Class: Dnsruby::Recursor
- Inherits:
-
Object
- Object
- Dnsruby::Recursor
- Defined in:
- lib/dnsruby/recursor.rb
Overview
Dnsruby::Recursor - Perform recursive dns lookups
require 'Dnsruby'
rec = Dnsruby::Recursor.new()
answer = rec.recurse("rob.com.au")
This module uses a Dnsruby::Resolver to perform recursive queries.
AUTHOR
Rob Brown, [email protected] Alex Dalitz, [email protected]
SEE ALSO
Dnsruby::Resolver,
COPYRIGHT
Copyright © 2002, Rob Brown. All rights reserved. Portions Copyright © 2005, Olaf M Kolkman. Ruby version with caching and validation Copyright © 2008, AlexD (Nominet UK)
Example lookup process:
[root@box root]# dig +trace www.rob.com.au.
; <<>> DiG 9.2.0 <<>> +trace www.rob.com.au. ;; global options: printcmd . 507343 IN NS C.ROOT-SERVERS.NET. . 507343 IN NS D.ROOT-SERVERS.NET. . 507343 IN NS E.ROOT-SERVERS.NET. . 507343 IN NS F.ROOT-SERVERS.NET. . 507343 IN NS G.ROOT-SERVERS.NET. . 507343 IN NS H.ROOT-SERVERS.NET. . 507343 IN NS I.ROOT-SERVERS.NET. . 507343 IN NS J.ROOT-SERVERS.NET. . 507343 IN NS K.ROOT-SERVERS.NET. . 507343 IN NS L.ROOT-SERVERS.NET. . 507343 IN NS M.ROOT-SERVERS.NET. . 507343 IN NS A.ROOT-SERVERS.NET. . 507343 IN NS B.ROOT-SERVERS.NET. ;; Received 436 bytes from 127.0.0.1#53(127.0.0.1) in 9 ms
;;; But these should be hard coded as the hints
;;; Ask H.ROOT-SERVERS.NET gave:
au. 172800 IN NS NS2.BERKELEY.EDU. au. 172800 IN NS NS1.BERKELEY.EDU. au. 172800 IN NS NS.UU.NET. au. 172800 IN NS BOX2.AUNIC.NET. au. 172800 IN NS SEC1.APNIC.NET. au. 172800 IN NS SEC3.APNIC.NET. ;; Received 300 bytes from 128.63.2.53#53(H.ROOT-SERVERS.NET) in 322 ms
;;; A little closer than before
;;; Ask NS2.BERKELEY.EDU gave:
com.au. 259200 IN NS ns4.ausregistry.net. com.au. 259200 IN NS dns1.telstra.net. com.au. 259200 IN NS au2ld.CSIRO.au. com.au. 259200 IN NS audns01.syd.optus.net. com.au. 259200 IN NS ns.ripe.net. com.au. 259200 IN NS ns1.ausregistry.net. com.au. 259200 IN NS ns2.ausregistry.net. com.au. 259200 IN NS ns3.ausregistry.net. com.au. 259200 IN NS ns3.melbourneit.com. ;; Received 387 bytes from 128.32.206.12#53(NS2.BERKELEY.EDU) in 10312 ms
;;; A little closer than before
;;; Ask ns4.ausregistry.net gave:
com.au. 259200 IN NS ns1.ausregistry.net. com.au. 259200 IN NS ns2.ausregistry.net. com.au. 259200 IN NS ns3.ausregistry.net. com.au. 259200 IN NS ns4.ausregistry.net. com.au. 259200 IN NS ns3.melbourneit.com. com.au. 259200 IN NS dns1.telstra.net. com.au. 259200 IN NS au2ld.CSIRO.au. com.au. 259200 IN NS ns.ripe.net. com.au. 259200 IN NS audns01.syd.optus.net. ;; Received 259 bytes from 137.39.1.3#53(ns4.ausregistry.net) in 606 ms
;;; Uh... yeah... I already knew this
;;; from what NS2.BERKELEY.EDU told me.
;;; ns4.ausregistry.net must have brain damage
;;; Ask ns1.ausregistry.net gave:
rob.com.au. 86400 IN NS sy-dns02.tmns.net.au. rob.com.au. 86400 IN NS sy-dns01.tmns.net.au. ;; Received 87 bytes from 203.18.56.41#53(ns1.ausregistry.net) in 372 ms
;;; Ah, much better. Something more useful.
;;; Ask sy-dns02.tmns.net.au gave:
www.rob.com.au. 7200 IN A 139.134.5.123 rob.com.au. 7200 IN NS sy-dns01.tmns.net.au. rob.com.au. 7200 IN NS sy-dns02.tmns.net.au. ;; Received 135 bytes from 139.134.2.18#53(sy-dns02.tmns.net.au) in 525 ms
;;; FINALLY, THE ANSWER!
Now,DNSSEC validation is performed (unless disabled).
Defined Under Namespace
Classes: AddressCache
Constant Summary collapse
- @@mutex =
For guarding access to shared caches.
Mutex.new
- @@hints =
:nodoc: all
nil
Hash.new
- @@zones_cache =
nil
- @@nameservers =
nil
Instance Attribute Summary collapse
-
#callback ⇒ Object
Returns the value of attribute callback.
-
#dnssec ⇒ Object
Returns the value of attribute dnssec.
-
#hints ⇒ Object
Returns the value of attribute hints.
-
#ipv6_ok ⇒ Object
Returns the value of attribute ipv6_ok.
-
#nameservers ⇒ Object
Returns the value of attribute nameservers.
-
#recurse ⇒ Object
Returns the value of attribute recurse.
-
#resolver ⇒ Object
The resolver to use for the queries.
Class Method Summary collapse
- .add_to_hints(hints, rr) ⇒ Object
- .clear_caches(resolver = Resolver.new) ⇒ Object
- .set_hints(hints, resolver) ⇒ Object
Instance Method Summary collapse
-
#_dorecursion(name, type, klass, known_zone, known_authorities, depth, no_validation) ⇒ Object
:nodoc:.
-
#get_closest_known_zone_authorities_for(name) ⇒ Object
:nodoc:.
-
#get_closest_known_zone_for(n) ⇒ Object
:nodoc:.
-
#initialize(res = nil) ⇒ Recursor
constructor
A new instance of Recursor.
- #prune_rrsets_to_rfc5452(packet, zone) ⇒ Object
-
#query(name, type = Types.A, klass = Classes.IN, no_validation = false) ⇒ Object
This method is much like the normal query() method except it disables the recurse flag in the packet and explicitly performs the recursion.
-
#query_no_validation_or_recursion(name, type = Types.A, klass = Classes.IN) ⇒ Object
:nodoc: all.
- #recursion_callback ⇒ Object
-
#recursion_callback=(sub) ⇒ Object
This method takes a code reference, which is then invoked each time a packet is received during the recursive lookup.
Constructor Details
#initialize(res = nil) ⇒ Recursor
Returns a new instance of Recursor.
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# File 'lib/dnsruby/recursor.rb', line 172 def initialize(res = nil) if (res) @resolver = res else if (defined?@@nameservers && @@nameservers.length > 0) @resolver = Resolver.new({:nameserver => @@nameservers}) else @resolver = Resolver.new end end @resolver.dnssec = @dnssec @ipv6_ok = false end |
Instance Attribute Details
#callback ⇒ Object
Returns the value of attribute callback.
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# File 'lib/dnsruby/recursor.rb', line 155 def callback @callback end |
#dnssec ⇒ Object
Returns the value of attribute dnssec.
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# File 'lib/dnsruby/recursor.rb', line 156 def dnssec @dnssec end |
#hints ⇒ Object
Returns the value of attribute hints.
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# File 'lib/dnsruby/recursor.rb', line 156 def hints @hints end |
#ipv6_ok ⇒ Object
Returns the value of attribute ipv6_ok.
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# File 'lib/dnsruby/recursor.rb', line 155 def ipv6_ok @ipv6_ok end |
#nameservers ⇒ Object
Returns the value of attribute nameservers.
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# File 'lib/dnsruby/recursor.rb', line 155 def nameservers @nameservers end |
#recurse ⇒ Object
Returns the value of attribute recurse.
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# File 'lib/dnsruby/recursor.rb', line 155 def recurse @recurse end |
#resolver ⇒ Object
The resolver to use for the queries
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# File 'lib/dnsruby/recursor.rb', line 158 def resolver @resolver end |
Class Method Details
.add_to_hints(hints, rr) ⇒ Object
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# File 'lib/dnsruby/recursor.rb', line 336 def Recursor.add_to_hints(hints, rr) server = rr.name.to_s.downcase server.sub!(/\.$/,"") if (server) if ( rr.type == Types::A) # print ";; ADDITIONAL HELP: $server -> [".$rr->rdatastr."]\n" if $self->{'debug'}; if (hints[server]!=nil) TheLog.debug(";; STORING IP: #{server} IN A "+rr.address.to_s+"\n") hints[server].push([rr.address.to_s, rr.ttl]) end end if ( rr.type == Types::AAAA) # print ";; ADDITIONAL HELP: $server -> [".$rr->rdatastr."]\n" if $self->{'debug'}; if (hints[server]) TheLog.debug(";; STORING IP6: #{server} IN AAAA "+rr.address.to_s+"\n") hints[server].push([rr.address.to_s, rr.ttl]) end end end end |
.clear_caches(resolver = Resolver.new) ⇒ Object
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# File 'lib/dnsruby/recursor.rb', line 381 def Recursor.clear_caches(resolver = Resolver.new) resolver.dnssec = @dnssec Recursor.set_hints(Hash.new, resolver) @@zones_cache = Hash.new # key zone_name, values Hash of servers and AddressCaches @@zones_cache["."] = @@hints @@authority_cache = Hash.new end |
.set_hints(hints, resolver) ⇒ Object
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# File 'lib/dnsruby/recursor.rb', line 200 def Recursor.set_hints(hints, resolver) TheLog.debug(";; hints(#{hints.inspect})\n") @resolver = resolver if (resolver.single_resolvers.length == 0) resolver = Resolver.new() resolver.dnssec = @dnssec end if (hints && hints.length > 0) resolver.nameservers=hints if (String === hints) hints = [hints] end hints.each {|hint| @@hints = Hash.new @@hints[hint]=hint } end if (!hints && @@nameservers) @@hints=(@@nameservers) else @@nameservers=(hints) @@hints = hints end TheLog.debug(";; verifying (root) zone...\n") # bind always asks one of the hint servers # for who it thinks is authoritative for # the (root) zone as a sanity check. # Nice idea. # if (!@@hints || @@hints.length == 0) resolver.recurse = true packet=resolver.query_no_validation_or_recursion(".", "NS", "IN") hints = Hash.new if (packet) if (ans = packet.answer) ans.each do |rr| if (rr.name.to_s =~ /^\.?$/ and rr.type == Types::NS) # Found root authority server = rr.nsdname.to_s.downcase server.sub!(/\.$/,"") TheLog.debug(";; FOUND HINT: #{server}\n") hints[server] = AddressCache.new end end if ((packet.additional.length == 0) || ((packet.additional.length == 1) && (packet.additional()[0].type == Types.OPT))) # Some resolvers (e.g. 8.8.8.8) do not send an additional section - # need to make explicit queries for these :( # Probably best to limit the number of outstanding queries - extremely bursty behaviour otherwise # What happens if we select only name q = Queue.new hints.keys.each {|server| # Query for the server address and add it to hints. ['A', 'AAAA'].each {|type| msg = Message.new msg.do_caching = @do_caching msg.header.rd = false msg.do_validation = false msg.add_question(server, type, 'IN') if (@dnssec) msg.header.cd = true # We do our own validation by default end resolver.send_async(msg, q) } } (hints.length * 2).times { _id, result, _error = q.pop if (result) result.answer.each {|rr| TheLog.debug(";; NS address: " + rr.inspect+"\n") add_to_hints(hints, rr) } end } else packet.additional.each do |rr| TheLog.debug(";; ADDITIONAL: "+rr.inspect+"\n") add_to_hints(hints, rr) end end end # foreach my $server (keys %hints) { hints.keys.each do |server| if (!hints[server] || hints[server].length == 0) # Wipe the servers without lookups hints.delete(server) end end @@hints = hints else @@hints = {} end if (@@hints.size > 0) TheLog.info(";; USING THE FOLLOWING HINT IPS:\n") @@hints.values.each do |ips| ips.each do |server| TheLog.info(";; #{server}\n") end end else raise ResolvError.new( "Server ["+(@@nameservers)[0].to_s+".] did not give answers") end # Disable recursion flag. resolver.recurse = false # end # return $self->nameservers( map { @{ $_ } } values %{ $self->{'hints'} } ); if (Array === @@hints) temp = [] @@hints.each {|hint| temp.push(hint) } @@hints = Hash.new count = 0 temp.each {|hint| print "Adding hint : #{temp[count]}\n" @@hints[count] = temp[count] count += 1 } end if (String === @@hints) temp = @@hints @@hints = Hash.new @@hints[0] = temp end # @@nameservers = @@hints.values @@nameservers=[] @@hints.each {|key, value| @@nameservers.push(key) } return @@nameservers end |
Instance Method Details
#_dorecursion(name, type, klass, known_zone, known_authorities, depth, no_validation) ⇒ Object
:nodoc:
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# File 'lib/dnsruby/recursor.rb', line 495 def _dorecursion(name, type, klass, known_zone, , depth, no_validation) # :nodoc: if ( depth > 255 ) TheLog.debug(";; _dorecursion() Recursion too deep, aborting...\n") @errorstring="Recursion too deep, aborted" return nil end known_zone.sub!(/\.*$/, ".") ns = [] # Array of AddressCaches (was array of array of addresses) @@mutex.synchronize{ # Get IPs from authorities .keys.each do |ns_rec| if ([ns_rec] != nil && [ns_rec] != [] ) @@authority_cache[ns_rec] = [ns_rec] ns.push(@@authority_cache[ns_rec]) elsif (@@authority_cache[ns_rec]!=nil && @@authority_cache[ns_rec]!=[]) [ns_rec] = @@authority_cache[ns_rec] ns.push(@@authority_cache[ns_rec]) end end if (ns.length == 0) found_auth = 0 TheLog.debug(";; _dorecursion() Failed to extract nameserver IPs:") TheLog.debug(.inspect + @@authority_cache.inspect) .keys.each do |ns_rec| if ([ns_rec]==nil || [ns_rec]==[]) TheLog.debug(";; _dorecursion() Manual lookup for authority [#{ns_rec}]") auth_packet=nil ans=[] # Don't query for V6 if its not there. # Do this in parallel ip_mutex = Mutex.new ip6_thread = Thread.start { if ( @ipv6_ok) auth_packet = _dorecursion(ns_rec,"AAAA", klass, # packet ".", # known_zone @@hints, # known_authorities depth+1); # depth ip_mutex.synchronize { ans.push(auth_packet.answer) if auth_packet } end } ip4_thread = Thread.start { auth_packet = _dorecursion(ns_rec,"A",klass, # packet ".", # known_zone @@hints, # known_authorities depth+1); # depth ip_mutex.synchronize { ans.push(auth_packet.answer ) if auth_packet } } ip6_thread.join ip4_thread.join if ( ans.length > 0 ) TheLog.debug(";; _dorecursion() Answers found for [#{ns_rec}]") # foreach my $rr (@ans) { ans.each do |rr_arr| rr_arr.each do |rr| TheLog.debug(";; RR:" + rr.inspect + "") if (rr.type == Types::CNAME) # Follow CNAME server = rr.name.to_s.downcase if (server) server.sub!(/\.*$/, ".") if (server == ns_rec) cname = rr.cname.downcase cname.sub!(/\.*$/, ".") TheLog.debug(";; _dorecursion() Following CNAME ns [#{ns_rec}] -> [#{cname}]") if (!([cname])) [cname] = AddressCache.new end .delete(ns_rec) next end end elsif (rr.type == Types::A || rr.type == Types::AAAA ) server = rr.name.to_s.downcase if (server) server.sub!(/\.*$/, ".") if ([server]!=nil) ip = rr.address.to_s TheLog.debug(";; _dorecursion() Found ns: #{server} IN A #{ip}") @@authority_cache[server] = [server] @@authority_cache[ns_rec].push([ip, rr.ttl]) found_auth+=1 next end end end TheLog.debug(";; _dorecursion() Ignoring useless answer: " + rr.inspect + "") end end else TheLog.debug(";; _dorecursion() Could not find A records for [#{ns_rec}]") end end end if (found_auth > 0) TheLog.debug(";; _dorecursion() Found #{found_auth} new NS authorities...") return _dorecursion( name, type, klass, known_zone, , depth+1) end TheLog.debug(";; _dorecursion() No authority information could be obtained.") return nil end } # Cut the deck of IPs in a random place. TheLog.debug(";; _dorecursion() cutting deck of (" + ns.length.to_s + ") authorities...") splitpos = rand(ns.length) start = ns[0, splitpos] endarr = ns[splitpos, ns.length - splitpos] ns = endarr + start nameservers = [] ns.each do |nss| nss.each {|n| nameservers.push(n.to_s) } end resolver = Resolver.new({:nameserver=>nameservers}) resolver.dnssec = @dnssec resolver.recurse = false servers = [] resolver.single_resolvers.each {|s| servers.push(s.server) } resolver.retry_delay = nameservers.length begin # Should construct packet ourselves and clear RD bit query = Message.new(name, type, klass) query.header.rd = false query.do_validation = true query.do_caching = false query.do_validation = false if no_validation # print "Sending msg from resolver, dnssec = #{resolver.dnssec}, do_validation = #{query.do_validation}\n" packet = resolver.(query) # @TODO@ Now prune unrelated RRSets (RFC 5452 section 6) prune_rrsets_to_rfc5452(packet, known_zone) rescue ResolvTimeout, IOError # TheLog.debug(";; nameserver #{levelns.to_s} didn't respond") # next TheLog.debug("No response!") return nil end if (packet) # @TODO@ Check that the packet *is* actually authoritative!! if (@callback) @callback.call(packet) end of = nil TheLog.debug(";; _dorecursion() Response received from [" + @answerfrom.to_s + "]") status = packet.rcode = packet. if (status) if (status == "NXDOMAIN") # I guess NXDOMAIN is the best we'll ever get TheLog.debug(";; _dorecursion() returning NXDOMAIN") return packet elsif (packet.answer.length > 0) TheLog.debug(";; _dorecursion() Answers were found.") return packet elsif (packet.header.aa) TheLog.debug(";; _dorecursion() Authoritative answer found") return packet elsif (.length > 0) auth = Hash.new # foreach my $rr (@authority) { .each do |rr| if (rr.type.to_s =~ /^(NS|SOA)$/) server = (rr.type == Types::NS ? rr.nsdname : rr.mname).to_s.downcase server.sub!(/\.*$/, ".") of = rr.name.to_s.downcase of.sub!(/\.*$/, ".") TheLog.debug(";; _dorecursion() Received authority [#{of}] [" + rr.type().to_s + "] [#{server}]") if (of.length <= known_zone.length) TheLog.debug(";; _dorecursion() Deadbeat name server did not provide new information.") next elsif (of =~ /#{known_zone}/) TheLog.debug(";; _dorecursion() FOUND closer authority for [#{of}] at [#{server}].") auth[server] ||= AddressCache.new #[] @TODO@ If there is no additional record for this, then we want to use the authority! if (rr.type == Types.NS) if ((packet.additional.rrset(rr.nsdname, Types::A).length == 0) && (packet.additional.rrset(rr.nsdname, Types::AAAA).length == 0)) auth[server].push([rr.nsdname, rr.ttl]) end end else TheLog.debug(";; _dorecursion() Confused name server [" + @answerfrom + "] thinks [#{of}] is closer than [#{known_zone}]?") return nil end else TheLog.debug(";; _dorecursion() Ignoring NON NS entry found in authority section: " + rr.inspect) end end # foreach my $rr ($packet->additional) packet.additional.each do |rr| if (rr.type == Types::CNAME) # Store this CNAME into %auth too server = rr.name.to_s.downcase if (server) server.sub!(/\.*$/, ".") if (auth[server]!=nil && auth[server].length > 0) cname = rr.cname.to_s.downcase cname.sub!(/\.*$/, ".") TheLog.debug(";; _dorecursion() FOUND CNAME authority: " + rr.string) auth[cname] ||= AddressCache.new # [] auth[server] = auth[cname] next end end elsif (rr.type == Types::A || rr.type == Types::AAAA) server = rr.name.to_s.downcase if (server) server.sub!(/\.*$/, ".") if (auth[server]!=nil) if (rr.type == Types::A) TheLog.debug(";; _dorecursion() STORING: #{server} IN A " + rr.address.to_s) end if (rr.type == Types::AAAA) TheLog.debug(";; _dorecursion() STORING: #{server} IN AAAA " + rr.address.to_s) end auth[server].push([rr.address.to_s, rr.ttl]) next end end end TheLog.debug(";; _dorecursion() Ignoring useless: " + rr.inspect) end if (of =~ /#{known_zone}/) # print "Adding #{of} with :\n#{auth}\nto zones_cache\n" @@mutex.synchronize{ @@zones_cache[of]=auth } return _dorecursion( name, type, klass, of, auth, depth+1, no_validation) else return _dorecursion( name, type, klass, known_zone, , depth+1, no_validation ) end end end end return nil end |
#get_closest_known_zone_authorities_for(name) ⇒ Object
:nodoc:
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# File 'lib/dnsruby/recursor.rb', line 471 def (name) # :nodoc: done = false , known_zone = nil while (!done) known_zone = get_closest_known_zone_for(name) # print "GOT KNOWN ZONE : #{known_zone}\n" @@mutex.synchronize { = @@zones_cache[known_zone] # ".", @hints if nothing else } # print "Known authorities : #{known_authorities}\n" # Make sure that known_authorities still contains some authorities! # If not, remove the zone from zones_cache, and start again if ( && .values.length > 0) done = true else @@mutex.synchronize{ @@zones_cache.delete(known_zone) } end end return known_zone, # @TODO@ Need to synchronize access to these! end |
#get_closest_known_zone_for(n) ⇒ Object
:nodoc:
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# File 'lib/dnsruby/recursor.rb', line 435 def get_closest_known_zone_for(n) # :nodoc: # Find the closest parent of name that we know # e.g. for nominet.org.uk, try nominet.org.uk., org.uk., uk., . # does @zones_cache contain the name we're after if (Name === n) n = n.to_s # @TODO@ This is a bit crap! end if (n == nil) TheLog.error("Name is nil") raise ResolvError.new("Nameserver invalid!") end name = n.tr("","") if (name[name.length-1] != ".") name = name + "." end while (true) # print "Checking for known zone : #{name}\n" zone = nil @@mutex.synchronize{ zone = @@zones_cache[name] if (zone != nil) return name end } return false if name=="." # strip the name up to the first dot first_dot = name.index(".") if (first_dot == (name.length-1)) name = "." else name = name[first_dot+1, name.length] end end end |
#prune_rrsets_to_rfc5452(packet, zone) ⇒ Object
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# File 'lib/dnsruby/recursor.rb', line 749 def prune_rrsets_to_rfc5452(packet, zone) # Now prune the response of any unrelated rrsets (RFC5452 section6) # "One very simple way to achieve this is to only accept data if it is # part of the domain for which the query was intended." if (!packet.header.aa) return end if (!packet.question()[0]) return end section_rrsets = packet.section_rrsets section_rrsets.keys.each {|section| section_rrsets[section].each {|rrset| n = Name.create(rrset.name) n.absolute = true if ((n.to_s == zone) || (n.to_s == Name.create(zone).to_s) || (n.subdomain_of?(Name.create(zone))) || (rrset.type == Types::OPT)) # # @TODO@ Leave in the response if it is an SOA, NSEC or RRSIGfor the parent zone # # elsif ((query_name.subdomain_of?rrset.name) && # elsif ((rrset.type == Types.SOA) || (rrset.type == Types.NSEC) || (rrset.type == Types.NSEC3)) #) else TheLog.debug"Removing #{rrset.name}, #{rrset.type} from response from server for #{zone}" packet.send(section).remove_rrset(rrset.name, rrset.type) end } } end |
#query(name, type = Types.A, klass = Classes.IN, no_validation = false) ⇒ Object
This method is much like the normal query() method except it disables the recurse flag in the packet and explicitly performs the recursion.
packet = res.query( "www.netscape.com.", "A")
packet = res.query( "www.netscape.com.", "A", "IN", true) # no validation
The Recursor maintains a cache of known nameservers. DNSSEC validation is performed unless true is passed as the fourth parameter.
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# File 'lib/dnsruby/recursor.rb', line 402 def query(name, type=Types.A, klass=Classes.IN, no_validation = false) # @TODO@ PROVIDE AN ASYNCHRONOUS SEND WHICH RETURNS MESSAGE WITH ERROR!!! # Make sure the hint servers are initialized. @@mutex.synchronize { self.hints=(Hash.new) unless @@hints } @resolver.recurse = false # Make sure the authority cache is clean. # It is only used to store A and AAAA records of # the suposedly authoritative name servers. # TTLs are respected @@mutex.synchronize { if (!@@zones_cache) Recursor.clear_caches(@resolver) end } # So we have normal hashes, but the array of addresses at the end is now an AddressCache # which respects the ttls of the A/AAAA records # Now see if we already know the zone in question # Otherwise, see if we know any of its parents (will know at least ".") known_zone, = (name) # ".", @hints if nothing else # Seed name servers with the closest known authority # ret = _dorecursion( name, type, klass, ".", @hints, 0) ret = _dorecursion( name, type, klass, known_zone, , 0, no_validation) Dnssec.validate(ret) if !no_validation # print "\n\nRESPONSE:\n#{ret}\n" return ret end |
#query_no_validation_or_recursion(name, type = Types.A, klass = Classes.IN) ⇒ Object
:nodoc: all
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# File 'lib/dnsruby/recursor.rb', line 390 def query_no_validation_or_recursion(name, type=Types.A, klass=Classes.IN) # :nodoc: all return query(name, type, klass, true) end |
#recursion_callback ⇒ Object
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# File 'lib/dnsruby/recursor.rb', line 377 def recursion_callback return @callback end |
#recursion_callback=(sub) ⇒ Object
This method takes a code reference, which is then invoked each time a packet is received during the recursive lookup. For example to emulate dig’s C<+trace> function:
res.recursion_callback(Proc.new { |packet|
print packet.additional.inspect
print";; Received %d bytes from %s\n\n",
packetanswersize,
packet.answerfrom);
})
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# File 'lib/dnsruby/recursor.rb', line 371 def recursion_callback=(sub) # if (sub && UNIVERSAL::isa(sub, 'CODE')) @callback = sub # end end |