Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1332 insertions, 0 deletions

diff --git a/third_party/rust/miow/src/net.rs b/third_party/rust/miow/src/net.rs
new file mode 100644
index 0000000000..e30bc2d2bf
--- /dev/null
+++ b/third_party/rust/miow/src/net.rs
@@ -0,0 +1,1332 @@
+//! Extensions and types for the standard networking primitives.
+//!
+//! This module contains a number of extension traits for the types in
+//! `std::net` for Windows-specific functionality.
+
+use std::cmp;
+use std::io;
+use std::mem;
+use std::net::{Ipv4Addr, Ipv6Addr, SocketAddrV4, SocketAddrV6};
+use std::net::{SocketAddr, TcpListener, TcpStream, UdpSocket};
+use std::os::windows::prelude::*;
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+use winapi::ctypes::*;
+use winapi::shared::guiddef::*;
+use winapi::shared::in6addr::{in6_addr_u, IN6_ADDR};
+use winapi::shared::inaddr::{in_addr_S_un, IN_ADDR};
+use winapi::shared::minwindef::*;
+use winapi::shared::minwindef::{FALSE, TRUE};
+use winapi::shared::ntdef::*;
+use winapi::shared::ws2def::SOL_SOCKET;
+use winapi::shared::ws2def::*;
+use winapi::shared::ws2ipdef::*;
+use winapi::um::minwinbase::*;
+use winapi::um::winsock2::*;
+
+/// A type to represent a buffer in which a socket address will be stored.
+///
+/// This type is used with the `recv_from_overlapped` function on the
+/// `UdpSocketExt` trait to provide space for the overlapped I/O operation to
+/// fill in the address upon completion.
+#[derive(Clone, Copy)]
+pub struct SocketAddrBuf {
+    buf: SOCKADDR_STORAGE,
+    len: c_int,
+}
+
+/// A type to represent a buffer in which an accepted socket's address will be
+/// stored.
+///
+/// This type is used with the `accept_overlapped` method on the
+/// `TcpListenerExt` trait to provide space for the overlapped I/O operation to
+/// fill in the socket addresses upon completion.
+#[repr(C)]
+pub struct AcceptAddrsBuf {
+    // For AcceptEx we've got the restriction that the addresses passed in that
+    // buffer need to be at least 16 bytes more than the maximum address length
+    // for the protocol in question, so add some extra here and there
+    local: SOCKADDR_STORAGE,
+    _pad1: [u8; 16],
+    remote: SOCKADDR_STORAGE,
+    _pad2: [u8; 16],
+}
+
+/// The parsed return value of `AcceptAddrsBuf`.
+pub struct AcceptAddrs<'a> {
+    local: LPSOCKADDR,
+    local_len: c_int,
+    remote: LPSOCKADDR,
+    remote_len: c_int,
+    _data: &'a AcceptAddrsBuf,
+}
+
+struct WsaExtension {
+    guid: GUID,
+    val: AtomicUsize,
+}
+
+/// Additional methods for the `TcpStream` type in the standard library.
+pub trait TcpStreamExt {
+    /// Execute an overlapped read I/O operation on this TCP stream.
+    ///
+    /// This function will issue an overlapped I/O read (via `WSARecv`) on this
+    /// socket. The provided buffer will be filled in when the operation
+    /// completes and the given `OVERLAPPED` instance is used to track the
+    /// overlapped operation.
+    ///
+    /// If the operation succeeds, `Ok(Some(n))` is returned indicating how
+    /// many bytes were read. If the operation returns an error indicating that
+    /// the I/O is currently pending, `Ok(None)` is returned. Otherwise, the
+    /// error associated with the operation is returned and no overlapped
+    /// operation is enqueued.
+    ///
+    /// The number of bytes read will be returned as part of the completion
+    /// notification when the I/O finishes.
+    ///
+    /// # Unsafety
+    ///
+    /// This function is unsafe because the kernel requires that the `buf` and
+    /// `overlapped` pointers are valid until the end of the I/O operation. The
+    /// kernel also requires that `overlapped` is unique for this I/O operation
+    /// and is not in use for any other I/O.
+    ///
+    /// To safely use this function callers must ensure that these two input
+    /// pointers are valid until the I/O operation is completed, typically via
+    /// completion ports and waiting to receive the completion notification on
+    /// the port.
+    unsafe fn read_overlapped(
+        &self,
+        buf: &mut [u8],
+        overlapped: *mut OVERLAPPED,
+    ) -> io::Result<Option<usize>>;
+
+    /// Execute an overlapped write I/O operation on this TCP stream.
+    ///
+    /// This function will issue an overlapped I/O write (via `WSASend`) on this
+    /// socket. The provided buffer will be written when the operation completes
+    /// and the given `OVERLAPPED` instance is used to track the overlapped
+    /// operation.
+    ///
+    /// If the operation succeeds, `Ok(Some(n))` is returned where `n` is the
+    /// number of bytes that were written. If the operation returns an error
+    /// indicating that the I/O is currently pending, `Ok(None)` is returned.
+    /// Otherwise, the error associated with the operation is returned and no
+    /// overlapped operation is enqueued.
+    ///
+    /// The number of bytes written will be returned as part of the completion
+    /// notification when the I/O finishes.
+    ///
+    /// # Unsafety
+    ///
+    /// This function is unsafe because the kernel requires that the `buf` and
+    /// `overlapped` pointers are valid until the end of the I/O operation. The
+    /// kernel also requires that `overlapped` is unique for this I/O operation
+    /// and is not in use for any other I/O.
+    ///
+    /// To safely use this function callers must ensure that these two input
+    /// pointers are valid until the I/O operation is completed, typically via
+    /// completion ports and waiting to receive the completion notification on
+    /// the port.
+    unsafe fn write_overlapped(
+        &self,
+        buf: &[u8],
+        overlapped: *mut OVERLAPPED,
+    ) -> io::Result<Option<usize>>;
+
+    /// Attempt to consume the internal socket in this builder by executing an
+    /// overlapped connect operation.
+    ///
+    /// This function will issue a connect operation to the address specified on
+    /// the underlying socket, flagging it as an overlapped operation which will
+    /// complete asynchronously. If successful this function will return the
+    /// corresponding TCP stream.
+    ///
+    /// The `buf` argument provided is an initial buffer of data that should be
+    /// sent after the connection is initiated. It's acceptable to
+    /// pass an empty slice here.
+    ///
+    /// This function will also return whether the connect immediately
+    /// succeeded or not. If `None` is returned then the I/O operation is still
+    /// pending and will complete at a later date, and if `Some(bytes)` is
+    /// returned then that many bytes were transferred.
+    ///
+    /// Note that to succeed this requires that the underlying socket has
+    /// previously been bound via a call to `bind` to a local address.
+    ///
+    /// # Unsafety
+    ///
+    /// This function is unsafe because the kernel requires that the
+    /// `overlapped` and `buf` pointers to be  valid until the end of the I/O
+    /// operation. The kernel also requires that `overlapped` is unique for
+    /// this I/O operation and is not in use for any other I/O.
+    ///
+    /// To safely use this function callers must ensure that this pointer is
+    /// valid until the I/O operation is completed, typically via completion
+    /// ports and waiting to receive the completion notification on the port.
+    unsafe fn connect_overlapped(
+        &self,
+        addr: &SocketAddr,
+        buf: &[u8],
+        overlapped: *mut OVERLAPPED,
+    ) -> io::Result<Option<usize>>;
+
+    /// Once a `connect_overlapped` has finished, this function needs to be
+    /// called to finish the connect operation.
+    ///
+    /// Currently this just calls `setsockopt` with `SO_UPDATE_CONNECT_CONTEXT`
+    /// to ensure that further functions like `getpeername` and `getsockname`
+    /// work correctly.
+    fn connect_complete(&self) -> io::Result<()>;
+
+    /// Calls the `GetOverlappedResult` function to get the result of an
+    /// overlapped operation for this handle.
+    ///
+    /// This function takes the `OVERLAPPED` argument which must have been used
+    /// to initiate an overlapped I/O operation, and returns either the
+    /// successful number of bytes transferred during the operation or an error
+    /// if one occurred, along with the results of the `lpFlags` parameter of
+    /// the relevant operation, if applicable.
+    ///
+    /// # Unsafety
+    ///
+    /// This function is unsafe as `overlapped` must have previously been used
+    /// to execute an operation for this handle, and it must also be a valid
+    /// pointer to an `OVERLAPPED` instance.
+    ///
+    /// # Panics
+    ///
+    /// This function will panic
+    unsafe fn result(&self, overlapped: *mut OVERLAPPED) -> io::Result<(usize, u32)>;
+}
+
+/// Additional methods for the `UdpSocket` type in the standard library.
+pub trait UdpSocketExt {
+    /// Execute an overlapped receive I/O operation on this UDP socket.
+    ///
+    /// This function will issue an overlapped I/O read (via `WSARecvFrom`) on
+    /// this socket. The provided buffer will be filled in when the operation
+    /// completes, the source from where the data came from will be written to
+    /// `addr`, and the given `OVERLAPPED` instance is used to track the
+    /// overlapped operation.
+    ///
+    /// If the operation succeeds, `Ok(Some(n))` is returned where `n` is the
+    /// number of bytes that were read. If the operation returns an error
+    /// indicating that the I/O is currently pending, `Ok(None)` is returned.
+    /// Otherwise, the error associated with the operation is returned and no
+    /// overlapped operation is enqueued.
+    ///
+    /// The number of bytes read will be returned as part of the completion
+    /// notification when the I/O finishes.
+    ///
+    /// # Unsafety
+    ///
+    /// This function is unsafe because the kernel requires that the `buf`,
+    /// `addr`, and `overlapped` pointers are valid until the end of the I/O
+    /// operation. The kernel also requires that `overlapped` is unique for this
+    /// I/O operation and is not in use for any other I/O.
+    ///
+    /// To safely use this function callers must ensure that these two input
+    /// pointers are valid until the I/O operation is completed, typically via
+    /// completion ports and waiting to receive the completion notification on
+    /// the port.
+    unsafe fn recv_from_overlapped(
+        &self,
+        buf: &mut [u8],
+        addr: *mut SocketAddrBuf,
+        overlapped: *mut OVERLAPPED,
+    ) -> io::Result<Option<usize>>;
+
+    /// Execute an overlapped receive I/O operation on this UDP socket.
+    ///
+    /// This function will issue an overlapped I/O read (via `WSARecv`) on
+    /// this socket. The provided buffer will be filled in when the operation
+    /// completes, the source from where the data came from will be written to
+    /// `addr`, and the given `OVERLAPPED` instance is used to track the
+    /// overlapped operation.
+    ///
+    /// If the operation succeeds, `Ok(Some(n))` is returned where `n` is the
+    /// number of bytes that were read. If the operation returns an error
+    /// indicating that the I/O is currently pending, `Ok(None)` is returned.
+    /// Otherwise, the error associated with the operation is returned and no
+    /// overlapped operation is enqueued.
+    ///
+    /// The number of bytes read will be returned as part of the completion
+    /// notification when the I/O finishes.
+    ///
+    /// # Unsafety
+    ///
+    /// This function is unsafe because the kernel requires that the `buf`,
+    /// and `overlapped` pointers are valid until the end of the I/O
+    /// operation. The kernel also requires that `overlapped` is unique for this
+    /// I/O operation and is not in use for any other I/O.
+    ///
+    /// To safely use this function callers must ensure that these two input
+    /// pointers are valid until the I/O operation is completed, typically via
+    /// completion ports and waiting to receive the completion notification on
+    /// the port.
+    unsafe fn recv_overlapped(
+        &self,
+        buf: &mut [u8],
+        overlapped: *mut OVERLAPPED,
+    ) -> io::Result<Option<usize>>;
+
+    /// Execute an overlapped send I/O operation on this UDP socket.
+    ///
+    /// This function will issue an overlapped I/O write (via `WSASendTo`) on
+    /// this socket to the address specified by `addr`. The provided buffer will
+    /// be written when the operation completes and the given `OVERLAPPED`
+    /// instance is used to track the overlapped operation.
+    ///
+    /// If the operation succeeds, `Ok(Some(n0)` is returned where `n` byte
+    /// were written. If the operation returns an error indicating that the I/O
+    /// is currently pending, `Ok(None)` is returned. Otherwise, the error
+    /// associated with the operation is returned and no overlapped operation
+    /// is enqueued.
+    ///
+    /// The number of bytes written will be returned as part of the completion
+    /// notification when the I/O finishes.
+    ///
+    /// # Unsafety
+    ///
+    /// This function is unsafe because the kernel requires that the `buf` and
+    /// `overlapped` pointers are valid until the end of the I/O operation. The
+    /// kernel also requires that `overlapped` is unique for this I/O operation
+    /// and is not in use for any other I/O.
+    ///
+    /// To safely use this function callers must ensure that these two input
+    /// pointers are valid until the I/O operation is completed, typically via
+    /// completion ports and waiting to receive the completion notification on
+    /// the port.
+    unsafe fn send_to_overlapped(
+        &self,
+        buf: &[u8],
+        addr: &SocketAddr,
+        overlapped: *mut OVERLAPPED,
+    ) -> io::Result<Option<usize>>;
+
+    /// Execute an overlapped send I/O operation on this UDP socket.
+    ///
+    /// This function will issue an overlapped I/O write (via `WSASend`) on
+    /// this socket to the address it was previously connected to. The provided
+    /// buffer will be written when the operation completes and the given `OVERLAPPED`
+    /// instance is used to track the overlapped operation.
+    ///
+    /// If the operation succeeds, `Ok(Some(n0)` is returned where `n` byte
+    /// were written. If the operation returns an error indicating that the I/O
+    /// is currently pending, `Ok(None)` is returned. Otherwise, the error
+    /// associated with the operation is returned and no overlapped operation
+    /// is enqueued.
+    ///
+    /// The number of bytes written will be returned as part of the completion
+    /// notification when the I/O finishes.
+    ///
+    /// # Unsafety
+    ///
+    /// This function is unsafe because the kernel requires that the `buf` and
+    /// `overlapped` pointers are valid until the end of the I/O operation. The
+    /// kernel also requires that `overlapped` is unique for this I/O operation
+    /// and is not in use for any other I/O.
+    ///
+    /// To safely use this function callers must ensure that these two input
+    /// pointers are valid until the I/O operation is completed, typically via
+    /// completion ports and waiting to receive the completion notification on
+    /// the port.
+    unsafe fn send_overlapped(
+        &self,
+        buf: &[u8],
+        overlapped: *mut OVERLAPPED,
+    ) -> io::Result<Option<usize>>;
+
+    /// Calls the `GetOverlappedResult` function to get the result of an
+    /// overlapped operation for this handle.
+    ///
+    /// This function takes the `OVERLAPPED` argument which must have been used
+    /// to initiate an overlapped I/O operation, and returns either the
+    /// successful number of bytes transferred during the operation or an error
+    /// if one occurred, along with the results of the `lpFlags` parameter of
+    /// the relevant operation, if applicable.
+    ///
+    /// # Unsafety
+    ///
+    /// This function is unsafe as `overlapped` must have previously been used
+    /// to execute an operation for this handle, and it must also be a valid
+    /// pointer to an `OVERLAPPED` instance.
+    ///
+    /// # Panics
+    ///
+    /// This function will panic
+    unsafe fn result(&self, overlapped: *mut OVERLAPPED) -> io::Result<(usize, u32)>;
+}
+
+/// Additional methods for the `TcpListener` type in the standard library.
+pub trait TcpListenerExt {
+    /// Perform an accept operation on this listener, accepting a connection in
+    /// an overlapped fashion.
+    ///
+    /// This function will issue an I/O request to accept an incoming connection
+    /// with the specified overlapped instance. The `socket` provided must be a
+    /// configured but not bound or connected socket, and if successful this
+    /// will consume the internal socket of the builder to return a TCP stream.
+    ///
+    /// The `addrs` buffer provided will be filled in with the local and remote
+    /// addresses of the connection upon completion.
+    ///
+    /// If the accept succeeds immediately, `Ok(true)` is returned. If
+    /// the connect indicates that the I/O is currently pending, `Ok(false)` is
+    /// returned. Otherwise, the error associated with the operation is
+    /// returned and no overlapped operation is enqueued.
+    ///
+    /// # Unsafety
+    ///
+    /// This function is unsafe because the kernel requires that the
+    /// `addrs` and `overlapped` pointers are valid until the end of the I/O
+    /// operation. The kernel also requires that `overlapped` is unique for this
+    /// I/O operation and is not in use for any other I/O.
+    ///
+    /// To safely use this function callers must ensure that the pointers are
+    /// valid until the I/O operation is completed, typically via completion
+    /// ports and waiting to receive the completion notification on the port.
+    unsafe fn accept_overlapped(
+        &self,
+        socket: &TcpStream,
+        addrs: &mut AcceptAddrsBuf,
+        overlapped: *mut OVERLAPPED,
+    ) -> io::Result<bool>;
+
+    /// Once an `accept_overlapped` has finished, this function needs to be
+    /// called to finish the accept operation.
+    ///
+    /// Currently this just calls `setsockopt` with `SO_UPDATE_ACCEPT_CONTEXT`
+    /// to ensure that further functions like `getpeername` and `getsockname`
+    /// work correctly.
+    fn accept_complete(&self, socket: &TcpStream) -> io::Result<()>;
+
+    /// Calls the `GetOverlappedResult` function to get the result of an
+    /// overlapped operation for this handle.
+    ///
+    /// This function takes the `OVERLAPPED` argument which must have been used
+    /// to initiate an overlapped I/O operation, and returns either the
+    /// successful number of bytes transferred during the operation or an error
+    /// if one occurred, along with the results of the `lpFlags` parameter of
+    /// the relevant operation, if applicable.
+    ///
+    /// # Unsafety
+    ///
+    /// This function is unsafe as `overlapped` must have previously been used
+    /// to execute an operation for this handle, and it must also be a valid
+    /// pointer to an `OVERLAPPED` instance.
+    ///
+    /// # Panics
+    ///
+    /// This function will panic
+    unsafe fn result(&self, overlapped: *mut OVERLAPPED) -> io::Result<(usize, u32)>;
+}
+
+#[doc(hidden)]
+trait NetInt {
+    fn from_be(i: Self) -> Self;
+    fn to_be(&self) -> Self;
+}
+macro_rules! doit {
+    ($($t:ident)*) => ($(impl NetInt for $t {
+        fn from_be(i: Self) -> Self { <$t>::from_be(i) }
+        fn to_be(&self) -> Self { <$t>::to_be(*self) }
+    })*)
+}
+doit! { i8 i16 i32 i64 isize u8 u16 u32 u64 usize }
+
+// fn hton<I: NetInt>(i: I) -> I { i.to_be() }
+fn ntoh<I: NetInt>(i: I) -> I {
+    I::from_be(i)
+}
+
+fn last_err() -> io::Result<Option<usize>> {
+    let err = unsafe { WSAGetLastError() };
+    if err == WSA_IO_PENDING as i32 {
+        Ok(None)
+    } else {
+        Err(io::Error::from_raw_os_error(err))
+    }
+}
+
+fn cvt(i: c_int, size: DWORD) -> io::Result<Option<usize>> {
+    if i == SOCKET_ERROR {
+        last_err()
+    } else {
+        Ok(Some(size as usize))
+    }
+}
+
+/// A type with the same memory layout as `SOCKADDR`. Used in converting Rust level
+/// SocketAddr* types into their system representation. The benefit of this specific
+/// type over using `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: SOCKADDR_IN,
+    v6: SOCKADDR_IN6_LH,
+}
+
+impl SocketAddrCRepr {
+    pub(crate) fn as_ptr(&self) -> *const SOCKADDR {
+        self as *const _ as *const SOCKADDR
+    }
+}
+
+fn socket_addr_to_ptrs(addr: &SocketAddr) -> (SocketAddrCRepr, c_int) {
+    match *addr {
+        SocketAddr::V4(ref a) => {
+            let sin_addr = unsafe {
+                let mut s_un = mem::zeroed::<in_addr_S_un>();
+                *s_un.S_addr_mut() = u32::from_ne_bytes(a.ip().octets());
+                IN_ADDR { S_un: s_un }
+            };
+
+            let sockaddr_in = SOCKADDR_IN {
+                sin_family: AF_INET as ADDRESS_FAMILY,
+                sin_port: a.port().to_be(),
+                sin_addr,
+                sin_zero: [0; 8],
+            };
+
+            let sockaddr = SocketAddrCRepr { v4: sockaddr_in };
+            (sockaddr, mem::size_of::<SOCKADDR_IN>() as c_int)
+        }
+        SocketAddr::V6(ref a) => {
+            let sin6_addr = unsafe {
+                let mut u = mem::zeroed::<in6_addr_u>();
+                *u.Byte_mut() = a.ip().octets();
+                IN6_ADDR { u }
+            };
+            let u = unsafe {
+                let mut u = mem::zeroed::<SOCKADDR_IN6_LH_u>();
+                *u.sin6_scope_id_mut() = a.scope_id();
+                u
+            };
+
+            let sockaddr_in6 = SOCKADDR_IN6_LH {
+                sin6_family: AF_INET6 as ADDRESS_FAMILY,
+                sin6_port: a.port().to_be(),
+                sin6_addr,
+                sin6_flowinfo: a.flowinfo(),
+                u,
+            };
+
+            let sockaddr = SocketAddrCRepr { v6: sockaddr_in6 };
+            (sockaddr, mem::size_of::<SOCKADDR_IN6_LH>() as c_int)
+        }
+    }
+}
+
+unsafe fn ptrs_to_socket_addr(ptr: *const SOCKADDR, len: c_int) -> Option<SocketAddr> {
+    if (len as usize) < mem::size_of::<c_int>() {
+        return None;
+    }
+    match (*ptr).sa_family as i32 {
+        AF_INET if len as usize >= mem::size_of::<SOCKADDR_IN>() => {
+            let b = &*(ptr as *const SOCKADDR_IN);
+            let ip = ntoh(*b.sin_addr.S_un.S_addr());
+            let ip = Ipv4Addr::new(
+                (ip >> 24) as u8,
+                (ip >> 16) as u8,
+                (ip >> 8) as u8,
+                (ip >> 0) as u8,
+            );
+            Some(SocketAddr::V4(SocketAddrV4::new(ip, ntoh(b.sin_port))))
+        }
+        AF_INET6 if len as usize >= mem::size_of::<SOCKADDR_IN6_LH>() => {
+            let b = &*(ptr as *const SOCKADDR_IN6_LH);
+            let arr = b.sin6_addr.u.Byte();
+            let ip = Ipv6Addr::new(
+                ((arr[0] as u16) << 8) | (arr[1] as u16),
+                ((arr[2] as u16) << 8) | (arr[3] as u16),
+                ((arr[4] as u16) << 8) | (arr[5] as u16),
+                ((arr[6] as u16) << 8) | (arr[7] as u16),
+                ((arr[8] as u16) << 8) | (arr[9] as u16),
+                ((arr[10] as u16) << 8) | (arr[11] as u16),
+                ((arr[12] as u16) << 8) | (arr[13] as u16),
+                ((arr[14] as u16) << 8) | (arr[15] as u16),
+            );
+            let addr = SocketAddrV6::new(
+                ip,
+                ntoh(b.sin6_port),
+                ntoh(b.sin6_flowinfo),
+                ntoh(*b.u.sin6_scope_id()),
+            );
+            Some(SocketAddr::V6(addr))
+        }
+        _ => None,
+    }
+}
+
+unsafe fn slice2buf(slice: &[u8]) -> WSABUF {
+    WSABUF {
+        len: cmp::min(slice.len(), <u_long>::max_value() as usize) as u_long,
+        buf: slice.as_ptr() as *mut _,
+    }
+}
+
+unsafe fn result(socket: SOCKET, overlapped: *mut OVERLAPPED) -> io::Result<(usize, u32)> {
+    let mut transferred = 0;
+    let mut flags = 0;
+    let r = WSAGetOverlappedResult(socket, overlapped, &mut transferred, FALSE, &mut flags);
+    if r == 0 {
+        Err(io::Error::last_os_error())
+    } else {
+        Ok((transferred as usize, flags))
+    }
+}
+
+impl TcpStreamExt for TcpStream {
+    unsafe fn read_overlapped(
+        &self,
+        buf: &mut [u8],
+        overlapped: *mut OVERLAPPED,
+    ) -> io::Result<Option<usize>> {
+        let mut buf = slice2buf(buf);
+        let mut flags = 0;
+        let mut bytes_read: DWORD = 0;
+        let r = WSARecv(
+            self.as_raw_socket() as SOCKET,
+            &mut buf,
+            1,
+            &mut bytes_read,
+            &mut flags,
+            overlapped,
+            None,
+        );
+        cvt(r, bytes_read)
+    }
+
+    unsafe fn write_overlapped(
+        &self,
+        buf: &[u8],
+        overlapped: *mut OVERLAPPED,
+    ) -> io::Result<Option<usize>> {
+        let mut buf = slice2buf(buf);
+        let mut bytes_written = 0;
+
+        // Note here that we capture the number of bytes written. The
+        // documentation on MSDN, however, states:
+        //
+        // > Use NULL for this parameter if the lpOverlapped parameter is not
+        // > NULL to avoid potentially erroneous results. This parameter can be
+        // > NULL only if the lpOverlapped parameter is not NULL.
+        //
+        // If we're not passing a null overlapped pointer here, then why are we
+        // then capturing the number of bytes! Well so it turns out that this is
+        // clearly faster to learn the bytes here rather than later calling
+        // `WSAGetOverlappedResult`, and in practice almost all implementations
+        // use this anyway [1].
+        //
+        // As a result we use this to and report back the result.
+        //
+        // [1]: https://github.com/carllerche/mio/pull/520#issuecomment-273983823
+        let r = WSASend(
+            self.as_raw_socket() as SOCKET,
+            &mut buf,
+            1,
+            &mut bytes_written,
+            0,
+            overlapped,
+            None,
+        );
+        cvt(r, bytes_written)
+    }
+
+    unsafe fn connect_overlapped(
+        &self,
+        addr: &SocketAddr,
+        buf: &[u8],
+        overlapped: *mut OVERLAPPED,
+    ) -> io::Result<Option<usize>> {
+        connect_overlapped(self.as_raw_socket() as SOCKET, addr, buf, overlapped)
+    }
+
+    fn connect_complete(&self) -> io::Result<()> {
+        const SO_UPDATE_CONNECT_CONTEXT: c_int = 0x7010;
+        let result = unsafe {
+            setsockopt(
+                self.as_raw_socket() as SOCKET,
+                SOL_SOCKET,
+                SO_UPDATE_CONNECT_CONTEXT,
+                0 as *const _,
+                0,
+            )
+        };
+        if result == 0 {
+            Ok(())
+        } else {
+            Err(io::Error::last_os_error())
+        }
+    }
+
+    unsafe fn result(&self, overlapped: *mut OVERLAPPED) -> io::Result<(usize, u32)> {
+        result(self.as_raw_socket() as SOCKET, overlapped)
+    }
+}
+
+unsafe fn connect_overlapped(
+    socket: SOCKET,
+    addr: &SocketAddr,
+    buf: &[u8],
+    overlapped: *mut OVERLAPPED,
+) -> io::Result<Option<usize>> {
+    static CONNECTEX: WsaExtension = WsaExtension {
+        guid: GUID {
+            Data1: 0x25a207b9,
+            Data2: 0xddf3,
+            Data3: 0x4660,
+            Data4: [0x8e, 0xe9, 0x76, 0xe5, 0x8c, 0x74, 0x06, 0x3e],
+        },
+        val: AtomicUsize::new(0),
+    };
+    type ConnectEx = unsafe extern "system" fn(
+        SOCKET,
+        *const SOCKADDR,
+        c_int,
+        PVOID,
+        DWORD,
+        LPDWORD,
+        LPOVERLAPPED,
+    ) -> BOOL;
+
+    let ptr = CONNECTEX.get(socket)?;
+    assert!(ptr != 0);
+    let connect_ex = mem::transmute::<_, ConnectEx>(ptr);
+
+    let (addr_buf, addr_len) = socket_addr_to_ptrs(addr);
+    let mut bytes_sent: DWORD = 0;
+    let r = connect_ex(
+        socket,
+        addr_buf.as_ptr(),
+        addr_len,
+        buf.as_ptr() as *mut _,
+        buf.len() as u32,
+        &mut bytes_sent,
+        overlapped,
+    );
+    if r == TRUE {
+        Ok(Some(bytes_sent as usize))
+    } else {
+        last_err()
+    }
+}
+
+impl UdpSocketExt for UdpSocket {
+    unsafe fn recv_from_overlapped(
+        &self,
+        buf: &mut [u8],
+        addr: *mut SocketAddrBuf,
+        overlapped: *mut OVERLAPPED,
+    ) -> io::Result<Option<usize>> {
+        let mut buf = slice2buf(buf);
+        let mut flags = 0;
+        let mut received_bytes: DWORD = 0;
+        let r = WSARecvFrom(
+            self.as_raw_socket() as SOCKET,
+            &mut buf,
+            1,
+            &mut received_bytes,
+            &mut flags,
+            &mut (*addr).buf as *mut _ as *mut _,
+            &mut (*addr).len,
+            overlapped,
+            None,
+        );
+        cvt(r, received_bytes)
+    }
+
+    unsafe fn recv_overlapped(
+        &self,
+        buf: &mut [u8],
+        overlapped: *mut OVERLAPPED,
+    ) -> io::Result<Option<usize>> {
+        let mut buf = slice2buf(buf);
+        let mut flags = 0;
+        let mut received_bytes: DWORD = 0;
+        let r = WSARecv(
+            self.as_raw_socket() as SOCKET,
+            &mut buf,
+            1,
+            &mut received_bytes,
+            &mut flags,
+            overlapped,
+            None,
+        );
+        cvt(r, received_bytes)
+    }
+
+    unsafe fn send_to_overlapped(
+        &self,
+        buf: &[u8],
+        addr: &SocketAddr,
+        overlapped: *mut OVERLAPPED,
+    ) -> io::Result<Option<usize>> {
+        let (addr_buf, addr_len) = socket_addr_to_ptrs(addr);
+        let mut buf = slice2buf(buf);
+        let mut sent_bytes = 0;
+        let r = WSASendTo(
+            self.as_raw_socket() as SOCKET,
+            &mut buf,
+            1,
+            &mut sent_bytes,
+            0,
+            addr_buf.as_ptr() as *const _,
+            addr_len,
+            overlapped,
+            None,
+        );
+        cvt(r, sent_bytes)
+    }
+
+    unsafe fn send_overlapped(
+        &self,
+        buf: &[u8],
+        overlapped: *mut OVERLAPPED,
+    ) -> io::Result<Option<usize>> {
+        let mut buf = slice2buf(buf);
+        let mut sent_bytes = 0;
+        let r = WSASend(
+            self.as_raw_socket() as SOCKET,
+            &mut buf,
+            1,
+            &mut sent_bytes,
+            0,
+            overlapped,
+            None,
+        );
+        cvt(r, sent_bytes)
+    }
+
+    unsafe fn result(&self, overlapped: *mut OVERLAPPED) -> io::Result<(usize, u32)> {
+        result(self.as_raw_socket() as SOCKET, overlapped)
+    }
+}
+
+impl TcpListenerExt for TcpListener {
+    unsafe fn accept_overlapped(
+        &self,
+        socket: &TcpStream,
+        addrs: &mut AcceptAddrsBuf,
+        overlapped: *mut OVERLAPPED,
+    ) -> io::Result<bool> {
+        static ACCEPTEX: WsaExtension = WsaExtension {
+            guid: GUID {
+                Data1: 0xb5367df1,
+                Data2: 0xcbac,
+                Data3: 0x11cf,
+                Data4: [0x95, 0xca, 0x00, 0x80, 0x5f, 0x48, 0xa1, 0x92],
+            },
+            val: AtomicUsize::new(0),
+        };
+        type AcceptEx = unsafe extern "system" fn(
+            SOCKET,
+            SOCKET,
+            PVOID,
+            DWORD,
+            DWORD,
+            DWORD,
+            LPDWORD,
+            LPOVERLAPPED,
+        ) -> BOOL;
+
+        let ptr = ACCEPTEX.get(self.as_raw_socket() as SOCKET)?;
+        assert!(ptr != 0);
+        let accept_ex = mem::transmute::<_, AcceptEx>(ptr);
+
+        let mut bytes = 0;
+        let (a, b, c, d) = (*addrs).args();
+        let r = accept_ex(
+            self.as_raw_socket() as SOCKET,
+            socket.as_raw_socket() as SOCKET,
+            a,
+            b,
+            c,
+            d,
+            &mut bytes,
+            overlapped,
+        );
+        let succeeded = if r == TRUE {
+            true
+        } else {
+            last_err()?;
+            false
+        };
+        Ok(succeeded)
+    }
+
+    fn accept_complete(&self, socket: &TcpStream) -> io::Result<()> {
+        const SO_UPDATE_ACCEPT_CONTEXT: c_int = 0x700B;
+        let me = self.as_raw_socket();
+        let result = unsafe {
+            setsockopt(
+                socket.as_raw_socket() as SOCKET,
+                SOL_SOCKET,
+                SO_UPDATE_ACCEPT_CONTEXT,
+                &me as *const _ as *const _,
+                mem::size_of_val(&me) as c_int,
+            )
+        };
+        if result == 0 {
+            Ok(())
+        } else {
+            Err(io::Error::last_os_error())
+        }
+    }
+
+    unsafe fn result(&self, overlapped: *mut OVERLAPPED) -> io::Result<(usize, u32)> {
+        result(self.as_raw_socket() as SOCKET, overlapped)
+    }
+}
+
+impl SocketAddrBuf {
+    /// Creates a new blank socket address buffer.
+    ///
+    /// This should be used before a call to `recv_from_overlapped` overlapped
+    /// to create an instance to pass down.
+    pub fn new() -> SocketAddrBuf {
+        SocketAddrBuf {
+            buf: unsafe { mem::zeroed() },
+            len: mem::size_of::<SOCKADDR_STORAGE>() as c_int,
+        }
+    }
+
+    /// Parses this buffer to return a standard socket address.
+    ///
+    /// This function should be called after the buffer has been filled in with
+    /// a call to `recv_from_overlapped` being completed. It will interpret the
+    /// address filled in and return the standard socket address type.
+    ///
+    /// If an error is encountered then `None` is returned.
+    pub fn to_socket_addr(&self) -> Option<SocketAddr> {
+        unsafe { ptrs_to_socket_addr(&self.buf as *const _ as *const _, self.len) }
+    }
+}
+
+static GETACCEPTEXSOCKADDRS: WsaExtension = WsaExtension {
+    guid: GUID {
+        Data1: 0xb5367df2,
+        Data2: 0xcbac,
+        Data3: 0x11cf,
+        Data4: [0x95, 0xca, 0x00, 0x80, 0x5f, 0x48, 0xa1, 0x92],
+    },
+    val: AtomicUsize::new(0),
+};
+type GetAcceptExSockaddrs = unsafe extern "system" fn(
+    PVOID,
+    DWORD,
+    DWORD,
+    DWORD,
+    *mut LPSOCKADDR,
+    LPINT,
+    *mut LPSOCKADDR,
+    LPINT,
+);
+
+impl AcceptAddrsBuf {
+    /// Creates a new blank buffer ready to be passed to a call to
+    /// `accept_overlapped`.
+    pub fn new() -> AcceptAddrsBuf {
+        unsafe { mem::zeroed() }
+    }
+
+    /// Parses the data contained in this address buffer, returning the parsed
+    /// result if successful.
+    ///
+    /// This function can be called after a call to `accept_overlapped` has
+    /// succeeded to parse out the data that was written in.
+    pub fn parse(&self, socket: &TcpListener) -> io::Result<AcceptAddrs> {
+        let mut ret = AcceptAddrs {
+            local: 0 as *mut _,
+            local_len: 0,
+            remote: 0 as *mut _,
+            remote_len: 0,
+            _data: self,
+        };
+        let ptr = GETACCEPTEXSOCKADDRS.get(socket.as_raw_socket() as SOCKET)?;
+        assert!(ptr != 0);
+        unsafe {
+            let get_sockaddrs = mem::transmute::<_, GetAcceptExSockaddrs>(ptr);
+            let (a, b, c, d) = self.args();
+            get_sockaddrs(
+                a,
+                b,
+                c,
+                d,
+                &mut ret.local,
+                &mut ret.local_len,
+                &mut ret.remote,
+                &mut ret.remote_len,
+            );
+            Ok(ret)
+        }
+    }
+
+    fn args(&self) -> (PVOID, DWORD, DWORD, DWORD) {
+        let remote_offset = unsafe { &(*(0 as *const AcceptAddrsBuf)).remote as *const _ as usize };
+        (
+            self as *const _ as *mut _,
+            0,
+            remote_offset as DWORD,
+            (mem::size_of_val(self) - remote_offset) as DWORD,
+        )
+    }
+}
+
+impl<'a> AcceptAddrs<'a> {
+    /// Returns the local socket address contained in this buffer.
+    pub fn local(&self) -> Option<SocketAddr> {
+        unsafe { ptrs_to_socket_addr(self.local, self.local_len) }
+    }
+
+    /// Returns the remote socket address contained in this buffer.
+    pub fn remote(&self) -> Option<SocketAddr> {
+        unsafe { ptrs_to_socket_addr(self.remote, self.remote_len) }
+    }
+}
+
+impl WsaExtension {
+    fn get(&self, socket: SOCKET) -> io::Result<usize> {
+        let prev = self.val.load(Ordering::SeqCst);
+        if prev != 0 && !cfg!(debug_assertions) {
+            return Ok(prev);
+        }
+        let mut ret = 0 as usize;
+        let mut bytes = 0;
+        let r = unsafe {
+            WSAIoctl(
+                socket,
+                SIO_GET_EXTENSION_FUNCTION_POINTER,
+                &self.guid as *const _ as *mut _,
+                mem::size_of_val(&self.guid) as DWORD,
+                &mut ret as *mut _ as *mut _,
+                mem::size_of_val(&ret) as DWORD,
+                &mut bytes,
+                0 as *mut _,
+                None,
+            )
+        };
+        cvt(r, 0).map(|_| {
+            debug_assert_eq!(bytes as usize, mem::size_of_val(&ret));
+            debug_assert!(prev == 0 || prev == ret);
+            self.val.store(ret, Ordering::SeqCst);
+            ret
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::io::prelude::*;
+    use std::net::{
+        IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV6, TcpListener, TcpStream, UdpSocket,
+    };
+    use std::slice;
+    use std::thread;
+
+    use socket2::{Domain, Socket, Type};
+
+    use crate::iocp::CompletionPort;
+    use crate::net::{AcceptAddrsBuf, TcpListenerExt};
+    use crate::net::{SocketAddrBuf, TcpStreamExt, UdpSocketExt};
+    use crate::Overlapped;
+
+    fn each_ip(f: &mut dyn FnMut(SocketAddr)) {
+        f(t!("127.0.0.1:0".parse()));
+        f(t!("[::1]:0".parse()));
+    }
+
+    #[test]
+    fn tcp_read() {
+        each_ip(&mut |addr| {
+            let l = t!(TcpListener::bind(addr));
+            let addr = t!(l.local_addr());
+            let t = thread::spawn(move || {
+                let mut a = t!(l.accept()).0;
+                t!(a.write_all(&[1, 2, 3]));
+            });
+
+            let cp = t!(CompletionPort::new(1));
+            let s = t!(TcpStream::connect(addr));
+            t!(cp.add_socket(1, &s));
+
+            let mut b = [0; 10];
+            let a = Overlapped::zero();
+            unsafe {
+                t!(s.read_overlapped(&mut b, a.raw()));
+            }
+            let status = t!(cp.get(None));
+            assert_eq!(status.bytes_transferred(), 3);
+            assert_eq!(status.token(), 1);
+            assert_eq!(status.overlapped(), a.raw());
+            assert_eq!(&b[0..3], &[1, 2, 3]);
+
+            t!(t.join());
+        })
+    }
+
+    #[test]
+    fn tcp_write() {
+        each_ip(&mut |addr| {
+            let l = t!(TcpListener::bind(addr));
+            let addr = t!(l.local_addr());
+            let t = thread::spawn(move || {
+                let mut a = t!(l.accept()).0;
+                let mut b = [0; 10];
+                let n = t!(a.read(&mut b));
+                assert_eq!(n, 3);
+                assert_eq!(&b[0..3], &[1, 2, 3]);
+            });
+
+            let cp = t!(CompletionPort::new(1));
+            let s = t!(TcpStream::connect(addr));
+            t!(cp.add_socket(1, &s));
+
+            let b = [1, 2, 3];
+            let a = Overlapped::zero();
+            unsafe {
+                t!(s.write_overlapped(&b, a.raw()));
+            }
+            let status = t!(cp.get(None));
+            assert_eq!(status.bytes_transferred(), 3);
+            assert_eq!(status.token(), 1);
+            assert_eq!(status.overlapped(), a.raw());
+
+            t!(t.join());
+        })
+    }
+
+    #[test]
+    fn tcp_connect() {
+        each_ip(&mut |addr_template| {
+            let l = t!(TcpListener::bind(addr_template));
+            let addr = t!(l.local_addr());
+            let t = thread::spawn(move || {
+                t!(l.accept());
+            });
+
+            let cp = t!(CompletionPort::new(1));
+            let domain = Domain::for_address(addr);
+            let socket = t!(Socket::new(domain, Type::STREAM, None));
+            t!(socket.bind(&addr_template.into()));
+            let socket = TcpStream::from(socket);
+            t!(cp.add_socket(1, &socket));
+
+            let a = Overlapped::zero();
+            unsafe {
+                t!(socket.connect_overlapped(&addr, &[], a.raw()));
+            }
+            let status = t!(cp.get(None));
+            assert_eq!(status.bytes_transferred(), 0);
+            assert_eq!(status.token(), 1);
+            assert_eq!(status.overlapped(), a.raw());
+            t!(socket.connect_complete());
+
+            t!(t.join());
+        })
+    }
+
+    #[test]
+    fn udp_recv_from() {
+        each_ip(&mut |addr| {
+            let a = t!(UdpSocket::bind(addr));
+            let b = t!(UdpSocket::bind(addr));
+            let a_addr = t!(a.local_addr());
+            let b_addr = t!(b.local_addr());
+            let t = thread::spawn(move || {
+                t!(a.send_to(&[1, 2, 3], b_addr));
+            });
+
+            let cp = t!(CompletionPort::new(1));
+            t!(cp.add_socket(1, &b));
+
+            let mut buf = [0; 10];
+            let a = Overlapped::zero();
+            let mut addr = SocketAddrBuf::new();
+            unsafe {
+                t!(b.recv_from_overlapped(&mut buf, &mut addr, a.raw()));
+            }
+            let status = t!(cp.get(None));
+            assert_eq!(status.bytes_transferred(), 3);
+            assert_eq!(status.token(), 1);
+            assert_eq!(status.overlapped(), a.raw());
+            assert_eq!(&buf[..3], &[1, 2, 3]);
+            assert_eq!(addr.to_socket_addr(), Some(a_addr));
+
+            t!(t.join());
+        })
+    }
+
+    #[test]
+    fn udp_recv() {
+        each_ip(&mut |addr| {
+            let a = t!(UdpSocket::bind(addr));
+            let b = t!(UdpSocket::bind(addr));
+            let a_addr = t!(a.local_addr());
+            let b_addr = t!(b.local_addr());
+            assert!(b.connect(a_addr).is_ok());
+            assert!(a.connect(b_addr).is_ok());
+            let t = thread::spawn(move || {
+                t!(a.send_to(&[1, 2, 3], b_addr));
+            });
+
+            let cp = t!(CompletionPort::new(1));
+            t!(cp.add_socket(1, &b));
+
+            let mut buf = [0; 10];
+            let a = Overlapped::zero();
+            unsafe {
+                t!(b.recv_overlapped(&mut buf, a.raw()));
+            }
+            let status = t!(cp.get(None));
+            assert_eq!(status.bytes_transferred(), 3);
+            assert_eq!(status.token(), 1);
+            assert_eq!(status.overlapped(), a.raw());
+            assert_eq!(&buf[..3], &[1, 2, 3]);
+
+            t!(t.join());
+        })
+    }
+
+    #[test]
+    fn udp_send_to() {
+        each_ip(&mut |addr| {
+            let a = t!(UdpSocket::bind(addr));
+            let b = t!(UdpSocket::bind(addr));
+            let a_addr = t!(a.local_addr());
+            let b_addr = t!(b.local_addr());
+            let t = thread::spawn(move || {
+                let mut b = [0; 100];
+                let (n, addr) = t!(a.recv_from(&mut b));
+                assert_eq!(n, 3);
+                assert_eq!(addr, b_addr);
+                assert_eq!(&b[..3], &[1, 2, 3]);
+            });
+
+            let cp = t!(CompletionPort::new(1));
+            t!(cp.add_socket(1, &b));
+
+            let a = Overlapped::zero();
+            unsafe {
+                t!(b.send_to_overlapped(&[1, 2, 3], &a_addr, a.raw()));
+            }
+            let status = t!(cp.get(None));
+            assert_eq!(status.bytes_transferred(), 3);
+            assert_eq!(status.token(), 1);
+            assert_eq!(status.overlapped(), a.raw());
+
+            t!(t.join());
+        })
+    }
+
+    #[test]
+    fn udp_send() {
+        each_ip(&mut |addr| {
+            let a = t!(UdpSocket::bind(addr));
+            let b = t!(UdpSocket::bind(addr));
+            let a_addr = t!(a.local_addr());
+            let b_addr = t!(b.local_addr());
+            assert!(b.connect(a_addr).is_ok());
+            assert!(a.connect(b_addr).is_ok());
+            let t = thread::spawn(move || {
+                let mut b = [0; 100];
+                let (n, addr) = t!(a.recv_from(&mut b));
+                assert_eq!(n, 3);
+                assert_eq!(addr, b_addr);
+                assert_eq!(&b[..3], &[1, 2, 3]);
+            });
+
+            let cp = t!(CompletionPort::new(1));
+            t!(cp.add_socket(1, &b));
+
+            let a = Overlapped::zero();
+            unsafe {
+                t!(b.send_overlapped(&[1, 2, 3], a.raw()));
+            }
+            let status = t!(cp.get(None));
+            assert_eq!(status.bytes_transferred(), 3);
+            assert_eq!(status.token(), 1);
+            assert_eq!(status.overlapped(), a.raw());
+
+            t!(t.join());
+        })
+    }
+
+    #[test]
+    fn tcp_accept() {
+        each_ip(&mut |addr_template| {
+            let l = t!(TcpListener::bind(addr_template));
+            let addr = t!(l.local_addr());
+            let t = thread::spawn(move || {
+                let socket = t!(TcpStream::connect(addr));
+                (socket.local_addr().unwrap(), socket.peer_addr().unwrap())
+            });
+
+            let cp = t!(CompletionPort::new(1));
+            let domain = Domain::for_address(addr);
+            let socket = TcpStream::from(t!(Socket::new(domain, Type::STREAM, None)));
+            t!(cp.add_socket(1, &l));
+
+            let a = Overlapped::zero();
+            let mut addrs = AcceptAddrsBuf::new();
+            unsafe {
+                t!(l.accept_overlapped(&socket, &mut addrs, a.raw()));
+            }
+            let status = t!(cp.get(None));
+            assert_eq!(status.bytes_transferred(), 0);
+            assert_eq!(status.token(), 1);
+            assert_eq!(status.overlapped(), a.raw());
+            t!(l.accept_complete(&socket));
+
+            let (remote, local) = t!(t.join());
+            let addrs = addrs.parse(&l).unwrap();
+            assert_eq!(addrs.local(), Some(local));
+            assert_eq!(addrs.remote(), Some(remote));
+        })
+    }
+
+    #[test]
+    fn sockaddr_convert_4() {
+        let addr = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(3, 4, 5, 6)), 0xabcd);
+        let (raw_addr, addr_len) = super::socket_addr_to_ptrs(&addr);
+        assert_eq!(addr_len, 16);
+        let addr_bytes =
+            unsafe { slice::from_raw_parts(raw_addr.as_ptr() as *const u8, addr_len as usize) };
+        assert_eq!(
+            addr_bytes,
+            &[2, 0, 0xab, 0xcd, 3, 4, 5, 6, 0, 0, 0, 0, 0, 0, 0, 0]
+        );
+    }
+
+    #[test]
+    fn sockaddr_convert_v6() {
+        let port = 0xabcd;
+        let flowinfo = 0x12345678;
+        let scope_id = 0x87654321;
+        let addr = SocketAddr::V6(SocketAddrV6::new(
+            Ipv6Addr::new(
+                0x0102, 0x0304, 0x0506, 0x0708, 0x090a, 0x0b0c, 0x0d0e, 0x0f10,
+            ),
+            port,
+            flowinfo,
+            scope_id,
+        ));
+        let (raw_addr, addr_len) = super::socket_addr_to_ptrs(&addr);
+        assert_eq!(addr_len, 28);
+        let addr_bytes =
+            unsafe { slice::from_raw_parts(raw_addr.as_ptr() as *const u8, addr_len as usize) };
+        assert_eq!(
+            addr_bytes,
+            &[
+                23, 0, // AF_INET6
+                0xab, 0xcd, // Port
+                0x78, 0x56, 0x34, 0x12, // flowinfo
+                0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e,
+                0x0f, 0x10, // IP
+                0x21, 0x43, 0x65, 0x87, // scope_id
+            ]
+        );
+    }
+}