TLS device features
-------------------
-Drivers should ignore the changes to TLS the device feature flags.
+Drivers should ignore the changes to the TLS device feature flags.
These flags will be acted upon accordingly by the core ``ktls`` code.
TLS device feature flags only control adding of new TLS connection
offloads, old connections will remain active after flags are cleared.
+
+TLS encryption cannot be offloaded to devices without checksum calculation
+offload. Hence, TLS TX device feature flag requires NETIF_F_HW_CSUM being set.
+Disabling the latter implies clearing the former. Disabling TX checksum offload
+should not affect old connections, and drivers should make sure checksum
+calculation does not break for them.
}
}
+ if ((features & NETIF_F_HW_TLS_TX) && !(features & NETIF_F_HW_CSUM)) {
+ netdev_dbg(dev, "Dropping TLS TX HW offload feature since no CSUM feature.\n");
+ features &= ~NETIF_F_HW_TLS_TX;
+ }
+
return features;
}