Deprecate legacy SSH integration
[netconf.git] / netconf / netconf-netty-util / src / main / java / org / opendaylight / netconf / nettyutil / handler / ssh / client / AsyncSshHandler.java
index ffc52d1f15f689f59aee3cf85e7b17d1fefe7c81..32ebf5348e981178d099d7e77599291575a77fda 100644 (file)
@@ -16,14 +16,20 @@ import io.netty.channel.ChannelPromise;
 import io.netty.util.concurrent.Future;
 import io.netty.util.concurrent.FutureListener;
 import java.io.IOException;
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.VarHandle;
 import java.net.SocketAddress;
+import java.time.Duration;
 import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicBoolean;
+import org.checkerframework.checker.lock.qual.GuardedBy;
+import org.checkerframework.checker.lock.qual.Holding;
 import org.eclipse.jdt.annotation.Nullable;
 import org.opendaylight.netconf.nettyutil.handler.ssh.authentication.AuthenticationHandler;
+import org.opendaylight.netconf.shaded.sshd.client.channel.ChannelSubsystem;
 import org.opendaylight.netconf.shaded.sshd.client.channel.ClientChannel;
 import org.opendaylight.netconf.shaded.sshd.client.future.AuthFuture;
 import org.opendaylight.netconf.shaded.sshd.client.future.ConnectFuture;
+import org.opendaylight.netconf.shaded.sshd.client.future.OpenFuture;
 import org.opendaylight.netconf.shaded.sshd.client.session.ClientSession;
 import org.opendaylight.netconf.shaded.sshd.core.CoreModuleProperties;
 import org.slf4j.Logger;
@@ -32,8 +38,18 @@ import org.slf4j.LoggerFactory;
 /**
  * Netty SSH handler class. Acts as interface between Netty and SSH library.
  */
-public class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
+@Deprecated(since = "7.0.0", forRemoval = true)
+public final class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
     private static final Logger LOG = LoggerFactory.getLogger(AsyncSshHandler.class);
+    private static final VarHandle DISCONNECTED;
+
+    static {
+        try {
+            DISCONNECTED = MethodHandles.lookup().findVarHandle(AsyncSshHandler.class, "disconnected", boolean.class);
+        } catch (NoSuchFieldException | IllegalAccessException e) {
+            throw new ExceptionInInitializerError(e);
+        }
+    }
 
     public static final String SUBSYSTEM = "netconf";
 
@@ -42,12 +58,13 @@ public class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
     public static final NetconfSshClient DEFAULT_CLIENT;
 
     static {
-        final NetconfSshClient c = new NetconfClientBuilder().build();
+        final var c = new NetconfClientBuilder().build();
         // Disable default timeouts from mina sshd
-        c.getProperties().put(CoreModuleProperties.AUTH_TIMEOUT.getName(), "0");
-        c.getProperties().put(CoreModuleProperties.IDLE_TIMEOUT.getName(), "0");
-        c.getProperties().put(CoreModuleProperties.NIO2_READ_TIMEOUT.getName(), "0");
-        c.getProperties().put(CoreModuleProperties.TCP_NODELAY.getName(), true);
+        final var zero = Duration.ofMillis(0);
+        CoreModuleProperties.AUTH_TIMEOUT.set(c, zero);
+        CoreModuleProperties.IDLE_TIMEOUT.set(c, zero);
+        CoreModuleProperties.NIO2_READ_TIMEOUT.set(c, zero);
+        CoreModuleProperties.TCP_NODELAY.set(c, true);
 
         // TODO make configurable, or somehow reuse netty threadpool
         c.setNioWorkers(SSH_DEFAULT_NIO_WORKERS);
@@ -55,23 +72,33 @@ public class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
         DEFAULT_CLIENT = c;
     }
 
-    private final AtomicBoolean isDisconnected = new AtomicBoolean();
     private final AuthenticationHandler authenticationHandler;
     private final Future<?> negotiationFuture;
     private final NetconfSshClient sshClient;
+    private final String name;
 
-    private AsyncSshHandlerWriter sshWriteAsyncHandler;
+    // Initialized by connect()
+    @GuardedBy("this")
+    private ChannelPromise connectPromise;
 
-    private NettyAwareChannelSubsystem channel;
+    private AsyncSshHandlerWriter sshWriteAsyncHandler;
+    private ChannelSubsystem channel;
     private ClientSession session;
-    private ChannelPromise connectPromise;
     private FutureListener<Object> negotiationFutureListener;
 
-    public AsyncSshHandler(final AuthenticationHandler authenticationHandler, final NetconfSshClient sshClient,
-            final Future<?> negotiationFuture) {
+    private volatile boolean disconnected;
+
+    private AsyncSshHandler(final AuthenticationHandler authenticationHandler, final NetconfSshClient sshClient,
+            final @Nullable Future<?> negotiationFuture, final @Nullable String name) {
         this.authenticationHandler = requireNonNull(authenticationHandler);
         this.sshClient = requireNonNull(sshClient);
         this.negotiationFuture = negotiationFuture;
+        this.name = name != null && !name.isBlank() ? name : "UNNAMED";
+    }
+
+    public AsyncSshHandler(final AuthenticationHandler authenticationHandler, final NetconfSshClient sshClient,
+            final @Nullable Future<?> negotiationFuture) {
+        this(authenticationHandler, sshClient, negotiationFuture, null);
     }
 
     /**
@@ -97,52 +124,10 @@ public class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
      * @return                      {@code AsyncSshHandler}
      */
     public static AsyncSshHandler createForNetconfSubsystem(final AuthenticationHandler authenticationHandler,
-            final Future<?> negotiationFuture, final @Nullable NetconfSshClient sshClient) {
+            final Future<?> negotiationFuture, final @Nullable NetconfSshClient sshClient,
+            final @Nullable String name) {
         return new AsyncSshHandler(authenticationHandler, sshClient != null ? sshClient : DEFAULT_CLIENT,
-                negotiationFuture);
-    }
-
-    private synchronized void handleSshAuthenticated(final NettyAwareClientSession newSession,
-            final ChannelHandlerContext ctx) {
-        LOG.debug("SSH session authenticated on channel: {}, server version: {}", ctx.channel(),
-            newSession.getServerVersion());
-
-        try {
-            channel = newSession.createSubsystemChannel(SUBSYSTEM, ctx);
-            channel.setStreaming(ClientChannel.Streaming.Async);
-            channel.open().addListener(future -> {
-                if (future.isOpened()) {
-                    handleSshChanelOpened(ctx);
-                } else {
-                    handleSshSetupFailure(ctx, future.getException());
-                }
-            });
-        } catch (final IOException e) {
-            handleSshSetupFailure(ctx, e);
-        }
-    }
-
-    private synchronized void handleSshChanelOpened(final ChannelHandlerContext ctx) {
-        LOG.trace("SSH subsystem channel opened successfully on channel: {}", ctx.channel());
-
-        if (negotiationFuture == null) {
-            connectPromise.setSuccess();
-        }
-
-        sshWriteAsyncHandler = new AsyncSshHandlerWriter(channel.getAsyncIn());
-        ctx.fireChannelActive();
-        channel.onClose(() -> disconnect(ctx, ctx.newPromise()));
-    }
-
-    private synchronized void handleSshSetupFailure(final ChannelHandlerContext ctx, final Throwable error) {
-        LOG.warn("Unable to setup SSH connection on channel: {}", ctx.channel(), error);
-
-        // If the promise is not yet done, we have failed with initial connect and set connectPromise to failure
-        if (!connectPromise.isDone()) {
-            connectPromise.setFailure(error);
-        }
-
-        disconnect(ctx, ctx.newPromise());
+                negotiationFuture, name);
     }
 
     @Override
@@ -153,7 +138,7 @@ public class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
     @Override
     public synchronized void connect(final ChannelHandlerContext ctx, final SocketAddress remoteAddress,
             final SocketAddress localAddress, final ChannelPromise promise) throws IOException {
-        LOG.debug("SSH session connecting on channel {}. promise: {}", ctx.channel(), promise);
+        LOG.debug("{}: SSH session connecting on channel {}. promise: {}", name, ctx.channel(), promise);
         connectPromise = requireNonNull(promise);
 
         if (negotiationFuture != null) {
@@ -166,7 +151,7 @@ public class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
             negotiationFuture.addListener(negotiationFutureListener);
         }
 
-        LOG.debug("Starting SSH to {} on channel: {}", remoteAddress, ctx.channel());
+        LOG.debug("{}: Starting SSH to {} on channel: {}", name, remoteAddress, ctx.channel());
         sshClient.connect(authenticationHandler.getUsername(), remoteAddress)
             // FIXME: this is a blocking call, we should handle this with a concurrently-scheduled timeout. We do not
             //        have a Timer ready, so perhaps we should be using the event loop?
@@ -174,43 +159,93 @@ public class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
             .addListener(future -> onConnectComplete(future, ctx));
     }
 
-    private void onConnectComplete(final ConnectFuture future, final ChannelHandlerContext ctx) {
-        final var cause = future.getException();
+    private synchronized void onConnectComplete(final ConnectFuture connectFuture, final ChannelHandlerContext ctx) {
+        final var cause = connectFuture.getException();
         if (cause != null) {
-            handleSshSetupFailure(ctx, cause);
+            onOpenFailure(ctx, cause);
             return;
         }
 
-        final var clientSession = future.getSession();
-        LOG.trace("SSH session {} created on channel: {}", clientSession, ctx.channel());
+        final var clientSession = connectFuture.getSession();
+        LOG.trace("{}: SSH session {} created on channel: {}", name, clientSession, ctx.channel());
         verify(clientSession instanceof NettyAwareClientSession, "Unexpected session %s", clientSession);
-        onConnectComplete((NettyAwareClientSession) clientSession, ctx);
-    }
 
-    private synchronized void onConnectComplete(final NettyAwareClientSession clientSession,
-            final ChannelHandlerContext ctx) {
-        session = clientSession;
+        final var localSession = (NettyAwareClientSession) clientSession;
+        session = localSession;
 
         final AuthFuture authFuture;
         try {
-            authFuture = authenticationHandler.authenticate(clientSession);
+            authFuture = authenticationHandler.authenticate(localSession);
         } catch (final IOException e) {
-            handleSshSetupFailure(ctx, e);
+            onOpenFailure(ctx, e);
             return;
         }
 
-        authFuture.addListener(future -> onAuthComplete(future, clientSession, ctx));
+        authFuture.addListener(future -> onAuthComplete(future, localSession, ctx));
     }
 
-    private void onAuthComplete(final AuthFuture future, final NettyAwareClientSession clientSession,
+    private synchronized void onAuthComplete(final AuthFuture authFuture, final NettyAwareClientSession clientSession,
             final ChannelHandlerContext ctx) {
-        final var cause = future.getException();
+        final var cause = authFuture.getException();
+        if (cause != null) {
+            onOpenFailure(ctx, new AuthenticationFailedException("Authentication failed", cause));
+            return;
+        }
+        if (disconnected) {
+            LOG.debug("{}: Skipping SSH subsystem allocation, channel: {}", name, ctx.channel());
+            return;
+        }
+
+        LOG.debug("{}: SSH session authenticated on channel: {}, server version: {}", name, ctx.channel(),
+            clientSession.getServerVersion());
+
+        final OpenFuture openFuture;
+        try {
+            channel = clientSession.createSubsystemChannel(SUBSYSTEM, ctx);
+            channel.setStreaming(ClientChannel.Streaming.Async);
+            openFuture = channel.open();
+        } catch (final IOException e) {
+            onOpenFailure(ctx, e);
+            return;
+        }
+
+        openFuture.addListener(future -> ctx.executor().execute(() -> onOpenComplete(future, ctx)));
+    }
+
+    // This callback has to run on the channel's executor because it runs fireChannelActive(), which needs to be
+    // delivered synchronously. If we were to execute on some other thread we would end up delaying the event,
+    // potentially creating havoc in the pipeline.
+    private synchronized void onOpenComplete(final OpenFuture openFuture, final ChannelHandlerContext ctx) {
+        final var cause = openFuture.getException();
         if (cause != null) {
-            handleSshSetupFailure(ctx, new AuthenticationFailedException("Authentication failed", cause));
+            onOpenFailure(ctx, cause);
             return;
         }
+        if (disconnected) {
+            LOG.trace("{}: Skipping activation, channel: {}", name, ctx.channel());
+            return;
+        }
+
+        LOG.trace("{}: SSH subsystem channel opened successfully on channel: {}", name, ctx.channel());
+        if (negotiationFuture == null) {
+            connectPromise.setSuccess();
+        }
 
-        handleSshAuthenticated(clientSession, ctx);
+        sshWriteAsyncHandler = new AsyncSshHandlerWriter(channel.getAsyncIn());
+        ctx.fireChannelActive();
+        channel.onClose(() -> disconnect(ctx, ctx.newPromise()));
+    }
+
+    @Holding("this")
+    private void onOpenFailure(final ChannelHandlerContext ctx, final Throwable cause) {
+        LOG.warn("{}: Unable to setup SSH connection on channel: {}", name, ctx.channel(), cause);
+
+        // If the promise is not yet done, we have failed with initial connect and set connectPromise to failure
+        if (!connectPromise.isDone()) {
+            connectPromise.setFailure(cause);
+        }
+
+        disconnect(ctx, ctx.newPromise());
     }
 
     @Override
@@ -220,15 +255,18 @@ public class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
 
     @Override
     public void disconnect(final ChannelHandlerContext ctx, final ChannelPromise promise) {
-        if (isDisconnected.compareAndSet(false, true)) {
-            safelyDisconnect(ctx, promise);
+        if (DISCONNECTED.compareAndSet(this, false, true)) {
+            ctx.executor().execute(() -> safelyDisconnect(ctx, promise));
         }
     }
 
+    // This method has the potential to interact with the channel pipeline, for example via fireChannelInactive(). These
+    // callbacks need to complete during execution of this method and therefore this method needs to be executing on
+    // the channel's executor.
     @SuppressWarnings("checkstyle:IllegalCatch")
     private synchronized void safelyDisconnect(final ChannelHandlerContext ctx, final ChannelPromise promise) {
-        LOG.trace("Closing SSH session on channel: {} with connect promise in state: {}",
-                ctx.channel(), connectPromise);
+        LOG.trace("{}: Closing SSH session on channel: {} with connect promise in state: {}", name, ctx.channel(),
+            connectPromise);
 
         // If we have already succeeded and the session was dropped after,
         // we need to fire inactive to notify reconnect logic
@@ -272,16 +310,14 @@ public class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
             // Disconnect has to be closed after inactive channel event was fired, because it interferes with it
             super.disconnect(ctx, ctx.newPromise());
         } catch (final Exception e) {
-            LOG.warn("Unable to cleanup all resources for channel: {}. Ignoring.", ctx.channel(), e);
+            LOG.warn("{}: Unable to cleanup all resources for channel: {}. Ignoring.", name, ctx.channel(), e);
         }
 
         if (channel != null) {
-            //TODO: see if calling just close() is sufficient
-            //channel.close(false);
-            channel.close();
+            channel.close(false);
             channel = null;
         }
         promise.setSuccess();
-        LOG.debug("SSH session closed on channel: {}", ctx.channel());
+        LOG.debug("{}: SSH session closed on channel: {}", name, ctx.channel());
     }
 }