diff --git a/libs/binder/include_rpc_unstable/binder_rpc_unstable.hpp b/libs/binder/include_rpc_unstable/binder_rpc_unstable.hpp
index 3a9cc95..f3b5fa0 100644
--- a/libs/binder/include_rpc_unstable/binder_rpc_unstable.hpp
+++ b/libs/binder/include_rpc_unstable/binder_rpc_unstable.hpp
@@ -23,6 +23,13 @@
 
 struct AIBinder;
 struct ARpcServer;
+struct ARpcSession;
+
+enum class ARpcSession_FileDescriptorTransportMode {
+    None,
+    Unix,
+    Trusty,
+};
 
 // Starts an RPC server on a given port and a given root IBinder object.
 // The server will only accept connections from the given CID.
@@ -40,6 +47,12 @@
 // could not be started.
 [[nodiscard]] ARpcServer* ARpcServer_newInitUnixDomain(AIBinder* service, const char* name);
 
+// Sets the list of supported file descriptor transport modes of this RPC server.
+void ARpcServer_setSupportedFileDescriptorTransportModes(
+        ARpcServer* handle,
+        const ARpcSession_FileDescriptorTransportMode modes[],
+        size_t modes_len);
+
 // Runs ARpcServer_join() in a background thread. Immediately returns.
 void ARpcServer_start(ARpcServer* server);
 
@@ -57,19 +70,40 @@
 // This automatically calls ARpcServer_shutdown().
 void ARpcServer_free(ARpcServer* server);
 
-AIBinder* VsockRpcClient(unsigned int cid, unsigned int port);
+// Allocates a new RpcSession object and returns an opaque handle to it.
+[[nodiscard]] ARpcSession* ARpcSession_new();
 
-// Gets the service via the RPC binder with Unix domain socket with the given
-// Unix socket `name`.
-// The final Unix domain socket path name is /dev/socket/`name`.
-AIBinder* UnixDomainRpcClient(const char* name);
+// Connects to an RPC server over vsock at a given CID on a given port.
+// Returns the root Binder object of the server.
+AIBinder* ARpcSession_setupVsockClient(ARpcSession* session, unsigned int cid,
+                                       unsigned int port);
 
-// Connect to an RPC server with preconnected file descriptors.
+// Connects to an RPC server over a Unix Domain Socket of the given name.
+// The final Unix Domain Socket path name is /dev/socket/`name`.
+// Returns the root Binder object of the server.
+AIBinder* ARpcSession_setupUnixDomainClient(ARpcSession* session, const char* name);
+
+// Connects to an RPC server with preconnected file descriptors.
 //
 // requestFd should connect to the server and return a valid file descriptor, or
 // -1 if connection fails.
 //
 // param will be passed to requestFd. Callers can use param to pass contexts to
 // the requestFd function.
-AIBinder* RpcPreconnectedClient(int (*requestFd)(void* param), void* param);
+AIBinder* ARpcSession_setupPreconnectedClient(ARpcSession* session,
+                                              int (*requestFd)(void* param),
+                                              void* param);
+
+// Sets the file descriptor transport mode for this session.
+void ARpcSession_setFileDescriptorTransportMode(ARpcSession* session,
+                                                ARpcSession_FileDescriptorTransportMode mode);
+
+// Sets the maximum number of incoming threads.
+void ARpcSession_setMaxIncomingThreads(ARpcSession* session, size_t threads);
+
+// Sets the maximum number of outgoing threads.
+void ARpcSession_setMaxOutgoingThreads(ARpcSession* session, size_t threads);
+
+// Decrements the refcount of the underlying RpcSession object.
+void ARpcSession_free(ARpcSession* session);
 }
diff --git a/libs/binder/libbinder_rpc_unstable.cpp b/libs/binder/libbinder_rpc_unstable.cpp
index 184d3f3..8dd9a87 100644
--- a/libs/binder/libbinder_rpc_unstable.cpp
+++ b/libs/binder/libbinder_rpc_unstable.cpp
@@ -35,22 +35,44 @@
 // Opaque handle for RpcServer.
 struct ARpcServer {};
 
-static sp<RpcServer> toRpcServer(ARpcServer* handle) {
-    auto ref = reinterpret_cast<RpcServer*>(handle);
-    return sp<RpcServer>::fromExisting(ref);
-}
+// Opaque handle for RpcSession.
+struct ARpcSession {};
 
-static ARpcServer* createRpcServerHandle(sp<RpcServer>& server) {
+template <typename A, typename T>
+static A* createObjectHandle(sp<T>& server) {
     auto ref = server.get();
     ref->incStrong(ref);
-    return reinterpret_cast<ARpcServer*>(ref);
+    return reinterpret_cast<A*>(ref);
 }
 
-static void freeRpcServerHandle(ARpcServer* handle) {
-    auto ref = reinterpret_cast<RpcServer*>(handle);
+template <typename T, typename A>
+static void freeObjectHandle(A* handle) {
+    LOG_ALWAYS_FATAL_IF(handle == nullptr, "Handle cannot be null");
+    auto ref = reinterpret_cast<T*>(handle);
     ref->decStrong(ref);
 }
 
+template <typename T, typename A>
+static sp<T> handleToStrongPointer(A* handle) {
+    LOG_ALWAYS_FATAL_IF(handle == nullptr, "Handle cannot be null");
+    auto ref = reinterpret_cast<T*>(handle);
+    return sp<T>::fromExisting(ref);
+}
+
+RpcSession::FileDescriptorTransportMode toTransportMode(
+        ARpcSession_FileDescriptorTransportMode mode) {
+    switch (mode) {
+        case ARpcSession_FileDescriptorTransportMode::None:
+            return RpcSession::FileDescriptorTransportMode::NONE;
+        case ARpcSession_FileDescriptorTransportMode::Unix:
+            return RpcSession::FileDescriptorTransportMode::UNIX;
+        case ARpcSession_FileDescriptorTransportMode::Trusty:
+            return RpcSession::FileDescriptorTransportMode::TRUSTY;
+        default:
+            return RpcSession::FileDescriptorTransportMode::NONE;
+    }
+}
+
 extern "C" {
 
 ARpcServer* ARpcServer_newVsock(AIBinder* service, unsigned int cid, unsigned int port) {
@@ -80,7 +102,7 @@
         });
     }
     server->setRootObject(AIBinder_toPlatformBinder(service));
-    return createRpcServerHandle(server);
+    return createObjectHandle<ARpcServer>(server);
 }
 
 ARpcServer* ARpcServer_newInitUnixDomain(AIBinder* service, const char* name) {
@@ -96,27 +118,47 @@
         return nullptr;
     }
     server->setRootObject(AIBinder_toPlatformBinder(service));
-    return createRpcServerHandle(server);
+    return createObjectHandle<ARpcServer>(server);
+}
+
+void ARpcServer_setSupportedFileDescriptorTransportModes(
+        ARpcServer* handle, const ARpcSession_FileDescriptorTransportMode modes[],
+        size_t modes_len) {
+    auto server = handleToStrongPointer<RpcServer>(handle);
+    std::vector<RpcSession::FileDescriptorTransportMode> modevec;
+    for (size_t i = 0; i < modes_len; i++) {
+        modevec.push_back(toTransportMode(modes[i]));
+    }
+    server->setSupportedFileDescriptorTransportModes(modevec);
 }
 
 void ARpcServer_start(ARpcServer* handle) {
-    toRpcServer(handle)->start();
+    handleToStrongPointer<RpcServer>(handle)->start();
 }
 
 void ARpcServer_join(ARpcServer* handle) {
-    toRpcServer(handle)->join();
+    handleToStrongPointer<RpcServer>(handle)->join();
 }
 
 void ARpcServer_shutdown(ARpcServer* handle) {
-    toRpcServer(handle)->shutdown();
+    handleToStrongPointer<RpcServer>(handle)->shutdown();
 }
 
 void ARpcServer_free(ARpcServer* handle) {
-    freeRpcServerHandle(handle);
+    freeObjectHandle<RpcServer>(handle);
 }
 
-AIBinder* VsockRpcClient(unsigned int cid, unsigned int port) {
+ARpcSession* ARpcSession_new() {
     auto session = RpcSession::make();
+    return createObjectHandle<ARpcSession>(session);
+}
+
+void ARpcSession_free(ARpcSession* handle) {
+    freeObjectHandle<RpcSession>(handle);
+}
+
+AIBinder* ARpcSession_setupVsockClient(ARpcSession* handle, unsigned int cid, unsigned int port) {
+    auto session = handleToStrongPointer<RpcSession>(handle);
     if (status_t status = session->setupVsockClient(cid, port); status != OK) {
         LOG(ERROR) << "Failed to set up vsock client with CID " << cid << " and port " << port
                    << " error: " << statusToString(status).c_str();
@@ -125,10 +167,10 @@
     return AIBinder_fromPlatformBinder(session->getRootObject());
 }
 
-AIBinder* UnixDomainRpcClient(const char* name) {
+AIBinder* ARpcSession_setupUnixDomainClient(ARpcSession* handle, const char* name) {
     std::string pathname(name);
     pathname = ANDROID_SOCKET_DIR "/" + pathname;
-    auto session = RpcSession::make();
+    auto session = handleToStrongPointer<RpcSession>(handle);
     if (status_t status = session->setupUnixDomainClient(pathname.c_str()); status != OK) {
         LOG(ERROR) << "Failed to set up Unix Domain RPC client with path: " << pathname
                    << " error: " << statusToString(status).c_str();
@@ -137,8 +179,9 @@
     return AIBinder_fromPlatformBinder(session->getRootObject());
 }
 
-AIBinder* RpcPreconnectedClient(int (*requestFd)(void* param), void* param) {
-    auto session = RpcSession::make();
+AIBinder* ARpcSession_setupPreconnectedClient(ARpcSession* handle, int (*requestFd)(void* param),
+                                              void* param) {
+    auto session = handleToStrongPointer<RpcSession>(handle);
     auto request = [=] { return unique_fd{requestFd(param)}; };
     if (status_t status = session->setupPreconnectedClient(unique_fd{}, request); status != OK) {
         LOG(ERROR) << "Failed to set up vsock client. error: " << statusToString(status).c_str();
@@ -146,4 +189,20 @@
     }
     return AIBinder_fromPlatformBinder(session->getRootObject());
 }
+
+void ARpcSession_setFileDescriptorTransportMode(ARpcSession* handle,
+                                                ARpcSession_FileDescriptorTransportMode mode) {
+    auto session = handleToStrongPointer<RpcSession>(handle);
+    session->setFileDescriptorTransportMode(toTransportMode(mode));
+}
+
+void ARpcSession_setMaxIncomingThreads(ARpcSession* handle, size_t threads) {
+    auto session = handleToStrongPointer<RpcSession>(handle);
+    session->setMaxIncomingThreads(threads);
+}
+
+void ARpcSession_setMaxOutgoingThreads(ARpcSession* handle, size_t threads) {
+    auto session = handleToStrongPointer<RpcSession>(handle);
+    session->setMaxOutgoingThreads(threads);
+}
 }
diff --git a/libs/binder/rust/rpcbinder/Android.bp b/libs/binder/rust/rpcbinder/Android.bp
index f70ebfc..afb73e9 100644
--- a/libs/binder/rust/rpcbinder/Android.bp
+++ b/libs/binder/rust/rpcbinder/Android.bp
@@ -68,10 +68,13 @@
     visibility: [":__subpackages__"],
     source_stem: "bindings",
     bindgen_flags: [
+        "--size_t-is-usize",
         "--blocklist-type",
         "AIBinder",
         "--raw-line",
         "use binder_ndk_sys::AIBinder;",
+        "--rustified-enum",
+        "ARpcSession_FileDescriptorTransportMode",
     ],
     rustlibs: [
         "libbinder_ndk_sys",
diff --git a/libs/binder/rust/rpcbinder/src/client.rs b/libs/binder/rust/rpcbinder/src/client.rs
deleted file mode 100644
index 48c787b..0000000
--- a/libs/binder/rust/rpcbinder/src/client.rs
+++ /dev/null
@@ -1,111 +0,0 @@
-/*
- * Copyright (C) 2022 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 binder::{unstable_api::new_spibinder, FromIBinder, SpIBinder, StatusCode, Strong};
-use std::ffi::CString;
-use std::os::{
-    raw::{c_int, c_void},
-    unix::io::RawFd,
-};
-
-/// Connects to an RPC Binder server over vsock.
-pub fn get_vsock_rpc_service(cid: u32, port: u32) -> Option<SpIBinder> {
-    // SAFETY: AIBinder returned by VsockRpcClient has correct reference count,
-    // and the ownership can safely be taken by new_spibinder.
-    unsafe { new_spibinder(binder_rpc_unstable_bindgen::VsockRpcClient(cid, port)) }
-}
-
-/// Connects to an RPC Binder server for a particular interface over vsock.
-pub fn get_vsock_rpc_interface<T: FromIBinder + ?Sized>(
-    cid: u32,
-    port: u32,
-) -> Result<Strong<T>, StatusCode> {
-    interface_cast(get_vsock_rpc_service(cid, port))
-}
-
-/// Connects to an RPC Binder server over Unix domain socket.
-pub fn get_unix_domain_rpc_service(socket_name: &str) -> Option<SpIBinder> {
-    let socket_name = match CString::new(socket_name) {
-        Ok(s) => s,
-        Err(e) => {
-            log::error!("Cannot convert {} to CString. Error: {:?}", socket_name, e);
-            return None;
-        }
-    };
-    // SAFETY: AIBinder returned by UnixDomainRpcClient has correct reference count,
-    // and the ownership can safely be taken by new_spibinder.
-    unsafe { new_spibinder(binder_rpc_unstable_bindgen::UnixDomainRpcClient(socket_name.as_ptr())) }
-}
-
-/// Connects to an RPC Binder server for a particular interface over Unix domain socket.
-pub fn get_unix_domain_rpc_interface<T: FromIBinder + ?Sized>(
-    socket_name: &str,
-) -> Result<Strong<T>, StatusCode> {
-    interface_cast(get_unix_domain_rpc_service(socket_name))
-}
-
-/// Connects to an RPC Binder server, using the given callback to get (and take ownership of)
-/// file descriptors already connected to it.
-pub fn get_preconnected_rpc_service(
-    mut request_fd: impl FnMut() -> Option<RawFd>,
-) -> Option<SpIBinder> {
-    // Double reference the factory because trait objects aren't FFI safe.
-    let mut request_fd_ref: RequestFd = &mut request_fd;
-    let param = &mut request_fd_ref as *mut RequestFd as *mut c_void;
-
-    // SAFETY: AIBinder returned by RpcPreconnectedClient has correct reference count, and the
-    // ownership can be safely taken by new_spibinder. RpcPreconnectedClient does not take ownership
-    // of param, only passing it to request_fd_wrapper.
-    unsafe {
-        new_spibinder(binder_rpc_unstable_bindgen::RpcPreconnectedClient(
-            Some(request_fd_wrapper),
-            param,
-        ))
-    }
-}
-
-type RequestFd<'a> = &'a mut dyn FnMut() -> Option<RawFd>;
-
-unsafe extern "C" fn request_fd_wrapper(param: *mut c_void) -> c_int {
-    // SAFETY: This is only ever called by RpcPreconnectedClient, within the lifetime of the
-    // BinderFdFactory reference, with param being a properly aligned non-null pointer to an
-    // initialized instance.
-    let request_fd_ptr = param as *mut RequestFd;
-    let request_fd = request_fd_ptr.as_mut().unwrap();
-    if let Some(fd) = request_fd() {
-        fd
-    } else {
-        -1
-    }
-}
-
-/// Connects to an RPC Binder server for a particular interface, using the given callback to get
-/// (and take ownership of) file descriptors already connected to it.
-pub fn get_preconnected_rpc_interface<T: FromIBinder + ?Sized>(
-    request_fd: impl FnMut() -> Option<RawFd>,
-) -> Result<Strong<T>, StatusCode> {
-    interface_cast(get_preconnected_rpc_service(request_fd))
-}
-
-fn interface_cast<T: FromIBinder + ?Sized>(
-    service: Option<SpIBinder>,
-) -> Result<Strong<T>, StatusCode> {
-    if let Some(service) = service {
-        FromIBinder::try_from(service)
-    } else {
-        Err(StatusCode::NAME_NOT_FOUND)
-    }
-}
diff --git a/libs/binder/rust/rpcbinder/src/lib.rs b/libs/binder/rust/rpcbinder/src/lib.rs
index 5495d20..a957385 100644
--- a/libs/binder/rust/rpcbinder/src/lib.rs
+++ b/libs/binder/rust/rpcbinder/src/lib.rs
@@ -16,11 +16,8 @@
 
 //! API for RPC Binder services.
 
-mod client;
 mod server;
+mod session;
 
-pub use client::{
-    get_preconnected_rpc_interface, get_preconnected_rpc_service, get_unix_domain_rpc_interface,
-    get_unix_domain_rpc_service, get_vsock_rpc_interface, get_vsock_rpc_service,
-};
 pub use server::{RpcServer, RpcServerRef};
+pub use session::{FileDescriptorTransportMode, RpcSession, RpcSessionRef};
diff --git a/libs/binder/rust/rpcbinder/src/server.rs b/libs/binder/rust/rpcbinder/src/server.rs
index cc7c571..242cb71 100644
--- a/libs/binder/rust/rpcbinder/src/server.rs
+++ b/libs/binder/rust/rpcbinder/src/server.rs
@@ -14,6 +14,7 @@
  * 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};
@@ -88,6 +89,22 @@
 }
 
 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(),
+            )
+        }
+    }
+
     /// Starts a new background thread and calls join(). Returns immediately.
     pub fn start(&self) {
         unsafe { binder_rpc_unstable_bindgen::ARpcServer_start(self.as_ptr()) };
diff --git a/libs/binder/rust/rpcbinder/src/session.rs b/libs/binder/rust/rpcbinder/src/session.rs
new file mode 100644
index 0000000..b5e11c2
--- /dev/null
+++ b/libs/binder/rust/rpcbinder/src/session.rs
@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2022 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 binder::unstable_api::new_spibinder;
+use binder::{FromIBinder, SpIBinder, StatusCode, Strong};
+use foreign_types::{foreign_type, ForeignType, ForeignTypeRef};
+use std::ffi::CString;
+use std::os::{
+    raw::{c_int, c_void},
+    unix::io::RawFd,
+};
+
+pub use binder_rpc_unstable_bindgen::ARpcSession_FileDescriptorTransportMode as FileDescriptorTransportMode;
+
+foreign_type! {
+    type CType = binder_rpc_unstable_bindgen::ARpcSession;
+    fn drop = binder_rpc_unstable_bindgen::ARpcSession_free;
+
+    /// A type that represents a foreign instance of RpcSession.
+    #[derive(Debug)]
+    pub struct RpcSession;
+    /// A borrowed RpcSession.
+    pub struct RpcSessionRef;
+}
+
+/// SAFETY - The opaque handle can be cloned freely.
+unsafe impl Send for RpcSession {}
+/// SAFETY - The underlying C++ RpcSession class is thread-safe.
+unsafe impl Sync for RpcSession {}
+
+impl RpcSession {
+    /// Allocates a new RpcSession object.
+    pub fn new() -> RpcSession {
+        // SAFETY - Takes ownership of the returned handle, which has correct refcount.
+        unsafe { RpcSession::from_ptr(binder_rpc_unstable_bindgen::ARpcSession_new()) }
+    }
+}
+
+impl Default for RpcSession {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl RpcSessionRef {
+    /// Sets the file descriptor transport mode for this session.
+    pub fn set_file_descriptor_transport_mode(&self, mode: FileDescriptorTransportMode) {
+        // SAFETY - Only passes the 'self' pointer as an opaque handle.
+        unsafe {
+            binder_rpc_unstable_bindgen::ARpcSession_setFileDescriptorTransportMode(
+                self.as_ptr(),
+                mode,
+            )
+        };
+    }
+
+    /// Sets the maximum number of incoming threads.
+    pub fn set_max_incoming_threads(&self, threads: usize) {
+        // SAFETY - Only passes the 'self' pointer as an opaque handle.
+        unsafe {
+            binder_rpc_unstable_bindgen::ARpcSession_setMaxIncomingThreads(self.as_ptr(), threads)
+        };
+    }
+
+    /// Sets the maximum number of outgoing threads.
+    pub fn set_max_outgoing_threads(&self, threads: usize) {
+        // SAFETY - Only passes the 'self' pointer as an opaque handle.
+        unsafe {
+            binder_rpc_unstable_bindgen::ARpcSession_setMaxOutgoingThreads(self.as_ptr(), threads)
+        };
+    }
+
+    /// Connects to an RPC Binder server over vsock for a particular interface.
+    pub fn setup_vsock_client<T: FromIBinder + ?Sized>(
+        &self,
+        cid: u32,
+        port: u32,
+    ) -> Result<Strong<T>, StatusCode> {
+        // SAFETY: AIBinder returned by ARpcSession_setupVsockClient has correct
+        // reference count, and the ownership can safely be taken by new_spibinder.
+        let service = unsafe {
+            new_spibinder(binder_rpc_unstable_bindgen::ARpcSession_setupVsockClient(
+                self.as_ptr(),
+                cid,
+                port,
+            ))
+        };
+        Self::get_interface(service)
+    }
+
+    /// Connects to an RPC Binder server over a names Unix Domain Socket for
+    /// a particular interface.
+    pub fn setup_unix_domain_client<T: FromIBinder + ?Sized>(
+        &self,
+        socket_name: &str,
+    ) -> Result<Strong<T>, StatusCode> {
+        let socket_name = match CString::new(socket_name) {
+            Ok(s) => s,
+            Err(e) => {
+                log::error!("Cannot convert {} to CString. Error: {:?}", socket_name, e);
+                return Err(StatusCode::NAME_NOT_FOUND);
+            }
+        };
+
+        // SAFETY: AIBinder returned by ARpcSession_setupUnixDomainClient has correct
+        // reference count, and the ownership can safely be taken by new_spibinder.
+        let service = unsafe {
+            new_spibinder(binder_rpc_unstable_bindgen::ARpcSession_setupUnixDomainClient(
+                self.as_ptr(),
+                socket_name.as_ptr(),
+            ))
+        };
+        Self::get_interface(service)
+    }
+
+    /// Connects to an RPC Binder server, using the given callback to get (and
+    /// take ownership of) file descriptors already connected to it.
+    pub fn setup_preconnected_client<T: FromIBinder + ?Sized>(
+        &self,
+        mut request_fd: impl FnMut() -> Option<RawFd>,
+    ) -> Result<Strong<T>, StatusCode> {
+        // Double reference the factory because trait objects aren't FFI safe.
+        let mut request_fd_ref: RequestFd = &mut request_fd;
+        let param = &mut request_fd_ref as *mut RequestFd as *mut c_void;
+
+        // SAFETY: AIBinder returned by RpcPreconnectedClient has correct reference count, and the
+        // ownership can be safely taken by new_spibinder. RpcPreconnectedClient does not take ownership
+        // of param, only passing it to request_fd_wrapper.
+        let service = unsafe {
+            new_spibinder(binder_rpc_unstable_bindgen::ARpcSession_setupPreconnectedClient(
+                self.as_ptr(),
+                Some(request_fd_wrapper),
+                param,
+            ))
+        };
+        Self::get_interface(service)
+    }
+
+    fn get_interface<T: FromIBinder + ?Sized>(
+        service: Option<SpIBinder>,
+    ) -> Result<Strong<T>, StatusCode> {
+        if let Some(service) = service {
+            FromIBinder::try_from(service)
+        } else {
+            Err(StatusCode::NAME_NOT_FOUND)
+        }
+    }
+}
+
+type RequestFd<'a> = &'a mut dyn FnMut() -> Option<RawFd>;
+
+unsafe extern "C" fn request_fd_wrapper(param: *mut c_void) -> c_int {
+    // SAFETY: This is only ever called by RpcPreconnectedClient, within the lifetime of the
+    // BinderFdFactory reference, with param being a properly aligned non-null pointer to an
+    // initialized instance.
+    let request_fd_ptr = param as *mut RequestFd;
+    let request_fd = request_fd_ptr.as_mut().unwrap();
+    request_fd().unwrap_or(-1)
+}