recursive/embedded version of issue/907;

test cases merged from remote-tracking branch 'yarikoptic:enh/embedded_tags' into issue/907
infinite busy loop on _escapedTags match in substituteRecursiveTags gh-907

ChangeLog

@@ -30,6 +30,9 @@ ver. 0.9.2 (2014/XX/XXX) - wanna-be-released
 - New Features:
    - New filter:
      - postfix-rbl  Thanks Lee Clemens
+   - New recursive embedded substitution feature added:
+     - `<<PREF>HOST>` becomes `<IPV4HOST>` for PREF=`IPV4`;
+     - `<<PREF>HOST>` becomes `1.2.3.4` for PREF=`IPV4` and IPV4HOST=`1.2.3.4`;
    - New interpolation feature for config readers - `%(known/parameter)s`.
      (means last known option with name `parameter`). This interpolation makes
      possible to extend a stock filter or jail regexp in .local file

fail2ban/server/action.py

@@ -378,7 +378,9 @@ class CommandAction(ActionBase):
 			Dictionary of tags(keys) and their values, with tags
 			within the values recursively replaced.
 		"""
-		t = re.compile(r'<([^ >]+)>')
+		t = re.compile(r'<([^ <>]+)>')
+		while True:
+			repFlag = False
 			for tag in tags.iterkeys():
 				if tag in cls._escapedTags:
 					# Escaped so won't match
@@ -405,7 +407,12 @@ class CommandAction(ActionBase):
 					done.append(found_tag)
 					m = t.search(value, m.start())
 				#logSys.log(5, 'TAG: %s, newvalue: %s' % (tag, value))
+				# if was substituted, check again later:
+				if tags[tag] != value:
+					repFlag = True
 					tags[tag] = value
+			if not repFlag:
+				break
 		return tags
 
 	@staticmethod

fail2ban/tests/actiontestcase.py

@@ -73,6 +73,11 @@ class CommandActionTest(LogCaptureTestCase):
 									'ABC': '123 192.0.2.0',
 									'xyz': '890 123 192.0.2.0',
 								})
+		# obscure embedded case
+		self.assertEqual(CommandAction.substituteRecursiveTags({'A': '<<PREF>HOST>', 'PREF': 'IPV4'}),
+						 {'A': '<IPV4HOST>', 'PREF': 'IPV4'})
+		self.assertEqual(CommandAction.substituteRecursiveTags({'A': '<<PREF>HOST>', 'PREF': 'IPV4', 'IPV4HOST': '1.2.3.4'}),
+						 {'A': '1.2.3.4', 'PREF': 'IPV4', 'IPV4HOST': '1.2.3.4'})
 
 	def testReplaceTag(self):
 		aInfo = {