Release 4.14 net/mac80211/rx.c

/*
 * 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
 * Copyright(c) 2015 - 2017 Intel Deutschland 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 <linux/bitops.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);
}

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static u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len,
			       enum nl80211_iftype type)
{
	__le16 fc = hdr->frame_control;

	if (ieee80211_is_data(fc)) {
		if (len < 24) /* drop incorrect hdr len (data) */
			return NULL;

		if (ieee80211_has_a4(fc))
			return NULL;
		if (ieee80211_has_tods(fc))
			return hdr->addr1;
		if (ieee80211_has_fromds(fc))
			return hdr->addr2;

		return hdr->addr3;
	}

	if (ieee80211_is_mgmt(fc)) {
		if (len < 24) /* drop incorrect hdr len (mgmt) */
			return NULL;
		return hdr->addr3;
	}

	if (ieee80211_is_ctl(fc)) {
		if (ieee80211_is_pspoll(fc))
			return hdr->addr1;

		if (ieee80211_is_back_req(fc)) {
			switch (type) {
			case NL80211_IFTYPE_STATION:
				return hdr->addr2;
			case NL80211_IFTYPE_AP:
			case NL80211_IFTYPE_AP_VLAN:
				return hdr->addr1;
			default:
				break; /* fall through to the return */
			}
		}
	}

	return NULL;
}

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/*
 * monitor mode reception
 *
 * This function cleans up the SKB, i.e. it removes all the stuff
 * only useful for monitoring.
 */


static void remove_monitor_info(struct sk_buff *skb,
				unsigned int present_fcs_len,
				unsigned int rtap_vendor_space)
{
	if (present_fcs_len)
		__pskb_trim(skb, skb->len - present_fcs_len);
	__pskb_pull(skb, rtap_vendor_space);
}

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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_ONLY_MONITOR))
		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;
}

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1
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5
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1
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1.75%
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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 (ieee80211_hw_check(&local->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->encoding == RX_ENC_HT) /* HT info */
		len += 3;

	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
		len = ALIGN(len, 4);
		len += 8;
	}

	if (status->encoding == RX_ENC_VHT) {
		len = ALIGN(len, 2);
		len += 12;
	}

	if (local->hw.radiotap_timestamp.units_pos >= 0) {
		len = ALIGN(len, 8);
		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;
}

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static void ieee80211_handle_mu_mimo_mon(struct ieee80211_sub_if_data *sdata,
					 struct sk_buff *skb,
					 int rtap_vendor_space)
{
	struct {
		struct ieee80211_hdr_3addr hdr;
		u8 category;
		u8 action_code;
	} __packed action;

	if (!sdata)
		return;

	BUILD_BUG_ON(sizeof(action) != IEEE80211_MIN_ACTION_SIZE + 1);

	if (skb->len < rtap_vendor_space + sizeof(action) +
		       VHT_MUMIMO_GROUPS_DATA_LEN)
		return;

	if (!is_valid_ether_addr(sdata->u.mntr.mu_follow_addr))
		return;

	skb_copy_bits(skb, rtap_vendor_space, &action, sizeof(action));

	if (!ieee80211_is_action(action.hdr.frame_control))
		return;

	if (action.category != WLAN_CATEGORY_VHT)
		return;

	if (action.action_code != WLAN_VHT_ACTION_GROUPID_MGMT)
		return;

	if (!ether_addr_equal(action.hdr.addr1, sdata->u.mntr.mu_follow_addr))
		return;

	skb = skb_copy(skb, GFP_ATOMIC);
	if (!skb)
		return;

	skb_queue_tail(&sdata->skb_queue, skb);
	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
}

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/*
 * 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 && ieee80211_hw_check(&local->hw, RX_INCLUDES_FCS)))
		mpdulen += FCS_LEN;

	rthdr = 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 && ieee80211_hw_check(&local->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->enc_flags & RX_ENC_FLAG_SHORTPRE)
		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
	pos++;

	/* IEEE80211_RADIOTAP_RATE */
	if (!rate || status->encoding != RX_ENC_LEGACY) {
		/*
                 * 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->bw == RATE_INFO_BW_10)
			shift = 1;
		else if (status->bw == RATE_INFO_BW_5)
			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->bw == RATE_INFO_BW_10)
		channel_flags |= IEEE80211_CHAN_HALF;
	else if (status->bw == RATE_INFO_BW_5)
		channel_flags |= IEEE80211_CHAN_QUARTER;

	if (status->band == NL80211_BAND_5GHZ)
		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ;
	else if (status->encoding != RX_ENC_LEGACY)
		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 (ieee80211_hw_check(&local->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->encoding == RX_ENC_HT) {
		unsigned int stbc;

		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
		*pos++ = local->hw.radiotap_mcs_details;
		*pos = 0;
		if (status->enc_flags & RX_ENC_FLAG_SHORT_GI)
			*pos |= IEEE80211_RADIOTAP_MCS_SGI;
		if (status->bw == RATE_INFO_BW_40)
			*pos |= IEEE80211_RADIOTAP_MCS_BW_40;
		if (status->enc_flags & RX_ENC_FLAG_HT_GF)
			*pos |= IEEE80211_RADIOTAP_MCS_FMT_GF;
		if (status->enc_flags & RX_ENC_FLAG_LDPC)
			*pos |= IEEE80211_RADIOTAP_MCS_FEC_LDPC;
		stbc = (status->enc_flags & RX_ENC_FLAG_STBC_MASK) >> RX_ENC_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_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->encoding == RX_ENC_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->enc_flags & RX_ENC_FLAG_SHORT_GI)
			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
		/* in VHT, STBC is binary */
		if (status->enc_flags & RX_ENC_FLAG_STBC_MASK)
			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_STBC;
		if (status->enc_flags & RX_ENC_FLAG_BF)
			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_BEAMFORMED;
		pos++;
		/* bandwidth */
		switch (status->bw) {
		case RATE_INFO_BW_80:
			*pos++ = 4;
			break;
		case RATE_INFO_BW_160:
			*pos++ = 11;
			break;
		case RATE_INFO_BW_40:
			*pos++ = 1;
			break;
		default:
			*pos++ = 0;
		}
		/* MCS/NSS */
		*pos = (status->rate_idx << 4) | status->nss;
		pos += 4;
		/* coding field */
		if (status->enc_flags & RX_ENC_FLAG_LDPC)
			*pos |= IEEE80211_RADIOTAP_CODING_LDPC_USER0;
		pos++;
		/* group ID */
		pos++;
		/* partial_aid */
		pos += 2;
	}

	if (local->hw.radiotap_timestamp.units_pos >= 0) {
		u16 accuracy = 0;
		u8 flags = IEEE80211_RADIOTAP_TIMESTAMP_FLAG_32BIT;

		rthdr->it_present |=
			cpu_to_le32(1 << IEEE80211_RADIOTAP_TIMESTAMP);

		/* ensure 8 byte alignment */
		while ((pos - (u8 *)rthdr) & 7)
			pos++;

		put_unaligned_le64(status->device_timestamp, pos);
		pos += sizeof(u64);

		if (local->hw.radiotap_timestamp.accuracy >= 0) {
			accuracy = local->hw.radiotap_timestamp.accuracy;
			flags |= IEEE80211_RADIOTAP_TIMESTAMP_FLAG_ACCURACY;
		}
		put_unaligned_le16(accuracy, pos);
		pos += sizeof(u16);

		*pos++ = local->hw.radiotap_timestamp.units_pos;
		*pos++ = flags;
	}

	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 */
	}
}

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7.69%
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static struct sk_buff *

ieee80211_make_monitor_skb(struct ieee80211_local *local,
			   struct sk_buff **origskb,
			   struct ieee80211_rate *rate,
			   int rtap_vendor_space, bool use_origskb)
{
	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(*origskb);
	int rt_hdrlen, needed_headroom;
	struct sk_buff *skb;

	/* 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 (use_origskb) {
		/* 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);

		if (!skb)
			return NULL;
	}

	/* 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);

	return skb;
}

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/*
 * 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;
	struct sk_buff *monskb = NULL;
	int present_fcs_len = 0;
	unsigned int rtap_vendor_space = 0;
	struct ieee80211_sub_if_data *monitor_sdata =
		rcu_dereference(local->monitor_sdata);
	bool only_monitor = false;

	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 (ieee80211_hw_check(&local->hw, RX_INCLUDES_FCS)) {
		if (unlikely(origskb->len <= FCS_LEN)) {
			/* driver bug */
			WARN_ON(1);
			dev_kfree_skb(origskb);
			return NULL;
		}
		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;
	}

	only_monitor = should_drop_frame(origskb, present_fcs_len,
					 rtap_vendor_space);

	if (!local->monitors || (status->flag & RX_FLAG_SKIP_MONITOR)) {
		if (only_monitor) {
			dev_kfree_skb(origskb);
			return NULL;
		}

		remove_monitor_info(origskb, present_fcs_len,
				    rtap_vendor_space);
		return origskb;
	}

	ieee80211_handle_mu_mimo_mon(monitor_sdata, origskb, rtap_vendor_space);

	list_for_each_entry_rcu(sdata, &local->mon_list, u.mntr.list) {
		bool last_monitor = list_is_last(&sdata->u.mntr.list,
						 &local->mon_list);

		if (!monskb)
			monskb = ieee80211_make_monitor_skb(local, &origskb,
							    rate,
							    rtap_vendor_space,
							    only_monitor &&
							    last_monitor);

		if (monskb) {
			struct sk_buff *skb;

			if (last_monitor) {
				skb = monskb;
				monskb = NULL;
			} else {
				skb = skb_clone(monskb, GFP_ATOMIC);
			}

			if (skb) {
				skb->dev = sdata->dev;
				ieee80211_rx_stats(skb->dev, skb->len);
				netif_receive_skb(skb);
			}
		}

		if (last_monitor)
			break;
	}

	/* this happens if last_monitor was erroneously false */
	dev_kfree_skb(monskb);

	/* ditto */
	if (!origskb)
		return NULL;

	remove_monitor_info(origskb, present_fcs_len, rtap_vendor_space);
	return origskb;
}

Contributors
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Johannes Berg
292
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Bruno Randolf
63
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Yi Zhu
20
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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);