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 {
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_free(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_alloc(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_free(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_free(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 	size_t n;
120 
121 	val = htobe64(val);
122 	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
123 	n = fwrite(&val, 1, sizeof(val), outfile);
124 	if (n != sizeof(val))
125 		return got_ferror(outfile, GOT_ERR_IO);
126 	return NULL;
127 }
128 
129 static const struct got_error *
130 write_fileindex_val32(SHA1_CTX *ctx, uint32_t val, FILE *outfile)
131 {
132 	size_t n;
133 
134 	val = htobe32(val);
135 	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
136 	n = fwrite(&val, 1, sizeof(val), outfile);
137 	if (n != sizeof(val))
138 		return got_ferror(outfile, GOT_ERR_IO);
139 	return NULL;
140 }
141 
142 static const struct got_error *
143 write_fileindex_val16(SHA1_CTX *ctx, uint16_t val, FILE *outfile)
144 {
145 	size_t n;
146 
147 	val = htobe16(val);
148 	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
149 	n = fwrite(&val, 1, sizeof(val), outfile);
150 	if (n != sizeof(val))
151 		return got_ferror(outfile, GOT_ERR_IO);
152 	return NULL;
153 }
154 
155 static const struct got_error *
156 write_fileindex_path(SHA1_CTX *ctx, const char *path, FILE *outfile)
157 {
158 	size_t n, len, pad;
159 	static const uint8_t zero[8] = { 0 };
160 
161 	len = strlen(path);
162 	pad = (len % 8);
163 
164 	SHA1Update(ctx, path, len);
165 	n = fwrite(path, 1, len, outfile);
166 	if (n != len)
167 		return got_ferror(outfile, GOT_ERR_IO);
168 	if (pad == 0)
169 		return NULL;
170 	SHA1Update(ctx, zero, pad);
171 	n = fwrite(zero, 1, pad, outfile);
172 	if (n != pad)
173 		return got_ferror(outfile, GOT_ERR_IO);
174 	return NULL;
175 }
176 
177 static const struct got_error *
178 write_fileindex_entry(SHA1_CTX *ctx, struct got_fileindex_entry *entry,
179     FILE *outfile)
180 {
181 	const struct got_error *err;
182 	size_t n;
183 
184 	err = write_fileindex_val64(ctx, entry->ctime_sec, outfile);
185 	if (err)
186 		return err;
187 	err = write_fileindex_val64(ctx, entry->ctime_nsec, outfile);
188 	if (err)
189 		return err;
190 	err = write_fileindex_val64(ctx, entry->mtime_sec, outfile);
191 	if (err)
192 		return err;
193 	err = write_fileindex_val64(ctx, entry->mtime_nsec, outfile);
194 	if (err)
195 		return err;
196 
197 	err = write_fileindex_val32(ctx, entry->uid, outfile);
198 	if (err)
199 		return err;
200 	err = write_fileindex_val32(ctx, entry->gid, outfile);
201 	if (err)
202 		return err;
203 	err = write_fileindex_val32(ctx, entry->size, outfile);
204 	if (err)
205 		return err;
206 
207 	err = write_fileindex_val16(ctx, entry->mode, outfile);
208 	if (err)
209 		return err;
210 
211 	SHA1Update(ctx, entry->blob_sha1, SHA1_DIGEST_LENGTH);
212 	n = fwrite(entry->blob_sha1, 1, SHA1_DIGEST_LENGTH, outfile);
213 	if (n != SHA1_DIGEST_LENGTH)
214 		return got_ferror(outfile, GOT_ERR_IO);
215 
216 	err = write_fileindex_val32(ctx, entry->flags, outfile);
217 	if (err)
218 		return err;
219 
220 	err = write_fileindex_path(ctx, entry->path, outfile);
221 	return err;
222 }
223 
224 const struct got_error *
225 got_fileindex_write(struct got_fileindex *fileindex, FILE *outfile)
226 {
227 	struct got_fileindex_hdr hdr;
228 	struct got_fileindex_entry *entry;
229 	SHA1_CTX ctx;
230 	uint8_t sha1[SHA1_DIGEST_LENGTH];
231 	size_t n;
232 	const size_t len = sizeof(hdr.signature) + sizeof(hdr.version) +
233 	    sizeof(hdr.nentries);
234 	uint8_t buf[len];
235 
236 	SHA1Init(&ctx);
237 
238 	hdr.signature = htobe32(GOT_FILE_INDEX_SIGNATURE);
239 	hdr.version = htobe32(GOT_FILE_INDEX_VERSION);
240 	hdr.nentries = htobe32(fileindex->nentries);
241 
242 	memcpy(buf, &hdr, len);
243 	SHA1Update(&ctx, buf, len);
244 	n = fwrite(buf, 1, len, outfile);
245 	if (n != len)
246 		return got_ferror(outfile, GOT_ERR_IO);
247 
248 	TAILQ_FOREACH(entry, &fileindex->entries, entry) {
249 		const struct got_error *err;
250 		err = write_fileindex_entry(&ctx, entry, outfile);
251 		if (err)
252 			return err;
253 	}
254 
255 	SHA1Final(sha1, &ctx);
256 	n = fwrite(sha1, 1, sizeof(sha1), outfile);
257 	if (n != sizeof(sha1))
258 		return got_ferror(outfile, GOT_ERR_IO);
259 
260 	return NULL;
261 }
262 
263 static const struct got_error *
264 read_fileindex_val64(uint64_t *val, SHA1_CTX *ctx, FILE *infile)
265 {
266 	size_t n;
267 
268 	n = fread(val, 1, sizeof(*val), infile);
269 	if (n != sizeof(*val))
270 		return got_ferror(infile, GOT_ERR_IO);
271 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
272 	*val = be64toh(*val);
273 	return NULL;
274 }
275 
276 static const struct got_error *
277 read_fileindex_val32(uint32_t *val, SHA1_CTX *ctx, FILE *infile)
278 {
279 	size_t n;
280 
281 	n = fread(val, 1, sizeof(*val), infile);
282 	if (n != sizeof(*val))
283 		return got_ferror(infile, GOT_ERR_IO);
284 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
285 	*val = be32toh(*val);
286 	return NULL;
287 }
288 
289 static const struct got_error *
290 read_fileindex_val16(uint16_t *val, SHA1_CTX *ctx, FILE *infile)
291 {
292 	size_t n;
293 
294 	n = fread(val, 1, sizeof(*val), infile);
295 	if (n != sizeof(*val))
296 		return got_ferror(infile, GOT_ERR_IO);
297 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
298 	*val = be16toh(*val);
299 	return NULL;
300 }
301 
302 static const struct got_error *
303 read_fileindex_path(char **path, SHA1_CTX *ctx, FILE *infile)
304 {
305 	const struct got_error *err = NULL;
306 	uint8_t buf[8];
307 	size_t n, len = 0, totlen = sizeof(buf);
308 
309 	*path = malloc(totlen);
310 	if (*path == NULL)
311 		return got_error_from_errno();
312 
313 	do {
314 		n = fread(buf, 1, sizeof(buf), infile);
315 		if (n != sizeof(buf))
316 			return got_ferror(infile, GOT_ERR_IO);
317 		if (len + sizeof(buf) > totlen) {
318 			char *p = reallocarray(*path, totlen + sizeof(buf), 1);
319 			if (p == NULL) {
320 				err = got_error_from_errno();
321 				break;
322 			}
323 			totlen += sizeof(buf);
324 			*path = p;
325 		}
326 		SHA1Update(ctx, buf, sizeof(buf));
327 		memcpy(*path + len, buf, sizeof(buf));
328 		len += sizeof(buf);
329 	} while (strchr(buf, '\0') == NULL);
330 
331 	if (err) {
332 		free(*path);
333 		*path = NULL;
334 	}
335 	return err;
336 }
337 
338 static const struct got_error *
339 read_fileindex_entry(struct got_fileindex_entry **entryp, SHA1_CTX *ctx,
340     FILE *infile)
341 {
342 	const struct got_error *err;
343 	struct got_fileindex_entry *entry;
344 	size_t n;
345 
346 	*entryp = NULL;
347 
348 	entry = calloc(1, sizeof(*entry));
349 	if (entry == NULL)
350 		return got_error_from_errno();
351 
352 	err = read_fileindex_val64(&entry->ctime_sec, ctx, infile);
353 	if (err)
354 		goto done;
355 	err = read_fileindex_val64(&entry->ctime_nsec, ctx, infile);
356 	if (err)
357 		goto done;
358 	err = read_fileindex_val64(&entry->mtime_sec, ctx, infile);
359 	if (err)
360 		goto done;
361 	err = read_fileindex_val64(&entry->mtime_nsec, ctx, infile);
362 	if (err)
363 		goto done;
364 
365 	err = read_fileindex_val32(&entry->uid, ctx, infile);
366 	if (err)
367 		goto done;
368 	err = read_fileindex_val32(&entry->gid, ctx, infile);
369 	if (err)
370 		goto done;
371 	err = read_fileindex_val32(&entry->size, ctx, infile);
372 	if (err)
373 		goto done;
374 
375 	err = read_fileindex_val16(&entry->mode, ctx, infile);
376 	if (err)
377 		goto done;
378 
379 	n = fread(entry->blob_sha1, 1, SHA1_DIGEST_LENGTH, infile);
380 	if (n != SHA1_DIGEST_LENGTH) {
381 		err = got_ferror(infile, GOT_ERR_IO);
382 		goto done;
383 	}
384 	SHA1Update(ctx, entry->blob_sha1, SHA1_DIGEST_LENGTH);
385 
386 	err = read_fileindex_val32(&entry->flags, ctx, infile);
387 	if (err)
388 		goto done;
389 
390 	err = read_fileindex_path(&entry->path, ctx, infile);
391 done:
392 	if (err)
393 		free(entry);
394 	else
395 		*entryp = entry;
396 	return err;
397 }
398 
399 const struct got_error *
400 got_fileindex_read(struct got_fileindex *fileindex, FILE *infile)
401 {
402 	const struct got_error *err = NULL;
403 	struct got_fileindex_hdr hdr;
404 	SHA1_CTX ctx;
405 	struct got_fileindex_entry *entry;
406 	uint8_t sha1_expected[SHA1_DIGEST_LENGTH];
407 	uint8_t sha1[SHA1_DIGEST_LENGTH];
408 	size_t n;
409 	const size_t len = sizeof(hdr.signature) + sizeof(hdr.version) +
410 	    sizeof(hdr.nentries);
411 	uint8_t buf[len];
412 	int i;
413 
414 	SHA1Init(&ctx);
415 
416 	n = fread(buf, 1, len, infile);
417 	if (n != len)
418 		return got_ferror(infile, GOT_ERR_IO);
419 
420 	SHA1Update(&ctx, buf, len);
421 
422 	memcpy(&hdr, buf, len);
423 	hdr.signature = be32toh(hdr.signature);
424 	hdr.version = be32toh(hdr.version);
425 	hdr.nentries = be32toh(hdr.nentries);
426 
427 	if (hdr.signature != GOT_FILE_INDEX_SIGNATURE)
428 		return got_error(GOT_ERR_FILEIDX_SIG);
429 	if (hdr.version != GOT_FILE_INDEX_VERSION)
430 		return got_error(GOT_ERR_FILEIDX_VER);
431 
432 	for (i = 0; i < hdr.nentries; i++) {
433 		err = read_fileindex_entry(&entry, &ctx, infile);
434 		if (err)
435 			return err;
436 		err = got_fileindex_entry_add(fileindex, entry);
437 		if (err)
438 			return err;
439 	}
440 
441 	n = fread(sha1_expected, 1, sizeof(sha1_expected), infile);
442 	if (n != sizeof(sha1_expected))
443 		return got_ferror(infile, GOT_ERR_IO);
444 	SHA1Final(sha1, &ctx);
445 	if (memcmp(sha1, sha1_expected, SHA1_DIGEST_LENGTH) != 0)
446 		return got_error(GOT_ERR_FILEIDX_CSUM);
447 
448 	return NULL;
449 }