From ac81f741a0cea7dab494a56302df3f99c2bee1a2 Mon Sep 17 00:00:00 2001
From: Abhimanyu Saharan <desk.abhimanyu@gmail.com>
Date: Sat, 14 Jan 2023 14:31:50 +0530
Subject: [PATCH] added model validation for GenericForeignKey

---
 netbox/netbox/models/__init__.py | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/netbox/netbox/models/__init__.py b/netbox/netbox/models/__init__.py
index a4c8e0ec2..85f872136 100644
--- a/netbox/netbox/models/__init__.py
+++ b/netbox/netbox/models/__init__.py
@@ -1,4 +1,5 @@
 from django.conf import settings
+from django.contrib.contenttypes.fields import GenericForeignKey
 from django.core.validators import ValidationError
 from django.db import models
 from mptt.models import MPTTModel, TreeForeignKey
@@ -58,6 +59,23 @@ class NetBoxModel(CloningMixin, NetBoxFeatureSet, models.Model):
     class Meta:
         abstract = True
 
+    def clean(self):
+        """
+        Validate the model for GenericForeignKey fields to ensure that the content type and object ID exist.
+        """
+        super().clean()
+
+        for field in self._meta.get_fields():
+            if isinstance(field, GenericForeignKey):
+                if getattr(self, field.ct_field) and getattr(self, field.fk_field):
+                    klass = getattr(self, field.ct_field).model_class()
+                    try:
+                        klass.objects.get(pk=getattr(self, field.fk_field))
+                    except klass.DoesNotExist:
+                        raise ValidationError({
+                            field.fk_field: f"Invalid {getattr(self, field.fk_field)}: object does not exist on {getattr(self, field.ct_field)}."
+                        })
+
 
 class PrimaryModel(NetBoxModel):
     """