rx.c 44.9 KB
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/*
 * 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>
 *
 * 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/kernel.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
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#include <linux/rcupdate.h>
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#include <net/mac80211.h>
#include <net/ieee80211_radiotap.h>

#include "ieee80211_i.h"
#include "ieee80211_led.h"
#include "wep.h"
#include "wpa.h"
#include "tkip.h"
#include "wme.h"

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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 struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
					   struct sk_buff *skb,
					   int rtap_len)
{
	skb_pull(skb, rtap_len);

	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
		if (likely(skb->len > FCS_LEN))
			skb_trim(skb, skb->len - FCS_LEN);
		else {
			/* driver bug */
			WARN_ON(1);
			dev_kfree_skb(skb);
			skb = NULL;
		}
	}

	return skb;
}

static inline int should_drop_frame(struct ieee80211_rx_status *status,
				    struct sk_buff *skb,
				    int present_fcs_len,
				    int radiotap_len)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;

	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
		return 1;
	if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
		return 1;
	if ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_FTYPE)) ==
			cpu_to_le16(IEEE80211_FTYPE_CTL))
		return 1;
	return 0;
}

/*
 * This function copies a received frame to all monitor interfaces and
 * returns a cleaned-up SKB that no longer includes the FCS nor the
 * radiotap header the driver might have added.
 */
static struct sk_buff *
ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
		     struct ieee80211_rx_status *status)
{
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_rate *rate;
	int needed_headroom = 0;
	struct ieee80211_rtap_hdr {
		struct ieee80211_radiotap_header hdr;
		u8 flags;
		u8 rate;
		__le16 chan_freq;
		__le16 chan_flags;
		u8 antsignal;
		u8 padding_for_rxflags;
		__le16 rx_flags;
	} __attribute__ ((packed)) *rthdr;
	struct sk_buff *skb, *skb2;
	struct net_device *prev_dev = NULL;
	int present_fcs_len = 0;
	int rtap_len = 0;

	/*
	 * First, we may need to make a copy of the skb because
	 *  (1) we need to modify it for radiotap (if not present), and
	 *  (2) the other RX handlers will modify the skb we got.
	 *
	 * We don't need to, of course, if we aren't going to return
	 * the SKB because it has a bad FCS/PLCP checksum.
	 */
	if (status->flag & RX_FLAG_RADIOTAP)
		rtap_len = ieee80211_get_radiotap_len(origskb->data);
	else
		needed_headroom = sizeof(*rthdr);

	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
		present_fcs_len = FCS_LEN;

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

		return remove_monitor_info(local, origskb, rtap_len);
	}

	if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
		/* only need to expand headroom if necessary */
		skb = origskb;
		origskb = NULL;

		/*
		 * This shouldn't trigger often because most devices have an
		 * RX header they pull before we get here, and that should
		 * be big enough for our radiotap information. We should
		 * probably export the length to drivers so that we can have
		 * them allocate enough headroom to start with.
		 */
		if (skb_headroom(skb) < needed_headroom &&
		    pskb_expand_head(skb, sizeof(*rthdr), 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_len);

		if (!skb)
			return origskb;
	}

	/* if necessary, prepend radiotap information */
	if (!(status->flag & RX_FLAG_RADIOTAP)) {
		rthdr = (void *) skb_push(skb, sizeof(*rthdr));
		memset(rthdr, 0, sizeof(*rthdr));
		rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
		rthdr->hdr.it_present =
			cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
				    (1 << IEEE80211_RADIOTAP_RATE) |
				    (1 << IEEE80211_RADIOTAP_CHANNEL) |
				    (1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL) |
				    (1 << IEEE80211_RADIOTAP_RX_FLAGS));
		rthdr->flags = local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS ?
			       IEEE80211_RADIOTAP_F_FCS : 0;

		/* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
		rthdr->rx_flags = 0;
		if (status->flag &
		    (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
			rthdr->rx_flags |=
				cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);

		rate = ieee80211_get_rate(local, status->phymode,
					  status->rate);
		if (rate)
			rthdr->rate = rate->rate / 5;

		rthdr->chan_freq = cpu_to_le16(status->freq);

		if (status->phymode == MODE_IEEE80211A)
			rthdr->chan_flags =
				cpu_to_le16(IEEE80211_CHAN_OFDM |
					    IEEE80211_CHAN_5GHZ);
		else
			rthdr->chan_flags =
				cpu_to_le16(IEEE80211_CHAN_DYN |
					    IEEE80211_CHAN_2GHZ);

		rthdr->antsignal = status->ssi;
	}

	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 (!netif_running(sdata->dev))
			continue;

		if (sdata->type != IEEE80211_IF_TYPE_MNTR)
			continue;

		if (prev_dev) {
			skb2 = skb_clone(skb, GFP_ATOMIC);
			if (skb2) {
				skb2->dev = prev_dev;
				netif_rx(skb2);
			}
		}

		prev_dev = sdata->dev;
		sdata->dev->stats.rx_packets++;
		sdata->dev->stats.rx_bytes += skb->len;
	}

	if (prev_dev) {
		skb->dev = prev_dev;
		netif_rx(skb);
	} else
		dev_kfree_skb(skb);

	return origskb;
}


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/* pre-rx handlers
 *
 * these don't have dev/sdata fields in the rx data
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 * The sta value should also not be used because it may
 * be NULL even though a STA (in IBSS mode) will be added.
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 */

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static ieee80211_txrx_result
ieee80211_rx_h_parse_qos(struct ieee80211_txrx_data *rx)
{
	u8 *data = rx->skb->data;
	int tid;

	/* does the frame have a qos control field? */
	if (WLAN_FC_IS_QOS_DATA(rx->fc)) {
		u8 *qc = data + ieee80211_get_hdrlen(rx->fc) - QOS_CONTROL_LEN;
		/* frame has qos control */
		tid = qc[0] & QOS_CONTROL_TID_MASK;
	} else {
		if (unlikely((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT)) {
			/* Separate TID for management frames */
			tid = NUM_RX_DATA_QUEUES - 1;
		} else {
			/* no qos control present */
			tid = 0; /* 802.1d - Best Effort */
		}
	}
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	I802_DEBUG_INC(rx->local->wme_rx_queue[tid]);
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	/* only a debug counter, sta might not be assigned properly yet */
	if (rx->sta)
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		I802_DEBUG_INC(rx->sta->wme_rx_queue[tid]);

	rx->u.rx.queue = tid;
	/* 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;

	return TXRX_CONTINUE;
}

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static ieee80211_txrx_result
ieee80211_rx_h_load_stats(struct ieee80211_txrx_data *rx)
{
	struct ieee80211_local *local = rx->local;
	struct sk_buff *skb = rx->skb;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	u32 load = 0, hdrtime;
	struct ieee80211_rate *rate;
	struct ieee80211_hw_mode *mode = local->hw.conf.mode;
	int i;

	/* Estimate total channel use caused by this frame */

	if (unlikely(mode->num_rates < 0))
		return TXRX_CONTINUE;

	rate = &mode->rates[0];
	for (i = 0; i < mode->num_rates; i++) {
		if (mode->rates[i].val == rx->u.rx.status->rate) {
			rate = &mode->rates[i];
			break;
		}
	}

	/* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
	 * 1 usec = 1/8 * (1080 / 10) = 13.5 */

	if (mode->mode == MODE_IEEE80211A ||
	    (mode->mode == MODE_IEEE80211G &&
	     rate->flags & IEEE80211_RATE_ERP))
		hdrtime = CHAN_UTIL_HDR_SHORT;
	else
		hdrtime = CHAN_UTIL_HDR_LONG;

	load = hdrtime;
	if (!is_multicast_ether_addr(hdr->addr1))
		load += hdrtime;

	load += skb->len * rate->rate_inv;

	/* Divide channel_use by 8 to avoid wrapping around the counter */
	load >>= CHAN_UTIL_SHIFT;
	local->channel_use_raw += load;
	rx->u.rx.load = load;

	return TXRX_CONTINUE;
}

ieee80211_rx_handler ieee80211_rx_pre_handlers[] =
{
	ieee80211_rx_h_parse_qos,
	ieee80211_rx_h_load_stats,
	NULL
};

/* rx handlers */

static ieee80211_txrx_result
ieee80211_rx_h_if_stats(struct ieee80211_txrx_data *rx)
{
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	if (rx->sta)
		rx->sta->channel_use_raw += rx->u.rx.load;
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	rx->sdata->channel_use_raw += rx->u.rx.load;
	return TXRX_CONTINUE;
}

static ieee80211_txrx_result
ieee80211_rx_h_passive_scan(struct ieee80211_txrx_data *rx)
{
	struct ieee80211_local *local = rx->local;
	struct sk_buff *skb = rx->skb;

	if (unlikely(local->sta_scanning != 0)) {
		ieee80211_sta_rx_scan(rx->dev, skb, rx->u.rx.status);
		return TXRX_QUEUED;
	}

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	if (unlikely(rx->flags & IEEE80211_TXRXD_RXIN_SCAN)) {
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		/* scanning finished during invoking of handlers */
		I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
		return TXRX_DROP;
	}

	return TXRX_CONTINUE;
}

static ieee80211_txrx_result
ieee80211_rx_h_check(struct ieee80211_txrx_data *rx)
{
	struct ieee80211_hdr *hdr;
	hdr = (struct ieee80211_hdr *) rx->skb->data;

	/* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
	if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
		if (unlikely(rx->fc & IEEE80211_FCTL_RETRY &&
			     rx->sta->last_seq_ctrl[rx->u.rx.queue] ==
			     hdr->seq_ctrl)) {
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			if (rx->flags & IEEE80211_TXRXD_RXRA_MATCH) {
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				rx->local->dot11FrameDuplicateCount++;
				rx->sta->num_duplicates++;
			}
			return TXRX_DROP;
		} else
			rx->sta->last_seq_ctrl[rx->u.rx.queue] = hdr->seq_ctrl;
	}

	if (unlikely(rx->skb->len < 16)) {
		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
		return TXRX_DROP;
	}

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	if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
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		rx->skb->pkt_type = PACKET_OTHERHOST;
	else if (compare_ether_addr(rx->dev->dev_addr, hdr->addr1) == 0)
		rx->skb->pkt_type = PACKET_HOST;
	else if (is_multicast_ether_addr(hdr->addr1)) {
		if (is_broadcast_ether_addr(hdr->addr1))
			rx->skb->pkt_type = PACKET_BROADCAST;
		else
			rx->skb->pkt_type = PACKET_MULTICAST;
	} else
		rx->skb->pkt_type = PACKET_OTHERHOST;

	/* Drop disallowed frame classes based on STA auth/assoc state;
	 * IEEE 802.11, Chap 5.5.
	 *
	 * 80211.o does filtering 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 (unlikely(((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA ||
		      ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL &&
		       (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)) &&
		     rx->sdata->type != IEEE80211_IF_TYPE_IBSS &&
		     (!rx->sta || !(rx->sta->flags & WLAN_STA_ASSOC)))) {
		if ((!(rx->fc & IEEE80211_FCTL_FROMDS) &&
		     !(rx->fc & IEEE80211_FCTL_TODS) &&
		     (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)
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		    || !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
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			/* Drop IBSS frames and frames for other hosts
			 * silently. */
			return TXRX_DROP;
		}

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		return TXRX_DROP;
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	}

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	return TXRX_CONTINUE;
}


static ieee80211_txrx_result
ieee80211_rx_h_load_key(struct ieee80211_txrx_data *rx)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
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	int keyidx;
	int hdrlen;
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	struct ieee80211_key *stakey = NULL;
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	/*
	 * Key selection 101
	 *
	 * There are three types of keys:
	 *  - GTK (group keys)
	 *  - 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. Unless, of
	 * course, actual WEP keys ("pre-RSNA") are used, then unicast
	 * frames can also use key indizes like GTKs. Hence, if we don't
	 * have a PTK/STK we check the key index for a WEP key.
	 *
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	 * 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.
	 *
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	 * There is also a slight problem in IBSS mode: GTKs are negotiated
	 * with each station, that is something we don't currently handle.
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	 * The spec seems to expect that one negotiates the same key with
	 * every station but there's no such requirement; VLANs could be
	 * possible.
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	 */

	if (!(rx->fc & IEEE80211_FCTL_PROTECTED))
		return TXRX_CONTINUE;
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	/*
	 * No point in finding a key if the frame is neither
	 * addressed to us nor a multicast frame.
	 */
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	if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
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		return TXRX_CONTINUE;

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	if (rx->sta)
		stakey = rcu_dereference(rx->sta->key);

	if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
		rx->key = stakey;
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	} else {
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		/*
		 * 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?
		 */
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		if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
		    (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED))
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			return TXRX_CONTINUE;

		hdrlen = ieee80211_get_hdrlen(rx->fc);

		if (rx->skb->len < 8 + hdrlen)
			return TXRX_DROP; /* TODO: count this? */

		/*
		 * no need to call ieee80211_wep_get_keyidx,
		 * it verifies a bunch of things we've done already
		 */
		keyidx = rx->skb->data[hdrlen + 3] >> 6;

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		rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
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		/*
		 * 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.
		 */
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		if (rx->key && rx->key->conf.alg != ALG_WEP &&
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		    !is_multicast_ether_addr(hdr->addr1))
			rx->key = NULL;
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	}

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	if (rx->key) {
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		rx->key->tx_rx_count++;
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		/* TODO: add threshold stuff again */
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	}

	return TXRX_CONTINUE;
}

static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)
{
	struct ieee80211_sub_if_data *sdata;
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	DECLARE_MAC_BUF(mac);

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	sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);

	if (sdata->bss)
		atomic_inc(&sdata->bss->num_sta_ps);
	sta->flags |= WLAN_STA_PS;
	sta->pspoll = 0;
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
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	printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n",
	       dev->name, print_mac(mac, sta->addr), sta->aid);
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#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
}

static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct sk_buff *skb;
	int sent = 0;
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_tx_packet_data *pkt_data;
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	DECLARE_MAC_BUF(mac);
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	sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
	if (sdata->bss)
		atomic_dec(&sdata->bss->num_sta_ps);
	sta->flags &= ~(WLAN_STA_PS | WLAN_STA_TIM);
	sta->pspoll = 0;
	if (!skb_queue_empty(&sta->ps_tx_buf)) {
		if (local->ops->set_tim)
			local->ops->set_tim(local_to_hw(local), sta->aid, 0);
		if (sdata->bss)
			bss_tim_clear(local, sdata->bss, sta->aid);
	}
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
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	printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n",
	       dev->name, print_mac(mac, sta->addr), sta->aid);
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#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
	/* Send all buffered frames to the station */
	while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
		pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
		sent++;
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		pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
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		dev_queue_xmit(skb);
	}
	while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
		pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
		local->total_ps_buffered--;
		sent++;
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
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		printk(KERN_DEBUG "%s: STA %s aid %d send PS frame "
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		       "since STA not sleeping anymore\n", dev->name,
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		       print_mac(mac, sta->addr), sta->aid);
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#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
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		pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
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		dev_queue_xmit(skb);
	}

	return sent;
}

static ieee80211_txrx_result
ieee80211_rx_h_sta_process(struct ieee80211_txrx_data *rx)
{
	struct sta_info *sta = rx->sta;
	struct net_device *dev = rx->dev;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;

	if (!sta)
		return TXRX_CONTINUE;

	/* Update last_rx only for IBSS packets which are for the current
	 * BSSID to avoid keeping the current IBSS network alive in cases where
	 * other STAs are using different BSSID. */
	if (rx->sdata->type == IEEE80211_IF_TYPE_IBSS) {
		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len);
		if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0)
			sta->last_rx = jiffies;
	} else
	if (!is_multicast_ether_addr(hdr->addr1) ||
	    rx->sdata->type == IEEE80211_IF_TYPE_STA) {
		/* Update last_rx only for unicast frames in order to prevent
		 * the Probe Request frames (the only broadcast frames from a
		 * STA in infrastructure mode) from keeping a connection alive.
		 */
		sta->last_rx = jiffies;
	}

606
	if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
607 608 609 610
		return TXRX_CONTINUE;

	sta->rx_fragments++;
	sta->rx_bytes += rx->skb->len;
611 612 613
	sta->last_rssi = rx->u.rx.status->ssi;
	sta->last_signal = rx->u.rx.status->signal;
	sta->last_noise = rx->u.rx.status->noise;
614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644

	if (!(rx->fc & IEEE80211_FCTL_MOREFRAGS)) {
		/* Change STA power saving mode only in the end of a frame
		 * exchange sequence */
		if ((sta->flags & WLAN_STA_PS) && !(rx->fc & IEEE80211_FCTL_PM))
			rx->u.rx.sent_ps_buffered += ap_sta_ps_end(dev, sta);
		else if (!(sta->flags & WLAN_STA_PS) &&
			 (rx->fc & IEEE80211_FCTL_PM))
			ap_sta_ps_start(dev, sta);
	}

	/* Drop data::nullfunc frames silently, since they are used only to
	 * control station power saving mode. */
	if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
	    (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_NULLFUNC) {
		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
		/* Update counter and free packet here to avoid counting this
		 * as a dropped packed. */
		sta->rx_packets++;
		dev_kfree_skb(rx->skb);
		return TXRX_QUEUED;
	}

	return TXRX_CONTINUE;
} /* ieee80211_rx_h_sta_process */

static ieee80211_txrx_result
ieee80211_rx_h_wep_weak_iv_detection(struct ieee80211_txrx_data *rx)
{
	if (!rx->sta || !(rx->fc & IEEE80211_FCTL_PROTECTED) ||
	    (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
645
	    !rx->key || rx->key->conf.alg != ALG_WEP ||
646
	    !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
647 648 649
		return TXRX_CONTINUE;

	/* Check for weak IVs, if hwaccel did not remove IV from the frame */
650 651
	if (!(rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED) ||
	    !(rx->u.rx.status->flag & RX_FLAG_DECRYPTED))
652
		if (ieee80211_wep_is_weak_iv(rx->skb, rx->key))
653 654 655 656 657 658
			rx->sta->wep_weak_iv_count++;

	return TXRX_CONTINUE;
}

static ieee80211_txrx_result
659
ieee80211_rx_h_decrypt(struct ieee80211_txrx_data *rx)
660
{
661
	if (!(rx->fc & IEEE80211_FCTL_PROTECTED))
662 663 664
		return TXRX_CONTINUE;

	if (!rx->key) {
665
		if (net_ratelimit())
666 667
			printk(KERN_DEBUG "%s: RX protected frame,"
			       " but have no key\n", rx->dev->name);
668 669 670
		return TXRX_DROP;
	}

671 672 673 674 675 676 677 678 679
	switch (rx->key->conf.alg) {
	case ALG_WEP:
		return ieee80211_crypto_wep_decrypt(rx);
	case ALG_TKIP:
		return ieee80211_crypto_tkip_decrypt(rx);
	case ALG_CCMP:
		return ieee80211_crypto_ccmp_decrypt(rx);
	case ALG_NONE:
		return TXRX_CONTINUE;
680 681
	}

682 683 684
	/* not reached */
	WARN_ON(1);
	return TXRX_DROP;
685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703
}

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;
	int idx;

	idx = sdata->fragment_next;
	entry = &sdata->fragments[sdata->fragment_next++];
	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
		sdata->fragment_next = 0;

	if (!skb_queue_empty(&entry->skb_list)) {
#ifdef CONFIG_MAC80211_DEBUG
		struct ieee80211_hdr *hdr =
			(struct ieee80211_hdr *) entry->skb_list.next->data;
704 705
		DECLARE_MAC_BUF(mac);
		DECLARE_MAC_BUF(mac2);
706 707
		printk(KERN_DEBUG "%s: RX reassembly removed oldest "
		       "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
708
		       "addr1=%s addr2=%s\n",
709 710
		       sdata->dev->name, idx,
		       jiffies - entry->first_frag_time, entry->seq,
711 712
		       entry->last_frag, print_mac(mac, hdr->addr1),
		       print_mac(mac2, hdr->addr2));
713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777
#endif /* CONFIG_MAC80211_DEBUG */
		__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,
			  u16 fc, 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;
		u16 f_fc;

		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;
		f_fc = le16_to_cpu(f_hdr->frame_control);

		if ((fc & IEEE80211_FCTL_FTYPE) != (f_fc & IEEE80211_FCTL_FTYPE) ||
		    compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
		    compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
			continue;

		if (entry->first_frag_time + 2 * HZ < jiffies) {
			__skb_queue_purge(&entry->skb_list);
			continue;
		}
		return entry;
	}

	return NULL;
}

static ieee80211_txrx_result
ieee80211_rx_h_defragment(struct ieee80211_txrx_data *rx)
{
	struct ieee80211_hdr *hdr;
	u16 sc;
	unsigned int frag, seq;
	struct ieee80211_fragment_entry *entry;
	struct sk_buff *skb;
778
	DECLARE_MAC_BUF(mac);
779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797

	hdr = (struct ieee80211_hdr *) rx->skb->data;
	sc = le16_to_cpu(hdr->seq_ctrl);
	frag = sc & IEEE80211_SCTL_FRAG;

	if (likely((!(rx->fc & IEEE80211_FCTL_MOREFRAGS) && frag == 0) ||
		   (rx->skb)->len < 24 ||
		   is_multicast_ether_addr(hdr->addr1))) {
		/* not fragmented */
		goto out;
	}
	I802_DEBUG_INC(rx->local->rx_handlers_fragments);

	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->u.rx.queue, &(rx->skb));
798
		if (rx->key && rx->key->conf.alg == ALG_CCMP &&
799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824
		    (rx->fc & IEEE80211_FCTL_PROTECTED)) {
			/* 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[rx->u.rx.queue],
			       CCMP_PN_LEN);
		}
		return TXRX_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, rx->fc, frag, seq,
					  rx->u.rx.queue, hdr);
	if (!entry) {
		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
		return TXRX_DROP;
	}

	/* 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[CCMP_PN_LEN], *rpn;
825
		if (!rx->key || rx->key->conf.alg != ALG_CCMP)
826 827 828 829 830 831 832 833 834
			return TXRX_DROP;
		memcpy(pn, entry->last_pn, CCMP_PN_LEN);
		for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
			pn[i]++;
			if (pn[i])
				break;
		}
		rpn = rx->key->u.ccmp.rx_pn[rx->u.rx.queue];
		if (memcmp(pn, rpn, CCMP_PN_LEN) != 0) {
835 836
			if (net_ratelimit())
				printk(KERN_DEBUG "%s: defrag: CCMP PN not "
837
				       "sequential A2=%s"
838 839
				       " PN=%02x%02x%02x%02x%02x%02x "
				       "(expected %02x%02x%02x%02x%02x%02x)\n",
840
				       rx->dev->name, print_mac(mac, hdr->addr2),
841 842 843
				       rpn[0], rpn[1], rpn[2], rpn[3], rpn[4],
				       rpn[5], pn[0], pn[1], pn[2], pn[3],
				       pn[4], pn[5]);
844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873
			return TXRX_DROP;
		}
		memcpy(entry->last_pn, pn, CCMP_PN_LEN);
	}

	skb_pull(rx->skb, ieee80211_get_hdrlen(rx->fc));
	__skb_queue_tail(&entry->skb_list, rx->skb);
	entry->last_frag = frag;
	entry->extra_len += rx->skb->len;
	if (rx->fc & IEEE80211_FCTL_MOREFRAGS) {
		rx->skb = NULL;
		return TXRX_QUEUED;
	}

	rx->skb = __skb_dequeue(&entry->skb_list);
	if (skb_tailroom(rx->skb) < entry->extra_len) {
		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
					      GFP_ATOMIC))) {
			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
			__skb_queue_purge(&entry->skb_list);
			return TXRX_DROP;
		}
	}
	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 */
874
	rx->flags |= IEEE80211_TXRXD_FRAGMENTED;
875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890

 out:
	if (rx->sta)
		rx->sta->rx_packets++;
	if (is_multicast_ether_addr(hdr->addr1))
		rx->local->dot11MulticastReceivedFrameCount++;
	else
		ieee80211_led_rx(rx->local);
	return TXRX_CONTINUE;
}

static ieee80211_txrx_result
ieee80211_rx_h_ps_poll(struct ieee80211_txrx_data *rx)
{
	struct sk_buff *skb;
	int no_pending_pkts;
891
	DECLARE_MAC_BUF(mac);
892 893 894 895

	if (likely(!rx->sta ||
		   (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL ||
		   (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PSPOLL ||
896
		   !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)))
897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916
		return TXRX_CONTINUE;

	skb = skb_dequeue(&rx->sta->tx_filtered);
	if (!skb) {
		skb = skb_dequeue(&rx->sta->ps_tx_buf);
		if (skb)
			rx->local->total_ps_buffered--;
	}
	no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
		skb_queue_empty(&rx->sta->ps_tx_buf);

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

		/* tell TX path to send one frame even though the STA may
		 * still remain is PS mode after this frame exchange */
		rx->sta->pspoll = 1;

#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
917 918
		printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n",
		       print_mac(mac, rx->sta->addr), rx->sta->aid,
919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940
		       skb_queue_len(&rx->sta->ps_tx_buf));
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */

		/* Use MoreData flag to indicate whether there are more
		 * buffered frames for this STA */
		if (no_pending_pkts) {
			hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
			rx->sta->flags &= ~WLAN_STA_TIM;
		} else
			hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);

		dev_queue_xmit(skb);

		if (no_pending_pkts) {
			if (rx->local->ops->set_tim)
				rx->local->ops->set_tim(local_to_hw(rx->local),
						       rx->sta->aid, 0);
			if (rx->sdata->bss)
				bss_tim_clear(rx->local, rx->sdata->bss, rx->sta->aid);
		}
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
	} else if (!rx->u.rx.sent_ps_buffered) {
941
		printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
942
		       "though there is no buffered frames for it\n",
943
		       rx->dev->name, print_mac(mac, rx->sta->addr));
944 945 946 947 948 949 950 951 952 953 954
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */

	}

	/* Free PS Poll skb here instead of returning TXRX_DROP that would
	 * count as an dropped frame. */
	dev_kfree_skb(rx->skb);

	return TXRX_QUEUED;
}

955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974
static ieee80211_txrx_result
ieee80211_rx_h_remove_qos_control(struct ieee80211_txrx_data *rx)
{
	u16 fc = rx->fc;
	u8 *data = rx->skb->data;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) data;

	if (!WLAN_FC_IS_QOS_DATA(fc))
		return TXRX_CONTINUE;

	/* remove the qos control field, update frame type and meta-data */
	memmove(data + 2, data, ieee80211_get_hdrlen(fc) - 2);
	hdr = (struct ieee80211_hdr *) skb_pull(rx->skb, 2);
	/* change frame type to non QOS */
	rx->fc = fc &= ~IEEE80211_STYPE_QOS_DATA;
	hdr->frame_control = cpu_to_le16(fc);

	return TXRX_CONTINUE;
}

975 976 977 978
static ieee80211_txrx_result
ieee80211_rx_h_802_1x_pae(struct ieee80211_txrx_data *rx)
{
	if (rx->sdata->eapol && ieee80211_is_eapol(rx->skb) &&
979
	    rx->sdata->type != IEEE80211_IF_TYPE_STA &&
980 981
	    (rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
		return TXRX_CONTINUE;
982 983 984 985 986 987 988 989 990

	if (unlikely(rx->sdata->ieee802_1x &&
		     (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
		     (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
		     (!rx->sta || !(rx->sta->flags & WLAN_STA_AUTHORIZED)) &&
		     !ieee80211_is_eapol(rx->skb))) {
#ifdef CONFIG_MAC80211_DEBUG
		struct ieee80211_hdr *hdr =
			(struct ieee80211_hdr *) rx->skb->data;
991 992
		DECLARE_MAC_BUF(mac);
		printk(KERN_DEBUG "%s: dropped frame from %s"
993
		       " (unauthorized port)\n", rx->dev->name,
994
		       print_mac(mac, hdr->addr2));
995 996 997 998 999 1000 1001 1002 1003 1004
#endif /* CONFIG_MAC80211_DEBUG */
		return TXRX_DROP;
	}

	return TXRX_CONTINUE;
}

static ieee80211_txrx_result
ieee80211_rx_h_drop_unencrypted(struct ieee80211_txrx_data *rx)
{
1005
	/*
1006 1007
	 * Pass through unencrypted frames if the hardware has
	 * decrypted them already.
1008
	 */
1009
	if (rx->u.rx.status->flag & RX_FLAG_DECRYPTED)
1010 1011 1012 1013 1014 1015 1016 1017 1018
		return TXRX_CONTINUE;

	/* Drop unencrypted frames if key is set. */
	if (unlikely(!(rx->fc & IEEE80211_FCTL_PROTECTED) &&
		     (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
		     (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
		     (rx->key || rx->sdata->drop_unencrypted) &&
		     (rx->sdata->eapol == 0 ||
		      !ieee80211_is_eapol(rx->skb)))) {
1019 1020 1021
		if (net_ratelimit())
			printk(KERN_DEBUG "%s: RX non-WEP frame, but expected "
			       "encryption\n", rx->dev->name);
1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038
		return TXRX_DROP;
	}
	return TXRX_CONTINUE;
}

static ieee80211_txrx_result
ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
{
	struct net_device *dev = rx->dev;
	struct ieee80211_local *local = rx->local;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
	u16 fc, hdrlen, ethertype;
	u8 *payload;
	u8 dst[ETH_ALEN];
	u8 src[ETH_ALEN];
	struct sk_buff *skb = rx->skb, *skb2;
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1039 1040 1041 1042
	DECLARE_MAC_BUF(mac);
	DECLARE_MAC_BUF(mac2);
	DECLARE_MAC_BUF(mac3);
	DECLARE_MAC_BUF(mac4);
1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070

	fc = rx->fc;
	if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
		return TXRX_CONTINUE;

	if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
		return TXRX_DROP;

	hdrlen = ieee80211_get_hdrlen(fc);

	/* convert IEEE 802.11 header + possible LLC headers into Ethernet
	 * header
	 * IEEE 802.11 address fields:
	 * ToDS FromDS Addr1 Addr2 Addr3 Addr4
	 *   0     0   DA    SA    BSSID n/a
	 *   0     1   DA    BSSID SA    n/a
	 *   1     0   BSSID SA    DA    n/a
	 *   1     1   RA    TA    DA    SA
	 */

	switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
	case IEEE80211_FCTL_TODS:
		/* BSSID SA DA */
		memcpy(dst, hdr->addr3, ETH_ALEN);
		memcpy(src, hdr->addr2, ETH_ALEN);

		if (unlikely(sdata->type != IEEE80211_IF_TYPE_AP &&
			     sdata->type != IEEE80211_IF_TYPE_VLAN)) {
1071 1072
			if (net_ratelimit())
				printk(KERN_DEBUG "%s: dropped ToDS frame "
1073
				       "(BSSID=%s SA=%s DA=%s)\n",
1074
				       dev->name,
1075 1076 1077
				       print_mac(mac, hdr->addr1),
				       print_mac(mac2, hdr->addr2),
				       print_mac(mac3, hdr->addr3));
1078 1079 1080 1081 1082 1083 1084 1085 1086
			return TXRX_DROP;
		}
		break;
	case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
		/* RA TA DA SA */
		memcpy(dst, hdr->addr3, ETH_ALEN);
		memcpy(src, hdr->addr4, ETH_ALEN);

		if (unlikely(sdata->type != IEEE80211_IF_TYPE_WDS)) {
1087 1088
			if (net_ratelimit())
				printk(KERN_DEBUG "%s: dropped FromDS&ToDS "
1089
				       "frame (RA=%s TA=%s DA=%s SA=%s)\n",
1090
				       rx->dev->name,
1091 1092 1093 1094
				       print_mac(mac, hdr->addr1),
				       print_mac(mac2, hdr->addr2),
				       print_mac(mac3, hdr->addr3),
				       print_mac(mac4, hdr->addr4));
1095 1096 1097 1098 1099 1100 1101 1102
			return TXRX_DROP;
		}
		break;
	case IEEE80211_FCTL_FROMDS:
		/* DA BSSID SA */
		memcpy(dst, hdr->addr1, ETH_ALEN);
		memcpy(src, hdr->addr3, ETH_ALEN);

1103 1104 1105
		if (sdata->type != IEEE80211_IF_TYPE_STA ||
		    (is_multicast_ether_addr(dst) &&
		     !compare_ether_addr(src, dev->dev_addr)))
1106 1107 1108 1109 1110 1111 1112 1113 1114
			return TXRX_DROP;
		break;
	case 0:
		/* DA SA BSSID */
		memcpy(dst, hdr->addr1, ETH_ALEN);
		memcpy(src, hdr->addr2, ETH_ALEN);

		if (sdata->type != IEEE80211_IF_TYPE_IBSS) {
			if (net_ratelimit()) {
1115 1116 1117 1118 1119 1120
				printk(KERN_DEBUG "%s: dropped IBSS frame "
				       "(DA=%s SA=%s BSSID=%s)\n",
				       dev->name,
				       print_mac(mac, hdr->addr1),
				       print_mac(mac2, hdr->addr2),
				       print_mac(mac3, hdr->addr3));
1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160
			}
			return TXRX_DROP;
		}
		break;
	}

	payload = skb->data + hdrlen;

	if (unlikely(skb->len - hdrlen < 8)) {
		if (net_ratelimit()) {
			printk(KERN_DEBUG "%s: RX too short data frame "
			       "payload\n", dev->name);
		}
		return TXRX_DROP;
	}

	ethertype = (payload[6] << 8) | payload[7];

	if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
		    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
		   compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
		/* remove RFC1042 or Bridge-Tunnel encapsulation and
		 * replace EtherType */
		skb_pull(skb, hdrlen + 6);
		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
	} else {
		struct ethhdr *ehdr;
		__be16 len;
		skb_pull(skb, hdrlen);
		len = htons(skb->len);
		ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
		memcpy(ehdr->h_dest, dst, ETH_ALEN);
		memcpy(ehdr->h_source, src, ETH_ALEN);
		ehdr->h_proto = len;
	}
	skb->dev = dev;

	skb2 = NULL;

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	dev->stats.rx_packets++;
	dev->stats.rx_bytes += skb->len;
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	if (local->bridge_packets && (sdata->type == IEEE80211_IF_TYPE_AP
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	    || sdata->type == IEEE80211_IF_TYPE_VLAN) &&
	    (rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
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		if (is_multicast_ether_addr(skb->data)) {
			/* send multicast frames both to higher layers in
			 * local net stack and back to the wireless media */
			skb2 = skb_copy(skb, GFP_ATOMIC);
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			if (!skb2 && net_ratelimit())
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				printk(KERN_DEBUG "%s: failed to clone "
				       "multicast frame\n", dev->name);
		} else {
			struct sta_info *dsta;
			dsta = sta_info_get(local, skb->data);
			if (dsta && !dsta->dev) {
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				if (net_ratelimit())
					printk(KERN_DEBUG "Station with null "
					       "dev structure!\n");
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			} else if (dsta && dsta->dev == dev) {
				/* Destination station is associated to this
				 * AP, so send the frame directly to it and
				 * do not pass the frame to local net stack.
				 */
				skb2 = skb;
				skb = NULL;
			}
			if (dsta)
				sta_info_put(dsta);
		}
	}

	if (skb) {
		/* deliver to local stack */
		skb->protocol = eth_type_trans(skb, dev);
		memset(skb->cb, 0, sizeof(skb->cb));
		netif_rx(skb);
	}

	if (skb2) {
		/* send to wireless media */
		skb2->protocol = __constant_htons(ETH_P_802_3);
		skb_set_network_header(skb2, 0);
		skb_set_mac_header(skb2, 0);
		dev_queue_xmit(skb2);
	}

	return TXRX_QUEUED;
}

static ieee80211_txrx_result
ieee80211_rx_h_mgmt(struct ieee80211_txrx_data *rx)
{
	struct ieee80211_sub_if_data *sdata;

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	if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
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		return TXRX_DROP;

	sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
	if ((sdata->type == IEEE80211_IF_TYPE_STA ||
	     sdata->type == IEEE80211_IF_TYPE_IBSS) &&
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	    !rx->local->user_space_mlme)
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		ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->u.rx.status);
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	else
		return TXRX_DROP;

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	return TXRX_QUEUED;
}

static inline ieee80211_txrx_result __ieee80211_invoke_rx_handlers(
				struct ieee80211_local *local,
				ieee80211_rx_handler *handlers,
				struct ieee80211_txrx_data *rx,
				struct sta_info *sta)
{
	ieee80211_rx_handler *handler;
	ieee80211_txrx_result res = TXRX_DROP;

	for (handler = handlers; *handler != NULL; handler++) {
		res = (*handler)(rx);
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		switch (res) {
		case TXRX_CONTINUE:
			continue;
		case TXRX_DROP:
			I802_DEBUG_INC(local->rx_handlers_drop);
			if (sta)
				sta->rx_dropped++;
			break;
		case TXRX_QUEUED:
			I802_DEBUG_INC(local->rx_handlers_queued);
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			break;
		}
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		break;
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	}

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	if (res == TXRX_DROP)
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		dev_kfree_skb(rx->skb);
	return res;
}

static inline void ieee80211_invoke_rx_handlers(struct ieee80211_local *local,
						ieee80211_rx_handler *handlers,
						struct ieee80211_txrx_data *rx,
						struct sta_info *sta)
{
	if (__ieee80211_invoke_rx_handlers(local, handlers, rx, sta) ==
	    TXRX_CONTINUE)
		dev_kfree_skb(rx->skb);
}

static void ieee80211_rx_michael_mic_report(struct net_device *dev,
					    struct ieee80211_hdr *hdr,
					    struct sta_info *sta,
					    struct ieee80211_txrx_data *rx)
{
	int keyidx, hdrlen;
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	DECLARE_MAC_BUF(mac);
	DECLARE_MAC_BUF(mac2);
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	hdrlen = ieee80211_get_hdrlen_from_skb(rx->skb);
	if (rx->skb->len >= hdrlen + 4)
		keyidx = rx->skb->data[hdrlen + 3] >> 6;
	else
		keyidx = -1;

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	if (net_ratelimit())
		printk(KERN_DEBUG "%s: TKIP hwaccel reported Michael MIC "
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		       "failure from %s to %s keyidx=%d\n",
		       dev->name, print_mac(mac, hdr->addr2),
		       print_mac(mac2, hdr->addr1), keyidx);
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	if (!sta) {
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		/*
		 * Some hardware seem to generate incorrect Michael MIC
		 * reports; ignore them to avoid triggering countermeasures.
		 */
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		if (net_ratelimit())
			printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
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			       "error for unknown address %s\n",
			       dev->name, print_mac(mac, hdr->addr2));
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		goto ignore;
	}

	if (!(rx->fc & IEEE80211_FCTL_PROTECTED)) {
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		if (net_ratelimit())
			printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
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			       "error for a frame with no PROTECTED flag (src "
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			       "%s)\n", dev->name, print_mac(mac, hdr->addr2));
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		goto ignore;
	}

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	if (rx->sdata->type == IEEE80211_IF_TYPE_AP && keyidx) {
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		/*
		 * APs with pairwise keys should never receive Michael MIC
		 * errors for non-zero keyidx because these are reserved for
		 * group keys and only the AP is sending real multicast
		 * frames in the BSS.
		 */
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		if (net_ratelimit())
			printk(KERN_DEBUG "%s: ignored Michael MIC error for "
			       "a frame with non-zero keyidx (%d)"
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			       " (src %s)\n", dev->name, keyidx,
			       print_mac(mac, hdr->addr2));
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		goto ignore;
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	}

	if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
	    ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
	     (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)) {
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		if (net_ratelimit())
			printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
			       "error for a frame that cannot be encrypted "
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			       "(fc=0x%04x) (src %s)\n",
			       dev->name, rx->fc, print_mac(mac, hdr->addr2));
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		goto ignore;
	}

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	mac80211_ev_michael_mic_failure(rx->dev, keyidx, hdr);
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 ignore:
	dev_kfree_skb(rx->skb);
	rx->skb = NULL;
}

ieee80211_rx_handler ieee80211_rx_handlers[] =
{
	ieee80211_rx_h_if_stats,
	ieee80211_rx_h_passive_scan,
	ieee80211_rx_h_check,
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	ieee80211_rx_h_load_key,
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	ieee80211_rx_h_sta_process,
	ieee80211_rx_h_wep_weak_iv_detection,
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	ieee80211_rx_h_decrypt,
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	ieee80211_rx_h_defragment,
	ieee80211_rx_h_ps_poll,
	ieee80211_rx_h_michael_mic_verify,
	/* this must be after decryption - so header is counted in MPDU mic
	 * must be before pae and data, so QOS_DATA format frames
	 * are not passed to user space by these functions
	 */
	ieee80211_rx_h_remove_qos_control,
	ieee80211_rx_h_802_1x_pae,
	ieee80211_rx_h_drop_unencrypted,
	ieee80211_rx_h_data,
	ieee80211_rx_h_mgmt,
	NULL
};

/* main receive path */

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static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
				u8 *bssid, struct ieee80211_txrx_data *rx,
				struct ieee80211_hdr *hdr)
{
	int multicast = is_multicast_ether_addr(hdr->addr1);

	switch (sdata->type) {
	case IEEE80211_IF_TYPE_STA:
		if (!bssid)
			return 0;
		if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
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			if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
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				return 0;
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			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
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		} else if (!multicast &&
			   compare_ether_addr(sdata->dev->dev_addr,
					      hdr->addr1) != 0) {
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			if (!(sdata->dev->flags & IFF_PROMISC))
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				return 0;
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			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
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		}
		break;
	case IEEE80211_IF_TYPE_IBSS:
		if (!bssid)
			return 0;
		if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
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			if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
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				return 0;
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			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
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		} else if (!multicast &&
			   compare_ether_addr(sdata->dev->dev_addr,
					      hdr->addr1) != 0) {
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			if (!(sdata->dev->flags & IFF_PROMISC))
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