Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

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

18 files changed, 3054 insertions, 0 deletions

diff --git a/third_party/rust/net2/.cargo-checksum.json b/third_party/rust/net2/.cargo-checksum.json
new file mode 100644
index 0000000000..0605e787bc
--- /dev/null
+++ b/third_party/rust/net2/.cargo-checksum.json
@@ -0,0 +1 @@
+{"files":{"Cargo.toml":"fd3b1aa06b845c62754d8eaf1ca8a4cc07126b2fb76ed822a470a8881240f3db","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"6485b8ed310d3f0340bf1ad1f47645069ce4069dcc6bb46c7d5c6faf41de1fdb","README.md":"a99cb0401bd49e68c945f6a249175dd5c4a5117b2c8cc5d5fb7dea369002574e","src/ext.rs":"08e78272ef677efcb4c029489214055ddb392f3163a931f260fccbd8a824eb51","src/lib.rs":"2f20b711078a365240f2c7683d9c34cac7c09bfd4756d89bf099bff56fb0de72","src/socket.rs":"f544539c94ccf8fc8710edbbf170d706a6037319e562b7d253aff2e1a75b7c48","src/sys/unix/impls.rs":"05f123226e8fe7559317d50864021650b2455d25d01a9aff1c65c01ae26cf4ef","src/sys/unix/mod.rs":"e06b26bad48c815b9a2af4509d1873333e2aad0031980f6d2625f72542698d56","src/sys/wasi/impls.rs":"da4e95a27a765b64fbbebce55b860020ac891456085ed706d5f8f391e0d1cddf","src/sys/wasi/mod.rs":"e88b02f4d5e0ae558f093d49cc0bb1b3cdf86ede625d00ed9231f0ab414e483f","src/sys/windows/impls.rs":"bee70b7cd45055c4eaa1967f7aad7ec46639de458c71ed6f3e97a2f7b2c49281","src/sys/windows/mod.rs":"31a73007ea65a4905e93395f86105d2ef9fb84d3d795511c6cfdc8cba595cb0c","src/tcp.rs":"0bebf5cca75714151de30c8f2d7697ca519c57da065e93ba81796bce04673f8d","src/udp.rs":"8af5a55a4ae5e4120ffe18dcc4dc24072e18da34bf3591a02b18653e5d3e8ac8","src/unix.rs":"1156707694cb1f002a2eb2144bf205a73412e1661fd196a8a2a7bc8ea5aaad2d","src/utils.rs":"d31de5333a6fa2f5c99b64cc937be596888d9863264632e6bc6b36b30197fa5b"},"package":"74d0df99cfcd2530b2e694f6e17e7f37b8e26bb23983ac530c0c97408837c631"}
\ No newline at end of file
diff --git a/third_party/rust/net2/Cargo.toml b/third_party/rust/net2/Cargo.toml
new file mode 100644
index 0000000000..702ee35475
--- /dev/null
+++ b/third_party/rust/net2/Cargo.toml
@@ -0,0 +1,51 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+name = "net2"
+version = "0.2.38"
+authors = ["Alex Crichton <alex@alexcrichton.com>"]
+include = [
+    "Cargo.toml",
+    "LICENSE-APACHE",
+    "LICENSE-MIT",
+    "README.md",
+    "src/**/*.rs",
+]
+description = """
+Extensions to the standard library's networking types as proposed in RFC 1158.
+"""
+homepage = "https://github.com/deprecrated/net2-rs"
+documentation = "https://docs.rs/net2/~0.2"
+readme = "README.md"
+license = "MIT/Apache-2.0"
+repository = "https://github.com/deprecrated/net2-rs"
+
+[dependencies.cfg-if]
+version = "0.1"
+
+[features]
+default = ["duration"]
+duration = []
+nightly = []
+
+[target."cfg(any(unix, target_os=\"wasi\"))".dependencies.libc]
+version = "0.2.54"
+
+[target."cfg(windows)".dependencies.winapi]
+version = "0.3"
+features = [
+    "handleapi",
+    "winsock2",
+    "ws2def",
+    "ws2ipdef",
+    "ws2tcpip",
+]
diff --git a/third_party/rust/net2/LICENSE-APACHE b/third_party/rust/net2/LICENSE-APACHE
new file mode 100644
index 0000000000..16fe87b06e
--- /dev/null
+++ b/third_party/rust/net2/LICENSE-APACHE
@@ -0,0 +1,201 @@
+                              Apache License
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+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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diff --git a/third_party/rust/net2/LICENSE-MIT b/third_party/rust/net2/LICENSE-MIT
new file mode 100644
index 0000000000..39d4bdb5ac
--- /dev/null
+++ b/third_party/rust/net2/LICENSE-MIT
@@ -0,0 +1,25 @@
+Copyright (c) 2014 The Rust Project Developers
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/third_party/rust/net2/README.md b/third_party/rust/net2/README.md
new file mode 100644
index 0000000000..9818422220
--- /dev/null
+++ b/third_party/rust/net2/README.md
@@ -0,0 +1,31 @@
+# net2
+
+Extensions to the standard library's networking types, proposed in [RFC 1158][rfc].
+
+[rfc]: https://github.com/alexcrichton/rfcs/blob/net2.1/text/0000-io-net-2.1.md
+
+[![Build Status](https://github.com/deprecrated/net2-rs/workflows/CI/badge.svg)](https://github.com/deprecrated/net2-rs/actions?query=workflow%3ACI+branch%3Amaster)
+[![Documentation](https://docs.rs/net2/badge.svg?version=0.2)](https://docs.rs/net2/~0.2)
+
+# net2 is Deprecated
+
+Prospective and existing consumers are encouraged to consider
+[socket2](https://crates.io/crates/socket2) instead.
+
+
+# License
+
+This project is licensed under either of
+
+ * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
+   http://www.apache.org/licenses/LICENSE-2.0)
+ * MIT license ([LICENSE-MIT](LICENSE-MIT) or
+   http://opensource.org/licenses/MIT)
+
+at your option.
+
+### Contribution
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in Serde by you, as defined in the Apache-2.0 license, shall be
+dual licensed as above, without any additional terms or conditions.
diff --git a/third_party/rust/net2/src/ext.rs b/third_party/rust/net2/src/ext.rs
new file mode 100644
index 0000000000..76e58d9b79
--- /dev/null
+++ b/third_party/rust/net2/src/ext.rs
@@ -0,0 +1,1466 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(bad_style, dead_code)]
+
+use std::io;
+use std::mem;
+use std::net::{TcpStream, TcpListener, UdpSocket, Ipv4Addr, Ipv6Addr};
+use std::net::ToSocketAddrs;
+
+use {TcpBuilder, UdpBuilder, FromInner};
+use sys;
+use sys::c;
+use socket;
+
+cfg_if! {
+    if #[cfg(any(target_os = "dragonfly",
+                 target_os = "freebsd",
+                 target_os = "haiku",
+                 target_os = "ios",
+                 target_os = "macos",
+                 target_os = "netbsd",
+                 target_os = "openbsd",
+                 target_os = "solaris",
+                 target_os = "illumos",
+                 target_env = "uclibc"))] {
+        use libc::IPV6_JOIN_GROUP as IPV6_ADD_MEMBERSHIP;
+        use libc::IPV6_LEAVE_GROUP as IPV6_DROP_MEMBERSHIP;
+    } else {
+        // ...
+    }
+}
+
+use std::time::Duration;
+
+#[cfg(any(unix, target_os = "wasi"))] use libc::*;
+#[cfg(any(unix))] use std::os::unix::prelude::*;
+#[cfg(target_os = "wasi")] use std::os::wasi::prelude::*;
+#[cfg(unix)] pub type Socket = c_int;
+#[cfg(target_os = "wasi")] pub type Socket = std::os::wasi::io::RawFd;
+#[cfg(windows)] pub type Socket = SOCKET;
+#[cfg(windows)] use std::os::windows::prelude::*;
+#[cfg(any(windows, target_os = "wasi"))] use sys::c::*;
+
+#[cfg(windows)] const SIO_KEEPALIVE_VALS: DWORD = 0x98000004;
+#[cfg(windows)]
+#[repr(C)]
+struct tcp_keepalive {
+    onoff: c_ulong,
+    keepalivetime: c_ulong,
+    keepaliveinterval: c_ulong,
+}
+
+#[cfg(any(unix, target_os = "wasi"))] fn v(opt: c_int) -> c_int { opt }
+#[cfg(windows)] fn v(opt: IPPROTO) -> c_int { opt as c_int }
+
+#[cfg(target_os = "wasi")]
+pub fn set_opt<T: Copy>(_sock: Socket, _opt: c_int, _val: c_int,
+                       _payload: T) -> io::Result<()> {
+    Ok(())
+}
+
+#[cfg(not(target_os = "wasi"))]
+pub fn set_opt<T: Copy>(sock: Socket, opt: c_int, val: c_int,
+                       payload: T) -> io::Result<()> {
+    unsafe {
+        let payload = &payload as *const T as *const c_void;
+        try!(::cvt(setsockopt(sock, opt, val, payload as *const _,
+                              mem::size_of::<T>() as socklen_t)));
+    }
+    Ok(())
+}
+
+#[cfg(target_os = "wasi")]
+pub fn get_opt<T: Copy>(_sock: Socket, _opt: c_int, _val: c_int) -> io::Result<T> {
+    unimplemented!()
+}
+#[cfg(not(target_os = "wasi"))]
+pub fn get_opt<T: Copy>(sock: Socket, opt: c_int, val: c_int) -> io::Result<T> {
+    unsafe {
+        let mut slot: T = mem::zeroed();
+        let mut len = mem::size_of::<T>() as socklen_t;
+        try!(::cvt(getsockopt(sock, opt, val,
+                              &mut slot as *mut _ as *mut _,
+                              &mut len)));
+        assert_eq!(len as usize, mem::size_of::<T>());
+        Ok(slot)
+    }
+}
+
+/// Extension methods for the standard [`TcpStream` type][link] in `std::net`.
+///
+/// [link]: https://doc.rust-lang.org/std/net/struct.TcpStream.html
+pub trait TcpStreamExt {
+    /// Sets the value of the `TCP_NODELAY` option on this socket.
+    ///
+    /// If set, this option disables the Nagle algorithm. This means that
+    /// segments are always sent as soon as possible, even if there is only a
+    /// small amount of data. When not set, data is buffered until there is a
+    /// sufficient amount to send out, thereby avoiding the frequent sending of
+    /// small packets.
+    fn set_nodelay(&self, nodelay: bool) -> io::Result<()>;
+
+    /// Gets the value of the `TCP_NODELAY` option on this socket.
+    ///
+    /// For more information about this option, see [`set_nodelay`][link].
+    ///
+    /// [link]: #tymethod.set_nodelay
+    fn nodelay(&self) -> io::Result<bool>;
+
+    /// Sets the value of the `SO_RCVBUF` option on this socket.
+    ///
+    /// Changes the size of the operating system's receive buffer associated with the socket.
+    fn set_recv_buffer_size(&self, size: usize) -> io::Result<()>;
+
+    /// Gets the value of the `SO_RCVBUF` option on this socket.
+    ///
+    /// For more information about this option, see [`set_recv_buffer_size`][link].
+    ///
+    /// [link]: #tymethod.set_recv_buffer_size
+    fn recv_buffer_size(&self) -> io::Result<usize>;
+
+    /// Sets the value of the `SO_SNDBUF` option on this socket.
+    ///
+    /// Changes the size of the operating system's send buffer associated with the socket.
+    fn set_send_buffer_size(&self, size: usize) -> io::Result<()>;
+
+    /// Gets the value of the `SO_SNDBUF` option on this socket.
+    ///
+    /// For more information about this option, see [`set_send_buffer`][link].
+    ///
+    /// [link]: #tymethod.set_send_buffer
+    fn send_buffer_size(&self) -> io::Result<usize>;
+
+    /// Sets whether keepalive messages are enabled to be sent on this socket.
+    ///
+    /// On Unix, this option will set the `SO_KEEPALIVE` as well as the
+    /// `TCP_KEEPALIVE` or `TCP_KEEPIDLE` option (depending on your platform).
+    /// On Windows, this will set the `SIO_KEEPALIVE_VALS` option.
+    ///
+    /// If `None` is specified then keepalive messages are disabled, otherwise
+    /// the number of milliseconds specified will be the time to remain idle
+    /// before sending a TCP keepalive probe.
+    ///
+    /// Some platforms specify this value in seconds, so sub-second millisecond
+    /// specifications may be omitted.
+    fn set_keepalive_ms(&self, keepalive: Option<u32>) -> io::Result<()>;
+
+    /// Returns whether keepalive messages are enabled on this socket, and if so
+    /// the amount of milliseconds between them.
+    ///
+    /// For more information about this option, see [`set_keepalive_ms`][link].
+    ///
+    /// [link]: #tymethod.set_keepalive_ms
+    fn keepalive_ms(&self) -> io::Result<Option<u32>>;
+
+    /// Sets whether keepalive messages are enabled to be sent on this socket.
+    ///
+    /// On Unix, this option will set the `SO_KEEPALIVE` as well as the
+    /// `TCP_KEEPALIVE` or `TCP_KEEPIDLE` option (depending on your platform).
+    /// On Windows, this will set the `SIO_KEEPALIVE_VALS` option.
+    ///
+    /// If `None` is specified then keepalive messages are disabled, otherwise
+    /// the duration specified will be the time to remain idle before sending a
+    /// TCP keepalive probe.
+    ///
+    /// Some platforms specify this value in seconds, so sub-second
+    /// specifications may be omitted.
+    fn set_keepalive(&self, keepalive: Option<Duration>) -> io::Result<()>;
+
+    /// Returns whether keepalive messages are enabled on this socket, and if so
+    /// the duration of time between them.
+    ///
+    /// For more information about this option, see [`set_keepalive`][link].
+    ///
+    /// [link]: #tymethod.set_keepalive
+    fn keepalive(&self) -> io::Result<Option<Duration>>;
+
+    /// Sets the `SO_RCVTIMEO` option for this socket.
+    ///
+    /// This option specifies the timeout, in milliseconds, of how long calls to
+    /// this socket's `read` function will wait before returning a timeout. A
+    /// value of `None` means that no read timeout should be specified and
+    /// otherwise `Some` indicates the number of milliseconds for the timeout.
+    fn set_read_timeout_ms(&self, val: Option<u32>) -> io::Result<()>;
+
+    /// Sets the `SO_RCVTIMEO` option for this socket.
+    ///
+    /// This option specifies the timeout of how long calls to this socket's
+    /// `read` function will wait before returning a timeout. A value of `None`
+    /// means that no read timeout should be specified and otherwise `Some`
+    /// indicates the number of duration of the timeout.
+    fn set_read_timeout(&self, val: Option<Duration>) -> io::Result<()>;
+
+    /// Gets the value of the `SO_RCVTIMEO` option for this socket.
+    ///
+    /// For more information about this option, see [`set_read_timeout_ms`][link].
+    ///
+    /// [link]: #tymethod.set_read_timeout_ms
+    fn read_timeout_ms(&self) -> io::Result<Option<u32>>;
+
+    /// Gets the value of the `SO_RCVTIMEO` option for this socket.
+    ///
+    /// For more information about this option, see [`set_read_timeout`][link].
+    ///
+    /// [link]: #tymethod.set_read_timeout
+    fn read_timeout(&self) -> io::Result<Option<Duration>>;
+
+    /// Sets the `SO_SNDTIMEO` option for this socket.
+    ///
+    /// This option specifies the timeout, in milliseconds, of how long calls to
+    /// this socket's `write` function will wait before returning a timeout. A
+    /// value of `None` means that no read timeout should be specified and
+    /// otherwise `Some` indicates the number of milliseconds for the timeout.
+    fn set_write_timeout_ms(&self, val: Option<u32>) -> io::Result<()>;
+
+    /// Sets the `SO_SNDTIMEO` option for this socket.
+    ///
+    /// This option specifies the timeout of how long calls to this socket's
+    /// `write` function will wait before returning a timeout. A value of `None`
+    /// means that no read timeout should be specified and otherwise `Some`
+    /// indicates the duration of the timeout.
+    fn set_write_timeout(&self, val: Option<Duration>) -> io::Result<()>;
+
+    /// Gets the value of the `SO_SNDTIMEO` option for this socket.
+    ///
+    /// For more information about this option, see [`set_write_timeout_ms`][link].
+    ///
+    /// [link]: #tymethod.set_write_timeout_ms
+    fn write_timeout_ms(&self) -> io::Result<Option<u32>>;
+
+    /// Gets the value of the `SO_SNDTIMEO` option for this socket.
+    ///
+    /// For more information about this option, see [`set_write_timeout`][link].
+    ///
+    /// [link]: #tymethod.set_write_timeout
+    fn write_timeout(&self) -> io::Result<Option<Duration>>;
+
+    /// Sets the value for the `IP_TTL` option on this socket.
+    ///
+    /// This value sets the time-to-live field that is used in every packet sent
+    /// from this socket.
+    fn set_ttl(&self, ttl: u32) -> io::Result<()>;
+
+    /// Gets the value of the `IP_TTL` option for this socket.
+    ///
+    /// For more information about this option, see [`set_ttl`][link].
+    ///
+    /// [link]: #tymethod.set_ttl
+    fn ttl(&self) -> io::Result<u32>;
+
+    /// Sets the value for the `IPV6_V6ONLY` option on this socket.
+    ///
+    /// If this is set to `true` then the socket is restricted to sending and
+    /// receiving IPv6 packets only. In this case two IPv4 and IPv6 applications
+    /// can bind the same port at the same time.
+    ///
+    /// If this is set to `false` then the socket can be used to send and
+    /// receive packets from an IPv4-mapped IPv6 address.
+    fn set_only_v6(&self, only_v6: bool) -> io::Result<()>;
+
+    /// Gets the value of the `IPV6_V6ONLY` option for this socket.
+    ///
+    /// For more information about this option, see [`set_only_v6`][link].
+    ///
+    /// [link]: #tymethod.set_only_v6
+    fn only_v6(&self) -> io::Result<bool>;
+
+    /// Executes a `connect` operation on this socket, establishing a connection
+    /// to the host specified by `addr`.
+    ///
+    /// Note that this normally does not need to be called on a `TcpStream`,
+    /// it's typically automatically done as part of a normal
+    /// `TcpStream::connect` function call or `TcpBuilder::connect` method call.
+    ///
+    /// This should only be necessary if an unconnected socket was extracted
+    /// from a `TcpBuilder` and then needs to be connected.
+    fn connect<T: ToSocketAddrs>(&self, addr: T) -> io::Result<()>;
+
+    /// Get the value of the `SO_ERROR` option on this socket.
+    ///
+    /// This will retrieve the stored error in the underlying socket, clearing
+    /// the field in the process. This can be useful for checking errors between
+    /// calls.
+    fn take_error(&self) -> io::Result<Option<io::Error>>;
+
+    /// Moves this TCP stream into or out of nonblocking mode.
+    ///
+    /// On Unix this corresponds to calling fcntl, and on Windows this
+    /// corresponds to calling ioctlsocket.
+    fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()>;
+
+    /// Sets the linger duration of this socket by setting the SO_LINGER option
+    fn set_linger(&self, dur: Option<Duration>) -> io::Result<()>;
+
+    /// reads the linger duration for this socket by getting the SO_LINGER option
+    fn linger(&self) -> io::Result<Option<Duration>>;
+}
+
+/// Extension methods for the standard [`TcpListener` type][link] in `std::net`.
+///
+/// [link]: https://doc.rust-lang.org/std/net/struct.TcpListener.html
+pub trait TcpListenerExt {
+    /// Sets the value for the `IP_TTL` option on this socket.
+    ///
+    /// This is the same as [`TcpStreamExt::set_ttl`][other].
+    ///
+    /// [other]: trait.TcpStreamExt.html#tymethod.set_ttl
+    fn set_ttl(&self, ttl: u32) -> io::Result<()>;
+
+    /// Gets the value of the `IP_TTL` option for this socket.
+    ///
+    /// For more information about this option, see
+    /// [`TcpStreamExt::set_ttl`][link].
+    ///
+    /// [link]: trait.TcpStreamExt.html#tymethod.set_ttl
+    fn ttl(&self) -> io::Result<u32>;
+
+    /// Sets the value for the `IPV6_V6ONLY` option on this socket.
+    ///
+    /// For more information about this option, see
+    /// [`TcpStreamExt::set_only_v6`][link].
+    ///
+    /// [link]: trait.TcpStreamExt.html#tymethod.set_only_v6
+    fn set_only_v6(&self, only_v6: bool) -> io::Result<()>;
+
+    /// Gets the value of the `IPV6_V6ONLY` option for this socket.
+    ///
+    /// For more information about this option, see
+    /// [`TcpStreamExt::set_only_v6`][link].
+    ///
+    /// [link]: trait.TcpStreamExt.html#tymethod.set_only_v6
+    fn only_v6(&self) -> io::Result<bool>;
+
+    /// Get the value of the `SO_ERROR` option on this socket.
+    ///
+    /// This will retrieve the stored error in the underlying socket, clearing
+    /// the field in the process. This can be useful for checking errors between
+    /// calls.
+    fn take_error(&self) -> io::Result<Option<io::Error>>;
+
+    /// Moves this TCP listener into or out of nonblocking mode.
+    ///
+    /// For more information about this option, see
+    /// [`TcpStreamExt::set_nonblocking`][link].
+    ///
+    /// [link]: trait.TcpStreamExt.html#tymethod.set_nonblocking
+    fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()>;
+
+    /// Sets the linger duration of this socket by setting the SO_LINGER option
+    fn set_linger(&self, dur: Option<Duration>) -> io::Result<()>;
+
+    /// reads the linger duration for this socket by getting the SO_LINGER option
+    fn linger(&self) -> io::Result<Option<Duration>>;
+}
+
+/// Extension methods for the standard [`UdpSocket` type][link] in `std::net`.
+///
+/// [link]: https://doc.rust-lang.org/std/net/struct.UdpSocket.html
+pub trait UdpSocketExt {
+    /// Sets the value of the `SO_RCVBUF` option on this socket.
+    ///
+    /// Changes the size of the operating system's receive buffer associated with the socket.
+    fn set_recv_buffer_size(&self, size: usize) -> io::Result<()>;
+
+    /// Gets the value of the `SO_RCVBUF` option on this socket.
+    ///
+    /// For more information about this option, see [`set_recv_buffer_size`][link].
+    ///
+    /// [link]: #tymethod.set_recv_buffer_size
+    fn recv_buffer_size(&self) -> io::Result<usize>;
+
+    /// Sets the value of the `SO_SNDBUF` option on this socket.
+    ///
+    /// Changes the size of the operating system's send buffer associated with the socket.
+    fn set_send_buffer_size(&self, size: usize) -> io::Result<()>;
+
+    /// Gets the value of the `SO_SNDBUF` option on this socket.
+    ///
+    /// For more information about this option, see [`set_send_buffer`][link].
+    ///
+    /// [link]: #tymethod.set_send_buffer
+    fn send_buffer_size(&self) -> io::Result<usize>;
+
+    /// Sets the value of the `SO_BROADCAST` option for this socket.
+    ///
+    /// When enabled, this socket is allowed to send packets to a broadcast
+    /// address.
+    fn set_broadcast(&self, broadcast: bool) -> io::Result<()>;
+
+    /// Gets the value of the `SO_BROADCAST` option for this socket.
+    ///
+    /// For more information about this option, see
+    /// [`set_broadcast`][link].
+    ///
+    /// [link]: #tymethod.set_broadcast
+    fn broadcast(&self) -> io::Result<bool>;
+
+    /// Sets the value of the `IP_MULTICAST_LOOP` option for this socket.
+    ///
+    /// If enabled, multicast packets will be looped back to the local socket.
+    /// Note that this may not have any affect on IPv6 sockets.
+    fn set_multicast_loop_v4(&self, multicast_loop_v4: bool) -> io::Result<()>;
+
+    /// Gets the value of the `IP_MULTICAST_LOOP` option for this socket.
+    ///
+    /// For more information about this option, see
+    /// [`set_multicast_loop_v4`][link].
+    ///
+    /// [link]: #tymethod.set_multicast_loop_v4
+    fn multicast_loop_v4(&self) -> io::Result<bool>;
+
+    /// Sets the value of the `IP_MULTICAST_TTL` option for this socket.
+    ///
+    /// Indicates the time-to-live value of outgoing multicast packets for
+    /// this socket. The default value is 1 which means that multicast packets
+    /// don't leave the local network unless explicitly requested.
+    ///
+    /// Note that this may not have any affect on IPv6 sockets.
+    fn set_multicast_ttl_v4(&self, multicast_ttl_v4: u32) -> io::Result<()>;
+
+    /// Gets the value of the `IP_MULTICAST_TTL` option for this socket.
+    ///
+    /// For more information about this option, see
+    /// [`set_multicast_ttl_v4`][link].
+    ///
+    /// [link]: #tymethod.set_multicast_ttl_v4
+    fn multicast_ttl_v4(&self) -> io::Result<u32>;
+
+    /// Sets the value of the `IPV6_MULTICAST_HOPS` option for this socket
+    fn set_multicast_hops_v6(&self, hops: u32) -> io::Result<()>;
+
+    /// Gets the value of the `IPV6_MULTICAST_HOPS` option for this socket
+    fn multicast_hops_v6(&self) -> io::Result<u32>;
+
+    /// Sets the value of the `IPV6_MULTICAST_LOOP` option for this socket.
+    ///
+    /// Controls whether this socket sees the multicast packets it sends itself.
+    /// Note that this may not have any affect on IPv4 sockets.
+    fn set_multicast_loop_v6(&self, multicast_loop_v6: bool) -> io::Result<()>;
+
+    /// Gets the value of the `IPV6_MULTICAST_LOOP` option for this socket.
+    ///
+    /// For more information about this option, see
+    /// [`set_multicast_loop_v6`][link].
+    ///
+    /// [link]: #tymethod.set_multicast_loop_v6
+    fn multicast_loop_v6(&self) -> io::Result<bool>;
+
+    /// Sets the value of the `IP_MULTICAST_IF` option for this socket.
+    ///
+    /// Specifies the interface to use for routing multicast packets.
+    fn set_multicast_if_v4(&self, interface: &Ipv4Addr) -> io::Result<()>;
+
+    /// Gets the value of the `IP_MULTICAST_IF` option for this socket.
+    ///
+    /// Returns the interface to use for routing multicast packets.
+    fn multicast_if_v4(&self) -> io::Result<Ipv4Addr>;
+
+
+    /// Sets the value of the `IPV6_MULTICAST_IF` option for this socket.
+    ///
+    /// Specifies the interface to use for routing multicast packets.
+    fn set_multicast_if_v6(&self, interface: u32) -> io::Result<()>;
+
+    /// Gets the value of the `IPV6_MULTICAST_IF` option for this socket.
+    ///
+    /// Returns the interface to use for routing multicast packets.
+    fn multicast_if_v6(&self) -> io::Result<u32>;
+
+    /// Sets the value for the `IP_TTL` option on this socket.
+    ///
+    /// This is the same as [`TcpStreamExt::set_ttl`][other].
+    ///
+    /// [other]: trait.TcpStreamExt.html#tymethod.set_ttl
+    fn set_ttl(&self, ttl: u32) -> io::Result<()>;
+
+    /// Gets the value of the `IP_TTL` option for this socket.
+    ///
+    /// For more information about this option, see
+    /// [`TcpStreamExt::set_ttl`][link].
+    ///
+    /// [link]: trait.TcpStreamExt.html#tymethod.set_ttl
+    fn ttl(&self) -> io::Result<u32>;
+
+    /// Sets the value for the `IPV6_UNICAST_HOPS` option on this socket.
+    ///
+    /// Specifies the hop limit for ipv6 unicast packets
+    fn set_unicast_hops_v6(&self, ttl: u32) -> io::Result<()>;
+
+    /// Gets the value of the `IPV6_UNICAST_HOPS` option for this socket.
+    ///
+    /// Specifies the hop limit for ipv6 unicast packets
+    fn unicast_hops_v6(&self) -> io::Result<u32>;
+
+    /// Sets the value for the `IPV6_V6ONLY` option on this socket.
+    ///
+    /// For more information about this option, see
+    /// [`TcpStreamExt::set_only_v6`][link].
+    ///
+    /// [link]: trait.TcpStreamExt.html#tymethod.set_only_v6
+    fn set_only_v6(&self, only_v6: bool) -> io::Result<()>;
+
+    /// Gets the value of the `IPV6_V6ONLY` option for this socket.
+    ///
+    /// For more information about this option, see
+    /// [`TcpStreamExt::set_only_v6`][link].
+    ///
+    /// [link]: trait.TcpStreamExt.html#tymethod.set_only_v6
+    fn only_v6(&self) -> io::Result<bool>;
+
+    /// Executes an operation of the `IP_ADD_MEMBERSHIP` type.
+    ///
+    /// This function specifies a new multicast group for this socket to join.
+    /// The address must be a valid multicast address, and `interface` is the
+    /// address of the local interface with which the system should join the
+    /// multicast group. If it's equal to `INADDR_ANY` then an appropriate
+    /// interface is chosen by the system.
+    fn join_multicast_v4(&self, multiaddr: &Ipv4Addr, interface: &Ipv4Addr)
+                         -> io::Result<()>;
+
+    /// Executes an operation of the `IPV6_ADD_MEMBERSHIP` type.
+    ///
+    /// This function specifies a new multicast group for this socket to join.
+    /// The address must be a valid multicast address, and `interface` is the
+    /// index of the interface to join/leave (or 0 to indicate any interface).
+    fn join_multicast_v6(&self, multiaddr: &Ipv6Addr, interface: u32)
+                         -> io::Result<()>;
+
+    /// Executes an operation of the `IP_DROP_MEMBERSHIP` type.
+    ///
+    /// For more information about this option, see
+    /// [`join_multicast_v4`][link].
+    ///
+    /// [link]: #tymethod.join_multicast_v4
+    fn leave_multicast_v4(&self, multiaddr: &Ipv4Addr, interface: &Ipv4Addr)
+                          -> io::Result<()>;
+
+    /// Executes an operation of the `IPV6_DROP_MEMBERSHIP` type.
+    ///
+    /// For more information about this option, see
+    /// [`join_multicast_v6`][link].
+    ///
+    /// [link]: #tymethod.join_multicast_v6
+    fn leave_multicast_v6(&self, multiaddr: &Ipv6Addr, interface: u32)
+                          -> io::Result<()>;
+
+    /// Sets the `SO_RCVTIMEO` option for this socket.
+    ///
+    /// This option specifies the timeout, in milliseconds, of how long calls to
+    /// this socket's `read` function will wait before returning a timeout. A
+    /// value of `None` means that no read timeout should be specified and
+    /// otherwise `Some` indicates the number of milliseconds for the timeout.
+    fn set_read_timeout_ms(&self, val: Option<u32>) -> io::Result<()>;
+
+    /// Sets the `SO_RCVTIMEO` option for this socket.
+    ///
+    /// This option specifies the timeout of how long calls to this socket's
+    /// `read` function will wait before returning a timeout. A value of `None`
+    /// means that no read timeout should be specified and otherwise `Some`
+    /// indicates the number of duration of the timeout.
+    fn set_read_timeout(&self, val: Option<Duration>) -> io::Result<()>;
+
+    /// Gets the value of the `SO_RCVTIMEO` option for this socket.
+    ///
+    /// For more information about this option, see [`set_read_timeout_ms`][link].
+    ///
+    /// [link]: #tymethod.set_read_timeout_ms
+    fn read_timeout_ms(&self) -> io::Result<Option<u32>>;
+
+    /// Gets the value of the `SO_RCVTIMEO` option for this socket.
+    ///
+    /// For more information about this option, see [`set_read_timeout`][link].
+    ///
+    /// [link]: #tymethod.set_read_timeout
+    fn read_timeout(&self) -> io::Result<Option<Duration>>;
+
+    /// Sets the `SO_SNDTIMEO` option for this socket.
+    ///
+    /// This option specifies the timeout, in milliseconds, of how long calls to
+    /// this socket's `write` function will wait before returning a timeout. A
+    /// value of `None` means that no read timeout should be specified and
+    /// otherwise `Some` indicates the number of milliseconds for the timeout.
+    fn set_write_timeout_ms(&self, val: Option<u32>) -> io::Result<()>;
+
+    /// Sets the `SO_SNDTIMEO` option for this socket.
+    ///
+    /// This option specifies the timeout of how long calls to this socket's
+    /// `write` function will wait before returning a timeout. A value of `None`
+    /// means that no read timeout should be specified and otherwise `Some`
+    /// indicates the duration of the timeout.
+    fn set_write_timeout(&self, val: Option<Duration>) -> io::Result<()>;
+
+    /// Gets the value of the `SO_SNDTIMEO` option for this socket.
+    ///
+    /// For more information about this option, see [`set_write_timeout_ms`][link].
+    ///
+    /// [link]: #tymethod.set_write_timeout_ms
+    fn write_timeout_ms(&self) -> io::Result<Option<u32>>;
+
+    /// Gets the value of the `SO_SNDTIMEO` option for this socket.
+    ///
+    /// For more information about this option, see [`set_write_timeout`][link].
+    ///
+    /// [link]: #tymethod.set_write_timeout
+    fn write_timeout(&self) -> io::Result<Option<Duration>>;
+
+    /// Get the value of the `SO_ERROR` option on this socket.
+    ///
+    /// This will retrieve the stored error in the underlying socket, clearing
+    /// the field in the process. This can be useful for checking errors between
+    /// calls.
+    fn take_error(&self) -> io::Result<Option<io::Error>>;
+
+    /// Connects this UDP socket to a remote address, allowing the `send` and
+    /// `recv` syscalls to be used to send data and also applies filters to only
+    /// receive data from the specified address.
+    fn connect<A: ToSocketAddrs>(&self, addr: A) -> io::Result<()>;
+
+    /// Sends data on the socket to the remote address to which it is connected.
+    ///
+    /// The `connect` method will connect this socket to a remote address. This
+    /// method will fail if the socket is not connected.
+    fn send(&self, buf: &[u8]) -> io::Result<usize>;
+
+    /// Receives data on the socket from the remote address to which it is
+    /// connected.
+    ///
+    /// The `connect` method will connect this socket to a remote address. This
+    /// method will fail if the socket is not connected.
+    fn recv(&self, buf: &mut [u8]) -> io::Result<usize>;
+
+    /// Moves this UDP socket into or out of nonblocking mode.
+    ///
+    /// For more information about this option, see
+    /// [`TcpStreamExt::set_nonblocking`][link].
+    ///
+    /// [link]: trait.TcpStreamExt.html#tymethod.set_nonblocking
+    fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()>;
+}
+
+#[doc(hidden)]
+pub trait AsSock {
+    fn as_sock(&self) -> Socket;
+}
+
+#[cfg(any(unix, target_os = "wasi"))]
+impl<T: AsRawFd> AsSock for T {
+    fn as_sock(&self) -> Socket { self.as_raw_fd() }
+}
+#[cfg(windows)]
+impl<T: AsRawSocket> AsSock for T {
+    fn as_sock(&self) -> Socket { self.as_raw_socket() as Socket }
+}
+
+cfg_if! {
+    if #[cfg(any(target_os = "macos", target_os = "ios"))] {
+        use libc::TCP_KEEPALIVE as KEEPALIVE_OPTION;
+    } else if #[cfg(any(target_os = "haiku", target_os = "netbsd", target_os = "openbsd"))] {
+        use libc::SO_KEEPALIVE as KEEPALIVE_OPTION;
+    } else if #[cfg(unix)] {
+        use libc::TCP_KEEPIDLE as KEEPALIVE_OPTION;
+    } else {
+        // ...
+    }
+}
+
+impl TcpStreamExt for TcpStream {
+
+    fn set_recv_buffer_size(&self, size: usize) -> io::Result<()> {
+        // TODO: casting usize to a c_int should be a checked cast
+        set_opt(self.as_sock(), SOL_SOCKET, SO_RCVBUF, size as c_int)
+    }
+
+    fn recv_buffer_size(&self) -> io::Result<usize> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_RCVBUF).map(int2usize)
+    }
+
+    fn set_send_buffer_size(&self, size: usize) -> io::Result<()> {
+        set_opt(self.as_sock(), SOL_SOCKET, SO_SNDBUF, size as c_int)
+    }
+
+    fn send_buffer_size(&self) -> io::Result<usize> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_SNDBUF).map(int2usize)
+    }
+
+    fn set_nodelay(&self, nodelay: bool) -> io::Result<()> {
+        set_opt(self.as_sock(), v(IPPROTO_TCP), TCP_NODELAY,
+               nodelay as c_int)
+    }
+    fn nodelay(&self) -> io::Result<bool> {
+        get_opt(self.as_sock(), v(IPPROTO_TCP), TCP_NODELAY)
+            .map(int2bool)
+    }
+
+    fn set_keepalive(&self, keepalive: Option<Duration>) -> io::Result<()> {
+        self.set_keepalive_ms(keepalive.map(dur2ms))
+    }
+
+    fn keepalive(&self) -> io::Result<Option<Duration>> {
+        self.keepalive_ms().map(|o| o.map(ms2dur))
+    }
+
+    #[cfg(unix)]
+    fn set_keepalive_ms(&self, keepalive: Option<u32>) -> io::Result<()> {
+        try!(set_opt(self.as_sock(), SOL_SOCKET, SO_KEEPALIVE,
+                    keepalive.is_some() as c_int));
+        if let Some(dur) = keepalive {
+            try!(set_opt(self.as_sock(), v(IPPROTO_TCP), KEEPALIVE_OPTION,
+                        (dur / 1000) as c_int));
+        }
+        Ok(())
+    }
+
+    #[cfg(unix)]
+    fn keepalive_ms(&self) -> io::Result<Option<u32>> {
+        let keepalive = try!(get_opt::<c_int>(self.as_sock(), SOL_SOCKET,
+                                             SO_KEEPALIVE));
+        if keepalive == 0 {
+            return Ok(None)
+        }
+        let secs = try!(get_opt::<c_int>(self.as_sock(), v(IPPROTO_TCP),
+                                        KEEPALIVE_OPTION));
+        Ok(Some((secs as u32) * 1000))
+    }
+
+     #[cfg(target_os = "wasi")]
+    fn set_keepalive_ms(&self, _keepalive: Option<u32>) -> io::Result<()> {
+        unimplemented!()
+    }
+
+    #[cfg(target_os = "wasi")]
+    fn keepalive_ms(&self) -> io::Result<Option<u32>> {
+        unimplemented!()
+    }
+
+    #[cfg(windows)]
+    fn set_keepalive_ms(&self, keepalive: Option<u32>) -> io::Result<()> {
+        let ms = keepalive.unwrap_or(INFINITE);
+        let ka = tcp_keepalive {
+            onoff: keepalive.is_some() as c_ulong,
+            keepalivetime: ms as c_ulong,
+            keepaliveinterval: ms as c_ulong,
+        };
+        unsafe {
+            ::cvt_win(WSAIoctl(self.as_sock(),
+                               SIO_KEEPALIVE_VALS,
+                               &ka as *const _ as *mut _,
+                               mem::size_of_val(&ka) as DWORD,
+                               0 as *mut _,
+                               0,
+                               0 as *mut _,
+                               0 as *mut _,
+                               None)).map(|_| ())
+        }
+    }
+
+    #[cfg(windows)]
+    fn keepalive_ms(&self) -> io::Result<Option<u32>> {
+        let mut ka = tcp_keepalive {
+            onoff: 0,
+            keepalivetime: 0,
+            keepaliveinterval: 0,
+        };
+        unsafe {
+            try!(::cvt_win(WSAIoctl(self.as_sock(),
+                                    SIO_KEEPALIVE_VALS,
+                                    0 as *mut _,
+                                    0,
+                                    &mut ka as *mut _ as *mut _,
+                                    mem::size_of_val(&ka) as DWORD,
+                                    0 as *mut _,
+                                    0 as *mut _,
+                                    None)));
+        }
+        Ok({
+            if ka.onoff == 0 {
+                None
+            } else {
+                timeout2ms(ka.keepaliveinterval as DWORD)
+            }
+        })
+    }
+
+    fn set_read_timeout_ms(&self, dur: Option<u32>) -> io::Result<()> {
+        set_opt(self.as_sock(), SOL_SOCKET, SO_RCVTIMEO,
+               ms2timeout(dur))
+    }
+
+    fn read_timeout_ms(&self) -> io::Result<Option<u32>> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_RCVTIMEO)
+            .map(timeout2ms)
+    }
+
+    fn set_write_timeout_ms(&self, dur: Option<u32>) -> io::Result<()> {
+        set_opt(self.as_sock(), SOL_SOCKET, SO_SNDTIMEO,
+               ms2timeout(dur))
+    }
+
+    fn write_timeout_ms(&self) -> io::Result<Option<u32>> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_SNDTIMEO)
+            .map(timeout2ms)
+    }
+
+    fn set_read_timeout(&self, dur: Option<Duration>) -> io::Result<()> {
+        self.set_read_timeout_ms(dur.map(dur2ms))
+    }
+
+    fn read_timeout(&self) -> io::Result<Option<Duration>> {
+        self.read_timeout_ms().map(|o| o.map(ms2dur))
+    }
+
+    fn set_write_timeout(&self, dur: Option<Duration>) -> io::Result<()> {
+        self.set_write_timeout_ms(dur.map(dur2ms))
+    }
+
+    fn write_timeout(&self) -> io::Result<Option<Duration>> {
+        self.write_timeout_ms().map(|o| o.map(ms2dur))
+    }
+
+    fn set_ttl(&self, ttl: u32) -> io::Result<()> {
+        set_opt(self.as_sock(), IPPROTO_IP, IP_TTL, ttl as c_int)
+    }
+
+    fn ttl(&self) -> io::Result<u32> {
+        get_opt::<c_int>(self.as_sock(), IPPROTO_IP, IP_TTL)
+            .map(|b| b as u32)
+    }
+
+    fn set_only_v6(&self, only_v6: bool) -> io::Result<()> {
+        set_opt(self.as_sock(), v(IPPROTO_IPV6), IPV6_V6ONLY, only_v6 as c_int)
+    }
+
+    fn only_v6(&self) -> io::Result<bool> {
+        get_opt(self.as_sock(), v(IPPROTO_IPV6), IPV6_V6ONLY).map(int2bool)
+    }
+
+    fn connect<T: ToSocketAddrs>(&self, addr: T) -> io::Result<()> {
+        do_connect(self.as_sock(), addr)
+    }
+
+    fn take_error(&self) -> io::Result<Option<io::Error>> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_ERROR).map(int2err)
+    }
+
+    fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
+        set_nonblocking(self.as_sock(), nonblocking)
+    }
+
+    fn set_linger(&self, dur: Option<Duration>) -> io::Result<()> {
+        set_opt(self.as_sock(), SOL_SOCKET, SO_LINGER, dur2linger(dur))
+    }
+
+    fn linger(&self) -> io::Result<Option<Duration>> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_LINGER).map(linger2dur)
+    }
+}
+
+#[cfg(any(unix, target_os = "wasi"))]
+fn ms2timeout(dur: Option<u32>) -> timeval {
+    // TODO: be more rigorous
+    match dur {
+        Some(d) => timeval {
+            tv_sec: (d / 1000) as time_t,
+            tv_usec: (d % 1000) as suseconds_t,
+        },
+        None => timeval { tv_sec: 0, tv_usec: 0 },
+    }
+}
+
+#[cfg(any(unix, target_os = "wasi"))]
+fn timeout2ms(dur: timeval) -> Option<u32> {
+    if dur.tv_sec == 0 && dur.tv_usec == 0 {
+        None
+    } else {
+        Some(dur.tv_sec as u32 * 1000 + dur.tv_usec as u32 / 1000)
+    }
+}
+
+#[cfg(windows)]
+fn ms2timeout(dur: Option<u32>) -> DWORD {
+    dur.unwrap_or(0)
+}
+
+#[cfg(windows)]
+fn timeout2ms(dur: DWORD) -> Option<u32> {
+    if dur == 0 {
+        None
+    } else {
+        Some(dur)
+    }
+}
+
+fn linger2dur(linger_opt: linger) -> Option<Duration> {
+    if linger_opt.l_onoff == 0 {
+        None
+    }
+    else {
+        Some(Duration::from_secs(linger_opt.l_linger as u64))
+    }
+}
+
+#[cfg(windows)]
+fn dur2linger(dur: Option<Duration>) -> linger {
+    match dur {
+        Some(d) => {
+            linger {
+                l_onoff: 1,
+                l_linger: d.as_secs() as u16,
+            }
+        },
+        None => linger { l_onoff: 0, l_linger: 0 },
+    }
+}
+
+#[cfg(any(unix, target_os = "wasi"))]
+fn dur2linger(dur: Option<Duration>) -> linger {
+    match dur {
+        Some(d) => {
+            linger {
+                l_onoff: 1,
+                l_linger: d.as_secs() as c_int,
+            }
+        },
+        None => linger { l_onoff: 0, l_linger: 0 },
+    }
+}
+
+fn ms2dur(ms: u32) -> Duration {
+    Duration::new((ms as u64) / 1000, (ms as u32) % 1000 * 1_000_000)
+}
+
+fn dur2ms(dur: Duration) -> u32 {
+    (dur.as_secs() as u32 * 1000) + (dur.subsec_nanos() / 1_000_000)
+}
+
+pub fn int2bool(n: c_int) -> bool {
+    if n == 0 {false} else {true}
+}
+
+pub fn int2usize(n: c_int) -> usize {
+    // TODO: casting c_int to a usize should be a checked cast
+    n as usize
+}
+
+pub fn int2err(n: c_int) -> Option<io::Error> {
+    if n == 0 {
+        None
+    } else {
+        Some(io::Error::from_raw_os_error(n as i32))
+    }
+}
+
+impl UdpSocketExt for UdpSocket {
+
+    fn set_recv_buffer_size(&self, size: usize) -> io::Result<()> {
+        set_opt(self.as_sock(), SOL_SOCKET, SO_RCVBUF, size as c_int)
+    }
+
+    fn recv_buffer_size(&self) -> io::Result<usize> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_RCVBUF).map(int2usize)
+    }
+
+    fn set_send_buffer_size(&self, size: usize) -> io::Result<()> {
+        set_opt(self.as_sock(), SOL_SOCKET, SO_SNDBUF, size as c_int)
+    }
+
+    fn send_buffer_size(&self) -> io::Result<usize> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_SNDBUF).map(int2usize)
+    }
+
+    fn set_broadcast(&self, broadcast: bool) -> io::Result<()> {
+        set_opt(self.as_sock(), SOL_SOCKET, SO_BROADCAST,
+               broadcast as c_int)
+    }
+    fn broadcast(&self) -> io::Result<bool> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_BROADCAST)
+            .map(int2bool)
+    }
+    fn set_multicast_loop_v4(&self, multicast_loop_v4: bool) -> io::Result<()> {
+        set_opt(self.as_sock(), IPPROTO_IP, IP_MULTICAST_LOOP,
+               multicast_loop_v4 as c_int)
+    }
+    fn multicast_loop_v4(&self) -> io::Result<bool> {
+        get_opt(self.as_sock(), IPPROTO_IP, IP_MULTICAST_LOOP)
+            .map(int2bool)
+    }
+
+    fn set_multicast_ttl_v4(&self, multicast_ttl_v4: u32) -> io::Result<()> {
+        set_opt(self.as_sock(), IPPROTO_IP, IP_MULTICAST_TTL,
+               multicast_ttl_v4 as c_int)
+    }
+
+    fn multicast_ttl_v4(&self) -> io::Result<u32> {
+        get_opt::<c_int>(self.as_sock(), IPPROTO_IP, IP_MULTICAST_TTL)
+            .map(|b| b as u32)
+    }
+
+    fn set_multicast_hops_v6(&self, _hops: u32) -> io::Result<()> {
+        set_opt(self.as_sock(), v(IPPROTO_IPV6), IPV6_MULTICAST_HOPS,
+               _hops as c_int)
+    }
+
+    fn multicast_hops_v6(&self) -> io::Result<u32> {
+        get_opt::<c_int>(self.as_sock(), v(IPPROTO_IPV6), IPV6_MULTICAST_HOPS)
+            .map(|b| b as u32)
+    }
+
+    fn set_multicast_loop_v6(&self, multicast_loop_v6: bool) -> io::Result<()> {
+        set_opt(self.as_sock(), v(IPPROTO_IPV6), IPV6_MULTICAST_LOOP,
+               multicast_loop_v6 as c_int)
+    }
+    fn multicast_loop_v6(&self) -> io::Result<bool> {
+        get_opt(self.as_sock(), v(IPPROTO_IPV6), IPV6_MULTICAST_LOOP)
+            .map(int2bool)
+    }
+
+    fn set_multicast_if_v4(&self, _interface: &Ipv4Addr) -> io::Result<()> {
+        set_opt(self.as_sock(), IPPROTO_IP, IP_MULTICAST_IF, ip2in_addr(_interface))
+    }
+
+    fn multicast_if_v4(&self) -> io::Result<Ipv4Addr> {
+        get_opt(self.as_sock(), IPPROTO_IP, IP_MULTICAST_IF).map(in_addr2ip)
+    }
+
+    fn set_multicast_if_v6(&self, _interface: u32) -> io::Result<()> {
+        set_opt(self.as_sock(), v(IPPROTO_IPV6), IPV6_MULTICAST_IF, to_ipv6mr_interface(_interface))
+    }
+
+    fn multicast_if_v6(&self) -> io::Result<u32> {
+        get_opt::<c_int>(self.as_sock(), v(IPPROTO_IPV6), IPV6_MULTICAST_IF).map(|b| b as u32)
+    }
+
+    fn set_ttl(&self, ttl: u32) -> io::Result<()> {
+        set_opt(self.as_sock(), IPPROTO_IP, IP_TTL, ttl as c_int)
+    }
+
+    fn ttl(&self) -> io::Result<u32> {
+        get_opt::<c_int>(self.as_sock(), IPPROTO_IP, IP_TTL)
+            .map(|b| b as u32)
+    }
+
+    fn set_unicast_hops_v6(&self, _ttl: u32) -> io::Result<()> {
+        set_opt(self.as_sock(), v(IPPROTO_IPV6), IPV6_UNICAST_HOPS, _ttl as c_int)
+    }
+
+    fn unicast_hops_v6(&self) -> io::Result<u32> {
+        get_opt::<c_int>(self.as_sock(), IPPROTO_IP, IPV6_UNICAST_HOPS)
+            .map(|b| b as u32)
+    }
+
+    fn set_only_v6(&self, only_v6: bool) -> io::Result<()> {
+        set_opt(self.as_sock(), v(IPPROTO_IPV6), IPV6_V6ONLY, only_v6 as c_int)
+    }
+
+    fn only_v6(&self) -> io::Result<bool> {
+        get_opt(self.as_sock(), v(IPPROTO_IPV6), IPV6_V6ONLY).map(int2bool)
+    }
+
+    fn join_multicast_v4(&self, multiaddr: &Ipv4Addr, interface: &Ipv4Addr)
+                         -> io::Result<()> {
+        let mreq = ip_mreq {
+            imr_multiaddr: ip2in_addr(multiaddr),
+            imr_interface: ip2in_addr(interface),
+        };
+        set_opt(self.as_sock(), IPPROTO_IP, IP_ADD_MEMBERSHIP, mreq)
+    }
+
+    fn join_multicast_v6(&self, multiaddr: &Ipv6Addr, interface: u32)
+                         -> io::Result<()> {
+        let mreq = ipv6_mreq {
+            ipv6mr_multiaddr: ip2in6_addr(multiaddr),
+            ipv6mr_interface: to_ipv6mr_interface(interface),
+        };
+        set_opt(self.as_sock(), v(IPPROTO_IPV6), IPV6_ADD_MEMBERSHIP,
+               mreq)
+    }
+
+    fn leave_multicast_v4(&self, multiaddr: &Ipv4Addr, interface: &Ipv4Addr)
+                          -> io::Result<()> {
+        let mreq = ip_mreq {
+            imr_multiaddr: ip2in_addr(multiaddr),
+            imr_interface: ip2in_addr(interface),
+        };
+        set_opt(self.as_sock(), IPPROTO_IP, IP_DROP_MEMBERSHIP, mreq)
+    }
+
+    fn leave_multicast_v6(&self, multiaddr: &Ipv6Addr, interface: u32)
+                          -> io::Result<()> {
+        let mreq = ipv6_mreq {
+            ipv6mr_multiaddr: ip2in6_addr(multiaddr),
+            ipv6mr_interface: to_ipv6mr_interface(interface),
+        };
+        set_opt(self.as_sock(), v(IPPROTO_IPV6), IPV6_DROP_MEMBERSHIP,
+               mreq)
+    }
+
+    fn set_read_timeout_ms(&self, dur: Option<u32>) -> io::Result<()> {
+        set_opt(self.as_sock(), SOL_SOCKET, SO_RCVTIMEO,
+               ms2timeout(dur))
+    }
+
+    fn read_timeout_ms(&self) -> io::Result<Option<u32>> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_RCVTIMEO)
+            .map(timeout2ms)
+    }
+
+    fn set_write_timeout_ms(&self, dur: Option<u32>) -> io::Result<()> {
+        set_opt(self.as_sock(), SOL_SOCKET, SO_SNDTIMEO,
+               ms2timeout(dur))
+    }
+
+    fn write_timeout_ms(&self) -> io::Result<Option<u32>> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_SNDTIMEO)
+            .map(timeout2ms)
+    }
+
+    fn set_read_timeout(&self, dur: Option<Duration>) -> io::Result<()> {
+        self.set_read_timeout_ms(dur.map(dur2ms))
+    }
+
+    fn read_timeout(&self) -> io::Result<Option<Duration>> {
+        self.read_timeout_ms().map(|o| o.map(ms2dur))
+    }
+
+    fn set_write_timeout(&self, dur: Option<Duration>) -> io::Result<()> {
+        self.set_write_timeout_ms(dur.map(dur2ms))
+    }
+
+    fn write_timeout(&self) -> io::Result<Option<Duration>> {
+        self.write_timeout_ms().map(|o| o.map(ms2dur))
+    }
+
+    fn take_error(&self) -> io::Result<Option<io::Error>> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_ERROR).map(int2err)
+    }
+
+    fn connect<A: ToSocketAddrs>(&self, addr: A) -> io::Result<()> {
+        do_connect(self.as_sock(), addr)
+    }
+
+    #[cfg(unix)]
+    fn send(&self, buf: &[u8]) -> io::Result<usize> {
+        unsafe {
+            ::cvt(send(self.as_sock() as c_int, buf.as_ptr() as *const _, buf.len(), 0)).map(|n| n as usize)
+        }
+    }
+
+     #[cfg(target_os = "wasi")]
+    fn send(&self, buf: &[u8]) -> io::Result<usize> {
+        let _so_datalen: *mut sys::c::size_t = &mut 0;
+        unsafe {
+            let _errno = libc::__wasi_sock_send(
+                self.as_sock() as libc::__wasi_fd_t,
+                buf.as_ptr() as *const _,
+                buf.len(),
+                0,
+                _so_datalen,
+            );
+            // TODO: handle errno
+            Ok((*_so_datalen) as usize)
+        }
+    }
+
+    #[cfg(windows)]
+    fn send(&self, buf: &[u8]) -> io::Result<usize> {
+        let len = ::std::cmp::min(buf.len(), c_int::max_value() as usize);
+        let buf = &buf[..len];
+        unsafe {
+            ::cvt(send(self.as_sock(), buf.as_ptr() as *const _, len as c_int, 0))
+                .map(|n| n as usize)
+        }
+    }
+
+    #[cfg(unix)]
+    fn recv(&self, buf: &mut [u8]) -> io::Result<usize> {
+        unsafe {
+            ::cvt(recv(self.as_sock(), buf.as_mut_ptr() as *mut _, buf.len(), 0))
+                .map(|n| n as usize)
+        }
+    }
+
+    #[cfg(target_os = "wasi")]
+    fn recv(&self, buf: &mut [u8]) -> io::Result<usize> {
+        let _ro_datalen: *mut sys::c::size_t = &mut 0;
+        let _ro_flags: *mut sys::c::__wasi_roflags_t = &mut 0;
+        unsafe {
+            let _errno = __wasi_sock_recv(
+                self.as_sock(),
+                buf.as_mut_ptr() as *mut _,
+                buf.len(),
+                0,
+                _ro_datalen,
+                _ro_flags,
+            );
+            // TODO: handle errno
+            Ok((*_ro_datalen) as usize)
+        }
+    }
+
+    #[cfg(windows)]
+    fn recv(&self, buf: &mut [u8]) -> io::Result<usize> {
+        let len = ::std::cmp::min(buf.len(), c_int::max_value() as usize);
+        let buf = &mut buf[..len];
+        unsafe {
+            ::cvt(recv(self.as_sock(), buf.as_mut_ptr() as *mut _, buf.len() as c_int, 0))
+                .map(|n| n as usize)
+        }
+    }
+
+    fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
+        set_nonblocking(self.as_sock(), nonblocking)
+    }
+}
+
+fn do_connect<A: ToSocketAddrs>(sock: Socket, addr: A) -> io::Result<()> {
+    let err = io::Error::new(io::ErrorKind::Other,
+                             "no socket addresses resolved");
+    let addrs = try!(addr.to_socket_addrs());
+    let sys = sys::Socket::from_inner(sock);
+    let sock = socket::Socket::from_inner(sys);
+    let ret = addrs.fold(Err(err), |prev, addr| {
+        prev.or_else(|_| sock.connect(&addr))
+    });
+    mem::forget(sock);
+    return ret
+}
+
+#[cfg(unix)]
+fn set_nonblocking(sock: Socket, nonblocking: bool) -> io::Result<()> {
+    let mut nonblocking = nonblocking as c_ulong;
+    ::cvt(unsafe {
+        ioctl(sock, FIONBIO, &mut nonblocking)
+    }).map(|_| ())
+}
+
+#[cfg(target_os = "wasi")]
+fn set_nonblocking(_sock: Socket, _nonblocking: bool) -> io::Result<()> {
+    Ok(())
+}
+
+#[cfg(windows)]
+fn set_nonblocking(sock: Socket, nonblocking: bool) -> io::Result<()> {
+    let mut nonblocking = nonblocking as c_ulong;
+    ::cvt(unsafe {
+        ioctlsocket(sock, FIONBIO as c_int, &mut nonblocking)
+    }).map(|_| ())
+}
+
+#[cfg(any(unix, target_os = "wasi"))]
+fn ip2in_addr(ip: &Ipv4Addr) -> in_addr {
+    let oct = ip.octets();
+    in_addr {
+        s_addr: ::hton(((oct[0] as u32) << 24) |
+                       ((oct[1] as u32) << 16) |
+                       ((oct[2] as u32) <<  8) |
+                       ((oct[3] as u32) <<  0)),
+    }
+}
+
+#[cfg(windows)]
+fn ip2in_addr(ip: &Ipv4Addr) -> in_addr {
+    let oct = ip.octets();
+    unsafe {
+        let mut S_un: in_addr_S_un = mem::zeroed();
+        *S_un.S_addr_mut() = ::hton(((oct[0] as u32) << 24) |
+                                ((oct[1] as u32) << 16) |
+                                ((oct[2] as u32) <<  8) |
+                                ((oct[3] as u32) <<  0));
+        in_addr {
+            S_un: S_un,
+        }
+    }
+}
+
+fn in_addr2ip(ip: &in_addr) -> Ipv4Addr {
+    let h_addr = c::in_addr_to_u32(ip);
+
+    let a: u8 = (h_addr >> 24) as u8;
+    let b: u8 = (h_addr >> 16) as u8;
+    let c: u8 = (h_addr >> 8) as u8;
+    let d: u8 = (h_addr >> 0) as u8;
+
+    Ipv4Addr::new(a,b,c,d)
+}
+
+#[cfg(target_os = "android")]
+fn to_ipv6mr_interface(value: u32) -> c_int {
+    value as c_int
+}
+
+#[cfg(not(target_os = "android"))]
+fn to_ipv6mr_interface(value: u32) -> c_uint {
+    value as c_uint
+}
+
+fn ip2in6_addr(ip: &Ipv6Addr) -> in6_addr {
+    let mut ret: in6_addr = unsafe { mem::zeroed() };
+    let seg = ip.segments();
+    let bytes = [
+        (seg[0] >> 8) as u8,
+        (seg[0] >> 0) as u8,
+        (seg[1] >> 8) as u8,
+        (seg[1] >> 0) as u8,
+        (seg[2] >> 8) as u8,
+        (seg[2] >> 0) as u8,
+        (seg[3] >> 8) as u8,
+        (seg[3] >> 0) as u8,
+        (seg[4] >> 8) as u8,
+        (seg[4] >> 0) as u8,
+        (seg[5] >> 8) as u8,
+        (seg[5] >> 0) as u8,
+        (seg[6] >> 8) as u8,
+        (seg[6] >> 0) as u8,
+        (seg[7] >> 8) as u8,
+        (seg[7] >> 0) as u8,
+    ];
+    #[cfg(windows)] unsafe { *ret.u.Byte_mut() = bytes; }
+    #[cfg(not(windows))]   { ret.s6_addr = bytes; }
+
+    return ret
+}
+
+impl TcpListenerExt for TcpListener {
+    fn set_ttl(&self, ttl: u32) -> io::Result<()> {
+        set_opt(self.as_sock(), IPPROTO_IP, IP_TTL, ttl as c_int)
+    }
+
+    fn ttl(&self) -> io::Result<u32> {
+        get_opt::<c_int>(self.as_sock(), IPPROTO_IP, IP_TTL)
+            .map(|b| b as u32)
+    }
+
+    fn set_only_v6(&self, only_v6: bool) -> io::Result<()> {
+        set_opt(self.as_sock(), v(IPPROTO_IPV6), IPV6_V6ONLY, only_v6 as c_int)
+    }
+
+    fn only_v6(&self) -> io::Result<bool> {
+        get_opt(self.as_sock(), v(IPPROTO_IPV6), IPV6_V6ONLY).map(int2bool)
+    }
+
+    fn take_error(&self) -> io::Result<Option<io::Error>> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_ERROR).map(int2err)
+    }
+
+    fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
+        set_nonblocking(self.as_sock(), nonblocking)
+    }
+
+    fn set_linger(&self, dur: Option<Duration>) -> io::Result<()> {
+        set_opt(self.as_sock(), SOL_SOCKET, SO_LINGER, dur2linger(dur))
+    }
+
+    fn linger(&self) -> io::Result<Option<Duration>> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_LINGER).map(linger2dur)
+    }
+}
+
+impl TcpBuilder {
+    /// Sets the value for the `IP_TTL` option on this socket.
+    ///
+    /// This is the same as [`TcpStreamExt::set_ttl`][other].
+    ///
+    /// [other]: trait.TcpStreamExt.html#tymethod.set_ttl
+    pub fn ttl(&self, ttl: u32) -> io::Result<&Self> {
+        set_opt(self.as_sock(), IPPROTO_IP, IP_TTL, ttl as c_int)
+            .map(|()| self)
+    }
+
+    /// Sets the value for the `IPV6_V6ONLY` option on this socket.
+    ///
+    /// This is the same as [`TcpStreamExt::set_only_v6`][other].
+    ///
+    /// [other]: trait.TcpStreamExt.html#tymethod.set_only_v6
+    pub fn only_v6(&self, only_v6: bool) -> io::Result<&Self> {
+        set_opt(self.as_sock(), v(IPPROTO_IPV6), IPV6_V6ONLY, only_v6 as c_int)
+            .map(|()| self)
+    }
+
+    /// Set value for the `SO_REUSEADDR` option on this socket.
+    ///
+    /// This indicates that further calls to `bind` may allow reuse of local
+    /// addresses. For IPv4 sockets this means that a socket may bind even when
+    /// there's a socket already listening on this port.
+    pub fn reuse_address(&self, reuse: bool) -> io::Result<&Self> {
+        set_opt(self.as_sock(), SOL_SOCKET, SO_REUSEADDR,
+               reuse as c_int).map(|()| self)
+    }
+
+    /// Check the `SO_REUSEADDR` option on this socket.
+    pub fn get_reuse_address(&self) -> io::Result<bool> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_REUSEADDR).map(int2bool)
+    }
+
+    /// Get the value of the `SO_ERROR` option on this socket.
+    ///
+    /// This will retrieve the stored error in the underlying socket, clearing
+    /// the field in the process. This can be useful for checking errors between
+    /// calls.
+    pub fn take_error(&self) -> io::Result<Option<io::Error>> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_ERROR).map(int2err)
+    }
+
+    /// Sets the linger option for this socket
+    fn set_linger(&self, dur: Option<Duration>) -> io::Result<()> {
+        set_opt(self.as_sock(), SOL_SOCKET, SO_LINGER, dur2linger(dur))
+    }
+
+    /// Gets the linger option for this socket
+    fn linger(&self) -> io::Result<Option<Duration>> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_LINGER).map(linger2dur)
+    }
+}
+
+impl UdpBuilder {
+    /// Sets the value for the `IP_TTL` option on this socket.
+    ///
+    /// This is the same as [`TcpStreamExt::set_ttl`][other].
+    ///
+    /// [other]: trait.TcpStreamExt.html#tymethod.set_ttl
+    pub fn ttl(&self, ttl: u32) -> io::Result<&Self> {
+        set_opt(self.as_sock(), IPPROTO_IP, IP_TTL, ttl as c_int)
+            .map(|()| self)
+    }
+
+    /// Sets the value for the `IPV6_V6ONLY` option on this socket.
+    ///
+    /// This is the same as [`TcpStream::only_v6`][other].
+    ///
+    /// [other]: struct.TcpBuilder.html#method.only_v6
+    pub fn only_v6(&self, only_v6: bool) -> io::Result<&Self> {
+        set_opt(self.as_sock(), v(IPPROTO_IPV6), IPV6_V6ONLY, only_v6 as c_int)
+            .map(|()| self)
+    }
+
+    /// Set value for the `SO_REUSEADDR` option on this socket.
+    ///
+    /// This is the same as [`TcpBuilder::reuse_address`][other].
+    ///
+    /// [other]: struct.TcpBuilder.html#method.reuse_address
+    pub fn reuse_address(&self, reuse: bool) -> io::Result<&Self> {
+        set_opt(self.as_sock(), SOL_SOCKET, SO_REUSEADDR,
+               reuse as c_int).map(|()| self)
+    }
+
+    /// Check the `SO_REUSEADDR` option on this socket.
+    pub fn get_reuse_address(&self) -> io::Result<bool> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_REUSEADDR).map(int2bool)
+    }
+
+    /// Get the value of the `SO_ERROR` option on this socket.
+    ///
+    /// This will retrieve the stored error in the underlying socket, clearing
+    /// the field in the process. This can be useful for checking errors between
+    /// calls.
+    pub fn take_error(&self) -> io::Result<Option<io::Error>> {
+        get_opt(self.as_sock(), SOL_SOCKET, SO_ERROR).map(int2err)
+    }
+}
diff --git a/third_party/rust/net2/src/lib.rs b/third_party/rust/net2/src/lib.rs
new file mode 100644
index 0000000000..a4b460e255
--- /dev/null
+++ b/third_party/rust/net2/src/lib.rs
@@ -0,0 +1,126 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Extensions to `std::net` networking types.
+//!
+//! This crate implements a number of extensions to the standard `std::net`
+//! networking types, hopefully being slated for inclusion into the standard
+//! library in the future. The goal of this crate is to expose all sorts of
+//! cross-platform and platform-specific configuration options of UDP/TCP
+//! sockets. System APIs are wrapped with as thin a layer as possible instead of
+//! bundling multiple actions into one API call.
+//!
+//! More information about the design of this crate can be found in the
+//! [associated rfc][rfc]
+//!
+//! [rfc]: https://github.com/rust-lang/rfcs/pull/1158
+//!
+//! # Examples
+//!
+//! ```no_run
+//! use net2::TcpBuilder;
+//!
+//! let tcp = TcpBuilder::new_v4().unwrap();
+//! tcp.reuse_address(true).unwrap()
+//!    .only_v6(false).unwrap();
+//!
+//! let mut stream = tcp.connect("127.0.0.1:80").unwrap();
+//!
+//! // use `stream` as a TcpStream
+//! ```
+
+#![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
+       html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
+       html_root_url = "https://doc.rust-lang.org/net2-rs")]
+#![deny(missing_docs, warnings)]
+
+// Silence warnings about deprecated try!() usage
+#![allow(deprecated)]
+
+#![cfg_attr(target_os = "wasi", feature(wasi_ext))]
+
+#[cfg(any(target_os = "wasi", unix))] extern crate libc;
+
+#[cfg(windows)] extern crate winapi;
+
+#[macro_use] extern crate cfg_if;
+
+use std::io;
+use std::ops::Neg;
+use std::net::{ToSocketAddrs, SocketAddr};
+
+use utils::{One, NetInt};
+
+mod tcp;
+mod udp;
+mod socket;
+mod ext;
+mod utils;
+
+#[cfg(unix)] #[path = "sys/unix/mod.rs"] mod sys;
+#[cfg(windows)] #[path = "sys/windows/mod.rs"] mod sys;
+#[cfg(target_os = "wasi")] #[path = "sys/wasi/mod.rs"] mod sys;
+#[cfg(all(unix, not(any(target_os = "solaris", target_os = "illumos"))))] pub mod unix;
+
+pub use tcp::TcpBuilder;
+pub use udp::UdpBuilder;
+pub use ext::{TcpStreamExt, TcpListenerExt, UdpSocketExt};
+
+fn one_addr<T: ToSocketAddrs>(tsa: T) -> io::Result<SocketAddr> {
+    let mut addrs = try!(tsa.to_socket_addrs());
+    let addr = match addrs.next() {
+        Some(addr) => addr,
+        None => return Err(io::Error::new(io::ErrorKind::Other,
+                                          "no socket addresses could be resolved"))
+    };
+    if addrs.next().is_none() {
+        Ok(addr)
+    } else {
+        Err(io::Error::new(io::ErrorKind::Other,
+                           "more than one address resolved"))
+    }
+}
+
+fn cvt<T: One + PartialEq + Neg<Output=T>>(t: T) -> io::Result<T> {
+    let one: T = T::one();
+    if t == -one {
+        Err(io::Error::last_os_error())
+    } else {
+        Ok(t)
+    }
+}
+
+#[cfg(windows)]
+fn cvt_win<T: PartialEq + utils::Zero>(t: T) -> io::Result<T> {
+    if t == T::zero() {
+        Err(io::Error::last_os_error())
+    } else {
+        Ok(t)
+    }
+}
+
+fn hton<I: NetInt>(i: I) -> I { i.to_be() }
+
+fn ntoh<I: NetInt>(i: I) -> I { I::from_be(i) }
+
+trait AsInner {
+    type Inner;
+    fn as_inner(&self) -> &Self::Inner;
+}
+
+trait FromInner {
+    type Inner;
+    fn from_inner(inner: Self::Inner) -> Self;
+}
+
+trait IntoInner {
+    type Inner;
+    fn into_inner(self) -> Self::Inner;
+}
diff --git a/third_party/rust/net2/src/socket.rs b/third_party/rust/net2/src/socket.rs
new file mode 100644
index 0000000000..5b0f4935a9
--- /dev/null
+++ b/third_party/rust/net2/src/socket.rs
@@ -0,0 +1,260 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::fmt;
+use std::io;
+use std::mem;
+use std::net::{Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6};
+#[cfg(any(unix, target_os = "wasi"))]
+use libc::c_int;
+#[cfg(windows)]
+use winapi::ctypes::c_int;
+
+use sys;
+use sys::c;
+
+pub struct Socket {
+    inner: sys::Socket,
+}
+
+impl Socket {
+    pub fn new(family: c_int, ty: c_int) -> io::Result<Socket> {
+        Ok(Socket { inner: try!(sys::Socket::new(family, ty)) })
+    }
+
+    pub fn bind(&self, addr: &SocketAddr) -> io::Result<()> {
+        let (addr, len) = addr2raw(addr);
+        unsafe {
+            ::cvt(c::bind(self.inner.raw(), addr.as_ptr(), len as c::socklen_t)).map(|_| ())
+        }
+    }
+
+    pub fn listen(&self, backlog: i32) -> io::Result<()> {
+        unsafe {
+            ::cvt(c::listen(self.inner.raw(), backlog)).map(|_| ())
+        }
+    }
+
+    pub fn connect(&self, addr: &SocketAddr) -> io::Result<()> {
+        let (addr, len) = addr2raw(addr);
+        unsafe {
+            ::cvt(c::connect(self.inner.raw(), addr.as_ptr(), len)).map(|_| ())
+        }
+    }
+
+    pub fn getsockname(&self) -> io::Result<SocketAddr> {
+        unsafe {
+            let mut storage: c::sockaddr_storage = mem::zeroed();
+            let mut len = mem::size_of_val(&storage) as c::socklen_t;
+            try!(::cvt(c::getsockname(self.inner.raw(),
+                                      &mut storage as *mut _ as *mut _,
+                                      &mut len)));
+            raw2addr(&storage, len)
+        }
+    }
+}
+
+impl fmt::Debug for Socket {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        self.inner.raw().fmt(f)
+    }
+}
+
+impl ::AsInner for Socket {
+    type Inner = sys::Socket;
+    fn as_inner(&self) -> &sys::Socket { &self.inner }
+}
+
+impl ::FromInner for Socket {
+    type Inner = sys::Socket;
+    fn from_inner(sock: sys::Socket) -> Socket {
+        Socket { inner: sock }
+    }
+}
+
+impl ::IntoInner for Socket {
+    type Inner = sys::Socket;
+    fn into_inner(self) -> sys::Socket { self.inner }
+}
+
+/// A type with the same memory layout as `c::sockaddr`. Used in converting Rust level
+/// SocketAddr* types into their system representation. The benefit of this specific
+/// type over using `c::sockaddr_storage` is that this type is exactly as large as it
+/// needs to be and not a lot larger.
+#[repr(C)]
+pub(crate) union SocketAddrCRepr {
+    v4: c::sockaddr_in,
+    v6: c::sockaddr_in6,
+}
+
+impl SocketAddrCRepr {
+    pub(crate) fn as_ptr(&self) -> *const c::sockaddr {
+        self as *const _ as *const c::sockaddr
+    }
+}
+
+fn addr2raw(addr: &SocketAddr) -> (SocketAddrCRepr, c::socklen_t) {
+    match addr {
+        &SocketAddr::V4(ref v4) => addr2raw_v4(v4),
+        &SocketAddr::V6(ref v6) => addr2raw_v6(v6),
+    }
+}
+
+#[cfg(unix)]
+fn addr2raw_v4(addr: &SocketAddrV4) -> (SocketAddrCRepr, c::socklen_t) {
+    let sin_addr = c::in_addr {
+        s_addr: u32::from(*addr.ip()).to_be(),
+    };
+
+    let sockaddr = SocketAddrCRepr {
+        v4: c::sockaddr_in {
+            sin_family: c::AF_INET as c::sa_family_t,
+            sin_port: addr.port().to_be(),
+            sin_addr,
+            #[cfg(not(target_os = "haiku"))]
+            sin_zero: [0; 8],
+            #[cfg(target_os = "haiku")]
+            sin_zero: [0; 24],
+            #[cfg(any(
+                target_os = "dragonfly",
+                target_os = "freebsd",
+                target_os = "ios",
+                target_os = "macos",
+                target_os = "netbsd",
+                target_os = "openbsd",
+                target_os = "haiku",
+            ))]
+            sin_len: 0,
+        },
+    };
+    (sockaddr, mem::size_of::<c::sockaddr_in>() as c::socklen_t)
+}
+
+#[cfg(windows)]
+fn addr2raw_v4(addr: &SocketAddrV4) -> (SocketAddrCRepr, c::socklen_t) {
+    let sin_addr = unsafe {
+        let mut s_un = mem::zeroed::<c::in_addr_S_un>();
+        *s_un.S_addr_mut() = u32::from(*addr.ip()).to_be();
+        c::IN_ADDR { S_un: s_un }
+    };
+
+    let sockaddr = SocketAddrCRepr {
+        v4: c::sockaddr_in {
+            sin_family: c::AF_INET as c::sa_family_t,
+            sin_port: addr.port().to_be(),
+            sin_addr,
+            sin_zero: [0; 8],
+        },
+    };
+    (sockaddr, mem::size_of::<c::sockaddr_in>() as c::socklen_t)
+}
+
+#[cfg(unix)]
+fn addr2raw_v6(addr: &SocketAddrV6) -> (SocketAddrCRepr, c::socklen_t) {
+    let sin6_addr = {
+        let mut sin6_addr = unsafe { mem::zeroed::<c::in6_addr>() };
+        sin6_addr.s6_addr = addr.ip().octets();
+        sin6_addr
+    };
+
+    let sockaddr = SocketAddrCRepr {
+        v6: c::sockaddr_in6 {
+            sin6_family: c::AF_INET6 as c::sa_family_t,
+            sin6_port: addr.port().to_be(),
+            sin6_addr,
+            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",
+                target_os = "haiku",
+            ))]
+            sin6_len: 0,
+            #[cfg(any(target_os = "solaris", target_os = "illumos"))]
+            __sin6_src_id: 0,
+        },
+    };
+    (sockaddr, mem::size_of::<c::sockaddr_in6>() as c::socklen_t)
+}
+
+#[cfg(windows)]
+fn addr2raw_v6(addr: &SocketAddrV6) -> (SocketAddrCRepr, c::socklen_t) {
+    let sin6_addr = unsafe {
+        let mut u = mem::zeroed::<c::in6_addr_u>();
+        *u.Byte_mut() = addr.ip().octets();
+        c::IN6_ADDR { u }
+    };
+    let scope_id = unsafe {
+        let mut u = mem::zeroed::<c::SOCKADDR_IN6_LH_u>();
+        *u.sin6_scope_id_mut() = addr.scope_id();
+        u
+    };
+
+    let sockaddr = SocketAddrCRepr {
+        v6: c::sockaddr_in6 {
+            sin6_family: c::AF_INET6 as c::sa_family_t,
+            sin6_port: addr.port().to_be(),
+            sin6_addr,
+            sin6_flowinfo: addr.flowinfo(),
+            u: scope_id,
+        },
+    };
+    (sockaddr, mem::size_of::<c::sockaddr_in6>() as c::socklen_t)
+}
+
+fn raw2addr(storage: &c::sockaddr_storage, len: c::socklen_t) -> io::Result<SocketAddr> {
+    match storage.ss_family as c_int {
+        c::AF_INET => {
+            unsafe {
+                assert!(len as usize >= mem::size_of::<c::sockaddr_in>());
+                let sa = storage as *const _ as *const c::sockaddr_in;
+                let bits = c::sockaddr_in_u32(&(*sa));
+                let ip = Ipv4Addr::new((bits >> 24) as u8,
+                                       (bits >> 16) as u8,
+                                       (bits >> 8) as u8,
+                                       bits as u8);
+                Ok(SocketAddr::V4(SocketAddrV4::new(ip, ::ntoh((*sa).sin_port))))
+            }
+        }
+        c::AF_INET6 => {
+            unsafe {
+                assert!(len as usize >= mem::size_of::<c::sockaddr_in6>());
+
+                let sa = storage as *const _ as *const c::sockaddr_in6;
+                #[cfg(windows)]      let arr = (*sa).sin6_addr.u.Byte();
+                #[cfg(not(windows))] let arr = (*sa).sin6_addr.s6_addr;
+
+                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),
+                );
+
+                #[cfg(windows)]      let sin6_scope_id = *(*sa).u.sin6_scope_id();
+                #[cfg(not(windows))] let sin6_scope_id = (*sa).sin6_scope_id;
+
+                Ok(SocketAddr::V6(SocketAddrV6::new(ip,
+                                                    ::ntoh((*sa).sin6_port),
+                                                    (*sa).sin6_flowinfo,
+                                                    sin6_scope_id)))
+            }
+        }
+        _ => Err(io::Error::new(io::ErrorKind::InvalidInput, "invalid argument")),
+    }
+}
diff --git a/third_party/rust/net2/src/sys/unix/impls.rs b/third_party/rust/net2/src/sys/unix/impls.rs
new file mode 100644
index 0000000000..95c2fb8081
--- /dev/null
+++ b/third_party/rust/net2/src/sys/unix/impls.rs
@@ -0,0 +1,44 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::os::unix::io::{FromRawFd, AsRawFd};
+use libc::c_int;
+
+use {TcpBuilder, UdpBuilder, FromInner, AsInner};
+use socket::Socket;
+use sys;
+
+impl FromRawFd for TcpBuilder {
+    unsafe fn from_raw_fd(fd: c_int) -> TcpBuilder {
+        let sock = sys::Socket::from_inner(fd);
+        TcpBuilder::from_inner(Socket::from_inner(sock))
+    }
+}
+
+impl AsRawFd for TcpBuilder {
+    fn as_raw_fd(&self) -> c_int {
+        // TODO: this unwrap() is very bad
+        self.as_inner().borrow().as_ref().unwrap().as_inner().raw()
+    }
+}
+
+impl FromRawFd for UdpBuilder {
+    unsafe fn from_raw_fd(fd: c_int) -> UdpBuilder {
+        let sock = sys::Socket::from_inner(fd);
+        UdpBuilder::from_inner(Socket::from_inner(sock))
+    }
+}
+
+impl AsRawFd for UdpBuilder {
+    fn as_raw_fd(&self) -> c_int {
+        // TODO: this unwrap() is very bad
+        self.as_inner().borrow().as_ref().unwrap().as_inner().raw()
+    }
+}
diff --git a/third_party/rust/net2/src/sys/unix/mod.rs b/third_party/rust/net2/src/sys/unix/mod.rs
new file mode 100644
index 0000000000..cc8a60d01e
--- /dev/null
+++ b/third_party/rust/net2/src/sys/unix/mod.rs
@@ -0,0 +1,104 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+
+use std::io;
+use std::mem;
+use std::net::{TcpListener, TcpStream, UdpSocket};
+use std::os::unix::io::FromRawFd;
+use libc::{self, c_int};
+#[cfg(not(any(target_os = "emscripten", target_os = "haiku", target_os = "illumos", target_os = "solaris")))]
+use libc::{ioctl, FIOCLEX};
+
+mod impls;
+
+pub mod c {
+    pub use libc::*;
+
+    pub fn sockaddr_in_u32(sa: &sockaddr_in) -> u32 {
+        ::ntoh((*sa).sin_addr.s_addr)
+    }
+
+    pub fn in_addr_to_u32(addr: &in_addr) -> u32 {
+        ::ntoh(addr.s_addr)
+    }
+}
+
+pub struct Socket {
+    fd: c_int,
+}
+
+impl Socket {
+    #[cfg(not(any(target_os = "emscripten", target_os = "haiku", target_os = "illumos", target_os = "solaris")))]
+    pub fn new(family: c_int, ty: c_int) -> io::Result<Socket> {
+        unsafe {
+            // Linux >2.6.26 overloads the type argument to accept SOCK_CLOEXEC,
+            // avoiding a race with another thread running fork/exec between
+            // socket() and ioctl()
+            #[cfg(any(target_os = "linux", target_os = "android"))]
+            match ::cvt(libc::socket(family, ty | libc::SOCK_CLOEXEC, 0)) {
+                Ok(fd) => return Ok(Socket { fd: fd }),
+                // Older versions of Linux return EINVAL; fall back to ioctl
+                Err(ref e) if e.raw_os_error() == Some(libc::EINVAL) => {}
+                Err(e) => return Err(e),
+            }
+
+            let fd = try!(::cvt(libc::socket(family, ty, 0)));
+            ioctl(fd, FIOCLEX);
+            Ok(Socket { fd: fd })
+        }
+    }
+
+    // ioctl(FIOCLEX) is not supported by Solaris/illumos or emscripten,
+    // use fcntl(FD_CLOEXEC) instead
+    #[cfg(any(target_os = "emscripten", target_os = "haiku", target_os = "illumos", target_os = "solaris"))]
+    pub fn new(family: c_int, ty: c_int) -> io::Result<Socket> {
+        unsafe {
+            let fd = try!(::cvt(libc::socket(family, ty, 0)));
+            libc::fcntl(fd, libc::FD_CLOEXEC);
+            Ok(Socket { fd: fd })
+        }
+    }
+
+    pub fn raw(&self) -> c_int { self.fd }
+
+    fn into_fd(self) -> c_int {
+        let fd = self.fd;
+        mem::forget(self);
+        fd
+    }
+
+    pub fn into_tcp_listener(self) -> TcpListener {
+        unsafe { TcpListener::from_raw_fd(self.into_fd()) }
+    }
+
+    pub fn into_tcp_stream(self) -> TcpStream {
+        unsafe { TcpStream::from_raw_fd(self.into_fd()) }
+    }
+
+    pub fn into_udp_socket(self) -> UdpSocket {
+        unsafe { UdpSocket::from_raw_fd(self.into_fd()) }
+    }
+}
+
+impl ::FromInner for Socket {
+    type Inner = c_int;
+    fn from_inner(fd: c_int) -> Socket {
+        Socket { fd: fd }
+    }
+}
+
+impl Drop for Socket {
+    fn drop(&mut self) {
+        unsafe {
+            let _ = libc::close(self.fd);
+        }
+    }
+}
diff --git a/third_party/rust/net2/src/sys/wasi/impls.rs b/third_party/rust/net2/src/sys/wasi/impls.rs
new file mode 100644
index 0000000000..eef8094b60
--- /dev/null
+++ b/third_party/rust/net2/src/sys/wasi/impls.rs
@@ -0,0 +1,33 @@
+use std::os::wasi::io::{FromRawFd, AsRawFd};
+
+use {TcpBuilder, UdpBuilder, FromInner, AsInner};
+use socket::Socket;
+use sys::{self, c::__wasi_fd_t};
+
+impl FromRawFd for TcpBuilder {
+    unsafe fn from_raw_fd(fd: __wasi_fd_t) -> TcpBuilder {
+        let sock = sys::Socket::from_inner(fd);
+        TcpBuilder::from_inner(Socket::from_inner(sock))
+    }
+}
+
+impl AsRawFd for TcpBuilder {
+    fn as_raw_fd(&self) -> __wasi_fd_t {
+        // TODO: this unwrap() is very bad
+        self.as_inner().borrow().as_ref().unwrap().as_inner().raw() as __wasi_fd_t
+    }
+}
+
+impl FromRawFd for UdpBuilder {
+    unsafe fn from_raw_fd(fd: __wasi_fd_t) -> UdpBuilder {
+        let sock = sys::Socket::from_inner(fd);
+        UdpBuilder::from_inner(Socket::from_inner(sock))
+    }
+}
+
+impl AsRawFd for UdpBuilder {
+    fn as_raw_fd(&self) -> __wasi_fd_t {
+        // TODO: this unwrap() is very bad
+        self.as_inner().borrow().as_ref().unwrap().as_inner().raw() as __wasi_fd_t
+    }
+}
diff --git a/third_party/rust/net2/src/sys/wasi/mod.rs b/third_party/rust/net2/src/sys/wasi/mod.rs
new file mode 100644
index 0000000000..bbc507ed68
--- /dev/null
+++ b/third_party/rust/net2/src/sys/wasi/mod.rs
@@ -0,0 +1,185 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(non_camel_case_types)]
+use libc::{self, c_int, __wasi_fd_t};
+use std::io;
+use std::mem;
+use std::net::{TcpListener, TcpStream, UdpSocket};
+use std::os::wasi::io::FromRawFd;
+
+mod impls;
+
+pub mod c {
+    pub use libc::*;
+
+    pub type sa_family_t = u16;
+    pub type socklen_t = u32;
+    pub type in_port_t = u16;
+
+    pub const SOCK_DGRAM: c_int = 0x00;
+    pub const SOL_SOCKET: c_int = 0x00;
+    pub const SO_RCVBUF: c_int = 0x00;
+    pub const SO_SNDBUF: c_int = 0x00;
+    pub const TCP_NODELAY: c_int = 0x00;
+    pub const IPPROTO_TCP: c_int = 0x00;
+    pub const SO_RCVTIMEO: c_int = 0x00;
+    pub const SO_SNDTIMEO: c_int = 0x00;
+    pub const IPPROTO_IP: c_int = 0x00;
+    pub const IP_TTL: c_int = 0x00;
+    pub const IPPROTO_IPV6: c_int = 0x00;
+    pub const IPV6_V6ONLY: c_int = 0x00;
+    pub const SO_ERROR: c_int = 0x00;
+    pub const SO_LINGER: c_int = 0x00;
+    pub const SO_BROADCAST: c_int = 0x00;
+    pub const IP_MULTICAST_LOOP: c_int = 0x00;
+    pub const IP_MULTICAST_TTL: c_int = 0x00;
+    pub const IPV6_MULTICAST_HOPS: c_int = 0x00;
+    pub const IPV6_MULTICAST_LOOP: c_int = 0x00;
+    pub const IP_MULTICAST_IF: c_int = 0x00;
+    pub const IPV6_MULTICAST_IF: c_int = 0x00;
+    pub const IPV6_UNICAST_HOPS: c_int = 0x00;
+    pub const IP_ADD_MEMBERSHIP: c_int = 0x00;
+    pub const IPV6_ADD_MEMBERSHIP: c_int = 0x00;
+    pub const IP_DROP_MEMBERSHIP: c_int = 0x00;
+    pub const IPV6_DROP_MEMBERSHIP: c_int = 0x00;
+    pub const SO_REUSEADDR: c_int = 0x00;
+    pub const SOCK_STREAM: c_int = 0x00;
+    pub const AF_INET: c_int = 0x00;
+    pub const AF_INET6: c_int = 0x01;
+
+    #[repr(C)]
+    pub struct sockaddr_storage {
+        pub ss_family: sa_family_t,
+    }
+    #[repr(C)]
+    pub struct sockaddr {
+        pub sa_family: sa_family_t,
+        pub sa_data: [c_char; 14],
+    }
+
+    #[repr(C)]
+    pub struct sockaddr_in6 {
+        pub sin6_family: sa_family_t,
+        pub sin6_port: in_port_t,
+        pub sin6_flowinfo: u32,
+        pub sin6_addr: in6_addr,
+        pub sin6_scope_id: u32,
+    }
+
+    #[repr(C)]
+    pub struct sockaddr_in {
+        pub sin_family: sa_family_t,
+        pub sin_port: in_port_t,
+        pub sin_addr: in_addr,
+        pub sin_zero: [u8; 8],
+    }
+
+    #[repr(align(4))]
+    #[derive(Copy, Clone)]
+    pub struct in6_addr {
+        pub s6_addr: [u8; 16],
+    }
+
+    #[derive(Copy, Clone)]
+    pub struct ipv6_mreq {
+        pub ipv6mr_multiaddr: in6_addr,
+        pub ipv6mr_interface: c_uint,
+    }
+
+    pub type in_addr_t = u32;
+    #[derive(Copy, Clone)]
+    pub struct in_addr {
+        pub s_addr: in_addr_t,
+    }
+
+    #[derive(Copy, Clone)]
+    pub struct linger {
+        pub l_onoff: c_int,
+        pub l_linger: c_int,
+    }
+
+    #[derive(Copy, Clone)]
+    pub struct ip_mreq {
+        pub imr_multiaddr: in_addr,
+        pub imr_interface: in_addr,
+    }
+
+    pub unsafe fn getsockname(_socket: __wasi_fd_t, _address: *mut sockaddr,
+                    _address_len: *mut socklen_t) -> c_int {
+        unimplemented!()
+    }
+    pub unsafe fn connect(_socket: __wasi_fd_t, _address: *const sockaddr,
+                _len: socklen_t) -> c_int {
+        unimplemented!()
+    }
+    pub unsafe fn listen(_socket: __wasi_fd_t, _backlog: c_int) -> c_int {
+        unimplemented!()
+    }
+    pub unsafe fn bind(_socket: __wasi_fd_t, _address: *const sockaddr,
+            _address_len: socklen_t) -> c_int {
+        unimplemented!()
+    }
+
+    pub fn sockaddr_in_u32(sa: &sockaddr_in) -> u32 {
+        ::ntoh((*sa).sin_addr.s_addr)
+    }
+
+    pub fn in_addr_to_u32(addr: &in_addr) -> u32 {
+        ::ntoh(addr.s_addr)
+    }
+}
+
+pub struct Socket {
+    fd: __wasi_fd_t,
+}
+
+impl Socket {
+    pub fn new(_family: c_int, _ty: c_int) -> io::Result<Socket> {
+        unimplemented!()
+    }
+
+    pub fn raw(&self) -> libc::__wasi_fd_t {
+        self.fd
+    }
+
+    fn into_fd(self) -> libc::__wasi_fd_t {
+        let fd = self.fd;
+        mem::forget(self);
+        fd
+    }
+
+    pub fn into_tcp_listener(self) -> TcpListener {
+        unsafe { TcpListener::from_raw_fd(self.into_fd()) }
+    }
+
+    pub fn into_tcp_stream(self) -> TcpStream {
+        unsafe { TcpStream::from_raw_fd(self.into_fd()) }
+    }
+
+    pub fn into_udp_socket(self) -> UdpSocket {
+        unsafe { UdpSocket::from_raw_fd(self.into_fd()) }
+    }
+}
+
+impl ::FromInner for Socket {
+    type Inner = libc::__wasi_fd_t;
+    fn from_inner(fd: libc::__wasi_fd_t) -> Socket {
+        Socket { fd: fd }
+    }
+}
+
+impl Drop for Socket {
+    fn drop(&mut self) {
+        // unsafe {
+        //     let _ = libc::close(self.fd);
+        // }
+    }
+}
\ No newline at end of file
diff --git a/third_party/rust/net2/src/sys/windows/impls.rs b/third_party/rust/net2/src/sys/windows/impls.rs
new file mode 100644
index 0000000000..48e787ca20
--- /dev/null
+++ b/third_party/rust/net2/src/sys/windows/impls.rs
@@ -0,0 +1,44 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::os::windows::io::{FromRawSocket, RawSocket, AsRawSocket};
+use winapi::um::winsock2::SOCKET;
+
+use {TcpBuilder, UdpBuilder, FromInner, AsInner};
+use socket::Socket;
+use sys;
+
+impl FromRawSocket for TcpBuilder {
+    unsafe fn from_raw_socket(fd: RawSocket) -> TcpBuilder {
+        let sock = sys::Socket::from_inner(fd as SOCKET);
+        TcpBuilder::from_inner(Socket::from_inner(sock))
+    }
+}
+
+impl AsRawSocket for TcpBuilder {
+    fn as_raw_socket(&self) -> RawSocket {
+        // TODO: this unwrap() is very bad
+        self.as_inner().borrow().as_ref().unwrap().as_inner().raw() as RawSocket
+    }
+}
+
+impl FromRawSocket for UdpBuilder {
+    unsafe fn from_raw_socket(fd: RawSocket) -> UdpBuilder {
+        let sock = sys::Socket::from_inner(fd as SOCKET);
+        UdpBuilder::from_inner(Socket::from_inner(sock))
+    }
+}
+
+impl AsRawSocket for UdpBuilder {
+    fn as_raw_socket(&self) -> RawSocket {
+        // TODO: this unwrap() is very bad
+        self.as_inner().borrow().as_ref().unwrap().as_inner().raw() as RawSocket
+    }
+}
diff --git a/third_party/rust/net2/src/sys/windows/mod.rs b/third_party/rust/net2/src/sys/windows/mod.rs
new file mode 100644
index 0000000000..7086bec9dc
--- /dev/null
+++ b/third_party/rust/net2/src/sys/windows/mod.rs
@@ -0,0 +1,125 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(bad_style)]
+
+use std::io;
+use std::mem;
+use std::net::{TcpListener, TcpStream, UdpSocket};
+use std::os::windows::io::{RawSocket, FromRawSocket};
+use std::sync::{Once, ONCE_INIT};
+
+const HANDLE_FLAG_INHERIT: DWORD = 0x00000001;
+
+pub mod c {
+    pub use winapi::ctypes::*;
+    pub use winapi::um::handleapi::*;
+    pub use winapi::um::winbase::*;
+    pub use winapi::um::winsock2::*;
+    pub use winapi::um::ws2tcpip::*;
+    
+    pub use winapi::shared::inaddr::*;
+    pub use winapi::shared::in6addr::*;
+    pub use winapi::shared::minwindef::*;
+    pub use winapi::shared::ntdef::*;
+    pub use winapi::shared::ws2def::*;
+    pub use winapi::shared::ws2def::{SOCK_STREAM, SOCK_DGRAM};
+    pub use winapi::shared::ws2def::SOCKADDR as sockaddr;
+    pub use winapi::shared::ws2def::SOCKADDR_STORAGE as sockaddr_storage;
+    pub use winapi::shared::ws2def::SOCKADDR_IN as sockaddr_in;
+    pub use winapi::shared::ws2def::ADDRESS_FAMILY as sa_family_t;
+    pub use winapi::shared::ws2ipdef::*;
+    pub use winapi::shared::ws2ipdef::SOCKADDR_IN6_LH as sockaddr_in6;
+    pub use winapi::shared::ws2ipdef::IP_MREQ as ip_mreq;
+    pub use winapi::shared::ws2ipdef::IPV6_MREQ as ipv6_mreq;
+
+    pub fn sockaddr_in_u32(sa: &sockaddr_in) -> u32 {
+        ::ntoh(unsafe { *sa.sin_addr.S_un.S_addr() })
+    }
+
+    pub fn in_addr_to_u32(addr: &in_addr) -> u32 {
+        ::ntoh(unsafe { *addr.S_un.S_addr() })
+    }
+}
+
+use self::c::*;
+
+mod impls;
+
+fn init() {
+    static INIT: Once = ONCE_INIT;
+
+    INIT.call_once(|| {
+        // Initialize winsock through the standard library by just creating a
+        // dummy socket. Whether this is successful or not we drop the result as
+        // libstd will be sure to have initialized winsock.
+        let _ = UdpSocket::bind("127.0.0.1:34254");
+    });
+}
+
+pub struct Socket {
+    socket: SOCKET,
+}
+
+impl Socket {
+    pub fn new(family: c_int, ty: c_int) -> io::Result<Socket> {
+        init();
+        let socket = try!(unsafe {
+            match WSASocketW(family, ty, 0, 0 as *mut _, 0,
+                             WSA_FLAG_OVERLAPPED) {
+                INVALID_SOCKET => Err(io::Error::last_os_error()),
+                n => Ok(Socket { socket: n }),
+            }
+        });
+        try!(socket.set_no_inherit());
+        Ok(socket)
+    }
+
+    pub fn raw(&self) -> SOCKET { self.socket }
+
+    fn into_socket(self) -> SOCKET {
+        let socket = self.socket;
+        mem::forget(self);
+        socket
+    }
+
+    pub fn into_tcp_listener(self) -> TcpListener {
+        unsafe { TcpListener::from_raw_socket(self.into_socket() as RawSocket) }
+    }
+
+    pub fn into_tcp_stream(self) -> TcpStream {
+        unsafe { TcpStream::from_raw_socket(self.into_socket() as RawSocket) }
+    }
+
+    pub fn into_udp_socket(self) -> UdpSocket {
+        unsafe { UdpSocket::from_raw_socket(self.into_socket() as RawSocket) }
+    }
+
+    fn set_no_inherit(&self) -> io::Result<()> {
+        ::cvt_win(unsafe {
+            SetHandleInformation(self.socket as HANDLE, HANDLE_FLAG_INHERIT, 0)
+        }).map(|_| ())
+    }
+}
+
+impl ::FromInner for Socket {
+    type Inner = SOCKET;
+    fn from_inner(socket: SOCKET) -> Socket {
+        Socket { socket: socket }
+    }
+}
+
+impl Drop for Socket {
+    fn drop(&mut self) {
+        unsafe {
+            let _ = closesocket(self.socket);
+        }
+    }
+}
diff --git a/third_party/rust/net2/src/tcp.rs b/third_party/rust/net2/src/tcp.rs
new file mode 100644
index 0000000000..5a535dbb5c
--- /dev/null
+++ b/third_party/rust/net2/src/tcp.rs
@@ -0,0 +1,161 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::cell::RefCell;
+use std::io;
+use std::net::{SocketAddr, ToSocketAddrs, TcpListener, TcpStream};
+use std::fmt;
+
+use IntoInner;
+use socket::Socket;
+use sys::c;
+
+/// An "in progress" TCP socket which has not yet been connected or listened.
+///
+/// Allows configuration of a socket before one of these operations is executed.
+pub struct TcpBuilder {
+    socket: RefCell<Option<Socket>>,
+}
+
+impl TcpBuilder {
+    /// Constructs a new TcpBuilder with the `AF_INET` domain, the `SOCK_STREAM`
+    /// type, and with a protocol argument of 0.
+    ///
+    /// Note that passing other kinds of flags or arguments can be done through
+    /// the `FromRaw{Fd,Socket}` implementation.
+    pub fn new_v4() -> io::Result<TcpBuilder> {
+        Socket::new(c::AF_INET, c::SOCK_STREAM).map(::FromInner::from_inner)
+    }
+
+    /// Constructs a new TcpBuilder with the `AF_INET6` domain, the `SOCK_STREAM`
+    /// type, and with a protocol argument of 0.
+    ///
+    /// Note that passing other kinds of flags or arguments can be done through
+    /// the `FromRaw{Fd,Socket}` implementation.
+    pub fn new_v6() -> io::Result<TcpBuilder> {
+        Socket::new(c::AF_INET6, c::SOCK_STREAM).map(::FromInner::from_inner)
+    }
+
+    /// Binds this socket to the specified address.
+    ///
+    /// This function directly corresponds to the bind(2) function on Windows
+    /// and Unix.
+    pub fn bind<T>(&self, addr: T) -> io::Result<&TcpBuilder>
+        where T: ToSocketAddrs
+    {
+        self.with_socket(|sock| {
+            let addr = try!(::one_addr(addr));
+            sock.bind(&addr)
+        }).map(|()| self)
+    }
+
+    /// Mark a socket as ready to accept incoming connection requests using
+    /// accept()
+    ///
+    /// This function directly corresponds to the listen(2) function on Windows
+    /// and Unix.
+    ///
+    /// An error will be returned if `listen` or `connect` has already been
+    /// called on this builder.
+    pub fn listen(&self, backlog: i32) -> io::Result<TcpListener> {
+        self.with_socket(|sock| {
+            sock.listen(backlog)
+        }).and_then(|()| {
+            self.to_tcp_listener()
+        })
+    }
+
+    /// Initiate a connection on this socket to the specified address.
+    ///
+    /// This function directly corresponds to the connect(2) function on Windows
+    /// and Unix.
+    ///
+    /// An error will be returned if `listen` or `connect` has already been
+    /// called on this builder.
+    pub fn connect<T>(&self, addr: T) -> io::Result<TcpStream>
+        where T: ToSocketAddrs
+    {
+        self.with_socket(|sock| {
+            let err = io::Error::new(io::ErrorKind::Other,
+                                     "no socket addresses resolved");
+            try!(addr.to_socket_addrs()).fold(Err(err), |prev, addr| {
+                prev.or_else(|_| sock.connect(&addr))
+            })
+        }).and_then(|()| {
+            self.to_tcp_stream()
+        })
+    }
+
+    /// Converts this builder into a `TcpStream`
+    ///
+    /// This function will consume the internal socket and return it re-wrapped
+    /// as a `TcpStream`. An error will be returned if the internal socket has
+    /// already been consumed from a successful call to `connect`, `listen`,
+    /// etc.
+    pub fn to_tcp_stream(&self) -> io::Result<TcpStream> {
+        self.socket.borrow_mut().take().map(|s| s.into_inner().into_tcp_stream())
+            .ok_or(io::Error::new(io::ErrorKind::Other,
+                                  "socket has already been consumed"))
+    }
+
+    /// Converts this builder into a `TcpListener`
+    ///
+    /// This function will consume the internal socket and return it re-wrapped
+    /// as a `TcpListener`. An error will be returned if the internal socket has
+    /// already been consumed from a successful call to `connect`, `listen`,
+    /// etc.
+    pub fn to_tcp_listener(&self) -> io::Result<TcpListener> {
+        self.socket.borrow_mut().take()
+            .map(|s| s.into_inner().into_tcp_listener())
+            .ok_or(io::Error::new(io::ErrorKind::Other,
+                                  "socket has already been consumed"))
+    }
+
+    /// Returns the address of the local half of this TCP socket.
+    ///
+    /// An error will be returned if `listen` or `connect` has already been
+    /// called on this builder.
+    pub fn local_addr(&self) -> io::Result<SocketAddr> {
+        match *self.socket.borrow() {
+            Some(ref s) => s.getsockname(),
+            None => Err(io::Error::new(io::ErrorKind::Other,
+                                       "builder has already finished its socket")),
+        }
+    }
+
+    fn with_socket<F>(&self, f: F) -> io::Result<()>
+        where F: FnOnce(&Socket) -> io::Result<()>
+    {
+        match *self.socket.borrow() {
+            Some(ref s) => f(s),
+            None => Err(io::Error::new(io::ErrorKind::Other,
+                                       "builder has already finished its socket")),
+        }
+    }
+}
+
+impl fmt::Debug for TcpBuilder {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "TcpBuilder {{ socket: {:?} }}",
+               self.socket.borrow().as_ref().unwrap())
+    }
+}
+
+impl ::AsInner for TcpBuilder {
+    type Inner = RefCell<Option<Socket>>;
+    fn as_inner(&self) -> &RefCell<Option<Socket>> { &self.socket }
+}
+
+impl ::FromInner for TcpBuilder {
+    type Inner = Socket;
+    fn from_inner(sock: Socket) -> TcpBuilder {
+        TcpBuilder { socket: RefCell::new(Some(sock)) }
+    }
+}
diff --git a/third_party/rust/net2/src/udp.rs b/third_party/rust/net2/src/udp.rs
new file mode 100644
index 0000000000..d061ab5c6f
--- /dev/null
+++ b/third_party/rust/net2/src/udp.rs
@@ -0,0 +1,89 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::cell::RefCell;
+use std::fmt;
+use std::io;
+use std::net::{ToSocketAddrs, UdpSocket};
+
+use IntoInner;
+use socket::Socket;
+use sys::c;
+
+/// An "in progress" UDP socket which has not yet been connected.
+///
+/// Allows configuration of a socket before the socket is connected.
+pub struct UdpBuilder {
+    socket: RefCell<Option<Socket>>,
+}
+
+impl UdpBuilder {
+    /// Constructs a new UdpBuilder with the `AF_INET` domain, the `SOCK_DGRAM`
+    /// type, and with a protocol argument of 0.
+    ///
+    /// Note that passing other kinds of flags or arguments can be done through
+    /// the `FromRaw{Fd,Socket}` implementation.
+    pub fn new_v4() -> io::Result<UdpBuilder> {
+        Socket::new(c::AF_INET, c::SOCK_DGRAM).map(::FromInner::from_inner)
+    }
+
+    /// Constructs a new UdpBuilder with the `AF_INET6` domain, the `SOCK_DGRAM`
+    /// type, and with a protocol argument of 0.
+    ///
+    /// Note that passing other kinds of flags or arguments can be done through
+    /// the `FromRaw{Fd,Socket}` implementation.
+    pub fn new_v6() -> io::Result<UdpBuilder> {
+        Socket::new(c::AF_INET6, c::SOCK_DGRAM).map(::FromInner::from_inner)
+    }
+
+    /// Binds this socket to the specified address.
+    ///
+    /// This function directly corresponds to the bind(2) function on Windows
+    /// and Unix.
+    pub fn bind<T>(&self, addr: T) -> io::Result<UdpSocket>
+        where T: ToSocketAddrs
+    {
+        try!(self.with_socket(|sock| {
+            let addr = try!(::one_addr(addr));
+            sock.bind(&addr)
+        }));
+        Ok(self.socket.borrow_mut().take().unwrap().into_inner().into_udp_socket())
+    }
+
+    fn with_socket<F>(&self, f: F) -> io::Result<()>
+        where F: FnOnce(&Socket) -> io::Result<()>
+    {
+        match *self.socket.borrow() {
+            Some(ref s) => f(s),
+            None => Err(io::Error::new(io::ErrorKind::Other,
+                                       "builder has already finished its socket")),
+        }
+    }
+}
+
+impl fmt::Debug for UdpBuilder {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "UdpBuilder {{ socket: {:?} }}",
+               self.socket.borrow().as_ref().unwrap())
+    }
+}
+
+impl ::AsInner for UdpBuilder {
+    type Inner = RefCell<Option<Socket>>;
+    fn as_inner(&self) -> &RefCell<Option<Socket>> { &self.socket }
+}
+
+impl ::FromInner for UdpBuilder {
+    type Inner = Socket;
+    fn from_inner(sock: Socket) -> UdpBuilder {
+        UdpBuilder { socket: RefCell::new(Some(sock)) }
+    }
+}
+
diff --git a/third_party/rust/net2/src/unix.rs b/third_party/rust/net2/src/unix.rs
new file mode 100644
index 0000000000..a1e1c6f5e9
--- /dev/null
+++ b/third_party/rust/net2/src/unix.rs
@@ -0,0 +1,57 @@
+//! Unix-specific extensions to the `std::net` types.
+
+use std::io;
+use sys::c::{self, c_int};
+
+use {TcpBuilder, UdpBuilder};
+use ext::{self, AsSock};
+
+/// Unix-specific extensions for the `TcpBuilder` type in this library.
+pub trait UnixTcpBuilderExt {
+    /// Set value for the `SO_REUSEPORT` option on this socket.
+    ///
+    /// This indicates that further calls to `bind` may allow reuse of local
+    /// addresses. For IPv4 sockets this means that a socket may bind even when
+    /// there's a socket already listening on this port.
+    fn reuse_port(&self, reuse: bool) -> io::Result<&Self>;
+
+    /// Check the value of the `SO_REUSEPORT` option on this socket.
+    fn get_reuse_port(&self) -> io::Result<bool>;
+}
+
+impl UnixTcpBuilderExt for TcpBuilder {
+    fn reuse_port(&self, reuse: bool) -> io::Result<&Self> {
+        ext::set_opt(self.as_sock(), c::SOL_SOCKET, c::SO_REUSEPORT,
+                    reuse as c_int).map(|()| self)
+    }
+
+    fn get_reuse_port(&self) -> io::Result<bool> {
+        ext::get_opt(self.as_sock(), c::SOL_SOCKET, c::SO_REUSEPORT)
+            .map(ext::int2bool)
+    }
+}
+
+/// Unix-specific extensions for the `UdpBuilder` type in this library.
+pub trait UnixUdpBuilderExt {
+    /// Set value for the `SO_REUSEPORT` option on this socket.
+    ///
+    /// This indicates that further calls to `bind` may allow reuse of local
+    /// addresses. For IPv4 sockets this means that a socket may bind even when
+    /// there's a socket already listening on this port.
+    fn reuse_port(&self, reuse: bool) -> io::Result<&Self>;
+
+    /// Check the value of the `SO_REUSEPORT` option on this socket.
+    fn get_reuse_port(&self) -> io::Result<bool>;
+}
+
+impl UnixUdpBuilderExt for UdpBuilder {
+    fn reuse_port(&self, reuse: bool) -> io::Result<&Self> {
+        ext::set_opt(self.as_sock(), c::SOL_SOCKET, c::SO_REUSEPORT,
+                    reuse as c_int).map(|()| self)
+    }
+
+    fn get_reuse_port(&self) -> io::Result<bool> {
+        ext::get_opt(self.as_sock(), c::SOL_SOCKET, c::SO_REUSEPORT)
+            .map(ext::int2bool)
+    }
+}
diff --git a/third_party/rust/net2/src/utils.rs b/third_party/rust/net2/src/utils.rs
new file mode 100644
index 0000000000..21fe9d61fc
--- /dev/null
+++ b/third_party/rust/net2/src/utils.rs
@@ -0,0 +1,51 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+
+#[doc(hidden)]
+pub 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 { <$t>::to_be(*self) }
+    })*)
+}
+doit! { i8 i16 i32 i64 isize u8 u16 u32 u64 usize }
+
+#[doc(hidden)]
+pub trait One {
+    fn one() -> Self;
+}
+
+macro_rules! one {
+    ($($t:ident)*) => ($(
+        impl One for $t { fn one() -> $t { 1 } }
+    )*)
+}
+
+one! { i8 i16 i32 i64 isize u8 u16 u32 u64 usize }
+
+
+#[doc(hidden)]
+pub trait Zero {
+    fn zero() -> Self;
+}
+
+macro_rules! zero {
+    ($($t:ident)*) => ($(
+        impl Zero for $t { fn zero() -> $t { 0 } }
+    )*)
+}
+
+zero! { i8 i16 i32 i64 isize u8 u16 u32 u64 usize }
+