Commit 7c28ad2d authored by Michael Buesch's avatar Michael Buesch Committed by John W. Linville
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[PATCH] softmac: Fix WX and association related races 



This fixes some race conditions in the WirelessExtension
handling and association handling code.

Signed-off-by: default avatarMichael Buesch <mb@bu3sch.de>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 3693ec67

drivers/net/wireless/bcm43xx/bcm43xx_leds.c

+1 −1
Original line number Diff line number Diff line
@@ -242,7 +242,7 @@ void bcm43xx_leds_update(struct bcm43xx_private *bcm, int activity) 
			//TODO

			break;

		case BCM43xx_LED_ASSOC:

			if (bcm->softmac->associated)

			if (bcm->softmac->associnfo.associated)

				turn_on = 1;

			break;

#ifdef CONFIG_BCM43XX_DEBUG

drivers/net/wireless/bcm43xx/bcm43xx_wx.c

+1 −1
Original line number Diff line number Diff line
@@ -847,7 +847,7 @@ static struct iw_statistics *bcm43xx_get_wireless_stats(struct net_device *net_d 
	unsigned long flags;



	wstats = &bcm->stats.wstats;

	if (!mac->associated) {

	if (!mac->associnfo.associated) {

		wstats->miss.beacon = 0;

//		bcm->ieee->ieee_stats.tx_retry_limit_exceeded = 0; // FIXME: should this be cleared here?

		wstats->discard.retries = 0;

include/net/ieee80211softmac.h

+16 −19
Original line number Diff line number Diff line
@@ -63,13 +63,11 @@ struct ieee80211softmac_wpa { 


/*

 * Information about association

 *

 * Do we need a lock for this?

 * We only ever use this structure inlined

 * into our global struct. I've used its lock,

 * but maybe we need a local one here?

 */

struct ieee80211softmac_assoc_info {



	struct mutex mutex;



	/*

	 * This is the requested ESSID. It is written

	 * only by the WX handlers.
@@ -99,12 +97,13 @@ struct ieee80211softmac_assoc_info { 
	 *

	 * bssfixed is used for SIOCSIWAP.

	 */

	u8 static_essid:1,

	   short_preamble_available:1,

	   associating:1,

	   assoc_wait:1,

	   bssvalid:1,

	   bssfixed:1;

	u8 static_essid;

	u8 short_preamble_available;

	u8 associating;

	u8 associated;

	u8 assoc_wait;

	u8 bssvalid;

	u8 bssfixed;



	/* Scan retries remaining */

	int scan_retry;
@@ -230,10 +229,8 @@ struct ieee80211softmac_device { 
	/* this lock protects this structure */

	spinlock_t lock;



	/* couple of flags */

	u8 scanning:1, /* protects scanning from being done multiple times at once */

	   associated:1,

	   running:1;

	u8 running; /* SoftMAC started? */

	u8 scanning;



	struct ieee80211softmac_scaninfo *scaninfo;

	struct ieee80211softmac_assoc_info associnfo;
@@ -295,7 +292,7 @@ static inline u8 ieee80211softmac_suggest_txrate(struct ieee80211softmac_device 
{

	struct ieee80211softmac_txrates *txrates = &mac->txrates;



	if (!mac->associated)

	if (!mac->associnfo.associated)

		return txrates->mgt_mcast_rate;



	/* We are associated, sending unicast frame */

net/ieee80211/softmac/ieee80211softmac_assoc.c

+27 −29
Original line number Diff line number Diff line
@@ -48,7 +48,7 @@ ieee80211softmac_assoc(struct ieee80211softmac_device *mac, struct ieee80211soft 
	dprintk(KERN_INFO PFX "sent association request!\n");



	spin_lock_irqsave(&mac->lock, flags);

	mac->associated = 0; /* just to make sure */

	mac->associnfo.associated = 0; /* just to make sure */



	/* Set a timer for timeout */

	/* FIXME: make timeout configurable */
@@ -62,24 +62,22 @@ ieee80211softmac_assoc_timeout(void *d) 
{

	struct ieee80211softmac_device *mac = (struct ieee80211softmac_device *)d;

	struct ieee80211softmac_network *n;

	unsigned long flags;



	spin_lock_irqsave(&mac->lock, flags);

	mutex_lock(&mac->associnfo.mutex);

	/* we might race against ieee80211softmac_handle_assoc_response,

	 * so make sure only one of us does something */

	if (!mac->associnfo.associating) {

		spin_unlock_irqrestore(&mac->lock, flags);

		return;

	}

	if (!mac->associnfo.associating)

		goto out;

	mac->associnfo.associating = 0;

	mac->associnfo.bssvalid = 0;

	mac->associated = 0;

	mac->associnfo.associated = 0;



	n = ieee80211softmac_get_network_by_bssid_locked(mac, mac->associnfo.bssid);

	spin_unlock_irqrestore(&mac->lock, flags);



	dprintk(KERN_INFO PFX "assoc request timed out!\n");

	ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_TIMEOUT, n);

out:

	mutex_unlock(&mac->associnfo.mutex);

}



void
@@ -93,7 +91,7 @@ ieee80211softmac_disassoc(struct ieee80211softmac_device *mac) 


	netif_carrier_off(mac->dev);



	mac->associated = 0;

	mac->associnfo.associated = 0;

	mac->associnfo.bssvalid = 0;

	mac->associnfo.associating = 0;

	ieee80211softmac_init_bss(mac);
@@ -107,7 +105,7 @@ ieee80211softmac_send_disassoc_req(struct ieee80211softmac_device *mac, u16 reas 
{

	struct ieee80211softmac_network *found;



	if (mac->associnfo.bssvalid && mac->associated) {

	if (mac->associnfo.bssvalid && mac->associnfo.associated) {

		found = ieee80211softmac_get_network_by_bssid(mac, mac->associnfo.bssid);

		if (found)

			ieee80211softmac_send_mgt_frame(mac, found, IEEE80211_STYPE_DISASSOC, reason);
@@ -196,17 +194,18 @@ ieee80211softmac_assoc_work(void *d) 
	int bssvalid;

	unsigned long flags;



	mutex_lock(&mac->associnfo.mutex);



	if (!mac->associnfo.associating)

		goto out;



	/* ieee80211_disassoc might clear this */

	bssvalid = mac->associnfo.bssvalid;



	/* meh */

	if (mac->associated)

	if (mac->associnfo.associated)

		ieee80211softmac_send_disassoc_req(mac, WLAN_REASON_DISASSOC_STA_HAS_LEFT);



	spin_lock_irqsave(&mac->lock, flags);

	mac->associnfo.associating = 1;

	spin_unlock_irqrestore(&mac->lock, flags);



	/* try to find the requested network in our list, if we found one already */

	if (bssvalid || mac->associnfo.bssfixed)

		found = ieee80211softmac_get_network_by_bssid(mac, mac->associnfo.bssid);
@@ -260,9 +259,7 @@ ieee80211softmac_assoc_work(void *d) 


	if (!found) {

		if (mac->associnfo.scan_retry > 0) {

			spin_lock_irqsave(&mac->lock, flags);

			mac->associnfo.scan_retry--;

			spin_unlock_irqrestore(&mac->lock, flags);



			/* We know of no such network. Let's scan. 

			 * NB: this also happens if we had no memory to copy the network info...
@@ -272,19 +269,17 @@ ieee80211softmac_assoc_work(void *d) 
			ieee80211softmac_notify(mac->dev, IEEE80211SOFTMAC_EVENT_SCAN_FINISHED, ieee80211softmac_assoc_notify_scan, NULL);

			if (ieee80211softmac_start_scan(mac))

				dprintk(KERN_INFO PFX "Associate: failed to initiate scan. Is device up?\n");

			return;

			goto out;

		} else {

			spin_lock_irqsave(&mac->lock, flags);

			mac->associnfo.associating = 0;

			mac->associated = 0;

			spin_unlock_irqrestore(&mac->lock, flags);

			mac->associnfo.associated = 0;



			dprintk(KERN_INFO PFX "Unable to find matching network after scan!\n");

			/* reset the retry counter for the next user request since we

			 * break out and don't reschedule ourselves after this point. */

			mac->associnfo.scan_retry = IEEE80211SOFTMAC_ASSOC_SCAN_RETRY_LIMIT;

			ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_NET_NOT_FOUND, NULL);

			return;

			goto out;

		}

	}
@@ -305,7 +300,7 @@ ieee80211softmac_assoc_work(void *d) 
			mac->associnfo.assoc_wait = 1;

			ieee80211softmac_notify_internal(mac, IEEE80211SOFTMAC_EVENT_ANY, found, ieee80211softmac_assoc_notify_auth, NULL, GFP_KERNEL);

		}

		return;

		goto out;

	}

	if (!found->authenticated && !found->authenticating) {

		/* This relies on the fact that _auth_req only queues the work,
@@ -321,11 +316,14 @@ ieee80211softmac_assoc_work(void *d) 
			mac->associnfo.assoc_wait = 0;

			ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_FAILED, found);

		}

		return;

		goto out;

	}

	/* finally! now we can start associating */

	mac->associnfo.assoc_wait = 0;

	ieee80211softmac_assoc(mac, found);



out:

	mutex_unlock(&mac->associnfo.mutex);

}



/* call this to do whatever is necessary when we're associated */
@@ -341,7 +339,7 @@ ieee80211softmac_associated(struct ieee80211softmac_device *mac, 
	mac->bssinfo.supported_rates = net->supported_rates;

	ieee80211softmac_recalc_txrates(mac);



	mac->associated = 1;

	mac->associnfo.associated = 1;



	mac->associnfo.short_preamble_available =

		(cap & WLAN_CAPABILITY_SHORT_PREAMBLE) != 0;
@@ -421,7 +419,7 @@ ieee80211softmac_handle_assoc_response(struct net_device * dev, 
			dprintk(KERN_INFO PFX "associating failed (reason: 0x%x)!\n", status);

			mac->associnfo.associating = 0;

			mac->associnfo.bssvalid = 0;

			mac->associated = 0;

			mac->associnfo.associated = 0;

			ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_FAILED, network);

	}

net/ieee80211/softmac/ieee80211softmac_io.c

+7 −2
Original line number Diff line number Diff line
@@ -475,8 +475,13 @@ int ieee80211softmac_handle_beacon(struct net_device *dev, 
{

	struct ieee80211softmac_device *mac = ieee80211_priv(dev);



	if (mac->associated && memcmp(network->bssid, mac->associnfo.bssid, ETH_ALEN) == 0)

	/* This might race, but we don't really care and it's not worth

	 * adding heavyweight locking in this fastpath.

	 */

	if (mac->associnfo.associated) {

		if (memcmp(network->bssid, mac->associnfo.bssid, ETH_ALEN) == 0)

			ieee80211softmac_process_erp(mac, network->erp_value);

	}



	return 0;

}