tx.c 61.8 KB
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/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 *
 * Transmit and frame generation functions.
 */

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

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

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

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

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

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

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

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

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

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

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	return cpu_to_le16(dur);
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}

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

/* tx handlers */

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

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

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

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	return TX_CONTINUE;
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}

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

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

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

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

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

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

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

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

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

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

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

	return 1;
}

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

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

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

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

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static ieee80211_tx_result debug_noinline
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ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
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{
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	struct ieee80211_key *key = NULL;
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	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
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	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
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	if (unlikely(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;

566 567 568 569 570
	if (is_multicast_ether_addr(hdr->addr1)) {
		/*
		 * XXX: verify the rate is in the basic rateset
		 */
		return TX_CONTINUE;
571 572
	}

573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597
	/*
	 * 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;
598 599
	}

600 601 602 603 604 605 606 607 608 609 610 611 612 613
	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;
		}
614

615 616 617 618 619 620 621 622
		/*
		 * 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;
		}
623

624 625 626 627
		/* set up RTS protection if desired */
		if (rts)
			info->control.rates[i].flags |=
				IEEE80211_TX_RC_USE_RTS_CTS;
628

629
		/* RC is busted */
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		if (WARN_ON_ONCE(info->control.rates[i].idx >=
				 sband->n_bitrates)) {
632 633
			info->control.rates[i].idx = -1;
			continue;
634
		}
635

636 637 638 639 640 641 642 643 644 645 646 647 648
		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;
649 650
	}

651 652 653 654 655 656 657 658
	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);

659
	if (tx->sta)
660
		info->control.sta = &tx->sta->sta;
661 662 663 664

	return TX_CONTINUE;
}

665 666 667 668 669 670 671 672 673
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;

674 675 676 677 678 679 680 681
	/*
	 * 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;

682 683 684 685 686 687
	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.
	 */
693
	if (!ieee80211_is_data_qos(hdr->frame_control)) {
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		/* driver should assign sequence number */
695
		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;
700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724
		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;
}

772
static ieee80211_tx_result debug_noinline
773 774
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;
778
	int frag_threshold = tx->local->hw.wiphy->frag_threshold;
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	int hdrlen;
	int fragnum;
781 782 783 784

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

785 786
	/*
	 * Warn when submitting a fragmented A-MPDU frame and drop it.
787 788
	 * This scenario is handled in __ieee80211_tx_prepare but extra
	 * caution taken here as fragmented ampdu may cause Tx stop.
789
	 */
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790
	if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
791 792
		return TX_DROP;

793
	hdrlen = ieee80211_hdrlen(hdr->frame_control);
794

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795
	/* internal error, why is TX_FRAGMENTED set? */
796
	if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
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797
		return TX_DROP;
798

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799 800 801 802 803 804 805 806 807 808
	/*
	 * 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;
809

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810 811 812 813 814
	/* update duration/seq/flags of fragments */
	fragnum = 0;
	do {
		int next_len;
		const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
815

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816 817
		hdr = (void *)skb->data;
		info = IEEE80211_SKB_CB(skb);
818

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819 820 821
		if (skb->next) {
			hdr->frame_control |= morefrags;
			next_len = skb->next->len;
822 823 824 825 826 827 828 829 830 831
			/*
			 * 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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832 833 834
		} else {
			hdr->frame_control &= ~morefrags;
			next_len = 0;
835
		}
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836 837 838 839
		hdr->duration_id = ieee80211_duration(tx, 0, next_len);
		hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
		fragnum++;
	} while ((skb = skb->next));
840

841
	return TX_CONTINUE;
842 843
}

844
static ieee80211_tx_result debug_noinline
845 846 847 848 849 850 851 852 853 854 855 856
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);
857 858
	case ALG_AES_CMAC:
		return ieee80211_crypto_aes_cmac_encrypt(tx);
859 860 861 862 863 864 865
	}

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

866
static ieee80211_tx_result debug_noinline
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867 868
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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874 875
	do {
		hdr = (void *) skb->data;
876 877
		if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
			break; /* must not overwrite AID */
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		next_len = skb->next ? skb->next->len : 0;
		group_addr = is_multicast_ether_addr(hdr->addr1);
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		hdr->duration_id =
			ieee80211_duration(tx, group_addr, next_len);
	} while ((skb = skb->next));
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	return TX_CONTINUE;
}

888
static ieee80211_tx_result debug_noinline
889
ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
890
{
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	struct sk_buff *skb = tx->skb;
892

893 894
	if (!tx->sta)
		return TX_CONTINUE;
895

896
	tx->sta->tx_packets++;
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	do {
		tx->sta->tx_fragments++;
		tx->sta->tx_bytes += skb->len;
	} while ((skb = skb->next));
901

902
	return TX_CONTINUE;
903 904 905 906 907 908 909 910
}

/* actual transmit path */

/*
 * deal with packet injection down monitor interface
 * with Radiotap Header -- only called for monitor mode interface
 */
911
static ieee80211_tx_result
912
__ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
913
			      struct sk_buff *skb)
914 915 916 917 918 919 920 921 922 923 924 925
{
	/*
	 * 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;
926
	struct ieee80211_supported_band *sband;
927 928
	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len);

929
	sband = tx->local->hw.wiphy->bands[tx->channel->band];
930

931
	skb->do_not_encrypt = 1;
932
	tx->flags &= ~IEEE80211_TX_FRAGMENTED;
933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963

	/*
	 * 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))
964
					return TX_DROP;
965 966 967

				skb_trim(skb, skb->len - FCS_LEN);
			}
968
			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
969
				tx->skb->do_not_encrypt = 0;
970
			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
971
				tx->flags |= IEEE80211_TX_FRAGMENTED;
972 973
			break;

974 975 976 977 978 979
		/*
		 * Please update the file
		 * Documentation/networking/mac80211-injection.txt
		 * when parsing new fields here.
		 */

980 981 982 983 984 985
		default:
			break;
		}
	}

	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
986
		return TX_DROP;
987 988 989 990 991 992 993 994

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

995
	return TX_CONTINUE;
996 997
}

998 999 1000
/*
 * initialises @tx
 */
1001
static ieee80211_tx_result
1002
__ieee80211_tx_prepare(struct ieee80211_tx_data *tx,
1003
		       struct sk_buff *skb,
1004
		       struct net_device *dev)
1005 1006
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1007
	struct ieee80211_hdr *hdr;
1008
	struct ieee80211_sub_if_data *sdata;
1009
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
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	int hdrlen, tid;
	u8 *qc, *state;
1012
	bool queued = false;
1013 1014 1015 1016 1017 1018

	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);
1019
	tx->channel = local->hw.conf.channel;
1020
	/*
1021 1022
	 * Set this flag (used below to indicate "automatic fragmentation"),
	 * it will be cleared/left by radiotap as desired.
1023
	 */
1024
	tx->flags |= IEEE80211_TX_FRAGMENTED;
1025 1026 1027

	/* process and remove the injection radiotap header */
	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1028
	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED)) {
1029 1030
		if (__ieee80211_parse_tx_radiotap(tx, skb) == TX_DROP)
			return TX_DROP;
1031

1032
		/*
1033 1034 1035
		 * __ieee80211_parse_tx_radiotap has now removed
		 * the radiotap header that was present and pre-filled
		 * 'tx' with tx control information.
1036 1037 1038
		 */
	}

1039 1040 1041 1042 1043 1044 1045
	/*
	 * 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;

1046 1047
	hdr = (struct ieee80211_hdr *) skb->data;

1048
	tx->sta = sta_info_get(local, hdr->addr1);
1049

1050 1051
	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)) {
1052
		unsigned long flags;
1053 1054
		struct tid_ampdu_tx *tid_tx;

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1055 1056 1057
		qc = ieee80211_get_qos_ctl(hdr);
		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;

1058
		spin_lock_irqsave(&tx->sta->lock, flags);
1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072
		/*
		 * 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];
1074
		if (*state == HT_AGG_STATE_OPERATIONAL) {
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1075
			info->flags |= IEEE80211_TX_CTL_AMPDU;
1076 1077 1078 1079 1080 1081
		} 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);
		}
1082
		spin_unlock_irqrestore(&tx->sta->lock, flags);
1083 1084 1085

		if (unlikely(queued))
			return TX_QUEUED;
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1086 1087
	}

1088
	if (is_multicast_ether_addr(hdr->addr1)) {
1089
		tx->flags &= ~IEEE80211_TX_UNICAST;
1090
		info->flags |= IEEE80211_TX_CTL_NO_ACK;
1091
	} else {
1092
		tx->flags |= IEEE80211_TX_UNICAST;
1093 1094 1095 1096
		if (unlikely(local->wifi_wme_noack_test))
			info->flags |= IEEE80211_TX_CTL_NO_ACK;
		else
			info->flags &= ~IEEE80211_TX_CTL_NO_ACK;
1097
	}
1098

1099 1100
	if (tx->flags & IEEE80211_TX_FRAGMENTED) {
		if ((tx->flags & IEEE80211_TX_UNICAST) &&
1101
		    skb->len + FCS_LEN > local->hw.wiphy->frag_threshold &&
1102
		    !(info->flags & IEEE80211_TX_CTL_AMPDU))
1103
			tx->flags |= IEEE80211_TX_FRAGMENTED;
1104
		else
1105
			tx->flags &= ~IEEE80211_TX_FRAGMENTED;
1106 1107
	}

1108
	if (!tx->sta)
1109
		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1110
	else if (test_and_clear_sta_flags(tx->sta, WLAN_STA_CLEAR_PS_FILT))
1111
		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1112

1113
	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1114 1115 1116 1117
	if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
		u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
		tx->ethertype = (pos[0] << 8) | pos[1];
	}
1118
	info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1119

1120
	return TX_CONTINUE;
1121 1122
}

1123
/*
1124 1125
 * NB: @tx is uninitialised when passed in here
 */
1126 1127 1128
static int ieee80211_tx_prepare(struct ieee80211_local *local,
				struct ieee80211_tx_data *tx,
				struct sk_buff *skb)
1129 1130 1131
{
	struct net_device *dev;

1132
	dev = dev_get_by_index(&init_net, skb->iif);
1133
	if (unlikely(dev && !is_ieee80211_device(local, dev))) {
1134 1135 1136 1137 1138
		dev_put(dev);
		dev = NULL;
	}
	if (unlikely(!dev))
		return -ENODEV;
1139 1140 1141 1142 1143 1144 1145 1146
	/*
	 * initialises tx with control
	 *
	 * return value is safe to ignore here because this function
	 * can only be invoked for multicast frames
	 *
	 * XXX: clean up
	 */
1147
	__ieee80211_tx_prepare(tx, skb, dev);
1148
	dev_put(dev);
1149 1150 1151
	return 0;
}

J
Johannes Berg 已提交
1152
static int __ieee80211_tx(struct ieee80211_local *local,
1153 1154
			  struct sk_buff **skbp,
			  struct sta_info *sta)
1155
{
1156
	struct sk_buff *skb = *skbp, *next;
1157
	struct ieee80211_tx_info *info;
1158
	int ret, len;
J
Johannes Berg 已提交
1159
	bool fragm = false;
1160

J
Johannes Berg 已提交
1161 1162 1163
	local->mdev->trans_start = jiffies;

	while (skb) {
1164 1165
		if (ieee80211_queue_stopped(&local->hw,
					    skb_get_queue_mapping(skb)))
1166
			return IEEE80211_TX_PENDING;
1167

1168 1169 1170
		info = IEEE80211_SKB_CB(skb);

		if (fragm)
1171
			info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
1172
					 IEEE80211_TX_CTL_FIRST_FRAGMENT);
1173

J
Johannes Berg 已提交
1174
		next = skb->next;
1175
		len = skb->len;
1176
		ret = drv_tx(local, skb);
1177 1178 1179 1180
		if (WARN_ON(ret != NETDEV_TX_OK && skb->len != len)) {
			dev_kfree_skb(skb);
			ret = NETDEV_TX_OK;
		}
J
Johannes Berg 已提交
1181 1182
		if (ret != NETDEV_TX_OK)
			return IEEE80211_TX_AGAIN;
1183
		*skbp = skb = next;
J
Johannes Berg 已提交
1184 1185
		ieee80211_led_tx(local, 1);
		fragm = true;
1186
	}
J
Johannes Berg 已提交
1187

1188 1189 1190
	return IEEE80211_TX_OK;
}

1191 1192 1193 1194 1195 1196 1197 1198 1199
/*
 * 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;

1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210
#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)
1211
	CALL_TXH(ieee80211_tx_h_sequence)
1212 1213 1214 1215 1216 1217
	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
1218

1219
 txh_done:
1220
	if (unlikely(res == TX_DROP)) {
1221
		I802_DEBUG_INC(tx->local->tx_handlers_drop);
J
Johannes Berg 已提交
1222 1223 1224 1225 1226 1227 1228
		while (skb) {
			struct sk_buff *next;

			next = skb->next;
			dev_kfree_skb(skb);
			skb = next;
		}
1229 1230
		return -1;
	} else if (unlikely(res == TX_QUEUED)) {
1231
		I802_DEBUG_INC(tx->local->tx_handlers_queued);
1232 1233 1234 1235 1236 1237
		return -1;
	}

	return 0;
}

1238 1239
static void ieee80211_tx(struct net_device *dev, struct sk_buff *skb,
			 bool txpending)
1240 1241
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1242
	struct ieee80211_tx_data tx;
1243
	ieee80211_tx_result res_prepare;
1244
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1245 1246 1247
	struct sk_buff *next;
	unsigned long flags;
	int ret, retries;
1248
	u16 queue;
1249

1250 1251
	queue = skb_get_queue_mapping(skb);

1252
	WARN_ON(!txpending && !skb_queue_empty(&local->pending[queue]));
1253 1254 1255

	if (unlikely(skb->len < 10)) {
		dev_kfree_skb(skb);
1256
		return;
1257 1258
	}

1259 1260
	rcu_read_lock();

1261
	/* initialises tx */
1262
	res_prepare = __ieee80211_tx_prepare(&tx, skb, dev);
1263

1264
	if (unlikely(res_prepare == TX_DROP)) {
1265
		dev_kfree_skb(skb);
1266
		rcu_read_unlock();
1267 1268 1269 1270
		return;
	} else if (unlikely(res_prepare == TX_QUEUED)) {
		rcu_read_unlock();
		return;
1271 1272
	}

1273
	tx.channel = local->hw.conf.channel;
1274
	info->band = tx.channel->band;
1275

1276 1277
	if (invoke_tx_handlers(&tx))
		goto out;
1278

1279 1280
	retries = 0;
 retry:
1281
	ret = __ieee80211_tx(local, &tx.skb, tx.sta);
1282 1283 1284 1285
	switch (ret) {
	case IEEE80211_TX_OK:
		break;
	case IEEE80211_TX_AGAIN:
1286 1287 1288 1289 1290
		/*
		 * 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.
		 */
1291 1292 1293 1294 1295
		if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
			goto drop;
		/* fall through */
	case IEEE80211_TX_PENDING:
		skb = tx.skb;
1296

1297
		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1298

1299 1300 1301 1302
		if (__netif_subqueue_stopped(local->mdev, queue)) {
			do {
				next = skb->next;
				skb->next = NULL;
1303 1304 1305 1306 1307 1308
				if (unlikely(txpending))
					skb_queue_head(&local->pending[queue],
						       skb);
				else
					skb_queue_tail(&local->pending[queue],
						       skb);
1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327
			} 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;
1328 1329 1330
			goto retry;
		}
	}
1331
 out:
1332
	rcu_read_unlock();
1333
	return;
1334 1335

 drop:
1336
	rcu_read_unlock();
J
Johannes Berg 已提交
1337 1338 1339 1340 1341 1342 1343

	skb = tx.skb;
	while (skb) {
		next = skb->next;
		dev_kfree_skb(skb);
		skb = next;
	}
1344 1345 1346 1347
}

/* device xmit handlers */

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 1383 1384 1385 1386
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;
}

1387
int ieee80211_master_start_xmit(struct sk_buff *skb, struct net_device *dev)
1388
{
1389 1390
	struct ieee80211_master_priv *mpriv = netdev_priv(dev);
	struct ieee80211_local *local = mpriv->local;
1391
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1392
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1393 1394 1395
	struct net_device *odev = NULL;
	struct ieee80211_sub_if_data *osdata;
	int headroom;
1396
	bool may_encrypt;
1397 1398 1399 1400 1401
	enum {
		NOT_MONITOR,
		FOUND_SDATA,
		UNKNOWN_ADDRESS,
	} monitor_iface = NOT_MONITOR;
1402

1403 1404
	if (skb->iif)
		odev = dev_get_by_index(&init_net, skb->iif);
1405
	if (unlikely(odev && !is_ieee80211_device(local, odev))) {
1406 1407 1408 1409 1410 1411 1412 1413 1414
		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);
1415
		return NETDEV_TX_OK;
1416
	}
1417

1418
	if ((local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) &&
1419
	    local->hw.conf.dynamic_ps_timeout > 0) {
1420 1421 1422 1423 1424 1425 1426 1427
		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 +
1428
		        msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
1429 1430
	}

1431 1432 1433 1434
	memset(info, 0, sizeof(*info));

	info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;

1435 1436
	osdata = IEEE80211_DEV_TO_SUB_IF(odev);

1437 1438
	if (ieee80211_vif_is_mesh(&osdata->vif) &&
	    ieee80211_is_data(hdr->frame_control)) {
1439 1440 1441
		if (is_multicast_ether_addr(hdr->addr3))
			memcpy(hdr->addr1, hdr->addr3, ETH_ALEN);
		else
1442 1443
			if (mesh_nexthop_lookup(skb, osdata)) {
				dev_put(odev);
1444
				return NETDEV_TX_OK;
1445
			}
1446 1447 1448
		if (memcmp(odev->dev_addr, hdr->addr4, ETH_ALEN) != 0)
			IEEE80211_IFSTA_MESH_CTR_INC(&osdata->u.mesh,
							    fwded_frames);
1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477
	} 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;
1478 1479
				if (sdata->vif.type != NL80211_IFTYPE_AP)
					continue;
1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492
				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();
		}
1493 1494
	}

1495
	may_encrypt = !skb->do_not_encrypt;
1496 1497 1498 1499 1500 1501 1502 1503 1504 1505

	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);
1506
		return NETDEV_TX_OK;
1507 1508
	}

1509 1510 1511 1512
	if (osdata->vif.type == NL80211_IFTYPE_AP_VLAN)
		osdata = container_of(osdata->bss,
				      struct ieee80211_sub_if_data,
				      u.ap);
1513 1514
	if (likely(monitor_iface != UNKNOWN_ADDRESS))
		info->control.vif = &osdata->vif;
1515 1516

	ieee80211_tx(odev, skb, false);
1517 1518
	dev_put(odev);

1519
	return NETDEV_TX_OK;
1520 1521 1522 1523 1524 1525
}

int ieee80211_monitor_start_xmit(struct sk_buff *skb,
				 struct net_device *dev)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1526
	struct ieee80211_channel *chan = local->hw.conf.channel;
1527 1528
	struct ieee80211_radiotap_header *prthdr =
		(struct ieee80211_radiotap_header *)skb->data;
1529
	u16 len_rthdr;
1530

1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550
	/*
	 * 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;

1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564
	/* 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 */
1565 1566 1567

	skb->dev = local->mdev;

1568
	/* needed because we set skb device to master */
1569
	skb->iif = dev->ifindex;
1570

1571 1572 1573
	/* sometimes we do encrypt injected frames, will be fixed
	 * up in radiotap parser if not wanted */
	skb->do_not_encrypt = 0;
1574 1575 1576 1577 1578 1579 1580

	/*
	 * 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
	 */
1581
	skb_set_mac_header(skb, len_rthdr);
1582
	/*
1583 1584
	 * 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
1585
	 */
1586 1587
	skb_set_network_header(skb, len_rthdr);
	skb_set_transport_header(skb, len_rthdr);
1588

1589 1590
	/* pass the radiotap header up to the next stage intact */
	dev_queue_xmit(skb);
1591
	return NETDEV_TX_OK;
1592 1593 1594 1595

fail:
	dev_kfree_skb(skb);
	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615
}

/**
 * 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)
{
1616 1617
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
	struct ieee80211_local *local = sdata->local;
1618
	int ret = 1, head_need;
1619 1620
	u16 ethertype, hdrlen,  meshhdrlen = 0;
	__le16 fc;
1621
	struct ieee80211_hdr hdr;
1622
	struct ieee80211s_hdr mesh_hdr;
1623 1624
	const u8 *encaps_data;
	int encaps_len, skip_header_bytes;
1625
	int nh_pos, h_pos;
1626
	struct sta_info *sta;
1627
	u32 sta_flags = 0;
1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639

	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];
1640
	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
1641

1642
	switch (sdata->vif.type) {
1643 1644
	case NL80211_IFTYPE_AP:
	case NL80211_IFTYPE_AP_VLAN:
1645
		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1646 1647 1648 1649 1650
		/* 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;
1651
		break;
1652
	case NL80211_IFTYPE_WDS:
1653
		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1654 1655 1656 1657 1658 1659
		/* 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;
1660
		break;
1661
#ifdef CONFIG_MAC80211_MESH
1662
	case NL80211_IFTYPE_MESH_POINT:
1663
		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1664
		if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
1665
			/* Do not send frames with mesh_ttl == 0 */
1666
			sdata->u.mesh.mshstats.dropped_frames_ttl++;
1667 1668
			ret = 0;
			goto fail;
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 1704 1705 1706 1707
		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;
		}
1708 1709 1710
		hdrlen = 30;
		break;
#endif
1711
	case NL80211_IFTYPE_STATION:
1712
		fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1713
		/* BSSID SA DA */
1714
		memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1715 1716 1717
		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
		memcpy(hdr.addr3, skb->data, ETH_ALEN);
		hdrlen = 24;
1718
		break;
1719
	case NL80211_IFTYPE_ADHOC:
1720 1721 1722
		/* DA SA BSSID */
		memcpy(hdr.addr1, skb->data, ETH_ALEN);
		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1723
		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
1724
		hdrlen = 24;
1725 1726
		break;
	default:
1727 1728 1729 1730
		ret = 0;
		goto fail;
	}

1731 1732 1733 1734 1735 1736
	/*
	 * 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)) {
1737
		rcu_read_lock();
1738
		sta = sta_info_get(local, hdr.addr1);
1739
		if (sta)
1740
			sta_flags = get_sta_flags(sta);
1741
		rcu_read_unlock();
1742 1743
	}

1744
	/* receiver and we are QoS enabled, use a QoS type frame */
1745
	if ((sta_flags & WLAN_STA_WME) && local->hw.queues >= 4) {
1746
		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1747 1748 1749 1750
		hdrlen += 2;
	}

	/*
1751 1752
	 * Drop unicast frames to unauthorised stations unless they are
	 * EAPOL frames from the local station.
1753
	 */
1754 1755
	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
		unlikely(!is_multicast_ether_addr(hdr.addr1) &&
1756 1757
		      !(sta_flags & WLAN_STA_AUTHORIZED) &&
		      !(ethertype == ETH_P_PAE &&
1758 1759 1760 1761
		       compare_ether_addr(dev->dev_addr,
					  skb->data + ETH_ALEN) == 0))) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
		if (net_ratelimit())
1762
			printk(KERN_DEBUG "%s: dropped frame to %pM"
1763
			       " (unauthorized port)\n", dev->name,
1764
			       hdr.addr1);
1765 1766 1767 1768 1769 1770 1771 1772
#endif

		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);

		ret = 0;
		goto fail;
	}

1773
	hdr.frame_control = fc;
1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794
	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;

1795
	head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
1796

1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807
	/*
	 * 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.
	 */
1808

1809
	if (head_need > 0 || skb_cloned(skb)) {
1810 1811 1812 1813
		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))
1814 1815 1816 1817 1818 1819 1820 1821
			goto fail;
	}

	if (encaps_data) {
		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
		nh_pos += encaps_len;
		h_pos += encaps_len;
	}
1822

1823 1824 1825 1826 1827 1828
	if (meshhdrlen > 0) {
		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
		nh_pos += meshhdrlen;
		h_pos += meshhdrlen;
	}

1829
	if (ieee80211_is_data_qos(fc)) {
1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841
		__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);

1842 1843 1844
	nh_pos += hdrlen;
	h_pos += hdrlen;

1845
	skb->iif = dev->ifindex;
1846

1847
	skb->dev = local->mdev;
1848 1849
	dev->stats.tx_packets++;
	dev->stats.tx_bytes += skb->len;
1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870

	/* 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;
}


1871 1872 1873 1874
/*
 * ieee80211_clear_tx_pending may not be called in a context where
 * it is possible that it packets could come in again.
 */
1875 1876
void ieee80211_clear_tx_pending(struct ieee80211_local *local)
{
J
Johannes Berg 已提交
1877
	int i;
1878

1879 1880
	for (i = 0; i < local->hw.queues; i++)
		skb_queue_purge(&local->pending[i]);
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 1927 1928 1929 1930
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;
}

1931 1932 1933 1934
/*
 * Transmit all pending packets. Called from tasklet, locks master device
 * TX lock so that no new packets can come in.
 */
1935 1936 1937 1938
void ieee80211_tx_pending(unsigned long data)
{
	struct ieee80211_local *local = (struct ieee80211_local *)data;
	struct net_device *dev = local->mdev;
1939
	unsigned long flags;
1940
	int i;
1941
	bool next;
1942

1943
	rcu_read_lock();
1944
	netif_tx_lock_bh(dev);
1945

1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959
	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)
1960
			continue;
1961

1962 1963 1964 1965 1966
		/*
		 * 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
		 */
1967 1968
		netif_start_subqueue(local->mdev, i);

1969
		while (!skb_queue_empty(&local->pending[i])) {
1970
			struct sk_buff *skb = skb_dequeue(&local->pending[i]);
1971

1972
			if (!ieee80211_tx_pending_skb(local, skb)) {
1973
				skb_queue_head(&local->pending[i], skb);
1974 1975
				break;
			}
1976
		}
1977 1978 1979 1980 1981

		/* 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);
1982
	}
1983

1984
	netif_tx_unlock_bh(dev);
1985
	rcu_read_unlock();
1986 1987 1988 1989
}

/* functions for drivers to get certain frames */

R
Rami Rosen 已提交
1990
static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss,
1991 1992
				     struct sk_buff *skb,
				     struct beacon_data *beacon)
1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
{
	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)
2007
		bss->dtim_count = beacon->dtim_period - 1;
2008 2009 2010 2011 2012 2013 2014
	else
		bss->dtim_count--;

	tim = pos = (u8 *) skb_put(skb, 6);
	*pos++ = WLAN_EID_TIM;
	*pos++ = 4;
	*pos++ = bss->dtim_count;
2015
	*pos++ = beacon->dtim_period;
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 2048 2049 2050 2051

	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 */
	}
}

2052
struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
2053
				     struct ieee80211_vif *vif)
2054 2055
{
	struct ieee80211_local *local = hw_to_local(hw);
2056
	struct sk_buff *skb = NULL;
2057
	struct ieee80211_tx_info *info;
2058 2059
	struct ieee80211_sub_if_data *sdata = NULL;
	struct ieee80211_if_ap *ap = NULL;
2060
	struct beacon_data *beacon;
2061
	struct ieee80211_supported_band *sband;
2062
	enum ieee80211_band band = local->hw.conf.channel->band;
2063

2064
	sband = local->hw.wiphy->bands[band];
2065 2066

	rcu_read_lock();
2067

2068
	sdata = vif_to_sdata(vif);
2069

2070
	if (sdata->vif.type == NL80211_IFTYPE_AP) {
2071 2072
		ap = &sdata->u.ap;
		beacon = rcu_dereference(ap->beacon);
J
Johannes Berg 已提交
2073 2074 2075 2076 2077 2078 2079 2080 2081 2082
		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;
2083

J
Johannes Berg 已提交
2084 2085 2086
			skb_reserve(skb, local->tx_headroom);
			memcpy(skb_put(skb, beacon->head_len), beacon->head,
			       beacon->head_len);
2087

2088 2089 2090 2091 2092 2093 2094 2095
			/*
			 * 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
2096
				ieee80211_beacon_add_tim(ap, skb, beacon);
2097 2098 2099 2100
			} else {
				unsigned long flags;

				spin_lock_irqsave(&local->sta_lock, flags);
R
Rami Rosen 已提交
2101
				ieee80211_beacon_add_tim(ap, skb, beacon);
2102 2103
				spin_unlock_irqrestore(&local->sta_lock, flags);
			}
2104

J
Johannes Berg 已提交
2105 2106 2107
			if (beacon->tail)
				memcpy(skb_put(skb, beacon->tail_len),
				       beacon->tail, beacon->tail_len);
2108 2109
		} else
			goto out;
2110
	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
2111
		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2112
		struct ieee80211_hdr *hdr;
2113
		struct sk_buff *presp = rcu_dereference(ifibss->presp);
2114

2115
		if (!presp)
2116 2117
			goto out;

2118
		skb = skb_copy(presp, GFP_ATOMIC);
2119 2120 2121 2122
		if (!skb)
			goto out;

		hdr = (struct ieee80211_hdr *) skb->data;
2123 2124
		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
						 IEEE80211_STYPE_BEACON);
J
Johannes Berg 已提交
2125
	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2126 2127 2128
		struct ieee80211_mgmt *mgmt;
		u8 *pos;

J
Johannes Berg 已提交
2129 2130 2131 2132 2133 2134 2135 2136 2137
		/* 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));
2138 2139
		mgmt->frame_control =
		    cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
J
Johannes Berg 已提交
2140 2141 2142 2143
		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 =
2144
			cpu_to_le16(sdata->vif.bss_conf.beacon_int);
J
Johannes Berg 已提交
2145 2146 2147 2148 2149 2150
		mgmt->u.beacon.capab_info = 0x0; /* 0x0 for MPs */

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

2151
		mesh_mgmt_ies_add(skb, sdata);
2152 2153
	} else {
		WARN_ON(1);
2154
		goto out;
2155 2156
	}

2157 2158
	info = IEEE80211_SKB_CB(skb);

2159 2160
	skb->do_not_encrypt = 1;

2161
	info->band = band;
2162 2163 2164 2165 2166 2167 2168 2169 2170 2171
	/*
	 * 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);
2172 2173

	info->control.vif = vif;
2174 2175 2176 2177

	info->flags |= IEEE80211_TX_CTL_NO_ACK;
	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
	info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
2178
 out:
2179
	rcu_read_unlock();
2180 2181 2182 2183
	return skb;
}
EXPORT_SYMBOL(ieee80211_beacon_get);

2184
void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2185
		       const void *frame, size_t frame_len,
2186
		       const struct ieee80211_tx_info *frame_txctl,
2187 2188 2189 2190
		       struct ieee80211_rts *rts)
{
	const struct ieee80211_hdr *hdr = frame;

2191 2192
	rts->frame_control =
	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2193 2194
	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
					       frame_txctl);
2195 2196 2197 2198 2199
	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
}
EXPORT_SYMBOL(ieee80211_rts_get);

2200
void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2201
			     const void *frame, size_t frame_len,
2202
			     const struct ieee80211_tx_info *frame_txctl,
2203 2204 2205 2206
			     struct ieee80211_cts *cts)
{
	const struct ieee80211_hdr *hdr = frame;

2207 2208
	cts->frame_control =
	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2209 2210
	cts->duration = ieee80211_ctstoself_duration(hw, vif,
						     frame_len, frame_txctl);
2211 2212 2213 2214 2215
	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
}
EXPORT_SYMBOL(ieee80211_ctstoself_get);

struct sk_buff *
2216
ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2217
			  struct ieee80211_vif *vif)
2218 2219
{
	struct ieee80211_local *local = hw_to_local(hw);
2220
	struct sk_buff *skb = NULL;
2221
	struct sta_info *sta;
2222
	struct ieee80211_tx_data tx;
2223 2224
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_if_ap *bss = NULL;
2225
	struct beacon_data *beacon;
2226
	struct ieee80211_tx_info *info;
2227

2228
	sdata = vif_to_sdata(vif);
2229
	bss = &sdata->u.ap;
2230 2231

	if (!bss)
2232 2233
		return NULL;

2234 2235 2236
	rcu_read_lock();
	beacon = rcu_dereference(bss->beacon);

2237
	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
2238
		goto out;
2239

2240
	if (bss->dtim_count != 0)
2241
		goto out; /* send buffered bc/mc only after DTIM beacon */
2242

2243 2244 2245
	while (1) {
		skb = skb_dequeue(&bss->ps_bc_buf);
		if (!skb)
2246
			goto out;
2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258
		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);
		}

2259
		if (!ieee80211_tx_prepare(local, &tx, skb))
2260 2261 2262
			break;
		dev_kfree_skb_any(skb);
	}
2263 2264 2265

	info = IEEE80211_SKB_CB(skb);

2266
	sta = tx.sta;
2267 2268
	tx.flags |= IEEE80211_TX_PS_BUFFERED;
	tx.channel = local->hw.conf.channel;
2269
	info->band = tx.channel->band;
2270

2271
	if (invoke_tx_handlers(&tx))
2272
		skb = NULL;
2273
 out:
2274
	rcu_read_unlock();
2275 2276 2277 2278

	return skb;
}
EXPORT_SYMBOL(ieee80211_get_buffered_bc);