[PATCH] softmac: do shared key auth in workqueue

Johann Uhrmann reported a bcm43xx crash and Michael Buesch tracked
it down to a problem with the new shared key auth code (recursive
calls into the driver)

This patch (effectively Michael's patch with a couple of small
modifications) solves the problem by sending the authentication
challenge response frame from a workqueue entry.

I also removed a lone \n from the bcm43xx messages relating to
authentication mode - this small change was previously discussed but
not patched in.

Signed-off-by: Daniel Drake <dsd@gentoo.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/bcm43xx/bcm43xx_main.c

@@ -3701,7 +3701,7 @@ static void bcm43xx_ieee80211_set_security(struct net_device *net_dev,
 	}
 	if (sec->flags & SEC_AUTH_MODE) {
 		secinfo->auth_mode = sec->auth_mode;
-		dprintk(", .auth_mode = %d\n", sec->auth_mode);
+		dprintk(", .auth_mode = %d", sec->auth_mode);
 	}
 	dprintk("\n");
 	if (bcm43xx_status(bcm) == BCM43xx_STAT_INITIALIZED &&

net/ieee80211/softmac/ieee80211softmac_auth.c

@@ -116,6 +116,16 @@ ieee80211softmac_auth_queue(void *data)
 	kfree(auth);
 }
 
+/* Sends a response to an auth challenge (for shared key auth). */
+static void
+ieee80211softmac_auth_challenge_response(void *_aq)
+{
+	struct ieee80211softmac_auth_queue_item *aq = _aq;
+
+	/* Send our response */
+	ieee80211softmac_send_mgt_frame(aq->mac, aq->net, IEEE80211_STYPE_AUTH, aq->state);
+}
+
 /* Handle the auth response from the AP
  * This should be registered with ieee80211 as handle_auth 
  */
@@ -197,24 +207,30 @@ ieee80211softmac_auth_resp(struct net_device *dev, struct ieee80211_auth *auth)
 		case IEEE80211SOFTMAC_AUTH_SHARED_CHALLENGE:
 			/* Check to make sure we have a challenge IE */
 			data = (u8 *)auth->info_element;
-			if(*data++ != MFIE_TYPE_CHALLENGE){
+			if (*data++ != MFIE_TYPE_CHALLENGE) {
 				printkl(KERN_NOTICE PFX "Shared Key Authentication failed due to a missing challenge.\n");
 				break;	
 			}
 			/* Save the challenge */
 			spin_lock_irqsave(&mac->lock, flags);
 			net->challenge_len = *data++; 	
-			if(net->challenge_len > WLAN_AUTH_CHALLENGE_LEN)
+			if (net->challenge_len > WLAN_AUTH_CHALLENGE_LEN)
 				net->challenge_len = WLAN_AUTH_CHALLENGE_LEN;
-			if(net->challenge != NULL)
+			if (net->challenge != NULL)
 				kfree(net->challenge);
 			net->challenge = kmalloc(net->challenge_len, GFP_ATOMIC);
 			memcpy(net->challenge, data, net->challenge_len);
 			aq->state = IEEE80211SOFTMAC_AUTH_SHARED_RESPONSE; 
-			spin_unlock_irqrestore(&mac->lock, flags);
 
-			/* Send our response */
-			ieee80211softmac_send_mgt_frame(mac, aq->net, IEEE80211_STYPE_AUTH, aq->state);
+			/* We reuse the work struct from the auth request here.
+			 * It is safe to do so as each one is per-request, and
+			 * at this point (dealing with authentication response)
+			 * we have obviously already sent the initial auth
+			 * request. */
+			cancel_delayed_work(&aq->work);
+			INIT_WORK(&aq->work, &ieee80211softmac_auth_challenge_response, (void *)aq);
+			schedule_work(&aq->work);
+			spin_unlock_irqrestore(&mac->lock, flags);
 			return 0;
 		case IEEE80211SOFTMAC_AUTH_SHARED_PASS:
 			kfree(net->challenge);