[MAC80211]: split TX path into own file

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 1869 insertions, 0 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
new file mode 100644
index 000000000000..dc128b412eab
--- /dev/null
+++ b/net/mac80211/tx.c
@@ -0,0 +1,1869 @@
+/*
+ * 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>
+#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;
+
+	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)
+		printk(" A1=" MAC_FMT, MAC_ARG(hdr->addr1));
+	if (hdrlen >= 16)
+		printk(" A2=" MAC_FMT, MAC_ARG(hdr->addr2));
+	if (hdrlen >= 24)
+		printk(" A3=" MAC_FMT, MAC_ARG(hdr->addr3));
+	if (hdrlen >= 30)
+		printk(" A4=" MAC_FMT, MAC_ARG(hdr->addr4));
+	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,
+				       local->short_preamble);
+
+	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,
+						txrate->rate, erp,
+						local->short_preamble);
+	}
+
+	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;
+
+	if (tx->u.tx.ps_buffered)
+		return TXRX_CONTINUE;
+
+	sta_flags = tx->sta ? tx->sta->flags : 0;
+
+	if (likely(tx->u.tx.unicast)) {
+		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
+			printk(KERN_DEBUG "%s: dropped data frame to not "
+			       "associated station " MAC_FMT "\n",
+			       tx->dev->name, MAC_ARG(hdr->addr1));
+#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->local->allow_broadcast_always &&
+			     tx->sdata->type != IEEE80211_IF_TYPE_IBSS)) {
+			/*
+			 * No associated STAs - no need to send multicast
+			 * frames.
+			 */
+			return TXRX_DROP;
+		}
+		return TXRX_CONTINUE;
+	}
+
+	if (unlikely(!tx->u.tx.mgmt_interface && tx->sdata->ieee802_1x &&
+		     !(sta_flags & WLAN_STA_AUTHORIZED))) {
+#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
+		printk(KERN_DEBUG "%s: dropped frame to " MAC_FMT
+		       " (unauthorized port)\n", tx->dev->name,
+		       MAC_ARG(hdr->addr1));
+#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;
+
+	read_lock(&local->sub_if_lock);
+	list_for_each_entry(sdata, &local->sub_if_list, list) {
+		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);
+	}
+	read_unlock(&local->sub_if_lock);
+
+	spin_lock_bh(&local->sta_lock);
+	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);
+	}
+	spin_unlock_bh(&local->sta_lock);
+
+	local->total_ps_buffered = total;
+	printk(KERN_DEBUG "%s: PS buffers full - purged %d frames\n",
+	       local->mdev->name, purged);
+}
+
+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;
+
+	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
+		printk(KERN_DEBUG "STA " MAC_FMT " aid %d: PS buffer (entries "
+		       "before %d)\n",
+		       MAC_ARG(sta->addr), sta->aid,
+		       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()) {
+				printk(KERN_DEBUG "%s: STA " MAC_FMT " TX "
+				       "buffer full - dropping oldest frame\n",
+				       tx->dev->name, MAC_ARG(sta->addr));
+			}
+			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)) {
+		printk(KERN_DEBUG "%s: STA " MAC_FMT " in PS mode, but pspoll "
+		       "set -> send frame\n", tx->dev->name,
+		       MAC_ARG(sta->addr));
+	}
+#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)
+{
+	if (unlikely(tx->u.tx.ps_buffered))
+		return TXRX_CONTINUE;
+
+	if (tx->u.tx.unicast)
+		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)
+{
+	if (tx->sta)
+		tx->u.tx.control->key_idx = tx->sta->key_idx_compression;
+	else
+		tx->u.tx.control->key_idx = HW_KEY_IDX_INVALID;
+
+	if (unlikely(tx->u.tx.control->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT))
+		tx->key = NULL;
+	else if (tx->sta && tx->sta->key)
+		tx->key = tx->sta->key;
+	else if (tx->sdata->default_key)
+		tx->key = tx->sdata->default_key;
+	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;
+	} else
+		tx->key = NULL;
+
+	if (tx->key) {
+		tx->key->tx_rx_count++;
+		if (unlikely(tx->local->key_tx_rx_threshold &&
+			     tx->key->tx_rx_count >
+			     tx->local->key_tx_rx_threshold)) {
+			ieee80211_key_threshold_notify(tx->dev, tx->key,
+						       tx->sta);
+		}
+	}
+
+	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;
+
+	if (!tx->fragmented)
+		return TXRX_CONTINUE;
+
+	first = tx->skb;
+
+	hdrlen = ieee80211_get_hdrlen(tx->fc);
+	payload_len = first->len - hdrlen;
+	per_fragm = frag_threshold - hdrlen - FCS_LEN;
+	num_fragm = (payload_len + per_fragm - 1) / per_fragm;
+
+	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 int wep_encrypt_skb(struct ieee80211_txrx_data *tx, struct sk_buff *skb)
+{
+	if (tx->key->force_sw_encrypt) {
+		if (ieee80211_wep_encrypt(tx->local, skb, tx->key))
+			return -1;
+	} else {
+		tx->u.tx.control->key_idx = tx->key->hw_key_idx;
+		if (tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) {
+			if (ieee80211_wep_add_iv(tx->local, skb, tx->key) ==
+			    NULL)
+				return -1;
+		}
+	}
+	return 0;
+}
+
+static ieee80211_txrx_result
+ieee80211_tx_h_wep_encrypt(struct ieee80211_txrx_data *tx)
+{
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
+	u16 fc;
+
+	fc = le16_to_cpu(hdr->frame_control);
+
+	if (!tx->key || tx->key->alg != ALG_WEP ||
+	    ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
+	     ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
+	      (fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)))
+		return TXRX_CONTINUE;
+
+	tx->u.tx.control->iv_len = WEP_IV_LEN;
+	tx->u.tx.control->icv_len = WEP_ICV_LEN;
+	ieee80211_tx_set_iswep(tx);
+
+	if (wep_encrypt_skb(tx, tx->skb) < 0) {
+		I802_DEBUG_INC(tx->local->tx_handlers_drop_wep);
+		return TXRX_DROP;
+	}
+
+	if (tx->u.tx.extra_frag) {
+		int i;
+		for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
+			if (wep_encrypt_skb(tx, tx->u.tx.extra_frag[i]) < 0) {
+				I802_DEBUG_INC(tx->local->
+					       tx_handlers_drop_wep);
+				return TXRX_DROP;
+			}
+		}
+	}
+
+	return TXRX_CONTINUE;
+}
+
+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.mgmt_data = tx->sdata &&
+		tx->sdata->type == IEEE80211_IF_TYPE_MGMT;
+	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;
+		tx->u.tx.probe_last_frag = 1;
+		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 &&
+	    tx->sdata->use_protection && tx->fragmented &&
+	    extra.nonerp) {
+		tx->u.tx.last_frag_rate = tx->u.tx.rate;
+		tx->u.tx.probe_last_frag = extra.probe ? 1 : 0;
+
+		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;
+	if ((tx->u.tx.rate->flags & IEEE80211_RATE_PREAMBLE2) &&
+	    tx->local->short_preamble &&
+	    (!tx->sta || (tx->sta->flags & WLAN_STA_SHORT_PREAMBLE))) {
+		tx->u.tx.short_preamble = 1;
+		tx->u.tx.control->tx_rate = tx->u.tx.rate->val2;
+	}
+
+	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;
+	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;
+			control->retry_limit =
+				tx->local->long_retry_limit;
+		} else {
+			control->retry_limit =
+				tx->local->short_retry_limit;
+		}
+	} else {
+		control->retry_limit = 1;
+	}
+
+	if (tx->fragmented) {
+		/* 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) &&
+	    tx->u.tx.unicast && tx->sdata->use_protection &&
+	    !(control->flags & IEEE80211_TXCTL_USE_RTS_CTS))
+		control->flags |= IEEE80211_TXCTL_USE_CTS_PROTECT;
+
+	/* 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),
+				 tx->fragmented ? tx->u.tx.extra_frag[0]->len :
+				 0);
+	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;
+			}
+		}
+	}
+
+	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_ATHEROS_TURBO ||
+	    mode->mode == MODE_ATHEROS_TURBOG ||
+	    (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,
+	ieee80211_tx_h_tkip_encrypt,
+	ieee80211_tx_h_ccmp_encrypt,
+	ieee80211_tx_h_wep_encrypt,
+	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->key_idx = -1; /* no encryption key */
+	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);
+	tx->sta = sta_info_get(local, hdr->addr1);
+	tx->fc = le16_to_cpu(hdr->frame_control);
+
+	/*
+	 * 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;
+	if (local->sta_antenna_sel != STA_ANTENNA_SEL_AUTO && tx->sta)
+		control->antenna_sel_tx = tx->sta->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 */
+	}
+
+	tx->u.tx.control = control;
+	tx->u.tx.unicast = !is_multicast_ether_addr(hdr->addr1);
+	if (is_multicast_ether_addr(hdr->addr1))
+		control->flags |= IEEE80211_TXCTL_NO_ACK;
+	else
+		control->flags &= ~IEEE80211_TXCTL_NO_ACK;
+	tx->fragmented = local->fragmentation_threshold <
+		IEEE80211_MAX_FRAG_THRESHOLD && tx->u.tx.unicast &&
+		skb->len + FCS_LEN > local->fragmentation_threshold &&
+		(!local->ops->set_frag_threshold);
+	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;
+	dev = dev_get_by_index(pkt_data->ifindex);
+	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) {
+		ieee80211_dump_frame(local->mdev->name, "TX to low-level driver", skb);
+		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;
+				if (tx->u.tx.probe_last_frag)
+					control->flags |=
+						IEEE80211_TXCTL_RATE_CTRL_PROBE;
+				else
+					control->flags &=
+						~IEEE80211_TXCTL_RATE_CTRL_PROBE;
+			}
+
+			ieee80211_dump_frame(local->mdev->name,
+					     "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,
+			struct ieee80211_tx_control *control, int mgmt)
+{
+	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;
+	}
+
+	sta = tx.sta;
+	tx.u.tx.mgmt_interface = mgmt;
+	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);
+		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;
+		store->last_frag_rate_ctrl_probe = tx.u.tx.probe_last_frag;
+	}
+	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);
+	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)
+		odev = dev_get_by_index(pkt_data->ifindex);
+	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;
+	if (pkt_data->req_tx_status)
+		control.flags |= IEEE80211_TXCTL_REQ_TX_STATUS;
+	if (pkt_data->do_not_encrypt)
+		control.flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
+	if (pkt_data->requeue)
+		control.flags |= IEEE80211_TXCTL_REQUEUE;
+	control.queue = pkt_data->queue;
+
+	ret = ieee80211_tx(odev, skb, &control,
+			   control.type == IEEE80211_IF_TYPE_MGMT);
+	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;
+	u16 len;
+
+	/*
+	 * there must be a radiotap header at the
+	 * start in this case
+	 */
+	if (unlikely(prthdr->it_version)) {
+		/* only version 0 is supported */
+		dev_kfree_skb(skb);
+		return NETDEV_TX_OK;
+	}
+
+	skb->dev = local->mdev;
+
+	pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
+	memset(pkt_data, 0, sizeof(*pkt_data));
+	pkt_data->ifindex = dev->ifindex;
+	pkt_data->mgmt_iface = 0;
+	pkt_data->do_not_encrypt = 1;
+
+	/* above needed because we set skb device to master */
+
+	/*
+	 * 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
+	 */
+	len = le16_to_cpu(get_unaligned(&prthdr->it_len));
+	skb_set_mac_header(skb, len);
+	skb_set_network_header(skb, len + sizeof(struct ieee80211_hdr));
+	skb_set_transport_header(skb, len + sizeof(struct ieee80211_hdr));
+
+	/*
+	 * pass the radiotap header up to
+	 * the next stage intact
+	 */
+	dev_queue_xmit(skb);
+
+	return NETDEV_TX_OK;
+}
+
+/**
+ * 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;
+	int nh_pos, h_pos, no_encrypt = 0;
+	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;
+
+	if (likely(sdata->type == IEEE80211_IF_TYPE_AP ||
+		   sdata->type == IEEE80211_IF_TYPE_VLAN)) {
+		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;
+	} else if (sdata->type == IEEE80211_IF_TYPE_WDS) {
+		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;
+	} else if (sdata->type == IEEE80211_IF_TYPE_STA) {
+		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;
+	} else if (sdata->type == IEEE80211_IF_TYPE_IBSS) {
+		/* 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;
+	} else {
+		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;
+	}
+	memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
+	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;
+	pkt_data->mgmt_iface = (sdata->type == IEEE80211_IF_TYPE_MGMT);
+	pkt_data->do_not_encrypt = no_encrypt;
+
+	skb->dev = local->mdev;
+	sdata->stats.tx_packets++;
+	sdata->stats.tx_bytes += skb->len;
+
+	/* 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);
+
+	dev->trans_start = jiffies;
+	dev_queue_xmit(skb);
+
+	return 0;
+
+ fail:
+	if (!ret)
+		dev_kfree_skb(skb);
+
+	return ret;
+}
+
+/*
+ * This is the transmit routine for the 802.11 type interfaces
+ * called by upper layers of the linux networking
+ * stack when it has a frame to transmit
+ */
+int ieee80211_mgmt_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_tx_packet_data *pkt_data;
+	struct ieee80211_hdr *hdr;
+	u16 fc;
+
+	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+	if (skb->len < 10) {
+		dev_kfree_skb(skb);
+		return 0;
+	}
+
+	if (skb_headroom(skb) < sdata->local->tx_headroom) {
+		if (pskb_expand_head(skb, sdata->local->tx_headroom,
+				     0, GFP_ATOMIC)) {
+			dev_kfree_skb(skb);
+			return 0;
+		}
+	}
+
+	hdr = (struct ieee80211_hdr *) skb->data;
+	fc = le16_to_cpu(hdr->frame_control);
+
+	pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
+	memset(pkt_data, 0, sizeof(struct ieee80211_tx_packet_data));
+	pkt_data->ifindex = sdata->dev->ifindex;
+	pkt_data->mgmt_iface = (sdata->type == IEEE80211_IF_TYPE_MGMT);
+
+	skb->priority = 20; /* use hardcoded priority for mgmt TX queue */
+	skb->dev = sdata->local->mdev;
+
+	/*
+	 * We're using the protocol field of the the frame control header
+	 * to request TX callback for hostapd. BIT(1) is checked.
+	 */
+	if ((fc & BIT(1)) == BIT(1)) {
+		pkt_data->req_tx_status = 1;
+		fc &= ~BIT(1);
+		hdr->frame_control = cpu_to_le16(fc);
+	}
+
+	pkt_data->do_not_encrypt = !(fc & IEEE80211_FCTL_PROTECTED);
+
+	sdata->stats.tx_packets++;
+	sdata->stats.tx_bytes += skb->len;
+
+	dev_queue_xmit(skb);
+
+	return 0;
+}
+
+/* helper functions for pending packets for when queues are stopped */
+
+void ieee80211_clear_tx_pending(struct ieee80211_local *local)
+{
+	int i, j;
+	struct ieee80211_tx_stored_packet *store;
+
+	for (i = 0; i < local->hw.queues; i++) {
+		if (!__ieee80211_queue_pending(local, i))
+			continue;
+		store = &local->pending_packet[i];
+		kfree_skb(store->skb);
+		for (j = 0; j < store->num_extra_frag; j++)
+			kfree_skb(store->extra_frag[j]);
+		kfree(store->extra_frag);
+		clear_bit(IEEE80211_LINK_STATE_PENDING, &local->state[i]);
+	}
+}
+
+void ieee80211_tx_pending(unsigned long data)
+{
+	struct ieee80211_local *local = (struct ieee80211_local *)data;
+	struct net_device *dev = local->mdev;
+	struct ieee80211_tx_stored_packet *store;
+	struct ieee80211_txrx_data tx;
+	int i, ret, reschedule = 0;
+
+	netif_tx_lock_bh(dev);
+	for (i = 0; i < local->hw.queues; i++) {
+		if (__ieee80211_queue_stopped(local, i))
+			continue;
+		if (!__ieee80211_queue_pending(local, i)) {
+			reschedule = 1;
+			continue;
+		}
+		store = &local->pending_packet[i];
+		tx.u.tx.control = &store->control;
+		tx.u.tx.extra_frag = store->extra_frag;
+		tx.u.tx.num_extra_frag = store->num_extra_frag;
+		tx.u.tx.last_frag_hwrate = store->last_frag_hwrate;
+		tx.u.tx.last_frag_rate = store->last_frag_rate;
+		tx.u.tx.probe_last_frag = store->last_frag_rate_ctrl_probe;
+		ret = __ieee80211_tx(local, store->skb, &tx);
+		if (ret) {
+			if (ret == IEEE80211_TX_FRAG_AGAIN)
+				store->skb = NULL;
+		} else {
+			clear_bit(IEEE80211_LINK_STATE_PENDING,
+				  &local->state[i]);
+			reschedule = 1;
+		}
+	}
+	netif_tx_unlock_bh(dev);
+	if (reschedule) {
+		if (!ieee80211_qdisc_installed(dev)) {
+			if (!__ieee80211_queue_stopped(local, 0))
+				netif_wake_queue(dev);
+		} else
+			netif_schedule(dev);
+	}
+}
+
+/* functions for drivers to get certain frames */
+
+static void ieee80211_beacon_add_tim(struct ieee80211_local *local,
+				     struct ieee80211_if_ap *bss,
+				     struct sk_buff *skb)
+{
+	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. */
+	spin_lock_bh(&local->sta_lock);
+	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)
+		bss->dtim_count = bss->dtim_period - 1;
+	else
+		bss->dtim_count--;
+
+	tim = pos = (u8 *) skb_put(skb, 6);
+	*pos++ = WLAN_EID_TIM;
+	*pos++ = 4;
+	*pos++ = bss->dtim_count;
+	*pos++ = bss->dtim_period;
+
+	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 */
+	}
+	spin_unlock_bh(&local->sta_lock);
+}
+
+struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw, int if_id,
+				     struct ieee80211_tx_control *control)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+	struct sk_buff *skb;
+	struct net_device *bdev;
+	struct ieee80211_sub_if_data *sdata = NULL;
+	struct ieee80211_if_ap *ap = NULL;
+	struct ieee80211_rate *rate;
+	struct rate_control_extra extra;
+	u8 *b_head, *b_tail;
+	int bh_len, bt_len;
+
+	bdev = dev_get_by_index(if_id);
+	if (bdev) {
+		sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
+		ap = &sdata->u.ap;
+		dev_put(bdev);
+	}
+
+	if (!ap || sdata->type != IEEE80211_IF_TYPE_AP ||
+	    !ap->beacon_head) {
+#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
+		if (net_ratelimit())
+			printk(KERN_DEBUG "no beacon data avail for idx=%d "
+			       "(%s)\n", if_id, bdev ? bdev->name : "N/A");
+#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
+		return NULL;
+	}
+
+	/* Assume we are generating the normal beacon locally */
+	b_head = ap->beacon_head;
+	b_tail = ap->beacon_tail;
+	bh_len = ap->beacon_head_len;
+	bt_len = ap->beacon_tail_len;
+
+	skb = dev_alloc_skb(local->tx_headroom +
+		bh_len + bt_len + 256 /* maximum TIM len */);
+	if (!skb)
+		return NULL;
+
+	skb_reserve(skb, local->tx_headroom);
+	memcpy(skb_put(skb, bh_len), b_head, bh_len);
+
+	ieee80211_include_sequence(sdata, (struct ieee80211_hdr *)skb->data);
+
+	ieee80211_beacon_add_tim(local, ap, skb);
+
+	if (b_tail) {
+		memcpy(skb_put(skb, bt_len), b_tail, bt_len);
+	}
+
+	if (control) {
+		memset(&extra, 0, sizeof(extra));
+		extra.mode = local->oper_hw_mode;
+
+		rate = rate_control_get_rate(local, local->mdev, skb, &extra);
+		if (!rate) {
+			if (net_ratelimit()) {
+				printk(KERN_DEBUG "%s: ieee80211_beacon_get: no rate "
+				       "found\n", local->mdev->name);
+			}
+			dev_kfree_skb(skb);
+			return NULL;
+		}
+
+		control->tx_rate = (local->short_preamble &&
+				    (rate->flags & IEEE80211_RATE_PREAMBLE2)) ?
+			rate->val2 : rate->val;
+		control->antenna_sel_tx = local->hw.conf.antenna_sel_tx;
+		control->power_level = local->hw.conf.power_level;
+		control->flags |= IEEE80211_TXCTL_NO_ACK;
+		control->retry_limit = 1;
+		control->flags |= IEEE80211_TXCTL_CLEAR_DST_MASK;
+	}
+
+	ap->num_beacons++;
+	return skb;
+}
+EXPORT_SYMBOL(ieee80211_beacon_get);
+
+void ieee80211_rts_get(struct ieee80211_hw *hw,
+		       const void *frame, size_t frame_len,
+		       const struct ieee80211_tx_control *frame_txctl,
+		       struct ieee80211_rts *rts)
+{
+	const struct ieee80211_hdr *hdr = frame;
+	u16 fctl;
+
+	fctl = IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS;
+	rts->frame_control = cpu_to_le16(fctl);
+	rts->duration = ieee80211_rts_duration(hw, frame_len, frame_txctl);
+	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
+	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
+}
+EXPORT_SYMBOL(ieee80211_rts_get);
+
+void ieee80211_ctstoself_get(struct ieee80211_hw *hw,
+			     const void *frame, size_t frame_len,
+			     const struct ieee80211_tx_control *frame_txctl,
+			     struct ieee80211_cts *cts)
+{
+	const struct ieee80211_hdr *hdr = frame;
+	u16 fctl;
+
+	fctl = IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS;
+	cts->frame_control = cpu_to_le16(fctl);
+	cts->duration = ieee80211_ctstoself_duration(hw, frame_len, frame_txctl);
+	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
+}
+EXPORT_SYMBOL(ieee80211_ctstoself_get);
+
+struct sk_buff *
+ieee80211_get_buffered_bc(struct ieee80211_hw *hw, int if_id,
+			  struct ieee80211_tx_control *control)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+	struct sk_buff *skb;
+	struct sta_info *sta;
+	ieee80211_tx_handler *handler;
+	struct ieee80211_txrx_data tx;
+	ieee80211_txrx_result res = TXRX_DROP;
+	struct net_device *bdev;
+	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_if_ap *bss = NULL;
+
+	bdev = dev_get_by_index(if_id);
+	if (bdev) {
+		sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
+		bss = &sdata->u.ap;
+		dev_put(bdev);
+	}
+	if (!bss || sdata->type != IEEE80211_IF_TYPE_AP || !bss->beacon_head)
+		return NULL;
+
+	if (bss->dtim_count != 0)
+		return NULL; /* send buffered bc/mc only after DTIM beacon */
+	memset(control, 0, sizeof(*control));
+	while (1) {
+		skb = skb_dequeue(&bss->ps_bc_buf);
+		if (!skb)
+			return NULL;
+		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);
+		}
+
+		if (ieee80211_tx_prepare(&tx, skb, local->mdev, control) == 0)
+			break;
+		dev_kfree_skb_any(skb);
+	}
+	sta = tx.sta;
+	tx.u.tx.ps_buffered = 1;
+
+	for (handler = local->tx_handlers; *handler != NULL; handler++) {
+		res = (*handler)(&tx);
+		if (res == TXRX_DROP || res == TXRX_QUEUED)
+			break;
+	}
+	dev_put(tx.dev);
+	skb = tx.skb; /* handlers are allowed to change skb */
+
+	if (res == TXRX_DROP) {
+		I802_DEBUG_INC(local->tx_handlers_drop);
+		dev_kfree_skb(skb);
+		skb = NULL;
+	} else if (res == TXRX_QUEUED) {
+		I802_DEBUG_INC(local->tx_handlers_queued);
+		skb = NULL;
+	}
+
+	if (sta)
+		sta_info_put(sta);
+
+	return skb;
+}
+EXPORT_SYMBOL(ieee80211_get_buffered_bc);