🚀 go-pugleaf

>I was just wondering if it is possible to connect and send commands to the 
>RPC portmapper without using RPC calls (svc_xxx or pmap_xxx) but tli or 
>socket calls.

Well, yes, it is possible - after all, ultimately, the code that
implements RPC calls generally does so using sockets or TLI calls....

I.e., yes, you can do it, but the commands you send to it are just RPC
calls, so the only way to avoid using the RPC routines is to do just
what they do....

>The protocol specifications for the portmapper (appendix A of the RFC1057) 
>does not say anything about the low level commands that the portmapper 
>recognizes.

Yes, it does.  It gives a description, "in RPC Language", of the port
mapper protocol.  If the fact that the description is given "in RPC
Language" doesn't tell you that the port mapper is an RPC service, the
fact that section 7.4.2 says, in as many words:

   Broadcast calls use the Port Mapper RPC service to achieve their
   semantics.  See Appendix A for more information.

should sure give you a clue that it's an RPC service....

I.e., no, this isn't like an SMTP or FTP server, wherein you can just
type commands at it; it's an RPC server that's just like any other RPC
server, except that it has to have a well-known port number - after all,
it's kind of hard to ask the portmapper what the port number of the
portmapper is if you don't *already* know what its port number is.