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Date:: Mon Feb 12 22:25:38 2018 UTC
Message:: rename private header filenames so they are in got_ namespace
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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 
21 #include <dirent.h>
22 #include <errno.h>
23 #include <stdio.h>
24 #include <stdint.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <limits.h>
28 #include <sha1.h>
29 #include <endian.h>
30 #include <zlib.h>
31 
32 #include "got_error.h"
33 #include "got_object.h"
34 #include "got_repository.h"
35 
36 #include "got_sha1_priv.h"
37 #include "got_pack_priv.h"
38 #include "got_path_priv.h"
39 #include "got_delta_priv.h"
40 #include "got_zb_priv.h"
41 #include "got_object_priv.h"
42 
43 #define GOT_PACK_PREFIX		"pack-"
44 #define GOT_PACKFILE_SUFFIX	".pack"
45 #define GOT_PACKIDX_SUFFIX		".idx"
46 #define GOT_PACKFILE_NAMELEN	(strlen(GOT_PACK_PREFIX) + \
47 				SHA1_DIGEST_STRING_LENGTH - 1 + \
48 				strlen(GOT_PACKFILE_SUFFIX))
49 #define GOT_PACKIDX_NAMELEN	(strlen(GOT_PACK_PREFIX) + \
50 				SHA1_DIGEST_STRING_LENGTH - 1 + \
51 				strlen(GOT_PACKIDX_SUFFIX))
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 static const struct got_error *
71 get_packfile_size(size_t *size, const char *path_idx)
72 {
73 	struct stat sb;
74 	char *path_pack;
75 	char base_path[PATH_MAX];
76 	char *dot;
77 
78 	if (strlcpy(base_path, path_idx, PATH_MAX) > PATH_MAX)
79 		return got_error(GOT_ERR_NO_SPACE);
80 
81 	dot = strrchr(base_path, '.');
82 	if (dot == NULL)
83 		return got_error(GOT_ERR_BAD_PATH);
84 	*dot = '\0';
85 	if (asprintf(&path_pack, "%s.pack", base_path) == -1)
86 		return got_error(GOT_ERR_NO_MEM);
87 
88 	if (stat(path_pack, &sb) != 0) {
89 		free(path_pack);
90 		return got_error_from_errno();
91 	}
92 
93 	free(path_pack);
94 	*size = sb.st_size;
95 	return 0;
96 }
97 
98 const struct got_error *
99 got_packidx_open(struct got_packidx_v2_hdr **packidx, const char *path)
100 {
101 	struct got_packidx_v2_hdr *p;
102 	FILE *f;
103 	const struct got_error *err = NULL;
104 	size_t n, nobj, packfile_size;
105 	SHA1_CTX ctx;
106 	uint8_t sha1[SHA1_DIGEST_LENGTH];
107 
108 	SHA1Init(&ctx);
109 
110 	f = fopen(path, "rb");
111 	if (f == NULL)
112 		return got_error(GOT_ERR_BAD_PATH);
113 
114 	err = get_packfile_size(&packfile_size, path);
115 	if (err)
116 		return err;
117 
118 	p = calloc(1, sizeof(*p));
119 	if (p == NULL) {
120 		err = got_error(GOT_ERR_NO_MEM);
121 		goto done;
122 	}
123 
124 	n = fread(&p->magic, sizeof(p->magic), 1, f);
125 	if (n != 1) {
126 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
127 		goto done;
128 	}
129 
130 	if (betoh32(p->magic) != GOT_PACKIDX_V2_MAGIC) {
131 		err = got_error(GOT_ERR_BAD_PACKIDX);
132 		goto done;
133 	}
134 
135 	SHA1Update(&ctx, (uint8_t *)&p->magic, sizeof(p->magic));
136 
137 	n = fread(&p->version, sizeof(p->version), 1, f);
138 	if (n != 1) {
139 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
140 		goto done;
141 	}
142 
143 	if (betoh32(p->version) != GOT_PACKIDX_VERSION) {
144 		err = got_error(GOT_ERR_BAD_PACKIDX);
145 		goto done;
146 	}
147 
148 	SHA1Update(&ctx, (uint8_t *)&p->version, sizeof(p->version));
149 
150 	n = fread(&p->fanout_table, sizeof(p->fanout_table), 1, f);
151 	if (n != 1) {
152 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
153 		goto done;
154 	}
155 
156 	err = verify_fanout_table(p->fanout_table);
157 	if (err)
158 		goto done;
159 
160 	SHA1Update(&ctx, (uint8_t *)p->fanout_table, sizeof(p->fanout_table));
161 
162 	nobj = betoh32(p->fanout_table[0xff]);
163 
164 	p->sorted_ids = calloc(nobj, sizeof(*p->sorted_ids));
165 	if (p->sorted_ids == NULL) {
166 		err = got_error(GOT_ERR_NO_MEM);
167 		goto done;
168 	}
169 
170 	n = fread(p->sorted_ids, sizeof(*p->sorted_ids), nobj, f);
171 	if (n != nobj) {
172 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
173 		goto done;
174 	}
175 
176 	SHA1Update(&ctx, (uint8_t *)p->sorted_ids,
177 	    nobj * sizeof(*p->sorted_ids));
178 
179 	p->crc32 = calloc(nobj, sizeof(*p->crc32));
180 	if (p->crc32 == NULL) {
181 		err = got_error(GOT_ERR_NO_MEM);
182 		goto done;
183 	}
184 
185 	n = fread(p->crc32, sizeof(*p->crc32), nobj, f);
186 	if (n != nobj) {
187 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
188 		goto done;
189 	}
190 
191 	SHA1Update(&ctx, (uint8_t *)p->crc32, nobj * sizeof(*p->crc32));
192 
193 	p->offsets = calloc(nobj, sizeof(*p->offsets));
194 	if (p->offsets == NULL) {
195 		err = got_error(GOT_ERR_NO_MEM);
196 		goto done;
197 	}
198 
199 	n = fread(p->offsets, sizeof(*p->offsets), nobj, f);
200 	if (n != nobj) {
201 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
202 		goto done;
203 	}
204 
205 	SHA1Update(&ctx, (uint8_t *)p->offsets, nobj * sizeof(*p->offsets));
206 
207 	/* Large file offsets are contained only in files > 2GB. */
208 	if (packfile_size <= 0x80000000)
209 		goto checksum;
210 
211 	p->large_offsets = calloc(nobj, sizeof(*p->large_offsets));
212 	if (p->large_offsets == NULL) {
213 		err = got_error(GOT_ERR_NO_MEM);
214 		goto done;
215 	}
216 
217 	n = fread(p->large_offsets, sizeof(*p->large_offsets), nobj, f);
218 	if (n != nobj) {
219 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
220 		goto done;
221 	}
222 
223 	SHA1Update(&ctx, (uint8_t*)p->large_offsets,
224 	    nobj * sizeof(*p->large_offsets));
225 
226 checksum:
227 	n = fread(&p->trailer, sizeof(p->trailer), 1, f);
228 	if (n != 1) {
229 		err = got_ferror(f, GOT_ERR_BAD_PACKIDX);
230 		goto done;
231 	}
232 
233 	SHA1Update(&ctx, p->trailer.packfile_sha1, SHA1_DIGEST_LENGTH);
234 	SHA1Final(sha1, &ctx);
235 	if (memcmp(p->trailer.packidx_sha1, sha1, SHA1_DIGEST_LENGTH) != 0)
236 		err = got_error(GOT_ERR_PACKIDX_CSUM);
237 done:
238 	fclose(f);
239 	if (err)
240 		got_packidx_close(p);
241 	else
242 		*packidx = p;
243 	return err;
244 }
245 
246 void
247 got_packidx_close(struct got_packidx_v2_hdr *packidx)
248 {
249 	free(packidx->sorted_ids);
250 	free(packidx->offsets);
251 	free(packidx->crc32);
252 	free(packidx->large_offsets);
253 	free(packidx);
254 }
255 
256 static int
257 is_packidx_filename(const char *name, size_t len)
258 {
259 	if (len != GOT_PACKIDX_NAMELEN)
260 		return 0;
261 
262 	if (strncmp(name, GOT_PACK_PREFIX, strlen(GOT_PACK_PREFIX)) != 0)
263 		return 0;
264 
265 	if (strcmp(name + strlen(GOT_PACK_PREFIX) +
266 	    SHA1_DIGEST_STRING_LENGTH - 1, GOT_PACKIDX_SUFFIX) != 0)
267 		return 0;
268 
269 	return 1;
270 }
271 
272 static off_t
273 get_object_offset(struct got_packidx_v2_hdr *packidx, int idx)
274 {
275 	uint32_t totobj = betoh32(packidx->fanout_table[0xff]);
276 	uint32_t offset = betoh32(packidx->offsets[idx]);
277 	if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
278 		uint64_t loffset;
279 		idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
280 		if (idx < 0 || idx > totobj || packidx->large_offsets == NULL)
281 			return -1;
282 		loffset = betoh64(packidx->large_offsets[idx]);
283 		return (loffset > INT64_MAX ? -1 : (off_t)loffset);
284 	}
285 	return (off_t)(offset & GOT_PACKIDX_OFFSET_VAL_MASK);
286 }
287 
288 static int
289 get_object_idx(struct got_packidx_v2_hdr *packidx, struct got_object_id *id)
290 {
291 	u_int8_t id0 = id->sha1[0];
292 	uint32_t totobj = betoh32(packidx->fanout_table[0xff]);
293 	int i = 0;
294 
295 	if (id0 > 0)
296 		i = betoh32(packidx->fanout_table[id0 - 1]);
297 
298 	while (i < totobj) {
299 		struct got_object_id *oid = &packidx->sorted_ids[i];
300 		uint32_t offset;
301 		int cmp = got_object_id_cmp(id, oid);
302 
303 		if (cmp == 0)
304 			return i;
305 		i++;
306 	}
307 
308 	return -1;
309 }
310 
311 static const struct got_error *
312 search_packidx(struct got_packidx_v2_hdr **packidx, int *idx,
313     struct got_repository *repo, struct got_object_id *id)
314 {
315 	const struct got_error *err;
316 	char *path_packdir;
317 	DIR *packdir;
318 	struct dirent *dent;
319 	char *path_packidx;
320 
321 	path_packdir = got_repo_get_path_objects_pack(repo);
322 	if (path_packdir == NULL)
323 		return got_error(GOT_ERR_NO_MEM);
324 
325 	packdir = opendir(path_packdir);
326 	if (packdir == NULL) {
327 		err = got_error_from_errno();
328 		goto done;
329 	}
330 
331 	while ((dent = readdir(packdir)) != NULL) {
332 		if (!is_packidx_filename(dent->d_name, dent->d_namlen))
333 			continue;
334 
335 		if (asprintf(&path_packidx, "%s/%s", path_packdir,
336 		    dent->d_name) == -1) {
337 			err = got_error(GOT_ERR_NO_MEM);
338 			goto done;
339 		}
340 
341 		err = got_packidx_open(packidx, path_packidx);
342 		free(path_packidx);
343 		if (err)
344 			goto done;
345 
346 		*idx = get_object_idx(*packidx, id);
347 		if (*idx != -1) {
348 			err = NULL; /* found the object */
349 			goto done;
350 		}
351 
352 		got_packidx_close(*packidx);
353 		*packidx = NULL;
354 	}
355 
356 	err = got_error(GOT_ERR_NO_OBJ);
357 done:
358 	free(path_packdir);
359 	if (packdir && closedir(packdir) != 0 && err == 0)
360 		err = got_error_from_errno();
361 	return err;
362 }
363 
364 static const struct got_error *
365 get_packfile_path(char **path_packfile, struct got_repository *repo,
366     struct got_packidx_v2_hdr *packidx)
367 {
368 	char *path_packdir;
369 	char hex[SHA1_DIGEST_STRING_LENGTH];
370 	char *sha1str;
371 	char *path_packidx;
372 
373 	*path_packfile = NULL;
374 
375 	path_packdir = got_repo_get_path_objects_pack(repo);
376 	if (path_packdir == NULL)
377 		return got_error(GOT_ERR_NO_MEM);
378 
379 	sha1str = got_sha1_digest_to_str(packidx->trailer.packfile_sha1,
380 	    hex, sizeof(hex));
381 	if (sha1str == NULL)
382 		return got_error(GOT_ERR_PACKIDX_CSUM);
383 
384 	if (asprintf(path_packfile, "%s/%s%s%s", path_packdir,
385 	    GOT_PACK_PREFIX, sha1str, GOT_PACKFILE_SUFFIX) == -1) {
386 		*path_packfile = NULL;
387 		return got_error(GOT_ERR_NO_MEM);
388 	}
389 
390 	return NULL;
391 }
392 
393 const struct got_error *
394 read_packfile_hdr(FILE *f, struct got_packidx_v2_hdr *packidx)
395 {
396 	const struct got_error *err = NULL;
397 	uint32_t totobj = betoh32(packidx->fanout_table[0xff]);
398 	struct got_packfile_hdr hdr;
399 	size_t n;
400 
401 	n = fread(&hdr, sizeof(hdr), 1, f);
402 	if (n != 1)
403 		return got_ferror(f, GOT_ERR_BAD_PACKIDX);
404 
405 	if (betoh32(hdr.signature) != GOT_PACKFILE_SIGNATURE ||
406 	    betoh32(hdr.version) != GOT_PACKFILE_VERSION ||
407 	    betoh32(hdr.nobjects) != totobj)
408 		err = got_error(GOT_ERR_BAD_PACKFILE);
409 
410 	return err;
411 }
412 
413 static const struct got_error *
414 open_packfile(FILE **packfile, char **path_packfile,
415     struct got_repository *repo, struct got_packidx_v2_hdr *packidx)
416 {
417 	const struct got_error *err;
418 
419 	*packfile = NULL;
420 
421 	err = get_packfile_path(path_packfile, repo, packidx);
422 	if (err)
423 		return err;
424 
425 	*packfile = fopen(*path_packfile, "rb");
426 	if (*packfile == NULL) {
427 		err = got_error_from_errno();
428 		free(*path_packfile);
429 		return err;
430 	}
431 
432 	err = read_packfile_hdr(*packfile, packidx);
433 	if (err) {
434 		fclose(*packfile);
435 		*packfile = NULL;
436 	}
437 	return err;
438 }
439 
440 static const struct got_error *
441 parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len,
442     FILE *packfile)
443 {
444 	uint8_t t = 0;
445 	uint64_t s = 0;
446 	uint8_t sizeN;
447 	size_t n;
448 	int i = 0;
449 
450 	do {
451 		/* We do not support size values which don't fit in 64 bit. */
452 		if (i > 9)
453 			return got_error(GOT_ERR_NO_SPACE);
454 
455 		n = fread(&sizeN, sizeof(sizeN), 1, packfile);
456 		if (n != 1)
457 			return got_ferror(packfile, GOT_ERR_BAD_PACKIDX);
458 
459 		if (i == 0) {
460 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
461 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
462 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
463 		} else {
464 			size_t shift = 4 + 7 * (i - 1);
465 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
466 		}
467 		i++;
468 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
469 
470 	*type = t;
471 	*size = s;
472 	*len = i * sizeof(sizeN);
473 	return NULL;
474 }
475 
476 static const struct got_error *
477 open_plain_object(struct got_object **obj, const char *path_packfile,
478     struct got_object_id *id, uint8_t type, off_t offset, size_t size)
479 {
480 	*obj = calloc(1, sizeof(**obj));
481 	if (*obj == NULL)
482 		return got_error(GOT_ERR_NO_MEM);
483 
484 	(*obj)->path_packfile = strdup(path_packfile);
485 	if ((*obj)->path_packfile == NULL) {
486 		free(*obj);
487 		*obj = NULL;
488 		return got_error(GOT_ERR_NO_MEM);
489 	}
490 
491 	(*obj)->type = type;
492 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
493 	(*obj)->hdrlen = 0;
494 	(*obj)->size = size;
495 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
496 	(*obj)->pack_offset = offset;
497 
498 	return NULL;
499 }
500 
501 static const struct got_error *
502 parse_negative_offset(int64_t *offset, size_t *len, FILE *packfile)
503 {
504 	int64_t o = 0;
505 	uint8_t offN;
506 	size_t n;
507 	int i = 0;
508 
509 	do {
510 		/* We do not support offset values which don't fit in 64 bit. */
511 		if (i > 8)
512 			return got_error(GOT_ERR_NO_SPACE);
513 
514 		n = fread(&offN, sizeof(offN), 1, packfile);
515 		if (n != 1)
516 			return got_ferror(packfile, GOT_ERR_BAD_PACKIDX);
517 
518 		if (i == 0)
519 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
520 		else {
521 			o++;
522 			o <<= 7;
523 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
524 		}
525 		i++;
526 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
527 
528 	*offset = o;
529 	*len = i * sizeof(offN);
530 	return NULL;
531 }
532 
533 static const struct got_error *
534 parse_offset_delta(off_t *base_offset, FILE *packfile, off_t offset)
535 {
536 	const struct got_error *err;
537 	int64_t negoffset;
538 	size_t negofflen;
539 
540 	err = parse_negative_offset(&negoffset, &negofflen, packfile);
541 	if (err)
542 		return err;
543 
544 	/* Compute the base object's offset (must be in the same pack file). */
545 	*base_offset = (offset - negoffset);
546 	if (*base_offset <= 0)
547 		return got_error(GOT_ERR_BAD_PACKFILE);
548 
549 	return NULL;
550 }
551 
552 static const struct got_error *
553 resolve_delta_chain(struct got_delta_chain *, struct got_repository *,
554     FILE *, const char *, off_t, size_t, int, size_t);
555 
556 static const struct got_error *
557 add_delta(struct got_delta_chain *deltas, const char *path_packfile,
558     off_t delta_offset, size_t tslen, int delta_type, size_t delta_size,
559     size_t delta_data_offset)
560 {
561 	struct got_delta *delta;
562 
563 	delta = got_delta_open(path_packfile, delta_offset, tslen,
564 	    delta_type, delta_size, delta_data_offset);
565 	if (delta == NULL)
566 		return got_error(GOT_ERR_NO_MEM);
567 	/* delta is freed in got_object_close() */
568 	deltas->nentries++;
569 	SIMPLEQ_INSERT_HEAD(&deltas->entries, delta, entry);
570 	return NULL;
571 }
572 
573 static const struct got_error *
574 resolve_offset_delta(struct got_delta_chain *deltas,
575     struct got_repository *repo, FILE *packfile, const char *path_packfile,
576     off_t delta_offset,size_t tslen, int delta_type, size_t delta_size)
577 
578 {
579 	const struct got_error *err;
580 	off_t base_offset;
581 	uint8_t base_type;
582 	uint64_t base_size;
583 	size_t base_tslen;
584 	off_t delta_data_offset;
585 
586 	err = parse_offset_delta(&base_offset, packfile, delta_offset);
587 	if (err)
588 		return err;
589 
590 	delta_data_offset = ftello(packfile);
591 	if (delta_data_offset == -1)
592 		return got_error_from_errno();
593 
594 	err = add_delta(deltas, path_packfile, delta_offset, tslen,
595 	    delta_type, delta_size, delta_data_offset);
596 	if (err)
597 		return err;
598 
599 	/* An offset delta must be in the same packfile. */
600 	if (fseeko(packfile, base_offset, SEEK_SET) != 0)
601 		return got_error_from_errno();
602 
603 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
604 	    packfile);
605 	if (err)
606 		return err;
607 
608 	return resolve_delta_chain(deltas, repo, packfile, path_packfile,
609 	    base_offset, base_tslen, base_type, base_size);
610 }
611 
612 static const struct got_error *
613 resolve_ref_delta(struct got_delta_chain *deltas, struct got_repository *repo,
614     FILE *packfile, const char *path_packfile, off_t delta_offset,
615     size_t tslen, int delta_type, size_t delta_size)
616 {
617 	const struct got_error *err;
618 	struct got_object_id id;
619 	struct got_packidx_v2_hdr *packidx;
620 	int idx;
621 	off_t base_offset;
622 	uint8_t base_type;
623 	uint64_t base_size;
624 	size_t base_tslen;
625 	size_t n;
626 	FILE *base_packfile;
627 	char *path_base_packfile;
628 	off_t delta_data_offset;
629 
630 	n = fread(&id, sizeof(id), 1, packfile);
631 	if (n != 1)
632 		return got_ferror(packfile, GOT_ERR_IO);
633 
634 	delta_data_offset = ftello(packfile);
635 	if (delta_data_offset == -1)
636 		return got_error_from_errno();
637 
638 	err = add_delta(deltas, path_packfile, delta_offset, tslen,
639 	    delta_type, delta_size, delta_data_offset);
640 	if (err)
641 		return err;
642 
643 	err = search_packidx(&packidx, &idx, repo, &id);
644 	if (err)
645 		return err;
646 
647 	base_offset = get_object_offset(packidx, idx);
648 	if (base_offset == (uint64_t)-1) {
649 		got_packidx_close(packidx);
650 		return got_error(GOT_ERR_BAD_PACKIDX);
651 	}
652 
653 	err = open_packfile(&base_packfile, &path_base_packfile, repo, packidx);
654 	got_packidx_close(packidx);
655 	if (err)
656 		return err;
657 
658 	if (fseeko(base_packfile, base_offset, SEEK_SET) != 0) {
659 		err = got_error_from_errno();
660 		goto done;
661 	}
662 
663 	err = parse_object_type_and_size(&base_type, &base_size, &base_tslen,
664 	    base_packfile);
665 	if (err)
666 		goto done;
667 
668 	err = resolve_delta_chain(deltas, repo, base_packfile,
669 	    path_base_packfile, base_offset, base_tslen, base_type,
670 	    base_size);
671 done:
672 	free(path_base_packfile);
673 	if (base_packfile && fclose(base_packfile) == -1 && err == 0)
674 		err = got_error_from_errno();
675 	return err;
676 }
677 
678 static const struct got_error *
679 resolve_delta_chain(struct got_delta_chain *deltas, struct got_repository *repo,
680     FILE *packfile, const char *path_packfile, off_t delta_offset, size_t tslen,
681     int delta_type, size_t delta_size)
682 {
683 	const struct got_error *err = NULL;
684 
685 	switch (delta_type) {
686 	case GOT_OBJ_TYPE_COMMIT:
687 	case GOT_OBJ_TYPE_TREE:
688 	case GOT_OBJ_TYPE_BLOB:
689 	case GOT_OBJ_TYPE_TAG:
690 		/* Plain types are the final delta base. Recursion ends. */
691 		err = add_delta(deltas, path_packfile, delta_offset, tslen,
692 		    delta_type, delta_size, 0);
693 		break;
694 	case GOT_OBJ_TYPE_OFFSET_DELTA:
695 		err = resolve_offset_delta(deltas, repo, packfile,
696 		    path_packfile, delta_offset, tslen, delta_type,
697 		    delta_size);
698 		break;
699 	case GOT_OBJ_TYPE_REF_DELTA:
700 		err = resolve_ref_delta(deltas, repo, packfile,
701 		    path_packfile, delta_offset, tslen, delta_type,
702 		    delta_size);
703 		break;
704 	default:
705 		return got_error(GOT_ERR_NOT_IMPL);
706 	}
707 
708 	return err;
709 }
710 
711 static const struct got_error *
712 open_delta_object(struct got_object **obj, struct got_repository *repo,
713     struct got_packidx_v2_hdr *packidx, const char *path_packfile,
714     FILE *packfile, struct got_object_id *id, off_t offset, size_t tslen,
715     int delta_type, size_t delta_size)
716 {
717 	const struct got_error *err = NULL;
718 	struct got_object_id base_id;
719 	uint8_t base_type;
720 	int resolved_type;
721 	uint64_t base_size;
722 	size_t base_tslen;
723 
724 	*obj = calloc(1, sizeof(**obj));
725 	if (*obj == NULL)
726 		return got_error(GOT_ERR_NO_MEM);
727 
728 	(*obj)->flags = 0;
729 	(*obj)->hdrlen = 0;
730 	(*obj)->size = 0; /* Not yet known because deltas aren't combined. */
731 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
732 	(*obj)->pack_offset = offset + tslen;
733 
734 	(*obj)->path_packfile = strdup(path_packfile);
735 	if ((*obj)->path_packfile == NULL) {
736 		err = got_error(GOT_ERR_NO_MEM);
737 		goto done;
738 	}
739 	(*obj)->flags |= GOT_OBJ_FLAG_PACKED;
740 
741 	SIMPLEQ_INIT(&(*obj)->deltas.entries);
742 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
743 
744 	err = resolve_delta_chain(&(*obj)->deltas, repo, packfile,
745 	    path_packfile, offset, tslen, delta_type, delta_size);
746 	if (err)
747 		goto done;
748 
749 	err = got_delta_chain_get_base_type(&resolved_type, &(*obj)->deltas);
750 	if (err)
751 		goto done;
752 	(*obj)->type = resolved_type;
753 
754 done:
755 	if (err) {
756 		got_object_close(*obj);
757 		*obj = NULL;
758 	}
759 	return err;
760 }
761 
762 static const struct got_error *
763 open_packed_object(struct got_object **obj, struct got_repository *repo,
764     struct got_packidx_v2_hdr *packidx, int idx, struct got_object_id *id)
765 {
766 	const struct got_error *err = NULL;
767 	off_t offset;
768 	char *path_packfile;
769 	FILE *packfile;
770 	uint8_t type;
771 	uint64_t size;
772 	size_t tslen;
773 
774 	*obj = NULL;
775 
776 	offset = get_object_offset(packidx, idx);
777 	if (offset == (uint64_t)-1)
778 		return got_error(GOT_ERR_BAD_PACKIDX);
779 
780 	err = open_packfile(&packfile, &path_packfile, repo, packidx);
781 	if (err)
782 		return err;
783 
784 	if (fseeko(packfile, offset, SEEK_SET) != 0) {
785 		err = got_error_from_errno();
786 		goto done;
787 	}
788 
789 	err = parse_object_type_and_size(&type, &size, &tslen, packfile);
790 	if (err)
791 		goto done;
792 
793 	switch (type) {
794 	case GOT_OBJ_TYPE_COMMIT:
795 	case GOT_OBJ_TYPE_TREE:
796 	case GOT_OBJ_TYPE_BLOB:
797 	case GOT_OBJ_TYPE_TAG:
798 		err = open_plain_object(obj, path_packfile, id, type,
799 		    offset + tslen, size);
800 		break;
801 
802 	case GOT_OBJ_TYPE_OFFSET_DELTA:
803 	case GOT_OBJ_TYPE_REF_DELTA:
804 		err = open_delta_object(obj, repo, packidx, path_packfile,
805 		    packfile, id, offset, tslen, type, size);
806 		break;
807 
808 	default:
809 		err = got_error(GOT_ERR_NOT_IMPL);
810 		goto done;
811 	}
812 done:
813 	free(path_packfile);
814 	if (packfile && fclose(packfile) == -1 && err == 0)
815 		err = got_error_from_errno();
816 	return err;
817 }
818 
819 const struct got_error *
820 got_packfile_open_object(struct got_object **obj, struct got_object_id *id,
821     struct got_repository *repo)
822 {
823 	const struct got_error *err = NULL;
824 	struct got_packidx_v2_hdr *packidx = NULL;
825 	int idx;
826 
827 	err = search_packidx(&packidx, &idx, repo, id);
828 	if (err)
829 		return err;
830 
831 	err = open_packed_object(obj, repo, packidx, idx, id);
832 	got_packidx_close(packidx);
833 	return err;
834 }
835 
836 static const struct got_error *
837 dump_delta_chain(struct got_delta_chain *deltas, FILE *outfile)
838 {
839 	const struct got_error *err = NULL;
840 	struct got_delta *delta;
841 	FILE *base_file, *accum_file;
842 	int n = 0;
843 
844 	if (SIMPLEQ_EMPTY(&deltas->entries))
845 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
846 
847 	base_file = got_opentemp();
848 	if (base_file == NULL)
849 		return got_error_from_errno();
850 
851 	accum_file = got_opentemp();
852 	if (accum_file == NULL) {
853 		err = got_error_from_errno();
854 		fclose(base_file);
855 		return err;
856 	}
857 
858 	/* Deltas are ordered in ascending order. */
859 	SIMPLEQ_FOREACH(delta, &deltas->entries, entry) {
860 		uint8_t *delta_buf = NULL;
861 		size_t delta_len = 0;
862 		FILE *delta_file;
863 
864 		delta_file = fopen(delta->path_packfile, "rb");
865 		if (delta_file == NULL) {
866 			err = got_error_from_errno();
867 			goto done;
868 		}
869 
870 
871 		if (n == 0) {
872 			/* Plain object types are the delta base. */
873 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
874 			    delta->type != GOT_OBJ_TYPE_TREE &&
875 			    delta->type != GOT_OBJ_TYPE_BLOB &&
876 			    delta->type != GOT_OBJ_TYPE_TAG) {
877 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
878 				goto done;
879 			}
880 
881 			if (fseeko(delta_file, delta->offset + delta->tslen,
882 			    SEEK_SET) != 0) {
883 				fclose(delta_file);
884 				err = got_error_from_errno();
885 				goto done;
886 			}
887 			err = got_inflate_to_file(&delta_len, delta_file,
888 			    base_file);
889 			fclose(delta_file);
890 			if (err)
891 				goto done;
892 			n++;
893 			rewind(base_file);
894 			continue;
895 		}
896 
897 		if (fseeko(delta_file, delta->data_offset, SEEK_CUR) != 0) {
898 			fclose(delta_file);
899 			err = got_error_from_errno();
900 			goto done;
901 		}
902 
903 		/* Delta streams should always fit in memory. */
904 		err = got_inflate_to_mem(&delta_buf, &delta_len, delta_file);
905 		fclose(delta_file);
906 		if (err)
907 			goto done;
908 
909 		err = got_delta_apply(base_file, delta_buf, delta_len,
910 		    /* Final delta application writes to the output file. */
911 		    ++n < deltas->nentries ? accum_file : outfile);
912 		free(delta_buf);
913 		if (err)
914 			goto done;
915 
916 		if (n < deltas->nentries) {
917 			/* Accumulated delta becomes the new base. */
918 			FILE *tmp = accum_file;
919 			accum_file = base_file;
920 			base_file = tmp;
921 			rewind(base_file);
922 			rewind(accum_file);
923 		}
924 	}
925 
926 done:
927 	fclose(base_file);
928 	fclose(accum_file);
929 	rewind(outfile);
930 	return err;
931 }
932 
933 const struct got_error *
934 got_packfile_extract_object(FILE **f, struct got_object *obj,
935     struct got_repository *repo)
936 {
937 	const struct got_error *err = NULL;
938 	FILE *packfile = NULL;
939 
940 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
941 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
942 
943 	*f = got_opentemp();
944 	if (*f == NULL) {
945 		err = got_error(GOT_ERR_FILE_OPEN);
946 		goto done;
947 	}
948 
949 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
950 		packfile = fopen(obj->path_packfile, "rb");
951 		if (packfile == NULL) {
952 			err = got_error_from_errno();
953 			goto done;
954 		}
955 
956 		if (fseeko(packfile, obj->pack_offset, SEEK_SET) != 0) {
957 			err = got_error_from_errno();
958 			goto done;
959 		}
960 
961 		err = got_inflate_to_file(&obj->size, packfile, *f);
962 	} else
963 		err = dump_delta_chain(&obj->deltas, *f);
964 done:
965 	if (packfile)
966 		fclose(packfile);
967 	if (err && *f)
968 		fclose(*f);
969 	return err;
970 }