chore: add vendor directory

1 files changed, 745 insertions, 0 deletions

diff --git a/vendor/socket2/src/lib.rs b/vendor/socket2/src/lib.rs
new file mode 100644
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--- /dev/null
+++ b/vendor/socket2/src/lib.rs
@@ -0,0 +1,745 @@
+// Copyright 2015 The Rust Project Developers.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Utilities for creating and using sockets.
+//!
+//! The goal of this crate is to create and use a socket using advanced
+//! configuration options (those that are not available in the types in the
+//! standard library) without using any unsafe code.
+//!
+//! This crate provides as direct as possible access to the system's
+//! functionality for sockets, this means little effort to provide
+//! cross-platform utilities. It is up to the user to know how to use sockets
+//! when using this crate. *If you don't know how to create a socket using
+//! libc/system calls then this crate is not for you*. Most, if not all,
+//! functions directly relate to the equivalent system call with no error
+//! handling applied, so no handling errors such as [`EINTR`]. As a result using
+//! this crate can be a little wordy, but it should give you maximal flexibility
+//! over configuration of sockets.
+//!
+//! [`EINTR`]: std::io::ErrorKind::Interrupted
+//!
+//! # Examples
+//!
+//! ```no_run
+//! # fn main() -> std::io::Result<()> {
+//! use std::net::{SocketAddr, TcpListener};
+//! use socket2::{Socket, Domain, Type};
+//!
+//! // Create a TCP listener bound to two addresses.
+//! let socket = Socket::new(Domain::IPV6, Type::STREAM, None)?;
+//!
+//! socket.set_only_v6(false)?;
+//! let address: SocketAddr = "[::1]:12345".parse().unwrap();
+//! socket.bind(&address.into())?;
+//! socket.listen(128)?;
+//!
+//! let listener: TcpListener = socket.into();
+//! // ...
+//! # drop(listener);
+//! # Ok(()) }
+//! ```
+//!
+//! ## Features
+//!
+//! This crate has a single feature `all`, which enables all functions even ones
+//! that are not available on all OSs.
+
+#![deny(missing_docs, missing_debug_implementations, rust_2018_idioms)]
+// Show required OS/features on docs.rs.
+#![cfg_attr(docsrs, feature(doc_cfg))]
+// Disallow warnings when running tests.
+#![cfg_attr(test, deny(warnings))]
+// Disallow warnings in examples.
+#![doc(test(attr(deny(warnings))))]
+
+use std::fmt;
+#[cfg(not(target_os = "redox"))]
+use std::io::IoSlice;
+#[cfg(not(target_os = "redox"))]
+use std::marker::PhantomData;
+#[cfg(not(target_os = "redox"))]
+use std::mem;
+use std::mem::MaybeUninit;
+use std::net::SocketAddr;
+use std::ops::{Deref, DerefMut};
+use std::time::Duration;
+
+/// Macro to implement `fmt::Debug` for a type, printing the constant names
+/// rather than a number.
+///
+/// Note this is used in the `sys` module and thus must be defined before
+/// defining the modules.
+macro_rules! impl_debug {
+    (
+        // Type name for which to implement `fmt::Debug`.
+        $type: path,
+        $(
+            $(#[$target: meta])*
+            // The flag(s) to check.
+            // Need to specific the libc crate because Windows doesn't use
+            // `libc` but `windows_sys`.
+            $libc: ident :: $flag: ident
+        ),+ $(,)*
+    ) => {
+        impl std::fmt::Debug for $type {
+            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+                let string = match self.0 {
+                    $(
+                        $(#[$target])*
+                        $libc :: $flag => stringify!($flag),
+                    )+
+                    n => return write!(f, "{n}"),
+                };
+                f.write_str(string)
+            }
+        }
+    };
+}
+
+/// Macro to convert from one network type to another.
+macro_rules! from {
+    ($from: ty, $for: ty) => {
+        impl From<$from> for $for {
+            fn from(socket: $from) -> $for {
+                #[cfg(unix)]
+                unsafe {
+                    <$for>::from_raw_fd(socket.into_raw_fd())
+                }
+                #[cfg(windows)]
+                unsafe {
+                    <$for>::from_raw_socket(socket.into_raw_socket())
+                }
+            }
+        }
+    };
+}
+
+/// Link to online documentation for (almost) all supported OSs.
+#[rustfmt::skip]
+macro_rules! man_links {
+    // Links to all OSs.
+    ($syscall: tt ( $section: tt ) ) => {
+        concat!(
+            man_links!(__ intro),
+            man_links!(__ unix $syscall($section)),
+            man_links!(__ windows $syscall($section)),
+        )
+    };
+    // Links to Unix-like OSs.
+    (unix: $syscall: tt ( $section: tt ) ) => {
+        concat!(
+            man_links!(__ intro),
+            man_links!(__ unix $syscall($section)),
+        )
+    };
+    // Links to Windows only.
+    (windows: $syscall: tt ( $section: tt ) ) => {
+        concat!(
+            man_links!(__ intro),
+            man_links!(__ windows $syscall($section)),
+        )
+    };
+    // Internals.
+    (__ intro) => {
+        "\n\nAdditional documentation can be found in manual of the OS:\n\n"
+    };
+    // List for Unix-like OSs.
+    (__ unix $syscall: tt ( $section: tt ) ) => {
+        concat!(
+            " * DragonFly BSD: <https://man.dragonflybsd.org/?command=", stringify!($syscall), "&section=", stringify!($section), ">\n",
+            " * FreeBSD: <https://www.freebsd.org/cgi/man.cgi?query=", stringify!($syscall), "&sektion=", stringify!($section), ">\n",
+            " * Linux: <https://man7.org/linux/man-pages/man", stringify!($section), "/", stringify!($syscall), ".", stringify!($section), ".html>\n",
+            " * macOS: <https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/", stringify!($syscall), ".", stringify!($section), ".html> (archived, actually for iOS)\n",
+            " * NetBSD: <https://man.netbsd.org/", stringify!($syscall), ".", stringify!($section), ">\n",
+            " * OpenBSD: <https://man.openbsd.org/", stringify!($syscall), ".", stringify!($section), ">\n",
+            " * iOS: <https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/", stringify!($syscall), ".", stringify!($section), ".html> (archived)\n",
+            " * illumos: <https://illumos.org/man/3SOCKET/", stringify!($syscall), ">\n",
+        )
+    };
+    // List for Window (so just Windows).
+    (__ windows $syscall: tt ( $section: tt ) ) => {
+        concat!(
+            " * Windows: <https://docs.microsoft.com/en-us/windows/win32/api/winsock2/nf-winsock2-", stringify!($syscall), ">\n",
+        )
+    };
+}
+
+mod sockaddr;
+mod socket;
+mod sockref;
+
+#[cfg_attr(unix, path = "sys/unix.rs")]
+#[cfg_attr(windows, path = "sys/windows.rs")]
+mod sys;
+
+#[cfg(not(any(windows, unix)))]
+compile_error!("Socket2 doesn't support the compile target");
+
+use sys::c_int;
+
+pub use sockaddr::SockAddr;
+pub use socket::Socket;
+pub use sockref::SockRef;
+
+#[cfg(not(any(
+    target_os = "haiku",
+    target_os = "illumos",
+    target_os = "netbsd",
+    target_os = "redox",
+    target_os = "solaris",
+)))]
+pub use socket::InterfaceIndexOrAddress;
+
+/// Specification of the communication domain for a socket.
+///
+/// This is a newtype wrapper around an integer which provides a nicer API in
+/// addition to an injection point for documentation. Convenience constants such
+/// as [`Domain::IPV4`], [`Domain::IPV6`], etc, are provided to avoid reaching
+/// into libc for various constants.
+///
+/// This type is freely interconvertible with C's `int` type, however, if a raw
+/// value needs to be provided.
+#[derive(Copy, Clone, Eq, PartialEq)]
+pub struct Domain(c_int);
+
+impl Domain {
+    /// Domain for IPv4 communication, corresponding to `AF_INET`.
+    pub const IPV4: Domain = Domain(sys::AF_INET);
+
+    /// Domain for IPv6 communication, corresponding to `AF_INET6`.
+    pub const IPV6: Domain = Domain(sys::AF_INET6);
+
+    /// Domain for Unix socket communication, corresponding to `AF_UNIX`.
+    pub const UNIX: Domain = Domain(sys::AF_UNIX);
+
+    /// Returns the correct domain for `address`.
+    pub const fn for_address(address: SocketAddr) -> Domain {
+        match address {
+            SocketAddr::V4(_) => Domain::IPV4,
+            SocketAddr::V6(_) => Domain::IPV6,
+        }
+    }
+}
+
+impl From<c_int> for Domain {
+    fn from(d: c_int) -> Domain {
+        Domain(d)
+    }
+}
+
+impl From<Domain> for c_int {
+    fn from(d: Domain) -> c_int {
+        d.0
+    }
+}
+
+/// Specification of communication semantics on a socket.
+///
+/// This is a newtype wrapper around an integer which provides a nicer API in
+/// addition to an injection point for documentation. Convenience constants such
+/// as [`Type::STREAM`], [`Type::DGRAM`], etc, are provided to avoid reaching
+/// into libc for various constants.
+///
+/// This type is freely interconvertible with C's `int` type, however, if a raw
+/// value needs to be provided.
+#[derive(Copy, Clone, Eq, PartialEq)]
+pub struct Type(c_int);
+
+impl Type {
+    /// Type corresponding to `SOCK_STREAM`.
+    ///
+    /// Used for protocols such as TCP.
+    pub const STREAM: Type = Type(sys::SOCK_STREAM);
+
+    /// Type corresponding to `SOCK_DGRAM`.
+    ///
+    /// Used for protocols such as UDP.
+    pub const DGRAM: Type = Type(sys::SOCK_DGRAM);
+
+    /// Type corresponding to `SOCK_DCCP`.
+    ///
+    /// Used for the DCCP protocol.
+    #[cfg(all(feature = "all", target_os = "linux"))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "all", target_os = "linux"))))]
+    pub const DCCP: Type = Type(sys::SOCK_DCCP);
+
+    /// Type corresponding to `SOCK_SEQPACKET`.
+    #[cfg(all(feature = "all", not(target_os = "espidf")))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "all", not(target_os = "espidf")))))]
+    pub const SEQPACKET: Type = Type(sys::SOCK_SEQPACKET);
+
+    /// Type corresponding to `SOCK_RAW`.
+    #[cfg(all(feature = "all", not(any(target_os = "redox", target_os = "espidf"))))]
+    #[cfg_attr(
+        docsrs,
+        doc(cfg(all(feature = "all", not(any(target_os = "redox", target_os = "espidf")))))
+    )]
+    pub const RAW: Type = Type(sys::SOCK_RAW);
+}
+
+impl From<c_int> for Type {
+    fn from(t: c_int) -> Type {
+        Type(t)
+    }
+}
+
+impl From<Type> for c_int {
+    fn from(t: Type) -> c_int {
+        t.0
+    }
+}
+
+/// Protocol specification used for creating sockets via `Socket::new`.
+///
+/// This is a newtype wrapper around an integer which provides a nicer API in
+/// addition to an injection point for documentation.
+///
+/// This type is freely interconvertible with C's `int` type, however, if a raw
+/// value needs to be provided.
+#[derive(Copy, Clone, Eq, PartialEq)]
+pub struct Protocol(c_int);
+
+impl Protocol {
+    /// Protocol corresponding to `ICMPv4`.
+    pub const ICMPV4: Protocol = Protocol(sys::IPPROTO_ICMP);
+
+    /// Protocol corresponding to `ICMPv6`.
+    pub const ICMPV6: Protocol = Protocol(sys::IPPROTO_ICMPV6);
+
+    /// Protocol corresponding to `TCP`.
+    pub const TCP: Protocol = Protocol(sys::IPPROTO_TCP);
+
+    /// Protocol corresponding to `UDP`.
+    pub const UDP: Protocol = Protocol(sys::IPPROTO_UDP);
+
+    #[cfg(target_os = "linux")]
+    /// Protocol corresponding to `MPTCP`.
+    pub const MPTCP: Protocol = Protocol(sys::IPPROTO_MPTCP);
+
+    /// Protocol corresponding to `DCCP`.
+    #[cfg(all(feature = "all", target_os = "linux"))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "all", target_os = "linux"))))]
+    pub const DCCP: Protocol = Protocol(sys::IPPROTO_DCCP);
+
+    /// Protocol corresponding to `SCTP`.
+    #[cfg(all(feature = "all", any(target_os = "freebsd", target_os = "linux")))]
+    pub const SCTP: Protocol = Protocol(sys::IPPROTO_SCTP);
+
+    /// Protocol corresponding to `UDPLITE`.
+    #[cfg(all(
+        feature = "all",
+        any(
+            target_os = "android",
+            target_os = "freebsd",
+            target_os = "fuchsia",
+            target_os = "linux",
+        )
+    ))]
+    pub const UDPLITE: Protocol = Protocol(sys::IPPROTO_UDPLITE);
+
+    /// Protocol corresponding to `DIVERT`.
+    #[cfg(all(feature = "all", any(target_os = "freebsd", target_os = "openbsd")))]
+    pub const DIVERT: Protocol = Protocol(sys::IPPROTO_DIVERT);
+}
+
+impl From<c_int> for Protocol {
+    fn from(p: c_int) -> Protocol {
+        Protocol(p)
+    }
+}
+
+impl From<Protocol> for c_int {
+    fn from(p: Protocol) -> c_int {
+        p.0
+    }
+}
+
+/// Flags for incoming messages.
+///
+/// Flags provide additional information about incoming messages.
+#[cfg(not(target_os = "redox"))]
+#[cfg_attr(docsrs, doc(cfg(not(target_os = "redox"))))]
+#[derive(Copy, Clone, Eq, PartialEq)]
+pub struct RecvFlags(c_int);
+
+#[cfg(not(target_os = "redox"))]
+impl RecvFlags {
+    /// Check if the message contains a truncated datagram.
+    ///
+    /// This flag is only used for datagram-based sockets,
+    /// not for stream sockets.
+    ///
+    /// On Unix this corresponds to the `MSG_TRUNC` flag.
+    /// On Windows this corresponds to the `WSAEMSGSIZE` error code.
+    #[cfg(not(target_os = "espidf"))]
+    pub const fn is_truncated(self) -> bool {
+        self.0 & sys::MSG_TRUNC != 0
+    }
+}
+
+/// A version of [`IoSliceMut`] that allows the buffer to be uninitialised.
+///
+/// [`IoSliceMut`]: std::io::IoSliceMut
+#[repr(transparent)]
+pub struct MaybeUninitSlice<'a>(sys::MaybeUninitSlice<'a>);
+
+impl<'a> fmt::Debug for MaybeUninitSlice<'a> {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(self.0.as_slice(), fmt)
+    }
+}
+
+impl<'a> MaybeUninitSlice<'a> {
+    /// Creates a new `MaybeUninitSlice` wrapping a byte slice.
+    ///
+    /// # Panics
+    ///
+    /// Panics on Windows if the slice is larger than 4GB.
+    pub fn new(buf: &'a mut [MaybeUninit<u8>]) -> MaybeUninitSlice<'a> {
+        MaybeUninitSlice(sys::MaybeUninitSlice::new(buf))
+    }
+}
+
+impl<'a> Deref for MaybeUninitSlice<'a> {
+    type Target = [MaybeUninit<u8>];
+
+    fn deref(&self) -> &[MaybeUninit<u8>] {
+        self.0.as_slice()
+    }
+}
+
+impl<'a> DerefMut for MaybeUninitSlice<'a> {
+    fn deref_mut(&mut self) -> &mut [MaybeUninit<u8>] {
+        self.0.as_mut_slice()
+    }
+}
+
+/// Configures a socket's TCP keepalive parameters.
+///
+/// See [`Socket::set_tcp_keepalive`].
+#[derive(Debug, Clone)]
+pub struct TcpKeepalive {
+    #[cfg_attr(
+        any(target_os = "openbsd", target_os = "haiku", target_os = "vita"),
+        allow(dead_code)
+    )]
+    time: Option<Duration>,
+    #[cfg(not(any(
+        target_os = "openbsd",
+        target_os = "redox",
+        target_os = "solaris",
+        target_os = "nto",
+        target_os = "espidf",
+        target_os = "vita",
+        target_os = "haiku",
+    )))]
+    interval: Option<Duration>,
+    #[cfg(not(any(
+        target_os = "openbsd",
+        target_os = "redox",
+        target_os = "solaris",
+        target_os = "windows",
+        target_os = "nto",
+        target_os = "espidf",
+        target_os = "vita",
+        target_os = "haiku",
+    )))]
+    retries: Option<u32>,
+}
+
+impl TcpKeepalive {
+    /// Returns a new, empty set of TCP keepalive parameters.
+    #[allow(clippy::new_without_default)]
+    pub const fn new() -> TcpKeepalive {
+        TcpKeepalive {
+            time: None,
+            #[cfg(not(any(
+                target_os = "openbsd",
+                target_os = "redox",
+                target_os = "solaris",
+                target_os = "nto",
+                target_os = "espidf",
+                target_os = "vita",
+                target_os = "haiku",
+            )))]
+            interval: None,
+            #[cfg(not(any(
+                target_os = "openbsd",
+                target_os = "redox",
+                target_os = "solaris",
+                target_os = "windows",
+                target_os = "nto",
+                target_os = "espidf",
+                target_os = "vita",
+                target_os = "haiku",
+            )))]
+            retries: None,
+        }
+    }
+
+    /// Set the amount of time after which TCP keepalive probes will be sent on
+    /// idle connections.
+    ///
+    /// This will set `TCP_KEEPALIVE` on macOS and iOS, and
+    /// `TCP_KEEPIDLE` on all other Unix operating systems, except
+    /// OpenBSD and Haiku which don't support any way to set this
+    /// option. On Windows, this sets the value of the `tcp_keepalive`
+    /// struct's `keepalivetime` field.
+    ///
+    /// Some platforms specify this value in seconds, so sub-second
+    /// specifications may be omitted.
+    pub const fn with_time(self, time: Duration) -> Self {
+        Self {
+            time: Some(time),
+            ..self
+        }
+    }
+
+    /// Set the value of the `TCP_KEEPINTVL` option. On Windows, this sets the
+    /// value of the `tcp_keepalive` struct's `keepaliveinterval` field.
+    ///
+    /// Sets the time interval between TCP keepalive probes.
+    ///
+    /// Some platforms specify this value in seconds, so sub-second
+    /// specifications may be omitted.
+    #[cfg(any(
+        target_os = "android",
+        target_os = "dragonfly",
+        target_os = "freebsd",
+        target_os = "fuchsia",
+        target_os = "illumos",
+        target_os = "ios",
+        target_os = "visionos",
+        target_os = "linux",
+        target_os = "macos",
+        target_os = "netbsd",
+        target_os = "tvos",
+        target_os = "watchos",
+        target_os = "windows",
+        target_os = "cygwin",
+    ))]
+    #[cfg_attr(
+        docsrs,
+        doc(cfg(any(
+            target_os = "android",
+            target_os = "dragonfly",
+            target_os = "freebsd",
+            target_os = "fuchsia",
+            target_os = "illumos",
+            target_os = "ios",
+            target_os = "visionos",
+            target_os = "linux",
+            target_os = "macos",
+            target_os = "netbsd",
+            target_os = "tvos",
+            target_os = "watchos",
+            target_os = "windows",
+        )))
+    )]
+    pub const fn with_interval(self, interval: Duration) -> Self {
+        Self {
+            interval: Some(interval),
+            ..self
+        }
+    }
+
+    /// Set the value of the `TCP_KEEPCNT` option.
+    ///
+    /// Set the maximum number of TCP keepalive probes that will be sent before
+    /// dropping a connection, if TCP keepalive is enabled on this socket.
+    #[cfg(all(
+        feature = "all",
+        any(
+            target_os = "android",
+            target_os = "dragonfly",
+            target_os = "freebsd",
+            target_os = "fuchsia",
+            target_os = "illumos",
+            target_os = "ios",
+            target_os = "visionos",
+            target_os = "linux",
+            target_os = "macos",
+            target_os = "netbsd",
+            target_os = "tvos",
+            target_os = "watchos",
+            target_os = "cygwin",
+        )
+    ))]
+    #[cfg_attr(
+        docsrs,
+        doc(cfg(all(
+            feature = "all",
+            any(
+                target_os = "android",
+                target_os = "dragonfly",
+                target_os = "freebsd",
+                target_os = "fuchsia",
+                target_os = "illumos",
+                target_os = "ios",
+                target_os = "visionos",
+                target_os = "linux",
+                target_os = "macos",
+                target_os = "netbsd",
+                target_os = "tvos",
+                target_os = "watchos",
+            )
+        )))
+    )]
+    pub const fn with_retries(self, retries: u32) -> Self {
+        Self {
+            retries: Some(retries),
+            ..self
+        }
+    }
+}
+
+/// Configuration of a `sendmsg(2)` system call.
+///
+/// This wraps `msghdr` on Unix and `WSAMSG` on Windows. Also see [`MsgHdrMut`]
+/// for the variant used by `recvmsg(2)`.
+#[cfg(not(target_os = "redox"))]
+pub struct MsgHdr<'addr, 'bufs, 'control> {
+    inner: sys::msghdr,
+    #[allow(clippy::type_complexity)]
+    _lifetimes: PhantomData<(&'addr SockAddr, &'bufs IoSlice<'bufs>, &'control [u8])>,
+}
+
+#[cfg(not(target_os = "redox"))]
+impl<'addr, 'bufs, 'control> MsgHdr<'addr, 'bufs, 'control> {
+    /// Create a new `MsgHdr` with all empty/zero fields.
+    #[allow(clippy::new_without_default)]
+    pub fn new() -> MsgHdr<'addr, 'bufs, 'control> {
+        // SAFETY: all zero is valid for `msghdr` and `WSAMSG`.
+        MsgHdr {
+            inner: unsafe { mem::zeroed() },
+            _lifetimes: PhantomData,
+        }
+    }
+
+    /// Set the address (name) of the message.
+    ///
+    /// Corresponds to setting `msg_name` and `msg_namelen` on Unix and `name`
+    /// and `namelen` on Windows.
+    pub fn with_addr(mut self, addr: &'addr SockAddr) -> Self {
+        sys::set_msghdr_name(&mut self.inner, addr);
+        self
+    }
+
+    /// Set the buffer(s) of the message.
+    ///
+    /// Corresponds to setting `msg_iov` and `msg_iovlen` on Unix and `lpBuffers`
+    /// and `dwBufferCount` on Windows.
+    pub fn with_buffers(mut self, bufs: &'bufs [IoSlice<'_>]) -> Self {
+        let ptr = bufs.as_ptr() as *mut _;
+        sys::set_msghdr_iov(&mut self.inner, ptr, bufs.len());
+        self
+    }
+
+    /// Set the control buffer of the message.
+    ///
+    /// Corresponds to setting `msg_control` and `msg_controllen` on Unix and
+    /// `Control` on Windows.
+    pub fn with_control(mut self, buf: &'control [u8]) -> Self {
+        let ptr = buf.as_ptr() as *mut _;
+        sys::set_msghdr_control(&mut self.inner, ptr, buf.len());
+        self
+    }
+
+    /// Set the flags of the message.
+    ///
+    /// Corresponds to setting `msg_flags` on Unix and `dwFlags` on Windows.
+    pub fn with_flags(mut self, flags: sys::c_int) -> Self {
+        sys::set_msghdr_flags(&mut self.inner, flags);
+        self
+    }
+}
+
+#[cfg(not(target_os = "redox"))]
+impl<'name, 'bufs, 'control> fmt::Debug for MsgHdr<'name, 'bufs, 'control> {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        "MsgHdr".fmt(fmt)
+    }
+}
+
+/// Configuration of a `recvmsg(2)` system call.
+///
+/// This wraps `msghdr` on Unix and `WSAMSG` on Windows. Also see [`MsgHdr`] for
+/// the variant used by `sendmsg(2)`.
+#[cfg(not(target_os = "redox"))]
+pub struct MsgHdrMut<'addr, 'bufs, 'control> {
+    inner: sys::msghdr,
+    #[allow(clippy::type_complexity)]
+    _lifetimes: PhantomData<(
+        &'addr mut SockAddr,
+        &'bufs mut MaybeUninitSlice<'bufs>,
+        &'control mut [u8],
+    )>,
+}
+
+#[cfg(not(target_os = "redox"))]
+impl<'addr, 'bufs, 'control> MsgHdrMut<'addr, 'bufs, 'control> {
+    /// Create a new `MsgHdrMut` with all empty/zero fields.
+    #[allow(clippy::new_without_default)]
+    pub fn new() -> MsgHdrMut<'addr, 'bufs, 'control> {
+        // SAFETY: all zero is valid for `msghdr` and `WSAMSG`.
+        MsgHdrMut {
+            inner: unsafe { mem::zeroed() },
+            _lifetimes: PhantomData,
+        }
+    }
+
+    /// Set the mutable address (name) of the message.
+    ///
+    /// Corresponds to setting `msg_name` and `msg_namelen` on Unix and `name`
+    /// and `namelen` on Windows.
+    #[allow(clippy::needless_pass_by_ref_mut)]
+    pub fn with_addr(mut self, addr: &'addr mut SockAddr) -> Self {
+        sys::set_msghdr_name(&mut self.inner, addr);
+        self
+    }
+
+    /// Set the mutable buffer(s) of the message.
+    ///
+    /// Corresponds to setting `msg_iov` and `msg_iovlen` on Unix and `lpBuffers`
+    /// and `dwBufferCount` on Windows.
+    pub fn with_buffers(mut self, bufs: &'bufs mut [MaybeUninitSlice<'_>]) -> Self {
+        sys::set_msghdr_iov(&mut self.inner, bufs.as_mut_ptr().cast(), bufs.len());
+        self
+    }
+
+    /// Set the mutable control buffer of the message.
+    ///
+    /// Corresponds to setting `msg_control` and `msg_controllen` on Unix and
+    /// `Control` on Windows.
+    pub fn with_control(mut self, buf: &'control mut [MaybeUninit<u8>]) -> Self {
+        sys::set_msghdr_control(&mut self.inner, buf.as_mut_ptr().cast(), buf.len());
+        self
+    }
+
+    /// Returns the flags of the message.
+    pub fn flags(&self) -> RecvFlags {
+        sys::msghdr_flags(&self.inner)
+    }
+
+    /// Gets the length of the control buffer.
+    ///
+    /// Can be used to determine how much, if any, of the control buffer was filled by `recvmsg`.
+    ///
+    /// Corresponds to `msg_controllen` on Unix and `Control.len` on Windows.
+    pub fn control_len(&self) -> usize {
+        sys::msghdr_control_len(&self.inner)
+    }
+}
+
+#[cfg(not(target_os = "redox"))]
+impl<'name, 'bufs, 'control> fmt::Debug for MsgHdrMut<'name, 'bufs, 'control> {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        "MsgHdrMut".fmt(fmt)
+    }
+}