op public repos

Blob

Date:: Tue Mar 24 15:24:08 2020 UTC
Message:: make got-index-pack check the expected pack checksum passed from main process
Actions:: History | Blame | Raw File
1 /*
2  * Copyright (c) 2019 Ori Bernstein <ori@openbsd.org>
3  * Copyright (c) 2020 Stefan Sperling <stsp@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include <sys/queue.h>
19 #include <sys/stat.h>
20 #include <sys/syslimits.h>
21 #include <sys/time.h>
22 #include <sys/types.h>
23 #include <sys/uio.h>
24 #include <sys/mman.h>
25 
26 #include <stdint.h>
27 #include <errno.h>
28 #include <imsg.h>
29 #include <limits.h>
30 #include <signal.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <ctype.h>
35 #include <sha1.h>
36 #include <fcntl.h>
37 #include <zlib.h>
38 #include <err.h>
39 #include <assert.h>
40 #include <dirent.h>
41 
42 #include "got_error.h"
43 #include "got_object.h"
44 
45 #include "got_lib_sha1.h"
46 #include "got_lib_delta.h"
47 #include "got_lib_inflate.h"
48 #include "got_lib_object.h"
49 #include "got_lib_object_parse.h"
50 #include "got_lib_object_idset.h"
51 #include "got_lib_privsep.h"
52 #include "got_lib_pack.h"
53 #include "got_lib_delta_cache.h"
54 
55 #ifndef nitems
56 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
57 #endif
58 
59 struct got_indexed_object {
60 	struct got_object_id id;
61 
62 	/*
63 	 * Has this object been fully resolved?
64 	 * If so, we know its ID, otherwise we don't and 'id' is invalid.
65 	 */
66 	int valid;
67 
68 	/* Offset of type+size field for this object in pack file. */
69 	off_t off;
70 
71 	/* Type+size values parsed from pack file. */
72 	uint8_t type;
73 	uint64_t size;
74 
75 	/* Length of on-disk type+size data. */
76 	size_t tslen; 
77 
78 	/* Length of object data following type+size. */
79 	size_t len; 
80 
81 	uint32_t crc;
82 
83 	union {
84 		struct {
85 			/* For ref deltas. */
86 			struct got_object_id ref_id;
87 		} ref;
88 		struct {
89 			/* For offset deltas. */
90 			off_t base_offset;
91 			size_t base_offsetlen;
92 		} ofs;
93 	} delta;
94 };
95 
96 static void
97 putbe32(char *b, uint32_t n)
98 {
99 	b[0] = n >> 24;
100 	b[1] = n >> 16;
101 	b[2] = n >> 8;
102 	b[3] = n >> 0;
103 }
104 
105 static const struct got_error *
106 get_obj_type_label(const char **label, int obj_type)
107 {
108 	const struct got_error *err = NULL;
109 
110 	switch (obj_type) {
111 	case GOT_OBJ_TYPE_BLOB:
112 		*label = GOT_OBJ_LABEL_BLOB;
113 		break;
114 	case GOT_OBJ_TYPE_TREE:
115 		*label = GOT_OBJ_LABEL_TREE;
116 		break;
117 	case GOT_OBJ_TYPE_COMMIT:
118 		*label = GOT_OBJ_LABEL_COMMIT;
119 		break;
120 	case GOT_OBJ_TYPE_TAG:
121 		*label = GOT_OBJ_LABEL_TAG;
122 		break;
123 	default:
124 		*label = NULL;
125 		err = got_error(GOT_ERR_OBJ_TYPE);
126 		break;
127 	}
128 
129 	return err;
130 }
131 
132 static const struct got_error *
133 read_checksum(uint32_t *crc, SHA1_CTX *sha1_ctx, int fd, size_t len)
134 {
135 	uint8_t buf[8192];
136 	size_t n;
137 	ssize_t r;
138 
139 	for (n = len; n > 0; n -= r){
140 		r = read(fd, buf, n > sizeof(buf) ? sizeof(buf) : n);
141 		if (r == -1)
142 			return got_error_from_errno("read");
143 		if (r == 0)
144 			break;
145 		if (crc)
146 			*crc = crc32(*crc, buf, r);
147 		if (sha1_ctx)
148 			SHA1Update(sha1_ctx, buf, r);
149 	}
150 
151 	return NULL;
152 }
153 
154 static const struct got_error *
155 read_file_sha1(SHA1_CTX *ctx, FILE *f, size_t len)
156 {
157 	uint8_t buf[8192];
158 	size_t n, r;
159 
160 	for (n = len; n > 0; n -= r) {
161 		r = fread(buf, 1, n > sizeof(buf) ? sizeof(buf) : n, f);
162 		if (r == 0) {
163 			if (feof(f))
164 				return NULL;
165 			return got_ferror(f, GOT_ERR_IO);
166 		}
167 		SHA1Update(ctx, buf, r);
168 	}
169 
170 	return NULL;
171 }
172 
173 static const struct got_error *
174 read_packed_object(struct got_pack *pack, struct got_indexed_object *obj,
175     FILE *tmpfile, SHA1_CTX *pack_sha1_ctx)
176 {
177 	const struct got_error *err = NULL;
178 	SHA1_CTX ctx;
179 	uint8_t *data = NULL;
180 	size_t datalen = 0;
181 	ssize_t n;
182 	char *header;
183 	size_t headerlen;
184 	const char *obj_label;
185 	size_t mapoff = obj->off;
186 	struct got_inflate_checksum csum;
187 
188 	csum.input_sha1 = pack_sha1_ctx;
189 	csum.input_crc = &obj->crc;
190 
191 	err = got_pack_parse_object_type_and_size(&obj->type, &obj->size,
192 	    &obj->tslen, pack, obj->off);
193 	if (err)
194 		return err;
195 
196 	if (pack->map) {
197 		obj->crc = crc32(obj->crc, pack->map + mapoff, obj->tslen);
198 		SHA1Update(pack_sha1_ctx, pack->map + mapoff, obj->tslen);
199 		mapoff += obj->tslen;
200 	} else {
201 		/* XXX Seek back and get the CRC of on-disk type+size bytes. */
202 		if (lseek(pack->fd, obj->off, SEEK_SET) == -1)
203 			return got_error_from_errno("lseek");
204 		err = read_checksum(&obj->crc, pack_sha1_ctx,
205 		    pack->fd, obj->tslen);
206 		if (err)
207 			return err;
208 	}
209 
210 	switch (obj->type) {
211 	case GOT_OBJ_TYPE_BLOB:
212 	case GOT_OBJ_TYPE_COMMIT:
213 	case GOT_OBJ_TYPE_TREE:
214 	case GOT_OBJ_TYPE_TAG:
215 		if (obj->size > GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
216 			if (fseek(tmpfile, 0L, SEEK_SET) == -1) {
217 				err = got_error_from_errno("fseek");
218 				break;
219 			}
220 			if (pack->map) {
221 				err = got_inflate_to_file_mmap(&datalen,
222 				    &obj->len, &csum, pack->map, mapoff,
223 				    pack->filesize - mapoff, tmpfile);
224 			} else {
225 				err = got_inflate_to_file_fd(&datalen,
226 				    &obj->len, &csum, pack->fd, tmpfile);
227 			}
228 		} else {
229 			if (pack->map) {
230 				err = got_inflate_to_mem_mmap(&data, &datalen,
231 				    &obj->len, &csum, pack->map, mapoff,
232 				    pack->filesize - mapoff);
233 			} else {
234 				err = got_inflate_to_mem_fd(&data, &datalen,
235 				    &obj->len, &csum, obj->size, pack->fd);
236 			}
237 		}
238 		if (err)
239 			break;
240 		SHA1Init(&ctx);
241 		err = get_obj_type_label(&obj_label, obj->type);
242 		if (err) {
243 			free(data);
244 			break;
245 		}
246 		if (asprintf(&header, "%s %lld", obj_label, obj->size) == -1) {
247 			err = got_error_from_errno("asprintf");
248 			free(data);
249 			break;
250 		}
251 		headerlen = strlen(header) + 1;
252 		SHA1Update(&ctx, header, headerlen);
253 		if (obj->size > GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
254 			err = read_file_sha1(&ctx, tmpfile, datalen);
255 			if (err)
256 				break;
257 		} else
258 			SHA1Update(&ctx, data, datalen);
259 		SHA1Final(obj->id.sha1, &ctx);
260 		free(header);
261 		free(data);
262 		break;
263 	case GOT_OBJ_TYPE_REF_DELTA:
264 		memset(obj->id.sha1, 0xff, SHA1_DIGEST_LENGTH);
265 		if (pack->map) {
266 			if (mapoff + SHA1_DIGEST_LENGTH >= pack->filesize) {
267 				err = got_error(GOT_ERR_BAD_PACKFILE);
268 				break;
269 			}
270 			memcpy(obj->delta.ref.ref_id.sha1, pack->map + mapoff,
271 			    SHA1_DIGEST_LENGTH);
272 			obj->crc = crc32(obj->crc, pack->map + mapoff,
273 			    SHA1_DIGEST_LENGTH);
274 			SHA1Update(pack_sha1_ctx, pack->map + mapoff,
275 			    SHA1_DIGEST_LENGTH);
276 			mapoff += SHA1_DIGEST_LENGTH;
277 			err = got_inflate_to_mem_mmap(NULL, &datalen,
278 			    &obj->len, &csum, pack->map, mapoff,
279 			    pack->filesize - mapoff);
280 			if (err)
281 				break;
282 		} else {
283 			n = read(pack->fd, obj->delta.ref.ref_id.sha1,
284 			    SHA1_DIGEST_LENGTH);
285 			if (n == -1) {
286 				err = got_error_from_errno("read");
287 				break;
288 			}
289 			if (n < sizeof(obj->id)) {
290 				err = got_error(GOT_ERR_BAD_PACKFILE);
291 				break;
292 			}
293 			obj->crc = crc32(obj->crc, obj->delta.ref.ref_id.sha1,
294 			    SHA1_DIGEST_LENGTH);
295 			SHA1Update(pack_sha1_ctx, obj->delta.ref.ref_id.sha1,
296 			    SHA1_DIGEST_LENGTH);
297 			err = got_inflate_to_mem_fd(NULL, &datalen, &obj->len,
298 			    &csum, obj->size, pack->fd);
299 			if (err)
300 				break;
301 		}
302 		obj->len += SHA1_DIGEST_LENGTH;
303 		break;
304 	case GOT_OBJ_TYPE_OFFSET_DELTA:
305 		memset(obj->id.sha1, 0xff, SHA1_DIGEST_LENGTH);
306 		err = got_pack_parse_offset_delta(&obj->delta.ofs.base_offset,
307 		    &obj->delta.ofs.base_offsetlen, pack, obj->off,
308 		    obj->tslen);
309 		if (err)
310 			break;
311 
312 		if (pack->map) {
313 			obj->crc = crc32(obj->crc, pack->map + mapoff,
314 			    obj->delta.ofs.base_offsetlen);
315 			SHA1Update(pack_sha1_ctx, pack->map + mapoff,
316 			    obj->delta.ofs.base_offsetlen);
317 			mapoff += obj->delta.ofs.base_offsetlen;
318 			err = got_inflate_to_mem_mmap(NULL, &datalen,
319 			    &obj->len, &csum, pack->map, mapoff,
320 			    pack->filesize - mapoff);
321 			if (err)
322 				break;
323 		} else {
324 			/*
325 			 * XXX Seek back and get CRC and SHA1 of on-disk
326 			 * offset bytes.
327 			 */
328 			if (lseek(pack->fd, obj->off + obj->tslen, SEEK_SET)
329 			    == -1) {
330 				err = got_error_from_errno("lseek");
331 				break;
332 			}
333 			err = read_checksum(&obj->crc, pack_sha1_ctx,
334 			    pack->fd, obj->delta.ofs.base_offsetlen);
335 			if (err)
336 				break;
337 
338 			err = got_inflate_to_mem_fd(NULL, &datalen, &obj->len,
339 			    &csum, obj->size, pack->fd);
340 			if (err)
341 				break;
342 		}
343 		obj->len += obj->delta.ofs.base_offsetlen;
344 		break;
345 	default:
346 		err = got_error(GOT_ERR_OBJ_TYPE);
347 		break;
348 	}
349 
350 	return err;
351 }
352 
353 static const struct got_error *
354 hwrite(int fd, void *buf, int len, SHA1_CTX *ctx)
355 {
356 	ssize_t w;
357 
358 	SHA1Update(ctx, buf, len);
359 
360 	w = write(fd, buf, len);
361 	if (w == -1)
362 		return got_error_from_errno("write");
363 	if (w != len)
364 		return got_error(GOT_ERR_IO);
365 
366 	return NULL;
367 }
368 
369 static const struct got_error *
370 resolve_deltified_object(struct got_pack *pack, struct got_packidx *packidx,
371     struct got_indexed_object *obj, FILE *tmpfile, FILE *delta_base_file,
372     FILE *delta_accum_file)
373 {
374 	const struct got_error *err = NULL;
375 	struct got_delta_chain deltas;
376 	struct got_delta *delta;
377 	uint8_t *buf = NULL;
378 	size_t len = 0;
379 	SHA1_CTX ctx;
380 	char *header = NULL;
381 	size_t headerlen;
382 	uint64_t max_size;
383 	int base_obj_type;
384 	const char *obj_label;
385 
386 	deltas.nentries = 0;
387 	SIMPLEQ_INIT(&deltas.entries);
388 
389 	err = got_pack_resolve_delta_chain(&deltas, packidx, pack,
390 	    obj->off, obj->tslen, obj->type, obj->size,
391 	    GOT_DELTA_CHAIN_RECURSION_MAX);
392 	if (err)
393 		goto done;
394 
395 	err = got_pack_get_delta_chain_max_size(&max_size, &deltas, pack);
396 	if (err)
397 		goto done;
398 	if (max_size > GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
399 		rewind(tmpfile);
400 		rewind(delta_base_file);
401 		rewind(delta_accum_file);
402 		err = got_pack_dump_delta_chain_to_file(&len, &deltas,
403 		    pack, tmpfile, delta_base_file, delta_accum_file);
404 		if (err)
405 			goto done;
406 	} else {
407 		err = got_pack_dump_delta_chain_to_mem(&buf, &len,
408 		    &deltas, pack);
409 	}
410 	if (err)
411 		goto done;
412 
413 	err = got_delta_chain_get_base_type(&base_obj_type, &deltas);
414 	if (err)
415 		goto done;
416 	err = get_obj_type_label(&obj_label, base_obj_type);
417 	if (err)
418 		goto done;
419 	if (asprintf(&header, "%s %zd", obj_label, len) == -1) {
420 		err = got_error_from_errno("asprintf");
421 		goto done;
422 	}
423 	headerlen = strlen(header) + 1;
424 	SHA1Init(&ctx);
425 	SHA1Update(&ctx, header, headerlen);
426 	if (max_size > GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
427 		err = read_file_sha1(&ctx, tmpfile, len);
428 		if (err)
429 			goto done;
430 	} else
431 		SHA1Update(&ctx, buf, len);
432 	SHA1Final(obj->id.sha1, &ctx);
433 done:
434 	free(buf);
435 	free(header);
436 	while (!SIMPLEQ_EMPTY(&deltas.entries)) {
437 		delta = SIMPLEQ_FIRST(&deltas.entries);
438 		SIMPLEQ_REMOVE_HEAD(&deltas.entries, entry);
439 		free(delta);
440 	}
441 	return err;
442 }
443 
444 /* Determine the slot in the pack index a given object ID should use. */
445 static int
446 find_object_idx(struct got_packidx *packidx, uint8_t *sha1)
447 {
448 	u_int8_t id0 = sha1[0];
449 	uint32_t nindexed = betoh32(packidx->hdr.fanout_table[0xff]);
450 	int left = 0, right = nindexed - 1;
451 	int cmp = 0, i = 0;
452 
453 	if (id0 > 0)
454 		left = betoh32(packidx->hdr.fanout_table[id0 - 1]);
455 
456 	while (left <= right) {
457 		struct got_packidx_object_id *oid;
458 
459 		i = ((left + right) / 2);
460 		oid = &packidx->hdr.sorted_ids[i];
461 
462 		cmp = memcmp(sha1, oid->sha1, SHA1_DIGEST_LENGTH);
463 		if (cmp == 0)
464 			return -1; /* object already indexed */
465 		else if (cmp > 0)
466 			left = i + 1;
467 		else if (cmp < 0)
468 			right = i - 1;
469 	}
470 
471 	return left;
472 }
473 
474 #if 0
475 static void
476 print_packidx(struct got_packidx *packidx)
477 {
478 	uint32_t nindexed = betoh32(packidx->hdr.fanout_table[0xff]);
479 	int i;
480 
481 	fprintf(stderr, "object IDs:\n");
482 	for (i = 0; i < nindexed; i++) {
483 		char hex[SHA1_DIGEST_STRING_LENGTH];
484 		got_sha1_digest_to_str(packidx->hdr.sorted_ids[i].sha1,
485 		    hex, sizeof(hex));
486 		fprintf(stderr, "%s\n", hex);
487 	}
488 	fprintf(stderr, "\n");
489 
490 	fprintf(stderr, "object offsets:\n");
491 	for (i = 0; i < nindexed; i++) {
492 		uint32_t offset = be32toh(packidx->hdr.offsets[i]);
493 		if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
494 			int j = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
495 			fprintf(stderr, "%u -> %llu\n", offset, 
496 			    be64toh(packidx->hdr.large_offsets[j]));
497 		} else
498 			fprintf(stderr, "%u\n", offset);
499 	}
500 	fprintf(stderr, "\n");
501 
502 	fprintf(stderr, "fanout table:");
503 	for (i = 0; i <= 0xff; i++)
504 		fprintf(stderr, " %u", be32toh(packidx->hdr.fanout_table[i]));
505 	fprintf(stderr, "\n");
506 }
507 #endif
508 
509 static void
510 add_indexed_object(struct got_packidx *packidx, uint32_t idx,
511     struct got_indexed_object *obj)
512 {
513 	int i;
514 
515 	memcpy(packidx->hdr.sorted_ids[idx].sha1, obj->id.sha1,
516 	    SHA1_DIGEST_LENGTH);
517 	packidx->hdr.crc32[idx] = htobe32(obj->crc);
518 	if (obj->off < GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX)
519 		packidx->hdr.offsets[idx] = htobe32(obj->off);
520 	else {
521 		packidx->hdr.offsets[idx] = htobe32(packidx->nlargeobj |
522 		    GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX);
523 		packidx->hdr.large_offsets[packidx->nlargeobj] =
524 		    htobe64(obj->off);
525 		packidx->nlargeobj++;
526 	}
527 
528 	for (i = obj->id.sha1[0]; i <= 0xff; i++) {
529 		uint32_t n = be32toh(packidx->hdr.fanout_table[i]);
530 		packidx->hdr.fanout_table[i] = htobe32(n + 1);
531 	}
532 }
533 
534 static int
535 indexed_obj_cmp(const void *pa, const void *pb)
536 {
537 	struct got_indexed_object *a, *b;
538 
539 	a = (struct got_indexed_object *)pa;
540 	b = (struct got_indexed_object *)pb;
541 	return got_object_id_cmp(&a->id, &b->id);
542 }
543 
544 static void
545 make_packidx(struct got_packidx *packidx, int nobj,
546     struct got_indexed_object *objects)
547 {
548 	struct got_indexed_object *obj;
549 	int i;
550 	uint32_t idx = 0;
551 
552 	qsort(objects, nobj, sizeof(struct got_indexed_object),
553 	    indexed_obj_cmp);
554 
555 	memset(packidx->hdr.fanout_table, 0,
556 	    GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS * sizeof(uint32_t));
557 	packidx->nlargeobj = 0;
558 
559 	for (i = 0; i < nobj; i++) {
560 		obj = &objects[i];
561 		if (obj->valid)
562 			add_indexed_object(packidx, idx++, obj);
563 	}
564 }
565 
566 static void
567 update_packidx(struct got_packidx *packidx, int nobj,
568     struct got_indexed_object *obj)
569 {
570 	uint32_t idx;
571 	uint32_t nindexed = betoh32(packidx->hdr.fanout_table[0xff]);
572 
573 	idx = find_object_idx(packidx, obj->id.sha1);
574 	if (idx == -1) {
575 		char hex[SHA1_DIGEST_STRING_LENGTH];
576 		got_sha1_digest_to_str(obj->id.sha1, hex, sizeof(hex));
577 		return; /* object already indexed */
578 	}
579 
580 	memmove(&packidx->hdr.sorted_ids[idx + 1],
581 	    &packidx->hdr.sorted_ids[idx],
582 	    sizeof(struct got_packidx_object_id) * (nindexed - idx));
583 	memmove(&packidx->hdr.offsets[idx + 1], &packidx->hdr.offsets[idx],
584 	    sizeof(uint32_t) * (nindexed - idx));
585 
586 	add_indexed_object(packidx, idx, obj);
587 }
588 
589 static const struct got_error *
590 send_index_pack_progress(struct imsgbuf *ibuf, int nobj_total,
591     int nobj_indexed, int nobj_loose, int nobj_resolved)
592 {
593 	struct got_imsg_index_pack_progress iprogress;
594 
595 	iprogress.nobj_total = nobj_total;
596 	iprogress.nobj_indexed = nobj_indexed;
597 	iprogress.nobj_loose = nobj_loose;
598 	iprogress.nobj_resolved = nobj_resolved;
599 
600 	if (imsg_compose(ibuf, GOT_IMSG_IDXPACK_PROGRESS, 0, 0, -1,
601 	    &iprogress, sizeof(iprogress)) == -1)
602 		return got_error_from_errno("imsg_compose IDXPACK_PROGRESS");
603 
604 	return got_privsep_flush_imsg(ibuf);
605 }
606 
607 static const struct got_error *
608 send_index_pack_done(struct imsgbuf *ibuf)
609 {
610 	if (imsg_compose(ibuf, GOT_IMSG_IDXPACK_DONE, 0, 0, -1, NULL, 0) == -1)
611 		return got_error_from_errno("imsg_compose FETCH");
612 	return got_privsep_flush_imsg(ibuf);
613 }
614 
615 
616 static const struct got_error *
617 index_pack(struct got_pack *pack, int idxfd, FILE *tmpfile,
618     FILE *delta_base_file, FILE *delta_accum_file, uint8_t *pack_sha1_expected,
619     struct imsgbuf *ibuf)
620 {
621 	const struct got_error *err;
622 	struct got_packfile_hdr hdr;
623 	struct got_packidx packidx;
624 	char buf[8];
625 	char pack_sha1[SHA1_DIGEST_LENGTH];
626 	int nobj, nvalid, nloose, nresolved = 0, i;
627 	struct got_indexed_object *objects = NULL, *obj;
628 	SHA1_CTX ctx;
629 	uint8_t packidx_hash[SHA1_DIGEST_LENGTH];
630 	ssize_t r, w;
631 	int pass, have_ref_deltas = 0, first_delta_idx = -1;
632 	size_t mapoff = 0;
633 	int p_indexed = 0, last_p_indexed = -1;
634 	int p_resolved = 0, last_p_resolved = -1;
635 
636 	/* Require that pack file header and SHA1 trailer are present. */
637 	if (pack->filesize < sizeof(hdr) + SHA1_DIGEST_LENGTH)
638 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
639 		    "short pack file");
640 
641 	if (pack->map) {
642 		memcpy(&hdr, pack->map, sizeof(hdr));
643 		mapoff += sizeof(hdr);
644 	} else {
645 		r = read(pack->fd, &hdr, sizeof(hdr));
646 		if (r == -1)
647 			return got_error_from_errno("read");
648 		if (r < sizeof(hdr))
649 			return got_error_msg(GOT_ERR_BAD_PACKFILE,
650 			    "short pack file");
651 	}
652 
653 	if (hdr.signature != htobe32(GOT_PACKFILE_SIGNATURE))
654 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
655 		    "bad packfile signature");
656 	if (hdr.version != htobe32(GOT_PACKFILE_VERSION))
657 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
658 		    "bad packfile version");
659 	nobj = betoh32(hdr.nobjects);
660 	if (nobj == 0)
661 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
662 		    "bad packfile with zero objects");
663 
664 	/* We compute the SHA1 of pack file contents and verify later on. */
665 	SHA1Init(&ctx);
666 	SHA1Update(&ctx, (void *)&hdr, sizeof(hdr));
667 
668 	/*
669 	 * Create an in-memory pack index which will grow as objects
670 	 * IDs in the pack file are discovered. Only fields used to
671 	 * read deltified objects will be needed by the pack.c library
672 	 * code, so setting up just a pack index header is sufficient.
673 	 */
674 	memset(&packidx, 0, sizeof(packidx));
675 	packidx.hdr.magic = malloc(sizeof(uint32_t));
676 	if (packidx.hdr.magic == NULL)
677 		return got_error_from_errno("calloc");
678 	*packidx.hdr.magic = htobe32(GOT_PACKIDX_V2_MAGIC);
679 	packidx.hdr.version = malloc(sizeof(uint32_t));
680 	if (packidx.hdr.version == NULL) {
681 		err = got_error_from_errno("malloc");
682 		goto done;
683 	}
684 	*packidx.hdr.version = htobe32(GOT_PACKIDX_VERSION);
685 	packidx.hdr.fanout_table = calloc(GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS,
686 	    sizeof(uint32_t));
687 	if (packidx.hdr.fanout_table == NULL) {
688 		err = got_error_from_errno("calloc");
689 		goto done;
690 	}
691 	packidx.hdr.sorted_ids = calloc(nobj,
692 	    sizeof(struct got_packidx_object_id));
693 	if (packidx.hdr.sorted_ids == NULL) {
694 		err = got_error_from_errno("calloc");
695 		goto done;
696 	}
697 	packidx.hdr.crc32 = calloc(nobj, sizeof(uint32_t));
698 	if (packidx.hdr.crc32 == NULL) {
699 		err = got_error_from_errno("calloc");
700 		goto done;
701 	}
702 	packidx.hdr.offsets = calloc(nobj, sizeof(uint32_t));
703 	if (packidx.hdr.offsets == NULL) {
704 		err = got_error_from_errno("calloc");
705 		goto done;
706 	}
707 	/* Large offsets table is empty for pack files < 2 GB. */
708 	if (pack->filesize >= GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
709 		packidx.hdr.large_offsets = calloc(nobj, sizeof(uint64_t));
710 		if (packidx.hdr.large_offsets == NULL) {
711 			err = got_error_from_errno("calloc");
712 			goto done;
713 		}
714 	}
715 
716 	nvalid = 0;
717 	nloose = 0;
718 	objects = calloc(nobj, sizeof(struct got_indexed_object));
719 	if (objects == NULL)
720 		return got_error_from_errno("calloc");
721 
722 	/*
723 	 * First pass: locate all objects and identify un-deltified objects.
724 	 *
725 	 * When this pass has completed we will know offset, type, size, and
726 	 * CRC information for all objects in this pack file. We won't know
727 	 * any of the actual object IDs of deltified objects yet since we
728 	 * will not yet attempt to combine deltas.
729 	 */
730 	pass = 1;
731 	for (i = 0; i < nobj; i++) {
732 		/* Don't send too many progress privsep messages. */
733 		p_indexed = ((i + 1) * 100) / nobj;
734 		if (p_indexed != last_p_indexed) {
735 			err = send_index_pack_progress(ibuf, nobj, i + 1,
736 			    nloose, 0);
737 			if (err)
738 				goto done;
739 			last_p_indexed = p_indexed;
740 		}
741 
742 		obj = &objects[i];
743 		obj->crc = crc32(0L, NULL, 0);
744 
745 		/* Store offset to type+size information for this object. */
746 		if (pack->map) {
747 			obj->off = mapoff;
748 		} else {
749 			obj->off = lseek(pack->fd, 0, SEEK_CUR);
750 			if (obj->off == -1) {
751 				err = got_error_from_errno("lseek");
752 				goto done;
753 			}
754 		}
755 
756 		err = read_packed_object(pack, obj, tmpfile, &ctx);
757 		if (err)
758 			goto done;
759 
760 		if (pack->map) {
761 			mapoff += obj->tslen + obj->len;
762 		} else {
763 			if (lseek(pack->fd, obj->off + obj->tslen + obj->len,
764 			    SEEK_SET) == -1) {
765 				err = got_error_from_errno("lseek");
766 				goto done;
767 			}
768 		}
769 
770 		if (obj->type == GOT_OBJ_TYPE_BLOB ||
771 		    obj->type == GOT_OBJ_TYPE_TREE ||
772 		    obj->type == GOT_OBJ_TYPE_COMMIT ||
773 		    obj->type == GOT_OBJ_TYPE_TAG) {
774 			obj->valid = 1;
775 			nloose++;
776 		} else {
777 			if (first_delta_idx == -1)
778 				first_delta_idx = i;
779 			if (obj->type == GOT_OBJ_TYPE_REF_DELTA)
780 				have_ref_deltas = 1;
781 		}
782 	}
783 	nvalid = nloose;
784 
785 	/*
786 	 * Having done a full pass over the pack file and can now
787 	 * verify its checksum.
788 	 */
789 	SHA1Final(pack_sha1, &ctx);
790 	if (memcmp(pack_sha1_expected, pack_sha1, SHA1_DIGEST_LENGTH) != 0) {
791 		err = got_error_msg(GOT_ERR_BAD_PACKFILE,
792 		    "pack file checksum mismatch");
793 		goto done;
794 	}
795 
796 	/* Verify the SHA1 checksum stored at the end of the pack file. */
797 	if (pack->map) {
798 		memcpy(pack_sha1_expected, pack->map +
799 		    pack->filesize - SHA1_DIGEST_LENGTH,
800 		    SHA1_DIGEST_LENGTH);
801 	} else {
802 		ssize_t n;
803 		if (lseek(pack->fd, -SHA1_DIGEST_LENGTH, SEEK_END) == -1) {
804 			err = got_error_from_errno("lseek");
805 			goto done;
806 		}
807 		n = read(pack->fd, pack_sha1_expected, SHA1_DIGEST_LENGTH);
808 		if (n == -1) {
809 			err = got_error_from_errno("read");
810 			goto done;
811 		}
812 		if (n != SHA1_DIGEST_LENGTH) {
813 			err = got_error(GOT_ERR_IO);
814 			goto done;
815 		}
816 	}
817 	if (memcmp(pack_sha1, pack_sha1_expected, SHA1_DIGEST_LENGTH) != 0) {
818 		err = got_error_msg(GOT_ERR_BAD_PACKFILE,
819 		    "bad checksum in pack file trailer");
820 		goto done;
821 	}
822 
823 	if (first_delta_idx == -1)
824 		first_delta_idx = 0;
825 
826 	/* In order to resolve ref deltas we need an in-progress pack index. */
827 	if (have_ref_deltas)
828 		make_packidx(&packidx, nobj, objects);
829 
830 	/*
831 	 * Second pass: We can now resolve deltas to compute the IDs of
832 	 * objects which appear in deltified form. Because deltas can be
833 	 * chained this pass may require a couple of iterations until all
834 	 * IDs of deltified objects have been discovered.
835 	 */
836 	pass++;
837 	while (nvalid != nobj) {
838 		int n = 0;
839 		/*
840 		 * This loop will only run once unless the pack file
841 		 * contains ref deltas which refer to objects located
842 		 * later in the pack file, which is unusual.
843 		 * Offset deltas can always be resolved in one pass
844 		 * unless the packfile is corrupt.
845 		 */
846 		for (i = first_delta_idx; i < nobj; i++) {
847 			obj = &objects[i];
848 			if (obj->type != GOT_OBJ_TYPE_REF_DELTA &&
849 			    obj->type != GOT_OBJ_TYPE_OFFSET_DELTA)
850 				continue;
851 
852 			if (obj->valid)
853 				continue;
854 
855 			if (pack->map == NULL && lseek(pack->fd,
856 			    obj->off + obj->tslen, SEEK_SET) == -1) {
857 				err = got_error_from_errno("lseek");
858 				goto done;
859 			}
860 
861 			err = resolve_deltified_object(pack, &packidx, obj,
862 			    tmpfile, delta_base_file, delta_accum_file);
863 			if (err) {
864 				if (err->code != GOT_ERR_NO_OBJ)
865 					goto done;
866 				/*
867 				 * We cannot resolve this object yet because
868 				 * a delta base is unknown. Try again later.
869 				 */
870 				continue;
871 			}
872 
873 			obj->valid = 1;
874 			n++;
875 			if (have_ref_deltas)
876 				update_packidx(&packidx, nobj, obj);
877 			/* Don't send too many progress privsep messages. */
878 			p_resolved = ((nresolved + n) * 100) / nobj;
879 			if (p_resolved != last_p_resolved) {
880 				err = send_index_pack_progress(ibuf, nobj,
881 				    nobj, nloose, nresolved + n);
882 				if (err)
883 					goto done;
884 				last_p_resolved = p_resolved;
885 			}
886 
887 		}
888 		if (pass++ > 3 && n == 0) {
889 			static char msg[64];
890 			snprintf(msg, sizeof(msg), "could not resolve "
891 			    "any of deltas; packfile could be corrupt");
892 			err = got_error_msg(GOT_ERR_BAD_PACKFILE, msg);
893 			goto done;
894 			
895 		}
896 		nresolved += n;
897 		nvalid += nresolved;
898 	}
899 
900 	if (nloose + nresolved != nobj) {
901 		static char msg[64];
902 		snprintf(msg, sizeof(msg), "discovered only %d of %d objects",
903 		    nloose + nresolved, nobj);
904 		err = got_error_msg(GOT_ERR_BAD_PACKFILE, msg);
905 		goto done;
906 	}
907 
908 	err = send_index_pack_progress(ibuf, nobj, nobj, nloose, nresolved);
909 	if (err)
910 		goto done;
911 
912 	make_packidx(&packidx, nobj, objects);
913 
914 	free(objects);
915 	objects = NULL;
916 
917 	SHA1Init(&ctx);
918 	putbe32(buf, GOT_PACKIDX_V2_MAGIC);
919 	putbe32(buf + 4, GOT_PACKIDX_VERSION);
920 	err = hwrite(idxfd, buf, 8, &ctx);
921 	if (err)
922 		goto done;
923 	err = hwrite(idxfd, packidx.hdr.fanout_table,
924 	    GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS * sizeof(uint32_t), &ctx);
925 	if (err)
926 		goto done;
927 	err = hwrite(idxfd, packidx.hdr.sorted_ids,
928 	    nobj * SHA1_DIGEST_LENGTH, &ctx);
929 	if (err)
930 		goto done;
931 	err = hwrite(idxfd, packidx.hdr.crc32, nobj * sizeof(uint32_t), &ctx);
932 	if (err)
933 		goto done;
934 	err = hwrite(idxfd, packidx.hdr.offsets, nobj * sizeof(uint32_t),
935 	    &ctx);
936 	if (err)
937 		goto done;
938 	if (packidx.nlargeobj > 0) {
939 		err = hwrite(idxfd, packidx.hdr.large_offsets,
940 		    packidx.nlargeobj * sizeof(uint64_t), &ctx);
941 		if (err)
942 			goto done;
943 	}
944 	err = hwrite(idxfd, pack_sha1, SHA1_DIGEST_LENGTH, &ctx);
945 	if (err)
946 		goto done;
947 
948 	SHA1Final(packidx_hash, &ctx);
949 	w = write(idxfd, packidx_hash, sizeof(packidx_hash));
950 	if (w == -1) {
951 		err = got_error_from_errno("write");
952 		goto done;
953 	}
954 	if (w != sizeof(packidx_hash)) {
955 		err = got_error(GOT_ERR_IO);
956 		goto done;
957 	}
958 done:
959 	free(objects);
960 	free(packidx.hdr.magic);
961 	free(packidx.hdr.version);
962 	free(packidx.hdr.fanout_table);
963 	free(packidx.hdr.sorted_ids);
964 	free(packidx.hdr.offsets);
965 	free(packidx.hdr.large_offsets);
966 	return err;
967 }
968 
969 int
970 main(int argc, char **argv)
971 {
972 	const struct got_error *err = NULL, *close_err;
973 	struct imsgbuf ibuf;
974 	struct imsg imsg;
975 	int idxfd = -1, tmpfd = -1, i;
976 	FILE *tmpfiles[3];
977 	struct got_pack pack;
978 	uint8_t pack_hash[SHA1_DIGEST_LENGTH];
979 	off_t packfile_size;
980 #if 0
981 	static int attached;
982 	while (!attached)
983 		sleep(1);
984 #endif
985 
986 	for (i = 0; i < nitems(tmpfiles); i++)
987 		tmpfiles[i] = NULL;
988 
989 	memset(&pack, 0, sizeof(pack));
990 	pack.fd = -1;
991 	pack.delta_cache = got_delta_cache_alloc(500,
992 	    GOT_DELTA_RESULT_SIZE_CACHED_MAX);
993 	if (pack.delta_cache == NULL) {
994 		err = got_error_from_errno("got_delta_cache_alloc");
995 		goto done;
996 	}
997 
998 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
999 #ifndef PROFILE
1000 	/* revoke access to most system calls */
1001 	if (pledge("stdio recvfd", NULL) == -1) {
1002 		err = got_error_from_errno("pledge");
1003 		got_privsep_send_error(&ibuf, err);
1004 		return 1;
1005 	}
1006 #endif
1007 	err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
1008 	if (err)
1009 		goto done;
1010 	if (imsg.hdr.type == GOT_IMSG_STOP)
1011 		goto done;
1012 	if (imsg.hdr.type != GOT_IMSG_IDXPACK_REQUEST) {
1013 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1014 		goto done;
1015 	}
1016 	if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(pack_hash)) {
1017 		err = got_error(GOT_ERR_PRIVSEP_LEN);
1018 		goto done;
1019 	}
1020 	memcpy(pack_hash, imsg.data, sizeof(pack_hash));
1021 	pack.fd = imsg.fd;
1022 
1023 	err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
1024 	if (err)
1025 		goto done;
1026 	if (imsg.hdr.type == GOT_IMSG_STOP)
1027 		goto done;
1028 	if (imsg.hdr.type != GOT_IMSG_IDXPACK_OUTFD) {
1029 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1030 		goto done;
1031 	}
1032 	if (imsg.hdr.len - IMSG_HEADER_SIZE != 0) {
1033 		err = got_error(GOT_ERR_PRIVSEP_LEN);
1034 		goto done;
1035 	}
1036 	idxfd = imsg.fd;
1037 
1038 	for (i = 0; i < nitems(tmpfiles); i++) {
1039 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
1040 		if (err)
1041 			goto done;
1042 		if (imsg.hdr.type == GOT_IMSG_STOP)
1043 			goto done;
1044 		if (imsg.hdr.type != GOT_IMSG_TMPFD) {
1045 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1046 			goto done;
1047 		}
1048 		if (imsg.hdr.len - IMSG_HEADER_SIZE != 0) {
1049 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1050 			goto done;
1051 		}
1052 		tmpfd = imsg.fd;
1053 		tmpfiles[i] = fdopen(tmpfd, "w+");
1054 		if (tmpfiles[i] == NULL) {
1055 			err = got_error_from_errno("fdopen");
1056 			goto done;
1057 		}
1058 		tmpfd = -1;
1059 	}
1060 
1061 	if (lseek(pack.fd, 0, SEEK_END) == -1) {
1062 		err = got_error_from_errno("lseek");
1063 		goto done;
1064 	}
1065 	packfile_size = lseek(pack.fd, 0, SEEK_CUR);
1066 	if (packfile_size == -1) {
1067 		err = got_error_from_errno("lseek");
1068 		goto done;
1069 	}
1070 	pack.filesize = packfile_size; /* XXX off_t vs size_t */
1071 
1072 	if (lseek(pack.fd, 0, SEEK_SET) == -1) {
1073 		err = got_error_from_errno("lseek");
1074 		goto done;
1075 	}
1076 
1077 #ifndef GOT_PACK_NO_MMAP
1078 	pack.map = mmap(NULL, pack.filesize, PROT_READ, MAP_PRIVATE,
1079 	    pack.fd, 0);
1080 	if (pack.map == MAP_FAILED)
1081 		pack.map = NULL; /* fall back to read(2) */
1082 #endif
1083 	err = index_pack(&pack, idxfd, tmpfiles[0], tmpfiles[1], tmpfiles[2],
1084 	    pack_hash, &ibuf);
1085 done:
1086 	close_err = got_pack_close(&pack);
1087 	if (close_err && err == NULL)
1088 		err = close_err;
1089 	if (idxfd != -1 && close(idxfd) == -1 && err == NULL)
1090 		err = got_error_from_errno("close");
1091 	if (tmpfd != -1 && close(tmpfd) == -1 && err == NULL)
1092 		err = got_error_from_errno("close");
1093 	for (i = 0; i < nitems(tmpfiles); i++) {
1094 		if (tmpfiles[i] != NULL && fclose(tmpfiles[i]) == EOF &&
1095 		    err == NULL)
1096 			err = got_error_from_errno("close");
1097 	}
1098 
1099 	if (err == NULL)
1100 		err = send_index_pack_done(&ibuf);
1101 	if (err) {
1102 		got_privsep_send_error(&ibuf, err);
1103 		fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
1104 		got_privsep_send_error(&ibuf, err);
1105 		exit(1);
1106 	}
1107 
1108 	exit(0);
1109 }