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Date:: Wed Mar 18 16:13:44 2020 UTC
Message:: avoid magic numbers when writing pack index header in got-index-pack
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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 struct got_indexed_object {
56 	struct got_object_id id;
57 
58 	/*
59 	 * Has this object been fully resolved?
60 	 * If so, we know its ID, otherwise we don't and 'id' is invalid.
61 	 */
62 	int valid;
63 
64 	/* Offset of type+size field for this object in pack file. */
65 	off_t off;
66 
67 	/* Type+size values parsed from pack file. */
68 	uint8_t type;
69 	uint64_t size;
70 
71 	/* Length of on-disk type+size data. */
72 	size_t tslen; 
73 
74 	/* Length of object data following type+size. */
75 	size_t len; 
76 
77 	uint32_t crc;
78 
79 	union {
80 		struct {
81 			/* For ref deltas. */
82 			struct got_object_id ref_id;
83 		} ref;
84 		struct {
85 			/* For offset deltas. */
86 			off_t base_offset;
87 			size_t base_offsetlen;
88 		} ofs;
89 	} delta;
90 };
91 
92 static void
93 putbe32(char *b, uint32_t n)
94 {
95 	b[0] = n >> 24;
96 	b[1] = n >> 16;
97 	b[2] = n >> 8;
98 	b[3] = n >> 0;
99 }
100 
101 static const struct got_error *
102 get_obj_type_label(const char **label, int obj_type)
103 {
104 	const struct got_error *err = NULL;
105 
106 	switch (obj_type) {
107 	case GOT_OBJ_TYPE_BLOB:
108 		*label = GOT_OBJ_LABEL_BLOB;
109 		break;
110 	case GOT_OBJ_TYPE_TREE:
111 		*label = GOT_OBJ_LABEL_TREE;
112 		break;
113 	case GOT_OBJ_TYPE_COMMIT:
114 		*label = GOT_OBJ_LABEL_COMMIT;
115 		break;
116 	case GOT_OBJ_TYPE_TAG:
117 		*label = GOT_OBJ_LABEL_TAG;
118 		break;
119 	default:
120 		*label = NULL;
121 		err = got_error(GOT_ERR_OBJ_TYPE);
122 		break;
123 	}
124 
125 	return err;
126 }
127 
128 static const struct got_error *
129 read_crc(uint32_t *crc, int fd, size_t len)
130 {
131 	uint8_t buf[8192];
132 	size_t n;
133 	ssize_t r;
134 
135 	for (n = len; n > 0; n -= r){
136 		r = read(fd, buf, n > sizeof(buf) ? sizeof(buf) : n);
137 		if (r == -1)
138 			return got_error_from_errno("read");
139 		if (r == 0)
140 			break;
141 		*crc = crc32(*crc, buf, r);
142 	}
143 
144 	return NULL;
145 }
146 
147 static const struct got_error *
148 read_packed_object(struct got_pack *pack, struct got_indexed_object *obj)
149 {
150 	const struct got_error *err = NULL;
151 	SHA1_CTX ctx;
152 	uint8_t *data;
153 	size_t datalen;
154 	ssize_t n;
155 	char *header;
156 	size_t headerlen;
157 	const char *obj_label;
158 	size_t mapoff = obj->off;
159 
160 	err = got_pack_parse_object_type_and_size(&obj->type, &obj->size,
161 	    &obj->tslen, pack, obj->off);
162 	if (err)
163 		return err;
164 
165 	if (pack->map) {
166 		obj->crc = crc32(obj->crc, pack->map + mapoff, obj->tslen);
167 		mapoff += obj->tslen;
168 	} else {
169 		/* XXX Seek back and get the CRC of on-disk type+size bytes. */
170 		if (lseek(pack->fd, obj->off, SEEK_SET) == -1)
171 			return got_error_from_errno("lseek");
172 		err = read_crc(&obj->crc, pack->fd, obj->tslen);
173 		if (err)
174 			return err;
175 	}
176 
177 	switch (obj->type) {
178 	case GOT_OBJ_TYPE_BLOB:
179 	case GOT_OBJ_TYPE_COMMIT:
180 	case GOT_OBJ_TYPE_TREE:
181 	case GOT_OBJ_TYPE_TAG:
182 		/* XXX TODO reading large objects into memory is bad! */
183 		if (pack->map) {
184 			err = got_inflate_to_mem_mmap(&data, &datalen,
185 			    &obj->len, &obj->crc, pack->map, mapoff,
186 			    pack->filesize - mapoff);
187 		} else {
188 			err = got_inflate_to_mem_fd(&data, &datalen,
189 			    &obj->len, &obj->crc, obj->size, pack->fd);
190 		}
191 		if (err)
192 			break;
193 		SHA1Init(&ctx);
194 		err = get_obj_type_label(&obj_label, obj->type);
195 		if (err) {
196 			free(data);
197 			break;
198 		}
199 		if (asprintf(&header, "%s %lld", obj_label, obj->size) == -1) {
200 			err = got_error_from_errno("asprintf");
201 			free(data);
202 			break;
203 		}
204 		headerlen = strlen(header) + 1;
205 		SHA1Update(&ctx, header, headerlen);
206 		SHA1Update(&ctx, data, datalen);
207 		SHA1Final(obj->id.sha1, &ctx);
208 		free(header);
209 		free(data);
210 		break;
211 	case GOT_OBJ_TYPE_REF_DELTA:
212 		memset(obj->id.sha1, 0xff, SHA1_DIGEST_LENGTH);
213 		if (pack->map) {
214 			if (mapoff + SHA1_DIGEST_LENGTH >= pack->filesize) {
215 				err = got_error(GOT_ERR_BAD_PACKFILE);
216 				break;
217 			}
218 			memcpy(obj->delta.ref.ref_id.sha1, pack->map + mapoff,
219 			    SHA1_DIGEST_LENGTH);
220 			obj->crc = crc32(obj->crc, pack->map + mapoff,
221 			    SHA1_DIGEST_LENGTH);
222 			mapoff += SHA1_DIGEST_LENGTH;
223 			err = got_inflate_to_mem_mmap(NULL, &datalen,
224 			    &obj->len, &obj->crc, pack->map, mapoff,
225 			    pack->filesize - mapoff);
226 			if (err)
227 				break;
228 		} else {
229 			n = read(pack->fd, obj->delta.ref.ref_id.sha1,
230 			    SHA1_DIGEST_LENGTH);
231 			if (n == -1) {
232 				err = got_error_from_errno("read");
233 				break;
234 			}
235 			if (n < sizeof(obj->id)) {
236 				err = got_error(GOT_ERR_BAD_PACKFILE);
237 				break;
238 			}
239 			obj->crc = crc32(obj->crc, obj->delta.ref.ref_id.sha1,
240 			    SHA1_DIGEST_LENGTH);
241 			err = got_inflate_to_mem_fd(NULL, &datalen, &obj->len,
242 			    &obj->crc, obj->size, pack->fd);
243 			if (err)
244 				break;
245 		}
246 		obj->len += SHA1_DIGEST_LENGTH;
247 		break;
248 	case GOT_OBJ_TYPE_OFFSET_DELTA:
249 		memset(obj->id.sha1, 0xff, SHA1_DIGEST_LENGTH);
250 		err = got_pack_parse_offset_delta(&obj->delta.ofs.base_offset,
251 		    &obj->delta.ofs.base_offsetlen, pack, obj->off,
252 		    obj->tslen);
253 		if (err)
254 			break;
255 
256 		if (pack->map) {
257 			obj->crc = crc32(obj->crc, pack->map + mapoff,
258 			    obj->delta.ofs.base_offsetlen);
259 			mapoff += obj->delta.ofs.base_offsetlen;
260 			err = got_inflate_to_mem_mmap(NULL, &datalen,
261 			    &obj->len, &obj->crc, pack->map, mapoff,
262 			    pack->filesize - mapoff);
263 			if (err)
264 				break;
265 		} else {
266 			/*
267 			 * XXX Seek back and get the CRC of on-disk
268 			 * offset bytes.
269 			 */
270 			if (lseek(pack->fd, obj->off + obj->tslen, SEEK_SET)
271 			    == -1) {
272 				err = got_error_from_errno("lseek");
273 				break;
274 			}
275 			err = read_crc(&obj->crc, pack->fd,
276 			    obj->delta.ofs.base_offsetlen);
277 			if (err)
278 				break;
279 
280 			err = got_inflate_to_mem_fd(NULL, &datalen, &obj->len,
281 			    &obj->crc, obj->size, pack->fd);
282 			if (err)
283 				break;
284 		}
285 		obj->len += obj->delta.ofs.base_offsetlen;
286 		break;
287 	default:
288 		err = got_error(GOT_ERR_OBJ_TYPE);
289 		break;
290 	}
291 
292 	return err;
293 }
294 
295 static const struct got_error *
296 hwrite(int fd, void *buf, int len, SHA1_CTX *ctx)
297 {
298 	ssize_t w;
299 
300 	SHA1Update(ctx, buf, len);
301 
302 	w = write(fd, buf, len);
303 	if (w == -1)
304 		return got_error_from_errno("write");
305 	if (w != len)
306 		return got_error(GOT_ERR_IO);
307 
308 	return NULL;
309 }
310 
311 static const struct got_error *
312 resolve_deltified_object(struct got_pack *pack, struct got_packidx *packidx,
313     struct got_indexed_object *obj)
314 {
315 	const struct got_error *err = NULL;
316 	struct got_delta_chain deltas;
317 	struct got_delta *delta;
318 	uint8_t *buf = NULL;
319 	size_t len;
320 	SHA1_CTX ctx;
321 	char *header = NULL;
322 	size_t headerlen;
323 	int base_obj_type;
324 	const char *obj_label;
325 
326 	deltas.nentries = 0;
327 	SIMPLEQ_INIT(&deltas.entries);
328 
329 	err = got_pack_resolve_delta_chain(&deltas, packidx, pack,
330 	    obj->off, obj->tslen, obj->type, obj->size,
331 	    GOT_DELTA_CHAIN_RECURSION_MAX);
332 	if (err)
333 		goto done;
334 
335 	/* XXX TODO reading large objects into memory is bad! */
336 	err = got_pack_dump_delta_chain_to_mem(&buf, &len, &deltas, pack);
337 	if (err)
338 		goto done;
339 
340 	SHA1Init(&ctx);
341 
342 	err = got_delta_chain_get_base_type(&base_obj_type, &deltas);
343 	if (err)
344 		goto done;
345 	err = get_obj_type_label(&obj_label, base_obj_type);
346 	if (err)
347 		goto done;
348 	if (asprintf(&header, "%s %zd", obj_label, len) == -1) {
349 		err = got_error_from_errno("asprintf");
350 		goto done;
351 	}
352 	headerlen = strlen(header) + 1;
353 	SHA1Update(&ctx, header, headerlen);
354 	SHA1Update(&ctx, buf, len);
355 	SHA1Final(obj->id.sha1, &ctx);
356 done:
357 	free(buf);
358 	free(header);
359 	while (!SIMPLEQ_EMPTY(&deltas.entries)) {
360 		delta = SIMPLEQ_FIRST(&deltas.entries);
361 		SIMPLEQ_REMOVE_HEAD(&deltas.entries, entry);
362 		free(delta);
363 	}
364 	return err;
365 }
366 
367 /* Determine the slot in the pack index a given object ID should use. */
368 static int
369 find_object_idx(struct got_packidx *packidx, uint8_t *sha1)
370 {
371 	u_int8_t id0 = sha1[0];
372 	uint32_t nindexed = betoh32(packidx->hdr.fanout_table[0xff]);
373 	int left = 0, right = nindexed - 1;
374 	int cmp = 0, i = 0;
375 
376 	if (id0 > 0)
377 		left = betoh32(packidx->hdr.fanout_table[id0 - 1]);
378 
379 	while (left <= right) {
380 		struct got_packidx_object_id *oid;
381 
382 		i = ((left + right) / 2);
383 		oid = &packidx->hdr.sorted_ids[i];
384 
385 		cmp = memcmp(sha1, oid->sha1, SHA1_DIGEST_LENGTH);
386 		if (cmp == 0)
387 			return -1; /* object already indexed */
388 		else if (cmp > 0)
389 			left = i + 1;
390 		else if (cmp < 0)
391 			right = i - 1;
392 	}
393 
394 	return left;
395 }
396 
397 #if 0
398 static void
399 print_packidx(struct got_packidx *packidx)
400 {
401 	uint32_t nindexed = betoh32(packidx->hdr.fanout_table[0xff]);
402 	int i;
403 
404 	fprintf(stderr, "object IDs:\n");
405 	for (i = 0; i < nindexed; i++) {
406 		char hex[SHA1_DIGEST_STRING_LENGTH];
407 		got_sha1_digest_to_str(packidx->hdr.sorted_ids[i].sha1,
408 		    hex, sizeof(hex));
409 		fprintf(stderr, "%s\n", hex);
410 	}
411 	fprintf(stderr, "\n");
412 
413 	fprintf(stderr, "object offsets:\n");
414 	for (i = 0; i < nindexed; i++) {
415 		uint32_t offset = be32toh(packidx->hdr.offsets[i]);
416 		if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
417 			int j = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
418 			fprintf(stderr, "%u -> %llu\n", offset, 
419 			    be64toh(packidx->hdr.large_offsets[j]));
420 		} else
421 			fprintf(stderr, "%u\n", offset);
422 	}
423 	fprintf(stderr, "\n");
424 
425 	fprintf(stderr, "fanout table:");
426 	for (i = 0; i <= 0xff; i++)
427 		fprintf(stderr, " %u", be32toh(packidx->hdr.fanout_table[i]));
428 	fprintf(stderr, "\n");
429 }
430 #endif
431 
432 static void
433 add_indexed_object(struct got_packidx *packidx, uint32_t idx,
434     struct got_indexed_object *obj)
435 {
436 	int i;
437 
438 	memcpy(packidx->hdr.sorted_ids[idx].sha1, obj->id.sha1,
439 	    SHA1_DIGEST_LENGTH);
440 	if (obj->off < GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX)
441 		packidx->hdr.offsets[idx] = htobe32(obj->off);
442 	else {
443 		packidx->hdr.offsets[idx] = htobe32(packidx->nlargeobj |
444 		    GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX);
445 		packidx->hdr.large_offsets[packidx->nlargeobj] =
446 		    htobe64(obj->off);
447 		packidx->nlargeobj++;
448 	}
449 
450 	for (i = obj->id.sha1[0]; i <= 0xff; i++) {
451 		uint32_t n = be32toh(packidx->hdr.fanout_table[i]);
452 		packidx->hdr.fanout_table[i] = htobe32(n + 1);
453 	}
454 }
455 
456 static int
457 indexed_obj_cmp(const void *pa, const void *pb)
458 {
459 	struct got_indexed_object *a, *b;
460 
461 	a = (struct got_indexed_object *)pa;
462 	b = (struct got_indexed_object *)pb;
463 	return got_object_id_cmp(&a->id, &b->id);
464 }
465 
466 static void
467 make_packidx(struct got_packidx *packidx, int nobj,
468     struct got_indexed_object *objects)
469 {
470 	struct got_indexed_object *obj;
471 	int i;
472 	uint32_t idx = 0;
473 
474 	mergesort(objects, nobj, sizeof(struct got_indexed_object),
475 	    indexed_obj_cmp);
476 
477 	memset(packidx->hdr.fanout_table, 0,
478 	    GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS * sizeof(uint32_t));
479 	packidx->nlargeobj = 0;
480 
481 	for (i = 0; i < nobj; i++) {
482 		obj = &objects[i];
483 		if (obj->valid)
484 			add_indexed_object(packidx, idx++, obj);
485 	}
486 }
487 
488 static void
489 update_packidx(struct got_packidx *packidx, int nobj,
490     struct got_indexed_object *obj)
491 {
492 	uint32_t idx;
493 	uint32_t nindexed = betoh32(packidx->hdr.fanout_table[0xff]);
494 
495 	idx = find_object_idx(packidx, obj->id.sha1);
496 	if (idx == -1) {
497 		char hex[SHA1_DIGEST_STRING_LENGTH];
498 		got_sha1_digest_to_str(obj->id.sha1, hex, sizeof(hex));
499 		return; /* object already indexed */
500 	}
501 
502 	memmove(&packidx->hdr.sorted_ids[idx + 1],
503 	    &packidx->hdr.sorted_ids[idx],
504 	    sizeof(struct got_packidx_object_id) * (nindexed - idx));
505 	memmove(&packidx->hdr.offsets[idx + 1], &packidx->hdr.offsets[idx],
506 	    sizeof(uint32_t) * (nindexed - idx));
507 
508 	add_indexed_object(packidx, idx, obj);
509 }
510 
511 static const struct got_error *
512 index_pack(struct got_pack *pack, int idxfd, uint8_t *pack_hash,
513     struct imsgbuf *ibuf)
514 {
515 	const struct got_error *err;
516 	struct got_packfile_hdr hdr;
517 	struct got_packidx packidx;
518 	char buf[8];
519 	int nobj, nvalid, nloose, nresolved = 0, i;
520 	struct got_indexed_object *objects = NULL, *obj;
521 	SHA1_CTX ctx;
522 	uint8_t packidx_hash[SHA1_DIGEST_LENGTH];
523 	ssize_t r, w;
524 	int pass, have_ref_deltas = 0;
525 	size_t mapoff = 0;
526 
527 	/* Check pack file header. */
528 	if (pack->map) {
529 		if (pack->filesize < sizeof(hdr))
530 			return got_error_msg(GOT_ERR_BAD_PACKFILE,
531 			    "short packfile header");
532 		memcpy(&hdr, pack->map, sizeof(hdr));
533 		mapoff += sizeof(hdr);
534 	} else {
535 		r = read(pack->fd, &hdr, sizeof(hdr));
536 		if (r == -1)
537 			return got_error_from_errno("read");
538 		if (r < sizeof(hdr))
539 			return got_error_msg(GOT_ERR_BAD_PACKFILE,
540 			    "short packfile header");
541 	}
542 
543 	if (hdr.signature != htobe32(GOT_PACKFILE_SIGNATURE))
544 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
545 		    "bad packfile signature");
546 	if (hdr.version != htobe32(GOT_PACKFILE_VERSION))
547 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
548 		    "bad packfile version");
549 	nobj = betoh32(hdr.nobjects);
550 	if (nobj == 0)
551 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
552 		    "bad packfile with zero objects");
553 
554 	/*
555 	 * Create an in-memory pack index which will grow as objects
556 	 * IDs in the pack file are discovered. Only fields used to
557 	 * read deltified objects will be needed by the pack.c library
558 	 * code, so setting up just a pack index header is sufficient.
559 	 */
560 	memset(&packidx, 0, sizeof(packidx));
561 	packidx.hdr.magic = malloc(sizeof(uint32_t));
562 	if (packidx.hdr.magic == NULL)
563 		return got_error_from_errno("calloc");
564 	*packidx.hdr.magic = htobe32(GOT_PACKIDX_V2_MAGIC);
565 	packidx.hdr.version = malloc(sizeof(uint32_t));
566 	if (packidx.hdr.version == NULL) {
567 		err = got_error_from_errno("malloc");
568 		goto done;
569 	}
570 	*packidx.hdr.version = htobe32(GOT_PACKIDX_VERSION);
571 	packidx.hdr.fanout_table = calloc(GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS,
572 	    sizeof(uint32_t));
573 	if (packidx.hdr.fanout_table == NULL) {
574 		err = got_error_from_errno("calloc");
575 		goto done;
576 	}
577 	packidx.hdr.sorted_ids = calloc(nobj,
578 	    sizeof(struct got_packidx_object_id));
579 	if (packidx.hdr.sorted_ids == NULL) {
580 		err = got_error_from_errno("calloc");
581 		goto done;
582 	}
583 	packidx.hdr.offsets = calloc(nobj, sizeof(uint32_t));
584 	if (packidx.hdr.offsets == NULL) {
585 		err = got_error_from_errno("calloc");
586 		goto done;
587 	}
588 	/* Large offsets table is empty for pack files < 2 GB. */
589 	if (pack->filesize >= GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
590 		packidx.hdr.large_offsets = calloc(nobj, sizeof(uint64_t));
591 		if (packidx.hdr.large_offsets == NULL) {
592 			err = got_error_from_errno("calloc");
593 			goto done;
594 		}
595 	}
596 
597 	nvalid = 0;
598 	nloose = 0;
599 	objects = calloc(nobj, sizeof(struct got_indexed_object));
600 	if (objects == NULL)
601 		return got_error_from_errno("calloc");
602 
603 	/*
604 	 * First pass: locate all objects and identify un-deltified objects.
605 	 *
606 	 * When this pass has completed we will know offset, type, size, and
607 	 * CRC information for all objects in this pack file. We won't know
608 	 * any of the actual object IDs of deltified objects yet since we
609 	 * will not yet attempt to combine deltas.
610 	 */
611 	pass = 1;
612 	for (i = 0; i < nobj; i++) {
613 		err = got_privsep_send_index_pack_progress(ibuf, nobj, i + 1,
614 		    nloose, 0);
615 		if (err)
616 			goto done;
617 
618 		obj = &objects[i];
619 		obj->crc = crc32(0L, NULL, 0);
620 
621 		/* Store offset to type+size information for this object. */
622 		if (pack->map) {
623 			obj->off = mapoff;
624 		} else {
625 			obj->off = lseek(pack->fd, 0, SEEK_CUR);
626 			if (obj->off == -1) {
627 				err = got_error_from_errno("lseek");
628 				goto done;
629 			}
630 		}
631 
632 		err = read_packed_object(pack, obj);
633 		if (err)
634 			goto done;
635 
636 		if (pack->map) {
637 			mapoff += obj->tslen + obj->len;
638 		} else {
639 			if (lseek(pack->fd, obj->off + obj->tslen + obj->len,
640 			    SEEK_SET) == -1) {
641 				err = got_error_from_errno("lseek");
642 				goto done;
643 			}
644 		}
645 
646 		if (obj->type == GOT_OBJ_TYPE_BLOB ||
647 		    obj->type == GOT_OBJ_TYPE_TREE ||
648 		    obj->type == GOT_OBJ_TYPE_COMMIT ||
649 		    obj->type == GOT_OBJ_TYPE_TAG) {
650 			obj->valid = 1;
651 			nloose++;
652 		} else if (obj->type == GOT_OBJ_TYPE_REF_DELTA)
653 			have_ref_deltas = 1;
654 	}
655 	nvalid = nloose;
656 
657 	/* In order to resolve ref deltas we need an in-progress pack index. */
658 	if (have_ref_deltas)
659 		make_packidx(&packidx, nobj, objects);
660 
661 	/*
662 	 * Second pass: We can now resolve deltas to compute the IDs of
663 	 * objects which appear in deltified form. Because deltas can be
664 	 * chained this pass may require a couple of iterations until all
665 	 * IDs of deltified objects have been discovered.
666 	 */
667 	pass++;
668 	while (nvalid != nobj) {
669 		int n = 0;
670 		for (i = 0; i < nobj; i++) {
671 			obj = &objects[i];
672 			if (obj->type != GOT_OBJ_TYPE_REF_DELTA &&
673 			    obj->type != GOT_OBJ_TYPE_OFFSET_DELTA)
674 				continue;
675 
676 			if (obj->valid)
677 				continue;
678 
679 			if (pack->map == NULL &&
680 			    lseek(pack->fd, obj->off + obj->tslen, SEEK_SET)
681 			    == -1) {
682 					err = got_error_from_errno("lseek");
683 					goto done;
684 			}
685 
686 			err = resolve_deltified_object(pack, &packidx, obj);
687 			if (err) {
688 				if (err->code != GOT_ERR_NO_OBJ)
689 					goto done;
690 				/*
691 				 * We cannot resolve this object yet because
692 				 * a delta base is unknown. Try again later.
693 				 */
694 				continue;
695 			}
696 
697 			obj->valid = 1;
698 			n++;
699 			if (have_ref_deltas)
700 				update_packidx(&packidx, nobj, obj);
701 			err = got_privsep_send_index_pack_progress(ibuf,
702 			    nobj, nobj, nloose, nresolved + n);
703 			if (err)
704 				goto done;
705 
706 		}
707 		if (pass++ > 3 && n == 0) {
708 			static char msg[64];
709 			snprintf(msg, sizeof(msg), "could not resolve "
710 			    "any of deltas; packfile could be corrupt");
711 			err = got_error_msg(GOT_ERR_BAD_PACKFILE, msg);
712 			goto done;
713 			
714 		}
715 		if (nloose + nresolved == nobj) {
716 			static char msg[64];
717 			snprintf(msg, sizeof(msg),
718 			    "fix point reached too early: %d/%d/%d",
719 			    nvalid, nresolved, nobj);
720 			err = got_error_msg(GOT_ERR_BAD_PACKFILE, msg);
721 			goto done;
722 		}
723 		nresolved += n;
724 		nvalid += nresolved;
725 	}
726 
727 	if (nloose + nresolved != nobj) {
728 		static char msg[64];
729 		snprintf(msg, sizeof(msg),
730 		    "discovered only %d of %d objects",
731 		    nloose + nresolved, nobj);
732 		err = got_error_msg(GOT_ERR_BAD_PACKFILE, msg);
733 		goto done;
734 	}
735 
736 	make_packidx(&packidx, nobj, objects);
737 
738 	SHA1Init(&ctx);
739 	putbe32(buf, GOT_PACKIDX_V2_MAGIC);
740 	putbe32(buf + 4, GOT_PACKIDX_VERSION);
741 	err = hwrite(idxfd, buf, 8, &ctx);
742 	if (err)
743 		goto done;
744 	err = hwrite(idxfd, packidx.hdr.fanout_table,
745 	    GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS * sizeof(uint32_t), &ctx);
746 	if (err)
747 		goto done;
748 	err = hwrite(idxfd, packidx.hdr.sorted_ids,
749 	    nobj * SHA1_DIGEST_LENGTH, &ctx);
750 	if (err)
751 		goto done;
752 	for(i = 0; i < nobj; i++){
753 		putbe32(buf, objects[i].crc);
754 		err = hwrite(idxfd, buf, 4, &ctx);
755 		if (err)
756 			goto done;
757 	}
758 	err = hwrite(idxfd, packidx.hdr.offsets, nobj * sizeof(uint32_t),
759 	    &ctx);
760 	if (err)
761 		goto done;
762 	if (packidx.nlargeobj > 0) {
763 		err = hwrite(idxfd, packidx.hdr.large_offsets,
764 		    packidx.nlargeobj * sizeof(uint64_t), &ctx);
765 		if (err)
766 			goto done;
767 	}
768 	err = hwrite(idxfd, pack_hash, SHA1_DIGEST_LENGTH, &ctx);
769 	if (err)
770 		goto done;
771 
772 	SHA1Final(packidx_hash, &ctx);
773 	w = write(idxfd, packidx_hash, sizeof(packidx_hash));
774 	if (w == -1) {
775 		err = got_error_from_errno("write");
776 		goto done;
777 	}
778 	if (w != sizeof(packidx_hash)) {
779 		err = got_error(GOT_ERR_IO);
780 		goto done;
781 	}
782 done:
783 	free(objects);
784 	free(packidx.hdr.magic);
785 	free(packidx.hdr.version);
786 	free(packidx.hdr.fanout_table);
787 	free(packidx.hdr.sorted_ids);
788 	free(packidx.hdr.offsets);
789 	free(packidx.hdr.large_offsets);
790 	return err;
791 }
792 
793 int
794 main(int argc, char **argv)
795 {
796 	const struct got_error *err = NULL, *close_err;
797 	struct imsgbuf ibuf;
798 	struct imsg imsg;
799 	int idxfd = -1;
800 	struct got_pack pack;
801 	uint8_t pack_hash[SHA1_DIGEST_LENGTH];
802 	off_t packfile_size;
803 #if 0
804 	static int attached;
805 	while (!attached)
806 		sleep(1);
807 #endif
808 
809 	memset(&pack, 0, sizeof(pack));
810 	pack.fd = -1;
811 	pack.delta_cache = got_delta_cache_alloc(100,
812 	    GOT_DELTA_RESULT_SIZE_CACHED_MAX);
813 	if (pack.delta_cache == NULL) {
814 		err = got_error_from_errno("got_delta_cache_alloc");
815 		goto done;
816 	}
817 
818 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
819 #ifndef PROFILE
820 	/* revoke access to most system calls */
821 	if (pledge("stdio recvfd", NULL) == -1) {
822 		err = got_error_from_errno("pledge");
823 		got_privsep_send_error(&ibuf, err);
824 		return 1;
825 	}
826 #endif
827 	err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
828 	if (err)
829 		goto done;
830 	if (imsg.hdr.type == GOT_IMSG_STOP)
831 		goto done;
832 	if (imsg.hdr.type != GOT_IMSG_IDXPACK_REQUEST) {
833 		err = got_error(GOT_ERR_PRIVSEP_MSG);
834 		goto done;
835 	}
836 	if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(pack_hash)) {
837 		err = got_error(GOT_ERR_PRIVSEP_LEN);
838 		goto done;
839 	}
840 	memcpy(pack_hash, imsg.data, sizeof(pack_hash));
841 	pack.fd = imsg.fd;
842 
843 	err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
844 	if (err)
845 		goto done;
846 	if (imsg.hdr.type == GOT_IMSG_STOP)
847 		goto done;
848 	if (imsg.hdr.type != GOT_IMSG_TMPFD) {
849 		err = got_error(GOT_ERR_PRIVSEP_MSG);
850 		goto done;
851 	}
852 	if (imsg.hdr.len - IMSG_HEADER_SIZE != 0) {
853 		err = got_error(GOT_ERR_PRIVSEP_LEN);
854 		goto done;
855 	}
856 	idxfd = imsg.fd;
857 
858 	if (lseek(pack.fd, 0, SEEK_END) == -1) {
859 		err = got_error_from_errno("lseek");
860 		goto done;
861 	}
862 	packfile_size = lseek(pack.fd, 0, SEEK_CUR);
863 	if (packfile_size == -1) {
864 		err = got_error_from_errno("lseek");
865 		goto done;
866 	}
867 	pack.filesize = packfile_size; /* XXX off_t vs size_t */
868 
869 	if (lseek(pack.fd, 0, SEEK_SET) == -1) {
870 		err = got_error_from_errno("lseek");
871 		goto done;
872 	}
873 
874 #ifndef GOT_PACK_NO_MMAP
875 	pack.map = mmap(NULL, pack.filesize, PROT_READ, MAP_PRIVATE,
876 	    pack.fd, 0);
877 	if (pack.map == MAP_FAILED)
878 		pack.map = NULL; /* fall back to read(2) */
879 #endif
880 	err = index_pack(&pack, idxfd, pack_hash, &ibuf);
881 done:
882 	close_err = got_pack_close(&pack);
883 	if (close_err && err == NULL)
884 		err = close_err;
885 	if (idxfd != -1 && close(idxfd) == -1 && err == NULL)
886 		err = got_error_from_errno("close");
887 
888 	if (err == NULL)
889 		err = got_privsep_send_index_pack_done(&ibuf);
890 	if (err) {
891 		got_privsep_send_error(&ibuf, err);
892 		fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
893 		got_privsep_send_error(&ibuf, err);
894 		exit(1);
895 	}
896 
897 	exit(0);
898 }