[PATCH] mac80211: revamp interface and filter configuration

Drivers are currently supposed to keep track of monitor
interfaces if they allow so-called "hard" monitor, and
they are also supposed to keep track of multicast etc.

This patch changes that, replaces the set_multicast_list()
callback with a new configure_filter() callback that takes
filter flags (FIF_*) instead of interface flags (IFF_*).
For a driver, this means it should open the filter as much
as necessary to get all frames requested by the filter flags.
Accordingly, the filter flags are named "positively", e.g.
FIF_ALLMULTI.

Multicast filtering is a bit special in that drivers that
have no multicast address filters need to allow multicast
frames through when either the FIF_ALLMULTI flag is set or
when the mc_count value is positive.

At the same time, drivers are no longer notified about
monitor interfaces at all, this means they now need to
implement the start() and stop() callbacks and the new
change_filter_flags() callback. Also, the start()/stop()
ordering changed, start() is now called *before* any
add_interface() as it really should be, and stop() after
any remove_interface().

The patch also changes the behaviour of setting the bssid
to multicast for scanning when IEEE80211_HW_NO_PROBE_FILTERING
is set; the IEEE80211_HW_NO_PROBE_FILTERING flag is removed
and the filter flag FIF_BCN_PRBRESP_PROMISC introduced.
This is a lot more efficient for hardware like b43 that
supports it and other hardware can still set the BSSID
to all-ones.

Driver modifications by Johannes Berg (b43 & iwlwifi), Michael Wu
(rtl8187, adm8211, and p54), Larry Finger (b43legacy), and
Ivo van Doorn (rt2x00).

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 141 insertions, 219 deletions

diff --git a/net/mac80211/ieee80211.c b/net/mac80211/ieee80211.c
index 57ec888..319ec2a 100644
--- a/net/mac80211/ieee80211.c
+++ b/net/mac80211/ieee80211.c
@@ -53,6 +53,38 @@ static int header_parse_80211(const struct sk_buff *skb, unsigned char *haddr)
 	return ETH_ALEN;
 }
 
+/* must be called under mdev tx lock */
+static void ieee80211_configure_filter(struct ieee80211_local *local)
+{
+	unsigned int changed_flags;
+	unsigned int new_flags = 0;
+
+	if (local->iff_promiscs)
+		new_flags |= FIF_PROMISC_IN_BSS;
+
+	if (local->iff_allmultis)
+		new_flags |= FIF_ALLMULTI;
+
+	if (local->monitors)
+		new_flags |= FIF_CONTROL |
+			     FIF_OTHER_BSS |
+			     FIF_BCN_PRBRESP_PROMISC;
+
+	changed_flags = local->filter_flags ^ new_flags;
+
+	/* be a bit nasty */
+	new_flags |= (1<<31);
+
+	local->ops->configure_filter(local_to_hw(local),
+				     changed_flags, &new_flags,
+				     local->mdev->mc_count,
+				     local->mdev->mc_list);
+
+	WARN_ON(new_flags & (1<<31));
+
+	local->filter_flags = new_flags & ~(1<<31);
+}
+
 /* master interface */
 
 static int ieee80211_master_open(struct net_device *dev)
@@ -86,6 +118,13 @@ static int ieee80211_master_stop(struct net_device *dev)
 	return 0;
 }
 
+static void ieee80211_master_set_multicast_list(struct net_device *dev)
+{
+	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+
+	ieee80211_configure_filter(local);
+}
+
 /* management interface */
 
 static void
@@ -267,49 +306,6 @@ static inline int identical_mac_addr_allowed(int type1, int type2)
 		  type2 == IEEE80211_IF_TYPE_VLAN)));
 }
 
-/* Check if running monitor interfaces should go to a "soft monitor" mode
- * and switch them if necessary. */
-static inline void ieee80211_start_soft_monitor(struct ieee80211_local *local)
-{
-	struct ieee80211_if_init_conf conf;
-
-	if (local->open_count && local->open_count == local->monitors &&
-	    !(local->hw.flags & IEEE80211_HW_MONITOR_DURING_OPER) &&
-	    local->ops->remove_interface) {
-		conf.if_id = -1;
-		conf.type = IEEE80211_IF_TYPE_MNTR;
-		conf.mac_addr = NULL;
-		local->ops->remove_interface(local_to_hw(local), &conf);
-	}
-}
-
-/* Check if running monitor interfaces should go to a "hard monitor" mode
- * and switch them if necessary. */
-static void ieee80211_start_hard_monitor(struct ieee80211_local *local)
-{
-	struct ieee80211_if_init_conf conf;
-
-	if (local->open_count && local->open_count == local->monitors &&
-	    !(local->hw.flags & IEEE80211_HW_MONITOR_DURING_OPER)) {
-		conf.if_id = -1;
-		conf.type = IEEE80211_IF_TYPE_MNTR;
-		conf.mac_addr = NULL;
-		local->ops->add_interface(local_to_hw(local), &conf);
-	}
-}
-
-static void ieee80211_if_open(struct net_device *dev)
-{
-	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-
-	switch (sdata->type) {
-	case IEEE80211_IF_TYPE_STA:
-	case IEEE80211_IF_TYPE_IBSS:
-		sdata->u.sta.flags &= ~IEEE80211_STA_PREV_BSSID_SET;
-		break;
-	}
-}
-
 static int ieee80211_open(struct net_device *dev)
 {
 	struct ieee80211_sub_if_data *sdata, *nsdata;
@@ -335,84 +331,96 @@ static int ieee80211_open(struct net_device *dev)
 	    is_zero_ether_addr(sdata->u.wds.remote_addr))
 		return -ENOLINK;
 
-	if (sdata->type == IEEE80211_IF_TYPE_MNTR && local->open_count &&
-	    !(local->hw.flags & IEEE80211_HW_MONITOR_DURING_OPER)) {
-		/* run the interface in a "soft monitor" mode */
-		local->monitors++;
-		local->open_count++;
-		local->hw.conf.flags |= IEEE80211_CONF_RADIOTAP;
-		return 0;
-	}
-	ieee80211_if_open(dev);
-	ieee80211_start_soft_monitor(local);
-
-	conf.if_id = dev->ifindex;
-	conf.type = sdata->type;
-	if (sdata->type == IEEE80211_IF_TYPE_MNTR)
-		conf.mac_addr = NULL;
-	else
-		conf.mac_addr = dev->dev_addr;
-	res = local->ops->add_interface(local_to_hw(local), &conf);
-	if (res) {
-		if (sdata->type == IEEE80211_IF_TYPE_MNTR)
-			ieee80211_start_hard_monitor(local);
-		return res;
-	}
-
 	if (local->open_count == 0) {
 		res = 0;
-		tasklet_enable(&local->tx_pending_tasklet);
-		tasklet_enable(&local->tasklet);
-		if (local->ops->open)
-			res = local->ops->open(local_to_hw(local));
-		if (res == 0) {
-			res = dev_open(local->mdev);
-			if (res) {
-				if (local->ops->stop)
-					local->ops->stop(local_to_hw(local));
-			} else {
-				res = ieee80211_hw_config(local);
-				if (res && local->ops->stop)
-					local->ops->stop(local_to_hw(local));
-				else if (!res && local->apdev)
-					dev_open(local->apdev);
-			}
-		}
-		if (res) {
-			if (local->ops->remove_interface)
-				local->ops->remove_interface(local_to_hw(local),
-							    &conf);
+		if (local->ops->start)
+			res = local->ops->start(local_to_hw(local));
+		if (res)
 			return res;
-		}
 	}
-	local->open_count++;
 
-	if (sdata->type == IEEE80211_IF_TYPE_MNTR) {
+	switch (sdata->type) {
+	case IEEE80211_IF_TYPE_MNTR:
+		/* must be before the call to ieee80211_configure_filter */
 		local->monitors++;
-		local->hw.conf.flags |= IEEE80211_CONF_RADIOTAP;
-	} else {
+		if (local->monitors == 1) {
+			netif_tx_lock_bh(local->mdev);
+			ieee80211_configure_filter(local);
+			netif_tx_unlock_bh(local->mdev);
+
+			local->hw.conf.flags |= IEEE80211_CONF_RADIOTAP;
+			ieee80211_hw_config(local);
+		}
+		break;
+	case IEEE80211_IF_TYPE_STA:
+	case IEEE80211_IF_TYPE_IBSS:
+		sdata->u.sta.flags &= ~IEEE80211_STA_PREV_BSSID_SET;
+		/* fall through */
+	default:
+		conf.if_id = dev->ifindex;
+		conf.type = sdata->type;
+		conf.mac_addr = dev->dev_addr;
+		res = local->ops->add_interface(local_to_hw(local), &conf);
+		if (res && !local->open_count && local->ops->stop)
+			local->ops->stop(local_to_hw(local));
+		if (res)
+			return res;
+
 		ieee80211_if_config(dev);
 		ieee80211_reset_erp_info(dev);
 		ieee80211_enable_keys(sdata);
+
+		if (sdata->type == IEEE80211_IF_TYPE_STA &&
+		    !local->user_space_mlme)
+			netif_carrier_off(dev);
+		else
+			netif_carrier_on(dev);
 	}
 
-	if (sdata->type == IEEE80211_IF_TYPE_STA &&
-	    !local->user_space_mlme)
-		netif_carrier_off(dev);
-	else
-		netif_carrier_on(dev);
+	if (local->open_count == 0) {
+		res = dev_open(local->mdev);
+		WARN_ON(res);
+		if (local->apdev) {
+			res = dev_open(local->apdev);
+			WARN_ON(res);
+		}
+		tasklet_enable(&local->tx_pending_tasklet);
+		tasklet_enable(&local->tasklet);
+	}
+
+	local->open_count++;
 
 	netif_start_queue(dev);
+
 	return 0;
 }
 
-static void ieee80211_if_shutdown(struct net_device *dev)
+static int ieee80211_stop(struct net_device *dev)
 {
+	struct ieee80211_sub_if_data *sdata;
 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
-	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	struct ieee80211_if_init_conf conf;
+
+	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+	netif_stop_queue(dev);
+
+	dev_mc_unsync(local->mdev, dev);
+
+	local->open_count--;
 
-	ASSERT_RTNL();
 	switch (sdata->type) {
+	case IEEE80211_IF_TYPE_MNTR:
+		local->monitors--;
+		if (local->monitors == 0) {
+			netif_tx_lock_bh(local->mdev);
+			ieee80211_configure_filter(local);
+			netif_tx_unlock_bh(local->mdev);
+
+			local->hw.conf.flags |= IEEE80211_CONF_RADIOTAP;
+			ieee80211_hw_config(local);
+		}
+		break;
 	case IEEE80211_IF_TYPE_STA:
 	case IEEE80211_IF_TYPE_IBSS:
 		sdata->u.sta.state = IEEE80211_DISABLED;
@@ -433,116 +441,61 @@ static void ieee80211_if_shutdown(struct net_device *dev)
 			cancel_delayed_work(&local->scan_work);
 		}
 		flush_workqueue(local->hw.workqueue);
-		break;
-	}
-}
-
-static int ieee80211_stop(struct net_device *dev)
-{
-	struct ieee80211_sub_if_data *sdata;
-	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
-
-	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-
-	if (sdata->type == IEEE80211_IF_TYPE_MNTR &&
-	    local->open_count > 1 &&
-	    !(local->hw.flags & IEEE80211_HW_MONITOR_DURING_OPER)) {
-		/* remove "soft monitor" interface */
-		local->open_count--;
-		local->monitors--;
-		if (!local->monitors)
-			local->hw.conf.flags &= ~IEEE80211_CONF_RADIOTAP;
-		return 0;
-	}
-
-	netif_stop_queue(dev);
-	ieee80211_if_shutdown(dev);
-
-	if (sdata->type == IEEE80211_IF_TYPE_MNTR) {
-		local->monitors--;
-		if (!local->monitors)
-			local->hw.conf.flags &= ~IEEE80211_CONF_RADIOTAP;
-	} else {
+		/* fall through */
+	default:
+		conf.if_id = dev->ifindex;
+		conf.type = sdata->type;
+		conf.mac_addr = dev->dev_addr;
 		/* disable all keys for as long as this netdev is down */
 		ieee80211_disable_keys(sdata);
+		local->ops->remove_interface(local_to_hw(local), &conf);
 	}
 
-	local->open_count--;
 	if (local->open_count == 0) {
 		if (netif_running(local->mdev))
 			dev_close(local->mdev);
+
 		if (local->apdev)
 			dev_close(local->apdev);
+
 		if (local->ops->stop)
 			local->ops->stop(local_to_hw(local));
+
 		tasklet_disable(&local->tx_pending_tasklet);
 		tasklet_disable(&local->tasklet);
 	}
-	if (local->ops->remove_interface) {
-		struct ieee80211_if_init_conf conf;
-
-		conf.if_id = dev->ifindex;
-		conf.type = sdata->type;
-		conf.mac_addr = dev->dev_addr;
-		local->ops->remove_interface(local_to_hw(local), &conf);
-	}
-
-	ieee80211_start_hard_monitor(local);
 
 	return 0;
 }
 
-enum netif_tx_lock_class {
-	TX_LOCK_NORMAL,
-	TX_LOCK_MASTER,
-};
-
-static inline void netif_tx_lock_nested(struct net_device *dev, int subclass)
-{
-	spin_lock_nested(&dev->_xmit_lock, subclass);
-	dev->xmit_lock_owner = smp_processor_id();
-}
-
 static void ieee80211_set_multicast_list(struct net_device *dev)
 {
 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-	unsigned short flags;
+	int allmulti, promisc, sdata_allmulti, sdata_promisc;
 
-	netif_tx_lock_nested(local->mdev, TX_LOCK_MASTER);
-	if (((dev->flags & IFF_ALLMULTI) != 0) ^
-	    ((sdata->flags & IEEE80211_SDATA_ALLMULTI) != 0)) {
-		if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
-			local->iff_allmultis--;
-		else
+	allmulti = !!(dev->flags & IFF_ALLMULTI);
+	promisc = !!(dev->flags & IFF_PROMISC);
+	sdata_allmulti = sdata->flags & IEEE80211_SDATA_ALLMULTI;
+	sdata_promisc = sdata->flags & IEEE80211_SDATA_PROMISC;
+
+	if (allmulti != sdata_allmulti) {
+		if (dev->flags & IFF_ALLMULTI)
 			local->iff_allmultis++;
+		else
+			local->iff_allmultis--;
 		sdata->flags ^= IEEE80211_SDATA_ALLMULTI;
 	}
-	if (((dev->flags & IFF_PROMISC) != 0) ^
-	    ((sdata->flags & IEEE80211_SDATA_PROMISC) != 0)) {
-		if (sdata->flags & IEEE80211_SDATA_PROMISC)
-			local->iff_promiscs--;
-		else
+
+	if (promisc != sdata_promisc) {
+		if (dev->flags & IFF_PROMISC)
 			local->iff_promiscs++;
+		else
+			local->iff_promiscs--;
 		sdata->flags ^= IEEE80211_SDATA_PROMISC;
 	}
-	if (dev->mc_count != sdata->mc_count) {
-		local->mc_count = local->mc_count - sdata->mc_count +
-				  dev->mc_count;
-		sdata->mc_count = dev->mc_count;
-	}
-	if (local->ops->set_multicast_list) {
-		flags = local->mdev->flags;
-		if (local->iff_allmultis)
-			flags |= IFF_ALLMULTI;
-		if (local->iff_promiscs)
-			flags |= IFF_PROMISC;
-		read_lock(&local->sub_if_lock);
-		local->ops->set_multicast_list(local_to_hw(local), flags,
-					      local->mc_count);
-		read_unlock(&local->sub_if_lock);
-	}
-	netif_tx_unlock(local->mdev);
+
+	dev_mc_sync(local->mdev, dev);
 }
 
 static const struct header_ops ieee80211_header_ops = {
@@ -612,7 +565,6 @@ static int __ieee80211_if_config(struct net_device *dev,
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 	struct ieee80211_if_conf conf;
-	static u8 scan_bssid[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 
 	if (!local->ops->config_interface || !netif_running(dev))
 		return 0;
@@ -621,11 +573,7 @@ static int __ieee80211_if_config(struct net_device *dev,
 	conf.type = sdata->type;
 	if (sdata->type == IEEE80211_IF_TYPE_STA ||
 	    sdata->type == IEEE80211_IF_TYPE_IBSS) {
-		if (local->sta_scanning &&
-		    local->scan_dev == dev)
-			conf.bssid = scan_bssid;
-		else
-			conf.bssid = sdata->u.sta.bssid;
+		conf.bssid = sdata->u.sta.bssid;
 		conf.ssid = sdata->u.sta.ssid;
 		conf.ssid_len = sdata->u.sta.ssid_len;
 		conf.generic_elem = sdata->u.sta.extra_ie;
@@ -722,37 +670,6 @@ void ieee80211_reset_erp_info(struct net_device *dev)
 					 IEEE80211_ERP_CHANGE_PREAMBLE);
 }
 
-struct dev_mc_list *ieee80211_get_mc_list_item(struct ieee80211_hw *hw,
-					       struct dev_mc_list *prev,
-					       void **ptr)
-{
-	struct ieee80211_local *local = hw_to_local(hw);
-	struct ieee80211_sub_if_data *sdata = *ptr;
-	struct dev_mc_list *mc;
-
-	if (!prev) {
-		WARN_ON(sdata);
-		sdata = NULL;
-	}
-	if (!prev || !prev->next) {
-		if (sdata)
-			sdata = list_entry(sdata->list.next,
-					   struct ieee80211_sub_if_data, list);
-		else
-			sdata = list_entry(local->sub_if_list.next,
-					   struct ieee80211_sub_if_data, list);
-		if (&sdata->list != &local->sub_if_list)
-			mc = sdata->dev->mc_list;
-		else
-			mc = NULL;
-	} else
-		mc = prev->next;
-
-	*ptr = sdata;
-	return mc;
-}
-EXPORT_SYMBOL(ieee80211_get_mc_list_item);
-
 void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
 				 struct sk_buff *skb,
 				 struct ieee80211_tx_status *status)
@@ -1158,8 +1075,12 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
 			   NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST);
 
 	BUG_ON(!ops->tx);
+	BUG_ON(!ops->start);
+	BUG_ON(!ops->stop);
 	BUG_ON(!ops->config);
 	BUG_ON(!ops->add_interface);
+	BUG_ON(!ops->remove_interface);
+	BUG_ON(!ops->configure_filter);
 	local->ops = ops;
 
 	/* for now, mdev needs sub_if_data :/ */
@@ -1206,6 +1127,7 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
 	mdev->stop = ieee80211_master_stop;
 	mdev->type = ARPHRD_IEEE80211;
 	mdev->header_ops = &ieee80211_header_ops;
+	mdev->set_multicast_list = ieee80211_master_set_multicast_list;
 
 	sdata->type = IEEE80211_IF_TYPE_AP;
 	sdata->dev = mdev;