Add an extra parameter to the ssh tunnel

add the extra_args_ssh_tunnel args in the acloud.config
extra_args_ssh_tunnel: "-o ProxyCommand='ssh -W %h:%p firewall.example.org'"

The command will become to
ssh -o ProxyCommand='ssh -W %h:%p firewall.example.org' server2.example.org

Bug: 117625814
Test: atest acloud_test --host&
      acloud create (cloudtop)
      acloud reconnect (cloudtop)

Change-Id: I791568aa4829bb30567be38d6e08d75e37195f84
diff --git a/internal/lib/utils.py b/internal/lib/utils.py
index 5b085f4..ed9d343 100755
--- a/internal/lib/utils.py
+++ b/internal/lib/utils.py
@@ -25,6 +25,7 @@
 import logging
 import os
 import platform
+import shlex
 import shutil
 import signal
 import struct
@@ -830,7 +831,7 @@
 
 # pylint: disable=too-many-locals
 def AutoConnect(ip_addr, rsa_key_file, target_vnc_port, target_adb_port,
-                ssh_user, client_adb_port=None):
+                ssh_user, client_adb_port=None, extra_args_ssh_tunnel=None):
     """Autoconnect to an AVD instance.
 
     Args:
@@ -842,6 +843,7 @@
         target_adb_port: Integer of target adb port number.
         ssh_user: String of user login into the instance.
         client_adb_port: Integer, Specified adb port to establish connection.
+        extra_args_ssh_tunnel: String, extra args for ssh tunnel connection.
 
     Returns:
         NamedTuple of (vnc_port, adb_port) SSHTUNNEL of the connect, both are
@@ -858,10 +860,13 @@
             "target_adb_port": target_adb_port,
             "ssh_user": ssh_user,
             "ip_addr": ip_addr}
-        _ExecuteCommand(constants.SSH_BIN, ssh_tunnel_args.split())
-    except subprocess.CalledProcessError:
-        PrintColorString("Failed to create ssh tunnels, retry with '#acloud "
-                         "reconnect'.", TextColors.FAIL)
+        ssh_tunnel_args_list = shlex.split(ssh_tunnel_args)
+        if extra_args_ssh_tunnel:
+            ssh_tunnel_args_list.extend(shlex.split(extra_args_ssh_tunnel))
+        _ExecuteCommand(constants.SSH_BIN, ssh_tunnel_args_list)
+    except subprocess.CalledProcessError as e:
+        PrintColorString("\n%s\nFailed to create ssh tunnels, retry with '#acloud "
+                         "reconnect'." % e, TextColors.FAIL)
         return ForwardedPorts(vnc_port=None, adb_port=None)
 
     try:
diff --git a/internal/lib/utils_test.py b/internal/lib/utils_test.py
index 10d7a70..792ed8a 100644
--- a/internal/lib/utils_test.py
+++ b/internal/lib/utils_test.py
@@ -402,7 +402,7 @@
             self.fail("shouldn't timeout")
 
     def testAutoConnectCreateSSHTunnelFail(self):
-        """test auto connect."""
+        """Test auto connect."""
         fake_ip_addr = "1.1.1.1"
         fake_rsa_key_file = "/tmp/rsa_file"
         fake_target_vnc_port = 8888
@@ -418,6 +418,37 @@
                                                    target_adb_port,
                                                    ssh_user))
 
+    # pylint: disable=protected-access,no-member
+    def testExtraArgsSSHTunnel(self):
+        """Tesg extra args will be the same with expanded args."""
+        fake_ip_addr = "1.1.1.1"
+        fake_rsa_key_file = "/tmp/rsa_file"
+        fake_target_vnc_port = 8888
+        target_adb_port = 9999
+        ssh_user = "fake_user"
+        fake_port = 12345
+        self.Patch(utils, "PickFreePort", return_value=fake_port)
+        self.Patch(utils, "_ExecuteCommand")
+        self.Patch(subprocess, "check_call", return_value=True)
+        extra_args_ssh_tunnel = "-o command='shell %s %h' -o command1='ls -la'"
+        utils.AutoConnect(ip_addr=fake_ip_addr,
+                          rsa_key_file=fake_rsa_key_file,
+                          target_vnc_port=fake_target_vnc_port,
+                          target_adb_port=target_adb_port,
+                          ssh_user=ssh_user,
+                          client_adb_port=fake_port,
+                          extra_args_ssh_tunnel=extra_args_ssh_tunnel)
+        args_list = ["-i", "/tmp/rsa_file",
+                     "-o", "UserKnownHostsFile=/dev/null",
+                     "-o", "StrictHostKeyChecking=no",
+                     "-L", "12345:127.0.0.1:8888",
+                     "-L", "12345:127.0.0.1:9999",
+                     "-N", "-f", "-l", "fake_user", "1.1.1.1",
+                     "-o", "command=shell %s %h",
+                     "-o", "command1=ls -la"]
+        first_call_args = utils._ExecuteCommand.call_args_list[0][0]
+        self.assertEqual(first_call_args[1], args_list)
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/internal/proto/user_config.proto b/internal/proto/user_config.proto
index 131b42e..c3d618f 100755
--- a/internal/proto/user_config.proto
+++ b/internal/proto/user_config.proto
@@ -98,4 +98,7 @@
   // List of scopes that will be given to the instance
   // https://cloud.google.com/compute/docs/access/create-enable-service-accounts-for-instances#changeserviceaccountandscopes
   repeated string extra_scopes = 26;
+
+  // Provide some additional parameters to build the ssh tunnel.
+  optional string extra_args_ssh_tunnel = 27;
 }