New Changehost plugin, with flexible on-connect vHost settings using hostmask matches and substitution

plugins/changehost.py

@@ -0,0 +1,67 @@
+"""
+Changehost plugin - automatically changes the hostname of matching users.
+"""
+
+# Import hacks to access utils and log.
+import sys
+import os
+sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+import string
+
+# ircmatch library from https://github.com/mammon-ircd/ircmatch
+# (pip install ircmatch)
+import ircmatch
+
+import utils
+import world
+from log import log
+
+# Characters allowed in a hostname.
+allowed_chars = string.ascii_letters + '-./:'
+
+def handle_uid(irc, sender, command, args):
+    """
+    Listener for new connections.
+    """
+
+    changehost_conf = irc.conf.get("changehost")
+
+    if not changehost_conf:
+        log.warning("(%s) Missing 'changehost:' configuration block; "
+                    "Changehost will not function correctly!", irc.name)
+        return
+    elif irc.name not in changehost_conf.get('enabled_nets'):
+        # We're not enabled on the network, break.
+        return
+
+    changehost_hosts = changehost_conf.get('hosts')
+    if not changehost_hosts:
+        log.warning("(%s) No hosts were defined in changehost::hosts; "
+                    "Changehost will not function correctly!", irc.name)
+        return
+
+    target = args['uid']
+
+    for host_glob, host_template in changehost_hosts.items():
+        if ircmatch.match(0, host_glob, utils.getHostmask(irc, target)):
+            # This uses template strings for simple substitution:
+            # https://docs.python.org/3/library/string.html#template-strings
+            template = string.Template(host_template)
+
+            # Substitute using the fields provided the hook data. This means
+            # that the following variables are available for substitution:
+            # $uid, $ts, $nick, $realhost, $host, $ident, $ip
+            new_host = template.substitute(args)
+
+            # Replace characters that are not allowed in hosts with "-".
+            for char in new_host:
+                if char not in allowed_chars:
+                    new_host = new_host.replace(char, '-')
+
+            irc.proto.updateClient(target, 'HOST', new_host)
+
+            # Only operate on the first match.
+            break
+
+utils.add_hook(handle_uid, 'UID')