std: sys: net: uefi: tcp: Initial TcpListener support

Ayush1325 · Ayush1325 · commit 84e8a42bdf4e · 2025-10-25T23:02:34.000+05:30
Add support for binding and accepting TCP4 connections.

While testing, the following network options were used with QEMU + OVMF:
-nic user,hostfwd=tcp::12345-:12345

The default localhost address on qemu seems to be 10.0.2.15.

UEFI spec does not seem to state that the TCP Handle returned by the
Accept method has a ServiceBinding Protocol. So have made the
ServiceBinding Protocol optional.

Signed-off-by: Ayush Singh &lt;ayush@beagleboard.org&gt;
diff --git a/library/std/src/sys/net/connection/uefi/mod.rs b/library/std/src/sys/net/connection/uefi/mod.rs
@@ -16,26 +16,26 @@ pub struct TcpStream {
 }
 
 impl TcpStream {
+    fn new(inner: tcp::Tcp) -> Self {
+        Self {
+            inner,
+            read_timeout: Arc::new(Mutex::new(None)),
+            write_timeout: Arc::new(Mutex::new(None)),
+        }
+    }
+
     pub fn connect<A: ToSocketAddrs>(addr: A) -> io::Result<TcpStream> {
         return each_addr(addr, inner);
 
         fn inner(addr: &SocketAddr) -> io::Result<TcpStream> {
             let inner = tcp::Tcp::connect(addr, None)?;
-            Ok(TcpStream {
-                inner,
-                read_timeout: Arc::new(Mutex::new(None)),
-                write_timeout: Arc::new(Mutex::new(None)),
-            })
+            Ok(TcpStream::new(inner))
         }
     }
 
     pub fn connect_timeout(addr: &SocketAddr, timeout: Duration) -> io::Result<TcpStream> {
         let inner = tcp::Tcp::connect(addr, Some(timeout))?;
-        Ok(Self {
-            inner,
-            read_timeout: Arc::new(Mutex::new(None)),
-            write_timeout: Arc::new(Mutex::new(None)),
-        })
+        Ok(Self::new(inner))
     }
 
     pub fn set_read_timeout(&self, t: Option<Duration>) -> io::Result<()> {
@@ -150,16 +150,23 @@ pub struct TcpListener {
 }
 
 impl TcpListener {
-    pub fn bind<A: ToSocketAddrs>(_: A) -> io::Result<TcpListener> {
-        unsupported()
+    pub fn bind<A: ToSocketAddrs>(addr: A) -> io::Result<TcpListener> {
+        return each_addr(addr, inner);
+
+        fn inner(addr: &SocketAddr) -> io::Result<TcpListener> {
+            let inner = tcp::Tcp::bind(addr)?;
+            Ok(TcpListener { inner })
+        }
     }
 
     pub fn socket_addr(&self) -> io::Result<SocketAddr> {
-        unsupported()
+        self.inner.socket_addr()
     }
 
     pub fn accept(&self) -> io::Result<(TcpStream, SocketAddr)> {
-        unsupported()
+        let tcp = self.inner.accept()?;
+        let addr = tcp.peer_addr()?;
+        Ok((TcpStream::new(tcp), addr))
     }
 
     pub fn duplicate(&self) -> io::Result<TcpListener> {
diff --git a/library/std/src/sys/net/connection/uefi/tcp.rs b/library/std/src/sys/net/connection/uefi/tcp.rs
@@ -18,7 +18,24 @@ impl Tcp {
                 temp.connect(timeout)?;
                 Ok(Tcp::V4(temp))
             }
-            SocketAddr::V6(_) => todo!(),
+            SocketAddr::V6(_) => unsupported(),
+        }
+    }
+
+    pub(crate) fn bind(addr: &SocketAddr) -> io::Result<Self> {
+        match addr {
+            SocketAddr::V4(x) => {
+                let temp = tcp4::Tcp4::new()?;
+                temp.configure(false, None, Some(x))?;
+                Ok(Tcp::V4(temp))
+            }
+            SocketAddr::V6(_) => unsupported(),
+        }
+    }
+
+    pub(crate) fn accept(&self) -> io::Result<Self> {
+        match self {
+            Self::V4(client) => client.accept().map(Tcp::V4),
         }
     }
 
diff --git a/library/std/src/sys/net/connection/uefi/tcp4.rs b/library/std/src/sys/net/connection/uefi/tcp4.rs
@@ -3,7 +3,7 @@ use r_efi::protocols::tcp4;
 
 use crate::io;
 use crate::net::SocketAddrV4;
-use crate::ptr::NonNull;
+use crate::ptr::{self, NonNull};
 use crate::sync::atomic::{AtomicBool, Ordering};
 use crate::sys::pal::helpers;
 use crate::time::{Duration, Instant};
@@ -12,20 +12,21 @@ const TYPE_OF_SERVICE: u8 = 8;
 const TIME_TO_LIVE: u8 = 255;
 
 pub(crate) struct Tcp4 {
+    handle: NonNull<crate::ffi::c_void>,
     protocol: NonNull<tcp4::Protocol>,
     flag: AtomicBool,
-    #[expect(dead_code)]
     service_binding: helpers::ServiceProtocol,
 }
 
 const DEFAULT_ADDR: efi::Ipv4Address = efi::Ipv4Address { addr: [0u8; 4] };
 
 impl Tcp4 {
     pub(crate) fn new() -> io::Result<Self> {
-        let service_binding = helpers::ServiceProtocol::open(tcp4::SERVICE_BINDING_PROTOCOL_GUID)?;
-        let protocol = helpers::open_protocol(service_binding.child_handle(), tcp4::PROTOCOL_GUID)?;
+        let (service_binding, handle) =
+            helpers::ServiceProtocol::open(tcp4::SERVICE_BINDING_PROTOCOL_GUID)?;
+        let protocol = helpers::open_protocol(handle, tcp4::PROTOCOL_GUID)?;
 
-        Ok(Self { service_binding, protocol, flag: AtomicBool::new(false) })
+        Ok(Self { service_binding, handle, protocol, flag: AtomicBool::new(false) })
     }
 
     pub(crate) fn configure(
@@ -42,11 +43,14 @@ impl Tcp4 {
             (DEFAULT_ADDR, 0)
         };
 
-        // FIXME: Remove when passive connections with proper subnet handling are added
-        assert!(station_address.is_none());
-        let use_default_address = efi::Boolean::TRUE;
-        let (station_address, station_port) = (DEFAULT_ADDR, 0);
-        let subnet_mask = helpers::ipv4_to_r_efi(crate::net::Ipv4Addr::new(0, 0, 0, 0));
+        let use_default_address: r_efi::efi::Boolean = station_address.is_none().into();
+        let (station_address, station_port) = if let Some(x) = station_address {
+            (helpers::ipv4_to_r_efi(*x.ip()), x.port())
+        } else {
+            (DEFAULT_ADDR, 0)
+        };
+        let subnet_mask = crate::net::Ipv4Addr::new(255, 255, 255, 0);
+        let subnet_mask = helpers::ipv4_to_r_efi(subnet_mask);
 
         let mut config_data = tcp4::ConfigData {
             type_of_service: TYPE_OF_SERVICE,
@@ -60,7 +64,7 @@ impl Tcp4 {
                 station_port,
                 subnet_mask,
             },
-            control_option: crate::ptr::null_mut(),
+            control_option: ptr::null_mut(),
         };
 
         let r = unsafe { ((*protocol).configure)(protocol, &mut config_data) };
@@ -74,17 +78,55 @@ impl Tcp4 {
         let r = unsafe {
             ((*protocol).get_mode_data)(
                 protocol,
-                crate::ptr::null_mut(),
+                ptr::null_mut(),
                 &mut config_data,
-                crate::ptr::null_mut(),
-                crate::ptr::null_mut(),
-                crate::ptr::null_mut(),
+                ptr::null_mut(),
+                ptr::null_mut(),
+                ptr::null_mut(),
             )
         };
 
         if r.is_error() { Err(io::Error::from_raw_os_error(r.as_usize())) } else { Ok(config_data) }
     }
 
+    pub(crate) fn accept(&self) -> io::Result<Self> {
+        let evt = unsafe { self.create_evt() }?;
+        let completion_token =
+            tcp4::CompletionToken { event: evt.as_ptr(), status: Status::SUCCESS };
+        let mut listen_token =
+            tcp4::ListenToken { completion_token, new_child_handle: ptr::null_mut() };
+
+        let protocol = self.protocol.as_ptr();
+        let r = unsafe { ((*protocol).accept)(protocol, &mut listen_token) };
+        if r.is_error() {
+            return Err(io::Error::from_raw_os_error(r.as_usize()));
+        }
+
+        unsafe { self.wait_or_cancel(None, &mut listen_token.completion_token) }?;
+
+        if completion_token.status.is_error() {
+            Err(io::Error::from_raw_os_error(completion_token.status.as_usize()))
+        } else {
+            // EDK2 internals seem to assume a single ServiceBinding Protocol for TCP4 and TCP6, and
+            // thus does not use any service binding protocol data in destroying child sockets. It
+            // does seem to suggest that we need to cleanup even the protocols created by accept. To
+            // be on the safe side with other implementations, we will be using the same service
+            // binding protocol as the parent TCP4 handle.
+            //
+            // https://github.com/tianocore/edk2/blob/f80580f56b267c96f16f985dbf707b2f96947da4/NetworkPkg/TcpDxe/TcpDriver.c#L938
+
+            let handle = NonNull::new(listen_token.new_child_handle).unwrap();
+            let protocol = helpers::open_protocol(handle, tcp4::PROTOCOL_GUID)?;
+
+            Ok(Self {
+                handle,
+                service_binding: self.service_binding,
+                protocol,
+                flag: AtomicBool::new(false),
+            })
+        }
+    }
+
     pub(crate) fn connect(&self, timeout: Option<Duration>) -> io::Result<()> {
         let evt = unsafe { self.create_evt() }?;
         let completion_token =
@@ -263,6 +305,12 @@ impl Tcp4 {
     }
 }
 
+impl Drop for Tcp4 {
+    fn drop(&mut self) {
+        let _ = unsafe { self.service_binding.destroy_child(self.handle) };
+    }
+}
+
 extern "efiapi" fn toggle_atomic_flag(_: r_efi::efi::Event, ctx: *mut crate::ffi::c_void) {
     let flag = unsafe { AtomicBool::from_ptr(ctx.cast()) };
     flag.store(true, Ordering::Relaxed);
diff --git a/library/std/src/sys/pal/uefi/helpers.rs b/library/std/src/sys/pal/uefi/helpers.rs
@@ -650,34 +650,38 @@ pub(crate) fn get_device_path_from_map(map: &Path) -> io::Result<BorrowedDeviceP
 
 /// Helper for UEFI Protocols which are created and destroyed using
 /// [EFI_SERVICE_BINDING_PROTOCOL](https://uefi.org/specs/UEFI/2.11/11_Protocols_UEFI_Driver_Model.html#efi-service-binding-protocol)
+///
+/// # Invariant
+/// - `handle` must always be a valid UEFI handle corresponding to the `service_guid`.
+/// - Copying `ServiceProtocol` is sound as long as `handle` remains valid.
+/// - For most service binding protocols (in edk2 implementations), such handles remain valid
+///   for the lifetime of the UEFI environment — effectively `'static`.
+#[derive(Clone, Copy)]
 pub(crate) struct ServiceProtocol {
     service_guid: r_efi::efi::Guid,
     handle: NonNull<crate::ffi::c_void>,
-    child_handle: NonNull<crate::ffi::c_void>,
 }
 
 impl ServiceProtocol {
-    pub(crate) fn open(service_guid: r_efi::efi::Guid) -> io::Result<Self> {
+    /// Open a child handle on a service_binding protocol.
+    pub(crate) fn open(
+        service_guid: r_efi::efi::Guid,
+    ) -> io::Result<(Self, NonNull<crate::ffi::c_void>)> {
         let handles = locate_handles(service_guid)?;
 
         for handle in handles {
             if let Ok(protocol) = open_protocol::<service_binding::Protocol>(handle, service_guid) {
-                let Ok(child_handle) = Self::create_child(protocol) else {
-                    continue;
-                };
-
-                return Ok(Self { service_guid, handle, child_handle });
+                if let Ok(child_handle) = unsafe { Self::create_child(protocol) } {
+                    return Ok((Self { service_guid, handle }, child_handle));
+                }
             }
         }
 
         Err(io::const_error!(io::ErrorKind::NotFound, "no service binding protocol found"))
     }
 
-    pub(crate) fn child_handle(&self) -> NonNull<crate::ffi::c_void> {
-        self.child_handle
-    }
-
-    fn create_child(
+    // SAFETY: sbp must be a valid service binding protocol pointer
+    unsafe fn create_child(
         sbp: NonNull<service_binding::Protocol>,
     ) -> io::Result<NonNull<crate::ffi::c_void>> {
         let mut child_handle: r_efi::efi::Handle = crate::ptr::null_mut();
@@ -691,17 +695,17 @@ impl ServiceProtocol {
                 .ok_or(const_error!(io::ErrorKind::Other, "null child handle"))
         }
     }
-}
 
-impl Drop for ServiceProtocol {
-    fn drop(&mut self) {
-        if let Ok(sbp) = open_protocol::<service_binding::Protocol>(self.handle, self.service_guid)
-        {
-            // SAFETY: Child handle must be allocated by the current service binding protocol.
-            let _ = unsafe {
-                ((*sbp.as_ptr()).destroy_child)(sbp.as_ptr(), self.child_handle.as_ptr())
-            };
-        }
+    // SAFETY: Child handle must be allocated by the current service binding protocol and must be
+    // valid.
+    pub(crate) unsafe fn destroy_child(
+        &self,
+        handle: NonNull<crate::ffi::c_void>,
+    ) -> io::Result<()> {
+        let sbp = open_protocol::<service_binding::Protocol>(self.handle, self.service_guid)?;
+
+        let r = unsafe { ((*sbp.as_ptr()).destroy_child)(sbp.as_ptr(), handle.as_ptr()) };
+        if r.is_error() { Err(crate::io::Error::from_raw_os_error(r.as_usize())) } else { Ok(()) }
     }
 }
 
