diff options
Diffstat (limited to 'src/reader.c')
| -rw-r--r-- | src/reader.c | 325 |
1 files changed, 220 insertions, 105 deletions
diff --git a/src/reader.c b/src/reader.c index 440a88f..5ee8c43 100644 --- a/src/reader.c +++ b/src/reader.c @@ -7,51 +7,20 @@ #include <assert.h> -/* Check for the UTF-16-BE BOM. */ -#define IS_UTF16BE_BOM(pointer) ((pointer)[0] == 0xFE && (pointer)[1] == 0xFF) - -/* Check for the UTF-16-LE BOM. */ -#define IS_UTF16LE_BOM(pointer) ((pointer)[0] == 0xFF && (pointer)[1] == 0xFE) - -/* Get a UTF-16-BE character. */ -#define UTF16BE_CHAR(pointer) ((pointer)[0] << 8 + (pointer)[1]) - -/* Get a UTF-16-LE character. */ -#define UTF16LE_CHAR(pointer) ((pointer)[0] + (pointer)[1] << 8) - /* - * From http://www.ietf.org/rfc/rfc3629.txt: - * - * Char. number range | UTF-8 octet sequence - * (hexadecimal) | (binary) - * --------------------+--------------------------------------------- - * 0000 0000-0000 007F | 0xxxxxxx - * 0000 0080-0000 07FF | 110xxxxx 10xxxxxx - * 0000 0800-0000 FFFF | 1110xxxx 10xxxxxx 10xxxxxx - * 0001 0000-0010 FFFF | 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx + * Set the reader error and return 0. */ -/* Get the length of a UTF-8 character (0 on error). */ -#define UTF8_LENGTH(pointer) \ - ((pointer)[0] < 0x80 ? 1 : \ - (pointer)[0] < 0xC0 ? 0 : \ - (pointer)[0] < 0xE0 ? 2 : \ - (pointer)[0] < 0xF0 ? 3 : \ - (pointer)[0] < 0xF8 ? 4 : 0) - -/* Get the value of the first byte of a UTF-8 sequence (0xFF on error). */ -#define UTF8_FIRST_CHUNK(pointer) \ - ((pointer)[0] < 0x80 ? (pointer)[0] & 0x7F : \ - (pointer)[0] < 0xC0 ? 0xFF : \ - (pointer)[0] < 0xE0 ? (pointer)[0] & 0x1F : \ - (pointer)[0] < 0xF0 ? (pointer)[0] & 0x0F : \ - (pointer)[0] < 0xF8 ? (pointer)[0] & 0x07 : 0xFF) +int +yaml_parser_set_reader_error(yaml_parser_t *parser, const char *problem) +{ + parser->error = YAML_READER_ERROR; + parser->problem = problem; + parser->problem_offset = parser->offset; -/* Get the value of a non-first byte of a UTF-8 sequence (0xFF on error). */ -#define UTF8_NEXT_CHUNK(pointer) \ - ((pointer)[0] >= 0x80 && (pointer)[0] < 0xC0 ? (pointer)[0] & 0x3F : 0xFF) + return 0; +} -/* Determine the length of a UTF-8 character. */ /* * Ensure that the buffer contains at least length characters. @@ -102,12 +71,19 @@ yaml_parser_update_buffer(yaml_parser_t *parser, size_t length) if (!yaml_parser_update_raw_buffer(parser)) return 0; + /* If the raw buffer is empty, it is EOF. */ + + if (!parser->raw_unread) return 1; + /* Decode the raw buffer. */ while (parser->raw_unread) { - unsigned int ch; + unsigned int value, value2; int incomplete = 0; + unsigned char utf8_octet; + unsigned int utf8_length; + int k, low, high; /* Decode the next character. */ @@ -115,81 +91,200 @@ yaml_parser_update_buffer(yaml_parser_t *parser, size_t length) { case YAML_UTF8_ENCODING: - unsigned int utf8_length = UTF8_LENGTH(parser->raw_pointer); - unsigned int utf8_chunk; + /* + * Decode a UTF-8 character. Check RFC 3629 + * (http://www.ietf.org/rfc/rfc3629.txt) for more details. + * + * The following table (taken from the RFC) is used for + * decoding. + * + * Char. number range | UTF-8 octet sequence + * (hexadecimal) | (binary) + * --------------------+------------------------------------ + * 0000 0000-0000 007F | 0xxxxxxx + * 0000 0080-0000 07FF | 110xxxxx 10xxxxxx + * 0000 0800-0000 FFFF | 1110xxxx 10xxxxxx 10xxxxxx + * 0001 0000-0010 FFFF | 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx + * + * Additionally, the characters in the range 0xD800-0xDFFF + * are prohibited as they are reserved for use with UTF-16 + * surrogate pairs. + */ + + /* Determine the length of the UTF-8 sequence. */ + + utf8_octet = parser->raw_pointer[0]; + utf8_length = ( + (utf8_octet & 0x80) == 0x00 ? 1 : + (utf8_octet & 0xE0) == 0xC0 ? 2 : + (utf8_octet & 0xF0) == 0xE0 ? 3 : + (utf8_octet & 0xF8) == 0xF0 ? 4 : 0); + + /* Check if the leading octet is valid. */ + + if (!utf8_length) + return yaml_parser_set_reader_error(parser, + "Invalid leading UTF-8 octet"); /* Check if the raw buffer contains an incomplete character. */ if (utf8_length > parser->raw_unread) { if (parser->eof) { - parser->error = YAML_READER_ERROR; - return 0; + return yaml_parser_set_reader_error(parser, + "Incomplete UTF-8 octet sequence"); } incomplete = 1; + break; } - /* Get the character checking it for validity. */ + /* Decode the leading octet. */ - utf8_chunk = UTF8_FIRST_CHUNK(parser->raw_pointer ++); - if (utf8_chunk == 0xFF) { - parser->error = YAML_READER_ERROR; - return 0; - } - ch = utf8_chunk; - parser->raw_unread --; - while (-- utf8_length) { - utf8_chunk = UTF8_NEXT_CHUNK(parser->raw_pointer ++); - if (utf8_chunk == 0xFF) { - parser->error = YAML_READER_ERROR; - return 0; - } - ch = ch << 6 + utf8_chunk; - parser->raw_unread --; + value = ( + (utf8_octet & 0x80) == 0x00 ? utf8_octet & 0x7F : + (utf8_octet & 0xE0) == 0xC0 ? utf8_octet & 0x1F : + (utf8_octet & 0xF0) == 0xE0 ? utf8_octet & 0x0F : + (utf8_octet & 0xF8) == 0xF0 ? utf8_octet & 0x07 : 0); + + /* Check and decode the trailing octets. */ + + for (k = 1; k < utf8_length; k ++) + { + utf8_octet = parser->raw_pointer[k]; + + /* Check if the octet is valid. */ + + if ((utf8_octet & 0xC0) != 0x80) + return yaml_parser_set_reader_error(parser, + "Invalid trailing UTF-8 octet"); + + /* Decode the octet. */ + + value = (value << 6) + (utf8_octet & 0x3F); } + /* Check the length of the sequence against the value. */ + + if (!((utf8_length == 1) || + (utf8_length == 2 && value >= 0x80) || + (utf8_length == 3 && value >= 0x800) || + (utf8_length == 4 && value >= 0x10000))) + return yaml_parser_set_reader_error(parser, + "Invalid length of a UTF-8 sequence"); + + /* Check the range of the value. */ + + if ((value >= 0xD800 && value <= 0xDFFF) || value > 0x10FFFF) + return yaml_parser_set_reader_error(parser, + "Invalid Unicode character"); + + parser->raw_pointer += utf8_length; + parser->raw_unread -= utf8_length; + parser->offset += utf8_length; + break; case YAML_UTF16LE_ENCODING: + case YAML_UTF16BE_ENCODING: - /* Check if the raw buffer contains an incomplete character. */ + low = (parser->encoding == YAML_UTF16LE_ENCODING ? 0 : 1); + high = (parser->encoding == YAML_UTF16LE_ENCODING ? 1 : 0); + + /* + * The UTF-16 encoding is not as simple as one might + * naively think. Check RFC 2781 + * (http://www.ietf.org/rfc/rfc2781.txt). + * + * Normally, two subsequent bytes describe a Unicode + * character. However a special technique (called a + * surrogate pair) is used for specifying character + * values larger than 0xFFFF. + * + * A surrogate pair consists of two pseudo-characters: + * high surrogate area (0xD800-0xDBFF) + * low surrogate area (0xDC00-0xDFFF) + * + * The following formulas are used for decoding + * and encoding characters using surrogate pairs: + * + * U = U' + 0x10000 (0x01 00 00 <= U <= 0x10 FF FF) + * U' = yyyyyyyyyyxxxxxxxxxx (0 <= U' <= 0x0F FF FF) + * W1 = 110110yyyyyyyyyy + * W2 = 110111xxxxxxxxxx + * + * where U is the character value, W1 is the high surrogate + * area, W2 is the low surrogate area. + */ + + /* Check for incomplete UTF-16 character. */ if (parser->raw_unread < 2) { if (parser->eof) { - parser->error = YAML_READER_ERROR; - return 0; + return yaml_parser_set_reader_error(parser, + "Incomplete UTF-16 character"); } incomplete = 1; + break; } - /* Get the current character. */ + /* Get the character. */ - ch = UTF16LE_CHAR(parser->raw_pointer); - parser->raw_pointer += 2; - parser->raw_unread -= 2; + value = parser->raw_pointer[low] + + (parser->raw_pointer[high] << 8); - break; + /* Check for unexpected low surrogate area. */ - case YAML_UTF16BE_ENCODING: + if ((value & 0xFC00) == 0xDC00) + return yaml_parser_set_reader_error(parser, + "Unexpected low surrogate area"); - /* Check if the raw buffer contains an incomplete character. */ + /* Check for a high surrogate area. */ - if (parser->raw_unread < 2) { - if (parser->eof) { - parser->error = YAML_READER_ERROR; - return 0; + if ((value & 0xFC00) == 0xD800) { + + /* Check for incomplete surrogate pair. */ + + if (parser->raw_unread < 4) { + if (parser->eof) { + return yaml_parser_set_reader_error(parser, + "Incomplete UTF-16 surrogate pair"); + } + incomplete = 1; + break; } - incomplete = 1; - } - /* Get the current character. */ + /* Get the next character. */ - ch = UTF16BE_CHAR(parser->raw_pointer); - parser->raw_pointer += 2; - parser->raw_unread -= 2; + unsigned int value2 = parser->raw_pointer[low+2] + + (parser->raw_pointer[high+2] << 8); + + /* Check for a low surrogate area. */ + + if ((value2 & 0xFC00) != 0xDC00) + return yaml_parser_set_reader_error(parser, + "Expected low surrogate area"); + + /* Generate the value of the surrogate pair. */ + + value = 0x10000 + ((value & 0x3FF) << 10) + (value2 & 0x3FF); + + parser->raw_pointer += 4; + parser->raw_unread -= 4; + parser->offset += 4; + } + + else { + parser->raw_pointer += 2; + parser->raw_unread -= 2; + parser->offset += 4; + } break; } + /* Check if the raw buffer contains enough bytes to form a character. */ + + if (incomplete) break; + /* * Check if the character is in the allowed range: * #x9 | #xA | #xD | [#x20-#x7E] (8 bit) @@ -197,39 +292,42 @@ yaml_parser_update_buffer(yaml_parser_t *parser, size_t length) * | [#x10000-#x10FFFF] (32 bit) */ - if (! (ch == 0x09 || ch == 0x0A || ch == 0x0D - || (ch >= 0x20 && ch <= 0x7E) - || (ch == 0x85) || (ch >= 0xA0 && ch <= 0xD7FF) - || (ch >= 0xE000 && ch <= 0xFFFD) - || (ch >= 0x10000 && ch <= 0x10FFFF))) { - parser->error = YAML_READER_ERROR; - return 0; - } + if (! (value == 0x09 || value == 0x0A || value == 0x0D + || (value >= 0x20 && value <= 0x7E) + || (value == 0x85) || (value >= 0xA0 && value <= 0xD7FF) + || (value >= 0xE000 && value <= 0xFFFD) + || (value >= 0x10000 && value <= 0x10FFFF))) + return yaml_parser_set_reader_error(parser, + "Control characters are not allowed"); /* Finally put the character into the buffer. */ /* 0000 0000-0000 007F -> 0xxxxxxx */ - if (ch <= 0x7F) { - *(parser->buffer_end++) = ch; + if (value <= 0x7F) { + *(parser->buffer_end++) = value; } /* 0000 0080-0000 07FF -> 110xxxxx 10xxxxxx */ - else if (ch <= 0x7FF) { - *(parser->buffer_end++) = 0xC0 + (ch >> 6) & 0x1F; - *(parser->buffer_end++) = 0x80 + ch & 0x3F; + else if (value <= 0x7FF) { + *(parser->buffer_end++) = 0xC0 + (value >> 6); + *(parser->buffer_end++) = 0x80 + value & 0x3F; } /* 0000 0800-0000 FFFF -> 1110xxxx 10xxxxxx 10xxxxxx */ - else if (ch <= 0xFFFF) { - *(parser->buffer_end++) = 0x80 + ch & 0x3F; - *(parser->buffer_end++) = 0xC0 + (ch >> 6) & 0x1F; - + else if (value <= 0xFFFF) { + *(parser->buffer_end++) = 0xE0 + (value >> 12); + *(parser->buffer_end++) = 0x80 + (value >> 6) & 0x3F; + *(parser->buffer_end++) = 0x80 + value & 0x3F; } /* 0001 0000-0010 FFFF -> 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */ else { + *(parser->buffer_end++) = 0xF0 + (value >> 18); + *(parser->buffer_end++) = 0x80 + (value >> 12) & 0x3F; + *(parser->buffer_end++) = 0x80 + (value >> 6) & 0x3F; + *(parser->buffer_end++) = 0x80 + value & 0x3F; } } - } + return 1; } /* @@ -237,12 +335,16 @@ yaml_parser_update_buffer(yaml_parser_t *parser, size_t length) * found, the UTF-8 encoding is assumed. Return 1 on success, 0 on failure. */ +#define BOM_UTF8 "\xef\xbb\xbf" +#define BOM_UTF16LE "\xff\xfe" +#define BOM_UTF16BE "\xfe\xff" + int yaml_parser_determine_encoding(yaml_parser_t *parser) { /* Ensure that we had enough bytes in the raw buffer. */ - while (!parser->eof && parser->raw_unread < 2) { + while (!parser->eof && parser->raw_unread < 3) { if (!yaml_parser_update_raw_buffer(parser)) { return 0; } @@ -250,15 +352,29 @@ yaml_parser_determine_encoding(yaml_parser_t *parser) /* Determine the encoding. */ - if (parser->raw_unread >= 2 && IS_UTF16BE_BOM(parser->raw_pointer)) { + if (parser->raw_unread >= 2 + && !memcmp(parser->raw_pointer, BOM_UTF16LE, 2)) { + parser->encoding = YAML_UTF16LE_ENCODING; + parser->raw_pointer += 2; + parser->raw_unread -= 2; + } + else if (parser->raw_unread >= 2 + && !memcmp(parser->raw_pointer, BOM_UTF16BE, 2)) { parser->encoding = YAML_UTF16BE_ENCODING; + parser->raw_pointer += 2; + parser->raw_unread -= 2; } - else if (parser->raw_unread >= 2 && IS_UTF16LE_BOM(parser->raw_pointer)) { - parser->encoding = YAML_UTF16LE_ENCODING; + else if (parser->raw_unread >= 3 + && !memcmp(parser->raw_pointer, BOM_UTF8, 3)) { + parser->encoding = YAML_UTF8_ENCODING; + parser->raw_pointer += 3; + parser->raw_unread -= 3; } else { parser->encoding = YAML_UTF8_ENCODING; } + + return 1; } /* @@ -291,8 +407,7 @@ yaml_parser_update_raw_buffer(yaml_parser_t *parser) parser->raw_buffer + parser->raw_unread, YAML_RAW_BUFFER_SIZE - parser->raw_unread, &size_read)) { - parser->error = YAML_READER_ERROR; - return 0; + return yaml_parser_set_reader_error(parser, "Input error"); } parser->raw_unread += size_read; if (!size_read) { |