validation code - wrong place?

ipv6ula/models.py

@@ -1,8 +1,9 @@
 from django.contrib.auth.models import AbstractUser
 from django.contrib.auth import get_user_model
 from django.db import models
+from django.core.exceptions import ValidationError
+
 
-import ipaddress
 
 
 class User(AbstractUser):
@@ -19,16 +20,12 @@ class ULA(models.Model):
     organization = models.CharField(max_length=256)
     website = models.URLField()
 
-    def save(self, *args, **kwargs):
-        """
-        Ensure we only save the first IPv6 address of the network
-        """
+    # def save(self, *args, **kwargs):
+    #     """
+    #     Ensure we only save the first IPv6 address of the network
+    #     """
 
-        net_str = f"{self.prefix}/48"
-        net = ipaddress.IPv6Network(net_str, strict=False)
-        self.prefix = str(net[0])
-
-        super().save(*args, **kwargs)
+    #     super().save(*args, **kwargs)
 
     def __str__(self):
         return f"{self.prefix}"

ipv6ula/views.py

@@ -6,6 +6,8 @@ from django.contrib.auth.mixins import LoginRequiredMixin
 from django.contrib.auth import logout
 from django.shortcuts import redirect
 
+import ipaddress
+
 from django.conf import settings
 
 from ipv6ula.models import *
@@ -23,6 +25,21 @@ class SubmitView(LoginRequiredMixin, CreateView):
 
     def form_valid(self, form):
         form.instance.owner = self.request.user
+
+        prefix = form.cleaned_data['prefix']
+
+        ula_net = ipaddress.IPv6Network("fd00::/8")
+        net_str = f"{prefix}/48"
+        net = ipaddress.IPv6Network(net_str, strict=False)
+
+        if not net.subnet_of(ula_net):
+            raise ValidationError(f"Prefix {prefix} is not within ULA range ({ula_net})",
+                                  code='invalid',
+                                  params = {'prefix': 42 }
+                                  )
+
+        self.prefix = str(net[0])
+
         return super(SubmitView, self).form_valid(form)
 
 class LoginView(auth_views.LoginView):