tx.c 61.6 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.
 *
 *
 * Transmit and frame generation functions.
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/bitmap.h>
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#include <linux/rcupdate.h>
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#include <net/net_namespace.h>
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#include <net/ieee80211_radiotap.h>
#include <net/cfg80211.h>
#include <net/mac80211.h>
#include <asm/unaligned.h>

#include "ieee80211_i.h"
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#include "driver-ops.h"
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#include "led.h"
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#include "mesh.h"
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#include "wep.h"
#include "wpa.h"
#include "wme.h"
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#include "rate.h"
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#define IEEE80211_TX_OK		0
#define IEEE80211_TX_AGAIN	1
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#define IEEE80211_TX_PENDING	2
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/* misc utils */

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

	/* assume HW handles this */
	if (info->control.rates[0].flags & IEEE80211_TX_RC_MCS)
		return 0;

	/* uh huh? */
	if (WARN_ON_ONCE(info->control.rates[0].idx < 0))
		return 0;
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	sband = local->hw.wiphy->bands[tx->channel->band];
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	txrate = &sband->bitrates[info->control.rates[0].idx];
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	erp = txrate->flags & IEEE80211_RATE_ERP_G;
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	/*
	 * data and mgmt (except PS Poll):
	 * - during CFP: 32768
	 * - during contention period:
	 *   if addr1 is group address: 0
	 *   if more fragments = 0 and addr1 is individual address: time to
	 *      transmit one ACK plus SIFS
	 *   if more fragments = 1 and addr1 is individual address: time to
	 *      transmit next fragment plus 2 x ACK plus 3 x SIFS
	 *
	 * IEEE 802.11, 9.6:
	 * - control response frame (CTS or ACK) shall be transmitted using the
	 *   same rate as the immediately previous frame in the frame exchange
	 *   sequence, if this rate belongs to the PHY mandatory rates, or else
	 *   at the highest possible rate belonging to the PHY rates in the
	 *   BSSBasicRateSet
	 */
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	hdr = (struct ieee80211_hdr *)tx->skb->data;
	if (ieee80211_is_ctl(hdr->frame_control)) {
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		/* TODO: These control frames are not currently sent by
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		 * mac80211, but should they be implemented, this function
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		 * needs to be updated to support duration field calculation.
		 *
		 * RTS: time needed to transmit pending data/mgmt frame plus
		 *    one CTS frame plus one ACK frame plus 3 x SIFS
		 * CTS: duration of immediately previous RTS minus time
		 *    required to transmit CTS and its SIFS
		 * ACK: 0 if immediately previous directed data/mgmt had
		 *    more=0, with more=1 duration in ACK frame is duration
		 *    from previous frame minus time needed to transmit ACK
		 *    and its SIFS
		 * PS Poll: BIT(15) | BIT(14) | aid
		 */
		return 0;
	}

	/* data/mgmt */
	if (0 /* FIX: data/mgmt during CFP */)
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		return cpu_to_le16(32768);
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	if (group_addr) /* Group address as the destination - no ACK */
		return 0;

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

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

	/* Time needed to transmit ACK
	 * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
	 * to closest integer */

	dur = ieee80211_frame_duration(local, 10, rate, erp,
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				tx->sdata->vif.bss_conf.use_short_preamble);
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	if (next_frag_len) {
		/* Frame is fragmented: duration increases with time needed to
		 * transmit next fragment plus ACK and 2 x SIFS. */
		dur *= 2; /* ACK + SIFS */
		/* next fragment */
		dur += ieee80211_frame_duration(local, next_frag_len,
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				txrate->bitrate, erp,
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				tx->sdata->vif.bss_conf.use_short_preamble);
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	}

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	return cpu_to_le16(dur);
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}

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static int inline is_ieee80211_device(struct ieee80211_local *local,
				      struct net_device *dev)
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{
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	return local == wdev_priv(dev->ieee80211_ptr);
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}

/* tx handlers */

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static ieee80211_tx_result debug_noinline
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ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
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{
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	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
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	u32 sta_flags;

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	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
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		return TX_CONTINUE;
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	if (unlikely(tx->local->sw_scanning) &&
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	    !ieee80211_is_probe_req(hdr->frame_control) &&
	    !ieee80211_is_nullfunc(hdr->frame_control))
		/*
		 * When software scanning only nullfunc frames (to notify
		 * the sleep state to the AP) and probe requests (for the
		 * active scan) are allowed, all other frames should not be
		 * sent and we should not get here, but if we do
		 * nonetheless, drop them to avoid sending them
		 * off-channel. See the link below and
		 * ieee80211_start_scan() for more.
		 *
		 * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089
		 */
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		return TX_DROP;
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	if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
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		return TX_CONTINUE;

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	if (tx->flags & IEEE80211_TX_PS_BUFFERED)
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		return TX_CONTINUE;
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	sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;
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	if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
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		if (unlikely(!(sta_flags & WLAN_STA_ASSOC) &&
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			     tx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
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			     ieee80211_is_data(hdr->frame_control))) {
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#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
			printk(KERN_DEBUG "%s: dropped data frame to not "
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			       "associated station %pM\n",
			       tx->dev->name, hdr->addr1);
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#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
			I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
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			return TX_DROP;
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		}
	} else {
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		if (unlikely(ieee80211_is_data(hdr->frame_control) &&
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			     tx->local->num_sta == 0 &&
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			     tx->sdata->vif.type != NL80211_IFTYPE_ADHOC)) {
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			/*
			 * No associated STAs - no need to send multicast
			 * frames.
			 */
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			return TX_DROP;
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		}
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		return TX_CONTINUE;
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	}

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	return TX_CONTINUE;
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}

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

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	/*
	 * virtual interfaces are protected by RCU
	 */
	rcu_read_lock();

	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
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		struct ieee80211_if_ap *ap;
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		if (sdata->vif.type != NL80211_IFTYPE_AP)
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			continue;
		ap = &sdata->u.ap;
		skb = skb_dequeue(&ap->ps_bc_buf);
		if (skb) {
			purged++;
			dev_kfree_skb(skb);
		}
		total += skb_queue_len(&ap->ps_bc_buf);
	}

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	list_for_each_entry_rcu(sta, &local->sta_list, list) {
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		skb = skb_dequeue(&sta->ps_tx_buf);
		if (skb) {
			purged++;
			dev_kfree_skb(skb);
		}
		total += skb_queue_len(&sta->ps_tx_buf);
	}
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	rcu_read_unlock();
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	local->total_ps_buffered = total;
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#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
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	printk(KERN_DEBUG "%s: PS buffers full - purged %d frames\n",
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	       wiphy_name(local->hw.wiphy), purged);
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#endif
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}

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static ieee80211_tx_result
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ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
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{
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	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
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	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
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	/*
	 * broadcast/multicast frame
	 *
	 * If any of the associated stations is in power save mode,
	 * the frame is buffered to be sent after DTIM beacon frame.
	 * This is done either by the hardware or us.
	 */

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	/* powersaving STAs only in AP/VLAN mode */
	if (!tx->sdata->bss)
		return TX_CONTINUE;

	/* no buffering for ordered frames */
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	if (ieee80211_has_order(hdr->frame_control))
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		return TX_CONTINUE;
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	/* no stations in PS mode */
	if (!atomic_read(&tx->sdata->bss->num_sta_ps))
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		return TX_CONTINUE;
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	/* buffered in mac80211 */
	if (tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING) {
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		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
			purge_old_ps_buffers(tx->local);
		if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >=
		    AP_MAX_BC_BUFFER) {
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#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
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			if (net_ratelimit()) {
				printk(KERN_DEBUG "%s: BC TX buffer full - "
				       "dropping the oldest frame\n",
				       tx->dev->name);
			}
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#endif
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			dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
		} else
			tx->local->total_ps_buffered++;
		skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
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		return TX_QUEUED;
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	}

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	/* buffered in hardware */
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	info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
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	return TX_CONTINUE;
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}

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

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

	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *)
					    skb->data))
		return 0;

	return 1;
}

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static ieee80211_tx_result
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ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
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{
	struct sta_info *sta = tx->sta;
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	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
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	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
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	u32 staflags;
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	if (unlikely(!sta || ieee80211_is_probe_resp(hdr->frame_control)))
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		return TX_CONTINUE;
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	staflags = get_sta_flags(sta);

	if (unlikely((staflags & WLAN_STA_PS) &&
		     !(staflags & WLAN_STA_PSPOLL))) {
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#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
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		printk(KERN_DEBUG "STA %pM aid %d: PS buffer (entries "
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		       "before %d)\n",
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		       sta->sta.addr, sta->sta.aid,
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		       skb_queue_len(&sta->ps_tx_buf));
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
			purge_old_ps_buffers(tx->local);
		if (skb_queue_len(&sta->ps_tx_buf) >= STA_MAX_TX_BUFFER) {
			struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf);
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#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
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			if (net_ratelimit()) {
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				printk(KERN_DEBUG "%s: STA %pM TX "
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				       "buffer full - dropping oldest frame\n",
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				       tx->dev->name, sta->sta.addr);
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			}
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#endif
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			dev_kfree_skb(old);
		} else
			tx->local->total_ps_buffered++;
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		/* Queue frame to be sent after STA sends an PS Poll frame */
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		if (skb_queue_empty(&sta->ps_tx_buf))
			sta_info_set_tim_bit(sta);

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		info->control.jiffies = jiffies;
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		info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
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		skb_queue_tail(&sta->ps_tx_buf, tx->skb);
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		return TX_QUEUED;
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	}
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
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	else if (unlikely(test_sta_flags(sta, WLAN_STA_PS))) {
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		printk(KERN_DEBUG "%s: STA %pM in PS mode, but pspoll "
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		       "set -> send frame\n", tx->dev->name,
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		       sta->sta.addr);
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	}
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
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	if (test_and_clear_sta_flags(sta, WLAN_STA_PSPOLL)) {
		/*
		 * The sleeping station with pending data is now snoozing.
		 * It queried us for its buffered frames and will go back
		 * to deep sleep once it got everything.
		 *
		 * inform the driver, in case the hardware does powersave
		 * frame filtering and keeps a station  blacklist on its own
		 * (e.g: p54), so that frames can be delivered unimpeded.
		 *
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		 * Note: It should be safe to disable the filter now.
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		 * As, it is really unlikely that we still have any pending
		 * frame for this station in the hw's buffers/fifos left,
		 * that is not rejected with a unsuccessful tx_status yet.
		 */
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		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
	}
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	return TX_CONTINUE;
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}

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static ieee80211_tx_result debug_noinline
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ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
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{
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	if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
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		return TX_CONTINUE;
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	if (tx->flags & IEEE80211_TX_UNICAST)
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		return ieee80211_tx_h_unicast_ps_buf(tx);
	else
		return ieee80211_tx_h_multicast_ps_buf(tx);
}

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static ieee80211_tx_result debug_noinline
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ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
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{
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	struct ieee80211_key *key = NULL;
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	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
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	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
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	if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT))
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		tx->key = NULL;
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	else if (tx->sta && (key = rcu_dereference(tx->sta->key)))
		tx->key = key;
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	else if (ieee80211_is_mgmt(hdr->frame_control) &&
		 (key = rcu_dereference(tx->sdata->default_mgmt_key)))
		tx->key = key;
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	else if ((key = rcu_dereference(tx->sdata->default_key)))
		tx->key = key;
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	else if (tx->sdata->drop_unencrypted &&
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		 (tx->skb->protocol != cpu_to_be16(ETH_P_PAE)) &&
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		 !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
		 (!ieee80211_is_robust_mgmt_frame(hdr) ||
		  (ieee80211_is_action(hdr->frame_control) &&
		   tx->sta && test_sta_flags(tx->sta, WLAN_STA_MFP)))) {
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		I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
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		return TX_DROP;
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	} else
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		tx->key = NULL;

	if (tx->key) {
		tx->key->tx_rx_count++;
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		/* TODO: add threshold stuff again */
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		switch (tx->key->conf.alg) {
		case ALG_WEP:
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			if (ieee80211_is_auth(hdr->frame_control))
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				break;
		case ALG_TKIP:
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			if (!ieee80211_is_data_present(hdr->frame_control))
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				tx->key = NULL;
			break;
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		case ALG_CCMP:
			if (!ieee80211_is_data_present(hdr->frame_control) &&
			    !ieee80211_use_mfp(hdr->frame_control, tx->sta,
					       tx->skb))
				tx->key = NULL;
			break;
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		case ALG_AES_CMAC:
			if (!ieee80211_is_mgmt(hdr->frame_control))
				tx->key = NULL;
			break;
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		}
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	}

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	if (!tx->key || !(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
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		info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
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	return TX_CONTINUE;
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}

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static ieee80211_tx_result debug_noinline
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ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
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{
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	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
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	struct ieee80211_hdr *hdr = (void *)tx->skb->data;
	struct ieee80211_supported_band *sband;
	struct ieee80211_rate *rate;
	int i, len;
	bool inval = false, rts = false, short_preamble = false;
	struct ieee80211_tx_rate_control txrc;
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	u32 sta_flags;
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	memset(&txrc, 0, sizeof(txrc));
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	sband = tx->local->hw.wiphy->bands[tx->channel->band];
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	len = min_t(int, tx->skb->len + FCS_LEN,
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			 tx->local->hw.wiphy->frag_threshold);
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	/* set up the tx rate control struct we give the RC algo */
	txrc.hw = local_to_hw(tx->local);
	txrc.sband = sband;
	txrc.bss_conf = &tx->sdata->vif.bss_conf;
	txrc.skb = tx->skb;
	txrc.reported_rate.idx = -1;
	txrc.max_rate_idx = tx->sdata->max_ratectrl_rateidx;

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

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	/*
	 * Use short preamble if the BSS can handle it, but not for
	 * management frames unless we know the receiver can handle
	 * that -- the management frame might be to a station that
	 * just wants a probe response.
	 */
	if (tx->sdata->vif.bss_conf.use_short_preamble &&
	    (ieee80211_is_data(hdr->frame_control) ||
	     (tx->sta && test_sta_flags(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
		txrc.short_preamble = short_preamble = true;
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	sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;

	/*
	 * Lets not bother rate control if we're associated and cannot
	 * talk to the sta. This should not happen.
	 */
	if (WARN((tx->local->sw_scanning) &&
		 (sta_flags & WLAN_STA_ASSOC) &&
		 !rate_usable_index_exists(sband, &tx->sta->sta),
		 "%s: Dropped data frame as no usable bitrate found while "
		 "scanning and associated. Target station: "
		 "%pM on %d GHz band\n",
		 tx->dev->name, hdr->addr1,
		 tx->channel->band ? 5 : 2))
		return TX_DROP;
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	/*
	 * If we're associated with the sta at this point we know we can at
	 * least send the frame at the lowest bit rate.
	 */
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	rate_control_get_rate(tx->sdata, tx->sta, &txrc);

	if (unlikely(info->control.rates[0].idx < 0))
		return TX_DROP;

	if (txrc.reported_rate.idx < 0)
		txrc.reported_rate = info->control.rates[0];
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	if (tx->sta)
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		tx->sta->last_tx_rate = txrc.reported_rate;
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	if (unlikely(!info->control.rates[0].count))
		info->control.rates[0].count = 1;
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	if (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
			 (info->flags & IEEE80211_TX_CTL_NO_ACK)))
		info->control.rates[0].count = 1;

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	if (is_multicast_ether_addr(hdr->addr1)) {
		/*
		 * XXX: verify the rate is in the basic rateset
		 */
		return TX_CONTINUE;
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	}

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	/*
	 * set up the RTS/CTS rate as the fastest basic rate
	 * that is not faster than the data rate
	 *
	 * XXX: Should this check all retry rates?
	 */
	if (!(info->control.rates[0].flags & IEEE80211_TX_RC_MCS)) {
		s8 baserate = 0;

		rate = &sband->bitrates[info->control.rates[0].idx];

		for (i = 0; i < sband->n_bitrates; i++) {
			/* must be a basic rate */
			if (!(tx->sdata->vif.bss_conf.basic_rates & BIT(i)))
				continue;
			/* must not be faster than the data rate */
			if (sband->bitrates[i].bitrate > rate->bitrate)
				continue;
			/* maximum */
			if (sband->bitrates[baserate].bitrate <
			     sband->bitrates[i].bitrate)
				baserate = i;
		}

		info->control.rts_cts_rate_idx = baserate;
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	}

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	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
		/*
		 * make sure there's no valid rate following
		 * an invalid one, just in case drivers don't
		 * take the API seriously to stop at -1.
		 */
		if (inval) {
			info->control.rates[i].idx = -1;
			continue;
		}
		if (info->control.rates[i].idx < 0) {
			inval = true;
			continue;
		}
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		/*
		 * For now assume MCS is already set up correctly, this
		 * needs to be fixed.
		 */
		if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) {
			WARN_ON(info->control.rates[i].idx > 76);
			continue;
		}
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		/* set up RTS protection if desired */
		if (rts)
			info->control.rates[i].flags |=
				IEEE80211_TX_RC_USE_RTS_CTS;
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		/* RC is busted */
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		if (WARN_ON_ONCE(info->control.rates[i].idx >=
				 sband->n_bitrates)) {
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			info->control.rates[i].idx = -1;
			continue;
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		}
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		rate = &sband->bitrates[info->control.rates[i].idx];

		/* set up short preamble */
		if (short_preamble &&
		    rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
			info->control.rates[i].flags |=
				IEEE80211_TX_RC_USE_SHORT_PREAMBLE;

		/* set up G protection */
		if (!rts && tx->sdata->vif.bss_conf.use_cts_prot &&
		    rate->flags & IEEE80211_RATE_ERP_G)
			info->control.rates[i].flags |=
				IEEE80211_TX_RC_USE_CTS_PROTECT;
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	}

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	return TX_CONTINUE;
}

static ieee80211_tx_result debug_noinline
ieee80211_tx_h_misc(struct ieee80211_tx_data *tx)
{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);

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	if (tx->sta)
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		info->control.sta = &tx->sta->sta;
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	return TX_CONTINUE;
}

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static ieee80211_tx_result debug_noinline
ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
	u16 *seq;
	u8 *qc;
	int tid;

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

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

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

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	/*
	 * Anything but QoS data that has a sequence number field
	 * (is long enough) gets a sequence number from the global
	 * counter.
	 */
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	if (!ieee80211_is_data_qos(hdr->frame_control)) {
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		/* driver should assign sequence number */
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		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
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		/* for pure STA mode without beacons, we can do it */
		hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
		tx->sdata->sequence_number += 0x10;
		tx->sdata->sequence_number &= IEEE80211_SCTL_SEQ;
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		return TX_CONTINUE;
	}

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

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

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

	hdr->seq_ctrl = cpu_to_le16(*seq);

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

	return TX_CONTINUE;
}

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

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

	while (rem) {
		int fraglen = per_fragm;

		if (fraglen > rem)
			fraglen = rem;
		rem -= fraglen;
		tmp = dev_alloc_skb(local->tx_headroom +
				    frag_threshold +
				    IEEE80211_ENCRYPT_HEADROOM +
				    IEEE80211_ENCRYPT_TAILROOM);
		if (!tmp)
			return -ENOMEM;
		tail->next = tmp;
		tail = tmp;
		skb_reserve(tmp, local->tx_headroom +
				 IEEE80211_ENCRYPT_HEADROOM);
		/* copy control information */
		memcpy(tmp->cb, skb->cb, sizeof(tmp->cb));
		skb_copy_queue_mapping(tmp, skb);
		tmp->priority = skb->priority;
		tmp->dev = skb->dev;

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

		pos += fraglen;
	}

	skb->len = hdrlen + per_fragm;
	return 0;
}

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static ieee80211_tx_result debug_noinline
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ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
{
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	struct sk_buff *skb = tx->skb;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ieee80211_hdr *hdr = (void *)skb->data;
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	int frag_threshold = tx->local->hw.wiphy->frag_threshold;
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	int hdrlen;
	int fragnum;
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	if (!(tx->flags & IEEE80211_TX_FRAGMENTED))
		return TX_CONTINUE;

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

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	hdrlen = ieee80211_hdrlen(hdr->frame_control);
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	/* internal error, why is TX_FRAGMENTED set? */
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	if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
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		return TX_DROP;
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	/*
	 * Now fragment the frame. This will allocate all the fragments and
	 * chain them (using skb as the first fragment) to skb->next.
	 * During transmission, we will remove the successfully transmitted
	 * fragments from this list. When the low-level driver rejects one
	 * of the fragments then we will simply pretend to accept the skb
	 * but store it away as pending.
	 */
	if (ieee80211_fragment(tx->local, skb, hdrlen, frag_threshold))
		return TX_DROP;
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	/* update duration/seq/flags of fragments */
	fragnum = 0;
	do {
		int next_len;
		const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
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		hdr = (void *)skb->data;
		info = IEEE80211_SKB_CB(skb);
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		if (skb->next) {
			hdr->frame_control |= morefrags;
			next_len = skb->next->len;
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			/*
			 * No multi-rate retries for fragmented frames, that
			 * would completely throw off the NAV at other STAs.
			 */
			info->control.rates[1].idx = -1;
			info->control.rates[2].idx = -1;
			info->control.rates[3].idx = -1;
			info->control.rates[4].idx = -1;
			BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
			info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
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		} else {
			hdr->frame_control &= ~morefrags;
			next_len = 0;
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		}
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		hdr->duration_id = ieee80211_duration(tx, 0, next_len);
		hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
		fragnum++;
	} while ((skb = skb->next));
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859
	return TX_CONTINUE;
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}

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

	switch (tx->key->conf.alg) {
	case ALG_WEP:
		return ieee80211_crypto_wep_encrypt(tx);
	case ALG_TKIP:
		return ieee80211_crypto_tkip_encrypt(tx);
	case ALG_CCMP:
		return ieee80211_crypto_ccmp_encrypt(tx);
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	case ALG_AES_CMAC:
		return ieee80211_crypto_aes_cmac_encrypt(tx);
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	}

	/* not reached */
	WARN_ON(1);
	return TX_DROP;
}

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static ieee80211_tx_result debug_noinline
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ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
{
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	struct sk_buff *skb = tx->skb;
	struct ieee80211_hdr *hdr;
	int next_len;
	bool group_addr;
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	do {
		hdr = (void *) skb->data;
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		if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
			break; /* must not overwrite AID */
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		next_len = skb->next ? skb->next->len : 0;
		group_addr = is_multicast_ether_addr(hdr->addr1);
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		hdr->duration_id =
			ieee80211_duration(tx, group_addr, next_len);
	} while ((skb = skb->next));
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	return TX_CONTINUE;
}

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static ieee80211_tx_result debug_noinline
907
ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
908
{
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	struct sk_buff *skb = tx->skb;
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	if (!tx->sta)
		return TX_CONTINUE;
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	tx->sta->tx_packets++;
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	do {
		tx->sta->tx_fragments++;
		tx->sta->tx_bytes += skb->len;
	} while ((skb = skb->next));
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	return TX_CONTINUE;
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}

/* actual transmit path */

/*
 * deal with packet injection down monitor interface
 * with Radiotap Header -- only called for monitor mode interface
 */
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static bool __ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
					  struct sk_buff *skb)
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{
	/*
	 * this is the moment to interpret and discard the radiotap header that
	 * must be at the start of the packet injected in Monitor mode
	 *
	 * Need to take some care with endian-ness since radiotap
	 * args are little-endian
	 */

	struct ieee80211_radiotap_iterator iterator;
	struct ieee80211_radiotap_header *rthdr =
		(struct ieee80211_radiotap_header *) skb->data;
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	struct ieee80211_supported_band *sband;
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	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
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	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len);

947
	sband = tx->local->hw.wiphy->bands[tx->channel->band];
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949
	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
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	tx->flags &= ~IEEE80211_TX_FRAGMENTED;
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	/*
	 * for every radiotap entry that is present
	 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
	 * entries present, or -EINVAL on error)
	 */

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

		if (ret)
			continue;

		/* see if this argument is something we can use */
		switch (iterator.this_arg_index) {
		/*
		 * You must take care when dereferencing iterator.this_arg
		 * for multibyte types... the pointer is not aligned.  Use
		 * get_unaligned((type *)iterator.this_arg) to dereference
		 * iterator.this_arg for type "type" safely on all arches.
		*/
		case IEEE80211_RADIOTAP_FLAGS:
			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
				/*
				 * this indicates that the skb we have been
				 * handed has the 32-bit FCS CRC at the end...
				 * we should react to that by snipping it off
				 * because it will be recomputed and added
				 * on transmission
				 */
				if (skb->len < (iterator.max_length + FCS_LEN))
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					return false;
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				skb_trim(skb, skb->len - FCS_LEN);
			}
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			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
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				info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
988
			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
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				tx->flags |= IEEE80211_TX_FRAGMENTED;
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			break;

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

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		default:
			break;
		}
	}

	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
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		return false;
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	/*
	 * remove the radiotap header
	 * iterator->max_length was sanity-checked against
	 * skb->len by iterator init
	 */
	skb_pull(skb, iterator.max_length);

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	return true;
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}

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/*
 * initialises @tx
 */
1019
static ieee80211_tx_result
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ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
		     struct ieee80211_tx_data *tx,
		     struct sk_buff *skb)
1023
{
1024
	struct ieee80211_local *local = sdata->local;
1025
	struct ieee80211_hdr *hdr;
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	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
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	int hdrlen, tid;
	u8 *qc, *state;
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	bool queued = false;
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	memset(tx, 0, sizeof(*tx));
	tx->skb = skb;
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	tx->dev = sdata->dev; /* use original interface */
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	tx->local = local;
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	tx->sdata = sdata;
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	tx->channel = local->hw.conf.channel;
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	/*
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	 * Set this flag (used below to indicate "automatic fragmentation"),
	 * it will be cleared/left by radiotap as desired.
1040
	 */
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	tx->flags |= IEEE80211_TX_FRAGMENTED;
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	/* process and remove the injection radiotap header */
1044
	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED)) {
1045
		if (!__ieee80211_parse_tx_radiotap(tx, skb))
1046
			return TX_DROP;
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1048
		/*
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		 * __ieee80211_parse_tx_radiotap has now removed
		 * the radiotap header that was present and pre-filled
		 * 'tx' with tx control information.
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		 */
	}

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

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

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	tx->sta = sta_info_get(local, hdr->addr1);
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	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)) {
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		unsigned long flags;
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		struct tid_ampdu_tx *tid_tx;

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

1074
		spin_lock_irqsave(&tx->sta->lock, flags);
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		/*
		 * XXX: This spinlock could be fairly expensive, but see the
		 *	comment in agg-tx.c:ieee80211_agg_tx_operational().
		 *	One way to solve this would be to do something RCU-like
		 *	for managing the tid_tx struct and using atomic bitops
		 *	for the actual state -- by introducing an actual
		 *	'operational' bit that would be possible. It would
		 *	require changing ieee80211_agg_tx_operational() to
		 *	set that bit, and changing the way tid_tx is managed
		 *	everywhere, including races between that bit and
		 *	tid_tx going away (tid_tx being added can be easily
		 *	committed to memory before the 'operational' bit).
		 */
		tid_tx = tx->sta->ampdu_mlme.tid_tx[tid];
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		state = &tx->sta->ampdu_mlme.tid_state_tx[tid];
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		if (*state == HT_AGG_STATE_OPERATIONAL) {
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			info->flags |= IEEE80211_TX_CTL_AMPDU;
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		} else if (*state != HT_AGG_STATE_IDLE) {
			/* in progress */
			queued = true;
			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
			__skb_queue_tail(&tid_tx->pending, skb);
		}
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		spin_unlock_irqrestore(&tx->sta->lock, flags);
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		if (unlikely(queued))
			return TX_QUEUED;
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	}

1104
	if (is_multicast_ether_addr(hdr->addr1)) {
1105
		tx->flags &= ~IEEE80211_TX_UNICAST;
1106
		info->flags |= IEEE80211_TX_CTL_NO_ACK;
1107
	} else {
1108
		tx->flags |= IEEE80211_TX_UNICAST;
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		if (unlikely(local->wifi_wme_noack_test))
			info->flags |= IEEE80211_TX_CTL_NO_ACK;
		else
			info->flags &= ~IEEE80211_TX_CTL_NO_ACK;
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	}
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	if (tx->flags & IEEE80211_TX_FRAGMENTED) {
		if ((tx->flags & IEEE80211_TX_UNICAST) &&
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		    skb->len + FCS_LEN > local->hw.wiphy->frag_threshold &&
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		    !(info->flags & IEEE80211_TX_CTL_AMPDU))
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			tx->flags |= IEEE80211_TX_FRAGMENTED;
1120
		else
1121
			tx->flags &= ~IEEE80211_TX_FRAGMENTED;
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	}

1124
	if (!tx->sta)
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		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1126
	else if (test_and_clear_sta_flags(tx->sta, WLAN_STA_CLEAR_PS_FILT))
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		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
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1129
	hdrlen = ieee80211_hdrlen(hdr->frame_control);
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	if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
		u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
		tx->ethertype = (pos[0] << 8) | pos[1];
	}
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	info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
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1136
	return TX_CONTINUE;
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}

1139
static int __ieee80211_tx(struct ieee80211_local *local,
1140
			  struct sk_buff **skbp,
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			  struct sta_info *sta,
			  bool txpending)
1143
{
1144
	struct sk_buff *skb = *skbp, *next;
1145
	struct ieee80211_tx_info *info;
1146
	unsigned long flags;
1147
	int ret, len;
1148
	bool fragm = false;
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1150
	while (skb) {
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		int q = skb_get_queue_mapping(skb);

		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
		ret = IEEE80211_TX_OK;
		if (local->queue_stop_reasons[q] ||
		    (!txpending && !skb_queue_empty(&local->pending[q])))
			ret = IEEE80211_TX_PENDING;
		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
		if (ret != IEEE80211_TX_OK)
			return ret;
1161

1162 1163 1164
		info = IEEE80211_SKB_CB(skb);

		if (fragm)
1165
			info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
1166
					 IEEE80211_TX_CTL_FIRST_FRAGMENT);
1167

1168
		next = skb->next;
1169
		len = skb->len;
1170
		ret = drv_tx(local, skb);
1171 1172 1173 1174
		if (WARN_ON(ret != NETDEV_TX_OK && skb->len != len)) {
			dev_kfree_skb(skb);
			ret = NETDEV_TX_OK;
		}
1175 1176
		if (ret != NETDEV_TX_OK)
			return IEEE80211_TX_AGAIN;
1177
		*skbp = skb = next;
1178 1179
		ieee80211_led_tx(local, 1);
		fragm = true;
1180
	}
1181

1182 1183 1184
	return IEEE80211_TX_OK;
}

1185 1186 1187 1188 1189 1190 1191 1192 1193
/*
 * Invoke TX handlers, return 0 on success and non-zero if the
 * frame was dropped or queued.
 */
static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
{
	struct sk_buff *skb = tx->skb;
	ieee80211_tx_result res = TX_DROP;

1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204
#define CALL_TXH(txh)		\
	res = txh(tx);		\
	if (res != TX_CONTINUE)	\
		goto txh_done;

	CALL_TXH(ieee80211_tx_h_check_assoc)
	CALL_TXH(ieee80211_tx_h_ps_buf)
	CALL_TXH(ieee80211_tx_h_select_key)
	CALL_TXH(ieee80211_tx_h_michael_mic_add)
	CALL_TXH(ieee80211_tx_h_rate_ctrl)
	CALL_TXH(ieee80211_tx_h_misc)
1205
	CALL_TXH(ieee80211_tx_h_sequence)
1206 1207 1208 1209 1210 1211
	CALL_TXH(ieee80211_tx_h_fragment)
	/* handlers after fragment must be aware of tx info fragmentation! */
	CALL_TXH(ieee80211_tx_h_encrypt)
	CALL_TXH(ieee80211_tx_h_calculate_duration)
	CALL_TXH(ieee80211_tx_h_stats)
#undef CALL_TXH
1212

1213
 txh_done:
1214
	if (unlikely(res == TX_DROP)) {
1215
		I802_DEBUG_INC(tx->local->tx_handlers_drop);
1216 1217 1218 1219 1220 1221 1222
		while (skb) {
			struct sk_buff *next;

			next = skb->next;
			dev_kfree_skb(skb);
			skb = next;
		}
1223 1224
		return -1;
	} else if (unlikely(res == TX_QUEUED)) {
1225
		I802_DEBUG_INC(tx->local->tx_handlers_queued);
1226 1227 1228 1229 1230 1231
		return -1;
	}

	return 0;
}

1232 1233
static void ieee80211_tx(struct ieee80211_sub_if_data *sdata,
			 struct sk_buff *skb, bool txpending)
1234
{
1235
	struct ieee80211_local *local = sdata->local;
1236
	struct ieee80211_tx_data tx;
1237
	ieee80211_tx_result res_prepare;
1238
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1239 1240 1241
	struct sk_buff *next;
	unsigned long flags;
	int ret, retries;
1242
	u16 queue;
1243

1244 1245
	queue = skb_get_queue_mapping(skb);

1246 1247
	if (unlikely(skb->len < 10)) {
		dev_kfree_skb(skb);
1248
		return;
1249 1250
	}

1251 1252
	rcu_read_lock();

1253
	/* initialises tx */
1254
	res_prepare = ieee80211_tx_prepare(sdata, &tx, skb);
1255

1256
	if (unlikely(res_prepare == TX_DROP)) {
1257
		dev_kfree_skb(skb);
1258
		rcu_read_unlock();
1259 1260 1261 1262
		return;
	} else if (unlikely(res_prepare == TX_QUEUED)) {
		rcu_read_unlock();
		return;
1263 1264
	}

1265
	tx.channel = local->hw.conf.channel;
1266
	info->band = tx.channel->band;
1267

1268 1269
	if (invoke_tx_handlers(&tx))
		goto out;
1270

1271 1272
	retries = 0;
 retry:
1273
	ret = __ieee80211_tx(local, &tx.skb, tx.sta, txpending);
1274 1275 1276 1277
	switch (ret) {
	case IEEE80211_TX_OK:
		break;
	case IEEE80211_TX_AGAIN:
1278 1279 1280 1281 1282
		/*
		 * Since there are no fragmented frames on A-MPDU
		 * queues, there's no reason for a driver to reject
		 * a frame there, warn and drop it.
		 */
1283 1284 1285 1286 1287
		if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
			goto drop;
		/* fall through */
	case IEEE80211_TX_PENDING:
		skb = tx.skb;
1288

1289
		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1290

1291 1292 1293 1294 1295 1296
		if (local->queue_stop_reasons[queue] ||
		    !skb_queue_empty(&local->pending[queue])) {
			/*
			 * if queue is stopped, queue up frames for later
			 * transmission from the tasklet
			 */
1297 1298 1299
			do {
				next = skb->next;
				skb->next = NULL;
1300
				if (unlikely(txpending))
1301 1302
					__skb_queue_head(&local->pending[queue],
							 skb);
1303
				else
1304 1305
					__skb_queue_tail(&local->pending[queue],
							 skb);
1306 1307 1308 1309 1310
			} while ((skb = next));

			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
					       flags);
		} else {
1311 1312 1313 1314
			/*
			 * otherwise retry, but this is a race condition or
			 * a driver bug (which we warn about if it persists)
			 */
1315 1316 1317 1318
			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
					       flags);

			retries++;
1319
			if (WARN(retries > 10, "tx refused but queue active\n"))
1320
				goto drop;
1321 1322 1323
			goto retry;
		}
	}
1324
 out:
1325
	rcu_read_unlock();
1326
	return;
1327 1328

 drop:
1329
	rcu_read_unlock();
1330 1331 1332 1333 1334 1335 1336

	skb = tx.skb;
	while (skb) {
		next = skb->next;
		dev_kfree_skb(skb);
		skb = next;
	}
1337 1338 1339 1340
}

/* device xmit handlers */

1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379
static int ieee80211_skb_resize(struct ieee80211_local *local,
				struct sk_buff *skb,
				int head_need, bool may_encrypt)
{
	int tail_need = 0;

	/*
	 * This could be optimised, devices that do full hardware
	 * crypto (including TKIP MMIC) need no tailroom... But we
	 * have no drivers for such devices currently.
	 */
	if (may_encrypt) {
		tail_need = IEEE80211_ENCRYPT_TAILROOM;
		tail_need -= skb_tailroom(skb);
		tail_need = max_t(int, tail_need, 0);
	}

	if (head_need || tail_need) {
		/* Sorry. Can't account for this any more */
		skb_orphan(skb);
	}

	if (skb_header_cloned(skb))
		I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
	else
		I802_DEBUG_INC(local->tx_expand_skb_head);

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

	/* update truesize too */
	skb->truesize += head_need + tail_need;

	return 0;
}

1380 1381
static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
			   struct sk_buff *skb)
1382
{
1383
	struct ieee80211_local *local = sdata->local;
1384
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1385
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1386
	struct ieee80211_sub_if_data *tmp_sdata;
1387
	int headroom;
1388
	bool may_encrypt;
1389 1390 1391 1392 1393
	enum {
		NOT_MONITOR,
		FOUND_SDATA,
		UNKNOWN_ADDRESS,
	} monitor_iface = NOT_MONITOR;
1394

1395
	dev_hold(sdata->dev);
1396

1397
	if ((local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) &&
1398 1399
	    local->hw.conf.dynamic_ps_timeout > 0 &&
	    !local->sw_scanning && !local->hw_scanning && local->ps_sdata) {
1400 1401 1402 1403 1404 1405 1406 1407
		if (local->hw.conf.flags & IEEE80211_CONF_PS) {
			ieee80211_stop_queues_by_reason(&local->hw,
					IEEE80211_QUEUE_STOP_REASON_PS);
			queue_work(local->hw.workqueue,
					&local->dynamic_ps_disable_work);
		}

		mod_timer(&local->dynamic_ps_timer, jiffies +
1408
		        msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
1409 1410
	}

1411 1412
	info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;

1413
	if (ieee80211_vif_is_mesh(&sdata->vif) &&
1414
	    ieee80211_is_data(hdr->frame_control)) {
1415 1416 1417
		if (is_multicast_ether_addr(hdr->addr3))
			memcpy(hdr->addr1, hdr->addr3, ETH_ALEN);
		else
1418 1419 1420
			if (mesh_nexthop_lookup(skb, sdata)) {
				dev_put(sdata->dev);
				return;
1421
			}
1422
	} else if (unlikely(sdata->vif.type == NL80211_IFTYPE_MONITOR)) {
1423 1424 1425 1426 1427 1428 1429
		int hdrlen;
		u16 len_rthdr;

		info->flags |= IEEE80211_TX_CTL_INJECTED;
		monitor_iface = UNKNOWN_ADDRESS;

		len_rthdr = ieee80211_get_radiotap_len(skb->data);
1430
		hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445
		hdrlen = ieee80211_hdrlen(hdr->frame_control);

		/* check the header is complete in the frame */
		if (likely(skb->len >= len_rthdr + hdrlen)) {
			/*
			 * We process outgoing injected frames that have a
			 * local address we handle as though they are our
			 * own frames.
			 * This code here isn't entirely correct, the local
			 * MAC address is not necessarily enough to find
			 * the interface to use; for that proper VLAN/WDS
			 * support we will need a different mechanism.
			 */

			rcu_read_lock();
1446
			list_for_each_entry_rcu(tmp_sdata, &local->interfaces,
1447
						list) {
1448
				if (!netif_running(tmp_sdata->dev))
1449
					continue;
1450
				if (tmp_sdata->vif.type != NL80211_IFTYPE_AP)
1451
					continue;
1452
				if (compare_ether_addr(tmp_sdata->dev->dev_addr,
1453
						       hdr->addr2)) {
1454 1455 1456
					dev_hold(tmp_sdata->dev);
					dev_put(sdata->dev);
					sdata = tmp_sdata;
1457 1458 1459 1460 1461 1462
					monitor_iface = FOUND_SDATA;
					break;
				}
			}
			rcu_read_unlock();
		}
1463 1464
	}

1465
	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
1466

1467
	headroom = local->tx_headroom;
1468 1469 1470 1471 1472
	if (may_encrypt)
		headroom += IEEE80211_ENCRYPT_HEADROOM;
	headroom -= skb_headroom(skb);
	headroom = max_t(int, 0, headroom);

1473
	if (ieee80211_skb_resize(local, skb, headroom, may_encrypt)) {
1474
		dev_kfree_skb(skb);
1475 1476
		dev_put(sdata->dev);
		return;
1477 1478
	}

1479 1480 1481 1482 1483
	tmp_sdata = sdata;
	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
		tmp_sdata = container_of(sdata->bss,
					 struct ieee80211_sub_if_data,
					 u.ap);
1484
	if (likely(monitor_iface != UNKNOWN_ADDRESS))
1485
		info->control.vif = &tmp_sdata->vif;
1486

1487 1488 1489
	ieee80211_select_queue(local, skb);
	ieee80211_tx(sdata, skb, false);
	dev_put(sdata->dev);
1490 1491 1492 1493 1494 1495
}

int ieee80211_monitor_start_xmit(struct sk_buff *skb,
				 struct net_device *dev)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1496
	struct ieee80211_channel *chan = local->hw.conf.channel;
1497 1498
	struct ieee80211_radiotap_header *prthdr =
		(struct ieee80211_radiotap_header *)skb->data;
1499
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1500
	u16 len_rthdr;
1501

1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521
	/*
	 * Frame injection is not allowed if beaconing is not allowed
	 * or if we need radar detection. Beaconing is usually not allowed when
	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
	 * Passive scan is also used in world regulatory domains where
	 * your country is not known and as such it should be treated as
	 * NO TX unless the channel is explicitly allowed in which case
	 * your current regulatory domain would not have the passive scan
	 * flag.
	 *
	 * Since AP mode uses monitor interfaces to inject/TX management
	 * frames we can make AP mode the exception to this rule once it
	 * supports radar detection as its implementation can deal with
	 * radar detection by itself. We can do that later by adding a
	 * monitor flag interfaces used for AP support.
	 */
	if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR |
	     IEEE80211_CHAN_PASSIVE_SCAN)))
		goto fail;

1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535
	/* check for not even having the fixed radiotap header part */
	if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
		goto fail; /* too short to be possibly valid */

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

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

	/* does the skb contain enough to deliver on the alleged length? */
	if (unlikely(skb->len < len_rthdr))
		goto fail; /* skb too short for claimed rt header extent */
1536

1537
	/* needed because we set skb device to master */
1538
	skb->iif = dev->ifindex;
1539

1540 1541 1542 1543 1544 1545
	/*
	 * fix up the pointers accounting for the radiotap
	 * header still being in there.  We are being given
	 * a precooked IEEE80211 header so no need for
	 * normal processing
	 */
1546
	skb_set_mac_header(skb, len_rthdr);
1547
	/*
1548 1549
	 * these are just fixed to the end of the rt area since we
	 * don't have any better information and at this point, nobody cares
1550
	 */
1551 1552
	skb_set_network_header(skb, len_rthdr);
	skb_set_transport_header(skb, len_rthdr);
1553

1554 1555 1556 1557
	memset(info, 0, sizeof(*info));

	/* pass the radiotap header up to xmit */
	ieee80211_xmit(IEEE80211_DEV_TO_SUB_IF(dev), skb);
1558
	return NETDEV_TX_OK;
1559 1560 1561 1562

fail:
	dev_kfree_skb(skb);
	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582
}

/**
 * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
 * subinterfaces (wlan#, WDS, and VLAN interfaces)
 * @skb: packet to be sent
 * @dev: incoming interface
 *
 * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
 * not be freed, and caller is responsible for either retrying later or freeing
 * skb).
 *
 * This function takes in an Ethernet header and encapsulates it with suitable
 * IEEE 802.11 header based on which interface the packet is coming in. The
 * encapsulated packet will then be passed to master interface, wlan#.11, for
 * transmission (through low-level driver).
 */
int ieee80211_subif_start_xmit(struct sk_buff *skb,
			       struct net_device *dev)
{
1583 1584
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	struct ieee80211_local *local = sdata->local;
1585
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1586
	int ret = NETDEV_TX_BUSY, head_need;
1587 1588
	u16 ethertype, hdrlen,  meshhdrlen = 0;
	__le16 fc;
1589
	struct ieee80211_hdr hdr;
1590
	struct ieee80211s_hdr mesh_hdr;
1591 1592
	const u8 *encaps_data;
	int encaps_len, skip_header_bytes;
1593
	int nh_pos, h_pos;
1594
	struct sta_info *sta;
1595
	u32 sta_flags = 0;
1596 1597

	if (unlikely(skb->len < ETH_HLEN)) {
1598
		ret = NETDEV_TX_OK;
1599 1600 1601 1602 1603 1604 1605 1606 1607
		goto fail;
	}

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

	/* convert Ethernet header to proper 802.11 header (based on
	 * operation mode) */
	ethertype = (skb->data[12] << 8) | skb->data[13];
1608
	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
1609

1610
	switch (sdata->vif.type) {
1611 1612
	case NL80211_IFTYPE_AP:
	case NL80211_IFTYPE_AP_VLAN:
1613
		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1614 1615 1616 1617 1618
		/* DA BSSID SA */
		memcpy(hdr.addr1, skb->data, ETH_ALEN);
		memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
		hdrlen = 24;
1619
		break;
1620
	case NL80211_IFTYPE_WDS:
1621
		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1622 1623 1624 1625 1626 1627
		/* RA TA DA SA */
		memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
		memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
		memcpy(hdr.addr3, skb->data, ETH_ALEN);
		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
		hdrlen = 30;
1628
		break;
1629
#ifdef CONFIG_MAC80211_MESH
1630
	case NL80211_IFTYPE_MESH_POINT:
1631
		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1632
		if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
1633
			/* Do not send frames with mesh_ttl == 0 */
1634
			sdata->u.mesh.mshstats.dropped_frames_ttl++;
1635
			ret = NETDEV_TX_OK;
1636
			goto fail;
1637
		}
1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675
		memset(&mesh_hdr, 0, sizeof(mesh_hdr));

		if (compare_ether_addr(dev->dev_addr,
					  skb->data + ETH_ALEN) == 0) {
			/* RA TA DA SA */
			memset(hdr.addr1, 0, ETH_ALEN);
			memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
			memcpy(hdr.addr3, skb->data, ETH_ALEN);
			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
			meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr, sdata);
		} else {
			/* packet from other interface */
			struct mesh_path *mppath;

			memset(hdr.addr1, 0, ETH_ALEN);
			memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
			memcpy(hdr.addr4, dev->dev_addr, ETH_ALEN);

			if (is_multicast_ether_addr(skb->data))
				memcpy(hdr.addr3, skb->data, ETH_ALEN);
			else {
				rcu_read_lock();
				mppath = mpp_path_lookup(skb->data, sdata);
				if (mppath)
					memcpy(hdr.addr3, mppath->mpp, ETH_ALEN);
				else
					memset(hdr.addr3, 0xff, ETH_ALEN);
				rcu_read_unlock();
			}

			mesh_hdr.flags |= MESH_FLAGS_AE_A5_A6;
			mesh_hdr.ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
			put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &mesh_hdr.seqnum);
			memcpy(mesh_hdr.eaddr1, skb->data, ETH_ALEN);
			memcpy(mesh_hdr.eaddr2, skb->data + ETH_ALEN, ETH_ALEN);
			sdata->u.mesh.mesh_seqnum++;
			meshhdrlen = 18;
		}
1676 1677 1678
		hdrlen = 30;
		break;
#endif
1679
	case NL80211_IFTYPE_STATION:
1680
		fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1681
		/* BSSID SA DA */
1682
		memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1683 1684 1685
		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
		memcpy(hdr.addr3, skb->data, ETH_ALEN);
		hdrlen = 24;
1686
		break;
1687
	case NL80211_IFTYPE_ADHOC:
1688 1689 1690
		/* DA SA BSSID */
		memcpy(hdr.addr1, skb->data, ETH_ALEN);
		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1691
		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
1692
		hdrlen = 24;
1693 1694
		break;
	default:
1695
		ret = NETDEV_TX_OK;
1696 1697 1698
		goto fail;
	}

1699 1700 1701 1702 1703 1704
	/*
	 * There's no need to try to look up the destination
	 * if it is a multicast address (which can only happen
	 * in AP mode)
	 */
	if (!is_multicast_ether_addr(hdr.addr1)) {
1705
		rcu_read_lock();
1706
		sta = sta_info_get(local, hdr.addr1);
1707
		if (sta)
1708
			sta_flags = get_sta_flags(sta);
1709
		rcu_read_unlock();
1710 1711
	}

1712
	/* receiver and we are QoS enabled, use a QoS type frame */
1713
	if ((sta_flags & WLAN_STA_WME) && local->hw.queues >= 4) {
1714
		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1715 1716 1717 1718
		hdrlen += 2;
	}

	/*
1719 1720
	 * Drop unicast frames to unauthorised stations unless they are
	 * EAPOL frames from the local station.
1721
	 */
1722 1723
	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
		unlikely(!is_multicast_ether_addr(hdr.addr1) &&
1724 1725
		      !(sta_flags & WLAN_STA_AUTHORIZED) &&
		      !(ethertype == ETH_P_PAE &&
1726 1727 1728 1729
		       compare_ether_addr(dev->dev_addr,
					  skb->data + ETH_ALEN) == 0))) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
		if (net_ratelimit())
1730
			printk(KERN_DEBUG "%s: dropped frame to %pM"
1731
			       " (unauthorized port)\n", dev->name,
1732
			       hdr.addr1);
1733 1734 1735 1736
#endif

		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);

1737
		ret = NETDEV_TX_OK;
1738 1739 1740
		goto fail;
	}

1741
	hdr.frame_control = fc;
1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762
	hdr.duration_id = 0;
	hdr.seq_ctrl = 0;

	skip_header_bytes = ETH_HLEN;
	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
		encaps_data = bridge_tunnel_header;
		encaps_len = sizeof(bridge_tunnel_header);
		skip_header_bytes -= 2;
	} else if (ethertype >= 0x600) {
		encaps_data = rfc1042_header;
		encaps_len = sizeof(rfc1042_header);
		skip_header_bytes -= 2;
	} else {
		encaps_data = NULL;
		encaps_len = 0;
	}

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

1763
	head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
1764

1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775
	/*
	 * So we need to modify the skb header and hence need a copy of
	 * that. The head_need variable above doesn't, so far, include
	 * the needed header space that we don't need right away. If we
	 * can, then we don't reallocate right now but only after the
	 * frame arrives at the master device (if it does...)
	 *
	 * If we cannot, however, then we will reallocate to include all
	 * the ever needed space. Also, if we need to reallocate it anyway,
	 * make it big enough for everything we may ever need.
	 */
1776

1777
	if (head_need > 0 || skb_cloned(skb)) {
1778 1779 1780 1781
		head_need += IEEE80211_ENCRYPT_HEADROOM;
		head_need += local->tx_headroom;
		head_need = max_t(int, 0, head_need);
		if (ieee80211_skb_resize(local, skb, head_need, true))
1782 1783 1784 1785 1786 1787 1788 1789
			goto fail;
	}

	if (encaps_data) {
		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
		nh_pos += encaps_len;
		h_pos += encaps_len;
	}
1790

1791 1792 1793 1794 1795 1796
	if (meshhdrlen > 0) {
		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
		nh_pos += meshhdrlen;
		h_pos += meshhdrlen;
	}

1797
	if (ieee80211_is_data_qos(fc)) {
1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809
		__le16 *qos_control;

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

1810 1811 1812
	nh_pos += hdrlen;
	h_pos += hdrlen;

1813
	skb->iif = dev->ifindex;
1814

1815 1816
	dev->stats.tx_packets++;
	dev->stats.tx_bytes += skb->len;
1817 1818 1819 1820 1821 1822 1823 1824

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

1825 1826
	memset(info, 0, sizeof(*info));

1827
	dev->trans_start = jiffies;
1828
	ieee80211_xmit(sdata, skb);
1829

1830
	return NETDEV_TX_OK;
1831 1832

 fail:
1833
	if (ret == NETDEV_TX_OK)
1834 1835 1836 1837 1838 1839
		dev_kfree_skb(skb);

	return ret;
}


1840 1841 1842 1843
/*
 * ieee80211_clear_tx_pending may not be called in a context where
 * it is possible that it packets could come in again.
 */
1844 1845
void ieee80211_clear_tx_pending(struct ieee80211_local *local)
{
1846
	int i;
1847

1848 1849
	for (i = 0; i < local->hw.queues; i++)
		skb_queue_purge(&local->pending[i]);
1850 1851
}

1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882
static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
				     struct sk_buff *skb)
{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ieee80211_sub_if_data *sdata;
	struct sta_info *sta;
	struct ieee80211_hdr *hdr;
	struct net_device *dev;
	int ret;
	bool result = true;

	/* does interface still exist? */
	dev = dev_get_by_index(&init_net, skb->iif);
	if (!dev) {
		dev_kfree_skb(skb);
		return true;
	}

	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
		sdata = container_of(sdata->bss,
				     struct ieee80211_sub_if_data,
				     u.ap);

	if (unlikely(info->control.vif && info->control.vif != &sdata->vif)) {
		dev_kfree_skb(skb);
		result = true;
		goto out;
	}

	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
1883 1884
		/* do not use sdata, it may have been changed above */
		ieee80211_tx(IEEE80211_DEV_TO_SUB_IF(dev), skb, true);
1885 1886 1887 1888
	} else {
		hdr = (struct ieee80211_hdr *)skb->data;
		sta = sta_info_get(local, hdr->addr1);

1889
		ret = __ieee80211_tx(local, &skb, sta, true);
1890 1891 1892 1893 1894 1895 1896 1897 1898 1899
		if (ret != IEEE80211_TX_OK)
			result = false;
	}

 out:
	dev_put(dev);

	return result;
}

1900
/*
1901
 * Transmit all pending packets. Called from tasklet.
1902
 */
1903 1904 1905
void ieee80211_tx_pending(unsigned long data)
{
	struct ieee80211_local *local = (struct ieee80211_local *)data;
1906
	unsigned long flags;
1907
	int i;
1908
	bool txok;
1909

1910
	rcu_read_lock();
1911

1912
	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1913 1914 1915 1916 1917
	for (i = 0; i < local->hw.queues; i++) {
		/*
		 * If queue is stopped by something other than due to pending
		 * frames, or we have no pending frames, proceed to next queue.
		 */
1918
		if (local->queue_stop_reasons[i] ||
1919
		    skb_queue_empty(&local->pending[i]))
1920
			continue;
1921

1922
		while (!skb_queue_empty(&local->pending[i])) {
1923 1924 1925 1926 1927 1928 1929 1930 1931 1932
			struct sk_buff *skb = __skb_dequeue(&local->pending[i]);
			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
						flags);

			txok = ieee80211_tx_pending_skb(local, skb);
			if (!txok)
				__skb_queue_head(&local->pending[i], skb);
			spin_lock_irqsave(&local->queue_stop_reason_lock,
					  flags);
			if (!txok)
1933
				break;
1934 1935
		}
	}
1936
	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
1937

1938
	rcu_read_unlock();
1939 1940 1941 1942
}

/* functions for drivers to get certain frames */

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Rami Rosen committed
1943
static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss,
1944 1945
				     struct sk_buff *skb,
				     struct beacon_data *beacon)
1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959
{
	u8 *pos, *tim;
	int aid0 = 0;
	int i, have_bits = 0, n1, n2;

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

	if (bss->dtim_count == 0)
1960
		bss->dtim_count = beacon->dtim_period - 1;
1961 1962 1963 1964 1965 1966 1967
	else
		bss->dtim_count--;

	tim = pos = (u8 *) skb_put(skb, 6);
	*pos++ = WLAN_EID_TIM;
	*pos++ = 4;
	*pos++ = bss->dtim_count;
1968
	*pos++ = beacon->dtim_period;
1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004

	if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
		aid0 = 1;

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

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

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

2005
struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
2006
				     struct ieee80211_vif *vif)
2007 2008
{
	struct ieee80211_local *local = hw_to_local(hw);
2009
	struct sk_buff *skb = NULL;
2010
	struct ieee80211_tx_info *info;
2011 2012
	struct ieee80211_sub_if_data *sdata = NULL;
	struct ieee80211_if_ap *ap = NULL;
2013
	struct beacon_data *beacon;
2014
	struct ieee80211_supported_band *sband;
2015
	enum ieee80211_band band = local->hw.conf.channel->band;
2016

2017
	sband = local->hw.wiphy->bands[band];
2018 2019

	rcu_read_lock();
2020

2021
	sdata = vif_to_sdata(vif);
2022

2023
	if (sdata->vif.type == NL80211_IFTYPE_AP) {
2024 2025
		ap = &sdata->u.ap;
		beacon = rcu_dereference(ap->beacon);
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2026 2027 2028 2029 2030 2031 2032 2033 2034 2035
		if (ap && beacon) {
			/*
			 * headroom, head length,
			 * tail length and maximum TIM length
			 */
			skb = dev_alloc_skb(local->tx_headroom +
					    beacon->head_len +
					    beacon->tail_len + 256);
			if (!skb)
				goto out;
2036

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Johannes Berg committed
2037 2038 2039
			skb_reserve(skb, local->tx_headroom);
			memcpy(skb_put(skb, beacon->head_len), beacon->head,
			       beacon->head_len);
2040

2041 2042 2043 2044 2045 2046 2047 2048
			/*
			 * Not very nice, but we want to allow the driver to call
			 * ieee80211_beacon_get() as a response to the set_tim()
			 * callback. That, however, is already invoked under the
			 * sta_lock to guarantee consistent and race-free update
			 * of the tim bitmap in mac80211 and the driver.
			 */
			if (local->tim_in_locked_section) {
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2049
				ieee80211_beacon_add_tim(ap, skb, beacon);
2050 2051 2052 2053
			} else {
				unsigned long flags;

				spin_lock_irqsave(&local->sta_lock, flags);
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2054
				ieee80211_beacon_add_tim(ap, skb, beacon);
2055 2056
				spin_unlock_irqrestore(&local->sta_lock, flags);
			}
2057

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2058 2059 2060
			if (beacon->tail)
				memcpy(skb_put(skb, beacon->tail_len),
				       beacon->tail, beacon->tail_len);
2061 2062
		} else
			goto out;
2063
	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
2064
		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2065
		struct ieee80211_hdr *hdr;
2066
		struct sk_buff *presp = rcu_dereference(ifibss->presp);
2067

2068
		if (!presp)
2069 2070
			goto out;

2071
		skb = skb_copy(presp, GFP_ATOMIC);
2072 2073 2074 2075
		if (!skb)
			goto out;

		hdr = (struct ieee80211_hdr *) skb->data;
2076 2077
		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
						 IEEE80211_STYPE_BEACON);
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2078
	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2079 2080 2081
		struct ieee80211_mgmt *mgmt;
		u8 *pos;

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2082 2083 2084 2085 2086 2087 2088 2089 2090
		/* headroom, head length, tail length and maximum TIM length */
		skb = dev_alloc_skb(local->tx_headroom + 400);
		if (!skb)
			goto out;

		skb_reserve(skb, local->hw.extra_tx_headroom);
		mgmt = (struct ieee80211_mgmt *)
			skb_put(skb, 24 + sizeof(mgmt->u.beacon));
		memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
2091 2092
		mgmt->frame_control =
		    cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
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2093 2094 2095 2096
		memset(mgmt->da, 0xff, ETH_ALEN);
		memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
		/* BSSID is left zeroed, wildcard value */
		mgmt->u.beacon.beacon_int =
2097
			cpu_to_le16(sdata->vif.bss_conf.beacon_int);
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2098 2099 2100 2101 2102 2103
		mgmt->u.beacon.capab_info = 0x0; /* 0x0 for MPs */

		pos = skb_put(skb, 2);
		*pos++ = WLAN_EID_SSID;
		*pos++ = 0x0;

2104
		mesh_mgmt_ies_add(skb, sdata);
2105 2106
	} else {
		WARN_ON(1);
2107
		goto out;
2108 2109
	}

2110 2111
	info = IEEE80211_SKB_CB(skb);

2112
	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
2113
	info->band = band;
2114 2115 2116 2117 2118 2119 2120 2121 2122 2123
	/*
	 * XXX: For now, always use the lowest rate
	 */
	info->control.rates[0].idx = 0;
	info->control.rates[0].count = 1;
	info->control.rates[1].idx = -1;
	info->control.rates[2].idx = -1;
	info->control.rates[3].idx = -1;
	info->control.rates[4].idx = -1;
	BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
2124 2125

	info->control.vif = vif;
2126 2127 2128 2129

	info->flags |= IEEE80211_TX_CTL_NO_ACK;
	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
	info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
2130
 out:
2131
	rcu_read_unlock();
2132 2133 2134 2135
	return skb;
}
EXPORT_SYMBOL(ieee80211_beacon_get);

2136
void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2137
		       const void *frame, size_t frame_len,
2138
		       const struct ieee80211_tx_info *frame_txctl,
2139 2140 2141 2142
		       struct ieee80211_rts *rts)
{
	const struct ieee80211_hdr *hdr = frame;

2143 2144
	rts->frame_control =
	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2145 2146
	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
					       frame_txctl);
2147 2148 2149 2150 2151
	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
}
EXPORT_SYMBOL(ieee80211_rts_get);

2152
void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2153
			     const void *frame, size_t frame_len,
2154
			     const struct ieee80211_tx_info *frame_txctl,
2155 2156 2157 2158
			     struct ieee80211_cts *cts)
{
	const struct ieee80211_hdr *hdr = frame;

2159 2160
	cts->frame_control =
	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2161 2162
	cts->duration = ieee80211_ctstoself_duration(hw, vif,
						     frame_len, frame_txctl);
2163 2164 2165 2166 2167
	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
}
EXPORT_SYMBOL(ieee80211_ctstoself_get);

struct sk_buff *
2168
ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2169
			  struct ieee80211_vif *vif)
2170 2171
{
	struct ieee80211_local *local = hw_to_local(hw);
2172
	struct sk_buff *skb = NULL;
2173
	struct sta_info *sta;
2174
	struct ieee80211_tx_data tx;
2175 2176
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_if_ap *bss = NULL;
2177
	struct beacon_data *beacon;
2178
	struct ieee80211_tx_info *info;
2179

2180
	sdata = vif_to_sdata(vif);
2181
	bss = &sdata->u.ap;
2182 2183 2184 2185

	rcu_read_lock();
	beacon = rcu_dereference(bss->beacon);

2186
	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
2187
		goto out;
2188

2189
	if (bss->dtim_count != 0)
2190
		goto out; /* send buffered bc/mc only after DTIM beacon */
2191

2192 2193 2194
	while (1) {
		skb = skb_dequeue(&bss->ps_bc_buf);
		if (!skb)
2195
			goto out;
2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207
		local->total_ps_buffered--;

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

2208
		if (!ieee80211_tx_prepare(sdata, &tx, skb))
2209 2210 2211
			break;
		dev_kfree_skb_any(skb);
	}
2212 2213 2214

	info = IEEE80211_SKB_CB(skb);

2215
	sta = tx.sta;
2216 2217
	tx.flags |= IEEE80211_TX_PS_BUFFERED;
	tx.channel = local->hw.conf.channel;
2218
	info->band = tx.channel->band;
2219

2220
	if (invoke_tx_handlers(&tx))
2221
		skb = NULL;
2222
 out:
2223
	rcu_read_unlock();
2224 2225 2226 2227

	return skb;
}
EXPORT_SYMBOL(ieee80211_get_buffered_bc);
2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240

void ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
		      int encrypt)
{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	skb_set_mac_header(skb, 0);
	skb_set_network_header(skb, 0);
	skb_set_transport_header(skb, 0);

	skb->iif = sdata->dev->ifindex;
	if (!encrypt)
		info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;

2241 2242 2243 2244 2245 2246
	/*
	 * The other path calling ieee80211_xmit is from the tasklet,
	 * and while we can handle concurrent transmissions locking
	 * requirements are that we do not come into tx with bhs on.
	 */
	local_bh_disable();
2247
	ieee80211_xmit(sdata, skb);
2248
	local_bh_enable();
2249
}