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