wifi: mac80211: process and save negotiated TID to Link mapping request

An MLD may send TID-to-Link mapping request frame to negotiate
TID to link mapping with a peer MLD.
Support handling negotiated TID-to-Link mapping request frame
by parsing the frame, asking the driver whether it supports the
received mapping or not, and sending a TID-to-Link mapping response
to the AP MLD.
Theoretically, links that became inactive due to the received TID-to-Link
mapping request, can be selected to be activated but this would require
tearing down the negotiated TID-to-Link mapping, which is still not
supported.

Signed-off-by: Ayala Beker <[email protected]>
Reviewed-by: Johannes Berg <[email protected]>
Reviewed-by: Gregory Greenman <[email protected]>
Signed-off-by: Miri Korenblit <[email protected]>
Link: https://msgid.link/20240102213313.0bc1a24fcc9d.Ie72e47dc6f8c77d4a2f0947b775ef6367fe0edac@changeid
Signed-off-by: Johannes Berg <[email protected]>

Author: AyalaBkr

include/net/mac80211.h

@@ -342,6 +342,7 @@ struct ieee80211_vif_chanctx_switch {
  *	status changed.
  * @BSS_CHANGED_EHT_PUNCTURING: The channel puncturing bitmap changed.
  * @BSS_CHANGED_MLD_VALID_LINKS: MLD valid links status changed.
+ * @BSS_CHANGED_MLD_TTLM: TID to link mapping was changed
  */
 enum ieee80211_bss_change {
 	BSS_CHANGED_ASSOC		= 1<<0,
@@ -378,6 +379,7 @@ enum ieee80211_bss_change {
 	BSS_CHANGED_UNSOL_BCAST_PROBE_RESP = 1<<31,
 	BSS_CHANGED_EHT_PUNCTURING	= BIT_ULL(32),
 	BSS_CHANGED_MLD_VALID_LINKS	= BIT_ULL(33),
+	BSS_CHANGED_MLD_TTLM		= BIT_ULL(34),
 
 	/* when adding here, make sure to change ieee80211_reconfig */
 };
@@ -1845,6 +1847,35 @@ struct ieee80211_vif_cfg {
 	u8 ap_addr[ETH_ALEN] __aligned(2);
 };
 
+#define IEEE80211_TTLM_NUM_TIDS 8
+
+/**
+ * struct ieee80211_neg_ttlm - negotiated TID to link map info
+ *
+ * @downlink: bitmap of active links per TID for downlink, or 0 if mapping for
+ *	this TID is not included.
+ * @uplink: bitmap of active links per TID for uplink, or 0 if mapping for this
+ *	TID is not included.
+ * @valid: info is valid or not.
+ */
+struct ieee80211_neg_ttlm {
+	u16 downlink[IEEE80211_TTLM_NUM_TIDS];
+	u16 uplink[IEEE80211_TTLM_NUM_TIDS];
+	bool valid;
+};
+
+/**
+ * enum ieee80211_neg_ttlm_res - return value for negotiated TTLM handling
+ * @NEG_TTLM_RES_ACCEPT: accept the request
+ * @NEG_TTLM_RES_REJECT: reject the request
+ * @NEG_TTLM_RES_SUGGEST_PREFERRED: reject and suggest a new mapping
+ */
+enum ieee80211_neg_ttlm_res {
+	NEG_TTLM_RES_ACCEPT,
+	NEG_TTLM_RES_REJECT,
+	NEG_TTLM_RES_SUGGEST_PREFERRED
+};
+
 /**
  * struct ieee80211_vif - per-interface data
  *
@@ -1863,6 +1894,11 @@ struct ieee80211_vif_cfg {
  *	API calls meant for that purpose.
  * @dormant_links: bitmap of valid but disabled links, or 0 for non-MLO.
  *	Must be a subset of valid_links.
+ * @suspended_links: subset of dormant_links representing links that are
+ *	suspended.
+ *	0 for non-MLO.
+ * @neg_ttlm: negotiated TID to link mapping info.
+ *	see &struct ieee80211_neg_ttlm.
  * @addr: address of this interface
  * @p2p: indicates whether this AP or STA interface is a p2p
  *	interface, i.e. a GO or p2p-sta respectively
@@ -1900,7 +1936,8 @@ struct ieee80211_vif {
 	struct ieee80211_vif_cfg cfg;
 	struct ieee80211_bss_conf bss_conf;
 	struct ieee80211_bss_conf __rcu *link_conf[IEEE80211_MLD_MAX_NUM_LINKS];
-	u16 valid_links, active_links, dormant_links;
+	u16 valid_links, active_links, dormant_links, suspended_links;
+	struct ieee80211_neg_ttlm neg_ttlm;
 	u8 addr[ETH_ALEN] __aligned(2);
 	bool p2p;
 
@@ -4293,6 +4330,10 @@ struct ieee80211_prep_tx_info {
  *	flow offloading for flows originating from the vif.
  *	Note that the driver must not assume that the vif driver_data is valid
  *	at this point, since the callback can be called during netdev teardown.
+ * @can_neg_ttlm: for managed interface, requests the driver to determine
+ *	if the requested TID-To-Link mapping can be accepted or not.
+ *	If it's not accepted the driver may suggest a preferred mapping and
+ *	modify @ttlm parameter with the suggested TID-to-Link mapping.
  */
 struct ieee80211_ops {
 	void (*tx)(struct ieee80211_hw *hw,
@@ -4673,6 +4714,9 @@ struct ieee80211_ops {
 			    struct net_device *dev,
 			    enum tc_setup_type type,
 			    void *type_data);
+	enum ieee80211_neg_ttlm_res
+	(*can_neg_ttlm)(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
+			struct ieee80211_neg_ttlm *ttlm);
 };
 
 /**

net/mac80211/driver-ops.h

@@ -1695,4 +1695,23 @@ int drv_change_sta_links(struct ieee80211_local *local,
 			 struct ieee80211_sta *sta,
 			 u16 old_links, u16 new_links);
 
+static inline enum ieee80211_neg_ttlm_res
+drv_can_neg_ttlm(struct ieee80211_local *local,
+		 struct ieee80211_sub_if_data *sdata,
+		 struct ieee80211_neg_ttlm *neg_ttlm)
+{
+	enum ieee80211_neg_ttlm_res res = NEG_TTLM_RES_REJECT;
+
+	might_sleep();
+	if (!check_sdata_in_driver(sdata))
+		return -EIO;
+
+	trace_drv_can_neg_ttlm(local, sdata, neg_ttlm);
+	if (local->ops->can_neg_ttlm)
+		res = local->ops->can_neg_ttlm(&local->hw, &sdata->vif,
+					       neg_ttlm);
+	trace_drv_neg_ttlm_res(local, sdata, res, neg_ttlm);
+
+	return res;
+}
 #endif /* __MAC80211_DRIVER_OPS */

net/mac80211/ieee80211_i.h

@@ -2603,6 +2603,8 @@ ieee80211_eht_cap_ie_to_sta_eht_cap(struct ieee80211_sub_if_data *sdata,
 				    const struct ieee80211_eht_cap_elem *eht_cap_ie_elem,
 				    u8 eht_cap_len,
 				    struct link_sta_info *link_sta);
+void ieee80211_process_neg_ttlm_req(struct ieee80211_sub_if_data *sdata,
+				    struct ieee80211_mgmt *mgmt, size_t len);
 
 void ieee80211_check_wbrf_support(struct ieee80211_local *local);
 void ieee80211_add_wbrf(struct ieee80211_local *local, struct cfg80211_chan_def *chandef);

net/mac80211/iface.c

@@ -1546,6 +1546,18 @@ static void ieee80211_iface_process_skb(struct ieee80211_local *local,
 		default:
 			break;
 		}
+	} else if (ieee80211_is_action(mgmt->frame_control) &&
+		   mgmt->u.action.category == WLAN_CATEGORY_PROTECTED_EHT) {
+		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
+			switch (mgmt->u.action.u.ttlm_req.action_code) {
+			case WLAN_PROTECTED_EHT_ACTION_TTLM_REQ:
+				ieee80211_process_neg_ttlm_req(sdata, mgmt,
+							       skb->len);
+				break;
+			default:
+				break;
+			}
+		}
 	} else if (ieee80211_is_ext(mgmt->frame_control)) {
 		if (sdata->vif.type == NL80211_IFTYPE_STATION)
 			ieee80211_sta_rx_queued_ext(sdata, skb);

net/mac80211/main.c

@@ -208,7 +208,8 @@ int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
 				   BSS_CHANGED_IBSS |\
 				   BSS_CHANGED_ARP_FILTER |\
 				   BSS_CHANGED_SSID |\
-				   BSS_CHANGED_MLD_VALID_LINKS)
+				   BSS_CHANGED_MLD_VALID_LINKS |\
+				   BSS_CHANGED_MLD_TTLM)
 
 void ieee80211_bss_info_change_notify(struct ieee80211_sub_if_data *sdata,
 				      u64 changed)