RelayNext: yet another crappy antiflood mechanism

Also, catch errors in outFilter so they don't block all of the bot's output.

RelayNext/config.py

@@ -61,6 +61,20 @@ conf.registerChannelValue(RelayNext, 'noHighlight',
     registry.Boolean(False, _("""Determines whether the bot should prefix nicks
     with a hyphen (-) to prevent excess highlights (in PRIVMSGs and actions).""")))
 
+conf.registerGroup(RelayNext, 'antiflood')
+conf.registerChannelValue(RelayNext.antiflood, 'enable',
+    registry.Boolean(False, _("""Determines whether flood prevention should be enabled
+    for the given channel.""")))
+conf.registerChannelValue(RelayNext.antiflood, 'seconds',
+    registry.PositiveInteger(20, _("""Determines how many seconds messages should be queued
+        for flood protection.""")))
+conf.registerChannelValue(RelayNext.antiflood, 'maximum',
+    registry.PositiveInteger(15, _("""Determines the maximum amount of incoming messages
+        the bot will allow from a relay channel before flood protection is triggered.""")))
+conf.registerChannelValue(RelayNext.antiflood, 'timeout',
+    registry.PositiveInteger(60, _("""Determines the amount of time in seconds the bot should
+        block messages if flood protection is triggered.""")))
+
 conf.registerGroup(RelayNext, 'events')
 
 _events = ('quit', 'join', 'part', 'nick', 'mode', 'kick')

RelayNext/plugin.py

@@ -31,6 +31,7 @@
 from copy import deepcopy
 import pickle
 import re
+import traceback
 
 import supybot.world as world
 import supybot.irclib as irclib
@@ -41,6 +42,7 @@ from supybot.commands import *
 import supybot.plugins as plugins
 import supybot.ircutils as ircutils
 import supybot.callbacks as callbacks
+from supybot.utils.structures import TimeoutQueue
 try:
     from supybot.i18n import PluginInternationalization
     _ = PluginInternationalization('RelayNext')
@@ -91,6 +93,10 @@ class RelayNext(callbacks.Plugin):
         self.ircstates = {}
         self.lastmsg = {}
 
+        # This part facilitates flood protection
+        self.msgcounters = {}
+        self.floodTriggered = False
+
         self.db = {}
         self.loadDB()
         world.flushers.append(self.exportDB)
@@ -144,7 +150,7 @@ class RelayNext(callbacks.Plugin):
                     results.append(cn[0])
         return results
 
-    def _format(self, irc, msg):
+    def _format(self, irc, msg, announcement=False):
         s = ''
         nick = msg.nick
         userhost = ''
@@ -166,7 +172,10 @@ class RelayNext(callbacks.Plugin):
                 userhost = ' (%s)' % msg.prefix.split('!', 1)[1]
             except:
                 pass
-
+        if announcement:
+            # Announcements use a special syntax
+            s = '*** %s' % announcement
+        else:
             if msg.command == 'NICK':
                 newnick = msg.args[0]
                 if color:
@@ -199,6 +208,12 @@ class RelayNext(callbacks.Plugin):
             s = s.replace("- -", "-", 1)
         return s
 
+    def checkFlood(self, channel, source, command):
+        maximum = self.registryValue("antiflood.maximum", channel)
+        enabled = self.registryValue("antiflood.enable", channel)
+        if enabled and len(self.msgcounters[(source, command)]) > maximum:
+            return True
+
     def relay(self, irc, msg, channel=None):
         channel = channel or msg.args[0]
         # Get the source channel
@@ -206,6 +221,29 @@ class RelayNext(callbacks.Plugin):
         source = source.lower()
         out_s = self._format(irc, msg)
         if out_s:
+            ### Begin Flood checking clause
+            timeout = self.registryValue("antiflood.timeout", channel)
+            seconds = self.registryValue("antiflood.seconds", channel)
+            maximum = self.registryValue("antiflood.maximum", channel)
+            try:
+                self.msgcounters[(source, msg.command)].enqueue(msg.prefix)
+            except KeyError:
+                self.msgcounters[(source, msg.command)] = TimeoutQueue(seconds)
+            if self.checkFlood(channel, source, msg.command):
+                self.log.debug("RelayNext (%s): message from %s blocked by "
+                               "flood preotection.", irc.network, channel)
+                if self.floodTriggered:
+                    return
+                c = msg.command.lower()
+                e = format("Flood detected on %s (%s %ss/%s seconds), "
+                           "not relaying %ss for %s seconds!", channel,
+                           maximum, c, seconds, c, timeout)
+                out_s = self._format(irc, msg, announcement=e)
+                self.log.info("RelayNext (%s): %s", irc.network, e)
+                self.floodTriggered = True
+            else:
+                self.floodTriggered = False
+            ### End Flood checking clause
             for relay in self.db.values():
                 if source in relay:  # If our channel is in a relay
                     # Remove ourselves so we don't get duplicated messages
@@ -255,11 +293,17 @@ class RelayNext(callbacks.Plugin):
     def outFilter(self, irc, msg):
         # Catch our own messages and send them into the relay (this is
         # useful because Supybot is often a multi-purpose bot!)
+        try:
             if msg.command == 'PRIVMSG' and not msg.relayedMsg:
                     if msg.args[0] in self._getAllRelaysForNetwork(irc):
                         new_msg = deepcopy(msg)
                         new_msg.nick = irc.nick
                         self.relay(irc, new_msg, channel=msg.args[0])
+        except Exception as e:
+            # We want to log errors, but not block the bot's output
+            traceback.print_exc()
+            log.error(str(e))
+        finally:
             return msg
 
     ### User commands