/*
   * Copyright 2002-2005, Instant802 Networks, Inc.
   * Copyright 2005-2006, Devicescape Software, Inc.
   * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
   * Copyright 2007-2010	Johannes Berg <johannes@sipsolutions.net>
   *
   * 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/jiffies.h>
  #include <linux/slab.h>
  #include <linux/kernel.h>
  #include <linux/skbuff.h>
  #include <linux/netdevice.h>
  #include <linux/etherdevice.h>
  #include <linux/rcupdate.h>
  #include <linux/export.h>
  #include <net/mac80211.h>
  #include <net/ieee80211_radiotap.h>
  #include <asm/unaligned.h>
  
  #include "ieee80211_i.h"
  #include "driver-ops.h"
  #include "led.h"
  #include "mesh.h"
  #include "wep.h"
  #include "wpa.h"
  #include "tkip.h"
  #include "wme.h"
  #include "rate.h"
  
  /*
   * monitor mode reception
   *
   * This function cleans up the SKB, i.e. it removes all the stuff
   * only useful for monitoring.
   */
  static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  					   struct sk_buff *skb)
  {
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  
  	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  		if (likely(skb->len > FCS_LEN))
  			__pskb_trim(skb, skb->len - FCS_LEN);
  		else {
  			/* driver bug */
  			WARN_ON(1);
  			dev_kfree_skb(skb);
  			return NULL;
  		}
  	}
  
  	if (status->vendor_radiotap_len)
  		__pskb_pull(skb, status->vendor_radiotap_len);
  
  	return skb;
  }
  
  static inline int should_drop_frame(struct sk_buff *skb, int present_fcs_len)
  {
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  	struct ieee80211_hdr *hdr;
  
  	hdr = (void *)(skb->data + status->vendor_radiotap_len);
  
  	if (status->flag & (RX_FLAG_FAILED_FCS_CRC |
  			    RX_FLAG_FAILED_PLCP_CRC |
  			    RX_FLAG_AMPDU_IS_ZEROLEN))
  		return 1;
  	if (unlikely(skb->len < 16 + present_fcs_len +
  				status->vendor_radiotap_len))
  		return 1;
  	if (ieee80211_is_ctl(hdr->frame_control) &&
  	    !ieee80211_is_pspoll(hdr->frame_control) &&
  	    !ieee80211_is_back_req(hdr->frame_control))
  		return 1;
  	return 0;
  }
  
  static int
  ieee80211_rx_radiotap_space(struct ieee80211_local *local,
  			    struct ieee80211_rx_status *status)
  {
  	int len;
  
  	/* always present fields */
  	len = sizeof(struct ieee80211_radiotap_header) + 8;
  
  	/* allocate extra bitmaps */
  	if (status->vendor_radiotap_len)
  		len += 4;
  	if (status->chains)
  		len += 4 * hweight8(status->chains);
  
  	if (ieee80211_have_rx_timestamp(status)) {
  		len = ALIGN(len, 8);
  		len += 8;
  	}
  	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  		len += 1;
  
  	/* antenna field, if we don't have per-chain info */
  	if (!status->chains)
  		len += 1;
  
  	/* padding for RX_FLAGS if necessary */
  	len = ALIGN(len, 2);
  
  	if (status->flag & RX_FLAG_HT) /* HT info */
  		len += 3;
  
  	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
  		len = ALIGN(len, 4);
  		len += 8;
  	}
  
  	if (status->flag & RX_FLAG_VHT) {
  		len = ALIGN(len, 2);
  		len += 12;
  	}
  
  	if (status->chains) {
  		/* antenna and antenna signal fields */
  		len += 2 * hweight8(status->chains);
  	}
  
  	if (status->vendor_radiotap_len) {
  		if (WARN_ON_ONCE(status->vendor_radiotap_align == 0))
  			status->vendor_radiotap_align = 1;
  		/* align standard part of vendor namespace */
  		len = ALIGN(len, 2);
  		/* allocate standard part of vendor namespace */
  		len += 6;
  		/* align vendor-defined part */
  		len = ALIGN(len, status->vendor_radiotap_align);
  		/* vendor-defined part is already in skb */
  	}
  
  	return len;
  }
  
  /*
   * ieee80211_add_rx_radiotap_header - add radiotap header
   *
   * add a radiotap header containing all the fields which the hardware provided.
   */
  static void
  ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
  				 struct sk_buff *skb,
  				 struct ieee80211_rate *rate,
  				 int rtap_len, bool has_fcs)
  {
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  	struct ieee80211_radiotap_header *rthdr;
  	unsigned char *pos;
  	__le32 *it_present;
  	u32 it_present_val;
  	u16 rx_flags = 0;
  	u16 channel_flags = 0;
  	int mpdulen, chain;
  	unsigned long chains = status->chains;
  
  	mpdulen = skb->len;
  	if (!(has_fcs && (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)))
  		mpdulen += FCS_LEN;
  
  	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
  	memset(rthdr, 0, rtap_len);
  	it_present = &rthdr->it_present;
  
  	/* radiotap header, set always present flags */
  	rthdr->it_len = cpu_to_le16(rtap_len + status->vendor_radiotap_len);
  	it_present_val = BIT(IEEE80211_RADIOTAP_FLAGS) |
  			 BIT(IEEE80211_RADIOTAP_CHANNEL) |
  			 BIT(IEEE80211_RADIOTAP_RX_FLAGS);
  
  	if (!status->chains)
  		it_present_val |= BIT(IEEE80211_RADIOTAP_ANTENNA);
  
  	for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
  		it_present_val |=
  			BIT(IEEE80211_RADIOTAP_EXT) |
  			BIT(IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE);
  		put_unaligned_le32(it_present_val, it_present);
  		it_present++;
  		it_present_val = BIT(IEEE80211_RADIOTAP_ANTENNA) |
  				 BIT(IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
  	}
  
  	if (status->vendor_radiotap_len) {
  		it_present_val |= BIT(IEEE80211_RADIOTAP_VENDOR_NAMESPACE) |
  				  BIT(IEEE80211_RADIOTAP_EXT);
  		put_unaligned_le32(it_present_val, it_present);
  		it_present++;
  		it_present_val = status->vendor_radiotap_bitmap;
  	}
  
  	put_unaligned_le32(it_present_val, it_present);
  
  	pos = (void *)(it_present + 1);
  
  	/* the order of the following fields is important */
  
  	/* IEEE80211_RADIOTAP_TSFT */
  	if (ieee80211_have_rx_timestamp(status)) {
  		/* padding */
  		while ((pos - (u8 *)rthdr) & 7)
  			*pos++ = 0;
  		put_unaligned_le64(
  			ieee80211_calculate_rx_timestamp(local, status,
  							 mpdulen, 0),
  			pos);
  		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
  		pos += 8;
  	}
  
  	/* IEEE80211_RADIOTAP_FLAGS */
  	if (has_fcs && (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS))
  		*pos |= IEEE80211_RADIOTAP_F_FCS;
  	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  		*pos |= IEEE80211_RADIOTAP_F_BADFCS;
  	if (status->flag & RX_FLAG_SHORTPRE)
  		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
  	pos++;
  
  	/* IEEE80211_RADIOTAP_RATE */
  	if (!rate || status->flag & (RX_FLAG_HT | RX_FLAG_VHT)) {
  		/*
  		 * Without rate information don't add it. If we have,
  		 * MCS information is a separate field in radiotap,
  		 * added below. The byte here is needed as padding
  		 * for the channel though, so initialise it to 0.
  		 */
  		*pos = 0;
  	} else {
  		int shift = 0;
  		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
  		if (status->flag & RX_FLAG_10MHZ)
  			shift = 1;
  		else if (status->flag & RX_FLAG_5MHZ)
  			shift = 2;
  		*pos = DIV_ROUND_UP(rate->bitrate, 5 * (1 << shift));
  	}
  	pos++;
  
  	/* IEEE80211_RADIOTAP_CHANNEL */
  	put_unaligned_le16(status->freq, pos);
  	pos += 2;
  	if (status->flag & RX_FLAG_10MHZ)
  		channel_flags |= IEEE80211_CHAN_HALF;
  	else if (status->flag & RX_FLAG_5MHZ)
  		channel_flags |= IEEE80211_CHAN_QUARTER;
  
  	if (status->band == IEEE80211_BAND_5GHZ)
  		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ;
  	else if (status->flag & (RX_FLAG_HT | RX_FLAG_VHT))
  		channel_flags |= IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ;
  	else if (rate && rate->flags & IEEE80211_RATE_ERP_G)
  		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ;
  	else if (rate)
  		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ;
  	else
  		channel_flags |= IEEE80211_CHAN_2GHZ;
  	put_unaligned_le16(channel_flags, pos);
  	pos += 2;
  
  	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
  	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM &&
  	    !(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
  		*pos = status->signal;
  		rthdr->it_present |=
  			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
  		pos++;
  	}
  
  	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
  
  	if (!status->chains) {
  		/* IEEE80211_RADIOTAP_ANTENNA */
  		*pos = status->antenna;
  		pos++;
  	}
  
  	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
  
  	/* IEEE80211_RADIOTAP_RX_FLAGS */
  	/* ensure 2 byte alignment for the 2 byte field as required */
  	if ((pos - (u8 *)rthdr) & 1)
  		*pos++ = 0;
  	if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
  		rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
  	put_unaligned_le16(rx_flags, pos);
  	pos += 2;
  
  	if (status->flag & RX_FLAG_HT) {
  		unsigned int stbc;
  
  		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
  		*pos++ = local->hw.radiotap_mcs_details;
  		*pos = 0;
  		if (status->flag & RX_FLAG_SHORT_GI)
  			*pos |= IEEE80211_RADIOTAP_MCS_SGI;
  		if (status->flag & RX_FLAG_40MHZ)
  			*pos |= IEEE80211_RADIOTAP_MCS_BW_40;
  		if (status->flag & RX_FLAG_HT_GF)
  			*pos |= IEEE80211_RADIOTAP_MCS_FMT_GF;
  		stbc = (status->flag & RX_FLAG_STBC_MASK) >> RX_FLAG_STBC_SHIFT;
  		*pos |= stbc << IEEE80211_RADIOTAP_MCS_STBC_SHIFT;
  		pos++;
  		*pos++ = status->rate_idx;
  	}
  
  	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
  		u16 flags = 0;
  
  		/* ensure 4 byte alignment */
  		while ((pos - (u8 *)rthdr) & 3)
  			pos++;
  		rthdr->it_present |=
  			cpu_to_le32(1 << IEEE80211_RADIOTAP_AMPDU_STATUS);
  		put_unaligned_le32(status->ampdu_reference, pos);
  		pos += 4;
  		if (status->flag & RX_FLAG_AMPDU_REPORT_ZEROLEN)
  			flags |= IEEE80211_RADIOTAP_AMPDU_REPORT_ZEROLEN;
  		if (status->flag & RX_FLAG_AMPDU_IS_ZEROLEN)
  			flags |= IEEE80211_RADIOTAP_AMPDU_IS_ZEROLEN;
  		if (status->flag & RX_FLAG_AMPDU_LAST_KNOWN)
  			flags |= IEEE80211_RADIOTAP_AMPDU_LAST_KNOWN;
  		if (status->flag & RX_FLAG_AMPDU_IS_LAST)
  			flags |= IEEE80211_RADIOTAP_AMPDU_IS_LAST;
  		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_ERROR)
  			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_ERR;
  		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
  			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_KNOWN;
  		put_unaligned_le16(flags, pos);
  		pos += 2;
  		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
  			*pos++ = status->ampdu_delimiter_crc;
  		else
  			*pos++ = 0;
  		*pos++ = 0;
  	}
  
  	if (status->flag & RX_FLAG_VHT) {
  		u16 known = local->hw.radiotap_vht_details;
  
  		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
  		/* known field - how to handle 80+80? */
  		if (status->flag & RX_FLAG_80P80MHZ)
  			known &= ~IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH;
  		put_unaligned_le16(known, pos);
  		pos += 2;
  		/* flags */
  		if (status->flag & RX_FLAG_SHORT_GI)
  			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
  		pos++;
  		/* bandwidth */
  		if (status->flag & RX_FLAG_80MHZ)
  			*pos++ = 4;
  		else if (status->flag & RX_FLAG_80P80MHZ)
  			*pos++ = 0; /* marked not known above */
  		else if (status->flag & RX_FLAG_160MHZ)
  			*pos++ = 11;
  		else if (status->flag & RX_FLAG_40MHZ)
  			*pos++ = 1;
  		else /* 20 MHz */
  			*pos++ = 0;
  		/* MCS/NSS */
  		*pos = (status->rate_idx << 4) | status->vht_nss;
  		pos += 4;
  		/* coding field */
  		pos++;
  		/* group ID */
  		pos++;
  		/* partial_aid */
  		pos += 2;
  	}
  
  	for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
  		*pos++ = status->chain_signal[chain];
  		*pos++ = chain;
  	}
  
  	if (status->vendor_radiotap_len) {
  		/* ensure 2 byte alignment for the vendor field as required */
  		if ((pos - (u8 *)rthdr) & 1)
  			*pos++ = 0;
  		*pos++ = status->vendor_radiotap_oui[0];
  		*pos++ = status->vendor_radiotap_oui[1];
  		*pos++ = status->vendor_radiotap_oui[2];
  		*pos++ = status->vendor_radiotap_subns;
  		put_unaligned_le16(status->vendor_radiotap_len, pos);
  		pos += 2;
  		/* align the actual payload as requested */
  		while ((pos - (u8 *)rthdr) & (status->vendor_radiotap_align - 1))
  			*pos++ = 0;
  	}
  }
  
  /*
   * This function copies a received frame to all monitor interfaces and
   * returns a cleaned-up SKB that no longer includes the FCS nor the
   * radiotap header the driver might have added.
   */
  static struct sk_buff *
  ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
  		     struct ieee80211_rate *rate)
  {
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
  	struct ieee80211_sub_if_data *sdata;
  	int needed_headroom;
  	struct sk_buff *skb, *skb2;
  	struct net_device *prev_dev = NULL;
  	int present_fcs_len = 0;
  
  	/*
  	 * First, we may need to make a copy of the skb because
  	 *  (1) we need to modify it for radiotap (if not present), and
  	 *  (2) the other RX handlers will modify the skb we got.
  	 *
  	 * We don't need to, of course, if we aren't going to return
  	 * the SKB because it has a bad FCS/PLCP checksum.
  	 */
  
  	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
  		present_fcs_len = FCS_LEN;
  
  	/* ensure hdr->frame_control and vendor radiotap data are in skb head */
  	if (!pskb_may_pull(origskb, 2 + status->vendor_radiotap_len)) {
  		dev_kfree_skb(origskb);
  		return NULL;
  	}
  
  	if (!local->monitors) {
  		if (should_drop_frame(origskb, present_fcs_len)) {
  			dev_kfree_skb(origskb);
  			return NULL;
  		}
  
  		return remove_monitor_info(local, origskb);
  	}
  
  	/* room for the radiotap header based on driver features */
  	needed_headroom = ieee80211_rx_radiotap_space(local, status);
  
  	if (should_drop_frame(origskb, present_fcs_len)) {
  		/* only need to expand headroom if necessary */
  		skb = origskb;
  		origskb = NULL;
  
  		/*
  		 * This shouldn't trigger often because most devices have an
  		 * RX header they pull before we get here, and that should
  		 * be big enough for our radiotap information. We should
  		 * probably export the length to drivers so that we can have
  		 * them allocate enough headroom to start with.
  		 */
  		if (skb_headroom(skb) < needed_headroom &&
  		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
  			dev_kfree_skb(skb);
  			return NULL;
  		}
  	} else {
  		/*
  		 * Need to make a copy and possibly remove radiotap header
  		 * and FCS from the original.
  		 */
  		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
  
  		origskb = remove_monitor_info(local, origskb);
  
  		if (!skb)
  			return origskb;
  	}
  
  	/* prepend radiotap information */
  	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom,
  					 true);
  
  	skb_reset_mac_header(skb);
  	skb->ip_summed = CHECKSUM_UNNECESSARY;
  	skb->pkt_type = PACKET_OTHERHOST;
  	skb->protocol = htons(ETH_P_802_2);
  
  	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
  		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
  			continue;
  
  		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
  			continue;
  
  		if (!ieee80211_sdata_running(sdata))
  			continue;
  
  		if (prev_dev) {
  			skb2 = skb_clone(skb, GFP_ATOMIC);
  			if (skb2) {
  				skb2->dev = prev_dev;
  				netif_receive_skb(skb2);
  			}
  		}
  
  		prev_dev = sdata->dev;
  		sdata->dev->stats.rx_packets++;
  		sdata->dev->stats.rx_bytes += skb->len;
  	}
  
  	if (prev_dev) {
  		skb->dev = prev_dev;
  		netif_receive_skb(skb);
  	} else
  		dev_kfree_skb(skb);
  
  	return origskb;
  }
  
  static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
  {
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
  	int tid, seqno_idx, security_idx;
  
  	/* does the frame have a qos control field? */
  	if (ieee80211_is_data_qos(hdr->frame_control)) {
  		u8 *qc = ieee80211_get_qos_ctl(hdr);
  		/* frame has qos control */
  		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
  		if (*qc & IEEE80211_QOS_CTL_A_MSDU_PRESENT)
  			status->rx_flags |= IEEE80211_RX_AMSDU;
  
  		seqno_idx = tid;
  		security_idx = tid;
  	} else {
  		/*
  		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
  		 *
  		 *	Sequence numbers for management frames, QoS data
  		 *	frames with a broadcast/multicast address in the
  		 *	Address 1 field, and all non-QoS data frames sent
  		 *	by QoS STAs are assigned using an additional single
  		 *	modulo-4096 counter, [...]
  		 *
  		 * We also use that counter for non-QoS STAs.
  		 */
  		seqno_idx = IEEE80211_NUM_TIDS;
  		security_idx = 0;
  		if (ieee80211_is_mgmt(hdr->frame_control))
  			security_idx = IEEE80211_NUM_TIDS;
  		tid = 0;
  	}
  
  	rx->seqno_idx = seqno_idx;
  	rx->security_idx = security_idx;
  	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
  	 * For now, set skb->priority to 0 for other cases. */
  	rx->skb->priority = (tid > 7) ? 0 : tid;
  }
  
  /**
   * DOC: Packet alignment
   *
   * Drivers always need to pass packets that are aligned to two-byte boundaries
   * to the stack.
   *
   * Additionally, should, if possible, align the payload data in a way that
   * guarantees that the contained IP header is aligned to a four-byte
   * boundary. In the case of regular frames, this simply means aligning the
   * payload to a four-byte boundary (because either the IP header is directly
   * contained, or IV/RFC1042 headers that have a length divisible by four are
   * in front of it).  If the payload data is not properly aligned and the
   * architecture doesn't support efficient unaligned operations, mac80211
   * will align the data.
   *
   * With A-MSDU frames, however, the payload data address must yield two modulo
   * four because there are 14-byte 802.3 headers within the A-MSDU frames that
   * push the IP header further back to a multiple of four again. Thankfully, the
   * specs were sane enough this time around to require padding each A-MSDU
   * subframe to a length that is a multiple of four.
   *
   * Padding like Atheros hardware adds which is between the 802.11 header and
   * the payload is not supported, the driver is required to move the 802.11
   * header to be directly in front of the payload in that case.
   */
  static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
  {
  #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
  	WARN_ONCE((unsigned long)rx->skb->data & 1,
  		  "unaligned packet at 0x%p
  ", rx->skb->data);
  #endif
  }
  
  
  /* rx handlers */
  
  static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
  {
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
  
  	if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
  		return 0;
  
  	return ieee80211_is_robust_mgmt_frame(hdr);
  }
  
  
  static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
  {
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
  
  	if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
  		return 0;
  
  	return ieee80211_is_robust_mgmt_frame(hdr);
  }
  
  
  /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
  static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
  {
  	struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
  	struct ieee80211_mmie *mmie;
  
  	if (skb->len < 24 + sizeof(*mmie) || !is_multicast_ether_addr(hdr->da))
  		return -1;
  
  	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
  		return -1; /* not a robust management frame */
  
  	mmie = (struct ieee80211_mmie *)
  		(skb->data + skb->len - sizeof(*mmie));
  	if (mmie->element_id != WLAN_EID_MMIE ||
  	    mmie->length != sizeof(*mmie) - 2)
  		return -1;
  
  	return le16_to_cpu(mmie->key_id);
  }
  
  static int iwl80211_get_cs_keyid(const struct ieee80211_cipher_scheme *cs,
  				 struct sk_buff *skb)
  {
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  	__le16 fc;
  	int hdrlen;
  	u8 keyid;
  
  	fc = hdr->frame_control;
  	hdrlen = ieee80211_hdrlen(fc);
  
  	if (skb->len < hdrlen + cs->hdr_len)
  		return -EINVAL;
  
  	skb_copy_bits(skb, hdrlen + cs->key_idx_off, &keyid, 1);
  	keyid &= cs->key_idx_mask;
  	keyid >>= cs->key_idx_shift;
  
  	return keyid;
  }
  
  static ieee80211_rx_result ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
  {
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
  	char *dev_addr = rx->sdata->vif.addr;
  
  	if (ieee80211_is_data(hdr->frame_control)) {
  		if (is_multicast_ether_addr(hdr->addr1)) {
  			if (ieee80211_has_tods(hdr->frame_control) ||
  			    !ieee80211_has_fromds(hdr->frame_control))
  				return RX_DROP_MONITOR;
  			if (ether_addr_equal(hdr->addr3, dev_addr))
  				return RX_DROP_MONITOR;
  		} else {
  			if (!ieee80211_has_a4(hdr->frame_control))
  				return RX_DROP_MONITOR;
  			if (ether_addr_equal(hdr->addr4, dev_addr))
  				return RX_DROP_MONITOR;
  		}
  	}
  
  	/* If there is not an established peer link and this is not a peer link
  	 * establisment frame, beacon or probe, drop the frame.
  	 */
  
  	if (!rx->sta || sta_plink_state(rx->sta) != NL80211_PLINK_ESTAB) {
  		struct ieee80211_mgmt *mgmt;
  
  		if (!ieee80211_is_mgmt(hdr->frame_control))
  			return RX_DROP_MONITOR;
  
  		if (ieee80211_is_action(hdr->frame_control)) {
  			u8 category;
  
  			/* make sure category field is present */
  			if (rx->skb->len < IEEE80211_MIN_ACTION_SIZE)
  				return RX_DROP_MONITOR;
  
  			mgmt = (struct ieee80211_mgmt *)hdr;
  			category = mgmt->u.action.category;
  			if (category != WLAN_CATEGORY_MESH_ACTION &&
  			    category != WLAN_CATEGORY_SELF_PROTECTED)
  				return RX_DROP_MONITOR;
  			return RX_CONTINUE;
  		}
  
  		if (ieee80211_is_probe_req(hdr->frame_control) ||
  		    ieee80211_is_probe_resp(hdr->frame_control) ||
  		    ieee80211_is_beacon(hdr->frame_control) ||
  		    ieee80211_is_auth(hdr->frame_control))
  			return RX_CONTINUE;
  
  		return RX_DROP_MONITOR;
  	}
  
  	return RX_CONTINUE;
  }
  
  static void ieee80211_release_reorder_frame(struct ieee80211_sub_if_data *sdata,
  					    struct tid_ampdu_rx *tid_agg_rx,
  					    int index,
  					    struct sk_buff_head *frames)
  {
  	struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
  	struct ieee80211_rx_status *status;
  
  	lockdep_assert_held(&tid_agg_rx->reorder_lock);
  
  	if (!skb)
  		goto no_frame;
  
  	/* release the frame from the reorder ring buffer */
  	tid_agg_rx->stored_mpdu_num--;
  	tid_agg_rx->reorder_buf[index] = NULL;
  	status = IEEE80211_SKB_RXCB(skb);
  	status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
  	__skb_queue_tail(frames, skb);
  
  no_frame:
  	tid_agg_rx->head_seq_num = ieee80211_sn_inc(tid_agg_rx->head_seq_num);
  }
  
  static void ieee80211_release_reorder_frames(struct ieee80211_sub_if_data *sdata,
  					     struct tid_ampdu_rx *tid_agg_rx,
  					     u16 head_seq_num,
  					     struct sk_buff_head *frames)
  {
  	int index;
  
  	lockdep_assert_held(&tid_agg_rx->reorder_lock);
  
  	while (ieee80211_sn_less(tid_agg_rx->head_seq_num, head_seq_num)) {
  		index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
  		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
  						frames);
  	}
  }
  
  /*
   * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
   * the skb was added to the buffer longer than this time ago, the earlier
   * frames that have not yet been received are assumed to be lost and the skb
   * can be released for processing. This may also release other skb's from the
   * reorder buffer if there are no additional gaps between the frames.
   *
   * Callers must hold tid_agg_rx->reorder_lock.
   */
  #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
  
  static void ieee80211_sta_reorder_release(struct ieee80211_sub_if_data *sdata,
  					  struct tid_ampdu_rx *tid_agg_rx,
  					  struct sk_buff_head *frames)
  {
  	int index, j;
  
  	lockdep_assert_held(&tid_agg_rx->reorder_lock);
  
  	/* release the buffer until next missing frame */
  	index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
  	if (!tid_agg_rx->reorder_buf[index] &&
  	    tid_agg_rx->stored_mpdu_num) {
  		/*
  		 * No buffers ready to be released, but check whether any
  		 * frames in the reorder buffer have timed out.
  		 */
  		int skipped = 1;
  		for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
  		     j = (j + 1) % tid_agg_rx->buf_size) {
  			if (!tid_agg_rx->reorder_buf[j]) {
  				skipped++;
  				continue;
  			}
  			if (skipped &&
  			    !time_after(jiffies, tid_agg_rx->reorder_time[j] +
  					HT_RX_REORDER_BUF_TIMEOUT))
  				goto set_release_timer;
  
  			ht_dbg_ratelimited(sdata,
  					   "release an RX reorder frame due to timeout on earlier frames
  ");
  			ieee80211_release_reorder_frame(sdata, tid_agg_rx, j,
  							frames);
  
  			/*
  			 * Increment the head seq# also for the skipped slots.
  			 */
  			tid_agg_rx->head_seq_num =
  				(tid_agg_rx->head_seq_num +
  				 skipped) & IEEE80211_SN_MASK;
  			skipped = 0;
  		}
  	} else while (tid_agg_rx->reorder_buf[index]) {
  		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
  						frames);
  		index =	tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
  	}
  
  	if (tid_agg_rx->stored_mpdu_num) {
  		j = index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
  
  		for (; j != (index - 1) % tid_agg_rx->buf_size;
  		     j = (j + 1) % tid_agg_rx->buf_size) {
  			if (tid_agg_rx->reorder_buf[j])
  				break;
  		}
  
   set_release_timer:
  
  		mod_timer(&tid_agg_rx->reorder_timer,
  			  tid_agg_rx->reorder_time[j] + 1 +
  			  HT_RX_REORDER_BUF_TIMEOUT);
  	} else {
  		del_timer(&tid_agg_rx->reorder_timer);
  	}
  }
  
  /*
   * As this function belongs to the RX path it must be under
   * rcu_read_lock protection. It returns false if the frame
   * can be processed immediately, true if it was consumed.
   */
  static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_sub_if_data *sdata,
  					     struct tid_ampdu_rx *tid_agg_rx,
  					     struct sk_buff *skb,
  					     struct sk_buff_head *frames)
  {
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
  	u16 sc = le16_to_cpu(hdr->seq_ctrl);
  	u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
  	u16 head_seq_num, buf_size;
  	int index;
  	bool ret = true;
  
  	spin_lock(&tid_agg_rx->reorder_lock);
  
  	buf_size = tid_agg_rx->buf_size;
  	head_seq_num = tid_agg_rx->head_seq_num;
  
  	/* frame with out of date sequence number */
  	if (ieee80211_sn_less(mpdu_seq_num, head_seq_num)) {
  		dev_kfree_skb(skb);
  		goto out;
  	}
  
  	/*
  	 * If frame the sequence number exceeds our buffering window
  	 * size release some previous frames to make room for this one.
  	 */
  	if (!ieee80211_sn_less(mpdu_seq_num, head_seq_num + buf_size)) {
  		head_seq_num = ieee80211_sn_inc(
  				ieee80211_sn_sub(mpdu_seq_num, buf_size));
  		/* release stored frames up to new head to stack */
  		ieee80211_release_reorder_frames(sdata, tid_agg_rx,
  						 head_seq_num, frames);
  	}
  
  	/* Now the new frame is always in the range of the reordering buffer */
  
  	index = mpdu_seq_num % tid_agg_rx->buf_size;
  
  	/* check if we already stored this frame */
  	if (tid_agg_rx->reorder_buf[index]) {
  		dev_kfree_skb(skb);
  		goto out;
  	}
  
  	/*
  	 * If the current MPDU is in the right order and nothing else
  	 * is stored we can process it directly, no need to buffer it.
  	 * If it is first but there's something stored, we may be able
  	 * to release frames after this one.
  	 */
  	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
  	    tid_agg_rx->stored_mpdu_num == 0) {
  		tid_agg_rx->head_seq_num =
  			ieee80211_sn_inc(tid_agg_rx->head_seq_num);
  		ret = false;
  		goto out;
  	}
  
  	/* put the frame in the reordering buffer */
  	tid_agg_rx->reorder_buf[index] = skb;
  	tid_agg_rx->reorder_time[index] = jiffies;
  	tid_agg_rx->stored_mpdu_num++;
  	ieee80211_sta_reorder_release(sdata, tid_agg_rx, frames);
  
   out:
  	spin_unlock(&tid_agg_rx->reorder_lock);
  	return ret;
  }
  
  /*
   * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
   * true if the MPDU was buffered, false if it should be processed.
   */
  static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
  				       struct sk_buff_head *frames)
  {
  	struct sk_buff *skb = rx->skb;
  	struct ieee80211_local *local = rx->local;
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  	struct sta_info *sta = rx->sta;
  	struct tid_ampdu_rx *tid_agg_rx;
  	u16 sc;
  	u8 tid, ack_policy;
  
  	if (!ieee80211_is_data_qos(hdr->frame_control) ||
  	    is_multicast_ether_addr(hdr->addr1))
  		goto dont_reorder;
  
  	/*
  	 * filter the QoS data rx stream according to
  	 * STA/TID and check if this STA/TID is on aggregation
  	 */
  
  	if (!sta)
  		goto dont_reorder;
  
  	ack_policy = *ieee80211_get_qos_ctl(hdr) &
  		     IEEE80211_QOS_CTL_ACK_POLICY_MASK;
  	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
  
  	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
  	if (!tid_agg_rx)
  		goto dont_reorder;
  
  	/* qos null data frames are excluded */
  	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
  		goto dont_reorder;
  
  	/* not part of a BA session */
  	if (ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_BLOCKACK &&
  	    ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_NORMAL)
  		goto dont_reorder;
  
  	/* not actually part of this BA session */
  	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
  		goto dont_reorder;
  
  	/* new, potentially un-ordered, ampdu frame - process it */
  
  	/* reset session timer */
  	if (tid_agg_rx->timeout)
  		tid_agg_rx->last_rx = jiffies;
  
  	/* if this mpdu is fragmented - terminate rx aggregation session */
  	sc = le16_to_cpu(hdr->seq_ctrl);
  	if (sc & IEEE80211_SCTL_FRAG) {
  		skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
  		skb_queue_tail(&rx->sdata->skb_queue, skb);
  		ieee80211_queue_work(&local->hw, &rx->sdata->work);
  		return;
  	}
  
  	/*
  	 * No locking needed -- we will only ever process one
  	 * RX packet at a time, and thus own tid_agg_rx. All
  	 * other code manipulating it needs to (and does) make
  	 * sure that we cannot get to it any more before doing
  	 * anything with it.
  	 */
  	if (ieee80211_sta_manage_reorder_buf(rx->sdata, tid_agg_rx, skb,
  					     frames))
  		return;
  
   dont_reorder:
  	__skb_queue_tail(frames, skb);
  }
  
  static ieee80211_rx_result debug_noinline
  ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
  {
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
  
  	/*
  	 * Drop duplicate 802.11 retransmissions
  	 * (IEEE 802.11-2012: 9.3.2.10 "Duplicate detection and recovery")
  	 */
  	if (rx->skb->len >= 24 && rx->sta &&
  	    !ieee80211_is_ctl(hdr->frame_control) &&
  	    !ieee80211_is_qos_nullfunc(hdr->frame_control) &&
  	    !is_multicast_ether_addr(hdr->addr1)) {
  		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
  			     rx->sta->last_seq_ctrl[rx->seqno_idx] ==
  			     hdr->seq_ctrl)) {
  			if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
  				rx->local->dot11FrameDuplicateCount++;
  				rx->sta->num_duplicates++;
  			}
  			return RX_DROP_UNUSABLE;
  		} else if (!(status->flag & RX_FLAG_AMSDU_MORE)) {
  			rx->sta->last_seq_ctrl[rx->seqno_idx] = hdr->seq_ctrl;
  		}
  	}
  
  	if (unlikely(rx->skb->len < 16)) {
  		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
  		return RX_DROP_MONITOR;
  	}
  
  	/* Drop disallowed frame classes based on STA auth/assoc state;
  	 * IEEE 802.11, Chap 5.5.
  	 *
  	 * mac80211 filters only based on association state, i.e. it drops
  	 * Class 3 frames from not associated stations. hostapd sends
  	 * deauth/disassoc frames when needed. In addition, hostapd is
  	 * responsible for filtering on both auth and assoc states.
  	 */
  
  	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
  		return ieee80211_rx_mesh_check(rx);
  
  	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
  		      ieee80211_is_pspoll(hdr->frame_control)) &&
  		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
  		     rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
  		     (!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_ASSOC)))) {
  		/*
  		 * accept port control frames from the AP even when it's not
  		 * yet marked ASSOC to prevent a race where we don't set the
  		 * assoc bit quickly enough before it sends the first frame
  		 */
  		if (rx->sta && rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
  		    ieee80211_is_data_present(hdr->frame_control)) {
  			unsigned int hdrlen;
  			__be16 ethertype;
  
  			hdrlen = ieee80211_hdrlen(hdr->frame_control);
  
  			if (rx->skb->len < hdrlen + 8)
  				return RX_DROP_MONITOR;
  
  			skb_copy_bits(rx->skb, hdrlen + 6, &ethertype, 2);
  			if (ethertype == rx->sdata->control_port_protocol)
  				return RX_CONTINUE;
  		}
  
  		if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
  		    cfg80211_rx_spurious_frame(rx->sdata->dev,
  					       hdr->addr2,
  					       GFP_ATOMIC))
  			return RX_DROP_UNUSABLE;
  
  		return RX_DROP_MONITOR;
  	}
  
  	return RX_CONTINUE;
  }
  
  
  static ieee80211_rx_result debug_noinline
  ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
  {
  	struct ieee80211_local *local;
  	struct ieee80211_hdr *hdr;
  	struct sk_buff *skb;
  
  	local = rx->local;
  	skb = rx->skb;
  	hdr = (struct ieee80211_hdr *) skb->data;
  
  	if (!local->pspolling)
  		return RX_CONTINUE;
  
  	if (!ieee80211_has_fromds(hdr->frame_control))
  		/* this is not from AP */
  		return RX_CONTINUE;
  
  	if (!ieee80211_is_data(hdr->frame_control))
  		return RX_CONTINUE;
  
  	if (!ieee80211_has_moredata(hdr->frame_control)) {
  		/* AP has no more frames buffered for us */
  		local->pspolling = false;
  		return RX_CONTINUE;
  	}
  
  	/* more data bit is set, let's request a new frame from the AP */
  	ieee80211_send_pspoll(local, rx->sdata);
  
  	return RX_CONTINUE;
  }
  
  static void sta_ps_start(struct sta_info *sta)
  {
  	struct ieee80211_sub_if_data *sdata = sta->sdata;
  	struct ieee80211_local *local = sdata->local;
  	struct ps_data *ps;
  
  	if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
  	    sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
  		ps = &sdata->bss->ps;
  	else
  		return;
  
  	atomic_inc(&ps->num_sta_ps);
  	set_sta_flag(sta, WLAN_STA_PS_STA);
  	if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
  		drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
  	ps_dbg(sdata, "STA %pM aid %d enters power save mode
  ",
  	       sta->sta.addr, sta->sta.aid);
  }
  
  static void sta_ps_end(struct sta_info *sta)
  {
  	ps_dbg(sta->sdata, "STA %pM aid %d exits power save mode
  ",
  	       sta->sta.addr, sta->sta.aid);
  
  	if (test_sta_flag(sta, WLAN_STA_PS_DRIVER)) {
  		/*
  		 * Clear the flag only if the other one is still set
  		 * so that the TX path won't start TX'ing new frames
  		 * directly ... In the case that the driver flag isn't
  		 * set ieee80211_sta_ps_deliver_wakeup() will clear it.
  		 */
  		clear_sta_flag(sta, WLAN_STA_PS_STA);
  		ps_dbg(sta->sdata, "STA %pM aid %d driver-ps-blocked
  ",
  		       sta->sta.addr, sta->sta.aid);
  		return;
  	}
  
  	ieee80211_sta_ps_deliver_wakeup(sta);
  }
  
  int ieee80211_sta_ps_transition(struct ieee80211_sta *sta, bool start)
  {
  	struct sta_info *sta_inf = container_of(sta, struct sta_info, sta);
  	bool in_ps;
  
  	WARN_ON(!(sta_inf->local->hw.flags & IEEE80211_HW_AP_LINK_PS));
  
  	/* Don't let the same PS state be set twice */
  	in_ps = test_sta_flag(sta_inf, WLAN_STA_PS_STA);
  	if ((start && in_ps) || (!start && !in_ps))
  		return -EINVAL;
  
  	if (start)
  		sta_ps_start(sta_inf);
  	else
  		sta_ps_end(sta_inf);
  
  	return 0;
  }
  EXPORT_SYMBOL(ieee80211_sta_ps_transition);
  
  static ieee80211_rx_result debug_noinline
  ieee80211_rx_h_uapsd_and_pspoll(struct ieee80211_rx_data *rx)
  {
  	struct ieee80211_sub_if_data *sdata = rx->sdata;
  	struct ieee80211_hdr *hdr = (void *)rx->skb->data;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
  	int tid, ac;
  
  	if (!rx->sta || !(status->rx_flags & IEEE80211_RX_RA_MATCH))
  		return RX_CONTINUE;
  
  	if (sdata->vif.type != NL80211_IFTYPE_AP &&
  	    sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
  		return RX_CONTINUE;
  
  	/*
  	 * The device handles station powersave, so don't do anything about
  	 * uAPSD and PS-Poll frames (the latter shouldn't even come up from
  	 * it to mac80211 since they're handled.)
  	 */
  	if (sdata->local->hw.flags & IEEE80211_HW_AP_LINK_PS)
  		return RX_CONTINUE;
  
  	/*
  	 * Don't do anything if the station isn't already asleep. In
  	 * the uAPSD case, the station will probably be marked asleep,
  	 * in the PS-Poll case the station must be confused ...
  	 */
  	if (!test_sta_flag(rx->sta, WLAN_STA_PS_STA))
  		return RX_CONTINUE;
  
  	if (unlikely(ieee80211_is_pspoll(hdr->frame_control))) {
  		if (!test_sta_flag(rx->sta, WLAN_STA_SP)) {
  			if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
  				ieee80211_sta_ps_deliver_poll_response(rx->sta);
  			else
  				set_sta_flag(rx->sta, WLAN_STA_PSPOLL);
  		}
  
  		/* Free PS Poll skb here instead of returning RX_DROP that would
  		 * count as an dropped frame. */
  		dev_kfree_skb(rx->skb);
  
  		return RX_QUEUED;
  	} else if (!ieee80211_has_morefrags(hdr->frame_control) &&
  		   !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
  		   ieee80211_has_pm(hdr->frame_control) &&
  		   (ieee80211_is_data_qos(hdr->frame_control) ||
  		    ieee80211_is_qos_nullfunc(hdr->frame_control))) {
  		tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
  		ac = ieee802_1d_to_ac[tid & 7];
  
  		/*
  		 * If this AC is not trigger-enabled do nothing.
  		 *
  		 * NB: This could/should check a separate bitmap of trigger-
  		 * enabled queues, but for now we only implement uAPSD w/o
  		 * TSPEC changes to the ACs, so they're always the same.
  		 */
  		if (!(rx->sta->sta.uapsd_queues & BIT(ac)))
  			return RX_CONTINUE;
  
  		/* if we are in a service period, do nothing */
  		if (test_sta_flag(rx->sta, WLAN_STA_SP))
  			return RX_CONTINUE;
  
  		if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
  			ieee80211_sta_ps_deliver_uapsd(rx->sta);
  		else
  			set_sta_flag(rx->sta, WLAN_STA_UAPSD);
  	}
  
  	return RX_CONTINUE;
  }
  
  static ieee80211_rx_result debug_noinline
  ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
  {
  	struct sta_info *sta = rx->sta;
  	struct sk_buff *skb = rx->skb;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  	int i;
  
  	if (!sta)
  		return RX_CONTINUE;
  
  	/*
  	 * Update last_rx only for IBSS packets which are for the current
  	 * BSSID and for station already AUTHORIZED to avoid keeping the
  	 * current IBSS network alive in cases where other STAs start
  	 * using different BSSID. This will also give the station another
  	 * chance to restart the authentication/authorization in case
  	 * something went wrong the first time.
  	 */
  	if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
  		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
  						NL80211_IFTYPE_ADHOC);
  		if (ether_addr_equal(bssid, rx->sdata->u.ibss.bssid) &&
  		    test_sta_flag(sta, WLAN_STA_AUTHORIZED)) {
  			sta->last_rx = jiffies;
  			if (ieee80211_is_data(hdr->frame_control)) {
  				sta->last_rx_rate_idx = status->rate_idx;
  				sta->last_rx_rate_flag = status->flag;
  				sta->last_rx_rate_vht_nss = status->vht_nss;
  			}
  		}
  	} else if (!is_multicast_ether_addr(hdr->addr1)) {
  		/*
  		 * Mesh beacons will update last_rx when if they are found to
  		 * match the current local configuration when processed.
  		 */
  		sta->last_rx = jiffies;
  		if (ieee80211_is_data(hdr->frame_control)) {
  			sta->last_rx_rate_idx = status->rate_idx;
  			sta->last_rx_rate_flag = status->flag;
  			sta->last_rx_rate_vht_nss = status->vht_nss;
  		}
  	}
  
  	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
  		return RX_CONTINUE;
  
  	if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
  		ieee80211_sta_rx_notify(rx->sdata, hdr);
  
  	sta->rx_fragments++;
  	sta->rx_bytes += rx->skb->len;
  	if (!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
  		sta->last_signal = status->signal;
  		ewma_add(&sta->avg_signal, -status->signal);
  	}
  
  	if (status->chains) {
  		sta->chains = status->chains;
  		for (i = 0; i < ARRAY_SIZE(status->chain_signal); i++) {
  			int signal = status->chain_signal[i];
  
  			if (!(status->chains & BIT(i)))
  				continue;
  
  			sta->chain_signal_last[i] = signal;
  			ewma_add(&sta->chain_signal_avg[i], -signal);
  		}
  	}
  
  	/*
  	 * Change STA power saving mode only at the end of a frame
  	 * exchange sequence.
  	 */
  	if (!(sta->local->hw.flags & IEEE80211_HW_AP_LINK_PS) &&
  	    !ieee80211_has_morefrags(hdr->frame_control) &&
  	    !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
  	    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
  	     rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
  		if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
  			/*
  			 * Ignore doze->wake transitions that are
  			 * indicated by non-data frames, the standard
  			 * is unclear here, but for example going to
  			 * PS mode and then scanning would cause a
  			 * doze->wake transition for the probe request,
  			 * and that is clearly undesirable.
  			 */
  			if (ieee80211_is_data(hdr->frame_control) &&
  			    !ieee80211_has_pm(hdr->frame_control))
  				sta_ps_end(sta);
  		} else {
  			if (ieee80211_has_pm(hdr->frame_control))
  				sta_ps_start(sta);
  		}
  	}
  
  	/* mesh power save support */
  	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
  		ieee80211_mps_rx_h_sta_process(sta, hdr);
  
  	/*
  	 * Drop (qos-)data::nullfunc frames silently, since they
  	 * are used only to control station power saving mode.
  	 */
  	if (ieee80211_is_nullfunc(hdr->frame_control) ||
  	    ieee80211_is_qos_nullfunc(hdr->frame_control)) {
  		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
  
  		/*
  		 * If we receive a 4-addr nullfunc frame from a STA
  		 * that was not moved to a 4-addr STA vlan yet send
  		 * the event to userspace and for older hostapd drop
  		 * the frame to the monitor interface.
  		 */
  		if (ieee80211_has_a4(hdr->frame_control) &&
  		    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
  		     (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
  		      !rx->sdata->u.vlan.sta))) {
  			if (!test_and_set_sta_flag(sta, WLAN_STA_4ADDR_EVENT))
  				cfg80211_rx_unexpected_4addr_frame(
  					rx->sdata->dev, sta->sta.addr,
  					GFP_ATOMIC);
  			return RX_DROP_MONITOR;
  		}
  		/*
  		 * Update counter and free packet here to avoid
  		 * counting this as a dropped packed.
  		 */
  		sta->rx_packets++;
  		dev_kfree_skb(rx->skb);
  		return RX_QUEUED;
  	}
  
  	return RX_CONTINUE;
  } /* ieee80211_rx_h_sta_process */
  
  static ieee80211_rx_result debug_noinline
  ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
  {
  	struct sk_buff *skb = rx->skb;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  	int keyidx;
  	int hdrlen;
  	ieee80211_rx_result result = RX_DROP_UNUSABLE;
  	struct ieee80211_key *sta_ptk = NULL;
  	int mmie_keyidx = -1;
  	__le16 fc;
  	const struct ieee80211_cipher_scheme *cs = NULL;
  
  	/*
  	 * Key selection 101
  	 *
  	 * There are four types of keys:
  	 *  - GTK (group keys)
  	 *  - IGTK (group keys for management frames)
  	 *  - PTK (pairwise keys)
  	 *  - STK (station-to-station pairwise keys)
  	 *
  	 * When selecting a key, we have to distinguish between multicast
  	 * (including broadcast) and unicast frames, the latter can only
  	 * use PTKs and STKs while the former always use GTKs and IGTKs.
  	 * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
  	 * unicast frames can also use key indices like GTKs. Hence, if we
  	 * don't have a PTK/STK we check the key index for a WEP key.
  	 *
  	 * Note that in a regular BSS, multicast frames are sent by the
  	 * AP only, associated stations unicast the frame to the AP first
  	 * which then multicasts it on their behalf.
  	 *
  	 * There is also a slight problem in IBSS mode: GTKs are negotiated
  	 * with each station, that is something we don't currently handle.
  	 * The spec seems to expect that one negotiates the same key with
  	 * every station but there's no such requirement; VLANs could be
  	 * possible.
  	 */
  
  	/*
  	 * No point in finding a key and decrypting if the frame is neither
  	 * addressed to us nor a multicast frame.
  	 */
  	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
  		return RX_CONTINUE;
  
  	/* start without a key */
  	rx->key = NULL;
  	fc = hdr->frame_control;
  
  	if (rx->sta) {
  		int keyid = rx->sta->ptk_idx;
  
  		if (ieee80211_has_protected(fc) && rx->sta->cipher_scheme) {
  			cs = rx->sta->cipher_scheme;
  			keyid = iwl80211_get_cs_keyid(cs, rx->skb);
  			if (unlikely(keyid < 0))
  				return RX_DROP_UNUSABLE;
  		}
  		sta_ptk = rcu_dereference(rx->sta->ptk[keyid]);
  	}
  
  	if (!ieee80211_has_protected(fc))
  		mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
  
  	if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
  		rx->key = sta_ptk;
  		if ((status->flag & RX_FLAG_DECRYPTED) &&
  		    (status->flag & RX_FLAG_IV_STRIPPED))
  			return RX_CONTINUE;
  		/* Skip decryption if the frame is not protected. */
  		if (!ieee80211_has_protected(fc))
  			return RX_CONTINUE;
  	} else if (mmie_keyidx >= 0) {
  		/* Broadcast/multicast robust management frame / BIP */
  		if ((status->flag & RX_FLAG_DECRYPTED) &&
  		    (status->flag & RX_FLAG_IV_STRIPPED))
  			return RX_CONTINUE;
  
  		if (mmie_keyidx < NUM_DEFAULT_KEYS ||
  		    mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
  			return RX_DROP_MONITOR; /* unexpected BIP keyidx */
  		if (rx->sta)
  			rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
  		if (!rx->key)
  			rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
  	} else if (!ieee80211_has_protected(fc)) {
  		/*
  		 * The frame was not protected, so skip decryption. However, we
  		 * need to set rx->key if there is a key that could have been
  		 * used so that the frame may be dropped if encryption would
  		 * have been expected.
  		 */
  		struct ieee80211_key *key = NULL;
  		struct ieee80211_sub_if_data *sdata = rx->sdata;
  		int i;
  
  		if (ieee80211_is_mgmt(fc) &&
  		    is_multicast_ether_addr(hdr->addr1) &&
  		    (key = rcu_dereference(rx->sdata->default_mgmt_key)))
  			rx->key = key;
  		else {
  			if (rx->sta) {
  				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
  					key = rcu_dereference(rx->sta->gtk[i]);
  					if (key)
  						break;
  				}
  			}
  			if (!key) {
  				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
  					key = rcu_dereference(sdata->keys[i]);
  					if (key)
  						break;
  				}
  			}
  			if (key)
  				rx->key = key;
  		}
  		return RX_CONTINUE;
  	} else {
  		u8 keyid;
  
  		/*
  		 * The device doesn't give us the IV so we won't be
  		 * able to look up the key. That's ok though, we
  		 * don't need to decrypt the frame, we just won't
  		 * be able to keep statistics accurate.
  		 * Except for key threshold notifications, should
  		 * we somehow allow the driver to tell us which key
  		 * the hardware used if this flag is set?
  		 */
  		if ((status->flag & RX_FLAG_DECRYPTED) &&
  		    (status->flag & RX_FLAG_IV_STRIPPED))
  			return RX_CONTINUE;
  
  		hdrlen = ieee80211_hdrlen(fc);
  
  		if (cs) {
  			keyidx = iwl80211_get_cs_keyid(cs, rx->skb);
  
  			if (unlikely(keyidx < 0))
  				return RX_DROP_UNUSABLE;
  		} else {
  			if (rx->skb->len < 8 + hdrlen)
  				return RX_DROP_UNUSABLE; /* TODO: count this? */
  			/*
  			 * no need to call ieee80211_wep_get_keyidx,
  			 * it verifies a bunch of things we've done already
  			 */
  			skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
  			keyidx = keyid >> 6;
  		}
  
  		/* check per-station GTK first, if multicast packet */
  		if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
  			rx->key = rcu_dereference(rx->sta->gtk[keyidx]);
  
  		/* if not found, try default key */
  		if (!rx->key) {
  			rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
  
  			/*
  			 * RSNA-protected unicast frames should always be
  			 * sent with pairwise or station-to-station keys,
  			 * but for WEP we allow using a key index as well.
  			 */
  			if (rx->key &&
  			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
  			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
  			    !is_multicast_ether_addr(hdr->addr1))
  				rx->key = NULL;
  		}
  	}
  
  	if (rx->key) {
  		if (unlikely(rx->key->flags & KEY_FLAG_TAINTED))
  			return RX_DROP_MONITOR;
  
  		rx->key->tx_rx_count++;
  		/* TODO: add threshold stuff again */
  	} else {
  		return RX_DROP_MONITOR;
  	}
  
  	switch (rx->key->conf.cipher) {
  	case WLAN_CIPHER_SUITE_WEP40:
  	case WLAN_CIPHER_SUITE_WEP104:
  		result = ieee80211_crypto_wep_decrypt(rx);
  		break;
  	case WLAN_CIPHER_SUITE_TKIP:
  		result = ieee80211_crypto_tkip_decrypt(rx);
  		break;
  	case WLAN_CIPHER_SUITE_CCMP:
  		result = ieee80211_crypto_ccmp_decrypt(rx);
  		break;
  	case WLAN_CIPHER_SUITE_AES_CMAC:
  		result = ieee80211_crypto_aes_cmac_decrypt(rx);
  		break;
  	default:
  		result = ieee80211_crypto_hw_decrypt(rx);
  	}
  
  	/* the hdr variable is invalid after the decrypt handlers */
  
  	/* either the frame has been decrypted or will be dropped */
  	status->flag |= RX_FLAG_DECRYPTED;
  
  	return result;
  }
  
  static inline struct ieee80211_fragment_entry *
  ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
  			 unsigned int frag, unsigned int seq, int rx_queue,
  			 struct sk_buff **skb)
  {
  	struct ieee80211_fragment_entry *entry;
  
  	entry = &sdata->fragments[sdata->fragment_next++];
  	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
  		sdata->fragment_next = 0;
  
  	if (!skb_queue_empty(&entry->skb_list))
  		__skb_queue_purge(&entry->skb_list);
  
  	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
  	*skb = NULL;
  	entry->first_frag_time = jiffies;
  	entry->seq = seq;
  	entry->rx_queue = rx_queue;
  	entry->last_frag = frag;
  	entry->ccmp = 0;
  	entry->extra_len = 0;
  
  	return entry;
  }
  
  static inline struct ieee80211_fragment_entry *
  ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
  			  unsigned int frag, unsigned int seq,
  			  int rx_queue, struct ieee80211_hdr *hdr)
  {
  	struct ieee80211_fragment_entry *entry;
  	int i, idx;
  
  	idx = sdata->fragment_next;
  	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
  		struct ieee80211_hdr *f_hdr;
  
  		idx--;
  		if (idx < 0)
  			idx = IEEE80211_FRAGMENT_MAX - 1;
  
  		entry = &sdata->fragments[idx];
  		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
  		    entry->rx_queue != rx_queue ||
  		    entry->last_frag + 1 != frag)
  			continue;
  
  		f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
  
  		/*
  		 * Check ftype and addresses are equal, else check next fragment
  		 */
  		if (((hdr->frame_control ^ f_hdr->frame_control) &
  		     cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
  		    !ether_addr_equal(hdr->addr1, f_hdr->addr1) ||
  		    !ether_addr_equal(hdr->addr2, f_hdr->addr2))
  			continue;
  
  		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
  			__skb_queue_purge(&entry->skb_list);
  			continue;
  		}
  		return entry;
  	}
  
  	return NULL;
  }
  
  static ieee80211_rx_result debug_noinline
  ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
  {
  	struct ieee80211_hdr *hdr;
  	u16 sc;
  	__le16 fc;
  	unsigned int frag, seq;
  	struct ieee80211_fragment_entry *entry;
  	struct sk_buff *skb;
  	struct ieee80211_rx_status *status;
  
  	hdr = (struct ieee80211_hdr *)rx->skb->data;
  	fc = hdr->frame_control;
  
  	if (ieee80211_is_ctl(fc))
  		return RX_CONTINUE;
  
  	sc = le16_to_cpu(hdr->seq_ctrl);
  	frag = sc & IEEE80211_SCTL_FRAG;
  
  	if (is_multicast_ether_addr(hdr->addr1)) {
  		rx->local->dot11MulticastReceivedFrameCount++;
  		goto out_no_led;
  	}
  
  	if (likely(!ieee80211_has_morefrags(fc) && frag == 0))
  		goto out;
  
  	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
  
  	if (skb_linearize(rx->skb))
  		return RX_DROP_UNUSABLE;
  
  	/*
  	 *  skb_linearize() might change the skb->data and
  	 *  previously cached variables (in this case, hdr) need to
  	 *  be refreshed with the new data.
  	 */
  	hdr = (struct ieee80211_hdr *)rx->skb->data;
  	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
  
  	if (frag == 0) {
  		/* This is the first fragment of a new frame. */
  		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
  						 rx->seqno_idx, &(rx->skb));
  		if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
  		    ieee80211_has_protected(fc)) {
  			int queue = rx->security_idx;
  			/* Store CCMP PN so that we can verify that the next
  			 * fragment has a sequential PN value. */
  			entry->ccmp = 1;
  			memcpy(entry->last_pn,
  			       rx->key->u.ccmp.rx_pn[queue],
  			       IEEE80211_CCMP_PN_LEN);
  		}
  		return RX_QUEUED;
  	}
  
  	/* This is a fragment for a frame that should already be pending in
  	 * fragment cache. Add this fragment to the end of the pending entry.
  	 */
  	entry = ieee80211_reassemble_find(rx->sdata, frag, seq,
  					  rx->seqno_idx, hdr);
  	if (!entry) {
  		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
  		return RX_DROP_MONITOR;
  	}
  
  	/* Verify that MPDUs within one MSDU have sequential PN values.
  	 * (IEEE 802.11i, 8.3.3.4.5) */
  	if (entry->ccmp) {
  		int i;
  		u8 pn[IEEE80211_CCMP_PN_LEN], *rpn;
  		int queue;
  		if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP)
  			return RX_DROP_UNUSABLE;
  		memcpy(pn, entry->last_pn, IEEE80211_CCMP_PN_LEN);
  		for (i = IEEE80211_CCMP_PN_LEN - 1; i >= 0; i--) {
  			pn[i]++;
  			if (pn[i])
  				break;
  		}
  		queue = rx->security_idx;
  		rpn = rx->key->u.ccmp.rx_pn[queue];
  		if (memcmp(pn, rpn, IEEE80211_CCMP_PN_LEN))
  			return RX_DROP_UNUSABLE;
  		memcpy(entry->last_pn, pn, IEEE80211_CCMP_PN_LEN);
  	}
  
  	skb_pull(rx->skb, ieee80211_hdrlen(fc));
  	__skb_queue_tail(&entry->skb_list, rx->skb);
  	entry->last_frag = frag;
  	entry->extra_len += rx->skb->len;
  	if (ieee80211_has_morefrags(fc)) {
  		rx->skb = NULL;
  		return RX_QUEUED;
  	}
  
  	rx->skb = __skb_dequeue(&entry->skb_list);
  	if (skb_tailroom(rx->skb) < entry->extra_len) {
  		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
  		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
  					      GFP_ATOMIC))) {
  			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
  			__skb_queue_purge(&entry->skb_list);
  			return RX_DROP_UNUSABLE;
  		}
  	}
  	while ((skb = __skb_dequeue(&entry->skb_list))) {
  		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
  		dev_kfree_skb(skb);
  	}
  
  	/* Complete frame has been reassembled - process it now */
  	status = IEEE80211_SKB_RXCB(rx->skb);
  	status->rx_flags |= IEEE80211_RX_FRAGMENTED;
  
   out:
  	ieee80211_led_rx(rx->local);
   out_no_led:
  	if (rx->sta)
  		rx->sta->rx_packets++;
  	return RX_CONTINUE;
  }
  
  static int ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
  {
  	if (unlikely(!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_AUTHORIZED)))
  		return -EACCES;
  
  	return 0;
  }
  
  static int ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
  {
  	struct sk_buff *skb = rx->skb;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  
  	/*
  	 * Pass through unencrypted frames if the hardware has
  	 * decrypted them already.
  	 */
  	if (status->flag & RX_FLAG_DECRYPTED)
  		return 0;
  
  	/* Drop unencrypted frames if key is set. */
  	if (unlikely(!ieee80211_has_protected(fc) &&
  		     !ieee80211_is_nullfunc(fc) &&
  		     ieee80211_is_data(fc) &&
  		     (rx->key || rx->sdata->drop_unencrypted)))
  		return -EACCES;
  
  	return 0;
  }
  
  static int ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
  {
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
  	__le16 fc = hdr->frame_control;
  
  	/*
  	 * Pass through unencrypted frames if the hardware has
  	 * decrypted them already.
  	 */
  	if (status->flag & RX_FLAG_DECRYPTED)
  		return 0;
  
  	if (rx->sta && test_sta_flag(rx->sta, WLAN_STA_MFP)) {
  		if (unlikely(!ieee80211_has_protected(fc) &&
  			     ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
  			     rx->key)) {
  			if (ieee80211_is_deauth(fc) ||
  			    ieee80211_is_disassoc(fc))
  				cfg80211_rx_unprot_mlme_mgmt(rx->sdata->dev,
  							     rx->skb->data,
  							     rx->skb->len);
  			return -EACCES;
  		}
  		/* BIP does not use Protected field, so need to check MMIE */
  		if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
  			     ieee80211_get_mmie_keyidx(rx->skb) < 0)) {
  			if (ieee80211_is_deauth(fc) ||
  			    ieee80211_is_disassoc(fc))
  				cfg80211_rx_unprot_mlme_mgmt(rx->sdata->dev,
  							     rx->skb->data,
  							     rx->skb->len);
  			return -EACCES;
  		}
  		/*
  		 * When using MFP, Action frames are not allowed prior to
  		 * having configured keys.
  		 */
  		if (unlikely(ieee80211_is_action(fc) && !rx->key &&
  			     ieee80211_is_robust_mgmt_frame(
  				     (struct ieee80211_hdr *) rx->skb->data)))
  			return -EACCES;
  	}
  
  	return 0;
  }
  
  static int
  __ieee80211_data_to_8023(struct ieee80211_rx_data *rx, bool *port_control)
  {
  	struct ieee80211_sub_if_data *sdata = rx->sdata;
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
  	bool check_port_control = false;
  	struct ethhdr *ehdr;
  	int ret;
  
  	*port_control = false;
  	if (ieee80211_has_a4(hdr->frame_control) &&
  	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
  		return -1;
  
  	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
  	    !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control)) {
  
  		if (!sdata->u.mgd.use_4addr)
  			return -1;
  		else
  			check_port_control = true;
  	}
  
  	if (is_multicast_ether_addr(hdr->addr1) &&
  	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
  		return -1;
  
  	ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
  	if (ret < 0)
  		return ret;
  
  	ehdr = (struct ethhdr *) rx->skb->data;
  	if (ehdr->h_proto == rx->sdata->control_port_protocol)
  		*port_control = true;
  	else if (check_port_control)
  		return -1;
  
  	return 0;
  }
  
  /*
   * requires that rx->skb is a frame with ethernet header
   */
  static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
  {
  	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
  		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
  	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
  
  	/*
  	 * Allow EAPOL frames to us/the PAE group address regardless
  	 * of whether the frame was encrypted or not.
  	 */
  	if (ehdr->h_proto == rx->sdata->control_port_protocol &&
  	    (ether_addr_equal(ehdr->h_dest, rx->sdata->vif.addr) ||
  	     ether_addr_equal(ehdr->h_dest, pae_group_addr)))
  		return true;
  
  	if (ieee80211_802_1x_port_control(rx) ||
  	    ieee80211_drop_unencrypted(rx, fc))
  		return false;
  
  	return true;
  }
  
  /*
   * requires that rx->skb is a frame with ethernet header
   */
  static void
  ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
  {
  	struct ieee80211_sub_if_data *sdata = rx->sdata;
  	struct net_device *dev = sdata->dev;
  	struct sk_buff *skb, *xmit_skb;
  	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
  	struct sta_info *dsta;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
  
  	skb = rx->skb;
  	xmit_skb = NULL;
  
  	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
  	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
  	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
  	    (status->rx_flags & IEEE80211_RX_RA_MATCH) &&
  	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
  		if (is_multicast_ether_addr(ehdr->h_dest)) {
  			/*
  			 * send multicast frames both to higher layers in
  			 * local net stack and back to the wireless medium
  			 */
  			xmit_skb = skb_copy(skb, GFP_ATOMIC);
  			if (!xmit_skb)
  				net_info_ratelimited("%s: failed to clone multicast frame
  ",
  						    dev->name);
  		} else {
  			dsta = sta_info_get(sdata, skb->data);
  			if (dsta) {
  				/*
  				 * The destination station is associated to
  				 * this AP (in this VLAN), so send the frame
  				 * directly to it and do not pass it to local
  				 * net stack.
  				 */
  				xmit_skb = skb;
  				skb = NULL;
  			}
  		}
  	}
  
  #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
  	if (skb) {
  		/* 'align' will only take the values 0 or 2 here since all
  		 * frames are required to be aligned to 2-byte boundaries
  		 * when being passed to mac80211; the code here works just
  		 * as well if that isn't true, but mac80211 assumes it can
  		 * access fields as 2-byte aligned (e.g. for ether_addr_equal)
  		 */
  		int align;
  
  		align = (unsigned long)(skb->data + sizeof(struct ethhdr)) & 3;
  		if (align) {
  			if (WARN_ON(skb_headroom(skb) < 3)) {
  				dev_kfree_skb(skb);
  				skb = NULL;
  			} else {
  				u8 *data = skb->data;
  				size_t len = skb_headlen(skb);
  				skb->data -= align;
  				memmove(skb->data, data, len);
  				skb_set_tail_pointer(skb, len);
  			}
  		}
  	}
  #endif
  
  	if (skb) {
  		/* deliver to local stack */
  		skb->protocol = eth_type_trans(skb, dev);
  		memset(skb->cb, 0, sizeof(skb->cb));
  		netif_receive_skb(skb);
  	}
  
  	if (xmit_skb) {
  		/*
  		 * Send to wireless media and increase priority by 256 to
  		 * keep the received priority instead of reclassifying
  		 * the frame (see cfg80211_classify8021d).
  		 */
  		xmit_skb->priority += 256;
  		xmit_skb->protocol = htons(ETH_P_802_3);
  		skb_reset_network_header(xmit_skb);
  		skb_reset_mac_header(xmit_skb);
  		dev_queue_xmit(xmit_skb);
  	}
  }
  
  static ieee80211_rx_result debug_noinline
  ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
  {
  	struct net_device *dev = rx->sdata->dev;
  	struct sk_buff *skb = rx->skb;
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  	__le16 fc = hdr->frame_control;
  	struct sk_buff_head frame_list;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
  
  	if (unlikely(!ieee80211_is_data(fc)))
  		return RX_CONTINUE;
  
  	if (unlikely(!ieee80211_is_data_present(fc)))
  		return RX_DROP_MONITOR;
  
  	if (!(status->rx_flags & IEEE80211_RX_AMSDU))
  		return RX_CONTINUE;
  
  	if (ieee80211_has_a4(hdr->frame_control) &&
  	    rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
  	    !rx->sdata->u.vlan.sta)
  		return RX_DROP_UNUSABLE;
  
  	if (is_multicast_ether_addr(hdr->addr1) &&
  	    ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
  	      rx->sdata->u.vlan.sta) ||
  	     (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
  	      rx->sdata->u.mgd.use_4addr)))
  		return RX_DROP_UNUSABLE;
  
  	skb->dev = dev;
  	__skb_queue_head_init(&frame_list);
  
  	if (skb_linearize(skb))
  		return RX_DROP_UNUSABLE;
  
  	ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
  				 rx->sdata->vif.type,
  				 rx->local->hw.extra_tx_headroom, true);
  
  	while (!skb_queue_empty(&frame_list)) {
  		rx->skb = __skb_dequeue(&frame_list);
  
  		if (!ieee80211_frame_allowed(rx, fc)) {
  			dev_kfree_skb(rx->skb);
  			continue;
  		}
  		dev->stats.rx_packets++;
  		dev->stats.rx_bytes += rx->skb->len;
  
  		ieee80211_deliver_skb(rx);
  	}
  
  	return RX_QUEUED;
  }
  
  #ifdef CONFIG_MAC80211_MESH
  static ieee80211_rx_result
  ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
  {
  	struct ieee80211_hdr *fwd_hdr, *hdr;
  	struct ieee80211_tx_info *info;
  	struct ieee80211s_hdr *mesh_hdr;
  	struct sk_buff *skb = rx->skb, *fwd_skb;
  	struct ieee80211_local *local = rx->local;
  	struct ieee80211_sub_if_data *sdata = rx->sdata;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
  	u16 q, hdrlen;
  
  	hdr = (struct ieee80211_hdr *) skb->data;
  	hdrlen = ieee80211_hdrlen(hdr->frame_control);
  
  	/* make sure fixed part of mesh header is there, also checks skb len */
  	if (!pskb_may_pull(rx->skb, hdrlen + 6))
  		return RX_DROP_MONITOR;
  
  	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
  
  	/* make sure full mesh header is there, also checks skb len */
  	if (!pskb_may_pull(rx->skb,
  			   hdrlen + ieee80211_get_mesh_hdrlen(mesh_hdr)))
  		return RX_DROP_MONITOR;
  
  	/* reload pointers */
  	hdr = (struct ieee80211_hdr *) skb->data;
  	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
  
  	/* frame is in RMC, don't forward */
  	if (ieee80211_is_data(hdr->frame_control) &&
  	    is_multicast_ether_addr(hdr->addr1) &&
  	    mesh_rmc_check(rx->sdata, hdr->addr3, mesh_hdr))
  		return RX_DROP_MONITOR;
  
  	if (!ieee80211_is_data(hdr->frame_control) ||
  	    !(status->rx_flags & IEEE80211_RX_RA_MATCH))
  		return RX_CONTINUE;
  
  	if (!mesh_hdr->ttl)
  		return RX_DROP_MONITOR;
  
  	if (mesh_hdr->flags & MESH_FLAGS_AE) {
  		struct mesh_path *mppath;
  		char *proxied_addr;
  		char *mpp_addr;
  
  		if (is_multicast_ether_addr(hdr->addr1)) {
  			mpp_addr = hdr->addr3;
  			proxied_addr = mesh_hdr->eaddr1;
  		} else if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6) {
  			/* has_a4 already checked in ieee80211_rx_mesh_check */
  			mpp_addr = hdr->addr4;
  			proxied_addr = mesh_hdr->eaddr2;
  		} else {
  			return RX_DROP_MONITOR;
  		}
  
  		rcu_read_lock();
  		mppath = mpp_path_lookup(sdata, proxied_addr);
  		if (!mppath) {
  			mpp_path_add(sdata, proxied_addr, mpp_addr);
  		} else {
  			spin_lock_bh(&mppath->state_lock);
  			if (!ether_addr_equal(mppath->mpp, mpp_addr))
  				memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
  			spin_unlock_bh(&mppath->state_lock);
  		}
  		rcu_read_unlock();
  	}
  
  	/* Frame has reached destination.  Don't forward */
  	if (!is_multicast_ether_addr(hdr->addr1) &&
  	    ether_addr_equal(sdata->vif.addr, hdr->addr3))
  		return RX_CONTINUE;
  
  	q = ieee80211_select_queue_80211(sdata, skb, hdr);
  	if (ieee80211_queue_stopped(&local->hw, q)) {
  		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_congestion);
  		return RX_DROP_MONITOR;
  	}
  	skb_set_queue_mapping(skb, q);
  
  	if (!--mesh_hdr->ttl) {
  		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_ttl);
  		goto out;
  	}
  
  	if (!ifmsh->mshcfg.dot11MeshForwarding)
  		goto out;
  
  	fwd_skb = skb_copy(skb, GFP_ATOMIC);
  	if (!fwd_skb) {
  		net_info_ratelimited("%s: failed to clone mesh frame
  ",
  				    sdata->name);
  		goto out;
  	}
  
  	fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
  	fwd_hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_RETRY);
  	info = IEEE80211_SKB_CB(fwd_skb);
  	memset(info, 0, sizeof(*info));
  	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
  	info->control.vif = &rx->sdata->vif;
  	info->control.jiffies = jiffies;
  	if (is_multicast_ether_addr(fwd_hdr->addr1)) {
  		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_mcast);
  		memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
  		/* update power mode indication when forwarding */
  		ieee80211_mps_set_frame_flags(sdata, NULL, fwd_hdr);
  	} else if (!mesh_nexthop_lookup(sdata, fwd_skb)) {
  		/* mesh power mode flags updated in mesh_nexthop_lookup */
  		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_unicast);
  	} else {
  		/* unable to resolve next hop */
  		mesh_path_error_tx(sdata, ifmsh->mshcfg.element_ttl,
  				   fwd_hdr->addr3, 0,
  				   WLAN_REASON_MESH_PATH_NOFORWARD,
  				   fwd_hdr->addr2);
  		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_no_route);
  		kfree_skb(fwd_skb);
  		return RX_DROP_MONITOR;
  	}
  
  	IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_frames);
  	ieee80211_add_pending_skb(local, fwd_skb);
   out:
  	if (is_multicast_ether_addr(hdr->addr1) ||
  	    sdata->dev->flags & IFF_PROMISC)
  		return RX_CONTINUE;
  	else
  		return RX_DROP_MONITOR;
  }
  #endif
  
  static ieee80211_rx_result debug_noinline
  ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
  {
  	struct ieee80211_sub_if_data *sdata = rx->sdata;
  	struct ieee80211_local *local = rx->local;
  	struct net_device *dev = sdata->dev;
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
  	__le16 fc = hdr->frame_control;
  	bool port_control;
  	int err;
  
  	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
  		return RX_CONTINUE;
  
  	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
  		return RX_DROP_MONITOR;
  
  	/*
  	 * Send unexpected-4addr-frame event to hostapd. For older versions,
  	 * also drop the frame to cooked monitor interfaces.
  	 */
  	if (ieee80211_has_a4(hdr->frame_control) &&
  	    sdata->vif.type == NL80211_IFTYPE_AP) {
  		if (rx->sta &&
  		    !test_and_set_sta_flag(rx->sta, WLAN_STA_4ADDR_EVENT))
  			cfg80211_rx_unexpected_4addr_frame(
  				rx->sdata->dev, rx->sta->sta.addr, GFP_ATOMIC);
  		return RX_DROP_MONITOR;
  	}
  
  	err = __ieee80211_data_to_8023(rx, &port_control);
  	if (unlikely(err))
  		return RX_DROP_UNUSABLE;
  
  	if (!ieee80211_frame_allowed(rx, fc))
  		return RX_DROP_MONITOR;
  
  	if (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
  	    unlikely(port_control) && sdata->bss) {
  		sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
  				     u.ap);
  		dev = sdata->dev;
  		rx->sdata = sdata;
  	}
  
  	rx->skb->dev = dev;
  
  	dev->stats.rx_packets++;
  	dev->stats.rx_bytes += rx->skb->len;
  
  	if (local->ps_sdata && local->hw.conf.dynamic_ps_timeout > 0 &&
  	    !is_multicast_ether_addr(
  		    ((struct ethhdr *)rx->skb->data)->h_dest) &&
  	    (!local->scanning &&
  	     !test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))) {
  			mod_timer(&local->dynamic_ps_timer, jiffies +
  			 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
  	}
  
  	ieee80211_deliver_skb(rx);
  
  	return RX_QUEUED;
  }
  
  static ieee80211_rx_result debug_noinline
  ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
  {
  	struct sk_buff *skb = rx->skb;
  	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
  	struct tid_ampdu_rx *tid_agg_rx;
  	u16 start_seq_num;
  	u16 tid;
  
  	if (likely(!ieee80211_is_ctl(bar->frame_control)))
  		return RX_CONTINUE;
  
  	if (ieee80211_is_back_req(bar->frame_control)) {
  		struct {
  			__le16 control, start_seq_num;
  		} __packed bar_data;
  
  		if (!rx->sta)
  			return RX_DROP_MONITOR;
  
  		if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
  				  &bar_data, sizeof(bar_data)))
  			return RX_DROP_MONITOR;
  
  		tid = le16_to_cpu(bar_data.control) >> 12;
  
  		tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
  		if (!tid_agg_rx)
  			return RX_DROP_MONITOR;
  
  		start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
  
  		/* reset session timer */
  		if (tid_agg_rx->timeout)
  			mod_timer(&tid_agg_rx->session_timer,
  				  TU_TO_EXP_TIME(tid_agg_rx->timeout));
  
  		spin_lock(&tid_agg_rx->reorder_lock);
  		/* release stored frames up to start of BAR */
  		ieee80211_release_reorder_frames(rx->sdata, tid_agg_rx,
  						 start_seq_num, frames);
  		spin_unlock(&tid_agg_rx->reorder_lock);
  
  		kfree_skb(skb);
  		return RX_QUEUED;
  	}
  
  	/*
  	 * After this point, we only want management frames,
  	 * so we can drop all remaining control frames to
  	 * cooked monitor interfaces.
  	 */
  	return RX_DROP_MONITOR;
  }
  
  static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
  					   struct ieee80211_mgmt *mgmt,
  					   size_t len)
  {
  	struct ieee80211_local *local = sdata->local;
  	struct sk_buff *skb;
  	struct ieee80211_mgmt *resp;
  
  	if (!ether_addr_equal(mgmt->da, sdata->vif.addr)) {
  		/* Not to own unicast address */
  		return;
  	}
  
  	if (!ether_addr_equal(mgmt->sa, sdata->u.mgd.bssid) ||
  	    !ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid)) {
  		/* Not from the current AP or not associated yet. */
  		return;
  	}
  
  	if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
  		/* Too short SA Query request frame */
  		return;
  	}
  
  	skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
  	if (skb == NULL)
  		return;
  
  	skb_reserve(skb, local->hw.extra_tx_headroom);
  	resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
  	memset(resp, 0, 24);
  	memcpy(resp->da, mgmt->sa, ETH_ALEN);
  	memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
  	memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
  	resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
  					  IEEE80211_STYPE_ACTION);
  	skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
  	resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
  	resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
  	memcpy(resp->u.action.u.sa_query.trans_id,
  	       mgmt->u.action.u.sa_query.trans_id,
  	       WLAN_SA_QUERY_TR_ID_LEN);
  
  	ieee80211_tx_skb(sdata, skb);
  }
  
  static ieee80211_rx_result debug_noinline
  ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
  {
  	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
  
  	/*
  	 * From here on, look only at management frames.
  	 * Data and control frames are already handled,
  	 * and unknown (reserved) frames are useless.
  	 */
  	if (rx->skb->len < 24)
  		return RX_DROP_MONITOR;
  
  	if (!ieee80211_is_mgmt(mgmt->frame_control))
  		return RX_DROP_MONITOR;
  
  	if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
  	    ieee80211_is_beacon(mgmt->frame_control) &&
  	    !(rx->flags & IEEE80211_RX_BEACON_REPORTED)) {
  		int sig = 0;
  
  		if (rx->local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  			sig = status->signal;
  
  		cfg80211_report_obss_beacon(rx->local->hw.wiphy,
  					    rx->skb->data, rx->skb->len,
  					    status->freq, sig);
  		rx->flags |= IEEE80211_RX_BEACON_REPORTED;
  	}
  
  	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
  		return RX_DROP_MONITOR;
  
  	if (ieee80211_drop_unencrypted_mgmt(rx))
  		return RX_DROP_UNUSABLE;
  
  	return RX_CONTINUE;
  }
  
  static ieee80211_rx_result debug_noinline
  ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
  {
  	struct ieee80211_local *local = rx->local;
  	struct ieee80211_sub_if_data *sdata = rx->sdata;
  	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
  	int len = rx->skb->len;
  
  	if (!ieee80211_is_action(mgmt->frame_control))
  		return RX_CONTINUE;
  
  	/* drop too small frames */
  	if (len < IEEE80211_MIN_ACTION_SIZE)
  		return RX_DROP_UNUSABLE;
  
  	if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC &&
  	    mgmt->u.action.category != WLAN_CATEGORY_SELF_PROTECTED &&
  	    mgmt->u.action.category != WLAN_CATEGORY_SPECTRUM_MGMT)
  		return RX_DROP_UNUSABLE;
  
  	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
  		return RX_DROP_UNUSABLE;
  
  	switch (mgmt->u.action.category) {
  	case WLAN_CATEGORY_HT:
  		/* reject HT action frames from stations not supporting HT */
  		if (!rx->sta->sta.ht_cap.ht_supported)
  			goto invalid;
  
  		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
  		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
  		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
  		    sdata->vif.type != NL80211_IFTYPE_AP &&
  		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
  			break;
  
  		/* verify action & smps_control/chanwidth are present */
  		if (len < IEEE80211_MIN_ACTION_SIZE + 2)
  			goto invalid;
  
  		switch (mgmt->u.action.u.ht_smps.action) {
  		case WLAN_HT_ACTION_SMPS: {
  			struct ieee80211_supported_band *sband;
  			enum ieee80211_smps_mode smps_mode;
  
  			/* convert to HT capability */
  			switch (mgmt->u.action.u.ht_smps.smps_control) {
  			case WLAN_HT_SMPS_CONTROL_DISABLED:
  				smps_mode = IEEE80211_SMPS_OFF;
  				break;
  			case WLAN_HT_SMPS_CONTROL_STATIC:
  				smps_mode = IEEE80211_SMPS_STATIC;
  				break;
  			case WLAN_HT_SMPS_CONTROL_DYNAMIC:
  				smps_mode = IEEE80211_SMPS_DYNAMIC;
  				break;
  			default:
  				goto invalid;
  			}
  
  			/* if no change do nothing */
  			if (rx->sta->sta.smps_mode == smps_mode)
  				goto handled;
  			rx->sta->sta.smps_mode = smps_mode;
  
  			sband = rx->local->hw.wiphy->bands[status->band];
  
  			rate_control_rate_update(local, sband, rx->sta,
  						 IEEE80211_RC_SMPS_CHANGED);
  			goto handled;
  		}
  		case WLAN_HT_ACTION_NOTIFY_CHANWIDTH: {
  			struct ieee80211_supported_band *sband;
  			u8 chanwidth = mgmt->u.action.u.ht_notify_cw.chanwidth;
  			enum ieee80211_sta_rx_bandwidth new_bw;
  
  			/* If it doesn't support 40 MHz it can't change ... */
  			if (!(rx->sta->sta.ht_cap.cap &
  					IEEE80211_HT_CAP_SUP_WIDTH_20_40))
  				goto handled;
  
  			if (chanwidth == IEEE80211_HT_CHANWIDTH_20MHZ)
  				new_bw = IEEE80211_STA_RX_BW_20;
  			else
  				new_bw = ieee80211_sta_cur_vht_bw(rx->sta);
  
  			if (rx->sta->sta.bandwidth == new_bw)
  				goto handled;
  
  			sband = rx->local->hw.wiphy->bands[status->band];
  
  			rate_control_rate_update(local, sband, rx->sta,
  						 IEEE80211_RC_BW_CHANGED);
  			goto handled;
  		}
  		default:
  			goto invalid;
  		}
  
  		break;
  	case WLAN_CATEGORY_PUBLIC:
  		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
  			goto invalid;
  		if (sdata->vif.type != NL80211_IFTYPE_STATION)
  			break;
  		if (!rx->sta)
  			break;
  		if (!ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid))
  			break;
  		if (mgmt->u.action.u.ext_chan_switch.action_code !=
  				WLAN_PUB_ACTION_EXT_CHANSW_ANN)
  			break;
  		if (len < offsetof(struct ieee80211_mgmt,
  				   u.action.u.ext_chan_switch.variable))
  			goto invalid;
  		goto queue;
  	case WLAN_CATEGORY_VHT:
  		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
  		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
  		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
  		    sdata->vif.type != NL80211_IFTYPE_AP &&
  		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
  			break;
  
  		/* verify action code is present */
  		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
  			goto invalid;
  
  		switch (mgmt->u.action.u.vht_opmode_notif.action_code) {
  		case WLAN_VHT_ACTION_OPMODE_NOTIF: {
  			u8 opmode;
  
  			/* verify opmode is present */
  			if (len < IEEE80211_MIN_ACTION_SIZE + 2)
  				goto invalid;
  
  			opmode = mgmt->u.action.u.vht_opmode_notif.operating_mode;
  
  			ieee80211_vht_handle_opmode(rx->sdata, rx->sta,
  						    opmode, status->band,
  						    false);
  			goto handled;
  		}
  		default:
  			break;
  		}
  		break;
  	case WLAN_CATEGORY_BACK:
  		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
  		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
  		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
  		    sdata->vif.type != NL80211_IFTYPE_AP &&
  		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
  			break;
  
  		/* verify action_code is present */
  		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
  			break;
  
  		switch (mgmt->u.action.u.addba_req.action_code) {
  		case WLAN_ACTION_ADDBA_REQ:
  			if (len < (IEEE80211_MIN_ACTION_SIZE +
  				   sizeof(mgmt->u.action.u.addba_req)))
  				goto invalid;
  			break;
  		case WLAN_ACTION_ADDBA_RESP:
  			if (len < (IEEE80211_MIN_ACTION_SIZE +
  				   sizeof(mgmt->u.action.u.addba_resp)))
  				goto invalid;
  			break;
  		case WLAN_ACTION_DELBA:
  			if (len < (IEEE80211_MIN_ACTION_SIZE +
  				   sizeof(mgmt->u.action.u.delba)))
  				goto invalid;
  			break;
  		default:
  			goto invalid;
  		}
  
  		goto queue;
  	case WLAN_CATEGORY_SPECTRUM_MGMT:
  		/* verify action_code is present */
  		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
  			break;
  
  		switch (mgmt->u.action.u.measurement.action_code) {
  		case WLAN_ACTION_SPCT_MSR_REQ:
  			if (status->band != IEEE80211_BAND_5GHZ)
  				break;
  
  			if (len < (IEEE80211_MIN_ACTION_SIZE +
  				   sizeof(mgmt->u.action.u.measurement)))
  				break;
  
  			if (sdata->vif.type != NL80211_IFTYPE_STATION)
  				break;
  
  			ieee80211_process_measurement_req(sdata, mgmt, len);
  			goto handled;
  		case WLAN_ACTION_SPCT_CHL_SWITCH: {
  			u8 *bssid;
  			if (len < (IEEE80211_MIN_ACTION_SIZE +
  				   sizeof(mgmt->u.action.u.chan_switch)))
  				break;
  
  			if (sdata->vif.type != NL80211_IFTYPE_STATION &&
  			    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
  			    sdata->vif.type != NL80211_IFTYPE_MESH_POINT)
  				break;
  
  			if (sdata->vif.type == NL80211_IFTYPE_STATION)
  				bssid = sdata->u.mgd.bssid;
  			else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
  				bssid = sdata->u.ibss.bssid;
  			else if (sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
  				bssid = mgmt->sa;
  			else
  				break;
  
  			if (!ether_addr_equal(mgmt->bssid, bssid))
  				break;
  
  			goto queue;
  			}
  		}
  		break;
  	case WLAN_CATEGORY_SA_QUERY:
  		if (len < (IEEE80211_MIN_ACTION_SIZE +
  			   sizeof(mgmt->u.action.u.sa_query)))
  			break;
  
  		switch (mgmt->u.action.u.sa_query.action) {
  		case WLAN_ACTION_SA_QUERY_REQUEST:
  			if (sdata->vif.type != NL80211_IFTYPE_STATION)
  				break;
  			ieee80211_process_sa_query_req(sdata, mgmt, len);
  			goto handled;
  		}
  		break;
  	case WLAN_CATEGORY_SELF_PROTECTED:
  		if (len < (IEEE80211_MIN_ACTION_SIZE +
  			   sizeof(mgmt->u.action.u.self_prot.action_code)))
  			break;
  
  		switch (mgmt->u.action.u.self_prot.action_code) {
  		case WLAN_SP_MESH_PEERING_OPEN:
  		case WLAN_SP_MESH_PEERING_CLOSE:
  		case WLAN_SP_MESH_PEERING_CONFIRM:
  			if (!ieee80211_vif_is_mesh(&sdata->vif))
  				goto invalid;
  			if (sdata->u.mesh.user_mpm)
  				/* userspace handles this frame */
  				break;
  			goto queue;
  		case WLAN_SP_MGK_INFORM:
  		case WLAN_SP_MGK_ACK:
  			if (!ieee80211_vif_is_mesh(&sdata->vif))
  				goto invalid;
  			break;
  		}
  		break;
  	case WLAN_CATEGORY_MESH_ACTION:
  		if (len < (IEEE80211_MIN_ACTION_SIZE +
  			   sizeof(mgmt->u.action.u.mesh_action.action_code)))
  			break;
  
  		if (!ieee80211_vif_is_mesh(&sdata->vif))
  			break;
  		if (mesh_action_is_path_sel(mgmt) &&
  		    !mesh_path_sel_is_hwmp(sdata))
  			break;
  		goto queue;
  	}
  
  	return RX_CONTINUE;
  
   invalid:
  	status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
  	/* will return in the next handlers */
  	return RX_CONTINUE;
  
   handled:
  	if (rx->sta)
  		rx->sta->rx_packets++;
  	dev_kfree_skb(rx->skb);
  	return RX_QUEUED;
  
   queue:
  	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
  	skb_queue_tail(&sdata->skb_queue, rx->skb);
  	ieee80211_queue_work(&local->hw, &sdata->work);
  	if (rx->sta)
  		rx->sta->rx_packets++;
  	return RX_QUEUED;
  }
  
  static ieee80211_rx_result debug_noinline
  ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
  {
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
  	int sig = 0;
  
  	/* skip known-bad action frames and return them in the next handler */
  	if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
  		return RX_CONTINUE;
  
  	/*
  	 * Getting here means the kernel doesn't know how to handle
  	 * it, but maybe userspace does ... include returned frames
  	 * so userspace can register for those to know whether ones
  	 * it transmitted were processed or returned.
  	 */
  
  	if (rx->local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  		sig = status->signal;
  
  	if (cfg80211_rx_mgmt(&rx->sdata->wdev, status->freq, sig,
  			     rx->skb->data, rx->skb->len, 0, GFP_ATOMIC)) {
  		if (rx->sta)
  			rx->sta->rx_packets++;
  		dev_kfree_skb(rx->skb);
  		return RX_QUEUED;
  	}
  
  	return RX_CONTINUE;
  }
  
  static ieee80211_rx_result debug_noinline
  ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
  {
  	struct ieee80211_local *local = rx->local;
  	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
  	struct sk_buff *nskb;
  	struct ieee80211_sub_if_data *sdata = rx->sdata;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
  
  	if (!ieee80211_is_action(mgmt->frame_control))
  		return RX_CONTINUE;
  
  	/*
  	 * For AP mode, hostapd is responsible for handling any action
  	 * frames that we didn't handle, including returning unknown
  	 * ones. For all other modes we will return them to the sender,
  	 * setting the 0x80 bit in the action category, as required by
  	 * 802.11-2012 9.24.4.
  	 * Newer versions of hostapd shall also use the management frame
  	 * registration mechanisms, but older ones still use cooked
  	 * monitor interfaces so push all frames there.
  	 */
  	if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
  	    (sdata->vif.type == NL80211_IFTYPE_AP ||
  	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
  		return RX_DROP_MONITOR;
  
  	if (is_multicast_ether_addr(mgmt->da))
  		return RX_DROP_MONITOR;
  
  	/* do not return rejected action frames */
  	if (mgmt->u.action.category & 0x80)
  		return RX_DROP_UNUSABLE;
  
  	nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
  			       GFP_ATOMIC);
  	if (nskb) {
  		struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
  
  		nmgmt->u.action.category |= 0x80;
  		memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
  		memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
  
  		memset(nskb->cb, 0, sizeof(nskb->cb));
  
  		if (rx->sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) {
  			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(nskb);
  
  			info->flags = IEEE80211_TX_CTL_TX_OFFCHAN |
  				      IEEE80211_TX_INTFL_OFFCHAN_TX_OK |
  				      IEEE80211_TX_CTL_NO_CCK_RATE;
  			if (local->hw.flags & IEEE80211_HW_QUEUE_CONTROL)
  				info->hw_queue =
  					local->hw.offchannel_tx_hw_queue;
  		}
  
  		__ieee80211_tx_skb_tid_band(rx->sdata, nskb, 7,
  					    status->band);
  	}
  	dev_kfree_skb(rx->skb);
  	return RX_QUEUED;
  }
  
  static ieee80211_rx_result debug_noinline
  ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
  {
  	struct ieee80211_sub_if_data *sdata = rx->sdata;
  	struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
  	__le16 stype;
  
  	stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
  
  	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
  	    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
  	    sdata->vif.type != NL80211_IFTYPE_STATION)
  		return RX_DROP_MONITOR;
  
  	switch (stype) {
  	case cpu_to_le16(IEEE80211_STYPE_AUTH):
  	case cpu_to_le16(IEEE80211_STYPE_BEACON):
  	case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
  		/* process for all: mesh, mlme, ibss */
  		break;
  	case cpu_to_le16(IEEE80211_STYPE_ASSOC_RESP):
  	case cpu_to_le16(IEEE80211_STYPE_REASSOC_RESP):
  	case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
  	case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
  		if (is_multicast_ether_addr(mgmt->da) &&
  		    !is_broadcast_ether_addr(mgmt->da))
  			return RX_DROP_MONITOR;
  
  		/* process only for station */
  		if (sdata->vif.type != NL80211_IFTYPE_STATION)
  			return RX_DROP_MONITOR;
  		break;
  	case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
  		/* process only for ibss and mesh */
  		if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
  		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT)
  			return RX_DROP_MONITOR;
  		break;
  	default:
  		return RX_DROP_MONITOR;
  	}
  
  	/* queue up frame and kick off work to process it */
  	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
  	skb_queue_tail(&sdata->skb_queue, rx->skb);
  	ieee80211_queue_work(&rx->local->hw, &sdata->work);
  	if (rx->sta)
  		rx->sta->rx_packets++;
  
  	return RX_QUEUED;
  }
  
  /* TODO: use IEEE80211_RX_FRAGMENTED */
  static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
  					struct ieee80211_rate *rate)
  {
  	struct ieee80211_sub_if_data *sdata;
  	struct ieee80211_local *local = rx->local;
  	struct sk_buff *skb = rx->skb, *skb2;
  	struct net_device *prev_dev = NULL;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  	int needed_headroom;
  
  	/*
  	 * If cooked monitor has been processed already, then
  	 * don't do it again. If not, set the flag.
  	 */
  	if (rx->flags & IEEE80211_RX_CMNTR)
  		goto out_free_skb;
  	rx->flags |= IEEE80211_RX_CMNTR;
  
  	/* If there are no cooked monitor interfaces, just free the SKB */
  	if (!local->cooked_mntrs)
  		goto out_free_skb;
  
  	/* room for the radiotap header based on driver features */
  	needed_headroom = ieee80211_rx_radiotap_space(local, status);
  
  	if (skb_headroom(skb) < needed_headroom &&
  	    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC))
  		goto out_free_skb;
  
  	/* prepend radiotap information */
  	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom,
  					 false);
  
  	skb_set_mac_header(skb, 0);
  	skb->ip_summed = CHECKSUM_UNNECESSARY;
  	skb->pkt_type = PACKET_OTHERHOST;
  	skb->protocol = htons(ETH_P_802_2);
  
  	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
  		if (!ieee80211_sdata_running(sdata))
  			continue;
  
  		if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
  		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
  			continue;
  
  		if (prev_dev) {
  			skb2 = skb_clone(skb, GFP_ATOMIC);
  			if (skb2) {
  				skb2->dev = prev_dev;
  				netif_receive_skb(skb2);
  			}
  		}
  
  		prev_dev = sdata->dev;
  		sdata->dev->stats.rx_packets++;
  		sdata->dev->stats.rx_bytes += skb->len;
  	}
  
  	if (prev_dev) {
  		skb->dev = prev_dev;
  		netif_receive_skb(skb);
  		return;
  	}
  
   out_free_skb:
  	dev_kfree_skb(skb);
  }
  
  static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
  					 ieee80211_rx_result res)
  {
  	switch (res) {
  	case RX_DROP_MONITOR:
  		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
  		if (rx->sta)
  			rx->sta->rx_dropped++;
  		/* fall through */
  	case RX_CONTINUE: {
  		struct ieee80211_rate *rate = NULL;
  		struct ieee80211_supported_band *sband;
  		struct ieee80211_rx_status *status;
  
  		status = IEEE80211_SKB_RXCB((rx->skb));
  
  		sband = rx->local->hw.wiphy->bands[status->band];
  		if (!(status->flag & RX_FLAG_HT) &&
  		    !(status->flag & RX_FLAG_VHT))
  			rate = &sband->bitrates[status->rate_idx];
  
  		ieee80211_rx_cooked_monitor(rx, rate);
  		break;
  		}
  	case RX_DROP_UNUSABLE:
  		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
  		if (rx->sta)
  			rx->sta->rx_dropped++;
  		dev_kfree_skb(rx->skb);
  		break;
  	case RX_QUEUED:
  		I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
  		break;
  	}
  }
  
  static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
  				  struct sk_buff_head *frames)
  {
  	ieee80211_rx_result res = RX_DROP_MONITOR;
  	struct sk_buff *skb;
  
  #define CALL_RXH(rxh)			\
  	do {				\
  		res = rxh(rx);		\
  		if (res != RX_CONTINUE)	\
  			goto rxh_next;  \
  	} while (0);
  
  	spin_lock_bh(&rx->local->rx_path_lock);
  
  	while ((skb = __skb_dequeue(frames))) {
  		/*
  		 * all the other fields are valid across frames
  		 * that belong to an aMPDU since they are on the
  		 * same TID from the same station
  		 */
  		rx->skb = skb;
  
  		CALL_RXH(ieee80211_rx_h_check_more_data)
  		CALL_RXH(ieee80211_rx_h_uapsd_and_pspoll)
  		CALL_RXH(ieee80211_rx_h_sta_process)
  		CALL_RXH(ieee80211_rx_h_decrypt)
  		CALL_RXH(ieee80211_rx_h_defragment)
  		CALL_RXH(ieee80211_rx_h_michael_mic_verify)
  		/* must be after MMIC verify so header is counted in MPDU mic */
  #ifdef CONFIG_MAC80211_MESH
  		if (ieee80211_vif_is_mesh(&rx->sdata->vif))
  			CALL_RXH(ieee80211_rx_h_mesh_fwding);
  #endif
  		CALL_RXH(ieee80211_rx_h_amsdu)
  		CALL_RXH(ieee80211_rx_h_data)
  
  		/* special treatment -- needs the queue */
  		res = ieee80211_rx_h_ctrl(rx, frames);
  		if (res != RX_CONTINUE)
  			goto rxh_next;
  
  		CALL_RXH(ieee80211_rx_h_mgmt_check)
  		CALL_RXH(ieee80211_rx_h_action)
  		CALL_RXH(ieee80211_rx_h_userspace_mgmt)
  		CALL_RXH(ieee80211_rx_h_action_return)
  		CALL_RXH(ieee80211_rx_h_mgmt)
  
   rxh_next:
  		ieee80211_rx_handlers_result(rx, res);
  
  #undef CALL_RXH
  	}
  
  	spin_unlock_bh(&rx->local->rx_path_lock);
  }
  
  static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
  {
  	struct sk_buff_head reorder_release;
  	ieee80211_rx_result res = RX_DROP_MONITOR;
  
  	__skb_queue_head_init(&reorder_release);
  
  #define CALL_RXH(rxh)			\
  	do {				\
  		res = rxh(rx);		\
  		if (res != RX_CONTINUE)	\
  			goto rxh_next;  \
  	} while (0);
  
  	CALL_RXH(ieee80211_rx_h_check)
  
  	ieee80211_rx_reorder_ampdu(rx, &reorder_release);
  
  	ieee80211_rx_handlers(rx, &reorder_release);
  	return;
  
   rxh_next:
  	ieee80211_rx_handlers_result(rx, res);
  
  #undef CALL_RXH
  }
  
  /*
   * This function makes calls into the RX path, therefore
   * it has to be invoked under RCU read lock.
   */
  void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
  {
  	struct sk_buff_head frames;
  	struct ieee80211_rx_data rx = {
  		.sta = sta,
  		.sdata = sta->sdata,
  		.local = sta->local,
  		/* This is OK -- must be QoS data frame */
  		.security_idx = tid,
  		.seqno_idx = tid,
  		.flags = 0,
  	};
  	struct tid_ampdu_rx *tid_agg_rx;
  
  	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
  	if (!tid_agg_rx)
  		return;
  
  	__skb_queue_head_init(&frames);
  
  	spin_lock(&tid_agg_rx->reorder_lock);
  	ieee80211_sta_reorder_release(sta->sdata, tid_agg_rx, &frames);
  	spin_unlock(&tid_agg_rx->reorder_lock);
  
  	ieee80211_rx_handlers(&rx, &frames);
  }
  
  /* main receive path */
  
  static bool prepare_for_handlers(struct ieee80211_rx_data *rx,
  				 struct ieee80211_hdr *hdr)
  {
  	struct ieee80211_sub_if_data *sdata = rx->sdata;
  	struct sk_buff *skb = rx->skb;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  	u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
  	int multicast = is_multicast_ether_addr(hdr->addr1);
  
  	switch (sdata->vif.type) {
  	case NL80211_IFTYPE_STATION:
  		if (!bssid && !sdata->u.mgd.use_4addr)
  			return false;
  		if (!multicast &&
  		    !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
  			if (!(sdata->dev->flags & IFF_PROMISC) ||
  			    sdata->u.mgd.use_4addr)
  				return false;
  			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
  		}
  		break;
  	case NL80211_IFTYPE_ADHOC:
  		if (!bssid)
  			return false;
  		if (ether_addr_equal(sdata->vif.addr, hdr->addr2) ||
  		    ether_addr_equal(sdata->u.ibss.bssid, hdr->addr2))
  			return false;
  		if (ieee80211_is_beacon(hdr->frame_control)) {
  			return true;
  		} else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
  			return false;
  		} else if (!multicast &&
  			   !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
  			if (!(sdata->dev->flags & IFF_PROMISC))
  				return false;
  			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
  		} else if (!rx->sta) {
  			int rate_idx;
  			if (status->flag & (RX_FLAG_HT | RX_FLAG_VHT))
  				rate_idx = 0; /* TODO: HT/VHT rates */
  			else
  				rate_idx = status->rate_idx;
  			ieee80211_ibss_rx_no_sta(sdata, bssid, hdr->addr2,
  						 BIT(rate_idx));
  		}
  		break;
  	case NL80211_IFTYPE_MESH_POINT:
  		if (!multicast &&
  		    !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
  			if (!(sdata->dev->flags & IFF_PROMISC))
  				return false;
  
  			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
  		}
  		break;
  	case NL80211_IFTYPE_AP_VLAN:
  	case NL80211_IFTYPE_AP:
  		if (!bssid) {
  			if (!ether_addr_equal(sdata->vif.addr, hdr->addr1))
  				return false;
  		} else if (!ieee80211_bssid_match(bssid, sdata->vif.addr)) {
  			/*
  			 * Accept public action frames even when the
  			 * BSSID doesn't match, this is used for P2P
  			 * and location updates. Note that mac80211
  			 * itself never looks at these frames.
  			 */
  			if (!multicast &&
  			    !ether_addr_equal(sdata->vif.addr, hdr->addr1))
  				return false;
  			if (ieee80211_is_public_action(hdr, skb->len))
  				return true;
  			if (!ieee80211_is_beacon(hdr->frame_control))
  				return false;
  			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
  		}
  		break;
  	case NL80211_IFTYPE_WDS:
  		if (bssid || !ieee80211_is_data(hdr->frame_control))
  			return false;
  		if (!ether_addr_equal(sdata->u.wds.remote_addr, hdr->addr2))
  			return false;
  		break;
  	case NL80211_IFTYPE_P2P_DEVICE:
  		if (!ieee80211_is_public_action(hdr, skb->len) &&
  		    !ieee80211_is_probe_req(hdr->frame_control) &&
  		    !ieee80211_is_probe_resp(hdr->frame_control) &&
  		    !ieee80211_is_beacon(hdr->frame_control))
  			return false;
  		if (!ether_addr_equal(sdata->vif.addr, hdr->addr1) &&
  		    !multicast)
  			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
  		break;
  	default:
  		/* should never get here */
  		WARN_ON_ONCE(1);
  		break;
  	}
  
  	return true;
  }
  
  /*
   * This function returns whether or not the SKB
   * was destined for RX processing or not, which,
   * if consume is true, is equivalent to whether
   * 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 ieee80211_local *local = rx->local;
  	struct ieee80211_sub_if_data *sdata = rx->sdata;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  	struct ieee80211_hdr *hdr = (void *)skb->data;
  
  	rx->skb = skb;
  	status->rx_flags |= IEEE80211_RX_RA_MATCH;
  
  	if (!prepare_for_handlers(rx, hdr))
  		return false;
  
  	if (!consume) {
  		skb = skb_copy(skb, GFP_ATOMIC);
  		if (!skb) {
  			if (net_ratelimit())
  				wiphy_debug(local->hw.wiphy,
  					"failed to copy skb for %s
  ",
  					sdata->name);
  			return true;
  		}
  
  		rx->skb = skb;
  	}
  
  	ieee80211_invoke_rx_handlers(rx);
  	return true;
  }
  
  /*
   * This is the actual Rx frames handler. as it blongs to Rx path it must
   * be called with rcu_read_lock protection.
   */
  static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
  					 struct sk_buff *skb)
  {
  	struct ieee80211_local *local = hw_to_local(hw);
  	struct ieee80211_sub_if_data *sdata;
  	struct ieee80211_hdr *hdr;
  	__le16 fc;
  	struct ieee80211_rx_data rx;
  	struct ieee80211_sub_if_data *prev;
  	struct sta_info *sta, *tmp, *prev_sta;
  	int err = 0;
  
  	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
  	memset(&rx, 0, sizeof(rx));
  	rx.skb = skb;
  	rx.local = local;
  
  	if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
  		local->dot11ReceivedFragmentCount++;
  
  	if (ieee80211_is_mgmt(fc)) {
  		/* drop frame if too short for header */
  		if (skb->len < ieee80211_hdrlen(fc))
  			err = -ENOBUFS;
  		else
  			err = skb_linearize(skb);
  	} else {
  		err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
  	}
  
  	if (err) {
  		dev_kfree_skb(skb);
  		return;
  	}
  
  	hdr = (struct ieee80211_hdr *)skb->data;
  	ieee80211_parse_qos(&rx);
  	ieee80211_verify_alignment(&rx);
  
  	if (unlikely(ieee80211_is_probe_resp(hdr->frame_control) ||
  		     ieee80211_is_beacon(hdr->frame_control)))
  		ieee80211_scan_rx(local, skb);
  
  	if (ieee80211_is_data(fc)) {
  		prev_sta = NULL;
  
  		for_each_sta_info(local, hdr->addr2, sta, tmp) {
  			if (!prev_sta) {
  				prev_sta = sta;
  				continue;
  			}
  
  			rx.sta = prev_sta;
  			rx.sdata = prev_sta->sdata;
  			ieee80211_prepare_and_rx_handle(&rx, skb, false);
  
  			prev_sta = sta;
  		}
  
  		if (prev_sta) {
  			rx.sta = prev_sta;
  			rx.sdata = prev_sta->sdata;
  
  			if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
  				return;
  			goto out;
  		}
  	}
  
  	prev = NULL;
  
  	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
  		if (!ieee80211_sdata_running(sdata))
  			continue;
  
  		if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
  		    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
  			continue;
  
  		/*
  		 * frame is destined for this interface, but if it's
  		 * not also for the previous one we handle that after
  		 * the loop to avoid copying the SKB once too much
  		 */
  
  		if (!prev) {
  			prev = sdata;
  			continue;
  		}
  
  		rx.sta = sta_info_get_bss(prev, hdr->addr2);
  		rx.sdata = prev;
  		ieee80211_prepare_and_rx_handle(&rx, skb, false);
  
  		prev = sdata;
  	}
  
  	if (prev) {
  		rx.sta = sta_info_get_bss(prev, hdr->addr2);
  		rx.sdata = prev;
  
  		if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
  			return;
  	}
  
   out:
  	dev_kfree_skb(skb);
  }
  
  /*
   * This is the receive path handler. It is called by a low level driver when an
   * 802.11 MPDU is received from the hardware.
   */
  void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
  {
  	struct ieee80211_local *local = hw_to_local(hw);
  	struct ieee80211_rate *rate = NULL;
  	struct ieee80211_supported_band *sband;
  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  
  	WARN_ON_ONCE(softirq_count() == 0);
  
  	if (WARN_ON(status->band >= IEEE80211_NUM_BANDS))
  		goto drop;
  
  	sband = local->hw.wiphy->bands[status->band];
  	if (WARN_ON(!sband))
  		goto drop;
  
  	/*
  	 * If we're suspending, it is possible although not too likely
  	 * that we'd be receiving frames after having already partially
  	 * quiesced the stack. We can't process such frames then since
  	 * that might, for example, cause stations to be added or other
  	 * driver callbacks be invoked.
  	 */
  	if (unlikely(local->quiescing || local->suspended))
  		goto drop;
  
  	/* We might be during a HW reconfig, prevent Rx for the same reason */
  	if (unlikely(local->in_reconfig))
  		goto drop;
  
  	/*
  	 * The same happens when we're not even started,
  	 * but that's worth a warning.
  	 */
  	if (WARN_ON(!local->started))
  		goto drop;
  
  	if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
  		/*
  		 * Validate the rate, unless a PLCP error means that
  		 * we probably can't have a valid rate here anyway.
  		 */
  
  		if (status->flag & RX_FLAG_HT) {
  			/*
  			 * rate_idx is MCS index, which can be [0-76]
  			 * as documented on:
  			 *
  			 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
  			 *
  			 * Anything else would be some sort of driver or
  			 * hardware error. The driver should catch hardware
  			 * errors.
  			 */
  			if (WARN(status->rate_idx > 76,
  				 "Rate marked as an HT rate but passed "
  				 "status->rate_idx is not "
  				 "an MCS index [0-76]: %d (0x%02x)
  ",
  				 status->rate_idx,
  				 status->rate_idx))
  				goto drop;
  		} else if (status->flag & RX_FLAG_VHT) {
  			if (WARN_ONCE(status->rate_idx > 9 ||
  				      !status->vht_nss ||
  				      status->vht_nss > 8,
  				      "Rate marked as a VHT rate but data is invalid: MCS: %d, NSS: %d
  ",
  				      status->rate_idx, status->vht_nss))
  				goto drop;
  		} else {
  			if (WARN_ON(status->rate_idx >= sband->n_bitrates))
  				goto drop;
  			rate = &sband->bitrates[status->rate_idx];
  		}
  	}
  
  	status->rx_flags = 0;
  
  	/*
  	 * key references and virtual interfaces are protected using RCU
  	 * and this requires that we are in a read-side RCU section during
  	 * receive processing
  	 */
  	rcu_read_lock();
  
  	/*
  	 * Frames with failed FCS/PLCP checksum are not returned,
  	 * all other frames are returned without radiotap header
  	 * if it was previously present.
  	 * Also, frames with less than 16 bytes are dropped.
  	 */
  	skb = ieee80211_rx_monitor(local, skb, rate);
  	if (!skb) {
  		rcu_read_unlock();
  		return;
  	}
  
  	ieee80211_tpt_led_trig_rx(local,
  			((struct ieee80211_hdr *)skb->data)->frame_control,
  			skb->len);
  	__ieee80211_rx_handle_packet(hw, skb);
  
  	rcu_read_unlock();
  
  	return;
   drop:
  	kfree_skb(skb);
  }
  EXPORT_SYMBOL(ieee80211_rx);
  
  /* This is a version of the rx handler that can be called from hard irq
   * context. Post the skb on the queue and schedule the tasklet */
  void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
  {
  	struct ieee80211_local *local = hw_to_local(hw);
  
  	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
  
  	skb->pkt_type = IEEE80211_RX_MSG;
  	skb_queue_tail(&local->skb_queue, skb);
  	tasklet_schedule(&local->tasklet);
  }
  EXPORT_SYMBOL(ieee80211_rx_irqsafe);