#!/usr/bin/ruby

#
# Copyright (c) 2004 Peter Palfrader <peter@palfrader.org>
#
# All rights reserved.
#

require "ldap"
require "getoptlong"
require "myldap"
require "yaml"
require "optparse"

# defaults
@force_push = false
@verbose = false

def show_help(parser, code=0, io=STDOUT)
  io.puts parser
  exit(code)
end
ARGV.options do |opts|
	opts.on_tail("-h", "--help", "Display this help screen") { show_help(opts) }
	opts.on("-f", "--force"              , String, "Force Push to Slaves")                         { @force_push = true }
	opts.on("-v", "--verbose"              , String, "Show SSH-Transfer more verbose")                         { @verbose = true }
	opts.parse!
end

def fatal(reason)
	STDERR.puts reason
	exit 1;
end

def getOldSerial(name)
	filename = @baseDir+'/'+name
	return nil unless FileTest.exists?(filename)
	File.open(filename).readlines.each{ |line|
		match = /^; serial: (\d+)/.match(line)
		next unless match
		serial = match[1]
		return serial.to_i
	}
	return nil
end

def makeNewSerial(oldSerial)
	serial = Time.now.strftime("%Y%m%d00").to_i
	if oldSerial
		serial = (oldSerial + 1) if oldSerial >= serial
	end
	return serial
end

def setRecord(domains, type, rrdata, dn)
	domains.each{ |d|
		handled = false
		domainparts = d.split('.')
		localpart = []
		while domainparts.length > 0
			if @zones.has_key?(domainparts.join('.'))
				left = localpart.length > 0 ? localpart.join('.') : '@'
				right = domainparts.join('.')
				@zones[ right ]['records'][left] = {} unless @zones[ right ]['records'][left]
				if @zones[ right ]['records'][left].has_key?(type)
					throw "There already are #{type} records for #{left} in #{right} (dn=#{dn}"
				end
				@zones[ right ]['records'][left][type] = [ rrdata ]
				handled = true
				break
			end
			localpart << domainparts.shift
		end
		# FIXME
		#STDERR.puts "Warning: Did not find a place to put #{d}'s #{type} records" unless handled
	}
end

def setMXs(domains, hosts, dn)
	throw "Cannot handle mail entry for more than 1 host (dn=#{dn})" if hosts.length != 1
	host = hosts[0]
	rrdata = @rrdata['MX'][host]
	throw "Do not know MX data for host #{host} (dn=#{dn})" unless rrdata
	setRecord(domains, 'MX', rrdata, dn);
end

def setAs(domains, hosts, dn)
	throw "Cannot handle A entry for more than 1 host (dn=#{dn})" if hosts.length != 1
	host = hosts[0]
	rrdata = @rrdata['A'][host]
	throw "Do not know A data for host #{host} (dn=#{dn})" unless rrdata
	setRecord(domains, 'A', rrdata, dn);
end

def setAsDirect(domains, ipaddress, dn)
	throw "Cannot handle A entry for more than 1 ipaddress (dn=#{dn})" if ipaddress.length != 1
	setRecord(domains, 'A', ipaddress, dn);
end



@config = YAML::load( File.open( '/etc/noreply/config' ) )

@defaultSoaPerson = @config['module']['bind']['soaPerson']
@defaultTTL = @config['module']['bind']['ttl']
@defaultNameservers = @config['module']['bind']['nameservers']
@baseDir = @config['module']['bind']['baseDir']
@namedconf = @config['module']['bind']['namedconf']
@pushedList = @config['module']['bind']['pushedList']
@reload = @config['module']['bind']['reload']
@rrdata = @config['module']['bind']['rrdata']
@Origin = @config['module']['bind']['thisNameserver']
@nameserverIPmapping = @config['module']['bind']['nameserverIPmapping']
@TSIGslaves = @config['module']['bind']['TSIGslaves']
@pushToServers = @config['module']['bind']['pushToServers']
@SSHidentityFile = @config['module']['bind']['SSHidentityFile']

ldap = MyLDAP.new(@config, "ldap2bind")
magicItems = ldap.conn.search2(@config['basedn'], LDAP::LDAP_SCOPE_SUBTREE, '(|(tnMagicDNS=yes)(objectClass=tnDNSrr))')
masterDomains = ldap.conn.search2(@config['basedn'], LDAP::LDAP_SCOPE_SUBTREE, 'objectclass=tnDNSsoa')
slaveDomains = ldap.conn.search2(@config['basedn'], LDAP::LDAP_SCOPE_SUBTREE, 'objectclass=tnDNSsecondary')

@zones = {}
@secondaryzonesUnique = {}
@secondaryzones = []

masterDomains.each { |d|
	domain = {}
	throw "Domain starts with dot: #{d['tnDNSdomainname'][0]}" if ((d['tnDNSdomainname'][0] =~ /^\./) != nil)
	domain['soaPerson'] = d['tnDNSsoaPerson'] ? d['tnDNSsoaPerson'][0] : @defaultSoaPerson
	domain['ttl'] = d['tnDNSttl'] ? d['tnDNSttl'][0] : @defaultTTL

	domain['records'] = {}
	domain['records']['@'] = {}
	domain['records']['@']['NS'] = d['tnDNSnameservers'] ? d['tnDNSnameservers'] : @defaultNameservers

	name = d['tnDNSdomainname'][0]
	if @zones.has_key?( name )
		STDERR.puts "Warning: Domain #{name} has multiple ldap entries in master!"
	end
	@zones[ name ] = domain

	@secondaryzonesUnique[name] = 1
	slaveentry = {}
	slaveentry['name'] = name
	slaveentry['master'] = [ @nameserverIPmapping[@Origin] ]
	slaveentry['slaves'] = domain['records']['@']['NS'].reject{|e| e == @Origin}
	@secondaryzones << slaveentry
}
slaveDomains.each { |d|
	name = d['tnDNSdomainname'][0]
	if @secondaryzonesUnique.has_key?( name )
#		STDERR.puts "Warning: Domain #{name} has multiple ldap entries as slaves!"
	end
	@secondaryzonesUnique[name] = 1
	slaveentry = {}
	slaveentry['name'] = name
	slaveentry['master'] = d['tnDNSprimary']
	slaveentry['slaves'] = d['tnDNSnameservers']
	@secondaryzones << slaveentry
	d['tnDNSnameservers'].each{ |secondary|
		if not @nameserverIPmapping.has_key?(secondary)
			STDERR.puts "Warning: Unknown nameserver #{secondary} for domain #{name}."
			next
		end
	}
}

magicItems.each { |m|
	recognized_one = false
	m['objectClass'].each{ |objectclass|
		case objectclass
			when 'top', 'tnMailRemotePerson'
			when 'tnMailDomain', 'tnMailRelay', 'tnUUCPSystem'
				setMXs(m['tnMailDomainname'], m['tnHost'], m['dn'][0])
			when 'tnWebVHost'
				setAs(m['tnWebVHostServerName'], m['tnHost'], m['dn'][0])
				if m['tnWebVHostServerAlias']
					m['tnWebVHostServerAlias'].each{ |vhostalias|
						setAs(vhostalias, m['tnHost'], m['dn'][0])
					}
				end
			when 'tnDNSrr'
				if m['tnDNSaRecord']
					setAsDirect(m['tnDNSdomainname'], m['tnDNSaRecord'], m['dn'][0])
				else
					STDERR.puts "Warning: Unhandled tnDNSrr: #{m['dn'][0]}."
				end
			else
				STDERR.puts "Warning: objectClass #{objectclass} in #{m['dn'][0]} not recognized."
		end
	}

}

# clean up
Dir.entries( @baseDir ).each{ |e|
	next if ((e =~ /^\./) != nil)
	File.unlink( @baseDir + '/' + e ) unless @zones.has_key?( e )
}

zonelist = [] 
zonelist << "// --------------------------------------------------"
zonelist << "// --                                              --"
zonelist << "// -- " + "master zones from ldap".center(44)+ " --"
zonelist << "// --                                              --"
zonelist << "// -- this file has been automatically created by  --"
zonelist << "// -- ldap2bind on "+Time.now.strftime("%a, %d %b %Y %H:%M:%S %Z")+"  --      IGNORE_LINE"
zonelist << "// --------------------------------------------------"
zonelist << ""
reload_required = false
@zones.keys.sort.each{ |name|
	domain = @zones[name]

	zonelist << "zone \"#{name}\" {"
	zonelist << "	type master;"
	zonelist << "	file \"#{@baseDir}/#{name}\";"
	zonelist << "	allow-query { any; };"
	zonelist << "	allow-transfer {"
	have_secondaries = false
	domain['records']['@']['NS'].reject{|e| e == @Origin}.each{ |secondary|
		if @TSIGslaves.has_key?(secondary)
			zonelist << "		key #{@TSIGslaves[secondary]}; // #{secondary}"
		else
			if not @nameserverIPmapping.has_key?(secondary)
				STDERR.puts "Warning: Unknown nameserver #{secondary} in zone #{name}: cannot grant zone transfer"
				next
			end
			ip = @nameserverIPmapping[secondary]
			zonelist << "		#{ip}; // #{secondary}"
			zonelist << "		::ffff:#{ip}/128; // #{secondary}"
		end
		have_secondaries = true
	}
	zonelist << "		\"none\";" unless have_secondaries
	zonelist << "	};"
	zonelist << "};"
	zonelist << ""


	serial = makeNewSerial(getOldSerial(name))
	zone = []
	zone << "; --------------------------------------------------"
	zone << "; --                                              --"
	zone << "; -- " + name.center(44)+ " --"
	zone << "; --                                              --"
	zone << "; -- this file has been automatically created by  --"
	zone << "; -- ldap2bind on "+Time.now.strftime("%a, %d %b %Y %H:%M:%S %Z")+"  --      IGNORE_LINE"
	zone << "; --------------------------------------------------"
	zone << "; serial: "+serial.to_s+"      IGNORE_LINE"
	zone << ";"
	zone << "$TTL #{domain['ttl']}"
	zone << "@		#{domain['ttl']}	IN	SOA	#{ @Origin }	#{ domain['soaPerson'] } ("
	zone << "					#{ serial } ; IGNORE_LINE"
	zone << "					3H 33m 5W 20m )" # or  {domain['ttl']} instead of 20m"

	# We need to sort here so we get the same order every time, so we can
	# compare the result with the on disk copy
	domain['records'].keys.sort.each{ |dom|
		domain['records'][dom].keys.sort.each{ |type|
			domain['records'][dom][type].sort.each{ |l|
				zone << "#{dom}		IN	#{type}	#{l}"
			}
		}
	}
	zone << "localhost	IN	A	127.0.0.1"
	#zone << "localhost.	IN	A	127.0.0.1"
	zone << ""
	zone << "; vim:set syn=dns:"

	zone.map!{ |line| line + "\n" }

	if (FileTest.exists?(@baseDir + '/' + name))
		on_disk = File.new( @baseDir + '/' + name, "r" ).readlines.reject{ |e| e =~ /IGNORE_LINE/ }
		next if on_disk == zone.reject{ |e| e =~ /IGNORE_LINE/ }
	end
	f = File.new( @baseDir + '/' + name, "w" )
	f.write(zone)
	f.close
	reload_required = true
}
pushingList = []
@secondaryzones.sort{|x,y| x['name'] <=> y['name'] }.each{ |slaveentry|
	if slaveentry['slaves'].include?(@Origin)
		zonelist << "zone \"#{slaveentry['name']}\" {"
		zonelist << "	type slave;"
		zonelist << "	file \"slave-ldap-#{slaveentry['name']}\";"
		zonelist << "	allow-transfer { \"none\"; };"
		zonelist << "	masters {"
		slaveentry['master'].each{ |master|
			zonelist << "		#{master};"
		};
		zonelist << "	};"
		zonelist << "};"
		zonelist << ""
	end
	pushingList << slaveentry['name']+" "+slaveentry['master'].join('|')+" "+" "+slaveentry['slaves'].join(" ")
}


zonelist.map!{ |line| line + "\n" }

if (FileTest.exists?(@namedconf))
	on_disk = File.new(@namedconf).readlines.reject{ |e| e =~ /IGNORE_LINE/ }
	reload_required = true unless on_disk == zonelist.reject{ |e| e =~ /IGNORE_LINE/ }
else
	reload_required = true
end
f = File.new( @namedconf, "w" )
f.write(zonelist)
f.close


pushingList.map!{ |line| line + "\n" }
# sometimes force push so set it per default to true
push_required=@force_push

if (FileTest.exists?(@pushedList))
	on_disk = File.new(@pushedList).readlines.reject{ |e| e =~ /IGNORE_LINE/ }
	push_required = true unless on_disk == pushingList.reject{ |e| e =~ /IGNORE_LINE/ }
else
	push_required = true
end
if push_required
	f = File.new( @pushedList, "w" );
	f.write(pushingList)
	f.close
	if @pushToServers
		@pushToServers.each{ |server|
			puts "Pushing to #{server}"
			if @verbose 
				system("env -i ssh -4 -v -T -l root -i #{@SSHidentityFile} #{server} < #{@pushedList}") or throw "push to #{server} failed\n"
			else
				system("env -i ssh -4 -T -l root -i #{@SSHidentityFile} #{server} < #{@pushedList}") or throw "push to #{server} failed\n"
			end
		}
	end
end


if (reload_required)
	puts "Reloading bind."
	system(@reload) or throw "#{@reload} failed\n";
end