Class: DNS::Zone

Inherits:
Object
  • Object
show all
Defined in:
lib/dns/zone.rb,
lib/dns/zone/rr.rb,
lib/dns/zone/version.rb

Overview

Represents a ‘whole’ zone of many resource records (RRs).

This is also the primary namespace for the ‘dns-zone` gem.

Defined Under Namespace

Modules: RR Classes: TestCase

Constant Summary collapse

Version =

Version number (major.minor.tiny)

'0.1.2'

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Zone

Returns a new instance of Zone.



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# File 'lib/dns/zone.rb', line 14

def initialize
  @records = []
end

Instance Attribute Details

#origin ⇒ Object

Returns the value of attribute origin.



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# File 'lib/dns/zone.rb', line 12

def origin
  @origin
end

#records ⇒ Object

Returns the value of attribute records.



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# File 'lib/dns/zone.rb', line 12

def records
  @records
end

#ttl ⇒ Object

Returns the value of attribute ttl.



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# File 'lib/dns/zone.rb', line 12

def ttl
  @ttl
end

Class Method Details

.extract_entries(string) ⇒ Object 



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# File 'lib/dns/zone.rb', line 64

def self.extract_entries(string)
  entries = []
  mode = :line
  entry = ''

  parentheses_ref_count = 0

  string.lines.each do |line|
    # strip comments unless escaped
    line = line.gsub(/(?<!\\);.*/o, '').chomp

    next if line.gsub(/\s+/, '').empty?

    # append to entry line
    entry << line

    quotes = entry.count('"')
    has_quotes = quotes > 0

    parentheses = entry.count('()')
    has_parentheses = parentheses > 0

    if has_quotes
      character_strings = entry.scan(/("(?:[^"\\]+|\\.)*")/).join(' ')
      without = entry.gsub(/"((?:[^"\\]+|\\.)*)"/, '')
      parentheses_ref_count = without.count('(') - without.count(')')
    else
      parentheses_ref_count = entry.count('(') - entry.count(')')
    end

    # are parentheses balanced?
    if parentheses_ref_count == 0
      if has_quotes
        without.gsub!(/[()]/, '')
        without.gsub!(/[ ]{2,}/, '  ')
        #entries << (without + character_strings)
        entry = (without + character_strings)
      else
        entry.gsub!(/[()]/, '')
        entry.gsub!(/[ ]{2,}/, '  ')
        entry.gsub!(/[ ]+$/, '')
        #entries << entry
      end
      entries << entry
      entry = ''
    end

  end

  return entries
end

.load(string) ⇒ Object

FROM RFC:

The format of these files is a sequence of entries.  Entries are
predominantly line-oriented, though parentheses can be used to continue
a list of items across a line boundary, and text literals can contain
CRLF within the text.  Any combination of tabs and spaces act as a
delimiter between the separate items that make up an entry.  The end of
any line in the master file can end with a comment.  The comment starts
with a ";" (semicolon).



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# File 'lib/dns/zone.rb', line 36

def self.load(string)
  # get entries
  entries = self.extract_entries(string)

  instance = self.new

  options = {}
  entries.each do |entry|
    if entry =~ /\$(ORIGIN|TTL)\s+(.+)/
      instance.ttl    = $2 if $1 == 'TTL'
      instance.origin = $2 if $1 == 'ORIGIN'
      next
    end

    if entry =~ DNS::Zone::RR::REGEX_RR
      rec = DNS::Zone::RR.load(entry, options)
      next unless rec
      instance.records << rec
      options[:last_label] = rec.label
    end

  end

  # read in special statments like $TTL and $ORIGIN
  # parse each RR and create a Ruby object for it
  return instance
end

Instance Method Details

#dump ⇒ Object 



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# File 'lib/dns/zone.rb', line 18

def dump
  content = []
  @records.each do |rr|
    content << rr.dump
  end

  content.join("\n") << "\n"
end