rx.c 43.2 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 "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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 * 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 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;
	}

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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 ((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;
	}

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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;
		}

		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;
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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?
		 */
		if (!(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV))
			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++;
		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++;
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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
		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 */
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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;
	}

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

	sta->rx_fragments++;
	sta->rx_bytes += rx->skb->len;
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	sta->last_rssi = rx->u.rx.status->ssi;
	sta->last_signal = rx->u.rx.status->signal;
	sta->last_noise = rx->u.rx.status->noise;
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	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 ||
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	    !rx->key || rx->key->conf.alg != ALG_WEP ||
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	    !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
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		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) ||
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	    !(rx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
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		if (ieee80211_wep_is_weak_iv(rx->skb, rx->key))
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			rx->sta->wep_weak_iv_count++;

	return TXRX_CONTINUE;
}

static ieee80211_txrx_result
ieee80211_rx_h_wep_decrypt(struct ieee80211_txrx_data *rx)
{
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	if ((rx->key && rx->key->conf.alg != ALG_WEP) ||
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	    !(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) {
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		if (net_ratelimit())
			printk(KERN_DEBUG "%s: RX WEP frame, but no key set\n",
			       rx->dev->name);
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		return TXRX_DROP;
	}

	if (!(rx->u.rx.status->flag & RX_FLAG_DECRYPTED) ||
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	    !(rx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) {
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		if (ieee80211_wep_decrypt(rx->local, rx->skb, rx->key)) {
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			if (net_ratelimit())
				printk(KERN_DEBUG "%s: RX WEP frame, decrypt "
				       "failed\n", rx->dev->name);
568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686
			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));
687
		if (rx->key && rx->key->conf.alg == ALG_CCMP &&
688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713
		    (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;
714
		if (!rx->key || rx->key->conf.alg != ALG_CCMP)
715 716 717 718 719 720 721 722 723
			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) {
724 725 726 727 728 729 730 731 732
			if (net_ratelimit())
				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]);
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
			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 */
763
	rx->flags |= IEEE80211_TXRXD_FRAGMENTED;
764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783

 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 ||
784
		   !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)))
785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843
		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;
}

844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863
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;
}

864 865 866 867
static ieee80211_txrx_result
ieee80211_rx_h_802_1x_pae(struct ieee80211_txrx_data *rx)
{
	if (rx->sdata->eapol && ieee80211_is_eapol(rx->skb) &&
868 869
	    rx->sdata->type != IEEE80211_IF_TYPE_STA &&
	    (rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899
		/* 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)
{
900 901 902 903 904 905 906
	/*
	 * Pass through unencrypted frames if the hardware might have
	 * decrypted them already without telling us, but that can only
	 * be true if we either didn't find a key or the found key is
	 * uploaded to the hardware.
	 */
	if ((rx->local->hw.flags & IEEE80211_HW_DEVICE_HIDES_WEP) &&
J
Johannes Berg 已提交
907
	    (!rx->key || (rx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)))
908 909 910 911 912 913 914 915 916
		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)))) {
917 918 919
		if (net_ratelimit())
			printk(KERN_DEBUG "%s: RX non-WEP frame, but expected "
			       "encryption\n", rx->dev->name);
920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964
		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)) {
965 966 967 968 969 970 971 972 973
			if (net_ratelimit())
				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));
974 975 976 977 978 979 980 981 982
			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)) {
983 984 985 986 987 988 989 990 991 992
			if (net_ratelimit())
				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));
993 994 995 996 997 998 999 1000
			return TXRX_DROP;
		}
		break;
	case IEEE80211_FCTL_FROMDS:
		/* DA BSSID SA */
		memcpy(dst, hdr->addr1, ETH_ALEN);
		memcpy(src, hdr->addr3, ETH_ALEN);

1001 1002 1003
		if (sdata->type != IEEE80211_IF_TYPE_STA ||
		    (is_multicast_ether_addr(dst) &&
		     !compare_ether_addr(src, dev->dev_addr)))
1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062
			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
1063 1064
	    || sdata->type == IEEE80211_IF_TYPE_VLAN) &&
	    (rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
1065 1066 1067 1068
		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);
1069
			if (!skb2 && net_ratelimit())
1070 1071 1072 1073 1074 1075
				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) {
1076 1077 1078
				if (net_ratelimit())
					printk(KERN_DEBUG "Station with null "
					       "dev structure!\n");
1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114
			} 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;

1115
	if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143
		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);
1155 1156
			break;
		}
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		break;
1158 1159
	}

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1160
	if (res == TXRX_DROP)
1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189
		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). */
1190 1191 1192 1193 1194
	if (net_ratelimit())
		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);
1195 1196 1197 1198 1199

	if (!sta) {
		/* Some hardware versions seem to generate incorrect
		 * Michael MIC reports; ignore them to avoid triggering
		 * countermeasures. */
1200 1201 1202 1203
		if (net_ratelimit())
			printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
			       "error for unknown address " MAC_FMT "\n",
			       dev->name, MAC_ARG(hdr->addr2));
1204 1205 1206 1207
		goto ignore;
	}

	if (!(rx->fc & IEEE80211_FCTL_PROTECTED)) {
1208 1209 1210 1211
		if (net_ratelimit())
			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));
1212 1213 1214 1215
		goto ignore;
	}

	if ((rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) &&
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	    rx->sdata->type == IEEE80211_IF_TYPE_AP && keyidx) {
1217 1218 1219 1220
		/* 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. */
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		if (net_ratelimit())
			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;
1227 1228 1229 1230 1231
	}

	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)) {
1232 1233 1234 1235 1236
		if (net_ratelimit())
			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));
1237 1238 1239 1240 1241 1242 1243
		goto ignore;
	}

	/* TODO: consider verifying the MIC error report with software
	 * implementation if we get too many spurious reports from the
	 * hardware. */

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	mac80211_ev_michael_mic_failure(rx->dev, keyidx, hdr);
1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255
 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,
1256
	ieee80211_rx_h_load_key,
1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278
	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 */

1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289
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)) {
1290
			if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1291
				return 0;
1292
			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1293 1294 1295
		} else if (!multicast &&
			   compare_ether_addr(sdata->dev->dev_addr,
					      hdr->addr1) != 0) {
1296
			if (!(sdata->flags & IEEE80211_SDATA_PROMISC))
1297
				return 0;
1298
			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1299 1300 1301 1302 1303 1304
		}
		break;
	case IEEE80211_IF_TYPE_IBSS:
		if (!bssid)
			return 0;
		if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1305
			if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1306
				return 0;
1307
			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1308 1309 1310
		} else if (!multicast &&
			   compare_ether_addr(sdata->dev->dev_addr,
					      hdr->addr1) != 0) {
1311
			if (!(sdata->flags & IEEE80211_SDATA_PROMISC))
1312
				return 0;
1313
			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324
		} 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)) {
1325
			if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1326
				return 0;
1327
			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1328
		}
1329 1330
		if (sdata->dev == sdata->local->mdev &&
		    !(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346
			/* 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;
}

1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359
/*
 * 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;
1360
	int radiotap_len = 0, prepres;
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	struct ieee80211_sub_if_data *prev = NULL;
	struct sk_buff *skb_new;
	u8 *bssid;
1364 1365 1366 1367 1368 1369

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

1370 1371 1372 1373 1374 1375
	/*
	 * key references are protected using RCU and this requires that
	 * we are in a read-site RCU section during receive processing
	 */
	rcu_read_lock();

1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386
	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++;

1387
	if (skb->len >= 16) {
1388
		sta = rx.sta = sta_info_get(local, hdr->addr2);
1389 1390 1391 1392 1393
		if (sta) {
			rx.dev = rx.sta->dev;
			rx.sdata = IEEE80211_DEV_TO_SUB_IF(rx.dev);
		}
	} else
1394 1395 1396 1397 1398 1399 1400 1401
		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))
1402
		rx.flags |= IEEE80211_TXRXD_RXIN_SCAN;
1403 1404 1405 1406 1407 1408 1409

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

	skb_push(skb, radiotap_len);
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	if (sta && !(sta->flags & (WLAN_STA_WDS | WLAN_STA_ASSOC_AP)) &&
1411
	    !local->iff_promiscs && !is_multicast_ether_addr(hdr->addr1)) {
1412
		rx.flags |= IEEE80211_TXRXD_RXRA_MATCH;
1413
		ieee80211_invoke_rx_handlers(local, local->rx_handlers, &rx,
1414
					     rx.sta);
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1415
		sta_info_put(sta);
1416
		rcu_read_unlock();
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1417 1418 1419 1420 1421 1422 1423
		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) {
1424
		rx.flags |= IEEE80211_TXRXD_RXRA_MATCH;
1425

1426 1427 1428
		if (!netif_running(sdata->dev))
			continue;

1429 1430 1431 1432 1433 1434
		prepres = prepare_for_handlers(sdata, bssid, &rx, hdr);
		/* prepare_for_handlers can change sta */
		sta = rx.sta;

		if (!prepres)
			continue;
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1436 1437 1438 1439 1440 1441 1442 1443 1444
		/*
		 * frame is destined for this interface, but if it's not
		 * also for the previous one we handle that after the
		 * loop to avoid copying the SKB once too much
		 */

		if (!prev) {
			prev = sdata;
			continue;
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1445
		}
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1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464

		/*
		 * frame was destined for the previous interface
		 * so invoke RX handlers for it
		 */

		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;
		rx.dev = prev->dev;
		rx.sdata = prev;
		ieee80211_invoke_rx_handlers(local, local->rx_handlers,
					     &rx, sta);
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1465
		prev = sdata;
1466
	}
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1467 1468 1469 1470 1471 1472 1473 1474 1475
	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);
1476

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1477
 end:
1478 1479
	rcu_read_unlock();

1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501
	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);