add WASIp2 support via wasi-libc

.github/workflows/ci.yml

@@ -8,6 +8,7 @@ env:
   CARGO_TERM_COLOR: always
   RUST_BACKTRACE: full
   CI: true
+  WASMTIME_VERSION: 41.0.3
 
 permissions:
   contents: read #  to fetch code (actions/checkout)
@@ -83,6 +84,21 @@ jobs:
     - name: Check
       # We only run check allowing us to use newer features in tests.
       run: cargo check --all-features
+  TestWASI:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+    - uses: actions/checkout@v4
+    - uses: dtolnay/rust-toolchain@stable
+    - name: Setup `wasmtime`
+      run: |
+        curl -OL https://github.com/bytecodealliance/wasmtime/releases/download/v${WASMTIME_VERSION}/wasmtime-v${WASMTIME_VERSION}-x86_64-linux.tar.xz
+        tar xf wasmtime-v${WASMTIME_VERSION}-x86_64-linux.tar.xz
+        echo CARGO_TARGET_WASM32_WASIP2_RUNNER="$(pwd)/wasmtime-v${WASMTIME_VERSION}-x86_64-linux/wasmtime run -Sinherit-network" >> $GITHUB_ENV
+    - name: Install target
+      run: rustup target add wasm32-wasip2
+    - name: Tests
+      run: cargo test --target wasm32-wasip2 --all-features
   Nightly:
     runs-on: ubuntu-latest
     timeout-minutes: 10

src/io_source.rs

@@ -104,7 +104,11 @@ impl<T> DerefMut for IoSource<T> {
     }
 }
 
-#[cfg(any(unix, target_os = "hermit"))]
+#[cfg(any(
+    unix,
+    target_os = "hermit",
+    all(target_os = "wasi", not(target_env = "p1"))
+))]
 impl<T> event::Source for IoSource<T>
 where
     T: AsRawFd,
@@ -175,7 +179,7 @@ where
     }
 }
 
-#[cfg(target_os = "wasi")]
+#[cfg(all(target_os = "wasi", target_env = "p1"))]
 impl<T> event::Source for IoSource<T>
 where
     T: AsRawFd,

src/lib.rs

@@ -96,6 +96,14 @@ pub mod hermit {
     pub use crate::sys::SourceFd;
 }
 
+#[cfg(all(target_os = "wasi", not(target_env = "p1"), feature = "os-ext"))]
+#[cfg_attr(docsrs, doc(cfg(all(target_os = "wasi", feature = "os-ext"))))]
+pub mod wasi {
+    //! WASI-only extensions.
+
+    pub use crate::sys::SourceFd;
+}
+
 #[cfg(all(windows, feature = "os-ext"))]
 #[cfg_attr(docsrs, doc(cfg(all(windows, feature = "os-ext"))))]
 pub mod windows {

src/net/mod.rs

@@ -28,9 +28,9 @@
 mod tcp;
 pub use self::tcp::{TcpListener, TcpStream};
 
-#[cfg(not(target_os = "wasi"))]
+#[cfg(not(all(target_os = "wasi", target_env = "p1")))]
 mod udp;
-#[cfg(not(target_os = "wasi"))]
+#[cfg(not(all(target_os = "wasi", target_env = "p1")))]
 pub use self::udp::UdpSocket;
 
 #[cfg(unix)]

src/net/tcp/listener.rs

@@ -13,9 +13,13 @@ use std::{fmt, io};
 
 use crate::io_source::IoSource;
 use crate::net::TcpStream;
-#[cfg(any(unix, target_os = "hermit"))]
+#[cfg(any(
+    unix,
+    target_os = "hermit",
+    all(target_os = "wasi", not(target_env = "p1"))
+))]
 use crate::sys::tcp::set_reuseaddr;
-#[cfg(not(target_os = "wasi"))]
+#[cfg(not(all(target_os = "wasi", target_env = "p1")))]
 use crate::sys::{
     tcp::{bind, listen, new_for_addr},
     LISTEN_BACKLOG_SIZE,
@@ -62,10 +66,10 @@ impl TcpListener {
     /// 2. Set the `SO_REUSEADDR` option on the socket on Unix.
     /// 3. Bind the socket to the specified address.
     /// 4. Calls `listen` on the socket to prepare it to receive new connections.
-    #[cfg(not(target_os = "wasi"))]
+    #[cfg(not(all(target_os = "wasi", target_env = "p1")))]
     pub fn bind(addr: SocketAddr) -> io::Result<TcpListener> {
         let socket = new_for_addr(addr)?;
-        #[cfg(any(unix, target_os = "hermit"))]
+        #[cfg(any(unix, target_os = "hermit", target_os = "wasi"))]
         let listener = unsafe { TcpListener::from_raw_fd(socket) };
         #[cfg(windows)]
         let listener = unsafe { TcpListener::from_raw_socket(socket as _) };

src/net/tcp/stream.rs

@@ -13,7 +13,7 @@ use std::os::windows::io::{
 };
 
 use crate::io_source::IoSource;
-#[cfg(not(target_os = "wasi"))]
+#[cfg(not(all(target_os = "wasi", target_env = "p1")))]
 use crate::sys::tcp::{connect, new_for_addr};
 use crate::{event, Interest, Registry, Token};
 
@@ -87,10 +87,10 @@ impl TcpStream {
     /// entries in the routing cache.
     ///
     /// [write interest]: Interest::WRITABLE
-    #[cfg(not(target_os = "wasi"))]
+    #[cfg(not(all(target_os = "wasi", target_env = "p1")))]
     pub fn connect(addr: SocketAddr) -> io::Result<TcpStream> {
         let socket = new_for_addr(addr)?;
-        #[cfg(any(unix, target_os = "hermit"))]
+        #[cfg(any(unix, target_os = "hermit", target_os = "wasi"))]
         let stream = unsafe { TcpStream::from_raw_fd(socket) };
         #[cfg(windows)]
         let stream = unsafe { TcpStream::from_raw_socket(socket as _) };

src/net/udp.rs

@@ -36,6 +36,8 @@ use crate::{event, sys, Interest, Registry, Token};
 /// # use std::error::Error;
 /// #
 /// # fn main() -> Result<(), Box<dyn Error>> {
+/// # // Temporarily disabled on WASI pending https://github.com/WebAssembly/wasi-libc/pull/740:
+/// # if cfg!(target_os = "wasi") { return Ok(()) }
 /// // An Echo program:
 /// // SENDER -> sends a message.
 /// // ECHOER -> listens and prints the message received.
@@ -344,6 +346,8 @@ impl UdpSocket {
     /// # use std::error::Error;
     /// #
     /// # fn main() -> Result<(), Box<dyn Error>> {
+    /// # // WASI does not yet support broadcast.
+    /// # if cfg!(target_os = "wasi") { return Ok(()) }
     /// use mio::net::UdpSocket;
     ///
     /// let broadcast_socket = UdpSocket::bind("127.0.0.1:0".parse()?)?;
@@ -374,6 +378,8 @@ impl UdpSocket {
     /// # use std::error::Error;
     /// #
     /// # fn main() -> Result<(), Box<dyn Error>> {
+    /// # // WASI does not yet support broadcast.
+    /// # if cfg!(target_os = "wasi") { return Ok(()) }
     /// use mio::net::UdpSocket;
     ///
     /// let broadcast_socket = UdpSocket::bind("127.0.0.1:0".parse()?)?;

src/poll.rs

@@ -387,6 +387,8 @@ impl Poll {
     #[cfg_attr(not(all(feature = "os-poll", feature = "net")), doc = "```ignore")]
     /// # use std::error::Error;
     /// # fn main() -> Result<(), Box<dyn Error>> {
+    /// # // WASI does not yet support multithreading:
+    /// # if cfg!(target_os = "wasi") { return Ok(()) }
     /// use mio::{Events, Poll, Interest, Token};
     /// use mio::net::TcpStream;
     ///

src/sys/mod.rs

@@ -50,7 +50,11 @@ cfg_os_poll! {
     }
 }
 
-#[cfg(any(unix, target_os = "hermit"))]
+#[cfg(any(
+    unix,
+    target_os = "hermit",
+    all(target_os = "wasi", not(target_env = "p1"))
+))]
 cfg_os_poll! {
     mod unix;
     #[allow(unused_imports)]
@@ -63,10 +67,10 @@ cfg_os_poll! {
     pub use self::windows::*;
 }
 
-#[cfg(target_os = "wasi")]
+#[cfg(all(target_os = "wasi", target_env = "p1"))]
 cfg_os_poll! {
-    mod wasi;
-    pub(crate) use self::wasi::*;
+    mod wasip1;
+    pub(crate) use self::wasip1::*;
 }
 
 cfg_not_os_poll! {
@@ -115,7 +119,7 @@ pub(crate) const LISTEN_BACKLOG_SIZE: i32 = 128;
 /// is not implemented for them. Feel free to update this if the `libc` crate
 /// changes.
 #[allow(dead_code)]
-#[cfg(target_os = "hermit")]
+#[cfg(any(target_os = "hermit", target_os = "wasi"))]
 pub(crate) const LISTEN_BACKLOG_SIZE: i32 = 1024;
 
 #[allow(dead_code)]

src/sys/unix/mod.rs

@@ -50,6 +50,7 @@ cfg_os_poll! {
         target_os = "solaris",
         target_os = "vita",
         target_os = "cygwin",
+        target_os = "wasi",
     ), path = "selector/poll.rs")]
     mod selector;
     pub(crate) use self::selector::*;
@@ -103,7 +104,9 @@ cfg_os_poll! {
         target_os = "solaris",
         target_os = "vita",
         target_os = "cygwin",
+        all(target_os = "wasi", target_env = "p1")
     ), path = "waker/pipe.rs")]
+    #[cfg_attr(all(target_os = "wasi", not(target_env = "p1")), path = "waker/single_threaded.rs")]
     mod waker;
     // NOTE: the `Waker` type is expected in the selector module as the
     // `poll(2)` implementation needs to do some special stuff.
@@ -118,7 +121,7 @@ cfg_os_poll! {
 
         pub(crate) mod tcp;
         pub(crate) mod udp;
-        #[cfg(not(target_os = "hermit"))]
+        #[cfg(not(any(target_os = "hermit", target_os = "wasi")))]
         pub(crate) mod uds;
     }
 
@@ -153,8 +156,8 @@ cfg_os_poll! {
             target_os = "vita",
             target_os = "cygwin",
         ),
-        // Hermit doesn't support pipes.
         not(target_os = "hermit"),
+        not(target_os = "wasi"),
     ))]
     pub(crate) mod pipe;
 }

src/sys/unix/net.rs

@@ -27,6 +27,10 @@ pub(crate) fn new_socket(domain: libc::c_int, socket_type: libc::c_int) -> io::R
         target_os = "cygwin",
     ))]
     let socket_type = socket_type | libc::SOCK_NONBLOCK | libc::SOCK_CLOEXEC;
+    // WASI doesn't have the concept of `fork`ing or `exec`ing processes, so
+    // `SOCK_CLOEXEC` neither exists nor is relevant:
+    #[cfg(target_os = "wasi")]
+    let socket_type = socket_type | libc::SOCK_NONBLOCK;
     #[cfg(target_os = "nto")]
     let socket_type = socket_type | libc::SOCK_CLOEXEC;
 
@@ -108,7 +112,7 @@ pub(crate) fn socket_addr(addr: &SocketAddr) -> (SocketAddrCRepr, libc::socklen_
                 sin_family: libc::AF_INET as libc::sa_family_t,
                 sin_port: addr.port().to_be(),
                 sin_addr,
-                #[cfg(not(any(target_os = "haiku", target_os = "vita")))]
+                #[cfg(not(any(target_os = "haiku", target_os = "vita", target_os = "wasi")))]
                 sin_zero: [0; 8],
                 #[cfg(target_os = "haiku")]
                 sin_zero: [0; 24],