Get timestamp capabilities of a network interface using ioctl in rust

ioctl_ethtool.rs

#[repr(C)]
#[derive(Default)]
struct ethtool_ts_info {
    cmd: u32,
    so_timestamping: u32,
    phc_index: u32,
    tx_types: u32,
    tx_reserved: [u32; 3],
    rx_filters: u32,
    rx_reserved: [u32; 3],
}

#[repr(C)]
struct ifreq {
    ifrn_name: [u8; 16],
    ifru_data: *mut libc::c_void,
    __empty_space: [u8; 40 - 8],
}

#[allow(dead_code)]
fn is_timestamping_supported() -> std::io::Result<(bool, bool)> {
    // Get time stamping and PHC info
    const ETHTOOL_GET_TS_INFO: u32 = 0x00000041;

    let mut tsi: ethtool_ts_info = ethtool_ts_info {
        cmd: ETHTOOL_GET_TS_INFO,
        ..Default::default()
    };

    let mut ifrn_name = [0; 16];
    ifrn_name[0] = b'e';
    ifrn_name[1] = b'n';
    ifrn_name[2] = b'o';
    ifrn_name[3] = b'1';

    let ifr: ifreq = ifreq {
        ifrn_name,
        ifru_data: (&mut tsi as *mut _) as *mut libc::c_void,
        __empty_space: [0; 40 - 8],
    };

    let fd = cvt(unsafe { libc::socket(libc::AF_INET, libc::SOCK_DGRAM, 0) }).unwrap();

    const SIOCETHTOOL: u64 = 0x8946;
    cvt(unsafe { libc::ioctl(fd, SIOCETHTOOL, &ifr) }).unwrap();

    let supports_software_rx = tsi.so_timestamping & libc::SOF_TIMESTAMPING_RX_SOFTWARE;
    let supports_software_tx = tsi.so_timestamping & libc::SOF_TIMESTAMPING_TX_SOFTWARE;

    Ok((supports_software_rx != 0, supports_software_tx != 0))
}