Where can I find a C++ DNS Library?

Question

I know DNS is typically handled by the operating system, but I'm working under the assumption that DNS has been broken on the target system (this is a tool to diagnose DNS misconfiguration). I therefore need to implement DNS myself, to check the results I get back from the system against a known good DNS server.

You can do this with the NSLookup or Dig tools, specifying a DNS server address manually, but it appears the Windows API calls for doing this (e.g. GetAddressByName) don't allow me to specify a server to query, and use the system's configured target instead.

I tried to look for the RFCs on DNS, but unfortunately they are clear as mud to me -- they make the HTTP spec look like the clearest and most well written spec ever produced.

I also don't want to reinvent something that someone else has already done several times before.

Answer 1

You might try: http://25thandclement.com/~william/projects/dns.c.html . Also, see Need To Build Simple DNS Resolver in C

Actually, a Google search of "DNS resolver C" reveals several possibilities.

Answer 2

Try the c-ares library, which as I understand it does implement its own DNS stack. I've used it successfully on linux, and they say that it supports Windows, though I haven't tried it myself. It isn't C++, just plain C, but you can easily enough write a C++ wrapper for it.

It gets bonus points for being asynchronous, and providing hooks by which you can integrate it with an existing event loop.

Answer 3

I know that the question is old, but I haven't found good answer for me here. I have found poslib as the best dns library with very easy interface.