diff options
Diffstat (limited to 'netwatch-dns.rsc')
-rw-r--r-- | netwatch-dns.rsc | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/netwatch-dns.rsc b/netwatch-dns.rsc new file mode 100644 index 0000000..09365ba --- /dev/null +++ b/netwatch-dns.rsc @@ -0,0 +1,130 @@ +#!rsc by RouterOS +# RouterOS script: netwatch-dns +# Copyright (c) 2022-2024 Christian Hesse <mail@eworm.de> +# https://git.eworm.de/cgit/routeros-scripts/about/COPYING.md +# +# requires RouterOS, version=7.13 +# +# monitor and manage dns/doh with netwatch +# https://git.eworm.de/cgit/routeros-scripts/about/doc/netwatch-dns.md + +:global GlobalFunctionsReady; +:while ($GlobalFunctionsReady != true) do={ :delay 500ms; } + +:do { + :local ScriptName [ :jobname ]; + + :global CertificateAvailable; + :global EitherOr; + :global LogPrint; + :global ParseKeyValueStore; + :global ScriptLock; + + :if ([ $ScriptLock $ScriptName ] = false) do={ + :error false; + } + + :local SettleTime (5m30s - [ /system/resource/get uptime ]); + :if ($SettleTime > 0s) do={ + $LogPrint info $ScriptName ("System just booted, giving netwatch " . $SettleTime . " to settle."); + :error true; + } + + :local DnsServers ({}); + :local DnsFallback ({}); + :local DnsCurrent [ /ip/dns/get servers ]; + + :foreach Host in=[ /tool/netwatch/find where comment~"\\bdns\\b" status="up" ] do={ + :local HostVal [ /tool/netwatch/get $Host ]; + :local HostInfo [ $ParseKeyValueStore ($HostVal->"comment") ]; + + :if ($HostInfo->"disabled" != true) do={ + :if ($HostInfo->"dns" = true) do={ + :set DnsServers ($DnsServers, $HostVal->"host"); + } + :if ($HostInfo->"dns-fallback" = true) do={ + :set DnsFallback ($DnsFallback, $HostVal->"host"); + } + } + } + + :if ([ :len $DnsServers ] > 0) do={ + :if ($DnsServers != $DnsCurrent) do={ + $LogPrint info $ScriptName ("Updating DNS servers: " . [ :tostr $DnsServers ]); + /ip/dns/set servers=$DnsServers; + /ip/dns/cache/flush; + } + } else={ + :if ([ :len $DnsFallback ] > 0) do={ + :if ($DnsFallback != $DnsCurrent) do={ + $LogPrint info $ScriptName ("Updating DNS servers to fallback: " . [ :tostr $DnsFallback ]); + /ip/dns/set servers=$DnsFallback; + /ip/dns/cache/flush; + } + } + } + + :local DohCurrent [ /ip/dns/get use-doh-server ]; + :local DohServers ({}); + + :foreach Host in=[ /tool/netwatch/find where comment~"\\bdoh\\b" status="up" ] do={ + :local HostVal [ /tool/netwatch/get $Host ]; + :local HostInfo [ $ParseKeyValueStore ($HostVal->"comment") ]; + :local HostName [ /ip/dns/static/find where name address=($HostVal->"host") \ + (!type or type="A" or type="AAAA") !disabled !dynamic ]; + :if ([ :len $HostName ] > 0) do={ + :set HostName [ /ip/dns/static/get ($HostName->0) name ]; + } + + :if ($HostInfo->"doh" = true && $HostInfo->"disabled" != true) do={ + :if ([ :len ($HostInfo->"doh-url") ] = 0) do={ + :set ($HostInfo->"doh-url") ("https://" . [ $EitherOr $HostName ($HostVal->"host") ] . "/dns-query"); + } + + :if ($DohCurrent = $HostInfo->"doh-url") do={ + $LogPrint debug $ScriptName ("Current DoH server is still up: " . $DohCurrent); + :error true; + } + + :set ($DohServers->[ :len $DohServers ]) $HostInfo; + } + } + + :if ([ :len $DohCurrent ] > 0) do={ + $LogPrint info $ScriptName ("Current DoH server is down, disabling: " . $DohCurrent); + /ip/dns/set use-doh-server=""; + /ip/dns/cache/flush; + } + + :foreach DohServer in=$DohServers do={ + :if ([ :len ($DohServer->"doh-cert") ] > 0) do={ + :if ([ $CertificateAvailable ($DohServer->"doh-cert") ] = false) do={ + $LogPrint warning $ScriptName ("Downloading certificate failed, trying without."); + } + } + + :local Data false; + :do { + :set Data ([ /tool/fetch check-certificate=yes-without-crl output=user \ + http-header-field=({ "accept: application/dns-message" }) \ + url=(($DohServer->"doh-url") . "?dns=" . [ :convert to=base64 ([ :rndstr length=2 ] . \ + "\01\00" . "\00\01" . "\00\00" . "\00\00" . "\00\00" . "\09doh-check\05eworm\02de\00" . \ + "\00\10" . "\00\01") ]) as-value ]->"data"); + } on-error={ + $LogPrint warning $ScriptName ("Request to DoH server failed (network or certificate issue): " . \ + ($DohServer->"doh-url")); + } + + :if ($Data != false) do={ + :if ([ :typeof [ :find $Data "doh-check-OK" ] ] = "num") do={ + /ip/dns/set use-doh-server=($DohServer->"doh-url") verify-doh-cert=yes; + /ip/dns/cache/flush; + $LogPrint info $ScriptName ("Setting DoH server: " . ($DohServer->"doh-url")); + :error true; + } else={ + $LogPrint warning $ScriptName ("Received unexpected response from DoH server: " . \ + ($DohServer->"doh-url")); + } + } + } +} on-error={ } |