How do I update a PTR record on a DDNS server, with dnsjava?

Question

I am able to update A, AAAA, and TXT records without an issue. Unfortunately, I haven't yet been able to find any examples of how to update a PTR record.

Here's the code I'm using to send the updates:

public void sendA(Name host, Name zone, String ip) throws IOException {
    Update update = new Update(zone);
    update.replace(host, Type.A, DNS_TTL, ip);
    sendUpdate(update);
}

public void sendPTR(Name host, Name zone, String ip) throws IOException {
    Update update = new Update(zone);
    update.replace(host, Type.PTR, DNS_TTL, ip);
    sendUpdate(update);        
}

public void sendUpdate(Update update) throws UnknownHostException, IOException {
    Resolver res = new SimpleResolver(DNS_IP);
    res.setTCP(true);
    Message response = res.send(update);
}

In that block, sendA works perfectly fine. sendPTR tries to do the exact same thing, but since it's a PTR, it should be putting the IP on the left, and the hostname on the right.

For example:

sendPTR(Name.fromString("foo.domain.net."), Name.fromString("0.168.192.in-addr.arpa."), "1");

Results in an update that looks like this:

foo.domain.net    86400 IN  PTR   1.0.168.192.in-addr.arpa.

With that, I get an RCode 10, which means "Name not contained in zone".

I tried flipping the ip and host, but that resulted in "'1' is not an absolute name."

This is my first project with dnsjava, so I fully expect that I'm just missing that one class, with that one function, that will do all of this for me. If someone could kindly point me to that class, it would be much appreciated.

Answer 1

I knew it! All I needed to do was post the question for the answer to come to me.

I just needed to explicitly instantiate a PTRRecord and use Update.replace(Record).

public void sendPTR(PTRRecord rec, Name zone) throws IOException {
    Update update = new Update(zone);
    update.replace(rec);
    sendUpdate(update);
}

...

PTRRecord rec = new PTRRecord(Name.fromString("1.0.168.192.in-addr.arpa."),DClass.IN, 86400, host);
sendPTR(rec, Name.fromString("0.168.192.in-addr.arpa."));