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Date:: Thu Feb 21 13:15:33 2019 UTC
Message:: more specific mmap(2) failure checks
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1 /*
2  * Copyright (c) 2018, 2019 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 <zlib.h>
33 #include <imsg.h>
34 
35 #include "got_error.h"
36 #include "got_object.h"
37 #include "got_opentemp.h"
38 
39 #include "got_lib_sha1.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_privsep.h"
45 #include "got_lib_pack.h"
46 
47 #ifndef nitems
48 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
49 #endif
50 
51 #ifndef MIN
52 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
53 #endif
54 
55 static const struct got_error *
56 verify_fanout_table(uint32_t *fanout_table)
57 {
58 	int i;
59 
60 	for (i = 0; i < 0xff - 1; i++) {
61 		if (be32toh(fanout_table[i]) > be32toh(fanout_table[i + 1]))
62 			return got_error(GOT_ERR_BAD_PACKIDX);
63 	}
64 
65 	return NULL;
66 }
67 
68 const struct got_error *
69 got_pack_get_packfile_size(size_t *size, const char *path)
70 {
71 	struct stat sb;
72 	char *dot;
73 
74 	*size = 0;
75 
76 	dot = strrchr(path, '.');
77 	if (dot == NULL)
78 		return got_error(GOT_ERR_BAD_PATH);
79 
80 	/* Path must point to a pack index or to a pack file. */
81 	if (strcmp(dot, GOT_PACKIDX_SUFFIX) == 0) {
82 		const struct got_error *err = NULL;
83 		char *path_pack;
84 		char base_path[PATH_MAX];
85 
86 		/* Convert pack index path to pack file path. */
87 		if (strlcpy(base_path, path, PATH_MAX) > PATH_MAX)
88 			return got_error(GOT_ERR_NO_SPACE);
89 		dot = strrchr(base_path, '.');
90 		if (dot == NULL)
91 			return got_error(GOT_ERR_BAD_PATH);
92 		*dot = '\0';
93 		if (asprintf(&path_pack, "%s.pack", base_path) == -1)
94 			return got_error_from_errno();
95 
96 		if (stat(path_pack, &sb) != 0)
97 			err = got_error_from_errno();
98 		free(path_pack);
99 		if (err)
100 			return err;
101 	} else if (strcmp(dot, GOT_PACKFILE_SUFFIX) == 0) {
102 		if (stat(path, &sb) != 0)
103 			return got_error_from_errno();
104 	} else
105 		return got_error(GOT_ERR_BAD_PATH);
106 
107 	*size = sb.st_size;
108 	return 0;
109 }
110 
111 const struct got_error *
112 got_packidx_init_hdr(struct got_packidx *p, int verify)
113 {
114 	const struct got_error *err = NULL;
115 	struct got_packidx_v2_hdr *h;
116 	SHA1_CTX ctx;
117 	uint8_t sha1[SHA1_DIGEST_LENGTH];
118 	size_t nobj, len_fanout, len_ids, offset, remain;
119 	ssize_t n;
120 
121 	SHA1Init(&ctx);
122 
123 	h = &p->hdr;
124 	offset = 0;
125 	remain = p->len;
126 
127 	if (remain < sizeof(*h->magic)) {
128 		err = got_error(GOT_ERR_BAD_PACKIDX);
129 		goto done;
130 	}
131 	if (p->map)
132 		h->magic = (uint32_t *)(p->map + offset);
133 	else {
134 		h->magic = malloc(sizeof(*h->magic));
135 		if (h->magic == NULL) {
136 			err = got_error_from_errno();
137 			goto done;
138 		}
139 		n = read(p->fd, h->magic, sizeof(*h->magic));
140 		if (n < 0)
141 			err = got_error_from_errno();
142 		else if (n != sizeof(*h->magic)) {
143 			err = got_error(GOT_ERR_BAD_PACKIDX);
144 			goto done;
145 		}
146 	}
147 	if (betoh32(*h->magic) != GOT_PACKIDX_V2_MAGIC) {
148 		err = got_error(GOT_ERR_BAD_PACKIDX);
149 		goto done;
150 	}
151 	offset += sizeof(*h->magic);
152 	remain -= sizeof(*h->magic);
153 
154 	if (verify)
155 		SHA1Update(&ctx, (uint8_t *)h->magic, sizeof(*h->magic));
156 
157 	if (remain < sizeof(*h->version)) {
158 		err = got_error(GOT_ERR_BAD_PACKIDX);
159 		goto done;
160 	}
161 	if (p->map)
162 		h->version = (uint32_t *)(p->map + offset);
163 	else {
164 		h->version = malloc(sizeof(*h->version));
165 		if (h->version == NULL) {
166 			err = got_error_from_errno();
167 			goto done;
168 		}
169 		n = read(p->fd, h->version, sizeof(*h->version));
170 		if (n < 0)
171 			err = got_error_from_errno();
172 		else if (n != sizeof(*h->version)) {
173 			err = got_error(GOT_ERR_BAD_PACKIDX);
174 			goto done;
175 		}
176 	}
177 	if (betoh32(*h->version) != GOT_PACKIDX_VERSION) {
178 		err = got_error(GOT_ERR_BAD_PACKIDX);
179 		goto done;
180 	}
181 	offset += sizeof(*h->version);
182 	remain -= sizeof(*h->version);
183 
184 	if (verify)
185 		SHA1Update(&ctx, (uint8_t *)h->version, sizeof(*h->version));
186 
187 	len_fanout =
188 	    sizeof(*h->fanout_table) * GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS;
189 	if (remain < len_fanout) {
190 		err = got_error(GOT_ERR_BAD_PACKIDX);
191 		goto done;
192 	}
193 	if (p->map)
194 		h->fanout_table = (uint32_t *)(p->map + offset);
195 	else {
196 		h->fanout_table = malloc(len_fanout);
197 		if (h->fanout_table == NULL) {
198 			err = got_error_from_errno();
199 			goto done;
200 		}
201 		n = read(p->fd, h->fanout_table, len_fanout);
202 		if (n < 0)
203 			err = got_error_from_errno();
204 		else if (n != len_fanout) {
205 			err = got_error(GOT_ERR_BAD_PACKIDX);
206 			goto done;
207 		}
208 	}
209 	err = verify_fanout_table(h->fanout_table);
210 	if (err)
211 		goto done;
212 	if (verify)
213 		SHA1Update(&ctx, (uint8_t *)h->fanout_table, len_fanout);
214 	offset += len_fanout;
215 	remain -= len_fanout;
216 
217 	nobj = betoh32(h->fanout_table[0xff]);
218 	len_ids = nobj * sizeof(*h->sorted_ids);
219 	if (len_ids <= nobj || len_ids > remain) {
220 		err = got_error(GOT_ERR_BAD_PACKIDX);
221 		goto done;
222 	}
223 	if (p->map)
224 		h->sorted_ids =
225 		    (struct got_packidx_object_id *)((uint8_t*)(p->map + offset));
226 	else {
227 		h->sorted_ids = malloc(len_ids);
228 		if (h->sorted_ids == NULL) {
229 			err = got_error(GOT_ERR_BAD_PACKIDX);
230 			goto done;
231 		}
232 		n = read(p->fd, h->sorted_ids, len_ids);
233 		if (n < 0)
234 			err = got_error_from_errno();
235 		else if (n != len_ids) {
236 			err = got_error(GOT_ERR_BAD_PACKIDX);
237 			goto done;
238 		}
239 	}
240 	if (verify)
241 		SHA1Update(&ctx, (uint8_t *)h->sorted_ids, len_ids);
242 	offset += len_ids;
243 	remain -= len_ids;
244 
245 	if (remain < nobj * sizeof(*h->crc32)) {
246 		err = got_error(GOT_ERR_BAD_PACKIDX);
247 		goto done;
248 	}
249 	if (p->map)
250 		h->crc32 = (uint32_t *)((uint8_t*)(p->map + offset));
251 	else {
252 		h->crc32 = malloc(nobj * sizeof(*h->crc32));
253 		if (h->crc32 == NULL) {
254 			err = got_error_from_errno();
255 			goto done;
256 		}
257 		n = read(p->fd, h->crc32, nobj * sizeof(*h->crc32));
258 		if (n < 0)
259 			err = got_error_from_errno();
260 		else if (n != nobj * sizeof(*h->crc32)) {
261 			err = got_error(GOT_ERR_BAD_PACKIDX);
262 			goto done;
263 		}
264 	}
265 	if (verify)
266 		SHA1Update(&ctx, (uint8_t *)h->crc32, nobj * sizeof(*h->crc32));
267 	remain -= nobj * sizeof(*h->crc32);
268 	offset += nobj * sizeof(*h->crc32);
269 
270 	if (remain < nobj * sizeof(*h->offsets)) {
271 		err = got_error(GOT_ERR_BAD_PACKIDX);
272 		goto done;
273 	}
274 	if (p->map)
275 		h->offsets = (uint32_t *)((uint8_t*)(p->map + offset));
276 	else {
277 		h->offsets = malloc(nobj * sizeof(*h->offsets));
278 		if (h->offsets == NULL) {
279 			err = got_error_from_errno();
280 			goto done;
281 		}
282 		n = read(p->fd, h->offsets, nobj * sizeof(*h->offsets));
283 		if (n < 0)
284 			err = got_error_from_errno();
285 		else if (n != nobj * sizeof(*h->offsets)) {
286 			err = got_error(GOT_ERR_BAD_PACKIDX);
287 			goto done;
288 		}
289 	}
290 	if (verify)
291 		SHA1Update(&ctx, (uint8_t *)h->offsets,
292 		    nobj * sizeof(*h->offsets));
293 	remain -= nobj * sizeof(*h->offsets);
294 	offset += nobj * sizeof(*h->offsets);
295 
296 	/* Large file offsets are contained only in files > 2GB. */
297 	if (p->len <= 0x80000000)
298 		goto checksum;
299 
300 	if (remain < nobj * sizeof(*h->large_offsets)) {
301 		err = got_error(GOT_ERR_BAD_PACKIDX);
302 		goto done;
303 	}
304 	if (p->map)
305 		h->large_offsets = (uint64_t *)((uint8_t*)(p->map + offset));
306 	else {
307 		h->offsets = malloc(nobj * sizeof(*h->large_offsets));
308 		if (h->offsets == NULL) {
309 			err = got_error_from_errno();
310 			goto done;
311 		}
312 		n = read(p->fd, h->large_offsets,
313 		    nobj * sizeof(*h->large_offsets));
314 		if (n < 0)
315 			err = got_error_from_errno();
316 		else if (n != nobj * sizeof(*h->large_offsets)) {
317 			err = got_error(GOT_ERR_BAD_PACKIDX);
318 			goto done;
319 		}
320 	}
321 	if (verify)
322 		SHA1Update(&ctx, (uint8_t*)h->large_offsets,
323 		    nobj * sizeof(*h->large_offsets));
324 	remain -= nobj * sizeof(*h->large_offsets);
325 	offset += nobj * sizeof(*h->large_offsets);
326 
327 checksum:
328 	if (remain < sizeof(*h->trailer)) {
329 		err = got_error(GOT_ERR_BAD_PACKIDX);
330 		goto done;
331 	}
332 	if (p->map)
333 		h->trailer =
334 		    (struct got_packidx_trailer *)((uint8_t*)(p->map + offset));
335 	else {
336 		h->trailer = malloc(sizeof(*h->trailer));
337 		if (h->trailer == NULL) {
338 			err = got_error_from_errno();
339 			goto done;
340 		}
341 		n = read(p->fd, h->trailer, sizeof(*h->trailer));
342 		if (n < 0)
343 			err = got_error_from_errno();
344 		else if (n != sizeof(*h->trailer)) {
345 			err = got_error(GOT_ERR_BAD_PACKIDX);
346 			goto done;
347 		}
348 	}
349 	if (verify) {
350 		SHA1Update(&ctx, h->trailer->packfile_sha1, SHA1_DIGEST_LENGTH);
351 		SHA1Final(sha1, &ctx);
352 		if (memcmp(h->trailer->packidx_sha1, sha1,
353 		    SHA1_DIGEST_LENGTH) != 0)
354 			err = got_error(GOT_ERR_PACKIDX_CSUM);
355 	}
356 done:
357 	return err;
358 }
359 
360 const struct got_error *
361 got_packidx_open(struct got_packidx **packidx, const char *path, int verify)
362 {
363 	const struct got_error *err = NULL;
364 	struct got_packidx *p;
365 
366 	*packidx = NULL;
367 
368 	p = calloc(1, sizeof(*p));
369 	if (p == NULL)
370 		return got_error_from_errno();
371 
372 	p->fd = open(path, O_RDONLY | O_NOFOLLOW, GOT_DEFAULT_FILE_MODE);
373 	if (p->fd == -1)
374 		return got_error_from_errno();
375 
376 	err = got_pack_get_packfile_size(&p->len, path);
377 	if (err) {
378 		close(p->fd);
379 		free(p);
380 		return err;
381 	}
382 	if (p->len < sizeof(p->hdr)) {
383 		err = got_error(GOT_ERR_BAD_PACKIDX);
384 		close(p->fd);
385 		free(p);
386 		return err;
387 	}
388 
389 	p->path_packidx = strdup(path);
390 	if (p->path_packidx == NULL) {
391 		err = got_error_from_errno();
392 		goto done;
393 	}
394 
395 #ifndef GOT_PACK_NO_MMAP
396 	p->map = mmap(NULL, p->len, PROT_READ, MAP_PRIVATE, p->fd, 0);
397 	if (p->map == MAP_FAILED) {
398 		if (errno != ENOMEM) {
399 			err = got_error_from_errno();
400 			goto done;
401 		}
402 		p->map = NULL; /* fall back to read(2) */
403 	}
404 #endif
405 
406 	err = got_packidx_init_hdr(p, verify);
407 done:
408 	if (err)
409 		got_packidx_close(p);
410 	else
411 		*packidx = p;
412 
413 	return err;
414 }
415 
416 const struct got_error *
417 got_packidx_close(struct got_packidx *packidx)
418 {
419 	const struct got_error *err = NULL;
420 
421 	free(packidx->path_packidx);
422 	if (packidx->map) {
423 		if (munmap(packidx->map, packidx->len) == -1)
424 			err = got_error_from_errno();
425 	} else {
426 		free(packidx->hdr.magic);
427 		free(packidx->hdr.version);
428 		free(packidx->hdr.fanout_table);
429 		free(packidx->hdr.sorted_ids);
430 		free(packidx->hdr.crc32);
431 		free(packidx->hdr.offsets);
432 		free(packidx->hdr.large_offsets);
433 		free(packidx->hdr.trailer);
434 	}
435 	if (close(packidx->fd) != 0 && err == NULL)
436 		err = got_error_from_errno();
437 	free(packidx);
438 
439 	return err;
440 }
441 
442 static off_t
443 get_object_offset(struct got_packidx *packidx, int idx)
444 {
445 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
446 	uint32_t offset = betoh32(packidx->hdr.offsets[idx]);
447 	if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
448 		uint64_t loffset;
449 		idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
450 		if (idx < 0 || idx > totobj ||
451 		    packidx->hdr.large_offsets == NULL)
452 			return -1;
453 		loffset = betoh64(packidx->hdr.large_offsets[idx]);
454 		return (loffset > INT64_MAX ? -1 : (off_t)loffset);
455 	}
456 	return (off_t)(offset & GOT_PACKIDX_OFFSET_VAL_MASK);
457 }
458 
459 int
460 got_packidx_get_object_idx(struct got_packidx *packidx, struct got_object_id *id)
461 {
462 	u_int8_t id0 = id->sha1[0];
463 	uint32_t totobj = betoh32(packidx->hdr.fanout_table[0xff]);
464 	int left = 0, right = totobj - 1;
465 
466 	if (id0 > 0)
467 		left = betoh32(packidx->hdr.fanout_table[id0 - 1]);
468 
469 	while (left <= right) {
470 		struct got_packidx_object_id *oid;
471 		int i, cmp;
472 
473 		i = ((left + right) / 2);
474 		oid = &packidx->hdr.sorted_ids[i];
475 		cmp = memcmp(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
476 		if (cmp == 0)
477 			return i;
478 		else if (cmp > 0)
479 			left = i + 1;
480 		else if (cmp < 0)
481 			right = i - 1;
482 	}
483 
484 	return -1;
485 }
486 
487 const struct got_error *
488 got_pack_stop_privsep_child(struct got_pack *pack)
489 {
490 	const struct got_error *err = NULL;
491 
492 	if (pack->privsep_child == NULL)
493 		return NULL;
494 
495 	err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
496 	if (err)
497 		return err;
498 	err = got_privsep_wait_for_child(pack->privsep_child->pid);
499 	free(pack->privsep_child);
500 	pack->privsep_child = NULL;
501 	return err;
502 }
503 
504 const struct got_error *
505 got_pack_close(struct got_pack *pack)
506 {
507 	const struct got_error *err = NULL;
508 
509 	err = got_pack_stop_privsep_child(pack);
510 	if (pack->map && munmap(pack->map, pack->filesize) == -1 && !err)
511 		err = got_error_from_errno();
512 	if (pack->fd != -1 && close(pack->fd) != 0 && err == NULL)
513 		err = got_error_from_errno();
514 	pack->fd = -1;
515 	free(pack->path_packfile);
516 	pack->path_packfile = NULL;
517 	pack->filesize = 0;
518 
519 	return err;
520 }
521 
522 static const struct got_error *
523 parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len,
524     struct got_pack *pack, off_t offset)
525 {
526 	uint8_t t = 0;
527 	uint64_t s = 0;
528 	uint8_t sizeN;
529 	size_t mapoff = 0;
530 	int i = 0;
531 
532 	*len = 0;
533 
534 	if (offset >= pack->filesize)
535 		return got_error(GOT_ERR_PACK_OFFSET);
536 
537 	if (pack->map) {
538 		mapoff = (size_t)offset;
539 	} else {
540 		if (lseek(pack->fd, offset, SEEK_SET) == -1)
541 			return got_error_from_errno();
542 	}
543 
544 	do {
545 		/* We do not support size values which don't fit in 64 bit. */
546 		if (i > 9)
547 			return got_error(GOT_ERR_NO_SPACE);
548 
549 		if (pack->map) {
550 			sizeN = *(pack->map + mapoff);
551 			mapoff += sizeof(sizeN);
552 		} else {
553 			ssize_t n = read(pack->fd, &sizeN, sizeof(sizeN));
554 			if (n < 0)
555 				return got_error_from_errno();
556 			if (n != sizeof(sizeN))
557 				return got_error(GOT_ERR_BAD_PACKFILE);
558 		}
559 		*len += sizeof(sizeN);
560 
561 		if (i == 0) {
562 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
563 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
564 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
565 		} else {
566 			size_t shift = 4 + 7 * (i - 1);
567 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
568 		}
569 		i++;
570 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
571 
572 	*type = t;
573 	*size = s;
574 	return NULL;
575 }
576 
577 static const struct got_error *
578 open_plain_object(struct got_object **obj, const char *path_packfile,
579     struct got_object_id *id, uint8_t type, off_t offset, size_t size, int idx)
580 {
581 	*obj = calloc(1, sizeof(**obj));
582 	if (*obj == NULL)
583 		return got_error_from_errno();
584 
585 	(*obj)->path_packfile = strdup(path_packfile);
586 	if ((*obj)->path_packfile == NULL) {
587 		const struct got_error *err = got_error_from_errno();
588 		free(*obj);
589 		*obj = NULL;
590 		return err;
591 	}
592 
593 	(*obj)->type = type;
594 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
595 	(*obj)->pack_idx = idx;
596 	(*obj)->hdrlen = 0;
597 	(*obj)->size = size;
598 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
599 	(*obj)->pack_offset = offset;
600 
601 	return NULL;
602 }
603 
604 static const struct got_error *
605 parse_negative_offset(int64_t *offset, size_t *len, struct got_pack *pack,
606     off_t delta_offset)
607 {
608 	int64_t o = 0;
609 	uint8_t offN;
610 	int i = 0;
611 
612 	*len = 0;
613 
614 	do {
615 		/* We do not support offset values which don't fit in 64 bit. */
616 		if (i > 8)
617 			return got_error(GOT_ERR_NO_SPACE);
618 
619 		if (pack->map) {
620 			size_t mapoff;
621 			if (delta_offset >= pack->filesize)
622 				return got_error(GOT_ERR_PACK_OFFSET);
623 			mapoff = (size_t)delta_offset + *len;
624 			offN = *(pack->map + mapoff);
625 		} else {
626 			ssize_t n;
627 			n = read(pack->fd, &offN, sizeof(offN));
628 			if (n < 0)
629 				return got_error_from_errno();
630 			if (n != sizeof(offN))
631 				return got_error(GOT_ERR_BAD_PACKFILE);
632 		}
633 		*len += sizeof(offN);
634 
635 		if (i == 0)
636 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
637 		else {
638 			o++;
639 			o <<= 7;
640 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
641 		}
642 		i++;
643 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
644 
645 	*offset = o;
646 	return NULL;
647 }
648 
649 static const struct got_error *
650 parse_offset_delta(off_t *base_offset, size_t *len, struct got_pack *pack,
651     off_t offset, int tslen)
652 {
653 	const struct got_error *err;
654 	int64_t negoffset;
655 	size_t negofflen;
656 
657 	*len = 0;
658 
659 	err = parse_negative_offset(&negoffset, &negofflen, pack,
660 	    offset + tslen);
661 	if (err)
662 		return err;
663 
664 	/* Compute the base object's offset (must be in the same pack file). */
665 	*base_offset = (offset - negoffset);
666 	if (*base_offset <= 0)
667 		return got_error(GOT_ERR_BAD_PACKFILE);
668 
669 	*len = negofflen;
670 	return NULL;
671 }
672 
673 static const struct got_error *
674 resolve_delta_chain(struct got_delta_chain *, struct got_packidx *,
675     struct got_pack *, off_t, size_t, int, size_t, unsigned int);
676 
677 static const struct got_error *
678 add_delta(struct got_delta_chain *deltas, off_t delta_offset, size_t tslen,
679     int delta_type, size_t delta_size, size_t delta_data_offset,
680     uint8_t *delta_buf, size_t delta_len)
681 {
682 	struct got_delta *delta;
683 
684 	delta = got_delta_open(delta_offset, tslen, delta_type, delta_size,
685 	    delta_data_offset, delta_buf,
686 	    delta_len);
687 	if (delta == NULL)
688 		return got_error_from_errno();
689 	/* delta is freed in got_object_close() */
690 	deltas->nentries++;
691 	SIMPLEQ_INSERT_HEAD(&deltas->entries, delta, entry);
692 	return NULL;
693 }
694 
695 static const struct got_error *
696 resolve_offset_delta(struct got_delta_chain *deltas,
697     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
698     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
699 
700 {
701 	const struct got_error *err;
702 	off_t base_offset;
703 	uint8_t base_type;
704 	uint64_t base_size;
705 	size_t base_tslen;
706 	off_t delta_data_offset;
707 	uint8_t *delta_buf;
708 	size_t delta_len, consumed;
709 
710 	err = parse_offset_delta(&base_offset, &consumed, pack,
711 	    delta_offset, tslen);
712 	if (err)
713 		return err;
714 
715 	delta_data_offset = delta_offset + tslen + consumed;
716 	if (delta_data_offset >= pack->filesize)
717 		return got_error(GOT_ERR_PACK_OFFSET);
718 
719 	if (pack->map == NULL) {
720 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
721 		if (delta_data_offset == -1)
722 			return got_error_from_errno();
723 	}
724 
725 	if (pack->map) {
726 		size_t mapoff = (size_t)delta_data_offset;
727 		err = got_inflate_to_mem_mmap(&delta_buf, &delta_len, pack->map,
728 		    mapoff, pack->filesize - mapoff);
729 		if (err)
730 			return err;
731 	} else {
732 
733 		err = got_inflate_to_mem_fd(&delta_buf, &delta_len, pack->fd);
734 		if (err)
735 			return err;
736 	}
737 
738 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
739 	    delta_data_offset, delta_buf, delta_len);
740 	if (err)
741 		goto done;
742 
743 	/* An offset delta must be in the same packfile. */
744 	if (base_offset >= pack->filesize) {
745 		err = got_error(GOT_ERR_PACK_OFFSET);
746 		goto done;
747 	}
748 
749 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
750 	    pack, base_offset);
751 	if (err)
752 		goto done;
753 
754 	err = resolve_delta_chain(deltas, packidx, pack, base_offset,
755 	    base_tslen, base_type, base_size, recursion - 1);
756 done:
757 	if (err)
758 		free(delta_buf);
759 	return err;
760 }
761 
762 static const struct got_error *
763 resolve_ref_delta(struct got_delta_chain *deltas, struct got_packidx *packidx,
764     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
765     size_t delta_size, unsigned int recursion)
766 {
767 	const struct got_error *err;
768 	struct got_object_id id;
769 	int idx;
770 	off_t base_offset;
771 	uint8_t base_type;
772 	uint64_t base_size;
773 	size_t base_tslen;
774 	off_t delta_data_offset;
775 	uint8_t *delta_buf = NULL;
776 	size_t delta_len;
777 
778 	if (delta_offset >= pack->filesize)
779 		return got_error(GOT_ERR_PACK_OFFSET);
780 	delta_data_offset = delta_offset + tslen;
781 	if (delta_data_offset >= pack->filesize)
782 		return got_error(GOT_ERR_PACK_OFFSET);
783 
784 	if (pack->map == NULL) {
785 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
786 		if (delta_data_offset == -1)
787 			return got_error_from_errno();
788 	}
789 
790 
791 	if (pack->map) {
792 		size_t mapoff = (size_t)delta_data_offset;
793 		memcpy(&id, pack->map + mapoff, sizeof(id));
794 		mapoff += sizeof(id);
795 		err = got_inflate_to_mem_mmap(&delta_buf, &delta_len, pack->map,
796 		    mapoff, pack->filesize - mapoff);
797 		if (err)
798 			goto done;
799 	} else {
800 		ssize_t n = read(pack->fd, &id, sizeof(id));
801 		if (n < 0)
802 			return got_error_from_errno();
803 		if (n != sizeof(id))
804 			return got_error(GOT_ERR_BAD_PACKFILE);
805 		err = got_inflate_to_mem_fd(&delta_buf, &delta_len, pack->fd);
806 		if (err)
807 			goto done;
808 	}
809 
810 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
811 	    delta_data_offset, delta_buf, delta_len);
812 	if (err)
813 		goto done;
814 
815 	/* Delta base must be in the same pack file. */
816 	idx = got_packidx_get_object_idx(packidx, &id);
817 	if (idx == -1) {
818 		err = got_error(GOT_ERR_BAD_PACKFILE);
819 		goto done;
820 	}
821 
822 	base_offset = get_object_offset(packidx, idx);
823 	if (base_offset == (uint64_t)-1) {
824 		err = got_error(GOT_ERR_BAD_PACKIDX);
825 		goto done;
826 	}
827 
828 	if (base_offset >= pack->filesize) {
829 		err = got_error(GOT_ERR_PACK_OFFSET);
830 		goto done;
831 	}
832 
833 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
834 	    pack, base_offset);
835 	if (err)
836 		goto done;
837 
838 	err = resolve_delta_chain(deltas, packidx, pack, base_offset,
839 	    base_tslen, base_type, base_size, recursion - 1);
840 done:
841 	if (err)
842 		free(delta_buf);
843 	return err;
844 }
845 
846 static const struct got_error *
847 resolve_delta_chain(struct got_delta_chain *deltas, struct got_packidx *packidx,
848     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
849     size_t delta_size, unsigned int recursion)
850 {
851 	const struct got_error *err = NULL;
852 
853 	if (--recursion == 0)
854 		return got_error(GOT_ERR_RECURSION);
855 
856 	switch (delta_type) {
857 	case GOT_OBJ_TYPE_COMMIT:
858 	case GOT_OBJ_TYPE_TREE:
859 	case GOT_OBJ_TYPE_BLOB:
860 	case GOT_OBJ_TYPE_TAG:
861 		/* Plain types are the final delta base. Recursion ends. */
862 		err = add_delta(deltas, delta_offset, tslen, delta_type,
863 		    delta_size, 0, NULL, 0);
864 		break;
865 	case GOT_OBJ_TYPE_OFFSET_DELTA:
866 		err = resolve_offset_delta(deltas, packidx, pack,
867 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
868 		break;
869 	case GOT_OBJ_TYPE_REF_DELTA:
870 		err = resolve_ref_delta(deltas, packidx, pack,
871 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
872 		break;
873 	default:
874 		return got_error(GOT_ERR_OBJ_TYPE);
875 	}
876 
877 	return err;
878 }
879 
880 static const struct got_error *
881 open_delta_object(struct got_object **obj, struct got_packidx *packidx,
882     struct got_pack *pack, struct got_object_id *id, off_t offset,
883     size_t tslen, int delta_type, size_t delta_size, int idx)
884 {
885 	const struct got_error *err = NULL;
886 	int resolved_type;
887 
888 	*obj = calloc(1, sizeof(**obj));
889 	if (*obj == NULL)
890 		return got_error_from_errno();
891 
892 	(*obj)->flags = 0;
893 	(*obj)->hdrlen = 0;
894 	(*obj)->size = 0; /* Not known because deltas aren't applied yet. */
895 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
896 	(*obj)->pack_offset = offset + tslen;
897 
898 	(*obj)->path_packfile = strdup(pack->path_packfile);
899 	if ((*obj)->path_packfile == NULL) {
900 		err = got_error_from_errno();
901 		goto done;
902 	}
903 	(*obj)->flags |= GOT_OBJ_FLAG_PACKED;
904 	(*obj)->pack_idx = idx;
905 
906 	SIMPLEQ_INIT(&(*obj)->deltas.entries);
907 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
908 
909 	err = resolve_delta_chain(&(*obj)->deltas, packidx, pack, offset,
910 	    tslen, delta_type, delta_size, GOT_DELTA_CHAIN_RECURSION_MAX);
911 	if (err)
912 		goto done;
913 
914 	err = got_delta_chain_get_base_type(&resolved_type, &(*obj)->deltas);
915 	if (err)
916 		goto done;
917 	(*obj)->type = resolved_type;
918 done:
919 	if (err) {
920 		got_object_close(*obj);
921 		*obj = NULL;
922 	}
923 	return err;
924 }
925 
926 const struct got_error *
927 got_packfile_open_object(struct got_object **obj, struct got_pack *pack,
928     struct got_packidx *packidx, int idx, struct got_object_id *id)
929 {
930 	const struct got_error *err = NULL;
931 	off_t offset;
932 	uint8_t type;
933 	uint64_t size;
934 	size_t tslen;
935 
936 	*obj = NULL;
937 
938 	offset = get_object_offset(packidx, idx);
939 	if (offset == (uint64_t)-1)
940 		return got_error(GOT_ERR_BAD_PACKIDX);
941 
942 	err = parse_object_type_and_size(&type, &size, &tslen, pack, offset);
943 	if (err)
944 		return err;
945 
946 	switch (type) {
947 	case GOT_OBJ_TYPE_COMMIT:
948 	case GOT_OBJ_TYPE_TREE:
949 	case GOT_OBJ_TYPE_BLOB:
950 	case GOT_OBJ_TYPE_TAG:
951 		err = open_plain_object(obj, pack->path_packfile, id, type,
952 		    offset + tslen, size, idx);
953 		break;
954 	case GOT_OBJ_TYPE_OFFSET_DELTA:
955 	case GOT_OBJ_TYPE_REF_DELTA:
956 		err = open_delta_object(obj, packidx, pack, id, offset,
957 		    tslen, type, size, idx);
958 		break;
959 	default:
960 		err = got_error(GOT_ERR_OBJ_TYPE);
961 		break;
962 	}
963 
964 	return err;
965 }
966 
967 static const struct got_error *
968 get_delta_chain_max_size(uint64_t *max_size, struct got_delta_chain *deltas)
969 {
970 	struct got_delta *delta;
971 	uint64_t base_size = 0, result_size = 0;
972 
973 	*max_size = 0;
974 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
975 		/* Plain object types are the delta base. */
976 		if (delta->type != GOT_OBJ_TYPE_COMMIT &&
977 		    delta->type != GOT_OBJ_TYPE_TREE &&
978 		    delta->type != GOT_OBJ_TYPE_BLOB &&
979 		    delta->type != GOT_OBJ_TYPE_TAG) {
980 			const struct got_error *err;
981 			err = got_delta_get_sizes(&base_size, &result_size,
982 			    delta->delta_buf, delta->delta_len);
983 			if (err)
984 				return err;
985 		} else
986 			base_size = delta->size;
987 		if (base_size > *max_size)
988 			*max_size = base_size;
989 		if (result_size > *max_size)
990 			*max_size = result_size;
991 	}
992 
993 	return NULL;
994 }
995 
996 const struct got_error *
997 got_pack_get_max_delta_object_size(uint64_t *size, struct got_object *obj)
998 {
999 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0)
1000 		return got_error(GOT_ERR_OBJ_TYPE);
1001 
1002 	return get_delta_chain_max_size(size, &obj->deltas);
1003 }
1004 
1005 static const struct got_error *
1006 dump_delta_chain_to_file(size_t *result_size, struct got_delta_chain *deltas,
1007     struct got_pack *pack, FILE *outfile, FILE *base_file, FILE *accum_file)
1008 {
1009 	const struct got_error *err = NULL;
1010 	struct got_delta *delta;
1011 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1012 	size_t base_bufsz = 0, accum_size = 0;
1013 	uint64_t max_size;
1014 	int n = 0;
1015 
1016 	*result_size = 0;
1017 
1018 	if (SIMPLEQ_EMPTY(&deltas->entries))
1019 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1020 
1021 	/* We process small enough files entirely in memory for speed. */
1022 	err = get_delta_chain_max_size(&max_size, deltas);
1023 	if (err)
1024 		return err;
1025 	if (max_size < GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
1026 		accum_buf = malloc(max_size);
1027 		if (accum_buf == NULL)
1028 			return got_error_from_errno();
1029 		base_file = NULL;
1030 		accum_file = NULL;
1031 	}
1032 
1033 	/* Deltas are ordered in ascending order. */
1034 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1035 		if (n == 0) {
1036 			size_t mapoff;
1037 			off_t delta_data_offset;
1038 
1039 			/* Plain object types are the delta base. */
1040 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1041 			    delta->type != GOT_OBJ_TYPE_TREE &&
1042 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1043 			    delta->type != GOT_OBJ_TYPE_TAG) {
1044 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1045 				goto done;
1046 			}
1047 
1048 			delta_data_offset = delta->offset + delta->tslen;
1049 			if (delta_data_offset >= pack->filesize) {
1050 				err = got_error(GOT_ERR_PACK_OFFSET);
1051 				goto done;
1052 			}
1053 			if (pack->map == NULL) {
1054 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1055 				    == -1) {
1056 					err = got_error_from_errno();
1057 					goto done;
1058 				}
1059 			}
1060 			if (base_file) {
1061 				if (pack->map) {
1062 					mapoff = (size_t)delta_data_offset;
1063 					err = got_inflate_to_file_mmap(
1064 					    &base_bufsz, pack->map, mapoff,
1065 					    pack->filesize - mapoff, base_file);
1066 				} else
1067 					err = got_inflate_to_file_fd(
1068 					    &base_bufsz, pack->fd, base_file);
1069 			} else {
1070 				if (pack->map) {
1071 					mapoff = (size_t)delta_data_offset;
1072 					err = got_inflate_to_mem_mmap(&base_buf,
1073 					    &base_bufsz, pack->map, mapoff,
1074 					    pack->filesize - mapoff);
1075 				} else
1076 					err = got_inflate_to_mem_fd(&base_buf,
1077 					    &base_bufsz, pack->fd);
1078 			}
1079 			if (err)
1080 				goto done;
1081 			n++;
1082 			if (base_file)
1083 				rewind(base_file);
1084 			continue;
1085 		}
1086 
1087 		if (base_buf) {
1088 			err = got_delta_apply_in_mem(base_buf, base_bufsz,
1089 			    delta->delta_buf, delta->delta_len, accum_buf,
1090 			    &accum_size, max_size);
1091 			n++;
1092 		} else {
1093 			err = got_delta_apply(base_file, delta->delta_buf,
1094 			    delta->delta_len,
1095 			    /* Final delta application writes to output file. */
1096 			    ++n < deltas->nentries ? accum_file : outfile,
1097 			    &accum_size);
1098 		}
1099 		if (err)
1100 			goto done;
1101 
1102 		if (n < deltas->nentries) {
1103 			/* Accumulated delta becomes the new base. */
1104 			if (base_buf) {
1105 				uint8_t *tmp = accum_buf;
1106 				/*
1107 				 * Base buffer switches roles with accumulation
1108 				 * buffer. Ensure it can hold the largest
1109 				 * result in the delta chain. The initial
1110 				 * allocation might have been smaller.
1111 				 */
1112 				if (base_bufsz < max_size) {
1113 					uint8_t *p;
1114 					p = reallocarray(base_buf, 1, max_size);
1115 					if (p == NULL) {
1116 						err = got_error_from_errno();
1117 						goto done;
1118 					}
1119 					base_buf = p;
1120 					base_bufsz = max_size;
1121 				}
1122 				accum_buf = base_buf;
1123 				base_buf = tmp;
1124 			} else {
1125 				FILE *tmp = accum_file;
1126 				accum_file = base_file;
1127 				base_file = tmp;
1128 				rewind(base_file);
1129 				rewind(accum_file);
1130 			}
1131 		}
1132 	}
1133 
1134 done:
1135 	free(base_buf);
1136 	if (accum_buf) {
1137 		size_t len = fwrite(accum_buf, 1, accum_size, outfile);
1138 		free(accum_buf);
1139 		if (len != accum_size)
1140 			err = got_ferror(outfile, GOT_ERR_IO);
1141 	}
1142 	rewind(outfile);
1143 	if (err == NULL)
1144 		*result_size = accum_size;
1145 	return err;
1146 }
1147 
1148 static const struct got_error *
1149 dump_delta_chain_to_mem(uint8_t **outbuf, size_t *outlen,
1150     struct got_delta_chain *deltas, struct got_pack *pack)
1151 {
1152 	const struct got_error *err = NULL;
1153 	struct got_delta *delta;
1154 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1155 	size_t base_bufsz = 0, accum_size = 0;
1156 	uint64_t max_size;
1157 	int n = 0;
1158 
1159 	*outbuf = NULL;
1160 	*outlen = 0;
1161 
1162 	if (SIMPLEQ_EMPTY(&deltas->entries))
1163 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1164 
1165 	err = get_delta_chain_max_size(&max_size, deltas);
1166 	if (err)
1167 		return err;
1168 	accum_buf = malloc(max_size);
1169 	if (accum_buf == NULL)
1170 		return got_error_from_errno();
1171 
1172 	/* Deltas are ordered in ascending order. */
1173 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
1174 		if (n == 0) {
1175 			size_t delta_data_offset;
1176 
1177 			/* Plain object types are the delta base. */
1178 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1179 			    delta->type != GOT_OBJ_TYPE_TREE &&
1180 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1181 			    delta->type != GOT_OBJ_TYPE_TAG) {
1182 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1183 				goto done;
1184 			}
1185 
1186 			delta_data_offset = delta->offset + delta->tslen;
1187 			if (delta_data_offset >= pack->filesize) {
1188 				err = got_error(GOT_ERR_PACK_OFFSET);
1189 				goto done;
1190 			}
1191 			if (pack->map) {
1192 				size_t mapoff = (size_t)delta_data_offset;
1193 				err = got_inflate_to_mem_mmap(&base_buf,
1194 				    &base_bufsz, pack->map, mapoff,
1195 				    pack->filesize - mapoff);
1196 			} else {
1197 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1198 				    == -1) {
1199 					err = got_error_from_errno();
1200 					goto done;
1201 				}
1202 				err = got_inflate_to_mem_fd(&base_buf,
1203 				    &base_bufsz, pack->fd);
1204 			}
1205 			if (err)
1206 				goto done;
1207 			n++;
1208 			continue;
1209 		}
1210 
1211 		err = got_delta_apply_in_mem(base_buf, base_bufsz,
1212 		    delta->delta_buf, delta->delta_len, accum_buf,
1213 		    &accum_size, max_size);
1214 		n++;
1215 		if (err)
1216 			goto done;
1217 
1218 		if (n < deltas->nentries) {
1219 			/* Accumulated delta becomes the new base. */
1220 			uint8_t *tmp = accum_buf;
1221 			/*
1222 			 * Base buffer switches roles with accumulation buffer.
1223 			 * Ensure it can hold the largest result in the delta
1224 			 * chain. Initial allocation might have been smaller.
1225 			 */
1226 			if (base_bufsz < max_size) {
1227 				uint8_t *p;
1228 				p = reallocarray(base_buf, 1, max_size);
1229 				if (p == NULL) {
1230 					err = got_error_from_errno();
1231 					goto done;
1232 				}
1233 				base_buf = p;
1234 				base_bufsz = max_size;
1235 			}
1236 			accum_buf = base_buf;
1237 			base_buf = tmp;
1238 		}
1239 	}
1240 
1241 done:
1242 	free(base_buf);
1243 	if (err) {
1244 		free(accum_buf);
1245 		*outbuf = NULL;
1246 		*outlen = 0;
1247 	} else {
1248 		*outbuf = accum_buf;
1249 		*outlen = accum_size;
1250 	}
1251 	return err;
1252 }
1253 
1254 const struct got_error *
1255 got_packfile_extract_object(struct got_pack *pack, struct got_object *obj,
1256     FILE *outfile, FILE *base_file, FILE *accum_file)
1257 {
1258 	const struct got_error *err = NULL;
1259 
1260 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1261 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1262 
1263 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1264 		if (obj->pack_offset >= pack->filesize)
1265 			return got_error(GOT_ERR_PACK_OFFSET);
1266 
1267 		if (pack->map) {
1268 			size_t mapoff = (size_t)obj->pack_offset;
1269 			err = got_inflate_to_file_mmap(&obj->size, pack->map,
1270 			    mapoff, pack->filesize - mapoff, outfile);
1271 		} else {
1272 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1273 				return got_error_from_errno();
1274 			err = got_inflate_to_file_fd(&obj->size, pack->fd,
1275 			    outfile);
1276 		}
1277 	} else
1278 		err = dump_delta_chain_to_file(&obj->size, &obj->deltas, pack,
1279 		    outfile, base_file, accum_file);
1280 
1281 	return err;
1282 }
1283 
1284 const struct got_error *
1285 got_packfile_extract_object_to_mem(uint8_t **buf, size_t *len,
1286     struct got_object *obj, struct got_pack *pack)
1287 {
1288 	const struct got_error *err = NULL;
1289 
1290 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1291 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1292 
1293 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1294 		if (obj->pack_offset >= pack->filesize)
1295 			return got_error(GOT_ERR_PACK_OFFSET);
1296 		if (pack->map) {
1297 			size_t mapoff = (size_t)obj->pack_offset;
1298 			err = got_inflate_to_mem_mmap(buf, len, pack->map,
1299 			    mapoff, pack->filesize - mapoff);
1300 		} else {
1301 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1302 				return got_error_from_errno();
1303 			err = got_inflate_to_mem_fd(buf, len, pack->fd);
1304 		}
1305 	} else
1306 		err = dump_delta_chain_to_mem(buf, len, &obj->deltas, pack);
1307 
1308 	return err;
1309 }