> This allows drivers to provide a destination device + info for flow offload
> Only supported in combination with 802.3 encap offload
> 
> Signed-off-by: Felix Fietkau <nbd@nbd.name>
> ---
>  include/net/mac80211.h     |  7 +++++
>  net/mac80211/driver-ops.h  | 22 ++++++++++++++
>  net/mac80211/ieee80211_i.h |  2 +-
>  net/mac80211/iface.c       | 61 ++++++++++++++++++++++++++++++++++++++
>  net/mac80211/trace.h       |  7 +++++
>  5 files changed, 98 insertions(+), 1 deletion(-)

Tested-by: Lorenzo Bianconi <lorenzo@kernel.org>

> 
> diff --git a/include/net/mac80211.h b/include/net/mac80211.h
> index 775dbb982654..10e6fe215f0f 100644
> --- a/include/net/mac80211.h
> +++ b/include/net/mac80211.h
> @@ -3952,6 +3952,8 @@ struct ieee80211_prep_tx_info {
>   *	radar channel.
>   *	The caller is expected to set chandef pointer to NULL in order to
>   *	disable offchannel CAC/radar detection.
> + * @net_fill_forward_path: Called from .ndo_fill_forward_path in order to
> + *	resolve a path for hardware flow offloading
>   */
>  struct ieee80211_ops {
>  	void (*tx)(struct ieee80211_hw *hw,
> @@ -4282,6 +4284,11 @@ struct ieee80211_ops {
>  				     struct ieee80211_sta *sta, u8 flowid);
>  	int (*set_radar_offchan)(struct ieee80211_hw *hw,
>  				 struct cfg80211_chan_def *chandef);
> +	int (*net_fill_forward_path)(struct ieee80211_hw *hw,
> +				     struct ieee80211_vif *vif,
> +				     struct ieee80211_sta *sta,
> +				     struct net_device_path_ctx *ctx,
> +				     struct net_device_path *path);
>  };
>  
>  /**
> diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
> index cd3731cbf6c6..50a0cdadceec 100644
> --- a/net/mac80211/driver-ops.h
> +++ b/net/mac80211/driver-ops.h
> @@ -1483,4 +1483,26 @@ static inline void drv_twt_teardown_request(struct ieee80211_local *local,
>  	trace_drv_return_void(local);
>  }
>  
> +static inline int drv_net_fill_forward_path(struct ieee80211_local *local,
> +					    struct ieee80211_sub_if_data *sdata,
> +					    struct ieee80211_sta *sta,
> +					    struct net_device_path_ctx *ctx,
> +					    struct net_device_path *path)
> +{
> +	int ret = -EOPNOTSUPP;
> +
> +	sdata = get_bss_sdata(sdata);
> +	if (!check_sdata_in_driver(sdata))
> +		return -EIO;
> +
> +	trace_drv_net_fill_forward_path(local, sdata, sta);
> +	if (local->ops->net_fill_forward_path)
> +		ret = local->ops->net_fill_forward_path(&local->hw,
> +							&sdata->vif, sta,
> +							ctx, path);
> +	trace_drv_return_int(local, ret);
> +
> +	return ret;
> +}
> +
>  #endif /* __MAC80211_DRIVER_OPS */
> diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
> index 5666bbb8860b..08c0542c93a3 100644
> --- a/net/mac80211/ieee80211_i.h
> +++ b/net/mac80211/ieee80211_i.h
> @@ -1463,7 +1463,7 @@ struct ieee80211_local {
>  };
>  
>  static inline struct ieee80211_sub_if_data *
> -IEEE80211_DEV_TO_SUB_IF(struct net_device *dev)
> +IEEE80211_DEV_TO_SUB_IF(const struct net_device *dev)
>  {
>  	return netdev_priv(dev);
>  }
> diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
> index 9a2145c8192b..6012442cd0d6 100644
> --- a/net/mac80211/iface.c
> +++ b/net/mac80211/iface.c
> @@ -789,6 +789,66 @@ static const struct net_device_ops ieee80211_monitorif_ops = {
>  	.ndo_get_stats64	= ieee80211_get_stats64,
>  };
>  
> +
> +static int ieee80211_netdev_fill_forward_path(struct net_device_path_ctx *ctx,
> +					      struct net_device_path *path)
> +{
> +	struct ieee80211_sub_if_data *sdata;
> +	struct ieee80211_local *local;
> +	struct sta_info *sta;
> +	int ret = -ENOENT;
> +
> +	sdata = IEEE80211_DEV_TO_SUB_IF(ctx->dev);
> +	local = sdata->local;
> +
> +	if (!local->ops->net_fill_forward_path)
> +		return -EOPNOTSUPP;
> +
> +	rcu_read_lock();
> +	switch (sdata->vif.type) {
> +	case NL80211_IFTYPE_AP_VLAN:
> +		sta = rcu_dereference(sdata->u.vlan.sta);
> +		if (sta)
> +			break;
> +		if (sdata->wdev.use_4addr)
> +			goto out;
> +		if (is_multicast_ether_addr(ctx->daddr))
> +			goto out;
> +		sta = sta_info_get_bss(sdata, ctx->daddr);
> +		break;
> +	case NL80211_IFTYPE_AP:
> +		if (is_multicast_ether_addr(ctx->daddr))
> +			goto out;
> +		sta = sta_info_get(sdata, ctx->daddr);
> +		break;
> +	case NL80211_IFTYPE_STATION:
> +		if (sdata->wdev.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS) {
> +			sta = sta_info_get(sdata, ctx->daddr);
> +			if (sta && test_sta_flag(sta, WLAN_STA_TDLS_PEER)) {
> +				if (!test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
> +					goto out;
> +
> +				break;
> +			}
> +		}
> +
> +		sta = sta_info_get(sdata, sdata->u.mgd.bssid);
> +		break;
> +	default:
> +		goto out;
> +	}
> +
> +	if (!sta)
> +		goto out;
> +
> +	ret = drv_net_fill_forward_path(local, sdata, &sta->sta, ctx, path);
> +out:
> +	rcu_read_unlock();
> +
> +	return ret;
> +}
> +
> +
>  static const struct net_device_ops ieee80211_dataif_8023_ops = {
>  	.ndo_open		= ieee80211_open,
>  	.ndo_stop		= ieee80211_stop,
> @@ -798,6 +858,7 @@ static const struct net_device_ops ieee80211_dataif_8023_ops = {
>  	.ndo_set_mac_address	= ieee80211_change_mac,
>  	.ndo_select_queue	= ieee80211_netdev_select_queue,
>  	.ndo_get_stats64	= ieee80211_get_stats64,
> +	.ndo_fill_forward_path	= ieee80211_netdev_fill_forward_path,
>  };
>  
>  static bool ieee80211_iftype_supports_hdr_offload(enum nl80211_iftype iftype)
> diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h
> index 9e8381bef7ed..d91498f77796 100644
> --- a/net/mac80211/trace.h
> +++ b/net/mac80211/trace.h
> @@ -2892,6 +2892,13 @@ TRACE_EVENT(drv_twt_teardown_request,
>  	)
>  );
>  
> +DEFINE_EVENT(sta_event, drv_net_fill_forward_path,
> +	TP_PROTO(struct ieee80211_local *local,
> +		 struct ieee80211_sub_if_data *sdata,
> +		 struct ieee80211_sta *sta),
> +	TP_ARGS(local, sdata, sta)
> +);
> +
>  #endif /* !__MAC80211_DRIVER_TRACE || TRACE_HEADER_MULTI_READ */
>  
>  #undef TRACE_INCLUDE_PATH
> -- 
> 2.30.1
>