rx.c 40.8 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>
#include <net/iw_handler.h>
#include <net/mac80211.h>
#include <net/ieee80211_radiotap.h>

#include "ieee80211_i.h"
#include "ieee80211_led.h"
#include "ieee80211_common.h"
#include "wep.h"
#include "wpa.h"
#include "tkip.h"
#include "wme.h"

/* pre-rx handlers
 *
 * these don't have dev/sdata fields in the rx data
 */

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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 */
		}
	}
#ifdef CONFIG_MAC80211_DEBUG_COUNTERS
	I802_DEBUG_INC(rx->local->wme_rx_queue[tid]);
	if (rx->sta) {
		I802_DEBUG_INC(rx->sta->wme_rx_queue[tid]);
	}
#endif /* CONFIG_MAC80211_DEBUG_COUNTERS */

	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_ATHEROS_TURBO ||
	    mode->mode == MODE_ATHEROS_TURBOG ||
	    (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;
	if (rx->sta)
		rx->sta->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)
{
	rx->sdata->channel_use_raw += rx->u.rx.load;
	return TXRX_CONTINUE;
}

static void
ieee80211_rx_monitor(struct net_device *dev, struct sk_buff *skb,
		     struct ieee80211_rx_status *status)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_rate *rate;
	struct ieee80211_rtap_hdr {
		struct ieee80211_radiotap_header hdr;
		u8 flags;
		u8 rate;
		__le16 chan_freq;
		__le16 chan_flags;
		u8 antsignal;
	} __attribute__ ((packed)) *rthdr;

	skb->dev = dev;

	sdata = IEEE80211_DEV_TO_SUB_IF(dev);

	if (status->flag & RX_FLAG_RADIOTAP)
		goto out;

	if (skb_headroom(skb) < sizeof(*rthdr)) {
		I802_DEBUG_INC(local->rx_expand_skb_head);
		if (pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC)) {
			dev_kfree_skb(skb);
			return;
		}
	}

	rthdr = (struct ieee80211_rtap_hdr *) 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));
	rthdr->flags = local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS ?
		       IEEE80211_RADIOTAP_F_FCS : 0;
	rate = ieee80211_get_rate(local, status->phymode, status->rate);
	if (rate)
		rthdr->rate = rate->rate / 5;
	rthdr->chan_freq = cpu_to_le16(status->freq);
	rthdr->chan_flags =
		status->phymode == MODE_IEEE80211A ?
		cpu_to_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ) :
		cpu_to_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ);
	rthdr->antsignal = status->ssi;

 out:
	sdata->stats.rx_packets++;
	sdata->stats.rx_bytes += skb->len;

	skb_set_mac_header(skb, 0);
	skb->ip_summed = CHECKSUM_UNNECESSARY;
	skb->pkt_type = PACKET_OTHERHOST;
	skb->protocol = htons(ETH_P_802_2);
	memset(skb->cb, 0, sizeof(skb->cb));
	netif_rx(skb);
}

static ieee80211_txrx_result
ieee80211_rx_h_monitor(struct ieee80211_txrx_data *rx)
{
	if (rx->sdata->type == IEEE80211_IF_TYPE_MNTR) {
		ieee80211_rx_monitor(rx->dev, rx->skb, rx->u.rx.status);
		return TXRX_QUEUED;
	}

	if (rx->u.rx.status->flag & RX_FLAG_RADIOTAP)
		skb_pull(rx->skb, ieee80211_get_radiotap_len(rx->skb->data));

	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;
	}

	if (unlikely(rx->u.rx.in_scan)) {
		/* 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)) {
			if (rx->u.rx.ra_match) {
				rx->local->dot11FrameDuplicateCount++;
				rx->sta->num_duplicates++;
			}
			return TXRX_DROP;
		} else
			rx->sta->last_seq_ctrl[rx->u.rx.queue] = hdr->seq_ctrl;
	}

	if ((rx->local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) &&
	    rx->skb->len > FCS_LEN)
		skb_trim(rx->skb, rx->skb->len - FCS_LEN);

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

	if (!rx->u.rx.ra_match)
		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)
		    || !rx->u.rx.ra_match) {
			/* Drop IBSS frames and frames for other hosts
			 * silently. */
			return TXRX_DROP;
		}

		if (!rx->local->apdev)
			return TXRX_DROP;

		ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
				  ieee80211_msg_sta_not_assoc);
		return TXRX_QUEUED;
	}

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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;
	int always_sta_key;

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	if (rx->sdata->type == IEEE80211_IF_TYPE_STA)
		always_sta_key = 0;
	else
		always_sta_key = 1;

	if (rx->sta && rx->sta->key && always_sta_key) {
		rx->key = rx->sta->key;
	} else {
		if (rx->sta && rx->sta->key)
			rx->key = rx->sta->key;
		else
			rx->key = rx->sdata->default_key;

		if ((rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) &&
		    rx->fc & IEEE80211_FCTL_PROTECTED) {
			int keyidx = ieee80211_wep_get_keyidx(rx->skb);

			if (keyidx >= 0 && keyidx < NUM_DEFAULT_KEYS &&
			    (!rx->sta || !rx->sta->key || keyidx > 0))
				rx->key = rx->sdata->keys[keyidx];

			if (!rx->key) {
				if (!rx->u.rx.ra_match)
					return TXRX_DROP;
				printk(KERN_DEBUG "%s: RX WEP frame with "
				       "unknown keyidx %d (A1=" MAC_FMT " A2="
				       MAC_FMT " A3=" MAC_FMT ")\n",
				       rx->dev->name, keyidx,
				       MAC_ARG(hdr->addr1),
				       MAC_ARG(hdr->addr2),
				       MAC_ARG(hdr->addr3));
				if (!rx->local->apdev)
					return TXRX_DROP;
				ieee80211_rx_mgmt(
					rx->local, rx->skb, rx->u.rx.status,
					ieee80211_msg_wep_frame_unknown_key);
				return TXRX_QUEUED;
			}
		}
	}

	if (rx->fc & IEEE80211_FCTL_PROTECTED && rx->key && rx->u.rx.ra_match) {
		rx->key->tx_rx_count++;
		if (unlikely(rx->local->key_tx_rx_threshold &&
			     rx->key->tx_rx_count >
			     rx->local->key_tx_rx_threshold)) {
			ieee80211_key_threshold_notify(rx->dev, rx->key,
						       rx->sta);
		}
	}

	return TXRX_CONTINUE;
}

static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)
{
	struct ieee80211_sub_if_data *sdata;
	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
	printk(KERN_DEBUG "%s: STA " MAC_FMT " aid %d enters power "
	       "save mode\n", dev->name, MAC_ARG(sta->addr), sta->aid);
#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;

	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
	printk(KERN_DEBUG "%s: STA " MAC_FMT " aid %d exits power "
	       "save mode\n", dev->name, MAC_ARG(sta->addr), sta->aid);
#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++;
		pkt_data->requeue = 1;
		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
		printk(KERN_DEBUG "%s: STA " MAC_FMT " aid %d send PS frame "
		       "since STA not sleeping anymore\n", dev->name,
		       MAC_ARG(sta->addr), sta->aid);
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
		pkt_data->requeue = 1;
		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;
	}

	if (!rx->u.rx.ra_match)
		return TXRX_CONTINUE;

	sta->rx_fragments++;
	sta->rx_bytes += rx->skb->len;
	sta->last_rssi = (sta->last_rssi * 15 +
			  rx->u.rx.status->ssi) / 16;
	sta->last_signal = (sta->last_signal * 15 +
			    rx->u.rx.status->signal) / 16;
	sta->last_noise = (sta->last_noise * 15 +
			   rx->u.rx.status->noise) / 16;

	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 ||
	    !rx->key || rx->key->alg != ALG_WEP || !rx->u.rx.ra_match)
		return TXRX_CONTINUE;

	/* Check for weak IVs, if hwaccel did not remove IV from the frame */
	if ((rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) ||
	    rx->key->force_sw_encrypt) {
		u8 *iv = ieee80211_wep_is_weak_iv(rx->skb, rx->key);
		if (iv) {
			rx->sta->wep_weak_iv_count++;
		}
	}

	return TXRX_CONTINUE;
}

static ieee80211_txrx_result
ieee80211_rx_h_wep_decrypt(struct ieee80211_txrx_data *rx)
{
	/* If the device handles decryption totally, skip this test */
	if (rx->local->hw.flags & IEEE80211_HW_DEVICE_HIDES_WEP)
		return TXRX_CONTINUE;

	if ((rx->key && rx->key->alg != ALG_WEP) ||
	    !(rx->fc & IEEE80211_FCTL_PROTECTED) ||
	    ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
	     ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
	      (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)))
		return TXRX_CONTINUE;

	if (!rx->key) {
		printk(KERN_DEBUG "%s: RX WEP frame, but no key set\n",
		       rx->dev->name);
		return TXRX_DROP;
	}

	if (!(rx->u.rx.status->flag & RX_FLAG_DECRYPTED) ||
	    rx->key->force_sw_encrypt) {
		if (ieee80211_wep_decrypt(rx->local, rx->skb, rx->key)) {
			printk(KERN_DEBUG "%s: RX WEP frame, decrypt "
			       "failed\n", rx->dev->name);
			return TXRX_DROP;
		}
	} else if (rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) {
		ieee80211_wep_remove_iv(rx->local, rx->skb, rx->key);
		/* remove ICV */
		skb_trim(rx->skb, rx->skb->len - 4);
	}

	return TXRX_CONTINUE;
}

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;
		printk(KERN_DEBUG "%s: RX reassembly removed oldest "
		       "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
		       "addr1=" MAC_FMT " addr2=" MAC_FMT "\n",
		       sdata->dev->name, idx,
		       jiffies - entry->first_frag_time, entry->seq,
		       entry->last_frag, MAC_ARG(hdr->addr1),
		       MAC_ARG(hdr->addr2));
#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;

	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));
		if (rx->key && rx->key->alg == ALG_CCMP &&
		    (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;
		if (!rx->key || rx->key->alg != ALG_CCMP)
			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) {
			printk(KERN_DEBUG "%s: defrag: CCMP PN not sequential"
			       " A2=" MAC_FMT " PN=%02x%02x%02x%02x%02x%02x "
			       "(expected %02x%02x%02x%02x%02x%02x)\n",
			       rx->dev->name, MAC_ARG(hdr->addr2),
			       rpn[0], rpn[1], rpn[2], rpn[3], rpn[4], rpn[5],
			       pn[0], pn[1], pn[2], pn[3], pn[4], pn[5]);
			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 */
	rx->fragmented = 1;

 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;

	if (likely(!rx->sta ||
		   (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL ||
		   (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PSPOLL ||
		   !rx->u.rx.ra_match))
		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
		printk(KERN_DEBUG "STA " MAC_FMT " aid %d: PS Poll (entries "
		       "after %d)\n",
		       MAC_ARG(rx->sta->addr), rx->sta->aid,
		       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) {
		printk(KERN_DEBUG "%s: STA " MAC_FMT " sent PS Poll even "
		       "though there is no buffered frames for it\n",
		       rx->dev->name, MAC_ARG(rx->sta->addr));
#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;
}

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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;
}

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static ieee80211_txrx_result
ieee80211_rx_h_802_1x_pae(struct ieee80211_txrx_data *rx)
{
	if (rx->sdata->eapol && ieee80211_is_eapol(rx->skb) &&
	    rx->sdata->type != IEEE80211_IF_TYPE_STA && rx->u.rx.ra_match) {
		/* Pass both encrypted and unencrypted EAPOL frames to user
		 * space for processing. */
		if (!rx->local->apdev)
			return TXRX_DROP;
		ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
				  ieee80211_msg_normal);
		return TXRX_QUEUED;
	}

	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;
		printk(KERN_DEBUG "%s: dropped frame from " MAC_FMT
		       " (unauthorized port)\n", rx->dev->name,
		       MAC_ARG(hdr->addr2));
#endif /* CONFIG_MAC80211_DEBUG */
		return TXRX_DROP;
	}

	return TXRX_CONTINUE;
}

static ieee80211_txrx_result
ieee80211_rx_h_drop_unencrypted(struct ieee80211_txrx_data *rx)
{
	/*  If the device handles decryption totally, skip this test */
	if (rx->local->hw.flags & IEEE80211_HW_DEVICE_HIDES_WEP)
		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)))) {
		printk(KERN_DEBUG "%s: RX non-WEP frame, but expected "
		       "encryption\n", rx->dev->name);
		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);

	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)) {
			printk(KERN_DEBUG "%s: dropped ToDS frame (BSSID="
			       MAC_FMT " SA=" MAC_FMT " DA=" MAC_FMT ")\n",
			       dev->name, MAC_ARG(hdr->addr1),
			       MAC_ARG(hdr->addr2), MAC_ARG(hdr->addr3));
			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)) {
			printk(KERN_DEBUG "%s: dropped FromDS&ToDS frame (RA="
			       MAC_FMT " TA=" MAC_FMT " DA=" MAC_FMT " SA="
			       MAC_FMT ")\n",
			       rx->dev->name, MAC_ARG(hdr->addr1),
			       MAC_ARG(hdr->addr2), MAC_ARG(hdr->addr3),
			       MAC_ARG(hdr->addr4));
			return TXRX_DROP;
		}
		break;
	case IEEE80211_FCTL_FROMDS:
		/* DA BSSID SA */
		memcpy(dst, hdr->addr1, ETH_ALEN);
		memcpy(src, hdr->addr3, ETH_ALEN);

		if (sdata->type != IEEE80211_IF_TYPE_STA) {
			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()) {
				printk(KERN_DEBUG "%s: dropped IBSS frame (DA="
				       MAC_FMT " SA=" MAC_FMT " BSSID=" MAC_FMT
				       ")\n",
				       dev->name, MAC_ARG(hdr->addr1),
				       MAC_ARG(hdr->addr2),
				       MAC_ARG(hdr->addr3));
			}
			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;

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

	if (local->bridge_packets && (sdata->type == IEEE80211_IF_TYPE_AP
	    || sdata->type == IEEE80211_IF_TYPE_VLAN) && rx->u.rx.ra_match) {
		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);
			if (!skb2)
				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) {
				printk(KERN_DEBUG "Station with null dev "
				       "structure!\n");
			} 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;

	if (!rx->u.rx.ra_match)
		return TXRX_DROP;

	sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
	if ((sdata->type == IEEE80211_IF_TYPE_STA ||
	     sdata->type == IEEE80211_IF_TYPE_IBSS) &&
	    !rx->local->user_space_mlme) {
		ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->u.rx.status);
	} else {
		/* Management frames are sent to hostapd for processing */
		if (!rx->local->apdev)
			return TXRX_DROP;
		ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
				  ieee80211_msg_normal);
	}
	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;

	hdrlen = ieee80211_get_hdrlen_from_skb(rx->skb);
	if (rx->skb->len >= hdrlen + 4)
		keyidx = rx->skb->data[hdrlen + 3] >> 6;
	else
		keyidx = -1;

	/* TODO: verify that this is not triggered by fragmented
	 * frames (hw does not verify MIC for them). */
	printk(KERN_DEBUG "%s: TKIP hwaccel reported Michael MIC "
	       "failure from " MAC_FMT " to " MAC_FMT " keyidx=%d\n",
	       dev->name, MAC_ARG(hdr->addr2), MAC_ARG(hdr->addr1), keyidx);

	if (!sta) {
		/* Some hardware versions seem to generate incorrect
		 * Michael MIC reports; ignore them to avoid triggering
		 * countermeasures. */
		printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
		       "error for unknown address " MAC_FMT "\n",
		       dev->name, MAC_ARG(hdr->addr2));
		goto ignore;
	}

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

	if ((rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) &&
	    rx->sdata->type == IEEE80211_IF_TYPE_AP) {
		keyidx = ieee80211_wep_get_keyidx(rx->skb);
		/* AP with Pairwise keys support 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 BSS. */
		if (keyidx) {
			printk(KERN_DEBUG "%s: ignored Michael MIC error for "
			       "a frame with non-zero keyidx (%d) (src " MAC_FMT
			       ")\n", dev->name, keyidx, MAC_ARG(hdr->addr2));
			goto ignore;
		}
	}

	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)) {
		printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
		       "error for a frame that cannot be encrypted "
		       "(fc=0x%04x) (src " MAC_FMT ")\n",
		       dev->name, rx->fc, MAC_ARG(hdr->addr2));
		goto ignore;
	}

	do {
		union iwreq_data wrqu;
		char *buf = kmalloc(128, GFP_ATOMIC);
		if (!buf)
			break;

		/* TODO: needed parameters: count, key type, TSC */
		sprintf(buf, "MLME-MICHAELMICFAILURE.indication("
			"keyid=%d %scast addr=" MAC_FMT ")",
			keyidx, hdr->addr1[0] & 0x01 ? "broad" : "uni",
			MAC_ARG(hdr->addr2));
		memset(&wrqu, 0, sizeof(wrqu));
		wrqu.data.length = strlen(buf);
		wireless_send_event(rx->dev, IWEVCUSTOM, &wrqu, buf);
		kfree(buf);
	} while (0);

	/* TODO: consider verifying the MIC error report with software
	 * implementation if we get too many spurious reports from the
	 * hardware. */
	if (!rx->local->apdev)
		goto ignore;
	ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
			  ieee80211_msg_michael_mic_failure);
	return;

 ignore:
	dev_kfree_skb(rx->skb);
	rx->skb = NULL;
}

ieee80211_rx_handler ieee80211_rx_handlers[] =
{
	ieee80211_rx_h_if_stats,
	ieee80211_rx_h_monitor,
	ieee80211_rx_h_passive_scan,
	ieee80211_rx_h_check,
1220
	ieee80211_rx_h_load_key,
1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242
	ieee80211_rx_h_sta_process,
	ieee80211_rx_h_ccmp_decrypt,
	ieee80211_rx_h_tkip_decrypt,
	ieee80211_rx_h_wep_weak_iv_detection,
	ieee80211_rx_h_wep_decrypt,
	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 */

1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309
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)) {
			if (!rx->u.rx.in_scan)
				return 0;
			rx->u.rx.ra_match = 0;
		} else if (!multicast &&
			   compare_ether_addr(sdata->dev->dev_addr,
					      hdr->addr1) != 0) {
			if (!sdata->promisc)
				return 0;
			rx->u.rx.ra_match = 0;
		}
		break;
	case IEEE80211_IF_TYPE_IBSS:
		if (!bssid)
			return 0;
		if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
			if (!rx->u.rx.in_scan)
				return 0;
			rx->u.rx.ra_match = 0;
		} else if (!multicast &&
			   compare_ether_addr(sdata->dev->dev_addr,
					      hdr->addr1) != 0) {
			if (!sdata->promisc)
				return 0;
			rx->u.rx.ra_match = 0;
		} else if (!rx->sta)
			rx->sta = ieee80211_ibss_add_sta(sdata->dev, rx->skb,
							 bssid, hdr->addr2);
		break;
	case IEEE80211_IF_TYPE_AP:
		if (!bssid) {
			if (compare_ether_addr(sdata->dev->dev_addr,
					       hdr->addr1))
				return 0;
		} else if (!ieee80211_bssid_match(bssid,
					sdata->dev->dev_addr)) {
			if (!rx->u.rx.in_scan)
				return 0;
			rx->u.rx.ra_match = 0;
		}
		if (sdata->dev == sdata->local->mdev && !rx->u.rx.in_scan)
			/* do not receive anything via
			 * master device when not scanning */
			return 0;
		break;
	case IEEE80211_IF_TYPE_WDS:
		if (bssid ||
		    (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
			return 0;
		if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
			return 0;
		break;
	}

	return 1;
}

1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322
/*
 * 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_rx_status *status)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_sub_if_data *sdata;
	struct sta_info *sta;
	struct ieee80211_hdr *hdr;
	struct ieee80211_txrx_data rx;
	u16 type;
1323
	int radiotap_len = 0, prepres;
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	struct ieee80211_sub_if_data *prev = NULL;
	struct sk_buff *skb_new;
	u8 *bssid;
1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343

	if (status->flag & RX_FLAG_RADIOTAP) {
		radiotap_len = ieee80211_get_radiotap_len(skb->data);
		skb_pull(skb, radiotap_len);
	}

	hdr = (struct ieee80211_hdr *) skb->data;
	memset(&rx, 0, sizeof(rx));
	rx.skb = skb;
	rx.local = local;

	rx.u.rx.status = status;
	rx.fc = skb->len >= 2 ? le16_to_cpu(hdr->frame_control) : 0;
	type = rx.fc & IEEE80211_FCTL_FTYPE;
	if (type == IEEE80211_FTYPE_DATA || type == IEEE80211_FTYPE_MGMT)
		local->dot11ReceivedFragmentCount++;

1344
	if (skb->len >= 16) {
1345
		sta = rx.sta = sta_info_get(local, hdr->addr2);
1346 1347 1348 1349 1350
		if (sta) {
			rx.dev = rx.sta->dev;
			rx.sdata = IEEE80211_DEV_TO_SUB_IF(rx.dev);
		}
	} else
1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367
		sta = rx.sta = NULL;

	if ((status->flag & RX_FLAG_MMIC_ERROR)) {
		ieee80211_rx_michael_mic_report(local->mdev, hdr, sta, &rx);
		goto end;
	}

	if (unlikely(local->sta_scanning))
		rx.u.rx.in_scan = 1;

	if (__ieee80211_invoke_rx_handlers(local, local->rx_pre_handlers, &rx,
					   sta) != TXRX_CONTINUE)
		goto end;
	skb = rx.skb;

	skb_push(skb, radiotap_len);
	if (sta && !sta->assoc_ap && !(sta->flags & WLAN_STA_WDS) &&
1368
	    !local->iff_promiscs && !is_multicast_ether_addr(hdr->addr1)) {
1369 1370
		rx.u.rx.ra_match = 1;
		ieee80211_invoke_rx_handlers(local, local->rx_handlers, &rx,
1371
					     rx.sta);
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		sta_info_put(sta);
		return;
	}

	bssid = ieee80211_get_bssid(hdr, skb->len - radiotap_len);

	read_lock(&local->sub_if_lock);
	list_for_each_entry(sdata, &local->sub_if_list, list) {
		rx.u.rx.ra_match = 1;
1381 1382 1383 1384 1385 1386 1387

		prepres = prepare_for_handlers(sdata, bssid, &rx, hdr);
		/* prepare_for_handlers can change sta */
		sta = rx.sta;

		if (!prepres)
			continue;
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1389
		if (prev) {
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			skb_new = skb_copy(skb, GFP_ATOMIC);
			if (!skb_new) {
				if (net_ratelimit())
					printk(KERN_DEBUG "%s: failed to copy "
					       "multicast frame for %s",
					       local->mdev->name, prev->dev->name);
				continue;
			}
			rx.skb = skb_new;
1399 1400 1401 1402
			rx.dev = prev->dev;
			rx.sdata = prev;
			ieee80211_invoke_rx_handlers(local, local->rx_handlers,
						     &rx, sta);
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1403 1404
		}
		prev = sdata;
1405
	}
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	if (prev) {
		rx.skb = skb;
		rx.dev = prev->dev;
		rx.sdata = prev;
		ieee80211_invoke_rx_handlers(local, local->rx_handlers,
					     &rx, sta);
	} else
		dev_kfree_skb(skb);
	read_unlock(&local->sub_if_lock);
1415

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 end:
1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438
	if (sta)
		sta_info_put(sta);
}
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_rx_status *status)
{
	struct ieee80211_local *local = hw_to_local(hw);

	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));

	skb->dev = local->mdev;
	/* copy status into skb->cb for use by tasklet */
	memcpy(skb->cb, status, sizeof(*status));
	skb->pkt_type = IEEE80211_RX_MSG;
	skb_queue_tail(&local->skb_queue, skb);
	tasklet_schedule(&local->tasklet);
}
EXPORT_SYMBOL(ieee80211_rx_irqsafe);