core: add extban support in matchHost, and $account matching (#170)

The following forms are supported in $account, with groups separated by a
literal colon. All account and network name matching is currently case sensitive:

$account -> Returns True (a match) if the target is registered.
$account:accountname -> Returns True if the target's account name matches the one given, and the target is connected to the local network..
$account:accountname:netname -> Returns True if both the target's account name and origin network name match the ones given.
$account:*:netname -> Matches all logged in users on the given network.

classes.py

@@ -920,8 +920,28 @@ class Irc():
         # Get the corresponding casemapping value used by ircmatch.
         casemapping = getattr(ircmatch, self.proto.casemapping)
 
+        # Try to convert target into a UID. If this fails, it's probably a hostname.
+        target = self.nickToUid(target) or target
+
         # Prepare a list of hosts to check against.
         if target in self.users:
+            if glob.startswith('$'):
+                # Exttargets start with $. Skip regular ban matching and find the matching ban handler.
+                glob = glob.lstrip('$')
+                exttargetname = glob.split(':', 1)[0]
+                handler = world.exttarget_handlers.get(exttargetname)
+
+                if handler:
+                    # Handler exists. Return what it finds.
+                    result = handler(self, glob, target)
+                    log.debug('(%s) Got %s from exttarget %s in matchHost() glob $%s for target %s',
+                              self.name, result, exttargetname, glob, target)
+                    return result
+                else:
+                    log.debug('(%s) Unknown exttarget %s in matchHost() glob $%s', self.name,
+                              exttargetname, glob)
+                    return False
+
             hosts = {self.getHostmask(target)}
 
             if ip:

coremods/__init__.py

@@ -1,2 +1,2 @@
 # Service support has to be imported first, so that utils.add_cmd works
-from . import service_support, control, handlers, corecommands
+from . import service_support, control, handlers, corecommands, exttargets

coremods/exttargets.py

@@ -0,0 +1,57 @@
+"""
+exttargets.py - Implements extended targets like $account:xyz, $oper, etc.
+"""
+
+from pylinkirc import world
+from pylinkirc.log import log
+
+def bind(func):
+    """
+    Binds an exttarget with the given name.
+    """
+    world.exttarget_handlers[func.__name__] = func
+    return func
+
+@bind
+def account(irc, host, uid):
+    """
+    $account exttarget handler. The following forms are supported, with groups separated by a
+    literal colon. All account and network name matching is currently case sensitive:
+
+    $account -> Returns True (a match) if the target is registered.
+    $account:accountname -> Returns True if the target's account name matches the one given, and the
+    target is connected to the local network..
+    $account:accountname:netname -> Returns True if both the target's account name and origin
+    network name match the ones given.
+    $account:*:netname -> Matches all logged in users on the given network.
+    """
+    userobj = irc.users[uid]
+    homenet = irc.name
+    if hasattr(userobj, 'remote'):
+        # User is a PyLink Relay pseudoclient. Use their real services account on their
+        # origin network.
+        homenet, realuid = userobj.remote
+        log.debug('(%s) exttargets.account: Changing UID of relay client %s to %s/%s', irc.name,
+                  uid, homenet, realuid)
+        try:
+            userobj = world.networkobjects[homenet].users[realuid]
+        except KeyError:  # User lookup failed. Bail and return False.
+            log.exception('(%s) exttargets.account: KeyError finding %s/%s:', irc.name,
+                          homenet, realuid)
+            return False
+
+    slogin = userobj.services_account
+
+    # Split the given exttarget host into parts, so we know how many to look for.
+    groups = host.split(':')
+    log.debug('(%s) exttargets.account: groups to match: %s', irc.name, groups)
+
+    if len(groups) == 1:
+        # First scenario. Return True if user is logged in.
+        return bool(slogin)
+    elif len(groups) == 2:
+        # Second scenario. Return True if the user's account matches the one given.
+        return slogin == groups[1] and homenet == irc.name
+    else:
+        # Third or fourth scenario. If there are more than 3 groups, the rest are ignored.
+        return (groups[1] in ('*', slogin)) and (homenet == groups[2])

world.py

@@ -16,6 +16,9 @@ networkobjects = {}
 plugins = {}
 services = {}
 
+# Registered extarget handlers. This maps exttarget names (strings) to handling functions.
+exttarget_handlers = {}
+
 started = threading.Event()
 
 source = "https://github.com/GLolol/PyLink"  # CHANGE THIS IF YOU'RE FORKING!!