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