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/stat.h>
19 
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <sha1.h>
24 #include <endian.h>
25 
26 #include "got_error.h"
27 
28 #include "got_lib_fileindex.h"
29 
30 const struct got_error *
31 got_fileindex_entry_update(struct got_fileindex_entry *entry,
32     const char *ondisk_path, uint8_t *blob_sha1, uint8_t *commit_sha1)
33 {
34 	struct stat sb;
35 
36 	if (lstat(ondisk_path, &sb) != 0)
37 		return got_error_from_errno();
38 
39 	entry->ctime_sec = sb.st_ctime;
40 	entry->ctime_nsec = sb.st_ctimensec;
41 	entry->mtime_sec = sb.st_mtime;
42 	entry->mtime_nsec = sb.st_mtimensec;
43 	entry->uid = sb.st_uid;
44 	entry->gid = sb.st_gid;
45 	entry->size = (sb.st_size & 0xffffffff);
46 	if (sb.st_mode & S_IFLNK)
47 		entry->mode = GOT_INDEX_ENTRY_MODE_SYMLINK;
48 	else
49 		entry->mode = GOT_INDEX_ENTRY_MODE_REGULAR_FILE;
50 	entry->mode |= ((sb.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO)) <<
51 	    GOT_INDEX_ENTRY_MODE_PERMS_SHIFT);
52 	memcpy(entry->blob_sha1, blob_sha1, SHA1_DIGEST_LENGTH);
53 	memcpy(entry->commit_sha1, commit_sha1, SHA1_DIGEST_LENGTH);
54 
55 	return NULL;
56 }
57 
58 const struct got_error *
59 got_fileindex_entry_alloc(struct got_fileindex_entry **entry,
60     const char *ondisk_path, const char *relpath, uint8_t *blob_sha1,
61     uint8_t *commit_sha1)
62 {
63 	size_t len;
64 
65 	*entry = calloc(1, sizeof(**entry));
66 	if (*entry == NULL)
67 		return got_error_from_errno();
68 
69 	(*entry)->path = strdup(relpath);
70 	if ((*entry)->path == NULL) {
71 		const struct got_error *err = got_error_from_errno();
72 		free(*entry);
73 		*entry = NULL;
74 		return err;
75 	}
76 
77 	len = strlen(relpath);
78 	if (len > GOT_INDEX_ENTRY_F_PATH_LEN)
79 		len = GOT_INDEX_ENTRY_F_PATH_LEN;
80 	(*entry)->flags |= len;
81 
82 	return got_fileindex_entry_update(*entry, ondisk_path, blob_sha1,
83 	    commit_sha1);
84 }
85 
86 void
87 got_fileindex_entry_free(struct got_fileindex_entry *entry)
88 {
89 	free(entry->path);
90 	free(entry);
91 }
92 
93 const struct got_error *
94 got_fileindex_entry_add(struct got_fileindex *fileindex,
95     struct got_fileindex_entry *entry)
96 {
97 	/* TODO keep entries sorted by name */
98 	TAILQ_INSERT_TAIL(&fileindex->entries, entry, entry);
99 	fileindex->nentries++;
100 	return NULL;
101 }
102 
103 struct got_fileindex_entry *
104 got_fileindex_entry_get(struct got_fileindex *fileindex, const char *path)
105 {
106 	struct got_fileindex_entry *entry;
107 	TAILQ_FOREACH(entry, &fileindex->entries, entry) {
108 		if (strcmp(entry->path, path) == 0)
109 			return entry;
110 	}
111 
112 	return NULL;
113 }
114 
115 struct got_fileindex *
116 got_fileindex_alloc(void)
117 {
118 	struct got_fileindex *fileindex;
119 
120 	fileindex = calloc(1, sizeof(*fileindex));
121 	if (fileindex)
122 		TAILQ_INIT(&fileindex->entries);
123 	return fileindex;
124 }
125 
126 void
127 got_fileindex_free(struct got_fileindex *fileindex)
128 {
129 	struct got_fileindex_entry *entry;
130 
131 	while (!TAILQ_EMPTY(&fileindex->entries)) {
132 		entry = TAILQ_FIRST(&fileindex->entries);
133 		TAILQ_REMOVE(&fileindex->entries, entry, entry);
134 		got_fileindex_entry_free(entry);
135 		fileindex->nentries--;
136 	}
137 	free(fileindex);
138 }
139 
140 static const struct got_error *
141 write_fileindex_val64(SHA1_CTX *ctx, uint64_t val, FILE *outfile)
142 {
143 	size_t n;
144 
145 	val = htobe64(val);
146 	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
147 	n = fwrite(&val, 1, sizeof(val), outfile);
148 	if (n != sizeof(val))
149 		return got_ferror(outfile, GOT_ERR_IO);
150 	return NULL;
151 }
152 
153 static const struct got_error *
154 write_fileindex_val32(SHA1_CTX *ctx, uint32_t val, FILE *outfile)
155 {
156 	size_t n;
157 
158 	val = htobe32(val);
159 	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
160 	n = fwrite(&val, 1, sizeof(val), outfile);
161 	if (n != sizeof(val))
162 		return got_ferror(outfile, GOT_ERR_IO);
163 	return NULL;
164 }
165 
166 static const struct got_error *
167 write_fileindex_val16(SHA1_CTX *ctx, uint16_t val, FILE *outfile)
168 {
169 	size_t n;
170 
171 	val = htobe16(val);
172 	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
173 	n = fwrite(&val, 1, sizeof(val), outfile);
174 	if (n != sizeof(val))
175 		return got_ferror(outfile, GOT_ERR_IO);
176 	return NULL;
177 }
178 
179 static const struct got_error *
180 write_fileindex_path(SHA1_CTX *ctx, const char *path, FILE *outfile)
181 {
182 	size_t n, len, pad;
183 	static const uint8_t zero[8] = { 0 };
184 
185 	len = strlen(path);
186 	pad = (len % 8);
187 
188 	SHA1Update(ctx, path, len);
189 	n = fwrite(path, 1, len, outfile);
190 	if (n != len)
191 		return got_ferror(outfile, GOT_ERR_IO);
192 	if (pad == 0)
193 		return NULL;
194 	SHA1Update(ctx, zero, pad);
195 	n = fwrite(zero, 1, pad, outfile);
196 	if (n != pad)
197 		return got_ferror(outfile, GOT_ERR_IO);
198 	return NULL;
199 }
200 
201 static const struct got_error *
202 write_fileindex_entry(SHA1_CTX *ctx, struct got_fileindex_entry *entry,
203     FILE *outfile)
204 {
205 	const struct got_error *err;
206 	size_t n;
207 
208 	err = write_fileindex_val64(ctx, entry->ctime_sec, outfile);
209 	if (err)
210 		return err;
211 	err = write_fileindex_val64(ctx, entry->ctime_nsec, outfile);
212 	if (err)
213 		return err;
214 	err = write_fileindex_val64(ctx, entry->mtime_sec, outfile);
215 	if (err)
216 		return err;
217 	err = write_fileindex_val64(ctx, entry->mtime_nsec, outfile);
218 	if (err)
219 		return err;
220 
221 	err = write_fileindex_val32(ctx, entry->uid, outfile);
222 	if (err)
223 		return err;
224 	err = write_fileindex_val32(ctx, entry->gid, outfile);
225 	if (err)
226 		return err;
227 	err = write_fileindex_val32(ctx, entry->size, outfile);
228 	if (err)
229 		return err;
230 
231 	err = write_fileindex_val16(ctx, entry->mode, outfile);
232 	if (err)
233 		return err;
234 
235 	SHA1Update(ctx, entry->blob_sha1, SHA1_DIGEST_LENGTH);
236 	n = fwrite(entry->blob_sha1, 1, SHA1_DIGEST_LENGTH, outfile);
237 	if (n != SHA1_DIGEST_LENGTH)
238 		return got_ferror(outfile, GOT_ERR_IO);
239 
240 	SHA1Update(ctx, entry->commit_sha1, SHA1_DIGEST_LENGTH);
241 	n = fwrite(entry->commit_sha1, 1, SHA1_DIGEST_LENGTH, outfile);
242 	if (n != SHA1_DIGEST_LENGTH)
243 		return got_ferror(outfile, GOT_ERR_IO);
244 
245 	err = write_fileindex_val32(ctx, entry->flags, outfile);
246 	if (err)
247 		return err;
248 
249 	err = write_fileindex_path(ctx, entry->path, outfile);
250 	return err;
251 }
252 
253 const struct got_error *
254 got_fileindex_write(struct got_fileindex *fileindex, FILE *outfile)
255 {
256 	struct got_fileindex_hdr hdr;
257 	struct got_fileindex_entry *entry;
258 	SHA1_CTX ctx;
259 	uint8_t sha1[SHA1_DIGEST_LENGTH];
260 	size_t n;
261 	const size_t len = sizeof(hdr.signature) + sizeof(hdr.version) +
262 	    sizeof(hdr.nentries);
263 	uint8_t buf[len];
264 
265 	SHA1Init(&ctx);
266 
267 	hdr.signature = htobe32(GOT_FILE_INDEX_SIGNATURE);
268 	hdr.version = htobe32(GOT_FILE_INDEX_VERSION);
269 	hdr.nentries = htobe32(fileindex->nentries);
270 
271 	memcpy(buf, &hdr, len);
272 	SHA1Update(&ctx, buf, len);
273 	n = fwrite(buf, 1, len, outfile);
274 	if (n != len)
275 		return got_ferror(outfile, GOT_ERR_IO);
276 
277 	TAILQ_FOREACH(entry, &fileindex->entries, entry) {
278 		const struct got_error *err;
279 		err = write_fileindex_entry(&ctx, entry, outfile);
280 		if (err)
281 			return err;
282 	}
283 
284 	SHA1Final(sha1, &ctx);
285 	n = fwrite(sha1, 1, sizeof(sha1), outfile);
286 	if (n != sizeof(sha1))
287 		return got_ferror(outfile, GOT_ERR_IO);
288 
289 	return NULL;
290 }
291 
292 static const struct got_error *
293 read_fileindex_val64(uint64_t *val, SHA1_CTX *ctx, FILE *infile)
294 {
295 	size_t n;
296 
297 	n = fread(val, 1, sizeof(*val), infile);
298 	if (n != sizeof(*val))
299 		return got_ferror(infile, GOT_ERR_IO);
300 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
301 	*val = be64toh(*val);
302 	return NULL;
303 }
304 
305 static const struct got_error *
306 read_fileindex_val32(uint32_t *val, SHA1_CTX *ctx, FILE *infile)
307 {
308 	size_t n;
309 
310 	n = fread(val, 1, sizeof(*val), infile);
311 	if (n != sizeof(*val))
312 		return got_ferror(infile, GOT_ERR_IO);
313 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
314 	*val = be32toh(*val);
315 	return NULL;
316 }
317 
318 static const struct got_error *
319 read_fileindex_val16(uint16_t *val, SHA1_CTX *ctx, FILE *infile)
320 {
321 	size_t n;
322 
323 	n = fread(val, 1, sizeof(*val), infile);
324 	if (n != sizeof(*val))
325 		return got_ferror(infile, GOT_ERR_IO);
326 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
327 	*val = be16toh(*val);
328 	return NULL;
329 }
330 
331 static const struct got_error *
332 read_fileindex_path(char **path, SHA1_CTX *ctx, FILE *infile)
333 {
334 	const struct got_error *err = NULL;
335 	uint8_t buf[8];
336 	size_t n, len = 0, totlen = sizeof(buf);
337 
338 	*path = malloc(totlen);
339 	if (*path == NULL)
340 		return got_error_from_errno();
341 
342 	do {
343 		n = fread(buf, 1, sizeof(buf), infile);
344 		if (n != sizeof(buf))
345 			return got_ferror(infile, GOT_ERR_IO);
346 		if (len + sizeof(buf) > totlen) {
347 			char *p = reallocarray(*path, totlen + sizeof(buf), 1);
348 			if (p == NULL) {
349 				err = got_error_from_errno();
350 				break;
351 			}
352 			totlen += sizeof(buf);
353 			*path = p;
354 		}
355 		SHA1Update(ctx, buf, sizeof(buf));
356 		memcpy(*path + len, buf, sizeof(buf));
357 		len += sizeof(buf);
358 	} while (strchr(buf, '\0') == NULL);
359 
360 	if (err) {
361 		free(*path);
362 		*path = NULL;
363 	}
364 	return err;
365 }
366 
367 static const struct got_error *
368 read_fileindex_entry(struct got_fileindex_entry **entryp, SHA1_CTX *ctx,
369     FILE *infile)
370 {
371 	const struct got_error *err;
372 	struct got_fileindex_entry *entry;
373 	size_t n;
374 
375 	*entryp = NULL;
376 
377 	entry = calloc(1, sizeof(*entry));
378 	if (entry == NULL)
379 		return got_error_from_errno();
380 
381 	err = read_fileindex_val64(&entry->ctime_sec, ctx, infile);
382 	if (err)
383 		goto done;
384 	err = read_fileindex_val64(&entry->ctime_nsec, ctx, infile);
385 	if (err)
386 		goto done;
387 	err = read_fileindex_val64(&entry->mtime_sec, ctx, infile);
388 	if (err)
389 		goto done;
390 	err = read_fileindex_val64(&entry->mtime_nsec, ctx, infile);
391 	if (err)
392 		goto done;
393 
394 	err = read_fileindex_val32(&entry->uid, ctx, infile);
395 	if (err)
396 		goto done;
397 	err = read_fileindex_val32(&entry->gid, ctx, infile);
398 	if (err)
399 		goto done;
400 	err = read_fileindex_val32(&entry->size, ctx, infile);
401 	if (err)
402 		goto done;
403 
404 	err = read_fileindex_val16(&entry->mode, ctx, infile);
405 	if (err)
406 		goto done;
407 
408 	n = fread(entry->blob_sha1, 1, SHA1_DIGEST_LENGTH, infile);
409 	if (n != SHA1_DIGEST_LENGTH) {
410 		err = got_ferror(infile, GOT_ERR_IO);
411 		goto done;
412 	}
413 	SHA1Update(ctx, entry->blob_sha1, SHA1_DIGEST_LENGTH);
414 
415 	n = fread(entry->commit_sha1, 1, SHA1_DIGEST_LENGTH, infile);
416 	if (n != SHA1_DIGEST_LENGTH) {
417 		err = got_ferror(infile, GOT_ERR_IO);
418 		goto done;
419 	}
420 	SHA1Update(ctx, entry->commit_sha1, SHA1_DIGEST_LENGTH);
421 
422 	err = read_fileindex_val32(&entry->flags, ctx, infile);
423 	if (err)
424 		goto done;
425 
426 	err = read_fileindex_path(&entry->path, ctx, infile);
427 done:
428 	if (err)
429 		free(entry);
430 	else
431 		*entryp = entry;
432 	return err;
433 }
434 
435 const struct got_error *
436 got_fileindex_read(struct got_fileindex *fileindex, FILE *infile)
437 {
438 	const struct got_error *err = NULL;
439 	struct got_fileindex_hdr hdr;
440 	SHA1_CTX ctx;
441 	struct got_fileindex_entry *entry;
442 	uint8_t sha1_expected[SHA1_DIGEST_LENGTH];
443 	uint8_t sha1[SHA1_DIGEST_LENGTH];
444 	size_t n;
445 	const size_t len = sizeof(hdr.signature) + sizeof(hdr.version) +
446 	    sizeof(hdr.nentries);
447 	uint8_t buf[len];
448 	int i;
449 
450 	SHA1Init(&ctx);
451 
452 	n = fread(buf, 1, len, infile);
453 	if (n != len) {
454 		if (n == 0) /* EOF */
455 			return NULL;
456 		return got_ferror(infile, GOT_ERR_IO);
457 	}
458 
459 	SHA1Update(&ctx, buf, len);
460 
461 	memcpy(&hdr, buf, len);
462 	hdr.signature = be32toh(hdr.signature);
463 	hdr.version = be32toh(hdr.version);
464 	hdr.nentries = be32toh(hdr.nentries);
465 
466 	if (hdr.signature != GOT_FILE_INDEX_SIGNATURE)
467 		return got_error(GOT_ERR_FILEIDX_SIG);
468 	if (hdr.version != GOT_FILE_INDEX_VERSION)
469 		return got_error(GOT_ERR_FILEIDX_VER);
470 
471 	for (i = 0; i < hdr.nentries; i++) {
472 		err = read_fileindex_entry(&entry, &ctx, infile);
473 		if (err)
474 			return err;
475 		err = got_fileindex_entry_add(fileindex, entry);
476 		if (err)
477 			return err;
478 	}
479 
480 	n = fread(sha1_expected, 1, sizeof(sha1_expected), infile);
481 	if (n != sizeof(sha1_expected))
482 		return got_ferror(infile, GOT_ERR_IO);
483 	SHA1Final(sha1, &ctx);
484 	if (memcmp(sha1, sha1_expected, SHA1_DIGEST_LENGTH) != 0)
485 		return got_error(GOT_ERR_FILEIDX_CSUM);
486 
487 	return NULL;
488 }