1 files changed, 67 insertions, 0 deletions
diff --git a/gerrit-sshd/src/main/java/com/google/gerrit/sshd/NoShell.java b/gerrit-sshd/src/main/java/com/google/gerrit/sshd/NoShell.java
new file mode 100644
index 0000000000..5cf9cb7681
--- /dev/null
+++ b/gerrit-sshd/src/main/java/com/google/gerrit/sshd/NoShell.java
@@ -0,0 +1,67 @@
+// Copyright (C) 2008 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.
+
+package com.google.gerrit.sshd;
+
+import org.apache.sshd.server.ShellFactory;
+import org.eclipse.jgit.lib.Constants;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+/**
+ * Dummy shell which prints a message and terminates.
+ * <p>
+ * This implementation is used to ensure clients who try to SSH directly to this
+ * server without supplying a command will get a reasonable error message, but
+ * cannot continue further.
+ */
+class NoShell implements ShellFactory {
+  public Shell createShell() {
+    return new Shell() {
+      private InputStream in;
+      private OutputStream out;
+      private OutputStream err;
+      private ExitCallback exit;
+
+      public void setInputStream(final InputStream in) {
+        this.in = in;
+      }
+
+      public void setOutputStream(final OutputStream out) {
+        this.out = out;
+      }
+
+      public void setErrorStream(final OutputStream err) {
+        this.err = err;
+      }
+
+      public void setExitCallback(final ExitCallback callback) {
+        this.exit = callback;
+      }
+
+      public void start(final Environment env) throws IOException {
+        err.write(Constants.encodeASCII("gerrit: no shell available\n"));
+        in.close();
+        out.close();
+        err.close();
+        exit.onExit(127);
+      }
+
+      public void destroy() {
+      }
+    };
+  }
+}