diff --git a/libs/binder/Android.bp b/libs/binder/Android.bp
index 2027b6e..f34672c 100644
--- a/libs/binder/Android.bp
+++ b/libs/binder/Android.bp
@@ -123,6 +123,7 @@
         "RpcSession.cpp",
         "RpcServer.cpp",
         "RpcState.cpp",
+        "RpcTransportRaw.cpp",
         "Static.cpp",
         "Stability.cpp",
         "Status.cpp",
diff --git a/libs/binder/RpcTransportRaw.cpp b/libs/binder/RpcTransportRaw.cpp
new file mode 100644
index 0000000..953d233
--- /dev/null
+++ b/libs/binder/RpcTransportRaw.cpp
@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+#define LOG_TAG "RpcRawTransport"
+#include <log/log.h>
+
+#include <binder/RpcTransportRaw.h>
+
+#include "RpcState.h"
+
+using android::base::ErrnoError;
+using android::base::Result;
+
+namespace android {
+
+namespace {
+
+// RpcTransport with TLS disabled.
+class RpcTransportRaw : public RpcTransport {
+public:
+    explicit RpcTransportRaw(android::base::unique_fd socket) : mSocket(std::move(socket)) {}
+    Result<ssize_t> send(const void *buf, int size) override {
+        ssize_t ret = TEMP_FAILURE_RETRY(::send(mSocket.get(), buf, size, MSG_NOSIGNAL));
+        if (ret < 0) {
+            return ErrnoError() << "send()";
+        }
+        return ret;
+    }
+    Result<ssize_t> recv(void *buf, int size) override {
+        ssize_t ret = TEMP_FAILURE_RETRY(::recv(mSocket.get(), buf, size, MSG_NOSIGNAL));
+        if (ret < 0) {
+            return ErrnoError() << "recv()";
+        }
+        return ret;
+    }
+    Result<ssize_t> peek(void *buf, int size) override {
+        ssize_t ret = TEMP_FAILURE_RETRY(::recv(mSocket.get(), buf, size, MSG_PEEK | MSG_DONTWAIT));
+        if (ret < 0) {
+            return ErrnoError() << "recv(MSG_PEEK)";
+        }
+        return ret;
+    }
+    bool pending() override { return false; }
+    android::base::borrowed_fd pollSocket() const override { return mSocket; }
+
+private:
+    android::base::unique_fd mSocket;
+};
+
+// RpcTransportCtx with TLS disabled.
+class RpcTransportCtxRaw : public RpcTransportCtx {
+public:
+    std::unique_ptr<RpcTransport> newTransport(android::base::unique_fd fd) const {
+        return std::make_unique<RpcTransportRaw>(std::move(fd));
+    }
+};
+} // namespace
+
+std::unique_ptr<RpcTransportCtx> RpcTransportCtxFactoryRaw::newServerCtx() const {
+    return std::make_unique<RpcTransportCtxRaw>();
+}
+
+std::unique_ptr<RpcTransportCtx> RpcTransportCtxFactoryRaw::newClientCtx() const {
+    return std::make_unique<RpcTransportCtxRaw>();
+}
+
+const char *RpcTransportCtxFactoryRaw::toCString() const {
+    return "raw";
+}
+
+std::unique_ptr<RpcTransportCtxFactory> RpcTransportCtxFactoryRaw::make() {
+    return std::unique_ptr<RpcTransportCtxFactoryRaw>(new RpcTransportCtxFactoryRaw());
+}
+
+} // namespace android
diff --git a/libs/binder/include/binder/RpcTransport.h b/libs/binder/include/binder/RpcTransport.h
new file mode 100644
index 0000000..1778cae
--- /dev/null
+++ b/libs/binder/include/binder/RpcTransport.h
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+// Wraps the transport layer of RPC. Implementation may use plain sockets or TLS.
+
+#pragma once
+
+#include <memory>
+#include <string>
+
+#include <android-base/result.h>
+#include <android-base/unique_fd.h>
+
+namespace android {
+
+// Represents a socket connection.
+class RpcTransport {
+public:
+    virtual ~RpcTransport() = default;
+
+    // replacement of ::send(). errno may not be set if TLS is enabled.
+    virtual android::base::Result<ssize_t> send(const void *buf, int size) = 0;
+
+    // replacement of ::recv(). errno may not be set if TLS is enabled.
+    virtual android::base::Result<ssize_t> recv(void *buf, int size) = 0;
+
+    // replacement of ::recv(MSG_PEEK). errno may not be set if TLS is enabled.
+    //
+    // Implementation details:
+    // - For TLS, this may invoke syscalls and read data from the transport
+    // into an internal buffer in userspace. After that, pending() == true.
+    // - For raw sockets, this calls ::recv(MSG_PEEK), which leaves the data in the kernel buffer;
+    // pending() is always false.
+    virtual android::base::Result<ssize_t> peek(void *buf, int size) = 0;
+
+    // Returns true if there are data pending in a userspace buffer that RpcTransport holds.
+    //
+    // Implementation details:
+    // - For TLS, this does not invoke any syscalls or read any data from the
+    // transport. This only returns whether there are data pending in the internal buffer in
+    // userspace.
+    // - For raw sockets, this always returns false.
+    virtual bool pending() = 0;
+
+    // Returns fd for polling.
+    //
+    // Do not directly read / write on this raw fd!
+    [[nodiscard]] virtual android::base::borrowed_fd pollSocket() const = 0;
+
+protected:
+    RpcTransport() = default;
+};
+
+// Represents the context that generates the socket connection.
+class RpcTransportCtx {
+public:
+    virtual ~RpcTransportCtx() = default;
+    [[nodiscard]] virtual std::unique_ptr<RpcTransport> newTransport(
+            android::base::unique_fd fd) const = 0;
+
+protected:
+    RpcTransportCtx() = default;
+};
+
+// A factory class that generates RpcTransportCtx.
+class RpcTransportCtxFactory {
+public:
+    virtual ~RpcTransportCtxFactory() = default;
+    // Creates server context.
+    [[nodiscard]] virtual std::unique_ptr<RpcTransportCtx> newServerCtx() const = 0;
+
+    // Creates client context.
+    [[nodiscard]] virtual std::unique_ptr<RpcTransportCtx> newClientCtx() const = 0;
+
+    // Return a short description of this transport (e.g. "raw"). For logging / debugging / testing
+    // only.
+    [[nodiscard]] virtual const char *toCString() const = 0;
+
+protected:
+    RpcTransportCtxFactory() = default;
+};
+
+} // namespace android
diff --git a/libs/binder/include/binder/RpcTransportRaw.h b/libs/binder/include/binder/RpcTransportRaw.h
new file mode 100644
index 0000000..6fb1f92
--- /dev/null
+++ b/libs/binder/include/binder/RpcTransportRaw.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+// Wraps the transport layer of RPC. Implementation uses plain sockets.
+// Note: don't use directly. You probably want newServerRpcTransportCtx / newClientRpcTransportCtx.
+
+#pragma once
+
+#include <memory>
+
+#include <binder/RpcTransport.h>
+
+namespace android {
+
+// RpcTransportCtxFactory with TLS disabled.
+class RpcTransportCtxFactoryRaw : public RpcTransportCtxFactory {
+public:
+    static std::unique_ptr<RpcTransportCtxFactory> make();
+
+    std::unique_ptr<RpcTransportCtx> newServerCtx() const override;
+    std::unique_ptr<RpcTransportCtx> newClientCtx() const override;
+    const char* toCString() const override;
+
+private:
+    RpcTransportCtxFactoryRaw() = default;
+};
+
+} // namespace android