[multicast_dns] get IP of mdns SRV target

[guyluz11]

Is there an existing issue for this?

• I have searched the existing issues
• I have read the guide to filing a bug

Use case

Related issues
#75585
#53477

I am trying to find the IP of SRV target.

Examples of srv:
eWeLink_10013abc14.local
HPC0180319938E.local
MiWiFi-RM1800-srv.local

I have tried:

• await InternetAddress.lookup(mdnsName);

import 'package:multicast_dns/multicast_dns.dart';

main() async {
  final MDnsClient client = MDnsClient();
  await client.start();


  await for (final IPAddressResourceRecord ip
  in client.lookup<IPAddressResourceRecord>(
      ResourceRecordQuery.addressIPv4(mdnsName))) {
    print('IP: ${ip.address.toString()}');
  }
  
  client.stop();
}

Using Linux avahi-utils I can find it

$ avahi-resolve-host-name eWeLink_10013abc14.local
eWeLink_10013abc14.local        192.168.31.220

If I can know the serviceType (which I don't) I can use this

String serviceType = '_ewelink._tcp';
String mdnsName = 'eWeLink_10013abc14.local';

final MDnsClient client = MDnsClient();
await client.start();

await for (final PtrResourceRecord ptr in client.lookup<PtrResourceRecord>(
    ResourceRecordQuery.serverPointer(serviceType))) {
  print('PTR: ${ptr.toString()}');

  await for (final IPAddressResourceRecord ip
      in client.lookup<IPAddressResourceRecord>(
          ResourceRecordQuery.addressIPv4(mdnsName))) {
    print('IP: ${ip.address.toString()}');
  }
}
client.stop();

Proposal

Add a new function that can find SRV target IP or to what serviceType it belongs.