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Date:: Thu Jul 23 14:22:36 2020 UTC
Message:: remove pointless error checking in got_fileindex_entry_filetype_set()
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1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/queue.h>
18 #include <sys/tree.h>
19 #include <sys/stat.h>
20 
21 #include <errno.h>
22 #include <dirent.h>
23 #include <fcntl.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <sha1.h>
28 #include <endian.h>
29 #include <limits.h>
30 #include <unistd.h>
31 #include <uuid.h>
32 
33 #include "got_error.h"
34 #include "got_object.h"
35 #include "got_path.h"
36 
37 #include "got_lib_fileindex.h"
38 #include "got_lib_worktree.h"
39 
40 /* got_fileindex_entry flags */
41 #define GOT_FILEIDX_F_PATH_LEN		0x00000fff
42 #define GOT_FILEIDX_F_STAGE		0x0000f000
43 #define GOT_FILEIDX_F_STAGE_SHIFT	12
44 #define GOT_FILEIDX_F_NOT_FLUSHED	0x00010000
45 #define GOT_FILEIDX_F_NO_BLOB		0x00020000
46 #define GOT_FILEIDX_F_NO_COMMIT		0x00040000
47 #define GOT_FILEIDX_F_NO_FILE_ON_DISK	0x00080000
48 #define GOT_FILEIDX_F_REMOVE_ON_FLUSH	0x00100000
49 
50 struct got_fileindex {
51 	struct got_fileindex_tree entries;
52 	int nentries; /* Does not include entries marked for removal. */
53 #define GOT_FILEIDX_MAX_ENTRIES INT_MAX
54 };
55 
56 uint16_t
57 got_fileindex_perms_from_st(struct stat *sb)
58 {
59 	uint16_t perms = (sb->st_mode & (S_IRWXU | S_IRWXG | S_IRWXO));
60 	return (perms << GOT_FILEIDX_MODE_PERMS_SHIFT);
61 }
62 
63 mode_t
64 got_fileindex_perms_to_st(struct got_fileindex_entry *ie)
65 {
66 	mode_t perms = (ie->mode >> GOT_FILEIDX_MODE_PERMS_SHIFT);
67 	return (S_IFREG | (perms & (S_IRWXU | S_IRWXG | S_IRWXO)));
68 }
69 
70 const struct got_error *
71 got_fileindex_entry_update(struct got_fileindex_entry *ie,
72     const char *ondisk_path, uint8_t *blob_sha1, uint8_t *commit_sha1,
73     int update_timestamps)
74 {
75 	struct stat sb;
76 
77 	if (lstat(ondisk_path, &sb) != 0) {
78 		if (!((ie->flags & GOT_FILEIDX_F_NO_FILE_ON_DISK) &&
79 		    errno == ENOENT))
80 			return got_error_from_errno2("lstat", ondisk_path);
81 	} else {
82 		if (sb.st_mode & S_IFDIR)
83 			return got_error_set_errno(EISDIR, ondisk_path);
84 		ie->flags &= ~GOT_FILEIDX_F_NO_FILE_ON_DISK;
85 	}
86 
87 
88 	if ((ie->flags & GOT_FILEIDX_F_NO_FILE_ON_DISK) == 0) {
89 		if (update_timestamps) {
90 			ie->ctime_sec = sb.st_ctime;
91 			ie->ctime_nsec = sb.st_ctimensec;
92 			ie->mtime_sec = sb.st_mtime;
93 			ie->mtime_nsec = sb.st_mtimensec;
94 		}
95 		ie->uid = sb.st_uid;
96 		ie->gid = sb.st_gid;
97 		ie->size = (sb.st_size & 0xffffffff);
98 		if (S_ISLNK(sb.st_mode))
99 			ie->mode = GOT_FILEIDX_MODE_SYMLINK;
100 		else {
101 			ie->mode = GOT_FILEIDX_MODE_REGULAR_FILE;
102 			ie->mode |= got_fileindex_perms_from_st(&sb);
103 		}
104 	}
105 
106 	if (blob_sha1) {
107 		memcpy(ie->blob_sha1, blob_sha1, SHA1_DIGEST_LENGTH);
108 		ie->flags &= ~GOT_FILEIDX_F_NO_BLOB;
109 	} else
110 		ie->flags |= GOT_FILEIDX_F_NO_BLOB;
111 
112 	if (commit_sha1) {
113 		memcpy(ie->commit_sha1, commit_sha1, SHA1_DIGEST_LENGTH);
114 		ie->flags &= ~GOT_FILEIDX_F_NO_COMMIT;
115 	} else
116 		ie->flags |= GOT_FILEIDX_F_NO_COMMIT;
117 
118 	return NULL;
119 }
120 
121 void
122 got_fileindex_entry_mark_deleted_from_disk(struct got_fileindex_entry *ie)
123 {
124 	ie->flags |= GOT_FILEIDX_F_NO_FILE_ON_DISK;
125 }
126 
127 const struct got_error *
128 got_fileindex_entry_alloc(struct got_fileindex_entry **ie,
129     const char *relpath)
130 {
131 	size_t len;
132 
133 	*ie = calloc(1, sizeof(**ie));
134 	if (*ie == NULL)
135 		return got_error_from_errno("calloc");
136 
137 	(*ie)->path = strdup(relpath);
138 	if ((*ie)->path == NULL) {
139 		const struct got_error *err = got_error_from_errno("strdup");
140 		free(*ie);
141 		*ie = NULL;
142 		return err;
143 	}
144 
145 	len = strlen(relpath);
146 	if (len > GOT_FILEIDX_F_PATH_LEN)
147 		len = GOT_FILEIDX_F_PATH_LEN;
148 	(*ie)->flags |= len;
149 
150 	return NULL;
151 }
152 
153 void
154 got_fileindex_entry_free(struct got_fileindex_entry *ie)
155 {
156 	free(ie->path);
157 	free(ie);
158 }
159 
160 size_t
161 got_fileindex_entry_path_len(const struct got_fileindex_entry *ie)
162 {
163 	return (size_t)(ie->flags & GOT_FILEIDX_F_PATH_LEN);
164 }
165 
166 uint32_t
167 got_fileindex_entry_stage_get(const struct got_fileindex_entry *ie)
168 {
169 	return ((ie->flags & GOT_FILEIDX_F_STAGE) >> GOT_FILEIDX_F_STAGE_SHIFT);
170 }
171 
172 void
173 got_fileindex_entry_stage_set(struct got_fileindex_entry *ie, uint32_t stage)
174 {
175 	ie->flags &= ~GOT_FILEIDX_F_STAGE;
176 	ie->flags |= ((stage << GOT_FILEIDX_F_STAGE_SHIFT) &
177 	    GOT_FILEIDX_F_STAGE);
178 }
179 
180 int
181 got_fileindex_entry_filetype_get(struct got_fileindex_entry *ie)
182 {
183 	return (ie->mode & GOT_FILEIDX_MODE_FILE_TYPE_ONDISK);
184 }
185 
186 void
187 got_fileindex_entry_filetype_set(struct got_fileindex_entry *ie, int type)
188 {
189 	ie->mode &= ~GOT_FILEIDX_MODE_FILE_TYPE_ONDISK;
190 	ie->mode |= (type & GOT_FILEIDX_MODE_FILE_TYPE_ONDISK);
191 }
192 
193 void
194 got_fileindex_entry_staged_filetype_set(struct got_fileindex_entry *ie, int type)
195 {
196 	ie->mode &= ~GOT_FILEIDX_MODE_FILE_TYPE_STAGED;
197 	ie->mode |= ((type << GOT_FILEIDX_MODE_FILE_TYPE_STAGED_SHIFT) &
198 	    GOT_FILEIDX_MODE_FILE_TYPE_STAGED);
199 }
200 
201 int
202 got_fileindex_entry_staged_filetype_get(struct got_fileindex_entry *ie)
203 {
204 	return (ie->mode & GOT_FILEIDX_MODE_FILE_TYPE_STAGED) >>
205 	    GOT_FILEIDX_MODE_FILE_TYPE_STAGED_SHIFT;
206 }
207 
208 int
209 got_fileindex_entry_has_blob(struct got_fileindex_entry *ie)
210 {
211 	return (ie->flags & GOT_FILEIDX_F_NO_BLOB) == 0;
212 }
213 
214 int
215 got_fileindex_entry_has_commit(struct got_fileindex_entry *ie)
216 {
217 	return (ie->flags & GOT_FILEIDX_F_NO_COMMIT) == 0;
218 }
219 
220 int
221 got_fileindex_entry_has_file_on_disk(struct got_fileindex_entry *ie)
222 {
223 	return (ie->flags & GOT_FILEIDX_F_NO_FILE_ON_DISK) == 0;
224 }
225 
226 static const struct got_error *
227 add_entry(struct got_fileindex *fileindex, struct got_fileindex_entry *ie)
228 {
229 	if (fileindex->nentries >= GOT_FILEIDX_MAX_ENTRIES)
230 		return got_error(GOT_ERR_NO_SPACE);
231 
232 	RB_INSERT(got_fileindex_tree, &fileindex->entries, ie);
233 	fileindex->nentries++;
234 	return NULL;
235 }
236 
237 const struct got_error *
238 got_fileindex_entry_add(struct got_fileindex *fileindex,
239     struct got_fileindex_entry *ie)
240 {
241 	/* Flag this entry until it gets written out to disk. */
242 	ie->flags |= GOT_FILEIDX_F_NOT_FLUSHED;
243 
244 	return add_entry(fileindex, ie);
245 }
246 
247 void
248 got_fileindex_entry_remove(struct got_fileindex *fileindex,
249     struct got_fileindex_entry *ie)
250 {
251 	/*
252 	 * Removing an entry from the RB tree immediately breaks
253 	 * in-progress iterations over file index entries.
254 	 * So flag this entry for removal and remove it once the index
255 	 * is written out to disk. Meanwhile, pretend this entry no longer
256 	 * exists if we get queried for it again before then.
257 	 */
258 	ie->flags |= GOT_FILEIDX_F_REMOVE_ON_FLUSH;
259 	fileindex->nentries--;
260 }
261 
262 struct got_fileindex_entry *
263 got_fileindex_entry_get(struct got_fileindex *fileindex, const char *path,
264     size_t path_len)
265 {
266 	struct got_fileindex_entry *ie;
267 	struct got_fileindex_entry key;
268 	memset(&key, 0, sizeof(key));
269 	key.path = (char *)path;
270 	key.flags = (path_len & GOT_FILEIDX_F_PATH_LEN);
271 	ie = RB_FIND(got_fileindex_tree, &fileindex->entries, &key);
272 	if (ie && (ie->flags & GOT_FILEIDX_F_REMOVE_ON_FLUSH))
273 		return NULL;
274 	return ie;
275 }
276 
277 const struct got_error *
278 got_fileindex_for_each_entry_safe(struct got_fileindex *fileindex,
279     got_fileindex_cb cb, void *cb_arg)
280 {
281 	const struct got_error *err;
282 	struct got_fileindex_entry *ie, *tmp;
283 
284 	RB_FOREACH_SAFE(ie, got_fileindex_tree, &fileindex->entries, tmp) {
285 		if (ie->flags & GOT_FILEIDX_F_REMOVE_ON_FLUSH)
286 			continue;
287 		err = (*cb)(cb_arg, ie);
288 		if (err)
289 			return err;
290 	}
291 	return NULL;
292 }
293 
294 struct got_fileindex *
295 got_fileindex_alloc(void)
296 {
297 	struct got_fileindex *fileindex;
298 
299 	fileindex = calloc(1, sizeof(*fileindex));
300 	if (fileindex == NULL)
301 		return NULL;
302 
303 	RB_INIT(&fileindex->entries);
304 	return fileindex;
305 }
306 
307 void
308 got_fileindex_free(struct got_fileindex *fileindex)
309 {
310 	struct got_fileindex_entry *ie;
311 
312 	while ((ie = RB_MIN(got_fileindex_tree, &fileindex->entries))) {
313 		RB_REMOVE(got_fileindex_tree, &fileindex->entries, ie);
314 		got_fileindex_entry_free(ie);
315 	}
316 	free(fileindex);
317 }
318 
319 static const struct got_error *
320 write_fileindex_val64(SHA1_CTX *ctx, uint64_t val, FILE *outfile)
321 {
322 	size_t n;
323 
324 	val = htobe64(val);
325 	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
326 	n = fwrite(&val, 1, sizeof(val), outfile);
327 	if (n != sizeof(val))
328 		return got_ferror(outfile, GOT_ERR_IO);
329 	return NULL;
330 }
331 
332 static const struct got_error *
333 write_fileindex_val32(SHA1_CTX *ctx, uint32_t val, FILE *outfile)
334 {
335 	size_t n;
336 
337 	val = htobe32(val);
338 	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
339 	n = fwrite(&val, 1, sizeof(val), outfile);
340 	if (n != sizeof(val))
341 		return got_ferror(outfile, GOT_ERR_IO);
342 	return NULL;
343 }
344 
345 static const struct got_error *
346 write_fileindex_val16(SHA1_CTX *ctx, uint16_t val, FILE *outfile)
347 {
348 	size_t n;
349 
350 	val = htobe16(val);
351 	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
352 	n = fwrite(&val, 1, sizeof(val), outfile);
353 	if (n != sizeof(val))
354 		return got_ferror(outfile, GOT_ERR_IO);
355 	return NULL;
356 }
357 
358 static const struct got_error *
359 write_fileindex_path(SHA1_CTX *ctx, const char *path, FILE *outfile)
360 {
361 	size_t n, len, pad = 0;
362 	static const uint8_t zero[8] = { 0 };
363 
364 	len = strlen(path);
365 	while ((len + pad) % 8 != 0)
366 		pad++;
367 	if (pad == 0)
368 		pad = 8; /* NUL-terminate */
369 
370 	SHA1Update(ctx, path, len);
371 	n = fwrite(path, 1, len, outfile);
372 	if (n != len)
373 		return got_ferror(outfile, GOT_ERR_IO);
374 	SHA1Update(ctx, zero, pad);
375 	n = fwrite(zero, 1, pad, outfile);
376 	if (n != pad)
377 		return got_ferror(outfile, GOT_ERR_IO);
378 	return NULL;
379 }
380 
381 static const struct got_error *
382 write_fileindex_entry(SHA1_CTX *ctx, struct got_fileindex_entry *ie,
383     FILE *outfile)
384 {
385 	const struct got_error *err;
386 	size_t n;
387 	uint32_t stage;
388 
389 	err = write_fileindex_val64(ctx, ie->ctime_sec, outfile);
390 	if (err)
391 		return err;
392 	err = write_fileindex_val64(ctx, ie->ctime_nsec, outfile);
393 	if (err)
394 		return err;
395 	err = write_fileindex_val64(ctx, ie->mtime_sec, outfile);
396 	if (err)
397 		return err;
398 	err = write_fileindex_val64(ctx, ie->mtime_nsec, outfile);
399 	if (err)
400 		return err;
401 
402 	err = write_fileindex_val32(ctx, ie->uid, outfile);
403 	if (err)
404 		return err;
405 	err = write_fileindex_val32(ctx, ie->gid, outfile);
406 	if (err)
407 		return err;
408 	err = write_fileindex_val32(ctx, ie->size, outfile);
409 	if (err)
410 		return err;
411 
412 	err = write_fileindex_val16(ctx, ie->mode, outfile);
413 	if (err)
414 		return err;
415 
416 	SHA1Update(ctx, ie->blob_sha1, SHA1_DIGEST_LENGTH);
417 	n = fwrite(ie->blob_sha1, 1, SHA1_DIGEST_LENGTH, outfile);
418 	if (n != SHA1_DIGEST_LENGTH)
419 		return got_ferror(outfile, GOT_ERR_IO);
420 
421 	SHA1Update(ctx, ie->commit_sha1, SHA1_DIGEST_LENGTH);
422 	n = fwrite(ie->commit_sha1, 1, SHA1_DIGEST_LENGTH, outfile);
423 	if (n != SHA1_DIGEST_LENGTH)
424 		return got_ferror(outfile, GOT_ERR_IO);
425 
426 	err = write_fileindex_val32(ctx, ie->flags, outfile);
427 	if (err)
428 		return err;
429 
430 	err = write_fileindex_path(ctx, ie->path, outfile);
431 	if (err)
432 		return err;
433 
434 	stage = got_fileindex_entry_stage_get(ie);
435 	if (stage == GOT_FILEIDX_STAGE_MODIFY ||
436 	    stage == GOT_FILEIDX_STAGE_ADD) {
437 		SHA1Update(ctx, ie->staged_blob_sha1, SHA1_DIGEST_LENGTH);
438 		n = fwrite(ie->staged_blob_sha1, 1, SHA1_DIGEST_LENGTH,
439 		    outfile);
440 		if (n != SHA1_DIGEST_LENGTH)
441 			return got_ferror(outfile, GOT_ERR_IO);
442 	}
443 
444 	return NULL;
445 }
446 
447 const struct got_error *
448 got_fileindex_write(struct got_fileindex *fileindex, FILE *outfile)
449 {
450 	const struct got_error *err = NULL;
451 	struct got_fileindex_hdr hdr;
452 	SHA1_CTX ctx;
453 	uint8_t sha1[SHA1_DIGEST_LENGTH];
454 	size_t n;
455 	struct got_fileindex_entry *ie, *tmp;
456 
457 	SHA1Init(&ctx);
458 
459 	hdr.signature = htobe32(GOT_FILE_INDEX_SIGNATURE);
460 	hdr.version = htobe32(GOT_FILE_INDEX_VERSION);
461 	hdr.nentries = htobe32(fileindex->nentries);
462 
463 	SHA1Update(&ctx, (uint8_t *)&hdr.signature, sizeof(hdr.signature));
464 	SHA1Update(&ctx, (uint8_t *)&hdr.version, sizeof(hdr.version));
465 	SHA1Update(&ctx, (uint8_t *)&hdr.nentries, sizeof(hdr.nentries));
466 	n = fwrite(&hdr.signature, 1, sizeof(hdr.signature), outfile);
467 	if (n != sizeof(hdr.signature))
468 		return got_ferror(outfile, GOT_ERR_IO);
469 	n = fwrite(&hdr.version, 1, sizeof(hdr.version), outfile);
470 	if (n != sizeof(hdr.version))
471 		return got_ferror(outfile, GOT_ERR_IO);
472 	n = fwrite(&hdr.nentries, 1, sizeof(hdr.nentries), outfile);
473 	if (n != sizeof(hdr.nentries))
474 		return got_ferror(outfile, GOT_ERR_IO);
475 
476 	RB_FOREACH_SAFE(ie, got_fileindex_tree, &fileindex->entries, tmp) {
477 		ie->flags &= ~GOT_FILEIDX_F_NOT_FLUSHED;
478 		if (ie->flags & GOT_FILEIDX_F_REMOVE_ON_FLUSH) {
479 			RB_REMOVE(got_fileindex_tree, &fileindex->entries, ie);
480 			got_fileindex_entry_free(ie);
481 			continue;
482 		}
483 		err = write_fileindex_entry(&ctx, ie, outfile);
484 		if (err)
485 			return err;
486 	}
487 
488 	SHA1Final(sha1, &ctx);
489 	n = fwrite(sha1, 1, sizeof(sha1), outfile);
490 	if (n != sizeof(sha1))
491 		return got_ferror(outfile, GOT_ERR_IO);
492 
493 	if (fflush(outfile) != 0)
494 		return got_error_from_errno("fflush");
495 
496 	return NULL;
497 }
498 
499 static const struct got_error *
500 read_fileindex_val64(uint64_t *val, SHA1_CTX *ctx, FILE *infile)
501 {
502 	size_t n;
503 
504 	n = fread(val, 1, sizeof(*val), infile);
505 	if (n != sizeof(*val))
506 		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
507 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
508 	*val = be64toh(*val);
509 	return NULL;
510 }
511 
512 static const struct got_error *
513 read_fileindex_val32(uint32_t *val, SHA1_CTX *ctx, FILE *infile)
514 {
515 	size_t n;
516 
517 	n = fread(val, 1, sizeof(*val), infile);
518 	if (n != sizeof(*val))
519 		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
520 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
521 	*val = be32toh(*val);
522 	return NULL;
523 }
524 
525 static const struct got_error *
526 read_fileindex_val16(uint16_t *val, SHA1_CTX *ctx, FILE *infile)
527 {
528 	size_t n;
529 
530 	n = fread(val, 1, sizeof(*val), infile);
531 	if (n != sizeof(*val))
532 		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
533 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
534 	*val = be16toh(*val);
535 	return NULL;
536 }
537 
538 static const struct got_error *
539 read_fileindex_path(char **path, SHA1_CTX *ctx, FILE *infile)
540 {
541 	const struct got_error *err = NULL;
542 	const size_t chunk_size = 8;
543 	size_t n, len = 0, totlen = chunk_size;
544 
545 	*path = malloc(totlen);
546 	if (*path == NULL)
547 		return got_error_from_errno("malloc");
548 
549 	do {
550 		if (len + chunk_size > totlen) {
551 			char *p = reallocarray(*path, totlen + chunk_size, 1);
552 			if (p == NULL) {
553 				err = got_error_from_errno("reallocarray");
554 				break;
555 			}
556 			totlen += chunk_size;
557 			*path = p;
558 		}
559 		n = fread(*path + len, 1, chunk_size, infile);
560 		if (n != chunk_size) {
561 			err = got_ferror(infile, GOT_ERR_FILEIDX_BAD);
562 			break;
563 		}
564 		SHA1Update(ctx, *path + len, chunk_size);
565 		len += chunk_size;
566 	} while (memchr(*path + len - chunk_size, '\0', chunk_size) == NULL);
567 
568 	if (err) {
569 		free(*path);
570 		*path = NULL;
571 	}
572 	return err;
573 }
574 
575 static const struct got_error *
576 read_fileindex_entry(struct got_fileindex_entry **iep, SHA1_CTX *ctx,
577     FILE *infile, uint32_t version)
578 {
579 	const struct got_error *err;
580 	struct got_fileindex_entry *ie;
581 	size_t n;
582 
583 	*iep = NULL;
584 
585 	ie = calloc(1, sizeof(*ie));
586 	if (ie == NULL)
587 		return got_error_from_errno("calloc");
588 
589 	err = read_fileindex_val64(&ie->ctime_sec, ctx, infile);
590 	if (err)
591 		goto done;
592 	err = read_fileindex_val64(&ie->ctime_nsec, ctx, infile);
593 	if (err)
594 		goto done;
595 	err = read_fileindex_val64(&ie->mtime_sec, ctx, infile);
596 	if (err)
597 		goto done;
598 	err = read_fileindex_val64(&ie->mtime_nsec, ctx, infile);
599 	if (err)
600 		goto done;
601 
602 	err = read_fileindex_val32(&ie->uid, ctx, infile);
603 	if (err)
604 		goto done;
605 	err = read_fileindex_val32(&ie->gid, ctx, infile);
606 	if (err)
607 		goto done;
608 	err = read_fileindex_val32(&ie->size, ctx, infile);
609 	if (err)
610 		goto done;
611 
612 	err = read_fileindex_val16(&ie->mode, ctx, infile);
613 	if (err)
614 		goto done;
615 
616 	n = fread(ie->blob_sha1, 1, SHA1_DIGEST_LENGTH, infile);
617 	if (n != SHA1_DIGEST_LENGTH) {
618 		err = got_ferror(infile, GOT_ERR_FILEIDX_BAD);
619 		goto done;
620 	}
621 	SHA1Update(ctx, ie->blob_sha1, SHA1_DIGEST_LENGTH);
622 
623 	n = fread(ie->commit_sha1, 1, SHA1_DIGEST_LENGTH, infile);
624 	if (n != SHA1_DIGEST_LENGTH) {
625 		err = got_ferror(infile, GOT_ERR_FILEIDX_BAD);
626 		goto done;
627 	}
628 	SHA1Update(ctx, ie->commit_sha1, SHA1_DIGEST_LENGTH);
629 
630 	err = read_fileindex_val32(&ie->flags, ctx, infile);
631 	if (err)
632 		goto done;
633 
634 	err = read_fileindex_path(&ie->path, ctx, infile);
635 	if (err)
636 		goto done;
637 
638 	if (version >= 2) {
639 		uint32_t stage = got_fileindex_entry_stage_get(ie);
640 		if (stage == GOT_FILEIDX_STAGE_MODIFY ||
641 		    stage == GOT_FILEIDX_STAGE_ADD) {
642 			n = fread(ie->staged_blob_sha1, 1, SHA1_DIGEST_LENGTH,
643 			    infile);
644 			if (n != SHA1_DIGEST_LENGTH) {
645 				err = got_ferror(infile, GOT_ERR_FILEIDX_BAD);
646 				goto done;
647 			}
648 			SHA1Update(ctx, ie->staged_blob_sha1, SHA1_DIGEST_LENGTH);
649 		}
650 	} else {
651 		/* GOT_FILE_INDEX_VERSION 1 does not support staging. */
652 		ie->flags &= ~GOT_FILEIDX_F_STAGE;
653 	}
654 
655 done:
656 	if (err)
657 		got_fileindex_entry_free(ie);
658 	else
659 		*iep = ie;
660 	return err;
661 }
662 
663 const struct got_error *
664 got_fileindex_read(struct got_fileindex *fileindex, FILE *infile)
665 {
666 	const struct got_error *err = NULL;
667 	struct got_fileindex_hdr hdr;
668 	SHA1_CTX ctx;
669 	struct got_fileindex_entry *ie;
670 	uint8_t sha1_expected[SHA1_DIGEST_LENGTH];
671 	uint8_t sha1[SHA1_DIGEST_LENGTH];
672 	size_t n;
673 	int i;
674 
675 	SHA1Init(&ctx);
676 
677 	n = fread(&hdr.signature, 1, sizeof(hdr.signature), infile);
678 	if (n != sizeof(hdr.signature)) {
679 		if (n == 0) /* EOF */
680 			return NULL;
681 		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
682 	}
683 	n = fread(&hdr.version, 1, sizeof(hdr.version), infile);
684 	if (n != sizeof(hdr.version)) {
685 		if (n == 0) /* EOF */
686 			return NULL;
687 		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
688 	}
689 	n = fread(&hdr.nentries, 1, sizeof(hdr.nentries), infile);
690 	if (n != sizeof(hdr.nentries)) {
691 		if (n == 0) /* EOF */
692 			return NULL;
693 		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
694 	}
695 
696 	SHA1Update(&ctx, (uint8_t *)&hdr.signature, sizeof(hdr.signature));
697 	SHA1Update(&ctx, (uint8_t *)&hdr.version, sizeof(hdr.version));
698 	SHA1Update(&ctx, (uint8_t *)&hdr.nentries, sizeof(hdr.nentries));
699 
700 	hdr.signature = be32toh(hdr.signature);
701 	hdr.version = be32toh(hdr.version);
702 	hdr.nentries = be32toh(hdr.nentries);
703 
704 	if (hdr.signature != GOT_FILE_INDEX_SIGNATURE)
705 		return got_error(GOT_ERR_FILEIDX_SIG);
706 	if (hdr.version > GOT_FILE_INDEX_VERSION)
707 		return got_error(GOT_ERR_FILEIDX_VER);
708 
709 	for (i = 0; i < hdr.nentries; i++) {
710 		err = read_fileindex_entry(&ie, &ctx, infile, hdr.version);
711 		if (err)
712 			return err;
713 		err = add_entry(fileindex, ie);
714 		if (err)
715 			return err;
716 	}
717 
718 	n = fread(sha1_expected, 1, sizeof(sha1_expected), infile);
719 	if (n != sizeof(sha1_expected))
720 		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
721 	SHA1Final(sha1, &ctx);
722 	if (memcmp(sha1, sha1_expected, SHA1_DIGEST_LENGTH) != 0)
723 		return got_error(GOT_ERR_FILEIDX_CSUM);
724 
725 	return NULL;
726 }
727 
728 static struct got_fileindex_entry *
729 walk_fileindex(struct got_fileindex *fileindex, struct got_fileindex_entry *ie)
730 {
731 	struct got_fileindex_entry *next;
732 
733 	next = RB_NEXT(got_fileindex_tree, &fileindex->entries, ie);
734 
735 	/* Skip entries which were added or removed by diff callbacks. */
736 	while (next && (next->flags & (GOT_FILEIDX_F_NOT_FLUSHED |
737 	    GOT_FILEIDX_F_REMOVE_ON_FLUSH)))
738 		next = RB_NEXT(got_fileindex_tree, &fileindex->entries, next);
739 
740 	return next;
741 }
742 
743 static const struct got_error *
744 diff_fileindex_tree(struct got_fileindex *, struct got_fileindex_entry **ie,
745     struct got_tree_object *tree, const char *, const char *,
746     struct got_repository *, struct got_fileindex_diff_tree_cb *, void *);
747 
748 static const struct got_error *
749 walk_tree(struct got_tree_entry **next, struct got_fileindex *fileindex,
750     struct got_fileindex_entry **ie, struct got_tree_object *tree, int *tidx,
751     const char *path, const char *entry_name, struct got_repository *repo,
752     struct got_fileindex_diff_tree_cb *cb, void *cb_arg)
753 {
754 	const struct got_error *err = NULL;
755 	struct got_tree_entry *te = got_object_tree_get_entry(tree, *tidx);
756 
757 	if (!got_object_tree_entry_is_submodule(te) &&
758 	    S_ISDIR(got_tree_entry_get_mode(te))) {
759 		char *subpath;
760 		struct got_tree_object *subtree;
761 
762 		if (asprintf(&subpath, "%s%s%s", path,
763 		    path[0] == '\0' ? "" : "/",
764 		    got_tree_entry_get_name(te)) == -1)
765 			return got_error_from_errno("asprintf");
766 
767 		err = got_object_open_as_tree(&subtree, repo,
768 		    got_tree_entry_get_id(te));
769 		if (err) {
770 			free(subpath);
771 			return err;
772 		}
773 
774 		err = diff_fileindex_tree(fileindex, ie, subtree, subpath,
775 		    entry_name, repo, cb, cb_arg);
776 		free(subpath);
777 		got_object_tree_close(subtree);
778 		if (err)
779 			return err;
780 	}
781 
782 	(*tidx)++;
783 	*next = got_object_tree_get_entry(tree, *tidx);
784 	return NULL;
785 }
786 
787 static const struct got_error *
788 diff_fileindex_tree(struct got_fileindex *fileindex,
789     struct got_fileindex_entry **ie, struct got_tree_object *tree,
790     const char *path, const char *entry_name, struct got_repository *repo,
791     struct got_fileindex_diff_tree_cb *cb, void *cb_arg)
792 {
793 	const struct got_error *err = NULL;
794 	struct got_tree_entry *te = NULL;
795 	size_t path_len = strlen(path);
796 	struct got_fileindex_entry *next;
797 	int tidx = 0;
798 
799 	te = got_object_tree_get_entry(tree, tidx);
800 	while ((*ie && got_path_is_child((*ie)->path, path, path_len)) || te) {
801 		if (te && *ie) {
802 			char *te_path;
803 			const char *te_name = got_tree_entry_get_name(te);
804 			int cmp;
805 			if (asprintf(&te_path, "%s/%s", path, te_name) == -1) {
806 				err = got_error_from_errno("asprintf");
807 				break;
808 			}
809 			cmp = got_path_cmp((*ie)->path, te_path,
810 			    got_fileindex_entry_path_len(*ie), strlen(te_path));
811 			free(te_path);
812 			if (cmp == 0) {
813 				if (got_path_is_child((*ie)->path, path,
814 				    path_len) &&
815 				    !got_object_tree_entry_is_submodule(te) &&
816 				    (entry_name == NULL ||
817 				    strcmp(te_name, entry_name) == 0)) {
818 					err = cb->diff_old_new(cb_arg, *ie, te,
819 					    path);
820 					if (err || entry_name)
821 						break;
822 				}
823 				*ie = walk_fileindex(fileindex, *ie);
824 				err = walk_tree(&te, fileindex, ie, tree, &tidx,
825 				    path, entry_name, repo, cb, cb_arg);
826 			} else if (cmp < 0) {
827 				next = walk_fileindex(fileindex, *ie);
828 				if (got_path_is_child((*ie)->path, path,
829 				    path_len) && (entry_name == NULL ||
830 				    strcmp(te_name, entry_name) == 0)) {
831 					err = cb->diff_old(cb_arg, *ie, path);
832 					if (err || entry_name)
833 						break;
834 				}
835 				*ie = next;
836 			} else {
837 				if ((entry_name == NULL ||
838 				    strcmp(te_name, entry_name) == 0)) {
839 					err = cb->diff_new(cb_arg, te, path);
840 					if (err || entry_name)
841 						break;
842 				}
843 				err = walk_tree(&te, fileindex, ie, tree, &tidx,
844 				    path, entry_name, repo, cb, cb_arg);
845 			}
846 			if (err)
847 				break;
848 		} else if (*ie) {
849 			next = walk_fileindex(fileindex, *ie);
850 			if (got_path_is_child((*ie)->path, path, path_len) &&
851 			    (entry_name == NULL ||
852 			    (te && strcmp(got_tree_entry_get_name(te),
853 			    entry_name) == 0))) {
854 				err = cb->diff_old(cb_arg, *ie, path);
855 				if (err || entry_name)
856 					break;
857 			}
858 			*ie = next;
859 		} else if (te) {
860 			if (!got_object_tree_entry_is_submodule(te) &&
861 			    (entry_name == NULL ||
862 			    strcmp(got_tree_entry_get_name(te), entry_name)
863 			    == 0)) {
864 				err = cb->diff_new(cb_arg, te, path);
865 				if (err || entry_name)
866 					break;
867 			}
868 			err = walk_tree(&te, fileindex, ie, tree, &tidx, path,
869 			    entry_name, repo, cb, cb_arg);
870 			if (err)
871 				break;
872 		}
873 	}
874 
875 	return err;
876 }
877 
878 const struct got_error *
879 got_fileindex_diff_tree(struct got_fileindex *fileindex,
880     struct got_tree_object *tree, const char *path, const char *entry_name,
881     struct got_repository *repo,
882     struct got_fileindex_diff_tree_cb *cb, void *cb_arg)
883 {
884 	struct got_fileindex_entry *ie;
885 	ie = RB_MIN(got_fileindex_tree, &fileindex->entries);
886 	while (ie && !got_path_is_child(ie->path, path, strlen(path)))
887 		ie = walk_fileindex(fileindex, ie);
888 	return diff_fileindex_tree(fileindex, &ie, tree, path, entry_name, repo,
889 	    cb, cb_arg);
890 }
891 
892 static const struct got_error *
893 diff_fileindex_dir(struct got_fileindex *, struct got_fileindex_entry **,
894     struct got_pathlist_head *, int, const char *, const char *,
895     struct got_repository *, struct got_fileindex_diff_dir_cb *, void *);
896 
897 static const struct got_error *
898 read_dirlist(struct got_pathlist_head *dirlist, DIR *dir, const char *path)
899 {
900 	const struct got_error *err = NULL;
901 	struct got_pathlist_entry *new = NULL;
902 	struct dirent *dep = NULL;
903 	struct dirent *de = NULL;
904 
905 	for (;;) {
906 		de = malloc(sizeof(struct dirent) + NAME_MAX + 1);
907 		if (de == NULL) {
908 			err = got_error_from_errno("malloc");
909 			break;
910 		}
911 
912 		if (readdir_r(dir, de, &dep) != 0) {
913 			err = got_error_from_errno("readdir_r");
914 			free(de);
915 			break;
916 		}
917 		if (dep == NULL) {
918 			free(de);
919 			break;
920 		}
921 
922 		if (strcmp(de->d_name, ".") == 0 ||
923 		    strcmp(de->d_name, "..") == 0 ||
924 		    (path[0] == '\0' &&
925 		    strcmp(de->d_name, GOT_WORKTREE_GOT_DIR) == 0)) {
926 			free(de);
927 			continue;
928 		}
929 
930 		err = got_pathlist_insert(&new, dirlist, de->d_name, de);
931 		if (err) {
932 			free(de);
933 			break;
934 		}
935 		if (new == NULL) {
936 			err = got_error(GOT_ERR_DIR_DUP_ENTRY);
937 			free(de);
938 			break;
939 		}
940 	}
941 
942 	return err;
943 }
944 
945 void
946 free_dirlist(struct got_pathlist_head *dirlist)
947 {
948 	struct got_pathlist_entry *dle;
949 
950 	TAILQ_FOREACH(dle, dirlist, entry)
951 		free(dle->data);
952 	got_pathlist_free(dirlist);
953 }
954 
955 static const struct got_error *
956 walk_dir(struct got_pathlist_entry **next, struct got_fileindex *fileindex,
957     struct got_fileindex_entry **ie, struct got_pathlist_entry *dle, int fd,
958     const char *path, const char *rootpath, struct got_repository *repo,
959     struct got_fileindex_diff_dir_cb *cb, void *cb_arg)
960 {
961 	const struct got_error *err = NULL;
962 	struct dirent *de = dle->data;
963 	DIR *subdir = NULL;
964 	int subdirfd = -1;
965 	int type;
966 
967 	*next = NULL;
968 
969 	if (de->d_type == DT_UNKNOWN) {
970 		/* Occurs on NFS mounts without "readdir plus" RPC. */
971 		char *dir_path;
972 		if (asprintf(&dir_path, "%s/%s", rootpath, path) == -1)
973 			return got_error_from_errno("asprintf");
974 		err = got_path_dirent_type(&type, dir_path, de);
975 		free(dir_path);
976 		if (err)
977 			return err;
978 	} else
979 		type = de->d_type;
980 
981 	if (type == DT_DIR) {
982 		char *subpath;
983 		char *subdirpath;
984 		struct got_pathlist_head subdirlist;
985 
986 		TAILQ_INIT(&subdirlist);
987 
988 		if (asprintf(&subpath, "%s%s%s", path,
989 		    path[0] == '\0' ? "" : "/", de->d_name) == -1)
990 			return got_error_from_errno("asprintf");
991 
992 		if (asprintf(&subdirpath, "%s/%s", rootpath, subpath) == -1) {
993 			free(subpath);
994 			return got_error_from_errno("asprintf");
995 		}
996 
997 		subdirfd = openat(fd, de->d_name,
998 		    O_RDONLY | O_NOFOLLOW | O_DIRECTORY);
999 		if (subdirfd == -1) {
1000 			if (errno == EACCES) {
1001 				*next = TAILQ_NEXT(dle, entry);
1002 				return NULL;
1003 			}
1004 			err = got_error_from_errno2("openat", subdirpath);
1005 			free(subpath);
1006 			free(subdirpath);
1007 			return err;
1008 		}
1009 
1010 		subdir = fdopendir(subdirfd);
1011 		if (subdir == NULL)
1012 			return got_error_from_errno2("fdopendir", path);
1013 		subdirfd = -1;
1014 		err = read_dirlist(&subdirlist, subdir, subdirpath);
1015 		if (err) {
1016 			free(subpath);
1017 			free(subdirpath);
1018 			closedir(subdir);
1019 			return err;
1020 		}
1021 		err = diff_fileindex_dir(fileindex, ie, &subdirlist,
1022 		    dirfd(subdir), rootpath, subpath, repo, cb, cb_arg);
1023 		if (subdir && closedir(subdir) == -1 && err == NULL)
1024 			err = got_error_from_errno2("closedir", subdirpath);
1025 		free(subpath);
1026 		free(subdirpath);
1027 		free_dirlist(&subdirlist);
1028 		if (err)
1029 			return err;
1030 	}
1031 
1032 	*next = TAILQ_NEXT(dle, entry);
1033 	return NULL;
1034 }
1035 
1036 static const struct got_error *
1037 diff_fileindex_dir(struct got_fileindex *fileindex,
1038     struct got_fileindex_entry **ie, struct got_pathlist_head *dirlist,
1039     int dirfd, const char *rootpath, const char *path,
1040     struct got_repository *repo,
1041     struct got_fileindex_diff_dir_cb *cb, void *cb_arg)
1042 {
1043 	const struct got_error *err = NULL;
1044 	struct dirent *de = NULL;
1045 	size_t path_len = strlen(path);
1046 	struct got_pathlist_entry *dle;
1047 
1048 	if (cb->diff_traverse) {
1049 		err = cb->diff_traverse(cb_arg, path, dirfd);
1050 		if (err)
1051 			return err;
1052 	}
1053 
1054 	dle = TAILQ_FIRST(dirlist);
1055 	while ((*ie && got_path_is_child((*ie)->path, path, path_len)) || dle) {
1056 		if (dle && *ie) {
1057 			char *de_path;
1058 			int cmp;
1059 			de = dle->data;
1060 			if (asprintf(&de_path, "%s/%s", path,
1061 			    de->d_name) == -1) {
1062 				err = got_error_from_errno("asprintf");
1063 				break;
1064 			}
1065 			cmp = got_path_cmp((*ie)->path, de_path,
1066 			    got_fileindex_entry_path_len(*ie),
1067 			    strlen(path) + 1 + de->d_namlen);
1068 			free(de_path);
1069 			if (cmp == 0) {
1070 				err = cb->diff_old_new(cb_arg, *ie, de, path,
1071 				    dirfd);
1072 				if (err)
1073 					break;
1074 				*ie = walk_fileindex(fileindex, *ie);
1075 				err = walk_dir(&dle, fileindex, ie, dle, dirfd,
1076 				    path, rootpath, repo, cb, cb_arg);
1077 			} else if (cmp < 0 ) {
1078 				err = cb->diff_old(cb_arg, *ie, path);
1079 				if (err)
1080 					break;
1081 				*ie = walk_fileindex(fileindex, *ie);
1082 			} else {
1083 				err = cb->diff_new(cb_arg, de, path, dirfd);
1084 				if (err)
1085 					break;
1086 				err = walk_dir(&dle, fileindex, ie, dle, dirfd,
1087 				    path, rootpath, repo, cb, cb_arg);
1088 			}
1089 			if (err)
1090 				break;
1091 		} else if (*ie) {
1092 			err = cb->diff_old(cb_arg, *ie, path);
1093 			if (err)
1094 				break;
1095 			*ie = walk_fileindex(fileindex, *ie);
1096 		} else if (dle) {
1097 			de = dle->data;
1098 			err = cb->diff_new(cb_arg, de, path, dirfd);
1099 			if (err)
1100 				break;
1101 			err = walk_dir(&dle, fileindex, ie, dle, dirfd, path,
1102 			    rootpath, repo, cb, cb_arg);
1103 			if (err)
1104 				break;
1105 		}
1106 	}
1107 
1108 	return err;
1109 }
1110 
1111 const struct got_error *
1112 got_fileindex_diff_dir(struct got_fileindex *fileindex, int fd,
1113     const char *rootpath, const char *path, struct got_repository *repo,
1114     struct got_fileindex_diff_dir_cb *cb, void *cb_arg)
1115 {
1116 	const struct got_error *err;
1117 	struct got_fileindex_entry *ie;
1118 	struct got_pathlist_head dirlist;
1119 	int fd2;
1120 	DIR *dir;
1121 
1122 	TAILQ_INIT(&dirlist);
1123 
1124 	/* 
1125 	 * Duplicate the file descriptor so we can call closedir() below
1126 	 * without closing the file descriptor passed in by our caller.
1127 	 */
1128 	fd2 = dup(fd);
1129 	if (fd2 == -1)
1130 		return got_error_from_errno2("dup", path);
1131 	if (lseek(fd2, 0, SEEK_SET) == -1) {
1132 		err = got_error_from_errno2("lseek", path);
1133 		close(fd2);
1134 		return err;
1135 	}
1136 	dir = fdopendir(fd2);
1137 	if (dir == NULL) {
1138 		err = got_error_from_errno2("fdopendir", path);
1139 		close(fd2);
1140 		return err;
1141 	}
1142 	err = read_dirlist(&dirlist, dir, path);
1143 	if (err) {
1144 		closedir(dir);
1145 		return err;
1146 	}
1147 
1148 	ie = RB_MIN(got_fileindex_tree, &fileindex->entries);
1149 	while (ie && !got_path_is_child(ie->path, path, strlen(path)))
1150 		ie = walk_fileindex(fileindex, ie);
1151 	err = diff_fileindex_dir(fileindex, &ie, &dirlist, dirfd(dir),
1152 	    rootpath, path, repo, cb, cb_arg);
1153 
1154 	if (closedir(dir) == -1 && err == NULL)
1155 		err = got_error_from_errno2("closedir", path);
1156 	free_dirlist(&dirlist);
1157 	return err;
1158 }
1159 
1160 RB_GENERATE(got_fileindex_tree, got_fileindex_entry, entry, got_fileindex_cmp);