type,
909 		    offset + tslen, size);
910 		break;
911 	case GOT_OBJ_TYPE_OFFSET_DELTA:
912 	case GOT_OBJ_TYPE_REF_DELTA:
913 		err = open_delta_object(obj, packidx, pack, id, offset,
914 		    tslen, type, size);
915 		break;
916 	default:
917 		err = got_error(GOT_ERR_OBJ_TYPE);
918 		break;
919 	}
920 
921 	return err;
922 }
923 
924 static const struct got_error *
925 get_delta_chain_max_size(uint64_t *max_size, struct got_delta_chain *deltas)
926 {
927 	struct got_delta *delta;
928 	uint64_t base_size = 0, result_size = 0;
929 
930 	*max_size = 0;
931 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
932 		/* Plain object types are the delta base. */
933 		if (delta->type != GOT_OBJ_TYPE_COMMIT &&
934 		    delta->type != GOT_OBJ_TYPE_TREE &&
935 		    delta->type != GOT_OBJ_TYPE_BLOB &&
936 		    delta->type != GOT_OBJ_TYPE_TAG) {
937 			const struct got_error *err;
938 			err = got_delta_get_sizes(&base_size, &result_size,
939 			    delta->delta_buf, delta->delta_len);
940 			if (err)
941 				return err;
942 		} else
943 			base_size = delta->size;
944 		if (base_size > *max_size)
945 			*max_size = base_size;
946 		if (result_size > *max_size)
947 			*max_size = result_size;
948 	}
949 
950 	return NULL;
951 }
952 
953 static const struct got_error *
954 dump_delta_chain_to_file(size_t *result_size, struct got_delta_chain *deltas,
955     struct got_pack *pack, FILE *outfile)
956 {
957 	const struct got_error *err = NULL;
958 	struct got_delta *delta;
959 	FILE *base_file = NULL, *accum_file = NULL;
960 	uint8_t *base_buf = NULL, *accum_buf = NULL;
961 	size_t accum_size = 0;
962 	uint64_t max_size;
963 	int n = 0;
964 
965 	*result_size = 0;
966 
967 	if (SIMPLEQ_EMPTY(&deltas->entries))
968 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
969 
970 	/* We process small enough files entirely in memory for speed. */
971 	err = get_delta_chain_max_size(&max_size, deltas);
972 	if (err)
973 		return err;
974 	if (max_size < GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
975 		accum_buf = malloc(max_size);
976 		if (accum_buf == NULL)
977 			return got_error_from_errno();
978 	} else {
979 		base_file = got_opentemp();
980 		if (base_file == NULL)
981 			return got_error_from_errno();
982 
983 		accum_file = got_opentemp();
984 		if (accum_file == NULL) {
985 			err = got_error_from_errno();
986 			fclose(base_file);
987 			return err;
988 		}
989 	}
990 
991 	/* Deltas are ordered in ascending order. */
992 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
993 		if (n == 0) {
994 			size_t base_len, mapoff;
995 			off_t delta_data_offset;
996 
997 			/* Plain object types are the delta base. */
998 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
999 			    delta->type != GOT_OBJ_TYPE_TREE &&
1000 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1001 			    delta->type != GOT_OBJ_TYPE_TAG) {
1002 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1003 				goto done;
1004 			}
1005 
1006 			delta_data_offset = delta->offset + delta->tslen;
1007 			if (delta_data_offset >= pack->filesize) {
1008 				err = got_error(GOT_ERR_PACK_OFFSET);
1009 				goto done;
1010 			}
1011 			if (pack->map == NULL) {
1012 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1013 				    == -1) {
1014 					err = got_error_from_errno();
1015 					goto done;
1016 				}
1017 			}
1018 			if (base_file) {
1019 				if (pack->map) {
1020 					mapoff = (size_t)delta_data_offset;
1021 					err = got_inflate_to_file_mmap(
1022 					    &base_len, pack->map, mapoff,
1023 					    pack->filesize - mapoff, base_file);
1024 				} else
1025 					err = got_inflate_to_file_fd(&base_len,
1026 					    pack->fd, base_file);
1027 			} else {
1028 				if (pack->map) {
1029 					mapoff = (size_t)delta_data_offset;
1030 					err = got_inflate_to_mem_mmap(&base_buf,
1031 					    &base_len, pack->map, mapoff,
1032 					    pack->filesize - mapoff);
1033 				} else
1034 					err = got_inflate_to_mem_fd(&base_buf,
1035 					    &base_len, pack->fd);
1036 				if (base_len < max_size) {
1037 					uint8_t *p;
1038 					p = reallocarray(base_buf, 1, max_size);
1039 					if (p == NULL) {
1040 						err = got_error_from_errno();
1041 						goto done;
1042 					}
1043 					base_buf = p;
1044 				}
1045 			}
1046 			if (err)
1047 				goto done;
1048 			n++;
1049 			if (base_file)
1050 				rewind(base_file);
1051 			continue;
1052 		}
1053 
1054 		if (base_buf) {
1055 			err = got_delta_apply_in_mem(base_buf, delta->delta_buf,
1056 			    delta->delta_len, accum_buf, &accum_size);
1057 			n++;
1058 		} else {
1059 			err = got_delta_apply(base_file, delta->delta_buf,
1060 			    delta->delta_len,
1061 			    /* Final delta application writes to output file. */
1062 			    ++n < deltas->nentries ? accum_file : outfile,
1063 			    &accum_size);
1064 		}
1065 		if (err)
1066 			goto done;
1067 
1068 		if (n < deltas->nentries) {
1069 			/* Accumulated delta becomes the new base. */
1070 			if (base_buf) {
1071 				uint8_t *tmp = accum_buf;
1072 				accum_buf = base_buf;
1073 				base_buf = tmp;
1074 			} else {
1075 				FILE *tmp = accum_file;
1076 				accum_file = base_file;
1077 				base_file = tmp;
1078 				rewind(base_file);
1079 				rewind(accum_file);
1080 			}
1081 		}
1082 	}
1083 
1084 done:
1085 	free(base_buf);
1086 	if (accum_buf) {
1087 		size_t len = fwrite(accum_buf, 1, accum_size, outfile);
1088 		free(accum_buf);
1089 		if (len != accum_size)
1090 			err = got_ferror(outfile, GOT_ERR_IO);
1091 	}
1092 	if (base_file)
1093 		fclose(base_file);
1094 	if (accum_file)
1095 		fclose(accum_file);
1096 	rewind(outfile);
1097 	if (err == NULL)
1098 		*result_size = accum_size;
1099 	return err;
1100 }
1101 
1102 static const struct got_error *
1103 dump_delta_chain_to_mem(uint8_t **outbuf, size_t *outlen,
1104     struct got_delta_chain *deltas, struct got_pack *pack)
1105 {
1106 	const struct got_error *err = NULL;
1107 	struct got_delta *delta;
1108 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1109 	size_t accum_size;
1110 	uint64_t max_size;
1111 	int n = 0;
1112 
1113 	*outbuf = NULL;
1114 	*outlen = 0;
1115 
1116 	if (SIMPLEQ_EMPTY(&deltas->entries))
1117 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1118 
1119 	err = get_delta_chain_max_size(&max_size, deltas);
1120 	if (err)
1121 		return err;
1122 	accum_buf = malloc(max_size);
1123 	if (accum_buf == NULL)
1124 		return got_error_from_errno();
1125 
1126 	/* Deltas are ordered in ascending order. */
1127 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1128 		if (n == 0) {
1129 			size_t base_len;
1130 			size_t delta_data_offset;
1131 
1132 			/* Plain object types are the delta base. */
1133 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1134 			    delta->type != GOT_OBJ_TYPE_TREE &&
1135 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1136 			    delta->type != GOT_OBJ_TYPE_TAG) {
1137 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1138 				goto done;
1139 			}
1140 
1141 			delta_data_offset = delta->offset + delta->tslen;
1142 			if (delta_data_offset >= pack->filesize) {
1143 				err = got_error(GOT_ERR_PACK_OFFSET);
1144 				goto done;
1145 			}
1146 			if (pack->map) {
1147 				size_t mapoff = (size_t)delta_data_offset;
1148 				err = got_inflate_to_mem_mmap(&base_buf,
1149 				    &base_len, pack->map, mapoff,
1150 				    pack->filesize - mapoff);
1151 			} else {
1152 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1153 				    == -1) {
1154 					err = got_error_from_errno();
1155 					goto done;
1156 				}
1157 				err = got_inflate_to_mem_fd(&base_buf,
1158 				    &base_len, pack->fd);
1159 			}
1160 			if (err)
1161 				goto done;
1162 			if (base_len < max_size) {
1163 				uint8_t *p;
1164 				p = reallocarray(base_buf, 1, max_size);
1165 				if (p == NULL) {
1166 					err = got_error_from_errno();
1167 					goto done;
1168 				}
1169 				base_buf = p;
1170 			}
1171 			n++;
1172 			continue;
1173 		}
1174 
1175 		err = got_delta_apply_in_mem(base_buf, delta->delta_buf,
1176 		    delta->delta_len, accum_buf, &accum_size);
1177 		n++;
1178 		if (err)
1179 			goto done;
1180 
1181 		if (n < deltas->nentries) {
1182 			/* Accumulated delta becomes the new base. */
1183 			uint8_t *tmp = accum_buf;
1184 			accum_buf = base_buf;
1185 			base_buf = tmp;
1186 		}
1187 	}
1188 
1189 done:
1190 	free(base_buf);
1191 	if (err) {
1192 		free(accum_buf);
1193 		*outbuf = NULL;
1194 		*outlen = 0;
1195 	} else {
1196 		*outbuf = accum_buf;
1197 		*outlen = accum_size;
1198 	}
1199 	return err;
1200 }
1201 
1202 const struct got_error *
1203 got_packfile_extract_object(struct got_pack *pack, struct got_object *obj,
1204     FILE *outfile)
1205 {
1206 	const struct got_error *err = NULL;
1207 
1208 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1209 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1210 
1211 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1212 		if (obj->pack_offset >= pack->filesize)
1213 			return got_error(GOT_ERR_PACK_OFFSET);
1214 
1215 		if (pack->map) {
1216 			size_t mapoff = (size_t)obj->pack_offset;
1217 			err = got_inflate_to_file_mmap(&obj->size, pack->map,
1218 			    mapoff, pack->filesize - mapoff, outfile);
1219 		} else {
1220 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1221 				return got_error_from_errno();
1222 			err = got_inflate_to_file_fd(&obj->size, pack->fd,
1223 			    outfile);
1224 		}
1225 	} else
1226 		err = dump_delta_chain_to_file(&obj->size, &obj->deltas, pack,
1227 		    outfile);
1228 
1229 	return err;
1230 }
1231 
1232 const struct got_error *
1233 got_packfile_extract_object_to_mem(uint8_t **buf, size_t *len,
1234     struct got_object *obj, struct got_pack *pack)
1235 {
1236 	const struct got_error *err = NULL;
1237 
1238 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1239 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1240 
1241 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1242 		if (obj->pack_offset >= pack->filesize)
1243 			return got_error(GOT_ERR_PACK_OFFSET);
1244 		if (pack->map) {
1245 			size_t mapoff = (size_t)obj->pack_offset;
1246 			err = got_inflate_to_mem_mmap(buf, len, pack->map,
1247 			    mapoff, pack->filesize - mapoff);
1248 		} else {
1249 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1250 				return got_error_from_errno();
1251 			err = got_inflate_to_mem_fd(buf, len, pack->fd);
1252 		}
1253 	} else
1254 		err = dump_delta_chain_to_mem(buf, len, &obj->deltas, pack);
1255 
1256 	return err;
1257 }