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 <endian.h>
37 #include <fcntl.h>
38 #include <unistd.h>
39 #include <zlib.h>
40 #include <err.h>
41 #include <assert.h>
42 #include <dirent.h>
43 
44 #include "got_error.h"
45 #include "got_object.h"
46 
47 #include "got_lib_sha1.h"
48 #include "got_lib_delta.h"
49 #include "got_lib_inflate.h"
50 #include "got_lib_object.h"
51 #include "got_lib_object_parse.h"
52 #include "got_lib_object_idset.h"
53 #include "got_lib_privsep.h"
54 #include "got_lib_pack.h"
55 #include "got_lib_delta_cache.h"
56 
57 #ifndef nitems
58 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
59 #endif
60 
61 struct got_indexed_object {
62 	struct got_object_id id;
63 
64 	/*
65 	 * Has this object been fully resolved?
66 	 * If so, we know its ID, otherwise we don't and 'id' is invalid.
67 	 */
68 	int valid;
69 
70 	/* Offset of type+size field for this object in pack file. */
71 	off_t off;
72 
73 	/* Type+size values parsed from pack file. */
74 	uint8_t type;
75 	uint64_t size;
76 
77 	/* Length of on-disk type+size data. */
78 	size_t tslen; 
79 
80 	/* Length of object data following type+size. */
81 	size_t len; 
82 
83 	uint32_t crc;
84 
85 	union {
86 		struct {
87 			/* For ref deltas. */
88 			struct got_object_id ref_id;
89 		} ref;
90 		struct {
91 			/* For offset deltas. */
92 			off_t base_offset;
93 			size_t base_offsetlen;
94 		} ofs;
95 	} delta;
96 };
97 
98 static void
99 putbe32(char *b, uint32_t n)
100 {
101 	b[0] = n >> 24;
102 	b[1] = n >> 16;
103 	b[2] = n >> 8;
104 	b[3] = n >> 0;
105 }
106 
107 static const struct got_error *
108 get_obj_type_label(const char **label, int obj_type)
109 {
110 	const struct got_error *err = NULL;
111 
112 	switch (obj_type) {
113 	case GOT_OBJ_TYPE_BLOB:
114 		*label = GOT_OBJ_LABEL_BLOB;
115 		break;
116 	case GOT_OBJ_TYPE_TREE:
117 		*label = GOT_OBJ_LABEL_TREE;
118 		break;
119 	case GOT_OBJ_TYPE_COMMIT:
120 		*label = GOT_OBJ_LABEL_COMMIT;
121 		break;
122 	case GOT_OBJ_TYPE_TAG:
123 		*label = GOT_OBJ_LABEL_TAG;
124 		break;
125 	default:
126 		*label = NULL;
127 		err = got_error(GOT_ERR_OBJ_TYPE);
128 		break;
129 	}
130 
131 	return err;
132 }
133 
134 static const struct got_error *
135 read_checksum(uint32_t *crc, SHA1_CTX *sha1_ctx, int fd, size_t len)
136 {
137 	uint8_t buf[8192];
138 	size_t n;
139 	ssize_t r;
140 
141 	for (n = len; n > 0; n -= r){
142 		r = read(fd, buf, n > sizeof(buf) ? sizeof(buf) : n);
143 		if (r == -1)
144 			return got_error_from_errno("read");
145 		if (r == 0)
146 			break;
147 		if (crc)
148 			*crc = crc32(*crc, buf, r);
149 		if (sha1_ctx)
150 			SHA1Update(sha1_ctx, buf, r);
151 	}
152 
153 	return NULL;
154 }
155 
156 static const struct got_error *
157 read_file_sha1(SHA1_CTX *ctx, FILE *f, size_t len)
158 {
159 	uint8_t buf[8192];
160 	size_t n, r;
161 
162 	for (n = len; n > 0; n -= r) {
163 		r = fread(buf, 1, n > sizeof(buf) ? sizeof(buf) : n, f);
164 		if (r == 0) {
165 			if (feof(f))
166 				return NULL;
167 			return got_ferror(f, GOT_ERR_IO);
168 		}
169 		SHA1Update(ctx, buf, r);
170 	}
171 
172 	return NULL;
173 }
174 
175 static const struct got_error *
176 read_packed_object(struct got_pack *pack, struct got_indexed_object *obj,
177     FILE *tmpfile, SHA1_CTX *pack_sha1_ctx)
178 {
179 	const struct got_error *err = NULL;
180 	SHA1_CTX ctx;
181 	uint8_t *data = NULL;
182 	size_t datalen = 0;
183 	ssize_t n;
184 	char *header;
185 	size_t headerlen;
186 	const char *obj_label;
187 	size_t mapoff = obj->off;
188 	struct got_inflate_checksum csum;
189 
190 	csum.input_sha1 = pack_sha1_ctx;
191 	csum.input_crc = &obj->crc;
192 
193 	err = got_pack_parse_object_type_and_size(&obj->type, &obj->size,
194 	    &obj->tslen, pack, obj->off);
195 	if (err)
196 		return err;
197 
198 	if (pack->map) {
199 		obj->crc = crc32(obj->crc, pack->map + mapoff, obj->tslen);
200 		SHA1Update(pack_sha1_ctx, pack->map + mapoff, obj->tslen);
201 		mapoff += obj->tslen;
202 	} else {
203 		/* XXX Seek back and get the CRC of on-disk type+size bytes. */
204 		if (lseek(pack->fd, obj->off, SEEK_SET) == -1)
205 			return got_error_from_errno("lseek");
206 		err = read_checksum(&obj->crc, pack_sha1_ctx,
207 		    pack->fd, obj->tslen);
208 		if (err)
209 			return err;
210 	}
211 
212 	switch (obj->type) {
213 	case GOT_OBJ_TYPE_BLOB:
214 	case GOT_OBJ_TYPE_COMMIT:
215 	case GOT_OBJ_TYPE_TREE:
216 	case GOT_OBJ_TYPE_TAG:
217 		if (obj->size > GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
218 			if (fseek(tmpfile, 0L, SEEK_SET) == -1) {
219 				err = got_error_from_errno("fseek");
220 				break;
221 			}
222 			if (pack->map) {
223 				err = got_inflate_to_file_mmap(&datalen,
224 				    &obj->len, &csum, pack->map, mapoff,
225 				    pack->filesize - mapoff, tmpfile);
226 			} else {
227 				err = got_inflate_to_file_fd(&datalen,
228 				    &obj->len, &csum, pack->fd, tmpfile);
229 			}
230 		} else {
231 			if (pack->map) {
232 				err = got_inflate_to_mem_mmap(&data, &datalen,
233 				    &obj->len, &csum, pack->map, mapoff,
234 				    pack->filesize - mapoff);
235 			} else {
236 				err = got_inflate_to_mem_fd(&data, &datalen,
237 				    &obj->len, &csum, obj->size, pack->fd);
238 			}
239 		}
240 		if (err)
241 			break;
242 		SHA1Init(&ctx);
243 		err = get_obj_type_label(&obj_label, obj->type);
244 		if (err) {
245 			free(data);
246 			break;
247 		}
248 		if (asprintf(&header, "%s %lld", obj_label, obj->size) == -1) {
249 			err = got_error_from_errno("asprintf");
250 			free(data);
251 			break;
252 		}
253 		headerlen = strlen(header) + 1;
254 		SHA1Update(&ctx, header, headerlen);
255 		if (obj->size > GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
256 			err = read_file_sha1(&ctx, tmpfile, datalen);
257 			if (err)
258 				break;
259 		} else
260 			SHA1Update(&ctx, data, datalen);
261 		SHA1Final(obj->id.sha1, &ctx);
262 		free(header);
263 		free(data);
264 		break;
265 	case GOT_OBJ_TYPE_REF_DELTA:
266 		memset(obj->id.sha1, 0xff, SHA1_DIGEST_LENGTH);
267 		if (pack->map) {
268 			if (mapoff + SHA1_DIGEST_LENGTH >= pack->filesize) {
269 				err = got_error(GOT_ERR_BAD_PACKFILE);
270 				break;
271 			}
272 			memcpy(obj->delta.ref.ref_id.sha1, pack->map + mapoff,
273 			    SHA1_DIGEST_LENGTH);
274 			obj->crc = crc32(obj->crc, pack->map + mapoff,
275 			    SHA1_DIGEST_LENGTH);
276 			SHA1Update(pack_sha1_ctx, pack->map + mapoff,
277 			    SHA1_DIGEST_LENGTH);
278 			mapoff += SHA1_DIGEST_LENGTH;
279 			err = got_inflate_to_mem_mmap(NULL, &datalen,
280 			    &obj->len, &csum, pack->map, mapoff,
281 			    pack->filesize - mapoff);
282 			if (err)
283 				break;
284 		} else {
285 			n = read(pack->fd, obj->delta.ref.ref_id.sha1,
286 			    SHA1_DIGEST_LENGTH);
287 			if (n == -1) {
288 				err = got_error_from_errno("read");
289 				break;
290 			}
291 			if (n < sizeof(obj->id)) {
292 				err = got_error(GOT_ERR_BAD_PACKFILE);
293 				break;
294 			}
295 			obj->crc = crc32(obj->crc, obj->delta.ref.ref_id.sha1,
296 			    SHA1_DIGEST_LENGTH);
297 			SHA1Update(pack_sha1_ctx, obj->delta.ref.ref_id.sha1,
298 			    SHA1_DIGEST_LENGTH);
299 			err = got_inflate_to_mem_fd(NULL, &datalen, &obj->len,
300 			    &csum, obj->size, pack->fd);
301 			if (err)
302 				break;
303 		}
304 		obj->len += SHA1_DIGEST_LENGTH;
305 		break;
306 	case GOT_OBJ_TYPE_OFFSET_DELTA:
307 		memset(obj->id.sha1, 0xff, SHA1_DIGEST_LENGTH);
308 		err = got_pack_parse_offset_delta(&obj->delta.ofs.base_offset,
309 		    &obj->delta.ofs.base_offsetlen, pack, obj->off,
310 		    obj->tslen);
311 		if (err)
312 			break;
313 
314 		if (pack->map) {
315 			obj->crc = crc32(obj->crc, pack->map + mapoff,
316 			    obj->delta.ofs.base_offsetlen);
317 			SHA1Update(pack_sha1_ctx, pack->map + mapoff,
318 			    obj->delta.ofs.base_offsetlen);
319 			mapoff += obj->delta.ofs.base_offsetlen;
320 			err = got_inflate_to_mem_mmap(NULL, &datalen,
321 			    &obj->len, &csum, pack->map, mapoff,
322 			    pack->filesize - mapoff);
323 			if (err)
324 				break;
325 		} else {
326 			/*
327 			 * XXX Seek back and get CRC and SHA1 of on-disk
328 			 * offset bytes.
329 			 */
330 			if (lseek(pack->fd, obj->off + obj->tslen, SEEK_SET)
331 			    == -1) {
332 				err = got_error_from_errno("lseek");
333 				break;
334 			}
335 			err = read_checksum(&obj->crc, pack_sha1_ctx,
336 			    pack->fd, obj->delta.ofs.base_offsetlen);
337 			if (err)
338 				break;
339 
340 			err = got_inflate_to_mem_fd(NULL, &datalen, &obj->len,
341 			    &csum, obj->size, pack->fd);
342 			if (err)
343 				break;
344 		}
345 		obj->len += obj->delta.ofs.base_offsetlen;
346 		break;
347 	default:
348 		err = got_error(GOT_ERR_OBJ_TYPE);
349 		break;
350 	}
351 
352 	return err;
353 }
354 
355 static const struct got_error *
356 hwrite(int fd, void *buf, int len, SHA1_CTX *ctx)
357 {
358 	ssize_t w;
359 
360 	SHA1Update(ctx, buf, len);
361 
362 	w = write(fd, buf, len);
363 	if (w == -1)
364 		return got_error_from_errno("write");
365 	if (w != len)
366 		return got_error(GOT_ERR_IO);
367 
368 	return NULL;
369 }
370 
371 static const struct got_error *
372 resolve_deltified_object(struct got_pack *pack, struct got_packidx *packidx,
373     struct got_indexed_object *obj, FILE *tmpfile, FILE *delta_base_file,
374     FILE *delta_accum_file)
375 {
376 	const struct got_error *err = NULL;
377 	struct got_delta_chain deltas;
378 	struct got_delta *delta;
379 	uint8_t *buf = NULL;
380 	size_t len = 0;
381 	SHA1_CTX ctx;
382 	char *header = NULL;
383 	size_t headerlen;
384 	uint64_t max_size;
385 	int base_obj_type;
386 	const char *obj_label;
387 
388 	deltas.nentries = 0;
389 	SIMPLEQ_INIT(&deltas.entries);
390 
391 	err = got_pack_resolve_delta_chain(&deltas, packidx, pack,
392 	    obj->off, obj->tslen, obj->type, obj->size,
393 	    GOT_DELTA_CHAIN_RECURSION_MAX);
394 	if (err)
395 		goto done;
396 
397 	err = got_pack_get_delta_chain_max_size(&max_size, &deltas, pack);
398 	if (err)
399 		goto done;
400 	if (max_size > GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
401 		rewind(tmpfile);
402 		rewind(delta_base_file);
403 		rewind(delta_accum_file);
404 		err = got_pack_dump_delta_chain_to_file(&len, &deltas,
405 		    pack, tmpfile, delta_base_file, delta_accum_file);
406 		if (err)
407 			goto done;
408 	} else {
409 		err = got_pack_dump_delta_chain_to_mem(&buf, &len,
410 		    &deltas, pack);
411 	}
412 	if (err)
413 		goto done;
414 
415 	err = got_delta_chain_get_base_type(&base_obj_type, &deltas);
416 	if (err)
417 		goto done;
418 	err = get_obj_type_label(&obj_label, base_obj_type);
419 	if (err)
420 		goto done;
421 	if (asprintf(&header, "%s %zd", obj_label, len) == -1) {
422 		err = got_error_from_errno("asprintf");
423 		goto done;
424 	}
425 	headerlen = strlen(header) + 1;
426 	SHA1Init(&ctx);
427 	SHA1Update(&ctx, header, headerlen);
428 	if (max_size > GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
429 		err = read_file_sha1(&ctx, tmpfile, len);
430 		if (err)
431 			goto done;
432 	} else
433 		SHA1Update(&ctx, buf, len);
434 	SHA1Final(obj->id.sha1, &ctx);
435 done:
436 	free(buf);
437 	free(header);
438 	while (!SIMPLEQ_EMPTY(&deltas.entries)) {
439 		delta = SIMPLEQ_FIRST(&deltas.entries);
440 		SIMPLEQ_REMOVE_HEAD(&deltas.entries, entry);
441 		free(delta);
442 	}
443 	return err;
444 }
445 
446 /* Determine the slot in the pack index a given object ID should use. */
447 static int
448 find_object_idx(struct got_packidx *packidx, uint8_t *sha1)
449 {
450 	u_int8_t id0 = sha1[0];
451 	uint32_t nindexed = be32toh(packidx->hdr.fanout_table[0xff]);
452 	int left = 0, right = nindexed - 1;
453 	int cmp = 0, i = 0;
454 
455 	if (id0 > 0)
456 		left = be32toh(packidx->hdr.fanout_table[id0 - 1]);
457 
458 	while (left <= right) {
459 		struct got_packidx_object_id *oid;
460 
461 		i = ((left + right) / 2);
462 		oid = &packidx->hdr.sorted_ids[i];
463 
464 		cmp = memcmp(sha1, oid->sha1, SHA1_DIGEST_LENGTH);
465 		if (cmp == 0)
466 			return -1; /* object already indexed */
467 		else if (cmp > 0)
468 			left = i + 1;
469 		else if (cmp < 0)
470 			right = i - 1;
471 	}
472 
473 	return left;
474 }
475 
476 #if 0
477 static void
478 print_packidx(struct got_packidx *packidx)
479 {
480 	uint32_t nindexed = be32toh(packidx->hdr.fanout_table[0xff]);
481 	int i;
482 
483 	fprintf(stderr, "object IDs:\n");
484 	for (i = 0; i < nindexed; i++) {
485 		char hex[SHA1_DIGEST_STRING_LENGTH];
486 		got_sha1_digest_to_str(packidx->hdr.sorted_ids[i].sha1,
487 		    hex, sizeof(hex));
488 		fprintf(stderr, "%s\n", hex);
489 	}
490 	fprintf(stderr, "\n");
491 
492 	fprintf(stderr, "object offsets:\n");
493 	for (i = 0; i < nindexed; i++) {
494 		uint32_t offset = be32toh(packidx->hdr.offsets[i]);
495 		if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
496 			int j = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
497 			fprintf(stderr, "%u -> %llu\n", offset, 
498 			    be64toh(packidx->hdr.large_offsets[j]));
499 		} else
500 			fprintf(stderr, "%u\n", offset);
501 	}
502 	fprintf(stderr, "\n");
503 
504 	fprintf(stderr, "fanout table:");
505 	for (i = 0; i <= 0xff; i++)
506 		fprintf(stderr, " %u", be32toh(packidx->hdr.fanout_table[i]));
507 	fprintf(stderr, "\n");
508 }
509 #endif
510 
511 static void
512 add_indexed_object(struct got_packidx *packidx, uint32_t idx,
513     struct got_indexed_object *obj)
514 {
515 	int i;
516 
517 	memcpy(packidx->hdr.sorted_ids[idx].sha1, obj->id.sha1,
518 	    SHA1_DIGEST_LENGTH);
519 	packidx->hdr.crc32[idx] = htobe32(obj->crc);
520 	if (obj->off < GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX)
521 		packidx->hdr.offsets[idx] = htobe32(obj->off);
522 	else {
523 		packidx->hdr.offsets[idx] = htobe32(packidx->nlargeobj |
524 		    GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX);
525 		packidx->hdr.large_offsets[packidx->nlargeobj] =
526 		    htobe64(obj->off);
527 		packidx->nlargeobj++;
528 	}
529 
530 	for (i = obj->id.sha1[0]; i <= 0xff; i++) {
531 		uint32_t n = be32toh(packidx->hdr.fanout_table[i]);
532 		packidx->hdr.fanout_table[i] = htobe32(n + 1);
533 	}
534 }
535 
536 static int
537 indexed_obj_cmp(const void *pa, const void *pb)
538 {
539 	struct got_indexed_object *a, *b;
540 
541 	a = (struct got_indexed_object *)pa;
542 	b = (struct got_indexed_object *)pb;
543 	return got_object_id_cmp(&a->id, &b->id);
544 }
545 
546 static void
547 make_packidx(struct got_packidx *packidx, int nobj,
548     struct got_indexed_object *objects)
549 {
550 	struct got_indexed_object *obj;
551 	int i;
552 	uint32_t idx = 0;
553 
554 	qsort(objects, nobj, sizeof(struct got_indexed_object),
555 	    indexed_obj_cmp);
556 
557 	memset(packidx->hdr.fanout_table, 0,
558 	    GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS * sizeof(uint32_t));
559 	packidx->nlargeobj = 0;
560 
561 	for (i = 0; i < nobj; i++) {
562 		obj = &objects[i];
563 		if (obj->valid)
564 			add_indexed_object(packidx, idx++, obj);
565 	}
566 }
567 
568 static void
569 update_packidx(struct got_packidx *packidx, int nobj,
570     struct got_indexed_object *obj)
571 {
572 	uint32_t idx;
573 	uint32_t nindexed = be32toh(packidx->hdr.fanout_table[0xff]);
574 
575 	idx = find_object_idx(packidx, obj->id.sha1);
576 	if (idx == -1) {
577 		char hex[SHA1_DIGEST_STRING_LENGTH];
578 		got_sha1_digest_to_str(obj->id.sha1, hex, sizeof(hex));
579 		return; /* object already indexed */
580 	}
581 
582 	memmove(&packidx->hdr.sorted_ids[idx + 1],
583 	    &packidx->hdr.sorted_ids[idx],
584 	    sizeof(struct got_packidx_object_id) * (nindexed - idx));
585 	memmove(&packidx->hdr.offsets[idx + 1], &packidx->hdr.offsets[idx],
586 	    sizeof(uint32_t) * (nindexed - idx));
587 
588 	add_indexed_object(packidx, idx, obj);
589 }
590 
591 static const struct got_error *
592 send_index_pack_progress(struct imsgbuf *ibuf, int nobj_total,
593     int nobj_indexed, int nobj_loose, int nobj_resolved)
594 {
595 	struct got_imsg_index_pack_progress iprogress;
596 
597 	iprogress.nobj_total = nobj_total;
598 	iprogress.nobj_indexed = nobj_indexed;
599 	iprogress.nobj_loose = nobj_loose;
600 	iprogress.nobj_resolved = nobj_resolved;
601 
602 	if (imsg_compose(ibuf, GOT_IMSG_IDXPACK_PROGRESS, 0, 0, -1,
603 	    &iprogress, sizeof(iprogress)) == -1)
604 		return got_error_from_errno("imsg_compose IDXPACK_PROGRESS");
605 
606 	return got_privsep_flush_imsg(ibuf);
607 }
608 
609 static const struct got_error *
610 send_index_pack_done(struct imsgbuf *ibuf)
611 {
612 	if (imsg_compose(ibuf, GOT_IMSG_IDXPACK_DONE, 0, 0, -1, NULL, 0) == -1)
613 		return got_error_from_errno("imsg_compose FETCH");
614 	return got_privsep_flush_imsg(ibuf);
615 }
616 
617 
618 static const struct got_error *
619 index_pack(struct got_pack *pack, int idxfd, FILE *tmpfile,
620     FILE *delta_base_file, FILE *delta_accum_file, uint8_t *pack_sha1_expected,
621     struct imsgbuf *ibuf)
622 {
623 	const struct got_error *err;
624 	struct got_packfile_hdr hdr;
625 	struct got_packidx packidx;
626 	char buf[8];
627 	char pack_sha1[SHA1_DIGEST_LENGTH];
628 	int nobj, nvalid, nloose, nresolved = 0, i;
629 	struct got_indexed_object *objects = NULL, *obj;
630 	SHA1_CTX ctx;
631 	uint8_t packidx_hash[SHA1_DIGEST_LENGTH];
632 	ssize_t r, w;
633 	int pass, have_ref_deltas = 0, first_delta_idx = -1;
634 	size_t mapoff = 0;
635 	int p_indexed = 0, last_p_indexed = -1;
636 	int p_resolved = 0, last_p_resolved = -1;
637 
638 	/* Require that pack file header and SHA1 trailer are present. */
639 	if (pack->filesize < sizeof(hdr) + SHA1_DIGEST_LENGTH)
640 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
641 		    "short pack file");
642 
643 	if (pack->map) {
644 		memcpy(&hdr, pack->map, sizeof(hdr));
645 		mapoff += sizeof(hdr);
646 	} else {
647 		r = read(pack->fd, &hdr, sizeof(hdr));
648 		if (r == -1)
649 			return got_error_from_errno("read");
650 		if (r < sizeof(hdr))
651 			return got_error_msg(GOT_ERR_BAD_PACKFILE,
652 			    "short pack file");
653 	}
654 
655 	if (hdr.signature != htobe32(GOT_PACKFILE_SIGNATURE))
656 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
657 		    "bad packfile signature");
658 	if (hdr.version != htobe32(GOT_PACKFILE_VERSION))
659 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
660 		    "bad packfile version");
661 	nobj = be32toh(hdr.nobjects);
662 	if (nobj == 0)
663 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
664 		    "bad packfile with zero objects");
665 
666 	/* We compute the SHA1 of pack file contents and verify later on. */
667 	SHA1Init(&ctx);
668 	SHA1Update(&ctx, (void *)&hdr, sizeof(hdr));
669 
670 	/*
671 	 * Create an in-memory pack index which will grow as objects
672 	 * IDs in the pack file are discovered. Only fields used to
673 	 * read deltified objects will be needed by the pack.c library
674 	 * code, so setting up just a pack index header is sufficient.
675 	 */
676 	memset(&packidx, 0, sizeof(packidx));
677 	packidx.hdr.magic = malloc(sizeof(uint32_t));
678 	if (packidx.hdr.magic == NULL)
679 		return got_error_from_errno("calloc");
680 	*packidx.hdr.magic = htobe32(GOT_PACKIDX_V2_MAGIC);
681 	packidx.hdr.version = malloc(sizeof(uint32_t));
682 	if (packidx.hdr.version == NULL) {
683 		err = got_error_from_errno("malloc");
684 		goto done;
685 	}
686 	*packidx.hdr.version = htobe32(GOT_PACKIDX_VERSION);
687 	packidx.hdr.fanout_table = calloc(GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS,
688 	    sizeof(uint32_t));
689 	if (packidx.hdr.fanout_table == NULL) {
690 		err = got_error_from_errno("calloc");
691 		goto done;
692 	}
693 	packidx.hdr.sorted_ids = calloc(nobj,
694 	    sizeof(struct got_packidx_object_id));
695 	if (packidx.hdr.sorted_ids == NULL) {
696 		err = got_error_from_errno("calloc");
697 		goto done;
698 	}
699 	packidx.hdr.crc32 = calloc(nobj, sizeof(uint32_t));
700 	if (packidx.hdr.crc32 == NULL) {
701 		err = got_error_from_errno("calloc");
702 		goto done;
703 	}
704 	packidx.hdr.offsets = calloc(nobj, sizeof(uint32_t));
705 	if (packidx.hdr.offsets == NULL) {
706 		err = got_error_from_errno("calloc");
707 		goto done;
708 	}
709 	/* Large offsets table is empty for pack files < 2 GB. */
710 	if (pack->filesize >= GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
711 		packidx.hdr.large_offsets = calloc(nobj, sizeof(uint64_t));
712 		if (packidx.hdr.large_offsets == NULL) {
713 			err = got_error_from_errno("calloc");
714 			goto done;
715 		}
716 	}
717 
718 	nvalid = 0;
719 	nloose = 0;
720 	objects = calloc(nobj, sizeof(struct got_indexed_object));
721 	if (objects == NULL)
722 		return got_error_from_errno("calloc");
723 
724 	/*
725 	 * First pass: locate all objects and identify un-deltified objects.
726 	 *
727 	 * When this pass has completed we will know offset, type, size, and
728 	 * CRC information for all objects in this pack file. We won't know
729 	 * any of the actual object IDs of deltified objects yet since we
730 	 * will not yet attempt to combine deltas.
731 	 */
732 	pass = 1;
733 	for (i = 0; i < nobj; i++) {
734 		/* Don't send too many progress privsep messages. */
735 		p_indexed = ((i + 1) * 100) / nobj;
736 		if (p_indexed != last_p_indexed) {
737 			err = send_index_pack_progress(ibuf, nobj, i + 1,
738 			    nloose, 0);
739 			if (err)
740 				goto done;
741 			last_p_indexed = p_indexed;
742 		}
743 
744 		obj = &objects[i];
745 		obj->crc = crc32(0L, NULL, 0);
746 
747 		/* Store offset to type+size information for this object. */
748 		if (pack->map) {
749 			obj->off = mapoff;
750 		} else {
751 			obj->off = lseek(pack->fd, 0, SEEK_CUR);
752 			if (obj->off == -1) {
753 				err = got_error_from_errno("lseek");
754 				goto done;
755 			}
756 		}
757 
758 		err = read_packed_object(pack, obj, tmpfile, &ctx);
759 		if (err)
760 			goto done;
761 
762 		if (pack->map) {
763 			mapoff += obj->tslen + obj->len;
764 		} else {
765 			if (lseek(pack->fd, obj->off + obj->tslen + obj->len,
766 			    SEEK_SET) == -1) {
767 				err = got_error_from_errno("lseek");
768 				goto done;
769 			}
770 		}
771 
772 		if (obj->type == GOT_OBJ_TYPE_BLOB ||
773 		    obj->type == GOT_OBJ_TYPE_TREE ||
774 		    obj->type == GOT_OBJ_TYPE_COMMIT ||
775 		    obj->type == GOT_OBJ_TYPE_TAG) {
776 			obj->valid = 1;
777 			nloose++;
778 		} else {
779 			if (first_delta_idx == -1)
780 				first_delta_idx = i;
781 			if (obj->type == GOT_OBJ_TYPE_REF_DELTA)
782 				have_ref_deltas = 1;
783 		}
784 	}
785 	nvalid = nloose;
786 
787 	/*
788 	 * Having done a full pass over the pack file and can now
789 	 * verify its checksum.
790 	 */
791 	SHA1Final(pack_sha1, &ctx);
792 	if (memcmp(pack_sha1_expected, pack_sha1, SHA1_DIGEST_LENGTH) != 0) {
793 		err = got_error_msg(GOT_ERR_BAD_PACKFILE,
794 		    "pack file checksum mismatch");
795 		goto done;
796 	}
797 
798 	/* Verify the SHA1 checksum stored at the end of the pack file. */
799 	if (pack->map) {
800 		memcpy(pack_sha1_expected, pack->map +
801 		    pack->filesize - SHA1_DIGEST_LENGTH,
802 		    SHA1_DIGEST_LENGTH);
803 	} else {
804 		ssize_t n;
805 		if (lseek(pack->fd, -SHA1_DIGEST_LENGTH, SEEK_END) == -1) {
806 			err = got_error_from_errno("lseek");
807 			goto done;
808 		}
809 		n = read(pack->fd, pack_sha1_expected, SHA1_DIGEST_LENGTH);
810 		if (n == -1) {
811 			err = got_error_from_errno("read");
812 			goto done;
813 		}
814 		if (n != SHA1_DIGEST_LENGTH) {
815 			err = got_error(GOT_ERR_IO);
816 			goto done;
817 		}
818 	}
819 	if (memcmp(pack_sha1, pack_sha1_expected, SHA1_DIGEST_LENGTH) != 0) {
820 		err = got_error_msg(GOT_ERR_BAD_PACKFILE,
821 		    "bad checksum in pack file trailer");
822 		goto done;
823 	}
824 
825 	if (first_delta_idx == -1)
826 		first_delta_idx = 0;
827 
828 	/* In order to resolve ref deltas we need an in-progress pack index. */
829 	if (have_ref_deltas)
830 		make_packidx(&packidx, nobj, objects);
831 
832 	/*
833 	 * Second pass: We can now resolve deltas to compute the IDs of
834 	 * objects which appear in deltified form. Because deltas can be
835 	 * chained this pass may require a couple of iterations until all
836 	 * IDs of deltified objects have been discovered.
837 	 */
838 	pass++;
839 	while (nvalid != nobj) {
840 		int n = 0;
841 		/*
842 		 * This loop will only run once unless the pack file
843 		 * contains ref deltas which refer to objects located
844 		 * later in the pack file, which is unusual.
845 		 * Offset deltas can always be resolved in one pass
846 		 * unless the packfile is corrupt.
847 		 */
848 		for (i = first_delta_idx; i < nobj; i++) {
849 			obj = &objects[i];
850 			if (obj->type != GOT_OBJ_TYPE_REF_DELTA &&
851 			    obj->type != GOT_OBJ_TYPE_OFFSET_DELTA)
852 				continue;
853 
854 			if (obj->valid)
855 				continue;
856 
857 			if (pack->map == NULL && lseek(pack->fd,
858 			    obj->off + obj->tslen, SEEK_SET) == -1) {
859 				err = got_error_from_errno("lseek");
860 				goto done;
861 			}
862 
863 			err = resolve_deltified_object(pack, &packidx, obj,
864 			    tmpfile, delta_base_file, delta_accum_file);
865 			if (err) {
866 				if (err->code != GOT_ERR_NO_OBJ)
867 					goto done;
868 				/*
869 				 * We cannot resolve this object yet because
870 				 * a delta base is unknown. Try again later.
871 				 */
872 				continue;
873 			}
874 
875 			obj->valid = 1;
876 			n++;
877 			if (have_ref_deltas)
878 				update_packidx(&packidx, nobj, obj);
879 			/* Don't send too many progress privsep messages. */
880 			p_resolved = ((nresolved + n) * 100) / nobj;
881 			if (p_resolved != last_p_resolved) {
882 				err = send_index_pack_progress(ibuf, nobj,
883 				    nobj, nloose, nresolved + n);
884 				if (err)
885 					goto done;
886 				last_p_resolved = p_resolved;
887 			}
888 
889 		}
890 		if (pass++ > 3 && n == 0) {
891 			static char msg[64];
892 			snprintf(msg, sizeof(msg), "could not resolve "
893 			    "any of deltas; packfile could be corrupt");
894 			err = got_error_msg(GOT_ERR_BAD_PACKFILE, msg);
895 			goto done;
896 			
897 		}
898 		nresolved += n;
899 		nvalid += nresolved;
900 	}
901 
902 	if (nloose + nresolved != nobj) {
903 		static char msg[64];
904 		snprintf(msg, sizeof(msg), "discovered only %d of %d objects",
905 		    nloose + nresolved, nobj);
906 		err = got_error_msg(GOT_ERR_BAD_PACKFILE, msg);
907 		goto done;
908 	}
909 
910 	err = send_index_pack_progress(ibuf, nobj, nobj, nloose, nresolved);
911 	if (err)
912 		goto done;
913 
914 	make_packidx(&packidx, nobj, objects);
915 
916 	free(objects);
917 	objects = NULL;
918 
919 	SHA1Init(&ctx);
920 	putbe32(buf, GOT_PACKIDX_V2_MAGIC);
921 	putbe32(buf + 4, GOT_PACKIDX_VERSION);
922 	err = hwrite(idxfd, buf, 8, &ctx);
923 	if (err)
924 		goto done;
925 	err = hwrite(idxfd, packidx.hdr.fanout_table,
926 	    GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS * sizeof(uint32_t), &ctx);
927 	if (err)
928 		goto done;
929 	err = hwrite(idxfd, packidx.hdr.sorted_ids,
930 	    nobj * SHA1_DIGEST_LENGTH, &ctx);
931 	if (err)
932 		goto done;
933 	err = hwrite(idxfd, packidx.hdr.crc32, nobj * sizeof(uint32_t), &ctx);
934 	if (err)
935 		goto done;
936 	err = hwrite(idxfd, packidx.hdr.offsets, nobj * sizeof(uint32_t),
937 	    &ctx);
938 	if (err)
939 		goto done;
940 	if (packidx.nlargeobj > 0) {
941 		err = hwrite(idxfd, packidx.hdr.large_offsets,
942 		    packidx.nlargeobj * sizeof(uint64_t), &ctx);
943 		if (err)
944 			goto done;
945 	}
946 	err = hwrite(idxfd, pack_sha1, SHA1_DIGEST_LENGTH, &ctx);
947 	if (err)
948 		goto done;
949 
950 	SHA1Final(packidx_hash, &ctx);
951 	w = write(idxfd, packidx_hash, sizeof(packidx_hash));
952 	if (w == -1) {
953 		err = got_error_from_errno("write");
954 		goto done;
955 	}
956 	if (w != sizeof(packidx_hash)) {
957 		err = got_error(GOT_ERR_IO);
958 		goto done;
959 	}
960 done:
961 	free(objects);
962 	free(packidx.hdr.magic);
963 	free(packidx.hdr.version);
964 	free(packidx.hdr.fanout_table);
965 	free(packidx.hdr.sorted_ids);
966 	free(packidx.hdr.offsets);
967 	free(packidx.hdr.large_offsets);
968 	return err;
969 }
970 
971 int
972 main(int argc, char **argv)
973 {
974 	const struct got_error *err = NULL, *close_err;
975 	struct imsgbuf ibuf;
976 	struct imsg imsg;
977 	int idxfd = -1, tmpfd = -1, i;
978 	FILE *tmpfiles[3];
979 	struct got_pack pack;
980 	uint8_t pack_hash[SHA1_DIGEST_LENGTH];
981 	off_t packfile_size;
982 #if 0
983 	static int attached;
984 	while (!attached)
985 		sleep(1);
986 #endif
987 
988 	for (i = 0; i < nitems(tmpfiles); i++)
989 		tmpfiles[i] = NULL;
990 
991 	memset(&pack, 0, sizeof(pack));
992 	pack.fd = -1;
993 	pack.delta_cache = got_delta_cache_alloc(500,
994 	    GOT_DELTA_RESULT_SIZE_CACHED_MAX);
995 	if (pack.delta_cache == NULL) {
996 		err = got_error_from_errno("got_delta_cache_alloc");
997 		goto done;
998 	}
999 
1000 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
1001 #ifndef PROFILE
1002 	/* revoke access to most system calls */
1003 	if (pledge("stdio recvfd", NULL) == -1) {
1004 		err = got_error_from_errno("pledge");
1005 		got_privsep_send_error(&ibuf, err);
1006 		return 1;
1007 	}
1008 #endif
1009 	err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
1010 	if (err)
1011 		goto done;
1012 	if (imsg.hdr.type == GOT_IMSG_STOP)
1013 		goto done;
1014 	if (imsg.hdr.type != GOT_IMSG_IDXPACK_REQUEST) {
1015 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1016 		goto done;
1017 	}
1018 	if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(pack_hash)) {
1019 		err = got_error(GOT_ERR_PRIVSEP_LEN);
1020 		goto done;
1021 	}
1022 	memcpy(pack_hash, imsg.data, sizeof(pack_hash));
1023 	pack.fd = imsg.fd;
1024 
1025 	err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
1026 	if (err)
1027 		goto done;
1028 	if (imsg.hdr.type == GOT_IMSG_STOP)
1029 		goto done;
1030 	if (imsg.hdr.type != GOT_IMSG_IDXPACK_OUTFD) {
1031 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1032 		goto done;
1033 	}
1034 	if (imsg.hdr.len - IMSG_HEADER_SIZE != 0) {
1035 		err = got_error(GOT_ERR_PRIVSEP_LEN);
1036 		goto done;
1037 	}
1038 	idxfd = imsg.fd;
1039 
1040 	for (i = 0; i < nitems(tmpfiles); i++) {
1041 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
1042 		if (err)
1043 			goto done;
1044 		if (imsg.hdr.type == GOT_IMSG_STOP)
1045 			goto done;
1046 		if (imsg.hdr.type != GOT_IMSG_TMPFD) {
1047 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1048 			goto done;
1049 		}
1050 		if (imsg.hdr.len - IMSG_HEADER_SIZE != 0) {
1051 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1052 			goto done;
1053 		}
1054 		tmpfd = imsg.fd;
1055 		tmpfiles[i] = fdopen(tmpfd, "w+");
1056 		if (tmpfiles[i] == NULL) {
1057 			err = got_error_from_errno("fdopen");
1058 			goto done;
1059 		}
1060 		tmpfd = -1;
1061 	}
1062 
1063 	if (lseek(pack.fd, 0, SEEK_END) == -1) {
1064 		err = got_error_from_errno("lseek");
1065 		goto done;
1066 	}
1067 	packfile_size = lseek(pack.fd, 0, SEEK_CUR);
1068 	if (packfile_size == -1) {
1069 		err = got_error_from_errno("lseek");
1070 		goto done;
1071 	}
1072 	pack.filesize = packfile_size; /* XXX off_t vs size_t */
1073 
1074 	if (lseek(pack.fd, 0, SEEK_SET) == -1) {
1075 		err = got_error_from_errno("lseek");
1076 		goto done;
1077 	}
1078 
1079 #ifndef GOT_PACK_NO_MMAP
1080 	pack.map = mmap(NULL, pack.filesize, PROT_READ, MAP_PRIVATE,
1081 	    pack.fd, 0);
1082 	if (pack.map == MAP_FAILED)
1083 		pack.map = NULL; /* fall back to read(2) */
1084 #endif
1085 	err = index_pack(&pack, idxfd, tmpfiles[0], tmpfiles[1], tmpfiles[2],
1086 	    pack_hash, &ibuf);
1087 done:
1088 	close_err = got_pack_close(&pack);
1089 	if (close_err && err == NULL)
1090 		err = close_err;
1091 	if (idxfd != -1 && close(idxfd) == -1 && err == NULL)
1092 		err = got_error_from_errno("close");
1093 	if (tmpfd != -1 && close(tmpfd) == -1 && err == NULL)
1094 		err = got_error_from_errno("close");
1095 	for (i = 0; i < nitems(tmpfiles); i++) {
1096 		if (tmpfiles[i] != NULL && fclose(tmpfiles[i]) == EOF &&
1097 		    err == NULL)
1098 			err = got_error_from_errno("close");
1099 	}
1100 
1101 	if (err == NULL)
1102 		err = send_index_pack_done(&ibuf);
1103 	if (err) {
1104 		got_privsep_send_error(&ibuf, err);
1105 		fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
1106 		got_privsep_send_error(&ibuf, err);
1107 		exit(1);
1108 	}
1109 
1110 	exit(0);
1111 }