fn read_msg_with_seq()

in src/linux.rs [168:197]

• 24 lines of code
• 7 McCabe index (conditional complexity)

fn read_msg_with_seq(fd: &mut RouteSocket, seq: u32, kind: u16) -> Result<(nlmsghdr, Vec<u8>)> {
    loop {
        let buf = &mut [0u8; NETLINK_BUFFER_SIZE];
        let len = fd.read(buf.as_mut_slice())?;
        let mut next = &buf[..len];
        while size_of::<nlmsghdr>() <= next.len() {
            let (hdr, mut msg) = next.split_at(size_of::<nlmsghdr>());
            let hdr: nlmsghdr = hdr.try_into()?;
            // `msg` has the remainder of this message plus any following messages.
            // Strip those it off and assign them to `next`.
            debug_assert!(size_of::<nlmsghdr>() <= hdr.nlmsg_len as usize);
            (msg, next) = msg.split_at(hdr.nlmsg_len as usize - size_of::<nlmsghdr>());

            if hdr.nlmsg_seq != seq {
                continue;
            }

            if hdr.nlmsg_type == NLMSG_ERROR {
                // Extract the error code and return it.
                let err = parse_c_int(msg)?;
                if err != 0 {
                    return Err(Error::from_raw_os_error(-err));
                }
            } else if hdr.nlmsg_type == kind {
                // Return the header and the message.
                return Ok((hdr, msg.to_vec()));
            }
        }
    }
}