Use datagram_common in netlink

kernel/src/net/socket/netlink/route/bound.rs

@@ -10,6 +10,7 @@ use crate::{
             message::ProtocolSegment, route::kernel::get_netlink_route_kernel, table::BoundHandle,
             NetlinkSocketAddr,
         },
+        util::datagram_common,
         SendRecvFlags,
     },
     prelude::*,
@@ -18,6 +19,7 @@ use crate::{
 
 pub(super) struct BoundNetlinkRoute {
     handle: BoundHandle,
+    remote_addr: NetlinkSocketAddr,
     receive_queue: Mutex<VecDeque<RtnlMessage>>,
 }
 
@@ -25,18 +27,31 @@ impl BoundNetlinkRoute {
     pub(super) const fn new(handle: BoundHandle) -> Self {
         Self {
             handle,
+            remote_addr: NetlinkSocketAddr::new_unspecified(),
             receive_queue: Mutex::new(VecDeque::new()),
         }
     }
+}
 
-    pub(super) const fn addr(&self) -> NetlinkSocketAddr {
+impl datagram_common::Bound for BoundNetlinkRoute {
+    type Endpoint = NetlinkSocketAddr;
+
+    fn local_endpoint(&self) -> Self::Endpoint {
         self.handle.addr()
     }
 
-    pub(super) fn try_send(
+    fn remote_endpoint(&self) -> Option<&Self::Endpoint> {
+        Some(&self.remote_addr)
+    }
+
+    fn set_remote_endpoint(&mut self, endpoint: &Self::Endpoint) {
+        self.remote_addr = *endpoint;
+    }
+
+    fn try_send(
         &self,
         reader: &mut dyn MultiRead,
-        remote: Option<&NetlinkSocketAddr>,
+        remote: &Self::Endpoint,
         flags: SendRecvFlags,
     ) -> Result<usize> {
         // TODO: Deal with flags
@@ -44,7 +59,6 @@ impl BoundNetlinkRoute {
             warn!("unsupported flags: {:?}", flags);
         }
 
-        if let Some(remote) = remote {
         // TODO: Further check whether other socket address can be supported.
         if *remote != NetlinkSocketAddr::new_unspecified() {
             return_errno_with_message!(
@@ -52,9 +66,6 @@ impl BoundNetlinkRoute {
                 "sending netlink route messages to user space is not supported"
             );
         }
-        } else {
-            // TODO: We should use the connected remote address, if any.
-        }
 
         let mut nlmsg = {
             let sum_lens = reader.sum_lens();
@@ -75,7 +86,7 @@ impl BoundNetlinkRoute {
             }
         };
 
-        let local_port = self.addr().port();
+        let local_port = self.handle.port();
         for segment in nlmsg.segments_mut() {
             // The header's PID should be the sender's port ID.
             // However, the sender can also leave it unspecified.
@@ -93,7 +104,7 @@ impl BoundNetlinkRoute {
         Ok(nlmsg.total_len())
     }
 
-    pub(super) fn try_receive(
+    fn try_recv(
         &self,
         writer: &mut dyn MultiWrite,
         flags: SendRecvFlags,
@@ -126,7 +137,7 @@ impl BoundNetlinkRoute {
         Ok((len, remote))
     }
 
-    pub(super) fn check_io_events(&self) -> IoEvents {
+    fn check_io_events(&self) -> IoEvents {
         let mut events = IoEvents::OUT;
 
         let receive_queue = self.receive_queue.lock();

kernel/src/net/socket/netlink/route/mod.rs

@@ -5,15 +5,16 @@
 use core::sync::atomic::{AtomicBool, Ordering};
 
 use bound::BoundNetlinkRoute;
-use takeable::Takeable;
 use unbound::UnboundNetlinkRoute;
 
 use super::NetlinkSocketAddr;
 use crate::{
     events::IoEvents,
     net::socket::{
-        options::SocketOption, private::SocketPrivate, MessageHeader, SendRecvFlags, Socket,
-        SocketAddr,
+        options::SocketOption,
+        private::SocketPrivate,
+        util::datagram_common::{select_remote_and_bind, Bound, Inner},
+        MessageHeader, SendRecvFlags, Socket, SocketAddr,
     },
     prelude::*,
     process::signal::{PollHandle, Pollable, Pollee},
@@ -26,96 +27,94 @@ mod message;
 mod unbound;
 
 pub struct NetlinkRouteSocket {
+    inner: RwMutex<Inner<UnboundNetlinkRoute, BoundNetlinkRoute>>,
+
     is_nonblocking: AtomicBool,
     pollee: Pollee,
-    inner: RwMutex<Takeable<Inner>>,
-}
-
-enum Inner {
-    Unbound(UnboundNetlinkRoute),
-    Bound(BoundNetlinkRoute),
 }
 
 impl NetlinkRouteSocket {
     pub fn new(is_nonblocking: bool) -> Self {
+        let unbound = UnboundNetlinkRoute::new();
         Self {
+            inner: RwMutex::new(Inner::Unbound(unbound)),
             is_nonblocking: AtomicBool::new(is_nonblocking),
             pollee: Pollee::new(),
-            inner: RwMutex::new(Takeable::new(Inner::Unbound(UnboundNetlinkRoute::new()))),
         }
     }
 
-    fn try_receive(
-        &self,
-        writer: &mut dyn MultiWrite,
-        flags: SendRecvFlags,
-    ) -> Result<(usize, NetlinkSocketAddr)> {
-        let inner = self.inner.read();
-
-        let bound = match inner.as_ref() {
-            Inner::Unbound(_) => {
-                return_errno_with_message!(Errno::EAGAIN, "the socket is not bound")
-            }
-            Inner::Bound(bound_netlink_route) => bound_netlink_route,
-        };
-
-        let received = bound.try_receive(writer, flags)?;
-        self.pollee.invalidate();
-
-        Ok(received)
-    }
-
     fn try_send(
         &self,
         reader: &mut dyn MultiRead,
         remote: Option<&NetlinkSocketAddr>,
         flags: SendRecvFlags,
     ) -> Result<usize> {
-        let inner = self.inner.read();
-
-        let bound = match inner.as_ref() {
-            Inner::Unbound(_) => todo!(),
-            Inner::Bound(bound) => bound,
-        };
-
-        let sent_bytes = bound.try_send(reader, remote, flags)?;
+        let sent_bytes = select_remote_and_bind(
+            &self.inner,
+            remote,
+            || {
+                self.inner
+                    .write()
+                    .bind_ephemeral(&NetlinkSocketAddr::new_unspecified(), &self.pollee)
+            },
+            |bound, remote_endpoint| bound.try_send(reader, remote_endpoint, flags),
+        )?;
         self.pollee.notify(IoEvents::OUT | IoEvents::IN);
 
         Ok(sent_bytes)
     }
 
-    fn check_io_events(&self) -> IoEvents {
-        let inner = self.inner.read();
-        match inner.as_ref() {
-            Inner::Unbound(unbound) => unbound.check_io_events(),
-            Inner::Bound(bound) => bound.check_io_events(),
-        }
+    fn try_recv(
+        &self,
+        writer: &mut dyn MultiWrite,
+        flags: SendRecvFlags,
+    ) -> Result<(usize, SocketAddr)> {
+        let recv_bytes = self
+            .inner
+            .read()
+            .try_recv(writer, flags)
+            .map(|(recv_bytes, remote_endpoint)| (recv_bytes, remote_endpoint.into()))?;
+        self.pollee.invalidate();
+
+        Ok(recv_bytes)
     }
 }
 
 impl Socket for NetlinkRouteSocket {
     fn bind(&self, socket_addr: SocketAddr) -> Result<()> {
-        let SocketAddr::Netlink(netlink_addr) = socket_addr else {
-            return_errno_with_message!(
-                Errno::EAFNOSUPPORT,
-                "the provided address is not netlink address"
-            );
-        };
+        let endpoint = socket_addr.try_into()?;
 
-        let mut inner = self.inner.write();
-        inner.borrow_result(|owned_inner| match owned_inner.bind(&netlink_addr) {
-            Ok(bound_inner) => (bound_inner, Ok(())),
-            Err((err, err_inner)) => (err_inner, Err(err)),
-        })
+        // FIXME: We need to further check the Linux behavior
+        // whether we should return error if the socket is bound.
+        // The socket may call `bind` syscall to join new multicast groups.
+        self.inner.write().bind(&endpoint, &self.pollee, ())
+    }
+
+    fn connect(&self, socket_addr: SocketAddr) -> Result<()> {
+        let endpoint = socket_addr.try_into()?;
+
+        self.inner.write().connect(&endpoint, &self.pollee)
     }
 
     fn addr(&self) -> Result<SocketAddr> {
-        let netlink_addr = match self.inner.read().as_ref() {
-            Inner::Unbound(_) => NetlinkSocketAddr::new_unspecified(),
-            Inner::Bound(bound) => bound.addr(),
-        };
+        let endpoint = self
+            .inner
+            .read()
+            .addr()
+            .unwrap_or(NetlinkSocketAddr::new_unspecified());
 
-        Ok(SocketAddr::Netlink(netlink_addr))
+        Ok(endpoint.into())
+    }
+
+    fn peer_addr(&self) -> Result<SocketAddr> {
+        let endpoint = self
+            .inner
+            .read()
+            .peer_addr()
+            .cloned()
+            .unwrap_or(NetlinkSocketAddr::new_unspecified());
+
+        Ok(endpoint.into())
     }
 
     fn sendmsg(
@@ -148,15 +147,11 @@ impl Socket for NetlinkRouteSocket {
         writers: &mut dyn MultiWrite,
         flags: SendRecvFlags,
     ) -> Result<(usize, MessageHeader)> {
-        let (received_len, addr) =
-            self.block_on(IoEvents::IN, || self.try_receive(writers, flags))?;
+        let (received_len, addr) = self.block_on(IoEvents::IN, || self.try_recv(writers, flags))?;
 
         // TODO: Receive control message
 
-        let message_header = {
-            let addr = SocketAddr::Netlink(addr);
-            MessageHeader::new(Some(addr), None)
-        };
+        let message_header = MessageHeader::new(Some(addr), None);
 
         Ok((received_len, message_header))
     }
@@ -180,28 +175,6 @@ impl SocketPrivate for NetlinkRouteSocket {
 impl Pollable for NetlinkRouteSocket {
     fn poll(&self, mask: IoEvents, poller: Option<&mut PollHandle>) -> IoEvents {
         self.pollee
-            .poll_with(mask, poller, || self.check_io_events())
-    }
-}
-
-impl Inner {
-    fn bind(self, addr: &NetlinkSocketAddr) -> core::result::Result<Self, (Error, Self)> {
-        let unbound = match self {
-            Inner::Unbound(unbound) => unbound,
-            Inner::Bound(bound) => {
-                // FIXME: We need to further check the Linux behavior
-                // whether we should return error if the socket is bound.
-                // The socket may call `bind` syscall to join new multicast groups.
-                return Err((
-                    Error::with_message(Errno::EINVAL, "the socket is already bound"),
-                    Self::Bound(bound),
-                ));
-            }
-        };
-
-        match unbound.bind(addr) {
-            Ok(bound) => Ok(Self::Bound(bound)),
-            Err((err, unbound)) => Err((err, Self::Unbound(unbound))),
-        }
+            .poll_with(mask, poller, || self.inner.read().check_io_events())
     }
 }

kernel/src/net/socket/netlink/route/unbound.rs

@@ -3,10 +3,12 @@
 use super::bound::BoundNetlinkRoute;
 use crate::{
     events::IoEvents,
-    net::socket::netlink::{
-        table::NETLINK_SOCKET_TABLE, NetlinkSocketAddr, StandardNetlinkProtocol,
+    net::socket::{
+        netlink::{table::NETLINK_SOCKET_TABLE, NetlinkSocketAddr, StandardNetlinkProtocol},
+        util::datagram_common,
     },
     prelude::*,
+    process::signal::Pollee,
 };
 
 pub(super) struct UnboundNetlinkRoute {
@@ -17,19 +19,40 @@ impl UnboundNetlinkRoute {
     pub(super) const fn new() -> Self {
         Self { _private: () }
     }
+}
 
-    pub(super) fn bind(
-        self,
-        addr: &NetlinkSocketAddr,
-    ) -> core::result::Result<BoundNetlinkRoute, (Error, Self)> {
-        let bound_handle = NETLINK_SOCKET_TABLE
-            .bind(StandardNetlinkProtocol::ROUTE as _, addr)
-            .map_err(|err| (err, self))?;
+impl datagram_common::Unbound for UnboundNetlinkRoute {
+    type Endpoint = NetlinkSocketAddr;
+    type BindOptions = ();
+
+    type Bound = BoundNetlinkRoute;
+
+    fn bind(
+        &mut self,
+        endpoint: &Self::Endpoint,
+        _pollee: &Pollee,
+        _options: Self::BindOptions,
+    ) -> Result<BoundNetlinkRoute> {
+        let bound_handle =
+            NETLINK_SOCKET_TABLE.bind(StandardNetlinkProtocol::ROUTE as _, endpoint)?;
 
         Ok(BoundNetlinkRoute::new(bound_handle))
     }
 
-    pub(super) fn check_io_events(&self) -> IoEvents {
+    fn bind_ephemeral(
+        &mut self,
+        _remote_endpoint: &Self::Endpoint,
+        _pollee: &Pollee,
+    ) -> Result<Self::Bound> {
+        let bound_handle = NETLINK_SOCKET_TABLE.bind(
+            StandardNetlinkProtocol::ROUTE as _,
+            &NetlinkSocketAddr::new_unspecified(),
+        )?;
+
+        Ok(BoundNetlinkRoute::new(bound_handle))
+    }
+
+    fn check_io_events(&self) -> IoEvents {
         IoEvents::OUT
     }
 }

kernel/src/net/socket/netlink/table/mod.rs

@@ -137,6 +137,10 @@ impl BoundHandle {
         }
     }
 
+    pub(super) const fn port(&self) -> PortNum {
+        self.port
+    }
+
     pub(super) const fn addr(&self) -> NetlinkSocketAddr {
         NetlinkSocketAddr::new(self.port, self.groups)
     }