Create validator_asn.py

src/django-lan/utils/validators/validator_asn.py

@@ -0,0 +1,91 @@
+# -*- coding: utf-8 -*-
+
+
+# =============================================================================
+# Docstring
+# =============================================================================
+
+"""
+Provides ASN Validation Function
+================================
+
+Validates Autonomous System Numbers (ASNs) which are critical for routing
+decisions on the internet.
+
+Links:
+- https://en.wikipedia.org/wiki/Autonomous_system_(Internet)
+
+"""
+
+
+# =============================================================================
+# Import
+# =============================================================================
+
+# Import | Standard Library
+from typing import Any
+
+# Import | Libraries
+from django.core.exceptions import ValidationError
+from django.utils.translation import gettext_lazy as _
+
+# Import | Local Modules
+
+
+# =============================================================================
+# Variables
+# =============================================================================
+
+
+# =============================================================================
+# Functions
+# =============================================================================
+
+
+def validate_asn(value: Any) -> None:
+    """
+    ASN Validation Function
+    =======================
+
+    Validates that the provided value is a valid Autonomous System Number
+    (ASN).
+
+    An ASN is a special number assigned by IANA to each autonomous system
+    which uses BGP routing. This function checks if the provided ASN is
+    within the  valid range of 1 to 4294967295, inclusive.
+
+    Args:
+        value (Any): The ASN to validate. While typically an integer, this
+            accepts `Any` to gracefully handle unexpected input types.
+
+    Raises:
+        ValidationError: If the ASN is not within the valid range.
+
+    Examples:
+        >>> validate_asn(64512)
+        None
+        >>> validate_asn(4294967296)
+        ValidationError: ASN must be between 1 and 4294967295 (inclusive).
+
+    """
+
+    try:
+        asn = int(value)
+    except ValueError:
+        raise ValidationError(
+            _("ASN must be a number.")
+        )
+
+    if not (1 <= asn <= 4294967295):
+        raise ValidationError(
+            _("ASN must be between 1 and 4294967295 (inclusive).")
+        )
+
+
+# =============================================================================
+# Public Interface
+# =============================================================================
+
+__all__ = [
+    "validate_asn",
+]