socket::sockopt adding SOL_FILTER level options for illumos.

[devnexen]

Respectively FIL_ATTACH/FIL_DETACH to bind/unbind a filter to a socket to for example delay connection acceptance until data (datafilt) is received.

[SteveLauC]

I am thinking if this 'static lifetime would be too restrictive? I do not see a way to specify lifetime parameter using the macro, maybe we can implement the nix::sys::socket::SetSockOpt trait manually?

[SteveLauC]

We are passing the whole buffer to the syscall, is this something expected?

BTW, the below code should mirror the original implementation:

#[derive(Clone)]
pub struct FilterAttach<'a> {
    _marker: std::marker::PhantomData<&'a ()>
}

impl<'a> FilterAttach<'a> {
    pub fn new() -> Self {
        Self {
            _marker: std::marker::PhantomData,
        }
    }
}

impl<'a> SetSockOpt for FilterAttach<'a> {
    type Val = &'a OsStr;

    fn set<F: std::os::unix::prelude::AsFd>(&self, fd: &F, val: &Self::Val) -> nix::Result<()> {
        unsafe {
            let res = libc::setsockopt(
                fd.as_fd().as_raw_fd(),
                libc::SOL_FILTER,
                libc::FIL_ATTACH,
                val.as_ptr().cast(),
                val.len() as libc::socklen_t,
            );
            Errno::result(res).map(drop)
        }
    }
}

[SteveLauC]

Please use the constant from the libc crate:)

[devnexen]

yes I tried to avoid the cast ;) but ok

[SteveLauC]

Can we have tests for this?