Consider generalizing `ifconfig_ioctlwrap`

[asomers]

ifconfig_ioctlwrap conveniently opens the right socket type and sets all of the error fields, but it only works for ioctls where the data field has type struct ifreq. I'm finding that the majority of ioctls I need to use don't use that data type. Would you agree to change ifconfig_ioctlwrap's fourth argument to an opaque void*?

[Savagedlight]

Can you provide some example code which would benefit from making this change?

[Savagedlight]

Sounds reasonable, especially considering the underlying method it's abstracting. Thank you. :)

I'll get around to processing this coding spree of yours once my dev environment is back up and running!