mac80211: add rx decapsulation offload support

This allows drivers to pass 802.3 frames to mac80211, with some restrictions:

- the skb must be passed with a valid sta
- fast-rx needs to be active for the sta
- monitor mode needs to be disabled

mac80211 will tell the driver when it is safe to enable rx decap offload for
a particular station.

In order to implement support, a driver must:

- call ieee80211_hw_set(hw, SUPPORTS_RX_DECAP_OFFLOAD)
- implement ops->sta_set_decap_offload
- mark 802.3 frames with RX_FLAG_8023

If it doesn't want to enable offload for some vif types, it can mask out
IEEE80211_OFFLOAD_DECAP_ENABLED in vif->offload_flags from within the
.add_interface or .update_vif_offload driver ops

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20201218184718.93650-6-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index bcdfd19a596b..604ca59937f0 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -1413,4 +1413,20 @@ static inline void drv_sta_set_4addr(struct ieee80211_local *local,
 	trace_drv_return_void(local);
 }
 
+static inline void drv_sta_set_decap_offload(struct ieee80211_local *local,
+					     struct ieee80211_sub_if_data *sdata,
+					     struct ieee80211_sta *sta,
+					     bool enabled)
+{
+	sdata = get_bss_sdata(sdata);
+	if (!check_sdata_in_driver(sdata))
+		return;
+
+	trace_drv_sta_set_decap_offload(local, sdata, sta, enabled);
+	if (local->ops->sta_set_decap_offload)
+		local->ops->sta_set_decap_offload(&local->hw, &sdata->vif, sta,
+						  enabled);
+	trace_drv_return_void(local);
+}
+
 #endif /* __MAC80211_DRIVER_OPS */