mac80211: rework tx encapsulation offload API

The current API (which lets the driver turn on/off per vif directly) has a
number of limitations:
- it does not deal with AP_VLAN
- conditions for enabling (no tkip, no monitor) are only checked at
  add_interface time
- no way to indicate 4-addr support

In order to address this, store offload flags in struct ieee80211_vif
(easy to extend for decap offload later). mac80211 initially sets the enable
flag, but gives the driver a chance to modify it before its settings are
applied. In addition to the .add_interface op, a .update_vif_offload op is
introduced, which can be used for runtime changes.

If a driver can't disable encap offload at runtime, or if it has some extra
limitations, it can simply override the flags within those ops.

Support for encap offload with 4-address mode interfaces can be enabled
by setting a flag from .add_interface or .update_vif_offload.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20200908123702.88454-6-nbd@nbd.name
[resolved conflict with commit aa2092a9bab3 ("ath11k: add raw mode and
software crypto support")]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 113 insertions, 56 deletions

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 9740ae8fa697..02bb94de7bde 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -43,6 +43,7 @@
  */
 
 static void ieee80211_iface_work(struct work_struct *work);
+static void ieee80211_set_vif_encap_ops(struct ieee80211_sub_if_data *sdata);
 
 bool __ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata)
 {
@@ -348,6 +349,85 @@ static int ieee80211_check_queues(struct ieee80211_sub_if_data *sdata,
 	return 0;
 }
 
+static bool ieee80211_iftype_supports_encap_offload(enum nl80211_iftype iftype)
+{
+	switch (iftype) {
+	/* P2P GO and client are mapped to AP/STATION types */
+	case NL80211_IFTYPE_AP:
+	case NL80211_IFTYPE_STATION:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool ieee80211_set_sdata_offload_flags(struct ieee80211_sub_if_data *sdata)
+{
+	struct ieee80211_local *local = sdata->local;
+	u32 flags;
+
+	flags = sdata->vif.offload_flags;
+
+	if (ieee80211_hw_check(&local->hw, SUPPORTS_TX_ENCAP_OFFLOAD) &&
+	    ieee80211_iftype_supports_encap_offload(sdata->vif.type)) {
+		flags |= IEEE80211_OFFLOAD_ENCAP_ENABLED;
+
+		if (!ieee80211_hw_check(&local->hw, SUPPORTS_TX_FRAG) &&
+		    local->hw.wiphy->frag_threshold != (u32)-1)
+			flags &= ~IEEE80211_OFFLOAD_ENCAP_ENABLED;
+
+		if (local->monitors)
+			flags &= ~IEEE80211_OFFLOAD_ENCAP_ENABLED;
+	} else {
+		flags &= ~IEEE80211_OFFLOAD_ENCAP_ENABLED;
+	}
+
+	if (sdata->vif.offload_flags == flags)
+		return false;
+
+	sdata->vif.offload_flags = flags;
+	return true;
+}
+
+
+static void ieee80211_recalc_sdata_offload(struct ieee80211_sub_if_data *sdata)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_sub_if_data *vsdata;
+
+	if (ieee80211_set_sdata_offload_flags(sdata)) {
+		drv_update_vif_offload(local, sdata);
+		ieee80211_set_vif_encap_ops(sdata);
+	}
+
+	list_for_each_entry(vsdata, &local->interfaces, list) {
+		if (vsdata->vif.type != NL80211_IFTYPE_AP_VLAN ||
+		    vsdata->bss != &sdata->u.ap)
+			continue;
+
+		ieee80211_set_vif_encap_ops(vsdata);
+	}
+}
+
+void ieee80211_recalc_offload(struct ieee80211_local *local)
+{
+	struct ieee80211_sub_if_data *sdata;
+
+	if (!ieee80211_hw_check(&local->hw, SUPPORTS_TX_ENCAP_OFFLOAD))
+		return;
+
+	mutex_lock(&local->iflist_mtx);
+
+	list_for_each_entry(sdata, &local->interfaces, list) {
+		if (!ieee80211_sdata_running(sdata))
+			continue;
+
+		ieee80211_recalc_sdata_offload(sdata);
+	}
+
+	mutex_unlock(&local->iflist_mtx);
+}
+
 void ieee80211_adjust_monitor_flags(struct ieee80211_sub_if_data *sdata,
 				    const int offset)
 {
@@ -587,6 +667,7 @@ int ieee80211_do_open(struct wireless_dev *wdev, bool coming_up)
 		if (rtnl_dereference(sdata->bss->beacon)) {
 			ieee80211_vif_vlan_copy_chanctx(sdata);
 			netif_carrier_on(dev);
+			ieee80211_set_vif_encap_ops(sdata);
 		} else {
 			netif_carrier_off(dev);
 		}
@@ -616,6 +697,7 @@ int ieee80211_do_open(struct wireless_dev *wdev, bool coming_up)
 
 		ieee80211_adjust_monitor_flags(sdata, 1);
 		ieee80211_configure_filter(local);
+		ieee80211_recalc_offload(local);
 		mutex_lock(&local->mtx);
 		ieee80211_recalc_idle(local);
 		mutex_unlock(&local->mtx);
@@ -625,10 +707,13 @@ int ieee80211_do_open(struct wireless_dev *wdev, bool coming_up)
 	default:
 		if (coming_up) {
 			ieee80211_del_virtual_monitor(local);
+			ieee80211_set_sdata_offload_flags(sdata);
 
 			res = drv_add_interface(local, sdata);
 			if (res)
 				goto err_stop;
+
+			ieee80211_set_vif_encap_ops(sdata);
 			res = ieee80211_check_queues(sdata,
 				ieee80211_vif_type_p2p(&sdata->vif));
 			if (res)
@@ -1227,61 +1312,6 @@ static const struct net_device_ops ieee80211_dataif_8023_ops = {
 	.ndo_get_stats64	= ieee80211_get_stats64,
 };
 
-static void __ieee80211_set_hw_80211_encap(struct ieee80211_sub_if_data *sdata,
-					   bool enable)
-{
-	sdata->dev->netdev_ops = enable ? &ieee80211_dataif_8023_ops :
-					  &ieee80211_dataif_ops;
-	sdata->hw_80211_encap = enable;
-}
-
-bool ieee80211_set_hw_80211_encap(struct ieee80211_vif *vif, bool enable)
-{
-	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
-	struct ieee80211_local *local = sdata->local;
-	struct ieee80211_sub_if_data *iter;
-	struct ieee80211_key *key;
-
-	mutex_lock(&local->iflist_mtx);
-	list_for_each_entry(iter, &local->interfaces, list) {
-		struct ieee80211_sub_if_data *disable = NULL;
-
-		if (vif->type == NL80211_IFTYPE_MONITOR) {
-			disable = iter;
-			__ieee80211_set_hw_80211_encap(iter, false);
-		} else if (iter->vif.type == NL80211_IFTYPE_MONITOR) {
-			disable = sdata;
-			enable = false;
-		}
-		if (disable)
-			sdata_dbg(disable,
-				  "disable hw 80211 encap due to mon co-exist\n");
-	}
-	mutex_unlock(&local->iflist_mtx);
-
-	if (enable == sdata->hw_80211_encap)
-		return enable;
-
-	if (!sdata->dev)
-		return false;
-
-	if (!ieee80211_hw_check(&local->hw, SUPPORTS_TX_FRAG) &&
-	    (local->hw.wiphy->frag_threshold != (u32)-1))
-		enable = false;
-
-	mutex_lock(&sdata->local->key_mtx);
-	list_for_each_entry(key, &sdata->key_list, list) {
-		if (key->conf.cipher == WLAN_CIPHER_SUITE_TKIP)
-			enable = false;
-	}
-	mutex_unlock(&sdata->local->key_mtx);
-
-	__ieee80211_set_hw_80211_encap(sdata, enable);
-
-	return enable;
-}
-EXPORT_SYMBOL(ieee80211_set_hw_80211_encap);
-
 static void ieee80211_if_free(struct net_device *dev)
 {
 	free_percpu(dev->tstats);
@@ -1302,6 +1332,32 @@ static void ieee80211_if_setup_no_queue(struct net_device *dev)
 	dev->priv_flags |= IFF_NO_QUEUE;
 }
 
+static void ieee80211_set_vif_encap_ops(struct ieee80211_sub_if_data *sdata)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_sub_if_data *bss = sdata;
+	bool enabled;
+
+	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
+		if (!sdata->bss)
+			return;
+
+		bss = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
+	}
+
+	if (!ieee80211_hw_check(&local->hw, SUPPORTS_TX_ENCAP_OFFLOAD) ||
+	    !ieee80211_iftype_supports_encap_offload(bss->vif.type))
+		return;
+
+	enabled = bss->vif.offload_flags & IEEE80211_OFFLOAD_ENCAP_ENABLED;
+	if (sdata->wdev.use_4addr &&
+	    !(bss->vif.offload_flags & IEEE80211_OFFLOAD_ENCAP_4ADDR))
+		enabled = false;
+
+	sdata->dev->netdev_ops = enabled ? &ieee80211_dataif_8023_ops :
+					   &ieee80211_dataif_ops;
+}
+
 static void ieee80211_iface_work(struct work_struct *work)
 {
 	struct ieee80211_sub_if_data *sdata =
@@ -1484,7 +1540,6 @@ static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,
 	sdata->vif.bss_conf.txpower = INT_MIN; /* unset */
 
 	sdata->noack_map = 0;
-	sdata->hw_80211_encap = false;
 
 	/* only monitor/p2p-device differ */
 	if (sdata->dev) {
@@ -1619,6 +1674,7 @@ static int ieee80211_runtime_change_iftype(struct ieee80211_sub_if_data *sdata,
 
 	ieee80211_teardown_sdata(sdata);
 
+	ieee80211_set_sdata_offload_flags(sdata);
 	ret = drv_change_interface(local, sdata, internal_type, p2p);
 	if (ret)
 		type = ieee80211_vif_type_p2p(&sdata->vif);
@@ -1631,6 +1687,7 @@ static int ieee80211_runtime_change_iftype(struct ieee80211_sub_if_data *sdata,
 	ieee80211_check_queues(sdata, type);
 
 	ieee80211_setup_sdata(sdata, type);
+	ieee80211_set_vif_encap_ops(sdata);
 
 	err = ieee80211_do_open(&sdata->wdev, false);
 	WARN(err, "type change: do_open returned %d", err);