mac80211: make master netdev handling sane

Currently, almost every interface type has a 'bss' pointer
pointing to BSS information. This BSS information, however,
is for a _local_ BSS, not for the BSS we joined, so having
it on a STA mode interface makes little sense, but now they
have it pointing to the master device, which is an AP mode
virtual interface. However, except for some bitrate control
data, this pointer is only used in AP/VLAN modes (for power
saving stations.)

Overall, it is not necessary to even have the master netdev
be a valid virtual interface, and it doesn't have to be on
the list of interfaces either.

This patch changes the master netdev to be special, it now
 - no longer is on the list of virtual interfaces, which
   lets me remove a lot of tests for that
 - no longer has sub_if_data attached, since that isn't used

Additionally, this patch changes some vlan/ap mode handling
that is related to these 'bss' pointers described above (but
in the VLAN case they actually make sense because there they
point to the AP they belong to); it also adds some debugging
code to IEEE80211_DEV_TO_SUB_IF to validate it is not called
on the master netdev any more.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 13 insertions, 51 deletions

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index eeb16926aa7..f2aefd4b863 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -27,6 +27,9 @@ void ieee80211_if_sdata_init(struct ieee80211_sub_if_data *sdata)
 		skb_queue_head_init(&sdata->fragments[i].skb_list);
 
 	INIT_LIST_HEAD(&sdata->key_list);
+
+	sdata->force_unicast_rateidx = -1;
+	sdata->max_ratectrl_rateidx = -1;
 }
 
 static void ieee80211_if_sdata_deinit(struct ieee80211_sub_if_data *sdata)
@@ -38,12 +41,11 @@ static void ieee80211_if_sdata_deinit(struct ieee80211_sub_if_data *sdata)
 }
 
 /* Must be called with rtnl lock held. */
-int ieee80211_if_add(struct net_device *dev, const char *name,
+int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 		     struct net_device **new_dev, int type,
 		     struct vif_params *params)
 {
 	struct net_device *ndev;
-	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 	struct ieee80211_sub_if_data *sdata = NULL;
 	int ret;
 
@@ -67,13 +69,10 @@ int ieee80211_if_add(struct net_device *dev, const char *name,
 		goto fail;
 
 	memcpy(ndev->dev_addr, local->hw.wiphy->perm_addr, ETH_ALEN);
-	ndev->base_addr = dev->base_addr;
-	ndev->irq = dev->irq;
-	ndev->mem_start = dev->mem_start;
-	ndev->mem_end = dev->mem_end;
 	SET_NETDEV_DEV(ndev, wiphy_dev(local->hw.wiphy));
 
-	sdata = IEEE80211_DEV_TO_SUB_IF(ndev);
+	/* don't use IEEE80211_DEV_TO_SUB_IF because it checks too much */
+	sdata = netdev_priv(ndev);
 	ndev->ieee80211_ptr = &sdata->wdev;
 	sdata->wdev.wiphy = local->hw.wiphy;
 	sdata->vif.type = IEEE80211_IF_TYPE_AP;
@@ -117,14 +116,6 @@ void ieee80211_if_set_type(struct net_device *dev, int type)
 	int oldtype = sdata->vif.type;
 
 	/*
-	 * We need to call this function on the master interface
-	 * which already has a hard_start_xmit routine assigned
-	 * which must not be changed.
-	 */
-	if (dev != sdata->local->mdev)
-		dev->hard_start_xmit = ieee80211_subif_start_xmit;
-
-	/*
 	 * Called even when register_netdevice fails, it would
 	 * oops if assigned before initialising the rest.
 	 */
@@ -138,22 +129,16 @@ void ieee80211_if_set_type(struct net_device *dev, int type)
 
 	switch (type) {
 	case IEEE80211_IF_TYPE_WDS:
-		/* nothing special */
-		break;
 	case IEEE80211_IF_TYPE_VLAN:
-		sdata->u.vlan.ap = NULL;
+		/* nothing special */
 		break;
 	case IEEE80211_IF_TYPE_AP:
-		sdata->u.ap.force_unicast_rateidx = -1;
-		sdata->u.ap.max_ratectrl_rateidx = -1;
 		skb_queue_head_init(&sdata->u.ap.ps_bc_buf);
-		sdata->bss = &sdata->u.ap;
 		INIT_LIST_HEAD(&sdata->u.ap.vlans);
 		break;
 	case IEEE80211_IF_TYPE_MESH_POINT:
 	case IEEE80211_IF_TYPE_STA:
 	case IEEE80211_IF_TYPE_IBSS: {
-		struct ieee80211_sub_if_data *msdata;
 		struct ieee80211_if_sta *ifsta;
 
 		ifsta = &sdata->u.sta;
@@ -171,9 +156,6 @@ void ieee80211_if_set_type(struct net_device *dev, int type)
 		if (ieee80211_num_regular_queues(&sdata->local->hw) >= 4)
 			ifsta->flags |= IEEE80211_STA_WMM_ENABLED;
 
-		msdata = IEEE80211_DEV_TO_SUB_IF(sdata->local->mdev);
-		sdata->bss = &msdata->u.ap;
-
 		if (ieee80211_vif_is_mesh(&sdata->vif))
 			ieee80211_mesh_init_sdata(sdata);
 		break;
@@ -215,27 +197,8 @@ void ieee80211_if_reinit(struct net_device *dev)
 		WARN_ON(1);
 		break;
 	case IEEE80211_IF_TYPE_AP: {
-		/* Remove all virtual interfaces that use this BSS
-		 * as their sdata->bss */
-		struct ieee80211_sub_if_data *tsdata, *n;
 		struct beacon_data *beacon;
 
-		list_for_each_entry_safe(tsdata, n, &local->interfaces, list) {
-			if (tsdata != sdata && tsdata->bss == &sdata->u.ap) {
-				printk(KERN_DEBUG "%s: removing virtual "
-				       "interface %s because its BSS interface"
-				       " is being removed\n",
-				       sdata->dev->name, tsdata->dev->name);
-				list_del_rcu(&tsdata->list);
-				/*
-				 * We have lots of time and can afford
-				 * to sync for each interface
-				 */
-				synchronize_rcu();
-				__ieee80211_if_del(local, tsdata);
-			}
-		}
-
 		beacon = sdata->u.ap.beacon;
 		rcu_assign_pointer(sdata->u.ap.beacon, NULL);
 		synchronize_rcu();
@@ -249,6 +212,7 @@ void ieee80211_if_reinit(struct net_device *dev)
 		break;
 	}
 	case IEEE80211_IF_TYPE_WDS:
+	case IEEE80211_IF_TYPE_VLAN:
 		/* nothing to do */
 		break;
 	case IEEE80211_IF_TYPE_MESH_POINT:
@@ -269,9 +233,6 @@ void ieee80211_if_reinit(struct net_device *dev)
 	case IEEE80211_IF_TYPE_MNTR:
 		dev->type = ARPHRD_ETHER;
 		break;
-	case IEEE80211_IF_TYPE_VLAN:
-		sdata->u.vlan.ap = NULL;
-		break;
 	}
 
 	flushed = sta_info_flush(local, sdata);
@@ -289,8 +250,10 @@ void __ieee80211_if_del(struct ieee80211_local *local,
 
 	ieee80211_debugfs_remove_netdev(sdata);
 	unregister_netdevice(dev);
-	/* Except master interface, the net_device will be freed by
-	 * net_device->destructor (i. e. ieee80211_if_free). */
+	/*
+	 * The net_device will be freed by its destructor,
+	 * i.e. ieee80211_if_free.
+	 */
 }
 
 /* Must be called with rtnl lock held. */
@@ -303,8 +266,7 @@ int ieee80211_if_remove(struct net_device *dev, const char *name, int id)
 
 	list_for_each_entry_safe(sdata, n, &local->interfaces, list) {
 		if ((sdata->vif.type == id || id == -1) &&
-		    strcmp(name, sdata->dev->name) == 0 &&
-		    sdata->dev != local->mdev) {
+		    strcmp(name, sdata->dev->name) == 0) {
 			list_del_rcu(&sdata->list);
 			synchronize_rcu();
 			__ieee80211_if_del(local, sdata);