mac80211: introduce individual TWT support in AP mode

Introduce TWT action frames parsing support to mac80211.
Currently just individual TWT agreement are support in AP mode.
Whenever the AP receives a TWT action frame from an associated client,
after performing sanity checks, it will notify the underlay driver with
requested parameters in order to check if they are supported and if there
is enough room for a new agreement. The driver is expected to set the
agreement result and report it to mac80211.

Drivers supporting this have two new callbacks:
 - add_twt_setup (mandatory)
 - twt_teardown_request (optional)

mac80211 will send an action frame reply according to the result
reported by the driver.

Tested-by: Peter Chiu <chui-hao.chiu@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/257512f2e22ba42b9f2624942a128dd8f141de4b.1629741512.git.lorenzo@kernel.org
[use le16p_replace_bits(), minor cleanups, use (void *) casts,
 fix to use ieee80211_get_he_iftype_cap() correctly]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 180 insertions, 0 deletions

diff --git a/net/mac80211/s1g.c b/net/mac80211/s1g.c
index c33f332b049a..7e35ab5b6166 100644
--- a/net/mac80211/s1g.c
+++ b/net/mac80211/s1g.c
@@ -6,6 +6,7 @@
 #include <linux/ieee80211.h>
 #include <net/mac80211.h>
 #include "ieee80211_i.h"
+#include "driver-ops.h"
 
 void ieee80211_s1g_sta_rate_init(struct sta_info *sta)
 {
@@ -14,3 +15,182 @@ void ieee80211_s1g_sta_rate_init(struct sta_info *sta)
 	sta->rx_stats.last_rate =
 			STA_STATS_FIELD(TYPE, STA_STATS_RATE_TYPE_S1G);
 }
+
+bool ieee80211_s1g_is_twt_setup(struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *)skb->data;
+
+	if (likely(!ieee80211_is_action(mgmt->frame_control)))
+		return false;
+
+	if (likely(mgmt->u.action.category != WLAN_CATEGORY_S1G))
+		return false;
+
+	return mgmt->u.action.u.s1g.action_code == WLAN_S1G_TWT_SETUP;
+}
+
+static void
+ieee80211_s1g_send_twt_setup(struct ieee80211_sub_if_data *sdata, const u8 *da,
+			     const u8 *bssid, struct ieee80211_twt_setup *twt)
+{
+	int len = IEEE80211_MIN_ACTION_SIZE + 4 + twt->length;
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_mgmt *mgmt;
+	struct sk_buff *skb;
+
+	skb = dev_alloc_skb(local->hw.extra_tx_headroom + len);
+	if (!skb)
+		return;
+
+	skb_reserve(skb, local->hw.extra_tx_headroom);
+	mgmt = skb_put_zero(skb, len);
+	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
+					  IEEE80211_STYPE_ACTION);
+	memcpy(mgmt->da, da, ETH_ALEN);
+	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
+	memcpy(mgmt->bssid, bssid, ETH_ALEN);
+
+	mgmt->u.action.category = WLAN_CATEGORY_S1G;
+	mgmt->u.action.u.s1g.action_code = WLAN_S1G_TWT_SETUP;
+	memcpy(mgmt->u.action.u.s1g.variable, twt, 3 + twt->length);
+
+	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
+					IEEE80211_TX_INTFL_MLME_CONN_TX |
+					IEEE80211_TX_CTL_REQ_TX_STATUS;
+	ieee80211_tx_skb(sdata, skb);
+}
+
+static void
+ieee80211_s1g_send_twt_teardown(struct ieee80211_sub_if_data *sdata,
+				const u8 *da, const u8 *bssid, u8 flowid)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_mgmt *mgmt;
+	struct sk_buff *skb;
+	u8 *id;
+
+	skb = dev_alloc_skb(local->hw.extra_tx_headroom +
+			    IEEE80211_MIN_ACTION_SIZE + 2);
+	if (!skb)
+		return;
+
+	skb_reserve(skb, local->hw.extra_tx_headroom);
+	mgmt = skb_put_zero(skb, IEEE80211_MIN_ACTION_SIZE + 2);
+	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
+					  IEEE80211_STYPE_ACTION);
+	memcpy(mgmt->da, da, ETH_ALEN);
+	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
+	memcpy(mgmt->bssid, bssid, ETH_ALEN);
+
+	mgmt->u.action.category = WLAN_CATEGORY_S1G;
+	mgmt->u.action.u.s1g.action_code = WLAN_S1G_TWT_TEARDOWN;
+	id = (u8 *)mgmt->u.action.u.s1g.variable;
+	*id = flowid;
+
+	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
+					IEEE80211_TX_CTL_REQ_TX_STATUS;
+	ieee80211_tx_skb(sdata, skb);
+}
+
+static void
+ieee80211_s1g_rx_twt_setup(struct ieee80211_sub_if_data *sdata,
+			   struct sta_info *sta, struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *mgmt = (void *)skb->data;
+	struct ieee80211_twt_setup *twt = (void *)mgmt->u.action.u.s1g.variable;
+	struct ieee80211_twt_params *twt_agrt = (void *)twt->params;
+
+	twt_agrt->req_type &= cpu_to_le16(~IEEE80211_TWT_REQTYPE_REQUEST);
+
+	/* broadcast TWT not supported yet */
+	if (twt->control & IEEE80211_TWT_CONTROL_NEG_TYPE_BROADCAST) {
+		le16p_replace_bits(&twt_agrt->req_type,
+				   TWT_SETUP_CMD_REJECT,
+				   IEEE80211_TWT_REQTYPE_SETUP_CMD);
+		goto out;
+	}
+
+	drv_add_twt_setup(sdata->local, sdata, &sta->sta, twt);
+out:
+	ieee80211_s1g_send_twt_setup(sdata, mgmt->sa, sdata->vif.addr, twt);
+}
+
+static void
+ieee80211_s1g_rx_twt_teardown(struct ieee80211_sub_if_data *sdata,
+			      struct sta_info *sta, struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *)skb->data;
+
+	drv_twt_teardown_request(sdata->local, sdata, &sta->sta,
+				 mgmt->u.action.u.s1g.variable[0]);
+}
+
+static void
+ieee80211_s1g_tx_twt_setup_fail(struct ieee80211_sub_if_data *sdata,
+				struct sta_info *sta, struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *)skb->data;
+	struct ieee80211_twt_setup *twt = (void *)mgmt->u.action.u.s1g.variable;
+	struct ieee80211_twt_params *twt_agrt = (void *)twt->params;
+	u8 flowid = le16_get_bits(twt_agrt->req_type,
+				  IEEE80211_TWT_REQTYPE_FLOWID);
+
+	drv_twt_teardown_request(sdata->local, sdata, &sta->sta, flowid);
+
+	ieee80211_s1g_send_twt_teardown(sdata, mgmt->sa, sdata->vif.addr,
+					flowid);
+}
+
+void ieee80211_s1g_rx_twt_action(struct ieee80211_sub_if_data *sdata,
+				 struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *)skb->data;
+	struct ieee80211_local *local = sdata->local;
+	struct sta_info *sta;
+
+	mutex_lock(&local->sta_mtx);
+
+	sta = sta_info_get_bss(sdata, mgmt->sa);
+	if (!sta)
+		goto out;
+
+	switch (mgmt->u.action.u.s1g.action_code) {
+	case WLAN_S1G_TWT_SETUP:
+		ieee80211_s1g_rx_twt_setup(sdata, sta, skb);
+		break;
+	case WLAN_S1G_TWT_TEARDOWN:
+		ieee80211_s1g_rx_twt_teardown(sdata, sta, skb);
+		break;
+	default:
+		break;
+	}
+
+out:
+	mutex_unlock(&local->sta_mtx);
+}
+
+void ieee80211_s1g_status_twt_action(struct ieee80211_sub_if_data *sdata,
+				     struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *)skb->data;
+	struct ieee80211_local *local = sdata->local;
+	struct sta_info *sta;
+
+	mutex_lock(&local->sta_mtx);
+
+	sta = sta_info_get_bss(sdata, mgmt->da);
+	if (!sta)
+		goto out;
+
+	switch (mgmt->u.action.u.s1g.action_code) {
+	case WLAN_S1G_TWT_SETUP:
+		/* process failed twt setup frames */
+		ieee80211_s1g_tx_twt_setup_fail(sdata, sta, skb);
+		break;
+	default:
+		break;
+	}
+
+out:
+	mutex_unlock(&local->sta_mtx);
+}