wifi: cfg80211: support reporting failed links

For assoc and connect result APIs, support reporting
failed links; they should still come with the BSS
pointer in the case of assoc, so they're released
correctly. In the case of connect result, this is
optional.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -6933,6 +6933,8 @@ void cfg80211_auth_timeout(struct net_device *dev, const u8 *addr);
  * @ap_mld_addr: AP MLD address (in case of MLO)
  * @links: per-link information indexed by link ID, use links[0] for
  *	non-MLO connections
+ * @links.status: Set this (along with a BSS pointer) for links that
+ *	were rejected by the AP.
  */
 struct cfg80211_rx_assoc_resp {
 	const u8 *buf;
@@ -6944,6 +6946,7 @@ struct cfg80211_rx_assoc_resp {
 	struct {
 		const u8 *addr;
 		struct cfg80211_bss *bss;
+		u16 status;
 	} links[IEEE80211_MLD_MAX_NUM_LINKS];
 };
 
@@ -7454,6 +7457,9 @@ struct cfg80211_fils_resp_params {
  *	if the bss is expired during the connection, esp. for those drivers
  *	implementing connect op. Only one parameter among @bssid and @bss needs
  *	to be specified.
+ * @links.status: per-link status code, to report a status code that's not
+ *	%WLAN_STATUS_SUCCESS for a given link, it must also be in the
+ *	@valid_links bitmap and may have a BSS pointer (which is then released)
  */
 struct cfg80211_connect_resp_params {
 	int status;
@@ -7470,6 +7476,7 @@ struct cfg80211_connect_resp_params {
 		const u8 *addr;
 		const u8 *bssid;
 		struct cfg80211_bss *bss;
+		u16 status;
 	} links[IEEE80211_MLD_MAX_NUM_LINKS];
 };
 

net/wireless/mlme.c

@@ -42,6 +42,10 @@ void cfg80211_rx_assoc_resp(struct net_device *dev,
 	unsigned int link_id;
 
 	for (link_id = 0; link_id < ARRAY_SIZE(data->links); link_id++) {
+		cr.links[link_id].status = data->links[link_id].status;
+		WARN_ON_ONCE(cr.links[link_id].status != WLAN_STATUS_SUCCESS &&
+			     (!cr.ap_mld_addr || !cr.links[link_id].bss));
+
 		cr.links[link_id].bss = data->links[link_id].bss;
 		if (!cr.links[link_id].bss)
 			continue;

net/wireless/nl80211.c

@@ -17745,6 +17745,7 @@ void nl80211_send_connect_result(struct cfg80211_registered_device *rdev,
 			link_info_size += (cr->links[link].bssid ||
 					   cr->links[link].bss) ?
 					  nla_total_size(ETH_ALEN) : 0;
+			link_info_size += nla_total_size(sizeof(u16));
 		}
 	}
 
@@ -17813,7 +17814,9 @@ void nl80211_send_connect_result(struct cfg80211_registered_device *rdev,
 			     nla_put(msg, NL80211_ATTR_BSSID, ETH_ALEN, bssid)) ||
 			    (cr->links[link].addr &&
 			     nla_put(msg, NL80211_ATTR_MAC, ETH_ALEN,
-				     cr->links[link].addr)))
+				     cr->links[link].addr)) ||
+			    nla_put_u16(msg, NL80211_ATTR_STATUS_CODE,
+					cr->links[link].status))
 				goto nla_put_failure;
 
 			nla_nest_end(msg, nested_mlo_links);

net/wireless/sme.c

@@ -793,6 +793,10 @@ void __cfg80211_connect_result(struct net_device *dev,
 		}
 
 		for_each_valid_link(cr, link) {
+			/* don't do extra lookups for failures */
+			if (cr->links[link].status != WLAN_STATUS_SUCCESS)
+				continue;
+
 			if (cr->links[link].bss)
 				continue;
 
@@ -829,6 +833,16 @@ void __cfg80211_connect_result(struct net_device *dev,
 	}
 
 	memset(wdev->links, 0, sizeof(wdev->links));
+	for_each_valid_link(cr, link) {
+		if (cr->links[link].status == WLAN_STATUS_SUCCESS)
+			continue;
+		cr->valid_links &= ~BIT(link);
+		/* don't require bss pointer for failed links */
+		if (!cr->links[link].bss)
+			continue;
+		cfg80211_unhold_bss(bss_from_pub(cr->links[link].bss));
+		cfg80211_put_bss(wdev->wiphy, cr->links[link].bss);
+	}
 	wdev->valid_links = cr->valid_links;
 	for_each_valid_link(cr, link)
 		wdev->links[link].client.current_bss =