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#--
#Copyright 2007 Nominet UK
#
#Licensed under the Apache License, Version 2.0 (the "License");
#you may not use this file except in compliance with the License.
#You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
#Unless required by applicable law or agreed to in writing, software
#distributed under the License is distributed on an "AS IS" BASIS,
#WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#See the License for the specific language governing permissions and
#limitations under the License.
#++
begin
require 'jcode'
rescue LoadError => e
end
module Dnsruby
class RR
#Class for DNS Text (TXT) resource records.
#RFC 1035 Section 3.3.14
class TXT < RR
ClassValue = nil #:nodoc: all
TypeValue = Types::TXT #:nodoc: all
#List of the individual elements
attr_accessor :strings
def data
@strings[0]
end
def from_data(data)
@strings = data
end
def from_hash(hash)
if (hash.has_key?:strings)
from_string(hash[:strings])
end
end
ESCAPE_CHARS = {"b" => 8, "t" => 9, "n" => 10, "v" => 11, "f" => 12, "r" => 13}
ESCAPE_CODES = ESCAPE_CHARS.invert
def from_string(input)
@strings = TXT.parse(input)
end
def TXT.parse(input)
# Need to look out for special characters.
# Need to split the input up into strings (which are defined by non-escaped " characters)
# Then need to fix up any \ escape characters (should just be " and ; and binary?)
# Sadly, it's going to be easiest just to scan through this character by character...
in_escaped = false
in_string = false
count = -1
strings = []
current_binary = ""
current_quote_char = '"'
unquoted = false
seen_strings = false
pos = 0
input.sub!(/^\s*\(\s*/, "")
input.sub!(/\s*\)\s*$/, "")
input.each_char {|c|
if (((c == "'") || (c == '"')) && (!in_escaped) && (!unquoted))
if (!in_string)
seen_strings = true
current_quote_char = c
in_string = true
count+=1
strings[count] = ""
else
if (c == current_quote_char)
in_string = false
else
strings[count]+=c
end
end
else
if (seen_strings && !in_string)
next
end
if (pos == 0)
unquoted = true
count+=1
strings[count] = ""
elsif (unquoted)
if (c == " ")
count+=1
strings[count] = ""
pos += 1
next
end
end
if (c == "\\")
if (in_escaped)
in_escaped = false
strings[count]+=(c)
else
in_escaped = true
end
else
if (in_escaped)
# Build up the binary
if (c == ";") || (c == '"')
strings[count]+=c
in_escaped = false
elsif (ESCAPE_CHARS[c])
in_escaped=false
strings[count]+=ESCAPE_CHARS[c].chr
elsif (c<"0" || c>"9")
in_escaped = false
strings[count]+=c
else
# Must be building up three digit string to identify binary value?
# if (c >= "0" && c <= "9")
current_binary += c
# end
if ((current_binary.length == 3) ) # || (c < "0" || c > "9"))
strings[count]+=current_binary.to_i.chr
in_escaped = false
current_binary = ""
end
end
else
strings[count]+=(c)
end
end
end
pos += 1
}
return strings
end
def TXT.display(str, do_escapes = true)
output = ""
# Probably need to scan through each string manually
# Make sure to remember to escape binary characters.
# Go through copying to output, and adding "\" characters as necessary?
str.each_byte {|c|
if (c == 34) || (c == 92) # || (c == 59)
if (do_escapes)
output+='\\'
end
output+=c.chr
elsif (c < 32) # c is binary
if (ESCAPE_CODES[c])
output += c.chr
else
output+= '\\'
num = c.to_i.to_s
(3-num.length).times {|i|
num="0"+num
}
output+= num # Need a 3 digit number here.
end
else
output += c.chr
end
}
return output
end
def rdata_to_string
if (defined?@strings)
temp = []
@strings.each {|str|
output = TXT.display(str)
temp.push("\"#{output}\"")
}
return temp.join(' ')
end
return ''
end
def encode_rdata(msg, canonical=false) #:nodoc: all
msg.put_string_list(@strings)
end
def self.decode_rdata(msg) #:nodoc: all
strings = msg.get_string_list
return self.new(strings)
end
end
end
end
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