### Settings ###
:global ddnsuser <username>
:global ddnstoken "<token>"
:global ddnshost <dyndnshost>
:global theinterface "<wan interface>"

### Script Begins ###
:global ipfresh [ /ip address get [/ip address find interface=$theinterface ] address ]
:global ipddns [:resolve $ddnshost]

# All return codes from members.dyndns.org
:global resultcodes {good="Update successful";
    nochg="WARNING: Update not needed, repeated attempts may cause you to be blocked.";
    badauth="The username and password pair do not match a real user.";
    notfqdn="The hostname specified is not a fully-qualified domain name.";
    nohost="The hostname specified does not exist in this user account.";
    numhost="Too many hosts (more than 20) specified in an update.";
    abuse="The hostname specified is blocked for update abuse.";
    badagent="The user agent was not sent or HTTP method is not permitted.";
    dnserr="DNS error encountered.";
    911="There is a problem or scheduled maintenance on our side."
}

# Check ip address and remove subnet.
:if ([ :typeof $ipfresh ] = nil ) do={
    :log info ("DynDNS: No ip address on $theinterface .")
} else={
    :for i from=( [:len $ipfresh] - 1) to=0 do={ 
        :if ( [:pick $ipfresh $i] = "/") do={ 
            :set ipfresh [:pick $ipfresh 0 $i];
        }
    }
}

# Determine if an update is required.
:if ($ipddns != $ipfresh) do={
    :local logname "dyndns.$ddnshost"
    :log info ("DynDNS: IP-DynDNS = $ipddns")
    :log info ("DynDNS: IP-Fresh = $ipfresh")
    :log info "DynDNS: Update IP needed, saving UPDATE...!"
    /tool fetch url="https://$ddnsuser:$ddnstoken@members.dyndns.org/v3/update?hostname=$ddnshost&myip=$ipfresh" keep-result=yes dst-path=$logname;
    :local result [/file get [find name="$logname" ] contents ]
    /file remove [ find name="$logname" ]
    :put "Server returned: $result";
    # Separate return code from IP address
    :for i from=0 to=( [:len $result] - 1) do={ 
        :if ( [:pick $result $i] = " ") do={
        :set result [:pick $result 0 $i]
        }
    }
    :put "Return code is: $result";
    :foreach resultcode,desc in=$resultcodes do={
        :if ( $result = $resultcode ) do={
        :log info ("DynDNS: $desc")
        }
    }
    :log info ("DynDNS: IP updated to $ipfresh!")
} else={
    :log info ("DynDNS: IP-DynDNS = $ipddns")
    :log info ("DynDNS: IP-Fresh = $ipfresh")
    :log info "DynDNS: no update required"
}