wifi: cfg80211: do some rework towards MLO link APIs

In order to support multi-link operation with multiple links,
start adding some APIs. The notable addition here is to have
the link ID in a new nl80211 attribute, that will be used to
differentiate the links in many nl80211 operations.

So far, this patch adds the netlink NL80211_ATTR_MLO_LINK_ID
attribute (as well as the NL80211_ATTR_MLO_LINKS attribute)
and plugs it through the system in some places, checking the
validity etc. along with other infrastructure needed for it.

For now, I've decided to include only the over-the-air link
ID in the API. I know we discussed that we eventually need to
have to have other ways of identifying a link, but for local
AP mode and auth/assoc commands as well as set_key etc. we'll
use the OTA ID.

Also included in this patch is some refactoring of the data
structures in struct wireless_dev, splitting for the first
time the data into type dependent pieces, to make reasoning
about these things easier.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 21 insertions, 8 deletions

diff --git a/net/wireless/wext-sme.c b/net/wireless/wext-sme.c
index cd09a9042261..68f45afc352d 100644
--- a/net/wireless/wext-sme.c
+++ b/net/wireless/wext-sme.c
@@ -3,7 +3,7 @@
  * cfg80211 wext compat for managed mode.
  *
  * Copyright 2009	Johannes Berg <johannes@sipsolutions.net>
- * Copyright (C) 2009, 2020-2021 Intel Corporation.
+ * Copyright (C) 2009, 2020-2022 Intel Corporation
  */
 
 #include <linux/export.h>
@@ -124,9 +124,12 @@ int cfg80211_mgd_wext_giwfreq(struct net_device *dev,
 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
 		return -EINVAL;
 
+	if (wdev->valid_links)
+		return -EOPNOTSUPP;
+
 	wdev_lock(wdev);
-	if (wdev->current_bss)
-		chan = wdev->current_bss->pub.channel;
+	if (wdev->links[0].client.current_bss)
+		chan = wdev->links[0].client.current_bss->pub.channel;
 	else if (wdev->wext.connect.channel)
 		chan = wdev->wext.connect.channel;
 	wdev_unlock(wdev);
@@ -208,15 +211,19 @@ int cfg80211_mgd_wext_giwessid(struct net_device *dev,
 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
 		return -EINVAL;
 
+	if (wdev->valid_links)
+		return -EINVAL;
+
 	data->flags = 0;
 
 	wdev_lock(wdev);
-	if (wdev->current_bss) {
+	if (wdev->links[0].client.current_bss) {
 		const struct element *ssid_elem;
 
 		rcu_read_lock();
-		ssid_elem = ieee80211_bss_get_elem(&wdev->current_bss->pub,
-						   WLAN_EID_SSID);
+		ssid_elem = ieee80211_bss_get_elem(
+				&wdev->links[0].client.current_bss->pub,
+				WLAN_EID_SSID);
 		if (ssid_elem) {
 			data->flags = 1;
 			data->length = ssid_elem->datalen;
@@ -300,8 +307,14 @@ int cfg80211_mgd_wext_giwap(struct net_device *dev,
 	ap_addr->sa_family = ARPHRD_ETHER;
 
 	wdev_lock(wdev);
-	if (wdev->current_bss)
-		memcpy(ap_addr->sa_data, wdev->current_bss->pub.bssid, ETH_ALEN);
+	if (wdev->valid_links) {
+		wdev_unlock(wdev);
+		return -EOPNOTSUPP;
+	}
+	if (wdev->links[0].client.current_bss)
+		memcpy(ap_addr->sa_data,
+		       wdev->links[0].client.current_bss->pub.bssid,
+		       ETH_ALEN);
 	else
 		eth_zero_addr(ap_addr->sa_data);
 	wdev_unlock(wdev);