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Commit | Line | Data |
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95b98ba9 | 1 | |
625fcfe9 | 2 | #include "yaml_private.h" |
6eb1ded4 | 3 | |
625fcfe9 KS |
4 | /* |
5 | * Declarations. | |
6 | */ | |
7 | ||
8 | static int | |
9 | yaml_parser_set_reader_error(yaml_parser_t *parser, const char *problem, | |
10 | size_t offset, int value); | |
6eb1ded4 | 11 | |
625fcfe9 KS |
12 | static int |
13 | yaml_parser_update_raw_buffer(yaml_parser_t *parser); | |
14 | ||
15 | static int | |
16 | yaml_parser_determine_encoding(yaml_parser_t *parser); | |
17 | ||
18 | YAML_DECLARE(int) | |
19 | yaml_parser_update_buffer(yaml_parser_t *parser, size_t length); | |
6eb1ded4 | 20 | |
6eb1ded4 | 21 | /* |
3d790dfd | 22 | * Set the reader error and return 0. |
6eb1ded4 KS |
23 | */ |
24 | ||
f642fd11 | 25 | static int |
2fa16060 KS |
26 | yaml_parser_set_reader_error(yaml_parser_t *parser, const char *problem, |
27 | size_t offset, int value) | |
3d790dfd KS |
28 | { |
29 | parser->error = YAML_READER_ERROR; | |
30 | parser->problem = problem; | |
2fa16060 KS |
31 | parser->problem_offset = offset; |
32 | parser->problem_value = value; | |
6eb1ded4 | 33 | |
3d790dfd KS |
34 | return 0; |
35 | } | |
6eb1ded4 | 36 | |
f642fd11 | 37 | /* |
625fcfe9 | 38 | * Byte order marks. |
f642fd11 KS |
39 | */ |
40 | ||
625fcfe9 KS |
41 | #define BOM_UTF8 "\xef\xbb\xbf" |
42 | #define BOM_UTF16LE "\xff\xfe" | |
43 | #define BOM_UTF16BE "\xfe\xff" | |
f642fd11 KS |
44 | |
45 | /* | |
46 | * Determine the input stream encoding by checking the BOM symbol. If no BOM is | |
47 | * found, the UTF-8 encoding is assumed. Return 1 on success, 0 on failure. | |
48 | */ | |
49 | ||
f642fd11 KS |
50 | static int |
51 | yaml_parser_determine_encoding(yaml_parser_t *parser) | |
52 | { | |
53 | /* Ensure that we had enough bytes in the raw buffer. */ | |
54 | ||
625fcfe9 KS |
55 | while (!parser->eof |
56 | && parser->raw_buffer.last - parser->raw_buffer.pointer < 3) { | |
f642fd11 KS |
57 | if (!yaml_parser_update_raw_buffer(parser)) { |
58 | return 0; | |
59 | } | |
60 | } | |
61 | ||
62 | /* Determine the encoding. */ | |
63 | ||
625fcfe9 KS |
64 | if (parser->raw_buffer.last - parser->raw_buffer.pointer >= 2 |
65 | && !memcmp(parser->raw_buffer.pointer, BOM_UTF16LE, 2)) { | |
f642fd11 | 66 | parser->encoding = YAML_UTF16LE_ENCODING; |
625fcfe9 | 67 | parser->raw_buffer.pointer += 2; |
f642fd11 KS |
68 | parser->offset += 2; |
69 | } | |
625fcfe9 KS |
70 | else if (parser->raw_buffer.last - parser->raw_buffer.pointer >= 2 |
71 | && !memcmp(parser->raw_buffer.pointer, BOM_UTF16BE, 2)) { | |
f642fd11 | 72 | parser->encoding = YAML_UTF16BE_ENCODING; |
625fcfe9 | 73 | parser->raw_buffer.pointer += 2; |
f642fd11 KS |
74 | parser->offset += 2; |
75 | } | |
625fcfe9 KS |
76 | else if (parser->raw_buffer.last - parser->raw_buffer.pointer >= 3 |
77 | && !memcmp(parser->raw_buffer.pointer, BOM_UTF8, 3)) { | |
f642fd11 | 78 | parser->encoding = YAML_UTF8_ENCODING; |
625fcfe9 | 79 | parser->raw_buffer.pointer += 3; |
f642fd11 KS |
80 | parser->offset += 3; |
81 | } | |
82 | else { | |
83 | parser->encoding = YAML_UTF8_ENCODING; | |
84 | } | |
85 | ||
86 | return 1; | |
87 | } | |
95b98ba9 KS |
88 | |
89 | /* | |
625fcfe9 KS |
90 | * Update the raw buffer. |
91 | */ | |
92 | ||
93 | static int | |
94 | yaml_parser_update_raw_buffer(yaml_parser_t *parser) | |
95 | { | |
96 | size_t size_read = 0; | |
97 | ||
98 | /* Return if the raw buffer is full. */ | |
99 | ||
100 | if (parser->raw_buffer.start == parser->raw_buffer.pointer | |
101 | && parser->raw_buffer.last == parser->raw_buffer.end) | |
102 | return 1; | |
103 | ||
104 | /* Return on EOF. */ | |
105 | ||
106 | if (parser->eof) return 1; | |
107 | ||
108 | /* Move the remaining bytes in the raw buffer to the beginning. */ | |
109 | ||
110 | if (parser->raw_buffer.start < parser->raw_buffer.pointer | |
111 | && parser->raw_buffer.pointer < parser->raw_buffer.last) { | |
112 | memmove(parser->raw_buffer.start, parser->raw_buffer.pointer, | |
113 | parser->raw_buffer.last - parser->raw_buffer.pointer); | |
114 | } | |
115 | parser->raw_buffer.last -= | |
116 | parser->raw_buffer.pointer - parser->raw_buffer.start; | |
117 | parser->raw_buffer.pointer = parser->raw_buffer.start; | |
118 | ||
119 | /* Call the read handler to fill the buffer. */ | |
120 | ||
121 | if (!parser->read_handler(parser->read_handler_data, parser->raw_buffer.last, | |
122 | parser->raw_buffer.end - parser->raw_buffer.last, &size_read)) { | |
c70abc4d | 123 | return yaml_parser_set_reader_error(parser, "input error", |
625fcfe9 KS |
124 | parser->offset, -1); |
125 | } | |
126 | parser->raw_buffer.last += size_read; | |
127 | if (!size_read) { | |
128 | parser->eof = 1; | |
129 | } | |
130 | ||
131 | return 1; | |
132 | } | |
133 | ||
134 | /* | |
135 | * Ensure that the buffer contains at least `length` characters. | |
95b98ba9 | 136 | * Return 1 on success, 0 on failure. |
6eb1ded4 KS |
137 | * |
138 | * The length is supposed to be significantly less that the buffer size. | |
95b98ba9 KS |
139 | */ |
140 | ||
f642fd11 | 141 | YAML_DECLARE(int) |
6eb1ded4 | 142 | yaml_parser_update_buffer(yaml_parser_t *parser, size_t length) |
95b98ba9 | 143 | { |
1893dabd KS |
144 | int first = 1; |
145 | ||
625fcfe9 KS |
146 | assert(parser->read_handler); /* Read handler must be set. */ |
147 | ||
2fa16060 | 148 | /* If the EOF flag is set and the raw buffer is empty, do nothing. */ |
95b98ba9 | 149 | |
625fcfe9 | 150 | if (parser->eof && parser->raw_buffer.pointer == parser->raw_buffer.last) |
95b98ba9 KS |
151 | return 1; |
152 | ||
6eb1ded4 KS |
153 | /* Return if the buffer contains enough characters. */ |
154 | ||
155 | if (parser->unread >= length) | |
156 | return 1; | |
157 | ||
158 | /* Determine the input encoding if it is not known yet. */ | |
95b98ba9 | 159 | |
6eb1ded4 KS |
160 | if (!parser->encoding) { |
161 | if (!yaml_parser_determine_encoding(parser)) | |
95b98ba9 | 162 | return 0; |
95b98ba9 KS |
163 | } |
164 | ||
6eb1ded4 KS |
165 | /* Move the unread characters to the beginning of the buffer. */ |
166 | ||
625fcfe9 KS |
167 | if (parser->buffer.start < parser->buffer.pointer |
168 | && parser->buffer.pointer < parser->buffer.last) { | |
169 | size_t size = parser->buffer.last - parser->buffer.pointer; | |
170 | memmove(parser->buffer.start, parser->buffer.pointer, size); | |
171 | parser->buffer.pointer = parser->buffer.start; | |
172 | parser->buffer.last = parser->buffer.start + size; | |
6eb1ded4 | 173 | } |
625fcfe9 KS |
174 | else if (parser->buffer.pointer == parser->buffer.last) { |
175 | parser->buffer.pointer = parser->buffer.start; | |
176 | parser->buffer.last = parser->buffer.start; | |
6eb1ded4 KS |
177 | } |
178 | ||
179 | /* Fill the buffer until it has enough characters. */ | |
180 | ||
181 | while (parser->unread < length) | |
182 | { | |
1893dabd | 183 | /* Fill the raw buffer if necessary. */ |
6eb1ded4 | 184 | |
1893dabd KS |
185 | if (!first || parser->raw_buffer.pointer == parser->raw_buffer.last) { |
186 | if (!yaml_parser_update_raw_buffer(parser)) return 0; | |
187 | } | |
188 | first = 0; | |
6eb1ded4 KS |
189 | |
190 | /* Decode the raw buffer. */ | |
191 | ||
625fcfe9 | 192 | while (parser->raw_buffer.pointer != parser->raw_buffer.last) |
6eb1ded4 | 193 | { |
54815ffd | 194 | unsigned int value = 0, value2 = 0; |
6eb1ded4 | 195 | int incomplete = 0; |
2fa16060 | 196 | unsigned char octet; |
54815ffd | 197 | unsigned int width = 0; |
0174ed6e KS |
198 | int low, high; |
199 | size_t k; | |
200 | size_t raw_unread = parser->raw_buffer.last - parser->raw_buffer.pointer; | |
6eb1ded4 KS |
201 | |
202 | /* Decode the next character. */ | |
203 | ||
204 | switch (parser->encoding) | |
205 | { | |
206 | case YAML_UTF8_ENCODING: | |
207 | ||
3d790dfd KS |
208 | /* |
209 | * Decode a UTF-8 character. Check RFC 3629 | |
210 | * (http://www.ietf.org/rfc/rfc3629.txt) for more details. | |
211 | * | |
212 | * The following table (taken from the RFC) is used for | |
213 | * decoding. | |
214 | * | |
215 | * Char. number range | UTF-8 octet sequence | |
216 | * (hexadecimal) | (binary) | |
217 | * --------------------+------------------------------------ | |
218 | * 0000 0000-0000 007F | 0xxxxxxx | |
219 | * 0000 0080-0000 07FF | 110xxxxx 10xxxxxx | |
220 | * 0000 0800-0000 FFFF | 1110xxxx 10xxxxxx 10xxxxxx | |
221 | * 0001 0000-0010 FFFF | 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx | |
222 | * | |
223 | * Additionally, the characters in the range 0xD800-0xDFFF | |
224 | * are prohibited as they are reserved for use with UTF-16 | |
225 | * surrogate pairs. | |
226 | */ | |
227 | ||
228 | /* Determine the length of the UTF-8 sequence. */ | |
229 | ||
625fcfe9 | 230 | octet = parser->raw_buffer.pointer[0]; |
2fa16060 KS |
231 | width = (octet & 0x80) == 0x00 ? 1 : |
232 | (octet & 0xE0) == 0xC0 ? 2 : | |
233 | (octet & 0xF0) == 0xE0 ? 3 : | |
234 | (octet & 0xF8) == 0xF0 ? 4 : 0; | |
3d790dfd KS |
235 | |
236 | /* Check if the leading octet is valid. */ | |
237 | ||
2fa16060 | 238 | if (!width) |
3d790dfd | 239 | return yaml_parser_set_reader_error(parser, |
c70abc4d | 240 | "invalid leading UTF-8 octet", |
2fa16060 | 241 | parser->offset, octet); |
6eb1ded4 KS |
242 | |
243 | /* Check if the raw buffer contains an incomplete character. */ | |
244 | ||
625fcfe9 | 245 | if (width > raw_unread) { |
6eb1ded4 | 246 | if (parser->eof) { |
3d790dfd | 247 | return yaml_parser_set_reader_error(parser, |
c70abc4d | 248 | "incomplete UTF-8 octet sequence", |
2fa16060 | 249 | parser->offset, -1); |
6eb1ded4 KS |
250 | } |
251 | incomplete = 1; | |
3d790dfd | 252 | break; |
6eb1ded4 KS |
253 | } |
254 | ||
3d790dfd | 255 | /* Decode the leading octet. */ |
6eb1ded4 | 256 | |
2fa16060 KS |
257 | value = (octet & 0x80) == 0x00 ? octet & 0x7F : |
258 | (octet & 0xE0) == 0xC0 ? octet & 0x1F : | |
259 | (octet & 0xF0) == 0xE0 ? octet & 0x0F : | |
260 | (octet & 0xF8) == 0xF0 ? octet & 0x07 : 0; | |
3d790dfd KS |
261 | |
262 | /* Check and decode the trailing octets. */ | |
263 | ||
2fa16060 | 264 | for (k = 1; k < width; k ++) |
3d790dfd | 265 | { |
625fcfe9 | 266 | octet = parser->raw_buffer.pointer[k]; |
3d790dfd KS |
267 | |
268 | /* Check if the octet is valid. */ | |
269 | ||
2fa16060 | 270 | if ((octet & 0xC0) != 0x80) |
3d790dfd | 271 | return yaml_parser_set_reader_error(parser, |
c70abc4d | 272 | "invalid trailing UTF-8 octet", |
2fa16060 | 273 | parser->offset+k, octet); |
3d790dfd KS |
274 | |
275 | /* Decode the octet. */ | |
276 | ||
2fa16060 | 277 | value = (value << 6) + (octet & 0x3F); |
6eb1ded4 KS |
278 | } |
279 | ||
3d790dfd KS |
280 | /* Check the length of the sequence against the value. */ |
281 | ||
2fa16060 KS |
282 | if (!((width == 1) || |
283 | (width == 2 && value >= 0x80) || | |
284 | (width == 3 && value >= 0x800) || | |
285 | (width == 4 && value >= 0x10000))) | |
3d790dfd | 286 | return yaml_parser_set_reader_error(parser, |
c70abc4d | 287 | "invalid length of a UTF-8 sequence", |
2fa16060 | 288 | parser->offset, -1); |
3d790dfd KS |
289 | |
290 | /* Check the range of the value. */ | |
291 | ||
292 | if ((value >= 0xD800 && value <= 0xDFFF) || value > 0x10FFFF) | |
293 | return yaml_parser_set_reader_error(parser, | |
c70abc4d | 294 | "invalid Unicode character", |
2fa16060 | 295 | parser->offset, value); |
3d790dfd | 296 | |
6eb1ded4 KS |
297 | break; |
298 | ||
299 | case YAML_UTF16LE_ENCODING: | |
3d790dfd | 300 | case YAML_UTF16BE_ENCODING: |
6eb1ded4 | 301 | |
3d790dfd KS |
302 | low = (parser->encoding == YAML_UTF16LE_ENCODING ? 0 : 1); |
303 | high = (parser->encoding == YAML_UTF16LE_ENCODING ? 1 : 0); | |
304 | ||
305 | /* | |
306 | * The UTF-16 encoding is not as simple as one might | |
307 | * naively think. Check RFC 2781 | |
308 | * (http://www.ietf.org/rfc/rfc2781.txt). | |
309 | * | |
310 | * Normally, two subsequent bytes describe a Unicode | |
311 | * character. However a special technique (called a | |
312 | * surrogate pair) is used for specifying character | |
313 | * values larger than 0xFFFF. | |
314 | * | |
315 | * A surrogate pair consists of two pseudo-characters: | |
316 | * high surrogate area (0xD800-0xDBFF) | |
317 | * low surrogate area (0xDC00-0xDFFF) | |
318 | * | |
319 | * The following formulas are used for decoding | |
320 | * and encoding characters using surrogate pairs: | |
321 | * | |
322 | * U = U' + 0x10000 (0x01 00 00 <= U <= 0x10 FF FF) | |
323 | * U' = yyyyyyyyyyxxxxxxxxxx (0 <= U' <= 0x0F FF FF) | |
324 | * W1 = 110110yyyyyyyyyy | |
325 | * W2 = 110111xxxxxxxxxx | |
326 | * | |
327 | * where U is the character value, W1 is the high surrogate | |
328 | * area, W2 is the low surrogate area. | |
329 | */ | |
330 | ||
331 | /* Check for incomplete UTF-16 character. */ | |
6eb1ded4 | 332 | |
625fcfe9 | 333 | if (raw_unread < 2) { |
6eb1ded4 | 334 | if (parser->eof) { |
3d790dfd | 335 | return yaml_parser_set_reader_error(parser, |
c70abc4d | 336 | "incomplete UTF-16 character", |
2fa16060 | 337 | parser->offset, -1); |
6eb1ded4 KS |
338 | } |
339 | incomplete = 1; | |
3d790dfd | 340 | break; |
6eb1ded4 KS |
341 | } |
342 | ||
3d790dfd | 343 | /* Get the character. */ |
6eb1ded4 | 344 | |
625fcfe9 KS |
345 | value = parser->raw_buffer.pointer[low] |
346 | + (parser->raw_buffer.pointer[high] << 8); | |
6eb1ded4 | 347 | |
3d790dfd | 348 | /* Check for unexpected low surrogate area. */ |
6eb1ded4 | 349 | |
3d790dfd KS |
350 | if ((value & 0xFC00) == 0xDC00) |
351 | return yaml_parser_set_reader_error(parser, | |
c70abc4d | 352 | "unexpected low surrogate area", |
2fa16060 | 353 | parser->offset, value); |
6eb1ded4 | 354 | |
3d790dfd | 355 | /* Check for a high surrogate area. */ |
6eb1ded4 | 356 | |
3d790dfd KS |
357 | if ((value & 0xFC00) == 0xD800) { |
358 | ||
2fa16060 KS |
359 | width = 4; |
360 | ||
3d790dfd KS |
361 | /* Check for incomplete surrogate pair. */ |
362 | ||
625fcfe9 | 363 | if (raw_unread < 4) { |
3d790dfd KS |
364 | if (parser->eof) { |
365 | return yaml_parser_set_reader_error(parser, | |
c70abc4d | 366 | "incomplete UTF-16 surrogate pair", |
2fa16060 | 367 | parser->offset, -1); |
3d790dfd KS |
368 | } |
369 | incomplete = 1; | |
370 | break; | |
6eb1ded4 | 371 | } |
6eb1ded4 | 372 | |
3d790dfd | 373 | /* Get the next character. */ |
6eb1ded4 | 374 | |
54815ffd | 375 | value2 = parser->raw_buffer.pointer[low+2] |
625fcfe9 | 376 | + (parser->raw_buffer.pointer[high+2] << 8); |
3d790dfd KS |
377 | |
378 | /* Check for a low surrogate area. */ | |
379 | ||
380 | if ((value2 & 0xFC00) != 0xDC00) | |
381 | return yaml_parser_set_reader_error(parser, | |
c70abc4d | 382 | "expected low surrogate area", |
2fa16060 | 383 | parser->offset+2, value2); |
3d790dfd KS |
384 | |
385 | /* Generate the value of the surrogate pair. */ | |
386 | ||
387 | value = 0x10000 + ((value & 0x3FF) << 10) + (value2 & 0x3FF); | |
3d790dfd KS |
388 | } |
389 | ||
390 | else { | |
2fa16060 | 391 | width = 2; |
3d790dfd | 392 | } |
6eb1ded4 KS |
393 | |
394 | break; | |
54815ffd KS |
395 | |
396 | default: | |
397 | assert(1); /* Impossible. */ | |
6eb1ded4 KS |
398 | } |
399 | ||
3d790dfd KS |
400 | /* Check if the raw buffer contains enough bytes to form a character. */ |
401 | ||
402 | if (incomplete) break; | |
403 | ||
6eb1ded4 KS |
404 | /* |
405 | * Check if the character is in the allowed range: | |
406 | * #x9 | #xA | #xD | [#x20-#x7E] (8 bit) | |
407 | * | #x85 | [#xA0-#xD7FF] | [#xE000-#xFFFD] (16 bit) | |
408 | * | [#x10000-#x10FFFF] (32 bit) | |
409 | */ | |
410 | ||
3d790dfd KS |
411 | if (! (value == 0x09 || value == 0x0A || value == 0x0D |
412 | || (value >= 0x20 && value <= 0x7E) | |
413 | || (value == 0x85) || (value >= 0xA0 && value <= 0xD7FF) | |
414 | || (value >= 0xE000 && value <= 0xFFFD) | |
415 | || (value >= 0x10000 && value <= 0x10FFFF))) | |
416 | return yaml_parser_set_reader_error(parser, | |
c70abc4d | 417 | "control characters are not allowed", |
2fa16060 KS |
418 | parser->offset, value); |
419 | ||
420 | /* Move the raw pointers. */ | |
421 | ||
625fcfe9 | 422 | parser->raw_buffer.pointer += width; |
2fa16060 | 423 | parser->offset += width; |
6eb1ded4 KS |
424 | |
425 | /* Finally put the character into the buffer. */ | |
426 | ||
427 | /* 0000 0000-0000 007F -> 0xxxxxxx */ | |
3d790dfd | 428 | if (value <= 0x7F) { |
625fcfe9 | 429 | *(parser->buffer.last++) = value; |
6eb1ded4 KS |
430 | } |
431 | /* 0000 0080-0000 07FF -> 110xxxxx 10xxxxxx */ | |
3d790dfd | 432 | else if (value <= 0x7FF) { |
625fcfe9 KS |
433 | *(parser->buffer.last++) = 0xC0 + (value >> 6); |
434 | *(parser->buffer.last++) = 0x80 + (value & 0x3F); | |
6eb1ded4 KS |
435 | } |
436 | /* 0000 0800-0000 FFFF -> 1110xxxx 10xxxxxx 10xxxxxx */ | |
3d790dfd | 437 | else if (value <= 0xFFFF) { |
625fcfe9 KS |
438 | *(parser->buffer.last++) = 0xE0 + (value >> 12); |
439 | *(parser->buffer.last++) = 0x80 + ((value >> 6) & 0x3F); | |
440 | *(parser->buffer.last++) = 0x80 + (value & 0x3F); | |
6eb1ded4 KS |
441 | } |
442 | /* 0001 0000-0010 FFFF -> 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */ | |
443 | else { | |
625fcfe9 KS |
444 | *(parser->buffer.last++) = 0xF0 + (value >> 18); |
445 | *(parser->buffer.last++) = 0x80 + ((value >> 12) & 0x3F); | |
446 | *(parser->buffer.last++) = 0x80 + ((value >> 6) & 0x3F); | |
447 | *(parser->buffer.last++) = 0x80 + (value & 0x3F); | |
6eb1ded4 | 448 | } |
2fa16060 KS |
449 | |
450 | parser->unread ++; | |
451 | } | |
452 | ||
453 | /* On EOF, put NUL into the buffer and return. */ | |
454 | ||
455 | if (parser->eof) { | |
625fcfe9 | 456 | *(parser->buffer.last++) = '\0'; |
2fa16060 KS |
457 | parser->unread ++; |
458 | return 1; | |
95b98ba9 | 459 | } |
2fa16060 | 460 | |
95b98ba9 KS |
461 | } |
462 | ||
c9479c77 KS |
463 | if (parser->offset >= PTRDIFF_MAX) |
464 | return yaml_parser_set_reader_error(parser, "input is too long", | |
465 | PTRDIFF_MAX, -1); | |
466 | ||
3d790dfd | 467 | return 1; |
6eb1ded4 | 468 | } |
95b98ba9 | 469 |