wifi: cfg80211/mac80211: report link ID for unexpected frames

The upper layer may require the link ID to properly handle
unexpected frames. For instance, if hostapd, operating as an
AP MLD, receives a data frame from a non-associated STA,
it must send deauthentication to the link on which the STA is
operating.

Signed-off-by: Michael-CY Lee <[e-mail]>
Reviewed-by: Money Wang <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
[edit commit message]
Signed-off-by: Johannes Berg <[e-mail]>

include/net/cfg80211.h

···
 /**
  * cfg80211_rx_spurious_frame - inform userspace about a spurious frame
  * @dev: The device the frame matched to
+ * @link_id: the link the frame was received on, -1 if not applicable or unknown
  * @addr: the transmitter address
  * @gfp: context flags
  *
···
  * Return: %true if the frame was passed to userspace (or this failed
  * for a reason other than not having a subscription.)
  */
-bool cfg80211_rx_spurious_frame(struct net_device *dev,
-				const u8 *addr, gfp_t gfp);
+bool cfg80211_rx_spurious_frame(struct net_device *dev, const u8 *addr,
+				int link_id, gfp_t gfp);
 
 /**
  * cfg80211_rx_unexpected_4addr_frame - inform about unexpected WDS frame
  * @dev: The device the frame matched to
  * @addr: the transmitter address
+ * @link_id: the link the frame was received on, -1 if not applicable or unknown
  * @gfp: context flags
  *
  * This function is used in AP mode (only!) to inform userspace that
···
  * Return: %true if the frame was passed to userspace (or this failed
  * for a reason other than not having a subscription.)
  */
-bool cfg80211_rx_unexpected_4addr_frame(struct net_device *dev,
-					const u8 *addr, gfp_t gfp);
+bool cfg80211_rx_unexpected_4addr_frame(struct net_device *dev, const u8 *addr,
+					int link_id, gfp_t gfp);
 
 /**
  * cfg80211_probe_status - notify userspace about probe status

net/mac80211/rx.c

···
 		}
 
 		if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
-		    cfg80211_rx_spurious_frame(rx->sdata->dev,
-					       hdr->addr2,
-					       GFP_ATOMIC))
+		    cfg80211_rx_spurious_frame(rx->sdata->dev, hdr->addr2,
+					       rx->link_id, GFP_ATOMIC))
 			return RX_DROP_U_SPURIOUS;
 
 		return RX_DROP;
···
 			if (!test_and_set_sta_flag(sta, WLAN_STA_4ADDR_EVENT))
 				cfg80211_rx_unexpected_4addr_frame(
 					rx->sdata->dev, sta->sta.addr,
-					GFP_ATOMIC);
+					rx->link_id, GFP_ATOMIC);
 			return RX_DROP_U_UNEXPECTED_4ADDR_FRAME;
 		}
 		/*
···
 		if (rx->sta &&
 		    !test_and_set_sta_flag(rx->sta, WLAN_STA_4ADDR_EVENT))
 			cfg80211_rx_unexpected_4addr_frame(
-				rx->sdata->dev, rx->sta->sta.addr, GFP_ATOMIC);
+				rx->sdata->dev, rx->sta->sta.addr, rx->link_id,
+				GFP_ATOMIC);
 		return RX_DROP;
 	}
 

net/wireless/nl80211.c

···
 EXPORT_SYMBOL(cfg80211_conn_failed);
 
 static bool __nl80211_unexpected_frame(struct net_device *dev, u8 cmd,
-				       const u8 *addr, gfp_t gfp)
+				       const u8 *addr, int link_id, gfp_t gfp)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
···
 
 	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))
+	    nla_put(msg, NL80211_ATTR_MAC, ETH_ALEN, addr) ||
+	    (link_id >= 0 &&
+	     nla_put_u8(msg, NL80211_ATTR_MLO_LINK_ID, link_id)))
 		goto nla_put_failure;
 
 	genlmsg_end(msg, hdr);
···
 	return true;
 }
 
-bool cfg80211_rx_spurious_frame(struct net_device *dev,
-				const u8 *addr, gfp_t gfp)
+bool cfg80211_rx_spurious_frame(struct net_device *dev, const u8 *addr,
+				int link_id, gfp_t gfp)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	bool ret;
 
-	trace_cfg80211_rx_spurious_frame(dev, addr);
+	trace_cfg80211_rx_spurious_frame(dev, addr, link_id);
 
 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_AP &&
 		    wdev->iftype != NL80211_IFTYPE_P2P_GO)) {
···
 		return false;
 	}
 	ret = __nl80211_unexpected_frame(dev, NL80211_CMD_UNEXPECTED_FRAME,
-					 addr, gfp);
+					 addr, link_id, gfp);
 	trace_cfg80211_return_bool(ret);
 	return ret;
 }
 EXPORT_SYMBOL(cfg80211_rx_spurious_frame);
 
-bool cfg80211_rx_unexpected_4addr_frame(struct net_device *dev,
-					const u8 *addr, gfp_t gfp)
+bool cfg80211_rx_unexpected_4addr_frame(struct net_device *dev, const u8 *addr,
+					int link_id, gfp_t gfp)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	bool ret;
 
-	trace_cfg80211_rx_unexpected_4addr_frame(dev, addr);
+	trace_cfg80211_rx_unexpected_4addr_frame(dev, addr, link_id);
 
 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_AP &&
 		    wdev->iftype != NL80211_IFTYPE_P2P_GO &&
···
 	}
 	ret = __nl80211_unexpected_frame(dev,
 					 NL80211_CMD_UNEXPECTED_4ADDR_FRAME,
-					 addr, gfp);
+					 addr, link_id, gfp);
 	trace_cfg80211_return_bool(ret);
 	return ret;
 }

net/wireless/trace.h

···
 );
 
 DECLARE_EVENT_CLASS(cfg80211_rx_evt,
-	TP_PROTO(struct net_device *netdev, const u8 *addr),
-	TP_ARGS(netdev, addr),
+	TP_PROTO(struct net_device *netdev, const u8 *addr, int link_id),
+	TP_ARGS(netdev, addr, link_id),
 	TP_STRUCT__entry(
 		NETDEV_ENTRY
 		MAC_ENTRY(addr)
+		__field(int, link_id)
 	),
 	TP_fast_assign(
 		NETDEV_ASSIGN;
 		MAC_ASSIGN(addr, addr);
+		__entry->link_id = link_id;
 	),
-	TP_printk(NETDEV_PR_FMT ", %pM", NETDEV_PR_ARG, __entry->addr)
+	TP_printk(NETDEV_PR_FMT ", %pM, link_id:%d", NETDEV_PR_ARG,
+		  __entry->addr, __entry->link_id)
 );
 
 DEFINE_EVENT(cfg80211_rx_evt, cfg80211_rx_spurious_frame,
-	TP_PROTO(struct net_device *netdev, const u8 *addr),
-	TP_ARGS(netdev, addr)
+	TP_PROTO(struct net_device *netdev, const u8 *addr, int link_id),
+	TP_ARGS(netdev, addr, link_id)
 );
 
 DEFINE_EVENT(cfg80211_rx_evt, cfg80211_rx_unexpected_4addr_frame,
-	TP_PROTO(struct net_device *netdev, const u8 *addr),
-	TP_ARGS(netdev, addr)
+	TP_PROTO(struct net_device *netdev, const u8 *addr, int link_id),
+	TP_ARGS(netdev, addr, link_id)
 );
 
 TRACE_EVENT(cfg80211_ibss_joined,