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From: Johannes Berg <johannes@sipsolutions.net>
To: Julia Lawall <julia.lawall@lip6.fr>
Cc: backports@vger.kernel.org
Subject: spatch missing a transformation
Date: Tue, 05 May 2015 15:13:39 +0200	[thread overview]
Message-ID: <1430831619.1950.16.camel@sipsolutions.net> (raw)

[-- Attachment #1: Type: text/plain, Size: 513 bytes --]

Hi Julia,

With the attached file that I'm working on, against mac80211's tx.c and
rx.c (also attached), I'm getting some very strange spatch behaviour.

If I run
	spatch --sp-file test.cocci rx.c tx.c
it will happily modify both files.

If I run it on just rx.c, it will modify the code there. If I run it
only on tx.c, it will not modify it. If I run it on a whole directory,
it only modifies rx.c as well.

Unfortunately I'm still on rc24 right now, I'll try to update and see if
the issue persists.

johannes

[-- Attachment #2: rx.c --]
[-- Type: text/x-csrc, Size: 103420 bytes --]

/*
 * 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>
 * Copyright 2013-2014  Intel Mobile Communications GmbH
 *
 * 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"

static inline void ieee80211_rx_stats(struct net_device *dev, u32 len)
{
	struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats);

	u64_stats_update_begin(&tstats->syncp);
	tstats->rx_packets++;
	tstats->rx_bytes += len;
	u64_stats_update_end(&tstats->syncp);
}

/*
 * 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,
					   unsigned int rtap_vendor_space)
{
	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;
		}
	}

	__pskb_pull(skb, rtap_vendor_space);

	return skb;
}

static inline bool should_drop_frame(struct sk_buff *skb, int present_fcs_len,
				     unsigned int rtap_vendor_space)
{
	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
	struct ieee80211_hdr *hdr;

	hdr = (void *)(skb->data + rtap_vendor_space);

	if (status->flag & (RX_FLAG_FAILED_FCS_CRC |
			    RX_FLAG_FAILED_PLCP_CRC |
			    RX_FLAG_AMPDU_IS_ZEROLEN))
		return true;

	if (unlikely(skb->len < 16 + present_fcs_len + rtap_vendor_space))
		return true;

	if (ieee80211_is_ctl(hdr->frame_control) &&
	    !ieee80211_is_pspoll(hdr->frame_control) &&
	    !ieee80211_is_back_req(hdr->frame_control))
		return true;

	return false;
}

static int
ieee80211_rx_radiotap_hdrlen(struct ieee80211_local *local,
			     struct ieee80211_rx_status *status,
			     struct sk_buff *skb)
{
	int len;

	/* always present fields */
	len = sizeof(struct ieee80211_radiotap_header) + 8;

	/* allocate extra bitmaps */
	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->flag & RX_FLAG_RADIOTAP_VENDOR_DATA) {
		struct ieee80211_vendor_radiotap *rtap = (void *)skb->data;

		/* vendor presence bitmap */
		len += 4;
		/* alignment for fixed 6-byte vendor data header */
		len = ALIGN(len, 2);
		/* vendor data header */
		len += 6;
		if (WARN_ON(rtap->align == 0))
			rtap->align = 1;
		len = ALIGN(len, rtap->align);
		len += rtap->len + rtap->pad;
	}

	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;
	struct ieee80211_vendor_radiotap rtap = {};

	if (status->flag & RX_FLAG_RADIOTAP_VENDOR_DATA) {
		rtap = *(struct ieee80211_vendor_radiotap *)skb->data;
		/* rtap.len and rtap.pad are undone immediately */
		skb_pull(skb, sizeof(rtap) + rtap.len + rtap.pad);
	}

	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 - rtap.len - rtap.pad);
	it_present = &rthdr->it_present;

	/* radiotap header, set always present flags */
	rthdr->it_len = cpu_to_le16(rtap_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->flag & RX_FLAG_RADIOTAP_VENDOR_DATA) {
		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 = rtap.present;
	}

	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_CCK | 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;
		if (status->flag & RX_FLAG_LDPC)
			*pos |= IEEE80211_RADIOTAP_MCS_FEC_LDPC;
		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);
		put_unaligned_le16(known, pos);
		pos += 2;
		/* flags */
		if (status->flag & RX_FLAG_SHORT_GI)
			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
		/* in VHT, STBC is binary */
		if (status->flag & RX_FLAG_STBC_MASK)
			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_STBC;
		if (status->vht_flag & RX_VHT_FLAG_BF)
			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_BEAMFORMED;
		pos++;
		/* bandwidth */
		if (status->vht_flag & RX_VHT_FLAG_80MHZ)
			*pos++ = 4;
		else if (status->vht_flag & RX_VHT_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 */
		if (status->flag & RX_FLAG_LDPC)
			*pos |= IEEE80211_RADIOTAP_CODING_LDPC_USER0;
		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->flag & RX_FLAG_RADIOTAP_VENDOR_DATA) {
		/* ensure 2 byte alignment for the vendor field as required */
		if ((pos - (u8 *)rthdr) & 1)
			*pos++ = 0;
		*pos++ = rtap.oui[0];
		*pos++ = rtap.oui[1];
		*pos++ = rtap.oui[2];
		*pos++ = rtap.subns;
		put_unaligned_le16(rtap.len, pos);
		pos += 2;
		/* align the actual payload as requested */
		while ((pos - (u8 *)rthdr) & (rtap.align - 1))
			*pos++ = 0;
		/* data (and possible padding) already follows */
	}
}

/*
 * 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 rt_hdrlen, needed_headroom;
	struct sk_buff *skb, *skb2;
	struct net_device *prev_dev = NULL;
	int present_fcs_len = 0;
	unsigned int rtap_vendor_space = 0;

	if (unlikely(status->flag & RX_FLAG_RADIOTAP_VENDOR_DATA)) {
		struct ieee80211_vendor_radiotap *rtap = (void *)origskb->data;

		rtap_vendor_space = sizeof(*rtap) + rtap->len + rtap->pad;
	}

	/*
	 * 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 + rtap_vendor_space)) {
		dev_kfree_skb(origskb);
		return NULL;
	}

	if (!local->monitors) {
		if (should_drop_frame(origskb, present_fcs_len,
				      rtap_vendor_space)) {
			dev_kfree_skb(origskb);
			return NULL;
		}

		return remove_monitor_info(local, origskb, rtap_vendor_space);
	}

	/* room for the radiotap header based on driver features */
	rt_hdrlen = ieee80211_rx_radiotap_hdrlen(local, status, origskb);
	needed_headroom = rt_hdrlen - rtap_vendor_space;

	if (should_drop_frame(origskb, present_fcs_len, rtap_vendor_space)) {
		/* 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,
					      rtap_vendor_space);

		if (!skb)
			return origskb;
	}

	/* prepend radiotap information */
	ieee80211_add_rx_radiotap_header(local, skb, rate, rt_hdrlen, 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;
		ieee80211_rx_stats(sdata->dev, 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 CPTCFG_MAC80211_VERBOSE_DEBUG
	WARN_ONCE((unsigned long)rx->skb->data & 1,
		  "unaligned packet at 0x%p\n", 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 (is_multicast_ether_addr(hdr->addr1))
		return 0;

	return ieee80211_is_robust_mgmt_frame(skb);
}


static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;

	if (!is_multicast_ether_addr(hdr->addr1))
		return 0;

	return ieee80211_is_robust_mgmt_frame(skb);
}


/* 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;
	struct ieee80211_mmie_16 *mmie16;

	if (skb->len < 24 + sizeof(*mmie) || !is_multicast_ether_addr(hdr->da))
		return -1;

	if (!ieee80211_is_robust_mgmt_frame(skb))
		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 le16_to_cpu(mmie->key_id);

	mmie16 = (struct ieee80211_mmie_16 *)
		(skb->data + skb->len - sizeof(*mmie16));
	if (skb->len >= 24 + sizeof(*mmie16) &&
	    mmie16->element_id == WLAN_EID_MMIE &&
	    mmie16->length == sizeof(*mmie16) - 2)
		return le16_to_cpu(mmie16->key_id);

	return -1;
}

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_head *skb_list = &tid_agg_rx->reorder_buf[index];
	struct sk_buff *skb;
	struct ieee80211_rx_status *status;

	lockdep_assert_held(&tid_agg_rx->reorder_lock);

	if (skb_queue_empty(skb_list))
		goto no_frame;

	if (!ieee80211_rx_reorder_ready(skb_list)) {
		__skb_queue_purge(skb_list);
		goto no_frame;
	}

	/* release frames from the reorder ring buffer */
	tid_agg_rx->stored_mpdu_num--;
	while ((skb = __skb_dequeue(skb_list))) {
		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, i, 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 (!ieee80211_rx_reorder_ready(&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 (!ieee80211_rx_reorder_ready(
					&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;

			/* don't leave incomplete A-MSDUs around */
			for (i = (index + 1) % tid_agg_rx->buf_size; i != j;
			     i = (i + 1) % tid_agg_rx->buf_size)
				__skb_queue_purge(&tid_agg_rx->reorder_buf[i]);

			ht_dbg_ratelimited(sdata,
					   "release an RX reorder frame due to timeout on earlier frames\n");
			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 (ieee80211_rx_reorder_ready(
				&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 (ieee80211_rx_reorder_ready(
					&tid_agg_rx->reorder_buf[j]))
				break;
		}

 set_release_timer:

		if (!tid_agg_rx->removed)
			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;
	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
	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);

	/*
	 * Offloaded BA sessions have no known starting sequence number so pick
	 * one from first Rxed frame for this tid after BA was started.
	 */
	if (unlikely(tid_agg_rx->auto_seq)) {
		tid_agg_rx->auto_seq = false;
		tid_agg_rx->ssn = mpdu_seq_num;
		tid_agg_rx->head_seq_num = mpdu_seq_num;
	}

	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 (ieee80211_rx_reorder_ready(&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) {
		if (!(status->flag & RX_FLAG_AMSDU_MORE))
			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 */
	__skb_queue_tail(&tid_agg_rx->reorder_buf[index], skb);
	if (!(status->flag & RX_FLAG_AMSDU_MORE)) {
		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 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;

	/* 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_dup(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)
		return RX_CONTINUE;

	if (ieee80211_is_ctl(hdr->frame_control) ||
	    ieee80211_is_qos_nullfunc(hdr->frame_control) ||
	    is_multicast_ether_addr(hdr->addr1))
		return RX_CONTINUE;

	if (rx->sta) {
		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
			     rx->sta->last_seq_ctrl[rx->seqno_idx] ==
			     hdr->seq_ctrl)) {
			I802_DEBUG_INC(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;
		}
	}

	return RX_CONTINUE;
}

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;

	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->sdata->vif.type != NL80211_IFTYPE_OCB &&
		     (!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;
	int tid;

	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\n",
	       sta->sta.addr, sta->sta.aid);

	ieee80211_clear_fast_xmit(sta);

	if (!sta->sta.txq[0])
		return;

	for (tid = 0; tid < ARRAY_SIZE(sta->sta.txq); tid++) {
		struct txq_info *txqi = to_txq_info(sta->sta.txq[tid]);

		if (!skb_queue_len(&txqi->queue))
			set_bit(tid, &sta->txq_buffered_tids);
		else
			clear_bit(tid, &sta->txq_buffered_tids);
	}
}

static void sta_ps_end(struct sta_info *sta)
{
	ps_dbg(sta->sdata, "STA %pM aid %d exits power save mode\n",
	       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\n",
		       sta->sta.addr, sta->sta.aid);
		return;
	}

	set_sta_flag(sta, WLAN_STA_PS_DELIVER);
	clear_sta_flag(sta, WLAN_STA_PS_STA);
	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)
		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) &&
			    !is_multicast_ether_addr(hdr->addr1)) {
				sta->last_rx_rate_idx = status->rate_idx;
				sta->last_rx_rate_flag = status->flag;
				sta->last_rx_rate_vht_flag = status->vht_flag;
				sta->last_rx_rate_vht_nss = status->vht_nss;
			}
		}
	} else if (rx->sdata->vif.type == NL80211_IFTYPE_OCB) {
		sta->last_rx = jiffies;
	} 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_flag = status->vht_flag;
			sta->last_rx_rate_vht_nss = status->vht_nss;
		}
	}

	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) &&
	    /* PM bit is only checked in frames where it isn't reserved,
	     * in AP mode it's reserved in non-bufferable management frames
	     * (cf. IEEE 802.11-2012 8.2.4.1.7 Power Management field)
	     */
	    (!ieee80211_is_mgmt(hdr->frame_control) ||
	     ieee80211_is_bufferable_mmpdu(hdr->frame_control))) {
		if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
			if (!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.
	 */

	/* 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, IEEE80211_CCMP_MIC_LEN);
		break;
	case WLAN_CIPHER_SUITE_CCMP_256:
		result = ieee80211_crypto_ccmp_decrypt(
			rx, IEEE80211_CCMP_256_MIC_LEN);
		break;
	case WLAN_CIPHER_SUITE_AES_CMAC:
		result = ieee80211_crypto_aes_cmac_decrypt(rx);
		break;
	case WLAN_CIPHER_SUITE_BIP_CMAC_256:
		result = ieee80211_crypto_aes_cmac_256_decrypt(rx);
		break;
	case WLAN_CIPHER_SUITE_BIP_GMAC_128:
	case WLAN_CIPHER_SUITE_BIP_GMAC_256:
		result = ieee80211_crypto_aes_gmac_decrypt(rx);
		break;
	case WLAN_CIPHER_SUITE_GCMP:
	case WLAN_CIPHER_SUITE_GCMP_256:
		result = ieee80211_crypto_gcmp_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)) {
		I802_DEBUG_INC(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 ||
		     rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP_256) &&
		    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 &&
		     rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP_256))
			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_head_defrag);
		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))
		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(rx->skb)))
			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;

	skb = rx->skb;
	xmit_skb = NULL;

	ieee80211_rx_stats(dev, skb->len);

	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
	    (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\n",
						    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));
		if (rx->local->napi)
			napi_gro_receive(rx->local->napi, skb);
		else
			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;
		}

		ieee80211_deliver_skb(rx);
	}

	return RX_QUEUED;
}

#ifdef CPTCFG_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_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);

	if (ieee80211_drop_unencrypted(rx, hdr->frame_control))
		return RX_DROP_MONITOR;

	/* 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))
		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\n",
				    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))
		return RX_CONTINUE;
	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;

	if (rx->sta) {
		/* The seqno index has the same property as needed
		 * for the rx_msdu field, i.e. it is IEEE80211_NUM_TIDS
		 * for non-QoS-data frames. Here we know it's a data
		 * frame, so count MSDUs.
		 */
		rx->sta->rx_msdu[rx->seqno_idx]++;
	}

	/*
	 * 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;

	/* directly handle TDLS channel switch requests/responses */
	if (unlikely(((struct ethhdr *)rx->skb->data)->h_proto ==
						cpu_to_be16(ETH_P_TDLS))) {
		struct ieee80211_tdls_data *tf = (void *)rx->skb->data;

		if (pskb_may_pull(rx->skb,
				  offsetof(struct ieee80211_tdls_data, u)) &&
		    tf->payload_type == WLAN_TDLS_SNAP_RFTYPE &&
		    tf->category == WLAN_CATEGORY_TDLS &&
		    (tf->action_code == WLAN_TDLS_CHANNEL_SWITCH_REQUEST ||
		     tf->action_code == WLAN_TDLS_CHANNEL_SWITCH_RESPONSE)) {
			rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TDLS_CHSW;
			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;
		}
	}

	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;

	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;
		struct ieee80211_event event = {
			.type = BAR_RX_EVENT,
		};

		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;
		event.u.ba.tid = tid;
		event.u.ba.ssn = start_seq_num;
		event.u.ba.sta = &rx->sta->sta;

		/* 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);

		drv_event_callback(rx->local, rx->sdata, &event);

		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 (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;

	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 max_bw, 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)
				max_bw = IEEE80211_STA_RX_BW_20;
			else
				max_bw = ieee80211_sta_cap_rx_bw(rx->sta);

			/* set cur_max_bandwidth and recalc sta bw */
			rx->sta->cur_max_bandwidth = max_bw;
			new_bw = ieee80211_sta_cur_vht_bw(rx->sta);

			if (rx->sta->sta.bandwidth == new_bw)
				goto handled;

			rx->sta->sta.bandwidth = new_bw;
			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)) {
		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_OCB &&
	    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;

	/* vendor data is long removed here */
	status->flag &= ~RX_FLAG_RADIOTAP_VENDOR_DATA;
	/* room for the radiotap header based on driver features */
	needed_headroom = ieee80211_rx_radiotap_hdrlen(local, status, skb);

	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;
		ieee80211_rx_stats(sdata->dev, 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);

	/* Lock here to avoid hitting all of the data used in the RX
	 * path (e.g. key data, station data, ...) concurrently when
	 * a frame is released from the reorder buffer due to timeout
	 * from the timer, potentially concurrently with RX from the
	 * driver.
	 */
	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 CPTCFG_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_dup)
	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);

	if (!skb_queue_empty(&frames)) {
		struct ieee80211_event event = {
			.type = BA_FRAME_TIMEOUT,
			.u.ba.tid = tid,
			.u.ba.sta = &sta->sta,
		};
		drv_event_callback(rx.local, rx.sdata, &event);
	}

	ieee80211_rx_handlers(&rx, &frames);
}

/* main receive path */

static bool ieee80211_accept_frame(struct ieee80211_rx_data *rx)
{
	struct ieee80211_sub_if_data *sdata = rx->sdata;
	struct sk_buff *skb = rx->skb;
	struct ieee80211_hdr *hdr = (void *)skb->data;
	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)
			return true;
		return ether_addr_equal(sdata->vif.addr, hdr->addr1);
	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;
		if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid))
			return false;
		if (!multicast &&
		    !ether_addr_equal(sdata->vif.addr, hdr->addr1))
			return false;
		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));
		}
		return true;
	case NL80211_IFTYPE_OCB:
		if (!bssid)
			return false;
		if (ieee80211_is_beacon(hdr->frame_control))
			return false;
		if (!is_broadcast_ether_addr(bssid))
			return false;
		if (!multicast &&
		    !ether_addr_equal(sdata->dev->dev_addr, hdr->addr1))
			return false;
		if (!rx->sta) {
			int rate_idx;
			if (status->flag & RX_FLAG_HT)
				rate_idx = 0; /* TODO: HT rates */
			else
				rate_idx = status->rate_idx;
			ieee80211_ocb_rx_no_sta(sdata, bssid, hdr->addr2,
						BIT(rate_idx));
		}
		return true;
	case NL80211_IFTYPE_MESH_POINT:
		if (multicast)
			return true;
		return ether_addr_equal(sdata->vif.addr, hdr->addr1);
	case NL80211_IFTYPE_AP_VLAN:
	case NL80211_IFTYPE_AP:
		if (!bssid)
			return ether_addr_equal(sdata->vif.addr, hdr->addr1);

		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;
			return ieee80211_is_beacon(hdr->frame_control);
		}

		if (!ieee80211_has_tods(hdr->frame_control)) {
			/* ignore data frames to TDLS-peers */
			if (ieee80211_is_data(hdr->frame_control))
				return false;
			/* ignore action frames to TDLS-peers */
			if (ieee80211_is_action(hdr->frame_control) &&
			    !ether_addr_equal(bssid, hdr->addr1))
				return false;
		}
		return true;
	case NL80211_IFTYPE_WDS:
		if (bssid || !ieee80211_is_data(hdr->frame_control))
			return false;
		return ether_addr_equal(sdata->u.wds.remote_addr, hdr->addr2);
	case NL80211_IFTYPE_P2P_DEVICE:
		return 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);
	default:
		break;
	}

	WARN_ON_ONCE(1);
	return false;
}

/*
 * 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;

	rx->skb = skb;

	if (!ieee80211_accept_frame(rx))
		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\n",
					sdata->name);
			return true;
		}

		rx->skb = skb;
	}

	ieee80211_invoke_rx_handlers(rx);
	return true;
}

/*
 * This is the actual Rx frames handler. as it belongs 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, *prev_sta;
	struct rhash_head *tmp;
	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))
		I802_DEBUG_INC(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)) {
		const struct bucket_table *tbl;

		prev_sta = NULL;

		tbl = rht_dereference_rcu(local->sta_hash.tbl, &local->sta_hash);

		for_each_sta_info(local, tbl, 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)\n",
				 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\n",
				      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);

[-- Attachment #3: test.cocci --]
[-- Type: text/plain, Size: 106 bytes --]

@nd@
identifier dev;
@@
struct net_device *dev;
@@
identifier nd.dev;
@@
-dev->tstats
+netdev_tstats(dev)

[-- Attachment #4: tx.c --]
[-- Type: text/x-csrc, Size: 108014 bytes --]

/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
 * Copyright 2013-2014  Intel Mobile Communications GmbH
 *
 * 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.
 *
 *
 * Transmit and frame generation functions.
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/bitmap.h>
#include <linux/rcupdate.h>
#include <linux/export.h>
#include <net/net_namespace.h>
#include <net/ieee80211_radiotap.h>
#include <net/cfg80211.h>
#include <net/mac80211.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 "wme.h"
#include "rate.h"

/* misc utils */

static inline void ieee80211_tx_stats(struct net_device *dev, u32 len)
{
	struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats);

	u64_stats_update_begin(&tstats->syncp);
	tstats->tx_packets++;
	tstats->tx_bytes += len;
	u64_stats_update_end(&tstats->syncp);
}

static __le16 ieee80211_duration(struct ieee80211_tx_data *tx,
				 struct sk_buff *skb, int group_addr,
				 int next_frag_len)
{
	int rate, mrate, erp, dur, i, shift = 0;
	struct ieee80211_rate *txrate;
	struct ieee80211_local *local = tx->local;
	struct ieee80211_supported_band *sband;
	struct ieee80211_hdr *hdr;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ieee80211_chanctx_conf *chanctx_conf;
	u32 rate_flags = 0;

	rcu_read_lock();
	chanctx_conf = rcu_dereference(tx->sdata->vif.chanctx_conf);
	if (chanctx_conf) {
		shift = ieee80211_chandef_get_shift(&chanctx_conf->def);
		rate_flags = ieee80211_chandef_rate_flags(&chanctx_conf->def);
	}
	rcu_read_unlock();

	/* assume HW handles this */
	if (tx->rate.flags & (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))
		return 0;

	/* uh huh? */
	if (WARN_ON_ONCE(tx->rate.idx < 0))
		return 0;

	sband = local->hw.wiphy->bands[info->band];
	txrate = &sband->bitrates[tx->rate.idx];

	erp = txrate->flags & IEEE80211_RATE_ERP_G;

	/*
	 * data and mgmt (except PS Poll):
	 * - during CFP: 32768
	 * - during contention period:
	 *   if addr1 is group address: 0
	 *   if more fragments = 0 and addr1 is individual address: time to
	 *      transmit one ACK plus SIFS
	 *   if more fragments = 1 and addr1 is individual address: time to
	 *      transmit next fragment plus 2 x ACK plus 3 x SIFS
	 *
	 * IEEE 802.11, 9.6:
	 * - control response frame (CTS or ACK) shall be transmitted using the
	 *   same rate as the immediately previous frame in the frame exchange
	 *   sequence, if this rate belongs to the PHY mandatory rates, or else
	 *   at the highest possible rate belonging to the PHY rates in the
	 *   BSSBasicRateSet
	 */
	hdr = (struct ieee80211_hdr *)skb->data;
	if (ieee80211_is_ctl(hdr->frame_control)) {
		/* TODO: These control frames are not currently sent by
		 * mac80211, but should they be implemented, this function
		 * needs to be updated to support duration field calculation.
		 *
		 * RTS: time needed to transmit pending data/mgmt frame plus
		 *    one CTS frame plus one ACK frame plus 3 x SIFS
		 * CTS: duration of immediately previous RTS minus time
		 *    required to transmit CTS and its SIFS
		 * ACK: 0 if immediately previous directed data/mgmt had
		 *    more=0, with more=1 duration in ACK frame is duration
		 *    from previous frame minus time needed to transmit ACK
		 *    and its SIFS
		 * PS Poll: BIT(15) | BIT(14) | aid
		 */
		return 0;
	}

	/* data/mgmt */
	if (0 /* FIX: data/mgmt during CFP */)
		return cpu_to_le16(32768);

	if (group_addr) /* Group address as the destination - no ACK */
		return 0;

	/* Individual destination address:
	 * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
	 * CTS and ACK frames shall be transmitted using the highest rate in
	 * basic rate set that is less than or equal to the rate of the
	 * immediately previous frame and that is using the same modulation
	 * (CCK or OFDM). If no basic rate set matches with these requirements,
	 * the highest mandatory rate of the PHY that is less than or equal to
	 * the rate of the previous frame is used.
	 * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
	 */
	rate = -1;
	/* use lowest available if everything fails */
	mrate = sband->bitrates[0].bitrate;
	for (i = 0; i < sband->n_bitrates; i++) {
		struct ieee80211_rate *r = &sband->bitrates[i];

		if (r->bitrate > txrate->bitrate)
			break;

		if ((rate_flags & r->flags) != rate_flags)
			continue;

		if (tx->sdata->vif.bss_conf.basic_rates & BIT(i))
			rate = DIV_ROUND_UP(r->bitrate, 1 << shift);

		switch (sband->band) {
		case IEEE80211_BAND_2GHZ: {
			u32 flag;
			if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
				flag = IEEE80211_RATE_MANDATORY_G;
			else
				flag = IEEE80211_RATE_MANDATORY_B;
			if (r->flags & flag)
				mrate = r->bitrate;
			break;
		}
		case IEEE80211_BAND_5GHZ:
			if (r->flags & IEEE80211_RATE_MANDATORY_A)
				mrate = r->bitrate;
			break;
		case IEEE80211_BAND_60GHZ:
			/* TODO, for now fall through */
		case IEEE80211_NUM_BANDS:
			WARN_ON(1);
			break;
		}
	}
	if (rate == -1) {
		/* No matching basic rate found; use highest suitable mandatory
		 * PHY rate */
		rate = DIV_ROUND_UP(mrate, 1 << shift);
	}

	/* Don't calculate ACKs for QoS Frames with NoAck Policy set */
	if (ieee80211_is_data_qos(hdr->frame_control) &&
	    *(ieee80211_get_qos_ctl(hdr)) & IEEE80211_QOS_CTL_ACK_POLICY_NOACK)
		dur = 0;
	else
		/* Time needed to transmit ACK
		 * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
		 * to closest integer */
		dur = ieee80211_frame_duration(sband->band, 10, rate, erp,
				tx->sdata->vif.bss_conf.use_short_preamble,
				shift);

	if (next_frag_len) {
		/* Frame is fragmented: duration increases with time needed to
		 * transmit next fragment plus ACK and 2 x SIFS. */
		dur *= 2; /* ACK + SIFS */
		/* next fragment */
		dur += ieee80211_frame_duration(sband->band, next_frag_len,
				txrate->bitrate, erp,
				tx->sdata->vif.bss_conf.use_short_preamble,
				shift);
	}

	return cpu_to_le16(dur);
}

/* tx handlers */
static ieee80211_tx_result debug_noinline
ieee80211_tx_h_dynamic_ps(struct ieee80211_tx_data *tx)
{
	struct ieee80211_local *local = tx->local;
	struct ieee80211_if_managed *ifmgd;

	/* driver doesn't support power save */
	if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_PS))
		return TX_CONTINUE;

	/* hardware does dynamic power save */
	if (local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)
		return TX_CONTINUE;

	/* dynamic power save disabled */
	if (local->hw.conf.dynamic_ps_timeout <= 0)
		return TX_CONTINUE;

	/* we are scanning, don't enable power save */
	if (local->scanning)
		return TX_CONTINUE;

	if (!local->ps_sdata)
		return TX_CONTINUE;

	/* No point if we're going to suspend */
	if (local->quiescing)
		return TX_CONTINUE;

	/* dynamic ps is supported only in managed mode */
	if (tx->sdata->vif.type != NL80211_IFTYPE_STATION)
		return TX_CONTINUE;

	ifmgd = &tx->sdata->u.mgd;

	/*
	 * Don't wakeup from power save if u-apsd is enabled, voip ac has
	 * u-apsd enabled and the frame is in voip class. This effectively
	 * means that even if all access categories have u-apsd enabled, in
	 * practise u-apsd is only used with the voip ac. This is a
	 * workaround for the case when received voip class packets do not
	 * have correct qos tag for some reason, due the network or the
	 * peer application.
	 *
	 * Note: ifmgd->uapsd_queues access is racy here. If the value is
	 * changed via debugfs, user needs to reassociate manually to have
	 * everything in sync.
	 */
	if ((ifmgd->flags & IEEE80211_STA_UAPSD_ENABLED) &&
	    (ifmgd->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VO) &&
	    skb_get_queue_mapping(tx->skb) == IEEE80211_AC_VO)
		return TX_CONTINUE;

	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
		ieee80211_stop_queues_by_reason(&local->hw,
						IEEE80211_MAX_QUEUE_MAP,
						IEEE80211_QUEUE_STOP_REASON_PS,
						false);
		ifmgd->flags &= ~IEEE80211_STA_NULLFUNC_ACKED;
		ieee80211_queue_work(&local->hw,
				     &local->dynamic_ps_disable_work);
	}

	/* Don't restart the timer if we're not disassociated */
	if (!ifmgd->associated)
		return TX_CONTINUE;

	mod_timer(&local->dynamic_ps_timer, jiffies +
		  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));

	return TX_CONTINUE;
}

static ieee80211_tx_result debug_noinline
ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
{

	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
	bool assoc = false;

	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
		return TX_CONTINUE;

	if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) &&
	    test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) &&
	    !ieee80211_is_probe_req(hdr->frame_control) &&
	    !ieee80211_is_nullfunc(hdr->frame_control))
		/*
		 * When software scanning only nullfunc frames (to notify
		 * the sleep state to the AP) and probe requests (for the
		 * active scan) are allowed, all other frames should not be
		 * sent and we should not get here, but if we do
		 * nonetheless, drop them to avoid sending them
		 * off-channel. See the link below and
		 * ieee80211_start_scan() for more.
		 *
		 * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089
		 */
		return TX_DROP;

	if (tx->sdata->vif.type == NL80211_IFTYPE_OCB)
		return TX_CONTINUE;

	if (tx->sdata->vif.type == NL80211_IFTYPE_WDS)
		return TX_CONTINUE;

	if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
		return TX_CONTINUE;

	if (tx->flags & IEEE80211_TX_PS_BUFFERED)
		return TX_CONTINUE;

	if (tx->sta)
		assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);

	if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
		if (unlikely(!assoc &&
			     ieee80211_is_data(hdr->frame_control))) {
#ifdef CPTCFG_MAC80211_VERBOSE_DEBUG
			sdata_info(tx->sdata,
				   "dropped data frame to not associated station %pM\n",
				   hdr->addr1);
#endif
			I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
			return TX_DROP;
		}
	} else if (unlikely(tx->sdata->vif.type == NL80211_IFTYPE_AP &&
			    ieee80211_is_data(hdr->frame_control) &&
			    !atomic_read(&tx->sdata->u.ap.num_mcast_sta))) {
		/*
		 * No associated STAs - no need to send multicast
		 * frames.
		 */
		return TX_DROP;
	}

	return TX_CONTINUE;
}

/* This function is called whenever the AP is about to exceed the maximum limit
 * of buffered frames for power saving STAs. This situation should not really
 * happen often during normal operation, so dropping the oldest buffered packet
 * from each queue should be OK to make some room for new frames. */
static void purge_old_ps_buffers(struct ieee80211_local *local)
{
	int total = 0, purged = 0;
	struct sk_buff *skb;
	struct ieee80211_sub_if_data *sdata;
	struct sta_info *sta;

	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
		struct ps_data *ps;

		if (sdata->vif.type == NL80211_IFTYPE_AP)
			ps = &sdata->u.ap.ps;
		else if (ieee80211_vif_is_mesh(&sdata->vif))
			ps = &sdata->u.mesh.ps;
		else
			continue;

		skb = skb_dequeue(&ps->bc_buf);
		if (skb) {
			purged++;
			dev_kfree_skb(skb);
		}
		total += skb_queue_len(&ps->bc_buf);
	}

	/*
	 * Drop one frame from each station from the lowest-priority
	 * AC that has frames at all.
	 */
	list_for_each_entry_rcu(sta, &local->sta_list, list) {
		int ac;

		for (ac = IEEE80211_AC_BK; ac >= IEEE80211_AC_VO; ac--) {
			skb = skb_dequeue(&sta->ps_tx_buf[ac]);
			total += skb_queue_len(&sta->ps_tx_buf[ac]);
			if (skb) {
				purged++;
				ieee80211_free_txskb(&local->hw, skb);
				break;
			}
		}
	}

	local->total_ps_buffered = total;
	ps_dbg_hw(&local->hw, "PS buffers full - purged %d frames\n", purged);
}

static ieee80211_tx_result
ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
	struct ps_data *ps;

	/*
	 * broadcast/multicast frame
	 *
	 * If any of the associated/peer stations is in power save mode,
	 * the frame is buffered to be sent after DTIM beacon frame.
	 * This is done either by the hardware or us.
	 */

	/* powersaving STAs currently only in AP/VLAN/mesh mode */
	if (tx->sdata->vif.type == NL80211_IFTYPE_AP ||
	    tx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
		if (!tx->sdata->bss)
			return TX_CONTINUE;

		ps = &tx->sdata->bss->ps;
	} else if (ieee80211_vif_is_mesh(&tx->sdata->vif)) {
		ps = &tx->sdata->u.mesh.ps;
	} else {
		return TX_CONTINUE;
	}


	/* no buffering for ordered frames */
	if (ieee80211_has_order(hdr->frame_control))
		return TX_CONTINUE;

	if (ieee80211_is_probe_req(hdr->frame_control))
		return TX_CONTINUE;

	if (tx->local->hw.flags & IEEE80211_HW_QUEUE_CONTROL)
		info->hw_queue = tx->sdata->vif.cab_queue;

	/* no stations in PS mode */
	if (!atomic_read(&ps->num_sta_ps))
		return TX_CONTINUE;

	info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;

	/* device releases frame after DTIM beacon */
	if (!(tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING))
		return TX_CONTINUE;

	/* buffered in mac80211 */
	if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
		purge_old_ps_buffers(tx->local);

	if (skb_queue_len(&ps->bc_buf) >= AP_MAX_BC_BUFFER) {
		ps_dbg(tx->sdata,
		       "BC TX buffer full - dropping the oldest frame\n");
		dev_kfree_skb(skb_dequeue(&ps->bc_buf));
	} else
		tx->local->total_ps_buffered++;

	skb_queue_tail(&ps->bc_buf, tx->skb);

	return TX_QUEUED;
}

static int ieee80211_use_mfp(__le16 fc, struct sta_info *sta,
			     struct sk_buff *skb)
{
	if (!ieee80211_is_mgmt(fc))
		return 0;

	if (sta == NULL || !test_sta_flag(sta, WLAN_STA_MFP))
		return 0;

	if (!ieee80211_is_robust_mgmt_frame(skb))
		return 0;

	return 1;
}

static ieee80211_tx_result
ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
{
	struct sta_info *sta = tx->sta;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
	struct ieee80211_local *local = tx->local;

	if (unlikely(!sta))
		return TX_CONTINUE;

	if (unlikely((test_sta_flag(sta, WLAN_STA_PS_STA) ||
		      test_sta_flag(sta, WLAN_STA_PS_DRIVER) ||
		      test_sta_flag(sta, WLAN_STA_PS_DELIVER)) &&
		     !(info->flags & IEEE80211_TX_CTL_NO_PS_BUFFER))) {
		int ac = skb_get_queue_mapping(tx->skb);

		if (ieee80211_is_mgmt(hdr->frame_control) &&
		    !ieee80211_is_bufferable_mmpdu(hdr->frame_control)) {
			info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
			return TX_CONTINUE;
		}

		ps_dbg(sta->sdata, "STA %pM aid %d: PS buffer for AC %d\n",
		       sta->sta.addr, sta->sta.aid, ac);
		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
			purge_old_ps_buffers(tx->local);

		/* sync with ieee80211_sta_ps_deliver_wakeup */
		spin_lock(&sta->ps_lock);
		/*
		 * STA woke up the meantime and all the frames on ps_tx_buf have
		 * been queued to pending queue. No reordering can happen, go
		 * ahead and Tx the packet.
		 */
		if (!test_sta_flag(sta, WLAN_STA_PS_STA) &&
		    !test_sta_flag(sta, WLAN_STA_PS_DRIVER) &&
		    !test_sta_flag(sta, WLAN_STA_PS_DELIVER)) {
			spin_unlock(&sta->ps_lock);
			return TX_CONTINUE;
		}

		if (skb_queue_len(&sta->ps_tx_buf[ac]) >= STA_MAX_TX_BUFFER) {
			struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf[ac]);
			ps_dbg(tx->sdata,
			       "STA %pM TX buffer for AC %d full - dropping oldest frame\n",
			       sta->sta.addr, ac);
			ieee80211_free_txskb(&local->hw, old);
		} else
			tx->local->total_ps_buffered++;

		info->control.jiffies = jiffies;
		info->control.vif = &tx->sdata->vif;
		info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
		info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
		skb_queue_tail(&sta->ps_tx_buf[ac], tx->skb);
		spin_unlock(&sta->ps_lock);

		if (!timer_pending(&local->sta_cleanup))
			mod_timer(&local->sta_cleanup,
				  round_jiffies(jiffies +
						STA_INFO_CLEANUP_INTERVAL));

		/*
		 * We queued up some frames, so the TIM bit might
		 * need to be set, recalculate it.
		 */
		sta_info_recalc_tim(sta);

		return TX_QUEUED;
	} else if (unlikely(test_sta_flag(sta, WLAN_STA_PS_STA))) {
		ps_dbg(tx->sdata,
		       "STA %pM in PS mode, but polling/in SP -> send frame\n",
		       sta->sta.addr);
	}

	return TX_CONTINUE;
}

static ieee80211_tx_result debug_noinline
ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
{
	if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
		return TX_CONTINUE;

	if (tx->flags & IEEE80211_TX_UNICAST)
		return ieee80211_tx_h_unicast_ps_buf(tx);
	else
		return ieee80211_tx_h_multicast_ps_buf(tx);
}

static ieee80211_tx_result debug_noinline
ieee80211_tx_h_check_control_port_protocol(struct ieee80211_tx_data *tx)
{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);

	if (unlikely(tx->sdata->control_port_protocol == tx->skb->protocol)) {
		if (tx->sdata->control_port_no_encrypt)
			info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
		info->control.flags |= IEEE80211_TX_CTRL_PORT_CTRL_PROTO;
		info->flags |= IEEE80211_TX_CTL_USE_MINRATE;
	}

	return TX_CONTINUE;
}

static ieee80211_tx_result debug_noinline
ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
{
	struct ieee80211_key *key;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;

	if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT))
		tx->key = NULL;
	else if (tx->sta &&
		 (key = rcu_dereference(tx->sta->ptk[tx->sta->ptk_idx])))
		tx->key = key;
	else if (ieee80211_is_mgmt(hdr->frame_control) &&
		 is_multicast_ether_addr(hdr->addr1) &&
		 ieee80211_is_robust_mgmt_frame(tx->skb) &&
		 (key = rcu_dereference(tx->sdata->default_mgmt_key)))
		tx->key = key;
	else if (is_multicast_ether_addr(hdr->addr1) &&
		 (key = rcu_dereference(tx->sdata->default_multicast_key)))
		tx->key = key;
	else if (!is_multicast_ether_addr(hdr->addr1) &&
		 (key = rcu_dereference(tx->sdata->default_unicast_key)))
		tx->key = key;
	else
		tx->key = NULL;

	if (tx->key) {
		bool skip_hw = false;

		tx->key->tx_rx_count++;
		/* TODO: add threshold stuff again */

		switch (tx->key->conf.cipher) {
		case WLAN_CIPHER_SUITE_WEP40:
		case WLAN_CIPHER_SUITE_WEP104:
		case WLAN_CIPHER_SUITE_TKIP:
			if (!ieee80211_is_data_present(hdr->frame_control))
				tx->key = NULL;
			break;
		case WLAN_CIPHER_SUITE_CCMP:
		case WLAN_CIPHER_SUITE_CCMP_256:
		case WLAN_CIPHER_SUITE_GCMP:
		case WLAN_CIPHER_SUITE_GCMP_256:
			if (!ieee80211_is_data_present(hdr->frame_control) &&
			    !ieee80211_use_mfp(hdr->frame_control, tx->sta,
					       tx->skb))
				tx->key = NULL;
			else
				skip_hw = (tx->key->conf.flags &
					   IEEE80211_KEY_FLAG_SW_MGMT_TX) &&
					ieee80211_is_mgmt(hdr->frame_control);
			break;
		case WLAN_CIPHER_SUITE_AES_CMAC:
		case WLAN_CIPHER_SUITE_BIP_CMAC_256:
		case WLAN_CIPHER_SUITE_BIP_GMAC_128:
		case WLAN_CIPHER_SUITE_BIP_GMAC_256:
			if (!ieee80211_is_mgmt(hdr->frame_control))
				tx->key = NULL;
			break;
		}

		if (unlikely(tx->key && tx->key->flags & KEY_FLAG_TAINTED &&
			     !ieee80211_is_deauth(hdr->frame_control)))
			return TX_DROP;

		if (!skip_hw && tx->key &&
		    tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
			info->control.hw_key = &tx->key->conf;
	}

	return TX_CONTINUE;
}

static ieee80211_tx_result debug_noinline
ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
	struct ieee80211_hdr *hdr = (void *)tx->skb->data;
	struct ieee80211_supported_band *sband;
	u32 len;
	struct ieee80211_tx_rate_control txrc;
	struct ieee80211_sta_rates *ratetbl = NULL;
	bool assoc = false;

	memset(&txrc, 0, sizeof(txrc));

	sband = tx->local->hw.wiphy->bands[info->band];

	len = min_t(u32, tx->skb->len + FCS_LEN,
			 tx->local->hw.wiphy->frag_threshold);

	/* set up the tx rate control struct we give the RC algo */
	txrc.hw = &tx->local->hw;
	txrc.sband = sband;
	txrc.bss_conf = &tx->sdata->vif.bss_conf;
	txrc.skb = tx->skb;
	txrc.reported_rate.idx = -1;
	txrc.rate_idx_mask = tx->sdata->rc_rateidx_mask[info->band];
	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
		txrc.max_rate_idx = -1;
	else
		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;

	if (tx->sdata->rc_has_mcs_mask[info->band])
		txrc.rate_idx_mcs_mask =
			tx->sdata->rc_rateidx_mcs_mask[info->band];

	txrc.bss = (tx->sdata->vif.type == NL80211_IFTYPE_AP ||
		    tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
		    tx->sdata->vif.type == NL80211_IFTYPE_ADHOC);

	/* set up RTS protection if desired */
	if (len > tx->local->hw.wiphy->rts_threshold) {
		txrc.rts = true;
	}

	info->control.use_rts = txrc.rts;
	info->control.use_cts_prot = tx->sdata->vif.bss_conf.use_cts_prot;

	/*
	 * Use short preamble if the BSS can handle it, but not for
	 * management frames unless we know the receiver can handle
	 * that -- the management frame might be to a station that
	 * just wants a probe response.
	 */
	if (tx->sdata->vif.bss_conf.use_short_preamble &&
	    (ieee80211_is_data(hdr->frame_control) ||
	     (tx->sta && test_sta_flag(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
		txrc.short_preamble = true;

	info->control.short_preamble = txrc.short_preamble;

	if (tx->sta)
		assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);

	/*
	 * Lets not bother rate control if we're associated and cannot
	 * talk to the sta. This should not happen.
	 */
	if (WARN(test_bit(SCAN_SW_SCANNING, &tx->local->scanning) && assoc &&
		 !rate_usable_index_exists(sband, &tx->sta->sta),
		 "%s: Dropped data frame as no usable bitrate found while "
		 "scanning and associated. Target station: "
		 "%pM on %d GHz band\n",
		 tx->sdata->name, hdr->addr1,
		 info->band ? 5 : 2))
		return TX_DROP;

	/*
	 * If we're associated with the sta at this point we know we can at
	 * least send the frame at the lowest bit rate.
	 */
	rate_control_get_rate(tx->sdata, tx->sta, &txrc);

	if (tx->sta && !info->control.skip_table)
		ratetbl = rcu_dereference(tx->sta->sta.rates);

	if (unlikely(info->control.rates[0].idx < 0)) {
		if (ratetbl) {
			struct ieee80211_tx_rate rate = {
				.idx = ratetbl->rate[0].idx,
				.flags = ratetbl->rate[0].flags,
				.count = ratetbl->rate[0].count
			};

			if (ratetbl->rate[0].idx < 0)
				return TX_DROP;

			tx->rate = rate;
		} else {
			return TX_DROP;
		}
	} else {
		tx->rate = info->control.rates[0];
	}

	if (txrc.reported_rate.idx < 0) {
		txrc.reported_rate = tx->rate;
		if (tx->sta && ieee80211_is_data(hdr->frame_control))
			tx->sta->last_tx_rate = txrc.reported_rate;
	} else if (tx->sta)
		tx->sta->last_tx_rate = txrc.reported_rate;

	if (ratetbl)
		return TX_CONTINUE;

	if (unlikely(!info->control.rates[0].count))
		info->control.rates[0].count = 1;

	if (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
			 (info->flags & IEEE80211_TX_CTL_NO_ACK)))
		info->control.rates[0].count = 1;

	return TX_CONTINUE;
}

static __le16 ieee80211_tx_next_seq(struct sta_info *sta, int tid)
{
	u16 *seq = &sta->tid_seq[tid];
	__le16 ret = cpu_to_le16(*seq);

	/* Increase the sequence number. */
	*seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ;

	return ret;
}

static ieee80211_tx_result debug_noinline
ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
	u8 *qc;
	int tid;

	/*
	 * Packet injection may want to control the sequence
	 * number, if we have no matching interface then we
	 * neither assign one ourselves nor ask the driver to.
	 */
	if (unlikely(info->control.vif->type == NL80211_IFTYPE_MONITOR))
		return TX_CONTINUE;

	if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
		return TX_CONTINUE;

	if (ieee80211_hdrlen(hdr->frame_control) < 24)
		return TX_CONTINUE;

	if (ieee80211_is_qos_nullfunc(hdr->frame_control))
		return TX_CONTINUE;

	/*
	 * Anything but QoS data that has a sequence number field
	 * (is long enough) gets a sequence number from the global
	 * counter.  QoS data frames with a multicast destination
	 * also use the global counter (802.11-2012 9.3.2.10).
	 */
	if (!ieee80211_is_data_qos(hdr->frame_control) ||
	    is_multicast_ether_addr(hdr->addr1)) {
		/* driver should assign sequence number */
		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
		/* for pure STA mode without beacons, we can do it */
		hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
		tx->sdata->sequence_number += 0x10;
		if (tx->sta)
			tx->sta->tx_msdu[IEEE80211_NUM_TIDS]++;
		return TX_CONTINUE;
	}

	/*
	 * This should be true for injected/management frames only, for
	 * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ
	 * above since they are not QoS-data frames.
	 */
	if (!tx->sta)
		return TX_CONTINUE;

	/* include per-STA, per-TID sequence counter */

	qc = ieee80211_get_qos_ctl(hdr);
	tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
	tx->sta->tx_msdu[tid]++;

	if (!tx->sta->sta.txq[0])
		hdr->seq_ctrl = ieee80211_tx_next_seq(tx->sta, tid);

	return TX_CONTINUE;
}

static int ieee80211_fragment(struct ieee80211_tx_data *tx,
			      struct sk_buff *skb, int hdrlen,
			      int frag_threshold)
{
	struct ieee80211_local *local = tx->local;
	struct ieee80211_tx_info *info;
	struct sk_buff *tmp;
	int per_fragm = frag_threshold - hdrlen - FCS_LEN;
	int pos = hdrlen + per_fragm;
	int rem = skb->len - hdrlen - per_fragm;

	if (WARN_ON(rem < 0))
		return -EINVAL;

	/* first fragment was already added to queue by caller */

	while (rem) {
		int fraglen = per_fragm;

		if (fraglen > rem)
			fraglen = rem;
		rem -= fraglen;
		tmp = dev_alloc_skb(local->tx_headroom +
				    frag_threshold +
				    tx->sdata->encrypt_headroom +
				    IEEE80211_ENCRYPT_TAILROOM);
		if (!tmp)
			return -ENOMEM;

		__skb_queue_tail(&tx->skbs, tmp);

		skb_reserve(tmp,
			    local->tx_headroom + tx->sdata->encrypt_headroom);

		/* copy control information */
		memcpy(tmp->cb, skb->cb, sizeof(tmp->cb));

		info = IEEE80211_SKB_CB(tmp);
		info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
				 IEEE80211_TX_CTL_FIRST_FRAGMENT);

		if (rem)
			info->flags |= IEEE80211_TX_CTL_MORE_FRAMES;

		skb_copy_queue_mapping(tmp, skb);
		tmp->priority = skb->priority;
		tmp->dev = skb->dev;

		/* copy header and data */
		memcpy(skb_put(tmp, hdrlen), skb->data, hdrlen);
		memcpy(skb_put(tmp, fraglen), skb->data + pos, fraglen);

		pos += fraglen;
	}

	/* adjust first fragment's length */
	skb_trim(skb, hdrlen + per_fragm);
	return 0;
}

static ieee80211_tx_result debug_noinline
ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
{
	struct sk_buff *skb = tx->skb;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ieee80211_hdr *hdr = (void *)skb->data;
	int frag_threshold = tx->local->hw.wiphy->frag_threshold;
	int hdrlen;
	int fragnum;

	/* no matter what happens, tx->skb moves to tx->skbs */
	__skb_queue_tail(&tx->skbs, skb);
	tx->skb = NULL;

	if (info->flags & IEEE80211_TX_CTL_DONTFRAG)
		return TX_CONTINUE;

	if (tx->local->ops->set_frag_threshold)
		return TX_CONTINUE;

	/*
	 * Warn when submitting a fragmented A-MPDU frame and drop it.
	 * This scenario is handled in ieee80211_tx_prepare but extra
	 * caution taken here as fragmented ampdu may cause Tx stop.
	 */
	if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
		return TX_DROP;

	hdrlen = ieee80211_hdrlen(hdr->frame_control);

	/* internal error, why isn't DONTFRAG set? */
	if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
		return TX_DROP;

	/*
	 * Now fragment the frame. This will allocate all the fragments and
	 * chain them (using skb as the first fragment) to skb->next.
	 * During transmission, we will remove the successfully transmitted
	 * fragments from this list. When the low-level driver rejects one
	 * of the fragments then we will simply pretend to accept the skb
	 * but store it away as pending.
	 */
	if (ieee80211_fragment(tx, skb, hdrlen, frag_threshold))
		return TX_DROP;

	/* update duration/seq/flags of fragments */
	fragnum = 0;

	skb_queue_walk(&tx->skbs, skb) {
		const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);

		hdr = (void *)skb->data;
		info = IEEE80211_SKB_CB(skb);

		if (!skb_queue_is_last(&tx->skbs, skb)) {
			hdr->frame_control |= morefrags;
			/*
			 * No multi-rate retries for fragmented frames, that
			 * would completely throw off the NAV at other STAs.
			 */
			info->control.rates[1].idx = -1;
			info->control.rates[2].idx = -1;
			info->control.rates[3].idx = -1;
			BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 4);
			info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
		} else {
			hdr->frame_control &= ~morefrags;
		}
		hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
		fragnum++;
	}

	return TX_CONTINUE;
}

static ieee80211_tx_result debug_noinline
ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
{
	struct sk_buff *skb;
	int ac = -1;

	if (!tx->sta)
		return TX_CONTINUE;

	skb_queue_walk(&tx->skbs, skb) {
		ac = skb_get_queue_mapping(skb);
		tx->sta->tx_bytes[ac] += skb->len;
	}
	if (ac >= 0)
		tx->sta->tx_packets[ac]++;

	return TX_CONTINUE;
}

static ieee80211_tx_result debug_noinline
ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
{
	if (!tx->key)
		return TX_CONTINUE;

	switch (tx->key->conf.cipher) {
	case WLAN_CIPHER_SUITE_WEP40:
	case WLAN_CIPHER_SUITE_WEP104:
		return ieee80211_crypto_wep_encrypt(tx);
	case WLAN_CIPHER_SUITE_TKIP:
		return ieee80211_crypto_tkip_encrypt(tx);
	case WLAN_CIPHER_SUITE_CCMP:
		return ieee80211_crypto_ccmp_encrypt(
			tx, IEEE80211_CCMP_MIC_LEN);
	case WLAN_CIPHER_SUITE_CCMP_256:
		return ieee80211_crypto_ccmp_encrypt(
			tx, IEEE80211_CCMP_256_MIC_LEN);
	case WLAN_CIPHER_SUITE_AES_CMAC:
		return ieee80211_crypto_aes_cmac_encrypt(tx);
	case WLAN_CIPHER_SUITE_BIP_CMAC_256:
		return ieee80211_crypto_aes_cmac_256_encrypt(tx);
	case WLAN_CIPHER_SUITE_BIP_GMAC_128:
	case WLAN_CIPHER_SUITE_BIP_GMAC_256:
		return ieee80211_crypto_aes_gmac_encrypt(tx);
	case WLAN_CIPHER_SUITE_GCMP:
	case WLAN_CIPHER_SUITE_GCMP_256:
		return ieee80211_crypto_gcmp_encrypt(tx);
	default:
		return ieee80211_crypto_hw_encrypt(tx);
	}

	return TX_DROP;
}

static ieee80211_tx_result debug_noinline
ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
{
	struct sk_buff *skb;
	struct ieee80211_hdr *hdr;
	int next_len;
	bool group_addr;

	skb_queue_walk(&tx->skbs, skb) {
		hdr = (void *) skb->data;
		if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
			break; /* must not overwrite AID */
		if (!skb_queue_is_last(&tx->skbs, skb)) {
			struct sk_buff *next = skb_queue_next(&tx->skbs, skb);
			next_len = next->len;
		} else
			next_len = 0;
		group_addr = is_multicast_ether_addr(hdr->addr1);

		hdr->duration_id =
			ieee80211_duration(tx, skb, group_addr, next_len);
	}

	return TX_CONTINUE;
}

/* actual transmit path */

static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,
				  struct sk_buff *skb,
				  struct ieee80211_tx_info *info,
				  struct tid_ampdu_tx *tid_tx,
				  int tid)
{
	bool queued = false;
	bool reset_agg_timer = false;
	struct sk_buff *purge_skb = NULL;

	if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
		info->flags |= IEEE80211_TX_CTL_AMPDU;
		reset_agg_timer = true;
	} else if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
		/*
		 * nothing -- this aggregation session is being started
		 * but that might still fail with the driver
		 */
	} else if (!tx->sta->sta.txq[tid]) {
		spin_lock(&tx->sta->lock);
		/*
		 * Need to re-check now, because we may get here
		 *
		 *  1) in the window during which the setup is actually
		 *     already done, but not marked yet because not all
		 *     packets are spliced over to the driver pending
		 *     queue yet -- if this happened we acquire the lock
		 *     either before or after the splice happens, but
		 *     need to recheck which of these cases happened.
		 *
		 *  2) during session teardown, if the OPERATIONAL bit
		 *     was cleared due to the teardown but the pointer
		 *     hasn't been assigned NULL yet (or we loaded it
		 *     before it was assigned) -- in this case it may
		 *     now be NULL which means we should just let the
		 *     packet pass through because splicing the frames
		 *     back is already done.
		 */
		tid_tx = rcu_dereference_protected_tid_tx(tx->sta, tid);

		if (!tid_tx) {
			/* do nothing, let packet pass through */
		} else if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
			info->flags |= IEEE80211_TX_CTL_AMPDU;
			reset_agg_timer = true;
		} else {
			queued = true;
			info->control.vif = &tx->sdata->vif;
			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
			info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
			__skb_queue_tail(&tid_tx->pending, skb);
			if (skb_queue_len(&tid_tx->pending) > STA_MAX_TX_BUFFER)
				purge_skb = __skb_dequeue(&tid_tx->pending);
		}
		spin_unlock(&tx->sta->lock);

		if (purge_skb)
			ieee80211_free_txskb(&tx->local->hw, purge_skb);
	}

	/* reset session timer */
	if (reset_agg_timer && tid_tx->timeout)
		tid_tx->last_tx = jiffies;

	return queued;
}

/*
 * initialises @tx
 * pass %NULL for the station if unknown, a valid pointer if known
 * or an ERR_PTR() if the station is known not to exist
 */
static ieee80211_tx_result
ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
		     struct ieee80211_tx_data *tx,
		     struct sta_info *sta, struct sk_buff *skb)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_hdr *hdr;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	int tid;
	u8 *qc;

	memset(tx, 0, sizeof(*tx));
	tx->skb = skb;
	tx->local = local;
	tx->sdata = sdata;
	__skb_queue_head_init(&tx->skbs);

	/*
	 * If this flag is set to true anywhere, and we get here,
	 * we are doing the needed processing, so remove the flag
	 * now.
	 */
	info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;

	hdr = (struct ieee80211_hdr *) skb->data;

	if (likely(sta)) {
		if (!IS_ERR(sta))
			tx->sta = sta;
	} else {
		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
			tx->sta = rcu_dereference(sdata->u.vlan.sta);
			if (!tx->sta && sdata->wdev.use_4addr)
				return TX_DROP;
		} else if (info->flags & (IEEE80211_TX_INTFL_NL80211_FRAME_TX |
					  IEEE80211_TX_CTL_INJECTED) ||
			   tx->sdata->control_port_protocol == tx->skb->protocol) {
			tx->sta = sta_info_get_bss(sdata, hdr->addr1);
		}
		if (!tx->sta && !is_multicast_ether_addr(hdr->addr1))
			tx->sta = sta_info_get(sdata, hdr->addr1);
	}

	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
	    !ieee80211_is_qos_nullfunc(hdr->frame_control) &&
	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) &&
	    !(local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW)) {
		struct tid_ampdu_tx *tid_tx;

		qc = ieee80211_get_qos_ctl(hdr);
		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;

		tid_tx = rcu_dereference(tx->sta->ampdu_mlme.tid_tx[tid]);
		if (tid_tx) {
			bool queued;

			queued = ieee80211_tx_prep_agg(tx, skb, info,
						       tid_tx, tid);

			if (unlikely(queued))
				return TX_QUEUED;
		}
	}

	if (is_multicast_ether_addr(hdr->addr1)) {
		tx->flags &= ~IEEE80211_TX_UNICAST;
		info->flags |= IEEE80211_TX_CTL_NO_ACK;
	} else
		tx->flags |= IEEE80211_TX_UNICAST;

	if (!(info->flags & IEEE80211_TX_CTL_DONTFRAG)) {
		if (!(tx->flags & IEEE80211_TX_UNICAST) ||
		    skb->len + FCS_LEN <= local->hw.wiphy->frag_threshold ||
		    info->flags & IEEE80211_TX_CTL_AMPDU)
			info->flags |= IEEE80211_TX_CTL_DONTFRAG;
	}

	if (!tx->sta)
		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
	else if (test_and_clear_sta_flag(tx->sta, WLAN_STA_CLEAR_PS_FILT))
		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;

	info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;

	return TX_CONTINUE;
}

static void ieee80211_drv_tx(struct ieee80211_local *local,
			     struct ieee80211_vif *vif,
			     struct ieee80211_sta *pubsta,
			     struct sk_buff *skb)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ieee80211_tx_control control = {
		.sta = pubsta,
	};
	struct ieee80211_txq *txq = NULL;
	struct txq_info *txqi;
	u8 ac;

	if (info->control.flags & IEEE80211_TX_CTRL_PS_RESPONSE)
		goto tx_normal;

	if (!ieee80211_is_data(hdr->frame_control))
		goto tx_normal;

	if (pubsta) {
		u8 tid = skb->priority & IEEE80211_QOS_CTL_TID_MASK;

		txq = pubsta->txq[tid];
	} else if (vif) {
		txq = vif->txq;
	}

	if (!txq)
		goto tx_normal;

	ac = txq->ac;
	txqi = to_txq_info(txq);
	atomic_inc(&sdata->txqs_len[ac]);
	if (atomic_read(&sdata->txqs_len[ac]) >= local->hw.txq_ac_max_pending)
		netif_stop_subqueue(sdata->dev, ac);

	skb_queue_tail(&txqi->queue, skb);
	drv_wake_tx_queue(local, txqi);

	return;

tx_normal:
	drv_tx(local, &control, skb);
}

struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw,
				     struct ieee80211_txq *txq)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_sub_if_data *sdata = vif_to_sdata(txq->vif);
	struct txq_info *txqi = container_of(txq, struct txq_info, txq);
	struct ieee80211_hdr *hdr;
	struct sk_buff *skb = NULL;
	u8 ac = txq->ac;

	spin_lock_bh(&txqi->queue.lock);

	if (test_bit(IEEE80211_TXQ_STOP, &txqi->flags))
		goto out;

	skb = __skb_dequeue(&txqi->queue);
	if (!skb)
		goto out;

	atomic_dec(&sdata->txqs_len[ac]);
	if (__netif_subqueue_stopped(sdata->dev, ac))
		ieee80211_propagate_queue_wake(local, sdata->vif.hw_queue[ac]);

	hdr = (struct ieee80211_hdr *)skb->data;
	if (txq->sta && ieee80211_is_data_qos(hdr->frame_control)) {
		struct sta_info *sta = container_of(txq->sta, struct sta_info,
						    sta);
		struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);

		hdr->seq_ctrl = ieee80211_tx_next_seq(sta, txq->tid);
		if (test_bit(IEEE80211_TXQ_AMPDU, &txqi->flags))
			info->flags |= IEEE80211_TX_CTL_AMPDU;
		else
			info->flags &= ~IEEE80211_TX_CTL_AMPDU;
	}

out:
	spin_unlock_bh(&txqi->queue.lock);

	return skb;
}
EXPORT_SYMBOL(ieee80211_tx_dequeue);

static bool ieee80211_tx_frags(struct ieee80211_local *local,
			       struct ieee80211_vif *vif,
			       struct ieee80211_sta *sta,
			       struct sk_buff_head *skbs,
			       bool txpending)
{
	struct sk_buff *skb, *tmp;
	unsigned long flags;

	skb_queue_walk_safe(skbs, skb, tmp) {
		struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
		int q = info->hw_queue;

#ifdef CPTCFG_MAC80211_VERBOSE_DEBUG
		if (WARN_ON_ONCE(q >= local->hw.queues)) {
			__skb_unlink(skb, skbs);
			ieee80211_free_txskb(&local->hw, skb);
			continue;
		}
#endif

		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
		if (local->queue_stop_reasons[q] ||
		    (!txpending && !skb_queue_empty(&local->pending[q]))) {
			if (unlikely(info->flags &
				     IEEE80211_TX_INTFL_OFFCHAN_TX_OK)) {
				if (local->queue_stop_reasons[q] &
				    ~BIT(IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL)) {
					/*
					 * Drop off-channel frames if queues
					 * are stopped for any reason other
					 * than off-channel operation. Never
					 * queue them.
					 */
					spin_unlock_irqrestore(
						&local->queue_stop_reason_lock,
						flags);
					ieee80211_purge_tx_queue(&local->hw,
								 skbs);
					return true;
				}
			} else {

				/*
				 * Since queue is stopped, queue up frames for
				 * later transmission from the tx-pending
				 * tasklet when the queue is woken again.
				 */
				if (txpending)
					skb_queue_splice_init(skbs,
							      &local->pending[q]);
				else
					skb_queue_splice_tail_init(skbs,
								   &local->pending[q]);

				spin_unlock_irqrestore(&local->queue_stop_reason_lock,
						       flags);
				return false;
			}
		}
		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);

		info->control.vif = vif;

		__skb_unlink(skb, skbs);
		ieee80211_drv_tx(local, vif, sta, skb);
	}

	return true;
}

/*
 * Returns false if the frame couldn't be transmitted but was queued instead.
 */
static bool __ieee80211_tx(struct ieee80211_local *local,
			   struct sk_buff_head *skbs, int led_len,
			   struct sta_info *sta, bool txpending)
{
	struct ieee80211_tx_info *info;
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_vif *vif;
	struct ieee80211_sta *pubsta;
	struct sk_buff *skb;
	bool result = true;
	__le16 fc;

	if (WARN_ON(skb_queue_empty(skbs)))
		return true;

	skb = skb_peek(skbs);
	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
	info = IEEE80211_SKB_CB(skb);
	sdata = vif_to_sdata(info->control.vif);
	if (sta && !sta->uploaded)
		sta = NULL;

	if (sta)
		pubsta = &sta->sta;
	else
		pubsta = NULL;

	switch (sdata->vif.type) {
	case NL80211_IFTYPE_MONITOR:
		if (sdata->u.mntr_flags & MONITOR_FLAG_ACTIVE) {
			vif = &sdata->vif;
			break;
		}
		sdata = rcu_dereference(local->monitor_sdata);
		if (sdata) {
			vif = &sdata->vif;
			info->hw_queue =
				vif->hw_queue[skb_get_queue_mapping(skb)];
		} else if (local->hw.flags & IEEE80211_HW_QUEUE_CONTROL) {
			dev_kfree_skb(skb);
			return true;
		} else
			vif = NULL;
		break;
	case NL80211_IFTYPE_AP_VLAN:
		sdata = container_of(sdata->bss,
				     struct ieee80211_sub_if_data, u.ap);
		/* fall through */
	default:
		vif = &sdata->vif;
		break;
	}

	result = ieee80211_tx_frags(local, vif, pubsta, skbs,
				    txpending);

	ieee80211_tpt_led_trig_tx(local, fc, led_len);

	WARN_ON_ONCE(!skb_queue_empty(skbs));

	return result;
}

/*
 * Invoke TX handlers, return 0 on success and non-zero if the
 * frame was dropped or queued.
 */
static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
	ieee80211_tx_result res = TX_DROP;

#define CALL_TXH(txh) \
	do {				\
		res = txh(tx);		\
		if (res != TX_CONTINUE)	\
			goto txh_done;	\
	} while (0)

	CALL_TXH(ieee80211_tx_h_dynamic_ps);
	CALL_TXH(ieee80211_tx_h_check_assoc);
	CALL_TXH(ieee80211_tx_h_ps_buf);
	CALL_TXH(ieee80211_tx_h_check_control_port_protocol);
	CALL_TXH(ieee80211_tx_h_select_key);
	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
		CALL_TXH(ieee80211_tx_h_rate_ctrl);

	if (unlikely(info->flags & IEEE80211_TX_INTFL_RETRANSMISSION)) {
		__skb_queue_tail(&tx->skbs, tx->skb);
		tx->skb = NULL;
		goto txh_done;
	}

	CALL_TXH(ieee80211_tx_h_michael_mic_add);
	CALL_TXH(ieee80211_tx_h_sequence);
	CALL_TXH(ieee80211_tx_h_fragment);
	/* handlers after fragment must be aware of tx info fragmentation! */
	CALL_TXH(ieee80211_tx_h_stats);
	CALL_TXH(ieee80211_tx_h_encrypt);
	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
		CALL_TXH(ieee80211_tx_h_calculate_duration);
#undef CALL_TXH

 txh_done:
	if (unlikely(res == TX_DROP)) {
		I802_DEBUG_INC(tx->local->tx_handlers_drop);
		if (tx->skb)
			ieee80211_free_txskb(&tx->local->hw, tx->skb);
		else
			ieee80211_purge_tx_queue(&tx->local->hw, &tx->skbs);
		return -1;
	} else if (unlikely(res == TX_QUEUED)) {
		I802_DEBUG_INC(tx->local->tx_handlers_queued);
		return -1;
	}

	return 0;
}

bool ieee80211_tx_prepare_skb(struct ieee80211_hw *hw,
			      struct ieee80211_vif *vif, struct sk_buff *skb,
			      int band, struct ieee80211_sta **sta)
{
	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ieee80211_tx_data tx;
	struct sk_buff *skb2;

	if (ieee80211_tx_prepare(sdata, &tx, NULL, skb) == TX_DROP)
		return false;

	info->band = band;
	info->control.vif = vif;
	info->hw_queue = vif->hw_queue[skb_get_queue_mapping(skb)];

	if (invoke_tx_handlers(&tx))
		return false;

	if (sta) {
		if (tx.sta)
			*sta = &tx.sta->sta;
		else
			*sta = NULL;
	}

	/* this function isn't suitable for fragmented data frames */
	skb2 = __skb_dequeue(&tx.skbs);
	if (WARN_ON(skb2 != skb || !skb_queue_empty(&tx.skbs))) {
		ieee80211_free_txskb(hw, skb2);
		ieee80211_purge_tx_queue(hw, &tx.skbs);
		return false;
	}

	return true;
}
EXPORT_SYMBOL(ieee80211_tx_prepare_skb);

/*
 * Returns false if the frame couldn't be transmitted but was queued instead.
 */
static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata,
			 struct sta_info *sta, struct sk_buff *skb,
			 bool txpending)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_tx_data tx;
	ieee80211_tx_result res_prepare;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	bool result = true;
	int led_len;

	if (unlikely(skb->len < 10)) {
		dev_kfree_skb(skb);
		return true;
	}

	/* initialises tx */
	led_len = skb->len;
	res_prepare = ieee80211_tx_prepare(sdata, &tx, sta, skb);

	if (unlikely(res_prepare == TX_DROP)) {
		ieee80211_free_txskb(&local->hw, skb);
		return true;
	} else if (unlikely(res_prepare == TX_QUEUED)) {
		return true;
	}

	/* set up hw_queue value early */
	if (!(info->flags & IEEE80211_TX_CTL_TX_OFFCHAN) ||
	    !(local->hw.flags & IEEE80211_HW_QUEUE_CONTROL))
		info->hw_queue =
			sdata->vif.hw_queue[skb_get_queue_mapping(skb)];

	if (!invoke_tx_handlers(&tx))
		result = __ieee80211_tx(local, &tx.skbs, led_len,
					tx.sta, txpending);

	return result;
}

/* device xmit handlers */

static int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata,
				struct sk_buff *skb,
				int head_need, bool may_encrypt)
{
	struct ieee80211_local *local = sdata->local;
	int tail_need = 0;

	if (may_encrypt && sdata->crypto_tx_tailroom_needed_cnt) {
		tail_need = IEEE80211_ENCRYPT_TAILROOM;
		tail_need -= skb_tailroom(skb);
		tail_need = max_t(int, tail_need, 0);
	}

	if (skb_cloned(skb) &&
	    (!(local->hw.flags & IEEE80211_HW_SUPPORTS_CLONED_SKBS) ||
	     !skb_clone_writable(skb, ETH_HLEN) ||
	     (may_encrypt && sdata->crypto_tx_tailroom_needed_cnt)))
		I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
	else if (head_need || tail_need)
		I802_DEBUG_INC(local->tx_expand_skb_head);
	else
		return 0;

	if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) {
		wiphy_debug(local->hw.wiphy,
			    "failed to reallocate TX buffer\n");
		return -ENOMEM;
	}

	return 0;
}

void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
		    struct sta_info *sta, struct sk_buff *skb)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	int headroom;
	bool may_encrypt;

	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);

	headroom = local->tx_headroom;
	if (may_encrypt)
		headroom += sdata->encrypt_headroom;
	headroom -= skb_headroom(skb);
	headroom = max_t(int, 0, headroom);

	if (ieee80211_skb_resize(sdata, skb, headroom, may_encrypt)) {
		ieee80211_free_txskb(&local->hw, skb);
		return;
	}

	hdr = (struct ieee80211_hdr *) skb->data;
	info->control.vif = &sdata->vif;

	if (ieee80211_vif_is_mesh(&sdata->vif)) {
		if (ieee80211_is_data(hdr->frame_control) &&
		    is_unicast_ether_addr(hdr->addr1)) {
			if (mesh_nexthop_resolve(sdata, skb))
				return; /* skb queued: don't free */
		} else {
			ieee80211_mps_set_frame_flags(sdata, NULL, hdr);
		}
	}

	ieee80211_set_qos_hdr(sdata, skb);
	ieee80211_tx(sdata, sta, skb, false);
}

static bool ieee80211_parse_tx_radiotap(struct sk_buff *skb)
{
	struct ieee80211_radiotap_iterator iterator;
	struct ieee80211_radiotap_header *rthdr =
		(struct ieee80211_radiotap_header *) skb->data;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len,
						   NULL);
	u16 txflags;

	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
		       IEEE80211_TX_CTL_DONTFRAG;

	/*
	 * for every radiotap entry that is present
	 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
	 * entries present, or -EINVAL on error)
	 */

	while (!ret) {
		ret = ieee80211_radiotap_iterator_next(&iterator);

		if (ret)
			continue;

		/* see if this argument is something we can use */
		switch (iterator.this_arg_index) {
		/*
		 * You must take care when dereferencing iterator.this_arg
		 * for multibyte types... the pointer is not aligned.  Use
		 * get_unaligned((type *)iterator.this_arg) to dereference
		 * iterator.this_arg for type "type" safely on all arches.
		*/
		case IEEE80211_RADIOTAP_FLAGS:
			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
				/*
				 * this indicates that the skb we have been
				 * handed has the 32-bit FCS CRC at the end...
				 * we should react to that by snipping it off
				 * because it will be recomputed and added
				 * on transmission
				 */
				if (skb->len < (iterator._max_length + FCS_LEN))
					return false;

				skb_trim(skb, skb->len - FCS_LEN);
			}
			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
				info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
				info->flags &= ~IEEE80211_TX_CTL_DONTFRAG;
			break;

		case IEEE80211_RADIOTAP_TX_FLAGS:
			txflags = get_unaligned_le16(iterator.this_arg);
			if (txflags & IEEE80211_RADIOTAP_F_TX_NOACK)
				info->flags |= IEEE80211_TX_CTL_NO_ACK;
			break;

		/*
		 * Please update the file
		 * Documentation/networking/mac80211-injection.txt
		 * when parsing new fields here.
		 */

		default:
			break;
		}
	}

	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
		return false;

	/*
	 * remove the radiotap header
	 * iterator->_max_length was sanity-checked against
	 * skb->len by iterator init
	 */
	skb_pull(skb, iterator._max_length);

	return true;
}

netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
					 struct net_device *dev)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_chanctx_conf *chanctx_conf;
	struct ieee80211_radiotap_header *prthdr =
		(struct ieee80211_radiotap_header *)skb->data;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ieee80211_hdr *hdr;
	struct ieee80211_sub_if_data *tmp_sdata, *sdata;
	struct cfg80211_chan_def *chandef;
	u16 len_rthdr;
	int hdrlen;

	/* check for not even having the fixed radiotap header part */
	if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
		goto fail; /* too short to be possibly valid */

	/* is it a header version we can trust to find length from? */
	if (unlikely(prthdr->it_version))
		goto fail; /* only version 0 is supported */

	/* then there must be a radiotap header with a length we can use */
	len_rthdr = ieee80211_get_radiotap_len(skb->data);

	/* does the skb contain enough to deliver on the alleged length? */
	if (unlikely(skb->len < len_rthdr))
		goto fail; /* skb too short for claimed rt header extent */

	/*
	 * fix up the pointers accounting for the radiotap
	 * header still being in there.  We are being given
	 * a precooked IEEE80211 header so no need for
	 * normal processing
	 */
	skb_set_mac_header(skb, len_rthdr);
	/*
	 * these are just fixed to the end of the rt area since we
	 * don't have any better information and at this point, nobody cares
	 */
	skb_set_network_header(skb, len_rthdr);
	skb_set_transport_header(skb, len_rthdr);

	if (skb->len < len_rthdr + 2)
		goto fail;

	hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
	hdrlen = ieee80211_hdrlen(hdr->frame_control);

	if (skb->len < len_rthdr + hdrlen)
		goto fail;

	/*
	 * Initialize skb->protocol if the injected frame is a data frame
	 * carrying a rfc1042 header
	 */
	if (ieee80211_is_data(hdr->frame_control) &&
	    skb->len >= len_rthdr + hdrlen + sizeof(rfc1042_header) + 2) {
		u8 *payload = (u8 *)hdr + hdrlen;

		if (ether_addr_equal(payload, rfc1042_header))
			skb->protocol = cpu_to_be16((payload[6] << 8) |
						    payload[7]);
	}

	memset(info, 0, sizeof(*info));

	info->flags = IEEE80211_TX_CTL_REQ_TX_STATUS |
		      IEEE80211_TX_CTL_INJECTED;

	/* process and remove the injection radiotap header */
	if (!ieee80211_parse_tx_radiotap(skb))
		goto fail;

	rcu_read_lock();

	/*
	 * We process outgoing injected frames that have a local address
	 * we handle as though they are non-injected frames.
	 * This code here isn't entirely correct, the local MAC address
	 * isn't always enough to find the interface to use; for proper
	 * VLAN/WDS support we will need a different mechanism (which
	 * likely isn't going to be monitor interfaces).
	 */
	sdata = IEEE80211_DEV_TO_SUB_IF(dev);

	list_for_each_entry_rcu(tmp_sdata, &local->interfaces, list) {
		if (!ieee80211_sdata_running(tmp_sdata))
			continue;
		if (tmp_sdata->vif.type == NL80211_IFTYPE_MONITOR ||
		    tmp_sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
		    tmp_sdata->vif.type == NL80211_IFTYPE_WDS)
			continue;
		if (ether_addr_equal(tmp_sdata->vif.addr, hdr->addr2)) {
			sdata = tmp_sdata;
			break;
		}
	}

	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
	if (!chanctx_conf) {
		tmp_sdata = rcu_dereference(local->monitor_sdata);
		if (tmp_sdata)
			chanctx_conf =
				rcu_dereference(tmp_sdata->vif.chanctx_conf);
	}

	if (chanctx_conf)
		chandef = &chanctx_conf->def;
	else if (!local->use_chanctx)
		chandef = &local->_oper_chandef;
	else
		goto fail_rcu;

	/*
	 * Frame injection is not allowed if beaconing is not allowed
	 * or if we need radar detection. Beaconing is usually not allowed when
	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
	 * Passive scan is also used in world regulatory domains where
	 * your country is not known and as such it should be treated as
	 * NO TX unless the channel is explicitly allowed in which case
	 * your current regulatory domain would not have the passive scan
	 * flag.
	 *
	 * Since AP mode uses monitor interfaces to inject/TX management
	 * frames we can make AP mode the exception to this rule once it
	 * supports radar detection as its implementation can deal with
	 * radar detection by itself. We can do that later by adding a
	 * monitor flag interfaces used for AP support.
	 */
	if (!cfg80211_reg_can_beacon(local->hw.wiphy, chandef,
				     sdata->vif.type))
		goto fail_rcu;

	info->band = chandef->chan->band;
	ieee80211_xmit(sdata, NULL, skb);
	rcu_read_unlock();

	return NETDEV_TX_OK;

fail_rcu:
	rcu_read_unlock();
fail:
	dev_kfree_skb(skb);
	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
}

static inline bool ieee80211_is_tdls_setup(struct sk_buff *skb)
{
	u16 ethertype = (skb->data[12] << 8) | skb->data[13];

	return ethertype == ETH_P_TDLS &&
	       skb->len > 14 &&
	       skb->data[14] == WLAN_TDLS_SNAP_RFTYPE;
}

static int ieee80211_lookup_ra_sta(struct ieee80211_sub_if_data *sdata,
				   struct sk_buff *skb,
				   struct sta_info **sta_out)
{
	struct sta_info *sta;

	switch (sdata->vif.type) {
	case NL80211_IFTYPE_AP_VLAN:
		sta = rcu_dereference(sdata->u.vlan.sta);
		if (sta) {
			*sta_out = sta;
			return 0;
		} else if (sdata->wdev.use_4addr) {
			return -ENOLINK;
		}
		/* fall through */
	case NL80211_IFTYPE_AP:
	case NL80211_IFTYPE_OCB:
	case NL80211_IFTYPE_ADHOC:
		if (is_multicast_ether_addr(skb->data)) {
			*sta_out = ERR_PTR(-ENOENT);
			return 0;
		}
		sta = sta_info_get_bss(sdata, skb->data);
		break;
	case NL80211_IFTYPE_WDS:
		sta = sta_info_get(sdata, sdata->u.wds.remote_addr);
		break;
#ifdef CPTCFG_MAC80211_MESH
	case NL80211_IFTYPE_MESH_POINT:
		/* determined much later */
		*sta_out = NULL;
		return 0;
#endif
	case NL80211_IFTYPE_STATION:
		if (sdata->wdev.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS) {
			sta = sta_info_get(sdata, skb->data);
			if (sta) {
				bool tdls_peer, tdls_auth;

				tdls_peer = test_sta_flag(sta,
							  WLAN_STA_TDLS_PEER);
				tdls_auth = test_sta_flag(sta,
						WLAN_STA_TDLS_PEER_AUTH);

				if (tdls_peer && tdls_auth) {
					*sta_out = sta;
					return 0;
				}

				/*
				 * TDLS link during setup - throw out frames to
				 * peer. Allow TDLS-setup frames to unauthorized
				 * peers for the special case of a link teardown
				 * after a TDLS sta is removed due to being
				 * unreachable.
				 */
				if (tdls_peer && !tdls_auth &&
				    !ieee80211_is_tdls_setup(skb))
					return -EINVAL;
			}

		}

		sta = sta_info_get(sdata, sdata->u.mgd.bssid);
		if (!sta)
			return -ENOLINK;
		break;
	default:
		return -EINVAL;
	}

	*sta_out = sta ?: ERR_PTR(-ENOENT);
	return 0;
}

/**
 * ieee80211_build_hdr - build 802.11 header in the given frame
 * @sdata: virtual interface to build the header for
 * @skb: the skb to build the header in
 * @info_flags: skb flags to set
 *
 * This function takes the skb with 802.3 header and reformats the header to
 * the appropriate IEEE 802.11 header based on which interface the packet is
 * being transmitted on.
 *
 * Note that this function also takes care of the TX status request and
 * potential unsharing of the SKB - this needs to be interleaved with the
 * header building.
 *
 * The function requires the read-side RCU lock held
 *
 * Returns: the (possibly reallocated) skb or an ERR_PTR() code
 */
static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
					   struct sk_buff *skb, u32 info_flags,
					   struct sta_info *sta)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_tx_info *info;
	int head_need;
	u16 ethertype, hdrlen,  meshhdrlen = 0;
	__le16 fc;
	struct ieee80211_hdr hdr;
	struct ieee80211s_hdr mesh_hdr __maybe_unused;
	struct mesh_path __maybe_unused *mppath = NULL, *mpath = NULL;
	const u8 *encaps_data;
	int encaps_len, skip_header_bytes;
	int nh_pos, h_pos;
	bool wme_sta = false, authorized = false;
	bool tdls_peer;
	bool multicast;
	u16 info_id = 0;
	struct ieee80211_chanctx_conf *chanctx_conf;
	struct ieee80211_sub_if_data *ap_sdata;
	enum ieee80211_band band;
	int ret;

	if (IS_ERR(sta))
		sta = NULL;

	/* convert Ethernet header to proper 802.11 header (based on
	 * operation mode) */
	ethertype = (skb->data[12] << 8) | skb->data[13];
	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);

	switch (sdata->vif.type) {
	case NL80211_IFTYPE_AP_VLAN:
		if (sdata->wdev.use_4addr) {
			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
			/* RA TA DA SA */
			memcpy(hdr.addr1, sta->sta.addr, ETH_ALEN);
			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
			memcpy(hdr.addr3, skb->data, ETH_ALEN);
			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
			hdrlen = 30;
			authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
			wme_sta = sta->sta.wme;
		}
		ap_sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
					u.ap);
		chanctx_conf = rcu_dereference(ap_sdata->vif.chanctx_conf);
		if (!chanctx_conf) {
			ret = -ENOTCONN;
			goto free;
		}
		band = chanctx_conf->def.chan->band;
		if (sdata->wdev.use_4addr)
			break;
		/* fall through */
	case NL80211_IFTYPE_AP:
		if (sdata->vif.type == NL80211_IFTYPE_AP)
			chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
		if (!chanctx_conf) {
			ret = -ENOTCONN;
			goto free;
		}
		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
		/* DA BSSID SA */
		memcpy(hdr.addr1, skb->data, ETH_ALEN);
		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
		hdrlen = 24;
		band = chanctx_conf->def.chan->band;
		break;
	case NL80211_IFTYPE_WDS:
		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
		/* RA TA DA SA */
		memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
		memcpy(hdr.addr3, skb->data, ETH_ALEN);
		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
		hdrlen = 30;
		/*
		 * This is the exception! WDS style interfaces are prohibited
		 * when channel contexts are in used so this must be valid
		 */
		band = local->hw.conf.chandef.chan->band;
		break;
#ifdef CPTCFG_MAC80211_MESH
	case NL80211_IFTYPE_MESH_POINT:
		if (!is_multicast_ether_addr(skb->data)) {
			struct sta_info *next_hop;
			bool mpp_lookup = true;

			mpath = mesh_path_lookup(sdata, skb->data);
			if (mpath) {
				mpp_lookup = false;
				next_hop = rcu_dereference(mpath->next_hop);
				if (!next_hop ||
				    !(mpath->flags & (MESH_PATH_ACTIVE |
						      MESH_PATH_RESOLVING)))
					mpp_lookup = true;
			}

			if (mpp_lookup)
				mppath = mpp_path_lookup(sdata, skb->data);

			if (mppath && mpath)
				mesh_path_del(mpath->sdata, mpath->dst);
		}

		/*
		 * Use address extension if it is a packet from
		 * another interface or if we know the destination
		 * is being proxied by a portal (i.e. portal address
		 * differs from proxied address)
		 */
		if (ether_addr_equal(sdata->vif.addr, skb->data + ETH_ALEN) &&
		    !(mppath && !ether_addr_equal(mppath->mpp, skb->data))) {
			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
					skb->data, skb->data + ETH_ALEN);
			meshhdrlen = ieee80211_new_mesh_header(sdata, &mesh_hdr,
							       NULL, NULL);
		} else {
			/* DS -> MBSS (802.11-2012 13.11.3.3).
			 * For unicast with unknown forwarding information,
			 * destination might be in the MBSS or if that fails
			 * forwarded to another mesh gate. In either case
			 * resolution will be handled in ieee80211_xmit(), so
			 * leave the original DA. This also works for mcast */
			const u8 *mesh_da = skb->data;

			if (mppath)
				mesh_da = mppath->mpp;
			else if (mpath)
				mesh_da = mpath->dst;

			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
					mesh_da, sdata->vif.addr);
			if (is_multicast_ether_addr(mesh_da))
				/* DA TA mSA AE:SA */
				meshhdrlen = ieee80211_new_mesh_header(
						sdata, &mesh_hdr,
						skb->data + ETH_ALEN, NULL);
			else
				/* RA TA mDA mSA AE:DA SA */
				meshhdrlen = ieee80211_new_mesh_header(
						sdata, &mesh_hdr, skb->data,
						skb->data + ETH_ALEN);

		}
		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
		if (!chanctx_conf) {
			ret = -ENOTCONN;
			goto free;
		}
		band = chanctx_conf->def.chan->band;
		break;
#endif
	case NL80211_IFTYPE_STATION:
		/* we already did checks when looking up the RA STA */
		tdls_peer = test_sta_flag(sta, WLAN_STA_TDLS_PEER);

		if (tdls_peer) {
			/* DA SA BSSID */
			memcpy(hdr.addr1, skb->data, ETH_ALEN);
			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
			memcpy(hdr.addr3, sdata->u.mgd.bssid, ETH_ALEN);
			hdrlen = 24;
		}  else if (sdata->u.mgd.use_4addr &&
			    cpu_to_be16(ethertype) != sdata->control_port_protocol) {
			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
					  IEEE80211_FCTL_TODS);
			/* RA TA DA SA */
			memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
			memcpy(hdr.addr3, skb->data, ETH_ALEN);
			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
			hdrlen = 30;
		} else {
			fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
			/* BSSID SA DA */
			memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
			memcpy(hdr.addr3, skb->data, ETH_ALEN);
			hdrlen = 24;
		}
		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
		if (!chanctx_conf) {
			ret = -ENOTCONN;
			goto free;
		}
		band = chanctx_conf->def.chan->band;
		break;
	case NL80211_IFTYPE_OCB:
		/* DA SA BSSID */
		memcpy(hdr.addr1, skb->data, ETH_ALEN);
		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
		eth_broadcast_addr(hdr.addr3);
		hdrlen = 24;
		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
		if (!chanctx_conf) {
			ret = -ENOTCONN;
			goto free;
		}
		band = chanctx_conf->def.chan->band;
		break;
	case NL80211_IFTYPE_ADHOC:
		/* DA SA BSSID */
		memcpy(hdr.addr1, skb->data, ETH_ALEN);
		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
		hdrlen = 24;
		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
		if (!chanctx_conf) {
			ret = -ENOTCONN;
			goto free;
		}
		band = chanctx_conf->def.chan->band;
		break;
	default:
		ret = -EINVAL;
		goto free;
	}

	multicast = is_multicast_ether_addr(hdr.addr1);

	/* sta is always NULL for mesh */
	if (sta) {
		authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
		wme_sta = sta->sta.wme;
	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
		/* For mesh, the use of the QoS header is mandatory */
		wme_sta = true;
	}

	/* receiver does QoS (which also means we do) use it */
	if (wme_sta) {
		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
		hdrlen += 2;
	}

	/*
	 * Drop unicast frames to unauthorised stations unless they are
	 * EAPOL frames from the local station.
	 */
	if (unlikely(!ieee80211_vif_is_mesh(&sdata->vif) &&
		     (sdata->vif.type != NL80211_IFTYPE_OCB) &&
		     !multicast && !authorized &&
		     (cpu_to_be16(ethertype) != sdata->control_port_protocol ||
		      !ether_addr_equal(sdata->vif.addr, skb->data + ETH_ALEN)))) {
#ifdef CPTCFG_MAC80211_VERBOSE_DEBUG
		net_info_ratelimited("%s: dropped frame to %pM (unauthorized port)\n",
				    sdata->name, hdr.addr1);
#endif

		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);

		ret = -EPERM;
		goto free;
	}

	if (unlikely(!multicast && skb->sk &&
		     skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS)) {
		struct sk_buff *ack_skb = skb_clone_sk(skb);

		if (ack_skb) {
			unsigned long flags;
			int id;

			spin_lock_irqsave(&local->ack_status_lock, flags);
			id = idr_alloc(&local->ack_status_frames, ack_skb,
				       1, 0x10000, GFP_ATOMIC);
			spin_unlock_irqrestore(&local->ack_status_lock, flags);

			if (id >= 0) {
				info_id = id;
				info_flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
			} else {
				kfree_skb(ack_skb);
			}
		}
	}

	/*
	 * If the skb is shared we need to obtain our own copy.
	 */
	if (skb_shared(skb)) {
		struct sk_buff *tmp_skb = skb;

		/* can't happen -- skb is a clone if info_id != 0 */
		WARN_ON(info_id);

		skb = skb_clone(skb, GFP_ATOMIC);
		kfree_skb(tmp_skb);

		if (!skb) {
			ret = -ENOMEM;
			goto free;
		}
	}

	hdr.frame_control = fc;
	hdr.duration_id = 0;
	hdr.seq_ctrl = 0;

	skip_header_bytes = ETH_HLEN;
	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
		encaps_data = bridge_tunnel_header;
		encaps_len = sizeof(bridge_tunnel_header);
		skip_header_bytes -= 2;
	} else if (ethertype >= ETH_P_802_3_MIN) {
		encaps_data = rfc1042_header;
		encaps_len = sizeof(rfc1042_header);
		skip_header_bytes -= 2;
	} else {
		encaps_data = NULL;
		encaps_len = 0;
	}

	nh_pos = skb_network_header(skb) - skb->data;
	h_pos = skb_transport_header(skb) - skb->data;

	skb_pull(skb, skip_header_bytes);
	nh_pos -= skip_header_bytes;
	h_pos -= skip_header_bytes;

	head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);

	/*
	 * So we need to modify the skb header and hence need a copy of
	 * that. The head_need variable above doesn't, so far, include
	 * the needed header space that we don't need right away. If we
	 * can, then we don't reallocate right now but only after the
	 * frame arrives at the master device (if it does...)
	 *
	 * If we cannot, however, then we will reallocate to include all
	 * the ever needed space. Also, if we need to reallocate it anyway,
	 * make it big enough for everything we may ever need.
	 */

	if (head_need > 0 || skb_cloned(skb)) {
		head_need += sdata->encrypt_headroom;
		head_need += local->tx_headroom;
		head_need = max_t(int, 0, head_need);
		if (ieee80211_skb_resize(sdata, skb, head_need, true)) {
			ieee80211_free_txskb(&local->hw, skb);
			skb = NULL;
			return ERR_PTR(-ENOMEM);
		}
	}

	if (encaps_data) {
		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
		nh_pos += encaps_len;
		h_pos += encaps_len;
	}

#ifdef CPTCFG_MAC80211_MESH
	if (meshhdrlen > 0) {
		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
		nh_pos += meshhdrlen;
		h_pos += meshhdrlen;
	}
#endif

	if (ieee80211_is_data_qos(fc)) {
		__le16 *qos_control;

		qos_control = (__le16 *) skb_push(skb, 2);
		memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2);
		/*
		 * Maybe we could actually set some fields here, for now just
		 * initialise to zero to indicate no special operation.
		 */
		*qos_control = 0;
	} else
		memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);

	nh_pos += hdrlen;
	h_pos += hdrlen;

	/* Update skb pointers to various headers since this modified frame
	 * is going to go through Linux networking code that may potentially
	 * need things like pointer to IP header. */
	skb_set_mac_header(skb, 0);
	skb_set_network_header(skb, nh_pos);
	skb_set_transport_header(skb, h_pos);

	info = IEEE80211_SKB_CB(skb);
	memset(info, 0, sizeof(*info));

	info->flags = info_flags;
	info->ack_frame_id = info_id;
	info->band = band;

	return skb;
 free:
	kfree_skb(skb);
	return ERR_PTR(ret);
}

/*
 * fast-xmit overview
 *
 * The core idea of this fast-xmit is to remove per-packet checks by checking
 * them out of band. ieee80211_check_fast_xmit() implements the out-of-band
 * checks that are needed to get the sta->fast_tx pointer assigned, after which
 * much less work can be done per packet. For example, fragmentation must be
 * disabled or the fast_tx pointer will not be set. All the conditions are seen
 * in the code here.
 *
 * Once assigned, the fast_tx data structure also caches the per-packet 802.11
 * header and other data to aid packet processing in ieee80211_xmit_fast().
 *
 * The most difficult part of this is that when any of these assumptions
 * change, an external trigger (i.e. a call to ieee80211_clear_fast_xmit(),
 * ieee80211_check_fast_xmit() or friends) is required to reset the data,
 * since the per-packet code no longer checks the conditions. This is reflected
 * by the calls to these functions throughout the rest of the code, and must be
 * maintained if any of the TX path checks change.
 */

void ieee80211_check_fast_xmit(struct sta_info *sta)
{
	struct ieee80211_fast_tx build = {}, *fast_tx = NULL, *old;
	struct ieee80211_local *local = sta->local;
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct ieee80211_hdr *hdr = (void *)build.hdr;
	struct ieee80211_chanctx_conf *chanctx_conf;
	__le16 fc;

	if (!(local->hw.flags & IEEE80211_HW_SUPPORT_FAST_XMIT))
		return;

	/* Locking here protects both the pointer itself, and against concurrent
	 * invocations winning data access races to, e.g., the key pointer that
	 * is used.
	 * Without it, the invocation of this function right after the key
	 * pointer changes wouldn't be sufficient, as another CPU could access
	 * the pointer, then stall, and then do the cache update after the CPU
	 * that invalidated the key.
	 * With the locking, such scenarios cannot happen as the check for the
	 * key and the fast-tx assignment are done atomically, so the CPU that
	 * modifies the key will either wait or other one will see the key
	 * cleared/changed already.
	 */
	spin_lock_bh(&sta->lock);
	if (local->hw.flags & IEEE80211_HW_SUPPORTS_PS &&
	    !(local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS) &&
	    sdata->vif.type == NL80211_IFTYPE_STATION)
		goto out;

	if (!test_sta_flag(sta, WLAN_STA_AUTHORIZED))
		goto out;

	if (test_sta_flag(sta, WLAN_STA_PS_STA) ||
	    test_sta_flag(sta, WLAN_STA_PS_DRIVER) ||
	    test_sta_flag(sta, WLAN_STA_PS_DELIVER))
		goto out;

	if (sdata->noack_map)
		goto out;

	/* fast-xmit doesn't handle fragmentation at all */
	if (local->hw.wiphy->frag_threshold != (u32)-1 &&
	    !local->ops->set_frag_threshold)
		goto out;

	rcu_read_lock();
	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
	if (!chanctx_conf) {
		rcu_read_unlock();
		goto out;
	}
	build.band = chanctx_conf->def.chan->band;
	rcu_read_unlock();

	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);

	switch (sdata->vif.type) {
	case NL80211_IFTYPE_ADHOC:
		/* DA SA BSSID */
		build.da_offs = offsetof(struct ieee80211_hdr, addr1);
		build.sa_offs = offsetof(struct ieee80211_hdr, addr2);
		memcpy(hdr->addr3, sdata->u.ibss.bssid, ETH_ALEN);
		build.hdr_len = 24;
		break;
	case NL80211_IFTYPE_STATION:
		if (test_sta_flag(sta, WLAN_STA_TDLS_PEER)) {
			/* DA SA BSSID */
			build.da_offs = offsetof(struct ieee80211_hdr, addr1);
			build.sa_offs = offsetof(struct ieee80211_hdr, addr2);
			memcpy(hdr->addr3, sdata->u.mgd.bssid, ETH_ALEN);
			build.hdr_len = 24;
			break;
		}

		if (sdata->u.mgd.use_4addr) {
			/* non-regular ethertype cannot use the fastpath */
			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
					  IEEE80211_FCTL_TODS);
			/* RA TA DA SA */
			memcpy(hdr->addr1, sdata->u.mgd.bssid, ETH_ALEN);
			memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
			build.da_offs = offsetof(struct ieee80211_hdr, addr3);
			build.sa_offs = offsetof(struct ieee80211_hdr, addr4);
			build.hdr_len = 30;
			break;
		}
		fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
		/* BSSID SA DA */
		memcpy(hdr->addr1, sdata->u.mgd.bssid, ETH_ALEN);
		build.da_offs = offsetof(struct ieee80211_hdr, addr3);
		build.sa_offs = offsetof(struct ieee80211_hdr, addr2);
		build.hdr_len = 24;
		break;
	case NL80211_IFTYPE_AP_VLAN:
		if (sdata->wdev.use_4addr) {
			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
					  IEEE80211_FCTL_TODS);
			/* RA TA DA SA */
			memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN);
			memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
			build.da_offs = offsetof(struct ieee80211_hdr, addr3);
			build.sa_offs = offsetof(struct ieee80211_hdr, addr4);
			build.hdr_len = 30;
			break;
		}
		/* fall through */
	case NL80211_IFTYPE_AP:
		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
		/* DA BSSID SA */
		build.da_offs = offsetof(struct ieee80211_hdr, addr1);
		memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
		build.sa_offs = offsetof(struct ieee80211_hdr, addr3);
		build.hdr_len = 24;
		break;
	default:
		/* not handled on fast-xmit */
		goto out;
	}

	if (sta->sta.wme) {
		build.hdr_len += 2;
		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
	}

	/* We store the key here so there's no point in using rcu_dereference()
	 * but that's fine because the code that changes the pointers will call
	 * this function after doing so. For a single CPU that would be enough,
	 * for multiple see the comment above.
	 */
	build.key = rcu_access_pointer(sta->ptk[sta->ptk_idx]);
	if (!build.key)
		build.key = rcu_access_pointer(sdata->default_unicast_key);
	if (build.key) {
		bool gen_iv, iv_spc, mmic;

		gen_iv = build.key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV;
		iv_spc = build.key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE;
		mmic = build.key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC;

		/* don't handle software crypto */
		if (!(build.key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
			goto out;

		switch (build.key->conf.cipher) {
		case WLAN_CIPHER_SUITE_CCMP:
		case WLAN_CIPHER_SUITE_CCMP_256:
			/* add fixed key ID */
			if (gen_iv) {
				(build.hdr + build.hdr_len)[3] =
					0x20 | (build.key->conf.keyidx << 6);
				build.pn_offs = build.hdr_len;
			}
			if (gen_iv || iv_spc)
				build.hdr_len += IEEE80211_CCMP_HDR_LEN;
			break;
		case WLAN_CIPHER_SUITE_GCMP:
		case WLAN_CIPHER_SUITE_GCMP_256:
			/* add fixed key ID */
			if (gen_iv) {
				(build.hdr + build.hdr_len)[3] =
					0x20 | (build.key->conf.keyidx << 6);
				build.pn_offs = build.hdr_len;
			}
			if (gen_iv || iv_spc)
				build.hdr_len += IEEE80211_GCMP_HDR_LEN;
			break;
		case WLAN_CIPHER_SUITE_TKIP:
			/* cannot handle MMIC or IV generation in xmit-fast */
			if (mmic || gen_iv)
				goto out;
			if (iv_spc)
				build.hdr_len += IEEE80211_TKIP_IV_LEN;
			break;
		case WLAN_CIPHER_SUITE_WEP40:
		case WLAN_CIPHER_SUITE_WEP104:
			/* cannot handle IV generation in fast-xmit */
			if (gen_iv)
				goto out;
			if (iv_spc)
				build.hdr_len += IEEE80211_WEP_IV_LEN;
			break;
		case WLAN_CIPHER_SUITE_AES_CMAC:
		case WLAN_CIPHER_SUITE_BIP_CMAC_256:
		case WLAN_CIPHER_SUITE_BIP_GMAC_128:
		case WLAN_CIPHER_SUITE_BIP_GMAC_256:
			WARN(1,
			     "management cipher suite 0x%x enabled for data\n",
			     build.key->conf.cipher);
			goto out;
		default:
			/* we don't know how to generate IVs for this at all */
			if (WARN_ON(gen_iv))
				goto out;
			/* pure hardware keys are OK, of course */
			if (!(build.key->flags & KEY_FLAG_CIPHER_SCHEME))
				break;
			/* cipher scheme might require space allocation */
			if (iv_spc &&
			    build.key->conf.iv_len > IEEE80211_FAST_XMIT_MAX_IV)
				goto out;
			if (iv_spc)
				build.hdr_len += build.key->conf.iv_len;
		}

		fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
	}

	hdr->frame_control = fc;

	memcpy(build.hdr + build.hdr_len,
	       rfc1042_header,  sizeof(rfc1042_header));
	build.hdr_len += sizeof(rfc1042_header);

	fast_tx = kmemdup(&build, sizeof(build), GFP_ATOMIC);
	/* if the kmemdup fails, continue w/o fast_tx */
	if (!fast_tx)
		goto out;

 out:
	/* we might have raced against another call to this function */
	old = rcu_dereference_protected(sta->fast_tx,
					lockdep_is_held(&sta->lock));
	rcu_assign_pointer(sta->fast_tx, fast_tx);
	if (old)
		kfree_rcu(old, rcu_head);
	spin_unlock_bh(&sta->lock);
}

void ieee80211_check_fast_xmit_all(struct ieee80211_local *local)
{
	struct sta_info *sta;

	rcu_read_lock();
	list_for_each_entry_rcu(sta, &local->sta_list, list)
		ieee80211_check_fast_xmit(sta);
	rcu_read_unlock();
}

void ieee80211_check_fast_xmit_iface(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;

	rcu_read_lock();

	list_for_each_entry_rcu(sta, &local->sta_list, list) {
		if (sdata != sta->sdata &&
		    (!sta->sdata->bss || sta->sdata->bss != sdata->bss))
			continue;
		ieee80211_check_fast_xmit(sta);
	}

	rcu_read_unlock();
}

void ieee80211_clear_fast_xmit(struct sta_info *sta)
{
	struct ieee80211_fast_tx *fast_tx;

	spin_lock_bh(&sta->lock);
	fast_tx = rcu_dereference_protected(sta->fast_tx,
					    lockdep_is_held(&sta->lock));
	RCU_INIT_POINTER(sta->fast_tx, NULL);
	spin_unlock_bh(&sta->lock);

	if (fast_tx)
		kfree_rcu(fast_tx, rcu_head);
}

static bool ieee80211_xmit_fast(struct ieee80211_sub_if_data *sdata,
				struct net_device *dev, struct sta_info *sta,
				struct ieee80211_fast_tx *fast_tx,
				struct sk_buff *skb)
{
	struct ieee80211_local *local = sdata->local;
	u16 ethertype = (skb->data[12] << 8) | skb->data[13];
	int extra_head = fast_tx->hdr_len - (ETH_HLEN - 2);
	int hw_headroom = sdata->local->hw.extra_tx_headroom;
	struct ethhdr eth;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ieee80211_hdr *hdr = (void *)fast_tx->hdr;
	struct ieee80211_tx_data tx;
	ieee80211_tx_result r;
	struct tid_ampdu_tx *tid_tx = NULL;
	u8 tid = IEEE80211_NUM_TIDS;

	/* control port protocol needs a lot of special handling */
	if (cpu_to_be16(ethertype) == sdata->control_port_protocol)
		return false;

	/* only RFC 1042 SNAP */
	if (ethertype < ETH_P_802_3_MIN)
		return false;

	/* don't handle TX status request here either */
	if (skb->sk && skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS)
		return false;

	if (hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) {
		tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
		tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
		if (tid_tx &&
		    !test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state))
			return false;
	}

	/* after this point (skb is modified) we cannot return false */

	if (skb_shared(skb)) {
		struct sk_buff *tmp_skb = skb;

		skb = skb_clone(skb, GFP_ATOMIC);
		kfree_skb(tmp_skb);

		if (!skb)
			return true;
	}

	ieee80211_tx_stats(dev, skb->len + extra_head);

	/* will not be crypto-handled beyond what we do here, so use false
	 * as the may-encrypt argument for the resize to not account for
	 * more room than we already have in 'extra_head'
	 */
	if (unlikely(ieee80211_skb_resize(sdata, skb,
					  max_t(int, extra_head + hw_headroom -
						     skb_headroom(skb), 0),
					  false))) {
		kfree_skb(skb);
		return true;
	}

	memcpy(&eth, skb->data, ETH_HLEN - 2);
	hdr = (void *)skb_push(skb, extra_head);
	memcpy(skb->data, fast_tx->hdr, fast_tx->hdr_len);
	memcpy(skb->data + fast_tx->da_offs, eth.h_dest, ETH_ALEN);
	memcpy(skb->data + fast_tx->sa_offs, eth.h_source, ETH_ALEN);

	memset(info, 0, sizeof(*info));
	info->band = fast_tx->band;
	info->control.vif = &sdata->vif;
	info->flags = IEEE80211_TX_CTL_FIRST_FRAGMENT |
		      IEEE80211_TX_CTL_DONTFRAG |
		      (tid_tx ? IEEE80211_TX_CTL_AMPDU : 0);

	if (hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) {
		*ieee80211_get_qos_ctl(hdr) = tid;
		hdr->seq_ctrl = ieee80211_tx_next_seq(sta, tid);
	} else {
		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
		hdr->seq_ctrl = cpu_to_le16(sdata->sequence_number);
		sdata->sequence_number += 0x10;
	}

	sta->tx_msdu[tid]++;

	info->hw_queue = sdata->vif.hw_queue[skb_get_queue_mapping(skb)];

	__skb_queue_head_init(&tx.skbs);

	tx.flags = IEEE80211_TX_UNICAST;
	tx.local = local;
	tx.sdata = sdata;
	tx.sta = sta;
	tx.key = fast_tx->key;

	if (fast_tx->key)
		info->control.hw_key = &fast_tx->key->conf;

	if (!(local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)) {
		tx.skb = skb;
		r = ieee80211_tx_h_rate_ctrl(&tx);
		skb = tx.skb;
		tx.skb = NULL;

		if (r != TX_CONTINUE) {
			if (r != TX_QUEUED)
				kfree_skb(skb);
			return true;
		}
	}

	/* statistics normally done by ieee80211_tx_h_stats (but that
	 * has to consider fragmentation, so is more complex)
	 */
	sta->tx_bytes[skb_get_queue_mapping(skb)] += skb->len;
	sta->tx_packets[skb_get_queue_mapping(skb)]++;

	if (fast_tx->pn_offs) {
		u64 pn;
		u8 *crypto_hdr = skb->data + fast_tx->pn_offs;

		switch (fast_tx->key->conf.cipher) {
		case WLAN_CIPHER_SUITE_CCMP:
		case WLAN_CIPHER_SUITE_CCMP_256:
			pn = atomic64_inc_return(&fast_tx->key->u.ccmp.tx_pn);
			crypto_hdr[0] = pn;
			crypto_hdr[1] = pn >> 8;
			crypto_hdr[4] = pn >> 16;
			crypto_hdr[5] = pn >> 24;
			crypto_hdr[6] = pn >> 32;
			crypto_hdr[7] = pn >> 40;
			break;
		case WLAN_CIPHER_SUITE_GCMP:
		case WLAN_CIPHER_SUITE_GCMP_256:
			pn = atomic64_inc_return(&fast_tx->key->u.gcmp.tx_pn);
			crypto_hdr[0] = pn;
			crypto_hdr[1] = pn >> 8;
			crypto_hdr[4] = pn >> 16;
			crypto_hdr[5] = pn >> 24;
			crypto_hdr[6] = pn >> 32;
			crypto_hdr[7] = pn >> 40;
			break;
		}
	}

	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
		sdata = container_of(sdata->bss,
				     struct ieee80211_sub_if_data, u.ap);

	__skb_queue_tail(&tx.skbs, skb);
	ieee80211_tx_frags(local, &sdata->vif, &sta->sta, &tx.skbs, false);
	return true;
}

void __ieee80211_subif_start_xmit(struct sk_buff *skb,
				  struct net_device *dev,
				  u32 info_flags)
{
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	struct sta_info *sta;
	struct sk_buff *next;

	if (unlikely(skb->len < ETH_HLEN)) {
		kfree_skb(skb);
		return;
	}

	rcu_read_lock();

	if (ieee80211_lookup_ra_sta(sdata, skb, &sta))
		goto out_free;

	if (!IS_ERR_OR_NULL(sta)) {
		struct ieee80211_fast_tx *fast_tx;

		fast_tx = rcu_dereference(sta->fast_tx);

		if (fast_tx &&
		    ieee80211_xmit_fast(sdata, dev, sta, fast_tx, skb))
			goto out;
	}

	if (skb_is_gso(skb)) {
		struct sk_buff *segs;

		segs = skb_gso_segment(skb, 0);
		if (IS_ERR(segs)) {
			goto out_free;
		} else if (segs) {
			consume_skb(skb);
			skb = segs;
		}
	} else {
		/* we cannot process non-linear frames on this path */
		if (skb_linearize(skb)) {
			kfree_skb(skb);
			goto out;
		}

		/* the frame could be fragmented, software-encrypted, and other
		 * things so we cannot really handle checksum offload with it -
		 * fix it up in software before we handle anything else.
		 */
		if (skb->ip_summed == CHECKSUM_PARTIAL) {
			if (skb->encapsulation)
				skb_set_inner_transport_header(skb,
							       skb_checksum_start_offset(skb));
			else
				skb_set_transport_header(skb,
							 skb_checksum_start_offset(skb));
			if (skb_checksum_help(skb))
				goto out_free;
		}
	}

	next = skb;
	while (next) {
		skb = next;
		next = skb->next;

		skb->prev = NULL;
		skb->next = NULL;

		skb = ieee80211_build_hdr(sdata, skb, info_flags, sta);
		if (IS_ERR(skb))
			goto out;

		ieee80211_tx_stats(dev, skb->len);

		ieee80211_xmit(sdata, sta, skb);
	}
	goto out;
 out_free:
	kfree_skb(skb);
 out:
	rcu_read_unlock();
}

/**
 * ieee80211_subif_start_xmit - netif start_xmit function for 802.3 vifs
 * @skb: packet to be sent
 * @dev: incoming interface
 *
 * On failure skb will be freed.
 */
netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
				       struct net_device *dev)
{
	__ieee80211_subif_start_xmit(skb, dev, 0);
	return NETDEV_TX_OK;
}

struct sk_buff *
ieee80211_build_data_template(struct ieee80211_sub_if_data *sdata,
			      struct sk_buff *skb, u32 info_flags)
{
	struct ieee80211_hdr *hdr;
	struct ieee80211_tx_data tx = {
		.local = sdata->local,
		.sdata = sdata,
	};
	struct sta_info *sta;

	rcu_read_lock();

	if (ieee80211_lookup_ra_sta(sdata, skb, &sta)) {
		kfree_skb(skb);
		skb = ERR_PTR(-EINVAL);
		goto out;
	}

	skb = ieee80211_build_hdr(sdata, skb, info_flags, sta);
	if (IS_ERR(skb))
		goto out;

	hdr = (void *)skb->data;
	tx.sta = sta_info_get(sdata, hdr->addr1);
	tx.skb = skb;

	if (ieee80211_tx_h_select_key(&tx) != TX_CONTINUE) {
		rcu_read_unlock();
		kfree_skb(skb);
		return ERR_PTR(-EINVAL);
	}

out:
	rcu_read_unlock();
	return skb;
}

/*
 * ieee80211_clear_tx_pending may not be called in a context where
 * it is possible that it packets could come in again.
 */
void ieee80211_clear_tx_pending(struct ieee80211_local *local)
{
	struct sk_buff *skb;
	int i;

	for (i = 0; i < local->hw.queues; i++) {
		while ((skb = skb_dequeue(&local->pending[i])) != NULL)
			ieee80211_free_txskb(&local->hw, skb);
	}
}

/*
 * Returns false if the frame couldn't be transmitted but was queued instead,
 * which in this case means re-queued -- take as an indication to stop sending
 * more pending frames.
 */
static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
				     struct sk_buff *skb)
{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ieee80211_sub_if_data *sdata;
	struct sta_info *sta;
	struct ieee80211_hdr *hdr;
	bool result;
	struct ieee80211_chanctx_conf *chanctx_conf;

	sdata = vif_to_sdata(info->control.vif);

	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
		if (unlikely(!chanctx_conf)) {
			dev_kfree_skb(skb);
			return true;
		}
		info->band = chanctx_conf->def.chan->band;
		result = ieee80211_tx(sdata, NULL, skb, true);
	} else {
		struct sk_buff_head skbs;

		__skb_queue_head_init(&skbs);
		__skb_queue_tail(&skbs, skb);

		hdr = (struct ieee80211_hdr *)skb->data;
		sta = sta_info_get(sdata, hdr->addr1);

		result = __ieee80211_tx(local, &skbs, skb->len, sta, true);
	}

	return result;
}

/*
 * Transmit all pending packets. Called from tasklet.
 */
void ieee80211_tx_pending(unsigned long data)
{
	struct ieee80211_local *local = (struct ieee80211_local *)data;
	unsigned long flags;
	int i;
	bool txok;

	rcu_read_lock();

	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
	for (i = 0; i < local->hw.queues; i++) {
		/*
		 * If queue is stopped by something other than due to pending
		 * frames, or we have no pending frames, proceed to next queue.
		 */
		if (local->queue_stop_reasons[i] ||
		    skb_queue_empty(&local->pending[i]))
			continue;

		while (!skb_queue_empty(&local->pending[i])) {
			struct sk_buff *skb = __skb_dequeue(&local->pending[i]);
			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);

			if (WARN_ON(!info->control.vif)) {
				ieee80211_free_txskb(&local->hw, skb);
				continue;
			}

			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
						flags);

			txok = ieee80211_tx_pending_skb(local, skb);
			spin_lock_irqsave(&local->queue_stop_reason_lock,
					  flags);
			if (!txok)
				break;
		}

		if (skb_queue_empty(&local->pending[i]))
			ieee80211_propagate_queue_wake(local, i);
	}
	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);

	rcu_read_unlock();
}

/* functions for drivers to get certain frames */

static void __ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
				       struct ps_data *ps, struct sk_buff *skb,
				       bool is_template)
{
	u8 *pos, *tim;
	int aid0 = 0;
	int i, have_bits = 0, n1, n2;

	/* Generate bitmap for TIM only if there are any STAs in power save
	 * mode. */
	if (atomic_read(&ps->num_sta_ps) > 0)
		/* in the hope that this is faster than
		 * checking byte-for-byte */
		have_bits = !bitmap_empty((unsigned long *)ps->tim,
					  IEEE80211_MAX_AID+1);
	if (!is_template) {
		if (ps->dtim_count == 0)
			ps->dtim_count = sdata->vif.bss_conf.dtim_period - 1;
		else
			ps->dtim_count--;
	}

	tim = pos = (u8 *) skb_put(skb, 6);
	*pos++ = WLAN_EID_TIM;
	*pos++ = 4;
	*pos++ = ps->dtim_count;
	*pos++ = sdata->vif.bss_conf.dtim_period;

	if (ps->dtim_count == 0 && !skb_queue_empty(&ps->bc_buf))
		aid0 = 1;

	ps->dtim_bc_mc = aid0 == 1;

	if (have_bits) {
		/* Find largest even number N1 so that bits numbered 1 through
		 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
		 * (N2 + 1) x 8 through 2007 are 0. */
		n1 = 0;
		for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
			if (ps->tim[i]) {
				n1 = i & 0xfe;
				break;
			}
		}
		n2 = n1;
		for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
			if (ps->tim[i]) {
				n2 = i;
				break;
			}
		}

		/* Bitmap control */
		*pos++ = n1 | aid0;
		/* Part Virt Bitmap */
		skb_put(skb, n2 - n1);
		memcpy(pos, ps->tim + n1, n2 - n1 + 1);

		tim[1] = n2 - n1 + 4;
	} else {
		*pos++ = aid0; /* Bitmap control */
		*pos++ = 0; /* Part Virt Bitmap */
	}
}

static int ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
				    struct ps_data *ps, struct sk_buff *skb,
				    bool is_template)
{
	struct ieee80211_local *local = sdata->local;

	/*
	 * Not very nice, but we want to allow the driver to call
	 * ieee80211_beacon_get() as a response to the set_tim()
	 * callback. That, however, is already invoked under the
	 * sta_lock to guarantee consistent and race-free update
	 * of the tim bitmap in mac80211 and the driver.
	 */
	if (local->tim_in_locked_section) {
		__ieee80211_beacon_add_tim(sdata, ps, skb, is_template);
	} else {
		spin_lock_bh(&local->tim_lock);
		__ieee80211_beacon_add_tim(sdata, ps, skb, is_template);
		spin_unlock_bh(&local->tim_lock);
	}

	return 0;
}

static void ieee80211_set_csa(struct ieee80211_sub_if_data *sdata,
			      struct beacon_data *beacon)
{
	struct probe_resp *resp;
	u8 *beacon_data;
	size_t beacon_data_len;
	int i;
	u8 count = beacon->csa_current_counter;

	switch (sdata->vif.type) {
	case NL80211_IFTYPE_AP:
		beacon_data = beacon->tail;
		beacon_data_len = beacon->tail_len;
		break;
	case NL80211_IFTYPE_ADHOC:
		beacon_data = beacon->head;
		beacon_data_len = beacon->head_len;
		break;
	case NL80211_IFTYPE_MESH_POINT:
		beacon_data = beacon->head;
		beacon_data_len = beacon->head_len;
		break;
	default:
		return;
	}

	rcu_read_lock();
	for (i = 0; i < IEEE80211_MAX_CSA_COUNTERS_NUM; ++i) {
		resp = rcu_dereference(sdata->u.ap.probe_resp);

		if (beacon->csa_counter_offsets[i]) {
			if (WARN_ON_ONCE(beacon->csa_counter_offsets[i] >=
					 beacon_data_len)) {
				rcu_read_unlock();
				return;
			}

			beacon_data[beacon->csa_counter_offsets[i]] = count;
		}

		if (sdata->vif.type == NL80211_IFTYPE_AP && resp)
			resp->data[resp->csa_counter_offsets[i]] = count;
	}
	rcu_read_unlock();
}

u8 ieee80211_csa_update_counter(struct ieee80211_vif *vif)
{
	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
	struct beacon_data *beacon = NULL;
	u8 count = 0;

	rcu_read_lock();

	if (sdata->vif.type == NL80211_IFTYPE_AP)
		beacon = rcu_dereference(sdata->u.ap.beacon);
	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
		beacon = rcu_dereference(sdata->u.ibss.presp);
	else if (ieee80211_vif_is_mesh(&sdata->vif))
		beacon = rcu_dereference(sdata->u.mesh.beacon);

	if (!beacon)
		goto unlock;

	beacon->csa_current_counter--;

	/* the counter should never reach 0 */
	WARN_ON_ONCE(!beacon->csa_current_counter);
	count = beacon->csa_current_counter;

unlock:
	rcu_read_unlock();
	return count;
}
EXPORT_SYMBOL(ieee80211_csa_update_counter);

bool ieee80211_csa_is_complete(struct ieee80211_vif *vif)
{
	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
	struct beacon_data *beacon = NULL;
	u8 *beacon_data;
	size_t beacon_data_len;
	int ret = false;

	if (!ieee80211_sdata_running(sdata))
		return false;

	rcu_read_lock();
	if (vif->type == NL80211_IFTYPE_AP) {
		struct ieee80211_if_ap *ap = &sdata->u.ap;

		beacon = rcu_dereference(ap->beacon);
		if (WARN_ON(!beacon || !beacon->tail))
			goto out;
		beacon_data = beacon->tail;
		beacon_data_len = beacon->tail_len;
	} else if (vif->type == NL80211_IFTYPE_ADHOC) {
		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;

		beacon = rcu_dereference(ifibss->presp);
		if (!beacon)
			goto out;

		beacon_data = beacon->head;
		beacon_data_len = beacon->head_len;
	} else if (vif->type == NL80211_IFTYPE_MESH_POINT) {
		struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

		beacon = rcu_dereference(ifmsh->beacon);
		if (!beacon)
			goto out;

		beacon_data = beacon->head;
		beacon_data_len = beacon->head_len;
	} else {
		WARN_ON(1);
		goto out;
	}

	if (!beacon->csa_counter_offsets[0])
		goto out;

	if (WARN_ON_ONCE(beacon->csa_counter_offsets[0] > beacon_data_len))
		goto out;

	if (beacon_data[beacon->csa_counter_offsets[0]] == 1)
		ret = true;
 out:
	rcu_read_unlock();

	return ret;
}
EXPORT_SYMBOL(ieee80211_csa_is_complete);

static struct sk_buff *
__ieee80211_beacon_get(struct ieee80211_hw *hw,
		       struct ieee80211_vif *vif,
		       struct ieee80211_mutable_offsets *offs,
		       bool is_template)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct beacon_data *beacon = NULL;
	struct sk_buff *skb = NULL;
	struct ieee80211_tx_info *info;
	struct ieee80211_sub_if_data *sdata = NULL;
	enum ieee80211_band band;
	struct ieee80211_tx_rate_control txrc;
	struct ieee80211_chanctx_conf *chanctx_conf;
	int csa_off_base = 0;

	rcu_read_lock();

	sdata = vif_to_sdata(vif);
	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);

	if (!ieee80211_sdata_running(sdata) || !chanctx_conf)
		goto out;

	if (offs)
		memset(offs, 0, sizeof(*offs));

	if (sdata->vif.type == NL80211_IFTYPE_AP) {
		struct ieee80211_if_ap *ap = &sdata->u.ap;

		beacon = rcu_dereference(ap->beacon);
		if (beacon) {
			if (beacon->csa_counter_offsets[0]) {
				if (!is_template)
					ieee80211_csa_update_counter(vif);

				ieee80211_set_csa(sdata, beacon);
			}

			/*
			 * headroom, head length,
			 * tail length and maximum TIM length
			 */
			skb = dev_alloc_skb(local->tx_headroom +
					    beacon->head_len +
					    beacon->tail_len + 256 +
					    local->hw.extra_beacon_tailroom);
			if (!skb)
				goto out;

			skb_reserve(skb, local->tx_headroom);
			memcpy(skb_put(skb, beacon->head_len), beacon->head,
			       beacon->head_len);

			ieee80211_beacon_add_tim(sdata, &ap->ps, skb,
						 is_template);

			if (offs) {
				offs->tim_offset = beacon->head_len;
				offs->tim_length = skb->len - beacon->head_len;

				/* for AP the csa offsets are from tail */
				csa_off_base = skb->len;
			}

			if (beacon->tail)
				memcpy(skb_put(skb, beacon->tail_len),
				       beacon->tail, beacon->tail_len);
		} else
			goto out;
	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
		struct ieee80211_hdr *hdr;

		beacon = rcu_dereference(ifibss->presp);
		if (!beacon)
			goto out;

		if (beacon->csa_counter_offsets[0]) {
			if (!is_template)
				ieee80211_csa_update_counter(vif);

			ieee80211_set_csa(sdata, beacon);
		}

		skb = dev_alloc_skb(local->tx_headroom + beacon->head_len +
				    local->hw.extra_beacon_tailroom);
		if (!skb)
			goto out;
		skb_reserve(skb, local->tx_headroom);
		memcpy(skb_put(skb, beacon->head_len), beacon->head,
		       beacon->head_len);

		hdr = (struct ieee80211_hdr *) skb->data;
		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
						 IEEE80211_STYPE_BEACON);
	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
		struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

		beacon = rcu_dereference(ifmsh->beacon);
		if (!beacon)
			goto out;

		if (beacon->csa_counter_offsets[0]) {
			if (!is_template)
				/* TODO: For mesh csa_counter is in TU, so
				 * decrementing it by one isn't correct, but
				 * for now we leave it consistent with overall
				 * mac80211's behavior.
				 */
				ieee80211_csa_update_counter(vif);

			ieee80211_set_csa(sdata, beacon);
		}

		if (ifmsh->sync_ops)
			ifmsh->sync_ops->adjust_tbtt(sdata, beacon);

		skb = dev_alloc_skb(local->tx_headroom +
				    beacon->head_len +
				    256 + /* TIM IE */
				    beacon->tail_len +
				    local->hw.extra_beacon_tailroom);
		if (!skb)
			goto out;
		skb_reserve(skb, local->tx_headroom);
		memcpy(skb_put(skb, beacon->head_len), beacon->head,
		       beacon->head_len);
		ieee80211_beacon_add_tim(sdata, &ifmsh->ps, skb, is_template);

		if (offs) {
			offs->tim_offset = beacon->head_len;
			offs->tim_length = skb->len - beacon->head_len;
		}

		memcpy(skb_put(skb, beacon->tail_len), beacon->tail,
		       beacon->tail_len);
	} else {
		WARN_ON(1);
		goto out;
	}

	/* CSA offsets */
	if (offs && beacon) {
		int i;

		for (i = 0; i < IEEE80211_MAX_CSA_COUNTERS_NUM; i++) {
			u16 csa_off = beacon->csa_counter_offsets[i];

			if (!csa_off)
				continue;

			offs->csa_counter_offs[i] = csa_off_base + csa_off;
		}
	}

	band = chanctx_conf->def.chan->band;

	info = IEEE80211_SKB_CB(skb);

	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
	info->flags |= IEEE80211_TX_CTL_NO_ACK;
	info->band = band;

	memset(&txrc, 0, sizeof(txrc));
	txrc.hw = hw;
	txrc.sband = local->hw.wiphy->bands[band];
	txrc.bss_conf = &sdata->vif.bss_conf;
	txrc.skb = skb;
	txrc.reported_rate.idx = -1;
	txrc.rate_idx_mask = sdata->rc_rateidx_mask[band];
	if (txrc.rate_idx_mask == (1 << txrc.sband->n_bitrates) - 1)
		txrc.max_rate_idx = -1;
	else
		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
	txrc.bss = true;
	rate_control_get_rate(sdata, NULL, &txrc);

	info->control.vif = vif;

	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT |
			IEEE80211_TX_CTL_ASSIGN_SEQ |
			IEEE80211_TX_CTL_FIRST_FRAGMENT;
 out:
	rcu_read_unlock();
	return skb;

}

struct sk_buff *
ieee80211_beacon_get_template(struct ieee80211_hw *hw,
			      struct ieee80211_vif *vif,
			      struct ieee80211_mutable_offsets *offs)
{
	return __ieee80211_beacon_get(hw, vif, offs, true);
}
EXPORT_SYMBOL(ieee80211_beacon_get_template);

struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
					 struct ieee80211_vif *vif,
					 u16 *tim_offset, u16 *tim_length)
{
	struct ieee80211_mutable_offsets offs = {};
	struct sk_buff *bcn = __ieee80211_beacon_get(hw, vif, &offs, false);

	if (tim_offset)
		*tim_offset = offs.tim_offset;

	if (tim_length)
		*tim_length = offs.tim_length;

	return bcn;
}
EXPORT_SYMBOL(ieee80211_beacon_get_tim);

struct sk_buff *ieee80211_proberesp_get(struct ieee80211_hw *hw,
					struct ieee80211_vif *vif)
{
	struct ieee80211_if_ap *ap = NULL;
	struct sk_buff *skb = NULL;
	struct probe_resp *presp = NULL;
	struct ieee80211_hdr *hdr;
	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);

	if (sdata->vif.type != NL80211_IFTYPE_AP)
		return NULL;

	rcu_read_lock();

	ap = &sdata->u.ap;
	presp = rcu_dereference(ap->probe_resp);
	if (!presp)
		goto out;

	skb = dev_alloc_skb(presp->len);
	if (!skb)
		goto out;

	memcpy(skb_put(skb, presp->len), presp->data, presp->len);

	hdr = (struct ieee80211_hdr *) skb->data;
	memset(hdr->addr1, 0, sizeof(hdr->addr1));

out:
	rcu_read_unlock();
	return skb;
}
EXPORT_SYMBOL(ieee80211_proberesp_get);

struct sk_buff *ieee80211_pspoll_get(struct ieee80211_hw *hw,
				     struct ieee80211_vif *vif)
{
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_if_managed *ifmgd;
	struct ieee80211_pspoll *pspoll;
	struct ieee80211_local *local;
	struct sk_buff *skb;

	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
		return NULL;

	sdata = vif_to_sdata(vif);
	ifmgd = &sdata->u.mgd;
	local = sdata->local;

	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*pspoll));
	if (!skb)
		return NULL;

	skb_reserve(skb, local->hw.extra_tx_headroom);

	pspoll = (struct ieee80211_pspoll *) skb_put(skb, sizeof(*pspoll));
	memset(pspoll, 0, sizeof(*pspoll));
	pspoll->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
					    IEEE80211_STYPE_PSPOLL);
	pspoll->aid = cpu_to_le16(ifmgd->aid);

	/* aid in PS-Poll has its two MSBs each set to 1 */
	pspoll->aid |= cpu_to_le16(1 << 15 | 1 << 14);

	memcpy(pspoll->bssid, ifmgd->bssid, ETH_ALEN);
	memcpy(pspoll->ta, vif->addr, ETH_ALEN);

	return skb;
}
EXPORT_SYMBOL(ieee80211_pspoll_get);

struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
				       struct ieee80211_vif *vif)
{
	struct ieee80211_hdr_3addr *nullfunc;
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_if_managed *ifmgd;
	struct ieee80211_local *local;
	struct sk_buff *skb;

	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
		return NULL;

	sdata = vif_to_sdata(vif);
	ifmgd = &sdata->u.mgd;
	local = sdata->local;

	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*nullfunc));
	if (!skb)
		return NULL;

	skb_reserve(skb, local->hw.extra_tx_headroom);

	nullfunc = (struct ieee80211_hdr_3addr *) skb_put(skb,
							  sizeof(*nullfunc));
	memset(nullfunc, 0, sizeof(*nullfunc));
	nullfunc->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
					      IEEE80211_STYPE_NULLFUNC |
					      IEEE80211_FCTL_TODS);
	memcpy(nullfunc->addr1, ifmgd->bssid, ETH_ALEN);
	memcpy(nullfunc->addr2, vif->addr, ETH_ALEN);
	memcpy(nullfunc->addr3, ifmgd->bssid, ETH_ALEN);

	return skb;
}
EXPORT_SYMBOL(ieee80211_nullfunc_get);

struct sk_buff *ieee80211_probereq_get(struct ieee80211_hw *hw,
				       const u8 *src_addr,
				       const u8 *ssid, size_t ssid_len,
				       size_t tailroom)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_hdr_3addr *hdr;
	struct sk_buff *skb;
	size_t ie_ssid_len;
	u8 *pos;

	ie_ssid_len = 2 + ssid_len;

	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*hdr) +
			    ie_ssid_len + tailroom);
	if (!skb)
		return NULL;

	skb_reserve(skb, local->hw.extra_tx_headroom);

	hdr = (struct ieee80211_hdr_3addr *) skb_put(skb, sizeof(*hdr));
	memset(hdr, 0, sizeof(*hdr));
	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
					 IEEE80211_STYPE_PROBE_REQ);
	eth_broadcast_addr(hdr->addr1);
	memcpy(hdr->addr2, src_addr, ETH_ALEN);
	eth_broadcast_addr(hdr->addr3);

	pos = skb_put(skb, ie_ssid_len);
	*pos++ = WLAN_EID_SSID;
	*pos++ = ssid_len;
	if (ssid_len)
		memcpy(pos, ssid, ssid_len);
	pos += ssid_len;

	return skb;
}
EXPORT_SYMBOL(ieee80211_probereq_get);

void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
		       const void *frame, size_t frame_len,
		       const struct ieee80211_tx_info *frame_txctl,
		       struct ieee80211_rts *rts)
{
	const struct ieee80211_hdr *hdr = frame;

	rts->frame_control =
	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
					       frame_txctl);
	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
}
EXPORT_SYMBOL(ieee80211_rts_get);

void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
			     const void *frame, size_t frame_len,
			     const struct ieee80211_tx_info *frame_txctl,
			     struct ieee80211_cts *cts)
{
	const struct ieee80211_hdr *hdr = frame;

	cts->frame_control =
	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
	cts->duration = ieee80211_ctstoself_duration(hw, vif,
						     frame_len, frame_txctl);
	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
}
EXPORT_SYMBOL(ieee80211_ctstoself_get);

struct sk_buff *
ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
			  struct ieee80211_vif *vif)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct sk_buff *skb = NULL;
	struct ieee80211_tx_data tx;
	struct ieee80211_sub_if_data *sdata;
	struct ps_data *ps;
	struct ieee80211_tx_info *info;
	struct ieee80211_chanctx_conf *chanctx_conf;

	sdata = vif_to_sdata(vif);

	rcu_read_lock();
	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);

	if (!chanctx_conf)
		goto out;

	if (sdata->vif.type == NL80211_IFTYPE_AP) {
		struct beacon_data *beacon =
				rcu_dereference(sdata->u.ap.beacon);

		if (!beacon || !beacon->head)
			goto out;

		ps = &sdata->u.ap.ps;
	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
		ps = &sdata->u.mesh.ps;
	} else {
		goto out;
	}

	if (ps->dtim_count != 0 || !ps->dtim_bc_mc)
		goto out; /* send buffered bc/mc only after DTIM beacon */

	while (1) {
		skb = skb_dequeue(&ps->bc_buf);
		if (!skb)
			goto out;
		local->total_ps_buffered--;

		if (!skb_queue_empty(&ps->bc_buf) && skb->len >= 2) {
			struct ieee80211_hdr *hdr =
				(struct ieee80211_hdr *) skb->data;
			/* more buffered multicast/broadcast frames ==> set
			 * MoreData flag in IEEE 802.11 header to inform PS
			 * STAs */
			hdr->frame_control |=
				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
		}

		if (sdata->vif.type == NL80211_IFTYPE_AP)
			sdata = IEEE80211_DEV_TO_SUB_IF(skb->dev);
		if (!ieee80211_tx_prepare(sdata, &tx, NULL, skb))
			break;
		dev_kfree_skb_any(skb);
	}

	info = IEEE80211_SKB_CB(skb);

	tx.flags |= IEEE80211_TX_PS_BUFFERED;
	info->band = chanctx_conf->def.chan->band;

	if (invoke_tx_handlers(&tx))
		skb = NULL;
 out:
	rcu_read_unlock();

	return skb;
}
EXPORT_SYMBOL(ieee80211_get_buffered_bc);

int ieee80211_reserve_tid(struct ieee80211_sta *pubsta, u8 tid)
{
	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct ieee80211_local *local = sdata->local;
	int ret;
	u32 queues;

	lockdep_assert_held(&local->sta_mtx);

	/* only some cases are supported right now */
	switch (sdata->vif.type) {
	case NL80211_IFTYPE_STATION:
	case NL80211_IFTYPE_AP:
	case NL80211_IFTYPE_AP_VLAN:
		break;
	default:
		WARN_ON(1);
		return -EINVAL;
	}

	if (WARN_ON(tid >= IEEE80211_NUM_UPS))
		return -EINVAL;

	if (sta->reserved_tid == tid) {
		ret = 0;
		goto out;
	}

	if (sta->reserved_tid != IEEE80211_TID_UNRESERVED) {
		sdata_err(sdata, "TID reservation already active\n");
		ret = -EALREADY;
		goto out;
	}

	ieee80211_stop_vif_queues(sdata->local, sdata,
				  IEEE80211_QUEUE_STOP_REASON_RESERVE_TID);

	synchronize_net();

	/* Tear down BA sessions so we stop aggregating on this TID */
	if (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) {
		set_sta_flag(sta, WLAN_STA_BLOCK_BA);
		__ieee80211_stop_tx_ba_session(sta, tid,
					       AGG_STOP_LOCAL_REQUEST);
	}

	queues = BIT(sdata->vif.hw_queue[ieee802_1d_to_ac[tid]]);
	__ieee80211_flush_queues(local, sdata, queues, false);

	sta->reserved_tid = tid;

	ieee80211_wake_vif_queues(local, sdata,
				  IEEE80211_QUEUE_STOP_REASON_RESERVE_TID);

	if (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)
		clear_sta_flag(sta, WLAN_STA_BLOCK_BA);

	ret = 0;
 out:
	return ret;
}
EXPORT_SYMBOL(ieee80211_reserve_tid);

void ieee80211_unreserve_tid(struct ieee80211_sta *pubsta, u8 tid)
{
	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
	struct ieee80211_sub_if_data *sdata = sta->sdata;

	lockdep_assert_held(&sdata->local->sta_mtx);

	/* only some cases are supported right now */
	switch (sdata->vif.type) {
	case NL80211_IFTYPE_STATION:
	case NL80211_IFTYPE_AP:
	case NL80211_IFTYPE_AP_VLAN:
		break;
	default:
		WARN_ON(1);
		return;
	}

	if (tid != sta->reserved_tid) {
		sdata_err(sdata, "TID to unreserve (%d) isn't reserved\n", tid);
		return;
	}

	sta->reserved_tid = IEEE80211_TID_UNRESERVED;
}
EXPORT_SYMBOL(ieee80211_unreserve_tid);

void __ieee80211_tx_skb_tid_band(struct ieee80211_sub_if_data *sdata,
				 struct sk_buff *skb, int tid,
				 enum ieee80211_band band)
{
	int ac = ieee802_1d_to_ac[tid & 7];

	skb_set_mac_header(skb, 0);
	skb_set_network_header(skb, 0);
	skb_set_transport_header(skb, 0);

	skb_set_queue_mapping(skb, ac);
	skb->priority = tid;

	skb->dev = sdata->dev;

	/*
	 * The other path calling ieee80211_xmit is from the tasklet,
	 * and while we can handle concurrent transmissions locking
	 * requirements are that we do not come into tx with bhs on.
	 */
	local_bh_disable();
	IEEE80211_SKB_CB(skb)->band = band;
	ieee80211_xmit(sdata, NULL, skb);
	local_bh_enable();
}

                 reply	other threads:[~2015-05-05 13:13 UTC|newest]

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