diff mbox

[PATCHv4] mac80211: Fix circular locking dependency in ARP filter handling

Message ID 1276080206-29562-1-git-send-email-juuso.oikarinen@nokia.com (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Juuso Oikarinen June 9, 2010, 10:43 a.m. UTC
None
diff mbox

Patch

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index e3c1d47..09c4c89 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -19,7 +19,6 @@ 
 #include <linux/wireless.h>
 #include <linux/device.h>
 #include <linux/ieee80211.h>
-#include <linux/inetdevice.h>
 #include <net/cfg80211.h>
 
 /**
@@ -147,6 +146,7 @@  struct ieee80211_low_level_stats {
  *	enabled/disabled (beaconing modes)
  * @BSS_CHANGED_CQM: Connection quality monitor config changed
  * @BSS_CHANGED_IBSS: IBSS join status changed
+ * @BSS_CHANGED_ARP_FILTER: Hardware ARP filter address list or state changed.
  */
 enum ieee80211_bss_change {
 	BSS_CHANGED_ASSOC		= 1<<0,
@@ -161,10 +161,18 @@  enum ieee80211_bss_change {
 	BSS_CHANGED_BEACON_ENABLED	= 1<<9,
 	BSS_CHANGED_CQM			= 1<<10,
 	BSS_CHANGED_IBSS		= 1<<11,
+	BSS_CHANGED_ARP_FILTER		= 1<<12,
 
 	/* when adding here, make sure to change ieee80211_reconfig */
 };
 
+/*
+ * The maximum number of IPv4 addresses listed for ARP filtering. If the number
+ * of addresses for an interface increase beyond this value, hardware ARP
+ * filtering will be disabled.
+ */
+#define IEEE80211_BSS_ARP_ADDR_LIST_LEN 4
+
 /**
  * struct ieee80211_bss_conf - holds the BSS's changing parameters
  *
@@ -200,6 +208,15 @@  enum ieee80211_bss_change {
  * @cqm_rssi_thold: Connection quality monitor RSSI threshold, a zero value
  *	implies disabled
  * @cqm_rssi_hyst: Connection quality monitor RSSI hysteresis
+ * @arp_addr_list: List of IPv4 addresses for hardware ARP filtering. The
+ *	may filter ARP queries targeted for other addresses than listed here.
+ *	The driver must allow ARP queries targeted for all address listed here
+ *	to pass through. An empty list implies no ARP queries need to pass.
+ * @arp_addr_cnt: Number of addresses currently on the list.
+ * @arp_filter_enabled: Enable ARP filtering - if enabled, the hardware may
+ *	filter ARP queries based on the @arp_addr_list, if disabled, the
+ *	hardware must not perform any ARP filtering. Note, that the filter will
+ *	be enabled also in promiscuous mode.
  */
 struct ieee80211_bss_conf {
 	const u8 *bssid;
@@ -220,6 +237,9 @@  struct ieee80211_bss_conf {
 	s32 cqm_rssi_thold;
 	u32 cqm_rssi_hyst;
 	enum nl80211_channel_type channel_type;
+	__be32 arp_addr_list[IEEE80211_BSS_ARP_ADDR_LIST_LEN];
+	u8 arp_addr_cnt;
+	bool arp_filter_enabled;
 };
 
 /**
@@ -1529,16 +1549,6 @@  enum ieee80211_ampdu_mlme_action {
  *	of the bss parameters has changed when a call is made. The callback
  *	can sleep.
  *
- * @configure_arp_filter: Configuration function for hardware ARP query filter.
- *	This function is called with all the IP addresses configured to the
- *	interface as argument - all ARP queries targeted to any of these
- *	addresses must pass through. If the hardware filter does not support
- *	enought addresses, hardware filtering must be disabled. The ifa_list
- *	argument may be NULL, indicating that filtering must be disabled.
- *	This function is called upon association complete with current
- *	address(es), and while associated whenever the IP address(es) change.
- *	The callback can sleep.
- *
  * @prepare_multicast: Prepare for multicast filter configuration.
  *	This callback is optional, and its return value is passed
  *	to configure_filter(). This callback must be atomic.
@@ -1678,9 +1688,6 @@  struct ieee80211_ops {
 				 struct ieee80211_vif *vif,
 				 struct ieee80211_bss_conf *info,
 				 u32 changed);
-	int (*configure_arp_filter)(struct ieee80211_hw *hw,
-				    struct ieee80211_vif *vif,
-				    struct in_ifaddr *ifa_list);
 	u64 (*prepare_multicast)(struct ieee80211_hw *hw,
 				 struct netdev_hw_addr_list *mc_list);
 	void (*configure_filter)(struct ieee80211_hw *hw,
diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index d1139e4..bbea3bc 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -83,23 +83,6 @@  static inline void drv_bss_info_changed(struct ieee80211_local *local,
 	trace_drv_bss_info_changed(local, sdata, info, changed);
 }
 
-struct in_ifaddr;
-static inline int drv_configure_arp_filter(struct ieee80211_local *local,
-					   struct ieee80211_vif *vif,
-					   struct in_ifaddr *ifa_list)
-{
-	int ret = 0;
-
-	might_sleep();
-
-	if (local->ops->configure_arp_filter)
-		ret = local->ops->configure_arp_filter(&local->hw, vif,
-						       ifa_list);
-
-	trace_drv_configure_arp_filter(local, vif_to_sdata(vif), ifa_list, ret);
-	return ret;
-}
-
 static inline u64 drv_prepare_multicast(struct ieee80211_local *local,
 					struct netdev_hw_addr_list *mc_list)
 {
diff --git a/net/mac80211/driver-trace.h b/net/mac80211/driver-trace.h
index 6b90630..1e293df 100644
--- a/net/mac80211/driver-trace.h
+++ b/net/mac80211/driver-trace.h
@@ -219,31 +219,6 @@  TRACE_EVENT(drv_bss_info_changed,
 	)
 );
 
-TRACE_EVENT(drv_configure_arp_filter,
-	TP_PROTO(struct ieee80211_local *local,
-		 struct ieee80211_sub_if_data *sdata,
-		 struct in_ifaddr *ifa_list, int ret),
-
-	TP_ARGS(local, sdata, ifa_list, ret),
-
-	TP_STRUCT__entry(
-		LOCAL_ENTRY
-		VIF_ENTRY
-		__field(int, ret)
-	),
-
-	TP_fast_assign(
-		LOCAL_ASSIGN;
-		VIF_ASSIGN;
-		__entry->ret = ret;
-	),
-
-	TP_printk(
-		VIF_PR_FMT LOCAL_PR_FMT " ret:%d",
-		VIF_PR_ARG, LOCAL_PR_ARG, __entry->ret
-	)
-);
-
 TRACE_EVENT(drv_prepare_multicast,
 	TP_PROTO(struct ieee80211_local *local, int mc_count, u64 ret),
 
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 4d3883e..79e366e 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -517,6 +517,8 @@  struct ieee80211_sub_if_data {
 
 	u16 sequence_number;
 
+	bool arp_filter_state;
+
 	/*
 	 * AP this belongs to: self in AP mode and
 	 * corresponding AP in VLAN mode, NULL for
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 1afa9ec..1f5476d 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -959,6 +959,9 @@  int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 	sdata->wdev.wiphy = local->hw.wiphy;
 	sdata->local = local;
 	sdata->dev = ndev;
+#ifdef CONFIG_INET
+	sdata->arp_filter_state = true;
+#endif
 
 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
 		skb_queue_head_init(&sdata->fragments[i].skb_list);
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 5706156..f5fe025 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -20,6 +20,7 @@ 
 #include <linux/rtnetlink.h>
 #include <linux/bitmap.h>
 #include <linux/pm_qos_params.h>
+#include <linux/inetdevice.h>
 #include <net/net_namespace.h>
 #include <net/cfg80211.h>
 
@@ -330,23 +331,6 @@  static void ieee80211_recalc_smps_work(struct work_struct *work)
 }
 
 #ifdef CONFIG_INET
-int ieee80211_set_arp_filter(struct ieee80211_sub_if_data *sdata)
-{
-	struct in_device *idev;
-	int ret = 0;
-
-	BUG_ON(!sdata);
-	ASSERT_RTNL();
-
-	idev = sdata->dev->ip_ptr;
-	if (!idev)
-		return 0;
-
-	ret = drv_configure_arp_filter(sdata->local, &sdata->vif,
-				       idev->ifa_list);
-	return ret;
-}
-
 static int ieee80211_ifa_changed(struct notifier_block *nb,
 				 unsigned long data, void *arg)
 {
@@ -356,8 +340,11 @@  static int ieee80211_ifa_changed(struct notifier_block *nb,
 			     ifa_notifier);
 	struct net_device *ndev = ifa->ifa_dev->dev;
 	struct wireless_dev *wdev = ndev->ieee80211_ptr;
+	struct in_device *idev;
 	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_bss_conf *bss_conf;
 	struct ieee80211_if_managed *ifmgd;
+	int c = 0;
 
 	/* Make sure it's our interface that got changed */
 	if (!wdev)
@@ -366,17 +353,44 @@  static int ieee80211_ifa_changed(struct notifier_block *nb,
 	if (wdev->wiphy != local->hw.wiphy)
 		return NOTIFY_DONE;
 
-	/* We are concerned about IP addresses only when associated */
 	sdata = IEEE80211_DEV_TO_SUB_IF(ndev);
+	bss_conf = &sdata->vif.bss_conf;
 
 	/* ARP filtering is only supported in managed mode */
 	if (sdata->vif.type != NL80211_IFTYPE_STATION)
 		return NOTIFY_DONE;
 
+	idev = sdata->dev->ip_ptr;
+	if (!idev)
+		return NOTIFY_DONE;
+
 	ifmgd = &sdata->u.mgd;
 	mutex_lock(&ifmgd->mtx);
-	if (ifmgd->associated)
-		ieee80211_set_arp_filter(sdata);
+
+	/* Copy the addresses to the bss_conf list */
+	ifa = idev->ifa_list;
+	while (c < IEEE80211_BSS_ARP_ADDR_LIST_LEN && ifa) {
+		bss_conf->arp_addr_list[c] = ifa->ifa_address;
+		ifa = ifa->ifa_next;
+		c++;
+	}
+
+	/* If not all addresses fit the list, disable filtering */
+	if (ifa) {
+		sdata->arp_filter_state = false;
+		c = 0;
+	} else {
+		sdata->arp_filter_state = true;
+	}
+	bss_conf->arp_addr_cnt = c;
+
+	/* Configure driver only if associated */
+	if (ifmgd->associated) {
+		bss_conf->arp_filter_enabled = sdata->arp_filter_state;
+		ieee80211_bss_info_change_notify(sdata,
+						 BSS_CHANGED_ARP_FILTER);
+	}
+
 	mutex_unlock(&ifmgd->mtx);
 
 	return NOTIFY_DONE;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index ac68c41..5740ce1 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -806,11 +806,12 @@  static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
 {
 	struct ieee80211_bss *bss = (void *)cbss->priv;
 	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
 
 	bss_info_changed |= BSS_CHANGED_ASSOC;
 	/* set timing information */
-	sdata->vif.bss_conf.beacon_int = cbss->beacon_interval;
-	sdata->vif.bss_conf.timestamp = cbss->tsf;
+	bss_conf->beacon_int = cbss->beacon_interval;
+	bss_conf->timestamp = cbss->tsf;
 
 	bss_info_changed |= BSS_CHANGED_BEACON_INT;
 	bss_info_changed |= ieee80211_handle_bss_capability(sdata,
@@ -835,7 +836,7 @@  static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
 
 	ieee80211_led_assoc(local, 1);
 
-	sdata->vif.bss_conf.assoc = 1;
+	bss_conf->assoc = 1;
 	/*
 	 * For now just always ask the driver to update the basic rateset
 	 * when we have associated, we aren't checking whether it actually
@@ -848,9 +849,15 @@  static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
 
 	/* Tell the driver to monitor connection quality (if supported) */
 	if ((local->hw.flags & IEEE80211_HW_SUPPORTS_CQM_RSSI) &&
-	    sdata->vif.bss_conf.cqm_rssi_thold)
+	    bss_conf->cqm_rssi_thold)
 		bss_info_changed |= BSS_CHANGED_CQM;
 
+	/* Enable ARP filtering */
+	if (bss_conf->arp_filter_enabled != sdata->arp_filter_state) {
+		bss_conf->arp_filter_enabled = sdata->arp_filter_state;
+		bss_info_changed |= BSS_CHANGED_ARP_FILTER;
+	}
+
 	ieee80211_bss_info_change_notify(sdata, bss_info_changed);
 
 	mutex_lock(&local->iflist_mtx);
@@ -932,6 +939,12 @@  static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
 
 	ieee80211_hw_config(local, config_changed);
 
+	/* Disable ARP filtering */
+	if (sdata->vif.bss_conf.arp_filter_enabled) {
+		sdata->vif.bss_conf.arp_filter_enabled = false;
+		changed |= BSS_CHANGED_ARP_FILTER;
+	}
+
 	/* The BSSID (not really interesting) and HT changed */
 	changed |= BSS_CHANGED_BSSID | BSS_CHANGED_HT;
 	ieee80211_bss_info_change_notify(sdata, changed);
@@ -2116,19 +2129,9 @@  static enum work_done_result ieee80211_assoc_done(struct ieee80211_work *wk,
 			cfg80211_send_assoc_timeout(wk->sdata->dev,
 						    wk->filter_ta);
 			return WORK_DONE_DESTROY;
-#ifdef CONFIG_INET
-		} else {
-			mutex_unlock(&wk->sdata->u.mgd.mtx);
-
-			/*
-			 * configure ARP filter IP addresses to the driver,
-			 * intentionally outside the mgd mutex.
-			 */
-			rtnl_lock();
-			ieee80211_set_arp_filter(wk->sdata);
-			rtnl_unlock();
-#endif
 		}
+
+		mutex_unlock(&wk->sdata->u.mgd.mtx);
 	}
 
 	cfg80211_send_rx_assoc(wk->sdata->dev, skb->data, skb->len);