1 /*
2  * Copyright (c) 2018 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 <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <sha1.h>
25 #include <endian.h>
26 #include <limits.h>
27 
28 #include "got_error.h"
29 
30 #include "got_lib_path.h"
31 #include "got_lib_fileindex.h"
32 
33 struct got_fileindex {
34 	struct got_fileindex_tree entries;
35 	int nentries;
36 #define GOT_FILEIDX_MAX_ENTRIES INT_MAX
37 };
38 
39 const struct got_error *
40 got_fileindex_entry_update(struct got_fileindex_entry *entry,
41     const char *ondisk_path, uint8_t *blob_sha1, uint8_t *commit_sha1)
42 {
43 	struct stat sb;
44 
45 	if (lstat(ondisk_path, &sb) != 0)
46 		return got_error_from_errno();
47 
48 	entry->ctime_sec = sb.st_ctime;
49 	entry->ctime_nsec = sb.st_ctimensec;
50 	entry->mtime_sec = sb.st_mtime;
51 	entry->mtime_nsec = sb.st_mtimensec;
52 	entry->uid = sb.st_uid;
53 	entry->gid = sb.st_gid;
54 	entry->size = (sb.st_size & 0xffffffff);
55 	if (sb.st_mode & S_IFLNK)
56 		entry->mode = GOT_INDEX_ENTRY_MODE_SYMLINK;
57 	else
58 		entry->mode = GOT_INDEX_ENTRY_MODE_REGULAR_FILE;
59 	entry->mode |= ((sb.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO)) <<
60 	    GOT_INDEX_ENTRY_MODE_PERMS_SHIFT);
61 	memcpy(entry->blob_sha1, blob_sha1, SHA1_DIGEST_LENGTH);
62 	memcpy(entry->commit_sha1, commit_sha1, SHA1_DIGEST_LENGTH);
63 
64 	return NULL;
65 }
66 
67 const struct got_error *
68 got_fileindex_entry_alloc(struct got_fileindex_entry **entry,
69     const char *ondisk_path, const char *relpath, uint8_t *blob_sha1,
70     uint8_t *commit_sha1)
71 {
72 	size_t len;
73 
74 	*entry = calloc(1, sizeof(**entry));
75 	if (*entry == NULL)
76 		return got_error_from_errno();
77 
78 	(*entry)->path = strdup(relpath);
79 	if ((*entry)->path == NULL) {
80 		const struct got_error *err = got_error_from_errno();
81 		free(*entry);
82 		*entry = NULL;
83 		return err;
84 	}
85 
86 	len = strlen(relpath);
87 	if (len > GOT_INDEX_ENTRY_F_PATH_LEN)
88 		len = GOT_INDEX_ENTRY_F_PATH_LEN;
89 	(*entry)->flags |= len;
90 
91 	return got_fileindex_entry_update(*entry, ondisk_path, blob_sha1,
92 	    commit_sha1);
93 }
94 
95 void
96 got_fileindex_entry_free(struct got_fileindex_entry *entry)
97 {
98 	free(entry->path);
99 	free(entry);
100 }
101 
102 const struct got_error *
103 got_fileindex_entry_add(struct got_fileindex *fileindex,
104     struct got_fileindex_entry *entry)
105 {
106 	if (fileindex->nentries >= GOT_FILEIDX_MAX_ENTRIES)
107 		return got_error(GOT_ERR_NO_SPACE);
108 
109 	RB_INSERT(got_fileindex_tree, &fileindex->entries, entry);
110 	fileindex->nentries++;
111 	return NULL;
112 }
113 
114 void
115 got_fileindex_entry_remove(struct got_fileindex *fileindex,
116     struct got_fileindex_entry *entry)
117 {
118 	RB_REMOVE(got_fileindex_tree, &fileindex->entries, entry);
119 	fileindex->nentries--;
120 }
121 
122 struct got_fileindex_entry *
123 got_fileindex_entry_get(struct got_fileindex *fileindex, const char *path)
124 {
125 	struct got_fileindex_entry key;
126 	memset(&key, 0, sizeof(key));
127 	key.path = (char *)path;
128 	return RB_FIND(got_fileindex_tree, &fileindex->entries, &key);
129 }
130 
131 const struct got_error *
132 got_fileindex_for_each_entry_safe(struct got_fileindex *fileindex,
133     got_fileindex_cb cb, void *cb_arg)
134 {
135 	const struct got_error *err;
136 	struct got_fileindex_entry *entry, *tmp;
137 
138 	RB_FOREACH_SAFE(entry, got_fileindex_tree, &fileindex->entries, tmp) {
139 		err = (*cb)(cb_arg, entry);
140 		if (err)
141 			return err;
142 	}
143 	return NULL;
144 }
145 
146 struct got_fileindex *
147 got_fileindex_alloc(void)
148 {
149 	struct got_fileindex *fileindex;
150 
151 	fileindex = calloc(1, sizeof(*fileindex));
152 	if (fileindex == NULL)
153 		return NULL;
154 
155 	RB_INIT(&fileindex->entries);
156 	return fileindex;
157 }
158 
159 void
160 got_fileindex_free(struct got_fileindex *fileindex)
161 {
162 	struct got_fileindex_entry *entry;
163 
164 	while ((entry = RB_MIN(got_fileindex_tree, &fileindex->entries))) {
165 		RB_REMOVE(got_fileindex_tree, &fileindex->entries, entry);
166 		got_fileindex_entry_free(entry);
167 	}
168 	free(fileindex);
169 }
170 
171 static const struct got_error *
172 write_fileindex_val64(SHA1_CTX *ctx, uint64_t val, FILE *outfile)
173 {
174 	size_t n;
175 
176 	val = htobe64(val);
177 	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
178 	n = fwrite(&val, 1, sizeof(val), outfile);
179 	if (n != sizeof(val))
180 		return got_ferror(outfile, GOT_ERR_IO);
181 	return NULL;
182 }
183 
184 static const struct got_error *
185 write_fileindex_val32(SHA1_CTX *ctx, uint32_t val, FILE *outfile)
186 {
187 	size_t n;
188 
189 	val = htobe32(val);
190 	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
191 	n = fwrite(&val, 1, sizeof(val), outfile);
192 	if (n != sizeof(val))
193 		return got_ferror(outfile, GOT_ERR_IO);
194 	return NULL;
195 }
196 
197 static const struct got_error *
198 write_fileindex_val16(SHA1_CTX *ctx, uint16_t val, FILE *outfile)
199 {
200 	size_t n;
201 
202 	val = htobe16(val);
203 	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
204 	n = fwrite(&val, 1, sizeof(val), outfile);
205 	if (n != sizeof(val))
206 		return got_ferror(outfile, GOT_ERR_IO);
207 	return NULL;
208 }
209 
210 static const struct got_error *
211 write_fileindex_path(SHA1_CTX *ctx, const char *path, FILE *outfile)
212 {
213 	size_t n, len, pad = 0;
214 	static const uint8_t zero[8] = { 0 };
215 
216 	len = strlen(path);
217 	while ((len + pad) % 8 != 0)
218 		pad++;
219 	if (pad == 0)
220 		pad = 8; /* NUL-terminate */
221 
222 	SHA1Update(ctx, path, len);
223 	n = fwrite(path, 1, len, outfile);
224 	if (n != len)
225 		return got_ferror(outfile, GOT_ERR_IO);
226 	SHA1Update(ctx, zero, pad);
227 	n = fwrite(zero, 1, pad, outfile);
228 	if (n != pad)
229 		return got_ferror(outfile, GOT_ERR_IO);
230 	return NULL;
231 }
232 
233 static const struct got_error *
234 write_fileindex_entry(SHA1_CTX *ctx, struct got_fileindex_entry *entry,
235     FILE *outfile)
236 {
237 	const struct got_error *err;
238 	size_t n;
239 
240 	err = write_fileindex_val64(ctx, entry->ctime_sec, outfile);
241 	if (err)
242 		return err;
243 	err = write_fileindex_val64(ctx, entry->ctime_nsec, outfile);
244 	if (err)
245 		return err;
246 	err = write_fileindex_val64(ctx, entry->mtime_sec, outfile);
247 	if (err)
248 		return err;
249 	err = write_fileindex_val64(ctx, entry->mtime_nsec, outfile);
250 	if (err)
251 		return err;
252 
253 	err = write_fileindex_val32(ctx, entry->uid, outfile);
254 	if (err)
255 		return err;
256 	err = write_fileindex_val32(ctx, entry->gid, outfile);
257 	if (err)
258 		return err;
259 	err = write_fileindex_val32(ctx, entry->size, outfile);
260 	if (err)
261 		return err;
262 
263 	err = write_fileindex_val16(ctx, entry->mode, outfile);
264 	if (err)
265 		return err;
266 
267 	SHA1Update(ctx, entry->blob_sha1, SHA1_DIGEST_LENGTH);
268 	n = fwrite(entry->blob_sha1, 1, SHA1_DIGEST_LENGTH, outfile);
269 	if (n != SHA1_DIGEST_LENGTH)
270 		return got_ferror(outfile, GOT_ERR_IO);
271 
272 	SHA1Update(ctx, entry->commit_sha1, SHA1_DIGEST_LENGTH);
273 	n = fwrite(entry->commit_sha1, 1, SHA1_DIGEST_LENGTH, outfile);
274 	if (n != SHA1_DIGEST_LENGTH)
275 		return got_ferror(outfile, GOT_ERR_IO);
276 
277 	err = write_fileindex_val32(ctx, entry->flags, outfile);
278 	if (err)
279 		return err;
280 
281 	err = write_fileindex_path(ctx, entry->path, outfile);
282 	return err;
283 }
284 
285 const struct got_error *
286 got_fileindex_write(struct got_fileindex *fileindex, FILE *outfile)
287 {
288 	const struct got_error *err = NULL;
289 	struct got_fileindex_hdr hdr;
290 	SHA1_CTX ctx;
291 	uint8_t sha1[SHA1_DIGEST_LENGTH];
292 	size_t n;
293 	const size_t len = sizeof(hdr.signature) + sizeof(hdr.version) +
294 	    sizeof(hdr.nentries);
295 	uint8_t buf[len];
296 	struct got_fileindex_entry *entry;
297 
298 	SHA1Init(&ctx);
299 
300 	hdr.signature = htobe32(GOT_FILE_INDEX_SIGNATURE);
301 	hdr.version = htobe32(GOT_FILE_INDEX_VERSION);
302 	hdr.nentries = htobe32(fileindex->nentries);
303 
304 	memcpy(buf, &hdr, len);
305 	SHA1Update(&ctx, buf, len);
306 	n = fwrite(buf, 1, len, outfile);
307 	if (n != len)
308 		return got_ferror(outfile, GOT_ERR_IO);
309 
310 	RB_FOREACH(entry, got_fileindex_tree, &fileindex->entries) {
311 		err = write_fileindex_entry(&ctx, entry, outfile);
312 		if (err)
313 			return err;
314 	}
315 
316 	SHA1Final(sha1, &ctx);
317 	n = fwrite(sha1, 1, sizeof(sha1), outfile);
318 	if (n != sizeof(sha1))
319 		return got_ferror(outfile, GOT_ERR_IO);
320 
321 	return NULL;
322 }
323 
324 static const struct got_error *
325 read_fileindex_val64(uint64_t *val, SHA1_CTX *ctx, FILE *infile)
326 {
327 	size_t n;
328 
329 	n = fread(val, 1, sizeof(*val), infile);
330 	if (n != sizeof(*val))
331 		return got_ferror(infile, GOT_ERR_IO);
332 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
333 	*val = be64toh(*val);
334 	return NULL;
335 }
336 
337 static const struct got_error *
338 read_fileindex_val32(uint32_t *val, SHA1_CTX *ctx, FILE *infile)
339 {
340 	size_t n;
341 
342 	n = fread(val, 1, sizeof(*val), infile);
343 	if (n != sizeof(*val))
344 		return got_ferror(infile, GOT_ERR_IO);
345 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
346 	*val = be32toh(*val);
347 	return NULL;
348 }
349 
350 static const struct got_error *
351 read_fileindex_val16(uint16_t *val, SHA1_CTX *ctx, FILE *infile)
352 {
353 	size_t n;
354 
355 	n = fread(val, 1, sizeof(*val), infile);
356 	if (n != sizeof(*val))
357 		return got_ferror(infile, GOT_ERR_IO);
358 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
359 	*val = be16toh(*val);
360 	return NULL;
361 }
362 
363 static const struct got_error *
364 read_fileindex_path(char **path, SHA1_CTX *ctx, FILE *infile)
365 {
366 	const struct got_error *err = NULL;
367 	uint8_t buf[8];
368 	size_t n, len = 0, totlen = sizeof(buf);
369 
370 	*path = malloc(totlen);
371 	if (*path == NULL)
372 		return got_error_from_errno();
373 
374 	do {
375 		n = fread(buf, 1, sizeof(buf), infile);
376 		if (n != sizeof(buf))
377 			return got_ferror(infile, GOT_ERR_IO);
378 		if (len + sizeof(buf) > totlen) {
379 			char *p = reallocarray(*path, totlen + sizeof(buf), 1);
380 			if (p == NULL) {
381 				err = got_error_from_errno();
382 				break;
383 			}
384 			totlen += sizeof(buf);
385 			*path = p;
386 		}
387 		SHA1Update(ctx, buf, sizeof(buf));
388 		memcpy(*path + len, buf, sizeof(buf));
389 		len += sizeof(buf);
390 	} while (memchr(buf, '\0', sizeof(buf)) == NULL);
391 
392 	if (err) {
393 		free(*path);
394 		*path = NULL;
395 	}
396 	return err;
397 }
398 
399 static const struct got_error *
400 read_fileindex_entry(struct got_fileindex_entry **entryp, SHA1_CTX *ctx,
401     FILE *infile)
402 {
403 	const struct got_error *err;
404 	struct got_fileindex_entry *entry;
405 	size_t n;
406 
407 	*entryp = NULL;
408 
409 	entry = calloc(1, sizeof(*entry));
410 	if (entry == NULL)
411 		return got_error_from_errno();
412 
413 	err = read_fileindex_val64(&entry->ctime_sec, ctx, infile);
414 	if (err)
415 		goto done;
416 	err = read_fileindex_val64(&entry->ctime_nsec, ctx, infile);
417 	if (err)
418 		goto done;
419 	err = read_fileindex_val64(&entry->mtime_sec, ctx, infile);
420 	if (err)
421 		goto done;
422 	err = read_fileindex_val64(&entry->mtime_nsec, ctx, infile);
423 	if (err)
424 		goto done;
425 
426 	err = read_fileindex_val32(&entry->uid, ctx, infile);
427 	if (err)
428 		goto done;
429 	err = read_fileindex_val32(&entry->gid, ctx, infile);
430 	if (err)
431 		goto done;
432 	err = read_fileindex_val32(&entry->size, ctx, infile);
433 	if (err)
434 		goto done;
435 
436 	err = read_fileindex_val16(&entry->mode, ctx, infile);
437 	if (err)
438 		goto done;
439 
440 	n = fread(entry->blob_sha1, 1, SHA1_DIGEST_LENGTH, infile);
441 	if (n != SHA1_DIGEST_LENGTH) {
442 		err = got_ferror(infile, GOT_ERR_IO);
443 		goto done;
444 	}
445 	SHA1Update(ctx, entry->blob_sha1, SHA1_DIGEST_LENGTH);
446 
447 	n = fread(entry->commit_sha1, 1, SHA1_DIGEST_LENGTH, infile);
448 	if (n != SHA1_DIGEST_LENGTH) {
449 		err = got_ferror(infile, GOT_ERR_IO);
450 		goto done;
451 	}
452 	SHA1Update(ctx, entry->commit_sha1, SHA1_DIGEST_LENGTH);
453 
454 	err = read_fileindex_val32(&entry->flags, ctx, infile);
455 	if (err)
456 		goto done;
457 
458 	err = read_fileindex_path(&entry->path, ctx, infile);
459 done:
460 	if (err)
461 		free(entry);
462 	else
463 		*entryp = entry;
464 	return err;
465 }
466 
467 const struct got_error *
468 got_fileindex_read(struct got_fileindex *fileindex, FILE *infile)
469 {
470 	const struct got_error *err = NULL;
471 	struct got_fileindex_hdr hdr;
472 	SHA1_CTX ctx;
473 	struct got_fileindex_entry *entry;
474 	uint8_t sha1_expected[SHA1_DIGEST_LENGTH];
475 	uint8_t sha1[SHA1_DIGEST_LENGTH];
476 	size_t n;
477 	const size_t len = sizeof(hdr.signature) + sizeof(hdr.version) +
478 	    sizeof(hdr.nentries);
479 	uint8_t buf[len];
480 	int i;
481 
482 	SHA1Init(&ctx);
483 
484 	n = fread(buf, 1, len, infile);
485 	if (n != len) {
486 		if (n == 0) /* EOF */
487 			return NULL;
488 		return got_ferror(infile, GOT_ERR_IO);
489 	}
490 
491 	SHA1Update(&ctx, buf, len);
492 
493 	memcpy(&hdr, buf, len);
494 	hdr.signature = be32toh(hdr.signature);
495 	hdr.version = be32toh(hdr.version);
496 	hdr.nentries = be32toh(hdr.nentries);
497 
498 	if (hdr.signature != GOT_FILE_INDEX_SIGNATURE)
499 		return got_error(GOT_ERR_FILEIDX_SIG);
500 	if (hdr.version != GOT_FILE_INDEX_VERSION)
501 		return got_error(GOT_ERR_FILEIDX_VER);
502 
503 	for (i = 0; i < hdr.nentries; i++) {
504 		err = read_fileindex_entry(&entry, &ctx, infile);
505 		if (err)
506 			return err;
507 		err = got_fileindex_entry_add(fileindex, entry);
508 		if (err)
509 			return err;
510 	}
511 
512 	n = fread(sha1_expected, 1, sizeof(sha1_expected), infile);
513 	if (n != sizeof(sha1_expected))
514 		return got_ferror(infile, GOT_ERR_IO);
515 	SHA1Final(sha1, &ctx);
516 	if (memcmp(sha1, sha1_expected, SHA1_DIGEST_LENGTH) != 0)
517 		return got_error(GOT_ERR_FILEIDX_CSUM);
518 
519 	return NULL;
520 }
521 
522 RB_GENERATE(got_fileindex_tree, got_fileindex_entry, entry, got_fileindex_cmp);