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 = 0;
183 	static const uint8_t zero[8] = { 0 };
184 
185 	len = strlen(path);
186 	while ((len + pad) % 8 != 0)
187 		pad++;
188 	if (pad == 0)
189 		pad = 8; /* NUL-terminate */
190 
191 	SHA1Update(ctx, path, len);
192 	n = fwrite(path, 1, len, outfile);
193 	if (n != len)
194 		return got_ferror(outfile, GOT_ERR_IO);
195 	SHA1Update(ctx, zero, pad);
196 	n = fwrite(zero, 1, pad, outfile);
197 	if (n != pad)
198 		return got_ferror(outfile, GOT_ERR_IO);
199 	return NULL;
200 }
201 
202 static const struct got_error *
203 write_fileindex_entry(SHA1_CTX *ctx, struct got_fileindex_entry *entry,
204     FILE *outfile)
205 {
206 	const struct got_error *err;
207 	size_t n;
208 
209 	err = write_fileindex_val64(ctx, entry->ctime_sec, outfile);
210 	if (err)
211 		return err;
212 	err = write_fileindex_val64(ctx, entry->ctime_nsec, outfile);
213 	if (err)
214 		return err;
215 	err = write_fileindex_val64(ctx, entry->mtime_sec, outfile);
216 	if (err)
217 		return err;
218 	err = write_fileindex_val64(ctx, entry->mtime_nsec, outfile);
219 	if (err)
220 		return err;
221 
222 	err = write_fileindex_val32(ctx, entry->uid, outfile);
223 	if (err)
224 		return err;
225 	err = write_fileindex_val32(ctx, entry->gid, outfile);
226 	if (err)
227 		return err;
228 	err = write_fileindex_val32(ctx, entry->size, outfile);
229 	if (err)
230 		return err;
231 
232 	err = write_fileindex_val16(ctx, entry->mode, outfile);
233 	if (err)
234 		return err;
235 
236 	SHA1Update(ctx, entry->blob_sha1, SHA1_DIGEST_LENGTH);
237 	n = fwrite(entry->blob_sha1, 1, SHA1_DIGEST_LENGTH, outfile);
238 	if (n != SHA1_DIGEST_LENGTH)
239 		return got_ferror(outfile, GOT_ERR_IO);
240 
241 	SHA1Update(ctx, entry->commit_sha1, SHA1_DIGEST_LENGTH);
242 	n = fwrite(entry->commit_sha1, 1, SHA1_DIGEST_LENGTH, outfile);
243 	if (n != SHA1_DIGEST_LENGTH)
244 		return got_ferror(outfile, GOT_ERR_IO);
245 
246 	err = write_fileindex_val32(ctx, entry->flags, outfile);
247 	if (err)
248 		return err;
249 
250 	err = write_fileindex_path(ctx, entry->path, outfile);
251 	return err;
252 }
253 
254 const struct got_error *
255 got_fileindex_write(struct got_fileindex *fileindex, FILE *outfile)
256 {
257 	struct got_fileindex_hdr hdr;
258 	struct got_fileindex_entry *entry;
259 	SHA1_CTX ctx;
260 	uint8_t sha1[SHA1_DIGEST_LENGTH];
261 	size_t n;
262 	const size_t len = sizeof(hdr.signature) + sizeof(hdr.version) +
263 	    sizeof(hdr.nentries);
264 	uint8_t buf[len];
265 
266 	SHA1Init(&ctx);
267 
268 	hdr.signature = htobe32(GOT_FILE_INDEX_SIGNATURE);
269 	hdr.version = htobe32(GOT_FILE_INDEX_VERSION);
270 	hdr.nentries = htobe32(fileindex->nentries);
271 
272 	memcpy(buf, &hdr, len);
273 	SHA1Update(&ctx, buf, len);
274 	n = fwrite(buf, 1, len, outfile);
275 	if (n != len)
276 		return got_ferror(outfile, GOT_ERR_IO);
277 
278 	TAILQ_FOREACH(entry, &fileindex->entries, entry) {
279 		const struct got_error *err;
280 		err = write_fileindex_entry(&ctx, entry, outfile);
281 		if (err)
282 			return err;
283 	}
284 
285 	SHA1Final(sha1, &ctx);
286 	n = fwrite(sha1, 1, sizeof(sha1), outfile);
287 	if (n != sizeof(sha1))
288 		return got_ferror(outfile, GOT_ERR_IO);
289 
290 	return NULL;
291 }
292 
293 static const struct got_error *
294 read_fileindex_val64(uint64_t *val, SHA1_CTX *ctx, FILE *infile)
295 {
296 	size_t n;
297 
298 	n = fread(val, 1, sizeof(*val), infile);
299 	if (n != sizeof(*val))
300 		return got_ferror(infile, GOT_ERR_IO);
301 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
302 	*val = be64toh(*val);
303 	return NULL;
304 }
305 
306 static const struct got_error *
307 read_fileindex_val32(uint32_t *val, SHA1_CTX *ctx, FILE *infile)
308 {
309 	size_t n;
310 
311 	n = fread(val, 1, sizeof(*val), infile);
312 	if (n != sizeof(*val))
313 		return got_ferror(infile, GOT_ERR_IO);
314 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
315 	*val = be32toh(*val);
316 	return NULL;
317 }
318 
319 static const struct got_error *
320 read_fileindex_val16(uint16_t *val, SHA1_CTX *ctx, FILE *infile)
321 {
322 	size_t n;
323 
324 	n = fread(val, 1, sizeof(*val), infile);
325 	if (n != sizeof(*val))
326 		return got_ferror(infile, GOT_ERR_IO);
327 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
328 	*val = be16toh(*val);
329 	return NULL;
330 }
331 
332 static const struct got_error *
333 read_fileindex_path(char **path, SHA1_CTX *ctx, FILE *infile)
334 {
335 	const struct got_error *err = NULL;
336 	uint8_t buf[8];
337 	size_t n, len = 0, totlen = sizeof(buf);
338 
339 	*path = malloc(totlen);
340 	if (*path == NULL)
341 		return got_error_from_errno();
342 
343 	do {
344 		n = fread(buf, 1, sizeof(buf), infile);
345 		if (n != sizeof(buf))
346 			return got_ferror(infile, GOT_ERR_IO);
347 		if (len + sizeof(buf) > totlen) {
348 			char *p = reallocarray(*path, totlen + sizeof(buf), 1);
349 			if (p == NULL) {
350 				err = got_error_from_errno();
351 				break;
352 			}
353 			totlen += sizeof(buf);
354 			*path = p;
355 		}
356 		SHA1Update(ctx, buf, sizeof(buf));
357 		memcpy(*path + len, buf, sizeof(buf));
358 		len += sizeof(buf);
359 	} while (memchr(buf, '\0', sizeof(buf)) == NULL);
360 
361 	if (err) {
362 		free(*path);
363 		*path = NULL;
364 	}
365 	return err;
366 }
367 
368 static const struct got_error *
369 read_fileindex_entry(struct got_fileindex_entry **entryp, SHA1_CTX *ctx,
370     FILE *infile)
371 {
372 	const struct got_error *err;
373 	struct got_fileindex_entry *entry;
374 	size_t n;
375 
376 	*entryp = NULL;
377 
378 	entry = calloc(1, sizeof(*entry));
379 	if (entry == NULL)
380 		return got_error_from_errno();
381 
382 	err = read_fileindex_val64(&entry->ctime_sec, ctx, infile);
383 	if (err)
384 		goto done;
385 	err = read_fileindex_val64(&entry->ctime_nsec, ctx, infile);
386 	if (err)
387 		goto done;
388 	err = read_fileindex_val64(&entry->mtime_sec, ctx, infile);
389 	if (err)
390 		goto done;
391 	err = read_fileindex_val64(&entry->mtime_nsec, ctx, infile);
392 	if (err)
393 		goto done;
394 
395 	err = read_fileindex_val32(&entry->uid, ctx, infile);
396 	if (err)
397 		goto done;
398 	err = read_fileindex_val32(&entry->gid, ctx, infile);
399 	if (err)
400 		goto done;
401 	err = read_fileindex_val32(&entry->size, ctx, infile);
402 	if (err)
403 		goto done;
404 
405 	err = read_fileindex_val16(&entry->mode, ctx, infile);
406 	if (err)
407 		goto done;
408 
409 	n = fread(entry->blob_sha1, 1, SHA1_DIGEST_LENGTH, infile);
410 	if (n != SHA1_DIGEST_LENGTH) {
411 		err = got_ferror(infile, GOT_ERR_IO);
412 		goto done;
413 	}
414 	SHA1Update(ctx, entry->blob_sha1, SHA1_DIGEST_LENGTH);
415 
416 	n = fread(entry->commit_sha1, 1, SHA1_DIGEST_LENGTH, infile);
417 	if (n != SHA1_DIGEST_LENGTH) {
418 		err = got_ferror(infile, GOT_ERR_IO);
419 		goto done;
420 	}
421 	SHA1Update(ctx, entry->commit_sha1, SHA1_DIGEST_LENGTH);
422 
423 	err = read_fileindex_val32(&entry->flags, ctx, infile);
424 	if (err)
425 		goto done;
426 
427 	err = read_fileindex_path(&entry->path, ctx, infile);
428 done:
429 	if (err)
430 		free(entry);
431 	else
432 		*entryp = entry;
433 	return err;
434 }
435 
436 const struct got_error *
437 got_fileindex_read(struct got_fileindex *fileindex, FILE *infile)
438 {
439 	const struct got_error *err = NULL;
440 	struct got_fileindex_hdr hdr;
441 	SHA1_CTX ctx;
442 	struct got_fileindex_entry *entry;
443 	uint8_t sha1_expected[SHA1_DIGEST_LENGTH];
444 	uint8_t sha1[SHA1_DIGEST_LENGTH];
445 	size_t n;
446 	const size_t len = sizeof(hdr.signature) + sizeof(hdr.version) +
447 	    sizeof(hdr.nentries);
448 	uint8_t buf[len];
449 	int i;
450 
451 	SHA1Init(&ctx);
452 
453 	n = fread(buf, 1, len, infile);
454 	if (n != len) {
455 		if (n == 0) /* EOF */
456 			return NULL;
457 		return got_ferror(infile, GOT_ERR_IO);
458 	}
459 
460 	SHA1Update(&ctx, buf, len);
461 
462 	memcpy(&hdr, buf, len);
463 	hdr.signature = be32toh(hdr.signature);
464 	hdr.version = be32toh(hdr.version);
465 	hdr.nentries = be32toh(hdr.nentries);
466 
467 	if (hdr.signature != GOT_FILE_INDEX_SIGNATURE)
468 		return got_error(GOT_ERR_FILEIDX_SIG);
469 	if (hdr.version != GOT_FILE_INDEX_VERSION)
470 		return got_error(GOT_ERR_FILEIDX_VER);
471 
472 	for (i = 0; i < hdr.nentries; i++) {
473 		err = read_fileindex_entry(&entry, &ctx, infile);
474 		if (err)
475 			return err;
476 		err = got_fileindex_entry_add(fileindex, entry);
477 		if (err)
478 			return err;
479 	}
480 
481 	n = fread(sha1_expected, 1, sizeof(sha1_expected), infile);
482 	if (n != sizeof(sha1_expected))
483 		return got_ferror(infile, GOT_ERR_IO);
484 	SHA1Final(sha1, &ctx);
485 	if (memcmp(sha1, sha1_expected, SHA1_DIGEST_LENGTH) != 0)
486 		return got_error(GOT_ERR_FILEIDX_CSUM);
487 
488 	return NULL;
489 }