mirror of https://github.com/hashicorp/consul
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
412 lines
13 KiB
412 lines
13 KiB
package yaml |
|
|
|
import ( |
|
"io" |
|
) |
|
|
|
// Set the reader error and return 0. |
|
func yaml_parser_set_reader_error(parser *yaml_parser_t, problem string, offset int, value int) bool { |
|
parser.error = yaml_READER_ERROR |
|
parser.problem = problem |
|
parser.problem_offset = offset |
|
parser.problem_value = value |
|
return false |
|
} |
|
|
|
// Byte order marks. |
|
const ( |
|
bom_UTF8 = "\xef\xbb\xbf" |
|
bom_UTF16LE = "\xff\xfe" |
|
bom_UTF16BE = "\xfe\xff" |
|
) |
|
|
|
// Determine the input stream encoding by checking the BOM symbol. If no BOM is |
|
// found, the UTF-8 encoding is assumed. Return 1 on success, 0 on failure. |
|
func yaml_parser_determine_encoding(parser *yaml_parser_t) bool { |
|
// Ensure that we had enough bytes in the raw buffer. |
|
for !parser.eof && len(parser.raw_buffer)-parser.raw_buffer_pos < 3 { |
|
if !yaml_parser_update_raw_buffer(parser) { |
|
return false |
|
} |
|
} |
|
|
|
// Determine the encoding. |
|
buf := parser.raw_buffer |
|
pos := parser.raw_buffer_pos |
|
avail := len(buf) - pos |
|
if avail >= 2 && buf[pos] == bom_UTF16LE[0] && buf[pos+1] == bom_UTF16LE[1] { |
|
parser.encoding = yaml_UTF16LE_ENCODING |
|
parser.raw_buffer_pos += 2 |
|
parser.offset += 2 |
|
} else if avail >= 2 && buf[pos] == bom_UTF16BE[0] && buf[pos+1] == bom_UTF16BE[1] { |
|
parser.encoding = yaml_UTF16BE_ENCODING |
|
parser.raw_buffer_pos += 2 |
|
parser.offset += 2 |
|
} else if avail >= 3 && buf[pos] == bom_UTF8[0] && buf[pos+1] == bom_UTF8[1] && buf[pos+2] == bom_UTF8[2] { |
|
parser.encoding = yaml_UTF8_ENCODING |
|
parser.raw_buffer_pos += 3 |
|
parser.offset += 3 |
|
} else { |
|
parser.encoding = yaml_UTF8_ENCODING |
|
} |
|
return true |
|
} |
|
|
|
// Update the raw buffer. |
|
func yaml_parser_update_raw_buffer(parser *yaml_parser_t) bool { |
|
size_read := 0 |
|
|
|
// Return if the raw buffer is full. |
|
if parser.raw_buffer_pos == 0 && len(parser.raw_buffer) == cap(parser.raw_buffer) { |
|
return true |
|
} |
|
|
|
// Return on EOF. |
|
if parser.eof { |
|
return true |
|
} |
|
|
|
// Move the remaining bytes in the raw buffer to the beginning. |
|
if parser.raw_buffer_pos > 0 && parser.raw_buffer_pos < len(parser.raw_buffer) { |
|
copy(parser.raw_buffer, parser.raw_buffer[parser.raw_buffer_pos:]) |
|
} |
|
parser.raw_buffer = parser.raw_buffer[:len(parser.raw_buffer)-parser.raw_buffer_pos] |
|
parser.raw_buffer_pos = 0 |
|
|
|
// Call the read handler to fill the buffer. |
|
size_read, err := parser.read_handler(parser, parser.raw_buffer[len(parser.raw_buffer):cap(parser.raw_buffer)]) |
|
parser.raw_buffer = parser.raw_buffer[:len(parser.raw_buffer)+size_read] |
|
if err == io.EOF { |
|
parser.eof = true |
|
} else if err != nil { |
|
return yaml_parser_set_reader_error(parser, "input error: "+err.Error(), parser.offset, -1) |
|
} |
|
return true |
|
} |
|
|
|
// Ensure that the buffer contains at least `length` characters. |
|
// Return true on success, false on failure. |
|
// |
|
// The length is supposed to be significantly less that the buffer size. |
|
func yaml_parser_update_buffer(parser *yaml_parser_t, length int) bool { |
|
if parser.read_handler == nil { |
|
panic("read handler must be set") |
|
} |
|
|
|
// [Go] This function was changed to guarantee the requested length size at EOF. |
|
// The fact we need to do this is pretty awful, but the description above implies |
|
// for that to be the case, and there are tests |
|
|
|
// If the EOF flag is set and the raw buffer is empty, do nothing. |
|
if parser.eof && parser.raw_buffer_pos == len(parser.raw_buffer) { |
|
// [Go] ACTUALLY! Read the documentation of this function above. |
|
// This is just broken. To return true, we need to have the |
|
// given length in the buffer. Not doing that means every single |
|
// check that calls this function to make sure the buffer has a |
|
// given length is Go) panicking; or C) accessing invalid memory. |
|
//return true |
|
} |
|
|
|
// Return if the buffer contains enough characters. |
|
if parser.unread >= length { |
|
return true |
|
} |
|
|
|
// Determine the input encoding if it is not known yet. |
|
if parser.encoding == yaml_ANY_ENCODING { |
|
if !yaml_parser_determine_encoding(parser) { |
|
return false |
|
} |
|
} |
|
|
|
// Move the unread characters to the beginning of the buffer. |
|
buffer_len := len(parser.buffer) |
|
if parser.buffer_pos > 0 && parser.buffer_pos < buffer_len { |
|
copy(parser.buffer, parser.buffer[parser.buffer_pos:]) |
|
buffer_len -= parser.buffer_pos |
|
parser.buffer_pos = 0 |
|
} else if parser.buffer_pos == buffer_len { |
|
buffer_len = 0 |
|
parser.buffer_pos = 0 |
|
} |
|
|
|
// Open the whole buffer for writing, and cut it before returning. |
|
parser.buffer = parser.buffer[:cap(parser.buffer)] |
|
|
|
// Fill the buffer until it has enough characters. |
|
first := true |
|
for parser.unread < length { |
|
|
|
// Fill the raw buffer if necessary. |
|
if !first || parser.raw_buffer_pos == len(parser.raw_buffer) { |
|
if !yaml_parser_update_raw_buffer(parser) { |
|
parser.buffer = parser.buffer[:buffer_len] |
|
return false |
|
} |
|
} |
|
first = false |
|
|
|
// Decode the raw buffer. |
|
inner: |
|
for parser.raw_buffer_pos != len(parser.raw_buffer) { |
|
var value rune |
|
var width int |
|
|
|
raw_unread := len(parser.raw_buffer) - parser.raw_buffer_pos |
|
|
|
// Decode the next character. |
|
switch parser.encoding { |
|
case yaml_UTF8_ENCODING: |
|
// 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. |
|
octet := parser.raw_buffer[parser.raw_buffer_pos] |
|
switch { |
|
case octet&0x80 == 0x00: |
|
width = 1 |
|
case octet&0xE0 == 0xC0: |
|
width = 2 |
|
case octet&0xF0 == 0xE0: |
|
width = 3 |
|
case octet&0xF8 == 0xF0: |
|
width = 4 |
|
default: |
|
// The leading octet is invalid. |
|
return yaml_parser_set_reader_error(parser, |
|
"invalid leading UTF-8 octet", |
|
parser.offset, int(octet)) |
|
} |
|
|
|
// Check if the raw buffer contains an incomplete character. |
|
if width > raw_unread { |
|
if parser.eof { |
|
return yaml_parser_set_reader_error(parser, |
|
"incomplete UTF-8 octet sequence", |
|
parser.offset, -1) |
|
} |
|
break inner |
|
} |
|
|
|
// Decode the leading octet. |
|
switch { |
|
case octet&0x80 == 0x00: |
|
value = rune(octet & 0x7F) |
|
case octet&0xE0 == 0xC0: |
|
value = rune(octet & 0x1F) |
|
case octet&0xF0 == 0xE0: |
|
value = rune(octet & 0x0F) |
|
case octet&0xF8 == 0xF0: |
|
value = rune(octet & 0x07) |
|
default: |
|
value = 0 |
|
} |
|
|
|
// Check and decode the trailing octets. |
|
for k := 1; k < width; k++ { |
|
octet = parser.raw_buffer[parser.raw_buffer_pos+k] |
|
|
|
// Check if the octet is valid. |
|
if (octet & 0xC0) != 0x80 { |
|
return yaml_parser_set_reader_error(parser, |
|
"invalid trailing UTF-8 octet", |
|
parser.offset+k, int(octet)) |
|
} |
|
|
|
// Decode the octet. |
|
value = (value << 6) + rune(octet&0x3F) |
|
} |
|
|
|
// Check the length of the sequence against the value. |
|
switch { |
|
case width == 1: |
|
case width == 2 && value >= 0x80: |
|
case width == 3 && value >= 0x800: |
|
case width == 4 && value >= 0x10000: |
|
default: |
|
return yaml_parser_set_reader_error(parser, |
|
"invalid length of a UTF-8 sequence", |
|
parser.offset, -1) |
|
} |
|
|
|
// Check the range of the value. |
|
if value >= 0xD800 && value <= 0xDFFF || value > 0x10FFFF { |
|
return yaml_parser_set_reader_error(parser, |
|
"invalid Unicode character", |
|
parser.offset, int(value)) |
|
} |
|
|
|
case yaml_UTF16LE_ENCODING, yaml_UTF16BE_ENCODING: |
|
var low, high int |
|
if parser.encoding == yaml_UTF16LE_ENCODING { |
|
low, high = 0, 1 |
|
} else { |
|
low, high = 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 raw_unread < 2 { |
|
if parser.eof { |
|
return yaml_parser_set_reader_error(parser, |
|
"incomplete UTF-16 character", |
|
parser.offset, -1) |
|
} |
|
break inner |
|
} |
|
|
|
// Get the character. |
|
value = rune(parser.raw_buffer[parser.raw_buffer_pos+low]) + |
|
(rune(parser.raw_buffer[parser.raw_buffer_pos+high]) << 8) |
|
|
|
// Check for unexpected low surrogate area. |
|
if value&0xFC00 == 0xDC00 { |
|
return yaml_parser_set_reader_error(parser, |
|
"unexpected low surrogate area", |
|
parser.offset, int(value)) |
|
} |
|
|
|
// Check for a high surrogate area. |
|
if value&0xFC00 == 0xD800 { |
|
width = 4 |
|
|
|
// Check for incomplete surrogate pair. |
|
if raw_unread < 4 { |
|
if parser.eof { |
|
return yaml_parser_set_reader_error(parser, |
|
"incomplete UTF-16 surrogate pair", |
|
parser.offset, -1) |
|
} |
|
break inner |
|
} |
|
|
|
// Get the next character. |
|
value2 := rune(parser.raw_buffer[parser.raw_buffer_pos+low+2]) + |
|
(rune(parser.raw_buffer[parser.raw_buffer_pos+high+2]) << 8) |
|
|
|
// Check for a low surrogate area. |
|
if value2&0xFC00 != 0xDC00 { |
|
return yaml_parser_set_reader_error(parser, |
|
"expected low surrogate area", |
|
parser.offset+2, int(value2)) |
|
} |
|
|
|
// Generate the value of the surrogate pair. |
|
value = 0x10000 + ((value & 0x3FF) << 10) + (value2 & 0x3FF) |
|
} else { |
|
width = 2 |
|
} |
|
|
|
default: |
|
panic("impossible") |
|
} |
|
|
|
// Check if the character is in the allowed range: |
|
// #x9 | #xA | #xD | [#x20-#x7E] (8 bit) |
|
// | #x85 | [#xA0-#xD7FF] | [#xE000-#xFFFD] (16 bit) |
|
// | [#x10000-#x10FFFF] (32 bit) |
|
switch { |
|
case value == 0x09: |
|
case value == 0x0A: |
|
case value == 0x0D: |
|
case value >= 0x20 && value <= 0x7E: |
|
case value == 0x85: |
|
case value >= 0xA0 && value <= 0xD7FF: |
|
case value >= 0xE000 && value <= 0xFFFD: |
|
case value >= 0x10000 && value <= 0x10FFFF: |
|
default: |
|
return yaml_parser_set_reader_error(parser, |
|
"control characters are not allowed", |
|
parser.offset, int(value)) |
|
} |
|
|
|
// Move the raw pointers. |
|
parser.raw_buffer_pos += width |
|
parser.offset += width |
|
|
|
// Finally put the character into the buffer. |
|
if value <= 0x7F { |
|
// 0000 0000-0000 007F . 0xxxxxxx |
|
parser.buffer[buffer_len+0] = byte(value) |
|
buffer_len += 1 |
|
} else if value <= 0x7FF { |
|
// 0000 0080-0000 07FF . 110xxxxx 10xxxxxx |
|
parser.buffer[buffer_len+0] = byte(0xC0 + (value >> 6)) |
|
parser.buffer[buffer_len+1] = byte(0x80 + (value & 0x3F)) |
|
buffer_len += 2 |
|
} else if value <= 0xFFFF { |
|
// 0000 0800-0000 FFFF . 1110xxxx 10xxxxxx 10xxxxxx |
|
parser.buffer[buffer_len+0] = byte(0xE0 + (value >> 12)) |
|
parser.buffer[buffer_len+1] = byte(0x80 + ((value >> 6) & 0x3F)) |
|
parser.buffer[buffer_len+2] = byte(0x80 + (value & 0x3F)) |
|
buffer_len += 3 |
|
} else { |
|
// 0001 0000-0010 FFFF . 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx |
|
parser.buffer[buffer_len+0] = byte(0xF0 + (value >> 18)) |
|
parser.buffer[buffer_len+1] = byte(0x80 + ((value >> 12) & 0x3F)) |
|
parser.buffer[buffer_len+2] = byte(0x80 + ((value >> 6) & 0x3F)) |
|
parser.buffer[buffer_len+3] = byte(0x80 + (value & 0x3F)) |
|
buffer_len += 4 |
|
} |
|
|
|
parser.unread++ |
|
} |
|
|
|
// On EOF, put NUL into the buffer and return. |
|
if parser.eof { |
|
parser.buffer[buffer_len] = 0 |
|
buffer_len++ |
|
parser.unread++ |
|
break |
|
} |
|
} |
|
// [Go] Read the documentation of this function above. To return true, |
|
// we need to have the given length in the buffer. Not doing that means |
|
// every single check that calls this function to make sure the buffer |
|
// has a given length is Go) panicking; or C) accessing invalid memory. |
|
// This happens here due to the EOF above breaking early. |
|
for buffer_len < length { |
|
parser.buffer[buffer_len] = 0 |
|
buffer_len++ |
|
} |
|
parser.buffer = parser.buffer[:buffer_len] |
|
return true |
|
}
|
|
|