Rollup merge of #93158 - haraldh:wasi_sock_accept, r=dtolnay

wasi: implement `sock_accept` and enable networking

With the addition of `sock_accept()` to snapshot1, simple networking via a passed `TcpListener` is possible. This PR implements the basics to make a simple server work.

See also:
* [wasmtime tracking issue](https://github.com/bytecodealliance/wasmtime/issues/3730)
* [wasmtime PR](https://github.com/bytecodealliance/wasmtime/pull/3711)

TODO:
* [ ] Discussion of `SocketAddr` return value for `::accept()`

```rust
        Ok((
            TcpStream::from_inner(unsafe { Socket::from_raw_fd(fd as _) }),
            // WASI has no concept of SocketAddr yet
            // return an unspecified IPv4Addr
            SocketAddr::new(Ipv4Addr::UNSPECIFIED.into(), 0),
        ))
```

Cargo.lock

@@ -1473,7 +1473,7 @@ checksum = "7abc8dd8451921606d809ba32e95b6111925cd2906060d2dcc29c070220503eb"
 dependencies = [
  "cfg-if 0.1.10",
  "libc",
- "wasi",
+ "wasi 0.9.0+wasi-snapshot-preview1",
 ]
 
 [[package]]
@@ -1484,7 +1484,7 @@ checksum = "ee8025cf36f917e6a52cce185b7c7177689b838b7ec138364e50cc2277a56cf4"
 dependencies = [
  "cfg-if 0.1.10",
  "libc",
- "wasi",
+ "wasi 0.9.0+wasi-snapshot-preview1",
 ]
 
 [[package]]
@@ -4854,7 +4854,7 @@ dependencies = [
  "rustc-demangle",
  "std_detect",
  "unwind",
- "wasi",
+ "wasi 0.11.0+wasi-snapshot-preview1",
 ]
 
 [[package]]
@@ -5612,6 +5612,12 @@ name = "wasi"
 version = "0.9.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
+
+[[package]]
+name = "wasi"
+version = "0.11.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 dependencies = [
  "compiler_builtins",
  "rustc-std-workspace-alloc",

library/std/Cargo.toml

@@ -45,7 +45,7 @@ fortanix-sgx-abi = { version = "0.3.2", features = ['rustc-dep-of-std'] }
 hermit-abi = { version = "0.1.19", features = ['rustc-dep-of-std'] }
 
 [target.wasm32-wasi.dependencies]
-wasi = { version = "0.9.0", features = ['rustc-dep-of-std'], default-features = false }
+wasi = { version = "0.11.0", features = ['rustc-dep-of-std'], default-features = false }
 
 [features]
 backtrace = [

library/std/src/os/wasi/fs.rs

@@ -250,6 +250,21 @@ impl FileExt for fs::File {
     }
 
     fn advise(&self, offset: u64, len: u64, advice: u8) -> io::Result<()> {
+        let advice = match advice {
+            a if a == wasi::ADVICE_NORMAL.raw() => wasi::ADVICE_NORMAL,
+            a if a == wasi::ADVICE_SEQUENTIAL.raw() => wasi::ADVICE_SEQUENTIAL,
+            a if a == wasi::ADVICE_RANDOM.raw() => wasi::ADVICE_RANDOM,
+            a if a == wasi::ADVICE_WILLNEED.raw() => wasi::ADVICE_WILLNEED,
+            a if a == wasi::ADVICE_DONTNEED.raw() => wasi::ADVICE_DONTNEED,
+            a if a == wasi::ADVICE_NOREUSE.raw() => wasi::ADVICE_NOREUSE,
+            _ => {
+                return Err(io::Error::new_const(
+                    io::ErrorKind::InvalidInput,
+                    &"invalid parameter 'advice'",
+                ));
+            }
+        };
+
         self.as_inner().as_inner().advise(offset, len, advice)
     }
 

library/std/src/os/wasi/net/mod.rs

@@ -1,3 +1,23 @@
 //! WASI-specific networking functionality
 
 #![unstable(feature = "wasi_ext", issue = "71213")]
+
+use crate::io;
+use crate::net;
+use crate::sys_common::AsInner;
+
+/// WASI-specific extensions to [`std::net::TcpListener`].
+///
+/// [`std::net::TcpListener`]: crate::net::TcpListener
+pub trait TcpListenerExt {
+    /// Accept a socket.
+    ///
+    /// This corresponds to the `sock_accept` syscall.
+    fn sock_accept(&self, flags: u16) -> io::Result<u32>;
+}
+
+impl TcpListenerExt for net::TcpListener {
+    fn sock_accept(&self, flags: u16) -> io::Result<u32> {
+        self.as_inner().as_inner().as_inner().sock_accept(flags)
+    }
+}

library/std/src/sys/wasi/fd.rs

@@ -228,6 +228,10 @@ impl WasiFd {
         unsafe { wasi::path_remove_directory(self.as_raw_fd() as wasi::Fd, path).map_err(err2io) }
     }
 
+    pub fn sock_accept(&self, flags: wasi::Fdflags) -> io::Result<wasi::Fd> {
+        unsafe { wasi::sock_accept(self.as_raw_fd() as wasi::Fd, flags).map_err(err2io) }
+    }
+
     pub fn sock_recv(
         &self,
         ri_data: &mut [IoSliceMut<'_>],

library/std/src/sys/wasi/mod.rs

@@ -61,23 +61,26 @@ pub fn decode_error_kind(errno: i32) -> std_io::ErrorKind {
     if errno > u16::MAX as i32 || errno < 0 {
         return Uncategorized;
     }
-    match errno as u16 {
+
-        wasi::ERRNO_CONNREFUSED => ConnectionRefused,
+    match errno {
-        wasi::ERRNO_CONNRESET => ConnectionReset,
+        e if e == wasi::ERRNO_CONNREFUSED.raw().into() => ConnectionRefused,
-        wasi::ERRNO_PERM | wasi::ERRNO_ACCES => PermissionDenied,
+        e if e == wasi::ERRNO_CONNRESET.raw().into() => ConnectionReset,
-        wasi::ERRNO_PIPE => BrokenPipe,
+        e if e == wasi::ERRNO_PERM.raw().into() || e == wasi::ERRNO_ACCES.raw().into() => {
-        wasi::ERRNO_NOTCONN => NotConnected,
+            PermissionDenied
-        wasi::ERRNO_CONNABORTED => ConnectionAborted,
+        }
-        wasi::ERRNO_ADDRNOTAVAIL => AddrNotAvailable,
+        e if e == wasi::ERRNO_PIPE.raw().into() => BrokenPipe,
-        wasi::ERRNO_ADDRINUSE => AddrInUse,
+        e if e == wasi::ERRNO_NOTCONN.raw().into() => NotConnected,
-        wasi::ERRNO_NOENT => NotFound,
+        e if e == wasi::ERRNO_CONNABORTED.raw().into() => ConnectionAborted,
-        wasi::ERRNO_INTR => Interrupted,
+        e if e == wasi::ERRNO_ADDRNOTAVAIL.raw().into() => AddrNotAvailable,
-        wasi::ERRNO_INVAL => InvalidInput,
+        e if e == wasi::ERRNO_ADDRINUSE.raw().into() => AddrInUse,
-        wasi::ERRNO_TIMEDOUT => TimedOut,
+        e if e == wasi::ERRNO_NOENT.raw().into() => NotFound,
-        wasi::ERRNO_EXIST => AlreadyExists,
+        e if e == wasi::ERRNO_INTR.raw().into() => Interrupted,
-        wasi::ERRNO_AGAIN => WouldBlock,
+        e if e == wasi::ERRNO_INVAL.raw().into() => InvalidInput,
-        wasi::ERRNO_NOSYS => Unsupported,
+        e if e == wasi::ERRNO_TIMEDOUT.raw().into() => TimedOut,
-        wasi::ERRNO_NOMEM => OutOfMemory,
+        e if e == wasi::ERRNO_EXIST.raw().into() => AlreadyExists,
+        e if e == wasi::ERRNO_AGAIN.raw().into() => WouldBlock,
+        e if e == wasi::ERRNO_NOSYS.raw().into() => Unsupported,
+        e if e == wasi::ERRNO_NOMEM.raw().into() => OutOfMemory,
         _ => Uncategorized,
     }
 }
@@ -96,6 +99,6 @@ pub fn hashmap_random_keys() -> (u64, u64) {
     return ret;
 }
 
-fn err2io(err: wasi::Error) -> std_io::Error {
+fn err2io(err: wasi::Errno) -> std_io::Error {
-    std_io::Error::from_raw_os_error(err.raw_error().into())
+    std_io::Error::from_raw_os_error(err.raw().into())
 }

library/std/src/sys/wasi/net.rs

@@ -1,5 +1,6 @@
 #![deny(unsafe_op_in_unsafe_fn)]
 
+use super::err2io;
 use super::fd::WasiFd;
 use crate::convert::TryFrom;
 use crate::fmt;
@@ -87,24 +88,24 @@ impl TcpStream {
         unsupported()
     }
 
-    pub fn read(&self, _: &mut [u8]) -> io::Result<usize> {
+    pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
-        unsupported()
+        self.read_vectored(&mut [IoSliceMut::new(buf)])
     }
 
-    pub fn read_vectored(&self, _: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
+    pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
-        unsupported()
+        self.socket().as_inner().read(bufs)
     }
 
     pub fn is_read_vectored(&self) -> bool {
         true
     }
 
-    pub fn write(&self, _: &[u8]) -> io::Result<usize> {
+    pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
-        unsupported()
+        self.write_vectored(&[IoSlice::new(buf)])
     }
 
-    pub fn write_vectored(&self, _: &[IoSlice<'_>]) -> io::Result<usize> {
+    pub fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
-        unsupported()
+        self.socket().as_inner().write(bufs)
     }
 
     pub fn is_write_vectored(&self) -> bool {
@@ -155,8 +156,23 @@ impl TcpStream {
         unsupported()
     }
 
-    pub fn set_nonblocking(&self, _: bool) -> io::Result<()> {
+    pub fn set_nonblocking(&self, state: bool) -> io::Result<()> {
-        unsupported()
+        let fdstat = unsafe {
+            wasi::fd_fdstat_get(self.socket().as_inner().as_raw_fd() as wasi::Fd).map_err(err2io)?
+        };
+
+        let mut flags = fdstat.fs_flags;
+
+        if state {
+            flags |= wasi::FDFLAGS_NONBLOCK;
+        } else {
+            flags &= !wasi::FDFLAGS_NONBLOCK;
+        }
+
+        unsafe {
+            wasi::fd_fdstat_set_flags(self.socket().as_inner().as_raw_fd() as wasi::Fd, flags)
+                .map_err(err2io)
+        }
     }
 
     pub fn socket(&self) -> &Socket {
@@ -194,7 +210,16 @@ impl TcpListener {
     }
 
     pub fn accept(&self) -> io::Result<(TcpStream, SocketAddr)> {
-        unsupported()
+        let fd = unsafe {
+            wasi::sock_accept(self.as_inner().as_inner().as_raw_fd() as _, 0).map_err(err2io)?
+        };
+
+        Ok((
+            TcpStream::from_inner(unsafe { Socket::from_raw_fd(fd as _) }),
+            // WASI has no concept of SocketAddr yet
+            // return an unspecified IPv4Addr
+            SocketAddr::new(Ipv4Addr::UNSPECIFIED.into(), 0),
+        ))
     }
 
     pub fn duplicate(&self) -> io::Result<TcpListener> {
@@ -221,8 +246,23 @@ impl TcpListener {
         unsupported()
     }
 
-    pub fn set_nonblocking(&self, _: bool) -> io::Result<()> {
+    pub fn set_nonblocking(&self, state: bool) -> io::Result<()> {
-        unsupported()
+        let fdstat = unsafe {
+            wasi::fd_fdstat_get(self.socket().as_inner().as_raw_fd() as wasi::Fd).map_err(err2io)?
+        };
+
+        let mut flags = fdstat.fs_flags;
+
+        if state {
+            flags |= wasi::FDFLAGS_NONBLOCK;
+        } else {
+            flags &= !wasi::FDFLAGS_NONBLOCK;
+        }
+
+        unsafe {
+            wasi::fd_fdstat_set_flags(self.socket().as_inner().as_raw_fd() as wasi::Fd, flags)
+                .map_err(err2io)
+        }
     }
 
     pub fn socket(&self) -> &Socket {

library/std/src/sys/wasi/stdio.rs

@@ -104,7 +104,7 @@ impl io::Write for Stderr {
 pub const STDIN_BUF_SIZE: usize = crate::sys_common::io::DEFAULT_BUF_SIZE;
 
 pub fn is_ebadf(err: &io::Error) -> bool {
-    err.raw_os_error() == Some(wasi::ERRNO_BADF.into())
+    err.raw_os_error() == Some(wasi::ERRNO_BADF.raw().into())
 }
 
 pub fn panic_output() -> Option<impl io::Write> {

library/std/src/sys/wasi/thread.rs

@@ -41,8 +41,7 @@ impl Thread {
 
         let in_ = wasi::Subscription {
             userdata: USERDATA,
-            r#type: wasi::EVENTTYPE_CLOCK,
+            u: wasi::SubscriptionU { tag: 0, u: wasi::SubscriptionUU { clock } },
-            u: wasi::SubscriptionU { clock },
         };
         unsafe {
             let mut event: wasi::Event = mem::zeroed();
@@ -51,7 +50,10 @@ impl Thread {
                 (
                     Ok(1),
                     wasi::Event {
-                        userdata: USERDATA, error: 0, r#type: wasi::EVENTTYPE_CLOCK, ..
+                        userdata: USERDATA,
+                        error: wasi::ERRNO_SUCCESS,
+                        type_: wasi::EVENTTYPE_CLOCK,
+                        ..
                     },
                 ) => {}
                 _ => panic!("thread::sleep(): unexpected result of poll_oneoff"),

library/std/src/sys/wasi/time.rs

@@ -10,7 +10,7 @@ pub struct SystemTime(Duration);
 
 pub const UNIX_EPOCH: SystemTime = SystemTime(Duration::from_secs(0));
 
-fn current_time(clock: u32) -> Duration {
+fn current_time(clock: wasi::Clockid) -> Duration {
     let ts = unsafe {
         wasi::clock_time_get(
             clock, 1, // precision... seems ignored though?