1 /*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 extern "C" {
18 #include <fec.h>
19 }
20
21 #undef NDEBUG
22
23 #include <assert.h>
24 #include <errno.h>
25 #include <getopt.h>
26 #include <fcntl.h>
27 #include <pthread.h>
28 #include <stdbool.h>
29 #include <stdlib.h>
30 #include <string.h>
31
32 #include <android-base/file.h>
33 #include "image.h"
34
35 enum {
36 MODE_ENCODE,
37 MODE_DECODE,
38 MODE_PRINTSIZE,
39 MODE_GETECCSTART,
40 MODE_GETVERITYSTART
41 };
42
encode_rs(struct image_proc_ctx * ctx)43 static void encode_rs(struct image_proc_ctx *ctx)
44 {
45 struct image *fcx = ctx->ctx;
46 int j;
47 uint8_t data[fcx->rs_n];
48 uint64_t i;
49
50 for (i = ctx->start; i < ctx->end; i += fcx->rs_n) {
51 for (j = 0; j < fcx->rs_n; ++j) {
52 data[j] = image_get_interleaved_byte(i + j, fcx);
53 }
54
55 encode_rs_char(ctx->rs, data, &fcx->fec[ctx->fec_pos]);
56 ctx->fec_pos += fcx->roots;
57 }
58 }
59
decode_rs(struct image_proc_ctx * ctx)60 static void decode_rs(struct image_proc_ctx *ctx)
61 {
62 struct image *fcx = ctx->ctx;
63 int j, rv;
64 uint8_t data[fcx->rs_n + fcx->roots];
65 uint64_t i;
66
67 assert(sizeof(data) == FEC_RSM);
68
69 for (i = ctx->start; i < ctx->end; i += fcx->rs_n) {
70 for (j = 0; j < fcx->rs_n; ++j) {
71 data[j] = image_get_interleaved_byte(i + j, fcx);
72 }
73
74 memcpy(&data[fcx->rs_n], &fcx->fec[ctx->fec_pos], fcx->roots);
75 rv = decode_rs_char(ctx->rs, data, NULL, 0);
76
77 if (rv < 0) {
78 FATAL("failed to recover [%" PRIu64 ", %" PRIu64 ")\n",
79 i, i + fcx->rs_n);
80 } else if (rv > 0) {
81 /* copy corrected data to output */
82 for (j = 0; j < fcx->rs_n; ++j) {
83 image_set_interleaved_byte(i + j, fcx, data[j]);
84 }
85
86 ctx->rv += rv;
87 }
88
89 ctx->fec_pos += fcx->roots;
90 }
91 }
92
usage()93 static int usage()
94 {
95 printf("fec: a tool for encoding and decoding files using RS(255, N).\n"
96 "\n"
97 "usage: fec <mode> [ <options> ] [ <data> <fec> [ <output> ] ]\n"
98 "mode:\n"
99 " -e --encode encode (default)\n"
100 " -d --decode decode\n"
101 " -s, --print-fec-size=<data size> print FEC size\n"
102 " -E, --get-ecc-start=data print ECC offset in data\n"
103 " -V, --get-verity-start=data print verity offset\n"
104 "options:\n"
105 " -h show this help\n"
106 " -v enable verbose logging\n"
107 " -r, --roots=<bytes> number of parity bytes\n"
108 " -m, --mmap use memory mapping\n"
109 " -j, --threads=<threads> number of threads to use\n"
110 " -S treat data as a sparse file\n"
111 "decoding options:\n"
112 " -i, --inplace correct <data> in place\n"
113 );
114
115 return 1;
116 }
117
parse_arg(const char * arg,const char * name,uint64_t maxval)118 static uint64_t parse_arg(const char *arg, const char *name, uint64_t maxval)
119 {
120 char* endptr;
121 errno = 0;
122
123 unsigned long long int value = strtoull(arg, &endptr, 0);
124
125 if (arg[0] == '\0' || *endptr != '\0' ||
126 (errno == ERANGE && value == ULLONG_MAX)) {
127 FATAL("invalid value of %s\n", name);
128 }
129 if (value > maxval) {
130 FATAL("value of roots too large (max. %" PRIu64 ")\n", maxval);
131 }
132
133 return (uint64_t)value;
134 }
135
print_size(image & ctx)136 static int print_size(image& ctx)
137 {
138 /* output size including header */
139 printf("%" PRIu64 "\n", fec_ecc_get_size(ctx.inp_size, ctx.roots));
140 return 0;
141 }
142
get_start(int mode,const std::string & filename)143 static int get_start(int mode, const std::string& filename)
144 {
145 fec::io fh(filename, O_RDONLY, FEC_VERITY_DISABLE);
146
147 if (!fh) {
148 FATAL("failed to open input\n");
149 }
150
151 if (mode == MODE_GETECCSTART) {
152 fec_ecc_metadata data;
153
154 if (!fh.get_ecc_metadata(data)) {
155 FATAL("no ecc data\n");
156 }
157
158 printf("%" PRIu64 "\n", data.start);
159 } else {
160 fec_verity_metadata data;
161
162 if (!fh.get_verity_metadata(data)) {
163 FATAL("no verity data\n");
164 }
165
166 printf("%" PRIu64 "\n", data.data_size);
167 }
168
169 return 0;
170 }
171
encode(image & ctx,const std::vector<std::string> & inp_filenames,const std::string & fec_filename)172 static int encode(image& ctx, const std::vector<std::string>& inp_filenames,
173 const std::string& fec_filename)
174 {
175 if (ctx.inplace) {
176 FATAL("invalid parameters: inplace can only used when decoding\n");
177 }
178
179 if (!image_load(inp_filenames, &ctx, false)) {
180 FATAL("failed to read input\n");
181 }
182
183 if (!image_ecc_new(fec_filename, &ctx)) {
184 FATAL("failed to allocate ecc\n");
185 }
186
187 INFO("encoding RS(255, %d) to '%s' for input files:\n", ctx.rs_n,
188 fec_filename.c_str());
189
190 size_t n = 1;
191
192 for (auto fn : inp_filenames) {
193 INFO("\t%zu: '%s'\n", n++, fn.c_str());
194 }
195
196 if (ctx.verbose) {
197 INFO("\traw fec size: %u\n", ctx.fec_size);
198 INFO("\tblocks: %" PRIu64 "\n", ctx.blocks);
199 INFO("\trounds: %" PRIu64 "\n", ctx.rounds);
200 }
201
202 if (!image_process(encode_rs, &ctx)) {
203 FATAL("failed to process input\n");
204 }
205
206 if (!image_ecc_save(&ctx)) {
207 FATAL("failed to write output\n");
208 }
209
210 image_free(&ctx);
211 return 0;
212 }
213
decode(image & ctx,const std::vector<std::string> & inp_filenames,const std::string & fec_filename,std::string & out_filename)214 static int decode(image& ctx, const std::vector<std::string>& inp_filenames,
215 const std::string& fec_filename, std::string& out_filename)
216 {
217 const std::string& inp_filename = inp_filenames.front();
218
219 if (ctx.inplace && ctx.sparse) {
220 FATAL("invalid parameters: inplace cannot be used with sparse "
221 "files\n");
222 }
223
224 if (!image_ecc_load(fec_filename, &ctx) ||
225 !image_load(inp_filenames, &ctx, !out_filename.empty())) {
226 FATAL("failed to read input\n");
227 }
228
229 if (ctx.inplace) {
230 INFO("correcting '%s' using RS(255, %d) from '%s'\n",
231 inp_filename.c_str(), ctx.rs_n, fec_filename.c_str());
232
233 out_filename = inp_filename;
234 } else {
235 INFO("decoding '%s' to '%s' using RS(255, %d) from '%s'\n",
236 inp_filename.c_str(),
237 out_filename.empty() ? out_filename.c_str() : "<none>", ctx.rs_n,
238 fec_filename.c_str());
239 }
240
241 if (ctx.verbose) {
242 INFO("\traw fec size: %u\n", ctx.fec_size);
243 INFO("\tblocks: %" PRIu64 "\n", ctx.blocks);
244 INFO("\trounds: %" PRIu64 "\n", ctx.rounds);
245 }
246
247 if (!image_process(decode_rs, &ctx)) {
248 FATAL("failed to process input\n");
249 }
250
251 if (ctx.rv) {
252 INFO("corrected %" PRIu64 " errors\n", ctx.rv);
253 } else {
254 INFO("no errors found\n");
255 }
256
257 if (!out_filename.empty() && !image_save(out_filename, &ctx)) {
258 FATAL("failed to write output\n");
259 }
260
261 image_free(&ctx);
262 return 0;
263 }
264
main(int argc,char ** argv)265 int main(int argc, char **argv)
266 {
267 std::string fec_filename;
268 std::string out_filename;
269 std::vector<std::string> inp_filenames;
270 int mode = MODE_ENCODE;
271 image ctx;
272
273 image_init(&ctx);
274 ctx.roots = FEC_DEFAULT_ROOTS;
275
276 while (1) {
277 const static struct option long_options[] = {
278 {"help", no_argument, 0, 'h'},
279 {"encode", no_argument, 0, 'e'},
280 {"decode", no_argument, 0, 'd'},
281 {"sparse", no_argument, 0, 'S'},
282 {"roots", required_argument, 0, 'r'},
283 {"inplace", no_argument, 0, 'i'},
284 {"mmap", no_argument, 0, 'm'},
285 {"threads", required_argument, 0, 'j'},
286 {"print-fec-size", required_argument, 0, 's'},
287 {"get-ecc-start", required_argument, 0, 'E'},
288 {"get-verity-start", required_argument, 0, 'V'},
289 {"verbose", no_argument, 0, 'v'},
290 {NULL, 0, 0, 0}
291 };
292 int c = getopt_long(argc, argv, "hedSr:imj:s:E:V:v", long_options, NULL);
293 if (c < 0) {
294 break;
295 }
296
297 switch (c) {
298 case 'h':
299 return usage();
300 case 'S':
301 ctx.sparse = true;
302 break;
303 case 'e':
304 if (mode != MODE_ENCODE) {
305 return usage();
306 }
307 break;
308 case 'd':
309 if (mode != MODE_ENCODE) {
310 return usage();
311 }
312 mode = MODE_DECODE;
313 break;
314 case 'r':
315 ctx.roots = (int)parse_arg(optarg, "roots", FEC_RSM);
316 break;
317 case 'i':
318 ctx.inplace = true;
319 break;
320 case 'm':
321 ctx.mmap = true;
322 break;
323 case 'j':
324 ctx.threads = (int)parse_arg(optarg, "threads", IMAGE_MAX_THREADS);
325 break;
326 case 's':
327 if (mode != MODE_ENCODE) {
328 return usage();
329 }
330 mode = MODE_PRINTSIZE;
331 ctx.inp_size = parse_arg(optarg, "print-fec-size", UINT64_MAX);
332 break;
333 case 'E':
334 if (mode != MODE_ENCODE) {
335 return usage();
336 }
337 mode = MODE_GETECCSTART;
338 inp_filenames.push_back(optarg);
339 break;
340 case 'V':
341 if (mode != MODE_ENCODE) {
342 return usage();
343 }
344 mode = MODE_GETVERITYSTART;
345 inp_filenames.push_back(optarg);
346 break;
347 case 'v':
348 ctx.verbose = true;
349 break;
350 case '?':
351 return usage();
352 default:
353 abort();
354 }
355 }
356
357 argc -= optind;
358 argv += optind;
359
360 assert(ctx.roots > 0 && ctx.roots < FEC_RSM);
361
362 /* check for input / output parameters */
363 if (mode == MODE_ENCODE) {
364 /* allow multiple input files */
365 for (int i = 0; i < (argc - 1); ++i) {
366 inp_filenames.push_back(argv[i]);
367 }
368
369 if (inp_filenames.empty()) {
370 return usage();
371 }
372
373 /* the last one is the output file */
374 fec_filename = argv[argc - 1];
375 } else if (mode == MODE_DECODE) {
376 if (argc < 2 || argc > 3) {
377 return usage();
378 } else if (argc == 3) {
379 if (ctx.inplace) {
380 return usage();
381 }
382 out_filename = argv[2];
383 }
384
385 inp_filenames.push_back(argv[0]);
386 fec_filename = argv[1];
387 }
388
389 switch (mode) {
390 case MODE_PRINTSIZE:
391 return print_size(ctx);
392 case MODE_GETECCSTART:
393 case MODE_GETVERITYSTART:
394 return get_start(mode, inp_filenames.front());
395 case MODE_ENCODE:
396 return encode(ctx, inp_filenames, fec_filename);
397 case MODE_DECODE:
398 return decode(ctx, inp_filenames, fec_filename, out_filename);
399 default:
400 abort();
401 }
402
403 return 1;
404 }
405