[PATCH] softmac: Fix WX and association related races

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

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 79 insertions, 58 deletions

diff --git a/net/ieee80211/softmac/ieee80211softmac_assoc.c b/net/ieee80211/softmac/ieee80211softmac_assoc.c
index 589f6d2c548a..cf51c87a971d 100644
--- a/net/ieee80211/softmac/ieee80211softmac_assoc.c
+++ b/net/ieee80211/softmac/ieee80211softmac_assoc.c
@@ -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);       
@@ -260,10 +259,8 @@ 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...
                          * Maybe we can hope to have more memory after scanning finishes ;)
@@ -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;
                 }
         }
 
@@ -297,7 +292,7 @@ ieee80211softmac_assoc_work(void *d)
         /* copy the ESSID for displaying it */
         mac->associnfo.associate_essid.len = found->essid.len;
         memcpy(mac->associnfo.associate_essid.data, found->essid.data, IW_ESSID_MAX_SIZE + 1);
-        
+
         /* we found a network! authenticate (if necessary) and associate to it. */
         if (found->authenticating) {
                 dprintk(KERN_INFO PFX "Already requested authentication, waiting...\n");
@@ -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);
         }
         
diff --git a/net/ieee80211/softmac/ieee80211softmac_io.c b/net/ieee80211/softmac/ieee80211softmac_io.c
index 82bfddbf33a2..e8419cfb058f 100644
--- a/net/ieee80211/softmac/ieee80211softmac_io.c
+++ b/net/ieee80211/softmac/ieee80211softmac_io.c
@@ -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)
-                ieee80211softmac_process_erp(mac, network->erp_value);
+        /* 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;
 }
diff --git a/net/ieee80211/softmac/ieee80211softmac_module.c b/net/ieee80211/softmac/ieee80211softmac_module.c
index addea1cf73ae..33aff4f4a471 100644
--- a/net/ieee80211/softmac/ieee80211softmac_module.c
+++ b/net/ieee80211/softmac/ieee80211softmac_module.c
@@ -57,6 +57,7 @@ struct net_device *alloc_ieee80211softmac(int sizeof_priv)
         INIT_LIST_HEAD(&softmac->network_list);
         INIT_LIST_HEAD(&softmac->events);
 
+        mutex_init(&softmac->associnfo.mutex);
         INIT_WORK(&softmac->associnfo.work, ieee80211softmac_assoc_work, softmac);
         INIT_WORK(&softmac->associnfo.timeout, ieee80211softmac_assoc_timeout, softmac);
         softmac->start_scan = ieee80211softmac_start_scan_implementation;
diff --git a/net/ieee80211/softmac/ieee80211softmac_wx.c b/net/ieee80211/softmac/ieee80211softmac_wx.c
index 2aa779d18f38..23068a830f7d 100644
--- a/net/ieee80211/softmac/ieee80211softmac_wx.c
+++ b/net/ieee80211/softmac/ieee80211softmac_wx.c
@@ -73,13 +73,14 @@ ieee80211softmac_wx_set_essid(struct net_device *net_dev,
         struct ieee80211softmac_network *n;
         struct ieee80211softmac_auth_queue_item *authptr;
         int length = 0;
-        unsigned long flags;
+
+        mutex_lock(&sm->associnfo.mutex);
 
         /* Check if we're already associating to this or another network
          * If it's another network, cancel and start over with our new network
          * If it's our network, ignore the change, we're already doing it!
          */
-        if((sm->associnfo.associating || sm->associated) &&
+        if((sm->associnfo.associating || sm->associnfo.associated) &&
            (data->essid.flags && data->essid.length)) {
                 /* Get the associating network */
                 n = ieee80211softmac_get_network_by_bssid(sm, sm->associnfo.bssid);
@@ -87,10 +88,9 @@ ieee80211softmac_wx_set_essid(struct net_device *net_dev,
                    !memcmp(n->essid.data, extra, n->essid.len)) {
                         dprintk(KERN_INFO PFX "Already associating or associated to "MAC_FMT"\n",
                                 MAC_ARG(sm->associnfo.bssid));
-                        return 0;
+                        goto out;
                 } else {
                         dprintk(KERN_INFO PFX "Canceling existing associate request!\n");
-                        spin_lock_irqsave(&sm->lock,flags);
                         /* Cancel assoc work */
                         cancel_delayed_work(&sm->associnfo.work);
                         /* We don't have to do this, but it's a little cleaner */
@@ -98,14 +98,13 @@ ieee80211softmac_wx_set_essid(struct net_device *net_dev,
                                 cancel_delayed_work(&authptr->work);
                         sm->associnfo.bssvalid = 0;
                         sm->associnfo.bssfixed = 0;
-                        spin_unlock_irqrestore(&sm->lock,flags);
                         flush_scheduled_work();
+                        sm->associnfo.associating = 0;
+                        sm->associnfo.associated = 0;
                 }
         }
 
 
-        spin_lock_irqsave(&sm->lock, flags);
-
         sm->associnfo.static_essid = 0;
         sm->associnfo.assoc_wait = 0;
 
@@ -121,10 +120,12 @@ ieee80211softmac_wx_set_essid(struct net_device *net_dev,
          * If applicable, we have already copied the data in */
         sm->associnfo.req_essid.len = length;
 
+        sm->associnfo.associating = 1;
         /* queue lower level code to do work (if necessary) */
         schedule_work(&sm->associnfo.work);
+out:
+        mutex_unlock(&sm->associnfo.mutex);
 
-        spin_unlock_irqrestore(&sm->lock, flags);
         return 0;
 }
 EXPORT_SYMBOL_GPL(ieee80211softmac_wx_set_essid);
@@ -136,10 +137,8 @@ ieee80211softmac_wx_get_essid(struct net_device *net_dev,
                               char *extra)
 {
         struct ieee80211softmac_device *sm = ieee80211_priv(net_dev);
-        unsigned long flags;
 
-        /* avoid getting inconsistent information */
-        spin_lock_irqsave(&sm->lock, flags);
+        mutex_lock(&sm->associnfo.mutex);
         /* If all fails, return ANY (empty) */
         data->essid.length = 0;
         data->essid.flags = 0;  /* active */
@@ -152,12 +151,13 @@ ieee80211softmac_wx_get_essid(struct net_device *net_dev,
         }
         
         /* If we're associating/associated, return that */
-        if (sm->associated || sm->associnfo.associating) {
+        if (sm->associnfo.associated || sm->associnfo.associating) {
                 data->essid.length = sm->associnfo.associate_essid.len;
                 data->essid.flags = 1;  /* active */
                 memcpy(extra, sm->associnfo.associate_essid.data, sm->associnfo.associate_essid.len);
         }
-        spin_unlock_irqrestore(&sm->lock, flags);
+        mutex_unlock(&sm->associnfo.mutex);
+
         return 0;
 }
 EXPORT_SYMBOL_GPL(ieee80211softmac_wx_get_essid);
@@ -322,15 +322,15 @@ ieee80211softmac_wx_get_wap(struct net_device *net_dev,
 {
         struct ieee80211softmac_device *mac = ieee80211_priv(net_dev);
         int err = 0;
-        unsigned long flags;
 
-        spin_lock_irqsave(&mac->lock, flags);
+        mutex_lock(&mac->associnfo.mutex);
         if (mac->associnfo.bssvalid)
                 memcpy(data->ap_addr.sa_data, mac->associnfo.bssid, ETH_ALEN);
         else
                 memset(data->ap_addr.sa_data, 0xff, ETH_ALEN);
         data->ap_addr.sa_family = ARPHRD_ETHER;
-        spin_unlock_irqrestore(&mac->lock, flags);
+        mutex_unlock(&mac->associnfo.mutex);
+
         return err;
 }
 EXPORT_SYMBOL_GPL(ieee80211softmac_wx_get_wap);
@@ -342,28 +342,27 @@ ieee80211softmac_wx_set_wap(struct net_device *net_dev,
                             char *extra)
 {
         struct ieee80211softmac_device *mac = ieee80211_priv(net_dev);
-        unsigned long flags;
 
         /* sanity check */
         if (data->ap_addr.sa_family != ARPHRD_ETHER) {
                 return -EINVAL;
         }
 
-        spin_lock_irqsave(&mac->lock, flags);
+        mutex_lock(&mac->associnfo.mutex);
         if (is_broadcast_ether_addr(data->ap_addr.sa_data)) {
                 /* the bssid we have is not to be fixed any longer,
                  * and we should reassociate to the best AP. */
                 mac->associnfo.bssfixed = 0;
                 /* force reassociation */
                 mac->associnfo.bssvalid = 0;
-                if (mac->associated)
+                if (mac->associnfo.associated)
                         schedule_work(&mac->associnfo.work);
         } else if (is_zero_ether_addr(data->ap_addr.sa_data)) {
                 /* the bssid we have is no longer fixed */
                 mac->associnfo.bssfixed = 0;
         } else {
                 if (!memcmp(mac->associnfo.bssid, data->ap_addr.sa_data, ETH_ALEN)) {
-                        if (mac->associnfo.associating || mac->associated) {
+                        if (mac->associnfo.associating || mac->associnfo.associated) {
                         /* bssid unchanged and associated or associating - just return */
                                 goto out;
                         }
@@ -378,7 +377,8 @@ ieee80211softmac_wx_set_wap(struct net_device *net_dev,
         }
 
  out:
-        spin_unlock_irqrestore(&mac->lock, flags);
+        mutex_unlock(&mac->associnfo.mutex);
+
         return 0;
 }
 EXPORT_SYMBOL_GPL(ieee80211softmac_wx_set_wap);
@@ -394,7 +394,8 @@ ieee80211softmac_wx_set_genie(struct net_device *dev,
         int err = 0;
         char *buf;
         int i;
-        
+
+        mutex_lock(&mac->associnfo.mutex);
         spin_lock_irqsave(&mac->lock, flags);
         /* bleh. shouldn't be locked for that kmalloc... */
 
@@ -432,6 +433,8 @@ ieee80211softmac_wx_set_genie(struct net_device *dev,
 
  out:   
         spin_unlock_irqrestore(&mac->lock, flags);
+        mutex_unlock(&mac->associnfo.mutex);
+
         return err;
 }
 EXPORT_SYMBOL_GPL(ieee80211softmac_wx_set_genie);
@@ -446,7 +449,8 @@ ieee80211softmac_wx_get_genie(struct net_device *dev,
         unsigned long flags;
         int err = 0;
         int space = wrqu->data.length;
-        
+
+        mutex_lock(&mac->associnfo.mutex);
         spin_lock_irqsave(&mac->lock, flags);
         
         wrqu->data.length = 0;
@@ -459,6 +463,8 @@ ieee80211softmac_wx_get_genie(struct net_device *dev,
                         err = -E2BIG;
         }
         spin_unlock_irqrestore(&mac->lock, flags);
+        mutex_lock(&mac->associnfo.mutex);
+
         return err;
 }
 EXPORT_SYMBOL_GPL(ieee80211softmac_wx_get_genie);
@@ -473,10 +479,13 @@ ieee80211softmac_wx_set_mlme(struct net_device *dev,
         struct iw_mlme *mlme = (struct iw_mlme *)extra;
         u16 reason = cpu_to_le16(mlme->reason_code);
         struct ieee80211softmac_network *net;
+        int err = -EINVAL;
+
+        mutex_lock(&mac->associnfo.mutex);
 
         if (memcmp(mac->associnfo.bssid, mlme->addr.sa_data, ETH_ALEN)) {
                 printk(KERN_DEBUG PFX "wx_set_mlme: requested operation on net we don't use\n");
-                return -EINVAL;
+                goto out;
         }
 
         switch (mlme->cmd) {
@@ -484,14 +493,22 @@ ieee80211softmac_wx_set_mlme(struct net_device *dev,
                 net = ieee80211softmac_get_network_by_bssid_locked(mac, mlme->addr.sa_data);
                 if (!net) {
                         printk(KERN_DEBUG PFX "wx_set_mlme: we should know the net here...\n");
-                        return -EINVAL;
+                        goto out;
                 }
                 return ieee80211softmac_deauth_req(mac, net, reason);
         case IW_MLME_DISASSOC:
                 ieee80211softmac_send_disassoc_req(mac, reason);
-                return 0;
+                mac->associnfo.associated = 0;
+                mac->associnfo.associating = 0;
+                err = 0;
+                goto out;
         default:
-                return -EOPNOTSUPP;
+                err = -EOPNOTSUPP;
         }
+
+out:
+        mutex_unlock(&mac->associnfo.mutex);
+
+        return err;
 }
 EXPORT_SYMBOL_GPL(ieee80211softmac_wx_set_mlme);