routeros-scripts/dhcp-to-dns
2020-01-06 09:40:24 +01:00

66 lines
2.7 KiB
Text

#!rsc
# RouterOS script: dhcp-to-dns
# Copyright (c) 2013-2020 Christian Hesse <mail@eworm.de>
#
# check DHCP leases and add/remove/update DNS entries
:global CharacterReplace;
:global Identity;
:global Domain;
:global HostNameInZone;
:local Zone;
:if ($HostNameInZone = true) do={
:set Zone ("dhcp." . $Identity . "." . $Domain);
} else={
:set Zone ("dhcp." . $Domain);
}
:local Ttl 5m;
:local CommentPrefix "managed by dhcp-to-dns for ";
:foreach DnsRecord in=[ / ip dns static find where comment ~ $CommentPrefix ] do={
:local DnsRecordVal [ / ip dns static get $DnsRecord ];
:local MacAddress [ $CharacterReplace ($DnsRecordVal->"comment") $CommentPrefix "" ];
:if ([ / ip dhcp-server lease print count-only where mac-address=$MacAddress address=($DnsRecordVal->"address") dynamic=yes status=bound ] > 0) do={
:log debug ("Lease for " . $MacAddress . " (" . $DnsRecordVal->"host-name" . ") still exists. Not deleting DNS entry.");
} else={
:local Found false;
:log info ("Lease expired for " . $MacAddress . " (" . $DnsRecordVal->"name" . "), deleting DNS entry.");
/ ip dns static remove $DnsRecord;
}
}
:foreach Lease in=[ / ip dhcp-server lease find where dynamic=yes status=bound ] do={
:local LeaseVal [ / ip dhcp-server lease get $Lease ];
:local Comment ($CommentPrefix . $LeaseVal->"mac-address");
:local HostName [ $CharacterReplace ($LeaseVal->"host-name") " " "" ];
:if ($HostName = "") do={
:set HostName [ $CharacterReplace ($LeaseVal->"mac-address") ":" "-" ];
}
:local Fqdn ($HostName . "." . $Zone);
:local DnsRecord [ / ip dns static find where name=$Fqdn ];
:if ([ :len $DnsRecord ] > 0) do={
:local DnsIp [ / ip dns static get $DnsRecord address ];
:local DupMacLeases [ / ip dhcp-server lease find where mac-address=($LeaseVal->"mac-address") dynamic=yes status=bound ];
:if ([ :len $DupMacLeases ] > 1) do={
:set ($LeaseVal->"address") [ / ip dhcp-server lease get ($DupMacLeases->([ :len $DupMacLeases ] - 1)) address ];
}
:if ([ :len ($LeaseVal->"host-name") ] > 0) do={
:set ($LeaseVal->"address") [ / ip dhcp-server lease get ([ find where host-name=($LeaseVal->"host-name") dynamic=yes status=bound ]->0) address ];
}
:if ($DnsIp = $LeaseVal->"address") do={
:log debug ("DNS entry for " . $Fqdn . " does not need updating.");
} else={
:log info ("Replacing DNS entry for " . $Fqdn . ", new address is " . $LeaseVal->"address" . ".");
/ ip dns static set name=$Fqdn address=($LeaseVal->"address") ttl=$Ttl comment=$Comment $DnsRecord;
}
} else={
:log info ("Adding new DNS entry for " . $Fqdn . ", address is " . $LeaseVal->"address" . ".");
/ ip dns static add name=$Fqdn address=($LeaseVal->"address") ttl=$Ttl comment=$Comment;
}
}