ioctl() forever?

hey, I was just trying rr for my first time today!

I'm not sure how practical it'll be to solve this problem in general. My approach was to try and make ioctls more like syscalls - i.e. something that looks like a normal function call. That would make the simple cases simpler, by getting rid of ioctl structs entirely for the simple cases.

But this won't do anything for the more complex cases you brought up. The problem in those cases is just that C is a very low level language, and anything that's complex enough to handle those cases isn't going to feel natural and simple in C. This is my complaint with those advocating netlink as a wholesale replacement for ioctls - it's more complicated than it needs to be for the simple cases. But for the more complicated cases maybe it's the right approach.

There's another possibility that just occurred to me because I saw you were using it today - cap'n proto. If the problem is that defining complex data structures in a portable, ABI independent way sucks, this is exactly what cap'n proto is intended for. When I last looked at it the story for using it from C seemed incomplete, but maybe this has changed - might be worth another look.

For those unfamiliar: cap'n proto [1] is a schema language for defining ABI independent types. Crucially, unlike things like protobufs, it doesn't have pack/unpack operations - the wire format is the in memory format. It's like defining types in C using only standard sized integers, only without all the razor sharp edges and some really useful features.

1: https://capnproto.org/