Class: Dnsruby::ZoneTransfer
- Inherits:
-
Object
- Object
- Dnsruby::ZoneTransfer
- Defined in:
- lib/Dnsruby/zone_transfer.rb
Overview
This class performs zone transfers as per RFC1034 (AXFR) and RFC1995 (IXFR).
Defined Under Namespace
Classes: Delta
Instance Attribute Summary collapse
-
#klass ⇒ Object
The class - defaults to IN.
-
#last_tsigstate ⇒ Object
readonly
Returns the tsigstate of the last transfer (nil if no TSIG signed transfer has occurred).
-
#port ⇒ Object
The port to connect to - defaults to 53.
-
#serial ⇒ Object
If using IXFR, this is the SOA serial number to start the incrementals from.
-
#server ⇒ Object
The nameserver to use for the zone transfer - defaults to system config.
-
#transfer_type ⇒ Object
What type of transfer to do (IXFR or AXFR) - defaults to AXFR.
-
#tsig ⇒ Object
The TSIG record used to sign the transfer.
Instance Method Summary collapse
-
#do_transfer(zone, server) ⇒ Object
:nodoc: all.
-
#initialize ⇒ ZoneTransfer
constructor
A new instance of ZoneTransfer.
-
#parseRR(rec) ⇒ Object
:nodoc: all.
-
#receive_message(socket) ⇒ Object
:nodoc: all.
-
#send_message(socket, msg) ⇒ Object
:nodoc: all.
-
#tcp_read(socket, len) ⇒ Object
:nodoc: all.
-
#transfer(zone) ⇒ Object
Perform a zone transfer (RFC1995) If an IXFR query is unsuccessful, then AXFR is tried (and @transfer_type is set to AXFR) TCP is used as the only transport.
Constructor Details
#initialize ⇒ ZoneTransfer
Returns a new instance of ZoneTransfer.
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# File 'lib/Dnsruby/zone_transfer.rb', line 30 def initialize @server=Config.new.nameserver[0] @transfer_type = Types.AXFR @klass=Classes.IN @port=53 @serial=0 @tsig = nil @axfr = nil end |
Instance Attribute Details
#klass ⇒ Object
The class - defaults to IN
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# File 'lib/Dnsruby/zone_transfer.rb', line 9 def klass @klass end |
#last_tsigstate ⇒ Object (readonly)
Returns the tsigstate of the last transfer (nil if no TSIG signed transfer has occurred)
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# File 'lib/Dnsruby/zone_transfer.rb', line 17 def last_tsigstate @last_tsigstate end |
#port ⇒ Object
The port to connect to - defaults to 53
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# File 'lib/Dnsruby/zone_transfer.rb', line 11 def port @port end |
#serial ⇒ Object
If using IXFR, this is the SOA serial number to start the incrementals from
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# File 'lib/Dnsruby/zone_transfer.rb', line 13 def serial @serial end |
#server ⇒ Object
The nameserver to use for the zone transfer - defaults to system config
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# File 'lib/Dnsruby/zone_transfer.rb', line 5 def server @server end |
#transfer_type ⇒ Object
What type of transfer to do (IXFR or AXFR) - defaults to AXFR
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# File 'lib/Dnsruby/zone_transfer.rb', line 7 def transfer_type @transfer_type end |
#tsig ⇒ Object
The TSIG record used to sign the transfer
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# File 'lib/Dnsruby/zone_transfer.rb', line 15 def tsig @tsig end |
Instance Method Details
#do_transfer(zone, server) ⇒ Object
:nodoc: all
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# File 'lib/Dnsruby/zone_transfer.rb', line 87 def do_transfer(zone, server) #:nodoc: all @transfer_type = Types.new(@transfer_type) @state = :InitialSoa socket = TCPSocket.new(server, @port) begin # Send an initial query msg = Message.new(zone, @transfer_type, @klass) if @transfer_type == Types.IXFR rr = RR.create("#{zone} 0 IN SOA" + '0 0 %u 0 0 0 0' % @serial) msg.(rr) end (socket, msg) while (@state != :End) response = (socket) if (@state == :InitialSoa) rcode = response.header.rcode if (rcode != RCode.NOERROR) if (@transfer_type == Types.IXFR && rcode == RCode.NOTIMP) # IXFR didn't work - let's try AXFR TheLog.debug("IXFR DID NOT WORK (rcode = NOTIMP) - TRYING AXFR!!") @state = :InitialSoa @transfer_type=Types.AXFR # Send an initial AXFR query msg = Message.new(zone, @transfer_type, @klass) (socket, msg) next end raise ResolvError.new(rcode.string); end if (response.question[0].qtype != @transfer_type) raise ResolvError.new("invalid question section") end if (response.header.ancount == 0 && @transfer_type == Types.IXFR) TheLog.debug("IXFR DID NOT WORK (ancount = 0) - TRYING AXFR!!") # IXFR didn't work - let's try AXFR @transfer_type=Types.AXFR # Send an initial AXFR query @state = :InitialSoa msg = Message.new(zone, @transfer_type, @klass) (socket, msg) next end end response.each_answer { |rr| parseRR(rr) } if (@state == :End && response.tsigstate == :Intermediate) raise ResolvError.new("last message must be signed") end if (@state == :End && @tsig) if (response.tsigstate != :Verified) @last_tsigstate = :Failed raise ResolvError.new("Zone transfer not correctly signed") end @last_tsigstate = :Verified end end # This could return with an IXFR response, or an AXFR response. # If it fails completely, then try to send an AXFR query. # Once the query has been sent, then enter the main response loop. # Unless we know we're definitely AXFR, we should be prepared for either IXFR or AXFR # AXFR response : The first and the last RR of the response is the SOA record of the zone. # The whole zone is returned inbetween. # IXFR response : one or more difference sequences is returned. The list of difference # sequences is preceded and followed by a copy of the server's current # version of the SOA. # Each difference sequence represents one update to the zone (one SOA # serial change) consisting of deleted RRs and added RRs. The first RR # of the deleted RRs is the older SOA RR and the first RR of the added # RRs is the newer SOA RR. socket.close if (@axfr!=nil) return @axfr end return @ixfr rescue Exception => e socket.close raise e end end |
#parseRR(rec) ⇒ Object
:nodoc: all
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# File 'lib/Dnsruby/zone_transfer.rb', line 201 def parseRR(rec) #:nodoc: all name = rec.name type = rec.type delta = Delta.new case @state when :InitialSoa if (type != Types.SOA) raise ResolvError.new("missing initial SOA") end @initialsoa = rec # Remember the serial number in the initial SOA; we need it # to recognize the end of an IXFR. @end_serial = rec.serial if (@transfer_type == Types.IXFR && @end_serial <= @serial) TheLog.debug("zone up to date") @state = :End else @state = :FirstData end when :FirstData # If the transfer begins with 1 SOA, it's an AXFR. # If it begins with 2 SOAs, it's an IXFR. if (@transfer_type == Types.IXFR && type == Types.SOA && rec.serial == @serial) TheLog.debug("IXFR response - using IXFR") @rtype = Types.IXFR @ixfr = [] @state = :Ixfr_DelSoa else TheLog.debug("AXFR response - using AXFR") @rtype = Types.AXFR @axfr = [] @axfr << @initialsoa @state = :Axfr end parseRR(rec) # Restart... return when :Ixfr_DelSoa delta = Delta.new @ixfr.push(delta) delta.start = rec.serial delta.deletes << rec @state = :Ixfr_Del when :Ixfr_Del if (type == Types.SOA) @current_serial = rec.serial @state = :Ixfr_AddSoa parseRR(rec); # Restart... return; end delta = @ixfr[@ixfr.length - 1] delta.deletes << rec when :Ixfr_AddSoa delta = @ixfr[@ixfr.length - 1] delta.end = rec.serial delta.adds << rec @state = :Ixfr_Add when :Ixfr_Add if (type == Types.SOA) soa_serial = rec.serial if (soa_serial == @end_serial) @state = :End return elsif (soa_serial != @current_serial) raise ResolvError.new("IXFR out of sync: expected serial " + @current_serial + " , got " + soa_serial); else @state = :Ixfr_DelSoa parseRR(rec); # Restart... return; end end delta = @ixfr[@ixfr.length - 1] delta.adds << rec when :Axfr # Old BINDs sent cross class A records for non IN classes. if (type == Types.A && rec.klass() != @klass) else @axfr << rec if (type == Types.SOA) @state = :End end end when :End raise ResolvError.new("extra data in zone transfer") else raise ResolvError.new("invalid state for zone transfer") end end |
#receive_message(socket) ⇒ Object
:nodoc: all
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# File 'lib/Dnsruby/zone_transfer.rb', line 318 def (socket) #:nodoc: all buf = tcp_read(socket, 2) answersize = buf.unpack('n')[0] buf = tcp_read(socket, answersize) msg = Message.decode(buf) if (@tsig) if !@tsig.verify_envelope(msg, buf) TheLog.error("Bad signature on zone transfer - closing connection") raise ResolvError.new("Bad signature on zone transfer") end end return msg end |
#send_message(socket, msg) ⇒ Object
:nodoc: all
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# File 'lib/Dnsruby/zone_transfer.rb', line 299 def (socket, msg) #:nodoc: all if (@tsig) @tsig.apply(msg) @tsig = msg.tsig end query_packet = msg.encode lenmsg = [query_packet.length].pack('n') socket.send(lenmsg, 0) socket.send(query_packet, 0) end |
#tcp_read(socket, len) ⇒ Object
:nodoc: all
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# File 'lib/Dnsruby/zone_transfer.rb', line 310 def tcp_read(socket, len) #:nodoc: all buf="" while (buf.length < len) do buf += socket.recv(len-buf.length) end return buf end |
#transfer(zone) ⇒ Object
Perform a zone transfer (RFC1995) If an IXFR query is unsuccessful, then AXFR is tried (and @transfer_type is set to AXFR) TCP is used as the only transport
If AXFR is performed, then the zone will be returned as a set of records :
zt = Dnsruby::ZoneTransfer.new
zt.transfer_type = Dnsruby::Types.AXFR
zt.server = "ns0.validation-test-servers.nominet.org.uk"
zone = zt.transfer("validation-test-servers.nominet.org.uk")
soa = zone[0]
rec1 = zone[1]
print zone.to_s
If IXFR is performed, then the incrementals will be returned as a set of Deltas. Each Delta contains the start and end SOA serial number, as well as an array of adds and deletes that occurred between the start and end.
zt = Dnsruby::ZoneTransfer.new
zt.transfer_type = Dnsruby::Types.IXFR
zt.server = "ns0.validation-test-servers.nominet.org.uk"
zt.serial = 2007090401
deltas = zt.transfer("validation-test-servers.nominet.org.uk")
assert_equal("Should show up in transfer", deltas[0].adds[1].data)
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# File 'lib/Dnsruby/zone_transfer.rb', line 66 def transfer(zone) servers = @server if (servers.class == String) servers=[servers] end xfr = nil exception = nil servers.each do |server| begin server=Config.resolve_server(server) xfr = do_transfer(zone, server) break rescue Exception => exception end end if (xfr == nil && exception != nil) raise exception end return xfr end |