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, 37 insertions, 9 deletions

diff --git a/net/wireless/ap.c b/net/wireless/ap.c
index 550ac9d827fe..e68923200018 100644
--- a/net/wireless/ap.c
+++ b/net/wireless/ap.c
@@ -1,4 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0
+/*
+ * Parts of this file are
+ * Copyright (C) 2022 Intel Corporation
+ */
 #include <linux/ieee80211.h>
 #include <linux/export.h>
 #include <net/cfg80211.h>
@@ -7,8 +11,9 @@
 #include "rdev-ops.h"
 
 
-int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
-		       struct net_device *dev, bool notify)
+static int ___cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
+			       struct net_device *dev, unsigned int link_id,
+			       bool notify)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	int err;
@@ -22,15 +27,16 @@ int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
 	    dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
 		return -EOPNOTSUPP;
 
-	if (!wdev->beacon_interval)
+	if (!wdev->links[link_id].ap.beacon_interval)
 		return -ENOENT;
 
-	err = rdev_stop_ap(rdev, dev);
+	err = rdev_stop_ap(rdev, dev, link_id);
 	if (!err) {
 		wdev->conn_owner_nlportid = 0;
-		wdev->beacon_interval = 0;
-		memset(&wdev->chandef, 0, sizeof(wdev->chandef));
-		wdev->ssid_len = 0;
+		wdev->links[link_id].ap.beacon_interval = 0;
+		memset(&wdev->links[link_id].ap.chandef, 0,
+		       sizeof(wdev->links[link_id].ap.chandef));
+		wdev->u.ap.ssid_len = 0;
 		rdev_set_qos_map(rdev, dev, NULL);
 		if (notify)
 			nl80211_send_ap_stopped(wdev);
@@ -46,14 +52,36 @@ int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
 	return err;
 }
 
+int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
+		       struct net_device *dev, int link_id,
+		       bool notify)
+{
+	unsigned int link;
+	int ret = 0;
+
+	if (link_id >= 0)
+		return ___cfg80211_stop_ap(rdev, dev, link_id, notify);
+
+	for_each_valid_link(dev->ieee80211_ptr, link) {
+		int ret1 = ___cfg80211_stop_ap(rdev, dev, link, notify);
+
+		if (ret1)
+			ret = ret1;
+		/* try the next one also if one errored */
+	}
+
+	return ret;
+}
+
 int cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
-		     struct net_device *dev, bool notify)
+		     struct net_device *dev, int link_id,
+		     bool notify)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	int err;
 
 	wdev_lock(wdev);
-	err = __cfg80211_stop_ap(rdev, dev, notify);
+	err = __cfg80211_stop_ap(rdev, dev, link_id, notify);
 	wdev_unlock(wdev);
 
 	return err;