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