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Date:: Mon Oct 24 10:05:39 2022 UTC
Message:: close parent's end of imsg pipe before waiting for a child process to exit Prevents a dead-lock in 'tog log' where tog wants to exit (e.g. because the user pressed Ctrl-C) while a got-read-pack child process wants to send more commits. Closing the parent's pipe descriptor makes writes to the pipe fail in the child process. The child then unwinds via an ERR_EOF error and exits, instead of forever polling its end of the pipe in order to write more data. ok jamsek
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1 /*
2  * Copyright (c) 2018, 2019, 2020 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <sys/stat.h>
19 #include <sys/queue.h>
20 #include <sys/uio.h>
21 #include <sys/mman.h>
22 #include <sys/resource.h>
23 #include <sys/socket.h>
24 
25 #include <fcntl.h>
26 #include <errno.h>
27 #include <stdio.h>
28 #include <stdint.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <limits.h>
32 #include <sha1.h>
33 #include <endian.h>
34 #include <unistd.h>
35 #include <zlib.h>
36 #include <imsg.h>
37 
38 #include "got_error.h"
39 #include "got_object.h"
40 #include "got_path.h"
41 
42 #include "got_lib_sha1.h"
43 #include "got_lib_delta.h"
44 #include "got_lib_delta_cache.h"
45 #include "got_lib_inflate.h"
46 #include "got_lib_object.h"
47 #include "got_lib_object_parse.h"
48 #include "got_lib_privsep.h"
49 #include "got_lib_pack.h"
50 
51 #ifndef nitems
52 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
53 #endif
54 
55 #ifndef MIN
56 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
57 #endif
58 
59 static const struct got_error *
60 verify_fanout_table(uint32_t *fanout_table)
61 {
62 	int i;
63 
64 	for (i = 0; i < 0xff - 1; i++) {
65 		if (be32toh(fanout_table[i]) > be32toh(fanout_table[i + 1]))
66 			return got_error(GOT_ERR_BAD_PACKIDX);
67 	}
68 
69 	return NULL;
70 }
71 
72 const struct got_error *
73 got_packidx_init_hdr(struct got_packidx *p, int verify, off_t packfile_size)
74 {
75 	const struct got_error *err = NULL;
76 	struct got_packidx_v2_hdr *h;
77 	SHA1_CTX ctx;
78 	uint8_t sha1[SHA1_DIGEST_LENGTH];
79 	size_t nobj, len_fanout, len_ids, offset, remain;
80 	ssize_t n;
81 	int i;
82 
83 	SHA1Init(&ctx);
84 
85 	h = &p->hdr;
86 	offset = 0;
87 	remain = p->len;
88 
89 	if (remain < sizeof(*h->magic)) {
90 		err = got_error(GOT_ERR_BAD_PACKIDX);
91 		goto done;
92 	}
93 	if (p->map)
94 		h->magic = (uint32_t *)(p->map + offset);
95 	else {
96 		h->magic = malloc(sizeof(*h->magic));
97 		if (h->magic == NULL) {
98 			err = got_error_from_errno("malloc");
99 			goto done;
100 		}
101 		n = read(p->fd, h->magic, sizeof(*h->magic));
102 		if (n < 0) {
103 			err = got_error_from_errno("read");
104 			goto done;
105 		} else if (n != sizeof(*h->magic)) {
106 			err = got_error(GOT_ERR_BAD_PACKIDX);
107 			goto done;
108 		}
109 	}
110 	if (*h->magic != htobe32(GOT_PACKIDX_V2_MAGIC)) {
111 		err = got_error(GOT_ERR_BAD_PACKIDX);
112 		goto done;
113 	}
114 	offset += sizeof(*h->magic);
115 	remain -= sizeof(*h->magic);
116 
117 	if (verify)
118 		SHA1Update(&ctx, (uint8_t *)h->magic, sizeof(*h->magic));
119 
120 	if (remain < sizeof(*h->version)) {
121 		err = got_error(GOT_ERR_BAD_PACKIDX);
122 		goto done;
123 	}
124 	if (p->map)
125 		h->version = (uint32_t *)(p->map + offset);
126 	else {
127 		h->version = malloc(sizeof(*h->version));
128 		if (h->version == NULL) {
129 			err = got_error_from_errno("malloc");
130 			goto done;
131 		}
132 		n = read(p->fd, h->version, sizeof(*h->version));
133 		if (n < 0) {
134 			err = got_error_from_errno("read");
135 			goto done;
136 		} else if (n != sizeof(*h->version)) {
137 			err = got_error(GOT_ERR_BAD_PACKIDX);
138 			goto done;
139 		}
140 	}
141 	if (*h->version != htobe32(GOT_PACKIDX_VERSION)) {
142 		err = got_error(GOT_ERR_BAD_PACKIDX);
143 		goto done;
144 	}
145 	offset += sizeof(*h->version);
146 	remain -= sizeof(*h->version);
147 
148 	if (verify)
149 		SHA1Update(&ctx, (uint8_t *)h->version, sizeof(*h->version));
150 
151 	len_fanout =
152 	    sizeof(*h->fanout_table) * GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS;
153 	if (remain < len_fanout) {
154 		err = got_error(GOT_ERR_BAD_PACKIDX);
155 		goto done;
156 	}
157 	if (p->map)
158 		h->fanout_table = (uint32_t *)(p->map + offset);
159 	else {
160 		h->fanout_table = malloc(len_fanout);
161 		if (h->fanout_table == NULL) {
162 			err = got_error_from_errno("malloc");
163 			goto done;
164 		}
165 		n = read(p->fd, h->fanout_table, len_fanout);
166 		if (n < 0) {
167 			err = got_error_from_errno("read");
168 			goto done;
169 		} else if (n != len_fanout) {
170 			err = got_error(GOT_ERR_BAD_PACKIDX);
171 			goto done;
172 		}
173 	}
174 	err = verify_fanout_table(h->fanout_table);
175 	if (err)
176 		goto done;
177 	if (verify)
178 		SHA1Update(&ctx, (uint8_t *)h->fanout_table, len_fanout);
179 	offset += len_fanout;
180 	remain -= len_fanout;
181 
182 	nobj = be32toh(h->fanout_table[0xff]);
183 	len_ids = nobj * sizeof(*h->sorted_ids);
184 	if (len_ids <= nobj || len_ids > remain) {
185 		err = got_error(GOT_ERR_BAD_PACKIDX);
186 		goto done;
187 	}
188 	if (p->map)
189 		h->sorted_ids =
190 		    (struct got_packidx_object_id *)((uint8_t*)(p->map + offset));
191 	else {
192 		h->sorted_ids = malloc(len_ids);
193 		if (h->sorted_ids == NULL) {
194 			err = got_error(GOT_ERR_BAD_PACKIDX);
195 			goto done;
196 		}
197 		n = read(p->fd, h->sorted_ids, len_ids);
198 		if (n < 0)
199 			err = got_error_from_errno("read");
200 		else if (n != len_ids) {
201 			err = got_error(GOT_ERR_BAD_PACKIDX);
202 			goto done;
203 		}
204 	}
205 	if (verify)
206 		SHA1Update(&ctx, (uint8_t *)h->sorted_ids, len_ids);
207 	offset += len_ids;
208 	remain -= len_ids;
209 
210 	if (remain < nobj * sizeof(*h->crc32)) {
211 		err = got_error(GOT_ERR_BAD_PACKIDX);
212 		goto done;
213 	}
214 	if (p->map)
215 		h->crc32 = (uint32_t *)((uint8_t*)(p->map + offset));
216 	else {
217 		h->crc32 = malloc(nobj * sizeof(*h->crc32));
218 		if (h->crc32 == NULL) {
219 			err = got_error_from_errno("malloc");
220 			goto done;
221 		}
222 		n = read(p->fd, h->crc32, nobj * sizeof(*h->crc32));
223 		if (n < 0)
224 			err = got_error_from_errno("read");
225 		else if (n != nobj * sizeof(*h->crc32)) {
226 			err = got_error(GOT_ERR_BAD_PACKIDX);
227 			goto done;
228 		}
229 	}
230 	if (verify)
231 		SHA1Update(&ctx, (uint8_t *)h->crc32, nobj * sizeof(*h->crc32));
232 	remain -= nobj * sizeof(*h->crc32);
233 	offset += nobj * sizeof(*h->crc32);
234 
235 	if (remain < nobj * sizeof(*h->offsets)) {
236 		err = got_error(GOT_ERR_BAD_PACKIDX);
237 		goto done;
238 	}
239 	if (p->map)
240 		h->offsets = (uint32_t *)((uint8_t*)(p->map + offset));
241 	else {
242 		h->offsets = malloc(nobj * sizeof(*h->offsets));
243 		if (h->offsets == NULL) {
244 			err = got_error_from_errno("malloc");
245 			goto done;
246 		}
247 		n = read(p->fd, h->offsets, nobj * sizeof(*h->offsets));
248 		if (n < 0)
249 			err = got_error_from_errno("read");
250 		else if (n != nobj * sizeof(*h->offsets)) {
251 			err = got_error(GOT_ERR_BAD_PACKIDX);
252 			goto done;
253 		}
254 	}
255 	if (verify)
256 		SHA1Update(&ctx, (uint8_t *)h->offsets,
257 		    nobj * sizeof(*h->offsets));
258 	remain -= nobj * sizeof(*h->offsets);
259 	offset += nobj * sizeof(*h->offsets);
260 
261 	/* Large file offsets are contained only in files > 2GB. */
262 	if (verify || packfile_size > 0x7fffffff) {
263 		for (i = 0; i < nobj; i++) {
264 			uint32_t o = h->offsets[i];
265 			if (o & htobe32(GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX))
266 				p->nlargeobj++;
267 		}
268 	}
269 	if (p->nlargeobj == 0)
270 		goto checksum;
271 	else if (packfile_size <= 0x7fffffff) {
272 		err = got_error(GOT_ERR_BAD_PACKIDX);
273 		goto done;
274 	}
275 
276 	if (remain < p->nlargeobj * sizeof(*h->large_offsets)) {
277 		err = got_error(GOT_ERR_BAD_PACKIDX);
278 		goto done;
279 	}
280 	if (p->map)
281 		h->large_offsets = (uint64_t *)((uint8_t*)(p->map + offset));
282 	else {
283 		h->large_offsets = malloc(p->nlargeobj *
284 		    sizeof(*h->large_offsets));
285 		if (h->large_offsets == NULL) {
286 			err = got_error_from_errno("malloc");
287 			goto done;
288 		}
289 		n = read(p->fd, h->large_offsets,
290 		    p->nlargeobj * sizeof(*h->large_offsets));
291 		if (n < 0)
292 			err = got_error_from_errno("read");
293 		else if (n != p->nlargeobj * sizeof(*h->large_offsets)) {
294 			err = got_error(GOT_ERR_BAD_PACKIDX);
295 			goto done;
296 		}
297 	}
298 	if (verify)
299 		SHA1Update(&ctx, (uint8_t*)h->large_offsets,
300 		    p->nlargeobj * sizeof(*h->large_offsets));
301 	remain -= p->nlargeobj * sizeof(*h->large_offsets);
302 	offset += p->nlargeobj * sizeof(*h->large_offsets);
303 
304 checksum:
305 	if (remain < sizeof(*h->trailer)) {
306 		err = got_error(GOT_ERR_BAD_PACKIDX);
307 		goto done;
308 	}
309 	if (p->map)
310 		h->trailer =
311 		    (struct got_packidx_trailer *)((uint8_t*)(p->map + offset));
312 	else {
313 		h->trailer = malloc(sizeof(*h->trailer));
314 		if (h->trailer == NULL) {
315 			err = got_error_from_errno("malloc");
316 			goto done;
317 		}
318 		n = read(p->fd, h->trailer, sizeof(*h->trailer));
319 		if (n < 0)
320 			err = got_error_from_errno("read");
321 		else if (n != sizeof(*h->trailer)) {
322 			err = got_error(GOT_ERR_BAD_PACKIDX);
323 			goto done;
324 		}
325 	}
326 	if (verify) {
327 		SHA1Update(&ctx, h->trailer->packfile_sha1, SHA1_DIGEST_LENGTH);
328 		SHA1Final(sha1, &ctx);
329 		if (memcmp(h->trailer->packidx_sha1, sha1,
330 		    SHA1_DIGEST_LENGTH) != 0)
331 			err = got_error(GOT_ERR_PACKIDX_CSUM);
332 	}
333 done:
334 	return err;
335 }
336 
337 const struct got_error *
338 got_packidx_open(struct got_packidx **packidx,
339     int dir_fd, const char *relpath, int verify)
340 {
341 	const struct got_error *err = NULL;
342 	struct got_packidx *p = NULL;
343 	char *pack_relpath;
344 	struct stat idx_sb, pack_sb;
345 
346 	*packidx = NULL;
347 
348 	err = got_packidx_get_packfile_path(&pack_relpath, relpath);
349 	if (err)
350 		return err;
351 
352 	/*
353 	 * Ensure that a corresponding pack file exists.
354 	 * Some Git repositories have this problem. Git seems to ignore
355 	 * the existence of lonely pack index files but we do not.
356 	 */
357 	if (fstatat(dir_fd, pack_relpath, &pack_sb, 0) == -1) {
358 		if (errno == ENOENT) {
359 			err = got_error_fmt(GOT_ERR_LONELY_PACKIDX,
360 			    "%s", relpath);
361 		} else
362 			err = got_error_from_errno2("fstatat", pack_relpath);
363 		goto done;
364 	}
365 
366 	p = calloc(1, sizeof(*p));
367 	if (p == NULL) {
368 		err = got_error_from_errno("calloc");
369 		goto done;
370 	}
371 
372 	p->fd = openat(dir_fd, relpath, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
373 	if (p->fd == -1) {
374 		err = got_error_from_errno2("openat", relpath);
375 		goto done;
376 	}
377 
378 	if (fstat(p->fd, &idx_sb) != 0) {
379 		err = got_error_from_errno2("fstat", relpath);
380 		goto done;
381 	}
382 	p->len = idx_sb.st_size;
383 	if (p->len < sizeof(p->hdr)) {
384 		err = got_error(GOT_ERR_BAD_PACKIDX);
385 		goto done;
386 	}
387 
388 	p->path_packidx = strdup(relpath);
389 	if (p->path_packidx == NULL) {
390 		err = got_error_from_errno("strdup");
391 		goto done;
392 	}
393 
394 #ifndef GOT_PACK_NO_MMAP
395 	p->map = mmap(NULL, p->len, PROT_READ, MAP_PRIVATE, p->fd, 0);
396 	if (p->map == MAP_FAILED) {
397 		if (errno != ENOMEM) {
398 			err = got_error_from_errno("mmap");
399 			goto done;
400 		}
401 		p->map = NULL; /* fall back to read(2) */
402 	}
403 #endif
404 
405 	err = got_packidx_init_hdr(p, verify, pack_sb.st_size);
406 done:
407 	if (err) {
408 		if (p)
409 			got_packidx_close(p);
410 	} else
411 		*packidx = p;
412 	free(pack_relpath);
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("munmap");
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) == -1 && err == NULL)
436 		err = got_error_from_errno("close");
437 	free(packidx->sorted_offsets);
438 	free(packidx->sorted_large_offsets);
439 	free(packidx);
440 
441 	return err;
442 }
443 
444 const struct got_error *
445 got_packidx_get_packfile_path(char **path_packfile, const char *path_packidx)
446 {
447 	size_t size;
448 
449 	/* Packfile path contains ".pack" instead of ".idx", so add one byte. */
450 	size = strlen(path_packidx) + 2;
451 	if (size < GOT_PACKFILE_NAMELEN + 1)
452 		return got_error_path(path_packidx, GOT_ERR_BAD_PATH);
453 
454 	*path_packfile = malloc(size);
455 	if (*path_packfile == NULL)
456 		return got_error_from_errno("malloc");
457 
458 	/* Copy up to and excluding ".idx". */
459 	if (strlcpy(*path_packfile, path_packidx,
460 	    size - strlen(GOT_PACKIDX_SUFFIX) - 1) >= size)
461 		return got_error(GOT_ERR_NO_SPACE);
462 
463 	if (strlcat(*path_packfile, GOT_PACKFILE_SUFFIX, size) >= size)
464 		return got_error(GOT_ERR_NO_SPACE);
465 
466 	return NULL;
467 }
468 
469 off_t
470 got_packidx_get_object_offset(struct got_packidx *packidx, int idx)
471 {
472 	uint32_t offset = be32toh(packidx->hdr.offsets[idx]);
473 	if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
474 		uint64_t loffset;
475 		idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
476 		if (idx < 0 || idx >= packidx->nlargeobj ||
477 		    packidx->hdr.large_offsets == NULL)
478 			return -1;
479 		loffset = be64toh(packidx->hdr.large_offsets[idx]);
480 		return (loffset > INT64_MAX ? -1 : (off_t)loffset);
481 	}
482 	return (off_t)(offset & GOT_PACKIDX_OFFSET_VAL_MASK);
483 }
484 
485 int
486 got_packidx_get_object_idx(struct got_packidx *packidx,
487     struct got_object_id *id)
488 {
489 	u_int8_t id0 = id->sha1[0];
490 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
491 	int left = 0, right = totobj - 1;
492 
493 	if (id0 > 0)
494 		left = be32toh(packidx->hdr.fanout_table[id0 - 1]);
495 
496 	while (left <= right) {
497 		struct got_packidx_object_id *oid;
498 		int i, cmp;
499 
500 		i = ((left + right) / 2);
501 		oid = &packidx->hdr.sorted_ids[i];
502 		cmp = memcmp(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
503 		if (cmp == 0)
504 			return i;
505 		else if (cmp > 0)
506 			left = i + 1;
507 		else if (cmp < 0)
508 			right = i - 1;
509 	}
510 
511 	return -1;
512 }
513 
514 static int
515 offset_cmp(const void *pa, const void *pb)
516 {
517 	const struct got_pack_offset_index *a, *b;
518 
519 	a = (const struct got_pack_offset_index *)pa;
520 	b = (const struct got_pack_offset_index *)pb;
521 
522 	if (a->offset < b->offset)
523 		return -1;
524 	else if (a->offset > b->offset)
525 		return 1;
526 
527 	return 0;
528 }
529 
530 static int
531 large_offset_cmp(const void *pa, const void *pb)
532 {
533 	const struct got_pack_large_offset_index *a, *b;
534 
535 	a = (const struct got_pack_large_offset_index *)pa;
536 	b = (const struct got_pack_large_offset_index *)pb;
537 
538 	if (a->offset < b->offset)
539 		return -1;
540 	else if (a->offset > b->offset)
541 		return 1;
542 
543 	return 0;
544 }
545 
546 static const struct got_error *
547 build_offset_index(struct got_packidx *p)
548 {
549 	uint32_t nobj = be32toh(p->hdr.fanout_table[0xff]);
550 	unsigned int i, j, k;
551 
552 	p->sorted_offsets = calloc(nobj - p->nlargeobj,
553 	    sizeof(p->sorted_offsets[0]));
554 	if (p->sorted_offsets == NULL)
555 		return got_error_from_errno("calloc");
556 
557 	if (p->nlargeobj > 0) {
558 		p->sorted_large_offsets = calloc(p->nlargeobj,
559 		    sizeof(p->sorted_large_offsets[0]));
560 		if (p->sorted_large_offsets == NULL)
561 			return got_error_from_errno("calloc");
562 	}
563 
564 	j = 0;
565 	k = 0;
566 	for (i = 0; i < nobj; i++) {
567 		uint32_t offset = be32toh(p->hdr.offsets[i]);
568 		if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
569 			uint64_t loffset;
570 			uint32_t idx;
571 			idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
572 			if (idx >= p->nlargeobj ||
573 			    p->nlargeobj == 0 ||
574 			    p->hdr.large_offsets == NULL)
575 				return got_error(GOT_ERR_BAD_PACKIDX);
576 			loffset = be64toh(p->hdr.large_offsets[idx]);
577 			p->sorted_large_offsets[j].offset = loffset;
578 			p->sorted_large_offsets[j].idx = i;
579 			j++;
580 		} else {
581 			p->sorted_offsets[k].offset = offset;
582 			p->sorted_offsets[k].idx = i;
583 			k++;
584 		}
585 	}
586 	if (j != p->nlargeobj || k != nobj - p->nlargeobj)
587 		return got_error(GOT_ERR_BAD_PACKIDX);
588 
589 	qsort(p->sorted_offsets, nobj - p->nlargeobj,
590 	    sizeof(p->sorted_offsets[0]), offset_cmp);
591 
592 	if (p->sorted_large_offsets)
593 		qsort(p->sorted_large_offsets, p->nlargeobj,
594 		    sizeof(p->sorted_large_offsets[0]), large_offset_cmp);
595 
596 	return NULL;
597 }
598 
599 const struct got_error *
600 got_packidx_get_offset_idx(int *idx, struct got_packidx *packidx, off_t offset)
601 {
602 	const struct got_error *err;
603 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
604 	int i, left, right;
605 
606 	*idx = -1;
607 
608 	if (packidx->sorted_offsets == NULL) {
609 		err = build_offset_index(packidx);
610 		if (err)
611 			return err;
612 	}
613 
614 	if (offset >= 0x7fffffff) {
615 		uint64_t lo;
616 		left = 0, right = packidx->nlargeobj - 1;
617 		while (left <= right) {
618 			i = ((left + right) / 2);
619 			lo = packidx->sorted_large_offsets[i].offset;
620 			if (lo == offset) {
621 				*idx = packidx->sorted_large_offsets[i].idx;
622 				break;
623 			} else if (offset > lo)
624 				left = i + 1;
625 			else if (offset < lo)
626 				right = i - 1;
627 		}
628 	} else {
629 		uint32_t o;
630 		left = 0, right = totobj - packidx->nlargeobj - 1;
631 		while (left <= right) {
632 			i = ((left + right) / 2);
633 			o = packidx->sorted_offsets[i].offset;
634 			if (o == offset) {
635 				*idx = packidx->sorted_offsets[i].idx;
636 				break;
637 			} else if (offset > o)
638 				left = i + 1;
639 			else if (offset < o)
640 				right = i - 1;
641 		}
642 	}
643 
644 	return NULL;
645 }
646 
647 const struct got_error *
648 got_packidx_get_object_id(struct got_object_id *id,
649     struct got_packidx *packidx, int idx)
650 {
651 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
652 	struct got_packidx_object_id *oid;
653 
654 	if (idx < 0 || idx >= totobj)
655 		return got_error(GOT_ERR_NO_OBJ);
656 
657 	oid = &packidx->hdr.sorted_ids[idx];
658 	memcpy(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
659 	return NULL;
660 }
661 
662 const struct got_error *
663 got_packidx_match_id_str_prefix(struct got_object_id_queue *matched_ids,
664     struct got_packidx *packidx, const char *id_str_prefix)
665 {
666 	const struct got_error *err = NULL;
667 	u_int8_t id0;
668 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
669 	char hex[3];
670 	size_t prefix_len = strlen(id_str_prefix);
671 	struct got_packidx_object_id *oid;
672 	uint32_t i = 0;
673 
674 	STAILQ_INIT(matched_ids);
675 
676 	if (prefix_len < 2)
677 		return got_error_path(id_str_prefix, GOT_ERR_BAD_OBJ_ID_STR);
678 
679 	hex[0] = id_str_prefix[0];
680 	hex[1] = id_str_prefix[1];
681 	hex[2] = '\0';
682 	if (!got_parse_xdigit(&id0, hex))
683 		return got_error_path(id_str_prefix, GOT_ERR_BAD_OBJ_ID_STR);
684 
685 	if (id0 > 0)
686 		i = be32toh(packidx->hdr.fanout_table[id0 - 1]);
687 	oid = &packidx->hdr.sorted_ids[i];
688 	while (i < totobj && oid->sha1[0] == id0) {
689 		char id_str[SHA1_DIGEST_STRING_LENGTH];
690 		struct got_object_qid *qid;
691 		int cmp;
692 
693 		if (!got_sha1_digest_to_str(oid->sha1, id_str, sizeof(id_str)))
694 		        return got_error(GOT_ERR_NO_SPACE);
695 
696 		cmp = strncmp(id_str, id_str_prefix, prefix_len);
697 		if (cmp < 0) {
698 			oid = &packidx->hdr.sorted_ids[++i];
699 			continue;
700 		} else if (cmp > 0)
701 			break;
702 
703 		err = got_object_qid_alloc_partial(&qid);
704 		if (err)
705 			break;
706 		memcpy(qid->id.sha1, oid->sha1, SHA1_DIGEST_LENGTH);
707 		STAILQ_INSERT_TAIL(matched_ids, qid, entry);
708 
709 		oid = &packidx->hdr.sorted_ids[++i];
710 	}
711 
712 	if (err)
713 		got_object_id_queue_free(matched_ids);
714 	return err;
715 }
716 
717 static void
718 set_max_datasize(void)
719 {
720 	struct rlimit rl;
721 
722 	if (getrlimit(RLIMIT_DATA, &rl) != 0)
723 		return;
724 
725 	rl.rlim_cur = rl.rlim_max;
726 	setrlimit(RLIMIT_DATA, &rl);
727 }
728 
729 const struct got_error *
730 got_pack_start_privsep_child(struct got_pack *pack, struct got_packidx *packidx)
731 {
732 	const struct got_error *err = NULL;
733 	int imsg_fds[2];
734 	pid_t pid;
735 	struct imsgbuf *ibuf;
736 
737 	ibuf = calloc(1, sizeof(*ibuf));
738 	if (ibuf == NULL)
739 		return got_error_from_errno("calloc");
740 
741 	pack->privsep_child = calloc(1, sizeof(*pack->privsep_child));
742 	if (pack->privsep_child == NULL) {
743 		err = got_error_from_errno("calloc");
744 		free(ibuf);
745 		return err;
746 	}
747 	pack->child_has_tempfiles = 0;
748 	pack->child_has_delta_outfd = 0;
749 
750 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
751 		err = got_error_from_errno("socketpair");
752 		goto done;
753 	}
754 
755 	pid = fork();
756 	if (pid == -1) {
757 		err = got_error_from_errno("fork");
758 		goto done;
759 	} else if (pid == 0) {
760 		set_max_datasize();
761 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PACK,
762 		    pack->path_packfile);
763 		/* not reached */
764 	}
765 
766 	if (close(imsg_fds[1]) == -1)
767 		return got_error_from_errno("close");
768 	pack->privsep_child->imsg_fd = imsg_fds[0];
769 	pack->privsep_child->pid = pid;
770 	imsg_init(ibuf, imsg_fds[0]);
771 	pack->privsep_child->ibuf = ibuf;
772 
773 	err = got_privsep_init_pack_child(ibuf, pack, packidx);
774 	if (err) {
775 		const struct got_error *child_err;
776 		err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
777 		child_err = got_privsep_wait_for_child(
778 		    pack->privsep_child->pid);
779 		if (child_err && err == NULL)
780 			err = child_err;
781 	}
782 done:
783 	if (err) {
784 		free(ibuf);
785 		free(pack->privsep_child);
786 		pack->privsep_child = NULL;
787 	}
788 	return err;
789 }
790 
791 static const struct got_error *
792 pack_stop_privsep_child(struct got_pack *pack)
793 {
794 	const struct got_error *err = NULL, *close_err = NULL;
795 
796 	if (pack->privsep_child == NULL)
797 		return NULL;
798 
799 	err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
800 	if (err)
801 		return err;
802 	if (close(pack->privsep_child->imsg_fd) == -1)
803 		close_err = got_error_from_errno("close");
804 	err = got_privsep_wait_for_child(pack->privsep_child->pid);
805 	if (close_err && err == NULL)
806 		err = close_err;
807 	imsg_clear(pack->privsep_child->ibuf);
808 	free(pack->privsep_child->ibuf);
809 	free(pack->privsep_child);
810 	pack->privsep_child = NULL;
811 	return err;
812 }
813 
814 const struct got_error *
815 got_pack_close(struct got_pack *pack)
816 {
817 	const struct got_error *err = NULL;
818 
819 	err = pack_stop_privsep_child(pack);
820 	if (pack->map && munmap(pack->map, pack->filesize) == -1 && !err)
821 		err = got_error_from_errno("munmap");
822 	if (pack->fd != -1 && close(pack->fd) == -1 && err == NULL)
823 		err = got_error_from_errno("close");
824 	pack->fd = -1;
825 	free(pack->path_packfile);
826 	pack->path_packfile = NULL;
827 	pack->filesize = 0;
828 	if (pack->delta_cache) {
829 		got_delta_cache_free(pack->delta_cache);
830 		pack->delta_cache = NULL;
831 	}
832 
833 	/*
834 	 * Leave accumfd and basefd alone. They are managed by the
835 	 * repository layer and can be reused.
836 	 */
837 
838 	return err;
839 }
840 
841 const struct got_error *
842 got_pack_parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len,
843     struct got_pack *pack, off_t offset)
844 {
845 	uint8_t t = 0;
846 	uint64_t s = 0;
847 	uint8_t sizeN;
848 	size_t mapoff = 0;
849 	int i = 0;
850 
851 	*len = 0;
852 
853 	if (offset >= pack->filesize)
854 		return got_error(GOT_ERR_PACK_OFFSET);
855 
856 	if (pack->map) {
857 		mapoff = (size_t)offset;
858 	} else {
859 		if (lseek(pack->fd, offset, SEEK_SET) == -1)
860 			return got_error_from_errno("lseek");
861 	}
862 
863 	do {
864 		/* We do not support size values which don't fit in 64 bit. */
865 		if (i > 9)
866 			return got_error_fmt(GOT_ERR_OBJ_TOO_LARGE,
867 			    "packfile offset %llu", offset);
868 
869 		if (pack->map) {
870 			if (mapoff + sizeof(sizeN) >= pack->filesize)
871 				return got_error(GOT_ERR_BAD_PACKFILE);
872 			sizeN = *(pack->map + mapoff);
873 			mapoff += sizeof(sizeN);
874 		} else {
875 			ssize_t n = read(pack->fd, &sizeN, sizeof(sizeN));
876 			if (n < 0)
877 				return got_error_from_errno("read");
878 			if (n != sizeof(sizeN))
879 				return got_error(GOT_ERR_BAD_PACKFILE);
880 		}
881 		*len += sizeof(sizeN);
882 
883 		if (i == 0) {
884 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
885 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
886 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
887 		} else {
888 			size_t shift = 4 + 7 * (i - 1);
889 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
890 		}
891 		i++;
892 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
893 
894 	*type = t;
895 	*size = s;
896 	return NULL;
897 }
898 
899 static const struct got_error *
900 open_plain_object(struct got_object **obj, struct got_object_id *id,
901     uint8_t type, off_t offset, size_t size, int idx)
902 {
903 	*obj = calloc(1, sizeof(**obj));
904 	if (*obj == NULL)
905 		return got_error_from_errno("calloc");
906 
907 	(*obj)->type = type;
908 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
909 	(*obj)->pack_idx = idx;
910 	(*obj)->hdrlen = 0;
911 	(*obj)->size = size;
912 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
913 	(*obj)->pack_offset = offset;
914 
915 	return NULL;
916 }
917 
918 static const struct got_error *
919 parse_negative_offset(int64_t *offset, size_t *len, struct got_pack *pack,
920     off_t delta_offset)
921 {
922 	int64_t o = 0;
923 	uint8_t offN;
924 	int i = 0;
925 
926 	*offset = 0;
927 	*len = 0;
928 
929 	do {
930 		/* We do not support offset values which don't fit in 64 bit. */
931 		if (i > 8)
932 			return got_error(GOT_ERR_NO_SPACE);
933 
934 		if (pack->map) {
935 			size_t mapoff;
936 			mapoff = (size_t)delta_offset + *len;
937 			if (mapoff + sizeof(offN) >= pack->filesize)
938 				return got_error(GOT_ERR_PACK_OFFSET);
939 			offN = *(pack->map + mapoff);
940 		} else {
941 			ssize_t n;
942 			n = read(pack->fd, &offN, sizeof(offN));
943 			if (n < 0)
944 				return got_error_from_errno("read");
945 			if (n != sizeof(offN))
946 				return got_error(GOT_ERR_BAD_PACKFILE);
947 		}
948 		*len += sizeof(offN);
949 
950 		if (i == 0)
951 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
952 		else {
953 			o++;
954 			o <<= 7;
955 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
956 		}
957 		i++;
958 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
959 
960 	*offset = o;
961 	return NULL;
962 }
963 
964 const struct got_error *
965 got_pack_parse_offset_delta(off_t *base_offset, size_t *len,
966     struct got_pack *pack, off_t offset, int tslen)
967 {
968 	const struct got_error *err;
969 	int64_t negoffset;
970 	size_t negofflen;
971 
972 	*len = 0;
973 
974 	err = parse_negative_offset(&negoffset, &negofflen, pack,
975 	    offset + tslen);
976 	if (err)
977 		return err;
978 
979 	/* Compute the base object's offset (must be in the same pack file). */
980 	*base_offset = (offset - negoffset);
981 	if (*base_offset <= 0)
982 		return got_error(GOT_ERR_BAD_PACKFILE);
983 
984 	*len = negofflen;
985 	return NULL;
986 }
987 
988 static const struct got_error *
989 read_delta_data(uint8_t **delta_buf, size_t *delta_len,
990     size_t *delta_compressed_len, size_t delta_data_offset,
991     struct got_pack *pack)
992 {
993 	const struct got_error *err = NULL;
994 	size_t consumed = 0;
995 
996 	if (pack->map) {
997 		if (delta_data_offset >= pack->filesize)
998 			return got_error(GOT_ERR_PACK_OFFSET);
999 		err = got_inflate_to_mem_mmap(delta_buf, delta_len,
1000 		    &consumed, NULL, pack->map, delta_data_offset,
1001 		    pack->filesize - delta_data_offset);
1002 		if (err)
1003 			return err;
1004 	} else {
1005 		if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1)
1006 			return got_error_from_errno("lseek");
1007 		err = got_inflate_to_mem_fd(delta_buf, delta_len,
1008 		    &consumed, NULL, 0, pack->fd);
1009 		if (err)
1010 			return err;
1011 	}
1012 
1013 	if (delta_compressed_len)
1014 		*delta_compressed_len = consumed;
1015 
1016 	return NULL;
1017 }
1018 
1019 static const struct got_error *
1020 add_delta(struct got_delta_chain *deltas, off_t delta_offset, size_t tslen,
1021     int delta_type, size_t delta_size, size_t delta_data_offset)
1022 {
1023 	struct got_delta *delta;
1024 
1025 	delta = got_delta_open(delta_offset, tslen, delta_type, delta_size,
1026 	    delta_data_offset);
1027 	if (delta == NULL)
1028 		return got_error_from_errno("got_delta_open");
1029 	/* delta is freed in got_object_close() */
1030 	deltas->nentries++;
1031 	STAILQ_INSERT_HEAD(&deltas->entries, delta, entry);
1032 	return NULL;
1033 }
1034 
1035 static const struct got_error *
1036 resolve_offset_delta(struct got_delta_chain *deltas,
1037     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
1038     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
1039 
1040 {
1041 	const struct got_error *err;
1042 	off_t base_offset;
1043 	uint8_t base_type;
1044 	uint64_t base_size;
1045 	size_t base_tslen;
1046 	off_t delta_data_offset;
1047 	size_t consumed;
1048 
1049 	err = got_pack_parse_offset_delta(&base_offset, &consumed, pack,
1050 	    delta_offset, tslen);
1051 	if (err)
1052 		return err;
1053 
1054 	delta_data_offset = delta_offset + tslen + consumed;
1055 	if (delta_data_offset >= pack->filesize)
1056 		return got_error(GOT_ERR_PACK_OFFSET);
1057 
1058 	if (pack->map == NULL) {
1059 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
1060 		if (delta_data_offset == -1)
1061 			return got_error_from_errno("lseek");
1062 	}
1063 
1064 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
1065 	    delta_data_offset);
1066 	if (err)
1067 		return err;
1068 
1069 	/* An offset delta must be in the same packfile. */
1070 	if (base_offset >= pack->filesize)
1071 		return got_error(GOT_ERR_PACK_OFFSET);
1072 
1073 	err = got_pack_parse_object_type_and_size(&base_type, &base_size,
1074 	    &base_tslen, pack, base_offset);
1075 	if (err)
1076 		return err;
1077 
1078 	return got_pack_resolve_delta_chain(deltas, packidx, pack, base_offset,
1079 	    base_tslen, base_type, base_size, recursion - 1);
1080 }
1081 
1082 const struct got_error *
1083 got_pack_parse_ref_delta(struct got_object_id *id,
1084     struct got_pack *pack, off_t delta_offset, int tslen)
1085 {
1086 	if (pack->map) {
1087 		size_t mapoff = delta_offset + tslen;
1088 		if (mapoff + sizeof(*id) >= pack->filesize)
1089 			return got_error(GOT_ERR_PACK_OFFSET);
1090 		memcpy(id, pack->map + mapoff, sizeof(*id));
1091 	} else {
1092 		ssize_t n;
1093 		n = read(pack->fd, id, sizeof(*id));
1094 		if (n < 0)
1095 			return got_error_from_errno("read");
1096 		if (n != sizeof(*id))
1097 			return got_error(GOT_ERR_BAD_PACKFILE);
1098 	}
1099 
1100 	return NULL;
1101 }
1102 
1103 static const struct got_error *
1104 resolve_ref_delta(struct got_delta_chain *deltas, struct got_packidx *packidx,
1105     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
1106     size_t delta_size, unsigned int recursion)
1107 {
1108 	const struct got_error *err;
1109 	struct got_object_id id;
1110 	int idx;
1111 	off_t base_offset;
1112 	uint8_t base_type;
1113 	uint64_t base_size;
1114 	size_t base_tslen;
1115 	off_t delta_data_offset;
1116 
1117 	if (delta_offset + tslen >= pack->filesize)
1118 		return got_error(GOT_ERR_PACK_OFFSET);
1119 
1120 	err = got_pack_parse_ref_delta(&id, pack, delta_offset, tslen);
1121 	if (err)
1122 		return err;
1123 	if (pack->map) {
1124 		delta_data_offset = delta_offset + tslen + sizeof(id);
1125 	} else {
1126 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
1127 		if (delta_data_offset == -1)
1128 			return got_error_from_errno("lseek");
1129 	}
1130 
1131 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
1132 	    delta_data_offset);
1133 	if (err)
1134 		return err;
1135 
1136 	/* Delta base must be in the same pack file. */
1137 	idx = got_packidx_get_object_idx(packidx, &id);
1138 	if (idx == -1)
1139 		return got_error(GOT_ERR_NO_OBJ);
1140 
1141 	base_offset = got_packidx_get_object_offset(packidx, idx);
1142 	if (base_offset == -1)
1143 		return got_error(GOT_ERR_BAD_PACKIDX);
1144 
1145 	if (base_offset >= pack->filesize)
1146 		return got_error(GOT_ERR_PACK_OFFSET);
1147 
1148 	err = got_pack_parse_object_type_and_size(&base_type, &base_size,
1149 	    &base_tslen, pack, base_offset);
1150 	if (err)
1151 		return err;
1152 
1153 	return got_pack_resolve_delta_chain(deltas, packidx, pack, base_offset,
1154 	    base_tslen, base_type, base_size, recursion - 1);
1155 }
1156 
1157 const struct got_error *
1158 got_pack_resolve_delta_chain(struct got_delta_chain *deltas,
1159     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
1160     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
1161 {
1162 	const struct got_error *err = NULL;
1163 
1164 	if (--recursion == 0)
1165 		return got_error(GOT_ERR_RECURSION);
1166 
1167 	switch (delta_type) {
1168 	case GOT_OBJ_TYPE_COMMIT:
1169 	case GOT_OBJ_TYPE_TREE:
1170 	case GOT_OBJ_TYPE_BLOB:
1171 	case GOT_OBJ_TYPE_TAG:
1172 		/* Plain types are the final delta base. Recursion ends. */
1173 		err = add_delta(deltas, delta_offset, tslen, delta_type,
1174 		    delta_size, 0);
1175 		break;
1176 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1177 		err = resolve_offset_delta(deltas, packidx, pack,
1178 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
1179 		break;
1180 	case GOT_OBJ_TYPE_REF_DELTA:
1181 		err = resolve_ref_delta(deltas, packidx, pack,
1182 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
1183 		break;
1184 	default:
1185 		return got_error(GOT_ERR_OBJ_TYPE);
1186 	}
1187 
1188 	return err;
1189 }
1190 
1191 static const struct got_error *
1192 open_delta_object(struct got_object **obj, struct got_packidx *packidx,
1193     struct got_pack *pack, struct got_object_id *id, off_t offset,
1194     size_t tslen, int delta_type, size_t delta_size, int idx)
1195 {
1196 	const struct got_error *err = NULL;
1197 	int resolved_type;
1198 
1199 	*obj = calloc(1, sizeof(**obj));
1200 	if (*obj == NULL)
1201 		return got_error_from_errno("calloc");
1202 
1203 	(*obj)->flags = 0;
1204 	(*obj)->hdrlen = 0;
1205 	(*obj)->size = 0; /* Not known because deltas aren't applied yet. */
1206 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
1207 	(*obj)->pack_offset = offset + tslen;
1208 
1209 	STAILQ_INIT(&(*obj)->deltas.entries);
1210 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
1211 	(*obj)->flags |= GOT_OBJ_FLAG_PACKED;
1212 	(*obj)->pack_idx = idx;
1213 
1214 	err = got_pack_resolve_delta_chain(&(*obj)->deltas, packidx, pack,
1215 	    offset, tslen, delta_type, delta_size,
1216 	    GOT_DELTA_CHAIN_RECURSION_MAX);
1217 	if (err)
1218 		goto done;
1219 
1220 	err = got_delta_chain_get_base_type(&resolved_type, &(*obj)->deltas);
1221 	if (err)
1222 		goto done;
1223 	(*obj)->type = resolved_type;
1224 done:
1225 	if (err) {
1226 		got_object_close(*obj);
1227 		*obj = NULL;
1228 	}
1229 	return err;
1230 }
1231 
1232 const struct got_error *
1233 got_packfile_open_object(struct got_object **obj, struct got_pack *pack,
1234     struct got_packidx *packidx, int idx, struct got_object_id *id)
1235 {
1236 	const struct got_error *err = NULL;
1237 	off_t offset;
1238 	uint8_t type;
1239 	uint64_t size;
1240 	size_t tslen;
1241 
1242 	*obj = NULL;
1243 
1244 	offset = got_packidx_get_object_offset(packidx, idx);
1245 	if (offset == -1)
1246 		return got_error(GOT_ERR_BAD_PACKIDX);
1247 
1248 	err = got_pack_parse_object_type_and_size(&type, &size, &tslen,
1249 	    pack, offset);
1250 	if (err)
1251 		return err;
1252 
1253 	switch (type) {
1254 	case GOT_OBJ_TYPE_COMMIT:
1255 	case GOT_OBJ_TYPE_TREE:
1256 	case GOT_OBJ_TYPE_BLOB:
1257 	case GOT_OBJ_TYPE_TAG:
1258 		err = open_plain_object(obj, id, type, offset + tslen,
1259 		    size, idx);
1260 		break;
1261 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1262 	case GOT_OBJ_TYPE_REF_DELTA:
1263 		err = open_delta_object(obj, packidx, pack, id, offset,
1264 		    tslen, type, size, idx);
1265 		break;
1266 	default:
1267 		err = got_error(GOT_ERR_OBJ_TYPE);
1268 		break;
1269 	}
1270 
1271 	return err;
1272 }
1273 
1274 const struct got_error *
1275 got_pack_get_delta_chain_max_size(uint64_t *max_size,
1276     struct got_delta_chain *deltas, struct got_pack *pack)
1277 {
1278 	struct got_delta *delta;
1279 	uint64_t base_size = 0, result_size = 0;
1280 
1281 	*max_size = 0;
1282 	STAILQ_FOREACH(delta, &deltas->entries, entry) {
1283 		/* Plain object types are the delta base. */
1284 		if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1285 		    delta->type != GOT_OBJ_TYPE_TREE &&
1286 		    delta->type != GOT_OBJ_TYPE_BLOB &&
1287 		    delta->type != GOT_OBJ_TYPE_TAG) {
1288 			const struct got_error *err;
1289 			uint8_t *delta_buf = NULL;
1290 			size_t delta_len;
1291 			int cached = 1;
1292 
1293 			if (pack->delta_cache) {
1294 				got_delta_cache_get(&delta_buf, &delta_len,
1295 				    pack->delta_cache, delta->data_offset);
1296 			}
1297 			if (delta_buf == NULL) {
1298 				cached = 0;
1299 				err = read_delta_data(&delta_buf, &delta_len,
1300 				    NULL, delta->data_offset, pack);
1301 				if (err)
1302 					return err;
1303 			}
1304 			if (pack->delta_cache && !cached) {
1305 				err = got_delta_cache_add(pack->delta_cache,
1306 				    delta->data_offset, delta_buf, delta_len);
1307 				if (err == NULL)
1308 					cached = 1;
1309 				else if (err->code != GOT_ERR_NO_SPACE) {
1310 					free(delta_buf);
1311 					return err;
1312 				}
1313 			}
1314 			err = got_delta_get_sizes(&base_size, &result_size,
1315 			    delta_buf, delta_len);
1316 			if (!cached)
1317 				free(delta_buf);
1318 			if (err)
1319 				return err;
1320 		} else
1321 			base_size = delta->size;
1322 		if (base_size > *max_size)
1323 			*max_size = base_size;
1324 		if (result_size > *max_size)
1325 			*max_size = result_size;
1326 	}
1327 
1328 	return NULL;
1329 }
1330 
1331 const struct got_error *
1332 got_pack_get_max_delta_object_size(uint64_t *size, struct got_object *obj,
1333     struct got_pack *pack)
1334 {
1335 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0)
1336 		return got_error(GOT_ERR_OBJ_TYPE);
1337 
1338 	return got_pack_get_delta_chain_max_size(size, &obj->deltas, pack);
1339 }
1340 
1341 const struct got_error *
1342 got_pack_dump_delta_chain_to_file(size_t *result_size,
1343     struct got_delta_chain *deltas, struct got_pack *pack, FILE *outfile,
1344     FILE *base_file, FILE *accum_file)
1345 {
1346 	const struct got_error *err = NULL;
1347 	struct got_delta *delta;
1348 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1349 	size_t base_bufsz = 0, accum_bufsz = 0, accum_size = 0, delta_len;
1350 	/* We process small enough files entirely in memory for speed. */
1351 	const size_t max_bufsize = GOT_DELTA_RESULT_SIZE_CACHED_MAX;
1352 	uint64_t max_size = 0;
1353 	int n = 0;
1354 
1355 	*result_size = 0;
1356 
1357 	if (STAILQ_EMPTY(&deltas->entries))
1358 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1359 
1360 	if (fseeko(base_file, 0L, SEEK_SET) == -1)
1361 		return got_error_from_errno("fseeko");
1362 	if (fseeko(accum_file, 0L, SEEK_SET) == -1)
1363 		return got_error_from_errno("fseeko");
1364 
1365 	/* Deltas are ordered in ascending order. */
1366 	STAILQ_FOREACH(delta, &deltas->entries, entry) {
1367 		uint8_t *delta_buf = NULL;
1368 		uint64_t base_size, result_size = 0;
1369 		int cached = 1;
1370 		if (n == 0) {
1371 			size_t mapoff;
1372 			off_t delta_data_offset;
1373 
1374 			/* Plain object types are the delta base. */
1375 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1376 			    delta->type != GOT_OBJ_TYPE_TREE &&
1377 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1378 			    delta->type != GOT_OBJ_TYPE_TAG) {
1379 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1380 				goto done;
1381 			}
1382 
1383 			delta_data_offset = delta->offset + delta->tslen;
1384 			if (delta_data_offset >= pack->filesize) {
1385 				err = got_error(GOT_ERR_PACK_OFFSET);
1386 				goto done;
1387 			}
1388 			if (pack->map == NULL) {
1389 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1390 				    == -1) {
1391 					err = got_error_from_errno("lseek");
1392 					goto done;
1393 				}
1394 			}
1395 			if (delta->size > max_size)
1396 				max_size = delta->size;
1397 			if (max_size > max_bufsize) {
1398 				if (pack->map) {
1399 					mapoff = (size_t)delta_data_offset;
1400 					err = got_inflate_to_file_mmap(
1401 					    &base_bufsz, NULL, NULL, pack->map,
1402 					    mapoff, pack->filesize - mapoff,
1403 					    base_file);
1404 				} else
1405 					err = got_inflate_to_file_fd(
1406 					    &base_bufsz, NULL, NULL, pack->fd,
1407 					    base_file);
1408 			} else {
1409 				accum_buf = malloc(max_size);
1410 				if (accum_buf == NULL) {
1411 					err = got_error_from_errno("malloc");
1412 					goto done;
1413 				}
1414 				accum_bufsz = max_size;
1415 				if (pack->map) {
1416 					mapoff = (size_t)delta_data_offset;
1417 					err = got_inflate_to_mem_mmap(&base_buf,
1418 					    &base_bufsz, NULL, NULL,
1419 					    pack->map, mapoff,
1420 					    pack->filesize - mapoff);
1421 				} else
1422 					err = got_inflate_to_mem_fd(&base_buf,
1423 					    &base_bufsz, NULL, NULL, max_size,
1424 					    pack->fd);
1425 			}
1426 			if (err)
1427 				goto done;
1428 			n++;
1429 			if (base_buf == NULL)
1430 				rewind(base_file);
1431 			continue;
1432 		}
1433 
1434 		if (pack->delta_cache) {
1435 			got_delta_cache_get(&delta_buf, &delta_len,
1436 			    pack->delta_cache, delta->data_offset);
1437 		}
1438 		if (delta_buf == NULL) {
1439 			cached = 0;
1440 			err = read_delta_data(&delta_buf, &delta_len, NULL,
1441 			    delta->data_offset, pack);
1442 			if (err)
1443 				goto done;
1444 		}
1445 		if (pack->delta_cache && !cached) {
1446 			err = got_delta_cache_add(pack->delta_cache,
1447 			    delta->data_offset, delta_buf, delta_len);
1448 			if (err == NULL)
1449 				cached = 1;
1450 			else if (err->code != GOT_ERR_NO_SPACE) {
1451 				free(delta_buf);
1452 				goto done;
1453 			}
1454 		}
1455 
1456 		err = got_delta_get_sizes(&base_size, &result_size,
1457 		    delta_buf, delta_len);
1458 		if (err)
1459 			goto done;
1460 		if (base_size > max_size)
1461 			max_size = base_size;
1462 		if (result_size > max_size)
1463 			max_size = result_size;
1464 
1465 		if (base_buf && max_size > max_bufsize) {
1466 			/* Switch from buffers to temporary files. */
1467 			size_t w = fwrite(base_buf, 1, base_bufsz,
1468 			    base_file);
1469 			if (w != base_bufsz) {
1470 				err = got_ferror(outfile, GOT_ERR_IO);
1471 				goto done;
1472 			}
1473 			free(base_buf);
1474 			base_buf = NULL;
1475 			free(accum_buf);
1476 			accum_buf = NULL;
1477 		}
1478 
1479 		if (base_buf && max_size > base_bufsz) {
1480 			uint8_t *p = realloc(base_buf, max_size);
1481 			if (p == NULL) {
1482 				err = got_error_from_errno("realloc");
1483 				goto done;
1484 			}
1485 			base_buf = p;
1486 			base_bufsz = max_size;
1487 		}
1488 
1489 		if (accum_buf && max_size > accum_bufsz) {
1490 			uint8_t *p = realloc(accum_buf, max_size);
1491 			if (p == NULL) {
1492 				err = got_error_from_errno("realloc");
1493 				goto done;
1494 			}
1495 			accum_buf = p;
1496 			accum_bufsz = max_size;
1497 		}
1498 
1499 		if (base_buf) {
1500 			err = got_delta_apply_in_mem(base_buf, base_bufsz,
1501 			    delta_buf, delta_len, accum_buf,
1502 			    &accum_size, max_size);
1503 			n++;
1504 		} else {
1505 			err = got_delta_apply(base_file, delta_buf,
1506 			    delta_len,
1507 			    /* Final delta application writes to output file. */
1508 			    ++n < deltas->nentries ? accum_file : outfile,
1509 			    &accum_size);
1510 		}
1511 		if (!cached)
1512 			free(delta_buf);
1513 		if (err)
1514 			goto done;
1515 
1516 		if (n < deltas->nentries) {
1517 			/* Accumulated delta becomes the new base. */
1518 			if (base_buf) {
1519 				uint8_t *tmp = accum_buf;
1520 				size_t tmp_size = accum_bufsz;
1521 				accum_buf = base_buf;
1522 				accum_bufsz = base_bufsz;
1523 				base_buf = tmp;
1524 				base_bufsz = tmp_size;
1525 			} else {
1526 				FILE *tmp = accum_file;
1527 				accum_file = base_file;
1528 				base_file = tmp;
1529 				rewind(base_file);
1530 				rewind(accum_file);
1531 			}
1532 		}
1533 	}
1534 
1535 done:
1536 	free(base_buf);
1537 	if (accum_buf) {
1538 		size_t len = fwrite(accum_buf, 1, accum_size, outfile);
1539 		free(accum_buf);
1540 		if (len != accum_size)
1541 			err = got_ferror(outfile, GOT_ERR_IO);
1542 	}
1543 	rewind(outfile);
1544 	if (err == NULL)
1545 		*result_size = accum_size;
1546 	return err;
1547 }
1548 
1549 const struct got_error *
1550 got_pack_dump_delta_chain_to_mem(uint8_t **outbuf, size_t *outlen,
1551     struct got_delta_chain *deltas, struct got_pack *pack)
1552 {
1553 	const struct got_error *err = NULL;
1554 	struct got_delta *delta;
1555 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1556 	size_t base_bufsz = 0, accum_bufsz = 0, accum_size = 0, delta_len;
1557 	uint64_t max_size = 0;
1558 	int n = 0;
1559 
1560 	*outbuf = NULL;
1561 	*outlen = 0;
1562 
1563 	if (STAILQ_EMPTY(&deltas->entries))
1564 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1565 
1566 	/* Deltas are ordered in ascending order. */
1567 	STAILQ_FOREACH(delta, &deltas->entries, entry) {
1568 		uint8_t *delta_buf = NULL;
1569 		uint64_t base_size, result_size = 0;
1570 		int cached = 1;
1571 		if (n == 0) {
1572 			size_t delta_data_offset;
1573 
1574 			/* Plain object types are the delta base. */
1575 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1576 			    delta->type != GOT_OBJ_TYPE_TREE &&
1577 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1578 			    delta->type != GOT_OBJ_TYPE_TAG) {
1579 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1580 				goto done;
1581 			}
1582 
1583 			delta_data_offset = delta->offset + delta->tslen;
1584 			if (delta_data_offset >= pack->filesize) {
1585 				err = got_error(GOT_ERR_PACK_OFFSET);
1586 				goto done;
1587 			}
1588 
1589 			if (delta->size > max_size)
1590 				max_size = delta->size;
1591 
1592 			if (pack->map) {
1593 				size_t mapoff = (size_t)delta_data_offset;
1594 				err = got_inflate_to_mem_mmap(&base_buf,
1595 				    &base_bufsz, NULL, NULL, pack->map,
1596 				    mapoff, pack->filesize - mapoff);
1597 			} else {
1598 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1599 				    == -1) {
1600 					err = got_error_from_errno("lseek");
1601 					goto done;
1602 				}
1603 				err = got_inflate_to_mem_fd(&base_buf,
1604 				    &base_bufsz, NULL, NULL, max_size,
1605 				    pack->fd);
1606 			}
1607 			if (err)
1608 				goto done;
1609 			n++;
1610 			continue;
1611 		}
1612 
1613 		if (pack->delta_cache) {
1614 			got_delta_cache_get(&delta_buf, &delta_len,
1615 			    pack->delta_cache, delta->data_offset);
1616 		}
1617 		if (delta_buf == NULL) {
1618 			cached = 0;
1619 			err = read_delta_data(&delta_buf, &delta_len, NULL,
1620 			    delta->data_offset, pack);
1621 			if (err)
1622 				goto done;
1623 		}
1624 		if (pack->delta_cache && !cached) {
1625 			err = got_delta_cache_add(pack->delta_cache,
1626 			    delta->data_offset, delta_buf, delta_len);
1627 			if (err == NULL)
1628 				cached = 1;
1629 			else if (err->code != GOT_ERR_NO_SPACE) {
1630 				free(delta_buf);
1631 				goto done;
1632 			}
1633 		}
1634 
1635 		err = got_delta_get_sizes(&base_size, &result_size,
1636 		    delta_buf, delta_len);
1637 		if (err)
1638 			goto done;
1639 		if (base_size > max_size)
1640 			max_size = base_size;
1641 		if (result_size > max_size)
1642 			max_size = result_size;
1643 
1644 		if (max_size > base_bufsz) {
1645 			uint8_t *p = realloc(base_buf, max_size);
1646 			if (p == NULL) {
1647 				err = got_error_from_errno("realloc");
1648 				goto done;
1649 			}
1650 			base_buf = p;
1651 			base_bufsz = max_size;
1652 		}
1653 
1654 		if (max_size > accum_bufsz) {
1655 			uint8_t *p = realloc(accum_buf, max_size);
1656 			if (p == NULL) {
1657 				err = got_error_from_errno("realloc");
1658 				goto done;
1659 			}
1660 			accum_buf = p;
1661 			accum_bufsz = max_size;
1662 		}
1663 
1664 		err = got_delta_apply_in_mem(base_buf, base_bufsz,
1665 		    delta_buf, delta_len, accum_buf,
1666 		    &accum_size, max_size);
1667 		if (!cached)
1668 			free(delta_buf);
1669 		n++;
1670 		if (err)
1671 			goto done;
1672 
1673 		if (n < deltas->nentries) {
1674 			/* Accumulated delta becomes the new base. */
1675 			uint8_t *tmp = accum_buf;
1676 			size_t tmp_size = accum_bufsz;
1677 			accum_buf = base_buf;
1678 			accum_bufsz = base_bufsz;
1679 			base_buf = tmp;
1680 			base_bufsz = tmp_size;
1681 		}
1682 	}
1683 
1684 done:
1685 	free(base_buf);
1686 	if (err) {
1687 		free(accum_buf);
1688 		*outbuf = NULL;
1689 		*outlen = 0;
1690 	} else {
1691 		*outbuf = accum_buf;
1692 		*outlen = accum_size;
1693 	}
1694 	return err;
1695 }
1696 
1697 const struct got_error *
1698 got_packfile_extract_object(struct got_pack *pack, struct got_object *obj,
1699     FILE *outfile, FILE *base_file, FILE *accum_file)
1700 {
1701 	const struct got_error *err = NULL;
1702 
1703 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1704 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1705 
1706 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1707 		if (obj->pack_offset >= pack->filesize)
1708 			return got_error(GOT_ERR_PACK_OFFSET);
1709 
1710 		if (pack->map) {
1711 			size_t mapoff = (size_t)obj->pack_offset;
1712 			err = got_inflate_to_file_mmap(&obj->size, NULL, NULL,
1713 			    pack->map, mapoff, pack->filesize - mapoff,
1714 			    outfile);
1715 		} else {
1716 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1717 				return got_error_from_errno("lseek");
1718 			err = got_inflate_to_file_fd(&obj->size, NULL, NULL,
1719 			    pack->fd, outfile);
1720 		}
1721 	} else
1722 		err = got_pack_dump_delta_chain_to_file(&obj->size,
1723 		    &obj->deltas, pack, outfile, base_file, accum_file);
1724 
1725 	return err;
1726 }
1727 
1728 const struct got_error *
1729 got_packfile_extract_object_to_mem(uint8_t **buf, size_t *len,
1730     struct got_object *obj, struct got_pack *pack)
1731 {
1732 	const struct got_error *err = NULL;
1733 
1734 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1735 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1736 
1737 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1738 		if (obj->pack_offset >= pack->filesize)
1739 			return got_error(GOT_ERR_PACK_OFFSET);
1740 		if (pack->map) {
1741 			size_t mapoff = (size_t)obj->pack_offset;
1742 			err = got_inflate_to_mem_mmap(buf, len, NULL, NULL,
1743 			    pack->map, mapoff, pack->filesize - mapoff);
1744 		} else {
1745 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1746 				return got_error_from_errno("lseek");
1747 			err = got_inflate_to_mem_fd(buf, len, NULL, NULL,
1748 			    obj->size, pack->fd);
1749 		}
1750 	} else
1751 		err = got_pack_dump_delta_chain_to_mem(buf, len, &obj->deltas,
1752 		    pack);
1753 
1754 	return err;
1755 }
1756 
1757 static const struct got_error *
1758 read_raw_delta_data(uint8_t **delta_buf, size_t *delta_len,
1759     size_t *delta_len_compressed, uint64_t *base_size, uint64_t *result_size,
1760     off_t delta_data_offset, struct got_pack *pack, struct got_packidx *packidx)
1761 {
1762 	const struct got_error *err = NULL;
1763 
1764 	/* Validate decompression and obtain the decompressed size. */
1765 	err = read_delta_data(delta_buf, delta_len, delta_len_compressed,
1766 	    delta_data_offset, pack);
1767 	if (err)
1768 		return err;
1769 
1770 	/* Read delta base/result sizes from head of delta stream. */
1771 	err = got_delta_get_sizes(base_size, result_size,
1772 	    *delta_buf, *delta_len);
1773 	if (err)
1774 		goto done;
1775 
1776 	/* Discard decompressed delta and read it again in compressed form. */
1777 	free(*delta_buf);
1778 	*delta_buf = malloc(*delta_len_compressed);
1779 	if (*delta_buf == NULL) {
1780 		err = got_error_from_errno("malloc");
1781 		goto done;
1782 	}
1783 	if (pack->map) {
1784 		if (delta_data_offset >= pack->filesize)
1785 			err = got_error(GOT_ERR_PACK_OFFSET);
1786 		memcpy(*delta_buf, pack->map + delta_data_offset,
1787 		    *delta_len_compressed);
1788 	} else {
1789 		ssize_t n;
1790 		if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1) {
1791 			err = got_error_from_errno("lseek");
1792 			goto done;
1793 		}
1794 		n = read(pack->fd, *delta_buf, *delta_len_compressed);
1795 		if (n < 0) {
1796 			err = got_error_from_errno("read");
1797 			goto done;
1798 		} else if (n != *delta_len_compressed) {
1799 			err = got_error(GOT_ERR_IO);
1800 			goto done;
1801 		}
1802 	}
1803 done:
1804 	if (err) {
1805 		free(*delta_buf);
1806 		*delta_buf = NULL;
1807 		*delta_len = 0;
1808 		*delta_len_compressed = 0;
1809 		*base_size = 0;
1810 		*result_size = 0;
1811 	}
1812 	return err;
1813 }
1814 
1815 const struct got_error *
1816 got_packfile_extract_raw_delta(uint8_t **delta_buf, size_t *delta_size,
1817     size_t *delta_compressed_size, off_t *delta_offset, off_t *base_offset,
1818     struct got_object_id *base_id, uint64_t *base_size, uint64_t *result_size,
1819     struct got_pack *pack, struct got_packidx *packidx, int idx)
1820 {
1821 	const struct got_error *err = NULL;
1822 	off_t offset;
1823 	uint8_t type;
1824 	uint64_t size;
1825 	size_t tslen, delta_hdrlen;
1826 	off_t delta_data_offset;
1827 
1828 	*delta_buf = NULL;
1829 	*delta_size = 0;
1830 	*delta_compressed_size = 0;
1831 	*delta_offset = 0;
1832 	*base_offset = 0;
1833 	*base_size = 0;
1834 	*result_size = 0;
1835 
1836 	offset = got_packidx_get_object_offset(packidx, idx);
1837 	if (offset == -1)
1838 		return got_error(GOT_ERR_BAD_PACKIDX);
1839 
1840 	if (offset >= pack->filesize)
1841 		return got_error(GOT_ERR_PACK_OFFSET);
1842 
1843 	err = got_pack_parse_object_type_and_size(&type, &size, &tslen,
1844 	    pack, offset);
1845 	if (err)
1846 		return err;
1847 
1848 	if (tslen + size < tslen || offset + size < size ||
1849 	    tslen + offset < tslen)
1850 		return got_error(GOT_ERR_PACK_OFFSET);
1851 
1852 	switch (type) {
1853 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1854 		err = got_pack_parse_offset_delta(base_offset, &delta_hdrlen,
1855 		    pack, offset, tslen);
1856 		if (err)
1857 			return err;
1858 		break;
1859 	case GOT_OBJ_TYPE_REF_DELTA:
1860 		err = got_pack_parse_ref_delta(base_id, pack, offset, tslen);
1861 		if (err)
1862 			return err;
1863 		delta_hdrlen = SHA1_DIGEST_LENGTH;
1864 		break;
1865 	default:
1866 		return got_error_fmt(GOT_ERR_OBJ_TYPE,
1867 		    "non-delta object type %d found at offset %lld",
1868 		    type, (long long)offset);
1869 	}
1870 
1871 	if (tslen + delta_hdrlen < delta_hdrlen ||
1872 	    offset + delta_hdrlen < delta_hdrlen)
1873 		return got_error(GOT_ERR_BAD_DELTA);
1874 
1875 	delta_data_offset = offset + tslen + delta_hdrlen;
1876 	err = read_raw_delta_data(delta_buf, delta_size, delta_compressed_size,
1877 	    base_size, result_size, delta_data_offset, pack, packidx);
1878 	if (err)
1879 		return err;
1880 
1881 	if (*delta_size != size) {
1882 		err = got_error(GOT_ERR_BAD_DELTA);
1883 		goto done;
1884 	}
1885 
1886 	*delta_offset = offset;
1887 done:
1888 	if (err) {
1889 		free(*delta_buf);
1890 		*delta_buf = NULL;
1891 		*delta_size = 0;
1892 		*delta_compressed_size = 0;
1893 		*delta_offset = 0;
1894 		*base_offset = 0;
1895 		*base_size = 0;
1896 		*result_size = 0;
1897 	}
1898 	return err;
1899 }