views: add auxiliar function is_valid_ip()

Move ip validation logic to a separate function to make the code
more expressive and reusable.

ogcp/views.py

@@ -116,6 +116,13 @@ def prettify_mac(mac):
         return mac
     return (':'.join(normalized_mac[i:i+2] for i in range(0, 12, 2))).lower()
 
+def is_valid_ip(ip):
+    try:
+        ipaddress.ip_address(ip)
+    except:
+        return False
+    return True
+
 def ogserver_down(view):
     flash(_('Cannot talk to ogserver. Is ogserver down?'), category='error')
     return redirect(url_for(view))
@@ -1310,9 +1317,7 @@ def action_client_update():
     form = ClientDetailsForm(request.form)
     if request.method == 'POST':
 
-        try:
-            ipaddress.ip_address(form.ip.data)
-        except ValueError as e:
+        if not is_valid_ip(form.ip.data):
             flash(_('Invalid IP address'), category='error')
             return redirect(url_for("scopes"))
 
@@ -1573,9 +1578,7 @@ def action_client_add():
             flash(_('Invalid empty client name'), category='error')
             return redirect(url_for("scopes"))
 
-        try:
-            ipaddress.ip_address(form.ip.data)
-        except ValueError as e:
+        if not is_valid_ip(form.ip.data):
             flash(_('Invalid IP address'), category='error')
             return redirect(url_for("scopes"))
 
@@ -1791,9 +1794,7 @@ def action_clients_import_post():
 
         client_ip = client_values[2]
 
-        try:
-            ipaddress.ip_address(client_ip)
-        except ValueError as e:
+        if not is_valid_ip(client_ip):
             flash(_(f'Invalid IP address {client_ip}'), category='error')
             return redirect(url_for("scopes"))