From f6a6eeca08f491e32a1127394082560d4be86c27 Mon Sep 17 00:00:00 2001
From: Thomas Waldmann <tw@waldmann-edv.de>
Date: Mon, 8 Nov 2021 22:57:52 +0100
Subject: [PATCH] try to identify&remove illegal/abusive users

---
 src/nsupdate/management/commands/illegal.py | 57 +++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 src/nsupdate/management/commands/illegal.py

diff --git a/src/nsupdate/management/commands/illegal.py b/src/nsupdate/management/commands/illegal.py
new file mode 100644
index 0000000..cb767f0
--- /dev/null
+++ b/src/nsupdate/management/commands/illegal.py
@@ -0,0 +1,57 @@
+"""
+try to identify users / hosts doing illegal / questionable things
+"""
+
+import time
+from collections import defaultdict
+
+from django.core.management.base import BaseCommand
+from django.db import transaction
+from django.db.utils import OperationalError
+
+from nsupdate.main.models import Host
+from nsupdate.main import dnstools
+
+
+class Command(BaseCommand):
+    help = 'try to identify users / hosts doing illegal / questionable things'
+
+    def handle(self, *args, **options):
+        ip_to_hosts = defaultdict(list)
+        for host in Host.objects.all():
+            fqdn = host.get_fqdn()
+            try:
+                ip = dnstools.query_ns(fqdn, 'A')
+                ip_to_hosts[ip].append(host)
+            except:
+                pass
+        ips = sorted(ip_to_hosts.keys(), key=lambda ip: len(ip_to_hosts[ip]), reverse=True)
+        for ip in ips:
+            users = {}
+            hosts_of_user = defaultdict(list)
+            hosts = ip_to_hosts[ip]
+            ip_refcount = len(hosts)
+            print("IP %s is referred to by %d hosts." % (ip, ip_refcount))
+            for host in hosts:
+                user = host.created_by
+                users[user.id] = user
+                hosts_of_user[user.id].append(host)
+            response = None
+            for user_id in users:
+                user = users[user_id]
+                count = len(hosts_of_user[user_id])
+                hostname_samples = ', '.join(h.name for h in hosts_of_user[user_id][:10])
+                print("User %s (%s) has created %d hosts all pointing to same IP as %d other hostnames." % (user.username, user.email, count, ip_refcount - count))
+                print("Hostname samples: %s" % (hostname_samples, ))
+                if response != 'Y':
+                    response = input("Delete user? no [default], y = yes, Y = YES to all, a = abort > ")
+                if response.lower() == 'y':
+                    while True:
+                        try:
+                            user.delete()
+                            break
+                        except OperationalError:
+                            # database is locked
+                            time.sleep(0.1)
+                if response.lower() == 'a':
+                    break