tx.c 61.6 KB
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/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 *
 * Transmit and frame generation functions.
 */

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

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

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

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

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

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

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

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

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

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

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	return cpu_to_le16(dur);
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}

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

/* tx handlers */

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

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

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

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	return TX_CONTINUE;
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}

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

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

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

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

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

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

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

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

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

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

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

	return 1;
}

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

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

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		info->control.jiffies = jiffies;
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		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)
436
{
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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 (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
			 (info->flags & IEEE80211_TX_CTL_NO_ACK)))
		info->control.rates[0].count = 1;

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	if (is_multicast_ether_addr(hdr->addr1)) {
		/*
		 * XXX: verify the rate is in the basic rateset
		 */
		return TX_CONTINUE;
570 571
	}

572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596
	/*
	 * 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;
597 598
	}

599 600 601 602 603 604 605 606 607 608 609 610 611 612
	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;
		}
613

614 615 616 617 618 619 620 621
		/*
		 * 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;
		}
622

623 624 625 626
		/* set up RTS protection if desired */
		if (rts)
			info->control.rates[i].flags |=
				IEEE80211_TX_RC_USE_RTS_CTS;
627

628
		/* RC is busted */
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		if (WARN_ON_ONCE(info->control.rates[i].idx >=
				 sband->n_bitrates)) {
631 632
			info->control.rates[i].idx = -1;
			continue;
633
		}
634

635 636 637 638 639 640 641 642 643 644 645 646 647
		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;
648 649
	}

650 651 652 653 654 655 656 657
	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);

658
	if (tx->sta)
659
		info->control.sta = &tx->sta->sta;
660 661 662 663

	return TX_CONTINUE;
}

664 665 666 667 668 669 670 671 672
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;

673 674 675 676 677 678 679 680
	/*
	 * 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;

681 682 683 684 685 686
	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.
	 */
692
	if (!ieee80211_is_data_qos(hdr->frame_control)) {
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		/* driver should assign sequence number */
694
		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
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		/* for pure STA mode without beacons, we can do it */
		hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
		tx->sdata->sequence_number += 0x10;
		tx->sdata->sequence_number &= IEEE80211_SCTL_SEQ;
699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723
		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;
}

771
static ieee80211_tx_result debug_noinline
772 773
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;
777
	int frag_threshold = tx->local->hw.wiphy->frag_threshold;
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	int hdrlen;
	int fragnum;
780 781 782 783

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

784 785
	/*
	 * Warn when submitting a fragmented A-MPDU frame and drop it.
786 787
	 * This scenario is handled in __ieee80211_tx_prepare but extra
	 * caution taken here as fragmented ampdu may cause Tx stop.
788
	 */
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789
	if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
790 791
		return TX_DROP;

792
	hdrlen = ieee80211_hdrlen(hdr->frame_control);
793

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794
	/* internal error, why is TX_FRAGMENTED set? */
795
	if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
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796
		return TX_DROP;
797

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798 799 800 801 802 803 804 805 806 807
	/*
	 * 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;
808

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809 810 811 812 813
	/* update duration/seq/flags of fragments */
	fragnum = 0;
	do {
		int next_len;
		const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
814

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815 816
		hdr = (void *)skb->data;
		info = IEEE80211_SKB_CB(skb);
817

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818 819 820
		if (skb->next) {
			hdr->frame_control |= morefrags;
			next_len = skb->next->len;
821 822 823 824 825 826 827 828 829 830
			/*
			 * 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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831 832 833
		} else {
			hdr->frame_control &= ~morefrags;
			next_len = 0;
834
		}
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835 836 837 838
		hdr->duration_id = ieee80211_duration(tx, 0, next_len);
		hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
		fragnum++;
	} while ((skb = skb->next));
839

840
	return TX_CONTINUE;
841 842
}

843
static ieee80211_tx_result debug_noinline
844 845 846 847 848 849 850 851 852 853 854 855
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);
856 857
	case ALG_AES_CMAC:
		return ieee80211_crypto_aes_cmac_encrypt(tx);
858 859 860 861 862 863 864
	}

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

865
static ieee80211_tx_result debug_noinline
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ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
{
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	struct sk_buff *skb = tx->skb;
	struct ieee80211_hdr *hdr;
	int next_len;
	bool group_addr;
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	do {
		hdr = (void *) skb->data;
		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;
}

885
static ieee80211_tx_result debug_noinline
886
ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
887
{
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	struct sk_buff *skb = tx->skb;
889

890 891
	if (!tx->sta)
		return TX_CONTINUE;
892

893
	tx->sta->tx_packets++;
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	do {
		tx->sta->tx_fragments++;
		tx->sta->tx_bytes += skb->len;
	} while ((skb = skb->next));
898

899
	return TX_CONTINUE;
900 901 902 903 904 905 906 907
}

/* actual transmit path */

/*
 * deal with packet injection down monitor interface
 * with Radiotap Header -- only called for monitor mode interface
 */
908
static ieee80211_tx_result
909
__ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
910
			      struct sk_buff *skb)
911 912 913 914 915 916 917 918 919 920 921 922
{
	/*
	 * 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;
923
	struct ieee80211_supported_band *sband;
924 925
	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len);

926
	sband = tx->local->hw.wiphy->bands[tx->channel->band];
927

928
	skb->do_not_encrypt = 1;
929
	tx->flags &= ~IEEE80211_TX_FRAGMENTED;
930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960

	/*
	 * 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))
961
					return TX_DROP;
962 963 964

				skb_trim(skb, skb->len - FCS_LEN);
			}
965
			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
966
				tx->skb->do_not_encrypt = 0;
967
			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
968
				tx->flags |= IEEE80211_TX_FRAGMENTED;
969 970
			break;

971 972 973 974 975 976
		/*
		 * Please update the file
		 * Documentation/networking/mac80211-injection.txt
		 * when parsing new fields here.
		 */

977 978 979 980 981 982
		default:
			break;
		}
	}

	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
983
		return TX_DROP;
984 985 986 987 988 989 990 991

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

992
	return TX_CONTINUE;
993 994
}

995 996 997
/*
 * initialises @tx
 */
998
static ieee80211_tx_result
999
__ieee80211_tx_prepare(struct ieee80211_tx_data *tx,
1000
		       struct sk_buff *skb,
1001
		       struct net_device *dev)
1002 1003
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1004
	struct ieee80211_hdr *hdr;
1005
	struct ieee80211_sub_if_data *sdata;
1006
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
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	int hdrlen, tid;
	u8 *qc, *state;
1009
	bool queued = false;
1010 1011 1012 1013 1014 1015

	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);
1016
	tx->channel = local->hw.conf.channel;
1017
	/*
1018 1019
	 * Set this flag (used below to indicate "automatic fragmentation"),
	 * it will be cleared/left by radiotap as desired.
1020
	 */
1021
	tx->flags |= IEEE80211_TX_FRAGMENTED;
1022 1023 1024

	/* process and remove the injection radiotap header */
	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1025
	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED)) {
1026 1027
		if (__ieee80211_parse_tx_radiotap(tx, skb) == TX_DROP)
			return TX_DROP;
1028

1029
		/*
1030 1031 1032
		 * __ieee80211_parse_tx_radiotap has now removed
		 * the radiotap header that was present and pre-filled
		 * 'tx' with tx control information.
1033 1034 1035
		 */
	}

1036 1037 1038 1039 1040 1041 1042
	/*
	 * 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;

1043 1044
	hdr = (struct ieee80211_hdr *) skb->data;

1045
	tx->sta = sta_info_get(local, hdr->addr1);
1046

1047 1048
	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)) {
1049
		unsigned long flags;
1050 1051
		struct tid_ampdu_tx *tid_tx;

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1052 1053 1054
		qc = ieee80211_get_qos_ctl(hdr);
		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;

1055
		spin_lock_irqsave(&tx->sta->lock, flags);
1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069
		/*
		 * 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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1070
		state = &tx->sta->ampdu_mlme.tid_state_tx[tid];
1071
		if (*state == HT_AGG_STATE_OPERATIONAL) {
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1072
			info->flags |= IEEE80211_TX_CTL_AMPDU;
1073 1074 1075 1076 1077 1078
		} 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);
		}
1079
		spin_unlock_irqrestore(&tx->sta->lock, flags);
1080 1081 1082

		if (unlikely(queued))
			return TX_QUEUED;
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1083 1084
	}

1085
	if (is_multicast_ether_addr(hdr->addr1)) {
1086
		tx->flags &= ~IEEE80211_TX_UNICAST;
1087
		info->flags |= IEEE80211_TX_CTL_NO_ACK;
1088
	} else {
1089
		tx->flags |= IEEE80211_TX_UNICAST;
1090
		info->flags &= ~IEEE80211_TX_CTL_NO_ACK;
1091
	}
1092

1093 1094
	if (tx->flags & IEEE80211_TX_FRAGMENTED) {
		if ((tx->flags & IEEE80211_TX_UNICAST) &&
1095
		    skb->len + FCS_LEN > local->hw.wiphy->frag_threshold &&
1096
		    !(info->flags & IEEE80211_TX_CTL_AMPDU))
1097
			tx->flags |= IEEE80211_TX_FRAGMENTED;
1098
		else
1099
			tx->flags &= ~IEEE80211_TX_FRAGMENTED;
1100 1101
	}

1102
	if (!tx->sta)
1103
		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1104
	else if (test_and_clear_sta_flags(tx->sta, WLAN_STA_CLEAR_PS_FILT))
1105
		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1106

1107
	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1108 1109 1110 1111
	if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
		u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
		tx->ethertype = (pos[0] << 8) | pos[1];
	}
1112
	info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1113

1114
	return TX_CONTINUE;
1115 1116
}

1117
/*
1118 1119
 * NB: @tx is uninitialised when passed in here
 */
1120 1121 1122
static int ieee80211_tx_prepare(struct ieee80211_local *local,
				struct ieee80211_tx_data *tx,
				struct sk_buff *skb)
1123 1124 1125
{
	struct net_device *dev;

1126
	dev = dev_get_by_index(&init_net, skb->iif);
1127
	if (unlikely(dev && !is_ieee80211_device(local, dev))) {
1128 1129 1130 1131 1132
		dev_put(dev);
		dev = NULL;
	}
	if (unlikely(!dev))
		return -ENODEV;
1133 1134 1135 1136 1137 1138 1139 1140
	/*
	 * initialises tx with control
	 *
	 * return value is safe to ignore here because this function
	 * can only be invoked for multicast frames
	 *
	 * XXX: clean up
	 */
1141
	__ieee80211_tx_prepare(tx, skb, dev);
1142
	dev_put(dev);
1143 1144 1145
	return 0;
}

J
Johannes Berg 已提交
1146
static int __ieee80211_tx(struct ieee80211_local *local,
1147 1148
			  struct sk_buff **skbp,
			  struct sta_info *sta)
1149
{
1150
	struct sk_buff *skb = *skbp, *next;
1151
	struct ieee80211_tx_info *info;
1152
	int ret, len;
J
Johannes Berg 已提交
1153
	bool fragm = false;
1154

J
Johannes Berg 已提交
1155 1156 1157
	local->mdev->trans_start = jiffies;

	while (skb) {
1158 1159
		if (ieee80211_queue_stopped(&local->hw,
					    skb_get_queue_mapping(skb)))
1160
			return IEEE80211_TX_PENDING;
1161

1162 1163 1164
		info = IEEE80211_SKB_CB(skb);

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

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

1182 1183 1184
	return IEEE80211_TX_OK;
}

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

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

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

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

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

	return 0;
}

1232 1233
static void ieee80211_tx(struct net_device *dev, struct sk_buff *skb,
			 bool txpending)
1234 1235 1236
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct sta_info *sta;
1237
	struct ieee80211_tx_data tx;
1238
	ieee80211_tx_result res_prepare;
1239
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1240 1241 1242
	struct sk_buff *next;
	unsigned long flags;
	int ret, retries;
1243
	u16 queue;
1244

1245 1246
	queue = skb_get_queue_mapping(skb);

1247
	WARN_ON(!txpending && !skb_queue_empty(&local->pending[queue]));
1248 1249 1250

	if (unlikely(skb->len < 10)) {
		dev_kfree_skb(skb);
1251
		return;
1252 1253
	}

1254 1255
	rcu_read_lock();

1256
	/* initialises tx */
1257
	res_prepare = __ieee80211_tx_prepare(&tx, skb, dev);
1258

1259
	if (unlikely(res_prepare == TX_DROP)) {
1260
		dev_kfree_skb(skb);
1261
		rcu_read_unlock();
1262 1263 1264 1265
		return;
	} else if (unlikely(res_prepare == TX_QUEUED)) {
		rcu_read_unlock();
		return;
1266 1267 1268
	}

	sta = tx.sta;
1269
	tx.channel = local->hw.conf.channel;
1270
	info->band = tx.channel->band;
1271

1272 1273
	if (invoke_tx_handlers(&tx))
		goto out;
1274

1275 1276
	retries = 0;
 retry:
1277
	ret = __ieee80211_tx(local, &tx.skb, tx.sta);
1278 1279 1280 1281
	switch (ret) {
	case IEEE80211_TX_OK:
		break;
	case IEEE80211_TX_AGAIN:
1282 1283 1284 1285 1286
		/*
		 * 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.
		 */
1287 1288 1289 1290 1291
		if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
			goto drop;
		/* fall through */
	case IEEE80211_TX_PENDING:
		skb = tx.skb;
1292

1293
		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1294

1295 1296 1297 1298
		if (__netif_subqueue_stopped(local->mdev, queue)) {
			do {
				next = skb->next;
				skb->next = NULL;
1299 1300 1301 1302 1303 1304
				if (unlikely(txpending))
					skb_queue_head(&local->pending[queue],
						       skb);
				else
					skb_queue_tail(&local->pending[queue],
						       skb);
1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323
			} 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;
1324 1325 1326
			goto retry;
		}
	}
1327
 out:
1328
	rcu_read_unlock();
1329
	return;
1330 1331

 drop:
1332
	rcu_read_unlock();
J
Johannes Berg 已提交
1333 1334 1335 1336 1337 1338 1339

	skb = tx.skb;
	while (skb) {
		next = skb->next;
		dev_kfree_skb(skb);
		skb = next;
	}
1340 1341 1342 1343
}

/* device xmit handlers */

1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382
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;
}

1383
int ieee80211_master_start_xmit(struct sk_buff *skb, struct net_device *dev)
1384
{
1385 1386
	struct ieee80211_master_priv *mpriv = netdev_priv(dev);
	struct ieee80211_local *local = mpriv->local;
1387
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1388
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1389 1390 1391
	struct net_device *odev = NULL;
	struct ieee80211_sub_if_data *osdata;
	int headroom;
1392
	bool may_encrypt;
1393 1394 1395 1396 1397
	enum {
		NOT_MONITOR,
		FOUND_SDATA,
		UNKNOWN_ADDRESS,
	} monitor_iface = NOT_MONITOR;
1398

1399 1400
	if (skb->iif)
		odev = dev_get_by_index(&init_net, skb->iif);
1401
	if (unlikely(odev && !is_ieee80211_device(local, odev))) {
1402 1403 1404 1405 1406 1407 1408 1409 1410
		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);
1411
		return NETDEV_TX_OK;
1412
	}
1413

1414
	if ((local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) &&
1415
	    local->hw.conf.dynamic_ps_timeout > 0) {
1416 1417 1418 1419 1420 1421 1422 1423
		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 +
1424
		        msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
1425 1426
	}

1427 1428 1429 1430
	memset(info, 0, sizeof(*info));

	info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;

1431 1432
	osdata = IEEE80211_DEV_TO_SUB_IF(odev);

1433 1434
	if (ieee80211_vif_is_mesh(&osdata->vif) &&
	    ieee80211_is_data(hdr->frame_control)) {
1435 1436 1437
		if (is_multicast_ether_addr(hdr->addr3))
			memcpy(hdr->addr1, hdr->addr3, ETH_ALEN);
		else
1438 1439
			if (mesh_nexthop_lookup(skb, osdata)) {
				dev_put(odev);
1440
				return NETDEV_TX_OK;
1441
			}
1442 1443 1444
		if (memcmp(odev->dev_addr, hdr->addr4, ETH_ALEN) != 0)
			IEEE80211_IFSTA_MESH_CTR_INC(&osdata->u.mesh,
							    fwded_frames);
1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473
	} 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;
1474 1475
				if (sdata->vif.type != NL80211_IFTYPE_AP)
					continue;
1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488
				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();
		}
1489 1490
	}

1491
	may_encrypt = !skb->do_not_encrypt;
1492 1493 1494 1495 1496 1497 1498 1499 1500 1501

	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);
1502
		return NETDEV_TX_OK;
1503 1504
	}

1505 1506 1507 1508
	if (osdata->vif.type == NL80211_IFTYPE_AP_VLAN)
		osdata = container_of(osdata->bss,
				      struct ieee80211_sub_if_data,
				      u.ap);
1509 1510
	if (likely(monitor_iface != UNKNOWN_ADDRESS))
		info->control.vif = &osdata->vif;
1511 1512

	ieee80211_tx(odev, skb, false);
1513 1514
	dev_put(odev);

1515
	return NETDEV_TX_OK;
1516 1517 1518 1519 1520 1521
}

int ieee80211_monitor_start_xmit(struct sk_buff *skb,
				 struct net_device *dev)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1522
	struct ieee80211_channel *chan = local->hw.conf.channel;
1523 1524
	struct ieee80211_radiotap_header *prthdr =
		(struct ieee80211_radiotap_header *)skb->data;
1525
	u16 len_rthdr;
1526

1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546
	/*
	 * 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;

1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560
	/* 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 */
1561 1562 1563

	skb->dev = local->mdev;

1564
	/* needed because we set skb device to master */
1565
	skb->iif = dev->ifindex;
1566

1567 1568 1569
	/* sometimes we do encrypt injected frames, will be fixed
	 * up in radiotap parser if not wanted */
	skb->do_not_encrypt = 0;
1570 1571 1572 1573 1574 1575 1576

	/*
	 * 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
	 */
1577
	skb_set_mac_header(skb, len_rthdr);
1578
	/*
1579 1580
	 * 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
1581
	 */
1582 1583
	skb_set_network_header(skb, len_rthdr);
	skb_set_transport_header(skb, len_rthdr);
1584

1585 1586
	/* pass the radiotap header up to the next stage intact */
	dev_queue_xmit(skb);
1587
	return NETDEV_TX_OK;
1588 1589 1590 1591

fail:
	dev_kfree_skb(skb);
	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611
}

/**
 * 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)
{
1612 1613
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	struct ieee80211_local *local = sdata->local;
1614
	int ret = 1, head_need;
1615 1616
	u16 ethertype, hdrlen,  meshhdrlen = 0;
	__le16 fc;
1617
	struct ieee80211_hdr hdr;
1618
	struct ieee80211s_hdr mesh_hdr;
1619 1620
	const u8 *encaps_data;
	int encaps_len, skip_header_bytes;
1621
	int nh_pos, h_pos;
1622
	struct sta_info *sta;
1623
	u32 sta_flags = 0;
1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635

	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];
1636
	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
1637

1638
	switch (sdata->vif.type) {
1639 1640
	case NL80211_IFTYPE_AP:
	case NL80211_IFTYPE_AP_VLAN:
1641
		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1642 1643 1644 1645 1646
		/* 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;
1647
		break;
1648
	case NL80211_IFTYPE_WDS:
1649
		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1650 1651 1652 1653 1654 1655
		/* 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;
1656
		break;
1657
#ifdef CONFIG_MAC80211_MESH
1658
	case NL80211_IFTYPE_MESH_POINT:
1659
		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1660
		if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
1661
			/* Do not send frames with mesh_ttl == 0 */
1662
			sdata->u.mesh.mshstats.dropped_frames_ttl++;
1663 1664
			ret = 0;
			goto fail;
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 1700 1701 1702 1703
		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;
		}
1704 1705 1706
		hdrlen = 30;
		break;
#endif
1707
	case NL80211_IFTYPE_STATION:
1708
		fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1709
		/* BSSID SA DA */
1710
		memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1711 1712 1713
		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
		memcpy(hdr.addr3, skb->data, ETH_ALEN);
		hdrlen = 24;
1714
		break;
1715
	case NL80211_IFTYPE_ADHOC:
1716 1717 1718
		/* DA SA BSSID */
		memcpy(hdr.addr1, skb->data, ETH_ALEN);
		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1719
		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
1720
		hdrlen = 24;
1721 1722
		break;
	default:
1723 1724 1725 1726
		ret = 0;
		goto fail;
	}

1727 1728 1729 1730 1731 1732
	/*
	 * 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)) {
1733
		rcu_read_lock();
1734
		sta = sta_info_get(local, hdr.addr1);
1735
		if (sta)
1736
			sta_flags = get_sta_flags(sta);
1737
		rcu_read_unlock();
1738 1739
	}

1740
	/* receiver and we are QoS enabled, use a QoS type frame */
1741
	if ((sta_flags & WLAN_STA_WME) && local->hw.queues >= 4) {
1742
		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1743 1744 1745 1746
		hdrlen += 2;
	}

	/*
1747 1748
	 * Drop unicast frames to unauthorised stations unless they are
	 * EAPOL frames from the local station.
1749
	 */
1750 1751
	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
		unlikely(!is_multicast_ether_addr(hdr.addr1) &&
1752 1753
		      !(sta_flags & WLAN_STA_AUTHORIZED) &&
		      !(ethertype == ETH_P_PAE &&
1754 1755 1756 1757
		       compare_ether_addr(dev->dev_addr,
					  skb->data + ETH_ALEN) == 0))) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
		if (net_ratelimit())
1758
			printk(KERN_DEBUG "%s: dropped frame to %pM"
1759
			       " (unauthorized port)\n", dev->name,
1760
			       hdr.addr1);
1761 1762 1763 1764 1765 1766 1767 1768
#endif

		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);

		ret = 0;
		goto fail;
	}

1769
	hdr.frame_control = fc;
1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790
	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;

1791
	head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
1792

1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803
	/*
	 * 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.
	 */
1804

1805
	if (head_need > 0 || skb_cloned(skb)) {
1806 1807 1808 1809
		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))
1810 1811 1812 1813 1814 1815 1816 1817
			goto fail;
	}

	if (encaps_data) {
		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
		nh_pos += encaps_len;
		h_pos += encaps_len;
	}
1818

1819 1820 1821 1822 1823 1824
	if (meshhdrlen > 0) {
		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
		nh_pos += meshhdrlen;
		h_pos += meshhdrlen;
	}

1825
	if (ieee80211_is_data_qos(fc)) {
1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837
		__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);

1838 1839 1840
	nh_pos += hdrlen;
	h_pos += hdrlen;

1841
	skb->iif = dev->ifindex;
1842

1843
	skb->dev = local->mdev;
1844 1845
	dev->stats.tx_packets++;
	dev->stats.tx_bytes += skb->len;
1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866

	/* 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;
}


1867 1868 1869 1870
/*
 * ieee80211_clear_tx_pending may not be called in a context where
 * it is possible that it packets could come in again.
 */
1871 1872
void ieee80211_clear_tx_pending(struct ieee80211_local *local)
{
J
Johannes Berg 已提交
1873
	int i;
1874

1875 1876
	for (i = 0; i < local->hw.queues; i++)
		skb_queue_purge(&local->pending[i]);
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 1923 1924 1925 1926
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;
}

1927 1928 1929 1930
/*
 * Transmit all pending packets. Called from tasklet, locks master device
 * TX lock so that no new packets can come in.
 */
1931 1932 1933 1934
void ieee80211_tx_pending(unsigned long data)
{
	struct ieee80211_local *local = (struct ieee80211_local *)data;
	struct net_device *dev = local->mdev;
1935
	unsigned long flags;
1936
	int i;
1937
	bool next;
1938

1939
	rcu_read_lock();
1940
	netif_tx_lock_bh(dev);
1941

1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955
	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)
1956
			continue;
1957

1958 1959 1960 1961 1962
		/*
		 * 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
		 */
1963 1964
		netif_start_subqueue(local->mdev, i);

1965
		while (!skb_queue_empty(&local->pending[i])) {
1966
			struct sk_buff *skb = skb_dequeue(&local->pending[i]);
1967

1968
			if (!ieee80211_tx_pending_skb(local, skb)) {
1969
				skb_queue_head(&local->pending[i], skb);
1970 1971
				break;
			}
1972
		}
1973 1974 1975 1976 1977

		/* 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);
1978
	}
1979

1980
	netif_tx_unlock_bh(dev);
1981
	rcu_read_unlock();
1982 1983 1984 1985
}

/* functions for drivers to get certain frames */

R
Rami Rosen 已提交
1986
static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss,
1987 1988
				     struct sk_buff *skb,
				     struct beacon_data *beacon)
1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
{
	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)
2003
		bss->dtim_count = beacon->dtim_period - 1;
2004 2005 2006 2007 2008 2009 2010
	else
		bss->dtim_count--;

	tim = pos = (u8 *) skb_put(skb, 6);
	*pos++ = WLAN_EID_TIM;
	*pos++ = 4;
	*pos++ = bss->dtim_count;
2011
	*pos++ = beacon->dtim_period;
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 2044 2045 2046 2047

	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 */
	}
}

2048
struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
2049
				     struct ieee80211_vif *vif)
2050 2051
{
	struct ieee80211_local *local = hw_to_local(hw);
2052
	struct sk_buff *skb = NULL;
2053
	struct ieee80211_tx_info *info;
2054 2055
	struct ieee80211_sub_if_data *sdata = NULL;
	struct ieee80211_if_ap *ap = NULL;
2056
	struct beacon_data *beacon;
2057
	struct ieee80211_supported_band *sband;
2058
	enum ieee80211_band band = local->hw.conf.channel->band;
2059

2060
	sband = local->hw.wiphy->bands[band];
2061 2062

	rcu_read_lock();
2063

2064
	sdata = vif_to_sdata(vif);
2065

2066
	if (sdata->vif.type == NL80211_IFTYPE_AP) {
2067 2068
		ap = &sdata->u.ap;
		beacon = rcu_dereference(ap->beacon);
J
Johannes Berg 已提交
2069 2070 2071 2072 2073 2074 2075 2076 2077 2078
		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;
2079

J
Johannes Berg 已提交
2080 2081 2082
			skb_reserve(skb, local->tx_headroom);
			memcpy(skb_put(skb, beacon->head_len), beacon->head,
			       beacon->head_len);
2083

2084 2085 2086 2087 2088 2089 2090 2091
			/*
			 * 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
2092
				ieee80211_beacon_add_tim(ap, skb, beacon);
2093 2094 2095 2096
			} else {
				unsigned long flags;

				spin_lock_irqsave(&local->sta_lock, flags);
R
Rami Rosen 已提交
2097
				ieee80211_beacon_add_tim(ap, skb, beacon);
2098 2099
				spin_unlock_irqrestore(&local->sta_lock, flags);
			}
2100

J
Johannes Berg 已提交
2101 2102 2103
			if (beacon->tail)
				memcpy(skb_put(skb, beacon->tail_len),
				       beacon->tail, beacon->tail_len);
2104 2105
		} else
			goto out;
2106
	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
2107
		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2108
		struct ieee80211_hdr *hdr;
2109
		struct sk_buff *presp = rcu_dereference(ifibss->presp);
2110

2111
		if (!presp)
2112 2113
			goto out;

2114
		skb = skb_copy(presp, GFP_ATOMIC);
2115 2116 2117 2118
		if (!skb)
			goto out;

		hdr = (struct ieee80211_hdr *) skb->data;
2119 2120
		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
						 IEEE80211_STYPE_BEACON);
J
Johannes Berg 已提交
2121
	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2122 2123 2124
		struct ieee80211_mgmt *mgmt;
		u8 *pos;

J
Johannes Berg 已提交
2125 2126 2127 2128 2129 2130 2131 2132 2133
		/* 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));
2134 2135
		mgmt->frame_control =
		    cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
J
Johannes Berg 已提交
2136 2137 2138 2139
		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 =
2140
			cpu_to_le16(sdata->vif.bss_conf.beacon_int);
J
Johannes Berg 已提交
2141 2142 2143 2144 2145 2146
		mgmt->u.beacon.capab_info = 0x0; /* 0x0 for MPs */

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

2147
		mesh_mgmt_ies_add(skb, sdata);
2148 2149
	} else {
		WARN_ON(1);
2150
		goto out;
2151 2152
	}

2153 2154
	info = IEEE80211_SKB_CB(skb);

2155 2156
	skb->do_not_encrypt = 1;

2157
	info->band = band;
2158 2159 2160 2161 2162 2163 2164 2165 2166 2167
	/*
	 * 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);
2168 2169

	info->control.vif = vif;
2170 2171 2172 2173

	info->flags |= IEEE80211_TX_CTL_NO_ACK;
	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
	info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
2174
 out:
2175
	rcu_read_unlock();
2176 2177 2178 2179
	return skb;
}
EXPORT_SYMBOL(ieee80211_beacon_get);

2180
void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2181
		       const void *frame, size_t frame_len,
2182
		       const struct ieee80211_tx_info *frame_txctl,
2183 2184 2185 2186
		       struct ieee80211_rts *rts)
{
	const struct ieee80211_hdr *hdr = frame;

2187 2188
	rts->frame_control =
	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2189 2190
	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
					       frame_txctl);
2191 2192 2193 2194 2195
	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
}
EXPORT_SYMBOL(ieee80211_rts_get);

2196
void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2197
			     const void *frame, size_t frame_len,
2198
			     const struct ieee80211_tx_info *frame_txctl,
2199 2200 2201 2202
			     struct ieee80211_cts *cts)
{
	const struct ieee80211_hdr *hdr = frame;

2203 2204
	cts->frame_control =
	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2205 2206
	cts->duration = ieee80211_ctstoself_duration(hw, vif,
						     frame_len, frame_txctl);
2207 2208 2209 2210 2211
	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
}
EXPORT_SYMBOL(ieee80211_ctstoself_get);

struct sk_buff *
2212
ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2213
			  struct ieee80211_vif *vif)
2214 2215
{
	struct ieee80211_local *local = hw_to_local(hw);
2216
	struct sk_buff *skb = NULL;
2217
	struct sta_info *sta;
2218
	struct ieee80211_tx_data tx;
2219 2220
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_if_ap *bss = NULL;
2221
	struct beacon_data *beacon;
2222
	struct ieee80211_tx_info *info;
2223

2224
	sdata = vif_to_sdata(vif);
2225
	bss = &sdata->u.ap;
2226 2227

	if (!bss)
2228 2229
		return NULL;

2230 2231 2232
	rcu_read_lock();
	beacon = rcu_dereference(bss->beacon);

2233
	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
2234
		goto out;
2235

2236
	if (bss->dtim_count != 0)
2237
		goto out; /* send buffered bc/mc only after DTIM beacon */
2238

2239 2240 2241
	while (1) {
		skb = skb_dequeue(&bss->ps_bc_buf);
		if (!skb)
2242
			goto out;
2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254
		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);
		}

2255
		if (!ieee80211_tx_prepare(local, &tx, skb))
2256 2257 2258
			break;
		dev_kfree_skb_any(skb);
	}
2259 2260 2261

	info = IEEE80211_SKB_CB(skb);

2262
	sta = tx.sta;
2263 2264
	tx.flags |= IEEE80211_TX_PS_BUFFERED;
	tx.channel = local->hw.conf.channel;
2265
	info->band = tx.channel->band;
2266

2267
	if (invoke_tx_handlers(&tx))
2268
		skb = NULL;
2269
 out:
2270
	rcu_read_unlock();
2271 2272 2273 2274

	return skb;
}
EXPORT_SYMBOL(ieee80211_get_buffered_bc);