feat: Add version exchange on startup

Author: Berstanio

src/main/java/io/github/berstanio/pymobiledevice3/daemon/DaemonHandler.java

@@ -2,6 +2,7 @@
 
 import com.badlogic.gdx.jnigen.commons.HostDetection;
 import com.badlogic.gdx.jnigen.commons.Os;
+import io.github.berstanio.pymobiledevice3.ipc.PyMobileDevice3IPC;
 import io.github.berstanio.pymobiledevice3.venv.PyInstallation;
 
 import java.io.BufferedReader;
@@ -89,7 +90,8 @@ public static void startDaemon(PyInstallation installation) throws IOException {
         File portFile = getPortFile();
         Files.deleteIfExists(portFile.toPath());
         ProcessBuilder pb = new ProcessBuilder()
-                .command(installation.getPythonExecutable().getAbsolutePath() , "-u", installation.getHandler().getAbsolutePath(), portFile.getAbsolutePath());
+                .command(installation.getPythonExecutable().getAbsolutePath() , "-u", installation.getHandler().getAbsolutePath(), String.valueOf(
+                        PyMobileDevice3IPC.PROTOCOL_VERSION), portFile.getAbsolutePath());
 
         pb.redirectErrorStream(true);
         pb.redirectOutput(getLogFile());

src/main/java/io/github/berstanio/pymobiledevice3/ipc/PyMobileDevice3IPC.java

@@ -18,6 +18,11 @@
 import java.io.InputStreamReader;
 import java.io.PrintWriter;
 import java.net.Socket;
+import java.net.SocketTimeoutException;
+import java.nio.ByteBuffer;
+import java.nio.channels.SelectionKey;
+import java.nio.channels.Selector;
+import java.nio.channels.SocketChannel;
 import java.util.concurrent.ArrayBlockingQueue;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ConcurrentHashMap;
@@ -30,6 +35,9 @@ public class PyMobileDevice3IPC implements Closeable {
 
     private static final boolean DEBUG = System.getProperty("java.pymobiledevice3.debug") != null;
 
+    public static final int PROTOCOL_VERSION = 1;
+
+    private final int daemonProtocolVersion;
     private final Socket socket;
     private final BufferedReader reader;
     private final PrintWriter writer;
@@ -49,6 +57,12 @@ public PyMobileDevice3IPC() throws IOException {
             throw new IllegalStateException("Daemon is not running");
 
         socket = daemonSocket;
+
+        socket.getOutputStream().write(PROTOCOL_VERSION);
+        socket.getOutputStream().flush();
+
+        daemonProtocolVersion = readVersion();
+
         reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
         writer = new PrintWriter(socket.getOutputStream(), true);
 
@@ -101,6 +115,15 @@ public PyMobileDevice3IPC() throws IOException {
         readThread.start();
     }
 
+    private int readVersion() throws IOException {
+        try {
+            socket.setSoTimeout(2000);
+            return socket.getInputStream().read();
+        } finally {
+            socket.setSoTimeout(0);
+        }
+    }
+
     private <U> CompletableFuture<U> createRequest(JSONObject request, BiConsumer<CompletableFuture<U>, JSONObject> handler) {
         if (destroyed)
             return CompletableFuture.failedFuture(new PyMobileDevice3Error("Python process has been destroyed"));
@@ -306,6 +329,10 @@ public CompletableFuture<Void> ensureTunneldRunning() {
         });
     }
 
+    public int getDaemonProtocolVersion() {
+        return daemonProtocolVersion;
+    }
+
     public static void main(String[] args) throws IOException {
         if (!DaemonHandler.isDaemonRunning()) {
             PyInstallation installation = PyInstallationHandler.install(new File("build/pyenv/"));

src/main/resources/handler.py

@@ -29,12 +29,15 @@
 from pymobiledevice3.lockdown import create_using_usbmux
 import plistlib
 
+VERSION: int
+
 class IPCClient:
-    def __init__(self, sock, address):
+    def __init__(self, sock, address, version):
         self.sock = sock
         self.read_file = sock.makefile('r')
         self.write_file = sock.makefile('w')
         self.address = address
+        self.version = version
 
     def close(self):
         self.sock.close()
@@ -123,7 +126,7 @@ def remove_client(self, ipc_client):
     def add_client(self, ipc_client):
         self.clients[ipc_client.sock] = ipc_client
         self.socket_list.append(ipc_client.sock)
-        print(f"Connected {ipc_client.address}")
+        print(f"Connected {ipc_client.address} with version {ipc_client.version}")
 
 
     def shutdown(self):
@@ -350,6 +353,9 @@ def usbmux_forward_close(id, local_port, ipc_client):
     reply = {"id": id, "state": "completed"}
     write_dispatcher.write_reply(ipc_client, reply)
 
+def get_version(id, ipc_client):
+    reply = {"id": id, "state": "completed", "result": VERSION}
+    write_dispatcher.write_reply(ipc_client, reply)
 
 def handle_command(command, ipc_client):
     try:
@@ -393,6 +399,9 @@ def handle_command(command, ipc_client):
             reply = {"id": id, "state": "completed", "result": res}
             write_dispatcher.write_reply(ipc_client, reply)
             return
+        elif command_type == "get_version":
+            get_version(id, ipc_client)
+            return
 
         # Now come the device targetted functions
         device_id = res['device_id']
@@ -414,16 +423,19 @@ def handle_command(command, ipc_client):
 
 
 def main():
-    if len(sys.argv) < 2:
-        print("Usage: python handler.py <port_file>")
+    if len(sys.argv) < 3:
+        print("Usage: python handler.py <protocol_version> <port_file>")
         sys.exit(1)
 
+    global VERSION
+    VERSION = int(sys.argv[1])
+
     server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     server.bind(('localhost', 0))
     server.listen(5)
 
     port = server.getsockname()[1]
-    path = sys.argv[1]
+    path = sys.argv[2]
 
     with open(path, "w") as f:
         f.write(str(port))
@@ -435,6 +447,16 @@ def main():
     print(f"Start listening on port {port}")
     while True:
         client_socket, client_address = server.accept()
-        read_dispatcher.add_client(IPCClient(client_socket, client_address))
+        try:
+            reads, _, _ = select.select([client_socket], [], [], 2)
+            if client_socket not in reads:
+                raise RuntimeError()
+            java_protocol_version = client_socket.recv(1)[0]
+            client_socket.send(bytes([VERSION]))
+
+            read_dispatcher.add_client(IPCClient(client_socket, client_address, java_protocol_version))
+        except Exception:
+            print(f"{client_address}: Failed to send version")
+
 
 main()