[PATCH RESEND wireless-next 18/18] wifi: mac80211: Add mac80211 support to handle NL80211_CMD_GET_SMD_CTX

[Pooventhiran G]

cfg80211 supports NL80211_CMD_GET_SMD_CTX from userspace on the current
AP MLD to collect the station's context on the target AP MLD's behalf;
this context is used by the target AP MLD to program its TX and RX
queues to support seamless roaming of the non-AP MLD.

Implement the get_smd_ctx cfg80211_op in mac80211 to invoke the driver
to collect the requested station context. Because context collection is
asynchronous, the driver signals completion later via
ieee80211_get_smd_ctx_done(), which packs the collected context into
NL80211_CMD_SMD_CTX_EVENT and delivers it to userspace as a multicast
event.

Signed-off-by: Pooventhiran G <pooventhiran.g@xxxxxxxxxxxxxxxx>
---
 include/net/mac80211.h    | 23 +++++++++++++++++++++++
 net/mac80211/cfg.c        | 34 ++++++++++++++++++++++++++++++++++
 net/mac80211/driver-ops.h | 24 ++++++++++++++++++++++++
 net/mac80211/sta_info.c   |  6 ++++++
 net/mac80211/trace.h      | 27 +++++++++++++++++++++++++++
 5 files changed, 114 insertions(+)

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index e0e13f0ed31f..f16112e41594 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -2528,6 +2528,21 @@ enum ieee80211_sta_state {
 	IEEE80211_STA_AUTHORIZED,
 };
 
+/**
+ * ieee80211_get_smd_ctx_done - Deliver async get_smd_ctx result to nl80211
+ * @vif: virtual interface
+ * @sta_addr: non-AP MLD address the context was collected for
+ * @st_info: SMD BSS Transition Info (@st_info or @st_info->ctx may be NULL to
+ *	indicate failure). @st_info is owned by the driver.
+ *
+ * Called by the driver after the %NL80211_CMD_GET_SMD_CTX context collection
+ * is complete. mac80211 forwards the result to cfg80211 which finds the pending
+ * nl80211 request and sends reply to userspace.
+ */
+void ieee80211_get_smd_ctx_done(struct ieee80211_vif *vif,
+				const u8 *sta_addr,
+				struct cfg80211_smd_transition_info *st_info);
+
 /**
  * enum ieee80211_sta_rx_bandwidth - station RX bandwidth
  * @IEEE80211_STA_RX_BW_20: station can only receive 20 MHz
@@ -4782,6 +4797,11 @@ enum ieee80211_sta_smd_state {
  *	The callback can sleep.
  * @set_smd_ctx: Set the UHR SMD context for the non-AP MLD. This is used on
  *	the target AP MLD side to program dynamic context.
+ * @get_smd_ctx: Get the UHR SMD context for the non-AP MLD. This is used in
+ *	the current AP MLD side on behalf of the target AP MLD to collect
+ *	dynamic context, when the non-AP MLD sends ST Execute frame directly
+ *	to the target. Since the response is asynchronous, the drivers that
+ *	implement this should not store reference to @sta.
  */
 struct ieee80211_ops {
 	void (*tx)(struct ieee80211_hw *hw,
@@ -5191,6 +5211,9 @@ struct ieee80211_ops {
 	int (*set_smd_ctx)(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			   struct ieee80211_sta *sta,
 			   struct cfg80211_smd_transition_info *st_info);
+	int (*get_smd_ctx)(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
+			   struct ieee80211_sta *sta,
+			   enum nl80211_smd_ctx_type type);
 };
 
 /**
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 268d5f42293a..a33ce96a4752 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -6104,6 +6104,39 @@ static int ieee80211_set_smd_ctx(struct wiphy *wiphy, struct wireless_dev *wdev,
 	return drv_set_smd_ctx(local, sdata, &sta->sta, st_info);
 }
 
+static int ieee80211_get_smd_ctx(struct wiphy *wiphy, struct wireless_dev *wdev,
+				 const u8 *addr,
+				 enum nl80211_smd_ctx_type type)
+{
+	struct ieee80211_local *local = wiphy_priv(wiphy);
+	struct ieee80211_sub_if_data *sdata;
+	struct sta_info *sta;
+
+	lockdep_assert_wiphy(wiphy);
+
+	sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
+
+	if (sdata->vif.type != NL80211_IFTYPE_AP &&
+	    sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
+		return -EOPNOTSUPP;
+
+	sta = sta_info_get_bss(sdata, addr);
+	if (!sta || !sta->sta.smd_params.smd_sta)
+		return -EINVAL;
+
+	return drv_get_smd_ctx(local, sdata, &sta->sta, type);
+}
+
+void ieee80211_get_smd_ctx_done(struct ieee80211_vif *vif,
+				const u8 *sta_addr,
+				struct cfg80211_smd_transition_info *st_info)
+{
+	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+
+	cfg80211_get_smd_ctx_done(&sdata->wdev, sta_addr, st_info);
+}
+EXPORT_SYMBOL(ieee80211_get_smd_ctx_done);
+
 const struct cfg80211_ops mac80211_config_ops = {
 	.add_virtual_intf = ieee80211_add_iface,
 	.del_virtual_intf = ieee80211_del_iface,
@@ -6223,4 +6256,5 @@ const struct cfg80211_ops mac80211_config_ops = {
 	.nan_set_local_sched = ieee80211_set_local_nan_sched,
 	.nan_set_peer_sched = ieee80211_set_peer_nan_sched,
 	.set_smd_ctx = ieee80211_set_smd_ctx,
+	.get_smd_ctx = ieee80211_get_smd_ctx,
 };
diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index e764dd394de2..0339ff71cd4a 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -1844,4 +1844,28 @@ static inline int drv_set_smd_ctx(struct ieee80211_local *local,
 	return ret;
 }
 
+static inline int drv_get_smd_ctx(struct ieee80211_local *local,
+				  struct ieee80211_sub_if_data *sdata,
+				  struct ieee80211_sta *sta,
+				  enum nl80211_smd_ctx_type type)
+{
+	int ret;
+
+	if (!sdata || !local->ops->get_smd_ctx)
+		return -EOPNOTSUPP;
+
+	sdata = get_bss_sdata(sdata);
+
+	lockdep_assert_wiphy(local->hw.wiphy);
+
+	if (!check_sdata_in_driver(sdata))
+		return -EIO;
+
+	trace_drv_get_smd_ctx(local, sdata, sta, type);
+	ret = local->ops->get_smd_ctx(&local->hw, &sdata->vif, sta, type);
+	trace_drv_return_int(local, ret);
+
+	return ret;
+}
+
 #endif /* __MAC80211_DRIVER_OPS */
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 5aa6f5b481e3..9ea0a8791289 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -1312,6 +1312,7 @@ static int __must_check __sta_info_destroy_part1(struct sta_info *sta)
 {
 	struct ieee80211_local *local;
 	struct ieee80211_sub_if_data *sdata;
+	struct wireless_dev *wdev;
 	int ret, i;
 
 	might_sleep();
@@ -1321,6 +1322,7 @@ static int __must_check __sta_info_destroy_part1(struct sta_info *sta)
 
 	local = sta->local;
 	sdata = sta->sdata;
+	wdev = &sdata->wdev;
 
 	lockdep_assert_wiphy(local->hw.wiphy);
 
@@ -1390,6 +1392,10 @@ static int __must_check __sta_info_destroy_part1(struct sta_info *sta)
 	    rcu_access_pointer(sdata->u.vlan.sta) == sta)
 		RCU_INIT_POINTER(sdata->u.vlan.sta, NULL);
 
+	if (sdata->vif.type == NL80211_IFTYPE_AP ||
+	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
+		cfg80211_free_pending_smd_ctx_req(wdev, sta->addr);
+
 	return 0;
 }
 
diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h
index 7aba79e441cf..38ad5076232d 100644
--- a/net/mac80211/trace.h
+++ b/net/mac80211/trace.h
@@ -3487,6 +3487,33 @@ TRACE_EVENT(drv_set_smd_ctx,
 	)
 );
 
+TRACE_EVENT(drv_get_smd_ctx,
+	TP_PROTO(struct ieee80211_local *local,
+		 struct ieee80211_sub_if_data *sdata,
+		 struct ieee80211_sta *sta,
+		 enum nl80211_smd_ctx_type type),
+
+	TP_ARGS(local, sdata, sta, type),
+
+	TP_STRUCT__entry(
+		LOCAL_ENTRY
+		VIF_ENTRY
+		STA_ENTRY
+		__field(u8, st_type)
+	),
+
+	TP_fast_assign(
+		LOCAL_ASSIGN;
+		VIF_ASSIGN;
+		STA_ASSIGN;
+		__entry->st_type = type;
+	),
+
+	TP_printk(LOCAL_PR_FMT VIF_PR_FMT STA_PR_FMT ", ST type=%u",
+		  LOCAL_PR_ARG, VIF_PR_ARG, STA_PR_ARG, __entry->st_type
+	)
+);
+
 #endif /* !__MAC80211_DRIVER_TRACE || TRACE_HEADER_MULTI_READ */
 
 #undef TRACE_INCLUDE_PATH

-- 
2.34.1