[PATCH RESEND wireless-next 13/18] wifi: cfg80211/mac80211: Handle UHR Link Reconfiguration frame

[Pooventhiran G <pooventhiran.g@oss.qualcomm.com>]

The UHR Link Reconfiguration Request frame triggers SMD BSS Transition
on the current AP MLD. At the point where mac80211 forwards this
frame to userspace via nl80211_send_mgmt(), the driver has already
collected the STA's dynamic context (SN, PN, BlockAck state) and
attached it to the SKB via the SKB_EXT_WIRELESS extension. But this
information is not known by nl80211 to pack the context with the frame
sent to userspace.

Add handling for the UHR ST Preparation and Execution request frames
in ieee80211_rx_h_userspace_mgmt() to pull the ieee80211_smd_ctx
pointer from the SKB extension and store it in cfg80211_rx_info, so
that nl80211_send_mgmt() can include it in the NL80211_CMD_FRAME event.

Signed-off-by: Pooventhiran G <pooventhiran.g@oss.qualcomm.com>
---
 include/linux/ieee80211-uhr.h | 59 +++++++++++++++++++++++++++++++++++++++++++
 include/net/cfg80211.h        | 13 ++++++++++
 net/mac80211/rx.c             | 22 ++++++++++++++++
 3 files changed, 94 insertions(+)

diff --git a/include/linux/ieee80211-uhr.h b/include/linux/ieee80211-uhr.h
index f904b1e65f10..cda8251a1a9a 100644
--- a/include/linux/ieee80211-uhr.h
+++ b/include/linux/ieee80211-uhr.h
@@ -743,6 +743,65 @@ ieee80211_uhr_mode_change_tuple_size(const struct ieee80211_uhr_mode_change_tupl
 			     IEEE80211_UHR_MODE_CHANGE_CONTROL_MODE_LENGTH);
 }
 
+/**
+ * ieee80211_is_uhr_link_reconf_req - check if frame is UHR Link Reconf Request
+ * @skb: the SKB to check
+ * Return: whether or not the frame is a UHR Link Reconf Request frame
+ */
+static inline bool ieee80211_is_uhr_link_reconf_req(struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *mgmt = (void *)skb->data;
+	u8 category, action;
+
+	if (!ieee80211_is_action(mgmt->frame_control))
+		return false;
+
+	if (skb->len < IEEE80211_MIN_ACTION_SIZE(uhr_link_reconf_req))
+		return false;
+
+	category = mgmt->u.action.category;
+	action = mgmt->u.action.action_code;
+
+	return category == WLAN_CATEGORY_PROTECTED_UHR &&
+	       action == IEEE80211_PROTECTED_UHR_ACTION_LINK_RECONFIG_REQUEST;
+}
+
+/**
+ * ieee80211_is_st_prep_req - check if frame is ST Preparation Request
+ * @skb: the SKB to check
+ * Return: whether or not the frame is an ST Prep request frame
+ */
+static inline bool ieee80211_is_st_prep_req(struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *mgmt = (void *)skb->data;
+	u8 type;
+
+	if (!ieee80211_is_uhr_link_reconf_req(skb))
+		return false;
+
+	type = mgmt->u.action.uhr_link_reconf_req.type;
+
+	return type == IEEE80211_UHR_LINK_RECONFIG_REQUEST_ST_PREP;
+}
+
+/**
+ * ieee80211_is_st_exec_req - check if frame is ST Execution Request
+ * @skb: the SKB to check
+ * Return: whether or not the frame is an ST Exec request frame
+ */
+static inline bool ieee80211_is_st_exec_req(struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *mgmt = (void *)skb->data;
+	u8 type;
+
+	if (!ieee80211_is_uhr_link_reconf_req(skb))
+		return false;
+
+	type = mgmt->u.action.uhr_link_reconf_req.type;
+
+	return type == IEEE80211_UHR_LINK_RECONFIG_REQUEST_ST_EXEC;
+}
+
 #define for_each_uhr_mode_change_tuple(data, len, tuple)		\
 	for (tuple = (const void *)(data);				\
 	     (len) - ((const u8 *)tuple - (data)) >= sizeof(*tuple) &&	\
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 75d0123fbb5d..7b0f328fec79 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -4887,6 +4887,17 @@ struct mgmt_frame_regs {
 	u32 global_mcast_stypes, interface_mcast_stypes;
 };
 
+/**
+ * struct cfg80211_smd_transition_info - SMD BSS Transition info
+ *
+ * @ctx: Dynamic context to be transferred as part of ST
+ * @type: Type of ST indication
+ */
+struct cfg80211_smd_transition_info {
+	struct ieee80211_smd_ctx *ctx;
+	enum nl80211_smd_ctx_type type;
+};
+
 /**
  * struct cfg80211_ops - backend description for wireless configuration
  *
@@ -9543,6 +9554,7 @@ void cfg80211_conn_failed(struct net_device *dev, const u8 *mac_addr,
  * @flags: flags, as defined in &enum nl80211_rxmgmt_flags
  * @rx_tstamp: Hardware timestamp of frame RX in nanoseconds
  * @ack_tstamp: Hardware timestamp of ack TX in nanoseconds
+ * @st_info: SMD BSS Transition data in skb extension
  */
 struct cfg80211_rx_info {
 	int freq;
@@ -9554,6 +9566,7 @@ struct cfg80211_rx_info {
 	u32 flags;
 	u64 rx_tstamp;
 	u64 ack_tstamp;
+	struct cfg80211_smd_transition_info st_info;
 };
 
 /**
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 40ed03a775ba..156a4c0d55ac 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -3993,6 +3993,24 @@ ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
 	return RX_QUEUED;
 }
 
+static void
+ieee80211_rx_h_userspace_mgmt_st_frame(struct cfg80211_rx_info *info,
+				       struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *mgmt = (void *)info->buf;
+	struct wireless_skb_ext *ext;
+	u8 type;
+
+	type = mgmt->u.action.uhr_link_reconf_req.type;
+
+	ext = skb_ext_find(skb, SKB_EXT_WIRELESS);
+	if (!ext || ext->type != WIRELESS_SKB_EXT_UHR_SMD)
+		return;
+
+	info->st_info.type = type;
+	info->st_info.ctx = ext->uhr_smd_ctx->smd_ctx;
+}
+
 static ieee80211_rx_result debug_noinline
 ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
 {
@@ -4003,6 +4021,7 @@ ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
 		.len = rx->skb->len,
 		.link_id = rx->link_id,
 		.have_link_id = rx->link_id >= 0,
+		.st_info.ctx = NULL,
 	};
 
 	/* skip known-bad action frames and return them in the next handler */
@@ -4024,6 +4043,9 @@ ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
 	    ieee80211_is_ftm(rx->skb)) {
 		info.rx_tstamp = ktime_to_ns(skb_hwtstamps(rx->skb)->hwtstamp);
 		info.ack_tstamp = ktime_to_ns(status->ack_tx_hwtstamp);
+	} else if (ieee80211_is_st_prep_req(rx->skb) ||
+		   ieee80211_is_st_exec_req(rx->skb)) {
+		ieee80211_rx_h_userspace_mgmt_st_frame(&info, rx->skb);
 	}
 
 	if (cfg80211_rx_mgmt_ext(&rx->sdata->wdev, &info)) {

-- 
2.34.1