We have developed a DNS filter extension that works for most applications, but it does not receive all DNS queries. In particular, if we have our extension installed and enabled, we see Safari browsing cause local DNS servers to be used instead of going through our extension. What is the logic for how DNS servers vs. extensions are chosen to resolve DNS queries?

Hello, My team has developed a DNS proxy for macOS. We have this set up with a system extension that interacts with the OS, and an always-running daemon that does all the heavy lifting. Communication between the two is DNS request and response packet traffic. With this architecture what are best practices for how the system extension communicates with a daemon? We tried making the daemon a socket server, but the system extension could not connect to it. We tried using XPC but it did not work and we could not understand the errors that were returned. So what is the best way to do this sort of thing?