How to use `SockLevel` for `setsockopt` and IP_MULTICAST_IF

[keepsimple1]

nix/src/sys/socket/mod.rs

Line 1585 in d922c72

pub enum SockLevel {

I cannot find how SockLevel is used in the code. For example, setsockopt did not have a level argument:

nix/src/sys/socket/mod.rs

Line 1639 in d922c72

pub fn setsockopt<O: SetSockOpt>(fd: RawFd, opt: O, val: &O::Val) -> Result<()> {

How can we use SockLevel? I have a use case that needs to do something like this (not real code):

setsockopt(IPPROTO_IP, IP_MULTICAST_IF, <value>);

I cannot find IP_MULTICAST_IF in Nix either. Did I miss it somewhere? Thanks.

[asomers]

Ooh, great question! SockLevel is actually dead code. AFAICT, its use was eliminated way back in PR #133 . So we should delete it. But what you probably ought to do is submit a PR that adds this socket option using sockopt_impl! to src/sys/socket/sockopt.rs.

[keepsimple1]

thanks @asomers for opening PR #1362 to remove SockLevel. I will submit a PR to add IP_MULTICAST_IF .