cfg80211: NL80211_ATTR_SOCKET_OWNER support for CMD_CONNECT

Disconnect or deauthenticate when the owning socket is closed if this
flag is supplied to CMD_CONNECT or CMD_ASSOCIATE.  This may be used
to ensure userspace daemon doesn't leave an unmanaged connection behind.

In some situations it would be possible to account for that, to some
degree, in the deamon restart code or in the up/down scripts without
the use of this attribute.  But there will be systems where the daemon
can go away for varying periods without a warning due to local resource
management.

Signed-off-by: Andrew Zaborowski <andrew.zaborowski@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

5 files changed, 67 insertions, 1 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 158c59ecf90a..903fc419217a 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -1142,6 +1142,8 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 		     wdev->iftype == NL80211_IFTYPE_ADHOC) && !wdev->use_4addr)
 			dev->priv_flags |= IFF_DONT_BRIDGE;
 
+		INIT_WORK(&wdev->disconnect_wk, cfg80211_autodisconnect_wk);
+
 		nl80211_notify_iface(rdev, wdev, NL80211_CMD_NEW_INTERFACE);
 		break;
 	case NETDEV_GOING_DOWN:
@@ -1230,6 +1232,7 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 #ifdef CONFIG_CFG80211_WEXT
 			kzfree(wdev->wext.keys);
 #endif
+			flush_work(&wdev->disconnect_wk);
 		}
 		/*
 		 * synchronise (so that we won't find this netdev
diff --git a/net/wireless/core.h b/net/wireless/core.h
index bc8ba6e57519..ba42055a036d 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -400,6 +400,7 @@ void __cfg80211_roamed(struct wireless_dev *wdev,
 		       const u8 *resp_ie, size_t resp_ie_len);
 int cfg80211_mgd_wext_connect(struct cfg80211_registered_device *rdev,
 			      struct wireless_dev *wdev);
+void cfg80211_autodisconnect_wk(struct work_struct *work);
 
 /* SME implementation */
 void cfg80211_conn_work(struct work_struct *work);
diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index 4646cf5695b9..1c63a77aea34 100644
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -345,6 +345,11 @@ int cfg80211_mlme_deauth(struct cfg80211_registered_device *rdev,
 	     !ether_addr_equal(wdev->current_bss->pub.bssid, bssid)))
 		return 0;
 
+	if (ether_addr_equal(wdev->disconnect_bssid, bssid) ||
+	    (wdev->current_bss &&
+	     ether_addr_equal(wdev->current_bss->pub.bssid, bssid)))
+		wdev->conn_owner_nlportid = 0;
+
 	return rdev_deauth(rdev, dev, &req);
 }
 
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index fed33ec20a71..b378d0a04003 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -8050,8 +8050,17 @@ static int nl80211_associate(struct sk_buff *skb, struct genl_info *info)
 	err = nl80211_crypto_settings(rdev, info, &req.crypto, 1);
 	if (!err) {
 		wdev_lock(dev->ieee80211_ptr);
+
 		err = cfg80211_mlme_assoc(rdev, dev, chan, bssid,
 					  ssid, ssid_len, &req);
+
+		if (!err && info->attrs[NL80211_ATTR_SOCKET_OWNER]) {
+			dev->ieee80211_ptr->conn_owner_nlportid =
+				info->snd_portid;
+			memcpy(dev->ieee80211_ptr->disconnect_bssid,
+			       bssid, ETH_ALEN);
+		}
+
 		wdev_unlock(dev->ieee80211_ptr);
 	}
 
@@ -8770,11 +8779,24 @@ static int nl80211_connect(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	wdev_lock(dev->ieee80211_ptr);
+
 	err = cfg80211_connect(rdev, dev, &connect, connkeys,
 			       connect.prev_bssid);
-	wdev_unlock(dev->ieee80211_ptr);
 	if (err)
 		kzfree(connkeys);
+
+	if (!err && info->attrs[NL80211_ATTR_SOCKET_OWNER]) {
+		dev->ieee80211_ptr->conn_owner_nlportid = info->snd_portid;
+		if (connect.bssid)
+			memcpy(dev->ieee80211_ptr->disconnect_bssid,
+			       connect.bssid, ETH_ALEN);
+		else
+			memset(dev->ieee80211_ptr->disconnect_bssid,
+			       0, ETH_ALEN);
+	}
+
+	wdev_unlock(dev->ieee80211_ptr);
+
 	return err;
 }
 
@@ -14491,6 +14513,8 @@ static int nl80211_netlink_notify(struct notifier_block * nb,
 
 			if (wdev->owner_nlportid == notify->portid)
 				schedule_destroy_work = true;
+			else if (wdev->conn_owner_nlportid == notify->portid)
+				schedule_work(&wdev->disconnect_wk);
 		}
 
 		spin_lock_bh(&rdev->beacon_registrations_lock);
diff --git a/net/wireless/sme.c b/net/wireless/sme.c
index 5e0d19380302..46693913fcea 100644
--- a/net/wireless/sme.c
+++ b/net/wireless/sme.c
@@ -727,6 +727,7 @@ void __cfg80211_connect_result(struct net_device *dev, const u8 *bssid,
 		kzfree(wdev->connect_keys);
 		wdev->connect_keys = NULL;
 		wdev->ssid_len = 0;
+		wdev->conn_owner_nlportid = 0;
 		if (bss) {
 			cfg80211_unhold_bss(bss_from_pub(bss));
 			cfg80211_put_bss(wdev->wiphy, bss);
@@ -955,6 +956,7 @@ void __cfg80211_disconnected(struct net_device *dev, const u8 *ie,
 
 	wdev->current_bss = NULL;
 	wdev->ssid_len = 0;
+	wdev->conn_owner_nlportid = 0;
 
 	nl80211_send_disconnected(rdev, dev, reason, ie, ie_len, from_ap);
 
@@ -1098,6 +1100,8 @@ int cfg80211_disconnect(struct cfg80211_registered_device *rdev,
 	kzfree(wdev->connect_keys);
 	wdev->connect_keys = NULL;
 
+	wdev->conn_owner_nlportid = 0;
+
 	if (wdev->conn)
 		err = cfg80211_sme_disconnect(wdev, reason);
 	else if (!rdev->ops->disconnect)
@@ -1107,3 +1111,32 @@ int cfg80211_disconnect(struct cfg80211_registered_device *rdev,
 
 	return err;
 }
+
+/*
+ * Used to clean up after the connection / connection attempt owner socket
+ * disconnects
+ */
+void cfg80211_autodisconnect_wk(struct work_struct *work)
+{
+	struct wireless_dev *wdev =
+		container_of(work, struct wireless_dev, disconnect_wk);
+	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
+
+	wdev_lock(wdev);
+
+	if (wdev->conn_owner_nlportid) {
+		/*
+		 * Use disconnect_bssid if still connecting and ops->disconnect
+		 * not implemented.  Otherwise we can use cfg80211_disconnect.
+		 */
+		if (rdev->ops->disconnect || wdev->current_bss)
+			cfg80211_disconnect(rdev, wdev->netdev,
+					    WLAN_REASON_DEAUTH_LEAVING, true);
+		else
+			cfg80211_mlme_deauth(rdev, wdev->netdev,
+					     wdev->disconnect_bssid, NULL, 0,
+					     WLAN_REASON_DEAUTH_LEAVING, false);
+	}
+
+	wdev_unlock(wdev);
+}