wifi: mac80211: add support for NDP ADDBA/DELBA for S1G

S1G defines use of NDP Block Ack (BA) for aggregation, requiring negotiation
of NDP ADDBA/DELBA action frames. If the S1G recipient supports HT-immediate
block ack, the sender must send an NDP ADDBA Request indicating it expects
only NDP BlockAck frames for the agreement.

Introduce support for NDP ADDBA and DELBA exchange in mac80211. The
implementation negotiates the BA mechanism during setup based on station
capabilities and driver support (IEEE80211_HW_SUPPORTS_NDP_BLOCKACK).
If negotiation fails due to mismatched expectations, a rejection with status code
WLAN_STATUS_REJECTED_NDP_BLOCK_ACK_SUGGESTED is returned as per IEEE 802.11-2024.

Trace sample:

IEEE 802.11 Wireless Management
    Fixed parameters
        Category code: Block Ack (3)
        Action code: NDP ADDBA Request (0x80)
        Dialog token: 0x01
        Block Ack Parameters: 0x1003, A-MSDUs, Block Ack Policy
            .... .... .... ...1 = A-MSDUs: Permitted in QoS Data MPDUs
            .... .... .... ..1. = Block Ack Policy: Immediate Block Ack
            .... .... ..00 00.. = Traffic Identifier: 0x0
            0001 0000 00.. .... = Number of Buffers (1 Buffer = 2304 Bytes): 64
        Block Ack Timeout: 0x0000
        Block Ack Starting Sequence Control (SSC): 0x0010
            .... .... .... 0000 = Fragment: 0
            0000 0000 0001 .... = Starting Sequence Number: 1

IEEE 802.11 Wireless Management
    Fixed parameters
        Category code: Block Ack (3)
        Action code: NDP ADDBA Response (0x81)
        Dialog token: 0x02
        Status code: BlockAck negotiation refused because, due to buffer constraints and other unspecified reasons, the recipient prefers to generate only NDP BlockAck frames (0x006d)
        Block Ack Parameters: 0x1002, Block Ack Policy
            .... .... .... ...0 = A-MSDUs: Not Permitted
            .... .... .... ..1. = Block Ack Policy: Immediate Block Ack
            .... .... ..00 00.. = Traffic Identifier: 0x0
            0001 0000 00.. .... = Number of Buffers (1 Buffer = 2304 Bytes): 64
        Block Ack Timeout: 0x0000

Signed-off-by: Ria Thomas <ria.thomas@morsemicro.com>
Link: https://patch.msgid.link/20260305091304.310990-1-ria.thomas@morsemicro.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 21 insertions, 3 deletions

diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c
index 0a2be8cb600f..0140ac826b23 100644
--- a/net/mac80211/agg-rx.c
+++ b/net/mac80211/agg-rx.c
@@ -94,7 +94,8 @@ void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
 	/* check if this is a self generated aggregation halt */
 	if (initiator == WLAN_BACK_RECIPIENT && tx)
 		ieee80211_send_delba(sta->sdata, sta->sta.addr,
-				     tid, WLAN_BACK_RECIPIENT, reason);
+				     tid, WLAN_BACK_RECIPIENT, reason,
+				     ieee80211_s1g_use_ndp_ba(sta->sdata, sta));
 
 	/*
 	 * return here in case tid_rx is not assigned - which will happen if
@@ -240,6 +241,7 @@ static void ieee80211_send_addba_resp(struct sta_info *sta, u8 *da, u16 tid,
 	struct sk_buff *skb;
 	struct ieee80211_mgmt *mgmt;
 	bool amsdu = ieee80211_hw_check(&local->hw, SUPPORTS_AMSDU_IN_AMPDU);
+	bool use_ndp = ieee80211_s1g_use_ndp_ba(sdata, sta);
 	u16 capab;
 
 	skb = dev_alloc_skb(sizeof(*mgmt) +
@@ -253,7 +255,8 @@ static void ieee80211_send_addba_resp(struct sta_info *sta, u8 *da, u16 tid,
 
 	skb_put(skb, 2 + sizeof(mgmt->u.action.addba_resp));
 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
-	mgmt->u.action.action_code = WLAN_ACTION_ADDBA_RESP;
+	mgmt->u.action.action_code = use_ndp ?
+		WLAN_ACTION_NDP_ADDBA_RESP : WLAN_ACTION_ADDBA_RESP;
 
 	mgmt->u.action.addba_resp.dialog_token = dialog_token;
 
@@ -276,6 +279,7 @@ void __ieee80211_start_rx_ba_session(struct sta_info *sta,
 				     u8 dialog_token, u16 timeout,
 				     u16 start_seq_num, u16 ba_policy, u16 tid,
 				     u16 buf_size, bool tx, bool auto_seq,
+				     bool req_ndp,
 				     const u8 addba_ext_data)
 {
 	struct ieee80211_local *local = sta->sdata->local;
@@ -301,6 +305,18 @@ void __ieee80211_start_rx_ba_session(struct sta_info *sta,
 		goto end;
 	}
 
+	if (tx && ieee80211_s1g_use_ndp_ba(sta->sdata, sta) && !req_ndp) {
+		/*
+		 * According to IEEE 802.11-2024: Inform S1G originator
+		 * ADDBA rejected as NDP BlockAck is preferred
+		 */
+		status = WLAN_STATUS_REJECTED_NDP_BLOCK_ACK_SUGGESTED;
+		ht_dbg(sta->sdata,
+		       "Rejecting AddBA Req from %pM tid %u - require NDP BlockAck\n",
+		       sta->sta.addr, tid);
+		goto end;
+	}
+
 	if (!sta->sta.valid_links &&
 	    !sta->sta.deflink.ht_cap.ht_supported &&
 	    !sta->sta.deflink.he_cap.has_he &&
@@ -474,6 +490,7 @@ void ieee80211_process_addba_request(struct ieee80211_local *local,
 				     struct ieee80211_mgmt *mgmt,
 				     size_t len)
 {
+	bool req_ndp = mgmt->u.action.action_code == WLAN_ACTION_NDP_ADDBA_REQ;
 	u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
 	u8 dialog_token, addba_ext_data;
 
@@ -498,7 +515,8 @@ void ieee80211_process_addba_request(struct ieee80211_local *local,
 
 	__ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
 					start_seq_num, ba_policy, tid,
-					buf_size, true, false, addba_ext_data);
+					buf_size, true, false,
+					req_ndp, addba_ext_data);
 }
 
 void ieee80211_manage_rx_ba_offl(struct ieee80211_vif *vif,