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    use std::io;
    use std::mem::size_of;
    use std::net::{Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6};

    pub(crate) fn new_ip_socket(addr: SocketAddr, socket_type: libc::c_int) -> io::Result<libc::c_int> {
        let domain = match addr {
            SocketAddr::V4(..) => libc::AF_INET,
            SocketAddr::V6(..) => libc::AF_INET6,
        };

        new_socket(domain, socket_type)
    }

    /// Create a new non-blocking socket.
    pub(crate) fn new_socket(domain: libc::c_int, socket_type: libc::c_int) -> io::Result<libc::c_int> {
        #[cfg(any(
            target_os = "android",
            target_os = "dragonfly",
            target_os = "freebsd",
            target_os = "illumos",
            target_os = "linux",
            target_os = "netbsd",
            target_os = "openbsd"
        ))]
        let socket_type = socket_type | libc::SOCK_NONBLOCK | libc::SOCK_CLOEXEC;

        // Gives a warning for platforms without SOCK_NONBLOCK.
        #[allow(clippy::let_and_return)]
        let socket = syscall!(socket(domain, socket_type, 0));

        // Mimick `libstd` and set `SO_NOSIGPIPE` on apple systems.
        #[cfg(target_vendor = "apple")]
        let socket = socket.and_then(|socket| {
            syscall!(setsockopt(
                socket,
                libc::SOL_SOCKET,
                libc::SO_NOSIGPIPE,
                &1 as *const libc::c_int as *const libc::c_void,
                size_of::<libc::c_int>() as libc::socklen_t
            ))
            .map(|_| socket)
        });

        // Darwin doesn't have SOCK_NONBLOCK or SOCK_CLOEXEC. Not sure about
        // Solaris, couldn't find anything online.
        #[cfg(any(target_os = "ios", target_os = "macos", target_os = "solaris"))]
        let socket = socket.and_then(|socket| {
            // For platforms that don't support flags in socket, we need to
            // set the flags ourselves.
            syscall!(fcntl(socket, libc::F_SETFL, libc::O_NONBLOCK))
                .and_then(|_| syscall!(fcntl(socket, libc::F_SETFD, libc::FD_CLOEXEC)).map(|_| socket))
                .map_err(|e| {
                    // If either of the `fcntl` calls failed, ensure the socket is
                    // closed and return the error.
                    let _ = syscall!(close(socket));
                    e
                })
        });

        socket
    }

    /// A type with the same memory layout as `libc::sockaddr`. Used in converting Rust level
    /// SocketAddr* types into their system representation. The benefit of this specific
    /// type over using `libc::sockaddr_storage` is that this type is exactly as large as it
    /// needs to be and not a lot larger. And it can be initialized cleaner from Rust.
    #[repr(C)]
    pub(crate) union SocketAddrCRepr {
        v4: libc::sockaddr_in,
        v6: libc::sockaddr_in6,
    }

    impl SocketAddrCRepr {
        pub(crate) fn as_ptr(&self) -> *const libc::sockaddr {
            self as *const _ as *const libc::sockaddr
        }
    }

    /// Converts a Rust `SocketAddr` into the system representation.
    pub(crate) fn socket_addr(addr: &SocketAddr) -> (SocketAddrCRepr, libc::socklen_t) {
        match addr {
            SocketAddr::V4(ref addr) => {
                // `s_addr` is stored as BE on all machine and the array is in BE order.
                // So the native endian conversion method is used so that it's never swapped.
                let sin_addr = libc::in_addr {
                    s_addr: u32::from_ne_bytes(addr.ip().octets()),
                };

                let sockaddr_in = libc::sockaddr_in {
                    sin_family: libc::AF_INET as libc::sa_family_t,
                    sin_port: addr.port().to_be(),
                    sin_addr,
                    sin_zero: [0; 8],
                    #[cfg(any(
                        target_os = "dragonfly",
                        target_os = "freebsd",
                        target_os = "ios",
                        target_os = "macos",
                        target_os = "netbsd",
                        target_os = "openbsd"
                    ))]
                    sin_len: 0,
                };

                let sockaddr = SocketAddrCRepr { v4: sockaddr_in };
                let socklen = size_of::<libc::sockaddr_in>() as libc::socklen_t;
                (sockaddr, socklen)
            }
            SocketAddr::V6(ref addr) => {
                let sockaddr_in6 = libc::sockaddr_in6 {
                    sin6_family: libc::AF_INET6 as libc::sa_family_t,
                    sin6_port: addr.port().to_be(),
                    sin6_addr: libc::in6_addr {
                        s6_addr: addr.ip().octets(),
                    },
                    sin6_flowinfo: addr.flowinfo(),
                    sin6_scope_id: addr.scope_id(),
                    #[cfg(any(
                        target_os = "dragonfly",
                        target_os = "freebsd",
                        target_os = "ios",
                        target_os = "macos",
                        target_os = "netbsd",
                        target_os = "openbsd"
                    ))]
                    sin6_len: 0,
                    #[cfg(any(target_os = "solaris", target_os = "illumos"))]
                    __sin6_src_id: 0,
                };

                let sockaddr = SocketAddrCRepr { v6: sockaddr_in6 };
                let socklen = size_of::<libc::sockaddr_in6>() as libc::socklen_t;
                (sockaddr, socklen)
            }
        }
    }

    /// Converts a `libc::sockaddr` compatible struct into a native Rust `SocketAddr`.
    ///
    /// # Safety
    ///
    /// `storage` must have the `ss_family` field correctly initialized.
    /// `storage` must be initialised to a `sockaddr_in` or `sockaddr_in6`.
    pub(crate) unsafe fn to_socket_addr(
        storage: *const libc::sockaddr_storage,
    ) -> io::Result<SocketAddr> {
        match (*storage).ss_family as libc::c_int {
            libc::AF_INET => {
                // Safety: if the ss_family field is AF_INET then storage must be a sockaddr_in.
                let addr: &libc::sockaddr_in = &*(storage as *const libc::sockaddr_in);
                let ip = Ipv4Addr::from(addr.sin_addr.s_addr.to_ne_bytes());
                let port = u16::from_be(addr.sin_port);
                Ok(SocketAddr::V4(SocketAddrV4::new(ip, port)))
            }
            libc::AF_INET6 => {
                // Safety: if the ss_family field is AF_INET6 then storage must be a sockaddr_in6.
                let addr: &libc::sockaddr_in6 = &*(storage as *const libc::sockaddr_in6);
                let ip = Ipv6Addr::from(addr.sin6_addr.s6_addr);
                let port = u16::from_be(addr.sin6_port);
                Ok(SocketAddr::V6(SocketAddrV6::new(
                    ip,
                    port,
                    addr.sin6_flowinfo,
                    addr.sin6_scope_id,
                )))
            }
            _ => Err(io::ErrorKind::InvalidInput.into()),
        }
    }