Class: Zonefile

Inherits:
Object
  • Object
show all
Defined in:
lib/zonefile/zonefile.rb

Overview

Ruby Zonefile - Parse and manipulate DNS Zone Files.

Description

This class can read, manipulate and create DNS zone files. It supports A, AAAA, MX, NS, SOA, TXT, CNAME, PTR and SRV records. The data can be accessed by the instance method of the same name. All except SOA return an array of hashes containing the named data. SOA directly returns the hash since there can only be one SOA information.

The following hash keys are returned per record type:

  • SOA

    - :ttl, :primary, :email, :serial, :refresh, :retry, :expire, :minimumTTL

  • A

    - :name, :ttl, :class, :host

  • MX

    - :name, :ttl, :class, :pri, :host

  • NS

    - :name, :ttl, :class, :host

  • CNAME

    - :name, :ttl, :class, :host

  • TXT

    - :name, :ttl, :class, :text

  • A4 (AAAA)

    - :name, :ttl, :class, :host

  • PTR

    - :name, :ttl, :class, :host

  • SRV

    - :name, :ttl, :class, :pri, :weight, :port, :host

  • DS

    - :name, :ttl, :class, :key_tag, :algorithm, :digest_type, :digest

  • DNSKEY

    - :name, :ttl, :class, :flag, :protocol, :algorithm, :public_key

  • RRSIG

    - :name, :ttl, :class, :type_covered, :algorithm, :labels, :original_ttl,
  :expiration, :inception, :key_tag, :signer, :signature

  • NSEC

    - :name, :ttl, :class, :next, :types

  • NSEC3

    - :name, :ttl, :class, :algorithm, :flags, :iterations, :salt, :next, :types

  • NSEC3PARAM

    - :name, :ttl, :class, :algorithm, :flags, :iterations, :salt

  • NAPTR

    - :name, :ttl, :class, :order, :preference, :flags, :service, :regexp, :replacement

Examples

Read a Zonefile

zf = Zonefile.from_file('/path/to/zonefile.db')

# Display MX-Records
zf.mx.each do |mx_record|
   puts "Mail Exchagne with priority: #{mx_record[:pri]} --> #{mx_record[:host]}"
end

# Show SOA TTL
puts "Record Time To Live: #{zf.soa[:ttl]}"

# Show A-Records
zf.a.each do |a_record|
   puts "#{a_record[:name]} --> #{a_record[:host]}"
end

Manipulate a Zonefile

zf = Zonefile.from_file('/path/to/zonefile.db')

# Change TTL and add an A-Record

zf.soa[:ttl] = '123123'	# Change the SOA ttl
zf.a << { :class => 'IN', :name => 'www', :host => '192.168.100.1', :ttl => 3600 }  # add A-Record

# Setting PTR records (deleting existing ones)

zf.ptr = [ { :class => 'IN', :name=>'1.100.168.192.in-addr.arpa', :host => 'my.host.com' },
           { :class => 'IN', :name=>'2.100.168.192.in-addr.arpa', :host => 'me.host.com' } ]

# Increase Serial Number
zf.new_serial

# Print new zonefile
puts "New Zonefile: \n#{zf.output}"

Name attribute magic

Since 1.04 the :name attribute is preserved and returned as defined in a previous record if a zonefile entry omits it. This should be the expected behavior for most users. You can switch this off globally by calling Zonefile.preserve_name(false)

Authors

Martin Boese, based on Simon Flack Perl library DNS::ZoneParse

Andy Newton, patch to support various additional records

Constant Summary collapse

RECORDS = 
%w{ mx a a4 ns cname txt ptr srv soa ds dnskey rrsig nsec nsec3 nsec3param naptr }
@@preserve_name = 
true

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(zonefile = '', file_name = nil, origin = nil) ⇒ Zonefile

create a new zonefile object by passing the content of the zonefile



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# File 'lib/zonefile/zonefile.rb', line 155

def initialize(zonefile = '', file_name= nil, origin= nil)
  @data = zonefile
  @filename = file_name
  @origin = origin || (file_name ? file_name.split('/').last : '')
 
  @records = {}
  @soa = {}
  RECORDS.each { |r| @records[r.intern] = [] }
  parse
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(m, *args) ⇒ Object 



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# File 'lib/zonefile/zonefile.rb', line 119

def method_missing(m, *args)
  mname = m.to_s.sub("=","")
  return super unless RECORDS.include?(mname)
  
  if m.to_s[-1].chr == '=' then
    @records[mname.intern] = args.first
    @records[mname.intern]
  else 
    @records[m]
  end
end

Instance Attribute Details

#data ⇒ Object (readonly)

Returns the value of attribute data.



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# File 'lib/zonefile/zonefile.rb', line 104

def data
  @data
end

#origin ⇒ Object (readonly)

global $ORIGIN option



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# File 'lib/zonefile/zonefile.rb', line 106

def origin
  @origin
end

#records ⇒ Object (readonly)

Returns the value of attribute records.



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# File 'lib/zonefile/zonefile.rb', line 102

def records
  @records
end

#soa ⇒ Object (readonly)

Returns the value of attribute soa.



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# File 'lib/zonefile/zonefile.rb', line 103

def soa
  @soa
end

#ttl ⇒ Object (readonly)

global $TTL option



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# File 'lib/zonefile/zonefile.rb', line 108

def ttl
  @ttl
end

Class Method Details

.from_file(file_name, origin = nil) ⇒ Object

Create a new object by reading the content of a file



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# File 'lib/zonefile/zonefile.rb', line 175

def self.from_file(file_name, origin = nil)
   Zonefile.new(File.read(file_name), file_name.split('/').last, origin)
end

.preserve_name(do_preserve_name) ⇒ Object

For compatibility: This can switches off copying of the :name from the previous record in a zonefile if found omitted. This was zonefile’s behavior in <= 1.03 .



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# File 'lib/zonefile/zonefile.rb', line 115

def self.preserve_name(do_preserve_name)
  @@preserve_name = do_preserve_name
end

.simplify(zf) ⇒ Object

Compact a zonefile content - removes empty lines, comments, converts tabs into spaces etc…



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# File 'lib/zonefile/zonefile.rb', line 134

def self.simplify(zf)
   # concatenate everything split over multiple lines in parentheses - remove ;-comments in block
   zf = zf.gsub(/(\([^\)]*?\))/) { |m| m.split(/\n/).map { |l| l.gsub(/\;.*$/, '') }.join("\n").gsub(/[\r\n]/, '').gsub( /[\(\)]/, '') }

   zf.split(/\n/).map do |line|
       r = line.gsub(/\t/, ' ')
       r = r.gsub(/\s+/, ' ')
       		# FIXME: this is ugly and not accurate, couldn't find proper regex:
       		#   Don't strip ';' if it's quoted. Happens a lot in TXT records.
       (0..(r.length - 1)).find_all { |i| r[i].chr == ';' }.each do |comment_idx|
          if !r[(comment_idx+1)..-1].index(/['"]/) then
             r = r[0..(comment_idx-1)]
             break
          end
       end
       r
   end.delete_if { |line| line.empty? || line[0].chr == ';'}.join("\n")
end

Instance Method Details

#add_record(type, data = {}) ⇒ Object 



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# File 'lib/zonefile/zonefile.rb', line 179

def add_record(type, data= {})
   if @@preserve_name then
     @lastname = data[:name] if data[:name].to_s != ''
     data[:name] = @lastname if data[:name].to_s == ''
   end
   @records[type.downcase.intern] << data
end

#empty? ⇒ Boolean

True if no records (except sao) is defined in this file

Returns:

  • (Boolean) 


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# File 'lib/zonefile/zonefile.rb', line 167

def empty?
  RECORDS.each do |r|
     return false unless @records[r.intern].empty?
  end
  true
end

#new_serial ⇒ Object

Generates a new serial number in the format of YYYYMMDDII if possible



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# File 'lib/zonefile/zonefile.rb', line 188

def new_serial
  base = "%04d%02d%02d" % [Time.now.year, Time.now.month, Time.now.day ]

  if ((@soa[:serial].to_i / 100) > base.to_i) then
      ns = @soa[:serial].to_i + 1
      @soa[:serial] = ns.to_s
      return ns.to_s
  end
  
  ii = 0
  while (("#{base}%02d" % ii).to_i <= @soa[:serial].to_i) do
   ii += 1
  end
  @soa[:serial] = "#{base}%02d" % ii   
end

#output ⇒ Object

Build a new nicely formatted Zonefile



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# File 'lib/zonefile/zonefile.rb', line 370

def output
   out =<<-ENDH
;
;  Database file #{@filename || 'unknown'} for #{@origin || 'unknown'} zone.
;	Zone version: #{self.soa[:serial]}
;
#{self.soa[:origin]}		#{self.soa[:ttl]} IN  SOA  #{self.soa[:primary]} #{self.soa[:email]} (
			#{self.soa[:serial]}	; serial number
			#{self.soa[:refresh]}	; refresh
			#{self.soa[:retry]}	; retry
			#{self.soa[:expire]}	; expire
			#{self.soa[:minimumTTL]}	; minimum TTL
			)

#{@origin ? "$ORIGIN #{@origin}" : ''}
#{@ttl ? "$TTL #{@ttl}" : ''}
			
; Zone NS Records
ENDH
  self.ns.each do |ns|
    out <<  "#{ns[:name]}	#{ns[:ttl]}	#{ns[:class]}	NS	#{ns[:host]}\n"
  end
  out << "\n; Zone MX Records\n" unless self.mx.empty?
  self.mx.each do |mx|
    out << "#{mx[:name]}	#{mx[:ttl]}	#{mx[:class]}	MX	#{mx[:pri]} #{mx[:host]}\n"
  end
  
  out << "\n; Zone A Records\n" unless self.a.empty?
  self.a.each do |a|
       out <<  "#{a[:name]}	#{a[:ttl]}	#{a[:class]}	A	#{a[:host]}\n"
  end   

  out << "\n; Zone CNAME Records\n" unless self.cname.empty?
  self.cname.each do |cn|
    out << "#{cn[:name]}	#{cn[:ttl]}	#{cn[:class]}	CNAME	#{cn[:host]}\n"
  end  

  out << "\n; Zone AAAA Records\n" unless self.a4.empty?
  self.a4.each do |a4|
    out << "#{a4[:name]}	#{a4[:ttl]}	#{a4[:class]}	AAAA	#{a4[:host]}\n"
  end

  out << "\n; Zone TXT Records\n" unless self.txt.empty?
  self.txt.each do |tx|
    out << "#{tx[:name]}	#{tx[:ttl]}	#{tx[:class]}	TXT	#{tx[:text]}\n"
  end

  out << "\n; Zone SRV Records\n" unless self.srv.empty?
  self.srv.each do |srv|
    out << "#{srv[:name]}	#{srv[:ttl]}	#{srv[:class]}	SRV	#{srv[:pri]} #{srv[:weight]} #{srv[:port]}	#{srv[:host]}\n"
  end
  
  out << "\n; Zone PTR Records\n" unless self.ptr.empty?
  self.ptr.each do |ptr|
    out << "#{ptr[:name]}	#{ptr[:ttl]}	#{ptr[:class]}	PTR	#{ptr[:host]}\n"
  end

  out << "\n; Zone DS Records\n" unless self.ds.empty?
  self.ds.each do |ds|
    out << "#{ds[:name]} #{ds[:ttl]} #{ds[:class]} DS #{ds[:key_tag]} #{ds[:algorithm]} #{ds[:digest_type]} #{ds[:digest]}\n"
  end

  out << "\n; Zone NSEC Records\n" unless self.ds.empty?
  self.nsec.each do |nsec|
    out << "#{nsec[:name]} #{nsec[:ttl]} #{nsec[:class]} NSEC #{nsec[:next]} #{nsec[:types]}\n"
  end

  out << "\n; Zone NSEC3 Records\n" unless self.ds.empty?
  self.nsec3.each do |nsec3|
    out << "#{nsec3[:name]} #{nsec3[:ttl]} #{nsec3[:class]} NSEC3 #{nsec3[:algorithm]} #{nsec3[:flags]} #{nsec3[:iterations]} #{nsec3[:salt]} #{nsec3[:next]} #{nsec3[:types]}\n"
  end

  out << "\n; Zone NSEC3PARAM Records\n" unless self.ds.empty?
  self.nsec3param.each do |nsec3param|
    out << "#{nsec3param[:name]} #{nsec3param[:ttl]} #{nsec3param[:class]} NSEC3PARAM #{nsec3param[:algorithm]} #{nsec3param[:flags]} #{nsec3param[:iterations]} #{nsec3param[:salt]}\n"
  end

  out << "\n; Zone DNSKEY Records\n" unless self.ds.empty?
  self.dnskey.each do |dnskey|
    out << "#{dnskey[:name]} #{dnskey[:ttl]} #{dnskey[:class]} DNSKEY #{dnskey[:flag]} #{dnskey[:protocol]} #{dnskey[:algorithm]} #{dnskey[:public_key]}\n"
  end

  out << "\n; Zone RRSIG Records\n" unless self.ds.empty?
  self.rrsig.each do |rrsig|
    out << "#{rrsig[:name]} #{rrsig[:ttl]} #{rrsig[:class]} RRSIG #{rrsig[:type_covered]} #{rrsig[:algorithm]} #{rrsig[:labels]} #{rrsig[:original_ttl]} #{rrsig[:expiration]} #{rrsig[:inception]} #{rrsig[:key_tag]} #{rrsig[:signer]} #{rrsig[:signature]}\n"
  end

  out << "\n; Zone NAPTR Records\n" unless self.ds.empty?
  self.naptr.each do |naptr|
    out << "#{naptr[:name]} #{naptr[:ttl]} #{naptr[:class]} NAPTR #{naptr[:order]} #{naptr[:preference]} #{naptr[:flags]} #{naptr[:service]} #{naptr[:regexp]} #{naptr[:replacement]}\n"
  end

  out
end

#parse ⇒ Object 



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# File 'lib/zonefile/zonefile.rb', line 361

def parse
   Zonefile.simplify(@data).each_line do |line|
       parse_line(line)      
   end
end

#parse_line(line) ⇒ Object 



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# File 'lib/zonefile/zonefile.rb', line 204

def parse_line(line)
   valid_name = /[\@a-z_\-\.0-9\*]+/i
   valid_ip6  = /[\@a-z_\-\.0-9\*:]+/i
   rr_class   = /\b(?:IN|HS|CH)\b/i
   rr_type    = /\b(?:NS|A|CNAME)\b/i
   rr_ttl     = /(?:\d+[wdhms]?)+/i
   ttl_cls    = Regexp.new("(?:(#{rr_ttl})\s)?(?:(#{rr_class})\s)?")
   base64     = /([\s\w\+\/]*=*)/i
   hexadeimal = /([\sA-F0-9]*)/i
   quoted     = /(\"[^\"]*\")/i

   data = {}
   if line =~ /^\$ORIGIN\s*(#{valid_name})/ix then
       @origin = $1
   elsif line =~ /^(#{valid_name})? \s*
                #{ttl_cls}
                (#{rr_type}) \s
                (#{valid_name})
              /ix then
             (name, ttl, dclass, type, host) = [$1, $2, $3, $4, $5]
            add_record($4, :name => $1, :ttl => $2, :class => $3, :host => $5)
   elsif line=~/^(#{valid_name})? \s*
               #{ttl_cls}
               AAAA \s
               (#{valid_ip6})               
               /x then
             add_record('a4', :name => $1, :ttl => $2, :class => $3, :host => $4)
   elsif line=~/^(#{valid_name})? \s*
                #{ttl_cls}
                MX \s
                (\d+) \s
                (#{valid_name})
              /ix then
              add_record('mx', :name => $1, :ttl => $2, :class => $3, :pri => $4.to_i, :host => $5)
   elsif line=~/^(#{valid_name})? \s*
                #{ttl_cls}
                SRV \s
                (\d+) \s
                (\d+) \s
                (\d+) \s
                (#{valid_name})
              /ix
       add_record('srv', :name => $1, :ttl => $2, :class => $3, :pri => $4, :weight => $5,
                         :port => $6, :host => $7)
   elsif line=~/^(#{valid_name})? \s*
               #{ttl_cls}
               DS \s
               (\d+) \s
               (\w+) \s
               (\d+) \s
               #{hexadeimal}
               /ix
       add_record( 'ds', :name => $1, :ttl => $2, :class => $3, :key_tag => $4.to_i, :algorithm => $5,
                   :digest_type => $6.to_i, :digest => $7.gsub( /\s/,'') )
   elsif line=~/^(#{valid_name})? \s*
               #{ttl_cls}
               NSEC \s
               (#{valid_name}) \s
               ([\s\w]*)
               /ix
     add_record( 'nsec', :name => $1, :ttl => $2, :class => $3, :next => $4, :types => $5.strip )
   elsif line=~/^(#{valid_name})? \s*
               #{ttl_cls}
               NSEC3 \s
               (\d+) \s
               (\d+) \s
               (\d+) \s
               (-|[A-F0-9]*) \s
               ([A-Z2-7=]*) \s
               ([\s\w]*)
               /ix
     add_record( 'nsec3', :name => $1, :ttl => $2, :class => $3, :algorithm => $4, :flags => $5,
                  :iterations => $6, :salt => $7, :next => $8.strip, :types => $9.strip )
   elsif line=~/^(#{valid_name})? \s*
               #{ttl_cls}
               NSEC3PARAM \s
               (\d+) \s
               (\d+) \s
               (\d+) \s
               (-|[A-F0-9]*)
               /ix
     add_record( 'nsec3param', :name => $1, :ttl => $2, :class => $3, :algorithm => $4, :flags => $5,
                 :iterations => $6, :salt => $7 )
   elsif line=~/^(#{valid_name})? \s*
               #{ttl_cls}
               DNSKEY \s
               (\d+) \s
               (\d+) \s
               (\w+) \s
               #{base64}
               /ix
     add_record( 'dnskey', :name => $1, :ttl => $2, :class => $3, :flag => $4.to_i, :protocol => $5.to_i,
                 :algorithm => $6, :public_key => $7.gsub( /\s/,'') )
   elsif line=~/^(#{valid_name})? \s*
               #{ttl_cls}
               RRSIG \s
               (\w+) \s
               (\w+) \s
               (\d+) \s
               (\d+) \s
               (\d+) \s
               (\d+) \s
               (\d+) \s
               (#{valid_name}) \s
               #{base64}
               /ix
     add_record( 'rrsig', :name => $1, :ttl => $2, :class => $3, :type_covered => $4, :algorithm => $5,
                 :labels => $6.to_i, :original_ttl => $7.to_i, :expiration => $8.to_i, :inception => $9.to_i,
                 :key_tag => $10.to_i, :signer => $11, :signature => $12.gsub( /\s/,'')  )
   elsif line=~/^(#{valid_name})? \s*
               #{ttl_cls}
               NAPTR \s
               (\d+) \s
               (\d+) \s
               #{quoted} \s
               #{quoted} \s
               #{quoted} \s
               (#{valid_name})
               /ix
     add_record( 'naptr', :name => $1, :ttl => $2, :class => $3, :order => $4.to_i, :preference => $5.to_i,
                 :flags => $6, :service => $7, :regexp => $8, :replacement => $9 )
   elsif line=~/^(#{valid_name}) \s+
                #{ttl_cls}
                SOA \s+
                (#{valid_name}) \s+
                (#{valid_name}) \s*
                \s*
                    (#{rr_ttl}) \s+
                    (#{rr_ttl}) \s+
                    (#{rr_ttl}) \s+
                    (#{rr_ttl}) \s+
                    (#{rr_ttl}) \s*
              /ix
           ttl = @soa[:ttl] || $2 || ''
           @soa[:origin] = $1
           @soa[:ttl] = ttl
           @soa[:primary] = $4
           @soa[:email] = $5
           @soa[:serial] = $6
           @soa[:refresh] = $7
           @soa[:retry] = $8
           @soa[:expire] = $9
           @soa[:minimumTTL] = $10

   elsif line=~ /^(#{valid_name})? \s*
               #{ttl_cls}
               PTR \s+
               (#{valid_name})
              /ix
           add_record('ptr', :name => $1, :class => $3, :ttl => $2, :host => $4)
   elsif line =~ /^(#{valid_name})? \s* #{ttl_cls} TXT \s+ (.*)$/ix
            add_record('txt', :name => $1, :ttl => $2, :class => $3, :text => $4.strip)
   elsif line =~ /\$TTL\s+(#{rr_ttl})/i 
           @ttl = $1
   end
end