Validate exploit's setup before `run` and `check` commands (#367)

Introduce `Exploit.validate_setup` method in order to check whether
Exploit's setup is correct. In most case scanarios we will check
if `Exploit.target` is not `None`. When exploit need custom
validation logic please overwrite `validate_setup`.

routersploit/exploits.py

@@ -4,6 +4,7 @@ import time
 from itertools import chain
 from weakref import WeakKeyDictionary
 
+from routersploit.exceptions import OptionValidationError
 from routersploit.utils import print_status, NonStringIterable
 
 GLOBAL_OPTS = {}
@@ -133,3 +134,12 @@ class Exploit(BaseExploit):
         for worker in workers:
             worker.join()
         print_status('Elapsed time: ', time.time() - start, 'seconds')
+
+    def validate_setup(self):
+        """ Validate exploit's setup before `run()`
+
+        If exploit need extra validation make sure to overwrite this with
+        custom validation logic.
+        """
+        if not self.target:
+            raise OptionValidationError("Please set target address.")

routersploit/interpreter.py

@@ -6,7 +6,10 @@ import traceback
 from collections import Counter
 
 from routersploit import utils
-from routersploit.exceptions import RoutersploitException
+from routersploit.exceptions import (
+    RoutersploitException,
+    OptionValidationError,
+)
 from routersploit.exploits import Exploit, GLOBAL_OPTS
 from routersploit.payloads import BasePayload
 from routersploit.printer import PrinterThread, printer_queue
@@ -328,12 +331,15 @@ class RoutersploitInterpreter(BaseInterpreter):
 
     @utils.module_required
     def command_run(self, *args, **kwargs):
-        utils.print_status("Running module...")
         try:
+            self.current_module.validate_setup()
+            utils.print_status("Running module...")
             self.current_module.run()
         except KeyboardInterrupt:
             utils.print_info()
             utils.print_error("Operation cancelled by user")
+        except OptionValidationError as err:
+            utils.print_error(err)
         except Exception:
             utils.print_error(traceback.format_exc(sys.exc_info()))
 
@@ -477,6 +483,7 @@ class RoutersploitInterpreter(BaseInterpreter):
     @utils.module_required
     def command_check(self, *args, **kwargs):
         try:
+            self.current_module.validate_setup()
             result = self.current_module.check()
         except Exception as error:
             utils.print_error(error)

tests/test_exploits.py

@@ -3,6 +3,7 @@ import unittest
 
 import mock
 
+from routersploit.exceptions import OptionValidationError
 from routersploit.exploits import Exploit, GLOBAL_OPTS, Option
 from tests.test_case import RoutersploitTestCase
 
@@ -95,6 +96,11 @@ class OptionTest(RoutersploitTestCase):
         self.assertEqual(self.exploit_bar.options, ['paa', 'target', 'doo'])
         self.assertEqual(self.exploit_foo.options, ['paa', 'target', 'doo'])
 
+    def test_validate_setup(self):
+        with self.assertRaises(OptionValidationError):
+            self.exploit_bar.target = ""
+            self.exploit_bar.validate_setup()
+
 
 if __name__ == '__main__':
     unittest.main()

tests/test_interpreter.py

@@ -154,56 +154,77 @@ class RoutersploitInterpreterTest(RoutersploitTestCase):
 
     @mock.patch('routersploit.utils.print_status')
     def test_command_run(self, mock_print_status):
-        with mock.patch.object(self.interpreter.current_module,
-                               'run') as mock_run:
+        mock_run = mock.Mock()
+        mock_validate_setup = mock.Mock()
+        self.interpreter.current_module.run = mock_run
+        self.interpreter.current_module.validate_setup = mock_validate_setup
+
         self.interpreter.command_run()
+        mock_validate_setup.assert_called_once()
         mock_run.assert_called_once_with()
         mock_print_status.assert_called_once_with('Running module...')
 
     @mock.patch('routersploit.utils.print_success')
     def test_command_check_target_vulnerable(self, mock_print_success):
-        with mock.patch.object(self.interpreter.current_module,
-                               'check') as mock_check:
+        mock_check = mock.Mock()
+        mock_validate_setup = mock.Mock()
+        self.interpreter.current_module.check = mock_check
+        self.interpreter.current_module.validate_setup = mock_validate_setup
         mock_check.return_value = True
+
         self.interpreter.command_check()
+        mock_validate_setup.assert_called_once()
         mock_check.assert_called_once_with()
         mock_print_success.assert_called_once_with('Target is vulnerable')
 
     @mock.patch('routersploit.utils.print_error')
     def test_command_check_target_not_vulnerable(self, print_error):
-        with mock.patch.object(self.interpreter.current_module,
-                               'check') as mock_check:
+        mock_check = mock.Mock()
+        mock_validate_setup = mock.Mock()
+        self.interpreter.current_module.check = mock_check
+        self.interpreter.current_module.validate_setup = mock_validate_setup
         mock_check.return_value = False
+
         self.interpreter.command_check()
+        mock_validate_setup.assert_called_once()
         mock_check.assert_called_once_with()
         print_error.assert_called_once_with('Target is not vulnerable')
 
     @mock.patch('routersploit.utils.print_status')
     def test_command_check_target_could_not_be_verified_1(self, print_status):
-        with mock.patch.object(self.interpreter.current_module,
-                               'check') as mock_check:
+        mock_check = mock.Mock()
+        mock_validate_setup = mock.Mock()
+        self.interpreter.current_module.check = mock_check
+        self.interpreter.current_module.validate_setup = mock_validate_setup
         mock_check.return_value = "something"
+
         self.interpreter.command_check()
+        mock_validate_setup.assert_called_once()
         mock_check.assert_called_once_with()
-            print_status.assert_called_once_with(
-                'Target could not be verified')
+        print_status.assert_called_once_with('Target could not be verified')
 
     @mock.patch('routersploit.utils.print_status')
     def test_command_check_target_could_not_be_verified_2(self, print_status):
-        with mock.patch.object(self.interpreter.current_module,
-                               'check') as mock_check:
+        mock_check = mock.Mock()
+        mock_validate_setup = mock.Mock()
+        self.interpreter.current_module.check = mock_check
+        self.interpreter.current_module.validate_setup = mock_validate_setup
         mock_check.return_value = None
+
         self.interpreter.command_check()
+        mock_validate_setup.assert_called_once()
         mock_check.assert_called_once_with()
-            print_status.assert_called_once_with(
-                'Target could not be verified')
+        print_status.assert_called_once_with('Target could not be verified')
 
     @mock.patch('routersploit.utils.print_error')
     def test_command_check_not_supported_by_module(self, print_error):
-        with mock.patch.object(self.interpreter.current_module,
-                               'check') as mock_check:
+        mock_check = mock.Mock()
+        mock_validate_setup = mock.Mock()
+        self.interpreter.current_module.check = mock_check
+        self.interpreter.current_module.validate_setup = mock_validate_setup
         exception = NotImplementedError("Not available")
         mock_check.side_effect = exception
+
         self.interpreter.command_check()
         mock_check.assert_called_once_with()
         print_error.assert_called_once_with(exception)