[PATCH wireless-next v3 2/4] wifi: cfg80211/nl80211: add STA-mode peer probing

[Priyansha Tiwari <priyansha.tiwari@oss.qualcomm.com>]

From: Priyansha Tiwari <priyansha.tiwari@oss.qualcomm.com>

Add NL80211_EXT_FEATURE_PROBE_AP to allow drivers to advertise
support for probing the associated AP from STA/P2P-client mode.

Extend nl80211_probe_peer() to accept STA/P2P-client interfaces
when the driver advertises NL80211_EXT_FEATURE_PROBE_AP; in that
case the MAC attribute must be omitted (the peer is implied by
the association).

Update cfg80211_probe_status() to accept an optional peer address
and a link_id parameter (-1 for non-MLO), and include
NL80211_ATTR_MLO_LINK_ID in the event when link_id >= 0.
Update all callers.

Signed-off-by: Priyansha Tiwari <priyansha.tiwari@oss.qualcomm.com>
---
 drivers/net/wireless/ath/wil6210/cfg80211.c |  2 +-
 include/net/cfg80211.h                      | 14 +++---
 include/uapi/linux/nl80211.h                | 20 +++++---
 net/mac80211/status.c                       |  2 +-
 net/wireless/nl80211.c                      | 51 +++++++++++++++------
 5 files changed, 59 insertions(+), 30 deletions(-)

diff --git a/drivers/net/wireless/ath/wil6210/cfg80211.c b/drivers/net/wireless/ath/wil6210/cfg80211.c
index a85ff2a4316b..5f2bd9a31faf 100644
--- a/drivers/net/wireless/ath/wil6210/cfg80211.c
+++ b/drivers/net/wireless/ath/wil6210/cfg80211.c
@@ -2326,7 +2326,7 @@ static void wil_probe_client_handle(struct wil6210_priv *wil,
 	 */
 	bool alive = (sta->status == wil_sta_connected);
 
-	cfg80211_probe_status(ndev, sta->addr, req->cookie, alive,
+	cfg80211_probe_status(ndev, sta->addr, req->cookie, -1, alive,
 			      0, false, GFP_KERNEL);
 }
 
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 7f30588ff52a..9f0989f2ee12 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -5076,8 +5076,8 @@ struct mgmt_frame_regs {
  * @tdls_mgmt: Transmit a TDLS management frame.
  * @tdls_oper: Perform a high-level TDLS operation (e.g. TDLS link setup).
  *
- * @probe_peer: probe an associated client, must return a cookie that it
- *	later passes to cfg80211_probe_status().
+ * @probe_peer: probe a connected peer (AP: STA MAC required; STA: no MAC),
+ *	must return a cookie that is later passed to cfg80211_probe_status().
  *
  * @set_noack_map: Set the NoAck Map for the TIDs.
  *
@@ -9838,15 +9838,17 @@ bool cfg80211_rx_unexpected_4addr_frame(struct net_device *dev, const u8 *addr,
 /**
  * cfg80211_probe_status - notify userspace about probe status
  * @dev: the device the probe was sent on
- * @addr: the address of the peer
- * @cookie: the cookie filled in @probe_client previously
+ * @peer: The peer MAC address (or MLD address for MLO) or %NULL if not
+ * applicable (e.g. for STA/P2P-client)
+ * @cookie: the cookie filled in @probe_peer previously
+ * @link_id: The link ID on which the probe was sent (or -1 for non-MLO)
  * @acked: indicates whether probe was acked or not
  * @ack_signal: signal strength (in dBm) of the ACK frame.
  * @is_valid_ack_signal: indicates the ack_signal is valid or not.
  * @gfp: allocation flags
  */
-void cfg80211_probe_status(struct net_device *dev, const u8 *addr,
-			   u64 cookie, bool acked, s32 ack_signal,
+void cfg80211_probe_status(struct net_device *dev, const u8 *peer, u64 cookie,
+			   int link_id, bool acked, s32 ack_signal,
 			   bool is_valid_ack_signal, gfp_t gfp);
 
 /**
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index d1907dd12a80..6b8071606e6f 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -922,13 +922,15 @@
  *	and wasn't already in a 4-addr VLAN. The event will be sent similarly
  *	to the %NL80211_CMD_UNEXPECTED_FRAME event, to the same listener.
  *
- * @NL80211_CMD_PROBE_PEER: Probe an associated station on an AP interface
- *	by sending a null data frame to it and reporting when the frame is
- *	acknowledged. This is used to allow timing out inactive clients. Uses
- *	%NL80211_ATTR_IFINDEX and %NL80211_ATTR_MAC. The command returns a
- *	direct reply with an %NL80211_ATTR_COOKIE that is later used to match
- *	up the event with the request. The event includes the same data and
- *	has %NL80211_ATTR_ACK set if the frame was ACKed.
+ * @NL80211_CMD_PROBE_PEER: Probe a connected peer by sending a null data
+ *	frame and reporting when the frame is acknowledged.
+ *	In AP/GO mode, %NL80211_ATTR_MAC is required to identify the client.
+ *	In STA/P2P-client mode, %NL80211_ATTR_MAC must be omitted (the AP is
+ *	implied); the driver must advertise %NL80211_EXT_FEATURE_PROBE_AP.
+ *	The command returns a direct reply with an %NL80211_ATTR_COOKIE that
+ *	is later used to match up the event with the request. The event
+ *	includes the same data and has %NL80211_ATTR_ACK set if the frame
+ *	was ACKed.
  *
  * @NL80211_CMD_REGISTER_BEACONS: Register this socket to receive beacons from
  *	other BSSes when any interfaces are in AP mode. This helps implement
@@ -7086,6 +7088,9 @@ enum nl80211_feature_flags {
  *	LTF key seed via %NL80211_KEY_LTF_SEED. The seed is used to generate
  *	secure LTF keys for secure LTF measurement sessions.
  *
+ * @NL80211_EXT_FEATURE_PROBE_AP: Driver supports probing the associated AP
+ *	in STA mode using @NL80211_CMD_PROBE_PEER.
+ *
  * @NUM_NL80211_EXT_FEATURES: number of extended features.
  * @MAX_NL80211_EXT_FEATURES: highest extended feature index.
  */
@@ -7167,6 +7172,7 @@ enum nl80211_ext_feature_index {
 	NL80211_EXT_FEATURE_IEEE8021X_AUTH,
 	NL80211_EXT_FEATURE_ROC_ADDR_FILTER,
 	NL80211_EXT_FEATURE_SET_KEY_LTF_SEED,
+	NL80211_EXT_FEATURE_PROBE_AP,
 
 	/* add new features before the definition below */
 	NUM_NL80211_EXT_FEATURES,
diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index 8716eda8317d..1bb622d06acf 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -655,7 +655,7 @@ static void ieee80211_report_ack_skb(struct ieee80211_local *local,
 								GFP_ATOMIC);
 			else if (ieee80211_is_any_nullfunc(hdr->frame_control))
 				cfg80211_probe_status(sdata->dev, hdr->addr1,
-						      cookie, acked,
+						      cookie, -1, acked,
 						      info->status.ack_signal,
 						      is_valid_ack_signal,
 						      GFP_ATOMIC);
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 5d51dc8c09a2..4fb3b2e41963 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -16121,16 +16121,32 @@ static int nl80211_probe_peer(struct sk_buff *skb, struct genl_info *info)
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	struct sk_buff *msg;
 	void *hdr;
-	const u8 *addr;
+	const u8 *addr = NULL;
 	u64 cookie;
 	int err;
 
-	if (wdev->iftype != NL80211_IFTYPE_AP &&
-	    wdev->iftype != NL80211_IFTYPE_P2P_GO)
+	/* Allow in AP, STA, and their P2P counterparts */
+	switch (wdev->iftype) {
+	case NL80211_IFTYPE_AP:
+	case NL80211_IFTYPE_P2P_GO:
+		if (!info->attrs[NL80211_ATTR_MAC])
+			return -EINVAL;
+		addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
+		break;
+	case NL80211_IFTYPE_STATION:
+	case NL80211_IFTYPE_P2P_CLIENT:
+		if (!wiphy_ext_feature_isset(&rdev->wiphy,
+					     NL80211_EXT_FEATURE_PROBE_AP))
+			return -EOPNOTSUPP;
+		if (!wdev->connected)
+			return -ENOLINK;
+		/* STA/P2P-client probes the currently associated AP/GO. */
+		if (info->attrs[NL80211_ATTR_MAC])
+			return -EINVAL;
+		break;
+	default:
 		return -EOPNOTSUPP;
-
-	if (!info->attrs[NL80211_ATTR_MAC])
-		return -EINVAL;
+	}
 
 	if (!rdev->ops->probe_peer)
 		return -EOPNOTSUPP;
@@ -16146,7 +16162,6 @@ static int nl80211_probe_peer(struct sk_buff *skb, struct genl_info *info)
 		goto free_msg;
 	}
 
-	addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
 
 	err = rdev_probe_peer(rdev, dev, addr, &cookie);
 	if (err)
@@ -22550,8 +22565,8 @@ void cfg80211_sta_opmode_change_notify(struct net_device *dev, const u8 *mac,
 }
 EXPORT_SYMBOL(cfg80211_sta_opmode_change_notify);
 
-void cfg80211_probe_status(struct net_device *dev, const u8 *addr,
-			   u64 cookie, bool acked, s32 ack_signal,
+void cfg80211_probe_status(struct net_device *dev, const u8 *peer, u64 cookie,
+			   int link_id, bool acked, s32 ack_signal,
 			   bool is_valid_ack_signal, gfp_t gfp)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
@@ -22559,7 +22574,7 @@ void cfg80211_probe_status(struct net_device *dev, const u8 *addr,
 	struct sk_buff *msg;
 	void *hdr;
 
-	trace_cfg80211_probe_status(dev, addr, cookie, acked);
+	trace_cfg80211_probe_status(dev, peer, cookie, acked);
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
 
@@ -22574,12 +22589,18 @@ void cfg80211_probe_status(struct net_device *dev, const u8 *addr,
 
 	if (nla_put_u32(msg, NL80211_ATTR_WIPHY, rdev->wiphy_idx) ||
 	    nla_put_u32(msg, NL80211_ATTR_IFINDEX, dev->ifindex) ||
-	    nla_put(msg, NL80211_ATTR_MAC, ETH_ALEN, addr) ||
+	    (peer && nla_put(msg, NL80211_ATTR_MAC, ETH_ALEN, peer)) ||
 	    nla_put_u64_64bit(msg, NL80211_ATTR_COOKIE, cookie,
-			      NL80211_ATTR_PAD) ||
-	    (acked && nla_put_flag(msg, NL80211_ATTR_ACK)) ||
-	    (is_valid_ack_signal && nla_put_s32(msg, NL80211_ATTR_ACK_SIGNAL,
-						ack_signal)))
+			      NL80211_ATTR_PAD))
+		goto nla_put_failure;
+
+	if (link_id >= 0 &&
+	    nla_put_u8(msg, NL80211_ATTR_MLO_LINK_ID, link_id))
+		goto nla_put_failure;
+
+	if ((acked && nla_put_flag(msg, NL80211_ATTR_ACK)) ||
+	    (is_valid_ack_signal &&
+	     nla_put_s32(msg, NL80211_ATTR_ACK_SIGNAL, ack_signal)))
 		goto nla_put_failure;
 
 	genlmsg_end(msg, hdr);
-- 
2.34.1