1 files changed, 187 insertions, 0 deletions
diff --git a/libs/binder/rust/rpcbinder/src/server/android.rs b/libs/binder/rust/rpcbinder/src/server/android.rs
new file mode 100644
index 0000000000..2ab34472a9
--- /dev/null
+++ b/libs/binder/rust/rpcbinder/src/server/android.rs
@@ -0,0 +1,187 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+use crate::session::FileDescriptorTransportMode;
+use binder::{unstable_api::AsNative, SpIBinder};
+use binder_rpc_unstable_bindgen::ARpcServer;
+use foreign_types::{foreign_type, ForeignType, ForeignTypeRef};
+use std::ffi::CString;
+use std::io::{Error, ErrorKind};
+use std::os::unix::io::{IntoRawFd, OwnedFd};
+
+foreign_type! {
+    type CType = binder_rpc_unstable_bindgen::ARpcServer;
+    fn drop = binder_rpc_unstable_bindgen::ARpcServer_free;
+
+    /// A type that represents a foreign instance of RpcServer.
+    #[derive(Debug)]
+    pub struct RpcServer;
+    /// A borrowed RpcServer.
+    pub struct RpcServerRef;
+}
+
+/// SAFETY: The opaque handle can be cloned freely.
+unsafe impl Send for RpcServer {}
+/// SAFETY: The underlying C++ RpcServer class is thread-safe.
+unsafe impl Sync for RpcServer {}
+
+impl RpcServer {
+    /// Creates a binder RPC server, serving the supplied binder service implementation on the given
+    /// vsock port. Only connections from the given CID are accepted.
+    ///
+    // Set `cid` to libc::VMADDR_CID_ANY to accept connections from any client.
+    // Set `cid` to libc::VMADDR_CID_LOCAL to only bind to the local vsock interface.
+    pub fn new_vsock(mut service: SpIBinder, cid: u32, port: u32) -> Result<RpcServer, Error> {
+        let service = service.as_native_mut();
+
+        // SAFETY: Service ownership is transferring to the server and won't be valid afterward.
+        // Plus the binder objects are threadsafe.
+        unsafe {
+            Self::checked_from_ptr(binder_rpc_unstable_bindgen::ARpcServer_newVsock(
+                service, cid, port,
+            ))
+        }
+    }
+
+    /// Creates a binder RPC server, serving the supplied binder service implementation on the given
+    /// socket file descriptor. The socket should be bound to an address before calling this
+    /// function.
+    pub fn new_bound_socket(
+        mut service: SpIBinder,
+        socket_fd: OwnedFd,
+    ) -> Result<RpcServer, Error> {
+        let service = service.as_native_mut();
+
+        // SAFETY: Service ownership is transferring to the server and won't be valid afterward.
+        // Plus the binder objects are threadsafe.
+        // The server takes ownership of the socket FD.
+        unsafe {
+            Self::checked_from_ptr(binder_rpc_unstable_bindgen::ARpcServer_newBoundSocket(
+                service,
+                socket_fd.into_raw_fd(),
+            ))
+        }
+    }
+
+    /// Creates a binder RPC server that bootstraps sessions using an existing Unix domain socket
+    /// pair, with a given root IBinder object. Callers should create a pair of SOCK_STREAM Unix
+    /// domain sockets, pass one to the server and the other to the client. Multiple client session
+    /// can be created from the client end of the pair.
+    pub fn new_unix_domain_bootstrap(
+        mut service: SpIBinder,
+        bootstrap_fd: OwnedFd,
+    ) -> Result<RpcServer, Error> {
+        let service = service.as_native_mut();
+
+        // SAFETY: Service ownership is transferring to the server and won't be valid afterward.
+        // Plus the binder objects are threadsafe.
+        // The server takes ownership of the bootstrap FD.
+        unsafe {
+            Self::checked_from_ptr(binder_rpc_unstable_bindgen::ARpcServer_newUnixDomainBootstrap(
+                service,
+                bootstrap_fd.into_raw_fd(),
+            ))
+        }
+    }
+
+    /// Creates a binder RPC server, serving the supplied binder service implementation on the given
+    /// IP address and port.
+    pub fn new_inet(mut service: SpIBinder, address: &str, port: u32) -> Result<RpcServer, Error> {
+        let address = match CString::new(address) {
+            Ok(s) => s,
+            Err(e) => {
+                log::error!("Cannot convert {} to CString. Error: {:?}", address, e);
+                return Err(Error::from(ErrorKind::InvalidInput));
+            }
+        };
+        let service = service.as_native_mut();
+
+        // SAFETY: Service ownership is transferring to the server and won't be valid afterward.
+        // Plus the binder objects are threadsafe.
+        unsafe {
+            Self::checked_from_ptr(binder_rpc_unstable_bindgen::ARpcServer_newInet(
+                service,
+                address.as_ptr(),
+                port,
+            ))
+        }
+    }
+
+    unsafe fn checked_from_ptr(ptr: *mut ARpcServer) -> Result<RpcServer, Error> {
+        if ptr.is_null() {
+            return Err(Error::new(ErrorKind::Other, "Failed to start server"));
+        }
+        // SAFETY: Our caller must pass us a valid or null pointer, and we've checked that it's not
+        // null.
+        Ok(unsafe { RpcServer::from_ptr(ptr) })
+    }
+}
+
+impl RpcServerRef {
+    /// Sets the list of file descriptor transport modes supported by this server.
+    pub fn set_supported_file_descriptor_transport_modes(
+        &self,
+        modes: &[FileDescriptorTransportMode],
+    ) {
+        // SAFETY: Does not keep the pointer after returning does, nor does it
+        // read past its boundary. Only passes the 'self' pointer as an opaque handle.
+        unsafe {
+            binder_rpc_unstable_bindgen::ARpcServer_setSupportedFileDescriptorTransportModes(
+                self.as_ptr(),
+                modes.as_ptr(),
+                modes.len(),
+            )
+        }
+    }
+
+    /// Sets the max number of threads this Server uses for incoming client connections.
+    ///
+    /// This must be called before adding a client session. This corresponds
+    /// to the number of incoming connections to RpcSession objects in the
+    /// server, which will correspond to the number of outgoing connections
+    /// in client RpcSession objects. Specifically this is useful for handling
+    /// client-side callback connections.
+    ///
+    /// If this is not specified, this will be a single-threaded server.
+    pub fn set_max_threads(&self, count: usize) {
+        // SAFETY: RpcServerRef wraps a valid pointer to an ARpcServer.
+        unsafe { binder_rpc_unstable_bindgen::ARpcServer_setMaxThreads(self.as_ptr(), count) };
+    }
+
+    /// Starts a new background thread and calls join(). Returns immediately.
+    pub fn start(&self) {
+        // SAFETY: RpcServerRef wraps a valid pointer to an ARpcServer.
+        unsafe { binder_rpc_unstable_bindgen::ARpcServer_start(self.as_ptr()) };
+    }
+
+    /// Joins the RpcServer thread. The call blocks until the server terminates.
+    /// This must be called from exactly one thread.
+    pub fn join(&self) {
+        // SAFETY: RpcServerRef wraps a valid pointer to an ARpcServer.
+        unsafe { binder_rpc_unstable_bindgen::ARpcServer_join(self.as_ptr()) };
+    }
+
+    /// Shuts down the running RpcServer. Can be called multiple times and from
+    /// multiple threads. Called automatically during drop().
+    pub fn shutdown(&self) -> Result<(), Error> {
+        // SAFETY: RpcServerRef wraps a valid pointer to an ARpcServer.
+        if unsafe { binder_rpc_unstable_bindgen::ARpcServer_shutdown(self.as_ptr()) } {
+            Ok(())
+        } else {
+            Err(Error::from(ErrorKind::UnexpectedEof))
+        }
+    }
+}