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fada2fcd TK |
1 | #include <stdio.h> |
2 | #include <stdlib.h> | |
3 | #include <string.h> | |
4 | #include <limits.h> | |
5 | #include <errno.h> | |
6 | #include <assert.h> | |
a1554f65 SB |
7 | #include <sys/types.h> |
8 | #include <sys/stat.h> | |
9 | #include <fcntl.h> | |
10 | #include <unistd.h> | |
fada2fcd | 11 | |
634bd210 RP |
12 | #include "strntol.h" |
13 | #include "pattern.h" | |
fada2fcd | 14 | #include "../minmax.h" |
a328eb9a | 15 | #include "../oslib/strcasestr.h" |
b29c71c4 | 16 | #include "../oslib/strndup.h" |
634bd210 | 17 | |
a1554f65 SB |
18 | /** |
19 | * parse_file() - parses binary file to fill buffer | |
20 | * @beg - string input, extract filename from this | |
21 | * @out - output buffer where parsed number should be put | |
22 | * @out_len - length of the output buffer | |
23 | * @filled - pointer where number of bytes successfully | |
24 | * parsed will be put | |
25 | * | |
26 | * Returns the end pointer where parsing has been stopped. | |
27 | * In case of parsing error or lack of bytes in output buffer | |
28 | * NULL will be returned. | |
29 | */ | |
30 | static const char *parse_file(const char *beg, char *out, | |
31 | unsigned int out_len, | |
32 | unsigned int *filled) | |
33 | { | |
34 | const char *end; | |
35 | char *file; | |
36 | int fd; | |
37 | ssize_t count; | |
38 | ||
39 | if (!out_len) | |
40 | goto err_out; | |
41 | ||
42 | assert(*beg == '\''); | |
43 | beg++; | |
44 | end = strchr(beg, '\''); | |
45 | if (!end) | |
46 | goto err_out; | |
47 | ||
48 | file = strndup(beg, end - beg); | |
49 | if (file == NULL) | |
50 | goto err_out; | |
51 | ||
52 | fd = open(file, O_RDONLY); | |
53 | if (fd < 0) | |
54 | goto err_free_out; | |
55 | ||
56 | count = read(fd, out, out_len); | |
57 | if (count == -1) | |
58 | goto err_free_close_out; | |
59 | ||
60 | *filled = count; | |
61 | close(fd); | |
62 | free(file); | |
63 | ||
64 | /* Catch up quote */ | |
65 | return end + 1; | |
66 | ||
67 | err_free_close_out: | |
68 | close(fd); | |
69 | err_free_out: | |
70 | free(file); | |
71 | err_out: | |
72 | return NULL; | |
73 | ||
74 | } | |
75 | ||
634bd210 RP |
76 | /** |
77 | * parse_string() - parses string in double quotes, like "abc" | |
78 | * @beg - string input | |
79 | * @out - output buffer where parsed number should be put | |
80 | * @out_len - length of the output buffer | |
81 | * @filled - pointer where number of bytes successfully | |
82 | * parsed will be put | |
83 | * | |
84 | * Returns the end pointer where parsing has been stopped. | |
85 | * In case of parsing error or lack of bytes in output buffer | |
86 | * NULL will be returned. | |
87 | */ | |
88 | static const char *parse_string(const char *beg, char *out, | |
89 | unsigned int out_len, | |
90 | unsigned int *filled) | |
91 | { | |
92 | const char *end; | |
93 | ||
94 | if (!out_len) | |
95 | return NULL; | |
96 | ||
97 | assert(*beg == '"'); | |
98 | beg++; | |
99 | end = strchr(beg, '"'); | |
100 | if (!end) | |
101 | return NULL; | |
102 | if (end - beg > out_len) | |
103 | return NULL; | |
104 | ||
105 | memcpy(out, beg, end - beg); | |
106 | *filled = end - beg; | |
107 | ||
108 | /* Catch up quote */ | |
109 | return end + 1; | |
110 | } | |
111 | ||
112 | /** | |
113 | * parse_number() - parses numbers | |
114 | * @beg - string input | |
115 | * @out - output buffer where parsed number should be put | |
116 | * @out_len - length of the output buffer | |
117 | * @filled - pointer where number of bytes successfully | |
118 | * parsed will be put | |
119 | * | |
120 | * Supports decimals in the range [INT_MIN, INT_MAX] and | |
121 | * hexidecimals of any size, which should be started with | |
122 | * prefix 0x or 0X. | |
123 | * | |
124 | * Returns the end pointer where parsing has been stopped. | |
125 | * In case of parsing error or lack of bytes in output buffer | |
126 | * NULL will be returned. | |
127 | */ | |
128 | static const char *parse_number(const char *beg, char *out, | |
129 | unsigned int out_len, | |
130 | unsigned int *filled) | |
131 | { | |
132 | const char *end; | |
133 | unsigned int val; | |
134 | long lval; | |
135 | int num, i; | |
136 | ||
137 | if (!out_len) | |
138 | return NULL; | |
139 | ||
140 | num = 0; | |
141 | sscanf(beg, "0%*[xX]%*[0-9a-fA-F]%n", &num); | |
142 | if (num == 0) { | |
143 | /* Here we are trying to parse decimal */ | |
144 | ||
145 | char *_end; | |
146 | ||
147 | /* Looking ahead */ | |
148 | _end = strcasestr(beg, "0x"); | |
149 | if (_end) | |
150 | num = _end - beg; | |
151 | if (num) | |
152 | lval = strntol(beg, num, &_end, 10); | |
153 | else | |
154 | lval = strtol(beg, &_end, 10); | |
155 | if (beg == _end || lval > INT_MAX || lval < INT_MIN) | |
156 | return NULL; | |
157 | end = _end; | |
158 | i = 0; | |
159 | if (!lval) { | |
160 | num = 0; | |
161 | out[i] = 0x00; | |
162 | i = 1; | |
163 | } else { | |
164 | val = (unsigned int)lval; | |
165 | for (; val && out_len; out_len--, i++, val >>= 8) | |
166 | out[i] = val & 0xff; | |
167 | if (val) | |
168 | return NULL; | |
169 | } | |
170 | } else { | |
171 | assert(num > 2); | |
172 | ||
173 | /* Catch up 0x prefix */ | |
174 | num -= 2; | |
175 | beg += 2; | |
176 | ||
177 | /* Look back, handle this combined string: 0xff0x14 */ | |
178 | if (beg[num] && !strncasecmp(&beg[num - 1], "0x", 2)) | |
179 | num--; | |
180 | ||
181 | end = beg + num; | |
182 | ||
183 | for (i = 0; num && out_len; | |
184 | out_len--, i++, num -= 2, beg += 2) { | |
185 | const char *fmt; | |
186 | ||
187 | fmt = (num & 1 ? "%1hhx" : "%2hhx"); | |
188 | sscanf(beg, fmt, &out[i]); | |
189 | if (num & 1) { | |
190 | num++; | |
191 | beg--; | |
192 | } | |
193 | } | |
194 | if (num) | |
195 | return NULL; | |
196 | } | |
197 | ||
198 | *filled = i; | |
199 | return end; | |
200 | ||
201 | } | |
202 | ||
203 | /** | |
204 | * parse_format() - parses formats, like %o, etc | |
205 | * @in - string input | |
206 | * @out - output buffer where space for format should be reserved | |
207 | * @parsed - number of bytes which were already parsed so far | |
208 | * @out_len - length of the output buffer | |
209 | * @fmt_desc - format descritor array, what we expect to find | |
210 | * @fmt_desc_sz - size of the format descritor array | |
211 | * @fmt - format array, the output | |
212 | * @fmt_sz - size of format array | |
213 | * | |
214 | * This function tries to find formats, e.g.: | |
215 | * %o - offset of the block | |
216 | * | |
217 | * In case of successfull parsing it fills the format param | |
218 | * with proper offset and the size of the expected value, which | |
219 | * should be pasted into buffer using the format 'func' callback. | |
220 | * | |
221 | * Returns the end pointer where parsing has been stopped. | |
222 | * In case of parsing error or lack of bytes in output buffer | |
223 | * NULL will be returned. | |
224 | */ | |
225 | static const char *parse_format(const char *in, char *out, unsigned int parsed, | |
226 | unsigned int out_len, unsigned int *filled, | |
227 | const struct pattern_fmt_desc *fmt_desc, | |
228 | unsigned int fmt_desc_sz, | |
229 | struct pattern_fmt *fmt, unsigned int fmt_sz) | |
230 | { | |
231 | int i; | |
232 | struct pattern_fmt *f = NULL; | |
233 | unsigned int len = 0; | |
234 | ||
235 | if (!out_len || !fmt_desc || !fmt_desc_sz || !fmt || !fmt_sz) | |
236 | return NULL; | |
237 | ||
238 | assert(*in == '%'); | |
239 | ||
240 | for (i = 0; i < fmt_desc_sz; i++) { | |
241 | const struct pattern_fmt_desc *desc; | |
242 | ||
243 | desc = &fmt_desc[i]; | |
244 | len = strlen(desc->fmt); | |
245 | if (0 == strncmp(in, desc->fmt, len)) { | |
246 | fmt->desc = desc; | |
247 | fmt->off = parsed; | |
248 | f = fmt; | |
249 | break; | |
250 | } | |
251 | } | |
252 | ||
253 | if (!f) | |
254 | return NULL; | |
255 | if (f->desc->len > out_len) | |
256 | return NULL; | |
257 | ||
258 | memset(out, '\0', f->desc->len); | |
259 | *filled = f->desc->len; | |
260 | ||
261 | return in + len; | |
262 | } | |
263 | ||
264 | /** | |
265 | * parse_and_fill_pattern() - Parses combined input, which consists of strings, | |
266 | * numbers and pattern formats. | |
267 | * @in - string input | |
268 | * @in_len - size of the input string | |
269 | * @out - output buffer where parsed result will be put | |
270 | * @out_len - lengths of the output buffer | |
271 | * @fmt_desc - array of pattern format descriptors [input] | |
272 | * @fmt_desc_sz - size of the format descriptor array | |
273 | * @fmt - array of pattern formats [output] | |
274 | * @fmt_sz - pointer where the size of pattern formats array stored [input], | |
275 | * after successfull parsing this pointer will contain the number | |
276 | * of parsed formats if any [output]. | |
277 | * | |
278 | * strings: | |
279 | * bytes sequence in double quotes, e.g. "123". | |
280 | * NOTE: there is no way to escape quote, so "123\"abc" does not work. | |
281 | * | |
282 | * numbers: | |
283 | * hexidecimal - sequence of hex bytes starting from 0x or 0X prefix, | |
284 | * e.g. 0xff12ceff1100ff | |
285 | * decimal - decimal number in range [INT_MIN, INT_MAX] | |
286 | * | |
287 | * formats: | |
288 | * %o - offset of block, reserved 8 bytes. | |
289 | * | |
290 | * Explicit examples of combined string: | |
291 | * #1 #2 #3 #4 | |
292 | * in="abcd" in=-1024 in=66 in=0xFF0X1 | |
293 | * out=61 62 63 64 out=00 fc ff ff out=42 out=ff 01 | |
294 | * | |
295 | * #5 #6 | |
296 | * in=%o in="123"0xFFeeCC | |
297 | * out=00 00 00 00 00 00 00 00 out=31 32 33 ff ec cc | |
298 | * | |
299 | * #7 | |
300 | * in=-100xab"1"%o"2" | |
301 | * out=f6 ff ff ff ab 31 00 00 00 00 00 00 00 00 32 | |
302 | * | |
303 | * #9 | |
304 | * in=%o0xdeadbeef%o | |
305 | * out=00 00 00 00 00 00 00 00 de ad be ef 00 00 00 00 00 00 00 00 | |
306 | * | |
307 | * #10 | |
308 | * in=0xfefefefefefefefefefefefefefefefefefefefefe | |
309 | * out=fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe | |
310 | * | |
311 | * Returns number of bytes filled or err < 0 in case of failure. | |
312 | */ | |
313 | int parse_and_fill_pattern(const char *in, unsigned int in_len, | |
314 | char *out, unsigned int out_len, | |
315 | const struct pattern_fmt_desc *fmt_desc, | |
316 | unsigned int fmt_desc_sz, | |
317 | struct pattern_fmt *fmt, | |
318 | unsigned int *fmt_sz_out) | |
319 | { | |
320 | const char *beg, *end, *out_beg = out; | |
321 | unsigned int total = 0, fmt_rem = 0; | |
322 | ||
323 | if (!in || !in_len || !out || !out_len) | |
324 | return -EINVAL; | |
325 | if (fmt_sz_out) | |
326 | fmt_rem = *fmt_sz_out; | |
327 | ||
328 | beg = in; | |
329 | do { | |
330 | unsigned int filled; | |
331 | int parsed_fmt; | |
332 | ||
333 | filled = 0; | |
334 | parsed_fmt = 0; | |
335 | ||
336 | switch (*beg) { | |
a1554f65 SB |
337 | case '\'': |
338 | end = parse_file(beg, out, out_len, &filled); | |
339 | break; | |
634bd210 RP |
340 | case '"': |
341 | end = parse_string(beg, out, out_len, &filled); | |
342 | break; | |
343 | case '%': | |
344 | end = parse_format(beg, out, out - out_beg, out_len, | |
345 | &filled, fmt_desc, fmt_desc_sz, | |
346 | fmt, fmt_rem); | |
347 | parsed_fmt = 1; | |
348 | break; | |
349 | default: | |
350 | end = parse_number(beg, out, out_len, &filled); | |
351 | break; | |
352 | } | |
353 | ||
354 | if (!end) | |
355 | return -EINVAL; | |
356 | ||
357 | if (parsed_fmt) { | |
358 | assert(fmt_rem); | |
359 | fmt_rem--; | |
360 | fmt++; | |
361 | } | |
362 | ||
363 | assert(end - beg <= in_len); | |
364 | in_len -= end - beg; | |
365 | beg = end; | |
366 | ||
367 | assert(filled); | |
368 | assert(filled <= out_len); | |
369 | out_len -= filled; | |
370 | out += filled; | |
371 | total += filled; | |
372 | ||
373 | } while (in_len); | |
374 | ||
375 | if (fmt_sz_out) | |
376 | *fmt_sz_out -= fmt_rem; | |
377 | return total; | |
378 | } | |
379 | ||
380 | /** | |
381 | * dup_pattern() - Duplicates part of the pattern all over the buffer. | |
382 | * | |
383 | * Returns 0 in case of success or errno < 0 in case of failure. | |
384 | */ | |
385 | static int dup_pattern(char *out, unsigned int out_len, unsigned int pattern_len) | |
386 | { | |
387 | unsigned int left, len, off; | |
388 | ||
389 | if (out_len <= pattern_len) | |
390 | /* Normal case */ | |
391 | return 0; | |
392 | ||
393 | off = pattern_len; | |
394 | left = (out_len - off); | |
395 | len = min(left, off); | |
396 | ||
397 | /* Duplicate leftover */ | |
398 | while (left) { | |
399 | memcpy(out + off, out, len); | |
400 | left -= len; | |
401 | off <<= 1; | |
402 | len = min(left, off); | |
403 | } | |
404 | ||
405 | return 0; | |
406 | } | |
407 | ||
408 | /** | |
409 | * cpy_pattern() - Copies pattern to the buffer. | |
410 | * | |
411 | * Function copies pattern along the whole buffer. | |
412 | * | |
413 | * Returns 0 in case of success or errno < 0 in case of failure. | |
414 | */ | |
415 | int cpy_pattern(const char *pattern, unsigned int pattern_len, | |
416 | char *out, unsigned int out_len) | |
417 | { | |
418 | unsigned int len; | |
419 | ||
420 | if (!pattern || !pattern_len || !out || !out_len) | |
421 | return -EINVAL; | |
422 | ||
423 | /* Copy pattern */ | |
424 | len = min(pattern_len, out_len); | |
425 | memcpy(out, pattern, len); | |
426 | ||
427 | /* Spread filled chunk all over the buffer */ | |
428 | return dup_pattern(out, out_len, pattern_len); | |
429 | } | |
430 | ||
431 | /** | |
432 | * cmp_pattern() - Compares pattern and buffer. | |
433 | * | |
434 | * For the sake of performance this function avoids any loops. | |
435 | * Firstly it tries to compare the buffer itself, checking that | |
436 | * buffer consists of repeating patterns along the buffer size. | |
437 | * | |
438 | * If the difference is not found then the function tries to compare | |
439 | * buffer and pattern. | |
440 | * | |
441 | * Returns 0 in case of success or errno < 0 in case of failure. | |
442 | */ | |
443 | int cmp_pattern(const char *pattern, unsigned int pattern_size, | |
444 | unsigned int off, const char *buf, unsigned int len) | |
445 | { | |
446 | int rc; | |
447 | unsigned int size; | |
448 | ||
449 | /* Find the difference in buffer */ | |
450 | if (len > pattern_size) { | |
451 | rc = memcmp(buf, buf + pattern_size, len - pattern_size); | |
452 | if (rc) | |
453 | return -EILSEQ; | |
454 | } | |
455 | /* Compare second part of the pattern with buffer */ | |
456 | if (off) { | |
457 | size = min(len, pattern_size - off); | |
458 | rc = memcmp(buf, pattern + off, size); | |
459 | if (rc) | |
460 | return -EILSEQ; | |
461 | buf += size; | |
462 | len -= size; | |
463 | } | |
464 | /* Compare first part of the pattern or the whole pattern | |
465 | * with buffer */ | |
466 | if (len) { | |
467 | size = min(len, (off ? off : pattern_size)); | |
468 | rc = memcmp(buf, pattern, size); | |
469 | if (rc) | |
470 | return -EILSEQ; | |
471 | } | |
472 | ||
473 | return 0; | |
474 | } | |
475 | ||
476 | /** | |
477 | * paste_format_inplace() - Pastes parsed formats to the pattern. | |
478 | * | |
479 | * This function pastes formats to the pattern. If @fmt_sz is 0 | |
480 | * function does nothing and pattern buffer is left untouched. | |
481 | * | |
482 | * Returns 0 in case of success or errno < 0 in case of failure. | |
483 | */ | |
484 | int paste_format_inplace(char *pattern, unsigned int pattern_len, | |
485 | struct pattern_fmt *fmt, unsigned int fmt_sz, | |
486 | void *priv) | |
487 | { | |
488 | int i, rc; | |
489 | unsigned int len; | |
490 | ||
491 | if (!pattern || !pattern_len || !fmt) | |
492 | return -EINVAL; | |
493 | ||
494 | /* Paste formats for first pattern chunk */ | |
495 | for (i = 0; i < fmt_sz; i++) { | |
496 | struct pattern_fmt *f; | |
497 | ||
498 | f = &fmt[i]; | |
499 | if (pattern_len <= f->off) | |
500 | break; | |
501 | len = min(pattern_len - f->off, f->desc->len); | |
502 | rc = f->desc->paste(pattern + f->off, len, priv); | |
503 | if (rc) | |
504 | return rc; | |
505 | } | |
506 | ||
507 | return 0; | |
508 | } | |
509 | ||
510 | /** | |
511 | * paste_format() - Pastes parsed formats to the buffer. | |
512 | * | |
513 | * This function copies pattern to the buffer, pastes format | |
514 | * into it and then duplicates pattern all over the buffer size. | |
515 | * | |
516 | * Returns 0 in case of success or errno < 0 in case of failure. | |
517 | */ | |
518 | int paste_format(const char *pattern, unsigned int pattern_len, | |
519 | struct pattern_fmt *fmt, unsigned int fmt_sz, | |
520 | char *out, unsigned int out_len, void *priv) | |
521 | { | |
522 | int rc; | |
523 | unsigned int len; | |
524 | ||
525 | if (!pattern || !pattern_len || !out || !out_len) | |
526 | return -EINVAL; | |
527 | ||
528 | /* Copy pattern */ | |
529 | len = min(pattern_len, out_len); | |
530 | memcpy(out, pattern, len); | |
531 | ||
532 | rc = paste_format_inplace(out, len, fmt, fmt_sz, priv); | |
533 | if (rc) | |
534 | return rc; | |
535 | ||
536 | /* Spread filled chunk all over the buffer */ | |
537 | return dup_pattern(out, out_len, pattern_len); | |
538 | } |