cfg80211: 802.11p OCB mode handling

This patch adds new iface type (NL80211_IFTYPE_OCB) representing
the OCB (Outside the Context of a BSS) mode.
When establishing a connection to the network a cfg80211_join_ocb
function is called (particular nl80211_command is added as well).
A mandatory parameters during the ocb_join operation are 'center
frequency' and 'channel width (5/10 MHz)'.

Changes done in mac80211 are minimal possible required to avoid
many warnings (warning: enumeration value 'NL80211_IFTYPE_OCB'
not handled in switch) during compilation. Full functionality
(where needed) is added in the following patch.

Signed-off-by: Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/wireless/ocb.c b/net/wireless/ocb.c
new file mode 100644
index 0000000..c00d4a7
--- /dev/null
+++ b/net/wireless/ocb.c
@@ -0,0 +1,88 @@
+/*
+ * OCB mode implementation
+ *
+ * Copyright: (c) 2014 Czech Technical University in Prague
+ *            (c) 2014 Volkswagen Group Research
+ * Author:    Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
+ * Funded by: Volkswagen Group Research
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/ieee80211.h>
+#include <net/cfg80211.h>
+#include "nl80211.h"
+#include "core.h"
+#include "rdev-ops.h"
+
+int __cfg80211_join_ocb(struct cfg80211_registered_device *rdev,
+			struct net_device *dev,
+			struct ocb_setup *setup)
+{
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	int err;
+
+	ASSERT_WDEV_LOCK(wdev);
+
+	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_OCB)
+		return -EOPNOTSUPP;
+
+	if (WARN_ON(!setup->chandef.chan))
+		return -EINVAL;
+
+	err = rdev_join_ocb(rdev, dev, setup);
+	if (!err)
+		wdev->chandef = setup->chandef;
+
+	return err;
+}
+
+int cfg80211_join_ocb(struct cfg80211_registered_device *rdev,
+		      struct net_device *dev,
+		      struct ocb_setup *setup)
+{
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	int err;
+
+	wdev_lock(wdev);
+	err = __cfg80211_join_ocb(rdev, dev, setup);
+	wdev_unlock(wdev);
+
+	return err;
+}
+
+int __cfg80211_leave_ocb(struct cfg80211_registered_device *rdev,
+			 struct net_device *dev)
+{
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	int err;
+
+	ASSERT_WDEV_LOCK(wdev);
+
+	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_OCB)
+		return -EOPNOTSUPP;
+
+	if (!rdev->ops->leave_ocb)
+		return -EOPNOTSUPP;
+
+	err = rdev_leave_ocb(rdev, dev);
+	if (!err)
+		memset(&wdev->chandef, 0, sizeof(wdev->chandef));
+
+	return err;
+}
+
+int cfg80211_leave_ocb(struct cfg80211_registered_device *rdev,
+		       struct net_device *dev)
+{
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	int err;
+
+	wdev_lock(wdev);
+	err = __cfg80211_leave_ocb(rdev, dev);
+	wdev_unlock(wdev);
+
+	return err;
+}