New servprotect plugin (anti-KILL/SAVE flood)

README.md

@@ -16,7 +16,7 @@ You can also find support via our IRC channels: `#PyLink @ irc.overdrivenetworks
 
 * Python 3.4+
 * PyYAML (`pip install pyyaml`)
-* *For the relay plugin*: expiringdict (`pip install expiringdict`)
+* *For the servprotect plugin*: python3-expiringdict (`apt-get install python3-expiringdict`; not available in pip)
 * *For the changehost and opercmds plugins*: ircmatch (`pip install ircmatch`)
 
 ### Supported IRCds

plugins/servprotect.py

@@ -0,0 +1,41 @@
+# servprotect.py: Protects against KILL and nick collision floods
+import sys
+import os
+sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from expiringdict import ExpiringDict
+
+import utils
+from log import log
+
+# TODO: make length and time configurable
+savecache = ExpiringDict(max_len=5, max_age_seconds=10)
+killcache = ExpiringDict(max_len=5, max_age_seconds=10)
+
+def handle_kill(irc, numeric, command, args):
+    """
+    Tracks kills against PyLink clients. If too many are received,
+    automatically disconnects from the network.
+    """
+    if killcache.setdefault(irc.name, 1) >= 5:
+        log.error('(%s) servprotect: Too many kills received, aborting!', irc.name)
+        irc.disconnect()
+
+    log.debug('(%s) servprotect: Incrementing killcache by 1', irc.name)
+    killcache[irc.name] += 1
+
+utils.add_hook(handle_kill, 'KILL')
+
+def handle_save(irc, numeric, command, args):
+    """
+    Tracks SAVEs (nick collision) against PyLink clients. If too many are received,
+    automatically disconnects from the network.
+    """
+    if savecache.setdefault(irc.name, 0) >= 5:
+        log.error('(%s) servprotect: Too many nick collisions, aborting!', irc.name)
+        irc.disconnect()
+
+    log.debug('(%s) servprotect: Incrementing savecache by 1', irc.name)
+    savecache[irc.name] += 1
+
+utils.add_hook(handle_save, 'SAVE')