tx.c 53.9 KB
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/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 *
 * 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"
#include "ieee80211_led.h"
#include "wep.h"
#include "wpa.h"
#include "wme.h"
#include "ieee80211_rate.h"

#define IEEE80211_TX_OK		0
#define IEEE80211_TX_AGAIN	1
#define IEEE80211_TX_FRAG_AGAIN	2

/* misc utils */

static inline void ieee80211_include_sequence(struct ieee80211_sub_if_data *sdata,
					      struct ieee80211_hdr *hdr)
{
	/* Set the sequence number for this frame. */
	hdr->seq_ctrl = cpu_to_le16(sdata->sequence);

	/* Increase the sequence number. */
	sdata->sequence = (sdata->sequence + 0x10) & IEEE80211_SCTL_SEQ;
}

#ifdef CONFIG_MAC80211_LOWTX_FRAME_DUMP
static void ieee80211_dump_frame(const char *ifname, const char *title,
				 const struct sk_buff *skb)
{
	const struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	u16 fc;
	int hdrlen;
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	DECLARE_MAC_BUF(mac);
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	printk(KERN_DEBUG "%s: %s (len=%d)", ifname, title, skb->len);
	if (skb->len < 4) {
		printk("\n");
		return;
	}

	fc = le16_to_cpu(hdr->frame_control);
	hdrlen = ieee80211_get_hdrlen(fc);
	if (hdrlen > skb->len)
		hdrlen = skb->len;
	if (hdrlen >= 4)
		printk(" FC=0x%04x DUR=0x%04x",
		       fc, le16_to_cpu(hdr->duration_id));
	if (hdrlen >= 10)
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		printk(" A1=%s", print_mac(mac, hdr->addr1));
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	if (hdrlen >= 16)
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		printk(" A2=%s", print_mac(mac, hdr->addr2));
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	if (hdrlen >= 24)
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		printk(" A3=%s", print_mac(mac, hdr->addr3));
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	if (hdrlen >= 30)
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		printk(" A4=%s", print_mac(mac, hdr->addr4));
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	printk("\n");
}
#else /* CONFIG_MAC80211_LOWTX_FRAME_DUMP */
static inline void ieee80211_dump_frame(const char *ifname, const char *title,
					struct sk_buff *skb)
{
}
#endif /* CONFIG_MAC80211_LOWTX_FRAME_DUMP */

static u16 ieee80211_duration(struct ieee80211_txrx_data *tx, int group_addr,
			      int next_frag_len)
{
	int rate, mrate, erp, dur, i;
	struct ieee80211_rate *txrate = tx->u.tx.rate;
	struct ieee80211_local *local = tx->local;
	struct ieee80211_hw_mode *mode = tx->u.tx.mode;

	erp = txrate->flags & IEEE80211_RATE_ERP;

	/*
	 * 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
	 */

	if ((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL) {
		/* TODO: These control frames are not currently sent by
		 * 80211.o, but should they be implemented, this function
		 * 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 */)
		return 32768;

	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;
	mrate = 10; /* use 1 Mbps if everything fails */
	for (i = 0; i < mode->num_rates; i++) {
		struct ieee80211_rate *r = &mode->rates[i];
		if (r->rate > txrate->rate)
			break;

		if (IEEE80211_RATE_MODULATION(txrate->flags) !=
		    IEEE80211_RATE_MODULATION(r->flags))
			continue;

		if (r->flags & IEEE80211_RATE_BASIC)
			rate = r->rate;
		else if (r->flags & IEEE80211_RATE_MANDATORY)
			mrate = r->rate;
	}
	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->flags & IEEE80211_SDATA_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->rate, erp,
				tx->sdata->flags &
					IEEE80211_SDATA_SHORT_PREAMBLE);
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	}

	return dur;
}

static inline int __ieee80211_queue_stopped(const struct ieee80211_local *local,
					    int queue)
{
	return test_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]);
}

static inline int __ieee80211_queue_pending(const struct ieee80211_local *local,
					    int queue)
{
	return test_bit(IEEE80211_LINK_STATE_PENDING, &local->state[queue]);
}

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

/* tx handlers */

static ieee80211_txrx_result
ieee80211_tx_h_check_assoc(struct ieee80211_txrx_data *tx)
{
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
	struct sk_buff *skb = tx->skb;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
	u32 sta_flags;

	if (unlikely(tx->local->sta_scanning != 0) &&
	    ((tx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
	     (tx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PROBE_REQ))
		return TXRX_DROP;

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	if (tx->flags & IEEE80211_TXRXD_TXPS_BUFFERED)
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		return TXRX_CONTINUE;

	sta_flags = tx->sta ? tx->sta->flags : 0;

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	if (likely(tx->flags & IEEE80211_TXRXD_TXUNICAST)) {
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		if (unlikely(!(sta_flags & WLAN_STA_ASSOC) &&
			     tx->sdata->type != IEEE80211_IF_TYPE_IBSS &&
			     (tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
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			DECLARE_MAC_BUF(mac);
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			printk(KERN_DEBUG "%s: dropped data frame to not "
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			       "associated station %s\n",
			       tx->dev->name, print_mac(mac, hdr->addr1));
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#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
			I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
			return TXRX_DROP;
		}
	} else {
		if (unlikely((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
			     tx->local->num_sta == 0 &&
			     tx->sdata->type != IEEE80211_IF_TYPE_IBSS)) {
			/*
			 * No associated STAs - no need to send multicast
			 * frames.
			 */
			return TXRX_DROP;
		}
		return TXRX_CONTINUE;
	}

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	if (unlikely(/* !injected && */ tx->sdata->ieee802_1x &&
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		     !(sta_flags & WLAN_STA_AUTHORIZED))) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
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		DECLARE_MAC_BUF(mac);
		printk(KERN_DEBUG "%s: dropped frame to %s"
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		       " (unauthorized port)\n", tx->dev->name,
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		       print_mac(mac, hdr->addr1));
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#endif
		I802_DEBUG_INC(tx->local->tx_handlers_drop_unauth_port);
		return TXRX_DROP;
	}

	return TXRX_CONTINUE;
}

static ieee80211_txrx_result
ieee80211_tx_h_sequence(struct ieee80211_txrx_data *tx)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;

	if (ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control)) >= 24)
		ieee80211_include_sequence(tx->sdata, hdr);

	return TXRX_CONTINUE;
}

/* 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;
		if (sdata->dev == local->mdev ||
		    sdata->type != IEEE80211_IF_TYPE_AP)
			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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	rcu_read_unlock();
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	read_lock_bh(&local->sta_lock);
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	list_for_each_entry(sta, &local->sta_list, list) {
		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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	read_unlock_bh(&local->sta_lock);
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	local->total_ps_buffered = total;
	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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}

static inline ieee80211_txrx_result
ieee80211_tx_h_multicast_ps_buf(struct ieee80211_txrx_data *tx)
{
	/* 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 */
	if ((tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING) &&
	    tx->sdata->type != IEEE80211_IF_TYPE_WDS &&
	    tx->sdata->bss && atomic_read(&tx->sdata->bss->num_sta_ps) &&
	    !(tx->fc & IEEE80211_FCTL_ORDER)) {
		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) {
			if (net_ratelimit()) {
				printk(KERN_DEBUG "%s: BC TX buffer full - "
				       "dropping the oldest frame\n",
				       tx->dev->name);
			}
			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);
		return TXRX_QUEUED;
	}

	return TXRX_CONTINUE;
}

static inline ieee80211_txrx_result
ieee80211_tx_h_unicast_ps_buf(struct ieee80211_txrx_data *tx)
{
	struct sta_info *sta = tx->sta;
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	DECLARE_MAC_BUF(mac);
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	if (unlikely(!sta ||
		     ((tx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT &&
		      (tx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PROBE_RESP)))
		return TXRX_CONTINUE;

	if (unlikely((sta->flags & WLAN_STA_PS) && !sta->pspoll)) {
		struct ieee80211_tx_packet_data *pkt_data;
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
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		printk(KERN_DEBUG "STA %s aid %d: PS buffer (entries "
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		       "before %d)\n",
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		       print_mac(mac, sta->addr), sta->aid,
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		       skb_queue_len(&sta->ps_tx_buf));
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
		sta->flags |= WLAN_STA_TIM;
		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);
			if (net_ratelimit()) {
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				printk(KERN_DEBUG "%s: STA %s TX "
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				       "buffer full - dropping oldest frame\n",
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				       tx->dev->name, print_mac(mac, sta->addr));
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			}
			dev_kfree_skb(old);
		} else
			tx->local->total_ps_buffered++;
		/* Queue frame to be sent after STA sends an PS Poll frame */
		if (skb_queue_empty(&sta->ps_tx_buf)) {
			if (tx->local->ops->set_tim)
				tx->local->ops->set_tim(local_to_hw(tx->local),
						       sta->aid, 1);
			if (tx->sdata->bss)
				bss_tim_set(tx->local, tx->sdata->bss, sta->aid);
		}
		pkt_data = (struct ieee80211_tx_packet_data *)tx->skb->cb;
		pkt_data->jiffies = jiffies;
		skb_queue_tail(&sta->ps_tx_buf, tx->skb);
		return TXRX_QUEUED;
	}
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
	else if (unlikely(sta->flags & WLAN_STA_PS)) {
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		printk(KERN_DEBUG "%s: STA %s in PS mode, but pspoll "
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		       "set -> send frame\n", tx->dev->name,
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		       print_mac(mac, sta->addr));
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	}
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
	sta->pspoll = 0;

	return TXRX_CONTINUE;
}


static ieee80211_txrx_result
ieee80211_tx_h_ps_buf(struct ieee80211_txrx_data *tx)
{
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	if (unlikely(tx->flags & IEEE80211_TXRXD_TXPS_BUFFERED))
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		return TXRX_CONTINUE;

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	if (tx->flags & IEEE80211_TXRXD_TXUNICAST)
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		return ieee80211_tx_h_unicast_ps_buf(tx);
	else
		return ieee80211_tx_h_multicast_ps_buf(tx);
}




static ieee80211_txrx_result
ieee80211_tx_h_select_key(struct ieee80211_txrx_data *tx)
{
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	struct ieee80211_key *key;

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	if (unlikely(tx->u.tx.control->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT))
		tx->key = NULL;
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	else if (tx->sta && (key = rcu_dereference(tx->sta->key)))
		tx->key = key;
	else if ((key = rcu_dereference(tx->sdata->default_key)))
		tx->key = key;
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	else if (tx->sdata->drop_unencrypted &&
		 !(tx->sdata->eapol && ieee80211_is_eapol(tx->skb))) {
		I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
		return TXRX_DROP;
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	} else {
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		tx->key = NULL;
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		tx->u.tx.control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
	}
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	if (tx->key) {
		tx->key->tx_rx_count++;
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		/* TODO: add threshold stuff again */
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	}

	return TXRX_CONTINUE;
}

static ieee80211_txrx_result
ieee80211_tx_h_fragment(struct ieee80211_txrx_data *tx)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
	size_t hdrlen, per_fragm, num_fragm, payload_len, left;
	struct sk_buff **frags, *first, *frag;
	int i;
	u16 seq;
	u8 *pos;
	int frag_threshold = tx->local->fragmentation_threshold;

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	if (!(tx->flags & IEEE80211_TXRXD_FRAGMENTED))
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		return TXRX_CONTINUE;

	first = tx->skb;

	hdrlen = ieee80211_get_hdrlen(tx->fc);
	payload_len = first->len - hdrlen;
	per_fragm = frag_threshold - hdrlen - FCS_LEN;
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	num_fragm = DIV_ROUND_UP(payload_len, per_fragm);
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	frags = kzalloc(num_fragm * sizeof(struct sk_buff *), GFP_ATOMIC);
	if (!frags)
		goto fail;

	hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
	seq = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_SEQ;
	pos = first->data + hdrlen + per_fragm;
	left = payload_len - per_fragm;
	for (i = 0; i < num_fragm - 1; i++) {
		struct ieee80211_hdr *fhdr;
		size_t copylen;

		if (left <= 0)
			goto fail;

		/* reserve enough extra head and tail room for possible
		 * encryption */
		frag = frags[i] =
			dev_alloc_skb(tx->local->tx_headroom +
				      frag_threshold +
				      IEEE80211_ENCRYPT_HEADROOM +
				      IEEE80211_ENCRYPT_TAILROOM);
		if (!frag)
			goto fail;
		/* Make sure that all fragments use the same priority so
		 * that they end up using the same TX queue */
		frag->priority = first->priority;
		skb_reserve(frag, tx->local->tx_headroom +
				  IEEE80211_ENCRYPT_HEADROOM);
		fhdr = (struct ieee80211_hdr *) skb_put(frag, hdrlen);
		memcpy(fhdr, first->data, hdrlen);
		if (i == num_fragm - 2)
			fhdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREFRAGS);
		fhdr->seq_ctrl = cpu_to_le16(seq | ((i + 1) & IEEE80211_SCTL_FRAG));
		copylen = left > per_fragm ? per_fragm : left;
		memcpy(skb_put(frag, copylen), pos, copylen);

		pos += copylen;
		left -= copylen;
	}
	skb_trim(first, hdrlen + per_fragm);

	tx->u.tx.num_extra_frag = num_fragm - 1;
	tx->u.tx.extra_frag = frags;

	return TXRX_CONTINUE;

 fail:
	printk(KERN_DEBUG "%s: failed to fragment frame\n", tx->dev->name);
	if (frags) {
		for (i = 0; i < num_fragm - 1; i++)
			if (frags[i])
				dev_kfree_skb(frags[i]);
		kfree(frags);
	}
	I802_DEBUG_INC(tx->local->tx_handlers_drop_fragment);
	return TXRX_DROP;
}

static ieee80211_txrx_result
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ieee80211_tx_h_encrypt(struct ieee80211_txrx_data *tx)
546
{
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	if (!tx->key)
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		return TXRX_CONTINUE;

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	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);
	case ALG_NONE:
		return TXRX_CONTINUE;
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	}

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

static ieee80211_txrx_result
ieee80211_tx_h_rate_ctrl(struct ieee80211_txrx_data *tx)
{
	struct rate_control_extra extra;

	memset(&extra, 0, sizeof(extra));
	extra.mode = tx->u.tx.mode;
	extra.ethertype = tx->ethertype;

	tx->u.tx.rate = rate_control_get_rate(tx->local, tx->dev, tx->skb,
					      &extra);
	if (unlikely(extra.probe != NULL)) {
		tx->u.tx.control->flags |= IEEE80211_TXCTL_RATE_CTRL_PROBE;
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		tx->flags |= IEEE80211_TXRXD_TXPROBE_LAST_FRAG;
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		tx->u.tx.control->alt_retry_rate = tx->u.tx.rate->val;
		tx->u.tx.rate = extra.probe;
	} else {
		tx->u.tx.control->alt_retry_rate = -1;
	}
	if (!tx->u.tx.rate)
		return TXRX_DROP;
	if (tx->u.tx.mode->mode == MODE_IEEE80211G &&
588
	    (tx->sdata->flags & IEEE80211_SDATA_USE_PROTECTION) &&
589
	    (tx->flags & IEEE80211_TXRXD_FRAGMENTED) && extra.nonerp) {
590
		tx->u.tx.last_frag_rate = tx->u.tx.rate;
591 592 593 594
		if (extra.probe)
			tx->flags &= ~IEEE80211_TXRXD_TXPROBE_LAST_FRAG;
		else
			tx->flags |= IEEE80211_TXRXD_TXPROBE_LAST_FRAG;
595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610
		tx->u.tx.rate = extra.nonerp;
		tx->u.tx.control->rate = extra.nonerp;
		tx->u.tx.control->flags &= ~IEEE80211_TXCTL_RATE_CTRL_PROBE;
	} else {
		tx->u.tx.last_frag_rate = tx->u.tx.rate;
		tx->u.tx.control->rate = tx->u.tx.rate;
	}
	tx->u.tx.control->tx_rate = tx->u.tx.rate->val;

	return TXRX_CONTINUE;
}

static ieee80211_txrx_result
ieee80211_tx_h_misc(struct ieee80211_txrx_data *tx)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
611
	u16 fc = le16_to_cpu(hdr->frame_control);
612 613 614 615 616 617 618 619
	u16 dur;
	struct ieee80211_tx_control *control = tx->u.tx.control;
	struct ieee80211_hw_mode *mode = tx->u.tx.mode;

	if (!is_multicast_ether_addr(hdr->addr1)) {
		if (tx->skb->len + FCS_LEN > tx->local->rts_threshold &&
		    tx->local->rts_threshold < IEEE80211_MAX_RTS_THRESHOLD) {
			control->flags |= IEEE80211_TXCTL_USE_RTS_CTS;
620
			control->flags |= IEEE80211_TXCTL_LONG_RETRY_LIMIT;
621 622 623 624 625 626 627 628 629 630
			control->retry_limit =
				tx->local->long_retry_limit;
		} else {
			control->retry_limit =
				tx->local->short_retry_limit;
		}
	} else {
		control->retry_limit = 1;
	}

631
	if (tx->flags & IEEE80211_TXRXD_FRAGMENTED) {
632 633 634 635 636 637 638 639 640 641 642 643
		/* Do not use multiple retry rates when sending fragmented
		 * frames.
		 * TODO: The last fragment could still use multiple retry
		 * rates. */
		control->alt_retry_rate = -1;
	}

	/* Use CTS protection for unicast frames sent using extended rates if
	 * there are associated non-ERP stations and RTS/CTS is not configured
	 * for the frame. */
	if (mode->mode == MODE_IEEE80211G &&
	    (tx->u.tx.rate->flags & IEEE80211_RATE_ERP) &&
644
	    (tx->flags & IEEE80211_TXRXD_TXUNICAST) &&
645
	    (tx->sdata->flags & IEEE80211_SDATA_USE_PROTECTION) &&
646 647 648
	    !(control->flags & IEEE80211_TXCTL_USE_RTS_CTS))
		control->flags |= IEEE80211_TXCTL_USE_CTS_PROTECT;

649 650 651 652 653
	/* Transmit data frames using short preambles if the driver supports
	 * short preambles at the selected rate and short preambles are
	 * available on the network at the current point in time. */
	if (((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) &&
	    (tx->u.tx.rate->flags & IEEE80211_RATE_PREAMBLE2) &&
654
	    (tx->sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE) &&
655 656 657 658
	    (!tx->sta || (tx->sta->flags & WLAN_STA_SHORT_PREAMBLE))) {
		tx->u.tx.control->tx_rate = tx->u.tx.rate->val2;
	}

659 660 661 662
	/* Setup duration field for the first fragment of the frame. Duration
	 * for remaining fragments will be updated when they are being sent
	 * to low-level driver in ieee80211_tx(). */
	dur = ieee80211_duration(tx, is_multicast_ether_addr(hdr->addr1),
663 664
				 (tx->flags & IEEE80211_TXRXD_FRAGMENTED) ?
				 tx->u.tx.extra_frag[0]->len : 0);
665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697
	hdr->duration_id = cpu_to_le16(dur);

	if ((control->flags & IEEE80211_TXCTL_USE_RTS_CTS) ||
	    (control->flags & IEEE80211_TXCTL_USE_CTS_PROTECT)) {
		struct ieee80211_rate *rate;

		/* Do not use multiple retry rates when using RTS/CTS */
		control->alt_retry_rate = -1;

		/* Use min(data rate, max base rate) as CTS/RTS rate */
		rate = tx->u.tx.rate;
		while (rate > mode->rates &&
		       !(rate->flags & IEEE80211_RATE_BASIC))
			rate--;

		control->rts_cts_rate = rate->val;
		control->rts_rate = rate;
	}

	if (tx->sta) {
		tx->sta->tx_packets++;
		tx->sta->tx_fragments++;
		tx->sta->tx_bytes += tx->skb->len;
		if (tx->u.tx.extra_frag) {
			int i;
			tx->sta->tx_fragments += tx->u.tx.num_extra_frag;
			for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
				tx->sta->tx_bytes +=
					tx->u.tx.extra_frag[i]->len;
			}
		}
	}

698 699 700 701 702 703 704 705 706
	/*
	 * Tell hardware to not encrypt when we had sw crypto.
	 * Because we use the same flag to internally indicate that
	 * no (software) encryption should be done, we have to set it
	 * after all crypto handlers.
	 */
	if (tx->key && !(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
		tx->u.tx.control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;

707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775
	return TXRX_CONTINUE;
}

static ieee80211_txrx_result
ieee80211_tx_h_load_stats(struct ieee80211_txrx_data *tx)
{
	struct ieee80211_local *local = tx->local;
	struct ieee80211_hw_mode *mode = tx->u.tx.mode;
	struct sk_buff *skb = tx->skb;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	u32 load = 0, hdrtime;

	/* TODO: this could be part of tx_status handling, so that the number
	 * of retries would be known; TX rate should in that case be stored
	 * somewhere with the packet */

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

	/* 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 &&
	     tx->u.tx.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;

	if (tx->u.tx.control->flags & IEEE80211_TXCTL_USE_RTS_CTS)
		load += 2 * hdrtime;
	else if (tx->u.tx.control->flags & IEEE80211_TXCTL_USE_CTS_PROTECT)
		load += hdrtime;

	load += skb->len * tx->u.tx.rate->rate_inv;

	if (tx->u.tx.extra_frag) {
		int i;
		for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
			load += 2 * hdrtime;
			load += tx->u.tx.extra_frag[i]->len *
				tx->u.tx.rate->rate;
		}
	}

	/* Divide channel_use by 8 to avoid wrapping around the counter */
	load >>= CHAN_UTIL_SHIFT;
	local->channel_use_raw += load;
	if (tx->sta)
		tx->sta->channel_use_raw += load;
	tx->sdata->channel_use_raw += load;

	return TXRX_CONTINUE;
}

/* TODO: implement register/unregister functions for adding TX/RX handlers
 * into ordered list */

ieee80211_tx_handler ieee80211_tx_handlers[] =
{
	ieee80211_tx_h_check_assoc,
	ieee80211_tx_h_sequence,
	ieee80211_tx_h_ps_buf,
	ieee80211_tx_h_select_key,
	ieee80211_tx_h_michael_mic_add,
	ieee80211_tx_h_fragment,
776
	ieee80211_tx_h_encrypt,
777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954
	ieee80211_tx_h_rate_ctrl,
	ieee80211_tx_h_misc,
	ieee80211_tx_h_load_stats,
	NULL
};

/* actual transmit path */

/*
 * deal with packet injection down monitor interface
 * with Radiotap Header -- only called for monitor mode interface
 */
static ieee80211_txrx_result
__ieee80211_parse_tx_radiotap(
	struct ieee80211_txrx_data *tx,
	struct sk_buff *skb, struct ieee80211_tx_control *control)
{
	/*
	 * 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;
	struct ieee80211_hw_mode *mode = tx->local->hw.conf.mode;
	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len);

	/*
	 * default control situation for all injected packets
	 * FIXME: this does not suit all usage cases, expand to allow control
	 */

	control->retry_limit = 1; /* no retry */
	control->flags &= ~(IEEE80211_TXCTL_USE_RTS_CTS |
			    IEEE80211_TXCTL_USE_CTS_PROTECT);
	control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT |
			  IEEE80211_TXCTL_NO_ACK;
	control->antenna_sel_tx = 0; /* default to default antenna */

	/*
	 * for every radiotap entry that is present
	 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
	 * entries present, or -EINVAL on error)
	 */

	while (!ret) {
		int i, target_rate;

		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_RATE:
			/*
			 * radiotap rate u8 is in 500kbps units eg, 0x02=1Mbps
			 * ieee80211 rate int is in 100kbps units eg, 0x0a=1Mbps
			 */
			target_rate = (*iterator.this_arg) * 5;
			for (i = 0; i < mode->num_rates; i++) {
				struct ieee80211_rate *r = &mode->rates[i];

				if (r->rate > target_rate)
					continue;

				control->rate = r;

				if (r->flags & IEEE80211_RATE_PREAMBLE2)
					control->tx_rate = r->val2;
				else
					control->tx_rate = r->val;

				/* end on exact match */
				if (r->rate == target_rate)
					i = mode->num_rates;
			}
			break;

		case IEEE80211_RADIOTAP_ANTENNA:
			/*
			 * radiotap uses 0 for 1st ant, mac80211 is 1 for
			 * 1st ant
			 */
			control->antenna_sel_tx = (*iterator.this_arg) + 1;
			break;

		case IEEE80211_RADIOTAP_DBM_TX_POWER:
			control->power_level = *iterator.this_arg;
			break;

		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))
					return TXRX_DROP;

				skb_trim(skb, skb->len - FCS_LEN);
			}
			break;

		default:
			break;
		}
	}

	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
		return TXRX_DROP;

	/*
	 * remove the radiotap header
	 * iterator->max_length was sanity-checked against
	 * skb->len by iterator init
	 */
	skb_pull(skb, iterator.max_length);

	return TXRX_CONTINUE;
}

static ieee80211_txrx_result inline
__ieee80211_tx_prepare(struct ieee80211_txrx_data *tx,
		       struct sk_buff *skb,
		       struct net_device *dev,
		       struct ieee80211_tx_control *control)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	struct ieee80211_sub_if_data *sdata;
	ieee80211_txrx_result res = TXRX_CONTINUE;

	int hdrlen;

	memset(tx, 0, sizeof(*tx));
	tx->skb = skb;
	tx->dev = dev; /* use original interface */
	tx->local = local;
	tx->sdata = IEEE80211_DEV_TO_SUB_IF(dev);

	/*
	 * set defaults for things that can be set by
	 * injected radiotap headers
	 */
	control->power_level = local->hw.conf.power_level;
	control->antenna_sel_tx = local->hw.conf.antenna_sel_tx;

	/* process and remove the injection radiotap header */
	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	if (unlikely(sdata->type == IEEE80211_IF_TYPE_MNTR)) {
		if (__ieee80211_parse_tx_radiotap(tx, skb, control) ==
								TXRX_DROP) {
			return TXRX_DROP;
		}
		/*
		 * we removed the radiotap header after this point,
		 * we filled control with what we could use
		 * set to the actual ieee header now
		 */
		hdr = (struct ieee80211_hdr *) skb->data;
		res = TXRX_QUEUED; /* indication it was monitor packet */
	}

955 956
	tx->sta = sta_info_get(local, hdr->addr1);
	tx->fc = le16_to_cpu(hdr->frame_control);
957
	tx->u.tx.control = control;
958 959
	if (is_multicast_ether_addr(hdr->addr1)) {
		tx->flags &= ~IEEE80211_TXRXD_TXUNICAST;
960
		control->flags |= IEEE80211_TXCTL_NO_ACK;
961 962
	} else {
		tx->flags |= IEEE80211_TXRXD_TXUNICAST;
963
		control->flags &= ~IEEE80211_TXCTL_NO_ACK;
964 965 966 967 968 969 970 971
	}
	if (local->fragmentation_threshold < IEEE80211_MAX_FRAG_THRESHOLD &&
	    (tx->flags & IEEE80211_TXRXD_TXUNICAST) &&
	    skb->len + FCS_LEN > local->fragmentation_threshold &&
	    !local->ops->set_frag_threshold)
		tx->flags |= IEEE80211_TXRXD_FRAGMENTED;
	else
		tx->flags &= ~IEEE80211_TXRXD_FRAGMENTED;
972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998
	if (!tx->sta)
		control->flags |= IEEE80211_TXCTL_CLEAR_DST_MASK;
	else if (tx->sta->clear_dst_mask) {
		control->flags |= IEEE80211_TXCTL_CLEAR_DST_MASK;
		tx->sta->clear_dst_mask = 0;
	}
	hdrlen = ieee80211_get_hdrlen(tx->fc);
	if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
		u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
		tx->ethertype = (pos[0] << 8) | pos[1];
	}
	control->flags |= IEEE80211_TXCTL_FIRST_FRAGMENT;

	return res;
}

/* Device in tx->dev has a reference added; use dev_put(tx->dev) when
 * finished with it. */
static int inline ieee80211_tx_prepare(struct ieee80211_txrx_data *tx,
				       struct sk_buff *skb,
				       struct net_device *mdev,
				       struct ieee80211_tx_control *control)
{
	struct ieee80211_tx_packet_data *pkt_data;
	struct net_device *dev;

	pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
999
	dev = dev_get_by_index(&init_net, pkt_data->ifindex);
1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021
	if (unlikely(dev && !is_ieee80211_device(dev, mdev))) {
		dev_put(dev);
		dev = NULL;
	}
	if (unlikely(!dev))
		return -ENODEV;
	__ieee80211_tx_prepare(tx, skb, dev, control);
	return 0;
}

static int __ieee80211_tx(struct ieee80211_local *local, struct sk_buff *skb,
			  struct ieee80211_txrx_data *tx)
{
	struct ieee80211_tx_control *control = tx->u.tx.control;
	int ret, i;

	if (!ieee80211_qdisc_installed(local->mdev) &&
	    __ieee80211_queue_stopped(local, 0)) {
		netif_stop_queue(local->mdev);
		return IEEE80211_TX_AGAIN;
	}
	if (skb) {
1022 1023
		ieee80211_dump_frame(wiphy_name(local->hw.wiphy),
				     "TX to low-level driver", skb);
1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042
		ret = local->ops->tx(local_to_hw(local), skb, control);
		if (ret)
			return IEEE80211_TX_AGAIN;
		local->mdev->trans_start = jiffies;
		ieee80211_led_tx(local, 1);
	}
	if (tx->u.tx.extra_frag) {
		control->flags &= ~(IEEE80211_TXCTL_USE_RTS_CTS |
				    IEEE80211_TXCTL_USE_CTS_PROTECT |
				    IEEE80211_TXCTL_CLEAR_DST_MASK |
				    IEEE80211_TXCTL_FIRST_FRAGMENT);
		for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
			if (!tx->u.tx.extra_frag[i])
				continue;
			if (__ieee80211_queue_stopped(local, control->queue))
				return IEEE80211_TX_FRAG_AGAIN;
			if (i == tx->u.tx.num_extra_frag) {
				control->tx_rate = tx->u.tx.last_frag_hwrate;
				control->rate = tx->u.tx.last_frag_rate;
1043
				if (tx->flags & IEEE80211_TXRXD_TXPROBE_LAST_FRAG)
1044 1045 1046 1047 1048 1049 1050
					control->flags |=
						IEEE80211_TXCTL_RATE_CTRL_PROBE;
				else
					control->flags &=
						~IEEE80211_TXCTL_RATE_CTRL_PROBE;
			}

1051
			ieee80211_dump_frame(wiphy_name(local->hw.wiphy),
1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069
					     "TX to low-level driver",
					     tx->u.tx.extra_frag[i]);
			ret = local->ops->tx(local_to_hw(local),
					    tx->u.tx.extra_frag[i],
					    control);
			if (ret)
				return IEEE80211_TX_FRAG_AGAIN;
			local->mdev->trans_start = jiffies;
			ieee80211_led_tx(local, 1);
			tx->u.tx.extra_frag[i] = NULL;
		}
		kfree(tx->u.tx.extra_frag);
		tx->u.tx.extra_frag = NULL;
	}
	return IEEE80211_TX_OK;
}

static int ieee80211_tx(struct net_device *dev, struct sk_buff *skb,
1070
			struct ieee80211_tx_control *control)
1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct sta_info *sta;
	ieee80211_tx_handler *handler;
	struct ieee80211_txrx_data tx;
	ieee80211_txrx_result res = TXRX_DROP, res_prepare;
	int ret, i;

	WARN_ON(__ieee80211_queue_pending(local, control->queue));

	if (unlikely(skb->len < 10)) {
		dev_kfree_skb(skb);
		return 0;
	}

	res_prepare = __ieee80211_tx_prepare(&tx, skb, dev, control);

	if (res_prepare == TXRX_DROP) {
		dev_kfree_skb(skb);
		return 0;
	}

1093 1094 1095 1096 1097 1098
	/*
	 * key references are protected using RCU and this requires that
	 * we are in a read-site RCU section during receive processing
	 */
	rcu_read_lock();

1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124
	sta = tx.sta;
	tx.u.tx.mode = local->hw.conf.mode;

	if (res_prepare == TXRX_QUEUED) { /* if it was an injected packet */
		res = TXRX_CONTINUE;
	} else {
		for (handler = local->tx_handlers; *handler != NULL;
		     handler++) {
			res = (*handler)(&tx);
			if (res != TXRX_CONTINUE)
				break;
		}
	}

	skb = tx.skb; /* handlers are allowed to change skb */

	if (sta)
		sta_info_put(sta);

	if (unlikely(res == TXRX_DROP)) {
		I802_DEBUG_INC(local->tx_handlers_drop);
		goto drop;
	}

	if (unlikely(res == TXRX_QUEUED)) {
		I802_DEBUG_INC(local->tx_handlers_queued);
1125
		rcu_read_unlock();
1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179
		return 0;
	}

	if (tx.u.tx.extra_frag) {
		for (i = 0; i < tx.u.tx.num_extra_frag; i++) {
			int next_len, dur;
			struct ieee80211_hdr *hdr =
				(struct ieee80211_hdr *)
				tx.u.tx.extra_frag[i]->data;

			if (i + 1 < tx.u.tx.num_extra_frag) {
				next_len = tx.u.tx.extra_frag[i + 1]->len;
			} else {
				next_len = 0;
				tx.u.tx.rate = tx.u.tx.last_frag_rate;
				tx.u.tx.last_frag_hwrate = tx.u.tx.rate->val;
			}
			dur = ieee80211_duration(&tx, 0, next_len);
			hdr->duration_id = cpu_to_le16(dur);
		}
	}

retry:
	ret = __ieee80211_tx(local, skb, &tx);
	if (ret) {
		struct ieee80211_tx_stored_packet *store =
			&local->pending_packet[control->queue];

		if (ret == IEEE80211_TX_FRAG_AGAIN)
			skb = NULL;
		set_bit(IEEE80211_LINK_STATE_PENDING,
			&local->state[control->queue]);
		smp_mb();
		/* When the driver gets out of buffers during sending of
		 * fragments and calls ieee80211_stop_queue, there is
		 * a small window between IEEE80211_LINK_STATE_XOFF and
		 * IEEE80211_LINK_STATE_PENDING flags are set. If a buffer
		 * gets available in that window (i.e. driver calls
		 * ieee80211_wake_queue), we would end up with ieee80211_tx
		 * called with IEEE80211_LINK_STATE_PENDING. Prevent this by
		 * continuing transmitting here when that situation is
		 * possible to have happened. */
		if (!__ieee80211_queue_stopped(local, control->queue)) {
			clear_bit(IEEE80211_LINK_STATE_PENDING,
				  &local->state[control->queue]);
			goto retry;
		}
		memcpy(&store->control, control,
		       sizeof(struct ieee80211_tx_control));
		store->skb = skb;
		store->extra_frag = tx.u.tx.extra_frag;
		store->num_extra_frag = tx.u.tx.num_extra_frag;
		store->last_frag_hwrate = tx.u.tx.last_frag_hwrate;
		store->last_frag_rate = tx.u.tx.last_frag_rate;
1180 1181
		store->last_frag_rate_ctrl_probe =
			!!(tx.flags & IEEE80211_TXRXD_TXPROBE_LAST_FRAG);
1182
	}
1183
	rcu_read_unlock();
1184 1185 1186 1187 1188 1189 1190 1191 1192
	return 0;

 drop:
	if (skb)
		dev_kfree_skb(skb);
	for (i = 0; i < tx.u.tx.num_extra_frag; i++)
		if (tx.u.tx.extra_frag[i])
			dev_kfree_skb(tx.u.tx.extra_frag[i]);
	kfree(tx.u.tx.extra_frag);
1193
	rcu_read_unlock();
1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215
	return 0;
}

/* device xmit handlers */

int ieee80211_master_start_xmit(struct sk_buff *skb,
				struct net_device *dev)
{
	struct ieee80211_tx_control control;
	struct ieee80211_tx_packet_data *pkt_data;
	struct net_device *odev = NULL;
	struct ieee80211_sub_if_data *osdata;
	int headroom;
	int ret;

	/*
	 * copy control out of the skb so other people can use skb->cb
	 */
	pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
	memset(&control, 0, sizeof(struct ieee80211_tx_control));

	if (pkt_data->ifindex)
1216
		odev = dev_get_by_index(&init_net, pkt_data->ifindex);
1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241
	if (unlikely(odev && !is_ieee80211_device(odev, dev))) {
		dev_put(odev);
		odev = NULL;
	}
	if (unlikely(!odev)) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
		printk(KERN_DEBUG "%s: Discarded packet with nonexistent "
		       "originating device\n", dev->name);
#endif
		dev_kfree_skb(skb);
		return 0;
	}
	osdata = IEEE80211_DEV_TO_SUB_IF(odev);

	headroom = osdata->local->tx_headroom + IEEE80211_ENCRYPT_HEADROOM;
	if (skb_headroom(skb) < headroom) {
		if (pskb_expand_head(skb, headroom, 0, GFP_ATOMIC)) {
			dev_kfree_skb(skb);
			dev_put(odev);
			return 0;
		}
	}

	control.ifindex = odev->ifindex;
	control.type = osdata->type;
1242
	if (pkt_data->flags & IEEE80211_TXPD_REQ_TX_STATUS)
1243
		control.flags |= IEEE80211_TXCTL_REQ_TX_STATUS;
1244
	if (pkt_data->flags & IEEE80211_TXPD_DO_NOT_ENCRYPT)
1245
		control.flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
1246
	if (pkt_data->flags & IEEE80211_TXPD_REQUEUE)
1247 1248 1249
		control.flags |= IEEE80211_TXCTL_REQUEUE;
	control.queue = pkt_data->queue;

1250
	ret = ieee80211_tx(odev, skb, &control);
1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262
	dev_put(odev);

	return ret;
}

int ieee80211_monitor_start_xmit(struct sk_buff *skb,
				 struct net_device *dev)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_tx_packet_data *pkt_data;
	struct ieee80211_radiotap_header *prthdr =
		(struct ieee80211_radiotap_header *)skb->data;
1263
	u16 len_rthdr;
1264

1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278
	/* 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 */
1279 1280 1281 1282 1283

	skb->dev = local->mdev;

	pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
	memset(pkt_data, 0, sizeof(*pkt_data));
1284
	/* needed because we set skb device to master */
1285
	pkt_data->ifindex = dev->ifindex;
1286

1287
	pkt_data->flags |= IEEE80211_TXPD_DO_NOT_ENCRYPT;
1288 1289 1290 1291 1292 1293 1294

	/*
	 * 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
	 */
1295
	skb_set_mac_header(skb, len_rthdr);
1296
	/*
1297 1298
	 * 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
1299
	 */
1300 1301
	skb_set_network_header(skb, len_rthdr);
	skb_set_transport_header(skb, len_rthdr);
1302

1303 1304
	/* pass the radiotap header up to the next stage intact */
	dev_queue_xmit(skb);
1305
	return NETDEV_TX_OK;
1306 1307 1308 1309

fail:
	dev_kfree_skb(skb);
	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337
}

/**
 * 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)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct ieee80211_tx_packet_data *pkt_data;
	struct ieee80211_sub_if_data *sdata;
	int ret = 1, head_need;
	u16 ethertype, hdrlen, fc;
	struct ieee80211_hdr hdr;
	const u8 *encaps_data;
	int encaps_len, skip_header_bytes;
1338
	int nh_pos, h_pos;
1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357
	struct sta_info *sta;

	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	if (unlikely(skb->len < ETH_HLEN)) {
		printk(KERN_DEBUG "%s: short skb (len=%d)\n",
		       dev->name, skb->len);
		ret = 0;
		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];
	/* TODO: handling for 802.1x authorized/unauthorized port */
	fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA;

1358 1359 1360
	switch (sdata->type) {
	case IEEE80211_IF_TYPE_AP:
	case IEEE80211_IF_TYPE_VLAN:
1361 1362 1363 1364 1365 1366
		fc |= IEEE80211_FCTL_FROMDS;
		/* 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;
1367 1368
		break;
	case IEEE80211_IF_TYPE_WDS:
1369 1370 1371 1372 1373 1374 1375
		fc |= IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS;
		/* 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;
1376 1377
		break;
	case IEEE80211_IF_TYPE_STA:
1378 1379 1380 1381 1382 1383
		fc |= IEEE80211_FCTL_TODS;
		/* BSSID SA DA */
		memcpy(hdr.addr1, sdata->u.sta.bssid, ETH_ALEN);
		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
		memcpy(hdr.addr3, skb->data, ETH_ALEN);
		hdrlen = 24;
1384 1385
		break;
	case IEEE80211_IF_TYPE_IBSS:
1386 1387 1388 1389 1390
		/* DA SA BSSID */
		memcpy(hdr.addr1, skb->data, ETH_ALEN);
		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
		memcpy(hdr.addr3, sdata->u.sta.bssid, ETH_ALEN);
		hdrlen = 24;
1391 1392
		break;
	default:
1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474
		ret = 0;
		goto fail;
	}

	/* receiver is QoS enabled, use a QoS type frame */
	sta = sta_info_get(local, hdr.addr1);
	if (sta) {
		if (sta->flags & WLAN_STA_WME) {
			fc |= IEEE80211_STYPE_QOS_DATA;
			hdrlen += 2;
		}
		sta_info_put(sta);
	}

	hdr.frame_control = cpu_to_le16(fc);
	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;

	/* TODO: implement support for fragments so that there is no need to
	 * reallocate and copy payload; it might be enough to support one
	 * extra fragment that would be copied in the beginning of the frame
	 * data.. anyway, it would be nice to include this into skb structure
	 * somehow
	 *
	 * There are few options for this:
	 * use skb->cb as an extra space for 802.11 header
	 * allocate new buffer if not enough headroom
	 * make sure that there is enough headroom in every skb by increasing
	 * build in headroom in __dev_alloc_skb() (linux/skbuff.h) and
	 * alloc_skb() (net/core/skbuff.c)
	 */
	head_need = hdrlen + encaps_len + local->tx_headroom;
	head_need -= skb_headroom(skb);

	/* We are going to modify skb data, so make a copy of it if happens to
	 * be cloned. This could happen, e.g., with Linux bridge code passing
	 * us broadcast frames. */

	if (head_need > 0 || skb_cloned(skb)) {
#if 0
		printk(KERN_DEBUG "%s: need to reallocate buffer for %d bytes "
		       "of headroom\n", dev->name, head_need);
#endif

		if (skb_cloned(skb))
			I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
		else
			I802_DEBUG_INC(local->tx_expand_skb_head);
		/* Since we have to reallocate the buffer, make sure that there
		 * is enough room for possible WEP IV/ICV and TKIP (8 bytes
		 * before payload and 12 after). */
		if (pskb_expand_head(skb, (head_need > 0 ? head_need + 8 : 8),
				     12, GFP_ATOMIC)) {
			printk(KERN_DEBUG "%s: failed to reallocate TX buffer"
			       "\n", dev->name);
			goto fail;
		}
	}

	if (encaps_data) {
		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
		nh_pos += encaps_len;
		h_pos += encaps_len;
	}
1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488

	if (fc & IEEE80211_STYPE_QOS_DATA) {
		__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);

1489 1490 1491 1492 1493 1494 1495 1496
	nh_pos += hdrlen;
	h_pos += hdrlen;

	pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
	memset(pkt_data, 0, sizeof(struct ieee80211_tx_packet_data));
	pkt_data->ifindex = dev->ifindex;

	skb->dev = local->mdev;
1497 1498
	dev->stats.tx_packets++;
	dev->stats.tx_bytes += skb->len;
1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518