freewtp/openwrt/mac80211_patches/922-mac80211_packet_tunnel-linux-4.4.patch

From abc84789bd6d42fdbfe598d72177ed41d54c7bcf Mon Sep 17 00:00:00 2001
From: Andreas Schultz <aschultz@tpip.net>
Date: Thu, 4 Feb 2016 15:57:11 +0100
Subject: [PATCH] support patch for FreeWTP

Allows for kernel side interception and injection of IEEE 802.11 frames.
---
 include/net/mac80211.h     |  31 +++++
 net/mac80211/Kconfig       |   7 ++
 net/mac80211/ieee80211_i.h |  12 ++
 net/mac80211/iface.c       |  63 ++++++++++
 net/mac80211/rx.c          |  92 +++++++++++++--
 net/mac80211/tx.c          | 286 +++++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 479 insertions(+), 12 deletions(-)

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 760bc4d..bf60d9d 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -2199,6 +2199,37 @@ ieee80211_get_alt_retry_rate(const struct ieee80211_hw *hw,
  */
 void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb);
 
+#ifdef CONFIG_MAC80211_CAPWAP_WTP
+
+extern struct static_key mac80211_capwap_wtp;
+
+/**
+ *
+ */
+struct ieee80211_pcktunnel {
+	u16 subtype_mask[3];		/* 0: MGMT, 1: CTLR, 2: DATA */
+
+	int (*handler)(u32 ifindex, struct sk_buff *skb, int sig_dbm, unsigned char rate, void *data);
+	void *data;
+};
+
+/**
+ *
+ */
+int ieee80211_pcktunnel_register(struct net_device *dev, struct ieee80211_pcktunnel *handler);
+
+/**
+ *
+ */
+int ieee80211_pcktunnel_deregister(struct net_device *dev, struct ieee80211_pcktunnel *handler);
+
+/**
+ *
+ */
+netdev_tx_t ieee80211_inject_xmit(struct sk_buff* skb, struct net_device* dev);
+
+#endif
+
 /**
  * DOC: Hardware crypto acceleration
  *
diff --git a/net/mac80211/Kconfig b/net/mac80211/Kconfig
index 3891cbd..4ff4461 100644
--- a/net/mac80211/Kconfig
+++ b/net/mac80211/Kconfig
@@ -318,3 +318,10 @@ config MAC80211_STA_HASH_MAX_SIZE
 	  connect more stations than the number selected here.)
 
 	  If unsure, leave the default of 0.
+
+config MAC80211_CAPWAP_WTP
+	bool "Enable support functions for out-of-tree CAPWAP WTP module"
+	depends on MAC80211
+	---help---
+	  Select this to build support hooks for out-of-tree CAPWAP FreeWTP
+	  module.
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 6837a46..e96cbff 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -180,6 +180,9 @@ typedef unsigned __bitwise__ ieee80211_rx_result;
 #define RX_DROP_UNUSABLE	((__force ieee80211_rx_result) 1u)
 #define RX_DROP_MONITOR		((__force ieee80211_rx_result) 2u)
 #define RX_QUEUED		((__force ieee80211_rx_result) 3u)
+#ifdef CONFIG_MAC80211_CAPWAP_WTP
+#define RX_IGNORE_MONITOR	((__force ieee80211_rx_result) 4u)
+#endif
 
 /**
  * enum ieee80211_packet_rx_flags - packet RX flags
@@ -835,6 +838,11 @@ struct ieee80211_sub_if_data {
 
 	char name[IFNAMSIZ];
 
+#ifdef CONFIG_MAC80211_CAPWAP_WTP
+	/* Packet tunnel handlers */
+	struct ieee80211_pcktunnel __rcu *pcktunnel_handlers;
+#endif
+
 	/* Fragment table for host-based reassembly */
 	struct ieee80211_fragment_entry	fragments[IEEE80211_FRAGMENT_MAX];
 	unsigned int fragment_next;
@@ -1632,6 +1640,10 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 void __ieee80211_subif_start_xmit(struct sk_buff *skb,
 				  struct net_device *dev,
 				  u32 info_flags);
+#ifdef CONFIG_MAC80211_CAPWAP_WTP
+netdev_tx_t ieee80211_capwap_subif_start_xmit(struct sk_buff *skb,
+					      struct net_device *dev);
+#endif
 void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
 			      struct sk_buff_head *skbs);
 struct sk_buff *
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index bcb0a1b..8e2069f 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -1955,3 +1955,66 @@ void ieee80211_iface_exit(void)
 {
 	unregister_netdevice_notifier(&mac80211_netdev_notifier);
 }
+
+#ifdef CONFIG_MAC80211_CAPWAP_WTP
+
+struct static_key mac80211_capwap_wtp __read_mostly;
+
+static const struct net_device_ops ieee80211_capwapif_ops = {
+	.ndo_open		= ieee80211_open,
+	.ndo_stop		= ieee80211_stop,
+	.ndo_uninit		= ieee80211_uninit,
+	.ndo_start_xmit		= ieee80211_capwap_subif_start_xmit,
+	.ndo_set_rx_mode	= ieee80211_set_multicast_list,
+	.ndo_change_mtu 	= ieee80211_change_mtu,
+	.ndo_set_mac_address 	= ieee80211_change_mac,
+	.ndo_select_queue	= ieee80211_netdev_select_queue,
+	.ndo_get_stats64	= ieee80211_get_stats64,
+};
+
+int ieee80211_pcktunnel_register(struct net_device *dev, struct ieee80211_pcktunnel *handler)
+{
+	int ret = 0;
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+	dev->netdev_ops = &ieee80211_capwapif_ops;
+
+	mutex_lock(&sdata->local->iflist_mtx);
+
+	if (rcu_dereference_protected(sdata->pcktunnel_handlers, lockdep_is_held(&sdata->local->iflist_mtx))) {
+		ret = -EBUSY;
+	} else {
+		rcu_assign_pointer(sdata->pcktunnel_handlers, handler);
+		static_key_slow_inc(&mac80211_capwap_wtp);
+	}
+
+	mutex_unlock(&sdata->local->iflist_mtx);
+	synchronize_net();
+
+	return ret;
+}
+EXPORT_SYMBOL(ieee80211_pcktunnel_register);
+
+int ieee80211_pcktunnel_deregister(struct net_device *dev, struct ieee80211_pcktunnel *handler)
+{
+	int ret = -ENODEV;
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	struct ieee80211_pcktunnel *h;
+
+	mutex_lock(&sdata->local->iflist_mtx);
+
+	h = rcu_dereference_protected(sdata->pcktunnel_handlers, lockdep_is_held(&sdata->local->iflist_mtx));
+	if (h == handler) {
+		ret = 0;
+		static_key_slow_dec(&mac80211_capwap_wtp);
+		rcu_assign_pointer(sdata->pcktunnel_handlers, NULL);
+	}
+
+	mutex_unlock(&sdata->local->iflist_mtx);
+	synchronize_net();
+
+	return ret;
+}
+EXPORT_SYMBOL(ieee80211_pcktunnel_deregister);
+
+#endif
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index a3bb8f7..cbe0642 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -3058,6 +3058,56 @@ ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
 	return RX_QUEUED;
 }
 
+#ifdef CONFIG_MAC80211_CAPWAP_WTP
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_pcktunnel(struct ieee80211_rx_data *rx, struct ieee80211_rate *rate)
+{
+	struct ieee80211_pcktunnel *handler;
+
+	handler = rcu_dereference(rx->sdata->pcktunnel_handlers);
+	if (handler) {
+		u16 fc;
+		u16 fc_type;
+		int sig_dbm = 0;
+		unsigned char pckrate = 0;
+		struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
+		struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
+
+		if (ieee80211_hw_check(&rx->local->hw, SIGNAL_DBM))
+			sig_dbm = status->signal;
+
+		if (rate && !(status->flag & (RX_FLAG_HT | RX_FLAG_VHT))) {
+			int shift = 0;
+			if (status->flag & RX_FLAG_10MHZ)
+				shift = 1;
+			else if (status->flag & RX_FLAG_5MHZ)
+				shift = 2;
+			pckrate = DIV_ROUND_UP(rate->bitrate, 5 * (1 << shift));
+		}
+
+		/* Retrieve type and subtype packet */
+		fc = le16_to_cpu(hdr->frame_control);
+		fc_type = ((fc & IEEE80211_FCTL_FTYPE) >> 2);
+		if (fc_type < 3) {
+			u16 bitmask = 1 << ((fc & IEEE80211_FCTL_STYPE) >> 4);
+
+			/* Delegate packet to external handler */
+			if (handler->subtype_mask[fc_type] & bitmask) {
+				if (handler->handler(rx->sdata->dev->ifindex, rx->skb, sig_dbm, pckrate, handler->data)) {
+					return RX_IGNORE_MONITOR;
+				}
+			}
+		}
+	}
+
+	return RX_CONTINUE;
+}
+
+/* TODO: use IEEE80211_RX_FRAGMENTED */
+
+#endif
+
 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
 					struct ieee80211_rate *rate)
 {
@@ -3137,6 +3187,9 @@ static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
 		if (rx->sta)
 			rx->sta->rx_stats.dropped++;
 		/* fall through */
+#ifdef CONFIG_MAC80211_CAPWAP_WTP
+	case RX_IGNORE_MONITOR:
+#endif
 	case RX_CONTINUE: {
 		struct ieee80211_rate *rate = NULL;
 		struct ieee80211_supported_band *sband;
@@ -3165,7 +3218,9 @@ static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
 }
 
 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
-				  struct sk_buff_head *frames)
+				  struct sk_buff_head *frames,
+				  struct ieee80211_rate *rate)
+
 {
 	ieee80211_rx_result res = RX_DROP_MONITOR;
 	struct sk_buff *skb;
@@ -3204,6 +3259,15 @@ static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
 		if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 			CALL_RXH(ieee80211_rx_h_mesh_fwding);
 #endif
+#ifdef CONFIG_MAC80211_CAPWAP_WTP
+		if (static_key_false(&mac80211_capwap_wtp)) {
+			/* special treatment */
+			res = ieee80211_rx_h_pcktunnel(rx, rate);
+			if (res != RX_CONTINUE)
+				goto rxh_next;
+		}
+#endif
+
 		CALL_RXH(ieee80211_rx_h_amsdu)
 		CALL_RXH(ieee80211_rx_h_data)
 
@@ -3227,7 +3291,8 @@ static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
 	spin_unlock_bh(&rx->local->rx_path_lock);
 }
 
-static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
+static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx,
+					 struct ieee80211_rate *rate)
 {
 	struct sk_buff_head reorder_release;
 	ieee80211_rx_result res = RX_DROP_MONITOR;
@@ -3246,7 +3311,7 @@ static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
 
 	ieee80211_rx_reorder_ampdu(rx, &reorder_release);
 
-	ieee80211_rx_handlers(rx, &reorder_release);
+	ieee80211_rx_handlers(rx, &reorder_release, rate);
 	return;
 
  rxh_next:
@@ -3292,7 +3357,7 @@ void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
 		drv_event_callback(rx.local, rx.sdata, &event);
 	}
 
-	ieee80211_rx_handlers(&rx, &frames);
+	ieee80211_rx_handlers(&rx, &frames, NULL);
 }
 
 /* main receive path */
@@ -3415,7 +3480,9 @@ static bool ieee80211_accept_frame(struct ieee80211_rx_data *rx)
  * or not the skb was consumed.
  */
 static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
-					    struct sk_buff *skb, bool consume)
+					    struct sk_buff *skb,
+					    struct ieee80211_rate *rate,
+					    bool consume)
 {
 	struct ieee80211_local *local = rx->local;
 	struct ieee80211_sub_if_data *sdata = rx->sdata;
@@ -3438,7 +3505,7 @@ static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
 		rx->skb = skb;
 	}
 
-	ieee80211_invoke_rx_handlers(rx);
+	ieee80211_invoke_rx_handlers(rx, rate);
 	return true;
 }
 
@@ -3448,7 +3515,8 @@ static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
  */
 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 					 struct sk_buff *skb,
-					 struct napi_struct *napi)
+					 struct napi_struct *napi,
+					 struct ieee80211_rate *rate)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
 	struct ieee80211_sub_if_data *sdata;
@@ -3507,7 +3575,7 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 
 			rx.sta = prev_sta;
 			rx.sdata = prev_sta->sdata;
-			ieee80211_prepare_and_rx_handle(&rx, skb, false);
+			ieee80211_prepare_and_rx_handle(&rx, skb, rate, false);
 
 			prev_sta = sta;
 		}
@@ -3516,7 +3584,7 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 			rx.sta = prev_sta;
 			rx.sdata = prev_sta->sdata;
 
-			if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
+			if (ieee80211_prepare_and_rx_handle(&rx, skb, rate, true))
 				return;
 			goto out;
 		}
@@ -3545,7 +3613,7 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 
 		rx.sta = sta_info_get_bss(prev, hdr->addr2);
 		rx.sdata = prev;
-		ieee80211_prepare_and_rx_handle(&rx, skb, false);
+		ieee80211_prepare_and_rx_handle(&rx, skb, rate, false);
 
 		prev = sdata;
 	}
@@ -3554,7 +3622,7 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 		rx.sta = sta_info_get_bss(prev, hdr->addr2);
 		rx.sdata = prev;
 
-		if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
+		if (ieee80211_prepare_and_rx_handle(&rx, skb, rate, true))
 			return;
 	}
 
@@ -3666,7 +3734,7 @@ void ieee80211_rx_napi(struct ieee80211_hw *hw, struct sk_buff *skb,
 	ieee80211_tpt_led_trig_rx(local,
 			((struct ieee80211_hdr *)skb->data)->frame_control,
 			skb->len);
-	__ieee80211_rx_handle_packet(hw, skb, napi);
+	__ieee80211_rx_handle_packet(hw, skb, napi, rate);
 
 	rcu_read_unlock();
 
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index bdc224d..5f1f424 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2939,6 +2939,115 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 	return NETDEV_TX_OK;
 }
 
+#ifdef CONFIG_MAC80211_CAPWAP_WTP
+
+/*
+ * inject raw 802.11 frame, processing is mostly identical
+ * to ieee80211_monitor_start_xmit, except for the different
+ * headers
+ */
+static void __ieee80211_capwap_inject_start_xmit(struct sk_buff *skb,
+						 struct net_device *dev)
+{
+	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
+	struct ieee80211_sub_if_data *sdata;
+	struct cfg80211_chan_def *chandef;
+	int tid;
+	int hdrlen;
+
+	/* check for not even having the fixed 802.11 header */
+	if (unlikely(skb->len < sizeof(struct ieee80211_hdr)))
+		goto fail; /* too short to be possibly valid */
+
+        hdrlen = ieee80211_hdrlen(hdr->frame_control);
+
+	/* does the skb contain enough to deliver on the alleged length? */
+	if (unlikely(skb->len < hdrlen))
+		goto fail; /* skb too short for claimed header length */
+
+	skb_set_mac_header(skb, 0);
+	/*
+	 * these are just fixed to the end of the rt area since we
+	 * don't have any better information and at this point, nobody cares
+	 */
+	skb_set_network_header(skb, hdrlen);
+	skb_set_transport_header(skb, hdrlen);
+
+	/*
+	 * Initialize skb->protocol if the injected frame is a data frame
+	 * carrying a rfc1042 header
+	 */
+	if (ieee80211_is_data(hdr->frame_control) &&
+	    skb->len >= hdrlen + sizeof(rfc1042_header) + 2) {
+		u8 *payload = (u8 *)hdr + hdrlen;
+
+		if (ether_addr_equal(payload, rfc1042_header))
+			skb->protocol = cpu_to_be16((payload[6] << 8) |
+						    payload[7]);
+	}
+
+	if (ieee80211_is_data_qos(hdr->frame_control)) {
+		u8 *p = ieee80211_get_qos_ctl(hdr);
+
+		skb->priority = *p & IEEE80211_QOS_CTL_TAG1D_MASK;
+	}
+	skb_set_queue_mapping(skb, ieee802_1d_to_ac[skb->priority]);
+
+	memset(info, 0, sizeof(*info));
+	info->flags = IEEE80211_TX_CTL_REQ_TX_STATUS |
+		      IEEE80211_TX_CTL_INJECTED;
+
+	/*
+	 * we might have set these flags later.....
+	 * info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
+	 * info->flags &= ~IEEE80211_TX_CTL_DONTFRAG;
+	 */
+
+	rcu_read_lock();
+
+	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (!chanctx_conf)
+		goto fail_rcu;
+
+	info->band = chanctx_conf->def.chan->band;
+
+	ieee80211_tx_stats(dev, skb->len);
+
+	ieee80211_xmit(sdata, NULL, skb);
+	rcu_read_unlock();
+
+	return;
+fail_rcu:
+	rcu_read_unlock();
+fail:
+	dev_kfree_skb(skb);
+}
+
+/**
+ * ieee80211_capwap_subif_start_xmit - netif start_xmit function for 802.3 vifs
+ * @skb: packet to be sent
+ * @dev: incoming interface
+ *
+ * On failure skb will be freed.
+ */
+netdev_tx_t ieee80211_capwap_subif_start_xmit(struct sk_buff *skb,
+				       struct net_device *dev)
+{
+	if (skb->protocol == htons(ETH_P_CONTROL)) {
+		__ieee80211_capwap_inject_start_xmit(skb, dev);
+	} else
+		__ieee80211_subif_start_xmit(skb, dev, 0);
+
+	return NETDEV_TX_OK;
+}
+
+#endif
+
 struct sk_buff *
 ieee80211_build_data_template(struct ieee80211_sub_if_data *sdata,
 			      struct sk_buff *skb, u32 info_flags)
@@ -3914,3 +4023,180 @@ void __ieee80211_tx_skb_tid_band(struct ieee80211_sub_if_data *sdata,
 	ieee80211_xmit(sdata, NULL, skb);
 	local_bh_enable();
 }
+
+#ifdef CONFIG_MAC80211_CAPWAP_WTP
+
+netdev_tx_t ieee80211_inject_xmit(struct sk_buff* skb, struct net_device* dev) {
+	int multicast;
+	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+	struct ieee80211_sub_if_data *sdata;
+	struct cfg80211_chan_def *chandef;
+	struct ieee80211_hdr *hdr;
+	int hdrlen;
+	int queue_index;
+
+	/* */
+	if (skb->len < hdrlen) {
+		goto error;
+	}
+
+	/* */
+	skb->dev = dev;
+	skb_reset_mac_header(skb);
+	skb_reset_network_header(skb);
+	skb_reset_transport_header(skb);
+
+	hdr = (struct ieee80211_hdr *)skb->data;
+	hdrlen = ieee80211_hdrlen(hdr->frame_control);
+
+	if (skb->len < hdrlen) {
+		printk(KERN_WARNING, "droping packet for TO SMALL");
+		goto error;
+	}
+
+	/*
+	 * Initialize skb->protocol if the injected frame is a data frame
+	 * carrying a rfc1042 header
+	 */
+	if (ieee80211_is_data(hdr->frame_control) &&
+	    skb->len >= hdrlen + sizeof(rfc1042_header) + 2) {
+		u8 *payload = (u8 *)hdr + hdrlen;
+
+		if (ether_addr_equal(payload, rfc1042_header))
+			skb->protocol = cpu_to_be16((payload[6] << 8) |
+						    payload[7]);
+	}
+
+	memset(info, 0, sizeof(struct ieee80211_tx_info));
+
+	rcu_read_lock();
+
+	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+	if (sdata->vif.type != NL80211_IFTYPE_AP) {
+		printk(KERN_WARNING, "droping packet for NOT AP");
+		goto error_rcu;
+	}
+
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (!chanctx_conf) {
+		printk(KERN_WARNING, "droping packet for NO CHANTX");
+		goto error_rcu;
+	}
+
+	chandef = &chanctx_conf->def;
+
+	queue_index = ieee80211_select_queue_80211(sdata, skb, hdr);
+	skb_set_queue_mapping(skb, queue_index);
+
+	info->band = chandef->chan->band;
+	info->hw_queue =
+		sdata->vif.hw_queue[queue_index];
+
+	/*
+	 * Frame injection is not allowed if beaconing is not allowed
+	 * or if we need radar detection. Beaconing is usually not allowed when
+	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
+	 * Passive scan is also used in world regulatory domains where
+	 * your country is not known and as such it should be treated as
+	 * NO TX unless the channel is explicitly allowed in which case
+	 * your current regulatory domain would not have the passive scan
+	 * flag.
+	 *
+	 * Since AP mode uses monitor interfaces to inject/TX management
+	 * frames we can make AP mode the exception to this rule once it
+	 * supports radar detection as its implementation can deal with
+	 * radar detection by itself. We can do that later by adding a
+	 * monitor flag interfaces used for AP support.
+	 */
+	if (!cfg80211_reg_can_beacon(local->hw.wiphy, chandef,
+				     sdata->vif.type)) {
+		printk(KERN_WARNING, "droping packet for CAN NOT BEACON");
+		goto error_rcu;
+	}
+	/* */
+	multicast = is_multicast_ether_addr(hdr->addr1);
+	if (!multicast) {
+		struct sta_info* sta = sta_info_get(sdata, hdr->addr1);
+		if (sta && test_sta_flag(sta, WLAN_STA_AUTHORIZED)) {
+			skb->pkt_type = PACKET_OTHERHOST;
+		} else {
+			printk(KERN_WARNING, "droping packet for STA not AUTHORIZED");
+			goto error_rcu;
+		}
+	} else {
+		if (ether_addr_equal_64bits(hdr->addr1, dev->broadcast)) {
+			skb->pkt_type = PACKET_BROADCAST;
+		} else {
+			skb->pkt_type = PACKET_MULTICAST;
+		}
+	}
+
+	/* */
+	if (unlikely(!multicast && skb->sk &&
+		     skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS)) {
+		struct sk_buff *ack_skb = skb_clone_sk(skb);
+
+		if (ack_skb) {
+			unsigned long flags;
+			int id;
+			struct ieee80211_local* local = sdata->local;
+
+			spin_lock_irqsave(&local->ack_status_lock, flags);
+			id = idr_alloc(&local->ack_status_frames, ack_skb,
+				       1, 0x10000, GFP_ATOMIC);
+			spin_unlock_irqrestore(&local->ack_status_lock, flags);
+
+			if (id >= 0) {
+				info->ack_frame_id = id;
+				info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
+			} else {
+				kfree_skb(ack_skb);
+			}
+		}
+	}
+
+#if 0
+	/* If the skb is shared we need to obtain our own copy. */
+	if (skb_shared(skb)) {
+		struct sk_buff *tmp_skb = skb;
+
+		/* can't happen -- skb is a clone if info_id != 0 */
+		WARN_ON(info->ack_frame_id);
+
+		skb = skb_clone(skb, GFP_ATOMIC);
+		kfree_skb(tmp_skb);
+
+		if (!skb)
+			goto error_rcu;
+	}
+#endif
+
+	/* */
+	hdr->duration_id = 0;
+	hdr->seq_ctrl = 0;
+
+	/* */
+	ieee80211_tx_stats(dev, skb->len);
+
+	/* */
+/*	dev->trans_start = jiffies; */
+
+	/* */
+	ieee80211_xmit(sdata, NULL, skb);
+	rcu_read_unlock();
+
+	return NETDEV_TX_OK;
+
+error_rcu:
+	rcu_read_unlock();
+
+error:
+	dev_kfree_skb(skb);
+	return NETDEV_TX_OK;
+}
+EXPORT_SYMBOL(ieee80211_inject_xmit);
+
+#endif
-- 
2.9.3