I’m seeing an EINVAL result when trying to do a sndmsg() call to a UNIX socket. The man page says that means that the sum of the iov_lens overflows an ssize_t, but an ssize_t is 8 bytes on this machine and there’s only one iov and its length is 671. Last I checked that doesn’t overflow anything but a char. What gives? Same code works fine in Linux and when using UDP or TCP.
If ever you find yourself wanting to do some network programming in C, C++, or any other language that uses the socket paradigm, you must be careful. You are only inches from the edge of the precipice of insanity.
Luckily, some guy who calls himself Beej wrote a fantastic guide to network programming. He takes you by the hand and leads you gently away from the precipice. His guide is fun and easy to grok, but doesn’t water the topic down. It’s a fine piece of writing.
Even if you’re writing Ruby network code, for example, which streamlines much of the insanity (thanks to exceptions and some nice OO abstractions like TCPServer), the socket concepts you will gain from at least skimming this guide will be a huge help.
Announcing the latest version of hearnet:
the (in)famous little JACK toy. The name may bring back
memories of your favorite lunch lady, but the sound of your own network traffic
will move you in ways that she never could have hoped to move you. I hope
that’s a good thing.
This release sports filter expressions (a la tcpdump) and the ability to drop
privileges and run as a normal user, and therefore play nice with the other
JACK apps in your playground.
Enjoy, and don’t get any hair in your network.