tx.c 61.5 KB
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/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 *
 * Transmit and frame generation functions.
 */

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

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

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

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

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

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

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

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

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

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

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	return cpu_to_le16(dur);
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}

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

/* tx handlers */

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

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

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

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	return TX_CONTINUE;
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}

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

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

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

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

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

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

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

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

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

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

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

	return 1;
}

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

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

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

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

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

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

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	if (!tx->key || !(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
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		tx->skb->do_not_encrypt = 1;
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	return TX_CONTINUE;
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}

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

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

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

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

	if (txrc.reported_rate.idx < 0)
		txrc.reported_rate = info->control.rates[0];
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	if (tx->sta)
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		tx->sta->last_tx_rate = txrc.reported_rate;
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	if (unlikely(!info->control.rates[0].count))
		info->control.rates[0].count = 1;
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	if (is_multicast_ether_addr(hdr->addr1)) {
		/*
		 * XXX: verify the rate is in the basic rateset
		 */
		return TX_CONTINUE;
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	}

568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592
	/*
	 * set up the RTS/CTS rate as the fastest basic rate
	 * that is not faster than the data rate
	 *
	 * XXX: Should this check all retry rates?
	 */
	if (!(info->control.rates[0].flags & IEEE80211_TX_RC_MCS)) {
		s8 baserate = 0;

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

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

		info->control.rts_cts_rate_idx = baserate;
593 594
	}

595 596 597 598 599 600 601 602 603 604 605 606 607 608
	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
		/*
		 * make sure there's no valid rate following
		 * an invalid one, just in case drivers don't
		 * take the API seriously to stop at -1.
		 */
		if (inval) {
			info->control.rates[i].idx = -1;
			continue;
		}
		if (info->control.rates[i].idx < 0) {
			inval = true;
			continue;
		}
609

610 611 612 613 614 615 616 617
		/*
		 * For now assume MCS is already set up correctly, this
		 * needs to be fixed.
		 */
		if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) {
			WARN_ON(info->control.rates[i].idx > 76);
			continue;
		}
618

619 620 621 622
		/* set up RTS protection if desired */
		if (rts)
			info->control.rates[i].flags |=
				IEEE80211_TX_RC_USE_RTS_CTS;
623

624
		/* RC is busted */
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		if (WARN_ON_ONCE(info->control.rates[i].idx >=
				 sband->n_bitrates)) {
627 628
			info->control.rates[i].idx = -1;
			continue;
629
		}
630

631 632 633 634 635 636 637 638 639 640 641 642 643
		rate = &sband->bitrates[info->control.rates[i].idx];

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

		/* set up G protection */
		if (!rts && tx->sdata->vif.bss_conf.use_cts_prot &&
		    rate->flags & IEEE80211_RATE_ERP_G)
			info->control.rates[i].flags |=
				IEEE80211_TX_RC_USE_CTS_PROTECT;
644 645
	}

646 647 648 649 650 651 652 653
	return TX_CONTINUE;
}

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

654
	if (tx->sta)
655
		info->control.sta = &tx->sta->sta;
656 657 658 659

	return TX_CONTINUE;
}

660 661 662 663 664 665 666 667 668
static ieee80211_tx_result debug_noinline
ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
	u16 *seq;
	u8 *qc;
	int tid;

669 670 671 672 673 674 675 676
	/*
	 * Packet injection may want to control the sequence
	 * number, if we have no matching interface then we
	 * neither assign one ourselves nor ask the driver to.
	 */
	if (unlikely(!info->control.vif))
		return TX_CONTINUE;

677 678 679 680 681 682
	if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
		return TX_CONTINUE;

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

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	/*
	 * Anything but QoS data that has a sequence number field
	 * (is long enough) gets a sequence number from the global
	 * counter.
	 */
688
	if (!ieee80211_is_data_qos(hdr->frame_control)) {
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689
		/* driver should assign sequence number */
690
		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
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691 692 693 694
		/* for pure STA mode without beacons, we can do it */
		hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
		tx->sdata->sequence_number += 0x10;
		tx->sdata->sequence_number &= IEEE80211_SCTL_SEQ;
695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719
		return TX_CONTINUE;
	}

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

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

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

	hdr->seq_ctrl = cpu_to_le16(*seq);

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

	return TX_CONTINUE;
}

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

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

	while (rem) {
		int fraglen = per_fragm;

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

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

		pos += fraglen;
	}

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

767
static ieee80211_tx_result debug_noinline
768 769
ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
{
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	struct sk_buff *skb = tx->skb;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ieee80211_hdr *hdr = (void *)skb->data;
773
	int frag_threshold = tx->local->hw.wiphy->frag_threshold;
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	int hdrlen;
	int fragnum;
776 777 778 779

	if (!(tx->flags & IEEE80211_TX_FRAGMENTED))
		return TX_CONTINUE;

780 781
	/*
	 * Warn when submitting a fragmented A-MPDU frame and drop it.
782 783
	 * This scenario is handled in __ieee80211_tx_prepare but extra
	 * caution taken here as fragmented ampdu may cause Tx stop.
784
	 */
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785
	if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
786 787
		return TX_DROP;

788
	hdrlen = ieee80211_hdrlen(hdr->frame_control);
789

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790 791 792
	/* internal error, why is TX_FRAGMENTED set? */
	if (WARN_ON(skb->len <= frag_threshold))
		return TX_DROP;
793

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794 795 796 797 798 799 800 801 802 803
	/*
	 * Now fragment the frame. This will allocate all the fragments and
	 * chain them (using skb as the first fragment) to skb->next.
	 * During transmission, we will remove the successfully transmitted
	 * fragments from this list. When the low-level driver rejects one
	 * of the fragments then we will simply pretend to accept the skb
	 * but store it away as pending.
	 */
	if (ieee80211_fragment(tx->local, skb, hdrlen, frag_threshold))
		return TX_DROP;
804

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805 806 807 808 809
	/* update duration/seq/flags of fragments */
	fragnum = 0;
	do {
		int next_len;
		const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
810

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811 812
		hdr = (void *)skb->data;
		info = IEEE80211_SKB_CB(skb);
813

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814 815 816
		if (skb->next) {
			hdr->frame_control |= morefrags;
			next_len = skb->next->len;
817 818 819 820 821 822 823 824 825 826
			/*
			 * No multi-rate retries for fragmented frames, that
			 * would completely throw off the NAV at other STAs.
			 */
			info->control.rates[1].idx = -1;
			info->control.rates[2].idx = -1;
			info->control.rates[3].idx = -1;
			info->control.rates[4].idx = -1;
			BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
			info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
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827 828 829
		} else {
			hdr->frame_control &= ~morefrags;
			next_len = 0;
830
		}
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831 832 833 834
		hdr->duration_id = ieee80211_duration(tx, 0, next_len);
		hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
		fragnum++;
	} while ((skb = skb->next));
835

836
	return TX_CONTINUE;
837 838
}

839
static ieee80211_tx_result debug_noinline
840 841 842 843 844 845 846 847 848 849 850 851
ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
{
	if (!tx->key)
		return TX_CONTINUE;

	switch (tx->key->conf.alg) {
	case ALG_WEP:
		return ieee80211_crypto_wep_encrypt(tx);
	case ALG_TKIP:
		return ieee80211_crypto_tkip_encrypt(tx);
	case ALG_CCMP:
		return ieee80211_crypto_ccmp_encrypt(tx);
852 853
	case ALG_AES_CMAC:
		return ieee80211_crypto_aes_cmac_encrypt(tx);
854 855 856 857 858 859 860
	}

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

861
static ieee80211_tx_result debug_noinline
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862 863
ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
{
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	struct sk_buff *skb = tx->skb;
	struct ieee80211_hdr *hdr;
	int next_len;
	bool group_addr;
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869 870 871 872
	do {
		hdr = (void *) skb->data;
		next_len = skb->next ? skb->next->len : 0;
		group_addr = is_multicast_ether_addr(hdr->addr1);
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		hdr->duration_id =
			ieee80211_duration(tx, group_addr, next_len);
	} while ((skb = skb->next));
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	return TX_CONTINUE;
}

881
static ieee80211_tx_result debug_noinline
882
ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
883
{
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	struct sk_buff *skb = tx->skb;
885

886 887
	if (!tx->sta)
		return TX_CONTINUE;
888

889
	tx->sta->tx_packets++;
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890 891 892 893
	do {
		tx->sta->tx_fragments++;
		tx->sta->tx_bytes += skb->len;
	} while ((skb = skb->next));
894

895
	return TX_CONTINUE;
896 897 898 899 900 901 902 903
}

/* actual transmit path */

/*
 * deal with packet injection down monitor interface
 * with Radiotap Header -- only called for monitor mode interface
 */
904
static ieee80211_tx_result
905
__ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
906
			      struct sk_buff *skb)
907 908 909 910 911 912 913 914 915 916 917 918
{
	/*
	 * 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;
919
	struct ieee80211_supported_band *sband;
920 921
	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len);

922
	sband = tx->local->hw.wiphy->bands[tx->channel->band];
923

924
	skb->do_not_encrypt = 1;
925
	tx->flags &= ~IEEE80211_TX_FRAGMENTED;
926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956

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

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

		if (ret)
			continue;

		/* see if this argument is something we can use */
		switch (iterator.this_arg_index) {
		/*
		 * You must take care when dereferencing iterator.this_arg
		 * for multibyte types... the pointer is not aligned.  Use
		 * get_unaligned((type *)iterator.this_arg) to dereference
		 * iterator.this_arg for type "type" safely on all arches.
		*/
		case IEEE80211_RADIOTAP_FLAGS:
			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
				/*
				 * this indicates that the skb we have been
				 * handed has the 32-bit FCS CRC at the end...
				 * we should react to that by snipping it off
				 * because it will be recomputed and added
				 * on transmission
				 */
				if (skb->len < (iterator.max_length + FCS_LEN))
957
					return TX_DROP;
958 959 960

				skb_trim(skb, skb->len - FCS_LEN);
			}
961
			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
962
				tx->skb->do_not_encrypt = 0;
963
			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
964
				tx->flags |= IEEE80211_TX_FRAGMENTED;
965 966
			break;

967 968 969 970 971 972
		/*
		 * Please update the file
		 * Documentation/networking/mac80211-injection.txt
		 * when parsing new fields here.
		 */

973 974 975 976 977 978
		default:
			break;
		}
	}

	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
979
		return TX_DROP;
980 981 982 983 984 985 986 987

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

988
	return TX_CONTINUE;
989 990
}

991 992 993
/*
 * initialises @tx
 */
994
static ieee80211_tx_result
995
__ieee80211_tx_prepare(struct ieee80211_tx_data *tx,
996
		       struct sk_buff *skb,
997
		       struct net_device *dev)
998 999
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1000
	struct ieee80211_hdr *hdr;
1001
	struct ieee80211_sub_if_data *sdata;
1002
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
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	int hdrlen, tid;
	u8 *qc, *state;
1005
	bool queued = false;
1006 1007 1008 1009 1010 1011

	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);
1012
	tx->channel = local->hw.conf.channel;
1013
	/*
1014 1015
	 * Set this flag (used below to indicate "automatic fragmentation"),
	 * it will be cleared/left by radiotap as desired.
1016
	 */
1017
	tx->flags |= IEEE80211_TX_FRAGMENTED;
1018 1019 1020

	/* process and remove the injection radiotap header */
	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1021
	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED)) {
1022 1023
		if (__ieee80211_parse_tx_radiotap(tx, skb) == TX_DROP)
			return TX_DROP;
1024

1025
		/*
1026 1027 1028
		 * __ieee80211_parse_tx_radiotap has now removed
		 * the radiotap header that was present and pre-filled
		 * 'tx' with tx control information.
1029 1030 1031
		 */
	}

1032 1033 1034 1035 1036 1037 1038
	/*
	 * If this flag is set to true anywhere, and we get here,
	 * we are doing the needed processing, so remove the flag
	 * now.
	 */
	info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;

1039 1040
	hdr = (struct ieee80211_hdr *) skb->data;

1041
	tx->sta = sta_info_get(local, hdr->addr1);
1042

1043 1044
	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)) {
1045
		unsigned long flags;
1046 1047
		struct tid_ampdu_tx *tid_tx;

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1048 1049 1050
		qc = ieee80211_get_qos_ctl(hdr);
		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;

1051
		spin_lock_irqsave(&tx->sta->lock, flags);
1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065
		/*
		 * XXX: This spinlock could be fairly expensive, but see the
		 *	comment in agg-tx.c:ieee80211_agg_tx_operational().
		 *	One way to solve this would be to do something RCU-like
		 *	for managing the tid_tx struct and using atomic bitops
		 *	for the actual state -- by introducing an actual
		 *	'operational' bit that would be possible. It would
		 *	require changing ieee80211_agg_tx_operational() to
		 *	set that bit, and changing the way tid_tx is managed
		 *	everywhere, including races between that bit and
		 *	tid_tx going away (tid_tx being added can be easily
		 *	committed to memory before the 'operational' bit).
		 */
		tid_tx = tx->sta->ampdu_mlme.tid_tx[tid];
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		state = &tx->sta->ampdu_mlme.tid_state_tx[tid];
1067
		if (*state == HT_AGG_STATE_OPERATIONAL) {
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1068
			info->flags |= IEEE80211_TX_CTL_AMPDU;
1069 1070 1071 1072 1073 1074
		} else if (*state != HT_AGG_STATE_IDLE) {
			/* in progress */
			queued = true;
			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
			__skb_queue_tail(&tid_tx->pending, skb);
		}
1075
		spin_unlock_irqrestore(&tx->sta->lock, flags);
1076 1077 1078

		if (unlikely(queued))
			return TX_QUEUED;
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1079 1080
	}

1081
	if (is_multicast_ether_addr(hdr->addr1)) {
1082
		tx->flags &= ~IEEE80211_TX_UNICAST;
1083
		info->flags |= IEEE80211_TX_CTL_NO_ACK;
1084
	} else {
1085
		tx->flags |= IEEE80211_TX_UNICAST;
1086
		info->flags &= ~IEEE80211_TX_CTL_NO_ACK;
1087
	}
1088

1089 1090
	if (tx->flags & IEEE80211_TX_FRAGMENTED) {
		if ((tx->flags & IEEE80211_TX_UNICAST) &&
1091
		    skb->len + FCS_LEN > local->hw.wiphy->frag_threshold &&
1092
		    !(info->flags & IEEE80211_TX_CTL_AMPDU))
1093
			tx->flags |= IEEE80211_TX_FRAGMENTED;
1094
		else
1095
			tx->flags &= ~IEEE80211_TX_FRAGMENTED;
1096 1097
	}

1098
	if (!tx->sta)
1099
		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1100
	else if (test_and_clear_sta_flags(tx->sta, WLAN_STA_CLEAR_PS_FILT))
1101
		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1102

1103
	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1104 1105 1106 1107
	if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
		u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
		tx->ethertype = (pos[0] << 8) | pos[1];
	}
1108
	info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1109

1110
	return TX_CONTINUE;
1111 1112
}

1113
/*
1114 1115
 * NB: @tx is uninitialised when passed in here
 */
1116 1117 1118
static int ieee80211_tx_prepare(struct ieee80211_local *local,
				struct ieee80211_tx_data *tx,
				struct sk_buff *skb)
1119 1120 1121
{
	struct net_device *dev;

1122
	dev = dev_get_by_index(&init_net, skb->iif);
1123
	if (unlikely(dev && !is_ieee80211_device(local, dev))) {
1124 1125 1126 1127 1128
		dev_put(dev);
		dev = NULL;
	}
	if (unlikely(!dev))
		return -ENODEV;
1129 1130 1131 1132 1133 1134 1135 1136
	/*
	 * initialises tx with control
	 *
	 * return value is safe to ignore here because this function
	 * can only be invoked for multicast frames
	 *
	 * XXX: clean up
	 */
1137
	__ieee80211_tx_prepare(tx, skb, dev);
1138
	dev_put(dev);
1139 1140 1141
	return 0;
}

J
Johannes Berg 已提交
1142
static int __ieee80211_tx(struct ieee80211_local *local,
1143 1144
			  struct sk_buff **skbp,
			  struct sta_info *sta)
1145
{
1146
	struct sk_buff *skb = *skbp, *next;
1147
	struct ieee80211_tx_info *info;
1148
	int ret, len;
J
Johannes Berg 已提交
1149
	bool fragm = false;
1150

J
Johannes Berg 已提交
1151 1152 1153
	local->mdev->trans_start = jiffies;

	while (skb) {
1154 1155
		if (ieee80211_queue_stopped(&local->hw,
					    skb_get_queue_mapping(skb)))
1156
			return IEEE80211_TX_PENDING;
1157

1158 1159 1160
		info = IEEE80211_SKB_CB(skb);

		if (fragm)
1161
			info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
1162
					 IEEE80211_TX_CTL_FIRST_FRAGMENT);
1163

J
Johannes Berg 已提交
1164
		next = skb->next;
1165
		len = skb->len;
1166
		ret = drv_tx(local, skb);
1167 1168 1169 1170
		if (WARN_ON(ret != NETDEV_TX_OK && skb->len != len)) {
			dev_kfree_skb(skb);
			ret = NETDEV_TX_OK;
		}
J
Johannes Berg 已提交
1171 1172
		if (ret != NETDEV_TX_OK)
			return IEEE80211_TX_AGAIN;
1173
		*skbp = skb = next;
J
Johannes Berg 已提交
1174 1175
		ieee80211_led_tx(local, 1);
		fragm = true;
1176
	}
J
Johannes Berg 已提交
1177

1178 1179 1180
	return IEEE80211_TX_OK;
}

1181 1182 1183 1184 1185 1186 1187 1188 1189
/*
 * Invoke TX handlers, return 0 on success and non-zero if the
 * frame was dropped or queued.
 */
static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
{
	struct sk_buff *skb = tx->skb;
	ieee80211_tx_result res = TX_DROP;

1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200
#define CALL_TXH(txh)		\
	res = txh(tx);		\
	if (res != TX_CONTINUE)	\
		goto txh_done;

	CALL_TXH(ieee80211_tx_h_check_assoc)
	CALL_TXH(ieee80211_tx_h_ps_buf)
	CALL_TXH(ieee80211_tx_h_select_key)
	CALL_TXH(ieee80211_tx_h_michael_mic_add)
	CALL_TXH(ieee80211_tx_h_rate_ctrl)
	CALL_TXH(ieee80211_tx_h_misc)
1201
	CALL_TXH(ieee80211_tx_h_sequence)
1202 1203 1204 1205 1206 1207
	CALL_TXH(ieee80211_tx_h_fragment)
	/* handlers after fragment must be aware of tx info fragmentation! */
	CALL_TXH(ieee80211_tx_h_encrypt)
	CALL_TXH(ieee80211_tx_h_calculate_duration)
	CALL_TXH(ieee80211_tx_h_stats)
#undef CALL_TXH
1208

1209
 txh_done:
1210
	if (unlikely(res == TX_DROP)) {
1211
		I802_DEBUG_INC(tx->local->tx_handlers_drop);
J
Johannes Berg 已提交
1212 1213 1214 1215 1216 1217 1218
		while (skb) {
			struct sk_buff *next;

			next = skb->next;
			dev_kfree_skb(skb);
			skb = next;
		}
1219 1220
		return -1;
	} else if (unlikely(res == TX_QUEUED)) {
1221
		I802_DEBUG_INC(tx->local->tx_handlers_queued);
1222 1223 1224 1225 1226 1227
		return -1;
	}

	return 0;
}

1228 1229
static void ieee80211_tx(struct net_device *dev, struct sk_buff *skb,
			 bool txpending)
1230 1231 1232
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct sta_info *sta;
1233
	struct ieee80211_tx_data tx;
1234
	ieee80211_tx_result res_prepare;
1235
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1236 1237 1238
	struct sk_buff *next;
	unsigned long flags;
	int ret, retries;
1239
	u16 queue;
1240

1241 1242
	queue = skb_get_queue_mapping(skb);

1243
	WARN_ON(!txpending && !skb_queue_empty(&local->pending[queue]));
1244 1245 1246

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

1250 1251
	rcu_read_lock();

1252
	/* initialises tx */
1253
	res_prepare = __ieee80211_tx_prepare(&tx, skb, dev);
1254

1255
	if (unlikely(res_prepare == TX_DROP)) {
1256
		dev_kfree_skb(skb);
1257
		rcu_read_unlock();
1258 1259 1260 1261
		return;
	} else if (unlikely(res_prepare == TX_QUEUED)) {
		rcu_read_unlock();
		return;
1262 1263 1264
	}

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

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

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

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

1291 1292 1293 1294
		if (__netif_subqueue_stopped(local->mdev, queue)) {
			do {
				next = skb->next;
				skb->next = NULL;
1295 1296 1297 1298 1299 1300
				if (unlikely(txpending))
					skb_queue_head(&local->pending[queue],
						       skb);
				else
					skb_queue_tail(&local->pending[queue],
						       skb);
1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319
			} while ((skb = next));

			/*
			 * Make sure nobody will enable the queue on us
			 * (without going through the tasklet) nor disable the
			 * netdev queue underneath the pending handling code.
			 */
			__set_bit(IEEE80211_QUEUE_STOP_REASON_PENDING,
				  &local->queue_stop_reasons[queue]);

			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
					       flags);
		} else {
			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
					       flags);

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

 drop:
1328
	rcu_read_unlock();
J
Johannes Berg 已提交
1329 1330 1331 1332 1333 1334 1335

	skb = tx.skb;
	while (skb) {
		next = skb->next;
		dev_kfree_skb(skb);
		skb = next;
	}
1336 1337 1338 1339
}

/* device xmit handlers */

1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378
static int ieee80211_skb_resize(struct ieee80211_local *local,
				struct sk_buff *skb,
				int head_need, bool may_encrypt)
{
	int tail_need = 0;

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

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

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

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

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

	return 0;
}

1379
int ieee80211_master_start_xmit(struct sk_buff *skb, struct net_device *dev)
1380
{
1381 1382
	struct ieee80211_master_priv *mpriv = netdev_priv(dev);
	struct ieee80211_local *local = mpriv->local;
1383
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1384
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1385 1386 1387
	struct net_device *odev = NULL;
	struct ieee80211_sub_if_data *osdata;
	int headroom;
1388
	bool may_encrypt;
1389 1390 1391 1392 1393
	enum {
		NOT_MONITOR,
		FOUND_SDATA,
		UNKNOWN_ADDRESS,
	} monitor_iface = NOT_MONITOR;
1394

1395 1396
	if (skb->iif)
		odev = dev_get_by_index(&init_net, skb->iif);
1397
	if (unlikely(odev && !is_ieee80211_device(local, odev))) {
1398 1399 1400 1401 1402 1403 1404 1405 1406
		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);
1407
		return NETDEV_TX_OK;
1408
	}
1409

1410
	if ((local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) &&
1411
	    local->hw.conf.dynamic_ps_timeout > 0) {
1412 1413 1414 1415 1416 1417 1418 1419
		if (local->hw.conf.flags & IEEE80211_CONF_PS) {
			ieee80211_stop_queues_by_reason(&local->hw,
					IEEE80211_QUEUE_STOP_REASON_PS);
			queue_work(local->hw.workqueue,
					&local->dynamic_ps_disable_work);
		}

		mod_timer(&local->dynamic_ps_timer, jiffies +
1420
		        msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
1421 1422
	}

1423 1424 1425 1426
	memset(info, 0, sizeof(*info));

	info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;

1427 1428
	osdata = IEEE80211_DEV_TO_SUB_IF(odev);

1429 1430
	if (ieee80211_vif_is_mesh(&osdata->vif) &&
	    ieee80211_is_data(hdr->frame_control)) {
1431 1432 1433
		if (is_multicast_ether_addr(hdr->addr3))
			memcpy(hdr->addr1, hdr->addr3, ETH_ALEN);
		else
1434 1435
			if (mesh_nexthop_lookup(skb, osdata)) {
				dev_put(odev);
1436
				return NETDEV_TX_OK;
1437
			}
1438 1439 1440
		if (memcmp(odev->dev_addr, hdr->addr4, ETH_ALEN) != 0)
			IEEE80211_IFSTA_MESH_CTR_INC(&osdata->u.mesh,
							    fwded_frames);
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
	} else if (unlikely(osdata->vif.type == NL80211_IFTYPE_MONITOR)) {
		struct ieee80211_sub_if_data *sdata;
		int hdrlen;
		u16 len_rthdr;

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

		len_rthdr = ieee80211_get_radiotap_len(skb->data);
		hdr = (struct ieee80211_hdr *)skb->data + len_rthdr;
		hdrlen = ieee80211_hdrlen(hdr->frame_control);

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

			rcu_read_lock();
			list_for_each_entry_rcu(sdata, &local->interfaces,
						list) {
				if (!netif_running(sdata->dev))
					continue;
1470 1471
				if (sdata->vif.type != NL80211_IFTYPE_AP)
					continue;
1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484
				if (compare_ether_addr(sdata->dev->dev_addr,
						       hdr->addr2)) {
					dev_hold(sdata->dev);
					dev_put(odev);
					osdata = sdata;
					odev = osdata->dev;
					skb->iif = sdata->dev->ifindex;
					monitor_iface = FOUND_SDATA;
					break;
				}
			}
			rcu_read_unlock();
		}
1485 1486
	}

1487
	may_encrypt = !skb->do_not_encrypt;
1488 1489 1490 1491 1492 1493 1494 1495 1496 1497

	headroom = osdata->local->tx_headroom;
	if (may_encrypt)
		headroom += IEEE80211_ENCRYPT_HEADROOM;
	headroom -= skb_headroom(skb);
	headroom = max_t(int, 0, headroom);

	if (ieee80211_skb_resize(osdata->local, skb, headroom, may_encrypt)) {
		dev_kfree_skb(skb);
		dev_put(odev);
1498
		return NETDEV_TX_OK;
1499 1500
	}

1501 1502 1503 1504
	if (osdata->vif.type == NL80211_IFTYPE_AP_VLAN)
		osdata = container_of(osdata->bss,
				      struct ieee80211_sub_if_data,
				      u.ap);
1505 1506
	if (likely(monitor_iface != UNKNOWN_ADDRESS))
		info->control.vif = &osdata->vif;
1507 1508

	ieee80211_tx(odev, skb, false);
1509 1510
	dev_put(odev);

1511
	return NETDEV_TX_OK;
1512 1513 1514 1515 1516 1517
}

int ieee80211_monitor_start_xmit(struct sk_buff *skb,
				 struct net_device *dev)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1518
	struct ieee80211_channel *chan = local->hw.conf.channel;
1519 1520
	struct ieee80211_radiotap_header *prthdr =
		(struct ieee80211_radiotap_header *)skb->data;
1521
	u16 len_rthdr;
1522

1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542
	/*
	 * Frame injection is not allowed if beaconing is not allowed
	 * or if we need radar detection. Beaconing is usually not allowed when
	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
	 * Passive scan is also used in world regulatory domains where
	 * your country is not known and as such it should be treated as
	 * NO TX unless the channel is explicitly allowed in which case
	 * your current regulatory domain would not have the passive scan
	 * flag.
	 *
	 * Since AP mode uses monitor interfaces to inject/TX management
	 * frames we can make AP mode the exception to this rule once it
	 * supports radar detection as its implementation can deal with
	 * radar detection by itself. We can do that later by adding a
	 * monitor flag interfaces used for AP support.
	 */
	if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR |
	     IEEE80211_CHAN_PASSIVE_SCAN)))
		goto fail;

1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556
	/* 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 */
1557 1558 1559

	skb->dev = local->mdev;

1560
	/* needed because we set skb device to master */
1561
	skb->iif = dev->ifindex;
1562

1563 1564 1565
	/* sometimes we do encrypt injected frames, will be fixed
	 * up in radiotap parser if not wanted */
	skb->do_not_encrypt = 0;
1566 1567 1568 1569 1570 1571 1572

	/*
	 * 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
	 */
1573
	skb_set_mac_header(skb, len_rthdr);
1574
	/*
1575 1576
	 * 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
1577
	 */
1578 1579
	skb_set_network_header(skb, len_rthdr);
	skb_set_transport_header(skb, len_rthdr);
1580

1581 1582
	/* pass the radiotap header up to the next stage intact */
	dev_queue_xmit(skb);
1583
	return NETDEV_TX_OK;
1584 1585 1586 1587

fail:
	dev_kfree_skb(skb);
	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607
}

/**
 * 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)
{
1608 1609
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	struct ieee80211_local *local = sdata->local;
1610
	int ret = 1, head_need;
1611 1612
	u16 ethertype, hdrlen,  meshhdrlen = 0;
	__le16 fc;
1613
	struct ieee80211_hdr hdr;
1614
	struct ieee80211s_hdr mesh_hdr;
1615 1616
	const u8 *encaps_data;
	int encaps_len, skip_header_bytes;
1617
	int nh_pos, h_pos;
1618
	struct sta_info *sta;
1619
	u32 sta_flags = 0;
1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631

	if (unlikely(skb->len < ETH_HLEN)) {
		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];
1632
	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
1633

1634
	switch (sdata->vif.type) {
1635 1636
	case NL80211_IFTYPE_AP:
	case NL80211_IFTYPE_AP_VLAN:
1637
		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1638 1639 1640 1641 1642
		/* 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;
1643
		break;
1644
	case NL80211_IFTYPE_WDS:
1645
		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1646 1647 1648 1649 1650 1651
		/* 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;
1652
		break;
1653
#ifdef CONFIG_MAC80211_MESH
1654
	case NL80211_IFTYPE_MESH_POINT:
1655
		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1656
		if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
1657
			/* Do not send frames with mesh_ttl == 0 */
1658
			sdata->u.mesh.mshstats.dropped_frames_ttl++;
1659 1660
			ret = 0;
			goto fail;
1661
		}
1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699
		memset(&mesh_hdr, 0, sizeof(mesh_hdr));

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

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

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

			mesh_hdr.flags |= MESH_FLAGS_AE_A5_A6;
			mesh_hdr.ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
			put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &mesh_hdr.seqnum);
			memcpy(mesh_hdr.eaddr1, skb->data, ETH_ALEN);
			memcpy(mesh_hdr.eaddr2, skb->data + ETH_ALEN, ETH_ALEN);
			sdata->u.mesh.mesh_seqnum++;
			meshhdrlen = 18;
		}
1700 1701 1702
		hdrlen = 30;
		break;
#endif
1703
	case NL80211_IFTYPE_STATION:
1704
		fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1705
		/* BSSID SA DA */
1706
		memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1707 1708 1709
		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
		memcpy(hdr.addr3, skb->data, ETH_ALEN);
		hdrlen = 24;
1710
		break;
1711
	case NL80211_IFTYPE_ADHOC:
1712 1713 1714
		/* DA SA BSSID */
		memcpy(hdr.addr1, skb->data, ETH_ALEN);
		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1715
		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
1716
		hdrlen = 24;
1717 1718
		break;
	default:
1719 1720 1721 1722
		ret = 0;
		goto fail;
	}

1723 1724 1725 1726 1727 1728
	/*
	 * There's no need to try to look up the destination
	 * if it is a multicast address (which can only happen
	 * in AP mode)
	 */
	if (!is_multicast_ether_addr(hdr.addr1)) {
1729
		rcu_read_lock();
1730
		sta = sta_info_get(local, hdr.addr1);
1731
		if (sta)
1732
			sta_flags = get_sta_flags(sta);
1733
		rcu_read_unlock();
1734 1735
	}

1736
	/* receiver and we are QoS enabled, use a QoS type frame */
1737
	if ((sta_flags & WLAN_STA_WME) && local->hw.queues >= 4) {
1738
		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1739 1740 1741 1742
		hdrlen += 2;
	}

	/*
1743 1744
	 * Drop unicast frames to unauthorised stations unless they are
	 * EAPOL frames from the local station.
1745
	 */
1746 1747
	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
		unlikely(!is_multicast_ether_addr(hdr.addr1) &&
1748 1749
		      !(sta_flags & WLAN_STA_AUTHORIZED) &&
		      !(ethertype == ETH_P_PAE &&
1750 1751 1752 1753
		       compare_ether_addr(dev->dev_addr,
					  skb->data + ETH_ALEN) == 0))) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
		if (net_ratelimit())
1754
			printk(KERN_DEBUG "%s: dropped frame to %pM"
1755
			       " (unauthorized port)\n", dev->name,
1756
			       hdr.addr1);
1757 1758 1759 1760 1761 1762 1763 1764
#endif

		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);

		ret = 0;
		goto fail;
	}

1765
	hdr.frame_control = fc;
1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786
	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;

1787
	head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
1788

1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799
	/*
	 * So we need to modify the skb header and hence need a copy of
	 * that. The head_need variable above doesn't, so far, include
	 * the needed header space that we don't need right away. If we
	 * can, then we don't reallocate right now but only after the
	 * frame arrives at the master device (if it does...)
	 *
	 * If we cannot, however, then we will reallocate to include all
	 * the ever needed space. Also, if we need to reallocate it anyway,
	 * make it big enough for everything we may ever need.
	 */
1800

1801
	if (head_need > 0 || skb_cloned(skb)) {
1802 1803 1804 1805
		head_need += IEEE80211_ENCRYPT_HEADROOM;
		head_need += local->tx_headroom;
		head_need = max_t(int, 0, head_need);
		if (ieee80211_skb_resize(local, skb, head_need, true))
1806 1807 1808 1809 1810 1811 1812 1813
			goto fail;
	}

	if (encaps_data) {
		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
		nh_pos += encaps_len;
		h_pos += encaps_len;
	}
1814

1815 1816 1817 1818 1819 1820
	if (meshhdrlen > 0) {
		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
		nh_pos += meshhdrlen;
		h_pos += meshhdrlen;
	}

1821
	if (ieee80211_is_data_qos(fc)) {
1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833
		__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);

1834 1835 1836
	nh_pos += hdrlen;
	h_pos += hdrlen;

1837
	skb->iif = dev->ifindex;
1838

1839
	skb->dev = local->mdev;
1840 1841
	dev->stats.tx_packets++;
	dev->stats.tx_bytes += skb->len;
1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862

	/* 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;
}


1863 1864 1865 1866
/*
 * ieee80211_clear_tx_pending may not be called in a context where
 * it is possible that it packets could come in again.
 */
1867 1868
void ieee80211_clear_tx_pending(struct ieee80211_local *local)
{
J
Johannes Berg 已提交
1869
	int i;
1870

1871 1872
	for (i = 0; i < local->hw.queues; i++)
		skb_queue_purge(&local->pending[i]);
1873 1874
}

1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922
static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
				     struct sk_buff *skb)
{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ieee80211_sub_if_data *sdata;
	struct sta_info *sta;
	struct ieee80211_hdr *hdr;
	struct net_device *dev;
	int ret;
	bool result = true;

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

	/* validate info->control.vif against skb->iif */
	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
		sdata = container_of(sdata->bss,
				     struct ieee80211_sub_if_data,
				     u.ap);

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

	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
		ieee80211_tx(dev, skb, true);
	} else {
		hdr = (struct ieee80211_hdr *)skb->data;
		sta = sta_info_get(local, hdr->addr1);

		ret = __ieee80211_tx(local, &skb, sta);
		if (ret != IEEE80211_TX_OK)
			result = false;
	}

 out:
	dev_put(dev);

	return result;
}

1923 1924 1925 1926
/*
 * Transmit all pending packets. Called from tasklet, locks master device
 * TX lock so that no new packets can come in.
 */
1927 1928 1929 1930
void ieee80211_tx_pending(unsigned long data)
{
	struct ieee80211_local *local = (struct ieee80211_local *)data;
	struct net_device *dev = local->mdev;
1931
	unsigned long flags;
1932
	int i;
1933
	bool next;
1934

1935
	rcu_read_lock();
1936
	netif_tx_lock_bh(dev);
1937

1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951
	for (i = 0; i < local->hw.queues; i++) {
		/*
		 * If queue is stopped by something other than due to pending
		 * frames, or we have no pending frames, proceed to next queue.
		 */
		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
		next = false;
		if (local->queue_stop_reasons[i] !=
			BIT(IEEE80211_QUEUE_STOP_REASON_PENDING) ||
		    skb_queue_empty(&local->pending[i]))
			next = true;
		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);

		if (next)
1952
			continue;
1953

1954 1955 1956 1957 1958
		/*
		 * start the queue now to allow processing our packets,
		 * we're under the tx lock here anyway so nothing will
		 * happen as a result of this
		 */
1959 1960
		netif_start_subqueue(local->mdev, i);

1961
		while (!skb_queue_empty(&local->pending[i])) {
1962
			struct sk_buff *skb = skb_dequeue(&local->pending[i]);
1963

1964
			if (!ieee80211_tx_pending_skb(local, skb)) {
1965
				skb_queue_head(&local->pending[i], skb);
1966 1967
				break;
			}
1968
		}
1969 1970 1971 1972 1973

		/* Start regular packet processing again. */
		if (skb_queue_empty(&local->pending[i]))
			ieee80211_wake_queue_by_reason(&local->hw, i,
					IEEE80211_QUEUE_STOP_REASON_PENDING);
1974
	}
1975

1976
	netif_tx_unlock_bh(dev);
1977
	rcu_read_unlock();
1978 1979 1980 1981
}

/* functions for drivers to get certain frames */

R
Rami Rosen 已提交
1982
static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss,
1983 1984
				     struct sk_buff *skb,
				     struct beacon_data *beacon)
1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998
{
	u8 *pos, *tim;
	int aid0 = 0;
	int i, have_bits = 0, n1, n2;

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

	if (bss->dtim_count == 0)
1999
		bss->dtim_count = beacon->dtim_period - 1;
2000 2001 2002 2003 2004 2005 2006
	else
		bss->dtim_count--;

	tim = pos = (u8 *) skb_put(skb, 6);
	*pos++ = WLAN_EID_TIM;
	*pos++ = 4;
	*pos++ = bss->dtim_count;
2007
	*pos++ = beacon->dtim_period;
2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043

	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 */
	}
}

2044
struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
2045
				     struct ieee80211_vif *vif)
2046 2047
{
	struct ieee80211_local *local = hw_to_local(hw);
2048
	struct sk_buff *skb = NULL;
2049
	struct ieee80211_tx_info *info;
2050 2051
	struct ieee80211_sub_if_data *sdata = NULL;
	struct ieee80211_if_ap *ap = NULL;
2052
	struct beacon_data *beacon;
2053
	struct ieee80211_supported_band *sband;
2054
	enum ieee80211_band band = local->hw.conf.channel->band;
2055

2056
	sband = local->hw.wiphy->bands[band];
2057 2058

	rcu_read_lock();
2059

2060
	sdata = vif_to_sdata(vif);
2061

2062
	if (sdata->vif.type == NL80211_IFTYPE_AP) {
2063 2064
		ap = &sdata->u.ap;
		beacon = rcu_dereference(ap->beacon);
J
Johannes Berg 已提交
2065 2066 2067 2068 2069 2070 2071 2072 2073 2074
		if (ap && beacon) {
			/*
			 * headroom, head length,
			 * tail length and maximum TIM length
			 */
			skb = dev_alloc_skb(local->tx_headroom +
					    beacon->head_len +
					    beacon->tail_len + 256);
			if (!skb)
				goto out;
2075

J
Johannes Berg 已提交
2076 2077 2078
			skb_reserve(skb, local->tx_headroom);
			memcpy(skb_put(skb, beacon->head_len), beacon->head,
			       beacon->head_len);
2079

2080 2081 2082 2083 2084 2085 2086 2087
			/*
			 * Not very nice, but we want to allow the driver to call
			 * ieee80211_beacon_get() as a response to the set_tim()
			 * callback. That, however, is already invoked under the
			 * sta_lock to guarantee consistent and race-free update
			 * of the tim bitmap in mac80211 and the driver.
			 */
			if (local->tim_in_locked_section) {
R
Rami Rosen 已提交
2088
				ieee80211_beacon_add_tim(ap, skb, beacon);
2089 2090 2091 2092
			} else {
				unsigned long flags;

				spin_lock_irqsave(&local->sta_lock, flags);
R
Rami Rosen 已提交
2093
				ieee80211_beacon_add_tim(ap, skb, beacon);
2094 2095
				spin_unlock_irqrestore(&local->sta_lock, flags);
			}
2096

J
Johannes Berg 已提交
2097 2098 2099
			if (beacon->tail)
				memcpy(skb_put(skb, beacon->tail_len),
				       beacon->tail, beacon->tail_len);
2100 2101
		} else
			goto out;
2102
	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
2103
		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2104
		struct ieee80211_hdr *hdr;
2105
		struct sk_buff *presp = rcu_dereference(ifibss->presp);
2106

2107
		if (!presp)
2108 2109
			goto out;

2110
		skb = skb_copy(presp, GFP_ATOMIC);
2111 2112 2113 2114
		if (!skb)
			goto out;

		hdr = (struct ieee80211_hdr *) skb->data;
2115 2116
		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
						 IEEE80211_STYPE_BEACON);
J
Johannes Berg 已提交
2117
	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2118 2119 2120
		struct ieee80211_mgmt *mgmt;
		u8 *pos;

J
Johannes Berg 已提交
2121 2122 2123 2124 2125 2126 2127 2128 2129
		/* headroom, head length, tail length and maximum TIM length */
		skb = dev_alloc_skb(local->tx_headroom + 400);
		if (!skb)
			goto out;

		skb_reserve(skb, local->hw.extra_tx_headroom);
		mgmt = (struct ieee80211_mgmt *)
			skb_put(skb, 24 + sizeof(mgmt->u.beacon));
		memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
2130 2131
		mgmt->frame_control =
		    cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
J
Johannes Berg 已提交
2132 2133 2134 2135
		memset(mgmt->da, 0xff, ETH_ALEN);
		memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
		/* BSSID is left zeroed, wildcard value */
		mgmt->u.beacon.beacon_int =
2136
			cpu_to_le16(sdata->vif.bss_conf.beacon_int);
J
Johannes Berg 已提交
2137 2138 2139 2140 2141 2142
		mgmt->u.beacon.capab_info = 0x0; /* 0x0 for MPs */

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

2143
		mesh_mgmt_ies_add(skb, sdata);
2144 2145
	} else {
		WARN_ON(1);
2146
		goto out;
2147 2148
	}

2149 2150
	info = IEEE80211_SKB_CB(skb);

2151 2152
	skb->do_not_encrypt = 1;

2153
	info->band = band;
2154 2155 2156 2157 2158 2159 2160 2161 2162 2163
	/*
	 * XXX: For now, always use the lowest rate
	 */
	info->control.rates[0].idx = 0;
	info->control.rates[0].count = 1;
	info->control.rates[1].idx = -1;
	info->control.rates[2].idx = -1;
	info->control.rates[3].idx = -1;
	info->control.rates[4].idx = -1;
	BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
2164 2165

	info->control.vif = vif;
2166 2167 2168 2169

	info->flags |= IEEE80211_TX_CTL_NO_ACK;
	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
	info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
2170
 out:
2171
	rcu_read_unlock();
2172 2173 2174 2175
	return skb;
}
EXPORT_SYMBOL(ieee80211_beacon_get);

2176
void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2177
		       const void *frame, size_t frame_len,
2178
		       const struct ieee80211_tx_info *frame_txctl,
2179 2180 2181 2182
		       struct ieee80211_rts *rts)
{
	const struct ieee80211_hdr *hdr = frame;

2183 2184
	rts->frame_control =
	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2185 2186
	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
					       frame_txctl);
2187 2188 2189 2190 2191
	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
}
EXPORT_SYMBOL(ieee80211_rts_get);

2192
void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2193
			     const void *frame, size_t frame_len,
2194
			     const struct ieee80211_tx_info *frame_txctl,
2195 2196 2197 2198
			     struct ieee80211_cts *cts)
{
	const struct ieee80211_hdr *hdr = frame;

2199 2200
	cts->frame_control =
	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2201 2202
	cts->duration = ieee80211_ctstoself_duration(hw, vif,
						     frame_len, frame_txctl);
2203 2204 2205 2206 2207
	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
}
EXPORT_SYMBOL(ieee80211_ctstoself_get);

struct sk_buff *
2208
ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2209
			  struct ieee80211_vif *vif)
2210 2211
{
	struct ieee80211_local *local = hw_to_local(hw);
2212
	struct sk_buff *skb = NULL;
2213
	struct sta_info *sta;
2214
	struct ieee80211_tx_data tx;
2215 2216
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_if_ap *bss = NULL;
2217
	struct beacon_data *beacon;
2218
	struct ieee80211_tx_info *info;
2219

2220
	sdata = vif_to_sdata(vif);
2221
	bss = &sdata->u.ap;
2222 2223

	if (!bss)
2224 2225
		return NULL;

2226 2227 2228
	rcu_read_lock();
	beacon = rcu_dereference(bss->beacon);

2229
	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
2230
		goto out;
2231

2232
	if (bss->dtim_count != 0)
2233
		goto out; /* send buffered bc/mc only after DTIM beacon */
2234

2235 2236 2237
	while (1) {
		skb = skb_dequeue(&bss->ps_bc_buf);
		if (!skb)
2238
			goto out;
2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250
		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);
		}

2251
		if (!ieee80211_tx_prepare(local, &tx, skb))
2252 2253 2254
			break;
		dev_kfree_skb_any(skb);
	}
2255 2256 2257

	info = IEEE80211_SKB_CB(skb);

2258
	sta = tx.sta;
2259 2260
	tx.flags |= IEEE80211_TX_PS_BUFFERED;
	tx.channel = local->hw.conf.channel;
2261
	info->band = tx.channel->band;
2262

2263
	if (invoke_tx_handlers(&tx))
2264
		skb = NULL;
2265
 out:
2266
	rcu_read_unlock();
2267 2268 2269 2270

	return skb;
}
EXPORT_SYMBOL(ieee80211_get_buffered_bc);