Commit a58ce43f authored by Johannes Berg's avatar Johannes Berg Committed by John W. Linville
Browse files

mac80211: avoid spurious deauth frames/messages 



With WEXT, it happens frequently that the SME
requests an authentication but then deauthenticates
right away because some new parameters came along.
Every time this happens we print a deauth message
and send a deauth frame, but both of that is rather
confusing. Avoid it by aborting the authentication
process silently, and telling cfg80211 about that.

The patch looks larger than it really is:
__cfg80211_auth_remove() is split out from
cfg80211_send_auth_timeout(), there's no new code
except __cfg80211_auth_canceled() (a one-liner) and
the mac80211 bits (7 new lines of code).

Signed-off-by: default avatarJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 7351c6bd

include/net/cfg80211.h

+12 −0
Original line number Diff line number Diff line
@@ -1838,6 +1838,18 @@ void cfg80211_send_rx_auth(struct net_device *dev, const u8 *buf, size_t len); 
 */

void cfg80211_send_auth_timeout(struct net_device *dev, const u8 *addr);



/**

 * __cfg80211_auth_canceled - notify cfg80211 that authentication was canceled

 * @dev: network device

 * @addr: The MAC address of the device with which the authentication timed out

 *

 * When a pending authentication had no action yet, the driver may decide

 * to not send a deauth frame, but in that case must calls this function

 * to tell cfg80211 about this decision. It is only valid to call this

 * function within the deauth() callback.

 */

void __cfg80211_auth_canceled(struct net_device *dev, const u8 *addr);



/**

 * cfg80211_send_rx_assoc - notification of processed association

 * @dev: network device

net/mac80211/mlme.c

+17 −0
Original line number Diff line number Diff line
@@ -2508,6 +2508,7 @@ int ieee80211_mgd_deauth(struct ieee80211_sub_if_data *sdata, 
	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

	struct ieee80211_mgd_work *wk;

	const u8 *bssid = NULL;

	bool not_auth_yet = false;



	mutex_lock(&ifmgd->mtx);
@@ -2517,12 +2518,28 @@ int ieee80211_mgd_deauth(struct ieee80211_sub_if_data *sdata, 
	} else list_for_each_entry(wk, &ifmgd->work_list, list) {

		if (&wk->bss->cbss == req->bss) {

			bssid = req->bss->bssid;

			if (wk->state == IEEE80211_MGD_STATE_PROBE)

				not_auth_yet = true;

			list_del(&wk->list);

			kfree(wk);

			break;

		}

	}



	/*

	 * If somebody requests authentication and we haven't

	 * sent out an auth frame yet there's no need to send

	 * out a deauth frame either. If the state was PROBE,

	 * then this is the case. If it's AUTH we have sent a

	 * frame, and if it's IDLE we have completed the auth

	 * process already.

	 */

	if (not_auth_yet) {

		mutex_unlock(&ifmgd->mtx);

		__cfg80211_auth_canceled(sdata->dev, bssid);

		return 0;

	}



	/*

	 * cfg80211 should catch this ... but it's racy since

	 * we can receive a deauth frame, process it, hand it

net/wireless/mlme.c

+25 −11
Original line number Diff line number Diff line
@@ -243,21 +243,12 @@ void cfg80211_send_disassoc(struct net_device *dev, const u8 *buf, size_t len) 
}

EXPORT_SYMBOL(cfg80211_send_disassoc);



void cfg80211_send_auth_timeout(struct net_device *dev, const u8 *addr)

static void __cfg80211_auth_remove(struct wireless_dev *wdev, const u8 *addr)

{

	struct wireless_dev *wdev = dev->ieee80211_ptr;

	struct wiphy *wiphy = wdev->wiphy;

	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);

	int i;

	bool done = false;



	wdev_lock(wdev);



	nl80211_send_auth_timeout(rdev, dev, addr, GFP_KERNEL);

	if (wdev->sme_state == CFG80211_SME_CONNECTING)

		__cfg80211_connect_result(dev, addr, NULL, 0, NULL, 0,

					  WLAN_STATUS_UNSPECIFIED_FAILURE,

					  false, NULL);

	ASSERT_WDEV_LOCK(wdev);



	for (i = 0; addr && i < MAX_AUTH_BSSES; i++) {

		if (wdev->authtry_bsses[i] &&
@@ -272,6 +263,29 @@ void cfg80211_send_auth_timeout(struct net_device *dev, const u8 *addr) 
	}



	WARN_ON(!done);

}



void __cfg80211_auth_canceled(struct net_device *dev, const u8 *addr)

{

	__cfg80211_auth_remove(dev->ieee80211_ptr, addr);

}

EXPORT_SYMBOL(__cfg80211_auth_canceled);



void cfg80211_send_auth_timeout(struct net_device *dev, const u8 *addr)

{

	struct wireless_dev *wdev = dev->ieee80211_ptr;

	struct wiphy *wiphy = wdev->wiphy;

	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);



	wdev_lock(wdev);



	nl80211_send_auth_timeout(rdev, dev, addr, GFP_KERNEL);

	if (wdev->sme_state == CFG80211_SME_CONNECTING)

		__cfg80211_connect_result(dev, addr, NULL, 0, NULL, 0,

					  WLAN_STATUS_UNSPECIFIED_FAILURE,

					  false, NULL);



	__cfg80211_auth_remove(wdev, addr);



	wdev_unlock(wdev);

}

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